diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/cse_main.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/cse_main.py new file mode 100644 index 0000000000000000000000000000000000000000..bcd1b2e50adae8c3d3400d6c489e63a44ae1e59b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/cse_main.py @@ -0,0 +1,945 @@ +""" Tools for doing common subexpression elimination. +""" +from collections import defaultdict + +from sympy.core import Basic, Mul, Add, Pow, sympify +from sympy.core.containers import Tuple, OrderedSet +from sympy.core.exprtools import factor_terms +from sympy.core.singleton import S +from sympy.core.sorting import ordered +from sympy.core.symbol import symbols, Symbol +from sympy.matrices import (MatrixBase, Matrix, ImmutableMatrix, + SparseMatrix, ImmutableSparseMatrix) +from sympy.matrices.expressions import (MatrixExpr, MatrixSymbol, MatMul, + MatAdd, MatPow, Inverse) +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.polys.rootoftools import RootOf +from sympy.utilities.iterables import numbered_symbols, sift, \ + topological_sort, iterable + +from . import cse_opts + +# (preprocessor, postprocessor) pairs which are commonly useful. They should +# each take a SymPy expression and return a possibly transformed expression. +# When used in the function ``cse()``, the target expressions will be transformed +# by each of the preprocessor functions in order. After the common +# subexpressions are eliminated, each resulting expression will have the +# postprocessor functions transform them in *reverse* order in order to undo the +# transformation if necessary. This allows the algorithm to operate on +# a representation of the expressions that allows for more optimization +# opportunities. +# ``None`` can be used to specify no transformation for either the preprocessor or +# postprocessor. + + +basic_optimizations = [(cse_opts.sub_pre, cse_opts.sub_post), + (factor_terms, None)] + +# sometimes we want the output in a different format; non-trivial +# transformations can be put here for users +# =============================================================== + + +def reps_toposort(r): + """Sort replacements ``r`` so (k1, v1) appears before (k2, v2) + if k2 is in v1's free symbols. This orders items in the + way that cse returns its results (hence, in order to use the + replacements in a substitution option it would make sense + to reverse the order). + + Examples + ======== + + >>> from sympy.simplify.cse_main import reps_toposort + >>> from sympy.abc import x, y + >>> from sympy import Eq + >>> for l, r in reps_toposort([(x, y + 1), (y, 2)]): + ... print(Eq(l, r)) + ... + Eq(y, 2) + Eq(x, y + 1) + + """ + r = sympify(r) + E = [] + for c1, (k1, v1) in enumerate(r): + for c2, (k2, v2) in enumerate(r): + if k1 in v2.free_symbols: + E.append((c1, c2)) + return [r[i] for i in topological_sort((range(len(r)), E))] + + +def cse_separate(r, e): + """Move expressions that are in the form (symbol, expr) out of the + expressions and sort them into the replacements using the reps_toposort. + + Examples + ======== + + >>> from sympy.simplify.cse_main import cse_separate + >>> from sympy.abc import x, y, z + >>> from sympy import cos, exp, cse, Eq, symbols + >>> x0, x1 = symbols('x:2') + >>> eq = (x + 1 + exp((x + 1)/(y + 1)) + cos(y + 1)) + >>> cse([eq, Eq(x, z + 1), z - 2], postprocess=cse_separate) in [ + ... [[(x0, y + 1), (x, z + 1), (x1, x + 1)], + ... [x1 + exp(x1/x0) + cos(x0), z - 2]], + ... [[(x1, y + 1), (x, z + 1), (x0, x + 1)], + ... [x0 + exp(x0/x1) + cos(x1), z - 2]]] + ... + True + """ + d = sift(e, lambda w: w.is_Equality and w.lhs.is_Symbol) + r = r + [w.args for w in d[True]] + e = d[False] + return [reps_toposort(r), e] + + +def cse_release_variables(r, e): + """ + Return tuples giving ``(a, b)`` where ``a`` is a symbol and ``b`` is + either an expression or None. The value of None is used when a + symbol is no longer needed for subsequent expressions. + + Use of such output can reduce the memory footprint of lambdified + expressions that contain large, repeated subexpressions. + + Examples + ======== + + >>> from sympy import cse + >>> from sympy.simplify.cse_main import cse_release_variables + >>> from sympy.abc import x, y + >>> eqs = [(x + y - 1)**2, x, x + y, (x + y)/(2*x + 1) + (x + y - 1)**2, (2*x + 1)**(x + y)] + >>> defs, rvs = cse_release_variables(*cse(eqs)) + >>> for i in defs: + ... print(i) + ... + (x0, x + y) + (x1, (x0 - 1)**2) + (x2, 2*x + 1) + (_3, x0/x2 + x1) + (_4, x2**x0) + (x2, None) + (_0, x1) + (x1, None) + (_2, x0) + (x0, None) + (_1, x) + >>> print(rvs) + (_0, _1, _2, _3, _4) + """ + if not r: + return r, e + + s, p = zip(*r) + esyms = symbols('_:%d' % len(e)) + syms = list(esyms) + s = list(s) + in_use = set(s) + p = list(p) + # sort e so those with most sub-expressions appear first + e = [(e[i], syms[i]) for i in range(len(e))] + e, syms = zip(*sorted(e, + key=lambda x: -sum(p[s.index(i)].count_ops() + for i in x[0].free_symbols & in_use))) + syms = list(syms) + p += e + rv = [] + i = len(p) - 1 + while i >= 0: + _p = p.pop() + c = in_use & _p.free_symbols + if c: # sorting for canonical results + rv.extend([(s, None) for s in sorted(c, key=str)]) + if i >= len(r): + rv.append((syms.pop(), _p)) + else: + rv.append((s[i], _p)) + in_use -= c + i -= 1 + rv.reverse() + return rv, esyms + + +# ====end of cse postprocess idioms=========================== + + +def preprocess_for_cse(expr, optimizations): + """ Preprocess an expression to optimize for common subexpression + elimination. + + Parameters + ========== + + expr : SymPy expression + The target expression to optimize. + optimizations : list of (callable, callable) pairs + The (preprocessor, postprocessor) pairs. + + Returns + ======= + + expr : SymPy expression + The transformed expression. + """ + for pre, post in optimizations: + if pre is not None: + expr = pre(expr) + return expr + + +def postprocess_for_cse(expr, optimizations): + """Postprocess an expression after common subexpression elimination to + return the expression to canonical SymPy form. + + Parameters + ========== + + expr : SymPy expression + The target expression to transform. + optimizations : list of (callable, callable) pairs, optional + The (preprocessor, postprocessor) pairs. The postprocessors will be + applied in reversed order to undo the effects of the preprocessors + correctly. + + Returns + ======= + + expr : SymPy expression + The transformed expression. + """ + for pre, post in reversed(optimizations): + if post is not None: + expr = post(expr) + return expr + + +class FuncArgTracker: + """ + A class which manages a mapping from functions to arguments and an inverse + mapping from arguments to functions. + """ + + def __init__(self, funcs): + # To minimize the number of symbolic comparisons, all function arguments + # get assigned a value number. + self.value_numbers = {} + self.value_number_to_value = [] + + # Both of these maps use integer indices for arguments / functions. + self.arg_to_funcset = [] + self.func_to_argset = [] + + for func_i, func in enumerate(funcs): + func_argset = OrderedSet() + + for func_arg in func.args: + arg_number = self.get_or_add_value_number(func_arg) + func_argset.add(arg_number) + self.arg_to_funcset[arg_number].add(func_i) + + self.func_to_argset.append(func_argset) + + def get_args_in_value_order(self, argset): + """ + Return the list of arguments in sorted order according to their value + numbers. + """ + return [self.value_number_to_value[argn] for argn in sorted(argset)] + + def get_or_add_value_number(self, value): + """ + Return the value number for the given argument. + """ + nvalues = len(self.value_numbers) + value_number = self.value_numbers.setdefault(value, nvalues) + if value_number == nvalues: + self.value_number_to_value.append(value) + self.arg_to_funcset.append(OrderedSet()) + return value_number + + def stop_arg_tracking(self, func_i): + """ + Remove the function func_i from the argument to function mapping. + """ + for arg in self.func_to_argset[func_i]: + self.arg_to_funcset[arg].remove(func_i) + + + def get_common_arg_candidates(self, argset, min_func_i=0): + """Return a dict whose keys are function numbers. The entries of the dict are + the number of arguments said function has in common with + ``argset``. Entries have at least 2 items in common. All keys have + value at least ``min_func_i``. + """ + count_map = defaultdict(lambda: 0) + if not argset: + return count_map + + funcsets = [self.arg_to_funcset[arg] for arg in argset] + # As an optimization below, we handle the largest funcset separately from + # the others. + largest_funcset = max(funcsets, key=len) + + for funcset in funcsets: + if largest_funcset is funcset: + continue + for func_i in funcset: + if func_i >= min_func_i: + count_map[func_i] += 1 + + # We pick the smaller of the two containers (count_map, largest_funcset) + # to iterate over to reduce the number of iterations needed. + (smaller_funcs_container, + larger_funcs_container) = sorted( + [largest_funcset, count_map], + key=len) + + for func_i in smaller_funcs_container: + # Not already in count_map? It can't possibly be in the output, so + # skip it. + if count_map[func_i] < 1: + continue + + if func_i in larger_funcs_container: + count_map[func_i] += 1 + + return {k: v for k, v in count_map.items() if v >= 2} + + def get_subset_candidates(self, argset, restrict_to_funcset=None): + """ + Return a set of functions each of which whose argument list contains + ``argset``, optionally filtered only to contain functions in + ``restrict_to_funcset``. + """ + iarg = iter(argset) + + indices = OrderedSet( + fi for fi in self.arg_to_funcset[next(iarg)]) + + if restrict_to_funcset is not None: + indices &= restrict_to_funcset + + for arg in iarg: + indices &= self.arg_to_funcset[arg] + + return indices + + def update_func_argset(self, func_i, new_argset): + """ + Update a function with a new set of arguments. + """ + new_args = OrderedSet(new_argset) + old_args = self.func_to_argset[func_i] + + for deleted_arg in old_args - new_args: + self.arg_to_funcset[deleted_arg].remove(func_i) + for added_arg in new_args - old_args: + self.arg_to_funcset[added_arg].add(func_i) + + self.func_to_argset[func_i].clear() + self.func_to_argset[func_i].update(new_args) + + +class Unevaluated: + + def __init__(self, func, args): + self.func = func + self.args = args + + def __str__(self): + return "Uneval<{}>({})".format( + self.func, ", ".join(str(a) for a in self.args)) + + def as_unevaluated_basic(self): + return self.func(*self.args, evaluate=False) + + @property + def free_symbols(self): + return set().union(*[a.free_symbols for a in self.args]) + + __repr__ = __str__ + + +def match_common_args(func_class, funcs, opt_subs): + """ + Recognize and extract common subexpressions of function arguments within a + set of function calls. For instance, for the following function calls:: + + x + z + y + sin(x + y) + + this will extract a common subexpression of `x + y`:: + + w = x + y + w + z + sin(w) + + The function we work with is assumed to be associative and commutative. + + Parameters + ========== + + func_class: class + The function class (e.g. Add, Mul) + funcs: list of functions + A list of function calls. + opt_subs: dict + A dictionary of substitutions which this function may update. + """ + + # Sort to ensure that whole-function subexpressions come before the items + # that use them. + funcs = sorted(funcs, key=lambda f: len(f.args)) + arg_tracker = FuncArgTracker(funcs) + + changed = OrderedSet() + + for i in range(len(funcs)): + common_arg_candidates_counts = arg_tracker.get_common_arg_candidates( + arg_tracker.func_to_argset[i], min_func_i=i + 1) + + # Sort the candidates in order of match size. + # This makes us try combining smaller matches first. + common_arg_candidates = OrderedSet(sorted( + common_arg_candidates_counts.keys(), + key=lambda k: (common_arg_candidates_counts[k], k))) + + while common_arg_candidates: + j = common_arg_candidates.pop(last=False) + + com_args = arg_tracker.func_to_argset[i].intersection( + arg_tracker.func_to_argset[j]) + + if len(com_args) <= 1: + # This may happen if a set of common arguments was already + # combined in a previous iteration. + continue + + # For all sets, replace the common symbols by the function + # over them, to allow recursive matches. + + diff_i = arg_tracker.func_to_argset[i].difference(com_args) + if diff_i: + # com_func needs to be unevaluated to allow for recursive matches. + com_func = Unevaluated( + func_class, arg_tracker.get_args_in_value_order(com_args)) + com_func_number = arg_tracker.get_or_add_value_number(com_func) + arg_tracker.update_func_argset(i, diff_i | OrderedSet([com_func_number])) + changed.add(i) + else: + # Treat the whole expression as a CSE. + # + # The reason this needs to be done is somewhat subtle. Within + # tree_cse(), to_eliminate only contains expressions that are + # seen more than once. The problem is unevaluated expressions + # do not compare equal to the evaluated equivalent. So + # tree_cse() won't mark funcs[i] as a CSE if we use an + # unevaluated version. + com_func_number = arg_tracker.get_or_add_value_number(funcs[i]) + + diff_j = arg_tracker.func_to_argset[j].difference(com_args) + arg_tracker.update_func_argset(j, diff_j | OrderedSet([com_func_number])) + changed.add(j) + + for k in arg_tracker.get_subset_candidates( + com_args, common_arg_candidates): + diff_k = arg_tracker.func_to_argset[k].difference(com_args) + arg_tracker.update_func_argset(k, diff_k | OrderedSet([com_func_number])) + changed.add(k) + + if i in changed: + opt_subs[funcs[i]] = Unevaluated(func_class, + arg_tracker.get_args_in_value_order(arg_tracker.func_to_argset[i])) + + arg_tracker.stop_arg_tracking(i) + + +def opt_cse(exprs, order='canonical'): + """Find optimization opportunities in Adds, Muls, Pows and negative + coefficient Muls. + + Parameters + ========== + + exprs : list of SymPy expressions + The expressions to optimize. + order : string, 'none' or 'canonical' + The order by which Mul and Add arguments are processed. For large + expressions where speed is a concern, use the setting order='none'. + + Returns + ======= + + opt_subs : dictionary of expression substitutions + The expression substitutions which can be useful to optimize CSE. + + Examples + ======== + + >>> from sympy.simplify.cse_main import opt_cse + >>> from sympy.abc import x + >>> opt_subs = opt_cse([x**-2]) + >>> k, v = list(opt_subs.keys())[0], list(opt_subs.values())[0] + >>> print((k, v.as_unevaluated_basic())) + (x**(-2), 1/(x**2)) + """ + opt_subs = {} + + adds = OrderedSet() + muls = OrderedSet() + + seen_subexp = set() + collapsible_subexp = set() + + def _find_opts(expr): + + if not isinstance(expr, (Basic, Unevaluated)): + return + + if expr.is_Atom or expr.is_Order: + return + + if iterable(expr): + list(map(_find_opts, expr)) + return + + if expr in seen_subexp: + return expr + seen_subexp.add(expr) + + list(map(_find_opts, expr.args)) + + if not isinstance(expr, MatrixExpr) and expr.could_extract_minus_sign(): + # XXX -expr does not always work rigorously for some expressions + # containing UnevaluatedExpr. + # https://github.com/sympy/sympy/issues/24818 + if isinstance(expr, Add): + neg_expr = Add(*(-i for i in expr.args)) + else: + neg_expr = -expr + + if not neg_expr.is_Atom: + opt_subs[expr] = Unevaluated(Mul, (S.NegativeOne, neg_expr)) + seen_subexp.add(neg_expr) + expr = neg_expr + + if isinstance(expr, (Mul, MatMul)): + if len(expr.args) == 1: + collapsible_subexp.add(expr) + else: + muls.add(expr) + + elif isinstance(expr, (Add, MatAdd)): + if len(expr.args) == 1: + collapsible_subexp.add(expr) + else: + adds.add(expr) + + elif isinstance(expr, Inverse): + # Do not want to treat `Inverse` as a `MatPow` + pass + + elif isinstance(expr, (Pow, MatPow)): + base, exp = expr.base, expr.exp + if exp.could_extract_minus_sign(): + opt_subs[expr] = Unevaluated(Pow, (Pow(base, -exp), -1)) + + for e in exprs: + if isinstance(e, (Basic, Unevaluated)): + _find_opts(e) + + # Handle collapsing of multinary operations with single arguments + edges = [(s, s.args[0]) for s in collapsible_subexp + if s.args[0] in collapsible_subexp] + for e in reversed(topological_sort((collapsible_subexp, edges))): + opt_subs[e] = opt_subs.get(e.args[0], e.args[0]) + + # split muls into commutative + commutative_muls = OrderedSet() + for m in muls: + c, nc = m.args_cnc(cset=False) + if c: + c_mul = m.func(*c) + if nc: + if c_mul == 1: + new_obj = m.func(*nc) + else: + if isinstance(m, MatMul): + new_obj = m.func(c_mul, *nc, evaluate=False) + else: + new_obj = m.func(c_mul, m.func(*nc), evaluate=False) + opt_subs[m] = new_obj + if len(c) > 1: + commutative_muls.add(c_mul) + + match_common_args(Add, adds, opt_subs) + match_common_args(Mul, commutative_muls, opt_subs) + + return opt_subs + + +def tree_cse(exprs, symbols, opt_subs=None, order='canonical', ignore=()): + """Perform raw CSE on expression tree, taking opt_subs into account. + + Parameters + ========== + + exprs : list of SymPy expressions + The expressions to reduce. + symbols : infinite iterator yielding unique Symbols + The symbols used to label the common subexpressions which are pulled + out. + opt_subs : dictionary of expression substitutions + The expressions to be substituted before any CSE action is performed. + order : string, 'none' or 'canonical' + The order by which Mul and Add arguments are processed. For large + expressions where speed is a concern, use the setting order='none'. + ignore : iterable of Symbols + Substitutions containing any Symbol from ``ignore`` will be ignored. + """ + if opt_subs is None: + opt_subs = {} + + ## Find repeated sub-expressions + + to_eliminate = set() + + seen_subexp = set() + excluded_symbols = set() + + def _find_repeated(expr): + if not isinstance(expr, (Basic, Unevaluated)): + return + + if isinstance(expr, RootOf): + return + + if isinstance(expr, Basic) and ( + expr.is_Atom or + expr.is_Order or + isinstance(expr, (MatrixSymbol, MatrixElement))): + if expr.is_Symbol: + excluded_symbols.add(expr.name) + return + + if iterable(expr): + args = expr + + else: + if expr in seen_subexp: + for ign in ignore: + if ign in expr.free_symbols: + break + else: + to_eliminate.add(expr) + return + + seen_subexp.add(expr) + + if expr in opt_subs: + expr = opt_subs[expr] + + args = expr.args + + list(map(_find_repeated, args)) + + for e in exprs: + if isinstance(e, Basic): + _find_repeated(e) + + ## Rebuild tree + + # Remove symbols from the generator that conflict with names in the expressions. + symbols = (_ for _ in symbols if _.name not in excluded_symbols) + + replacements = [] + + subs = {} + + def _rebuild(expr): + if not isinstance(expr, (Basic, Unevaluated)): + return expr + + if not expr.args: + return expr + + if iterable(expr): + new_args = [_rebuild(arg) for arg in expr.args] + return expr.func(*new_args) + + if expr in subs: + return subs[expr] + + orig_expr = expr + if expr in opt_subs: + expr = opt_subs[expr] + + # If enabled, parse Muls and Adds arguments by order to ensure + # replacement order independent from hashes + if order != 'none': + if isinstance(expr, (Mul, MatMul)): + c, nc = expr.args_cnc() + if c == [1]: + args = nc + else: + args = list(ordered(c)) + nc + elif isinstance(expr, (Add, MatAdd)): + args = list(ordered(expr.args)) + else: + args = expr.args + else: + args = expr.args + + new_args = list(map(_rebuild, args)) + if isinstance(expr, Unevaluated) or new_args != args: + new_expr = expr.func(*new_args) + else: + new_expr = expr + + if orig_expr in to_eliminate: + try: + sym = next(symbols) + except StopIteration: + raise ValueError("Symbols iterator ran out of symbols.") + + if isinstance(orig_expr, MatrixExpr): + sym = MatrixSymbol(sym.name, orig_expr.rows, + orig_expr.cols) + + subs[orig_expr] = sym + replacements.append((sym, new_expr)) + return sym + + else: + return new_expr + + reduced_exprs = [] + for e in exprs: + if isinstance(e, Basic): + reduced_e = _rebuild(e) + else: + reduced_e = e + reduced_exprs.append(reduced_e) + return replacements, reduced_exprs + + +def cse(exprs, symbols=None, optimizations=None, postprocess=None, + order='canonical', ignore=(), list=True): + """ Perform common subexpression elimination on an expression. + + Parameters + ========== + + exprs : list of SymPy expressions, or a single SymPy expression + The expressions to reduce. + symbols : infinite iterator yielding unique Symbols + The symbols used to label the common subexpressions which are pulled + out. The ``numbered_symbols`` generator is useful. The default is a + stream of symbols of the form "x0", "x1", etc. This must be an + infinite iterator. + optimizations : list of (callable, callable) pairs + The (preprocessor, postprocessor) pairs of external optimization + functions. Optionally 'basic' can be passed for a set of predefined + basic optimizations. Such 'basic' optimizations were used by default + in old implementation, however they can be really slow on larger + expressions. Now, no pre or post optimizations are made by default. + postprocess : a function which accepts the two return values of cse and + returns the desired form of output from cse, e.g. if you want the + replacements reversed the function might be the following lambda: + lambda r, e: return reversed(r), e + order : string, 'none' or 'canonical' + The order by which Mul and Add arguments are processed. If set to + 'canonical', arguments will be canonically ordered. If set to 'none', + ordering will be faster but dependent on expressions hashes, thus + machine dependent and variable. For large expressions where speed is a + concern, use the setting order='none'. + ignore : iterable of Symbols + Substitutions containing any Symbol from ``ignore`` will be ignored. + list : bool, (default True) + Returns expression in list or else with same type as input (when False). + + Returns + ======= + + replacements : list of (Symbol, expression) pairs + All of the common subexpressions that were replaced. Subexpressions + earlier in this list might show up in subexpressions later in this + list. + reduced_exprs : list of SymPy expressions + The reduced expressions with all of the replacements above. + + Examples + ======== + + >>> from sympy import cse, SparseMatrix + >>> from sympy.abc import x, y, z, w + >>> cse(((w + x + y + z)*(w + y + z))/(w + x)**3) + ([(x0, y + z), (x1, w + x)], [(w + x0)*(x0 + x1)/x1**3]) + + + List of expressions with recursive substitutions: + + >>> m = SparseMatrix([x + y, x + y + z]) + >>> cse([(x+y)**2, x + y + z, y + z, x + z + y, m]) + ([(x0, x + y), (x1, x0 + z)], [x0**2, x1, y + z, x1, Matrix([ + [x0], + [x1]])]) + + Note: the type and mutability of input matrices is retained. + + >>> isinstance(_[1][-1], SparseMatrix) + True + + The user may disallow substitutions containing certain symbols: + + >>> cse([y**2*(x + 1), 3*y**2*(x + 1)], ignore=(y,)) + ([(x0, x + 1)], [x0*y**2, 3*x0*y**2]) + + The default return value for the reduced expression(s) is a list, even if there is only + one expression. The `list` flag preserves the type of the input in the output: + + >>> cse(x) + ([], [x]) + >>> cse(x, list=False) + ([], x) + """ + if not list: + return _cse_homogeneous(exprs, + symbols=symbols, optimizations=optimizations, + postprocess=postprocess, order=order, ignore=ignore) + + if isinstance(exprs, (int, float)): + exprs = sympify(exprs) + + # Handle the case if just one expression was passed. + if isinstance(exprs, (Basic, MatrixBase)): + exprs = [exprs] + + copy = exprs + temp = [] + for e in exprs: + if isinstance(e, (Matrix, ImmutableMatrix)): + temp.append(Tuple(*e.flat())) + elif isinstance(e, (SparseMatrix, ImmutableSparseMatrix)): + temp.append(Tuple(*e.todok().items())) + else: + temp.append(e) + exprs = temp + del temp + + if optimizations is None: + optimizations = [] + elif optimizations == 'basic': + optimizations = basic_optimizations + + # Preprocess the expressions to give us better optimization opportunities. + reduced_exprs = [preprocess_for_cse(e, optimizations) for e in exprs] + + if symbols is None: + symbols = numbered_symbols(cls=Symbol) + else: + # In case we get passed an iterable with an __iter__ method instead of + # an actual iterator. + symbols = iter(symbols) + + # Find other optimization opportunities. + opt_subs = opt_cse(reduced_exprs, order) + + # Main CSE algorithm. + replacements, reduced_exprs = tree_cse(reduced_exprs, symbols, opt_subs, + order, ignore) + + # Postprocess the expressions to return the expressions to canonical form. + exprs = copy + replacements = [(sym, postprocess_for_cse(subtree, optimizations)) + for sym, subtree in replacements] + reduced_exprs = [postprocess_for_cse(e, optimizations) + for e in reduced_exprs] + + # Get the matrices back + for i, e in enumerate(exprs): + if isinstance(e, (Matrix, ImmutableMatrix)): + reduced_exprs[i] = Matrix(e.rows, e.cols, reduced_exprs[i]) + if isinstance(e, ImmutableMatrix): + reduced_exprs[i] = reduced_exprs[i].as_immutable() + elif isinstance(e, (SparseMatrix, ImmutableSparseMatrix)): + m = SparseMatrix(e.rows, e.cols, {}) + for k, v in reduced_exprs[i]: + m[k] = v + if isinstance(e, ImmutableSparseMatrix): + m = m.as_immutable() + reduced_exprs[i] = m + + if postprocess is None: + return replacements, reduced_exprs + + return postprocess(replacements, reduced_exprs) + + +def _cse_homogeneous(exprs, **kwargs): + """ + Same as ``cse`` but the ``reduced_exprs`` are returned + with the same type as ``exprs`` or a sympified version of the same. + + Parameters + ========== + + exprs : an Expr, iterable of Expr or dictionary with Expr values + the expressions in which repeated subexpressions will be identified + kwargs : additional arguments for the ``cse`` function + + Returns + ======= + + replacements : list of (Symbol, expression) pairs + All of the common subexpressions that were replaced. Subexpressions + earlier in this list might show up in subexpressions later in this + list. + reduced_exprs : list of SymPy expressions + The reduced expressions with all of the replacements above. + + Examples + ======== + + >>> from sympy.simplify.cse_main import cse + >>> from sympy import cos, Tuple, Matrix + >>> from sympy.abc import x + >>> output = lambda x: type(cse(x, list=False)[1]) + >>> output(1) + + >>> output('cos(x)') + + >>> output(cos(x)) + cos + >>> output(Tuple(1, x)) + + >>> output(Matrix([[1,0], [0,1]])) + + >>> output([1, x]) + + >>> output((1, x)) + + >>> output({1, x}) + + """ + if isinstance(exprs, str): + replacements, reduced_exprs = _cse_homogeneous( + sympify(exprs), **kwargs) + return replacements, repr(reduced_exprs) + if isinstance(exprs, (list, tuple, set)): + replacements, reduced_exprs = cse(exprs, **kwargs) + return replacements, type(exprs)(reduced_exprs) + if isinstance(exprs, dict): + keys = list(exprs.keys()) # In order to guarantee the order of the elements. + replacements, values = cse([exprs[k] for k in keys], **kwargs) + reduced_exprs = dict(zip(keys, values)) + return replacements, reduced_exprs + + try: + replacements, (reduced_exprs,) = cse(exprs, **kwargs) + except TypeError: # For example 'mpf' objects + return [], exprs + else: + return replacements, reduced_exprs diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/cse_opts.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/cse_opts.py new file mode 100644 index 0000000000000000000000000000000000000000..36a59857411de740ae47423442af88b118a3395d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/cse_opts.py @@ -0,0 +1,52 @@ +""" Optimizations of the expression tree representation for better CSE +opportunities. +""" +from sympy.core import Add, Basic, Mul +from sympy.core.singleton import S +from sympy.core.sorting import default_sort_key +from sympy.core.traversal import preorder_traversal + + +def sub_pre(e): + """ Replace y - x with -(x - y) if -1 can be extracted from y - x. + """ + # replacing Add, A, from which -1 can be extracted with -1*-A + adds = [a for a in e.atoms(Add) if a.could_extract_minus_sign()] + reps = {} + ignore = set() + for a in adds: + na = -a + if na.is_Mul: # e.g. MatExpr + ignore.add(a) + continue + reps[a] = Mul._from_args([S.NegativeOne, na]) + + e = e.xreplace(reps) + + # repeat again for persisting Adds but mark these with a leading 1, -1 + # e.g. y - x -> 1*-1*(x - y) + if isinstance(e, Basic): + negs = {} + for a in sorted(e.atoms(Add), key=default_sort_key): + if a in ignore: + continue + if a in reps: + negs[a] = reps[a] + elif a.could_extract_minus_sign(): + negs[a] = Mul._from_args([S.One, S.NegativeOne, -a]) + e = e.xreplace(negs) + return e + + +def sub_post(e): + """ Replace 1*-1*x with -x. + """ + replacements = [] + for node in preorder_traversal(e): + if isinstance(node, Mul) and \ + node.args[0] is S.One and node.args[1] is S.NegativeOne: + replacements.append((node, -Mul._from_args(node.args[2:]))) + for node, replacement in replacements: + e = e.xreplace({node: replacement}) + + return e diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/epathtools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/epathtools.py new file mode 100644 index 0000000000000000000000000000000000000000..7be983ada63fd39d7d467acf9afd62b3a41a2d85 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/epathtools.py @@ -0,0 +1,352 @@ +"""Tools for manipulation of expressions using paths. """ + +from sympy.core import Basic + + +class EPath: + r""" + Manipulate expressions using paths. + + EPath grammar in EBNF notation:: + + literal ::= /[A-Za-z_][A-Za-z_0-9]*/ + number ::= /-?\d+/ + type ::= literal + attribute ::= literal "?" + all ::= "*" + slice ::= "[" number? (":" number? (":" number?)?)? "]" + range ::= all | slice + query ::= (type | attribute) ("|" (type | attribute))* + selector ::= range | query range? + path ::= "/" selector ("/" selector)* + + See the docstring of the epath() function. + + """ + + __slots__ = ("_path", "_epath") + + def __new__(cls, path): + """Construct new EPath. """ + if isinstance(path, EPath): + return path + + if not path: + raise ValueError("empty EPath") + + _path = path + + if path[0] == '/': + path = path[1:] + else: + raise NotImplementedError("non-root EPath") + + epath = [] + + for selector in path.split('/'): + selector = selector.strip() + + if not selector: + raise ValueError("empty selector") + + index = 0 + + for c in selector: + if c.isalnum() or c in ('_', '|', '?'): + index += 1 + else: + break + + attrs = [] + types = [] + + if index: + elements = selector[:index] + selector = selector[index:] + + for element in elements.split('|'): + element = element.strip() + + if not element: + raise ValueError("empty element") + + if element.endswith('?'): + attrs.append(element[:-1]) + else: + types.append(element) + + span = None + + if selector == '*': + pass + else: + if selector.startswith('['): + try: + i = selector.index(']') + except ValueError: + raise ValueError("expected ']', got EOL") + + _span, span = selector[1:i], [] + + if ':' not in _span: + span = int(_span) + else: + for elt in _span.split(':', 3): + if not elt: + span.append(None) + else: + span.append(int(elt)) + + span = slice(*span) + + selector = selector[i + 1:] + + if selector: + raise ValueError("trailing characters in selector") + + epath.append((attrs, types, span)) + + obj = object.__new__(cls) + + obj._path = _path + obj._epath = epath + + return obj + + def __repr__(self): + return "%s(%r)" % (self.__class__.__name__, self._path) + + def _get_ordered_args(self, expr): + """Sort ``expr.args`` using printing order. """ + if expr.is_Add: + return expr.as_ordered_terms() + elif expr.is_Mul: + return expr.as_ordered_factors() + else: + return expr.args + + def _hasattrs(self, expr, attrs) -> bool: + """Check if ``expr`` has any of ``attrs``. """ + return all(hasattr(expr, attr) for attr in attrs) + + def _hastypes(self, expr, types): + """Check if ``expr`` is any of ``types``. """ + _types = [ cls.__name__ for cls in expr.__class__.mro() ] + return bool(set(_types).intersection(types)) + + def _has(self, expr, attrs, types): + """Apply ``_hasattrs`` and ``_hastypes`` to ``expr``. """ + if not (attrs or types): + return True + + if attrs and self._hasattrs(expr, attrs): + return True + + if types and self._hastypes(expr, types): + return True + + return False + + def apply(self, expr, func, args=None, kwargs=None): + """ + Modify parts of an expression selected by a path. + + Examples + ======== + + >>> from sympy.simplify.epathtools import EPath + >>> from sympy import sin, cos, E + >>> from sympy.abc import x, y, z, t + + >>> path = EPath("/*/[0]/Symbol") + >>> expr = [((x, 1), 2), ((3, y), z)] + + >>> path.apply(expr, lambda expr: expr**2) + [((x**2, 1), 2), ((3, y**2), z)] + + >>> path = EPath("/*/*/Symbol") + >>> expr = t + sin(x + 1) + cos(x + y + E) + + >>> path.apply(expr, lambda expr: 2*expr) + t + sin(2*x + 1) + cos(2*x + 2*y + E) + + """ + def _apply(path, expr, func): + if not path: + return func(expr) + else: + selector, path = path[0], path[1:] + attrs, types, span = selector + + if isinstance(expr, Basic): + if not expr.is_Atom: + args, basic = self._get_ordered_args(expr), True + else: + return expr + elif hasattr(expr, '__iter__'): + args, basic = expr, False + else: + return expr + + args = list(args) + + if span is not None: + if isinstance(span, slice): + indices = range(*span.indices(len(args))) + else: + indices = [span] + else: + indices = range(len(args)) + + for i in indices: + try: + arg = args[i] + except IndexError: + continue + + if self._has(arg, attrs, types): + args[i] = _apply(path, arg, func) + + if basic: + return expr.func(*args) + else: + return expr.__class__(args) + + _args, _kwargs = args or (), kwargs or {} + _func = lambda expr: func(expr, *_args, **_kwargs) + + return _apply(self._epath, expr, _func) + + def select(self, expr): + """ + Retrieve parts of an expression selected by a path. + + Examples + ======== + + >>> from sympy.simplify.epathtools import EPath + >>> from sympy import sin, cos, E + >>> from sympy.abc import x, y, z, t + + >>> path = EPath("/*/[0]/Symbol") + >>> expr = [((x, 1), 2), ((3, y), z)] + + >>> path.select(expr) + [x, y] + + >>> path = EPath("/*/*/Symbol") + >>> expr = t + sin(x + 1) + cos(x + y + E) + + >>> path.select(expr) + [x, x, y] + + """ + result = [] + + def _select(path, expr): + if not path: + result.append(expr) + else: + selector, path = path[0], path[1:] + attrs, types, span = selector + + if isinstance(expr, Basic): + args = self._get_ordered_args(expr) + elif hasattr(expr, '__iter__'): + args = expr + else: + return + + if span is not None: + if isinstance(span, slice): + args = args[span] + else: + try: + args = [args[span]] + except IndexError: + return + + for arg in args: + if self._has(arg, attrs, types): + _select(path, arg) + + _select(self._epath, expr) + return result + + +def epath(path, expr=None, func=None, args=None, kwargs=None): + r""" + Manipulate parts of an expression selected by a path. + + Explanation + =========== + + This function allows to manipulate large nested expressions in single + line of code, utilizing techniques to those applied in XML processing + standards (e.g. XPath). + + If ``func`` is ``None``, :func:`epath` retrieves elements selected by + the ``path``. Otherwise it applies ``func`` to each matching element. + + Note that it is more efficient to create an EPath object and use the select + and apply methods of that object, since this will compile the path string + only once. This function should only be used as a convenient shortcut for + interactive use. + + This is the supported syntax: + + * select all: ``/*`` + Equivalent of ``for arg in args:``. + * select slice: ``/[0]`` or ``/[1:5]`` or ``/[1:5:2]`` + Supports standard Python's slice syntax. + * select by type: ``/list`` or ``/list|tuple`` + Emulates ``isinstance()``. + * select by attribute: ``/__iter__?`` + Emulates ``hasattr()``. + + Parameters + ========== + + path : str | EPath + A path as a string or a compiled EPath. + expr : Basic | iterable + An expression or a container of expressions. + func : callable (optional) + A callable that will be applied to matching parts. + args : tuple (optional) + Additional positional arguments to ``func``. + kwargs : dict (optional) + Additional keyword arguments to ``func``. + + Examples + ======== + + >>> from sympy.simplify.epathtools import epath + >>> from sympy import sin, cos, E + >>> from sympy.abc import x, y, z, t + + >>> path = "/*/[0]/Symbol" + >>> expr = [((x, 1), 2), ((3, y), z)] + + >>> epath(path, expr) + [x, y] + >>> epath(path, expr, lambda expr: expr**2) + [((x**2, 1), 2), ((3, y**2), z)] + + >>> path = "/*/*/Symbol" + >>> expr = t + sin(x + 1) + cos(x + y + E) + + >>> epath(path, expr) + [x, x, y] + >>> epath(path, expr, lambda expr: 2*expr) + t + sin(2*x + 1) + cos(2*x + 2*y + E) + + """ + _epath = EPath(path) + + if expr is None: + return _epath + if func is None: + return _epath.select(expr) + else: + return _epath.apply(expr, func, args, kwargs) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/fu.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/fu.py new file mode 100644 index 0000000000000000000000000000000000000000..a26706edca98385df0009a8ee41476a17d36420c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/fu.py @@ -0,0 +1,2112 @@ +from collections import defaultdict + +from sympy.core.add import Add +from sympy.core.cache import cacheit +from sympy.core.expr import Expr +from sympy.core.exprtools import Factors, gcd_terms, factor_terms +from sympy.core.function import expand_mul +from sympy.core.mul import Mul +from sympy.core.numbers import pi, I +from sympy.core.power import Pow +from sympy.core.singleton import S +from sympy.core.sorting import ordered +from sympy.core.symbol import Dummy +from sympy.core.sympify import sympify +from sympy.core.traversal import bottom_up +from sympy.functions.combinatorial.factorials import binomial +from sympy.functions.elementary.hyperbolic import ( + cosh, sinh, tanh, coth, sech, csch, HyperbolicFunction) +from sympy.functions.elementary.trigonometric import ( + cos, sin, tan, cot, sec, csc, sqrt, TrigonometricFunction) +from sympy.ntheory.factor_ import perfect_power +from sympy.polys.polytools import factor +from sympy.strategies.tree import greedy +from sympy.strategies.core import identity, debug + +from sympy import SYMPY_DEBUG + + +# ================== Fu-like tools =========================== + + +def TR0(rv): + """Simplification of rational polynomials, trying to simplify + the expression, e.g. combine things like 3*x + 2*x, etc.... + """ + # although it would be nice to use cancel, it doesn't work + # with noncommutatives + return rv.normal().factor().expand() + + +def TR1(rv): + """Replace sec, csc with 1/cos, 1/sin + + Examples + ======== + + >>> from sympy.simplify.fu import TR1, sec, csc + >>> from sympy.abc import x + >>> TR1(2*csc(x) + sec(x)) + 1/cos(x) + 2/sin(x) + """ + + def f(rv): + if isinstance(rv, sec): + a = rv.args[0] + return S.One/cos(a) + elif isinstance(rv, csc): + a = rv.args[0] + return S.One/sin(a) + return rv + + return bottom_up(rv, f) + + +def TR2(rv): + """Replace tan and cot with sin/cos and cos/sin + + Examples + ======== + + >>> from sympy.simplify.fu import TR2 + >>> from sympy.abc import x + >>> from sympy import tan, cot, sin, cos + >>> TR2(tan(x)) + sin(x)/cos(x) + >>> TR2(cot(x)) + cos(x)/sin(x) + >>> TR2(tan(tan(x) - sin(x)/cos(x))) + 0 + + """ + + def f(rv): + if isinstance(rv, tan): + a = rv.args[0] + return sin(a)/cos(a) + elif isinstance(rv, cot): + a = rv.args[0] + return cos(a)/sin(a) + return rv + + return bottom_up(rv, f) + + +def TR2i(rv, half=False): + """Converts ratios involving sin and cos as follows:: + sin(x)/cos(x) -> tan(x) + sin(x)/(cos(x) + 1) -> tan(x/2) if half=True + + Examples + ======== + + >>> from sympy.simplify.fu import TR2i + >>> from sympy.abc import x, a + >>> from sympy import sin, cos + >>> TR2i(sin(x)/cos(x)) + tan(x) + + Powers of the numerator and denominator are also recognized + + >>> TR2i(sin(x)**2/(cos(x) + 1)**2, half=True) + tan(x/2)**2 + + The transformation does not take place unless assumptions allow + (i.e. the base must be positive or the exponent must be an integer + for both numerator and denominator) + + >>> TR2i(sin(x)**a/(cos(x) + 1)**a) + sin(x)**a/(cos(x) + 1)**a + + """ + + def f(rv): + if not rv.is_Mul: + return rv + + n, d = rv.as_numer_denom() + if n.is_Atom or d.is_Atom: + return rv + + def ok(k, e): + # initial filtering of factors + return ( + (e.is_integer or k.is_positive) and ( + k.func in (sin, cos) or (half and + k.is_Add and + len(k.args) >= 2 and + any(any(isinstance(ai, cos) or ai.is_Pow and ai.base is cos + for ai in Mul.make_args(a)) for a in k.args)))) + + n = n.as_powers_dict() + ndone = [(k, n.pop(k)) for k in list(n.keys()) if not ok(k, n[k])] + if not n: + return rv + + d = d.as_powers_dict() + ddone = [(k, d.pop(k)) for k in list(d.keys()) if not ok(k, d[k])] + if not d: + return rv + + # factoring if necessary + + def factorize(d, ddone): + newk = [] + for k in d: + if k.is_Add and len(k.args) > 1: + knew = factor(k) if half else factor_terms(k) + if knew != k: + newk.append((k, knew)) + if newk: + for i, (k, knew) in enumerate(newk): + del d[k] + newk[i] = knew + newk = Mul(*newk).as_powers_dict() + for k in newk: + v = d[k] + newk[k] + if ok(k, v): + d[k] = v + else: + ddone.append((k, v)) + del newk + factorize(n, ndone) + factorize(d, ddone) + + # joining + t = [] + for k in n: + if isinstance(k, sin): + a = cos(k.args[0], evaluate=False) + if a in d and d[a] == n[k]: + t.append(tan(k.args[0])**n[k]) + n[k] = d[a] = None + elif half: + a1 = 1 + a + if a1 in d and d[a1] == n[k]: + t.append((tan(k.args[0]/2))**n[k]) + n[k] = d[a1] = None + elif isinstance(k, cos): + a = sin(k.args[0], evaluate=False) + if a in d and d[a] == n[k]: + t.append(tan(k.args[0])**-n[k]) + n[k] = d[a] = None + elif half and k.is_Add and k.args[0] is S.One and \ + isinstance(k.args[1], cos): + a = sin(k.args[1].args[0], evaluate=False) + if a in d and d[a] == n[k] and (d[a].is_integer or \ + a.is_positive): + t.append(tan(a.args[0]/2)**-n[k]) + n[k] = d[a] = None + + if t: + rv = Mul(*(t + [b**e for b, e in n.items() if e]))/\ + Mul(*[b**e for b, e in d.items() if e]) + rv *= Mul(*[b**e for b, e in ndone])/Mul(*[b**e for b, e in ddone]) + + return rv + + return bottom_up(rv, f) + + +def TR3(rv): + """Induced formula: example sin(-a) = -sin(a) + + Examples + ======== + + >>> from sympy.simplify.fu import TR3 + >>> from sympy.abc import x, y + >>> from sympy import pi + >>> from sympy import cos + >>> TR3(cos(y - x*(y - x))) + cos(x*(x - y) + y) + >>> cos(pi/2 + x) + -sin(x) + >>> cos(30*pi/2 + x) + -cos(x) + + """ + from sympy.simplify.simplify import signsimp + + # Negative argument (already automatic for funcs like sin(-x) -> -sin(x) + # but more complicated expressions can use it, too). Also, trig angles + # between pi/4 and pi/2 are not reduced to an angle between 0 and pi/4. + # The following are automatically handled: + # Argument of type: pi/2 +/- angle + # Argument of type: pi +/- angle + # Argument of type : 2k*pi +/- angle + + def f(rv): + if not isinstance(rv, TrigonometricFunction): + return rv + rv = rv.func(signsimp(rv.args[0])) + if not isinstance(rv, TrigonometricFunction): + return rv + if (rv.args[0] - S.Pi/4).is_positive is (S.Pi/2 - rv.args[0]).is_positive is True: + fmap = {cos: sin, sin: cos, tan: cot, cot: tan, sec: csc, csc: sec} + rv = fmap[type(rv)](S.Pi/2 - rv.args[0]) + return rv + + # touch numbers iside of trig functions to let them automatically update + rv = rv.replace( + lambda x: isinstance(x, TrigonometricFunction), + lambda x: x.replace( + lambda n: n.is_number and n.is_Mul, + lambda n: n.func(*n.args))) + + return bottom_up(rv, f) + + +def TR4(rv): + """Identify values of special angles. + + a= 0 pi/6 pi/4 pi/3 pi/2 + ---------------------------------------------------- + sin(a) 0 1/2 sqrt(2)/2 sqrt(3)/2 1 + cos(a) 1 sqrt(3)/2 sqrt(2)/2 1/2 0 + tan(a) 0 sqt(3)/3 1 sqrt(3) -- + + Examples + ======== + + >>> from sympy import pi + >>> from sympy import cos, sin, tan, cot + >>> for s in (0, pi/6, pi/4, pi/3, pi/2): + ... print('%s %s %s %s' % (cos(s), sin(s), tan(s), cot(s))) + ... + 1 0 0 zoo + sqrt(3)/2 1/2 sqrt(3)/3 sqrt(3) + sqrt(2)/2 sqrt(2)/2 1 1 + 1/2 sqrt(3)/2 sqrt(3) sqrt(3)/3 + 0 1 zoo 0 + """ + # special values at 0, pi/6, pi/4, pi/3, pi/2 already handled + return rv.replace( + lambda x: + isinstance(x, TrigonometricFunction) and + (r:=x.args[0]/pi).is_Rational and r.q in (1, 2, 3, 4, 6), + lambda x: + x.func(x.args[0].func(*x.args[0].args))) + + +def _TR56(rv, f, g, h, max, pow): + """Helper for TR5 and TR6 to replace f**2 with h(g**2) + + Options + ======= + + max : controls size of exponent that can appear on f + e.g. if max=4 then f**4 will be changed to h(g**2)**2. + pow : controls whether the exponent must be a perfect power of 2 + e.g. if pow=True (and max >= 6) then f**6 will not be changed + but f**8 will be changed to h(g**2)**4 + + >>> from sympy.simplify.fu import _TR56 as T + >>> from sympy.abc import x + >>> from sympy import sin, cos + >>> h = lambda x: 1 - x + >>> T(sin(x)**3, sin, cos, h, 4, False) + (1 - cos(x)**2)*sin(x) + >>> T(sin(x)**6, sin, cos, h, 6, False) + (1 - cos(x)**2)**3 + >>> T(sin(x)**6, sin, cos, h, 6, True) + sin(x)**6 + >>> T(sin(x)**8, sin, cos, h, 10, True) + (1 - cos(x)**2)**4 + """ + + def _f(rv): + # I'm not sure if this transformation should target all even powers + # or only those expressible as powers of 2. Also, should it only + # make the changes in powers that appear in sums -- making an isolated + # change is not going to allow a simplification as far as I can tell. + if not (rv.is_Pow and rv.base.func == f): + return rv + if not rv.exp.is_real: + return rv + + if (rv.exp < 0) == True: + return rv + if (rv.exp > max) == True: + return rv + if rv.exp == 1: + return rv + if rv.exp == 2: + return h(g(rv.base.args[0])**2) + else: + if rv.exp % 2 == 1: + e = rv.exp//2 + return f(rv.base.args[0])*h(g(rv.base.args[0])**2)**e + elif rv.exp == 4: + e = 2 + elif not pow: + if rv.exp % 2: + return rv + e = rv.exp//2 + else: + p = perfect_power(rv.exp) + if not p: + return rv + e = rv.exp//2 + return h(g(rv.base.args[0])**2)**e + + return bottom_up(rv, _f) + + +def TR5(rv, max=4, pow=False): + """Replacement of sin**2 with 1 - cos(x)**2. + + See _TR56 docstring for advanced use of ``max`` and ``pow``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR5 + >>> from sympy.abc import x + >>> from sympy import sin + >>> TR5(sin(x)**2) + 1 - cos(x)**2 + >>> TR5(sin(x)**-2) # unchanged + sin(x)**(-2) + >>> TR5(sin(x)**4) + (1 - cos(x)**2)**2 + """ + return _TR56(rv, sin, cos, lambda x: 1 - x, max=max, pow=pow) + + +def TR6(rv, max=4, pow=False): + """Replacement of cos**2 with 1 - sin(x)**2. + + See _TR56 docstring for advanced use of ``max`` and ``pow``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR6 + >>> from sympy.abc import x + >>> from sympy import cos + >>> TR6(cos(x)**2) + 1 - sin(x)**2 + >>> TR6(cos(x)**-2) #unchanged + cos(x)**(-2) + >>> TR6(cos(x)**4) + (1 - sin(x)**2)**2 + """ + return _TR56(rv, cos, sin, lambda x: 1 - x, max=max, pow=pow) + + +def TR7(rv): + """Lowering the degree of cos(x)**2. + + Examples + ======== + + >>> from sympy.simplify.fu import TR7 + >>> from sympy.abc import x + >>> from sympy import cos + >>> TR7(cos(x)**2) + cos(2*x)/2 + 1/2 + >>> TR7(cos(x)**2 + 1) + cos(2*x)/2 + 3/2 + + """ + + def f(rv): + if not (rv.is_Pow and rv.base.func == cos and rv.exp == 2): + return rv + return (1 + cos(2*rv.base.args[0]))/2 + + return bottom_up(rv, f) + + +def TR8(rv, first=True): + """Converting products of ``cos`` and/or ``sin`` to a sum or + difference of ``cos`` and or ``sin`` terms. + + Examples + ======== + + >>> from sympy.simplify.fu import TR8 + >>> from sympy import cos, sin + >>> TR8(cos(2)*cos(3)) + cos(5)/2 + cos(1)/2 + >>> TR8(cos(2)*sin(3)) + sin(5)/2 + sin(1)/2 + >>> TR8(sin(2)*sin(3)) + -cos(5)/2 + cos(1)/2 + """ + + def f(rv): + if not ( + rv.is_Mul or + rv.is_Pow and + rv.base.func in (cos, sin) and + (rv.exp.is_integer or rv.base.is_positive)): + return rv + + if first: + n, d = [expand_mul(i) for i in rv.as_numer_denom()] + newn = TR8(n, first=False) + newd = TR8(d, first=False) + if newn != n or newd != d: + rv = gcd_terms(newn/newd) + if rv.is_Mul and rv.args[0].is_Rational and \ + len(rv.args) == 2 and rv.args[1].is_Add: + rv = Mul(*rv.as_coeff_Mul()) + return rv + + args = {cos: [], sin: [], None: []} + for a in Mul.make_args(rv): + if a.func in (cos, sin): + args[type(a)].append(a.args[0]) + elif (a.is_Pow and a.exp.is_Integer and a.exp > 0 and \ + a.base.func in (cos, sin)): + # XXX this is ok but pathological expression could be handled + # more efficiently as in TRmorrie + args[type(a.base)].extend([a.base.args[0]]*a.exp) + else: + args[None].append(a) + c = args[cos] + s = args[sin] + if not (c and s or len(c) > 1 or len(s) > 1): + return rv + + args = args[None] + n = min(len(c), len(s)) + for i in range(n): + a1 = s.pop() + a2 = c.pop() + args.append((sin(a1 + a2) + sin(a1 - a2))/2) + while len(c) > 1: + a1 = c.pop() + a2 = c.pop() + args.append((cos(a1 + a2) + cos(a1 - a2))/2) + if c: + args.append(cos(c.pop())) + while len(s) > 1: + a1 = s.pop() + a2 = s.pop() + args.append((-cos(a1 + a2) + cos(a1 - a2))/2) + if s: + args.append(sin(s.pop())) + return TR8(expand_mul(Mul(*args))) + + return bottom_up(rv, f) + + +def TR9(rv): + """Sum of ``cos`` or ``sin`` terms as a product of ``cos`` or ``sin``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR9 + >>> from sympy import cos, sin + >>> TR9(cos(1) + cos(2)) + 2*cos(1/2)*cos(3/2) + >>> TR9(cos(1) + 2*sin(1) + 2*sin(2)) + cos(1) + 4*sin(3/2)*cos(1/2) + + If no change is made by TR9, no re-arrangement of the + expression will be made. For example, though factoring + of common term is attempted, if the factored expression + was not changed, the original expression will be returned: + + >>> TR9(cos(3) + cos(3)*cos(2)) + cos(3) + cos(2)*cos(3) + + """ + + def f(rv): + if not rv.is_Add: + return rv + + def do(rv, first=True): + # cos(a)+/-cos(b) can be combined into a product of cosines and + # sin(a)+/-sin(b) can be combined into a product of cosine and + # sine. + # + # If there are more than two args, the pairs which "work" will + # have a gcd extractable and the remaining two terms will have + # the above structure -- all pairs must be checked to find the + # ones that work. args that don't have a common set of symbols + # are skipped since this doesn't lead to a simpler formula and + # also has the arbitrariness of combining, for example, the x + # and y term instead of the y and z term in something like + # cos(x) + cos(y) + cos(z). + + if not rv.is_Add: + return rv + + args = list(ordered(rv.args)) + if len(args) != 2: + hit = False + for i in range(len(args)): + ai = args[i] + if ai is None: + continue + for j in range(i + 1, len(args)): + aj = args[j] + if aj is None: + continue + was = ai + aj + new = do(was) + if new != was: + args[i] = new # update in place + args[j] = None + hit = True + break # go to next i + if hit: + rv = Add(*[_f for _f in args if _f]) + if rv.is_Add: + rv = do(rv) + + return rv + + # two-arg Add + split = trig_split(*args) + if not split: + return rv + gcd, n1, n2, a, b, iscos = split + + # application of rule if possible + if iscos: + if n1 == n2: + return gcd*n1*2*cos((a + b)/2)*cos((a - b)/2) + if n1 < 0: + a, b = b, a + return -2*gcd*sin((a + b)/2)*sin((a - b)/2) + else: + if n1 == n2: + return gcd*n1*2*sin((a + b)/2)*cos((a - b)/2) + if n1 < 0: + a, b = b, a + return 2*gcd*cos((a + b)/2)*sin((a - b)/2) + + return process_common_addends(rv, do) # DON'T sift by free symbols + + return bottom_up(rv, f) + + +def TR10(rv, first=True): + """Separate sums in ``cos`` and ``sin``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR10 + >>> from sympy.abc import a, b, c + >>> from sympy import cos, sin + >>> TR10(cos(a + b)) + -sin(a)*sin(b) + cos(a)*cos(b) + >>> TR10(sin(a + b)) + sin(a)*cos(b) + sin(b)*cos(a) + >>> TR10(sin(a + b + c)) + (-sin(a)*sin(b) + cos(a)*cos(b))*sin(c) + \ + (sin(a)*cos(b) + sin(b)*cos(a))*cos(c) + """ + + def f(rv): + if rv.func not in (cos, sin): + return rv + + f = rv.func + arg = rv.args[0] + if arg.is_Add: + if first: + args = list(ordered(arg.args)) + else: + args = list(arg.args) + a = args.pop() + b = Add._from_args(args) + if b.is_Add: + if f == sin: + return sin(a)*TR10(cos(b), first=False) + \ + cos(a)*TR10(sin(b), first=False) + else: + return cos(a)*TR10(cos(b), first=False) - \ + sin(a)*TR10(sin(b), first=False) + else: + if f == sin: + return sin(a)*cos(b) + cos(a)*sin(b) + else: + return cos(a)*cos(b) - sin(a)*sin(b) + return rv + + return bottom_up(rv, f) + + +def TR10i(rv): + """Sum of products to function of sum. + + Examples + ======== + + >>> from sympy.simplify.fu import TR10i + >>> from sympy import cos, sin, sqrt + >>> from sympy.abc import x + + >>> TR10i(cos(1)*cos(3) + sin(1)*sin(3)) + cos(2) + >>> TR10i(cos(1)*sin(3) + sin(1)*cos(3) + cos(3)) + cos(3) + sin(4) + >>> TR10i(sqrt(2)*cos(x)*x + sqrt(6)*sin(x)*x) + 2*sqrt(2)*x*sin(x + pi/6) + + """ + def f(rv): + if not rv.is_Add: + return rv + + def do(rv, first=True): + # args which can be expressed as A*(cos(a)*cos(b)+/-sin(a)*sin(b)) + # or B*(cos(a)*sin(b)+/-cos(b)*sin(a)) can be combined into + # A*f(a+/-b) where f is either sin or cos. + # + # If there are more than two args, the pairs which "work" will have + # a gcd extractable and the remaining two terms will have the above + # structure -- all pairs must be checked to find the ones that + # work. + + if not rv.is_Add: + return rv + + args = list(ordered(rv.args)) + if len(args) != 2: + hit = False + for i in range(len(args)): + ai = args[i] + if ai is None: + continue + for j in range(i + 1, len(args)): + aj = args[j] + if aj is None: + continue + was = ai + aj + new = do(was) + if new != was: + args[i] = new # update in place + args[j] = None + hit = True + break # go to next i + if hit: + rv = Add(*[_f for _f in args if _f]) + if rv.is_Add: + rv = do(rv) + + return rv + + # two-arg Add + split = trig_split(*args, two=True) + if not split: + return rv + gcd, n1, n2, a, b, same = split + + # identify and get c1 to be cos then apply rule if possible + if same: # coscos, sinsin + gcd = n1*gcd + if n1 == n2: + return gcd*cos(a - b) + return gcd*cos(a + b) + else: #cossin, cossin + gcd = n1*gcd + if n1 == n2: + return gcd*sin(a + b) + return gcd*sin(b - a) + + rv = process_common_addends( + rv, do, lambda x: tuple(ordered(x.free_symbols))) + + # need to check for inducible pairs in ratio of sqrt(3):1 that + # appeared in different lists when sorting by coefficient + while rv.is_Add: + byrad = defaultdict(list) + for a in rv.args: + hit = 0 + if a.is_Mul: + for ai in a.args: + if ai.is_Pow and ai.exp is S.Half and \ + ai.base.is_Integer: + byrad[ai].append(a) + hit = 1 + break + if not hit: + byrad[S.One].append(a) + + # no need to check all pairs -- just check for the onees + # that have the right ratio + args = [] + for a in byrad: + for b in [_ROOT3()*a, _invROOT3()]: + if b in byrad: + for i in range(len(byrad[a])): + if byrad[a][i] is None: + continue + for j in range(len(byrad[b])): + if byrad[b][j] is None: + continue + was = Add(byrad[a][i] + byrad[b][j]) + new = do(was) + if new != was: + args.append(new) + byrad[a][i] = None + byrad[b][j] = None + break + if args: + rv = Add(*(args + [Add(*[_f for _f in v if _f]) + for v in byrad.values()])) + else: + rv = do(rv) # final pass to resolve any new inducible pairs + break + + return rv + + return bottom_up(rv, f) + + +def TR11(rv, base=None): + """Function of double angle to product. The ``base`` argument can be used + to indicate what is the un-doubled argument, e.g. if 3*pi/7 is the base + then cosine and sine functions with argument 6*pi/7 will be replaced. + + Examples + ======== + + >>> from sympy.simplify.fu import TR11 + >>> from sympy import cos, sin, pi + >>> from sympy.abc import x + >>> TR11(sin(2*x)) + 2*sin(x)*cos(x) + >>> TR11(cos(2*x)) + -sin(x)**2 + cos(x)**2 + >>> TR11(sin(4*x)) + 4*(-sin(x)**2 + cos(x)**2)*sin(x)*cos(x) + >>> TR11(sin(4*x/3)) + 4*(-sin(x/3)**2 + cos(x/3)**2)*sin(x/3)*cos(x/3) + + If the arguments are simply integers, no change is made + unless a base is provided: + + >>> TR11(cos(2)) + cos(2) + >>> TR11(cos(4), 2) + -sin(2)**2 + cos(2)**2 + + There is a subtle issue here in that autosimplification will convert + some higher angles to lower angles + + >>> cos(6*pi/7) + cos(3*pi/7) + -cos(pi/7) + cos(3*pi/7) + + The 6*pi/7 angle is now pi/7 but can be targeted with TR11 by supplying + the 3*pi/7 base: + + >>> TR11(_, 3*pi/7) + -sin(3*pi/7)**2 + cos(3*pi/7)**2 + cos(3*pi/7) + + """ + + def f(rv): + if rv.func not in (cos, sin): + return rv + + if base: + f = rv.func + t = f(base*2) + co = S.One + if t.is_Mul: + co, t = t.as_coeff_Mul() + if t.func not in (cos, sin): + return rv + if rv.args[0] == t.args[0]: + c = cos(base) + s = sin(base) + if f is cos: + return (c**2 - s**2)/co + else: + return 2*c*s/co + return rv + + elif not rv.args[0].is_Number: + # make a change if the leading coefficient's numerator is + # divisible by 2 + c, m = rv.args[0].as_coeff_Mul(rational=True) + if c.p % 2 == 0: + arg = c.p//2*m/c.q + c = TR11(cos(arg)) + s = TR11(sin(arg)) + if rv.func == sin: + rv = 2*s*c + else: + rv = c**2 - s**2 + return rv + + return bottom_up(rv, f) + + +def _TR11(rv): + """ + Helper for TR11 to find half-arguments for sin in factors of + num/den that appear in cos or sin factors in the den/num. + + Examples + ======== + + >>> from sympy.simplify.fu import TR11, _TR11 + >>> from sympy import cos, sin + >>> from sympy.abc import x + >>> TR11(sin(x/3)/(cos(x/6))) + sin(x/3)/cos(x/6) + >>> _TR11(sin(x/3)/(cos(x/6))) + 2*sin(x/6) + >>> TR11(sin(x/6)/(sin(x/3))) + sin(x/6)/sin(x/3) + >>> _TR11(sin(x/6)/(sin(x/3))) + 1/(2*cos(x/6)) + + """ + def f(rv): + if not isinstance(rv, Expr): + return rv + + def sincos_args(flat): + # find arguments of sin and cos that + # appears as bases in args of flat + # and have Integer exponents + args = defaultdict(set) + for fi in Mul.make_args(flat): + b, e = fi.as_base_exp() + if e.is_Integer and e > 0: + if b.func in (cos, sin): + args[type(b)].add(b.args[0]) + return args + num_args, den_args = map(sincos_args, rv.as_numer_denom()) + def handle_match(rv, num_args, den_args): + # for arg in sin args of num_args, look for arg/2 + # in den_args and pass this half-angle to TR11 + # for handling in rv + for narg in num_args[sin]: + half = narg/2 + if half in den_args[cos]: + func = cos + elif half in den_args[sin]: + func = sin + else: + continue + rv = TR11(rv, half) + den_args[func].remove(half) + return rv + # sin in num, sin or cos in den + rv = handle_match(rv, num_args, den_args) + # sin in den, sin or cos in num + rv = handle_match(rv, den_args, num_args) + return rv + + return bottom_up(rv, f) + + +def TR12(rv, first=True): + """Separate sums in ``tan``. + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy import tan + >>> from sympy.simplify.fu import TR12 + >>> TR12(tan(x + y)) + (tan(x) + tan(y))/(-tan(x)*tan(y) + 1) + """ + + def f(rv): + if not rv.func == tan: + return rv + + arg = rv.args[0] + if arg.is_Add: + if first: + args = list(ordered(arg.args)) + else: + args = list(arg.args) + a = args.pop() + b = Add._from_args(args) + if b.is_Add: + tb = TR12(tan(b), first=False) + else: + tb = tan(b) + return (tan(a) + tb)/(1 - tan(a)*tb) + return rv + + return bottom_up(rv, f) + + +def TR12i(rv): + """Combine tan arguments as + (tan(y) + tan(x))/(tan(x)*tan(y) - 1) -> -tan(x + y). + + Examples + ======== + + >>> from sympy.simplify.fu import TR12i + >>> from sympy import tan + >>> from sympy.abc import a, b, c + >>> ta, tb, tc = [tan(i) for i in (a, b, c)] + >>> TR12i((ta + tb)/(-ta*tb + 1)) + tan(a + b) + >>> TR12i((ta + tb)/(ta*tb - 1)) + -tan(a + b) + >>> TR12i((-ta - tb)/(ta*tb - 1)) + tan(a + b) + >>> eq = (ta + tb)/(-ta*tb + 1)**2*(-3*ta - 3*tc)/(2*(ta*tc - 1)) + >>> TR12i(eq.expand()) + -3*tan(a + b)*tan(a + c)/(2*(tan(a) + tan(b) - 1)) + """ + def f(rv): + if not (rv.is_Add or rv.is_Mul or rv.is_Pow): + return rv + + n, d = rv.as_numer_denom() + if not d.args or not n.args: + return rv + + dok = {} + + def ok(di): + m = as_f_sign_1(di) + if m: + g, f, s = m + if s is S.NegativeOne and f.is_Mul and len(f.args) == 2 and \ + all(isinstance(fi, tan) for fi in f.args): + return g, f + + d_args = list(Mul.make_args(d)) + for i, di in enumerate(d_args): + m = ok(di) + if m: + g, t = m + s = Add(*[_.args[0] for _ in t.args]) + dok[s] = S.One + d_args[i] = g + continue + if di.is_Add: + di = factor(di) + if di.is_Mul: + d_args.extend(di.args) + d_args[i] = S.One + elif di.is_Pow and (di.exp.is_integer or di.base.is_positive): + m = ok(di.base) + if m: + g, t = m + s = Add(*[_.args[0] for _ in t.args]) + dok[s] = di.exp + d_args[i] = g**di.exp + else: + di = factor(di) + if di.is_Mul: + d_args.extend(di.args) + d_args[i] = S.One + if not dok: + return rv + + def ok(ni): + if ni.is_Add and len(ni.args) == 2: + a, b = ni.args + if isinstance(a, tan) and isinstance(b, tan): + return a, b + n_args = list(Mul.make_args(factor_terms(n))) + hit = False + for i, ni in enumerate(n_args): + m = ok(ni) + if not m: + m = ok(-ni) + if m: + n_args[i] = S.NegativeOne + else: + if ni.is_Add: + ni = factor(ni) + if ni.is_Mul: + n_args.extend(ni.args) + n_args[i] = S.One + continue + elif ni.is_Pow and ( + ni.exp.is_integer or ni.base.is_positive): + m = ok(ni.base) + if m: + n_args[i] = S.One + else: + ni = factor(ni) + if ni.is_Mul: + n_args.extend(ni.args) + n_args[i] = S.One + continue + else: + continue + else: + n_args[i] = S.One + hit = True + s = Add(*[_.args[0] for _ in m]) + ed = dok[s] + newed = ed.extract_additively(S.One) + if newed is not None: + if newed: + dok[s] = newed + else: + dok.pop(s) + n_args[i] *= -tan(s) + + if hit: + rv = Mul(*n_args)/Mul(*d_args)/Mul(*[(Add(*[ + tan(a) for a in i.args]) - 1)**e for i, e in dok.items()]) + + return rv + + return bottom_up(rv, f) + + +def TR13(rv): + """Change products of ``tan`` or ``cot``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR13 + >>> from sympy import tan, cot + >>> TR13(tan(3)*tan(2)) + -tan(2)/tan(5) - tan(3)/tan(5) + 1 + >>> TR13(cot(3)*cot(2)) + cot(2)*cot(5) + 1 + cot(3)*cot(5) + """ + + def f(rv): + if not rv.is_Mul: + return rv + + # XXX handle products of powers? or let power-reducing handle it? + args = {tan: [], cot: [], None: []} + for a in Mul.make_args(rv): + if a.func in (tan, cot): + args[type(a)].append(a.args[0]) + else: + args[None].append(a) + t = args[tan] + c = args[cot] + if len(t) < 2 and len(c) < 2: + return rv + args = args[None] + while len(t) > 1: + t1 = t.pop() + t2 = t.pop() + args.append(1 - (tan(t1)/tan(t1 + t2) + tan(t2)/tan(t1 + t2))) + if t: + args.append(tan(t.pop())) + while len(c) > 1: + t1 = c.pop() + t2 = c.pop() + args.append(1 + cot(t1)*cot(t1 + t2) + cot(t2)*cot(t1 + t2)) + if c: + args.append(cot(c.pop())) + return Mul(*args) + + return bottom_up(rv, f) + + +def TRmorrie(rv): + """Returns cos(x)*cos(2*x)*...*cos(2**(k-1)*x) -> sin(2**k*x)/(2**k*sin(x)) + + Examples + ======== + + >>> from sympy.simplify.fu import TRmorrie, TR8, TR3 + >>> from sympy.abc import x + >>> from sympy import Mul, cos, pi + >>> TRmorrie(cos(x)*cos(2*x)) + sin(4*x)/(4*sin(x)) + >>> TRmorrie(7*Mul(*[cos(x) for x in range(10)])) + 7*sin(12)*sin(16)*cos(5)*cos(7)*cos(9)/(64*sin(1)*sin(3)) + + Sometimes autosimplification will cause a power to be + not recognized. e.g. in the following, cos(4*pi/7) automatically + simplifies to -cos(3*pi/7) so only 2 of the 3 terms are + recognized: + + >>> TRmorrie(cos(pi/7)*cos(2*pi/7)*cos(4*pi/7)) + -sin(3*pi/7)*cos(3*pi/7)/(4*sin(pi/7)) + + A touch by TR8 resolves the expression to a Rational + + >>> TR8(_) + -1/8 + + In this case, if eq is unsimplified, the answer is obtained + directly: + + >>> eq = cos(pi/9)*cos(2*pi/9)*cos(3*pi/9)*cos(4*pi/9) + >>> TRmorrie(eq) + 1/16 + + But if angles are made canonical with TR3 then the answer + is not simplified without further work: + + >>> TR3(eq) + sin(pi/18)*cos(pi/9)*cos(2*pi/9)/2 + >>> TRmorrie(_) + sin(pi/18)*sin(4*pi/9)/(8*sin(pi/9)) + >>> TR8(_) + cos(7*pi/18)/(16*sin(pi/9)) + >>> TR3(_) + 1/16 + + The original expression would have resolve to 1/16 directly with TR8, + however: + + >>> TR8(eq) + 1/16 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Morrie%27s_law + + """ + + def f(rv, first=True): + if not rv.is_Mul: + return rv + if first: + n, d = rv.as_numer_denom() + return f(n, 0)/f(d, 0) + + args = defaultdict(list) + coss = {} + other = [] + for c in rv.args: + b, e = c.as_base_exp() + if e.is_Integer and isinstance(b, cos): + co, a = b.args[0].as_coeff_Mul() + args[a].append(co) + coss[b] = e + else: + other.append(c) + + new = [] + for a in args: + c = args[a] + c.sort() + while c: + k = 0 + cc = ci = c[0] + while cc in c: + k += 1 + cc *= 2 + if k > 1: + newarg = sin(2**k*ci*a)/2**k/sin(ci*a) + # see how many times this can be taken + take = None + ccs = [] + for i in range(k): + cc /= 2 + key = cos(a*cc, evaluate=False) + ccs.append(cc) + take = min(coss[key], take or coss[key]) + # update exponent counts + for i in range(k): + cc = ccs.pop() + key = cos(a*cc, evaluate=False) + coss[key] -= take + if not coss[key]: + c.remove(cc) + new.append(newarg**take) + else: + b = cos(c.pop(0)*a) + other.append(b**coss[b]) + + if new: + rv = Mul(*(new + other + [ + cos(k*a, evaluate=False) for a in args for k in args[a]])) + + return rv + + return bottom_up(rv, f) + + +def TR14(rv, first=True): + """Convert factored powers of sin and cos identities into simpler + expressions. + + Examples + ======== + + >>> from sympy.simplify.fu import TR14 + >>> from sympy.abc import x, y + >>> from sympy import cos, sin + >>> TR14((cos(x) - 1)*(cos(x) + 1)) + -sin(x)**2 + >>> TR14((sin(x) - 1)*(sin(x) + 1)) + -cos(x)**2 + >>> p1 = (cos(x) + 1)*(cos(x) - 1) + >>> p2 = (cos(y) - 1)*2*(cos(y) + 1) + >>> p3 = (3*(cos(y) - 1))*(3*(cos(y) + 1)) + >>> TR14(p1*p2*p3*(x - 1)) + -18*(x - 1)*sin(x)**2*sin(y)**4 + + """ + + def f(rv): + if not rv.is_Mul: + return rv + + if first: + # sort them by location in numerator and denominator + # so the code below can just deal with positive exponents + n, d = rv.as_numer_denom() + if d is not S.One: + newn = TR14(n, first=False) + newd = TR14(d, first=False) + if newn != n or newd != d: + rv = newn/newd + return rv + + other = [] + process = [] + for a in rv.args: + if a.is_Pow: + b, e = a.as_base_exp() + if not (e.is_integer or b.is_positive): + other.append(a) + continue + a = b + else: + e = S.One + m = as_f_sign_1(a) + if not m or m[1].func not in (cos, sin): + if e is S.One: + other.append(a) + else: + other.append(a**e) + continue + g, f, si = m + process.append((g, e.is_Number, e, f, si, a)) + + # sort them to get like terms next to each other + process = list(ordered(process)) + + # keep track of whether there was any change + nother = len(other) + + # access keys + keys = (g, t, e, f, si, a) = list(range(6)) + + while process: + A = process.pop(0) + if process: + B = process[0] + + if A[e].is_Number and B[e].is_Number: + # both exponents are numbers + if A[f] == B[f]: + if A[si] != B[si]: + B = process.pop(0) + take = min(A[e], B[e]) + + # reinsert any remainder + # the B will likely sort after A so check it first + if B[e] != take: + rem = [B[i] for i in keys] + rem[e] -= take + process.insert(0, rem) + elif A[e] != take: + rem = [A[i] for i in keys] + rem[e] -= take + process.insert(0, rem) + + if isinstance(A[f], cos): + t = sin + else: + t = cos + other.append((-A[g]*B[g]*t(A[f].args[0])**2)**take) + continue + + elif A[e] == B[e]: + # both exponents are equal symbols + if A[f] == B[f]: + if A[si] != B[si]: + B = process.pop(0) + take = A[e] + if isinstance(A[f], cos): + t = sin + else: + t = cos + other.append((-A[g]*B[g]*t(A[f].args[0])**2)**take) + continue + + # either we are done or neither condition above applied + other.append(A[a]**A[e]) + + if len(other) != nother: + rv = Mul(*other) + + return rv + + return bottom_up(rv, f) + + +def TR15(rv, max=4, pow=False): + """Convert sin(x)**-2 to 1 + cot(x)**2. + + See _TR56 docstring for advanced use of ``max`` and ``pow``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR15 + >>> from sympy.abc import x + >>> from sympy import sin + >>> TR15(1 - 1/sin(x)**2) + -cot(x)**2 + + """ + + def f(rv): + if not (isinstance(rv, Pow) and isinstance(rv.base, sin)): + return rv + + e = rv.exp + if e % 2 == 1: + return TR15(rv.base**(e + 1))/rv.base + + ia = 1/rv + a = _TR56(ia, sin, cot, lambda x: 1 + x, max=max, pow=pow) + if a != ia: + rv = a + return rv + + return bottom_up(rv, f) + + +def TR16(rv, max=4, pow=False): + """Convert cos(x)**-2 to 1 + tan(x)**2. + + See _TR56 docstring for advanced use of ``max`` and ``pow``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR16 + >>> from sympy.abc import x + >>> from sympy import cos + >>> TR16(1 - 1/cos(x)**2) + -tan(x)**2 + + """ + + def f(rv): + if not (isinstance(rv, Pow) and isinstance(rv.base, cos)): + return rv + + e = rv.exp + if e % 2 == 1: + return TR15(rv.base**(e + 1))/rv.base + + ia = 1/rv + a = _TR56(ia, cos, tan, lambda x: 1 + x, max=max, pow=pow) + if a != ia: + rv = a + return rv + + return bottom_up(rv, f) + + +def TR111(rv): + """Convert f(x)**-i to g(x)**i where either ``i`` is an integer + or the base is positive and f, g are: tan, cot; sin, csc; or cos, sec. + + Examples + ======== + + >>> from sympy.simplify.fu import TR111 + >>> from sympy.abc import x + >>> from sympy import tan + >>> TR111(1 - 1/tan(x)**2) + 1 - cot(x)**2 + + """ + + def f(rv): + if not ( + isinstance(rv, Pow) and + (rv.base.is_positive or rv.exp.is_integer and rv.exp.is_negative)): + return rv + + if isinstance(rv.base, tan): + return cot(rv.base.args[0])**-rv.exp + elif isinstance(rv.base, sin): + return csc(rv.base.args[0])**-rv.exp + elif isinstance(rv.base, cos): + return sec(rv.base.args[0])**-rv.exp + return rv + + return bottom_up(rv, f) + + +def TR22(rv, max=4, pow=False): + """Convert tan(x)**2 to sec(x)**2 - 1 and cot(x)**2 to csc(x)**2 - 1. + + See _TR56 docstring for advanced use of ``max`` and ``pow``. + + Examples + ======== + + >>> from sympy.simplify.fu import TR22 + >>> from sympy.abc import x + >>> from sympy import tan, cot + >>> TR22(1 + tan(x)**2) + sec(x)**2 + >>> TR22(1 + cot(x)**2) + csc(x)**2 + + """ + + def f(rv): + if not (isinstance(rv, Pow) and rv.base.func in (cot, tan)): + return rv + + rv = _TR56(rv, tan, sec, lambda x: x - 1, max=max, pow=pow) + rv = _TR56(rv, cot, csc, lambda x: x - 1, max=max, pow=pow) + return rv + + return bottom_up(rv, f) + + +def TRpower(rv): + """Convert sin(x)**n and cos(x)**n with positive n to sums. + + Examples + ======== + + >>> from sympy.simplify.fu import TRpower + >>> from sympy.abc import x + >>> from sympy import cos, sin + >>> TRpower(sin(x)**6) + -15*cos(2*x)/32 + 3*cos(4*x)/16 - cos(6*x)/32 + 5/16 + >>> TRpower(sin(x)**3*cos(2*x)**4) + (3*sin(x)/4 - sin(3*x)/4)*(cos(4*x)/2 + cos(8*x)/8 + 3/8) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/List_of_trigonometric_identities#Power-reduction_formulae + + """ + + def f(rv): + if not (isinstance(rv, Pow) and isinstance(rv.base, (sin, cos))): + return rv + b, n = rv.as_base_exp() + x = b.args[0] + if n.is_Integer and n.is_positive: + if n.is_odd and isinstance(b, cos): + rv = 2**(1-n)*Add(*[binomial(n, k)*cos((n - 2*k)*x) + for k in range((n + 1)/2)]) + elif n.is_odd and isinstance(b, sin): + rv = 2**(1-n)*S.NegativeOne**((n-1)/2)*Add(*[binomial(n, k)* + S.NegativeOne**k*sin((n - 2*k)*x) for k in range((n + 1)/2)]) + elif n.is_even and isinstance(b, cos): + rv = 2**(1-n)*Add(*[binomial(n, k)*cos((n - 2*k)*x) + for k in range(n/2)]) + elif n.is_even and isinstance(b, sin): + rv = 2**(1-n)*S.NegativeOne**(n/2)*Add(*[binomial(n, k)* + S.NegativeOne**k*cos((n - 2*k)*x) for k in range(n/2)]) + if n.is_even: + rv += 2**(-n)*binomial(n, n/2) + return rv + + return bottom_up(rv, f) + + +def L(rv): + """Return count of trigonometric functions in expression. + + Examples + ======== + + >>> from sympy.simplify.fu import L + >>> from sympy.abc import x + >>> from sympy import cos, sin + >>> L(cos(x)+sin(x)) + 2 + """ + return S(rv.count(TrigonometricFunction)) + + +# ============== end of basic Fu-like tools ===================== + +if SYMPY_DEBUG: + (TR0, TR1, TR2, TR3, TR4, TR5, TR6, TR7, TR8, TR9, TR10, TR11, TR12, TR13, + TR2i, TRmorrie, TR14, TR15, TR16, TR12i, TR111, TR22 + )= list(map(debug, + (TR0, TR1, TR2, TR3, TR4, TR5, TR6, TR7, TR8, TR9, TR10, TR11, TR12, TR13, + TR2i, TRmorrie, TR14, TR15, TR16, TR12i, TR111, TR22))) + + +# tuples are chains -- (f, g) -> lambda x: g(f(x)) +# lists are choices -- [f, g] -> lambda x: min(f(x), g(x), key=objective) + +CTR1 = [(TR5, TR0), (TR6, TR0), identity] + +CTR2 = (TR11, [(TR5, TR0), (TR6, TR0), TR0]) + +CTR3 = [(TRmorrie, TR8, TR0), (TRmorrie, TR8, TR10i, TR0), identity] + +CTR4 = [(TR4, TR10i), identity] + +RL1 = (TR4, TR3, TR4, TR12, TR4, TR13, TR4, TR0) + + +# XXX it's a little unclear how this one is to be implemented +# see Fu paper of reference, page 7. What is the Union symbol referring to? +# The diagram shows all these as one chain of transformations, but the +# text refers to them being applied independently. Also, a break +# if L starts to increase has not been implemented. +RL2 = [ + (TR4, TR3, TR10, TR4, TR3, TR11), + (TR5, TR7, TR11, TR4), + (CTR3, CTR1, TR9, CTR2, TR4, TR9, TR9, CTR4), + identity, + ] + + +def fu(rv, measure=lambda x: (L(x), x.count_ops())): + """Attempt to simplify expression by using transformation rules given + in the algorithm by Fu et al. + + :func:`fu` will try to minimize the objective function ``measure``. + By default this first minimizes the number of trig terms and then minimizes + the number of total operations. + + Examples + ======== + + >>> from sympy.simplify.fu import fu + >>> from sympy import cos, sin, tan, pi, S, sqrt + >>> from sympy.abc import x, y, a, b + + >>> fu(sin(50)**2 + cos(50)**2 + sin(pi/6)) + 3/2 + >>> fu(sqrt(6)*cos(x) + sqrt(2)*sin(x)) + 2*sqrt(2)*sin(x + pi/3) + + CTR1 example + + >>> eq = sin(x)**4 - cos(y)**2 + sin(y)**2 + 2*cos(x)**2 + >>> fu(eq) + cos(x)**4 - 2*cos(y)**2 + 2 + + CTR2 example + + >>> fu(S.Half - cos(2*x)/2) + sin(x)**2 + + CTR3 example + + >>> fu(sin(a)*(cos(b) - sin(b)) + cos(a)*(sin(b) + cos(b))) + sqrt(2)*sin(a + b + pi/4) + + CTR4 example + + >>> fu(sqrt(3)*cos(x)/2 + sin(x)/2) + sin(x + pi/3) + + Example 1 + + >>> fu(1-sin(2*x)**2/4-sin(y)**2-cos(x)**4) + -cos(x)**2 + cos(y)**2 + + Example 2 + + >>> fu(cos(4*pi/9)) + sin(pi/18) + >>> fu(cos(pi/9)*cos(2*pi/9)*cos(3*pi/9)*cos(4*pi/9)) + 1/16 + + Example 3 + + >>> fu(tan(7*pi/18)+tan(5*pi/18)-sqrt(3)*tan(5*pi/18)*tan(7*pi/18)) + -sqrt(3) + + Objective function example + + >>> fu(sin(x)/cos(x)) # default objective function + tan(x) + >>> fu(sin(x)/cos(x), measure=lambda x: -x.count_ops()) # maximize op count + sin(x)/cos(x) + + References + ========== + + .. [1] https://www.sciencedirect.com/science/article/pii/S0895717706001609 + """ + fRL1 = greedy(RL1, measure) + fRL2 = greedy(RL2, measure) + + was = rv + rv = sympify(rv) + if not isinstance(rv, Expr): + return rv.func(*[fu(a, measure=measure) for a in rv.args]) + rv = TR1(rv) + if rv.has(tan, cot): + rv1 = fRL1(rv) + if (measure(rv1) < measure(rv)): + rv = rv1 + if rv.has(tan, cot): + rv = TR2(rv) + if rv.has(sin, cos): + rv1 = fRL2(rv) + rv2 = TR8(TRmorrie(rv1)) + rv = min([was, rv, rv1, rv2], key=measure) + return min(TR2i(rv), rv, key=measure) + + +def process_common_addends(rv, do, key2=None, key1=True): + """Apply ``do`` to addends of ``rv`` that (if ``key1=True``) share at least + a common absolute value of their coefficient and the value of ``key2`` when + applied to the argument. If ``key1`` is False ``key2`` must be supplied and + will be the only key applied. + """ + + # collect by absolute value of coefficient and key2 + absc = defaultdict(list) + if key1: + for a in rv.args: + c, a = a.as_coeff_Mul() + if c < 0: + c = -c + a = -a # put the sign on `a` + absc[(c, key2(a) if key2 else 1)].append(a) + elif key2: + for a in rv.args: + absc[(S.One, key2(a))].append(a) + else: + raise ValueError('must have at least one key') + + args = [] + hit = False + for k in absc: + v = absc[k] + c, _ = k + if len(v) > 1: + e = Add(*v, evaluate=False) + new = do(e) + if new != e: + e = new + hit = True + args.append(c*e) + else: + args.append(c*v[0]) + if hit: + rv = Add(*args) + + return rv + + +fufuncs = ''' + TR0 TR1 TR2 TR3 TR4 TR5 TR6 TR7 TR8 TR9 TR10 TR10i TR11 + TR12 TR13 L TR2i TRmorrie TR12i + TR14 TR15 TR16 TR111 TR22'''.split() +FU = dict(list(zip(fufuncs, list(map(locals().get, fufuncs))))) + + +@cacheit +def _ROOT2(): + return sqrt(2) + + +@cacheit +def _ROOT3(): + return sqrt(3) + + +@cacheit +def _invROOT3(): + return 1/sqrt(3) + + +def trig_split(a, b, two=False): + """Return the gcd, s1, s2, a1, a2, bool where + + If two is False (default) then:: + a + b = gcd*(s1*f(a1) + s2*f(a2)) where f = cos if bool else sin + else: + if bool, a + b was +/- cos(a1)*cos(a2) +/- sin(a1)*sin(a2) and equals + n1*gcd*cos(a - b) if n1 == n2 else + n1*gcd*cos(a + b) + else a + b was +/- cos(a1)*sin(a2) +/- sin(a1)*cos(a2) and equals + n1*gcd*sin(a + b) if n1 = n2 else + n1*gcd*sin(b - a) + + Examples + ======== + + >>> from sympy.simplify.fu import trig_split + >>> from sympy.abc import x, y, z + >>> from sympy import cos, sin, sqrt + + >>> trig_split(cos(x), cos(y)) + (1, 1, 1, x, y, True) + >>> trig_split(2*cos(x), -2*cos(y)) + (2, 1, -1, x, y, True) + >>> trig_split(cos(x)*sin(y), cos(y)*sin(y)) + (sin(y), 1, 1, x, y, True) + + >>> trig_split(cos(x), -sqrt(3)*sin(x), two=True) + (2, 1, -1, x, pi/6, False) + >>> trig_split(cos(x), sin(x), two=True) + (sqrt(2), 1, 1, x, pi/4, False) + >>> trig_split(cos(x), -sin(x), two=True) + (sqrt(2), 1, -1, x, pi/4, False) + >>> trig_split(sqrt(2)*cos(x), -sqrt(6)*sin(x), two=True) + (2*sqrt(2), 1, -1, x, pi/6, False) + >>> trig_split(-sqrt(6)*cos(x), -sqrt(2)*sin(x), two=True) + (-2*sqrt(2), 1, 1, x, pi/3, False) + >>> trig_split(cos(x)/sqrt(6), sin(x)/sqrt(2), two=True) + (sqrt(6)/3, 1, 1, x, pi/6, False) + >>> trig_split(-sqrt(6)*cos(x)*sin(y), -sqrt(2)*sin(x)*sin(y), two=True) + (-2*sqrt(2)*sin(y), 1, 1, x, pi/3, False) + + >>> trig_split(cos(x), sin(x)) + >>> trig_split(cos(x), sin(z)) + >>> trig_split(2*cos(x), -sin(x)) + >>> trig_split(cos(x), -sqrt(3)*sin(x)) + >>> trig_split(cos(x)*cos(y), sin(x)*sin(z)) + >>> trig_split(cos(x)*cos(y), sin(x)*sin(y)) + >>> trig_split(-sqrt(6)*cos(x), sqrt(2)*sin(x)*sin(y), two=True) + """ + a, b = [Factors(i) for i in (a, b)] + ua, ub = a.normal(b) + gcd = a.gcd(b).as_expr() + n1 = n2 = 1 + if S.NegativeOne in ua.factors: + ua = ua.quo(S.NegativeOne) + n1 = -n1 + elif S.NegativeOne in ub.factors: + ub = ub.quo(S.NegativeOne) + n2 = -n2 + a, b = [i.as_expr() for i in (ua, ub)] + + def pow_cos_sin(a, two): + """Return ``a`` as a tuple (r, c, s) such that + ``a = (r or 1)*(c or 1)*(s or 1)``. + + Three arguments are returned (radical, c-factor, s-factor) as + long as the conditions set by ``two`` are met; otherwise None is + returned. If ``two`` is True there will be one or two non-None + values in the tuple: c and s or c and r or s and r or s or c with c + being a cosine function (if possible) else a sine, and s being a sine + function (if possible) else oosine. If ``two`` is False then there + will only be a c or s term in the tuple. + + ``two`` also require that either two cos and/or sin be present (with + the condition that if the functions are the same the arguments are + different or vice versa) or that a single cosine or a single sine + be present with an optional radical. + + If the above conditions dictated by ``two`` are not met then None + is returned. + """ + c = s = None + co = S.One + if a.is_Mul: + co, a = a.as_coeff_Mul() + if len(a.args) > 2 or not two: + return None + if a.is_Mul: + args = list(a.args) + else: + args = [a] + a = args.pop(0) + if isinstance(a, cos): + c = a + elif isinstance(a, sin): + s = a + elif a.is_Pow and a.exp is S.Half: # autoeval doesn't allow -1/2 + co *= a + else: + return None + if args: + b = args[0] + if isinstance(b, cos): + if c: + s = b + else: + c = b + elif isinstance(b, sin): + if s: + c = b + else: + s = b + elif b.is_Pow and b.exp is S.Half: + co *= b + else: + return None + return co if co is not S.One else None, c, s + elif isinstance(a, cos): + c = a + elif isinstance(a, sin): + s = a + if c is None and s is None: + return + co = co if co is not S.One else None + return co, c, s + + # get the parts + m = pow_cos_sin(a, two) + if m is None: + return + coa, ca, sa = m + m = pow_cos_sin(b, two) + if m is None: + return + cob, cb, sb = m + + # check them + if (not ca) and cb or ca and isinstance(ca, sin): + coa, ca, sa, cob, cb, sb = cob, cb, sb, coa, ca, sa + n1, n2 = n2, n1 + if not two: # need cos(x) and cos(y) or sin(x) and sin(y) + c = ca or sa + s = cb or sb + if not isinstance(c, s.func): + return None + return gcd, n1, n2, c.args[0], s.args[0], isinstance(c, cos) + else: + if not coa and not cob: + if (ca and cb and sa and sb): + if isinstance(ca, sa.func) is not isinstance(cb, sb.func): + return + args = {j.args for j in (ca, sa)} + if not all(i.args in args for i in (cb, sb)): + return + return gcd, n1, n2, ca.args[0], sa.args[0], isinstance(ca, sa.func) + if ca and sa or cb and sb or \ + two and (ca is None and sa is None or cb is None and sb is None): + return + c = ca or sa + s = cb or sb + if c.args != s.args: + return + if not coa: + coa = S.One + if not cob: + cob = S.One + if coa is cob: + gcd *= _ROOT2() + return gcd, n1, n2, c.args[0], pi/4, False + elif coa/cob == _ROOT3(): + gcd *= 2*cob + return gcd, n1, n2, c.args[0], pi/3, False + elif coa/cob == _invROOT3(): + gcd *= 2*coa + return gcd, n1, n2, c.args[0], pi/6, False + + +def as_f_sign_1(e): + """If ``e`` is a sum that can be written as ``g*(a + s)`` where + ``s`` is ``+/-1``, return ``g``, ``a``, and ``s`` where ``a`` does + not have a leading negative coefficient. + + Examples + ======== + + >>> from sympy.simplify.fu import as_f_sign_1 + >>> from sympy.abc import x + >>> as_f_sign_1(x + 1) + (1, x, 1) + >>> as_f_sign_1(x - 1) + (1, x, -1) + >>> as_f_sign_1(-x + 1) + (-1, x, -1) + >>> as_f_sign_1(-x - 1) + (-1, x, 1) + >>> as_f_sign_1(2*x + 2) + (2, x, 1) + """ + if not e.is_Add or len(e.args) != 2: + return + # exact match + a, b = e.args + if a in (S.NegativeOne, S.One): + g = S.One + if b.is_Mul and b.args[0].is_Number and b.args[0] < 0: + a, b = -a, -b + g = -g + return g, b, a + # gcd match + a, b = [Factors(i) for i in e.args] + ua, ub = a.normal(b) + gcd = a.gcd(b).as_expr() + if S.NegativeOne in ua.factors: + ua = ua.quo(S.NegativeOne) + n1 = -1 + n2 = 1 + elif S.NegativeOne in ub.factors: + ub = ub.quo(S.NegativeOne) + n1 = 1 + n2 = -1 + else: + n1 = n2 = 1 + a, b = [i.as_expr() for i in (ua, ub)] + if a is S.One: + a, b = b, a + n1, n2 = n2, n1 + if n1 == -1: + gcd = -gcd + n2 = -n2 + + if b is S.One: + return gcd, a, n2 + + +def _osborne(e, d): + """Replace all hyperbolic functions with trig functions using + the Osborne rule. + + Notes + ===== + + ``d`` is a dummy variable to prevent automatic evaluation + of trigonometric/hyperbolic functions. + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Hyperbolic_function + """ + + def f(rv): + if not isinstance(rv, HyperbolicFunction): + return rv + a = rv.args[0] + a = a*d if not a.is_Add else Add._from_args([i*d for i in a.args]) + if isinstance(rv, sinh): + return I*sin(a) + elif isinstance(rv, cosh): + return cos(a) + elif isinstance(rv, tanh): + return I*tan(a) + elif isinstance(rv, coth): + return cot(a)/I + elif isinstance(rv, sech): + return sec(a) + elif isinstance(rv, csch): + return csc(a)/I + else: + raise NotImplementedError('unhandled %s' % rv.func) + + return bottom_up(e, f) + + +def _osbornei(e, d): + """Replace all trig functions with hyperbolic functions using + the Osborne rule. + + Notes + ===== + + ``d`` is a dummy variable to prevent automatic evaluation + of trigonometric/hyperbolic functions. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Hyperbolic_function + """ + + def f(rv): + if not isinstance(rv, TrigonometricFunction): + return rv + const, x = rv.args[0].as_independent(d, as_Add=True) + a = x.xreplace({d: S.One}) + const*I + if isinstance(rv, sin): + return sinh(a)/I + elif isinstance(rv, cos): + return cosh(a) + elif isinstance(rv, tan): + return tanh(a)/I + elif isinstance(rv, cot): + return coth(a)*I + elif isinstance(rv, sec): + return sech(a) + elif isinstance(rv, csc): + return csch(a)*I + else: + raise NotImplementedError('unhandled %s' % rv.func) + + return bottom_up(e, f) + + +def hyper_as_trig(rv): + """Return an expression containing hyperbolic functions in terms + of trigonometric functions. Any trigonometric functions initially + present are replaced with Dummy symbols and the function to undo + the masking and the conversion back to hyperbolics is also returned. It + should always be true that:: + + t, f = hyper_as_trig(expr) + expr == f(t) + + Examples + ======== + + >>> from sympy.simplify.fu import hyper_as_trig, fu + >>> from sympy.abc import x + >>> from sympy import cosh, sinh + >>> eq = sinh(x)**2 + cosh(x)**2 + >>> t, f = hyper_as_trig(eq) + >>> f(fu(t)) + cosh(2*x) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Hyperbolic_function + """ + from sympy.simplify.simplify import signsimp + from sympy.simplify.radsimp import collect + + # mask off trig functions + trigs = rv.atoms(TrigonometricFunction) + reps = [(t, Dummy()) for t in trigs] + masked = rv.xreplace(dict(reps)) + + # get inversion substitutions in place + reps = [(v, k) for k, v in reps] + + d = Dummy() + + return _osborne(masked, d), lambda x: collect(signsimp( + _osbornei(x, d).xreplace(dict(reps))), S.ImaginaryUnit) + + +def sincos_to_sum(expr): + """Convert products and powers of sin and cos to sums. + + Explanation + =========== + + Applied power reduction TRpower first, then expands products, and + converts products to sums with TR8. + + Examples + ======== + + >>> from sympy.simplify.fu import sincos_to_sum + >>> from sympy.abc import x + >>> from sympy import cos, sin + >>> sincos_to_sum(16*sin(x)**3*cos(2*x)**2) + 7*sin(x) - 5*sin(3*x) + 3*sin(5*x) - sin(7*x) + """ + + if not expr.has(cos, sin): + return expr + else: + return TR8(expand_mul(TRpower(expr))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/gammasimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/gammasimp.py new file mode 100644 index 0000000000000000000000000000000000000000..aec20c56eb60efb8e1aadfb5bff3d1ba1ab51869 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/gammasimp.py @@ -0,0 +1,493 @@ +from sympy.core import Function, S, Mul, Pow, Add +from sympy.core.sorting import ordered, default_sort_key +from sympy.core.function import expand_func +from sympy.core.symbol import Dummy +from sympy.functions import gamma, sqrt, sin +from sympy.polys import factor, cancel +from sympy.utilities.iterables import sift, uniq + + +def gammasimp(expr): + r""" + Simplify expressions with gamma functions. + + Explanation + =========== + + This function takes as input an expression containing gamma + functions or functions that can be rewritten in terms of gamma + functions and tries to minimize the number of those functions and + reduce the size of their arguments. + + The algorithm works by rewriting all gamma functions as expressions + involving rising factorials (Pochhammer symbols) and applies + recurrence relations and other transformations applicable to rising + factorials, to reduce their arguments, possibly letting the resulting + rising factorial to cancel. Rising factorials with the second argument + being an integer are expanded into polynomial forms and finally all + other rising factorial are rewritten in terms of gamma functions. + + Then the following two steps are performed. + + 1. Reduce the number of gammas by applying the reflection theorem + gamma(x)*gamma(1-x) == pi/sin(pi*x). + 2. Reduce the number of gammas by applying the multiplication theorem + gamma(x)*gamma(x+1/n)*...*gamma(x+(n-1)/n) == C*gamma(n*x). + + It then reduces the number of prefactors by absorbing them into gammas + where possible and expands gammas with rational argument. + + All transformation rules can be found (or were derived from) here: + + .. [1] https://functions.wolfram.com/GammaBetaErf/Pochhammer/17/01/02/ + .. [2] https://functions.wolfram.com/GammaBetaErf/Pochhammer/27/01/0005/ + + Examples + ======== + + >>> from sympy.simplify import gammasimp + >>> from sympy import gamma, Symbol + >>> from sympy.abc import x + >>> n = Symbol('n', integer = True) + + >>> gammasimp(gamma(x)/gamma(x - 3)) + (x - 3)*(x - 2)*(x - 1) + >>> gammasimp(gamma(n + 3)) + gamma(n + 3) + + """ + + expr = expr.rewrite(gamma) + + # compute_ST will be looking for Functions and we don't want + # it looking for non-gamma functions: issue 22606 + # so we mask free, non-gamma functions + f = expr.atoms(Function) + # take out gammas + gammas = {i for i in f if isinstance(i, gamma)} + if not gammas: + return expr # avoid side effects like factoring + f -= gammas + # keep only those without bound symbols + f = f & expr.as_dummy().atoms(Function) + if f: + dum, fun, simp = zip(*[ + (Dummy(), fi, fi.func(*[ + _gammasimp(a, as_comb=False) for a in fi.args])) + for fi in ordered(f)]) + d = expr.xreplace(dict(zip(fun, dum))) + return _gammasimp(d, as_comb=False).xreplace(dict(zip(dum, simp))) + + return _gammasimp(expr, as_comb=False) + + +def _gammasimp(expr, as_comb): + """ + Helper function for gammasimp and combsimp. + + Explanation + =========== + + Simplifies expressions written in terms of gamma function. If + as_comb is True, it tries to preserve integer arguments. See + docstring of gammasimp for more information. This was part of + combsimp() in combsimp.py. + """ + expr = expr.replace(gamma, + lambda n: _rf(1, (n - 1).expand())) + + if as_comb: + expr = expr.replace(_rf, + lambda a, b: gamma(b + 1)) + else: + expr = expr.replace(_rf, + lambda a, b: gamma(a + b)/gamma(a)) + + def rule_gamma(expr, level=0): + """ Simplify products of gamma functions further. """ + + if expr.is_Atom: + return expr + + def gamma_rat(x): + # helper to simplify ratios of gammas + was = x.count(gamma) + xx = x.replace(gamma, lambda n: _rf(1, (n - 1).expand() + ).replace(_rf, lambda a, b: gamma(a + b)/gamma(a))) + if xx.count(gamma) < was: + x = xx + return x + + def gamma_factor(x): + # return True if there is a gamma factor in shallow args + if isinstance(x, gamma): + return True + if x.is_Add or x.is_Mul: + return any(gamma_factor(xi) for xi in x.args) + if x.is_Pow and (x.exp.is_integer or x.base.is_positive): + return gamma_factor(x.base) + return False + + # recursion step + if level == 0: + expr = expr.func(*[rule_gamma(x, level + 1) for x in expr.args]) + level += 1 + + if not expr.is_Mul: + return expr + + # non-commutative step + if level == 1: + args, nc = expr.args_cnc() + if not args: + return expr + if nc: + return rule_gamma(Mul._from_args(args), level + 1)*Mul._from_args(nc) + level += 1 + + # pure gamma handling, not factor absorption + if level == 2: + T, F = sift(expr.args, gamma_factor, binary=True) + gamma_ind = Mul(*F) + d = Mul(*T) + + nd, dd = d.as_numer_denom() + for ipass in range(2): + args = list(ordered(Mul.make_args(nd))) + for i, ni in enumerate(args): + if ni.is_Add: + ni, dd = Add(*[ + rule_gamma(gamma_rat(a/dd), level + 1) for a in ni.args] + ).as_numer_denom() + args[i] = ni + if not dd.has(gamma): + break + nd = Mul(*args) + if ipass == 0 and not gamma_factor(nd): + break + nd, dd = dd, nd # now process in reversed order + expr = gamma_ind*nd/dd + if not (expr.is_Mul and (gamma_factor(dd) or gamma_factor(nd))): + return expr + level += 1 + + # iteration until constant + if level == 3: + while True: + was = expr + expr = rule_gamma(expr, 4) + if expr == was: + return expr + + numer_gammas = [] + denom_gammas = [] + numer_others = [] + denom_others = [] + def explicate(p): + if p is S.One: + return None, [] + b, e = p.as_base_exp() + if e.is_Integer: + if isinstance(b, gamma): + return True, [b.args[0]]*e + else: + return False, [b]*e + else: + return False, [p] + + newargs = list(ordered(expr.args)) + while newargs: + n, d = newargs.pop().as_numer_denom() + isg, l = explicate(n) + if isg: + numer_gammas.extend(l) + elif isg is False: + numer_others.extend(l) + isg, l = explicate(d) + if isg: + denom_gammas.extend(l) + elif isg is False: + denom_others.extend(l) + + # =========== level 2 work: pure gamma manipulation ========= + + if not as_comb: + # Try to reduce the number of gamma factors by applying the + # reflection formula gamma(x)*gamma(1-x) = pi/sin(pi*x) + for gammas, numer, denom in [( + numer_gammas, numer_others, denom_others), + (denom_gammas, denom_others, numer_others)]: + new = [] + while gammas: + g1 = gammas.pop() + if g1.is_integer: + new.append(g1) + continue + for i, g2 in enumerate(gammas): + n = g1 + g2 - 1 + if not n.is_Integer: + continue + numer.append(S.Pi) + denom.append(sin(S.Pi*g1)) + gammas.pop(i) + if n > 0: + numer.extend(1 - g1 + k for k in range(n)) + elif n < 0: + denom.extend(-g1 - k for k in range(-n)) + break + else: + new.append(g1) + # /!\ updating IN PLACE + gammas[:] = new + + # Try to reduce the number of gammas by using the duplication + # theorem to cancel an upper and lower: gamma(2*s)/gamma(s) = + # 2**(2*s + 1)/(4*sqrt(pi))*gamma(s + 1/2). Although this could + # be done with higher argument ratios like gamma(3*x)/gamma(x), + # this would not reduce the number of gammas as in this case. + for ng, dg, no, do in [(numer_gammas, denom_gammas, numer_others, + denom_others), + (denom_gammas, numer_gammas, denom_others, + numer_others)]: + + while True: + for x in ng: + for y in dg: + n = x - 2*y + if n.is_Integer: + break + else: + continue + break + else: + break + ng.remove(x) + dg.remove(y) + if n > 0: + no.extend(2*y + k for k in range(n)) + elif n < 0: + do.extend(2*y - 1 - k for k in range(-n)) + ng.append(y + S.Half) + no.append(2**(2*y - 1)) + do.append(sqrt(S.Pi)) + + # Try to reduce the number of gamma factors by applying the + # multiplication theorem (used when n gammas with args differing + # by 1/n mod 1 are encountered). + # + # run of 2 with args differing by 1/2 + # + # >>> gammasimp(gamma(x)*gamma(x+S.Half)) + # 2*sqrt(2)*2**(-2*x - 1/2)*sqrt(pi)*gamma(2*x) + # + # run of 3 args differing by 1/3 (mod 1) + # + # >>> gammasimp(gamma(x)*gamma(x+S(1)/3)*gamma(x+S(2)/3)) + # 6*3**(-3*x - 1/2)*pi*gamma(3*x) + # >>> gammasimp(gamma(x)*gamma(x+S(1)/3)*gamma(x+S(5)/3)) + # 2*3**(-3*x - 1/2)*pi*(3*x + 2)*gamma(3*x) + # + def _run(coeffs): + # find runs in coeffs such that the difference in terms (mod 1) + # of t1, t2, ..., tn is 1/n + u = list(uniq(coeffs)) + for i in range(len(u)): + dj = ([((u[j] - u[i]) % 1, j) for j in range(i + 1, len(u))]) + for one, j in dj: + if one.p == 1 and one.q != 1: + n = one.q + got = [i] + get = list(range(1, n)) + for d, j in dj: + m = n*d + if m.is_Integer and m in get: + get.remove(m) + got.append(j) + if not get: + break + else: + continue + for i, j in enumerate(got): + c = u[j] + coeffs.remove(c) + got[i] = c + return one.q, got[0], got[1:] + + def _mult_thm(gammas, numer, denom): + # pull off and analyze the leading coefficient from each gamma arg + # looking for runs in those Rationals + + # expr -> coeff + resid -> rats[resid] = coeff + rats = {} + for g in gammas: + c, resid = g.as_coeff_Add() + rats.setdefault(resid, []).append(c) + + # look for runs in Rationals for each resid + keys = sorted(rats, key=default_sort_key) + for resid in keys: + coeffs = sorted(rats[resid]) + new = [] + while True: + run = _run(coeffs) + if run is None: + break + + # process the sequence that was found: + # 1) convert all the gamma functions to have the right + # argument (could be off by an integer) + # 2) append the factors corresponding to the theorem + # 3) append the new gamma function + + n, ui, other = run + + # (1) + for u in other: + con = resid + u - 1 + for k in range(int(u - ui)): + numer.append(con - k) + + con = n*(resid + ui) # for (2) and (3) + + # (2) + numer.append((2*S.Pi)**(S(n - 1)/2)* + n**(S.Half - con)) + # (3) + new.append(con) + + # restore resid to coeffs + rats[resid] = [resid + c for c in coeffs] + new + + # rebuild the gamma arguments + g = [] + for resid in keys: + g += rats[resid] + # /!\ updating IN PLACE + gammas[:] = g + + for l, numer, denom in [(numer_gammas, numer_others, denom_others), + (denom_gammas, denom_others, numer_others)]: + _mult_thm(l, numer, denom) + + # =========== level >= 2 work: factor absorption ========= + + if level >= 2: + # Try to absorb factors into the gammas: x*gamma(x) -> gamma(x + 1) + # and gamma(x)/(x - 1) -> gamma(x - 1) + # This code (in particular repeated calls to find_fuzzy) can be very + # slow. + def find_fuzzy(l, x): + if not l: + return + S1, T1 = compute_ST(x) + for y in l: + S2, T2 = inv[y] + if T1 != T2 or (not S1.intersection(S2) and + (S1 != set() or S2 != set())): + continue + # XXX we want some simplification (e.g. cancel or + # simplify) but no matter what it's slow. + a = len(cancel(x/y).free_symbols) + b = len(x.free_symbols) + c = len(y.free_symbols) + # TODO is there a better heuristic? + if a == 0 and (b > 0 or c > 0): + return y + + # We thus try to avoid expensive calls by building the following + # "invariants": For every factor or gamma function argument + # - the set of free symbols S + # - the set of functional components T + # We will only try to absorb if T1==T2 and (S1 intersect S2 != emptyset + # or S1 == S2 == emptyset) + inv = {} + + def compute_ST(expr): + if expr in inv: + return inv[expr] + return (expr.free_symbols, expr.atoms(Function).union( + {e.exp for e in expr.atoms(Pow)})) + + def update_ST(expr): + inv[expr] = compute_ST(expr) + for expr in numer_gammas + denom_gammas + numer_others + denom_others: + update_ST(expr) + + for gammas, numer, denom in [( + numer_gammas, numer_others, denom_others), + (denom_gammas, denom_others, numer_others)]: + new = [] + while gammas: + g = gammas.pop() + cont = True + while cont: + cont = False + y = find_fuzzy(numer, g) + if y is not None: + numer.remove(y) + if y != g: + numer.append(y/g) + update_ST(y/g) + g += 1 + cont = True + y = find_fuzzy(denom, g - 1) + if y is not None: + denom.remove(y) + if y != g - 1: + numer.append((g - 1)/y) + update_ST((g - 1)/y) + g -= 1 + cont = True + new.append(g) + # /!\ updating IN PLACE + gammas[:] = new + + # =========== rebuild expr ================================== + + return Mul(*[gamma(g) for g in numer_gammas]) \ + / Mul(*[gamma(g) for g in denom_gammas]) \ + * Mul(*numer_others) / Mul(*denom_others) + + was = factor(expr) + # (for some reason we cannot use Basic.replace in this case) + expr = rule_gamma(was) + if expr != was: + expr = factor(expr) + + expr = expr.replace(gamma, + lambda n: expand_func(gamma(n)) if n.is_Rational else gamma(n)) + + return expr + + +class _rf(Function): + @classmethod + def eval(cls, a, b): + if b.is_Integer: + if not b: + return S.One + + n = int(b) + + if n > 0: + return Mul(*[a + i for i in range(n)]) + elif n < 0: + return 1/Mul(*[a - i for i in range(1, -n + 1)]) + else: + if b.is_Add: + c, _b = b.as_coeff_Add() + + if c.is_Integer: + if c > 0: + return _rf(a, _b)*_rf(a + _b, c) + elif c < 0: + return _rf(a, _b)/_rf(a + _b + c, -c) + + if a.is_Add: + c, _a = a.as_coeff_Add() + + if c.is_Integer: + if c > 0: + return _rf(_a, b)*_rf(_a + b, c)/_rf(_a, c) + elif c < 0: + return _rf(_a, b)*_rf(_a + c, -c)/_rf(_a + b + c, -c) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/hyperexpand.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/hyperexpand.py new file mode 100644 index 0000000000000000000000000000000000000000..c070aa2e44b92794107b3e33df897813a54307b9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/hyperexpand.py @@ -0,0 +1,2494 @@ +""" +Expand Hypergeometric (and Meijer G) functions into named +special functions. + +The algorithm for doing this uses a collection of lookup tables of +hypergeometric functions, and various of their properties, to expand +many hypergeometric functions in terms of special functions. + +It is based on the following paper: + Kelly B. Roach. Meijer G Function Representations. + In: Proceedings of the 1997 International Symposium on Symbolic and + Algebraic Computation, pages 205-211, New York, 1997. ACM. + +It is described in great(er) detail in the Sphinx documentation. +""" +# SUMMARY OF EXTENSIONS FOR MEIJER G FUNCTIONS +# +# o z**rho G(ap, bq; z) = G(ap + rho, bq + rho; z) +# +# o denote z*d/dz by D +# +# o It is helpful to keep in mind that ap and bq play essentially symmetric +# roles: G(1/z) has slightly altered parameters, with ap and bq interchanged. +# +# o There are four shift operators: +# A_J = b_J - D, J = 1, ..., n +# B_J = 1 - a_j + D, J = 1, ..., m +# C_J = -b_J + D, J = m+1, ..., q +# D_J = a_J - 1 - D, J = n+1, ..., p +# +# A_J, C_J increment b_J +# B_J, D_J decrement a_J +# +# o The corresponding four inverse-shift operators are defined if there +# is no cancellation. Thus e.g. an index a_J (upper or lower) can be +# incremented if a_J != b_i for i = 1, ..., q. +# +# o Order reduction: if b_j - a_i is a non-negative integer, where +# j <= m and i > n, the corresponding quotient of gamma functions reduces +# to a polynomial. Hence the G function can be expressed using a G-function +# of lower order. +# Similarly if j > m and i <= n. +# +# Secondly, there are paired index theorems [Adamchik, The evaluation of +# integrals of Bessel functions via G-function identities]. Suppose there +# are three parameters a, b, c, where a is an a_i, i <= n, b is a b_j, +# j <= m and c is a denominator parameter (i.e. a_i, i > n or b_j, j > m). +# Suppose further all three differ by integers. +# Then the order can be reduced. +# TODO work this out in detail. +# +# o An index quadruple is called suitable if its order cannot be reduced. +# If there exists a sequence of shift operators transforming one index +# quadruple into another, we say one is reachable from the other. +# +# o Deciding if one index quadruple is reachable from another is tricky. For +# this reason, we use hand-built routines to match and instantiate formulas. +# +from collections import defaultdict +from itertools import product +from functools import reduce +from math import prod + +from sympy import SYMPY_DEBUG +from sympy.core import (S, Dummy, symbols, sympify, Tuple, expand, I, pi, Mul, + EulerGamma, oo, zoo, expand_func, Add, nan, Expr, Rational) +from sympy.core.mod import Mod +from sympy.core.sorting import default_sort_key +from sympy.functions import (exp, sqrt, root, log, lowergamma, cos, + besseli, gamma, uppergamma, expint, erf, sin, besselj, Ei, Ci, Si, Shi, + sinh, cosh, Chi, fresnels, fresnelc, polar_lift, exp_polar, floor, ceiling, + rf, factorial, lerchphi, Piecewise, re, elliptic_k, elliptic_e) +from sympy.functions.elementary.complexes import polarify, unpolarify +from sympy.functions.special.hyper import (hyper, HyperRep_atanh, + HyperRep_power1, HyperRep_power2, HyperRep_log1, HyperRep_asin1, + HyperRep_asin2, HyperRep_sqrts1, HyperRep_sqrts2, HyperRep_log2, + HyperRep_cosasin, HyperRep_sinasin, meijerg) +from sympy.matrices import Matrix, eye, zeros +from sympy.polys import apart, poly, Poly +from sympy.series import residue +from sympy.simplify.powsimp import powdenest +from sympy.utilities.iterables import sift + +# function to define "buckets" +def _mod1(x): + # TODO see if this can work as Mod(x, 1); this will require + # different handling of the "buckets" since these need to + # be sorted and that fails when there is a mixture of + # integers and expressions with parameters. With the current + # Mod behavior, Mod(k, 1) == Mod(1, 1) == 0 if k is an integer. + # Although the sorting can be done with Basic.compare, this may + # still require different handling of the sorted buckets. + if x.is_Number: + return Mod(x, 1) + c, x = x.as_coeff_Add() + return Mod(c, 1) + x + + +# leave add formulae at the top for easy reference +def add_formulae(formulae): + """ Create our knowledge base. """ + a, b, c, z = symbols('a b c, z', cls=Dummy) + + def add(ap, bq, res): + func = Hyper_Function(ap, bq) + formulae.append(Formula(func, z, res, (a, b, c))) + + def addb(ap, bq, B, C, M): + func = Hyper_Function(ap, bq) + formulae.append(Formula(func, z, None, (a, b, c), B, C, M)) + + # Luke, Y. L. (1969), The Special Functions and Their Approximations, + # Volume 1, section 6.2 + + # 0F0 + add((), (), exp(z)) + + # 1F0 + add((a, ), (), HyperRep_power1(-a, z)) + + # 2F1 + addb((a, a - S.Half), (2*a, ), + Matrix([HyperRep_power2(a, z), + HyperRep_power2(a + S.Half, z)/2]), + Matrix([[1, 0]]), + Matrix([[(a - S.Half)*z/(1 - z), (S.Half - a)*z/(1 - z)], + [a/(1 - z), a*(z - 2)/(1 - z)]])) + addb((1, 1), (2, ), + Matrix([HyperRep_log1(z), 1]), Matrix([[-1/z, 0]]), + Matrix([[0, z/(z - 1)], [0, 0]])) + addb((S.Half, 1), (S('3/2'), ), + Matrix([HyperRep_atanh(z), 1]), + Matrix([[1, 0]]), + Matrix([[Rational(-1, 2), 1/(1 - z)/2], [0, 0]])) + addb((S.Half, S.Half), (S('3/2'), ), + Matrix([HyperRep_asin1(z), HyperRep_power1(Rational(-1, 2), z)]), + Matrix([[1, 0]]), + Matrix([[Rational(-1, 2), S.Half], [0, z/(1 - z)/2]])) + addb((a, S.Half + a), (S.Half, ), + Matrix([HyperRep_sqrts1(-a, z), -HyperRep_sqrts2(-a - S.Half, z)]), + Matrix([[1, 0]]), + Matrix([[0, -a], + [z*(-2*a - 1)/2/(1 - z), S.Half - z*(-2*a - 1)/(1 - z)]])) + + # A. P. Prudnikov, Yu. A. Brychkov and O. I. Marichev (1990). + # Integrals and Series: More Special Functions, Vol. 3,. + # Gordon and Breach Science Publisher + addb([a, -a], [S.Half], + Matrix([HyperRep_cosasin(a, z), HyperRep_sinasin(a, z)]), + Matrix([[1, 0]]), + Matrix([[0, -a], [a*z/(1 - z), 1/(1 - z)/2]])) + addb([1, 1], [3*S.Half], + Matrix([HyperRep_asin2(z), 1]), Matrix([[1, 0]]), + Matrix([[(z - S.Half)/(1 - z), 1/(1 - z)/2], [0, 0]])) + + # Complete elliptic integrals K(z) and E(z), both a 2F1 function + addb([S.Half, S.Half], [S.One], + Matrix([elliptic_k(z), elliptic_e(z)]), + Matrix([[2/pi, 0]]), + Matrix([[Rational(-1, 2), -1/(2*z-2)], + [Rational(-1, 2), S.Half]])) + addb([Rational(-1, 2), S.Half], [S.One], + Matrix([elliptic_k(z), elliptic_e(z)]), + Matrix([[0, 2/pi]]), + Matrix([[Rational(-1, 2), -1/(2*z-2)], + [Rational(-1, 2), S.Half]])) + + # 3F2 + addb([Rational(-1, 2), 1, 1], [S.Half, 2], + Matrix([z*HyperRep_atanh(z), HyperRep_log1(z), 1]), + Matrix([[Rational(-2, 3), -S.One/(3*z), Rational(2, 3)]]), + Matrix([[S.Half, 0, z/(1 - z)/2], + [0, 0, z/(z - 1)], + [0, 0, 0]])) + # actually the formula for 3/2 is much nicer ... + addb([Rational(-1, 2), 1, 1], [2, 2], + Matrix([HyperRep_power1(S.Half, z), HyperRep_log2(z), 1]), + Matrix([[Rational(4, 9) - 16/(9*z), 4/(3*z), 16/(9*z)]]), + Matrix([[z/2/(z - 1), 0, 0], [1/(2*(z - 1)), 0, S.Half], [0, 0, 0]])) + + # 1F1 + addb([1], [b], Matrix([z**(1 - b) * exp(z) * lowergamma(b - 1, z), 1]), + Matrix([[b - 1, 0]]), Matrix([[1 - b + z, 1], [0, 0]])) + addb([a], [2*a], + Matrix([z**(S.Half - a)*exp(z/2)*besseli(a - S.Half, z/2) + * gamma(a + S.Half)/4**(S.Half - a), + z**(S.Half - a)*exp(z/2)*besseli(a + S.Half, z/2) + * gamma(a + S.Half)/4**(S.Half - a)]), + Matrix([[1, 0]]), + Matrix([[z/2, z/2], [z/2, (z/2 - 2*a)]])) + mz = polar_lift(-1)*z + addb([a], [a + 1], + Matrix([mz**(-a)*a*lowergamma(a, mz), a*exp(z)]), + Matrix([[1, 0]]), + Matrix([[-a, 1], [0, z]])) + # This one is redundant. + add([Rational(-1, 2)], [S.Half], exp(z) - sqrt(pi*z)*(-I)*erf(I*sqrt(z))) + + # Added to get nice results for Laplace transform of Fresnel functions + # https://functions.wolfram.com/07.22.03.6437.01 + # Basic rule + #add([1], [Rational(3, 4), Rational(5, 4)], + # sqrt(pi) * (cos(2*sqrt(polar_lift(-1)*z))*fresnelc(2*root(polar_lift(-1)*z,4)/sqrt(pi)) + + # sin(2*sqrt(polar_lift(-1)*z))*fresnels(2*root(polar_lift(-1)*z,4)/sqrt(pi))) + # / (2*root(polar_lift(-1)*z,4))) + # Manually tuned rule + addb([1], [Rational(3, 4), Rational(5, 4)], + Matrix([ sqrt(pi)*(I*sinh(2*sqrt(z))*fresnels(2*root(z, 4)*exp(I*pi/4)/sqrt(pi)) + + cosh(2*sqrt(z))*fresnelc(2*root(z, 4)*exp(I*pi/4)/sqrt(pi))) + * exp(-I*pi/4)/(2*root(z, 4)), + sqrt(pi)*root(z, 4)*(sinh(2*sqrt(z))*fresnelc(2*root(z, 4)*exp(I*pi/4)/sqrt(pi)) + + I*cosh(2*sqrt(z))*fresnels(2*root(z, 4)*exp(I*pi/4)/sqrt(pi))) + *exp(-I*pi/4)/2, + 1 ]), + Matrix([[1, 0, 0]]), + Matrix([[Rational(-1, 4), 1, Rational(1, 4)], + [ z, Rational(1, 4), 0], + [ 0, 0, 0]])) + + # 2F2 + addb([S.Half, a], [Rational(3, 2), a + 1], + Matrix([a/(2*a - 1)*(-I)*sqrt(pi/z)*erf(I*sqrt(z)), + a/(2*a - 1)*(polar_lift(-1)*z)**(-a)* + lowergamma(a, polar_lift(-1)*z), + a/(2*a - 1)*exp(z)]), + Matrix([[1, -1, 0]]), + Matrix([[Rational(-1, 2), 0, 1], [0, -a, 1], [0, 0, z]])) + # We make a "basis" of four functions instead of three, and give EulerGamma + # an extra slot (it could just be a coefficient to 1). The advantage is + # that this way Polys will not see multivariate polynomials (it treats + # EulerGamma as an indeterminate), which is *way* faster. + addb([1, 1], [2, 2], + Matrix([Ei(z) - log(z), exp(z), 1, EulerGamma]), + Matrix([[1/z, 0, 0, -1/z]]), + Matrix([[0, 1, -1, 0], [0, z, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]])) + + # 0F1 + add((), (S.Half, ), cosh(2*sqrt(z))) + addb([], [b], + Matrix([gamma(b)*z**((1 - b)/2)*besseli(b - 1, 2*sqrt(z)), + gamma(b)*z**(1 - b/2)*besseli(b, 2*sqrt(z))]), + Matrix([[1, 0]]), Matrix([[0, 1], [z, (1 - b)]])) + + # 0F3 + x = 4*z**Rational(1, 4) + + def fp(a, z): + return besseli(a, x) + besselj(a, x) + + def fm(a, z): + return besseli(a, x) - besselj(a, x) + + # TODO branching + addb([], [S.Half, a, a + S.Half], + Matrix([fp(2*a - 1, z), fm(2*a, z)*z**Rational(1, 4), + fm(2*a - 1, z)*sqrt(z), fp(2*a, z)*z**Rational(3, 4)]) + * 2**(-2*a)*gamma(2*a)*z**((1 - 2*a)/4), + Matrix([[1, 0, 0, 0]]), + Matrix([[0, 1, 0, 0], + [0, S.Half - a, 1, 0], + [0, 0, S.Half, 1], + [z, 0, 0, 1 - a]])) + x = 2*(4*z)**Rational(1, 4)*exp_polar(I*pi/4) + addb([], [a, a + S.Half, 2*a], + (2*sqrt(polar_lift(-1)*z))**(1 - 2*a)*gamma(2*a)**2 * + Matrix([besselj(2*a - 1, x)*besseli(2*a - 1, x), + x*(besseli(2*a, x)*besselj(2*a - 1, x) + - besseli(2*a - 1, x)*besselj(2*a, x)), + x**2*besseli(2*a, x)*besselj(2*a, x), + x**3*(besseli(2*a, x)*besselj(2*a - 1, x) + + besseli(2*a - 1, x)*besselj(2*a, x))]), + Matrix([[1, 0, 0, 0]]), + Matrix([[0, Rational(1, 4), 0, 0], + [0, (1 - 2*a)/2, Rational(-1, 2), 0], + [0, 0, 1 - 2*a, Rational(1, 4)], + [-32*z, 0, 0, 1 - a]])) + + # 1F2 + addb([a], [a - S.Half, 2*a], + Matrix([z**(S.Half - a)*besseli(a - S.Half, sqrt(z))**2, + z**(1 - a)*besseli(a - S.Half, sqrt(z)) + *besseli(a - Rational(3, 2), sqrt(z)), + z**(Rational(3, 2) - a)*besseli(a - Rational(3, 2), sqrt(z))**2]), + Matrix([[-gamma(a + S.Half)**2/4**(S.Half - a), + 2*gamma(a - S.Half)*gamma(a + S.Half)/4**(1 - a), + 0]]), + Matrix([[1 - 2*a, 1, 0], [z/2, S.Half - a, S.Half], [0, z, 0]])) + addb([S.Half], [b, 2 - b], + pi*(1 - b)/sin(pi*b)* + Matrix([besseli(1 - b, sqrt(z))*besseli(b - 1, sqrt(z)), + sqrt(z)*(besseli(-b, sqrt(z))*besseli(b - 1, sqrt(z)) + + besseli(1 - b, sqrt(z))*besseli(b, sqrt(z))), + besseli(-b, sqrt(z))*besseli(b, sqrt(z))]), + Matrix([[1, 0, 0]]), + Matrix([[b - 1, S.Half, 0], + [z, 0, z], + [0, S.Half, -b]])) + addb([S.Half], [Rational(3, 2), Rational(3, 2)], + Matrix([Shi(2*sqrt(z))/2/sqrt(z), sinh(2*sqrt(z))/2/sqrt(z), + cosh(2*sqrt(z))]), + Matrix([[1, 0, 0]]), + Matrix([[Rational(-1, 2), S.Half, 0], [0, Rational(-1, 2), S.Half], [0, 2*z, 0]])) + + # FresnelS + # Basic rule + #add([Rational(3, 4)], [Rational(3, 2),Rational(7, 4)], 6*fresnels( exp(pi*I/4)*root(z,4)*2/sqrt(pi) ) / ( pi * (exp(pi*I/4)*root(z,4)*2/sqrt(pi))**3 ) ) + # Manually tuned rule + addb([Rational(3, 4)], [Rational(3, 2), Rational(7, 4)], + Matrix( + [ fresnels( + exp( + pi*I/4)*root( + z, 4)*2/sqrt( + pi) ) / ( + pi * (exp(pi*I/4)*root(z, 4)*2/sqrt(pi))**3 ), + sinh(2*sqrt(z))/sqrt(z), + cosh(2*sqrt(z)) ]), + Matrix([[6, 0, 0]]), + Matrix([[Rational(-3, 4), Rational(1, 16), 0], + [ 0, Rational(-1, 2), 1], + [ 0, z, 0]])) + + # FresnelC + # Basic rule + #add([Rational(1, 4)], [S.Half,Rational(5, 4)], fresnelc( exp(pi*I/4)*root(z,4)*2/sqrt(pi) ) / ( exp(pi*I/4)*root(z,4)*2/sqrt(pi) ) ) + # Manually tuned rule + addb([Rational(1, 4)], [S.Half, Rational(5, 4)], + Matrix( + [ sqrt( + pi)*exp( + -I*pi/4)*fresnelc( + 2*root(z, 4)*exp(I*pi/4)/sqrt(pi))/(2*root(z, 4)), + cosh(2*sqrt(z)), + sinh(2*sqrt(z))*sqrt(z) ]), + Matrix([[1, 0, 0]]), + Matrix([[Rational(-1, 4), Rational(1, 4), 0 ], + [ 0, 0, 1 ], + [ 0, z, S.Half]])) + + # 2F3 + # XXX with this five-parameter formula is pretty slow with the current + # Formula.find_instantiations (creates 2!*3!*3**(2+3) ~ 3000 + # instantiations ... But it's not too bad. + addb([a, a + S.Half], [2*a, b, 2*a - b + 1], + gamma(b)*gamma(2*a - b + 1) * (sqrt(z)/2)**(1 - 2*a) * + Matrix([besseli(b - 1, sqrt(z))*besseli(2*a - b, sqrt(z)), + sqrt(z)*besseli(b, sqrt(z))*besseli(2*a - b, sqrt(z)), + sqrt(z)*besseli(b - 1, sqrt(z))*besseli(2*a - b + 1, sqrt(z)), + besseli(b, sqrt(z))*besseli(2*a - b + 1, sqrt(z))]), + Matrix([[1, 0, 0, 0]]), + Matrix([[0, S.Half, S.Half, 0], + [z/2, 1 - b, 0, z/2], + [z/2, 0, b - 2*a, z/2], + [0, S.Half, S.Half, -2*a]])) + # (C/f above comment about eulergamma in the basis). + addb([1, 1], [2, 2, Rational(3, 2)], + Matrix([Chi(2*sqrt(z)) - log(2*sqrt(z)), + cosh(2*sqrt(z)), sqrt(z)*sinh(2*sqrt(z)), 1, EulerGamma]), + Matrix([[1/z, 0, 0, 0, -1/z]]), + Matrix([[0, S.Half, 0, Rational(-1, 2), 0], + [0, 0, 1, 0, 0], + [0, z, S.Half, 0, 0], + [0, 0, 0, 0, 0], + [0, 0, 0, 0, 0]])) + + # 3F3 + # This is rule: https://functions.wolfram.com/07.31.03.0134.01 + # Initial reason to add it was a nice solution for + # integrate(erf(a*z)/z**2, z) and same for erfc and erfi. + # Basic rule + # add([1, 1, a], [2, 2, a+1], (a/(z*(a-1)**2)) * + # (1 - (-z)**(1-a) * (gamma(a) - uppergamma(a,-z)) + # - (a-1) * (EulerGamma + uppergamma(0,-z) + log(-z)) + # - exp(z))) + # Manually tuned rule + addb([1, 1, a], [2, 2, a+1], + Matrix([a*(log(-z) + expint(1, -z) + EulerGamma)/(z*(a**2 - 2*a + 1)), + a*(-z)**(-a)*(gamma(a) - uppergamma(a, -z))/(a - 1)**2, + a*exp(z)/(a**2 - 2*a + 1), + a/(z*(a**2 - 2*a + 1))]), + Matrix([[1-a, 1, -1/z, 1]]), + Matrix([[-1,0,-1/z,1], + [0,-a,1,0], + [0,0,z,0], + [0,0,0,-1]])) + + +def add_meijerg_formulae(formulae): + a, b, c, z = list(map(Dummy, 'abcz')) + rho = Dummy('rho') + + def add(an, ap, bm, bq, B, C, M, matcher): + formulae.append(MeijerFormula(an, ap, bm, bq, z, [a, b, c, rho], + B, C, M, matcher)) + + def detect_uppergamma(func): + x = func.an[0] + y, z = func.bm + swapped = False + if not _mod1((x - y).simplify()): + swapped = True + (y, z) = (z, y) + if _mod1((x - z).simplify()) or x - z > 0: + return None + l = [y, x] + if swapped: + l = [x, y] + return {rho: y, a: x - y}, G_Function([x], [], l, []) + + add([a + rho], [], [rho, a + rho], [], + Matrix([gamma(1 - a)*z**rho*exp(z)*uppergamma(a, z), + gamma(1 - a)*z**(a + rho)]), + Matrix([[1, 0]]), + Matrix([[rho + z, -1], [0, a + rho]]), + detect_uppergamma) + + def detect_3113(func): + """https://functions.wolfram.com/07.34.03.0984.01""" + x = func.an[0] + u, v, w = func.bm + if _mod1((u - v).simplify()) == 0: + if _mod1((v - w).simplify()) == 0: + return + sig = (S.Half, S.Half, S.Zero) + x1, x2, y = u, v, w + else: + if _mod1((x - u).simplify()) == 0: + sig = (S.Half, S.Zero, S.Half) + x1, y, x2 = u, v, w + else: + sig = (S.Zero, S.Half, S.Half) + y, x1, x2 = u, v, w + + if (_mod1((x - x1).simplify()) != 0 or + _mod1((x - x2).simplify()) != 0 or + _mod1((x - y).simplify()) != S.Half or + x - x1 > 0 or x - x2 > 0): + return + + return {a: x}, G_Function([x], [], [x - S.Half + t for t in sig], []) + + s = sin(2*sqrt(z)) + c_ = cos(2*sqrt(z)) + S_ = Si(2*sqrt(z)) - pi/2 + C = Ci(2*sqrt(z)) + add([a], [], [a, a, a - S.Half], [], + Matrix([sqrt(pi)*z**(a - S.Half)*(c_*S_ - s*C), + sqrt(pi)*z**a*(s*S_ + c_*C), + sqrt(pi)*z**a]), + Matrix([[-2, 0, 0]]), + Matrix([[a - S.Half, -1, 0], [z, a, S.Half], [0, 0, a]]), + detect_3113) + + +def make_simp(z): + """ Create a function that simplifies rational functions in ``z``. """ + + def simp(expr): + """ Efficiently simplify the rational function ``expr``. """ + numer, denom = expr.as_numer_denom() + numer = numer.expand() + # denom = denom.expand() # is this needed? + c, numer, denom = poly(numer, z).cancel(poly(denom, z)) + return c * numer.as_expr() / denom.as_expr() + + return simp + + +def debug(*args): + if SYMPY_DEBUG: + for a in args: + print(a, end="") + print() + + +class Hyper_Function(Expr): + """ A generalized hypergeometric function. """ + + def __new__(cls, ap, bq): + obj = super().__new__(cls) + obj.ap = Tuple(*list(map(expand, ap))) + obj.bq = Tuple(*list(map(expand, bq))) + return obj + + @property + def args(self): + return (self.ap, self.bq) + + @property + def sizes(self): + return (len(self.ap), len(self.bq)) + + @property + def gamma(self): + """ + Number of upper parameters that are negative integers + + This is a transformation invariant. + """ + return sum(bool(x.is_integer and x.is_negative) for x in self.ap) + + def _hashable_content(self): + return super()._hashable_content() + (self.ap, + self.bq) + + def __call__(self, arg): + return hyper(self.ap, self.bq, arg) + + def build_invariants(self): + """ + Compute the invariant vector. + + Explanation + =========== + + The invariant vector is: + (gamma, ((s1, n1), ..., (sk, nk)), ((t1, m1), ..., (tr, mr))) + where gamma is the number of integer a < 0, + s1 < ... < sk + nl is the number of parameters a_i congruent to sl mod 1 + t1 < ... < tr + ml is the number of parameters b_i congruent to tl mod 1 + + If the index pair contains parameters, then this is not truly an + invariant, since the parameters cannot be sorted uniquely mod1. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import Hyper_Function + >>> from sympy import S + >>> ap = (S.Half, S.One/3, S(-1)/2, -2) + >>> bq = (1, 2) + + Here gamma = 1, + k = 3, s1 = 0, s2 = 1/3, s3 = 1/2 + n1 = 1, n2 = 1, n2 = 2 + r = 1, t1 = 0 + m1 = 2: + + >>> Hyper_Function(ap, bq).build_invariants() + (1, ((0, 1), (1/3, 1), (1/2, 2)), ((0, 2),)) + """ + abuckets, bbuckets = sift(self.ap, _mod1), sift(self.bq, _mod1) + + def tr(bucket): + bucket = list(bucket.items()) + if not any(isinstance(x[0], Mod) for x in bucket): + bucket.sort(key=lambda x: default_sort_key(x[0])) + bucket = tuple([(mod, len(values)) for mod, values in bucket if + values]) + return bucket + + return (self.gamma, tr(abuckets), tr(bbuckets)) + + def difficulty(self, func): + """ Estimate how many steps it takes to reach ``func`` from self. + Return -1 if impossible. """ + if self.gamma != func.gamma: + return -1 + oabuckets, obbuckets, abuckets, bbuckets = [sift(params, _mod1) for + params in (self.ap, self.bq, func.ap, func.bq)] + + diff = 0 + for bucket, obucket in [(abuckets, oabuckets), (bbuckets, obbuckets)]: + for mod in set(list(bucket.keys()) + list(obucket.keys())): + if (mod not in bucket) or (mod not in obucket) \ + or len(bucket[mod]) != len(obucket[mod]): + return -1 + l1 = list(bucket[mod]) + l2 = list(obucket[mod]) + l1.sort() + l2.sort() + for i, j in zip(l1, l2): + diff += abs(i - j) + + return diff + + def _is_suitable_origin(self): + """ + Decide if ``self`` is a suitable origin. + + Explanation + =========== + + A function is a suitable origin iff: + * none of the ai equals bj + n, with n a non-negative integer + * none of the ai is zero + * none of the bj is a non-positive integer + + Note that this gives meaningful results only when none of the indices + are symbolic. + + """ + for a in self.ap: + for b in self.bq: + if (a - b).is_integer and (a - b).is_negative is False: + return False + for a in self.ap: + if a == 0: + return False + for b in self.bq: + if b.is_integer and b.is_nonpositive: + return False + return True + + +class G_Function(Expr): + """ A Meijer G-function. """ + + def __new__(cls, an, ap, bm, bq): + obj = super().__new__(cls) + obj.an = Tuple(*list(map(expand, an))) + obj.ap = Tuple(*list(map(expand, ap))) + obj.bm = Tuple(*list(map(expand, bm))) + obj.bq = Tuple(*list(map(expand, bq))) + return obj + + @property + def args(self): + return (self.an, self.ap, self.bm, self.bq) + + def _hashable_content(self): + return super()._hashable_content() + self.args + + def __call__(self, z): + return meijerg(self.an, self.ap, self.bm, self.bq, z) + + def compute_buckets(self): + """ + Compute buckets for the fours sets of parameters. + + Explanation + =========== + + We guarantee that any two equal Mod objects returned are actually the + same, and that the buckets are sorted by real part (an and bq + descendending, bm and ap ascending). + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import G_Function + >>> from sympy.abc import y + >>> from sympy import S + + >>> a, b = [1, 3, 2, S(3)/2], [1 + y, y, 2, y + 3] + >>> G_Function(a, b, [2], [y]).compute_buckets() + ({0: [3, 2, 1], 1/2: [3/2]}, + {0: [2], y: [y, y + 1, y + 3]}, {0: [2]}, {y: [y]}) + + """ + dicts = pan, pap, pbm, pbq = [defaultdict(list) for i in range(4)] + for dic, lis in zip(dicts, (self.an, self.ap, self.bm, self.bq)): + for x in lis: + dic[_mod1(x)].append(x) + + for dic, flip in zip(dicts, (True, False, False, True)): + for m, items in dic.items(): + x0 = items[0] + items.sort(key=lambda x: x - x0, reverse=flip) + dic[m] = items + + return tuple([dict(w) for w in dicts]) + + @property + def signature(self): + return (len(self.an), len(self.ap), len(self.bm), len(self.bq)) + + +# Dummy variable. +_x = Dummy('x') + +class Formula: + """ + This class represents hypergeometric formulae. + + Explanation + =========== + + Its data members are: + - z, the argument + - closed_form, the closed form expression + - symbols, the free symbols (parameters) in the formula + - func, the function + - B, C, M (see _compute_basis) + + Examples + ======== + + >>> from sympy.abc import a, b, z + >>> from sympy.simplify.hyperexpand import Formula, Hyper_Function + >>> func = Hyper_Function((a/2, a/3 + b, (1+a)/2), (a, b, (a+b)/7)) + >>> f = Formula(func, z, None, [a, b]) + + """ + + def _compute_basis(self, closed_form): + """ + Compute a set of functions B=(f1, ..., fn), a nxn matrix M + and a 1xn matrix C such that: + closed_form = C B + z d/dz B = M B. + """ + afactors = [_x + a for a in self.func.ap] + bfactors = [_x + b - 1 for b in self.func.bq] + expr = _x*Mul(*bfactors) - self.z*Mul(*afactors) + poly = Poly(expr, _x) + + n = poly.degree() - 1 + b = [closed_form] + for _ in range(n): + b.append(self.z*b[-1].diff(self.z)) + + self.B = Matrix(b) + self.C = Matrix([[1] + [0]*n]) + + m = eye(n) + m = m.col_insert(0, zeros(n, 1)) + l = poly.all_coeffs()[1:] + l.reverse() + self.M = m.row_insert(n, -Matrix([l])/poly.all_coeffs()[0]) + + def __init__(self, func, z, res, symbols, B=None, C=None, M=None): + z = sympify(z) + res = sympify(res) + symbols = [x for x in sympify(symbols) if func.has(x)] + + self.z = z + self.symbols = symbols + self.B = B + self.C = C + self.M = M + self.func = func + + # TODO with symbolic parameters, it could be advantageous + # (for prettier answers) to compute a basis only *after* + # instantiation + if res is not None: + self._compute_basis(res) + + @property + def closed_form(self): + return reduce(lambda s,m: s+m[0]*m[1], zip(self.C, self.B), S.Zero) + + def find_instantiations(self, func): + """ + Find substitutions of the free symbols that match ``func``. + + Return the substitution dictionaries as a list. Note that the returned + instantiations need not actually match, or be valid! + + """ + from sympy.solvers import solve + ap = func.ap + bq = func.bq + if len(ap) != len(self.func.ap) or len(bq) != len(self.func.bq): + raise TypeError('Cannot instantiate other number of parameters') + symbol_values = [] + for a in self.symbols: + if a in self.func.ap.args: + symbol_values.append(ap) + elif a in self.func.bq.args: + symbol_values.append(bq) + else: + raise ValueError("At least one of the parameters of the " + "formula must be equal to %s" % (a,)) + base_repl = [dict(list(zip(self.symbols, values))) + for values in product(*symbol_values)] + abuckets, bbuckets = [sift(params, _mod1) for params in [ap, bq]] + a_inv, b_inv = [{a: len(vals) for a, vals in bucket.items()} + for bucket in [abuckets, bbuckets]] + critical_values = [[0] for _ in self.symbols] + result = [] + _n = Dummy() + for repl in base_repl: + symb_a, symb_b = [sift(params, lambda x: _mod1(x.xreplace(repl))) + for params in [self.func.ap, self.func.bq]] + for bucket, obucket in [(abuckets, symb_a), (bbuckets, symb_b)]: + for mod in set(list(bucket.keys()) + list(obucket.keys())): + if (mod not in bucket) or (mod not in obucket) \ + or len(bucket[mod]) != len(obucket[mod]): + break + for a, vals in zip(self.symbols, critical_values): + if repl[a].free_symbols: + continue + exprs = [expr for expr in obucket[mod] if expr.has(a)] + repl0 = repl.copy() + repl0[a] += _n + for expr in exprs: + for target in bucket[mod]: + n0, = solve(expr.xreplace(repl0) - target, _n) + if n0.free_symbols: + raise ValueError("Value should not be true") + vals.append(n0) + else: + values = [] + for a, vals in zip(self.symbols, critical_values): + a0 = repl[a] + min_ = floor(min(vals)) + max_ = ceiling(max(vals)) + values.append([a0 + n for n in range(min_, max_ + 1)]) + result.extend(dict(list(zip(self.symbols, l))) for l in product(*values)) + return result + + + + +class FormulaCollection: + """ A collection of formulae to use as origins. """ + + def __init__(self): + """ Doing this globally at module init time is a pain ... """ + self.symbolic_formulae = {} + self.concrete_formulae = {} + self.formulae = [] + + add_formulae(self.formulae) + + # Now process the formulae into a helpful form. + # These dicts are indexed by (p, q). + + for f in self.formulae: + sizes = f.func.sizes + if len(f.symbols) > 0: + self.symbolic_formulae.setdefault(sizes, []).append(f) + else: + inv = f.func.build_invariants() + self.concrete_formulae.setdefault(sizes, {})[inv] = f + + def lookup_origin(self, func): + """ + Given the suitable target ``func``, try to find an origin in our + knowledge base. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import (FormulaCollection, + ... Hyper_Function) + >>> f = FormulaCollection() + >>> f.lookup_origin(Hyper_Function((), ())).closed_form + exp(_z) + >>> f.lookup_origin(Hyper_Function([1], ())).closed_form + HyperRep_power1(-1, _z) + + >>> from sympy import S + >>> i = Hyper_Function([S('1/4'), S('3/4 + 4')], [S.Half]) + >>> f.lookup_origin(i).closed_form + HyperRep_sqrts1(-1/4, _z) + """ + inv = func.build_invariants() + sizes = func.sizes + if sizes in self.concrete_formulae and \ + inv in self.concrete_formulae[sizes]: + return self.concrete_formulae[sizes][inv] + + # We don't have a concrete formula. Try to instantiate. + if sizes not in self.symbolic_formulae: + return None # Too bad... + + possible = [] + for f in self.symbolic_formulae[sizes]: + repls = f.find_instantiations(func) + for repl in repls: + func2 = f.func.xreplace(repl) + if not func2._is_suitable_origin(): + continue + diff = func2.difficulty(func) + if diff == -1: + continue + possible.append((diff, repl, f, func2)) + + # find the nearest origin + possible.sort(key=lambda x: x[0]) + for _, repl, f, func2 in possible: + f2 = Formula(func2, f.z, None, [], f.B.subs(repl), + f.C.subs(repl), f.M.subs(repl)) + if not any(e.has(S.NaN, oo, -oo, zoo) for e in [f2.B, f2.M, f2.C]): + return f2 + + return None + + +class MeijerFormula: + """ + This class represents a Meijer G-function formula. + + Its data members are: + - z, the argument + - symbols, the free symbols (parameters) in the formula + - func, the function + - B, C, M (c/f ordinary Formula) + """ + + def __init__(self, an, ap, bm, bq, z, symbols, B, C, M, matcher): + an, ap, bm, bq = [Tuple(*list(map(expand, w))) for w in [an, ap, bm, bq]] + self.func = G_Function(an, ap, bm, bq) + self.z = z + self.symbols = symbols + self._matcher = matcher + self.B = B + self.C = C + self.M = M + + @property + def closed_form(self): + return reduce(lambda s,m: s+m[0]*m[1], zip(self.C, self.B), S.Zero) + + def try_instantiate(self, func): + """ + Try to instantiate the current formula to (almost) match func. + This uses the _matcher passed on init. + """ + if func.signature != self.func.signature: + return None + res = self._matcher(func) + if res is not None: + subs, newfunc = res + return MeijerFormula(newfunc.an, newfunc.ap, newfunc.bm, newfunc.bq, + self.z, [], + self.B.subs(subs), self.C.subs(subs), + self.M.subs(subs), None) + + +class MeijerFormulaCollection: + """ + This class holds a collection of meijer g formulae. + """ + + def __init__(self): + formulae = [] + add_meijerg_formulae(formulae) + self.formulae = defaultdict(list) + for formula in formulae: + self.formulae[formula.func.signature].append(formula) + self.formulae = dict(self.formulae) + + def lookup_origin(self, func): + """ Try to find a formula that matches func. """ + if func.signature not in self.formulae: + return None + for formula in self.formulae[func.signature]: + res = formula.try_instantiate(func) + if res is not None: + return res + + +class Operator: + """ + Base class for operators to be applied to our functions. + + Explanation + =========== + + These operators are differential operators. They are by convention + expressed in the variable D = z*d/dz (although this base class does + not actually care). + Note that when the operator is applied to an object, we typically do + *not* blindly differentiate but instead use a different representation + of the z*d/dz operator (see make_derivative_operator). + + To subclass from this, define a __init__ method that initializes a + self._poly variable. This variable stores a polynomial. By convention + the generator is z*d/dz, and acts to the right of all coefficients. + + Thus this poly + x**2 + 2*z*x + 1 + represents the differential operator + (z*d/dz)**2 + 2*z**2*d/dz. + + This class is used only in the implementation of the hypergeometric + function expansion algorithm. + """ + + def apply(self, obj, op): + """ + Apply ``self`` to the object ``obj``, where the generator is ``op``. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import Operator + >>> from sympy.polys.polytools import Poly + >>> from sympy.abc import x, y, z + >>> op = Operator() + >>> op._poly = Poly(x**2 + z*x + y, x) + >>> op.apply(z**7, lambda f: f.diff(z)) + y*z**7 + 7*z**7 + 42*z**5 + """ + coeffs = self._poly.all_coeffs() + coeffs.reverse() + diffs = [obj] + for c in coeffs[1:]: + diffs.append(op(diffs[-1])) + r = coeffs[0]*diffs[0] + for c, d in zip(coeffs[1:], diffs[1:]): + r += c*d + return r + + +class MultOperator(Operator): + """ Simply multiply by a "constant" """ + + def __init__(self, p): + self._poly = Poly(p, _x) + + +class ShiftA(Operator): + """ Increment an upper index. """ + + def __init__(self, ai): + ai = sympify(ai) + if ai == 0: + raise ValueError('Cannot increment zero upper index.') + self._poly = Poly(_x/ai + 1, _x) + + def __str__(self): + return '' % (1/self._poly.all_coeffs()[0]) + + +class ShiftB(Operator): + """ Decrement a lower index. """ + + def __init__(self, bi): + bi = sympify(bi) + if bi == 1: + raise ValueError('Cannot decrement unit lower index.') + self._poly = Poly(_x/(bi - 1) + 1, _x) + + def __str__(self): + return '' % (1/self._poly.all_coeffs()[0] + 1) + + +class UnShiftA(Operator): + """ Decrement an upper index. """ + + def __init__(self, ap, bq, i, z): + """ Note: i counts from zero! """ + ap, bq, i = list(map(sympify, [ap, bq, i])) + + self._ap = ap + self._bq = bq + self._i = i + + ap = list(ap) + bq = list(bq) + ai = ap.pop(i) - 1 + + if ai == 0: + raise ValueError('Cannot decrement unit upper index.') + + m = Poly(z*ai, _x) + for a in ap: + m *= Poly(_x + a, _x) + + A = Dummy('A') + n = D = Poly(ai*A - ai, A) + for b in bq: + n *= D + (b - 1).as_poly(A) + + b0 = -n.nth(0) + if b0 == 0: + raise ValueError('Cannot decrement upper index: ' + 'cancels with lower') + + n = Poly(Poly(n.all_coeffs()[:-1], A).as_expr().subs(A, _x/ai + 1), _x) + + self._poly = Poly((n - m)/b0, _x) + + def __str__(self): + return '' % (self._i, + self._ap, self._bq) + + +class UnShiftB(Operator): + """ Increment a lower index. """ + + def __init__(self, ap, bq, i, z): + """ Note: i counts from zero! """ + ap, bq, i = list(map(sympify, [ap, bq, i])) + + self._ap = ap + self._bq = bq + self._i = i + + ap = list(ap) + bq = list(bq) + bi = bq.pop(i) + 1 + + if bi == 0: + raise ValueError('Cannot increment -1 lower index.') + + m = Poly(_x*(bi - 1), _x) + for b in bq: + m *= Poly(_x + b - 1, _x) + + B = Dummy('B') + D = Poly((bi - 1)*B - bi + 1, B) + n = Poly(z, B) + for a in ap: + n *= (D + a.as_poly(B)) + + b0 = n.nth(0) + if b0 == 0: + raise ValueError('Cannot increment index: cancels with upper') + + n = Poly(Poly(n.all_coeffs()[:-1], B).as_expr().subs( + B, _x/(bi - 1) + 1), _x) + + self._poly = Poly((m - n)/b0, _x) + + def __str__(self): + return '' % (self._i, + self._ap, self._bq) + + +class MeijerShiftA(Operator): + """ Increment an upper b index. """ + + def __init__(self, bi): + bi = sympify(bi) + self._poly = Poly(bi - _x, _x) + + def __str__(self): + return '' % (self._poly.all_coeffs()[1]) + + +class MeijerShiftB(Operator): + """ Decrement an upper a index. """ + + def __init__(self, bi): + bi = sympify(bi) + self._poly = Poly(1 - bi + _x, _x) + + def __str__(self): + return '' % (1 - self._poly.all_coeffs()[1]) + + +class MeijerShiftC(Operator): + """ Increment a lower b index. """ + + def __init__(self, bi): + bi = sympify(bi) + self._poly = Poly(-bi + _x, _x) + + def __str__(self): + return '' % (-self._poly.all_coeffs()[1]) + + +class MeijerShiftD(Operator): + """ Decrement a lower a index. """ + + def __init__(self, bi): + bi = sympify(bi) + self._poly = Poly(bi - 1 - _x, _x) + + def __str__(self): + return '' % (self._poly.all_coeffs()[1] + 1) + + +class MeijerUnShiftA(Operator): + """ Decrement an upper b index. """ + + def __init__(self, an, ap, bm, bq, i, z): + """ Note: i counts from zero! """ + an, ap, bm, bq, i = list(map(sympify, [an, ap, bm, bq, i])) + + self._an = an + self._ap = ap + self._bm = bm + self._bq = bq + self._i = i + + an = list(an) + ap = list(ap) + bm = list(bm) + bq = list(bq) + bi = bm.pop(i) - 1 + + m = Poly(1, _x) * prod(Poly(b - _x, _x) for b in bm) * prod(Poly(_x - b, _x) for b in bq) + + A = Dummy('A') + D = Poly(bi - A, A) + n = Poly(z, A) * prod((D + 1 - a) for a in an) * prod((-D + a - 1) for a in ap) + + b0 = n.nth(0) + if b0 == 0: + raise ValueError('Cannot decrement upper b index (cancels)') + + n = Poly(Poly(n.all_coeffs()[:-1], A).as_expr().subs(A, bi - _x), _x) + + self._poly = Poly((m - n)/b0, _x) + + def __str__(self): + return '' % (self._i, + self._an, self._ap, self._bm, self._bq) + + +class MeijerUnShiftB(Operator): + """ Increment an upper a index. """ + + def __init__(self, an, ap, bm, bq, i, z): + """ Note: i counts from zero! """ + an, ap, bm, bq, i = list(map(sympify, [an, ap, bm, bq, i])) + + self._an = an + self._ap = ap + self._bm = bm + self._bq = bq + self._i = i + + an = list(an) + ap = list(ap) + bm = list(bm) + bq = list(bq) + ai = an.pop(i) + 1 + + m = Poly(z, _x) + for a in an: + m *= Poly(1 - a + _x, _x) + for a in ap: + m *= Poly(a - 1 - _x, _x) + + B = Dummy('B') + D = Poly(B + ai - 1, B) + n = Poly(1, B) + for b in bm: + n *= (-D + b) + for b in bq: + n *= (D - b) + + b0 = n.nth(0) + if b0 == 0: + raise ValueError('Cannot increment upper a index (cancels)') + + n = Poly(Poly(n.all_coeffs()[:-1], B).as_expr().subs( + B, 1 - ai + _x), _x) + + self._poly = Poly((m - n)/b0, _x) + + def __str__(self): + return '' % (self._i, + self._an, self._ap, self._bm, self._bq) + + +class MeijerUnShiftC(Operator): + """ Decrement a lower b index. """ + # XXX this is "essentially" the same as MeijerUnShiftA. This "essentially" + # can be made rigorous using the functional equation G(1/z) = G'(z), + # where G' denotes a G function of slightly altered parameters. + # However, sorting out the details seems harder than just coding it + # again. + + def __init__(self, an, ap, bm, bq, i, z): + """ Note: i counts from zero! """ + an, ap, bm, bq, i = list(map(sympify, [an, ap, bm, bq, i])) + + self._an = an + self._ap = ap + self._bm = bm + self._bq = bq + self._i = i + + an = list(an) + ap = list(ap) + bm = list(bm) + bq = list(bq) + bi = bq.pop(i) - 1 + + m = Poly(1, _x) + for b in bm: + m *= Poly(b - _x, _x) + for b in bq: + m *= Poly(_x - b, _x) + + C = Dummy('C') + D = Poly(bi + C, C) + n = Poly(z, C) + for a in an: + n *= (D + 1 - a) + for a in ap: + n *= (-D + a - 1) + + b0 = n.nth(0) + if b0 == 0: + raise ValueError('Cannot decrement lower b index (cancels)') + + n = Poly(Poly(n.all_coeffs()[:-1], C).as_expr().subs(C, _x - bi), _x) + + self._poly = Poly((m - n)/b0, _x) + + def __str__(self): + return '' % (self._i, + self._an, self._ap, self._bm, self._bq) + + +class MeijerUnShiftD(Operator): + """ Increment a lower a index. """ + # XXX This is essentially the same as MeijerUnShiftA. + # See comment at MeijerUnShiftC. + + def __init__(self, an, ap, bm, bq, i, z): + """ Note: i counts from zero! """ + an, ap, bm, bq, i = list(map(sympify, [an, ap, bm, bq, i])) + + self._an = an + self._ap = ap + self._bm = bm + self._bq = bq + self._i = i + + an = list(an) + ap = list(ap) + bm = list(bm) + bq = list(bq) + ai = ap.pop(i) + 1 + + m = Poly(z, _x) + for a in an: + m *= Poly(1 - a + _x, _x) + for a in ap: + m *= Poly(a - 1 - _x, _x) + + B = Dummy('B') # - this is the shift operator `D_I` + D = Poly(ai - 1 - B, B) + n = Poly(1, B) + for b in bm: + n *= (-D + b) + for b in bq: + n *= (D - b) + + b0 = n.nth(0) + if b0 == 0: + raise ValueError('Cannot increment lower a index (cancels)') + + n = Poly(Poly(n.all_coeffs()[:-1], B).as_expr().subs( + B, ai - 1 - _x), _x) + + self._poly = Poly((m - n)/b0, _x) + + def __str__(self): + return '' % (self._i, + self._an, self._ap, self._bm, self._bq) + + +class ReduceOrder(Operator): + """ Reduce Order by cancelling an upper and a lower index. """ + + def __new__(cls, ai, bj): + """ For convenience if reduction is not possible, return None. """ + ai = sympify(ai) + bj = sympify(bj) + n = ai - bj + if not n.is_Integer or n < 0: + return None + if bj.is_integer and bj.is_nonpositive: + return None + + expr = Operator.__new__(cls) + + p = S.One + for k in range(n): + p *= (_x + bj + k)/(bj + k) + + expr._poly = Poly(p, _x) + expr._a = ai + expr._b = bj + + return expr + + @classmethod + def _meijer(cls, b, a, sign): + """ Cancel b + sign*s and a + sign*s + This is for meijer G functions. """ + b = sympify(b) + a = sympify(a) + n = b - a + if n.is_negative or not n.is_Integer: + return None + + expr = Operator.__new__(cls) + + p = S.One + for k in range(n): + p *= (sign*_x + a + k) + + expr._poly = Poly(p, _x) + if sign == -1: + expr._a = b + expr._b = a + else: + expr._b = Add(1, a - 1, evaluate=False) + expr._a = Add(1, b - 1, evaluate=False) + + return expr + + @classmethod + def meijer_minus(cls, b, a): + return cls._meijer(b, a, -1) + + @classmethod + def meijer_plus(cls, a, b): + return cls._meijer(1 - a, 1 - b, 1) + + def __str__(self): + return '' % \ + (self._a, self._b) + + +def _reduce_order(ap, bq, gen, key): + """ Order reduction algorithm used in Hypergeometric and Meijer G """ + ap = list(ap) + bq = list(bq) + + ap.sort(key=key) + bq.sort(key=key) + + nap = [] + # we will edit bq in place + operators = [] + for a in ap: + op = None + for i in range(len(bq)): + op = gen(a, bq[i]) + if op is not None: + bq.pop(i) + break + if op is None: + nap.append(a) + else: + operators.append(op) + + return nap, bq, operators + + +def reduce_order(func): + """ + Given the hypergeometric function ``func``, find a sequence of operators to + reduces order as much as possible. + + Explanation + =========== + + Return (newfunc, [operators]), where applying the operators to the + hypergeometric function newfunc yields func. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import reduce_order, Hyper_Function + >>> reduce_order(Hyper_Function((1, 2), (3, 4))) + (Hyper_Function((1, 2), (3, 4)), []) + >>> reduce_order(Hyper_Function((1,), (1,))) + (Hyper_Function((), ()), []) + >>> reduce_order(Hyper_Function((2, 4), (3, 3))) + (Hyper_Function((2,), (3,)), []) + """ + nap, nbq, operators = _reduce_order(func.ap, func.bq, ReduceOrder, default_sort_key) + + return Hyper_Function(Tuple(*nap), Tuple(*nbq)), operators + + +def reduce_order_meijer(func): + """ + Given the Meijer G function parameters, ``func``, find a sequence of + operators that reduces order as much as possible. + + Return newfunc, [operators]. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import (reduce_order_meijer, + ... G_Function) + >>> reduce_order_meijer(G_Function([3, 4], [5, 6], [3, 4], [1, 2]))[0] + G_Function((4, 3), (5, 6), (3, 4), (2, 1)) + >>> reduce_order_meijer(G_Function([3, 4], [5, 6], [3, 4], [1, 8]))[0] + G_Function((3,), (5, 6), (3, 4), (1,)) + >>> reduce_order_meijer(G_Function([3, 4], [5, 6], [7, 5], [1, 5]))[0] + G_Function((3,), (), (), (1,)) + >>> reduce_order_meijer(G_Function([3, 4], [5, 6], [7, 5], [5, 3]))[0] + G_Function((), (), (), ()) + """ + + nan, nbq, ops1 = _reduce_order(func.an, func.bq, ReduceOrder.meijer_plus, + lambda x: default_sort_key(-x)) + nbm, nap, ops2 = _reduce_order(func.bm, func.ap, ReduceOrder.meijer_minus, + default_sort_key) + + return G_Function(nan, nap, nbm, nbq), ops1 + ops2 + + +def make_derivative_operator(M, z): + """ Create a derivative operator, to be passed to Operator.apply. """ + def doit(C): + r = z*C.diff(z) + C*M + r = r.applyfunc(make_simp(z)) + return r + return doit + + +def apply_operators(obj, ops, op): + """ + Apply the list of operators ``ops`` to object ``obj``, substituting + ``op`` for the generator. + """ + res = obj + for o in reversed(ops): + res = o.apply(res, op) + return res + + +def devise_plan(target, origin, z): + """ + Devise a plan (consisting of shift and un-shift operators) to be applied + to the hypergeometric function ``target`` to yield ``origin``. + Returns a list of operators. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import devise_plan, Hyper_Function + >>> from sympy.abc import z + + Nothing to do: + + >>> devise_plan(Hyper_Function((1, 2), ()), Hyper_Function((1, 2), ()), z) + [] + >>> devise_plan(Hyper_Function((), (1, 2)), Hyper_Function((), (1, 2)), z) + [] + + Very simple plans: + + >>> devise_plan(Hyper_Function((2,), ()), Hyper_Function((1,), ()), z) + [] + >>> devise_plan(Hyper_Function((), (2,)), Hyper_Function((), (1,)), z) + [] + + Several buckets: + + >>> from sympy import S + >>> devise_plan(Hyper_Function((1, S.Half), ()), + ... Hyper_Function((2, S('3/2')), ()), z) #doctest: +NORMALIZE_WHITESPACE + [, + ] + + A slightly more complicated plan: + + >>> devise_plan(Hyper_Function((1, 3), ()), Hyper_Function((2, 2), ()), z) + [, ] + + Another more complicated plan: (note that the ap have to be shifted first!) + + >>> devise_plan(Hyper_Function((1, -1), (2,)), Hyper_Function((3, -2), (4,)), z) + [, , + , + , ] + """ + abuckets, bbuckets, nabuckets, nbbuckets = [sift(params, _mod1) for + params in (target.ap, target.bq, origin.ap, origin.bq)] + + if len(list(abuckets.keys())) != len(list(nabuckets.keys())) or \ + len(list(bbuckets.keys())) != len(list(nbbuckets.keys())): + raise ValueError('%s not reachable from %s' % (target, origin)) + + ops = [] + + def do_shifts(fro, to, inc, dec): + ops = [] + for i in range(len(fro)): + if to[i] - fro[i] > 0: + sh = inc + ch = 1 + else: + sh = dec + ch = -1 + + while to[i] != fro[i]: + ops += [sh(fro, i)] + fro[i] += ch + + return ops + + def do_shifts_a(nal, nbk, al, aother, bother): + """ Shift us from (nal, nbk) to (al, nbk). """ + return do_shifts(nal, al, lambda p, i: ShiftA(p[i]), + lambda p, i: UnShiftA(p + aother, nbk + bother, i, z)) + + def do_shifts_b(nal, nbk, bk, aother, bother): + """ Shift us from (nal, nbk) to (nal, bk). """ + return do_shifts(nbk, bk, + lambda p, i: UnShiftB(nal + aother, p + bother, i, z), + lambda p, i: ShiftB(p[i])) + + for r in sorted(list(abuckets.keys()) + list(bbuckets.keys()), key=default_sort_key): + al = () + nal = () + bk = () + nbk = () + if r in abuckets: + al = abuckets[r] + nal = nabuckets[r] + if r in bbuckets: + bk = bbuckets[r] + nbk = nbbuckets[r] + if len(al) != len(nal) or len(bk) != len(nbk): + raise ValueError('%s not reachable from %s' % (target, origin)) + + al, nal, bk, nbk = [sorted(w, key=default_sort_key) + for w in [al, nal, bk, nbk]] + + def others(dic, key): + l = [] + for k in dic: + if k != key: + l.extend(dic[k]) + return l + aother = others(nabuckets, r) + bother = others(nbbuckets, r) + + if len(al) == 0: + # there can be no complications, just shift the bs as we please + ops += do_shifts_b([], nbk, bk, aother, bother) + elif len(bk) == 0: + # there can be no complications, just shift the as as we please + ops += do_shifts_a(nal, [], al, aother, bother) + else: + namax = nal[-1] + amax = al[-1] + + if nbk[0] - namax <= 0 or bk[0] - amax <= 0: + raise ValueError('Non-suitable parameters.') + + if namax - amax > 0: + # we are going to shift down - first do the as, then the bs + ops += do_shifts_a(nal, nbk, al, aother, bother) + ops += do_shifts_b(al, nbk, bk, aother, bother) + else: + # we are going to shift up - first do the bs, then the as + ops += do_shifts_b(nal, nbk, bk, aother, bother) + ops += do_shifts_a(nal, bk, al, aother, bother) + + nabuckets[r] = al + nbbuckets[r] = bk + + ops.reverse() + return ops + + +def try_shifted_sum(func, z): + """ Try to recognise a hypergeometric sum that starts from k > 0. """ + abuckets, bbuckets = sift(func.ap, _mod1), sift(func.bq, _mod1) + if len(abuckets[S.Zero]) != 1: + return None + r = abuckets[S.Zero][0] + if r <= 0: + return None + if S.Zero not in bbuckets: + return None + l = list(bbuckets[S.Zero]) + l.sort() + k = l[0] + if k <= 0: + return None + + nap = list(func.ap) + nap.remove(r) + nbq = list(func.bq) + nbq.remove(k) + k -= 1 + nap = [x - k for x in nap] + nbq = [x - k for x in nbq] + + ops = [] + for n in range(r - 1): + ops.append(ShiftA(n + 1)) + ops.reverse() + + fac = factorial(k)/z**k + fac *= Mul(*[rf(b, k) for b in nbq]) + fac /= Mul(*[rf(a, k) for a in nap]) + + ops += [MultOperator(fac)] + + p = 0 + for n in range(k): + m = z**n/factorial(n) + m *= Mul(*[rf(a, n) for a in nap]) + m /= Mul(*[rf(b, n) for b in nbq]) + p += m + + return Hyper_Function(nap, nbq), ops, -p + + +def try_polynomial(func, z): + """ Recognise polynomial cases. Returns None if not such a case. + Requires order to be fully reduced. """ + abuckets, bbuckets = sift(func.ap, _mod1), sift(func.bq, _mod1) + a0 = abuckets[S.Zero] + b0 = bbuckets[S.Zero] + a0.sort() + b0.sort() + al0 = [x for x in a0 if x <= 0] + bl0 = [x for x in b0 if x <= 0] + + if bl0 and all(a < bl0[-1] for a in al0): + return oo + if not al0: + return None + + a = al0[-1] + fac = 1 + res = S.One + for n in Tuple(*list(range(-a))): + fac *= z + fac /= n + 1 + fac *= Mul(*[a + n for a in func.ap]) + fac /= Mul(*[b + n for b in func.bq]) + res += fac + return res + + +def try_lerchphi(func): + """ + Try to find an expression for Hyper_Function ``func`` in terms of Lerch + Transcendents. + + Return None if no such expression can be found. + """ + # This is actually quite simple, and is described in Roach's paper, + # section 18. + # We don't need to implement the reduction to polylog here, this + # is handled by expand_func. + + # First we need to figure out if the summation coefficient is a rational + # function of the summation index, and construct that rational function. + abuckets, bbuckets = sift(func.ap, _mod1), sift(func.bq, _mod1) + + paired = {} + for key, value in abuckets.items(): + if key != 0 and key not in bbuckets: + return None + bvalue = bbuckets[key] + paired[key] = (list(value), list(bvalue)) + bbuckets.pop(key, None) + if bbuckets != {}: + return None + if S.Zero not in abuckets: + return None + aints, bints = paired[S.Zero] + # Account for the additional n! in denominator + paired[S.Zero] = (aints, bints + [1]) + + t = Dummy('t') + numer = S.One + denom = S.One + for key, (avalue, bvalue) in paired.items(): + if len(avalue) != len(bvalue): + return None + # Note that since order has been reduced fully, all the b are + # bigger than all the a they differ from by an integer. In particular + # if there are any negative b left, this function is not well-defined. + for a, b in zip(avalue, bvalue): + if (a - b).is_positive: + k = a - b + numer *= rf(b + t, k) + denom *= rf(b, k) + else: + k = b - a + numer *= rf(a, k) + denom *= rf(a + t, k) + + # Now do a partial fraction decomposition. + # We assemble two structures: a list monomials of pairs (a, b) representing + # a*t**b (b a non-negative integer), and a dict terms, where + # terms[a] = [(b, c)] means that there is a term b/(t-a)**c. + part = apart(numer/denom, t) + args = Add.make_args(part) + monomials = [] + terms = {} + for arg in args: + numer, denom = arg.as_numer_denom() + if not denom.has(t): + p = Poly(numer, t) + if not p.is_monomial: + raise TypeError("p should be monomial") + ((b, ), a) = p.LT() + monomials += [(a/denom, b)] + continue + if numer.has(t): + raise NotImplementedError('Need partial fraction decomposition' + ' with linear denominators') + indep, [dep] = denom.as_coeff_mul(t) + n = 1 + if dep.is_Pow: + n = dep.exp + dep = dep.base + if dep == t: + a = 0 + elif dep.is_Add: + a, tmp = dep.as_independent(t) + b = 1 + if tmp != t: + b, _ = tmp.as_independent(t) + if dep != b*t + a: + raise NotImplementedError('unrecognised form %s' % dep) + a /= b + indep *= b**n + else: + raise NotImplementedError('unrecognised form of partial fraction') + terms.setdefault(a, []).append((numer/indep, n)) + + # Now that we have this information, assemble our formula. All the + # monomials yield rational functions and go into one basis element. + # The terms[a] are related by differentiation. If the largest exponent is + # n, we need lerchphi(z, k, a) for k = 1, 2, ..., n. + # deriv maps a basis to its derivative, expressed as a C(z)-linear + # combination of other basis elements. + deriv = {} + coeffs = {} + z = Dummy('z') + monomials.sort(key=lambda x: x[1]) + mon = {0: 1/(1 - z)} + if monomials: + for k in range(monomials[-1][1]): + mon[k + 1] = z*mon[k].diff(z) + for a, n in monomials: + coeffs.setdefault(S.One, []).append(a*mon[n]) + for a, l in terms.items(): + for c, k in l: + coeffs.setdefault(lerchphi(z, k, a), []).append(c) + l.sort(key=lambda x: x[1]) + for k in range(2, l[-1][1] + 1): + deriv[lerchphi(z, k, a)] = [(-a, lerchphi(z, k, a)), + (1, lerchphi(z, k - 1, a))] + deriv[lerchphi(z, 1, a)] = [(-a, lerchphi(z, 1, a)), + (1/(1 - z), S.One)] + trans = {} + for n, b in enumerate([S.One] + list(deriv.keys())): + trans[b] = n + basis = [expand_func(b) for (b, _) in sorted(trans.items(), + key=lambda x:x[1])] + B = Matrix(basis) + C = Matrix([[0]*len(B)]) + for b, c in coeffs.items(): + C[trans[b]] = Add(*c) + M = zeros(len(B)) + for b, l in deriv.items(): + for c, b2 in l: + M[trans[b], trans[b2]] = c + return Formula(func, z, None, [], B, C, M) + + +def build_hypergeometric_formula(func): + """ + Create a formula object representing the hypergeometric function ``func``. + + """ + # We know that no `ap` are negative integers, otherwise "detect poly" + # would have kicked in. However, `ap` could be empty. In this case we can + # use a different basis. + # I'm not aware of a basis that works in all cases. + z = Dummy('z') + if func.ap: + afactors = [_x + a for a in func.ap] + bfactors = [_x + b - 1 for b in func.bq] + expr = _x*Mul(*bfactors) - z*Mul(*afactors) + poly = Poly(expr, _x) + n = poly.degree() + basis = [] + M = zeros(n) + for k in range(n): + a = func.ap[0] + k + basis += [hyper([a] + list(func.ap[1:]), func.bq, z)] + if k < n - 1: + M[k, k] = -a + M[k, k + 1] = a + B = Matrix(basis) + C = Matrix([[1] + [0]*(n - 1)]) + derivs = [eye(n)] + for k in range(n): + derivs.append(M*derivs[k]) + l = poly.all_coeffs() + l.reverse() + res = [0]*n + for k, c in enumerate(l): + for r, d in enumerate(C*derivs[k]): + res[r] += c*d + for k, c in enumerate(res): + M[n - 1, k] = -c/derivs[n - 1][0, n - 1]/poly.all_coeffs()[0] + return Formula(func, z, None, [], B, C, M) + else: + # Since there are no `ap`, none of the `bq` can be non-positive + # integers. + basis = [] + bq = list(func.bq[:]) + for i in range(len(bq)): + basis += [hyper([], bq, z)] + bq[i] += 1 + basis += [hyper([], bq, z)] + B = Matrix(basis) + n = len(B) + C = Matrix([[1] + [0]*(n - 1)]) + M = zeros(n) + M[0, n - 1] = z/Mul(*func.bq) + for k in range(1, n): + M[k, k - 1] = func.bq[k - 1] + M[k, k] = -func.bq[k - 1] + return Formula(func, z, None, [], B, C, M) + + +def hyperexpand_special(ap, bq, z): + """ + Try to find a closed-form expression for hyper(ap, bq, z), where ``z`` + is supposed to be a "special" value, e.g. 1. + + This function tries various of the classical summation formulae + (Gauss, Saalschuetz, etc). + """ + # This code is very ad-hoc. There are many clever algorithms + # (notably Zeilberger's) related to this problem. + # For now we just want a few simple cases to work. + p, q = len(ap), len(bq) + z_ = z + z = unpolarify(z) + if z == 0: + return S.One + from sympy.simplify.simplify import simplify + if p == 2 and q == 1: + # 2F1 + a, b, c = ap + bq + if z == 1: + # Gauss + return gamma(c - a - b)*gamma(c)/gamma(c - a)/gamma(c - b) + if z == -1 and simplify(b - a + c) == 1: + b, a = a, b + if z == -1 and simplify(a - b + c) == 1: + # Kummer + if b.is_integer and b.is_negative: + return 2*cos(pi*b/2)*gamma(-b)*gamma(b - a + 1) \ + /gamma(-b/2)/gamma(b/2 - a + 1) + else: + return gamma(b/2 + 1)*gamma(b - a + 1) \ + /gamma(b + 1)/gamma(b/2 - a + 1) + # TODO tons of more formulae + # investigate what algorithms exist + return hyper(ap, bq, z_) + +_collection = None + + +def _hyperexpand(func, z, ops0=[], z0=Dummy('z0'), premult=1, prem=0, + rewrite='default'): + """ + Try to find an expression for the hypergeometric function ``func``. + + Explanation + =========== + + The result is expressed in terms of a dummy variable ``z0``. Then it + is multiplied by ``premult``. Then ``ops0`` is applied. + ``premult`` must be a*z**prem for some a independent of ``z``. + """ + + if z.is_zero: + return S.One + + from sympy.simplify.simplify import simplify + + z = polarify(z, subs=False) + if rewrite == 'default': + rewrite = 'nonrepsmall' + + def carryout_plan(f, ops): + C = apply_operators(f.C.subs(f.z, z0), ops, + make_derivative_operator(f.M.subs(f.z, z0), z0)) + C = apply_operators(C, ops0, + make_derivative_operator(f.M.subs(f.z, z0) + + prem*eye(f.M.shape[0]), z0)) + + if premult == 1: + C = C.applyfunc(make_simp(z0)) + r = reduce(lambda s,m: s+m[0]*m[1], zip(C, f.B.subs(f.z, z0)), S.Zero)*premult + res = r.subs(z0, z) + if rewrite: + res = res.rewrite(rewrite) + return res + + # TODO + # The following would be possible: + # *) PFD Duplication (see Kelly Roach's paper) + # *) In a similar spirit, try_lerchphi() can be generalised considerably. + + global _collection + if _collection is None: + _collection = FormulaCollection() + + debug('Trying to expand hypergeometric function ', func) + + # First reduce order as much as possible. + func, ops = reduce_order(func) + if ops: + debug(' Reduced order to ', func) + else: + debug(' Could not reduce order.') + + # Now try polynomial cases + res = try_polynomial(func, z0) + if res is not None: + debug(' Recognised polynomial.') + p = apply_operators(res, ops, lambda f: z0*f.diff(z0)) + p = apply_operators(p*premult, ops0, lambda f: z0*f.diff(z0)) + return unpolarify(simplify(p).subs(z0, z)) + + # Try to recognise a shifted sum. + p = S.Zero + res = try_shifted_sum(func, z0) + if res is not None: + func, nops, p = res + debug(' Recognised shifted sum, reduced order to ', func) + ops += nops + + # apply the plan for poly + p = apply_operators(p, ops, lambda f: z0*f.diff(z0)) + p = apply_operators(p*premult, ops0, lambda f: z0*f.diff(z0)) + p = simplify(p).subs(z0, z) + + # Try special expansions early. + if unpolarify(z) in [1, -1] and (len(func.ap), len(func.bq)) == (2, 1): + f = build_hypergeometric_formula(func) + r = carryout_plan(f, ops).replace(hyper, hyperexpand_special) + if not r.has(hyper): + return r + p + + # Try to find a formula in our collection + formula = _collection.lookup_origin(func) + + # Now try a lerch phi formula + if formula is None: + formula = try_lerchphi(func) + + if formula is None: + debug(' Could not find an origin. ', + 'Will return answer in terms of ' + 'simpler hypergeometric functions.') + formula = build_hypergeometric_formula(func) + + debug(' Found an origin: ', formula.closed_form, ' ', formula.func) + + # We need to find the operators that convert formula into func. + ops += devise_plan(func, formula.func, z0) + + # Now carry out the plan. + r = carryout_plan(formula, ops) + p + + return powdenest(r, polar=True).replace(hyper, hyperexpand_special) + + +def devise_plan_meijer(fro, to, z): + """ + Find operators to convert G-function ``fro`` into G-function ``to``. + + Explanation + =========== + + It is assumed that ``fro`` and ``to`` have the same signatures, and that in fact + any corresponding pair of parameters differs by integers, and a direct path + is possible. I.e. if there are parameters a1 b1 c1 and a2 b2 c2 it is + assumed that a1 can be shifted to a2, etc. The only thing this routine + determines is the order of shifts to apply, nothing clever will be tried. + It is also assumed that ``fro`` is suitable. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import (devise_plan_meijer, + ... G_Function) + >>> from sympy.abc import z + + Empty plan: + + >>> devise_plan_meijer(G_Function([1], [2], [3], [4]), + ... G_Function([1], [2], [3], [4]), z) + [] + + Very simple plans: + + >>> devise_plan_meijer(G_Function([0], [], [], []), + ... G_Function([1], [], [], []), z) + [] + >>> devise_plan_meijer(G_Function([0], [], [], []), + ... G_Function([-1], [], [], []), z) + [] + >>> devise_plan_meijer(G_Function([], [1], [], []), + ... G_Function([], [2], [], []), z) + [] + + Slightly more complicated plans: + + >>> devise_plan_meijer(G_Function([0], [], [], []), + ... G_Function([2], [], [], []), z) + [, + ] + >>> devise_plan_meijer(G_Function([0], [], [0], []), + ... G_Function([-1], [], [1], []), z) + [, ] + + Order matters: + + >>> devise_plan_meijer(G_Function([0], [], [0], []), + ... G_Function([1], [], [1], []), z) + [, ] + """ + # TODO for now, we use the following simple heuristic: inverse-shift + # when possible, shift otherwise. Give up if we cannot make progress. + + def try_shift(f, t, shifter, diff, counter): + """ Try to apply ``shifter`` in order to bring some element in ``f`` + nearer to its counterpart in ``to``. ``diff`` is +/- 1 and + determines the effect of ``shifter``. Counter is a list of elements + blocking the shift. + + Return an operator if change was possible, else None. + """ + for idx, (a, b) in enumerate(zip(f, t)): + if ( + (a - b).is_integer and (b - a)/diff > 0 and + all(a != x for x in counter)): + sh = shifter(idx) + f[idx] += diff + return sh + fan = list(fro.an) + fap = list(fro.ap) + fbm = list(fro.bm) + fbq = list(fro.bq) + ops = [] + change = True + while change: + change = False + op = try_shift(fan, to.an, + lambda i: MeijerUnShiftB(fan, fap, fbm, fbq, i, z), + 1, fbm + fbq) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fap, to.ap, + lambda i: MeijerUnShiftD(fan, fap, fbm, fbq, i, z), + 1, fbm + fbq) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fbm, to.bm, + lambda i: MeijerUnShiftA(fan, fap, fbm, fbq, i, z), + -1, fan + fap) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fbq, to.bq, + lambda i: MeijerUnShiftC(fan, fap, fbm, fbq, i, z), + -1, fan + fap) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fan, to.an, lambda i: MeijerShiftB(fan[i]), -1, []) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fap, to.ap, lambda i: MeijerShiftD(fap[i]), -1, []) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fbm, to.bm, lambda i: MeijerShiftA(fbm[i]), 1, []) + if op is not None: + ops += [op] + change = True + continue + op = try_shift(fbq, to.bq, lambda i: MeijerShiftC(fbq[i]), 1, []) + if op is not None: + ops += [op] + change = True + continue + if fan != list(to.an) or fap != list(to.ap) or fbm != list(to.bm) or \ + fbq != list(to.bq): + raise NotImplementedError('Could not devise plan.') + ops.reverse() + return ops + +_meijercollection = None + + +def _meijergexpand(func, z0, allow_hyper=False, rewrite='default', + place=None): + """ + Try to find an expression for the Meijer G function specified + by the G_Function ``func``. If ``allow_hyper`` is True, then returning + an expression in terms of hypergeometric functions is allowed. + + Currently this just does Slater's theorem. + If expansions exist both at zero and at infinity, ``place`` + can be set to ``0`` or ``zoo`` for the preferred choice. + """ + global _meijercollection + if _meijercollection is None: + _meijercollection = MeijerFormulaCollection() + if rewrite == 'default': + rewrite = None + + func0 = func + debug('Try to expand Meijer G function corresponding to ', func) + + # We will play games with analytic continuation - rather use a fresh symbol + z = Dummy('z') + + func, ops = reduce_order_meijer(func) + if ops: + debug(' Reduced order to ', func) + else: + debug(' Could not reduce order.') + + # Try to find a direct formula + f = _meijercollection.lookup_origin(func) + if f is not None: + debug(' Found a Meijer G formula: ', f.func) + ops += devise_plan_meijer(f.func, func, z) + + # Now carry out the plan. + C = apply_operators(f.C.subs(f.z, z), ops, + make_derivative_operator(f.M.subs(f.z, z), z)) + + C = C.applyfunc(make_simp(z)) + r = C*f.B.subs(f.z, z) + r = r[0].subs(z, z0) + return powdenest(r, polar=True) + + debug(" Could not find a direct formula. Trying Slater's theorem.") + + # TODO the following would be possible: + # *) Paired Index Theorems + # *) PFD Duplication + # (See Kelly Roach's paper for details on either.) + # + # TODO Also, we tend to create combinations of gamma functions that can be + # simplified. + + def can_do(pbm, pap): + """ Test if slater applies. """ + for i in pbm: + if len(pbm[i]) > 1: + l = 0 + if i in pap: + l = len(pap[i]) + if l + 1 < len(pbm[i]): + return False + return True + + def do_slater(an, bm, ap, bq, z, zfinal): + # zfinal is the value that will eventually be substituted for z. + # We pass it to _hyperexpand to improve performance. + func = G_Function(an, bm, ap, bq) + _, pbm, pap, _ = func.compute_buckets() + if not can_do(pbm, pap): + return S.Zero, False + + cond = len(an) + len(ap) < len(bm) + len(bq) + if len(an) + len(ap) == len(bm) + len(bq): + cond = abs(z) < 1 + if cond is False: + return S.Zero, False + + res = S.Zero + for m in pbm: + if len(pbm[m]) == 1: + bh = pbm[m][0] + fac = 1 + bo = list(bm) + bo.remove(bh) + for bj in bo: + fac *= gamma(bj - bh) + for aj in an: + fac *= gamma(1 + bh - aj) + for bj in bq: + fac /= gamma(1 + bh - bj) + for aj in ap: + fac /= gamma(aj - bh) + nap = [1 + bh - a for a in list(an) + list(ap)] + nbq = [1 + bh - b for b in list(bo) + list(bq)] + + k = polar_lift(S.NegativeOne**(len(ap) - len(bm))) + harg = k*zfinal + # NOTE even though k "is" +-1, this has to be t/k instead of + # t*k ... we are using polar numbers for consistency! + premult = (t/k)**bh + hyp = _hyperexpand(Hyper_Function(nap, nbq), harg, ops, + t, premult, bh, rewrite=None) + res += fac * hyp + else: + b_ = pbm[m][0] + ki = [bi - b_ for bi in pbm[m][1:]] + u = len(ki) + li = [ai - b_ for ai in pap[m][:u + 1]] + bo = list(bm) + for b in pbm[m]: + bo.remove(b) + ao = list(ap) + for a in pap[m][:u]: + ao.remove(a) + lu = li[-1] + di = [l - k for (l, k) in zip(li, ki)] + + # We first work out the integrand: + s = Dummy('s') + integrand = z**s + for b in bm: + if not Mod(b, 1) and b.is_Number: + b = int(round(b)) + integrand *= gamma(b - s) + for a in an: + integrand *= gamma(1 - a + s) + for b in bq: + integrand /= gamma(1 - b + s) + for a in ap: + integrand /= gamma(a - s) + + # Now sum the finitely many residues: + # XXX This speeds up some cases - is it a good idea? + integrand = expand_func(integrand) + for r in range(int(round(lu))): + resid = residue(integrand, s, b_ + r) + resid = apply_operators(resid, ops, lambda f: z*f.diff(z)) + res -= resid + + # Now the hypergeometric term. + au = b_ + lu + k = polar_lift(S.NegativeOne**(len(ao) + len(bo) + 1)) + harg = k*zfinal + premult = (t/k)**au + nap = [1 + au - a for a in list(an) + list(ap)] + [1] + nbq = [1 + au - b for b in list(bm) + list(bq)] + + hyp = _hyperexpand(Hyper_Function(nap, nbq), harg, ops, + t, premult, au, rewrite=None) + + C = S.NegativeOne**(lu)/factorial(lu) + for i in range(u): + C *= S.NegativeOne**di[i]/rf(lu - li[i] + 1, di[i]) + for a in an: + C *= gamma(1 - a + au) + for b in bo: + C *= gamma(b - au) + for a in ao: + C /= gamma(a - au) + for b in bq: + C /= gamma(1 - b + au) + + res += C*hyp + + return res, cond + + t = Dummy('t') + slater1, cond1 = do_slater(func.an, func.bm, func.ap, func.bq, z, z0) + + def tr(l): + return [1 - x for x in l] + + for op in ops: + op._poly = Poly(op._poly.subs({z: 1/t, _x: -_x}), _x) + slater2, cond2 = do_slater(tr(func.bm), tr(func.an), tr(func.bq), tr(func.ap), + t, 1/z0) + + slater1 = powdenest(slater1.subs(z, z0), polar=True) + slater2 = powdenest(slater2.subs(t, 1/z0), polar=True) + if not isinstance(cond2, bool): + cond2 = cond2.subs(t, 1/z) + + m = func(z) + if m.delta > 0 or \ + (m.delta == 0 and len(m.ap) == len(m.bq) and + (re(m.nu) < -1) is not False and polar_lift(z0) == polar_lift(1)): + # The condition delta > 0 means that the convergence region is + # connected. Any expression we find can be continued analytically + # to the entire convergence region. + # The conditions delta==0, p==q, re(nu) < -1 imply that G is continuous + # on the positive reals, so the values at z=1 agree. + if cond1 is not False: + cond1 = True + if cond2 is not False: + cond2 = True + + if cond1 is True: + slater1 = slater1.rewrite(rewrite or 'nonrep') + else: + slater1 = slater1.rewrite(rewrite or 'nonrepsmall') + if cond2 is True: + slater2 = slater2.rewrite(rewrite or 'nonrep') + else: + slater2 = slater2.rewrite(rewrite or 'nonrepsmall') + + if cond1 is not False and cond2 is not False: + # If one condition is False, there is no choice. + if place == 0: + cond2 = False + if place == zoo: + cond1 = False + + if not isinstance(cond1, bool): + cond1 = cond1.subs(z, z0) + if not isinstance(cond2, bool): + cond2 = cond2.subs(z, z0) + + def weight(expr, cond): + if cond is True: + c0 = 0 + elif cond is False: + c0 = 1 + else: + c0 = 2 + if expr.has(oo, zoo, -oo, nan): + # XXX this actually should not happen, but consider + # S('meijerg(((0, -1/2, 0, -1/2, 1/2), ()), ((0,), + # (-1/2, -1/2, -1/2, -1)), exp_polar(I*pi))/4') + c0 = 3 + return (c0, expr.count(hyper), expr.count_ops()) + + w1 = weight(slater1, cond1) + w2 = weight(slater2, cond2) + if min(w1, w2) <= (0, 1, oo): + if w1 < w2: + return slater1 + else: + return slater2 + if max(w1[0], w2[0]) <= 1 and max(w1[1], w2[1]) <= 1: + return Piecewise((slater1, cond1), (slater2, cond2), (func0(z0), True)) + + # We couldn't find an expression without hypergeometric functions. + # TODO it would be helpful to give conditions under which the integral + # is known to diverge. + r = Piecewise((slater1, cond1), (slater2, cond2), (func0(z0), True)) + if r.has(hyper) and not allow_hyper: + debug(' Could express using hypergeometric functions, ' + 'but not allowed.') + if not r.has(hyper) or allow_hyper: + return r + + return func0(z0) + + +def hyperexpand(f, allow_hyper=False, rewrite='default', place=None): + """ + Expand hypergeometric functions. If allow_hyper is True, allow partial + simplification (that is a result different from input, + but still containing hypergeometric functions). + + If a G-function has expansions both at zero and at infinity, + ``place`` can be set to ``0`` or ``zoo`` to indicate the + preferred choice. + + Examples + ======== + + >>> from sympy.simplify.hyperexpand import hyperexpand + >>> from sympy.functions import hyper + >>> from sympy.abc import z + >>> hyperexpand(hyper([], [], z)) + exp(z) + + Non-hyperegeometric parts of the expression and hypergeometric expressions + that are not recognised are left unchanged: + + >>> hyperexpand(1 + hyper([1, 1, 1], [], z)) + hyper((1, 1, 1), (), z) + 1 + """ + f = sympify(f) + + def do_replace(ap, bq, z): + r = _hyperexpand(Hyper_Function(ap, bq), z, rewrite=rewrite) + if r is None: + return hyper(ap, bq, z) + else: + return r + + def do_meijer(ap, bq, z): + r = _meijergexpand(G_Function(ap[0], ap[1], bq[0], bq[1]), z, + allow_hyper, rewrite=rewrite, place=place) + if not r.has(nan, zoo, oo, -oo): + return r + return f.replace(hyper, do_replace).replace(meijerg, do_meijer) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/hyperexpand_doc.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/hyperexpand_doc.py new file mode 100644 index 0000000000000000000000000000000000000000..a18377f3aede5214036fbf628825536611001584 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/hyperexpand_doc.py @@ -0,0 +1,18 @@ +""" This module cooks up a docstring when imported. Its only purpose is to + be displayed in the sphinx documentation. """ + +from sympy.core.relational import Eq +from sympy.functions.special.hyper import hyper +from sympy.printing.latex import latex +from sympy.simplify.hyperexpand import FormulaCollection + +c = FormulaCollection() + +doc = "" + +for f in c.formulae: + obj = Eq(hyper(f.func.ap, f.func.bq, f.z), + f.closed_form.rewrite('nonrepsmall')) + doc += ".. math::\n %s\n" % latex(obj) + +__doc__ = doc diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/powsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/powsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..f72dfeb072e0d0d4737ace310eda5c2a3a082c16 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/powsimp.py @@ -0,0 +1,718 @@ +from collections import defaultdict +from functools import reduce +from math import prod + +from sympy.core.function import expand_log, count_ops, _coeff_isneg +from sympy.core import sympify, Basic, Dummy, S, Add, Mul, Pow, expand_mul, factor_terms +from sympy.core.sorting import ordered, default_sort_key +from sympy.core.numbers import Integer, Rational, equal_valued +from sympy.core.mul import _keep_coeff +from sympy.core.rules import Transform +from sympy.functions import exp_polar, exp, log, root, polarify, unpolarify +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.polys import lcm, gcd +from sympy.ntheory.factor_ import multiplicity + + + +def powsimp(expr, deep=False, combine='all', force=False, measure=count_ops): + """ + Reduce expression by combining powers with similar bases and exponents. + + Explanation + =========== + + If ``deep`` is ``True`` then powsimp() will also simplify arguments of + functions. By default ``deep`` is set to ``False``. + + If ``force`` is ``True`` then bases will be combined without checking for + assumptions, e.g. sqrt(x)*sqrt(y) -> sqrt(x*y) which is not true + if x and y are both negative. + + You can make powsimp() only combine bases or only combine exponents by + changing combine='base' or combine='exp'. By default, combine='all', + which does both. combine='base' will only combine:: + + a a a 2x x + x * y => (x*y) as well as things like 2 => 4 + + and combine='exp' will only combine + :: + + a b (a + b) + x * x => x + + combine='exp' will strictly only combine exponents in the way that used + to be automatic. Also use deep=True if you need the old behavior. + + When combine='all', 'exp' is evaluated first. Consider the first + example below for when there could be an ambiguity relating to this. + This is done so things like the second example can be completely + combined. If you want 'base' combined first, do something like + powsimp(powsimp(expr, combine='base'), combine='exp'). + + Examples + ======== + + >>> from sympy import powsimp, exp, log, symbols + >>> from sympy.abc import x, y, z, n + >>> powsimp(x**y*x**z*y**z, combine='all') + x**(y + z)*y**z + >>> powsimp(x**y*x**z*y**z, combine='exp') + x**(y + z)*y**z + >>> powsimp(x**y*x**z*y**z, combine='base', force=True) + x**y*(x*y)**z + + >>> powsimp(x**z*x**y*n**z*n**y, combine='all', force=True) + (n*x)**(y + z) + >>> powsimp(x**z*x**y*n**z*n**y, combine='exp') + n**(y + z)*x**(y + z) + >>> powsimp(x**z*x**y*n**z*n**y, combine='base', force=True) + (n*x)**y*(n*x)**z + + >>> x, y = symbols('x y', positive=True) + >>> powsimp(log(exp(x)*exp(y))) + log(exp(x)*exp(y)) + >>> powsimp(log(exp(x)*exp(y)), deep=True) + x + y + + Radicals with Mul bases will be combined if combine='exp' + + >>> from sympy import sqrt + >>> x, y = symbols('x y') + + Two radicals are automatically joined through Mul: + + >>> a=sqrt(x*sqrt(y)) + >>> a*a**3 == a**4 + True + + But if an integer power of that radical has been + autoexpanded then Mul does not join the resulting factors: + + >>> a**4 # auto expands to a Mul, no longer a Pow + x**2*y + >>> _*a # so Mul doesn't combine them + x**2*y*sqrt(x*sqrt(y)) + >>> powsimp(_) # but powsimp will + (x*sqrt(y))**(5/2) + >>> powsimp(x*y*a) # but won't when doing so would violate assumptions + x*y*sqrt(x*sqrt(y)) + + """ + def recurse(arg, **kwargs): + _deep = kwargs.get('deep', deep) + _combine = kwargs.get('combine', combine) + _force = kwargs.get('force', force) + _measure = kwargs.get('measure', measure) + return powsimp(arg, _deep, _combine, _force, _measure) + + expr = sympify(expr) + + if (not isinstance(expr, Basic) or isinstance(expr, MatrixSymbol) or ( + expr.is_Atom or expr in (exp_polar(0), exp_polar(1)))): + return expr + + if deep or expr.is_Add or expr.is_Mul and _y not in expr.args: + expr = expr.func(*[recurse(w) for w in expr.args]) + + if expr.is_Pow: + return recurse(expr*_y, deep=False)/_y + + if not expr.is_Mul: + return expr + + # handle the Mul + if combine in ('exp', 'all'): + # Collect base/exp data, while maintaining order in the + # non-commutative parts of the product + c_powers = defaultdict(list) + nc_part = [] + newexpr = [] + coeff = S.One + for term in expr.args: + if term.is_Rational: + coeff *= term + continue + if term.is_Pow: + term = _denest_pow(term) + if term.is_commutative: + b, e = term.as_base_exp() + if deep: + b, e = [recurse(i) for i in [b, e]] + if b.is_Pow or isinstance(b, exp): + # don't let smthg like sqrt(x**a) split into x**a, 1/2 + # or else it will be joined as x**(a/2) later + b, e = b**e, S.One + c_powers[b].append(e) + else: + # This is the logic that combines exponents for equal, + # but non-commutative bases: A**x*A**y == A**(x+y). + if nc_part: + b1, e1 = nc_part[-1].as_base_exp() + b2, e2 = term.as_base_exp() + if (b1 == b2 and + e1.is_commutative and e2.is_commutative): + nc_part[-1] = Pow(b1, Add(e1, e2)) + continue + nc_part.append(term) + + # add up exponents of common bases + for b, e in ordered(iter(c_powers.items())): + # allow 2**x/4 -> 2**(x - 2); don't do this when b and e are + # Numbers since autoevaluation will undo it, e.g. + # 2**(1/3)/4 -> 2**(1/3 - 2) -> 2**(1/3)/4 + if (b and b.is_Rational and not all(ei.is_Number for ei in e) and \ + coeff is not S.One and + b not in (S.One, S.NegativeOne)): + m = multiplicity(abs(b), abs(coeff)) + if m: + e.append(m) + coeff /= b**m + c_powers[b] = Add(*e) + if coeff is not S.One: + if coeff in c_powers: + c_powers[coeff] += S.One + else: + c_powers[coeff] = S.One + + # convert to plain dictionary + c_powers = dict(c_powers) + + # check for base and inverted base pairs + be = list(c_powers.items()) + skip = set() # skip if we already saw them + for b, e in be: + if b in skip: + continue + bpos = b.is_positive or b.is_polar + if bpos: + binv = 1/b + #Special case for float 1 + if b.is_Float and equal_valued(b, 1): + c_powers[b] = S.One + continue + if b != binv and binv in c_powers: + if b.as_numer_denom()[0] is S.One: + c_powers.pop(b) + c_powers[binv] -= e + else: + skip.add(binv) + e = c_powers.pop(binv) + c_powers[b] -= e + + # check for base and negated base pairs + be = list(c_powers.items()) + _n = S.NegativeOne + for b, e in be: + if (b.is_Symbol or b.is_Add) and -b in c_powers and b in c_powers: + if (b.is_positive is not None or e.is_integer): + if e.is_integer or b.is_negative: + c_powers[-b] += c_powers.pop(b) + else: # (-b).is_positive so use its e + e = c_powers.pop(-b) + c_powers[b] += e + if _n in c_powers: + c_powers[_n] += e + else: + c_powers[_n] = e + + # filter c_powers and convert to a list + c_powers = [(b, e) for b, e in c_powers.items() if e] + + # ============================================================== + # check for Mul bases of Rational powers that can be combined with + # separated bases, e.g. x*sqrt(x*y)*sqrt(x*sqrt(x*y)) -> + # (x*sqrt(x*y))**(3/2) + # ---------------- helper functions + + def ratq(x): + '''Return Rational part of x's exponent as it appears in the bkey. + ''' + return bkey(x)[0][1] + + def bkey(b, e=None): + '''Return (b**s, c.q), c.p where e -> c*s. If e is not given then + it will be taken by using as_base_exp() on the input b. + e.g. + x**3/2 -> (x, 2), 3 + x**y -> (x**y, 1), 1 + x**(2*y/3) -> (x**y, 3), 2 + exp(x/2) -> (exp(a), 2), 1 + + ''' + if e is not None: # coming from c_powers or from below + if e.is_Integer: + return (b, S.One), e + elif e.is_Rational: + return (b, Integer(e.q)), Integer(e.p) + else: + c, m = e.as_coeff_Mul(rational=True) + if c is not S.One: + if m.is_integer: + return (b, Integer(c.q)), m*Integer(c.p) + return (b**m, Integer(c.q)), Integer(c.p) + else: + return (b**e, S.One), S.One + else: + return bkey(*b.as_base_exp()) + + def update(b): + '''Decide what to do with base, b. If its exponent is now an + integer multiple of the Rational denominator, then remove it + and put the factors of its base in the common_b dictionary or + update the existing bases if necessary. If it has been zeroed + out, simply remove the base. + ''' + newe, r = divmod(common_b[b], b[1]) + if not r: + common_b.pop(b) + if newe: + for m in Mul.make_args(b[0]**newe): + b, e = bkey(m) + if b not in common_b: + common_b[b] = 0 + common_b[b] += e + if b[1] != 1: + bases.append(b) + # ---------------- end of helper functions + + # assemble a dictionary of the factors having a Rational power + common_b = {} + done = [] + bases = [] + for b, e in c_powers: + b, e = bkey(b, e) + if b in common_b: + common_b[b] = common_b[b] + e + else: + common_b[b] = e + if b[1] != 1 and b[0].is_Mul: + bases.append(b) + bases.sort(key=default_sort_key) # this makes tie-breaking canonical + bases.sort(key=measure, reverse=True) # handle longest first + for base in bases: + if base not in common_b: # it may have been removed already + continue + b, exponent = base + last = False # True when no factor of base is a radical + qlcm = 1 # the lcm of the radical denominators + while True: + bstart = b + qstart = qlcm + + bb = [] # list of factors + ee = [] # (factor's expo. and it's current value in common_b) + for bi in Mul.make_args(b): + bib, bie = bkey(bi) + if bib not in common_b or common_b[bib] < bie: + ee = bb = [] # failed + break + ee.append([bie, common_b[bib]]) + bb.append(bib) + if ee: + # find the number of integral extractions possible + # e.g. [(1, 2), (2, 2)] -> min(2/1, 2/2) -> 1 + min1 = ee[0][1]//ee[0][0] + for i in range(1, len(ee)): + rat = ee[i][1]//ee[i][0] + if rat < 1: + break + min1 = min(min1, rat) + else: + # update base factor counts + # e.g. if ee = [(2, 5), (3, 6)] then min1 = 2 + # and the new base counts will be 5-2*2 and 6-2*3 + for i in range(len(bb)): + common_b[bb[i]] -= min1*ee[i][0] + update(bb[i]) + # update the count of the base + # e.g. x**2*y*sqrt(x*sqrt(y)) the count of x*sqrt(y) + # will increase by 4 to give bkey (x*sqrt(y), 2, 5) + common_b[base] += min1*qstart*exponent + if (last # no more radicals in base + or len(common_b) == 1 # nothing left to join with + or all(k[1] == 1 for k in common_b) # no rad's in common_b + ): + break + # see what we can exponentiate base by to remove any radicals + # so we know what to search for + # e.g. if base were x**(1/2)*y**(1/3) then we should + # exponentiate by 6 and look for powers of x and y in the ratio + # of 2 to 3 + qlcm = lcm([ratq(bi) for bi in Mul.make_args(bstart)]) + if qlcm == 1: + break # we are done + b = bstart**qlcm + qlcm *= qstart + if all(ratq(bi) == 1 for bi in Mul.make_args(b)): + last = True # we are going to be done after this next pass + # this base no longer can find anything to join with and + # since it was longer than any other we are done with it + b, q = base + done.append((b, common_b.pop(base)*Rational(1, q))) + + # update c_powers and get ready to continue with powsimp + c_powers = done + # there may be terms still in common_b that were bases that were + # identified as needing processing, so remove those, too + for (b, q), e in common_b.items(): + if (b.is_Pow or isinstance(b, exp)) and \ + q is not S.One and not b.exp.is_Rational: + b, be = b.as_base_exp() + b = b**(be/q) + else: + b = root(b, q) + c_powers.append((b, e)) + check = len(c_powers) + c_powers = dict(c_powers) + assert len(c_powers) == check # there should have been no duplicates + # ============================================================== + + # rebuild the expression + newexpr = expr.func(*(newexpr + [Pow(b, e) for b, e in c_powers.items()])) + if combine == 'exp': + return expr.func(newexpr, expr.func(*nc_part)) + else: + return recurse(expr.func(*nc_part), combine='base') * \ + recurse(newexpr, combine='base') + + elif combine == 'base': + + # Build c_powers and nc_part. These must both be lists not + # dicts because exp's are not combined. + c_powers = [] + nc_part = [] + for term in expr.args: + if term.is_commutative: + c_powers.append(list(term.as_base_exp())) + else: + nc_part.append(term) + + # Pull out numerical coefficients from exponent if assumptions allow + # e.g., 2**(2*x) => 4**x + for i in range(len(c_powers)): + b, e = c_powers[i] + if not (all(x.is_nonnegative for x in b.as_numer_denom()) or e.is_integer or force or b.is_polar): + continue + exp_c, exp_t = e.as_coeff_Mul(rational=True) + if exp_c is not S.One and exp_t is not S.One: + c_powers[i] = [Pow(b, exp_c), exp_t] + + # Combine bases whenever they have the same exponent and + # assumptions allow + # first gather the potential bases under the common exponent + c_exp = defaultdict(list) + for b, e in c_powers: + if deep: + e = recurse(e) + if e.is_Add and (b.is_positive or e.is_integer): + e = factor_terms(e) + if _coeff_isneg(e): + e = -e + b = 1/b + c_exp[e].append(b) + del c_powers + + # Merge back in the results of the above to form a new product + c_powers = defaultdict(list) + for e in c_exp: + bases = c_exp[e] + + # calculate the new base for e + + if len(bases) == 1: + new_base = bases[0] + elif e.is_integer or force: + new_base = expr.func(*bases) + else: + # see which ones can be joined + unk = [] + nonneg = [] + neg = [] + for bi in bases: + if bi.is_negative: + neg.append(bi) + elif bi.is_nonnegative: + nonneg.append(bi) + elif bi.is_polar: + nonneg.append( + bi) # polar can be treated like non-negative + else: + unk.append(bi) + if len(unk) == 1 and not neg or len(neg) == 1 and not unk: + # a single neg or a single unk can join the rest + nonneg.extend(unk + neg) + unk = neg = [] + elif neg: + # their negative signs cancel in groups of 2*q if we know + # that e = p/q else we have to treat them as unknown + israt = False + if e.is_Rational: + israt = True + else: + p, d = e.as_numer_denom() + if p.is_integer and d.is_integer: + israt = True + if israt: + neg = [-w for w in neg] + unk.extend([S.NegativeOne]*len(neg)) + else: + unk.extend(neg) + neg = [] + del israt + + # these shouldn't be joined + for b in unk: + c_powers[b].append(e) + # here is a new joined base + new_base = expr.func(*(nonneg + neg)) + # if there are positive parts they will just get separated + # again unless some change is made + + def _terms(e): + # return the number of terms of this expression + # when multiplied out -- assuming no joining of terms + if e.is_Add: + return sum(_terms(ai) for ai in e.args) + if e.is_Mul: + return prod([_terms(mi) for mi in e.args]) + return 1 + xnew_base = expand_mul(new_base, deep=False) + if len(Add.make_args(xnew_base)) < _terms(new_base): + new_base = factor_terms(xnew_base) + + c_powers[new_base].append(e) + + # break out the powers from c_powers now + c_part = [Pow(b, ei) for b, e in c_powers.items() for ei in e] + + # we're done + return expr.func(*(c_part + nc_part)) + + else: + raise ValueError("combine must be one of ('all', 'exp', 'base').") + + +def powdenest(eq, force=False, polar=False): + r""" + Collect exponents on powers as assumptions allow. + + Explanation + =========== + + Given ``(bb**be)**e``, this can be simplified as follows: + * if ``bb`` is positive, or + * ``e`` is an integer, or + * ``|be| < 1`` then this simplifies to ``bb**(be*e)`` + + Given a product of powers raised to a power, ``(bb1**be1 * + bb2**be2...)**e``, simplification can be done as follows: + + - if e is positive, the gcd of all bei can be joined with e; + - all non-negative bb can be separated from those that are negative + and their gcd can be joined with e; autosimplification already + handles this separation. + - integer factors from powers that have integers in the denominator + of the exponent can be removed from any term and the gcd of such + integers can be joined with e + + Setting ``force`` to ``True`` will make symbols that are not explicitly + negative behave as though they are positive, resulting in more + denesting. + + Setting ``polar`` to ``True`` will do simplifications on the Riemann surface of + the logarithm, also resulting in more denestings. + + When there are sums of logs in exp() then a product of powers may be + obtained e.g. ``exp(3*(log(a) + 2*log(b)))`` - > ``a**3*b**6``. + + Examples + ======== + + >>> from sympy.abc import a, b, x, y, z + >>> from sympy import Symbol, exp, log, sqrt, symbols, powdenest + + >>> powdenest((x**(2*a/3))**(3*x)) + (x**(2*a/3))**(3*x) + >>> powdenest(exp(3*x*log(2))) + 2**(3*x) + + Assumptions may prevent expansion: + + >>> powdenest(sqrt(x**2)) + sqrt(x**2) + + >>> p = symbols('p', positive=True) + >>> powdenest(sqrt(p**2)) + p + + No other expansion is done. + + >>> i, j = symbols('i,j', integer=True) + >>> powdenest((x**x)**(i + j)) # -X-> (x**x)**i*(x**x)**j + x**(x*(i + j)) + + But exp() will be denested by moving all non-log terms outside of + the function; this may result in the collapsing of the exp to a power + with a different base: + + >>> powdenest(exp(3*y*log(x))) + x**(3*y) + >>> powdenest(exp(y*(log(a) + log(b)))) + (a*b)**y + >>> powdenest(exp(3*(log(a) + log(b)))) + a**3*b**3 + + If assumptions allow, symbols can also be moved to the outermost exponent: + + >>> i = Symbol('i', integer=True) + >>> powdenest(((x**(2*i))**(3*y))**x) + ((x**(2*i))**(3*y))**x + >>> powdenest(((x**(2*i))**(3*y))**x, force=True) + x**(6*i*x*y) + + >>> powdenest(((x**(2*a/3))**(3*y/i))**x) + ((x**(2*a/3))**(3*y/i))**x + >>> powdenest((x**(2*i)*y**(4*i))**z, force=True) + (x*y**2)**(2*i*z) + + >>> n = Symbol('n', negative=True) + + >>> powdenest((x**i)**y, force=True) + x**(i*y) + >>> powdenest((n**i)**x, force=True) + (n**i)**x + + """ + from sympy.simplify.simplify import posify + + if force: + def _denest(b, e): + if not isinstance(b, (Pow, exp)): + return b.is_positive, Pow(b, e, evaluate=False) + return _denest(b.base, b.exp*e) + reps = [] + for p in eq.atoms(Pow, exp): + if isinstance(p.base, (Pow, exp)): + ok, dp = _denest(*p.args) + if ok is not False: + reps.append((p, dp)) + if reps: + eq = eq.subs(reps) + eq, reps = posify(eq) + return powdenest(eq, force=False, polar=polar).xreplace(reps) + + if polar: + eq, rep = polarify(eq) + return unpolarify(powdenest(unpolarify(eq, exponents_only=True)), rep) + + new = powsimp(eq) + return new.xreplace(Transform( + _denest_pow, filter=lambda m: m.is_Pow or isinstance(m, exp))) + +_y = Dummy('y') + + +def _denest_pow(eq): + """ + Denest powers. + + This is a helper function for powdenest that performs the actual + transformation. + """ + from sympy.simplify.simplify import logcombine + + b, e = eq.as_base_exp() + if b.is_Pow or isinstance(b, exp) and e != 1: + new = b._eval_power(e) + if new is not None: + eq = new + b, e = new.as_base_exp() + + # denest exp with log terms in exponent + if b is S.Exp1 and e.is_Mul: + logs = [] + other = [] + for ei in e.args: + if any(isinstance(ai, log) for ai in Add.make_args(ei)): + logs.append(ei) + else: + other.append(ei) + logs = logcombine(Mul(*logs)) + return Pow(exp(logs), Mul(*other)) + + _, be = b.as_base_exp() + if be is S.One and not (b.is_Mul or + b.is_Rational and b.q != 1 or + b.is_positive): + return eq + + # denest eq which is either pos**e or Pow**e or Mul**e or + # Mul(b1**e1, b2**e2) + + # handle polar numbers specially + polars, nonpolars = [], [] + for bb in Mul.make_args(b): + if bb.is_polar: + polars.append(bb.as_base_exp()) + else: + nonpolars.append(bb) + if len(polars) == 1 and not polars[0][0].is_Mul: + return Pow(polars[0][0], polars[0][1]*e)*powdenest(Mul(*nonpolars)**e) + elif polars: + return Mul(*[powdenest(bb**(ee*e)) for (bb, ee) in polars]) \ + *powdenest(Mul(*nonpolars)**e) + + if b.is_Integer: + # use log to see if there is a power here + logb = expand_log(log(b)) + if logb.is_Mul: + c, logb = logb.args + e *= c + base = logb.args[0] + return Pow(base, e) + + # if b is not a Mul or any factor is an atom then there is nothing to do + if not b.is_Mul or any(s.is_Atom for s in Mul.make_args(b)): + return eq + + # let log handle the case of the base of the argument being a Mul, e.g. + # sqrt(x**(2*i)*y**(6*i)) -> x**i*y**(3**i) if x and y are positive; we + # will take the log, expand it, and then factor out the common powers that + # now appear as coefficient. We do this manually since terms_gcd pulls out + # fractions, terms_gcd(x+x*y/2) -> x*(y + 2)/2 and we don't want the 1/2; + # gcd won't pull out numerators from a fraction: gcd(3*x, 9*x/2) -> x but + # we want 3*x. Neither work with noncommutatives. + + def nc_gcd(aa, bb): + a, b = [i.as_coeff_Mul() for i in [aa, bb]] + c = gcd(a[0], b[0]).as_numer_denom()[0] + g = Mul(*(a[1].args_cnc(cset=True)[0] & b[1].args_cnc(cset=True)[0])) + return _keep_coeff(c, g) + + glogb = expand_log(log(b)) + if glogb.is_Add: + args = glogb.args + g = reduce(nc_gcd, args) + if g != 1: + cg, rg = g.as_coeff_Mul() + glogb = _keep_coeff(cg, rg*Add(*[a/g for a in args])) + + # now put the log back together again + if isinstance(glogb, log) or not glogb.is_Mul: + if glogb.args[0].is_Pow or isinstance(glogb.args[0], exp): + glogb = _denest_pow(glogb.args[0]) + if (abs(glogb.exp) < 1) == True: + return Pow(glogb.base, glogb.exp*e) + return eq + + # the log(b) was a Mul so join any adds with logcombine + add = [] + other = [] + for a in glogb.args: + if a.is_Add: + add.append(a) + else: + other.append(a) + return Pow(exp(logcombine(Mul(*add))), e*Mul(*other)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/radsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/radsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..c878168ebfbc29fc632577d6325befc120c26f56 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/radsimp.py @@ -0,0 +1,1234 @@ +from collections import defaultdict + +from sympy.core import sympify, S, Mul, Derivative, Pow +from sympy.core.add import _unevaluated_Add, Add +from sympy.core.assumptions import assumptions +from sympy.core.exprtools import Factors, gcd_terms +from sympy.core.function import _mexpand, expand_mul, expand_power_base +from sympy.core.mul import _keep_coeff, _unevaluated_Mul, _mulsort +from sympy.core.numbers import Rational, zoo, nan +from sympy.core.parameters import global_parameters +from sympy.core.sorting import ordered, default_sort_key +from sympy.core.symbol import Dummy, Wild, symbols +from sympy.functions import exp, sqrt, log +from sympy.functions.elementary.complexes import Abs +from sympy.polys import gcd +from sympy.simplify.sqrtdenest import sqrtdenest +from sympy.utilities.iterables import iterable, sift + + + + +def collect(expr, syms, func=None, evaluate=None, exact=False, distribute_order_term=True): + """ + Collect additive terms of an expression. + + Explanation + =========== + + This function collects additive terms of an expression with respect + to a list of expression up to powers with rational exponents. By the + term symbol here are meant arbitrary expressions, which can contain + powers, products, sums etc. In other words symbol is a pattern which + will be searched for in the expression's terms. + + The input expression is not expanded by :func:`collect`, so user is + expected to provide an expression in an appropriate form. This makes + :func:`collect` more predictable as there is no magic happening behind the + scenes. However, it is important to note, that powers of products are + converted to products of powers using the :func:`~.expand_power_base` + function. + + There are two possible types of output. First, if ``evaluate`` flag is + set, this function will return an expression with collected terms or + else it will return a dictionary with expressions up to rational powers + as keys and collected coefficients as values. + + Examples + ======== + + >>> from sympy import S, collect, expand, factor, Wild + >>> from sympy.abc import a, b, c, x, y + + This function can collect symbolic coefficients in polynomials or + rational expressions. It will manage to find all integer or rational + powers of collection variable:: + + >>> collect(a*x**2 + b*x**2 + a*x - b*x + c, x) + c + x**2*(a + b) + x*(a - b) + + The same result can be achieved in dictionary form:: + + >>> d = collect(a*x**2 + b*x**2 + a*x - b*x + c, x, evaluate=False) + >>> d[x**2] + a + b + >>> d[x] + a - b + >>> d[S.One] + c + + You can also work with multivariate polynomials. However, remember that + this function is greedy so it will care only about a single symbol at time, + in specification order:: + + >>> collect(x**2 + y*x**2 + x*y + y + a*y, [x, y]) + x**2*(y + 1) + x*y + y*(a + 1) + + Also more complicated expressions can be used as patterns:: + + >>> from sympy import sin, log + >>> collect(a*sin(2*x) + b*sin(2*x), sin(2*x)) + (a + b)*sin(2*x) + + >>> collect(a*x*log(x) + b*(x*log(x)), x*log(x)) + x*(a + b)*log(x) + + You can use wildcards in the pattern:: + + >>> w = Wild('w1') + >>> collect(a*x**y - b*x**y, w**y) + x**y*(a - b) + + It is also possible to work with symbolic powers, although it has more + complicated behavior, because in this case power's base and symbolic part + of the exponent are treated as a single symbol:: + + >>> collect(a*x**c + b*x**c, x) + a*x**c + b*x**c + >>> collect(a*x**c + b*x**c, x**c) + x**c*(a + b) + + However if you incorporate rationals to the exponents, then you will get + well known behavior:: + + >>> collect(a*x**(2*c) + b*x**(2*c), x**c) + x**(2*c)*(a + b) + + Note also that all previously stated facts about :func:`collect` function + apply to the exponential function, so you can get:: + + >>> from sympy import exp + >>> collect(a*exp(2*x) + b*exp(2*x), exp(x)) + (a + b)*exp(2*x) + + If you are interested only in collecting specific powers of some symbols + then set ``exact`` flag to True:: + + >>> collect(a*x**7 + b*x**7, x, exact=True) + a*x**7 + b*x**7 + >>> collect(a*x**7 + b*x**7, x**7, exact=True) + x**7*(a + b) + + If you want to collect on any object containing symbols, set + ``exact`` to None: + + >>> collect(x*exp(x) + sin(x)*y + sin(x)*2 + 3*x, x, exact=None) + x*exp(x) + 3*x + (y + 2)*sin(x) + >>> collect(a*x*y + x*y + b*x + x, [x, y], exact=None) + x*y*(a + 1) + x*(b + 1) + + You can also apply this function to differential equations, where + derivatives of arbitrary order can be collected. Note that if you + collect with respect to a function or a derivative of a function, all + derivatives of that function will also be collected. Use + ``exact=True`` to prevent this from happening:: + + >>> from sympy import Derivative as D, collect, Function + >>> f = Function('f') (x) + + >>> collect(a*D(f,x) + b*D(f,x), D(f,x)) + (a + b)*Derivative(f(x), x) + + >>> collect(a*D(D(f,x),x) + b*D(D(f,x),x), f) + (a + b)*Derivative(f(x), (x, 2)) + + >>> collect(a*D(D(f,x),x) + b*D(D(f,x),x), D(f,x), exact=True) + a*Derivative(f(x), (x, 2)) + b*Derivative(f(x), (x, 2)) + + >>> collect(a*D(f,x) + b*D(f,x) + a*f + b*f, f) + (a + b)*f(x) + (a + b)*Derivative(f(x), x) + + Or you can even match both derivative order and exponent at the same time:: + + >>> collect(a*D(D(f,x),x)**2 + b*D(D(f,x),x)**2, D(f,x)) + (a + b)*Derivative(f(x), (x, 2))**2 + + Finally, you can apply a function to each of the collected coefficients. + For example you can factorize symbolic coefficients of polynomial:: + + >>> f = expand((x + a + 1)**3) + + >>> collect(f, x, factor) + x**3 + 3*x**2*(a + 1) + 3*x*(a + 1)**2 + (a + 1)**3 + + .. note:: Arguments are expected to be in expanded form, so you might have + to call :func:`~.expand` prior to calling this function. + + See Also + ======== + + collect_const, collect_sqrt, rcollect + """ + expr = sympify(expr) + syms = [sympify(i) for i in (syms if iterable(syms) else [syms])] + + # replace syms[i] if it is not x, -x or has Wild symbols + cond = lambda x: x.is_Symbol or (-x).is_Symbol or bool( + x.atoms(Wild)) + _, nonsyms = sift(syms, cond, binary=True) + if nonsyms: + reps = dict(zip(nonsyms, [Dummy(**assumptions(i)) for i in nonsyms])) + syms = [reps.get(s, s) for s in syms] + rv = collect(expr.subs(reps), syms, + func=func, evaluate=evaluate, exact=exact, + distribute_order_term=distribute_order_term) + urep = {v: k for k, v in reps.items()} + if not isinstance(rv, dict): + return rv.xreplace(urep) + else: + return {urep.get(k, k).xreplace(urep): v.xreplace(urep) + for k, v in rv.items()} + + # see if other expressions should be considered + if exact is None: + _syms = set() + for i in Add.make_args(expr): + if not i.has_free(*syms) or i in syms: + continue + if not i.is_Mul and i not in syms: + _syms.add(i) + else: + # identify compound generators + g = i._new_rawargs(*i.as_coeff_mul(*syms)[1]) + if g not in syms: + _syms.add(g) + simple = all(i.is_Pow and i.base in syms for i in _syms) + syms = syms + list(ordered(_syms)) + if not simple: + return collect(expr, syms, + func=func, evaluate=evaluate, exact=False, + distribute_order_term=distribute_order_term) + + if evaluate is None: + evaluate = global_parameters.evaluate + + def make_expression(terms): + product = [] + + for term, rat, sym, deriv in terms: + if deriv is not None: + var, order = deriv + for _ in range(order): + term = Derivative(term, var) + + if sym is None: + if rat is S.One: + product.append(term) + else: + product.append(Pow(term, rat)) + else: + product.append(Pow(term, rat*sym)) + + return Mul(*product) + + def parse_derivative(deriv): + # scan derivatives tower in the input expression and return + # underlying function and maximal differentiation order + expr, sym, order = deriv.expr, deriv.variables[0], 1 + + for s in deriv.variables[1:]: + if s == sym: + order += 1 + else: + raise NotImplementedError( + 'Improve MV Derivative support in collect') + + while isinstance(expr, Derivative): + s0 = expr.variables[0] + + if any(s != s0 for s in expr.variables): + raise NotImplementedError( + 'Improve MV Derivative support in collect') + + if s0 == sym: + expr, order = expr.expr, order + len(expr.variables) + else: + break + + return expr, (sym, Rational(order)) + + def parse_term(expr): + """Parses expression expr and outputs tuple (sexpr, rat_expo, + sym_expo, deriv) + where: + - sexpr is the base expression + - rat_expo is the rational exponent that sexpr is raised to + - sym_expo is the symbolic exponent that sexpr is raised to + - deriv contains the derivatives of the expression + + For example, the output of x would be (x, 1, None, None) + the output of 2**x would be (2, 1, x, None). + """ + rat_expo, sym_expo = S.One, None + sexpr, deriv = expr, None + + if expr.is_Pow: + if isinstance(expr.base, Derivative): + sexpr, deriv = parse_derivative(expr.base) + else: + sexpr = expr.base + + if expr.base == S.Exp1: + arg = expr.exp + if arg.is_Rational: + sexpr, rat_expo = S.Exp1, arg + elif arg.is_Mul: + coeff, tail = arg.as_coeff_Mul(rational=True) + sexpr, rat_expo = exp(tail), coeff + + elif expr.exp.is_Number: + rat_expo = expr.exp + else: + coeff, tail = expr.exp.as_coeff_Mul() + + if coeff.is_Number: + rat_expo, sym_expo = coeff, tail + else: + sym_expo = expr.exp + elif isinstance(expr, exp): + arg = expr.exp + if arg.is_Rational: + sexpr, rat_expo = S.Exp1, arg + elif arg.is_Mul: + coeff, tail = arg.as_coeff_Mul(rational=True) + sexpr, rat_expo = exp(tail), coeff + elif isinstance(expr, Derivative): + sexpr, deriv = parse_derivative(expr) + + return sexpr, rat_expo, sym_expo, deriv + + def parse_expression(terms, pattern): + """Parse terms searching for a pattern. + Terms is a list of tuples as returned by parse_terms; + Pattern is an expression treated as a product of factors. + """ + pattern = Mul.make_args(pattern) + + if len(terms) < len(pattern): + # pattern is longer than matched product + # so no chance for positive parsing result + return None + else: + pattern = [parse_term(elem) for elem in pattern] + + terms = terms[:] # need a copy + elems, common_expo, has_deriv = [], None, False + + for elem, e_rat, e_sym, e_ord in pattern: + + if elem.is_Number and e_rat == 1 and e_sym is None: + # a constant is a match for everything + continue + + for j in range(len(terms)): + if terms[j] is None: + continue + + term, t_rat, t_sym, t_ord = terms[j] + + # keeping track of whether one of the terms had + # a derivative or not as this will require rebuilding + # the expression later + if t_ord is not None: + has_deriv = True + + if (term.match(elem) is not None and + (t_sym == e_sym or t_sym is not None and + e_sym is not None and + t_sym.match(e_sym) is not None)): + if exact is False: + # we don't have to be exact so find common exponent + # for both expression's term and pattern's element + expo = t_rat / e_rat + + if common_expo is None: + # first time + common_expo = expo + else: + # common exponent was negotiated before so + # there is no chance for a pattern match unless + # common and current exponents are equal + if common_expo != expo: + common_expo = 1 + else: + # we ought to be exact so all fields of + # interest must match in every details + if e_rat != t_rat or e_ord != t_ord: + continue + + # found common term so remove it from the expression + # and try to match next element in the pattern + elems.append(terms[j]) + terms[j] = None + + break + + else: + # pattern element not found + return None + + return [_f for _f in terms if _f], elems, common_expo, has_deriv + + if evaluate: + if expr.is_Add: + o = expr.getO() or 0 + expr = expr.func(*[ + collect(a, syms, func, True, exact, distribute_order_term) + for a in expr.args if a != o]) + o + elif expr.is_Mul: + return expr.func(*[ + collect(term, syms, func, True, exact, distribute_order_term) + for term in expr.args]) + elif expr.is_Pow: + b = collect( + expr.base, syms, func, True, exact, distribute_order_term) + return Pow(b, expr.exp) + + syms = [expand_power_base(i, deep=False) for i in syms] + + order_term = None + + if distribute_order_term: + order_term = expr.getO() + + if order_term is not None: + if order_term.has(*syms): + order_term = None + else: + expr = expr.removeO() + + summa = [expand_power_base(i, deep=False) for i in Add.make_args(expr)] + + collected, disliked = defaultdict(list), S.Zero + for product in summa: + c, nc = product.args_cnc(split_1=False) + args = list(ordered(c)) + nc + terms = [parse_term(i) for i in args] + small_first = True + + for symbol in syms: + if isinstance(symbol, Derivative) and small_first: + terms = list(reversed(terms)) + small_first = not small_first + result = parse_expression(terms, symbol) + + if result is not None: + if not symbol.is_commutative: + raise AttributeError("Can not collect noncommutative symbol") + + terms, elems, common_expo, has_deriv = result + + # when there was derivative in current pattern we + # will need to rebuild its expression from scratch + if not has_deriv: + margs = [] + for elem in elems: + if elem[2] is None: + e = elem[1] + else: + e = elem[1]*elem[2] + margs.append(Pow(elem[0], e)) + index = Mul(*margs) + else: + index = make_expression(elems) + terms = expand_power_base(make_expression(terms), deep=False) + index = expand_power_base(index, deep=False) + collected[index].append(terms) + break + else: + # none of the patterns matched + disliked += product + # add terms now for each key + collected = {k: Add(*v) for k, v in collected.items()} + + if disliked is not S.Zero: + collected[S.One] = disliked + + if order_term is not None: + for key, val in collected.items(): + collected[key] = val + order_term + + if func is not None: + collected = { + key: func(val) for key, val in collected.items()} + + if evaluate: + return Add(*[key*val for key, val in collected.items()]) + else: + return collected + + +def rcollect(expr, *vars): + """ + Recursively collect sums in an expression. + + Examples + ======== + + >>> from sympy.simplify import rcollect + >>> from sympy.abc import x, y + + >>> expr = (x**2*y + x*y + x + y)/(x + y) + + >>> rcollect(expr, y) + (x + y*(x**2 + x + 1))/(x + y) + + See Also + ======== + + collect, collect_const, collect_sqrt + """ + if expr.is_Atom or not expr.has(*vars): + return expr + else: + expr = expr.__class__(*[rcollect(arg, *vars) for arg in expr.args]) + + if expr.is_Add: + return collect(expr, vars) + else: + return expr + + +def collect_sqrt(expr, evaluate=None): + """Return expr with terms having common square roots collected together. + If ``evaluate`` is False a count indicating the number of sqrt-containing + terms will be returned and, if non-zero, the terms of the Add will be + returned, else the expression itself will be returned as a single term. + If ``evaluate`` is True, the expression with any collected terms will be + returned. + + Note: since I = sqrt(-1), it is collected, too. + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.simplify.radsimp import collect_sqrt + >>> from sympy.abc import a, b + + >>> r2, r3, r5 = [sqrt(i) for i in [2, 3, 5]] + >>> collect_sqrt(a*r2 + b*r2) + sqrt(2)*(a + b) + >>> collect_sqrt(a*r2 + b*r2 + a*r3 + b*r3) + sqrt(2)*(a + b) + sqrt(3)*(a + b) + >>> collect_sqrt(a*r2 + b*r2 + a*r3 + b*r5) + sqrt(3)*a + sqrt(5)*b + sqrt(2)*(a + b) + + If evaluate is False then the arguments will be sorted and + returned as a list and a count of the number of sqrt-containing + terms will be returned: + + >>> collect_sqrt(a*r2 + b*r2 + a*r3 + b*r5, evaluate=False) + ((sqrt(3)*a, sqrt(5)*b, sqrt(2)*(a + b)), 3) + >>> collect_sqrt(a*sqrt(2) + b, evaluate=False) + ((b, sqrt(2)*a), 1) + >>> collect_sqrt(a + b, evaluate=False) + ((a + b,), 0) + + See Also + ======== + + collect, collect_const, rcollect + """ + if evaluate is None: + evaluate = global_parameters.evaluate + # this step will help to standardize any complex arguments + # of sqrts + coeff, expr = expr.as_content_primitive() + vars = set() + for a in Add.make_args(expr): + for m in a.args_cnc()[0]: + if m.is_number and ( + m.is_Pow and m.exp.is_Rational and m.exp.q == 2 or + m is S.ImaginaryUnit): + vars.add(m) + + # we only want radicals, so exclude Number handling; in this case + # d will be evaluated + d = collect_const(expr, *vars, Numbers=False) + hit = expr != d + + if not evaluate: + nrad = 0 + # make the evaluated args canonical + args = list(ordered(Add.make_args(d))) + for i, m in enumerate(args): + c, nc = m.args_cnc() + for ci in c: + # XXX should this be restricted to ci.is_number as above? + if ci.is_Pow and ci.exp.is_Rational and ci.exp.q == 2 or \ + ci is S.ImaginaryUnit: + nrad += 1 + break + args[i] *= coeff + if not (hit or nrad): + args = [Add(*args)] + return tuple(args), nrad + + return coeff*d + + +def collect_abs(expr): + """Return ``expr`` with arguments of multiple Abs in a term collected + under a single instance. + + Examples + ======== + + >>> from sympy.simplify.radsimp import collect_abs + >>> from sympy.abc import x + >>> collect_abs(abs(x + 1)/abs(x**2 - 1)) + Abs((x + 1)/(x**2 - 1)) + >>> collect_abs(abs(1/x)) + Abs(1/x) + """ + def _abs(mul): + c, nc = mul.args_cnc() + a = [] + o = [] + for i in c: + if isinstance(i, Abs): + a.append(i.args[0]) + elif isinstance(i, Pow) and isinstance(i.base, Abs) and i.exp.is_real: + a.append(i.base.args[0]**i.exp) + else: + o.append(i) + if len(a) < 2 and not any(i.exp.is_negative for i in a if isinstance(i, Pow)): + return mul + absarg = Mul(*a) + A = Abs(absarg) + args = [A] + args.extend(o) + if not A.has(Abs): + args.extend(nc) + return Mul(*args) + if not isinstance(A, Abs): + # reevaluate and make it unevaluated + A = Abs(absarg, evaluate=False) + args[0] = A + _mulsort(args) + args.extend(nc) # nc always go last + return Mul._from_args(args, is_commutative=not nc) + + return expr.replace( + lambda x: isinstance(x, Mul), + lambda x: _abs(x)).replace( + lambda x: isinstance(x, Pow), + lambda x: _abs(x)) + + +def collect_const(expr, *vars, Numbers=True): + """A non-greedy collection of terms with similar number coefficients in + an Add expr. If ``vars`` is given then only those constants will be + targeted. Although any Number can also be targeted, if this is not + desired set ``Numbers=False`` and no Float or Rational will be collected. + + Parameters + ========== + + expr : SymPy expression + This parameter defines the expression the expression from which + terms with similar coefficients are to be collected. A non-Add + expression is returned as it is. + + vars : variable length collection of Numbers, optional + Specifies the constants to target for collection. Can be multiple in + number. + + Numbers : bool + Specifies to target all instance of + :class:`sympy.core.numbers.Number` class. If ``Numbers=False``, then + no Float or Rational will be collected. + + Returns + ======= + + expr : Expr + Returns an expression with similar coefficient terms collected. + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.abc import s, x, y, z + >>> from sympy.simplify.radsimp import collect_const + >>> collect_const(sqrt(3) + sqrt(3)*(1 + sqrt(2))) + sqrt(3)*(sqrt(2) + 2) + >>> collect_const(sqrt(3)*s + sqrt(7)*s + sqrt(3) + sqrt(7)) + (sqrt(3) + sqrt(7))*(s + 1) + >>> s = sqrt(2) + 2 + >>> collect_const(sqrt(3)*s + sqrt(3) + sqrt(7)*s + sqrt(7)) + (sqrt(2) + 3)*(sqrt(3) + sqrt(7)) + >>> collect_const(sqrt(3)*s + sqrt(3) + sqrt(7)*s + sqrt(7), sqrt(3)) + sqrt(7) + sqrt(3)*(sqrt(2) + 3) + sqrt(7)*(sqrt(2) + 2) + + The collection is sign-sensitive, giving higher precedence to the + unsigned values: + + >>> collect_const(x - y - z) + x - (y + z) + >>> collect_const(-y - z) + -(y + z) + >>> collect_const(2*x - 2*y - 2*z, 2) + 2*(x - y - z) + >>> collect_const(2*x - 2*y - 2*z, -2) + 2*x - 2*(y + z) + + See Also + ======== + + collect, collect_sqrt, rcollect + """ + if not expr.is_Add: + return expr + + recurse = False + + if not vars: + recurse = True + vars = set() + for a in expr.args: + for m in Mul.make_args(a): + if m.is_number: + vars.add(m) + else: + vars = sympify(vars) + if not Numbers: + vars = [v for v in vars if not v.is_Number] + + vars = list(ordered(vars)) + for v in vars: + terms = defaultdict(list) + Fv = Factors(v) + for m in Add.make_args(expr): + f = Factors(m) + q, r = f.div(Fv) + if r.is_one: + # only accept this as a true factor if + # it didn't change an exponent from an Integer + # to a non-Integer, e.g. 2/sqrt(2) -> sqrt(2) + # -- we aren't looking for this sort of change + fwas = f.factors.copy() + fnow = q.factors + if not any(k in fwas and fwas[k].is_Integer and not + fnow[k].is_Integer for k in fnow): + terms[v].append(q.as_expr()) + continue + terms[S.One].append(m) + + args = [] + hit = False + uneval = False + for k in ordered(terms): + v = terms[k] + if k is S.One: + args.extend(v) + continue + + if len(v) > 1: + v = Add(*v) + hit = True + if recurse and v != expr: + vars.append(v) + else: + v = v[0] + + # be careful not to let uneval become True unless + # it must be because it's going to be more expensive + # to rebuild the expression as an unevaluated one + if Numbers and k.is_Number and v.is_Add: + args.append(_keep_coeff(k, v, sign=True)) + uneval = True + else: + args.append(k*v) + + if hit: + if uneval: + expr = _unevaluated_Add(*args) + else: + expr = Add(*args) + if not expr.is_Add: + break + + return expr + + +def radsimp(expr, symbolic=True, max_terms=4): + r""" + Rationalize the denominator by removing square roots. + + Explanation + =========== + + The expression returned from radsimp must be used with caution + since if the denominator contains symbols, it will be possible to make + substitutions that violate the assumptions of the simplification process: + that for a denominator matching a + b*sqrt(c), a != +/-b*sqrt(c). (If + there are no symbols, this assumptions is made valid by collecting terms + of sqrt(c) so the match variable ``a`` does not contain ``sqrt(c)``.) If + you do not want the simplification to occur for symbolic denominators, set + ``symbolic`` to False. + + If there are more than ``max_terms`` radical terms then the expression is + returned unchanged. + + Examples + ======== + + >>> from sympy import radsimp, sqrt, Symbol, pprint + >>> from sympy import factor_terms, fraction, signsimp + >>> from sympy.simplify.radsimp import collect_sqrt + >>> from sympy.abc import a, b, c + + >>> radsimp(1/(2 + sqrt(2))) + (2 - sqrt(2))/2 + >>> x,y = map(Symbol, 'xy') + >>> e = ((2 + 2*sqrt(2))*x + (2 + sqrt(8))*y)/(2 + sqrt(2)) + >>> radsimp(e) + sqrt(2)*(x + y) + + No simplification beyond removal of the gcd is done. One might + want to polish the result a little, however, by collecting + square root terms: + + >>> r2 = sqrt(2) + >>> r5 = sqrt(5) + >>> ans = radsimp(1/(y*r2 + x*r2 + a*r5 + b*r5)); pprint(ans) + ___ ___ ___ ___ + \/ 5 *a + \/ 5 *b - \/ 2 *x - \/ 2 *y + ------------------------------------------ + 2 2 2 2 + 5*a + 10*a*b + 5*b - 2*x - 4*x*y - 2*y + + >>> n, d = fraction(ans) + >>> pprint(factor_terms(signsimp(collect_sqrt(n))/d, radical=True)) + ___ ___ + \/ 5 *(a + b) - \/ 2 *(x + y) + ------------------------------------------ + 2 2 2 2 + 5*a + 10*a*b + 5*b - 2*x - 4*x*y - 2*y + + If radicals in the denominator cannot be removed or there is no denominator, + the original expression will be returned. + + >>> radsimp(sqrt(2)*x + sqrt(2)) + sqrt(2)*x + sqrt(2) + + Results with symbols will not always be valid for all substitutions: + + >>> eq = 1/(a + b*sqrt(c)) + >>> eq.subs(a, b*sqrt(c)) + 1/(2*b*sqrt(c)) + >>> radsimp(eq).subs(a, b*sqrt(c)) + nan + + If ``symbolic=False``, symbolic denominators will not be transformed (but + numeric denominators will still be processed): + + >>> radsimp(eq, symbolic=False) + 1/(a + b*sqrt(c)) + + """ + from sympy.core.expr import Expr + from sympy.simplify.simplify import signsimp + + syms = symbols("a:d A:D") + def _num(rterms): + # return the multiplier that will simplify the expression described + # by rterms [(sqrt arg, coeff), ... ] + a, b, c, d, A, B, C, D = syms + if len(rterms) == 2: + reps = dict(list(zip([A, a, B, b], [j for i in rterms for j in i]))) + return ( + sqrt(A)*a - sqrt(B)*b).xreplace(reps) + if len(rterms) == 3: + reps = dict(list(zip([A, a, B, b, C, c], [j for i in rterms for j in i]))) + return ( + (sqrt(A)*a + sqrt(B)*b - sqrt(C)*c)*(2*sqrt(A)*sqrt(B)*a*b - A*a**2 - + B*b**2 + C*c**2)).xreplace(reps) + elif len(rterms) == 4: + reps = dict(list(zip([A, a, B, b, C, c, D, d], [j for i in rterms for j in i]))) + return ((sqrt(A)*a + sqrt(B)*b - sqrt(C)*c - sqrt(D)*d)*(2*sqrt(A)*sqrt(B)*a*b + - A*a**2 - B*b**2 - 2*sqrt(C)*sqrt(D)*c*d + C*c**2 + + D*d**2)*(-8*sqrt(A)*sqrt(B)*sqrt(C)*sqrt(D)*a*b*c*d + A**2*a**4 - + 2*A*B*a**2*b**2 - 2*A*C*a**2*c**2 - 2*A*D*a**2*d**2 + B**2*b**4 - + 2*B*C*b**2*c**2 - 2*B*D*b**2*d**2 + C**2*c**4 - 2*C*D*c**2*d**2 + + D**2*d**4)).xreplace(reps) + elif len(rterms) == 1: + return sqrt(rterms[0][0]) + else: + raise NotImplementedError + + def ispow2(d, log2=False): + if not d.is_Pow: + return False + e = d.exp + if e.is_Rational and e.q == 2 or symbolic and denom(e) == 2: + return True + if log2: + q = 1 + if e.is_Rational: + q = e.q + elif symbolic: + d = denom(e) + if d.is_Integer: + q = d + if q != 1 and log(q, 2).is_Integer: + return True + return False + + def handle(expr): + # Handle first reduces to the case + # expr = 1/d, where d is an add, or d is base**p/2. + # We do this by recursively calling handle on each piece. + from sympy.simplify.simplify import nsimplify + + if expr.is_Atom: + return expr + elif not isinstance(expr, Expr): + return expr.func(*[handle(a) for a in expr.args]) + + n, d = fraction(expr) + + if d.is_Atom and n.is_Atom: + return expr + elif not n.is_Atom: + n = n.func(*[handle(a) for a in n.args]) + return _unevaluated_Mul(n, handle(1/d)) + elif n is not S.One: + return _unevaluated_Mul(n, handle(1/d)) + elif d.is_Mul: + return _unevaluated_Mul(*[handle(1/d) for d in d.args]) + + # By this step, expr is 1/d, and d is not a mul. + if not symbolic and d.free_symbols: + return expr + + if ispow2(d): + d2 = sqrtdenest(sqrt(d.base))**numer(d.exp) + if d2 != d: + return handle(1/d2) + elif d.is_Pow and (d.exp.is_integer or d.base.is_positive): + # (1/d**i) = (1/d)**i + return handle(1/d.base)**d.exp + + if not (d.is_Add or ispow2(d)): + return 1/d.func(*[handle(a) for a in d.args]) + + # handle 1/d treating d as an Add (though it may not be) + + keep = True # keep changes that are made + + # flatten it and collect radicals after checking for special + # conditions + d = _mexpand(d) + + # did it change? + if d.is_Atom: + return 1/d + + # is it a number that might be handled easily? + if d.is_number: + _d = nsimplify(d) + if _d.is_Number and _d.equals(d): + return 1/_d + + while True: + # collect similar terms + collected = defaultdict(list) + for m in Add.make_args(d): # d might have become non-Add + p2 = [] + other = [] + for i in Mul.make_args(m): + if ispow2(i, log2=True): + p2.append(i.base if i.exp is S.Half else i.base**(2*i.exp)) + elif i is S.ImaginaryUnit: + p2.append(S.NegativeOne) + else: + other.append(i) + collected[tuple(ordered(p2))].append(Mul(*other)) + rterms = list(ordered(list(collected.items()))) + rterms = [(Mul(*i), Add(*j)) for i, j in rterms] + nrad = len(rterms) - (1 if rterms[0][0] is S.One else 0) + if nrad < 1: + break + elif nrad > max_terms: + # there may have been invalid operations leading to this point + # so don't keep changes, e.g. this expression is troublesome + # in collecting terms so as not to raise the issue of 2834: + # r = sqrt(sqrt(5) + 5) + # eq = 1/(sqrt(5)*r + 2*sqrt(5)*sqrt(-sqrt(5) + 5) + 5*r) + keep = False + break + if len(rterms) > 4: + # in general, only 4 terms can be removed with repeated squaring + # but other considerations can guide selection of radical terms + # so that radicals are removed + if all(x.is_Integer and (y**2).is_Rational for x, y in rterms): + nd, d = rad_rationalize(S.One, Add._from_args( + [sqrt(x)*y for x, y in rterms])) + n *= nd + else: + # is there anything else that might be attempted? + keep = False + break + from sympy.simplify.powsimp import powsimp, powdenest + + num = powsimp(_num(rterms)) + n *= num + d *= num + d = powdenest(_mexpand(d), force=symbolic) + if d.has(S.Zero, nan, zoo): + return expr + if d.is_Atom: + break + + if not keep: + return expr + return _unevaluated_Mul(n, 1/d) + + if not isinstance(expr, Expr): + return expr.func(*[radsimp(a, symbolic=symbolic, max_terms=max_terms) for a in expr.args]) + + coeff, expr = expr.as_coeff_Add() + expr = expr.normal() + old = fraction(expr) + n, d = fraction(handle(expr)) + if old != (n, d): + if not d.is_Atom: + was = (n, d) + n = signsimp(n, evaluate=False) + d = signsimp(d, evaluate=False) + u = Factors(_unevaluated_Mul(n, 1/d)) + u = _unevaluated_Mul(*[k**v for k, v in u.factors.items()]) + n, d = fraction(u) + if old == (n, d): + n, d = was + n = expand_mul(n) + if d.is_Number or d.is_Add: + n2, d2 = fraction(gcd_terms(_unevaluated_Mul(n, 1/d))) + if d2.is_Number or (d2.count_ops() <= d.count_ops()): + n, d = [signsimp(i) for i in (n2, d2)] + if n.is_Mul and n.args[0].is_Number: + n = n.func(*n.args) + + return coeff + _unevaluated_Mul(n, 1/d) + + +def rad_rationalize(num, den): + """ + Rationalize ``num/den`` by removing square roots in the denominator; + num and den are sum of terms whose squares are positive rationals. + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.simplify.radsimp import rad_rationalize + >>> rad_rationalize(sqrt(3), 1 + sqrt(2)/3) + (-sqrt(3) + sqrt(6)/3, -7/9) + """ + if not den.is_Add: + return num, den + g, a, b = split_surds(den) + a = a*sqrt(g) + num = _mexpand((a - b)*num) + den = _mexpand(a**2 - b**2) + return rad_rationalize(num, den) + + +def fraction(expr, exact=False): + """Returns a pair with expression's numerator and denominator. + If the given expression is not a fraction then this function + will return the tuple (expr, 1). + + This function will not make any attempt to simplify nested + fractions or to do any term rewriting at all. + + If only one of the numerator/denominator pair is needed then + use numer(expr) or denom(expr) functions respectively. + + >>> from sympy import fraction, Rational, Symbol + >>> from sympy.abc import x, y + + >>> fraction(x/y) + (x, y) + >>> fraction(x) + (x, 1) + + >>> fraction(1/y**2) + (1, y**2) + + >>> fraction(x*y/2) + (x*y, 2) + >>> fraction(Rational(1, 2)) + (1, 2) + + This function will also work fine with assumptions: + + >>> k = Symbol('k', negative=True) + >>> fraction(x * y**k) + (x, y**(-k)) + + If we know nothing about sign of some exponent and ``exact`` + flag is unset, then the exponent's structure will + be analyzed and pretty fraction will be returned: + + >>> from sympy import exp, Mul + >>> fraction(2*x**(-y)) + (2, x**y) + + >>> fraction(exp(-x)) + (1, exp(x)) + + >>> fraction(exp(-x), exact=True) + (exp(-x), 1) + + The ``exact`` flag will also keep any unevaluated Muls from + being evaluated: + + >>> u = Mul(2, x + 1, evaluate=False) + >>> fraction(u) + (2*x + 2, 1) + >>> fraction(u, exact=True) + (2*(x + 1), 1) + """ + expr = sympify(expr) + + numer, denom = [], [] + + for term in Mul.make_args(expr): + if term.is_commutative and (term.is_Pow or isinstance(term, exp)): + b, ex = term.as_base_exp() + if ex.is_negative: + if ex is S.NegativeOne: + denom.append(b) + elif exact: + if ex.is_constant(): + denom.append(Pow(b, -ex)) + else: + numer.append(term) + else: + denom.append(Pow(b, -ex)) + elif ex.is_positive: + numer.append(term) + elif not exact and ex.is_Mul: + n, d = term.as_numer_denom() # this will cause evaluation + if n != 1: + numer.append(n) + denom.append(d) + else: + numer.append(term) + elif term.is_Rational and not term.is_Integer: + if term.p != 1: + numer.append(term.p) + denom.append(term.q) + else: + numer.append(term) + return Mul(*numer, evaluate=not exact), Mul(*denom, evaluate=not exact) + + +def numer(expr, exact=False): # default matches fraction's default + return fraction(expr, exact=exact)[0] + + +def denom(expr, exact=False): # default matches fraction's default + return fraction(expr, exact=exact)[1] + + +def fraction_expand(expr, **hints): + return expr.expand(frac=True, **hints) + + +def numer_expand(expr, **hints): + # default matches fraction's default + a, b = fraction(expr, exact=hints.get('exact', False)) + return a.expand(numer=True, **hints) / b + + +def denom_expand(expr, **hints): + # default matches fraction's default + a, b = fraction(expr, exact=hints.get('exact', False)) + return a / b.expand(denom=True, **hints) + + +expand_numer = numer_expand +expand_denom = denom_expand +expand_fraction = fraction_expand + + +def split_surds(expr): + """ + Split an expression with terms whose squares are positive rationals + into a sum of terms whose surds squared have gcd equal to g + and a sum of terms with surds squared prime with g. + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.simplify.radsimp import split_surds + >>> split_surds(3*sqrt(3) + sqrt(5)/7 + sqrt(6) + sqrt(10) + sqrt(15)) + (3, sqrt(2) + sqrt(5) + 3, sqrt(5)/7 + sqrt(10)) + """ + args = sorted(expr.args, key=default_sort_key) + coeff_muls = [x.as_coeff_Mul() for x in args] + surds = [x[1]**2 for x in coeff_muls if x[1].is_Pow] + surds.sort(key=default_sort_key) + g, b1, b2 = _split_gcd(*surds) + g2 = g + if not b2 and len(b1) >= 2: + b1n = [x/g for x in b1] + b1n = [x for x in b1n if x != 1] + # only a common factor has been factored; split again + g1, b1n, b2 = _split_gcd(*b1n) + g2 = g*g1 + a1v, a2v = [], [] + for c, s in coeff_muls: + if s.is_Pow and s.exp == S.Half: + s1 = s.base + if s1 in b1: + a1v.append(c*sqrt(s1/g2)) + else: + a2v.append(c*s) + else: + a2v.append(c*s) + a = Add(*a1v) + b = Add(*a2v) + return g2, a, b + + +def _split_gcd(*a): + """ + Split the list of integers ``a`` into a list of integers, ``a1`` having + ``g = gcd(a1)``, and a list ``a2`` whose elements are not divisible by + ``g``. Returns ``g, a1, a2``. + + Examples + ======== + + >>> from sympy.simplify.radsimp import _split_gcd + >>> _split_gcd(55, 35, 22, 14, 77, 10) + (5, [55, 35, 10], [22, 14, 77]) + """ + g = a[0] + b1 = [g] + b2 = [] + for x in a[1:]: + g1 = gcd(g, x) + if g1 == 1: + b2.append(x) + else: + g = g1 + b1.append(x) + return g, b1, b2 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/ratsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/ratsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..95751fab47f585d3ae2e1289f014fba0f2708224 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/ratsimp.py @@ -0,0 +1,222 @@ +from itertools import combinations_with_replacement +from sympy.core import symbols, Add, Dummy +from sympy.core.numbers import Rational +from sympy.polys import cancel, ComputationFailed, parallel_poly_from_expr, reduced, Poly +from sympy.polys.monomials import Monomial, monomial_div +from sympy.polys.polyerrors import DomainError, PolificationFailed +from sympy.utilities.misc import debug, debugf + +def ratsimp(expr): + """ + Put an expression over a common denominator, cancel and reduce. + + Examples + ======== + + >>> from sympy import ratsimp + >>> from sympy.abc import x, y + >>> ratsimp(1/x + 1/y) + (x + y)/(x*y) + """ + + f, g = cancel(expr).as_numer_denom() + try: + Q, r = reduced(f, [g], field=True, expand=False) + except ComputationFailed: + return f/g + + return Add(*Q) + cancel(r/g) + + +def ratsimpmodprime(expr, G, *gens, quick=True, polynomial=False, **args): + """ + Simplifies a rational expression ``expr`` modulo the prime ideal + generated by ``G``. ``G`` should be a Groebner basis of the + ideal. + + Examples + ======== + + >>> from sympy.simplify.ratsimp import ratsimpmodprime + >>> from sympy.abc import x, y + >>> eq = (x + y**5 + y)/(x - y) + >>> ratsimpmodprime(eq, [x*y**5 - x - y], x, y, order='lex') + (-x**2 - x*y - x - y)/(-x**2 + x*y) + + If ``polynomial`` is ``False``, the algorithm computes a rational + simplification which minimizes the sum of the total degrees of + the numerator and the denominator. + + If ``polynomial`` is ``True``, this function just brings numerator and + denominator into a canonical form. This is much faster, but has + potentially worse results. + + References + ========== + + .. [1] M. Monagan, R. Pearce, Rational Simplification Modulo a Polynomial + Ideal, https://dl.acm.org/doi/pdf/10.1145/1145768.1145809 + (specifically, the second algorithm) + """ + from sympy.solvers.solvers import solve + + debug('ratsimpmodprime', expr) + + # usual preparation of polynomials: + + num, denom = cancel(expr).as_numer_denom() + + try: + polys, opt = parallel_poly_from_expr([num, denom] + G, *gens, **args) + except PolificationFailed: + return expr + + domain = opt.domain + + if domain.has_assoc_Field: + opt.domain = domain.get_field() + else: + raise DomainError( + "Cannot compute rational simplification over %s" % domain) + + # compute only once + leading_monomials = [g.LM(opt.order) for g in polys[2:]] + tested = set() + + def staircase(n): + """ + Compute all monomials with degree less than ``n`` that are + not divisible by any element of ``leading_monomials``. + """ + if n == 0: + return [1] + S = [] + for mi in combinations_with_replacement(range(len(opt.gens)), n): + m = [0]*len(opt.gens) + for i in mi: + m[i] += 1 + if all(monomial_div(m, lmg) is None for lmg in + leading_monomials): + S.append(m) + + return [Monomial(s).as_expr(*opt.gens) for s in S] + staircase(n - 1) + + def _ratsimpmodprime(a, b, allsol, N=0, D=0): + r""" + Computes a rational simplification of ``a/b`` which minimizes + the sum of the total degrees of the numerator and the denominator. + + Explanation + =========== + + The algorithm proceeds by looking at ``a * d - b * c`` modulo + the ideal generated by ``G`` for some ``c`` and ``d`` with degree + less than ``a`` and ``b`` respectively. + The coefficients of ``c`` and ``d`` are indeterminates and thus + the coefficients of the normalform of ``a * d - b * c`` are + linear polynomials in these indeterminates. + If these linear polynomials, considered as system of + equations, have a nontrivial solution, then `\frac{a}{b} + \equiv \frac{c}{d}` modulo the ideal generated by ``G``. So, + by construction, the degree of ``c`` and ``d`` is less than + the degree of ``a`` and ``b``, so a simpler representation + has been found. + After a simpler representation has been found, the algorithm + tries to reduce the degree of the numerator and denominator + and returns the result afterwards. + + As an extension, if quick=False, we look at all possible degrees such + that the total degree is less than *or equal to* the best current + solution. We retain a list of all solutions of minimal degree, and try + to find the best one at the end. + """ + c, d = a, b + steps = 0 + + maxdeg = a.total_degree() + b.total_degree() + if quick: + bound = maxdeg - 1 + else: + bound = maxdeg + while N + D <= bound: + if (N, D) in tested: + break + tested.add((N, D)) + + M1 = staircase(N) + M2 = staircase(D) + debugf('%s / %s: %s, %s', (N, D, M1, M2)) + + Cs = symbols("c:%d" % len(M1), cls=Dummy) + Ds = symbols("d:%d" % len(M2), cls=Dummy) + ng = Cs + Ds + + c_hat = Poly( + sum(Cs[i] * M1[i] for i in range(len(M1))), opt.gens + ng) + d_hat = Poly( + sum(Ds[i] * M2[i] for i in range(len(M2))), opt.gens + ng) + + r = reduced(a * d_hat - b * c_hat, G, opt.gens + ng, + order=opt.order, polys=True)[1] + + S = Poly(r, gens=opt.gens).coeffs() + sol = solve(S, Cs + Ds, particular=True, quick=True) + + if sol and not all(s == 0 for s in sol.values()): + c = c_hat.subs(sol) + d = d_hat.subs(sol) + + # The "free" variables occurring before as parameters + # might still be in the substituted c, d, so set them + # to the value chosen before: + c = c.subs(dict(list(zip(Cs + Ds, [1] * (len(Cs) + len(Ds)))))) + d = d.subs(dict(list(zip(Cs + Ds, [1] * (len(Cs) + len(Ds)))))) + + c = Poly(c, opt.gens) + d = Poly(d, opt.gens) + if d == 0: + raise ValueError('Ideal not prime?') + + allsol.append((c_hat, d_hat, S, Cs + Ds)) + if N + D != maxdeg: + allsol = [allsol[-1]] + + break + + steps += 1 + N += 1 + D += 1 + + if steps > 0: + c, d, allsol = _ratsimpmodprime(c, d, allsol, N, D - steps) + c, d, allsol = _ratsimpmodprime(c, d, allsol, N - steps, D) + + return c, d, allsol + + # preprocessing. this improves performance a bit when deg(num) + # and deg(denom) are large: + num = reduced(num, G, opt.gens, order=opt.order)[1] + denom = reduced(denom, G, opt.gens, order=opt.order)[1] + + if polynomial: + return (num/denom).cancel() + + c, d, allsol = _ratsimpmodprime( + Poly(num, opt.gens, domain=opt.domain), Poly(denom, opt.gens, domain=opt.domain), []) + if not quick and allsol: + debugf('Looking for best minimal solution. Got: %s', len(allsol)) + newsol = [] + for c_hat, d_hat, S, ng in allsol: + sol = solve(S, ng, particular=True, quick=False) + # all values of sol should be numbers; if not, solve is broken + newsol.append((c_hat.subs(sol), d_hat.subs(sol))) + c, d = min(newsol, key=lambda x: len(x[0].terms()) + len(x[1].terms())) + + if not domain.is_Field: + cn, c = c.clear_denoms(convert=True) + dn, d = d.clear_denoms(convert=True) + r = Rational(cn, dn) + else: + r = Rational(1) + + return (c*r.q)/(d*r.p) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/simplify.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/simplify.py new file mode 100644 index 0000000000000000000000000000000000000000..8b315cc20c19fc10c37b903d16129a7f5579ecd3 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/simplify.py @@ -0,0 +1,2164 @@ +from __future__ import annotations + +from typing import overload + +from collections import defaultdict + +from sympy.concrete.products import Product +from sympy.concrete.summations import Sum +from sympy.core import (Basic, S, Add, Mul, Pow, Symbol, sympify, + expand_func, Function, Dummy, Expr, factor_terms, + expand_power_exp, Eq) +from sympy.core.exprtools import factor_nc +from sympy.core.parameters import global_parameters +from sympy.core.function import (expand_log, count_ops, _mexpand, + nfloat, expand_mul, expand) +from sympy.core.numbers import Float, I, pi, Rational, equal_valued +from sympy.core.relational import Relational +from sympy.core.rules import Transform +from sympy.core.sorting import ordered +from sympy.core.sympify import _sympify +from sympy.core.traversal import bottom_up as _bottom_up, walk as _walk +from sympy.functions import gamma, exp, sqrt, log, exp_polar, re +from sympy.functions.combinatorial.factorials import CombinatorialFunction +from sympy.functions.elementary.complexes import unpolarify, Abs, sign +from sympy.functions.elementary.exponential import ExpBase +from sympy.functions.elementary.hyperbolic import HyperbolicFunction +from sympy.functions.elementary.integers import ceiling +from sympy.functions.elementary.piecewise import (Piecewise, piecewise_fold, + piecewise_simplify) +from sympy.functions.elementary.trigonometric import TrigonometricFunction +from sympy.functions.special.bessel import (BesselBase, besselj, besseli, + besselk, bessely, jn) +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.integrals.integrals import Integral +from sympy.logic.boolalg import Boolean +from sympy.matrices.expressions import (MatrixExpr, MatAdd, MatMul, + MatPow, MatrixSymbol) +from sympy.polys import together, cancel, factor +from sympy.polys.numberfields.minpoly import _is_sum_surds, _minimal_polynomial_sq +from sympy.sets.sets import Set +from sympy.simplify.combsimp import combsimp +from sympy.simplify.cse_opts import sub_pre, sub_post +from sympy.simplify.hyperexpand import hyperexpand +from sympy.simplify.powsimp import powsimp +from sympy.simplify.radsimp import radsimp, fraction, collect_abs +from sympy.simplify.sqrtdenest import sqrtdenest +from sympy.simplify.trigsimp import trigsimp, exptrigsimp +from sympy.utilities.decorator import deprecated +from sympy.utilities.iterables import has_variety, sift, subsets, iterable +from sympy.utilities.misc import as_int + +import mpmath + + +def separatevars(expr, symbols=[], dict=False, force=False): + """ + Separates variables in an expression, if possible. By + default, it separates with respect to all symbols in an + expression and collects constant coefficients that are + independent of symbols. + + Explanation + =========== + + If ``dict=True`` then the separated terms will be returned + in a dictionary keyed to their corresponding symbols. + By default, all symbols in the expression will appear as + keys; if symbols are provided, then all those symbols will + be used as keys, and any terms in the expression containing + other symbols or non-symbols will be returned keyed to the + string 'coeff'. (Passing None for symbols will return the + expression in a dictionary keyed to 'coeff'.) + + If ``force=True``, then bases of powers will be separated regardless + of assumptions on the symbols involved. + + Notes + ===== + + The order of the factors is determined by Mul, so that the + separated expressions may not necessarily be grouped together. + + Although factoring is necessary to separate variables in some + expressions, it is not necessary in all cases, so one should not + count on the returned factors being factored. + + Examples + ======== + + >>> from sympy.abc import x, y, z, alpha + >>> from sympy import separatevars, sin + >>> separatevars((x*y)**y) + (x*y)**y + >>> separatevars((x*y)**y, force=True) + x**y*y**y + + >>> e = 2*x**2*z*sin(y)+2*z*x**2 + >>> separatevars(e) + 2*x**2*z*(sin(y) + 1) + >>> separatevars(e, symbols=(x, y), dict=True) + {'coeff': 2*z, x: x**2, y: sin(y) + 1} + >>> separatevars(e, [x, y, alpha], dict=True) + {'coeff': 2*z, alpha: 1, x: x**2, y: sin(y) + 1} + + If the expression is not really separable, or is only partially + separable, separatevars will do the best it can to separate it + by using factoring. + + >>> separatevars(x + x*y - 3*x**2) + -x*(3*x - y - 1) + + If the expression is not separable then expr is returned unchanged + or (if dict=True) then None is returned. + + >>> eq = 2*x + y*sin(x) + >>> separatevars(eq) == eq + True + >>> separatevars(2*x + y*sin(x), symbols=(x, y), dict=True) is None + True + + """ + expr = sympify(expr) + if dict: + return _separatevars_dict(_separatevars(expr, force), symbols) + else: + return _separatevars(expr, force) + + +def _separatevars(expr, force): + if isinstance(expr, Abs): + arg = expr.args[0] + if arg.is_Mul and not arg.is_number: + s = separatevars(arg, dict=True, force=force) + if s is not None: + return Mul(*map(expr.func, s.values())) + else: + return expr + + if len(expr.free_symbols) < 2: + return expr + + # don't destroy a Mul since much of the work may already be done + if expr.is_Mul: + args = list(expr.args) + changed = False + for i, a in enumerate(args): + args[i] = separatevars(a, force) + changed = changed or args[i] != a + if changed: + expr = expr.func(*args) + return expr + + # get a Pow ready for expansion + if expr.is_Pow and expr.base != S.Exp1: + expr = Pow(separatevars(expr.base, force=force), expr.exp) + + # First try other expansion methods + expr = expr.expand(mul=False, multinomial=False, force=force) + + _expr, reps = posify(expr) if force else (expr, {}) + expr = factor(_expr).subs(reps) + + if not expr.is_Add: + return expr + + # Find any common coefficients to pull out + args = list(expr.args) + commonc = args[0].args_cnc(cset=True, warn=False)[0] + for i in args[1:]: + commonc &= i.args_cnc(cset=True, warn=False)[0] + commonc = Mul(*commonc) + commonc = commonc.as_coeff_Mul()[1] # ignore constants + commonc_set = commonc.args_cnc(cset=True, warn=False)[0] + + # remove them + for i, a in enumerate(args): + c, nc = a.args_cnc(cset=True, warn=False) + c = c - commonc_set + args[i] = Mul(*c)*Mul(*nc) + nonsepar = Add(*args) + + if len(nonsepar.free_symbols) > 1: + _expr = nonsepar + _expr, reps = posify(_expr) if force else (_expr, {}) + _expr = (factor(_expr)).subs(reps) + + if not _expr.is_Add: + nonsepar = _expr + + return commonc*nonsepar + + +def _separatevars_dict(expr, symbols): + if symbols: + if not all(t.is_Atom for t in symbols): + raise ValueError("symbols must be Atoms.") + symbols = list(symbols) + elif symbols is None: + return {'coeff': expr} + else: + symbols = list(expr.free_symbols) + if not symbols: + return None + + ret = {i: [] for i in symbols + ['coeff']} + + for i in Mul.make_args(expr): + expsym = i.free_symbols + intersection = set(symbols).intersection(expsym) + if len(intersection) > 1: + return None + if len(intersection) == 0: + # There are no symbols, so it is part of the coefficient + ret['coeff'].append(i) + else: + ret[intersection.pop()].append(i) + + # rebuild + for k, v in ret.items(): + ret[k] = Mul(*v) + + return ret + + +def posify(eq): + """Return ``eq`` (with generic symbols made positive) and a + dictionary containing the mapping between the old and new + symbols. + + Explanation + =========== + + Any symbol that has positive=None will be replaced with a positive dummy + symbol having the same name. This replacement will allow more symbolic + processing of expressions, especially those involving powers and + logarithms. + + A dictionary that can be sent to subs to restore ``eq`` to its original + symbols is also returned. + + >>> from sympy import posify, Symbol, log, solve + >>> from sympy.abc import x + >>> posify(x + Symbol('p', positive=True) + Symbol('n', negative=True)) + (_x + n + p, {_x: x}) + + >>> eq = 1/x + >>> log(eq).expand() + log(1/x) + >>> log(posify(eq)[0]).expand() + -log(_x) + >>> p, rep = posify(eq) + >>> log(p).expand().subs(rep) + -log(x) + + It is possible to apply the same transformations to an iterable + of expressions: + + >>> eq = x**2 - 4 + >>> solve(eq, x) + [-2, 2] + >>> eq_x, reps = posify([eq, x]); eq_x + [_x**2 - 4, _x] + >>> solve(*eq_x) + [2] + """ + eq = sympify(eq) + if not isinstance(eq, Basic) and iterable(eq): + f = type(eq) + eq = list(eq) + syms = set() + for e in eq: + syms = syms.union(e.atoms(Symbol)) + reps = {} + for s in syms: + reps.update({v: k for k, v in posify(s)[1].items()}) + for i, e in enumerate(eq): + eq[i] = e.subs(reps) + return f(eq), {r: s for s, r in reps.items()} + + reps = {s: Dummy(s.name, positive=True, **s.assumptions0) + for s in eq.free_symbols if s.is_positive is None} + eq = eq.subs(reps) + return eq, {r: s for s, r in reps.items()} + + +def hypersimp(f, k): + """Given combinatorial term f(k) simplify its consecutive term ratio + i.e. f(k+1)/f(k). The input term can be composed of functions and + integer sequences which have equivalent representation in terms + of gamma special function. + + Explanation + =========== + + The algorithm performs three basic steps: + + 1. Rewrite all functions in terms of gamma, if possible. + + 2. Rewrite all occurrences of gamma in terms of products + of gamma and rising factorial with integer, absolute + constant exponent. + + 3. Perform simplification of nested fractions, powers + and if the resulting expression is a quotient of + polynomials, reduce their total degree. + + If f(k) is hypergeometric then as result we arrive with a + quotient of polynomials of minimal degree. Otherwise None + is returned. + + For more information on the implemented algorithm refer to: + + 1. W. Koepf, Algorithms for m-fold Hypergeometric Summation, + Journal of Symbolic Computation (1995) 20, 399-417 + """ + f = sympify(f) + + g = f.subs(k, k + 1) / f + + g = g.rewrite(gamma) + if g.has(Piecewise): + g = piecewise_fold(g) + g = g.args[-1][0] + g = expand_func(g) + g = powsimp(g, deep=True, combine='exp') + + if g.is_rational_function(k): + return simplify(g, ratio=S.Infinity) + else: + return None + + +def hypersimilar(f, g, k): + """ + Returns True if ``f`` and ``g`` are hyper-similar. + + Explanation + =========== + + Similarity in hypergeometric sense means that a quotient of + f(k) and g(k) is a rational function in ``k``. This procedure + is useful in solving recurrence relations. + + For more information see hypersimp(). + + """ + f, g = list(map(sympify, (f, g))) + + h = (f/g).rewrite(gamma) + h = h.expand(func=True, basic=False) + + return h.is_rational_function(k) + + +def signsimp(expr, evaluate=None): + """Make all Add sub-expressions canonical wrt sign. + + Explanation + =========== + + If an Add subexpression, ``a``, can have a sign extracted, + as determined by could_extract_minus_sign, it is replaced + with Mul(-1, a, evaluate=False). This allows signs to be + extracted from powers and products. + + Examples + ======== + + >>> from sympy import signsimp, exp, symbols + >>> from sympy.abc import x, y + >>> i = symbols('i', odd=True) + >>> n = -1 + 1/x + >>> n/x/(-n)**2 - 1/n/x + (-1 + 1/x)/(x*(1 - 1/x)**2) - 1/(x*(-1 + 1/x)) + >>> signsimp(_) + 0 + >>> x*n + x*-n + x*(-1 + 1/x) + x*(1 - 1/x) + >>> signsimp(_) + 0 + + Since powers automatically handle leading signs + + >>> (-2)**i + -2**i + + signsimp can be used to put the base of a power with an integer + exponent into canonical form: + + >>> n**i + (-1 + 1/x)**i + + By default, signsimp does not leave behind any hollow simplification: + if making an Add canonical wrt sign didn't change the expression, the + original Add is restored. If this is not desired then the keyword + ``evaluate`` can be set to False: + + >>> e = exp(y - x) + >>> signsimp(e) == e + True + >>> signsimp(e, evaluate=False) + exp(-(x - y)) + + """ + if evaluate is None: + evaluate = global_parameters.evaluate + expr = sympify(expr) + if not isinstance(expr, (Expr, Relational)) or expr.is_Atom: + return expr + # get rid of an pre-existing unevaluation regarding sign + e = expr.replace(lambda x: x.is_Mul and -(-x) != x, lambda x: -(-x)) + e = sub_post(sub_pre(e)) + if not isinstance(e, (Expr, Relational)) or e.is_Atom: + return e + if e.is_Add: + rv = e.func(*[signsimp(a) for a in e.args]) + if not evaluate and isinstance(rv, Add + ) and rv.could_extract_minus_sign(): + return Mul(S.NegativeOne, -rv, evaluate=False) + return rv + if evaluate: + e = e.replace(lambda x: x.is_Mul and -(-x) != x, lambda x: -(-x)) + return e + + +@overload +def simplify(expr: Expr, **kwargs) -> Expr: ... +@overload +def simplify(expr: Boolean, **kwargs) -> Boolean: ... +@overload +def simplify(expr: Set, **kwargs) -> Set: ... +@overload +def simplify(expr: Basic, **kwargs) -> Basic: ... + +def simplify(expr, ratio=1.7, measure=count_ops, rational=False, inverse=False, doit=True, **kwargs): + """Simplifies the given expression. + + Explanation + =========== + + Simplification is not a well defined term and the exact strategies + this function tries can change in the future versions of SymPy. If + your algorithm relies on "simplification" (whatever it is), try to + determine what you need exactly - is it powsimp()?, radsimp()?, + together()?, logcombine()?, or something else? And use this particular + function directly, because those are well defined and thus your algorithm + will be robust. + + Nonetheless, especially for interactive use, or when you do not know + anything about the structure of the expression, simplify() tries to apply + intelligent heuristics to make the input expression "simpler". For + example: + + >>> from sympy import simplify, cos, sin + >>> from sympy.abc import x, y + >>> a = (x + x**2)/(x*sin(y)**2 + x*cos(y)**2) + >>> a + (x**2 + x)/(x*sin(y)**2 + x*cos(y)**2) + >>> simplify(a) + x + 1 + + Note that we could have obtained the same result by using specific + simplification functions: + + >>> from sympy import trigsimp, cancel + >>> trigsimp(a) + (x**2 + x)/x + >>> cancel(_) + x + 1 + + In some cases, applying :func:`simplify` may actually result in some more + complicated expression. The default ``ratio=1.7`` prevents more extreme + cases: if (result length)/(input length) > ratio, then input is returned + unmodified. The ``measure`` parameter lets you specify the function used + to determine how complex an expression is. The function should take a + single argument as an expression and return a number such that if + expression ``a`` is more complex than expression ``b``, then + ``measure(a) > measure(b)``. The default measure function is + :func:`~.count_ops`, which returns the total number of operations in the + expression. + + For example, if ``ratio=1``, ``simplify`` output cannot be longer + than input. + + :: + + >>> from sympy import sqrt, simplify, count_ops, oo + >>> root = 1/(sqrt(2)+3) + + Since ``simplify(root)`` would result in a slightly longer expression, + root is returned unchanged instead:: + + >>> simplify(root, ratio=1) == root + True + + If ``ratio=oo``, simplify will be applied anyway:: + + >>> count_ops(simplify(root, ratio=oo)) > count_ops(root) + True + + Note that the shortest expression is not necessary the simplest, so + setting ``ratio`` to 1 may not be a good idea. + Heuristically, the default value ``ratio=1.7`` seems like a reasonable + choice. + + You can easily define your own measure function based on what you feel + should represent the "size" or "complexity" of the input expression. Note + that some choices, such as ``lambda expr: len(str(expr))`` may appear to be + good metrics, but have other problems (in this case, the measure function + may slow down simplify too much for very large expressions). If you do not + know what a good metric would be, the default, ``count_ops``, is a good + one. + + For example: + + >>> from sympy import symbols, log + >>> a, b = symbols('a b', positive=True) + >>> g = log(a) + log(b) + log(a)*log(1/b) + >>> h = simplify(g) + >>> h + log(a*b**(1 - log(a))) + >>> count_ops(g) + 8 + >>> count_ops(h) + 5 + + So you can see that ``h`` is simpler than ``g`` using the count_ops metric. + However, we may not like how ``simplify`` (in this case, using + ``logcombine``) has created the ``b**(log(1/a) + 1)`` term. A simple way + to reduce this would be to give more weight to powers as operations in + ``count_ops``. We can do this by using the ``visual=True`` option: + + >>> print(count_ops(g, visual=True)) + 2*ADD + DIV + 4*LOG + MUL + >>> print(count_ops(h, visual=True)) + 2*LOG + MUL + POW + SUB + + >>> from sympy import Symbol, S + >>> def my_measure(expr): + ... POW = Symbol('POW') + ... # Discourage powers by giving POW a weight of 10 + ... count = count_ops(expr, visual=True).subs(POW, 10) + ... # Every other operation gets a weight of 1 (the default) + ... count = count.replace(Symbol, type(S.One)) + ... return count + >>> my_measure(g) + 8 + >>> my_measure(h) + 14 + >>> 15./8 > 1.7 # 1.7 is the default ratio + True + >>> simplify(g, measure=my_measure) + -log(a)*log(b) + log(a) + log(b) + + Note that because ``simplify()`` internally tries many different + simplification strategies and then compares them using the measure + function, we get a completely different result that is still different + from the input expression by doing this. + + If ``rational=True``, Floats will be recast as Rationals before simplification. + If ``rational=None``, Floats will be recast as Rationals but the result will + be recast as Floats. If rational=False(default) then nothing will be done + to the Floats. + + If ``inverse=True``, it will be assumed that a composition of inverse + functions, such as sin and asin, can be cancelled in any order. + For example, ``asin(sin(x))`` will yield ``x`` without checking whether + x belongs to the set where this relation is true. The default is + False. + + Note that ``simplify()`` automatically calls ``doit()`` on the final + expression. You can avoid this behavior by passing ``doit=False`` as + an argument. + + Also, it should be noted that simplifying a boolean expression is not + well defined. If the expression prefers automatic evaluation (such as + :obj:`~.Eq()` or :obj:`~.Or()`), simplification will return ``True`` or + ``False`` if truth value can be determined. If the expression is not + evaluated by default (such as :obj:`~.Predicate()`), simplification will + not reduce it and you should use :func:`~.refine` or :func:`~.ask` + function. This inconsistency will be resolved in future version. + + See Also + ======== + + sympy.assumptions.refine.refine : Simplification using assumptions. + sympy.assumptions.ask.ask : Query for boolean expressions using assumptions. + """ + + def shorter(*choices): + """ + Return the choice that has the fewest ops. In case of a tie, + the expression listed first is selected. + """ + if not has_variety(choices): + return choices[0] + return min(choices, key=measure) + + def done(e): + rv = e.doit() if doit else e + return shorter(rv, collect_abs(rv)) + + expr = sympify(expr, rational=rational) + kwargs = { + "ratio": kwargs.get('ratio', ratio), + "measure": kwargs.get('measure', measure), + "rational": kwargs.get('rational', rational), + "inverse": kwargs.get('inverse', inverse), + "doit": kwargs.get('doit', doit)} + # no routine for Expr needs to check for is_zero + if isinstance(expr, Expr) and expr.is_zero: + return S.Zero if not expr.is_Number else expr + + _eval_simplify = getattr(expr, '_eval_simplify', None) + if _eval_simplify is not None: + return _eval_simplify(**kwargs) + + original_expr = expr = collect_abs(signsimp(expr)) + + if not isinstance(expr, Basic) or not expr.args: # XXX: temporary hack + return expr + + if inverse and expr.has(Function): + expr = inversecombine(expr) + if not expr.args: # simplified to atomic + return expr + + # do deep simplification + handled = Add, Mul, Pow, ExpBase + expr = expr.replace( + # here, checking for x.args is not enough because Basic has + # args but Basic does not always play well with replace, e.g. + # when simultaneous is True found expressions will be masked + # off with a Dummy but not all Basic objects in an expression + # can be replaced with a Dummy + lambda x: isinstance(x, Expr) and x.args and not isinstance( + x, handled), + lambda x: x.func(*[simplify(i, **kwargs) for i in x.args]), + simultaneous=False) + if not isinstance(expr, handled): + return done(expr) + + if not expr.is_commutative: + expr = nc_simplify(expr) + + # TODO: Apply different strategies, considering expression pattern: + # is it a purely rational function? Is there any trigonometric function?... + # See also https://github.com/sympy/sympy/pull/185. + + # rationalize Floats + floats = False + if rational is not False and expr.has(Float): + floats = True + expr = nsimplify(expr, rational=True) + + expr = _bottom_up(expr, lambda w: getattr(w, 'normal', lambda: w)()) + expr = Mul(*powsimp(expr).as_content_primitive()) + _e = cancel(expr) + expr1 = shorter(_e, _mexpand(_e).cancel()) # issue 6829 + expr2 = shorter(together(expr, deep=True), together(expr1, deep=True)) + + if ratio is S.Infinity: + expr = expr2 + else: + expr = shorter(expr2, expr1, expr) + if not isinstance(expr, Basic): # XXX: temporary hack + return expr + + expr = factor_terms(expr, sign=False) + + # must come before `Piecewise` since this introduces more `Piecewise` terms + if expr.has(sign): + expr = expr.rewrite(Abs) + + # Deal with Piecewise separately to avoid recursive growth of expressions + if expr.has(Piecewise): + # Fold into a single Piecewise + expr = piecewise_fold(expr) + # Apply doit, if doit=True + expr = done(expr) + # Still a Piecewise? + if expr.has(Piecewise): + # Fold into a single Piecewise, in case doit lead to some + # expressions being Piecewise + expr = piecewise_fold(expr) + # kroneckersimp also affects Piecewise + if expr.has(KroneckerDelta): + expr = kroneckersimp(expr) + # Still a Piecewise? + if expr.has(Piecewise): + # Do not apply doit on the segments as it has already + # been done above, but simplify + expr = piecewise_simplify(expr, deep=True, doit=False) + # Still a Piecewise? + if expr.has(Piecewise): + # Try factor common terms + expr = shorter(expr, factor_terms(expr)) + # As all expressions have been simplified above with the + # complete simplify, nothing more needs to be done here + return expr + + # hyperexpand automatically only works on hypergeometric terms + # Do this after the Piecewise part to avoid recursive expansion + expr = hyperexpand(expr) + + if expr.has(KroneckerDelta): + expr = kroneckersimp(expr) + + if expr.has(BesselBase): + expr = besselsimp(expr) + + if expr.has(TrigonometricFunction, HyperbolicFunction): + expr = trigsimp(expr, deep=True) + + if expr.has(log): + expr = shorter(expand_log(expr, deep=True), logcombine(expr)) + + if expr.has(CombinatorialFunction, gamma): + # expression with gamma functions or non-integer arguments is + # automatically passed to gammasimp + expr = combsimp(expr) + + if expr.has(Sum): + expr = sum_simplify(expr, **kwargs) + + if expr.has(Integral): + expr = expr.xreplace({ + i: factor_terms(i) for i in expr.atoms(Integral)}) + + if expr.has(Product): + expr = product_simplify(expr, **kwargs) + + from sympy.physics.units import Quantity + + if expr.has(Quantity): + from sympy.physics.units.util import quantity_simplify + expr = quantity_simplify(expr) + + short = shorter(powsimp(expr, combine='exp', deep=True), powsimp(expr), expr) + short = shorter(short, cancel(short)) + short = shorter(short, factor_terms(short), expand_power_exp(expand_mul(short))) + if short.has(TrigonometricFunction, HyperbolicFunction, ExpBase, exp): + short = exptrigsimp(short) + + # get rid of hollow 2-arg Mul factorization + hollow_mul = Transform( + lambda x: Mul(*x.args), + lambda x: + x.is_Mul and + len(x.args) == 2 and + x.args[0].is_Number and + x.args[1].is_Add and + x.is_commutative) + expr = short.xreplace(hollow_mul) + + numer, denom = expr.as_numer_denom() + if denom.is_Add: + n, d = fraction(radsimp(1/denom, symbolic=False, max_terms=1)) + if n is not S.One: + expr = (numer*n).expand()/d + + if expr.could_extract_minus_sign(): + n, d = fraction(expr) + if d != 0: + expr = signsimp(-n/(-d)) + + if measure(expr) > ratio*measure(original_expr): + expr = original_expr + + # restore floats + if floats and rational is None: + expr = nfloat(expr, exponent=False) + + return done(expr) + + +def sum_simplify(s, **kwargs): + """Main function for Sum simplification""" + if not isinstance(s, Add): + s = s.xreplace({a: sum_simplify(a, **kwargs) + for a in s.atoms(Add) if a.has(Sum)}) + s = expand(s) + if not isinstance(s, Add): + return s + + terms = s.args + s_t = [] # Sum Terms + o_t = [] # Other Terms + + for term in terms: + sum_terms, other = sift(Mul.make_args(term), + lambda i: isinstance(i, Sum), binary=True) + if not sum_terms: + o_t.append(term) + continue + other = [Mul(*other)] + s_t.append(Mul(*(other + [s._eval_simplify(**kwargs) for s in sum_terms]))) + + result = Add(sum_combine(s_t), *o_t) + + return result + + +def sum_combine(s_t): + """Helper function for Sum simplification + + Attempts to simplify a list of sums, by combining limits / sum function's + returns the simplified sum + """ + used = [False] * len(s_t) + + for method in range(2): + for i, s_term1 in enumerate(s_t): + if not used[i]: + for j, s_term2 in enumerate(s_t): + if not used[j] and i != j: + temp = sum_add(s_term1, s_term2, method) + if isinstance(temp, (Sum, Mul)): + s_t[i] = temp + s_term1 = s_t[i] + used[j] = True + + result = S.Zero + for i, s_term in enumerate(s_t): + if not used[i]: + result = Add(result, s_term) + + return result + +def factor_sum(self, limits=None, radical=False, clear=False, fraction=False, sign=True): + """Return Sum with constant factors extracted. + + If ``limits`` is specified then ``self`` is the summand; the other + keywords are passed to ``factor_terms``. + + Examples + ======== + + >>> from sympy import Sum + >>> from sympy.abc import x, y + >>> from sympy.simplify.simplify import factor_sum + >>> s = Sum(x*y, (x, 1, 3)) + >>> factor_sum(s) + y*Sum(x, (x, 1, 3)) + >>> factor_sum(s.function, s.limits) + y*Sum(x, (x, 1, 3)) + """ + + # XXX deprecate in favor of direct call to factor_terms + kwargs = {"radical": radical, "clear": clear, + "fraction": fraction, "sign": sign} + expr = Sum(self, *limits) if limits else self + return factor_terms(expr, **kwargs) + + +def sum_add(self, other, method=0): + """Helper function for Sum simplification""" + #we know this is something in terms of a constant * a sum + #so we temporarily put the constants inside for simplification + #then simplify the result + def __refactor(val): + args = Mul.make_args(val) + sumv = next(x for x in args if isinstance(x, Sum)) + constant = Mul(*[x for x in args if x != sumv]) + return Sum(constant * sumv.function, *sumv.limits) + + if isinstance(self, Mul): + rself = __refactor(self) + else: + rself = self + + if isinstance(other, Mul): + rother = __refactor(other) + else: + rother = other + + if type(rself) is type(rother): + if method == 0: + if rself.limits == rother.limits: + return factor_sum(Sum(rself.function + rother.function, *rself.limits)) + elif method == 1: + if simplify(rself.function - rother.function) == 0: + if len(rself.limits) == len(rother.limits) == 1: + i = rself.limits[0][0] + x1 = rself.limits[0][1] + y1 = rself.limits[0][2] + j = rother.limits[0][0] + x2 = rother.limits[0][1] + y2 = rother.limits[0][2] + + if i == j: + if x2 == y1 + 1: + return factor_sum(Sum(rself.function, (i, x1, y2))) + elif x1 == y2 + 1: + return factor_sum(Sum(rself.function, (i, x2, y1))) + + return Add(self, other) + + +def product_simplify(s, **kwargs): + """Main function for Product simplification""" + terms = Mul.make_args(s) + p_t = [] # Product Terms + o_t = [] # Other Terms + + deep = kwargs.get('deep', True) + for term in terms: + if isinstance(term, Product): + if deep: + p_t.append(Product(term.function.simplify(**kwargs), + *term.limits)) + else: + p_t.append(term) + else: + o_t.append(term) + + used = [False] * len(p_t) + + for method in range(2): + for i, p_term1 in enumerate(p_t): + if not used[i]: + for j, p_term2 in enumerate(p_t): + if not used[j] and i != j: + tmp_prod = product_mul(p_term1, p_term2, method) + if isinstance(tmp_prod, Product): + p_t[i] = tmp_prod + used[j] = True + + result = Mul(*o_t) + + for i, p_term in enumerate(p_t): + if not used[i]: + result = Mul(result, p_term) + + return result + + +def product_mul(self, other, method=0): + """Helper function for Product simplification""" + if type(self) is type(other): + if method == 0: + if self.limits == other.limits: + return Product(self.function * other.function, *self.limits) + elif method == 1: + if simplify(self.function - other.function) == 0: + if len(self.limits) == len(other.limits) == 1: + i = self.limits[0][0] + x1 = self.limits[0][1] + y1 = self.limits[0][2] + j = other.limits[0][0] + x2 = other.limits[0][1] + y2 = other.limits[0][2] + + if i == j: + if x2 == y1 + 1: + return Product(self.function, (i, x1, y2)) + elif x1 == y2 + 1: + return Product(self.function, (i, x2, y1)) + + return Mul(self, other) + + +def _nthroot_solve(p, n, prec): + """ + helper function for ``nthroot`` + It denests ``p**Rational(1, n)`` using its minimal polynomial + """ + from sympy.solvers import solve + while n % 2 == 0: + p = sqrtdenest(sqrt(p)) + n = n // 2 + if n == 1: + return p + pn = p**Rational(1, n) + x = Symbol('x') + f = _minimal_polynomial_sq(p, n, x) + if f is None: + return None + sols = solve(f, x) + for sol in sols: + if abs(sol - pn).n() < 1./10**prec: + sol = sqrtdenest(sol) + if _mexpand(sol**n) == p: + return sol + + +def logcombine(expr, force=False): + """ + Takes logarithms and combines them using the following rules: + + - log(x) + log(y) == log(x*y) if both are positive + - a*log(x) == log(x**a) if x is positive and a is real + + If ``force`` is ``True`` then the assumptions above will be assumed to hold if + there is no assumption already in place on a quantity. For example, if + ``a`` is imaginary or the argument negative, force will not perform a + combination but if ``a`` is a symbol with no assumptions the change will + take place. + + Examples + ======== + + >>> from sympy import Symbol, symbols, log, logcombine, I + >>> from sympy.abc import a, x, y, z + >>> logcombine(a*log(x) + log(y) - log(z)) + a*log(x) + log(y) - log(z) + >>> logcombine(a*log(x) + log(y) - log(z), force=True) + log(x**a*y/z) + >>> x,y,z = symbols('x,y,z', positive=True) + >>> a = Symbol('a', real=True) + >>> logcombine(a*log(x) + log(y) - log(z)) + log(x**a*y/z) + + The transformation is limited to factors and/or terms that + contain logs, so the result depends on the initial state of + expansion: + + >>> eq = (2 + 3*I)*log(x) + >>> logcombine(eq, force=True) == eq + True + >>> logcombine(eq.expand(), force=True) + log(x**2) + I*log(x**3) + + See Also + ======== + + posify: replace all symbols with symbols having positive assumptions + sympy.core.function.expand_log: expand the logarithms of products + and powers; the opposite of logcombine + + """ + + def f(rv): + if not (rv.is_Add or rv.is_Mul): + return rv + + def gooda(a): + # bool to tell whether the leading ``a`` in ``a*log(x)`` + # could appear as log(x**a) + return (a is not S.NegativeOne and # -1 *could* go, but we disallow + (a.is_extended_real or force and a.is_extended_real is not False)) + + def goodlog(l): + # bool to tell whether log ``l``'s argument can combine with others + a = l.args[0] + return a.is_positive or force and a.is_nonpositive is not False + + other = [] + logs = [] + log1 = defaultdict(list) + for a in Add.make_args(rv): + if isinstance(a, log) and goodlog(a): + log1[()].append(([], a)) + elif not a.is_Mul: + other.append(a) + else: + ot = [] + co = [] + lo = [] + for ai in a.args: + if ai.is_Rational and ai < 0: + ot.append(S.NegativeOne) + co.append(-ai) + elif isinstance(ai, log) and goodlog(ai): + lo.append(ai) + elif gooda(ai): + co.append(ai) + else: + ot.append(ai) + if len(lo) > 1: + logs.append((ot, co, lo)) + elif lo: + log1[tuple(ot)].append((co, lo[0])) + else: + other.append(a) + + # if there is only one log in other, put it with the + # good logs + if len(other) == 1 and isinstance(other[0], log): + log1[()].append(([], other.pop())) + # if there is only one log at each coefficient and none have + # an exponent to place inside the log then there is nothing to do + if not logs and all(len(log1[k]) == 1 and log1[k][0] == [] for k in log1): + return rv + + # collapse multi-logs as far as possible in a canonical way + # TODO: see if x*log(a)+x*log(a)*log(b) -> x*log(a)*(1+log(b))? + # -- in this case, it's unambiguous, but if it were were a log(c) in + # each term then it's arbitrary whether they are grouped by log(a) or + # by log(c). So for now, just leave this alone; it's probably better to + # let the user decide + for o, e, l in logs: + l = list(ordered(l)) + e = log(l.pop(0).args[0]**Mul(*e)) + while l: + li = l.pop(0) + e = log(li.args[0]**e) + c, l = Mul(*o), e + if isinstance(l, log): # it should be, but check to be sure + log1[(c,)].append(([], l)) + else: + other.append(c*l) + + # logs that have the same coefficient can multiply + for k in list(log1.keys()): + log1[Mul(*k)] = log(logcombine(Mul(*[ + l.args[0]**Mul(*c) for c, l in log1.pop(k)]), + force=force), evaluate=False) + + # logs that have oppositely signed coefficients can divide + for k in ordered(list(log1.keys())): + if k not in log1: # already popped as -k + continue + if -k in log1: + # figure out which has the minus sign; the one with + # more op counts should be the one + num, den = k, -k + if num.count_ops() > den.count_ops(): + num, den = den, num + other.append( + num*log(log1.pop(num).args[0]/log1.pop(den).args[0], + evaluate=False)) + else: + other.append(k*log1.pop(k)) + + return Add(*other) + + return _bottom_up(expr, f) + + +def inversecombine(expr): + """Simplify the composition of a function and its inverse. + + Explanation + =========== + + No attention is paid to whether the inverse is a left inverse or a + right inverse; thus, the result will in general not be equivalent + to the original expression. + + Examples + ======== + + >>> from sympy.simplify.simplify import inversecombine + >>> from sympy import asin, sin, log, exp + >>> from sympy.abc import x + >>> inversecombine(asin(sin(x))) + x + >>> inversecombine(2*log(exp(3*x))) + 6*x + """ + + def f(rv): + if isinstance(rv, log): + if isinstance(rv.args[0], exp) or (rv.args[0].is_Pow and rv.args[0].base == S.Exp1): + rv = rv.args[0].exp + elif rv.is_Function and hasattr(rv, "inverse"): + if (len(rv.args) == 1 and len(rv.args[0].args) == 1 and + isinstance(rv.args[0], rv.inverse(argindex=1))): + rv = rv.args[0].args[0] + if rv.is_Pow and rv.base == S.Exp1: + if isinstance(rv.exp, log): + rv = rv.exp.args[0] + return rv + + return _bottom_up(expr, f) + + +def kroneckersimp(expr): + """ + Simplify expressions with KroneckerDelta. + + The only simplification currently attempted is to identify multiplicative cancellation: + + Examples + ======== + + >>> from sympy import KroneckerDelta, kroneckersimp + >>> from sympy.abc import i + >>> kroneckersimp(1 + KroneckerDelta(0, i) * KroneckerDelta(1, i)) + 1 + """ + def args_cancel(args1, args2): + for i1 in range(2): + for i2 in range(2): + a1 = args1[i1] + a2 = args2[i2] + a3 = args1[(i1 + 1) % 2] + a4 = args2[(i2 + 1) % 2] + if Eq(a1, a2) is S.true and Eq(a3, a4) is S.false: + return True + return False + + def cancel_kronecker_mul(m): + args = m.args + deltas = [a for a in args if isinstance(a, KroneckerDelta)] + for delta1, delta2 in subsets(deltas, 2): + args1 = delta1.args + args2 = delta2.args + if args_cancel(args1, args2): + return S.Zero * m # In case of oo etc + return m + + if not expr.has(KroneckerDelta): + return expr + + if expr.has(Piecewise): + expr = expr.rewrite(KroneckerDelta) + + newexpr = expr + expr = None + + while newexpr != expr: + expr = newexpr + newexpr = expr.replace(lambda e: isinstance(e, Mul), cancel_kronecker_mul) + + return expr + + +def besselsimp(expr): + """ + Simplify bessel-type functions. + + Explanation + =========== + + This routine tries to simplify bessel-type functions. Currently it only + works on the Bessel J and I functions, however. It works by looking at all + such functions in turn, and eliminating factors of "I" and "-1" (actually + their polar equivalents) in front of the argument. Then, functions of + half-integer order are rewritten using trigonometric functions and + functions of integer order (> 1) are rewritten using functions + of low order. Finally, if the expression was changed, compute + factorization of the result with factor(). + + >>> from sympy import besselj, besseli, besselsimp, polar_lift, I, S + >>> from sympy.abc import z, nu + >>> besselsimp(besselj(nu, z*polar_lift(-1))) + exp(I*pi*nu)*besselj(nu, z) + >>> besselsimp(besseli(nu, z*polar_lift(-I))) + exp(-I*pi*nu/2)*besselj(nu, z) + >>> besselsimp(besseli(S(-1)/2, z)) + sqrt(2)*cosh(z)/(sqrt(pi)*sqrt(z)) + >>> besselsimp(z*besseli(0, z) + z*(besseli(2, z))/2 + besseli(1, z)) + 3*z*besseli(0, z)/2 + """ + # TODO + # - better algorithm? + # - simplify (cos(pi*b)*besselj(b,z) - besselj(-b,z))/sin(pi*b) ... + # - use contiguity relations? + + def replacer(fro, to, factors): + factors = set(factors) + + def repl(nu, z): + if factors.intersection(Mul.make_args(z)): + return to(nu, z) + return fro(nu, z) + return repl + + def torewrite(fro, to): + def tofunc(nu, z): + return fro(nu, z).rewrite(to) + return tofunc + + def tominus(fro): + def tofunc(nu, z): + return exp(I*pi*nu)*fro(nu, exp_polar(-I*pi)*z) + return tofunc + + orig_expr = expr + + ifactors = [I, exp_polar(I*pi/2), exp_polar(-I*pi/2)] + expr = expr.replace( + besselj, replacer(besselj, + torewrite(besselj, besseli), ifactors)) + expr = expr.replace( + besseli, replacer(besseli, + torewrite(besseli, besselj), ifactors)) + + minusfactors = [-1, exp_polar(I*pi)] + expr = expr.replace( + besselj, replacer(besselj, tominus(besselj), minusfactors)) + expr = expr.replace( + besseli, replacer(besseli, tominus(besseli), minusfactors)) + + z0 = Dummy('z') + + def expander(fro): + def repl(nu, z): + if (nu % 1) == S.Half: + return simplify(trigsimp(unpolarify( + fro(nu, z0).rewrite(besselj).rewrite(jn).expand( + func=True)).subs(z0, z))) + elif nu.is_Integer and nu > 1: + return fro(nu, z).expand(func=True) + return fro(nu, z) + return repl + + expr = expr.replace(besselj, expander(besselj)) + expr = expr.replace(bessely, expander(bessely)) + expr = expr.replace(besseli, expander(besseli)) + expr = expr.replace(besselk, expander(besselk)) + + def _bessel_simp_recursion(expr): + + def _use_recursion(bessel, expr): + while True: + bessels = expr.find(lambda x: isinstance(x, bessel)) + try: + for ba in sorted(bessels, key=lambda x: re(x.args[0])): + a, x = ba.args + bap1 = bessel(a+1, x) + bap2 = bessel(a+2, x) + if expr.has(bap1) and expr.has(bap2): + expr = expr.subs(ba, 2*(a+1)/x*bap1 - bap2) + break + else: + return expr + except (ValueError, TypeError): + return expr + if expr.has(besselj): + expr = _use_recursion(besselj, expr) + if expr.has(bessely): + expr = _use_recursion(bessely, expr) + return expr + + expr = _bessel_simp_recursion(expr) + if expr != orig_expr: + expr = expr.factor() + + return expr + + +def nthroot(expr, n, max_len=4, prec=15): + """ + Compute a real nth-root of a sum of surds. + + Parameters + ========== + + expr : sum of surds + n : integer + max_len : maximum number of surds passed as constants to ``nsimplify`` + + Algorithm + ========= + + First ``nsimplify`` is used to get a candidate root; if it is not a + root the minimal polynomial is computed; the answer is one of its + roots. + + Examples + ======== + + >>> from sympy.simplify.simplify import nthroot + >>> from sympy import sqrt + >>> nthroot(90 + 34*sqrt(7), 3) + sqrt(7) + 3 + + """ + expr = sympify(expr) + n = sympify(n) + p = expr**Rational(1, n) + if not n.is_integer: + return p + if not _is_sum_surds(expr): + return p + surds = [] + coeff_muls = [x.as_coeff_Mul() for x in expr.args] + for x, y in coeff_muls: + if not x.is_rational: + return p + if y is S.One: + continue + if not (y.is_Pow and y.exp == S.Half and y.base.is_integer): + return p + surds.append(y) + surds.sort() + surds = surds[:max_len] + if expr < 0 and n % 2 == 1: + p = (-expr)**Rational(1, n) + a = nsimplify(p, constants=surds) + res = a if _mexpand(a**n) == _mexpand(-expr) else p + return -res + a = nsimplify(p, constants=surds) + if _mexpand(a) is not _mexpand(p) and _mexpand(a**n) == _mexpand(expr): + return _mexpand(a) + expr = _nthroot_solve(expr, n, prec) + if expr is None: + return p + return expr + + +def nsimplify(expr, constants=(), tolerance=None, full=False, rational=None, + rational_conversion='base10'): + """ + Find a simple representation for a number or, if there are free symbols or + if ``rational=True``, then replace Floats with their Rational equivalents. If + no change is made and rational is not False then Floats will at least be + converted to Rationals. + + Explanation + =========== + + For numerical expressions, a simple formula that numerically matches the + given numerical expression is sought (and the input should be possible + to evalf to a precision of at least 30 digits). + + Optionally, a list of (rationally independent) constants to + include in the formula may be given. + + A lower tolerance may be set to find less exact matches. If no tolerance + is given then the least precise value will set the tolerance (e.g. Floats + default to 15 digits of precision, so would be tolerance=10**-15). + + With ``full=True``, a more extensive search is performed + (this is useful to find simpler numbers when the tolerance + is set low). + + When converting to rational, if rational_conversion='base10' (the default), then + convert floats to rationals using their base-10 (string) representation. + When rational_conversion='exact' it uses the exact, base-2 representation. + + Examples + ======== + + >>> from sympy import nsimplify, sqrt, GoldenRatio, exp, I, pi + >>> nsimplify(4/(1+sqrt(5)), [GoldenRatio]) + -2 + 2*GoldenRatio + >>> nsimplify((1/(exp(3*pi*I/5)+1))) + 1/2 - I*sqrt(sqrt(5)/10 + 1/4) + >>> nsimplify(I**I, [pi]) + exp(-pi/2) + >>> nsimplify(pi, tolerance=0.01) + 22/7 + + >>> nsimplify(0.333333333333333, rational=True, rational_conversion='exact') + 6004799503160655/18014398509481984 + >>> nsimplify(0.333333333333333, rational=True) + 1/3 + + See Also + ======== + + sympy.core.function.nfloat + + """ + try: + return sympify(as_int(expr)) + except (TypeError, ValueError): + pass + expr = sympify(expr).xreplace({ + Float('inf'): S.Infinity, + Float('-inf'): S.NegativeInfinity, + }) + if expr is S.Infinity or expr is S.NegativeInfinity: + return expr + if rational or expr.free_symbols: + return _real_to_rational(expr, tolerance, rational_conversion) + + # SymPy's default tolerance for Rationals is 15; other numbers may have + # lower tolerances set, so use them to pick the largest tolerance if None + # was given + if tolerance is None: + tolerance = 10**-min([15] + + [mpmath.libmp.libmpf.prec_to_dps(n._prec) + for n in expr.atoms(Float)]) + # XXX should prec be set independent of tolerance or should it be computed + # from tolerance? + prec = 30 + bprec = int(prec*3.33) + + constants_dict = {} + for constant in constants: + constant = sympify(constant) + v = constant.evalf(prec) + if not v.is_Float: + raise ValueError("constants must be real-valued") + constants_dict[str(constant)] = v._to_mpmath(bprec) + + exprval = expr.evalf(prec, chop=True) + re, im = exprval.as_real_imag() + + # safety check to make sure that this evaluated to a number + if not (re.is_Number and im.is_Number): + return expr + + def nsimplify_real(x): + orig = mpmath.mp.dps + xv = x._to_mpmath(bprec) + try: + # We'll be happy with low precision if a simple fraction + if not (tolerance or full): + mpmath.mp.dps = 15 + rat = mpmath.pslq([xv, 1]) + if rat is not None: + return Rational(-int(rat[1]), int(rat[0])) + mpmath.mp.dps = prec + newexpr = mpmath.identify(xv, constants=constants_dict, + tol=tolerance, full=full) + if not newexpr: + raise ValueError + if full: + newexpr = newexpr[0] + expr = sympify(newexpr) + if x and not expr: # don't let x become 0 + raise ValueError + if expr.is_finite is False and xv not in [mpmath.inf, mpmath.ninf]: + raise ValueError + return expr + finally: + # even though there are returns above, this is executed + # before leaving + mpmath.mp.dps = orig + try: + if re: + re = nsimplify_real(re) + if im: + im = nsimplify_real(im) + except ValueError: + if rational is None: + return _real_to_rational(expr, rational_conversion=rational_conversion) + return expr + + rv = re + im*S.ImaginaryUnit + # if there was a change or rational is explicitly not wanted + # return the value, else return the Rational representation + if rv != expr or rational is False: + return rv + return _real_to_rational(expr, rational_conversion=rational_conversion) + + +def _real_to_rational(expr, tolerance=None, rational_conversion='base10'): + """ + Replace all reals in expr with rationals. + + Examples + ======== + + >>> from sympy.simplify.simplify import _real_to_rational + >>> from sympy.abc import x + + >>> _real_to_rational(.76 + .1*x**.5) + sqrt(x)/10 + 19/25 + + If rational_conversion='base10', this uses the base-10 string. If + rational_conversion='exact', the exact, base-2 representation is used. + + >>> _real_to_rational(0.333333333333333, rational_conversion='exact') + 6004799503160655/18014398509481984 + >>> _real_to_rational(0.333333333333333) + 1/3 + + """ + expr = _sympify(expr) + inf = Float('inf') + p = expr + reps = {} + reduce_num = None + if tolerance is not None and tolerance < 1: + reduce_num = ceiling(1/tolerance) + for fl in p.atoms(Float): + key = fl + if reduce_num is not None: + r = Rational(fl).limit_denominator(reduce_num) + elif (tolerance is not None and tolerance >= 1 and + fl.is_Integer is False): + r = Rational(tolerance*round(fl/tolerance) + ).limit_denominator(int(tolerance)) + else: + if rational_conversion == 'exact': + r = Rational(fl) + reps[key] = r + continue + elif rational_conversion != 'base10': + raise ValueError("rational_conversion must be 'base10' or 'exact'") + + r = nsimplify(fl, rational=False) + # e.g. log(3).n() -> log(3) instead of a Rational + if fl and not r: + r = Rational(fl) + elif not r.is_Rational: + if fl in (inf, -inf): + r = S.ComplexInfinity + elif fl < 0: + fl = -fl + d = Pow(10, int(mpmath.log(fl)/mpmath.log(10))) + r = -Rational(str(fl/d))*d + elif fl > 0: + d = Pow(10, int(mpmath.log(fl)/mpmath.log(10))) + r = Rational(str(fl/d))*d + else: + r = S.Zero + reps[key] = r + return p.subs(reps, simultaneous=True) + + +def clear_coefficients(expr, rhs=S.Zero): + """Return `p, r` where `p` is the expression obtained when Rational + additive and multiplicative coefficients of `expr` have been stripped + away in a naive fashion (i.e. without simplification). The operations + needed to remove the coefficients will be applied to `rhs` and returned + as `r`. + + Examples + ======== + + >>> from sympy.simplify.simplify import clear_coefficients + >>> from sympy.abc import x, y + >>> from sympy import Dummy + >>> expr = 4*y*(6*x + 3) + >>> clear_coefficients(expr - 2) + (y*(2*x + 1), 1/6) + + When solving 2 or more expressions like `expr = a`, + `expr = b`, etc..., it is advantageous to provide a Dummy symbol + for `rhs` and simply replace it with `a`, `b`, etc... in `r`. + + >>> rhs = Dummy('rhs') + >>> clear_coefficients(expr, rhs) + (y*(2*x + 1), _rhs/12) + >>> _[1].subs(rhs, 2) + 1/6 + """ + was = None + free = expr.free_symbols + if expr.is_Rational: + return (S.Zero, rhs - expr) + while expr and was != expr: + was = expr + m, expr = ( + expr.as_content_primitive() + if free else + factor_terms(expr).as_coeff_Mul(rational=True)) + rhs /= m + c, expr = expr.as_coeff_Add(rational=True) + rhs -= c + expr = signsimp(expr, evaluate = False) + if expr.could_extract_minus_sign(): + expr = -expr + rhs = -rhs + return expr, rhs + +def nc_simplify(expr, deep=True): + ''' + Simplify a non-commutative expression composed of multiplication + and raising to a power by grouping repeated subterms into one power. + Priority is given to simplifications that give the fewest number + of arguments in the end (for example, in a*b*a*b*c*a*b*c simplifying + to (a*b)**2*c*a*b*c gives 5 arguments while a*b*(a*b*c)**2 has 3). + If ``expr`` is a sum of such terms, the sum of the simplified terms + is returned. + + Keyword argument ``deep`` controls whether or not subexpressions + nested deeper inside the main expression are simplified. See examples + below. Setting `deep` to `False` can save time on nested expressions + that do not need simplifying on all levels. + + Examples + ======== + + >>> from sympy import symbols + >>> from sympy.simplify.simplify import nc_simplify + >>> a, b, c = symbols("a b c", commutative=False) + >>> nc_simplify(a*b*a*b*c*a*b*c) + a*b*(a*b*c)**2 + >>> expr = a**2*b*a**4*b*a**4 + >>> nc_simplify(expr) + a**2*(b*a**4)**2 + >>> nc_simplify(a*b*a*b*c**2*(a*b)**2*c**2) + ((a*b)**2*c**2)**2 + >>> nc_simplify(a*b*a*b + 2*a*c*a**2*c*a**2*c*a) + (a*b)**2 + 2*(a*c*a)**3 + >>> nc_simplify(b**-1*a**-1*(a*b)**2) + a*b + >>> nc_simplify(a**-1*b**-1*c*a) + (b*a)**(-1)*c*a + >>> expr = (a*b*a*b)**2*a*c*a*c + >>> nc_simplify(expr) + (a*b)**4*(a*c)**2 + >>> nc_simplify(expr, deep=False) + (a*b*a*b)**2*(a*c)**2 + + ''' + if isinstance(expr, MatrixExpr): + expr = expr.doit(inv_expand=False) + _Add, _Mul, _Pow, _Symbol = MatAdd, MatMul, MatPow, MatrixSymbol + else: + _Add, _Mul, _Pow, _Symbol = Add, Mul, Pow, Symbol + + # =========== Auxiliary functions ======================== + def _overlaps(args): + # Calculate a list of lists m such that m[i][j] contains the lengths + # of all possible overlaps between args[:i+1] and args[i+1+j:]. + # An overlap is a suffix of the prefix that matches a prefix + # of the suffix. + # For example, let expr=c*a*b*a*b*a*b*a*b. Then m[3][0] contains + # the lengths of overlaps of c*a*b*a*b with a*b*a*b. The overlaps + # are a*b*a*b, a*b and the empty word so that m[3][0]=[4,2,0]. + # All overlaps rather than only the longest one are recorded + # because this information helps calculate other overlap lengths. + m = [[([1, 0] if a == args[0] else [0]) for a in args[1:]]] + for i in range(1, len(args)): + overlaps = [] + j = 0 + for j in range(len(args) - i - 1): + overlap = [] + for v in m[i-1][j+1]: + if j + i + 1 + v < len(args) and args[i] == args[j+i+1+v]: + overlap.append(v + 1) + overlap += [0] + overlaps.append(overlap) + m.append(overlaps) + return m + + def _reduce_inverses(_args): + # replace consecutive negative powers by an inverse + # of a product of positive powers, e.g. a**-1*b**-1*c + # will simplify to (a*b)**-1*c; + # return that new args list and the number of negative + # powers in it (inv_tot) + inv_tot = 0 # total number of inverses + inverses = [] + args = [] + for arg in _args: + if isinstance(arg, _Pow) and arg.args[1].is_extended_negative: + inverses = [arg**-1] + inverses + inv_tot += 1 + else: + if len(inverses) == 1: + args.append(inverses[0]**-1) + elif len(inverses) > 1: + args.append(_Pow(_Mul(*inverses), -1)) + inv_tot -= len(inverses) - 1 + inverses = [] + args.append(arg) + if inverses: + args.append(_Pow(_Mul(*inverses), -1)) + inv_tot -= len(inverses) - 1 + return inv_tot, tuple(args) + + def get_score(s): + # compute the number of arguments of s + # (including in nested expressions) overall + # but ignore exponents + if isinstance(s, _Pow): + return get_score(s.args[0]) + elif isinstance(s, (_Add, _Mul)): + return sum(get_score(a) for a in s.args) + return 1 + + def compare(s, alt_s): + # compare two possible simplifications and return a + # "better" one + if s != alt_s and get_score(alt_s) < get_score(s): + return alt_s + return s + # ======================================================== + + if not isinstance(expr, (_Add, _Mul, _Pow)) or expr.is_commutative: + return expr + args = expr.args[:] + if isinstance(expr, _Pow): + if deep: + return _Pow(nc_simplify(args[0]), args[1]).doit() + else: + return expr + elif isinstance(expr, _Add): + return _Add(*[nc_simplify(a, deep=deep) for a in args]).doit() + else: + # get the non-commutative part + c_args, args = expr.args_cnc() + com_coeff = Mul(*c_args) + if not equal_valued(com_coeff, 1): + return com_coeff*nc_simplify(expr/com_coeff, deep=deep) + + inv_tot, args = _reduce_inverses(args) + # if most arguments are negative, work with the inverse + # of the expression, e.g. a**-1*b*a**-1*c**-1 will become + # (c*a*b**-1*a)**-1 at the end so can work with c*a*b**-1*a + invert = False + if inv_tot > len(args)/2: + invert = True + args = [a**-1 for a in args[::-1]] + + if deep: + args = tuple(nc_simplify(a) for a in args) + + m = _overlaps(args) + + # simps will be {subterm: end} where `end` is the ending + # index of a sequence of repetitions of subterm; + # this is for not wasting time with subterms that are part + # of longer, already considered sequences + simps = {} + + post = 1 + pre = 1 + + # the simplification coefficient is the number of + # arguments by which contracting a given sequence + # would reduce the word; e.g. in a*b*a*b*c*a*b*c, + # contracting a*b*a*b to (a*b)**2 removes 3 arguments + # while a*b*c*a*b*c to (a*b*c)**2 removes 6. It's + # better to contract the latter so simplification + # with a maximum simplification coefficient will be chosen + max_simp_coeff = 0 + simp = None # information about future simplification + + for i in range(1, len(args)): + simp_coeff = 0 + l = 0 # length of a subterm + p = 0 # the power of a subterm + if i < len(args) - 1: + rep = m[i][0] + start = i # starting index of the repeated sequence + end = i+1 # ending index of the repeated sequence + if i == len(args)-1 or rep == [0]: + # no subterm is repeated at this stage, at least as + # far as the arguments are concerned - there may be + # a repetition if powers are taken into account + if (isinstance(args[i], _Pow) and + not isinstance(args[i].args[0], _Symbol)): + subterm = args[i].args[0].args + l = len(subterm) + if args[i-l:i] == subterm: + # e.g. a*b in a*b*(a*b)**2 is not repeated + # in args (= [a, b, (a*b)**2]) but it + # can be matched here + p += 1 + start -= l + if args[i+1:i+1+l] == subterm: + # e.g. a*b in (a*b)**2*a*b + p += 1 + end += l + if p: + p += args[i].args[1] + else: + continue + else: + l = rep[0] # length of the longest repeated subterm at this point + start -= l - 1 + subterm = args[start:end] + p = 2 + end += l + + if subterm in simps and simps[subterm] >= start: + # the subterm is part of a sequence that + # has already been considered + continue + + # count how many times it's repeated + while end < len(args): + if l in m[end-1][0]: + p += 1 + end += l + elif isinstance(args[end], _Pow) and args[end].args[0].args == subterm: + # for cases like a*b*a*b*(a*b)**2*a*b + p += args[end].args[1] + end += 1 + else: + break + + # see if another match can be made, e.g. + # for b*a**2 in b*a**2*b*a**3 or a*b in + # a**2*b*a*b + + pre_exp = 0 + pre_arg = 1 + if start - l >= 0 and args[start-l+1:start] == subterm[1:]: + if isinstance(subterm[0], _Pow): + pre_arg = subterm[0].args[0] + exp = subterm[0].args[1] + else: + pre_arg = subterm[0] + exp = 1 + if isinstance(args[start-l], _Pow) and args[start-l].args[0] == pre_arg: + pre_exp = args[start-l].args[1] - exp + start -= l + p += 1 + elif args[start-l] == pre_arg: + pre_exp = 1 - exp + start -= l + p += 1 + + post_exp = 0 + post_arg = 1 + if end + l - 1 < len(args) and args[end:end+l-1] == subterm[:-1]: + if isinstance(subterm[-1], _Pow): + post_arg = subterm[-1].args[0] + exp = subterm[-1].args[1] + else: + post_arg = subterm[-1] + exp = 1 + if isinstance(args[end+l-1], _Pow) and args[end+l-1].args[0] == post_arg: + post_exp = args[end+l-1].args[1] - exp + end += l + p += 1 + elif args[end+l-1] == post_arg: + post_exp = 1 - exp + end += l + p += 1 + + # Consider a*b*a**2*b*a**2*b*a: + # b*a**2 is explicitly repeated, but note + # that in this case a*b*a is also repeated + # so there are two possible simplifications: + # a*(b*a**2)**3*a**-1 or (a*b*a)**3 + # The latter is obviously simpler. + # But in a*b*a**2*b**2*a**2 the simplifications are + # a*(b*a**2)**2 and (a*b*a)**3*a in which case + # it's better to stick with the shorter subterm + if post_exp and exp % 2 == 0 and start > 0: + exp = exp/2 + _pre_exp = 1 + _post_exp = 1 + if isinstance(args[start-1], _Pow) and args[start-1].args[0] == post_arg: + _post_exp = post_exp + exp + _pre_exp = args[start-1].args[1] - exp + elif args[start-1] == post_arg: + _post_exp = post_exp + exp + _pre_exp = 1 - exp + if _pre_exp == 0 or _post_exp == 0: + if not pre_exp: + start -= 1 + post_exp = _post_exp + pre_exp = _pre_exp + pre_arg = post_arg + subterm = (post_arg**exp,) + subterm[:-1] + (post_arg**exp,) + + simp_coeff += end-start + + if post_exp: + simp_coeff -= 1 + if pre_exp: + simp_coeff -= 1 + + simps[subterm] = end + + if simp_coeff > max_simp_coeff: + max_simp_coeff = simp_coeff + simp = (start, _Mul(*subterm), p, end, l) + pre = pre_arg**pre_exp + post = post_arg**post_exp + + if simp: + subterm = _Pow(nc_simplify(simp[1], deep=deep), simp[2]) + pre = nc_simplify(_Mul(*args[:simp[0]])*pre, deep=deep) + post = post*nc_simplify(_Mul(*args[simp[3]:]), deep=deep) + simp = pre*subterm*post + if pre != 1 or post != 1: + # new simplifications may be possible but no need + # to recurse over arguments + simp = nc_simplify(simp, deep=False) + else: + simp = _Mul(*args) + + if invert: + simp = _Pow(simp, -1) + + # see if factor_nc(expr) is simplified better + if not isinstance(expr, MatrixExpr): + f_expr = factor_nc(expr) + if f_expr != expr: + alt_simp = nc_simplify(f_expr, deep=deep) + simp = compare(simp, alt_simp) + else: + simp = simp.doit(inv_expand=False) + return simp + + +def dotprodsimp(expr, withsimp=False): + """Simplification for a sum of products targeted at the kind of blowup that + occurs during summation of products. Intended to reduce expression blowup + during matrix multiplication or other similar operations. Only works with + algebraic expressions and does not recurse into non. + + Parameters + ========== + + withsimp : bool, optional + Specifies whether a flag should be returned along with the expression + to indicate roughly whether simplification was successful. It is used + in ``MatrixArithmetic._eval_pow_by_recursion`` to avoid attempting to + simplify an expression repetitively which does not simplify. + """ + + def count_ops_alg(expr): + """Optimized count algebraic operations with no recursion into + non-algebraic args that ``core.function.count_ops`` does. Also returns + whether rational functions may be present according to negative + exponents of powers or non-number fractions. + + Returns + ======= + + ops, ratfunc : int, bool + ``ops`` is the number of algebraic operations starting at the top + level expression (not recursing into non-alg children). ``ratfunc`` + specifies whether the expression MAY contain rational functions + which ``cancel`` MIGHT optimize. + """ + + ops = 0 + args = [expr] + ratfunc = False + + while args: + a = args.pop() + + if not isinstance(a, Basic): + continue + + if a.is_Rational: + if a is not S.One: # -1/3 = NEG + DIV + ops += bool (a.p < 0) + bool (a.q != 1) + + elif a.is_Mul: + if a.could_extract_minus_sign(): + ops += 1 + if a.args[0] is S.NegativeOne: + a = a.as_two_terms()[1] + else: + a = -a + + n, d = fraction(a) + + if n.is_Integer: + ops += 1 + bool (n < 0) + args.append(d) # won't be -Mul but could be Add + + elif d is not S.One: + if not d.is_Integer: + args.append(d) + ratfunc=True + + ops += 1 + args.append(n) # could be -Mul + + else: + ops += len(a.args) - 1 + args.extend(a.args) + + elif a.is_Add: + laargs = len(a.args) + negs = 0 + + for ai in a.args: + if ai.could_extract_minus_sign(): + negs += 1 + ai = -ai + args.append(ai) + + ops += laargs - (negs != laargs) # -x - y = NEG + SUB + + elif a.is_Pow: + ops += 1 + args.append(a.base) + + if not ratfunc: + ratfunc = a.exp.is_negative is not False + + return ops, ratfunc + + def nonalg_subs_dummies(expr, dummies): + """Substitute dummy variables for non-algebraic expressions to avoid + evaluation of non-algebraic terms that ``polys.polytools.cancel`` does. + """ + + if not expr.args: + return expr + + if expr.is_Add or expr.is_Mul or expr.is_Pow: + args = None + + for i, a in enumerate(expr.args): + c = nonalg_subs_dummies(a, dummies) + + if c is a: + continue + + if args is None: + args = list(expr.args) + + args[i] = c + + if args is None: + return expr + + return expr.func(*args) + + return dummies.setdefault(expr, Dummy()) + + simplified = False # doesn't really mean simplified, rather "can simplify again" + + if isinstance(expr, Basic) and (expr.is_Add or expr.is_Mul or expr.is_Pow): + expr2 = expr.expand(deep=True, modulus=None, power_base=False, + power_exp=False, mul=True, log=False, multinomial=True, basic=False) + + if expr2 != expr: + expr = expr2 + simplified = True + + exprops, ratfunc = count_ops_alg(expr) + + if exprops >= 6: # empirically tested cutoff for expensive simplification + if ratfunc: + dummies = {} + expr2 = nonalg_subs_dummies(expr, dummies) + + if expr2 is expr or count_ops_alg(expr2)[0] >= 6: # check again after substitution + expr3 = cancel(expr2) + + if expr3 != expr2: + expr = expr3.subs([(d, e) for e, d in dummies.items()]) + simplified = True + + # very special case: x/(x-1) - 1/(x-1) -> 1 + elif (exprops == 5 and expr.is_Add and expr.args [0].is_Mul and + expr.args [1].is_Mul and expr.args [0].args [-1].is_Pow and + expr.args [1].args [-1].is_Pow and + expr.args [0].args [-1].exp is S.NegativeOne and + expr.args [1].args [-1].exp is S.NegativeOne): + + expr2 = together (expr) + expr2ops = count_ops_alg(expr2)[0] + + if expr2ops < exprops: + expr = expr2 + simplified = True + + else: + simplified = True + + return (expr, simplified) if withsimp else expr + + +bottom_up = deprecated( + """ + Using bottom_up from the sympy.simplify.simplify submodule is + deprecated. + + Instead, use bottom_up from the top-level sympy namespace, like + + sympy.bottom_up + """, + deprecated_since_version="1.10", + active_deprecations_target="deprecated-traversal-functions-moved", +)(_bottom_up) + + +# XXX: This function really should either be private API or exported in the +# top-level sympy/__init__.py +walk = deprecated( + """ + Using walk from the sympy.simplify.simplify submodule is + deprecated. + + Instead, use walk from sympy.core.traversal.walk + """, + deprecated_since_version="1.10", + active_deprecations_target="deprecated-traversal-functions-moved", +)(_walk) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/sqrtdenest.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/sqrtdenest.py new file mode 100644 index 0000000000000000000000000000000000000000..d266de7e62a4b7d37a2109f7091ff91e4df7c79d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/sqrtdenest.py @@ -0,0 +1,678 @@ +from sympy.core import Add, Expr, Mul, S, sympify +from sympy.core.function import _mexpand, count_ops, expand_mul +from sympy.core.sorting import default_sort_key +from sympy.core.symbol import Dummy +from sympy.functions import root, sign, sqrt +from sympy.polys import Poly, PolynomialError + + +def is_sqrt(expr): + """Return True if expr is a sqrt, otherwise False.""" + + return expr.is_Pow and expr.exp.is_Rational and abs(expr.exp) is S.Half + + +def sqrt_depth(p) -> int: + """Return the maximum depth of any square root argument of p. + + >>> from sympy.functions.elementary.miscellaneous import sqrt + >>> from sympy.simplify.sqrtdenest import sqrt_depth + + Neither of these square roots contains any other square roots + so the depth is 1: + + >>> sqrt_depth(1 + sqrt(2)*(1 + sqrt(3))) + 1 + + The sqrt(3) is contained within a square root so the depth is + 2: + + >>> sqrt_depth(1 + sqrt(2)*sqrt(1 + sqrt(3))) + 2 + """ + if p is S.ImaginaryUnit: + return 1 + if p.is_Atom: + return 0 + if p.is_Add or p.is_Mul: + return max(sqrt_depth(x) for x in p.args) + if is_sqrt(p): + return sqrt_depth(p.base) + 1 + return 0 + + +def is_algebraic(p): + """Return True if p is comprised of only Rationals or square roots + of Rationals and algebraic operations. + + Examples + ======== + + >>> from sympy.functions.elementary.miscellaneous import sqrt + >>> from sympy.simplify.sqrtdenest import is_algebraic + >>> from sympy import cos + >>> is_algebraic(sqrt(2)*(3/(sqrt(7) + sqrt(5)*sqrt(2)))) + True + >>> is_algebraic(sqrt(2)*(3/(sqrt(7) + sqrt(5)*cos(2)))) + False + """ + + if p.is_Rational: + return True + elif p.is_Atom: + return False + elif is_sqrt(p) or p.is_Pow and p.exp.is_Integer: + return is_algebraic(p.base) + elif p.is_Add or p.is_Mul: + return all(is_algebraic(x) for x in p.args) + else: + return False + + +def _subsets(n): + """ + Returns all possible subsets of the set (0, 1, ..., n-1) except the + empty set, listed in reversed lexicographical order according to binary + representation, so that the case of the fourth root is treated last. + + Examples + ======== + + >>> from sympy.simplify.sqrtdenest import _subsets + >>> _subsets(2) + [[1, 0], [0, 1], [1, 1]] + + """ + if n == 1: + a = [[1]] + elif n == 2: + a = [[1, 0], [0, 1], [1, 1]] + elif n == 3: + a = [[1, 0, 0], [0, 1, 0], [1, 1, 0], + [0, 0, 1], [1, 0, 1], [0, 1, 1], [1, 1, 1]] + else: + b = _subsets(n - 1) + a0 = [x + [0] for x in b] + a1 = [x + [1] for x in b] + a = a0 + [[0]*(n - 1) + [1]] + a1 + return a + + +def sqrtdenest(expr, max_iter=3): + """Denests sqrts in an expression that contain other square roots + if possible, otherwise returns the expr unchanged. This is based on the + algorithms of [1]. + + Examples + ======== + + >>> from sympy.simplify.sqrtdenest import sqrtdenest + >>> from sympy import sqrt + >>> sqrtdenest(sqrt(5 + 2 * sqrt(6))) + sqrt(2) + sqrt(3) + + See Also + ======== + + sympy.solvers.solvers.unrad + + References + ========== + + .. [1] https://web.archive.org/web/20210806201615/https://researcher.watson.ibm.com/researcher/files/us-fagin/symb85.pdf + + .. [2] D. J. Jeffrey and A. D. Rich, 'Symplifying Square Roots of Square Roots + by Denesting' (available at https://www.cybertester.com/data/denest.pdf) + + """ + expr = expand_mul(expr) + for i in range(max_iter): + z = _sqrtdenest0(expr) + if expr == z: + return expr + expr = z + return expr + + +def _sqrt_match(p): + """Return [a, b, r] for p.match(a + b*sqrt(r)) where, in addition to + matching, sqrt(r) also has then maximal sqrt_depth among addends of p. + + Examples + ======== + + >>> from sympy.functions.elementary.miscellaneous import sqrt + >>> from sympy.simplify.sqrtdenest import _sqrt_match + >>> _sqrt_match(1 + sqrt(2) + sqrt(2)*sqrt(3) + 2*sqrt(1+sqrt(5))) + [1 + sqrt(2) + sqrt(6), 2, 1 + sqrt(5)] + """ + from sympy.simplify.radsimp import split_surds + + p = _mexpand(p) + if p.is_Number: + res = (p, S.Zero, S.Zero) + elif p.is_Add: + pargs = sorted(p.args, key=default_sort_key) + sqargs = [x**2 for x in pargs] + if all(sq.is_Rational and sq.is_positive for sq in sqargs): + r, b, a = split_surds(p) + res = a, b, r + return list(res) + # to make the process canonical, the argument is included in the tuple + # so when the max is selected, it will be the largest arg having a + # given depth + v = [(sqrt_depth(x), x, i) for i, x in enumerate(pargs)] + nmax = max(v, key=default_sort_key) + if nmax[0] == 0: + res = [] + else: + # select r + depth, _, i = nmax + r = pargs.pop(i) + v.pop(i) + b = S.One + if r.is_Mul: + bv = [] + rv = [] + for x in r.args: + if sqrt_depth(x) < depth: + bv.append(x) + else: + rv.append(x) + b = Mul._from_args(bv) + r = Mul._from_args(rv) + # collect terms containing r + a1 = [] + b1 = [b] + for x in v: + if x[0] < depth: + a1.append(x[1]) + else: + x1 = x[1] + if x1 == r: + b1.append(1) + else: + if x1.is_Mul: + x1args = list(x1.args) + if r in x1args: + x1args.remove(r) + b1.append(Mul(*x1args)) + else: + a1.append(x[1]) + else: + a1.append(x[1]) + a = Add(*a1) + b = Add(*b1) + res = (a, b, r**2) + else: + b, r = p.as_coeff_Mul() + if is_sqrt(r): + res = (S.Zero, b, r**2) + else: + res = [] + return list(res) + + +class SqrtdenestStopIteration(StopIteration): + pass + + +def _sqrtdenest0(expr): + """Returns expr after denesting its arguments.""" + + if is_sqrt(expr): + n, d = expr.as_numer_denom() + if d is S.One: # n is a square root + if n.base.is_Add: + args = sorted(n.base.args, key=default_sort_key) + if len(args) > 2 and all((x**2).is_Integer for x in args): + try: + return _sqrtdenest_rec(n) + except SqrtdenestStopIteration: + pass + expr = sqrt(_mexpand(Add(*[_sqrtdenest0(x) for x in args]))) + return _sqrtdenest1(expr) + else: + n, d = [_sqrtdenest0(i) for i in (n, d)] + return n/d + + if isinstance(expr, Add): + cs = [] + args = [] + for arg in expr.args: + c, a = arg.as_coeff_Mul() + cs.append(c) + args.append(a) + + if all(c.is_Rational for c in cs) and all(is_sqrt(arg) for arg in args): + return _sqrt_ratcomb(cs, args) + + if isinstance(expr, Expr): + args = expr.args + if args: + return expr.func(*[_sqrtdenest0(a) for a in args]) + return expr + + +def _sqrtdenest_rec(expr): + """Helper that denests the square root of three or more surds. + + Explanation + =========== + + It returns the denested expression; if it cannot be denested it + throws SqrtdenestStopIteration + + Algorithm: expr.base is in the extension Q_m = Q(sqrt(r_1),..,sqrt(r_k)); + split expr.base = a + b*sqrt(r_k), where `a` and `b` are on + Q_(m-1) = Q(sqrt(r_1),..,sqrt(r_(k-1))); then a**2 - b**2*r_k is + on Q_(m-1); denest sqrt(a**2 - b**2*r_k) and so on. + See [1], section 6. + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.simplify.sqrtdenest import _sqrtdenest_rec + >>> _sqrtdenest_rec(sqrt(-72*sqrt(2) + 158*sqrt(5) + 498)) + -sqrt(10) + sqrt(2) + 9 + 9*sqrt(5) + >>> w=-6*sqrt(55)-6*sqrt(35)-2*sqrt(22)-2*sqrt(14)+2*sqrt(77)+6*sqrt(10)+65 + >>> _sqrtdenest_rec(sqrt(w)) + -sqrt(11) - sqrt(7) + sqrt(2) + 3*sqrt(5) + """ + from sympy.simplify.radsimp import radsimp, rad_rationalize, split_surds + if not expr.is_Pow: + return sqrtdenest(expr) + if expr.base < 0: + return sqrt(-1)*_sqrtdenest_rec(sqrt(-expr.base)) + g, a, b = split_surds(expr.base) + a = a*sqrt(g) + if a < b: + a, b = b, a + c2 = _mexpand(a**2 - b**2) + if len(c2.args) > 2: + g, a1, b1 = split_surds(c2) + a1 = a1*sqrt(g) + if a1 < b1: + a1, b1 = b1, a1 + c2_1 = _mexpand(a1**2 - b1**2) + c_1 = _sqrtdenest_rec(sqrt(c2_1)) + d_1 = _sqrtdenest_rec(sqrt(a1 + c_1)) + num, den = rad_rationalize(b1, d_1) + c = _mexpand(d_1/sqrt(2) + num/(den*sqrt(2))) + else: + c = _sqrtdenest1(sqrt(c2)) + + if sqrt_depth(c) > 1: + raise SqrtdenestStopIteration + ac = a + c + if len(ac.args) >= len(expr.args): + if count_ops(ac) >= count_ops(expr.base): + raise SqrtdenestStopIteration + d = sqrtdenest(sqrt(ac)) + if sqrt_depth(d) > 1: + raise SqrtdenestStopIteration + num, den = rad_rationalize(b, d) + r = d/sqrt(2) + num/(den*sqrt(2)) + r = radsimp(r) + return _mexpand(r) + + +def _sqrtdenest1(expr, denester=True): + """Return denested expr after denesting with simpler methods or, that + failing, using the denester.""" + + from sympy.simplify.simplify import radsimp + + if not is_sqrt(expr): + return expr + + a = expr.base + if a.is_Atom: + return expr + val = _sqrt_match(a) + if not val: + return expr + + a, b, r = val + # try a quick numeric denesting + d2 = _mexpand(a**2 - b**2*r) + if d2.is_Rational: + if d2.is_positive: + z = _sqrt_numeric_denest(a, b, r, d2) + if z is not None: + return z + else: + # fourth root case + # sqrtdenest(sqrt(3 + 2*sqrt(3))) = + # sqrt(2)*3**(1/4)/2 + sqrt(2)*3**(3/4)/2 + dr2 = _mexpand(-d2*r) + dr = sqrt(dr2) + if dr.is_Rational: + z = _sqrt_numeric_denest(_mexpand(b*r), a, r, dr2) + if z is not None: + return z/root(r, 4) + + else: + z = _sqrt_symbolic_denest(a, b, r) + if z is not None: + return z + + if not denester or not is_algebraic(expr): + return expr + + res = sqrt_biquadratic_denest(expr, a, b, r, d2) + if res: + return res + + # now call to the denester + av0 = [a, b, r, d2] + z = _denester([radsimp(expr**2)], av0, 0, sqrt_depth(expr))[0] + if av0[1] is None: + return expr + if z is not None: + if sqrt_depth(z) == sqrt_depth(expr) and count_ops(z) > count_ops(expr): + return expr + return z + return expr + + +def _sqrt_symbolic_denest(a, b, r): + """Given an expression, sqrt(a + b*sqrt(b)), return the denested + expression or None. + + Explanation + =========== + + If r = ra + rb*sqrt(rr), try replacing sqrt(rr) in ``a`` with + (y**2 - ra)/rb, and if the result is a quadratic, ca*y**2 + cb*y + cc, and + (cb + b)**2 - 4*ca*cc is 0, then sqrt(a + b*sqrt(r)) can be rewritten as + sqrt(ca*(sqrt(r) + (cb + b)/(2*ca))**2). + + Examples + ======== + + >>> from sympy.simplify.sqrtdenest import _sqrt_symbolic_denest, sqrtdenest + >>> from sympy import sqrt, Symbol + >>> from sympy.abc import x + + >>> a, b, r = 16 - 2*sqrt(29), 2, -10*sqrt(29) + 55 + >>> _sqrt_symbolic_denest(a, b, r) + sqrt(11 - 2*sqrt(29)) + sqrt(5) + + If the expression is numeric, it will be simplified: + + >>> w = sqrt(sqrt(sqrt(3) + 1) + 1) + 1 + sqrt(2) + >>> sqrtdenest(sqrt((w**2).expand())) + 1 + sqrt(2) + sqrt(1 + sqrt(1 + sqrt(3))) + + Otherwise, it will only be simplified if assumptions allow: + + >>> w = w.subs(sqrt(3), sqrt(x + 3)) + >>> sqrtdenest(sqrt((w**2).expand())) + sqrt((sqrt(sqrt(sqrt(x + 3) + 1) + 1) + 1 + sqrt(2))**2) + + Notice that the argument of the sqrt is a square. If x is made positive + then the sqrt of the square is resolved: + + >>> _.subs(x, Symbol('x', positive=True)) + sqrt(sqrt(sqrt(x + 3) + 1) + 1) + 1 + sqrt(2) + """ + + a, b, r = map(sympify, (a, b, r)) + rval = _sqrt_match(r) + if not rval: + return None + ra, rb, rr = rval + if rb: + y = Dummy('y', positive=True) + try: + newa = Poly(a.subs(sqrt(rr), (y**2 - ra)/rb), y) + except PolynomialError: + return None + if newa.degree() == 2: + ca, cb, cc = newa.all_coeffs() + cb += b + if _mexpand(cb**2 - 4*ca*cc).equals(0): + z = sqrt(ca*(sqrt(r) + cb/(2*ca))**2) + if z.is_number: + z = _mexpand(Mul._from_args(z.as_content_primitive())) + return z + + +def _sqrt_numeric_denest(a, b, r, d2): + r"""Helper that denest + $\sqrt{a + b \sqrt{r}}, d^2 = a^2 - b^2 r > 0$ + + If it cannot be denested, it returns ``None``. + """ + d = sqrt(d2) + s = a + d + # sqrt_depth(res) <= sqrt_depth(s) + 1 + # sqrt_depth(expr) = sqrt_depth(r) + 2 + # there is denesting if sqrt_depth(s) + 1 < sqrt_depth(r) + 2 + # if s**2 is Number there is a fourth root + if sqrt_depth(s) < sqrt_depth(r) + 1 or (s**2).is_Rational: + s1, s2 = sign(s), sign(b) + if s1 == s2 == -1: + s1 = s2 = 1 + res = (s1 * sqrt(a + d) + s2 * sqrt(a - d)) * sqrt(2) / 2 + return res.expand() + + +def sqrt_biquadratic_denest(expr, a, b, r, d2): + """denest expr = sqrt(a + b*sqrt(r)) + where a, b, r are linear combinations of square roots of + positive rationals on the rationals (SQRR) and r > 0, b != 0, + d2 = a**2 - b**2*r > 0 + + If it cannot denest it returns None. + + Explanation + =========== + + Search for a solution A of type SQRR of the biquadratic equation + 4*A**4 - 4*a*A**2 + b**2*r = 0 (1) + sqd = sqrt(a**2 - b**2*r) + Choosing the sqrt to be positive, the possible solutions are + A = sqrt(a/2 +/- sqd/2) + Since a, b, r are SQRR, then a**2 - b**2*r is a SQRR, + so if sqd can be denested, it is done by + _sqrtdenest_rec, and the result is a SQRR. + Similarly for A. + Examples of solutions (in both cases a and sqd are positive): + + Example of expr with solution sqrt(a/2 + sqd/2) but not + solution sqrt(a/2 - sqd/2): + expr = sqrt(-sqrt(15) - sqrt(2)*sqrt(-sqrt(5) + 5) - sqrt(3) + 8) + a = -sqrt(15) - sqrt(3) + 8; sqd = -2*sqrt(5) - 2 + 4*sqrt(3) + + Example of expr with solution sqrt(a/2 - sqd/2) but not + solution sqrt(a/2 + sqd/2): + w = 2 + r2 + r3 + (1 + r3)*sqrt(2 + r2 + 5*r3) + expr = sqrt((w**2).expand()) + a = 4*sqrt(6) + 8*sqrt(2) + 47 + 28*sqrt(3) + sqd = 29 + 20*sqrt(3) + + Define B = b/2*A; eq.(1) implies a = A**2 + B**2*r; then + expr**2 = a + b*sqrt(r) = (A + B*sqrt(r))**2 + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.simplify.sqrtdenest import _sqrt_match, sqrt_biquadratic_denest + >>> z = sqrt((2*sqrt(2) + 4)*sqrt(2 + sqrt(2)) + 5*sqrt(2) + 8) + >>> a, b, r = _sqrt_match(z**2) + >>> d2 = a**2 - b**2*r + >>> sqrt_biquadratic_denest(z, a, b, r, d2) + sqrt(2) + sqrt(sqrt(2) + 2) + 2 + """ + from sympy.simplify.radsimp import radsimp, rad_rationalize + if r <= 0 or d2 < 0 or not b or sqrt_depth(expr.base) < 2: + return None + for x in (a, b, r): + for y in x.args: + y2 = y**2 + if not y2.is_Integer or not y2.is_positive: + return None + sqd = _mexpand(sqrtdenest(sqrt(radsimp(d2)))) + if sqrt_depth(sqd) > 1: + return None + x1, x2 = [a/2 + sqd/2, a/2 - sqd/2] + # look for a solution A with depth 1 + for x in (x1, x2): + A = sqrtdenest(sqrt(x)) + if sqrt_depth(A) > 1: + continue + Bn, Bd = rad_rationalize(b, _mexpand(2*A)) + B = Bn/Bd + z = A + B*sqrt(r) + if z < 0: + z = -z + return _mexpand(z) + return None + + +def _denester(nested, av0, h, max_depth_level): + """Denests a list of expressions that contain nested square roots. + + Explanation + =========== + + Algorithm based on . + + It is assumed that all of the elements of 'nested' share the same + bottom-level radicand. (This is stated in the paper, on page 177, in + the paragraph immediately preceding the algorithm.) + + When evaluating all of the arguments in parallel, the bottom-level + radicand only needs to be denested once. This means that calling + _denester with x arguments results in a recursive invocation with x+1 + arguments; hence _denester has polynomial complexity. + + However, if the arguments were evaluated separately, each call would + result in two recursive invocations, and the algorithm would have + exponential complexity. + + This is discussed in the paper in the middle paragraph of page 179. + """ + from sympy.simplify.simplify import radsimp + if h > max_depth_level: + return None, None + if av0[1] is None: + return None, None + if (av0[0] is None and + all(n.is_Number for n in nested)): # no arguments are nested + for f in _subsets(len(nested)): # test subset 'f' of nested + p = _mexpand(Mul(*[nested[i] for i in range(len(f)) if f[i]])) + if f.count(1) > 1 and f[-1]: + p = -p + sqp = sqrt(p) + if sqp.is_Rational: + return sqp, f # got a perfect square so return its square root. + # Otherwise, return the radicand from the previous invocation. + return sqrt(nested[-1]), [0]*len(nested) + else: + R = None + if av0[0] is not None: + values = [av0[:2]] + R = av0[2] + nested2 = [av0[3], R] + av0[0] = None + else: + values = list(filter(None, [_sqrt_match(expr) for expr in nested])) + for v in values: + if v[2]: # Since if b=0, r is not defined + if R is not None: + if R != v[2]: + av0[1] = None + return None, None + else: + R = v[2] + if R is None: + # return the radicand from the previous invocation + return sqrt(nested[-1]), [0]*len(nested) + nested2 = [_mexpand(v[0]**2) - + _mexpand(R*v[1]**2) for v in values] + [R] + d, f = _denester(nested2, av0, h + 1, max_depth_level) + if not f: + return None, None + if not any(f[i] for i in range(len(nested))): + v = values[-1] + return sqrt(v[0] + _mexpand(v[1]*d)), f + else: + p = Mul(*[nested[i] for i in range(len(nested)) if f[i]]) + v = _sqrt_match(p) + if 1 in f and f.index(1) < len(nested) - 1 and f[len(nested) - 1]: + v[0] = -v[0] + v[1] = -v[1] + if not f[len(nested)]: # Solution denests with square roots + vad = _mexpand(v[0] + d) + if vad <= 0: + # return the radicand from the previous invocation. + return sqrt(nested[-1]), [0]*len(nested) + if not(sqrt_depth(vad) <= sqrt_depth(R) + 1 or + (vad**2).is_Number): + av0[1] = None + return None, None + + sqvad = _sqrtdenest1(sqrt(vad), denester=False) + if not (sqrt_depth(sqvad) <= sqrt_depth(R) + 1): + av0[1] = None + return None, None + sqvad1 = radsimp(1/sqvad) + res = _mexpand(sqvad/sqrt(2) + (v[1]*sqrt(R)*sqvad1/sqrt(2))) + return res, f + + # sign(v[1])*sqrt(_mexpand(v[1]**2*R*vad1/2))), f + else: # Solution requires a fourth root + s2 = _mexpand(v[1]*R) + d + if s2 <= 0: + return sqrt(nested[-1]), [0]*len(nested) + FR, s = root(_mexpand(R), 4), sqrt(s2) + return _mexpand(s/(sqrt(2)*FR) + v[0]*FR/(sqrt(2)*s)), f + + +def _sqrt_ratcomb(cs, args): + """Denest rational combinations of radicals. + + Based on section 5 of [1]. + + Examples + ======== + + >>> from sympy import sqrt + >>> from sympy.simplify.sqrtdenest import sqrtdenest + >>> z = sqrt(1+sqrt(3)) + sqrt(3+3*sqrt(3)) - sqrt(10+6*sqrt(3)) + >>> sqrtdenest(z) + 0 + """ + from sympy.simplify.radsimp import radsimp + + # check if there exists a pair of sqrt that can be denested + def find(a): + n = len(a) + for i in range(n - 1): + for j in range(i + 1, n): + s1 = a[i].base + s2 = a[j].base + p = _mexpand(s1 * s2) + s = sqrtdenest(sqrt(p)) + if s != sqrt(p): + return s, i, j + + indices = find(args) + if indices is None: + return Add(*[c * arg for c, arg in zip(cs, args)]) + + s, i1, i2 = indices + + c2 = cs.pop(i2) + args.pop(i2) + a1 = args[i1] + + # replace a2 by s/a1 + cs[i1] += radsimp(c2 * s / a1.base) + + return _sqrt_ratcomb(cs, args) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_combsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_combsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..e56758a005fbb013c2b6ea4121b16c3434a54b03 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_combsimp.py @@ -0,0 +1,75 @@ +from sympy.core.numbers import Rational +from sympy.core.symbol import symbols +from sympy.functions.combinatorial.factorials import (FallingFactorial, RisingFactorial, binomial, factorial) +from sympy.functions.special.gamma_functions import gamma +from sympy.simplify.combsimp import combsimp +from sympy.abc import x + + +def test_combsimp(): + k, m, n = symbols('k m n', integer = True) + + assert combsimp(factorial(n)) == factorial(n) + assert combsimp(binomial(n, k)) == binomial(n, k) + + assert combsimp(factorial(n)/factorial(n - 3)) == n*(-1 + n)*(-2 + n) + assert combsimp(binomial(n + 1, k + 1)/binomial(n, k)) == (1 + n)/(1 + k) + + assert combsimp(binomial(3*n + 4, n + 1)/binomial(3*n + 1, n)) == \ + Rational(3, 2)*((3*n + 2)*(3*n + 4)/((n + 1)*(2*n + 3))) + + assert combsimp(factorial(n)**2/factorial(n - 3)) == \ + factorial(n)*n*(-1 + n)*(-2 + n) + assert combsimp(factorial(n)*binomial(n + 1, k + 1)/binomial(n, k)) == \ + factorial(n + 1)/(1 + k) + + assert combsimp(gamma(n + 3)) == factorial(n + 2) + + assert combsimp(factorial(x)) == gamma(x + 1) + + # issue 9699 + assert combsimp((n + 1)*factorial(n)) == factorial(n + 1) + assert combsimp(factorial(n)/n) == factorial(n-1) + + # issue 6658 + assert combsimp(binomial(n, n - k)) == binomial(n, k) + + # issue 6341, 7135 + assert combsimp(factorial(n)/(factorial(k)*factorial(n - k))) == \ + binomial(n, k) + assert combsimp(factorial(k)*factorial(n - k)/factorial(n)) == \ + 1/binomial(n, k) + assert combsimp(factorial(2*n)/factorial(n)**2) == binomial(2*n, n) + assert combsimp(factorial(2*n)*factorial(k)*factorial(n - k)/ + factorial(n)**3) == binomial(2*n, n)/binomial(n, k) + + assert combsimp(factorial(n*(1 + n) - n**2 - n)) == 1 + + assert combsimp(6*FallingFactorial(-4, n)/factorial(n)) == \ + (-1)**n*(n + 1)*(n + 2)*(n + 3) + assert combsimp(6*FallingFactorial(-4, n - 1)/factorial(n - 1)) == \ + (-1)**(n - 1)*n*(n + 1)*(n + 2) + assert combsimp(6*FallingFactorial(-4, n - 3)/factorial(n - 3)) == \ + (-1)**(n - 3)*n*(n - 1)*(n - 2) + assert combsimp(6*FallingFactorial(-4, -n - 1)/factorial(-n - 1)) == \ + -(-1)**(-n - 1)*n*(n - 1)*(n - 2) + + assert combsimp(6*RisingFactorial(4, n)/factorial(n)) == \ + (n + 1)*(n + 2)*(n + 3) + assert combsimp(6*RisingFactorial(4, n - 1)/factorial(n - 1)) == \ + n*(n + 1)*(n + 2) + assert combsimp(6*RisingFactorial(4, n - 3)/factorial(n - 3)) == \ + n*(n - 1)*(n - 2) + assert combsimp(6*RisingFactorial(4, -n - 1)/factorial(-n - 1)) == \ + -n*(n - 1)*(n - 2) + + +def test_issue_6878(): + n = symbols('n', integer=True) + assert combsimp(RisingFactorial(-10, n)) == 3628800*(-1)**n/factorial(10 - n) + + +def test_issue_14528(): + p = symbols("p", integer=True, positive=True) + assert combsimp(binomial(1,p)) == 1/(factorial(p)*factorial(1-p)) + assert combsimp(factorial(2-p)) == factorial(2-p) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_cse.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_cse.py new file mode 100644 index 0000000000000000000000000000000000000000..c2a34dfb0e227547bd41bed2491284fd7150d0b6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_cse.py @@ -0,0 +1,761 @@ +from functools import reduce +import itertools +from operator import add + +from sympy.codegen.matrix_nodes import MatrixSolve +from sympy.core.add import Add +from sympy.core.containers import Tuple +from sympy.core.expr import UnevaluatedExpr +from sympy.core.function import Function +from sympy.core.mul import Mul +from sympy.core.power import Pow +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.core.sympify import sympify +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.matrices.dense import Matrix +from sympy.matrices.expressions import Inverse, MatAdd, MatMul, Transpose +from sympy.polys.rootoftools import CRootOf +from sympy.series.order import O +from sympy.simplify.cse_main import cse +from sympy.simplify.simplify import signsimp +from sympy.tensor.indexed import (Idx, IndexedBase) + +from sympy.core.function import count_ops +from sympy.simplify.cse_opts import sub_pre, sub_post +from sympy.functions.special.hyper import meijerg +from sympy.simplify import cse_main, cse_opts +from sympy.utilities.iterables import subsets +from sympy.testing.pytest import XFAIL, raises +from sympy.matrices import (MutableDenseMatrix, MutableSparseMatrix, + ImmutableDenseMatrix, ImmutableSparseMatrix) +from sympy.matrices.expressions import MatrixSymbol + + +w, x, y, z = symbols('w,x,y,z') +x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12 = symbols('x:13') + + +def test_numbered_symbols(): + ns = cse_main.numbered_symbols(prefix='y') + assert list(itertools.islice( + ns, 0, 10)) == [Symbol('y%s' % i) for i in range(0, 10)] + ns = cse_main.numbered_symbols(prefix='y') + assert list(itertools.islice( + ns, 10, 20)) == [Symbol('y%s' % i) for i in range(10, 20)] + ns = cse_main.numbered_symbols() + assert list(itertools.islice( + ns, 0, 10)) == [Symbol('x%s' % i) for i in range(0, 10)] + +# Dummy "optimization" functions for testing. + + +def opt1(expr): + return expr + y + + +def opt2(expr): + return expr*z + + +def test_preprocess_for_cse(): + assert cse_main.preprocess_for_cse(x, [(opt1, None)]) == x + y + assert cse_main.preprocess_for_cse(x, [(None, opt1)]) == x + assert cse_main.preprocess_for_cse(x, [(None, None)]) == x + assert cse_main.preprocess_for_cse(x, [(opt1, opt2)]) == x + y + assert cse_main.preprocess_for_cse( + x, [(opt1, None), (opt2, None)]) == (x + y)*z + + +def test_postprocess_for_cse(): + assert cse_main.postprocess_for_cse(x, [(opt1, None)]) == x + assert cse_main.postprocess_for_cse(x, [(None, opt1)]) == x + y + assert cse_main.postprocess_for_cse(x, [(None, None)]) == x + assert cse_main.postprocess_for_cse(x, [(opt1, opt2)]) == x*z + # Note the reverse order of application. + assert cse_main.postprocess_for_cse( + x, [(None, opt1), (None, opt2)]) == x*z + y + + +def test_cse_single(): + # Simple substitution. + e = Add(Pow(x + y, 2), sqrt(x + y)) + substs, reduced = cse([e]) + assert substs == [(x0, x + y)] + assert reduced == [sqrt(x0) + x0**2] + + subst42, (red42,) = cse([42]) # issue_15082 + assert len(subst42) == 0 and red42 == 42 + subst_half, (red_half,) = cse([0.5]) + assert len(subst_half) == 0 and red_half == 0.5 + + +def test_cse_single2(): + # Simple substitution, test for being able to pass the expression directly + e = Add(Pow(x + y, 2), sqrt(x + y)) + substs, reduced = cse(e) + assert substs == [(x0, x + y)] + assert reduced == [sqrt(x0) + x0**2] + substs, reduced = cse(Matrix([[1]])) + assert isinstance(reduced[0], Matrix) + + subst42, (red42,) = cse(42) # issue 15082 + assert len(subst42) == 0 and red42 == 42 + subst_half, (red_half,) = cse(0.5) # issue 15082 + assert len(subst_half) == 0 and red_half == 0.5 + + +def test_cse_not_possible(): + # No substitution possible. + e = Add(x, y) + substs, reduced = cse([e]) + assert substs == [] + assert reduced == [x + y] + # issue 6329 + eq = (meijerg((1, 2), (y, 4), (5,), [], x) + + meijerg((1, 3), (y, 4), (5,), [], x)) + assert cse(eq) == ([], [eq]) + + +def test_nested_substitution(): + # Substitution within a substitution. + e = Add(Pow(w*x + y, 2), sqrt(w*x + y)) + substs, reduced = cse([e]) + assert substs == [(x0, w*x + y)] + assert reduced == [sqrt(x0) + x0**2] + + +def test_subtraction_opt(): + # Make sure subtraction is optimized. + e = (x - y)*(z - y) + exp((x - y)*(z - y)) + substs, reduced = cse( + [e], optimizations=[(cse_opts.sub_pre, cse_opts.sub_post)]) + assert substs == [(x0, (x - y)*(y - z))] + assert reduced == [-x0 + exp(-x0)] + e = -(x - y)*(z - y) + exp(-(x - y)*(z - y)) + substs, reduced = cse( + [e], optimizations=[(cse_opts.sub_pre, cse_opts.sub_post)]) + assert substs == [(x0, (x - y)*(y - z))] + assert reduced == [x0 + exp(x0)] + # issue 4077 + n = -1 + 1/x + e = n/x/(-n)**2 - 1/n/x + assert cse(e, optimizations=[(cse_opts.sub_pre, cse_opts.sub_post)]) == \ + ([], [0]) + assert cse(((w + x + y + z)*(w - y - z))/(w + x)**3) == \ + ([(x0, w + x), (x1, y + z)], [(w - x1)*(x0 + x1)/x0**3]) + + +def test_multiple_expressions(): + e1 = (x + y)*z + e2 = (x + y)*w + substs, reduced = cse([e1, e2]) + assert substs == [(x0, x + y)] + assert reduced == [x0*z, x0*w] + l = [w*x*y + z, w*y] + substs, reduced = cse(l) + rsubsts, _ = cse(reversed(l)) + assert substs == rsubsts + assert reduced == [z + x*x0, x0] + l = [w*x*y, w*x*y + z, w*y] + substs, reduced = cse(l) + rsubsts, _ = cse(reversed(l)) + assert substs == rsubsts + assert reduced == [x1, x1 + z, x0] + l = [(x - z)*(y - z), x - z, y - z] + substs, reduced = cse(l) + rsubsts, _ = cse(reversed(l)) + assert substs == [(x0, -z), (x1, x + x0), (x2, x0 + y)] + assert rsubsts == [(x0, -z), (x1, x0 + y), (x2, x + x0)] + assert reduced == [x1*x2, x1, x2] + l = [w*y + w + x + y + z, w*x*y] + assert cse(l) == ([(x0, w*y)], [w + x + x0 + y + z, x*x0]) + assert cse([x + y, x + y + z]) == ([(x0, x + y)], [x0, z + x0]) + assert cse([x + y, x + z]) == ([], [x + y, x + z]) + assert cse([x*y, z + x*y, x*y*z + 3]) == \ + ([(x0, x*y)], [x0, z + x0, 3 + x0*z]) + + +@XFAIL # CSE of non-commutative Mul terms is disabled +def test_non_commutative_cse(): + A, B, C = symbols('A B C', commutative=False) + l = [A*B*C, A*C] + assert cse(l) == ([], l) + l = [A*B*C, A*B] + assert cse(l) == ([(x0, A*B)], [x0*C, x0]) + + +# Test if CSE of non-commutative Mul terms is disabled +def test_bypass_non_commutatives(): + A, B, C = symbols('A B C', commutative=False) + l = [A*B*C, A*C] + assert cse(l) == ([], l) + l = [A*B*C, A*B] + assert cse(l) == ([], l) + l = [B*C, A*B*C] + assert cse(l) == ([], l) + + +@XFAIL # CSE fails when replacing non-commutative sub-expressions +def test_non_commutative_order(): + A, B, C = symbols('A B C', commutative=False) + x0 = symbols('x0', commutative=False) + l = [B+C, A*(B+C)] + assert cse(l) == ([(x0, B+C)], [x0, A*x0]) + + +@XFAIL # Worked in gh-11232, but was reverted due to performance considerations +def test_issue_10228(): + assert cse([x*y**2 + x*y]) == ([(x0, x*y)], [x0*y + x0]) + assert cse([x + y, 2*x + y]) == ([(x0, x + y)], [x0, x + x0]) + assert cse((w + 2*x + y + z, w + x + 1)) == ( + [(x0, w + x)], [x0 + x + y + z, x0 + 1]) + assert cse(((w + x + y + z)*(w - x))/(w + x)) == ( + [(x0, w + x)], [(x0 + y + z)*(w - x)/x0]) + a, b, c, d, f, g, j, m = symbols('a, b, c, d, f, g, j, m') + exprs = (d*g**2*j*m, 4*a*f*g*m, a*b*c*f**2) + assert cse(exprs) == ( + [(x0, g*m), (x1, a*f)], [d*g*j*x0, 4*x0*x1, b*c*f*x1] +) + +@XFAIL +def test_powers(): + assert cse(x*y**2 + x*y) == ([(x0, x*y)], [x0*y + x0]) + + +def test_issue_4498(): + assert cse(w/(x - y) + z/(y - x), optimizations='basic') == \ + ([], [(w - z)/(x - y)]) + + +def test_issue_4020(): + assert cse(x**5 + x**4 + x**3 + x**2, optimizations='basic') \ + == ([(x0, x**2)], [x0*(x**3 + x + x0 + 1)]) + + +def test_issue_4203(): + assert cse(sin(x**x)/x**x) == ([(x0, x**x)], [sin(x0)/x0]) + + +def test_issue_6263(): + e = Eq(x*(-x + 1) + x*(x - 1), 0) + assert cse(e, optimizations='basic') == ([], [True]) + + +def test_issue_25043(): + c = symbols("c") + x = symbols("x0", real=True) + cse_expr = cse(c*x**2 + c*(x**4 - x**2))[-1][-1] + free = cse_expr.free_symbols + assert len(free) == len({i.name for i in free}) + + +def test_dont_cse_tuples(): + from sympy.core.function import Subs + f = Function("f") + g = Function("g") + + name_val, (expr,) = cse( + Subs(f(x, y), (x, y), (0, 1)) + + Subs(g(x, y), (x, y), (0, 1))) + + assert name_val == [] + assert expr == (Subs(f(x, y), (x, y), (0, 1)) + + Subs(g(x, y), (x, y), (0, 1))) + + name_val, (expr,) = cse( + Subs(f(x, y), (x, y), (0, x + y)) + + Subs(g(x, y), (x, y), (0, x + y))) + + assert name_val == [(x0, x + y)] + assert expr == Subs(f(x, y), (x, y), (0, x0)) + \ + Subs(g(x, y), (x, y), (0, x0)) + + +def test_pow_invpow(): + assert cse(1/x**2 + x**2) == \ + ([(x0, x**2)], [x0 + 1/x0]) + assert cse(x**2 + (1 + 1/x**2)/x**2) == \ + ([(x0, x**2), (x1, 1/x0)], [x0 + x1*(x1 + 1)]) + assert cse(1/x**2 + (1 + 1/x**2)*x**2) == \ + ([(x0, x**2), (x1, 1/x0)], [x0*(x1 + 1) + x1]) + assert cse(cos(1/x**2) + sin(1/x**2)) == \ + ([(x0, x**(-2))], [sin(x0) + cos(x0)]) + assert cse(cos(x**2) + sin(x**2)) == \ + ([(x0, x**2)], [sin(x0) + cos(x0)]) + assert cse(y/(2 + x**2) + z/x**2/y) == \ + ([(x0, x**2)], [y/(x0 + 2) + z/(x0*y)]) + assert cse(exp(x**2) + x**2*cos(1/x**2)) == \ + ([(x0, x**2)], [x0*cos(1/x0) + exp(x0)]) + assert cse((1 + 1/x**2)/x**2) == \ + ([(x0, x**(-2))], [x0*(x0 + 1)]) + assert cse(x**(2*y) + x**(-2*y)) == \ + ([(x0, x**(2*y))], [x0 + 1/x0]) + + +def test_postprocess(): + eq = (x + 1 + exp((x + 1)/(y + 1)) + cos(y + 1)) + assert cse([eq, Eq(x, z + 1), z - 2, (z + 1)*(x + 1)], + postprocess=cse_main.cse_separate) == \ + [[(x0, y + 1), (x2, z + 1), (x, x2), (x1, x + 1)], + [x1 + exp(x1/x0) + cos(x0), z - 2, x1*x2]] + + +def test_issue_4499(): + # previously, this gave 16 constants + from sympy.abc import a, b + B = Function('B') + G = Function('G') + t = Tuple(* + (a, a + S.Half, 2*a, b, 2*a - b + 1, (sqrt(z)/2)**(-2*a + 1)*B(2*a - + b, sqrt(z))*B(b - 1, sqrt(z))*G(b)*G(2*a - b + 1), + sqrt(z)*(sqrt(z)/2)**(-2*a + 1)*B(b, sqrt(z))*B(2*a - b, + sqrt(z))*G(b)*G(2*a - b + 1), sqrt(z)*(sqrt(z)/2)**(-2*a + 1)*B(b - 1, + sqrt(z))*B(2*a - b + 1, sqrt(z))*G(b)*G(2*a - b + 1), + (sqrt(z)/2)**(-2*a + 1)*B(b, sqrt(z))*B(2*a - b + 1, + sqrt(z))*G(b)*G(2*a - b + 1), 1, 0, S.Half, z/2, -b + 1, -2*a + b, + -2*a)) + c = cse(t) + ans = ( + [(x0, 2*a), (x1, -b + x0), (x2, x1 + 1), (x3, b - 1), (x4, sqrt(z)), + (x5, B(x3, x4)), (x6, (x4/2)**(1 - x0)*G(b)*G(x2)), (x7, x6*B(x1, x4)), + (x8, B(b, x4)), (x9, x6*B(x2, x4))], + [(a, a + S.Half, x0, b, x2, x5*x7, x4*x7*x8, x4*x5*x9, x8*x9, + 1, 0, S.Half, z/2, -x3, -x1, -x0)]) + assert ans == c + + +def test_issue_6169(): + r = CRootOf(x**6 - 4*x**5 - 2, 1) + assert cse(r) == ([], [r]) + # and a check that the right thing is done with the new + # mechanism + assert sub_post(sub_pre((-x - y)*z - x - y)) == -z*(x + y) - x - y + + +def test_cse_Indexed(): + len_y = 5 + y = IndexedBase('y', shape=(len_y,)) + x = IndexedBase('x', shape=(len_y,)) + i = Idx('i', len_y-1) + + expr1 = (y[i+1]-y[i])/(x[i+1]-x[i]) + expr2 = 1/(x[i+1]-x[i]) + replacements, reduced_exprs = cse([expr1, expr2]) + assert len(replacements) > 0 + + +def test_cse_MatrixSymbol(): + # MatrixSymbols have non-Basic args, so make sure that works + A = MatrixSymbol("A", 3, 3) + assert cse(A) == ([], [A]) + + n = symbols('n', integer=True) + B = MatrixSymbol("B", n, n) + assert cse(B) == ([], [B]) + + assert cse(A[0] * A[0]) == ([], [A[0]*A[0]]) + + assert cse(A[0,0]*A[0,1] + A[0,0]*A[0,1]*A[0,2]) == ([(x0, A[0, 0]*A[0, 1])], [x0*A[0, 2] + x0]) + +def test_cse_MatrixExpr(): + A = MatrixSymbol('A', 3, 3) + y = MatrixSymbol('y', 3, 1) + + expr1 = (A.T*A).I * A * y + expr2 = (A.T*A) * A * y + replacements, reduced_exprs = cse([expr1, expr2]) + assert len(replacements) > 0 + + replacements, reduced_exprs = cse([expr1 + expr2, expr1]) + assert replacements + + replacements, reduced_exprs = cse([A**2, A + A**2]) + assert replacements + + +def test_Piecewise(): + f = Piecewise((-z + x*y, Eq(y, 0)), (-z - x*y, True)) + ans = cse(f) + actual_ans = ([(x0, x*y)], + [Piecewise((x0 - z, Eq(y, 0)), (-z - x0, True))]) + assert ans == actual_ans + + +def test_ignore_order_terms(): + eq = exp(x).series(x,0,3) + sin(y+x**3) - 1 + assert cse(eq) == ([], [sin(x**3 + y) + x + x**2/2 + O(x**3)]) + + +def test_name_conflict(): + z1 = x0 + y + z2 = x2 + x3 + l = [cos(z1) + z1, cos(z2) + z2, x0 + x2] + substs, reduced = cse(l) + assert [e.subs(reversed(substs)) for e in reduced] == l + + +def test_name_conflict_cust_symbols(): + z1 = x0 + y + z2 = x2 + x3 + l = [cos(z1) + z1, cos(z2) + z2, x0 + x2] + substs, reduced = cse(l, symbols("x:10")) + assert [e.subs(reversed(substs)) for e in reduced] == l + + +def test_symbols_exhausted_error(): + l = cos(x+y)+x+y+cos(w+y)+sin(w+y) + sym = [x, y, z] + with raises(ValueError): + cse(l, symbols=sym) + + +def test_issue_7840(): + # daveknippers' example + C393 = sympify( \ + 'Piecewise((C391 - 1.65, C390 < 0.5), (Piecewise((C391 - 1.65, \ + C391 > 2.35), (C392, True)), True))' + ) + C391 = sympify( \ + 'Piecewise((2.05*C390**(-1.03), C390 < 0.5), (2.5*C390**(-0.625), True))' + ) + C393 = C393.subs('C391',C391) + # simple substitution + sub = {} + sub['C390'] = 0.703451854 + sub['C392'] = 1.01417794 + ss_answer = C393.subs(sub) + # cse + substitutions,new_eqn = cse(C393) + for pair in substitutions: + sub[pair[0].name] = pair[1].subs(sub) + cse_answer = new_eqn[0].subs(sub) + # both methods should be the same + assert ss_answer == cse_answer + + # GitRay's example + expr = sympify( + "Piecewise((Symbol('ON'), Equality(Symbol('mode'), Symbol('ON'))), \ + (Piecewise((Piecewise((Symbol('OFF'), StrictLessThan(Symbol('x'), \ + Symbol('threshold'))), (Symbol('ON'), true)), Equality(Symbol('mode'), \ + Symbol('AUTO'))), (Symbol('OFF'), true)), true))" + ) + substitutions, new_eqn = cse(expr) + # this Piecewise should be exactly the same + assert new_eqn[0] == expr + # there should not be any replacements + assert len(substitutions) < 1 + + +def test_issue_8891(): + for cls in (MutableDenseMatrix, MutableSparseMatrix, + ImmutableDenseMatrix, ImmutableSparseMatrix): + m = cls(2, 2, [x + y, 0, 0, 0]) + res = cse([x + y, m]) + ans = ([(x0, x + y)], [x0, cls([[x0, 0], [0, 0]])]) + assert res == ans + assert isinstance(res[1][-1], cls) + + +def test_issue_11230(): + # a specific test that always failed + a, b, f, k, l, i = symbols('a b f k l i') + p = [a*b*f*k*l, a*i*k**2*l, f*i*k**2*l] + R, C = cse(p) + assert not any(i.is_Mul for a in C for i in a.args) + + # random tests for the issue + from sympy.core.random import choice + from sympy.core.function import expand_mul + s = symbols('a:m') + # 35 Mul tests, none of which should ever fail + ex = [Mul(*[choice(s) for i in range(5)]) for i in range(7)] + for p in subsets(ex, 3): + p = list(p) + R, C = cse(p) + assert not any(i.is_Mul for a in C for i in a.args) + for ri in reversed(R): + for i in range(len(C)): + C[i] = C[i].subs(*ri) + assert p == C + # 35 Add tests, none of which should ever fail + ex = [Add(*[choice(s[:7]) for i in range(5)]) for i in range(7)] + for p in subsets(ex, 3): + p = list(p) + R, C = cse(p) + assert not any(i.is_Add for a in C for i in a.args) + for ri in reversed(R): + for i in range(len(C)): + C[i] = C[i].subs(*ri) + # use expand_mul to handle cases like this: + # p = [a + 2*b + 2*e, 2*b + c + 2*e, b + 2*c + 2*g] + # x0 = 2*(b + e) is identified giving a rebuilt p that + # is now `[a + 2*(b + e), c + 2*(b + e), b + 2*c + 2*g]` + assert p == [expand_mul(i) for i in C] + + +@XFAIL +def test_issue_11577(): + def check(eq): + r, c = cse(eq) + assert eq.count_ops() >= \ + len(r) + sum(i[1].count_ops() for i in r) + \ + count_ops(c) + + eq = x**5*y**2 + x**5*y + x**5 + assert cse(eq) == ( + [(x0, x**4), (x1, x*y)], [x**5 + x0*x1*y + x0*x1]) + # ([(x0, x**5*y)], [x0*y + x0 + x**5]) or + # ([(x0, x**5)], [x0*y**2 + x0*y + x0]) + check(eq) + + eq = x**2/(y + 1)**2 + x/(y + 1) + assert cse(eq) == ( + [(x0, y + 1)], [x**2/x0**2 + x/x0]) + # ([(x0, x/(y + 1))], [x0**2 + x0]) + check(eq) + + +def test_hollow_rejection(): + eq = [x + 3, x + 4] + assert cse(eq) == ([], eq) + + +def test_cse_ignore(): + exprs = [exp(y)*(3*y + 3*sqrt(x+1)), exp(y)*(5*y + 5*sqrt(x+1))] + subst1, red1 = cse(exprs) + assert any(y in sub.free_symbols for _, sub in subst1), "cse failed to identify any term with y" + + subst2, red2 = cse(exprs, ignore=(y,)) # y is not allowed in substitutions + assert not any(y in sub.free_symbols for _, sub in subst2), "Sub-expressions containing y must be ignored" + assert any(sub - sqrt(x + 1) == 0 for _, sub in subst2), "cse failed to identify sqrt(x + 1) as sub-expression" + + +def test_cse_ignore_issue_15002(): + l = [ + w*exp(x)*exp(-z), + exp(y)*exp(x)*exp(-z) + ] + substs, reduced = cse(l, ignore=(x,)) + rl = [e.subs(reversed(substs)) for e in reduced] + assert rl == l + + +def test_cse_unevaluated(): + xp1 = UnevaluatedExpr(x + 1) + # This used to cause RecursionError + [(x0, ue)], [red] = cse([(-1 - xp1) / (1 - xp1)]) + if ue == xp1: + assert red == (-1 - x0) / (1 - x0) + elif ue == -xp1: + assert red == (-1 + x0) / (1 + x0) + else: + msg = f'Expected common subexpression {xp1} or {-xp1}, instead got {ue}' + assert False, msg + + +def test_cse__performance(): + nexprs, nterms = 3, 20 + x = symbols('x:%d' % nterms) + exprs = [ + reduce(add, [x[j]*(-1)**(i+j) for j in range(nterms)]) + for i in range(nexprs) + ] + assert (exprs[0] + exprs[1]).simplify() == 0 + subst, red = cse(exprs) + assert len(subst) > 0, "exprs[0] == -exprs[2], i.e. a CSE" + for i, e in enumerate(red): + assert (e.subs(reversed(subst)) - exprs[i]).simplify() == 0 + + +def test_issue_12070(): + exprs = [x + y, 2 + x + y, x + y + z, 3 + x + y + z] + subst, red = cse(exprs) + assert 6 >= (len(subst) + sum(v.count_ops() for k, v in subst) + + count_ops(red)) + + +def test_issue_13000(): + eq = x/(-4*x**2 + y**2) + cse_eq = cse(eq)[1][0] + assert cse_eq == eq + + +def test_issue_18203(): + eq = CRootOf(x**5 + 11*x - 2, 0) + CRootOf(x**5 + 11*x - 2, 1) + assert cse(eq) == ([], [eq]) + + +def test_unevaluated_mul(): + eq = Mul(x + y, x + y, evaluate=False) + assert cse(eq) == ([(x0, x + y)], [x0**2]) + + +def test_cse_release_variables(): + from sympy.simplify.cse_main import cse_release_variables + _0, _1, _2, _3, _4 = symbols('_:5') + eqs = [(x + y - 1)**2, x, + x + y, (x + y)/(2*x + 1) + (x + y - 1)**2, + (2*x + 1)**(x + y)] + r, e = cse(eqs, postprocess=cse_release_variables) + # this can change in keeping with the intention of the function + assert r, e == ([ + (x0, x + y), (x1, (x0 - 1)**2), (x2, 2*x + 1), + (_3, x0/x2 + x1), (_4, x2**x0), (x2, None), (_0, x1), + (x1, None), (_2, x0), (x0, None), (_1, x)], (_0, _1, _2, _3, _4)) + r.reverse() + r = [(s, v) for s, v in r if v is not None] + assert eqs == [i.subs(r) for i in e] + + +def test_cse_list(): + _cse = lambda x: cse(x, list=False) + assert _cse(x) == ([], x) + assert _cse('x') == ([], 'x') + it = [x] + for c in (list, tuple, set): + assert _cse(c(it)) == ([], c(it)) + #Tuple works different from tuple: + assert _cse(Tuple(*it)) == ([], Tuple(*it)) + d = {x: 1} + assert _cse(d) == ([], d) + +def test_issue_18991(): + A = MatrixSymbol('A', 2, 2) + assert signsimp(-A * A - A) == -A * A - A + + +def test_unevaluated_Mul(): + m = [Mul(1, 2, evaluate=False)] + assert cse(m) == ([], m) + + +def test_cse_matrix_expression_inverse(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + x = Inverse(A) + cse_expr = cse(x) + assert cse_expr == ([], [Inverse(A)]) + + +def test_cse_matrix_expression_matmul_inverse(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + b = ImmutableDenseMatrix(symbols('b:2')) + x = MatMul(Inverse(A), b) + cse_expr = cse(x) + assert cse_expr == ([], [x]) + + +def test_cse_matrix_negate_matrix(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + x = MatMul(S.NegativeOne, A) + cse_expr = cse(x) + assert cse_expr == ([], [x]) + + +def test_cse_matrix_negate_matmul_not_extracted(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + B = ImmutableDenseMatrix(symbols('B:4')).reshape(2, 2) + x = MatMul(S.NegativeOne, A, B) + cse_expr = cse(x) + assert cse_expr == ([], [x]) + + +@XFAIL # No simplification rule for nested associative operations +def test_cse_matrix_nested_matmul_collapsed(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + B = ImmutableDenseMatrix(symbols('B:4')).reshape(2, 2) + x = MatMul(S.NegativeOne, MatMul(A, B)) + cse_expr = cse(x) + assert cse_expr == ([], [MatMul(S.NegativeOne, A, B)]) + + +def test_cse_matrix_optimize_out_single_argument_mul(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + x = MatMul(MatMul(MatMul(A))) + cse_expr = cse(x) + assert cse_expr == ([], [A]) + + +@XFAIL # Multiple simplification passed not supported in CSE +def test_cse_matrix_optimize_out_single_argument_mul_combined(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + x = MatAdd(MatMul(MatMul(MatMul(A))), MatMul(MatMul(A)), MatMul(A), A) + cse_expr = cse(x) + assert cse_expr == ([], [MatMul(4, A)]) + + +def test_cse_matrix_optimize_out_single_argument_add(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + x = MatAdd(MatAdd(MatAdd(MatAdd(A)))) + cse_expr = cse(x) + assert cse_expr == ([], [A]) + + +@XFAIL # Multiple simplification passed not supported in CSE +def test_cse_matrix_optimize_out_single_argument_add_combined(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + x = MatMul(MatAdd(MatAdd(MatAdd(A))), MatAdd(MatAdd(A)), MatAdd(A), A) + cse_expr = cse(x) + assert cse_expr == ([], [MatMul(4, A)]) + + +def test_cse_matrix_expression_matrix_solve(): + A = ImmutableDenseMatrix(symbols('A:4')).reshape(2, 2) + b = ImmutableDenseMatrix(symbols('b:2')) + x = MatrixSolve(A, b) + cse_expr = cse(x) + assert cse_expr == ([], [x]) + + +def test_cse_matrix_matrix_expression(): + X = ImmutableDenseMatrix(symbols('X:4')).reshape(2, 2) + y = ImmutableDenseMatrix(symbols('y:2')) + b = MatMul(Inverse(MatMul(Transpose(X), X)), Transpose(X), y) + cse_expr = cse(b) + x0 = MatrixSymbol('x0', 2, 2) + reduced_expr_expected = MatMul(Inverse(MatMul(x0, X)), x0, y) + assert cse_expr == ([(x0, Transpose(X))], [reduced_expr_expected]) + + +def test_cse_matrix_kalman_filter(): + """Kalman Filter example from Matthew Rocklin's SciPy 2013 talk. + + Talk titled: "Matrix Expressions and BLAS/LAPACK; SciPy 2013 Presentation" + + Video: https://pyvideo.org/scipy-2013/matrix-expressions-and-blaslapack-scipy-2013-pr.html + + Notes + ===== + + Equations are: + + new_mu = mu + Sigma*H.T * (R + H*Sigma*H.T).I * (H*mu - data) + = MatAdd(mu, MatMul(Sigma, Transpose(H), Inverse(MatAdd(R, MatMul(H, Sigma, Transpose(H)))), MatAdd(MatMul(H, mu), MatMul(S.NegativeOne, data)))) + new_Sigma = Sigma - Sigma*H.T * (R + H*Sigma*H.T).I * H * Sigma + = MatAdd(Sigma, MatMul(S.NegativeOne, Sigma, Transpose(H)), Inverse(MatAdd(R, MatMul(H*Sigma*Transpose(H)))), H, Sigma)) + + """ + N = 2 + mu = ImmutableDenseMatrix(symbols(f'mu:{N}')) + Sigma = ImmutableDenseMatrix(symbols(f'Sigma:{N * N}')).reshape(N, N) + H = ImmutableDenseMatrix(symbols(f'H:{N * N}')).reshape(N, N) + R = ImmutableDenseMatrix(symbols(f'R:{N * N}')).reshape(N, N) + data = ImmutableDenseMatrix(symbols(f'data:{N}')) + new_mu = MatAdd(mu, MatMul(Sigma, Transpose(H), Inverse(MatAdd(R, MatMul(H, Sigma, Transpose(H)))), MatAdd(MatMul(H, mu), MatMul(S.NegativeOne, data)))) + new_Sigma = MatAdd(Sigma, MatMul(S.NegativeOne, Sigma, Transpose(H), Inverse(MatAdd(R, MatMul(H, Sigma, Transpose(H)))), H, Sigma)) + cse_expr = cse([new_mu, new_Sigma]) + x0 = MatrixSymbol('x0', N, N) + x1 = MatrixSymbol('x1', N, N) + replacements_expected = [ + (x0, Transpose(H)), + (x1, Inverse(MatAdd(R, MatMul(H, Sigma, x0)))), + ] + reduced_exprs_expected = [ + MatAdd(mu, MatMul(Sigma, x0, x1, MatAdd(MatMul(H, mu), MatMul(S.NegativeOne, data)))), + MatAdd(Sigma, MatMul(S.NegativeOne, Sigma, x0, x1, H, Sigma)), + ] + assert cse_expr == (replacements_expected, reduced_exprs_expected) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_cse_diff.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_cse_diff.py new file mode 100644 index 0000000000000000000000000000000000000000..92b2d3d6bbaafb838a5e75f32a214511a1d39567 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_cse_diff.py @@ -0,0 +1,206 @@ +"""Tests for the ``sympy.simplify._cse_diff.py`` module.""" + +import pytest + +from sympy.core.symbol import (Symbol, symbols) +from sympy.core.numbers import Integer +from sympy.core.function import Function +from sympy.core import Derivative +from sympy.functions.elementary.exponential import exp +from sympy.matrices.immutable import ImmutableDenseMatrix +from sympy.physics.mechanics import dynamicsymbols +from sympy.simplify._cse_diff import (_forward_jacobian, + _remove_cse_from_derivative, + _forward_jacobian_cse, + _forward_jacobian_norm_in_cse_out) +from sympy.simplify.simplify import simplify +from sympy.matrices import Matrix, eye + +from sympy.testing.pytest import raises +from sympy.functions.elementary.trigonometric import (cos, sin, tan) +from sympy.simplify.trigsimp import trigsimp + +from sympy import cse + + +w = Symbol('w') +x = Symbol('x') +y = Symbol('y') +z = Symbol('z') + +q1, q2, q3 = dynamicsymbols('q1 q2 q3') + +# Define the custom functions +k = Function('k')(x, y) +f = Function('f')(k, z) + +zero = Integer(0) +one = Integer(1) +two = Integer(2) +neg_one = Integer(-1) + + +@pytest.mark.parametrize( + 'expr, wrt', + [ + ([zero], [x]), + ([one], [x]), + ([two], [x]), + ([neg_one], [x]), + ([x], [x]), + ([y], [x]), + ([x + y], [x]), + ([x*y], [x]), + ([x**2], [x]), + ([x**y], [x]), + ([exp(x)], [x]), + ([sin(x)], [x]), + ([tan(x)], [x]), + ([zero, one, x, y, x*y, x + y], [x, y]), + ([((x/y) + sin(x/y) - exp(y))*((x/y) - exp(y))], [x, y]), + ([w*tan(y*z)/(x - tan(y*z)), w*x*tan(y*z)/(x - tan(y*z))], [w, x, y, z]), + ([q1**2 + q2, q2**2 + q3, q3**2 + q1], [q1, q2, q3]), + ([f + Derivative(f, x) + k + 2*x], [x]) + ] +) + + +def test_forward_jacobian(expr, wrt): + expr = ImmutableDenseMatrix([expr]).T + wrt = ImmutableDenseMatrix([wrt]).T + jacobian = _forward_jacobian(expr, wrt) + zeros = ImmutableDenseMatrix.zeros(*jacobian.shape) + assert simplify(jacobian - expr.jacobian(wrt)) == zeros + + +def test_process_cse(): + x, y, z = symbols('x y z') + f = Function('f') + k = Function('k') + expr = Matrix([f(k(x,y), z) + Derivative(f(k(x,y), z), x) + k(x,y) + 2*x]) + repl, reduced = cse(expr) + p_repl, p_reduced = _remove_cse_from_derivative(repl, reduced) + + x0 = symbols('x0') + x1 = symbols('x1') + + expected_output = ( + [(x0, k(x, y)), (x1, f(x0, z))], + [Matrix([2 * x + x0 + x1 + Derivative(f(k(x, y), z), x)])] + ) + + assert p_repl == expected_output[0], f"Expected {expected_output[0]}, but got {p_repl}" + assert p_reduced == expected_output[1], f"Expected {expected_output[1]}, but got {p_reduced}" + + +def test_io_matrix_type(): + x, y, z = symbols('x y z') + expr = ImmutableDenseMatrix([ + x * y + y * z + x * y * z, + x ** 2 + y ** 2 + z ** 2, + x * y + x * z + y * z + ]) + wrt = ImmutableDenseMatrix([x, y, z]) + + replacements, reduced_expr = cse(expr) + + # Test _forward_jacobian_core + replacements_core, jacobian_core, precomputed_fs_core = _forward_jacobian_cse(replacements, reduced_expr, wrt) + assert isinstance(jacobian_core[0], type(reduced_expr[0])), "Jacobian should be a Matrix of the same type as the input" + + # Test _forward_jacobian_norm_in_dag_out + replacements_norm, jacobian_norm, precomputed_fs_norm = _forward_jacobian_norm_in_cse_out( + expr, wrt) + assert isinstance(jacobian_norm[0], type(reduced_expr[0])), "Jacobian should be a Matrix of the same type as the input" + + # Test _forward_jacobian + jacobian = _forward_jacobian(expr, wrt) + assert isinstance(jacobian, type(expr)), "Jacobian should be a Matrix of the same type as the input" + + +def test_forward_jacobian_input_output(): + x, y, z = symbols('x y z') + expr = Matrix([ + x * y + y * z + x * y * z, + x ** 2 + y ** 2 + z ** 2, + x * y + x * z + y * z + ]) + wrt = Matrix([x, y, z]) + + replacements, reduced_expr = cse(expr) + + # Test _forward_jacobian_core + replacements_core, jacobian_core, precomputed_fs_core = _forward_jacobian_cse(replacements, reduced_expr, wrt) + assert isinstance(replacements_core, type(replacements)), "Replacements should be a list" + assert isinstance(jacobian_core, type(reduced_expr)), "Jacobian should be a list" + assert isinstance(precomputed_fs_core, list), "Precomputed free symbols should be a list" + assert len(replacements_core) == len(replacements), "Length of replacements does not match" + assert len(jacobian_core) == 1, "Jacobian should have one element" + assert len(precomputed_fs_core) == len(replacements), "Length of precomputed free symbols does not match" + + # Test _forward_jacobian_norm_in_dag_out + replacements_norm, jacobian_norm, precomputed_fs_norm = _forward_jacobian_norm_in_cse_out(expr, wrt) + assert isinstance(replacements_norm, type(replacements)), "Replacements should be a list" + assert isinstance(jacobian_norm, type(reduced_expr)), "Jacobian should be a list" + assert isinstance(precomputed_fs_norm, list), "Precomputed free symbols should be a list" + assert len(replacements_norm) == len(replacements), "Length of replacements does not match" + assert len(jacobian_norm) == 1, "Jacobian should have one element" + assert len(precomputed_fs_norm) == len(replacements), "Length of precomputed free symbols does not match" + + +def test_jacobian_hessian(): + L = Matrix(1, 2, [x**2*y, 2*y**2 + x*y]) + syms = [x, y] + assert _forward_jacobian(L, syms) == Matrix([[2*x*y, x**2], [y, 4*y + x]]) + + L = Matrix(1, 2, [x, x**2*y**3]) + assert _forward_jacobian(L, syms) == Matrix([[1, 0], [2*x*y**3, x**2*3*y**2]]) + + +def test_jacobian_metrics(): + rho, phi = symbols("rho,phi") + X = Matrix([rho * cos(phi), rho * sin(phi)]) + Y = Matrix([rho, phi]) + J = _forward_jacobian(X, Y) + assert J == X.jacobian(Y.T) + assert J == (X.T).jacobian(Y) + assert J == (X.T).jacobian(Y.T) + g = J.T * eye(J.shape[0]) * J + g = g.applyfunc(trigsimp) + assert g == Matrix([[1, 0], [0, rho ** 2]]) + + +def test_jacobian2(): + rho, phi = symbols("rho,phi") + X = Matrix([rho * cos(phi), rho * sin(phi), rho ** 2]) + Y = Matrix([rho, phi]) + J = Matrix([ + [cos(phi), -rho * sin(phi)], + [sin(phi), rho * cos(phi)], + [2 * rho, 0], + ]) + assert _forward_jacobian(X, Y) == J + + +def test_issue_4564(): + X = Matrix([exp(x + y + z), exp(x + y + z), exp(x + y + z)]) + Y = Matrix([x, y, z]) + for i in range(1, 3): + for j in range(1, 3): + X_slice = X[:i, :] + Y_slice = Y[:j, :] + J = _forward_jacobian(X_slice, Y_slice) + assert J.rows == i + assert J.cols == j + for k in range(j): + assert J[:, k] == X_slice + + +def test_nonvectorJacobian(): + X = Matrix([[exp(x + y + z), exp(x + y + z)], + [exp(x + y + z), exp(x + y + z)]]) + raises(TypeError, lambda: _forward_jacobian(X, Matrix([x, y, z]))) + X = X[0, :] + Y = Matrix([[x, y], [x, z]]) + raises(TypeError, lambda: _forward_jacobian(X, Y)) + raises(TypeError, lambda: _forward_jacobian(X, Matrix([[x, y], [x, z]]))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_epathtools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_epathtools.py new file mode 100644 index 0000000000000000000000000000000000000000..a8bb47b2f2ff624077ab9905677b181c587ab5a7 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_epathtools.py @@ -0,0 +1,90 @@ +"""Tests for tools for manipulation of expressions using paths. """ + +from sympy.simplify.epathtools import epath, EPath +from sympy.testing.pytest import raises + +from sympy.core.numbers import E +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.abc import x, y, z, t + + +def test_epath_select(): + expr = [((x, 1, t), 2), ((3, y, 4), z)] + + assert epath("/*", expr) == [((x, 1, t), 2), ((3, y, 4), z)] + assert epath("/*/*", expr) == [(x, 1, t), 2, (3, y, 4), z] + assert epath("/*/*/*", expr) == [x, 1, t, 3, y, 4] + assert epath("/*/*/*/*", expr) == [] + + assert epath("/[:]", expr) == [((x, 1, t), 2), ((3, y, 4), z)] + assert epath("/[:]/[:]", expr) == [(x, 1, t), 2, (3, y, 4), z] + assert epath("/[:]/[:]/[:]", expr) == [x, 1, t, 3, y, 4] + assert epath("/[:]/[:]/[:]/[:]", expr) == [] + + assert epath("/*/[:]", expr) == [(x, 1, t), 2, (3, y, 4), z] + + assert epath("/*/[0]", expr) == [(x, 1, t), (3, y, 4)] + assert epath("/*/[1]", expr) == [2, z] + assert epath("/*/[2]", expr) == [] + + assert epath("/*/int", expr) == [2] + assert epath("/*/Symbol", expr) == [z] + assert epath("/*/tuple", expr) == [(x, 1, t), (3, y, 4)] + assert epath("/*/__iter__?", expr) == [(x, 1, t), (3, y, 4)] + + assert epath("/*/int|tuple", expr) == [(x, 1, t), 2, (3, y, 4)] + assert epath("/*/Symbol|tuple", expr) == [(x, 1, t), (3, y, 4), z] + assert epath("/*/int|Symbol|tuple", expr) == [(x, 1, t), 2, (3, y, 4), z] + + assert epath("/*/int|__iter__?", expr) == [(x, 1, t), 2, (3, y, 4)] + assert epath("/*/Symbol|__iter__?", expr) == [(x, 1, t), (3, y, 4), z] + assert epath( + "/*/int|Symbol|__iter__?", expr) == [(x, 1, t), 2, (3, y, 4), z] + + assert epath("/*/[0]/int", expr) == [1, 3, 4] + assert epath("/*/[0]/Symbol", expr) == [x, t, y] + + assert epath("/*/[0]/int[1:]", expr) == [1, 4] + assert epath("/*/[0]/Symbol[1:]", expr) == [t, y] + + assert epath("/Symbol", x + y + z + 1) == [x, y, z] + assert epath("/*/*/Symbol", t + sin(x + 1) + cos(x + y + E)) == [x, x, y] + + +def test_epath_apply(): + expr = [((x, 1, t), 2), ((3, y, 4), z)] + func = lambda expr: expr**2 + + assert epath("/*", expr, list) == [[(x, 1, t), 2], [(3, y, 4), z]] + + assert epath("/*/[0]", expr, list) == [([x, 1, t], 2), ([3, y, 4], z)] + assert epath("/*/[1]", expr, func) == [((x, 1, t), 4), ((3, y, 4), z**2)] + assert epath("/*/[2]", expr, list) == expr + + assert epath("/*/[0]/int", expr, func) == [((x, 1, t), 2), ((9, y, 16), z)] + assert epath("/*/[0]/Symbol", expr, func) == [((x**2, 1, t**2), 2), + ((3, y**2, 4), z)] + assert epath( + "/*/[0]/int[1:]", expr, func) == [((x, 1, t), 2), ((3, y, 16), z)] + assert epath("/*/[0]/Symbol[1:]", expr, func) == [((x, 1, t**2), + 2), ((3, y**2, 4), z)] + + assert epath("/Symbol", x + y + z + 1, func) == x**2 + y**2 + z**2 + 1 + assert epath("/*/*/Symbol", t + sin(x + 1) + cos(x + y + E), func) == \ + t + sin(x**2 + 1) + cos(x**2 + y**2 + E) + + +def test_EPath(): + assert EPath("/*/[0]")._path == "/*/[0]" + assert EPath(EPath("/*/[0]"))._path == "/*/[0]" + assert isinstance(epath("/*/[0]"), EPath) is True + + assert repr(EPath("/*/[0]")) == "EPath('/*/[0]')" + + raises(ValueError, lambda: EPath("")) + raises(ValueError, lambda: EPath("/")) + raises(ValueError, lambda: EPath("/|x")) + raises(ValueError, lambda: EPath("/[")) + raises(ValueError, lambda: EPath("/[0]%")) + + raises(NotImplementedError, lambda: EPath("Symbol")) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_fu.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_fu.py new file mode 100644 index 0000000000000000000000000000000000000000..2de2126b7333195fceeffe72dc9cb642e7eba9a9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_fu.py @@ -0,0 +1,492 @@ +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.numbers import (I, Rational, pi) +from sympy.core.parameters import evaluate +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol, symbols) +from sympy.functions.elementary.hyperbolic import (cosh, coth, csch, sech, sinh, tanh) +from sympy.functions.elementary.miscellaneous import (root, sqrt) +from sympy.functions.elementary.trigonometric import (cos, cot, csc, sec, sin, tan) +from sympy.simplify.powsimp import powsimp +from sympy.simplify.fu import ( + L, TR1, TR10, TR10i, TR11, _TR11, TR12, TR12i, TR13, TR14, TR15, TR16, + TR111, TR2, TR2i, TR3, TR4, TR5, TR6, TR7, TR8, TR9, TRmorrie, _TR56 as T, + TRpower, hyper_as_trig, fu, process_common_addends, trig_split, + as_f_sign_1) +from sympy.core.random import verify_numerically +from sympy.abc import a, b, c, x, y, z + + +def test_TR1(): + assert TR1(2*csc(x) + sec(x)) == 1/cos(x) + 2/sin(x) + + +def test_TR2(): + assert TR2(tan(x)) == sin(x)/cos(x) + assert TR2(cot(x)) == cos(x)/sin(x) + assert TR2(tan(tan(x) - sin(x)/cos(x))) == 0 + + +def test_TR2i(): + # just a reminder that ratios of powers only simplify if both + # numerator and denominator satisfy the condition that each + # has a positive base or an integer exponent; e.g. the following, + # at y=-1, x=1/2 gives sqrt(2)*I != -sqrt(2)*I + assert powsimp(2**x/y**x) != (2/y)**x + + assert TR2i(sin(x)/cos(x)) == tan(x) + assert TR2i(sin(x)*sin(y)/cos(x)) == tan(x)*sin(y) + assert TR2i(1/(sin(x)/cos(x))) == 1/tan(x) + assert TR2i(1/(sin(x)*sin(y)/cos(x))) == 1/tan(x)/sin(y) + assert TR2i(sin(x)/2/(cos(x) + 1)) == sin(x)/(cos(x) + 1)/2 + + assert TR2i(sin(x)/2/(cos(x) + 1), half=True) == tan(x/2)/2 + assert TR2i(sin(1)/(cos(1) + 1), half=True) == tan(S.Half) + assert TR2i(sin(2)/(cos(2) + 1), half=True) == tan(1) + assert TR2i(sin(4)/(cos(4) + 1), half=True) == tan(2) + assert TR2i(sin(5)/(cos(5) + 1), half=True) == tan(5*S.Half) + assert TR2i((cos(1) + 1)/sin(1), half=True) == 1/tan(S.Half) + assert TR2i((cos(2) + 1)/sin(2), half=True) == 1/tan(1) + assert TR2i((cos(4) + 1)/sin(4), half=True) == 1/tan(2) + assert TR2i((cos(5) + 1)/sin(5), half=True) == 1/tan(5*S.Half) + assert TR2i((cos(1) + 1)**(-a)*sin(1)**a, half=True) == tan(S.Half)**a + assert TR2i((cos(2) + 1)**(-a)*sin(2)**a, half=True) == tan(1)**a + assert TR2i((cos(4) + 1)**(-a)*sin(4)**a, half=True) == (cos(4) + 1)**(-a)*sin(4)**a + assert TR2i((cos(5) + 1)**(-a)*sin(5)**a, half=True) == (cos(5) + 1)**(-a)*sin(5)**a + assert TR2i((cos(1) + 1)**a*sin(1)**(-a), half=True) == tan(S.Half)**(-a) + assert TR2i((cos(2) + 1)**a*sin(2)**(-a), half=True) == tan(1)**(-a) + assert TR2i((cos(4) + 1)**a*sin(4)**(-a), half=True) == (cos(4) + 1)**a*sin(4)**(-a) + assert TR2i((cos(5) + 1)**a*sin(5)**(-a), half=True) == (cos(5) + 1)**a*sin(5)**(-a) + + i = symbols('i', integer=True) + assert TR2i(((cos(5) + 1)**i*sin(5)**(-i)), half=True) == tan(5*S.Half)**(-i) + assert TR2i(1/((cos(5) + 1)**i*sin(5)**(-i)), half=True) == tan(5*S.Half)**i + + +def test_TR3(): + assert TR3(cos(y - x*(y - x))) == cos(x*(x - y) + y) + assert cos(pi/2 + x) == -sin(x) + assert cos(30*pi/2 + x) == -cos(x) + + for f in (cos, sin, tan, cot, csc, sec): + i = f(pi*Rational(3, 7)) + j = TR3(i) + assert verify_numerically(i, j) and i.func != j.func + + with evaluate(False): + eq = cos(9*pi/22) + assert eq.has(9*pi) and TR3(eq) == sin(pi/11) + + +def test_TR4(): + for i in [0, pi/6, pi/4, pi/3, pi/2]: + with evaluate(False): + eq = cos(i) + assert isinstance(eq, cos) and TR4(eq) == cos(i) + + +def test__TR56(): + h = lambda x: 1 - x + assert T(sin(x)**3, sin, cos, h, 4, False) == sin(x)*(-cos(x)**2 + 1) + assert T(sin(x)**10, sin, cos, h, 4, False) == sin(x)**10 + assert T(sin(x)**6, sin, cos, h, 6, False) == (-cos(x)**2 + 1)**3 + assert T(sin(x)**6, sin, cos, h, 6, True) == sin(x)**6 + assert T(sin(x)**8, sin, cos, h, 10, True) == (-cos(x)**2 + 1)**4 + + # issue 17137 + assert T(sin(x)**I, sin, cos, h, 4, True) == sin(x)**I + assert T(sin(x)**(2*I + 1), sin, cos, h, 4, True) == sin(x)**(2*I + 1) + + +def test_TR5(): + assert TR5(sin(x)**2) == -cos(x)**2 + 1 + assert TR5(sin(x)**-2) == sin(x)**(-2) + assert TR5(sin(x)**4) == (-cos(x)**2 + 1)**2 + + +def test_TR6(): + assert TR6(cos(x)**2) == -sin(x)**2 + 1 + assert TR6(cos(x)**-2) == cos(x)**(-2) + assert TR6(cos(x)**4) == (-sin(x)**2 + 1)**2 + + +def test_TR7(): + assert TR7(cos(x)**2) == cos(2*x)/2 + S.Half + assert TR7(cos(x)**2 + 1) == cos(2*x)/2 + Rational(3, 2) + + +def test_TR8(): + assert TR8(cos(2)*cos(3)) == cos(5)/2 + cos(1)/2 + assert TR8(cos(2)*sin(3)) == sin(5)/2 + sin(1)/2 + assert TR8(sin(2)*sin(3)) == -cos(5)/2 + cos(1)/2 + assert TR8(sin(1)*sin(2)*sin(3)) == sin(4)/4 - sin(6)/4 + sin(2)/4 + assert TR8(cos(2)*cos(3)*cos(4)*cos(5)) == \ + cos(4)/4 + cos(10)/8 + cos(2)/8 + cos(8)/8 + cos(14)/8 + \ + cos(6)/8 + Rational(1, 8) + assert TR8(cos(2)*cos(3)*cos(4)*cos(5)*cos(6)) == \ + cos(10)/8 + cos(4)/8 + 3*cos(2)/16 + cos(16)/16 + cos(8)/8 + \ + cos(14)/16 + cos(20)/16 + cos(12)/16 + Rational(1, 16) + cos(6)/8 + assert TR8(sin(pi*Rational(3, 7))**2*cos(pi*Rational(3, 7))**2/(16*sin(pi/7)**2)) == Rational(1, 64) + +def test_TR9(): + a = S.Half + b = 3*a + assert TR9(a) == a + assert TR9(cos(1) + cos(2)) == 2*cos(a)*cos(b) + assert TR9(cos(1) - cos(2)) == 2*sin(a)*sin(b) + assert TR9(sin(1) - sin(2)) == -2*sin(a)*cos(b) + assert TR9(sin(1) + sin(2)) == 2*sin(b)*cos(a) + assert TR9(cos(1) + 2*sin(1) + 2*sin(2)) == cos(1) + 4*sin(b)*cos(a) + assert TR9(cos(4) + cos(2) + 2*cos(1)*cos(3)) == 4*cos(1)*cos(3) + assert TR9((cos(4) + cos(2))/cos(3)/2 + cos(3)) == 2*cos(1)*cos(2) + assert TR9(cos(3) + cos(4) + cos(5) + cos(6)) == \ + 4*cos(S.Half)*cos(1)*cos(Rational(9, 2)) + assert TR9(cos(3) + cos(3)*cos(2)) == cos(3) + cos(2)*cos(3) + assert TR9(-cos(y) + cos(x*y)) == -2*sin(x*y/2 - y/2)*sin(x*y/2 + y/2) + assert TR9(-sin(y) + sin(x*y)) == 2*sin(x*y/2 - y/2)*cos(x*y/2 + y/2) + c = cos(x) + s = sin(x) + for si in ((1, 1), (1, -1), (-1, 1), (-1, -1)): + for a in ((c, s), (s, c), (cos(x), cos(x*y)), (sin(x), sin(x*y))): + args = zip(si, a) + ex = Add(*[Mul(*ai) for ai in args]) + t = TR9(ex) + assert not (a[0].func == a[1].func and ( + not verify_numerically(ex, t.expand(trig=True)) or t.is_Add) + or a[1].func != a[0].func and ex != t) + + +def test_TR10(): + assert TR10(cos(a + b)) == -sin(a)*sin(b) + cos(a)*cos(b) + assert TR10(sin(a + b)) == sin(a)*cos(b) + sin(b)*cos(a) + assert TR10(sin(a + b + c)) == \ + (-sin(a)*sin(b) + cos(a)*cos(b))*sin(c) + \ + (sin(a)*cos(b) + sin(b)*cos(a))*cos(c) + assert TR10(cos(a + b + c)) == \ + (-sin(a)*sin(b) + cos(a)*cos(b))*cos(c) - \ + (sin(a)*cos(b) + sin(b)*cos(a))*sin(c) + + +def test_TR10i(): + assert TR10i(cos(1)*cos(3) + sin(1)*sin(3)) == cos(2) + assert TR10i(cos(1)*cos(3) - sin(1)*sin(3)) == cos(4) + assert TR10i(cos(1)*sin(3) - sin(1)*cos(3)) == sin(2) + assert TR10i(cos(1)*sin(3) + sin(1)*cos(3)) == sin(4) + assert TR10i(cos(1)*sin(3) + sin(1)*cos(3) + 7) == sin(4) + 7 + assert TR10i(cos(1)*sin(3) + sin(1)*cos(3) + cos(3)) == cos(3) + sin(4) + assert TR10i(2*cos(1)*sin(3) + 2*sin(1)*cos(3) + cos(3)) == \ + 2*sin(4) + cos(3) + assert TR10i(cos(2)*cos(3) + sin(2)*(cos(1)*sin(2) + cos(2)*sin(1))) == \ + cos(1) + eq = (cos(2)*cos(3) + sin(2)*( + cos(1)*sin(2) + cos(2)*sin(1)))*cos(5) + sin(1)*sin(5) + assert TR10i(eq) == TR10i(eq.expand()) == cos(4) + assert TR10i(sqrt(2)*cos(x)*x + sqrt(6)*sin(x)*x) == \ + 2*sqrt(2)*x*sin(x + pi/6) + assert TR10i(cos(x)/sqrt(6) + sin(x)/sqrt(2) + + cos(x)/sqrt(6)/3 + sin(x)/sqrt(2)/3) == 4*sqrt(6)*sin(x + pi/6)/9 + assert TR10i(cos(x)/sqrt(6) + sin(x)/sqrt(2) + + cos(y)/sqrt(6)/3 + sin(y)/sqrt(2)/3) == \ + sqrt(6)*sin(x + pi/6)/3 + sqrt(6)*sin(y + pi/6)/9 + assert TR10i(cos(x) + sqrt(3)*sin(x) + 2*sqrt(3)*cos(x + pi/6)) == 4*cos(x) + assert TR10i(cos(x) + sqrt(3)*sin(x) + + 2*sqrt(3)*cos(x + pi/6) + 4*sin(x)) == 4*sqrt(2)*sin(x + pi/4) + assert TR10i(cos(2)*sin(3) + sin(2)*cos(4)) == \ + sin(2)*cos(4) + sin(3)*cos(2) + + A = Symbol('A', commutative=False) + assert TR10i(sqrt(2)*cos(x)*A + sqrt(6)*sin(x)*A) == \ + 2*sqrt(2)*sin(x + pi/6)*A + + + c = cos(x) + s = sin(x) + h = sin(y) + r = cos(y) + for si in ((1, 1), (1, -1), (-1, 1), (-1, -1)): + for argsi in ((c*r, s*h), (c*h, s*r)): # explicit 2-args + args = zip(si, argsi) + ex = Add(*[Mul(*ai) for ai in args]) + t = TR10i(ex) + assert not (ex - t.expand(trig=True) or t.is_Add) + + c = cos(x) + s = sin(x) + h = sin(pi/6) + r = cos(pi/6) + for si in ((1, 1), (1, -1), (-1, 1), (-1, -1)): + for argsi in ((c*r, s*h), (c*h, s*r)): # induced + args = zip(si, argsi) + ex = Add(*[Mul(*ai) for ai in args]) + t = TR10i(ex) + assert not (ex - t.expand(trig=True) or t.is_Add) + + +def test_TR11(): + + assert TR11(sin(2*x)) == 2*sin(x)*cos(x) + assert TR11(sin(4*x)) == 4*((-sin(x)**2 + cos(x)**2)*sin(x)*cos(x)) + assert TR11(sin(x*Rational(4, 3))) == \ + 4*((-sin(x/3)**2 + cos(x/3)**2)*sin(x/3)*cos(x/3)) + + assert TR11(cos(2*x)) == -sin(x)**2 + cos(x)**2 + assert TR11(cos(4*x)) == \ + (-sin(x)**2 + cos(x)**2)**2 - 4*sin(x)**2*cos(x)**2 + + assert TR11(cos(2)) == cos(2) + + assert TR11(cos(pi*Rational(3, 7)), pi*Rational(2, 7)) == -cos(pi*Rational(2, 7))**2 + sin(pi*Rational(2, 7))**2 + assert TR11(cos(4), 2) == -sin(2)**2 + cos(2)**2 + assert TR11(cos(6), 2) == cos(6) + assert TR11(sin(x)/cos(x/2), x/2) == 2*sin(x/2) + +def test__TR11(): + + assert _TR11(sin(x/3)*sin(2*x)*sin(x/4)/(cos(x/6)*cos(x/8))) == \ + 4*sin(x/8)*sin(x/6)*sin(2*x),_TR11(sin(x/3)*sin(2*x)*sin(x/4)/(cos(x/6)*cos(x/8))) + assert _TR11(sin(x/3)/cos(x/6)) == 2*sin(x/6) + + assert _TR11(cos(x/6)/sin(x/3)) == 1/(2*sin(x/6)) + assert _TR11(sin(2*x)*cos(x/8)/sin(x/4)) == sin(2*x)/(2*sin(x/8)), _TR11(sin(2*x)*cos(x/8)/sin(x/4)) + assert _TR11(sin(x)/sin(x/2)) == 2*cos(x/2) + + +def test_TR12(): + assert TR12(tan(x + y)) == (tan(x) + tan(y))/(-tan(x)*tan(y) + 1) + assert TR12(tan(x + y + z)) ==\ + (tan(z) + (tan(x) + tan(y))/(-tan(x)*tan(y) + 1))/( + 1 - (tan(x) + tan(y))*tan(z)/(-tan(x)*tan(y) + 1)) + assert TR12(tan(x*y)) == tan(x*y) + + +def test_TR13(): + assert TR13(tan(3)*tan(2)) == -tan(2)/tan(5) - tan(3)/tan(5) + 1 + assert TR13(cot(3)*cot(2)) == 1 + cot(3)*cot(5) + cot(2)*cot(5) + assert TR13(tan(1)*tan(2)*tan(3)) == \ + (-tan(2)/tan(5) - tan(3)/tan(5) + 1)*tan(1) + assert TR13(tan(1)*tan(2)*cot(3)) == \ + (-tan(2)/tan(3) + 1 - tan(1)/tan(3))*cot(3) + + +def test_L(): + assert L(cos(x) + sin(x)) == 2 + + +def test_fu(): + + assert fu(sin(50)**2 + cos(50)**2 + sin(pi/6)) == Rational(3, 2) + assert fu(sqrt(6)*cos(x) + sqrt(2)*sin(x)) == 2*sqrt(2)*sin(x + pi/3) + + + eq = sin(x)**4 - cos(y)**2 + sin(y)**2 + 2*cos(x)**2 + assert fu(eq) == cos(x)**4 - 2*cos(y)**2 + 2 + + assert fu(S.Half - cos(2*x)/2) == sin(x)**2 + + assert fu(sin(a)*(cos(b) - sin(b)) + cos(a)*(sin(b) + cos(b))) == \ + sqrt(2)*sin(a + b + pi/4) + + assert fu(sqrt(3)*cos(x)/2 + sin(x)/2) == sin(x + pi/3) + + assert fu(1 - sin(2*x)**2/4 - sin(y)**2 - cos(x)**4) == \ + -cos(x)**2 + cos(y)**2 + + assert fu(cos(pi*Rational(4, 9))) == sin(pi/18) + assert fu(cos(pi/9)*cos(pi*Rational(2, 9))*cos(pi*Rational(3, 9))*cos(pi*Rational(4, 9))) == Rational(1, 16) + + assert fu( + tan(pi*Rational(7, 18)) + tan(pi*Rational(5, 18)) - sqrt(3)*tan(pi*Rational(5, 18))*tan(pi*Rational(7, 18))) == \ + -sqrt(3) + + assert fu(tan(1)*tan(2)) == tan(1)*tan(2) + + expr = Mul(*[cos(2**i) for i in range(10)]) + assert fu(expr) == sin(1024)/(1024*sin(1)) + + # issue #18059: + assert fu(cos(x) + sqrt(sin(x)**2)) == cos(x) + sqrt(sin(x)**2) + + assert fu((-14*sin(x)**3 + 35*sin(x) + 6*sqrt(3)*cos(x)**3 + 9*sqrt(3)*cos(x))/((cos(2*x) + 4))) == \ + 7*sin(x) + 3*sqrt(3)*cos(x) + + +def test_objective(): + assert fu(sin(x)/cos(x), measure=lambda x: x.count_ops()) == \ + tan(x) + assert fu(sin(x)/cos(x), measure=lambda x: -x.count_ops()) == \ + sin(x)/cos(x) + + +def test_process_common_addends(): + # this tests that the args are not evaluated as they are given to do + # and that key2 works when key1 is False + do = lambda x: Add(*[i**(i%2) for i in x.args]) + assert process_common_addends(Add(*[1, 2, 3, 4], evaluate=False), do, + key2=lambda x: x%2, key1=False) == 1**1 + 3**1 + 2**0 + 4**0 + + +def test_trig_split(): + assert trig_split(cos(x), cos(y)) == (1, 1, 1, x, y, True) + assert trig_split(2*cos(x), -2*cos(y)) == (2, 1, -1, x, y, True) + assert trig_split(cos(x)*sin(y), cos(y)*sin(y)) == \ + (sin(y), 1, 1, x, y, True) + + assert trig_split(cos(x), -sqrt(3)*sin(x), two=True) == \ + (2, 1, -1, x, pi/6, False) + assert trig_split(cos(x), sin(x), two=True) == \ + (sqrt(2), 1, 1, x, pi/4, False) + assert trig_split(cos(x), -sin(x), two=True) == \ + (sqrt(2), 1, -1, x, pi/4, False) + assert trig_split(sqrt(2)*cos(x), -sqrt(6)*sin(x), two=True) == \ + (2*sqrt(2), 1, -1, x, pi/6, False) + assert trig_split(-sqrt(6)*cos(x), -sqrt(2)*sin(x), two=True) == \ + (-2*sqrt(2), 1, 1, x, pi/3, False) + assert trig_split(cos(x)/sqrt(6), sin(x)/sqrt(2), two=True) == \ + (sqrt(6)/3, 1, 1, x, pi/6, False) + assert trig_split(-sqrt(6)*cos(x)*sin(y), + -sqrt(2)*sin(x)*sin(y), two=True) == \ + (-2*sqrt(2)*sin(y), 1, 1, x, pi/3, False) + + assert trig_split(cos(x), sin(x)) is None + assert trig_split(cos(x), sin(z)) is None + assert trig_split(2*cos(x), -sin(x)) is None + assert trig_split(cos(x), -sqrt(3)*sin(x)) is None + assert trig_split(cos(x)*cos(y), sin(x)*sin(z)) is None + assert trig_split(cos(x)*cos(y), sin(x)*sin(y)) is None + assert trig_split(-sqrt(6)*cos(x), sqrt(2)*sin(x)*sin(y), two=True) is \ + None + + assert trig_split(sqrt(3)*sqrt(x), cos(3), two=True) is None + assert trig_split(sqrt(3)*root(x, 3), sin(3)*cos(2), two=True) is None + assert trig_split(cos(5)*cos(6), cos(7)*sin(5), two=True) is None + + +def test_TRmorrie(): + assert TRmorrie(7*Mul(*[cos(i) for i in range(10)])) == \ + 7*sin(12)*sin(16)*cos(5)*cos(7)*cos(9)/(64*sin(1)*sin(3)) + assert TRmorrie(x) == x + assert TRmorrie(2*x) == 2*x + e = cos(pi/7)*cos(pi*Rational(2, 7))*cos(pi*Rational(4, 7)) + assert TR8(TRmorrie(e)) == Rational(-1, 8) + e = Mul(*[cos(2**i*pi/17) for i in range(1, 17)]) + assert TR8(TR3(TRmorrie(e))) == Rational(1, 65536) + # issue 17063 + eq = cos(x)/cos(x/2) + assert TRmorrie(eq) == eq + # issue #20430 + eq = cos(x/2)*sin(x/2)*cos(x)**3 + assert TRmorrie(eq) == sin(2*x)*cos(x)**2/4 + + +def test_TRpower(): + assert TRpower(1/sin(x)**2) == 1/sin(x)**2 + assert TRpower(cos(x)**3*sin(x/2)**4) == \ + (3*cos(x)/4 + cos(3*x)/4)*(-cos(x)/2 + cos(2*x)/8 + Rational(3, 8)) + for k in range(2, 8): + assert verify_numerically(sin(x)**k, TRpower(sin(x)**k)) + assert verify_numerically(cos(x)**k, TRpower(cos(x)**k)) + + +def test_hyper_as_trig(): + from sympy.simplify.fu import _osborne, _osbornei + + eq = sinh(x)**2 + cosh(x)**2 + t, f = hyper_as_trig(eq) + assert f(fu(t)) == cosh(2*x) + e, f = hyper_as_trig(tanh(x + y)) + assert f(TR12(e)) == (tanh(x) + tanh(y))/(tanh(x)*tanh(y) + 1) + + d = Dummy() + assert _osborne(sinh(x), d) == I*sin(x*d) + assert _osborne(tanh(x), d) == I*tan(x*d) + assert _osborne(coth(x), d) == cot(x*d)/I + assert _osborne(cosh(x), d) == cos(x*d) + assert _osborne(sech(x), d) == sec(x*d) + assert _osborne(csch(x), d) == csc(x*d)/I + for func in (sinh, cosh, tanh, coth, sech, csch): + h = func(pi) + assert _osbornei(_osborne(h, d), d) == h + # /!\ the _osborne functions are not meant to work + # in the o(i(trig, d), d) direction so we just check + # that they work as they are supposed to work + assert _osbornei(cos(x*y + z), y) == cosh(x + z*I) + assert _osbornei(sin(x*y + z), y) == sinh(x + z*I)/I + assert _osbornei(tan(x*y + z), y) == tanh(x + z*I)/I + assert _osbornei(cot(x*y + z), y) == coth(x + z*I)*I + assert _osbornei(sec(x*y + z), y) == sech(x + z*I) + assert _osbornei(csc(x*y + z), y) == csch(x + z*I)*I + + +def test_TR12i(): + ta, tb, tc = [tan(i) for i in (a, b, c)] + assert TR12i((ta + tb)/(-ta*tb + 1)) == tan(a + b) + assert TR12i((ta + tb)/(ta*tb - 1)) == -tan(a + b) + assert TR12i((-ta - tb)/(ta*tb - 1)) == tan(a + b) + eq = (ta + tb)/(-ta*tb + 1)**2*(-3*ta - 3*tc)/(2*(ta*tc - 1)) + assert TR12i(eq.expand()) == \ + -3*tan(a + b)*tan(a + c)/(tan(a) + tan(b) - 1)/2 + assert TR12i(tan(x)/sin(x)) == tan(x)/sin(x) + eq = (ta + cos(2))/(-ta*tb + 1) + assert TR12i(eq) == eq + eq = (ta + tb + 2)**2/(-ta*tb + 1) + assert TR12i(eq) == eq + eq = ta/(-ta*tb + 1) + assert TR12i(eq) == eq + eq = (((ta + tb)*(a + 1)).expand())**2/(ta*tb - 1) + assert TR12i(eq) == -(a + 1)**2*tan(a + b) + + +def test_TR14(): + eq = (cos(x) - 1)*(cos(x) + 1) + ans = -sin(x)**2 + assert TR14(eq) == ans + assert TR14(1/eq) == 1/ans + assert TR14((cos(x) - 1)**2*(cos(x) + 1)**2) == ans**2 + assert TR14((cos(x) - 1)**2*(cos(x) + 1)**3) == ans**2*(cos(x) + 1) + assert TR14((cos(x) - 1)**3*(cos(x) + 1)**2) == ans**2*(cos(x) - 1) + eq = (cos(x) - 1)**y*(cos(x) + 1)**y + assert TR14(eq) == eq + eq = (cos(x) - 2)**y*(cos(x) + 1) + assert TR14(eq) == eq + eq = (tan(x) - 2)**2*(cos(x) + 1) + assert TR14(eq) == eq + i = symbols('i', integer=True) + assert TR14((cos(x) - 1)**i*(cos(x) + 1)**i) == ans**i + assert TR14((sin(x) - 1)**i*(sin(x) + 1)**i) == (-cos(x)**2)**i + # could use extraction in this case + eq = (cos(x) - 1)**(i + 1)*(cos(x) + 1)**i + assert TR14(eq) in [(cos(x) - 1)*ans**i, eq] + + assert TR14((sin(x) - 1)*(sin(x) + 1)) == -cos(x)**2 + p1 = (cos(x) + 1)*(cos(x) - 1) + p2 = (cos(y) - 1)*2*(cos(y) + 1) + p3 = (3*(cos(y) - 1))*(3*(cos(y) + 1)) + assert TR14(p1*p2*p3*(x - 1)) == -18*((x - 1)*sin(x)**2*sin(y)**4) + + +def test_TR15_16_17(): + assert TR15(1 - 1/sin(x)**2) == -cot(x)**2 + assert TR16(1 - 1/cos(x)**2) == -tan(x)**2 + assert TR111(1 - 1/tan(x)**2) == 1 - cot(x)**2 + + +def test_as_f_sign_1(): + assert as_f_sign_1(x + 1) == (1, x, 1) + assert as_f_sign_1(x - 1) == (1, x, -1) + assert as_f_sign_1(-x + 1) == (-1, x, -1) + assert as_f_sign_1(-x - 1) == (-1, x, 1) + assert as_f_sign_1(2*x + 2) == (2, x, 1) + assert as_f_sign_1(x*y - y) == (y, x, -1) + assert as_f_sign_1(-x*y + y) == (-y, x, -1) + + +def test_issue_25590(): + A = Symbol('A', commutative=False) + B = Symbol('B', commutative=False) + + assert TR8(2*cos(x)*sin(x)*B*A) == sin(2*x)*B*A + assert TR13(tan(2)*tan(3)*B*A) == (-tan(2)/tan(5) - tan(3)/tan(5) + 1)*B*A + + # XXX The result may not be optimal than + # sin(2*x)*B*A + cos(x)**2 and may change in the future + assert (2*cos(x)*sin(x)*B*A + cos(x)**2).simplify() == sin(2*x)*B*A + cos(2*x)/2 + S.One/2 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_function.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_function.py new file mode 100644 index 0000000000000000000000000000000000000000..441b9faf1bb3c5e7f2279b2a61066d050e45f773 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_function.py @@ -0,0 +1,54 @@ +""" Unit tests for Hyper_Function""" +from sympy.core import symbols, Dummy, Tuple, S, Rational +from sympy.functions import hyper + +from sympy.simplify.hyperexpand import Hyper_Function + +def test_attrs(): + a, b = symbols('a, b', cls=Dummy) + f = Hyper_Function([2, a], [b]) + assert f.ap == Tuple(2, a) + assert f.bq == Tuple(b) + assert f.args == (Tuple(2, a), Tuple(b)) + assert f.sizes == (2, 1) + +def test_call(): + a, b, x = symbols('a, b, x', cls=Dummy) + f = Hyper_Function([2, a], [b]) + assert f(x) == hyper([2, a], [b], x) + +def test_has(): + a, b, c = symbols('a, b, c', cls=Dummy) + f = Hyper_Function([2, -a], [b]) + assert f.has(a) + assert f.has(Tuple(b)) + assert not f.has(c) + +def test_eq(): + assert Hyper_Function([1], []) == Hyper_Function([1], []) + assert (Hyper_Function([1], []) != Hyper_Function([1], [])) is False + assert Hyper_Function([1], []) != Hyper_Function([2], []) + assert Hyper_Function([1], []) != Hyper_Function([1, 2], []) + assert Hyper_Function([1], []) != Hyper_Function([1], [2]) + +def test_gamma(): + assert Hyper_Function([2, 3], [-1]).gamma == 0 + assert Hyper_Function([-2, -3], [-1]).gamma == 2 + n = Dummy(integer=True) + assert Hyper_Function([-1, n, 1], []).gamma == 1 + assert Hyper_Function([-1, -n, 1], []).gamma == 1 + p = Dummy(integer=True, positive=True) + assert Hyper_Function([-1, p, 1], []).gamma == 1 + assert Hyper_Function([-1, -p, 1], []).gamma == 2 + +def test_suitable_origin(): + assert Hyper_Function((S.Half,), (Rational(3, 2),))._is_suitable_origin() is True + assert Hyper_Function((S.Half,), (S.Half,))._is_suitable_origin() is False + assert Hyper_Function((S.Half,), (Rational(-1, 2),))._is_suitable_origin() is False + assert Hyper_Function((S.Half,), (0,))._is_suitable_origin() is False + assert Hyper_Function((S.Half,), (-1, 1,))._is_suitable_origin() is False + assert Hyper_Function((S.Half, 0), (1,))._is_suitable_origin() is False + assert Hyper_Function((S.Half, 1), + (2, Rational(-2, 3)))._is_suitable_origin() is True + assert Hyper_Function((S.Half, 1), + (2, Rational(-2, 3), Rational(3, 2)))._is_suitable_origin() is True diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_gammasimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_gammasimp.py new file mode 100644 index 0000000000000000000000000000000000000000..e4c73093250b279510e3c2274db22818a9adffd8 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_gammasimp.py @@ -0,0 +1,127 @@ +from sympy.core.function import Function +from sympy.core.numbers import (Rational, pi) +from sympy.core.singleton import S +from sympy.core.symbol import symbols +from sympy.functions.combinatorial.factorials import (rf, binomial, factorial) +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.functions.special.gamma_functions import gamma +from sympy.simplify.gammasimp import gammasimp +from sympy.simplify.powsimp import powsimp +from sympy.simplify.simplify import simplify + +from sympy.abc import x, y, n, k + + +def test_gammasimp(): + R = Rational + + # was part of test_combsimp_gamma() in test_combsimp.py + assert gammasimp(gamma(x)) == gamma(x) + assert gammasimp(gamma(x + 1)/x) == gamma(x) + assert gammasimp(gamma(x)/(x - 1)) == gamma(x - 1) + assert gammasimp(x*gamma(x)) == gamma(x + 1) + assert gammasimp((x + 1)*gamma(x + 1)) == gamma(x + 2) + assert gammasimp(gamma(x + y)*(x + y)) == gamma(x + y + 1) + assert gammasimp(x/gamma(x + 1)) == 1/gamma(x) + assert gammasimp((x + 1)**2/gamma(x + 2)) == (x + 1)/gamma(x + 1) + assert gammasimp(x*gamma(x) + gamma(x + 3)/(x + 2)) == \ + (x + 2)*gamma(x + 1) + + assert gammasimp(gamma(2*x)*x) == gamma(2*x + 1)/2 + assert gammasimp(gamma(2*x)/(x - S.Half)) == 2*gamma(2*x - 1) + + assert gammasimp(gamma(x)*gamma(1 - x)) == pi/sin(pi*x) + assert gammasimp(gamma(x)*gamma(-x)) == -pi/(x*sin(pi*x)) + assert gammasimp(1/gamma(x + 3)/gamma(1 - x)) == \ + sin(pi*x)/(pi*x*(x + 1)*(x + 2)) + + assert gammasimp(factorial(n + 2)) == gamma(n + 3) + assert gammasimp(binomial(n, k)) == \ + gamma(n + 1)/(gamma(k + 1)*gamma(-k + n + 1)) + + assert powsimp(gammasimp( + gamma(x)*gamma(x + S.Half)*gamma(y)/gamma(x + y))) == \ + 2**(-2*x + 1)*sqrt(pi)*gamma(2*x)*gamma(y)/gamma(x + y) + assert gammasimp(1/gamma(x)/gamma(x - Rational(1, 3))/gamma(x + Rational(1, 3))) == \ + 3**(3*x - Rational(3, 2))/(2*pi*gamma(3*x - 1)) + assert simplify( + gamma(S.Half + x/2)*gamma(1 + x/2)/gamma(1 + x)/sqrt(pi)*2**x) == 1 + assert gammasimp(gamma(Rational(-1, 4))*gamma(Rational(-3, 4))) == 16*sqrt(2)*pi/3 + + assert powsimp(gammasimp(gamma(2*x)/gamma(x))) == \ + 2**(2*x - 1)*gamma(x + S.Half)/sqrt(pi) + + # issue 6792 + e = (-gamma(k)*gamma(k + 2) + gamma(k + 1)**2)/gamma(k)**2 + assert gammasimp(e) == -k + assert gammasimp(1/e) == -1/k + e = (gamma(x) + gamma(x + 1))/gamma(x) + assert gammasimp(e) == x + 1 + assert gammasimp(1/e) == 1/(x + 1) + e = (gamma(x) + gamma(x + 2))*(gamma(x - 1) + gamma(x))/gamma(x) + assert gammasimp(e) == (x**2 + x + 1)*gamma(x + 1)/(x - 1) + e = (-gamma(k)*gamma(k + 2) + gamma(k + 1)**2)/gamma(k)**2 + assert gammasimp(e**2) == k**2 + assert gammasimp(e**2/gamma(k + 1)) == k/gamma(k) + a = R(1, 2) + R(1, 3) + b = a + R(1, 3) + assert gammasimp(gamma(2*k)/gamma(k)*gamma(k + a)*gamma(k + b) + ) == 3*2**(2*k + 1)*3**(-3*k - 2)*sqrt(pi)*gamma(3*k + R(3, 2))/2 + + # issue 9699 + assert gammasimp((x + 1)*factorial(x)/gamma(y)) == gamma(x + 2)/gamma(y) + assert gammasimp(rf(x + n, k)*binomial(n, k)).simplify() == Piecewise( + (gamma(n + 1)*gamma(k + n + x)/(gamma(k + 1)*gamma(n + x)*gamma(-k + n + 1)), n > -x), + ((-1)**k*gamma(n + 1)*gamma(-n - x + 1)/(gamma(k + 1)*gamma(-k + n + 1)*gamma(-k - n - x + 1)), True)) + + A, B = symbols('A B', commutative=False) + assert gammasimp(e*B*A) == gammasimp(e)*B*A + + # check iteration + assert gammasimp(gamma(2*k)/gamma(k)*gamma(-k - R(1, 2))) == ( + -2**(2*k + 1)*sqrt(pi)/(2*((2*k + 1)*cos(pi*k)))) + assert gammasimp( + gamma(k)*gamma(k + R(1, 3))*gamma(k + R(2, 3))/gamma(k*R(3, 2))) == ( + 3*2**(3*k + 1)*3**(-3*k - S.Half)*sqrt(pi)*gamma(k*R(3, 2) + S.Half)/2) + + # issue 6153 + assert gammasimp(gamma(Rational(1, 4))/gamma(Rational(5, 4))) == 4 + + # was part of test_combsimp() in test_combsimp.py + assert gammasimp(binomial(n + 2, k + S.Half)) == gamma(n + 3)/ \ + (gamma(k + R(3, 2))*gamma(-k + n + R(5, 2))) + assert gammasimp(binomial(n + 2, k + 2.0)) == \ + gamma(n + 3)/(gamma(k + 3.0)*gamma(-k + n + 1)) + + # issue 11548 + assert gammasimp(binomial(0, x)) == sin(pi*x)/(pi*x) + + e = gamma(n + Rational(1, 3))*gamma(n + R(2, 3)) + assert gammasimp(e) == e + assert gammasimp(gamma(4*n + S.Half)/gamma(2*n - R(3, 4))) == \ + 2**(4*n - R(5, 2))*(8*n - 3)*gamma(2*n + R(3, 4))/sqrt(pi) + + i, m = symbols('i m', integer = True) + e = gamma(exp(i)) + assert gammasimp(e) == e + e = gamma(m + 3) + assert gammasimp(e) == e + e = gamma(m + 1)/(gamma(i + 1)*gamma(-i + m + 1)) + assert gammasimp(e) == e + + p = symbols("p", integer=True, positive=True) + assert gammasimp(gamma(-p + 4)) == gamma(-p + 4) + + +def test_issue_22606(): + fx = Function('f')(x) + eq = x + gamma(y) + # seems like ans should be `eq`, not `(x*y + gamma(y + 1))/y` + ans = gammasimp(eq) + assert gammasimp(eq.subs(x, fx)).subs(fx, x) == ans + assert gammasimp(eq.subs(x, cos(x))).subs(cos(x), x) == ans + assert 1/gammasimp(1/eq) == ans + assert gammasimp(fx.subs(x, eq)).args[0] == ans diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_hyperexpand.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_hyperexpand.py new file mode 100644 index 0000000000000000000000000000000000000000..c703c228a13201de13cfd4c3413fc75a2cf5bdb6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_hyperexpand.py @@ -0,0 +1,1063 @@ +from sympy.core.random import randrange + +from sympy.simplify.hyperexpand import (ShiftA, ShiftB, UnShiftA, UnShiftB, + MeijerShiftA, MeijerShiftB, MeijerShiftC, MeijerShiftD, + MeijerUnShiftA, MeijerUnShiftB, MeijerUnShiftC, + MeijerUnShiftD, + ReduceOrder, reduce_order, apply_operators, + devise_plan, make_derivative_operator, Formula, + hyperexpand, Hyper_Function, G_Function, + reduce_order_meijer, + build_hypergeometric_formula) +from sympy.concrete.summations import Sum +from sympy.core.containers import Tuple +from sympy.core.expr import Expr +from sympy.core.numbers import I +from sympy.core.singleton import S +from sympy.core.symbol import symbols +from sympy.functions.combinatorial.factorials import binomial +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.hyper import (hyper, meijerg) +from sympy.abc import z, a, b, c +from sympy.testing.pytest import XFAIL, raises, slow, tooslow +from sympy.core.random import verify_numerically as tn + +from sympy.core.numbers import (Rational, pi) +from sympy.functions.elementary.exponential import (exp, exp_polar, log) +from sympy.functions.elementary.hyperbolic import atanh +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import (asin, cos, sin) +from sympy.functions.special.bessel import besseli +from sympy.functions.special.error_functions import erf +from sympy.functions.special.gamma_functions import (gamma, lowergamma) + + +def test_branch_bug(): + assert hyperexpand(hyper((Rational(-1, 3), S.Half), (Rational(2, 3), Rational(3, 2)), -z)) == \ + -z**S('1/3')*lowergamma(exp_polar(I*pi)/3, z)/5 \ + + sqrt(pi)*erf(sqrt(z))/(5*sqrt(z)) + assert hyperexpand(meijerg([Rational(7, 6), 1], [], [Rational(2, 3)], [Rational(1, 6), 0], z)) == \ + 2*z**S('2/3')*(2*sqrt(pi)*erf(sqrt(z))/sqrt(z) - 2*lowergamma( + Rational(2, 3), z)/z**S('2/3'))*gamma(Rational(2, 3))/gamma(Rational(5, 3)) + + +def test_hyperexpand(): + # Luke, Y. L. (1969), The Special Functions and Their Approximations, + # Volume 1, section 6.2 + + assert hyperexpand(hyper([], [], z)) == exp(z) + assert hyperexpand(hyper([1, 1], [2], -z)*z) == log(1 + z) + assert hyperexpand(hyper([], [S.Half], -z**2/4)) == cos(z) + assert hyperexpand(z*hyper([], [S('3/2')], -z**2/4)) == sin(z) + assert hyperexpand(hyper([S('1/2'), S('1/2')], [S('3/2')], z**2)*z) \ + == asin(z) + assert isinstance(Sum(binomial(2, z)*z**2, (z, 0, a)).doit(), Expr) + + +def can_do(ap, bq, numerical=True, div=1, lowerplane=False): + r = hyperexpand(hyper(ap, bq, z)) + if r.has(hyper): + return False + if not numerical: + return True + repl = {} + randsyms = r.free_symbols - {z} + while randsyms: + # Only randomly generated parameters are checked. + for n, ai in enumerate(randsyms): + repl[ai] = randcplx(n)/div + if not any(b.is_Integer and b <= 0 for b in Tuple(*bq).subs(repl)): + break + [a, b, c, d] = [2, -1, 3, 1] + if lowerplane: + [a, b, c, d] = [2, -2, 3, -1] + return tn( + hyper(ap, bq, z).subs(repl), + r.replace(exp_polar, exp).subs(repl), + z, a=a, b=b, c=c, d=d) + + +def test_roach(): + # Kelly B. Roach. Meijer G Function Representations. + # Section "Gallery" + assert can_do([S.Half], [Rational(9, 2)]) + assert can_do([], [1, Rational(5, 2), 4]) + assert can_do([Rational(-1, 2), 1, 2], [3, 4]) + assert can_do([Rational(1, 3)], [Rational(-2, 3), Rational(-1, 2), S.Half, 1]) + assert can_do([Rational(-3, 2), Rational(-1, 2)], [Rational(-5, 2), 1]) + assert can_do([Rational(-3, 2), ], [Rational(-1, 2), S.Half]) # shine-integral + assert can_do([Rational(-3, 2), Rational(-1, 2)], [2]) # elliptic integrals + + +@XFAIL +def test_roach_fail(): + assert can_do([Rational(-1, 2), 1], [Rational(1, 4), S.Half, Rational(3, 4)]) # PFDD + assert can_do([Rational(3, 2)], [Rational(5, 2), 5]) # struve function + assert can_do([Rational(-1, 2), S.Half, 1], [Rational(3, 2), Rational(5, 2)]) # polylog, pfdd + assert can_do([1, 2, 3], [S.Half, 4]) # XXX ? + assert can_do([S.Half], [Rational(-1, 3), Rational(-1, 2), Rational(-2, 3)]) # PFDD ? + +# For the long table tests, see end of file + + +def test_polynomial(): + from sympy.core.numbers import oo + assert hyperexpand(hyper([], [-1], z)) is oo + assert hyperexpand(hyper([-2], [-1], z)) is oo + assert hyperexpand(hyper([0, 0], [-1], z)) == 1 + assert can_do([-5, -2, randcplx(), randcplx()], [-10, randcplx()]) + assert hyperexpand(hyper((-1, 1), (-2,), z)) == 1 + z/2 + + +def test_hyperexpand_bases(): + assert hyperexpand(hyper([2], [a], z)) == \ + a + z**(-a + 1)*(-a**2 + 3*a + z*(a - 1) - 2)*exp(z)* \ + lowergamma(a - 1, z) - 1 + # TODO [a+1, aRational(-1, 2)], [2*a] + assert hyperexpand(hyper([1, 2], [3], z)) == -2/z - 2*log(-z + 1)/z**2 + assert hyperexpand(hyper([S.Half, 2], [Rational(3, 2)], z)) == \ + -1/(2*z - 2) + atanh(sqrt(z))/sqrt(z)/2 + assert hyperexpand(hyper([S.Half, S.Half], [Rational(5, 2)], z)) == \ + (-3*z + 3)/4/(z*sqrt(-z + 1)) \ + + (6*z - 3)*asin(sqrt(z))/(4*z**Rational(3, 2)) + assert hyperexpand(hyper([1, 2], [Rational(3, 2)], z)) == -1/(2*z - 2) \ + - asin(sqrt(z))/(sqrt(z)*(2*z - 2)*sqrt(-z + 1)) + assert hyperexpand(hyper([Rational(-1, 2) - 1, 1, 2], [S.Half, 3], z)) == \ + sqrt(z)*(z*Rational(6, 7) - Rational(6, 5))*atanh(sqrt(z)) \ + + (-30*z**2 + 32*z - 6)/35/z - 6*log(-z + 1)/(35*z**2) + assert hyperexpand(hyper([1 + S.Half, 1, 1], [2, 2], z)) == \ + -4*log(sqrt(-z + 1)/2 + S.Half)/z + # TODO hyperexpand(hyper([a], [2*a + 1], z)) + # TODO [S.Half, a], [Rational(3, 2), a+1] + assert hyperexpand(hyper([2], [b, 1], z)) == \ + z**(-b/2 + S.Half)*besseli(b - 1, 2*sqrt(z))*gamma(b) \ + + z**(-b/2 + 1)*besseli(b, 2*sqrt(z))*gamma(b) + # TODO [a], [a - S.Half, 2*a] + + +def test_hyperexpand_parametric(): + assert hyperexpand(hyper([a, S.Half + a], [S.Half], z)) \ + == (1 + sqrt(z))**(-2*a)/2 + (1 - sqrt(z))**(-2*a)/2 + assert hyperexpand(hyper([a, Rational(-1, 2) + a], [2*a], z)) \ + == 2**(2*a - 1)*((-z + 1)**S.Half + 1)**(-2*a + 1) + + +def test_shifted_sum(): + from sympy.simplify.simplify import simplify + assert simplify(hyperexpand(z**4*hyper([2], [3, S('3/2')], -z**2))) \ + == z*sin(2*z) + (-z**2 + S.Half)*cos(2*z) - S.Half + + +def _randrat(): + """ Steer clear of integers. """ + return S(randrange(25) + 10)/50 + + +def randcplx(offset=-1): + """ Polys is not good with real coefficients. """ + return _randrat() + I*_randrat() + I*(1 + offset) + + +@slow +def test_formulae(): + from sympy.simplify.hyperexpand import FormulaCollection + formulae = FormulaCollection().formulae + for formula in formulae: + h = formula.func(formula.z) + rep = {} + for n, sym in enumerate(formula.symbols): + rep[sym] = randcplx(n) + + # NOTE hyperexpand returns truly branched functions. We know we are + # on the main sheet, but numerical evaluation can still go wrong + # (e.g. if exp_polar cannot be evalf'd). + # Just replace all exp_polar by exp, this usually works. + + # first test if the closed-form is actually correct + h = h.subs(rep) + closed_form = formula.closed_form.subs(rep).rewrite('nonrepsmall') + z = formula.z + assert tn(h, closed_form.replace(exp_polar, exp), z) + + # now test the computed matrix + cl = (formula.C * formula.B)[0].subs(rep).rewrite('nonrepsmall') + assert tn(closed_form.replace( + exp_polar, exp), cl.replace(exp_polar, exp), z) + deriv1 = z*formula.B.applyfunc(lambda t: t.rewrite( + 'nonrepsmall')).diff(z) + deriv2 = formula.M * formula.B + for d1, d2 in zip(deriv1, deriv2): + assert tn(d1.subs(rep).replace(exp_polar, exp), + d2.subs(rep).rewrite('nonrepsmall').replace(exp_polar, exp), z) + + +def test_meijerg_formulae(): + from sympy.simplify.hyperexpand import MeijerFormulaCollection + formulae = MeijerFormulaCollection().formulae + for sig in formulae: + for formula in formulae[sig]: + g = meijerg(formula.func.an, formula.func.ap, + formula.func.bm, formula.func.bq, + formula.z) + rep = {} + for sym in formula.symbols: + rep[sym] = randcplx() + + # first test if the closed-form is actually correct + g = g.subs(rep) + closed_form = formula.closed_form.subs(rep) + z = formula.z + assert tn(g, closed_form, z) + + # now test the computed matrix + cl = (formula.C * formula.B)[0].subs(rep) + assert tn(closed_form, cl, z) + deriv1 = z*formula.B.diff(z) + deriv2 = formula.M * formula.B + for d1, d2 in zip(deriv1, deriv2): + assert tn(d1.subs(rep), d2.subs(rep), z) + + +def op(f): + return z*f.diff(z) + + +def test_plan(): + assert devise_plan(Hyper_Function([0], ()), + Hyper_Function([0], ()), z) == [] + with raises(ValueError): + devise_plan(Hyper_Function([1], ()), Hyper_Function((), ()), z) + with raises(ValueError): + devise_plan(Hyper_Function([2], [1]), Hyper_Function([2], [2]), z) + with raises(ValueError): + devise_plan(Hyper_Function([2], []), Hyper_Function([S("1/2")], []), z) + + # We cannot use pi/(10000 + n) because polys is insanely slow. + a1, a2, b1 = (randcplx(n) for n in range(3)) + b1 += 2*I + h = hyper([a1, a2], [b1], z) + + h2 = hyper((a1 + 1, a2), [b1], z) + assert tn(apply_operators(h, + devise_plan(Hyper_Function((a1 + 1, a2), [b1]), + Hyper_Function((a1, a2), [b1]), z), op), + h2, z) + + h2 = hyper((a1 + 1, a2 - 1), [b1], z) + assert tn(apply_operators(h, + devise_plan(Hyper_Function((a1 + 1, a2 - 1), [b1]), + Hyper_Function((a1, a2), [b1]), z), op), + h2, z) + + +def test_plan_derivatives(): + a1, a2, a3 = 1, 2, S('1/2') + b1, b2 = 3, S('5/2') + h = Hyper_Function((a1, a2, a3), (b1, b2)) + h2 = Hyper_Function((a1 + 1, a2 + 1, a3 + 2), (b1 + 1, b2 + 1)) + ops = devise_plan(h2, h, z) + f = Formula(h, z, h(z), []) + deriv = make_derivative_operator(f.M, z) + assert tn((apply_operators(f.C, ops, deriv)*f.B)[0], h2(z), z) + + h2 = Hyper_Function((a1, a2 - 1, a3 - 2), (b1 - 1, b2 - 1)) + ops = devise_plan(h2, h, z) + assert tn((apply_operators(f.C, ops, deriv)*f.B)[0], h2(z), z) + + +def test_reduction_operators(): + a1, a2, b1 = (randcplx(n) for n in range(3)) + h = hyper([a1], [b1], z) + + assert ReduceOrder(2, 0) is None + assert ReduceOrder(2, -1) is None + assert ReduceOrder(1, S('1/2')) is None + + h2 = hyper((a1, a2), (b1, a2), z) + assert tn(ReduceOrder(a2, a2).apply(h, op), h2, z) + + h2 = hyper((a1, a2 + 1), (b1, a2), z) + assert tn(ReduceOrder(a2 + 1, a2).apply(h, op), h2, z) + + h2 = hyper((a2 + 4, a1), (b1, a2), z) + assert tn(ReduceOrder(a2 + 4, a2).apply(h, op), h2, z) + + # test several step order reduction + ap = (a2 + 4, a1, b1 + 1) + bq = (a2, b1, b1) + func, ops = reduce_order(Hyper_Function(ap, bq)) + assert func.ap == (a1,) + assert func.bq == (b1,) + assert tn(apply_operators(h, ops, op), hyper(ap, bq, z), z) + + +def test_shift_operators(): + a1, a2, b1, b2, b3 = (randcplx(n) for n in range(5)) + h = hyper((a1, a2), (b1, b2, b3), z) + + raises(ValueError, lambda: ShiftA(0)) + raises(ValueError, lambda: ShiftB(1)) + + assert tn(ShiftA(a1).apply(h, op), hyper((a1 + 1, a2), (b1, b2, b3), z), z) + assert tn(ShiftA(a2).apply(h, op), hyper((a1, a2 + 1), (b1, b2, b3), z), z) + assert tn(ShiftB(b1).apply(h, op), hyper((a1, a2), (b1 - 1, b2, b3), z), z) + assert tn(ShiftB(b2).apply(h, op), hyper((a1, a2), (b1, b2 - 1, b3), z), z) + assert tn(ShiftB(b3).apply(h, op), hyper((a1, a2), (b1, b2, b3 - 1), z), z) + + +def test_ushift_operators(): + a1, a2, b1, b2, b3 = (randcplx(n) for n in range(5)) + h = hyper((a1, a2), (b1, b2, b3), z) + + raises(ValueError, lambda: UnShiftA((1,), (), 0, z)) + raises(ValueError, lambda: UnShiftB((), (-1,), 0, z)) + raises(ValueError, lambda: UnShiftA((1,), (0, -1, 1), 0, z)) + raises(ValueError, lambda: UnShiftB((0, 1), (1,), 0, z)) + + s = UnShiftA((a1, a2), (b1, b2, b3), 0, z) + assert tn(s.apply(h, op), hyper((a1 - 1, a2), (b1, b2, b3), z), z) + s = UnShiftA((a1, a2), (b1, b2, b3), 1, z) + assert tn(s.apply(h, op), hyper((a1, a2 - 1), (b1, b2, b3), z), z) + + s = UnShiftB((a1, a2), (b1, b2, b3), 0, z) + assert tn(s.apply(h, op), hyper((a1, a2), (b1 + 1, b2, b3), z), z) + s = UnShiftB((a1, a2), (b1, b2, b3), 1, z) + assert tn(s.apply(h, op), hyper((a1, a2), (b1, b2 + 1, b3), z), z) + s = UnShiftB((a1, a2), (b1, b2, b3), 2, z) + assert tn(s.apply(h, op), hyper((a1, a2), (b1, b2, b3 + 1), z), z) + + +def can_do_meijer(a1, a2, b1, b2, numeric=True): + """ + This helper function tries to hyperexpand() the meijer g-function + corresponding to the parameters a1, a2, b1, b2. + It returns False if this expansion still contains g-functions. + If numeric is True, it also tests the so-obtained formula numerically + (at random values) and returns False if the test fails. + Else it returns True. + """ + from sympy.core.function import expand + from sympy.functions.elementary.complexes import unpolarify + r = hyperexpand(meijerg(a1, a2, b1, b2, z)) + if r.has(meijerg): + return False + # NOTE hyperexpand() returns a truly branched function, whereas numerical + # evaluation only works on the main branch. Since we are evaluating on + # the main branch, this should not be a problem, but expressions like + # exp_polar(I*pi/2*x)**a are evaluated incorrectly. We thus have to get + # rid of them. The expand heuristically does this... + r = unpolarify(expand(r, force=True, power_base=True, power_exp=False, + mul=False, log=False, multinomial=False, basic=False)) + + if not numeric: + return True + + repl = {} + for n, ai in enumerate(meijerg(a1, a2, b1, b2, z).free_symbols - {z}): + repl[ai] = randcplx(n) + return tn(meijerg(a1, a2, b1, b2, z).subs(repl), r.subs(repl), z) + + +@slow +def test_meijerg_expand(): + from sympy.simplify.gammasimp import gammasimp + from sympy.simplify.simplify import simplify + # from mpmath docs + assert hyperexpand(meijerg([[], []], [[0], []], -z)) == exp(z) + + assert hyperexpand(meijerg([[1, 1], []], [[1], [0]], z)) == \ + log(z + 1) + assert hyperexpand(meijerg([[1, 1], []], [[1], [1]], z)) == \ + z/(z + 1) + assert hyperexpand(meijerg([[], []], [[S.Half], [0]], (z/2)**2)) \ + == sin(z)/sqrt(pi) + assert hyperexpand(meijerg([[], []], [[0], [S.Half]], (z/2)**2)) \ + == cos(z)/sqrt(pi) + assert can_do_meijer([], [a], [a - 1, a - S.Half], []) + assert can_do_meijer([], [], [a/2], [-a/2], False) # branches... + assert can_do_meijer([a], [b], [a], [b, a - 1]) + + # wikipedia + assert hyperexpand(meijerg([1], [], [], [0], z)) == \ + Piecewise((0, abs(z) < 1), (1, abs(1/z) < 1), + (meijerg([1], [], [], [0], z), True)) + assert hyperexpand(meijerg([], [1], [0], [], z)) == \ + Piecewise((1, abs(z) < 1), (0, abs(1/z) < 1), + (meijerg([], [1], [0], [], z), True)) + + # The Special Functions and their Approximations + assert can_do_meijer([], [], [a + b/2], [a, a - b/2, a + S.Half]) + assert can_do_meijer( + [], [], [a], [b], False) # branches only agree for small z + assert can_do_meijer([], [S.Half], [a], [-a]) + assert can_do_meijer([], [], [a, b], []) + assert can_do_meijer([], [], [a, b], []) + assert can_do_meijer([], [], [a, a + S.Half], [b, b + S.Half]) + assert can_do_meijer([], [], [a, -a], [0, S.Half], False) # dito + assert can_do_meijer([], [], [a, a + S.Half, b, b + S.Half], []) + assert can_do_meijer([S.Half], [], [0], [a, -a]) + assert can_do_meijer([S.Half], [], [a], [0, -a], False) # dito + assert can_do_meijer([], [a - S.Half], [a, b], [a - S.Half], False) + assert can_do_meijer([], [a + S.Half], [a + b, a - b, a], [], False) + assert can_do_meijer([a + S.Half], [], [b, 2*a - b, a], [], False) + + # This for example is actually zero. + assert can_do_meijer([], [], [], [a, b]) + + # Testing a bug: + assert hyperexpand(meijerg([0, 2], [], [], [-1, 1], z)) == \ + Piecewise((0, abs(z) < 1), + (z*(1 - 1/z**2)/2, abs(1/z) < 1), + (meijerg([0, 2], [], [], [-1, 1], z), True)) + + # Test that the simplest possible answer is returned: + assert gammasimp(simplify(hyperexpand( + meijerg([1], [1 - a], [-a/2, -a/2 + S.Half], [], 1/z)))) == \ + -2*sqrt(pi)*(sqrt(z + 1) + 1)**a/a + + # Test that hyper is returned + assert hyperexpand(meijerg([1], [], [a], [0, 0], z)) == hyper( + (a,), (a + 1, a + 1), z*exp_polar(I*pi))*z**a*gamma(a)/gamma(a + 1)**2 + + # Test place option + f = meijerg(((0, 1), ()), ((S.Half,), (0,)), z**2) + assert hyperexpand(f) == sqrt(pi)/sqrt(1 + z**(-2)) + assert hyperexpand(f, place=0) == sqrt(pi)*z/sqrt(z**2 + 1) + + +def test_meijerg_lookup(): + from sympy.functions.special.error_functions import (Ci, Si) + from sympy.functions.special.gamma_functions import uppergamma + assert hyperexpand(meijerg([a], [], [b, a], [], z)) == \ + z**b*exp(z)*gamma(-a + b + 1)*uppergamma(a - b, z) + assert hyperexpand(meijerg([0], [], [0, 0], [], z)) == \ + exp(z)*uppergamma(0, z) + assert can_do_meijer([a], [], [b, a + 1], []) + assert can_do_meijer([a], [], [b + 2, a], []) + assert can_do_meijer([a], [], [b - 2, a], []) + + assert hyperexpand(meijerg([a], [], [a, a, a - S.Half], [], z)) == \ + -sqrt(pi)*z**(a - S.Half)*(2*cos(2*sqrt(z))*(Si(2*sqrt(z)) - pi/2) + - 2*sin(2*sqrt(z))*Ci(2*sqrt(z))) == \ + hyperexpand(meijerg([a], [], [a, a - S.Half, a], [], z)) == \ + hyperexpand(meijerg([a], [], [a - S.Half, a, a], [], z)) + assert can_do_meijer([a - 1], [], [a + 2, a - Rational(3, 2), a + 1], []) + + +@XFAIL +def test_meijerg_expand_fail(): + # These basically test hyper([], [1/2 - a, 1/2 + 1, 1/2], z), + # which is *very* messy. But since the meijer g actually yields a + # sum of bessel functions, things can sometimes be simplified a lot and + # are then put into tables... + assert can_do_meijer([], [], [a + S.Half], [a, a - b/2, a + b/2]) + assert can_do_meijer([], [], [0, S.Half], [a, -a]) + assert can_do_meijer([], [], [3*a - S.Half, a, -a - S.Half], [a - S.Half]) + assert can_do_meijer([], [], [0, a - S.Half, -a - S.Half], [S.Half]) + assert can_do_meijer([], [], [a, b + S.Half, b], [2*b - a]) + assert can_do_meijer([], [], [a, b + S.Half, b, 2*b - a]) + assert can_do_meijer([S.Half], [], [-a, a], [0]) + + +@slow +def test_meijerg(): + # carefully set up the parameters. + # NOTE: this used to fail sometimes. I believe it is fixed, but if you + # hit an inexplicable test failure here, please let me know the seed. + a1, a2 = (randcplx(n) - 5*I - n*I for n in range(2)) + b1, b2 = (randcplx(n) + 5*I + n*I for n in range(2)) + b3, b4, b5, a3, a4, a5 = (randcplx() for n in range(6)) + g = meijerg([a1], [a3, a4], [b1], [b3, b4], z) + + assert ReduceOrder.meijer_minus(3, 4) is None + assert ReduceOrder.meijer_plus(4, 3) is None + + g2 = meijerg([a1, a2], [a3, a4], [b1], [b3, b4, a2], z) + assert tn(ReduceOrder.meijer_plus(a2, a2).apply(g, op), g2, z) + + g2 = meijerg([a1, a2], [a3, a4], [b1], [b3, b4, a2 + 1], z) + assert tn(ReduceOrder.meijer_plus(a2, a2 + 1).apply(g, op), g2, z) + + g2 = meijerg([a1, a2 - 1], [a3, a4], [b1], [b3, b4, a2 + 2], z) + assert tn(ReduceOrder.meijer_plus(a2 - 1, a2 + 2).apply(g, op), g2, z) + + g2 = meijerg([a1], [a3, a4, b2 - 1], [b1, b2 + 2], [b3, b4], z) + assert tn(ReduceOrder.meijer_minus( + b2 + 2, b2 - 1).apply(g, op), g2, z, tol=1e-6) + + # test several-step reduction + an = [a1, a2] + bq = [b3, b4, a2 + 1] + ap = [a3, a4, b2 - 1] + bm = [b1, b2 + 1] + niq, ops = reduce_order_meijer(G_Function(an, ap, bm, bq)) + assert niq.an == (a1,) + assert set(niq.ap) == {a3, a4} + assert niq.bm == (b1,) + assert set(niq.bq) == {b3, b4} + assert tn(apply_operators(g, ops, op), meijerg(an, ap, bm, bq, z), z) + + +def test_meijerg_shift_operators(): + # carefully set up the parameters. XXX this still fails sometimes + a1, a2, a3, a4, a5, b1, b2, b3, b4, b5 = (randcplx(n) for n in range(10)) + g = meijerg([a1], [a3, a4], [b1], [b3, b4], z) + + assert tn(MeijerShiftA(b1).apply(g, op), + meijerg([a1], [a3, a4], [b1 + 1], [b3, b4], z), z) + assert tn(MeijerShiftB(a1).apply(g, op), + meijerg([a1 - 1], [a3, a4], [b1], [b3, b4], z), z) + assert tn(MeijerShiftC(b3).apply(g, op), + meijerg([a1], [a3, a4], [b1], [b3 + 1, b4], z), z) + assert tn(MeijerShiftD(a3).apply(g, op), + meijerg([a1], [a3 - 1, a4], [b1], [b3, b4], z), z) + + s = MeijerUnShiftA([a1], [a3, a4], [b1], [b3, b4], 0, z) + assert tn( + s.apply(g, op), meijerg([a1], [a3, a4], [b1 - 1], [b3, b4], z), z) + + s = MeijerUnShiftC([a1], [a3, a4], [b1], [b3, b4], 0, z) + assert tn( + s.apply(g, op), meijerg([a1], [a3, a4], [b1], [b3 - 1, b4], z), z) + + s = MeijerUnShiftB([a1], [a3, a4], [b1], [b3, b4], 0, z) + assert tn( + s.apply(g, op), meijerg([a1 + 1], [a3, a4], [b1], [b3, b4], z), z) + + s = MeijerUnShiftD([a1], [a3, a4], [b1], [b3, b4], 0, z) + assert tn( + s.apply(g, op), meijerg([a1], [a3 + 1, a4], [b1], [b3, b4], z), z) + + +@slow +def test_meijerg_confluence(): + def t(m, a, b): + from sympy.core.sympify import sympify + a, b = sympify([a, b]) + m_ = m + m = hyperexpand(m) + if not m == Piecewise((a, abs(z) < 1), (b, abs(1/z) < 1), (m_, True)): + return False + if not (m.args[0].args[0] == a and m.args[1].args[0] == b): + return False + z0 = randcplx()/10 + if abs(m.subs(z, z0).n() - a.subs(z, z0).n()).n() > 1e-10: + return False + if abs(m.subs(z, 1/z0).n() - b.subs(z, 1/z0).n()).n() > 1e-10: + return False + return True + + assert t(meijerg([], [1, 1], [0, 0], [], z), -log(z), 0) + assert t(meijerg( + [], [3, 1], [0, 0], [], z), -z**2/4 + z - log(z)/2 - Rational(3, 4), 0) + assert t(meijerg([], [3, 1], [-1, 0], [], z), + z**2/12 - z/2 + log(z)/2 + Rational(1, 4) + 1/(6*z), 0) + assert t(meijerg([], [1, 1, 1, 1], [0, 0, 0, 0], [], z), -log(z)**3/6, 0) + assert t(meijerg([1, 1], [], [], [0, 0], z), 0, -log(1/z)) + assert t(meijerg([1, 1], [2, 2], [1, 1], [0, 0], z), + -z*log(z) + 2*z, -log(1/z) + 2) + assert t(meijerg([S.Half], [1, 1], [0, 0], [Rational(3, 2)], z), log(z)/2 - 1, 0) + + def u(an, ap, bm, bq): + m = meijerg(an, ap, bm, bq, z) + m2 = hyperexpand(m, allow_hyper=True) + if m2.has(meijerg) and not (m2.is_Piecewise and len(m2.args) == 3): + return False + return tn(m, m2, z) + assert u([], [1], [0, 0], []) + assert u([1, 1], [], [], [0]) + assert u([1, 1], [2, 2, 5], [1, 1, 6], [0, 0]) + assert u([1, 1], [2, 2, 5], [1, 1, 6], [0]) + + +def test_meijerg_with_Floats(): + # see issue #10681 + from sympy.polys.domains.realfield import RR + f = meijerg(((3.0, 1), ()), ((Rational(3, 2),), (0,)), z) + a = -2.3632718012073 + g = a*z**Rational(3, 2)*hyper((-0.5, Rational(3, 2)), (Rational(5, 2),), z*exp_polar(I*pi)) + assert RR.almosteq((hyperexpand(f)/g).n(), 1.0, 1e-12) + + +def test_lerchphi(): + from sympy.functions.special.zeta_functions import (lerchphi, polylog) + from sympy.simplify.gammasimp import gammasimp + assert hyperexpand(hyper([1, a], [a + 1], z)/a) == lerchphi(z, 1, a) + assert hyperexpand( + hyper([1, a, a], [a + 1, a + 1], z)/a**2) == lerchphi(z, 2, a) + assert hyperexpand(hyper([1, a, a, a], [a + 1, a + 1, a + 1], z)/a**3) == \ + lerchphi(z, 3, a) + assert hyperexpand(hyper([1] + [a]*10, [a + 1]*10, z)/a**10) == \ + lerchphi(z, 10, a) + assert gammasimp(hyperexpand(meijerg([0, 1 - a], [], [0], + [-a], exp_polar(-I*pi)*z))) == lerchphi(z, 1, a) + assert gammasimp(hyperexpand(meijerg([0, 1 - a, 1 - a], [], [0], + [-a, -a], exp_polar(-I*pi)*z))) == lerchphi(z, 2, a) + assert gammasimp(hyperexpand(meijerg([0, 1 - a, 1 - a, 1 - a], [], [0], + [-a, -a, -a], exp_polar(-I*pi)*z))) == lerchphi(z, 3, a) + + assert hyperexpand(z*hyper([1, 1], [2], z)) == -log(1 + -z) + assert hyperexpand(z*hyper([1, 1, 1], [2, 2], z)) == polylog(2, z) + assert hyperexpand(z*hyper([1, 1, 1, 1], [2, 2, 2], z)) == polylog(3, z) + + assert hyperexpand(hyper([1, a, 1 + S.Half], [a + 1, S.Half], z)) == \ + -2*a/(z - 1) + (-2*a**2 + a)*lerchphi(z, 1, a) + + # Now numerical tests. These make sure reductions etc are carried out + # correctly + + # a rational function (polylog at negative integer order) + assert can_do([2, 2, 2], [1, 1]) + + # NOTE these contain log(1-x) etc ... better make sure we have |z| < 1 + # reduction of order for polylog + assert can_do([1, 1, 1, b + 5], [2, 2, b], div=10) + + # reduction of order for lerchphi + # XXX lerchphi in mpmath is flaky + assert can_do( + [1, a, a, a, b + 5], [a + 1, a + 1, a + 1, b], numerical=False) + + # test a bug + from sympy.functions.elementary.complexes import Abs + assert hyperexpand(hyper([S.Half, S.Half, S.Half, 1], + [Rational(3, 2), Rational(3, 2), Rational(3, 2)], Rational(1, 4))) == \ + Abs(-polylog(3, exp_polar(I*pi)/2) + polylog(3, S.Half)) + + +def test_partial_simp(): + # First test that hypergeometric function formulae work. + a, b, c, d, e = (randcplx() for _ in range(5)) + for func in [Hyper_Function([a, b, c], [d, e]), + Hyper_Function([], [a, b, c, d, e])]: + f = build_hypergeometric_formula(func) + z = f.z + assert f.closed_form == func(z) + deriv1 = f.B.diff(z)*z + deriv2 = f.M*f.B + for func1, func2 in zip(deriv1, deriv2): + assert tn(func1, func2, z) + + # Now test that formulae are partially simplified. + a, b, z = symbols('a b z') + assert hyperexpand(hyper([3, a], [1, b], z)) == \ + (-a*b/2 + a*z/2 + 2*a)*hyper([a + 1], [b], z) \ + + (a*b/2 - 2*a + 1)*hyper([a], [b], z) + assert tn( + hyperexpand(hyper([3, d], [1, e], z)), hyper([3, d], [1, e], z), z) + assert hyperexpand(hyper([3], [1, a, b], z)) == \ + hyper((), (a, b), z) \ + + z*hyper((), (a + 1, b), z)/(2*a) \ + - z*(b - 4)*hyper((), (a + 1, b + 1), z)/(2*a*b) + assert tn( + hyperexpand(hyper([3], [1, d, e], z)), hyper([3], [1, d, e], z), z) + + +def test_hyperexpand_special(): + assert hyperexpand(hyper([a, b], [c], 1)) == \ + gamma(c)*gamma(c - a - b)/gamma(c - a)/gamma(c - b) + assert hyperexpand(hyper([a, b], [1 + a - b], -1)) == \ + gamma(1 + a/2)*gamma(1 + a - b)/gamma(1 + a)/gamma(1 + a/2 - b) + assert hyperexpand(hyper([a, b], [1 + b - a], -1)) == \ + gamma(1 + b/2)*gamma(1 + b - a)/gamma(1 + b)/gamma(1 + b/2 - a) + assert hyperexpand(meijerg([1 - z - a/2], [1 - z + a/2], [b/2], [-b/2], 1)) == \ + gamma(1 - 2*z)*gamma(z + a/2 + b/2)/gamma(1 - z + a/2 - b/2) \ + /gamma(1 - z - a/2 + b/2)/gamma(1 - z + a/2 + b/2) + assert hyperexpand(hyper([a], [b], 0)) == 1 + assert hyper([a], [b], 0) != 0 + + +def test_Mod1_behavior(): + from sympy.core.symbol import Symbol + from sympy.simplify.simplify import simplify + n = Symbol('n', integer=True) + # Note: this should not hang. + assert simplify(hyperexpand(meijerg([1], [], [n + 1], [0], z))) == \ + lowergamma(n + 1, z) + + +@slow +def test_prudnikov_misc(): + assert can_do([1, (3 + I)/2, (3 - I)/2], [Rational(3, 2), 2]) + assert can_do([S.Half, a - 1], [Rational(3, 2), a + 1], lowerplane=True) + assert can_do([], [b + 1]) + assert can_do([a], [a - 1, b + 1]) + + assert can_do([a], [a - S.Half, 2*a]) + assert can_do([a], [a - S.Half, 2*a + 1]) + assert can_do([a], [a - S.Half, 2*a - 1]) + assert can_do([a], [a + S.Half, 2*a]) + assert can_do([a], [a + S.Half, 2*a + 1]) + assert can_do([a], [a + S.Half, 2*a - 1]) + assert can_do([S.Half], [b, 2 - b]) + assert can_do([S.Half], [b, 3 - b]) + assert can_do([1], [2, b]) + + assert can_do([a, a + S.Half], [2*a, b, 2*a - b + 1]) + assert can_do([a, a + S.Half], [S.Half, 2*a, 2*a + S.Half]) + assert can_do([a], [a + 1], lowerplane=True) # lowergamma + + +def test_prudnikov_1(): + # A. P. Prudnikov, Yu. A. Brychkov and O. I. Marichev (1990). + # Integrals and Series: More Special Functions, Vol. 3,. + # Gordon and Breach Science Publisher + + # 7.3.1 + assert can_do([a, -a], [S.Half]) + assert can_do([a, 1 - a], [S.Half]) + assert can_do([a, 1 - a], [Rational(3, 2)]) + assert can_do([a, 2 - a], [S.Half]) + assert can_do([a, 2 - a], [Rational(3, 2)]) + assert can_do([a, 2 - a], [Rational(3, 2)]) + assert can_do([a, a + S.Half], [2*a - 1]) + assert can_do([a, a + S.Half], [2*a]) + assert can_do([a, a + S.Half], [2*a + 1]) + assert can_do([a, a + S.Half], [S.Half]) + assert can_do([a, a + S.Half], [Rational(3, 2)]) + assert can_do([a, a/2 + 1], [a/2]) + assert can_do([1, b], [2]) + assert can_do([1, b], [b + 1], numerical=False) # Lerch Phi + # NOTE: branches are complicated for |z| > 1 + + assert can_do([a], [2*a]) + assert can_do([a], [2*a + 1]) + assert can_do([a], [2*a - 1]) + + +@slow +def test_prudnikov_2(): + h = S.Half + assert can_do([-h, -h], [h]) + assert can_do([-h, h], [3*h]) + assert can_do([-h, h], [5*h]) + assert can_do([-h, h], [7*h]) + assert can_do([-h, 1], [h]) + + for p in [-h, h]: + for n in [-h, h, 1, 3*h, 2, 5*h, 3, 7*h, 4]: + for m in [-h, h, 3*h, 5*h, 7*h]: + assert can_do([p, n], [m]) + for n in [1, 2, 3, 4]: + for m in [1, 2, 3, 4]: + assert can_do([p, n], [m]) + + +def test_prudnikov_3(): + h = S.Half + assert can_do([Rational(1, 4), Rational(3, 4)], [h]) + assert can_do([Rational(1, 4), Rational(3, 4)], [3*h]) + assert can_do([Rational(1, 3), Rational(2, 3)], [3*h]) + assert can_do([Rational(3, 4), Rational(5, 4)], [h]) + assert can_do([Rational(3, 4), Rational(5, 4)], [3*h]) + + +@tooslow +def test_prudnikov_3_slow(): + # XXX: This is marked as tooslow and hence skipped in CI. None of the + # individual cases below fails or hangs. Some cases are slow and the loops + # below generate 280 different cases. Is it really necessary to test all + # 280 cases here? + h = S.Half + for p in [1, 2, 3, 4]: + for n in [-h, h, 1, 3*h, 2, 5*h, 3, 7*h, 4, 9*h]: + for m in [1, 3*h, 2, 5*h, 3, 7*h, 4]: + assert can_do([p, m], [n]) + + +@slow +def test_prudnikov_4(): + h = S.Half + for p in [3*h, 5*h, 7*h]: + for n in [-h, h, 3*h, 5*h, 7*h]: + for m in [3*h, 2, 5*h, 3, 7*h, 4]: + assert can_do([p, m], [n]) + for n in [1, 2, 3, 4]: + for m in [2, 3, 4]: + assert can_do([p, m], [n]) + + +@slow +def test_prudnikov_5(): + h = S.Half + + for p in [1, 2, 3]: + for q in range(p, 4): + for r in [1, 2, 3]: + for s in range(r, 4): + assert can_do([-h, p, q], [r, s]) + + for p in [h, 1, 3*h, 2, 5*h, 3]: + for q in [h, 3*h, 5*h]: + for r in [h, 3*h, 5*h]: + for s in [h, 3*h, 5*h]: + if s <= q and s <= r: + assert can_do([-h, p, q], [r, s]) + + for p in [h, 1, 3*h, 2, 5*h, 3]: + for q in [1, 2, 3]: + for r in [h, 3*h, 5*h]: + for s in [1, 2, 3]: + assert can_do([-h, p, q], [r, s]) + + +@slow +def test_prudnikov_6(): + h = S.Half + + for m in [3*h, 5*h]: + for n in [1, 2, 3]: + for q in [h, 1, 2]: + for p in [1, 2, 3]: + assert can_do([h, q, p], [m, n]) + for q in [1, 2, 3]: + for p in [3*h, 5*h]: + assert can_do([h, q, p], [m, n]) + + for q in [1, 2]: + for p in [1, 2, 3]: + for m in [1, 2, 3]: + for n in [1, 2, 3]: + assert can_do([h, q, p], [m, n]) + + assert can_do([h, h, 5*h], [3*h, 3*h]) + assert can_do([h, 1, 5*h], [3*h, 3*h]) + assert can_do([h, 2, 2], [1, 3]) + + # pages 435 to 457 contain more PFDD and stuff like this + + +@slow +def test_prudnikov_7(): + assert can_do([3], [6]) + + h = S.Half + for n in [h, 3*h, 5*h, 7*h]: + assert can_do([-h], [n]) + for m in [-h, h, 1, 3*h, 2, 5*h, 3, 7*h, 4]: # HERE + for n in [-h, h, 3*h, 5*h, 7*h, 1, 2, 3, 4]: + assert can_do([m], [n]) + + +@slow +def test_prudnikov_8(): + h = S.Half + + # 7.12.2 + for ai in [1, 2, 3]: + for bi in [1, 2, 3]: + for ci in range(1, ai + 1): + for di in [h, 1, 3*h, 2, 5*h, 3]: + assert can_do([ai, bi], [ci, di]) + for bi in [3*h, 5*h]: + for ci in [h, 1, 3*h, 2, 5*h, 3]: + for di in [1, 2, 3]: + assert can_do([ai, bi], [ci, di]) + + for ai in [-h, h, 3*h, 5*h]: + for bi in [1, 2, 3]: + for ci in [h, 1, 3*h, 2, 5*h, 3]: + for di in [1, 2, 3]: + assert can_do([ai, bi], [ci, di]) + for bi in [h, 3*h, 5*h]: + for ci in [h, 3*h, 5*h, 3]: + for di in [h, 1, 3*h, 2, 5*h, 3]: + if ci <= bi: + assert can_do([ai, bi], [ci, di]) + + +def test_prudnikov_9(): + # 7.13.1 [we have a general formula ... so this is a bit pointless] + for i in range(9): + assert can_do([], [(S(i) + 1)/2]) + for i in range(5): + assert can_do([], [-(2*S(i) + 1)/2]) + + +@slow +def test_prudnikov_10(): + # 7.14.2 + h = S.Half + for p in [-h, h, 1, 3*h, 2, 5*h, 3, 7*h, 4]: + for m in [1, 2, 3, 4]: + for n in range(m, 5): + assert can_do([p], [m, n]) + + for p in [1, 2, 3, 4]: + for n in [h, 3*h, 5*h, 7*h]: + for m in [1, 2, 3, 4]: + assert can_do([p], [n, m]) + + for p in [3*h, 5*h, 7*h]: + for m in [h, 1, 2, 5*h, 3, 7*h, 4]: + assert can_do([p], [h, m]) + assert can_do([p], [3*h, m]) + + for m in [h, 1, 2, 5*h, 3, 7*h, 4]: + assert can_do([7*h], [5*h, m]) + + assert can_do([Rational(-1, 2)], [S.Half, S.Half]) # shine-integral shi + + +def test_prudnikov_11(): + # 7.15 + assert can_do([a, a + S.Half], [2*a, b, 2*a - b]) + assert can_do([a, a + S.Half], [Rational(3, 2), 2*a, 2*a - S.Half]) + + assert can_do([Rational(1, 4), Rational(3, 4)], [S.Half, S.Half, 1]) + assert can_do([Rational(5, 4), Rational(3, 4)], [Rational(3, 2), S.Half, 2]) + assert can_do([Rational(5, 4), Rational(3, 4)], [Rational(3, 2), Rational(3, 2), 1]) + assert can_do([Rational(5, 4), Rational(7, 4)], [Rational(3, 2), Rational(5, 2), 2]) + + assert can_do([1, 1], [Rational(3, 2), 2, 2]) # cosh-integral chi + + +def test_prudnikov_12(): + # 7.16 + assert can_do( + [], [a, a + S.Half, 2*a], False) # branches only agree for some z! + assert can_do([], [a, a + S.Half, 2*a + 1], False) # dito + assert can_do([], [S.Half, a, a + S.Half]) + assert can_do([], [Rational(3, 2), a, a + S.Half]) + + assert can_do([], [Rational(1, 4), S.Half, Rational(3, 4)]) + assert can_do([], [S.Half, S.Half, 1]) + assert can_do([], [S.Half, Rational(3, 2), 1]) + assert can_do([], [Rational(3, 4), Rational(3, 2), Rational(5, 4)]) + assert can_do([], [1, 1, Rational(3, 2)]) + assert can_do([], [1, 2, Rational(3, 2)]) + assert can_do([], [1, Rational(3, 2), Rational(3, 2)]) + assert can_do([], [Rational(5, 4), Rational(3, 2), Rational(7, 4)]) + assert can_do([], [2, Rational(3, 2), Rational(3, 2)]) + + +@slow +def test_prudnikov_2F1(): + h = S.Half + # Elliptic integrals + for p in [-h, h]: + for m in [h, 3*h, 5*h, 7*h]: + for n in [1, 2, 3, 4]: + assert can_do([p, m], [n]) + + +@XFAIL +def test_prudnikov_fail_2F1(): + assert can_do([a, b], [b + 1]) # incomplete beta function + assert can_do([-1, b], [c]) # Poly. also -2, -3 etc + + # TODO polys + + # Legendre functions: + assert can_do([a, b], [a + b + S.Half]) + assert can_do([a, b], [a + b - S.Half]) + assert can_do([a, b], [a + b + Rational(3, 2)]) + assert can_do([a, b], [(a + b + 1)/2]) + assert can_do([a, b], [(a + b)/2 + 1]) + assert can_do([a, b], [a - b + 1]) + assert can_do([a, b], [a - b + 2]) + assert can_do([a, b], [2*b]) + assert can_do([a, b], [S.Half]) + assert can_do([a, b], [Rational(3, 2)]) + assert can_do([a, 1 - a], [c]) + assert can_do([a, 2 - a], [c]) + assert can_do([a, 3 - a], [c]) + assert can_do([a, a + S.Half], [c]) + assert can_do([1, b], [c]) + assert can_do([1, b], [Rational(3, 2)]) + + assert can_do([Rational(1, 4), Rational(3, 4)], [1]) + + # PFDD + o = S.One + assert can_do([o/8, 1], [o/8*9]) + assert can_do([o/6, 1], [o/6*7]) + assert can_do([o/6, 1], [o/6*13]) + assert can_do([o/5, 1], [o/5*6]) + assert can_do([o/5, 1], [o/5*11]) + assert can_do([o/4, 1], [o/4*5]) + assert can_do([o/4, 1], [o/4*9]) + assert can_do([o/3, 1], [o/3*4]) + assert can_do([o/3, 1], [o/3*7]) + assert can_do([o/8*3, 1], [o/8*11]) + assert can_do([o/5*2, 1], [o/5*7]) + assert can_do([o/5*2, 1], [o/5*12]) + assert can_do([o/5*3, 1], [o/5*8]) + assert can_do([o/5*3, 1], [o/5*13]) + assert can_do([o/8*5, 1], [o/8*13]) + assert can_do([o/4*3, 1], [o/4*7]) + assert can_do([o/4*3, 1], [o/4*11]) + assert can_do([o/3*2, 1], [o/3*5]) + assert can_do([o/3*2, 1], [o/3*8]) + assert can_do([o/5*4, 1], [o/5*9]) + assert can_do([o/5*4, 1], [o/5*14]) + assert can_do([o/6*5, 1], [o/6*11]) + assert can_do([o/6*5, 1], [o/6*17]) + assert can_do([o/8*7, 1], [o/8*15]) + + +@XFAIL +def test_prudnikov_fail_3F2(): + assert can_do([a, a + Rational(1, 3), a + Rational(2, 3)], [Rational(1, 3), Rational(2, 3)]) + assert can_do([a, a + Rational(1, 3), a + Rational(2, 3)], [Rational(2, 3), Rational(4, 3)]) + assert can_do([a, a + Rational(1, 3), a + Rational(2, 3)], [Rational(4, 3), Rational(5, 3)]) + + # page 421 + assert can_do([a, a + Rational(1, 3), a + Rational(2, 3)], [a*Rational(3, 2), (3*a + 1)/2]) + + # pages 422 ... + assert can_do([Rational(-1, 2), S.Half, S.Half], [1, 1]) # elliptic integrals + assert can_do([Rational(-1, 2), S.Half, 1], [Rational(3, 2), Rational(3, 2)]) + # TODO LOTS more + + # PFDD + assert can_do([Rational(1, 8), Rational(3, 8), 1], [Rational(9, 8), Rational(11, 8)]) + assert can_do([Rational(1, 8), Rational(5, 8), 1], [Rational(9, 8), Rational(13, 8)]) + assert can_do([Rational(1, 8), Rational(7, 8), 1], [Rational(9, 8), Rational(15, 8)]) + assert can_do([Rational(1, 6), Rational(1, 3), 1], [Rational(7, 6), Rational(4, 3)]) + assert can_do([Rational(1, 6), Rational(2, 3), 1], [Rational(7, 6), Rational(5, 3)]) + assert can_do([Rational(1, 6), Rational(2, 3), 1], [Rational(5, 3), Rational(13, 6)]) + assert can_do([S.Half, 1, 1], [Rational(1, 4), Rational(3, 4)]) + # LOTS more + + +@XFAIL +def test_prudnikov_fail_other(): + # 7.11.2 + + # 7.12.1 + assert can_do([1, a], [b, 1 - 2*a + b]) # ??? + + # 7.14.2 + assert can_do([Rational(-1, 2)], [S.Half, 1]) # struve + assert can_do([1], [S.Half, S.Half]) # struve + assert can_do([Rational(1, 4)], [S.Half, Rational(5, 4)]) # PFDD + assert can_do([Rational(3, 4)], [Rational(3, 2), Rational(7, 4)]) # PFDD + assert can_do([1], [Rational(1, 4), Rational(3, 4)]) # PFDD + assert can_do([1], [Rational(3, 4), Rational(5, 4)]) # PFDD + assert can_do([1], [Rational(5, 4), Rational(7, 4)]) # PFDD + # TODO LOTS more + + # 7.15.2 + assert can_do([S.Half, 1], [Rational(3, 4), Rational(5, 4), Rational(3, 2)]) # PFDD + assert can_do([S.Half, 1], [Rational(7, 4), Rational(5, 4), Rational(3, 2)]) # PFDD + + # 7.16.1 + assert can_do([], [Rational(1, 3), S(2/3)]) # PFDD + assert can_do([], [Rational(2, 3), S(4/3)]) # PFDD + assert can_do([], [Rational(5, 3), S(4/3)]) # PFDD + + # XXX this does not *evaluate* right?? + assert can_do([], [a, a + S.Half, 2*a - 1]) + + +def test_bug(): + h = hyper([-1, 1], [z], -1) + assert hyperexpand(h) == (z + 1)/z + + +def test_omgissue_203(): + h = hyper((-5, -3, -4), (-6, -6), 1) + assert hyperexpand(h) == Rational(1, 30) + h = hyper((-6, -7, -5), (-6, -6), 1) + assert hyperexpand(h) == Rational(-1, 6) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_powsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_powsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..61bdc93d052baf4b1e80da8f5864cf22b8fa383e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_powsimp.py @@ -0,0 +1,368 @@ +from sympy.core.function import Function +from sympy.core.mul import Mul +from sympy.core.numbers import (E, I, Rational, oo, pi) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol, symbols) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.miscellaneous import (root, sqrt) +from sympy.functions.elementary.trigonometric import sin +from sympy.functions.special.gamma_functions import gamma +from sympy.functions.special.hyper import hyper +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.simplify.powsimp import (powdenest, powsimp) +from sympy.simplify.simplify import (signsimp, simplify) +from sympy.core.symbol import Str + +from sympy.abc import x, y, z, a, b + + +def test_powsimp(): + x, y, z, n = symbols('x,y,z,n') + f = Function('f') + assert powsimp( 4**x * 2**(-x) * 2**(-x) ) == 1 + assert powsimp( (-4)**x * (-2)**(-x) * 2**(-x) ) == 1 + + assert powsimp( + f(4**x * 2**(-x) * 2**(-x)) ) == f(4**x * 2**(-x) * 2**(-x)) + assert powsimp( f(4**x * 2**(-x) * 2**(-x)), deep=True ) == f(1) + assert exp(x)*exp(y) == exp(x)*exp(y) + assert powsimp(exp(x)*exp(y)) == exp(x + y) + assert powsimp(exp(x)*exp(y)*2**x*2**y) == (2*E)**(x + y) + assert powsimp(exp(x)*exp(y)*2**x*2**y, combine='exp') == \ + exp(x + y)*2**(x + y) + assert powsimp(exp(x)*exp(y)*exp(2)*sin(x) + sin(y) + 2**x*2**y) == \ + exp(2 + x + y)*sin(x) + sin(y) + 2**(x + y) + assert powsimp(sin(exp(x)*exp(y))) == sin(exp(x)*exp(y)) + assert powsimp(sin(exp(x)*exp(y)), deep=True) == sin(exp(x + y)) + assert powsimp(x**2*x**y) == x**(2 + y) + # This should remain factored, because 'exp' with deep=True is supposed + # to act like old automatic exponent combining. + assert powsimp((1 + E*exp(E))*exp(-E), combine='exp', deep=True) == \ + (1 + exp(1 + E))*exp(-E) + assert powsimp((1 + E*exp(E))*exp(-E), deep=True) == \ + (1 + exp(1 + E))*exp(-E) + assert powsimp((1 + E*exp(E))*exp(-E)) == (1 + exp(1 + E))*exp(-E) + assert powsimp((1 + E*exp(E))*exp(-E), combine='exp') == \ + (1 + exp(1 + E))*exp(-E) + assert powsimp((1 + E*exp(E))*exp(-E), combine='base') == \ + (1 + E*exp(E))*exp(-E) + x, y = symbols('x,y', nonnegative=True) + n = Symbol('n', real=True) + assert powsimp(y**n * (y/x)**(-n)) == x**n + assert powsimp(x**(x**(x*y)*y**(x*y))*y**(x**(x*y)*y**(x*y)), deep=True) \ + == (x*y)**(x*y)**(x*y) + assert powsimp(2**(2**(2*x)*x), deep=False) == 2**(2**(2*x)*x) + assert powsimp(2**(2**(2*x)*x), deep=True) == 2**(x*4**x) + assert powsimp( + exp(-x + exp(-x)*exp(-x*log(x))), deep=False, combine='exp') == \ + exp(-x + exp(-x)*exp(-x*log(x))) + assert powsimp( + exp(-x + exp(-x)*exp(-x*log(x))), deep=False, combine='exp') == \ + exp(-x + exp(-x)*exp(-x*log(x))) + assert powsimp((x + y)/(3*z), deep=False, combine='exp') == (x + y)/(3*z) + assert powsimp((x/3 + y/3)/z, deep=True, combine='exp') == (x/3 + y/3)/z + assert powsimp(exp(x)/(1 + exp(x)*exp(y)), deep=True) == \ + exp(x)/(1 + exp(x + y)) + assert powsimp(x*y**(z**x*z**y), deep=True) == x*y**(z**(x + y)) + assert powsimp((z**x*z**y)**x, deep=True) == (z**(x + y))**x + assert powsimp(x*(z**x*z**y)**x, deep=True) == x*(z**(x + y))**x + p = symbols('p', positive=True) + assert powsimp((1/x)**log(2)/x) == (1/x)**(1 + log(2)) + assert powsimp((1/p)**log(2)/p) == p**(-1 - log(2)) + + # coefficient of exponent can only be simplified for positive bases + assert powsimp(2**(2*x)) == 4**x + assert powsimp((-1)**(2*x)) == (-1)**(2*x) + i = symbols('i', integer=True) + assert powsimp((-1)**(2*i)) == 1 + assert powsimp((-1)**(-x)) != (-1)**x # could be 1/((-1)**x), but is not + # force=True overrides assumptions + assert powsimp((-1)**(2*x), force=True) == 1 + + # rational exponents allow combining of negative terms + w, n, m = symbols('w n m', negative=True) + e = i/a # not a rational exponent if `a` is unknown + ex = w**e*n**e*m**e + assert powsimp(ex) == m**(i/a)*n**(i/a)*w**(i/a) + e = i/3 + ex = w**e*n**e*m**e + assert powsimp(ex) == (-1)**i*(-m*n*w)**(i/3) + e = (3 + i)/i + ex = w**e*n**e*m**e + assert powsimp(ex) == (-1)**(3*e)*(-m*n*w)**e + + eq = x**(a*Rational(2, 3)) + # eq != (x**a)**(2/3) (try x = -1 and a = 3 to see) + assert powsimp(eq).exp == eq.exp == a*Rational(2, 3) + # powdenest goes the other direction + assert powsimp(2**(2*x)) == 4**x + + assert powsimp(exp(p/2)) == exp(p/2) + + # issue 6368 + eq = Mul(*[sqrt(Dummy(imaginary=True)) for i in range(3)]) + assert powsimp(eq) == eq and eq.is_Mul + + assert all(powsimp(e) == e for e in (sqrt(x**a), sqrt(x**2))) + + # issue 8836 + assert str( powsimp(exp(I*pi/3)*root(-1,3)) ) == '(-1)**(2/3)' + + # issue 9183 + assert powsimp(-0.1**x) == -0.1**x + + # issue 10095 + assert powsimp((1/(2*E))**oo) == (exp(-1)/2)**oo + + # PR 13131 + eq = sin(2*x)**2*sin(2.0*x)**2 + assert powsimp(eq) == eq + + # issue 14615 + assert powsimp(x**2*y**3*(x*y**2)**Rational(3, 2) + ) == x*y*(x*y**2)**Rational(5, 2) + + #issue 27380 + assert powsimp(1.0**(x+1)/1.0**x) == 1.0 + +def test_powsimp_negated_base(): + assert powsimp((-x + y)/sqrt(x - y)) == -sqrt(x - y) + assert powsimp((-x + y)*(-z + y)/sqrt(x - y)/sqrt(z - y)) == sqrt(x - y)*sqrt(z - y) + p = symbols('p', positive=True) + reps = {p: 2, a: S.Half} + assert powsimp((-p)**a/p**a).subs(reps) == ((-1)**a).subs(reps) + assert powsimp((-p)**a*p**a).subs(reps) == ((-p**2)**a).subs(reps) + n = symbols('n', negative=True) + reps = {p: -2, a: S.Half} + assert powsimp((-n)**a/n**a).subs(reps) == (-1)**(-a).subs(a, S.Half) + assert powsimp((-n)**a*n**a).subs(reps) == ((-n**2)**a).subs(reps) + # if x is 0 then the lhs is 0**a*oo**a which is not (-1)**a + eq = (-x)**a/x**a + assert powsimp(eq) == eq + + +def test_powsimp_nc(): + x, y, z = symbols('x,y,z') + A, B, C = symbols('A B C', commutative=False) + + assert powsimp(A**x*A**y, combine='all') == A**(x + y) + assert powsimp(A**x*A**y, combine='base') == A**x*A**y + assert powsimp(A**x*A**y, combine='exp') == A**(x + y) + + assert powsimp(A**x*B**x, combine='all') == A**x*B**x + assert powsimp(A**x*B**x, combine='base') == A**x*B**x + assert powsimp(A**x*B**x, combine='exp') == A**x*B**x + + assert powsimp(B**x*A**x, combine='all') == B**x*A**x + assert powsimp(B**x*A**x, combine='base') == B**x*A**x + assert powsimp(B**x*A**x, combine='exp') == B**x*A**x + + assert powsimp(A**x*A**y*A**z, combine='all') == A**(x + y + z) + assert powsimp(A**x*A**y*A**z, combine='base') == A**x*A**y*A**z + assert powsimp(A**x*A**y*A**z, combine='exp') == A**(x + y + z) + + assert powsimp(A**x*B**x*C**x, combine='all') == A**x*B**x*C**x + assert powsimp(A**x*B**x*C**x, combine='base') == A**x*B**x*C**x + assert powsimp(A**x*B**x*C**x, combine='exp') == A**x*B**x*C**x + + assert powsimp(B**x*A**x*C**x, combine='all') == B**x*A**x*C**x + assert powsimp(B**x*A**x*C**x, combine='base') == B**x*A**x*C**x + assert powsimp(B**x*A**x*C**x, combine='exp') == B**x*A**x*C**x + + +def test_issue_6440(): + assert powsimp(16*2**a*8**b) == 2**(a + 3*b + 4) + + +def test_powdenest(): + x, y = symbols('x,y') + p, q = symbols('p q', positive=True) + i, j = symbols('i,j', integer=True) + + assert powdenest(x) == x + assert powdenest(x + 2*(x**(a*Rational(2, 3)))**(3*x)) == (x + 2*(x**(a*Rational(2, 3)))**(3*x)) + assert powdenest((exp(a*Rational(2, 3)))**(3*x)) # -X-> (exp(a/3))**(6*x) + assert powdenest((x**(a*Rational(2, 3)))**(3*x)) == ((x**(a*Rational(2, 3)))**(3*x)) + assert powdenest(exp(3*x*log(2))) == 2**(3*x) + assert powdenest(sqrt(p**2)) == p + eq = p**(2*i)*q**(4*i) + assert powdenest(eq) == (p*q**2)**(2*i) + # -X-> (x**x)**i*(x**x)**j == x**(x*(i + j)) + assert powdenest((x**x)**(i + j)) + assert powdenest(exp(3*y*log(x))) == x**(3*y) + assert powdenest(exp(y*(log(a) + log(b)))) == (a*b)**y + assert powdenest(exp(3*(log(a) + log(b)))) == a**3*b**3 + assert powdenest(((x**(2*i))**(3*y))**x) == ((x**(2*i))**(3*y))**x + assert powdenest(((x**(2*i))**(3*y))**x, force=True) == x**(6*i*x*y) + assert powdenest(((x**(a*Rational(2, 3)))**(3*y/i))**x) == \ + (((x**(a*Rational(2, 3)))**(3*y/i))**x) + assert powdenest((x**(2*i)*y**(4*i))**z, force=True) == (x*y**2)**(2*i*z) + assert powdenest((p**(2*i)*q**(4*i))**j) == (p*q**2)**(2*i*j) + e = ((p**(2*a))**(3*y))**x + assert powdenest(e) == e + e = ((x**2*y**4)**a)**(x*y) + assert powdenest(e) == e + e = (((x**2*y**4)**a)**(x*y))**3 + assert powdenest(e) == ((x**2*y**4)**a)**(3*x*y) + assert powdenest((((x**2*y**4)**a)**(x*y)), force=True) == \ + (x*y**2)**(2*a*x*y) + assert powdenest((((x**2*y**4)**a)**(x*y))**3, force=True) == \ + (x*y**2)**(6*a*x*y) + assert powdenest((x**2*y**6)**i) != (x*y**3)**(2*i) + x, y = symbols('x,y', positive=True) + assert powdenest((x**2*y**6)**i) == (x*y**3)**(2*i) + + assert powdenest((x**(i*Rational(2, 3))*y**(i/2))**(2*i)) == (x**Rational(4, 3)*y)**(i**2) + assert powdenest(sqrt(x**(2*i)*y**(6*i))) == (x*y**3)**i + + assert powdenest(4**x) == 2**(2*x) + assert powdenest((4**x)**y) == 2**(2*x*y) + assert powdenest(4**x*y) == 2**(2*x)*y + + +def test_powdenest_polar(): + x, y, z = symbols('x y z', polar=True) + a, b, c = symbols('a b c') + assert powdenest((x*y*z)**a) == x**a*y**a*z**a + assert powdenest((x**a*y**b)**c) == x**(a*c)*y**(b*c) + assert powdenest(((x**a)**b*y**c)**c) == x**(a*b*c)*y**(c**2) + + +def test_issue_5805(): + arg = ((gamma(x)*hyper((), (), x))*pi)**2 + assert powdenest(arg) == (pi*gamma(x)*hyper((), (), x))**2 + assert arg.is_positive is None + + +def test_issue_9324_powsimp_on_matrix_symbol(): + M = MatrixSymbol('M', 10, 10) + expr = powsimp(M, deep=True) + assert expr == M + assert expr.args[0] == Str('M') + + +def test_issue_6367(): + z = -5*sqrt(2)/(2*sqrt(2*sqrt(29) + 29)) + sqrt(-sqrt(29)/29 + S.Half) + assert Mul(*[powsimp(a) for a in Mul.make_args(z.normal())]) == 0 + assert powsimp(z.normal()) == 0 + assert simplify(z) == 0 + assert powsimp(sqrt(2 + sqrt(3))*sqrt(2 - sqrt(3)) + 1) == 2 + assert powsimp(z) != 0 + + +def test_powsimp_polar(): + from sympy.functions.elementary.complexes import polar_lift + from sympy.functions.elementary.exponential import exp_polar + x, y, z = symbols('x y z') + p, q, r = symbols('p q r', polar=True) + + assert (polar_lift(-1))**(2*x) == exp_polar(2*pi*I*x) + assert powsimp(p**x * q**x) == (p*q)**x + assert p**x * (1/p)**x == 1 + assert (1/p)**x == p**(-x) + + assert exp_polar(x)*exp_polar(y) == exp_polar(x)*exp_polar(y) + assert powsimp(exp_polar(x)*exp_polar(y)) == exp_polar(x + y) + assert powsimp(exp_polar(x)*exp_polar(y)*p**x*p**y) == \ + (p*exp_polar(1))**(x + y) + assert powsimp(exp_polar(x)*exp_polar(y)*p**x*p**y, combine='exp') == \ + exp_polar(x + y)*p**(x + y) + assert powsimp( + exp_polar(x)*exp_polar(y)*exp_polar(2)*sin(x) + sin(y) + p**x*p**y) \ + == p**(x + y) + sin(x)*exp_polar(2 + x + y) + sin(y) + assert powsimp(sin(exp_polar(x)*exp_polar(y))) == \ + sin(exp_polar(x)*exp_polar(y)) + assert powsimp(sin(exp_polar(x)*exp_polar(y)), deep=True) == \ + sin(exp_polar(x + y)) + + +def test_issue_5728(): + b = x*sqrt(y) + a = sqrt(b) + c = sqrt(sqrt(x)*y) + assert powsimp(a*b) == sqrt(b)**3 + assert powsimp(a*b**2*sqrt(y)) == sqrt(y)*a**5 + assert powsimp(a*x**2*c**3*y) == c**3*a**5 + assert powsimp(a*x*c**3*y**2) == c**7*a + assert powsimp(x*c**3*y**2) == c**7 + assert powsimp(x*c**3*y) == x*y*c**3 + assert powsimp(sqrt(x)*c**3*y) == c**5 + assert powsimp(sqrt(x)*a**3*sqrt(y)) == sqrt(x)*sqrt(y)*a**3 + assert powsimp(Mul(sqrt(x)*c**3*sqrt(y), y, evaluate=False)) == \ + sqrt(x)*sqrt(y)**3*c**3 + assert powsimp(a**2*a*x**2*y) == a**7 + + # symbolic powers work, too + b = x**y*y + a = b*sqrt(b) + assert a.is_Mul is True + assert powsimp(a) == sqrt(b)**3 + + # as does exp + a = x*exp(y*Rational(2, 3)) + assert powsimp(a*sqrt(a)) == sqrt(a)**3 + assert powsimp(a**2*sqrt(a)) == sqrt(a)**5 + assert powsimp(a**2*sqrt(sqrt(a))) == sqrt(sqrt(a))**9 + + +def test_issue_from_PR1599(): + n1, n2, n3, n4 = symbols('n1 n2 n3 n4', negative=True) + assert (powsimp(sqrt(n1)*sqrt(n2)*sqrt(n3)) == + -I*sqrt(-n1)*sqrt(-n2)*sqrt(-n3)) + assert (powsimp(root(n1, 3)*root(n2, 3)*root(n3, 3)*root(n4, 3)) == + -(-1)**Rational(1, 3)* + (-n1)**Rational(1, 3)*(-n2)**Rational(1, 3)*(-n3)**Rational(1, 3)*(-n4)**Rational(1, 3)) + + +def test_issue_10195(): + a = Symbol('a', integer=True) + l = Symbol('l', even=True, nonzero=True) + n = Symbol('n', odd=True) + e_x = (-1)**(n/2 - S.Half) - (-1)**(n*Rational(3, 2) - S.Half) + assert powsimp((-1)**(l/2)) == I**l + assert powsimp((-1)**(n/2)) == I**n + assert powsimp((-1)**(n*Rational(3, 2))) == -I**n + assert powsimp(e_x) == (-1)**(n/2 - S.Half) + (-1)**(n*Rational(3, 2) + + S.Half) + assert powsimp((-1)**(a*Rational(3, 2))) == (-I)**a + +def test_issue_15709(): + assert powsimp(3**x*Rational(2, 3)) == 2*3**(x-1) + assert powsimp(2*3**x/3) == 2*3**(x-1) + + +def test_issue_11981(): + x, y = symbols('x y', commutative=False) + assert powsimp((x*y)**2 * (y*x)**2) == (x*y)**2 * (y*x)**2 + + +def test_issue_17524(): + a = symbols("a", real=True) + e = (-1 - a**2)*sqrt(1 + a**2) + assert signsimp(powsimp(e)) == signsimp(e) == -(a**2 + 1)**(S(3)/2) + + +def test_issue_19627(): + # if you use force the user must verify + assert powdenest(sqrt(sin(x)**2), force=True) == sin(x) + assert powdenest((x**(S.Half/y))**(2*y), force=True) == x + from sympy.core.function import expand_power_base + e = 1 - a + expr = (exp(z/e)*x**(b/e)*y**((1 - b)/e))**e + assert powdenest(expand_power_base(expr, force=True), force=True + ) == x**b*y**(1 - b)*exp(z) + + +def test_issue_22546(): + p1, p2 = symbols('p1, p2', positive=True) + ref = powsimp(p1**z/p2**z) + e = z + 1 + ans = ref.subs(z, e) + assert ans.is_Pow + assert powsimp(p1**e/p2**e) == ans + i = symbols('i', integer=True) + ref = powsimp(x**i/y**i) + e = i + 1 + ans = ref.subs(i, e) + assert ans.is_Pow + assert powsimp(x**e/y**e) == ans diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_radsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_radsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..f8ff955e48a34536c1752c565c0864dedae6a214 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_radsimp.py @@ -0,0 +1,498 @@ +from sympy.core.add import Add +from sympy.core.function import (Derivative, Function, diff) +from sympy.core.mul import Mul +from sympy.core.numbers import (I, Rational) +from sympy.core.power import Pow +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, Wild, symbols) +from sympy.functions.elementary.complexes import Abs +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.miscellaneous import (root, sqrt) +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.polys.polytools import factor +from sympy.series.order import O +from sympy.simplify.radsimp import (collect, collect_const, fraction, radsimp, rcollect) + +from sympy.core.expr import unchanged +from sympy.core.mul import _unevaluated_Mul as umul +from sympy.simplify.radsimp import (_unevaluated_Add, + collect_sqrt, fraction_expand, collect_abs) +from sympy.testing.pytest import raises + +from sympy.abc import x, y, z, a, b, c, d + + +def test_radsimp(): + r2 = sqrt(2) + r3 = sqrt(3) + r5 = sqrt(5) + r7 = sqrt(7) + assert fraction(radsimp(1/r2)) == (sqrt(2), 2) + assert radsimp(1/(1 + r2)) == \ + -1 + sqrt(2) + assert radsimp(1/(r2 + r3)) == \ + -sqrt(2) + sqrt(3) + assert fraction(radsimp(1/(1 + r2 + r3))) == \ + (-sqrt(6) + sqrt(2) + 2, 4) + assert fraction(radsimp(1/(r2 + r3 + r5))) == \ + (-sqrt(30) + 2*sqrt(3) + 3*sqrt(2), 12) + assert fraction(radsimp(1/(1 + r2 + r3 + r5))) == ( + (-34*sqrt(10) - 26*sqrt(15) - 55*sqrt(3) - 61*sqrt(2) + 14*sqrt(30) + + 93 + 46*sqrt(6) + 53*sqrt(5), 71)) + assert fraction(radsimp(1/(r2 + r3 + r5 + r7))) == ( + (-50*sqrt(42) - 133*sqrt(5) - 34*sqrt(70) - 145*sqrt(3) + 22*sqrt(105) + + 185*sqrt(2) + 62*sqrt(30) + 135*sqrt(7), 215)) + z = radsimp(1/(1 + r2/3 + r3/5 + r5 + r7)) + assert len((3616791619821680643598*z).args) == 16 + assert radsimp(1/z) == 1/z + assert radsimp(1/z, max_terms=20).expand() == 1 + r2/3 + r3/5 + r5 + r7 + assert radsimp(1/(r2*3)) == \ + sqrt(2)/6 + assert radsimp(1/(r2*a + r3 + r5 + r7)) == ( + (8*sqrt(2)*a**7 - 8*sqrt(7)*a**6 - 8*sqrt(5)*a**6 - 8*sqrt(3)*a**6 - + 180*sqrt(2)*a**5 + 8*sqrt(30)*a**5 + 8*sqrt(42)*a**5 + 8*sqrt(70)*a**5 + - 24*sqrt(105)*a**4 + 84*sqrt(3)*a**4 + 100*sqrt(5)*a**4 + + 116*sqrt(7)*a**4 - 72*sqrt(70)*a**3 - 40*sqrt(42)*a**3 - + 8*sqrt(30)*a**3 + 782*sqrt(2)*a**3 - 462*sqrt(3)*a**2 - + 302*sqrt(7)*a**2 - 254*sqrt(5)*a**2 + 120*sqrt(105)*a**2 - + 795*sqrt(2)*a - 62*sqrt(30)*a + 82*sqrt(42)*a + 98*sqrt(70)*a - + 118*sqrt(105) + 59*sqrt(7) + 295*sqrt(5) + 531*sqrt(3))/(16*a**8 - + 480*a**6 + 3128*a**4 - 6360*a**2 + 3481)) + assert radsimp(1/(r2*a + r2*b + r3 + r7)) == ( + (sqrt(2)*a*(a + b)**2 - 5*sqrt(2)*a + sqrt(42)*a + sqrt(2)*b*(a + + b)**2 - 5*sqrt(2)*b + sqrt(42)*b - sqrt(7)*(a + b)**2 - sqrt(3)*(a + + b)**2 - 2*sqrt(3) + 2*sqrt(7))/(2*a**4 + 8*a**3*b + 12*a**2*b**2 - + 20*a**2 + 8*a*b**3 - 40*a*b + 2*b**4 - 20*b**2 + 8)) + assert radsimp(1/(r2*a + r2*b + r2*c + r2*d)) == \ + sqrt(2)/(2*a + 2*b + 2*c + 2*d) + assert radsimp(1/(1 + r2*a + r2*b + r2*c + r2*d)) == ( + (sqrt(2)*a + sqrt(2)*b + sqrt(2)*c + sqrt(2)*d - 1)/(2*a**2 + 4*a*b + + 4*a*c + 4*a*d + 2*b**2 + 4*b*c + 4*b*d + 2*c**2 + 4*c*d + 2*d**2 - 1)) + assert radsimp((y**2 - x)/(y - sqrt(x))) == \ + sqrt(x) + y + assert radsimp(-(y**2 - x)/(y - sqrt(x))) == \ + -(sqrt(x) + y) + assert radsimp(1/(1 - I + a*I)) == \ + (-I*a + 1 + I)/(a**2 - 2*a + 2) + assert radsimp(1/((-x + y)*(x - sqrt(y)))) == \ + (-x - sqrt(y))/((x - y)*(x**2 - y)) + e = (3 + 3*sqrt(2))*x*(3*x - 3*sqrt(y)) + assert radsimp(e) == x*(3 + 3*sqrt(2))*(3*x - 3*sqrt(y)) + assert radsimp(1/e) == ( + (-9*x + 9*sqrt(2)*x - 9*sqrt(y) + 9*sqrt(2)*sqrt(y))/(9*x*(9*x**2 - + 9*y))) + assert radsimp(1 + 1/(1 + sqrt(3))) == \ + Mul(S.Half, -1 + sqrt(3), evaluate=False) + 1 + A = symbols("A", commutative=False) + assert radsimp(x**2 + sqrt(2)*x**2 - sqrt(2)*x*A) == \ + x**2 + sqrt(2)*x**2 - sqrt(2)*x*A + assert radsimp(1/sqrt(5 + 2 * sqrt(6))) == -sqrt(2) + sqrt(3) + assert radsimp(1/sqrt(5 + 2 * sqrt(6))**3) == -(-sqrt(3) + sqrt(2))**3 + + # issue 6532 + assert fraction(radsimp(1/sqrt(x))) == (sqrt(x), x) + assert fraction(radsimp(1/sqrt(2*x + 3))) == (sqrt(2*x + 3), 2*x + 3) + assert fraction(radsimp(1/sqrt(2*(x + 3)))) == (sqrt(2*x + 6), 2*x + 6) + + # issue 5994 + e = S('-(2 + 2*sqrt(2) + 4*2**(1/4))/' + '(1 + 2**(3/4) + 3*2**(1/4) + 3*sqrt(2))') + assert radsimp(e).expand() == -2*2**Rational(3, 4) - 2*2**Rational(1, 4) + 2 + 2*sqrt(2) + + # issue 5986 (modifications to radimp didn't initially recognize this so + # the test is included here) + assert radsimp(1/(-sqrt(5)/2 - S.Half + (-sqrt(5)/2 - S.Half)**2)) == 1 + + # from issue 5934 + eq = ( + (-240*sqrt(2)*sqrt(sqrt(5) + 5)*sqrt(8*sqrt(5) + 40) - + 360*sqrt(2)*sqrt(-8*sqrt(5) + 40)*sqrt(-sqrt(5) + 5) - + 120*sqrt(10)*sqrt(-8*sqrt(5) + 40)*sqrt(-sqrt(5) + 5) + + 120*sqrt(2)*sqrt(-sqrt(5) + 5)*sqrt(8*sqrt(5) + 40) + + 120*sqrt(2)*sqrt(-8*sqrt(5) + 40)*sqrt(sqrt(5) + 5) + + 120*sqrt(10)*sqrt(-sqrt(5) + 5)*sqrt(8*sqrt(5) + 40) + + 120*sqrt(10)*sqrt(-8*sqrt(5) + 40)*sqrt(sqrt(5) + 5))/(-36000 - + 7200*sqrt(5) + (12*sqrt(10)*sqrt(sqrt(5) + 5) + + 24*sqrt(10)*sqrt(-sqrt(5) + 5))**2)) + assert radsimp(eq) is S.NaN # it's 0/0 + + # work with normal form + e = 1/sqrt(sqrt(7)/7 + 2*sqrt(2) + 3*sqrt(3) + 5*sqrt(5)) + 3 + assert radsimp(e) == ( + -sqrt(sqrt(7) + 14*sqrt(2) + 21*sqrt(3) + + 35*sqrt(5))*(-11654899*sqrt(35) - 1577436*sqrt(210) - 1278438*sqrt(15) + - 1346996*sqrt(10) + 1635060*sqrt(6) + 5709765 + 7539830*sqrt(14) + + 8291415*sqrt(21))/1300423175 + 3) + + # obey power rules + base = sqrt(3) - sqrt(2) + assert radsimp(1/base**3) == (sqrt(3) + sqrt(2))**3 + assert radsimp(1/(-base)**3) == -(sqrt(2) + sqrt(3))**3 + assert radsimp(1/(-base)**x) == (-base)**(-x) + assert radsimp(1/base**x) == (sqrt(2) + sqrt(3))**x + assert radsimp(root(1/(-1 - sqrt(2)), -x)) == (-1)**(-1/x)*(1 + sqrt(2))**(1/x) + + # recurse + e = cos(1/(1 + sqrt(2))) + assert radsimp(e) == cos(-sqrt(2) + 1) + assert radsimp(e/2) == cos(-sqrt(2) + 1)/2 + assert radsimp(1/e) == 1/cos(-sqrt(2) + 1) + assert radsimp(2/e) == 2/cos(-sqrt(2) + 1) + assert fraction(radsimp(e/sqrt(x))) == (sqrt(x)*cos(-sqrt(2)+1), x) + + # test that symbolic denominators are not processed + r = 1 + sqrt(2) + assert radsimp(x/r, symbolic=False) == -x*(-sqrt(2) + 1) + assert radsimp(x/(y + r), symbolic=False) == x/(y + 1 + sqrt(2)) + assert radsimp(x/(y + r)/r, symbolic=False) == \ + -x*(-sqrt(2) + 1)/(y + 1 + sqrt(2)) + + # issue 7408 + eq = sqrt(x)/sqrt(y) + assert radsimp(eq) == umul(sqrt(x), sqrt(y), 1/y) + assert radsimp(eq, symbolic=False) == eq + + # issue 7498 + assert radsimp(sqrt(x)/sqrt(y)**3) == umul(sqrt(x), sqrt(y**3), 1/y**3) + + # for coverage + eq = sqrt(x)/y**2 + assert radsimp(eq) == eq + + # handle non-Expr args + from sympy.integrals.integrals import Integral + eq = Integral(x/(sqrt(2) - 1), (x, 0, 1/(sqrt(2) + 1))) + assert radsimp(eq) == Integral((sqrt(2) + 1)*x , (x, 0, sqrt(2) - 1)) + + from sympy.sets import FiniteSet + eq = FiniteSet(x/(sqrt(2) - 1)) + assert radsimp(eq) == FiniteSet((sqrt(2) + 1)*x) + +def test_radsimp_issue_3214(): + c, p = symbols('c p', positive=True) + s = sqrt(c**2 - p**2) + b = (c + I*p - s)/(c + I*p + s) + assert radsimp(b) == -I*(c + I*p - sqrt(c**2 - p**2))**2/(2*c*p) + + +def test_collect_1(): + """Collect with respect to Symbol""" + x, y, z, n = symbols('x,y,z,n') + assert collect(1, x) == 1 + assert collect( x + y*x, x ) == x * (1 + y) + assert collect( x + x**2, x ) == x + x**2 + assert collect( x**2 + y*x**2, x ) == (x**2)*(1 + y) + assert collect( x**2 + y*x, x ) == x*y + x**2 + assert collect( 2*x**2 + y*x**2 + 3*x*y, [x] ) == x**2*(2 + y) + 3*x*y + assert collect( 2*x**2 + y*x**2 + 3*x*y, [y] ) == 2*x**2 + y*(x**2 + 3*x) + + assert collect( ((1 + y + x)**4).expand(), x) == ((1 + y)**4).expand() + \ + x*(4*(1 + y)**3).expand() + x**2*(6*(1 + y)**2).expand() + \ + x**3*(4*(1 + y)).expand() + x**4 + # symbols can be given as any iterable + expr = x + y + assert collect(expr, expr.free_symbols) == expr + assert collect(x*exp(x) + sin(x)*y + sin(x)*2 + 3*x, x, exact=None + ) == x*exp(x) + 3*x + (y + 2)*sin(x) + assert collect(x*exp(x) + sin(x)*y + sin(x)*2 + 3*x + y*x + + y*x*exp(x), x, exact=None + ) == x*exp(x)*(y + 1) + (3 + y)*x + (y + 2)*sin(x) + + +def test_collect_2(): + """Collect with respect to a sum""" + a, b, x = symbols('a,b,x') + assert collect(a*(cos(x) + sin(x)) + b*(cos(x) + sin(x)), + sin(x) + cos(x)) == (a + b)*(cos(x) + sin(x)) + + +def test_collect_3(): + """Collect with respect to a product""" + a, b, c = symbols('a,b,c') + f = Function('f') + x, y, z, n = symbols('x,y,z,n') + + assert collect(-x/8 + x*y, -x) == x*(y - Rational(1, 8)) + + assert collect( 1 + x*(y**2), x*y ) == 1 + x*(y**2) + assert collect( x*y + a*x*y, x*y) == x*y*(1 + a) + assert collect( 1 + x*y + a*x*y, x*y) == 1 + x*y*(1 + a) + assert collect(a*x*f(x) + b*(x*f(x)), x*f(x)) == x*(a + b)*f(x) + + assert collect(a*x*log(x) + b*(x*log(x)), x*log(x)) == x*(a + b)*log(x) + assert collect(a*x**2*log(x)**2 + b*(x*log(x))**2, x*log(x)) == \ + x**2*log(x)**2*(a + b) + + # with respect to a product of three symbols + assert collect(y*x*z + a*x*y*z, x*y*z) == (1 + a)*x*y*z + + +def test_collect_4(): + """Collect with respect to a power""" + a, b, c, x = symbols('a,b,c,x') + + assert collect(a*x**c + b*x**c, x**c) == x**c*(a + b) + # issue 6096: 2 stays with c (unless c is integer or x is positive0 + assert collect(a*x**(2*c) + b*x**(2*c), x**c) == x**(2*c)*(a + b) + + +def test_collect_5(): + """Collect with respect to a tuple""" + a, x, y, z, n = symbols('a,x,y,z,n') + assert collect(x**2*y**4 + z*(x*y**2)**2 + z + a*z, [x*y**2, z]) in [ + z*(1 + a + x**2*y**4) + x**2*y**4, + z*(1 + a) + x**2*y**4*(1 + z) ] + assert collect((1 + (x + y) + (x + y)**2).expand(), + [x, y]) == 1 + y + x*(1 + 2*y) + x**2 + y**2 + + +def test_collect_pr19431(): + """Unevaluated collect with respect to a product""" + a = symbols('a') + assert collect(a**2*(a**2 + 1), a**2, evaluate=False)[a**2] == (a**2 + 1) + + +def test_collect_D(): + D = Derivative + f = Function('f') + x, a, b = symbols('x,a,b') + fx = D(f(x), x) + fxx = D(f(x), x, x) + + assert collect(a*fx + b*fx, fx) == (a + b)*fx + assert collect(a*D(fx, x) + b*D(fx, x), fx) == (a + b)*D(fx, x) + assert collect(a*fxx + b*fxx, fx) == (a + b)*D(fx, x) + # issue 4784 + assert collect(5*f(x) + 3*fx, fx) == 5*f(x) + 3*fx + assert collect(f(x) + f(x)*diff(f(x), x) + x*diff(f(x), x)*f(x), f(x).diff(x)) == \ + (x*f(x) + f(x))*D(f(x), x) + f(x) + assert collect(f(x) + f(x)*diff(f(x), x) + x*diff(f(x), x)*f(x), f(x).diff(x), exact=True) == \ + (x*f(x) + f(x))*D(f(x), x) + f(x) + assert collect(1/f(x) + 1/f(x)*diff(f(x), x) + x*diff(f(x), x)/f(x), f(x).diff(x), exact=True) == \ + (1/f(x) + x/f(x))*D(f(x), x) + 1/f(x) + e = (1 + x*fx + fx)/f(x) + assert collect(e.expand(), fx) == fx*(x/f(x) + 1/f(x)) + 1/f(x) + + +def test_collect_func(): + f = ((x + a + 1)**3).expand() + + assert collect(f, x) == a**3 + 3*a**2 + 3*a + x**3 + x**2*(3*a + 3) + \ + x*(3*a**2 + 6*a + 3) + 1 + assert collect(f, x, factor) == x**3 + 3*x**2*(a + 1) + 3*x*(a + 1)**2 + \ + (a + 1)**3 + + assert collect(f, x, evaluate=False) == { + S.One: a**3 + 3*a**2 + 3*a + 1, + x: 3*a**2 + 6*a + 3, x**2: 3*a + 3, + x**3: 1 + } + + assert collect(f, x, factor, evaluate=False) == { + S.One: (a + 1)**3, x: 3*(a + 1)**2, + x**2: umul(S(3), a + 1), x**3: 1} + + +def test_collect_order(): + a, b, x, t = symbols('a,b,x,t') + + assert collect(t + t*x + t*x**2 + O(x**3), t) == t*(1 + x + x**2 + O(x**3)) + assert collect(t + t*x + x**2 + O(x**3), t) == \ + t*(1 + x + O(x**3)) + x**2 + O(x**3) + + f = a*x + b*x + c*x**2 + d*x**2 + O(x**3) + g = x*(a + b) + x**2*(c + d) + O(x**3) + + assert collect(f, x) == g + assert collect(f, x, distribute_order_term=False) == g + + f = sin(a + b).series(b, 0, 10) + + assert collect(f, [sin(a), cos(a)]) == \ + sin(a)*cos(b).series(b, 0, 10) + cos(a)*sin(b).series(b, 0, 10) + assert collect(f, [sin(a), cos(a)], distribute_order_term=False) == \ + sin(a)*cos(b).series(b, 0, 10).removeO() + \ + cos(a)*sin(b).series(b, 0, 10).removeO() + O(b**10) + + +def test_rcollect(): + assert rcollect((x**2*y + x*y + x + y)/(x + y), y) == \ + (x + y*(1 + x + x**2))/(x + y) + assert rcollect(sqrt(-((x + 1)*(y + 1))), z) == sqrt(-((x + 1)*(y + 1))) + + +def test_collect_D_0(): + D = Derivative + f = Function('f') + x, a, b = symbols('x,a,b') + fxx = D(f(x), x, x) + + assert collect(a*fxx + b*fxx, fxx) == (a + b)*fxx + + +def test_collect_Wild(): + """Collect with respect to functions with Wild argument""" + a, b, x, y = symbols('a b x y') + f = Function('f') + w1 = Wild('.1') + w2 = Wild('.2') + assert collect(f(x) + a*f(x), f(w1)) == (1 + a)*f(x) + assert collect(f(x, y) + a*f(x, y), f(w1)) == f(x, y) + a*f(x, y) + assert collect(f(x, y) + a*f(x, y), f(w1, w2)) == (1 + a)*f(x, y) + assert collect(f(x, y) + a*f(x, y), f(w1, w1)) == f(x, y) + a*f(x, y) + assert collect(f(x, x) + a*f(x, x), f(w1, w1)) == (1 + a)*f(x, x) + assert collect(a*(x + 1)**y + (x + 1)**y, w1**y) == (1 + a)*(x + 1)**y + assert collect(a*(x + 1)**y + (x + 1)**y, w1**b) == \ + a*(x + 1)**y + (x + 1)**y + assert collect(a*(x + 1)**y + (x + 1)**y, (x + 1)**w2) == \ + (1 + a)*(x + 1)**y + assert collect(a*(x + 1)**y + (x + 1)**y, w1**w2) == (1 + a)*(x + 1)**y + + +def test_collect_const(): + # coverage not provided by above tests + assert collect_const(2*sqrt(3) + 4*a*sqrt(5)) == \ + 2*(2*sqrt(5)*a + sqrt(3)) # let the primitive reabsorb + assert collect_const(2*sqrt(3) + 4*a*sqrt(5), sqrt(3)) == \ + 2*sqrt(3) + 4*a*sqrt(5) + assert collect_const(sqrt(2)*(1 + sqrt(2)) + sqrt(3) + x*sqrt(2)) == \ + sqrt(2)*(x + 1 + sqrt(2)) + sqrt(3) + + # issue 5290 + assert collect_const(2*x + 2*y + 1, 2) == \ + collect_const(2*x + 2*y + 1) == \ + Add(S.One, Mul(2, x + y, evaluate=False), evaluate=False) + assert collect_const(-y - z) == Mul(-1, y + z, evaluate=False) + assert collect_const(2*x - 2*y - 2*z, 2) == \ + Mul(2, x - y - z, evaluate=False) + assert collect_const(2*x - 2*y - 2*z, -2) == \ + _unevaluated_Add(2*x, Mul(-2, y + z, evaluate=False)) + + # this is why the content_primitive is used + eq = (sqrt(15 + 5*sqrt(2))*x + sqrt(3 + sqrt(2))*y)*2 + assert collect_sqrt(eq + 2) == \ + 2*sqrt(sqrt(2) + 3)*(sqrt(5)*x + y) + 2 + + # issue 16296 + assert collect_const(a + b + x/2 + y/2) == a + b + Mul(S.Half, x + y, evaluate=False) + + +def test_issue_13143(): + f = Function('f') + fx = f(x).diff(x) + e = f(x) + fx + f(x)*fx + # collect function before derivative + assert collect(e, Wild('w')) == f(x)*(fx + 1) + fx + e = f(x) + f(x)*fx + x*fx*f(x) + assert collect(e, fx) == (x*f(x) + f(x))*fx + f(x) + assert collect(e, f(x)) == (x*fx + fx + 1)*f(x) + e = f(x) + fx + f(x)*fx + assert collect(e, [f(x), fx]) == f(x)*(1 + fx) + fx + assert collect(e, [fx, f(x)]) == fx*(1 + f(x)) + f(x) + + +def test_issue_6097(): + assert collect(a*y**(2.0*x) + b*y**(2.0*x), y**x) == (a + b)*(y**x)**2.0 + assert collect(a*2**(2.0*x) + b*2**(2.0*x), 2**x) == (a + b)*(2**x)**2.0 + + +def test_fraction_expand(): + eq = (x + y)*y/x + assert eq.expand(frac=True) == fraction_expand(eq) == (x*y + y**2)/x + assert eq.expand() == y + y**2/x + + +def test_fraction(): + x, y, z = map(Symbol, 'xyz') + A = Symbol('A', commutative=False) + + assert fraction(S.Half) == (1, 2) + + assert fraction(x) == (x, 1) + assert fraction(1/x) == (1, x) + assert fraction(x/y) == (x, y) + assert fraction(x/2) == (x, 2) + + assert fraction(x*y/z) == (x*y, z) + assert fraction(x/(y*z)) == (x, y*z) + + assert fraction(1/y**2) == (1, y**2) + assert fraction(x/y**2) == (x, y**2) + + assert fraction((x**2 + 1)/y) == (x**2 + 1, y) + assert fraction(x*(y + 1)/y**7) == (x*(y + 1), y**7) + + assert fraction(exp(-x), exact=True) == (exp(-x), 1) + assert fraction((1/(x + y))/2, exact=True) == (1, Mul(2,(x + y), evaluate=False)) + + assert fraction(x*A/y) == (x*A, y) + assert fraction(x*A**-1/y) == (x*A**-1, y) + + n = symbols('n', negative=True) + assert fraction(exp(n)) == (1, exp(-n)) + assert fraction(exp(-n)) == (exp(-n), 1) + + p = symbols('p', positive=True) + assert fraction(exp(-p)*log(p), exact=True) == (exp(-p)*log(p), 1) + + m = Mul(1, 1, S.Half, evaluate=False) + assert fraction(m) == (1, 2) + assert fraction(m, exact=True) == (Mul(1, 1, evaluate=False), 2) + + m = Mul(1, 1, S.Half, S.Half, Pow(1, -1, evaluate=False), evaluate=False) + assert fraction(m) == (1, 4) + assert fraction(m, exact=True) == \ + (Mul(1, 1, evaluate=False), Mul(2, 2, 1, evaluate=False)) + + +def test_issue_5615(): + aA, Re, a, b, D = symbols('aA Re a b D') + e = ((D**3*a + b*aA**3)/Re).expand() + assert collect(e, [aA**3/Re, a]) == e + + +def test_issue_5933(): + from sympy.geometry.polygon import (Polygon, RegularPolygon) + from sympy.simplify.radsimp import denom + x = Polygon(*RegularPolygon((0, 0), 1, 5).vertices).centroid.x + assert abs(denom(x).n()) > 1e-12 + assert abs(denom(radsimp(x))) > 1e-12 # in case simplify didn't handle it + + +def test_issue_14608(): + a, b = symbols('a b', commutative=False) + x, y = symbols('x y') + raises(AttributeError, lambda: collect(a*b + b*a, a)) + assert collect(x*y + y*(x+1), a) == x*y + y*(x+1) + assert collect(x*y + y*(x+1) + a*b + b*a, y) == y*(2*x + 1) + a*b + b*a + + +def test_collect_abs(): + s = abs(x) + abs(y) + assert collect_abs(s) == s + assert unchanged(Mul, abs(x), abs(y)) + ans = Abs(x*y) + assert isinstance(ans, Abs) + assert collect_abs(abs(x)*abs(y)) == ans + assert collect_abs(1 + exp(abs(x)*abs(y))) == 1 + exp(ans) + + # See https://github.com/sympy/sympy/issues/12910 + p = Symbol('p', positive=True) + assert collect_abs(p/abs(1-p)).is_commutative is True + + +def test_issue_19149(): + eq = exp(3*x/4) + assert collect(eq, exp(x)) == eq + +def test_issue_19719(): + a, b = symbols('a, b') + expr = a**2 * (b + 1) + (7 + 1/b)/a + collected = collect(expr, (a**2, 1/a), evaluate=False) + # Would return {_Dummy_20**(-2): b + 1, 1/a: 7 + 1/b} without xreplace + assert collected == {a**2: b + 1, 1/a: 7 + 1/b} + + +def test_issue_21355(): + assert radsimp(1/(x + sqrt(x**2))) == 1/(x + sqrt(x**2)) + assert radsimp(1/(x - sqrt(x**2))) == 1/(x - sqrt(x**2)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_ratsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_ratsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..14e84fd2b227518baff1bda4e5b27ecc40a8bcdd --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_ratsimp.py @@ -0,0 +1,78 @@ +from sympy.core.numbers import (Rational, pi) +from sympy.functions.elementary.exponential import log +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.special.error_functions import erf +from sympy.polys.domains import GF +from sympy.simplify.ratsimp import (ratsimp, ratsimpmodprime) + +from sympy.abc import x, y, z, t, a, b, c, d, e + + +def test_ratsimp(): + f, g = 1/x + 1/y, (x + y)/(x*y) + + assert f != g and ratsimp(f) == g + + f, g = 1/(1 + 1/x), 1 - 1/(x + 1) + + assert f != g and ratsimp(f) == g + + f, g = x/(x + y) + y/(x + y), 1 + + assert f != g and ratsimp(f) == g + + f, g = -x - y - y**2/(x + y) + x**2/(x + y), -2*y + + assert f != g and ratsimp(f) == g + + f = (a*c*x*y + a*c*z - b*d*x*y - b*d*z - b*t*x*y - b*t*x - b*t*z + + e*x)/(x*y + z) + G = [a*c - b*d - b*t + (-b*t*x + e*x)/(x*y + z), + a*c - b*d - b*t - ( b*t*x - e*x)/(x*y + z)] + + assert f != g and ratsimp(f) in G + + A = sqrt(pi) + + B = log(erf(x) - 1) + C = log(erf(x) + 1) + + D = 8 - 8*erf(x) + + f = A*B/D - A*C/D + A*C*erf(x)/D - A*B*erf(x)/D + 2*A/D + + assert ratsimp(f) == A*B/8 - A*C/8 - A/(4*erf(x) - 4) + + +def test_ratsimpmodprime(): + a = y**5 + x + y + b = x - y + F = [x*y**5 - x - y] + assert ratsimpmodprime(a/b, F, x, y, order='lex') == \ + (-x**2 - x*y - x - y) / (-x**2 + x*y) + + a = x + y**2 - 2 + b = x + y**2 - y - 1 + F = [x*y - 1] + assert ratsimpmodprime(a/b, F, x, y, order='lex') == \ + (1 + y - x)/(y - x) + + a = 5*x**3 + 21*x**2 + 4*x*y + 23*x + 12*y + 15 + b = 7*x**3 - y*x**2 + 31*x**2 + 2*x*y + 15*y + 37*x + 21 + F = [x**2 + y**2 - 1] + assert ratsimpmodprime(a/b, F, x, y, order='lex') == \ + (1 + 5*y - 5*x)/(8*y - 6*x) + + a = x*y - x - 2*y + 4 + b = x + y**2 - 2*y + F = [x - 2, y - 3] + assert ratsimpmodprime(a/b, F, x, y, order='lex') == \ + Rational(2, 5) + + # Test a bug where denominators would be dropped + assert ratsimpmodprime(x, [y - 2*x], order='lex') == \ + y/2 + + a = (x**5 + 2*x**4 + 2*x**3 + 2*x**2 + x + 2/x + x**(-2)) + assert ratsimpmodprime(a, [x + 1], domain=GF(2)) == 1 + assert ratsimpmodprime(a, [x + 1], domain=GF(3)) == -1 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_rewrite.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_rewrite.py new file mode 100644 index 0000000000000000000000000000000000000000..56d2fb7a85bd959bd4accc2f36127429efbdbe70 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_rewrite.py @@ -0,0 +1,31 @@ +from sympy.core.numbers import I +from sympy.core.symbol import symbols +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.trigonometric import (cos, cot, sin) +from sympy.testing.pytest import _both_exp_pow + +x, y, z, n = symbols('x,y,z,n') + + +@_both_exp_pow +def test_has(): + assert cot(x).has(x) + assert cot(x).has(cot) + assert not cot(x).has(sin) + assert sin(x).has(x) + assert sin(x).has(sin) + assert not sin(x).has(cot) + assert exp(x).has(exp) + + +@_both_exp_pow +def test_sin_exp_rewrite(): + assert sin(x).rewrite(sin, exp) == -I/2*(exp(I*x) - exp(-I*x)) + assert sin(x).rewrite(sin, exp).rewrite(exp, sin) == sin(x) + assert cos(x).rewrite(cos, exp).rewrite(exp, cos) == cos(x) + assert (sin(5*y) - sin( + 2*x)).rewrite(sin, exp).rewrite(exp, sin) == sin(5*y) - sin(2*x) + assert sin(x + y).rewrite(sin, exp).rewrite(exp, sin) == sin(x + y) + assert cos(x + y).rewrite(cos, exp).rewrite(exp, cos) == cos(x + y) + # This next test currently passes... not clear whether it should or not? + assert cos(x).rewrite(cos, exp).rewrite(exp, sin) == cos(x) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_simplify.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_simplify.py new file mode 100644 index 0000000000000000000000000000000000000000..a5bf469f68adf5c5dfbdf7559414681e2fb28ba7 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_simplify.py @@ -0,0 +1,1093 @@ +from sympy.concrete.summations import Sum +from sympy.core.add import Add +from sympy.core.basic import Basic +from sympy.core.expr import unchanged +from sympy.core.function import (count_ops, diff, expand, expand_multinomial, Function, Derivative) +from sympy.core.mul import Mul, _keep_coeff +from sympy.core import GoldenRatio +from sympy.core.numbers import (E, Float, I, oo, pi, Rational, zoo) +from sympy.core.relational import (Eq, Lt, Gt, Ge, Le) +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import (binomial, factorial) +from sympy.functions.elementary.complexes import (Abs, sign) +from sympy.functions.elementary.exponential import (exp, exp_polar, log) +from sympy.functions.elementary.hyperbolic import (cosh, csch, sinh) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (acos, asin, atan, cos, sin, sinc, tan) +from sympy.functions.special.error_functions import erf +from sympy.functions.special.gamma_functions import gamma +from sympy.functions.special.hyper import hyper +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.geometry.polygon import rad +from sympy.integrals.integrals import (Integral, integrate) +from sympy.logic.boolalg import (And, Or) +from sympy.matrices.dense import (Matrix, eye) +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.polys.polytools import (factor, Poly) +from sympy.simplify.simplify import (besselsimp, hypersimp, inversecombine, logcombine, nsimplify, nthroot, posify, separatevars, signsimp, simplify) +from sympy.solvers.solvers import solve + +from sympy.testing.pytest import XFAIL, slow, _both_exp_pow +from sympy.abc import x, y, z, t, a, b, c, d, e, f, g, h, i, n + + +def test_issue_7263(): + assert abs((simplify(30.8**2 - 82.5**2 * sin(rad(11.6))**2)).evalf() - \ + 673.447451402970) < 1e-12 + + +def test_factorial_simplify(): + # There are more tests in test_factorials.py. + x = Symbol('x') + assert simplify(factorial(x)/x) == gamma(x) + assert simplify(factorial(factorial(x))) == factorial(factorial(x)) + + +def test_simplify_expr(): + x, y, z, k, n, m, w, s, A = symbols('x,y,z,k,n,m,w,s,A') + f = Function('f') + + assert all(simplify(tmp) == tmp for tmp in [I, E, oo, x, -x, -oo, -E, -I]) + + e = 1/x + 1/y + assert e != (x + y)/(x*y) + assert simplify(e) == (x + y)/(x*y) + + e = A**2*s**4/(4*pi*k*m**3) + assert simplify(e) == e + + e = (4 + 4*x - 2*(2 + 2*x))/(2 + 2*x) + assert simplify(e) == 0 + + e = (-4*x*y**2 - 2*y**3 - 2*x**2*y)/(x + y)**2 + assert simplify(e) == -2*y + + e = -x - y - (x + y)**(-1)*y**2 + (x + y)**(-1)*x**2 + assert simplify(e) == -2*y + + e = (x + x*y)/x + assert simplify(e) == 1 + y + + e = (f(x) + y*f(x))/f(x) + assert simplify(e) == 1 + y + + e = (2 * (1/n - cos(n * pi)/n))/pi + assert simplify(e) == (-cos(pi*n) + 1)/(pi*n)*2 + + e = integrate(1/(x**3 + 1), x).diff(x) + assert simplify(e) == 1/(x**3 + 1) + + e = integrate(x/(x**2 + 3*x + 1), x).diff(x) + assert simplify(e) == x/(x**2 + 3*x + 1) + + f = Symbol('f') + A = Matrix([[2*k - m*w**2, -k], [-k, k - m*w**2]]).inv() + assert simplify((A*Matrix([0, f]))[1] - + (-f*(2*k - m*w**2)/(k**2 - (k - m*w**2)*(2*k - m*w**2)))) == 0 + + f = -x + y/(z + t) + z*x/(z + t) + z*a/(z + t) + t*x/(z + t) + assert simplify(f) == (y + a*z)/(z + t) + + # issue 10347 + expr = -x*(y**2 - 1)*(2*y**2*(x**2 - 1)/(a*(x**2 - y**2)**2) + (x**2 - 1) + /(a*(x**2 - y**2)))/(a*(x**2 - y**2)) + x*(-2*x**2*sqrt(-x**2*y**2 + x**2 + + y**2 - 1)*sin(z)/(a*(x**2 - y**2)**2) - x**2*sqrt(-x**2*y**2 + x**2 + + y**2 - 1)*sin(z)/(a*(x**2 - 1)*(x**2 - y**2)) + (x**2*sqrt((-x**2 + 1)* + (y**2 - 1))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*sin(z)/(x**2 - 1) + sqrt( + (-x**2 + 1)*(y**2 - 1))*(x*(-x*y**2 + x)/sqrt(-x**2*y**2 + x**2 + y**2 - + 1) + sqrt(-x**2*y**2 + x**2 + y**2 - 1))*sin(z))/(a*sqrt((-x**2 + 1)*( + y**2 - 1))*(x**2 - y**2)))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*sin(z)/(a* + (x**2 - y**2)) + x*(-2*x**2*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos(z)/(a* + (x**2 - y**2)**2) - x**2*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos(z)/(a* + (x**2 - 1)*(x**2 - y**2)) + (x**2*sqrt((-x**2 + 1)*(y**2 - 1))*sqrt(-x**2 + *y**2 + x**2 + y**2 - 1)*cos(z)/(x**2 - 1) + x*sqrt((-x**2 + 1)*(y**2 - + 1))*(-x*y**2 + x)*cos(z)/sqrt(-x**2*y**2 + x**2 + y**2 - 1) + sqrt((-x**2 + + 1)*(y**2 - 1))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos(z))/(a*sqrt((-x**2 + + 1)*(y**2 - 1))*(x**2 - y**2)))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos( + z)/(a*(x**2 - y**2)) - y*sqrt((-x**2 + 1)*(y**2 - 1))*(-x*y*sqrt(-x**2* + y**2 + x**2 + y**2 - 1)*sin(z)/(a*(x**2 - y**2)*(y**2 - 1)) + 2*x*y*sqrt( + -x**2*y**2 + x**2 + y**2 - 1)*sin(z)/(a*(x**2 - y**2)**2) + (x*y*sqrt(( + -x**2 + 1)*(y**2 - 1))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*sin(z)/(y**2 - + 1) + x*sqrt((-x**2 + 1)*(y**2 - 1))*(-x**2*y + y)*sin(z)/sqrt(-x**2*y**2 + + x**2 + y**2 - 1))/(a*sqrt((-x**2 + 1)*(y**2 - 1))*(x**2 - y**2)))*sin( + z)/(a*(x**2 - y**2)) + y*(x**2 - 1)*(-2*x*y*(x**2 - 1)/(a*(x**2 - y**2) + **2) + 2*x*y/(a*(x**2 - y**2)))/(a*(x**2 - y**2)) + y*(x**2 - 1)*(y**2 - + 1)*(-x*y*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos(z)/(a*(x**2 - y**2)*(y**2 + - 1)) + 2*x*y*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos(z)/(a*(x**2 - y**2) + **2) + (x*y*sqrt((-x**2 + 1)*(y**2 - 1))*sqrt(-x**2*y**2 + x**2 + y**2 - + 1)*cos(z)/(y**2 - 1) + x*sqrt((-x**2 + 1)*(y**2 - 1))*(-x**2*y + y)*cos( + z)/sqrt(-x**2*y**2 + x**2 + y**2 - 1))/(a*sqrt((-x**2 + 1)*(y**2 - 1) + )*(x**2 - y**2)))*cos(z)/(a*sqrt((-x**2 + 1)*(y**2 - 1))*(x**2 - y**2) + ) - x*sqrt((-x**2 + 1)*(y**2 - 1))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*sin( + z)**2/(a**2*(x**2 - 1)*(x**2 - y**2)*(y**2 - 1)) - x*sqrt((-x**2 + 1)*( + y**2 - 1))*sqrt(-x**2*y**2 + x**2 + y**2 - 1)*cos(z)**2/(a**2*(x**2 - 1)*( + x**2 - y**2)*(y**2 - 1)) + assert simplify(expr) == 2*x/(a**2*(x**2 - y**2)) + + #issue 17631 + assert simplify('((-1/2)*Boole(True)*Boole(False)-1)*Boole(True)') == \ + Mul(sympify('(2 + Boole(True)*Boole(False))'), sympify('-Boole(True)/2')) + + A, B = symbols('A,B', commutative=False) + + assert simplify(A*B - B*A) == A*B - B*A + assert simplify(A/(1 + y/x)) == x*A/(x + y) + assert simplify(A*(1/x + 1/y)) == A/x + A/y #(x + y)*A/(x*y) + + assert simplify(log(2) + log(3)) == log(6) + assert simplify(log(2*x) - log(2)) == log(x) + + assert simplify(hyper([], [], x)) == exp(x) + + +def test_issue_3557(): + f_1 = x*a + y*b + z*c - 1 + f_2 = x*d + y*e + z*f - 1 + f_3 = x*g + y*h + z*i - 1 + + solutions = solve([f_1, f_2, f_3], x, y, z, simplify=False) + + assert simplify(solutions[y]) == \ + (a*i + c*d + f*g - a*f - c*g - d*i)/ \ + (a*e*i + b*f*g + c*d*h - a*f*h - b*d*i - c*e*g) + + +def test_simplify_other(): + assert simplify(sin(x)**2 + cos(x)**2) == 1 + assert simplify(gamma(x + 1)/gamma(x)) == x + assert simplify(sin(x)**2 + cos(x)**2 + factorial(x)/gamma(x)) == 1 + x + assert simplify( + Eq(sin(x)**2 + cos(x)**2, factorial(x)/gamma(x))) == Eq(x, 1) + nc = symbols('nc', commutative=False) + assert simplify(x + x*nc) == x*(1 + nc) + # issue 6123 + # f = exp(-I*(k*sqrt(t) + x/(2*sqrt(t)))**2) + # ans = integrate(f, (k, -oo, oo), conds='none') + ans = I*(-pi*x*exp(I*pi*Rational(-3, 4) + I*x**2/(4*t))*erf(x*exp(I*pi*Rational(-3, 4))/ + (2*sqrt(t)))/(2*sqrt(t)) + pi*x*exp(I*pi*Rational(-3, 4) + I*x**2/(4*t))/ + (2*sqrt(t)))*exp(-I*x**2/(4*t))/(sqrt(pi)*x) - I*sqrt(pi) * \ + (-erf(x*exp(I*pi/4)/(2*sqrt(t))) + 1)*exp(I*pi/4)/(2*sqrt(t)) + assert simplify(ans) == -(-1)**Rational(3, 4)*sqrt(pi)/sqrt(t) + # issue 6370 + assert simplify(2**(2 + x)/4) == 2**x + + +@_both_exp_pow +def test_simplify_complex(): + cosAsExp = cos(x)._eval_rewrite_as_exp(x) + tanAsExp = tan(x)._eval_rewrite_as_exp(x) + assert simplify(cosAsExp*tanAsExp) == sin(x) # issue 4341 + + # issue 10124 + assert simplify(exp(Matrix([[0, -1], [1, 0]]))) == Matrix([[cos(1), + -sin(1)], [sin(1), cos(1)]]) + + +def test_simplify_ratio(): + # roots of x**3-3*x+5 + roots = ['(1/2 - sqrt(3)*I/2)*(sqrt(21)/2 + 5/2)**(1/3) + 1/((1/2 - ' + 'sqrt(3)*I/2)*(sqrt(21)/2 + 5/2)**(1/3))', + '1/((1/2 + sqrt(3)*I/2)*(sqrt(21)/2 + 5/2)**(1/3)) + ' + '(1/2 + sqrt(3)*I/2)*(sqrt(21)/2 + 5/2)**(1/3)', + '-(sqrt(21)/2 + 5/2)**(1/3) - 1/(sqrt(21)/2 + 5/2)**(1/3)'] + + for r in roots: + r = S(r) + assert count_ops(simplify(r, ratio=1)) <= count_ops(r) + # If ratio=oo, simplify() is always applied: + assert simplify(r, ratio=oo) is not r + + +def test_simplify_measure(): + measure1 = lambda expr: len(str(expr)) + measure2 = lambda expr: -count_ops(expr) + # Return the most complicated result + expr = (x + 1)/(x + sin(x)**2 + cos(x)**2) + assert measure1(simplify(expr, measure=measure1)) <= measure1(expr) + assert measure2(simplify(expr, measure=measure2)) <= measure2(expr) + + expr2 = Eq(sin(x)**2 + cos(x)**2, 1) + assert measure1(simplify(expr2, measure=measure1)) <= measure1(expr2) + assert measure2(simplify(expr2, measure=measure2)) <= measure2(expr2) + + +def test_simplify_rational(): + expr = 2**x*2.**y + assert simplify(expr, rational = True) == 2**(x+y) + assert simplify(expr, rational = None) == 2.0**(x+y) + assert simplify(expr, rational = False) == expr + assert simplify('0.9 - 0.8 - 0.1', rational = True) == 0 + + +def test_simplify_issue_1308(): + assert simplify(exp(Rational(-1, 2)) + exp(Rational(-3, 2))) == \ + (1 + E)*exp(Rational(-3, 2)) + + +def test_issue_5652(): + assert simplify(E + exp(-E)) == exp(-E) + E + n = symbols('n', commutative=False) + assert simplify(n + n**(-n)) == n + n**(-n) + +def test_issue_27380(): + assert simplify(1.0**(x+1)/1.0**x) == 1.0 + +def test_simplify_fail1(): + x = Symbol('x') + y = Symbol('y') + e = (x + y)**2/(-4*x*y**2 - 2*y**3 - 2*x**2*y) + assert simplify(e) == 1 / (-2*y) + + +def test_nthroot(): + assert nthroot(90 + 34*sqrt(7), 3) == sqrt(7) + 3 + q = 1 + sqrt(2) - 2*sqrt(3) + sqrt(6) + sqrt(7) + assert nthroot(expand_multinomial(q**3), 3) == q + assert nthroot(41 + 29*sqrt(2), 5) == 1 + sqrt(2) + assert nthroot(-41 - 29*sqrt(2), 5) == -1 - sqrt(2) + expr = 1320*sqrt(10) + 4216 + 2576*sqrt(6) + 1640*sqrt(15) + assert nthroot(expr, 5) == 1 + sqrt(6) + sqrt(15) + q = 1 + sqrt(2) + sqrt(3) + sqrt(5) + assert expand_multinomial(nthroot(expand_multinomial(q**5), 5)) == q + q = 1 + sqrt(2) + 7*sqrt(6) + 2*sqrt(10) + assert nthroot(expand_multinomial(q**5), 5, 8) == q + q = 1 + sqrt(2) - 2*sqrt(3) + 1171*sqrt(6) + assert nthroot(expand_multinomial(q**3), 3) == q + assert nthroot(expand_multinomial(q**6), 6) == q + + +def test_nthroot1(): + q = 1 + sqrt(2) + sqrt(3) + S.One/10**20 + p = expand_multinomial(q**5) + assert nthroot(p, 5) == q + q = 1 + sqrt(2) + sqrt(3) + S.One/10**30 + p = expand_multinomial(q**5) + assert nthroot(p, 5) == q + + +@_both_exp_pow +def test_separatevars(): + x, y, z, n = symbols('x,y,z,n') + assert separatevars(2*n*x*z + 2*x*y*z) == 2*x*z*(n + y) + assert separatevars(x*z + x*y*z) == x*z*(1 + y) + assert separatevars(pi*x*z + pi*x*y*z) == pi*x*z*(1 + y) + assert separatevars(x*y**2*sin(x) + x*sin(x)*sin(y)) == \ + x*(sin(y) + y**2)*sin(x) + assert separatevars(x*exp(x + y) + x*exp(x)) == x*(1 + exp(y))*exp(x) + assert separatevars((x*(y + 1))**z).is_Pow # != x**z*(1 + y)**z + assert separatevars(1 + x + y + x*y) == (x + 1)*(y + 1) + assert separatevars(y/pi*exp(-(z - x)/cos(n))) == \ + y*exp(x/cos(n))*exp(-z/cos(n))/pi + assert separatevars((x + y)*(x - y) + y**2 + 2*x + 1) == (x + 1)**2 + # issue 4858 + p = Symbol('p', positive=True) + assert separatevars(sqrt(p**2 + x*p**2)) == p*sqrt(1 + x) + assert separatevars(sqrt(y*(p**2 + x*p**2))) == p*sqrt(y*(1 + x)) + assert separatevars(sqrt(y*(p**2 + x*p**2)), force=True) == \ + p*sqrt(y)*sqrt(1 + x) + # issue 4865 + assert separatevars(sqrt(x*y)).is_Pow + assert separatevars(sqrt(x*y), force=True) == sqrt(x)*sqrt(y) + # issue 4957 + # any type sequence for symbols is fine + assert separatevars(((2*x + 2)*y), dict=True, symbols=()) == \ + {'coeff': 1, x: 2*x + 2, y: y} + # separable + assert separatevars(((2*x + 2)*y), dict=True, symbols=[x]) == \ + {'coeff': y, x: 2*x + 2} + assert separatevars(((2*x + 2)*y), dict=True, symbols=[]) == \ + {'coeff': 1, x: 2*x + 2, y: y} + assert separatevars(((2*x + 2)*y), dict=True) == \ + {'coeff': 1, x: 2*x + 2, y: y} + assert separatevars(((2*x + 2)*y), dict=True, symbols=None) == \ + {'coeff': y*(2*x + 2)} + # not separable + assert separatevars(3, dict=True) is None + assert separatevars(2*x + y, dict=True, symbols=()) is None + assert separatevars(2*x + y, dict=True) is None + assert separatevars(2*x + y, dict=True, symbols=None) == {'coeff': 2*x + y} + # issue 4808 + n, m = symbols('n,m', commutative=False) + assert separatevars(m + n*m) == (1 + n)*m + assert separatevars(x + x*n) == x*(1 + n) + # issue 4910 + f = Function('f') + assert separatevars(f(x) + x*f(x)) == f(x) + x*f(x) + # a noncommutable object present + eq = x*(1 + hyper((), (), y*z)) + assert separatevars(eq) == eq + + s = separatevars(abs(x*y)) + assert s == abs(x)*abs(y) and s.is_Mul + z = cos(1)**2 + sin(1)**2 - 1 + a = abs(x*z) + s = separatevars(a) + assert not a.is_Mul and s.is_Mul and s == abs(x)*abs(z) + s = separatevars(abs(x*y*z)) + assert s == abs(x)*abs(y)*abs(z) + + # abs(x+y)/abs(z) would be better but we test this here to + # see that it doesn't raise + assert separatevars(abs((x+y)/z)) == abs((x+y)/z) + + +def test_separatevars_advanced_factor(): + x, y, z = symbols('x,y,z') + assert separatevars(1 + log(x)*log(y) + log(x) + log(y)) == \ + (log(x) + 1)*(log(y) + 1) + assert separatevars(1 + x - log(z) - x*log(z) - exp(y)*log(z) - + x*exp(y)*log(z) + x*exp(y) + exp(y)) == \ + -((x + 1)*(log(z) - 1)*(exp(y) + 1)) + x, y = symbols('x,y', positive=True) + assert separatevars(1 + log(x**log(y)) + log(x*y)) == \ + (log(x) + 1)*(log(y) + 1) + + +def test_hypersimp(): + n, k = symbols('n,k', integer=True) + + assert hypersimp(factorial(k), k) == k + 1 + assert hypersimp(factorial(k**2), k) is None + + assert hypersimp(1/factorial(k), k) == 1/(k + 1) + + assert hypersimp(2**k/factorial(k)**2, k) == 2/(k + 1)**2 + + assert hypersimp(binomial(n, k), k) == (n - k)/(k + 1) + assert hypersimp(binomial(n + 1, k), k) == (n - k + 1)/(k + 1) + + term = (4*k + 1)*factorial(k)/factorial(2*k + 1) + assert hypersimp(term, k) == S.Half*((4*k + 5)/(3 + 14*k + 8*k**2)) + + term = 1/((2*k - 1)*factorial(2*k + 1)) + assert hypersimp(term, k) == (k - S.Half)/((k + 1)*(2*k + 1)*(2*k + 3)) + + term = binomial(n, k)*(-1)**k/factorial(k) + assert hypersimp(term, k) == (k - n)/(k + 1)**2 + + +def test_nsimplify(): + x = Symbol("x") + assert nsimplify(0) == 0 + assert nsimplify(-1) == -1 + assert nsimplify(1) == 1 + assert nsimplify(1 + x) == 1 + x + assert nsimplify(2.7) == Rational(27, 10) + assert nsimplify(1 - GoldenRatio) == (1 - sqrt(5))/2 + assert nsimplify((1 + sqrt(5))/4, [GoldenRatio]) == GoldenRatio/2 + assert nsimplify(2/GoldenRatio, [GoldenRatio]) == 2*GoldenRatio - 2 + assert nsimplify(exp(pi*I*Rational(5, 3), evaluate=False)) == \ + sympify('1/2 - sqrt(3)*I/2') + assert nsimplify(sin(pi*Rational(3, 5), evaluate=False)) == \ + sympify('sqrt(sqrt(5)/8 + 5/8)') + assert nsimplify(sqrt(atan('1', evaluate=False))*(2 + I), [pi]) == \ + sqrt(pi) + sqrt(pi)/2*I + assert nsimplify(2 + exp(2*atan('1/4')*I)) == sympify('49/17 + 8*I/17') + assert nsimplify(pi, tolerance=0.01) == Rational(22, 7) + assert nsimplify(pi, tolerance=0.001) == Rational(355, 113) + assert nsimplify(0.33333, tolerance=1e-4) == Rational(1, 3) + assert nsimplify(2.0**(1/3.), tolerance=0.001) == Rational(635, 504) + assert nsimplify(2.0**(1/3.), tolerance=0.001, full=True) == \ + 2**Rational(1, 3) + assert nsimplify(x + .5, rational=True) == S.Half + x + assert nsimplify(1/.3 + x, rational=True) == Rational(10, 3) + x + assert nsimplify(log(3).n(), rational=True) == \ + sympify('109861228866811/100000000000000') + assert nsimplify(Float(0.272198261287950), [pi, log(2)]) == pi*log(2)/8 + assert nsimplify(Float(0.272198261287950).n(3), [pi, log(2)]) == \ + -pi/4 - log(2) + Rational(7, 4) + assert nsimplify(x/7.0) == x/7 + assert nsimplify(pi/1e2) == pi/100 + assert nsimplify(pi/1e2, rational=False) == pi/100.0 + assert nsimplify(pi/1e-7) == 10000000*pi + assert not nsimplify( + factor(-3.0*z**2*(z**2)**(-2.5) + 3*(z**2)**(-1.5))).atoms(Float) + e = x**0.0 + assert e.is_Pow and nsimplify(x**0.0) == 1 + assert nsimplify(3.333333, tolerance=0.1, rational=True) == Rational(10, 3) + assert nsimplify(3.333333, tolerance=0.01, rational=True) == Rational(10, 3) + assert nsimplify(3.666666, tolerance=0.1, rational=True) == Rational(11, 3) + assert nsimplify(3.666666, tolerance=0.01, rational=True) == Rational(11, 3) + assert nsimplify(33, tolerance=10, rational=True) == Rational(33) + assert nsimplify(33.33, tolerance=10, rational=True) == Rational(30) + assert nsimplify(37.76, tolerance=10, rational=True) == Rational(40) + assert nsimplify(-203.1) == Rational(-2031, 10) + assert nsimplify(.2, tolerance=0) == Rational(1, 5) + assert nsimplify(-.2, tolerance=0) == Rational(-1, 5) + assert nsimplify(.2222, tolerance=0) == Rational(1111, 5000) + assert nsimplify(-.2222, tolerance=0) == Rational(-1111, 5000) + # issue 7211, PR 4112 + assert nsimplify(S(2e-8)) == Rational(1, 50000000) + # issue 7322 direct test + assert nsimplify(1e-42, rational=True) != 0 + # issue 10336 + inf = Float('inf') + infs = (-oo, oo, inf, -inf) + for zi in infs: + ans = sign(zi)*oo + assert nsimplify(zi) == ans + assert nsimplify(zi + x) == x + ans + + assert nsimplify(0.33333333, rational=True, rational_conversion='exact') == Rational(0.33333333) + + # Make sure nsimplify on expressions uses full precision + assert nsimplify(pi.evalf(100)*x, rational_conversion='exact').evalf(100) == pi.evalf(100)*x + + +def test_issue_9448(): + tmp = sympify("1/(1 - (-1)**(2/3) - (-1)**(1/3)) + 1/(1 + (-1)**(2/3) + (-1)**(1/3))") + assert nsimplify(tmp) == S.Half + + +def test_extract_minus_sign(): + x = Symbol("x") + y = Symbol("y") + a = Symbol("a") + b = Symbol("b") + assert simplify(-x/-y) == x/y + assert simplify(-x/y) == -x/y + assert simplify(x/y) == x/y + assert simplify(x/-y) == -x/y + assert simplify(-x/0) == zoo*x + assert simplify(Rational(-5, 0)) is zoo + assert simplify(-a*x/(-y - b)) == a*x/(b + y) + + +def test_diff(): + x = Symbol("x") + y = Symbol("y") + f = Function("f") + g = Function("g") + assert simplify(g(x).diff(x)*f(x).diff(x) - f(x).diff(x)*g(x).diff(x)) == 0 + assert simplify(2*f(x)*f(x).diff(x) - diff(f(x)**2, x)) == 0 + assert simplify(diff(1/f(x), x) + f(x).diff(x)/f(x)**2) == 0 + assert simplify(f(x).diff(x, y) - f(x).diff(y, x)) == 0 + + +def test_logcombine_1(): + x, y = symbols("x,y") + a = Symbol("a") + z, w = symbols("z,w", positive=True) + b = Symbol("b", real=True) + assert logcombine(log(x) + 2*log(y)) == log(x) + 2*log(y) + assert logcombine(log(x) + 2*log(y), force=True) == log(x*y**2) + assert logcombine(a*log(w) + log(z)) == a*log(w) + log(z) + assert logcombine(b*log(z) + b*log(x)) == log(z**b) + b*log(x) + assert logcombine(b*log(z) - log(w)) == log(z**b/w) + assert logcombine(log(x)*log(z)) == log(x)*log(z) + assert logcombine(log(w)*log(x)) == log(w)*log(x) + assert logcombine(cos(-2*log(z) + b*log(w))) in [cos(log(w**b/z**2)), + cos(log(z**2/w**b))] + assert logcombine(log(log(x) - log(y)) - log(z), force=True) == \ + log(log(x/y)/z) + assert logcombine((2 + I)*log(x), force=True) == (2 + I)*log(x) + assert logcombine((x**2 + log(x) - log(y))/(x*y), force=True) == \ + (x**2 + log(x/y))/(x*y) + # the following could also give log(z*x**log(y**2)), what we + # are testing is that a canonical result is obtained + assert logcombine(log(x)*2*log(y) + log(z), force=True) == \ + log(z*y**log(x**2)) + assert logcombine((x*y + sqrt(x**4 + y**4) + log(x) - log(y))/(pi*x**Rational(2, 3)* + sqrt(y)**3), force=True) == ( + x*y + sqrt(x**4 + y**4) + log(x/y))/(pi*x**Rational(2, 3)*y**Rational(3, 2)) + assert logcombine(gamma(-log(x/y))*acos(-log(x/y)), force=True) == \ + acos(-log(x/y))*gamma(-log(x/y)) + + assert logcombine(2*log(z)*log(w)*log(x) + log(z) + log(w)) == \ + log(z**log(w**2))*log(x) + log(w*z) + assert logcombine(3*log(w) + 3*log(z)) == log(w**3*z**3) + assert logcombine(x*(y + 1) + log(2) + log(3)) == x*(y + 1) + log(6) + assert logcombine((x + y)*log(w) + (-x - y)*log(3)) == (x + y)*log(w/3) + # a single unknown can combine + assert logcombine(log(x) + log(2)) == log(2*x) + eq = log(abs(x)) + log(abs(y)) + assert logcombine(eq) == eq + reps = {x: 0, y: 0} + assert log(abs(x)*abs(y)).subs(reps) != eq.subs(reps) + + +def test_logcombine_complex_coeff(): + i = Integral((sin(x**2) + cos(x**3))/x, x) + assert logcombine(i, force=True) == i + assert logcombine(i + 2*log(x), force=True) == \ + i + log(x**2) + + +def test_issue_5950(): + x, y = symbols("x,y", positive=True) + assert logcombine(log(3) - log(2)) == log(Rational(3,2), evaluate=False) + assert logcombine(log(x) - log(y)) == log(x/y) + assert logcombine(log(Rational(3,2), evaluate=False) - log(2)) == \ + log(Rational(3,4), evaluate=False) + + +def test_posify(): + x = symbols('x') + + assert str(posify( + x + + Symbol('p', positive=True) + + Symbol('n', negative=True))) == '(_x + n + p, {_x: x})' + + eq, rep = posify(1/x) + assert log(eq).expand().subs(rep) == -log(x) + assert str(posify([x, 1 + x])) == '([_x, _x + 1], {_x: x})' + + p = symbols('p', positive=True) + n = symbols('n', negative=True) + orig = [x, n, p] + modified, reps = posify(orig) + assert str(modified) == '[_x, n, p]' + assert [w.subs(reps) for w in modified] == orig + + assert str(Integral(posify(1/x + y)[0], (y, 1, 3)).expand()) == \ + 'Integral(1/_x, (y, 1, 3)) + Integral(_y, (y, 1, 3))' + assert str(Sum(posify(1/x**n)[0], (n,1,3)).expand()) == \ + 'Sum(_x**(-n), (n, 1, 3))' + + A = Matrix([[1, 2, 3], [4, 5, 6 * Abs(x)]]) + Ap, rep = posify(A) + assert Ap == A.subs(*reversed(rep.popitem())) + + # issue 16438 + k = Symbol('k', finite=True) + eq, rep = posify(k) + assert eq.assumptions0 == {'positive': True, 'zero': False, 'imaginary': False, + 'nonpositive': False, 'commutative': True, 'hermitian': True, 'real': True, 'nonzero': True, + 'nonnegative': True, 'negative': False, 'complex': True, 'finite': True, + 'infinite': False, 'extended_real':True, 'extended_negative': False, + 'extended_nonnegative': True, 'extended_nonpositive': False, + 'extended_nonzero': True, 'extended_positive': True} + + +def test_issue_4194(): + # simplify should call cancel + f = Function('f') + assert simplify((4*x + 6*f(y))/(2*x + 3*f(y))) == 2 + + +@XFAIL +def test_simplify_float_vs_integer(): + # Test for issue 4473: + # https://github.com/sympy/sympy/issues/4473 + assert simplify(x**2.0 - x**2) == 0 + assert simplify(x**2 - x**2.0) == 0 + + +def test_as_content_primitive(): + assert (x/2 + y).as_content_primitive() == (S.Half, x + 2*y) + assert (x/2 + y).as_content_primitive(clear=False) == (S.One, x/2 + y) + assert (y*(x/2 + y)).as_content_primitive() == (S.Half, y*(x + 2*y)) + assert (y*(x/2 + y)).as_content_primitive(clear=False) == (S.One, y*(x/2 + y)) + + # although the _as_content_primitive methods do not alter the underlying structure, + # the as_content_primitive function will touch up the expression and join + # bases that would otherwise have not been joined. + assert (x*(2 + 2*x)*(3*x + 3)**2).as_content_primitive() == \ + (18, x*(x + 1)**3) + assert (2 + 2*x + 2*y*(3 + 3*y)).as_content_primitive() == \ + (2, x + 3*y*(y + 1) + 1) + assert ((2 + 6*x)**2).as_content_primitive() == \ + (4, (3*x + 1)**2) + assert ((2 + 6*x)**(2*y)).as_content_primitive() == \ + (1, (_keep_coeff(S(2), (3*x + 1)))**(2*y)) + assert (5 + 10*x + 2*y*(3 + 3*y)).as_content_primitive() == \ + (1, 10*x + 6*y*(y + 1) + 5) + assert (5*(x*(1 + y)) + 2*x*(3 + 3*y)).as_content_primitive() == \ + (11, x*(y + 1)) + assert ((5*(x*(1 + y)) + 2*x*(3 + 3*y))**2).as_content_primitive() == \ + (121, x**2*(y + 1)**2) + assert (y**2).as_content_primitive() == \ + (1, y**2) + assert (S.Infinity).as_content_primitive() == (1, oo) + eq = x**(2 + y) + assert (eq).as_content_primitive() == (1, eq) + assert (S.Half**(2 + x)).as_content_primitive() == (Rational(1, 4), 2**-x) + assert (Rational(-1, 2)**(2 + x)).as_content_primitive() == \ + (Rational(1, 4), (Rational(-1, 2))**x) + assert (Rational(-1, 2)**(2 + x)).as_content_primitive() == \ + (Rational(1, 4), Rational(-1, 2)**x) + assert (4**((1 + y)/2)).as_content_primitive() == (2, 4**(y/2)) + assert (3**((1 + y)/2)).as_content_primitive() == \ + (1, 3**(Mul(S.Half, 1 + y, evaluate=False))) + assert (5**Rational(3, 4)).as_content_primitive() == (1, 5**Rational(3, 4)) + assert (5**Rational(7, 4)).as_content_primitive() == (5, 5**Rational(3, 4)) + assert Add(z*Rational(5, 7), 0.5*x, y*Rational(3, 2), evaluate=False).as_content_primitive() == \ + (Rational(1, 14), 7.0*x + 21*y + 10*z) + assert (2**Rational(3, 4) + 2**Rational(1, 4)*sqrt(3)).as_content_primitive(radical=True) == \ + (1, 2**Rational(1, 4)*(sqrt(2) + sqrt(3))) + + +def test_signsimp(): + e = x*(-x + 1) + x*(x - 1) + assert signsimp(Eq(e, 0)) is S.true + assert Abs(x - 1) == Abs(1 - x) + assert signsimp(y - x) == y - x + assert signsimp(y - x, evaluate=False) == Mul(-1, x - y, evaluate=False) + + +def test_besselsimp(): + from sympy.functions.special.bessel import (besseli, besselj, bessely) + from sympy.integrals.transforms import cosine_transform + assert besselsimp(exp(-I*pi*y/2)*besseli(y, z*exp_polar(I*pi/2))) == \ + besselj(y, z) + assert besselsimp(exp(-I*pi*a/2)*besseli(a, 2*sqrt(x)*exp_polar(I*pi/2))) == \ + besselj(a, 2*sqrt(x)) + assert besselsimp(sqrt(2)*sqrt(pi)*x**Rational(1, 4)*exp(I*pi/4)*exp(-I*pi*a/2) * + besseli(Rational(-1, 2), sqrt(x)*exp_polar(I*pi/2)) * + besseli(a, sqrt(x)*exp_polar(I*pi/2))/2) == \ + besselj(a, sqrt(x)) * cos(sqrt(x)) + assert besselsimp(besseli(Rational(-1, 2), z)) == \ + sqrt(2)*cosh(z)/(sqrt(pi)*sqrt(z)) + assert besselsimp(besseli(a, z*exp_polar(-I*pi/2))) == \ + exp(-I*pi*a/2)*besselj(a, z) + assert cosine_transform(1/t*sin(a/t), t, y) == \ + sqrt(2)*sqrt(pi)*besselj(0, 2*sqrt(a)*sqrt(y))/2 + + assert besselsimp(x**2*(a*(-2*besselj(5*I, x) + besselj(-2 + 5*I, x) + + besselj(2 + 5*I, x)) + b*(-2*bessely(5*I, x) + bessely(-2 + 5*I, x) + + bessely(2 + 5*I, x)))/4 + x*(a*(besselj(-1 + 5*I, x)/2 - besselj(1 + 5*I, x)/2) + + b*(bessely(-1 + 5*I, x)/2 - bessely(1 + 5*I, x)/2)) + (x**2 + 25)*(a*besselj(5*I, x) + + b*bessely(5*I, x))) == 0 + + assert besselsimp(81*x**2*(a*(besselj(Rational(-5, 3), 9*x) - 2*besselj(Rational(1, 3), 9*x) + besselj(Rational(7, 3), 9*x)) + + b*(bessely(Rational(-5, 3), 9*x) - 2*bessely(Rational(1, 3), 9*x) + bessely(Rational(7, 3), 9*x)))/4 + x*(a*(9*besselj(Rational(-2, 3), 9*x)/2 + - 9*besselj(Rational(4, 3), 9*x)/2) + b*(9*bessely(Rational(-2, 3), 9*x)/2 - 9*bessely(Rational(4, 3), 9*x)/2)) + + (81*x**2 - Rational(1, 9))*(a*besselj(Rational(1, 3), 9*x) + b*bessely(Rational(1, 3), 9*x))) == 0 + + assert besselsimp(besselj(a-1,x) + besselj(a+1, x) - 2*a*besselj(a, x)/x) == 0 + + assert besselsimp(besselj(a-1,x) + besselj(a+1, x) + besselj(a, x)) == (2*a + x)*besselj(a, x)/x + + assert besselsimp(x**2* besselj(a,x) + x**3*besselj(a+1, x) + besselj(a+2, x)) == \ + 2*a*x*besselj(a + 1, x) + x**3*besselj(a + 1, x) - x**2*besselj(a + 2, x) + 2*x*besselj(a + 1, x) + besselj(a + 2, x) + +def test_Piecewise(): + e1 = x*(x + y) - y*(x + y) + e2 = sin(x)**2 + cos(x)**2 + e3 = expand((x + y)*y/x) + s1 = simplify(e1) + s2 = simplify(e2) + s3 = simplify(e3) + assert simplify(Piecewise((e1, x < e2), (e3, True))) == \ + Piecewise((s1, x < s2), (s3, True)) + + +def test_polymorphism(): + class A(Basic): + def _eval_simplify(x, **kwargs): + return S.One + + a = A(S(5), S(2)) + assert simplify(a) == 1 + + +def test_issue_from_PR1599(): + n1, n2, n3, n4 = symbols('n1 n2 n3 n4', negative=True) + assert simplify(I*sqrt(n1)) == -sqrt(-n1) + + +def test_issue_6811(): + eq = (x + 2*y)*(2*x + 2) + assert simplify(eq) == (x + 1)*(x + 2*y)*2 + # reject the 2-arg Mul -- these are a headache for test writing + assert simplify(eq.expand()) == \ + 2*x**2 + 4*x*y + 2*x + 4*y + + +def test_issue_6920(): + e = [cos(x) + I*sin(x), cos(x) - I*sin(x), + cosh(x) - sinh(x), cosh(x) + sinh(x)] + ok = [exp(I*x), exp(-I*x), exp(-x), exp(x)] + # wrap in f to show that the change happens wherever ei occurs + f = Function('f') + assert [simplify(f(ei)).args[0] for ei in e] == ok + + +def test_issue_7001(): + from sympy.abc import r, R + assert simplify(-(r*Piecewise((pi*Rational(4, 3), r <= R), + (-8*pi*R**3/(3*r**3), True)) + 2*Piecewise((pi*r*Rational(4, 3), r <= R), + (4*pi*R**3/(3*r**2), True)))/(4*pi*r)) == \ + Piecewise((-1, r <= R), (0, True)) + + +def test_inequality_no_auto_simplify(): + # no simplify on creation but can be simplified + lhs = cos(x)**2 + sin(x)**2 + rhs = 2 + e = Lt(lhs, rhs, evaluate=False) + assert e is not S.true + assert simplify(e) + + +def test_issue_9398(): + from sympy.core.numbers import Number + from sympy.polys.polytools import cancel + assert cancel(1e-14) != 0 + assert cancel(1e-14*I) != 0 + + assert simplify(1e-14) != 0 + assert simplify(1e-14*I) != 0 + + assert (I*Number(1.)*Number(10)**Number(-14)).simplify() != 0 + + assert cancel(1e-20) != 0 + assert cancel(1e-20*I) != 0 + + assert simplify(1e-20) != 0 + assert simplify(1e-20*I) != 0 + + assert cancel(1e-100) != 0 + assert cancel(1e-100*I) != 0 + + assert simplify(1e-100) != 0 + assert simplify(1e-100*I) != 0 + + f = Float("1e-1000") + assert cancel(f) != 0 + assert cancel(f*I) != 0 + + assert simplify(f) != 0 + assert simplify(f*I) != 0 + + +def test_issue_9324_simplify(): + M = MatrixSymbol('M', 10, 10) + e = M[0, 0] + M[5, 4] + 1304 + assert simplify(e) == e + + +def test_issue_9817_simplify(): + # simplify on trace of substituted explicit quadratic form of matrix + # expressions (a scalar) should return without errors (AttributeError) + # See issue #9817 and #9190 for the original bug more discussion on this + from sympy.matrices.expressions import Identity, trace + v = MatrixSymbol('v', 3, 1) + A = MatrixSymbol('A', 3, 3) + x = Matrix([i + 1 for i in range(3)]) + X = Identity(3) + quadratic = v.T * A * v + assert simplify((trace(quadratic.as_explicit())).xreplace({v:x, A:X})) == 14 + + +def test_issue_13474(): + x = Symbol('x') + assert simplify(x + csch(sinc(1))) == x + csch(sinc(1)) + + +@_both_exp_pow +def test_simplify_function_inverse(): + # "inverse" attribute does not guarantee that f(g(x)) is x + # so this simplification should not happen automatically. + # See issue #12140 + x, y = symbols('x, y') + g = Function('g') + + class f(Function): + def inverse(self, argindex=1): + return g + + assert simplify(f(g(x))) == f(g(x)) + assert inversecombine(f(g(x))) == x + assert simplify(f(g(x)), inverse=True) == x + assert simplify(f(g(sin(x)**2 + cos(x)**2)), inverse=True) == 1 + assert simplify(f(g(x, y)), inverse=True) == f(g(x, y)) + assert unchanged(asin, sin(x)) + assert simplify(asin(sin(x))) == asin(sin(x)) + assert simplify(2*asin(sin(3*x)), inverse=True) == 6*x + assert simplify(log(exp(x))) == log(exp(x)) + assert simplify(log(exp(x)), inverse=True) == x + assert simplify(exp(log(x)), inverse=True) == x + assert simplify(log(exp(x), 2), inverse=True) == x/log(2) + assert simplify(log(exp(x), 2, evaluate=False), inverse=True) == x/log(2) + + +def test_clear_coefficients(): + from sympy.simplify.simplify import clear_coefficients + assert clear_coefficients(4*y*(6*x + 3)) == (y*(2*x + 1), 0) + assert clear_coefficients(4*y*(6*x + 3) - 2) == (y*(2*x + 1), Rational(1, 6)) + assert clear_coefficients(4*y*(6*x + 3) - 2, x) == (y*(2*x + 1), x/12 + Rational(1, 6)) + assert clear_coefficients(sqrt(2) - 2) == (sqrt(2), 2) + assert clear_coefficients(4*sqrt(2) - 2) == (sqrt(2), S.Half) + assert clear_coefficients(S(3), x) == (0, x - 3) + assert clear_coefficients(S.Infinity, x) == (S.Infinity, x) + assert clear_coefficients(-S.Pi, x) == (S.Pi, -x) + assert clear_coefficients(2 - S.Pi/3, x) == (pi, -3*x + 6) + +def test_nc_simplify(): + from sympy.simplify.simplify import nc_simplify + from sympy.matrices.expressions import MatPow, Identity + from sympy.core import Pow + from functools import reduce + + a, b, c, d = symbols('a b c d', commutative = False) + x = Symbol('x') + A = MatrixSymbol("A", x, x) + B = MatrixSymbol("B", x, x) + C = MatrixSymbol("C", x, x) + D = MatrixSymbol("D", x, x) + subst = {a: A, b: B, c: C, d:D} + funcs = {Add: lambda x,y: x+y, Mul: lambda x,y: x*y } + + def _to_matrix(expr): + if expr in subst: + return subst[expr] + if isinstance(expr, Pow): + return MatPow(_to_matrix(expr.args[0]), expr.args[1]) + elif isinstance(expr, (Add, Mul)): + return reduce(funcs[expr.func],[_to_matrix(a) for a in expr.args]) + else: + return expr*Identity(x) + + def _check(expr, simplified, deep=True, matrix=True): + assert nc_simplify(expr, deep=deep) == simplified + assert expand(expr) == expand(simplified) + if matrix: + m_simp = _to_matrix(simplified).doit(inv_expand=False) + assert nc_simplify(_to_matrix(expr), deep=deep) == m_simp + + _check(a*b*a*b*a*b*c*(a*b)**3*c, ((a*b)**3*c)**2) + _check(a*b*(a*b)**-2*a*b, 1) + _check(a**2*b*a*b*a*b*(a*b)**-1, a*(a*b)**2, matrix=False) + _check(b*a*b**2*a*b**2*a*b**2, b*(a*b**2)**3) + _check(a*b*a**2*b*a**2*b*a**3, (a*b*a)**3*a**2) + _check(a**2*b*a**4*b*a**4*b*a**2, (a**2*b*a**2)**3) + _check(a**3*b*a**4*b*a**4*b*a, a**3*(b*a**4)**3*a**-3) + _check(a*b*a*b + a*b*c*x*a*b*c, (a*b)**2 + x*(a*b*c)**2) + _check(a*b*a*b*c*a*b*a*b*c, ((a*b)**2*c)**2) + _check(b**-1*a**-1*(a*b)**2, a*b) + _check(a**-1*b*c**-1, (c*b**-1*a)**-1) + expr = a**3*b*a**4*b*a**4*b*a**2*b*a**2*(b*a**2)**2*b*a**2*b*a**2 + for _ in range(10): + expr *= a*b + _check(expr, a**3*(b*a**4)**2*(b*a**2)**6*(a*b)**10) + _check((a*b*a*b)**2, (a*b*a*b)**2, deep=False) + _check(a*b*(c*d)**2, a*b*(c*d)**2) + expr = b**-1*(a**-1*b**-1 - a**-1*c*b**-1)**-1*a**-1 + assert nc_simplify(expr) == (1-c)**-1 + # commutative expressions should be returned without an error + assert nc_simplify(2*x**2) == 2*x**2 + +def test_issue_15965(): + A = Sum(z*x**y, (x, 1, a)) + anew = z*Sum(x**y, (x, 1, a)) + B = Integral(x*y, x) + bdo = x**2*y/2 + assert simplify(A + B) == anew + bdo + assert simplify(A) == anew + assert simplify(B) == bdo + assert simplify(B, doit=False) == y*Integral(x, x) + + +def test_issue_17137(): + assert simplify(cos(x)**I) == cos(x)**I + assert simplify(cos(x)**(2 + 3*I)) == cos(x)**(2 + 3*I) + + +def test_issue_21869(): + x = Symbol('x', real=True) + y = Symbol('y', real=True) + expr = And(Eq(x**2, 4), Le(x, y)) + assert expr.simplify() == expr + + expr = And(Eq(x**2, 4), Eq(x, 2)) + assert expr.simplify() == Eq(x, 2) + + expr = And(Eq(x**3, x**2), Eq(x, 1)) + assert expr.simplify() == Eq(x, 1) + + expr = And(Eq(sin(x), x**2), Eq(x, 0)) + assert expr.simplify() == Eq(x, 0) + + expr = And(Eq(x**3, x**2), Eq(x, 2)) + assert expr.simplify() == S.false + + expr = And(Eq(y, x**2), Eq(x, 1)) + assert expr.simplify() == And(Eq(y,1), Eq(x, 1)) + + expr = And(Eq(y**2, 1), Eq(y, x**2), Eq(x, 1)) + assert expr.simplify() == And(Eq(y,1), Eq(x, 1)) + + expr = And(Eq(y**2, 4), Eq(y, 2*x**2), Eq(x, 1)) + assert expr.simplify() == And(Eq(y,2), Eq(x, 1)) + + expr = And(Eq(y**2, 4), Eq(y, x**2), Eq(x, 1)) + assert expr.simplify() == S.false + + +def test_issue_7971_21740(): + z = Integral(x, (x, 1, 1)) + assert z != 0 + assert simplify(z) is S.Zero + assert simplify(S.Zero) is S.Zero + z = simplify(Float(0)) + assert z is not S.Zero and z == 0.0 + + +@slow +def test_issue_17141_slow(): + # Should not give RecursionError + assert simplify((2**acos(I+1)**2).rewrite('log')) == 2**((pi + 2*I*log(-1 + + sqrt(1 - 2*I) + I))**2/4) + + +def test_issue_17141(): + # Check that there is no RecursionError + assert simplify(x**(1 / acos(I))) == x**(2/(pi - 2*I*log(1 + sqrt(2)))) + assert simplify(acos(-I)**2*acos(I)**2) == \ + log(1 + sqrt(2))**4 + pi**2*log(1 + sqrt(2))**2/2 + pi**4/16 + assert simplify(2**acos(I)**2) == 2**((pi - 2*I*log(1 + sqrt(2)))**2/4) + p = 2**acos(I+1)**2 + assert simplify(p) == p + + +def test_simplify_kroneckerdelta(): + i, j = symbols("i j") + K = KroneckerDelta + + assert simplify(K(i, j)) == K(i, j) + assert simplify(K(0, j)) == K(0, j) + assert simplify(K(i, 0)) == K(i, 0) + + assert simplify(K(0, j).rewrite(Piecewise) * K(1, j)) == 0 + assert simplify(K(1, i) + Piecewise((1, Eq(j, 2)), (0, True))) == K(1, i) + K(2, j) + + # issue 17214 + assert simplify(K(0, j) * K(1, j)) == 0 + + n = Symbol('n', integer=True) + assert simplify(K(0, n) * K(1, n)) == 0 + + M = Matrix(4, 4, lambda i, j: K(j - i, n) if i <= j else 0) + assert simplify(M**2) == Matrix([[K(0, n), 0, K(1, n), 0], + [0, K(0, n), 0, K(1, n)], + [0, 0, K(0, n), 0], + [0, 0, 0, K(0, n)]]) + assert simplify(eye(1) * KroneckerDelta(0, n) * + KroneckerDelta(1, n)) == Matrix([[0]]) + + assert simplify(S.Infinity * KroneckerDelta(0, n) * + KroneckerDelta(1, n)) is S.NaN + + +def test_issue_17292(): + assert simplify(abs(x)/abs(x**2)) == 1/abs(x) + # this is bigger than the issue: check that deep processing works + assert simplify(5*abs((x**2 - 1)/(x - 1))) == 5*Abs(x + 1) + + +def test_issue_19822(): + expr = And(Gt(n-2, 1), Gt(n, 1)) + assert simplify(expr) == Gt(n, 3) + + +def test_issue_18645(): + expr = And(Ge(x, 3), Le(x, 3)) + assert simplify(expr) == Eq(x, 3) + expr = And(Eq(x, 3), Le(x, 3)) + assert simplify(expr) == Eq(x, 3) + + +@XFAIL +def test_issue_18642(): + i = Symbol("i", integer=True) + n = Symbol("n", integer=True) + expr = And(Eq(i, 2 * n), Le(i, 2*n -1)) + assert simplify(expr) == S.false + + +@XFAIL +def test_issue_18389(): + n = Symbol("n", integer=True) + expr = Eq(n, 0) | (n >= 1) + assert simplify(expr) == Ge(n, 0) + + +def test_issue_8373(): + x = Symbol('x', real=True) + assert simplify(Or(x < 1, x >= 1)) == S.true + + +def test_issue_7950(): + expr = And(Eq(x, 1), Eq(x, 2)) + assert simplify(expr) == S.false + + +def test_issue_22020(): + expr = I*pi/2 -oo + assert simplify(expr) == expr + # Used to throw an error + + +def test_issue_19484(): + assert simplify(sign(x) * Abs(x)) == x + + e = x + sign(x + x**3) + assert simplify(Abs(x + x**3)*e) == x**3 + x*Abs(x**3 + x) + x + + e = x**2 + sign(x**3 + 1) + assert simplify(Abs(x**3 + 1) * e) == x**3 + x**2*Abs(x**3 + 1) + 1 + + f = Function('f') + e = x + sign(x + f(x)**3) + assert simplify(Abs(x + f(x)**3) * e) == x*Abs(x + f(x)**3) + x + f(x)**3 + + +def test_issue_23543(): + # Used to give an error + x, y, z = symbols("x y z", commutative=False) + assert (x*(y + z/2)).simplify() == x*(2*y + z)/2 + + +def test_issue_11004(): + + def f(n): + return sqrt(2*pi*n) * (n/E)**n + + def m(n, k): + return f(n) / (f(n/k)**k) + + def p(n,k): + return m(n, k) / (k**n) + + N, k = symbols('N k') + half = Float('0.5', 4) + z = log(p(n, k) / p(n, k + 1)).expand(force=True) + r = simplify(z.subs(n, N).n(4)) + assert r == ( + half*k*log(k) + - half*k*log(k + 1) + + half*log(N) + - half*log(k + 1) + + Float(0.9189224, 4) + ) + + +def test_issue_19161(): + polynomial = Poly('x**2').simplify() + assert (polynomial-x**2).simplify() == 0 + + +def test_issue_22210(): + d = Symbol('d', integer=True) + expr = 2*Derivative(sin(x), (x, d)) + assert expr.simplify() == expr + + +def test_reduce_inverses_nc_pow(): + x, y = symbols("x y", commutative=True) + Z = symbols("Z", commutative=False) + assert simplify(2**Z * y**Z) == 2**Z * y**Z + assert simplify(x**Z * y**Z) == x**Z * y**Z + x, y = symbols("x y", positive=True) + assert expand((x*y)**Z) == x**Z * y**Z + assert simplify(x**Z * y**Z) == expand((x*y)**Z) + +def test_nc_recursion_coeff(): + X = symbols("X", commutative = False) + assert (2 * cos(pi/3) * X).simplify() == X + assert (2.0 * cos(pi/3) * X).simplify() == X diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_sqrtdenest.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_sqrtdenest.py new file mode 100644 index 0000000000000000000000000000000000000000..41c771bb2055a1199d349ae3649f33927d79313a --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_sqrtdenest.py @@ -0,0 +1,204 @@ +from sympy.core.mul import Mul +from sympy.core.numbers import (I, Integer, Rational) +from sympy.core.symbol import Symbol +from sympy.functions.elementary.miscellaneous import (root, sqrt) +from sympy.functions.elementary.trigonometric import cos +from sympy.integrals.integrals import Integral +from sympy.simplify.sqrtdenest import sqrtdenest +from sympy.simplify.sqrtdenest import ( + _subsets as subsets, _sqrt_numeric_denest) + +r2, r3, r5, r6, r7, r10, r15, r29 = [sqrt(x) for x in (2, 3, 5, 6, 7, 10, + 15, 29)] + + +def test_sqrtdenest(): + d = {sqrt(5 + 2 * r6): r2 + r3, + sqrt(5. + 2 * r6): sqrt(5. + 2 * r6), + sqrt(5. + 4*sqrt(5 + 2 * r6)): sqrt(5.0 + 4*r2 + 4*r3), + sqrt(r2): sqrt(r2), + sqrt(5 + r7): sqrt(5 + r7), + sqrt(3 + sqrt(5 + 2*r7)): + 3*r2*(5 + 2*r7)**Rational(1, 4)/(2*sqrt(6 + 3*r7)) + + r2*sqrt(6 + 3*r7)/(2*(5 + 2*r7)**Rational(1, 4)), + sqrt(3 + 2*r3): 3**Rational(3, 4)*(r6/2 + 3*r2/2)/3} + for i in d: + assert sqrtdenest(i) == d[i], i + + +def test_sqrtdenest2(): + assert sqrtdenest(sqrt(16 - 2*r29 + 2*sqrt(55 - 10*r29))) == \ + r5 + sqrt(11 - 2*r29) + e = sqrt(-r5 + sqrt(-2*r29 + 2*sqrt(-10*r29 + 55) + 16)) + assert sqrtdenest(e) == root(-2*r29 + 11, 4) + r = sqrt(1 + r7) + assert sqrtdenest(sqrt(1 + r)) == sqrt(1 + r) + e = sqrt(((1 + sqrt(1 + 2*sqrt(3 + r2 + r5)))**2).expand()) + assert sqrtdenest(e) == 1 + sqrt(1 + 2*sqrt(r2 + r5 + 3)) + + assert sqrtdenest(sqrt(5*r3 + 6*r2)) == \ + sqrt(2)*root(3, 4) + root(3, 4)**3 + + assert sqrtdenest(sqrt(((1 + r5 + sqrt(1 + r3))**2).expand())) == \ + 1 + r5 + sqrt(1 + r3) + + assert sqrtdenest(sqrt(((1 + r5 + r7 + sqrt(1 + r3))**2).expand())) == \ + 1 + sqrt(1 + r3) + r5 + r7 + + e = sqrt(((1 + cos(2) + cos(3) + sqrt(1 + r3))**2).expand()) + assert sqrtdenest(e) == cos(3) + cos(2) + 1 + sqrt(1 + r3) + + e = sqrt(-2*r10 + 2*r2*sqrt(-2*r10 + 11) + 14) + assert sqrtdenest(e) == sqrt(-2*r10 - 2*r2 + 4*r5 + 14) + + # check that the result is not more complicated than the input + z = sqrt(-2*r29 + cos(2) + 2*sqrt(-10*r29 + 55) + 16) + assert sqrtdenest(z) == z + + assert sqrtdenest(sqrt(r6 + sqrt(15))) == sqrt(r6 + sqrt(15)) + + z = sqrt(15 - 2*sqrt(31) + 2*sqrt(55 - 10*r29)) + assert sqrtdenest(z) == z + + +def test_sqrtdenest_rec(): + assert sqrtdenest(sqrt(-4*sqrt(14) - 2*r6 + 4*sqrt(21) + 33)) == \ + -r2 + r3 + 2*r7 + assert sqrtdenest(sqrt(-28*r7 - 14*r5 + 4*sqrt(35) + 82)) == \ + -7 + r5 + 2*r7 + assert sqrtdenest(sqrt(6*r2/11 + 2*sqrt(22)/11 + 6*sqrt(11)/11 + 2)) == \ + sqrt(11)*(r2 + 3 + sqrt(11))/11 + assert sqrtdenest(sqrt(468*r3 + 3024*r2 + 2912*r6 + 19735)) == \ + 9*r3 + 26 + 56*r6 + z = sqrt(-490*r3 - 98*sqrt(115) - 98*sqrt(345) - 2107) + assert sqrtdenest(z) == sqrt(-1)*(7*r5 + 7*r15 + 7*sqrt(23)) + z = sqrt(-4*sqrt(14) - 2*r6 + 4*sqrt(21) + 34) + assert sqrtdenest(z) == z + assert sqrtdenest(sqrt(-8*r2 - 2*r5 + 18)) == -r10 + 1 + r2 + r5 + assert sqrtdenest(sqrt(8*r2 + 2*r5 - 18)) == \ + sqrt(-1)*(-r10 + 1 + r2 + r5) + assert sqrtdenest(sqrt(8*r2/3 + 14*r5/3 + Rational(154, 9))) == \ + -r10/3 + r2 + r5 + 3 + assert sqrtdenest(sqrt(sqrt(2*r6 + 5) + sqrt(2*r7 + 8))) == \ + sqrt(1 + r2 + r3 + r7) + assert sqrtdenest(sqrt(4*r15 + 8*r5 + 12*r3 + 24)) == 1 + r3 + r5 + r15 + + w = 1 + r2 + r3 + r5 + r7 + assert sqrtdenest(sqrt((w**2).expand())) == w + z = sqrt((w**2).expand() + 1) + assert sqrtdenest(z) == z + + z = sqrt(2*r10 + 6*r2 + 4*r5 + 12 + 10*r15 + 30*r3) + assert sqrtdenest(z) == z + + +def test_issue_6241(): + z = sqrt( -320 + 32*sqrt(5) + 64*r15) + assert sqrtdenest(z) == z + + +def test_sqrtdenest3(): + z = sqrt(13 - 2*r10 + 2*r2*sqrt(-2*r10 + 11)) + assert sqrtdenest(z) == -1 + r2 + r10 + assert sqrtdenest(z, max_iter=1) == -1 + sqrt(2) + sqrt(10) + z = sqrt(sqrt(r2 + 2) + 2) + assert sqrtdenest(z) == z + assert sqrtdenest(sqrt(-2*r10 + 4*r2*sqrt(-2*r10 + 11) + 20)) == \ + sqrt(-2*r10 - 4*r2 + 8*r5 + 20) + assert sqrtdenest(sqrt((112 + 70*r2) + (46 + 34*r2)*r5)) == \ + r10 + 5 + 4*r2 + 3*r5 + z = sqrt(5 + sqrt(2*r6 + 5)*sqrt(-2*r29 + 2*sqrt(-10*r29 + 55) + 16)) + r = sqrt(-2*r29 + 11) + assert sqrtdenest(z) == sqrt(r2*r + r3*r + r10 + r15 + 5) + + n = sqrt(2*r6/7 + 2*r7/7 + 2*sqrt(42)/7 + 2) + d = sqrt(16 - 2*r29 + 2*sqrt(55 - 10*r29)) + assert sqrtdenest(n/d) == r7*(1 + r6 + r7)/(Mul(7, (sqrt(-2*r29 + 11) + r5), + evaluate=False)) + + +def test_sqrtdenest4(): + # see Denest_en.pdf in https://github.com/sympy/sympy/issues/3192 + z = sqrt(8 - r2*sqrt(5 - r5) - sqrt(3)*(1 + r5)) + z1 = sqrtdenest(z) + c = sqrt(-r5 + 5) + z1 = ((-r15*c - r3*c + c + r5*c - r6 - r2 + r10 + sqrt(30))/4).expand() + assert sqrtdenest(z) == z1 + + z = sqrt(2*r2*sqrt(r2 + 2) + 5*r2 + 4*sqrt(r2 + 2) + 8) + assert sqrtdenest(z) == r2 + sqrt(r2 + 2) + 2 + + w = 2 + r2 + r3 + (1 + r3)*sqrt(2 + r2 + 5*r3) + z = sqrt((w**2).expand()) + assert sqrtdenest(z) == w.expand() + + +def test_sqrt_symbolic_denest(): + x = Symbol('x') + z = sqrt(((1 + sqrt(sqrt(2 + x) + 3))**2).expand()) + assert sqrtdenest(z) == sqrt((1 + sqrt(sqrt(2 + x) + 3))**2) + z = sqrt(((1 + sqrt(sqrt(2 + cos(1)) + 3))**2).expand()) + assert sqrtdenest(z) == 1 + sqrt(sqrt(2 + cos(1)) + 3) + z = ((1 + cos(2))**4 + 1).expand() + assert sqrtdenest(z) == z + z = sqrt(((1 + sqrt(sqrt(2 + cos(3*x)) + 3))**2 + 1).expand()) + assert sqrtdenest(z) == z + c = cos(3) + c2 = c**2 + assert sqrtdenest(sqrt(2*sqrt(1 + r3)*c + c2 + 1 + r3*c2)) == \ + -1 - sqrt(1 + r3)*c + ra = sqrt(1 + r3) + z = sqrt(20*ra*sqrt(3 + 3*r3) + 12*r3*ra*sqrt(3 + 3*r3) + 64*r3 + 112) + assert sqrtdenest(z) == z + + +def test_issue_5857(): + from sympy.abc import x, y + z = sqrt(1/(4*r3 + 7) + 1) + ans = (r2 + r6)/(r3 + 2) + assert sqrtdenest(z) == ans + assert sqrtdenest(1 + z) == 1 + ans + assert sqrtdenest(Integral(z + 1, (x, 1, 2))) == \ + Integral(1 + ans, (x, 1, 2)) + assert sqrtdenest(x + sqrt(y)) == x + sqrt(y) + ans = (r2 + r6)/(r3 + 2) + assert sqrtdenest(z) == ans + assert sqrtdenest(1 + z) == 1 + ans + assert sqrtdenest(Integral(z + 1, (x, 1, 2))) == \ + Integral(1 + ans, (x, 1, 2)) + assert sqrtdenest(x + sqrt(y)) == x + sqrt(y) + + +def test_subsets(): + assert subsets(1) == [[1]] + assert subsets(4) == [ + [1, 0, 0, 0], [0, 1, 0, 0], [1, 1, 0, 0], [0, 0, 1, 0], [1, 0, 1, 0], + [0, 1, 1, 0], [1, 1, 1, 0], [0, 0, 0, 1], [1, 0, 0, 1], [0, 1, 0, 1], + [1, 1, 0, 1], [0, 0, 1, 1], [1, 0, 1, 1], [0, 1, 1, 1], [1, 1, 1, 1]] + + +def test_issue_5653(): + assert sqrtdenest( + sqrt(2 + sqrt(2 + sqrt(2)))) == sqrt(2 + sqrt(2 + sqrt(2))) + +def test_issue_12420(): + assert sqrtdenest((3 - sqrt(2)*sqrt(4 + 3*I) + 3*I)/2) == I + e = 3 - sqrt(2)*sqrt(4 + I) + 3*I + assert sqrtdenest(e) == e + +def test_sqrt_ratcomb(): + assert sqrtdenest(sqrt(1 + r3) + sqrt(3 + 3*r3) - sqrt(10 + 6*r3)) == 0 + +def test_issue_18041(): + e = -sqrt(-2 + 2*sqrt(3)*I) + assert sqrtdenest(e) == -1 - sqrt(3)*I + +def test_issue_19914(): + a = Integer(-8) + b = Integer(-1) + r = Integer(63) + d2 = a*a - b*b*r + + assert _sqrt_numeric_denest(a, b, r, d2) == \ + sqrt(14)*I/2 + 3*sqrt(2)*I/2 + assert sqrtdenest(sqrt(-8-sqrt(63))) == sqrt(14)*I/2 + 3*sqrt(2)*I/2 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_trigsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_trigsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..ea091ec8a6c7d654405968e3d035c2bbe02ccdf7 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/tests/test_trigsimp.py @@ -0,0 +1,520 @@ +from itertools import product +from sympy.core.function import (Subs, count_ops, diff, expand) +from sympy.core.numbers import (E, I, Rational, pi) +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.hyperbolic import (cosh, coth, sinh, tanh) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (cos, cot, sin, tan) +from sympy.functions.elementary.trigonometric import (acos, asin, atan2) +from sympy.functions.elementary.trigonometric import (asec, acsc) +from sympy.functions.elementary.trigonometric import (acot, atan) +from sympy.integrals.integrals import integrate +from sympy.matrices.dense import Matrix +from sympy.simplify.simplify import simplify +from sympy.simplify.trigsimp import (exptrigsimp, trigsimp) + +from sympy.testing.pytest import XFAIL + +from sympy.abc import x, y + + + +def test_trigsimp1(): + x, y = symbols('x,y') + + assert trigsimp(1 - sin(x)**2) == cos(x)**2 + assert trigsimp(1 - cos(x)**2) == sin(x)**2 + assert trigsimp(sin(x)**2 + cos(x)**2) == 1 + assert trigsimp(1 + tan(x)**2) == 1/cos(x)**2 + assert trigsimp(1/cos(x)**2 - 1) == tan(x)**2 + assert trigsimp(1/cos(x)**2 - tan(x)**2) == 1 + assert trigsimp(1 + cot(x)**2) == 1/sin(x)**2 + assert trigsimp(1/sin(x)**2 - 1) == 1/tan(x)**2 + assert trigsimp(1/sin(x)**2 - cot(x)**2) == 1 + + assert trigsimp(5*cos(x)**2 + 5*sin(x)**2) == 5 + assert trigsimp(5*cos(x/2)**2 + 2*sin(x/2)**2) == 3*cos(x)/2 + Rational(7, 2) + + assert trigsimp(sin(x)/cos(x)) == tan(x) + assert trigsimp(2*tan(x)*cos(x)) == 2*sin(x) + assert trigsimp(cot(x)**3*sin(x)**3) == cos(x)**3 + assert trigsimp(y*tan(x)**2/sin(x)**2) == y/cos(x)**2 + assert trigsimp(cot(x)/cos(x)) == 1/sin(x) + + assert trigsimp(sin(x + y) + sin(x - y)) == 2*sin(x)*cos(y) + assert trigsimp(sin(x + y) - sin(x - y)) == 2*sin(y)*cos(x) + assert trigsimp(cos(x + y) + cos(x - y)) == 2*cos(x)*cos(y) + assert trigsimp(cos(x + y) - cos(x - y)) == -2*sin(x)*sin(y) + assert trigsimp(tan(x + y) - tan(x)/(1 - tan(x)*tan(y))) == \ + sin(y)/(-sin(y)*tan(x) + cos(y)) # -tan(y)/(tan(x)*tan(y) - 1) + + assert trigsimp(sinh(x + y) + sinh(x - y)) == 2*sinh(x)*cosh(y) + assert trigsimp(sinh(x + y) - sinh(x - y)) == 2*sinh(y)*cosh(x) + assert trigsimp(cosh(x + y) + cosh(x - y)) == 2*cosh(x)*cosh(y) + assert trigsimp(cosh(x + y) - cosh(x - y)) == 2*sinh(x)*sinh(y) + assert trigsimp(tanh(x + y) - tanh(x)/(1 + tanh(x)*tanh(y))) == \ + sinh(y)/(sinh(y)*tanh(x) + cosh(y)) + + assert trigsimp(cos(0.12345)**2 + sin(0.12345)**2) == 1.0 + e = 2*sin(x)**2 + 2*cos(x)**2 + assert trigsimp(log(e)) == log(2) + + +def test_trigsimp1a(): + assert trigsimp(sin(2)**2*cos(3)*exp(2)/cos(2)**2) == tan(2)**2*cos(3)*exp(2) + assert trigsimp(tan(2)**2*cos(3)*exp(2)*cos(2)**2) == sin(2)**2*cos(3)*exp(2) + assert trigsimp(cot(2)*cos(3)*exp(2)*sin(2)) == cos(3)*exp(2)*cos(2) + assert trigsimp(tan(2)*cos(3)*exp(2)/sin(2)) == cos(3)*exp(2)/cos(2) + assert trigsimp(cot(2)*cos(3)*exp(2)/cos(2)) == cos(3)*exp(2)/sin(2) + assert trigsimp(cot(2)*cos(3)*exp(2)*tan(2)) == cos(3)*exp(2) + assert trigsimp(sinh(2)*cos(3)*exp(2)/cosh(2)) == tanh(2)*cos(3)*exp(2) + assert trigsimp(tanh(2)*cos(3)*exp(2)*cosh(2)) == sinh(2)*cos(3)*exp(2) + assert trigsimp(coth(2)*cos(3)*exp(2)*sinh(2)) == cosh(2)*cos(3)*exp(2) + assert trigsimp(tanh(2)*cos(3)*exp(2)/sinh(2)) == cos(3)*exp(2)/cosh(2) + assert trigsimp(coth(2)*cos(3)*exp(2)/cosh(2)) == cos(3)*exp(2)/sinh(2) + assert trigsimp(coth(2)*cos(3)*exp(2)*tanh(2)) == cos(3)*exp(2) + + +def test_trigsimp2(): + x, y = symbols('x,y') + assert trigsimp(cos(x)**2*sin(y)**2 + cos(x)**2*cos(y)**2 + sin(x)**2, + recursive=True) == 1 + assert trigsimp(sin(x)**2*sin(y)**2 + sin(x)**2*cos(y)**2 + cos(x)**2, + recursive=True) == 1 + assert trigsimp( + Subs(x, x, sin(y)**2 + cos(y)**2)) == Subs(x, x, 1) + + +def test_issue_4373(): + x = Symbol("x") + assert abs(trigsimp(2.0*sin(x)**2 + 2.0*cos(x)**2) - 2.0) < 1e-10 + + +def test_trigsimp3(): + x, y = symbols('x,y') + assert trigsimp(sin(x)/cos(x)) == tan(x) + assert trigsimp(sin(x)**2/cos(x)**2) == tan(x)**2 + assert trigsimp(sin(x)**3/cos(x)**3) == tan(x)**3 + assert trigsimp(sin(x)**10/cos(x)**10) == tan(x)**10 + + assert trigsimp(cos(x)/sin(x)) == 1/tan(x) + assert trigsimp(cos(x)**2/sin(x)**2) == 1/tan(x)**2 + assert trigsimp(cos(x)**10/sin(x)**10) == 1/tan(x)**10 + + assert trigsimp(tan(x)) == trigsimp(sin(x)/cos(x)) + + +def test_issue_4661(): + a, x, y = symbols('a x y') + eq = -4*sin(x)**4 + 4*cos(x)**4 - 8*cos(x)**2 + assert trigsimp(eq) == -4 + n = sin(x)**6 + 4*sin(x)**4*cos(x)**2 + 5*sin(x)**2*cos(x)**4 + 2*cos(x)**6 + d = -sin(x)**2 - 2*cos(x)**2 + assert simplify(n/d) == -1 + assert trigsimp(-2*cos(x)**2 + cos(x)**4 - sin(x)**4) == -1 + eq = (- sin(x)**3/4)*cos(x) + (cos(x)**3/4)*sin(x) - sin(2*x)*cos(2*x)/8 + assert trigsimp(eq) == 0 + + +def test_issue_4494(): + a, b = symbols('a b') + eq = sin(a)**2*sin(b)**2 + cos(a)**2*cos(b)**2*tan(a)**2 + cos(a)**2 + assert trigsimp(eq) == 1 + + +def test_issue_5948(): + a, x, y = symbols('a x y') + assert trigsimp(diff(integrate(cos(x)/sin(x)**7, x), x)) == \ + cos(x)/sin(x)**7 + + +def test_issue_4775(): + a, x, y = symbols('a x y') + assert trigsimp(sin(x)*cos(y)+cos(x)*sin(y)) == sin(x + y) + assert trigsimp(sin(x)*cos(y)+cos(x)*sin(y)+3) == sin(x + y) + 3 + + +def test_issue_4280(): + a, x, y = symbols('a x y') + assert trigsimp(cos(x)**2 + cos(y)**2*sin(x)**2 + sin(y)**2*sin(x)**2) == 1 + assert trigsimp(a**2*sin(x)**2 + a**2*cos(y)**2*cos(x)**2 + a**2*cos(x)**2*sin(y)**2) == a**2 + assert trigsimp(a**2*cos(y)**2*sin(x)**2 + a**2*sin(y)**2*sin(x)**2) == a**2*sin(x)**2 + + +def test_issue_3210(): + eqs = (sin(2)*cos(3) + sin(3)*cos(2), + -sin(2)*sin(3) + cos(2)*cos(3), + sin(2)*cos(3) - sin(3)*cos(2), + sin(2)*sin(3) + cos(2)*cos(3), + sin(2)*sin(3) + cos(2)*cos(3) + cos(2), + sinh(2)*cosh(3) + sinh(3)*cosh(2), + sinh(2)*sinh(3) + cosh(2)*cosh(3), + ) + assert [trigsimp(e) for e in eqs] == [ + sin(5), + cos(5), + -sin(1), + cos(1), + cos(1) + cos(2), + sinh(5), + cosh(5), + ] + + +def test_trigsimp_issues(): + a, x, y = symbols('a x y') + + # issue 4625 - factor_terms works, too + assert trigsimp(sin(x)**3 + cos(x)**2*sin(x)) == sin(x) + + # issue 5948 + assert trigsimp(diff(integrate(cos(x)/sin(x)**3, x), x)) == \ + cos(x)/sin(x)**3 + assert trigsimp(diff(integrate(sin(x)/cos(x)**3, x), x)) == \ + sin(x)/cos(x)**3 + + # check integer exponents + e = sin(x)**y/cos(x)**y + assert trigsimp(e) == e + assert trigsimp(e.subs(y, 2)) == tan(x)**2 + assert trigsimp(e.subs(x, 1)) == tan(1)**y + + # check for multiple patterns + assert (cos(x)**2/sin(x)**2*cos(y)**2/sin(y)**2).trigsimp() == \ + 1/tan(x)**2/tan(y)**2 + assert trigsimp(cos(x)/sin(x)*cos(x+y)/sin(x+y)) == \ + 1/(tan(x)*tan(x + y)) + + eq = cos(2)*(cos(3) + 1)**2/(cos(3) - 1)**2 + assert trigsimp(eq) == eq.factor() # factor makes denom (-1 + cos(3))**2 + assert trigsimp(cos(2)*(cos(3) + 1)**2*(cos(3) - 1)**2) == \ + cos(2)*sin(3)**4 + + # issue 6789; this generates an expression that formerly caused + # trigsimp to hang + assert cot(x).equals(tan(x)) is False + + # nan or the unchanged expression is ok, but not sin(1) + z = cos(x)**2 + sin(x)**2 - 1 + z1 = tan(x)**2 - 1/cot(x)**2 + n = (1 + z1/z) + assert trigsimp(sin(n)) != sin(1) + eq = x*(n - 1) - x*n + assert trigsimp(eq) is S.NaN + assert trigsimp(eq, recursive=True) is S.NaN + assert trigsimp(1).is_Integer + + assert trigsimp(-sin(x)**4 - 2*sin(x)**2*cos(x)**2 - cos(x)**4) == -1 + + +def test_trigsimp_issue_2515(): + x = Symbol('x') + assert trigsimp(x*cos(x)*tan(x)) == x*sin(x) + assert trigsimp(-sin(x) + cos(x)*tan(x)) == 0 + + +def test_trigsimp_issue_3826(): + assert trigsimp(tan(2*x).expand(trig=True)) == tan(2*x) + + +def test_trigsimp_issue_4032(): + n = Symbol('n', integer=True, positive=True) + assert trigsimp(2**(n/2)*cos(pi*n/4)/2 + 2**(n - 1)/2) == \ + 2**(n/2)*cos(pi*n/4)/2 + 2**n/4 + + +def test_trigsimp_issue_7761(): + assert trigsimp(cosh(pi/4)) == cosh(pi/4) + + +def test_trigsimp_noncommutative(): + x, y = symbols('x,y') + A, B = symbols('A,B', commutative=False) + + assert trigsimp(A - A*sin(x)**2) == A*cos(x)**2 + assert trigsimp(A - A*cos(x)**2) == A*sin(x)**2 + assert trigsimp(A*sin(x)**2 + A*cos(x)**2) == A + assert trigsimp(A + A*tan(x)**2) == A/cos(x)**2 + assert trigsimp(A/cos(x)**2 - A) == A*tan(x)**2 + assert trigsimp(A/cos(x)**2 - A*tan(x)**2) == A + assert trigsimp(A + A*cot(x)**2) == A/sin(x)**2 + assert trigsimp(A/sin(x)**2 - A) == A/tan(x)**2 + assert trigsimp(A/sin(x)**2 - A*cot(x)**2) == A + + assert trigsimp(y*A*cos(x)**2 + y*A*sin(x)**2) == y*A + + assert trigsimp(A*sin(x)/cos(x)) == A*tan(x) + assert trigsimp(A*tan(x)*cos(x)) == A*sin(x) + assert trigsimp(A*cot(x)**3*sin(x)**3) == A*cos(x)**3 + assert trigsimp(y*A*tan(x)**2/sin(x)**2) == y*A/cos(x)**2 + assert trigsimp(A*cot(x)/cos(x)) == A/sin(x) + + assert trigsimp(A*sin(x + y) + A*sin(x - y)) == 2*A*sin(x)*cos(y) + assert trigsimp(A*sin(x + y) - A*sin(x - y)) == 2*A*sin(y)*cos(x) + assert trigsimp(A*cos(x + y) + A*cos(x - y)) == 2*A*cos(x)*cos(y) + assert trigsimp(A*cos(x + y) - A*cos(x - y)) == -2*A*sin(x)*sin(y) + + assert trigsimp(A*sinh(x + y) + A*sinh(x - y)) == 2*A*sinh(x)*cosh(y) + assert trigsimp(A*sinh(x + y) - A*sinh(x - y)) == 2*A*sinh(y)*cosh(x) + assert trigsimp(A*cosh(x + y) + A*cosh(x - y)) == 2*A*cosh(x)*cosh(y) + assert trigsimp(A*cosh(x + y) - A*cosh(x - y)) == 2*A*sinh(x)*sinh(y) + + assert trigsimp(A*cos(0.12345)**2 + A*sin(0.12345)**2) == 1.0*A + + +def test_hyperbolic_simp(): + x, y = symbols('x,y') + + assert trigsimp(sinh(x)**2 + 1) == cosh(x)**2 + assert trigsimp(cosh(x)**2 - 1) == sinh(x)**2 + assert trigsimp(cosh(x)**2 - sinh(x)**2) == 1 + assert trigsimp(1 - tanh(x)**2) == 1/cosh(x)**2 + assert trigsimp(1 - 1/cosh(x)**2) == tanh(x)**2 + assert trigsimp(tanh(x)**2 + 1/cosh(x)**2) == 1 + assert trigsimp(coth(x)**2 - 1) == 1/sinh(x)**2 + assert trigsimp(1/sinh(x)**2 + 1) == 1/tanh(x)**2 + assert trigsimp(coth(x)**2 - 1/sinh(x)**2) == 1 + + assert trigsimp(5*cosh(x)**2 - 5*sinh(x)**2) == 5 + assert trigsimp(5*cosh(x/2)**2 - 2*sinh(x/2)**2) == 3*cosh(x)/2 + Rational(7, 2) + + assert trigsimp(sinh(x)/cosh(x)) == tanh(x) + assert trigsimp(tanh(x)) == trigsimp(sinh(x)/cosh(x)) + assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x) + assert trigsimp(2*tanh(x)*cosh(x)) == 2*sinh(x) + assert trigsimp(coth(x)**3*sinh(x)**3) == cosh(x)**3 + assert trigsimp(y*tanh(x)**2/sinh(x)**2) == y/cosh(x)**2 + assert trigsimp(coth(x)/cosh(x)) == 1/sinh(x) + + for a in (pi/6*I, pi/4*I, pi/3*I): + assert trigsimp(sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x + a) + assert trigsimp(-sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x - a) + + e = 2*cosh(x)**2 - 2*sinh(x)**2 + assert trigsimp(log(e)) == log(2) + + # issue 19535: + assert trigsimp(sqrt(cosh(x)**2 - 1)) == sqrt(sinh(x)**2) + + assert trigsimp(cosh(x)**2*cosh(y)**2 - cosh(x)**2*sinh(y)**2 - sinh(x)**2, + recursive=True) == 1 + assert trigsimp(sinh(x)**2*sinh(y)**2 - sinh(x)**2*cosh(y)**2 + cosh(x)**2, + recursive=True) == 1 + + assert abs(trigsimp(2.0*cosh(x)**2 - 2.0*sinh(x)**2) - 2.0) < 1e-10 + + assert trigsimp(sinh(x)**2/cosh(x)**2) == tanh(x)**2 + assert trigsimp(sinh(x)**3/cosh(x)**3) == tanh(x)**3 + assert trigsimp(sinh(x)**10/cosh(x)**10) == tanh(x)**10 + assert trigsimp(cosh(x)**3/sinh(x)**3) == 1/tanh(x)**3 + + assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x) + assert trigsimp(cosh(x)**2/sinh(x)**2) == 1/tanh(x)**2 + assert trigsimp(cosh(x)**10/sinh(x)**10) == 1/tanh(x)**10 + + assert trigsimp(x*cosh(x)*tanh(x)) == x*sinh(x) + assert trigsimp(-sinh(x) + cosh(x)*tanh(x)) == 0 + + assert tan(x) != 1/cot(x) # cot doesn't auto-simplify + + assert trigsimp(tan(x) - 1/cot(x)) == 0 + assert trigsimp(3*tanh(x)**7 - 2/coth(x)**7) == tanh(x)**7 + + +def test_trigsimp_groebner(): + from sympy.simplify.trigsimp import trigsimp_groebner + + c = cos(x) + s = sin(x) + ex = (4*s*c + 12*s + 5*c**3 + 21*c**2 + 23*c + 15)/( + -s*c**2 + 2*s*c + 15*s + 7*c**3 + 31*c**2 + 37*c + 21) + resnum = (5*s - 5*c + 1) + resdenom = (8*s - 6*c) + results = [resnum/resdenom, (-resnum)/(-resdenom)] + assert trigsimp_groebner(ex) in results + assert trigsimp_groebner(s/c, hints=[tan]) == tan(x) + assert trigsimp_groebner(c*s) == c*s + assert trigsimp((-s + 1)/c + c/(-s + 1), + method='groebner') == 2/c + assert trigsimp((-s + 1)/c + c/(-s + 1), + method='groebner', polynomial=True) == 2/c + + # Test quick=False works + assert trigsimp_groebner(ex, hints=[2]) in results + assert trigsimp_groebner(ex, hints=[int(2)]) in results + + # test "I" + assert trigsimp_groebner(sin(I*x)/cos(I*x), hints=[tanh]) == I*tanh(x) + + # test hyperbolic / sums + assert trigsimp_groebner((tanh(x)+tanh(y))/(1+tanh(x)*tanh(y)), + hints=[(tanh, x, y)]) == tanh(x + y) + + +def test_issue_2827_trigsimp_methods(): + measure1 = lambda expr: len(str(expr)) + measure2 = lambda expr: -count_ops(expr) + # Return the most complicated result + expr = (x + 1)/(x + sin(x)**2 + cos(x)**2) + ans = Matrix([1]) + M = Matrix([expr]) + assert trigsimp(M, method='fu', measure=measure1) == ans + assert trigsimp(M, method='fu', measure=measure2) != ans + # all methods should work with Basic expressions even if they + # aren't Expr + M = Matrix.eye(1) + assert all(trigsimp(M, method=m) == M for m in + 'fu matching groebner old'.split()) + # watch for E in exptrigsimp, not only exp() + eq = 1/sqrt(E) + E + assert exptrigsimp(eq) == eq + +def test_issue_15129_trigsimp_methods(): + t1 = Matrix([sin(Rational(1, 50)), cos(Rational(1, 50)), 0]) + t2 = Matrix([sin(Rational(1, 25)), cos(Rational(1, 25)), 0]) + t3 = Matrix([cos(Rational(1, 25)), sin(Rational(1, 25)), 0]) + r1 = t1.dot(t2) + r2 = t1.dot(t3) + assert trigsimp(r1) == cos(Rational(1, 50)) + assert trigsimp(r2) == sin(Rational(3, 50)) + +def test_exptrigsimp(): + def valid(a, b): + from sympy.core.random import verify_numerically as tn + if not (tn(a, b) and a == b): + return False + return True + + assert exptrigsimp(exp(x) + exp(-x)) == 2*cosh(x) + assert exptrigsimp(exp(x) - exp(-x)) == 2*sinh(x) + assert exptrigsimp((2*exp(x)-2*exp(-x))/(exp(x)+exp(-x))) == 2*tanh(x) + assert exptrigsimp((2*exp(2*x)-2)/(exp(2*x)+1)) == 2*tanh(x) + e = [cos(x) + I*sin(x), cos(x) - I*sin(x), + cosh(x) - sinh(x), cosh(x) + sinh(x)] + ok = [exp(I*x), exp(-I*x), exp(-x), exp(x)] + assert all(valid(i, j) for i, j in zip( + [exptrigsimp(ei) for ei in e], ok)) + + ue = [cos(x) + sin(x), cos(x) - sin(x), + cosh(x) + I*sinh(x), cosh(x) - I*sinh(x)] + assert [exptrigsimp(ei) == ei for ei in ue] + + res = [] + ok = [y*tanh(1), 1/(y*tanh(1)), I*y*tan(1), -I/(y*tan(1)), + y*tanh(x), 1/(y*tanh(x)), I*y*tan(x), -I/(y*tan(x)), + y*tanh(1 + I), 1/(y*tanh(1 + I))] + for a in (1, I, x, I*x, 1 + I): + w = exp(a) + eq = y*(w - 1/w)/(w + 1/w) + res.append(simplify(eq)) + res.append(simplify(1/eq)) + assert all(valid(i, j) for i, j in zip(res, ok)) + + for a in range(1, 3): + w = exp(a) + e = w + 1/w + s = simplify(e) + assert s == exptrigsimp(e) + assert valid(s, 2*cosh(a)) + e = w - 1/w + s = simplify(e) + assert s == exptrigsimp(e) + assert valid(s, 2*sinh(a)) + +def test_exptrigsimp_noncommutative(): + a,b = symbols('a b', commutative=False) + x = Symbol('x', commutative=True) + assert exp(a + x) == exptrigsimp(exp(a)*exp(x)) + p = exp(a)*exp(b) - exp(b)*exp(a) + assert p == exptrigsimp(p) != 0 + +def test_powsimp_on_numbers(): + assert 2**(Rational(1, 3) - 2) == 2**Rational(1, 3)/4 + + +@XFAIL +def test_issue_6811_fail(): + # from doc/src/modules/physics/mechanics/examples.rst, the current `eq` + # at Line 576 (in different variables) was formerly the equivalent and + # shorter expression given below...it would be nice to get the short one + # back again + xp, y, x, z = symbols('xp, y, x, z') + eq = 4*(-19*sin(x)*y + 5*sin(3*x)*y + 15*cos(2*x)*z - 21*z)*xp/(9*cos(x) - 5*cos(3*x)) + assert trigsimp(eq) == -2*(2*cos(x)*tan(x)*y + 3*z)*xp/cos(x) + + +def test_Piecewise(): + e1 = x*(x + y) - y*(x + y) + e2 = sin(x)**2 + cos(x)**2 + e3 = expand((x + y)*y/x) + # s1 = simplify(e1) + s2 = simplify(e2) + # s3 = simplify(e3) + + # trigsimp tries not to touch non-trig containing args + assert trigsimp(Piecewise((e1, e3 < e2), (e3, True))) == \ + Piecewise((e1, e3 < s2), (e3, True)) + + +def test_issue_21594(): + assert simplify(exp(Rational(1,2)) + exp(Rational(-1,2))) == cosh(S.Half)*2 + + +def test_trigsimp_old(): + x, y = symbols('x,y') + + assert trigsimp(1 - sin(x)**2, old=True) == cos(x)**2 + assert trigsimp(1 - cos(x)**2, old=True) == sin(x)**2 + assert trigsimp(sin(x)**2 + cos(x)**2, old=True) == 1 + assert trigsimp(1 + tan(x)**2, old=True) == 1/cos(x)**2 + assert trigsimp(1/cos(x)**2 - 1, old=True) == tan(x)**2 + assert trigsimp(1/cos(x)**2 - tan(x)**2, old=True) == 1 + assert trigsimp(1 + cot(x)**2, old=True) == 1/sin(x)**2 + assert trigsimp(1/sin(x)**2 - cot(x)**2, old=True) == 1 + + assert trigsimp(5*cos(x)**2 + 5*sin(x)**2, old=True) == 5 + + assert trigsimp(sin(x)/cos(x), old=True) == tan(x) + assert trigsimp(2*tan(x)*cos(x), old=True) == 2*sin(x) + assert trigsimp(cot(x)**3*sin(x)**3, old=True) == cos(x)**3 + assert trigsimp(y*tan(x)**2/sin(x)**2, old=True) == y/cos(x)**2 + assert trigsimp(cot(x)/cos(x), old=True) == 1/sin(x) + + assert trigsimp(sin(x + y) + sin(x - y), old=True) == 2*sin(x)*cos(y) + assert trigsimp(sin(x + y) - sin(x - y), old=True) == 2*sin(y)*cos(x) + assert trigsimp(cos(x + y) + cos(x - y), old=True) == 2*cos(x)*cos(y) + assert trigsimp(cos(x + y) - cos(x - y), old=True) == -2*sin(x)*sin(y) + + assert trigsimp(sinh(x + y) + sinh(x - y), old=True) == 2*sinh(x)*cosh(y) + assert trigsimp(sinh(x + y) - sinh(x - y), old=True) == 2*sinh(y)*cosh(x) + assert trigsimp(cosh(x + y) + cosh(x - y), old=True) == 2*cosh(x)*cosh(y) + assert trigsimp(cosh(x + y) - cosh(x - y), old=True) == 2*sinh(x)*sinh(y) + + assert trigsimp(cos(0.12345)**2 + sin(0.12345)**2, old=True) == 1.0 + + assert trigsimp(sin(x)/cos(x), old=True, method='combined') == tan(x) + assert trigsimp(sin(x)/cos(x), old=True, method='groebner') == sin(x)/cos(x) + assert trigsimp(sin(x)/cos(x), old=True, method='groebner', hints=[tan]) == tan(x) + + assert trigsimp(1-sin(sin(x)**2+cos(x)**2)**2, old=True, deep=True) == cos(1)**2 + + +def test_trigsimp_inverse(): + alpha = symbols('alpha') + s, c = sin(alpha), cos(alpha) + + for finv in [asin, acos, asec, acsc, atan, acot]: + f = finv.inverse(None) + assert alpha == trigsimp(finv(f(alpha)), inverse=True) + + # test atan2(cos, sin), atan2(sin, cos), etc... + for a, b in [[c, s], [s, c]]: + for i, j in product([-1, 1], repeat=2): + angle = atan2(i*b, j*a) + angle_inverted = trigsimp(angle, inverse=True) + assert angle_inverted != angle # assures simplification happened + assert sin(angle_inverted) == trigsimp(sin(angle)) + assert cos(angle_inverted) == trigsimp(cos(angle)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/traversaltools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/traversaltools.py new file mode 100644 index 0000000000000000000000000000000000000000..75b0bd0d8fd198cb12640ab8a0fe63a23c81ed8f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/traversaltools.py @@ -0,0 +1,15 @@ +from sympy.core.traversal import use as _use +from sympy.utilities.decorator import deprecated + +use = deprecated( + """ + Using use from the sympy.simplify.traversaltools submodule is + deprecated. + + Instead, use use from the top-level sympy namespace, like + + sympy.use + """, + deprecated_since_version="1.10", + active_deprecations_target="deprecated-traversal-functions-moved" +)(_use) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/trigsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/trigsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..fe5be1444a4625e4b63b339877e441d12cfbe8de --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/simplify/trigsimp.py @@ -0,0 +1,1252 @@ +from collections import defaultdict +from functools import reduce + +from sympy.core import (sympify, Basic, S, Expr, factor_terms, + Mul, Add, bottom_up) +from sympy.core.cache import cacheit +from sympy.core.function import (count_ops, _mexpand, FunctionClass, expand, + expand_mul, _coeff_isneg, Derivative) +from sympy.core.numbers import I, Integer +from sympy.core.intfunc import igcd +from sympy.core.sorting import _nodes +from sympy.core.symbol import Dummy, symbols, Wild +from sympy.external.gmpy import SYMPY_INTS +from sympy.functions import sin, cos, exp, cosh, tanh, sinh, tan, cot, coth +from sympy.functions import atan2 +from sympy.functions.elementary.hyperbolic import HyperbolicFunction +from sympy.functions.elementary.trigonometric import TrigonometricFunction +from sympy.polys import Poly, factor, cancel, parallel_poly_from_expr +from sympy.polys.domains import ZZ +from sympy.polys.polyerrors import PolificationFailed +from sympy.polys.polytools import groebner +from sympy.simplify.cse_main import cse +from sympy.strategies.core import identity +from sympy.strategies.tree import greedy +from sympy.utilities.iterables import iterable +from sympy.utilities.misc import debug + +def trigsimp_groebner(expr, hints=[], quick=False, order="grlex", + polynomial=False): + """ + Simplify trigonometric expressions using a groebner basis algorithm. + + Explanation + =========== + + This routine takes a fraction involving trigonometric or hyperbolic + expressions, and tries to simplify it. The primary metric is the + total degree. Some attempts are made to choose the simplest possible + expression of the minimal degree, but this is non-rigorous, and also + very slow (see the ``quick=True`` option). + + If ``polynomial`` is set to True, instead of simplifying numerator and + denominator together, this function just brings numerator and denominator + into a canonical form. This is much faster, but has potentially worse + results. However, if the input is a polynomial, then the result is + guaranteed to be an equivalent polynomial of minimal degree. + + The most important option is hints. Its entries can be any of the + following: + + - a natural number + - a function + - an iterable of the form (func, var1, var2, ...) + - anything else, interpreted as a generator + + A number is used to indicate that the search space should be increased. + A function is used to indicate that said function is likely to occur in a + simplified expression. + An iterable is used indicate that func(var1 + var2 + ...) is likely to + occur in a simplified . + An additional generator also indicates that it is likely to occur. + (See examples below). + + This routine carries out various computationally intensive algorithms. + The option ``quick=True`` can be used to suppress one particularly slow + step (at the expense of potentially more complicated results, but never at + the expense of increased total degree). + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy import sin, tan, cos, sinh, cosh, tanh + >>> from sympy.simplify.trigsimp import trigsimp_groebner + + Suppose you want to simplify ``sin(x)*cos(x)``. Naively, nothing happens: + + >>> ex = sin(x)*cos(x) + >>> trigsimp_groebner(ex) + sin(x)*cos(x) + + This is because ``trigsimp_groebner`` only looks for a simplification + involving just ``sin(x)`` and ``cos(x)``. You can tell it to also try + ``2*x`` by passing ``hints=[2]``: + + >>> trigsimp_groebner(ex, hints=[2]) + sin(2*x)/2 + >>> trigsimp_groebner(sin(x)**2 - cos(x)**2, hints=[2]) + -cos(2*x) + + Increasing the search space this way can quickly become expensive. A much + faster way is to give a specific expression that is likely to occur: + + >>> trigsimp_groebner(ex, hints=[sin(2*x)]) + sin(2*x)/2 + + Hyperbolic expressions are similarly supported: + + >>> trigsimp_groebner(sinh(2*x)/sinh(x)) + 2*cosh(x) + + Note how no hints had to be passed, since the expression already involved + ``2*x``. + + The tangent function is also supported. You can either pass ``tan`` in the + hints, to indicate that tan should be tried whenever cosine or sine are, + or you can pass a specific generator: + + >>> trigsimp_groebner(sin(x)/cos(x), hints=[tan]) + tan(x) + >>> trigsimp_groebner(sinh(x)/cosh(x), hints=[tanh(x)]) + tanh(x) + + Finally, you can use the iterable form to suggest that angle sum formulae + should be tried: + + >>> ex = (tan(x) + tan(y))/(1 - tan(x)*tan(y)) + >>> trigsimp_groebner(ex, hints=[(tan, x, y)]) + tan(x + y) + """ + # TODO + # - preprocess by replacing everything by funcs we can handle + # - optionally use cot instead of tan + # - more intelligent hinting. + # For example, if the ideal is small, and we have sin(x), sin(y), + # add sin(x + y) automatically... ? + # - algebraic numbers ... + # - expressions of lowest degree are not distinguished properly + # e.g. 1 - sin(x)**2 + # - we could try to order the generators intelligently, so as to influence + # which monomials appear in the quotient basis + + # THEORY + # ------ + # Ratsimpmodprime above can be used to "simplify" a rational function + # modulo a prime ideal. "Simplify" mainly means finding an equivalent + # expression of lower total degree. + # + # We intend to use this to simplify trigonometric functions. To do that, + # we need to decide (a) which ring to use, and (b) modulo which ideal to + # simplify. In practice, (a) means settling on a list of "generators" + # a, b, c, ..., such that the fraction we want to simplify is a rational + # function in a, b, c, ..., with coefficients in ZZ (integers). + # (2) means that we have to decide what relations to impose on the + # generators. There are two practical problems: + # (1) The ideal has to be *prime* (a technical term). + # (2) The relations have to be polynomials in the generators. + # + # We typically have two kinds of generators: + # - trigonometric expressions, like sin(x), cos(5*x), etc + # - "everything else", like gamma(x), pi, etc. + # + # Since this function is trigsimp, we will concentrate on what to do with + # trigonometric expressions. We can also simplify hyperbolic expressions, + # but the extensions should be clear. + # + # One crucial point is that all *other* generators really should behave + # like indeterminates. In particular if (say) "I" is one of them, then + # in fact I**2 + 1 = 0 and we may and will compute non-sensical + # expressions. However, we can work with a dummy and add the relation + # I**2 + 1 = 0 to our ideal, then substitute back in the end. + # + # Now regarding trigonometric generators. We split them into groups, + # according to the argument of the trigonometric functions. We want to + # organise this in such a way that most trigonometric identities apply in + # the same group. For example, given sin(x), cos(2*x) and cos(y), we would + # group as [sin(x), cos(2*x)] and [cos(y)]. + # + # Our prime ideal will be built in three steps: + # (1) For each group, compute a "geometrically prime" ideal of relations. + # Geometrically prime means that it generates a prime ideal in + # CC[gens], not just ZZ[gens]. + # (2) Take the union of all the generators of the ideals for all groups. + # By the geometric primality condition, this is still prime. + # (3) Add further inter-group relations which preserve primality. + # + # Step (1) works as follows. We will isolate common factors in the + # argument, so that all our generators are of the form sin(n*x), cos(n*x) + # or tan(n*x), with n an integer. Suppose first there are no tan terms. + # The ideal [sin(x)**2 + cos(x)**2 - 1] is geometrically prime, since + # X**2 + Y**2 - 1 is irreducible over CC. + # Now, if we have a generator sin(n*x), than we can, using trig identities, + # express sin(n*x) as a polynomial in sin(x) and cos(x). We can add this + # relation to the ideal, preserving geometric primality, since the quotient + # ring is unchanged. + # Thus we have treated all sin and cos terms. + # For tan(n*x), we add a relation tan(n*x)*cos(n*x) - sin(n*x) = 0. + # (This requires of course that we already have relations for cos(n*x) and + # sin(n*x).) It is not obvious, but it seems that this preserves geometric + # primality. + # XXX A real proof would be nice. HELP! + # Sketch that is a prime ideal of + # CC[S, C, T]: + # - it suffices to show that the projective closure in CP**3 is + # irreducible + # - using the half-angle substitutions, we can express sin(x), tan(x), + # cos(x) as rational functions in tan(x/2) + # - from this, we get a rational map from CP**1 to our curve + # - this is a morphism, hence the curve is prime + # + # Step (2) is trivial. + # + # Step (3) works by adding selected relations of the form + # sin(x + y) - sin(x)*cos(y) - sin(y)*cos(x), etc. Geometric primality is + # preserved by the same argument as before. + + def parse_hints(hints): + """Split hints into (n, funcs, iterables, gens).""" + n = 1 + funcs, iterables, gens = [], [], [] + for e in hints: + if isinstance(e, (SYMPY_INTS, Integer)): + n = e + elif isinstance(e, FunctionClass): + funcs.append(e) + elif iterable(e): + iterables.append((e[0], e[1:])) + # XXX sin(x+2y)? + # Note: we go through polys so e.g. + # sin(-x) -> -sin(x) -> sin(x) + gens.extend(parallel_poly_from_expr( + [e[0](x) for x in e[1:]] + [e[0](Add(*e[1:]))])[1].gens) + else: + gens.append(e) + return n, funcs, iterables, gens + + def build_ideal(x, terms): + """ + Build generators for our ideal. ``Terms`` is an iterable with elements of + the form (fn, coeff), indicating that we have a generator fn(coeff*x). + + If any of the terms is trigonometric, sin(x) and cos(x) are guaranteed + to appear in terms. Similarly for hyperbolic functions. For tan(n*x), + sin(n*x) and cos(n*x) are guaranteed. + """ + I = [] + y = Dummy('y') + for fn, coeff in terms: + for c, s, t, rel in ( + [cos, sin, tan, cos(x)**2 + sin(x)**2 - 1], + [cosh, sinh, tanh, cosh(x)**2 - sinh(x)**2 - 1]): + if coeff == 1 and fn in [c, s]: + I.append(rel) + elif fn == t: + I.append(t(coeff*x)*c(coeff*x) - s(coeff*x)) + elif fn in [c, s]: + cn = fn(coeff*y).expand(trig=True).subs(y, x) + I.append(fn(coeff*x) - cn) + return list(set(I)) + + def analyse_gens(gens, hints): + """ + Analyse the generators ``gens``, using the hints ``hints``. + + The meaning of ``hints`` is described in the main docstring. + Return a new list of generators, and also the ideal we should + work with. + """ + # First parse the hints + n, funcs, iterables, extragens = parse_hints(hints) + debug('n=%s funcs: %s iterables: %s extragens: %s', + (funcs, iterables, extragens)) + + # We just add the extragens to gens and analyse them as before + gens = list(gens) + gens.extend(extragens) + + # remove duplicates + funcs = list(set(funcs)) + iterables = list(set(iterables)) + gens = list(set(gens)) + + # all the functions we can do anything with + allfuncs = {sin, cos, tan, sinh, cosh, tanh} + # sin(3*x) -> ((3, x), sin) + trigterms = [(g.args[0].as_coeff_mul(), g.func) for g in gens + if g.func in allfuncs] + # Our list of new generators - start with anything that we cannot + # work with (i.e. is not a trigonometric term) + freegens = [g for g in gens if g.func not in allfuncs] + newgens = [] + trigdict = {} + for (coeff, var), fn in trigterms: + trigdict.setdefault(var, []).append((coeff, fn)) + res = [] # the ideal + + for key, val in trigdict.items(): + # We have now assembeled a dictionary. Its keys are common + # arguments in trigonometric expressions, and values are lists of + # pairs (fn, coeff). x0, (fn, coeff) in trigdict means that we + # need to deal with fn(coeff*x0). We take the rational gcd of the + # coeffs, call it ``gcd``. We then use x = x0/gcd as "base symbol", + # all other arguments are integral multiples thereof. + # We will build an ideal which works with sin(x), cos(x). + # If hint tan is provided, also work with tan(x). Moreover, if + # n > 1, also work with sin(k*x) for k <= n, and similarly for cos + # (and tan if the hint is provided). Finally, any generators which + # the ideal does not work with but we need to accommodate (either + # because it was in expr or because it was provided as a hint) + # we also build into the ideal. + # This selection process is expressed in the list ``terms``. + # build_ideal then generates the actual relations in our ideal, + # from this list. + fns = [x[1] for x in val] + val = [x[0] for x in val] + gcd = reduce(igcd, val) + terms = [(fn, v/gcd) for (fn, v) in zip(fns, val)] + fs = set(funcs + fns) + for c, s, t in ([cos, sin, tan], [cosh, sinh, tanh]): + if any(x in fs for x in (c, s, t)): + fs.add(c) + fs.add(s) + for fn in fs: + terms.extend((fn, k) for k in range(1, n + 1)) + extra = [] + for fn, v in terms: + if fn == tan: + extra.append((sin, v)) + extra.append((cos, v)) + if fn in [sin, cos] and tan in fs: + extra.append((tan, v)) + if fn == tanh: + extra.append((sinh, v)) + extra.append((cosh, v)) + if fn in [sinh, cosh] and tanh in fs: + extra.append((tanh, v)) + terms.extend(extra) + x = gcd*Mul(*key) + r = build_ideal(x, terms) + res.extend(r) + newgens.extend({fn(v*x) for fn, v in terms}) + + # Add generators for compound expressions from iterables + for fn, args in iterables: + if fn == tan: + # Tan expressions are recovered from sin and cos. + iterables.extend([(sin, args), (cos, args)]) + elif fn == tanh: + # Tanh expressions are recovered from sihn and cosh. + iterables.extend([(sinh, args), (cosh, args)]) + else: + dummys = symbols('d:%i' % len(args), cls=Dummy) + expr = fn( Add(*dummys)).expand(trig=True).subs(list(zip(dummys, args))) + res.append(fn(Add(*args)) - expr) + + if myI in gens: + res.append(myI**2 + 1) + freegens.remove(myI) + newgens.append(myI) + + return res, freegens, newgens + + myI = Dummy('I') + expr = expr.subs(S.ImaginaryUnit, myI) + subs = [(myI, S.ImaginaryUnit)] + + num, denom = cancel(expr).as_numer_denom() + try: + (pnum, pdenom), opt = parallel_poly_from_expr([num, denom]) + except PolificationFailed: + return expr + debug('initial gens:', opt.gens) + ideal, freegens, gens = analyse_gens(opt.gens, hints) + debug('ideal:', ideal) + debug('new gens:', gens, " -- len", len(gens)) + debug('free gens:', freegens, " -- len", len(gens)) + # NOTE we force the domain to be ZZ to stop polys from injecting generators + # (which is usually a sign of a bug in the way we build the ideal) + if not gens: + return expr + G = groebner(ideal, order=order, gens=gens, domain=ZZ) + debug('groebner basis:', list(G), " -- len", len(G)) + + # If our fraction is a polynomial in the free generators, simplify all + # coefficients separately: + + from sympy.simplify.ratsimp import ratsimpmodprime + + if freegens and pdenom.has_only_gens(*set(gens).intersection(pdenom.gens)): + num = Poly(num, gens=gens+freegens).eject(*gens) + res = [] + for monom, coeff in num.terms(): + ourgens = set(parallel_poly_from_expr([coeff, denom])[1].gens) + # We compute the transitive closure of all generators that can + # be reached from our generators through relations in the ideal. + changed = True + while changed: + changed = False + for p in ideal: + p = Poly(p) + if not ourgens.issuperset(p.gens) and \ + not p.has_only_gens(*set(p.gens).difference(ourgens)): + changed = True + ourgens.update(p.exclude().gens) + # NOTE preserve order! + realgens = [x for x in gens if x in ourgens] + # The generators of the ideal have now been (implicitly) split + # into two groups: those involving ourgens and those that don't. + # Since we took the transitive closure above, these two groups + # live in subgrings generated by a *disjoint* set of variables. + # Any sensible groebner basis algorithm will preserve this disjoint + # structure (i.e. the elements of the groebner basis can be split + # similarly), and and the two subsets of the groebner basis then + # form groebner bases by themselves. (For the smaller generating + # sets, of course.) + ourG = [g.as_expr() for g in G.polys if + g.has_only_gens(*ourgens.intersection(g.gens))] + res.append(Mul(*[a**b for a, b in zip(freegens, monom)]) * \ + ratsimpmodprime(coeff/denom, ourG, order=order, + gens=realgens, quick=quick, domain=ZZ, + polynomial=polynomial).subs(subs)) + return Add(*res) + # NOTE The following is simpler and has less assumptions on the + # groebner basis algorithm. If the above turns out to be broken, + # use this. + return Add(*[Mul(*[a**b for a, b in zip(freegens, monom)]) * \ + ratsimpmodprime(coeff/denom, list(G), order=order, + gens=gens, quick=quick, domain=ZZ) + for monom, coeff in num.terms()]) + else: + return ratsimpmodprime( + expr, list(G), order=order, gens=freegens+gens, + quick=quick, domain=ZZ, polynomial=polynomial).subs(subs) + + +_trigs = (TrigonometricFunction, HyperbolicFunction) + + +def _trigsimp_inverse(rv): + + def check_args(x, y): + try: + return x.args[0] == y.args[0] + except IndexError: + return False + + def f(rv): + # for simple functions + g = getattr(rv, 'inverse', None) + if (g is not None and isinstance(rv.args[0], g()) and + isinstance(g()(1), TrigonometricFunction)): + return rv.args[0].args[0] + + # for atan2 simplifications, harder because atan2 has 2 args + if isinstance(rv, atan2): + y, x = rv.args + if _coeff_isneg(y): + return -f(atan2(-y, x)) + elif _coeff_isneg(x): + return S.Pi - f(atan2(y, -x)) + + if check_args(x, y): + if isinstance(y, sin) and isinstance(x, cos): + return x.args[0] + if isinstance(y, cos) and isinstance(x, sin): + return S.Pi / 2 - x.args[0] + + return rv + + return bottom_up(rv, f) + + +def trigsimp(expr, inverse=False, **opts): + """Returns a reduced expression by using known trig identities. + + Parameters + ========== + + inverse : bool, optional + If ``inverse=True``, it will be assumed that a composition of inverse + functions, such as sin and asin, can be cancelled in any order. + For example, ``asin(sin(x))`` will yield ``x`` without checking whether + x belongs to the set where this relation is true. The default is False. + Default : True + + method : string, optional + Specifies the method to use. Valid choices are: + + - ``'matching'``, default + - ``'groebner'`` + - ``'combined'`` + - ``'fu'`` + - ``'old'`` + + If ``'matching'``, simplify the expression recursively by targeting + common patterns. If ``'groebner'``, apply an experimental groebner + basis algorithm. In this case further options are forwarded to + ``trigsimp_groebner``, please refer to + its docstring. If ``'combined'``, it first runs the groebner basis + algorithm with small default parameters, then runs the ``'matching'`` + algorithm. If ``'fu'``, run the collection of trigonometric + transformations described by Fu, et al. (see the + :py:func:`~sympy.simplify.fu.fu` docstring). If ``'old'``, the original + SymPy trig simplification function is run. + opts : + Optional keyword arguments passed to the method. See each method's + function docstring for details. + + Examples + ======== + + >>> from sympy import trigsimp, sin, cos, log + >>> from sympy.abc import x + >>> e = 2*sin(x)**2 + 2*cos(x)**2 + >>> trigsimp(e) + 2 + + Simplification occurs wherever trigonometric functions are located. + + >>> trigsimp(log(e)) + log(2) + + Using ``method='groebner'`` (or ``method='combined'``) might lead to + greater simplification. + + The old trigsimp routine can be accessed as with method ``method='old'``. + + >>> from sympy import coth, tanh + >>> t = 3*tanh(x)**7 - 2/coth(x)**7 + >>> trigsimp(t, method='old') == t + True + >>> trigsimp(t) + tanh(x)**7 + + """ + from sympy.simplify.fu import fu + + expr = sympify(expr) + + _eval_trigsimp = getattr(expr, '_eval_trigsimp', None) + if _eval_trigsimp is not None: + return _eval_trigsimp(**opts) + + old = opts.pop('old', False) + if not old: + opts.pop('deep', None) + opts.pop('recursive', None) + method = opts.pop('method', 'matching') + else: + method = 'old' + + def groebnersimp(ex, **opts): + def traverse(e): + if e.is_Atom: + return e + args = [traverse(x) for x in e.args] + if e.is_Function or e.is_Pow: + args = [trigsimp_groebner(x, **opts) for x in args] + return e.func(*args) + new = traverse(ex) + if not isinstance(new, Expr): + return new + return trigsimp_groebner(new, **opts) + + trigsimpfunc = { + 'fu': (lambda x: fu(x, **opts)), + 'matching': (lambda x: futrig(x)), + 'groebner': (lambda x: groebnersimp(x, **opts)), + 'combined': (lambda x: futrig(groebnersimp(x, + polynomial=True, hints=[2, tan]))), + 'old': lambda x: trigsimp_old(x, **opts), + }[method] + + expr_simplified = trigsimpfunc(expr) + if inverse: + expr_simplified = _trigsimp_inverse(expr_simplified) + + return expr_simplified + + +def exptrigsimp(expr): + """ + Simplifies exponential / trigonometric / hyperbolic functions. + + Examples + ======== + + >>> from sympy import exptrigsimp, exp, cosh, sinh + >>> from sympy.abc import z + + >>> exptrigsimp(exp(z) + exp(-z)) + 2*cosh(z) + >>> exptrigsimp(cosh(z) - sinh(z)) + exp(-z) + """ + from sympy.simplify.fu import hyper_as_trig, TR2i + + def exp_trig(e): + # select the better of e, and e rewritten in terms of exp or trig + # functions + choices = [e] + if e.has(*_trigs): + choices.append(e.rewrite(exp)) + choices.append(e.rewrite(cos)) + return min(*choices, key=count_ops) + newexpr = bottom_up(expr, exp_trig) + + def f(rv): + if not rv.is_Mul: + return rv + commutative_part, noncommutative_part = rv.args_cnc() + # Since as_powers_dict loses order information, + # if there is more than one noncommutative factor, + # it should only be used to simplify the commutative part. + if (len(noncommutative_part) > 1): + return f(Mul(*commutative_part))*Mul(*noncommutative_part) + rvd = rv.as_powers_dict() + newd = rvd.copy() + + def signlog(expr, sign=S.One): + if expr is S.Exp1: + return sign, S.One + elif isinstance(expr, exp) or (expr.is_Pow and expr.base == S.Exp1): + return sign, expr.exp + elif sign is S.One: + return signlog(-expr, sign=-S.One) + else: + return None, None + + ee = rvd[S.Exp1] + for k in rvd: + if k.is_Add and len(k.args) == 2: + # k == c*(1 + sign*E**x) + c = k.args[0] + sign, x = signlog(k.args[1]/c) + if not x: + continue + m = rvd[k] + newd[k] -= m + if ee == -x*m/2: + # sinh and cosh + newd[S.Exp1] -= ee + ee = 0 + if sign == 1: + newd[2*c*cosh(x/2)] += m + else: + newd[-2*c*sinh(x/2)] += m + elif newd[1 - sign*S.Exp1**x] == -m: + # tanh + del newd[1 - sign*S.Exp1**x] + if sign == 1: + newd[-c/tanh(x/2)] += m + else: + newd[-c*tanh(x/2)] += m + else: + newd[1 + sign*S.Exp1**x] += m + newd[c] += m + + return Mul(*[k**newd[k] for k in newd]) + newexpr = bottom_up(newexpr, f) + + # sin/cos and sinh/cosh ratios to tan and tanh, respectively + if newexpr.has(HyperbolicFunction): + e, f = hyper_as_trig(newexpr) + newexpr = f(TR2i(e)) + if newexpr.has(TrigonometricFunction): + newexpr = TR2i(newexpr) + + # can we ever generate an I where there was none previously? + if not (newexpr.has(I) and not expr.has(I)): + expr = newexpr + return expr + +#-------------------- the old trigsimp routines --------------------- + +def trigsimp_old(expr, *, first=True, **opts): + """ + Reduces expression by using known trig identities. + + Notes + ===== + + deep: + - Apply trigsimp inside all objects with arguments + + recursive: + - Use common subexpression elimination (cse()) and apply + trigsimp recursively (this is quite expensive if the + expression is large) + + method: + - Determine the method to use. Valid choices are 'matching' (default), + 'groebner', 'combined', 'fu' and 'futrig'. If 'matching', simplify the + expression recursively by pattern matching. If 'groebner', apply an + experimental groebner basis algorithm. In this case further options + are forwarded to ``trigsimp_groebner``, please refer to its docstring. + If 'combined', first run the groebner basis algorithm with small + default parameters, then run the 'matching' algorithm. 'fu' runs the + collection of trigonometric transformations described by Fu, et al. + (see the `fu` docstring) while `futrig` runs a subset of Fu-transforms + that mimic the behavior of `trigsimp`. + + compare: + - show input and output from `trigsimp` and `futrig` when different, + but returns the `trigsimp` value. + + Examples + ======== + + >>> from sympy import trigsimp, sin, cos, log, cot + >>> from sympy.abc import x + >>> e = 2*sin(x)**2 + 2*cos(x)**2 + >>> trigsimp(e, old=True) + 2 + >>> trigsimp(log(e), old=True) + log(2*sin(x)**2 + 2*cos(x)**2) + >>> trigsimp(log(e), deep=True, old=True) + log(2) + + Using `method="groebner"` (or `"combined"`) can sometimes lead to a lot + more simplification: + + >>> e = (-sin(x) + 1)/cos(x) + cos(x)/(-sin(x) + 1) + >>> trigsimp(e, old=True) + (1 - sin(x))/cos(x) + cos(x)/(1 - sin(x)) + >>> trigsimp(e, method="groebner", old=True) + 2/cos(x) + + >>> trigsimp(1/cot(x)**2, compare=True, old=True) + futrig: tan(x)**2 + cot(x)**(-2) + + """ + old = expr + if first: + if not expr.has(*_trigs): + return expr + + trigsyms = set().union(*[t.free_symbols for t in expr.atoms(*_trigs)]) + if len(trigsyms) > 1: + from sympy.simplify.simplify import separatevars + + d = separatevars(expr) + if d.is_Mul: + d = separatevars(d, dict=True) or d + if isinstance(d, dict): + expr = 1 + for v in d.values(): + # remove hollow factoring + was = v + v = expand_mul(v) + opts['first'] = False + vnew = trigsimp(v, **opts) + if vnew == v: + vnew = was + expr *= vnew + old = expr + else: + if d.is_Add: + for s in trigsyms: + r, e = expr.as_independent(s) + if r: + opts['first'] = False + expr = r + trigsimp(e, **opts) + if not expr.is_Add: + break + old = expr + + recursive = opts.pop('recursive', False) + deep = opts.pop('deep', False) + method = opts.pop('method', 'matching') + + def groebnersimp(ex, deep, **opts): + def traverse(e): + if e.is_Atom: + return e + args = [traverse(x) for x in e.args] + if e.is_Function or e.is_Pow: + args = [trigsimp_groebner(x, **opts) for x in args] + return e.func(*args) + if deep: + ex = traverse(ex) + return trigsimp_groebner(ex, **opts) + + trigsimpfunc = { + 'matching': (lambda x, d: _trigsimp(x, d)), + 'groebner': (lambda x, d: groebnersimp(x, d, **opts)), + 'combined': (lambda x, d: _trigsimp(groebnersimp(x, + d, polynomial=True, hints=[2, tan]), + d)) + }[method] + + if recursive: + w, g = cse(expr) + g = trigsimpfunc(g[0], deep) + + for sub in reversed(w): + g = g.subs(sub[0], sub[1]) + g = trigsimpfunc(g, deep) + result = g + else: + result = trigsimpfunc(expr, deep) + + if opts.get('compare', False): + f = futrig(old) + if f != result: + print('\tfutrig:', f) + + return result + + +def _dotrig(a, b): + """Helper to tell whether ``a`` and ``b`` have the same sorts + of symbols in them -- no need to test hyperbolic patterns against + expressions that have no hyperbolics in them.""" + return a.func == b.func and ( + a.has(TrigonometricFunction) and b.has(TrigonometricFunction) or + a.has(HyperbolicFunction) and b.has(HyperbolicFunction)) + + +_trigpat = None +def _trigpats(): + global _trigpat + a, b, c = symbols('a b c', cls=Wild) + d = Wild('d', commutative=False) + + # for the simplifications like sinh/cosh -> tanh: + # DO NOT REORDER THE FIRST 14 since these are assumed to be in this + # order in _match_div_rewrite. + matchers_division = ( + (a*sin(b)**c/cos(b)**c, a*tan(b)**c, sin(b), cos(b)), + (a*tan(b)**c*cos(b)**c, a*sin(b)**c, sin(b), cos(b)), + (a*cot(b)**c*sin(b)**c, a*cos(b)**c, sin(b), cos(b)), + (a*tan(b)**c/sin(b)**c, a/cos(b)**c, sin(b), cos(b)), + (a*cot(b)**c/cos(b)**c, a/sin(b)**c, sin(b), cos(b)), + (a*cot(b)**c*tan(b)**c, a, sin(b), cos(b)), + (a*(cos(b) + 1)**c*(cos(b) - 1)**c, + a*(-sin(b)**2)**c, cos(b) + 1, cos(b) - 1), + (a*(sin(b) + 1)**c*(sin(b) - 1)**c, + a*(-cos(b)**2)**c, sin(b) + 1, sin(b) - 1), + + (a*sinh(b)**c/cosh(b)**c, a*tanh(b)**c, S.One, S.One), + (a*tanh(b)**c*cosh(b)**c, a*sinh(b)**c, S.One, S.One), + (a*coth(b)**c*sinh(b)**c, a*cosh(b)**c, S.One, S.One), + (a*tanh(b)**c/sinh(b)**c, a/cosh(b)**c, S.One, S.One), + (a*coth(b)**c/cosh(b)**c, a/sinh(b)**c, S.One, S.One), + (a*coth(b)**c*tanh(b)**c, a, S.One, S.One), + + (c*(tanh(a) + tanh(b))/(1 + tanh(a)*tanh(b)), + tanh(a + b)*c, S.One, S.One), + ) + + matchers_add = ( + (c*sin(a)*cos(b) + c*cos(a)*sin(b) + d, sin(a + b)*c + d), + (c*cos(a)*cos(b) - c*sin(a)*sin(b) + d, cos(a + b)*c + d), + (c*sin(a)*cos(b) - c*cos(a)*sin(b) + d, sin(a - b)*c + d), + (c*cos(a)*cos(b) + c*sin(a)*sin(b) + d, cos(a - b)*c + d), + (c*sinh(a)*cosh(b) + c*sinh(b)*cosh(a) + d, sinh(a + b)*c + d), + (c*cosh(a)*cosh(b) + c*sinh(a)*sinh(b) + d, cosh(a + b)*c + d), + ) + + # for cos(x)**2 + sin(x)**2 -> 1 + matchers_identity = ( + (a*sin(b)**2, a - a*cos(b)**2), + (a*tan(b)**2, a*(1/cos(b))**2 - a), + (a*cot(b)**2, a*(1/sin(b))**2 - a), + (a*sin(b + c), a*(sin(b)*cos(c) + sin(c)*cos(b))), + (a*cos(b + c), a*(cos(b)*cos(c) - sin(b)*sin(c))), + (a*tan(b + c), a*((tan(b) + tan(c))/(1 - tan(b)*tan(c)))), + + (a*sinh(b)**2, a*cosh(b)**2 - a), + (a*tanh(b)**2, a - a*(1/cosh(b))**2), + (a*coth(b)**2, a + a*(1/sinh(b))**2), + (a*sinh(b + c), a*(sinh(b)*cosh(c) + sinh(c)*cosh(b))), + (a*cosh(b + c), a*(cosh(b)*cosh(c) + sinh(b)*sinh(c))), + (a*tanh(b + c), a*((tanh(b) + tanh(c))/(1 + tanh(b)*tanh(c)))), + + ) + + # Reduce any lingering artifacts, such as sin(x)**2 changing + # to 1-cos(x)**2 when sin(x)**2 was "simpler" + artifacts = ( + (a - a*cos(b)**2 + c, a*sin(b)**2 + c, cos), + (a - a*(1/cos(b))**2 + c, -a*tan(b)**2 + c, cos), + (a - a*(1/sin(b))**2 + c, -a*cot(b)**2 + c, sin), + + (a - a*cosh(b)**2 + c, -a*sinh(b)**2 + c, cosh), + (a - a*(1/cosh(b))**2 + c, a*tanh(b)**2 + c, cosh), + (a + a*(1/sinh(b))**2 + c, a*coth(b)**2 + c, sinh), + + # same as above but with noncommutative prefactor + (a*d - a*d*cos(b)**2 + c, a*d*sin(b)**2 + c, cos), + (a*d - a*d*(1/cos(b))**2 + c, -a*d*tan(b)**2 + c, cos), + (a*d - a*d*(1/sin(b))**2 + c, -a*d*cot(b)**2 + c, sin), + + (a*d - a*d*cosh(b)**2 + c, -a*d*sinh(b)**2 + c, cosh), + (a*d - a*d*(1/cosh(b))**2 + c, a*d*tanh(b)**2 + c, cosh), + (a*d + a*d*(1/sinh(b))**2 + c, a*d*coth(b)**2 + c, sinh), + ) + + _trigpat = (a, b, c, d, matchers_division, matchers_add, + matchers_identity, artifacts) + return _trigpat + + +def _replace_mul_fpowxgpow(expr, f, g, rexp, h, rexph): + """Helper for _match_div_rewrite. + + Replace f(b_)**c_*g(b_)**(rexp(c_)) with h(b)**rexph(c) if f(b_) + and g(b_) are both positive or if c_ is an integer. + """ + # assert expr.is_Mul and expr.is_commutative and f != g + fargs = defaultdict(int) + gargs = defaultdict(int) + args = [] + for x in expr.args: + if x.is_Pow or x.func in (f, g): + b, e = x.as_base_exp() + if b.is_positive or e.is_integer: + if b.func == f: + fargs[b.args[0]] += e + continue + elif b.func == g: + gargs[b.args[0]] += e + continue + args.append(x) + common = set(fargs) & set(gargs) + hit = False + while common: + key = common.pop() + fe = fargs.pop(key) + ge = gargs.pop(key) + if fe == rexp(ge): + args.append(h(key)**rexph(fe)) + hit = True + else: + fargs[key] = fe + gargs[key] = ge + if not hit: + return expr + while fargs: + key, e = fargs.popitem() + args.append(f(key)**e) + while gargs: + key, e = gargs.popitem() + args.append(g(key)**e) + return Mul(*args) + + +_idn = lambda x: x +_midn = lambda x: -x +_one = lambda x: S.One + +def _match_div_rewrite(expr, i): + """helper for __trigsimp""" + if i == 0: + expr = _replace_mul_fpowxgpow(expr, sin, cos, + _midn, tan, _idn) + elif i == 1: + expr = _replace_mul_fpowxgpow(expr, tan, cos, + _idn, sin, _idn) + elif i == 2: + expr = _replace_mul_fpowxgpow(expr, cot, sin, + _idn, cos, _idn) + elif i == 3: + expr = _replace_mul_fpowxgpow(expr, tan, sin, + _midn, cos, _midn) + elif i == 4: + expr = _replace_mul_fpowxgpow(expr, cot, cos, + _midn, sin, _midn) + elif i == 5: + expr = _replace_mul_fpowxgpow(expr, cot, tan, + _idn, _one, _idn) + # i in (6, 7) is skipped + elif i == 8: + expr = _replace_mul_fpowxgpow(expr, sinh, cosh, + _midn, tanh, _idn) + elif i == 9: + expr = _replace_mul_fpowxgpow(expr, tanh, cosh, + _idn, sinh, _idn) + elif i == 10: + expr = _replace_mul_fpowxgpow(expr, coth, sinh, + _idn, cosh, _idn) + elif i == 11: + expr = _replace_mul_fpowxgpow(expr, tanh, sinh, + _midn, cosh, _midn) + elif i == 12: + expr = _replace_mul_fpowxgpow(expr, coth, cosh, + _midn, sinh, _midn) + elif i == 13: + expr = _replace_mul_fpowxgpow(expr, coth, tanh, + _idn, _one, _idn) + else: + return None + return expr + + +def _trigsimp(expr, deep=False): + # protect the cache from non-trig patterns; we only allow + # trig patterns to enter the cache + if expr.has(*_trigs): + return __trigsimp(expr, deep) + return expr + + +@cacheit +def __trigsimp(expr, deep=False): + """recursive helper for trigsimp""" + from sympy.simplify.fu import TR10i + + if _trigpat is None: + _trigpats() + a, b, c, d, matchers_division, matchers_add, \ + matchers_identity, artifacts = _trigpat + + if expr.is_Mul: + # do some simplifications like sin/cos -> tan: + if not expr.is_commutative: + com, nc = expr.args_cnc() + expr = _trigsimp(Mul._from_args(com), deep)*Mul._from_args(nc) + else: + for i, (pattern, simp, ok1, ok2) in enumerate(matchers_division): + if not _dotrig(expr, pattern): + continue + + newexpr = _match_div_rewrite(expr, i) + if newexpr is not None: + if newexpr != expr: + expr = newexpr + break + else: + continue + + # use SymPy matching instead + res = expr.match(pattern) + if res and res.get(c, 0): + if not res[c].is_integer: + ok = ok1.subs(res) + if not ok.is_positive: + continue + ok = ok2.subs(res) + if not ok.is_positive: + continue + # if "a" contains any of trig or hyperbolic funcs with + # argument "b" then skip the simplification + if any(w.args[0] == res[b] for w in res[a].atoms( + TrigonometricFunction, HyperbolicFunction)): + continue + # simplify and finish: + expr = simp.subs(res) + break # process below + + if expr.is_Add: + args = [] + for term in expr.args: + if not term.is_commutative: + com, nc = term.args_cnc() + nc = Mul._from_args(nc) + term = Mul._from_args(com) + else: + nc = S.One + term = _trigsimp(term, deep) + for pattern, result in matchers_identity: + res = term.match(pattern) + if res is not None: + term = result.subs(res) + break + args.append(term*nc) + if args != expr.args: + expr = Add(*args) + expr = min(expr, expand(expr), key=count_ops) + if expr.is_Add: + for pattern, result in matchers_add: + if not _dotrig(expr, pattern): + continue + expr = TR10i(expr) + if expr.has(HyperbolicFunction): + res = expr.match(pattern) + # if "d" contains any trig or hyperbolic funcs with + # argument "a" or "b" then skip the simplification; + # this isn't perfect -- see tests + if res is None or not (a in res and b in res) or any( + w.args[0] in (res[a], res[b]) for w in res[d].atoms( + TrigonometricFunction, HyperbolicFunction)): + continue + expr = result.subs(res) + break + + # Reduce any lingering artifacts, such as sin(x)**2 changing + # to 1 - cos(x)**2 when sin(x)**2 was "simpler" + for pattern, result, ex in artifacts: + if not _dotrig(expr, pattern): + continue + # Substitute a new wild that excludes some function(s) + # to help influence a better match. This is because + # sometimes, for example, 'a' would match sec(x)**2 + a_t = Wild('a', exclude=[ex]) + pattern = pattern.subs(a, a_t) + result = result.subs(a, a_t) + + m = expr.match(pattern) + was = None + while m and was != expr: + was = expr + if m[a_t] == 0 or \ + -m[a_t] in m[c].args or m[a_t] + m[c] == 0: + break + if d in m and m[a_t]*m[d] + m[c] == 0: + break + expr = result.subs(m) + m = expr.match(pattern) + m.setdefault(c, S.Zero) + + elif expr.is_Mul or expr.is_Pow or deep and expr.args: + expr = expr.func(*[_trigsimp(a, deep) for a in expr.args]) + + try: + if not expr.has(*_trigs): + raise TypeError + e = expr.atoms(exp) + new = expr.rewrite(exp, deep=deep) + if new == e: + raise TypeError + fnew = factor(new) + if fnew != new: + new = min([new, factor(new)], key=count_ops) + # if all exp that were introduced disappeared then accept it + if not (new.atoms(exp) - e): + expr = new + except TypeError: + pass + + return expr +#------------------- end of old trigsimp routines -------------------- + + +def futrig(e, *, hyper=True, **kwargs): + """Return simplified ``e`` using Fu-like transformations. + This is not the "Fu" algorithm. This is called by default + from ``trigsimp``. By default, hyperbolics subexpressions + will be simplified, but this can be disabled by setting + ``hyper=False``. + + Examples + ======== + + >>> from sympy import trigsimp, tan, sinh, tanh + >>> from sympy.simplify.trigsimp import futrig + >>> from sympy.abc import x + >>> trigsimp(1/tan(x)**2) + tan(x)**(-2) + + >>> futrig(sinh(x)/tanh(x)) + cosh(x) + + """ + from sympy.simplify.fu import hyper_as_trig + + e = sympify(e) + + if not isinstance(e, Basic): + return e + + if not e.args: + return e + + old = e + e = bottom_up(e, _futrig) + + if hyper and e.has(HyperbolicFunction): + e, f = hyper_as_trig(e) + e = f(bottom_up(e, _futrig)) + + if e != old and e.is_Mul and e.args[0].is_Rational: + # redistribute leading coeff on 2-arg Add + e = Mul(*e.as_coeff_Mul()) + return e + + +def _futrig(e): + """Helper for futrig.""" + from sympy.simplify.fu import ( + TR1, TR2, TR3, TR2i, TR10, L, TR10i, + TR8, TR6, TR15, TR16, TR111, TR5, TRmorrie, TR11, _TR11, TR14, TR22, + TR12) + + if not e.has(TrigonometricFunction): + return e + + if e.is_Mul: + coeff, e = e.as_independent(TrigonometricFunction) + else: + coeff = None + + Lops = lambda x: (L(x), x.count_ops(), _nodes(x), len(x.args), x.is_Add) + trigs = lambda x: x.has(TrigonometricFunction) + + tree = [identity, + ( + TR3, # canonical angles + TR1, # sec-csc -> cos-sin + TR12, # expand tan of sum + lambda x: _eapply(factor, x, trigs), + TR2, # tan-cot -> sin-cos + [identity, lambda x: _eapply(_mexpand, x, trigs)], + TR2i, # sin-cos ratio -> tan + lambda x: _eapply(lambda i: factor(i.normal()), x, trigs), + TR14, # factored identities + TR5, # sin-pow -> cos_pow + TR10, # sin-cos of sums -> sin-cos prod + TR11, _TR11, TR6, # reduce double angles and rewrite cos pows + lambda x: _eapply(factor, x, trigs), + TR14, # factored powers of identities + [identity, lambda x: _eapply(_mexpand, x, trigs)], + TR10i, # sin-cos products > sin-cos of sums + TRmorrie, + [identity, TR8], # sin-cos products -> sin-cos of sums + [identity, lambda x: TR2i(TR2(x))], # tan -> sin-cos -> tan + [ + lambda x: _eapply(expand_mul, TR5(x), trigs), + lambda x: _eapply( + expand_mul, TR15(x), trigs)], # pos/neg powers of sin + [ + lambda x: _eapply(expand_mul, TR6(x), trigs), + lambda x: _eapply( + expand_mul, TR16(x), trigs)], # pos/neg powers of cos + TR111, # tan, sin, cos to neg power -> cot, csc, sec + [identity, TR2i], # sin-cos ratio to tan + [identity, lambda x: _eapply( + expand_mul, TR22(x), trigs)], # tan-cot to sec-csc + TR1, TR2, TR2i, + [identity, lambda x: _eapply( + factor_terms, TR12(x), trigs)], # expand tan of sum + )] + e = greedy(tree, objective=Lops)(e) + + if coeff is not None: + e = coeff * e + + return e + + +def _is_Expr(e): + """_eapply helper to tell whether ``e`` and all its args + are Exprs.""" + if isinstance(e, Derivative): + return _is_Expr(e.expr) + if not isinstance(e, Expr): + return False + return all(_is_Expr(i) for i in e.args) + + +def _eapply(func, e, cond=None): + """Apply ``func`` to ``e`` if all args are Exprs else only + apply it to those args that *are* Exprs.""" + if not isinstance(e, Expr): + return e + if _is_Expr(e) or not e.args: + return func(e) + return e.func(*[ + _eapply(func, ei) if (cond is None or cond(ei)) else ei + for ei in e.args]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..02cfb35a765c748e70ecc36dd78d8d4432118c64 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/__init__.py @@ -0,0 +1,75 @@ +"""A module for solving all kinds of equations. + + Examples + ======== + + >>> from sympy.solvers import solve + >>> from sympy.abc import x + >>> solve(((x + 1)**5).expand(), x) + [-1] +""" +from sympy.core.assumptions import check_assumptions, failing_assumptions + +from .solvers import solve, solve_linear_system, solve_linear_system_LU, \ + solve_undetermined_coeffs, nsolve, solve_linear, checksol, \ + det_quick, inv_quick + +from sympy.solvers.diophantine.diophantine import diophantine + +from .recurr import rsolve, rsolve_poly, rsolve_ratio, rsolve_hyper + +from .ode import checkodesol, classify_ode, dsolve, \ + homogeneous_order + +from .polysys import solve_poly_system, solve_triangulated, factor_system + +from .pde import pde_separate, pde_separate_add, pde_separate_mul, \ + pdsolve, classify_pde, checkpdesol + +from .deutils import ode_order + +from .inequalities import reduce_inequalities, reduce_abs_inequality, \ + reduce_abs_inequalities, solve_poly_inequality, solve_rational_inequalities, solve_univariate_inequality + +from .decompogen import decompogen + +from .solveset import solveset, linsolve, linear_eq_to_matrix, nonlinsolve, substitution + +from .simplex import lpmin, lpmax, linprog + +# This is here instead of sympy/sets/__init__.py to avoid circular import issues +from ..core.singleton import S +Complexes = S.Complexes + +__all__ = [ + 'solve', 'solve_linear_system', 'solve_linear_system_LU', + 'solve_undetermined_coeffs', 'nsolve', 'solve_linear', 'checksol', + 'det_quick', 'inv_quick', 'check_assumptions', 'failing_assumptions', + + 'diophantine', + + 'rsolve', 'rsolve_poly', 'rsolve_ratio', 'rsolve_hyper', + + 'checkodesol', 'classify_ode', 'dsolve', 'homogeneous_order', + + 'solve_poly_system', 'solve_triangulated', 'factor_system', + + 'pde_separate', 'pde_separate_add', 'pde_separate_mul', 'pdsolve', + 'classify_pde', 'checkpdesol', + + 'ode_order', + + 'reduce_inequalities', 'reduce_abs_inequality', 'reduce_abs_inequalities', + 'solve_poly_inequality', 'solve_rational_inequalities', + 'solve_univariate_inequality', + + 'decompogen', + + 'solveset', 'linsolve', 'linear_eq_to_matrix', 'nonlinsolve', + 'substitution', + + # This is here instead of sympy/sets/__init__.py to avoid circular import issues + 'Complexes', + + 'lpmin', 'lpmax', 'linprog' +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/benchmarks/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/benchmarks/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/benchmarks/bench_solvers.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/benchmarks/bench_solvers.py new file mode 100644 index 0000000000000000000000000000000000000000..d18102873f7efcde1d111e0e8eca12e208f94663 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/benchmarks/bench_solvers.py @@ -0,0 +1,12 @@ +from sympy.core.symbol import Symbol +from sympy.matrices.dense import (eye, zeros) +from sympy.solvers.solvers import solve_linear_system + +N = 8 +M = zeros(N, N + 1) +M[:, :N] = eye(N) +S = [Symbol('A%i' % i) for i in range(N)] + + +def timeit_linsolve_trivial(): + solve_linear_system(M, *S) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/bivariate.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/bivariate.py new file mode 100644 index 0000000000000000000000000000000000000000..72f8e266a16634fa65366e1058543dfe2171ba1c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/bivariate.py @@ -0,0 +1,509 @@ +from sympy.core.add import Add +from sympy.core.exprtools import factor_terms +from sympy.core.function import expand_log, _mexpand +from sympy.core.power import Pow +from sympy.core.singleton import S +from sympy.core.sorting import ordered +from sympy.core.symbol import Dummy +from sympy.functions.elementary.exponential import (LambertW, exp, log) +from sympy.functions.elementary.miscellaneous import root +from sympy.polys.polyroots import roots +from sympy.polys.polytools import Poly, factor +from sympy.simplify.simplify import separatevars +from sympy.simplify.radsimp import collect +from sympy.simplify.simplify import powsimp +from sympy.solvers.solvers import solve, _invert +from sympy.utilities.iterables import uniq + + +def _filtered_gens(poly, symbol): + """process the generators of ``poly``, returning the set of generators that + have ``symbol``. If there are two generators that are inverses of each other, + prefer the one that has no denominator. + + Examples + ======== + + >>> from sympy.solvers.bivariate import _filtered_gens + >>> from sympy import Poly, exp + >>> from sympy.abc import x + >>> _filtered_gens(Poly(x + 1/x + exp(x)), x) + {x, exp(x)} + + """ + # TODO it would be good to pick the smallest divisible power + # instead of the base for something like x**4 + x**2 --> + # return x**2 not x + gens = {g for g in poly.gens if symbol in g.free_symbols} + for g in list(gens): + ag = 1/g + if g in gens and ag in gens: + if ag.as_numer_denom()[1] is not S.One: + g = ag + gens.remove(g) + return gens + + +def _mostfunc(lhs, func, X=None): + """Returns the term in lhs which contains the most of the + func-type things e.g. log(log(x)) wins over log(x) if both terms appear. + + ``func`` can be a function (exp, log, etc...) or any other SymPy object, + like Pow. + + If ``X`` is not ``None``, then the function returns the term composed with the + most ``func`` having the specified variable. + + Examples + ======== + + >>> from sympy.solvers.bivariate import _mostfunc + >>> from sympy import exp + >>> from sympy.abc import x, y + >>> _mostfunc(exp(x) + exp(exp(x) + 2), exp) + exp(exp(x) + 2) + >>> _mostfunc(exp(x) + exp(exp(y) + 2), exp) + exp(exp(y) + 2) + >>> _mostfunc(exp(x) + exp(exp(y) + 2), exp, x) + exp(x) + >>> _mostfunc(x, exp, x) is None + True + >>> _mostfunc(exp(x) + exp(x*y), exp, x) + exp(x) + """ + fterms = [tmp for tmp in lhs.atoms(func) if (not X or + X.is_Symbol and X in tmp.free_symbols or + not X.is_Symbol and tmp.has(X))] + if len(fterms) == 1: + return fterms[0] + elif fterms: + return max(list(ordered(fterms)), key=lambda x: x.count(func)) + return None + + +def _linab(arg, symbol): + """Return ``a, b, X`` assuming ``arg`` can be written as ``a*X + b`` + where ``X`` is a symbol-dependent factor and ``a`` and ``b`` are + independent of ``symbol``. + + Examples + ======== + + >>> from sympy.solvers.bivariate import _linab + >>> from sympy.abc import x, y + >>> from sympy import exp, S + >>> _linab(S(2), x) + (2, 0, 1) + >>> _linab(2*x, x) + (2, 0, x) + >>> _linab(y + y*x + 2*x, x) + (y + 2, y, x) + >>> _linab(3 + 2*exp(x), x) + (2, 3, exp(x)) + """ + arg = factor_terms(arg.expand()) + ind, dep = arg.as_independent(symbol) + if arg.is_Mul and dep.is_Add: + a, b, x = _linab(dep, symbol) + return ind*a, ind*b, x + if not arg.is_Add: + b = 0 + a, x = ind, dep + else: + b = ind + a, x = separatevars(dep).as_independent(symbol, as_Add=False) + if x.could_extract_minus_sign(): + a = -a + x = -x + return a, b, x + + +def _lambert(eq, x): + """ + Given an expression assumed to be in the form + ``F(X, a..f) = a*log(b*X + c) + d*X + f = 0`` + where X = g(x) and x = g^-1(X), return the Lambert solution, + ``x = g^-1(-c/b + (a/d)*W(d/(a*b)*exp(c*d/a/b)*exp(-f/a)))``. + """ + eq = _mexpand(expand_log(eq)) + mainlog = _mostfunc(eq, log, x) + if not mainlog: + return [] # violated assumptions + other = eq.subs(mainlog, 0) + if isinstance(-other, log): + eq = (eq - other).subs(mainlog, mainlog.args[0]) + mainlog = mainlog.args[0] + if not isinstance(mainlog, log): + return [] # violated assumptions + other = -(-other).args[0] + eq += other + if x not in other.free_symbols: + return [] # violated assumptions + d, f, X2 = _linab(other, x) + logterm = collect(eq - other, mainlog) + a = logterm.as_coefficient(mainlog) + if a is None or x in a.free_symbols: + return [] # violated assumptions + logarg = mainlog.args[0] + b, c, X1 = _linab(logarg, x) + if X1 != X2: + return [] # violated assumptions + + # invert the generator X1 so we have x(u) + u = Dummy('rhs') + xusolns = solve(X1 - u, x) + + # There are infinitely many branches for LambertW + # but only branches for k = -1 and 0 might be real. The k = 0 + # branch is real and the k = -1 branch is real if the LambertW argument + # in in range [-1/e, 0]. Since `solve` does not return infinite + # solutions we will only include the -1 branch if it tests as real. + # Otherwise, inclusion of any LambertW in the solution indicates to + # the user that there are imaginary solutions corresponding to + # different k values. + lambert_real_branches = [-1, 0] + sol = [] + + # solution of the given Lambert equation is like + # sol = -c/b + (a/d)*LambertW(arg, k), + # where arg = d/(a*b)*exp((c*d-b*f)/a/b) and k in lambert_real_branches. + # Instead of considering the single arg, `d/(a*b)*exp((c*d-b*f)/a/b)`, + # the individual `p` roots obtained when writing `exp((c*d-b*f)/a/b)` + # as `exp(A/p) = exp(A)**(1/p)`, where `p` is an Integer, are used. + + # calculating args for LambertW + num, den = ((c*d-b*f)/a/b).as_numer_denom() + p, den = den.as_coeff_Mul() + e = exp(num/den) + t = Dummy('t') + args = [d/(a*b)*t for t in roots(t**p - e, t).keys()] + + # calculating solutions from args + for arg in args: + for k in lambert_real_branches: + w = LambertW(arg, k) + if k and not w.is_real: + continue + rhs = -c/b + (a/d)*w + + sol.extend(xu.subs(u, rhs) for xu in xusolns) + return sol + + +def _solve_lambert(f, symbol, gens): + """Return solution to ``f`` if it is a Lambert-type expression + else raise NotImplementedError. + + For ``f(X, a..f) = a*log(b*X + c) + d*X - f = 0`` the solution + for ``X`` is ``X = -c/b + (a/d)*W(d/(a*b)*exp(c*d/a/b)*exp(f/a))``. + There are a variety of forms for `f(X, a..f)` as enumerated below: + + 1a1) + if B**B = R for R not in [0, 1] (since those cases would already + be solved before getting here) then log of both sides gives + log(B) + log(log(B)) = log(log(R)) and + X = log(B), a = 1, b = 1, c = 0, d = 1, f = log(log(R)) + 1a2) + if B*(b*log(B) + c)**a = R then log of both sides gives + log(B) + a*log(b*log(B) + c) = log(R) and + X = log(B), d=1, f=log(R) + 1b) + if a*log(b*B + c) + d*B = R and + X = B, f = R + 2a) + if (b*B + c)*exp(d*B + g) = R then log of both sides gives + log(b*B + c) + d*B + g = log(R) and + X = B, a = 1, f = log(R) - g + 2b) + if g*exp(d*B + h) - b*B = c then the log form is + log(g) + d*B + h - log(b*B + c) = 0 and + X = B, a = -1, f = -h - log(g) + 3) + if d*p**(a*B + g) - b*B = c then the log form is + log(d) + (a*B + g)*log(p) - log(b*B + c) = 0 and + X = B, a = -1, d = a*log(p), f = -log(d) - g*log(p) + """ + + def _solve_even_degree_expr(expr, t, symbol): + """Return the unique solutions of equations derived from + ``expr`` by replacing ``t`` with ``+/- symbol``. + + Parameters + ========== + + expr : Expr + The expression which includes a dummy variable t to be + replaced with +symbol and -symbol. + + symbol : Symbol + The symbol for which a solution is being sought. + + Returns + ======= + + List of unique solution of the two equations generated by + replacing ``t`` with positive and negative ``symbol``. + + Notes + ===== + + If ``expr = 2*log(t) + x/2` then solutions for + ``2*log(x) + x/2 = 0`` and ``2*log(-x) + x/2 = 0`` are + returned by this function. Though this may seem + counter-intuitive, one must note that the ``expr`` being + solved here has been derived from a different expression. For + an expression like ``eq = x**2*g(x) = 1``, if we take the + log of both sides we obtain ``log(x**2) + log(g(x)) = 0``. If + x is positive then this simplifies to + ``2*log(x) + log(g(x)) = 0``; the Lambert-solving routines will + return solutions for this, but we must also consider the + solutions for ``2*log(-x) + log(g(x))`` since those must also + be a solution of ``eq`` which has the same value when the ``x`` + in ``x**2`` is negated. If `g(x)` does not have even powers of + symbol then we do not want to replace the ``x`` there with + ``-x``. So the role of the ``t`` in the expression received by + this function is to mark where ``+/-x`` should be inserted + before obtaining the Lambert solutions. + + """ + nlhs, plhs = [ + expr.xreplace({t: sgn*symbol}) for sgn in (-1, 1)] + sols = _solve_lambert(nlhs, symbol, gens) + if plhs != nlhs: + sols.extend(_solve_lambert(plhs, symbol, gens)) + # uniq is needed for a case like + # 2*log(t) - log(-z**2) + log(z + log(x) + log(z)) + # where substituting t with +/-x gives all the same solution; + # uniq, rather than list(set()), is used to maintain canonical + # order + return list(uniq(sols)) + + nrhs, lhs = f.as_independent(symbol, as_Add=True) + rhs = -nrhs + + lamcheck = [tmp for tmp in gens + if (tmp.func in [exp, log] or + (tmp.is_Pow and symbol in tmp.exp.free_symbols))] + if not lamcheck: + raise NotImplementedError() + + if lhs.is_Add or lhs.is_Mul: + # replacing all even_degrees of symbol with dummy variable t + # since these will need special handling; non-Add/Mul do not + # need this handling + t = Dummy('t', **symbol.assumptions0) + lhs = lhs.replace( + lambda i: # find symbol**even + i.is_Pow and i.base == symbol and i.exp.is_even, + lambda i: # replace t**even + t**i.exp) + + if lhs.is_Add and lhs.has(t): + t_indep = lhs.subs(t, 0) + t_term = lhs - t_indep + _rhs = rhs - t_indep + if not t_term.is_Add and _rhs and not ( + t_term.has(S.ComplexInfinity, S.NaN)): + eq = expand_log(log(t_term) - log(_rhs)) + return _solve_even_degree_expr(eq, t, symbol) + elif lhs.is_Mul and rhs: + # this needs to happen whether t is present or not + lhs = expand_log(log(lhs), force=True) + rhs = log(rhs) + if lhs.has(t) and lhs.is_Add: + # it expanded from Mul to Add + eq = lhs - rhs + return _solve_even_degree_expr(eq, t, symbol) + + # restore symbol in lhs + lhs = lhs.xreplace({t: symbol}) + + lhs = powsimp(factor(lhs, deep=True)) + + # make sure we have inverted as completely as possible + r = Dummy() + i, lhs = _invert(lhs - r, symbol) + rhs = i.xreplace({r: rhs}) + + # For the first forms: + # + # 1a1) B**B = R will arrive here as B*log(B) = log(R) + # lhs is Mul so take log of both sides: + # log(B) + log(log(B)) = log(log(R)) + # 1a2) B*(b*log(B) + c)**a = R will arrive unchanged so + # lhs is Mul, so take log of both sides: + # log(B) + a*log(b*log(B) + c) = log(R) + # 1b) d*log(a*B + b) + c*B = R will arrive unchanged so + # lhs is Add, so isolate c*B and expand log of both sides: + # log(c) + log(B) = log(R - d*log(a*B + b)) + + soln = [] + if not soln: + mainlog = _mostfunc(lhs, log, symbol) + if mainlog: + if lhs.is_Mul and rhs != 0: + soln = _lambert(log(lhs) - log(rhs), symbol) + elif lhs.is_Add: + other = lhs.subs(mainlog, 0) + if other and not other.is_Add and [ + tmp for tmp in other.atoms(Pow) + if symbol in tmp.free_symbols]: + if not rhs: + diff = log(other) - log(other - lhs) + else: + diff = log(lhs - other) - log(rhs - other) + soln = _lambert(expand_log(diff), symbol) + else: + #it's ready to go + soln = _lambert(lhs - rhs, symbol) + + # For the next forms, + # + # collect on main exp + # 2a) (b*B + c)*exp(d*B + g) = R + # lhs is mul, so take log of both sides: + # log(b*B + c) + d*B = log(R) - g + # 2b) g*exp(d*B + h) - b*B = R + # lhs is add, so add b*B to both sides, + # take the log of both sides and rearrange to give + # log(R + b*B) - d*B = log(g) + h + + if not soln: + mainexp = _mostfunc(lhs, exp, symbol) + if mainexp: + lhs = collect(lhs, mainexp) + if lhs.is_Mul and rhs != 0: + soln = _lambert(expand_log(log(lhs) - log(rhs)), symbol) + elif lhs.is_Add: + # move all but mainexp-containing term to rhs + other = lhs.subs(mainexp, 0) + mainterm = lhs - other + rhs = rhs - other + if (mainterm.could_extract_minus_sign() and + rhs.could_extract_minus_sign()): + mainterm *= -1 + rhs *= -1 + diff = log(mainterm) - log(rhs) + soln = _lambert(expand_log(diff), symbol) + + # For the last form: + # + # 3) d*p**(a*B + g) - b*B = c + # collect on main pow, add b*B to both sides, + # take log of both sides and rearrange to give + # a*B*log(p) - log(b*B + c) = -log(d) - g*log(p) + if not soln: + mainpow = _mostfunc(lhs, Pow, symbol) + if mainpow and symbol in mainpow.exp.free_symbols: + lhs = collect(lhs, mainpow) + if lhs.is_Mul and rhs != 0: + # b*B = 0 + soln = _lambert(expand_log(log(lhs) - log(rhs)), symbol) + elif lhs.is_Add: + # move all but mainpow-containing term to rhs + other = lhs.subs(mainpow, 0) + mainterm = lhs - other + rhs = rhs - other + diff = log(mainterm) - log(rhs) + soln = _lambert(expand_log(diff), symbol) + + if not soln: + raise NotImplementedError('%s does not appear to have a solution in ' + 'terms of LambertW' % f) + + return list(ordered(soln)) + + +def bivariate_type(f, x, y, *, first=True): + """Given an expression, f, 3 tests will be done to see what type + of composite bivariate it might be, options for u(x, y) are:: + + x*y + x+y + x*y+x + x*y+y + + If it matches one of these types, ``u(x, y)``, ``P(u)`` and dummy + variable ``u`` will be returned. Solving ``P(u)`` for ``u`` and + equating the solutions to ``u(x, y)`` and then solving for ``x`` or + ``y`` is equivalent to solving the original expression for ``x`` or + ``y``. If ``x`` and ``y`` represent two functions in the same + variable, e.g. ``x = g(t)`` and ``y = h(t)``, then if ``u(x, y) - p`` + can be solved for ``t`` then these represent the solutions to + ``P(u) = 0`` when ``p`` are the solutions of ``P(u) = 0``. + + Only positive values of ``u`` are considered. + + Examples + ======== + + >>> from sympy import solve + >>> from sympy.solvers.bivariate import bivariate_type + >>> from sympy.abc import x, y + >>> eq = (x**2 - 3).subs(x, x + y) + >>> bivariate_type(eq, x, y) + (x + y, _u**2 - 3, _u) + >>> uxy, pu, u = _ + >>> usol = solve(pu, u); usol + [sqrt(3)] + >>> [solve(uxy - s) for s in solve(pu, u)] + [[{x: -y + sqrt(3)}]] + >>> all(eq.subs(s).equals(0) for sol in _ for s in sol) + True + + """ + + u = Dummy('u', positive=True) + + if first: + p = Poly(f, x, y) + f = p.as_expr() + _x = Dummy() + _y = Dummy() + rv = bivariate_type(Poly(f.subs({x: _x, y: _y}), _x, _y), _x, _y, first=False) + if rv: + reps = {_x: x, _y: y} + return rv[0].xreplace(reps), rv[1].xreplace(reps), rv[2] + return + + p = f + f = p.as_expr() + + # f(x*y) + args = Add.make_args(p.as_expr()) + new = [] + for a in args: + a = _mexpand(a.subs(x, u/y)) + free = a.free_symbols + if x in free or y in free: + break + new.append(a) + else: + return x*y, Add(*new), u + + def ok(f, v, c): + new = _mexpand(f.subs(v, c)) + free = new.free_symbols + return None if (x in free or y in free) else new + + # f(a*x + b*y) + new = [] + d = p.degree(x) + if p.degree(y) == d: + a = root(p.coeff_monomial(x**d), d) + b = root(p.coeff_monomial(y**d), d) + new = ok(f, x, (u - b*y)/a) + if new is not None: + return a*x + b*y, new, u + + # f(a*x*y + b*y) + new = [] + d = p.degree(x) + if p.degree(y) == d: + for itry in range(2): + a = root(p.coeff_monomial(x**d*y**d), d) + b = root(p.coeff_monomial(y**d), d) + new = ok(f, x, (u - b*y)/a/y) + if new is not None: + return a*x*y + b*y, new, u + x, y = y, x diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/decompogen.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/decompogen.py new file mode 100644 index 0000000000000000000000000000000000000000..ec1b3b683511a34e6f98b9839d112b87517390d8 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/decompogen.py @@ -0,0 +1,126 @@ +from sympy.core import (Function, Pow, sympify, Expr) +from sympy.core.relational import Relational +from sympy.core.singleton import S +from sympy.polys import Poly, decompose +from sympy.utilities.misc import func_name +from sympy.functions.elementary.miscellaneous import Min, Max + + +def decompogen(f, symbol): + """ + Computes General functional decomposition of ``f``. + Given an expression ``f``, returns a list ``[f_1, f_2, ..., f_n]``, + where:: + f = f_1 o f_2 o ... f_n = f_1(f_2(... f_n)) + + Note: This is a General decomposition function. It also decomposes + Polynomials. For only Polynomial decomposition see ``decompose`` in polys. + + Examples + ======== + + >>> from sympy.abc import x + >>> from sympy import decompogen, sqrt, sin, cos + >>> decompogen(sin(cos(x)), x) + [sin(x), cos(x)] + >>> decompogen(sin(x)**2 + sin(x) + 1, x) + [x**2 + x + 1, sin(x)] + >>> decompogen(sqrt(6*x**2 - 5), x) + [sqrt(x), 6*x**2 - 5] + >>> decompogen(sin(sqrt(cos(x**2 + 1))), x) + [sin(x), sqrt(x), cos(x), x**2 + 1] + >>> decompogen(x**4 + 2*x**3 - x - 1, x) + [x**2 - x - 1, x**2 + x] + + """ + f = sympify(f) + if not isinstance(f, Expr) or isinstance(f, Relational): + raise TypeError('expecting Expr but got: `%s`' % func_name(f)) + if symbol not in f.free_symbols: + return [f] + + + # ===== Simple Functions ===== # + if isinstance(f, (Function, Pow)): + if f.is_Pow and f.base == S.Exp1: + arg = f.exp + else: + arg = f.args[0] + if arg == symbol: + return [f] + return [f.subs(arg, symbol)] + decompogen(arg, symbol) + + # ===== Min/Max Functions ===== # + if isinstance(f, (Min, Max)): + args = list(f.args) + d0 = None + for i, a in enumerate(args): + if not a.has_free(symbol): + continue + d = decompogen(a, symbol) + if len(d) == 1: + d = [symbol] + d + if d0 is None: + d0 = d[1:] + elif d[1:] != d0: + # decomposition is not the same for each arg: + # mark as having no decomposition + d = [symbol] + break + args[i] = d[0] + if d[0] == symbol: + return [f] + return [f.func(*args)] + d0 + + # ===== Convert to Polynomial ===== # + fp = Poly(f) + gens = list(filter(lambda x: symbol in x.free_symbols, fp.gens)) + + if len(gens) == 1 and gens[0] != symbol: + f1 = f.subs(gens[0], symbol) + f2 = gens[0] + return [f1] + decompogen(f2, symbol) + + # ===== Polynomial decompose() ====== # + try: + return decompose(f) + except ValueError: + return [f] + + +def compogen(g_s, symbol): + """ + Returns the composition of functions. + Given a list of functions ``g_s``, returns their composition ``f``, + where: + f = g_1 o g_2 o .. o g_n + + Note: This is a General composition function. It also composes Polynomials. + For only Polynomial composition see ``compose`` in polys. + + Examples + ======== + + >>> from sympy.solvers.decompogen import compogen + >>> from sympy.abc import x + >>> from sympy import sqrt, sin, cos + >>> compogen([sin(x), cos(x)], x) + sin(cos(x)) + >>> compogen([x**2 + x + 1, sin(x)], x) + sin(x)**2 + sin(x) + 1 + >>> compogen([sqrt(x), 6*x**2 - 5], x) + sqrt(6*x**2 - 5) + >>> compogen([sin(x), sqrt(x), cos(x), x**2 + 1], x) + sin(sqrt(cos(x**2 + 1))) + >>> compogen([x**2 - x - 1, x**2 + x], x) + -x**2 - x + (x**2 + x)**2 - 1 + """ + if len(g_s) == 1: + return g_s[0] + + foo = g_s[0].subs(symbol, g_s[1]) + + if len(g_s) == 2: + return foo + + return compogen([foo] + g_s[2:], symbol) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/deutils.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/deutils.py new file mode 100644 index 0000000000000000000000000000000000000000..b13f37b5004fe7bce2545ad2c788ec3feae56025 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/deutils.py @@ -0,0 +1,273 @@ +"""Utility functions for classifying and solving +ordinary and partial differential equations. + +Contains +======== +_preprocess +ode_order +_desolve + +""" +from sympy.core import Pow +from sympy.core.function import Derivative, AppliedUndef +from sympy.core.relational import Equality +from sympy.core.symbol import Wild + +def _preprocess(expr, func=None, hint='_Integral'): + """Prepare expr for solving by making sure that differentiation + is done so that only func remains in unevaluated derivatives and + (if hint does not end with _Integral) that doit is applied to all + other derivatives. If hint is None, do not do any differentiation. + (Currently this may cause some simple differential equations to + fail.) + + In case func is None, an attempt will be made to autodetect the + function to be solved for. + + >>> from sympy.solvers.deutils import _preprocess + >>> from sympy import Derivative, Function + >>> from sympy.abc import x, y, z + >>> f, g = map(Function, 'fg') + + If f(x)**p == 0 and p>0 then we can solve for f(x)=0 + >>> _preprocess((f(x).diff(x)-4)**5, f(x)) + (Derivative(f(x), x) - 4, f(x)) + + Apply doit to derivatives that contain more than the function + of interest: + + >>> _preprocess(Derivative(f(x) + x, x)) + (Derivative(f(x), x) + 1, f(x)) + + Do others if the differentiation variable(s) intersect with those + of the function of interest or contain the function of interest: + + >>> _preprocess(Derivative(g(x), y, z), f(y)) + (0, f(y)) + >>> _preprocess(Derivative(f(y), z), f(y)) + (0, f(y)) + + Do others if the hint does not end in '_Integral' (the default + assumes that it does): + + >>> _preprocess(Derivative(g(x), y), f(x)) + (Derivative(g(x), y), f(x)) + >>> _preprocess(Derivative(f(x), y), f(x), hint='') + (0, f(x)) + + Do not do any derivatives if hint is None: + + >>> eq = Derivative(f(x) + 1, x) + Derivative(f(x), y) + >>> _preprocess(eq, f(x), hint=None) + (Derivative(f(x) + 1, x) + Derivative(f(x), y), f(x)) + + If it's not clear what the function of interest is, it must be given: + + >>> eq = Derivative(f(x) + g(x), x) + >>> _preprocess(eq, g(x)) + (Derivative(f(x), x) + Derivative(g(x), x), g(x)) + >>> try: _preprocess(eq) + ... except ValueError: print("A ValueError was raised.") + A ValueError was raised. + + """ + if isinstance(expr, Pow): + # if f(x)**p=0 then f(x)=0 (p>0) + if (expr.exp).is_positive: + expr = expr.base + derivs = expr.atoms(Derivative) + if not func: + funcs = set().union(*[d.atoms(AppliedUndef) for d in derivs]) + if len(funcs) != 1: + raise ValueError('The function cannot be ' + 'automatically detected for %s.' % expr) + func = funcs.pop() + fvars = set(func.args) + if hint is None: + return expr, func + reps = [(d, d.doit()) for d in derivs if not hint.endswith('_Integral') or + d.has(func) or set(d.variables) & fvars] + eq = expr.subs(reps) + return eq, func + + +def ode_order(expr, func): + """ + Returns the order of a given differential + equation with respect to func. + + This function is implemented recursively. + + Examples + ======== + + >>> from sympy import Function + >>> from sympy.solvers.deutils import ode_order + >>> from sympy.abc import x + >>> f, g = map(Function, ['f', 'g']) + >>> ode_order(f(x).diff(x, 2) + f(x).diff(x)**2 + + ... f(x).diff(x), f(x)) + 2 + >>> ode_order(f(x).diff(x, 2) + g(x).diff(x, 3), f(x)) + 2 + >>> ode_order(f(x).diff(x, 2) + g(x).diff(x, 3), g(x)) + 3 + + """ + a = Wild('a', exclude=[func]) + if expr.match(a): + return 0 + + if isinstance(expr, Derivative): + if expr.args[0] == func: + return len(expr.variables) + else: + args = expr.args[0].args + rv = len(expr.variables) + if args: + rv += max(ode_order(_, func) for _ in args) + return rv + else: + return max(ode_order(_, func) for _ in expr.args) if expr.args else 0 + + +def _desolve(eq, func=None, hint="default", ics=None, simplify=True, *, prep=True, **kwargs): + """This is a helper function to dsolve and pdsolve in the ode + and pde modules. + + If the hint provided to the function is "default", then a dict with + the following keys are returned + + 'func' - It provides the function for which the differential equation + has to be solved. This is useful when the expression has + more than one function in it. + + 'default' - The default key as returned by classifier functions in ode + and pde.py + + 'hint' - The hint given by the user for which the differential equation + is to be solved. If the hint given by the user is 'default', + then the value of 'hint' and 'default' is the same. + + 'order' - The order of the function as returned by ode_order + + 'match' - It returns the match as given by the classifier functions, for + the default hint. + + If the hint provided to the function is not "default" and is not in + ('all', 'all_Integral', 'best'), then a dict with the above mentioned keys + is returned along with the keys which are returned when dict in + classify_ode or classify_pde is set True + + If the hint given is in ('all', 'all_Integral', 'best'), then this function + returns a nested dict, with the keys, being the set of classified hints + returned by classifier functions, and the values being the dict of form + as mentioned above. + + Key 'eq' is a common key to all the above mentioned hints which returns an + expression if eq given by user is an Equality. + + See Also + ======== + classify_ode(ode.py) + classify_pde(pde.py) + """ + if isinstance(eq, Equality): + eq = eq.lhs - eq.rhs + + # preprocess the equation and find func if not given + if prep or func is None: + eq, func = _preprocess(eq, func) + prep = False + + # type is an argument passed by the solve functions in ode and pde.py + # that identifies whether the function caller is an ordinary + # or partial differential equation. Accordingly corresponding + # changes are made in the function. + type = kwargs.get('type', None) + xi = kwargs.get('xi') + eta = kwargs.get('eta') + x0 = kwargs.get('x0', 0) + terms = kwargs.get('n') + + if type == 'ode': + from sympy.solvers.ode import classify_ode, allhints + classifier = classify_ode + string = 'ODE ' + dummy = '' + + elif type == 'pde': + from sympy.solvers.pde import classify_pde, allhints + classifier = classify_pde + string = 'PDE ' + dummy = 'p' + + # Magic that should only be used internally. Prevents classify_ode from + # being called more than it needs to be by passing its results through + # recursive calls. + if kwargs.get('classify', True): + hints = classifier(eq, func, dict=True, ics=ics, xi=xi, eta=eta, + n=terms, x0=x0, hint=hint, prep=prep) + + else: + # Here is what all this means: + # + # hint: The hint method given to _desolve() by the user. + # hints: The dictionary of hints that match the DE, along with other + # information (including the internal pass-through magic). + # default: The default hint to return, the first hint from allhints + # that matches the hint; obtained from classify_ode(). + # match: Dictionary containing the match dictionary for each hint + # (the parts of the DE for solving). When going through the + # hints in "all", this holds the match string for the current + # hint. + # order: The order of the DE, as determined by ode_order(). + hints = kwargs.get('hint', + {'default': hint, + hint: kwargs['match'], + 'order': kwargs['order']}) + if not hints['default']: + # classify_ode will set hints['default'] to None if no hints match. + if hint not in allhints and hint != 'default': + raise ValueError("Hint not recognized: " + hint) + elif hint not in hints['ordered_hints'] and hint != 'default': + raise ValueError(string + str(eq) + " does not match hint " + hint) + # If dsolve can't solve the purely algebraic equation then dsolve will raise + # ValueError + elif hints['order'] == 0: + raise ValueError( + str(eq) + " is not a solvable differential equation in " + str(func)) + else: + raise NotImplementedError(dummy + "solve" + ": Cannot solve " + str(eq)) + if hint == 'default': + return _desolve(eq, func, ics=ics, hint=hints['default'], simplify=simplify, + prep=prep, x0=x0, classify=False, order=hints['order'], + match=hints[hints['default']], xi=xi, eta=eta, n=terms, type=type) + elif hint in ('all', 'all_Integral', 'best'): + retdict = {} + gethints = set(hints) - {'order', 'default', 'ordered_hints'} + if hint == 'all_Integral': + for i in hints: + if i.endswith('_Integral'): + gethints.remove(i.removesuffix('_Integral')) + # special cases + for k in ["1st_homogeneous_coeff_best", "1st_power_series", + "lie_group", "2nd_power_series_ordinary", "2nd_power_series_regular"]: + if k in gethints: + gethints.remove(k) + for i in gethints: + sol = _desolve(eq, func, ics=ics, hint=i, x0=x0, simplify=simplify, prep=prep, + classify=False, n=terms, order=hints['order'], match=hints[i], type=type) + retdict[i] = sol + retdict['all'] = True + retdict['eq'] = eq + return retdict + elif hint not in allhints: # and hint not in ('default', 'ordered_hints'): + raise ValueError("Hint not recognized: " + hint) + elif hint not in hints: + raise ValueError(string + str(eq) + " does not match hint " + hint) + else: + # Key added to identify the hint needed to solve the equation + hints['hint'] = hint + hints.update({'func': func, 'eq': eq}) + return hints diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..23c21242208d6f520c130250ecdce43382b9d868 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/__init__.py @@ -0,0 +1,5 @@ +from .diophantine import diophantine, classify_diop, diop_solve + +__all__ = [ + 'diophantine', 'classify_diop', 'diop_solve' +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/diophantine.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/diophantine.py new file mode 100644 index 0000000000000000000000000000000000000000..ffdef6344451c96ed48dff099cf8f02494f4b504 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/diophantine.py @@ -0,0 +1,3980 @@ +from __future__ import annotations + +from sympy.core.add import Add +from sympy.core.assumptions import check_assumptions +from sympy.core.containers import Tuple +from sympy.core.exprtools import factor_terms +from sympy.core.function import _mexpand +from sympy.core.mul import Mul +from sympy.core.numbers import Rational, int_valued +from sympy.core.intfunc import igcdex, ilcm, igcd, integer_nthroot, isqrt +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.sorting import default_sort_key, ordered +from sympy.core.symbol import Symbol, symbols +from sympy.core.sympify import _sympify +from sympy.external.gmpy import jacobi, remove, invert, iroot +from sympy.functions.elementary.complexes import sign +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.matrices.dense import MutableDenseMatrix as Matrix +from sympy.ntheory.factor_ import divisors, factorint, perfect_power +from sympy.ntheory.generate import nextprime +from sympy.ntheory.primetest import is_square, isprime +from sympy.ntheory.modular import symmetric_residue +from sympy.ntheory.residue_ntheory import sqrt_mod, sqrt_mod_iter +from sympy.polys.polyerrors import GeneratorsNeeded +from sympy.polys.polytools import Poly, factor_list +from sympy.simplify.simplify import signsimp +from sympy.solvers.solveset import solveset_real +from sympy.utilities import numbered_symbols +from sympy.utilities.misc import as_int, filldedent +from sympy.utilities.iterables import (is_sequence, subsets, permute_signs, + signed_permutations, ordered_partitions) + + +# these are imported with 'from sympy.solvers.diophantine import * +__all__ = ['diophantine', 'classify_diop'] + + +class DiophantineSolutionSet(set): + """ + Container for a set of solutions to a particular diophantine equation. + + The base representation is a set of tuples representing each of the solutions. + + Parameters + ========== + + symbols : list + List of free symbols in the original equation. + parameters: list + List of parameters to be used in the solution. + + Examples + ======== + + Adding solutions: + + >>> from sympy.solvers.diophantine.diophantine import DiophantineSolutionSet + >>> from sympy.abc import x, y, t, u + >>> s1 = DiophantineSolutionSet([x, y], [t, u]) + >>> s1 + set() + >>> s1.add((2, 3)) + >>> s1.add((-1, u)) + >>> s1 + {(-1, u), (2, 3)} + >>> s2 = DiophantineSolutionSet([x, y], [t, u]) + >>> s2.add((3, 4)) + >>> s1.update(*s2) + >>> s1 + {(-1, u), (2, 3), (3, 4)} + + Conversion of solutions into dicts: + + >>> list(s1.dict_iterator()) + [{x: -1, y: u}, {x: 2, y: 3}, {x: 3, y: 4}] + + Substituting values: + + >>> s3 = DiophantineSolutionSet([x, y], [t, u]) + >>> s3.add((t**2, t + u)) + >>> s3 + {(t**2, t + u)} + >>> s3.subs({t: 2, u: 3}) + {(4, 5)} + >>> s3.subs(t, -1) + {(1, u - 1)} + >>> s3.subs(t, 3) + {(9, u + 3)} + + Evaluation at specific values. Positional arguments are given in the same order as the parameters: + + >>> s3(-2, 3) + {(4, 1)} + >>> s3(5) + {(25, u + 5)} + >>> s3(None, 2) + {(t**2, t + 2)} + """ + + def __init__(self, symbols_seq, parameters): + super().__init__() + + if not is_sequence(symbols_seq): + raise ValueError("Symbols must be given as a sequence.") + + if not is_sequence(parameters): + raise ValueError("Parameters must be given as a sequence.") + + self.symbols = tuple(symbols_seq) + self.parameters = tuple(parameters) + + def add(self, solution): + if len(solution) != len(self.symbols): + raise ValueError("Solution should have a length of %s, not %s" % (len(self.symbols), len(solution))) + # make solution canonical wrt sign (i.e. no -x unless x is also present as an arg) + args = set(solution) + for i in range(len(solution)): + x = solution[i] + if not type(x) is int and (-x).is_Symbol and -x not in args: + solution = [_.subs(-x, x) for _ in solution] + super().add(Tuple(*solution)) + + def update(self, *solutions): + for solution in solutions: + self.add(solution) + + def dict_iterator(self): + for solution in ordered(self): + yield dict(zip(self.symbols, solution)) + + def subs(self, *args, **kwargs): + result = DiophantineSolutionSet(self.symbols, self.parameters) + for solution in self: + result.add(solution.subs(*args, **kwargs)) + return result + + def __call__(self, *args): + if len(args) > len(self.parameters): + raise ValueError("Evaluation should have at most %s values, not %s" % (len(self.parameters), len(args))) + rep = {p: v for p, v in zip(self.parameters, args) if v is not None} + return self.subs(rep) + + +class DiophantineEquationType: + """ + Internal representation of a particular diophantine equation type. + + Parameters + ========== + + equation : + The diophantine equation that is being solved. + free_symbols : list (optional) + The symbols being solved for. + + Attributes + ========== + + total_degree : + The maximum of the degrees of all terms in the equation + homogeneous : + Does the equation contain a term of degree 0 + homogeneous_order : + Does the equation contain any coefficient that is in the symbols being solved for + dimension : + The number of symbols being solved for + """ + name: str + + def __init__(self, equation, free_symbols=None): + self.equation = _sympify(equation).expand(force=True) + + if free_symbols is not None: + self.free_symbols = free_symbols + else: + self.free_symbols = list(self.equation.free_symbols) + self.free_symbols.sort(key=default_sort_key) + + if not self.free_symbols: + raise ValueError('equation should have 1 or more free symbols') + + self.coeff = self.equation.as_coefficients_dict() + if not all(int_valued(c) for c in self.coeff.values()): + raise TypeError("Coefficients should be Integers") + + self.total_degree = Poly(self.equation).total_degree() + self.homogeneous = 1 not in self.coeff + self.homogeneous_order = not (set(self.coeff) & set(self.free_symbols)) + self.dimension = len(self.free_symbols) + self._parameters = None + + def matches(self): + """ + Determine whether the given equation can be matched to the particular equation type. + """ + return False + + @property + def n_parameters(self): + return self.dimension + + @property + def parameters(self): + if self._parameters is None: + self._parameters = symbols('t_:%i' % (self.n_parameters,), integer=True) + return self._parameters + + def solve(self, parameters=None, limit=None) -> DiophantineSolutionSet: + raise NotImplementedError('No solver has been written for %s.' % self.name) + + def pre_solve(self, parameters=None): + if not self.matches(): + raise ValueError("This equation does not match the %s equation type." % self.name) + + if parameters is not None: + if len(parameters) != self.n_parameters: + raise ValueError("Expected %s parameter(s) but got %s" % (self.n_parameters, len(parameters))) + + self._parameters = parameters + + +class Univariate(DiophantineEquationType): + """ + Representation of a univariate diophantine equation. + + A univariate diophantine equation is an equation of the form + `a_{0} + a_{1}x + a_{2}x^2 + .. + a_{n}x^n = 0` where `a_{1}, a_{2}, ..a_{n}` are + integer constants and `x` is an integer variable. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import Univariate + >>> from sympy.abc import x + >>> Univariate((x - 2)*(x - 3)**2).solve() # solves equation (x - 2)*(x - 3)**2 == 0 + {(2,), (3,)} + + """ + + name = 'univariate' + + def matches(self): + return self.dimension == 1 + + def solve(self, parameters=None, limit=None): + self.pre_solve(parameters) + + result = DiophantineSolutionSet(self.free_symbols, parameters=self.parameters) + for i in solveset_real(self.equation, self.free_symbols[0]).intersect(S.Integers): + result.add((i,)) + return result + + +class Linear(DiophantineEquationType): + """ + Representation of a linear diophantine equation. + + A linear diophantine equation is an equation of the form `a_{1}x_{1} + + a_{2}x_{2} + .. + a_{n}x_{n} = 0` where `a_{1}, a_{2}, ..a_{n}` are + integer constants and `x_{1}, x_{2}, ..x_{n}` are integer variables. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import Linear + >>> from sympy.abc import x, y, z + >>> l1 = Linear(2*x - 3*y - 5) + >>> l1.matches() # is this equation linear + True + >>> l1.solve() # solves equation 2*x - 3*y - 5 == 0 + {(3*t_0 - 5, 2*t_0 - 5)} + + Here x = -3*t_0 - 5 and y = -2*t_0 - 5 + + >>> Linear(2*x - 3*y - 4*z -3).solve() + {(t_0, 2*t_0 + 4*t_1 + 3, -t_0 - 3*t_1 - 3)} + + """ + + name = 'linear' + + def matches(self): + return self.total_degree == 1 + + def solve(self, parameters=None, limit=None): + self.pre_solve(parameters) + + coeff = self.coeff + var = self.free_symbols + + if 1 in coeff: + # negate coeff[] because input is of the form: ax + by + c == 0 + # but is used as: ax + by == -c + c = -coeff[1] + else: + c = 0 + + result = DiophantineSolutionSet(var, parameters=self.parameters) + params = result.parameters + + if len(var) == 1: + q, r = divmod(c, coeff[var[0]]) + if not r: + result.add((q,)) + return result + + ''' + base_solution_linear() can solve diophantine equations of the form: + + a*x + b*y == c + + We break down multivariate linear diophantine equations into a + series of bivariate linear diophantine equations which can then + be solved individually by base_solution_linear(). + + Consider the following: + + a_0*x_0 + a_1*x_1 + a_2*x_2 == c + + which can be re-written as: + + a_0*x_0 + g_0*y_0 == c + + where + + g_0 == gcd(a_1, a_2) + + and + + y == (a_1*x_1)/g_0 + (a_2*x_2)/g_0 + + This leaves us with two binary linear diophantine equations. + For the first equation: + + a == a_0 + b == g_0 + c == c + + For the second: + + a == a_1/g_0 + b == a_2/g_0 + c == the solution we find for y_0 in the first equation. + + The arrays A and B are the arrays of integers used for + 'a' and 'b' in each of the n-1 bivariate equations we solve. + ''' + + A = [coeff[v] for v in var] + B = [] + if len(var) > 2: + B.append(igcd(A[-2], A[-1])) + A[-2] = A[-2] // B[0] + A[-1] = A[-1] // B[0] + for i in range(len(A) - 3, 0, -1): + gcd = igcd(B[0], A[i]) + B[0] = B[0] // gcd + A[i] = A[i] // gcd + B.insert(0, gcd) + B.append(A[-1]) + + ''' + Consider the trivariate linear equation: + + 4*x_0 + 6*x_1 + 3*x_2 == 2 + + This can be re-written as: + + 4*x_0 + 3*y_0 == 2 + + where + + y_0 == 2*x_1 + x_2 + (Note that gcd(3, 6) == 3) + + The complete integral solution to this equation is: + + x_0 == 2 + 3*t_0 + y_0 == -2 - 4*t_0 + + where 't_0' is any integer. + + Now that we have a solution for 'x_0', find 'x_1' and 'x_2': + + 2*x_1 + x_2 == -2 - 4*t_0 + + We can then solve for '-2' and '-4' independently, + and combine the results: + + 2*x_1a + x_2a == -2 + x_1a == 0 + t_0 + x_2a == -2 - 2*t_0 + + 2*x_1b + x_2b == -4*t_0 + x_1b == 0*t_0 + t_1 + x_2b == -4*t_0 - 2*t_1 + + ==> + + x_1 == t_0 + t_1 + x_2 == -2 - 6*t_0 - 2*t_1 + + where 't_0' and 't_1' are any integers. + + Note that: + + 4*(2 + 3*t_0) + 6*(t_0 + t_1) + 3*(-2 - 6*t_0 - 2*t_1) == 2 + + for any integral values of 't_0', 't_1'; as required. + + This method is generalised for many variables, below. + + ''' + solutions = [] + for Ai, Bi in zip(A, B): + tot_x, tot_y = [], [] + + for arg in Add.make_args(c): + if arg.is_Integer: + # example: 5 -> k = 5 + k, p = arg, S.One + pnew = params[0] + else: # arg is a Mul or Symbol + # example: 3*t_1 -> k = 3 + # example: t_0 -> k = 1 + k, p = arg.as_coeff_Mul() + pnew = params[params.index(p) + 1] + + sol = sol_x, sol_y = base_solution_linear(k, Ai, Bi, pnew) + + if p is S.One: + if None in sol: + return result + else: + # convert a + b*pnew -> a*p + b*pnew + if isinstance(sol_x, Add): + sol_x = sol_x.args[0]*p + sol_x.args[1] + if isinstance(sol_y, Add): + sol_y = sol_y.args[0]*p + sol_y.args[1] + + tot_x.append(sol_x) + tot_y.append(sol_y) + + solutions.append(Add(*tot_x)) + c = Add(*tot_y) + + solutions.append(c) + result.add(solutions) + return result + + +class BinaryQuadratic(DiophantineEquationType): + """ + Representation of a binary quadratic diophantine equation. + + A binary quadratic diophantine equation is an equation of the + form `Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0`, where `A, B, C, D, E, + F` are integer constants and `x` and `y` are integer variables. + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy.solvers.diophantine.diophantine import BinaryQuadratic + >>> b1 = BinaryQuadratic(x**3 + y**2 + 1) + >>> b1.matches() + False + >>> b2 = BinaryQuadratic(x**2 + y**2 + 2*x + 2*y + 2) + >>> b2.matches() + True + >>> b2.solve() + {(-1, -1)} + + References + ========== + + .. [1] Methods to solve Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0, [online], + Available: https://www.alpertron.com.ar/METHODS.HTM + .. [2] Solving the equation ax^2+ bxy + cy^2 + dx + ey + f= 0, [online], + Available: https://web.archive.org/web/20160323033111/http://www.jpr2718.org/ax2p.pdf + + """ + + name = 'binary_quadratic' + + def matches(self): + return self.total_degree == 2 and self.dimension == 2 + + def solve(self, parameters=None, limit=None) -> DiophantineSolutionSet: + self.pre_solve(parameters) + + var = self.free_symbols + coeff = self.coeff + + x, y = var + + A = coeff[x**2] + B = coeff[x*y] + C = coeff[y**2] + D = coeff[x] + E = coeff[y] + F = coeff[S.One] + + A, B, C, D, E, F = [as_int(i) for i in _remove_gcd(A, B, C, D, E, F)] + + # (1) Simple-Hyperbolic case: A = C = 0, B != 0 + # In this case equation can be converted to (Bx + E)(By + D) = DE - BF + # We consider two cases; DE - BF = 0 and DE - BF != 0 + # More details, https://www.alpertron.com.ar/METHODS.HTM#SHyperb + + result = DiophantineSolutionSet(var, self.parameters) + t, u = result.parameters + + discr = B**2 - 4*A*C + if A == 0 and C == 0 and B != 0: + + if D*E - B*F == 0: + q, r = divmod(E, B) + if not r: + result.add((-q, t)) + q, r = divmod(D, B) + if not r: + result.add((t, -q)) + else: + div = divisors(D*E - B*F) + div = div + [-term for term in div] + for d in div: + x0, r = divmod(d - E, B) + if not r: + q, r = divmod(D*E - B*F, d) + if not r: + y0, r = divmod(q - D, B) + if not r: + result.add((x0, y0)) + + # (2) Parabolic case: B**2 - 4*A*C = 0 + # There are two subcases to be considered in this case. + # sqrt(c)D - sqrt(a)E = 0 and sqrt(c)D - sqrt(a)E != 0 + # More Details, https://www.alpertron.com.ar/METHODS.HTM#Parabol + + elif discr == 0: + + if A == 0: + s = BinaryQuadratic(self.equation, free_symbols=[y, x]).solve(parameters=[t, u]) + for soln in s: + result.add((soln[1], soln[0])) + + else: + g = sign(A)*igcd(A, C) + a = A // g + c = C // g + e = sign(B / A) + + sqa = isqrt(a) + sqc = isqrt(c) + _c = e*sqc*D - sqa*E + if not _c: + z = Symbol("z", real=True) + eq = sqa*g*z**2 + D*z + sqa*F + roots = solveset_real(eq, z).intersect(S.Integers) + for root in roots: + ans = diop_solve(sqa*x + e*sqc*y - root) + result.add((ans[0], ans[1])) + + elif int_valued(c): + solve_x = lambda u: -e*sqc*g*_c*t**2 - (E + 2*e*sqc*g*u)*t \ + - (e*sqc*g*u**2 + E*u + e*sqc*F) // _c + + solve_y = lambda u: sqa*g*_c*t**2 + (D + 2*sqa*g*u)*t \ + + (sqa*g*u**2 + D*u + sqa*F) // _c + + for z0 in range(0, abs(_c)): + # Check if the coefficients of y and x obtained are integers or not + if (divisible(sqa*g*z0**2 + D*z0 + sqa*F, _c) and + divisible(e*sqc*g*z0**2 + E*z0 + e*sqc*F, _c)): + result.add((solve_x(z0), solve_y(z0))) + + # (3) Method used when B**2 - 4*A*C is a square, is described in p. 6 of the below paper + # by John P. Robertson. + # https://web.archive.org/web/20160323033111/http://www.jpr2718.org/ax2p.pdf + + elif is_square(discr): + if A != 0: + r = sqrt(discr) + u, v = symbols("u, v", integer=True) + eq = _mexpand( + 4*A*r*u*v + 4*A*D*(B*v + r*u + r*v - B*u) + + 2*A*4*A*E*(u - v) + 4*A*r*4*A*F) + + solution = diop_solve(eq, t) + + for s0, t0 in solution: + + num = B*t0 + r*s0 + r*t0 - B*s0 + x_0 = S(num) / (4*A*r) + y_0 = S(s0 - t0) / (2*r) + if isinstance(s0, Symbol) or isinstance(t0, Symbol): + if len(check_param(x_0, y_0, 4*A*r, parameters)) > 0: + ans = check_param(x_0, y_0, 4*A*r, parameters) + result.update(*ans) + elif x_0.is_Integer and y_0.is_Integer: + if is_solution_quad(var, coeff, x_0, y_0): + result.add((x_0, y_0)) + + else: + s = BinaryQuadratic(self.equation, free_symbols=var[::-1]).solve(parameters=[t, u]) # Interchange x and y + while s: + result.add(s.pop()[::-1]) # and solution <--------+ + + # (4) B**2 - 4*A*C > 0 and B**2 - 4*A*C not a square or B**2 - 4*A*C < 0 + + else: + + P, Q = _transformation_to_DN(var, coeff) + D, N = _find_DN(var, coeff) + solns_pell = diop_DN(D, N) + + if D < 0: + for x0, y0 in solns_pell: + for x in [-x0, x0]: + for y in [-y0, y0]: + s = P*Matrix([x, y]) + Q + try: + result.add([as_int(_) for _ in s]) + except ValueError: + pass + else: + # In this case equation can be transformed into a Pell equation + + solns_pell = set(solns_pell) + solns_pell.update((-X, -Y) for X, Y in list(solns_pell)) + + a = diop_DN(D, 1) + T = a[0][0] + U = a[0][1] + + if all(int_valued(_) for _ in P[:4] + Q[:2]): + for r, s in solns_pell: + _a = (r + s*sqrt(D))*(T + U*sqrt(D))**t + _b = (r - s*sqrt(D))*(T - U*sqrt(D))**t + x_n = _mexpand(S(_a + _b) / 2) + y_n = _mexpand(S(_a - _b) / (2*sqrt(D))) + s = P*Matrix([x_n, y_n]) + Q + result.add(s) + + else: + L = ilcm(*[_.q for _ in P[:4] + Q[:2]]) + + k = 1 + + T_k = T + U_k = U + + while (T_k - 1) % L != 0 or U_k % L != 0: + T_k, U_k = T_k*T + D*U_k*U, T_k*U + U_k*T + k += 1 + + for X, Y in solns_pell: + + for i in range(k): + if all(int_valued(_) for _ in P*Matrix([X, Y]) + Q): + _a = (X + sqrt(D)*Y)*(T_k + sqrt(D)*U_k)**t + _b = (X - sqrt(D)*Y)*(T_k - sqrt(D)*U_k)**t + Xt = S(_a + _b) / 2 + Yt = S(_a - _b) / (2*sqrt(D)) + s = P*Matrix([Xt, Yt]) + Q + result.add(s) + + X, Y = X*T + D*U*Y, X*U + Y*T + + return result + + +class InhomogeneousTernaryQuadratic(DiophantineEquationType): + """ + + Representation of an inhomogeneous ternary quadratic. + + No solver is currently implemented for this equation type. + + """ + + name = 'inhomogeneous_ternary_quadratic' + + def matches(self): + if not (self.total_degree == 2 and self.dimension == 3): + return False + if not self.homogeneous: + return False + return not self.homogeneous_order + + +class HomogeneousTernaryQuadraticNormal(DiophantineEquationType): + """ + Representation of a homogeneous ternary quadratic normal diophantine equation. + + Examples + ======== + + >>> from sympy.abc import x, y, z + >>> from sympy.solvers.diophantine.diophantine import HomogeneousTernaryQuadraticNormal + >>> HomogeneousTernaryQuadraticNormal(4*x**2 - 5*y**2 + z**2).solve() + {(1, 2, 4)} + + """ + + name = 'homogeneous_ternary_quadratic_normal' + + def matches(self): + if not (self.total_degree == 2 and self.dimension == 3): + return False + if not self.homogeneous: + return False + if not self.homogeneous_order: + return False + + nonzero = [k for k in self.coeff if self.coeff[k]] + return len(nonzero) == 3 and all(i**2 in nonzero for i in self.free_symbols) + + def solve(self, parameters=None, limit=None) -> DiophantineSolutionSet: + self.pre_solve(parameters) + + var = self.free_symbols + coeff = self.coeff + + x, y, z = var + + a = coeff[x**2] + b = coeff[y**2] + c = coeff[z**2] + + (sqf_of_a, sqf_of_b, sqf_of_c), (a_1, b_1, c_1), (a_2, b_2, c_2) = \ + sqf_normal(a, b, c, steps=True) + + A = -a_2*c_2 + B = -b_2*c_2 + + result = DiophantineSolutionSet(var, parameters=self.parameters) + + # If following two conditions are satisfied then there are no solutions + if A < 0 and B < 0: + return result + + if ( + sqrt_mod(-b_2*c_2, a_2) is None or + sqrt_mod(-c_2*a_2, b_2) is None or + sqrt_mod(-a_2*b_2, c_2) is None): + return result + + z_0, x_0, y_0 = descent(A, B) + + z_0, q = _rational_pq(z_0, abs(c_2)) + x_0 *= q + y_0 *= q + + x_0, y_0, z_0 = _remove_gcd(x_0, y_0, z_0) + + # Holzer reduction + if sign(a) == sign(b): + x_0, y_0, z_0 = holzer(x_0, y_0, z_0, abs(a_2), abs(b_2), abs(c_2)) + elif sign(a) == sign(c): + x_0, z_0, y_0 = holzer(x_0, z_0, y_0, abs(a_2), abs(c_2), abs(b_2)) + else: + y_0, z_0, x_0 = holzer(y_0, z_0, x_0, abs(b_2), abs(c_2), abs(a_2)) + + x_0 = reconstruct(b_1, c_1, x_0) + y_0 = reconstruct(a_1, c_1, y_0) + z_0 = reconstruct(a_1, b_1, z_0) + + sq_lcm = ilcm(sqf_of_a, sqf_of_b, sqf_of_c) + + x_0 = abs(x_0*sq_lcm // sqf_of_a) + y_0 = abs(y_0*sq_lcm // sqf_of_b) + z_0 = abs(z_0*sq_lcm // sqf_of_c) + + result.add(_remove_gcd(x_0, y_0, z_0)) + return result + + +class HomogeneousTernaryQuadratic(DiophantineEquationType): + """ + Representation of a homogeneous ternary quadratic diophantine equation. + + Examples + ======== + + >>> from sympy.abc import x, y, z + >>> from sympy.solvers.diophantine.diophantine import HomogeneousTernaryQuadratic + >>> HomogeneousTernaryQuadratic(x**2 + y**2 - 3*z**2 + x*y).solve() + {(-1, 2, 1)} + >>> HomogeneousTernaryQuadratic(3*x**2 + y**2 - 3*z**2 + 5*x*y + y*z).solve() + {(3, 12, 13)} + + """ + + name = 'homogeneous_ternary_quadratic' + + def matches(self): + if not (self.total_degree == 2 and self.dimension == 3): + return False + if not self.homogeneous: + return False + if not self.homogeneous_order: + return False + + nonzero = [k for k in self.coeff if self.coeff[k]] + return not (len(nonzero) == 3 and all(i**2 in nonzero for i in self.free_symbols)) + + def solve(self, parameters=None, limit=None): + self.pre_solve(parameters) + + _var = self.free_symbols + coeff = self.coeff + + x, y, z = _var + var = [x, y, z] + + # Equations of the form B*x*y + C*z*x + E*y*z = 0 and At least two of the + # coefficients A, B, C are non-zero. + # There are infinitely many solutions for the equation. + # Ex: (0, 0, t), (0, t, 0), (t, 0, 0) + # Equation can be re-written as y*(B*x + E*z) = -C*x*z and we can find rather + # unobvious solutions. Set y = -C and B*x + E*z = x*z. The latter can be solved by + # using methods for binary quadratic diophantine equations. Let's select the + # solution which minimizes |x| + |z| + + result = DiophantineSolutionSet(var, parameters=self.parameters) + + def unpack_sol(sol): + if len(sol) > 0: + return list(sol)[0] + return None, None, None + + if not any(coeff[i**2] for i in var): + if coeff[x*z]: + sols = diophantine(coeff[x*y]*x + coeff[y*z]*z - x*z) + s = min(sols, key=lambda r: abs(r[0]) + abs(r[1])) + result.add(_remove_gcd(s[0], -coeff[x*z], s[1])) + return result + + var[0], var[1] = _var[1], _var[0] + y_0, x_0, z_0 = unpack_sol(_diop_ternary_quadratic(var, coeff)) + if x_0 is not None: + result.add((x_0, y_0, z_0)) + return result + + if coeff[x**2] == 0: + # If the coefficient of x is zero change the variables + if coeff[y**2] == 0: + var[0], var[2] = _var[2], _var[0] + z_0, y_0, x_0 = unpack_sol(_diop_ternary_quadratic(var, coeff)) + + else: + var[0], var[1] = _var[1], _var[0] + y_0, x_0, z_0 = unpack_sol(_diop_ternary_quadratic(var, coeff)) + + else: + if coeff[x*y] or coeff[x*z]: + # Apply the transformation x --> X - (B*y + C*z)/(2*A) + A = coeff[x**2] + B = coeff[x*y] + C = coeff[x*z] + D = coeff[y**2] + E = coeff[y*z] + F = coeff[z**2] + + _coeff = {} + + _coeff[x**2] = 4*A**2 + _coeff[y**2] = 4*A*D - B**2 + _coeff[z**2] = 4*A*F - C**2 + _coeff[y*z] = 4*A*E - 2*B*C + _coeff[x*y] = 0 + _coeff[x*z] = 0 + + x_0, y_0, z_0 = unpack_sol(_diop_ternary_quadratic(var, _coeff)) + + if x_0 is None: + return result + + p, q = _rational_pq(B*y_0 + C*z_0, 2*A) + x_0, y_0, z_0 = x_0*q - p, y_0*q, z_0*q + + elif coeff[z*y] != 0: + if coeff[y**2] == 0: + if coeff[z**2] == 0: + # Equations of the form A*x**2 + E*yz = 0. + A = coeff[x**2] + E = coeff[y*z] + + b, a = _rational_pq(-E, A) + + x_0, y_0, z_0 = b, a, b + + else: + # Ax**2 + E*y*z + F*z**2 = 0 + var[0], var[2] = _var[2], _var[0] + z_0, y_0, x_0 = unpack_sol(_diop_ternary_quadratic(var, coeff)) + + else: + # A*x**2 + D*y**2 + E*y*z + F*z**2 = 0, C may be zero + var[0], var[1] = _var[1], _var[0] + y_0, x_0, z_0 = unpack_sol(_diop_ternary_quadratic(var, coeff)) + + else: + # Ax**2 + D*y**2 + F*z**2 = 0, C may be zero + x_0, y_0, z_0 = unpack_sol(_diop_ternary_quadratic_normal(var, coeff)) + + if x_0 is None: + return result + + result.add(_remove_gcd(x_0, y_0, z_0)) + return result + + +class InhomogeneousGeneralQuadratic(DiophantineEquationType): + """ + + Representation of an inhomogeneous general quadratic. + + No solver is currently implemented for this equation type. + + """ + + name = 'inhomogeneous_general_quadratic' + + def matches(self): + if not (self.total_degree == 2 and self.dimension >= 3): + return False + if not self.homogeneous_order: + return True + # there may be Pow keys like x**2 or Mul keys like x*y + return any(k.is_Mul for k in self.coeff) and not self.homogeneous + + +class HomogeneousGeneralQuadratic(DiophantineEquationType): + """ + + Representation of a homogeneous general quadratic. + + No solver is currently implemented for this equation type. + + """ + + name = 'homogeneous_general_quadratic' + + def matches(self): + if not (self.total_degree == 2 and self.dimension >= 3): + return False + if not self.homogeneous_order: + return False + # there may be Pow keys like x**2 or Mul keys like x*y + return any(k.is_Mul for k in self.coeff) and self.homogeneous + + +class GeneralSumOfSquares(DiophantineEquationType): + r""" + Representation of the diophantine equation + + `x_{1}^2 + x_{2}^2 + . . . + x_{n}^2 - k = 0`. + + Details + ======= + + When `n = 3` if `k = 4^a(8m + 7)` for some `a, m \in Z` then there will be + no solutions. Refer [1]_ for more details. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import GeneralSumOfSquares + >>> from sympy.abc import a, b, c, d, e + >>> GeneralSumOfSquares(a**2 + b**2 + c**2 + d**2 + e**2 - 2345).solve() + {(15, 22, 22, 24, 24)} + + By default only 1 solution is returned. Use the `limit` keyword for more: + + >>> sorted(GeneralSumOfSquares(a**2 + b**2 + c**2 + d**2 + e**2 - 2345).solve(limit=3)) + [(15, 22, 22, 24, 24), (16, 19, 24, 24, 24), (16, 20, 22, 23, 26)] + + References + ========== + + .. [1] Representing an integer as a sum of three squares, [online], + Available: + https://proofwiki.org/wiki/Integer_as_Sum_of_Three_Squares + """ + + name = 'general_sum_of_squares' + + def matches(self): + if not (self.total_degree == 2 and self.dimension >= 3): + return False + if not self.homogeneous_order: + return False + if any(k.is_Mul for k in self.coeff): + return False + return all(self.coeff[k] == 1 for k in self.coeff if k != 1) + + def solve(self, parameters=None, limit=1): + self.pre_solve(parameters) + + var = self.free_symbols + k = -int(self.coeff[1]) + n = self.dimension + + result = DiophantineSolutionSet(var, parameters=self.parameters) + + if k < 0 or limit < 1: + return result + + signs = [-1 if x.is_nonpositive else 1 for x in var] + negs = signs.count(-1) != 0 + + took = 0 + for t in sum_of_squares(k, n, zeros=True): + if negs: + result.add([signs[i]*j for i, j in enumerate(t)]) + else: + result.add(t) + took += 1 + if took == limit: + break + return result + + +class GeneralPythagorean(DiophantineEquationType): + """ + Representation of the general pythagorean equation, + `a_{1}^2x_{1}^2 + a_{2}^2x_{2}^2 + . . . + a_{n}^2x_{n}^2 - a_{n + 1}^2x_{n + 1}^2 = 0`. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import GeneralPythagorean + >>> from sympy.abc import a, b, c, d, e, x, y, z, t + >>> GeneralPythagorean(a**2 + b**2 + c**2 - d**2).solve() + {(t_0**2 + t_1**2 - t_2**2, 2*t_0*t_2, 2*t_1*t_2, t_0**2 + t_1**2 + t_2**2)} + >>> GeneralPythagorean(9*a**2 - 4*b**2 + 16*c**2 + 25*d**2 + e**2).solve(parameters=[x, y, z, t]) + {(-10*t**2 + 10*x**2 + 10*y**2 + 10*z**2, 15*t**2 + 15*x**2 + 15*y**2 + 15*z**2, 15*t*x, 12*t*y, 60*t*z)} + """ + + name = 'general_pythagorean' + + def matches(self): + if not (self.total_degree == 2 and self.dimension >= 3): + return False + if not self.homogeneous_order: + return False + if any(k.is_Mul for k in self.coeff): + return False + if all(self.coeff[k] == 1 for k in self.coeff if k != 1): + return False + if not all(is_square(abs(self.coeff[k])) for k in self.coeff): + return False + # all but one has the same sign + # e.g. 4*x**2 + y**2 - 4*z**2 + return abs(sum(sign(self.coeff[k]) for k in self.coeff)) == self.dimension - 2 + + @property + def n_parameters(self): + return self.dimension - 1 + + def solve(self, parameters=None, limit=1): + self.pre_solve(parameters) + + coeff = self.coeff + var = self.free_symbols + n = self.dimension + + if sign(coeff[var[0] ** 2]) + sign(coeff[var[1] ** 2]) + sign(coeff[var[2] ** 2]) < 0: + for key in coeff.keys(): + coeff[key] = -coeff[key] + + result = DiophantineSolutionSet(var, parameters=self.parameters) + + index = 0 + + for i, v in enumerate(var): + if sign(coeff[v ** 2]) == -1: + index = i + + m = result.parameters + + ith = sum(m_i ** 2 for m_i in m) + L = [ith - 2 * m[n - 2] ** 2] + L.extend([2 * m[i] * m[n - 2] for i in range(n - 2)]) + sol = L[:index] + [ith] + L[index:] + + lcm = 1 + for i, v in enumerate(var): + if i == index or (index > 0 and i == 0) or (index == 0 and i == 1): + lcm = ilcm(lcm, sqrt(abs(coeff[v ** 2]))) + else: + s = sqrt(coeff[v ** 2]) + lcm = ilcm(lcm, s if _odd(s) else s // 2) + + for i, v in enumerate(var): + sol[i] = (lcm * sol[i]) / sqrt(abs(coeff[v ** 2])) + + result.add(sol) + return result + + +class CubicThue(DiophantineEquationType): + """ + Representation of a cubic Thue diophantine equation. + + A cubic Thue diophantine equation is a polynomial of the form + `f(x, y) = r` of degree 3, where `x` and `y` are integers + and `r` is a rational number. + + No solver is currently implemented for this equation type. + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy.solvers.diophantine.diophantine import CubicThue + >>> c1 = CubicThue(x**3 + y**2 + 1) + >>> c1.matches() + True + + """ + + name = 'cubic_thue' + + def matches(self): + return self.total_degree == 3 and self.dimension == 2 + + +class GeneralSumOfEvenPowers(DiophantineEquationType): + """ + Representation of the diophantine equation + + `x_{1}^e + x_{2}^e + . . . + x_{n}^e - k = 0` + + where `e` is an even, integer power. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import GeneralSumOfEvenPowers + >>> from sympy.abc import a, b + >>> GeneralSumOfEvenPowers(a**4 + b**4 - (2**4 + 3**4)).solve() + {(2, 3)} + + """ + + name = 'general_sum_of_even_powers' + + def matches(self): + if not self.total_degree > 3: + return False + if self.total_degree % 2 != 0: + return False + if not all(k.is_Pow and k.exp == self.total_degree for k in self.coeff if k != 1): + return False + return all(self.coeff[k] == 1 for k in self.coeff if k != 1) + + def solve(self, parameters=None, limit=1): + self.pre_solve(parameters) + + var = self.free_symbols + coeff = self.coeff + + p = None + for q in coeff.keys(): + if q.is_Pow and coeff[q]: + p = q.exp + + k = len(var) + n = -coeff[1] + + result = DiophantineSolutionSet(var, parameters=self.parameters) + + if n < 0 or limit < 1: + return result + + sign = [-1 if x.is_nonpositive else 1 for x in var] + negs = sign.count(-1) != 0 + + took = 0 + for t in power_representation(n, p, k): + if negs: + result.add([sign[i]*j for i, j in enumerate(t)]) + else: + result.add(t) + took += 1 + if took == limit: + break + return result + +# these types are known (but not necessarily handled) +# note that order is important here (in the current solver state) +all_diop_classes = [ + Linear, + Univariate, + BinaryQuadratic, + InhomogeneousTernaryQuadratic, + HomogeneousTernaryQuadraticNormal, + HomogeneousTernaryQuadratic, + InhomogeneousGeneralQuadratic, + HomogeneousGeneralQuadratic, + GeneralSumOfSquares, + GeneralPythagorean, + CubicThue, + GeneralSumOfEvenPowers, +] + +diop_known = {diop_class.name for diop_class in all_diop_classes} + + +def _remove_gcd(*x): + try: + g = igcd(*x) + except ValueError: + fx = list(filter(None, x)) + if len(fx) < 2: + return x + g = igcd(*[i.as_content_primitive()[0] for i in fx]) + except TypeError: + raise TypeError('_remove_gcd(a,b,c) or _remove_gcd(*container)') + if g == 1: + return x + return tuple([i//g for i in x]) + + +def _rational_pq(a, b): + # return `(numer, denom)` for a/b; sign in numer and gcd removed + return _remove_gcd(sign(b)*a, abs(b)) + + +def _nint_or_floor(p, q): + # return nearest int to p/q; in case of tie return floor(p/q) + w, r = divmod(p, q) + if abs(r) <= abs(q)//2: + return w + return w + 1 + + +def _odd(i): + return i % 2 != 0 + + +def _even(i): + return i % 2 == 0 + + +def diophantine(eq, param=symbols("t", integer=True), syms=None, + permute=False): + """ + Simplify the solution procedure of diophantine equation ``eq`` by + converting it into a product of terms which should equal zero. + + Explanation + =========== + + For example, when solving, `x^2 - y^2 = 0` this is treated as + `(x + y)(x - y) = 0` and `x + y = 0` and `x - y = 0` are solved + independently and combined. Each term is solved by calling + ``diop_solve()``. (Although it is possible to call ``diop_solve()`` + directly, one must be careful to pass an equation in the correct + form and to interpret the output correctly; ``diophantine()`` is + the public-facing function to use in general.) + + Output of ``diophantine()`` is a set of tuples. The elements of the + tuple are the solutions for each variable in the equation and + are arranged according to the alphabetic ordering of the variables. + e.g. For an equation with two variables, `a` and `b`, the first + element of the tuple is the solution for `a` and the second for `b`. + + Usage + ===== + + ``diophantine(eq, t, syms)``: Solve the diophantine + equation ``eq``. + ``t`` is the optional parameter to be used by ``diop_solve()``. + ``syms`` is an optional list of symbols which determines the + order of the elements in the returned tuple. + + By default, only the base solution is returned. If ``permute`` is set to + True then permutations of the base solution and/or permutations of the + signs of the values will be returned when applicable. + + Details + ======= + + ``eq`` should be an expression which is assumed to be zero. + ``t`` is the parameter to be used in the solution. + + Examples + ======== + + >>> from sympy import diophantine + >>> from sympy.abc import a, b + >>> eq = a**4 + b**4 - (2**4 + 3**4) + >>> diophantine(eq) + {(2, 3)} + >>> diophantine(eq, permute=True) + {(-3, -2), (-3, 2), (-2, -3), (-2, 3), (2, -3), (2, 3), (3, -2), (3, 2)} + + >>> from sympy.abc import x, y, z + >>> diophantine(x**2 - y**2) + {(t_0, -t_0), (t_0, t_0)} + + >>> diophantine(x*(2*x + 3*y - z)) + {(0, n1, n2), (t_0, t_1, 2*t_0 + 3*t_1)} + >>> diophantine(x**2 + 3*x*y + 4*x) + {(0, n1), (-3*t_0 - 4, t_0)} + + See Also + ======== + + diop_solve + sympy.utilities.iterables.permute_signs + sympy.utilities.iterables.signed_permutations + """ + + eq = _sympify(eq) + + if isinstance(eq, Eq): + eq = eq.lhs - eq.rhs + + try: + var = list(eq.expand(force=True).free_symbols) + var.sort(key=default_sort_key) + if syms: + if not is_sequence(syms): + raise TypeError( + 'syms should be given as a sequence, e.g. a list') + syms = [i for i in syms if i in var] + if syms != var: + dict_sym_index = dict(zip(syms, range(len(syms)))) + return {tuple([t[dict_sym_index[i]] for i in var]) + for t in diophantine(eq, param, permute=permute)} + n, d = eq.as_numer_denom() + if n.is_number: + return set() + if not d.is_number: + dsol = diophantine(d) + good = diophantine(n) - dsol + return {s for s in good if _mexpand(d.subs(zip(var, s)))} + eq = factor_terms(n) + assert not eq.is_number + eq = eq.as_independent(*var, as_Add=False)[1] + p = Poly(eq) + assert not any(g.is_number for g in p.gens) + eq = p.as_expr() + assert eq.is_polynomial() + except (GeneratorsNeeded, AssertionError): + raise TypeError(filldedent(''' + Equation should be a polynomial with Rational coefficients.''')) + + # permute only sign + do_permute_signs = False + # permute sign and values + do_permute_signs_var = False + # permute few signs + permute_few_signs = False + try: + # if we know that factoring should not be attempted, skip + # the factoring step + v, c, t = classify_diop(eq) + + # check for permute sign + if permute: + len_var = len(v) + permute_signs_for = [ + GeneralSumOfSquares.name, + GeneralSumOfEvenPowers.name] + permute_signs_check = [ + HomogeneousTernaryQuadratic.name, + HomogeneousTernaryQuadraticNormal.name, + BinaryQuadratic.name] + if t in permute_signs_for: + do_permute_signs_var = True + elif t in permute_signs_check: + # if all the variables in eq have even powers + # then do_permute_sign = True + if len_var == 3: + var_mul = list(subsets(v, 2)) + # here var_mul is like [(x, y), (x, z), (y, z)] + xy_coeff = True + x_coeff = True + var1_mul_var2 = (a[0]*a[1] for a in var_mul) + # if coeff(y*z), coeff(y*x), coeff(x*z) is not 0 then + # `xy_coeff` => True and do_permute_sign => False. + # Means no permuted solution. + for v1_mul_v2 in var1_mul_var2: + try: + coeff = c[v1_mul_v2] + except KeyError: + coeff = 0 + xy_coeff = bool(xy_coeff) and bool(coeff) + var_mul = list(subsets(v, 1)) + # here var_mul is like [(x,), (y, )] + for v1 in var_mul: + try: + coeff = c[v1[0]] + except KeyError: + coeff = 0 + x_coeff = bool(x_coeff) and bool(coeff) + if not any((xy_coeff, x_coeff)): + # means only x**2, y**2, z**2, const is present + do_permute_signs = True + elif not x_coeff: + permute_few_signs = True + elif len_var == 2: + var_mul = list(subsets(v, 2)) + # here var_mul is like [(x, y)] + xy_coeff = True + x_coeff = True + var1_mul_var2 = (x[0]*x[1] for x in var_mul) + for v1_mul_v2 in var1_mul_var2: + try: + coeff = c[v1_mul_v2] + except KeyError: + coeff = 0 + xy_coeff = bool(xy_coeff) and bool(coeff) + var_mul = list(subsets(v, 1)) + # here var_mul is like [(x,), (y, )] + for v1 in var_mul: + try: + coeff = c[v1[0]] + except KeyError: + coeff = 0 + x_coeff = bool(x_coeff) and bool(coeff) + if not any((xy_coeff, x_coeff)): + # means only x**2, y**2 and const is present + # so we can get more soln by permuting this soln. + do_permute_signs = True + elif not x_coeff: + # when coeff(x), coeff(y) is not present then signs of + # x, y can be permuted such that their sign are same + # as sign of x*y. + # e.g 1. (x_val,y_val)=> (x_val,y_val), (-x_val,-y_val) + # 2. (-x_vall, y_val)=> (-x_val,y_val), (x_val,-y_val) + permute_few_signs = True + if t == 'general_sum_of_squares': + # trying to factor such expressions will sometimes hang + terms = [(eq, 1)] + else: + raise TypeError + except (TypeError, NotImplementedError): + fl = factor_list(eq) + if fl[0].is_Rational and fl[0] != 1: + return diophantine(eq/fl[0], param=param, syms=syms, permute=permute) + terms = fl[1] + + sols = set() + + for term in terms: + + base, _ = term + var_t, _, eq_type = classify_diop(base, _dict=False) + _, base = signsimp(base, evaluate=False).as_coeff_Mul() + solution = diop_solve(base, param) + + if eq_type in [ + Linear.name, + HomogeneousTernaryQuadratic.name, + HomogeneousTernaryQuadraticNormal.name, + GeneralPythagorean.name]: + sols.add(merge_solution(var, var_t, solution)) + + elif eq_type in [ + BinaryQuadratic.name, + GeneralSumOfSquares.name, + GeneralSumOfEvenPowers.name, + Univariate.name]: + sols.update(merge_solution(var, var_t, sol) for sol in solution) + + else: + raise NotImplementedError('unhandled type: %s' % eq_type) + + sols.discard(()) + null = tuple([0]*len(var)) + # if there is no solution, return trivial solution + if not sols and eq.subs(zip(var, null)).is_zero: + if all(check_assumptions(val, **s.assumptions0) is not False for val, s in zip(null, var)): + sols.add(null) + + final_soln = set() + for sol in sols: + if all(int_valued(s) for s in sol): + if do_permute_signs: + permuted_sign = set(permute_signs(sol)) + final_soln.update(permuted_sign) + elif permute_few_signs: + lst = list(permute_signs(sol)) + lst = list(filter(lambda x: x[0]*x[1] == sol[1]*sol[0], lst)) + permuted_sign = set(lst) + final_soln.update(permuted_sign) + elif do_permute_signs_var: + permuted_sign_var = set(signed_permutations(sol)) + final_soln.update(permuted_sign_var) + else: + final_soln.add(sol) + else: + final_soln.add(sol) + return final_soln + + +def merge_solution(var, var_t, solution): + """ + This is used to construct the full solution from the solutions of sub + equations. + + Explanation + =========== + + For example when solving the equation `(x - y)(x^2 + y^2 - z^2) = 0`, + solutions for each of the equations `x - y = 0` and `x^2 + y^2 - z^2` are + found independently. Solutions for `x - y = 0` are `(x, y) = (t, t)`. But + we should introduce a value for z when we output the solution for the + original equation. This function converts `(t, t)` into `(t, t, n_{1})` + where `n_{1}` is an integer parameter. + """ + sol = [] + + if None in solution: + return () + + solution = iter(solution) + params = numbered_symbols("n", integer=True, start=1) + for v in var: + if v in var_t: + sol.append(next(solution)) + else: + sol.append(next(params)) + + for val, symb in zip(sol, var): + if check_assumptions(val, **symb.assumptions0) is False: + return () + + return tuple(sol) + + +def _diop_solve(eq, params=None): + for diop_type in all_diop_classes: + if diop_type(eq).matches(): + return diop_type(eq).solve(parameters=params) + + +def diop_solve(eq, param=symbols("t", integer=True)): + """ + Solves the diophantine equation ``eq``. + + Explanation + =========== + + Unlike ``diophantine()``, factoring of ``eq`` is not attempted. Uses + ``classify_diop()`` to determine the type of the equation and calls + the appropriate solver function. + + Use of ``diophantine()`` is recommended over other helper functions. + ``diop_solve()`` can return either a set or a tuple depending on the + nature of the equation. All non-trivial solutions are returned: assumptions + on symbols are ignored. + + Usage + ===== + + ``diop_solve(eq, t)``: Solve diophantine equation, ``eq`` using ``t`` + as a parameter if needed. + + Details + ======= + + ``eq`` should be an expression which is assumed to be zero. + ``t`` is a parameter to be used in the solution. + + Examples + ======== + + >>> from sympy.solvers.diophantine import diop_solve + >>> from sympy.abc import x, y, z, w + >>> diop_solve(2*x + 3*y - 5) + (3*t_0 - 5, 5 - 2*t_0) + >>> diop_solve(4*x + 3*y - 4*z + 5) + (t_0, 8*t_0 + 4*t_1 + 5, 7*t_0 + 3*t_1 + 5) + >>> diop_solve(x + 3*y - 4*z + w - 6) + (t_0, t_0 + t_1, 6*t_0 + 5*t_1 + 4*t_2 - 6, 5*t_0 + 4*t_1 + 3*t_2 - 6) + >>> diop_solve(x**2 + y**2 - 5) + {(-2, -1), (-2, 1), (-1, -2), (-1, 2), (1, -2), (1, 2), (2, -1), (2, 1)} + + + See Also + ======== + + diophantine() + """ + var, coeff, eq_type = classify_diop(eq, _dict=False) + + if eq_type == Linear.name: + return diop_linear(eq, param) + + elif eq_type == BinaryQuadratic.name: + return diop_quadratic(eq, param) + + elif eq_type == HomogeneousTernaryQuadratic.name: + return diop_ternary_quadratic(eq, parameterize=True) + + elif eq_type == HomogeneousTernaryQuadraticNormal.name: + return diop_ternary_quadratic_normal(eq, parameterize=True) + + elif eq_type == GeneralPythagorean.name: + return diop_general_pythagorean(eq, param) + + elif eq_type == Univariate.name: + return diop_univariate(eq) + + elif eq_type == GeneralSumOfSquares.name: + return diop_general_sum_of_squares(eq, limit=S.Infinity) + + elif eq_type == GeneralSumOfEvenPowers.name: + return diop_general_sum_of_even_powers(eq, limit=S.Infinity) + + if eq_type is not None and eq_type not in diop_known: + raise ValueError(filldedent(''' + Although this type of equation was identified, it is not yet + handled. It should, however, be listed in `diop_known` at the + top of this file. Developers should see comments at the end of + `classify_diop`. + ''')) # pragma: no cover + else: + raise NotImplementedError( + 'No solver has been written for %s.' % eq_type) + + +def classify_diop(eq, _dict=True): + # docstring supplied externally + + matched = False + diop_type = None + for diop_class in all_diop_classes: + diop_type = diop_class(eq) + if diop_type.matches(): + matched = True + break + + if matched: + return diop_type.free_symbols, dict(diop_type.coeff) if _dict else diop_type.coeff, diop_type.name + + # new diop type instructions + # -------------------------- + # if this error raises and the equation *can* be classified, + # * it should be identified in the if-block above + # * the type should be added to the diop_known + # if a solver can be written for it, + # * a dedicated handler should be written (e.g. diop_linear) + # * it should be passed to that handler in diop_solve + raise NotImplementedError(filldedent(''' + This equation is not yet recognized or else has not been + simplified sufficiently to put it in a form recognized by + diop_classify().''')) + + +classify_diop.func_doc = ( # type: ignore + ''' + Helper routine used by diop_solve() to find information about ``eq``. + + Explanation + =========== + + Returns a tuple containing the type of the diophantine equation + along with the variables (free symbols) and their coefficients. + Variables are returned as a list and coefficients are returned + as a dict with the key being the respective term and the constant + term is keyed to 1. The type is one of the following: + + * %s + + Usage + ===== + + ``classify_diop(eq)``: Return variables, coefficients and type of the + ``eq``. + + Details + ======= + + ``eq`` should be an expression which is assumed to be zero. + ``_dict`` is for internal use: when True (default) a dict is returned, + otherwise a defaultdict which supplies 0 for missing keys is returned. + + Examples + ======== + + >>> from sympy.solvers.diophantine import classify_diop + >>> from sympy.abc import x, y, z, w, t + >>> classify_diop(4*x + 6*y - 4) + ([x, y], {1: -4, x: 4, y: 6}, 'linear') + >>> classify_diop(x + 3*y -4*z + 5) + ([x, y, z], {1: 5, x: 1, y: 3, z: -4}, 'linear') + >>> classify_diop(x**2 + y**2 - x*y + x + 5) + ([x, y], {1: 5, x: 1, x**2: 1, y**2: 1, x*y: -1}, 'binary_quadratic') + ''' % ('\n * '.join(sorted(diop_known)))) + + +def diop_linear(eq, param=symbols("t", integer=True)): + """ + Solves linear diophantine equations. + + A linear diophantine equation is an equation of the form `a_{1}x_{1} + + a_{2}x_{2} + .. + a_{n}x_{n} = 0` where `a_{1}, a_{2}, ..a_{n}` are + integer constants and `x_{1}, x_{2}, ..x_{n}` are integer variables. + + Usage + ===== + + ``diop_linear(eq)``: Returns a tuple containing solutions to the + diophantine equation ``eq``. Values in the tuple is arranged in the same + order as the sorted variables. + + Details + ======= + + ``eq`` is a linear diophantine equation which is assumed to be zero. + ``param`` is the parameter to be used in the solution. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_linear + >>> from sympy.abc import x, y, z + >>> diop_linear(2*x - 3*y - 5) # solves equation 2*x - 3*y - 5 == 0 + (3*t_0 - 5, 2*t_0 - 5) + + Here x = -3*t_0 - 5 and y = -2*t_0 - 5 + + >>> diop_linear(2*x - 3*y - 4*z -3) + (t_0, 2*t_0 + 4*t_1 + 3, -t_0 - 3*t_1 - 3) + + See Also + ======== + + diop_quadratic(), diop_ternary_quadratic(), diop_general_pythagorean(), + diop_general_sum_of_squares() + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type == Linear.name: + parameters = None + if param is not None: + parameters = symbols('%s_0:%i' % (param, len(var)), integer=True) + + result = Linear(eq).solve(parameters=parameters) + + if param is None: + result = result(*[0]*len(result.parameters)) + + if len(result) > 0: + return list(result)[0] + else: + return tuple([None]*len(result.parameters)) + + +def base_solution_linear(c, a, b, t=None): + """ + Return the base solution for the linear equation, `ax + by = c`. + + Explanation + =========== + + Used by ``diop_linear()`` to find the base solution of a linear + Diophantine equation. If ``t`` is given then the parametrized solution is + returned. + + Usage + ===== + + ``base_solution_linear(c, a, b, t)``: ``a``, ``b``, ``c`` are coefficients + in `ax + by = c` and ``t`` is the parameter to be used in the solution. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import base_solution_linear + >>> from sympy.abc import t + >>> base_solution_linear(5, 2, 3) # equation 2*x + 3*y = 5 + (-5, 5) + >>> base_solution_linear(0, 5, 7) # equation 5*x + 7*y = 0 + (0, 0) + >>> base_solution_linear(5, 2, 3, t) # equation 2*x + 3*y = 5 + (3*t - 5, 5 - 2*t) + >>> base_solution_linear(0, 5, 7, t) # equation 5*x + 7*y = 0 + (7*t, -5*t) + """ + a, b, c = _remove_gcd(a, b, c) + + if c == 0: + if t is None: + return (0, 0) + if b < 0: + t = -t + return (b*t, -a*t) + + x0, y0, d = igcdex(abs(a), abs(b)) + x0 *= sign(a) + y0 *= sign(b) + if c % d: + return (None, None) + if t is None: + return (c*x0, c*y0) + if b < 0: + t = -t + return (c*x0 + b*t, c*y0 - a*t) + + +def diop_univariate(eq): + """ + Solves a univariate diophantine equations. + + Explanation + =========== + + A univariate diophantine equation is an equation of the form + `a_{0} + a_{1}x + a_{2}x^2 + .. + a_{n}x^n = 0` where `a_{1}, a_{2}, ..a_{n}` are + integer constants and `x` is an integer variable. + + Usage + ===== + + ``diop_univariate(eq)``: Returns a set containing solutions to the + diophantine equation ``eq``. + + Details + ======= + + ``eq`` is a univariate diophantine equation which is assumed to be zero. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_univariate + >>> from sympy.abc import x + >>> diop_univariate((x - 2)*(x - 3)**2) # solves equation (x - 2)*(x - 3)**2 == 0 + {(2,), (3,)} + + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type == Univariate.name: + return {(int(i),) for i in solveset_real( + eq, var[0]).intersect(S.Integers)} + + +def divisible(a, b): + """ + Returns `True` if ``a`` is divisible by ``b`` and `False` otherwise. + """ + return not a % b + + +def diop_quadratic(eq, param=symbols("t", integer=True)): + """ + Solves quadratic diophantine equations. + + i.e. equations of the form `Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0`. Returns a + set containing the tuples `(x, y)` which contains the solutions. If there + are no solutions then `(None, None)` is returned. + + Usage + ===== + + ``diop_quadratic(eq, param)``: ``eq`` is a quadratic binary diophantine + equation. ``param`` is used to indicate the parameter to be used in the + solution. + + Details + ======= + + ``eq`` should be an expression which is assumed to be zero. + ``param`` is a parameter to be used in the solution. + + Examples + ======== + + >>> from sympy.abc import x, y, t + >>> from sympy.solvers.diophantine.diophantine import diop_quadratic + >>> diop_quadratic(x**2 + y**2 + 2*x + 2*y + 2, t) + {(-1, -1)} + + References + ========== + + .. [1] Methods to solve Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0, [online], + Available: https://www.alpertron.com.ar/METHODS.HTM + .. [2] Solving the equation ax^2+ bxy + cy^2 + dx + ey + f= 0, [online], + Available: https://web.archive.org/web/20160323033111/http://www.jpr2718.org/ax2p.pdf + + See Also + ======== + + diop_linear(), diop_ternary_quadratic(), diop_general_sum_of_squares(), + diop_general_pythagorean() + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type == BinaryQuadratic.name: + if param is not None: + parameters = [param, Symbol("u", integer=True)] + else: + parameters = None + return set(BinaryQuadratic(eq).solve(parameters=parameters)) + + +def is_solution_quad(var, coeff, u, v): + """ + Check whether `(u, v)` is solution to the quadratic binary diophantine + equation with the variable list ``var`` and coefficient dictionary + ``coeff``. + + Not intended for use by normal users. + """ + reps = dict(zip(var, (u, v))) + eq = Add(*[j*i.xreplace(reps) for i, j in coeff.items()]) + return _mexpand(eq) == 0 + + +def diop_DN(D, N, t=symbols("t", integer=True)): + """ + Solves the equation `x^2 - Dy^2 = N`. + + Explanation + =========== + + Mainly concerned with the case `D > 0, D` is not a perfect square, + which is the same as the generalized Pell equation. The LMM + algorithm [1]_ is used to solve this equation. + + Returns one solution tuple, (`x, y)` for each class of the solutions. + Other solutions of the class can be constructed according to the + values of ``D`` and ``N``. + + Usage + ===== + + ``diop_DN(D, N, t)``: D and N are integers as in `x^2 - Dy^2 = N` and + ``t`` is the parameter to be used in the solutions. + + Details + ======= + + ``D`` and ``N`` correspond to D and N in the equation. + ``t`` is the parameter to be used in the solutions. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_DN + >>> diop_DN(13, -4) # Solves equation x**2 - 13*y**2 = -4 + [(3, 1), (393, 109), (36, 10)] + + The output can be interpreted as follows: There are three fundamental + solutions to the equation `x^2 - 13y^2 = -4` given by (3, 1), (393, 109) + and (36, 10). Each tuple is in the form (x, y), i.e. solution (3, 1) means + that `x = 3` and `y = 1`. + + >>> diop_DN(986, 1) # Solves equation x**2 - 986*y**2 = 1 + [(49299, 1570)] + + See Also + ======== + + find_DN(), diop_bf_DN() + + References + ========== + + .. [1] Solving the generalized Pell equation x**2 - D*y**2 = N, John P. + Robertson, July 31, 2004, Pages 16 - 17. [online], Available: + https://web.archive.org/web/20160323033128/http://www.jpr2718.org/pell.pdf + """ + if D < 0: + if N == 0: + return [(0, 0)] + if N < 0: + return [] + # N > 0: + sol = [] + for d in divisors(square_factor(N), generator=True): + for x, y in cornacchia(1, int(-D), int(N // d**2)): + sol.append((d*x, d*y)) + if D == -1: + sol.append((d*y, d*x)) + return sol + + if D == 0: + if N < 0: + return [] + if N == 0: + return [(0, t)] + sN, _exact = integer_nthroot(N, 2) + if _exact: + return [(sN, t)] + return [] + + # D > 0 + sD, _exact = integer_nthroot(D, 2) + if _exact: + if N == 0: + return [(sD*t, t)] + + sol = [] + for y in range(floor(sign(N)*(N - 1)/(2*sD)) + 1): + try: + sq, _exact = integer_nthroot(D*y**2 + N, 2) + except ValueError: + _exact = False + if _exact: + sol.append((sq, y)) + return sol + + if 1 < N**2 < D: + # It is much faster to call `_special_diop_DN`. + return _special_diop_DN(D, N) + + if N == 0: + return [(0, 0)] + + sol = [] + if abs(N) == 1: + pqa = PQa(0, 1, D) + *_, prev_B, prev_G = next(pqa) + for j, (*_, a, _, _B, _G) in enumerate(pqa): + if a == 2*sD: + break + prev_B, prev_G = _B, _G + if j % 2: + if N == 1: + sol.append((prev_G, prev_B)) + return sol + if N == -1: + return [(prev_G, prev_B)] + for _ in range(j): + *_, _B, _G = next(pqa) + return [(_G, _B)] + + for f in divisors(square_factor(N), generator=True): + m = N // f**2 + am = abs(m) + for sqm in sqrt_mod(D, am, all_roots=True): + z = symmetric_residue(sqm, am) + pqa = PQa(z, am, D) + *_, prev_B, prev_G = next(pqa) + for _ in range(length(z, am, D) - 1): + _, q, *_, _B, _G = next(pqa) + if abs(q) == 1: + if prev_G**2 - D*prev_B**2 == m: + sol.append((f*prev_G, f*prev_B)) + elif a := diop_DN(D, -1): + sol.append((f*(prev_G*a[0][0] + prev_B*D*a[0][1]), + f*(prev_G*a[0][1] + prev_B*a[0][0]))) + break + prev_B, prev_G = _B, _G + return sol + + +def _special_diop_DN(D, N): + """ + Solves the equation `x^2 - Dy^2 = N` for the special case where + `1 < N**2 < D` and `D` is not a perfect square. + It is better to call `diop_DN` rather than this function, as + the former checks the condition `1 < N**2 < D`, and calls the latter only + if appropriate. + + Usage + ===== + + WARNING: Internal method. Do not call directly! + + ``_special_diop_DN(D, N)``: D and N are integers as in `x^2 - Dy^2 = N`. + + Details + ======= + + ``D`` and ``N`` correspond to D and N in the equation. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import _special_diop_DN + >>> _special_diop_DN(13, -3) # Solves equation x**2 - 13*y**2 = -3 + [(7, 2), (137, 38)] + + The output can be interpreted as follows: There are two fundamental + solutions to the equation `x^2 - 13y^2 = -3` given by (7, 2) and + (137, 38). Each tuple is in the form (x, y), i.e. solution (7, 2) means + that `x = 7` and `y = 2`. + + >>> _special_diop_DN(2445, -20) # Solves equation x**2 - 2445*y**2 = -20 + [(445, 9), (17625560, 356454), (698095554475, 14118073569)] + + See Also + ======== + + diop_DN() + + References + ========== + + .. [1] Section 4.4.4 of the following book: + Quadratic Diophantine Equations, T. Andreescu and D. Andrica, + Springer, 2015. + """ + + # The following assertion was removed for efficiency, with the understanding + # that this method is not called directly. The parent method, `diop_DN` + # is responsible for performing the appropriate checks. + # + # assert (1 < N**2 < D) and (not integer_nthroot(D, 2)[1]) + + sqrt_D = isqrt(D) + F = {N // f**2: f for f in divisors(square_factor(abs(N)), generator=True)} + P = 0 + Q = 1 + G0, G1 = 0, 1 + B0, B1 = 1, 0 + + solutions = [] + while True: + for _ in range(2): + a = (P + sqrt_D) // Q + P = a*Q - P + Q = (D - P**2) // Q + G0, G1 = G1, a*G1 + G0 + B0, B1 = B1, a*B1 + B0 + if (s := G1**2 - D*B1**2) in F: + f = F[s] + solutions.append((f*G1, f*B1)) + if Q == 1: + break + return solutions + + +def cornacchia(a:int, b:int, m:int) -> set[tuple[int, int]]: + r""" + Solves `ax^2 + by^2 = m` where `\gcd(a, b) = 1 = gcd(a, m)` and `a, b > 0`. + + Explanation + =========== + + Uses the algorithm due to Cornacchia. The method only finds primitive + solutions, i.e. ones with `\gcd(x, y) = 1`. So this method cannot be used to + find the solutions of `x^2 + y^2 = 20` since the only solution to former is + `(x, y) = (4, 2)` and it is not primitive. When `a = b`, only the + solutions with `x \leq y` are found. For more details, see the References. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import cornacchia + >>> cornacchia(2, 3, 35) # equation 2x**2 + 3y**2 = 35 + {(2, 3), (4, 1)} + >>> cornacchia(1, 1, 25) # equation x**2 + y**2 = 25 + {(4, 3)} + + References + =========== + + .. [1] A. Nitaj, "L'algorithme de Cornacchia" + .. [2] Solving the diophantine equation ax**2 + by**2 = m by Cornacchia's + method, [online], Available: + http://www.numbertheory.org/php/cornacchia.html + + See Also + ======== + + sympy.utilities.iterables.signed_permutations + """ + # Assume gcd(a, b) = gcd(a, m) = 1 and a, b > 0 but no error checking + sols = set() + + if a + b > m: + # xy = 0 must hold if there exists a solution + if a == 1: + # y = 0 + s, _exact = iroot(m // a, 2) + if _exact: + sols.add((int(s), 0)) + if a == b: + # only keep one solution + return sols + if m % b == 0: + # x = 0 + s, _exact = iroot(m // b, 2) + if _exact: + sols.add((0, int(s))) + return sols + + # the original cornacchia + for t in sqrt_mod_iter(-b*invert(a, m), m): + if t < m // 2: + continue + u, r = m, t + while (m1 := m - a*r**2) <= 0: + u, r = r, u % r + m1, _r = divmod(m1, b) + if _r: + continue + s, _exact = iroot(m1, 2) + if _exact: + if a == b and r < s: + r, s = s, r + sols.add((int(r), int(s))) + return sols + + +def PQa(P_0, Q_0, D): + r""" + Returns useful information needed to solve the Pell equation. + + Explanation + =========== + + There are six sequences of integers defined related to the continued + fraction representation of `\\frac{P + \sqrt{D}}{Q}`, namely {`P_{i}`}, + {`Q_{i}`}, {`a_{i}`},{`A_{i}`}, {`B_{i}`}, {`G_{i}`}. ``PQa()`` Returns + these values as a 6-tuple in the same order as mentioned above. Refer [1]_ + for more detailed information. + + Usage + ===== + + ``PQa(P_0, Q_0, D)``: ``P_0``, ``Q_0`` and ``D`` are integers corresponding + to `P_{0}`, `Q_{0}` and `D` in the continued fraction + `\\frac{P_{0} + \sqrt{D}}{Q_{0}}`. + Also it's assumed that `P_{0}^2 == D mod(|Q_{0}|)` and `D` is square free. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import PQa + >>> pqa = PQa(13, 4, 5) # (13 + sqrt(5))/4 + >>> next(pqa) # (P_0, Q_0, a_0, A_0, B_0, G_0) + (13, 4, 3, 3, 1, -1) + >>> next(pqa) # (P_1, Q_1, a_1, A_1, B_1, G_1) + (-1, 1, 1, 4, 1, 3) + + References + ========== + + .. [1] Solving the generalized Pell equation x^2 - Dy^2 = N, John P. + Robertson, July 31, 2004, Pages 4 - 8. https://web.archive.org/web/20160323033128/http://www.jpr2718.org/pell.pdf + """ + sqD = isqrt(D) + A2 = B1 = 0 + A1 = B2 = 1 + G1 = Q_0 + G2 = -P_0 + P_i = P_0 + Q_i = Q_0 + + while True: + a_i = (P_i + sqD) // Q_i + A1, A2 = a_i*A1 + A2, A1 + B1, B2 = a_i*B1 + B2, B1 + G1, G2 = a_i*G1 + G2, G1 + yield P_i, Q_i, a_i, A1, B1, G1 + + P_i = a_i*Q_i - P_i + Q_i = (D - P_i**2) // Q_i + + +def diop_bf_DN(D, N, t=symbols("t", integer=True)): + r""" + Uses brute force to solve the equation, `x^2 - Dy^2 = N`. + + Explanation + =========== + + Mainly concerned with the generalized Pell equation which is the case when + `D > 0, D` is not a perfect square. For more information on the case refer + [1]_. Let `(t, u)` be the minimal positive solution of the equation + `x^2 - Dy^2 = 1`. Then this method requires + `\sqrt{\\frac{\mid N \mid (t \pm 1)}{2D}}` to be small. + + Usage + ===== + + ``diop_bf_DN(D, N, t)``: ``D`` and ``N`` are coefficients in + `x^2 - Dy^2 = N` and ``t`` is the parameter to be used in the solutions. + + Details + ======= + + ``D`` and ``N`` correspond to D and N in the equation. + ``t`` is the parameter to be used in the solutions. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_bf_DN + >>> diop_bf_DN(13, -4) + [(3, 1), (-3, 1), (36, 10)] + >>> diop_bf_DN(986, 1) + [(49299, 1570)] + + See Also + ======== + + diop_DN() + + References + ========== + + .. [1] Solving the generalized Pell equation x**2 - D*y**2 = N, John P. + Robertson, July 31, 2004, Page 15. https://web.archive.org/web/20160323033128/http://www.jpr2718.org/pell.pdf + """ + D = as_int(D) + N = as_int(N) + + sol = [] + a = diop_DN(D, 1) + u = a[0][0] + + if N == 0: + if D < 0: + return [(0, 0)] + if D == 0: + return [(0, t)] + sD, _exact = integer_nthroot(D, 2) + if _exact: + return [(sD*t, t), (-sD*t, t)] + return [(0, 0)] + + if abs(N) == 1: + return diop_DN(D, N) + + if N > 1: + L1 = 0 + L2 = integer_nthroot(int(N*(u - 1)/(2*D)), 2)[0] + 1 + else: # N < -1 + L1, _exact = integer_nthroot(-int(N/D), 2) + if not _exact: + L1 += 1 + L2 = integer_nthroot(-int(N*(u + 1)/(2*D)), 2)[0] + 1 + + for y in range(L1, L2): + try: + x, _exact = integer_nthroot(N + D*y**2, 2) + except ValueError: + _exact = False + if _exact: + sol.append((x, y)) + if not equivalent(x, y, -x, y, D, N): + sol.append((-x, y)) + + return sol + + +def equivalent(u, v, r, s, D, N): + """ + Returns True if two solutions `(u, v)` and `(r, s)` of `x^2 - Dy^2 = N` + belongs to the same equivalence class and False otherwise. + + Explanation + =========== + + Two solutions `(u, v)` and `(r, s)` to the above equation fall to the same + equivalence class iff both `(ur - Dvs)` and `(us - vr)` are divisible by + `N`. See reference [1]_. No test is performed to test whether `(u, v)` and + `(r, s)` are actually solutions to the equation. User should take care of + this. + + Usage + ===== + + ``equivalent(u, v, r, s, D, N)``: `(u, v)` and `(r, s)` are two solutions + of the equation `x^2 - Dy^2 = N` and all parameters involved are integers. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import equivalent + >>> equivalent(18, 5, -18, -5, 13, -1) + True + >>> equivalent(3, 1, -18, 393, 109, -4) + False + + References + ========== + + .. [1] Solving the generalized Pell equation x**2 - D*y**2 = N, John P. + Robertson, July 31, 2004, Page 12. https://web.archive.org/web/20160323033128/http://www.jpr2718.org/pell.pdf + + """ + return divisible(u*r - D*v*s, N) and divisible(u*s - v*r, N) + + +def length(P, Q, D): + r""" + Returns the (length of aperiodic part + length of periodic part) of + continued fraction representation of `\\frac{P + \sqrt{D}}{Q}`. + + It is important to remember that this does NOT return the length of the + periodic part but the sum of the lengths of the two parts as mentioned + above. + + Usage + ===== + + ``length(P, Q, D)``: ``P``, ``Q`` and ``D`` are integers corresponding to + the continued fraction `\\frac{P + \sqrt{D}}{Q}`. + + Details + ======= + + ``P``, ``D`` and ``Q`` corresponds to P, D and Q in the continued fraction, + `\\frac{P + \sqrt{D}}{Q}`. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import length + >>> length(-2, 4, 5) # (-2 + sqrt(5))/4 + 3 + >>> length(-5, 4, 17) # (-5 + sqrt(17))/4 + 4 + + See Also + ======== + sympy.ntheory.continued_fraction.continued_fraction_periodic + """ + from sympy.ntheory.continued_fraction import continued_fraction_periodic + v = continued_fraction_periodic(P, Q, D) + if isinstance(v[-1], list): + rpt = len(v[-1]) + nonrpt = len(v) - 1 + else: + rpt = 0 + nonrpt = len(v) + return rpt + nonrpt + + +def transformation_to_DN(eq): + """ + This function transforms general quadratic, + `ax^2 + bxy + cy^2 + dx + ey + f = 0` + to more easy to deal with `X^2 - DY^2 = N` form. + + Explanation + =========== + + This is used to solve the general quadratic equation by transforming it to + the latter form. Refer to [1]_ for more detailed information on the + transformation. This function returns a tuple (A, B) where A is a 2 X 2 + matrix and B is a 2 X 1 matrix such that, + + Transpose([x y]) = A * Transpose([X Y]) + B + + Usage + ===== + + ``transformation_to_DN(eq)``: where ``eq`` is the quadratic to be + transformed. + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy.solvers.diophantine.diophantine import transformation_to_DN + >>> A, B = transformation_to_DN(x**2 - 3*x*y - y**2 - 2*y + 1) + >>> A + Matrix([ + [1/26, 3/26], + [ 0, 1/13]]) + >>> B + Matrix([ + [-6/13], + [-4/13]]) + + A, B returned are such that Transpose((x y)) = A * Transpose((X Y)) + B. + Substituting these values for `x` and `y` and a bit of simplifying work + will give an equation of the form `x^2 - Dy^2 = N`. + + >>> from sympy.abc import X, Y + >>> from sympy import Matrix, simplify + >>> u = (A*Matrix([X, Y]) + B)[0] # Transformation for x + >>> u + X/26 + 3*Y/26 - 6/13 + >>> v = (A*Matrix([X, Y]) + B)[1] # Transformation for y + >>> v + Y/13 - 4/13 + + Next we will substitute these formulas for `x` and `y` and do + ``simplify()``. + + >>> eq = simplify((x**2 - 3*x*y - y**2 - 2*y + 1).subs(zip((x, y), (u, v)))) + >>> eq + X**2/676 - Y**2/52 + 17/13 + + By multiplying the denominator appropriately, we can get a Pell equation + in the standard form. + + >>> eq * 676 + X**2 - 13*Y**2 + 884 + + If only the final equation is needed, ``find_DN()`` can be used. + + See Also + ======== + + find_DN() + + References + ========== + + .. [1] Solving the equation ax^2 + bxy + cy^2 + dx + ey + f = 0, + John P.Robertson, May 8, 2003, Page 7 - 11. + https://web.archive.org/web/20160323033111/http://www.jpr2718.org/ax2p.pdf + """ + + var, coeff, diop_type = classify_diop(eq, _dict=False) + if diop_type == BinaryQuadratic.name: + return _transformation_to_DN(var, coeff) + + +def _transformation_to_DN(var, coeff): + + x, y = var + + a = coeff[x**2] + b = coeff[x*y] + c = coeff[y**2] + d = coeff[x] + e = coeff[y] + f = coeff[1] + + a, b, c, d, e, f = [as_int(i) for i in _remove_gcd(a, b, c, d, e, f)] + + X, Y = symbols("X, Y", integer=True) + + if b: + B, C = _rational_pq(2*a, b) + A, T = _rational_pq(a, B**2) + + # eq_1 = A*B*X**2 + B*(c*T - A*C**2)*Y**2 + d*T*X + (B*e*T - d*T*C)*Y + f*T*B + coeff = {X**2: A*B, X*Y: 0, Y**2: B*(c*T - A*C**2), X: d*T, Y: B*e*T - d*T*C, 1: f*T*B} + A_0, B_0 = _transformation_to_DN([X, Y], coeff) + return Matrix(2, 2, [S.One/B, -S(C)/B, 0, 1])*A_0, Matrix(2, 2, [S.One/B, -S(C)/B, 0, 1])*B_0 + + if d: + B, C = _rational_pq(2*a, d) + A, T = _rational_pq(a, B**2) + + # eq_2 = A*X**2 + c*T*Y**2 + e*T*Y + f*T - A*C**2 + coeff = {X**2: A, X*Y: 0, Y**2: c*T, X: 0, Y: e*T, 1: f*T - A*C**2} + A_0, B_0 = _transformation_to_DN([X, Y], coeff) + return Matrix(2, 2, [S.One/B, 0, 0, 1])*A_0, Matrix(2, 2, [S.One/B, 0, 0, 1])*B_0 + Matrix([-S(C)/B, 0]) + + if e: + B, C = _rational_pq(2*c, e) + A, T = _rational_pq(c, B**2) + + # eq_3 = a*T*X**2 + A*Y**2 + f*T - A*C**2 + coeff = {X**2: a*T, X*Y: 0, Y**2: A, X: 0, Y: 0, 1: f*T - A*C**2} + A_0, B_0 = _transformation_to_DN([X, Y], coeff) + return Matrix(2, 2, [1, 0, 0, S.One/B])*A_0, Matrix(2, 2, [1, 0, 0, S.One/B])*B_0 + Matrix([0, -S(C)/B]) + + # TODO: pre-simplification: Not necessary but may simplify + # the equation. + return Matrix(2, 2, [S.One/a, 0, 0, 1]), Matrix([0, 0]) + + +def find_DN(eq): + """ + This function returns a tuple, `(D, N)` of the simplified form, + `x^2 - Dy^2 = N`, corresponding to the general quadratic, + `ax^2 + bxy + cy^2 + dx + ey + f = 0`. + + Solving the general quadratic is then equivalent to solving the equation + `X^2 - DY^2 = N` and transforming the solutions by using the transformation + matrices returned by ``transformation_to_DN()``. + + Usage + ===== + + ``find_DN(eq)``: where ``eq`` is the quadratic to be transformed. + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy.solvers.diophantine.diophantine import find_DN + >>> find_DN(x**2 - 3*x*y - y**2 - 2*y + 1) + (13, -884) + + Interpretation of the output is that we get `X^2 -13Y^2 = -884` after + transforming `x^2 - 3xy - y^2 - 2y + 1` using the transformation returned + by ``transformation_to_DN()``. + + See Also + ======== + + transformation_to_DN() + + References + ========== + + .. [1] Solving the equation ax^2 + bxy + cy^2 + dx + ey + f = 0, + John P.Robertson, May 8, 2003, Page 7 - 11. + https://web.archive.org/web/20160323033111/http://www.jpr2718.org/ax2p.pdf + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + if diop_type == BinaryQuadratic.name: + return _find_DN(var, coeff) + + +def _find_DN(var, coeff): + + x, y = var + X, Y = symbols("X, Y", integer=True) + A, B = _transformation_to_DN(var, coeff) + + u = (A*Matrix([X, Y]) + B)[0] + v = (A*Matrix([X, Y]) + B)[1] + eq = x**2*coeff[x**2] + x*y*coeff[x*y] + y**2*coeff[y**2] + x*coeff[x] + y*coeff[y] + coeff[1] + + simplified = _mexpand(eq.subs(zip((x, y), (u, v)))) + + coeff = simplified.as_coefficients_dict() + + return -coeff[Y**2]/coeff[X**2], -coeff[1]/coeff[X**2] + + +def check_param(x, y, a, params): + """ + If there is a number modulo ``a`` such that ``x`` and ``y`` are both + integers, then return a parametric representation for ``x`` and ``y`` + else return (None, None). + + Here ``x`` and ``y`` are functions of ``t``. + """ + from sympy.simplify.simplify import clear_coefficients + + if x.is_number and not x.is_Integer: + return DiophantineSolutionSet([x, y], parameters=params) + + if y.is_number and not y.is_Integer: + return DiophantineSolutionSet([x, y], parameters=params) + + m, n = symbols("m, n", integer=True) + c, p = (m*x + n*y).as_content_primitive() + if a % c.q: + return DiophantineSolutionSet([x, y], parameters=params) + + # clear_coefficients(mx + b, R)[1] -> (R - b)/m + eq = clear_coefficients(x, m)[1] - clear_coefficients(y, n)[1] + junk, eq = eq.as_content_primitive() + + return _diop_solve(eq, params=params) + + +def diop_ternary_quadratic(eq, parameterize=False): + """ + Solves the general quadratic ternary form, + `ax^2 + by^2 + cz^2 + fxy + gyz + hxz = 0`. + + Returns a tuple `(x, y, z)` which is a base solution for the above + equation. If there are no solutions, `(None, None, None)` is returned. + + Usage + ===== + + ``diop_ternary_quadratic(eq)``: Return a tuple containing a basic solution + to ``eq``. + + Details + ======= + + ``eq`` should be an homogeneous expression of degree two in three variables + and it is assumed to be zero. + + Examples + ======== + + >>> from sympy.abc import x, y, z + >>> from sympy.solvers.diophantine.diophantine import diop_ternary_quadratic + >>> diop_ternary_quadratic(x**2 + 3*y**2 - z**2) + (1, 0, 1) + >>> diop_ternary_quadratic(4*x**2 + 5*y**2 - z**2) + (1, 0, 2) + >>> diop_ternary_quadratic(45*x**2 - 7*y**2 - 8*x*y - z**2) + (28, 45, 105) + >>> diop_ternary_quadratic(x**2 - 49*y**2 - z**2 + 13*z*y -8*x*y) + (9, 1, 5) + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type in ( + HomogeneousTernaryQuadratic.name, + HomogeneousTernaryQuadraticNormal.name): + sol = _diop_ternary_quadratic(var, coeff) + if len(sol) > 0: + x_0, y_0, z_0 = list(sol)[0] + else: + x_0, y_0, z_0 = None, None, None + + if parameterize: + return _parametrize_ternary_quadratic( + (x_0, y_0, z_0), var, coeff) + return x_0, y_0, z_0 + + +def _diop_ternary_quadratic(_var, coeff): + eq = sum(i*coeff[i] for i in coeff) + if HomogeneousTernaryQuadratic(eq).matches(): + return HomogeneousTernaryQuadratic(eq, free_symbols=_var).solve() + elif HomogeneousTernaryQuadraticNormal(eq).matches(): + return HomogeneousTernaryQuadraticNormal(eq, free_symbols=_var).solve() + + +def transformation_to_normal(eq): + """ + Returns the transformation Matrix that converts a general ternary + quadratic equation ``eq`` (`ax^2 + by^2 + cz^2 + dxy + eyz + fxz`) + to a form without cross terms: `ax^2 + by^2 + cz^2 = 0`. This is + not used in solving ternary quadratics; it is only implemented for + the sake of completeness. + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type in ( + "homogeneous_ternary_quadratic", + "homogeneous_ternary_quadratic_normal"): + return _transformation_to_normal(var, coeff) + + +def _transformation_to_normal(var, coeff): + + _var = list(var) # copy + x, y, z = var + + if not any(coeff[i**2] for i in var): + # https://math.stackexchange.com/questions/448051/transform-quadratic-ternary-form-to-normal-form/448065#448065 + a = coeff[x*y] + b = coeff[y*z] + c = coeff[x*z] + swap = False + if not a: # b can't be 0 or else there aren't 3 vars + swap = True + a, b = b, a + T = Matrix(((1, 1, -b/a), (1, -1, -c/a), (0, 0, 1))) + if swap: + T.row_swap(0, 1) + T.col_swap(0, 1) + return T + + if coeff[x**2] == 0: + # If the coefficient of x is zero change the variables + if coeff[y**2] == 0: + _var[0], _var[2] = var[2], var[0] + T = _transformation_to_normal(_var, coeff) + T.row_swap(0, 2) + T.col_swap(0, 2) + return T + + _var[0], _var[1] = var[1], var[0] + T = _transformation_to_normal(_var, coeff) + T.row_swap(0, 1) + T.col_swap(0, 1) + return T + + # Apply the transformation x --> X - (B*Y + C*Z)/(2*A) + if coeff[x*y] != 0 or coeff[x*z] != 0: + A = coeff[x**2] + B = coeff[x*y] + C = coeff[x*z] + D = coeff[y**2] + E = coeff[y*z] + F = coeff[z**2] + + _coeff = {} + + _coeff[x**2] = 4*A**2 + _coeff[y**2] = 4*A*D - B**2 + _coeff[z**2] = 4*A*F - C**2 + _coeff[y*z] = 4*A*E - 2*B*C + _coeff[x*y] = 0 + _coeff[x*z] = 0 + + T_0 = _transformation_to_normal(_var, _coeff) + return Matrix(3, 3, [1, S(-B)/(2*A), S(-C)/(2*A), 0, 1, 0, 0, 0, 1])*T_0 + + elif coeff[y*z] != 0: + if coeff[y**2] == 0: + if coeff[z**2] == 0: + # Equations of the form A*x**2 + E*yz = 0. + # Apply transformation y -> Y + Z ans z -> Y - Z + return Matrix(3, 3, [1, 0, 0, 0, 1, 1, 0, 1, -1]) + + # Ax**2 + E*y*z + F*z**2 = 0 + _var[0], _var[2] = var[2], var[0] + T = _transformation_to_normal(_var, coeff) + T.row_swap(0, 2) + T.col_swap(0, 2) + return T + + # A*x**2 + D*y**2 + E*y*z + F*z**2 = 0, F may be zero + _var[0], _var[1] = var[1], var[0] + T = _transformation_to_normal(_var, coeff) + T.row_swap(0, 1) + T.col_swap(0, 1) + return T + + return Matrix.eye(3) + + +def parametrize_ternary_quadratic(eq): + """ + Returns the parametrized general solution for the ternary quadratic + equation ``eq`` which has the form + `ax^2 + by^2 + cz^2 + fxy + gyz + hxz = 0`. + + Examples + ======== + + >>> from sympy import Tuple, ordered + >>> from sympy.abc import x, y, z + >>> from sympy.solvers.diophantine.diophantine import parametrize_ternary_quadratic + + The parametrized solution may be returned with three parameters: + + >>> parametrize_ternary_quadratic(2*x**2 + y**2 - 2*z**2) + (p**2 - 2*q**2, -2*p**2 + 4*p*q - 4*p*r - 4*q**2, p**2 - 4*p*q + 2*q**2 - 4*q*r) + + There might also be only two parameters: + + >>> parametrize_ternary_quadratic(4*x**2 + 2*y**2 - 3*z**2) + (2*p**2 - 3*q**2, -4*p**2 + 12*p*q - 6*q**2, 4*p**2 - 8*p*q + 6*q**2) + + Notes + ===== + + Consider ``p`` and ``q`` in the previous 2-parameter + solution and observe that more than one solution can be represented + by a given pair of parameters. If `p` and ``q`` are not coprime, this is + trivially true since the common factor will also be a common factor of the + solution values. But it may also be true even when ``p`` and + ``q`` are coprime: + + >>> sol = Tuple(*_) + >>> p, q = ordered(sol.free_symbols) + >>> sol.subs([(p, 3), (q, 2)]) + (6, 12, 12) + >>> sol.subs([(q, 1), (p, 1)]) + (-1, 2, 2) + >>> sol.subs([(q, 0), (p, 1)]) + (2, -4, 4) + >>> sol.subs([(q, 1), (p, 0)]) + (-3, -6, 6) + + Except for sign and a common factor, these are equivalent to + the solution of (1, 2, 2). + + References + ========== + + .. [1] The algorithmic resolution of Diophantine equations, Nigel P. Smart, + London Mathematical Society Student Texts 41, Cambridge University + Press, Cambridge, 1998. + + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type in ( + "homogeneous_ternary_quadratic", + "homogeneous_ternary_quadratic_normal"): + x_0, y_0, z_0 = list(_diop_ternary_quadratic(var, coeff))[0] + return _parametrize_ternary_quadratic( + (x_0, y_0, z_0), var, coeff) + + +def _parametrize_ternary_quadratic(solution, _var, coeff): + # called for a*x**2 + b*y**2 + c*z**2 + d*x*y + e*y*z + f*x*z = 0 + assert 1 not in coeff + + x_0, y_0, z_0 = solution + + v = list(_var) # copy + + if x_0 is None: + return (None, None, None) + + if solution.count(0) >= 2: + # if there are 2 zeros the equation reduces + # to k*X**2 == 0 where X is x, y, or z so X must + # be zero, too. So there is only the trivial + # solution. + return (None, None, None) + + if x_0 == 0: + v[0], v[1] = v[1], v[0] + y_p, x_p, z_p = _parametrize_ternary_quadratic( + (y_0, x_0, z_0), v, coeff) + return x_p, y_p, z_p + + x, y, z = v + r, p, q = symbols("r, p, q", integer=True) + + eq = sum(k*v for k, v in coeff.items()) + eq_1 = _mexpand(eq.subs(zip( + (x, y, z), (r*x_0, r*y_0 + p, r*z_0 + q)))) + A, B = eq_1.as_independent(r, as_Add=True) + + + x = A*x_0 + y = (A*y_0 - _mexpand(B/r*p)) + z = (A*z_0 - _mexpand(B/r*q)) + + return _remove_gcd(x, y, z) + + +def diop_ternary_quadratic_normal(eq, parameterize=False): + """ + Solves the quadratic ternary diophantine equation, + `ax^2 + by^2 + cz^2 = 0`. + + Explanation + =========== + + Here the coefficients `a`, `b`, and `c` should be non zero. Otherwise the + equation will be a quadratic binary or univariate equation. If solvable, + returns a tuple `(x, y, z)` that satisfies the given equation. If the + equation does not have integer solutions, `(None, None, None)` is returned. + + Usage + ===== + + ``diop_ternary_quadratic_normal(eq)``: where ``eq`` is an equation of the form + `ax^2 + by^2 + cz^2 = 0`. + + Examples + ======== + + >>> from sympy.abc import x, y, z + >>> from sympy.solvers.diophantine.diophantine import diop_ternary_quadratic_normal + >>> diop_ternary_quadratic_normal(x**2 + 3*y**2 - z**2) + (1, 0, 1) + >>> diop_ternary_quadratic_normal(4*x**2 + 5*y**2 - z**2) + (1, 0, 2) + >>> diop_ternary_quadratic_normal(34*x**2 - 3*y**2 - 301*z**2) + (4, 9, 1) + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + if diop_type == HomogeneousTernaryQuadraticNormal.name: + sol = _diop_ternary_quadratic_normal(var, coeff) + if len(sol) > 0: + x_0, y_0, z_0 = list(sol)[0] + else: + x_0, y_0, z_0 = None, None, None + if parameterize: + return _parametrize_ternary_quadratic( + (x_0, y_0, z_0), var, coeff) + return x_0, y_0, z_0 + + +def _diop_ternary_quadratic_normal(var, coeff): + eq = sum(i * coeff[i] for i in coeff) + return HomogeneousTernaryQuadraticNormal(eq, free_symbols=var).solve() + + +def sqf_normal(a, b, c, steps=False): + """ + Return `a', b', c'`, the coefficients of the square-free normal + form of `ax^2 + by^2 + cz^2 = 0`, where `a', b', c'` are pairwise + prime. If `steps` is True then also return three tuples: + `sq`, `sqf`, and `(a', b', c')` where `sq` contains the square + factors of `a`, `b` and `c` after removing the `gcd(a, b, c)`; + `sqf` contains the values of `a`, `b` and `c` after removing + both the `gcd(a, b, c)` and the square factors. + + The solutions for `ax^2 + by^2 + cz^2 = 0` can be + recovered from the solutions of `a'x^2 + b'y^2 + c'z^2 = 0`. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import sqf_normal + >>> sqf_normal(2 * 3**2 * 5, 2 * 5 * 11, 2 * 7**2 * 11) + (11, 1, 5) + >>> sqf_normal(2 * 3**2 * 5, 2 * 5 * 11, 2 * 7**2 * 11, True) + ((3, 1, 7), (5, 55, 11), (11, 1, 5)) + + References + ========== + + .. [1] Legendre's Theorem, Legrange's Descent, + https://public.csusm.edu/aitken_html/notes/legendre.pdf + + + See Also + ======== + + reconstruct() + """ + ABC = _remove_gcd(a, b, c) + sq = tuple(square_factor(i) for i in ABC) + sqf = A, B, C = tuple([i//j**2 for i,j in zip(ABC, sq)]) + pc = igcd(A, B) + A /= pc + B /= pc + pa = igcd(B, C) + B /= pa + C /= pa + pb = igcd(A, C) + A /= pb + B /= pb + + A *= pa + B *= pb + C *= pc + + if steps: + return (sq, sqf, (A, B, C)) + else: + return A, B, C + + +def square_factor(a): + r""" + Returns an integer `c` s.t. `a = c^2k, \ c,k \in Z`. Here `k` is square + free. `a` can be given as an integer or a dictionary of factors. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import square_factor + >>> square_factor(24) + 2 + >>> square_factor(-36*3) + 6 + >>> square_factor(1) + 1 + >>> square_factor({3: 2, 2: 1, -1: 1}) # -18 + 3 + + See Also + ======== + sympy.ntheory.factor_.core + """ + f = a if isinstance(a, dict) else factorint(a) + return Mul(*[p**(e//2) for p, e in f.items()]) + + +def reconstruct(A, B, z): + """ + Reconstruct the `z` value of an equivalent solution of `ax^2 + by^2 + cz^2` + from the `z` value of a solution of the square-free normal form of the + equation, `a'*x^2 + b'*y^2 + c'*z^2`, where `a'`, `b'` and `c'` are square + free and `gcd(a', b', c') == 1`. + """ + f = factorint(igcd(A, B)) + for p, e in f.items(): + if e != 1: + raise ValueError('a and b should be square-free') + z *= p + return z + + +def ldescent(A, B): + """ + Return a non-trivial solution to `w^2 = Ax^2 + By^2` using + Lagrange's method; return None if there is no such solution. + + Parameters + ========== + + A : Integer + B : Integer + non-zero integer + + Returns + ======= + + (int, int, int) | None : a tuple `(w_0, x_0, y_0)` which is a solution to the above equation. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import ldescent + >>> ldescent(1, 1) # w^2 = x^2 + y^2 + (1, 1, 0) + >>> ldescent(4, -7) # w^2 = 4x^2 - 7y^2 + (2, -1, 0) + + This means that `x = -1, y = 0` and `w = 2` is a solution to the equation + `w^2 = 4x^2 - 7y^2` + + >>> ldescent(5, -1) # w^2 = 5x^2 - y^2 + (2, 1, -1) + + References + ========== + + .. [1] The algorithmic resolution of Diophantine equations, Nigel P. Smart, + London Mathematical Society Student Texts 41, Cambridge University + Press, Cambridge, 1998. + .. [2] Cremona, J. E., Rusin, D. (2003). Efficient Solution of Rational Conics. + Mathematics of Computation, 72(243), 1417-1441. + https://doi.org/10.1090/S0025-5718-02-01480-1 + """ + if A == 0 or B == 0: + raise ValueError("A and B must be non-zero integers") + if abs(A) > abs(B): + w, y, x = ldescent(B, A) + return w, x, y + if A == 1: + return (1, 1, 0) + if B == 1: + return (1, 0, 1) + if B == -1: # and A == -1 + return + + r = sqrt_mod(A, B) + if r is None: + return + Q = (r**2 - A) // B + if Q == 0: + return r, -1, 0 + for i in divisors(Q): + d, _exact = integer_nthroot(abs(Q) // i, 2) + if _exact: + B_0 = sign(Q)*i + W, X, Y = ldescent(A, B_0) + return _remove_gcd(-A*X + r*W, r*X - W, Y*B_0*d) + + +def descent(A, B): + """ + Returns a non-trivial solution, (x, y, z), to `x^2 = Ay^2 + Bz^2` + using Lagrange's descent method with lattice-reduction. `A` and `B` + are assumed to be valid for such a solution to exist. + + This is faster than the normal Lagrange's descent algorithm because + the Gaussian reduction is used. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import descent + >>> descent(3, 1) # x**2 = 3*y**2 + z**2 + (1, 0, 1) + + `(x, y, z) = (1, 0, 1)` is a solution to the above equation. + + >>> descent(41, -113) + (-16, -3, 1) + + References + ========== + + .. [1] Cremona, J. E., Rusin, D. (2003). Efficient Solution of Rational Conics. + Mathematics of Computation, 72(243), 1417-1441. + https://doi.org/10.1090/S0025-5718-02-01480-1 + """ + if abs(A) > abs(B): + x, y, z = descent(B, A) + return x, z, y + + if B == 1: + return (1, 0, 1) + if A == 1: + return (1, 1, 0) + if B == -A: + return (0, 1, 1) + if B == A: + x, z, y = descent(-1, A) + return (A*y, z, x) + + w = sqrt_mod(A, B) + x_0, z_0 = gaussian_reduce(w, A, B) + + t = (x_0**2 - A*z_0**2) // B + t_2 = square_factor(t) + t_1 = t // t_2**2 + + x_1, z_1, y_1 = descent(A, t_1) + + return _remove_gcd(x_0*x_1 + A*z_0*z_1, z_0*x_1 + x_0*z_1, t_1*t_2*y_1) + + +def gaussian_reduce(w:int, a:int, b:int) -> tuple[int, int]: + r""" + Returns a reduced solution `(x, z)` to the congruence + `X^2 - aZ^2 \equiv 0 \pmod{b}` so that `x^2 + |a|z^2` is as small as possible. + Here ``w`` is a solution of the congruence `x^2 \equiv a \pmod{b}`. + + This function is intended to be used only for ``descent()``. + + Explanation + =========== + + The Gaussian reduction can find the shortest vector for any norm. + So we define the special norm for the vectors `u = (u_1, u_2)` and `v = (v_1, v_2)` as follows. + + .. math :: + u \cdot v := (wu_1 + bu_2)(wv_1 + bv_2) + |a|u_1v_1 + + Note that, given the mapping `f: (u_1, u_2) \to (wu_1 + bu_2, u_1)`, + `f((u_1,u_2))` is the solution to `X^2 - aZ^2 \equiv 0 \pmod{b}`. + In other words, finding the shortest vector in this norm will yield a solution with smaller `X^2 + |a|Z^2`. + The algorithm starts from basis vectors `(0, 1)` and `(1, 0)` + (corresponding to solutions `(b, 0)` and `(w, 1)`, respectively) and finds the shortest vector. + The shortest vector does not necessarily correspond to the smallest solution, + but since ``descent()`` only wants the smallest possible solution, it is sufficient. + + Parameters + ========== + + w : int + ``w`` s.t. `w^2 \equiv a \pmod{b}` + a : int + square-free nonzero integer + b : int + square-free nonzero integer + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import gaussian_reduce + >>> from sympy.ntheory.residue_ntheory import sqrt_mod + >>> a, b = 19, 101 + >>> gaussian_reduce(sqrt_mod(a, b), a, b) # 1**2 - 19*(-4)**2 = -303 + (1, -4) + >>> a, b = 11, 14 + >>> x, z = gaussian_reduce(sqrt_mod(a, b), a, b) + >>> (x**2 - a*z**2) % b == 0 + True + + It does not always return the smallest solution. + + >>> a, b = 6, 95 + >>> min_x, min_z = 1, 4 + >>> x, z = gaussian_reduce(sqrt_mod(a, b), a, b) + >>> (x**2 - a*z**2) % b == 0 and (min_x**2 - a*min_z**2) % b == 0 + True + >>> min_x**2 + abs(a)*min_z**2 < x**2 + abs(a)*z**2 + True + + References + ========== + + .. [1] Gaussian lattice Reduction [online]. Available: + https://web.archive.org/web/20201021115213/http://home.ie.cuhk.edu.hk/~wkshum/wordpress/?p=404 + .. [2] Cremona, J. E., Rusin, D. (2003). Efficient Solution of Rational Conics. + Mathematics of Computation, 72(243), 1417-1441. + https://doi.org/10.1090/S0025-5718-02-01480-1 + """ + a = abs(a) + def _dot(u, v): + return u[0]*v[0] + a*u[1]*v[1] + + u = (b, 0) + v = (w, 1) if b*w >= 0 else (-w, -1) + # i.e., _dot(u, v) >= 0 + + if b**2 < w**2 + a: + u, v = v, u + # i.e., norm(u) >= norm(v), where norm(u) := sqrt(_dot(u, u)) + + while _dot(u, u) > (dv := _dot(v, v)): + k = _dot(u, v) // dv + u, v = v, (u[0] - k*v[0], u[1] - k*v[1]) + c = (v[0] - u[0], v[1] - u[1]) + if _dot(c, c) <= _dot(u, u) <= 2*_dot(u, v): + return c + return u + + +def holzer(x, y, z, a, b, c): + r""" + Simplify the solution `(x, y, z)` of the equation + `ax^2 + by^2 = cz^2` with `a, b, c > 0` and `z^2 \geq \mid ab \mid` to + a new reduced solution `(x', y', z')` such that `z'^2 \leq \mid ab \mid`. + + The algorithm is an interpretation of Mordell's reduction as described + on page 8 of Cremona and Rusin's paper [1]_ and the work of Mordell in + reference [2]_. + + References + ========== + + .. [1] Cremona, J. E., Rusin, D. (2003). Efficient Solution of Rational Conics. + Mathematics of Computation, 72(243), 1417-1441. + https://doi.org/10.1090/S0025-5718-02-01480-1 + .. [2] Diophantine Equations, L. J. Mordell, page 48. + + """ + + if _odd(c): + k = 2*c + else: + k = c//2 + + small = a*b*c + step = 0 + while True: + t1, t2, t3 = a*x**2, b*y**2, c*z**2 + # check that it's a solution + if t1 + t2 != t3: + if step == 0: + raise ValueError('bad starting solution') + break + x_0, y_0, z_0 = x, y, z + if max(t1, t2, t3) <= small: + # Holzer condition + break + + uv = u, v = base_solution_linear(k, y_0, -x_0) + if None in uv: + break + + p, q = -(a*u*x_0 + b*v*y_0), c*z_0 + r = Rational(p, q) + if _even(c): + w = _nint_or_floor(p, q) + assert abs(w - r) <= S.Half + else: + w = p//q # floor + if _odd(a*u + b*v + c*w): + w += 1 + assert abs(w - r) <= S.One + + A = (a*u**2 + b*v**2 + c*w**2) + B = (a*u*x_0 + b*v*y_0 + c*w*z_0) + x = Rational(x_0*A - 2*u*B, k) + y = Rational(y_0*A - 2*v*B, k) + z = Rational(z_0*A - 2*w*B, k) + assert all(i.is_Integer for i in (x, y, z)) + step += 1 + + return tuple([int(i) for i in (x_0, y_0, z_0)]) + + +def diop_general_pythagorean(eq, param=symbols("m", integer=True)): + """ + Solves the general pythagorean equation, + `a_{1}^2x_{1}^2 + a_{2}^2x_{2}^2 + . . . + a_{n}^2x_{n}^2 - a_{n + 1}^2x_{n + 1}^2 = 0`. + + Returns a tuple which contains a parametrized solution to the equation, + sorted in the same order as the input variables. + + Usage + ===== + + ``diop_general_pythagorean(eq, param)``: where ``eq`` is a general + pythagorean equation which is assumed to be zero and ``param`` is the base + parameter used to construct other parameters by subscripting. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_general_pythagorean + >>> from sympy.abc import a, b, c, d, e + >>> diop_general_pythagorean(a**2 + b**2 + c**2 - d**2) + (m1**2 + m2**2 - m3**2, 2*m1*m3, 2*m2*m3, m1**2 + m2**2 + m3**2) + >>> diop_general_pythagorean(9*a**2 - 4*b**2 + 16*c**2 + 25*d**2 + e**2) + (10*m1**2 + 10*m2**2 + 10*m3**2 - 10*m4**2, 15*m1**2 + 15*m2**2 + 15*m3**2 + 15*m4**2, 15*m1*m4, 12*m2*m4, 60*m3*m4) + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type == GeneralPythagorean.name: + if param is None: + params = None + else: + params = symbols('%s1:%i' % (param, len(var)), integer=True) + return list(GeneralPythagorean(eq).solve(parameters=params))[0] + + +def diop_general_sum_of_squares(eq, limit=1): + r""" + Solves the equation `x_{1}^2 + x_{2}^2 + . . . + x_{n}^2 - k = 0`. + + Returns at most ``limit`` number of solutions. + + Usage + ===== + + ``general_sum_of_squares(eq, limit)`` : Here ``eq`` is an expression which + is assumed to be zero. Also, ``eq`` should be in the form, + `x_{1}^2 + x_{2}^2 + . . . + x_{n}^2 - k = 0`. + + Details + ======= + + When `n = 3` if `k = 4^a(8m + 7)` for some `a, m \in Z` then there will be + no solutions. Refer to [1]_ for more details. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_general_sum_of_squares + >>> from sympy.abc import a, b, c, d, e + >>> diop_general_sum_of_squares(a**2 + b**2 + c**2 + d**2 + e**2 - 2345) + {(15, 22, 22, 24, 24)} + + Reference + ========= + + .. [1] Representing an integer as a sum of three squares, [online], + Available: + https://proofwiki.org/wiki/Integer_as_Sum_of_Three_Squares + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type == GeneralSumOfSquares.name: + return set(GeneralSumOfSquares(eq).solve(limit=limit)) + + +def diop_general_sum_of_even_powers(eq, limit=1): + """ + Solves the equation `x_{1}^e + x_{2}^e + . . . + x_{n}^e - k = 0` + where `e` is an even, integer power. + + Returns at most ``limit`` number of solutions. + + Usage + ===== + + ``general_sum_of_even_powers(eq, limit)`` : Here ``eq`` is an expression which + is assumed to be zero. Also, ``eq`` should be in the form, + `x_{1}^e + x_{2}^e + . . . + x_{n}^e - k = 0`. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import diop_general_sum_of_even_powers + >>> from sympy.abc import a, b + >>> diop_general_sum_of_even_powers(a**4 + b**4 - (2**4 + 3**4)) + {(2, 3)} + + See Also + ======== + + power_representation + """ + var, coeff, diop_type = classify_diop(eq, _dict=False) + + if diop_type == GeneralSumOfEvenPowers.name: + return set(GeneralSumOfEvenPowers(eq).solve(limit=limit)) + + +## Functions below this comment can be more suitably grouped under +## an Additive number theory module rather than the Diophantine +## equation module. + + +def partition(n, k=None, zeros=False): + """ + Returns a generator that can be used to generate partitions of an integer + `n`. + + Explanation + =========== + + A partition of `n` is a set of positive integers which add up to `n`. For + example, partitions of 3 are 3, 1 + 2, 1 + 1 + 1. A partition is returned + as a tuple. If ``k`` equals None, then all possible partitions are returned + irrespective of their size, otherwise only the partitions of size ``k`` are + returned. If the ``zero`` parameter is set to True then a suitable + number of zeros are added at the end of every partition of size less than + ``k``. + + ``zero`` parameter is considered only if ``k`` is not None. When the + partitions are over, the last `next()` call throws the ``StopIteration`` + exception, so this function should always be used inside a try - except + block. + + Details + ======= + + ``partition(n, k)``: Here ``n`` is a positive integer and ``k`` is the size + of the partition which is also positive integer. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import partition + >>> f = partition(5) + >>> next(f) + (1, 1, 1, 1, 1) + >>> next(f) + (1, 1, 1, 2) + >>> g = partition(5, 3) + >>> next(g) + (1, 1, 3) + >>> next(g) + (1, 2, 2) + >>> g = partition(5, 3, zeros=True) + >>> next(g) + (0, 0, 5) + + """ + if not zeros or k is None: + for i in ordered_partitions(n, k): + yield tuple(i) + else: + for m in range(1, k + 1): + for i in ordered_partitions(n, m): + i = tuple(i) + yield (0,)*(k - len(i)) + i + + +def prime_as_sum_of_two_squares(p): + """ + Represent a prime `p` as a unique sum of two squares; this can + only be done if the prime is congruent to 1 mod 4. + + Parameters + ========== + + p : Integer + A prime that is congruent to 1 mod 4 + + Returns + ======= + + (int, int) | None : Pair of positive integers ``(x, y)`` satisfying ``x**2 + y**2 = p``. + None if ``p`` is not congruent to 1 mod 4. + + Raises + ====== + + ValueError + If ``p`` is not prime number + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import prime_as_sum_of_two_squares + >>> prime_as_sum_of_two_squares(7) # can't be done + >>> prime_as_sum_of_two_squares(5) + (1, 2) + + Reference + ========= + + .. [1] Representing a number as a sum of four squares, [online], + Available: https://schorn.ch/lagrange.html + + See Also + ======== + + sum_of_squares + + """ + p = as_int(p) + if p % 4 != 1: + return + if not isprime(p): + raise ValueError("p should be a prime number") + + if p % 8 == 5: + # Legendre symbol (2/p) == -1 if p % 8 in [3, 5] + b = 2 + elif p % 12 == 5: + # Legendre symbol (3/p) == -1 if p % 12 in [5, 7] + b = 3 + elif p % 5 in [2, 3]: + # Legendre symbol (5/p) == -1 if p % 5 in [2, 3] + b = 5 + else: + b = 7 + while jacobi(b, p) == 1: + b = nextprime(b) + + b = pow(b, p >> 2, p) + a = p + while b**2 > p: + a, b = b, a % b + return (int(a % b), int(b)) # convert from long + + +def sum_of_three_squares(n): + r""" + Returns a 3-tuple $(a, b, c)$ such that $a^2 + b^2 + c^2 = n$ and + $a, b, c \geq 0$. + + Returns None if $n = 4^a(8m + 7)$ for some `a, m \in \mathbb{Z}`. See + [1]_ for more details. + + Parameters + ========== + + n : Integer + non-negative integer + + Returns + ======= + + (int, int, int) | None : 3-tuple non-negative integers ``(a, b, c)`` satisfying ``a**2 + b**2 + c**2 = n``. + a,b,c are sorted in ascending order. ``None`` if no such ``(a,b,c)``. + + Raises + ====== + + ValueError + If ``n`` is a negative integer + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import sum_of_three_squares + >>> sum_of_three_squares(44542) + (18, 37, 207) + + References + ========== + + .. [1] Representing a number as a sum of three squares, [online], + Available: https://schorn.ch/lagrange.html + + See Also + ======== + + power_representation : + ``sum_of_three_squares(n)`` is one of the solutions output by ``power_representation(n, 2, 3, zeros=True)`` + + """ + # https://math.stackexchange.com/questions/483101/rabin-and-shallit-algorithm/651425#651425 + # discusses these numbers (except for 1, 2, 3) as the exceptions of H&L's conjecture that + # Every sufficiently large number n is either a square or the sum of a prime and a square. + special = {1: (0, 0, 1), 2: (0, 1, 1), 3: (1, 1, 1), 10: (0, 1, 3), 34: (3, 3, 4), + 58: (0, 3, 7), 85: (0, 6, 7), 130: (0, 3, 11), 214: (3, 6, 13), 226: (8, 9, 9), + 370: (8, 9, 15), 526: (6, 7, 21), 706: (15, 15, 16), 730: (0, 1, 27), + 1414: (6, 17, 33), 1906: (13, 21, 36), 2986: (21, 32, 39), 9634: (56, 57, 57)} + n = as_int(n) + if n < 0: + raise ValueError("n should be a non-negative integer") + if n == 0: + return (0, 0, 0) + n, v = remove(n, 4) + v = 1 << v + if n % 8 == 7: + return + if n in special: + return tuple([v*i for i in special[n]]) + + s, _exact = integer_nthroot(n, 2) + if _exact: + return (0, 0, v*s) + if n % 8 == 3: + if not s % 2: + s -= 1 + for x in range(s, -1, -2): + N = (n - x**2) // 2 + if isprime(N): + # n % 8 == 3 and x % 2 == 1 => N % 4 == 1 + y, z = prime_as_sum_of_two_squares(N) + return tuple(sorted([v*x, v*(y + z), v*abs(y - z)])) + # We will never reach this point because there must be a solution. + assert False + + # assert n % 4 in [1, 2] + if not((n % 2) ^ (s % 2)): + s -= 1 + for x in range(s, -1, -2): + N = n - x**2 + if isprime(N): + # assert N % 4 == 1 + y, z = prime_as_sum_of_two_squares(N) + return tuple(sorted([v*x, v*y, v*z])) + # We will never reach this point because there must be a solution. + assert False + + +def sum_of_four_squares(n): + r""" + Returns a 4-tuple `(a, b, c, d)` such that `a^2 + b^2 + c^2 + d^2 = n`. + Here `a, b, c, d \geq 0`. + + Parameters + ========== + + n : Integer + non-negative integer + + Returns + ======= + + (int, int, int, int) : 4-tuple non-negative integers ``(a, b, c, d)`` satisfying ``a**2 + b**2 + c**2 + d**2 = n``. + a,b,c,d are sorted in ascending order. + + Raises + ====== + + ValueError + If ``n`` is a negative integer + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import sum_of_four_squares + >>> sum_of_four_squares(3456) + (8, 8, 32, 48) + >>> sum_of_four_squares(1294585930293) + (0, 1234, 2161, 1137796) + + References + ========== + + .. [1] Representing a number as a sum of four squares, [online], + Available: https://schorn.ch/lagrange.html + + See Also + ======== + + power_representation : + ``sum_of_four_squares(n)`` is one of the solutions output by ``power_representation(n, 2, 4, zeros=True)`` + + """ + n = as_int(n) + if n < 0: + raise ValueError("n should be a non-negative integer") + if n == 0: + return (0, 0, 0, 0) + # remove factors of 4 since a solution in terms of 3 squares is + # going to be returned; this is also done in sum_of_three_squares, + # but it needs to be done here to select d + n, v = remove(n, 4) + v = 1 << v + if n % 8 == 7: + d = 2 + n = n - 4 + elif n % 8 in (2, 6): + d = 1 + n = n - 1 + else: + d = 0 + x, y, z = sum_of_three_squares(n) # sorted + return tuple(sorted([v*d, v*x, v*y, v*z])) + + +def power_representation(n, p, k, zeros=False): + r""" + Returns a generator for finding k-tuples of integers, + `(n_{1}, n_{2}, . . . n_{k})`, such that + `n = n_{1}^p + n_{2}^p + . . . n_{k}^p`. + + Usage + ===== + + ``power_representation(n, p, k, zeros)``: Represent non-negative number + ``n`` as a sum of ``k`` ``p``\ th powers. If ``zeros`` is true, then the + solutions is allowed to contain zeros. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import power_representation + + Represent 1729 as a sum of two cubes: + + >>> f = power_representation(1729, 3, 2) + >>> next(f) + (9, 10) + >>> next(f) + (1, 12) + + If the flag `zeros` is True, the solution may contain tuples with + zeros; any such solutions will be generated after the solutions + without zeros: + + >>> list(power_representation(125, 2, 3, zeros=True)) + [(5, 6, 8), (3, 4, 10), (0, 5, 10), (0, 2, 11)] + + For even `p` the `permute_sign` function can be used to get all + signed values: + + >>> from sympy.utilities.iterables import permute_signs + >>> list(permute_signs((1, 12))) + [(1, 12), (-1, 12), (1, -12), (-1, -12)] + + All possible signed permutations can also be obtained: + + >>> from sympy.utilities.iterables import signed_permutations + >>> list(signed_permutations((1, 12))) + [(1, 12), (-1, 12), (1, -12), (-1, -12), (12, 1), (-12, 1), (12, -1), (-12, -1)] + """ + n, p, k = [as_int(i) for i in (n, p, k)] + + if n < 0: + if p % 2: + for t in power_representation(-n, p, k, zeros): + yield tuple(-i for i in t) + return + + if p < 1 or k < 1: + raise ValueError(filldedent(''' + Expecting positive integers for `(p, k)`, but got `(%s, %s)`''' + % (p, k))) + + if n == 0: + if zeros: + yield (0,)*k + return + + if k == 1: + if p == 1: + yield (n,) + elif n == 1: + yield (1,) + else: + be = perfect_power(n) + if be: + b, e = be + d, r = divmod(e, p) + if not r: + yield (b**d,) + return + + if p == 1: + yield from partition(n, k, zeros=zeros) + return + + if p == 2: + if k == 3: + n, v = remove(n, 4) + if v: + v = 1 << v + for t in power_representation(n, p, k, zeros): + yield tuple(i*v for i in t) + return + feasible = _can_do_sum_of_squares(n, k) + if not feasible: + return + if not zeros: + if n > 33 and k >= 5 and k <= n and n - k in ( + 13, 10, 7, 5, 4, 2, 1): + '''Todd G. Will, "When Is n^2 a Sum of k Squares?", [online]. + Available: https://www.maa.org/sites/default/files/Will-MMz-201037918.pdf''' + return + # quick tests since feasibility includes the possibility of 0 + if k == 4 and (n in (1, 3, 5, 9, 11, 17, 29, 41) or remove(n, 4)[0] in (2, 6, 14)): + # A000534 + return + if k == 3 and n in (1, 2, 5, 10, 13, 25, 37, 58, 85, 130): # or n = some number >= 5*10**10 + # A051952 + return + if feasible is not True: # it's prime and k == 2 + yield prime_as_sum_of_two_squares(n) + return + + if k == 2 and p > 2: + be = perfect_power(n) + if be and be[1] % p == 0: + return # Fermat: a**n + b**n = c**n has no solution for n > 2 + + if n >= k: + a = integer_nthroot(n - (k - 1), p)[0] + for t in pow_rep_recursive(a, k, n, [], p): + yield tuple(reversed(t)) + + if zeros: + a = integer_nthroot(n, p)[0] + for i in range(1, k): + for t in pow_rep_recursive(a, i, n, [], p): + yield tuple(reversed(t + (0,)*(k - i))) + + +sum_of_powers = power_representation + + +def pow_rep_recursive(n_i, k, n_remaining, terms, p): + # Invalid arguments + if n_i <= 0 or k <= 0: + return + + # No solutions may exist + if n_remaining < k: + return + if k * pow(n_i, p) < n_remaining: + return + + if k == 0 and n_remaining == 0: + yield tuple(terms) + + elif k == 1: + # next_term^p must equal to n_remaining + next_term, exact = integer_nthroot(n_remaining, p) + if exact and next_term <= n_i: + yield tuple(terms + [next_term]) + return + + else: + # TODO: Fall back to diop_DN when k = 2 + if n_i >= 1 and k > 0: + for next_term in range(1, n_i + 1): + residual = n_remaining - pow(next_term, p) + if residual < 0: + break + yield from pow_rep_recursive(next_term, k - 1, residual, terms + [next_term], p) + + +def sum_of_squares(n, k, zeros=False): + """Return a generator that yields the k-tuples of nonnegative + values, the squares of which sum to n. If zeros is False (default) + then the solution will not contain zeros. The nonnegative + elements of a tuple are sorted. + + * If k == 1 and n is square, (n,) is returned. + + * If k == 2 then n can only be written as a sum of squares if + every prime in the factorization of n that has the form + 4*k + 3 has an even multiplicity. If n is prime then + it can only be written as a sum of two squares if it is + in the form 4*k + 1. + + * if k == 3 then n can be written as a sum of squares if it does + not have the form 4**m*(8*k + 7). + + * all integers can be written as the sum of 4 squares. + + * if k > 4 then n can be partitioned and each partition can + be written as a sum of 4 squares; if n is not evenly divisible + by 4 then n can be written as a sum of squares only if the + an additional partition can be written as sum of squares. + For example, if k = 6 then n is partitioned into two parts, + the first being written as a sum of 4 squares and the second + being written as a sum of 2 squares -- which can only be + done if the condition above for k = 2 can be met, so this will + automatically reject certain partitions of n. + + Examples + ======== + + >>> from sympy.solvers.diophantine.diophantine import sum_of_squares + >>> list(sum_of_squares(25, 2)) + [(3, 4)] + >>> list(sum_of_squares(25, 2, True)) + [(3, 4), (0, 5)] + >>> list(sum_of_squares(25, 4)) + [(1, 2, 2, 4)] + + See Also + ======== + + sympy.utilities.iterables.signed_permutations + """ + yield from power_representation(n, 2, k, zeros) + + +def _can_do_sum_of_squares(n, k): + """Return True if n can be written as the sum of k squares, + False if it cannot, or 1 if ``k == 2`` and ``n`` is prime (in which + case it *can* be written as a sum of two squares). A False + is returned only if it cannot be written as ``k``-squares, even + if 0s are allowed. + """ + if k < 1: + return False + if n < 0: + return False + if n == 0: + return True + if k == 1: + return is_square(n) + if k == 2: + if n in (1, 2): + return True + if isprime(n): + if n % 4 == 1: + return 1 # signal that it was prime + return False + # n is a composite number + # we can proceed iff no prime factor in the form 4*k + 3 + # has an odd multiplicity + return all(p % 4 !=3 or m % 2 == 0 for p, m in factorint(n).items()) + if k == 3: + return remove(n, 4)[0] % 8 != 7 + # every number can be written as a sum of 4 squares; for k > 4 partitions + # can be 0 + return True diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/tests/test_diophantine.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/tests/test_diophantine.py new file mode 100644 index 0000000000000000000000000000000000000000..b8b031a1e63fa445e3dbb0b425f84cfe88888667 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/diophantine/tests/test_diophantine.py @@ -0,0 +1,1071 @@ +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.numbers import (Rational, oo, pi) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import symbols +from sympy.matrices.dense import Matrix +from sympy.ntheory.factor_ import factorint +from sympy.simplify.powsimp import powsimp +from sympy.core.function import _mexpand +from sympy.core.sorting import default_sort_key, ordered +from sympy.functions.elementary.trigonometric import sin +from sympy.solvers.diophantine import diophantine +from sympy.solvers.diophantine.diophantine import (diop_DN, + diop_solve, diop_ternary_quadratic_normal, + diop_general_pythagorean, diop_ternary_quadratic, diop_linear, + diop_quadratic, diop_general_sum_of_squares, diop_general_sum_of_even_powers, + descent, diop_bf_DN, divisible, equivalent, find_DN, ldescent, length, + reconstruct, partition, power_representation, + prime_as_sum_of_two_squares, square_factor, sum_of_four_squares, + sum_of_three_squares, transformation_to_DN, transformation_to_normal, + classify_diop, base_solution_linear, cornacchia, sqf_normal, gaussian_reduce, holzer, + check_param, parametrize_ternary_quadratic, sum_of_powers, sum_of_squares, + _diop_ternary_quadratic_normal, _nint_or_floor, + _odd, _even, _remove_gcd, _can_do_sum_of_squares, DiophantineSolutionSet, GeneralPythagorean, + BinaryQuadratic) + +from sympy.testing.pytest import slow, raises, XFAIL +from sympy.utilities.iterables import ( + signed_permutations) + +a, b, c, d, p, q, x, y, z, w, t, u, v, X, Y, Z = symbols( + "a, b, c, d, p, q, x, y, z, w, t, u, v, X, Y, Z", integer=True) +t_0, t_1, t_2, t_3, t_4, t_5, t_6 = symbols("t_:7", integer=True) +m1, m2, m3 = symbols('m1:4', integer=True) +n1 = symbols('n1', integer=True) + + +def diop_simplify(eq): + return _mexpand(powsimp(_mexpand(eq))) + + +def test_input_format(): + raises(TypeError, lambda: diophantine(sin(x))) + raises(TypeError, lambda: diophantine(x/pi - 3)) + + +def test_nosols(): + # diophantine should sympify eq so that these are equivalent + assert diophantine(3) == set() + assert diophantine(S(3)) == set() + + +def test_univariate(): + assert diop_solve((x - 1)*(x - 2)**2) == {(1,), (2,)} + assert diop_solve((x - 1)*(x - 2)) == {(1,), (2,)} + + +def test_classify_diop(): + raises(TypeError, lambda: classify_diop(x**2/3 - 1)) + raises(ValueError, lambda: classify_diop(1)) + raises(NotImplementedError, lambda: classify_diop(w*x*y*z - 1)) + raises(NotImplementedError, lambda: classify_diop(x**3 + y**3 + z**4 - 90)) + assert classify_diop(14*x**2 + 15*x - 42) == ( + [x], {1: -42, x: 15, x**2: 14}, 'univariate') + assert classify_diop(x*y + z) == ( + [x, y, z], {x*y: 1, z: 1}, 'inhomogeneous_ternary_quadratic') + assert classify_diop(x*y + z + w + x**2) == ( + [w, x, y, z], {x*y: 1, w: 1, x**2: 1, z: 1}, 'inhomogeneous_general_quadratic') + assert classify_diop(x*y + x*z + x**2 + 1) == ( + [x, y, z], {x*y: 1, x*z: 1, x**2: 1, 1: 1}, 'inhomogeneous_general_quadratic') + assert classify_diop(x*y + z + w + 42) == ( + [w, x, y, z], {x*y: 1, w: 1, 1: 42, z: 1}, 'inhomogeneous_general_quadratic') + assert classify_diop(x*y + z*w) == ( + [w, x, y, z], {x*y: 1, w*z: 1}, 'homogeneous_general_quadratic') + assert classify_diop(x*y**2 + 1) == ( + [x, y], {x*y**2: 1, 1: 1}, 'cubic_thue') + assert classify_diop(x**4 + y**4 + z**4 - (1 + 16 + 81)) == ( + [x, y, z], {1: -98, x**4: 1, z**4: 1, y**4: 1}, 'general_sum_of_even_powers') + assert classify_diop(x**2 + y**2 + z**2) == ( + [x, y, z], {x**2: 1, y**2: 1, z**2: 1}, 'homogeneous_ternary_quadratic_normal') + + +def test_linear(): + assert diop_solve(x) == (0,) + assert diop_solve(1*x) == (0,) + assert diop_solve(3*x) == (0,) + assert diop_solve(x + 1) == (-1,) + assert diop_solve(2*x + 1) == (None,) + assert diop_solve(2*x + 4) == (-2,) + assert diop_solve(y + x) == (t_0, -t_0) + assert diop_solve(y + x + 0) == (t_0, -t_0) + assert diop_solve(y + x - 0) == (t_0, -t_0) + assert diop_solve(0*x - y - 5) == (-5,) + assert diop_solve(3*y + 2*x - 5) == (3*t_0 - 5, -2*t_0 + 5) + assert diop_solve(2*x - 3*y - 5) == (3*t_0 - 5, 2*t_0 - 5) + assert diop_solve(-2*x - 3*y - 5) == (3*t_0 + 5, -2*t_0 - 5) + assert diop_solve(7*x + 5*y) == (5*t_0, -7*t_0) + assert diop_solve(2*x + 4*y) == (-2*t_0, t_0) + assert diop_solve(4*x + 6*y - 4) == (3*t_0 - 2, -2*t_0 + 2) + assert diop_solve(4*x + 6*y - 3) == (None, None) + assert diop_solve(0*x + 3*y - 4*z + 5) == (4*t_0 + 5, 3*t_0 + 5) + assert diop_solve(4*x + 3*y - 4*z + 5) == (t_0, 8*t_0 + 4*t_1 + 5, 7*t_0 + 3*t_1 + 5) + assert diop_solve(4*x + 3*y - 4*z + 5, None) == (0, 5, 5) + assert diop_solve(4*x + 2*y + 8*z - 5) == (None, None, None) + assert diop_solve(5*x + 7*y - 2*z - 6) == (t_0, -3*t_0 + 2*t_1 + 6, -8*t_0 + 7*t_1 + 18) + assert diop_solve(3*x - 6*y + 12*z - 9) == (2*t_0 + 3, t_0 + 2*t_1, t_1) + assert diop_solve(6*w + 9*x + 20*y - z) == (t_0, t_1, t_1 + t_2, 6*t_0 + 29*t_1 + 20*t_2) + + # to ignore constant factors, use diophantine + raises(TypeError, lambda: diop_solve(x/2)) + + +def test_quadratic_simple_hyperbolic_case(): + # Simple Hyperbolic case: A = C = 0 and B != 0 + assert diop_solve(3*x*y + 34*x - 12*y + 1) == \ + {(-133, -11), (5, -57)} + assert diop_solve(6*x*y + 2*x + 3*y + 1) == set() + assert diop_solve(-13*x*y + 2*x - 4*y - 54) == {(27, 0)} + assert diop_solve(-27*x*y - 30*x - 12*y - 54) == {(-14, -1)} + assert diop_solve(2*x*y + 5*x + 56*y + 7) == {(-161, -3), (-47, -6), (-35, -12), + (-29, -69), (-27, 64), (-21, 7), + (-9, 1), (105, -2)} + assert diop_solve(6*x*y + 9*x + 2*y + 3) == set() + assert diop_solve(x*y + x + y + 1) == {(-1, t), (t, -1)} + assert diophantine(48*x*y) + + +def test_quadratic_elliptical_case(): + # Elliptical case: B**2 - 4AC < 0 + + assert diop_solve(42*x**2 + 8*x*y + 15*y**2 + 23*x + 17*y - 4915) == {(-11, -1)} + assert diop_solve(4*x**2 + 3*y**2 + 5*x - 11*y + 12) == set() + assert diop_solve(x**2 + y**2 + 2*x + 2*y + 2) == {(-1, -1)} + assert diop_solve(15*x**2 - 9*x*y + 14*y**2 - 23*x - 14*y - 4950) == {(-15, 6)} + assert diop_solve(10*x**2 + 12*x*y + 12*y**2 - 34) == \ + {(-1, -1), (-1, 2), (1, -2), (1, 1)} + + +def test_quadratic_parabolic_case(): + # Parabolic case: B**2 - 4AC = 0 + assert check_solutions(8*x**2 - 24*x*y + 18*y**2 + 5*x + 7*y + 16) + assert check_solutions(8*x**2 - 24*x*y + 18*y**2 + 6*x + 12*y - 6) + assert check_solutions(8*x**2 + 24*x*y + 18*y**2 + 4*x + 6*y - 7) + assert check_solutions(-4*x**2 + 4*x*y - y**2 + 2*x - 3) + assert check_solutions(x**2 + 2*x*y + y**2 + 2*x + 2*y + 1) + assert check_solutions(x**2 - 2*x*y + y**2 + 2*x + 2*y + 1) + assert check_solutions(y**2 - 41*x + 40) + + +def test_quadratic_perfect_square(): + # B**2 - 4*A*C > 0 + # B**2 - 4*A*C is a perfect square + assert check_solutions(48*x*y) + assert check_solutions(4*x**2 - 5*x*y + y**2 + 2) + assert check_solutions(-2*x**2 - 3*x*y + 2*y**2 -2*x - 17*y + 25) + assert check_solutions(12*x**2 + 13*x*y + 3*y**2 - 2*x + 3*y - 12) + assert check_solutions(8*x**2 + 10*x*y + 2*y**2 - 32*x - 13*y - 23) + assert check_solutions(4*x**2 - 4*x*y - 3*y- 8*x - 3) + assert check_solutions(- 4*x*y - 4*y**2 - 3*y- 5*x - 10) + assert check_solutions(x**2 - y**2 - 2*x - 2*y) + assert check_solutions(x**2 - 9*y**2 - 2*x - 6*y) + assert check_solutions(4*x**2 - 9*y**2 - 4*x - 12*y - 3) + + +def test_quadratic_non_perfect_square(): + # B**2 - 4*A*C is not a perfect square + # Used check_solutions() since the solutions are complex expressions involving + # square roots and exponents + assert check_solutions(x**2 - 2*x - 5*y**2) + assert check_solutions(3*x**2 - 2*y**2 - 2*x - 2*y) + assert check_solutions(x**2 - x*y - y**2 - 3*y) + assert check_solutions(x**2 - 9*y**2 - 2*x - 6*y) + assert BinaryQuadratic(x**2 + y**2 + 2*x + 2*y + 2).solve() == {(-1, -1)} + + +def test_issue_9106(): + eq = -48 - 2*x*(3*x - 1) + y*(3*y - 1) + v = (x, y) + for sol in diophantine(eq): + assert not diop_simplify(eq.xreplace(dict(zip(v, sol)))) + + +def test_issue_18138(): + eq = x**2 - x - y**2 + v = (x, y) + for sol in diophantine(eq): + assert not diop_simplify(eq.xreplace(dict(zip(v, sol)))) + + +@slow +def test_quadratic_non_perfect_slow(): + assert check_solutions(8*x**2 + 10*x*y - 2*y**2 - 32*x - 13*y - 23) + # This leads to very large numbers. + # assert check_solutions(5*x**2 - 13*x*y + y**2 - 4*x - 4*y - 15) + assert check_solutions(-3*x**2 - 2*x*y + 7*y**2 - 5*x - 7) + assert check_solutions(-4 - x + 4*x**2 - y - 3*x*y - 4*y**2) + assert check_solutions(1 + 2*x + 2*x**2 + 2*y + x*y - 2*y**2) + + +def test_DN(): + # Most of the test cases were adapted from, + # Solving the generalized Pell equation x**2 - D*y**2 = N, John P. Robertson, July 31, 2004. + # https://web.archive.org/web/20160323033128/http://www.jpr2718.org/pell.pdf + # others are verified using Wolfram Alpha. + + # Covers cases where D <= 0 or D > 0 and D is a square or N = 0 + # Solutions are straightforward in these cases. + assert diop_DN(3, 0) == [(0, 0)] + assert diop_DN(-17, -5) == [] + assert diop_DN(-19, 23) == [(2, 1)] + assert diop_DN(-13, 17) == [(2, 1)] + assert diop_DN(-15, 13) == [] + assert diop_DN(0, 5) == [] + assert diop_DN(0, 9) == [(3, t)] + assert diop_DN(9, 0) == [(3*t, t)] + assert diop_DN(16, 24) == [] + assert diop_DN(9, 180) == [(18, 4)] + assert diop_DN(9, -180) == [(12, 6)] + assert diop_DN(7, 0) == [(0, 0)] + + # When equation is x**2 + y**2 = N + # Solutions are interchangeable + assert diop_DN(-1, 5) == [(2, 1), (1, 2)] + assert diop_DN(-1, 169) == [(12, 5), (5, 12), (13, 0), (0, 13)] + + # D > 0 and D is not a square + + # N = 1 + assert diop_DN(13, 1) == [(649, 180)] + assert diop_DN(980, 1) == [(51841, 1656)] + assert diop_DN(981, 1) == [(158070671986249, 5046808151700)] + assert diop_DN(986, 1) == [(49299, 1570)] + assert diop_DN(991, 1) == [(379516400906811930638014896080, 12055735790331359447442538767)] + assert diop_DN(17, 1) == [(33, 8)] + assert diop_DN(19, 1) == [(170, 39)] + + # N = -1 + assert diop_DN(13, -1) == [(18, 5)] + assert diop_DN(991, -1) == [] + assert diop_DN(41, -1) == [(32, 5)] + assert diop_DN(290, -1) == [(17, 1)] + assert diop_DN(21257, -1) == [(13913102721304, 95427381109)] + assert diop_DN(32, -1) == [] + + # |N| > 1 + # Some tests were created using calculator at + # http://www.numbertheory.org/php/patz.html + + assert diop_DN(13, -4) == [(3, 1), (393, 109), (36, 10)] + # Source I referred returned (3, 1), (393, 109) and (-3, 1) as fundamental solutions + # So (-3, 1) and (393, 109) should be in the same equivalent class + assert equivalent(-3, 1, 393, 109, 13, -4) == True + + assert diop_DN(13, 27) == [(220, 61), (40, 11), (768, 213), (12, 3)] + assert set(diop_DN(157, 12)) == {(13, 1), (10663, 851), (579160, 46222), + (483790960, 38610722), (26277068347, 2097138361), + (21950079635497, 1751807067011)} + assert diop_DN(13, 25) == [(3245, 900)] + assert diop_DN(192, 18) == [] + assert diop_DN(23, 13) == [(-6, 1), (6, 1)] + assert diop_DN(167, 2) == [(13, 1)] + assert diop_DN(167, -2) == [] + + assert diop_DN(123, -2) == [(11, 1)] + # One calculator returned [(11, 1), (-11, 1)] but both of these are in + # the same equivalence class + assert equivalent(11, 1, -11, 1, 123, -2) + + assert diop_DN(123, -23) == [(-10, 1), (10, 1)] + + assert diop_DN(0, 0, t) == [(0, t)] + assert diop_DN(0, -1, t) == [] + + +def test_bf_pell(): + assert diop_bf_DN(13, -4) == [(3, 1), (-3, 1), (36, 10)] + assert diop_bf_DN(13, 27) == [(12, 3), (-12, 3), (40, 11), (-40, 11)] + assert diop_bf_DN(167, -2) == [] + assert diop_bf_DN(1729, 1) == [(44611924489705, 1072885712316)] + assert diop_bf_DN(89, -8) == [(9, 1), (-9, 1)] + assert diop_bf_DN(21257, -1) == [(13913102721304, 95427381109)] + assert diop_bf_DN(340, -4) == [(756, 41)] + assert diop_bf_DN(-1, 0, t) == [(0, 0)] + assert diop_bf_DN(0, 0, t) == [(0, t)] + assert diop_bf_DN(4, 0, t) == [(2*t, t), (-2*t, t)] + assert diop_bf_DN(3, 0, t) == [(0, 0)] + assert diop_bf_DN(1, -2, t) == [] + + +def test_length(): + assert length(2, 1, 0) == 1 + assert length(-2, 4, 5) == 3 + assert length(-5, 4, 17) == 4 + assert length(0, 4, 13) == 6 + assert length(7, 13, 11) == 23 + assert length(1, 6, 4) == 2 + + +def is_pell_transformation_ok(eq): + """ + Test whether X*Y, X, or Y terms are present in the equation + after transforming the equation using the transformation returned + by transformation_to_pell(). If they are not present we are good. + Moreover, coefficient of X**2 should be a divisor of coefficient of + Y**2 and the constant term. + """ + A, B = transformation_to_DN(eq) + u = (A*Matrix([X, Y]) + B)[0] + v = (A*Matrix([X, Y]) + B)[1] + simplified = diop_simplify(eq.subs(zip((x, y), (u, v)))) + + coeff = dict([reversed(t.as_independent(*[X, Y])) for t in simplified.args]) + + for term in [X*Y, X, Y]: + if term in coeff.keys(): + return False + + for term in [X**2, Y**2, 1]: + if term not in coeff.keys(): + coeff[term] = 0 + + if coeff[X**2] != 0: + return divisible(coeff[Y**2], coeff[X**2]) and \ + divisible(coeff[1], coeff[X**2]) + + return True + + +def test_transformation_to_pell(): + assert is_pell_transformation_ok(-13*x**2 - 7*x*y + y**2 + 2*x - 2*y - 14) + assert is_pell_transformation_ok(-17*x**2 + 19*x*y - 7*y**2 - 5*x - 13*y - 23) + assert is_pell_transformation_ok(x**2 - y**2 + 17) + assert is_pell_transformation_ok(-x**2 + 7*y**2 - 23) + assert is_pell_transformation_ok(25*x**2 - 45*x*y + 5*y**2 - 5*x - 10*y + 5) + assert is_pell_transformation_ok(190*x**2 + 30*x*y + y**2 - 3*y - 170*x - 130) + assert is_pell_transformation_ok(x**2 - 2*x*y -190*y**2 - 7*y - 23*x - 89) + assert is_pell_transformation_ok(15*x**2 - 9*x*y + 14*y**2 - 23*x - 14*y - 4950) + + +def test_find_DN(): + assert find_DN(x**2 - 2*x - y**2) == (1, 1) + assert find_DN(x**2 - 3*y**2 - 5) == (3, 5) + assert find_DN(x**2 - 2*x*y - 4*y**2 - 7) == (5, 7) + assert find_DN(4*x**2 - 8*x*y - y**2 - 9) == (20, 36) + assert find_DN(7*x**2 - 2*x*y - y**2 - 12) == (8, 84) + assert find_DN(-3*x**2 + 4*x*y -y**2) == (1, 0) + assert find_DN(-13*x**2 - 7*x*y + y**2 + 2*x - 2*y -14) == (101, -7825480) + + +def test_ldescent(): + # Equations which have solutions + u = ([(13, 23), (3, -11), (41, -113), (4, -7), (-7, 4), (91, -3), (1, 1), (1, -1), + (4, 32), (17, 13), (123689, 1), (19, -570)]) + for a, b in u: + w, x, y = ldescent(a, b) + assert a*x**2 + b*y**2 == w**2 + assert ldescent(-1, -1) is None + assert ldescent(2, 6) is None + + +def test_diop_ternary_quadratic_normal(): + assert check_solutions(234*x**2 - 65601*y**2 - z**2) + assert check_solutions(23*x**2 + 616*y**2 - z**2) + assert check_solutions(5*x**2 + 4*y**2 - z**2) + assert check_solutions(3*x**2 + 6*y**2 - 3*z**2) + assert check_solutions(x**2 + 3*y**2 - z**2) + assert check_solutions(4*x**2 + 5*y**2 - z**2) + assert check_solutions(x**2 + y**2 - z**2) + assert check_solutions(16*x**2 + y**2 - 25*z**2) + assert check_solutions(6*x**2 - y**2 + 10*z**2) + assert check_solutions(213*x**2 + 12*y**2 - 9*z**2) + assert check_solutions(34*x**2 - 3*y**2 - 301*z**2) + assert check_solutions(124*x**2 - 30*y**2 - 7729*z**2) + + +def is_normal_transformation_ok(eq): + A = transformation_to_normal(eq) + X, Y, Z = A*Matrix([x, y, z]) + simplified = diop_simplify(eq.subs(zip((x, y, z), (X, Y, Z)))) + + coeff = dict([reversed(t.as_independent(*[X, Y, Z])) for t in simplified.args]) + for term in [X*Y, Y*Z, X*Z]: + if term in coeff.keys(): + return False + + return True + + +def test_transformation_to_normal(): + assert is_normal_transformation_ok(x**2 + 3*y**2 + z**2 - 13*x*y - 16*y*z + 12*x*z) + assert is_normal_transformation_ok(x**2 + 3*y**2 - 100*z**2) + assert is_normal_transformation_ok(x**2 + 23*y*z) + assert is_normal_transformation_ok(3*y**2 - 100*z**2 - 12*x*y) + assert is_normal_transformation_ok(x**2 + 23*x*y - 34*y*z + 12*x*z) + assert is_normal_transformation_ok(z**2 + 34*x*y - 23*y*z + x*z) + assert is_normal_transformation_ok(x**2 + y**2 + z**2 - x*y - y*z - x*z) + assert is_normal_transformation_ok(x**2 + 2*y*z + 3*z**2) + assert is_normal_transformation_ok(x*y + 2*x*z + 3*y*z) + assert is_normal_transformation_ok(2*x*z + 3*y*z) + + +def test_diop_ternary_quadratic(): + assert check_solutions(2*x**2 + z**2 + y**2 - 4*x*y) + assert check_solutions(x**2 - y**2 - z**2 - x*y - y*z) + assert check_solutions(3*x**2 - x*y - y*z - x*z) + assert check_solutions(x**2 - y*z - x*z) + assert check_solutions(5*x**2 - 3*x*y - x*z) + assert check_solutions(4*x**2 - 5*y**2 - x*z) + assert check_solutions(3*x**2 + 2*y**2 - z**2 - 2*x*y + 5*y*z - 7*y*z) + assert check_solutions(8*x**2 - 12*y*z) + assert check_solutions(45*x**2 - 7*y**2 - 8*x*y - z**2) + assert check_solutions(x**2 - 49*y**2 - z**2 + 13*z*y -8*x*y) + assert check_solutions(90*x**2 + 3*y**2 + 5*x*y + 2*z*y + 5*x*z) + assert check_solutions(x**2 + 3*y**2 + z**2 - x*y - 17*y*z) + assert check_solutions(x**2 + 3*y**2 + z**2 - x*y - 16*y*z + 12*x*z) + assert check_solutions(x**2 + 3*y**2 + z**2 - 13*x*y - 16*y*z + 12*x*z) + assert check_solutions(x*y - 7*y*z + 13*x*z) + + assert diop_ternary_quadratic_normal(x**2 + y**2 + z**2) == (None, None, None) + assert diop_ternary_quadratic_normal(x**2 + y**2) is None + raises(ValueError, lambda: + _diop_ternary_quadratic_normal((x, y, z), + {x*y: 1, x**2: 2, y**2: 3, z**2: 0})) + eq = -2*x*y - 6*x*z + 7*y**2 - 3*y*z + 4*z**2 + assert diop_ternary_quadratic(eq) == (7, 2, 0) + assert diop_ternary_quadratic_normal(4*x**2 + 5*y**2 - z**2) == \ + (1, 0, 2) + assert diop_ternary_quadratic(x*y + 2*y*z) == \ + (-2, 0, n1) + eq = -5*x*y - 8*x*z - 3*y*z + 8*z**2 + assert parametrize_ternary_quadratic(eq) == \ + (8*p**2 - 3*p*q, -8*p*q + 8*q**2, 5*p*q) + # this cannot be tested with diophantine because it will + # factor into a product + assert diop_solve(x*y + 2*y*z) == (-2*p*q, -n1*p**2 + p**2, p*q) + + +def test_square_factor(): + assert square_factor(1) == square_factor(-1) == 1 + assert square_factor(0) == 1 + assert square_factor(5) == square_factor(-5) == 1 + assert square_factor(4) == square_factor(-4) == 2 + assert square_factor(12) == square_factor(-12) == 2 + assert square_factor(6) == 1 + assert square_factor(18) == 3 + assert square_factor(52) == 2 + assert square_factor(49) == 7 + assert square_factor(392) == 14 + assert square_factor(factorint(-12)) == 2 + + +def test_parametrize_ternary_quadratic(): + assert check_solutions(x**2 + y**2 - z**2) + assert check_solutions(x**2 + 2*x*y + z**2) + assert check_solutions(234*x**2 - 65601*y**2 - z**2) + assert check_solutions(3*x**2 + 2*y**2 - z**2 - 2*x*y + 5*y*z - 7*y*z) + assert check_solutions(x**2 - y**2 - z**2) + assert check_solutions(x**2 - 49*y**2 - z**2 + 13*z*y - 8*x*y) + assert check_solutions(8*x*y + z**2) + assert check_solutions(124*x**2 - 30*y**2 - 7729*z**2) + assert check_solutions(236*x**2 - 225*y**2 - 11*x*y - 13*y*z - 17*x*z) + assert check_solutions(90*x**2 + 3*y**2 + 5*x*y + 2*z*y + 5*x*z) + assert check_solutions(124*x**2 - 30*y**2 - 7729*z**2) + + +def test_no_square_ternary_quadratic(): + assert check_solutions(2*x*y + y*z - 3*x*z) + assert check_solutions(189*x*y - 345*y*z - 12*x*z) + assert check_solutions(23*x*y + 34*y*z) + assert check_solutions(x*y + y*z + z*x) + assert check_solutions(23*x*y + 23*y*z + 23*x*z) + + +def test_descent(): + + u = ([(13, 23), (3, -11), (41, -113), (91, -3), (1, 1), (1, -1), (17, 13), (123689, 1), (19, -570)]) + for a, b in u: + w, x, y = descent(a, b) + assert a*x**2 + b*y**2 == w**2 + # the docstring warns against bad input, so these are expected results + # - can't both be negative + raises(TypeError, lambda: descent(-1, -3)) + # A can't be zero unless B != 1 + raises(ZeroDivisionError, lambda: descent(0, 3)) + # supposed to be square-free + raises(TypeError, lambda: descent(4, 3)) + + +def test_diophantine(): + assert check_solutions((x - y)*(y - z)*(z - x)) + assert check_solutions((x - y)*(x**2 + y**2 - z**2)) + assert check_solutions((x - 3*y + 7*z)*(x**2 + y**2 - z**2)) + assert check_solutions(x**2 - 3*y**2 - 1) + assert check_solutions(y**2 + 7*x*y) + assert check_solutions(x**2 - 3*x*y + y**2) + assert check_solutions(z*(x**2 - y**2 - 15)) + assert check_solutions(x*(2*y - 2*z + 5)) + assert check_solutions((x**2 - 3*y**2 - 1)*(x**2 - y**2 - 15)) + assert check_solutions((x**2 - 3*y**2 - 1)*(y - 7*z)) + assert check_solutions((x**2 + y**2 - z**2)*(x - 7*y - 3*z + 4*w)) + # Following test case caused problems in parametric representation + # But this can be solved by factoring out y. + # No need to use methods for ternary quadratic equations. + assert check_solutions(y**2 - 7*x*y + 4*y*z) + assert check_solutions(x**2 - 2*x + 1) + + assert diophantine(x - y) == diophantine(Eq(x, y)) + # 18196 + eq = x**4 + y**4 - 97 + assert diophantine(eq, permute=True) == diophantine(-eq, permute=True) + assert diophantine(3*x*pi - 2*y*pi) == {(2*t_0, 3*t_0)} + eq = x**2 + y**2 + z**2 - 14 + base_sol = {(1, 2, 3)} + assert diophantine(eq) == base_sol + complete_soln = set(signed_permutations(base_sol.pop())) + assert diophantine(eq, permute=True) == complete_soln + + assert diophantine(x**2 + x*Rational(15, 14) - 3) == set() + # test issue 11049 + eq = 92*x**2 - 99*y**2 - z**2 + coeff = eq.as_coefficients_dict() + assert _diop_ternary_quadratic_normal((x, y, z), coeff) == \ + {(9, 7, 51)} + assert diophantine(eq) == {( + 891*p**2 + 9*q**2, -693*p**2 - 102*p*q + 7*q**2, + 5049*p**2 - 1386*p*q - 51*q**2)} + eq = 2*x**2 + 2*y**2 - z**2 + coeff = eq.as_coefficients_dict() + assert _diop_ternary_quadratic_normal((x, y, z), coeff) == \ + {(1, 1, 2)} + assert diophantine(eq) == {( + 2*p**2 - q**2, -2*p**2 + 4*p*q - q**2, + 4*p**2 - 4*p*q + 2*q**2)} + eq = 411*x**2+57*y**2-221*z**2 + coeff = eq.as_coefficients_dict() + assert _diop_ternary_quadratic_normal((x, y, z), coeff) == \ + {(2021, 2645, 3066)} + assert diophantine(eq) == \ + {(115197*p**2 - 446641*q**2, -150765*p**2 + 1355172*p*q - + 584545*q**2, 174762*p**2 - 301530*p*q + 677586*q**2)} + eq = 573*x**2+267*y**2-984*z**2 + coeff = eq.as_coefficients_dict() + assert _diop_ternary_quadratic_normal((x, y, z), coeff) == \ + {(49, 233, 127)} + assert diophantine(eq) == \ + {(4361*p**2 - 16072*q**2, -20737*p**2 + 83312*p*q - 76424*q**2, + 11303*p**2 - 41474*p*q + 41656*q**2)} + # this produces factors during reconstruction + eq = x**2 + 3*y**2 - 12*z**2 + coeff = eq.as_coefficients_dict() + assert _diop_ternary_quadratic_normal((x, y, z), coeff) == \ + {(0, 2, 1)} + assert diophantine(eq) == \ + {(24*p*q, 2*p**2 - 24*q**2, p**2 + 12*q**2)} + # solvers have not been written for every type + raises(NotImplementedError, lambda: diophantine(x*y**2 + 1)) + + # rational expressions + assert diophantine(1/x) == set() + assert diophantine(1/x + 1/y - S.Half) == {(6, 3), (-2, 1), (4, 4), (1, -2), (3, 6)} + assert diophantine(x**2 + y**2 +3*x- 5, permute=True) == \ + {(-1, 1), (-4, -1), (1, -1), (1, 1), (-4, 1), (-1, -1), (4, 1), (4, -1)} + + + #test issue 18186 + assert diophantine(y**4 + x**4 - 2**4 - 3**4, syms=(x, y), permute=True) == \ + {(-3, -2), (-3, 2), (-2, -3), (-2, 3), (2, -3), (2, 3), (3, -2), (3, 2)} + assert diophantine(y**4 + x**4 - 2**4 - 3**4, syms=(y, x), permute=True) == \ + {(-3, -2), (-3, 2), (-2, -3), (-2, 3), (2, -3), (2, 3), (3, -2), (3, 2)} + + # issue 18122 + assert check_solutions(x**2 - y) + assert check_solutions(y**2 - x) + assert diophantine((x**2 - y), t) == {(t, t**2)} + assert diophantine((y**2 - x), t) == {(t**2, t)} + + +def test_general_pythagorean(): + from sympy.abc import a, b, c, d, e + + assert check_solutions(a**2 + b**2 + c**2 - d**2) + assert check_solutions(a**2 + 4*b**2 + 4*c**2 - d**2) + assert check_solutions(9*a**2 + 4*b**2 + 4*c**2 - d**2) + assert check_solutions(9*a**2 + 4*b**2 - 25*d**2 + 4*c**2 ) + assert check_solutions(9*a**2 - 16*d**2 + 4*b**2 + 4*c**2) + assert check_solutions(-e**2 + 9*a**2 + 4*b**2 + 4*c**2 + 25*d**2) + assert check_solutions(16*a**2 - b**2 + 9*c**2 + d**2 + 25*e**2) + + assert GeneralPythagorean(a**2 + b**2 + c**2 - d**2).solve(parameters=[x, y, z]) == \ + {(x**2 + y**2 - z**2, 2*x*z, 2*y*z, x**2 + y**2 + z**2)} + + +def test_diop_general_sum_of_squares_quick(): + for i in range(3, 10): + assert check_solutions(sum(i**2 for i in symbols(':%i' % i)) - i) + + assert diop_general_sum_of_squares(x**2 + y**2 - 2) is None + assert diop_general_sum_of_squares(x**2 + y**2 + z**2 + 2) == set() + eq = x**2 + y**2 + z**2 - (1 + 4 + 9) + assert diop_general_sum_of_squares(eq) == \ + {(1, 2, 3)} + eq = u**2 + v**2 + x**2 + y**2 + z**2 - 1313 + assert len(diop_general_sum_of_squares(eq, 3)) == 3 + # issue 11016 + var = symbols(':5') + (symbols('6', negative=True),) + eq = Add(*[i**2 for i in var]) - 112 + + base_soln = {(0, 1, 1, 5, 6, -7), (1, 1, 1, 3, 6, -8), (2, 3, 3, 4, 5, -7), (0, 1, 1, 1, 3, -10), + (0, 0, 4, 4, 4, -8), (1, 2, 3, 3, 5, -8), (0, 1, 2, 3, 7, -7), (2, 2, 4, 4, 6, -6), + (1, 1, 3, 4, 6, -7), (0, 2, 3, 3, 3, -9), (0, 0, 2, 2, 2, -10), (1, 1, 2, 3, 4, -9), + (0, 1, 1, 2, 5, -9), (0, 0, 2, 6, 6, -6), (1, 3, 4, 5, 5, -6), (0, 2, 2, 2, 6, -8), + (0, 3, 3, 3, 6, -7), (0, 2, 3, 5, 5, -7), (0, 1, 5, 5, 5, -6)} + assert diophantine(eq) == base_soln + assert len(diophantine(eq, permute=True)) == 196800 + + # handle negated squares with signsimp + assert diophantine(12 - x**2 - y**2 - z**2) == {(2, 2, 2)} + # diophantine handles simplification, so classify_diop should + # not have to look for additional patterns that are removed + # by diophantine + eq = a**2 + b**2 + c**2 + d**2 - 4 + raises(NotImplementedError, lambda: classify_diop(-eq)) + + +def test_issue_23807(): + # fixes recursion error + eq = x**2 + y**2 + z**2 - 1000000 + base_soln = {(0, 0, 1000), (0, 352, 936), (480, 600, 640), (24, 640, 768), (192, 640, 744), + (192, 480, 856), (168, 224, 960), (0, 600, 800), (280, 576, 768), (152, 480, 864), + (0, 280, 960), (352, 360, 864), (424, 480, 768), (360, 480, 800), (224, 600, 768), + (96, 360, 928), (168, 576, 800), (96, 480, 872)} + + assert diophantine(eq) == base_soln + + +def test_diop_partition(): + for n in [8, 10]: + for k in range(1, 8): + for p in partition(n, k): + assert len(p) == k + assert list(partition(3, 5)) == [] + assert [list(p) for p in partition(3, 5, 1)] == [ + [0, 0, 0, 0, 3], [0, 0, 0, 1, 2], [0, 0, 1, 1, 1]] + assert list(partition(0)) == [()] + assert list(partition(1, 0)) == [()] + assert [list(i) for i in partition(3)] == [[1, 1, 1], [1, 2], [3]] + + +def test_prime_as_sum_of_two_squares(): + for i in [5, 13, 17, 29, 37, 41, 2341, 3557, 34841, 64601]: + a, b = prime_as_sum_of_two_squares(i) + assert a**2 + b**2 == i + assert prime_as_sum_of_two_squares(7) is None + ans = prime_as_sum_of_two_squares(800029) + assert ans == (450, 773) and type(ans[0]) is int + + +def test_sum_of_three_squares(): + for i in [0, 1, 2, 34, 123, 34304595905, 34304595905394941, 343045959052344, + 800, 801, 802, 803, 804, 805, 806]: + a, b, c = sum_of_three_squares(i) + assert a**2 + b**2 + c**2 == i + assert a >= 0 + + # error + raises(ValueError, lambda: sum_of_three_squares(-1)) + + assert sum_of_three_squares(7) is None + assert sum_of_three_squares((4**5)*15) is None + # if there are two zeros, there might be a solution + # with only one zero, e.g. 25 => (0, 3, 4) or + # with no zeros, e.g. 49 => (2, 3, 6) + assert sum_of_three_squares(25) == (0, 0, 5) + assert sum_of_three_squares(4) == (0, 0, 2) + + +def test_sum_of_four_squares(): + from sympy.core.random import randint + + # this should never fail + n = randint(1, 100000000000000) + assert sum(i**2 for i in sum_of_four_squares(n)) == n + + # error + raises(ValueError, lambda: sum_of_four_squares(-1)) + + for n in range(1000): + result = sum_of_four_squares(n) + assert len(result) == 4 + assert all(r >= 0 for r in result) + assert sum(r**2 for r in result) == n + assert list(result) == sorted(result) + + +def test_power_representation(): + tests = [(1729, 3, 2), (234, 2, 4), (2, 1, 2), (3, 1, 3), (5, 2, 2), (12352, 2, 4), + (32760, 2, 3)] + + for test in tests: + n, p, k = test + f = power_representation(n, p, k) + + while True: + try: + l = next(f) + assert len(l) == k + + chk_sum = 0 + for l_i in l: + chk_sum = chk_sum + l_i**p + assert chk_sum == n + + except StopIteration: + break + + assert list(power_representation(20, 2, 4, True)) == \ + [(1, 1, 3, 3), (0, 0, 2, 4)] + raises(ValueError, lambda: list(power_representation(1.2, 2, 2))) + raises(ValueError, lambda: list(power_representation(2, 0, 2))) + raises(ValueError, lambda: list(power_representation(2, 2, 0))) + assert list(power_representation(-1, 2, 2)) == [] + assert list(power_representation(1, 1, 1)) == [(1,)] + assert list(power_representation(3, 2, 1)) == [] + assert list(power_representation(4, 2, 1)) == [(2,)] + assert list(power_representation(3**4, 4, 6, zeros=True)) == \ + [(1, 2, 2, 2, 2, 2), (0, 0, 0, 0, 0, 3)] + assert list(power_representation(3**4, 4, 5, zeros=False)) == [] + assert list(power_representation(-2, 3, 2)) == [(-1, -1)] + assert list(power_representation(-2, 4, 2)) == [] + assert list(power_representation(0, 3, 2, True)) == [(0, 0)] + assert list(power_representation(0, 3, 2, False)) == [] + # when we are dealing with squares, do feasibility checks + assert len(list(power_representation(4**10*(8*10 + 7), 2, 3))) == 0 + # there will be a recursion error if these aren't recognized + big = 2**30 + for i in [13, 10, 7, 5, 4, 2, 1]: + assert list(sum_of_powers(big, 2, big - i)) == [] + + +def test_assumptions(): + """ + Test whether diophantine respects the assumptions. + """ + #Test case taken from the below so question regarding assumptions in diophantine module + #https://stackoverflow.com/questions/23301941/how-can-i-declare-natural-symbols-with-sympy + m, n = symbols('m n', integer=True, positive=True) + diof = diophantine(n**2 + m*n - 500) + assert diof == {(5, 20), (40, 10), (95, 5), (121, 4), (248, 2), (499, 1)} + + a, b = symbols('a b', integer=True, positive=False) + diof = diophantine(a*b + 2*a + 3*b - 6) + assert diof == {(-15, -3), (-9, -4), (-7, -5), (-6, -6), (-5, -8), (-4, -14)} + + x, y = symbols('x y', integer=True) + diof = diophantine(10*x**2 + 5*x*y - 3*y) + assert diof == {(1, -5), (-3, 5), (0, 0)} + + x, y = symbols('x y', integer=True, positive=True) + diof = diophantine(10*x**2 + 5*x*y - 3*y) + assert diof == set() + + x, y = symbols('x y', integer=True, negative=False) + diof = diophantine(10*x**2 + 5*x*y - 3*y) + assert diof == {(0, 0)} + + +def check_solutions(eq): + """ + Determines whether solutions returned by diophantine() satisfy the original + equation. Hope to generalize this so we can remove functions like check_ternay_quadratic, + check_solutions_normal, check_solutions() + """ + s = diophantine(eq) + + factors = Mul.make_args(eq) + + var = list(eq.free_symbols) + var.sort(key=default_sort_key) + + while s: + solution = s.pop() + for f in factors: + if diop_simplify(f.subs(zip(var, solution))) == 0: + break + else: + return False + return True + + +def test_diopcoverage(): + eq = (2*x + y + 1)**2 + assert diop_solve(eq) == {(t_0, -2*t_0 - 1)} + eq = 2*x**2 + 6*x*y + 12*x + 4*y**2 + 18*y + 18 + assert diop_solve(eq) == {(t, -t - 3), (-2*t - 3, t)} + assert diop_quadratic(x + y**2 - 3) == {(-t**2 + 3, t)} + + assert diop_linear(x + y - 3) == (t_0, 3 - t_0) + + assert base_solution_linear(0, 1, 2, t=None) == (0, 0) + ans = (3*t - 1, -2*t + 1) + assert base_solution_linear(4, 8, 12, t) == ans + assert base_solution_linear(4, 8, 12, t=None) == tuple(_.subs(t, 0) for _ in ans) + + assert cornacchia(1, 1, 20) == set() + assert cornacchia(1, 1, 5) == {(2, 1)} + assert cornacchia(1, 2, 17) == {(3, 2)} + + raises(ValueError, lambda: reconstruct(4, 20, 1)) + + assert gaussian_reduce(4, 1, 3) == (1, 1) + eq = -w**2 - x**2 - y**2 + z**2 + + assert diop_general_pythagorean(eq) == \ + diop_general_pythagorean(-eq) == \ + (m1**2 + m2**2 - m3**2, 2*m1*m3, + 2*m2*m3, m1**2 + m2**2 + m3**2) + + assert len(check_param(S(3) + x/3, S(4) + x/2, S(2), [x])) == 0 + assert len(check_param(Rational(3, 2), S(4) + x, S(2), [x])) == 0 + assert len(check_param(S(4) + x, Rational(3, 2), S(2), [x])) == 0 + + assert _nint_or_floor(16, 10) == 2 + assert _odd(1) == (not _even(1)) == True + assert _odd(0) == (not _even(0)) == False + assert _remove_gcd(2, 4, 6) == (1, 2, 3) + raises(TypeError, lambda: _remove_gcd((2, 4, 6))) + assert sqf_normal(2*3**2*5, 2*5*11, 2*7**2*11) == \ + (11, 1, 5) + + # it's ok if these pass some day when the solvers are implemented + raises(NotImplementedError, lambda: diophantine(x**2 + y**2 + x*y + 2*y*z - 12)) + raises(NotImplementedError, lambda: diophantine(x**3 + y**2)) + assert diop_quadratic(x**2 + y**2 - 1**2 - 3**4) == \ + {(-9, -1), (-9, 1), (-1, -9), (-1, 9), (1, -9), (1, 9), (9, -1), (9, 1)} + + +def test_holzer(): + # if the input is good, don't let it diverge in holzer() + # (but see test_fail_holzer below) + assert holzer(2, 7, 13, 4, 79, 23) == (2, 7, 13) + + # None in uv condition met; solution is not Holzer reduced + # so this will hopefully change but is here for coverage + assert holzer(2, 6, 2, 1, 1, 10) == (2, 6, 2) + + raises(ValueError, lambda: holzer(2, 7, 14, 4, 79, 23)) + + +@XFAIL +def test_fail_holzer(): + eq = lambda x, y, z: a*x**2 + b*y**2 - c*z**2 + a, b, c = 4, 79, 23 + x, y, z = xyz = 26, 1, 11 + X, Y, Z = ans = 2, 7, 13 + assert eq(*xyz) == 0 + assert eq(*ans) == 0 + assert max(a*x**2, b*y**2, c*z**2) <= a*b*c + assert max(a*X**2, b*Y**2, c*Z**2) <= a*b*c + h = holzer(x, y, z, a, b, c) + assert h == ans # it would be nice to get the smaller soln + + +def test_issue_9539(): + assert diophantine(6*w + 9*y + 20*x - z) == \ + {(t_0, t_1, t_1 + t_2, 6*t_0 + 29*t_1 + 9*t_2)} + + +def test_issue_8943(): + assert diophantine( + 3*(x**2 + y**2 + z**2) - 14*(x*y + y*z + z*x)) == \ + {(0, 0, 0)} + + +def test_diop_sum_of_even_powers(): + eq = x**4 + y**4 + z**4 - 2673 + assert diop_solve(eq) == {(3, 6, 6), (2, 4, 7)} + assert diop_general_sum_of_even_powers(eq, 2) == {(3, 6, 6), (2, 4, 7)} + raises(NotImplementedError, lambda: diop_general_sum_of_even_powers(-eq, 2)) + neg = symbols('neg', negative=True) + eq = x**4 + y**4 + neg**4 - 2673 + assert diop_general_sum_of_even_powers(eq) == {(-3, 6, 6)} + assert diophantine(x**4 + y**4 + 2) == set() + assert diop_general_sum_of_even_powers(x**4 + y**4 - 2, limit=0) == set() + + +def test_sum_of_squares_powers(): + tru = {(0, 0, 1, 1, 11), (0, 0, 5, 7, 7), (0, 1, 3, 7, 8), (0, 1, 4, 5, 9), (0, 3, 4, 7, 7), (0, 3, 5, 5, 8), + (1, 1, 2, 6, 9), (1, 1, 6, 6, 7), (1, 2, 3, 3, 10), (1, 3, 4, 4, 9), (1, 5, 5, 6, 6), (2, 2, 3, 5, 9), + (2, 3, 5, 6, 7), (3, 3, 4, 5, 8)} + eq = u**2 + v**2 + x**2 + y**2 + z**2 - 123 + ans = diop_general_sum_of_squares(eq, oo) # allow oo to be used + assert len(ans) == 14 + assert ans == tru + + raises(ValueError, lambda: list(sum_of_squares(10, -1))) + assert list(sum_of_squares(1, 1)) == [(1,)] + assert list(sum_of_squares(1, 2)) == [] + assert list(sum_of_squares(1, 2, True)) == [(0, 1)] + assert list(sum_of_squares(-10, 2)) == [] + assert list(sum_of_squares(2, 3)) == [] + assert list(sum_of_squares(0, 3, True)) == [(0, 0, 0)] + assert list(sum_of_squares(0, 3)) == [] + assert list(sum_of_squares(4, 1)) == [(2,)] + assert list(sum_of_squares(5, 1)) == [] + assert list(sum_of_squares(50, 2)) == [(5, 5), (1, 7)] + assert list(sum_of_squares(11, 5, True)) == [ + (1, 1, 1, 2, 2), (0, 0, 1, 1, 3)] + assert list(sum_of_squares(8, 8)) == [(1, 1, 1, 1, 1, 1, 1, 1)] + + assert [len(list(sum_of_squares(i, 5, True))) for i in range(30)] == [ + 1, 1, 1, 1, 2, + 2, 1, 1, 2, 2, + 2, 2, 2, 3, 2, + 1, 3, 3, 3, 3, + 4, 3, 3, 2, 2, + 4, 4, 4, 4, 5] + assert [len(list(sum_of_squares(i, 5))) for i in range(30)] == [ + 0, 0, 0, 0, 0, + 1, 0, 0, 1, 0, + 0, 1, 0, 1, 1, + 0, 1, 1, 0, 1, + 2, 1, 1, 1, 1, + 1, 1, 1, 1, 3] + for i in range(30): + s1 = set(sum_of_squares(i, 5, True)) + assert not s1 or all(sum(j**2 for j in t) == i for t in s1) + s2 = set(sum_of_squares(i, 5)) + assert all(sum(j**2 for j in t) == i for t in s2) + + raises(ValueError, lambda: list(sum_of_powers(2, -1, 1))) + raises(ValueError, lambda: list(sum_of_powers(2, 1, -1))) + assert list(sum_of_powers(-2, 3, 2)) == [(-1, -1)] + assert list(sum_of_powers(-2, 4, 2)) == [] + assert list(sum_of_powers(2, 1, 1)) == [(2,)] + assert list(sum_of_powers(2, 1, 3, True)) == [(0, 0, 2), (0, 1, 1)] + assert list(sum_of_powers(5, 1, 2, True)) == [(0, 5), (1, 4), (2, 3)] + assert list(sum_of_powers(6, 2, 2)) == [] + assert list(sum_of_powers(3**5, 3, 1)) == [] + assert list(sum_of_powers(3**6, 3, 1)) == [(9,)] and (9**3 == 3**6) + assert list(sum_of_powers(2**1000, 5, 2)) == [] + + +def test__can_do_sum_of_squares(): + assert _can_do_sum_of_squares(3, -1) is False + assert _can_do_sum_of_squares(-3, 1) is False + assert _can_do_sum_of_squares(0, 1) + assert _can_do_sum_of_squares(4, 1) + assert _can_do_sum_of_squares(1, 2) + assert _can_do_sum_of_squares(2, 2) + assert _can_do_sum_of_squares(3, 2) is False + + +def test_diophantine_permute_sign(): + from sympy.abc import a, b, c, d, e + eq = a**4 + b**4 - (2**4 + 3**4) + base_sol = {(2, 3)} + assert diophantine(eq) == base_sol + complete_soln = set(signed_permutations(base_sol.pop())) + assert diophantine(eq, permute=True) == complete_soln + + eq = a**2 + b**2 + c**2 + d**2 + e**2 - 234 + assert len(diophantine(eq)) == 35 + assert len(diophantine(eq, permute=True)) == 62000 + soln = {(-1, -1), (-1, 2), (1, -2), (1, 1)} + assert diophantine(10*x**2 + 12*x*y + 12*y**2 - 34, permute=True) == soln + + +@XFAIL +def test_not_implemented(): + eq = x**2 + y**4 - 1**2 - 3**4 + assert diophantine(eq, syms=[x, y]) == {(9, 1), (1, 3)} + + +def test_issue_9538(): + eq = x - 3*y + 2 + assert diophantine(eq, syms=[y,x]) == {(t_0, 3*t_0 - 2)} + raises(TypeError, lambda: diophantine(eq, syms={y, x})) + + +def test_ternary_quadratic(): + # solution with 3 parameters + s = diophantine(2*x**2 + y**2 - 2*z**2) + p, q, r = ordered(S(s).free_symbols) + assert s == {( + p**2 - 2*q**2, + -2*p**2 + 4*p*q - 4*p*r - 4*q**2, + p**2 - 4*p*q + 2*q**2 - 4*q*r)} + # solution with Mul in solution + s = diophantine(x**2 + 2*y**2 - 2*z**2) + assert s == {(4*p*q, p**2 - 2*q**2, p**2 + 2*q**2)} + # solution with no Mul in solution + s = diophantine(2*x**2 + 2*y**2 - z**2) + assert s == {(2*p**2 - q**2, -2*p**2 + 4*p*q - q**2, + 4*p**2 - 4*p*q + 2*q**2)} + # reduced form when parametrized + s = diophantine(3*x**2 + 72*y**2 - 27*z**2) + assert s == {(24*p**2 - 9*q**2, 6*p*q, 8*p**2 + 3*q**2)} + assert parametrize_ternary_quadratic( + 3*x**2 + 2*y**2 - z**2 - 2*x*y + 5*y*z - 7*y*z) == ( + 2*p**2 - 2*p*q - q**2, 2*p**2 + 2*p*q - q**2, 2*p**2 - + 2*p*q + 3*q**2) + assert parametrize_ternary_quadratic( + 124*x**2 - 30*y**2 - 7729*z**2) == ( + -1410*p**2 - 363263*q**2, 2700*p**2 + 30916*p*q - + 695610*q**2, -60*p**2 + 5400*p*q + 15458*q**2) + + +def test_diophantine_solution_set(): + s1 = DiophantineSolutionSet([], []) + assert set(s1) == set() + assert s1.symbols == () + assert s1.parameters == () + raises(ValueError, lambda: s1.add((x,))) + assert list(s1.dict_iterator()) == [] + + s2 = DiophantineSolutionSet([x, y], [t, u]) + assert s2.symbols == (x, y) + assert s2.parameters == (t, u) + raises(ValueError, lambda: s2.add((1,))) + s2.add((3, 4)) + assert set(s2) == {(3, 4)} + s2.update((3, 4), (-1, u)) + assert set(s2) == {(3, 4), (-1, u)} + raises(ValueError, lambda: s1.update(s2)) + assert list(s2.dict_iterator()) == [{x: -1, y: u}, {x: 3, y: 4}] + + s3 = DiophantineSolutionSet([x, y, z], [t, u]) + assert len(s3.parameters) == 2 + s3.add((t**2 + u, t - u, 1)) + assert set(s3) == {(t**2 + u, t - u, 1)} + assert s3.subs(t, 2) == {(u + 4, 2 - u, 1)} + assert s3(2) == {(u + 4, 2 - u, 1)} + assert s3.subs({t: 7, u: 8}) == {(57, -1, 1)} + assert s3(7, 8) == {(57, -1, 1)} + assert s3.subs({t: 5}) == {(u + 25, 5 - u, 1)} + assert s3(5) == {(u + 25, 5 - u, 1)} + assert s3.subs(u, -3) == {(t**2 - 3, t + 3, 1)} + assert s3(None, -3) == {(t**2 - 3, t + 3, 1)} + assert s3.subs({t: 2, u: 8}) == {(12, -6, 1)} + assert s3(2, 8) == {(12, -6, 1)} + assert s3.subs({t: 5, u: -3}) == {(22, 8, 1)} + assert s3(5, -3) == {(22, 8, 1)} + raises(TypeError, lambda: s3.subs(x=1)) + raises(TypeError, lambda: s3.subs(1, 2, 3)) + raises(ValueError, lambda: s3.add(())) + raises(ValueError, lambda: s3.add((1, 2, 3, 4))) + raises(ValueError, lambda: s3.add((1, 2))) + raises(ValueError, lambda: s3(1, 2, 3)) + raises(TypeError, lambda: s3(t=1)) + + s4 = DiophantineSolutionSet([x, y], [t, u]) + s4.add((t, 11*t)) + s4.add((-t, 22*t)) + assert s4(0, 0) == {(0, 0)} + + +def test_quadratic_parameter_passing(): + eq = -33*x*y + 3*y**2 + solution = BinaryQuadratic(eq).solve(parameters=[t, u]) + # test that parameters are passed all the way to the final solution + assert solution == {(t, 11*t), (t, -22*t)} + assert solution(0, 0) == {(0, 0)} + +def test_issue_18628(): + eq1 = x**2 - 15*x + y**2 - 8*y + sol = diophantine(eq1) + assert sol == {(15, 0), (15, 8), (-1, 4), (0, 0), (0, 8), (16, 4)} + eq2 = 2*x**2 - 9*x + 4*y**2 - 8*y + 14 + sol = diophantine(eq2) + assert sol == {(2, 1)} diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/inequalities.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/inequalities.py new file mode 100644 index 0000000000000000000000000000000000000000..f50f7a7572ff25e8f48a4214d7b0c5ec6b5b35f3 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/inequalities.py @@ -0,0 +1,986 @@ +"""Tools for solving inequalities and systems of inequalities. """ +import itertools + +from sympy.calculus.util import (continuous_domain, periodicity, + function_range) +from sympy.core import sympify +from sympy.core.exprtools import factor_terms +from sympy.core.relational import Relational, Lt, Ge, Eq +from sympy.core.symbol import Symbol, Dummy +from sympy.sets.sets import Interval, FiniteSet, Union, Intersection +from sympy.core.singleton import S +from sympy.core.function import expand_mul +from sympy.functions.elementary.complexes import Abs +from sympy.logic import And +from sympy.polys import Poly, PolynomialError, parallel_poly_from_expr +from sympy.polys.polyutils import _nsort +from sympy.solvers.solveset import solvify, solveset +from sympy.utilities.iterables import sift, iterable +from sympy.utilities.misc import filldedent + + +def solve_poly_inequality(poly, rel): + """Solve a polynomial inequality with rational coefficients. + + Examples + ======== + + >>> from sympy import solve_poly_inequality, Poly + >>> from sympy.abc import x + + >>> solve_poly_inequality(Poly(x, x, domain='ZZ'), '==') + [{0}] + + >>> solve_poly_inequality(Poly(x**2 - 1, x, domain='ZZ'), '!=') + [Interval.open(-oo, -1), Interval.open(-1, 1), Interval.open(1, oo)] + + >>> solve_poly_inequality(Poly(x**2 - 1, x, domain='ZZ'), '==') + [{-1}, {1}] + + See Also + ======== + solve_poly_inequalities + """ + if not isinstance(poly, Poly): + raise ValueError( + 'For efficiency reasons, `poly` should be a Poly instance') + if poly.as_expr().is_number: + t = Relational(poly.as_expr(), 0, rel) + if t is S.true: + return [S.Reals] + elif t is S.false: + return [S.EmptySet] + else: + raise NotImplementedError( + "could not determine truth value of %s" % t) + + reals, intervals = poly.real_roots(multiple=False), [] + + if rel == '==': + for root, _ in reals: + interval = Interval(root, root) + intervals.append(interval) + elif rel == '!=': + left = S.NegativeInfinity + + for right, _ in reals + [(S.Infinity, 1)]: + interval = Interval(left, right, True, True) + intervals.append(interval) + left = right + else: + if poly.LC() > 0: + sign = +1 + else: + sign = -1 + + eq_sign, equal = None, False + + if rel == '>': + eq_sign = +1 + elif rel == '<': + eq_sign = -1 + elif rel == '>=': + eq_sign, equal = +1, True + elif rel == '<=': + eq_sign, equal = -1, True + else: + raise ValueError("'%s' is not a valid relation" % rel) + + right, right_open = S.Infinity, True + + for left, multiplicity in reversed(reals): + if multiplicity % 2: + if sign == eq_sign: + intervals.insert( + 0, Interval(left, right, not equal, right_open)) + + sign, right, right_open = -sign, left, not equal + else: + if sign == eq_sign and not equal: + intervals.insert( + 0, Interval(left, right, True, right_open)) + right, right_open = left, True + elif sign != eq_sign and equal: + intervals.insert(0, Interval(left, left)) + + if sign == eq_sign: + intervals.insert( + 0, Interval(S.NegativeInfinity, right, True, right_open)) + + return intervals + + +def solve_poly_inequalities(polys): + """Solve polynomial inequalities with rational coefficients. + + Examples + ======== + + >>> from sympy import Poly + >>> from sympy.solvers.inequalities import solve_poly_inequalities + >>> from sympy.abc import x + >>> solve_poly_inequalities((( + ... Poly(x**2 - 3), ">"), ( + ... Poly(-x**2 + 1), ">"))) + Union(Interval.open(-oo, -sqrt(3)), Interval.open(-1, 1), Interval.open(sqrt(3), oo)) + """ + return Union(*[s for p in polys for s in solve_poly_inequality(*p)]) + + +def solve_rational_inequalities(eqs): + """Solve a system of rational inequalities with rational coefficients. + + Examples + ======== + + >>> from sympy.abc import x + >>> from sympy import solve_rational_inequalities, Poly + + >>> solve_rational_inequalities([[ + ... ((Poly(-x + 1), Poly(1, x)), '>='), + ... ((Poly(-x + 1), Poly(1, x)), '<=')]]) + {1} + + >>> solve_rational_inequalities([[ + ... ((Poly(x), Poly(1, x)), '!='), + ... ((Poly(-x + 1), Poly(1, x)), '>=')]]) + Union(Interval.open(-oo, 0), Interval.Lopen(0, 1)) + + See Also + ======== + solve_poly_inequality + """ + result = S.EmptySet + + for _eqs in eqs: + if not _eqs: + continue + + global_intervals = [Interval(S.NegativeInfinity, S.Infinity)] + + for (numer, denom), rel in _eqs: + numer_intervals = solve_poly_inequality(numer*denom, rel) + denom_intervals = solve_poly_inequality(denom, '==') + + intervals = [] + + for numer_interval, global_interval in itertools.product( + numer_intervals, global_intervals): + interval = numer_interval.intersect(global_interval) + + if interval is not S.EmptySet: + intervals.append(interval) + + global_intervals = intervals + + intervals = [] + + for global_interval in global_intervals: + for denom_interval in denom_intervals: + global_interval -= denom_interval + + if global_interval is not S.EmptySet: + intervals.append(global_interval) + + global_intervals = intervals + + if not global_intervals: + break + + for interval in global_intervals: + result = result.union(interval) + + return result + + +def reduce_rational_inequalities(exprs, gen, relational=True): + """Reduce a system of rational inequalities with rational coefficients. + + Examples + ======== + + >>> from sympy import Symbol + >>> from sympy.solvers.inequalities import reduce_rational_inequalities + + >>> x = Symbol('x', real=True) + + >>> reduce_rational_inequalities([[x**2 <= 0]], x) + Eq(x, 0) + + >>> reduce_rational_inequalities([[x + 2 > 0]], x) + -2 < x + >>> reduce_rational_inequalities([[(x + 2, ">")]], x) + -2 < x + >>> reduce_rational_inequalities([[x + 2]], x) + Eq(x, -2) + + This function find the non-infinite solution set so if the unknown symbol + is declared as extended real rather than real then the result may include + finiteness conditions: + + >>> y = Symbol('y', extended_real=True) + >>> reduce_rational_inequalities([[y + 2 > 0]], y) + (-2 < y) & (y < oo) + """ + exact = True + eqs = [] + solution = S.EmptySet # add pieces for each group + for _exprs in exprs: + if not _exprs: + continue + _eqs = [] + _sol = S.Reals + for expr in _exprs: + if isinstance(expr, tuple): + expr, rel = expr + else: + if expr.is_Relational: + expr, rel = expr.lhs - expr.rhs, expr.rel_op + else: + rel = '==' + + if expr is S.true: + numer, denom, rel = S.Zero, S.One, '==' + elif expr is S.false: + numer, denom, rel = S.One, S.One, '==' + else: + numer, denom = expr.together().as_numer_denom() + + try: + (numer, denom), opt = parallel_poly_from_expr( + (numer, denom), gen) + except PolynomialError: + raise PolynomialError(filldedent(''' + only polynomials and rational functions are + supported in this context. + ''')) + + if not opt.domain.is_Exact: + numer, denom, exact = numer.to_exact(), denom.to_exact(), False + + domain = opt.domain.get_exact() + + if not (domain.is_ZZ or domain.is_QQ): + expr = numer/denom + expr = Relational(expr, 0, rel) + _sol &= solve_univariate_inequality(expr, gen, relational=False) + else: + _eqs.append(((numer, denom), rel)) + + if _eqs: + _sol &= solve_rational_inequalities([_eqs]) + exclude = solve_rational_inequalities([[((d, d.one), '==') + for i in eqs for ((n, d), _) in i if d.has(gen)]]) + _sol -= exclude + + solution |= _sol + + if not exact and solution: + solution = solution.evalf() + + if relational: + solution = solution.as_relational(gen) + + return solution + + +def reduce_abs_inequality(expr, rel, gen): + """Reduce an inequality with nested absolute values. + + Examples + ======== + + >>> from sympy import reduce_abs_inequality, Abs, Symbol + >>> x = Symbol('x', real=True) + + >>> reduce_abs_inequality(Abs(x - 5) - 3, '<', x) + (2 < x) & (x < 8) + + >>> reduce_abs_inequality(Abs(x + 2)*3 - 13, '<', x) + (-19/3 < x) & (x < 7/3) + + See Also + ======== + + reduce_abs_inequalities + """ + if gen.is_extended_real is False: + raise TypeError(filldedent(''' + Cannot solve inequalities with absolute values containing + non-real variables. + ''')) + + def _bottom_up_scan(expr): + exprs = [] + + if expr.is_Add or expr.is_Mul: + op = expr.func + + for arg in expr.args: + _exprs = _bottom_up_scan(arg) + + if not exprs: + exprs = _exprs + else: + exprs = [(op(expr, _expr), conds + _conds) for (expr, conds), (_expr, _conds) in + itertools.product(exprs, _exprs)] + elif expr.is_Pow: + n = expr.exp + if not n.is_Integer: + raise ValueError("Only Integer Powers are allowed on Abs.") + + exprs.extend((expr**n, conds) for expr, conds in _bottom_up_scan(expr.base)) + elif isinstance(expr, Abs): + _exprs = _bottom_up_scan(expr.args[0]) + + for expr, conds in _exprs: + exprs.append(( expr, conds + [Ge(expr, 0)])) + exprs.append((-expr, conds + [Lt(expr, 0)])) + else: + exprs = [(expr, [])] + + return exprs + + mapping = {'<': '>', '<=': '>='} + inequalities = [] + + for expr, conds in _bottom_up_scan(expr): + if rel not in mapping.keys(): + expr = Relational( expr, 0, rel) + else: + expr = Relational(-expr, 0, mapping[rel]) + + inequalities.append([expr] + conds) + + return reduce_rational_inequalities(inequalities, gen) + + +def reduce_abs_inequalities(exprs, gen): + """Reduce a system of inequalities with nested absolute values. + + Examples + ======== + + >>> from sympy import reduce_abs_inequalities, Abs, Symbol + >>> x = Symbol('x', extended_real=True) + + >>> reduce_abs_inequalities([(Abs(3*x - 5) - 7, '<'), + ... (Abs(x + 25) - 13, '>')], x) + (-2/3 < x) & (x < 4) & (((-oo < x) & (x < -38)) | ((-12 < x) & (x < oo))) + + >>> reduce_abs_inequalities([(Abs(x - 4) + Abs(3*x - 5) - 7, '<')], x) + (1/2 < x) & (x < 4) + + See Also + ======== + + reduce_abs_inequality + """ + return And(*[ reduce_abs_inequality(expr, rel, gen) + for expr, rel in exprs ]) + + +def solve_univariate_inequality(expr, gen, relational=True, domain=S.Reals, continuous=False): + """Solves a real univariate inequality. + + Parameters + ========== + + expr : Relational + The target inequality + gen : Symbol + The variable for which the inequality is solved + relational : bool + A Relational type output is expected or not + domain : Set + The domain over which the equation is solved + continuous: bool + True if expr is known to be continuous over the given domain + (and so continuous_domain() does not need to be called on it) + + Raises + ====== + + NotImplementedError + The solution of the inequality cannot be determined due to limitation + in :func:`sympy.solvers.solveset.solvify`. + + Notes + ===== + + Currently, we cannot solve all the inequalities due to limitations in + :func:`sympy.solvers.solveset.solvify`. Also, the solution returned for trigonometric inequalities + are restricted in its periodic interval. + + See Also + ======== + + sympy.solvers.solveset.solvify: solver returning solveset solutions with solve's output API + + Examples + ======== + + >>> from sympy import solve_univariate_inequality, Symbol, sin, Interval, S + >>> x = Symbol('x') + + >>> solve_univariate_inequality(x**2 >= 4, x) + ((2 <= x) & (x < oo)) | ((-oo < x) & (x <= -2)) + + >>> solve_univariate_inequality(x**2 >= 4, x, relational=False) + Union(Interval(-oo, -2), Interval(2, oo)) + + >>> domain = Interval(0, S.Infinity) + >>> solve_univariate_inequality(x**2 >= 4, x, False, domain) + Interval(2, oo) + + >>> solve_univariate_inequality(sin(x) > 0, x, relational=False) + Interval.open(0, pi) + + """ + from sympy.solvers.solvers import denoms + + if domain.is_subset(S.Reals) is False: + raise NotImplementedError(filldedent(''' + Inequalities in the complex domain are + not supported. Try the real domain by + setting domain=S.Reals''')) + elif domain is not S.Reals: + rv = solve_univariate_inequality( + expr, gen, relational=False, continuous=continuous).intersection(domain) + if relational: + rv = rv.as_relational(gen) + return rv + else: + pass # continue with attempt to solve in Real domain + + # This keeps the function independent of the assumptions about `gen`. + # `solveset` makes sure this function is called only when the domain is + # real. + _gen = gen + _domain = domain + if gen.is_extended_real is False: + rv = S.EmptySet + return rv if not relational else rv.as_relational(_gen) + elif gen.is_extended_real is None: + gen = Dummy('gen', extended_real=True) + try: + expr = expr.xreplace({_gen: gen}) + except TypeError: + raise TypeError(filldedent(''' + When gen is real, the relational has a complex part + which leads to an invalid comparison like I < 0. + ''')) + + rv = None + + if expr is S.true: + rv = domain + + elif expr is S.false: + rv = S.EmptySet + + else: + e = expr.lhs - expr.rhs + period = periodicity(e, gen) + if period == S.Zero: + e = expand_mul(e) + const = expr.func(e, 0) + if const is S.true: + rv = domain + elif const is S.false: + rv = S.EmptySet + elif period is not None: + frange = function_range(e, gen, domain) + + rel = expr.rel_op + if rel in ('<', '<='): + if expr.func(frange.sup, 0): + rv = domain + elif not expr.func(frange.inf, 0): + rv = S.EmptySet + + elif rel in ('>', '>='): + if expr.func(frange.inf, 0): + rv = domain + elif not expr.func(frange.sup, 0): + rv = S.EmptySet + + inf, sup = domain.inf, domain.sup + if sup - inf is S.Infinity: + domain = Interval(0, period, False, True).intersect(_domain) + _domain = domain + + if rv is None: + n, d = e.as_numer_denom() + try: + if gen not in n.free_symbols and len(e.free_symbols) > 1: + raise ValueError + # this might raise ValueError on its own + # or it might give None... + solns = solvify(e, gen, domain) + if solns is None: + # in which case we raise ValueError + raise ValueError + except (ValueError, NotImplementedError): + # replace gen with generic x since it's + # univariate anyway + raise NotImplementedError(filldedent(''' + The inequality, %s, cannot be solved using + solve_univariate_inequality. + ''' % expr.subs(gen, Symbol('x')))) + + expanded_e = expand_mul(e) + def valid(x): + # this is used to see if gen=x satisfies the + # relational by substituting it into the + # expanded form and testing against 0, e.g. + # if expr = x*(x + 1) < 2 then e = x*(x + 1) - 2 + # and expanded_e = x**2 + x - 2; the test is + # whether a given value of x satisfies + # x**2 + x - 2 < 0 + # + # expanded_e, expr and gen used from enclosing scope + v = expanded_e.subs(gen, expand_mul(x)) + try: + r = expr.func(v, 0) + except TypeError: + r = S.false + if r in (S.true, S.false): + return r + if v.is_extended_real is False: + return S.false + else: + v = v.n(2) + if v.is_comparable: + return expr.func(v, 0) + # not comparable or couldn't be evaluated + raise NotImplementedError( + 'relationship did not evaluate: %s' % r) + + singularities = [] + for d in denoms(expr, gen): + singularities.extend(solvify(d, gen, domain)) + if not continuous: + domain = continuous_domain(expanded_e, gen, domain) + + include_x = '=' in expr.rel_op and expr.rel_op != '!=' + + try: + discontinuities = set(domain.boundary - + FiniteSet(domain.inf, domain.sup)) + # remove points that are not between inf and sup of domain + critical_points = FiniteSet(*(solns + singularities + list( + discontinuities))).intersection( + Interval(domain.inf, domain.sup, + domain.inf not in domain, domain.sup not in domain)) + if all(r.is_number for r in critical_points): + reals = _nsort(critical_points, separated=True)[0] + else: + sifted = sift(critical_points, lambda x: x.is_extended_real) + if sifted[None]: + # there were some roots that weren't known + # to be real + raise NotImplementedError + try: + reals = sifted[True] + if len(reals) > 1: + reals = sorted(reals) + except TypeError: + raise NotImplementedError + except NotImplementedError: + raise NotImplementedError('sorting of these roots is not supported') + + # If expr contains imaginary coefficients, only take real + # values of x for which the imaginary part is 0 + make_real = S.Reals + if (coeffI := expanded_e.coeff(S.ImaginaryUnit)) != S.Zero: + check = True + im_sol = FiniteSet() + try: + a = solveset(coeffI, gen, domain) + if not isinstance(a, Interval): + for z in a: + if z not in singularities and valid(z) and z.is_extended_real: + im_sol += FiniteSet(z) + else: + start, end = a.inf, a.sup + for z in _nsort(critical_points + FiniteSet(end)): + valid_start = valid(start) + if start != end: + valid_z = valid(z) + pt = _pt(start, z) + if pt not in singularities and pt.is_extended_real and valid(pt): + if valid_start and valid_z: + im_sol += Interval(start, z) + elif valid_start: + im_sol += Interval.Ropen(start, z) + elif valid_z: + im_sol += Interval.Lopen(start, z) + else: + im_sol += Interval.open(start, z) + start = z + for s in singularities: + im_sol -= FiniteSet(s) + except (TypeError): + im_sol = S.Reals + check = False + + if im_sol is S.EmptySet: + raise ValueError(filldedent(''' + %s contains imaginary parts which cannot be + made 0 for any value of %s satisfying the + inequality, leading to relations like I < 0. + ''' % (expr.subs(gen, _gen), _gen))) + + make_real = make_real.intersect(im_sol) + + sol_sets = [S.EmptySet] + + start = domain.inf + if start in domain and valid(start) and start.is_finite: + sol_sets.append(FiniteSet(start)) + + for x in reals: + end = x + + if valid(_pt(start, end)): + sol_sets.append(Interval(start, end, True, True)) + + if x in singularities: + singularities.remove(x) + else: + if x in discontinuities: + discontinuities.remove(x) + _valid = valid(x) + else: # it's a solution + _valid = include_x + if _valid: + sol_sets.append(FiniteSet(x)) + + start = end + + end = domain.sup + if end in domain and valid(end) and end.is_finite: + sol_sets.append(FiniteSet(end)) + + if valid(_pt(start, end)): + sol_sets.append(Interval.open(start, end)) + + if coeffI != S.Zero and check: + rv = (make_real).intersect(_domain) + else: + rv = Intersection( + (Union(*sol_sets)), make_real, _domain).subs(gen, _gen) + + return rv if not relational else rv.as_relational(_gen) + + +def _pt(start, end): + """Return a point between start and end""" + if not start.is_infinite and not end.is_infinite: + pt = (start + end)/2 + elif start.is_infinite and end.is_infinite: + pt = S.Zero + else: + if (start.is_infinite and start.is_extended_positive is None or + end.is_infinite and end.is_extended_positive is None): + raise ValueError('cannot proceed with unsigned infinite values') + if (end.is_infinite and end.is_extended_negative or + start.is_infinite and start.is_extended_positive): + start, end = end, start + # if possible, use a multiple of self which has + # better behavior when checking assumptions than + # an expression obtained by adding or subtracting 1 + if end.is_infinite: + if start.is_extended_positive: + pt = start*2 + elif start.is_extended_negative: + pt = start*S.Half + else: + pt = start + 1 + elif start.is_infinite: + if end.is_extended_positive: + pt = end*S.Half + elif end.is_extended_negative: + pt = end*2 + else: + pt = end - 1 + return pt + + +def _solve_inequality(ie, s, linear=False): + """Return the inequality with s isolated on the left, if possible. + If the relationship is non-linear, a solution involving And or Or + may be returned. False or True are returned if the relationship + is never True or always True, respectively. + + If `linear` is True (default is False) an `s`-dependent expression + will be isolated on the left, if possible + but it will not be solved for `s` unless the expression is linear + in `s`. Furthermore, only "safe" operations which do not change the + sense of the relationship are applied: no division by an unsigned + value is attempted unless the relationship involves Eq or Ne and + no division by a value not known to be nonzero is ever attempted. + + Examples + ======== + + >>> from sympy import Eq, Symbol + >>> from sympy.solvers.inequalities import _solve_inequality as f + >>> from sympy.abc import x, y + + For linear expressions, the symbol can be isolated: + + >>> f(x - 2 < 0, x) + x < 2 + >>> f(-x - 6 < x, x) + x > -3 + + Sometimes nonlinear relationships will be False + + >>> f(x**2 + 4 < 0, x) + False + + Or they may involve more than one region of values: + + >>> f(x**2 - 4 < 0, x) + (-2 < x) & (x < 2) + + To restrict the solution to a relational, set linear=True + and only the x-dependent portion will be isolated on the left: + + >>> f(x**2 - 4 < 0, x, linear=True) + x**2 < 4 + + Division of only nonzero quantities is allowed, so x cannot + be isolated by dividing by y: + + >>> y.is_nonzero is None # it is unknown whether it is 0 or not + True + >>> f(x*y < 1, x) + x*y < 1 + + And while an equality (or inequality) still holds after dividing by a + non-zero quantity + + >>> nz = Symbol('nz', nonzero=True) + >>> f(Eq(x*nz, 1), x) + Eq(x, 1/nz) + + the sign must be known for other inequalities involving > or <: + + >>> f(x*nz <= 1, x) + nz*x <= 1 + >>> p = Symbol('p', positive=True) + >>> f(x*p <= 1, x) + x <= 1/p + + When there are denominators in the original expression that + are removed by expansion, conditions for them will be returned + as part of the result: + + >>> f(x < x*(2/x - 1), x) + (x < 1) & Ne(x, 0) + """ + from sympy.solvers.solvers import denoms + if s not in ie.free_symbols: + return ie + if ie.rhs == s: + ie = ie.reversed + if ie.lhs == s and s not in ie.rhs.free_symbols: + return ie + + def classify(ie, s, i): + # return True or False if ie evaluates when substituting s with + # i else None (if unevaluated) or NaN (when there is an error + # in evaluating) + try: + v = ie.subs(s, i) + if v is S.NaN: + return v + elif v not in (True, False): + return + return v + except TypeError: + return S.NaN + + rv = None + oo = S.Infinity + expr = ie.lhs - ie.rhs + try: + p = Poly(expr, s) + if p.degree() == 0: + rv = ie.func(p.as_expr(), 0) + elif not linear and p.degree() > 1: + # handle in except clause + raise NotImplementedError + except (PolynomialError, NotImplementedError): + if not linear: + try: + rv = reduce_rational_inequalities([[ie]], s) + except PolynomialError: + rv = solve_univariate_inequality(ie, s) + # remove restrictions wrt +/-oo that may have been + # applied when using sets to simplify the relationship + okoo = classify(ie, s, oo) + if okoo is S.true and classify(rv, s, oo) is S.false: + rv = rv.subs(s < oo, True) + oknoo = classify(ie, s, -oo) + if (oknoo is S.true and + classify(rv, s, -oo) is S.false): + rv = rv.subs(-oo < s, True) + rv = rv.subs(s > -oo, True) + if rv is S.true: + rv = (s <= oo) if okoo is S.true else (s < oo) + if oknoo is not S.true: + rv = And(-oo < s, rv) + else: + p = Poly(expr) + + conds = [] + if rv is None: + e = p.as_expr() # this is in expanded form + # Do a safe inversion of e, moving non-s terms + # to the rhs and dividing by a nonzero factor if + # the relational is Eq/Ne; for other relationals + # the sign must also be positive or negative + rhs = 0 + b, ax = e.as_independent(s, as_Add=True) + e -= b + rhs -= b + ef = factor_terms(e) + a, e = ef.as_independent(s, as_Add=False) + if (a.is_zero != False or # don't divide by potential 0 + a.is_negative == + a.is_positive is None and # if sign is not known then + ie.rel_op not in ('!=', '==')): # reject if not Eq/Ne + e = ef + a = S.One + rhs /= a + if a.is_positive: + rv = ie.func(e, rhs) + else: + rv = ie.reversed.func(e, rhs) + + # return conditions under which the value is + # valid, too. + beginning_denoms = denoms(ie.lhs) | denoms(ie.rhs) + current_denoms = denoms(rv) + for d in beginning_denoms - current_denoms: + c = _solve_inequality(Eq(d, 0), s, linear=linear) + if isinstance(c, Eq) and c.lhs == s: + if classify(rv, s, c.rhs) is S.true: + # rv is permitting this value but it shouldn't + conds.append(~c) + for i in (-oo, oo): + if (classify(rv, s, i) is S.true and + classify(ie, s, i) is not S.true): + conds.append(s < i if i is oo else i < s) + + conds.append(rv) + return And(*conds) + + +def _reduce_inequalities(inequalities, symbols): + # helper for reduce_inequalities + + poly_part, abs_part = {}, {} + other = [] + + for inequality in inequalities: + + expr, rel = inequality.lhs, inequality.rel_op # rhs is 0 + + # check for gens using atoms which is more strict than free_symbols to + # guard against EX domain which won't be handled by + # reduce_rational_inequalities + gens = expr.atoms(Symbol) + + if len(gens) == 1: + gen = gens.pop() + else: + common = expr.free_symbols & symbols + if len(common) == 1: + gen = common.pop() + other.append(_solve_inequality(Relational(expr, 0, rel), gen)) + continue + else: + raise NotImplementedError(filldedent(''' + inequality has more than one symbol of interest. + ''')) + + if expr.is_polynomial(gen): + poly_part.setdefault(gen, []).append((expr, rel)) + else: + components = expr.find(lambda u: + u.has(gen) and ( + u.is_Function or u.is_Pow and not u.exp.is_Integer)) + if components and all(isinstance(i, Abs) for i in components): + abs_part.setdefault(gen, []).append((expr, rel)) + else: + other.append(_solve_inequality(Relational(expr, 0, rel), gen)) + + poly_reduced = [reduce_rational_inequalities([exprs], gen) for gen, exprs in poly_part.items()] + abs_reduced = [reduce_abs_inequalities(exprs, gen) for gen, exprs in abs_part.items()] + + return And(*(poly_reduced + abs_reduced + other)) + + +def reduce_inequalities(inequalities, symbols=[]): + """Reduce a system of inequalities with rational coefficients. + + Examples + ======== + + >>> from sympy.abc import x, y + >>> from sympy import reduce_inequalities + + >>> reduce_inequalities(0 <= x + 3, []) + (-3 <= x) & (x < oo) + + >>> reduce_inequalities(0 <= x + y*2 - 1, [x]) + (x < oo) & (x >= 1 - 2*y) + """ + if not iterable(inequalities): + inequalities = [inequalities] + inequalities = [sympify(i) for i in inequalities] + + gens = set().union(*[i.free_symbols for i in inequalities]) + + if not iterable(symbols): + symbols = [symbols] + symbols = (set(symbols) or gens) & gens + if any(i.is_extended_real is False for i in symbols): + raise TypeError(filldedent(''' + inequalities cannot contain symbols that are not real. + ''')) + + # make vanilla symbol real + recast = {i: Dummy(i.name, extended_real=True) + for i in gens if i.is_extended_real is None} + inequalities = [i.xreplace(recast) for i in inequalities] + symbols = {i.xreplace(recast) for i in symbols} + + # prefilter + keep = [] + for i in inequalities: + if isinstance(i, Relational): + i = i.func(i.lhs.as_expr() - i.rhs.as_expr(), 0) + elif i not in (True, False): + i = Eq(i, 0) + if i == True: + continue + elif i == False: + return S.false + if i.lhs.is_number: + raise NotImplementedError( + "could not determine truth value of %s" % i) + keep.append(i) + inequalities = keep + del keep + + # solve system + rv = _reduce_inequalities(inequalities, symbols) + + # restore original symbols and return + return rv.xreplace({v: k for k, v in recast.items()}) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..2b543425251dea6380a1860279cb6d636f3dd629 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/__init__.py @@ -0,0 +1,16 @@ +from .ode import (allhints, checkinfsol, classify_ode, + constantsimp, dsolve, homogeneous_order) + +from .lie_group import infinitesimals + +from .subscheck import checkodesol + +from .systems import (canonical_odes, linear_ode_to_matrix, + linodesolve) + + +__all__ = [ + 'allhints', 'checkinfsol', 'checkodesol', 'classify_ode', 'constantsimp', + 'dsolve', 'homogeneous_order', 'infinitesimals', 'canonical_odes', 'linear_ode_to_matrix', + 'linodesolve' +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/hypergeometric.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/hypergeometric.py new file mode 100644 index 0000000000000000000000000000000000000000..5699d2418058acaf48d1e4f87f6635a7b1f7284c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/hypergeometric.py @@ -0,0 +1,272 @@ +r''' +This module contains the implementation of the 2nd_hypergeometric hint for +dsolve. This is an incomplete implementation of the algorithm described in [1]. +The algorithm solves 2nd order linear ODEs of the form + +.. math:: y'' + A(x) y' + B(x) y = 0\text{,} + +where `A` and `B` are rational functions. The algorithm should find any +solution of the form + +.. math:: y = P(x) _pF_q(..; ..;\frac{\alpha x^k + \beta}{\gamma x^k + \delta})\text{,} + +where pFq is any of 2F1, 1F1 or 0F1 and `P` is an "arbitrary function". +Currently only the 2F1 case is implemented in SymPy but the other cases are +described in the paper and could be implemented in future (contributions +welcome!). + +References +========== + +.. [1] L. Chan, E.S. Cheb-Terrab, Non-Liouvillian solutions for second order + linear ODEs, (2004). + https://arxiv.org/abs/math-ph/0402063 +''' + +from sympy.core import S, Pow +from sympy.core.function import expand +from sympy.core.relational import Eq +from sympy.core.symbol import Symbol, Wild +from sympy.functions import exp, sqrt, hyper +from sympy.integrals import Integral +from sympy.polys import roots, gcd +from sympy.polys.polytools import cancel, factor +from sympy.simplify import collect, simplify, logcombine # type: ignore +from sympy.simplify.powsimp import powdenest +from sympy.solvers.ode.ode import get_numbered_constants + + +def match_2nd_hypergeometric(eq, func): + x = func.args[0] + df = func.diff(x) + a3 = Wild('a3', exclude=[func, func.diff(x), func.diff(x, 2)]) + b3 = Wild('b3', exclude=[func, func.diff(x), func.diff(x, 2)]) + c3 = Wild('c3', exclude=[func, func.diff(x), func.diff(x, 2)]) + deq = a3*(func.diff(x, 2)) + b3*df + c3*func + r = collect(eq, + [func.diff(x, 2), func.diff(x), func]).match(deq) + if r: + if not all(val.is_polynomial() for val in r.values()): + n, d = eq.as_numer_denom() + eq = expand(n) + r = collect(eq, [func.diff(x, 2), func.diff(x), func]).match(deq) + + if r and r[a3]!=0: + A = cancel(r[b3]/r[a3]) + B = cancel(r[c3]/r[a3]) + return [A, B] + else: + return [] + + +def equivalence_hypergeometric(A, B, func): + # This method for finding the equivalence is only for 2F1 type. + # We can extend it for 1F1 and 0F1 type also. + x = func.args[0] + + # making given equation in normal form + I1 = factor(cancel(A.diff(x)/2 + A**2/4 - B)) + + # computing shifted invariant(J1) of the equation + J1 = factor(cancel(x**2*I1 + S(1)/4)) + num, dem = J1.as_numer_denom() + num = powdenest(expand(num)) + dem = powdenest(expand(dem)) + # this function will compute the different powers of variable(x) in J1. + # then it will help in finding value of k. k is power of x such that we can express + # J1 = x**k * J0(x**k) then all the powers in J0 become integers. + def _power_counting(num): + _pow = {0} + for val in num: + if val.has(x): + if isinstance(val, Pow) and val.as_base_exp()[0] == x: + _pow.add(val.as_base_exp()[1]) + elif val == x: + _pow.add(val.as_base_exp()[1]) + else: + _pow.update(_power_counting(val.args)) + return _pow + + pow_num = _power_counting((num, )) + pow_dem = _power_counting((dem, )) + pow_dem.update(pow_num) + + _pow = pow_dem + k = gcd(_pow) + + # computing I0 of the given equation + I0 = powdenest(simplify(factor(((J1/k**2) - S(1)/4)/((x**k)**2))), force=True) + I0 = factor(cancel(powdenest(I0.subs(x, x**(S(1)/k)), force=True))) + + # Before this point I0, J1 might be functions of e.g. sqrt(x) but replacing + # x with x**(1/k) should result in I0 being a rational function of x or + # otherwise the hypergeometric solver cannot be used. Note that k can be a + # non-integer rational such as 2/7. + if not I0.is_rational_function(x): + return None + + num, dem = I0.as_numer_denom() + + max_num_pow = max(_power_counting((num, ))) + dem_args = dem.args + sing_point = [] + dem_pow = [] + # calculating singular point of I0. + for arg in dem_args: + if arg.has(x): + if isinstance(arg, Pow): + # (x-a)**n + dem_pow.append(arg.as_base_exp()[1]) + sing_point.append(list(roots(arg.as_base_exp()[0], x).keys())[0]) + else: + # (x-a) type + dem_pow.append(arg.as_base_exp()[1]) + sing_point.append(list(roots(arg, x).keys())[0]) + + dem_pow.sort() + # checking if equivalence is exists or not. + + if equivalence(max_num_pow, dem_pow) == "2F1": + return {'I0':I0, 'k':k, 'sing_point':sing_point, 'type':"2F1"} + else: + return None + + +def match_2nd_2F1_hypergeometric(I, k, sing_point, func): + x = func.args[0] + a = Wild("a") + b = Wild("b") + c = Wild("c") + t = Wild("t") + s = Wild("s") + r = Wild("r") + alpha = Wild("alpha") + beta = Wild("beta") + gamma = Wild("gamma") + delta = Wild("delta") + # I0 of the standard 2F1 equation. + I0 = ((a-b+1)*(a-b-1)*x**2 + 2*((1-a-b)*c + 2*a*b)*x + c*(c-2))/(4*x**2*(x-1)**2) + if sing_point != [0, 1]: + # If singular point is [0, 1] then we have standard equation. + eqs = [] + sing_eqs = [-beta/alpha, -delta/gamma, (delta-beta)/(alpha-gamma)] + # making equations for the finding the mobius transformation + for i in range(3): + if i>> from sympy import Function, Eq, pprint + >>> from sympy.abc import x, y + >>> xi, eta, h = map(Function, ['xi', 'eta', 'h']) + >>> h = h(x, y) # dy/dx = h + >>> eta = eta(x, y) + >>> xi = xi(x, y) + >>> genform = Eq(eta.diff(x) + (eta.diff(y) - xi.diff(x))*h + ... - (xi.diff(y))*h**2 - xi*(h.diff(x)) - eta*(h.diff(y)), 0) + >>> pprint(genform) + /d d \ d 2 d d d + |--(eta(x, y)) - --(xi(x, y))|*h(x, y) - eta(x, y)*--(h(x, y)) - h (x, y)*--(xi(x, y)) - xi(x, y)*--(h(x, y)) + --(eta(x, y)) = 0 + \dy dx / dy dy dx dx + + Solving the above mentioned PDE is not trivial, and can be solved only by + making intelligent assumptions for `\xi` and `\eta` (heuristics). Once an + infinitesimal is found, the attempt to find more heuristics stops. This is done to + optimise the speed of solving the differential equation. If a list of all the + infinitesimals is needed, ``hint`` should be flagged as ``all``, which gives + the complete list of infinitesimals. If the infinitesimals for a particular + heuristic needs to be found, it can be passed as a flag to ``hint``. + + Examples + ======== + + >>> from sympy import Function + >>> from sympy.solvers.ode.lie_group import infinitesimals + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = f(x).diff(x) - x**2*f(x) + >>> infinitesimals(eq) + [{eta(x, f(x)): exp(x**3/3), xi(x, f(x)): 0}] + + References + ========== + + - Solving differential equations by Symmetry Groups, + John Starrett, pp. 1 - pp. 14 + + """ + + if isinstance(eq, Equality): + eq = eq.lhs - eq.rhs + if not func: + eq, func = _preprocess(eq) + variables = func.args + if len(variables) != 1: + raise ValueError("ODE's have only one independent variable") + else: + x = variables[0] + if not order: + order = ode_order(eq, func) + if order != 1: + raise NotImplementedError("Infinitesimals for only " + "first order ODE's have been implemented") + else: + df = func.diff(x) + # Matching differential equation of the form a*df + b + a = Wild('a', exclude = [df]) + b = Wild('b', exclude = [df]) + if match: # Used by lie_group hint + h = match['h'] + y = match['y'] + else: + match = collect(expand(eq), df).match(a*df + b) + if match: + h = -simplify(match[b]/match[a]) + else: + try: + sol = solve(eq, df) + except NotImplementedError: + raise NotImplementedError("Infinitesimals for the " + "first order ODE could not be found") + else: + h = sol[0] # Find infinitesimals for one solution + y = Dummy("y") + h = h.subs(func, y) + + u = Dummy("u") + hx = h.diff(x) + hy = h.diff(y) + hinv = ((1/h).subs([(x, u), (y, x)])).subs(u, y) # Inverse ODE + match = {'h': h, 'func': func, 'hx': hx, 'hy': hy, 'y': y, 'hinv': hinv} + if hint == 'all': + xieta = [] + for heuristic in lie_heuristics: + function = globals()['lie_heuristic_' + heuristic] + inflist = function(match, comp=True) + if inflist: + xieta.extend([inf for inf in inflist if inf not in xieta]) + if xieta: + return xieta + else: + raise NotImplementedError("Infinitesimals could not be found for " + "the given ODE") + + elif hint == 'default': + for heuristic in lie_heuristics: + function = globals()['lie_heuristic_' + heuristic] + xieta = function(match, comp=False) + if xieta: + return xieta + + raise NotImplementedError("Infinitesimals could not be found for" + " the given ODE") + + elif hint not in lie_heuristics: + raise ValueError("Heuristic not recognized: " + hint) + + else: + function = globals()['lie_heuristic_' + hint] + xieta = function(match, comp=True) + if xieta: + return xieta + else: + raise ValueError("Infinitesimals could not be found using the" + " given heuristic") + + +def lie_heuristic_abaco1_simple(match, comp=False): + r""" + The first heuristic uses the following four sets of + assumptions on `\xi` and `\eta` + + .. math:: \xi = 0, \eta = f(x) + + .. math:: \xi = 0, \eta = f(y) + + .. math:: \xi = f(x), \eta = 0 + + .. math:: \xi = f(y), \eta = 0 + + The success of this heuristic is determined by algebraic factorisation. + For the first assumption `\xi = 0` and `\eta` to be a function of `x`, the PDE + + .. math:: \frac{\partial \eta}{\partial x} + (\frac{\partial \eta}{\partial y} + - \frac{\partial \xi}{\partial x})*h + - \frac{\partial \xi}{\partial y}*h^{2} + - \xi*\frac{\partial h}{\partial x} - \eta*\frac{\partial h}{\partial y} = 0 + + reduces to `f'(x) - f\frac{\partial h}{\partial y} = 0` + If `\frac{\partial h}{\partial y}` is a function of `x`, then this can usually + be integrated easily. A similar idea is applied to the other 3 assumptions as well. + + + References + ========== + + - E.S Cheb-Terrab, L.G.S Duarte and L.A,C.P da Mota, Computer Algebra + Solving of First Order ODEs Using Symmetry Methods, pp. 8 + + + """ + + xieta = [] + y = match['y'] + h = match['h'] + func = match['func'] + x = func.args[0] + hx = match['hx'] + hy = match['hy'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + hysym = hy.free_symbols + if y not in hysym: + try: + fx = exp(integrate(hy, x)) + except NotImplementedError: + pass + else: + inf = {xi: S.Zero, eta: fx} + if not comp: + return [inf] + if comp and inf not in xieta: + xieta.append(inf) + + factor = hy/h + facsym = factor.free_symbols + if x not in facsym: + try: + fy = exp(integrate(factor, y)) + except NotImplementedError: + pass + else: + inf = {xi: S.Zero, eta: fy.subs(y, func)} + if not comp: + return [inf] + if comp and inf not in xieta: + xieta.append(inf) + + factor = -hx/h + facsym = factor.free_symbols + if y not in facsym: + try: + fx = exp(integrate(factor, x)) + except NotImplementedError: + pass + else: + inf = {xi: fx, eta: S.Zero} + if not comp: + return [inf] + if comp and inf not in xieta: + xieta.append(inf) + + factor = -hx/(h**2) + facsym = factor.free_symbols + if x not in facsym: + try: + fy = exp(integrate(factor, y)) + except NotImplementedError: + pass + else: + inf = {xi: fy.subs(y, func), eta: S.Zero} + if not comp: + return [inf] + if comp and inf not in xieta: + xieta.append(inf) + + if xieta: + return xieta + +def lie_heuristic_abaco1_product(match, comp=False): + r""" + The second heuristic uses the following two assumptions on `\xi` and `\eta` + + .. math:: \eta = 0, \xi = f(x)*g(y) + + .. math:: \eta = f(x)*g(y), \xi = 0 + + The first assumption of this heuristic holds good if + `\frac{1}{h^{2}}\frac{\partial^2}{\partial x \partial y}\log(h)` is + separable in `x` and `y`, then the separated factors containing `x` + is `f(x)`, and `g(y)` is obtained by + + .. math:: e^{\int f\frac{\partial}{\partial x}\left(\frac{1}{f*h}\right)\,dy} + + provided `f\frac{\partial}{\partial x}\left(\frac{1}{f*h}\right)` is a function + of `y` only. + + The second assumption holds good if `\frac{dy}{dx} = h(x, y)` is rewritten as + `\frac{dy}{dx} = \frac{1}{h(y, x)}` and the same properties of the first assumption + satisfies. After obtaining `f(x)` and `g(y)`, the coordinates are again + interchanged, to get `\eta` as `f(x)*g(y)` + + + References + ========== + - E.S. Cheb-Terrab, A.D. Roche, Symmetries and First Order + ODE Patterns, pp. 7 - pp. 8 + + """ + + xieta = [] + y = match['y'] + h = match['h'] + hinv = match['hinv'] + func = match['func'] + x = func.args[0] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + + inf = separatevars(((log(h).diff(y)).diff(x))/h**2, dict=True, symbols=[x, y]) + if inf and inf['coeff']: + fx = inf[x] + gy = simplify(fx*((1/(fx*h)).diff(x))) + gysyms = gy.free_symbols + if x not in gysyms: + gy = exp(integrate(gy, y)) + inf = {eta: S.Zero, xi: (fx*gy).subs(y, func)} + if not comp: + return [inf] + if comp and inf not in xieta: + xieta.append(inf) + + u1 = Dummy("u1") + inf = separatevars(((log(hinv).diff(y)).diff(x))/hinv**2, dict=True, symbols=[x, y]) + if inf and inf['coeff']: + fx = inf[x] + gy = simplify(fx*((1/(fx*hinv)).diff(x))) + gysyms = gy.free_symbols + if x not in gysyms: + gy = exp(integrate(gy, y)) + etaval = fx*gy + etaval = (etaval.subs([(x, u1), (y, x)])).subs(u1, y) + inf = {eta: etaval.subs(y, func), xi: S.Zero} + if not comp: + return [inf] + if comp and inf not in xieta: + xieta.append(inf) + + if xieta: + return xieta + +def lie_heuristic_bivariate(match, comp=False): + r""" + The third heuristic assumes the infinitesimals `\xi` and `\eta` + to be bi-variate polynomials in `x` and `y`. The assumption made here + for the logic below is that `h` is a rational function in `x` and `y` + though that may not be necessary for the infinitesimals to be + bivariate polynomials. The coefficients of the infinitesimals + are found out by substituting them in the PDE and grouping similar terms + that are polynomials and since they form a linear system, solve and check + for non trivial solutions. The degree of the assumed bivariates + are increased till a certain maximum value. + + References + ========== + - Lie Groups and Differential Equations + pp. 327 - pp. 329 + + """ + + h = match['h'] + hx = match['hx'] + hy = match['hy'] + func = match['func'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + if h.is_rational_function(): + # The maximum degree that the infinitesimals can take is + # calculated by this technique. + etax, etay, etad, xix, xiy, xid = symbols("etax etay etad xix xiy xid") + ipde = etax + (etay - xix)*h - xiy*h**2 - xid*hx - etad*hy + num, denom = cancel(ipde).as_numer_denom() + deg = Poly(num, x, y).total_degree() + deta = Function('deta')(x, y) + dxi = Function('dxi')(x, y) + ipde = (deta.diff(x) + (deta.diff(y) - dxi.diff(x))*h - (dxi.diff(y))*h**2 + - dxi*hx - deta*hy) + xieq = Symbol("xi0") + etaeq = Symbol("eta0") + + for i in range(deg + 1): + if i: + xieq += Add(*[ + Symbol("xi_" + str(power) + "_" + str(i - power))*x**power*y**(i - power) + for power in range(i + 1)]) + etaeq += Add(*[ + Symbol("eta_" + str(power) + "_" + str(i - power))*x**power*y**(i - power) + for power in range(i + 1)]) + pden, denom = (ipde.subs({dxi: xieq, deta: etaeq}).doit()).as_numer_denom() + pden = expand(pden) + + # If the individual terms are monomials, the coefficients + # are grouped + if pden.is_polynomial(x, y) and pden.is_Add: + polyy = Poly(pden, x, y).as_dict() + if polyy: + symset = xieq.free_symbols.union(etaeq.free_symbols) - {x, y} + soldict = solve(polyy.values(), *symset) + if isinstance(soldict, list): + soldict = soldict[0] + if any(soldict.values()): + xired = xieq.subs(soldict) + etared = etaeq.subs(soldict) + # Scaling is done by substituting one for the parameters + # This can be any number except zero. + dict_ = dict.fromkeys(symset, 1) + inf = {eta: etared.subs(dict_).subs(y, func), + xi: xired.subs(dict_).subs(y, func)} + return [inf] + +def lie_heuristic_chi(match, comp=False): + r""" + The aim of the fourth heuristic is to find the function `\chi(x, y)` + that satisfies the PDE `\frac{d\chi}{dx} + h\frac{d\chi}{dx} + - \frac{\partial h}{\partial y}\chi = 0`. + + This assumes `\chi` to be a bivariate polynomial in `x` and `y`. By intuition, + `h` should be a rational function in `x` and `y`. The method used here is + to substitute a general binomial for `\chi` up to a certain maximum degree + is reached. The coefficients of the polynomials, are calculated by by collecting + terms of the same order in `x` and `y`. + + After finding `\chi`, the next step is to use `\eta = \xi*h + \chi`, to + determine `\xi` and `\eta`. This can be done by dividing `\chi` by `h` + which would give `-\xi` as the quotient and `\eta` as the remainder. + + + References + ========== + - E.S Cheb-Terrab, L.G.S Duarte and L.A,C.P da Mota, Computer Algebra + Solving of First Order ODEs Using Symmetry Methods, pp. 8 + + """ + + h = match['h'] + hy = match['hy'] + func = match['func'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + if h.is_rational_function(): + schi, schix, schiy = symbols("schi, schix, schiy") + cpde = schix + h*schiy - hy*schi + num, denom = cancel(cpde).as_numer_denom() + deg = Poly(num, x, y).total_degree() + + chi = Function('chi')(x, y) + chix = chi.diff(x) + chiy = chi.diff(y) + cpde = chix + h*chiy - hy*chi + chieq = Symbol("chi") + for i in range(1, deg + 1): + chieq += Add(*[ + Symbol("chi_" + str(power) + "_" + str(i - power))*x**power*y**(i - power) + for power in range(i + 1)]) + cnum, cden = cancel(cpde.subs({chi : chieq}).doit()).as_numer_denom() + cnum = expand(cnum) + if cnum.is_polynomial(x, y) and cnum.is_Add: + cpoly = Poly(cnum, x, y).as_dict() + if cpoly: + solsyms = chieq.free_symbols - {x, y} + soldict = solve(cpoly.values(), *solsyms) + if isinstance(soldict, list): + soldict = soldict[0] + if any(soldict.values()): + chieq = chieq.subs(soldict) + dict_ = dict.fromkeys(solsyms, 1) + chieq = chieq.subs(dict_) + # After finding chi, the main aim is to find out + # eta, xi by the equation eta = xi*h + chi + # One method to set xi, would be rearranging it to + # (eta/h) - xi = (chi/h). This would mean dividing + # chi by h would give -xi as the quotient and eta + # as the remainder. Thanks to Sean Vig for suggesting + # this method. + xic, etac = div(chieq, h) + inf = {eta: etac.subs(y, func), xi: -xic.subs(y, func)} + return [inf] + +def lie_heuristic_function_sum(match, comp=False): + r""" + This heuristic uses the following two assumptions on `\xi` and `\eta` + + .. math:: \eta = 0, \xi = f(x) + g(y) + + .. math:: \eta = f(x) + g(y), \xi = 0 + + The first assumption of this heuristic holds good if + + .. math:: \frac{\partial}{\partial y}[(h\frac{\partial^{2}}{ + \partial x^{2}}(h^{-1}))^{-1}] + + is separable in `x` and `y`, + + 1. The separated factors containing `y` is `\frac{\partial g}{\partial y}`. + From this `g(y)` can be determined. + 2. The separated factors containing `x` is `f''(x)`. + 3. `h\frac{\partial^{2}}{\partial x^{2}}(h^{-1})` equals + `\frac{f''(x)}{f(x) + g(y)}`. From this `f(x)` can be determined. + + The second assumption holds good if `\frac{dy}{dx} = h(x, y)` is rewritten as + `\frac{dy}{dx} = \frac{1}{h(y, x)}` and the same properties of the first + assumption satisfies. After obtaining `f(x)` and `g(y)`, the coordinates + are again interchanged, to get `\eta` as `f(x) + g(y)`. + + For both assumptions, the constant factors are separated among `g(y)` + and `f''(x)`, such that `f''(x)` obtained from 3] is the same as that + obtained from 2]. If not possible, then this heuristic fails. + + + References + ========== + - E.S. Cheb-Terrab, A.D. Roche, Symmetries and First Order + ODE Patterns, pp. 7 - pp. 8 + + """ + + xieta = [] + h = match['h'] + func = match['func'] + hinv = match['hinv'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + for odefac in [h, hinv]: + factor = odefac*((1/odefac).diff(x, 2)) + sep = separatevars((1/factor).diff(y), dict=True, symbols=[x, y]) + if sep and sep['coeff'] and sep[x].has(x) and sep[y].has(y): + k = Dummy("k") + try: + gy = k*integrate(sep[y], y) + except NotImplementedError: + pass + else: + fdd = 1/(k*sep[x]*sep['coeff']) + fx = simplify(fdd/factor - gy) + check = simplify(fx.diff(x, 2) - fdd) + if fx: + if not check: + fx = fx.subs(k, 1) + gy = (gy/k) + else: + sol = solve(check, k) + if sol: + sol = sol[0] + fx = fx.subs(k, sol) + gy = (gy/k)*sol + else: + continue + if odefac == hinv: # Inverse ODE + fx = fx.subs(x, y) + gy = gy.subs(y, x) + etaval = factor_terms(fx + gy) + if etaval.is_Mul: + etaval = Mul(*[arg for arg in etaval.args if arg.has(x, y)]) + if odefac == hinv: # Inverse ODE + inf = {eta: etaval.subs(y, func), xi : S.Zero} + else: + inf = {xi: etaval.subs(y, func), eta : S.Zero} + if not comp: + return [inf] + else: + xieta.append(inf) + + if xieta: + return xieta + +def lie_heuristic_abaco2_similar(match, comp=False): + r""" + This heuristic uses the following two assumptions on `\xi` and `\eta` + + .. math:: \eta = g(x), \xi = f(x) + + .. math:: \eta = f(y), \xi = g(y) + + For the first assumption, + + 1. First `\frac{\frac{\partial h}{\partial y}}{\frac{\partial^{2} h}{ + \partial yy}}` is calculated. Let us say this value is A + + 2. If this is constant, then `h` is matched to the form `A(x) + B(x)e^{ + \frac{y}{C}}` then, `\frac{e^{\int \frac{A(x)}{C} \,dx}}{B(x)}` gives `f(x)` + and `A(x)*f(x)` gives `g(x)` + + 3. Otherwise `\frac{\frac{\partial A}{\partial X}}{\frac{\partial A}{ + \partial Y}} = \gamma` is calculated. If + + a] `\gamma` is a function of `x` alone + + b] `\frac{\gamma\frac{\partial h}{\partial y} - \gamma'(x) - \frac{ + \partial h}{\partial x}}{h + \gamma} = G` is a function of `x` alone. + then, `e^{\int G \,dx}` gives `f(x)` and `-\gamma*f(x)` gives `g(x)` + + The second assumption holds good if `\frac{dy}{dx} = h(x, y)` is rewritten as + `\frac{dy}{dx} = \frac{1}{h(y, x)}` and the same properties of the first assumption + satisfies. After obtaining `f(x)` and `g(x)`, the coordinates are again + interchanged, to get `\xi` as `f(x^*)` and `\eta` as `g(y^*)` + + References + ========== + - E.S. Cheb-Terrab, A.D. Roche, Symmetries and First Order + ODE Patterns, pp. 10 - pp. 12 + + """ + + h = match['h'] + hx = match['hx'] + hy = match['hy'] + func = match['func'] + hinv = match['hinv'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + factor = cancel(h.diff(y)/h.diff(y, 2)) + factorx = factor.diff(x) + factory = factor.diff(y) + if not factor.has(x) and not factor.has(y): + A = Wild('A', exclude=[y]) + B = Wild('B', exclude=[y]) + C = Wild('C', exclude=[x, y]) + match = h.match(A + B*exp(y/C)) + try: + tau = exp(-integrate(match[A]/match[C]), x)/match[B] + except NotImplementedError: + pass + else: + gx = match[A]*tau + return [{xi: tau, eta: gx}] + + else: + gamma = cancel(factorx/factory) + if not gamma.has(y): + tauint = cancel((gamma*hy - gamma.diff(x) - hx)/(h + gamma)) + if not tauint.has(y): + try: + tau = exp(integrate(tauint, x)) + except NotImplementedError: + pass + else: + gx = -tau*gamma + return [{xi: tau, eta: gx}] + + factor = cancel(hinv.diff(y)/hinv.diff(y, 2)) + factorx = factor.diff(x) + factory = factor.diff(y) + if not factor.has(x) and not factor.has(y): + A = Wild('A', exclude=[y]) + B = Wild('B', exclude=[y]) + C = Wild('C', exclude=[x, y]) + match = h.match(A + B*exp(y/C)) + try: + tau = exp(-integrate(match[A]/match[C]), x)/match[B] + except NotImplementedError: + pass + else: + gx = match[A]*tau + return [{eta: tau.subs(x, func), xi: gx.subs(x, func)}] + + else: + gamma = cancel(factorx/factory) + if not gamma.has(y): + tauint = cancel((gamma*hinv.diff(y) - gamma.diff(x) - hinv.diff(x))/( + hinv + gamma)) + if not tauint.has(y): + try: + tau = exp(integrate(tauint, x)) + except NotImplementedError: + pass + else: + gx = -tau*gamma + return [{eta: tau.subs(x, func), xi: gx.subs(x, func)}] + + +def lie_heuristic_abaco2_unique_unknown(match, comp=False): + r""" + This heuristic assumes the presence of unknown functions or known functions + with non-integer powers. + + 1. A list of all functions and non-integer powers containing x and y + 2. Loop over each element `f` in the list, find `\frac{\frac{\partial f}{\partial x}}{ + \frac{\partial f}{\partial x}} = R` + + If it is separable in `x` and `y`, let `X` be the factors containing `x`. Then + + a] Check if `\xi = X` and `\eta = -\frac{X}{R}` satisfy the PDE. If yes, then return + `\xi` and `\eta` + b] Check if `\xi = \frac{-R}{X}` and `\eta = -\frac{1}{X}` satisfy the PDE. + If yes, then return `\xi` and `\eta` + + If not, then check if + + a] :math:`\xi = -R,\eta = 1` + + b] :math:`\xi = 1, \eta = -\frac{1}{R}` + + are solutions. + + References + ========== + - E.S. Cheb-Terrab, A.D. Roche, Symmetries and First Order + ODE Patterns, pp. 10 - pp. 12 + + """ + + h = match['h'] + hx = match['hx'] + hy = match['hy'] + func = match['func'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + funclist = [] + for atom in h.atoms(Pow): + base, exp = atom.as_base_exp() + if base.has(x) and base.has(y): + if not exp.is_Integer: + funclist.append(atom) + + for function in h.atoms(AppliedUndef): + syms = function.free_symbols + if x in syms and y in syms: + funclist.append(function) + + for f in funclist: + frac = cancel(f.diff(y)/f.diff(x)) + sep = separatevars(frac, dict=True, symbols=[x, y]) + if sep and sep['coeff']: + xitry1 = sep[x] + etatry1 = -1/(sep[y]*sep['coeff']) + pde1 = etatry1.diff(y)*h - xitry1.diff(x)*h - xitry1*hx - etatry1*hy + if not simplify(pde1): + return [{xi: xitry1, eta: etatry1.subs(y, func)}] + xitry2 = 1/etatry1 + etatry2 = 1/xitry1 + pde2 = etatry2.diff(x) - (xitry2.diff(y))*h**2 - xitry2*hx - etatry2*hy + if not simplify(expand(pde2)): + return [{xi: xitry2.subs(y, func), eta: etatry2}] + + else: + etatry = -1/frac + pde = etatry.diff(x) + etatry.diff(y)*h - hx - etatry*hy + if not simplify(pde): + return [{xi: S.One, eta: etatry.subs(y, func)}] + xitry = -frac + pde = -xitry.diff(x)*h -xitry.diff(y)*h**2 - xitry*hx -hy + if not simplify(expand(pde)): + return [{xi: xitry.subs(y, func), eta: S.One}] + + +def lie_heuristic_abaco2_unique_general(match, comp=False): + r""" + This heuristic finds if infinitesimals of the form `\eta = f(x)`, `\xi = g(y)` + without making any assumptions on `h`. + + The complete sequence of steps is given in the paper mentioned below. + + References + ========== + - E.S. Cheb-Terrab, A.D. Roche, Symmetries and First Order + ODE Patterns, pp. 10 - pp. 12 + + """ + hx = match['hx'] + hy = match['hy'] + func = match['func'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + A = hx.diff(y) + B = hy.diff(y) + hy**2 + C = hx.diff(x) - hx**2 + + if not (A and B and C): + return + + Ax = A.diff(x) + Ay = A.diff(y) + Axy = Ax.diff(y) + Axx = Ax.diff(x) + Ayy = Ay.diff(y) + D = simplify(2*Axy + hx*Ay - Ax*hy + (hx*hy + 2*A)*A)*A - 3*Ax*Ay + if not D: + E1 = simplify(3*Ax**2 + ((hx**2 + 2*C)*A - 2*Axx)*A) + if E1: + E2 = simplify((2*Ayy + (2*B - hy**2)*A)*A - 3*Ay**2) + if not E2: + E3 = simplify( + E1*((28*Ax + 4*hx*A)*A**3 - E1*(hy*A + Ay)) - E1.diff(x)*8*A**4) + if not E3: + etaval = cancel((4*A**3*(Ax - hx*A) + E1*(hy*A - Ay))/(S(2)*A*E1)) + if x not in etaval: + try: + etaval = exp(integrate(etaval, y)) + except NotImplementedError: + pass + else: + xival = -4*A**3*etaval/E1 + if y not in xival: + return [{xi: xival, eta: etaval.subs(y, func)}] + + else: + E1 = simplify((2*Ayy + (2*B - hy**2)*A)*A - 3*Ay**2) + if E1: + E2 = simplify( + 4*A**3*D - D**2 + E1*((2*Axx - (hx**2 + 2*C)*A)*A - 3*Ax**2)) + if not E2: + E3 = simplify( + -(A*D)*E1.diff(y) + ((E1.diff(x) - hy*D)*A + 3*Ay*D + + (A*hx - 3*Ax)*E1)*E1) + if not E3: + etaval = cancel(((A*hx - Ax)*E1 - (Ay + A*hy)*D)/(S(2)*A*D)) + if x not in etaval: + try: + etaval = exp(integrate(etaval, y)) + except NotImplementedError: + pass + else: + xival = -E1*etaval/D + if y not in xival: + return [{xi: xival, eta: etaval.subs(y, func)}] + + +def lie_heuristic_linear(match, comp=False): + r""" + This heuristic assumes + + 1. `\xi = ax + by + c` and + 2. `\eta = fx + gy + h` + + After substituting the following assumptions in the determining PDE, it + reduces to + + .. math:: f + (g - a)h - bh^{2} - (ax + by + c)\frac{\partial h}{\partial x} + - (fx + gy + c)\frac{\partial h}{\partial y} + + Solving the reduced PDE obtained, using the method of characteristics, becomes + impractical. The method followed is grouping similar terms and solving the system + of linear equations obtained. The difference between the bivariate heuristic is that + `h` need not be a rational function in this case. + + References + ========== + - E.S. Cheb-Terrab, A.D. Roche, Symmetries and First Order + ODE Patterns, pp. 10 - pp. 12 + + """ + h = match['h'] + hx = match['hx'] + hy = match['hy'] + func = match['func'] + x = func.args[0] + y = match['y'] + xi = Function('xi')(x, func) + eta = Function('eta')(x, func) + + coeffdict = {} + symbols = numbered_symbols("c", cls=Dummy) + symlist = [next(symbols) for _ in islice(symbols, 6)] + C0, C1, C2, C3, C4, C5 = symlist + pde = C3 + (C4 - C0)*h - (C0*x + C1*y + C2)*hx - (C3*x + C4*y + C5)*hy - C1*h**2 + pde, denom = pde.as_numer_denom() + pde = powsimp(expand(pde)) + if pde.is_Add: + terms = pde.args + for term in terms: + if term.is_Mul: + rem = Mul(*[m for m in term.args if not m.has(x, y)]) + xypart = term/rem + if xypart not in coeffdict: + coeffdict[xypart] = rem + else: + coeffdict[xypart] += rem + else: + if term not in coeffdict: + coeffdict[term] = S.One + else: + coeffdict[term] += S.One + + sollist = coeffdict.values() + soldict = solve(sollist, symlist) + if soldict: + if isinstance(soldict, list): + soldict = soldict[0] + subval = soldict.values() + if any(t for t in subval): + onedict = dict(zip(symlist, [1]*6)) + xival = C0*x + C1*func + C2 + etaval = C3*x + C4*func + C5 + xival = xival.subs(soldict) + etaval = etaval.subs(soldict) + xival = xival.subs(onedict) + etaval = etaval.subs(onedict) + return [{xi: xival, eta: etaval}] + + +def _lie_group_remove(coords): + r""" + This function is strictly meant for internal use by the Lie group ODE solving + method. It replaces arbitrary functions returned by pdsolve as follows: + + 1] If coords is an arbitrary function, then its argument is returned. + 2] An arbitrary function in an Add object is replaced by zero. + 3] An arbitrary function in a Mul object is replaced by one. + 4] If there is no arbitrary function coords is returned unchanged. + + Examples + ======== + + >>> from sympy.solvers.ode.lie_group import _lie_group_remove + >>> from sympy import Function + >>> from sympy.abc import x, y + >>> F = Function("F") + >>> eq = x**2*y + >>> _lie_group_remove(eq) + x**2*y + >>> eq = F(x**2*y) + >>> _lie_group_remove(eq) + x**2*y + >>> eq = x*y**2 + F(x**3) + >>> _lie_group_remove(eq) + x*y**2 + >>> eq = (F(x**3) + y)*x**4 + >>> _lie_group_remove(eq) + x**4*y + + """ + if isinstance(coords, AppliedUndef): + return coords.args[0] + elif coords.is_Add: + subfunc = coords.atoms(AppliedUndef) + if subfunc: + for func in subfunc: + coords = coords.subs(func, 0) + return coords + elif coords.is_Pow: + base, expr = coords.as_base_exp() + base = _lie_group_remove(base) + expr = _lie_group_remove(expr) + return base**expr + elif coords.is_Mul: + mulargs = [] + coordargs = coords.args + for arg in coordargs: + if not isinstance(coords, AppliedUndef): + mulargs.append(_lie_group_remove(arg)) + return Mul(*mulargs) + return coords diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/nonhomogeneous.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/nonhomogeneous.py new file mode 100644 index 0000000000000000000000000000000000000000..ae39d55664e4850168ca7d68f65cf02171979957 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/nonhomogeneous.py @@ -0,0 +1,484 @@ +r""" +This File contains helper functions for nth_linear_constant_coeff_undetermined_coefficients, +nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients, +nth_linear_constant_coeff_variation_of_parameters, +and nth_linear_euler_eq_nonhomogeneous_variation_of_parameters. + +All the functions in this file are used by more than one solvers so, instead of creating +instances in other classes for using them it is better to keep it here as separate helpers. + +""" +from collections import Counter +from sympy.core import Add, S +from sympy.core.function import diff, expand, _mexpand, expand_mul +from sympy.core.relational import Eq +from sympy.core.sorting import default_sort_key +from sympy.core.symbol import Dummy, Wild +from sympy.functions import exp, cos, cosh, im, log, re, sin, sinh, \ + atan2, conjugate +from sympy.integrals import Integral +from sympy.polys import (Poly, RootOf, rootof, roots) +from sympy.simplify import collect, simplify, separatevars, powsimp, trigsimp # type: ignore +from sympy.utilities import numbered_symbols +from sympy.solvers.solvers import solve +from sympy.matrices import wronskian +from .subscheck import sub_func_doit +from sympy.solvers.ode.ode import get_numbered_constants + + +def _test_term(coeff, func, order): + r""" + Linear Euler ODEs have the form K*x**order*diff(y(x), x, order) = F(x), + where K is independent of x and y(x), order>= 0. + So we need to check that for each term, coeff == K*x**order from + some K. We have a few cases, since coeff may have several + different types. + """ + x = func.args[0] + f = func.func + if order < 0: + raise ValueError("order should be greater than 0") + if coeff == 0: + return True + if order == 0: + if x in coeff.free_symbols: + return False + return True + if coeff.is_Mul: + if coeff.has(f(x)): + return False + return x**order in coeff.args + elif coeff.is_Pow: + return coeff.as_base_exp() == (x, order) + elif order == 1: + return x == coeff + return False + + +def _get_euler_characteristic_eq_sols(eq, func, match_obj): + r""" + Returns the solution of homogeneous part of the linear euler ODE and + the list of roots of characteristic equation. + + The parameter ``match_obj`` is a dict of order:coeff terms, where order is the order + of the derivative on each term, and coeff is the coefficient of that derivative. + + """ + x = func.args[0] + f = func.func + + # First, set up characteristic equation. + chareq, symbol = S.Zero, Dummy('x') + + for i in match_obj: + if i >= 0: + chareq += (match_obj[i]*diff(x**symbol, x, i)*x**-symbol).expand() + + chareq = Poly(chareq, symbol) + chareqroots = [rootof(chareq, k) for k in range(chareq.degree())] + collectterms = [] + + # A generator of constants + constants = list(get_numbered_constants(eq, num=chareq.degree()*2)) + constants.reverse() + + # Create a dict root: multiplicity or charroots + charroots = Counter(chareqroots) + gsol = S.Zero + ln = log + for root, multiplicity in charroots.items(): + for i in range(multiplicity): + if isinstance(root, RootOf): + gsol += (x**root) * constants.pop() + if multiplicity != 1: + raise ValueError("Value should be 1") + collectterms = [(0, root, 0)] + collectterms + elif root.is_real: + gsol += ln(x)**i*(x**root) * constants.pop() + collectterms = [(i, root, 0)] + collectterms + else: + reroot = re(root) + imroot = im(root) + gsol += ln(x)**i * (x**reroot) * ( + constants.pop() * sin(abs(imroot)*ln(x)) + + constants.pop() * cos(imroot*ln(x))) + collectterms = [(i, reroot, imroot)] + collectterms + + gsol = Eq(f(x), gsol) + + gensols = [] + # Keep track of when to use sin or cos for nonzero imroot + for i, reroot, imroot in collectterms: + if imroot == 0: + gensols.append(ln(x)**i*x**reroot) + else: + sin_form = ln(x)**i*x**reroot*sin(abs(imroot)*ln(x)) + if sin_form in gensols: + cos_form = ln(x)**i*x**reroot*cos(imroot*ln(x)) + gensols.append(cos_form) + else: + gensols.append(sin_form) + return gsol, gensols + + +def _solve_variation_of_parameters(eq, func, roots, homogen_sol, order, match_obj, simplify_flag=True): + r""" + Helper function for the method of variation of parameters and nonhomogeneous euler eq. + + See the + :py:meth:`~sympy.solvers.ode.single.NthLinearConstantCoeffVariationOfParameters` + docstring for more information on this method. + + The parameter are ``match_obj`` should be a dictionary that has the following + keys: + + ``list`` + A list of solutions to the homogeneous equation. + + ``sol`` + The general solution. + + """ + f = func.func + x = func.args[0] + r = match_obj + psol = 0 + wr = wronskian(roots, x) + + if simplify_flag: + wr = simplify(wr) # We need much better simplification for + # some ODEs. See issue 4662, for example. + # To reduce commonly occurring sin(x)**2 + cos(x)**2 to 1 + wr = trigsimp(wr, deep=True, recursive=True) + if not wr: + # The wronskian will be 0 iff the solutions are not linearly + # independent. + raise NotImplementedError("Cannot find " + str(order) + + " solutions to the homogeneous equation necessary to apply " + + "variation of parameters to " + str(eq) + " (Wronskian == 0)") + if len(roots) != order: + raise NotImplementedError("Cannot find " + str(order) + + " solutions to the homogeneous equation necessary to apply " + + "variation of parameters to " + + str(eq) + " (number of terms != order)") + negoneterm = S.NegativeOne**(order) + for i in roots: + psol += negoneterm*Integral(wronskian([sol for sol in roots if sol != i], x)*r[-1]/wr, x)*i/r[order] + negoneterm *= -1 + + if simplify_flag: + psol = simplify(psol) + psol = trigsimp(psol, deep=True) + return Eq(f(x), homogen_sol.rhs + psol) + + +def _get_const_characteristic_eq_sols(r, func, order): + r""" + Returns the roots of characteristic equation of constant coefficient + linear ODE and list of collectterms which is later on used by simplification + to use collect on solution. + + The parameter `r` is a dict of order:coeff terms, where order is the order of the + derivative on each term, and coeff is the coefficient of that derivative. + + """ + x = func.args[0] + # First, set up characteristic equation. + chareq, symbol = S.Zero, Dummy('x') + + for i in r.keys(): + if isinstance(i, str) or i < 0: + pass + else: + chareq += r[i]*symbol**i + + chareq = Poly(chareq, symbol) + # Can't just call roots because it doesn't return rootof for unsolveable + # polynomials. + chareqroots = roots(chareq, multiple=True) + if len(chareqroots) != order: + chareqroots = [rootof(chareq, k) for k in range(chareq.degree())] + + chareq_is_complex = not all(i.is_real for i in chareq.all_coeffs()) + + # Create a dict root: multiplicity or charroots + charroots = Counter(chareqroots) + # We need to keep track of terms so we can run collect() at the end. + # This is necessary for constantsimp to work properly. + collectterms = [] + gensols = [] + conjugate_roots = [] # used to prevent double-use of conjugate roots + # Loop over roots in theorder provided by roots/rootof... + for root in chareqroots: + # but don't repoeat multiple roots. + if root not in charroots: + continue + multiplicity = charroots.pop(root) + for i in range(multiplicity): + if chareq_is_complex: + gensols.append(x**i*exp(root*x)) + collectterms = [(i, root, 0)] + collectterms + continue + reroot = re(root) + imroot = im(root) + if imroot.has(atan2) and reroot.has(atan2): + # Remove this condition when re and im stop returning + # circular atan2 usages. + gensols.append(x**i*exp(root*x)) + collectterms = [(i, root, 0)] + collectterms + else: + if root in conjugate_roots: + collectterms = [(i, reroot, imroot)] + collectterms + continue + if imroot == 0: + gensols.append(x**i*exp(reroot*x)) + collectterms = [(i, reroot, 0)] + collectterms + continue + conjugate_roots.append(conjugate(root)) + gensols.append(x**i*exp(reroot*x) * sin(abs(imroot) * x)) + gensols.append(x**i*exp(reroot*x) * cos( imroot * x)) + + # This ordering is important + collectterms = [(i, reroot, imroot)] + collectterms + return gensols, collectterms + + +# Ideally these kind of simplification functions shouldn't be part of solvers. +# odesimp should be improved to handle these kind of specific simplifications. +def _get_simplified_sol(sol, func, collectterms): + r""" + Helper function which collects the solution on + collectterms. Ideally this should be handled by odesimp.It is used + only when the simplify is set to True in dsolve. + + The parameter ``collectterms`` is a list of tuple (i, reroot, imroot) where `i` is + the multiplicity of the root, reroot is real part and imroot being the imaginary part. + + """ + f = func.func + x = func.args[0] + collectterms.sort(key=default_sort_key) + collectterms.reverse() + assert len(sol) == 1 and sol[0].lhs == f(x) + sol = sol[0].rhs + sol = expand_mul(sol) + for i, reroot, imroot in collectterms: + sol = collect(sol, x**i*exp(reroot*x)*sin(abs(imroot)*x)) + sol = collect(sol, x**i*exp(reroot*x)*cos(imroot*x)) + for i, reroot, imroot in collectterms: + sol = collect(sol, x**i*exp(reroot*x)) + sol = powsimp(sol) + return Eq(f(x), sol) + + +def _undetermined_coefficients_match(expr, x, func=None, eq_homogeneous=S.Zero): + r""" + Returns a trial function match if undetermined coefficients can be applied + to ``expr``, and ``None`` otherwise. + + A trial expression can be found for an expression for use with the method + of undetermined coefficients if the expression is an + additive/multiplicative combination of constants, polynomials in `x` (the + independent variable of expr), `\sin(a x + b)`, `\cos(a x + b)`, and + `e^{a x}` terms (in other words, it has a finite number of linearly + independent derivatives). + + Note that you may still need to multiply each term returned here by + sufficient `x` to make it linearly independent with the solutions to the + homogeneous equation. + + This is intended for internal use by ``undetermined_coefficients`` hints. + + SymPy currently has no way to convert `\sin^n(x) \cos^m(y)` into a sum of + only `\sin(a x)` and `\cos(b x)` terms, so these are not implemented. So, + for example, you will need to manually convert `\sin^2(x)` into `[1 + + \cos(2 x)]/2` to properly apply the method of undetermined coefficients on + it. + + Examples + ======== + + >>> from sympy import log, exp + >>> from sympy.solvers.ode.nonhomogeneous import _undetermined_coefficients_match + >>> from sympy.abc import x + >>> _undetermined_coefficients_match(9*x*exp(x) + exp(-x), x) + {'test': True, 'trialset': {x*exp(x), exp(-x), exp(x)}} + >>> _undetermined_coefficients_match(log(x), x) + {'test': False} + + """ + a = Wild('a', exclude=[x]) + b = Wild('b', exclude=[x]) + expr = powsimp(expr, combine='exp') # exp(x)*exp(2*x + 1) => exp(3*x + 1) + retdict = {} + + def _test_term(expr, x) -> bool: + r""" + Test if ``expr`` fits the proper form for undetermined coefficients. + """ + if not expr.has(x): + return True + if expr.is_Add: + return all(_test_term(i, x) for i in expr.args) + if expr.is_Mul: + if expr.has(sin, cos): + foundtrig = False + # Make sure that there is only one trig function in the args. + # See the docstring. + for i in expr.args: + if i.has(sin, cos): + if foundtrig: + return False + else: + foundtrig = True + return all(_test_term(i, x) for i in expr.args) + if expr.is_Function: + return expr.func in (sin, cos, exp, sinh, cosh) and \ + bool(expr.args[0].match(a*x + b)) + if expr.is_Pow and expr.base.is_Symbol and expr.exp.is_Integer and \ + expr.exp >= 0: + return True + if expr.is_Pow and expr.base.is_number: + return bool(expr.exp.match(a*x + b)) + return expr.is_Symbol or bool(expr.is_number) + + def _get_trial_set(expr, x, exprs=set()): + r""" + Returns a set of trial terms for undetermined coefficients. + + The idea behind undetermined coefficients is that the terms expression + repeat themselves after a finite number of derivatives, except for the + coefficients (they are linearly dependent). So if we collect these, + we should have the terms of our trial function. + """ + def _remove_coefficient(expr, x): + r""" + Returns the expression without a coefficient. + + Similar to expr.as_independent(x)[1], except it only works + multiplicatively. + """ + term = S.One + if expr.is_Mul: + for i in expr.args: + if i.has(x): + term *= i + elif expr.has(x): + term = expr + return term + + expr = expand_mul(expr) + if expr.is_Add: + for term in expr.args: + if _remove_coefficient(term, x) in exprs: + pass + else: + exprs.add(_remove_coefficient(term, x)) + exprs = exprs.union(_get_trial_set(term, x, exprs)) + else: + term = _remove_coefficient(expr, x) + tmpset = exprs.union({term}) + oldset = set() + while tmpset != oldset: + # If you get stuck in this loop, then _test_term is probably + # broken + oldset = tmpset.copy() + expr = expr.diff(x) + term = _remove_coefficient(expr, x) + if term.is_Add: + tmpset = tmpset.union(_get_trial_set(term, x, tmpset)) + else: + tmpset.add(term) + exprs = tmpset + return exprs + + def is_homogeneous_solution(term): + r""" This function checks whether the given trialset contains any root + of homogeneous equation""" + return expand(sub_func_doit(eq_homogeneous, func, term)).is_zero + + retdict['test'] = _test_term(expr, x) + if retdict['test']: + # Try to generate a list of trial solutions that will have the + # undetermined coefficients. Note that if any of these are not linearly + # independent with any of the solutions to the homogeneous equation, + # then they will need to be multiplied by sufficient x to make them so. + # This function DOES NOT do that (it doesn't even look at the + # homogeneous equation). + temp_set = set() + for i in Add.make_args(expr): + act = _get_trial_set(i, x) + if eq_homogeneous is not S.Zero: + while any(is_homogeneous_solution(ts) for ts in act): + act = {x*ts for ts in act} + temp_set = temp_set.union(act) + + retdict['trialset'] = temp_set + return retdict + + +def _solve_undetermined_coefficients(eq, func, order, match, trialset): + r""" + Helper function for the method of undetermined coefficients. + + See the + :py:meth:`~sympy.solvers.ode.single.NthLinearConstantCoeffUndeterminedCoefficients` + docstring for more information on this method. + + The parameter ``trialset`` is the set of trial functions as returned by + ``_undetermined_coefficients_match()['trialset']``. + + The parameter ``match`` should be a dictionary that has the following + keys: + + ``list`` + A list of solutions to the homogeneous equation. + + ``sol`` + The general solution. + + """ + r = match + coeffs = numbered_symbols('a', cls=Dummy) + coefflist = [] + gensols = r['list'] + gsol = r['sol'] + f = func.func + x = func.args[0] + + if len(gensols) != order: + raise NotImplementedError("Cannot find " + str(order) + + " solutions to the homogeneous equation necessary to apply" + + " undetermined coefficients to " + str(eq) + + " (number of terms != order)") + + trialfunc = 0 + for i in trialset: + c = next(coeffs) + coefflist.append(c) + trialfunc += c*i + + eqs = sub_func_doit(eq, f(x), trialfunc) + + coeffsdict = dict(list(zip(trialset, [0]*(len(trialset) + 1)))) + + eqs = _mexpand(eqs) + + for i in Add.make_args(eqs): + s = separatevars(i, dict=True, symbols=[x]) + if coeffsdict.get(s[x]): + coeffsdict[s[x]] += s['coeff'] + else: + coeffsdict[s[x]] = s['coeff'] + + coeffvals = solve(list(coeffsdict.values()), coefflist) + + if not coeffvals: + raise NotImplementedError( + "Could not solve `%s` using the " + "method of undetermined coefficients " + "(unable to solve for coefficients)." % eq) + + psol = trialfunc.subs(coeffvals) + + return Eq(f(x), gsol.rhs + psol) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/ode.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/ode.py new file mode 100644 index 0000000000000000000000000000000000000000..6a28b2162b38a2dd8612c14e91fd588912f6756a --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/ode.py @@ -0,0 +1,3572 @@ +r""" +This module contains :py:meth:`~sympy.solvers.ode.dsolve` and different helper +functions that it uses. + +:py:meth:`~sympy.solvers.ode.dsolve` solves ordinary differential equations. +See the docstring on the various functions for their uses. Note that partial +differential equations support is in ``pde.py``. Note that hint functions +have docstrings describing their various methods, but they are intended for +internal use. Use ``dsolve(ode, func, hint=hint)`` to solve an ODE using a +specific hint. See also the docstring on +:py:meth:`~sympy.solvers.ode.dsolve`. + +**Functions in this module** + + These are the user functions in this module: + + - :py:meth:`~sympy.solvers.ode.dsolve` - Solves ODEs. + - :py:meth:`~sympy.solvers.ode.classify_ode` - Classifies ODEs into + possible hints for :py:meth:`~sympy.solvers.ode.dsolve`. + - :py:meth:`~sympy.solvers.ode.checkodesol` - Checks if an equation is the + solution to an ODE. + - :py:meth:`~sympy.solvers.ode.homogeneous_order` - Returns the + homogeneous order of an expression. + - :py:meth:`~sympy.solvers.ode.infinitesimals` - Returns the infinitesimals + of the Lie group of point transformations of an ODE, such that it is + invariant. + - :py:meth:`~sympy.solvers.ode.checkinfsol` - Checks if the given infinitesimals + are the actual infinitesimals of a first order ODE. + + These are the non-solver helper functions that are for internal use. The + user should use the various options to + :py:meth:`~sympy.solvers.ode.dsolve` to obtain the functionality provided + by these functions: + + - :py:meth:`~sympy.solvers.ode.ode.odesimp` - Does all forms of ODE + simplification. + - :py:meth:`~sympy.solvers.ode.ode.ode_sol_simplicity` - A key function for + comparing solutions by simplicity. + - :py:meth:`~sympy.solvers.ode.constantsimp` - Simplifies arbitrary + constants. + - :py:meth:`~sympy.solvers.ode.ode.constant_renumber` - Renumber arbitrary + constants. + - :py:meth:`~sympy.solvers.ode.ode._handle_Integral` - Evaluate unevaluated + Integrals. + + See also the docstrings of these functions. + +**Currently implemented solver methods** + +The following methods are implemented for solving ordinary differential +equations. See the docstrings of the various hint functions for more +information on each (run ``help(ode)``): + + - 1st order separable differential equations. + - 1st order differential equations whose coefficients or `dx` and `dy` are + functions homogeneous of the same order. + - 1st order exact differential equations. + - 1st order linear differential equations. + - 1st order Bernoulli differential equations. + - Power series solutions for first order differential equations. + - Lie Group method of solving first order differential equations. + - 2nd order Liouville differential equations. + - Power series solutions for second order differential equations + at ordinary and regular singular points. + - `n`\th order differential equation that can be solved with algebraic + rearrangement and integration. + - `n`\th order linear homogeneous differential equation with constant + coefficients. + - `n`\th order linear inhomogeneous differential equation with constant + coefficients using the method of undetermined coefficients. + - `n`\th order linear inhomogeneous differential equation with constant + coefficients using the method of variation of parameters. + +**Philosophy behind this module** + +This module is designed to make it easy to add new ODE solving methods without +having to mess with the solving code for other methods. The idea is that +there is a :py:meth:`~sympy.solvers.ode.classify_ode` function, which takes in +an ODE and tells you what hints, if any, will solve the ODE. It does this +without attempting to solve the ODE, so it is fast. Each solving method is a +hint, and it has its own function, named ``ode_``. That function takes +in the ODE and any match expression gathered by +:py:meth:`~sympy.solvers.ode.classify_ode` and returns a solved result. If +this result has any integrals in it, the hint function will return an +unevaluated :py:class:`~sympy.integrals.integrals.Integral` class. +:py:meth:`~sympy.solvers.ode.dsolve`, which is the user wrapper function +around all of this, will then call :py:meth:`~sympy.solvers.ode.ode.odesimp` on +the result, which, among other things, will attempt to solve the equation for +the dependent variable (the function we are solving for), simplify the +arbitrary constants in the expression, and evaluate any integrals, if the hint +allows it. + +**How to add new solution methods** + +If you have an ODE that you want :py:meth:`~sympy.solvers.ode.dsolve` to be +able to solve, try to avoid adding special case code here. Instead, try +finding a general method that will solve your ODE, as well as others. This +way, the :py:mod:`~sympy.solvers.ode` module will become more robust, and +unhindered by special case hacks. WolphramAlpha and Maple's +DETools[odeadvisor] function are two resources you can use to classify a +specific ODE. It is also better for a method to work with an `n`\th order ODE +instead of only with specific orders, if possible. + +To add a new method, there are a few things that you need to do. First, you +need a hint name for your method. Try to name your hint so that it is +unambiguous with all other methods, including ones that may not be implemented +yet. If your method uses integrals, also include a ``hint_Integral`` hint. +If there is more than one way to solve ODEs with your method, include a hint +for each one, as well as a ``_best`` hint. Your ``ode__best()`` +function should choose the best using min with ``ode_sol_simplicity`` as the +key argument. See +:obj:`~sympy.solvers.ode.single.HomogeneousCoeffBest`, for example. +The function that uses your method will be called ``ode_()``, so the +hint must only use characters that are allowed in a Python function name +(alphanumeric characters and the underscore '``_``' character). Include a +function for every hint, except for ``_Integral`` hints +(:py:meth:`~sympy.solvers.ode.dsolve` takes care of those automatically). +Hint names should be all lowercase, unless a word is commonly capitalized +(such as Integral or Bernoulli). If you have a hint that you do not want to +run with ``all_Integral`` that does not have an ``_Integral`` counterpart (such +as a best hint that would defeat the purpose of ``all_Integral``), you will +need to remove it manually in the :py:meth:`~sympy.solvers.ode.dsolve` code. +See also the :py:meth:`~sympy.solvers.ode.classify_ode` docstring for +guidelines on writing a hint name. + +Determine *in general* how the solutions returned by your method compare with +other methods that can potentially solve the same ODEs. Then, put your hints +in the :py:data:`~sympy.solvers.ode.allhints` tuple in the order that they +should be called. The ordering of this tuple determines which hints are +default. Note that exceptions are ok, because it is easy for the user to +choose individual hints with :py:meth:`~sympy.solvers.ode.dsolve`. In +general, ``_Integral`` variants should go at the end of the list, and +``_best`` variants should go before the various hints they apply to. For +example, the ``undetermined_coefficients`` hint comes before the +``variation_of_parameters`` hint because, even though variation of parameters +is more general than undetermined coefficients, undetermined coefficients +generally returns cleaner results for the ODEs that it can solve than +variation of parameters does, and it does not require integration, so it is +much faster. + +Next, you need to have a match expression or a function that matches the type +of the ODE, which you should put in :py:meth:`~sympy.solvers.ode.classify_ode` +(if the match function is more than just a few lines. It should match the +ODE without solving for it as much as possible, so that +:py:meth:`~sympy.solvers.ode.classify_ode` remains fast and is not hindered by +bugs in solving code. Be sure to consider corner cases. For example, if your +solution method involves dividing by something, make sure you exclude the case +where that division will be 0. + +In most cases, the matching of the ODE will also give you the various parts +that you need to solve it. You should put that in a dictionary (``.match()`` +will do this for you), and add that as ``matching_hints['hint'] = matchdict`` +in the relevant part of :py:meth:`~sympy.solvers.ode.classify_ode`. +:py:meth:`~sympy.solvers.ode.classify_ode` will then send this to +:py:meth:`~sympy.solvers.ode.dsolve`, which will send it to your function as +the ``match`` argument. Your function should be named ``ode_(eq, func, +order, match)`. If you need to send more information, put it in the ``match`` +dictionary. For example, if you had to substitute in a dummy variable in +:py:meth:`~sympy.solvers.ode.classify_ode` to match the ODE, you will need to +pass it to your function using the `match` dict to access it. You can access +the independent variable using ``func.args[0]``, and the dependent variable +(the function you are trying to solve for) as ``func.func``. If, while trying +to solve the ODE, you find that you cannot, raise ``NotImplementedError``. +:py:meth:`~sympy.solvers.ode.dsolve` will catch this error with the ``all`` +meta-hint, rather than causing the whole routine to fail. + +Add a docstring to your function that describes the method employed. Like +with anything else in SymPy, you will need to add a doctest to the docstring, +in addition to real tests in ``test_ode.py``. Try to maintain consistency +with the other hint functions' docstrings. Add your method to the list at the +top of this docstring. Also, add your method to ``ode.rst`` in the +``docs/src`` directory, so that the Sphinx docs will pull its docstring into +the main SymPy documentation. Be sure to make the Sphinx documentation by +running ``make html`` from within the doc directory to verify that the +docstring formats correctly. + +If your solution method involves integrating, use :py:obj:`~.Integral` instead of +:py:meth:`~sympy.core.expr.Expr.integrate`. This allows the user to bypass +hard/slow integration by using the ``_Integral`` variant of your hint. In +most cases, calling :py:meth:`sympy.core.basic.Basic.doit` will integrate your +solution. If this is not the case, you will need to write special code in +:py:meth:`~sympy.solvers.ode.ode._handle_Integral`. Arbitrary constants should be +symbols named ``C1``, ``C2``, and so on. All solution methods should return +an equality instance. If you need an arbitrary number of arbitrary constants, +you can use ``constants = numbered_symbols(prefix='C', cls=Symbol, start=1)``. +If it is possible to solve for the dependent function in a general way, do so. +Otherwise, do as best as you can, but do not call solve in your +``ode_()`` function. :py:meth:`~sympy.solvers.ode.ode.odesimp` will attempt +to solve the solution for you, so you do not need to do that. Lastly, if your +ODE has a common simplification that can be applied to your solutions, you can +add a special case in :py:meth:`~sympy.solvers.ode.ode.odesimp` for it. For +example, solutions returned from the ``1st_homogeneous_coeff`` hints often +have many :obj:`~sympy.functions.elementary.exponential.log` terms, so +:py:meth:`~sympy.solvers.ode.ode.odesimp` calls +:py:meth:`~sympy.simplify.simplify.logcombine` on them (it also helps to write +the arbitrary constant as ``log(C1)`` instead of ``C1`` in this case). Also +consider common ways that you can rearrange your solution to have +:py:meth:`~sympy.solvers.ode.constantsimp` take better advantage of it. It is +better to put simplification in :py:meth:`~sympy.solvers.ode.ode.odesimp` than in +your method, because it can then be turned off with the simplify flag in +:py:meth:`~sympy.solvers.ode.dsolve`. If you have any extraneous +simplification in your function, be sure to only run it using ``if +match.get('simplify', True):``, especially if it can be slow or if it can +reduce the domain of the solution. + +Finally, as with every contribution to SymPy, your method will need to be +tested. Add a test for each method in ``test_ode.py``. Follow the +conventions there, i.e., test the solver using ``dsolve(eq, f(x), +hint=your_hint)``, and also test the solution using +:py:meth:`~sympy.solvers.ode.checkodesol` (you can put these in a separate +tests and skip/XFAIL if it runs too slow/does not work). Be sure to call your +hint specifically in :py:meth:`~sympy.solvers.ode.dsolve`, that way the test +will not be broken simply by the introduction of another matching hint. If your +method works for higher order (>1) ODEs, you will need to run ``sol = +constant_renumber(sol, 'C', 1, order)`` for each solution, where ``order`` is +the order of the ODE. This is because ``constant_renumber`` renumbers the +arbitrary constants by printing order, which is platform dependent. Try to +test every corner case of your solver, including a range of orders if it is a +`n`\th order solver, but if your solver is slow, such as if it involves hard +integration, try to keep the test run time down. + +Feel free to refactor existing hints to avoid duplicating code or creating +inconsistencies. If you can show that your method exactly duplicates an +existing method, including in the simplicity and speed of obtaining the +solutions, then you can remove the old, less general method. The existing +code is tested extensively in ``test_ode.py``, so if anything is broken, one +of those tests will surely fail. + +""" + +from sympy.core import Add, S, Mul, Pow, oo +from sympy.core.containers import Tuple +from sympy.core.expr import AtomicExpr, Expr +from sympy.core.function import (Function, Derivative, AppliedUndef, diff, + expand, expand_mul, Subs) +from sympy.core.multidimensional import vectorize +from sympy.core.numbers import nan, zoo, Number +from sympy.core.relational import Equality, Eq +from sympy.core.sorting import default_sort_key, ordered +from sympy.core.symbol import Symbol, Wild, Dummy, symbols +from sympy.core.sympify import sympify +from sympy.core.traversal import preorder_traversal + +from sympy.logic.boolalg import (BooleanAtom, BooleanTrue, + BooleanFalse) +from sympy.functions import exp, log, sqrt +from sympy.functions.combinatorial.factorials import factorial +from sympy.integrals.integrals import Integral +from sympy.polys import (Poly, terms_gcd, PolynomialError, lcm) +from sympy.polys.polytools import cancel +from sympy.series import Order +from sympy.series.series import series +from sympy.simplify import (collect, logcombine, powsimp, # type: ignore + separatevars, simplify, cse) +from sympy.simplify.radsimp import collect_const +from sympy.solvers import checksol, solve + +from sympy.utilities import numbered_symbols +from sympy.utilities.iterables import uniq, sift, iterable +from sympy.solvers.deutils import _preprocess, ode_order, _desolve + + +#: This is a list of hints in the order that they should be preferred by +#: :py:meth:`~sympy.solvers.ode.classify_ode`. In general, hints earlier in the +#: list should produce simpler solutions than those later in the list (for +#: ODEs that fit both). For now, the order of this list is based on empirical +#: observations by the developers of SymPy. +#: +#: The hint used by :py:meth:`~sympy.solvers.ode.dsolve` for a specific ODE +#: can be overridden (see the docstring). +#: +#: In general, ``_Integral`` hints are grouped at the end of the list, unless +#: there is a method that returns an unevaluable integral most of the time +#: (which go near the end of the list anyway). ``default``, ``all``, +#: ``best``, and ``all_Integral`` meta-hints should not be included in this +#: list, but ``_best`` and ``_Integral`` hints should be included. +allhints = ( + "factorable", + "nth_algebraic", + "separable", + "1st_exact", + "1st_linear", + "Bernoulli", + "1st_rational_riccati", + "Riccati_special_minus2", + "1st_homogeneous_coeff_best", + "1st_homogeneous_coeff_subs_indep_div_dep", + "1st_homogeneous_coeff_subs_dep_div_indep", + "almost_linear", + "linear_coefficients", + "separable_reduced", + "1st_power_series", + "lie_group", + "nth_linear_constant_coeff_homogeneous", + "nth_linear_euler_eq_homogeneous", + "nth_linear_constant_coeff_undetermined_coefficients", + "nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients", + "nth_linear_constant_coeff_variation_of_parameters", + "nth_linear_euler_eq_nonhomogeneous_variation_of_parameters", + "Liouville", + "2nd_linear_airy", + "2nd_linear_bessel", + "2nd_hypergeometric", + "2nd_hypergeometric_Integral", + "nth_order_reducible", + "2nd_power_series_ordinary", + "2nd_power_series_regular", + "nth_algebraic_Integral", + "separable_Integral", + "1st_exact_Integral", + "1st_linear_Integral", + "Bernoulli_Integral", + "1st_homogeneous_coeff_subs_indep_div_dep_Integral", + "1st_homogeneous_coeff_subs_dep_div_indep_Integral", + "almost_linear_Integral", + "linear_coefficients_Integral", + "separable_reduced_Integral", + "nth_linear_constant_coeff_variation_of_parameters_Integral", + "nth_linear_euler_eq_nonhomogeneous_variation_of_parameters_Integral", + "Liouville_Integral", + "2nd_nonlinear_autonomous_conserved", + "2nd_nonlinear_autonomous_conserved_Integral", + ) + + + +def get_numbered_constants(eq, num=1, start=1, prefix='C'): + """ + Returns a list of constants that do not occur + in eq already. + """ + + ncs = iter_numbered_constants(eq, start, prefix) + Cs = [next(ncs) for i in range(num)] + return (Cs[0] if num == 1 else tuple(Cs)) + + +def iter_numbered_constants(eq, start=1, prefix='C'): + """ + Returns an iterator of constants that do not occur + in eq already. + """ + + if isinstance(eq, (Expr, Eq)): + eq = [eq] + elif not iterable(eq): + raise ValueError("Expected Expr or iterable but got %s" % eq) + + atom_set = set().union(*[i.free_symbols for i in eq]) + func_set = set().union(*[i.atoms(Function) for i in eq]) + if func_set: + atom_set |= {Symbol(str(f.func)) for f in func_set} + return numbered_symbols(start=start, prefix=prefix, exclude=atom_set) + + +def dsolve(eq, func=None, hint="default", simplify=True, + ics= None, xi=None, eta=None, x0=0, n=6, **kwargs): + r""" + Solves any (supported) kind of ordinary differential equation and + system of ordinary differential equations. + + For single ordinary differential equation + ========================================= + + It is classified under this when number of equation in ``eq`` is one. + **Usage** + + ``dsolve(eq, f(x), hint)`` -> Solve ordinary differential equation + ``eq`` for function ``f(x)``, using method ``hint``. + + **Details** + + ``eq`` can be any supported ordinary differential equation (see the + :py:mod:`~sympy.solvers.ode` docstring for supported methods). + This can either be an :py:class:`~sympy.core.relational.Equality`, + or an expression, which is assumed to be equal to ``0``. + + ``f(x)`` is a function of one variable whose derivatives in that + variable make up the ordinary differential equation ``eq``. In + many cases it is not necessary to provide this; it will be + autodetected (and an error raised if it could not be detected). + + ``hint`` is the solving method that you want dsolve to use. Use + ``classify_ode(eq, f(x))`` to get all of the possible hints for an + ODE. The default hint, ``default``, will use whatever hint is + returned first by :py:meth:`~sympy.solvers.ode.classify_ode`. See + Hints below for more options that you can use for hint. + + ``simplify`` enables simplification by + :py:meth:`~sympy.solvers.ode.ode.odesimp`. See its docstring for more + information. Turn this off, for example, to disable solving of + solutions for ``func`` or simplification of arbitrary constants. + It will still integrate with this hint. Note that the solution may + contain more arbitrary constants than the order of the ODE with + this option enabled. + + ``xi`` and ``eta`` are the infinitesimal functions of an ordinary + differential equation. They are the infinitesimals of the Lie group + of point transformations for which the differential equation is + invariant. The user can specify values for the infinitesimals. If + nothing is specified, ``xi`` and ``eta`` are calculated using + :py:meth:`~sympy.solvers.ode.infinitesimals` with the help of various + heuristics. + + ``ics`` is the set of initial/boundary conditions for the differential equation. + It should be given in the form of ``{f(x0): x1, f(x).diff(x).subs(x, x2): + x3}`` and so on. For power series solutions, if no initial + conditions are specified ``f(0)`` is assumed to be ``C0`` and the power + series solution is calculated about 0. + + ``x0`` is the point about which the power series solution of a differential + equation is to be evaluated. + + ``n`` gives the exponent of the dependent variable up to which the power series + solution of a differential equation is to be evaluated. + + **Hints** + + Aside from the various solving methods, there are also some meta-hints + that you can pass to :py:meth:`~sympy.solvers.ode.dsolve`: + + ``default``: + This uses whatever hint is returned first by + :py:meth:`~sympy.solvers.ode.classify_ode`. This is the + default argument to :py:meth:`~sympy.solvers.ode.dsolve`. + + ``all``: + To make :py:meth:`~sympy.solvers.ode.dsolve` apply all + relevant classification hints, use ``dsolve(ODE, func, + hint="all")``. This will return a dictionary of + ``hint:solution`` terms. If a hint causes dsolve to raise the + ``NotImplementedError``, value of that hint's key will be the + exception object raised. The dictionary will also include + some special keys: + + - ``order``: The order of the ODE. See also + :py:meth:`~sympy.solvers.deutils.ode_order` in + ``deutils.py``. + - ``best``: The simplest hint; what would be returned by + ``best`` below. + - ``best_hint``: The hint that would produce the solution + given by ``best``. If more than one hint produces the best + solution, the first one in the tuple returned by + :py:meth:`~sympy.solvers.ode.classify_ode` is chosen. + - ``default``: The solution that would be returned by default. + This is the one produced by the hint that appears first in + the tuple returned by + :py:meth:`~sympy.solvers.ode.classify_ode`. + + ``all_Integral``: + This is the same as ``all``, except if a hint also has a + corresponding ``_Integral`` hint, it only returns the + ``_Integral`` hint. This is useful if ``all`` causes + :py:meth:`~sympy.solvers.ode.dsolve` to hang because of a + difficult or impossible integral. This meta-hint will also be + much faster than ``all``, because + :py:meth:`~sympy.core.expr.Expr.integrate` is an expensive + routine. + + ``best``: + To have :py:meth:`~sympy.solvers.ode.dsolve` try all methods + and return the simplest one. This takes into account whether + the solution is solvable in the function, whether it contains + any Integral classes (i.e. unevaluatable integrals), and + which one is the shortest in size. + + See also the :py:meth:`~sympy.solvers.ode.classify_ode` docstring for + more info on hints, and the :py:mod:`~sympy.solvers.ode` docstring for + a list of all supported hints. + + **Tips** + + - You can declare the derivative of an unknown function this way: + + >>> from sympy import Function, Derivative + >>> from sympy.abc import x # x is the independent variable + >>> f = Function("f")(x) # f is a function of x + >>> # f_ will be the derivative of f with respect to x + >>> f_ = Derivative(f, x) + + - See ``test_ode.py`` for many tests, which serves also as a set of + examples for how to use :py:meth:`~sympy.solvers.ode.dsolve`. + - :py:meth:`~sympy.solvers.ode.dsolve` always returns an + :py:class:`~sympy.core.relational.Equality` class (except for the + case when the hint is ``all`` or ``all_Integral``). If possible, it + solves the solution explicitly for the function being solved for. + Otherwise, it returns an implicit solution. + - Arbitrary constants are symbols named ``C1``, ``C2``, and so on. + - Because all solutions should be mathematically equivalent, some + hints may return the exact same result for an ODE. Often, though, + two different hints will return the same solution formatted + differently. The two should be equivalent. Also note that sometimes + the values of the arbitrary constants in two different solutions may + not be the same, because one constant may have "absorbed" other + constants into it. + - Do ``help(ode.ode_)`` to get help more information on a + specific hint, where ```` is the name of a hint without + ``_Integral``. + + For system of ordinary differential equations + ============================================= + + **Usage** + ``dsolve(eq, func)`` -> Solve a system of ordinary differential + equations ``eq`` for ``func`` being list of functions including + `x(t)`, `y(t)`, `z(t)` where number of functions in the list depends + upon the number of equations provided in ``eq``. + + **Details** + + ``eq`` can be any supported system of ordinary differential equations + This can either be an :py:class:`~sympy.core.relational.Equality`, + or an expression, which is assumed to be equal to ``0``. + + ``func`` holds ``x(t)`` and ``y(t)`` being functions of one variable which + together with some of their derivatives make up the system of ordinary + differential equation ``eq``. It is not necessary to provide this; it + will be autodetected (and an error raised if it could not be detected). + + **Hints** + + The hints are formed by parameters returned by classify_sysode, combining + them give hints name used later for forming method name. + + Examples + ======== + + >>> from sympy import Function, dsolve, Eq, Derivative, sin, cos, symbols + >>> from sympy.abc import x + >>> f = Function('f') + >>> dsolve(Derivative(f(x), x, x) + 9*f(x), f(x)) + Eq(f(x), C1*sin(3*x) + C2*cos(3*x)) + + >>> eq = sin(x)*cos(f(x)) + cos(x)*sin(f(x))*f(x).diff(x) + >>> dsolve(eq, hint='1st_exact') + [Eq(f(x), -acos(C1/cos(x)) + 2*pi), Eq(f(x), acos(C1/cos(x)))] + >>> dsolve(eq, hint='almost_linear') + [Eq(f(x), -acos(C1/cos(x)) + 2*pi), Eq(f(x), acos(C1/cos(x)))] + >>> t = symbols('t') + >>> x, y = symbols('x, y', cls=Function) + >>> eq = (Eq(Derivative(x(t),t), 12*t*x(t) + 8*y(t)), Eq(Derivative(y(t),t), 21*x(t) + 7*t*y(t))) + >>> dsolve(eq) + [Eq(x(t), C1*x0(t) + C2*x0(t)*Integral(8*exp(Integral(7*t, t))*exp(Integral(12*t, t))/x0(t)**2, t)), + Eq(y(t), C1*y0(t) + C2*(y0(t)*Integral(8*exp(Integral(7*t, t))*exp(Integral(12*t, t))/x0(t)**2, t) + + exp(Integral(7*t, t))*exp(Integral(12*t, t))/x0(t)))] + >>> eq = (Eq(Derivative(x(t),t),x(t)*y(t)*sin(t)), Eq(Derivative(y(t),t),y(t)**2*sin(t))) + >>> dsolve(eq) + {Eq(x(t), -exp(C1)/(C2*exp(C1) - cos(t))), Eq(y(t), -1/(C1 - cos(t)))} + """ + if iterable(eq): + from sympy.solvers.ode.systems import dsolve_system + + # This may have to be changed in future + # when we have weakly and strongly + # connected components. This have to + # changed to show the systems that haven't + # been solved. + try: + sol = dsolve_system(eq, funcs=func, ics=ics, doit=True) + return sol[0] if len(sol) == 1 else sol + except NotImplementedError: + pass + + match = classify_sysode(eq, func) + + eq = match['eq'] + order = match['order'] + func = match['func'] + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + + # keep highest order term coefficient positive + for i in range(len(eq)): + for func_ in func: + if isinstance(func_, list): + pass + else: + if eq[i].coeff(diff(func[i],t,ode_order(eq[i], func[i]))).is_negative: + eq[i] = -eq[i] + match['eq'] = eq + if len(set(order.values()))!=1: + raise ValueError("It solves only those systems of equations whose orders are equal") + match['order'] = list(order.values())[0] + def recur_len(l): + return sum(recur_len(item) if isinstance(item,list) else 1 for item in l) + if recur_len(func) != len(eq): + raise ValueError("dsolve() and classify_sysode() work with " + "number of functions being equal to number of equations") + if match['type_of_equation'] is None: + raise NotImplementedError + else: + if match['is_linear'] == True: + solvefunc = globals()['sysode_linear_%(no_of_equation)seq_order%(order)s' % match] + else: + solvefunc = globals()['sysode_nonlinear_%(no_of_equation)seq_order%(order)s' % match] + sols = solvefunc(match) + if ics: + constants = Tuple(*sols).free_symbols - Tuple(*eq).free_symbols + solved_constants = solve_ics(sols, func, constants, ics) + return [sol.subs(solved_constants) for sol in sols] + return sols + else: + given_hint = hint # hint given by the user + + # See the docstring of _desolve for more details. + hints = _desolve(eq, func=func, + hint=hint, simplify=True, xi=xi, eta=eta, type='ode', ics=ics, + x0=x0, n=n, **kwargs) + eq = hints.pop('eq', eq) + all_ = hints.pop('all', False) + if all_: + retdict = {} + failed_hints = {} + gethints = classify_ode(eq, dict=True, hint='all') + orderedhints = gethints['ordered_hints'] + for hint in hints: + try: + rv = _helper_simplify(eq, hint, hints[hint], simplify) + except NotImplementedError as detail: + failed_hints[hint] = detail + else: + retdict[hint] = rv + func = hints[hint]['func'] + + retdict['best'] = min(list(retdict.values()), key=lambda x: + ode_sol_simplicity(x, func, trysolving=not simplify)) + if given_hint == 'best': + return retdict['best'] + for i in orderedhints: + if retdict['best'] == retdict.get(i, None): + retdict['best_hint'] = i + break + retdict['default'] = gethints['default'] + retdict['order'] = gethints['order'] + retdict.update(failed_hints) + return retdict + + else: + # The key 'hint' stores the hint needed to be solved for. + hint = hints['hint'] + return _helper_simplify(eq, hint, hints, simplify, ics=ics) + + +def _helper_simplify(eq, hint, match, simplify=True, ics=None, **kwargs): + r""" + Helper function of dsolve that calls the respective + :py:mod:`~sympy.solvers.ode` functions to solve for the ordinary + differential equations. This minimizes the computation in calling + :py:meth:`~sympy.solvers.deutils._desolve` multiple times. + """ + r = match + func = r['func'] + order = r['order'] + match = r[hint] + + if isinstance(match, SingleODESolver): + solvefunc = match + else: + solvefunc = globals()['ode_' + hint.removesuffix('_Integral')] + + free = eq.free_symbols + cons = lambda s: s.free_symbols.difference(free) + + if simplify: + # odesimp() will attempt to integrate, if necessary, apply constantsimp(), + # attempt to solve for func, and apply any other hint specific + # simplifications + if isinstance(solvefunc, SingleODESolver): + sols = solvefunc.get_general_solution() + else: + sols = solvefunc(eq, func, order, match) + if iterable(sols): + rv = [] + for s in sols: + simp = odesimp(eq, s, func, hint) + if iterable(simp): + rv.extend(simp) + else: + rv.append(simp) + else: + rv = odesimp(eq, sols, func, hint) + else: + # We still want to integrate (you can disable it separately with the hint) + if isinstance(solvefunc, SingleODESolver): + exprs = solvefunc.get_general_solution(simplify=False) + else: + match['simplify'] = False # Some hints can take advantage of this option + exprs = solvefunc(eq, func, order, match) + if isinstance(exprs, list): + rv = [_handle_Integral(expr, func, hint) for expr in exprs] + else: + rv = _handle_Integral(exprs, func, hint) + + if isinstance(rv, list): + assert all(isinstance(i, Eq) for i in rv), rv # if not => internal error + if simplify: + rv = _remove_redundant_solutions(eq, rv, order, func.args[0]) + if len(rv) == 1: + rv = rv[0] + if ics and 'power_series' not in hint: + if isinstance(rv, (Expr, Eq)): + solved_constants = solve_ics([rv], [r['func']], cons(rv), ics) + rv = rv.subs(solved_constants) + else: + rv1 = [] + for s in rv: + try: + solved_constants = solve_ics([s], [r['func']], cons(s), ics) + except ValueError: + continue + rv1.append(s.subs(solved_constants)) + if len(rv1) == 1: + return rv1[0] + rv = rv1 + return rv + + +def solve_ics(sols, funcs, constants, ics): + """ + Solve for the constants given initial conditions + + ``sols`` is a list of solutions. + + ``funcs`` is a list of functions. + + ``constants`` is a list of constants. + + ``ics`` is the set of initial/boundary conditions for the differential + equation. It should be given in the form of ``{f(x0): x1, + f(x).diff(x).subs(x, x2): x3}`` and so on. + + Returns a dictionary mapping constants to values. + ``solution.subs(constants)`` will replace the constants in ``solution``. + + Example + ======= + >>> # From dsolve(f(x).diff(x) - f(x), f(x)) + >>> from sympy import symbols, Eq, exp, Function + >>> from sympy.solvers.ode.ode import solve_ics + >>> f = Function('f') + >>> x, C1 = symbols('x C1') + >>> sols = [Eq(f(x), C1*exp(x))] + >>> funcs = [f(x)] + >>> constants = [C1] + >>> ics = {f(0): 2} + >>> solved_constants = solve_ics(sols, funcs, constants, ics) + >>> solved_constants + {C1: 2} + >>> sols[0].subs(solved_constants) + Eq(f(x), 2*exp(x)) + + """ + # Assume ics are of the form f(x0): value or Subs(diff(f(x), x, n), (x, + # x0)): value (currently checked by classify_ode). To solve, replace x + # with x0, f(x0) with value, then solve for constants. For f^(n)(x0), + # differentiate the solution n times, so that f^(n)(x) appears. + x = funcs[0].args[0] + diff_sols = [] + subs_sols = [] + diff_variables = set() + for funcarg, value in ics.items(): + if isinstance(funcarg, AppliedUndef): + x0 = funcarg.args[0] + matching_func = [f for f in funcs if f.func == funcarg.func][0] + S = sols + elif isinstance(funcarg, (Subs, Derivative)): + if isinstance(funcarg, Subs): + # Make sure it stays a subs. Otherwise subs below will produce + # a different looking term. + funcarg = funcarg.doit() + if isinstance(funcarg, Subs): + deriv = funcarg.expr + x0 = funcarg.point[0] + variables = funcarg.expr.variables + matching_func = deriv + elif isinstance(funcarg, Derivative): + deriv = funcarg + x0 = funcarg.variables[0] + variables = (x,)*len(funcarg.variables) + matching_func = deriv.subs(x0, x) + for sol in sols: + if sol.has(deriv.expr.func): + diff_sols.append(Eq(sol.lhs.diff(*variables), sol.rhs.diff(*variables))) + diff_variables.add(variables) + S = diff_sols + else: + raise NotImplementedError("Unrecognized initial condition") + + for sol in S: + if sol.has(matching_func): + sol2 = sol + sol2 = sol2.subs(x, x0) + sol2 = sol2.subs(funcarg, value) + # This check is necessary because of issue #15724 + if not isinstance(sol2, BooleanAtom) or not subs_sols: + subs_sols = [s for s in subs_sols if not isinstance(s, BooleanAtom)] + subs_sols.append(sol2) + + # TODO: Use solveset here + try: + solved_constants = solve(subs_sols, constants, dict=True) + except NotImplementedError: + solved_constants = [] + + # XXX: We can't differentiate between the solution not existing because of + # invalid initial conditions, and not existing because solve is not smart + # enough. If we could use solveset, this might be improvable, but for now, + # we use NotImplementedError in this case. + if not solved_constants: + raise ValueError("Couldn't solve for initial conditions") + + if solved_constants == True: + raise ValueError("Initial conditions did not produce any solutions for constants. Perhaps they are degenerate.") + + if len(solved_constants) > 1: + raise NotImplementedError("Initial conditions produced too many solutions for constants") + + return solved_constants[0] + +def classify_ode(eq, func=None, dict=False, ics=None, *, prep=True, xi=None, eta=None, n=None, **kwargs): + r""" + Returns a tuple of possible :py:meth:`~sympy.solvers.ode.dsolve` + classifications for an ODE. + + The tuple is ordered so that first item is the classification that + :py:meth:`~sympy.solvers.ode.dsolve` uses to solve the ODE by default. In + general, classifications at the near the beginning of the list will + produce better solutions faster than those near the end, thought there are + always exceptions. To make :py:meth:`~sympy.solvers.ode.dsolve` use a + different classification, use ``dsolve(ODE, func, + hint=)``. See also the + :py:meth:`~sympy.solvers.ode.dsolve` docstring for different meta-hints + you can use. + + If ``dict`` is true, :py:meth:`~sympy.solvers.ode.classify_ode` will + return a dictionary of ``hint:match`` expression terms. This is intended + for internal use by :py:meth:`~sympy.solvers.ode.dsolve`. Note that + because dictionaries are ordered arbitrarily, this will most likely not be + in the same order as the tuple. + + You can get help on different hints by executing + ``help(ode.ode_hintname)``, where ``hintname`` is the name of the hint + without ``_Integral``. + + See :py:data:`~sympy.solvers.ode.allhints` or the + :py:mod:`~sympy.solvers.ode` docstring for a list of all supported hints + that can be returned from :py:meth:`~sympy.solvers.ode.classify_ode`. + + Notes + ===== + + These are remarks on hint names. + + ``_Integral`` + + If a classification has ``_Integral`` at the end, it will return the + expression with an unevaluated :py:class:`~.Integral` + class in it. Note that a hint may do this anyway if + :py:meth:`~sympy.core.expr.Expr.integrate` cannot do the integral, + though just using an ``_Integral`` will do so much faster. Indeed, an + ``_Integral`` hint will always be faster than its corresponding hint + without ``_Integral`` because + :py:meth:`~sympy.core.expr.Expr.integrate` is an expensive routine. + If :py:meth:`~sympy.solvers.ode.dsolve` hangs, it is probably because + :py:meth:`~sympy.core.expr.Expr.integrate` is hanging on a tough or + impossible integral. Try using an ``_Integral`` hint or + ``all_Integral`` to get it return something. + + Note that some hints do not have ``_Integral`` counterparts. This is + because :py:func:`~sympy.integrals.integrals.integrate` is not used in + solving the ODE for those method. For example, `n`\th order linear + homogeneous ODEs with constant coefficients do not require integration + to solve, so there is no + ``nth_linear_homogeneous_constant_coeff_Integrate`` hint. You can + easily evaluate any unevaluated + :py:class:`~sympy.integrals.integrals.Integral`\s in an expression by + doing ``expr.doit()``. + + Ordinals + + Some hints contain an ordinal such as ``1st_linear``. This is to help + differentiate them from other hints, as well as from other methods + that may not be implemented yet. If a hint has ``nth`` in it, such as + the ``nth_linear`` hints, this means that the method used to applies + to ODEs of any order. + + ``indep`` and ``dep`` + + Some hints contain the words ``indep`` or ``dep``. These reference + the independent variable and the dependent function, respectively. For + example, if an ODE is in terms of `f(x)`, then ``indep`` will refer to + `x` and ``dep`` will refer to `f`. + + ``subs`` + + If a hints has the word ``subs`` in it, it means that the ODE is solved + by substituting the expression given after the word ``subs`` for a + single dummy variable. This is usually in terms of ``indep`` and + ``dep`` as above. The substituted expression will be written only in + characters allowed for names of Python objects, meaning operators will + be spelled out. For example, ``indep``/``dep`` will be written as + ``indep_div_dep``. + + ``coeff`` + + The word ``coeff`` in a hint refers to the coefficients of something + in the ODE, usually of the derivative terms. See the docstring for + the individual methods for more info (``help(ode)``). This is + contrast to ``coefficients``, as in ``undetermined_coefficients``, + which refers to the common name of a method. + + ``_best`` + + Methods that have more than one fundamental way to solve will have a + hint for each sub-method and a ``_best`` meta-classification. This + will evaluate all hints and return the best, using the same + considerations as the normal ``best`` meta-hint. + + + Examples + ======== + + >>> from sympy import Function, classify_ode, Eq + >>> from sympy.abc import x + >>> f = Function('f') + >>> classify_ode(Eq(f(x).diff(x), 0), f(x)) + ('nth_algebraic', + 'separable', + '1st_exact', + '1st_linear', + 'Bernoulli', + '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', + '1st_homogeneous_coeff_subs_dep_div_indep', + '1st_power_series', 'lie_group', 'nth_linear_constant_coeff_homogeneous', + 'nth_linear_euler_eq_homogeneous', + 'nth_algebraic_Integral', 'separable_Integral', '1st_exact_Integral', + '1st_linear_Integral', 'Bernoulli_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral') + >>> classify_ode(f(x).diff(x, 2) + 3*f(x).diff(x) + 2*f(x) - 4) + ('factorable', 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + 'nth_linear_constant_coeff_variation_of_parameters_Integral') + + """ + ics = sympify(ics) + + if func and len(func.args) != 1: + raise ValueError("dsolve() and classify_ode() only " + "work with functions of one variable, not %s" % func) + + if isinstance(eq, Equality): + eq = eq.lhs - eq.rhs + + # Some methods want the unprocessed equation + eq_orig = eq + + if prep or func is None: + eq, func_ = _preprocess(eq, func) + if func is None: + func = func_ + x = func.args[0] + f = func.func + y = Dummy('y') + terms = 5 if n is None else n + + order = ode_order(eq, f(x)) + # hint:matchdict or hint:(tuple of matchdicts) + # Also will contain "default": and "order":order items. + matching_hints = {"order": order} + + df = f(x).diff(x) + a = Wild('a', exclude=[f(x)]) + d = Wild('d', exclude=[df, f(x).diff(x, 2)]) + e = Wild('e', exclude=[df]) + n = Wild('n', exclude=[x, f(x), df]) + c1 = Wild('c1', exclude=[x]) + a3 = Wild('a3', exclude=[f(x), df, f(x).diff(x, 2)]) + b3 = Wild('b3', exclude=[f(x), df, f(x).diff(x, 2)]) + c3 = Wild('c3', exclude=[f(x), df, f(x).diff(x, 2)]) + boundary = {} # Used to extract initial conditions + C1 = Symbol("C1") + + # Preprocessing to get the initial conditions out + if ics is not None: + for funcarg in ics: + # Separating derivatives + if isinstance(funcarg, (Subs, Derivative)): + # f(x).diff(x).subs(x, 0) is a Subs, but f(x).diff(x).subs(x, + # y) is a Derivative + if isinstance(funcarg, Subs): + deriv = funcarg.expr + old = funcarg.variables[0] + new = funcarg.point[0] + elif isinstance(funcarg, Derivative): + deriv = funcarg + # No information on this. Just assume it was x + old = x + new = funcarg.variables[0] + + if (isinstance(deriv, Derivative) and isinstance(deriv.args[0], + AppliedUndef) and deriv.args[0].func == f and + len(deriv.args[0].args) == 1 and old == x and not + new.has(x) and all(i == deriv.variables[0] for i in + deriv.variables) and x not in ics[funcarg].free_symbols): + + dorder = ode_order(deriv, x) + temp = 'f' + str(dorder) + boundary.update({temp: new, temp + 'val': ics[funcarg]}) + else: + raise ValueError("Invalid boundary conditions for Derivatives") + + + # Separating functions + elif isinstance(funcarg, AppliedUndef): + if (funcarg.func == f and len(funcarg.args) == 1 and + not funcarg.args[0].has(x) and x not in ics[funcarg].free_symbols): + boundary.update({'f0': funcarg.args[0], 'f0val': ics[funcarg]}) + else: + raise ValueError("Invalid boundary conditions for Function") + + else: + raise ValueError("Enter boundary conditions of the form ics={f(point): value, f(x).diff(x, order).subs(x, point): value}") + + ode = SingleODEProblem(eq_orig, func, x, prep=prep, xi=xi, eta=eta) + user_hint = kwargs.get('hint', 'default') + # Used when dsolve is called without an explicit hint. + # We exit early to return the first valid match + early_exit = (user_hint=='default') + user_hint = user_hint.removesuffix('_Integral') + user_map = solver_map + # An explicit hint has been given to dsolve + # Skip matching code for other hints + if user_hint not in ['default', 'all', 'all_Integral', 'best'] and user_hint in solver_map: + user_map = {user_hint: solver_map[user_hint]} + + for hint in user_map: + solver = user_map[hint](ode) + if solver.matches(): + matching_hints[hint] = solver + if user_map[hint].has_integral: + matching_hints[hint + "_Integral"] = solver + if dict and early_exit: + matching_hints["default"] = hint + return matching_hints + + eq = expand(eq) + # Precondition to try remove f(x) from highest order derivative + reduced_eq = None + if eq.is_Add: + deriv_coef = eq.coeff(f(x).diff(x, order)) + if deriv_coef not in (1, 0): + r = deriv_coef.match(a*f(x)**c1) + if r and r[c1]: + den = f(x)**r[c1] + reduced_eq = Add(*[arg/den for arg in eq.args]) + if not reduced_eq: + reduced_eq = eq + + if order == 1: + + # NON-REDUCED FORM OF EQUATION matches + r = collect(eq, df, exact=True).match(d + e * df) + if r: + r['d'] = d + r['e'] = e + r['y'] = y + r[d] = r[d].subs(f(x), y) + r[e] = r[e].subs(f(x), y) + + # FIRST ORDER POWER SERIES WHICH NEEDS INITIAL CONDITIONS + # TODO: Hint first order series should match only if d/e is analytic. + # For now, only d/e and (d/e).diff(arg) is checked for existence at + # at a given point. + # This is currently done internally in ode_1st_power_series. + point = boundary.get('f0', 0) + value = boundary.get('f0val', C1) + check = cancel(r[d]/r[e]) + check1 = check.subs({x: point, y: value}) + if not check1.has(oo) and not check1.has(zoo) and \ + not check1.has(nan) and not check1.has(-oo): + check2 = (check1.diff(x)).subs({x: point, y: value}) + if not check2.has(oo) and not check2.has(zoo) and \ + not check2.has(nan) and not check2.has(-oo): + rseries = r.copy() + rseries.update({'terms': terms, 'f0': point, 'f0val': value}) + matching_hints["1st_power_series"] = rseries + + elif order == 2: + # Homogeneous second order differential equation of the form + # a3*f(x).diff(x, 2) + b3*f(x).diff(x) + c3 + # It has a definite power series solution at point x0 if, b3/a3 and c3/a3 + # are analytic at x0. + deq = a3*(f(x).diff(x, 2)) + b3*df + c3*f(x) + r = collect(reduced_eq, + [f(x).diff(x, 2), f(x).diff(x), f(x)]).match(deq) + ordinary = False + if r: + if not all(r[key].is_polynomial() for key in r): + n, d = reduced_eq.as_numer_denom() + reduced_eq = expand(n) + r = collect(reduced_eq, + [f(x).diff(x, 2), f(x).diff(x), f(x)]).match(deq) + if r and r[a3] != 0: + p = cancel(r[b3]/r[a3]) # Used below + q = cancel(r[c3]/r[a3]) # Used below + point = kwargs.get('x0', 0) + check = p.subs(x, point) + if not check.has(oo, nan, zoo, -oo): + check = q.subs(x, point) + if not check.has(oo, nan, zoo, -oo): + ordinary = True + r.update({'a3': a3, 'b3': b3, 'c3': c3, 'x0': point, 'terms': terms}) + matching_hints["2nd_power_series_ordinary"] = r + + # Checking if the differential equation has a regular singular point + # at x0. It has a regular singular point at x0, if (b3/a3)*(x - x0) + # and (c3/a3)*((x - x0)**2) are analytic at x0. + if not ordinary: + p = cancel((x - point)*p) + check = p.subs(x, point) + if not check.has(oo, nan, zoo, -oo): + q = cancel(((x - point)**2)*q) + check = q.subs(x, point) + if not check.has(oo, nan, zoo, -oo): + coeff_dict = {'p': p, 'q': q, 'x0': point, 'terms': terms} + matching_hints["2nd_power_series_regular"] = coeff_dict + + + # Order keys based on allhints. + retlist = [i for i in allhints if i in matching_hints] + if dict: + # Dictionaries are ordered arbitrarily, so make note of which + # hint would come first for dsolve(). Use an ordered dict in Py 3. + matching_hints["default"] = retlist[0] if retlist else None + matching_hints["ordered_hints"] = tuple(retlist) + return matching_hints + else: + return tuple(retlist) + + +def classify_sysode(eq, funcs=None, **kwargs): + r""" + Returns a dictionary of parameter names and values that define the system + of ordinary differential equations in ``eq``. + The parameters are further used in + :py:meth:`~sympy.solvers.ode.dsolve` for solving that system. + + Some parameter names and values are: + + 'is_linear' (boolean), which tells whether the given system is linear. + Note that "linear" here refers to the operator: terms such as ``x*diff(x,t)`` are + nonlinear, whereas terms like ``sin(t)*diff(x,t)`` are still linear operators. + + 'func' (list) contains the :py:class:`~sympy.core.function.Function`s that + appear with a derivative in the ODE, i.e. those that we are trying to solve + the ODE for. + + 'order' (dict) with the maximum derivative for each element of the 'func' + parameter. + + 'func_coeff' (dict or Matrix) with the coefficient for each triple ``(equation number, + function, order)```. The coefficients are those subexpressions that do not + appear in 'func', and hence can be considered constant for purposes of ODE + solving. The value of this parameter can also be a Matrix if the system of ODEs are + linear first order of the form X' = AX where X is the vector of dependent variables. + Here, this function returns the coefficient matrix A. + + 'eq' (list) with the equations from ``eq``, sympified and transformed into + expressions (we are solving for these expressions to be zero). + + 'no_of_equations' (int) is the number of equations (same as ``len(eq)``). + + 'type_of_equation' (string) is an internal classification of the type of + ODE. + + 'is_constant' (boolean), which tells if the system of ODEs is constant coefficient + or not. This key is temporary addition for now and is in the match dict only when + the system of ODEs is linear first order constant coefficient homogeneous. So, this + key's value is True for now if it is available else it does not exist. + + 'is_homogeneous' (boolean), which tells if the system of ODEs is homogeneous. Like the + key 'is_constant', this key is a temporary addition and it is True since this key value + is available only when the system is linear first order constant coefficient homogeneous. + + References + ========== + -https://eqworld.ipmnet.ru/en/solutions/sysode/sode-toc1.htm + -A. D. Polyanin and A. V. Manzhirov, Handbook of Mathematics for Engineers and Scientists + + Examples + ======== + + >>> from sympy import Function, Eq, symbols, diff + >>> from sympy.solvers.ode.ode import classify_sysode + >>> from sympy.abc import t + >>> f, x, y = symbols('f, x, y', cls=Function) + >>> k, l, m, n = symbols('k, l, m, n', Integer=True) + >>> x1 = diff(x(t), t) ; y1 = diff(y(t), t) + >>> x2 = diff(x(t), t, t) ; y2 = diff(y(t), t, t) + >>> eq = (Eq(x1, 12*x(t) - 6*y(t)), Eq(y1, 11*x(t) + 3*y(t))) + >>> classify_sysode(eq) + {'eq': [-12*x(t) + 6*y(t) + Derivative(x(t), t), -11*x(t) - 3*y(t) + Derivative(y(t), t)], 'func': [x(t), y(t)], + 'func_coeff': {(0, x(t), 0): -12, (0, x(t), 1): 1, (0, y(t), 0): 6, (0, y(t), 1): 0, (1, x(t), 0): -11, (1, x(t), 1): 0, (1, y(t), 0): -3, (1, y(t), 1): 1}, 'is_linear': True, 'no_of_equation': 2, 'order': {x(t): 1, y(t): 1}, 'type_of_equation': None} + >>> eq = (Eq(diff(x(t),t), 5*t*x(t) + t**2*y(t) + 2), Eq(diff(y(t),t), -t**2*x(t) + 5*t*y(t))) + >>> classify_sysode(eq) + {'eq': [-t**2*y(t) - 5*t*x(t) + Derivative(x(t), t) - 2, t**2*x(t) - 5*t*y(t) + Derivative(y(t), t)], + 'func': [x(t), y(t)], 'func_coeff': {(0, x(t), 0): -5*t, (0, x(t), 1): 1, (0, y(t), 0): -t**2, (0, y(t), 1): 0, + (1, x(t), 0): t**2, (1, x(t), 1): 0, (1, y(t), 0): -5*t, (1, y(t), 1): 1}, 'is_linear': True, 'no_of_equation': 2, + 'order': {x(t): 1, y(t): 1}, 'type_of_equation': None} + + """ + + # Sympify equations and convert iterables of equations into + # a list of equations + def _sympify(eq): + return list(map(sympify, eq if iterable(eq) else [eq])) + + eq, funcs = (_sympify(w) for w in [eq, funcs]) + for i, fi in enumerate(eq): + if isinstance(fi, Equality): + eq[i] = fi.lhs - fi.rhs + + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + matching_hints = {"no_of_equation":i+1} + matching_hints['eq'] = eq + if i==0: + raise ValueError("classify_sysode() works for systems of ODEs. " + "For scalar ODEs, classify_ode should be used") + + # find all the functions if not given + order = {} + if funcs==[None]: + funcs = _extract_funcs(eq) + + funcs = list(set(funcs)) + if len(funcs) != len(eq): + raise ValueError("Number of functions given is not equal to the number of equations %s" % funcs) + + # This logic of list of lists in funcs to + # be replaced later. + func_dict = {} + for func in funcs: + if not order.get(func, False): + max_order = 0 + for i, eqs_ in enumerate(eq): + order_ = ode_order(eqs_,func) + if max_order < order_: + max_order = order_ + eq_no = i + if eq_no in func_dict: + func_dict[eq_no] = [func_dict[eq_no], func] + else: + func_dict[eq_no] = func + order[func] = max_order + + funcs = [func_dict[i] for i in range(len(func_dict))] + matching_hints['func'] = funcs + for func in funcs: + if isinstance(func, list): + for func_elem in func: + if len(func_elem.args) != 1: + raise ValueError("dsolve() and classify_sysode() work with " + "functions of one variable only, not %s" % func) + else: + if func and len(func.args) != 1: + raise ValueError("dsolve() and classify_sysode() work with " + "functions of one variable only, not %s" % func) + + # find the order of all equation in system of odes + matching_hints["order"] = order + + # find coefficients of terms f(t), diff(f(t),t) and higher derivatives + # and similarly for other functions g(t), diff(g(t),t) in all equations. + # Here j denotes the equation number, funcs[l] denotes the function about + # which we are talking about and k denotes the order of function funcs[l] + # whose coefficient we are calculating. + def linearity_check(eqs, j, func, is_linear_): + for k in range(order[func] + 1): + func_coef[j, func, k] = collect(eqs.expand(), [diff(func, t, k)]).coeff(diff(func, t, k)) + if is_linear_ == True: + if func_coef[j, func, k] == 0: + if k == 0: + coef = eqs.as_independent(func, as_Add=True)[1] + for xr in range(1, ode_order(eqs,func) + 1): + coef -= eqs.as_independent(diff(func, t, xr), as_Add=True)[1] + if coef != 0: + is_linear_ = False + else: + if eqs.as_independent(diff(func, t, k), as_Add=True)[1]: + is_linear_ = False + else: + for func_ in funcs: + if isinstance(func_, list): + for elem_func_ in func_: + dep = func_coef[j, func, k].as_independent(elem_func_, as_Add=True)[1] + if dep != 0: + is_linear_ = False + else: + dep = func_coef[j, func, k].as_independent(func_, as_Add=True)[1] + if dep != 0: + is_linear_ = False + return is_linear_ + + func_coef = {} + is_linear = True + for j, eqs in enumerate(eq): + for func in funcs: + if isinstance(func, list): + for func_elem in func: + is_linear = linearity_check(eqs, j, func_elem, is_linear) + else: + is_linear = linearity_check(eqs, j, func, is_linear) + matching_hints['func_coeff'] = func_coef + matching_hints['is_linear'] = is_linear + + + if len(set(order.values())) == 1: + order_eq = list(matching_hints['order'].values())[0] + if matching_hints['is_linear'] == True: + if matching_hints['no_of_equation'] == 2: + if order_eq == 1: + type_of_equation = check_linear_2eq_order1(eq, funcs, func_coef) + else: + type_of_equation = None + # If the equation does not match up with any of the + # general case solvers in systems.py and the number + # of equations is greater than 2, then NotImplementedError + # should be raised. + else: + type_of_equation = None + + else: + if matching_hints['no_of_equation'] == 2: + if order_eq == 1: + type_of_equation = check_nonlinear_2eq_order1(eq, funcs, func_coef) + else: + type_of_equation = None + elif matching_hints['no_of_equation'] == 3: + if order_eq == 1: + type_of_equation = check_nonlinear_3eq_order1(eq, funcs, func_coef) + else: + type_of_equation = None + else: + type_of_equation = None + else: + type_of_equation = None + + matching_hints['type_of_equation'] = type_of_equation + + return matching_hints + + +def check_linear_2eq_order1(eq, func, func_coef): + x = func[0].func + y = func[1].func + fc = func_coef + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + r = {} + # for equations Eq(a1*diff(x(t),t), b1*x(t) + c1*y(t) + d1) + # and Eq(a2*diff(y(t),t), b2*x(t) + c2*y(t) + d2) + r['a1'] = fc[0,x(t),1] ; r['a2'] = fc[1,y(t),1] + r['b1'] = -fc[0,x(t),0]/fc[0,x(t),1] ; r['b2'] = -fc[1,x(t),0]/fc[1,y(t),1] + r['c1'] = -fc[0,y(t),0]/fc[0,x(t),1] ; r['c2'] = -fc[1,y(t),0]/fc[1,y(t),1] + forcing = [S.Zero,S.Zero] + for i in range(2): + for j in Add.make_args(eq[i]): + if not j.has(x(t), y(t)): + forcing[i] += j + if not (forcing[0].has(t) or forcing[1].has(t)): + # We can handle homogeneous case and simple constant forcings + r['d1'] = forcing[0] + r['d2'] = forcing[1] + else: + # Issue #9244: nonhomogeneous linear systems are not supported + return None + + # Conditions to check for type 6 whose equations are Eq(diff(x(t),t), f(t)*x(t) + g(t)*y(t)) and + # Eq(diff(y(t),t), a*[f(t) + a*h(t)]x(t) + a*[g(t) - h(t)]*y(t)) + p = 0 + q = 0 + p1 = cancel(r['b2']/(cancel(r['b2']/r['c2']).as_numer_denom()[0])) + p2 = cancel(r['b1']/(cancel(r['b1']/r['c1']).as_numer_denom()[0])) + for n, i in enumerate([p1, p2]): + for j in Mul.make_args(collect_const(i)): + if not j.has(t): + q = j + if q and n==0: + if ((r['b2']/j - r['b1'])/(r['c1'] - r['c2']/j)) == j: + p = 1 + elif q and n==1: + if ((r['b1']/j - r['b2'])/(r['c2'] - r['c1']/j)) == j: + p = 2 + # End of condition for type 6 + + if r['d1']!=0 or r['d2']!=0: + return None + else: + if not any(r[k].has(t) for k in 'a1 a2 b1 b2 c1 c2'.split()): + return None + else: + r['b1'] = r['b1']/r['a1'] ; r['b2'] = r['b2']/r['a2'] + r['c1'] = r['c1']/r['a1'] ; r['c2'] = r['c2']/r['a2'] + if p: + return "type6" + else: + # Equations for type 7 are Eq(diff(x(t),t), f(t)*x(t) + g(t)*y(t)) and Eq(diff(y(t),t), h(t)*x(t) + p(t)*y(t)) + return "type7" +def check_nonlinear_2eq_order1(eq, func, func_coef): + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + f = Wild('f') + g = Wild('g') + u, v = symbols('u, v', cls=Dummy) + def check_type(x, y): + r1 = eq[0].match(t*diff(x(t),t) - x(t) + f) + r2 = eq[1].match(t*diff(y(t),t) - y(t) + g) + if not (r1 and r2): + r1 = eq[0].match(diff(x(t),t) - x(t)/t + f/t) + r2 = eq[1].match(diff(y(t),t) - y(t)/t + g/t) + if not (r1 and r2): + r1 = (-eq[0]).match(t*diff(x(t),t) - x(t) + f) + r2 = (-eq[1]).match(t*diff(y(t),t) - y(t) + g) + if not (r1 and r2): + r1 = (-eq[0]).match(diff(x(t),t) - x(t)/t + f/t) + r2 = (-eq[1]).match(diff(y(t),t) - y(t)/t + g/t) + if r1 and r2 and not (r1[f].subs(diff(x(t),t),u).subs(diff(y(t),t),v).has(t) \ + or r2[g].subs(diff(x(t),t),u).subs(diff(y(t),t),v).has(t)): + return 'type5' + else: + return None + for func_ in func: + if isinstance(func_, list): + x = func[0][0].func + y = func[0][1].func + eq_type = check_type(x, y) + if not eq_type: + eq_type = check_type(y, x) + return eq_type + x = func[0].func + y = func[1].func + fc = func_coef + n = Wild('n', exclude=[x(t),y(t)]) + f1 = Wild('f1', exclude=[v,t]) + f2 = Wild('f2', exclude=[v,t]) + g1 = Wild('g1', exclude=[u,t]) + g2 = Wild('g2', exclude=[u,t]) + for i in range(2): + eqs = 0 + for terms in Add.make_args(eq[i]): + eqs += terms/fc[i,func[i],1] + eq[i] = eqs + r = eq[0].match(diff(x(t),t) - x(t)**n*f) + if r: + g = (diff(y(t),t) - eq[1])/r[f] + if r and not (g.has(x(t)) or g.subs(y(t),v).has(t) or r[f].subs(x(t),u).subs(y(t),v).has(t)): + return 'type1' + r = eq[0].match(diff(x(t),t) - exp(n*x(t))*f) + if r: + g = (diff(y(t),t) - eq[1])/r[f] + if r and not (g.has(x(t)) or g.subs(y(t),v).has(t) or r[f].subs(x(t),u).subs(y(t),v).has(t)): + return 'type2' + g = Wild('g') + r1 = eq[0].match(diff(x(t),t) - f) + r2 = eq[1].match(diff(y(t),t) - g) + if r1 and r2 and not (r1[f].subs(x(t),u).subs(y(t),v).has(t) or \ + r2[g].subs(x(t),u).subs(y(t),v).has(t)): + return 'type3' + r1 = eq[0].match(diff(x(t),t) - f) + r2 = eq[1].match(diff(y(t),t) - g) + num, den = ( + (r1[f].subs(x(t),u).subs(y(t),v))/ + (r2[g].subs(x(t),u).subs(y(t),v))).as_numer_denom() + R1 = num.match(f1*g1) + R2 = den.match(f2*g2) + # phi = (r1[f].subs(x(t),u).subs(y(t),v))/num + if R1 and R2: + return 'type4' + return None + + +def check_nonlinear_2eq_order2(eq, func, func_coef): + return None + +def check_nonlinear_3eq_order1(eq, func, func_coef): + x = func[0].func + y = func[1].func + z = func[2].func + fc = func_coef + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + u, v, w = symbols('u, v, w', cls=Dummy) + a = Wild('a', exclude=[x(t), y(t), z(t), t]) + b = Wild('b', exclude=[x(t), y(t), z(t), t]) + c = Wild('c', exclude=[x(t), y(t), z(t), t]) + f = Wild('f') + F1 = Wild('F1') + F2 = Wild('F2') + F3 = Wild('F3') + for i in range(3): + eqs = 0 + for terms in Add.make_args(eq[i]): + eqs += terms/fc[i,func[i],1] + eq[i] = eqs + r1 = eq[0].match(diff(x(t),t) - a*y(t)*z(t)) + r2 = eq[1].match(diff(y(t),t) - b*z(t)*x(t)) + r3 = eq[2].match(diff(z(t),t) - c*x(t)*y(t)) + if r1 and r2 and r3: + num1, den1 = r1[a].as_numer_denom() + num2, den2 = r2[b].as_numer_denom() + num3, den3 = r3[c].as_numer_denom() + if solve([num1*u-den1*(v-w), num2*v-den2*(w-u), num3*w-den3*(u-v)],[u, v]): + return 'type1' + r = eq[0].match(diff(x(t),t) - y(t)*z(t)*f) + if r: + r1 = collect_const(r[f]).match(a*f) + r2 = ((diff(y(t),t) - eq[1])/r1[f]).match(b*z(t)*x(t)) + r3 = ((diff(z(t),t) - eq[2])/r1[f]).match(c*x(t)*y(t)) + if r1 and r2 and r3: + num1, den1 = r1[a].as_numer_denom() + num2, den2 = r2[b].as_numer_denom() + num3, den3 = r3[c].as_numer_denom() + if solve([num1*u-den1*(v-w), num2*v-den2*(w-u), num3*w-den3*(u-v)],[u, v]): + return 'type2' + r = eq[0].match(diff(x(t),t) - (F2-F3)) + if r: + r1 = collect_const(r[F2]).match(c*F2) + r1.update(collect_const(r[F3]).match(b*F3)) + if r1: + if eq[1].has(r1[F2]) and not eq[1].has(r1[F3]): + r1[F2], r1[F3] = r1[F3], r1[F2] + r1[c], r1[b] = -r1[b], -r1[c] + r2 = eq[1].match(diff(y(t),t) - a*r1[F3] + r1[c]*F1) + if r2: + r3 = (eq[2] == diff(z(t),t) - r1[b]*r2[F1] + r2[a]*r1[F2]) + if r1 and r2 and r3: + return 'type3' + r = eq[0].match(diff(x(t),t) - z(t)*F2 + y(t)*F3) + if r: + r1 = collect_const(r[F2]).match(c*F2) + r1.update(collect_const(r[F3]).match(b*F3)) + if r1: + if eq[1].has(r1[F2]) and not eq[1].has(r1[F3]): + r1[F2], r1[F3] = r1[F3], r1[F2] + r1[c], r1[b] = -r1[b], -r1[c] + r2 = (diff(y(t),t) - eq[1]).match(a*x(t)*r1[F3] - r1[c]*z(t)*F1) + if r2: + r3 = (diff(z(t),t) - eq[2] == r1[b]*y(t)*r2[F1] - r2[a]*x(t)*r1[F2]) + if r1 and r2 and r3: + return 'type4' + r = (diff(x(t),t) - eq[0]).match(x(t)*(F2 - F3)) + if r: + r1 = collect_const(r[F2]).match(c*F2) + r1.update(collect_const(r[F3]).match(b*F3)) + if r1: + if eq[1].has(r1[F2]) and not eq[1].has(r1[F3]): + r1[F2], r1[F3] = r1[F3], r1[F2] + r1[c], r1[b] = -r1[b], -r1[c] + r2 = (diff(y(t),t) - eq[1]).match(y(t)*(a*r1[F3] - r1[c]*F1)) + if r2: + r3 = (diff(z(t),t) - eq[2] == z(t)*(r1[b]*r2[F1] - r2[a]*r1[F2])) + if r1 and r2 and r3: + return 'type5' + return None + + +def check_nonlinear_3eq_order2(eq, func, func_coef): + return None + + +@vectorize(0) +def odesimp(ode, eq, func, hint): + r""" + Simplifies solutions of ODEs, including trying to solve for ``func`` and + running :py:meth:`~sympy.solvers.ode.constantsimp`. + + It may use knowledge of the type of solution that the hint returns to + apply additional simplifications. + + It also attempts to integrate any :py:class:`~sympy.integrals.integrals.Integral`\s + in the expression, if the hint is not an ``_Integral`` hint. + + This function should have no effect on expressions returned by + :py:meth:`~sympy.solvers.ode.dsolve`, as + :py:meth:`~sympy.solvers.ode.dsolve` already calls + :py:meth:`~sympy.solvers.ode.ode.odesimp`, but the individual hint functions + do not call :py:meth:`~sympy.solvers.ode.ode.odesimp` (because the + :py:meth:`~sympy.solvers.ode.dsolve` wrapper does). Therefore, this + function is designed for mainly internal use. + + Examples + ======== + + >>> from sympy import sin, symbols, dsolve, pprint, Function + >>> from sympy.solvers.ode.ode import odesimp + >>> x, u2, C1= symbols('x,u2,C1') + >>> f = Function('f') + + >>> eq = dsolve(x*f(x).diff(x) - f(x) - x*sin(f(x)/x), f(x), + ... hint='1st_homogeneous_coeff_subs_indep_div_dep_Integral', + ... simplify=False) + >>> pprint(eq, wrap_line=False) + x + ---- + f(x) + / + | + | / 1 \ + | -|u1 + -------| + | | /1 \| + | | sin|--|| + | \ \u1// + log(f(x)) = log(C1) + | ---------------- d(u1) + | 2 + | u1 + | + / + + >>> pprint(odesimp(eq, f(x), 1, {C1}, + ... hint='1st_homogeneous_coeff_subs_indep_div_dep' + ... )) #doctest: +SKIP + x + --------- = C1 + /f(x)\ + tan|----| + \2*x / + + """ + x = func.args[0] + f = func.func + C1 = get_numbered_constants(eq, num=1) + constants = eq.free_symbols - ode.free_symbols + + # First, integrate if the hint allows it. + eq = _handle_Integral(eq, func, hint) + if hint.startswith("nth_linear_euler_eq_nonhomogeneous"): + eq = simplify(eq) + if not isinstance(eq, Equality): + raise TypeError("eq should be an instance of Equality") + + # allow simplifications under assumption that symbols are nonzero + eq = eq.xreplace((_:={i: Dummy(nonzero=True) for i in constants})).xreplace({_[i]: i for i in _}) + + # Second, clean up the arbitrary constants. + # Right now, nth linear hints can put as many as 2*order constants in an + # expression. If that number grows with another hint, the third argument + # here should be raised accordingly, or constantsimp() rewritten to handle + # an arbitrary number of constants. + eq = constantsimp(eq, constants) + + # Lastly, now that we have cleaned up the expression, try solving for func. + # When CRootOf is implemented in solve(), we will want to return a CRootOf + # every time instead of an Equality. + + # Get the f(x) on the left if possible. + if eq.rhs == func and not eq.lhs.has(func): + eq = [Eq(eq.rhs, eq.lhs)] + + # make sure we are working with lists of solutions in simplified form. + if eq.lhs == func and not eq.rhs.has(func): + # The solution is already solved + eq = [eq] + + else: + # The solution is not solved, so try to solve it + try: + floats = any(i.is_Float for i in eq.atoms(Number)) + eqsol = solve(eq, func, force=True, rational=False if floats else None) + if not eqsol: + raise NotImplementedError + except (NotImplementedError, PolynomialError): + eq = [eq] + else: + def _expand(expr): + numer, denom = expr.as_numer_denom() + + if denom.is_Add: + return expr + else: + return powsimp(expr.expand(), combine='exp', deep=True) + + # XXX: the rest of odesimp() expects each ``t`` to be in a + # specific normal form: rational expression with numerator + # expanded, but with combined exponential functions (at + # least in this setup all tests pass). + eq = [Eq(f(x), _expand(t)) for t in eqsol] + + # special simplification of the lhs. + if hint.startswith("1st_homogeneous_coeff"): + for j, eqi in enumerate(eq): + newi = logcombine(eqi, force=True) + if isinstance(newi.lhs, log) and newi.rhs == 0: + newi = Eq(newi.lhs.args[0]/C1, C1) + eq[j] = newi + + # We cleaned up the constants before solving to help the solve engine with + # a simpler expression, but the solved expression could have introduced + # things like -C1, so rerun constantsimp() one last time before returning. + for i, eqi in enumerate(eq): + eq[i] = constantsimp(eqi, constants) + eq[i] = constant_renumber(eq[i], ode.free_symbols) + + # If there is only 1 solution, return it; + # otherwise return the list of solutions. + if len(eq) == 1: + eq = eq[0] + return eq + + +def ode_sol_simplicity(sol, func, trysolving=True): + r""" + Returns an extended integer representing how simple a solution to an ODE + is. + + The following things are considered, in order from most simple to least: + + - ``sol`` is solved for ``func``. + - ``sol`` is not solved for ``func``, but can be if passed to solve (e.g., + a solution returned by ``dsolve(ode, func, simplify=False``). + - If ``sol`` is not solved for ``func``, then base the result on the + length of ``sol``, as computed by ``len(str(sol))``. + - If ``sol`` has any unevaluated :py:class:`~sympy.integrals.integrals.Integral`\s, + this will automatically be considered less simple than any of the above. + + This function returns an integer such that if solution A is simpler than + solution B by above metric, then ``ode_sol_simplicity(sola, func) < + ode_sol_simplicity(solb, func)``. + + Currently, the following are the numbers returned, but if the heuristic is + ever improved, this may change. Only the ordering is guaranteed. + + +----------------------------------------------+-------------------+ + | Simplicity | Return | + +==============================================+===================+ + | ``sol`` solved for ``func`` | ``-2`` | + +----------------------------------------------+-------------------+ + | ``sol`` not solved for ``func`` but can be | ``-1`` | + +----------------------------------------------+-------------------+ + | ``sol`` is not solved nor solvable for | ``len(str(sol))`` | + | ``func`` | | + +----------------------------------------------+-------------------+ + | ``sol`` contains an | ``oo`` | + | :obj:`~sympy.integrals.integrals.Integral` | | + +----------------------------------------------+-------------------+ + + ``oo`` here means the SymPy infinity, which should compare greater than + any integer. + + If you already know :py:meth:`~sympy.solvers.solvers.solve` cannot solve + ``sol``, you can use ``trysolving=False`` to skip that step, which is the + only potentially slow step. For example, + :py:meth:`~sympy.solvers.ode.dsolve` with the ``simplify=False`` flag + should do this. + + If ``sol`` is a list of solutions, if the worst solution in the list + returns ``oo`` it returns that, otherwise it returns ``len(str(sol))``, + that is, the length of the string representation of the whole list. + + Examples + ======== + + This function is designed to be passed to ``min`` as the key argument, + such as ``min(listofsolutions, key=lambda i: ode_sol_simplicity(i, + f(x)))``. + + >>> from sympy import symbols, Function, Eq, tan, Integral + >>> from sympy.solvers.ode.ode import ode_sol_simplicity + >>> x, C1, C2 = symbols('x, C1, C2') + >>> f = Function('f') + + >>> ode_sol_simplicity(Eq(f(x), C1*x**2), f(x)) + -2 + >>> ode_sol_simplicity(Eq(x**2 + f(x), C1), f(x)) + -1 + >>> ode_sol_simplicity(Eq(f(x), C1*Integral(2*x, x)), f(x)) + oo + >>> eq1 = Eq(f(x)/tan(f(x)/(2*x)), C1) + >>> eq2 = Eq(f(x)/tan(f(x)/(2*x) + f(x)), C2) + >>> [ode_sol_simplicity(eq, f(x)) for eq in [eq1, eq2]] + [28, 35] + >>> min([eq1, eq2], key=lambda i: ode_sol_simplicity(i, f(x))) + Eq(f(x)/tan(f(x)/(2*x)), C1) + + """ + # TODO: if two solutions are solved for f(x), we still want to be + # able to get the simpler of the two + + # See the docstring for the coercion rules. We check easier (faster) + # things here first, to save time. + + if iterable(sol): + # See if there are Integrals + for i in sol: + if ode_sol_simplicity(i, func, trysolving=trysolving) == oo: + return oo + + return len(str(sol)) + + if sol.has(Integral): + return oo + + # Next, try to solve for func. This code will change slightly when CRootOf + # is implemented in solve(). Probably a CRootOf solution should fall + # somewhere between a normal solution and an unsolvable expression. + + # First, see if they are already solved + if sol.lhs == func and not sol.rhs.has(func) or \ + sol.rhs == func and not sol.lhs.has(func): + return -2 + # We are not so lucky, try solving manually + if trysolving: + try: + sols = solve(sol, func) + if not sols: + raise NotImplementedError + except NotImplementedError: + pass + else: + return -1 + + # Finally, a naive computation based on the length of the string version + # of the expression. This may favor combined fractions because they + # will not have duplicate denominators, and may slightly favor expressions + # with fewer additions and subtractions, as those are separated by spaces + # by the printer. + + # Additional ideas for simplicity heuristics are welcome, like maybe + # checking if a equation has a larger domain, or if constantsimp has + # introduced arbitrary constants numbered higher than the order of a + # given ODE that sol is a solution of. + return len(str(sol)) + + +def _extract_funcs(eqs): + funcs = [] + for eq in eqs: + derivs = [node for node in preorder_traversal(eq) if isinstance(node, Derivative)] + func = [] + for d in derivs: + func += list(d.atoms(AppliedUndef)) + for func_ in func: + funcs.append(func_) + funcs = list(uniq(funcs)) + + return funcs + + +def _get_constant_subexpressions(expr, Cs): + Cs = set(Cs) + Ces = [] + def _recursive_walk(expr): + expr_syms = expr.free_symbols + if expr_syms and expr_syms.issubset(Cs): + Ces.append(expr) + else: + if expr.func == exp: + expr = expr.expand(mul=True) + if expr.func in (Add, Mul): + d = sift(expr.args, lambda i : i.free_symbols.issubset(Cs)) + if len(d[True]) > 1: + x = expr.func(*d[True]) + if not x.is_number: + Ces.append(x) + elif isinstance(expr, Integral): + if expr.free_symbols.issubset(Cs) and \ + all(len(x) == 3 for x in expr.limits): + Ces.append(expr) + for i in expr.args: + _recursive_walk(i) + return + _recursive_walk(expr) + return Ces + +def __remove_linear_redundancies(expr, Cs): + cnts = {i: expr.count(i) for i in Cs} + Cs = [i for i in Cs if cnts[i] > 0] + + def _linear(expr): + if isinstance(expr, Add): + xs = [i for i in Cs if expr.count(i)==cnts[i] \ + and 0 == expr.diff(i, 2)] + d = {} + for x in xs: + y = expr.diff(x) + if y not in d: + d[y]=[] + d[y].append(x) + for y in d: + if len(d[y]) > 1: + d[y].sort(key=str) + for x in d[y][1:]: + expr = expr.subs(x, 0) + return expr + + def _recursive_walk(expr): + if len(expr.args) != 0: + expr = expr.func(*[_recursive_walk(i) for i in expr.args]) + expr = _linear(expr) + return expr + + if isinstance(expr, Equality): + lhs, rhs = [_recursive_walk(i) for i in expr.args] + f = lambda i: isinstance(i, Number) or i in Cs + if isinstance(lhs, Symbol) and lhs in Cs: + rhs, lhs = lhs, rhs + if lhs.func in (Add, Symbol) and rhs.func in (Add, Symbol): + dlhs = sift([lhs] if isinstance(lhs, AtomicExpr) else lhs.args, f) + drhs = sift([rhs] if isinstance(rhs, AtomicExpr) else rhs.args, f) + for i in [True, False]: + for hs in [dlhs, drhs]: + if i not in hs: + hs[i] = [0] + # this calculation can be simplified + lhs = Add(*dlhs[False]) - Add(*drhs[False]) + rhs = Add(*drhs[True]) - Add(*dlhs[True]) + elif lhs.func in (Mul, Symbol) and rhs.func in (Mul, Symbol): + dlhs = sift([lhs] if isinstance(lhs, AtomicExpr) else lhs.args, f) + if True in dlhs: + if False not in dlhs: + dlhs[False] = [1] + lhs = Mul(*dlhs[False]) + rhs = rhs/Mul(*dlhs[True]) + return Eq(lhs, rhs) + else: + return _recursive_walk(expr) + +@vectorize(0) +def constantsimp(expr, constants): + r""" + Simplifies an expression with arbitrary constants in it. + + This function is written specifically to work with + :py:meth:`~sympy.solvers.ode.dsolve`, and is not intended for general use. + + Simplification is done by "absorbing" the arbitrary constants into other + arbitrary constants, numbers, and symbols that they are not independent + of. + + The symbols must all have the same name with numbers after it, for + example, ``C1``, ``C2``, ``C3``. The ``symbolname`` here would be + '``C``', the ``startnumber`` would be 1, and the ``endnumber`` would be 3. + If the arbitrary constants are independent of the variable ``x``, then the + independent symbol would be ``x``. There is no need to specify the + dependent function, such as ``f(x)``, because it already has the + independent symbol, ``x``, in it. + + Because terms are "absorbed" into arbitrary constants and because + constants are renumbered after simplifying, the arbitrary constants in + expr are not necessarily equal to the ones of the same name in the + returned result. + + If two or more arbitrary constants are added, multiplied, or raised to the + power of each other, they are first absorbed together into a single + arbitrary constant. Then the new constant is combined into other terms if + necessary. + + Absorption of constants is done with limited assistance: + + 1. terms of :py:class:`~sympy.core.add.Add`\s are collected to try join + constants so `e^x (C_1 \cos(x) + C_2 \cos(x))` will simplify to `e^x + C_1 \cos(x)`; + + 2. powers with exponents that are :py:class:`~sympy.core.add.Add`\s are + expanded so `e^{C_1 + x}` will be simplified to `C_1 e^x`. + + Use :py:meth:`~sympy.solvers.ode.ode.constant_renumber` to renumber constants + after simplification or else arbitrary numbers on constants may appear, + e.g. `C_1 + C_3 x`. + + In rare cases, a single constant can be "simplified" into two constants. + Every differential equation solution should have as many arbitrary + constants as the order of the differential equation. The result here will + be technically correct, but it may, for example, have `C_1` and `C_2` in + an expression, when `C_1` is actually equal to `C_2`. Use your discretion + in such situations, and also take advantage of the ability to use hints in + :py:meth:`~sympy.solvers.ode.dsolve`. + + Examples + ======== + + >>> from sympy import symbols + >>> from sympy.solvers.ode.ode import constantsimp + >>> C1, C2, C3, x, y = symbols('C1, C2, C3, x, y') + >>> constantsimp(2*C1*x, {C1, C2, C3}) + C1*x + >>> constantsimp(C1 + 2 + x, {C1, C2, C3}) + C1 + x + >>> constantsimp(C1*C2 + 2 + C2 + C3*x, {C1, C2, C3}) + C1 + C3*x + + """ + # This function works recursively. The idea is that, for Mul, + # Add, Pow, and Function, if the class has a constant in it, then + # we can simplify it, which we do by recursing down and + # simplifying up. Otherwise, we can skip that part of the + # expression. + + Cs = constants + + orig_expr = expr + + constant_subexprs = _get_constant_subexpressions(expr, Cs) + for xe in constant_subexprs: + xes = list(xe.free_symbols) + if not xes: + continue + if all(expr.count(c) == xe.count(c) for c in xes): + xes.sort(key=str) + expr = expr.subs(xe, xes[0]) + + # try to perform common sub-expression elimination of constant terms + try: + commons, rexpr = cse(expr) + commons.reverse() + rexpr = rexpr[0] + for s in commons: + cs = list(s[1].atoms(Symbol)) + if len(cs) == 1 and cs[0] in Cs and \ + cs[0] not in rexpr.atoms(Symbol) and \ + not any(cs[0] in ex for ex in commons if ex != s): + rexpr = rexpr.subs(s[0], cs[0]) + else: + rexpr = rexpr.subs(*s) + expr = rexpr + except IndexError: + pass + expr = __remove_linear_redundancies(expr, Cs) + + def _conditional_term_factoring(expr): + new_expr = terms_gcd(expr, clear=False, deep=True, expand=False) + + # we do not want to factor exponentials, so handle this separately + if new_expr.is_Mul: + infac = False + asfac = False + for m in new_expr.args: + if isinstance(m, exp): + asfac = True + elif m.is_Add: + infac = any(isinstance(fi, exp) for t in m.args + for fi in Mul.make_args(t)) + if asfac and infac: + new_expr = expr + break + return new_expr + + expr = _conditional_term_factoring(expr) + + # call recursively if more simplification is possible + if orig_expr != expr: + return constantsimp(expr, Cs) + return expr + + +def constant_renumber(expr, variables=None, newconstants=None): + r""" + Renumber arbitrary constants in ``expr`` to use the symbol names as given + in ``newconstants``. In the process, this reorders expression terms in a + standard way. + + If ``newconstants`` is not provided then the new constant names will be + ``C1``, ``C2`` etc. Otherwise ``newconstants`` should be an iterable + giving the new symbols to use for the constants in order. + + The ``variables`` argument is a list of non-constant symbols. All other + free symbols found in ``expr`` are assumed to be constants and will be + renumbered. If ``variables`` is not given then any numbered symbol + beginning with ``C`` (e.g. ``C1``) is assumed to be a constant. + + Symbols are renumbered based on ``.sort_key()``, so they should be + numbered roughly in the order that they appear in the final, printed + expression. Note that this ordering is based in part on hashes, so it can + produce different results on different machines. + + The structure of this function is very similar to that of + :py:meth:`~sympy.solvers.ode.constantsimp`. + + Examples + ======== + + >>> from sympy import symbols + >>> from sympy.solvers.ode.ode import constant_renumber + >>> x, C1, C2, C3 = symbols('x,C1:4') + >>> expr = C3 + C2*x + C1*x**2 + >>> expr + C1*x**2 + C2*x + C3 + >>> constant_renumber(expr) + C1 + C2*x + C3*x**2 + + The ``variables`` argument specifies which are constants so that the + other symbols will not be renumbered: + + >>> constant_renumber(expr, [C1, x]) + C1*x**2 + C2 + C3*x + + The ``newconstants`` argument is used to specify what symbols to use when + replacing the constants: + + >>> constant_renumber(expr, [x], newconstants=symbols('E1:4')) + E1 + E2*x + E3*x**2 + + """ + + # System of expressions + if isinstance(expr, (set, list, tuple)): + return type(expr)(constant_renumber(Tuple(*expr), + variables=variables, newconstants=newconstants)) + + # Symbols in solution but not ODE are constants + if variables is not None: + variables = set(variables) + free_symbols = expr.free_symbols + constantsymbols = list(free_symbols - variables) + # Any Cn is a constant... + else: + variables = set() + isconstant = lambda s: s.startswith('C') and s[1:].isdigit() + constantsymbols = [sym for sym in expr.free_symbols if isconstant(sym.name)] + + # Find new constants checking that they aren't already in the ODE + if newconstants is None: + iter_constants = numbered_symbols(start=1, prefix='C', exclude=variables) + else: + iter_constants = (sym for sym in newconstants if sym not in variables) + + constants_found = [] + + # make a mapping to send all constantsymbols to S.One and use + # that to make sure that term ordering is not dependent on + # the indexed value of C + C_1 = [(ci, S.One) for ci in constantsymbols] + sort_key=lambda arg: default_sort_key(arg.subs(C_1)) + + def _constant_renumber(expr): + r""" + We need to have an internal recursive function + """ + + # For system of expressions + if isinstance(expr, Tuple): + renumbered = [_constant_renumber(e) for e in expr] + return Tuple(*renumbered) + + if isinstance(expr, Equality): + return Eq( + _constant_renumber(expr.lhs), + _constant_renumber(expr.rhs)) + + if type(expr) not in (Mul, Add, Pow) and not expr.is_Function and \ + not expr.has(*constantsymbols): + # Base case, as above. Hope there aren't constants inside + # of some other class, because they won't be renumbered. + return expr + elif expr.is_Piecewise: + return expr + elif expr in constantsymbols: + if expr not in constants_found: + constants_found.append(expr) + return expr + elif expr.is_Function or expr.is_Pow: + return expr.func( + *[_constant_renumber(x) for x in expr.args]) + else: + sortedargs = list(expr.args) + sortedargs.sort(key=sort_key) + return expr.func(*[_constant_renumber(x) for x in sortedargs]) + expr = _constant_renumber(expr) + + # Don't renumber symbols present in the ODE. + constants_found = [c for c in constants_found if c not in variables] + + # Renumbering happens here + subs_dict = dict(zip(constants_found, iter_constants)) + expr = expr.subs(subs_dict, simultaneous=True) + + return expr + + +def _handle_Integral(expr, func, hint): + r""" + Converts a solution with Integrals in it into an actual solution. + + For most hints, this simply runs ``expr.doit()``. + + """ + if hint == "nth_linear_constant_coeff_homogeneous": + sol = expr + elif not hint.endswith("_Integral"): + sol = expr.doit() + else: + sol = expr + return sol + + +# XXX: Should this function maybe go somewhere else? + + +def homogeneous_order(eq, *symbols): + r""" + Returns the order `n` if `g` is homogeneous and ``None`` if it is not + homogeneous. + + Determines if a function is homogeneous and if so of what order. A + function `f(x, y, \cdots)` is homogeneous of order `n` if `f(t x, t y, + \cdots) = t^n f(x, y, \cdots)`. + + If the function is of two variables, `F(x, y)`, then `f` being homogeneous + of any order is equivalent to being able to rewrite `F(x, y)` as `G(x/y)` + or `H(y/x)`. This fact is used to solve 1st order ordinary differential + equations whose coefficients are homogeneous of the same order (see the + docstrings of + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffSubsDepDivIndep` and + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffSubsIndepDivDep`). + + Symbols can be functions, but every argument of the function must be a + symbol, and the arguments of the function that appear in the expression + must match those given in the list of symbols. If a declared function + appears with different arguments than given in the list of symbols, + ``None`` is returned. + + Examples + ======== + + >>> from sympy import Function, homogeneous_order, sqrt + >>> from sympy.abc import x, y + >>> f = Function('f') + >>> homogeneous_order(f(x), f(x)) is None + True + >>> homogeneous_order(f(x,y), f(y, x), x, y) is None + True + >>> homogeneous_order(f(x), f(x), x) + 1 + >>> homogeneous_order(x**2*f(x)/sqrt(x**2+f(x)**2), x, f(x)) + 2 + >>> homogeneous_order(x**2+f(x), x, f(x)) is None + True + + """ + + if not symbols: + raise ValueError("homogeneous_order: no symbols were given.") + symset = set(symbols) + eq = sympify(eq) + + # The following are not supported + if eq.has(Order, Derivative): + return None + + # These are all constants + if (eq.is_Number or + eq.is_NumberSymbol or + eq.is_number + ): + return S.Zero + + # Replace all functions with dummy variables + dum = numbered_symbols(prefix='d', cls=Dummy) + newsyms = set() + for i in [j for j in symset if getattr(j, 'is_Function')]: + iargs = set(i.args) + if iargs.difference(symset): + return None + else: + dummyvar = next(dum) + eq = eq.subs(i, dummyvar) + symset.remove(i) + newsyms.add(dummyvar) + symset.update(newsyms) + + if not eq.free_symbols & symset: + return None + + # assuming order of a nested function can only be equal to zero + if isinstance(eq, Function): + return None if homogeneous_order( + eq.args[0], *tuple(symset)) != 0 else S.Zero + + # make the replacement of x with x*t and see if t can be factored out + t = Dummy('t', positive=True) # It is sufficient that t > 0 + eqs = separatevars(eq.subs([(i, t*i) for i in symset]), [t], dict=True)[t] + if eqs is S.One: + return S.Zero # there was no term with only t + i, d = eqs.as_independent(t, as_Add=False) + b, e = d.as_base_exp() + if b == t: + return e + + +def ode_2nd_power_series_ordinary(eq, func, order, match): + r""" + Gives a power series solution to a second order homogeneous differential + equation with polynomial coefficients at an ordinary point. A homogeneous + differential equation is of the form + + .. math :: P(x)\frac{d^2y}{dx^2} + Q(x)\frac{dy}{dx} + R(x) y(x) = 0 + + For simplicity it is assumed that `P(x)`, `Q(x)` and `R(x)` are polynomials, + it is sufficient that `\frac{Q(x)}{P(x)}` and `\frac{R(x)}{P(x)}` exists at + `x_{0}`. A recurrence relation is obtained by substituting `y` as `\sum_{n=0}^\infty a_{n}x^{n}`, + in the differential equation, and equating the nth term. Using this relation + various terms can be generated. + + + Examples + ======== + + >>> from sympy import dsolve, Function, pprint + >>> from sympy.abc import x + >>> f = Function("f") + >>> eq = f(x).diff(x, 2) + f(x) + >>> pprint(dsolve(eq, hint='2nd_power_series_ordinary')) + / 4 2 \ / 2\ + |x x | | x | / 6\ + f(x) = C2*|-- - -- + 1| + C1*x*|1 - --| + O\x / + \24 2 / \ 6 / + + + References + ========== + - https://tutorial.math.lamar.edu/Classes/DE/SeriesSolutions.aspx + - George E. Simmons, "Differential Equations with Applications and + Historical Notes", p.p 176 - 184 + + """ + x = func.args[0] + f = func.func + C0, C1 = get_numbered_constants(eq, num=2) + n = Dummy("n", integer=True) + s = Wild("s") + k = Wild("k", exclude=[x]) + x0 = match['x0'] + terms = match['terms'] + p = match[match['a3']] + q = match[match['b3']] + r = match[match['c3']] + seriesdict = {} + recurr = Function("r") + + # Generating the recurrence relation which works this way: + # for the second order term the summation begins at n = 2. The coefficients + # p is multiplied with an*(n - 1)*(n - 2)*x**n-2 and a substitution is made such that + # the exponent of x becomes n. + # For example, if p is x, then the second degree recurrence term is + # an*(n - 1)*(n - 2)*x**n-1, substituting (n - 1) as n, it transforms to + # an+1*n*(n - 1)*x**n. + # A similar process is done with the first order and zeroth order term. + + coefflist = [(recurr(n), r), (n*recurr(n), q), (n*(n - 1)*recurr(n), p)] + for index, coeff in enumerate(coefflist): + if coeff[1]: + f2 = powsimp(expand((coeff[1]*(x - x0)**(n - index)).subs(x, x + x0))) + if f2.is_Add: + addargs = f2.args + else: + addargs = [f2] + for arg in addargs: + powm = arg.match(s*x**k) + term = coeff[0]*powm[s] + if not powm[k].is_Symbol: + term = term.subs(n, n - powm[k].as_independent(n)[0]) + startind = powm[k].subs(n, index) + # Seeing if the startterm can be reduced further. + # If it vanishes for n lesser than startind, it is + # equal to summation from n. + if startind: + for i in reversed(range(startind)): + if not term.subs(n, i): + seriesdict[term] = i + else: + seriesdict[term] = i + 1 + break + else: + seriesdict[term] = S.Zero + + # Stripping of terms so that the sum starts with the same number. + teq = S.Zero + suminit = seriesdict.values() + rkeys = seriesdict.keys() + req = Add(*rkeys) + if any(suminit): + maxval = max(suminit) + for term in seriesdict: + val = seriesdict[term] + if val != maxval: + for i in range(val, maxval): + teq += term.subs(n, val) + + finaldict = {} + if teq: + fargs = teq.atoms(AppliedUndef) + if len(fargs) == 1: + finaldict[fargs.pop()] = 0 + else: + maxf = max(fargs, key = lambda x: x.args[0]) + sol = solve(teq, maxf) + if isinstance(sol, list): + sol = sol[0] + finaldict[maxf] = sol + + # Finding the recurrence relation in terms of the largest term. + fargs = req.atoms(AppliedUndef) + maxf = max(fargs, key = lambda x: x.args[0]) + minf = min(fargs, key = lambda x: x.args[0]) + if minf.args[0].is_Symbol: + startiter = 0 + else: + startiter = -minf.args[0].as_independent(n)[0] + lhs = maxf + rhs = solve(req, maxf) + if isinstance(rhs, list): + rhs = rhs[0] + + # Checking how many values are already present + tcounter = len([t for t in finaldict.values() if t]) + + for _ in range(tcounter, terms - 3): # Assuming c0 and c1 to be arbitrary + check = rhs.subs(n, startiter) + nlhs = lhs.subs(n, startiter) + nrhs = check.subs(finaldict) + finaldict[nlhs] = nrhs + startiter += 1 + + # Post processing + series = C0 + C1*(x - x0) + for term in finaldict: + if finaldict[term]: + fact = term.args[0] + series += (finaldict[term].subs([(recurr(0), C0), (recurr(1), C1)])*( + x - x0)**fact) + series = collect(expand_mul(series), [C0, C1]) + Order(x**terms) + return Eq(f(x), series) + + +def ode_2nd_power_series_regular(eq, func, order, match): + r""" + Gives a power series solution to a second order homogeneous differential + equation with polynomial coefficients at a regular point. A second order + homogeneous differential equation is of the form + + .. math :: P(x)\frac{d^2y}{dx^2} + Q(x)\frac{dy}{dx} + R(x) y(x) = 0 + + A point is said to regular singular at `x0` if `x - x0\frac{Q(x)}{P(x)}` + and `(x - x0)^{2}\frac{R(x)}{P(x)}` are analytic at `x0`. For simplicity + `P(x)`, `Q(x)` and `R(x)` are assumed to be polynomials. The algorithm for + finding the power series solutions is: + + 1. Try expressing `(x - x0)P(x)` and `((x - x0)^{2})Q(x)` as power series + solutions about x0. Find `p0` and `q0` which are the constants of the + power series expansions. + 2. Solve the indicial equation `f(m) = m(m - 1) + m*p0 + q0`, to obtain the + roots `m1` and `m2` of the indicial equation. + 3. If `m1 - m2` is a non integer there exists two series solutions. If + `m1 = m2`, there exists only one solution. If `m1 - m2` is an integer, + then the existence of one solution is confirmed. The other solution may + or may not exist. + + The power series solution is of the form `x^{m}\sum_{n=0}^\infty a_{n}x^{n}`. The + coefficients are determined by the following recurrence relation. + `a_{n} = -\frac{\sum_{k=0}^{n-1} q_{n-k} + (m + k)p_{n-k}}{f(m + n)}`. For the case + in which `m1 - m2` is an integer, it can be seen from the recurrence relation + that for the lower root `m`, when `n` equals the difference of both the + roots, the denominator becomes zero. So if the numerator is not equal to zero, + a second series solution exists. + + + Examples + ======== + + >>> from sympy import dsolve, Function, pprint + >>> from sympy.abc import x + >>> f = Function("f") + >>> eq = x*(f(x).diff(x, 2)) + 2*(f(x).diff(x)) + x*f(x) + >>> pprint(dsolve(eq, hint='2nd_power_series_regular')) + / 6 4 2 \ + | x x x | + / 4 2 \ C1*|- --- + -- - -- + 1| + |x x | \ 720 24 2 / / 6\ + f(x) = C2*|--- - -- + 1| + ------------------------ + O\x / + \120 6 / x + + + References + ========== + - George E. Simmons, "Differential Equations with Applications and + Historical Notes", p.p 176 - 184 + + """ + x = func.args[0] + f = func.func + C0, C1 = get_numbered_constants(eq, num=2) + m = Dummy("m") # for solving the indicial equation + x0 = match['x0'] + terms = match['terms'] + p = match['p'] + q = match['q'] + + # Generating the indicial equation + indicial = [] + for term in [p, q]: + if not term.has(x): + indicial.append(term) + else: + term = series(term, x=x, n=1, x0=x0) + if isinstance(term, Order): + indicial.append(S.Zero) + else: + for arg in term.args: + if not arg.has(x): + indicial.append(arg) + break + + p0, q0 = indicial + sollist = solve(m*(m - 1) + m*p0 + q0, m) + if sollist and isinstance(sollist, list) and all( + sol.is_real for sol in sollist): + serdict1 = {} + serdict2 = {} + if len(sollist) == 1: + # Only one series solution exists in this case. + m1 = m2 = sollist.pop() + if terms-m1-1 <= 0: + return Eq(f(x), Order(terms)) + serdict1 = _frobenius(terms-m1-1, m1, p0, q0, p, q, x0, x, C0) + + else: + m1 = sollist[0] + m2 = sollist[1] + if m1 < m2: + m1, m2 = m2, m1 + # Irrespective of whether m1 - m2 is an integer or not, one + # Frobenius series solution exists. + serdict1 = _frobenius(terms-m1-1, m1, p0, q0, p, q, x0, x, C0) + if not (m1 - m2).is_integer: + # Second frobenius series solution exists. + serdict2 = _frobenius(terms-m2-1, m2, p0, q0, p, q, x0, x, C1) + else: + # Check if second frobenius series solution exists. + serdict2 = _frobenius(terms-m2-1, m2, p0, q0, p, q, x0, x, C1, check=m1) + + if serdict1: + finalseries1 = C0 + for key in serdict1: + power = int(key.name[1:]) + finalseries1 += serdict1[key]*(x - x0)**power + finalseries1 = (x - x0)**m1*finalseries1 + finalseries2 = S.Zero + if serdict2: + for key in serdict2: + power = int(key.name[1:]) + finalseries2 += serdict2[key]*(x - x0)**power + finalseries2 += C1 + finalseries2 = (x - x0)**m2*finalseries2 + return Eq(f(x), collect(finalseries1 + finalseries2, + [C0, C1]) + Order(x**terms)) + + +def _frobenius(n, m, p0, q0, p, q, x0, x, c, check=None): + r""" + Returns a dict with keys as coefficients and values as their values in terms of C0 + """ + n = int(n) + # In cases where m1 - m2 is not an integer + m2 = check + + d = Dummy("d") + numsyms = numbered_symbols("C", start=0) + numsyms = [next(numsyms) for i in range(n + 1)] + serlist = [] + for ser in [p, q]: + # Order term not present + if ser.is_polynomial(x) and Poly(ser, x).degree() <= n: + if x0: + ser = ser.subs(x, x + x0) + dict_ = Poly(ser, x).as_dict() + # Order term present + else: + tseries = series(ser, x=x0, n=n+1) + # Removing order + dict_ = Poly(list(ordered(tseries.args))[: -1], x).as_dict() + # Fill in with zeros, if coefficients are zero. + for i in range(n + 1): + if (i,) not in dict_: + dict_[(i,)] = S.Zero + serlist.append(dict_) + + pseries = serlist[0] + qseries = serlist[1] + indicial = d*(d - 1) + d*p0 + q0 + frobdict = {} + for i in range(1, n + 1): + num = c*(m*pseries[(i,)] + qseries[(i,)]) + for j in range(1, i): + sym = Symbol("C" + str(j)) + num += frobdict[sym]*((m + j)*pseries[(i - j,)] + qseries[(i - j,)]) + + # Checking for cases when m1 - m2 is an integer. If num equals zero + # then a second Frobenius series solution cannot be found. If num is not zero + # then set constant as zero and proceed. + if m2 is not None and i == m2 - m: + if num: + return False + else: + frobdict[numsyms[i]] = S.Zero + else: + frobdict[numsyms[i]] = -num/(indicial.subs(d, m+i)) + + return frobdict + +def _remove_redundant_solutions(eq, solns, order, var): + r""" + Remove redundant solutions from the set of solutions. + + This function is needed because otherwise dsolve can return + redundant solutions. As an example consider: + + eq = Eq((f(x).diff(x, 2))*f(x).diff(x), 0) + + There are two ways to find solutions to eq. The first is to solve f(x).diff(x, 2) = 0 + leading to solution f(x)=C1 + C2*x. The second is to solve the equation f(x).diff(x) = 0 + leading to the solution f(x) = C1. In this particular case we then see + that the second solution is a special case of the first and we do not + want to return it. + + This does not always happen. If we have + + eq = Eq((f(x)**2-4)*(f(x).diff(x)-4), 0) + + then we get the algebraic solution f(x) = [-2, 2] and the integral solution + f(x) = x + C1 and in this case the two solutions are not equivalent wrt + initial conditions so both should be returned. + """ + def is_special_case_of(soln1, soln2): + return _is_special_case_of(soln1, soln2, eq, order, var) + + unique_solns = [] + for soln1 in solns: + for soln2 in unique_solns.copy(): + if is_special_case_of(soln1, soln2): + break + elif is_special_case_of(soln2, soln1): + unique_solns.remove(soln2) + else: + unique_solns.append(soln1) + + return unique_solns + +def _is_special_case_of(soln1, soln2, eq, order, var): + r""" + True if soln1 is found to be a special case of soln2 wrt some value of the + constants that appear in soln2. False otherwise. + """ + # The solutions returned by dsolve may be given explicitly or implicitly. + # We will equate the sol1=(soln1.rhs - soln1.lhs), sol2=(soln2.rhs - soln2.lhs) + # of the two solutions. + # + # Since this is supposed to hold for all x it also holds for derivatives. + # For an order n ode we should be able to differentiate + # each solution n times to get n+1 equations. + # + # We then try to solve those n+1 equations for the integrations constants + # in sol2. If we can find a solution that does not depend on x then it + # means that some value of the constants in sol1 is a special case of + # sol2 corresponding to a particular choice of the integration constants. + + # In case the solution is in implicit form we subtract the sides + soln1 = soln1.rhs - soln1.lhs + soln2 = soln2.rhs - soln2.lhs + + # Work for the series solution + if soln1.has(Order) and soln2.has(Order): + if soln1.getO() == soln2.getO(): + soln1 = soln1.removeO() + soln2 = soln2.removeO() + else: + return False + elif soln1.has(Order) or soln2.has(Order): + return False + + constants1 = soln1.free_symbols.difference(eq.free_symbols) + constants2 = soln2.free_symbols.difference(eq.free_symbols) + + constants1_new = get_numbered_constants(Tuple(soln1, soln2), len(constants1)) + if len(constants1) == 1: + constants1_new = {constants1_new} + for c_old, c_new in zip(constants1, constants1_new): + soln1 = soln1.subs(c_old, c_new) + + # n equations for sol1 = sol2, sol1'=sol2', ... + lhs = soln1 + rhs = soln2 + eqns = [Eq(lhs, rhs)] + for n in range(1, order): + lhs = lhs.diff(var) + rhs = rhs.diff(var) + eq = Eq(lhs, rhs) + eqns.append(eq) + + # BooleanTrue/False awkwardly show up for trivial equations + if any(isinstance(eq, BooleanFalse) for eq in eqns): + return False + eqns = [eq for eq in eqns if not isinstance(eq, BooleanTrue)] + + try: + constant_solns = solve(eqns, constants2) + except NotImplementedError: + return False + + # Sometimes returns a dict and sometimes a list of dicts + if isinstance(constant_solns, dict): + constant_solns = [constant_solns] + + # after solving the issue 17418, maybe we don't need the following checksol code. + for constant_soln in constant_solns: + for eq in eqns: + eq=eq.rhs-eq.lhs + if checksol(eq, constant_soln) is not True: + return False + + # If any solution gives all constants as expressions that don't depend on + # x then there exists constants for soln2 that give soln1 + for constant_soln in constant_solns: + if not any(c.has(var) for c in constant_soln.values()): + return True + + return False + + +def ode_1st_power_series(eq, func, order, match): + r""" + The power series solution is a method which gives the Taylor series expansion + to the solution of a differential equation. + + For a first order differential equation `\frac{dy}{dx} = h(x, y)`, a power + series solution exists at a point `x = x_{0}` if `h(x, y)` is analytic at `x_{0}`. + The solution is given by + + .. math:: y(x) = y(x_{0}) + \sum_{n = 1}^{\infty} \frac{F_{n}(x_{0},b)(x - x_{0})^n}{n!}, + + where `y(x_{0}) = b` is the value of y at the initial value of `x_{0}`. + To compute the values of the `F_{n}(x_{0},b)` the following algorithm is + followed, until the required number of terms are generated. + + 1. `F_1 = h(x_{0}, b)` + 2. `F_{n+1} = \frac{\partial F_{n}}{\partial x} + \frac{\partial F_{n}}{\partial y}F_{1}` + + Examples + ======== + + >>> from sympy import Function, pprint, exp, dsolve + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = exp(x)*(f(x).diff(x)) - f(x) + >>> pprint(dsolve(eq, hint='1st_power_series')) + 3 4 5 + C1*x C1*x C1*x / 6\ + f(x) = C1 + C1*x - ----- + ----- + ----- + O\x / + 6 24 60 + + + References + ========== + + - Travis W. Walker, Analytic power series technique for solving first-order + differential equations, p.p 17, 18 + + """ + x = func.args[0] + y = match['y'] + f = func.func + h = -match[match['d']]/match[match['e']] + point = match['f0'] + value = match['f0val'] + terms = match['terms'] + + # First term + F = h + if not h: + return Eq(f(x), value) + + # Initialization + series = value + if terms > 1: + hc = h.subs({x: point, y: value}) + if hc.has(oo) or hc.has(nan) or hc.has(zoo): + # Derivative does not exist, not analytic + return Eq(f(x), oo) + elif hc: + series += hc*(x - point) + + for factcount in range(2, terms): + Fnew = F.diff(x) + F.diff(y)*h + Fnewc = Fnew.subs({x: point, y: value}) + # Same logic as above + if Fnewc.has(oo) or Fnewc.has(nan) or Fnewc.has(-oo) or Fnewc.has(zoo): + return Eq(f(x), oo) + series += Fnewc*((x - point)**factcount)/factorial(factcount) + F = Fnew + series += Order(x**terms) + return Eq(f(x), series) + + +def checkinfsol(eq, infinitesimals, func=None, order=None): + r""" + This function is used to check if the given infinitesimals are the + actual infinitesimals of the given first order differential equation. + This method is specific to the Lie Group Solver of ODEs. + + As of now, it simply checks, by substituting the infinitesimals in the + partial differential equation. + + + .. math:: \frac{\partial \eta}{\partial x} + \left(\frac{\partial \eta}{\partial y} + - \frac{\partial \xi}{\partial x}\right)*h + - \frac{\partial \xi}{\partial y}*h^{2} + - \xi\frac{\partial h}{\partial x} - \eta\frac{\partial h}{\partial y} = 0 + + + where `\eta`, and `\xi` are the infinitesimals and `h(x,y) = \frac{dy}{dx}` + + The infinitesimals should be given in the form of a list of dicts + ``[{xi(x, y): inf, eta(x, y): inf}]``, corresponding to the + output of the function infinitesimals. It returns a list + of values of the form ``[(True/False, sol)]`` where ``sol`` is the value + obtained after substituting the infinitesimals in the PDE. If it + is ``True``, then ``sol`` would be 0. + + """ + if isinstance(eq, Equality): + eq = eq.lhs - eq.rhs + if not func: + eq, func = _preprocess(eq) + variables = func.args + if len(variables) != 1: + raise ValueError("ODE's have only one independent variable") + else: + x = variables[0] + if not order: + order = ode_order(eq, func) + if order != 1: + raise NotImplementedError("Lie groups solver has been implemented " + "only for first order differential equations") + else: + df = func.diff(x) + a = Wild('a', exclude = [df]) + b = Wild('b', exclude = [df]) + match = collect(expand(eq), df).match(a*df + b) + + if match: + h = -simplify(match[b]/match[a]) + else: + try: + sol = solve(eq, df) + except NotImplementedError: + raise NotImplementedError("Infinitesimals for the " + "first order ODE could not be found") + else: + h = sol[0] # Find infinitesimals for one solution + + y = Dummy('y') + h = h.subs(func, y) + xi = Function('xi')(x, y) + eta = Function('eta')(x, y) + dxi = Function('xi')(x, func) + deta = Function('eta')(x, func) + pde = (eta.diff(x) + (eta.diff(y) - xi.diff(x))*h - + (xi.diff(y))*h**2 - xi*(h.diff(x)) - eta*(h.diff(y))) + soltup = [] + for sol in infinitesimals: + tsol = {xi: S(sol[dxi]).subs(func, y), + eta: S(sol[deta]).subs(func, y)} + sol = simplify(pde.subs(tsol).doit()) + if sol: + soltup.append((False, sol.subs(y, func))) + else: + soltup.append((True, 0)) + return soltup + + +def sysode_linear_2eq_order1(match_): + x = match_['func'][0].func + y = match_['func'][1].func + func = match_['func'] + fc = match_['func_coeff'] + eq = match_['eq'] + r = {} + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + for i in range(2): + eq[i] = Add(*[terms/fc[i,func[i],1] for terms in Add.make_args(eq[i])]) + + # for equations Eq(a1*diff(x(t),t), a*x(t) + b*y(t) + k1) + # and Eq(a2*diff(x(t),t), c*x(t) + d*y(t) + k2) + r['a'] = -fc[0,x(t),0]/fc[0,x(t),1] + r['c'] = -fc[1,x(t),0]/fc[1,y(t),1] + r['b'] = -fc[0,y(t),0]/fc[0,x(t),1] + r['d'] = -fc[1,y(t),0]/fc[1,y(t),1] + forcing = [S.Zero,S.Zero] + for i in range(2): + for j in Add.make_args(eq[i]): + if not j.has(x(t), y(t)): + forcing[i] += j + if not (forcing[0].has(t) or forcing[1].has(t)): + r['k1'] = forcing[0] + r['k2'] = forcing[1] + else: + raise NotImplementedError("Only homogeneous problems are supported" + + " (and constant inhomogeneity)") + + if match_['type_of_equation'] == 'type6': + sol = _linear_2eq_order1_type6(x, y, t, r, eq) + if match_['type_of_equation'] == 'type7': + sol = _linear_2eq_order1_type7(x, y, t, r, eq) + return sol + +def _linear_2eq_order1_type6(x, y, t, r, eq): + r""" + The equations of this type of ode are . + + .. math:: x' = f(t) x + g(t) y + + .. math:: y' = a [f(t) + a h(t)] x + a [g(t) - h(t)] y + + This is solved by first multiplying the first equation by `-a` and adding + it to the second equation to obtain + + .. math:: y' - a x' = -a h(t) (y - a x) + + Setting `U = y - ax` and integrating the equation we arrive at + + .. math:: y - ax = C_1 e^{-a \int h(t) \,dt} + + and on substituting the value of y in first equation give rise to first order ODEs. After solving for + `x`, we can obtain `y` by substituting the value of `x` in second equation. + + """ + C1, C2, C3, C4 = get_numbered_constants(eq, num=4) + p = 0 + q = 0 + p1 = cancel(r['c']/cancel(r['c']/r['d']).as_numer_denom()[0]) + p2 = cancel(r['a']/cancel(r['a']/r['b']).as_numer_denom()[0]) + for n, i in enumerate([p1, p2]): + for j in Mul.make_args(collect_const(i)): + if not j.has(t): + q = j + if q!=0 and n==0: + if ((r['c']/j - r['a'])/(r['b'] - r['d']/j)) == j: + p = 1 + s = j + break + if q!=0 and n==1: + if ((r['a']/j - r['c'])/(r['d'] - r['b']/j)) == j: + p = 2 + s = j + break + + if p == 1: + equ = diff(x(t),t) - r['a']*x(t) - r['b']*(s*x(t) + C1*exp(-s*Integral(r['b'] - r['d']/s, t))) + hint1 = classify_ode(equ)[1] + sol1 = dsolve(equ, hint=hint1+'_Integral').rhs + sol2 = s*sol1 + C1*exp(-s*Integral(r['b'] - r['d']/s, t)) + elif p ==2: + equ = diff(y(t),t) - r['c']*y(t) - r['d']*s*y(t) + C1*exp(-s*Integral(r['d'] - r['b']/s, t)) + hint1 = classify_ode(equ)[1] + sol2 = dsolve(equ, hint=hint1+'_Integral').rhs + sol1 = s*sol2 + C1*exp(-s*Integral(r['d'] - r['b']/s, t)) + return [Eq(x(t), sol1), Eq(y(t), sol2)] + +def _linear_2eq_order1_type7(x, y, t, r, eq): + r""" + The equations of this type of ode are . + + .. math:: x' = f(t) x + g(t) y + + .. math:: y' = h(t) x + p(t) y + + Differentiating the first equation and substituting the value of `y` + from second equation will give a second-order linear equation + + .. math:: g x'' - (fg + gp + g') x' + (fgp - g^{2} h + f g' - f' g) x = 0 + + This above equation can be easily integrated if following conditions are satisfied. + + 1. `fgp - g^{2} h + f g' - f' g = 0` + + 2. `fgp - g^{2} h + f g' - f' g = ag, fg + gp + g' = bg` + + If first condition is satisfied then it is solved by current dsolve solver and in second case it becomes + a constant coefficient differential equation which is also solved by current solver. + + Otherwise if the above condition fails then, + a particular solution is assumed as `x = x_0(t)` and `y = y_0(t)` + Then the general solution is expressed as + + .. math:: x = C_1 x_0(t) + C_2 x_0(t) \int \frac{g(t) F(t) P(t)}{x_0^{2}(t)} \,dt + + .. math:: y = C_1 y_0(t) + C_2 [\frac{F(t) P(t)}{x_0(t)} + y_0(t) \int \frac{g(t) F(t) P(t)}{x_0^{2}(t)} \,dt] + + where C1 and C2 are arbitrary constants and + + .. math:: F(t) = e^{\int f(t) \,dt}, P(t) = e^{\int p(t) \,dt} + + """ + C1, C2, C3, C4 = get_numbered_constants(eq, num=4) + e1 = r['a']*r['b']*r['c'] - r['b']**2*r['c'] + r['a']*diff(r['b'],t) - diff(r['a'],t)*r['b'] + e2 = r['a']*r['c']*r['d'] - r['b']*r['c']**2 + diff(r['c'],t)*r['d'] - r['c']*diff(r['d'],t) + m1 = r['a']*r['b'] + r['b']*r['d'] + diff(r['b'],t) + m2 = r['a']*r['c'] + r['c']*r['d'] + diff(r['c'],t) + if e1 == 0: + sol1 = dsolve(r['b']*diff(x(t),t,t) - m1*diff(x(t),t)).rhs + sol2 = dsolve(diff(y(t),t) - r['c']*sol1 - r['d']*y(t)).rhs + elif e2 == 0: + sol2 = dsolve(r['c']*diff(y(t),t,t) - m2*diff(y(t),t)).rhs + sol1 = dsolve(diff(x(t),t) - r['a']*x(t) - r['b']*sol2).rhs + elif not (e1/r['b']).has(t) and not (m1/r['b']).has(t): + sol1 = dsolve(diff(x(t),t,t) - (m1/r['b'])*diff(x(t),t) - (e1/r['b'])*x(t)).rhs + sol2 = dsolve(diff(y(t),t) - r['c']*sol1 - r['d']*y(t)).rhs + elif not (e2/r['c']).has(t) and not (m2/r['c']).has(t): + sol2 = dsolve(diff(y(t),t,t) - (m2/r['c'])*diff(y(t),t) - (e2/r['c'])*y(t)).rhs + sol1 = dsolve(diff(x(t),t) - r['a']*x(t) - r['b']*sol2).rhs + else: + x0 = Function('x0')(t) # x0 and y0 being particular solutions + y0 = Function('y0')(t) + F = exp(Integral(r['a'],t)) + P = exp(Integral(r['d'],t)) + sol1 = C1*x0 + C2*x0*Integral(r['b']*F*P/x0**2, t) + sol2 = C1*y0 + C2*(F*P/x0 + y0*Integral(r['b']*F*P/x0**2, t)) + return [Eq(x(t), sol1), Eq(y(t), sol2)] + + +def sysode_nonlinear_2eq_order1(match_): + func = match_['func'] + eq = match_['eq'] + fc = match_['func_coeff'] + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + if match_['type_of_equation'] == 'type5': + sol = _nonlinear_2eq_order1_type5(func, t, eq) + return sol + x = func[0].func + y = func[1].func + for i in range(2): + eqs = 0 + for terms in Add.make_args(eq[i]): + eqs += terms/fc[i,func[i],1] + eq[i] = eqs + if match_['type_of_equation'] == 'type1': + sol = _nonlinear_2eq_order1_type1(x, y, t, eq) + elif match_['type_of_equation'] == 'type2': + sol = _nonlinear_2eq_order1_type2(x, y, t, eq) + elif match_['type_of_equation'] == 'type3': + sol = _nonlinear_2eq_order1_type3(x, y, t, eq) + elif match_['type_of_equation'] == 'type4': + sol = _nonlinear_2eq_order1_type4(x, y, t, eq) + return sol + + +def _nonlinear_2eq_order1_type1(x, y, t, eq): + r""" + Equations: + + .. math:: x' = x^n F(x,y) + + .. math:: y' = g(y) F(x,y) + + Solution: + + .. math:: x = \varphi(y), \int \frac{1}{g(y) F(\varphi(y),y)} \,dy = t + C_2 + + where + + if `n \neq 1` + + .. math:: \varphi = [C_1 + (1-n) \int \frac{1}{g(y)} \,dy]^{\frac{1}{1-n}} + + if `n = 1` + + .. math:: \varphi = C_1 e^{\int \frac{1}{g(y)} \,dy} + + where `C_1` and `C_2` are arbitrary constants. + + """ + C1, C2 = get_numbered_constants(eq, num=2) + n = Wild('n', exclude=[x(t),y(t)]) + f = Wild('f') + u, v = symbols('u, v') + r = eq[0].match(diff(x(t),t) - x(t)**n*f) + g = ((diff(y(t),t) - eq[1])/r[f]).subs(y(t),v) + F = r[f].subs(x(t),u).subs(y(t),v) + n = r[n] + if n!=1: + phi = (C1 + (1-n)*Integral(1/g, v))**(1/(1-n)) + else: + phi = C1*exp(Integral(1/g, v)) + phi = phi.doit() + sol2 = solve(Integral(1/(g*F.subs(u,phi)), v).doit() - t - C2, v) + sol = [] + for sols in sol2: + sol.append(Eq(x(t),phi.subs(v, sols))) + sol.append(Eq(y(t), sols)) + return sol + +def _nonlinear_2eq_order1_type2(x, y, t, eq): + r""" + Equations: + + .. math:: x' = e^{\lambda x} F(x,y) + + .. math:: y' = g(y) F(x,y) + + Solution: + + .. math:: x = \varphi(y), \int \frac{1}{g(y) F(\varphi(y),y)} \,dy = t + C_2 + + where + + if `\lambda \neq 0` + + .. math:: \varphi = -\frac{1}{\lambda} log(C_1 - \lambda \int \frac{1}{g(y)} \,dy) + + if `\lambda = 0` + + .. math:: \varphi = C_1 + \int \frac{1}{g(y)} \,dy + + where `C_1` and `C_2` are arbitrary constants. + + """ + C1, C2 = get_numbered_constants(eq, num=2) + n = Wild('n', exclude=[x(t),y(t)]) + f = Wild('f') + u, v = symbols('u, v') + r = eq[0].match(diff(x(t),t) - exp(n*x(t))*f) + g = ((diff(y(t),t) - eq[1])/r[f]).subs(y(t),v) + F = r[f].subs(x(t),u).subs(y(t),v) + n = r[n] + if n: + phi = -1/n*log(C1 - n*Integral(1/g, v)) + else: + phi = C1 + Integral(1/g, v) + phi = phi.doit() + sol2 = solve(Integral(1/(g*F.subs(u,phi)), v).doit() - t - C2, v) + sol = [] + for sols in sol2: + sol.append(Eq(x(t),phi.subs(v, sols))) + sol.append(Eq(y(t), sols)) + return sol + +def _nonlinear_2eq_order1_type3(x, y, t, eq): + r""" + Autonomous system of general form + + .. math:: x' = F(x,y) + + .. math:: y' = G(x,y) + + Assuming `y = y(x, C_1)` where `C_1` is an arbitrary constant is the general + solution of the first-order equation + + .. math:: F(x,y) y'_x = G(x,y) + + Then the general solution of the original system of equations has the form + + .. math:: \int \frac{1}{F(x,y(x,C_1))} \,dx = t + C_1 + + """ + C1, C2, C3, C4 = get_numbered_constants(eq, num=4) + v = Function('v') + u = Symbol('u') + f = Wild('f') + g = Wild('g') + r1 = eq[0].match(diff(x(t),t) - f) + r2 = eq[1].match(diff(y(t),t) - g) + F = r1[f].subs(x(t), u).subs(y(t), v(u)) + G = r2[g].subs(x(t), u).subs(y(t), v(u)) + sol2r = dsolve(Eq(diff(v(u), u), G/F)) + if isinstance(sol2r, Equality): + sol2r = [sol2r] + for sol2s in sol2r: + sol1 = solve(Integral(1/F.subs(v(u), sol2s.rhs), u).doit() - t - C2, u) + sol = [] + for sols in sol1: + sol.append(Eq(x(t), sols)) + sol.append(Eq(y(t), (sol2s.rhs).subs(u, sols))) + return sol + +def _nonlinear_2eq_order1_type4(x, y, t, eq): + r""" + Equation: + + .. math:: x' = f_1(x) g_1(y) \phi(x,y,t) + + .. math:: y' = f_2(x) g_2(y) \phi(x,y,t) + + First integral: + + .. math:: \int \frac{f_2(x)}{f_1(x)} \,dx - \int \frac{g_1(y)}{g_2(y)} \,dy = C + + where `C` is an arbitrary constant. + + On solving the first integral for `x` (resp., `y` ) and on substituting the + resulting expression into either equation of the original solution, one + arrives at a first-order equation for determining `y` (resp., `x` ). + + """ + C1, C2 = get_numbered_constants(eq, num=2) + u, v = symbols('u, v') + U, V = symbols('U, V', cls=Function) + f = Wild('f') + g = Wild('g') + f1 = Wild('f1', exclude=[v,t]) + f2 = Wild('f2', exclude=[v,t]) + g1 = Wild('g1', exclude=[u,t]) + g2 = Wild('g2', exclude=[u,t]) + r1 = eq[0].match(diff(x(t),t) - f) + r2 = eq[1].match(diff(y(t),t) - g) + num, den = ( + (r1[f].subs(x(t),u).subs(y(t),v))/ + (r2[g].subs(x(t),u).subs(y(t),v))).as_numer_denom() + R1 = num.match(f1*g1) + R2 = den.match(f2*g2) + phi = (r1[f].subs(x(t),u).subs(y(t),v))/num + F1 = R1[f1]; F2 = R2[f2] + G1 = R1[g1]; G2 = R2[g2] + sol1r = solve(Integral(F2/F1, u).doit() - Integral(G1/G2,v).doit() - C1, u) + sol2r = solve(Integral(F2/F1, u).doit() - Integral(G1/G2,v).doit() - C1, v) + sol = [] + for sols in sol1r: + sol.append(Eq(y(t), dsolve(diff(V(t),t) - F2.subs(u,sols).subs(v,V(t))*G2.subs(v,V(t))*phi.subs(u,sols).subs(v,V(t))).rhs)) + for sols in sol2r: + sol.append(Eq(x(t), dsolve(diff(U(t),t) - F1.subs(u,U(t))*G1.subs(v,sols).subs(u,U(t))*phi.subs(v,sols).subs(u,U(t))).rhs)) + return set(sol) + +def _nonlinear_2eq_order1_type5(func, t, eq): + r""" + Clairaut system of ODEs + + .. math:: x = t x' + F(x',y') + + .. math:: y = t y' + G(x',y') + + The following are solutions of the system + + `(i)` straight lines: + + .. math:: x = C_1 t + F(C_1, C_2), y = C_2 t + G(C_1, C_2) + + where `C_1` and `C_2` are arbitrary constants; + + `(ii)` envelopes of the above lines; + + `(iii)` continuously differentiable lines made up from segments of the lines + `(i)` and `(ii)`. + + """ + C1, C2 = get_numbered_constants(eq, num=2) + f = Wild('f') + g = Wild('g') + def check_type(x, y): + r1 = eq[0].match(t*diff(x(t),t) - x(t) + f) + r2 = eq[1].match(t*diff(y(t),t) - y(t) + g) + if not (r1 and r2): + r1 = eq[0].match(diff(x(t),t) - x(t)/t + f/t) + r2 = eq[1].match(diff(y(t),t) - y(t)/t + g/t) + if not (r1 and r2): + r1 = (-eq[0]).match(t*diff(x(t),t) - x(t) + f) + r2 = (-eq[1]).match(t*diff(y(t),t) - y(t) + g) + if not (r1 and r2): + r1 = (-eq[0]).match(diff(x(t),t) - x(t)/t + f/t) + r2 = (-eq[1]).match(diff(y(t),t) - y(t)/t + g/t) + return [r1, r2] + for func_ in func: + if isinstance(func_, list): + x = func[0][0].func + y = func[0][1].func + [r1, r2] = check_type(x, y) + if not (r1 and r2): + [r1, r2] = check_type(y, x) + x, y = y, x + x1 = diff(x(t),t); y1 = diff(y(t),t) + return {Eq(x(t), C1*t + r1[f].subs(x1,C1).subs(y1,C2)), Eq(y(t), C2*t + r2[g].subs(x1,C1).subs(y1,C2))} + +def sysode_nonlinear_3eq_order1(match_): + x = match_['func'][0].func + y = match_['func'][1].func + z = match_['func'][2].func + eq = match_['eq'] + t = list(list(eq[0].atoms(Derivative))[0].atoms(Symbol))[0] + if match_['type_of_equation'] == 'type1': + sol = _nonlinear_3eq_order1_type1(x, y, z, t, eq) + if match_['type_of_equation'] == 'type2': + sol = _nonlinear_3eq_order1_type2(x, y, z, t, eq) + if match_['type_of_equation'] == 'type3': + sol = _nonlinear_3eq_order1_type3(x, y, z, t, eq) + if match_['type_of_equation'] == 'type4': + sol = _nonlinear_3eq_order1_type4(x, y, z, t, eq) + if match_['type_of_equation'] == 'type5': + sol = _nonlinear_3eq_order1_type5(x, y, z, t, eq) + return sol + +def _nonlinear_3eq_order1_type1(x, y, z, t, eq): + r""" + Equations: + + .. math:: a x' = (b - c) y z, \enspace b y' = (c - a) z x, \enspace c z' = (a - b) x y + + First Integrals: + + .. math:: a x^{2} + b y^{2} + c z^{2} = C_1 + + .. math:: a^{2} x^{2} + b^{2} y^{2} + c^{2} z^{2} = C_2 + + where `C_1` and `C_2` are arbitrary constants. On solving the integrals for `y` and + `z` and on substituting the resulting expressions into the first equation of the + system, we arrives at a separable first-order equation on `x`. Similarly doing that + for other two equations, we will arrive at first order equation on `y` and `z` too. + + References + ========== + -https://eqworld.ipmnet.ru/en/solutions/sysode/sode0401.pdf + + """ + C1, C2 = get_numbered_constants(eq, num=2) + u, v, w = symbols('u, v, w') + p = Wild('p', exclude=[x(t), y(t), z(t), t]) + q = Wild('q', exclude=[x(t), y(t), z(t), t]) + s = Wild('s', exclude=[x(t), y(t), z(t), t]) + r = (diff(x(t),t) - eq[0]).match(p*y(t)*z(t)) + r.update((diff(y(t),t) - eq[1]).match(q*z(t)*x(t))) + r.update((diff(z(t),t) - eq[2]).match(s*x(t)*y(t))) + n1, d1 = r[p].as_numer_denom() + n2, d2 = r[q].as_numer_denom() + n3, d3 = r[s].as_numer_denom() + val = solve([n1*u-d1*v+d1*w, d2*u+n2*v-d2*w, d3*u-d3*v-n3*w],[u,v]) + vals = [val[v], val[u]] + c = lcm(vals[0].as_numer_denom()[1], vals[1].as_numer_denom()[1]) + b = vals[0].subs(w, c) + a = vals[1].subs(w, c) + y_x = sqrt(((c*C1-C2) - a*(c-a)*x(t)**2)/(b*(c-b))) + z_x = sqrt(((b*C1-C2) - a*(b-a)*x(t)**2)/(c*(b-c))) + z_y = sqrt(((a*C1-C2) - b*(a-b)*y(t)**2)/(c*(a-c))) + x_y = sqrt(((c*C1-C2) - b*(c-b)*y(t)**2)/(a*(c-a))) + x_z = sqrt(((b*C1-C2) - c*(b-c)*z(t)**2)/(a*(b-a))) + y_z = sqrt(((a*C1-C2) - c*(a-c)*z(t)**2)/(b*(a-b))) + sol1 = dsolve(a*diff(x(t),t) - (b-c)*y_x*z_x) + sol2 = dsolve(b*diff(y(t),t) - (c-a)*z_y*x_y) + sol3 = dsolve(c*diff(z(t),t) - (a-b)*x_z*y_z) + return [sol1, sol2, sol3] + + +def _nonlinear_3eq_order1_type2(x, y, z, t, eq): + r""" + Equations: + + .. math:: a x' = (b - c) y z f(x, y, z, t) + + .. math:: b y' = (c - a) z x f(x, y, z, t) + + .. math:: c z' = (a - b) x y f(x, y, z, t) + + First Integrals: + + .. math:: a x^{2} + b y^{2} + c z^{2} = C_1 + + .. math:: a^{2} x^{2} + b^{2} y^{2} + c^{2} z^{2} = C_2 + + where `C_1` and `C_2` are arbitrary constants. On solving the integrals for `y` and + `z` and on substituting the resulting expressions into the first equation of the + system, we arrives at a first-order differential equations on `x`. Similarly doing + that for other two equations we will arrive at first order equation on `y` and `z`. + + References + ========== + -https://eqworld.ipmnet.ru/en/solutions/sysode/sode0402.pdf + + """ + C1, C2 = get_numbered_constants(eq, num=2) + u, v, w = symbols('u, v, w') + p = Wild('p', exclude=[x(t), y(t), z(t), t]) + q = Wild('q', exclude=[x(t), y(t), z(t), t]) + s = Wild('s', exclude=[x(t), y(t), z(t), t]) + f = Wild('f') + r1 = (diff(x(t),t) - eq[0]).match(y(t)*z(t)*f) + r = collect_const(r1[f]).match(p*f) + r.update(((diff(y(t),t) - eq[1])/r[f]).match(q*z(t)*x(t))) + r.update(((diff(z(t),t) - eq[2])/r[f]).match(s*x(t)*y(t))) + n1, d1 = r[p].as_numer_denom() + n2, d2 = r[q].as_numer_denom() + n3, d3 = r[s].as_numer_denom() + val = solve([n1*u-d1*v+d1*w, d2*u+n2*v-d2*w, -d3*u+d3*v+n3*w],[u,v]) + vals = [val[v], val[u]] + c = lcm(vals[0].as_numer_denom()[1], vals[1].as_numer_denom()[1]) + a = vals[0].subs(w, c) + b = vals[1].subs(w, c) + y_x = sqrt(((c*C1-C2) - a*(c-a)*x(t)**2)/(b*(c-b))) + z_x = sqrt(((b*C1-C2) - a*(b-a)*x(t)**2)/(c*(b-c))) + z_y = sqrt(((a*C1-C2) - b*(a-b)*y(t)**2)/(c*(a-c))) + x_y = sqrt(((c*C1-C2) - b*(c-b)*y(t)**2)/(a*(c-a))) + x_z = sqrt(((b*C1-C2) - c*(b-c)*z(t)**2)/(a*(b-a))) + y_z = sqrt(((a*C1-C2) - c*(a-c)*z(t)**2)/(b*(a-b))) + sol1 = dsolve(a*diff(x(t),t) - (b-c)*y_x*z_x*r[f]) + sol2 = dsolve(b*diff(y(t),t) - (c-a)*z_y*x_y*r[f]) + sol3 = dsolve(c*diff(z(t),t) - (a-b)*x_z*y_z*r[f]) + return [sol1, sol2, sol3] + +def _nonlinear_3eq_order1_type3(x, y, z, t, eq): + r""" + Equations: + + .. math:: x' = c F_2 - b F_3, \enspace y' = a F_3 - c F_1, \enspace z' = b F_1 - a F_2 + + where `F_n = F_n(x, y, z, t)`. + + 1. First Integral: + + .. math:: a x + b y + c z = C_1, + + where C is an arbitrary constant. + + 2. If we assume function `F_n` to be independent of `t`,i.e, `F_n` = `F_n (x, y, z)` + Then, on eliminating `t` and `z` from the first two equation of the system, one + arrives at the first-order equation + + .. math:: \frac{dy}{dx} = \frac{a F_3 (x, y, z) - c F_1 (x, y, z)}{c F_2 (x, y, z) - + b F_3 (x, y, z)} + + where `z = \frac{1}{c} (C_1 - a x - b y)` + + References + ========== + -https://eqworld.ipmnet.ru/en/solutions/sysode/sode0404.pdf + + """ + C1 = get_numbered_constants(eq, num=1) + u, v, w = symbols('u, v, w') + fu, fv, fw = symbols('u, v, w', cls=Function) + p = Wild('p', exclude=[x(t), y(t), z(t), t]) + q = Wild('q', exclude=[x(t), y(t), z(t), t]) + s = Wild('s', exclude=[x(t), y(t), z(t), t]) + F1, F2, F3 = symbols('F1, F2, F3', cls=Wild) + r1 = (diff(x(t), t) - eq[0]).match(F2-F3) + r = collect_const(r1[F2]).match(s*F2) + r.update(collect_const(r1[F3]).match(q*F3)) + if eq[1].has(r[F2]) and not eq[1].has(r[F3]): + r[F2], r[F3] = r[F3], r[F2] + r[s], r[q] = -r[q], -r[s] + r.update((diff(y(t), t) - eq[1]).match(p*r[F3] - r[s]*F1)) + a = r[p]; b = r[q]; c = r[s] + F1 = r[F1].subs(x(t), u).subs(y(t),v).subs(z(t), w) + F2 = r[F2].subs(x(t), u).subs(y(t),v).subs(z(t), w) + F3 = r[F3].subs(x(t), u).subs(y(t),v).subs(z(t), w) + z_xy = (C1-a*u-b*v)/c + y_zx = (C1-a*u-c*w)/b + x_yz = (C1-b*v-c*w)/a + y_x = dsolve(diff(fv(u),u) - ((a*F3-c*F1)/(c*F2-b*F3)).subs(w,z_xy).subs(v,fv(u))).rhs + z_x = dsolve(diff(fw(u),u) - ((b*F1-a*F2)/(c*F2-b*F3)).subs(v,y_zx).subs(w,fw(u))).rhs + z_y = dsolve(diff(fw(v),v) - ((b*F1-a*F2)/(a*F3-c*F1)).subs(u,x_yz).subs(w,fw(v))).rhs + x_y = dsolve(diff(fu(v),v) - ((c*F2-b*F3)/(a*F3-c*F1)).subs(w,z_xy).subs(u,fu(v))).rhs + y_z = dsolve(diff(fv(w),w) - ((a*F3-c*F1)/(b*F1-a*F2)).subs(u,x_yz).subs(v,fv(w))).rhs + x_z = dsolve(diff(fu(w),w) - ((c*F2-b*F3)/(b*F1-a*F2)).subs(v,y_zx).subs(u,fu(w))).rhs + sol1 = dsolve(diff(fu(t),t) - (c*F2 - b*F3).subs(v,y_x).subs(w,z_x).subs(u,fu(t))).rhs + sol2 = dsolve(diff(fv(t),t) - (a*F3 - c*F1).subs(u,x_y).subs(w,z_y).subs(v,fv(t))).rhs + sol3 = dsolve(diff(fw(t),t) - (b*F1 - a*F2).subs(u,x_z).subs(v,y_z).subs(w,fw(t))).rhs + return [sol1, sol2, sol3] + +def _nonlinear_3eq_order1_type4(x, y, z, t, eq): + r""" + Equations: + + .. math:: x' = c z F_2 - b y F_3, \enspace y' = a x F_3 - c z F_1, \enspace z' = b y F_1 - a x F_2 + + where `F_n = F_n (x, y, z, t)` + + 1. First integral: + + .. math:: a x^{2} + b y^{2} + c z^{2} = C_1 + + where `C` is an arbitrary constant. + + 2. Assuming the function `F_n` is independent of `t`: `F_n = F_n (x, y, z)`. Then on + eliminating `t` and `z` from the first two equations of the system, one arrives at + the first-order equation + + .. math:: \frac{dy}{dx} = \frac{a x F_3 (x, y, z) - c z F_1 (x, y, z)} + {c z F_2 (x, y, z) - b y F_3 (x, y, z)} + + where `z = \pm \sqrt{\frac{1}{c} (C_1 - a x^{2} - b y^{2})}` + + References + ========== + -https://eqworld.ipmnet.ru/en/solutions/sysode/sode0405.pdf + + """ + C1 = get_numbered_constants(eq, num=1) + u, v, w = symbols('u, v, w') + p = Wild('p', exclude=[x(t), y(t), z(t), t]) + q = Wild('q', exclude=[x(t), y(t), z(t), t]) + s = Wild('s', exclude=[x(t), y(t), z(t), t]) + F1, F2, F3 = symbols('F1, F2, F3', cls=Wild) + r1 = eq[0].match(diff(x(t),t) - z(t)*F2 + y(t)*F3) + r = collect_const(r1[F2]).match(s*F2) + r.update(collect_const(r1[F3]).match(q*F3)) + if eq[1].has(r[F2]) and not eq[1].has(r[F3]): + r[F2], r[F3] = r[F3], r[F2] + r[s], r[q] = -r[q], -r[s] + r.update((diff(y(t),t) - eq[1]).match(p*x(t)*r[F3] - r[s]*z(t)*F1)) + a = r[p]; b = r[q]; c = r[s] + F1 = r[F1].subs(x(t),u).subs(y(t),v).subs(z(t),w) + F2 = r[F2].subs(x(t),u).subs(y(t),v).subs(z(t),w) + F3 = r[F3].subs(x(t),u).subs(y(t),v).subs(z(t),w) + x_yz = sqrt((C1 - b*v**2 - c*w**2)/a) + y_zx = sqrt((C1 - c*w**2 - a*u**2)/b) + z_xy = sqrt((C1 - a*u**2 - b*v**2)/c) + y_x = dsolve(diff(v(u),u) - ((a*u*F3-c*w*F1)/(c*w*F2-b*v*F3)).subs(w,z_xy).subs(v,v(u))).rhs + z_x = dsolve(diff(w(u),u) - ((b*v*F1-a*u*F2)/(c*w*F2-b*v*F3)).subs(v,y_zx).subs(w,w(u))).rhs + z_y = dsolve(diff(w(v),v) - ((b*v*F1-a*u*F2)/(a*u*F3-c*w*F1)).subs(u,x_yz).subs(w,w(v))).rhs + x_y = dsolve(diff(u(v),v) - ((c*w*F2-b*v*F3)/(a*u*F3-c*w*F1)).subs(w,z_xy).subs(u,u(v))).rhs + y_z = dsolve(diff(v(w),w) - ((a*u*F3-c*w*F1)/(b*v*F1-a*u*F2)).subs(u,x_yz).subs(v,v(w))).rhs + x_z = dsolve(diff(u(w),w) - ((c*w*F2-b*v*F3)/(b*v*F1-a*u*F2)).subs(v,y_zx).subs(u,u(w))).rhs + sol1 = dsolve(diff(u(t),t) - (c*w*F2 - b*v*F3).subs(v,y_x).subs(w,z_x).subs(u,u(t))).rhs + sol2 = dsolve(diff(v(t),t) - (a*u*F3 - c*w*F1).subs(u,x_y).subs(w,z_y).subs(v,v(t))).rhs + sol3 = dsolve(diff(w(t),t) - (b*v*F1 - a*u*F2).subs(u,x_z).subs(v,y_z).subs(w,w(t))).rhs + return [sol1, sol2, sol3] + +def _nonlinear_3eq_order1_type5(x, y, z, t, eq): + r""" + .. math:: x' = x (c F_2 - b F_3), \enspace y' = y (a F_3 - c F_1), \enspace z' = z (b F_1 - a F_2) + + where `F_n = F_n (x, y, z, t)` and are arbitrary functions. + + First Integral: + + .. math:: \left|x\right|^{a} \left|y\right|^{b} \left|z\right|^{c} = C_1 + + where `C` is an arbitrary constant. If the function `F_n` is independent of `t`, + then, by eliminating `t` and `z` from the first two equations of the system, one + arrives at a first-order equation. + + References + ========== + -https://eqworld.ipmnet.ru/en/solutions/sysode/sode0406.pdf + + """ + C1 = get_numbered_constants(eq, num=1) + u, v, w = symbols('u, v, w') + fu, fv, fw = symbols('u, v, w', cls=Function) + p = Wild('p', exclude=[x(t), y(t), z(t), t]) + q = Wild('q', exclude=[x(t), y(t), z(t), t]) + s = Wild('s', exclude=[x(t), y(t), z(t), t]) + F1, F2, F3 = symbols('F1, F2, F3', cls=Wild) + r1 = eq[0].match(diff(x(t), t) - x(t)*F2 + x(t)*F3) + r = collect_const(r1[F2]).match(s*F2) + r.update(collect_const(r1[F3]).match(q*F3)) + if eq[1].has(r[F2]) and not eq[1].has(r[F3]): + r[F2], r[F3] = r[F3], r[F2] + r[s], r[q] = -r[q], -r[s] + r.update((diff(y(t), t) - eq[1]).match(y(t)*(p*r[F3] - r[s]*F1))) + a = r[p]; b = r[q]; c = r[s] + F1 = r[F1].subs(x(t), u).subs(y(t), v).subs(z(t), w) + F2 = r[F2].subs(x(t), u).subs(y(t), v).subs(z(t), w) + F3 = r[F3].subs(x(t), u).subs(y(t), v).subs(z(t), w) + x_yz = (C1*v**-b*w**-c)**-a + y_zx = (C1*w**-c*u**-a)**-b + z_xy = (C1*u**-a*v**-b)**-c + y_x = dsolve(diff(fv(u), u) - ((v*(a*F3 - c*F1))/(u*(c*F2 - b*F3))).subs(w, z_xy).subs(v, fv(u))).rhs + z_x = dsolve(diff(fw(u), u) - ((w*(b*F1 - a*F2))/(u*(c*F2 - b*F3))).subs(v, y_zx).subs(w, fw(u))).rhs + z_y = dsolve(diff(fw(v), v) - ((w*(b*F1 - a*F2))/(v*(a*F3 - c*F1))).subs(u, x_yz).subs(w, fw(v))).rhs + x_y = dsolve(diff(fu(v), v) - ((u*(c*F2 - b*F3))/(v*(a*F3 - c*F1))).subs(w, z_xy).subs(u, fu(v))).rhs + y_z = dsolve(diff(fv(w), w) - ((v*(a*F3 - c*F1))/(w*(b*F1 - a*F2))).subs(u, x_yz).subs(v, fv(w))).rhs + x_z = dsolve(diff(fu(w), w) - ((u*(c*F2 - b*F3))/(w*(b*F1 - a*F2))).subs(v, y_zx).subs(u, fu(w))).rhs + sol1 = dsolve(diff(fu(t), t) - (u*(c*F2 - b*F3)).subs(v, y_x).subs(w, z_x).subs(u, fu(t))).rhs + sol2 = dsolve(diff(fv(t), t) - (v*(a*F3 - c*F1)).subs(u, x_y).subs(w, z_y).subs(v, fv(t))).rhs + sol3 = dsolve(diff(fw(t), t) - (w*(b*F1 - a*F2)).subs(u, x_z).subs(v, y_z).subs(w, fw(t))).rhs + return [sol1, sol2, sol3] + + +#This import is written at the bottom to avoid circular imports. +from .single import SingleODEProblem, SingleODESolver, solver_map diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/riccati.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/riccati.py new file mode 100644 index 0000000000000000000000000000000000000000..2ef66ed0896d39bee8fba1b74a0c93734742fc1f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/riccati.py @@ -0,0 +1,893 @@ +r""" +This module contains :py:meth:`~sympy.solvers.ode.riccati.solve_riccati`, +a function which gives all rational particular solutions to first order +Riccati ODEs. A general first order Riccati ODE is given by - + +.. math:: y' = b_0(x) + b_1(x)w + b_2(x)w^2 + +where `b_0, b_1` and `b_2` can be arbitrary rational functions of `x` +with `b_2 \ne 0`. When `b_2 = 0`, the equation is not a Riccati ODE +anymore and becomes a Linear ODE. Similarly, when `b_0 = 0`, the equation +is a Bernoulli ODE. The algorithm presented below can find rational +solution(s) to all ODEs with `b_2 \ne 0` that have a rational solution, +or prove that no rational solution exists for the equation. + +Background +========== + +A Riccati equation can be transformed to its normal form + +.. math:: y' + y^2 = a(x) + +using the transformation + +.. math:: y = -b_2(x) - \frac{b'_2(x)}{2 b_2(x)} - \frac{b_1(x)}{2} + +where `a(x)` is given by + +.. math:: a(x) = \frac{1}{4}\left(\frac{b_2'}{b_2} + b_1\right)^2 - \frac{1}{2}\left(\frac{b_2'}{b_2} + b_1\right)' - b_0 b_2 + +Thus, we can develop an algorithm to solve for the Riccati equation +in its normal form, which would in turn give us the solution for +the original Riccati equation. + +Algorithm +========= + +The algorithm implemented here is presented in the Ph.D thesis +"Rational and Algebraic Solutions of First-Order Algebraic ODEs" +by N. Thieu Vo. The entire thesis can be found here - +https://www3.risc.jku.at/publications/download/risc_5387/PhDThesisThieu.pdf + +We have only implemented the Rational Riccati solver (Algorithm 11, +Pg 78-82 in Thesis). Before we proceed towards the implementation +of the algorithm, a few definitions to understand are - + +1. Valuation of a Rational Function at `\infty`: + The valuation of a rational function `p(x)` at `\infty` is equal + to the difference between the degree of the denominator and the + numerator of `p(x)`. + + NOTE: A general definition of valuation of a rational function + at any value of `x` can be found in Pg 63 of the thesis, but + is not of any interest for this algorithm. + +2. Zeros and Poles of a Rational Function: + Let `a(x) = \frac{S(x)}{T(x)}, T \ne 0` be a rational function + of `x`. Then - + + a. The Zeros of `a(x)` are the roots of `S(x)`. + b. The Poles of `a(x)` are the roots of `T(x)`. However, `\infty` + can also be a pole of a(x). We say that `a(x)` has a pole at + `\infty` if `a(\frac{1}{x})` has a pole at 0. + +Every pole is associated with an order that is equal to the multiplicity +of its appearance as a root of `T(x)`. A pole is called a simple pole if +it has an order 1. Similarly, a pole is called a multiple pole if it has +an order `\ge` 2. + +Necessary Conditions +==================== + +For a Riccati equation in its normal form, + +.. math:: y' + y^2 = a(x) + +we can define + +a. A pole is called a movable pole if it is a pole of `y(x)` and is not +a pole of `a(x)`. +b. Similarly, a pole is called a non-movable pole if it is a pole of both +`y(x)` and `a(x)`. + +Then, the algorithm states that a rational solution exists only if - + +a. Every pole of `a(x)` must be either a simple pole or a multiple pole +of even order. +b. The valuation of `a(x)` at `\infty` must be even or be `\ge` 2. + +This algorithm finds all possible rational solutions for the Riccati ODE. +If no rational solutions are found, it means that no rational solutions +exist. + +The algorithm works for Riccati ODEs where the coefficients are rational +functions in the independent variable `x` with rational number coefficients +i.e. in `Q(x)`. The coefficients in the rational function cannot be floats, +irrational numbers, symbols or any other kind of expression. The reasons +for this are - + +1. When using symbols, different symbols could take the same value and this +would affect the multiplicity of poles if symbols are present here. + +2. An integer degree bound is required to calculate a polynomial solution +to an auxiliary differential equation, which in turn gives the particular +solution for the original ODE. If symbols/floats/irrational numbers are +present, we cannot determine if the expression for the degree bound is an +integer or not. + +Solution +======== + +With these definitions, we can state a general form for the solution of +the equation. `y(x)` must have the form - + +.. math:: y(x) = \sum_{i=1}^{n} \sum_{j=1}^{r_i} \frac{c_{ij}}{(x - x_i)^j} + \sum_{i=1}^{m} \frac{1}{x - \chi_i} + \sum_{i=0}^{N} d_i x^i + +where `x_1, x_2, \dots, x_n` are non-movable poles of `a(x)`, +`\chi_1, \chi_2, \dots, \chi_m` are movable poles of `a(x)`, and the values +of `N, n, r_1, r_2, \dots, r_n` can be determined from `a(x)`. The +coefficient vectors `(d_0, d_1, \dots, d_N)` and `(c_{i1}, c_{i2}, \dots, c_{i r_i})` +can be determined from `a(x)`. We will have 2 choices each of these vectors +and part of the procedure is figuring out which of the 2 should be used +to get the solution correctly. + +Implementation +============== + +In this implementation, we use ``Poly`` to represent a rational function +rather than using ``Expr`` since ``Poly`` is much faster. Since we cannot +represent rational functions directly using ``Poly``, we instead represent +a rational function with 2 ``Poly`` objects - one for its numerator and +the other for its denominator. + +The code is written to match the steps given in the thesis (Pg 82) + +Step 0 : Match the equation - +Find `b_0, b_1` and `b_2`. If `b_2 = 0` or no such functions exist, raise +an error + +Step 1 : Transform the equation to its normal form as explained in the +theory section. + +Step 2 : Initialize an empty set of solutions, ``sol``. + +Step 3 : If `a(x) = 0`, append `\frac{1}/{(x - C1)}` to ``sol``. + +Step 4 : If `a(x)` is a rational non-zero number, append `\pm \sqrt{a}` +to ``sol``. + +Step 5 : Find the poles and their multiplicities of `a(x)`. Let +the number of poles be `n`. Also find the valuation of `a(x)` at +`\infty` using ``val_at_inf``. + +NOTE: Although the algorithm considers `\infty` as a pole, it is +not mentioned if it a part of the set of finite poles. `\infty` +is NOT a part of the set of finite poles. If a pole exists at +`\infty`, we use its multiplicity to find the laurent series of +`a(x)` about `\infty`. + +Step 6 : Find `n` c-vectors (one for each pole) and 1 d-vector using +``construct_c`` and ``construct_d``. Now, determine all the ``2**(n + 1)`` +combinations of choosing between 2 choices for each of the `n` c-vectors +and 1 d-vector. + +NOTE: The equation for `d_{-1}` in Case 4 (Pg 80) has a printinig +mistake. The term `- d_N` must be replaced with `-N d_N`. The same +has been explained in the code as well. + +For each of these above combinations, do + +Step 8 : Compute `m` in ``compute_m_ybar``. `m` is the degree bound of +the polynomial solution we must find for the auxiliary equation. + +Step 9 : In ``compute_m_ybar``, compute ybar as well where ``ybar`` is +one part of y(x) - + +.. math:: \overline{y}(x) = \sum_{i=1}^{n} \sum_{j=1}^{r_i} \frac{c_{ij}}{(x - x_i)^j} + \sum_{i=0}^{N} d_i x^i + +Step 10 : If `m` is a non-negative integer - + +Step 11: Find a polynomial solution of degree `m` for the auxiliary equation. + +There are 2 cases possible - + + a. `m` is a non-negative integer: We can solve for the coefficients + in `p(x)` using Undetermined Coefficients. + + b. `m` is not a non-negative integer: In this case, we cannot find + a polynomial solution to the auxiliary equation, and hence, we ignore + this value of `m`. + +Step 12 : For each `p(x)` that exists, append `ybar + \frac{p'(x)}{p(x)}` +to ``sol``. + +Step 13 : For each solution in ``sol``, apply an inverse transformation, +so that the solutions of the original equation are found using the +solutions of the equation in its normal form. +""" + + +from itertools import product +from sympy.core import S +from sympy.core.add import Add +from sympy.core.numbers import oo, Float +from sympy.core.function import count_ops +from sympy.core.relational import Eq +from sympy.core.symbol import symbols, Symbol, Dummy +from sympy.functions import sqrt, exp +from sympy.functions.elementary.complexes import sign +from sympy.integrals.integrals import Integral +from sympy.polys.domains import ZZ +from sympy.polys.polytools import Poly +from sympy.polys.polyroots import roots +from sympy.solvers.solveset import linsolve + + +def riccati_normal(w, x, b1, b2): + """ + Given a solution `w(x)` to the equation + + .. math:: w'(x) = b_0(x) + b_1(x)*w(x) + b_2(x)*w(x)^2 + + and rational function coefficients `b_1(x)` and + `b_2(x)`, this function transforms the solution to + give a solution `y(x)` for its corresponding normal + Riccati ODE + + .. math:: y'(x) + y(x)^2 = a(x) + + using the transformation + + .. math:: y(x) = -b_2(x)*w(x) - b'_2(x)/(2*b_2(x)) - b_1(x)/2 + """ + return -b2*w - b2.diff(x)/(2*b2) - b1/2 + + +def riccati_inverse_normal(y, x, b1, b2, bp=None): + """ + Inverse transforming the solution to the normal + Riccati ODE to get the solution to the Riccati ODE. + """ + # bp is the expression which is independent of the solution + # and hence, it need not be computed again + if bp is None: + bp = -b2.diff(x)/(2*b2**2) - b1/(2*b2) + # w(x) = -y(x)/b2(x) - b2'(x)/(2*b2(x)^2) - b1(x)/(2*b2(x)) + return -y/b2 + bp + + +def riccati_reduced(eq, f, x): + """ + Convert a Riccati ODE into its corresponding + normal Riccati ODE. + """ + match, funcs = match_riccati(eq, f, x) + # If equation is not a Riccati ODE, exit + if not match: + return False + # Using the rational functions, find the expression for a(x) + b0, b1, b2 = funcs + a = -b0*b2 + b1**2/4 - b1.diff(x)/2 + 3*b2.diff(x)**2/(4*b2**2) + b1*b2.diff(x)/(2*b2) - \ + b2.diff(x, 2)/(2*b2) + # Normal form of Riccati ODE is f'(x) + f(x)^2 = a(x) + return f(x).diff(x) + f(x)**2 - a + +def linsolve_dict(eq, syms): + """ + Get the output of linsolve as a dict + """ + # Convert tuple type return value of linsolve + # to a dictionary for ease of use + sol = linsolve(eq, syms) + if not sol: + return {} + return dict(zip(syms, list(sol)[0])) + + +def match_riccati(eq, f, x): + """ + A function that matches and returns the coefficients + if an equation is a Riccati ODE + + Parameters + ========== + + eq: Equation to be matched + f: Dependent variable + x: Independent variable + + Returns + ======= + + match: True if equation is a Riccati ODE, False otherwise + funcs: [b0, b1, b2] if match is True, [] otherwise. Here, + b0, b1 and b2 are rational functions which match the equation. + """ + # Group terms based on f(x) + if isinstance(eq, Eq): + eq = eq.lhs - eq.rhs + eq = eq.expand().collect(f(x)) + cf = eq.coeff(f(x).diff(x)) + + # There must be an f(x).diff(x) term. + # eq must be an Add object since we are using the expanded + # equation and it must have atleast 2 terms (b2 != 0) + if cf != 0 and isinstance(eq, Add): + + # Divide all coefficients by the coefficient of f(x).diff(x) + # and add the terms again to get the same equation + eq = Add(*((x/cf).cancel() for x in eq.args)).collect(f(x)) + + # Match the equation with the pattern + b1 = -eq.coeff(f(x)) + b2 = -eq.coeff(f(x)**2) + b0 = (f(x).diff(x) - b1*f(x) - b2*f(x)**2 - eq).expand() + funcs = [b0, b1, b2] + + # Check if coefficients are not symbols and floats + if any(len(x.atoms(Symbol)) > 1 or len(x.atoms(Float)) for x in funcs): + return False, [] + + # If b_0(x) contains f(x), it is not a Riccati ODE + if len(b0.atoms(f)) or not all((b2 != 0, b0.is_rational_function(x), + b1.is_rational_function(x), b2.is_rational_function(x))): + return False, [] + return True, funcs + return False, [] + + +def val_at_inf(num, den, x): + # Valuation of a rational function at oo = deg(denom) - deg(numer) + return den.degree(x) - num.degree(x) + + +def check_necessary_conds(val_inf, muls): + """ + The necessary conditions for a rational solution + to exist are as follows - + + i) Every pole of a(x) must be either a simple pole + or a multiple pole of even order. + + ii) The valuation of a(x) at infinity must be even + or be greater than or equal to 2. + + Here, a simple pole is a pole with multiplicity 1 + and a multiple pole is a pole with multiplicity + greater than 1. + """ + return (val_inf >= 2 or (val_inf <= 0 and val_inf%2 == 0)) and \ + all(mul == 1 or (mul%2 == 0 and mul >= 2) for mul in muls) + + +def inverse_transform_poly(num, den, x): + """ + A function to make the substitution + x -> 1/x in a rational function that + is represented using Poly objects for + numerator and denominator. + """ + # Declare for reuse + one = Poly(1, x) + xpoly = Poly(x, x) + + # Check if degree of numerator is same as denominator + pwr = val_at_inf(num, den, x) + if pwr >= 0: + # Denominator has greater degree. Substituting x with + # 1/x would make the extra power go to the numerator + if num.expr != 0: + num = num.transform(one, xpoly) * x**pwr + den = den.transform(one, xpoly) + else: + # Numerator has greater degree. Substituting x with + # 1/x would make the extra power go to the denominator + num = num.transform(one, xpoly) + den = den.transform(one, xpoly) * x**(-pwr) + return num.cancel(den, include=True) + + +def limit_at_inf(num, den, x): + """ + Find the limit of a rational function + at oo + """ + # pwr = degree(num) - degree(den) + pwr = -val_at_inf(num, den, x) + # Numerator has a greater degree than denominator + # Limit at infinity would depend on the sign of the + # leading coefficients of numerator and denominator + if pwr > 0: + return oo*sign(num.LC()/den.LC()) + # Degree of numerator is equal to that of denominator + # Limit at infinity is just the ratio of leading coeffs + elif pwr == 0: + return num.LC()/den.LC() + # Degree of numerator is less than that of denominator + # Limit at infinity is just 0 + else: + return 0 + + +def construct_c_case_1(num, den, x, pole): + # Find the coefficient of 1/(x - pole)**2 in the + # Laurent series expansion of a(x) about pole. + num1, den1 = (num*Poly((x - pole)**2, x, extension=True)).cancel(den, include=True) + r = (num1.subs(x, pole))/(den1.subs(x, pole)) + + # If multiplicity is 2, the coefficient to be added + # in the c-vector is c = (1 +- sqrt(1 + 4*r))/2 + if r != -S(1)/4: + return [[(1 + sqrt(1 + 4*r))/2], [(1 - sqrt(1 + 4*r))/2]] + return [[S.Half]] + + +def construct_c_case_2(num, den, x, pole, mul): + # Generate the coefficients using the recurrence + # relation mentioned in (5.14) in the thesis (Pg 80) + + # r_i = mul/2 + ri = mul//2 + + # Find the Laurent series coefficients about the pole + ser = rational_laurent_series(num, den, x, pole, mul, 6) + + # Start with an empty memo to store the coefficients + # This is for the plus case + cplus = [0 for i in range(ri)] + + # Base Case + cplus[ri-1] = sqrt(ser[2*ri]) + + # Iterate backwards to find all coefficients + s = ri - 1 + sm = 0 + for s in range(ri-1, 0, -1): + sm = 0 + for j in range(s+1, ri): + sm += cplus[j-1]*cplus[ri+s-j-1] + if s!= 1: + cplus[s-1] = (ser[ri+s] - sm)/(2*cplus[ri-1]) + + # Memo for the minus case + cminus = [-x for x in cplus] + + # Find the 0th coefficient in the recurrence + cplus[0] = (ser[ri+s] - sm - ri*cplus[ri-1])/(2*cplus[ri-1]) + cminus[0] = (ser[ri+s] - sm - ri*cminus[ri-1])/(2*cminus[ri-1]) + + # Add both the plus and minus cases' coefficients + if cplus != cminus: + return [cplus, cminus] + return cplus + + +def construct_c_case_3(): + # If multiplicity is 1, the coefficient to be added + # in the c-vector is 1 (no choice) + return [[1]] + + +def construct_c(num, den, x, poles, muls): + """ + Helper function to calculate the coefficients + in the c-vector for each pole. + """ + c = [] + for pole, mul in zip(poles, muls): + c.append([]) + + # Case 3 + if mul == 1: + # Add the coefficients from Case 3 + c[-1].extend(construct_c_case_3()) + + # Case 1 + elif mul == 2: + # Add the coefficients from Case 1 + c[-1].extend(construct_c_case_1(num, den, x, pole)) + + # Case 2 + else: + # Add the coefficients from Case 2 + c[-1].extend(construct_c_case_2(num, den, x, pole, mul)) + + return c + + +def construct_d_case_4(ser, N): + # Initialize an empty vector + dplus = [0 for i in range(N+2)] + # d_N = sqrt(a_{2*N}) + dplus[N] = sqrt(ser[2*N]) + + # Use the recurrence relations to find + # the value of d_s + for s in range(N-1, -2, -1): + sm = 0 + for j in range(s+1, N): + sm += dplus[j]*dplus[N+s-j] + if s != -1: + dplus[s] = (ser[N+s] - sm)/(2*dplus[N]) + + # Coefficients for the case of d_N = -sqrt(a_{2*N}) + dminus = [-x for x in dplus] + + # The third equation in Eq 5.15 of the thesis is WRONG! + # d_N must be replaced with N*d_N in that equation. + dplus[-1] = (ser[N+s] - N*dplus[N] - sm)/(2*dplus[N]) + dminus[-1] = (ser[N+s] - N*dminus[N] - sm)/(2*dminus[N]) + + if dplus != dminus: + return [dplus, dminus] + return dplus + + +def construct_d_case_5(ser): + # List to store coefficients for plus case + dplus = [0, 0] + + # d_0 = sqrt(a_0) + dplus[0] = sqrt(ser[0]) + + # d_(-1) = a_(-1)/(2*d_0) + dplus[-1] = ser[-1]/(2*dplus[0]) + + # Coefficients for the minus case are just the negative + # of the coefficients for the positive case. + dminus = [-x for x in dplus] + + if dplus != dminus: + return [dplus, dminus] + return dplus + + +def construct_d_case_6(num, den, x): + # s_oo = lim x->0 1/x**2 * a(1/x) which is equivalent to + # s_oo = lim x->oo x**2 * a(x) + s_inf = limit_at_inf(Poly(x**2, x)*num, den, x) + + # d_(-1) = (1 +- sqrt(1 + 4*s_oo))/2 + if s_inf != -S(1)/4: + return [[(1 + sqrt(1 + 4*s_inf))/2], [(1 - sqrt(1 + 4*s_inf))/2]] + return [[S.Half]] + + +def construct_d(num, den, x, val_inf): + """ + Helper function to calculate the coefficients + in the d-vector based on the valuation of the + function at oo. + """ + N = -val_inf//2 + # Multiplicity of oo as a pole + mul = -val_inf if val_inf < 0 else 0 + ser = rational_laurent_series(num, den, x, oo, mul, 1) + + # Case 4 + if val_inf < 0: + d = construct_d_case_4(ser, N) + + # Case 5 + elif val_inf == 0: + d = construct_d_case_5(ser) + + # Case 6 + else: + d = construct_d_case_6(num, den, x) + + return d + + +def rational_laurent_series(num, den, x, r, m, n): + r""" + The function computes the Laurent series coefficients + of a rational function. + + Parameters + ========== + + num: A Poly object that is the numerator of `f(x)`. + den: A Poly object that is the denominator of `f(x)`. + x: The variable of expansion of the series. + r: The point of expansion of the series. + m: Multiplicity of r if r is a pole of `f(x)`. Should + be zero otherwise. + n: Order of the term upto which the series is expanded. + + Returns + ======= + + series: A dictionary that has power of the term as key + and coefficient of that term as value. + + Below is a basic outline of how the Laurent series of a + rational function `f(x)` about `x_0` is being calculated - + + 1. Substitute `x + x_0` in place of `x`. If `x_0` + is a pole of `f(x)`, multiply the expression by `x^m` + where `m` is the multiplicity of `x_0`. Denote the + the resulting expression as g(x). We do this substitution + so that we can now find the Laurent series of g(x) about + `x = 0`. + + 2. We can then assume that the Laurent series of `g(x)` + takes the following form - + + .. math:: g(x) = \frac{num(x)}{den(x)} = \sum_{m = 0}^{\infty} a_m x^m + + where `a_m` denotes the Laurent series coefficients. + + 3. Multiply the denominator to the RHS of the equation + and form a recurrence relation for the coefficients `a_m`. + """ + one = Poly(1, x, extension=True) + + if r == oo: + # Series at x = oo is equal to first transforming + # the function from x -> 1/x and finding the + # series at x = 0 + num, den = inverse_transform_poly(num, den, x) + r = S(0) + + if r: + # For an expansion about a non-zero point, a + # transformation from x -> x + r must be made + num = num.transform(Poly(x + r, x, extension=True), one) + den = den.transform(Poly(x + r, x, extension=True), one) + + # Remove the pole from the denominator if the series + # expansion is about one of the poles + num, den = (num*x**m).cancel(den, include=True) + + # Equate coefficients for the first terms (base case) + maxdegree = 1 + max(num.degree(), den.degree()) + syms = symbols(f'a:{maxdegree}', cls=Dummy) + diff = num - den * Poly(syms[::-1], x) + coeff_diffs = diff.all_coeffs()[::-1][:maxdegree] + (coeffs, ) = linsolve(coeff_diffs, syms) + + # Use the recursion relation for the rest + recursion = den.all_coeffs()[::-1] + div, rec_rhs = recursion[0], recursion[1:] + series = list(coeffs) + while len(series) < n: + next_coeff = Add(*(c*series[-1-n] for n, c in enumerate(rec_rhs))) / div + series.append(-next_coeff) + series = {m - i: val for i, val in enumerate(series)} + return series + +def compute_m_ybar(x, poles, choice, N): + """ + Helper function to calculate - + + 1. m - The degree bound for the polynomial + solution that must be found for the auxiliary + differential equation. + + 2. ybar - Part of the solution which can be + computed using the poles, c and d vectors. + """ + ybar = 0 + m = Poly(choice[-1][-1], x, extension=True) + + # Calculate the first (nested) summation for ybar + # as given in Step 9 of the Thesis (Pg 82) + dybar = [] + for i, polei in enumerate(poles): + for j, cij in enumerate(choice[i]): + dybar.append(cij/(x - polei)**(j + 1)) + m -=Poly(choice[i][0], x, extension=True) # can't accumulate Poly and use with Add + ybar += Add(*dybar) + + # Calculate the second summation for ybar + for i in range(N+1): + ybar += choice[-1][i]*x**i + return (m.expr, ybar) + + +def solve_aux_eq(numa, dena, numy, deny, x, m): + """ + Helper function to find a polynomial solution + of degree m for the auxiliary differential + equation. + """ + # Assume that the solution is of the type + # p(x) = C_0 + C_1*x + ... + C_{m-1}*x**(m-1) + x**m + psyms = symbols(f'C0:{m}', cls=Dummy) + K = ZZ[psyms] + psol = Poly(K.gens, x, domain=K) + Poly(x**m, x, domain=K) + + # Eq (5.16) in Thesis - Pg 81 + auxeq = (dena*(numy.diff(x)*deny - numy*deny.diff(x) + numy**2) - numa*deny**2)*psol + if m >= 1: + px = psol.diff(x) + auxeq += px*(2*numy*deny*dena) + if m >= 2: + auxeq += px.diff(x)*(deny**2*dena) + if m != 0: + # m is a non-zero integer. Find the constant terms using undetermined coefficients + return psol, linsolve_dict(auxeq.all_coeffs(), psyms), True + else: + # m == 0 . Check if 1 (x**0) is a solution to the auxiliary equation + return S.One, auxeq, auxeq == 0 + + +def remove_redundant_sols(sol1, sol2, x): + """ + Helper function to remove redundant + solutions to the differential equation. + """ + # If y1 and y2 are redundant solutions, there is + # some value of the arbitrary constant for which + # they will be equal + + syms1 = sol1.atoms(Symbol, Dummy) + syms2 = sol2.atoms(Symbol, Dummy) + num1, den1 = [Poly(e, x, extension=True) for e in sol1.together().as_numer_denom()] + num2, den2 = [Poly(e, x, extension=True) for e in sol2.together().as_numer_denom()] + # Cross multiply + e = num1*den2 - den1*num2 + # Check if there are any constants + syms = list(e.atoms(Symbol, Dummy)) + if len(syms): + # Find values of constants for which solutions are equal + redn = linsolve(e.all_coeffs(), syms) + if len(redn): + # Return the general solution over a particular solution + if len(syms1) > len(syms2): + return sol2 + # If both have constants, return the lesser complex solution + elif len(syms1) == len(syms2): + return sol1 if count_ops(syms1) >= count_ops(syms2) else sol2 + else: + return sol1 + + +def get_gen_sol_from_part_sol(part_sols, a, x): + """" + Helper function which computes the general + solution for a Riccati ODE from its particular + solutions. + + There are 3 cases to find the general solution + from the particular solutions for a Riccati ODE + depending on the number of particular solution(s) + we have - 1, 2 or 3. + + For more information, see Section 6 of + "Methods of Solution of the Riccati Differential Equation" + by D. R. Haaheim and F. M. Stein + """ + + # If no particular solutions are found, a general + # solution cannot be found + if len(part_sols) == 0: + return [] + + # In case of a single particular solution, the general + # solution can be found by using the substitution + # y = y1 + 1/z and solving a Bernoulli ODE to find z. + elif len(part_sols) == 1: + y1 = part_sols[0] + i = exp(Integral(2*y1, x)) + z = i * Integral(a/i, x) + z = z.doit() + if a == 0 or z == 0: + return y1 + return y1 + 1/z + + # In case of 2 particular solutions, the general solution + # can be found by solving a separable equation. This is + # the most common case, i.e. most Riccati ODEs have 2 + # rational particular solutions. + elif len(part_sols) == 2: + y1, y2 = part_sols + # One of them already has a constant + if len(y1.atoms(Dummy)) + len(y2.atoms(Dummy)) > 0: + u = exp(Integral(y2 - y1, x)).doit() + # Introduce a constant + else: + C1 = Dummy('C1') + u = C1*exp(Integral(y2 - y1, x)).doit() + if u == 1: + return y2 + return (y2*u - y1)/(u - 1) + + # In case of 3 particular solutions, a closed form + # of the general solution can be obtained directly + else: + y1, y2, y3 = part_sols[:3] + C1 = Dummy('C1') + return (C1 + 1)*y2*(y1 - y3)/(C1*y1 + y2 - (C1 + 1)*y3) + + +def solve_riccati(fx, x, b0, b1, b2, gensol=False): + """ + The main function that gives particular/general + solutions to Riccati ODEs that have atleast 1 + rational particular solution. + """ + # Step 1 : Convert to Normal Form + a = -b0*b2 + b1**2/4 - b1.diff(x)/2 + 3*b2.diff(x)**2/(4*b2**2) + b1*b2.diff(x)/(2*b2) - \ + b2.diff(x, 2)/(2*b2) + a_t = a.together() + num, den = [Poly(e, x, extension=True) for e in a_t.as_numer_denom()] + num, den = num.cancel(den, include=True) + + # Step 2 + presol = [] + + # Step 3 : a(x) is 0 + if num == 0: + presol.append(1/(x + Dummy('C1'))) + + # Step 4 : a(x) is a non-zero constant + elif x not in num.free_symbols.union(den.free_symbols): + presol.extend([sqrt(a), -sqrt(a)]) + + # Step 5 : Find poles and valuation at infinity + poles = roots(den, x) + poles, muls = list(poles.keys()), list(poles.values()) + val_inf = val_at_inf(num, den, x) + + if len(poles): + # Check necessary conditions (outlined in the module docstring) + if not check_necessary_conds(val_inf, muls): + raise ValueError("Rational Solution doesn't exist") + + # Step 6 + # Construct c-vectors for each singular point + c = construct_c(num, den, x, poles, muls) + + # Construct d vectors for each singular point + d = construct_d(num, den, x, val_inf) + + # Step 7 : Iterate over all possible combinations and return solutions + # For each possible combination, generate an array of 0's and 1's + # where 0 means pick 1st choice and 1 means pick the second choice. + + # NOTE: We could exit from the loop if we find 3 particular solutions, + # but it is not implemented here as - + # a. Finding 3 particular solutions is very rare. Most of the time, + # only 2 particular solutions are found. + # b. In case we exit after finding 3 particular solutions, it might + # happen that 1 or 2 of them are redundant solutions. So, instead of + # spending some more time in computing the particular solutions, + # we will end up computing the general solution from a single + # particular solution which is usually slower than computing the + # general solution from 2 or 3 particular solutions. + c.append(d) + choices = product(*c) + for choice in choices: + m, ybar = compute_m_ybar(x, poles, choice, -val_inf//2) + numy, deny = [Poly(e, x, extension=True) for e in ybar.together().as_numer_denom()] + # Step 10 : Check if a valid solution exists. If yes, also check + # if m is a non-negative integer + if m.is_nonnegative == True and m.is_integer == True: + + # Step 11 : Find polynomial solutions of degree m for the auxiliary equation + psol, coeffs, exists = solve_aux_eq(num, den, numy, deny, x, m) + + # Step 12 : If valid polynomial solution exists, append solution. + if exists: + # m == 0 case + if psol == 1 and coeffs == 0: + # p(x) = 1, so p'(x)/p(x) term need not be added + presol.append(ybar) + # m is a positive integer and there are valid coefficients + elif len(coeffs): + # Substitute the valid coefficients to get p(x) + psol = psol.xreplace(coeffs) + # y(x) = ybar(x) + p'(x)/p(x) + presol.append(ybar + psol.diff(x)/psol) + + # Remove redundant solutions from the list of existing solutions + remove = set() + for i in range(len(presol)): + for j in range(i+1, len(presol)): + rem = remove_redundant_sols(presol[i], presol[j], x) + if rem is not None: + remove.add(rem) + sols = [x for x in presol if x not in remove] + + # Step 15 : Inverse transform the solutions of the equation in normal form + bp = -b2.diff(x)/(2*b2**2) - b1/(2*b2) + + # If general solution is required, compute it from the particular solutions + if gensol: + sols = [get_gen_sol_from_part_sol(sols, a, x)] + + # Inverse transform the particular solutions + presol = [Eq(fx, riccati_inverse_normal(y, x, b1, b2, bp).cancel(extension=True)) for y in sols] + return presol diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/single.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/single.py new file mode 100644 index 0000000000000000000000000000000000000000..c4829acf41293c2f6f20af3e9c45d37457802102 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/single.py @@ -0,0 +1,2977 @@ +# +# This is the module for ODE solver classes for single ODEs. +# + +from __future__ import annotations +from typing import ClassVar, Iterator + +from .riccati import match_riccati, solve_riccati +from sympy.core import Add, S, Pow, Rational +from sympy.core.cache import cached_property +from sympy.core.exprtools import factor_terms +from sympy.core.expr import Expr +from sympy.core.function import AppliedUndef, Derivative, diff, Function, expand, Subs, _mexpand +from sympy.core.numbers import zoo +from sympy.core.relational import Equality, Eq +from sympy.core.symbol import Symbol, Dummy, Wild +from sympy.core.mul import Mul +from sympy.functions import exp, tan, log, sqrt, besselj, bessely, cbrt, airyai, airybi +from sympy.integrals import Integral +from sympy.polys import Poly +from sympy.polys.polytools import cancel, factor, degree +from sympy.simplify import collect, simplify, separatevars, logcombine, posify # type: ignore +from sympy.simplify.radsimp import fraction +from sympy.utilities import numbered_symbols +from sympy.solvers.solvers import solve +from sympy.solvers.deutils import ode_order, _preprocess +from sympy.polys.matrices.linsolve import _lin_eq2dict +from sympy.polys.solvers import PolyNonlinearError +from .hypergeometric import equivalence_hypergeometric, match_2nd_2F1_hypergeometric, \ + get_sol_2F1_hypergeometric, match_2nd_hypergeometric +from .nonhomogeneous import _get_euler_characteristic_eq_sols, _get_const_characteristic_eq_sols, \ + _solve_undetermined_coefficients, _solve_variation_of_parameters, _test_term, _undetermined_coefficients_match, \ + _get_simplified_sol +from .lie_group import _ode_lie_group + + +class ODEMatchError(NotImplementedError): + """Raised if a SingleODESolver is asked to solve an ODE it does not match""" + pass + + +class SingleODEProblem: + """Represents an ordinary differential equation (ODE) + + This class is used internally in the by dsolve and related + functions/classes so that properties of an ODE can be computed + efficiently. + + Examples + ======== + + This class is used internally by dsolve. To instantiate an instance + directly first define an ODE problem: + + >>> from sympy import Function, Symbol + >>> x = Symbol('x') + >>> f = Function('f') + >>> eq = f(x).diff(x, 2) + + Now you can create a SingleODEProblem instance and query its properties: + + >>> from sympy.solvers.ode.single import SingleODEProblem + >>> problem = SingleODEProblem(f(x).diff(x), f(x), x) + >>> problem.eq + Derivative(f(x), x) + >>> problem.func + f(x) + >>> problem.sym + x + """ + + # Instance attributes: + eq: Expr + func: AppliedUndef + sym: Symbol + _order: int + _eq_expanded: Expr + _eq_preprocessed: Expr + _eq_high_order_free = None + + def __init__(self, eq, func, sym, prep=True, **kwargs): + assert isinstance(eq, Expr) + assert isinstance(func, AppliedUndef) + assert isinstance(sym, Symbol) + assert isinstance(prep, bool) + self.eq = eq + self.func = func + self.sym = sym + self.prep = prep + self.params = kwargs + + @cached_property + def order(self) -> int: + return ode_order(self.eq, self.func) + + @cached_property + def eq_preprocessed(self) -> Expr: + return self._get_eq_preprocessed() + + @cached_property + def eq_high_order_free(self) -> Expr: + a = Wild('a', exclude=[self.func]) + c1 = Wild('c1', exclude=[self.sym]) + # Precondition to try remove f(x) from highest order derivative + reduced_eq = None + if self.eq.is_Add: + deriv_coef = self.eq.coeff(self.func.diff(self.sym, self.order)) + if deriv_coef not in (1, 0): + r = deriv_coef.match(a*self.func**c1) + if r and r[c1]: + den = self.func**r[c1] + reduced_eq = Add(*[arg/den for arg in self.eq.args]) + if reduced_eq is None: + reduced_eq = expand(self.eq) + return reduced_eq + + @cached_property + def eq_expanded(self) -> Expr: + return expand(self.eq_preprocessed) + + def _get_eq_preprocessed(self) -> Expr: + if self.prep: + process_eq, process_func = _preprocess(self.eq, self.func) + if process_func != self.func: + raise ValueError + else: + process_eq = self.eq + return process_eq + + def get_numbered_constants(self, num=1, start=1, prefix='C') -> list[Symbol]: + """ + Returns a list of constants that do not occur + in eq already. + """ + ncs = self.iter_numbered_constants(start, prefix) + Cs = [next(ncs) for i in range(num)] + return Cs + + def iter_numbered_constants(self, start=1, prefix='C') -> Iterator[Symbol]: + """ + Returns an iterator of constants that do not occur + in eq already. + """ + atom_set = self.eq.free_symbols + func_set = self.eq.atoms(Function) + if func_set: + atom_set |= {Symbol(str(f.func)) for f in func_set} + return numbered_symbols(start=start, prefix=prefix, exclude=atom_set) + + @cached_property + def is_autonomous(self): + u = Dummy('u') + x = self.sym + syms = self.eq.subs(self.func, u).free_symbols + return x not in syms + + def get_linear_coefficients(self, eq, func, order): + r""" + Matches a differential equation to the linear form: + + .. math:: a_n(x) y^{(n)} + \cdots + a_1(x)y' + a_0(x) y + B(x) = 0 + + Returns a dict of order:coeff terms, where order is the order of the + derivative on each term, and coeff is the coefficient of that derivative. + The key ``-1`` holds the function `B(x)`. Returns ``None`` if the ODE is + not linear. This function assumes that ``func`` has already been checked + to be good. + + Examples + ======== + + >>> from sympy import Function, cos, sin + >>> from sympy.abc import x + >>> from sympy.solvers.ode.single import SingleODEProblem + >>> f = Function('f') + >>> eq = f(x).diff(x, 3) + 2*f(x).diff(x) + \ + ... x*f(x).diff(x, 2) + cos(x)*f(x).diff(x) + x - f(x) - \ + ... sin(x) + >>> obj = SingleODEProblem(eq, f(x), x) + >>> obj.get_linear_coefficients(eq, f(x), 3) + {-1: x - sin(x), 0: -1, 1: cos(x) + 2, 2: x, 3: 1} + >>> eq = f(x).diff(x, 3) + 2*f(x).diff(x) + \ + ... x*f(x).diff(x, 2) + cos(x)*f(x).diff(x) + x - f(x) - \ + ... sin(f(x)) + >>> obj = SingleODEProblem(eq, f(x), x) + >>> obj.get_linear_coefficients(eq, f(x), 3) == None + True + + """ + f = func.func + x = func.args[0] + symset = {Derivative(f(x), x, i) for i in range(order+1)} + try: + rhs, lhs_terms = _lin_eq2dict(eq, symset) + except PolyNonlinearError: + return None + + if rhs.has(func) or any(c.has(func) for c in lhs_terms.values()): + return None + terms = {i: lhs_terms.get(f(x).diff(x, i), S.Zero) for i in range(order+1)} + terms[-1] = rhs + return terms + + # TODO: Add methods that can be used by many ODE solvers: + # order + # is_linear() + # get_linear_coefficients() + # eq_prepared (the ODE in prepared form) + + +class SingleODESolver: + """ + Base class for Single ODE solvers. + + Subclasses should implement the _matches and _get_general_solution + methods. This class is not intended to be instantiated directly but its + subclasses are as part of dsolve. + + Examples + ======== + + You can use a subclass of SingleODEProblem to solve a particular type of + ODE. We first define a particular ODE problem: + + >>> from sympy import Function, Symbol + >>> x = Symbol('x') + >>> f = Function('f') + >>> eq = f(x).diff(x, 2) + + Now we solve this problem using the NthAlgebraic solver which is a + subclass of SingleODESolver: + + >>> from sympy.solvers.ode.single import NthAlgebraic, SingleODEProblem + >>> problem = SingleODEProblem(eq, f(x), x) + >>> solver = NthAlgebraic(problem) + >>> solver.get_general_solution() + [Eq(f(x), _C*x + _C)] + + The normal way to solve an ODE is to use dsolve (which would use + NthAlgebraic and other solvers internally). When using dsolve a number of + other things are done such as evaluating integrals, simplifying the + solution and renumbering the constants: + + >>> from sympy import dsolve + >>> dsolve(eq, hint='nth_algebraic') + Eq(f(x), C1 + C2*x) + """ + + # Subclasses should store the hint name (the argument to dsolve) in this + # attribute + hint: ClassVar[str] + + # Subclasses should define this to indicate if they support an _Integral + # hint. + has_integral: ClassVar[bool] + + # The ODE to be solved + ode_problem: SingleODEProblem + + # Cache whether or not the equation has matched the method + _matched: bool | None = None + + # Subclasses should store in this attribute the list of order(s) of ODE + # that subclass can solve or leave it to None if not specific to any order + order: list | None = None + + def __init__(self, ode_problem): + self.ode_problem = ode_problem + + def matches(self) -> bool: + if self.order is not None and self.ode_problem.order not in self.order: + self._matched = False + return self._matched + + if self._matched is None: + self._matched = self._matches() + return self._matched + + def get_general_solution(self, *, simplify: bool = True) -> list[Equality]: + if not self.matches(): + msg = "%s solver cannot solve:\n%s" + raise ODEMatchError(msg % (self.hint, self.ode_problem.eq)) + return self._get_general_solution(simplify_flag=simplify) + + def _matches(self) -> bool: + msg = "Subclasses of SingleODESolver should implement matches." + raise NotImplementedError(msg) + + def _get_general_solution(self, *, simplify_flag: bool = True) -> list[Equality]: + msg = "Subclasses of SingleODESolver should implement get_general_solution." + raise NotImplementedError(msg) + + +class SinglePatternODESolver(SingleODESolver): + '''Superclass for ODE solvers based on pattern matching''' + + def wilds(self): + prob = self.ode_problem + f = prob.func.func + x = prob.sym + order = prob.order + return self._wilds(f, x, order) + + def wilds_match(self): + match = self._wilds_match + return [match.get(w, S.Zero) for w in self.wilds()] + + def _matches(self): + eq = self.ode_problem.eq_expanded + f = self.ode_problem.func.func + x = self.ode_problem.sym + order = self.ode_problem.order + df = f(x).diff(x, order) + + if order not in [1, 2]: + return False + + pattern = self._equation(f(x), x, order) + + if not pattern.coeff(df).has(Wild): + eq = expand(eq / eq.coeff(df)) + eq = eq.collect([f(x).diff(x), f(x)], func = cancel) + + self._wilds_match = match = eq.match(pattern) + if match is not None: + return self._verify(f(x)) + return False + + def _verify(self, fx) -> bool: + return True + + def _wilds(self, f, x, order): + msg = "Subclasses of SingleODESolver should implement _wilds" + raise NotImplementedError(msg) + + def _equation(self, fx, x, order): + msg = "Subclasses of SingleODESolver should implement _equation" + raise NotImplementedError(msg) + + +class NthAlgebraic(SingleODESolver): + r""" + Solves an `n`\th order ordinary differential equation using algebra and + integrals. + + There is no general form for the kind of equation that this can solve. The + the equation is solved algebraically treating differentiation as an + invertible algebraic function. + + Examples + ======== + + >>> from sympy import Function, dsolve, Eq + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = Eq(f(x) * (f(x).diff(x)**2 - 1), 0) + >>> dsolve(eq, f(x), hint='nth_algebraic') + [Eq(f(x), 0), Eq(f(x), C1 - x), Eq(f(x), C1 + x)] + + Note that this solver can return algebraic solutions that do not have any + integration constants (f(x) = 0 in the above example). + """ + + hint = 'nth_algebraic' + has_integral = True # nth_algebraic_Integral hint + + def _matches(self): + r""" + Matches any differential equation that nth_algebraic can solve. Uses + `sympy.solve` but teaches it how to integrate derivatives. + + This involves calling `sympy.solve` and does most of the work of finding a + solution (apart from evaluating the integrals). + """ + eq = self.ode_problem.eq + func = self.ode_problem.func + var = self.ode_problem.sym + + # Derivative that solve can handle: + diffx = self._get_diffx(var) + + # Replace derivatives wrt the independent variable with diffx + def replace(eq, var): + def expand_diffx(*args): + differand, diffs = args[0], args[1:] + toreplace = differand + for v, n in diffs: + for _ in range(n): + if v == var: + toreplace = diffx(toreplace) + else: + toreplace = Derivative(toreplace, v) + return toreplace + return eq.replace(Derivative, expand_diffx) + + # Restore derivatives in solution afterwards + def unreplace(eq, var): + return eq.replace(diffx, lambda e: Derivative(e, var)) + + subs_eqn = replace(eq, var) + try: + # turn off simplification to protect Integrals that have + # _t instead of fx in them and would otherwise factor + # as t_*Integral(1, x) + solns = solve(subs_eqn, func, simplify=False) + except NotImplementedError: + solns = [] + + solns = [simplify(unreplace(soln, var)) for soln in solns] + solns = [Equality(func, soln) for soln in solns] + + self.solutions = solns + return len(solns) != 0 + + def _get_general_solution(self, *, simplify_flag: bool = True): + return self.solutions + + # This needs to produce an invertible function but the inverse depends + # which variable we are integrating with respect to. Since the class can + # be stored in cached results we need to ensure that we always get the + # same class back for each particular integration variable so we store these + # classes in a global dict: + _diffx_stored: dict[Symbol, type[Function]] = {} + + @staticmethod + def _get_diffx(var): + diffcls = NthAlgebraic._diffx_stored.get(var, None) + + if diffcls is None: + # A class that behaves like Derivative wrt var but is "invertible". + class diffx(Function): + def inverse(self): + # don't use integrate here because fx has been replaced by _t + # in the equation; integrals will not be correct while solve + # is at work. + return lambda expr: Integral(expr, var) + Dummy('C') + + diffcls = NthAlgebraic._diffx_stored.setdefault(var, diffx) + + return diffcls + + +class FirstExact(SinglePatternODESolver): + r""" + Solves 1st order exact ordinary differential equations. + + A 1st order differential equation is called exact if it is the total + differential of a function. That is, the differential equation + + .. math:: P(x, y) \,\partial{}x + Q(x, y) \,\partial{}y = 0 + + is exact if there is some function `F(x, y)` such that `P(x, y) = + \partial{}F/\partial{}x` and `Q(x, y) = \partial{}F/\partial{}y`. It can + be shown that a necessary and sufficient condition for a first order ODE + to be exact is that `\partial{}P/\partial{}y = \partial{}Q/\partial{}x`. + Then, the solution will be as given below:: + + >>> from sympy import Function, Eq, Integral, symbols, pprint + >>> x, y, t, x0, y0, C1= symbols('x,y,t,x0,y0,C1') + >>> P, Q, F= map(Function, ['P', 'Q', 'F']) + >>> pprint(Eq(Eq(F(x, y), Integral(P(t, y), (t, x0, x)) + + ... Integral(Q(x0, t), (t, y0, y))), C1)) + x y + / / + | | + F(x, y) = | P(t, y) dt + | Q(x0, t) dt = C1 + | | + / / + x0 y0 + + Where the first partials of `P` and `Q` exist and are continuous in a + simply connected region. + + A note: SymPy currently has no way to represent inert substitution on an + expression, so the hint ``1st_exact_Integral`` will return an integral + with `dy`. This is supposed to represent the function that you are + solving for. + + Examples + ======== + + >>> from sympy import Function, dsolve, cos, sin + >>> from sympy.abc import x + >>> f = Function('f') + >>> dsolve(cos(f(x)) - (x*sin(f(x)) - f(x)**2)*f(x).diff(x), + ... f(x), hint='1st_exact') + Eq(x*cos(f(x)) + f(x)**3/3, C1) + + References + ========== + + - https://en.wikipedia.org/wiki/Exact_differential_equation + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 73 + + # indirect doctest + + """ + hint = "1st_exact" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + P = Wild('P', exclude=[f(x).diff(x)]) + Q = Wild('Q', exclude=[f(x).diff(x)]) + return P, Q + + def _equation(self, fx, x, order): + P, Q = self.wilds() + return P + Q*fx.diff(x) + + def _verify(self, fx) -> bool: + P, Q = self.wilds() + x = self.ode_problem.sym + y = Dummy('y') + + m, n = self.wilds_match() + + m = m.subs(fx, y) + n = n.subs(fx, y) + numerator = cancel(m.diff(y) - n.diff(x)) + + if numerator.is_zero: + # Is exact + return True + else: + # The following few conditions try to convert a non-exact + # differential equation into an exact one. + # References: + # 1. Differential equations with applications + # and historical notes - George E. Simmons + # 2. https://math.okstate.edu/people/binegar/2233-S99/2233-l12.pdf + + factor_n = cancel(numerator/n) + factor_m = cancel(-numerator/m) + if y not in factor_n.free_symbols: + # If (dP/dy - dQ/dx) / Q = f(x) + # then exp(integral(f(x))*equation becomes exact + factor = factor_n + integration_variable = x + elif x not in factor_m.free_symbols: + # If (dP/dy - dQ/dx) / -P = f(y) + # then exp(integral(f(y))*equation becomes exact + factor = factor_m + integration_variable = y + else: + # Couldn't convert to exact + return False + + factor = exp(Integral(factor, integration_variable)) + m *= factor + n *= factor + self._wilds_match[P] = m.subs(y, fx) + self._wilds_match[Q] = n.subs(y, fx) + return True + + def _get_general_solution(self, *, simplify_flag: bool = True): + m, n = self.wilds_match() + fx = self.ode_problem.func + x = self.ode_problem.sym + (C1,) = self.ode_problem.get_numbered_constants(num=1) + y = Dummy('y') + + m = m.subs(fx, y) + n = n.subs(fx, y) + + gen_sol = Eq(Subs(Integral(m, x) + + Integral(n - Integral(m, x).diff(y), y), y, fx), C1) + return [gen_sol] + + +class FirstLinear(SinglePatternODESolver): + r""" + Solves 1st order linear differential equations. + + These are differential equations of the form + + .. math:: dy/dx + P(x) y = Q(x)\text{.} + + These kinds of differential equations can be solved in a general way. The + integrating factor `e^{\int P(x) \,dx}` will turn the equation into a + separable equation. The general solution is:: + + >>> from sympy import Function, dsolve, Eq, pprint, diff, sin + >>> from sympy.abc import x + >>> f, P, Q = map(Function, ['f', 'P', 'Q']) + >>> genform = Eq(f(x).diff(x) + P(x)*f(x), Q(x)) + >>> pprint(genform) + d + P(x)*f(x) + --(f(x)) = Q(x) + dx + >>> pprint(dsolve(genform, f(x), hint='1st_linear_Integral')) + / / \ + | | | + | | / | / + | | | | | + | | | P(x) dx | - | P(x) dx + | | | | | + | | / | / + f(x) = |C1 + | Q(x)*e dx|*e + | | | + \ / / + + + Examples + ======== + + >>> f = Function('f') + >>> pprint(dsolve(Eq(x*diff(f(x), x) - f(x), x**2*sin(x)), + ... f(x), '1st_linear')) + f(x) = x*(C1 - cos(x)) + + References + ========== + + - https://en.wikipedia.org/wiki/Linear_differential_equation#First-order_equation_with_variable_coefficients + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 92 + + # indirect doctest + + """ + hint = '1st_linear' + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + P = Wild('P', exclude=[f(x)]) + Q = Wild('Q', exclude=[f(x), f(x).diff(x)]) + return P, Q + + def _equation(self, fx, x, order): + P, Q = self.wilds() + return fx.diff(x) + P*fx - Q + + def _get_general_solution(self, *, simplify_flag: bool = True): + P, Q = self.wilds_match() + fx = self.ode_problem.func + x = self.ode_problem.sym + (C1,) = self.ode_problem.get_numbered_constants(num=1) + gensol = Eq(fx, ((C1 + Integral(Q*exp(Integral(P, x)), x)) + * exp(-Integral(P, x)))) + return [gensol] + + +class AlmostLinear(SinglePatternODESolver): + r""" + Solves an almost-linear differential equation. + + The general form of an almost linear differential equation is + + .. math:: a(x) g'(f(x)) f'(x) + b(x) g(f(x)) + c(x) + + Here `f(x)` is the function to be solved for (the dependent variable). + The substitution `g(f(x)) = u(x)` leads to a linear differential equation + for `u(x)` of the form `a(x) u' + b(x) u + c(x) = 0`. This can be solved + for `u(x)` by the `first_linear` hint and then `f(x)` is found by solving + `g(f(x)) = u(x)`. + + See Also + ======== + :obj:`sympy.solvers.ode.single.FirstLinear` + + Examples + ======== + + >>> from sympy import dsolve, Function, pprint, sin, cos + >>> from sympy.abc import x + >>> f = Function('f') + >>> d = f(x).diff(x) + >>> eq = x*d + x*f(x) + 1 + >>> dsolve(eq, f(x), hint='almost_linear') + Eq(f(x), (C1 - Ei(x))*exp(-x)) + >>> pprint(dsolve(eq, f(x), hint='almost_linear')) + -x + f(x) = (C1 - Ei(x))*e + >>> example = cos(f(x))*f(x).diff(x) + sin(f(x)) + 1 + >>> pprint(example) + d + sin(f(x)) + cos(f(x))*--(f(x)) + 1 + dx + >>> pprint(dsolve(example, f(x), hint='almost_linear')) + / -x \ / -x \ + [f(x) = pi - asin\C1*e - 1/, f(x) = asin\C1*e - 1/] + + + References + ========== + + - Joel Moses, "Symbolic Integration - The Stormy Decade", Communications + of the ACM, Volume 14, Number 8, August 1971, pp. 558 + """ + hint = "almost_linear" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + P = Wild('P', exclude=[f(x).diff(x)]) + Q = Wild('Q', exclude=[f(x).diff(x)]) + return P, Q + + def _equation(self, fx, x, order): + P, Q = self.wilds() + return P*fx.diff(x) + Q + + def _verify(self, fx): + a, b = self.wilds_match() + c, b = b.as_independent(fx) if b.is_Add else (S.Zero, b) + # a, b and c are the function a(x), b(x) and c(x) respectively. + # c(x) is obtained by separating out b as terms with and without fx i.e, l(y) + # The following conditions checks if the given equation is an almost-linear differential equation using the fact that + # a(x)*(l(y))' / l(y)' is independent of l(y) + + if b.diff(fx) != 0 and not simplify(b.diff(fx)/a).has(fx): + self.ly = factor_terms(b).as_independent(fx, as_Add=False)[1] # Gives the term containing fx i.e., l(y) + self.ax = a / self.ly.diff(fx) + self.cx = -c # cx is taken as -c(x) to simplify expression in the solution integral + self.bx = factor_terms(b) / self.ly + return True + + return False + + def _get_general_solution(self, *, simplify_flag: bool = True): + x = self.ode_problem.sym + (C1,) = self.ode_problem.get_numbered_constants(num=1) + gensol = Eq(self.ly, ((C1 + Integral((self.cx/self.ax)*exp(Integral(self.bx/self.ax, x)), x)) + * exp(-Integral(self.bx/self.ax, x)))) + + return [gensol] + + +class Bernoulli(SinglePatternODESolver): + r""" + Solves Bernoulli differential equations. + + These are equations of the form + + .. math:: dy/dx + P(x) y = Q(x) y^n\text{, }n \ne 1`\text{.} + + The substitution `w = 1/y^{1-n}` will transform an equation of this form + into one that is linear (see the docstring of + :obj:`~sympy.solvers.ode.single.FirstLinear`). The general solution is:: + + >>> from sympy import Function, dsolve, Eq, pprint + >>> from sympy.abc import x, n + >>> f, P, Q = map(Function, ['f', 'P', 'Q']) + >>> genform = Eq(f(x).diff(x) + P(x)*f(x), Q(x)*f(x)**n) + >>> pprint(genform) + d n + P(x)*f(x) + --(f(x)) = Q(x)*f (x) + dx + >>> pprint(dsolve(genform, f(x), hint='Bernoulli_Integral'), num_columns=110) + -1 + ----- + n - 1 + // / / \ \ + || | | | | + || | / | / | / | + || | | | | | | | + || | -(n - 1)* | P(x) dx | -(n - 1)* | P(x) dx | (n - 1)* | P(x) dx| + || | | | | | | | + || | / | / | / | + f(x) = ||C1 - n* | Q(x)*e dx + | Q(x)*e dx|*e | + || | | | | + \\ / / / / + + + Note that the equation is separable when `n = 1` (see the docstring of + :obj:`~sympy.solvers.ode.single.Separable`). + + >>> pprint(dsolve(Eq(f(x).diff(x) + P(x)*f(x), Q(x)*f(x)), f(x), + ... hint='separable_Integral')) + f(x) + / + | / + | 1 | + | - dy = C1 + | (-P(x) + Q(x)) dx + | y | + | / + / + + + Examples + ======== + + >>> from sympy import Function, dsolve, Eq, pprint, log + >>> from sympy.abc import x + >>> f = Function('f') + + >>> pprint(dsolve(Eq(x*f(x).diff(x) + f(x), log(x)*f(x)**2), + ... f(x), hint='Bernoulli')) + 1 + f(x) = ----------------- + C1*x + log(x) + 1 + + References + ========== + + - https://en.wikipedia.org/wiki/Bernoulli_differential_equation + + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 95 + + # indirect doctest + + """ + hint = "Bernoulli" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + P = Wild('P', exclude=[f(x)]) + Q = Wild('Q', exclude=[f(x)]) + n = Wild('n', exclude=[x, f(x), f(x).diff(x)]) + return P, Q, n + + def _equation(self, fx, x, order): + P, Q, n = self.wilds() + return fx.diff(x) + P*fx - Q*fx**n + + def _get_general_solution(self, *, simplify_flag: bool = True): + P, Q, n = self.wilds_match() + fx = self.ode_problem.func + x = self.ode_problem.sym + (C1,) = self.ode_problem.get_numbered_constants(num=1) + if n==1: + gensol = Eq(log(fx), ( + C1 + Integral((-P + Q), x) + )) + else: + gensol = Eq(fx**(1-n), ( + (C1 - (n - 1) * Integral(Q*exp(-n*Integral(P, x)) + * exp(Integral(P, x)), x) + ) * exp(-(1 - n)*Integral(P, x))) + ) + return [gensol] + + +class Factorable(SingleODESolver): + r""" + Solves equations having a solvable factor. + + This function is used to solve the equation having factors. Factors may be of type algebraic or ode. It + will try to solve each factor independently. Factors will be solved by calling dsolve. We will return the + list of solutions. + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = (f(x)**2-4)*(f(x).diff(x)+f(x)) + >>> pprint(dsolve(eq, f(x))) + -x + [f(x) = 2, f(x) = -2, f(x) = C1*e ] + + + """ + hint = "factorable" + has_integral = False + + def _matches(self): + eq_orig = self.ode_problem.eq + f = self.ode_problem.func.func + x = self.ode_problem.sym + df = f(x).diff(x) + self.eqs = [] + eq = eq_orig.collect(f(x), func = cancel) + eq = fraction(factor(eq))[0] + factors = Mul.make_args(factor(eq)) + roots = [fac.as_base_exp() for fac in factors if len(fac.args)!=0] + if len(roots)>1 or roots[0][1]>1: + for base, expo in roots: + if base.has(f(x)): + self.eqs.append(base) + if len(self.eqs)>0: + return True + roots = solve(eq, df) + if len(roots)>0: + self.eqs = [(df - root) for root in roots] + # Avoid infinite recursion + matches = self.eqs != [eq_orig] + return matches + for i in factors: + if i.has(f(x)): + self.eqs.append(i) + return len(self.eqs)>0 and len(factors)>1 + + def _get_general_solution(self, *, simplify_flag: bool = True): + func = self.ode_problem.func.func + x = self.ode_problem.sym + eqns = self.eqs + sols = [] + for eq in eqns: + try: + sol = dsolve(eq, func(x)) + except NotImplementedError: + continue + else: + if isinstance(sol, list): + sols.extend(sol) + else: + sols.append(sol) + + if sols == []: + raise NotImplementedError("The given ODE " + str(eq) + " cannot be solved by" + + " the factorable group method") + return sols + + +class RiccatiSpecial(SinglePatternODESolver): + r""" + The general Riccati equation has the form + + .. math:: dy/dx = f(x) y^2 + g(x) y + h(x)\text{.} + + While it does not have a general solution [1], the "special" form, `dy/dx + = a y^2 - b x^c`, does have solutions in many cases [2]. This routine + returns a solution for `a(dy/dx) = b y^2 + c y/x + d/x^2` that is obtained + by using a suitable change of variables to reduce it to the special form + and is valid when neither `a` nor `b` are zero and either `c` or `d` is + zero. + + >>> from sympy.abc import x, a, b, c, d + >>> from sympy import dsolve, checkodesol, pprint, Function + >>> f = Function('f') + >>> y = f(x) + >>> genform = a*y.diff(x) - (b*y**2 + c*y/x + d/x**2) + >>> sol = dsolve(genform, y, hint="Riccati_special_minus2") + >>> pprint(sol, wrap_line=False) + / / __________________ \\ + | __________________ | / 2 || + | / 2 | \/ 4*b*d - (a + c) *log(x)|| + -|a + c - \/ 4*b*d - (a + c) *tan|C1 + ----------------------------|| + \ \ 2*a // + f(x) = ------------------------------------------------------------------------ + 2*b*x + + >>> checkodesol(genform, sol, order=1)[0] + True + + References + ========== + + - https://www.maplesoft.com/support/help/Maple/view.aspx?path=odeadvisor/Riccati + - https://eqworld.ipmnet.ru/en/solutions/ode/ode0106.pdf - + https://eqworld.ipmnet.ru/en/solutions/ode/ode0123.pdf + """ + hint = "Riccati_special_minus2" + has_integral = False + order = [1] + + def _wilds(self, f, x, order): + a = Wild('a', exclude=[x, f(x), f(x).diff(x), 0]) + b = Wild('b', exclude=[x, f(x), f(x).diff(x), 0]) + c = Wild('c', exclude=[x, f(x), f(x).diff(x)]) + d = Wild('d', exclude=[x, f(x), f(x).diff(x)]) + return a, b, c, d + + def _equation(self, fx, x, order): + a, b, c, d = self.wilds() + return a*fx.diff(x) + b*fx**2 + c*fx/x + d/x**2 + + def _get_general_solution(self, *, simplify_flag: bool = True): + a, b, c, d = self.wilds_match() + fx = self.ode_problem.func + x = self.ode_problem.sym + (C1,) = self.ode_problem.get_numbered_constants(num=1) + mu = sqrt(4*d*b - (a - c)**2) + + gensol = Eq(fx, (a - c - mu*tan(mu/(2*a)*log(x) + C1))/(2*b*x)) + return [gensol] + + +class RationalRiccati(SinglePatternODESolver): + r""" + Gives general solutions to the first order Riccati differential + equations that have atleast one rational particular solution. + + .. math :: y' = b_0(x) + b_1(x) y + b_2(x) y^2 + + where `b_0`, `b_1` and `b_2` are rational functions of `x` + with `b_2 \ne 0` (`b_2 = 0` would make it a Bernoulli equation). + + Examples + ======== + + >>> from sympy import Symbol, Function, dsolve, checkodesol + >>> f = Function('f') + >>> x = Symbol('x') + + >>> eq = -x**4*f(x)**2 + x**3*f(x).diff(x) + x**2*f(x) + 20 + >>> sol = dsolve(eq, hint="1st_rational_riccati") + >>> sol + Eq(f(x), (4*C1 - 5*x**9 - 4)/(x**2*(C1 + x**9 - 1))) + >>> checkodesol(eq, sol) + (True, 0) + + References + ========== + + - Riccati ODE: https://en.wikipedia.org/wiki/Riccati_equation + - N. Thieu Vo - Rational and Algebraic Solutions of First-Order Algebraic ODEs: + Algorithm 11, pp. 78 - https://www3.risc.jku.at/publications/download/risc_5387/PhDThesisThieu.pdf + """ + has_integral = False + hint = "1st_rational_riccati" + order = [1] + + def _wilds(self, f, x, order): + b0 = Wild('b0', exclude=[f(x), f(x).diff(x)]) + b1 = Wild('b1', exclude=[f(x), f(x).diff(x)]) + b2 = Wild('b2', exclude=[f(x), f(x).diff(x)]) + return (b0, b1, b2) + + def _equation(self, fx, x, order): + b0, b1, b2 = self.wilds() + return fx.diff(x) - b0 - b1*fx - b2*fx**2 + + def _matches(self): + eq = self.ode_problem.eq_expanded + f = self.ode_problem.func.func + x = self.ode_problem.sym + order = self.ode_problem.order + + if order != 1: + return False + + match, funcs = match_riccati(eq, f, x) + if not match: + return False + _b0, _b1, _b2 = funcs + b0, b1, b2 = self.wilds() + self._wilds_match = match = {b0: _b0, b1: _b1, b2: _b2} + return True + + def _get_general_solution(self, *, simplify_flag: bool = True): + # Match the equation + b0, b1, b2 = self.wilds_match() + fx = self.ode_problem.func + x = self.ode_problem.sym + return solve_riccati(fx, x, b0, b1, b2, gensol=True) + + +class SecondNonlinearAutonomousConserved(SinglePatternODESolver): + r""" + Gives solution for the autonomous second order nonlinear + differential equation of the form + + .. math :: f''(x) = g(f(x)) + + The solution for this differential equation can be computed + by multiplying by `f'(x)` and integrating on both sides, + converting it into a first order differential equation. + + Examples + ======== + + >>> from sympy import Function, symbols, dsolve + >>> f, g = symbols('f g', cls=Function) + >>> x = symbols('x') + + >>> eq = f(x).diff(x, 2) - g(f(x)) + >>> dsolve(eq, simplify=False) + [Eq(Integral(1/sqrt(C1 + 2*Integral(g(_u), _u)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(C1 + 2*Integral(g(_u), _u)), (_u, f(x))), C2 - x)] + + >>> from sympy import exp, log + >>> eq = f(x).diff(x, 2) - exp(f(x)) + log(f(x)) + >>> dsolve(eq, simplify=False) + [Eq(Integral(1/sqrt(-2*_u*log(_u) + 2*_u + C1 + 2*exp(_u)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(-2*_u*log(_u) + 2*_u + C1 + 2*exp(_u)), (_u, f(x))), C2 - x)] + + References + ========== + + - https://eqworld.ipmnet.ru/en/solutions/ode/ode0301.pdf + """ + hint = "2nd_nonlinear_autonomous_conserved" + has_integral = True + order = [2] + + def _wilds(self, f, x, order): + fy = Wild('fy', exclude=[0, f(x).diff(x), f(x).diff(x, 2)]) + return (fy, ) + + def _equation(self, fx, x, order): + fy = self.wilds()[0] + return fx.diff(x, 2) + fy + + def _verify(self, fx): + return self.ode_problem.is_autonomous + + def _get_general_solution(self, *, simplify_flag: bool = True): + g = self.wilds_match()[0] + fx = self.ode_problem.func + x = self.ode_problem.sym + u = Dummy('u') + g = g.subs(fx, u) + C1, C2 = self.ode_problem.get_numbered_constants(num=2) + inside = -2*Integral(g, u) + C1 + lhs = Integral(1/sqrt(inside), (u, fx)) + return [Eq(lhs, C2 + x), Eq(lhs, C2 - x)] + + +class Liouville(SinglePatternODESolver): + r""" + Solves 2nd order Liouville differential equations. + + The general form of a Liouville ODE is + + .. math:: \frac{d^2 y}{dx^2} + g(y) \left(\! + \frac{dy}{dx}\!\right)^2 + h(x) + \frac{dy}{dx}\text{.} + + The general solution is: + + >>> from sympy import Function, dsolve, Eq, pprint, diff + >>> from sympy.abc import x + >>> f, g, h = map(Function, ['f', 'g', 'h']) + >>> genform = Eq(diff(f(x),x,x) + g(f(x))*diff(f(x),x)**2 + + ... h(x)*diff(f(x),x), 0) + >>> pprint(genform) + 2 2 + /d \ d d + g(f(x))*|--(f(x))| + h(x)*--(f(x)) + ---(f(x)) = 0 + \dx / dx 2 + dx + >>> pprint(dsolve(genform, f(x), hint='Liouville_Integral')) + f(x) + / / + | | + | / | / + | | | | + | - | h(x) dx | | g(y) dy + | | | | + | / | / + C1 + C2* | e dx + | e dy = 0 + | | + / / + + Examples + ======== + + >>> from sympy import Function, dsolve, Eq, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(diff(f(x), x, x) + diff(f(x), x)**2/f(x) + + ... diff(f(x), x)/x, f(x), hint='Liouville')) + ________________ ________________ + [f(x) = -\/ C1 + C2*log(x) , f(x) = \/ C1 + C2*log(x) ] + + References + ========== + + - Goldstein and Braun, "Advanced Methods for the Solution of Differential + Equations", pp. 98 + - https://www.maplesoft.com/support/help/Maple/view.aspx?path=odeadvisor/Liouville + + # indirect doctest + + """ + hint = "Liouville" + has_integral = True + order = [2] + + def _wilds(self, f, x, order): + d = Wild('d', exclude=[f(x).diff(x), f(x).diff(x, 2)]) + e = Wild('e', exclude=[f(x).diff(x)]) + k = Wild('k', exclude=[f(x).diff(x)]) + return d, e, k + + def _equation(self, fx, x, order): + # Liouville ODE in the form + # f(x).diff(x, 2) + g(f(x))*(f(x).diff(x))**2 + h(x)*f(x).diff(x) + # See Goldstein and Braun, "Advanced Methods for the Solution of + # Differential Equations", pg. 98 + d, e, k = self.wilds() + return d*fx.diff(x, 2) + e*fx.diff(x)**2 + k*fx.diff(x) + + def _verify(self, fx): + d, e, k = self.wilds_match() + self.y = Dummy('y') + x = self.ode_problem.sym + self.g = simplify(e/d).subs(fx, self.y) + self.h = simplify(k/d).subs(fx, self.y) + if self.y in self.h.free_symbols or x in self.g.free_symbols: + return False + return True + + def _get_general_solution(self, *, simplify_flag: bool = True): + d, e, k = self.wilds_match() + fx = self.ode_problem.func + x = self.ode_problem.sym + C1, C2 = self.ode_problem.get_numbered_constants(num=2) + int = Integral(exp(Integral(self.g, self.y)), (self.y, None, fx)) + gen_sol = Eq(int + C1*Integral(exp(-Integral(self.h, x)), x) + C2, 0) + + return [gen_sol] + + +class Separable(SinglePatternODESolver): + r""" + Solves separable 1st order differential equations. + + This is any differential equation that can be written as `P(y) + \tfrac{dy}{dx} = Q(x)`. The solution can then just be found by + rearranging terms and integrating: `\int P(y) \,dy = \int Q(x) \,dx`. + This hint uses :py:meth:`sympy.simplify.simplify.separatevars` as its back + end, so if a separable equation is not caught by this solver, it is most + likely the fault of that function. + :py:meth:`~sympy.simplify.simplify.separatevars` is + smart enough to do most expansion and factoring necessary to convert a + separable equation `F(x, y)` into the proper form `P(x)\cdot{}Q(y)`. The + general solution is:: + + >>> from sympy import Function, dsolve, Eq, pprint + >>> from sympy.abc import x + >>> a, b, c, d, f = map(Function, ['a', 'b', 'c', 'd', 'f']) + >>> genform = Eq(a(x)*b(f(x))*f(x).diff(x), c(x)*d(f(x))) + >>> pprint(genform) + d + a(x)*b(f(x))*--(f(x)) = c(x)*d(f(x)) + dx + >>> pprint(dsolve(genform, f(x), hint='separable_Integral')) + f(x) + / / + | | + | b(y) | c(x) + | ---- dy = C1 + | ---- dx + | d(y) | a(x) + | | + / / + + Examples + ======== + + >>> from sympy import Function, dsolve, Eq + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(Eq(f(x)*f(x).diff(x) + x, 3*x*f(x)**2), f(x), + ... hint='separable', simplify=False)) + / 2 \ 2 + log\3*f (x) - 1/ x + ---------------- = C1 + -- + 6 2 + + References + ========== + + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 52 + + # indirect doctest + + """ + hint = "separable" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + d = Wild('d', exclude=[f(x).diff(x), f(x).diff(x, 2)]) + e = Wild('e', exclude=[f(x).diff(x)]) + return d, e + + def _equation(self, fx, x, order): + d, e = self.wilds() + return d + e*fx.diff(x) + + def _verify(self, fx): + d, e = self.wilds_match() + self.y = Dummy('y') + x = self.ode_problem.sym + d = separatevars(d.subs(fx, self.y)) + e = separatevars(e.subs(fx, self.y)) + # m1[coeff]*m1[x]*m1[y] + m2[coeff]*m2[x]*m2[y]*y' + self.m1 = separatevars(d, dict=True, symbols=(x, self.y)) + self.m2 = separatevars(e, dict=True, symbols=(x, self.y)) + return bool(self.m1 and self.m2) + + def _get_match_object(self): + fx = self.ode_problem.func + x = self.ode_problem.sym + return self.m1, self.m2, x, fx + + def _get_general_solution(self, *, simplify_flag: bool = True): + m1, m2, x, fx = self._get_match_object() + (C1,) = self.ode_problem.get_numbered_constants(num=1) + int = Integral(m2['coeff']*m2[self.y]/m1[self.y], + (self.y, None, fx)) + gen_sol = Eq(int, Integral(-m1['coeff']*m1[x]/ + m2[x], x) + C1) + return [gen_sol] + + +class SeparableReduced(Separable): + r""" + Solves a differential equation that can be reduced to the separable form. + + The general form of this equation is + + .. math:: y' + (y/x) H(x^n y) = 0\text{}. + + This can be solved by substituting `u(y) = x^n y`. The equation then + reduces to the separable form `\frac{u'}{u (\mathrm{power} - H(u))} - + \frac{1}{x} = 0`. + + The general solution is: + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x, n + >>> f, g = map(Function, ['f', 'g']) + >>> genform = f(x).diff(x) + (f(x)/x)*g(x**n*f(x)) + >>> pprint(genform) + / n \ + d f(x)*g\x *f(x)/ + --(f(x)) + --------------- + dx x + >>> pprint(dsolve(genform, hint='separable_reduced')) + n + x *f(x) + / + | + | 1 + | ------------ dy = C1 + log(x) + | y*(n - g(y)) + | + / + + See Also + ======== + :obj:`sympy.solvers.ode.single.Separable` + + Examples + ======== + + >>> from sympy import dsolve, Function, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> d = f(x).diff(x) + >>> eq = (x - x**2*f(x))*d - f(x) + >>> dsolve(eq, hint='separable_reduced') + [Eq(f(x), (1 - sqrt(C1*x**2 + 1))/x), Eq(f(x), (sqrt(C1*x**2 + 1) + 1)/x)] + >>> pprint(dsolve(eq, hint='separable_reduced')) + ___________ ___________ + / 2 / 2 + 1 - \/ C1*x + 1 \/ C1*x + 1 + 1 + [f(x) = ------------------, f(x) = ------------------] + x x + + References + ========== + + - Joel Moses, "Symbolic Integration - The Stormy Decade", Communications + of the ACM, Volume 14, Number 8, August 1971, pp. 558 + """ + hint = "separable_reduced" + has_integral = True + order = [1] + + def _degree(self, expr, x): + # Made this function to calculate the degree of + # x in an expression. If expr will be of form + # x**p*y, (wheare p can be variables/rationals) then it + # will return p. + for val in expr: + if val.has(x): + if isinstance(val, Pow) and val.as_base_exp()[0] == x: + return (val.as_base_exp()[1]) + elif val == x: + return (val.as_base_exp()[1]) + else: + return self._degree(val.args, x) + return 0 + + def _powers(self, expr): + # this function will return all the different relative power of x w.r.t f(x). + # expr = x**p * f(x)**q then it will return {p/q}. + pows = set() + fx = self.ode_problem.func + x = self.ode_problem.sym + self.y = Dummy('y') + if isinstance(expr, Add): + exprs = expr.atoms(Add) + elif isinstance(expr, Mul): + exprs = expr.atoms(Mul) + elif isinstance(expr, Pow): + exprs = expr.atoms(Pow) + else: + exprs = {expr} + + for arg in exprs: + if arg.has(x): + _, u = arg.as_independent(x, fx) + pow = self._degree((u.subs(fx, self.y), ), x)/self._degree((u.subs(fx, self.y), ), self.y) + pows.add(pow) + return pows + + def _verify(self, fx): + num, den = self.wilds_match() + x = self.ode_problem.sym + factor = simplify(x/fx*num/den) + # Try representing factor in terms of x^n*y + # where n is lowest power of x in factor; + # first remove terms like sqrt(2)*3 from factor.atoms(Mul) + num, dem = factor.as_numer_denom() + num = expand(num) + dem = expand(dem) + pows = self._powers(num) + pows.update(self._powers(dem)) + pows = list(pows) + if(len(pows)==1) and pows[0]!=zoo: + self.t = Dummy('t') + self.r2 = {'t': self.t} + num = num.subs(x**pows[0]*fx, self.t) + dem = dem.subs(x**pows[0]*fx, self.t) + test = num/dem + free = test.free_symbols + if len(free) == 1 and free.pop() == self.t: + self.r2.update({'power' : pows[0], 'u' : test}) + return True + return False + return False + + def _get_match_object(self): + fx = self.ode_problem.func + x = self.ode_problem.sym + u = self.r2['u'].subs(self.r2['t'], self.y) + ycoeff = 1/(self.y*(self.r2['power'] - u)) + m1 = {self.y: 1, x: -1/x, 'coeff': 1} + m2 = {self.y: ycoeff, x: 1, 'coeff': 1} + return m1, m2, x, x**self.r2['power']*fx + + +class HomogeneousCoeffSubsDepDivIndep(SinglePatternODESolver): + r""" + Solves a 1st order differential equation with homogeneous coefficients + using the substitution `u_1 = \frac{\text{}}{\text{}}`. + + This is a differential equation + + .. math:: P(x, y) + Q(x, y) dy/dx = 0 + + such that `P` and `Q` are homogeneous and of the same order. A function + `F(x, y)` is homogeneous of order `n` if `F(x t, y t) = t^n F(x, y)`. + Equivalently, `F(x, y)` can be rewritten as `G(y/x)` or `H(x/y)`. See + also the docstring of :py:meth:`~sympy.solvers.ode.homogeneous_order`. + + If the coefficients `P` and `Q` in the differential equation above are + homogeneous functions of the same order, then it can be shown that the + substitution `y = u_1 x` (i.e. `u_1 = y/x`) will turn the differential + equation into an equation separable in the variables `x` and `u`. If + `h(u_1)` is the function that results from making the substitution `u_1 = + f(x)/x` on `P(x, f(x))` and `g(u_2)` is the function that results from the + substitution on `Q(x, f(x))` in the differential equation `P(x, f(x)) + + Q(x, f(x)) f'(x) = 0`, then the general solution is:: + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f, g, h = map(Function, ['f', 'g', 'h']) + >>> genform = g(f(x)/x) + h(f(x)/x)*f(x).diff(x) + >>> pprint(genform) + /f(x)\ /f(x)\ d + g|----| + h|----|*--(f(x)) + \ x / \ x / dx + >>> pprint(dsolve(genform, f(x), + ... hint='1st_homogeneous_coeff_subs_dep_div_indep_Integral')) + f(x) + ---- + x + / + | + | -h(u1) + log(x) = C1 + | ---------------- d(u1) + | u1*h(u1) + g(u1) + | + / + + Where `u_1 h(u_1) + g(u_1) \ne 0` and `x \ne 0`. + + See also the docstrings of + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffBest` and + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffSubsIndepDivDep`. + + Examples + ======== + + >>> from sympy import Function, dsolve + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(2*x*f(x) + (x**2 + f(x)**2)*f(x).diff(x), f(x), + ... hint='1st_homogeneous_coeff_subs_dep_div_indep', simplify=False)) + / 3 \ + |3*f(x) f (x)| + log|------ + -----| + | x 3 | + \ x / + log(x) = log(C1) - ------------------- + 3 + + References + ========== + + - https://en.wikipedia.org/wiki/Homogeneous_differential_equation + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 59 + + # indirect doctest + + """ + hint = "1st_homogeneous_coeff_subs_dep_div_indep" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + d = Wild('d', exclude=[f(x).diff(x), f(x).diff(x, 2)]) + e = Wild('e', exclude=[f(x).diff(x)]) + return d, e + + def _equation(self, fx, x, order): + d, e = self.wilds() + return d + e*fx.diff(x) + + def _verify(self, fx): + self.d, self.e = self.wilds_match() + self.y = Dummy('y') + x = self.ode_problem.sym + self.d = separatevars(self.d.subs(fx, self.y)) + self.e = separatevars(self.e.subs(fx, self.y)) + ordera = homogeneous_order(self.d, x, self.y) + orderb = homogeneous_order(self.e, x, self.y) + if ordera == orderb and ordera is not None: + self.u = Dummy('u') + if simplify((self.d + self.u*self.e).subs({x: 1, self.y: self.u})) != 0: + return True + return False + return False + + def _get_match_object(self): + fx = self.ode_problem.func + x = self.ode_problem.sym + self.u1 = Dummy('u1') + xarg = 0 + yarg = 0 + return [self.d, self.e, fx, x, self.u, self.u1, self.y, xarg, yarg] + + def _get_general_solution(self, *, simplify_flag: bool = True): + d, e, fx, x, u, u1, y, xarg, yarg = self._get_match_object() + (C1,) = self.ode_problem.get_numbered_constants(num=1) + int = Integral( + (-e/(d + u1*e)).subs({x: 1, y: u1}), + (u1, None, fx/x)) + sol = logcombine(Eq(log(x), int + log(C1)), force=True) + gen_sol = sol.subs(fx, u).subs(((u, u - yarg), (x, x - xarg), (u, fx))) + return [gen_sol] + + +class HomogeneousCoeffSubsIndepDivDep(SinglePatternODESolver): + r""" + Solves a 1st order differential equation with homogeneous coefficients + using the substitution `u_2 = \frac{\text{}}{\text{}}`. + + This is a differential equation + + .. math:: P(x, y) + Q(x, y) dy/dx = 0 + + such that `P` and `Q` are homogeneous and of the same order. A function + `F(x, y)` is homogeneous of order `n` if `F(x t, y t) = t^n F(x, y)`. + Equivalently, `F(x, y)` can be rewritten as `G(y/x)` or `H(x/y)`. See + also the docstring of :py:meth:`~sympy.solvers.ode.homogeneous_order`. + + If the coefficients `P` and `Q` in the differential equation above are + homogeneous functions of the same order, then it can be shown that the + substitution `x = u_2 y` (i.e. `u_2 = x/y`) will turn the differential + equation into an equation separable in the variables `y` and `u_2`. If + `h(u_2)` is the function that results from making the substitution `u_2 = + x/f(x)` on `P(x, f(x))` and `g(u_2)` is the function that results from the + substitution on `Q(x, f(x))` in the differential equation `P(x, f(x)) + + Q(x, f(x)) f'(x) = 0`, then the general solution is: + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f, g, h = map(Function, ['f', 'g', 'h']) + >>> genform = g(x/f(x)) + h(x/f(x))*f(x).diff(x) + >>> pprint(genform) + / x \ / x \ d + g|----| + h|----|*--(f(x)) + \f(x)/ \f(x)/ dx + >>> pprint(dsolve(genform, f(x), + ... hint='1st_homogeneous_coeff_subs_indep_div_dep_Integral')) + x + ---- + f(x) + / + | + | -g(u1) + | ---------------- d(u1) + | u1*g(u1) + h(u1) + | + / + + f(x) = C1*e + + Where `u_1 g(u_1) + h(u_1) \ne 0` and `f(x) \ne 0`. + + See also the docstrings of + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffBest` and + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffSubsDepDivIndep`. + + Examples + ======== + + >>> from sympy import Function, pprint, dsolve + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(2*x*f(x) + (x**2 + f(x)**2)*f(x).diff(x), f(x), + ... hint='1st_homogeneous_coeff_subs_indep_div_dep', + ... simplify=False)) + / 2 \ + |3*x | + log|----- + 1| + | 2 | + \f (x) / + log(f(x)) = log(C1) - -------------- + 3 + + References + ========== + + - https://en.wikipedia.org/wiki/Homogeneous_differential_equation + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 59 + + # indirect doctest + + """ + hint = "1st_homogeneous_coeff_subs_indep_div_dep" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + d = Wild('d', exclude=[f(x).diff(x), f(x).diff(x, 2)]) + e = Wild('e', exclude=[f(x).diff(x)]) + return d, e + + def _equation(self, fx, x, order): + d, e = self.wilds() + return d + e*fx.diff(x) + + def _verify(self, fx): + self.d, self.e = self.wilds_match() + self.y = Dummy('y') + x = self.ode_problem.sym + self.d = separatevars(self.d.subs(fx, self.y)) + self.e = separatevars(self.e.subs(fx, self.y)) + ordera = homogeneous_order(self.d, x, self.y) + orderb = homogeneous_order(self.e, x, self.y) + if ordera == orderb and ordera is not None: + self.u = Dummy('u') + if simplify((self.e + self.u*self.d).subs({x: self.u, self.y: 1})) != 0: + return True + return False + return False + + def _get_match_object(self): + fx = self.ode_problem.func + x = self.ode_problem.sym + self.u1 = Dummy('u1') + xarg = 0 + yarg = 0 + return [self.d, self.e, fx, x, self.u, self.u1, self.y, xarg, yarg] + + def _get_general_solution(self, *, simplify_flag: bool = True): + d, e, fx, x, u, u1, y, xarg, yarg = self._get_match_object() + (C1,) = self.ode_problem.get_numbered_constants(num=1) + int = Integral(simplify((-d/(e + u1*d)).subs({x: u1, y: 1})), (u1, None, x/fx)) # type: ignore + sol = logcombine(Eq(log(fx), int + log(C1)), force=True) + gen_sol = sol.subs(fx, u).subs(((u, u - yarg), (x, x - xarg), (u, fx))) + return [gen_sol] + + +class HomogeneousCoeffBest(HomogeneousCoeffSubsIndepDivDep, HomogeneousCoeffSubsDepDivIndep): + r""" + Returns the best solution to an ODE from the two hints + ``1st_homogeneous_coeff_subs_dep_div_indep`` and + ``1st_homogeneous_coeff_subs_indep_div_dep``. + + This is as determined by :py:meth:`~sympy.solvers.ode.ode.ode_sol_simplicity`. + + See the + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffSubsIndepDivDep` + and + :obj:`~sympy.solvers.ode.single.HomogeneousCoeffSubsDepDivIndep` + docstrings for more information on these hints. Note that there is no + ``ode_1st_homogeneous_coeff_best_Integral`` hint. + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(2*x*f(x) + (x**2 + f(x)**2)*f(x).diff(x), f(x), + ... hint='1st_homogeneous_coeff_best', simplify=False)) + / 2 \ + |3*x | + log|----- + 1| + | 2 | + \f (x) / + log(f(x)) = log(C1) - -------------- + 3 + + References + ========== + + - https://en.wikipedia.org/wiki/Homogeneous_differential_equation + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 59 + + # indirect doctest + + """ + hint = "1st_homogeneous_coeff_best" + has_integral = False + order = [1] + + def _verify(self, fx): + return HomogeneousCoeffSubsIndepDivDep._verify(self, fx) and \ + HomogeneousCoeffSubsDepDivIndep._verify(self, fx) + + def _get_general_solution(self, *, simplify_flag: bool = True): + # There are two substitutions that solve the equation, u1=y/x and u2=x/y + # # They produce different integrals, so try them both and see which + # # one is easier + sol1 = HomogeneousCoeffSubsIndepDivDep._get_general_solution(self) + sol2 = HomogeneousCoeffSubsDepDivIndep._get_general_solution(self) + fx = self.ode_problem.func + if simplify_flag: + sol1 = odesimp(self.ode_problem.eq, *sol1, fx, "1st_homogeneous_coeff_subs_indep_div_dep") + sol2 = odesimp(self.ode_problem.eq, *sol2, fx, "1st_homogeneous_coeff_subs_dep_div_indep") + # XXX: not simplify should be not simplify_flag. mypy correctly complains + return min([sol1, sol2], key=lambda x: ode_sol_simplicity(x, fx, trysolving=not simplify)) # type: ignore + + +class LinearCoefficients(HomogeneousCoeffBest): + r""" + Solves a differential equation with linear coefficients. + + The general form of a differential equation with linear coefficients is + + .. math:: y' + F\left(\!\frac{a_1 x + b_1 y + c_1}{a_2 x + b_2 y + + c_2}\!\right) = 0\text{,} + + where `a_1`, `b_1`, `c_1`, `a_2`, `b_2`, `c_2` are constants and `a_1 b_2 + - a_2 b_1 \ne 0`. + + This can be solved by substituting: + + .. math:: x = x' + \frac{b_2 c_1 - b_1 c_2}{a_2 b_1 - a_1 b_2} + + y = y' + \frac{a_1 c_2 - a_2 c_1}{a_2 b_1 - a_1 + b_2}\text{.} + + This substitution reduces the equation to a homogeneous differential + equation. + + See Also + ======== + :obj:`sympy.solvers.ode.single.HomogeneousCoeffBest` + :obj:`sympy.solvers.ode.single.HomogeneousCoeffSubsIndepDivDep` + :obj:`sympy.solvers.ode.single.HomogeneousCoeffSubsDepDivIndep` + + Examples + ======== + + >>> from sympy import dsolve, Function, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> df = f(x).diff(x) + >>> eq = (x + f(x) + 1)*df + (f(x) - 6*x + 1) + >>> dsolve(eq, hint='linear_coefficients') + [Eq(f(x), -x - sqrt(C1 + 7*x**2) - 1), Eq(f(x), -x + sqrt(C1 + 7*x**2) - 1)] + >>> pprint(dsolve(eq, hint='linear_coefficients')) + ___________ ___________ + / 2 / 2 + [f(x) = -x - \/ C1 + 7*x - 1, f(x) = -x + \/ C1 + 7*x - 1] + + + References + ========== + + - Joel Moses, "Symbolic Integration - The Stormy Decade", Communications + of the ACM, Volume 14, Number 8, August 1971, pp. 558 + """ + hint = "linear_coefficients" + has_integral = True + order = [1] + + def _wilds(self, f, x, order): + d = Wild('d', exclude=[f(x).diff(x), f(x).diff(x, 2)]) + e = Wild('e', exclude=[f(x).diff(x)]) + return d, e + + def _equation(self, fx, x, order): + d, e = self.wilds() + return d + e*fx.diff(x) + + def _verify(self, fx): + self.d, self.e = self.wilds_match() + a, b = self.wilds() + F = self.d/self.e + x = self.ode_problem.sym + params = self._linear_coeff_match(F, fx) + if params: + self.xarg, self.yarg = params + u = Dummy('u') + t = Dummy('t') + self.y = Dummy('y') + # Dummy substitution for df and f(x). + dummy_eq = self.ode_problem.eq.subs(((fx.diff(x), t), (fx, u))) + reps = ((x, x + self.xarg), (u, u + self.yarg), (t, fx.diff(x)), (u, fx)) + dummy_eq = simplify(dummy_eq.subs(reps)) + # get the re-cast values for e and d + r2 = collect(expand(dummy_eq), [fx.diff(x), fx]).match(a*fx.diff(x) + b) + if r2: + self.d, self.e = r2[b], r2[a] + orderd = homogeneous_order(self.d, x, fx) + ordere = homogeneous_order(self.e, x, fx) + if orderd == ordere and orderd is not None: + self.d = self.d.subs(fx, self.y) + self.e = self.e.subs(fx, self.y) + return True + return False + return False + + def _linear_coeff_match(self, expr, func): + r""" + Helper function to match hint ``linear_coefficients``. + + Matches the expression to the form `(a_1 x + b_1 f(x) + c_1)/(a_2 x + b_2 + f(x) + c_2)` where the following conditions hold: + + 1. `a_1`, `b_1`, `c_1`, `a_2`, `b_2`, `c_2` are Rationals; + 2. `c_1` or `c_2` are not equal to zero; + 3. `a_2 b_1 - a_1 b_2` is not equal to zero. + + Return ``xarg``, ``yarg`` where + + 1. ``xarg`` = `(b_2 c_1 - b_1 c_2)/(a_2 b_1 - a_1 b_2)` + 2. ``yarg`` = `(a_1 c_2 - a_2 c_1)/(a_2 b_1 - a_1 b_2)` + + + Examples + ======== + + >>> from sympy import Function, sin + >>> from sympy.abc import x + >>> from sympy.solvers.ode.single import LinearCoefficients + >>> f = Function('f') + >>> eq = (-25*f(x) - 8*x + 62)/(4*f(x) + 11*x - 11) + >>> obj = LinearCoefficients(eq) + >>> obj._linear_coeff_match(eq, f(x)) + (1/9, 22/9) + >>> eq = sin((-5*f(x) - 8*x + 6)/(4*f(x) + x - 1)) + >>> obj = LinearCoefficients(eq) + >>> obj._linear_coeff_match(eq, f(x)) + (19/27, 2/27) + >>> eq = sin(f(x)/x) + >>> obj = LinearCoefficients(eq) + >>> obj._linear_coeff_match(eq, f(x)) + + """ + f = func.func + x = func.args[0] + def abc(eq): + r''' + Internal function of _linear_coeff_match + that returns Rationals a, b, c + if eq is a*x + b*f(x) + c, else None. + ''' + eq = _mexpand(eq) + c = eq.as_independent(x, f(x), as_Add=True)[0] + if not c.is_Rational: + return + a = eq.coeff(x) + if not a.is_Rational: + return + b = eq.coeff(f(x)) + if not b.is_Rational: + return + if eq == a*x + b*f(x) + c: + return a, b, c + + def match(arg): + r''' + Internal function of _linear_coeff_match that returns Rationals a1, + b1, c1, a2, b2, c2 and a2*b1 - a1*b2 of the expression (a1*x + b1*f(x) + + c1)/(a2*x + b2*f(x) + c2) if one of c1 or c2 and a2*b1 - a1*b2 is + non-zero, else None. + ''' + n, d = arg.together().as_numer_denom() + m = abc(n) + if m is not None: + a1, b1, c1 = m + m = abc(d) + if m is not None: + a2, b2, c2 = m + d = a2*b1 - a1*b2 + if (c1 or c2) and d: + return a1, b1, c1, a2, b2, c2, d + + m = [fi.args[0] for fi in expr.atoms(Function) if fi.func != f and + len(fi.args) == 1 and not fi.args[0].is_Function] or {expr} + m1 = match(m.pop()) + if m1 and all(match(mi) == m1 for mi in m): + a1, b1, c1, a2, b2, c2, denom = m1 + return (b2*c1 - b1*c2)/denom, (a1*c2 - a2*c1)/denom + + def _get_match_object(self): + fx = self.ode_problem.func + x = self.ode_problem.sym + self.u1 = Dummy('u1') + u = Dummy('u') + return [self.d, self.e, fx, x, u, self.u1, self.y, self.xarg, self.yarg] + + +class NthOrderReducible(SingleODESolver): + r""" + Solves ODEs that only involve derivatives of the dependent variable using + a substitution of the form `f^n(x) = g(x)`. + + For example any second order ODE of the form `f''(x) = h(f'(x), x)` can be + transformed into a pair of 1st order ODEs `g'(x) = h(g(x), x)` and + `f'(x) = g(x)`. Usually the 1st order ODE for `g` is easier to solve. If + that gives an explicit solution for `g` then `f` is found simply by + integration. + + + Examples + ======== + + >>> from sympy import Function, dsolve, Eq + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = Eq(x*f(x).diff(x)**2 + f(x).diff(x, 2), 0) + >>> dsolve(eq, f(x), hint='nth_order_reducible') + ... # doctest: +NORMALIZE_WHITESPACE + Eq(f(x), C1 - sqrt(-1/C2)*log(-C2*sqrt(-1/C2) + x) + sqrt(-1/C2)*log(C2*sqrt(-1/C2) + x)) + + """ + hint = "nth_order_reducible" + has_integral = False + + def _matches(self): + # Any ODE that can be solved with a substitution and + # repeated integration e.g.: + # `d^2/dx^2(y) + x*d/dx(y) = constant + #f'(x) must be finite for this to work + eq = self.ode_problem.eq_preprocessed + func = self.ode_problem.func + x = self.ode_problem.sym + r""" + Matches any differential equation that can be rewritten with a smaller + order. Only derivatives of ``func`` alone, wrt a single variable, + are considered, and only in them should ``func`` appear. + """ + # ODE only handles functions of 1 variable so this affirms that state + assert len(func.args) == 1 + vc = [d.variable_count[0] for d in eq.atoms(Derivative) + if d.expr == func and len(d.variable_count) == 1] + ords = [c for v, c in vc if v == x] + if len(ords) < 2: + return False + self.smallest = min(ords) + # make sure func does not appear outside of derivatives + D = Dummy() + if eq.subs(func.diff(x, self.smallest), D).has(func): + return False + return True + + def _get_general_solution(self, *, simplify_flag: bool = True): + eq = self.ode_problem.eq + f = self.ode_problem.func.func + x = self.ode_problem.sym + n = self.smallest + # get a unique function name for g + names = [a.name for a in eq.atoms(AppliedUndef)] + while True: + name = Dummy().name + if name not in names: + g = Function(name) + break + w = f(x).diff(x, n) + geq = eq.subs(w, g(x)) + gsol = dsolve(geq, g(x)) + + if not isinstance(gsol, list): + gsol = [gsol] + + # Might be multiple solutions to the reduced ODE: + fsol = [] + for gsoli in gsol: + fsoli = dsolve(gsoli.subs(g(x), w), f(x)) # or do integration n times + fsol.append(fsoli) + + return fsol + + +class SecondHypergeometric(SingleODESolver): + r""" + Solves 2nd order linear differential equations. + + It computes special function solutions which can be expressed using the + 2F1, 1F1 or 0F1 hypergeometric functions. + + .. math:: y'' + A(x) y' + B(x) y = 0\text{,} + + where `A` and `B` are rational functions. + + These kinds of differential equations have solution of non-Liouvillian form. + + Given linear ODE can be obtained from 2F1 given by + + .. math:: (x^2 - x) y'' + ((a + b + 1) x - c) y' + b a y = 0\text{,} + + where {a, b, c} are arbitrary constants. + + Notes + ===== + + The algorithm should find any solution of the form + + .. math:: y = P(x) _pF_q(..; ..;\frac{\alpha x^k + \beta}{\gamma x^k + \delta})\text{,} + + where pFq is any of 2F1, 1F1 or 0F1 and `P` is an "arbitrary function". + Currently only the 2F1 case is implemented in SymPy but the other cases are + described in the paper and could be implemented in future (contributions + welcome!). + + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = (x*x - x)*f(x).diff(x,2) + (5*x - 1)*f(x).diff(x) + 4*f(x) + >>> pprint(dsolve(eq, f(x), '2nd_hypergeometric')) + _ + / / 4 \\ |_ /-1, -1 | \ + |C1 + C2*|log(x) + -----||* | | | x| + \ \ x + 1// 2 1 \ 1 | / + f(x) = -------------------------------------------- + 3 + (x - 1) + + + References + ========== + + - "Non-Liouvillian solutions for second order linear ODEs" by L. Chan, E.S. Cheb-Terrab + + """ + hint = "2nd_hypergeometric" + has_integral = True + + def _matches(self): + eq = self.ode_problem.eq_preprocessed + func = self.ode_problem.func + r = match_2nd_hypergeometric(eq, func) + self.match_object = None + if r: + A, B = r + d = equivalence_hypergeometric(A, B, func) + if d: + if d['type'] == "2F1": + self.match_object = match_2nd_2F1_hypergeometric(d['I0'], d['k'], d['sing_point'], func) + if self.match_object is not None: + self.match_object.update({'A':A, 'B':B}) + # We can extend it for 1F1 and 0F1 type also. + return self.match_object is not None + + def _get_general_solution(self, *, simplify_flag: bool = True): + eq = self.ode_problem.eq + func = self.ode_problem.func + if self.match_object['type'] == "2F1": + sol = get_sol_2F1_hypergeometric(eq, func, self.match_object) + if sol is None: + raise NotImplementedError("The given ODE " + str(eq) + " cannot be solved by" + + " the hypergeometric method") + + return [sol] + + +class NthLinearConstantCoeffHomogeneous(SingleODESolver): + r""" + Solves an `n`\th order linear homogeneous differential equation with + constant coefficients. + + This is an equation of the form + + .. math:: a_n f^{(n)}(x) + a_{n-1} f^{(n-1)}(x) + \cdots + a_1 f'(x) + + a_0 f(x) = 0\text{.} + + These equations can be solved in a general manner, by taking the roots of + the characteristic equation `a_n m^n + a_{n-1} m^{n-1} + \cdots + a_1 m + + a_0 = 0`. The solution will then be the sum of `C_n x^i e^{r x}` terms, + for each where `C_n` is an arbitrary constant, `r` is a root of the + characteristic equation and `i` is one of each from 0 to the multiplicity + of the root - 1 (for example, a root 3 of multiplicity 2 would create the + terms `C_1 e^{3 x} + C_2 x e^{3 x}`). The exponential is usually expanded + for complex roots using Euler's equation `e^{I x} = \cos(x) + I \sin(x)`. + Complex roots always come in conjugate pairs in polynomials with real + coefficients, so the two roots will be represented (after simplifying the + constants) as `e^{a x} \left(C_1 \cos(b x) + C_2 \sin(b x)\right)`. + + If SymPy cannot find exact roots to the characteristic equation, a + :py:class:`~sympy.polys.rootoftools.ComplexRootOf` instance will be return + instead. + + >>> from sympy import Function, dsolve + >>> from sympy.abc import x + >>> f = Function('f') + >>> dsolve(f(x).diff(x, 5) + 10*f(x).diff(x) - 2*f(x), f(x), + ... hint='nth_linear_constant_coeff_homogeneous') + ... # doctest: +NORMALIZE_WHITESPACE + Eq(f(x), C5*exp(x*CRootOf(_x**5 + 10*_x - 2, 0)) + + (C1*sin(x*im(CRootOf(_x**5 + 10*_x - 2, 1))) + + C2*cos(x*im(CRootOf(_x**5 + 10*_x - 2, 1))))*exp(x*re(CRootOf(_x**5 + 10*_x - 2, 1))) + + (C3*sin(x*im(CRootOf(_x**5 + 10*_x - 2, 3))) + + C4*cos(x*im(CRootOf(_x**5 + 10*_x - 2, 3))))*exp(x*re(CRootOf(_x**5 + 10*_x - 2, 3)))) + + Note that because this method does not involve integration, there is no + ``nth_linear_constant_coeff_homogeneous_Integral`` hint. + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(f(x).diff(x, 4) + 2*f(x).diff(x, 3) - + ... 2*f(x).diff(x, 2) - 6*f(x).diff(x) + 5*f(x), f(x), + ... hint='nth_linear_constant_coeff_homogeneous')) + x -2*x + f(x) = (C1 + C2*x)*e + (C3*sin(x) + C4*cos(x))*e + + References + ========== + + - https://en.wikipedia.org/wiki/Linear_differential_equation section: + Nonhomogeneous_equation_with_constant_coefficients + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 211 + + # indirect doctest + + """ + hint = "nth_linear_constant_coeff_homogeneous" + has_integral = False + + def _matches(self): + eq = self.ode_problem.eq_high_order_free + func = self.ode_problem.func + order = self.ode_problem.order + x = self.ode_problem.sym + self.r = self.ode_problem.get_linear_coefficients(eq, func, order) + if order and self.r and not any(self.r[i].has(x) for i in self.r if i >= 0): + if not self.r[-1]: + return True + else: + return False + return False + + def _get_general_solution(self, *, simplify_flag: bool = True): + fx = self.ode_problem.func + order = self.ode_problem.order + roots, collectterms = _get_const_characteristic_eq_sols(self.r, fx, order) + # A generator of constants + constants = self.ode_problem.get_numbered_constants(num=len(roots)) + gsol_rhs = Add(*[i*j for (i, j) in zip(constants, roots)]) + gsol = Eq(fx, gsol_rhs) + if simplify_flag: + gsol = _get_simplified_sol([gsol], fx, collectterms) + + return [gsol] + + +class NthLinearConstantCoeffVariationOfParameters(SingleODESolver): + r""" + Solves an `n`\th order linear differential equation with constant + coefficients using the method of variation of parameters. + + This method works on any differential equations of the form + + .. math:: f^{(n)}(x) + a_{n-1} f^{(n-1)}(x) + \cdots + a_1 f'(x) + a_0 + f(x) = P(x)\text{.} + + This method works by assuming that the particular solution takes the form + + .. math:: \sum_{x=1}^{n} c_i(x) y_i(x)\text{,} + + where `y_i` is the `i`\th solution to the homogeneous equation. The + solution is then solved using Wronskian's and Cramer's Rule. The + particular solution is given by + + .. math:: \sum_{x=1}^n \left( \int \frac{W_i(x)}{W(x)} \,dx + \right) y_i(x) \text{,} + + where `W(x)` is the Wronskian of the fundamental system (the system of `n` + linearly independent solutions to the homogeneous equation), and `W_i(x)` + is the Wronskian of the fundamental system with the `i`\th column replaced + with `[0, 0, \cdots, 0, P(x)]`. + + This method is general enough to solve any `n`\th order inhomogeneous + linear differential equation with constant coefficients, but sometimes + SymPy cannot simplify the Wronskian well enough to integrate it. If this + method hangs, try using the + ``nth_linear_constant_coeff_variation_of_parameters_Integral`` hint and + simplifying the integrals manually. Also, prefer using + ``nth_linear_constant_coeff_undetermined_coefficients`` when it + applies, because it does not use integration, making it faster and more + reliable. + + Warning, using simplify=False with + 'nth_linear_constant_coeff_variation_of_parameters' in + :py:meth:`~sympy.solvers.ode.dsolve` may cause it to hang, because it will + not attempt to simplify the Wronskian before integrating. It is + recommended that you only use simplify=False with + 'nth_linear_constant_coeff_variation_of_parameters_Integral' for this + method, especially if the solution to the homogeneous equation has + trigonometric functions in it. + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint, exp, log + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(f(x).diff(x, 3) - 3*f(x).diff(x, 2) + + ... 3*f(x).diff(x) - f(x) - exp(x)*log(x), f(x), + ... hint='nth_linear_constant_coeff_variation_of_parameters')) + / / / x*log(x) 11*x\\\ x + f(x) = |C1 + x*|C2 + x*|C3 + -------- - ----|||*e + \ \ \ 6 36 /// + + References + ========== + + - https://en.wikipedia.org/wiki/Variation_of_parameters + - https://planetmath.org/VariationOfParameters + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 233 + + # indirect doctest + + """ + hint = "nth_linear_constant_coeff_variation_of_parameters" + has_integral = True + + def _matches(self): + eq = self.ode_problem.eq_high_order_free + func = self.ode_problem.func + order = self.ode_problem.order + x = self.ode_problem.sym + self.r = self.ode_problem.get_linear_coefficients(eq, func, order) + + if order and self.r and not any(self.r[i].has(x) for i in self.r if i >= 0): + if self.r[-1]: + return True + else: + return False + return False + + def _get_general_solution(self, *, simplify_flag: bool = True): + eq = self.ode_problem.eq_high_order_free + f = self.ode_problem.func.func + x = self.ode_problem.sym + order = self.ode_problem.order + roots, collectterms = _get_const_characteristic_eq_sols(self.r, f(x), order) + # A generator of constants + constants = self.ode_problem.get_numbered_constants(num=len(roots)) + homogen_sol_rhs = Add(*[i*j for (i, j) in zip(constants, roots)]) + homogen_sol = Eq(f(x), homogen_sol_rhs) + homogen_sol = _solve_variation_of_parameters(eq, f(x), roots, homogen_sol, order, self.r, simplify_flag) + if simplify_flag: + homogen_sol = _get_simplified_sol([homogen_sol], f(x), collectterms) + return [homogen_sol] + + +class NthLinearConstantCoeffUndeterminedCoefficients(SingleODESolver): + r""" + Solves an `n`\th order linear differential equation with constant + coefficients using the method of undetermined coefficients. + + This method works on differential equations of the form + + .. math:: a_n f^{(n)}(x) + a_{n-1} f^{(n-1)}(x) + \cdots + a_1 f'(x) + + a_0 f(x) = P(x)\text{,} + + where `P(x)` is a function that has a finite number of linearly + independent derivatives. + + Functions that fit this requirement are finite sums functions of the form + `a x^i e^{b x} \sin(c x + d)` or `a x^i e^{b x} \cos(c x + d)`, where `i` + is a non-negative integer and `a`, `b`, `c`, and `d` are constants. For + example any polynomial in `x`, functions like `x^2 e^{2 x}`, `x \sin(x)`, + and `e^x \cos(x)` can all be used. Products of `\sin`'s and `\cos`'s have + a finite number of derivatives, because they can be expanded into `\sin(a + x)` and `\cos(b x)` terms. However, SymPy currently cannot do that + expansion, so you will need to manually rewrite the expression in terms of + the above to use this method. So, for example, you will need to manually + convert `\sin^2(x)` into `(1 + \cos(2 x))/2` to properly apply the method + of undetermined coefficients on it. + + This method works by creating a trial function from the expression and all + of its linear independent derivatives and substituting them into the + original ODE. The coefficients for each term will be a system of linear + equations, which are be solved for and substituted, giving the solution. + If any of the trial functions are linearly dependent on the solution to + the homogeneous equation, they are multiplied by sufficient `x` to make + them linearly independent. + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint, exp, cos + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(f(x).diff(x, 2) + 2*f(x).diff(x) + f(x) - + ... 4*exp(-x)*x**2 + cos(2*x), f(x), + ... hint='nth_linear_constant_coeff_undetermined_coefficients')) + / / 3\\ + | | x || -x 4*sin(2*x) 3*cos(2*x) + f(x) = |C1 + x*|C2 + --||*e - ---------- + ---------- + \ \ 3 // 25 25 + + References + ========== + + - https://en.wikipedia.org/wiki/Method_of_undetermined_coefficients + - M. Tenenbaum & H. Pollard, "Ordinary Differential Equations", + Dover 1963, pp. 221 + + # indirect doctest + + """ + hint = "nth_linear_constant_coeff_undetermined_coefficients" + has_integral = False + + def _matches(self): + eq = self.ode_problem.eq_high_order_free + func = self.ode_problem.func + order = self.ode_problem.order + x = self.ode_problem.sym + self.r = self.ode_problem.get_linear_coefficients(eq, func, order) + does_match = False + if order and self.r and not any(self.r[i].has(x) for i in self.r if i >= 0): + if self.r[-1]: + eq_homogeneous = Add(eq, -self.r[-1]) + undetcoeff = _undetermined_coefficients_match(self.r[-1], x, func, eq_homogeneous) + if undetcoeff['test']: + self.trialset = undetcoeff['trialset'] + does_match = True + return does_match + + def _get_general_solution(self, *, simplify_flag: bool = True): + eq = self.ode_problem.eq + f = self.ode_problem.func.func + x = self.ode_problem.sym + order = self.ode_problem.order + roots, collectterms = _get_const_characteristic_eq_sols(self.r, f(x), order) + # A generator of constants + constants = self.ode_problem.get_numbered_constants(num=len(roots)) + homogen_sol_rhs = Add(*[i*j for (i, j) in zip(constants, roots)]) + homogen_sol = Eq(f(x), homogen_sol_rhs) + self.r.update({'list': roots, 'sol': homogen_sol, 'simpliy_flag': simplify_flag}) + gsol = _solve_undetermined_coefficients(eq, f(x), order, self.r, self.trialset) + if simplify_flag: + gsol = _get_simplified_sol([gsol], f(x), collectterms) + return [gsol] + + +class NthLinearEulerEqHomogeneous(SingleODESolver): + r""" + Solves an `n`\th order linear homogeneous variable-coefficient + Cauchy-Euler equidimensional ordinary differential equation. + + This is an equation with form `0 = a_0 f(x) + a_1 x f'(x) + a_2 x^2 f''(x) + \cdots`. + + These equations can be solved in a general manner, by substituting + solutions of the form `f(x) = x^r`, and deriving a characteristic equation + for `r`. When there are repeated roots, we include extra terms of the + form `C_{r k} \ln^k(x) x^r`, where `C_{r k}` is an arbitrary integration + constant, `r` is a root of the characteristic equation, and `k` ranges + over the multiplicity of `r`. In the cases where the roots are complex, + solutions of the form `C_1 x^a \sin(b \log(x)) + C_2 x^a \cos(b \log(x))` + are returned, based on expansions with Euler's formula. The general + solution is the sum of the terms found. If SymPy cannot find exact roots + to the characteristic equation, a + :py:obj:`~.ComplexRootOf` instance will be returned + instead. + + >>> from sympy import Function, dsolve + >>> from sympy.abc import x + >>> f = Function('f') + >>> dsolve(4*x**2*f(x).diff(x, 2) + f(x), f(x), + ... hint='nth_linear_euler_eq_homogeneous') + ... # doctest: +NORMALIZE_WHITESPACE + Eq(f(x), sqrt(x)*(C1 + C2*log(x))) + + Note that because this method does not involve integration, there is no + ``nth_linear_euler_eq_homogeneous_Integral`` hint. + + The following is for internal use: + + - ``returns = 'sol'`` returns the solution to the ODE. + - ``returns = 'list'`` returns a list of linearly independent solutions, + corresponding to the fundamental solution set, for use with non + homogeneous solution methods like variation of parameters and + undetermined coefficients. Note that, though the solutions should be + linearly independent, this function does not explicitly check that. You + can do ``assert simplify(wronskian(sollist)) != 0`` to check for linear + independence. Also, ``assert len(sollist) == order`` will need to pass. + - ``returns = 'both'``, return a dictionary ``{'sol': , + 'list': }``. + + Examples + ======== + + >>> from sympy import Function, dsolve, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = f(x).diff(x, 2)*x**2 - 4*f(x).diff(x)*x + 6*f(x) + >>> pprint(dsolve(eq, f(x), + ... hint='nth_linear_euler_eq_homogeneous')) + 2 + f(x) = x *(C1 + C2*x) + + References + ========== + + - https://en.wikipedia.org/wiki/Cauchy%E2%80%93Euler_equation + - C. Bender & S. Orszag, "Advanced Mathematical Methods for Scientists and + Engineers", Springer 1999, pp. 12 + + # indirect doctest + + """ + hint = "nth_linear_euler_eq_homogeneous" + has_integral = False + + def _matches(self): + eq = self.ode_problem.eq_preprocessed + f = self.ode_problem.func.func + order = self.ode_problem.order + x = self.ode_problem.sym + match = self.ode_problem.get_linear_coefficients(eq, f(x), order) + self.r = None + does_match = False + + if order and match: + coeff = match[order] + factor = x**order / coeff + self.r = {i: factor*match[i] for i in match} + if self.r and all(_test_term(self.r[i], f(x), i) for i in + self.r if i >= 0): + if not self.r[-1]: + does_match = True + return does_match + + def _get_general_solution(self, *, simplify_flag: bool = True): + fx = self.ode_problem.func + eq = self.ode_problem.eq + homogen_sol = _get_euler_characteristic_eq_sols(eq, fx, self.r)[0] + return [homogen_sol] + + +class NthLinearEulerEqNonhomogeneousVariationOfParameters(SingleODESolver): + r""" + Solves an `n`\th order linear non homogeneous Cauchy-Euler equidimensional + ordinary differential equation using variation of parameters. + + This is an equation with form `g(x) = a_0 f(x) + a_1 x f'(x) + a_2 x^2 f''(x) + \cdots`. + + This method works by assuming that the particular solution takes the form + + .. math:: \sum_{x=1}^{n} c_i(x) y_i(x) {a_n} {x^n} \text{, } + + where `y_i` is the `i`\th solution to the homogeneous equation. The + solution is then solved using Wronskian's and Cramer's Rule. The + particular solution is given by multiplying eq given below with `a_n x^{n}` + + .. math:: \sum_{x=1}^n \left( \int \frac{W_i(x)}{W(x)} \, dx + \right) y_i(x) \text{, } + + where `W(x)` is the Wronskian of the fundamental system (the system of `n` + linearly independent solutions to the homogeneous equation), and `W_i(x)` + is the Wronskian of the fundamental system with the `i`\th column replaced + with `[0, 0, \cdots, 0, \frac{x^{- n}}{a_n} g{\left(x \right)}]`. + + This method is general enough to solve any `n`\th order inhomogeneous + linear differential equation, but sometimes SymPy cannot simplify the + Wronskian well enough to integrate it. If this method hangs, try using the + ``nth_linear_constant_coeff_variation_of_parameters_Integral`` hint and + simplifying the integrals manually. Also, prefer using + ``nth_linear_constant_coeff_undetermined_coefficients`` when it + applies, because it does not use integration, making it faster and more + reliable. + + Warning, using simplify=False with + 'nth_linear_constant_coeff_variation_of_parameters' in + :py:meth:`~sympy.solvers.ode.dsolve` may cause it to hang, because it will + not attempt to simplify the Wronskian before integrating. It is + recommended that you only use simplify=False with + 'nth_linear_constant_coeff_variation_of_parameters_Integral' for this + method, especially if the solution to the homogeneous equation has + trigonometric functions in it. + + Examples + ======== + + >>> from sympy import Function, dsolve, Derivative + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = x**2*Derivative(f(x), x, x) - 2*x*Derivative(f(x), x) + 2*f(x) - x**4 + >>> dsolve(eq, f(x), + ... hint='nth_linear_euler_eq_nonhomogeneous_variation_of_parameters').expand() + Eq(f(x), C1*x + C2*x**2 + x**4/6) + + """ + hint = "nth_linear_euler_eq_nonhomogeneous_variation_of_parameters" + has_integral = True + + def _matches(self): + eq = self.ode_problem.eq_preprocessed + f = self.ode_problem.func.func + order = self.ode_problem.order + x = self.ode_problem.sym + match = self.ode_problem.get_linear_coefficients(eq, f(x), order) + self.r = None + does_match = False + + if order and match: + coeff = match[order] + factor = x**order / coeff + self.r = {i: factor*match[i] for i in match} + if self.r and all(_test_term(self.r[i], f(x), i) for i in + self.r if i >= 0): + if self.r[-1]: + does_match = True + + return does_match + + def _get_general_solution(self, *, simplify_flag: bool = True): + eq = self.ode_problem.eq + f = self.ode_problem.func.func + x = self.ode_problem.sym + order = self.ode_problem.order + homogen_sol, roots = _get_euler_characteristic_eq_sols(eq, f(x), self.r) + self.r[-1] = self.r[-1]/self.r[order] + sol = _solve_variation_of_parameters(eq, f(x), roots, homogen_sol, order, self.r, simplify_flag) + + return [Eq(f(x), homogen_sol.rhs + (sol.rhs - homogen_sol.rhs)*self.r[order])] + + +class NthLinearEulerEqNonhomogeneousUndeterminedCoefficients(SingleODESolver): + r""" + Solves an `n`\th order linear non homogeneous Cauchy-Euler equidimensional + ordinary differential equation using undetermined coefficients. + + This is an equation with form `g(x) = a_0 f(x) + a_1 x f'(x) + a_2 x^2 f''(x) + \cdots`. + + These equations can be solved in a general manner, by substituting + solutions of the form `x = exp(t)`, and deriving a characteristic equation + of form `g(exp(t)) = b_0 f(t) + b_1 f'(t) + b_2 f''(t) \cdots` which can + be then solved by nth_linear_constant_coeff_undetermined_coefficients if + g(exp(t)) has finite number of linearly independent derivatives. + + Functions that fit this requirement are finite sums functions of the form + `a x^i e^{b x} \sin(c x + d)` or `a x^i e^{b x} \cos(c x + d)`, where `i` + is a non-negative integer and `a`, `b`, `c`, and `d` are constants. For + example any polynomial in `x`, functions like `x^2 e^{2 x}`, `x \sin(x)`, + and `e^x \cos(x)` can all be used. Products of `\sin`'s and `\cos`'s have + a finite number of derivatives, because they can be expanded into `\sin(a + x)` and `\cos(b x)` terms. However, SymPy currently cannot do that + expansion, so you will need to manually rewrite the expression in terms of + the above to use this method. So, for example, you will need to manually + convert `\sin^2(x)` into `(1 + \cos(2 x))/2` to properly apply the method + of undetermined coefficients on it. + + After replacement of x by exp(t), this method works by creating a trial function + from the expression and all of its linear independent derivatives and + substituting them into the original ODE. The coefficients for each term + will be a system of linear equations, which are be solved for and + substituted, giving the solution. If any of the trial functions are linearly + dependent on the solution to the homogeneous equation, they are multiplied + by sufficient `x` to make them linearly independent. + + Examples + ======== + + >>> from sympy import dsolve, Function, Derivative, log + >>> from sympy.abc import x + >>> f = Function('f') + >>> eq = x**2*Derivative(f(x), x, x) - 2*x*Derivative(f(x), x) + 2*f(x) - log(x) + >>> dsolve(eq, f(x), + ... hint='nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients').expand() + Eq(f(x), C1*x + C2*x**2 + log(x)/2 + 3/4) + + """ + hint = "nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients" + has_integral = False + + def _matches(self): + eq = self.ode_problem.eq_high_order_free + f = self.ode_problem.func.func + order = self.ode_problem.order + x = self.ode_problem.sym + match = self.ode_problem.get_linear_coefficients(eq, f(x), order) + self.r = None + does_match = False + + if order and match: + coeff = match[order] + factor = x**order / coeff + self.r = {i: factor*match[i] for i in match} + if self.r and all(_test_term(self.r[i], f(x), i) for i in + self.r if i >= 0): + if self.r[-1]: + e, re = posify(self.r[-1].subs(x, exp(x))) + undetcoeff = _undetermined_coefficients_match(e.subs(re), x) + if undetcoeff['test']: + does_match = True + return does_match + + def _get_general_solution(self, *, simplify_flag: bool = True): + f = self.ode_problem.func.func + x = self.ode_problem.sym + chareq, eq, symbol = S.Zero, S.Zero, Dummy('x') + for i in self.r.keys(): + if i >= 0: + chareq += (self.r[i]*diff(x**symbol, x, i)*x**-symbol).expand() + + for i in range(1, degree(Poly(chareq, symbol))+1): + eq += chareq.coeff(symbol**i)*diff(f(x), x, i) + + if chareq.as_coeff_add(symbol)[0]: + eq += chareq.as_coeff_add(symbol)[0]*f(x) + e, re = posify(self.r[-1].subs(x, exp(x))) + eq += e.subs(re) + + self.const_undet_instance = NthLinearConstantCoeffUndeterminedCoefficients(SingleODEProblem(eq, f(x), x)) + sol = self.const_undet_instance.get_general_solution(simplify = simplify_flag)[0] + sol = sol.subs(x, log(x)) # type: ignore + sol = sol.subs(f(log(x)), f(x)).expand() # type: ignore + + return [sol] + + +class SecondLinearBessel(SingleODESolver): + r""" + Gives solution of the Bessel differential equation + + .. math :: x^2 \frac{d^2y}{dx^2} + x \frac{dy}{dx} y(x) + (x^2-n^2) y(x) + + if `n` is integer then the solution is of the form ``Eq(f(x), C0 besselj(n,x) + + C1 bessely(n,x))`` as both the solutions are linearly independent else if + `n` is a fraction then the solution is of the form ``Eq(f(x), C0 besselj(n,x) + + C1 besselj(-n,x))`` which can also transform into ``Eq(f(x), C0 besselj(n,x) + + C1 bessely(n,x))``. + + Examples + ======== + + >>> from sympy.abc import x + >>> from sympy import Symbol + >>> v = Symbol('v', positive=True) + >>> from sympy import dsolve, Function + >>> f = Function('f') + >>> y = f(x) + >>> genform = x**2*y.diff(x, 2) + x*y.diff(x) + (x**2 - v**2)*y + >>> dsolve(genform) + Eq(f(x), C1*besselj(v, x) + C2*bessely(v, x)) + + References + ========== + + https://math24.net/bessel-differential-equation.html + + """ + hint = "2nd_linear_bessel" + has_integral = False + + def _matches(self): + eq = self.ode_problem.eq_high_order_free + f = self.ode_problem.func + order = self.ode_problem.order + x = self.ode_problem.sym + df = f.diff(x) + a = Wild('a', exclude=[f,df]) + b = Wild('b', exclude=[x, f,df]) + a4 = Wild('a4', exclude=[x,f,df]) + b4 = Wild('b4', exclude=[x,f,df]) + c4 = Wild('c4', exclude=[x,f,df]) + d4 = Wild('d4', exclude=[x,f,df]) + a3 = Wild('a3', exclude=[f, df, f.diff(x, 2)]) + b3 = Wild('b3', exclude=[f, df, f.diff(x, 2)]) + c3 = Wild('c3', exclude=[f, df, f.diff(x, 2)]) + deq = a3*(f.diff(x, 2)) + b3*df + c3*f + r = collect(eq, + [f.diff(x, 2), df, f]).match(deq) + if order == 2 and r: + if not all(r[key].is_polynomial() for key in r): + n, d = eq.as_numer_denom() + eq = expand(n) + r = collect(eq, + [f.diff(x, 2), df, f]).match(deq) + + if r and r[a3] != 0: + # leading coeff of f(x).diff(x, 2) + coeff = factor(r[a3]).match(a4*(x-b)**b4) + + if coeff: + # if coeff[b4] = 0 means constant coefficient + if coeff[b4] == 0: + return False + point = coeff[b] + else: + return False + + if point: + r[a3] = simplify(r[a3].subs(x, x+point)) + r[b3] = simplify(r[b3].subs(x, x+point)) + r[c3] = simplify(r[c3].subs(x, x+point)) + + # making a3 in the form of x**2 + r[a3] = cancel(r[a3]/(coeff[a4]*(x)**(-2+coeff[b4]))) + r[b3] = cancel(r[b3]/(coeff[a4]*(x)**(-2+coeff[b4]))) + r[c3] = cancel(r[c3]/(coeff[a4]*(x)**(-2+coeff[b4]))) + # checking if b3 is of form c*(x-b) + coeff1 = factor(r[b3]).match(a4*(x)) + if coeff1 is None: + return False + # c3 maybe of very complex form so I am simply checking (a - b) form + # if yes later I will match with the standard form of bessel in a and b + # a, b are wild variable defined above. + _coeff2 = expand(r[c3]).match(a - b) + if _coeff2 is None: + return False + # matching with standard form for c3 + coeff2 = factor(_coeff2[a]).match(c4**2*(x)**(2*a4)) + if coeff2 is None: + return False + + if _coeff2[b] == 0: + coeff2[d4] = 0 + else: + coeff2[d4] = factor(_coeff2[b]).match(d4**2)[d4] + + self.rn = {'n':coeff2[d4], 'a4':coeff2[c4], 'd4':coeff2[a4]} + self.rn['c4'] = coeff1[a4] + self.rn['b4'] = point + return True + return False + + def _get_general_solution(self, *, simplify_flag: bool = True): + f = self.ode_problem.func.func + x = self.ode_problem.sym + n = self.rn['n'] + a4 = self.rn['a4'] + c4 = self.rn['c4'] + d4 = self.rn['d4'] + b4 = self.rn['b4'] + n = sqrt(n**2 + Rational(1, 4)*(c4 - 1)**2) + (C1, C2) = self.ode_problem.get_numbered_constants(num=2) + return [Eq(f(x), ((x**(Rational(1-c4,2)))*(C1*besselj(n/d4,a4*x**d4/d4) + + C2*bessely(n/d4,a4*x**d4/d4))).subs(x, x-b4))] + + +class SecondLinearAiry(SingleODESolver): + r""" + Gives solution of the Airy differential equation + + .. math :: \frac{d^2y}{dx^2} + (a + b x) y(x) = 0 + + in terms of Airy special functions airyai and airybi. + + Examples + ======== + + >>> from sympy import dsolve, Function + >>> from sympy.abc import x + >>> f = Function("f") + >>> eq = f(x).diff(x, 2) - x*f(x) + >>> dsolve(eq) + Eq(f(x), C1*airyai(x) + C2*airybi(x)) + """ + hint = "2nd_linear_airy" + has_integral = False + + def _matches(self): + eq = self.ode_problem.eq_high_order_free + f = self.ode_problem.func + order = self.ode_problem.order + x = self.ode_problem.sym + df = f.diff(x) + a4 = Wild('a4', exclude=[x,f,df]) + b4 = Wild('b4', exclude=[x,f,df]) + match = self.ode_problem.get_linear_coefficients(eq, f, order) + does_match = False + if order == 2 and match and match[2] != 0: + if match[1].is_zero: + self.rn = cancel(match[0]/match[2]).match(a4+b4*x) + if self.rn and self.rn[b4] != 0: + self.rn = {'b':self.rn[a4],'m':self.rn[b4]} + does_match = True + return does_match + + def _get_general_solution(self, *, simplify_flag: bool = True): + f = self.ode_problem.func.func + x = self.ode_problem.sym + (C1, C2) = self.ode_problem.get_numbered_constants(num=2) + b = self.rn['b'] + m = self.rn['m'] + if m.is_positive: + arg = - b/cbrt(m)**2 - cbrt(m)*x + elif m.is_negative: + arg = - b/cbrt(-m)**2 + cbrt(-m)*x + else: + arg = - b/cbrt(-m)**2 + cbrt(-m)*x + + return [Eq(f(x), C1*airyai(arg) + C2*airybi(arg))] + + +class LieGroup(SingleODESolver): + r""" + This hint implements the Lie group method of solving first order differential + equations. The aim is to convert the given differential equation from the + given coordinate system into another coordinate system where it becomes + invariant under the one-parameter Lie group of translations. The converted + ODE can be easily solved by quadrature. It makes use of the + :py:meth:`sympy.solvers.ode.infinitesimals` function which returns the + infinitesimals of the transformation. + + The coordinates `r` and `s` can be found by solving the following Partial + Differential Equations. + + .. math :: \xi\frac{\partial r}{\partial x} + \eta\frac{\partial r}{\partial y} + = 0 + + .. math :: \xi\frac{\partial s}{\partial x} + \eta\frac{\partial s}{\partial y} + = 1 + + The differential equation becomes separable in the new coordinate system + + .. math :: \frac{ds}{dr} = \frac{\frac{\partial s}{\partial x} + + h(x, y)\frac{\partial s}{\partial y}}{ + \frac{\partial r}{\partial x} + h(x, y)\frac{\partial r}{\partial y}} + + After finding the solution by integration, it is then converted back to the original + coordinate system by substituting `r` and `s` in terms of `x` and `y` again. + + Examples + ======== + + >>> from sympy import Function, dsolve, exp, pprint + >>> from sympy.abc import x + >>> f = Function('f') + >>> pprint(dsolve(f(x).diff(x) + 2*x*f(x) - x*exp(-x**2), f(x), + ... hint='lie_group')) + / 2\ 2 + | x | -x + f(x) = |C1 + --|*e + \ 2 / + + + References + ========== + + - Solving differential equations by Symmetry Groups, + John Starrett, pp. 1 - pp. 14 + + """ + hint = "lie_group" + has_integral = False + + def _has_additional_params(self): + return 'xi' in self.ode_problem.params and 'eta' in self.ode_problem.params + + def _matches(self): + eq = self.ode_problem.eq + f = self.ode_problem.func.func + order = self.ode_problem.order + x = self.ode_problem.sym + df = f(x).diff(x) + y = Dummy('y') + d = Wild('d', exclude=[df, f(x).diff(x, 2)]) + e = Wild('e', exclude=[df]) + does_match = False + if self._has_additional_params() and order == 1: + xi = self.ode_problem.params['xi'] + eta = self.ode_problem.params['eta'] + self.r3 = {'xi': xi, 'eta': eta} + r = collect(eq, df, exact=True).match(d + e * df) + if r: + r['d'] = d + r['e'] = e + r['y'] = y + r[d] = r[d].subs(f(x), y) + r[e] = r[e].subs(f(x), y) + self.r3.update(r) + does_match = True + return does_match + + def _get_general_solution(self, *, simplify_flag: bool = True): + eq = self.ode_problem.eq + x = self.ode_problem.sym + func = self.ode_problem.func + order = self.ode_problem.order + df = func.diff(x) + + try: + eqsol = solve(eq, df) + except NotImplementedError: + eqsol = [] + + desols = [] + for s in eqsol: + sol = _ode_lie_group(s, func, order, match=self.r3) + if sol: + desols.extend(sol) + + if desols == []: + raise NotImplementedError("The given ODE " + str(eq) + " cannot be solved by" + + " the lie group method") + return desols + + +solver_map = { + 'factorable': Factorable, + 'nth_linear_constant_coeff_homogeneous': NthLinearConstantCoeffHomogeneous, + 'nth_linear_euler_eq_homogeneous': NthLinearEulerEqHomogeneous, + 'nth_linear_constant_coeff_undetermined_coefficients': NthLinearConstantCoeffUndeterminedCoefficients, + 'nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients': NthLinearEulerEqNonhomogeneousUndeterminedCoefficients, + 'separable': Separable, + '1st_exact': FirstExact, + '1st_linear': FirstLinear, + 'Bernoulli': Bernoulli, + 'Riccati_special_minus2': RiccatiSpecial, + '1st_rational_riccati': RationalRiccati, + '1st_homogeneous_coeff_best': HomogeneousCoeffBest, + '1st_homogeneous_coeff_subs_indep_div_dep': HomogeneousCoeffSubsIndepDivDep, + '1st_homogeneous_coeff_subs_dep_div_indep': HomogeneousCoeffSubsDepDivIndep, + 'almost_linear': AlmostLinear, + 'linear_coefficients': LinearCoefficients, + 'separable_reduced': SeparableReduced, + 'nth_linear_constant_coeff_variation_of_parameters': NthLinearConstantCoeffVariationOfParameters, + 'nth_linear_euler_eq_nonhomogeneous_variation_of_parameters': NthLinearEulerEqNonhomogeneousVariationOfParameters, + 'Liouville': Liouville, + '2nd_linear_airy': SecondLinearAiry, + '2nd_linear_bessel': SecondLinearBessel, + '2nd_hypergeometric': SecondHypergeometric, + 'nth_order_reducible': NthOrderReducible, + '2nd_nonlinear_autonomous_conserved': SecondNonlinearAutonomousConserved, + 'nth_algebraic': NthAlgebraic, + 'lie_group': LieGroup, + } + +# Avoid circular import: +from .ode import dsolve, ode_sol_simplicity, odesimp, homogeneous_order diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/subscheck.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/subscheck.py new file mode 100644 index 0000000000000000000000000000000000000000..6ac7fba7d364bf599e928ccf591b5bef096576d0 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/subscheck.py @@ -0,0 +1,392 @@ +from sympy.core import S, Pow +from sympy.core.function import (Derivative, AppliedUndef, diff) +from sympy.core.relational import Equality, Eq +from sympy.core.symbol import Dummy +from sympy.core.sympify import sympify + +from sympy.logic.boolalg import BooleanAtom +from sympy.functions import exp +from sympy.series import Order +from sympy.simplify.simplify import simplify, posify, besselsimp +from sympy.simplify.trigsimp import trigsimp +from sympy.simplify.sqrtdenest import sqrtdenest +from sympy.solvers import solve +from sympy.solvers.deutils import _preprocess, ode_order +from sympy.utilities.iterables import iterable, is_sequence + + +def sub_func_doit(eq, func, new): + r""" + When replacing the func with something else, we usually want the + derivative evaluated, so this function helps in making that happen. + + Examples + ======== + + >>> from sympy import Derivative, symbols, Function + >>> from sympy.solvers.ode.subscheck import sub_func_doit + >>> x, z = symbols('x, z') + >>> y = Function('y') + + >>> sub_func_doit(3*Derivative(y(x), x) - 1, y(x), x) + 2 + + >>> sub_func_doit(x*Derivative(y(x), x) - y(x)**2 + y(x), y(x), + ... 1/(x*(z + 1/x))) + x*(-1/(x**2*(z + 1/x)) + 1/(x**3*(z + 1/x)**2)) + 1/(x*(z + 1/x)) + ...- 1/(x**2*(z + 1/x)**2) + """ + reps= {func: new} + for d in eq.atoms(Derivative): + if d.expr == func: + reps[d] = new.diff(*d.variable_count) + else: + reps[d] = d.xreplace({func: new}).doit(deep=False) + return eq.xreplace(reps) + + +def checkodesol(ode, sol, func=None, order='auto', solve_for_func=True): + r""" + Substitutes ``sol`` into ``ode`` and checks that the result is ``0``. + + This works when ``func`` is one function, like `f(x)` or a list of + functions like `[f(x), g(x)]` when `ode` is a system of ODEs. ``sol`` can + be a single solution or a list of solutions. Each solution may be an + :py:class:`~sympy.core.relational.Equality` that the solution satisfies, + e.g. ``Eq(f(x), C1), Eq(f(x) + C1, 0)``; or simply an + :py:class:`~sympy.core.expr.Expr`, e.g. ``f(x) - C1``. In most cases it + will not be necessary to explicitly identify the function, but if the + function cannot be inferred from the original equation it can be supplied + through the ``func`` argument. + + If a sequence of solutions is passed, the same sort of container will be + used to return the result for each solution. + + It tries the following methods, in order, until it finds zero equivalence: + + 1. Substitute the solution for `f` in the original equation. This only + works if ``ode`` is solved for `f`. It will attempt to solve it first + unless ``solve_for_func == False``. + 2. Take `n` derivatives of the solution, where `n` is the order of + ``ode``, and check to see if that is equal to the solution. This only + works on exact ODEs. + 3. Take the 1st, 2nd, ..., `n`\th derivatives of the solution, each time + solving for the derivative of `f` of that order (this will always be + possible because `f` is a linear operator). Then back substitute each + derivative into ``ode`` in reverse order. + + This function returns a tuple. The first item in the tuple is ``True`` if + the substitution results in ``0``, and ``False`` otherwise. The second + item in the tuple is what the substitution results in. It should always + be ``0`` if the first item is ``True``. Sometimes this function will + return ``False`` even when an expression is identically equal to ``0``. + This happens when :py:meth:`~sympy.simplify.simplify.simplify` does not + reduce the expression to ``0``. If an expression returned by this + function vanishes identically, then ``sol`` really is a solution to + the ``ode``. + + If this function seems to hang, it is probably because of a hard + simplification. + + To use this function to test, test the first item of the tuple. + + Examples + ======== + + >>> from sympy import (Eq, Function, checkodesol, symbols, + ... Derivative, exp) + >>> x, C1, C2 = symbols('x,C1,C2') + >>> f, g = symbols('f g', cls=Function) + >>> checkodesol(f(x).diff(x), Eq(f(x), C1)) + (True, 0) + >>> assert checkodesol(f(x).diff(x), C1)[0] + >>> assert not checkodesol(f(x).diff(x), x)[0] + >>> checkodesol(f(x).diff(x, 2), x**2) + (False, 2) + + >>> eqs = [Eq(Derivative(f(x), x), f(x)), Eq(Derivative(g(x), x), g(x))] + >>> sol = [Eq(f(x), C1*exp(x)), Eq(g(x), C2*exp(x))] + >>> checkodesol(eqs, sol) + (True, [0, 0]) + + """ + if iterable(ode): + return checksysodesol(ode, sol, func=func) + + if not isinstance(ode, Equality): + ode = Eq(ode, 0) + if func is None: + try: + _, func = _preprocess(ode.lhs) + except ValueError: + funcs = [s.atoms(AppliedUndef) for s in ( + sol if is_sequence(sol, set) else [sol])] + funcs = set().union(*funcs) + if len(funcs) != 1: + raise ValueError( + 'must pass func arg to checkodesol for this case.') + func = funcs.pop() + if not isinstance(func, AppliedUndef) or len(func.args) != 1: + raise ValueError( + "func must be a function of one variable, not %s" % func) + if is_sequence(sol, set): + return type(sol)([checkodesol(ode, i, order=order, solve_for_func=solve_for_func) for i in sol]) + + if not isinstance(sol, Equality): + sol = Eq(func, sol) + elif sol.rhs == func: + sol = sol.reversed + + if order == 'auto': + order = ode_order(ode, func) + solved = sol.lhs == func and not sol.rhs.has(func) + if solve_for_func and not solved: + rhs = solve(sol, func) + if rhs: + eqs = [Eq(func, t) for t in rhs] + if len(rhs) == 1: + eqs = eqs[0] + return checkodesol(ode, eqs, order=order, + solve_for_func=False) + + x = func.args[0] + + # Handle series solutions here + if sol.has(Order): + assert sol.lhs == func + Oterm = sol.rhs.getO() + solrhs = sol.rhs.removeO() + + Oexpr = Oterm.expr + assert isinstance(Oexpr, Pow) + sorder = Oexpr.exp + assert Oterm == Order(x**sorder) + + odesubs = (ode.lhs-ode.rhs).subs(func, solrhs).doit().expand() + + neworder = Order(x**(sorder - order)) + odesubs = odesubs + neworder + assert odesubs.getO() == neworder + residual = odesubs.removeO() + + return (residual == 0, residual) + + s = True + testnum = 0 + while s: + if testnum == 0: + # First pass, try substituting a solved solution directly into the + # ODE. This has the highest chance of succeeding. + ode_diff = ode.lhs - ode.rhs + + if sol.lhs == func: + s = sub_func_doit(ode_diff, func, sol.rhs) + s = besselsimp(s) + else: + testnum += 1 + continue + ss = simplify(s.rewrite(exp)) + if ss: + # with the new numer_denom in power.py, if we do a simple + # expansion then testnum == 0 verifies all solutions. + s = ss.expand(force=True) + else: + s = 0 + testnum += 1 + elif testnum == 1: + # Second pass. If we cannot substitute f, try seeing if the nth + # derivative is equal, this will only work for odes that are exact, + # by definition. + s = simplify( + trigsimp(diff(sol.lhs, x, order) - diff(sol.rhs, x, order)) - + trigsimp(ode.lhs) + trigsimp(ode.rhs)) + # s2 = simplify( + # diff(sol.lhs, x, order) - diff(sol.rhs, x, order) - \ + # ode.lhs + ode.rhs) + testnum += 1 + elif testnum == 2: + # Third pass. Try solving for df/dx and substituting that into the + # ODE. Thanks to Chris Smith for suggesting this method. Many of + # the comments below are his, too. + # The method: + # - Take each of 1..n derivatives of the solution. + # - Solve each nth derivative for d^(n)f/dx^(n) + # (the differential of that order) + # - Back substitute into the ODE in decreasing order + # (i.e., n, n-1, ...) + # - Check the result for zero equivalence + if sol.lhs == func and not sol.rhs.has(func): + diffsols = {0: sol.rhs} + elif sol.rhs == func and not sol.lhs.has(func): + diffsols = {0: sol.lhs} + else: + diffsols = {} + sol = sol.lhs - sol.rhs + for i in range(1, order + 1): + # Differentiation is a linear operator, so there should always + # be 1 solution. Nonetheless, we test just to make sure. + # We only need to solve once. After that, we automatically + # have the solution to the differential in the order we want. + if i == 1: + ds = sol.diff(x) + try: + sdf = solve(ds, func.diff(x, i)) + if not sdf: + raise NotImplementedError + except NotImplementedError: + testnum += 1 + break + else: + diffsols[i] = sdf[0] + else: + # This is what the solution says df/dx should be. + diffsols[i] = diffsols[i - 1].diff(x) + + # Make sure the above didn't fail. + if testnum > 2: + continue + else: + # Substitute it into ODE to check for self consistency. + lhs, rhs = ode.lhs, ode.rhs + for i in range(order, -1, -1): + if i == 0 and 0 not in diffsols: + # We can only substitute f(x) if the solution was + # solved for f(x). + break + lhs = sub_func_doit(lhs, func.diff(x, i), diffsols[i]) + rhs = sub_func_doit(rhs, func.diff(x, i), diffsols[i]) + ode_or_bool = Eq(lhs, rhs) + ode_or_bool = simplify(ode_or_bool) + + if isinstance(ode_or_bool, (bool, BooleanAtom)): + if ode_or_bool: + lhs = rhs = S.Zero + else: + lhs = ode_or_bool.lhs + rhs = ode_or_bool.rhs + # No sense in overworking simplify -- just prove that the + # numerator goes to zero + num = trigsimp((lhs - rhs).as_numer_denom()[0]) + # since solutions are obtained using force=True we test + # using the same level of assumptions + ## replace function with dummy so assumptions will work + _func = Dummy('func') + num = num.subs(func, _func) + ## posify the expression + num, reps = posify(num) + s = simplify(num).xreplace(reps).xreplace({_func: func}) + testnum += 1 + else: + break + + if not s: + return (True, s) + elif s is True: # The code above never was able to change s + raise NotImplementedError("Unable to test if " + str(sol) + + " is a solution to " + str(ode) + ".") + else: + return (False, s) + + +def checksysodesol(eqs, sols, func=None): + r""" + Substitutes corresponding ``sols`` for each functions into each ``eqs`` and + checks that the result of substitutions for each equation is ``0``. The + equations and solutions passed can be any iterable. + + This only works when each ``sols`` have one function only, like `x(t)` or `y(t)`. + For each function, ``sols`` can have a single solution or a list of solutions. + In most cases it will not be necessary to explicitly identify the function, + but if the function cannot be inferred from the original equation it + can be supplied through the ``func`` argument. + + When a sequence of equations is passed, the same sequence is used to return + the result for each equation with each function substituted with corresponding + solutions. + + It tries the following method to find zero equivalence for each equation: + + Substitute the solutions for functions, like `x(t)` and `y(t)` into the + original equations containing those functions. + This function returns a tuple. The first item in the tuple is ``True`` if + the substitution results for each equation is ``0``, and ``False`` otherwise. + The second item in the tuple is what the substitution results in. Each element + of the ``list`` should always be ``0`` corresponding to each equation if the + first item is ``True``. Note that sometimes this function may return ``False``, + but with an expression that is identically equal to ``0``, instead of returning + ``True``. This is because :py:meth:`~sympy.simplify.simplify.simplify` cannot + reduce the expression to ``0``. If an expression returned by each function + vanishes identically, then ``sols`` really is a solution to ``eqs``. + + If this function seems to hang, it is probably because of a difficult simplification. + + Examples + ======== + + >>> from sympy import Eq, diff, symbols, sin, cos, exp, sqrt, S, Function + >>> from sympy.solvers.ode.subscheck import checksysodesol + >>> C1, C2 = symbols('C1:3') + >>> t = symbols('t') + >>> x, y = symbols('x, y', cls=Function) + >>> eq = (Eq(diff(x(t),t), x(t) + y(t) + 17), Eq(diff(y(t),t), -2*x(t) + y(t) + 12)) + >>> sol = [Eq(x(t), (C1*sin(sqrt(2)*t) + C2*cos(sqrt(2)*t))*exp(t) - S(5)/3), + ... Eq(y(t), (sqrt(2)*C1*cos(sqrt(2)*t) - sqrt(2)*C2*sin(sqrt(2)*t))*exp(t) - S(46)/3)] + >>> checksysodesol(eq, sol) + (True, [0, 0]) + >>> eq = (Eq(diff(x(t),t),x(t)*y(t)**4), Eq(diff(y(t),t),y(t)**3)) + >>> sol = [Eq(x(t), C1*exp(-1/(4*(C2 + t)))), Eq(y(t), -sqrt(2)*sqrt(-1/(C2 + t))/2), + ... Eq(x(t), C1*exp(-1/(4*(C2 + t)))), Eq(y(t), sqrt(2)*sqrt(-1/(C2 + t))/2)] + >>> checksysodesol(eq, sol) + (True, [0, 0]) + + """ + def _sympify(eq): + return list(map(sympify, eq if iterable(eq) else [eq])) + eqs = _sympify(eqs) + for i in range(len(eqs)): + if isinstance(eqs[i], Equality): + eqs[i] = eqs[i].lhs - eqs[i].rhs + if func is None: + funcs = [] + for eq in eqs: + derivs = eq.atoms(Derivative) + func = set().union(*[d.atoms(AppliedUndef) for d in derivs]) + funcs.extend(func) + funcs = list(set(funcs)) + if not all(isinstance(func, AppliedUndef) and len(func.args) == 1 for func in funcs)\ + and len({func.args for func in funcs})!=1: + raise ValueError("func must be a function of one variable, not %s" % func) + for sol in sols: + if len(sol.atoms(AppliedUndef)) != 1: + raise ValueError("solutions should have one function only") + if len(funcs) != len({sol.lhs for sol in sols}): + raise ValueError("number of solutions provided does not match the number of equations") + dictsol = {} + for sol in sols: + func = list(sol.atoms(AppliedUndef))[0] + if sol.rhs == func: + sol = sol.reversed + solved = sol.lhs == func and not sol.rhs.has(func) + if not solved: + rhs = solve(sol, func) + if not rhs: + raise NotImplementedError + else: + rhs = sol.rhs + dictsol[func] = rhs + checkeq = [] + for eq in eqs: + for func in funcs: + eq = sub_func_doit(eq, func, dictsol[func]) + ss = simplify(eq) + if ss != 0: + eq = ss.expand(force=True) + if eq != 0: + eq = sqrtdenest(eq).simplify() + else: + eq = 0 + checkeq.append(eq) + if len(set(checkeq)) == 1 and list(set(checkeq))[0] == 0: + return (True, checkeq) + else: + return (False, checkeq) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/systems.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/systems.py new file mode 100644 index 0000000000000000000000000000000000000000..2d2c9b57a969c7fb5c67c06ce952fa398e22a48d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/systems.py @@ -0,0 +1,2135 @@ +from sympy.core import Add, Mul, S +from sympy.core.containers import Tuple +from sympy.core.exprtools import factor_terms +from sympy.core.numbers import I +from sympy.core.relational import Eq, Equality +from sympy.core.sorting import default_sort_key, ordered +from sympy.core.symbol import Dummy, Symbol +from sympy.core.function import (expand_mul, expand, Derivative, + AppliedUndef, Function, Subs) +from sympy.functions import (exp, im, cos, sin, re, Piecewise, + piecewise_fold, sqrt, log) +from sympy.functions.combinatorial.factorials import factorial +from sympy.matrices import zeros, Matrix, NonSquareMatrixError, MatrixBase, eye +from sympy.polys import Poly, together +from sympy.simplify import collect, radsimp, signsimp # type: ignore +from sympy.simplify.powsimp import powdenest, powsimp +from sympy.simplify.ratsimp import ratsimp +from sympy.simplify.simplify import simplify +from sympy.sets.sets import FiniteSet +from sympy.solvers.deutils import ode_order +from sympy.solvers.solveset import NonlinearError, solveset +from sympy.utilities.iterables import (connected_components, iterable, + strongly_connected_components) +from sympy.utilities.misc import filldedent +from sympy.integrals.integrals import Integral, integrate + + +def _get_func_order(eqs, funcs): + return {func: max(ode_order(eq, func) for eq in eqs) for func in funcs} + + +class ODEOrderError(ValueError): + """Raised by linear_ode_to_matrix if the system has the wrong order""" + pass + + +class ODENonlinearError(NonlinearError): + """Raised by linear_ode_to_matrix if the system is nonlinear""" + pass + + +def _simpsol(soleq): + lhs = soleq.lhs + sol = soleq.rhs + sol = powsimp(sol) + gens = list(sol.atoms(exp)) + p = Poly(sol, *gens, expand=False) + gens = [factor_terms(g) for g in gens] + if not gens: + gens = p.gens + syms = [Symbol('C1'), Symbol('C2')] + terms = [] + for coeff, monom in zip(p.coeffs(), p.monoms()): + coeff = piecewise_fold(coeff) + if isinstance(coeff, Piecewise): + coeff = Piecewise(*((ratsimp(coef).collect(syms), cond) for coef, cond in coeff.args)) + else: + coeff = ratsimp(coeff).collect(syms) + monom = Mul(*(g ** i for g, i in zip(gens, monom))) + terms.append(coeff * monom) + return Eq(lhs, Add(*terms)) + + +def _solsimp(e, t): + no_t, has_t = powsimp(expand_mul(e)).as_independent(t) + + no_t = ratsimp(no_t) + has_t = has_t.replace(exp, lambda a: exp(factor_terms(a))) + + return no_t + has_t + + +def simpsol(sol, wrt1, wrt2, doit=True): + """Simplify solutions from dsolve_system.""" + + # The parameter sol is the solution as returned by dsolve (list of Eq). + # + # The parameters wrt1 and wrt2 are lists of symbols to be collected for + # with those in wrt1 being collected for first. This allows for collecting + # on any factors involving the independent variable before collecting on + # the integration constants or vice versa using e.g.: + # + # sol = simpsol(sol, [t], [C1, C2]) # t first, constants after + # sol = simpsol(sol, [C1, C2], [t]) # constants first, t after + # + # If doit=True (default) then simpsol will begin by evaluating any + # unevaluated integrals. Since many integrals will appear multiple times + # in the solutions this is done intelligently by computing each integral + # only once. + # + # The strategy is to first perform simple cancellation with factor_terms + # and then multiply out all brackets with expand_mul. This gives an Add + # with many terms. + # + # We split each term into two multiplicative factors dep and coeff where + # all factors that involve wrt1 are in dep and any constant factors are in + # coeff e.g. + # sqrt(2)*C1*exp(t) -> ( exp(t), sqrt(2)*C1 ) + # + # The dep factors are simplified using powsimp to combine expanded + # exponential factors e.g. + # exp(a*t)*exp(b*t) -> exp(t*(a+b)) + # + # We then collect coefficients for all terms having the same (simplified) + # dep. The coefficients are then simplified using together and ratsimp and + # lastly by recursively applying the same transformation to the + # coefficients to collect on wrt2. + # + # Finally the result is recombined into an Add and signsimp is used to + # normalise any minus signs. + + def simprhs(rhs, rep, wrt1, wrt2): + """Simplify the rhs of an ODE solution""" + if rep: + rhs = rhs.subs(rep) + rhs = factor_terms(rhs) + rhs = simp_coeff_dep(rhs, wrt1, wrt2) + rhs = signsimp(rhs) + return rhs + + def simp_coeff_dep(expr, wrt1, wrt2=None): + """Split rhs into terms, split terms into dep and coeff and collect on dep""" + add_dep_terms = lambda e: e.is_Add and e.has(*wrt1) + expandable = lambda e: e.is_Mul and any(map(add_dep_terms, e.args)) + expand_func = lambda e: expand_mul(e, deep=False) + expand_mul_mod = lambda e: e.replace(expandable, expand_func) + terms = Add.make_args(expand_mul_mod(expr)) + dc = {} + for term in terms: + coeff, dep = term.as_independent(*wrt1, as_Add=False) + # Collect together the coefficients for terms that have the same + # dependence on wrt1 (after dep is normalised using simpdep). + dep = simpdep(dep, wrt1) + + # See if the dependence on t cancels out... + if dep is not S.One: + dep2 = factor_terms(dep) + if not dep2.has(*wrt1): + coeff *= dep2 + dep = S.One + + if dep not in dc: + dc[dep] = coeff + else: + dc[dep] += coeff + # Apply the method recursively to the coefficients but this time + # collecting on wrt2 rather than wrt2. + termpairs = ((simpcoeff(c, wrt2), d) for d, c in dc.items()) + if wrt2 is not None: + termpairs = ((simp_coeff_dep(c, wrt2), d) for c, d in termpairs) + return Add(*(c * d for c, d in termpairs)) + + def simpdep(term, wrt1): + """Normalise factors involving t with powsimp and recombine exp""" + def canonicalise(a): + # Using factor_terms here isn't quite right because it leads to things + # like exp(t*(1+t)) that we don't want. We do want to cancel factors + # and pull out a common denominator but ideally the numerator would be + # expressed as a standard form polynomial in t so we expand_mul + # and collect afterwards. + a = factor_terms(a) + num, den = a.as_numer_denom() + num = expand_mul(num) + num = collect(num, wrt1) + return num / den + + term = powsimp(term) + rep = {e: exp(canonicalise(e.args[0])) for e in term.atoms(exp)} + term = term.subs(rep) + return term + + def simpcoeff(coeff, wrt2): + """Bring to a common fraction and cancel with ratsimp""" + coeff = together(coeff) + if coeff.is_polynomial(): + # Calling ratsimp can be expensive. The main reason is to simplify + # sums of terms with irrational denominators so we limit ourselves + # to the case where the expression is polynomial in any symbols. + # Maybe there's a better approach... + coeff = ratsimp(radsimp(coeff)) + # collect on secondary variables first and any remaining symbols after + if wrt2 is not None: + syms = list(wrt2) + list(ordered(coeff.free_symbols - set(wrt2))) + else: + syms = list(ordered(coeff.free_symbols)) + coeff = collect(coeff, syms) + coeff = together(coeff) + return coeff + + # There are often repeated integrals. Collect unique integrals and + # evaluate each once and then substitute into the final result to replace + # all occurrences in each of the solution equations. + if doit: + integrals = set().union(*(s.atoms(Integral) for s in sol)) + rep = {i: factor_terms(i).doit() for i in integrals} + else: + rep = {} + + sol = [Eq(s.lhs, simprhs(s.rhs, rep, wrt1, wrt2)) for s in sol] + return sol + + +def linodesolve_type(A, t, b=None): + r""" + Helper function that determines the type of the system of ODEs for solving with :obj:`sympy.solvers.ode.systems.linodesolve()` + + Explanation + =========== + + This function takes in the coefficient matrix and/or the non-homogeneous term + and returns the type of the equation that can be solved by :obj:`sympy.solvers.ode.systems.linodesolve()`. + + If the system is constant coefficient homogeneous, then "type1" is returned + + If the system is constant coefficient non-homogeneous, then "type2" is returned + + If the system is non-constant coefficient homogeneous, then "type3" is returned + + If the system is non-constant coefficient non-homogeneous, then "type4" is returned + + If the system has a non-constant coefficient matrix which can be factorized into constant + coefficient matrix, then "type5" or "type6" is returned for when the system is homogeneous or + non-homogeneous respectively. + + Note that, if the system of ODEs is of "type3" or "type4", then along with the type, + the commutative antiderivative of the coefficient matrix is also returned. + + If the system cannot be solved by :obj:`sympy.solvers.ode.systems.linodesolve()`, then + NotImplementedError is raised. + + Parameters + ========== + + A : Matrix + Coefficient matrix of the system of ODEs + b : Matrix or None + Non-homogeneous term of the system. The default value is None. + If this argument is None, then the system is assumed to be homogeneous. + + Examples + ======== + + >>> from sympy import symbols, Matrix + >>> from sympy.solvers.ode.systems import linodesolve_type + >>> t = symbols("t") + >>> A = Matrix([[1, 1], [2, 3]]) + >>> b = Matrix([t, 1]) + + >>> linodesolve_type(A, t) + {'antiderivative': None, 'type_of_equation': 'type1'} + + >>> linodesolve_type(A, t, b=b) + {'antiderivative': None, 'type_of_equation': 'type2'} + + >>> A_t = Matrix([[1, t], [-t, 1]]) + + >>> linodesolve_type(A_t, t) + {'antiderivative': Matrix([ + [ t, t**2/2], + [-t**2/2, t]]), 'type_of_equation': 'type3'} + + >>> linodesolve_type(A_t, t, b=b) + {'antiderivative': Matrix([ + [ t, t**2/2], + [-t**2/2, t]]), 'type_of_equation': 'type4'} + + >>> A_non_commutative = Matrix([[1, t], [t, -1]]) + >>> linodesolve_type(A_non_commutative, t) + Traceback (most recent call last): + ... + NotImplementedError: + The system does not have a commutative antiderivative, it cannot be + solved by linodesolve. + + Returns + ======= + + Dict + + Raises + ====== + + NotImplementedError + When the coefficient matrix does not have a commutative antiderivative + + See Also + ======== + + linodesolve: Function for which linodesolve_type gets the information + + """ + + match = {} + is_non_constant = not _matrix_is_constant(A, t) + is_non_homogeneous = not (b is None or b.is_zero_matrix) + type = "type{}".format(int("{}{}".format(int(is_non_constant), int(is_non_homogeneous)), 2) + 1) + + B = None + match.update({"type_of_equation": type, "antiderivative": B}) + + if is_non_constant: + B, is_commuting = _is_commutative_anti_derivative(A, t) + if not is_commuting: + raise NotImplementedError(filldedent(''' + The system does not have a commutative antiderivative, it cannot be solved + by linodesolve. + ''')) + + match['antiderivative'] = B + match.update(_first_order_type5_6_subs(A, t, b=b)) + + return match + + +def _first_order_type5_6_subs(A, t, b=None): + match = {} + + factor_terms = _factor_matrix(A, t) + is_homogeneous = b is None or b.is_zero_matrix + + if factor_terms is not None: + t_ = Symbol("{}_".format(t)) + F_t = integrate(factor_terms[0], t) + inverse = solveset(Eq(t_, F_t), t) + + # Note: A simple way to check if a function is invertible + # or not. + if isinstance(inverse, FiniteSet) and not inverse.has(Piecewise)\ + and len(inverse) == 1: + + A = factor_terms[1] + if not is_homogeneous: + b = b / factor_terms[0] + b = b.subs(t, list(inverse)[0]) + type = "type{}".format(5 + (not is_homogeneous)) + match.update({'func_coeff': A, 'tau': F_t, + 't_': t_, 'type_of_equation': type, 'rhs': b}) + + return match + + +def linear_ode_to_matrix(eqs, funcs, t, order): + r""" + Convert a linear system of ODEs to matrix form + + Explanation + =========== + + Express a system of linear ordinary differential equations as a single + matrix differential equation [1]. For example the system $x' = x + y + 1$ + and $y' = x - y$ can be represented as + + .. math:: A_1 X' = A_0 X + b + + where $A_1$ and $A_0$ are $2 \times 2$ matrices and $b$, $X$ and $X'$ are + $2 \times 1$ matrices with $X = [x, y]^T$. + + Higher-order systems are represented with additional matrices e.g. a + second-order system would look like + + .. math:: A_2 X'' = A_1 X' + A_0 X + b + + Examples + ======== + + >>> from sympy import Function, Symbol, Matrix, Eq + >>> from sympy.solvers.ode.systems import linear_ode_to_matrix + >>> t = Symbol('t') + >>> x = Function('x') + >>> y = Function('y') + + We can create a system of linear ODEs like + + >>> eqs = [ + ... Eq(x(t).diff(t), x(t) + y(t) + 1), + ... Eq(y(t).diff(t), x(t) - y(t)), + ... ] + >>> funcs = [x(t), y(t)] + >>> order = 1 # 1st order system + + Now ``linear_ode_to_matrix`` can represent this as a matrix + differential equation. + + >>> (A1, A0), b = linear_ode_to_matrix(eqs, funcs, t, order) + >>> A1 + Matrix([ + [1, 0], + [0, 1]]) + >>> A0 + Matrix([ + [1, 1], + [1, -1]]) + >>> b + Matrix([ + [1], + [0]]) + + The original equations can be recovered from these matrices: + + >>> eqs_mat = Matrix([eq.lhs - eq.rhs for eq in eqs]) + >>> X = Matrix(funcs) + >>> A1 * X.diff(t) - A0 * X - b == eqs_mat + True + + If the system of equations has a maximum order greater than the + order of the system specified, a ODEOrderError exception is raised. + + >>> eqs = [Eq(x(t).diff(t, 2), x(t).diff(t) + x(t)), Eq(y(t).diff(t), y(t) + x(t))] + >>> linear_ode_to_matrix(eqs, funcs, t, 1) + Traceback (most recent call last): + ... + ODEOrderError: Cannot represent system in 1-order form + + If the system of equations is nonlinear, then ODENonlinearError is + raised. + + >>> eqs = [Eq(x(t).diff(t), x(t) + y(t)), Eq(y(t).diff(t), y(t)**2 + x(t))] + >>> linear_ode_to_matrix(eqs, funcs, t, 1) + Traceback (most recent call last): + ... + ODENonlinearError: The system of ODEs is nonlinear. + + Parameters + ========== + + eqs : list of SymPy expressions or equalities + The equations as expressions (assumed equal to zero). + funcs : list of applied functions + The dependent variables of the system of ODEs. + t : symbol + The independent variable. + order : int + The order of the system of ODEs. + + Returns + ======= + + The tuple ``(As, b)`` where ``As`` is a tuple of matrices and ``b`` is the + the matrix representing the rhs of the matrix equation. + + Raises + ====== + + ODEOrderError + When the system of ODEs have an order greater than what was specified + ODENonlinearError + When the system of ODEs is nonlinear + + See Also + ======== + + linear_eq_to_matrix: for systems of linear algebraic equations. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Matrix_differential_equation + + """ + from sympy.solvers.solveset import linear_eq_to_matrix + + if any(ode_order(eq, func) > order for eq in eqs for func in funcs): + msg = "Cannot represent system in {}-order form" + raise ODEOrderError(msg.format(order)) + + As = [] + + for o in range(order, -1, -1): + # Work from the highest derivative down + syms = [func.diff(t, o) for func in funcs] + + # Ai is the matrix for X(t).diff(t, o) + # eqs is minus the remainder of the equations. + try: + Ai, b = linear_eq_to_matrix(eqs, syms) + except NonlinearError: + raise ODENonlinearError("The system of ODEs is nonlinear.") + + Ai = Ai.applyfunc(expand_mul) + + As.append(Ai if o == order else -Ai) + + if o: + eqs = [-eq for eq in b] + else: + rhs = b + + return As, rhs + + +def matrix_exp(A, t): + r""" + Matrix exponential $\exp(A*t)$ for the matrix ``A`` and scalar ``t``. + + Explanation + =========== + + This functions returns the $\exp(A*t)$ by doing a simple + matrix multiplication: + + .. math:: \exp(A*t) = P * expJ * P^{-1} + + where $expJ$ is $\exp(J*t)$. $J$ is the Jordan normal + form of $A$ and $P$ is matrix such that: + + .. math:: A = P * J * P^{-1} + + The matrix exponential $\exp(A*t)$ appears in the solution of linear + differential equations. For example if $x$ is a vector and $A$ is a matrix + then the initial value problem + + .. math:: \frac{dx(t)}{dt} = A \times x(t), x(0) = x0 + + has the unique solution + + .. math:: x(t) = \exp(A t) x0 + + Examples + ======== + + >>> from sympy import Symbol, Matrix, pprint + >>> from sympy.solvers.ode.systems import matrix_exp + >>> t = Symbol('t') + + We will consider a 2x2 matrix for comupting the exponential + + >>> A = Matrix([[2, -5], [2, -4]]) + >>> pprint(A) + [2 -5] + [ ] + [2 -4] + + Now, exp(A*t) is given as follows: + + >>> pprint(matrix_exp(A, t)) + [ -t -t -t ] + [3*e *sin(t) + e *cos(t) -5*e *sin(t) ] + [ ] + [ -t -t -t ] + [ 2*e *sin(t) - 3*e *sin(t) + e *cos(t)] + + Parameters + ========== + + A : Matrix + The matrix $A$ in the expression $\exp(A*t)$ + t : Symbol + The independent variable + + See Also + ======== + + matrix_exp_jordan_form: For exponential of Jordan normal form + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Jordan_normal_form + .. [2] https://en.wikipedia.org/wiki/Matrix_exponential + + """ + P, expJ = matrix_exp_jordan_form(A, t) + return P * expJ * P.inv() + + +def matrix_exp_jordan_form(A, t): + r""" + Matrix exponential $\exp(A*t)$ for the matrix *A* and scalar *t*. + + Explanation + =========== + + Returns the Jordan form of the $\exp(A*t)$ along with the matrix $P$ such that: + + .. math:: + \exp(A*t) = P * expJ * P^{-1} + + Examples + ======== + + >>> from sympy import Matrix, Symbol + >>> from sympy.solvers.ode.systems import matrix_exp, matrix_exp_jordan_form + >>> t = Symbol('t') + + We will consider a 2x2 defective matrix. This shows that our method + works even for defective matrices. + + >>> A = Matrix([[1, 1], [0, 1]]) + + It can be observed that this function gives us the Jordan normal form + and the required invertible matrix P. + + >>> P, expJ = matrix_exp_jordan_form(A, t) + + Here, it is shown that P and expJ returned by this function is correct + as they satisfy the formula: P * expJ * P_inverse = exp(A*t). + + >>> P * expJ * P.inv() == matrix_exp(A, t) + True + + Parameters + ========== + + A : Matrix + The matrix $A$ in the expression $\exp(A*t)$ + t : Symbol + The independent variable + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Defective_matrix + .. [2] https://en.wikipedia.org/wiki/Jordan_matrix + .. [3] https://en.wikipedia.org/wiki/Jordan_normal_form + + """ + + N, M = A.shape + if N != M: + raise ValueError('Needed square matrix but got shape (%s, %s)' % (N, M)) + elif A.has(t): + raise ValueError('Matrix A should not depend on t') + + def jordan_chains(A): + '''Chains from Jordan normal form analogous to M.eigenvects(). + Returns a dict with eignevalues as keys like: + {e1: [[v111,v112,...], [v121, v122,...]], e2:...} + where vijk is the kth vector in the jth chain for eigenvalue i. + ''' + P, blocks = A.jordan_cells() + basis = [P[:,i] for i in range(P.shape[1])] + n = 0 + chains = {} + for b in blocks: + eigval = b[0, 0] + size = b.shape[0] + if eigval not in chains: + chains[eigval] = [] + chains[eigval].append(basis[n:n+size]) + n += size + return chains + + eigenchains = jordan_chains(A) + + # Needed for consistency across Python versions + eigenchains_iter = sorted(eigenchains.items(), key=default_sort_key) + isreal = not A.has(I) + + blocks = [] + vectors = [] + seen_conjugate = set() + for e, chains in eigenchains_iter: + for chain in chains: + n = len(chain) + if isreal and e != e.conjugate() and e.conjugate() in eigenchains: + if e in seen_conjugate: + continue + seen_conjugate.add(e.conjugate()) + exprt = exp(re(e) * t) + imrt = im(e) * t + imblock = Matrix([[cos(imrt), sin(imrt)], + [-sin(imrt), cos(imrt)]]) + expJblock2 = Matrix(n, n, lambda i,j: + imblock * t**(j-i) / factorial(j-i) if j >= i + else zeros(2, 2)) + expJblock = Matrix(2*n, 2*n, lambda i,j: expJblock2[i//2,j//2][i%2,j%2]) + + blocks.append(exprt * expJblock) + for i in range(n): + vectors.append(re(chain[i])) + vectors.append(im(chain[i])) + else: + vectors.extend(chain) + fun = lambda i,j: t**(j-i)/factorial(j-i) if j >= i else 0 + expJblock = Matrix(n, n, fun) + blocks.append(exp(e * t) * expJblock) + + expJ = Matrix.diag(*blocks) + P = Matrix(N, N, lambda i,j: vectors[j][i]) + + return P, expJ + + +# Note: To add a docstring example with tau +def linodesolve(A, t, b=None, B=None, type="auto", doit=False, + tau=None): + r""" + System of n equations linear first-order differential equations + + Explanation + =========== + + This solver solves the system of ODEs of the following form: + + .. math:: + X'(t) = A(t) X(t) + b(t) + + Here, $A(t)$ is the coefficient matrix, $X(t)$ is the vector of n independent variables, + $b(t)$ is the non-homogeneous term and $X'(t)$ is the derivative of $X(t)$ + + Depending on the properties of $A(t)$ and $b(t)$, this solver evaluates the solution + differently. + + When $A(t)$ is constant coefficient matrix and $b(t)$ is zero vector i.e. system is homogeneous, + the system is "type1". The solution is: + + .. math:: + X(t) = \exp(A t) C + + Here, $C$ is a vector of constants and $A$ is the constant coefficient matrix. + + When $A(t)$ is constant coefficient matrix and $b(t)$ is non-zero i.e. system is non-homogeneous, + the system is "type2". The solution is: + + .. math:: + X(t) = e^{A t} ( \int e^{- A t} b \,dt + C) + + When $A(t)$ is coefficient matrix such that its commutative with its antiderivative $B(t)$ and + $b(t)$ is a zero vector i.e. system is homogeneous, the system is "type3". The solution is: + + .. math:: + X(t) = \exp(B(t)) C + + When $A(t)$ is commutative with its antiderivative $B(t)$ and $b(t)$ is non-zero i.e. system is + non-homogeneous, the system is "type4". The solution is: + + .. math:: + X(t) = e^{B(t)} ( \int e^{-B(t)} b(t) \,dt + C) + + When $A(t)$ is a coefficient matrix such that it can be factorized into a scalar and a constant + coefficient matrix: + + .. math:: + A(t) = f(t) * A + + Where $f(t)$ is a scalar expression in the independent variable $t$ and $A$ is a constant matrix, + then we can do the following substitutions: + + .. math:: + tau = \int f(t) dt, X(t) = Y(tau), b(t) = b(f^{-1}(tau)) + + Here, the substitution for the non-homogeneous term is done only when its non-zero. + Using these substitutions, our original system becomes: + + .. math:: + Y'(tau) = A * Y(tau) + b(tau)/f(tau) + + The above system can be easily solved using the solution for "type1" or "type2" depending + on the homogeneity of the system. After we get the solution for $Y(tau)$, we substitute the + solution for $tau$ as $t$ to get back $X(t)$ + + .. math:: + X(t) = Y(tau) + + Systems of "type5" and "type6" have a commutative antiderivative but we use this solution + because its faster to compute. + + The final solution is the general solution for all the four equations since a constant coefficient + matrix is always commutative with its antidervative. + + An additional feature of this function is, if someone wants to substitute for value of the independent + variable, they can pass the substitution `tau` and the solution will have the independent variable + substituted with the passed expression(`tau`). + + Parameters + ========== + + A : Matrix + Coefficient matrix of the system of linear first order ODEs. + t : Symbol + Independent variable in the system of ODEs. + b : Matrix or None + Non-homogeneous term in the system of ODEs. If None is passed, + a homogeneous system of ODEs is assumed. + B : Matrix or None + Antiderivative of the coefficient matrix. If the antiderivative + is not passed and the solution requires the term, then the solver + would compute it internally. + type : String + Type of the system of ODEs passed. Depending on the type, the + solution is evaluated. The type values allowed and the corresponding + system it solves are: "type1" for constant coefficient homogeneous + "type2" for constant coefficient non-homogeneous, "type3" for non-constant + coefficient homogeneous, "type4" for non-constant coefficient non-homogeneous, + "type5" and "type6" for non-constant coefficient homogeneous and non-homogeneous + systems respectively where the coefficient matrix can be factorized to a constant + coefficient matrix. + The default value is "auto" which will let the solver decide the correct type of + the system passed. + doit : Boolean + Evaluate the solution if True, default value is False + tau: Expression + Used to substitute for the value of `t` after we get the solution of the system. + + Examples + ======== + + To solve the system of ODEs using this function directly, several things must be + done in the right order. Wrong inputs to the function will lead to incorrect results. + + >>> from sympy import symbols, Function, Eq + >>> from sympy.solvers.ode.systems import canonical_odes, linear_ode_to_matrix, linodesolve, linodesolve_type + >>> from sympy.solvers.ode.subscheck import checkodesol + >>> f, g = symbols("f, g", cls=Function) + >>> x, a = symbols("x, a") + >>> funcs = [f(x), g(x)] + >>> eqs = [Eq(f(x).diff(x) - f(x), a*g(x) + 1), Eq(g(x).diff(x) + g(x), a*f(x))] + + Here, it is important to note that before we derive the coefficient matrix, it is + important to get the system of ODEs into the desired form. For that we will use + :obj:`sympy.solvers.ode.systems.canonical_odes()`. + + >>> eqs = canonical_odes(eqs, funcs, x) + >>> eqs + [[Eq(Derivative(f(x), x), a*g(x) + f(x) + 1), Eq(Derivative(g(x), x), a*f(x) - g(x))]] + + Now, we will use :obj:`sympy.solvers.ode.systems.linear_ode_to_matrix()` to get the coefficient matrix and the + non-homogeneous term if it is there. + + >>> eqs = eqs[0] + >>> (A1, A0), b = linear_ode_to_matrix(eqs, funcs, x, 1) + >>> A = A0 + + We have the coefficient matrices and the non-homogeneous term ready. Now, we can use + :obj:`sympy.solvers.ode.systems.linodesolve_type()` to get the information for the system of ODEs + to finally pass it to the solver. + + >>> system_info = linodesolve_type(A, x, b=b) + >>> sol_vector = linodesolve(A, x, b=b, B=system_info['antiderivative'], type=system_info['type_of_equation']) + + Now, we can prove if the solution is correct or not by using :obj:`sympy.solvers.ode.checkodesol()` + + >>> sol = [Eq(f, s) for f, s in zip(funcs, sol_vector)] + >>> checkodesol(eqs, sol) + (True, [0, 0]) + + We can also use the doit method to evaluate the solutions passed by the function. + + >>> sol_vector_evaluated = linodesolve(A, x, b=b, type="type2", doit=True) + + Now, we will look at a system of ODEs which is non-constant. + + >>> eqs = [Eq(f(x).diff(x), f(x) + x*g(x)), Eq(g(x).diff(x), -x*f(x) + g(x))] + + The system defined above is already in the desired form, so we do not have to convert it. + + >>> (A1, A0), b = linear_ode_to_matrix(eqs, funcs, x, 1) + >>> A = A0 + + A user can also pass the commutative antiderivative required for type3 and type4 system of ODEs. + Passing an incorrect one will lead to incorrect results. If the coefficient matrix is not commutative + with its antiderivative, then :obj:`sympy.solvers.ode.systems.linodesolve_type()` raises a NotImplementedError. + If it does have a commutative antiderivative, then the function just returns the information about the system. + + >>> system_info = linodesolve_type(A, x, b=b) + + Now, we can pass the antiderivative as an argument to get the solution. If the system information is not + passed, then the solver will compute the required arguments internally. + + >>> sol_vector = linodesolve(A, x, b=b) + + Once again, we can verify the solution obtained. + + >>> sol = [Eq(f, s) for f, s in zip(funcs, sol_vector)] + >>> checkodesol(eqs, sol) + (True, [0, 0]) + + Returns + ======= + + List + + Raises + ====== + + ValueError + This error is raised when the coefficient matrix, non-homogeneous term + or the antiderivative, if passed, are not a matrix or + do not have correct dimensions + NonSquareMatrixError + When the coefficient matrix or its antiderivative, if passed is not a + square matrix + NotImplementedError + If the coefficient matrix does not have a commutative antiderivative + + See Also + ======== + + linear_ode_to_matrix: Coefficient matrix computation function + canonical_odes: System of ODEs representation change + linodesolve_type: Getting information about systems of ODEs to pass in this solver + + """ + + if not isinstance(A, MatrixBase): + raise ValueError(filldedent('''\ + The coefficients of the system of ODEs should be of type Matrix + ''')) + + if not A.is_square: + raise NonSquareMatrixError(filldedent('''\ + The coefficient matrix must be a square + ''')) + + if b is not None: + if not isinstance(b, MatrixBase): + raise ValueError(filldedent('''\ + The non-homogeneous terms of the system of ODEs should be of type Matrix + ''')) + + if A.rows != b.rows: + raise ValueError(filldedent('''\ + The system of ODEs should have the same number of non-homogeneous terms and the number of + equations + ''')) + + if B is not None: + if not isinstance(B, MatrixBase): + raise ValueError(filldedent('''\ + The antiderivative of coefficients of the system of ODEs should be of type Matrix + ''')) + + if not B.is_square: + raise NonSquareMatrixError(filldedent('''\ + The antiderivative of the coefficient matrix must be a square + ''')) + + if A.rows != B.rows: + raise ValueError(filldedent('''\ + The coefficient matrix and its antiderivative should have same dimensions + ''')) + + if not any(type == "type{}".format(i) for i in range(1, 7)) and not type == "auto": + raise ValueError(filldedent('''\ + The input type should be a valid one + ''')) + + n = A.rows + + # constants = numbered_symbols(prefix='C', cls=Dummy, start=const_idx+1) + Cvect = Matrix([Dummy() for _ in range(n)]) + + if b is None and any(type == typ for typ in ["type2", "type4", "type6"]): + b = zeros(n, 1) + + is_transformed = tau is not None + passed_type = type + + if type == "auto": + system_info = linodesolve_type(A, t, b=b) + type = system_info["type_of_equation"] + B = system_info["antiderivative"] + + if type in ("type5", "type6"): + is_transformed = True + if passed_type != "auto": + if tau is None: + system_info = _first_order_type5_6_subs(A, t, b=b) + if not system_info: + raise ValueError(filldedent(''' + The system passed isn't {}. + '''.format(type))) + + tau = system_info['tau'] + t = system_info['t_'] + A = system_info['A'] + b = system_info['b'] + + intx_wrtt = lambda x: Integral(x, t) if x else 0 + if type in ("type1", "type2", "type5", "type6"): + P, J = matrix_exp_jordan_form(A, t) + P = simplify(P) + + if type in ("type1", "type5"): + sol_vector = P * (J * Cvect) + else: + Jinv = J.subs(t, -t) + sol_vector = P * J * ((Jinv * P.inv() * b).applyfunc(intx_wrtt) + Cvect) + else: + if B is None: + B, _ = _is_commutative_anti_derivative(A, t) + + if type == "type3": + sol_vector = B.exp() * Cvect + else: + sol_vector = B.exp() * (((-B).exp() * b).applyfunc(intx_wrtt) + Cvect) + + if is_transformed: + sol_vector = sol_vector.subs(t, tau) + + gens = sol_vector.atoms(exp) + + if type != "type1": + sol_vector = [expand_mul(s) for s in sol_vector] + + sol_vector = [collect(s, ordered(gens), exact=True) for s in sol_vector] + + if doit: + sol_vector = [s.doit() for s in sol_vector] + + return sol_vector + + +def _matrix_is_constant(M, t): + """Checks if the matrix M is independent of t or not.""" + return all(coef.as_independent(t, as_Add=True)[1] == 0 for coef in M) + + +def canonical_odes(eqs, funcs, t): + r""" + Function that solves for highest order derivatives in a system + + Explanation + =========== + + This function inputs a system of ODEs and based on the system, + the dependent variables and their highest order, returns the system + in the following form: + + .. math:: + X'(t) = A(t) X(t) + b(t) + + Here, $X(t)$ is the vector of dependent variables of lower order, $A(t)$ is + the coefficient matrix, $b(t)$ is the non-homogeneous term and $X'(t)$ is the + vector of dependent variables in their respective highest order. We use the term + canonical form to imply the system of ODEs which is of the above form. + + If the system passed has a non-linear term with multiple solutions, then a list of + systems is returned in its canonical form. + + Parameters + ========== + + eqs : List + List of the ODEs + funcs : List + List of dependent variables + t : Symbol + Independent variable + + Examples + ======== + + >>> from sympy import symbols, Function, Eq, Derivative + >>> from sympy.solvers.ode.systems import canonical_odes + >>> f, g = symbols("f g", cls=Function) + >>> x, y = symbols("x y") + >>> funcs = [f(x), g(x)] + >>> eqs = [Eq(f(x).diff(x) - 7*f(x), 12*g(x)), Eq(g(x).diff(x) + g(x), 20*f(x))] + + >>> canonical_eqs = canonical_odes(eqs, funcs, x) + >>> canonical_eqs + [[Eq(Derivative(f(x), x), 7*f(x) + 12*g(x)), Eq(Derivative(g(x), x), 20*f(x) - g(x))]] + + >>> system = [Eq(Derivative(f(x), x)**2 - 2*Derivative(f(x), x) + 1, 4), Eq(-y*f(x) + Derivative(g(x), x), 0)] + + >>> canonical_system = canonical_odes(system, funcs, x) + >>> canonical_system + [[Eq(Derivative(f(x), x), -1), Eq(Derivative(g(x), x), y*f(x))], [Eq(Derivative(f(x), x), 3), Eq(Derivative(g(x), x), y*f(x))]] + + Returns + ======= + + List + + """ + from sympy.solvers.solvers import solve + + order = _get_func_order(eqs, funcs) + + canon_eqs = solve(eqs, *[func.diff(t, order[func]) for func in funcs], dict=True) + + systems = [] + for eq in canon_eqs: + system = [Eq(func.diff(t, order[func]), eq[func.diff(t, order[func])]) for func in funcs] + systems.append(system) + + return systems + + +def _is_commutative_anti_derivative(A, t): + r""" + Helper function for determining if the Matrix passed is commutative with its antiderivative + + Explanation + =========== + + This function checks if the Matrix $A$ passed is commutative with its antiderivative with respect + to the independent variable $t$. + + .. math:: + B(t) = \int A(t) dt + + The function outputs two values, first one being the antiderivative $B(t)$, second one being a + boolean value, if True, then the matrix $A(t)$ passed is commutative with $B(t)$, else the matrix + passed isn't commutative with $B(t)$. + + Parameters + ========== + + A : Matrix + The matrix which has to be checked + t : Symbol + Independent variable + + Examples + ======== + + >>> from sympy import symbols, Matrix + >>> from sympy.solvers.ode.systems import _is_commutative_anti_derivative + >>> t = symbols("t") + >>> A = Matrix([[1, t], [-t, 1]]) + + >>> B, is_commuting = _is_commutative_anti_derivative(A, t) + >>> is_commuting + True + + Returns + ======= + + Matrix, Boolean + + """ + B = integrate(A, t) + is_commuting = (B*A - A*B).applyfunc(expand).applyfunc(factor_terms).is_zero_matrix + + is_commuting = False if is_commuting is None else is_commuting + + return B, is_commuting + + +def _factor_matrix(A, t): + term = None + for element in A: + temp_term = element.as_independent(t)[1] + if temp_term.has(t): + term = temp_term + break + + if term is not None: + A_factored = (A/term).applyfunc(ratsimp) + can_factor = _matrix_is_constant(A_factored, t) + term = (term, A_factored) if can_factor else None + + return term + + +def _is_second_order_type2(A, t): + term = _factor_matrix(A, t) + is_type2 = False + + if term is not None: + term = 1/term[0] + is_type2 = term.is_polynomial() + + if is_type2: + poly = Poly(term.expand(), t) + monoms = poly.monoms() + + if monoms[0][0] in (2, 4): + cs = _get_poly_coeffs(poly, 4) + a, b, c, d, e = cs + + a1 = powdenest(sqrt(a), force=True) + c1 = powdenest(sqrt(e), force=True) + b1 = powdenest(sqrt(c - 2*a1*c1), force=True) + + is_type2 = (b == 2*a1*b1) and (d == 2*b1*c1) + term = a1*t**2 + b1*t + c1 + + else: + is_type2 = False + + return is_type2, term + + +def _get_poly_coeffs(poly, order): + cs = [0 for _ in range(order+1)] + for c, m in zip(poly.coeffs(), poly.monoms()): + cs[-1-m[0]] = c + return cs + + +def _match_second_order_type(A1, A0, t, b=None): + r""" + Works only for second order system in its canonical form. + + Type 0: Constant coefficient matrix, can be simply solved by + introducing dummy variables. + Type 1: When the substitution: $U = t*X' - X$ works for reducing + the second order system to first order system. + Type 2: When the system is of the form: $poly * X'' = A*X$ where + $poly$ is square of a quadratic polynomial with respect to + *t* and $A$ is a constant coefficient matrix. + + """ + match = {"type_of_equation": "type0"} + n = A1.shape[0] + + if _matrix_is_constant(A1, t) and _matrix_is_constant(A0, t): + return match + + if (A1 + A0*t).applyfunc(expand_mul).is_zero_matrix: + match.update({"type_of_equation": "type1", "A1": A1}) + + elif A1.is_zero_matrix and (b is None or b.is_zero_matrix): + is_type2, term = _is_second_order_type2(A0, t) + if is_type2: + a, b, c = _get_poly_coeffs(Poly(term, t), 2) + A = (A0*(term**2).expand()).applyfunc(ratsimp) + (b**2/4 - a*c)*eye(n, n) + tau = integrate(1/term, t) + t_ = Symbol("{}_".format(t)) + match.update({"type_of_equation": "type2", "A0": A, + "g(t)": sqrt(term), "tau": tau, "is_transformed": True, + "t_": t_}) + + return match + + +def _second_order_subs_type1(A, b, funcs, t): + r""" + For a linear, second order system of ODEs, a particular substitution. + + A system of the below form can be reduced to a linear first order system of + ODEs: + .. math:: + X'' = A(t) * (t*X' - X) + b(t) + + By substituting: + .. math:: U = t*X' - X + + To get the system: + .. math:: U' = t*(A(t)*U + b(t)) + + Where $U$ is the vector of dependent variables, $X$ is the vector of dependent + variables in `funcs` and $X'$ is the first order derivative of $X$ with respect to + $t$. It may or may not reduce the system into linear first order system of ODEs. + + Then a check is made to determine if the system passed can be reduced or not, if + this substitution works, then the system is reduced and its solved for the new + substitution. After we get the solution for $U$: + + .. math:: U = a(t) + + We substitute and return the reduced system: + + .. math:: + a(t) = t*X' - X + + Parameters + ========== + + A: Matrix + Coefficient matrix($A(t)*t$) of the second order system of this form. + b: Matrix + Non-homogeneous term($b(t)$) of the system of ODEs. + funcs: List + List of dependent variables + t: Symbol + Independent variable of the system of ODEs. + + Returns + ======= + + List + + """ + + U = Matrix([t*func.diff(t) - func for func in funcs]) + + sol = linodesolve(A, t, t*b) + reduced_eqs = [Eq(u, s) for s, u in zip(sol, U)] + reduced_eqs = canonical_odes(reduced_eqs, funcs, t)[0] + + return reduced_eqs + + +def _second_order_subs_type2(A, funcs, t_): + r""" + Returns a second order system based on the coefficient matrix passed. + + Explanation + =========== + + This function returns a system of second order ODE of the following form: + + .. math:: + X'' = A * X + + Here, $X$ is the vector of dependent variables, but a bit modified, $A$ is the + coefficient matrix passed. + + Along with returning the second order system, this function also returns the new + dependent variables with the new independent variable `t_` passed. + + Parameters + ========== + + A: Matrix + Coefficient matrix of the system + funcs: List + List of old dependent variables + t_: Symbol + New independent variable + + Returns + ======= + + List, List + + """ + func_names = [func.func.__name__ for func in funcs] + new_funcs = [Function(Dummy("{}_".format(name)))(t_) for name in func_names] + rhss = A * Matrix(new_funcs) + new_eqs = [Eq(func.diff(t_, 2), rhs) for func, rhs in zip(new_funcs, rhss)] + + return new_eqs, new_funcs + + +def _is_euler_system(As, t): + return all(_matrix_is_constant((A*t**i).applyfunc(ratsimp), t) for i, A in enumerate(As)) + + +def _classify_linear_system(eqs, funcs, t, is_canon=False): + r""" + Returns a dictionary with details of the eqs if the system passed is linear + and can be classified by this function else returns None + + Explanation + =========== + + This function takes the eqs, converts it into a form Ax = b where x is a vector of terms + containing dependent variables and their derivatives till their maximum order. If it is + possible to convert eqs into Ax = b, then all the equations in eqs are linear otherwise + they are non-linear. + + To check if the equations are constant coefficient, we need to check if all the terms in + A obtained above are constant or not. + + To check if the equations are homogeneous or not, we need to check if b is a zero matrix + or not. + + Parameters + ========== + + eqs: List + List of ODEs + funcs: List + List of dependent variables + t: Symbol + Independent variable of the equations in eqs + is_canon: Boolean + If True, then this function will not try to get the + system in canonical form. Default value is False + + Returns + ======= + + match = { + 'no_of_equation': len(eqs), + 'eq': eqs, + 'func': funcs, + 'order': order, + 'is_linear': is_linear, + 'is_constant': is_constant, + 'is_homogeneous': is_homogeneous, + } + + Dict or list of Dicts or None + Dict with values for keys: + 1. no_of_equation: Number of equations + 2. eq: The set of equations + 3. func: List of dependent variables + 4. order: A dictionary that gives the order of the + dependent variable in eqs + 5. is_linear: Boolean value indicating if the set of + equations are linear or not. + 6. is_constant: Boolean value indicating if the set of + equations have constant coefficients or not. + 7. is_homogeneous: Boolean value indicating if the set of + equations are homogeneous or not. + 8. commutative_antiderivative: Antiderivative of the coefficient + matrix if the coefficient matrix is non-constant + and commutative with its antiderivative. This key + may or may not exist. + 9. is_general: Boolean value indicating if the system of ODEs is + solvable using one of the general case solvers or not. + 10. rhs: rhs of the non-homogeneous system of ODEs in Matrix form. This + key may or may not exist. + 11. is_higher_order: True if the system passed has an order greater than 1. + This key may or may not exist. + 12. is_second_order: True if the system passed is a second order ODE. This + key may or may not exist. + This Dict is the answer returned if the eqs are linear and constant + coefficient. Otherwise, None is returned. + + """ + + # Error for i == 0 can be added but isn't for now + + # Check for len(funcs) == len(eqs) + if len(funcs) != len(eqs): + raise ValueError("Number of functions given is not equal to the number of equations %s" % funcs) + + # ValueError when functions have more than one arguments + for func in funcs: + if len(func.args) != 1: + raise ValueError("dsolve() and classify_sysode() work with " + "functions of one variable only, not %s" % func) + + # Getting the func_dict and order using the helper + # function + order = _get_func_order(eqs, funcs) + system_order = max(order[func] for func in funcs) + is_higher_order = system_order > 1 + is_second_order = system_order == 2 and all(order[func] == 2 for func in funcs) + + # Not adding the check if the len(func.args) for + # every func in funcs is 1 + + # Linearity check + try: + + canon_eqs = canonical_odes(eqs, funcs, t) if not is_canon else [eqs] + if len(canon_eqs) == 1: + As, b = linear_ode_to_matrix(canon_eqs[0], funcs, t, system_order) + else: + + match = { + 'is_implicit': True, + 'canon_eqs': canon_eqs + } + + return match + + # When the system of ODEs is non-linear, an ODENonlinearError is raised. + # This function catches the error and None is returned. + except ODENonlinearError: + return None + + is_linear = True + + # Homogeneous check + is_homogeneous = True if b.is_zero_matrix else False + + # Is general key is used to identify if the system of ODEs can be solved by + # one of the general case solvers or not. + match = { + 'no_of_equation': len(eqs), + 'eq': eqs, + 'func': funcs, + 'order': order, + 'is_linear': is_linear, + 'is_homogeneous': is_homogeneous, + 'is_general': True + } + + if not is_homogeneous: + match['rhs'] = b + + is_constant = all(_matrix_is_constant(A_, t) for A_ in As) + + # The match['is_linear'] check will be added in the future when this + # function becomes ready to deal with non-linear systems of ODEs + + if not is_higher_order: + A = As[1] + match['func_coeff'] = A + + # Constant coefficient check + is_constant = _matrix_is_constant(A, t) + match['is_constant'] = is_constant + + try: + system_info = linodesolve_type(A, t, b=b) + except NotImplementedError: + return None + + match.update(system_info) + antiderivative = match.pop("antiderivative") + + if not is_constant: + match['commutative_antiderivative'] = antiderivative + + return match + else: + match['type_of_equation'] = "type0" + + if is_second_order: + A1, A0 = As[1:] + + match_second_order = _match_second_order_type(A1, A0, t) + match.update(match_second_order) + + match['is_second_order'] = True + + # If system is constant, then no need to check if its in euler + # form or not. It will be easier and faster to directly proceed + # to solve it. + if match['type_of_equation'] == "type0" and not is_constant: + is_euler = _is_euler_system(As, t) + if is_euler: + t_ = Symbol('{}_'.format(t)) + match.update({'is_transformed': True, 'type_of_equation': 'type1', + 't_': t_}) + else: + is_jordan = lambda M: M == Matrix.jordan_block(M.shape[0], M[0, 0]) + terms = _factor_matrix(As[-1], t) + if all(A.is_zero_matrix for A in As[1:-1]) and terms is not None and not is_jordan(terms[1]): + P, J = terms[1].jordan_form() + match.update({'type_of_equation': 'type2', 'J': J, + 'f(t)': terms[0], 'P': P, 'is_transformed': True}) + + if match['type_of_equation'] != 'type0' and is_second_order: + match.pop('is_second_order', None) + + match['is_higher_order'] = is_higher_order + + return match + +def _preprocess_eqs(eqs): + processed_eqs = [] + for eq in eqs: + processed_eqs.append(eq if isinstance(eq, Equality) else Eq(eq, 0)) + + return processed_eqs + + +def _eqs2dict(eqs, funcs): + eqsorig = {} + eqsmap = {} + funcset = set(funcs) + for eq in eqs: + f1, = eq.lhs.atoms(AppliedUndef) + f2s = (eq.rhs.atoms(AppliedUndef) - {f1}) & funcset + eqsmap[f1] = f2s + eqsorig[f1] = eq + return eqsmap, eqsorig + + +def _dict2graph(d): + nodes = list(d) + edges = [(f1, f2) for f1, f2s in d.items() for f2 in f2s] + G = (nodes, edges) + return G + + +def _is_type1(scc, t): + eqs, funcs = scc + + try: + (A1, A0), b = linear_ode_to_matrix(eqs, funcs, t, 1) + except (ODENonlinearError, ODEOrderError): + return False + + if _matrix_is_constant(A0, t) and b.is_zero_matrix: + return True + + return False + + +def _combine_type1_subsystems(subsystem, funcs, t): + indices = [i for i, sys in enumerate(zip(subsystem, funcs)) if _is_type1(sys, t)] + remove = set() + for ip, i in enumerate(indices): + for j in indices[ip+1:]: + if any(eq2.has(funcs[i]) for eq2 in subsystem[j]): + subsystem[j] = subsystem[i] + subsystem[j] + remove.add(i) + subsystem = [sys for i, sys in enumerate(subsystem) if i not in remove] + return subsystem + + +def _component_division(eqs, funcs, t): + + # Assuming that each eq in eqs is in canonical form, + # that is, [f(x).diff(x) = .., g(x).diff(x) = .., etc] + # and that the system passed is in its first order + eqsmap, eqsorig = _eqs2dict(eqs, funcs) + + subsystems = [] + for cc in connected_components(_dict2graph(eqsmap)): + eqsmap_c = {f: eqsmap[f] for f in cc} + sccs = strongly_connected_components(_dict2graph(eqsmap_c)) + subsystem = [[eqsorig[f] for f in scc] for scc in sccs] + subsystem = _combine_type1_subsystems(subsystem, sccs, t) + subsystems.append(subsystem) + + return subsystems + + +# Returns: List of equations +def _linear_ode_solver(match): + t = match['t'] + funcs = match['func'] + + rhs = match.get('rhs', None) + tau = match.get('tau', None) + t = match['t_'] if 't_' in match else t + A = match['func_coeff'] + + # Note: To make B None when the matrix has constant + # coefficient + B = match.get('commutative_antiderivative', None) + type = match['type_of_equation'] + + sol_vector = linodesolve(A, t, b=rhs, B=B, + type=type, tau=tau) + + sol = [Eq(f, s) for f, s in zip(funcs, sol_vector)] + + return sol + + +def _select_equations(eqs, funcs, key=lambda x: x): + eq_dict = {e.lhs: e.rhs for e in eqs} + return [Eq(f, eq_dict[key(f)]) for f in funcs] + + +def _higher_order_ode_solver(match): + eqs = match["eq"] + funcs = match["func"] + t = match["t"] + sysorder = match['order'] + type = match.get('type_of_equation', "type0") + + is_second_order = match.get('is_second_order', False) + is_transformed = match.get('is_transformed', False) + is_euler = is_transformed and type == "type1" + is_higher_order_type2 = is_transformed and type == "type2" and 'P' in match + + if is_second_order: + new_eqs, new_funcs = _second_order_to_first_order(eqs, funcs, t, + A1=match.get("A1", None), A0=match.get("A0", None), + b=match.get("rhs", None), type=type, + t_=match.get("t_", None)) + else: + new_eqs, new_funcs = _higher_order_to_first_order(eqs, sysorder, t, funcs=funcs, + type=type, J=match.get('J', None), + f_t=match.get('f(t)', None), + P=match.get('P', None), b=match.get('rhs', None)) + + if is_transformed: + t = match.get('t_', t) + + if not is_higher_order_type2: + new_eqs = _select_equations(new_eqs, [f.diff(t) for f in new_funcs]) + + sol = None + + # NotImplementedError may be raised when the system may be actually + # solvable if it can be just divided into sub-systems + try: + if not is_higher_order_type2: + sol = _strong_component_solver(new_eqs, new_funcs, t) + except NotImplementedError: + sol = None + + # Dividing the system only when it becomes essential + if sol is None: + try: + sol = _component_solver(new_eqs, new_funcs, t) + except NotImplementedError: + sol = None + + if sol is None: + return sol + + is_second_order_type2 = is_second_order and type == "type2" + + underscores = '__' if is_transformed else '_' + + sol = _select_equations(sol, funcs, + key=lambda x: Function(Dummy('{}{}0'.format(x.func.__name__, underscores)))(t)) + + if match.get("is_transformed", False): + if is_second_order_type2: + g_t = match["g(t)"] + tau = match["tau"] + sol = [Eq(s.lhs, s.rhs.subs(t, tau) * g_t) for s in sol] + elif is_euler: + t = match['t'] + tau = match['t_'] + sol = [s.subs(tau, log(t)) for s in sol] + elif is_higher_order_type2: + P = match['P'] + sol_vector = P * Matrix([s.rhs for s in sol]) + sol = [Eq(f, s) for f, s in zip(funcs, sol_vector)] + + return sol + + +# Returns: List of equations or None +# If None is returned by this solver, then the system +# of ODEs cannot be solved directly by dsolve_system. +def _strong_component_solver(eqs, funcs, t): + from sympy.solvers.ode.ode import dsolve, constant_renumber + + match = _classify_linear_system(eqs, funcs, t, is_canon=True) + sol = None + + # Assuming that we can't get an implicit system + # since we are already canonical equations from + # dsolve_system + if match: + match['t'] = t + + if match.get('is_higher_order', False): + sol = _higher_order_ode_solver(match) + + elif match.get('is_linear', False): + sol = _linear_ode_solver(match) + + # Note: For now, only linear systems are handled by this function + # hence, the match condition is added. This can be removed later. + if sol is None and len(eqs) == 1: + sol = dsolve(eqs[0], func=funcs[0]) + variables = Tuple(eqs[0]).free_symbols + new_constants = [Dummy() for _ in range(ode_order(eqs[0], funcs[0]))] + sol = constant_renumber(sol, variables=variables, newconstants=new_constants) + sol = [sol] + + # To add non-linear case here in future + + return sol + + +def _get_funcs_from_canon(eqs): + return [eq.lhs.args[0] for eq in eqs] + + +# Returns: List of Equations(a solution) +def _weak_component_solver(wcc, t): + + # We will divide the systems into sccs + # only when the wcc cannot be solved as + # a whole + eqs = [] + for scc in wcc: + eqs += scc + funcs = _get_funcs_from_canon(eqs) + + sol = _strong_component_solver(eqs, funcs, t) + if sol: + return sol + + sol = [] + + for scc in wcc: + eqs = scc + funcs = _get_funcs_from_canon(eqs) + + # Substituting solutions for the dependent + # variables solved in previous SCC, if any solved. + comp_eqs = [eq.subs({s.lhs: s.rhs for s in sol}) for eq in eqs] + scc_sol = _strong_component_solver(comp_eqs, funcs, t) + + if scc_sol is None: + raise NotImplementedError(filldedent(''' + The system of ODEs passed cannot be solved by dsolve_system. + ''')) + + # scc_sol: List of equations + # scc_sol is a solution + sol += scc_sol + + return sol + + +# Returns: List of Equations(a solution) +def _component_solver(eqs, funcs, t): + components = _component_division(eqs, funcs, t) + sol = [] + + for wcc in components: + + # wcc_sol: List of Equations + sol += _weak_component_solver(wcc, t) + + # sol: List of Equations + return sol + + +def _second_order_to_first_order(eqs, funcs, t, type="auto", A1=None, + A0=None, b=None, t_=None): + r""" + Expects the system to be in second order and in canonical form + + Explanation + =========== + + Reduces a second order system into a first order one depending on the type of second + order system. + 1. "type0": If this is passed, then the system will be reduced to first order by + introducing dummy variables. + 2. "type1": If this is passed, then a particular substitution will be used to reduce the + the system into first order. + 3. "type2": If this is passed, then the system will be transformed with new dependent + variables and independent variables. This transformation is a part of solving + the corresponding system of ODEs. + + `A1` and `A0` are the coefficient matrices from the system and it is assumed that the + second order system has the form given below: + + .. math:: + A2 * X'' = A1 * X' + A0 * X + b + + Here, $A2$ is the coefficient matrix for the vector $X''$ and $b$ is the non-homogeneous + term. + + Default value for `b` is None but if `A1` and `A0` are passed and `b` is not passed, then the + system will be assumed homogeneous. + + """ + is_a1 = A1 is None + is_a0 = A0 is None + + if (type == "type1" and is_a1) or (type == "type2" and is_a0)\ + or (type == "auto" and (is_a1 or is_a0)): + (A2, A1, A0), b = linear_ode_to_matrix(eqs, funcs, t, 2) + + if not A2.is_Identity: + raise ValueError(filldedent(''' + The system must be in its canonical form. + ''')) + + if type == "auto": + match = _match_second_order_type(A1, A0, t) + type = match["type_of_equation"] + A1 = match.get("A1", None) + A0 = match.get("A0", None) + + sys_order = dict.fromkeys(funcs, 2) + + if type == "type1": + if b is None: + b = zeros(len(eqs)) + eqs = _second_order_subs_type1(A1, b, funcs, t) + sys_order = dict.fromkeys(funcs, 1) + + if type == "type2": + if t_ is None: + t_ = Symbol("{}_".format(t)) + t = t_ + eqs, funcs = _second_order_subs_type2(A0, funcs, t_) + sys_order = dict.fromkeys(funcs, 2) + + return _higher_order_to_first_order(eqs, sys_order, t, funcs=funcs) + + +def _higher_order_type2_to_sub_systems(J, f_t, funcs, t, max_order, b=None, P=None): + + # Note: To add a test for this ValueError + if J is None or f_t is None or not _matrix_is_constant(J, t): + raise ValueError(filldedent(''' + Correctly input for args 'A' and 'f_t' for Linear, Higher Order, + Type 2 + ''')) + + if P is None and b is not None and not b.is_zero_matrix: + raise ValueError(filldedent(''' + Provide the keyword 'P' for matrix P in A = P * J * P-1. + ''')) + + new_funcs = Matrix([Function(Dummy('{}__0'.format(f.func.__name__)))(t) for f in funcs]) + new_eqs = new_funcs.diff(t, max_order) - f_t * J * new_funcs + + if b is not None and not b.is_zero_matrix: + new_eqs -= P.inv() * b + + new_eqs = canonical_odes(new_eqs, new_funcs, t)[0] + + return new_eqs, new_funcs + + +def _higher_order_to_first_order(eqs, sys_order, t, funcs=None, type="type0", **kwargs): + if funcs is None: + funcs = sys_order.keys() + + # Standard Cauchy Euler system + if type == "type1": + t_ = Symbol('{}_'.format(t)) + new_funcs = [Function(Dummy('{}_'.format(f.func.__name__)))(t_) for f in funcs] + max_order = max(sys_order[func] for func in funcs) + subs_dict = dict(zip(funcs, new_funcs)) + subs_dict[t] = exp(t_) + + free_function = Function(Dummy()) + + def _get_coeffs_from_subs_expression(expr): + if isinstance(expr, Subs): + free_symbol = expr.args[1][0] + term = expr.args[0] + return {ode_order(term, free_symbol): 1} + + if isinstance(expr, Mul): + coeff = expr.args[0] + order = list(_get_coeffs_from_subs_expression(expr.args[1]).keys())[0] + return {order: coeff} + + if isinstance(expr, Add): + coeffs = {} + for arg in expr.args: + + if isinstance(arg, Mul): + coeffs.update(_get_coeffs_from_subs_expression(arg)) + + else: + order = list(_get_coeffs_from_subs_expression(arg).keys())[0] + coeffs[order] = 1 + + return coeffs + + for o in range(1, max_order + 1): + expr = free_function(log(t_)).diff(t_, o)*t_**o + coeff_dict = _get_coeffs_from_subs_expression(expr) + coeffs = [coeff_dict[order] if order in coeff_dict else 0 for order in range(o + 1)] + expr_to_subs = sum(free_function(t_).diff(t_, i) * c for i, c in + enumerate(coeffs)) / t**o + subs_dict.update({f.diff(t, o): expr_to_subs.subs(free_function(t_), nf) + for f, nf in zip(funcs, new_funcs)}) + + new_eqs = [eq.subs(subs_dict) for eq in eqs] + new_sys_order = {nf: sys_order[f] for f, nf in zip(funcs, new_funcs)} + + new_eqs = canonical_odes(new_eqs, new_funcs, t_)[0] + + return _higher_order_to_first_order(new_eqs, new_sys_order, t_, funcs=new_funcs) + + # Systems of the form: X(n)(t) = f(t)*A*X + b + # where X(n)(t) is the nth derivative of the vector of dependent variables + # with respect to the independent variable and A is a constant matrix. + if type == "type2": + J = kwargs.get('J', None) + f_t = kwargs.get('f_t', None) + b = kwargs.get('b', None) + P = kwargs.get('P', None) + max_order = max(sys_order[func] for func in funcs) + + return _higher_order_type2_to_sub_systems(J, f_t, funcs, t, max_order, P=P, b=b) + + # Note: To be changed to this after doit option is disabled for default cases + # new_sysorder = _get_func_order(new_eqs, new_funcs) + # + # return _higher_order_to_first_order(new_eqs, new_sysorder, t, funcs=new_funcs) + + new_funcs = [] + + for prev_func in funcs: + func_name = prev_func.func.__name__ + func = Function(Dummy('{}_0'.format(func_name)))(t) + new_funcs.append(func) + subs_dict = {prev_func: func} + new_eqs = [] + + for i in range(1, sys_order[prev_func]): + new_func = Function(Dummy('{}_{}'.format(func_name, i)))(t) + subs_dict[prev_func.diff(t, i)] = new_func + new_funcs.append(new_func) + + prev_f = subs_dict[prev_func.diff(t, i-1)] + new_eq = Eq(prev_f.diff(t), new_func) + new_eqs.append(new_eq) + + eqs = [eq.subs(subs_dict) for eq in eqs] + new_eqs + + return eqs, new_funcs + + +def dsolve_system(eqs, funcs=None, t=None, ics=None, doit=False, simplify=True): + r""" + Solves any(supported) system of Ordinary Differential Equations + + Explanation + =========== + + This function takes a system of ODEs as an input, determines if the + it is solvable by this function, and returns the solution if found any. + + This function can handle: + 1. Linear, First Order, Constant coefficient homogeneous system of ODEs + 2. Linear, First Order, Constant coefficient non-homogeneous system of ODEs + 3. Linear, First Order, non-constant coefficient homogeneous system of ODEs + 4. Linear, First Order, non-constant coefficient non-homogeneous system of ODEs + 5. Any implicit system which can be divided into system of ODEs which is of the above 4 forms + 6. Any higher order linear system of ODEs that can be reduced to one of the 5 forms of systems described above. + + The types of systems described above are not limited by the number of equations, i.e. this + function can solve the above types irrespective of the number of equations in the system passed. + But, the bigger the system, the more time it will take to solve the system. + + This function returns a list of solutions. Each solution is a list of equations where LHS is + the dependent variable and RHS is an expression in terms of the independent variable. + + Among the non constant coefficient types, not all the systems are solvable by this function. Only + those which have either a coefficient matrix with a commutative antiderivative or those systems which + may be divided further so that the divided systems may have coefficient matrix with commutative antiderivative. + + Parameters + ========== + + eqs : List + system of ODEs to be solved + funcs : List or None + List of dependent variables that make up the system of ODEs + t : Symbol or None + Independent variable in the system of ODEs + ics : Dict or None + Set of initial boundary/conditions for the system of ODEs + doit : Boolean + Evaluate the solutions if True. Default value is True. Can be + set to false if the integral evaluation takes too much time and/or + is not required. + simplify: Boolean + Simplify the solutions for the systems. Default value is True. + Can be set to false if simplification takes too much time and/or + is not required. + + Examples + ======== + + >>> from sympy import symbols, Eq, Function + >>> from sympy.solvers.ode.systems import dsolve_system + >>> f, g = symbols("f g", cls=Function) + >>> x = symbols("x") + + >>> eqs = [Eq(f(x).diff(x), g(x)), Eq(g(x).diff(x), f(x))] + >>> dsolve_system(eqs) + [[Eq(f(x), -C1*exp(-x) + C2*exp(x)), Eq(g(x), C1*exp(-x) + C2*exp(x))]] + + You can also pass the initial conditions for the system of ODEs: + + >>> dsolve_system(eqs, ics={f(0): 1, g(0): 0}) + [[Eq(f(x), exp(x)/2 + exp(-x)/2), Eq(g(x), exp(x)/2 - exp(-x)/2)]] + + Optionally, you can pass the dependent variables and the independent + variable for which the system is to be solved: + + >>> funcs = [f(x), g(x)] + >>> dsolve_system(eqs, funcs=funcs, t=x) + [[Eq(f(x), -C1*exp(-x) + C2*exp(x)), Eq(g(x), C1*exp(-x) + C2*exp(x))]] + + Lets look at an implicit system of ODEs: + + >>> eqs = [Eq(f(x).diff(x)**2, g(x)**2), Eq(g(x).diff(x), g(x))] + >>> dsolve_system(eqs) + [[Eq(f(x), C1 - C2*exp(x)), Eq(g(x), C2*exp(x))], [Eq(f(x), C1 + C2*exp(x)), Eq(g(x), C2*exp(x))]] + + Returns + ======= + + List of List of Equations + + Raises + ====== + + NotImplementedError + When the system of ODEs is not solvable by this function. + ValueError + When the parameters passed are not in the required form. + + """ + from sympy.solvers.ode.ode import solve_ics, _extract_funcs, constant_renumber + + if not iterable(eqs): + raise ValueError(filldedent(''' + List of equations should be passed. The input is not valid. + ''')) + + eqs = _preprocess_eqs(eqs) + + if funcs is not None and not isinstance(funcs, list): + raise ValueError(filldedent(''' + Input to the funcs should be a list of functions. + ''')) + + if funcs is None: + funcs = _extract_funcs(eqs) + + if any(len(func.args) != 1 for func in funcs): + raise ValueError(filldedent(''' + dsolve_system can solve a system of ODEs with only one independent + variable. + ''')) + + if len(eqs) != len(funcs): + raise ValueError(filldedent(''' + Number of equations and number of functions do not match + ''')) + + if t is not None and not isinstance(t, Symbol): + raise ValueError(filldedent(''' + The independent variable must be of type Symbol + ''')) + + if t is None: + t = list(list(eqs[0].atoms(Derivative))[0].atoms(Symbol))[0] + + sols = [] + canon_eqs = canonical_odes(eqs, funcs, t) + + for canon_eq in canon_eqs: + try: + sol = _strong_component_solver(canon_eq, funcs, t) + except NotImplementedError: + sol = None + + if sol is None: + sol = _component_solver(canon_eq, funcs, t) + + sols.append(sol) + + if sols: + final_sols = [] + variables = Tuple(*eqs).free_symbols + + for sol in sols: + + sol = _select_equations(sol, funcs) + sol = constant_renumber(sol, variables=variables) + + if ics: + constants = Tuple(*sol).free_symbols - variables + solved_constants = solve_ics(sol, funcs, constants, ics) + sol = [s.subs(solved_constants) for s in sol] + + if simplify: + constants = Tuple(*sol).free_symbols - variables + sol = simpsol(sol, [t], constants, doit=doit) + + final_sols.append(sol) + + sols = final_sols + + return sols diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_lie_group.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_lie_group.py new file mode 100644 index 0000000000000000000000000000000000000000..153d30ff563773819e49c989f447c1ec7962169b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_lie_group.py @@ -0,0 +1,152 @@ +from sympy.core.function import Function +from sympy.core.numbers import Rational +from sympy.core.relational import Eq +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import (atan, sin, tan) + +from sympy.solvers.ode import (classify_ode, checkinfsol, dsolve, infinitesimals) + +from sympy.solvers.ode.subscheck import checkodesol + +from sympy.testing.pytest import XFAIL + + +C1 = Symbol('C1') +x, y = symbols("x y") +f = Function('f') +xi = Function('xi') +eta = Function('eta') + + +def test_heuristic1(): + a, b, c, a4, a3, a2, a1, a0 = symbols("a b c a4 a3 a2 a1 a0") + df = f(x).diff(x) + eq = Eq(df, x**2*f(x)) + eq1 = f(x).diff(x) + a*f(x) - c*exp(b*x) + eq2 = f(x).diff(x) + 2*x*f(x) - x*exp(-x**2) + eq3 = (1 + 2*x)*df + 2 - 4*exp(-f(x)) + eq4 = f(x).diff(x) - (a4*x**4 + a3*x**3 + a2*x**2 + a1*x + a0)**Rational(-1, 2) + eq5 = x**2*df - f(x) + x**2*exp(x - (1/x)) + eqlist = [eq, eq1, eq2, eq3, eq4, eq5] + + i = infinitesimals(eq, hint='abaco1_simple') + assert i == [{eta(x, f(x)): exp(x**3/3), xi(x, f(x)): 0}, + {eta(x, f(x)): f(x), xi(x, f(x)): 0}, + {eta(x, f(x)): 0, xi(x, f(x)): x**(-2)}] + i1 = infinitesimals(eq1, hint='abaco1_simple') + assert i1 == [{eta(x, f(x)): exp(-a*x), xi(x, f(x)): 0}] + i2 = infinitesimals(eq2, hint='abaco1_simple') + assert i2 == [{eta(x, f(x)): exp(-x**2), xi(x, f(x)): 0}] + i3 = infinitesimals(eq3, hint='abaco1_simple') + assert i3 == [{eta(x, f(x)): 0, xi(x, f(x)): 2*x + 1}, + {eta(x, f(x)): 0, xi(x, f(x)): 1/(exp(f(x)) - 2)}] + i4 = infinitesimals(eq4, hint='abaco1_simple') + assert i4 == [{eta(x, f(x)): 1, xi(x, f(x)): 0}, + {eta(x, f(x)): 0, + xi(x, f(x)): sqrt(a0 + a1*x + a2*x**2 + a3*x**3 + a4*x**4)}] + i5 = infinitesimals(eq5, hint='abaco1_simple') + assert i5 == [{xi(x, f(x)): 0, eta(x, f(x)): exp(-1/x)}] + + ilist = [i, i1, i2, i3, i4, i5] + for eq, i in (zip(eqlist, ilist)): + check = checkinfsol(eq, i) + assert check[0] + + # This ODE can be solved by the Lie Group method, when there are + # better assumptions + eq6 = df - (f(x)/x)*(x*log(x**2/f(x)) + 2) + i = infinitesimals(eq6, hint='abaco1_product') + assert i == [{eta(x, f(x)): f(x)*exp(-x), xi(x, f(x)): 0}] + assert checkinfsol(eq6, i)[0] + + eq7 = x*(f(x).diff(x)) + 1 - f(x)**2 + i = infinitesimals(eq7, hint='chi') + assert checkinfsol(eq7, i)[0] + + +def test_heuristic3(): + a, b = symbols("a b") + df = f(x).diff(x) + + eq = x**2*df + x*f(x) + f(x)**2 + x**2 + i = infinitesimals(eq, hint='bivariate') + assert i == [{eta(x, f(x)): f(x), xi(x, f(x)): x}] + assert checkinfsol(eq, i)[0] + + eq = x**2*(-f(x)**2 + df)- a*x**2*f(x) + 2 - a*x + i = infinitesimals(eq, hint='bivariate') + assert checkinfsol(eq, i)[0] + + +def test_heuristic_function_sum(): + eq = f(x).diff(x) - (3*(1 + x**2/f(x)**2)*atan(f(x)/x) + (1 - 2*f(x))/x + + (1 - 3*f(x))*(x/f(x)**2)) + i = infinitesimals(eq, hint='function_sum') + assert i == [{eta(x, f(x)): f(x)**(-2) + x**(-2), xi(x, f(x)): 0}] + assert checkinfsol(eq, i)[0] + + +def test_heuristic_abaco2_similar(): + a, b = symbols("a b") + F = Function('F') + eq = f(x).diff(x) - F(a*x + b*f(x)) + i = infinitesimals(eq, hint='abaco2_similar') + assert i == [{eta(x, f(x)): -a/b, xi(x, f(x)): 1}] + assert checkinfsol(eq, i)[0] + + eq = f(x).diff(x) - (f(x)**2 / (sin(f(x) - x) - x**2 + 2*x*f(x))) + i = infinitesimals(eq, hint='abaco2_similar') + assert i == [{eta(x, f(x)): f(x)**2, xi(x, f(x)): f(x)**2}] + assert checkinfsol(eq, i)[0] + + +def test_heuristic_abaco2_unique_unknown(): + + a, b = symbols("a b") + F = Function('F') + eq = f(x).diff(x) - x**(a - 1)*(f(x)**(1 - b))*F(x**a/a + f(x)**b/b) + i = infinitesimals(eq, hint='abaco2_unique_unknown') + assert i == [{eta(x, f(x)): -f(x)*f(x)**(-b), xi(x, f(x)): x*x**(-a)}] + assert checkinfsol(eq, i)[0] + + eq = f(x).diff(x) + tan(F(x**2 + f(x)**2) + atan(x/f(x))) + i = infinitesimals(eq, hint='abaco2_unique_unknown') + assert i == [{eta(x, f(x)): x, xi(x, f(x)): -f(x)}] + assert checkinfsol(eq, i)[0] + + eq = (x*f(x).diff(x) + f(x) + 2*x)**2 -4*x*f(x) -4*x**2 -4*a + i = infinitesimals(eq, hint='abaco2_unique_unknown') + assert checkinfsol(eq, i)[0] + + +def test_heuristic_linear(): + a, b, m, n = symbols("a b m n") + + eq = x**(n*(m + 1) - m)*(f(x).diff(x)) - a*f(x)**n -b*x**(n*(m + 1)) + i = infinitesimals(eq, hint='linear') + assert checkinfsol(eq, i)[0] + + +@XFAIL +def test_kamke(): + a, b, alpha, c = symbols("a b alpha c") + eq = x**2*(a*f(x)**2+(f(x).diff(x))) + b*x**alpha + c + i = infinitesimals(eq, hint='sum_function') # XFAIL + assert checkinfsol(eq, i)[0] + + +def test_user_infinitesimals(): + x = Symbol("x") # assuming x is real generates an error + eq = x*(f(x).diff(x)) + 1 - f(x)**2 + sol = Eq(f(x), (C1 + x**2)/(C1 - x**2)) + infinitesimals = {'xi':sqrt(f(x) - 1)/sqrt(f(x) + 1), 'eta':0} + assert dsolve(eq, hint='lie_group', **infinitesimals) == sol + assert checkodesol(eq, sol) == (True, 0) + + +@XFAIL +def test_lie_group_issue15219(): + eqn = exp(f(x).diff(x)-f(x)) + assert 'lie_group' not in classify_ode(eqn, f(x)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_ode.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_ode.py new file mode 100644 index 0000000000000000000000000000000000000000..65e0fa62d52445a4669f3cdc5ef278dbf9c88ea4 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_ode.py @@ -0,0 +1,1105 @@ +from sympy.core.function import (Derivative, Function, Subs, diff) +from sympy.core.numbers import (E, I, Rational, pi) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.complexes import (im, re) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.hyperbolic import acosh +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import (atan2, cos, sin, tan) +from sympy.integrals.integrals import Integral +from sympy.polys.polytools import Poly +from sympy.series.order import O +from sympy.simplify.radsimp import collect + +from sympy.solvers.ode import (classify_ode, + homogeneous_order, dsolve) + +from sympy.solvers.ode.subscheck import checkodesol +from sympy.solvers.ode.ode import (classify_sysode, + constant_renumber, constantsimp, get_numbered_constants, solve_ics) + +from sympy.solvers.ode.nonhomogeneous import _undetermined_coefficients_match +from sympy.solvers.ode.single import LinearCoefficients +from sympy.solvers.deutils import ode_order +from sympy.testing.pytest import XFAIL, raises, slow, SKIP +from sympy.utilities.misc import filldedent + + +C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10 = symbols('C0:11') +u, x, y, z = symbols('u,x:z', real=True) +f = Function('f') +g = Function('g') +h = Function('h') + +# Note: Examples which were specifically testing Single ODE solver are moved to test_single.py +# and all the system of ode examples are moved to test_systems.py +# Note: the tests below may fail (but still be correct) if ODE solver, +# the integral engine, solve(), or even simplify() changes. Also, in +# differently formatted solutions, the arbitrary constants might not be +# equal. Using specific hints in tests can help to avoid this. + +# Tests of order higher than 1 should run the solutions through +# constant_renumber because it will normalize it (constant_renumber causes +# dsolve() to return different results on different machines) + + +def test_get_numbered_constants(): + with raises(ValueError): + get_numbered_constants(None) + + +def test_dsolve_all_hint(): + eq = f(x).diff(x) + output = dsolve(eq, hint='all') + + # Match the Dummy variables: + sol1 = output['separable_Integral'] + _y = sol1.lhs.args[1][0] + sol1 = output['1st_homogeneous_coeff_subs_dep_div_indep_Integral'] + _u1 = sol1.rhs.args[1].args[1][0] + + expected = {'Bernoulli_Integral': Eq(f(x), C1 + Integral(0, x)), + '1st_homogeneous_coeff_best': Eq(f(x), C1), + 'Bernoulli': Eq(f(x), C1), + 'nth_algebraic': Eq(f(x), C1), + 'nth_linear_euler_eq_homogeneous': Eq(f(x), C1), + 'nth_linear_constant_coeff_homogeneous': Eq(f(x), C1), + 'separable': Eq(f(x), C1), + '1st_homogeneous_coeff_subs_indep_div_dep': Eq(f(x), C1), + 'nth_algebraic_Integral': Eq(f(x), C1), + '1st_linear': Eq(f(x), C1), + '1st_linear_Integral': Eq(f(x), C1 + Integral(0, x)), + '1st_exact': Eq(f(x), C1), + '1st_exact_Integral': Eq(Subs(Integral(0, x) + Integral(1, _y), _y, f(x)), C1), + 'lie_group': Eq(f(x), C1), + '1st_homogeneous_coeff_subs_dep_div_indep': Eq(f(x), C1), + '1st_homogeneous_coeff_subs_dep_div_indep_Integral': Eq(log(x), C1 + Integral(-1/_u1, (_u1, f(x)/x))), + '1st_power_series': Eq(f(x), C1), + 'separable_Integral': Eq(Integral(1, (_y, f(x))), C1 + Integral(0, x)), + '1st_homogeneous_coeff_subs_indep_div_dep_Integral': Eq(f(x), C1), + 'best': Eq(f(x), C1), + 'best_hint': 'nth_algebraic', + 'default': 'nth_algebraic', + 'order': 1} + assert output == expected + + assert dsolve(eq, hint='best') == Eq(f(x), C1) + + +def test_dsolve_ics(): + # Maybe this should just use one of the solutions instead of raising... + with raises(NotImplementedError): + dsolve(f(x).diff(x) - sqrt(f(x)), ics={f(1):1}) + + +@slow +def test_dsolve_options(): + eq = x*f(x).diff(x) + f(x) + a = dsolve(eq, hint='all') + b = dsolve(eq, hint='all', simplify=False) + c = dsolve(eq, hint='all_Integral') + keys = ['1st_exact', '1st_exact_Integral', '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_dep_div_indep', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', '1st_linear', + '1st_linear_Integral', 'Bernoulli', 'Bernoulli_Integral', + 'almost_linear', 'almost_linear_Integral', 'best', 'best_hint', + 'default', 'factorable', 'lie_group', + 'nth_linear_euler_eq_homogeneous', 'order', + 'separable', 'separable_Integral'] + Integral_keys = ['1st_exact_Integral', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', '1st_linear_Integral', + 'Bernoulli_Integral', 'almost_linear_Integral', 'best', 'best_hint', 'default', + 'factorable', 'nth_linear_euler_eq_homogeneous', + 'order', 'separable_Integral'] + assert sorted(a.keys()) == keys + assert a['order'] == ode_order(eq, f(x)) + assert a['best'] == Eq(f(x), C1/x) + assert dsolve(eq, hint='best') == Eq(f(x), C1/x) + assert a['default'] == 'factorable' + assert a['best_hint'] == 'factorable' + assert not a['1st_exact'].has(Integral) + assert not a['separable'].has(Integral) + assert not a['1st_homogeneous_coeff_best'].has(Integral) + assert not a['1st_homogeneous_coeff_subs_dep_div_indep'].has(Integral) + assert not a['1st_homogeneous_coeff_subs_indep_div_dep'].has(Integral) + assert not a['1st_linear'].has(Integral) + assert a['1st_linear_Integral'].has(Integral) + assert a['1st_exact_Integral'].has(Integral) + assert a['1st_homogeneous_coeff_subs_dep_div_indep_Integral'].has(Integral) + assert a['1st_homogeneous_coeff_subs_indep_div_dep_Integral'].has(Integral) + assert a['separable_Integral'].has(Integral) + assert sorted(b.keys()) == keys + assert b['order'] == ode_order(eq, f(x)) + assert b['best'] == Eq(f(x), C1/x) + assert dsolve(eq, hint='best', simplify=False) == Eq(f(x), C1/x) + assert b['default'] == 'factorable' + assert b['best_hint'] == 'factorable' + assert a['separable'] != b['separable'] + assert a['1st_homogeneous_coeff_subs_dep_div_indep'] != \ + b['1st_homogeneous_coeff_subs_dep_div_indep'] + assert a['1st_homogeneous_coeff_subs_indep_div_dep'] != \ + b['1st_homogeneous_coeff_subs_indep_div_dep'] + assert not b['1st_exact'].has(Integral) + assert not b['separable'].has(Integral) + assert not b['1st_homogeneous_coeff_best'].has(Integral) + assert not b['1st_homogeneous_coeff_subs_dep_div_indep'].has(Integral) + assert not b['1st_homogeneous_coeff_subs_indep_div_dep'].has(Integral) + assert not b['1st_linear'].has(Integral) + assert b['1st_linear_Integral'].has(Integral) + assert b['1st_exact_Integral'].has(Integral) + assert b['1st_homogeneous_coeff_subs_dep_div_indep_Integral'].has(Integral) + assert b['1st_homogeneous_coeff_subs_indep_div_dep_Integral'].has(Integral) + assert b['separable_Integral'].has(Integral) + assert sorted(c.keys()) == Integral_keys + raises(ValueError, lambda: dsolve(eq, hint='notarealhint')) + raises(ValueError, lambda: dsolve(eq, hint='Liouville')) + assert dsolve(f(x).diff(x) - 1/f(x)**2, hint='all')['best'] == \ + dsolve(f(x).diff(x) - 1/f(x)**2, hint='best') + assert dsolve(f(x) + f(x).diff(x) + sin(x).diff(x) + 1, f(x), + hint="1st_linear_Integral") == \ + Eq(f(x), (C1 + Integral((-sin(x).diff(x) - 1)* + exp(Integral(1, x)), x))*exp(-Integral(1, x))) + + +def test_classify_ode(): + assert classify_ode(f(x).diff(x, 2), f(x)) == \ + ( + 'nth_algebraic', + 'nth_linear_constant_coeff_homogeneous', + 'nth_linear_euler_eq_homogeneous', + 'Liouville', + '2nd_power_series_ordinary', + 'nth_algebraic_Integral', + 'Liouville_Integral', + ) + assert classify_ode(f(x), f(x)) == ('nth_algebraic', 'nth_algebraic_Integral') + assert classify_ode(Eq(f(x).diff(x), 0), f(x)) == ( + 'nth_algebraic', + 'separable', + '1st_exact', + '1st_linear', + 'Bernoulli', + '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', + '1st_homogeneous_coeff_subs_dep_div_indep', + '1st_power_series', 'lie_group', + 'nth_linear_constant_coeff_homogeneous', + 'nth_linear_euler_eq_homogeneous', + 'nth_algebraic_Integral', + 'separable_Integral', + '1st_exact_Integral', + '1st_linear_Integral', + 'Bernoulli_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral') + assert classify_ode(f(x).diff(x)**2, f(x)) == ('factorable', + 'nth_algebraic', + 'separable', + '1st_exact', + '1st_linear', + 'Bernoulli', + '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', + '1st_homogeneous_coeff_subs_dep_div_indep', + '1st_power_series', + 'lie_group', + 'nth_linear_euler_eq_homogeneous', + 'nth_algebraic_Integral', + 'separable_Integral', + '1st_exact_Integral', + '1st_linear_Integral', + 'Bernoulli_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral') + # issue 4749: f(x) should be cleared from highest derivative before classifying + a = classify_ode(Eq(f(x).diff(x) + f(x), x), f(x)) + b = classify_ode(f(x).diff(x)*f(x) + f(x)*f(x) - x*f(x), f(x)) + c = classify_ode(f(x).diff(x)/f(x) + f(x)/f(x) - x/f(x), f(x)) + assert a == ('1st_exact', + '1st_linear', + 'Bernoulli', + 'almost_linear', + '1st_power_series', "lie_group", + 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + '1st_exact_Integral', + '1st_linear_Integral', + 'Bernoulli_Integral', + 'almost_linear_Integral', + 'nth_linear_constant_coeff_variation_of_parameters_Integral') + assert b == ('factorable', + '1st_linear', + 'Bernoulli', + '1st_power_series', + 'lie_group', + 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + '1st_linear_Integral', + 'Bernoulli_Integral', + 'nth_linear_constant_coeff_variation_of_parameters_Integral') + assert c == ('factorable', + '1st_linear', + 'Bernoulli', + '1st_power_series', + 'lie_group', + 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + '1st_linear_Integral', + 'Bernoulli_Integral', + 'nth_linear_constant_coeff_variation_of_parameters_Integral') + + assert classify_ode( + 2*x*f(x)*f(x).diff(x) + (1 + x)*f(x)**2 - exp(x), f(x) + ) == ('factorable', '1st_exact', 'Bernoulli', 'almost_linear', 'lie_group', + '1st_exact_Integral', 'Bernoulli_Integral', 'almost_linear_Integral') + assert 'Riccati_special_minus2' in \ + classify_ode(2*f(x).diff(x) + f(x)**2 - f(x)/x + 3*x**(-2), f(x)) + raises(ValueError, lambda: classify_ode(x + f(x, y).diff(x).diff( + y), f(x, y))) + # issue 5176 + k = Symbol('k') + assert classify_ode(f(x).diff(x)/(k*f(x) + k*x*f(x)) + 2*f(x)/(k*f(x) + + k*x*f(x)) + x*f(x).diff(x)/(k*f(x) + k*x*f(x)) + z, f(x)) == \ + ('factorable', 'separable', '1st_exact', '1st_linear', 'Bernoulli', + '1st_power_series', 'lie_group', 'separable_Integral', '1st_exact_Integral', + '1st_linear_Integral', 'Bernoulli_Integral') + # preprocessing + ans = ('factorable', 'nth_algebraic', 'separable', '1st_exact', '1st_linear', 'Bernoulli', + '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', + '1st_homogeneous_coeff_subs_dep_div_indep', + '1st_power_series', 'lie_group', + 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + 'nth_linear_euler_eq_nonhomogeneous_variation_of_parameters', + 'nth_algebraic_Integral', + 'separable_Integral', '1st_exact_Integral', + '1st_linear_Integral', + 'Bernoulli_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral', + 'nth_linear_constant_coeff_variation_of_parameters_Integral', + 'nth_linear_euler_eq_nonhomogeneous_variation_of_parameters_Integral') + # w/o f(x) given + assert classify_ode(diff(f(x) + x, x) + diff(f(x), x)) == ans + # w/ f(x) and prep=True + assert classify_ode(diff(f(x) + x, x) + diff(f(x), x), f(x), + prep=True) == ans + + assert classify_ode(Eq(2*x**3*f(x).diff(x), 0), f(x)) == \ + ('factorable', 'nth_algebraic', 'separable', '1st_exact', + '1st_linear', 'Bernoulli', '1st_power_series', + 'lie_group', 'nth_linear_euler_eq_homogeneous', + 'nth_algebraic_Integral', 'separable_Integral', '1st_exact_Integral', + '1st_linear_Integral', 'Bernoulli_Integral') + + + assert classify_ode(Eq(2*f(x)**3*f(x).diff(x), 0), f(x)) == \ + ('factorable', 'nth_algebraic', 'separable', '1st_exact', '1st_linear', + 'Bernoulli', '1st_power_series', 'lie_group', 'nth_algebraic_Integral', + 'separable_Integral', '1st_exact_Integral', '1st_linear_Integral', + 'Bernoulli_Integral') + # test issue 13864 + assert classify_ode(Eq(diff(f(x), x) - f(x)**x, 0), f(x)) == \ + ('1st_power_series', 'lie_group') + assert isinstance(classify_ode(Eq(f(x), 5), f(x), dict=True), dict) + + #This is for new behavior of classify_ode when called internally with default, It should + # return the first hint which matches therefore, 'ordered_hints' key will not be there. + assert sorted(classify_ode(Eq(f(x).diff(x), 0), f(x), dict=True).keys()) == \ + ['default', 'nth_linear_constant_coeff_homogeneous', 'order'] + a = classify_ode(2*x*f(x)*f(x).diff(x) + (1 + x)*f(x)**2 - exp(x), f(x), dict=True, hint='Bernoulli') + assert sorted(a.keys()) == ['Bernoulli', 'Bernoulli_Integral', 'default', 'order', 'ordered_hints'] + + # test issue 22155 + a = classify_ode(f(x).diff(x) - exp(f(x) - x), f(x)) + assert a == ('separable', + '1st_exact', '1st_power_series', + 'lie_group', 'separable_Integral', + '1st_exact_Integral') + + +def test_classify_ode_ics(): + # Dummy + eq = f(x).diff(x, x) - f(x) + + # Not f(0) or f'(0) + ics = {x: 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + + ############################ + # f(0) type (AppliedUndef) # + ############################ + + + # Wrong function + ics = {g(0): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Contains x + ics = {f(x): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Too many args + ics = {f(0, 0): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # point contains x + ics = {f(0): f(x)} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Does not raise + ics = {f(0): f(0)} + classify_ode(eq, f(x), ics=ics) + + # Does not raise + ics = {f(0): 1} + classify_ode(eq, f(x), ics=ics) + + + ##################### + # f'(0) type (Subs) # + ##################### + + # Wrong function + ics = {g(x).diff(x).subs(x, 0): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Contains x + ics = {f(y).diff(y).subs(y, x): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Wrong variable + ics = {f(y).diff(y).subs(y, 0): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Too many args + ics = {f(x, y).diff(x).subs(x, 0): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Derivative wrt wrong vars + ics = {Derivative(f(x), x, y).subs(x, 0): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # point contains x + ics = {f(x).diff(x).subs(x, 0): f(x)} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Does not raise + ics = {f(x).diff(x).subs(x, 0): f(x).diff(x).subs(x, 0)} + classify_ode(eq, f(x), ics=ics) + + # Does not raise + ics = {f(x).diff(x).subs(x, 0): 1} + classify_ode(eq, f(x), ics=ics) + + ########################### + # f'(y) type (Derivative) # + ########################### + + # Wrong function + ics = {g(x).diff(x).subs(x, y): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Contains x + ics = {f(y).diff(y).subs(y, x): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Too many args + ics = {f(x, y).diff(x).subs(x, y): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Derivative wrt wrong vars + ics = {Derivative(f(x), x, z).subs(x, y): 1} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # point contains x + ics = {f(x).diff(x).subs(x, y): f(x)} + raises(ValueError, lambda: classify_ode(eq, f(x), ics=ics)) + + # Does not raise + ics = {f(x).diff(x).subs(x, 0): f(0)} + classify_ode(eq, f(x), ics=ics) + + # Does not raise + ics = {f(x).diff(x).subs(x, y): 1} + classify_ode(eq, f(x), ics=ics) + +def test_classify_sysode(): + # Here x is assumed to be x(t) and y as y(t) for simplicity. + # Similarly diff(x,t) and diff(y,y) is assumed to be x1 and y1 respectively. + k, l, m, n = symbols('k, l, m, n', Integer=True) + k1, k2, k3, l1, l2, l3, m1, m2, m3 = symbols('k1, k2, k3, l1, l2, l3, m1, m2, m3', Integer=True) + P, Q, R, p, q, r = symbols('P, Q, R, p, q, r', cls=Function) + P1, P2, P3, Q1, Q2, R1, R2 = symbols('P1, P2, P3, Q1, Q2, R1, R2', cls=Function) + x, y, z = symbols('x, y, z', cls=Function) + t = symbols('t') + x1 = diff(x(t),t) + y1 = diff(y(t),t) + + eq6 = (Eq(x1, exp(k*x(t))*P(x(t),y(t))), Eq(y1,r(y(t))*P(x(t),y(t)))) + sol6 = {'no_of_equation': 2, 'func_coeff': {(0, x(t), 0): 0, (1, x(t), 1): 0, (0, x(t), 1): 1, (1, y(t), 0): 0, \ + (1, x(t), 0): 0, (0, y(t), 1): 0, (0, y(t), 0): 0, (1, y(t), 1): 1}, 'type_of_equation': 'type2', 'func': \ + [x(t), y(t)], 'is_linear': False, 'eq': [-P(x(t), y(t))*exp(k*x(t)) + Derivative(x(t), t), -P(x(t), \ + y(t))*r(y(t)) + Derivative(y(t), t)], 'order': {y(t): 1, x(t): 1}} + assert classify_sysode(eq6) == sol6 + + eq7 = (Eq(x1, x(t)**2+y(t)/x(t)), Eq(y1, x(t)/y(t))) + sol7 = {'no_of_equation': 2, 'func_coeff': {(0, x(t), 0): 0, (1, x(t), 1): 0, (0, x(t), 1): 1, (1, y(t), 0): 0, \ + (1, x(t), 0): -1/y(t), (0, y(t), 1): 0, (0, y(t), 0): -1/x(t), (1, y(t), 1): 1}, 'type_of_equation': 'type3', \ + 'func': [x(t), y(t)], 'is_linear': False, 'eq': [-x(t)**2 + Derivative(x(t), t) - y(t)/x(t), -x(t)/y(t) + \ + Derivative(y(t), t)], 'order': {y(t): 1, x(t): 1}} + assert classify_sysode(eq7) == sol7 + + eq8 = (Eq(x1, P1(x(t))*Q1(y(t))*R(x(t),y(t),t)), Eq(y1, P1(x(t))*Q1(y(t))*R(x(t),y(t),t))) + sol8 = {'func': [x(t), y(t)], 'is_linear': False, 'type_of_equation': 'type4', 'eq': \ + [-P1(x(t))*Q1(y(t))*R(x(t), y(t), t) + Derivative(x(t), t), -P1(x(t))*Q1(y(t))*R(x(t), y(t), t) + \ + Derivative(y(t), t)], 'func_coeff': {(0, y(t), 1): 0, (1, y(t), 1): 1, (1, x(t), 1): 0, (0, y(t), 0): 0, \ + (1, x(t), 0): 0, (0, x(t), 0): 0, (1, y(t), 0): 0, (0, x(t), 1): 1}, 'order': {y(t): 1, x(t): 1}, 'no_of_equation': 2} + assert classify_sysode(eq8) == sol8 + + eq11 = (Eq(x1,x(t)*y(t)**3), Eq(y1,y(t)**5)) + sol11 = {'no_of_equation': 2, 'func_coeff': {(0, x(t), 0): -y(t)**3, (1, x(t), 1): 0, (0, x(t), 1): 1, \ + (1, y(t), 0): 0, (1, x(t), 0): 0, (0, y(t), 1): 0, (0, y(t), 0): 0, (1, y(t), 1): 1}, 'type_of_equation': \ + 'type1', 'func': [x(t), y(t)], 'is_linear': False, 'eq': [-x(t)*y(t)**3 + Derivative(x(t), t), \ + -y(t)**5 + Derivative(y(t), t)], 'order': {y(t): 1, x(t): 1}} + assert classify_sysode(eq11) == sol11 + + eq13 = (Eq(x1,x(t)*y(t)*sin(t)**2), Eq(y1,y(t)**2*sin(t)**2)) + sol13 = {'no_of_equation': 2, 'func_coeff': {(0, x(t), 0): -y(t)*sin(t)**2, (1, x(t), 1): 0, (0, x(t), 1): 1, \ + (1, y(t), 0): 0, (1, x(t), 0): 0, (0, y(t), 1): 0, (0, y(t), 0): -x(t)*sin(t)**2, (1, y(t), 1): 1}, \ + 'type_of_equation': 'type4', 'func': [x(t), y(t)], 'is_linear': False, 'eq': [-x(t)*y(t)*sin(t)**2 + \ + Derivative(x(t), t), -y(t)**2*sin(t)**2 + Derivative(y(t), t)], 'order': {y(t): 1, x(t): 1}} + assert classify_sysode(eq13) == sol13 + + +def test_solve_ics(): + # Basic tests that things work from dsolve. + assert dsolve(f(x).diff(x) - 1/f(x), f(x), ics={f(1): 2}) == \ + Eq(f(x), sqrt(2 * x + 2)) + assert dsolve(f(x).diff(x) - f(x), f(x), ics={f(0): 1}) == Eq(f(x), exp(x)) + assert dsolve(f(x).diff(x) - f(x), f(x), ics={f(x).diff(x).subs(x, 0): 1}) == Eq(f(x), exp(x)) + assert dsolve(f(x).diff(x, x) + f(x), f(x), ics={f(0): 1, + f(x).diff(x).subs(x, 0): 1}) == Eq(f(x), sin(x) + cos(x)) + assert dsolve([f(x).diff(x) - f(x) + g(x), g(x).diff(x) - g(x) - f(x)], + [f(x), g(x)], ics={f(0): 1, g(0): 0}) == [Eq(f(x), exp(x)*cos(x)), Eq(g(x), exp(x)*sin(x))] + + # Test cases where dsolve returns two solutions. + eq = (x**2*f(x)**2 - x).diff(x) + assert dsolve(eq, f(x), ics={f(1): 0}) == [Eq(f(x), + -sqrt(x - 1)/x), Eq(f(x), sqrt(x - 1)/x)] + assert dsolve(eq, f(x), ics={f(x).diff(x).subs(x, 1): 0}) == [Eq(f(x), + -sqrt(x - S.Half)/x), Eq(f(x), sqrt(x - S.Half)/x)] + + eq = cos(f(x)) - (x*sin(f(x)) - f(x)**2)*f(x).diff(x) + assert dsolve(eq, f(x), + ics={f(0):1}, hint='1st_exact', simplify=False) == Eq(x*cos(f(x)) + f(x)**3/3, Rational(1, 3)) + assert dsolve(eq, f(x), + ics={f(0):1}, hint='1st_exact', simplify=True) == Eq(x*cos(f(x)) + f(x)**3/3, Rational(1, 3)) + + assert solve_ics([Eq(f(x), C1*exp(x))], [f(x)], [C1], {f(0): 1}) == {C1: 1} + assert solve_ics([Eq(f(x), C1*sin(x) + C2*cos(x))], [f(x)], [C1, C2], + {f(0): 1, f(pi/2): 1}) == {C1: 1, C2: 1} + + assert solve_ics([Eq(f(x), C1*sin(x) + C2*cos(x))], [f(x)], [C1, C2], + {f(0): 1, f(x).diff(x).subs(x, 0): 1}) == {C1: 1, C2: 1} + + assert solve_ics([Eq(f(x), C1*sin(x) + C2*cos(x))], [f(x)], [C1, C2], {f(0): 1}) == \ + {C2: 1} + + # Some more complicated tests Refer to PR #16098 + + assert set(dsolve(f(x).diff(x)*(f(x).diff(x, 2)-x), ics={f(0):0, f(x).diff(x).subs(x, 1):0})) == \ + {Eq(f(x), 0), Eq(f(x), x ** 3 / 6 - x / 2)} + assert set(dsolve(f(x).diff(x)*(f(x).diff(x, 2)-x), ics={f(0):0})) == \ + {Eq(f(x), 0), Eq(f(x), C2*x + x**3/6)} + + K, r, f0 = symbols('K r f0') + sol = Eq(f(x), K*f0*exp(r*x)/((-K + f0)*(f0*exp(r*x)/(-K + f0) - 1))) + assert (dsolve(Eq(f(x).diff(x), r * f(x) * (1 - f(x) / K)), f(x), ics={f(0): f0})) == sol + + + #Order dependent issues Refer to PR #16098 + assert set(dsolve(f(x).diff(x)*(f(x).diff(x, 2)-x), ics={f(x).diff(x).subs(x,0):0, f(0):0})) == \ + {Eq(f(x), 0), Eq(f(x), x ** 3 / 6)} + assert set(dsolve(f(x).diff(x)*(f(x).diff(x, 2)-x), ics={f(0):0, f(x).diff(x).subs(x,0):0})) == \ + {Eq(f(x), 0), Eq(f(x), x ** 3 / 6)} + + # XXX: Ought to be ValueError + raises(ValueError, lambda: solve_ics([Eq(f(x), C1*sin(x) + C2*cos(x))], [f(x)], [C1, C2], {f(0): 1, f(pi): 1})) + + # Degenerate case. f'(0) is identically 0. + raises(ValueError, lambda: solve_ics([Eq(f(x), sqrt(C1 - x**2))], [f(x)], [C1], {f(x).diff(x).subs(x, 0): 0})) + + EI, q, L = symbols('EI q L') + + # eq = Eq(EI*diff(f(x), x, 4), q) + sols = [Eq(f(x), C1 + C2*x + C3*x**2 + C4*x**3 + q*x**4/(24*EI))] + funcs = [f(x)] + constants = [C1, C2, C3, C4] + # Test both cases, Derivative (the default from f(x).diff(x).subs(x, L)), + # and Subs + ics1 = {f(0): 0, + f(x).diff(x).subs(x, 0): 0, + f(L).diff(L, 2): 0, + f(L).diff(L, 3): 0} + ics2 = {f(0): 0, + f(x).diff(x).subs(x, 0): 0, + Subs(f(x).diff(x, 2), x, L): 0, + Subs(f(x).diff(x, 3), x, L): 0} + + solved_constants1 = solve_ics(sols, funcs, constants, ics1) + solved_constants2 = solve_ics(sols, funcs, constants, ics2) + assert solved_constants1 == solved_constants2 == { + C1: 0, + C2: 0, + C3: L**2*q/(4*EI), + C4: -L*q/(6*EI)} + + # Allow the ics to refer to f + ics = {f(0): f(0)} + assert dsolve(f(x).diff(x) - f(x), f(x), ics=ics) == Eq(f(x), f(0)*exp(x)) + + ics = {f(x).diff(x).subs(x, 0): f(x).diff(x).subs(x, 0), f(0): f(0)} + assert dsolve(f(x).diff(x, x) + f(x), f(x), ics=ics) == \ + Eq(f(x), f(0)*cos(x) + f(x).diff(x).subs(x, 0)*sin(x)) + +def test_ode_order(): + f = Function('f') + g = Function('g') + x = Symbol('x') + assert ode_order(3*x*exp(f(x)), f(x)) == 0 + assert ode_order(x*diff(f(x), x) + 3*x*f(x) - sin(x)/x, f(x)) == 1 + assert ode_order(x**2*f(x).diff(x, x) + x*diff(f(x), x) - f(x), f(x)) == 2 + assert ode_order(diff(x*exp(f(x)), x, x), f(x)) == 2 + assert ode_order(diff(x*diff(x*exp(f(x)), x, x), x), f(x)) == 3 + assert ode_order(diff(f(x), x, x), g(x)) == 0 + assert ode_order(diff(f(x), x, x)*diff(g(x), x), f(x)) == 2 + assert ode_order(diff(f(x), x, x)*diff(g(x), x), g(x)) == 1 + assert ode_order(diff(x*diff(x*exp(f(x)), x, x), x), g(x)) == 0 + # issue 5835: ode_order has to also work for unevaluated derivatives + # (ie, without using doit()). + assert ode_order(Derivative(x*f(x), x), f(x)) == 1 + assert ode_order(x*sin(Derivative(x*f(x)**2, x, x)), f(x)) == 2 + assert ode_order(Derivative(x*Derivative(x*exp(f(x)), x, x), x), g(x)) == 0 + assert ode_order(Derivative(f(x), x, x), g(x)) == 0 + assert ode_order(Derivative(x*exp(f(x)), x, x), f(x)) == 2 + assert ode_order(Derivative(f(x), x, x)*Derivative(g(x), x), g(x)) == 1 + assert ode_order(Derivative(x*Derivative(f(x), x, x), x), f(x)) == 3 + assert ode_order( + x*sin(Derivative(x*Derivative(f(x), x)**2, x, x)), f(x)) == 3 + + +def test_homogeneous_order(): + assert homogeneous_order(exp(y/x) + tan(y/x), x, y) == 0 + assert homogeneous_order(x**2 + sin(x)*cos(y), x, y) is None + assert homogeneous_order(x - y - x*sin(y/x), x, y) == 1 + assert homogeneous_order((x*y + sqrt(x**4 + y**4) + x**2*(log(x) - log(y)))/ + (pi*x**Rational(2, 3)*sqrt(y)**3), x, y) == Rational(-1, 6) + assert homogeneous_order(y/x*cos(y/x) - x/y*sin(y/x) + cos(y/x), x, y) == 0 + assert homogeneous_order(f(x), x, f(x)) == 1 + assert homogeneous_order(f(x)**2, x, f(x)) == 2 + assert homogeneous_order(x*y*z, x, y) == 2 + assert homogeneous_order(x*y*z, x, y, z) == 3 + assert homogeneous_order(x**2*f(x)/sqrt(x**2 + f(x)**2), f(x)) is None + assert homogeneous_order(f(x, y)**2, x, f(x, y), y) == 2 + assert homogeneous_order(f(x, y)**2, x, f(x), y) is None + assert homogeneous_order(f(x, y)**2, x, f(x, y)) is None + assert homogeneous_order(f(y, x)**2, x, y, f(x, y)) is None + assert homogeneous_order(f(y), f(x), x) is None + assert homogeneous_order(-f(x)/x + 1/sin(f(x)/ x), f(x), x) == 0 + assert homogeneous_order(log(1/y) + log(x**2), x, y) is None + assert homogeneous_order(log(1/y) + log(x), x, y) == 0 + assert homogeneous_order(log(x/y), x, y) == 0 + assert homogeneous_order(2*log(1/y) + 2*log(x), x, y) == 0 + a = Symbol('a') + assert homogeneous_order(a*log(1/y) + a*log(x), x, y) == 0 + assert homogeneous_order(f(x).diff(x), x, y) is None + assert homogeneous_order(-f(x).diff(x) + x, x, y) is None + assert homogeneous_order(O(x), x, y) is None + assert homogeneous_order(x + O(x**2), x, y) is None + assert homogeneous_order(x**pi, x) == pi + assert homogeneous_order(x**x, x) is None + raises(ValueError, lambda: homogeneous_order(x*y)) + + +@XFAIL +def test_noncircularized_real_imaginary_parts(): + # If this passes, lines numbered 3878-3882 (at the time of this commit) + # of sympy/solvers/ode.py for nth_linear_constant_coeff_homogeneous + # should be removed. + y = sqrt(1+x) + i, r = im(y), re(y) + assert not (i.has(atan2) and r.has(atan2)) + + +def test_collect_respecting_exponentials(): + # If this test passes, lines 1306-1311 (at the time of this commit) + # of sympy/solvers/ode.py should be removed. + sol = 1 + exp(x/2) + assert sol == collect( sol, exp(x/3)) + + +def test_undetermined_coefficients_match(): + assert _undetermined_coefficients_match(g(x), x) == {'test': False} + assert _undetermined_coefficients_match(sin(2*x + sqrt(5)), x) == \ + {'test': True, 'trialset': + {cos(2*x + sqrt(5)), sin(2*x + sqrt(5))}} + assert _undetermined_coefficients_match(sin(x)*cos(x), x) == \ + {'test': False} + s = {cos(x), x*cos(x), x**2*cos(x), x**2*sin(x), x*sin(x), sin(x)} + assert _undetermined_coefficients_match(sin(x)*(x**2 + x + 1), x) == \ + {'test': True, 'trialset': s} + assert _undetermined_coefficients_match( + sin(x)*x**2 + sin(x)*x + sin(x), x) == {'test': True, 'trialset': s} + assert _undetermined_coefficients_match( + exp(2*x)*sin(x)*(x**2 + x + 1), x + ) == { + 'test': True, 'trialset': {exp(2*x)*sin(x), x**2*exp(2*x)*sin(x), + cos(x)*exp(2*x), x**2*cos(x)*exp(2*x), x*cos(x)*exp(2*x), + x*exp(2*x)*sin(x)}} + assert _undetermined_coefficients_match(1/sin(x), x) == {'test': False} + assert _undetermined_coefficients_match(log(x), x) == {'test': False} + assert _undetermined_coefficients_match(2**(x)*(x**2 + x + 1), x) == \ + {'test': True, 'trialset': {2**x, x*2**x, x**2*2**x}} + assert _undetermined_coefficients_match(x**y, x) == {'test': False} + assert _undetermined_coefficients_match(exp(x)*exp(2*x + 1), x) == \ + {'test': True, 'trialset': {exp(1 + 3*x)}} + assert _undetermined_coefficients_match(sin(x)*(x**2 + x + 1), x) == \ + {'test': True, 'trialset': {x*cos(x), x*sin(x), x**2*cos(x), + x**2*sin(x), cos(x), sin(x)}} + assert _undetermined_coefficients_match(sin(x)*(x + sin(x)), x) == \ + {'test': False} + assert _undetermined_coefficients_match(sin(x)*(x + sin(2*x)), x) == \ + {'test': False} + assert _undetermined_coefficients_match(sin(x)*tan(x), x) == \ + {'test': False} + assert _undetermined_coefficients_match( + x**2*sin(x)*exp(x) + x*sin(x) + x, x + ) == { + 'test': True, 'trialset': {x**2*cos(x)*exp(x), x, cos(x), S.One, + exp(x)*sin(x), sin(x), x*exp(x)*sin(x), x*cos(x), x*cos(x)*exp(x), + x*sin(x), cos(x)*exp(x), x**2*exp(x)*sin(x)}} + assert _undetermined_coefficients_match(4*x*sin(x - 2), x) == { + 'trialset': {x*cos(x - 2), x*sin(x - 2), cos(x - 2), sin(x - 2)}, + 'test': True, + } + assert _undetermined_coefficients_match(2**x*x, x) == \ + {'test': True, 'trialset': {2**x, x*2**x}} + assert _undetermined_coefficients_match(2**x*exp(2*x), x) == \ + {'test': True, 'trialset': {2**x*exp(2*x)}} + assert _undetermined_coefficients_match(exp(-x)/x, x) == \ + {'test': False} + # Below are from Ordinary Differential Equations, + # Tenenbaum and Pollard, pg. 231 + assert _undetermined_coefficients_match(S(4), x) == \ + {'test': True, 'trialset': {S.One}} + assert _undetermined_coefficients_match(12*exp(x), x) == \ + {'test': True, 'trialset': {exp(x)}} + assert _undetermined_coefficients_match(exp(I*x), x) == \ + {'test': True, 'trialset': {exp(I*x)}} + assert _undetermined_coefficients_match(sin(x), x) == \ + {'test': True, 'trialset': {cos(x), sin(x)}} + assert _undetermined_coefficients_match(cos(x), x) == \ + {'test': True, 'trialset': {cos(x), sin(x)}} + assert _undetermined_coefficients_match(8 + 6*exp(x) + 2*sin(x), x) == \ + {'test': True, 'trialset': {S.One, cos(x), sin(x), exp(x)}} + assert _undetermined_coefficients_match(x**2, x) == \ + {'test': True, 'trialset': {S.One, x, x**2}} + assert _undetermined_coefficients_match(9*x*exp(x) + exp(-x), x) == \ + {'test': True, 'trialset': {x*exp(x), exp(x), exp(-x)}} + assert _undetermined_coefficients_match(2*exp(2*x)*sin(x), x) == \ + {'test': True, 'trialset': {exp(2*x)*sin(x), cos(x)*exp(2*x)}} + assert _undetermined_coefficients_match(x - sin(x), x) == \ + {'test': True, 'trialset': {S.One, x, cos(x), sin(x)}} + assert _undetermined_coefficients_match(x**2 + 2*x, x) == \ + {'test': True, 'trialset': {S.One, x, x**2}} + assert _undetermined_coefficients_match(4*x*sin(x), x) == \ + {'test': True, 'trialset': {x*cos(x), x*sin(x), cos(x), sin(x)}} + assert _undetermined_coefficients_match(x*sin(2*x), x) == \ + {'test': True, 'trialset': + {x*cos(2*x), x*sin(2*x), cos(2*x), sin(2*x)}} + assert _undetermined_coefficients_match(x**2*exp(-x), x) == \ + {'test': True, 'trialset': {x*exp(-x), x**2*exp(-x), exp(-x)}} + assert _undetermined_coefficients_match(2*exp(-x) - x**2*exp(-x), x) == \ + {'test': True, 'trialset': {x*exp(-x), x**2*exp(-x), exp(-x)}} + assert _undetermined_coefficients_match(exp(-2*x) + x**2, x) == \ + {'test': True, 'trialset': {S.One, x, x**2, exp(-2*x)}} + assert _undetermined_coefficients_match(x*exp(-x), x) == \ + {'test': True, 'trialset': {x*exp(-x), exp(-x)}} + assert _undetermined_coefficients_match(x + exp(2*x), x) == \ + {'test': True, 'trialset': {S.One, x, exp(2*x)}} + assert _undetermined_coefficients_match(sin(x) + exp(-x), x) == \ + {'test': True, 'trialset': {cos(x), sin(x), exp(-x)}} + assert _undetermined_coefficients_match(exp(x), x) == \ + {'test': True, 'trialset': {exp(x)}} + # converted from sin(x)**2 + assert _undetermined_coefficients_match(S.Half - cos(2*x)/2, x) == \ + {'test': True, 'trialset': {S.One, cos(2*x), sin(2*x)}} + # converted from exp(2*x)*sin(x)**2 + assert _undetermined_coefficients_match( + exp(2*x)*(S.Half + cos(2*x)/2), x + ) == { + 'test': True, 'trialset': {exp(2*x)*sin(2*x), cos(2*x)*exp(2*x), + exp(2*x)}} + assert _undetermined_coefficients_match(2*x + sin(x) + cos(x), x) == \ + {'test': True, 'trialset': {S.One, x, cos(x), sin(x)}} + # converted from sin(2*x)*sin(x) + assert _undetermined_coefficients_match(cos(x)/2 - cos(3*x)/2, x) == \ + {'test': True, 'trialset': {cos(x), cos(3*x), sin(x), sin(3*x)}} + assert _undetermined_coefficients_match(cos(x**2), x) == {'test': False} + assert _undetermined_coefficients_match(2**(x**2), x) == {'test': False} + + +def test_issue_4785_22462(): + from sympy.abc import A + eq = x + A*(x + diff(f(x), x) + f(x)) + diff(f(x), x) + f(x) + 2 + assert classify_ode(eq, f(x)) == ('factorable', '1st_exact', '1st_linear', + 'Bernoulli', 'almost_linear', '1st_power_series', 'lie_group', + 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + '1st_exact_Integral', '1st_linear_Integral', 'Bernoulli_Integral', + 'almost_linear_Integral', + 'nth_linear_constant_coeff_variation_of_parameters_Integral') + # issue 4864 + eq = (x**2 + f(x)**2)*f(x).diff(x) - 2*x*f(x) + assert classify_ode(eq, f(x)) == ('factorable', '1st_exact', + '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', + '1st_homogeneous_coeff_subs_dep_div_indep', + '1st_power_series', + 'lie_group', '1st_exact_Integral', + '1st_homogeneous_coeff_subs_indep_div_dep_Integral', + '1st_homogeneous_coeff_subs_dep_div_indep_Integral') + + +def test_issue_4825(): + raises(ValueError, lambda: dsolve(f(x, y).diff(x) - y*f(x, y), f(x))) + assert classify_ode(f(x, y).diff(x) - y*f(x, y), f(x), dict=True) == \ + {'order': 0, 'default': None, 'ordered_hints': ()} + # See also issue 3793, test Z13. + raises(ValueError, lambda: dsolve(f(x).diff(x), f(y))) + assert classify_ode(f(x).diff(x), f(y), dict=True) == \ + {'order': 0, 'default': None, 'ordered_hints': ()} + + +def test_constant_renumber_order_issue_5308(): + from sympy.utilities.iterables import variations + + assert constant_renumber(C1*x + C2*y) == \ + constant_renumber(C1*y + C2*x) == \ + C1*x + C2*y + e = C1*(C2 + x)*(C3 + y) + for a, b, c in variations([C1, C2, C3], 3): + assert constant_renumber(a*(b + x)*(c + y)) == e + + +def test_constant_renumber(): + e1, e2, x, y = symbols("e1:3 x y") + exprs = [e2*x, e1*x + e2*y] + + assert constant_renumber(exprs[0]) == e2*x + assert constant_renumber(exprs[0], variables=[x]) == C1*x + assert constant_renumber(exprs[0], variables=[x], newconstants=[C2]) == C2*x + assert constant_renumber(exprs, variables=[x, y]) == [C1*x, C1*y + C2*x] + assert constant_renumber(exprs, variables=[x, y], newconstants=symbols("C3:5")) == [C3*x, C3*y + C4*x] + + +def test_issue_5770(): + k = Symbol("k", real=True) + t = Symbol('t') + w = Function('w') + sol = dsolve(w(t).diff(t, 6) - k**6*w(t), w(t)) + assert len([s for s in sol.free_symbols if s.name.startswith('C')]) == 6 + assert constantsimp((C1*cos(x) + C2*cos(x))*exp(x), {C1, C2}) == \ + C1*cos(x)*exp(x) + assert constantsimp(C1*cos(x) + C2*cos(x) + C3*sin(x), {C1, C2, C3}) == \ + C1*cos(x) + C3*sin(x) + assert constantsimp(exp(C1 + x), {C1}) == C1*exp(x) + assert constantsimp(x + C1 + y, {C1, y}) == C1 + x + assert constantsimp(x + C1 + Integral(x, (x, 1, 2)), {C1}) == C1 + x + + +def test_issue_5112_5430(): + assert homogeneous_order(-log(x) + acosh(x), x) is None + assert homogeneous_order(y - log(x), x, y) is None + + +def test_issue_5095(): + f = Function('f') + raises(ValueError, lambda: dsolve(f(x).diff(x)**2, f(x), 'fdsjf')) + + +def test_homogeneous_function(): + f = Function('f') + eq1 = tan(x + f(x)) + eq2 = sin((3*x)/(4*f(x))) + eq3 = cos(x*f(x)*Rational(3, 4)) + eq4 = log((3*x + 4*f(x))/(5*f(x) + 7*x)) + eq5 = exp((2*x**2)/(3*f(x)**2)) + eq6 = log((3*x + 4*f(x))/(5*f(x) + 7*x) + exp((2*x**2)/(3*f(x)**2))) + eq7 = sin((3*x)/(5*f(x) + x**2)) + assert homogeneous_order(eq1, x, f(x)) == None + assert homogeneous_order(eq2, x, f(x)) == 0 + assert homogeneous_order(eq3, x, f(x)) == None + assert homogeneous_order(eq4, x, f(x)) == 0 + assert homogeneous_order(eq5, x, f(x)) == 0 + assert homogeneous_order(eq6, x, f(x)) == 0 + assert homogeneous_order(eq7, x, f(x)) == None + + +def test_linear_coeff_match(): + n, d = z*(2*x + 3*f(x) + 5), z*(7*x + 9*f(x) + 11) + rat = n/d + eq1 = sin(rat) + cos(rat.expand()) + obj1 = LinearCoefficients(eq1) + eq2 = rat + obj2 = LinearCoefficients(eq2) + eq3 = log(sin(rat)) + obj3 = LinearCoefficients(eq3) + ans = (4, Rational(-13, 3)) + assert obj1._linear_coeff_match(eq1, f(x)) == ans + assert obj2._linear_coeff_match(eq2, f(x)) == ans + assert obj3._linear_coeff_match(eq3, f(x)) == ans + + # no c + eq4 = (3*x)/f(x) + obj4 = LinearCoefficients(eq4) + # not x and f(x) + eq5 = (3*x + 2)/x + obj5 = LinearCoefficients(eq5) + # denom will be zero + eq6 = (3*x + 2*f(x) + 1)/(3*x + 2*f(x) + 5) + obj6 = LinearCoefficients(eq6) + # not rational coefficient + eq7 = (3*x + 2*f(x) + sqrt(2))/(3*x + 2*f(x) + 5) + obj7 = LinearCoefficients(eq7) + assert obj4._linear_coeff_match(eq4, f(x)) is None + assert obj5._linear_coeff_match(eq5, f(x)) is None + assert obj6._linear_coeff_match(eq6, f(x)) is None + assert obj7._linear_coeff_match(eq7, f(x)) is None + + +def test_constantsimp_take_problem(): + c = exp(C1) + 2 + assert len(Poly(constantsimp(exp(C1) + c + c*x, [C1])).gens) == 2 + + +def test_series(): + C1 = Symbol("C1") + eq = f(x).diff(x) - f(x) + sol = Eq(f(x), C1 + C1*x + C1*x**2/2 + C1*x**3/6 + C1*x**4/24 + + C1*x**5/120 + O(x**6)) + assert dsolve(eq, hint='1st_power_series') == sol + assert checkodesol(eq, sol, order=1)[0] + + eq = f(x).diff(x) - x*f(x) + sol = Eq(f(x), C1*x**4/8 + C1*x**2/2 + C1 + O(x**6)) + assert dsolve(eq, hint='1st_power_series') == sol + assert checkodesol(eq, sol, order=1)[0] + + eq = f(x).diff(x) - sin(x*f(x)) + sol = Eq(f(x), (x - 2)**2*(1+ sin(4))*cos(4) + (x - 2)*sin(4) + 2 + O(x**3)) + assert dsolve(eq, hint='1st_power_series', ics={f(2): 2}, n=3) == sol + # FIXME: The solution here should be O((x-2)**3) so is incorrect + #assert checkodesol(eq, sol, order=1)[0] + + +@slow +def test_2nd_power_series_ordinary(): + C1, C2 = symbols("C1 C2") + + eq = f(x).diff(x, 2) - x*f(x) + assert classify_ode(eq) == ('2nd_linear_airy', '2nd_power_series_ordinary') + sol = Eq(f(x), C2*(x**3/6 + 1) + C1*x*(x**3/12 + 1) + O(x**6)) + assert dsolve(eq, hint='2nd_power_series_ordinary') == sol + assert checkodesol(eq, sol) == (True, 0) + + sol = Eq(f(x), C2*((x + 2)**4/6 + (x + 2)**3/6 - (x + 2)**2 + 1) + + C1*(x + (x + 2)**4/12 - (x + 2)**3/3 + S(2)) + + O(x**6)) + assert dsolve(eq, hint='2nd_power_series_ordinary', x0=-2) == sol + # FIXME: Solution should be O((x+2)**6) + # assert checkodesol(eq, sol) == (True, 0) + + sol = Eq(f(x), C2*x + C1 + O(x**2)) + assert dsolve(eq, hint='2nd_power_series_ordinary', n=2) == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = (1 + x**2)*(f(x).diff(x, 2)) + 2*x*(f(x).diff(x)) -2*f(x) + assert classify_ode(eq) == ('factorable', '2nd_hypergeometric', '2nd_hypergeometric_Integral', + '2nd_power_series_ordinary') + + sol = Eq(f(x), C2*(-x**4/3 + x**2 + 1) + C1*x + O(x**6)) + assert dsolve(eq, hint='2nd_power_series_ordinary') == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = f(x).diff(x, 2) + x*(f(x).diff(x)) + f(x) + assert classify_ode(eq) == ('factorable', '2nd_power_series_ordinary',) + sol = Eq(f(x), C2*(x**4/8 - x**2/2 + 1) + C1*x*(-x**2/3 + 1) + O(x**6)) + assert dsolve(eq) == sol + # FIXME: checkodesol fails for this solution... + # assert checkodesol(eq, sol) == (True, 0) + + eq = f(x).diff(x, 2) + f(x).diff(x) - x*f(x) + assert classify_ode(eq) == ('2nd_power_series_ordinary',) + sol = Eq(f(x), C2*(-x**4/24 + x**3/6 + 1) + + C1*x*(x**3/24 + x**2/6 - x/2 + 1) + O(x**6)) + assert dsolve(eq) == sol + # FIXME: checkodesol fails for this solution... + # assert checkodesol(eq, sol) == (True, 0) + + eq = f(x).diff(x, 2) + x*f(x) + assert classify_ode(eq) == ('2nd_linear_airy', '2nd_power_series_ordinary') + sol = Eq(f(x), C2*(x**6/180 - x**3/6 + 1) + C1*x*(-x**3/12 + 1) + O(x**7)) + assert dsolve(eq, hint='2nd_power_series_ordinary', n=7) == sol + assert checkodesol(eq, sol) == (True, 0) + + +def test_2nd_power_series_regular(): + C1, C2, a = symbols("C1 C2 a") + eq = x**2*(f(x).diff(x, 2)) - 3*x*(f(x).diff(x)) + (4*x + 4)*f(x) + sol = Eq(f(x), C1*x**2*(-16*x**3/9 + 4*x**2 - 4*x + 1) + O(x**6)) + assert dsolve(eq, hint='2nd_power_series_regular') == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = 4*x**2*(f(x).diff(x, 2)) -8*x**2*(f(x).diff(x)) + (4*x**2 + + 1)*f(x) + sol = Eq(f(x), C1*sqrt(x)*(x**4/24 + x**3/6 + x**2/2 + x + 1) + O(x**6)) + assert dsolve(eq, hint='2nd_power_series_regular') == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = x**2*(f(x).diff(x, 2)) - x**2*(f(x).diff(x)) + ( + x**2 - 2)*f(x) + sol = Eq(f(x), C1*(-x**6/720 - 3*x**5/80 - x**4/8 + x**2/2 + x/2 + 1)/x + + C2*x**2*(-x**3/60 + x**2/20 + x/2 + 1) + O(x**6)) + assert dsolve(eq) == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (x**2 - Rational(1, 4))*f(x) + sol = Eq(f(x), C1*(x**4/24 - x**2/2 + 1)/sqrt(x) + + C2*sqrt(x)*(x**4/120 - x**2/6 + 1) + O(x**6)) + assert dsolve(eq, hint='2nd_power_series_regular') == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = x*f(x).diff(x, 2) + f(x).diff(x) - a*x*f(x) + sol = Eq(f(x), C1*(a**2*x**4/64 + a*x**2/4 + 1) + O(x**6)) + assert dsolve(eq, f(x), hint="2nd_power_series_regular") == sol + assert checkodesol(eq, sol) == (True, 0) + + eq = f(x).diff(x, 2) + ((1 - x)/x)*f(x).diff(x) + (a/x)*f(x) + sol = Eq(f(x), C1*(-a*x**5*(a - 4)*(a - 3)*(a - 2)*(a - 1)/14400 + \ + a*x**4*(a - 3)*(a - 2)*(a - 1)/576 - a*x**3*(a - 2)*(a - 1)/36 + \ + a*x**2*(a - 1)/4 - a*x + 1) + O(x**6)) + assert dsolve(eq, f(x), hint="2nd_power_series_regular") == sol + assert checkodesol(eq, sol) == (True, 0) + + +def test_issue_15056(): + t = Symbol('t') + C3 = Symbol('C3') + assert get_numbered_constants(Symbol('C1') * Function('C2')(t)) == C3 + + +def test_issue_15913(): + eq = -C1/x - 2*x*f(x) - f(x) + Derivative(f(x), x) + sol = C2*exp(x**2 + x) + exp(x**2 + x)*Integral(C1*exp(-x**2 - x)/x, x) + assert checkodesol(eq, sol) == (True, 0) + sol = C1 + C2*exp(-x*y) + eq = Derivative(y*f(x), x) + f(x).diff(x, 2) + assert checkodesol(eq, sol, f(x)) == (True, 0) + + +def test_issue_16146(): + raises(ValueError, lambda: dsolve([f(x).diff(x), g(x).diff(x)], [f(x), g(x), h(x)])) + raises(ValueError, lambda: dsolve([f(x).diff(x), g(x).diff(x)], [f(x)])) + + +def test_dsolve_remove_redundant_solutions(): + + eq = (f(x)-2)*f(x).diff(x) + sol = Eq(f(x), C1) + assert dsolve(eq) == sol + + eq = (f(x)-sin(x))*(f(x).diff(x, 2)) + sol = {Eq(f(x), C1 + C2*x), Eq(f(x), sin(x))} + assert set(dsolve(eq)) == sol + + eq = (f(x)**2-2*f(x)+1)*f(x).diff(x, 3) + sol = Eq(f(x), C1 + C2*x + C3*x**2) + assert dsolve(eq) == sol + + +def test_issue_13060(): + A, B = symbols("A B", cls=Function) + t = Symbol("t") + eq = [Eq(Derivative(A(t), t), A(t)*B(t)), Eq(Derivative(B(t), t), A(t)*B(t))] + sol = dsolve(eq) + assert checkodesol(eq, sol) == (True, [0, 0]) + + +def test_issue_22523(): + N, s = symbols('N s') + rho = Function('rho') + # intentionally use 4.0 to confirm issue with nfloat + # works here + eqn = 4.0*N*sqrt(N - 1)*rho(s) + (4*s**2*(N - 1) + (N - 2*s*(N - 1))**2 + )*Derivative(rho(s), (s, 2)) + match = classify_ode(eqn, dict=True, hint='all') + assert match['2nd_power_series_ordinary']['terms'] == 5 + C1, C2 = symbols('C1,C2') + sol = dsolve(eqn, hint='2nd_power_series_ordinary') + # there is no r(2.0) in this result + assert filldedent(sol) == filldedent(str(''' + Eq(rho(s), C2*(1 - 4.0*s**4*sqrt(N - 1.0)/N + 0.666666666666667*s**4/N + - 2.66666666666667*s**3*sqrt(N - 1.0)/N - 2.0*s**2*sqrt(N - 1.0)/N + + 9.33333333333333*s**4*sqrt(N - 1.0)/N**2 - 0.666666666666667*s**4/N**2 + + 2.66666666666667*s**3*sqrt(N - 1.0)/N**2 - + 5.33333333333333*s**4*sqrt(N - 1.0)/N**3) + C1*s*(1.0 - + 1.33333333333333*s**3*sqrt(N - 1.0)/N - 0.666666666666667*s**2*sqrt(N + - 1.0)/N + 1.33333333333333*s**3*sqrt(N - 1.0)/N**2) + O(s**6))''')) + + +def test_issue_22604(): + x1, x2 = symbols('x1, x2', cls = Function) + t, k1, k2, m1, m2 = symbols('t k1 k2 m1 m2', real = True) + k1, k2, m1, m2 = 1, 1, 1, 1 + eq1 = Eq(m1*diff(x1(t), t, 2) + k1*x1(t) - k2*(x2(t) - x1(t)), 0) + eq2 = Eq(m2*diff(x2(t), t, 2) + k2*(x2(t) - x1(t)), 0) + eqs = [eq1, eq2] + [x1sol, x2sol] = dsolve(eqs, [x1(t), x2(t)], ics = {x1(0):0, x1(t).diff().subs(t,0):0, \ + x2(0):1, x2(t).diff().subs(t,0):0}) + assert x1sol == Eq(x1(t), sqrt(3 - sqrt(5))*(sqrt(10) + 5*sqrt(2))*cos(sqrt(2)*t*sqrt(3 - sqrt(5))/2)/20 + \ + (-5*sqrt(2) + sqrt(10))*sqrt(sqrt(5) + 3)*cos(sqrt(2)*t*sqrt(sqrt(5) + 3)/2)/20) + assert x2sol == Eq(x2(t), (sqrt(5) + 5)*cos(sqrt(2)*t*sqrt(3 - sqrt(5))/2)/10 + (5 - sqrt(5))*cos(sqrt(2)*t*sqrt(sqrt(5) + 3)/2)/10) + + +def test_issue_22462(): + for de in [ + Eq(f(x).diff(x), -20*f(x)**2 - 500*f(x)/7200), + Eq(f(x).diff(x), -2*f(x)**2 - 5*f(x)/7)]: + assert 'Bernoulli' in classify_ode(de, f(x)) + + +def test_issue_23425(): + x = symbols('x') + y = Function('y') + eq = Eq(-E**x*y(x).diff().diff() + y(x).diff(), 0) + assert classify_ode(eq) == \ + ('Liouville', 'nth_order_reducible', \ + '2nd_power_series_ordinary', 'Liouville_Integral') + + +@SKIP("too slow for @slow") +def test_issue_25820(): + x = Symbol('x') + y = Function('y') + eq = y(x)**3*y(x).diff(x, 2) + 49 + assert dsolve(eq, y(x)) is not None # doesn't raise diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_riccati.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_riccati.py new file mode 100644 index 0000000000000000000000000000000000000000..548a1ee5b5e82d88f1b0aa319af09b8b9d1d9bfe --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_riccati.py @@ -0,0 +1,877 @@ +from sympy.core.random import randint +from sympy.core.function import Function +from sympy.core.mul import Mul +from sympy.core.numbers import (I, Rational, oo) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, symbols) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.hyperbolic import tanh +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import sin +from sympy.polys.polytools import Poly +from sympy.simplify.ratsimp import ratsimp +from sympy.solvers.ode.subscheck import checkodesol +from sympy.testing.pytest import slow +from sympy.solvers.ode.riccati import (riccati_normal, riccati_inverse_normal, + riccati_reduced, match_riccati, inverse_transform_poly, limit_at_inf, + check_necessary_conds, val_at_inf, construct_c_case_1, + construct_c_case_2, construct_c_case_3, construct_d_case_4, + construct_d_case_5, construct_d_case_6, rational_laurent_series, + solve_riccati) + +f = Function('f') +x = symbols('x') + +# These are the functions used to generate the tests +# SHOULD NOT BE USED DIRECTLY IN TESTS + +def rand_rational(maxint): + return Rational(randint(-maxint, maxint), randint(1, maxint)) + + +def rand_poly(x, degree, maxint): + return Poly([rand_rational(maxint) for _ in range(degree+1)], x) + + +def rand_rational_function(x, degree, maxint): + degnum = randint(1, degree) + degden = randint(1, degree) + num = rand_poly(x, degnum, maxint) + den = rand_poly(x, degden, maxint) + while den == Poly(0, x): + den = rand_poly(x, degden, maxint) + return num / den + + +def find_riccati_ode(ratfunc, x, yf): + y = ratfunc + yp = y.diff(x) + q1 = rand_rational_function(x, 1, 3) + q2 = rand_rational_function(x, 1, 3) + while q2 == 0: + q2 = rand_rational_function(x, 1, 3) + q0 = ratsimp(yp - q1*y - q2*y**2) + eq = Eq(yf.diff(), q0 + q1*yf + q2*yf**2) + sol = Eq(yf, y) + assert checkodesol(eq, sol) == (True, 0) + return eq, q0, q1, q2 + + +# Testing functions start + +def test_riccati_transformation(): + """ + This function tests the transformation of the + solution of a Riccati ODE to the solution of + its corresponding normal Riccati ODE. + + Each test case 4 values - + + 1. w - The solution to be transformed + 2. b1 - The coefficient of f(x) in the ODE. + 3. b2 - The coefficient of f(x)**2 in the ODE. + 4. y - The solution to the normal Riccati ODE. + """ + tests = [ + ( + x/(x - 1), + (x**2 + 7)/3*x, + x, + -x**2/(x - 1) - x*(x**2/3 + S(7)/3)/2 - 1/(2*x) + ), + ( + (2*x + 3)/(2*x + 2), + (3 - 3*x)/(x + 1), + 5*x, + -5*x*(2*x + 3)/(2*x + 2) - (3 - 3*x)/(Mul(2, x + 1, evaluate=False)) - 1/(2*x) + ), + ( + -1/(2*x**2 - 1), + 0, + (2 - x)/(4*x - 2), + (2 - x)/((4*x - 2)*(2*x**2 - 1)) - (4*x - 2)*(Mul(-4, 2 - x, evaluate=False)/(4*x - \ + 2)**2 - 1/(4*x - 2))/(Mul(2, 2 - x, evaluate=False)) + ), + ( + x, + (8*x - 12)/(12*x + 9), + x**3/(6*x - 9), + -x**4/(6*x - 9) - (8*x - 12)/(Mul(2, 12*x + 9, evaluate=False)) - (6*x - 9)*(-6*x**3/(6*x \ + - 9)**2 + 3*x**2/(6*x - 9))/(2*x**3) + )] + for w, b1, b2, y in tests: + assert y == riccati_normal(w, x, b1, b2) + assert w == riccati_inverse_normal(y, x, b1, b2).cancel() + + # Test bp parameter in riccati_inverse_normal + tests = [ + ( + (-2*x - 1)/(2*x**2 + 2*x - 2), + -2/x, + (-x - 1)/(4*x), + 8*x**2*(1/(4*x) + (-x - 1)/(4*x**2))/(-x - 1)**2 + 4/(-x - 1), + -2*x*(-1/(4*x) - (-x - 1)/(4*x**2))/(-x - 1) - (-2*x - 1)*(-x - 1)/(4*x*(2*x**2 + 2*x \ + - 2)) + 1/x + ), + ( + 3/(2*x**2), + -2/x, + (-x - 1)/(4*x), + 8*x**2*(1/(4*x) + (-x - 1)/(4*x**2))/(-x - 1)**2 + 4/(-x - 1), + -2*x*(-1/(4*x) - (-x - 1)/(4*x**2))/(-x - 1) + 1/x - Mul(3, -x - 1, evaluate=False)/(8*x**3) + )] + for w, b1, b2, bp, y in tests: + assert y == riccati_normal(w, x, b1, b2) + assert w == riccati_inverse_normal(y, x, b1, b2, bp).cancel() + + +def test_riccati_reduced(): + """ + This function tests the transformation of a + Riccati ODE to its normal Riccati ODE. + + Each test case 2 values - + + 1. eq - A Riccati ODE. + 2. normal_eq - The normal Riccati ODE of eq. + """ + tests = [ + ( + f(x).diff(x) - x**2 - x*f(x) - x*f(x)**2, + + f(x).diff(x) + f(x)**2 + x**3 - x**2/4 - 3/(4*x**2) + ), + ( + 6*x/(2*x + 9) + f(x).diff(x) - (x + 1)*f(x)**2/x, + + -3*x**2*(1/x + (-x - 1)/x**2)**2/(4*(-x - 1)**2) + Mul(6, \ + -x - 1, evaluate=False)/(2*x + 9) + f(x)**2 + f(x).diff(x) \ + - (-1 + (x + 1)/x)/(x*(-x - 1)) + ), + ( + f(x)**2 + f(x).diff(x) - (x - 1)*f(x)/(-x - S(1)/2), + + -(2*x - 2)**2/(4*(2*x + 1)**2) + (2*x - 2)/(2*x + 1)**2 + \ + f(x)**2 + f(x).diff(x) - 1/(2*x + 1) + ), + ( + f(x).diff(x) - f(x)**2/x, + + f(x)**2 + f(x).diff(x) + 1/(4*x**2) + ), + ( + -3*(-x**2 - x + 1)/(x**2 + 6*x + 1) + f(x).diff(x) + f(x)**2/x, + + f(x)**2 + f(x).diff(x) + (3*x**2/(x**2 + 6*x + 1) + 3*x/(x**2 \ + + 6*x + 1) - 3/(x**2 + 6*x + 1))/x + 1/(4*x**2) + ), + ( + 6*x/(2*x + 9) + f(x).diff(x) - (x + 1)*f(x)/x, + + False + ), + ( + f(x)*f(x).diff(x) - 1/x + f(x)/3 + f(x)**2/(x**2 - 2), + + False + )] + for eq, normal_eq in tests: + assert normal_eq == riccati_reduced(eq, f, x) + + +def test_match_riccati(): + """ + This function tests if an ODE is Riccati or not. + + Each test case has 5 values - + + 1. eq - The Riccati ODE. + 2. match - Boolean indicating if eq is a Riccati ODE. + 3. b0 - + 4. b1 - Coefficient of f(x) in eq. + 5. b2 - Coefficient of f(x)**2 in eq. + """ + tests = [ + # Test Rational Riccati ODEs + ( + f(x).diff(x) - (405*x**3 - 882*x**2 - 78*x + 92)/(243*x**4 \ + - 945*x**3 + 846*x**2 + 180*x - 72) - 2 - f(x)**2/(3*x + 1) \ + - (S(1)/3 - x)*f(x)/(S(1)/3 - 3*x/2), + + True, + + 45*x**3/(27*x**4 - 105*x**3 + 94*x**2 + 20*x - 8) - 98*x**2/ \ + (27*x**4 - 105*x**3 + 94*x**2 + 20*x - 8) - 26*x/(81*x**4 - \ + 315*x**3 + 282*x**2 + 60*x - 24) + 2 + 92/(243*x**4 - 945*x**3 \ + + 846*x**2 + 180*x - 72), + + Mul(-1, 2 - 6*x, evaluate=False)/(9*x - 2), + + 1/(3*x + 1) + ), + ( + f(x).diff(x) + 4*x/27 - (x/3 - 1)*f(x)**2 - (2*x/3 + \ + 1)*f(x)/(3*x + 2) - S(10)/27 - (265*x**2 + 423*x + 162) \ + /(324*x**3 + 216*x**2), + + True, + + -4*x/27 + S(10)/27 + 3/(6*x**3 + 4*x**2) + 47/(36*x**2 \ + + 24*x) + 265/(324*x + 216), + + Mul(-1, -2*x - 3, evaluate=False)/(9*x + 6), + + x/3 - 1 + ), + ( + f(x).diff(x) - (304*x**5 - 745*x**4 + 631*x**3 - 876*x**2 \ + + 198*x - 108)/(36*x**6 - 216*x**5 + 477*x**4 - 567*x**3 + \ + 360*x**2 - 108*x) - S(17)/9 - (x - S(3)/2)*f(x)/(x/2 - \ + S(3)/2) - (x/3 - 3)*f(x)**2/(3*x), + + True, + + 304*x**4/(36*x**5 - 216*x**4 + 477*x**3 - 567*x**2 + 360*x - \ + 108) - 745*x**3/(36*x**5 - 216*x**4 + 477*x**3 - 567*x**2 + \ + 360*x - 108) + 631*x**2/(36*x**5 - 216*x**4 + 477*x**3 - 567* \ + x**2 + 360*x - 108) - 292*x/(12*x**5 - 72*x**4 + 159*x**3 - \ + 189*x**2 + 120*x - 36) + S(17)/9 - 12/(4*x**6 - 24*x**5 + \ + 53*x**4 - 63*x**3 + 40*x**2 - 12*x) + 22/(4*x**5 - 24*x**4 \ + + 53*x**3 - 63*x**2 + 40*x - 12), + + Mul(-1, 3 - 2*x, evaluate=False)/(x - 3), + + Mul(-1, 9 - x, evaluate=False)/(9*x) + ), + # Test Non-Rational Riccati ODEs + ( + f(x).diff(x) - x**(S(3)/2)/(x**(S(1)/2) - 2) + x**2*f(x) + \ + x*f(x)**2/(x**(S(3)/4)), + False, 0, 0, 0 + ), + ( + f(x).diff(x) - sin(x**2) + exp(x)*f(x) + log(x)*f(x)**2, + False, 0, 0, 0 + ), + ( + f(x).diff(x) - tanh(x + sqrt(x)) + f(x) + x**4*f(x)**2, + False, 0, 0, 0 + ), + # Test Non-Riccati ODEs + ( + (1 - x**2)*f(x).diff(x, 2) - 2*x*f(x).diff(x) + 20*f(x), + False, 0, 0, 0 + ), + ( + f(x).diff(x) - x**2 + x**3*f(x) + (x**2/(x + 1))*f(x)**3, + False, 0, 0, 0 + ), + ( + f(x).diff(x)*f(x)**2 + (x**2 - 1)/(x**3 + 1)*f(x) + 1/(2*x \ + + 3) + f(x)**2, + False, 0, 0, 0 + )] + for eq, res, b0, b1, b2 in tests: + match, funcs = match_riccati(eq, f, x) + assert match == res + if res: + assert [b0, b1, b2] == funcs + + +def test_val_at_inf(): + """ + This function tests the valuation of rational + function at oo. + + Each test case has 3 values - + + 1. num - Numerator of rational function. + 2. den - Denominator of rational function. + 3. val_inf - Valuation of rational function at oo + """ + tests = [ + # degree(denom) > degree(numer) + ( + Poly(10*x**3 + 8*x**2 - 13*x + 6, x), + Poly(-13*x**10 - x**9 + 5*x**8 + 7*x**7 + 10*x**6 + 6*x**5 - 7*x**4 + 11*x**3 - 8*x**2 + 5*x + 13, x), + 7 + ), + ( + Poly(1, x), + Poly(-9*x**4 + 3*x**3 + 15*x**2 - 6*x - 14, x), + 4 + ), + # degree(denom) == degree(numer) + ( + Poly(-6*x**3 - 8*x**2 + 8*x - 6, x), + Poly(-5*x**3 + 12*x**2 - 6*x - 9, x), + 0 + ), + # degree(denom) < degree(numer) + ( + Poly(12*x**8 - 12*x**7 - 11*x**6 + 8*x**5 + 3*x**4 - x**3 + x**2 - 11*x, x), + Poly(-14*x**2 + x, x), + -6 + ), + ( + Poly(5*x**6 + 9*x**5 - 11*x**4 - 9*x**3 + x**2 - 4*x + 4, x), + Poly(15*x**4 + 3*x**3 - 8*x**2 + 15*x + 12, x), + -2 + )] + for num, den, val in tests: + assert val_at_inf(num, den, x) == val + + +def test_necessary_conds(): + """ + This function tests the necessary conditions for + a Riccati ODE to have a rational particular solution. + """ + # Valuation at Infinity is an odd negative integer + assert check_necessary_conds(-3, [1, 2, 4]) == False + # Valuation at Infinity is a positive integer lesser than 2 + assert check_necessary_conds(1, [1, 2, 4]) == False + # Multiplicity of a pole is an odd integer greater than 1 + assert check_necessary_conds(2, [3, 1, 6]) == False + # All values are correct + assert check_necessary_conds(-10, [1, 2, 8, 12]) == True + + +def test_inverse_transform_poly(): + """ + This function tests the substitution x -> 1/x + in rational functions represented using Poly. + """ + fns = [ + (15*x**3 - 8*x**2 - 2*x - 6)/(18*x + 6), + + (180*x**5 + 40*x**4 + 80*x**3 + 30*x**2 - 60*x - 80)/(180*x**3 - 150*x**2 + 75*x + 12), + + (-15*x**5 - 36*x**4 + 75*x**3 - 60*x**2 - 80*x - 60)/(80*x**4 + 60*x**3 + 60*x**2 + 60*x - 80), + + (60*x**7 + 24*x**6 - 15*x**5 - 20*x**4 + 30*x**2 + 100*x - 60)/(240*x**2 - 20*x - 30), + + (30*x**6 - 12*x**5 + 15*x**4 - 15*x**2 + 10*x + 60)/(3*x**10 - 45*x**9 + 15*x**5 + 15*x**4 - 5*x**3 \ + + 15*x**2 + 45*x - 15) + ] + for f in fns: + num, den = [Poly(e, x) for e in f.as_numer_denom()] + num, den = inverse_transform_poly(num, den, x) + assert f.subs(x, 1/x).cancel() == num/den + + +def test_limit_at_inf(): + """ + This function tests the limit at oo of a + rational function. + + Each test case has 3 values - + + 1. num - Numerator of rational function. + 2. den - Denominator of rational function. + 3. limit_at_inf - Limit of rational function at oo + """ + tests = [ + # deg(denom) > deg(numer) + ( + Poly(-12*x**2 + 20*x + 32, x), + Poly(32*x**3 + 72*x**2 + 3*x - 32, x), + 0 + ), + # deg(denom) < deg(numer) + ( + Poly(1260*x**4 - 1260*x**3 - 700*x**2 - 1260*x + 1400, x), + Poly(6300*x**3 - 1575*x**2 + 756*x - 540, x), + oo + ), + # deg(denom) < deg(numer), one of the leading coefficients is negative + ( + Poly(-735*x**8 - 1400*x**7 + 1680*x**6 - 315*x**5 - 600*x**4 + 840*x**3 - 525*x**2 \ + + 630*x + 3780, x), + Poly(1008*x**7 - 2940*x**6 - 84*x**5 + 2940*x**4 - 420*x**3 + 1512*x**2 + 105*x + 168, x), + -oo + ), + # deg(denom) == deg(numer) + ( + Poly(105*x**7 - 960*x**6 + 60*x**5 + 60*x**4 - 80*x**3 + 45*x**2 + 120*x + 15, x), + Poly(735*x**7 + 525*x**6 + 720*x**5 + 720*x**4 - 8400*x**3 - 2520*x**2 + 2800*x + 280, x), + S(1)/7 + ), + ( + Poly(288*x**4 - 450*x**3 + 280*x**2 - 900*x - 90, x), + Poly(607*x**4 + 840*x**3 - 1050*x**2 + 420*x + 420, x), + S(288)/607 + )] + for num, den, lim in tests: + assert limit_at_inf(num, den, x) == lim + + +def test_construct_c_case_1(): + """ + This function tests the Case 1 in the step + to calculate coefficients of c-vectors. + + Each test case has 4 values - + + 1. num - Numerator of the rational function a(x). + 2. den - Denominator of the rational function a(x). + 3. pole - Pole of a(x) for which c-vector is being + calculated. + 4. c - The c-vector for the pole. + """ + tests = [ + ( + Poly(-3*x**3 + 3*x**2 + 4*x - 5, x, extension=True), + Poly(4*x**8 + 16*x**7 + 9*x**5 + 12*x**4 + 6*x**3 + 12*x**2, x, extension=True), + S(0), + [[S(1)/2 + sqrt(6)*I/6], [S(1)/2 - sqrt(6)*I/6]] + ), + ( + Poly(1200*x**3 + 1440*x**2 + 816*x + 560, x, extension=True), + Poly(128*x**5 - 656*x**4 + 1264*x**3 - 1125*x**2 + 385*x + 49, x, extension=True), + S(7)/4, + [[S(1)/2 + sqrt(16367978)/634], [S(1)/2 - sqrt(16367978)/634]] + ), + ( + Poly(4*x + 2, x, extension=True), + Poly(18*x**4 + (2 - 18*sqrt(3))*x**3 + (14 - 11*sqrt(3))*x**2 + (4 - 6*sqrt(3))*x \ + + 8*sqrt(3) + 16, x, domain='QQ'), + (S(1) + sqrt(3))/2, + [[S(1)/2 + sqrt(Mul(4, 2*sqrt(3) + 4, evaluate=False)/(19*sqrt(3) + 44) + 1)/2], \ + [S(1)/2 - sqrt(Mul(4, 2*sqrt(3) + 4, evaluate=False)/(19*sqrt(3) + 44) + 1)/2]] + )] + for num, den, pole, c in tests: + assert construct_c_case_1(num, den, x, pole) == c + + +def test_construct_c_case_2(): + """ + This function tests the Case 2 in the step + to calculate coefficients of c-vectors. + + Each test case has 5 values - + + 1. num - Numerator of the rational function a(x). + 2. den - Denominator of the rational function a(x). + 3. pole - Pole of a(x) for which c-vector is being + calculated. + 4. mul - The multiplicity of the pole. + 5. c - The c-vector for the pole. + """ + tests = [ + # Testing poles with multiplicity 2 + ( + Poly(1, x, extension=True), + Poly((x - 1)**2*(x - 2), x, extension=True), + 1, 2, + [[-I*(-1 - I)/2], [I*(-1 + I)/2]] + ), + ( + Poly(3*x**5 - 12*x**4 - 7*x**3 + 1, x, extension=True), + Poly((3*x - 1)**2*(x + 2)**2, x, extension=True), + S(1)/3, 2, + [[-S(89)/98], [-S(9)/98]] + ), + # Testing poles with multiplicity 4 + ( + Poly(x**3 - x**2 + 4*x, x, extension=True), + Poly((x - 2)**4*(x + 5)**2, x, extension=True), + 2, 4, + [[7*sqrt(3)*(S(60)/343 - 4*sqrt(3)/7)/12, 2*sqrt(3)/7], \ + [-7*sqrt(3)*(S(60)/343 + 4*sqrt(3)/7)/12, -2*sqrt(3)/7]] + ), + ( + Poly(3*x**5 + x**4 + 3, x, extension=True), + Poly((4*x + 1)**4*(x + 2), x, extension=True), + -S(1)/4, 4, + [[128*sqrt(439)*(-sqrt(439)/128 - S(55)/14336)/439, sqrt(439)/256], \ + [-128*sqrt(439)*(sqrt(439)/128 - S(55)/14336)/439, -sqrt(439)/256]] + ), + # Testing poles with multiplicity 6 + ( + Poly(x**3 + 2, x, extension=True), + Poly((3*x - 1)**6*(x**2 + 1), x, extension=True), + S(1)/3, 6, + [[27*sqrt(66)*(-sqrt(66)/54 - S(131)/267300)/22, -2*sqrt(66)/1485, sqrt(66)/162], \ + [-27*sqrt(66)*(sqrt(66)/54 - S(131)/267300)/22, 2*sqrt(66)/1485, -sqrt(66)/162]] + ), + ( + Poly(x**2 + 12, x, extension=True), + Poly((x - sqrt(2))**6, x, extension=True), + sqrt(2), 6, + [[sqrt(14)*(S(6)/7 - 3*sqrt(14))/28, sqrt(7)/7, sqrt(14)], \ + [-sqrt(14)*(S(6)/7 + 3*sqrt(14))/28, -sqrt(7)/7, -sqrt(14)]] + )] + for num, den, pole, mul, c in tests: + assert construct_c_case_2(num, den, x, pole, mul) == c + + +def test_construct_c_case_3(): + """ + This function tests the Case 3 in the step + to calculate coefficients of c-vectors. + """ + assert construct_c_case_3() == [[1]] + + +def test_construct_d_case_4(): + """ + This function tests the Case 4 in the step + to calculate coefficients of the d-vector. + + Each test case has 4 values - + + 1. num - Numerator of the rational function a(x). + 2. den - Denominator of the rational function a(x). + 3. mul - Multiplicity of oo as a pole. + 4. d - The d-vector. + """ + tests = [ + # Tests with multiplicity at oo = 2 + ( + Poly(-x**5 - 2*x**4 + 4*x**3 + 2*x + 5, x, extension=True), + Poly(9*x**3 - 2*x**2 + 10*x - 2, x, extension=True), + 2, + [[10*I/27, I/3, -3*I*(S(158)/243 - I/3)/2], \ + [-10*I/27, -I/3, 3*I*(S(158)/243 + I/3)/2]] + ), + ( + Poly(-x**6 + 9*x**5 + 5*x**4 + 6*x**3 + 5*x**2 + 6*x + 7, x, extension=True), + Poly(x**4 + 3*x**3 + 12*x**2 - x + 7, x, extension=True), + 2, + [[-6*I, I, -I*(17 - I)/2], [6*I, -I, I*(17 + I)/2]] + ), + # Tests with multiplicity at oo = 4 + ( + Poly(-2*x**6 - x**5 - x**4 - 2*x**3 - x**2 - 3*x - 3, x, extension=True), + Poly(3*x**2 + 10*x + 7, x, extension=True), + 4, + [[269*sqrt(6)*I/288, -17*sqrt(6)*I/36, sqrt(6)*I/3, -sqrt(6)*I*(S(16969)/2592 \ + - 2*sqrt(6)*I/3)/4], [-269*sqrt(6)*I/288, 17*sqrt(6)*I/36, -sqrt(6)*I/3, \ + sqrt(6)*I*(S(16969)/2592 + 2*sqrt(6)*I/3)/4]] + ), + ( + Poly(-3*x**5 - 3*x**4 - 3*x**3 - x**2 - 1, x, extension=True), + Poly(12*x - 2, x, extension=True), + 4, + [[41*I/192, 7*I/24, I/2, -I*(-S(59)/6912 - I)], \ + [-41*I/192, -7*I/24, -I/2, I*(-S(59)/6912 + I)]] + ), + # Tests with multiplicity at oo = 4 + ( + Poly(-x**7 - x**5 - x**4 - x**2 - x, x, extension=True), + Poly(x + 2, x, extension=True), + 6, + [[-5*I/2, 2*I, -I, I, -I*(-9 - 3*I)/2], [5*I/2, -2*I, I, -I, I*(-9 + 3*I)/2]] + ), + ( + Poly(-x**7 - x**6 - 2*x**5 - 2*x**4 - x**3 - x**2 + 2*x - 2, x, extension=True), + Poly(2*x - 2, x, extension=True), + 6, + [[3*sqrt(2)*I/4, 3*sqrt(2)*I/4, sqrt(2)*I/2, sqrt(2)*I/2, -sqrt(2)*I*(-S(7)/8 - \ + 3*sqrt(2)*I/2)/2], [-3*sqrt(2)*I/4, -3*sqrt(2)*I/4, -sqrt(2)*I/2, -sqrt(2)*I/2, \ + sqrt(2)*I*(-S(7)/8 + 3*sqrt(2)*I/2)/2]] + )] + for num, den, mul, d in tests: + ser = rational_laurent_series(num, den, x, oo, mul, 1) + assert construct_d_case_4(ser, mul//2) == d + + +def test_construct_d_case_5(): + """ + This function tests the Case 5 in the step + to calculate coefficients of the d-vector. + + Each test case has 3 values - + + 1. num - Numerator of the rational function a(x). + 2. den - Denominator of the rational function a(x). + 3. d - The d-vector. + """ + tests = [ + ( + Poly(2*x**3 + x**2 + x - 2, x, extension=True), + Poly(9*x**3 + 5*x**2 + 2*x - 1, x, extension=True), + [[sqrt(2)/3, -sqrt(2)/108], [-sqrt(2)/3, sqrt(2)/108]] + ), + ( + Poly(3*x**5 + x**4 - x**3 + x**2 - 2*x - 2, x, domain='ZZ'), + Poly(9*x**5 + 7*x**4 + 3*x**3 + 2*x**2 + 5*x + 7, x, domain='ZZ'), + [[sqrt(3)/3, -2*sqrt(3)/27], [-sqrt(3)/3, 2*sqrt(3)/27]] + ), + ( + Poly(x**2 - x + 1, x, domain='ZZ'), + Poly(3*x**2 + 7*x + 3, x, domain='ZZ'), + [[sqrt(3)/3, -5*sqrt(3)/9], [-sqrt(3)/3, 5*sqrt(3)/9]] + )] + for num, den, d in tests: + # Multiplicity of oo is 0 + ser = rational_laurent_series(num, den, x, oo, 0, 1) + assert construct_d_case_5(ser) == d + + +def test_construct_d_case_6(): + """ + This function tests the Case 6 in the step + to calculate coefficients of the d-vector. + + Each test case has 3 values - + + 1. num - Numerator of the rational function a(x). + 2. den - Denominator of the rational function a(x). + 3. d - The d-vector. + """ + tests = [ + ( + Poly(-2*x**2 - 5, x, domain='ZZ'), + Poly(4*x**4 + 2*x**2 + 10*x + 2, x, domain='ZZ'), + [[S(1)/2 + I/2], [S(1)/2 - I/2]] + ), + ( + Poly(-2*x**3 - 4*x**2 - 2*x - 5, x, domain='ZZ'), + Poly(x**6 - x**5 + 2*x**4 - 4*x**3 - 5*x**2 - 5*x + 9, x, domain='ZZ'), + [[1], [0]] + ), + ( + Poly(-5*x**3 + x**2 + 11*x + 12, x, domain='ZZ'), + Poly(6*x**8 - 26*x**7 - 27*x**6 - 10*x**5 - 44*x**4 - 46*x**3 - 34*x**2 \ + - 27*x - 42, x, domain='ZZ'), + [[1], [0]] + )] + for num, den, d in tests: + assert construct_d_case_6(num, den, x) == d + + +def test_rational_laurent_series(): + """ + This function tests the computation of coefficients + of Laurent series of a rational function. + + Each test case has 5 values - + + 1. num - Numerator of the rational function. + 2. den - Denominator of the rational function. + 3. x0 - Point about which Laurent series is to + be calculated. + 4. mul - Multiplicity of x0 if x0 is a pole of + the rational function (0 otherwise). + 5. n - Number of terms upto which the series + is to be calculated. + """ + tests = [ + # Laurent series about simple pole (Multiplicity = 1) + ( + Poly(x**2 - 3*x + 9, x, extension=True), + Poly(x**2 - x, x, extension=True), + S(1), 1, 6, + {1: 7, 0: -8, -1: 9, -2: -9, -3: 9, -4: -9} + ), + # Laurent series about multiple pole (Multiplicity > 1) + ( + Poly(64*x**3 - 1728*x + 1216, x, extension=True), + Poly(64*x**4 - 80*x**3 - 831*x**2 + 1809*x - 972, x, extension=True), + S(9)/8, 2, 3, + {0: S(32177152)/46521675, 2: S(1019)/984, -1: S(11947565056)/28610830125, \ + 1: S(209149)/75645} + ), + ( + Poly(1, x, extension=True), + Poly(x**5 + (-4*sqrt(2) - 1)*x**4 + (4*sqrt(2) + 12)*x**3 + (-12 - 8*sqrt(2))*x**2 \ + + (4 + 8*sqrt(2))*x - 4, x, extension=True), + sqrt(2), 4, 6, + {4: 1 + sqrt(2), 3: -3 - 2*sqrt(2), 2: Mul(-1, -3 - 2*sqrt(2), evaluate=False)/(-1 \ + + sqrt(2)), 1: (-3 - 2*sqrt(2))/(-1 + sqrt(2))**2, 0: Mul(-1, -3 - 2*sqrt(2), evaluate=False \ + )/(-1 + sqrt(2))**3, -1: (-3 - 2*sqrt(2))/(-1 + sqrt(2))**4} + ), + # Laurent series about oo + ( + Poly(x**5 - 4*x**3 + 6*x**2 + 10*x - 13, x, extension=True), + Poly(x**2 - 5, x, extension=True), + oo, 3, 6, + {3: 1, 2: 0, 1: 1, 0: 6, -1: 15, -2: 17} + ), + # Laurent series at x0 where x0 is not a pole of the function + # Using multiplicity as 0 (as x0 will not be a pole) + ( + Poly(3*x**3 + 6*x**2 - 2*x + 5, x, extension=True), + Poly(9*x**4 - x**3 - 3*x**2 + 4*x + 4, x, extension=True), + S(2)/5, 0, 1, + {0: S(3345)/3304, -1: S(399325)/2729104, -2: S(3926413375)/4508479808, \ + -3: S(-5000852751875)/1862002160704, -4: S(-6683640101653125)/6152055138966016} + ), + ( + Poly(-7*x**2 + 2*x - 4, x, extension=True), + Poly(7*x**5 + 9*x**4 + 8*x**3 + 3*x**2 + 6*x + 9, x, extension=True), + oo, 0, 6, + {0: 0, -2: 0, -5: -S(71)/49, -1: 0, -3: -1, -4: S(11)/7} + )] + for num, den, x0, mul, n, ser in tests: + assert ser == rational_laurent_series(num, den, x, x0, mul, n) + + +def check_dummy_sol(eq, solse, dummy_sym): + """ + Helper function to check if actual solution + matches expected solution if actual solution + contains dummy symbols. + """ + if isinstance(eq, Eq): + eq = eq.lhs - eq.rhs + _, funcs = match_riccati(eq, f, x) + + sols = solve_riccati(f(x), x, *funcs) + C1 = Dummy('C1') + sols = [sol.subs(C1, dummy_sym) for sol in sols] + + assert all(x[0] for x in checkodesol(eq, sols)) + assert all(s1.dummy_eq(s2, dummy_sym) for s1, s2 in zip(sols, solse)) + + +def test_solve_riccati(): + """ + This function tests the computation of rational + particular solutions for a Riccati ODE. + + Each test case has 2 values - + + 1. eq - Riccati ODE to be solved. + 2. sol - Expected solution to the equation. + + Some examples have been taken from the paper - "Statistical Investigation of + First-Order Algebraic ODEs and their Rational General Solutions" by + Georg Grasegger, N. Thieu Vo, Franz Winkler + + https://www3.risc.jku.at/publications/download/risc_5197/RISCReport15-19.pdf + """ + C0 = Dummy('C0') + # Type: 1st Order Rational Riccati, dy/dx = a + b*y + c*y**2, + # a, b, c are rational functions of x + + tests = [ + # a(x) is a constant + ( + Eq(f(x).diff(x) + f(x)**2 - 2, 0), + [Eq(f(x), sqrt(2)), Eq(f(x), -sqrt(2))] + ), + # a(x) is a constant + ( + f(x)**2 + f(x).diff(x) + 4*f(x)/x + 2/x**2, + [Eq(f(x), (-2*C0 - x)/(C0*x + x**2))] + ), + # a(x) is a constant + ( + 2*x**2*f(x).diff(x) - x*(4*f(x) + f(x).diff(x) - 4) + (f(x) - 1)*f(x), + [Eq(f(x), (C0 + 2*x**2)/(C0 + x))] + ), + # Pole with multiplicity 1 + ( + Eq(f(x).diff(x), -f(x)**2 - 2/(x**3 - x**2)), + [Eq(f(x), 1/(x**2 - x))] + ), + # One pole of multiplicity 2 + ( + x**2 - (2*x + 1/x)*f(x) + f(x)**2 + f(x).diff(x), + [Eq(f(x), (C0*x + x**3 + 2*x)/(C0 + x**2)), Eq(f(x), x)] + ), + ( + x**4*f(x).diff(x) + x**2 - x*(2*f(x)**2 + f(x).diff(x)) + f(x), + [Eq(f(x), (C0*x**2 + x)/(C0 + x**2)), Eq(f(x), x**2)] + ), + # Multiple poles of multiplicity 2 + ( + -f(x)**2 + f(x).diff(x) + (15*x**2 - 20*x + 7)/((x - 1)**2*(2*x \ + - 1)**2), + [Eq(f(x), (9*C0*x - 6*C0 - 15*x**5 + 60*x**4 - 94*x**3 + 72*x**2 \ + - 30*x + 6)/(6*C0*x**2 - 9*C0*x + 3*C0 + 6*x**6 - 29*x**5 + \ + 57*x**4 - 58*x**3 + 30*x**2 - 6*x)), Eq(f(x), (3*x - 2)/(2*x**2 \ + - 3*x + 1))] + ), + # Regression: Poles with even multiplicity > 2 fixed + ( + f(x)**2 + f(x).diff(x) - (4*x**6 - 8*x**5 + 12*x**4 + 4*x**3 + \ + 7*x**2 - 20*x + 4)/(4*x**4), + [Eq(f(x), (2*x**5 - 2*x**4 - x**3 + 4*x**2 + 3*x - 2)/(2*x**4 \ + - 2*x**2))] + ), + # Regression: Poles with even multiplicity > 2 fixed + ( + Eq(f(x).diff(x), (-x**6 + 15*x**4 - 40*x**3 + 45*x**2 - 24*x + 4)/\ + (x**12 - 12*x**11 + 66*x**10 - 220*x**9 + 495*x**8 - 792*x**7 + 924*x**6 - \ + 792*x**5 + 495*x**4 - 220*x**3 + 66*x**2 - 12*x + 1) + f(x)**2 + f(x)), + [Eq(f(x), 1/(x**6 - 6*x**5 + 15*x**4 - 20*x**3 + 15*x**2 - 6*x + 1))] + ), + # More than 2 poles with multiplicity 2 + # Regression: Fixed mistake in necessary conditions + ( + Eq(f(x).diff(x), x*f(x) + 2*x + (3*x - 2)*f(x)**2/(4*x + 2) + \ + (8*x**2 - 7*x + 26)/(16*x**3 - 24*x**2 + 8) - S(3)/2), + [Eq(f(x), (1 - 4*x)/(2*x - 2))] + ), + # Regression: Fixed mistake in necessary conditions + ( + Eq(f(x).diff(x), (-12*x**2 - 48*x - 15)/(24*x**3 - 40*x**2 + 8*x + 8) \ + + 3*f(x)**2/(6*x + 2)), + [Eq(f(x), (2*x + 1)/(2*x - 2))] + ), + # Imaginary poles + ( + f(x).diff(x) + (3*x**2 + 1)*f(x)**2/x + (6*x**2 - x + 3)*f(x)/(x*(x \ + - 1)) + (3*x**2 - 2*x + 2)/(x*(x - 1)**2), + [Eq(f(x), (-C0 - x**3 + x**2 - 2*x)/(C0*x - C0 + x**4 - x**3 + x**2 \ + - x)), Eq(f(x), -1/(x - 1))], + ), + # Imaginary coefficients in equation + ( + f(x).diff(x) - 2*I*(f(x)**2 + 1)/x, + [Eq(f(x), (-I*C0 + I*x**4)/(C0 + x**4)), Eq(f(x), -I)] + ), + # Regression: linsolve returning empty solution + # Large value of m (> 10) + ( + Eq(f(x).diff(x), x*f(x)/(S(3)/2 - 2*x) + (x/2 - S(1)/3)*f(x)**2/\ + (2*x/3 - S(1)/2) - S(5)/4 + (281*x**2 - 1260*x + 756)/(16*x**3 - 12*x**2)), + [Eq(f(x), (9 - x)/x), Eq(f(x), (40*x**14 + 28*x**13 + 420*x**12 + 2940*x**11 + \ + 18480*x**10 + 103950*x**9 + 519750*x**8 + 2286900*x**7 + 8731800*x**6 + 28378350*\ + x**5 + 76403250*x**4 + 163721250*x**3 + 261954000*x**2 + 278326125*x + 147349125)/\ + ((24*x**14 + 140*x**13 + 840*x**12 + 4620*x**11 + 23100*x**10 + 103950*x**9 + \ + 415800*x**8 + 1455300*x**7 + 4365900*x**6 + 10914750*x**5 + 21829500*x**4 + 32744250\ + *x**3 + 32744250*x**2 + 16372125*x)))] + ), + # Regression: Fixed bug due to a typo in paper + ( + Eq(f(x).diff(x), 18*x**3 + 18*x**2 + (-x/2 - S(1)/2)*f(x)**2 + 6), + [Eq(f(x), 6*x)] + ), + # Regression: Fixed bug due to a typo in paper + ( + Eq(f(x).diff(x), -3*x**3/4 + 15*x/2 + (x/3 - S(4)/3)*f(x)**2 \ + + 9 + (1 - x)*f(x)/x + 3/x), + [Eq(f(x), -3*x/2 - 3)] + )] + for eq, sol in tests: + check_dummy_sol(eq, sol, C0) + + +@slow +def test_solve_riccati_slow(): + """ + This function tests the computation of rational + particular solutions for a Riccati ODE. + + Each test case has 2 values - + + 1. eq - Riccati ODE to be solved. + 2. sol - Expected solution to the equation. + """ + C0 = Dummy('C0') + tests = [ + # Very large values of m (989 and 991) + ( + Eq(f(x).diff(x), (1 - x)*f(x)/(x - 3) + (2 - 12*x)*f(x)**2/(2*x - 9) + \ + (54924*x**3 - 405264*x**2 + 1084347*x - 1087533)/(8*x**4 - 132*x**3 + 810*x**2 - \ + 2187*x + 2187) + 495), + [Eq(f(x), (18*x + 6)/(2*x - 9))] + )] + for eq, sol in tests: + check_dummy_sol(eq, sol, C0) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_single.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_single.py new file mode 100644 index 0000000000000000000000000000000000000000..45b38029e97b9e74236c45f2f3efb6aa87c26e5c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_single.py @@ -0,0 +1,2902 @@ +# +# The main tests for the code in single.py are currently located in +# sympy/solvers/tests/test_ode.py +# +r""" +This File contains test functions for the individual hints used for solving ODEs. + +Examples of each solver will be returned by _get_examples_ode_sol_name_of_solver. + +Examples should have a key 'XFAIL' which stores the list of hints if they are +expected to fail for that hint. + +Functions that are for internal use: + +1) _ode_solver_test(ode_examples) - It takes a dictionary of examples returned by + _get_examples method and tests them with their respective hints. + +2) _test_particular_example(our_hint, example_name) - It tests the ODE example corresponding + to the hint provided. + +3) _test_all_hints(runxfail=False) - It is used to test all the examples with all the hints + currently implemented. It calls _test_all_examples_for_one_hint() which outputs whether the + given hint functions properly if it classifies the ODE example. + If runxfail flag is set to True then it will only test the examples which are expected to fail. + + Everytime the ODE of a particular solver is added, _test_all_hints() is to be executed to find + the possible failures of different solver hints. + +4) _test_all_examples_for_one_hint(our_hint, all_examples) - It takes hint as argument and checks + this hint against all the ODE examples and gives output as the number of ODEs matched, number + of ODEs which were solved correctly, list of ODEs which gives incorrect solution and list of + ODEs which raises exception. + +""" +from sympy.core.function import (Derivative, diff) +from sympy.core.mul import Mul +from sympy.core.numbers import (E, I, Rational, pi) +from sympy.core.relational import (Eq, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, symbols) +from sympy.functions.elementary.complexes import (im, re) +from sympy.functions.elementary.exponential import (LambertW, exp, log) +from sympy.functions.elementary.hyperbolic import (asinh, cosh, sinh, tanh) +from sympy.functions.elementary.miscellaneous import (cbrt, sqrt) +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (acos, asin, atan, cos, sec, sin, tan) +from sympy.functions.special.error_functions import (Ei, erfi) +from sympy.functions.special.hyper import hyper +from sympy.integrals.integrals import (Integral, integrate) +from sympy.polys.rootoftools import rootof + +from sympy.core import Function, Symbol +from sympy.functions import airyai, airybi, besselj, bessely, lowergamma +from sympy.integrals.risch import NonElementaryIntegral +from sympy.solvers.ode import classify_ode, dsolve +from sympy.solvers.ode.ode import allhints, _remove_redundant_solutions +from sympy.solvers.ode.single import (FirstLinear, ODEMatchError, + SingleODEProblem, SingleODESolver, NthOrderReducible) + +from sympy.solvers.ode.subscheck import checkodesol + +from sympy.testing.pytest import raises, slow +import traceback + + +x = Symbol('x') +u = Symbol('u') +_u = Dummy('u') +y = Symbol('y') +f = Function('f') +g = Function('g') +C1, C2, C3, C4, C5, C6, C7, C8, C9, C10 = symbols('C1:11') +a, b, c = symbols('a b c') + + +hint_message = """\ +Hint did not match the example {example}. + +The ODE is: +{eq}. + +The expected hint was +{our_hint}\ +""" + +expected_sol_message = """\ +Different solution found from dsolve for example {example}. + +The ODE is: +{eq} + +The expected solution was +{sol} + +What dsolve returned is: +{dsolve_sol}\ +""" + +checkodesol_msg = """\ +solution found is not correct for example {example}. + +The ODE is: +{eq}\ +""" + +dsol_incorrect_msg = """\ +solution returned by dsolve is incorrect when using {hint}. + +The ODE is: +{eq} + +The expected solution was +{sol} + +what dsolve returned is: +{dsolve_sol} + +You can test this with: + +eq = {eq} +sol = dsolve(eq, hint='{hint}') +print(sol) +print(checkodesol(eq, sol)) + +""" + +exception_msg = """\ +dsolve raised exception : {e} + +when using {hint} for the example {example} + +You can test this with: + +from sympy.solvers.ode.tests.test_single import _test_an_example + +_test_an_example('{hint}', example_name = '{example}') + +The ODE is: +{eq} + +\ +""" + +check_hint_msg = """\ +Tested hint was : {hint} + +Total of {matched} examples matched with this hint. + +Out of which {solve} gave correct results. + +Examples which gave incorrect results are {unsolve}. + +Examples which raised exceptions are {exceptions} +\ +""" + + +def _add_example_keys(func): + def inner(): + solver=func() + examples=[] + for example in solver['examples']: + temp={ + 'eq': solver['examples'][example]['eq'], + 'sol': solver['examples'][example]['sol'], + 'XFAIL': solver['examples'][example].get('XFAIL', []), + 'func': solver['examples'][example].get('func',solver['func']), + 'example_name': example, + 'slow': solver['examples'][example].get('slow', False), + 'simplify_flag':solver['examples'][example].get('simplify_flag',True), + 'checkodesol_XFAIL': solver['examples'][example].get('checkodesol_XFAIL', False), + 'dsolve_too_slow':solver['examples'][example].get('dsolve_too_slow',False), + 'checkodesol_too_slow':solver['examples'][example].get('checkodesol_too_slow',False), + 'hint': solver['hint'] + } + examples.append(temp) + return examples + return inner() + + +def _ode_solver_test(ode_examples, run_slow_test=False): + for example in ode_examples: + if ((not run_slow_test) and example['slow']) or (run_slow_test and (not example['slow'])): + continue + + result = _test_particular_example(example['hint'], example, solver_flag=True) + if result['xpass_msg'] != "": + print(result['xpass_msg']) + + +def _test_all_hints(runxfail=False): + all_hints = list(allhints)+["default"] + all_examples = _get_all_examples() + + for our_hint in all_hints: + if our_hint.endswith('_Integral') or 'series' in our_hint: + continue + _test_all_examples_for_one_hint(our_hint, all_examples, runxfail) + + +def _test_dummy_sol(expected_sol,dsolve_sol): + if type(dsolve_sol)==list: + return any(expected_sol.dummy_eq(sub_dsol) for sub_dsol in dsolve_sol) + else: + return expected_sol.dummy_eq(dsolve_sol) + + +def _test_an_example(our_hint, example_name): + all_examples = _get_all_examples() + for example in all_examples: + if example['example_name'] == example_name: + _test_particular_example(our_hint, example) + + +def _test_particular_example(our_hint, ode_example, solver_flag=False): + eq = ode_example['eq'] + expected_sol = ode_example['sol'] + example = ode_example['example_name'] + xfail = our_hint in ode_example['XFAIL'] + func = ode_example['func'] + result = {'msg': '', 'xpass_msg': ''} + simplify_flag=ode_example['simplify_flag'] + checkodesol_XFAIL = ode_example['checkodesol_XFAIL'] + dsolve_too_slow = ode_example['dsolve_too_slow'] + checkodesol_too_slow = ode_example['checkodesol_too_slow'] + xpass = True + if solver_flag: + if our_hint not in classify_ode(eq, func): + message = hint_message.format(example=example, eq=eq, our_hint=our_hint) + raise AssertionError(message) + + if our_hint in classify_ode(eq, func): + result['match_list'] = example + try: + if not (dsolve_too_slow): + dsolve_sol = dsolve(eq, func, simplify=simplify_flag,hint=our_hint) + else: + if len(expected_sol)==1: + dsolve_sol = expected_sol[0] + else: + dsolve_sol = expected_sol + + except Exception as e: + dsolve_sol = [] + result['exception_list'] = example + if not solver_flag: + traceback.print_exc() + result['msg'] = exception_msg.format(e=str(e), hint=our_hint, example=example, eq=eq) + if solver_flag and not xfail: + print(result['msg']) + raise + xpass = False + + if solver_flag and dsolve_sol!=[]: + expect_sol_check = False + if type(dsolve_sol)==list: + for sub_sol in expected_sol: + if sub_sol.has(Dummy): + expect_sol_check = not _test_dummy_sol(sub_sol, dsolve_sol) + else: + expect_sol_check = sub_sol not in dsolve_sol + if expect_sol_check: + break + else: + expect_sol_check = dsolve_sol not in expected_sol + for sub_sol in expected_sol: + if sub_sol.has(Dummy): + expect_sol_check = not _test_dummy_sol(sub_sol, dsolve_sol) + + if expect_sol_check: + message = expected_sol_message.format(example=example, eq=eq, sol=expected_sol, dsolve_sol=dsolve_sol) + raise AssertionError(message) + + expected_checkodesol = [(True, 0) for i in range(len(expected_sol))] + if len(expected_sol) == 1: + expected_checkodesol = (True, 0) + + if not checkodesol_too_slow: + if not checkodesol_XFAIL: + if checkodesol(eq, dsolve_sol, func, solve_for_func=False) != expected_checkodesol: + result['unsolve_list'] = example + xpass = False + message = dsol_incorrect_msg.format(hint=our_hint, eq=eq, sol=expected_sol,dsolve_sol=dsolve_sol) + if solver_flag: + message = checkodesol_msg.format(example=example, eq=eq) + raise AssertionError(message) + else: + result['msg'] = 'AssertionError: ' + message + + if xpass and xfail: + result['xpass_msg'] = example + "is now passing for the hint" + our_hint + return result + + +def _test_all_examples_for_one_hint(our_hint, all_examples=[], runxfail=None): + if all_examples == []: + all_examples = _get_all_examples() + match_list, unsolve_list, exception_list = [], [], [] + for ode_example in all_examples: + xfail = our_hint in ode_example['XFAIL'] + if runxfail and not xfail: + continue + if xfail: + continue + result = _test_particular_example(our_hint, ode_example) + match_list += result.get('match_list',[]) + unsolve_list += result.get('unsolve_list',[]) + exception_list += result.get('exception_list',[]) + if runxfail is not None: + msg = result['msg'] + if msg!='': + print(result['msg']) + # print(result.get('xpass_msg','')) + if runxfail is None: + match_count = len(match_list) + solved = len(match_list)-len(unsolve_list)-len(exception_list) + msg = check_hint_msg.format(hint=our_hint, matched=match_count, solve=solved, unsolve=unsolve_list, exceptions=exception_list) + print(msg) + + +def test_SingleODESolver(): + # Test that not implemented methods give NotImplementedError + # Subclasses should override these methods. + problem = SingleODEProblem(f(x).diff(x), f(x), x) + solver = SingleODESolver(problem) + raises(NotImplementedError, lambda: solver.matches()) + raises(NotImplementedError, lambda: solver.get_general_solution()) + raises(NotImplementedError, lambda: solver._matches()) + raises(NotImplementedError, lambda: solver._get_general_solution()) + + # This ODE can not be solved by the FirstLinear solver. Here we test that + # it does not match and the asking for a general solution gives + # ODEMatchError + + problem = SingleODEProblem(f(x).diff(x) + f(x)*f(x), f(x), x) + + solver = FirstLinear(problem) + raises(ODEMatchError, lambda: solver.get_general_solution()) + + solver = FirstLinear(problem) + assert solver.matches() is False + + #These are just test for order of ODE + + problem = SingleODEProblem(f(x).diff(x) + f(x), f(x), x) + assert problem.order == 1 + + problem = SingleODEProblem(f(x).diff(x,4) + f(x).diff(x,2) - f(x).diff(x,3), f(x), x) + assert problem.order == 4 + + problem = SingleODEProblem(f(x).diff(x, 3) + f(x).diff(x, 2) - f(x)**2, f(x), x) + assert problem.is_autonomous == True + + problem = SingleODEProblem(f(x).diff(x, 3) + x*f(x).diff(x, 2) - f(x)**2, f(x), x) + assert problem.is_autonomous == False + + +def test_linear_coefficients(): + _ode_solver_test(_get_examples_ode_sol_linear_coefficients) + + +@slow +def test_1st_homogeneous_coeff_ode(): + #These were marked as test_1st_homogeneous_coeff_corner_case + eq1 = f(x).diff(x) - f(x)/x + c1 = classify_ode(eq1, f(x)) + eq2 = x*f(x).diff(x) - f(x) + c2 = classify_ode(eq2, f(x)) + sdi = "1st_homogeneous_coeff_subs_dep_div_indep" + sid = "1st_homogeneous_coeff_subs_indep_div_dep" + assert sid not in c1 and sdi not in c1 + assert sid not in c2 and sdi not in c2 + _ode_solver_test(_get_examples_ode_sol_1st_homogeneous_coeff_subs_dep_div_indep) + _ode_solver_test(_get_examples_ode_sol_1st_homogeneous_coeff_best) + + +@slow +def test_slow_examples_1st_homogeneous_coeff_ode(): + _ode_solver_test(_get_examples_ode_sol_1st_homogeneous_coeff_subs_dep_div_indep, run_slow_test=True) + _ode_solver_test(_get_examples_ode_sol_1st_homogeneous_coeff_best, run_slow_test=True) + + +@slow +def test_nth_linear_constant_coeff_homogeneous(): + _ode_solver_test(_get_examples_ode_sol_nth_linear_constant_coeff_homogeneous) + + +@slow +def test_slow_examples_nth_linear_constant_coeff_homogeneous(): + _ode_solver_test(_get_examples_ode_sol_nth_linear_constant_coeff_homogeneous, run_slow_test=True) + + +def test_Airy_equation(): + _ode_solver_test(_get_examples_ode_sol_2nd_linear_airy) + + +@slow +def test_lie_group(): + _ode_solver_test(_get_examples_ode_sol_lie_group) + + +@slow +def test_separable_reduced(): + df = f(x).diff(x) + eq = (x / f(x))*df + tan(x**2*f(x) / (x**2*f(x) - 1)) + assert classify_ode(eq) == ('factorable', 'separable_reduced', 'lie_group', + 'separable_reduced_Integral') + _ode_solver_test(_get_examples_ode_sol_separable_reduced) + + +@slow +def test_slow_examples_separable_reduced(): + _ode_solver_test(_get_examples_ode_sol_separable_reduced, run_slow_test=True) + + +@slow +def test_2nd_2F1_hypergeometric(): + _ode_solver_test(_get_examples_ode_sol_2nd_2F1_hypergeometric) + + +def test_2nd_2F1_hypergeometric_integral(): + eq = x*(x-1)*f(x).diff(x, 2) + (-1+ S(7)/2*x)*f(x).diff(x) + f(x) + sol = Eq(f(x), (C1 + C2*Integral(exp(Integral((1 - x/2)/(x*(x - 1)), x))/(1 - + x/2)**2, x))*exp(Integral(1/(x - 1), x)/4)*exp(-Integral(7/(x - + 1), x)/4)*hyper((S(1)/2, -1), (1,), x)) + assert sol == dsolve(eq, hint='2nd_hypergeometric_Integral') + assert checkodesol(eq, sol) == (True, 0) + + +@slow +def test_2nd_nonlinear_autonomous_conserved(): + _ode_solver_test(_get_examples_ode_sol_2nd_nonlinear_autonomous_conserved) + + +def test_2nd_nonlinear_autonomous_conserved_integral(): + eq = f(x).diff(x, 2) + asin(f(x)) + actual = [Eq(Integral(1/sqrt(C1 - 2*Integral(asin(_u), _u)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(C1 - 2*Integral(asin(_u), _u)), (_u, f(x))), C2 - x)] + solved = dsolve(eq, hint='2nd_nonlinear_autonomous_conserved_Integral', simplify=False) + for a,s in zip(actual, solved): + assert a.dummy_eq(s) + # checkodesol unable to simplify solutions with f(x) in an integral equation + assert checkodesol(eq, [s.doit() for s in solved]) == [(True, 0), (True, 0)] + + +@slow +def test_2nd_linear_bessel_equation(): + _ode_solver_test(_get_examples_ode_sol_2nd_linear_bessel) + + +@slow +def test_nth_algebraic(): + eqn = f(x) + f(x)*f(x).diff(x) + solns = [Eq(f(x), exp(x)), + Eq(f(x), C1*exp(C2*x))] + solns_final = _remove_redundant_solutions(eqn, solns, 2, x) + assert solns_final == [Eq(f(x), C1*exp(C2*x))] + + _ode_solver_test(_get_examples_ode_sol_nth_algebraic) + + +@slow +def test_slow_examples_nth_linear_constant_coeff_var_of_parameters(): + _ode_solver_test(_get_examples_ode_sol_nth_linear_var_of_parameters, run_slow_test=True) + + +def test_nth_linear_constant_coeff_var_of_parameters(): + _ode_solver_test(_get_examples_ode_sol_nth_linear_var_of_parameters) + + +@slow +def test_nth_linear_constant_coeff_variation_of_parameters__integral(): + # solve_variation_of_parameters shouldn't attempt to simplify the + # Wronskian if simplify=False. If wronskian() ever gets good enough + # to simplify the result itself, this test might fail. + our_hint = 'nth_linear_constant_coeff_variation_of_parameters_Integral' + eq = f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x) - 2*x - exp(I*x) + sol_simp = dsolve(eq, f(x), hint=our_hint, simplify=True) + sol_nsimp = dsolve(eq, f(x), hint=our_hint, simplify=False) + assert sol_simp != sol_nsimp + assert checkodesol(eq, sol_simp, order=5, solve_for_func=False) == (True, 0) + assert checkodesol(eq, sol_simp, order=5, solve_for_func=False) == (True, 0) + + +@slow +def test_slow_examples_1st_exact(): + _ode_solver_test(_get_examples_ode_sol_1st_exact, run_slow_test=True) + + +@slow +def test_1st_exact(): + _ode_solver_test(_get_examples_ode_sol_1st_exact) + + +def test_1st_exact_integral(): + eq = cos(f(x)) - (x*sin(f(x)) - f(x)**2)*f(x).diff(x) + sol_1 = dsolve(eq, f(x), simplify=False, hint='1st_exact_Integral') + assert checkodesol(eq, sol_1, order=1, solve_for_func=False) + + +@slow +def test_slow_examples_nth_order_reducible(): + _ode_solver_test(_get_examples_ode_sol_nth_order_reducible, run_slow_test=True) + + +@slow +def test_slow_examples_nth_linear_constant_coeff_undetermined_coefficients(): + _ode_solver_test(_get_examples_ode_sol_nth_linear_undetermined_coefficients, run_slow_test=True) + + +@slow +def test_slow_examples_separable(): + _ode_solver_test(_get_examples_ode_sol_separable, run_slow_test=True) + + +@slow +def test_nth_linear_constant_coeff_undetermined_coefficients(): + #issue-https://github.com/sympy/sympy/issues/5787 + # This test case is to show the classification of imaginary constants under + # nth_linear_constant_coeff_undetermined_coefficients + eq = Eq(diff(f(x), x), I*f(x) + S.Half - I) + our_hint = 'nth_linear_constant_coeff_undetermined_coefficients' + assert our_hint in classify_ode(eq) + _ode_solver_test(_get_examples_ode_sol_nth_linear_undetermined_coefficients) + + +def test_nth_order_reducible(): + F = lambda eq: NthOrderReducible(SingleODEProblem(eq, f(x), x))._matches() + D = Derivative + assert F(D(y*f(x), x, y) + D(f(x), x)) == False + assert F(D(y*f(y), y, y) + D(f(y), y)) == False + assert F(f(x)*D(f(x), x) + D(f(x), x, 2))== False + assert F(D(x*f(y), y, 2) + D(u*y*f(x), x, 3)) == False # no simplification by design + assert F(D(f(y), y, 2) + D(f(y), y, 3) + D(f(x), x, 4)) == False + assert F(D(f(x), x, 2) + D(f(x), x, 3)) == True + _ode_solver_test(_get_examples_ode_sol_nth_order_reducible) + + +@slow +def test_separable(): + _ode_solver_test(_get_examples_ode_sol_separable) + + +@slow +def test_factorable(): + assert integrate(-asin(f(2*x)+pi), x) == -Integral(asin(pi + f(2*x)), x) + _ode_solver_test(_get_examples_ode_sol_factorable) + + +@slow +def test_slow_examples_factorable(): + _ode_solver_test(_get_examples_ode_sol_factorable, run_slow_test=True) + + +def test_Riccati_special_minus2(): + _ode_solver_test(_get_examples_ode_sol_riccati) + + +@slow +def test_1st_rational_riccati(): + _ode_solver_test(_get_examples_ode_sol_1st_rational_riccati) + + +def test_Bernoulli(): + _ode_solver_test(_get_examples_ode_sol_bernoulli) + + +def test_1st_linear(): + _ode_solver_test(_get_examples_ode_sol_1st_linear) + + +def test_almost_linear(): + _ode_solver_test(_get_examples_ode_sol_almost_linear) + + +@slow +def test_Liouville_ODE(): + hint = 'Liouville' + not_Liouville1 = classify_ode(diff(f(x), x)/x + f(x)*diff(f(x), x, x)/2 - + diff(f(x), x)**2/2, f(x)) + not_Liouville2 = classify_ode(diff(f(x), x)/x + diff(f(x), x, x)/2 - + x*diff(f(x), x)**2/2, f(x)) + assert hint not in not_Liouville1 + assert hint not in not_Liouville2 + assert hint + '_Integral' not in not_Liouville1 + assert hint + '_Integral' not in not_Liouville2 + + _ode_solver_test(_get_examples_ode_sol_liouville) + + +def test_nth_order_linear_euler_eq_homogeneous(): + x, t, a, b, c = symbols('x t a b c') + y = Function('y') + our_hint = "nth_linear_euler_eq_homogeneous" + + eq = diff(f(t), t, 4)*t**4 - 13*diff(f(t), t, 2)*t**2 + 36*f(t) + assert our_hint in classify_ode(eq) + + eq = a*y(t) + b*t*diff(y(t), t) + c*t**2*diff(y(t), t, 2) + assert our_hint in classify_ode(eq) + + _ode_solver_test(_get_examples_ode_sol_euler_homogeneous) + + +def test_nth_order_linear_euler_eq_nonhomogeneous_undetermined_coefficients(): + x, t = symbols('x t') + a, b, c, d = symbols('a b c d', integer=True) + our_hint = "nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients" + + eq = x**4*diff(f(x), x, 4) - 13*x**2*diff(f(x), x, 2) + 36*f(x) + x + assert our_hint in classify_ode(eq, f(x)) + + eq = a*x**2*diff(f(x), x, 2) + b*x*diff(f(x), x) + c*f(x) + d*log(x) + assert our_hint in classify_ode(eq, f(x)) + + _ode_solver_test(_get_examples_ode_sol_euler_undetermined_coeff) + + +@slow +def test_nth_order_linear_euler_eq_nonhomogeneous_variation_of_parameters(): + x, t = symbols('x, t') + a, b, c, d = symbols('a, b, c, d', integer=True) + our_hint = "nth_linear_euler_eq_nonhomogeneous_variation_of_parameters" + + eq = Eq(x**2*diff(f(x),x,2) - 8*x*diff(f(x),x) + 12*f(x), x**2) + assert our_hint in classify_ode(eq, f(x)) + + eq = Eq(a*x**3*diff(f(x),x,3) + b*x**2*diff(f(x),x,2) + c*x*diff(f(x),x) + d*f(x), x*log(x)) + assert our_hint in classify_ode(eq, f(x)) + + _ode_solver_test(_get_examples_ode_sol_euler_var_para) + + +@_add_example_keys +def _get_examples_ode_sol_euler_homogeneous(): + r1, r2, r3, r4, r5 = [rootof(x**5 - 14*x**4 + 71*x**3 - 154*x**2 + 120*x - 1, n) for n in range(5)] + return { + 'hint': "nth_linear_euler_eq_homogeneous", + 'func': f(x), + 'examples':{ + 'euler_hom_01': { + 'eq': Eq(-3*diff(f(x), x)*x + 2*x**2*diff(f(x), x, x), 0), + 'sol': [Eq(f(x), C1 + C2*x**Rational(5, 2))], + }, + + 'euler_hom_02': { + 'eq': Eq(3*f(x) - 5*diff(f(x), x)*x + 2*x**2*diff(f(x), x, x), 0), + 'sol': [Eq(f(x), C1*sqrt(x) + C2*x**3)] + }, + + 'euler_hom_03': { + 'eq': Eq(4*f(x) + 5*diff(f(x), x)*x + x**2*diff(f(x), x, x), 0), + 'sol': [Eq(f(x), (C1 + C2*log(x))/x**2)] + }, + + 'euler_hom_04': { + 'eq': Eq(6*f(x) - 6*diff(f(x), x)*x + 1*x**2*diff(f(x), x, x) + x**3*diff(f(x), x, x, x), 0), + 'sol': [Eq(f(x), C1/x**2 + C2*x + C3*x**3)] + }, + + 'euler_hom_05': { + 'eq': Eq(-125*f(x) + 61*diff(f(x), x)*x - 12*x**2*diff(f(x), x, x) + x**3*diff(f(x), x, x, x), 0), + 'sol': [Eq(f(x), x**5*(C1 + C2*log(x) + C3*log(x)**2))] + }, + + 'euler_hom_06': { + 'eq': x**2*diff(f(x), x, 2) + x*diff(f(x), x) - 9*f(x), + 'sol': [Eq(f(x), C1*x**-3 + C2*x**3)] + }, + + 'euler_hom_07': { + 'eq': sin(x)*x**2*f(x).diff(x, 2) + sin(x)*x*f(x).diff(x) + sin(x)*f(x), + 'sol': [Eq(f(x), C1*sin(log(x)) + C2*cos(log(x)))], + 'XFAIL': ['2nd_power_series_regular','nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients'] + }, + + 'euler_hom_08': { + 'eq': x**6 * f(x).diff(x, 6) - x*f(x).diff(x) + f(x), + 'sol': [Eq(f(x), C1*x + C2*x**r1 + C3*x**r2 + C4*x**r3 + C5*x**r4 + C6*x**r5)], + 'checkodesol_XFAIL':True + }, + + #This example is from issue: https://github.com/sympy/sympy/issues/15237 #This example is from issue: + # https://github.com/sympy/sympy/issues/15237 + 'euler_hom_09': { + 'eq': Derivative(x*f(x), x, x, x), + 'sol': [Eq(f(x), C1 + C2/x + C3*x)], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_euler_undetermined_coeff(): + return { + 'hint': "nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients", + 'func': f(x), + 'examples':{ + 'euler_undet_01': { + 'eq': Eq(x**2*diff(f(x), x, x) + x*diff(f(x), x), 1), + 'sol': [Eq(f(x), C1 + C2*log(x) + log(x)**2/2)] + }, + + 'euler_undet_02': { + 'eq': Eq(x**2*diff(f(x), x, x) - 2*x*diff(f(x), x) + 2*f(x), x**3), + 'sol': [Eq(f(x), x*(C1 + C2*x + Rational(1, 2)*x**2))] + }, + + 'euler_undet_03': { + 'eq': Eq(x**2*diff(f(x), x, x) - x*diff(f(x), x) - 3*f(x), log(x)/x), + 'sol': [Eq(f(x), (C1 + C2*x**4 - log(x)**2/8 - log(x)/16)/x)] + }, + + 'euler_undet_04': { + 'eq': Eq(x**2*diff(f(x), x, x) + 3*x*diff(f(x), x) - 8*f(x), log(x)**3 - log(x)), + 'sol': [Eq(f(x), C1/x**4 + C2*x**2 - Rational(1,8)*log(x)**3 - Rational(3,32)*log(x)**2 - Rational(1,64)*log(x) - Rational(7, 256))] + }, + + 'euler_undet_05': { + 'eq': Eq(x**3*diff(f(x), x, x, x) - 3*x**2*diff(f(x), x, x) + 6*x*diff(f(x), x) - 6*f(x), log(x)), + 'sol': [Eq(f(x), C1*x + C2*x**2 + C3*x**3 - Rational(1, 6)*log(x) - Rational(11, 36))] + }, + + #Below examples were added for the issue: https://github.com/sympy/sympy/issues/5096 + 'euler_undet_06': { + 'eq': 2*x**2*f(x).diff(x, 2) + f(x) + sqrt(2*x)*sin(log(2*x)/2), + 'sol': [Eq(f(x), sqrt(x)*(C1*sin(log(x)/2) + C2*cos(log(x)/2) + sqrt(2)*log(x)*cos(log(2*x)/2)/2))] + }, + + 'euler_undet_07': { + 'eq': 2*x**2*f(x).diff(x, 2) + f(x) + sin(log(2*x)/2), + 'sol': [Eq(f(x), C1*sqrt(x)*sin(log(x)/2) + C2*sqrt(x)*cos(log(x)/2) - 2*sin(log(2*x)/2)/5 - 4*cos(log(2*x)/2)/5)] + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_euler_var_para(): + return { + 'hint': "nth_linear_euler_eq_nonhomogeneous_variation_of_parameters", + 'func': f(x), + 'examples':{ + 'euler_var_01': { + 'eq': Eq(x**2*Derivative(f(x), x, x) - 2*x*Derivative(f(x), x) + 2*f(x), x**4), + 'sol': [Eq(f(x), x*(C1 + C2*x + x**3/6))] + }, + + 'euler_var_02': { + 'eq': Eq(3*x**2*diff(f(x), x, x) + 6*x*diff(f(x), x) - 6*f(x), x**3*exp(x)), + 'sol': [Eq(f(x), C1/x**2 + C2*x + x*exp(x)/3 - 4*exp(x)/3 + 8*exp(x)/(3*x) - 8*exp(x)/(3*x**2))] + }, + + 'euler_var_03': { + 'eq': Eq(x**2*Derivative(f(x), x, x) - 2*x*Derivative(f(x), x) + 2*f(x), x**4*exp(x)), + 'sol': [Eq(f(x), x*(C1 + C2*x + x*exp(x) - 2*exp(x)))] + }, + + 'euler_var_04': { + 'eq': x**2*Derivative(f(x), x, x) - 2*x*Derivative(f(x), x) + 2*f(x) - log(x), + 'sol': [Eq(f(x), C1*x + C2*x**2 + log(x)/2 + Rational(3, 4))] + }, + + 'euler_var_05': { + 'eq': -exp(x) + (x*Derivative(f(x), (x, 2)) + Derivative(f(x), x))/x, + 'sol': [Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x))] + }, + + 'euler_var_06': { + 'eq': x**2 * f(x).diff(x, 2) + x * f(x).diff(x) + 4 * f(x) - 1/x, + 'sol': [Eq(f(x), C1*sin(2*log(x)) + C2*cos(2*log(x)) + 1/(5*x))] + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_bernoulli(): + # Type: Bernoulli, f'(x) + p(x)*f(x) == q(x)*f(x)**n + return { + 'hint': "Bernoulli", + 'func': f(x), + 'examples':{ + 'bernoulli_01': { + 'eq': Eq(x*f(x).diff(x) + f(x) - f(x)**2, 0), + 'sol': [Eq(f(x), 1/(C1*x + 1))], + 'XFAIL': ['separable_reduced'] + }, + + 'bernoulli_02': { + 'eq': f(x).diff(x) - y*f(x), + 'sol': [Eq(f(x), C1*exp(x*y))] + }, + + 'bernoulli_03': { + 'eq': f(x)*f(x).diff(x) - 1, + 'sol': [Eq(f(x), -sqrt(C1 + 2*x)), Eq(f(x), sqrt(C1 + 2*x))] + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_riccati(): + # Type: Riccati special alpha = -2, a*dy/dx + b*y**2 + c*y/x +d/x**2 + return { + 'hint': "Riccati_special_minus2", + 'func': f(x), + 'examples':{ + 'riccati_01': { + 'eq': 2*f(x).diff(x) + f(x)**2 - f(x)/x + 3*x**(-2), + 'sol': [Eq(f(x), (-sqrt(3)*tan(C1 + sqrt(3)*log(x)/4) + 3)/(2*x))], + }, + }, + } + + +@_add_example_keys +def _get_examples_ode_sol_1st_rational_riccati(): + # Type: 1st Order Rational Riccati, dy/dx = a + b*y + c*y**2, + # a, b, c are rational functions of x + return { + 'hint': "1st_rational_riccati", + 'func': f(x), + 'examples':{ + # a(x) is a constant + "rational_riccati_01": { + "eq": Eq(f(x).diff(x) + f(x)**2 - 2, 0), + "sol": [Eq(f(x), sqrt(2)*(-C1 - exp(2*sqrt(2)*x))/(C1 - exp(2*sqrt(2)*x)))] + }, + # a(x) is a constant + "rational_riccati_02": { + "eq": f(x)**2 + Derivative(f(x), x) + 4*f(x)/x + 2/x**2, + "sol": [Eq(f(x), (-2*C1 - x)/(x*(C1 + x)))] + }, + # a(x) is a constant + "rational_riccati_03": { + "eq": 2*x**2*Derivative(f(x), x) - x*(4*f(x) + Derivative(f(x), x) - 4) + (f(x) - 1)*f(x), + "sol": [Eq(f(x), (C1 + 2*x**2)/(C1 + x))] + }, + # Constant coefficients + "rational_riccati_04": { + "eq": f(x).diff(x) - 6 - 5*f(x) - f(x)**2, + "sol": [Eq(f(x), (-2*C1 + 3*exp(x))/(C1 - exp(x)))] + }, + # One pole of multiplicity 2 + "rational_riccati_05": { + "eq": x**2 - (2*x + 1/x)*f(x) + f(x)**2 + Derivative(f(x), x), + "sol": [Eq(f(x), x*(C1 + x**2 + 1)/(C1 + x**2 - 1))] + }, + # One pole of multiplicity 2 + "rational_riccati_06": { + "eq": x**4*Derivative(f(x), x) + x**2 - x*(2*f(x)**2 + Derivative(f(x), x)) + f(x), + "sol": [Eq(f(x), x*(C1*x - x + 1)/(C1 + x**2 - 1))] + }, + # Multiple poles of multiplicity 2 + "rational_riccati_07": { + "eq": -f(x)**2 + Derivative(f(x), x) + (15*x**2 - 20*x + 7)/((x - 1)**2*(2*x \ + - 1)**2), + "sol": [Eq(f(x), (9*C1*x - 6*C1 - 15*x**5 + 60*x**4 - 94*x**3 + 72*x**2 - \ + 33*x + 8)/(6*C1*x**2 - 9*C1*x + 3*C1 + 6*x**6 - 29*x**5 + 57*x**4 - \ + 58*x**3 + 28*x**2 - 3*x - 1))] + }, + # Imaginary poles + "rational_riccati_08": { + "eq": Derivative(f(x), x) + (3*x**2 + 1)*f(x)**2/x + (6*x**2 - x + 3)*f(x)/(x*(x \ + - 1)) + (3*x**2 - 2*x + 2)/(x*(x - 1)**2), + "sol": [Eq(f(x), (-C1 - x**3 + x**2 - 2*x + 1)/(C1*x - C1 + x**4 - x**3 + x**2 - \ + 2*x + 1))], + }, + # Imaginary coefficients in equation + "rational_riccati_09": { + "eq": Derivative(f(x), x) - 2*I*(f(x)**2 + 1)/x, + "sol": [Eq(f(x), (-I*C1 + I*x**4 + I)/(C1 + x**4 - 1))] + }, + # Regression: linsolve returning empty solution + # Large value of m (> 10) + "rational_riccati_10": { + "eq": Eq(Derivative(f(x), x), x*f(x)/(S(3)/2 - 2*x) + (x/2 - S(1)/3)*f(x)**2/\ + (2*x/3 - S(1)/2) - S(5)/4 + (281*x**2 - 1260*x + 756)/(16*x**3 - 12*x**2)), + "sol": [Eq(f(x), (40*C1*x**14 + 28*C1*x**13 + 420*C1*x**12 + 2940*C1*x**11 + \ + 18480*C1*x**10 + 103950*C1*x**9 + 519750*C1*x**8 + 2286900*C1*x**7 + \ + 8731800*C1*x**6 + 28378350*C1*x**5 + 76403250*C1*x**4 + 163721250*C1*x**3 \ + + 261954000*C1*x**2 + 278326125*C1*x + 147349125*C1 + x*exp(2*x) - 9*exp(2*x) \ + )/(x*(24*C1*x**13 + 140*C1*x**12 + 840*C1*x**11 + 4620*C1*x**10 + 23100*C1*x**9 \ + + 103950*C1*x**8 + 415800*C1*x**7 + 1455300*C1*x**6 + 4365900*C1*x**5 + \ + 10914750*C1*x**4 + 21829500*C1*x**3 + 32744250*C1*x**2 + 32744250*C1*x + \ + 16372125*C1 - exp(2*x))))] + } + } + } + + + +@_add_example_keys +def _get_examples_ode_sol_1st_linear(): + # Type: first order linear form f'(x)+p(x)f(x)=q(x) + return { + 'hint': "1st_linear", + 'func': f(x), + 'examples':{ + 'linear_01': { + 'eq': Eq(f(x).diff(x) + x*f(x), x**2), + 'sol': [Eq(f(x), (C1 + x*exp(x**2/2)- sqrt(2)*sqrt(pi)*erfi(sqrt(2)*x/2)/2)*exp(-x**2/2))], + }, + }, + } + + +@_add_example_keys +def _get_examples_ode_sol_factorable(): + """ some hints are marked as xfail for examples because they missed additional algebraic solution + which could be found by Factorable hint. Fact_01 raise exception for + nth_linear_constant_coeff_undetermined_coefficients""" + + y = Dummy('y') + a0,a1,a2,a3,a4 = symbols('a0, a1, a2, a3, a4') + return { + 'hint': "factorable", + 'func': f(x), + 'examples':{ + 'fact_01': { + 'eq': f(x) + f(x)*f(x).diff(x), + 'sol': [Eq(f(x), 0), Eq(f(x), C1 - x)], + 'XFAIL': ['separable', '1st_exact', '1st_linear', 'Bernoulli', '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', '1st_homogeneous_coeff_subs_dep_div_indep', + 'lie_group', 'nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + 'nth_linear_euler_eq_nonhomogeneous_variation_of_parameters', + 'nth_linear_constant_coeff_undetermined_coefficients'] + }, + + 'fact_02': { + 'eq': f(x)*(f(x).diff(x)+f(x)*x+2), + 'sol': [Eq(f(x), (C1 - sqrt(2)*sqrt(pi)*erfi(sqrt(2)*x/2))*exp(-x**2/2)), Eq(f(x), 0)], + 'XFAIL': ['Bernoulli', '1st_linear', 'lie_group'] + }, + + 'fact_03': { + 'eq': (f(x).diff(x)+f(x)*x**2)*(f(x).diff(x, 2) + x*f(x)), + 'sol': [Eq(f(x), C1*airyai(-x) + C2*airybi(-x)),Eq(f(x), C1*exp(-x**3/3))] + }, + + 'fact_04': { + 'eq': (f(x).diff(x)+f(x)*x**2)*(f(x).diff(x, 2) + f(x)), + 'sol': [Eq(f(x), C1*exp(-x**3/3)), Eq(f(x), C1*sin(x) + C2*cos(x))] + }, + + 'fact_05': { + 'eq': (f(x).diff(x)**2-1)*(f(x).diff(x)**2-4), + 'sol': [Eq(f(x), C1 - x), Eq(f(x), C1 + x), Eq(f(x), C1 + 2*x), Eq(f(x), C1 - 2*x)] + }, + + 'fact_06': { + 'eq': (f(x).diff(x, 2)-exp(f(x)))*f(x).diff(x), + 'sol': [ + Eq(f(x), log(-C1/(cos(sqrt(-C1)*(C2 + x)) + 1))), + Eq(f(x), log(-C1/(cos(sqrt(-C1)*(C2 - x)) + 1))), + Eq(f(x), C1) + ], + 'slow': True, + }, + + 'fact_07': { + 'eq': (f(x).diff(x)**2-1)*(f(x)*f(x).diff(x)-1), + 'sol': [Eq(f(x), C1 - x), Eq(f(x), -sqrt(C1 + 2*x)),Eq(f(x), sqrt(C1 + 2*x)), Eq(f(x), C1 + x)] + }, + + 'fact_08': { + 'eq': Derivative(f(x), x)**4 - 2*Derivative(f(x), x)**2 + 1, + 'sol': [Eq(f(x), C1 - x), Eq(f(x), C1 + x)] + }, + + 'fact_09': { + 'eq': f(x)**2*Derivative(f(x), x)**6 - 2*f(x)**2*Derivative(f(x), + x)**4 + f(x)**2*Derivative(f(x), x)**2 - 2*f(x)*Derivative(f(x), + x)**5 + 4*f(x)*Derivative(f(x), x)**3 - 2*f(x)*Derivative(f(x), + x) + Derivative(f(x), x)**4 - 2*Derivative(f(x), x)**2 + 1, + 'sol': [ + Eq(f(x), C1 - x), Eq(f(x), -sqrt(C1 + 2*x)), + Eq(f(x), sqrt(C1 + 2*x)), Eq(f(x), C1 + x) + ] + }, + + 'fact_10': { + 'eq': x**4*f(x)**2 + 2*x**4*f(x)*Derivative(f(x), (x, 2)) + x**4*Derivative(f(x), + (x, 2))**2 + 2*x**3*f(x)*Derivative(f(x), x) + 2*x**3*Derivative(f(x), + x)*Derivative(f(x), (x, 2)) - 7*x**2*f(x)**2 - 7*x**2*f(x)*Derivative(f(x), + (x, 2)) + x**2*Derivative(f(x), x)**2 - 7*x*f(x)*Derivative(f(x), x) + 12*f(x)**2, + 'sol': [ + Eq(f(x), C1*besselj(2, x) + C2*bessely(2, x)), + Eq(f(x), C1*besselj(sqrt(3), x) + C2*bessely(sqrt(3), x)) + ], + 'slow': True, + }, + + 'fact_11': { + 'eq': (f(x).diff(x, 2)-exp(f(x)))*(f(x).diff(x, 2)+exp(f(x))), + 'sol': [ + Eq(f(x), log(C1/(cos(C1*sqrt(-1/C1)*(C2 + x)) - 1))), + Eq(f(x), log(C1/(cos(C1*sqrt(-1/C1)*(C2 - x)) - 1))), + Eq(f(x), log(C1/(1 - cos(C1*sqrt(-1/C1)*(C2 + x))))), + Eq(f(x), log(C1/(1 - cos(C1*sqrt(-1/C1)*(C2 - x))))) + ], + 'dsolve_too_slow': True, + }, + + #Below examples were added for the issue: https://github.com/sympy/sympy/issues/15889 + 'fact_12': { + 'eq': exp(f(x).diff(x))-f(x)**2, + 'sol': [Eq(NonElementaryIntegral(1/log(y**2), (y, f(x))), C1 + x)], + 'XFAIL': ['lie_group'] #It shows not implemented error for lie_group. + }, + + 'fact_13': { + 'eq': f(x).diff(x)**2 - f(x)**3, + 'sol': [Eq(f(x), 4/(C1**2 - 2*C1*x + x**2))], + 'XFAIL': ['lie_group'] #It shows not implemented error for lie_group. + }, + + 'fact_14': { + 'eq': f(x).diff(x)**2 - f(x), + 'sol': [Eq(f(x), C1**2/4 - C1*x/2 + x**2/4)] + }, + + 'fact_15': { + 'eq': f(x).diff(x)**2 - f(x)**2, + 'sol': [Eq(f(x), C1*exp(x)), Eq(f(x), C1*exp(-x))] + }, + + 'fact_16': { + 'eq': f(x).diff(x)**2 - f(x)**3, + 'sol': [Eq(f(x), 4/(C1**2 - 2*C1*x + x**2))], + }, + + # kamke ode 1.1 + 'fact_17': { + 'eq': f(x).diff(x)-(a4*x**4 + a3*x**3 + a2*x**2 + a1*x + a0)**(-1/2), + 'sol': [Eq(f(x), C1 + Integral(1/sqrt(a0 + a1*x + a2*x**2 + a3*x**3 + a4*x**4), x))], + 'slow': True + }, + + # This is from issue: https://github.com/sympy/sympy/issues/9446 + 'fact_18':{ + 'eq': Eq(f(2 * x), sin(Derivative(f(x)))), + 'sol': [Eq(f(x), C1 + Integral(pi - asin(f(2*x)), x)), Eq(f(x), C1 + Integral(asin(f(2*x)), x))], + 'checkodesol_XFAIL':True + }, + + # This is from issue: https://github.com/sympy/sympy/issues/7093 + 'fact_19': { + 'eq': Derivative(f(x), x)**2 - x**3, + 'sol': [Eq(f(x), C1 - 2*x**Rational(5,2)/5), Eq(f(x), C1 + 2*x**Rational(5,2)/5)], + }, + + 'fact_20': { + 'eq': x*f(x).diff(x, 2) - x*f(x), + 'sol': [Eq(f(x), C1*exp(-x) + C2*exp(x))], + }, + } + } + + + +@_add_example_keys +def _get_examples_ode_sol_almost_linear(): + from sympy.functions.special.error_functions import Ei + A = Symbol('A', positive=True) + f = Function('f') + d = f(x).diff(x) + + return { + 'hint': "almost_linear", + 'func': f(x), + 'examples':{ + 'almost_lin_01': { + 'eq': x**2*f(x)**2*d + f(x)**3 + 1, + 'sol': [Eq(f(x), (C1*exp(3/x) - 1)**Rational(1, 3)), + Eq(f(x), (-1 - sqrt(3)*I)*(C1*exp(3/x) - 1)**Rational(1, 3)/2), + Eq(f(x), (-1 + sqrt(3)*I)*(C1*exp(3/x) - 1)**Rational(1, 3)/2)], + + }, + + 'almost_lin_02': { + 'eq': x*f(x)*d + 2*x*f(x)**2 + 1, + 'sol': [Eq(f(x), -sqrt((C1 - 2*Ei(4*x))*exp(-4*x))), Eq(f(x), sqrt((C1 - 2*Ei(4*x))*exp(-4*x)))] + }, + + 'almost_lin_03': { + 'eq': x*d + x*f(x) + 1, + 'sol': [Eq(f(x), (C1 - Ei(x))*exp(-x))] + }, + + 'almost_lin_04': { + 'eq': x*exp(f(x))*d + exp(f(x)) + 3*x, + 'sol': [Eq(f(x), log(C1/x - x*Rational(3, 2)))], + }, + + 'almost_lin_05': { + 'eq': x + A*(x + diff(f(x), x) + f(x)) + diff(f(x), x) + f(x) + 2, + 'sol': [Eq(f(x), (C1 + Piecewise( + (x, Eq(A + 1, 0)), ((-A*x + A - x - 1)*exp(x)/(A + 1), True)))*exp(-x))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_liouville(): + n = Symbol('n') + _y = Dummy('y') + return { + 'hint': "Liouville", + 'func': f(x), + 'examples':{ + 'liouville_01': { + 'eq': diff(f(x), x)/x + diff(f(x), x, x)/2 - diff(f(x), x)**2/2, + 'sol': [Eq(f(x), log(x/(C1 + C2*x)))], + + }, + + 'liouville_02': { + 'eq': diff(x*exp(-f(x)), x, x), + 'sol': [Eq(f(x), log(x/(C1 + C2*x)))] + }, + + 'liouville_03': { + 'eq': ((diff(f(x), x)/x + diff(f(x), x, x)/2 - diff(f(x), x)**2/2)*exp(-f(x))/exp(f(x))).expand(), + 'sol': [Eq(f(x), log(x/(C1 + C2*x)))] + }, + + 'liouville_04': { + 'eq': diff(f(x), x, x) + 1/f(x)*(diff(f(x), x))**2 + 1/x*diff(f(x), x), + 'sol': [Eq(f(x), -sqrt(C1 + C2*log(x))), Eq(f(x), sqrt(C1 + C2*log(x)))], + }, + + 'liouville_05': { + 'eq': x*diff(f(x), x, x) + x/f(x)*diff(f(x), x)**2 + x*diff(f(x), x), + 'sol': [Eq(f(x), -sqrt(C1 + C2*exp(-x))), Eq(f(x), sqrt(C1 + C2*exp(-x)))], + }, + + 'liouville_06': { + 'eq': Eq((x*exp(f(x))).diff(x, x), 0), + 'sol': [Eq(f(x), log(C1 + C2/x))], + }, + + 'liouville_07': { + 'eq': (diff(f(x), x)/x + diff(f(x), x, x)/2 - diff(f(x), x)**2/2)*exp(-f(x))/exp(f(x)), + 'sol': [Eq(f(x), log(x/(C1 + C2*x)))], + }, + + 'liouville_08': { + 'eq': x**2*diff(f(x),x) + (n*f(x) + f(x)**2)*diff(f(x),x)**2 + diff(f(x), (x, 2)), + 'sol': [Eq(C1 + C2*lowergamma(Rational(1,3), x**3/3) + NonElementaryIntegral(exp(_y**3/3)*exp(_y**2*n/2), (_y, f(x))), 0)], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_nth_algebraic(): + M, m, r, t = symbols('M m r t') + phi = Function('phi') + k = Symbol('k') + # This one needs a substitution f' = g. + # 'algeb_12': { + # 'eq': -exp(x) + (x*Derivative(f(x), (x, 2)) + Derivative(f(x), x))/x, + # 'sol': [Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x))], + # }, + return { + 'hint': "nth_algebraic", + 'func': f(x), + 'examples':{ + 'algeb_01': { + 'eq': f(x) * f(x).diff(x) * f(x).diff(x, x) * (f(x) - 1) * (f(x).diff(x) - x), + 'sol': [Eq(f(x), C1 + x**2/2), Eq(f(x), C1 + C2*x)] + }, + + 'algeb_02': { + 'eq': f(x) * f(x).diff(x) * f(x).diff(x, x) * (f(x) - 1), + 'sol': [Eq(f(x), C1 + C2*x)] + }, + + 'algeb_03': { + 'eq': f(x) * f(x).diff(x) * f(x).diff(x, x), + 'sol': [Eq(f(x), C1 + C2*x)] + }, + + 'algeb_04': { + 'eq': Eq(-M * phi(t).diff(t), + Rational(3, 2) * m * r**2 * phi(t).diff(t) * phi(t).diff(t,t)), + 'sol': [Eq(phi(t), C1), Eq(phi(t), C1 + C2*t - M*t**2/(3*m*r**2))], + 'func': phi(t) + }, + + 'algeb_05': { + 'eq': (1 - sin(f(x))) * f(x).diff(x), + 'sol': [Eq(f(x), C1)], + 'XFAIL': ['separable'] #It raised exception. + }, + + 'algeb_06': { + 'eq': (diff(f(x)) - x)*(diff(f(x)) + x), + 'sol': [Eq(f(x), C1 - x**2/2), Eq(f(x), C1 + x**2/2)] + }, + + 'algeb_07': { + 'eq': Eq(Derivative(f(x), x), Derivative(g(x), x)), + 'sol': [Eq(f(x), C1 + g(x))], + }, + + 'algeb_08': { + 'eq': f(x).diff(x) - C1, #this example is from issue 15999 + 'sol': [Eq(f(x), C1*x + C2)], + }, + + 'algeb_09': { + 'eq': f(x)*f(x).diff(x), + 'sol': [Eq(f(x), C1)], + }, + + 'algeb_10': { + 'eq': (diff(f(x)) - x)*(diff(f(x)) + x), + 'sol': [Eq(f(x), C1 - x**2/2), Eq(f(x), C1 + x**2/2)], + }, + + 'algeb_11': { + 'eq': f(x) + f(x)*f(x).diff(x), + 'sol': [Eq(f(x), 0), Eq(f(x), C1 - x)], + 'XFAIL': ['separable', '1st_exact', '1st_linear', 'Bernoulli', '1st_homogeneous_coeff_best', + '1st_homogeneous_coeff_subs_indep_div_dep', '1st_homogeneous_coeff_subs_dep_div_indep', + 'lie_group', 'nth_linear_constant_coeff_undetermined_coefficients', + 'nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients', + 'nth_linear_constant_coeff_variation_of_parameters', + 'nth_linear_euler_eq_nonhomogeneous_variation_of_parameters'] + #nth_linear_constant_coeff_undetermined_coefficients raises exception rest all of them misses a solution. + }, + + 'algeb_12': { + 'eq': Derivative(x*f(x), x, x, x), + 'sol': [Eq(f(x), (C1 + C2*x + C3*x**2) / x)], + 'XFAIL': ['nth_algebraic'] # It passes only when prep=False is set in dsolve. + }, + + 'algeb_13': { + 'eq': Eq(Derivative(x*Derivative(f(x), x), x)/x, exp(x)), + 'sol': [Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x))], + 'XFAIL': ['nth_algebraic'] # It passes only when prep=False is set in dsolve. + }, + + # These are simple tests from the old ode module example 14-18 + 'algeb_14': { + 'eq': Eq(f(x).diff(x), 0), + 'sol': [Eq(f(x), C1)], + }, + + 'algeb_15': { + 'eq': Eq(3*f(x).diff(x) - 5, 0), + 'sol': [Eq(f(x), C1 + x*Rational(5, 3))], + }, + + 'algeb_16': { + 'eq': Eq(3*f(x).diff(x), 5), + 'sol': [Eq(f(x), C1 + x*Rational(5, 3))], + }, + + # Type: 2nd order, constant coefficients (two complex roots) + 'algeb_17': { + 'eq': Eq(3*f(x).diff(x) - 1, 0), + 'sol': [Eq(f(x), C1 + x/3)], + }, + + 'algeb_18': { + 'eq': Eq(x*f(x).diff(x) - 1, 0), + 'sol': [Eq(f(x), C1 + log(x))], + }, + + # https://github.com/sympy/sympy/issues/6989 + 'algeb_19': { + 'eq': f(x).diff(x) - x*exp(-k*x), + 'sol': [Eq(f(x), C1 + Piecewise(((-k*x - 1)*exp(-k*x)/k**2, Ne(k**2, 0)),(x**2/2, True)))], + }, + + 'algeb_20': { + 'eq': -f(x).diff(x) + x*exp(-k*x), + 'sol': [Eq(f(x), C1 + Piecewise(((-k*x - 1)*exp(-k*x)/k**2, Ne(k**2, 0)),(x**2/2, True)))], + }, + + # https://github.com/sympy/sympy/issues/10867 + 'algeb_21': { + 'eq': Eq(g(x).diff(x).diff(x), (x-2)**2 + (x-3)**3), + 'sol': [Eq(g(x), C1 + C2*x + x**5/20 - 2*x**4/3 + 23*x**3/6 - 23*x**2/2)], + 'func': g(x), + }, + + # https://github.com/sympy/sympy/issues/13691 + 'algeb_22': { + 'eq': f(x).diff(x) - C1*g(x).diff(x), + 'sol': [Eq(f(x), C2 + C1*g(x))], + 'func': f(x), + }, + + # https://github.com/sympy/sympy/issues/4838 + 'algeb_23': { + 'eq': f(x).diff(x) - 3*C1 - 3*x**2, + 'sol': [Eq(f(x), C2 + 3*C1*x + x**3)], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_nth_order_reducible(): + return { + 'hint': "nth_order_reducible", + 'func': f(x), + 'examples':{ + 'reducible_01': { + 'eq': Eq(x*Derivative(f(x), x)**2 + Derivative(f(x), x, 2), 0), + 'sol': [Eq(f(x),C1 - sqrt(-1/C2)*log(-C2*sqrt(-1/C2) + x) + + sqrt(-1/C2)*log(C2*sqrt(-1/C2) + x))], + 'slow': True, + }, + + 'reducible_02': { + 'eq': -exp(x) + (x*Derivative(f(x), (x, 2)) + Derivative(f(x), x))/x, + 'sol': [Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x))], + 'slow': True, + }, + + 'reducible_03': { + 'eq': Eq(sqrt(2) * f(x).diff(x,x,x) + f(x).diff(x), 0), + 'sol': [Eq(f(x), C1 + C2*sin(2**Rational(3, 4)*x/2) + C3*cos(2**Rational(3, 4)*x/2))], + 'slow': True, + }, + + 'reducible_04': { + 'eq': f(x).diff(x, 2) + 2*f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*exp(-2*x))], + }, + + 'reducible_05': { + 'eq': f(x).diff(x, 3) + f(x).diff(x, 2) - 6*f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*exp(-3*x) + C3*exp(2*x))], + 'slow': True, + }, + + 'reducible_06': { + 'eq': f(x).diff(x, 4) - f(x).diff(x, 3) - 4*f(x).diff(x, 2) + \ + 4*f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*exp(-2*x) + C3*exp(x) + C4*exp(2*x))], + 'slow': True, + }, + + 'reducible_07': { + 'eq': f(x).diff(x, 4) + 3*f(x).diff(x, 3), + 'sol': [Eq(f(x), C1 + C2*x + C3*x**2 + C4*exp(-3*x))], + 'slow': True, + }, + + 'reducible_08': { + 'eq': f(x).diff(x, 4) - 2*f(x).diff(x, 2), + 'sol': [Eq(f(x), C1 + C2*x + C3*exp(-sqrt(2)*x) + C4*exp(sqrt(2)*x))], + 'slow': True, + }, + + 'reducible_09': { + 'eq': f(x).diff(x, 4) + 4*f(x).diff(x, 2), + 'sol': [Eq(f(x), C1 + C2*x + C3*sin(2*x) + C4*cos(2*x))], + 'slow': True, + }, + + 'reducible_10': { + 'eq': f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*x*sin(x) + C2*cos(x) - C3*x*cos(x) + C3*sin(x) + C4*sin(x) + C5*cos(x))], + 'slow': True, + }, + + 'reducible_11': { + 'eq': f(x).diff(x, 2) - f(x).diff(x)**3, + 'sol': [Eq(f(x), C1 - sqrt(2)*sqrt(-1/(C2 + x))*(C2 + x)), + Eq(f(x), C1 + sqrt(2)*sqrt(-1/(C2 + x))*(C2 + x))], + 'slow': True, + }, + + # Needs to be a way to know how to combine derivatives in the expression + 'reducible_12': { + 'eq': Derivative(x*f(x), x, x, x) + Derivative(f(x), x, x, x), + 'sol': [Eq(f(x), C1 + C3/Mul(2, (x**2 + 2*x + 1), evaluate=False) + + x*(C2 + C3/Mul(2, (x**2 + 2*x + 1), evaluate=False)))], # 2-arg Mul! + 'slow': True, + }, + } + } + + + +@_add_example_keys +def _get_examples_ode_sol_nth_linear_undetermined_coefficients(): + # examples 3-27 below are from Ordinary Differential Equations, + # Tenenbaum and Pollard, pg. 231 + g = exp(-x) + f2 = f(x).diff(x, 2) + c = 3*f(x).diff(x, 3) + 5*f2 + f(x).diff(x) - f(x) - x + t = symbols("t") + u = symbols("u",cls=Function) + R, L, C, E_0, alpha = symbols("R L C E_0 alpha",positive=True) + omega = Symbol('omega') + return { + 'hint': "nth_linear_constant_coeff_undetermined_coefficients", + 'func': f(x), + 'examples':{ + 'undet_01': { + 'eq': c - x*g, + 'sol': [Eq(f(x), C3*exp(x/3) - x + (C1 + x*(C2 - x**2/24 - 3*x/32))*exp(-x) - 1)], + 'slow': True, + }, + + 'undet_02': { + 'eq': c - g, + 'sol': [Eq(f(x), C3*exp(x/3) - x + (C1 + x*(C2 - x/8))*exp(-x) - 1)], + 'slow': True, + }, + + 'undet_03': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - 4, + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + 2)], + 'slow': True, + }, + + 'undet_04': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - 12*exp(x), + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + 2*exp(x))], + 'slow': True, + }, + + 'undet_05': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - exp(I*x), + 'sol': [Eq(f(x), (S(3)/10 + I/10)*(C1*exp(-2*x) + C2*exp(-x) - I*exp(I*x)))], + 'slow': True, + }, + + 'undet_06': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - sin(x), + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + sin(x)/10 - 3*cos(x)/10)], + 'slow': True, + }, + + 'undet_07': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - cos(x), + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + 3*sin(x)/10 + cos(x)/10)], + 'slow': True, + }, + + 'undet_08': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - (8 + 6*exp(x) + 2*sin(x)), + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + exp(x) + sin(x)/5 - 3*cos(x)/5 + 4)], + 'slow': True, + }, + + 'undet_09': { + 'eq': f2 + f(x).diff(x) + f(x) - x**2, + 'sol': [Eq(f(x), -2*x + x**2 + (C1*sin(x*sqrt(3)/2) + C2*cos(x*sqrt(3)/2))*exp(-x/2))], + 'slow': True, + }, + + 'undet_10': { + 'eq': f2 - 2*f(x).diff(x) - 8*f(x) - 9*x*exp(x) - 10*exp(-x), + 'sol': [Eq(f(x), -x*exp(x) - 2*exp(-x) + C1*exp(-2*x) + C2*exp(4*x))], + 'slow': True, + }, + + 'undet_11': { + 'eq': f2 - 3*f(x).diff(x) - 2*exp(2*x)*sin(x), + 'sol': [Eq(f(x), C1 + C2*exp(3*x) - 3*exp(2*x)*sin(x)/5 - exp(2*x)*cos(x)/5)], + 'slow': True, + }, + + 'undet_12': { + 'eq': f(x).diff(x, 4) - 2*f2 + f(x) - x + sin(x), + 'sol': [Eq(f(x), x - sin(x)/4 + (C1 + C2*x)*exp(-x) + (C3 + C4*x)*exp(x))], + 'slow': True, + }, + + 'undet_13': { + 'eq': f2 + f(x).diff(x) - x**2 - 2*x, + 'sol': [Eq(f(x), C1 + x**3/3 + C2*exp(-x))], + 'slow': True, + }, + + 'undet_14': { + 'eq': f2 + f(x).diff(x) - x - sin(2*x), + 'sol': [Eq(f(x), C1 - x - sin(2*x)/5 - cos(2*x)/10 + x**2/2 + C2*exp(-x))], + 'slow': True, + }, + + 'undet_15': { + 'eq': f2 + f(x) - 4*x*sin(x), + 'sol': [Eq(f(x), (C1 - x**2)*cos(x) + (C2 + x)*sin(x))], + 'slow': True, + }, + + 'undet_16': { + 'eq': f2 + 4*f(x) - x*sin(2*x), + 'sol': [Eq(f(x), (C1 - x**2/8)*cos(2*x) + (C2 + x/16)*sin(2*x))], + 'slow': True, + }, + + 'undet_17': { + 'eq': f2 + 2*f(x).diff(x) + f(x) - x**2*exp(-x), + 'sol': [Eq(f(x), (C1 + x*(C2 + x**3/12))*exp(-x))], + 'slow': True, + }, + + 'undet_18': { + 'eq': f(x).diff(x, 3) + 3*f2 + 3*f(x).diff(x) + f(x) - 2*exp(-x) + \ + x**2*exp(-x), + 'sol': [Eq(f(x), (C1 + x*(C2 + x*(C3 - x**3/60 + x/3)))*exp(-x))], + 'slow': True, + }, + + 'undet_19': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - exp(-2*x) - x**2, + 'sol': [Eq(f(x), C2*exp(-x) + x**2/2 - x*Rational(3,2) + (C1 - x)*exp(-2*x) + Rational(7,4))], + 'slow': True, + }, + + 'undet_20': { + 'eq': f2 - 3*f(x).diff(x) + 2*f(x) - x*exp(-x), + 'sol': [Eq(f(x), C1*exp(x) + C2*exp(2*x) + (6*x + 5)*exp(-x)/36)], + 'slow': True, + }, + + 'undet_21': { + 'eq': f2 + f(x).diff(x) - 6*f(x) - x - exp(2*x), + 'sol': [Eq(f(x), Rational(-1, 36) - x/6 + C2*exp(-3*x) + (C1 + x/5)*exp(2*x))], + 'slow': True, + }, + + 'undet_22': { + 'eq': f2 + f(x) - sin(x) - exp(-x), + 'sol': [Eq(f(x), C2*sin(x) + (C1 - x/2)*cos(x) + exp(-x)/2)], + 'slow': True, + }, + + 'undet_23': { + 'eq': f(x).diff(x, 3) - 3*f2 + 3*f(x).diff(x) - f(x) - exp(x), + 'sol': [Eq(f(x), (C1 + x*(C2 + x*(C3 + x/6)))*exp(x))], + 'slow': True, + }, + + 'undet_24': { + 'eq': f2 + f(x) - S.Half - cos(2*x)/2, + 'sol': [Eq(f(x), S.Half - cos(2*x)/6 + C1*sin(x) + C2*cos(x))], + 'slow': True, + }, + + 'undet_25': { + 'eq': f(x).diff(x, 3) - f(x).diff(x) - exp(2*x)*(S.Half - cos(2*x)/2), + 'sol': [Eq(f(x), C1 + C2*exp(-x) + C3*exp(x) + (-21*sin(2*x) + 27*cos(2*x) + 130)*exp(2*x)/1560)], + 'slow': True, + }, + + #Note: 'undet_26' is referred in 'undet_37' + 'undet_26': { + 'eq': (f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x) - 2*x - + sin(x) - cos(x)), + 'sol': [Eq(f(x), C1 + x**2 + (C2 + x*(C3 - x/8))*sin(x) + (C4 + x*(C5 + x/8))*cos(x))], + 'slow': True, + }, + + 'undet_27': { + 'eq': f2 + f(x) - cos(x)/2 + cos(3*x)/2, + 'sol': [Eq(f(x), cos(3*x)/16 + C2*cos(x) + (C1 + x/4)*sin(x))], + 'slow': True, + }, + + 'undet_28': { + 'eq': f(x).diff(x) - 1, + 'sol': [Eq(f(x), C1 + x)], + 'slow': True, + }, + + # https://github.com/sympy/sympy/issues/19358 + 'undet_29': { + 'eq': f2 + f(x).diff(x) + exp(x-C1), + 'sol': [Eq(f(x), C2 + C3*exp(-x) - exp(-C1 + x)/2)], + 'slow': True, + }, + + # https://github.com/sympy/sympy/issues/18408 + 'undet_30': { + 'eq': f(x).diff(x, 3) - f(x).diff(x) - sinh(x), + 'sol': [Eq(f(x), C1 + C2*exp(-x) + C3*exp(x) + x*sinh(x)/2)], + }, + + 'undet_31': { + 'eq': f(x).diff(x, 2) - 49*f(x) - sinh(3*x), + 'sol': [Eq(f(x), C1*exp(-7*x) + C2*exp(7*x) - sinh(3*x)/40)], + }, + + 'undet_32': { + 'eq': f(x).diff(x, 3) - f(x).diff(x) - sinh(x) - exp(x), + 'sol': [Eq(f(x), C1 + C3*exp(-x) + x*sinh(x)/2 + (C2 + x/2)*exp(x))], + }, + + # https://github.com/sympy/sympy/issues/5096 + 'undet_33': { + 'eq': f(x).diff(x, x) + f(x) - x*sin(x - 2), + 'sol': [Eq(f(x), C1*sin(x) + C2*cos(x) - x**2*cos(x - 2)/4 + x*sin(x - 2)/4)], + }, + + 'undet_34': { + 'eq': f(x).diff(x, 2) + f(x) - x**4*sin(x-1), + 'sol': [ Eq(f(x), C1*sin(x) + C2*cos(x) - x**5*cos(x - 1)/10 + x**4*sin(x - 1)/4 + x**3*cos(x - 1)/2 - 3*x**2*sin(x - 1)/4 - 3*x*cos(x - 1)/4)], + }, + + 'undet_35': { + 'eq': f(x).diff(x, 2) - f(x) - exp(x - 1), + 'sol': [Eq(f(x), C2*exp(-x) + (C1 + x*exp(-1)/2)*exp(x))], + }, + + 'undet_36': { + 'eq': f(x).diff(x, 2)+f(x)-(sin(x-2)+1), + 'sol': [Eq(f(x), C1*sin(x) + C2*cos(x) - x*cos(x - 2)/2 + 1)], + }, + + # Equivalent to example_name 'undet_26'. + # This previously failed because the algorithm for undetermined coefficients + # didn't know to multiply exp(I*x) by sufficient x because it is linearly + # dependent on sin(x) and cos(x). + 'undet_37': { + 'eq': f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x) - 2*x - exp(I*x), + 'sol': [Eq(f(x), C1 + x**2*(I*exp(I*x)/8 + 1) + (C2 + C3*x)*sin(x) + (C4 + C5*x)*cos(x))], + }, + + # https://github.com/sympy/sympy/issues/12623 + 'undet_38': { + 'eq': Eq( u(t).diff(t,t) + R /L*u(t).diff(t) + 1/(L*C)*u(t), alpha), + 'sol': [Eq(u(t), C*L*alpha + C2*exp(-t*(R + sqrt(C*R**2 - 4*L)/sqrt(C))/(2*L)) + + C1*exp(t*(-R + sqrt(C*R**2 - 4*L)/sqrt(C))/(2*L)))], + 'func': u(t) + }, + + 'undet_39': { + 'eq': Eq( L*C*u(t).diff(t,t) + R*C*u(t).diff(t) + u(t), E_0*exp(I*omega*t) ), + 'sol': [Eq(u(t), C2*exp(-t*(R + sqrt(C*R**2 - 4*L)/sqrt(C))/(2*L)) + + C1*exp(t*(-R + sqrt(C*R**2 - 4*L)/sqrt(C))/(2*L)) + - E_0*exp(I*omega*t)/(C*L*omega**2 - I*C*R*omega - 1))], + 'func': u(t), + }, + + # https://github.com/sympy/sympy/issues/6879 + 'undet_40': { + 'eq': Eq(Derivative(f(x), x, 2) - 2*Derivative(f(x), x) + f(x), sin(x)), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(x) + cos(x)/2)], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_separable(): + # test_separable1-5 are from Ordinary Differential Equations, Tenenbaum and + # Pollard, pg. 55 + t,a = symbols('a,t') + m = 96 + g = 9.8 + k = .2 + f1 = g * m + v = Function('v') + return { + 'hint': "separable", + 'func': f(x), + 'examples':{ + 'separable_01': { + 'eq': f(x).diff(x) - f(x), + 'sol': [Eq(f(x), C1*exp(x))], + }, + + 'separable_02': { + 'eq': x*f(x).diff(x) - f(x), + 'sol': [Eq(f(x), C1*x)], + }, + + 'separable_03': { + 'eq': f(x).diff(x) + sin(x), + 'sol': [Eq(f(x), C1 + cos(x))], + }, + + 'separable_04': { + 'eq': f(x)**2 + 1 - (x**2 + 1)*f(x).diff(x), + 'sol': [Eq(f(x), tan(C1 + atan(x)))], + }, + + 'separable_05': { + 'eq': f(x).diff(x)/tan(x) - f(x) - 2, + 'sol': [Eq(f(x), C1/cos(x) - 2)], + }, + + 'separable_06': { + 'eq': f(x).diff(x) * (1 - sin(f(x))) - 1, + 'sol': [Eq(-x + f(x) + cos(f(x)), C1)], + }, + + 'separable_07': { + 'eq': f(x)*x**2*f(x).diff(x) - f(x)**3 - 2*x**2*f(x).diff(x), + 'sol': [Eq(f(x), (-x - sqrt(x*(4*C1*x + x - 4)))/(C1*x - 1)/2), + Eq(f(x), (-x + sqrt(x*(4*C1*x + x - 4)))/(C1*x - 1)/2)], + 'slow': True, + }, + + 'separable_08': { + 'eq': f(x)**2 - 1 - (2*f(x) + x*f(x))*f(x).diff(x), + 'sol': [Eq(f(x), -sqrt(C1*x**2 + 4*C1*x + 4*C1 + 1)), + Eq(f(x), sqrt(C1*x**2 + 4*C1*x + 4*C1 + 1))], + 'slow': True, + }, + + 'separable_09': { + 'eq': x*log(x)*f(x).diff(x) + sqrt(1 + f(x)**2), + 'sol': [Eq(f(x), sinh(C1 - log(log(x))))], #One more solution is f(x)=I + 'slow': True, + 'checkodesol_XFAIL': True, + }, + + 'separable_10': { + 'eq': exp(x + 1)*tan(f(x)) + cos(f(x))*f(x).diff(x), + 'sol': [Eq(E*exp(x) + log(cos(f(x)) - 1)/2 - log(cos(f(x)) + 1)/2 + cos(f(x)), C1)], + 'slow': True, + }, + + 'separable_11': { + 'eq': (x*cos(f(x)) + x**2*sin(f(x))*f(x).diff(x) - a**2*sin(f(x))*f(x).diff(x)), + 'sol': [ + Eq(f(x), -acos(C1*sqrt(-a**2 + x**2)) + 2*pi), + Eq(f(x), acos(C1*sqrt(-a**2 + x**2))) + ], + 'slow': True, + }, + + 'separable_12': { + 'eq': f(x).diff(x) - f(x)*tan(x), + 'sol': [Eq(f(x), C1/cos(x))], + }, + + 'separable_13': { + 'eq': (x - 1)*cos(f(x))*f(x).diff(x) - 2*x*sin(f(x)), + 'sol': [ + Eq(f(x), pi - asin(C1*(x**2 - 2*x + 1)*exp(2*x))), + Eq(f(x), asin(C1*(x**2 - 2*x + 1)*exp(2*x))) + ], + }, + + 'separable_14': { + 'eq': f(x).diff(x) - f(x)*log(f(x))/tan(x), + 'sol': [Eq(f(x), exp(C1*sin(x)))], + }, + + 'separable_15': { + 'eq': x*f(x).diff(x) + (1 + f(x)**2)*atan(f(x)), + 'sol': [Eq(f(x), tan(C1/x))], #Two more solutions are f(x)=0 and f(x)=I + 'slow': True, + 'checkodesol_XFAIL': True, + }, + + 'separable_16': { + 'eq': f(x).diff(x) + x*(f(x) + 1), + 'sol': [Eq(f(x), -1 + C1*exp(-x**2/2))], + }, + + 'separable_17': { + 'eq': exp(f(x)**2)*(x**2 + 2*x + 1) + (x*f(x) + f(x))*f(x).diff(x), + 'sol': [ + Eq(f(x), -sqrt(log(1/(C1 + x**2 + 2*x)))), + Eq(f(x), sqrt(log(1/(C1 + x**2 + 2*x)))) + ], + }, + + 'separable_18': { + 'eq': f(x).diff(x) + f(x), + 'sol': [Eq(f(x), C1*exp(-x))], + }, + + 'separable_19': { + 'eq': sin(x)*cos(2*f(x)) + cos(x)*sin(2*f(x))*f(x).diff(x), + 'sol': [Eq(f(x), pi - acos(C1/cos(x)**2)/2), Eq(f(x), acos(C1/cos(x)**2)/2)], + }, + + 'separable_20': { + 'eq': (1 - x)*f(x).diff(x) - x*(f(x) + 1), + 'sol': [Eq(f(x), (C1*exp(-x) - x + 1)/(x - 1))], + }, + + 'separable_21': { + 'eq': f(x)*diff(f(x), x) + x - 3*x*f(x)**2, + 'sol': [Eq(f(x), -sqrt(3)*sqrt(C1*exp(3*x**2) + 1)/3), + Eq(f(x), sqrt(3)*sqrt(C1*exp(3*x**2) + 1)/3)], + }, + + 'separable_22': { + 'eq': f(x).diff(x) - exp(x + f(x)), + 'sol': [Eq(f(x), log(-1/(C1 + exp(x))))], + 'XFAIL': ['lie_group'] #It shows 'NoneType' object is not subscriptable for lie_group. + }, + + # https://github.com/sympy/sympy/issues/7081 + 'separable_23': { + 'eq': x*(f(x).diff(x)) + 1 - f(x)**2, + 'sol': [Eq(f(x), (-C1 - x**2)/(-C1 + x**2))], + }, + + # https://github.com/sympy/sympy/issues/10379 + 'separable_24': { + 'eq': f(t).diff(t)-(1-51.05*y*f(t)), + 'sol': [Eq(f(t), (0.019588638589618023*exp(y*(C1 - 51.049999999999997*t)) + 0.019588638589618023)/y)], + 'func': f(t), + }, + + # https://github.com/sympy/sympy/issues/15999 + 'separable_25': { + 'eq': f(x).diff(x) - C1*f(x), + 'sol': [Eq(f(x), C2*exp(C1*x))], + }, + + 'separable_26': { + 'eq': f1 - k * (v(t) ** 2) - m * Derivative(v(t)), + 'sol': [Eq(v(t), -68.585712797928991/tanh(C1 - 0.14288690166235204*t))], + 'func': v(t), + 'checkodesol_XFAIL': True, + }, + + #https://github.com/sympy/sympy/issues/22155 + 'separable_27': { + 'eq': f(x).diff(x) - exp(f(x) - x), + 'sol': [Eq(f(x), log(-exp(x)/(C1*exp(x) - 1)))], + } + } + } + + +@_add_example_keys +def _get_examples_ode_sol_1st_exact(): + # Type: Exact differential equation, p(x,f) + q(x,f)*f' == 0, + # where dp/df == dq/dx + ''' + Example 7 is an exact equation that fails under the exact engine. It is caught + by first order homogeneous albeit with a much contorted solution. The + exact engine fails because of a poorly simplified integral of q(0,y)dy, + where q is the function multiplying f'. The solutions should be + Eq(sqrt(x**2+f(x)**2)**3+y**3, C1). The equation below is + equivalent, but it is so complex that checkodesol fails, and takes a long + time to do so. + ''' + return { + 'hint': "1st_exact", + 'func': f(x), + 'examples':{ + '1st_exact_01': { + 'eq': sin(x)*cos(f(x)) + cos(x)*sin(f(x))*f(x).diff(x), + 'sol': [Eq(f(x), -acos(C1/cos(x)) + 2*pi), Eq(f(x), acos(C1/cos(x)))], + 'slow': True, + }, + + '1st_exact_02': { + 'eq': (2*x*f(x) + 1)/f(x) + (f(x) - x)/f(x)**2*f(x).diff(x), + 'sol': [Eq(f(x), exp(C1 - x**2 + LambertW(-x*exp(-C1 + x**2))))], + 'XFAIL': ['lie_group'], #It shows dsolve raises an exception: List index out of range for lie_group + 'slow': True, + 'checkodesol_XFAIL':True + }, + + '1st_exact_03': { + 'eq': 2*x + f(x)*cos(x) + (2*f(x) + sin(x) - sin(f(x)))*f(x).diff(x), + 'sol': [Eq(f(x)*sin(x) + cos(f(x)) + x**2 + f(x)**2, C1)], + 'XFAIL': ['lie_group'], #It goes into infinite loop for lie_group. + 'slow': True, + }, + + '1st_exact_04': { + 'eq': cos(f(x)) - (x*sin(f(x)) - f(x)**2)*f(x).diff(x), + 'sol': [Eq(x*cos(f(x)) + f(x)**3/3, C1)], + 'slow': True, + }, + + '1st_exact_05': { + 'eq': 2*x*f(x) + (x**2 + f(x)**2)*f(x).diff(x), + 'sol': [Eq(x**2*f(x) + f(x)**3/3, C1)], + 'slow': True, + 'simplify_flag':False + }, + + # This was from issue: https://github.com/sympy/sympy/issues/11290 + '1st_exact_06': { + 'eq': cos(f(x)) - (x*sin(f(x)) - f(x)**2)*f(x).diff(x), + 'sol': [Eq(x*cos(f(x)) + f(x)**3/3, C1)], + 'simplify_flag':False + }, + + '1st_exact_07': { + 'eq': x*sqrt(x**2 + f(x)**2) - (x**2*f(x)/(f(x) - sqrt(x**2 + f(x)**2)))*f(x).diff(x), + 'sol': [Eq(log(x), + C1 - 9*sqrt(1 + f(x)**2/x**2)*asinh(f(x)/x)/(-27*f(x)/x + + 27*sqrt(1 + f(x)**2/x**2)) - 9*sqrt(1 + f(x)**2/x**2)* + log(1 - sqrt(1 + f(x)**2/x**2)*f(x)/x + 2*f(x)**2/x**2)/ + (-27*f(x)/x + 27*sqrt(1 + f(x)**2/x**2)) + + 9*asinh(f(x)/x)*f(x)/(x*(-27*f(x)/x + 27*sqrt(1 + f(x)**2/x**2))) + + 9*f(x)*log(1 - sqrt(1 + f(x)**2/x**2)*f(x)/x + 2*f(x)**2/x**2)/ + (x*(-27*f(x)/x + 27*sqrt(1 + f(x)**2/x**2))))], + 'slow': True, + 'dsolve_too_slow':True + }, + + # Type: a(x)f'(x)+b(x)*f(x)+c(x)=0 + '1st_exact_08': { + 'eq': Eq(x**2*f(x).diff(x) + 3*x*f(x) - sin(x)/x, 0), + 'sol': [Eq(f(x), (C1 - cos(x))/x**3)], + }, + + # these examples are from test_exact_enhancement + '1st_exact_09': { + 'eq': f(x)/x**2 + ((f(x)*x - 1)/x)*f(x).diff(x), + 'sol': [Eq(f(x), (i*sqrt(C1*x**2 + 1) + 1)/x) for i in (-1, 1)], + }, + + '1st_exact_10': { + 'eq': (x*f(x) - 1) + f(x).diff(x)*(x**2 - x*f(x)), + 'sol': [Eq(f(x), x - sqrt(C1 + x**2 - 2*log(x))), Eq(f(x), x + sqrt(C1 + x**2 - 2*log(x)))], + }, + + '1st_exact_11': { + 'eq': (x + 2)*sin(f(x)) + f(x).diff(x)*x*cos(f(x)), + 'sol': [Eq(f(x), -asin(C1*exp(-x)/x**2) + pi), Eq(f(x), asin(C1*exp(-x)/x**2))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_nth_linear_var_of_parameters(): + g = exp(-x) + f2 = f(x).diff(x, 2) + c = 3*f(x).diff(x, 3) + 5*f2 + f(x).diff(x) - f(x) - x + return { + 'hint': "nth_linear_constant_coeff_variation_of_parameters", + 'func': f(x), + 'examples':{ + 'var_of_parameters_01': { + 'eq': c - x*g, + 'sol': [Eq(f(x), C3*exp(x/3) - x + (C1 + x*(C2 - x**2/24 - 3*x/32))*exp(-x) - 1)], + 'slow': True, + }, + + 'var_of_parameters_02': { + 'eq': c - g, + 'sol': [Eq(f(x), C3*exp(x/3) - x + (C1 + x*(C2 - x/8))*exp(-x) - 1)], + 'slow': True, + }, + + 'var_of_parameters_03': { + 'eq': f(x).diff(x) - 1, + 'sol': [Eq(f(x), C1 + x)], + 'slow': True, + }, + + 'var_of_parameters_04': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - 4, + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + 2)], + 'slow': True, + }, + + 'var_of_parameters_05': { + 'eq': f2 + 3*f(x).diff(x) + 2*f(x) - 12*exp(x), + 'sol': [Eq(f(x), C1*exp(-2*x) + C2*exp(-x) + 2*exp(x))], + 'slow': True, + }, + + 'var_of_parameters_06': { + 'eq': f2 - 2*f(x).diff(x) - 8*f(x) - 9*x*exp(x) - 10*exp(-x), + 'sol': [Eq(f(x), -x*exp(x) - 2*exp(-x) + C1*exp(-2*x) + C2*exp(4*x))], + 'slow': True, + }, + + 'var_of_parameters_07': { + 'eq': f2 + 2*f(x).diff(x) + f(x) - x**2*exp(-x), + 'sol': [Eq(f(x), (C1 + x*(C2 + x**3/12))*exp(-x))], + 'slow': True, + }, + + 'var_of_parameters_08': { + 'eq': f2 - 3*f(x).diff(x) + 2*f(x) - x*exp(-x), + 'sol': [Eq(f(x), C1*exp(x) + C2*exp(2*x) + (6*x + 5)*exp(-x)/36)], + 'slow': True, + }, + + 'var_of_parameters_09': { + 'eq': f(x).diff(x, 3) - 3*f2 + 3*f(x).diff(x) - f(x) - exp(x), + 'sol': [Eq(f(x), (C1 + x*(C2 + x*(C3 + x/6)))*exp(x))], + 'slow': True, + }, + + 'var_of_parameters_10': { + 'eq': f2 + 2*f(x).diff(x) + f(x) - exp(-x)/x, + 'sol': [Eq(f(x), (C1 + x*(C2 + log(x)))*exp(-x))], + 'slow': True, + }, + + 'var_of_parameters_11': { + 'eq': f2 + f(x) - 1/sin(x)*1/cos(x), + 'sol': [Eq(f(x), (C1 + log(sin(x) - 1)/2 - log(sin(x) + 1)/2 + )*cos(x) + (C2 + log(cos(x) - 1)/2 - log(cos(x) + 1)/2)*sin(x))], + 'slow': True, + }, + + 'var_of_parameters_12': { + 'eq': f(x).diff(x, 4) - 1/x, + 'sol': [Eq(f(x), C1 + C2*x + C3*x**2 + x**3*(C4 + log(x)/6))], + 'slow': True, + }, + + # These were from issue: https://github.com/sympy/sympy/issues/15996 + 'var_of_parameters_13': { + 'eq': f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x) - 2*x - exp(I*x), + 'sol': [Eq(f(x), C1 + x**2 + (C2 + x*(C3 - x/8 + 3*exp(I*x)/2 + 3*exp(-I*x)/2) + 5*exp(2*I*x)/16 + 2*I*exp(I*x) - 2*I*exp(-I*x))*sin(x) + (C4 + x*(C5 + I*x/8 + 3*I*exp(I*x)/2 - 3*I*exp(-I*x)/2) + + 5*I*exp(2*I*x)/16 - 2*exp(I*x) - 2*exp(-I*x))*cos(x) - I*exp(I*x))], + }, + + 'var_of_parameters_14': { + 'eq': f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x) - exp(I*x), + 'sol': [Eq(f(x), C1 + (C2 + x*(C3 - x/8) + 5*exp(2*I*x)/16)*sin(x) + (C4 + x*(C5 + I*x/8) + 5*I*exp(2*I*x)/16)*cos(x) - I*exp(I*x))], + }, + + # https://github.com/sympy/sympy/issues/14395 + 'var_of_parameters_15': { + 'eq': Derivative(f(x), x, x) + 9*f(x) - sec(x), + 'sol': [Eq(f(x), (C1 - x/3 + sin(2*x)/3)*sin(3*x) + (C2 + log(cos(x)) + - 2*log(cos(x)**2)/3 + 2*cos(x)**2/3)*cos(3*x))], + 'slow': True, + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_2nd_linear_bessel(): + return { + 'hint': "2nd_linear_bessel", + 'func': f(x), + 'examples':{ + '2nd_lin_bessel_01': { + 'eq': x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (x**2 - 4)*f(x), + 'sol': [Eq(f(x), C1*besselj(2, x) + C2*bessely(2, x))], + }, + + '2nd_lin_bessel_02': { + 'eq': x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (x**2 +25)*f(x), + 'sol': [Eq(f(x), C1*besselj(5*I, x) + C2*bessely(5*I, x))], + }, + + '2nd_lin_bessel_03': { + 'eq': x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (x**2)*f(x), + 'sol': [Eq(f(x), C1*besselj(0, x) + C2*bessely(0, x))], + }, + + '2nd_lin_bessel_04': { + 'eq': x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (81*x**2 -S(1)/9)*f(x), + 'sol': [Eq(f(x), C1*besselj(S(1)/3, 9*x) + C2*bessely(S(1)/3, 9*x))], + }, + + '2nd_lin_bessel_05': { + 'eq': x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (x**4 - 4)*f(x), + 'sol': [Eq(f(x), C1*besselj(1, x**2/2) + C2*bessely(1, x**2/2))], + }, + + '2nd_lin_bessel_06': { + 'eq': x**2*(f(x).diff(x, 2)) + 2*x*(f(x).diff(x)) + (x**4 - 4)*f(x), + 'sol': [Eq(f(x), (C1*besselj(sqrt(17)/4, x**2/2) + C2*bessely(sqrt(17)/4, x**2/2))/sqrt(x))], + }, + + '2nd_lin_bessel_07': { + 'eq': x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (x**2 - S(1)/4)*f(x), + 'sol': [Eq(f(x), C1*besselj(S(1)/2, x) + C2*bessely(S(1)/2, x))], + }, + + '2nd_lin_bessel_08': { + 'eq': x**2*(f(x).diff(x, 2)) - 3*x*(f(x).diff(x)) + (4*x + 4)*f(x), + 'sol': [Eq(f(x), x**2*(C1*besselj(0, 4*sqrt(x)) + C2*bessely(0, 4*sqrt(x))))], + }, + + '2nd_lin_bessel_09': { + 'eq': x*(f(x).diff(x, 2)) - f(x).diff(x) + 4*x**3*f(x), + 'sol': [Eq(f(x), x*(C1*besselj(S(1)/2, x**2) + C2*bessely(S(1)/2, x**2)))], + }, + + '2nd_lin_bessel_10': { + 'eq': (x-2)**2*(f(x).diff(x, 2)) - (x-2)*f(x).diff(x) + 4*(x-2)**2*f(x), + 'sol': [Eq(f(x), (x - 2)*(C1*besselj(1, 2*x - 4) + C2*bessely(1, 2*x - 4)))], + }, + + # https://github.com/sympy/sympy/issues/4414 + '2nd_lin_bessel_11': { + 'eq': f(x).diff(x, x) + 2/x*f(x).diff(x) + f(x), + 'sol': [Eq(f(x), (C1*besselj(S(1)/2, x) + C2*bessely(S(1)/2, x))/sqrt(x))], + }, + '2nd_lin_bessel_12': { + 'eq': x**2*f(x).diff(x, 2) + x*f(x).diff(x) + (a**2*x**2/c**2 - b**2)*f(x), + 'sol': [Eq(f(x), C1*besselj(sqrt(b**2), x*sqrt(a**2/c**2)) + C2*bessely(sqrt(b**2), x*sqrt(a**2/c**2)))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_2nd_2F1_hypergeometric(): + return { + 'hint': "2nd_hypergeometric", + 'func': f(x), + 'examples':{ + '2nd_2F1_hyper_01': { + 'eq': x*(x-1)*f(x).diff(x, 2) + (S(3)/2 -2*x)*f(x).diff(x) + 2*f(x), + 'sol': [Eq(f(x), C1*x**(S(5)/2)*hyper((S(3)/2, S(1)/2), (S(7)/2,), x) + C2*hyper((-1, -2), (-S(3)/2,), x))], + }, + + '2nd_2F1_hyper_02': { + 'eq': x*(x-1)*f(x).diff(x, 2) + (S(7)/2*x)*f(x).diff(x) + f(x), + 'sol': [Eq(f(x), (C1*(1 - x)**(S(5)/2)*hyper((S(1)/2, 2), (S(7)/2,), 1 - x) + + C2*hyper((-S(1)/2, -2), (-S(3)/2,), 1 - x))/(x - 1)**(S(5)/2))], + }, + + '2nd_2F1_hyper_03': { + 'eq': x*(x-1)*f(x).diff(x, 2) + (S(3)+ S(7)/2*x)*f(x).diff(x) + f(x), + 'sol': [Eq(f(x), (C1*(1 - x)**(S(11)/2)*hyper((S(1)/2, 2), (S(13)/2,), 1 - x) + + C2*hyper((-S(7)/2, -5), (-S(9)/2,), 1 - x))/(x - 1)**(S(11)/2))], + }, + + '2nd_2F1_hyper_04': { + 'eq': -x**(S(5)/7)*(-416*x**(S(9)/7)/9 - 2385*x**(S(5)/7)/49 + S(298)*x/3)*f(x)/(196*(-x**(S(6)/7) + + x)**2*(x**(S(6)/7) + x)**2) + Derivative(f(x), (x, 2)), + 'sol': [Eq(f(x), x**(S(45)/98)*(C1*x**(S(4)/49)*hyper((S(1)/3, -S(1)/2), (S(9)/7,), x**(S(2)/7)) + + C2*hyper((S(1)/21, -S(11)/14), (S(5)/7,), x**(S(2)/7)))/(x**(S(2)/7) - 1)**(S(19)/84))], + 'checkodesol_XFAIL':True, + }, + } + } + +@_add_example_keys +def _get_examples_ode_sol_2nd_nonlinear_autonomous_conserved(): + return { + 'hint': "2nd_nonlinear_autonomous_conserved", + 'func': f(x), + 'examples': { + '2nd_nonlinear_autonomous_conserved_01': { + 'eq': f(x).diff(x, 2) + exp(f(x)) + log(f(x)), + 'sol': [ + Eq(Integral(1/sqrt(C1 - 2*_u*log(_u) + 2*_u - 2*exp(_u)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(C1 - 2*_u*log(_u) + 2*_u - 2*exp(_u)), (_u, f(x))), C2 - x) + ], + 'simplify_flag': False, + }, + '2nd_nonlinear_autonomous_conserved_02': { + 'eq': f(x).diff(x, 2) + cbrt(f(x)) + 1/f(x), + 'sol': [ + Eq(sqrt(2)*Integral(1/sqrt(2*C1 - 3*_u**Rational(4, 3) - 4*log(_u)), (_u, f(x))), C2 + x), + Eq(sqrt(2)*Integral(1/sqrt(2*C1 - 3*_u**Rational(4, 3) - 4*log(_u)), (_u, f(x))), C2 - x) + ], + 'simplify_flag': False, + }, + '2nd_nonlinear_autonomous_conserved_03': { + 'eq': f(x).diff(x, 2) + sin(f(x)), + 'sol': [ + Eq(Integral(1/sqrt(C1 + 2*cos(_u)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(C1 + 2*cos(_u)), (_u, f(x))), C2 - x) + ], + 'simplify_flag': False, + }, + '2nd_nonlinear_autonomous_conserved_04': { + 'eq': f(x).diff(x, 2) + cosh(f(x)), + 'sol': [ + Eq(Integral(1/sqrt(C1 - 2*sinh(_u)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(C1 - 2*sinh(_u)), (_u, f(x))), C2 - x) + ], + 'simplify_flag': False, + }, + '2nd_nonlinear_autonomous_conserved_05': { + 'eq': f(x).diff(x, 2) + asin(f(x)), + 'sol': [ + Eq(Integral(1/sqrt(C1 - 2*_u*asin(_u) - 2*sqrt(1 - _u**2)), (_u, f(x))), C2 + x), + Eq(Integral(1/sqrt(C1 - 2*_u*asin(_u) - 2*sqrt(1 - _u**2)), (_u, f(x))), C2 - x) + ], + 'simplify_flag': False, + 'XFAIL': ['2nd_nonlinear_autonomous_conserved_Integral'] + } + } + } + + +@_add_example_keys +def _get_examples_ode_sol_separable_reduced(): + df = f(x).diff(x) + return { + 'hint': "separable_reduced", + 'func': f(x), + 'examples':{ + 'separable_reduced_01': { + 'eq': x* df + f(x)* (1 / (x**2*f(x) - 1)), + 'sol': [Eq(log(x**2*f(x))/3 + log(x**2*f(x) - Rational(3, 2))/6, C1 + log(x))], + 'simplify_flag': False, + 'XFAIL': ['lie_group'], #It hangs. + }, + + #Note: 'separable_reduced_02' is referred in 'separable_reduced_11' + 'separable_reduced_02': { + 'eq': f(x).diff(x) + (f(x) / (x**4*f(x) - x)), + 'sol': [Eq(log(x**3*f(x))/4 + log(x**3*f(x) - Rational(4,3))/12, C1 + log(x))], + 'simplify_flag': False, + 'checkodesol_XFAIL':True, #It hangs for this. + }, + + 'separable_reduced_03': { + 'eq': x*df + f(x)*(x**2*f(x)), + 'sol': [Eq(log(x**2*f(x))/2 - log(x**2*f(x) - 2)/2, C1 + log(x))], + 'simplify_flag': False, + }, + + 'separable_reduced_04': { + 'eq': Eq(f(x).diff(x) + f(x)/x * (1 + (x**(S(2)/3)*f(x))**2), 0), + 'sol': [Eq(-3*log(x**(S(2)/3)*f(x)) + 3*log(3*x**(S(4)/3)*f(x)**2 + 1)/2, C1 + log(x))], + 'simplify_flag': False, + }, + + 'separable_reduced_05': { + 'eq': Eq(f(x).diff(x) + f(x)/x * (1 + (x*f(x))**2), 0), + 'sol': [Eq(f(x), -sqrt(2)*sqrt(1/(C1 + log(x)))/(2*x)),\ + Eq(f(x), sqrt(2)*sqrt(1/(C1 + log(x)))/(2*x))], + }, + + 'separable_reduced_06': { + 'eq': Eq(f(x).diff(x) + (x**4*f(x)**2 + x**2*f(x))*f(x)/(x*(x**6*f(x)**3 + x**4*f(x)**2)), 0), + 'sol': [Eq(f(x), C1 + 1/(2*x**2))], + }, + + 'separable_reduced_07': { + 'eq': Eq(f(x).diff(x) + (f(x)**2)*f(x)/(x), 0), + 'sol': [ + Eq(f(x), -sqrt(2)*sqrt(1/(C1 + log(x)))/2), + Eq(f(x), sqrt(2)*sqrt(1/(C1 + log(x)))/2) + ], + }, + + 'separable_reduced_08': { + 'eq': Eq(f(x).diff(x) + (f(x)+3)*f(x)/(x*(f(x)+2)), 0), + 'sol': [Eq(-log(f(x) + 3)/3 - 2*log(f(x))/3, C1 + log(x))], + 'simplify_flag': False, + 'XFAIL': ['lie_group'], #It hangs. + }, + + 'separable_reduced_09': { + 'eq': Eq(f(x).diff(x) + (f(x)+3)*f(x)/x, 0), + 'sol': [Eq(f(x), 3/(C1*x**3 - 1))], + }, + + 'separable_reduced_10': { + 'eq': Eq(f(x).diff(x) + (f(x)**2+f(x))*f(x)/(x), 0), + 'sol': [Eq(- log(x) - log(f(x) + 1) + log(f(x)) + 1/f(x), C1)], + 'XFAIL': ['lie_group'],#No algorithms are implemented to solve equation -C1 + x*(_y + 1)*exp(-1/_y)/_y + + }, + + # Equivalent to example_name 'separable_reduced_02'. Only difference is testing with simplify=True + 'separable_reduced_11': { + 'eq': f(x).diff(x) + (f(x) / (x**4*f(x) - x)), + 'sol': [Eq(f(x), -sqrt(2)*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)/6 +- sqrt(2)*sqrt(-3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) ++ 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 4/x**6 +- 4*sqrt(2)/(x**9*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)))/6 + 1/(3*x**3)), +Eq(f(x), -sqrt(2)*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)/6 ++ sqrt(2)*sqrt(-3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) ++ 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 4/x**6 +- 4*sqrt(2)/(x**9*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)))/6 + 1/(3*x**3)), +Eq(f(x), sqrt(2)*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)/6 +- sqrt(2)*sqrt(-3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) ++ 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) ++ 4/x**6 + 4*sqrt(2)/(x**9*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)))/6 + 1/(3*x**3)), +Eq(f(x), sqrt(2)*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) +- 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)/6 ++ sqrt(2)*sqrt(-3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) ++ x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 4/x**6 + 4*sqrt(2)/(x**9*sqrt(3*3**Rational(1,3)*(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) +- exp(12*C1)/x**6)**Rational(1,3) - 3*3**Rational(2,3)*exp(12*C1)/(sqrt((3*exp(12*C1) + x**(-12))*exp(24*C1)) - exp(12*C1)/x**6)**Rational(1,3) + 2/x**6)))/6 + 1/(3*x**3))], + 'checkodesol_XFAIL':True, #It hangs for this. + 'slow': True, + }, + + #These were from issue: https://github.com/sympy/sympy/issues/6247 + 'separable_reduced_12': { + 'eq': x**2*f(x)**2 + x*Derivative(f(x), x), + 'sol': [Eq(f(x), 2*C1/(C1*x**2 - 1))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_lie_group(): + a, b, c = symbols("a b c") + return { + 'hint': "lie_group", + 'func': f(x), + 'examples':{ + #Example 1-4 and 19-20 were from issue: https://github.com/sympy/sympy/issues/17322 + 'lie_group_01': { + 'eq': x*f(x).diff(x)*(f(x)+4) + (f(x)**2) -2*f(x)-2*x, + 'sol': [], + 'dsolve_too_slow': True, + 'checkodesol_too_slow': True, + }, + + 'lie_group_02': { + 'eq': x*f(x).diff(x)*(f(x)+4) + (f(x)**2) -2*f(x)-2*x, + 'sol': [], + 'dsolve_too_slow': True, + }, + + 'lie_group_03': { + 'eq': Eq(x**7*Derivative(f(x), x) + 5*x**3*f(x)**2 - (2*x**2 + 2)*f(x)**3, 0), + 'sol': [], + 'dsolve_too_slow': True, + }, + + 'lie_group_04': { + 'eq': f(x).diff(x) - (f(x) - x*log(x))**2/x**2 + log(x), + 'sol': [], + 'XFAIL': ['lie_group'], + }, + + 'lie_group_05': { + 'eq': f(x).diff(x)**2, + 'sol': [Eq(f(x), C1)], + 'XFAIL': ['factorable'], #It raises Not Implemented error + }, + + 'lie_group_06': { + 'eq': Eq(f(x).diff(x), x**2*f(x)), + 'sol': [Eq(f(x), C1*exp(x**3)**Rational(1, 3))], + }, + + 'lie_group_07': { + 'eq': f(x).diff(x) + a*f(x) - c*exp(b*x), + 'sol': [Eq(f(x), Piecewise(((-C1*(a + b) + c*exp(x*(a + b)))*exp(-a*x)/(a + b),\ + Ne(a, -b)), ((-C1 + c*x)*exp(-a*x), True)))], + }, + + 'lie_group_08': { + 'eq': f(x).diff(x) + 2*x*f(x) - x*exp(-x**2), + 'sol': [Eq(f(x), (C1 + x**2/2)*exp(-x**2))], + }, + + 'lie_group_09': { + 'eq': (1 + 2*x)*(f(x).diff(x)) + 2 - 4*exp(-f(x)), + 'sol': [Eq(f(x), log(C1/(2*x + 1) + 2))], + }, + + 'lie_group_10': { + 'eq': x**2*(f(x).diff(x)) - f(x) + x**2*exp(x - (1/x)), + 'sol': [Eq(f(x), (C1 - exp(x))*exp(-1/x))], + 'XFAIL': ['factorable'], #It raises Recursion Error (maixmum depth exceeded) + }, + + 'lie_group_11': { + 'eq': x**2*f(x)**2 + x*Derivative(f(x), x), + 'sol': [Eq(f(x), 2/(C1 + x**2))], + }, + + 'lie_group_12': { + 'eq': diff(f(x),x) + 2*x*f(x) - x*exp(-x**2), + 'sol': [Eq(f(x), exp(-x**2)*(C1 + x**2/2))], + }, + + 'lie_group_13': { + 'eq': diff(f(x),x) + f(x)*cos(x) - exp(2*x), + 'sol': [Eq(f(x), exp(-sin(x))*(C1 + Integral(exp(2*x)*exp(sin(x)), x)))], + }, + + 'lie_group_14': { + 'eq': diff(f(x),x) + f(x)*cos(x) - sin(2*x)/2, + 'sol': [Eq(f(x), C1*exp(-sin(x)) + sin(x) - 1)], + }, + + 'lie_group_15': { + 'eq': x*diff(f(x),x) + f(x) - x*sin(x), + 'sol': [Eq(f(x), (C1 - x*cos(x) + sin(x))/x)], + }, + + 'lie_group_16': { + 'eq': x*diff(f(x),x) - f(x) - x/log(x), + 'sol': [Eq(f(x), x*(C1 + log(log(x))))], + }, + + 'lie_group_17': { + 'eq': (f(x).diff(x)-f(x)) * (f(x).diff(x)+f(x)), + 'sol': [Eq(f(x), C1*exp(x)), Eq(f(x), C1*exp(-x))], + }, + + 'lie_group_18': { + 'eq': f(x).diff(x) * (f(x).diff(x) - f(x)), + 'sol': [Eq(f(x), C1*exp(x)), Eq(f(x), C1)], + }, + + 'lie_group_19': { + 'eq': (f(x).diff(x)-f(x)) * (f(x).diff(x)+f(x)), + 'sol': [Eq(f(x), C1*exp(-x)), Eq(f(x), C1*exp(x))], + }, + + 'lie_group_20': { + 'eq': f(x).diff(x)*(f(x).diff(x)+f(x)), + 'sol': [Eq(f(x), C1), Eq(f(x), C1*exp(-x))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_2nd_linear_airy(): + return { + 'hint': "2nd_linear_airy", + 'func': f(x), + 'examples':{ + '2nd_lin_airy_01': { + 'eq': f(x).diff(x, 2) - x*f(x), + 'sol': [Eq(f(x), C1*airyai(x) + C2*airybi(x))], + }, + + '2nd_lin_airy_02': { + 'eq': f(x).diff(x, 2) + 2*x*f(x), + 'sol': [Eq(f(x), C1*airyai(-2**(S(1)/3)*x) + C2*airybi(-2**(S(1)/3)*x))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_nth_linear_constant_coeff_homogeneous(): + # From Exercise 20, in Ordinary Differential Equations, + # Tenenbaum and Pollard, pg. 220 + a = Symbol('a', positive=True) + k = Symbol('k', real=True) + r1, r2, r3, r4, r5 = [rootof(x**5 + 11*x - 2, n) for n in range(5)] + r6, r7, r8, r9, r10 = [rootof(x**5 - 3*x + 1, n) for n in range(5)] + r11, r12, r13, r14, r15 = [rootof(x**5 - 100*x**3 + 1000*x + 1, n) for n in range(5)] + r16, r17, r18, r19, r20 = [rootof(x**5 - x**4 + 10, n) for n in range(5)] + r21, r22, r23, r24, r25 = [rootof(x**5 - x + 1, n) for n in range(5)] + E = exp(1) + return { + 'hint': "nth_linear_constant_coeff_homogeneous", + 'func': f(x), + 'examples':{ + 'lin_const_coeff_hom_01': { + 'eq': f(x).diff(x, 2) + 2*f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*exp(-2*x))], + }, + + 'lin_const_coeff_hom_02': { + 'eq': f(x).diff(x, 2) - 3*f(x).diff(x) + 2*f(x), + 'sol': [Eq(f(x), (C1 + C2*exp(x))*exp(x))], + }, + + 'lin_const_coeff_hom_03': { + 'eq': f(x).diff(x, 2) - f(x), + 'sol': [Eq(f(x), C1*exp(-x) + C2*exp(x))], + }, + + 'lin_const_coeff_hom_04': { + 'eq': f(x).diff(x, 3) + f(x).diff(x, 2) - 6*f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*exp(-3*x) + C3*exp(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_05': { + 'eq': 6*f(x).diff(x, 2) - 11*f(x).diff(x) + 4*f(x), + 'sol': [Eq(f(x), C1*exp(x/2) + C2*exp(x*Rational(4, 3)))], + 'slow': True, + }, + + 'lin_const_coeff_hom_06': { + 'eq': Eq(f(x).diff(x, 2) + 2*f(x).diff(x) - f(x), 0), + 'sol': [Eq(f(x), C1*exp(x*(-1 + sqrt(2))) + C2*exp(-x*(sqrt(2) + 1)))], + 'slow': True, + }, + + 'lin_const_coeff_hom_07': { + 'eq': diff(f(x), x, 3) + diff(f(x), x, 2) - 10*diff(f(x), x) - 6*f(x), + 'sol': [Eq(f(x), C1*exp(3*x) + C3*exp(-x*(2 + sqrt(2))) + C2*exp(x*(-2 + sqrt(2))))], + 'slow': True, + }, + + 'lin_const_coeff_hom_08': { + 'eq': f(x).diff(x, 4) - f(x).diff(x, 3) - 4*f(x).diff(x, 2) + \ + 4*f(x).diff(x), + 'sol': [Eq(f(x), C1 + C2*exp(-2*x) + C3*exp(x) + C4*exp(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_09': { + 'eq': f(x).diff(x, 4) + 4*f(x).diff(x, 3) + f(x).diff(x, 2) - \ + 4*f(x).diff(x) - 2*f(x), + 'sol': [Eq(f(x), C3*exp(-x) + C4*exp(x) + (C1*exp(-sqrt(2)*x) + C2*exp(sqrt(2)*x))*exp(-2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_10': { + 'eq': f(x).diff(x, 4) - a**2*f(x), + 'sol': [Eq(f(x), C1*exp(-sqrt(a)*x) + C2*exp(sqrt(a)*x) + C3*sin(sqrt(a)*x) + C4*cos(sqrt(a)*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_11': { + 'eq': f(x).diff(x, 2) - 2*k*f(x).diff(x) - 2*f(x), + 'sol': [Eq(f(x), C1*exp(x*(k - sqrt(k**2 + 2))) + C2*exp(x*(k + sqrt(k**2 + 2))))], + 'slow': True, + }, + + 'lin_const_coeff_hom_12': { + 'eq': f(x).diff(x, 2) + 4*k*f(x).diff(x) - 12*k**2*f(x), + 'sol': [Eq(f(x), C1*exp(-6*k*x) + C2*exp(2*k*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_13': { + 'eq': f(x).diff(x, 4), + 'sol': [Eq(f(x), C1 + C2*x + C3*x**2 + C4*x**3)], + 'slow': True, + }, + + 'lin_const_coeff_hom_14': { + 'eq': f(x).diff(x, 2) + 4*f(x).diff(x) + 4*f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(-2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_15': { + 'eq': 3*f(x).diff(x, 3) + 5*f(x).diff(x, 2) + f(x).diff(x) - f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(-x) + C3*exp(x/3))], + 'slow': True, + }, + + 'lin_const_coeff_hom_16': { + 'eq': f(x).diff(x, 3) - 6*f(x).diff(x, 2) + 12*f(x).diff(x) - 8*f(x), + 'sol': [Eq(f(x), (C1 + x*(C2 + C3*x))*exp(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_17': { + 'eq': f(x).diff(x, 2) - 2*a*f(x).diff(x) + a**2*f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(a*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_18': { + 'eq': f(x).diff(x, 4) + 3*f(x).diff(x, 3), + 'sol': [Eq(f(x), C1 + C2*x + C3*x**2 + C4*exp(-3*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_19': { + 'eq': f(x).diff(x, 4) - 2*f(x).diff(x, 2), + 'sol': [Eq(f(x), C1 + C2*x + C3*exp(-sqrt(2)*x) + C4*exp(sqrt(2)*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_20': { + 'eq': f(x).diff(x, 4) + 2*f(x).diff(x, 3) - 11*f(x).diff(x, 2) - \ + 12*f(x).diff(x) + 36*f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(-3*x) + (C3 + C4*x)*exp(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_21': { + 'eq': 36*f(x).diff(x, 4) - 37*f(x).diff(x, 2) + 4*f(x).diff(x) + 5*f(x), + 'sol': [Eq(f(x), C1*exp(-x) + C2*exp(-x/3) + C3*exp(x/2) + C4*exp(x*Rational(5, 6)))], + 'slow': True, + }, + + 'lin_const_coeff_hom_22': { + 'eq': f(x).diff(x, 4) - 8*f(x).diff(x, 2) + 16*f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(-2*x) + (C3 + C4*x)*exp(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_23': { + 'eq': f(x).diff(x, 2) - 2*f(x).diff(x) + 5*f(x), + 'sol': [Eq(f(x), (C1*sin(2*x) + C2*cos(2*x))*exp(x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_24': { + 'eq': f(x).diff(x, 2) - f(x).diff(x) + f(x), + 'sol': [Eq(f(x), (C1*sin(x*sqrt(3)/2) + C2*cos(x*sqrt(3)/2))*exp(x/2))], + 'slow': True, + }, + + 'lin_const_coeff_hom_25': { + 'eq': f(x).diff(x, 4) + 5*f(x).diff(x, 2) + 6*f(x), + 'sol': [Eq(f(x), + C1*sin(sqrt(2)*x) + C2*sin(sqrt(3)*x) + C3*cos(sqrt(2)*x) + C4*cos(sqrt(3)*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_26': { + 'eq': f(x).diff(x, 2) - 4*f(x).diff(x) + 20*f(x), + 'sol': [Eq(f(x), (C1*sin(4*x) + C2*cos(4*x))*exp(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_27': { + 'eq': f(x).diff(x, 4) + 4*f(x).diff(x, 2) + 4*f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*sin(x*sqrt(2)) + (C3 + C4*x)*cos(x*sqrt(2)))], + 'slow': True, + }, + + 'lin_const_coeff_hom_28': { + 'eq': f(x).diff(x, 3) + 8*f(x), + 'sol': [Eq(f(x), (C1*sin(x*sqrt(3)) + C2*cos(x*sqrt(3)))*exp(x) + C3*exp(-2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_29': { + 'eq': f(x).diff(x, 4) + 4*f(x).diff(x, 2), + 'sol': [Eq(f(x), C1 + C2*x + C3*sin(2*x) + C4*cos(2*x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_30': { + 'eq': f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x), + 'sol': [Eq(f(x), C1 + (C2 + C3*x)*sin(x) + (C4 + C5*x)*cos(x))], + 'slow': True, + }, + + 'lin_const_coeff_hom_31': { + 'eq': f(x).diff(x, 4) + f(x).diff(x, 2) + f(x), + 'sol': [Eq(f(x), (C1*sin(sqrt(3)*x/2) + C2*cos(sqrt(3)*x/2))*exp(-x/2) + + (C3*sin(sqrt(3)*x/2) + C4*cos(sqrt(3)*x/2))*exp(x/2))], + 'slow': True, + }, + + 'lin_const_coeff_hom_32': { + 'eq': f(x).diff(x, 4) + 4*f(x).diff(x, 2) + f(x), + 'sol': [Eq(f(x), C1*sin(x*sqrt(-sqrt(3) + 2)) + C2*sin(x*sqrt(sqrt(3) + 2)) + + C3*cos(x*sqrt(-sqrt(3) + 2)) + C4*cos(x*sqrt(sqrt(3) + 2)))], + 'slow': True, + }, + + # One real root, two complex conjugate pairs + 'lin_const_coeff_hom_33': { + 'eq': f(x).diff(x, 5) + 11*f(x).diff(x) - 2*f(x), + 'sol': [Eq(f(x), + C5*exp(r1*x) + exp(re(r2)*x) * (C1*sin(im(r2)*x) + C2*cos(im(r2)*x)) + + exp(re(r4)*x) * (C3*sin(im(r4)*x) + C4*cos(im(r4)*x)))], + 'checkodesol_XFAIL':True, #It Hangs + }, + + # Three real roots, one complex conjugate pair + 'lin_const_coeff_hom_34': { + 'eq': f(x).diff(x,5) - 3*f(x).diff(x) + f(x), + 'sol': [Eq(f(x), + C3*exp(r6*x) + C4*exp(r7*x) + C5*exp(r8*x) + + exp(re(r9)*x) * (C1*sin(im(r9)*x) + C2*cos(im(r9)*x)))], + 'checkodesol_XFAIL':True, #It Hangs + }, + + # Five distinct real roots + 'lin_const_coeff_hom_35': { + 'eq': f(x).diff(x,5) - 100*f(x).diff(x,3) + 1000*f(x).diff(x) + f(x), + 'sol': [Eq(f(x), C1*exp(r11*x) + C2*exp(r12*x) + C3*exp(r13*x) + C4*exp(r14*x) + C5*exp(r15*x))], + 'checkodesol_XFAIL':True, #It Hangs + }, + + # Rational root and unsolvable quintic + 'lin_const_coeff_hom_36': { + 'eq': f(x).diff(x, 6) - 6*f(x).diff(x, 5) + 5*f(x).diff(x, 4) + 10*f(x).diff(x) - 50 * f(x), + 'sol': [Eq(f(x), + C5*exp(5*x) + + C6*exp(x*r16) + + exp(re(r17)*x) * (C1*sin(im(r17)*x) + C2*cos(im(r17)*x)) + + exp(re(r19)*x) * (C3*sin(im(r19)*x) + C4*cos(im(r19)*x)))], + 'checkodesol_XFAIL':True, #It Hangs + }, + + # Five double roots (this is (x**5 - x + 1)**2) + 'lin_const_coeff_hom_37': { + 'eq': f(x).diff(x, 10) - 2*f(x).diff(x, 6) + 2*f(x).diff(x, 5) + + f(x).diff(x, 2) - 2*f(x).diff(x, 1) + f(x), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(x*r21) + (-((C3 + C4*x)*sin(x*im(r22))) + + (C5 + C6*x)*cos(x*im(r22)))*exp(x*re(r22)) + (-((C7 + C8*x)*sin(x*im(r24))) + + (C10*x + C9)*cos(x*im(r24)))*exp(x*re(r24)))], + 'checkodesol_XFAIL':True, #It Hangs + }, + + 'lin_const_coeff_hom_38': { + 'eq': Eq(sqrt(2) * f(x).diff(x,x,x) + f(x).diff(x), 0), + 'sol': [Eq(f(x), C1 + C2*sin(2**Rational(3, 4)*x/2) + C3*cos(2**Rational(3, 4)*x/2))], + }, + + 'lin_const_coeff_hom_39': { + 'eq': Eq(E * f(x).diff(x,x,x) + f(x).diff(x), 0), + 'sol': [Eq(f(x), C1 + C2*sin(x/sqrt(E)) + C3*cos(x/sqrt(E)))], + }, + + 'lin_const_coeff_hom_40': { + 'eq': Eq(pi * f(x).diff(x,x,x) + f(x).diff(x), 0), + 'sol': [Eq(f(x), C1 + C2*sin(x/sqrt(pi)) + C3*cos(x/sqrt(pi)))], + }, + + 'lin_const_coeff_hom_41': { + 'eq': Eq(I * f(x).diff(x,x,x) + f(x).diff(x), 0), + 'sol': [Eq(f(x), C1 + C2*exp(-sqrt(I)*x) + C3*exp(sqrt(I)*x))], + }, + + 'lin_const_coeff_hom_42': { + 'eq': f(x).diff(x, x) + y*f(x), + 'sol': [Eq(f(x), C1*exp(-x*sqrt(-y)) + C2*exp(x*sqrt(-y)))], + }, + + 'lin_const_coeff_hom_43': { + 'eq': Eq(9*f(x).diff(x, x) + f(x), 0), + 'sol': [Eq(f(x), C1*sin(x/3) + C2*cos(x/3))], + }, + + 'lin_const_coeff_hom_44': { + 'eq': Eq(9*f(x).diff(x, x), f(x)), + 'sol': [Eq(f(x), C1*exp(-x/3) + C2*exp(x/3))], + }, + + 'lin_const_coeff_hom_45': { + 'eq': Eq(f(x).diff(x, x) - 3*diff(f(x), x) + 2*f(x), 0), + 'sol': [Eq(f(x), (C1 + C2*exp(x))*exp(x))], + }, + + 'lin_const_coeff_hom_46': { + 'eq': Eq(f(x).diff(x, x) - 4*diff(f(x), x) + 4*f(x), 0), + 'sol': [Eq(f(x), (C1 + C2*x)*exp(2*x))], + }, + + # Type: 2nd order, constant coefficients (two real equal roots) + 'lin_const_coeff_hom_47': { + 'eq': Eq(f(x).diff(x, x) + 2*diff(f(x), x) + 3*f(x), 0), + 'sol': [Eq(f(x), (C1*sin(x*sqrt(2)) + C2*cos(x*sqrt(2)))*exp(-x))], + }, + + #These were from issue: https://github.com/sympy/sympy/issues/6247 + 'lin_const_coeff_hom_48': { + 'eq': f(x).diff(x, x) + 4*f(x), + 'sol': [Eq(f(x), C1*sin(2*x) + C2*cos(2*x))], + }, + } + } + + +@_add_example_keys +def _get_examples_ode_sol_1st_homogeneous_coeff_subs_dep_div_indep(): + return { + 'hint': "1st_homogeneous_coeff_subs_dep_div_indep", + 'func': f(x), + 'examples':{ + 'dep_div_indep_01': { + 'eq': f(x)/x*cos(f(x)/x) - (x/f(x)*sin(f(x)/x) + cos(f(x)/x))*f(x).diff(x), + 'sol': [Eq(log(x), C1 - log(f(x)*sin(f(x)/x)/x))], + 'slow': True + }, + + #indep_div_dep actually has a simpler solution for example 2 but it runs too slow. + 'dep_div_indep_02': { + 'eq': x*f(x).diff(x) - f(x) - x*sin(f(x)/x), + 'sol': [Eq(log(x), log(C1) + log(cos(f(x)/x) - 1)/2 - log(cos(f(x)/x) + 1)/2)], + 'simplify_flag':False, + }, + + 'dep_div_indep_03': { + 'eq': x*exp(f(x)/x) - f(x)*sin(f(x)/x) + x*sin(f(x)/x)*f(x).diff(x), + 'sol': [Eq(log(x), C1 + exp(-f(x)/x)*sin(f(x)/x)/2 + exp(-f(x)/x)*cos(f(x)/x)/2)], + 'slow': True + }, + + 'dep_div_indep_04': { + 'eq': f(x).diff(x) - f(x)/x + 1/sin(f(x)/x), + 'sol': [Eq(f(x), x*(-acos(C1 + log(x)) + 2*pi)), Eq(f(x), x*acos(C1 + log(x)))], + 'slow': True + }, + + # previous code was testing with these other solution: + # example5_solb = Eq(f(x), log(log(C1/x)**(-x))) + 'dep_div_indep_05': { + 'eq': x*exp(f(x)/x) + f(x) - x*f(x).diff(x), + 'sol': [Eq(f(x), log((1/(C1 - log(x)))**x))], + 'checkodesol_XFAIL':True, #(because of **x?) + }, + } + } + +@_add_example_keys +def _get_examples_ode_sol_linear_coefficients(): + return { + 'hint': "linear_coefficients", + 'func': f(x), + 'examples':{ + 'linear_coeff_01': { + 'eq': f(x).diff(x) + (3 + 2*f(x))/(x + 3), + 'sol': [Eq(f(x), C1/(x**2 + 6*x + 9) - Rational(3, 2))], + }, + } + } + +@_add_example_keys +def _get_examples_ode_sol_1st_homogeneous_coeff_best(): + return { + 'hint': "1st_homogeneous_coeff_best", + 'func': f(x), + 'examples':{ + # previous code was testing this with other solution: + # example1_solb = Eq(-f(x)/(1 + log(x/f(x))), C1) + '1st_homogeneous_coeff_best_01': { + 'eq': f(x) + (x*log(f(x)/x) - 2*x)*diff(f(x), x), + 'sol': [Eq(f(x), -exp(C1)*LambertW(-x*exp(-C1 + 1)))], + 'checkodesol_XFAIL':True, #(because of LambertW?) + }, + + '1st_homogeneous_coeff_best_02': { + 'eq': 2*f(x)*exp(x/f(x)) + f(x)*f(x).diff(x) - 2*x*exp(x/f(x))*f(x).diff(x), + 'sol': [Eq(log(f(x)), C1 - 2*exp(x/f(x)))], + }, + + # previous code was testing this with other solution: + # example3_solb = Eq(log(C1*x*sqrt(1/x)*sqrt(f(x))) + x**2/(2*f(x)**2), 0) + '1st_homogeneous_coeff_best_03': { + 'eq': 2*x**2*f(x) + f(x)**3 + (x*f(x)**2 - 2*x**3)*f(x).diff(x), + 'sol': [Eq(f(x), exp(2*C1 + LambertW(-2*x**4*exp(-4*C1))/2)/x)], + 'checkodesol_XFAIL':True, #(because of LambertW?) + }, + + '1st_homogeneous_coeff_best_04': { + 'eq': (x + sqrt(f(x)**2 - x*f(x)))*f(x).diff(x) - f(x), + 'sol': [Eq(log(f(x)), C1 - 2*sqrt(-x/f(x) + 1))], + 'slow': True, + }, + + '1st_homogeneous_coeff_best_05': { + 'eq': x + f(x) - (x - f(x))*f(x).diff(x), + 'sol': [Eq(log(x), C1 - log(sqrt(1 + f(x)**2/x**2)) + atan(f(x)/x))], + }, + + '1st_homogeneous_coeff_best_06': { + 'eq': x*f(x).diff(x) - f(x) - x*sin(f(x)/x), + 'sol': [Eq(f(x), 2*x*atan(C1*x))], + }, + + '1st_homogeneous_coeff_best_07': { + 'eq': x**2 + f(x)**2 - 2*x*f(x)*f(x).diff(x), + 'sol': [Eq(f(x), -sqrt(x*(C1 + x))), Eq(f(x), sqrt(x*(C1 + x)))], + }, + + '1st_homogeneous_coeff_best_08': { + 'eq': f(x)**2 + (x*sqrt(f(x)**2 - x**2) - x*f(x))*f(x).diff(x), + 'sol': [Eq(f(x), -C1*sqrt(-x/(x - 2*C1))), Eq(f(x), C1*sqrt(-x/(x - 2*C1)))], + 'checkodesol_XFAIL': True # solutions are valid in a range + }, + } + } + + +def _get_all_examples(): + all_examples = _get_examples_ode_sol_euler_homogeneous + \ + _get_examples_ode_sol_euler_undetermined_coeff + \ + _get_examples_ode_sol_euler_var_para + \ + _get_examples_ode_sol_factorable + \ + _get_examples_ode_sol_bernoulli + \ + _get_examples_ode_sol_nth_algebraic + \ + _get_examples_ode_sol_riccati + \ + _get_examples_ode_sol_1st_linear + \ + _get_examples_ode_sol_1st_exact + \ + _get_examples_ode_sol_almost_linear + \ + _get_examples_ode_sol_nth_order_reducible + \ + _get_examples_ode_sol_nth_linear_undetermined_coefficients + \ + _get_examples_ode_sol_liouville + \ + _get_examples_ode_sol_separable + \ + _get_examples_ode_sol_1st_rational_riccati + \ + _get_examples_ode_sol_nth_linear_var_of_parameters + \ + _get_examples_ode_sol_2nd_linear_bessel + \ + _get_examples_ode_sol_2nd_2F1_hypergeometric + \ + _get_examples_ode_sol_2nd_nonlinear_autonomous_conserved + \ + _get_examples_ode_sol_separable_reduced + \ + _get_examples_ode_sol_lie_group + \ + _get_examples_ode_sol_2nd_linear_airy + \ + _get_examples_ode_sol_nth_linear_constant_coeff_homogeneous +\ + _get_examples_ode_sol_1st_homogeneous_coeff_best +\ + _get_examples_ode_sol_1st_homogeneous_coeff_subs_dep_div_indep +\ + _get_examples_ode_sol_linear_coefficients + + return all_examples diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_subscheck.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_subscheck.py new file mode 100644 index 0000000000000000000000000000000000000000..799c2854e878208721b600767de350cda08cd7e5 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_subscheck.py @@ -0,0 +1,203 @@ +from sympy.core.function import (Derivative, Function, diff) +from sympy.core.numbers import (I, Rational, pi) +from sympy.core.relational import Eq +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.functions.special.error_functions import (Ei, erf, erfi) +from sympy.integrals.integrals import Integral + +from sympy.solvers.ode.subscheck import checkodesol, checksysodesol + +from sympy.functions import besselj, bessely + +from sympy.testing.pytest import raises, slow + + +C0, C1, C2, C3, C4 = symbols('C0:5') +u, x, y, z = symbols('u,x:z', real=True) +f = Function('f') +g = Function('g') +h = Function('h') + + +@slow +def test_checkodesol(): + # For the most part, checkodesol is well tested in the tests below. + # These tests only handle cases not checked below. + raises(ValueError, lambda: checkodesol(f(x, y).diff(x), Eq(f(x, y), x))) + raises(ValueError, lambda: checkodesol(f(x).diff(x), Eq(f(x, y), + x), f(x, y))) + assert checkodesol(f(x).diff(x), Eq(f(x, y), x)) == \ + (False, -f(x).diff(x) + f(x, y).diff(x) - 1) + assert checkodesol(f(x).diff(x), Eq(f(x), x)) is not True + assert checkodesol(f(x).diff(x), Eq(f(x), x)) == (False, 1) + sol1 = Eq(f(x)**5 + 11*f(x) - 2*f(x) + x, 0) + assert checkodesol(diff(sol1.lhs, x), sol1) == (True, 0) + assert checkodesol(diff(sol1.lhs, x)*exp(f(x)), sol1) == (True, 0) + assert checkodesol(diff(sol1.lhs, x, 2), sol1) == (True, 0) + assert checkodesol(diff(sol1.lhs, x, 2)*exp(f(x)), sol1) == (True, 0) + assert checkodesol(diff(sol1.lhs, x, 3), sol1) == (True, 0) + assert checkodesol(diff(sol1.lhs, x, 3)*exp(f(x)), sol1) == (True, 0) + assert checkodesol(diff(sol1.lhs, x, 3), Eq(f(x), x*log(x))) == \ + (False, 60*x**4*((log(x) + 1)**2 + log(x))*( + log(x) + 1)*log(x)**2 - 5*x**4*log(x)**4 - 9) + assert checkodesol(diff(exp(f(x)) + x, x)*x, Eq(exp(f(x)) + x, 0)) == \ + (True, 0) + assert checkodesol(diff(exp(f(x)) + x, x)*x, Eq(exp(f(x)) + x, 0), + solve_for_func=False) == (True, 0) + assert checkodesol(f(x).diff(x, 2), [Eq(f(x), C1 + C2*x), + Eq(f(x), C2 + C1*x), Eq(f(x), C1*x + C2*x**2)]) == \ + [(True, 0), (True, 0), (False, C2)] + assert checkodesol(f(x).diff(x, 2), {Eq(f(x), C1 + C2*x), + Eq(f(x), C2 + C1*x), Eq(f(x), C1*x + C2*x**2)}) == \ + {(True, 0), (True, 0), (False, C2)} + assert checkodesol(f(x).diff(x) - 1/f(x)/2, Eq(f(x)**2, x)) == \ + [(True, 0), (True, 0)] + assert checkodesol(f(x).diff(x) - f(x), Eq(C1*exp(x), f(x))) == (True, 0) + # Based on test_1st_homogeneous_coeff_ode2_eq3sol. Make sure that + # checkodesol tries back substituting f(x) when it can. + eq3 = x*exp(f(x)/x) + f(x) - x*f(x).diff(x) + sol3 = Eq(f(x), log(log(C1/x)**(-x))) + assert not checkodesol(eq3, sol3)[1].has(f(x)) + # This case was failing intermittently depending on hash-seed: + eqn = Eq(Derivative(x*Derivative(f(x), x), x)/x, exp(x)) + sol = Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x)) + assert checkodesol(eqn, sol, order=2, solve_for_func=False)[0] + eq = x**2*(f(x).diff(x, 2)) + x*(f(x).diff(x)) + (2*x**2 +25)*f(x) + sol = Eq(f(x), C1*besselj(5*I, sqrt(2)*x) + C2*bessely(5*I, sqrt(2)*x)) + assert checkodesol(eq, sol) == (True, 0) + + eqs = [Eq(f(x).diff(x), f(x) + g(x)), Eq(g(x).diff(x), f(x) + g(x))] + sol = [Eq(f(x), -C1 + C2*exp(2*x)), Eq(g(x), C1 + C2*exp(2*x))] + assert checkodesol(eqs, sol) == (True, [0, 0]) + + +def test_checksysodesol(): + x, y, z = symbols('x, y, z', cls=Function) + t = Symbol('t') + eq = (Eq(diff(x(t),t), 9*y(t)), Eq(diff(y(t),t), 12*x(t))) + sol = [Eq(x(t), 9*C1*exp(-6*sqrt(3)*t) + 9*C2*exp(6*sqrt(3)*t)), \ + Eq(y(t), -6*sqrt(3)*C1*exp(-6*sqrt(3)*t) + 6*sqrt(3)*C2*exp(6*sqrt(3)*t))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), 2*x(t) + 4*y(t)), Eq(diff(y(t),t), 12*x(t) + 41*y(t))) + sol = [Eq(x(t), 4*C1*exp(t*(-sqrt(1713)/2 + Rational(43, 2))) + 4*C2*exp(t*(sqrt(1713)/2 + \ + Rational(43, 2)))), Eq(y(t), C1*(-sqrt(1713)/2 + Rational(39, 2))*exp(t*(-sqrt(1713)/2 + \ + Rational(43, 2))) + C2*(Rational(39, 2) + sqrt(1713)/2)*exp(t*(sqrt(1713)/2 + Rational(43, 2))))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), x(t) + y(t)), Eq(diff(y(t),t), -2*x(t) + 2*y(t))) + sol = [Eq(x(t), (C1*sin(sqrt(7)*t/2) + C2*cos(sqrt(7)*t/2))*exp(t*Rational(3, 2))), \ + Eq(y(t), ((C1/2 - sqrt(7)*C2/2)*sin(sqrt(7)*t/2) + (sqrt(7)*C1/2 + \ + C2/2)*cos(sqrt(7)*t/2))*exp(t*Rational(3, 2)))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), x(t) + y(t) + 9), Eq(diff(y(t),t), 2*x(t) + 5*y(t) + 23)) + sol = [Eq(x(t), C1*exp(t*(-sqrt(6) + 3)) + C2*exp(t*(sqrt(6) + 3)) - \ + Rational(22, 3)), Eq(y(t), C1*(-sqrt(6) + 2)*exp(t*(-sqrt(6) + 3)) + C2*(2 + \ + sqrt(6))*exp(t*(sqrt(6) + 3)) - Rational(5, 3))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), x(t) + y(t) + 81), Eq(diff(y(t),t), -2*x(t) + y(t) + 23)) + sol = [Eq(x(t), (C1*sin(sqrt(2)*t) + C2*cos(sqrt(2)*t))*exp(t) - Rational(58, 3)), \ + Eq(y(t), (sqrt(2)*C1*cos(sqrt(2)*t) - sqrt(2)*C2*sin(sqrt(2)*t))*exp(t) - Rational(185, 3))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), 5*t*x(t) + 2*y(t)), Eq(diff(y(t),t), 2*x(t) + 5*t*y(t))) + sol = [Eq(x(t), (C1*exp(Integral(2, t).doit()) + C2*exp(-(Integral(2, t)).doit()))*\ + exp((Integral(5*t, t)).doit())), Eq(y(t), (C1*exp((Integral(2, t)).doit()) - \ + C2*exp(-(Integral(2, t)).doit()))*exp((Integral(5*t, t)).doit()))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), 5*t*x(t) + t**2*y(t)), Eq(diff(y(t),t), -t**2*x(t) + 5*t*y(t))) + sol = [Eq(x(t), (C1*cos((Integral(t**2, t)).doit()) + C2*sin((Integral(t**2, t)).doit()))*\ + exp((Integral(5*t, t)).doit())), Eq(y(t), (-C1*sin((Integral(t**2, t)).doit()) + \ + C2*cos((Integral(t**2, t)).doit()))*exp((Integral(5*t, t)).doit()))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), 5*t*x(t) + t**2*y(t)), Eq(diff(y(t),t), -t**2*x(t) + (5*t+9*t**2)*y(t))) + sol = [Eq(x(t), (C1*exp((-sqrt(77)/2 + Rational(9, 2))*(Integral(t**2, t)).doit()) + \ + C2*exp((sqrt(77)/2 + Rational(9, 2))*(Integral(t**2, t)).doit()))*exp((Integral(5*t, t)).doit())), \ + Eq(y(t), (C1*(-sqrt(77)/2 + Rational(9, 2))*exp((-sqrt(77)/2 + Rational(9, 2))*(Integral(t**2, t)).doit()) + \ + C2*(sqrt(77)/2 + Rational(9, 2))*exp((sqrt(77)/2 + Rational(9, 2))*(Integral(t**2, t)).doit()))*exp((Integral(5*t, t)).doit()))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t,t), 5*x(t) + 43*y(t)), Eq(diff(y(t),t,t), x(t) + 9*y(t))) + root0 = -sqrt(-sqrt(47) + 7) + root1 = sqrt(-sqrt(47) + 7) + root2 = -sqrt(sqrt(47) + 7) + root3 = sqrt(sqrt(47) + 7) + sol = [Eq(x(t), 43*C1*exp(t*root0) + 43*C2*exp(t*root1) + 43*C3*exp(t*root2) + 43*C4*exp(t*root3)), \ + Eq(y(t), C1*(root0**2 - 5)*exp(t*root0) + C2*(root1**2 - 5)*exp(t*root1) + \ + C3*(root2**2 - 5)*exp(t*root2) + C4*(root3**2 - 5)*exp(t*root3))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t,t), 8*x(t)+3*y(t)+31), Eq(diff(y(t),t,t), 9*x(t)+7*y(t)+12)) + root0 = -sqrt(-sqrt(109)/2 + Rational(15, 2)) + root1 = sqrt(-sqrt(109)/2 + Rational(15, 2)) + root2 = -sqrt(sqrt(109)/2 + Rational(15, 2)) + root3 = sqrt(sqrt(109)/2 + Rational(15, 2)) + sol = [Eq(x(t), 3*C1*exp(t*root0) + 3*C2*exp(t*root1) + 3*C3*exp(t*root2) + 3*C4*exp(t*root3) - Rational(181, 29)), \ + Eq(y(t), C1*(root0**2 - 8)*exp(t*root0) + C2*(root1**2 - 8)*exp(t*root1) + \ + C3*(root2**2 - 8)*exp(t*root2) + C4*(root3**2 - 8)*exp(t*root3) + Rational(183, 29))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t,t) - 9*diff(y(t),t) + 7*x(t),0), Eq(diff(y(t),t,t) + 9*diff(x(t),t) + 7*y(t),0)) + sol = [Eq(x(t), C1*cos(t*(Rational(9, 2) + sqrt(109)/2)) + C2*sin(t*(Rational(9, 2) + sqrt(109)/2)) + \ + C3*cos(t*(-sqrt(109)/2 + Rational(9, 2))) + C4*sin(t*(-sqrt(109)/2 + Rational(9, 2)))), Eq(y(t), -C1*sin(t*(Rational(9, 2) + sqrt(109)/2)) \ + + C2*cos(t*(Rational(9, 2) + sqrt(109)/2)) - C3*sin(t*(-sqrt(109)/2 + Rational(9, 2))) + C4*cos(t*(-sqrt(109)/2 + Rational(9, 2))))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t,t), 9*t*diff(y(t),t)-9*y(t)), Eq(diff(y(t),t,t),7*t*diff(x(t),t)-7*x(t))) + I1 = sqrt(6)*7**Rational(1, 4)*sqrt(pi)*erfi(sqrt(6)*7**Rational(1, 4)*t/2)/2 - exp(3*sqrt(7)*t**2/2)/t + I2 = -sqrt(6)*7**Rational(1, 4)*sqrt(pi)*erf(sqrt(6)*7**Rational(1, 4)*t/2)/2 - exp(-3*sqrt(7)*t**2/2)/t + sol = [Eq(x(t), C3*t + t*(9*C1*I1 + 9*C2*I2)), Eq(y(t), C4*t + t*(3*sqrt(7)*C1*I1 - 3*sqrt(7)*C2*I2))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), 21*x(t)), Eq(diff(y(t),t), 17*x(t)+3*y(t)), Eq(diff(z(t),t), 5*x(t)+7*y(t)+9*z(t))) + sol = [Eq(x(t), C1*exp(21*t)), Eq(y(t), 17*C1*exp(21*t)/18 + C2*exp(3*t)), \ + Eq(z(t), 209*C1*exp(21*t)/216 - 7*C2*exp(3*t)/6 + C3*exp(9*t))] + assert checksysodesol(eq, sol) == (True, [0, 0, 0]) + + eq = (Eq(diff(x(t),t),3*y(t)-11*z(t)),Eq(diff(y(t),t),7*z(t)-3*x(t)),Eq(diff(z(t),t),11*x(t)-7*y(t))) + sol = [Eq(x(t), 7*C0 + sqrt(179)*C1*cos(sqrt(179)*t) + (77*C1/3 + 130*C2/3)*sin(sqrt(179)*t)), \ + Eq(y(t), 11*C0 + sqrt(179)*C2*cos(sqrt(179)*t) + (-58*C1/3 - 77*C2/3)*sin(sqrt(179)*t)), \ + Eq(z(t), 3*C0 + sqrt(179)*(-7*C1/3 - 11*C2/3)*cos(sqrt(179)*t) + (11*C1 - 7*C2)*sin(sqrt(179)*t))] + assert checksysodesol(eq, sol) == (True, [0, 0, 0]) + + eq = (Eq(3*diff(x(t),t),4*5*(y(t)-z(t))),Eq(4*diff(y(t),t),3*5*(z(t)-x(t))),Eq(5*diff(z(t),t),3*4*(x(t)-y(t)))) + sol = [Eq(x(t), C0 + 5*sqrt(2)*C1*cos(5*sqrt(2)*t) + (12*C1/5 + 164*C2/15)*sin(5*sqrt(2)*t)), \ + Eq(y(t), C0 + 5*sqrt(2)*C2*cos(5*sqrt(2)*t) + (-51*C1/10 - 12*C2/5)*sin(5*sqrt(2)*t)), \ + Eq(z(t), C0 + 5*sqrt(2)*(-9*C1/25 - 16*C2/25)*cos(5*sqrt(2)*t) + (12*C1/5 - 12*C2/5)*sin(5*sqrt(2)*t))] + assert checksysodesol(eq, sol) == (True, [0, 0, 0]) + + eq = (Eq(diff(x(t),t),4*x(t) - z(t)),Eq(diff(y(t),t),2*x(t)+2*y(t)-z(t)),Eq(diff(z(t),t),3*x(t)+y(t))) + sol = [Eq(x(t), C1*exp(2*t) + C2*t*exp(2*t) + C2*exp(2*t) + C3*t**2*exp(2*t)/2 + C3*t*exp(2*t) + C3*exp(2*t)), \ + Eq(y(t), C1*exp(2*t) + C2*t*exp(2*t) + C2*exp(2*t) + C3*t**2*exp(2*t)/2 + C3*t*exp(2*t)), \ + Eq(z(t), 2*C1*exp(2*t) + 2*C2*t*exp(2*t) + C2*exp(2*t) + C3*t**2*exp(2*t) + C3*t*exp(2*t) + C3*exp(2*t))] + assert checksysodesol(eq, sol) == (True, [0, 0, 0]) + + eq = (Eq(diff(x(t),t),4*x(t) - y(t) - 2*z(t)),Eq(diff(y(t),t),2*x(t) + y(t)- 2*z(t)),Eq(diff(z(t),t),5*x(t)-3*z(t))) + sol = [Eq(x(t), C1*exp(2*t) + C2*(-sin(t) + 3*cos(t)) + C3*(3*sin(t) + cos(t))), \ + Eq(y(t), C2*(-sin(t) + 3*cos(t)) + C3*(3*sin(t) + cos(t))), Eq(z(t), C1*exp(2*t) + 5*C2*cos(t) + 5*C3*sin(t))] + assert checksysodesol(eq, sol) == (True, [0, 0, 0]) + + eq = (Eq(diff(x(t),t),x(t)*y(t)**3), Eq(diff(y(t),t),y(t)**5)) + sol = [Eq(x(t), C1*exp((-1/(4*C2 + 4*t))**(Rational(-1, 4)))), Eq(y(t), -(-1/(4*C2 + 4*t))**Rational(1, 4)), \ + Eq(x(t), C1*exp(-1/(-1/(4*C2 + 4*t))**Rational(1, 4))), Eq(y(t), (-1/(4*C2 + 4*t))**Rational(1, 4)), \ + Eq(x(t), C1*exp(-I/(-1/(4*C2 + 4*t))**Rational(1, 4))), Eq(y(t), -I*(-1/(4*C2 + 4*t))**Rational(1, 4)), \ + Eq(x(t), C1*exp(I/(-1/(4*C2 + 4*t))**Rational(1, 4))), Eq(y(t), I*(-1/(4*C2 + 4*t))**Rational(1, 4))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(diff(x(t),t), exp(3*x(t))*y(t)**3),Eq(diff(y(t),t), y(t)**5)) + sol = [Eq(x(t), -log(C1 - 3/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), Eq(y(t), -(-1/(4*C2 + 4*t))**Rational(1, 4)), \ + Eq(x(t), -log(C1 + 3/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), Eq(y(t), (-1/(4*C2 + 4*t))**Rational(1, 4)), \ + Eq(x(t), -log(C1 + 3*I/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), Eq(y(t), -I*(-1/(4*C2 + 4*t))**Rational(1, 4)), \ + Eq(x(t), -log(C1 - 3*I/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), Eq(y(t), I*(-1/(4*C2 + 4*t))**Rational(1, 4))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + eq = (Eq(x(t),t*diff(x(t),t)+diff(x(t),t)*diff(y(t),t)), Eq(y(t),t*diff(y(t),t)+diff(y(t),t)**2)) + sol = {Eq(x(t), C1*C2 + C1*t), Eq(y(t), C2**2 + C2*t)} + assert checksysodesol(eq, sol) == (True, [0, 0]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_systems.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_systems.py new file mode 100644 index 0000000000000000000000000000000000000000..9d206129dfcf38c7b8c2e0ab42bd875003253f35 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/ode/tests/test_systems.py @@ -0,0 +1,2544 @@ +from sympy.core.function import (Derivative, Function, diff) +from sympy.core.mul import Mul +from sympy.core.numbers import (I, Rational, pi) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.hyperbolic import sinh +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.matrices.dense import Matrix +from sympy.core.containers import Tuple +from sympy.functions import exp, cos, sin, log, Ci, Si, erf, erfi +from sympy.matrices import dotprodsimp, NonSquareMatrixError +from sympy.solvers.ode import dsolve +from sympy.solvers.ode.ode import constant_renumber +from sympy.solvers.ode.subscheck import checksysodesol +from sympy.solvers.ode.systems import (_classify_linear_system, linear_ode_to_matrix, + ODEOrderError, ODENonlinearError, _simpsol, + _is_commutative_anti_derivative, linodesolve, + canonical_odes, dsolve_system, _component_division, + _eqs2dict, _dict2graph) +from sympy.functions import airyai, airybi +from sympy.integrals.integrals import Integral +from sympy.simplify.ratsimp import ratsimp +from sympy.testing.pytest import raises, slow, tooslow, XFAIL + + +C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10 = symbols('C0:11') +x = symbols('x') +f = Function('f') +g = Function('g') +h = Function('h') + + +def test_linear_ode_to_matrix(): + f, g, h = symbols("f, g, h", cls=Function) + t = Symbol("t") + funcs = [f(t), g(t), h(t)] + f1 = f(t).diff(t) + g1 = g(t).diff(t) + h1 = h(t).diff(t) + f2 = f(t).diff(t, 2) + g2 = g(t).diff(t, 2) + h2 = h(t).diff(t, 2) + + eqs_1 = [Eq(f1, g(t)), Eq(g1, f(t))] + sol_1 = ([Matrix([[1, 0], [0, 1]]), Matrix([[ 0, 1], [1, 0]])], Matrix([[0],[0]])) + assert linear_ode_to_matrix(eqs_1, funcs[:-1], t, 1) == sol_1 + + eqs_2 = [Eq(f1, f(t) + 2*g(t)), Eq(g1, h(t)), Eq(h1, g(t) + h(t) + f(t))] + sol_2 = ([Matrix([[1, 0, 0], [0, 1, 0], [0, 0, 1]]), Matrix([[1, 2, 0], [ 0, 0, 1], [1, 1, 1]])], + Matrix([[0], [0], [0]])) + assert linear_ode_to_matrix(eqs_2, funcs, t, 1) == sol_2 + + eqs_3 = [Eq(2*f1 + 3*h1, f(t) + g(t)), Eq(4*h1 + 5*g1, f(t) + h(t)), Eq(5*f1 + 4*g1, g(t) + h(t))] + sol_3 = ([Matrix([[2, 0, 3], [0, 5, 4], [5, 4, 0]]), Matrix([[1, 1, 0], [1, 0, 1], [0, 1, 1]])], + Matrix([[0], [0], [0]])) + assert linear_ode_to_matrix(eqs_3, funcs, t, 1) == sol_3 + + eqs_4 = [Eq(f2 + h(t), f1 + g(t)), Eq(2*h2 + g2 + g1 + g(t), 0), Eq(3*h1, 4)] + sol_4 = ([Matrix([[1, 0, 0], [0, 1, 2], [0, 0, 0]]), Matrix([[1, 0, 0], [0, -1, 0], [0, 0, -3]]), + Matrix([[0, 1, -1], [0, -1, 0], [0, 0, 0]])], Matrix([[0], [0], [4]])) + assert linear_ode_to_matrix(eqs_4, funcs, t, 2) == sol_4 + + eqs_5 = [Eq(f2, g(t)), Eq(f1 + g1, f(t))] + raises(ODEOrderError, lambda: linear_ode_to_matrix(eqs_5, funcs[:-1], t, 1)) + + eqs_6 = [Eq(f1, f(t)**2), Eq(g1, f(t) + g(t))] + raises(ODENonlinearError, lambda: linear_ode_to_matrix(eqs_6, funcs[:-1], t, 1)) + + +def test__classify_linear_system(): + x, y, z, w = symbols('x, y, z, w', cls=Function) + t, k, l = symbols('t k l') + x1 = diff(x(t), t) + y1 = diff(y(t), t) + z1 = diff(z(t), t) + w1 = diff(w(t), t) + x2 = diff(x(t), t, t) + y2 = diff(y(t), t, t) + funcs = [x(t), y(t)] + funcs_2 = funcs + [z(t), w(t)] + + eqs_1 = (5 * x1 + 12 * x(t) - 6 * (y(t)), (2 * y1 - 11 * t * x(t) + 3 * y(t) + t)) + assert _classify_linear_system(eqs_1, funcs, t) is None + + eqs_2 = (5 * (x1**2) + 12 * x(t) - 6 * (y(t)), (2 * y1 - 11 * t * x(t) + 3 * y(t) + t)) + sol2 = {'is_implicit': True, + 'canon_eqs': [[Eq(Derivative(x(t), t), -sqrt(-12*x(t)/5 + 6*y(t)/5)), + Eq(Derivative(y(t), t), 11*t*x(t)/2 - t/2 - 3*y(t)/2)], + [Eq(Derivative(x(t), t), sqrt(-12*x(t)/5 + 6*y(t)/5)), + Eq(Derivative(y(t), t), 11*t*x(t)/2 - t/2 - 3*y(t)/2)]]} + assert _classify_linear_system(eqs_2, funcs, t) == sol2 + + eqs_2_1 = [Eq(Derivative(x(t), t), -sqrt(-12*x(t)/5 + 6*y(t)/5)), + Eq(Derivative(y(t), t), 11*t*x(t)/2 - t/2 - 3*y(t)/2)] + assert _classify_linear_system(eqs_2_1, funcs, t) is None + + eqs_2_2 = [Eq(Derivative(x(t), t), sqrt(-12*x(t)/5 + 6*y(t)/5)), + Eq(Derivative(y(t), t), 11*t*x(t)/2 - t/2 - 3*y(t)/2)] + assert _classify_linear_system(eqs_2_2, funcs, t) is None + + eqs_3 = (5 * x1 + 12 * x(t) - 6 * (y(t)), (2 * y1 - 11 * x(t) + 3 * y(t)), (5 * w1 + z(t)), (z1 + w(t))) + answer_3 = {'no_of_equation': 4, + 'eq': (12*x(t) - 6*y(t) + 5*Derivative(x(t), t), + -11*x(t) + 3*y(t) + 2*Derivative(y(t), t), + z(t) + 5*Derivative(w(t), t), + w(t) + Derivative(z(t), t)), + 'func': [x(t), y(t), z(t), w(t)], + 'order': {x(t): 1, y(t): 1, z(t): 1, w(t): 1}, + 'is_linear': True, + 'is_constant': True, + 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [Rational(12, 5), Rational(-6, 5), 0, 0], + [Rational(-11, 2), Rational(3, 2), 0, 0], + [0, 0, 0, 1], + [0, 0, Rational(1, 5), 0]]), + 'type_of_equation': 'type1', + 'is_general': True} + assert _classify_linear_system(eqs_3, funcs_2, t) == answer_3 + + eqs_4 = (5 * x1 + 12 * x(t) - 6 * (y(t)), (2 * y1 - 11 * x(t) + 3 * y(t)), (z1 - w(t)), (w1 - z(t))) + answer_4 = {'no_of_equation': 4, + 'eq': (12 * x(t) - 6 * y(t) + 5 * Derivative(x(t), t), + -11 * x(t) + 3 * y(t) + 2 * Derivative(y(t), t), + -w(t) + Derivative(z(t), t), + -z(t) + Derivative(w(t), t)), + 'func': [x(t), y(t), z(t), w(t)], + 'order': {x(t): 1, y(t): 1, z(t): 1, w(t): 1}, + 'is_linear': True, + 'is_constant': True, + 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [Rational(12, 5), Rational(-6, 5), 0, 0], + [Rational(-11, 2), Rational(3, 2), 0, 0], + [0, 0, 0, -1], + [0, 0, -1, 0]]), + 'type_of_equation': 'type1', + 'is_general': True} + assert _classify_linear_system(eqs_4, funcs_2, t) == answer_4 + + eqs_5 = (5*x1 + 12*x(t) - 6*(y(t)) + x2, (2*y1 - 11*x(t) + 3*y(t)), (z1 - w(t)), (w1 - z(t))) + answer_5 = {'no_of_equation': 4, 'eq': (12*x(t) - 6*y(t) + 5*Derivative(x(t), t) + Derivative(x(t), (t, 2)), + -11*x(t) + 3*y(t) + 2*Derivative(y(t), t), -w(t) + Derivative(z(t), t), -z(t) + Derivative(w(t), + t)), 'func': [x(t), y(t), z(t), w(t)], 'order': {x(t): 2, y(t): 1, z(t): 1, w(t): 1}, 'is_linear': + True, 'is_homogeneous': True, 'is_general': True, 'type_of_equation': 'type0', 'is_higher_order': True} + assert _classify_linear_system(eqs_5, funcs_2, t) == answer_5 + + eqs_6 = (Eq(x1, 3*y(t) - 11*z(t)), Eq(y1, 7*z(t) - 3*x(t)), Eq(z1, 11*x(t) - 7*y(t))) + answer_6 = {'no_of_equation': 3, 'eq': (Eq(Derivative(x(t), t), 3*y(t) - 11*z(t)), Eq(Derivative(y(t), t), -3*x(t) + 7*z(t)), + Eq(Derivative(z(t), t), 11*x(t) - 7*y(t))), 'func': [x(t), y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, + 'is_linear': True, 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [ 0, -3, 11], + [ 3, 0, -7], + [-11, 7, 0]]), + 'type_of_equation': 'type1', 'is_general': True} + + assert _classify_linear_system(eqs_6, funcs_2[:-1], t) == answer_6 + + eqs_7 = (Eq(x1, y(t)), Eq(y1, x(t))) + answer_7 = {'no_of_equation': 2, 'eq': (Eq(Derivative(x(t), t), y(t)), Eq(Derivative(y(t), t), x(t))), + 'func': [x(t), y(t)], 'order': {x(t): 1, y(t): 1}, 'is_linear': True, 'is_constant': True, + 'is_homogeneous': True, 'func_coeff': -Matrix([ + [ 0, -1], + [-1, 0]]), + 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eqs_7, funcs, t) == answer_7 + + eqs_8 = (Eq(x1, 21*x(t)), Eq(y1, 17*x(t) + 3*y(t)), Eq(z1, 5*x(t) + 7*y(t) + 9*z(t))) + answer_8 = {'no_of_equation': 3, 'eq': (Eq(Derivative(x(t), t), 21*x(t)), Eq(Derivative(y(t), t), 17*x(t) + 3*y(t)), + Eq(Derivative(z(t), t), 5*x(t) + 7*y(t) + 9*z(t))), 'func': [x(t), y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, + 'is_linear': True, 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [-21, 0, 0], + [-17, -3, 0], + [ -5, -7, -9]]), + 'type_of_equation': 'type1', 'is_general': True} + + assert _classify_linear_system(eqs_8, funcs_2[:-1], t) == answer_8 + + eqs_9 = (Eq(x1, 4*x(t) + 5*y(t) + 2*z(t)), Eq(y1, x(t) + 13*y(t) + 9*z(t)), Eq(z1, 32*x(t) + 41*y(t) + 11*z(t))) + answer_9 = {'no_of_equation': 3, 'eq': (Eq(Derivative(x(t), t), 4*x(t) + 5*y(t) + 2*z(t)), + Eq(Derivative(y(t), t), x(t) + 13*y(t) + 9*z(t)), Eq(Derivative(z(t), t), 32*x(t) + 41*y(t) + 11*z(t))), + 'func': [x(t), y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, + 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [ -4, -5, -2], + [ -1, -13, -9], + [-32, -41, -11]]), + 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eqs_9, funcs_2[:-1], t) == answer_9 + + eqs_10 = (Eq(3*x1, 4*5*(y(t) - z(t))), Eq(4*y1, 3*5*(z(t) - x(t))), Eq(5*z1, 3*4*(x(t) - y(t)))) + answer_10 = {'no_of_equation': 3, 'eq': (Eq(3*Derivative(x(t), t), 20*y(t) - 20*z(t)), + Eq(4*Derivative(y(t), t), -15*x(t) + 15*z(t)), Eq(5*Derivative(z(t), t), 12*x(t) - 12*y(t))), + 'func': [x(t), y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, + 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [ 0, Rational(-20, 3), Rational(20, 3)], + [Rational(15, 4), 0, Rational(-15, 4)], + [Rational(-12, 5), Rational(12, 5), 0]]), + 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eqs_10, funcs_2[:-1], t) == answer_10 + + eq11 = (Eq(x1, 3*y(t) - 11*z(t)), Eq(y1, 7*z(t) - 3*x(t)), Eq(z1, 11*x(t) - 7*y(t))) + sol11 = {'no_of_equation': 3, 'eq': (Eq(Derivative(x(t), t), 3*y(t) - 11*z(t)), Eq(Derivative(y(t), t), -3*x(t) + 7*z(t)), + Eq(Derivative(z(t), t), 11*x(t) - 7*y(t))), 'func': [x(t), y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, + 'is_linear': True, 'is_constant': True, 'is_homogeneous': True, 'func_coeff': -Matrix([ + [ 0, -3, 11], [ 3, 0, -7], [-11, 7, 0]]), 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eq11, funcs_2[:-1], t) == sol11 + + eq12 = (Eq(Derivative(x(t), t), y(t)), Eq(Derivative(y(t), t), x(t))) + sol12 = {'no_of_equation': 2, 'eq': (Eq(Derivative(x(t), t), y(t)), Eq(Derivative(y(t), t), x(t))), + 'func': [x(t), y(t)], 'order': {x(t): 1, y(t): 1}, 'is_linear': True, 'is_constant': True, + 'is_homogeneous': True, 'func_coeff': -Matrix([ + [0, -1], + [-1, 0]]), 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eq12, [x(t), y(t)], t) == sol12 + + eq13 = (Eq(Derivative(x(t), t), 21*x(t)), Eq(Derivative(y(t), t), 17*x(t) + 3*y(t)), + Eq(Derivative(z(t), t), 5*x(t) + 7*y(t) + 9*z(t))) + sol13 = {'no_of_equation': 3, 'eq': ( + Eq(Derivative(x(t), t), 21 * x(t)), Eq(Derivative(y(t), t), 17 * x(t) + 3 * y(t)), + Eq(Derivative(z(t), t), 5 * x(t) + 7 * y(t) + 9 * z(t))), 'func': [x(t), y(t), z(t)], + 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [-21, 0, 0], + [-17, -3, 0], + [-5, -7, -9]]), 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eq13, [x(t), y(t), z(t)], t) == sol13 + + eq14 = ( + Eq(Derivative(x(t), t), 4*x(t) + 5*y(t) + 2*z(t)), Eq(Derivative(y(t), t), x(t) + 13*y(t) + 9*z(t)), + Eq(Derivative(z(t), t), 32*x(t) + 41*y(t) + 11*z(t))) + sol14 = {'no_of_equation': 3, 'eq': ( + Eq(Derivative(x(t), t), 4 * x(t) + 5 * y(t) + 2 * z(t)), Eq(Derivative(y(t), t), x(t) + 13 * y(t) + 9 * z(t)), + Eq(Derivative(z(t), t), 32 * x(t) + 41 * y(t) + 11 * z(t))), 'func': [x(t), y(t), z(t)], + 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [-4, -5, -2], + [-1, -13, -9], + [-32, -41, -11]]), 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eq14, [x(t), y(t), z(t)], t) == sol14 + + eq15 = (Eq(3*Derivative(x(t), t), 20*y(t) - 20*z(t)), Eq(4*Derivative(y(t), t), -15*x(t) + 15*z(t)), + Eq(5*Derivative(z(t), t), 12*x(t) - 12*y(t))) + sol15 = {'no_of_equation': 3, 'eq': ( + Eq(3 * Derivative(x(t), t), 20 * y(t) - 20 * z(t)), Eq(4 * Derivative(y(t), t), -15 * x(t) + 15 * z(t)), + Eq(5 * Derivative(z(t), t), 12 * x(t) - 12 * y(t))), 'func': [x(t), y(t), z(t)], + 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, 'is_constant': True, 'is_homogeneous': True, + 'func_coeff': -Matrix([ + [0, Rational(-20, 3), Rational(20, 3)], + [Rational(15, 4), 0, Rational(-15, 4)], + [Rational(-12, 5), Rational(12, 5), 0]]), 'type_of_equation': 'type1', 'is_general': True} + assert _classify_linear_system(eq15, [x(t), y(t), z(t)], t) == sol15 + + # Constant coefficient homogeneous ODEs + eq1 = (Eq(diff(x(t), t), x(t) + y(t) + 9), Eq(diff(y(t), t), 2*x(t) + 5*y(t) + 23)) + sol1 = {'no_of_equation': 2, 'eq': (Eq(Derivative(x(t), t), x(t) + y(t) + 9), + Eq(Derivative(y(t), t), 2*x(t) + 5*y(t) + 23)), 'func': [x(t), y(t)], + 'order': {x(t): 1, y(t): 1}, 'is_linear': True, 'is_constant': True, 'is_homogeneous': False, 'is_general': True, + 'func_coeff': -Matrix([[-1, -1], [-2, -5]]), 'rhs': Matrix([[ 9], [23]]), 'type_of_equation': 'type2'} + assert _classify_linear_system(eq1, funcs, t) == sol1 + + # Non constant coefficient homogeneous ODEs + eq1 = (Eq(diff(x(t), t), 5*t*x(t) + 2*y(t)), Eq(diff(y(t), t), 2*x(t) + 5*t*y(t))) + sol1 = {'no_of_equation': 2, 'eq': (Eq(Derivative(x(t), t), 5*t*x(t) + 2*y(t)), Eq(Derivative(y(t), t), 5*t*y(t) + 2*x(t))), + 'func': [x(t), y(t)], 'order': {x(t): 1, y(t): 1}, 'is_linear': True, 'is_constant': False, + 'is_homogeneous': True, 'func_coeff': -Matrix([ [-5*t, -2], [ -2, -5*t]]), 'commutative_antiderivative': Matrix([ + [5*t**2/2, 2*t], [ 2*t, 5*t**2/2]]), 'type_of_equation': 'type3', 'is_general': True} + assert _classify_linear_system(eq1, funcs, t) == sol1 + + # Non constant coefficient non-homogeneous ODEs + eq1 = [Eq(x1, x(t) + t*y(t) + t), Eq(y1, t*x(t) + y(t))] + sol1 = {'no_of_equation': 2, 'eq': [Eq(Derivative(x(t), t), t*y(t) + t + x(t)), Eq(Derivative(y(t), t), + t*x(t) + y(t))], 'func': [x(t), y(t)], 'order': {x(t): 1, y(t): 1}, 'is_linear': True, + 'is_constant': False, 'is_homogeneous': False, 'is_general': True, 'func_coeff': -Matrix([ [-1, -t], + [-t, -1]]), 'commutative_antiderivative': Matrix([ [ t, t**2/2], [t**2/2, t]]), 'rhs': + Matrix([ [t], [0]]), 'type_of_equation': 'type4'} + assert _classify_linear_system(eq1, funcs, t) == sol1 + + eq2 = [Eq(x1, t*x(t) + t*y(t) + t), Eq(y1, t*x(t) + t*y(t) + cos(t))] + sol2 = {'no_of_equation': 2, 'eq': [Eq(Derivative(x(t), t), t*x(t) + t*y(t) + t), Eq(Derivative(y(t), t), + t*x(t) + t*y(t) + cos(t))], 'func': [x(t), y(t)], 'order': {x(t): 1, y(t): 1}, 'is_linear': True, + 'is_homogeneous': False, 'is_general': True, 'rhs': Matrix([ [ t], [cos(t)]]), 'func_coeff': + Matrix([ [t, t], [t, t]]), 'is_constant': False, 'type_of_equation': 'type4', + 'commutative_antiderivative': Matrix([ [t**2/2, t**2/2], [t**2/2, t**2/2]])} + assert _classify_linear_system(eq2, funcs, t) == sol2 + + eq3 = [Eq(x1, t*(x(t) + y(t) + z(t) + 1)), Eq(y1, t*(x(t) + y(t) + z(t))), Eq(z1, t*(x(t) + y(t) + z(t)))] + sol3 = {'no_of_equation': 3, 'eq': [Eq(Derivative(x(t), t), t*(x(t) + y(t) + z(t) + 1)), + Eq(Derivative(y(t), t), t*(x(t) + y(t) + z(t))), Eq(Derivative(z(t), t), t*(x(t) + y(t) + z(t)))], + 'func': [x(t), y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, 'is_constant': + False, 'is_homogeneous': False, 'is_general': True, 'func_coeff': -Matrix([ [-t, -t, -t], [-t, -t, + -t], [-t, -t, -t]]), 'commutative_antiderivative': Matrix([ [t**2/2, t**2/2, t**2/2], [t**2/2, + t**2/2, t**2/2], [t**2/2, t**2/2, t**2/2]]), 'rhs': Matrix([ [t], [0], [0]]), 'type_of_equation': + 'type4'} + assert _classify_linear_system(eq3, funcs_2[:-1], t) == sol3 + + eq4 = [Eq(x1, x(t) + y(t) + t*z(t) + 1), Eq(y1, x(t) + t*y(t) + z(t) + 10), Eq(z1, t*x(t) + y(t) + z(t) + t)] + sol4 = {'no_of_equation': 3, 'eq': [Eq(Derivative(x(t), t), t*z(t) + x(t) + y(t) + 1), Eq(Derivative(y(t), + t), t*y(t) + x(t) + z(t) + 10), Eq(Derivative(z(t), t), t*x(t) + t + y(t) + z(t))], 'func': [x(t), + y(t), z(t)], 'order': {x(t): 1, y(t): 1, z(t): 1}, 'is_linear': True, 'is_constant': False, + 'is_homogeneous': False, 'is_general': True, 'func_coeff': -Matrix([ [-1, -1, -t], [-1, -t, -1], [-t, + -1, -1]]), 'commutative_antiderivative': Matrix([ [ t, t, t**2/2], [ t, t**2/2, + t], [t**2/2, t, t]]), 'rhs': Matrix([ [ 1], [10], [ t]]), 'type_of_equation': 'type4'} + assert _classify_linear_system(eq4, funcs_2[:-1], t) == sol4 + + sum_terms = t*(x(t) + y(t) + z(t) + w(t)) + eq5 = [Eq(x1, sum_terms), Eq(y1, sum_terms), Eq(z1, sum_terms + 1), Eq(w1, sum_terms)] + sol5 = {'no_of_equation': 4, 'eq': [Eq(Derivative(x(t), t), t*(w(t) + x(t) + y(t) + z(t))), + Eq(Derivative(y(t), t), t*(w(t) + x(t) + y(t) + z(t))), Eq(Derivative(z(t), t), t*(w(t) + x(t) + + y(t) + z(t)) + 1), Eq(Derivative(w(t), t), t*(w(t) + x(t) + y(t) + z(t)))], 'func': [x(t), y(t), + z(t), w(t)], 'order': {x(t): 1, y(t): 1, z(t): 1, w(t): 1}, 'is_linear': True, 'is_constant': False, + 'is_homogeneous': False, 'is_general': True, 'func_coeff': -Matrix([ [-t, -t, -t, -t], [-t, -t, -t, + -t], [-t, -t, -t, -t], [-t, -t, -t, -t]]), 'commutative_antiderivative': Matrix([ [t**2/2, t**2/2, + t**2/2, t**2/2], [t**2/2, t**2/2, t**2/2, t**2/2], [t**2/2, t**2/2, t**2/2, t**2/2], [t**2/2, + t**2/2, t**2/2, t**2/2]]), 'rhs': Matrix([ [0], [0], [1], [0]]), 'type_of_equation': 'type4'} + assert _classify_linear_system(eq5, funcs_2, t) == sol5 + + # Second Order + t_ = symbols("t_") + + eq1 = (Eq(9*x(t) + 7*y(t) + 4*Derivative(x(t), t) + Derivative(x(t), (t, 2)) + 3*Derivative(y(t), t), 11*exp(I*t)), + Eq(3*x(t) + 12*y(t) + 5*Derivative(x(t), t) + 8*Derivative(y(t), t) + Derivative(y(t), (t, 2)), 2*exp(I*t))) + sol1 = {'no_of_equation': 2, 'eq': (Eq(9*x(t) + 7*y(t) + 4*Derivative(x(t), t) + Derivative(x(t), (t, 2)) + + 3*Derivative(y(t), t), 11*exp(I*t)), Eq(3*x(t) + 12*y(t) + 5*Derivative(x(t), t) + + 8*Derivative(y(t), t) + Derivative(y(t), (t, 2)), 2*exp(I*t))), 'func': [x(t), y(t)], 'order': + {x(t): 2, y(t): 2}, 'is_linear': True, 'is_homogeneous': False, 'is_general': True, 'rhs': Matrix([ + [11*exp(I*t)], [ 2*exp(I*t)]]), 'type_of_equation': 'type0', 'is_second_order': True, + 'is_higher_order': True} + assert _classify_linear_system(eq1, funcs, t) == sol1 + + eq2 = (Eq((4*t**2 + 7*t + 1)**2*Derivative(x(t), (t, 2)), 5*x(t) + 35*y(t)), + Eq((4*t**2 + 7*t + 1)**2*Derivative(y(t), (t, 2)), x(t) + 9*y(t))) + sol2 = {'no_of_equation': 2, 'eq': (Eq((4*t**2 + 7*t + 1)**2*Derivative(x(t), (t, 2)), 5*x(t) + 35*y(t)), + Eq((4*t**2 + 7*t + 1)**2*Derivative(y(t), (t, 2)), x(t) + 9*y(t))), 'func': [x(t), y(t)], 'order': + {x(t): 2, y(t): 2}, 'is_linear': True, 'is_homogeneous': True, 'is_general': True, + 'type_of_equation': 'type2', 'A0': Matrix([ [Rational(53, 4), 35], [ 1, Rational(69, 4)]]), 'g(t)': sqrt(4*t**2 + 7*t + + 1), 'tau': sqrt(33)*log(t - sqrt(33)/8 + Rational(7, 8))/33 - sqrt(33)*log(t + sqrt(33)/8 + Rational(7, 8))/33, + 'is_transformed': True, 't_': t_, 'is_second_order': True, 'is_higher_order': True} + assert _classify_linear_system(eq2, funcs, t) == sol2 + + eq3 = ((t*Derivative(x(t), t) - x(t))*log(t) + (t*Derivative(y(t), t) - y(t))*exp(t) + Derivative(x(t), (t, 2)), + t**2*(t*Derivative(x(t), t) - x(t)) + t*(t*Derivative(y(t), t) - y(t)) + Derivative(y(t), (t, 2))) + sol3 = {'no_of_equation': 2, 'eq': ((t*Derivative(x(t), t) - x(t))*log(t) + (t*Derivative(y(t), t) - + y(t))*exp(t) + Derivative(x(t), (t, 2)), t**2*(t*Derivative(x(t), t) - x(t)) + t*(t*Derivative(y(t), + t) - y(t)) + Derivative(y(t), (t, 2))), 'func': [x(t), y(t)], 'order': {x(t): 2, y(t): 2}, + 'is_linear': True, 'is_homogeneous': True, 'is_general': True, 'type_of_equation': 'type1', 'A1': + Matrix([ [-t*log(t), -t*exp(t)], [ -t**3, -t**2]]), 'is_second_order': True, + 'is_higher_order': True} + assert _classify_linear_system(eq3, funcs, t) == sol3 + + eq4 = (Eq(x2, k*x(t) - l*y1), Eq(y2, l*x1 + k*y(t))) + sol4 = {'no_of_equation': 2, 'eq': (Eq(Derivative(x(t), (t, 2)), k*x(t) - l*Derivative(y(t), t)), + Eq(Derivative(y(t), (t, 2)), k*y(t) + l*Derivative(x(t), t))), 'func': [x(t), y(t)], 'order': {x(t): + 2, y(t): 2}, 'is_linear': True, 'is_homogeneous': True, 'is_general': True, 'type_of_equation': + 'type0', 'is_second_order': True, 'is_higher_order': True} + assert _classify_linear_system(eq4, funcs, t) == sol4 + + + # Multiple matches + + f, g = symbols("f g", cls=Function) + y, t_ = symbols("y t_") + funcs = [f(t), g(t)] + + eq1 = [Eq(Derivative(f(t), t)**2 - 2*Derivative(f(t), t) + 1, 4), + Eq(-y*f(t) + Derivative(g(t), t), 0)] + sol1 = {'is_implicit': True, + 'canon_eqs': [[Eq(Derivative(f(t), t), -1), Eq(Derivative(g(t), t), y*f(t))], + [Eq(Derivative(f(t), t), 3), Eq(Derivative(g(t), t), y*f(t))]]} + assert _classify_linear_system(eq1, funcs, t) == sol1 + + raises(ValueError, lambda: _classify_linear_system(eq1, funcs[:1], t)) + + eq2 = [Eq(Derivative(f(t), t), (2*f(t) + g(t) + 1)/t), Eq(Derivative(g(t), t), (f(t) + 2*g(t))/t)] + sol2 = {'no_of_equation': 2, 'eq': [Eq(Derivative(f(t), t), (2*f(t) + g(t) + 1)/t), Eq(Derivative(g(t), t), + (f(t) + 2*g(t))/t)], 'func': [f(t), g(t)], 'order': {f(t): 1, g(t): 1}, 'is_linear': True, + 'is_homogeneous': False, 'is_general': True, 'rhs': Matrix([ [1], [0]]), 'func_coeff': Matrix([ [2, + 1], [1, 2]]), 'is_constant': False, 'type_of_equation': 'type6', 't_': t_, 'tau': log(t), + 'commutative_antiderivative': Matrix([ [2*log(t), log(t)], [ log(t), 2*log(t)]])} + assert _classify_linear_system(eq2, funcs, t) == sol2 + + eq3 = [Eq(Derivative(f(t), t), (2*f(t) + g(t))/t), Eq(Derivative(g(t), t), (f(t) + 2*g(t))/t)] + sol3 = {'no_of_equation': 2, 'eq': [Eq(Derivative(f(t), t), (2*f(t) + g(t))/t), Eq(Derivative(g(t), t), + (f(t) + 2*g(t))/t)], 'func': [f(t), g(t)], 'order': {f(t): 1, g(t): 1}, 'is_linear': True, + 'is_homogeneous': True, 'is_general': True, 'func_coeff': Matrix([ [2, 1], [1, 2]]), 'is_constant': + False, 'type_of_equation': 'type5', 't_': t_, 'rhs': Matrix([ [0], [0]]), 'tau': log(t), + 'commutative_antiderivative': Matrix([ [2*log(t), log(t)], [ log(t), 2*log(t)]])} + assert _classify_linear_system(eq3, funcs, t) == sol3 + + +def test_matrix_exp(): + from sympy.matrices.dense import Matrix, eye, zeros + from sympy.solvers.ode.systems import matrix_exp + t = Symbol('t') + + for n in range(1, 6+1): + assert matrix_exp(zeros(n), t) == eye(n) + + for n in range(1, 6+1): + A = eye(n) + expAt = exp(t) * eye(n) + assert matrix_exp(A, t) == expAt + + for n in range(1, 6+1): + A = Matrix(n, n, lambda i,j: i+1 if i==j else 0) + expAt = Matrix(n, n, lambda i,j: exp((i+1)*t) if i==j else 0) + assert matrix_exp(A, t) == expAt + + A = Matrix([[0, 1], [-1, 0]]) + expAt = Matrix([[cos(t), sin(t)], [-sin(t), cos(t)]]) + assert matrix_exp(A, t) == expAt + + A = Matrix([[2, -5], [2, -4]]) + expAt = Matrix([ + [3*exp(-t)*sin(t) + exp(-t)*cos(t), -5*exp(-t)*sin(t)], + [2*exp(-t)*sin(t), -3*exp(-t)*sin(t) + exp(-t)*cos(t)] + ]) + assert matrix_exp(A, t) == expAt + + A = Matrix([[21, 17, 6], [-5, -1, -6], [4, 4, 16]]) + # TO update this. + # expAt = Matrix([ + # [(8*t*exp(12*t) + 5*exp(12*t) - 1)*exp(4*t)/4, + # (8*t*exp(12*t) + 5*exp(12*t) - 5)*exp(4*t)/4, + # (exp(12*t) - 1)*exp(4*t)/2], + # [(-8*t*exp(12*t) - exp(12*t) + 1)*exp(4*t)/4, + # (-8*t*exp(12*t) - exp(12*t) + 5)*exp(4*t)/4, + # (-exp(12*t) + 1)*exp(4*t)/2], + # [4*t*exp(16*t), 4*t*exp(16*t), exp(16*t)]]) + expAt = Matrix([ + [2*t*exp(16*t) + 5*exp(16*t)/4 - exp(4*t)/4, 2*t*exp(16*t) + 5*exp(16*t)/4 - 5*exp(4*t)/4, exp(16*t)/2 - exp(4*t)/2], + [ -2*t*exp(16*t) - exp(16*t)/4 + exp(4*t)/4, -2*t*exp(16*t) - exp(16*t)/4 + 5*exp(4*t)/4, -exp(16*t)/2 + exp(4*t)/2], + [ 4*t*exp(16*t), 4*t*exp(16*t), exp(16*t)] + ]) + assert matrix_exp(A, t) == expAt + + A = Matrix([[1, 1, 0, 0], + [0, 1, 1, 0], + [0, 0, 1, -S(1)/8], + [0, 0, S(1)/2, S(1)/2]]) + expAt = Matrix([ + [exp(t), t*exp(t), 4*t*exp(3*t/4) + 8*t*exp(t) + 48*exp(3*t/4) - 48*exp(t), + -2*t*exp(3*t/4) - 2*t*exp(t) - 16*exp(3*t/4) + 16*exp(t)], + [0, exp(t), -t*exp(3*t/4) - 8*exp(3*t/4) + 8*exp(t), t*exp(3*t/4)/2 + 2*exp(3*t/4) - 2*exp(t)], + [0, 0, t*exp(3*t/4)/4 + exp(3*t/4), -t*exp(3*t/4)/8], + [0, 0, t*exp(3*t/4)/2, -t*exp(3*t/4)/4 + exp(3*t/4)] + ]) + assert matrix_exp(A, t) == expAt + + A = Matrix([ + [ 0, 1, 0, 0], + [-1, 0, 0, 0], + [ 0, 0, 0, 1], + [ 0, 0, -1, 0]]) + + expAt = Matrix([ + [ cos(t), sin(t), 0, 0], + [-sin(t), cos(t), 0, 0], + [ 0, 0, cos(t), sin(t)], + [ 0, 0, -sin(t), cos(t)]]) + assert matrix_exp(A, t) == expAt + + A = Matrix([ + [ 0, 1, 1, 0], + [-1, 0, 0, 1], + [ 0, 0, 0, 1], + [ 0, 0, -1, 0]]) + + expAt = Matrix([ + [ cos(t), sin(t), t*cos(t), t*sin(t)], + [-sin(t), cos(t), -t*sin(t), t*cos(t)], + [ 0, 0, cos(t), sin(t)], + [ 0, 0, -sin(t), cos(t)]]) + assert matrix_exp(A, t) == expAt + + # This case is unacceptably slow right now but should be solvable... + #a, b, c, d, e, f = symbols('a b c d e f') + #A = Matrix([ + #[-a, b, c, d], + #[ a, -b, e, 0], + #[ 0, 0, -c - e - f, 0], + #[ 0, 0, f, -d]]) + + A = Matrix([[0, I], [I, 0]]) + expAt = Matrix([ + [exp(I*t)/2 + exp(-I*t)/2, exp(I*t)/2 - exp(-I*t)/2], + [exp(I*t)/2 - exp(-I*t)/2, exp(I*t)/2 + exp(-I*t)/2]]) + assert matrix_exp(A, t) == expAt + + # Testing Errors + M = Matrix([[1, 2, 3], [4, 5, 6], [7, 7, 7]]) + M1 = Matrix([[t, 1], [1, 1]]) + + raises(ValueError, lambda: matrix_exp(M[:, :2], t)) + raises(ValueError, lambda: matrix_exp(M[:2, :], t)) + raises(ValueError, lambda: matrix_exp(M1, t)) + raises(ValueError, lambda: matrix_exp(M1[:1, :1], t)) + + +def test_canonical_odes(): + f, g, h = symbols('f g h', cls=Function) + x = symbols('x') + funcs = [f(x), g(x), h(x)] + + eqs1 = [Eq(f(x).diff(x, x), f(x) + 2*g(x)), Eq(g(x) + 1, g(x).diff(x) + f(x))] + sol1 = [[Eq(Derivative(f(x), (x, 2)), f(x) + 2*g(x)), Eq(Derivative(g(x), x), -f(x) + g(x) + 1)]] + assert canonical_odes(eqs1, funcs[:2], x) == sol1 + + eqs2 = [Eq(f(x).diff(x), h(x).diff(x) + f(x)), Eq(g(x).diff(x)**2, f(x) + h(x)), Eq(h(x).diff(x), f(x))] + sol2 = [[Eq(Derivative(f(x), x), 2*f(x)), Eq(Derivative(g(x), x), -sqrt(f(x) + h(x))), Eq(Derivative(h(x), x), f(x))], + [Eq(Derivative(f(x), x), 2*f(x)), Eq(Derivative(g(x), x), sqrt(f(x) + h(x))), Eq(Derivative(h(x), x), f(x))]] + assert canonical_odes(eqs2, funcs, x) == sol2 + + +def test_sysode_linear_neq_order1_type1(): + + f, g, x, y, h = symbols('f g x y h', cls=Function) + a, b, c, t = symbols('a b c t') + + eqs1 = [Eq(Derivative(x(t), t), x(t)), + Eq(Derivative(y(t), t), y(t))] + sol1 = [Eq(x(t), C1*exp(t)), + Eq(y(t), C2*exp(t))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + eqs2 = [Eq(Derivative(x(t), t), 2*x(t)), + Eq(Derivative(y(t), t), 3*y(t))] + sol2 = [Eq(x(t), C1*exp(2*t)), + Eq(y(t), C2*exp(3*t))] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + eqs3 = [Eq(Derivative(x(t), t), a*x(t)), + Eq(Derivative(y(t), t), a*y(t))] + sol3 = [Eq(x(t), C1*exp(a*t)), + Eq(y(t), C2*exp(a*t))] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0]) + + # Regression test case for issue #15474 + # https://github.com/sympy/sympy/issues/15474 + eqs4 = [Eq(Derivative(x(t), t), a*x(t)), + Eq(Derivative(y(t), t), b*y(t))] + sol4 = [Eq(x(t), C1*exp(a*t)), + Eq(y(t), C2*exp(b*t))] + assert dsolve(eqs4) == sol4 + assert checksysodesol(eqs4, sol4) == (True, [0, 0]) + + eqs5 = [Eq(Derivative(x(t), t), -y(t)), + Eq(Derivative(y(t), t), x(t))] + sol5 = [Eq(x(t), -C1*sin(t) - C2*cos(t)), + Eq(y(t), C1*cos(t) - C2*sin(t))] + assert dsolve(eqs5) == sol5 + assert checksysodesol(eqs5, sol5) == (True, [0, 0]) + + eqs6 = [Eq(Derivative(x(t), t), -2*y(t)), + Eq(Derivative(y(t), t), 2*x(t))] + sol6 = [Eq(x(t), -C1*sin(2*t) - C2*cos(2*t)), + Eq(y(t), C1*cos(2*t) - C2*sin(2*t))] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0]) + + eqs7 = [Eq(Derivative(x(t), t), I*y(t)), + Eq(Derivative(y(t), t), I*x(t))] + sol7 = [Eq(x(t), -C1*exp(-I*t) + C2*exp(I*t)), + Eq(y(t), C1*exp(-I*t) + C2*exp(I*t))] + assert dsolve(eqs7) == sol7 + assert checksysodesol(eqs7, sol7) == (True, [0, 0]) + + eqs8 = [Eq(Derivative(x(t), t), -a*y(t)), + Eq(Derivative(y(t), t), a*x(t))] + sol8 = [Eq(x(t), -I*C1*exp(-I*a*t) + I*C2*exp(I*a*t)), + Eq(y(t), C1*exp(-I*a*t) + C2*exp(I*a*t))] + assert dsolve(eqs8) == sol8 + assert checksysodesol(eqs8, sol8) == (True, [0, 0]) + + eqs9 = [Eq(Derivative(x(t), t), x(t) + y(t)), + Eq(Derivative(y(t), t), x(t) - y(t))] + sol9 = [Eq(x(t), C1*(1 - sqrt(2))*exp(-sqrt(2)*t) + C2*(1 + sqrt(2))*exp(sqrt(2)*t)), + Eq(y(t), C1*exp(-sqrt(2)*t) + C2*exp(sqrt(2)*t))] + assert dsolve(eqs9) == sol9 + assert checksysodesol(eqs9, sol9) == (True, [0, 0]) + + eqs10 = [Eq(Derivative(x(t), t), x(t) + y(t)), + Eq(Derivative(y(t), t), x(t) + y(t))] + sol10 = [Eq(x(t), -C1 + C2*exp(2*t)), + Eq(y(t), C1 + C2*exp(2*t))] + assert dsolve(eqs10) == sol10 + assert checksysodesol(eqs10, sol10) == (True, [0, 0]) + + eqs11 = [Eq(Derivative(x(t), t), 2*x(t) + y(t)), + Eq(Derivative(y(t), t), -x(t) + 2*y(t))] + sol11 = [Eq(x(t), C1*exp(2*t)*sin(t) + C2*exp(2*t)*cos(t)), + Eq(y(t), C1*exp(2*t)*cos(t) - C2*exp(2*t)*sin(t))] + assert dsolve(eqs11) == sol11 + assert checksysodesol(eqs11, sol11) == (True, [0, 0]) + + eqs12 = [Eq(Derivative(x(t), t), x(t) + 2*y(t)), + Eq(Derivative(y(t), t), 2*x(t) + y(t))] + sol12 = [Eq(x(t), -C1*exp(-t) + C2*exp(3*t)), + Eq(y(t), C1*exp(-t) + C2*exp(3*t))] + assert dsolve(eqs12) == sol12 + assert checksysodesol(eqs12, sol12) == (True, [0, 0]) + + eqs13 = [Eq(Derivative(x(t), t), 4*x(t) + y(t)), + Eq(Derivative(y(t), t), -x(t) + 2*y(t))] + sol13 = [Eq(x(t), C2*t*exp(3*t) + (C1 + C2)*exp(3*t)), + Eq(y(t), -C1*exp(3*t) - C2*t*exp(3*t))] + assert dsolve(eqs13) == sol13 + assert checksysodesol(eqs13, sol13) == (True, [0, 0]) + + eqs14 = [Eq(Derivative(x(t), t), a*y(t)), + Eq(Derivative(y(t), t), a*x(t))] + sol14 = [Eq(x(t), -C1*exp(-a*t) + C2*exp(a*t)), + Eq(y(t), C1*exp(-a*t) + C2*exp(a*t))] + assert dsolve(eqs14) == sol14 + assert checksysodesol(eqs14, sol14) == (True, [0, 0]) + + eqs15 = [Eq(Derivative(x(t), t), a*y(t)), + Eq(Derivative(y(t), t), b*x(t))] + sol15 = [Eq(x(t), -C1*a*exp(-t*sqrt(a*b))/sqrt(a*b) + C2*a*exp(t*sqrt(a*b))/sqrt(a*b)), + Eq(y(t), C1*exp(-t*sqrt(a*b)) + C2*exp(t*sqrt(a*b)))] + assert dsolve(eqs15) == sol15 + assert checksysodesol(eqs15, sol15) == (True, [0, 0]) + + eqs16 = [Eq(Derivative(x(t), t), a*x(t) + b*y(t)), + Eq(Derivative(y(t), t), c*x(t))] + sol16 = [Eq(x(t), -2*C1*b*exp(t*(a + sqrt(a**2 + 4*b*c))/2)/(a - sqrt(a**2 + 4*b*c)) - 2*C2*b*exp(t*(a - + sqrt(a**2 + 4*b*c))/2)/(a + sqrt(a**2 + 4*b*c))), + Eq(y(t), C1*exp(t*(a + sqrt(a**2 + 4*b*c))/2) + C2*exp(t*(a - sqrt(a**2 + 4*b*c))/2))] + assert dsolve(eqs16) == sol16 + assert checksysodesol(eqs16, sol16) == (True, [0, 0]) + + # Regression test case for issue #18562 + # https://github.com/sympy/sympy/issues/18562 + eqs17 = [Eq(Derivative(x(t), t), a*y(t) + x(t)), + Eq(Derivative(y(t), t), a*x(t) - y(t))] + sol17 = [Eq(x(t), C1*a*exp(t*sqrt(a**2 + 1))/(sqrt(a**2 + 1) - 1) - C2*a*exp(-t*sqrt(a**2 + 1))/(sqrt(a**2 + + 1) + 1)), + Eq(y(t), C1*exp(t*sqrt(a**2 + 1)) + C2*exp(-t*sqrt(a**2 + 1)))] + assert dsolve(eqs17) == sol17 + assert checksysodesol(eqs17, sol17) == (True, [0, 0]) + + eqs18 = [Eq(Derivative(x(t), t), 0), + Eq(Derivative(y(t), t), 0)] + sol18 = [Eq(x(t), C1), + Eq(y(t), C2)] + assert dsolve(eqs18) == sol18 + assert checksysodesol(eqs18, sol18) == (True, [0, 0]) + + eqs19 = [Eq(Derivative(x(t), t), 2*x(t) - y(t)), + Eq(Derivative(y(t), t), x(t))] + sol19 = [Eq(x(t), C2*t*exp(t) + (C1 + C2)*exp(t)), + Eq(y(t), C1*exp(t) + C2*t*exp(t))] + assert dsolve(eqs19) == sol19 + assert checksysodesol(eqs19, sol19) == (True, [0, 0]) + + eqs20 = [Eq(Derivative(x(t), t), x(t)), + Eq(Derivative(y(t), t), x(t) + y(t))] + sol20 = [Eq(x(t), C1*exp(t)), + Eq(y(t), C1*t*exp(t) + C2*exp(t))] + assert dsolve(eqs20) == sol20 + assert checksysodesol(eqs20, sol20) == (True, [0, 0]) + + eqs21 = [Eq(Derivative(x(t), t), 3*x(t)), + Eq(Derivative(y(t), t), x(t) + y(t))] + sol21 = [Eq(x(t), 2*C1*exp(3*t)), + Eq(y(t), C1*exp(3*t) + C2*exp(t))] + assert dsolve(eqs21) == sol21 + assert checksysodesol(eqs21, sol21) == (True, [0, 0]) + + eqs22 = [Eq(Derivative(x(t), t), 3*x(t)), + Eq(Derivative(y(t), t), y(t))] + sol22 = [Eq(x(t), C1*exp(3*t)), + Eq(y(t), C2*exp(t))] + assert dsolve(eqs22) == sol22 + assert checksysodesol(eqs22, sol22) == (True, [0, 0]) + + +@slow +def test_sysode_linear_neq_order1_type1_slow(): + + t = Symbol('t') + Z0 = Function('Z0') + Z1 = Function('Z1') + Z2 = Function('Z2') + Z3 = Function('Z3') + + k01, k10, k20, k21, k23, k30 = symbols('k01 k10 k20 k21 k23 k30') + + eqs1 = [Eq(Derivative(Z0(t), t), -k01*Z0(t) + k10*Z1(t) + k20*Z2(t) + k30*Z3(t)), + Eq(Derivative(Z1(t), t), k01*Z0(t) - k10*Z1(t) + k21*Z2(t)), + Eq(Derivative(Z2(t), t), (-k20 - k21 - k23)*Z2(t)), + Eq(Derivative(Z3(t), t), k23*Z2(t) - k30*Z3(t))] + sol1 = [Eq(Z0(t), C1*k10/k01 - C2*(k10 - k30)*exp(-k30*t)/(k01 + k10 - k30) - C3*(k10*(k20 + k21 - k30) - + k20**2 - k20*(k21 + k23 - k30) + k23*k30)*exp(-t*(k20 + k21 + k23))/(k23*(-k01 - k10 + k20 + k21 + + k23)) - C4*exp(-t*(k01 + k10))), + Eq(Z1(t), C1 - C2*k01*exp(-k30*t)/(k01 + k10 - k30) + C3*(-k01*(k20 + k21 - k30) + k20*k21 + k21**2 + + k21*(k23 - k30))*exp(-t*(k20 + k21 + k23))/(k23*(-k01 - k10 + k20 + k21 + k23)) + C4*exp(-t*(k01 + + k10))), + Eq(Z2(t), -C3*(k20 + k21 + k23 - k30)*exp(-t*(k20 + k21 + k23))/k23), + Eq(Z3(t), C2*exp(-k30*t) + C3*exp(-t*(k20 + k21 + k23)))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0, 0, 0]) + + x, y, z, u, v, w = symbols('x y z u v w', cls=Function) + k2, k3 = symbols('k2 k3') + a_b, a_c = symbols('a_b a_c', real=True) + + eqs2 = [Eq(Derivative(z(t), t), k2*y(t)), + Eq(Derivative(x(t), t), k3*y(t)), + Eq(Derivative(y(t), t), (-k2 - k3)*y(t))] + sol2 = [Eq(z(t), C1 - C2*k2*exp(-t*(k2 + k3))/(k2 + k3)), + Eq(x(t), -C2*k3*exp(-t*(k2 + k3))/(k2 + k3) + C3), + Eq(y(t), C2*exp(-t*(k2 + k3)))] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0, 0]) + + eqs3 = [4*u(t) - v(t) - 2*w(t) + Derivative(u(t), t), + 2*u(t) + v(t) - 2*w(t) + Derivative(v(t), t), + 5*u(t) + v(t) - 3*w(t) + Derivative(w(t), t)] + sol3 = [Eq(u(t), C3*exp(-2*t) + (C1/2 + sqrt(3)*C2/6)*cos(sqrt(3)*t) + sin(sqrt(3)*t)*(sqrt(3)*C1/6 + + C2*Rational(-1, 2))), + Eq(v(t), (C1/2 + sqrt(3)*C2/6)*cos(sqrt(3)*t) + sin(sqrt(3)*t)*(sqrt(3)*C1/6 + C2*Rational(-1, 2))), + Eq(w(t), C1*cos(sqrt(3)*t) - C2*sin(sqrt(3)*t) + C3*exp(-2*t))] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0, 0]) + + eqs4 = [Eq(Derivative(x(t), t), w(t)*Rational(-2, 9) + 2*x(t) + y(t) + z(t)*Rational(-8, 9)), + Eq(Derivative(y(t), t), w(t)*Rational(4, 9) + 2*y(t) + z(t)*Rational(16, 9)), + Eq(Derivative(z(t), t), w(t)*Rational(-2, 9) + z(t)*Rational(37, 9)), + Eq(Derivative(w(t), t), w(t)*Rational(44, 9) + z(t)*Rational(-4, 9))] + sol4 = [Eq(x(t), C1*exp(2*t) + C2*t*exp(2*t)), + Eq(y(t), C2*exp(2*t) + 2*C3*exp(4*t)), + Eq(z(t), 2*C3*exp(4*t) + C4*exp(5*t)*Rational(-1, 4)), + Eq(w(t), C3*exp(4*t) + C4*exp(5*t))] + assert dsolve(eqs4) == sol4 + assert checksysodesol(eqs4, sol4) == (True, [0, 0, 0, 0]) + + # Regression test case for issue #15574 + # https://github.com/sympy/sympy/issues/15574 + eq5 = [Eq(x(t).diff(t), x(t)), Eq(y(t).diff(t), y(t)), Eq(z(t).diff(t), z(t)), Eq(w(t).diff(t), w(t))] + sol5 = [Eq(x(t), C1*exp(t)), Eq(y(t), C2*exp(t)), Eq(z(t), C3*exp(t)), Eq(w(t), C4*exp(t))] + assert dsolve(eq5) == sol5 + assert checksysodesol(eq5, sol5) == (True, [0, 0, 0, 0]) + + eqs6 = [Eq(Derivative(x(t), t), x(t) + y(t)), + Eq(Derivative(y(t), t), y(t) + z(t)), + Eq(Derivative(z(t), t), w(t)*Rational(-1, 8) + z(t)), + Eq(Derivative(w(t), t), w(t)/2 + z(t)/2)] + sol6 = [Eq(x(t), C1*exp(t) + C2*t*exp(t) + 4*C4*t*exp(t*Rational(3, 4)) + (4*C3 + 48*C4)*exp(t*Rational(3, + 4))), + Eq(y(t), C2*exp(t) - C4*t*exp(t*Rational(3, 4)) - (C3 + 8*C4)*exp(t*Rational(3, 4))), + Eq(z(t), C4*t*exp(t*Rational(3, 4))/4 + (C3/4 + C4)*exp(t*Rational(3, 4))), + Eq(w(t), C3*exp(t*Rational(3, 4))/2 + C4*t*exp(t*Rational(3, 4))/2)] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0, 0, 0]) + + # Regression test case for issue #15574 + # https://github.com/sympy/sympy/issues/15574 + eq7 = [Eq(Derivative(x(t), t), x(t)), Eq(Derivative(y(t), t), y(t)), Eq(Derivative(z(t), t), z(t)), + Eq(Derivative(w(t), t), w(t)), Eq(Derivative(u(t), t), u(t))] + sol7 = [Eq(x(t), C1*exp(t)), Eq(y(t), C2*exp(t)), Eq(z(t), C3*exp(t)), Eq(w(t), C4*exp(t)), + Eq(u(t), C5*exp(t))] + assert dsolve(eq7) == sol7 + assert checksysodesol(eq7, sol7) == (True, [0, 0, 0, 0, 0]) + + eqs8 = [Eq(Derivative(x(t), t), 2*x(t) + y(t)), + Eq(Derivative(y(t), t), 2*y(t)), + Eq(Derivative(z(t), t), 4*z(t)), + Eq(Derivative(w(t), t), u(t) + 5*w(t)), + Eq(Derivative(u(t), t), 5*u(t))] + sol8 = [Eq(x(t), C1*exp(2*t) + C2*t*exp(2*t)), + Eq(y(t), C2*exp(2*t)), + Eq(z(t), C3*exp(4*t)), + Eq(w(t), C4*exp(5*t) + C5*t*exp(5*t)), + Eq(u(t), C5*exp(5*t))] + assert dsolve(eqs8) == sol8 + assert checksysodesol(eqs8, sol8) == (True, [0, 0, 0, 0, 0]) + + # Regression test case for issue #15574 + # https://github.com/sympy/sympy/issues/15574 + eq9 = [Eq(Derivative(x(t), t), x(t)), Eq(Derivative(y(t), t), y(t)), Eq(Derivative(z(t), t), z(t))] + sol9 = [Eq(x(t), C1*exp(t)), Eq(y(t), C2*exp(t)), Eq(z(t), C3*exp(t))] + assert dsolve(eq9) == sol9 + assert checksysodesol(eq9, sol9) == (True, [0, 0, 0]) + + # Regression test case for issue #15407 + # https://github.com/sympy/sympy/issues/15407 + eqs10 = [Eq(Derivative(x(t), t), (-a_b - a_c)*x(t)), + Eq(Derivative(y(t), t), a_b*y(t)), + Eq(Derivative(z(t), t), a_c*x(t))] + sol10 = [Eq(x(t), -C1*(a_b + a_c)*exp(-t*(a_b + a_c))/a_c), + Eq(y(t), C2*exp(a_b*t)), + Eq(z(t), C1*exp(-t*(a_b + a_c)) + C3)] + assert dsolve(eqs10) == sol10 + assert checksysodesol(eqs10, sol10) == (True, [0, 0, 0]) + + # Regression test case for issue #14312 + # https://github.com/sympy/sympy/issues/14312 + eqs11 = [Eq(Derivative(x(t), t), k3*y(t)), + Eq(Derivative(y(t), t), (-k2 - k3)*y(t)), + Eq(Derivative(z(t), t), k2*y(t))] + sol11 = [Eq(x(t), C1 + C2*k3*exp(-t*(k2 + k3))/k2), + Eq(y(t), -C2*(k2 + k3)*exp(-t*(k2 + k3))/k2), + Eq(z(t), C2*exp(-t*(k2 + k3)) + C3)] + assert dsolve(eqs11) == sol11 + assert checksysodesol(eqs11, sol11) == (True, [0, 0, 0]) + + # Regression test case for issue #14312 + # https://github.com/sympy/sympy/issues/14312 + eqs12 = [Eq(Derivative(z(t), t), k2*y(t)), + Eq(Derivative(x(t), t), k3*y(t)), + Eq(Derivative(y(t), t), (-k2 - k3)*y(t))] + sol12 = [Eq(z(t), C1 - C2*k2*exp(-t*(k2 + k3))/(k2 + k3)), + Eq(x(t), -C2*k3*exp(-t*(k2 + k3))/(k2 + k3) + C3), + Eq(y(t), C2*exp(-t*(k2 + k3)))] + assert dsolve(eqs12) == sol12 + assert checksysodesol(eqs12, sol12) == (True, [0, 0, 0]) + + f, g, h = symbols('f, g, h', cls=Function) + a, b, c = symbols('a, b, c') + + # Regression test case for issue #15474 + # https://github.com/sympy/sympy/issues/15474 + eqs13 = [Eq(Derivative(f(t), t), 2*f(t) + g(t)), + Eq(Derivative(g(t), t), a*f(t))] + sol13 = [Eq(f(t), C1*exp(t*(sqrt(a + 1) + 1))/(sqrt(a + 1) - 1) - C2*exp(-t*(sqrt(a + 1) - 1))/(sqrt(a + 1) + + 1)), + Eq(g(t), C1*exp(t*(sqrt(a + 1) + 1)) + C2*exp(-t*(sqrt(a + 1) - 1)))] + assert dsolve(eqs13) == sol13 + assert checksysodesol(eqs13, sol13) == (True, [0, 0]) + + eqs14 = [Eq(Derivative(f(t), t), 2*g(t) - 3*h(t)), + Eq(Derivative(g(t), t), -2*f(t) + 4*h(t)), + Eq(Derivative(h(t), t), 3*f(t) - 4*g(t))] + sol14 = [Eq(f(t), 2*C1 - sin(sqrt(29)*t)*(sqrt(29)*C2*Rational(3, 25) + C3*Rational(-8, 25)) - + cos(sqrt(29)*t)*(C2*Rational(8, 25) + sqrt(29)*C3*Rational(3, 25))), + Eq(g(t), C1*Rational(3, 2) + sin(sqrt(29)*t)*(sqrt(29)*C2*Rational(4, 25) + C3*Rational(6, 25)) - + cos(sqrt(29)*t)*(C2*Rational(6, 25) + sqrt(29)*C3*Rational(-4, 25))), + Eq(h(t), C1 + C2*cos(sqrt(29)*t) - C3*sin(sqrt(29)*t))] + assert dsolve(eqs14) == sol14 + assert checksysodesol(eqs14, sol14) == (True, [0, 0, 0]) + + eqs15 = [Eq(2*Derivative(f(t), t), 12*g(t) - 12*h(t)), + Eq(3*Derivative(g(t), t), -8*f(t) + 8*h(t)), + Eq(4*Derivative(h(t), t), 6*f(t) - 6*g(t))] + sol15 = [Eq(f(t), C1 - sin(sqrt(29)*t)*(sqrt(29)*C2*Rational(6, 13) + C3*Rational(-16, 13)) - + cos(sqrt(29)*t)*(C2*Rational(16, 13) + sqrt(29)*C3*Rational(6, 13))), + Eq(g(t), C1 + sin(sqrt(29)*t)*(sqrt(29)*C2*Rational(8, 39) + C3*Rational(16, 13)) - + cos(sqrt(29)*t)*(C2*Rational(16, 13) + sqrt(29)*C3*Rational(-8, 39))), + Eq(h(t), C1 + C2*cos(sqrt(29)*t) - C3*sin(sqrt(29)*t))] + assert dsolve(eqs15) == sol15 + assert checksysodesol(eqs15, sol15) == (True, [0, 0, 0]) + + eq16 = (Eq(diff(x(t), t), 21*x(t)), Eq(diff(y(t), t), 17*x(t) + 3*y(t)), + Eq(diff(z(t), t), 5*x(t) + 7*y(t) + 9*z(t))) + sol16 = [Eq(x(t), 216*C1*exp(21*t)/209), + Eq(y(t), 204*C1*exp(21*t)/209 - 6*C2*exp(3*t)/7), + Eq(z(t), C1*exp(21*t) + C2*exp(3*t) + C3*exp(9*t))] + assert dsolve(eq16) == sol16 + assert checksysodesol(eq16, sol16) == (True, [0, 0, 0]) + + eqs17 = [Eq(Derivative(x(t), t), 3*y(t) - 11*z(t)), + Eq(Derivative(y(t), t), -3*x(t) + 7*z(t)), + Eq(Derivative(z(t), t), 11*x(t) - 7*y(t))] + sol17 = [Eq(x(t), C1*Rational(7, 3) - sin(sqrt(179)*t)*(sqrt(179)*C2*Rational(11, 170) + C3*Rational(-21, + 170)) - cos(sqrt(179)*t)*(C2*Rational(21, 170) + sqrt(179)*C3*Rational(11, 170))), + Eq(y(t), C1*Rational(11, 3) + sin(sqrt(179)*t)*(sqrt(179)*C2*Rational(7, 170) + C3*Rational(33, + 170)) - cos(sqrt(179)*t)*(C2*Rational(33, 170) + sqrt(179)*C3*Rational(-7, 170))), + Eq(z(t), C1 + C2*cos(sqrt(179)*t) - C3*sin(sqrt(179)*t))] + assert dsolve(eqs17) == sol17 + assert checksysodesol(eqs17, sol17) == (True, [0, 0, 0]) + + eqs18 = [Eq(3*Derivative(x(t), t), 20*y(t) - 20*z(t)), + Eq(4*Derivative(y(t), t), -15*x(t) + 15*z(t)), + Eq(5*Derivative(z(t), t), 12*x(t) - 12*y(t))] + sol18 = [Eq(x(t), C1 - sin(5*sqrt(2)*t)*(sqrt(2)*C2*Rational(4, 3) - C3) - cos(5*sqrt(2)*t)*(C2 + + sqrt(2)*C3*Rational(4, 3))), + Eq(y(t), C1 + sin(5*sqrt(2)*t)*(sqrt(2)*C2*Rational(3, 4) + C3) - cos(5*sqrt(2)*t)*(C2 + + sqrt(2)*C3*Rational(-3, 4))), + Eq(z(t), C1 + C2*cos(5*sqrt(2)*t) - C3*sin(5*sqrt(2)*t))] + assert dsolve(eqs18) == sol18 + assert checksysodesol(eqs18, sol18) == (True, [0, 0, 0]) + + eqs19 = [Eq(Derivative(x(t), t), 4*x(t) - z(t)), + Eq(Derivative(y(t), t), 2*x(t) + 2*y(t) - z(t)), + Eq(Derivative(z(t), t), 3*x(t) + y(t))] + sol19 = [Eq(x(t), C2*t**2*exp(2*t)/2 + t*(2*C2 + C3)*exp(2*t) + (C1 + C2 + 2*C3)*exp(2*t)), + Eq(y(t), C2*t**2*exp(2*t)/2 + t*(2*C2 + C3)*exp(2*t) + (C1 + 2*C3)*exp(2*t)), + Eq(z(t), C2*t**2*exp(2*t) + t*(3*C2 + 2*C3)*exp(2*t) + (2*C1 + 3*C3)*exp(2*t))] + assert dsolve(eqs19) == sol19 + assert checksysodesol(eqs19, sol19) == (True, [0, 0, 0]) + + eqs20 = [Eq(Derivative(x(t), t), 4*x(t) - y(t) - 2*z(t)), + Eq(Derivative(y(t), t), 2*x(t) + y(t) - 2*z(t)), + Eq(Derivative(z(t), t), 5*x(t) - 3*z(t))] + sol20 = [Eq(x(t), C1*exp(2*t) - sin(t)*(C2*Rational(3, 5) + C3/5) - cos(t)*(C2/5 + C3*Rational(-3, 5))), + Eq(y(t), -sin(t)*(C2*Rational(3, 5) + C3/5) - cos(t)*(C2/5 + C3*Rational(-3, 5))), + Eq(z(t), C1*exp(2*t) - C2*sin(t) + C3*cos(t))] + assert dsolve(eqs20) == sol20 + assert checksysodesol(eqs20, sol20) == (True, [0, 0, 0]) + + eq21 = (Eq(diff(x(t), t), 9*y(t)), Eq(diff(y(t), t), 12*x(t))) + sol21 = [Eq(x(t), -sqrt(3)*C1*exp(-6*sqrt(3)*t)/2 + sqrt(3)*C2*exp(6*sqrt(3)*t)/2), + Eq(y(t), C1*exp(-6*sqrt(3)*t) + C2*exp(6*sqrt(3)*t))] + + assert dsolve(eq21) == sol21 + assert checksysodesol(eq21, sol21) == (True, [0, 0]) + + eqs22 = [Eq(Derivative(x(t), t), 2*x(t) + 4*y(t)), + Eq(Derivative(y(t), t), 12*x(t) + 41*y(t))] + sol22 = [Eq(x(t), C1*(39 - sqrt(1713))*exp(t*(sqrt(1713) + 43)/2)*Rational(-1, 24) + C2*(39 + + sqrt(1713))*exp(t*(43 - sqrt(1713))/2)*Rational(-1, 24)), + Eq(y(t), C1*exp(t*(sqrt(1713) + 43)/2) + C2*exp(t*(43 - sqrt(1713))/2))] + assert dsolve(eqs22) == sol22 + assert checksysodesol(eqs22, sol22) == (True, [0, 0]) + + eqs23 = [Eq(Derivative(x(t), t), x(t) + y(t)), + Eq(Derivative(y(t), t), -2*x(t) + 2*y(t))] + sol23 = [Eq(x(t), (C1/4 + sqrt(7)*C2/4)*cos(sqrt(7)*t/2)*exp(t*Rational(3, 2)) + + sin(sqrt(7)*t/2)*(sqrt(7)*C1/4 + C2*Rational(-1, 4))*exp(t*Rational(3, 2))), + Eq(y(t), C1*cos(sqrt(7)*t/2)*exp(t*Rational(3, 2)) - C2*sin(sqrt(7)*t/2)*exp(t*Rational(3, 2)))] + assert dsolve(eqs23) == sol23 + assert checksysodesol(eqs23, sol23) == (True, [0, 0]) + + # Regression test case for issue #15474 + # https://github.com/sympy/sympy/issues/15474 + a = Symbol("a", real=True) + eq24 = [x(t).diff(t) - a*y(t), y(t).diff(t) + a*x(t)] + sol24 = [Eq(x(t), C1*sin(a*t) + C2*cos(a*t)), Eq(y(t), C1*cos(a*t) - C2*sin(a*t))] + assert dsolve(eq24) == sol24 + assert checksysodesol(eq24, sol24) == (True, [0, 0]) + + # Regression test case for issue #19150 + # https://github.com/sympy/sympy/issues/19150 + eqs25 = [Eq(Derivative(f(t), t), 0), + Eq(Derivative(g(t), t), (f(t) - 2*g(t) + x(t))/(b*c)), + Eq(Derivative(x(t), t), (g(t) - 2*x(t) + y(t))/(b*c)), + Eq(Derivative(y(t), t), (h(t) + x(t) - 2*y(t))/(b*c)), + Eq(Derivative(h(t), t), 0)] + sol25 = [Eq(f(t), -3*C1 + 4*C2), + Eq(g(t), -2*C1 + 3*C2 - C3*exp(-2*t/(b*c)) + C4*exp(-t*(sqrt(2) + 2)/(b*c)) + C5*exp(-t*(2 - + sqrt(2))/(b*c))), + Eq(x(t), -C1 + 2*C2 - sqrt(2)*C4*exp(-t*(sqrt(2) + 2)/(b*c)) + sqrt(2)*C5*exp(-t*(2 - + sqrt(2))/(b*c))), + Eq(y(t), C2 + C3*exp(-2*t/(b*c)) + C4*exp(-t*(sqrt(2) + 2)/(b*c)) + C5*exp(-t*(2 - sqrt(2))/(b*c))), + Eq(h(t), C1)] + assert dsolve(eqs25) == sol25 + assert checksysodesol(eqs25, sol25) == (True, [0, 0, 0, 0, 0]) + + eq26 = [Eq(Derivative(f(t), t), 2*f(t)), Eq(Derivative(g(t), t), 3*f(t) + 7*g(t))] + sol26 = [Eq(f(t), -5*C1*exp(2*t)/3), Eq(g(t), C1*exp(2*t) + C2*exp(7*t))] + assert dsolve(eq26) == sol26 + assert checksysodesol(eq26, sol26) == (True, [0, 0]) + + eq27 = [Eq(Derivative(f(t), t), -9*I*f(t) - 4*g(t)), Eq(Derivative(g(t), t), -4*I*g(t))] + sol27 = [Eq(f(t), 4*I*C1*exp(-4*I*t)/5 + C2*exp(-9*I*t)), Eq(g(t), C1*exp(-4*I*t))] + assert dsolve(eq27) == sol27 + assert checksysodesol(eq27, sol27) == (True, [0, 0]) + + eq28 = [Eq(Derivative(f(t), t), -9*I*f(t)), Eq(Derivative(g(t), t), -4*I*g(t))] + sol28 = [Eq(f(t), C1*exp(-9*I*t)), Eq(g(t), C2*exp(-4*I*t))] + assert dsolve(eq28) == sol28 + assert checksysodesol(eq28, sol28) == (True, [0, 0]) + + eq29 = [Eq(Derivative(f(t), t), 0), Eq(Derivative(g(t), t), 0)] + sol29 = [Eq(f(t), C1), Eq(g(t), C2)] + assert dsolve(eq29) == sol29 + assert checksysodesol(eq29, sol29) == (True, [0, 0]) + + eq30 = [Eq(Derivative(f(t), t), f(t)), Eq(Derivative(g(t), t), 0)] + sol30 = [Eq(f(t), C1*exp(t)), Eq(g(t), C2)] + assert dsolve(eq30) == sol30 + assert checksysodesol(eq30, sol30) == (True, [0, 0]) + + eq31 = [Eq(Derivative(f(t), t), g(t)), Eq(Derivative(g(t), t), 0)] + sol31 = [Eq(f(t), C1 + C2*t), Eq(g(t), C2)] + assert dsolve(eq31) == sol31 + assert checksysodesol(eq31, sol31) == (True, [0, 0]) + + eq32 = [Eq(Derivative(f(t), t), 0), Eq(Derivative(g(t), t), f(t))] + sol32 = [Eq(f(t), C1), Eq(g(t), C1*t + C2)] + assert dsolve(eq32) == sol32 + assert checksysodesol(eq32, sol32) == (True, [0, 0]) + + eq33 = [Eq(Derivative(f(t), t), 0), Eq(Derivative(g(t), t), g(t))] + sol33 = [Eq(f(t), C1), Eq(g(t), C2*exp(t))] + assert dsolve(eq33) == sol33 + assert checksysodesol(eq33, sol33) == (True, [0, 0]) + + eq34 = [Eq(Derivative(f(t), t), f(t)), Eq(Derivative(g(t), t), I*g(t))] + sol34 = [Eq(f(t), C1*exp(t)), Eq(g(t), C2*exp(I*t))] + assert dsolve(eq34) == sol34 + assert checksysodesol(eq34, sol34) == (True, [0, 0]) + + eq35 = [Eq(Derivative(f(t), t), I*f(t)), Eq(Derivative(g(t), t), -I*g(t))] + sol35 = [Eq(f(t), C1*exp(I*t)), Eq(g(t), C2*exp(-I*t))] + assert dsolve(eq35) == sol35 + assert checksysodesol(eq35, sol35) == (True, [0, 0]) + + eq36 = [Eq(Derivative(f(t), t), I*g(t)), Eq(Derivative(g(t), t), 0)] + sol36 = [Eq(f(t), I*C1 + I*C2*t), Eq(g(t), C2)] + assert dsolve(eq36) == sol36 + assert checksysodesol(eq36, sol36) == (True, [0, 0]) + + eq37 = [Eq(Derivative(f(t), t), I*g(t)), Eq(Derivative(g(t), t), I*f(t))] + sol37 = [Eq(f(t), -C1*exp(-I*t) + C2*exp(I*t)), Eq(g(t), C1*exp(-I*t) + C2*exp(I*t))] + assert dsolve(eq37) == sol37 + assert checksysodesol(eq37, sol37) == (True, [0, 0]) + + # Multiple systems + eq1 = [Eq(Derivative(f(t), t)**2, g(t)**2), Eq(-f(t) + Derivative(g(t), t), 0)] + sol1 = [[Eq(f(t), -C1*sin(t) - C2*cos(t)), + Eq(g(t), C1*cos(t) - C2*sin(t))], + [Eq(f(t), -C1*exp(-t) + C2*exp(t)), + Eq(g(t), C1*exp(-t) + C2*exp(t))]] + assert dsolve(eq1) == sol1 + for sol in sol1: + assert checksysodesol(eq1, sol) == (True, [0, 0]) + + +def test_sysode_linear_neq_order1_type2(): + + f, g, h, k = symbols('f g h k', cls=Function) + x, t, a, b, c, d, y = symbols('x t a b c d y') + k1, k2 = symbols('k1 k2') + + + eqs1 = [Eq(Derivative(f(x), x), f(x) + g(x) + 5), + Eq(Derivative(g(x), x), -f(x) - g(x) + 7)] + sol1 = [Eq(f(x), C1 + C2 + 6*x**2 + x*(C2 + 5)), + Eq(g(x), -C1 - 6*x**2 - x*(C2 - 7))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + eqs2 = [Eq(Derivative(f(x), x), f(x) + g(x) + 5), + Eq(Derivative(g(x), x), f(x) + g(x) + 7)] + sol2 = [Eq(f(x), -C1 + C2*exp(2*x) - x - 3), + Eq(g(x), C1 + C2*exp(2*x) + x - 3)] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + eqs3 = [Eq(Derivative(f(x), x), f(x) + 5), + Eq(Derivative(g(x), x), f(x) + 7)] + sol3 = [Eq(f(x), C1*exp(x) - 5), + Eq(g(x), C1*exp(x) + C2 + 2*x - 5)] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0]) + + eqs4 = [Eq(Derivative(f(x), x), f(x) + exp(x)), + Eq(Derivative(g(x), x), x*exp(x) + f(x) + g(x))] + sol4 = [Eq(f(x), C1*exp(x) + x*exp(x)), + Eq(g(x), C1*x*exp(x) + C2*exp(x) + x**2*exp(x))] + assert dsolve(eqs4) == sol4 + assert checksysodesol(eqs4, sol4) == (True, [0, 0]) + + eqs5 = [Eq(Derivative(f(x), x), 5*x + f(x) + g(x)), + Eq(Derivative(g(x), x), f(x) - g(x))] + sol5 = [Eq(f(x), C1*(1 + sqrt(2))*exp(sqrt(2)*x) + C2*(1 - sqrt(2))*exp(-sqrt(2)*x) + x*Rational(-5, 2) + + Rational(-5, 2)), + Eq(g(x), C1*exp(sqrt(2)*x) + C2*exp(-sqrt(2)*x) + x*Rational(-5, 2))] + assert dsolve(eqs5) == sol5 + assert checksysodesol(eqs5, sol5) == (True, [0, 0]) + + eqs6 = [Eq(Derivative(f(x), x), -9*f(x) - 4*g(x)), + Eq(Derivative(g(x), x), -4*g(x)), + Eq(Derivative(h(x), x), h(x) + exp(x))] + sol6 = [Eq(f(x), C2*exp(-4*x)*Rational(-4, 5) + C1*exp(-9*x)), + Eq(g(x), C2*exp(-4*x)), + Eq(h(x), C3*exp(x) + x*exp(x))] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0, 0]) + + # Regression test case for issue #8859 + # https://github.com/sympy/sympy/issues/8859 + eqs7 = [Eq(Derivative(f(t), t), 3*t + f(t)), + Eq(Derivative(g(t), t), g(t))] + sol7 = [Eq(f(t), C1*exp(t) - 3*t - 3), + Eq(g(t), C2*exp(t))] + assert dsolve(eqs7) == sol7 + assert checksysodesol(eqs7, sol7) == (True, [0, 0]) + + # Regression test case for issue #8567 + # https://github.com/sympy/sympy/issues/8567 + eqs8 = [Eq(Derivative(f(t), t), f(t) + 2*g(t)), + Eq(Derivative(g(t), t), -2*f(t) + g(t) + 2*exp(t))] + sol8 = [Eq(f(t), C1*exp(t)*sin(2*t) + C2*exp(t)*cos(2*t) + + exp(t)*sin(2*t)**2 + exp(t)*cos(2*t)**2), + Eq(g(t), C1*exp(t)*cos(2*t) - C2*exp(t)*sin(2*t))] + assert dsolve(eqs8) == sol8 + assert checksysodesol(eqs8, sol8) == (True, [0, 0]) + + # Regression test case for issue #19150 + # https://github.com/sympy/sympy/issues/19150 + eqs9 = [Eq(Derivative(f(t), t), (c - 2*f(t) + g(t))/(a*b)), + Eq(Derivative(g(t), t), (f(t) - 2*g(t) + h(t))/(a*b)), + Eq(Derivative(h(t), t), (d + g(t) - 2*h(t))/(a*b))] + sol9 = [Eq(f(t), -C1*exp(-2*t/(a*b)) + C2*exp(-t*(sqrt(2) + 2)/(a*b)) + C3*exp(-t*(2 - sqrt(2))/(a*b)) + + Mul(Rational(1, 4), 3*c + d, evaluate=False)), + Eq(g(t), -sqrt(2)*C2*exp(-t*(sqrt(2) + 2)/(a*b)) + sqrt(2)*C3*exp(-t*(2 - sqrt(2))/(a*b)) + + Mul(Rational(1, 2), c + d, evaluate=False)), + Eq(h(t), C1*exp(-2*t/(a*b)) + C2*exp(-t*(sqrt(2) + 2)/(a*b)) + C3*exp(-t*(2 - sqrt(2))/(a*b)) + + Mul(Rational(1, 4), c + 3*d, evaluate=False))] + assert dsolve(eqs9) == sol9 + assert checksysodesol(eqs9, sol9) == (True, [0, 0, 0]) + + # Regression test case for issue #16635 + # https://github.com/sympy/sympy/issues/16635 + eqs10 = [Eq(Derivative(f(t), t), 15*t + f(t) - g(t) - 10), + Eq(Derivative(g(t), t), -15*t + f(t) - g(t) - 5)] + sol10 = [Eq(f(t), C1 + C2 + 5*t**3 + 5*t**2 + t*(C2 - 10)), + Eq(g(t), C1 + 5*t**3 - 10*t**2 + t*(C2 - 5))] + assert dsolve(eqs10) == sol10 + assert checksysodesol(eqs10, sol10) == (True, [0, 0]) + + # Multiple solutions + eqs11 = [Eq(Derivative(f(t), t)**2 - 2*Derivative(f(t), t) + 1, 4), + Eq(-y*f(t) + Derivative(g(t), t), 0)] + sol11 = [[Eq(f(t), C1 - t), Eq(g(t), C1*t*y + C2*y + t**2*y*Rational(-1, 2))], + [Eq(f(t), C1 + 3*t), Eq(g(t), C1*t*y + C2*y + t**2*y*Rational(3, 2))]] + assert dsolve(eqs11) == sol11 + for s11 in sol11: + assert checksysodesol(eqs11, s11) == (True, [0, 0]) + + # test case for issue #19831 + # https://github.com/sympy/sympy/issues/19831 + n = symbols('n', positive=True) + x0 = symbols('x_0') + t0 = symbols('t_0') + x_0 = symbols('x_0') + t_0 = symbols('t_0') + t = symbols('t') + x = Function('x') + y = Function('y') + T = symbols('T') + + eqs12 = [Eq(Derivative(y(t), t), x(t)), + Eq(Derivative(x(t), t), n*(y(t) + 1))] + sol12 = [Eq(y(t), C1*exp(sqrt(n)*t)*n**Rational(-1, 2) - C2*exp(-sqrt(n)*t)*n**Rational(-1, 2) - 1), + Eq(x(t), C1*exp(sqrt(n)*t) + C2*exp(-sqrt(n)*t))] + assert dsolve(eqs12) == sol12 + assert checksysodesol(eqs12, sol12) == (True, [0, 0]) + + sol12b = [ + Eq(y(t), (T*exp(-sqrt(n)*t_0)/2 + exp(-sqrt(n)*t_0)/2 + + x_0*exp(-sqrt(n)*t_0)/(2*sqrt(n)))*exp(sqrt(n)*t) + + (T*exp(sqrt(n)*t_0)/2 + exp(sqrt(n)*t_0)/2 - + x_0*exp(sqrt(n)*t_0)/(2*sqrt(n)))*exp(-sqrt(n)*t) - 1), + Eq(x(t), (T*sqrt(n)*exp(-sqrt(n)*t_0)/2 + sqrt(n)*exp(-sqrt(n)*t_0)/2 + + x_0*exp(-sqrt(n)*t_0)/2)*exp(sqrt(n)*t) + - (T*sqrt(n)*exp(sqrt(n)*t_0)/2 + sqrt(n)*exp(sqrt(n)*t_0)/2 - + x_0*exp(sqrt(n)*t_0)/2)*exp(-sqrt(n)*t)) + ] + assert dsolve(eqs12, ics={y(t0): T, x(t0): x0}) == sol12b + assert checksysodesol(eqs12, sol12b) == (True, [0, 0]) + + #Test cases added for the issue 19763 + #https://github.com/sympy/sympy/issues/19763 + + eq13 = [Eq(Derivative(f(t), t), f(t) + g(t) + 9), + Eq(Derivative(g(t), t), 2*f(t) + 5*g(t) + 23)] + sol13 = [Eq(f(t), -C1*(2 + sqrt(6))*exp(t*(3 - sqrt(6)))/2 - C2*(2 - sqrt(6))*exp(t*(sqrt(6) + 3))/2 - + Rational(22,3)), + Eq(g(t), C1*exp(t*(3 - sqrt(6))) + C2*exp(t*(sqrt(6) + 3)) - Rational(5,3))] + assert dsolve(eq13) == sol13 + assert checksysodesol(eq13, sol13) == (True, [0, 0]) + + eq14 = [Eq(Derivative(f(t), t), f(t) + g(t) + 81), + Eq(Derivative(g(t), t), -2*f(t) + g(t) + 23)] + sol14 = [Eq(f(t), sqrt(2)*C1*exp(t)*sin(sqrt(2)*t)/2 + + sqrt(2)*C2*exp(t)*cos(sqrt(2)*t)/2 + - 58*sin(sqrt(2)*t)**2/3 - 58*cos(sqrt(2)*t)**2/3), + Eq(g(t), C1*exp(t)*cos(sqrt(2)*t) - C2*exp(t)*sin(sqrt(2)*t) + - 185*sin(sqrt(2)*t)**2/3 - 185*cos(sqrt(2)*t)**2/3)] + assert dsolve(eq14) == sol14 + assert checksysodesol(eq14, sol14) == (True, [0,0]) + + eq15 = [Eq(Derivative(f(t), t), f(t) + 2*g(t) + k1), + Eq(Derivative(g(t), t), 3*f(t) + 4*g(t) + k2)] + sol15 = [Eq(f(t), -C1*(3 - sqrt(33))*exp(t*(5 + sqrt(33))/2)/6 - + C2*(3 + sqrt(33))*exp(t*(5 - sqrt(33))/2)/6 + 2*k1 - k2), + Eq(g(t), C1*exp(t*(5 + sqrt(33))/2) + C2*exp(t*(5 - sqrt(33))/2) - + Mul(Rational(1,2), 3*k1 - k2, evaluate = False))] + assert dsolve(eq15) == sol15 + assert checksysodesol(eq15, sol15) == (True, [0,0]) + + eq16 = [Eq(Derivative(f(t), t), k1), + Eq(Derivative(g(t), t), k2)] + sol16 = [Eq(f(t), C1 + k1*t), + Eq(g(t), C2 + k2*t)] + assert dsolve(eq16) == sol16 + assert checksysodesol(eq16, sol16) == (True, [0,0]) + + eq17 = [Eq(Derivative(f(t), t), 0), + Eq(Derivative(g(t), t), c*f(t) + k2)] + sol17 = [Eq(f(t), C1), + Eq(g(t), C2*c + t*(C1*c + k2))] + assert dsolve(eq17) == sol17 + assert checksysodesol(eq17 , sol17) == (True , [0,0]) + + eq18 = [Eq(Derivative(f(t), t), k1), + Eq(Derivative(g(t), t), f(t) + k2)] + sol18 = [Eq(f(t), C1 + k1*t), + Eq(g(t), C2 + k1*t**2/2 + t*(C1 + k2))] + assert dsolve(eq18) == sol18 + assert checksysodesol(eq18 , sol18) == (True , [0,0]) + + eq19 = [Eq(Derivative(f(t), t), k1), + Eq(Derivative(g(t), t), f(t) + 2*g(t) + k2)] + sol19 = [Eq(f(t), -2*C1 + k1*t), + Eq(g(t), C1 + C2*exp(2*t) - k1*t/2 - Mul(Rational(1,4), k1 + 2*k2 , evaluate = False))] + assert dsolve(eq19) == sol19 + assert checksysodesol(eq19 , sol19) == (True , [0,0]) + + eq20 = [Eq(diff(f(t), t), f(t) + k1), + Eq(diff(g(t), t), k2)] + sol20 = [Eq(f(t), C1*exp(t) - k1), + Eq(g(t), C2 + k2*t)] + assert dsolve(eq20) == sol20 + assert checksysodesol(eq20 , sol20) == (True , [0,0]) + + eq21 = [Eq(diff(f(t), t), g(t) + k1), + Eq(diff(g(t), t), 0)] + sol21 = [Eq(f(t), C1 + t*(C2 + k1)), + Eq(g(t), C2)] + assert dsolve(eq21) == sol21 + assert checksysodesol(eq21 , sol21) == (True , [0,0]) + + eq22 = [Eq(Derivative(f(t), t), f(t) + 2*g(t) + k1), + Eq(Derivative(g(t), t), k2)] + sol22 = [Eq(f(t), -2*C1 + C2*exp(t) - k1 - 2*k2*t - 2*k2), + Eq(g(t), C1 + k2*t)] + assert dsolve(eq22) == sol22 + assert checksysodesol(eq22 , sol22) == (True , [0,0]) + + eq23 = [Eq(Derivative(f(t), t), g(t) + k1), + Eq(Derivative(g(t), t), 2*g(t) + k2)] + sol23 = [Eq(f(t), C1 + C2*exp(2*t)/2 - k2/4 + t*(2*k1 - k2)/2), + Eq(g(t), C2*exp(2*t) - k2/2)] + assert dsolve(eq23) == sol23 + assert checksysodesol(eq23 , sol23) == (True , [0,0]) + + eq24 = [Eq(Derivative(f(t), t), f(t) + k1), + Eq(Derivative(g(t), t), 2*f(t) + k2)] + sol24 = [Eq(f(t), C1*exp(t)/2 - k1), + Eq(g(t), C1*exp(t) + C2 - 2*k1 - t*(2*k1 - k2))] + assert dsolve(eq24) == sol24 + assert checksysodesol(eq24 , sol24) == (True , [0,0]) + + eq25 = [Eq(Derivative(f(t), t), f(t) + 2*g(t) + k1), + Eq(Derivative(g(t), t), 3*f(t) + 6*g(t) + k2)] + sol25 = [Eq(f(t), -2*C1 + C2*exp(7*t)/3 + 2*t*(3*k1 - k2)/7 - + Mul(Rational(1,49), k1 + 2*k2 , evaluate = False)), + Eq(g(t), C1 + C2*exp(7*t) - t*(3*k1 - k2)/7 - + Mul(Rational(3,49), k1 + 2*k2 , evaluate = False))] + assert dsolve(eq25) == sol25 + assert checksysodesol(eq25 , sol25) == (True , [0,0]) + + eq26 = [Eq(Derivative(f(t), t), 2*f(t) - g(t) + k1), + Eq(Derivative(g(t), t), 4*f(t) - 2*g(t) + 2*k1)] + sol26 = [Eq(f(t), C1 + 2*C2 + t*(2*C1 + k1)), + Eq(g(t), 4*C2 + t*(4*C1 + 2*k1))] + assert dsolve(eq26) == sol26 + assert checksysodesol(eq26 , sol26) == (True , [0,0]) + + # Test Case added for issue #22715 + # https://github.com/sympy/sympy/issues/22715 + + eq27 = [Eq(diff(x(t),t),-1*y(t)+10), Eq(diff(y(t),t),5*x(t)-2*y(t)+3)] + sol27 = [Eq(x(t), (C1/5 - 2*C2/5)*exp(-t)*cos(2*t) + - (2*C1/5 + C2/5)*exp(-t)*sin(2*t) + + 17*sin(2*t)**2/5 + 17*cos(2*t)**2/5), + Eq(y(t), C1*exp(-t)*cos(2*t) - C2*exp(-t)*sin(2*t) + + 10*sin(2*t)**2 + 10*cos(2*t)**2)] + assert dsolve(eq27) == sol27 + assert checksysodesol(eq27 , sol27) == (True , [0,0]) + + +def test_sysode_linear_neq_order1_type3(): + + f, g, h, k, x0 , y0 = symbols('f g h k x0 y0', cls=Function) + x, t, a = symbols('x t a') + r = symbols('r', real=True) + + eqs1 = [Eq(Derivative(f(r), r), r*g(r) + f(r)), + Eq(Derivative(g(r), r), -r*f(r) + g(r))] + sol1 = [Eq(f(r), C1*exp(r)*sin(r**2/2) + C2*exp(r)*cos(r**2/2)), + Eq(g(r), C1*exp(r)*cos(r**2/2) - C2*exp(r)*sin(r**2/2))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + eqs2 = [Eq(Derivative(f(x), x), x**2*g(x) + x*f(x)), + Eq(Derivative(g(x), x), 2*x**2*f(x) + (3*x**2 + x)*g(x))] + sol2 = [Eq(f(x), (sqrt(17)*C1/17 + C2*(17 - 3*sqrt(17))/34)*exp(x**3*(3 + sqrt(17))/6 + x**2/2) - + exp(x**3*(3 - sqrt(17))/6 + x**2/2)*(sqrt(17)*C1/17 + C2*(3*sqrt(17) + 17)*Rational(-1, 34))), + Eq(g(x), exp(x**3*(3 - sqrt(17))/6 + x**2/2)*(C1*(17 - 3*sqrt(17))/34 + sqrt(17)*C2*Rational(-2, + 17)) + exp(x**3*(3 + sqrt(17))/6 + x**2/2)*(C1*(3*sqrt(17) + 17)/34 + sqrt(17)*C2*Rational(2, 17)))] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + eqs3 = [Eq(f(x).diff(x), x*f(x) + g(x)), + Eq(g(x).diff(x), -f(x) + x*g(x))] + sol3 = [Eq(f(x), (C1/2 + I*C2/2)*exp(x**2/2 - I*x) + exp(x**2/2 + I*x)*(C1/2 + I*C2*Rational(-1, 2))), + Eq(g(x), (I*C1/2 + C2/2)*exp(x**2/2 + I*x) - exp(x**2/2 - I*x)*(I*C1/2 + C2*Rational(-1, 2)))] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0]) + + eqs4 = [Eq(f(x).diff(x), x*(f(x) + g(x) + h(x))), Eq(g(x).diff(x), x*(f(x) + g(x) + h(x))), + Eq(h(x).diff(x), x*(f(x) + g(x) + h(x)))] + sol4 = [Eq(f(x), -C1/3 - C2/3 + 2*C3/3 + (C1/3 + C2/3 + C3/3)*exp(3*x**2/2)), + Eq(g(x), 2*C1/3 - C2/3 - C3/3 + (C1/3 + C2/3 + C3/3)*exp(3*x**2/2)), + Eq(h(x), -C1/3 + 2*C2/3 - C3/3 + (C1/3 + C2/3 + C3/3)*exp(3*x**2/2))] + assert dsolve(eqs4) == sol4 + assert checksysodesol(eqs4, sol4) == (True, [0, 0, 0]) + + eqs5 = [Eq(f(x).diff(x), x**2*(f(x) + g(x) + h(x))), Eq(g(x).diff(x), x**2*(f(x) + g(x) + h(x))), + Eq(h(x).diff(x), x**2*(f(x) + g(x) + h(x)))] + sol5 = [Eq(f(x), -C1/3 - C2/3 + 2*C3/3 + (C1/3 + C2/3 + C3/3)*exp(x**3)), + Eq(g(x), 2*C1/3 - C2/3 - C3/3 + (C1/3 + C2/3 + C3/3)*exp(x**3)), + Eq(h(x), -C1/3 + 2*C2/3 - C3/3 + (C1/3 + C2/3 + C3/3)*exp(x**3))] + assert dsolve(eqs5) == sol5 + assert checksysodesol(eqs5, sol5) == (True, [0, 0, 0]) + + eqs6 = [Eq(Derivative(f(x), x), x*(f(x) + g(x) + h(x) + k(x))), + Eq(Derivative(g(x), x), x*(f(x) + g(x) + h(x) + k(x))), + Eq(Derivative(h(x), x), x*(f(x) + g(x) + h(x) + k(x))), + Eq(Derivative(k(x), x), x*(f(x) + g(x) + h(x) + k(x)))] + sol6 = [Eq(f(x), -C1/4 - C2/4 - C3/4 + 3*C4/4 + (C1/4 + C2/4 + C3/4 + C4/4)*exp(2*x**2)), + Eq(g(x), 3*C1/4 - C2/4 - C3/4 - C4/4 + (C1/4 + C2/4 + C3/4 + C4/4)*exp(2*x**2)), + Eq(h(x), -C1/4 + 3*C2/4 - C3/4 - C4/4 + (C1/4 + C2/4 + C3/4 + C4/4)*exp(2*x**2)), + Eq(k(x), -C1/4 - C2/4 + 3*C3/4 - C4/4 + (C1/4 + C2/4 + C3/4 + C4/4)*exp(2*x**2))] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0, 0, 0]) + + y = symbols("y", real=True) + + eqs7 = [Eq(Derivative(f(y), y), y*f(y) + g(y)), + Eq(Derivative(g(y), y), y*g(y) - f(y))] + sol7 = [Eq(f(y), C1*exp(y**2/2)*sin(y) + C2*exp(y**2/2)*cos(y)), + Eq(g(y), C1*exp(y**2/2)*cos(y) - C2*exp(y**2/2)*sin(y))] + assert dsolve(eqs7) == sol7 + assert checksysodesol(eqs7, sol7) == (True, [0, 0]) + + #Test cases added for the issue 19763 + #https://github.com/sympy/sympy/issues/19763 + + eqs8 = [Eq(Derivative(f(t), t), 5*t*f(t) + 2*h(t)), + Eq(Derivative(h(t), t), 2*f(t) + 5*t*h(t))] + sol8 = [Eq(f(t), Mul(-1, (C1/2 - C2/2), evaluate = False)*exp(5*t**2/2 - 2*t) + (C1/2 + C2/2)*exp(5*t**2/2 + 2*t)), + Eq(h(t), (C1/2 - C2/2)*exp(5*t**2/2 - 2*t) + (C1/2 + C2/2)*exp(5*t**2/2 + 2*t))] + assert dsolve(eqs8) == sol8 + assert checksysodesol(eqs8, sol8) == (True, [0, 0]) + + eqs9 = [Eq(diff(f(t), t), 5*t*f(t) + t**2*g(t)), + Eq(diff(g(t), t), -t**2*f(t) + 5*t*g(t))] + sol9 = [Eq(f(t), (C1/2 - I*C2/2)*exp(I*t**3/3 + 5*t**2/2) + (C1/2 + I*C2/2)*exp(-I*t**3/3 + 5*t**2/2)), + Eq(g(t), Mul(-1, (I*C1/2 - C2/2) , evaluate = False)*exp(-I*t**3/3 + 5*t**2/2) + (I*C1/2 + C2/2)*exp(I*t**3/3 + 5*t**2/2))] + assert dsolve(eqs9) == sol9 + assert checksysodesol(eqs9 , sol9) == (True , [0,0]) + + eqs10 = [Eq(diff(f(t), t), t**2*g(t) + 5*t*f(t)), + Eq(diff(g(t), t), -t**2*f(t) + (9*t**2 + 5*t)*g(t))] + sol10 = [Eq(f(t), (C1*(77 - 9*sqrt(77))/154 + sqrt(77)*C2/77)*exp(t**3*(sqrt(77) + 9)/6 + 5*t**2/2) + (C1*(77 + 9*sqrt(77))/154 - sqrt(77)*C2/77)*exp(t**3*(9 - sqrt(77))/6 + 5*t**2/2)), + Eq(g(t), (sqrt(77)*C1/77 + C2*(77 - 9*sqrt(77))/154)*exp(t**3*(9 - sqrt(77))/6 + 5*t**2/2) - (sqrt(77)*C1/77 - C2*(77 + 9*sqrt(77))/154)*exp(t**3*(sqrt(77) + 9)/6 + 5*t**2/2))] + assert dsolve(eqs10) == sol10 + assert checksysodesol(eqs10 , sol10) == (True , [0,0]) + + eqs11 = [Eq(diff(f(t), t), 5*t*f(t) + t**2*g(t)), + Eq(diff(g(t), t), (1-t**2)*f(t) + (5*t + 9*t**2)*g(t))] + sol11 = [Eq(f(t), C1*x0(t) + C2*x0(t)*Integral(t**2*exp(Integral(5*t, t))*exp(Integral(9*t**2 + 5*t, t))/x0(t)**2, t)), + Eq(g(t), C1*y0(t) + C2*(y0(t)*Integral(t**2*exp(Integral(5*t, t))*exp(Integral(9*t**2 + 5*t, t))/x0(t)**2, t) + exp(Integral(5*t, t))*exp(Integral(9*t**2 + 5*t, t))/x0(t)))] + assert dsolve(eqs11) == sol11 + +@slow +def test_sysode_linear_neq_order1_type4(): + + f, g, h, k = symbols('f g h k', cls=Function) + x, t, a = symbols('x t a') + r = symbols('r', real=True) + + eqs1 = [Eq(diff(f(r), r), f(r) + r*g(r) + r**2), Eq(diff(g(r), r), -r*f(r) + g(r) + r)] + sol1 = [Eq(f(r), C1*exp(r)*sin(r**2/2) + C2*exp(r)*cos(r**2/2) + exp(r)*sin(r**2/2)*Integral(r**2*exp(-r)*sin(r**2/2) + + r*exp(-r)*cos(r**2/2), r) + exp(r)*cos(r**2/2)*Integral(r**2*exp(-r)*cos(r**2/2) - r*exp(-r)*sin(r**2/2), r)), + Eq(g(r), C1*exp(r)*cos(r**2/2) - C2*exp(r)*sin(r**2/2) - exp(r)*sin(r**2/2)*Integral(r**2*exp(-r)*cos(r**2/2) - + r*exp(-r)*sin(r**2/2), r) + exp(r)*cos(r**2/2)*Integral(r**2*exp(-r)*sin(r**2/2) + r*exp(-r)*cos(r**2/2), r))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + eqs2 = [Eq(diff(f(r), r), f(r) + r*g(r) + r), Eq(diff(g(r), r), -r*f(r) + g(r) + log(r))] + sol2 = [Eq(f(r), C1*exp(r)*sin(r**2/2) + C2*exp(r)*cos(r**2/2) + exp(r)*sin(r**2/2)*Integral(r*exp(-r)*sin(r**2/2) + + exp(-r)*log(r)*cos(r**2/2), r) + exp(r)*cos(r**2/2)*Integral(r*exp(-r)*cos(r**2/2) - exp(-r)*log(r)*sin( + r**2/2), r)), + Eq(g(r), C1*exp(r)*cos(r**2/2) - C2*exp(r)*sin(r**2/2) - exp(r)*sin(r**2/2)*Integral(r*exp(-r)*cos(r**2/2) - + exp(-r)*log(r)*sin(r**2/2), r) + exp(r)*cos(r**2/2)*Integral(r*exp(-r)*sin(r**2/2) + exp(-r)*log(r)*cos( + r**2/2), r))] + # XXX: dsolve hangs for this in integration + assert dsolve_system(eqs2, simplify=False, doit=False) == [sol2] + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + eqs3 = [Eq(Derivative(f(x), x), x*(f(x) + g(x) + h(x)) + x), + Eq(Derivative(g(x), x), x*(f(x) + g(x) + h(x)) + x), + Eq(Derivative(h(x), x), x*(f(x) + g(x) + h(x)) + 1)] + sol3 = [Eq(f(x), C1*Rational(-1, 3) + C2*Rational(-1, 3) + C3*Rational(2, 3) + x**2/6 + x*Rational(-1, 3) + + (C1/3 + C2/3 + C3/3)*exp(x**2*Rational(3, 2)) + + sqrt(6)*sqrt(pi)*erf(sqrt(6)*x/2)*exp(x**2*Rational(3, 2))/18 + Rational(-2, 9)), + Eq(g(x), C1*Rational(2, 3) + C2*Rational(-1, 3) + C3*Rational(-1, 3) + x**2/6 + x*Rational(-1, 3) + + (C1/3 + C2/3 + C3/3)*exp(x**2*Rational(3, 2)) + + sqrt(6)*sqrt(pi)*erf(sqrt(6)*x/2)*exp(x**2*Rational(3, 2))/18 + Rational(-2, 9)), + Eq(h(x), C1*Rational(-1, 3) + C2*Rational(2, 3) + C3*Rational(-1, 3) + x**2*Rational(-1, 3) + + x*Rational(2, 3) + (C1/3 + C2/3 + C3/3)*exp(x**2*Rational(3, 2)) + + sqrt(6)*sqrt(pi)*erf(sqrt(6)*x/2)*exp(x**2*Rational(3, 2))/18 + Rational(-2, 9))] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0, 0]) + + eqs4 = [Eq(Derivative(f(x), x), x*(f(x) + g(x) + h(x)) + sin(x)), + Eq(Derivative(g(x), x), x*(f(x) + g(x) + h(x)) + sin(x)), + Eq(Derivative(h(x), x), x*(f(x) + g(x) + h(x)) + sin(x))] + sol4 = [Eq(f(x), C1*Rational(-1, 3) + C2*Rational(-1, 3) + C3*Rational(2, 3) + (C1/3 + C2/3 + + C3/3)*exp(x**2*Rational(3, 2)) + Integral(sin(x)*exp(x**2*Rational(-3, 2)), x)*exp(x**2*Rational(3, + 2))), + Eq(g(x), C1*Rational(2, 3) + C2*Rational(-1, 3) + C3*Rational(-1, 3) + (C1/3 + C2/3 + + C3/3)*exp(x**2*Rational(3, 2)) + Integral(sin(x)*exp(x**2*Rational(-3, 2)), x)*exp(x**2*Rational(3, + 2))), + Eq(h(x), C1*Rational(-1, 3) + C2*Rational(2, 3) + C3*Rational(-1, 3) + (C1/3 + C2/3 + + C3/3)*exp(x**2*Rational(3, 2)) + Integral(sin(x)*exp(x**2*Rational(-3, 2)), x)*exp(x**2*Rational(3, + 2)))] + assert dsolve(eqs4) == sol4 + assert checksysodesol(eqs4, sol4) == (True, [0, 0, 0]) + + eqs5 = [Eq(Derivative(f(x), x), x*(f(x) + g(x) + h(x) + k(x) + 1)), + Eq(Derivative(g(x), x), x*(f(x) + g(x) + h(x) + k(x) + 1)), + Eq(Derivative(h(x), x), x*(f(x) + g(x) + h(x) + k(x) + 1)), + Eq(Derivative(k(x), x), x*(f(x) + g(x) + h(x) + k(x) + 1))] + sol5 = [Eq(f(x), C1*Rational(-1, 4) + C2*Rational(-1, 4) + C3*Rational(-1, 4) + C4*Rational(3, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(2*x**2) + Rational(-1, 4)), + Eq(g(x), C1*Rational(3, 4) + C2*Rational(-1, 4) + C3*Rational(-1, 4) + C4*Rational(-1, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(2*x**2) + Rational(-1, 4)), + Eq(h(x), C1*Rational(-1, 4) + C2*Rational(3, 4) + C3*Rational(-1, 4) + C4*Rational(-1, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(2*x**2) + Rational(-1, 4)), + Eq(k(x), C1*Rational(-1, 4) + C2*Rational(-1, 4) + C3*Rational(3, 4) + C4*Rational(-1, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(2*x**2) + Rational(-1, 4))] + assert dsolve(eqs5) == sol5 + assert checksysodesol(eqs5, sol5) == (True, [0, 0, 0, 0]) + + eqs6 = [Eq(Derivative(f(x), x), x**2*(f(x) + g(x) + h(x) + k(x) + 1)), + Eq(Derivative(g(x), x), x**2*(f(x) + g(x) + h(x) + k(x) + 1)), + Eq(Derivative(h(x), x), x**2*(f(x) + g(x) + h(x) + k(x) + 1)), + Eq(Derivative(k(x), x), x**2*(f(x) + g(x) + h(x) + k(x) + 1))] + sol6 = [Eq(f(x), C1*Rational(-1, 4) + C2*Rational(-1, 4) + C3*Rational(-1, 4) + C4*Rational(3, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(x**3*Rational(4, 3)) + Rational(-1, 4)), + Eq(g(x), C1*Rational(3, 4) + C2*Rational(-1, 4) + C3*Rational(-1, 4) + C4*Rational(-1, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(x**3*Rational(4, 3)) + Rational(-1, 4)), + Eq(h(x), C1*Rational(-1, 4) + C2*Rational(3, 4) + C3*Rational(-1, 4) + C4*Rational(-1, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(x**3*Rational(4, 3)) + Rational(-1, 4)), + Eq(k(x), C1*Rational(-1, 4) + C2*Rational(-1, 4) + C3*Rational(3, 4) + C4*Rational(-1, 4) + (C1/4 + + C2/4 + C3/4 + C4/4)*exp(x**3*Rational(4, 3)) + Rational(-1, 4))] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0, 0, 0]) + + eqs7 = [Eq(Derivative(f(x), x), (f(x) + g(x) + h(x))*log(x) + sin(x)), Eq(Derivative(g(x), x), (f(x) + g(x) + + h(x))*log(x) + sin(x)), Eq(Derivative(h(x), x), (f(x) + g(x) + h(x))*log(x) + sin(x))] + sol7 = [Eq(f(x), -C1/3 - C2/3 + 2*C3/3 + (C1/3 + C2/3 + + C3/3)*exp(x*(3*log(x) - 3)) + exp(x*(3*log(x) - + 3))*Integral(exp(3*x)*exp(-3*x*log(x))*sin(x), x)), + Eq(g(x), 2*C1/3 - C2/3 - C3/3 + (C1/3 + C2/3 + + C3/3)*exp(x*(3*log(x) - 3)) + exp(x*(3*log(x) - + 3))*Integral(exp(3*x)*exp(-3*x*log(x))*sin(x), x)), + Eq(h(x), -C1/3 + 2*C2/3 - C3/3 + (C1/3 + C2/3 + + C3/3)*exp(x*(3*log(x) - 3)) + exp(x*(3*log(x) - + 3))*Integral(exp(3*x)*exp(-3*x*log(x))*sin(x), x))] + with dotprodsimp(True): + assert dsolve(eqs7, simplify=False, doit=False) == sol7 + assert checksysodesol(eqs7, sol7) == (True, [0, 0, 0]) + + eqs8 = [Eq(Derivative(f(x), x), (f(x) + g(x) + h(x) + k(x))*log(x) + sin(x)), Eq(Derivative(g(x), x), (f(x) + + g(x) + h(x) + k(x))*log(x) + sin(x)), Eq(Derivative(h(x), x), (f(x) + g(x) + h(x) + k(x))*log(x) + + sin(x)), Eq(Derivative(k(x), x), (f(x) + g(x) + h(x) + k(x))*log(x) + sin(x))] + sol8 = [Eq(f(x), -C1/4 - C2/4 - C3/4 + 3*C4/4 + (C1/4 + C2/4 + C3/4 + + C4/4)*exp(x*(4*log(x) - 4)) + exp(x*(4*log(x) - + 4))*Integral(exp(4*x)*exp(-4*x*log(x))*sin(x), x)), + Eq(g(x), 3*C1/4 - C2/4 - C3/4 - C4/4 + (C1/4 + C2/4 + C3/4 + + C4/4)*exp(x*(4*log(x) - 4)) + exp(x*(4*log(x) - + 4))*Integral(exp(4*x)*exp(-4*x*log(x))*sin(x), x)), + Eq(h(x), -C1/4 + 3*C2/4 - C3/4 - C4/4 + (C1/4 + C2/4 + C3/4 + + C4/4)*exp(x*(4*log(x) - 4)) + exp(x*(4*log(x) - + 4))*Integral(exp(4*x)*exp(-4*x*log(x))*sin(x), x)), + Eq(k(x), -C1/4 - C2/4 + 3*C3/4 - C4/4 + (C1/4 + C2/4 + C3/4 + + C4/4)*exp(x*(4*log(x) - 4)) + exp(x*(4*log(x) - + 4))*Integral(exp(4*x)*exp(-4*x*log(x))*sin(x), x))] + with dotprodsimp(True): + assert dsolve(eqs8) == sol8 + assert checksysodesol(eqs8, sol8) == (True, [0, 0, 0, 0]) + + +def test_sysode_linear_neq_order1_type5_type6(): + f, g = symbols("f g", cls=Function) + x, x_ = symbols("x x_") + + # Type 5 + eqs1 = [Eq(Derivative(f(x), x), (2*f(x) + g(x))/x), Eq(Derivative(g(x), x), (f(x) + 2*g(x))/x)] + sol1 = [Eq(f(x), -C1*x + C2*x**3), Eq(g(x), C1*x + C2*x**3)] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + # Type 6 + eqs2 = [Eq(Derivative(f(x), x), (2*f(x) + g(x) + 1)/x), + Eq(Derivative(g(x), x), (x + f(x) + 2*g(x))/x)] + sol2 = [Eq(f(x), C2*x**3 - x*(C1 + Rational(1, 4)) + x*log(x)*Rational(-1, 2) + Rational(-2, 3)), + Eq(g(x), C2*x**3 + x*log(x)/2 + x*(C1 + Rational(-1, 4)) + Rational(1, 3))] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + +def test_higher_order_to_first_order(): + f, g = symbols('f g', cls=Function) + x = symbols('x') + + eqs1 = [Eq(Derivative(f(x), (x, 2)), 2*f(x) + g(x)), + Eq(Derivative(g(x), (x, 2)), -f(x))] + sol1 = [Eq(f(x), -C2*x*exp(-x) + C3*x*exp(x) - (C1 - C2)*exp(-x) + (C3 + C4)*exp(x)), + Eq(g(x), C2*x*exp(-x) - C3*x*exp(x) + (C1 + C2)*exp(-x) + (C3 - C4)*exp(x))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + eqs2 = [Eq(f(x).diff(x, 2), 0), Eq(g(x).diff(x, 2), f(x))] + sol2 = [Eq(f(x), C1 + C2*x), Eq(g(x), C1*x**2/2 + C2*x**3/6 + C3 + C4*x)] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + eqs3 = [Eq(Derivative(f(x), (x, 2)), 2*f(x)), + Eq(Derivative(g(x), (x, 2)), -f(x) + 2*g(x))] + sol3 = [Eq(f(x), 4*C1*exp(-sqrt(2)*x) + 4*C2*exp(sqrt(2)*x)), + Eq(g(x), sqrt(2)*C1*x*exp(-sqrt(2)*x) - sqrt(2)*C2*x*exp(sqrt(2)*x) + (C1 + + sqrt(2)*C4)*exp(-sqrt(2)*x) + (C2 - sqrt(2)*C3)*exp(sqrt(2)*x))] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0]) + + eqs4 = [Eq(Derivative(f(x), (x, 2)), 2*f(x) + g(x)), + Eq(Derivative(g(x), (x, 2)), 2*g(x))] + sol4 = [Eq(f(x), C1*x*exp(sqrt(2)*x)/4 + C3*x*exp(-sqrt(2)*x)/4 + (C2/4 + sqrt(2)*C3/8)*exp(-sqrt(2)*x) - + exp(sqrt(2)*x)*(sqrt(2)*C1/8 + C4*Rational(-1, 4))), + Eq(g(x), sqrt(2)*C1*exp(sqrt(2)*x)/2 + sqrt(2)*C3*exp(-sqrt(2)*x)*Rational(-1, 2))] + assert dsolve(eqs4) == sol4 + assert checksysodesol(eqs4, sol4) == (True, [0, 0]) + + eqs5 = [Eq(f(x).diff(x, 2), f(x)), Eq(g(x).diff(x, 2), f(x))] + sol5 = [Eq(f(x), -C1*exp(-x) + C2*exp(x)), Eq(g(x), -C1*exp(-x) + C2*exp(x) + C3 + C4*x)] + assert dsolve(eqs5) == sol5 + assert checksysodesol(eqs5, sol5) == (True, [0, 0]) + + eqs6 = [Eq(Derivative(f(x), (x, 2)), f(x) + g(x)), + Eq(Derivative(g(x), (x, 2)), -f(x) - g(x))] + sol6 = [Eq(f(x), C1 + C2*x**2/2 + C2 + C4*x**3/6 + x*(C3 + C4)), + Eq(g(x), -C1 + C2*x**2*Rational(-1, 2) - C3*x + C4*x**3*Rational(-1, 6))] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0]) + + eqs7 = [Eq(Derivative(f(x), (x, 2)), f(x) + g(x) + 1), + Eq(Derivative(g(x), (x, 2)), f(x) + g(x) + 1)] + sol7 = [Eq(f(x), -C1 - C2*x + sqrt(2)*C3*exp(sqrt(2)*x)/2 + sqrt(2)*C4*exp(-sqrt(2)*x)*Rational(-1, 2) + + Rational(-1, 2)), + Eq(g(x), C1 + C2*x + sqrt(2)*C3*exp(sqrt(2)*x)/2 + sqrt(2)*C4*exp(-sqrt(2)*x)*Rational(-1, 2) + + Rational(-1, 2))] + assert dsolve(eqs7) == sol7 + assert checksysodesol(eqs7, sol7) == (True, [0, 0]) + + eqs8 = [Eq(Derivative(f(x), (x, 2)), f(x) + g(x) + 1), + Eq(Derivative(g(x), (x, 2)), -f(x) - g(x) + 1)] + sol8 = [Eq(f(x), C1 + C2 + C4*x**3/6 + x**4/12 + x**2*(C2/2 + Rational(1, 2)) + x*(C3 + C4)), + Eq(g(x), -C1 - C3*x + C4*x**3*Rational(-1, 6) + x**4*Rational(-1, 12) - x**2*(C2/2 + Rational(-1, + 2)))] + assert dsolve(eqs8) == sol8 + assert checksysodesol(eqs8, sol8) == (True, [0, 0]) + + x, y = symbols('x, y', cls=Function) + t, l = symbols('t, l') + + eqs10 = [Eq(Derivative(x(t), (t, 2)), 5*x(t) + 43*y(t)), + Eq(Derivative(y(t), (t, 2)), x(t) + 9*y(t))] + sol10 = [Eq(x(t), C1*(61 - 9*sqrt(47))*sqrt(sqrt(47) + 7)*exp(-t*sqrt(sqrt(47) + 7))/2 + C2*sqrt(7 - + sqrt(47))*(61 + 9*sqrt(47))*exp(-t*sqrt(7 - sqrt(47)))/2 + C3*(61 - 9*sqrt(47))*sqrt(sqrt(47) + + 7)*exp(t*sqrt(sqrt(47) + 7))*Rational(-1, 2) + C4*sqrt(7 - sqrt(47))*(61 + 9*sqrt(47))*exp(t*sqrt(7 + - sqrt(47)))*Rational(-1, 2)), + Eq(y(t), C1*(7 - sqrt(47))*sqrt(sqrt(47) + 7)*exp(-t*sqrt(sqrt(47) + 7))*Rational(-1, 2) + C2*sqrt(7 + - sqrt(47))*(sqrt(47) + 7)*exp(-t*sqrt(7 - sqrt(47)))*Rational(-1, 2) + C3*(7 - + sqrt(47))*sqrt(sqrt(47) + 7)*exp(t*sqrt(sqrt(47) + 7))/2 + C4*sqrt(7 - sqrt(47))*(sqrt(47) + + 7)*exp(t*sqrt(7 - sqrt(47)))/2)] + assert dsolve(eqs10) == sol10 + assert checksysodesol(eqs10, sol10) == (True, [0, 0]) + + eqs11 = [Eq(7*x(t) + Derivative(x(t), (t, 2)) - 9*Derivative(y(t), t), 0), + Eq(7*y(t) + 9*Derivative(x(t), t) + Derivative(y(t), (t, 2)), 0)] + sol11 = [Eq(y(t), C1*(9 - sqrt(109))*sin(sqrt(2)*t*sqrt(9*sqrt(109) + 95)/2)/14 + C2*(9 - + sqrt(109))*cos(sqrt(2)*t*sqrt(9*sqrt(109) + 95)/2)*Rational(-1, 14) + C3*(9 + + sqrt(109))*sin(sqrt(2)*t*sqrt(95 - 9*sqrt(109))/2)/14 + C4*(9 + sqrt(109))*cos(sqrt(2)*t*sqrt(95 - + 9*sqrt(109))/2)*Rational(-1, 14)), + Eq(x(t), C1*(9 - sqrt(109))*cos(sqrt(2)*t*sqrt(9*sqrt(109) + 95)/2)*Rational(-1, 14) + C2*(9 - + sqrt(109))*sin(sqrt(2)*t*sqrt(9*sqrt(109) + 95)/2)*Rational(-1, 14) + C3*(9 + + sqrt(109))*cos(sqrt(2)*t*sqrt(95 - 9*sqrt(109))/2)/14 + C4*(9 + sqrt(109))*sin(sqrt(2)*t*sqrt(95 - + 9*sqrt(109))/2)/14)] + assert dsolve(eqs11) == sol11 + assert checksysodesol(eqs11, sol11) == (True, [0, 0]) + + # Euler Systems + # Note: To add examples of euler systems solver with non-homogeneous term. + eqs13 = [Eq(Derivative(f(t), (t, 2)), Derivative(f(t), t)/t + f(t)/t**2 + g(t)/t**2), + Eq(Derivative(g(t), (t, 2)), g(t)/t**2)] + sol13 = [Eq(f(t), C1*(sqrt(5) + 3)*Rational(-1, 2)*t**(Rational(1, 2) + + sqrt(5)*Rational(-1, 2)) + C2*t**(Rational(1, 2) + + sqrt(5)/2)*(3 - sqrt(5))*Rational(-1, 2) - C3*t**(1 - + sqrt(2))*(1 + sqrt(2)) - C4*t**(1 + sqrt(2))*(1 - sqrt(2))), + Eq(g(t), C1*(1 + sqrt(5))*Rational(-1, 2)*t**(Rational(1, 2) + + sqrt(5)*Rational(-1, 2)) + C2*t**(Rational(1, 2) + + sqrt(5)/2)*(1 - sqrt(5))*Rational(-1, 2))] + assert dsolve(eqs13) == sol13 + assert checksysodesol(eqs13, sol13) == (True, [0, 0]) + + # Solving systems using dsolve separately + eqs14 = [Eq(Derivative(f(t), (t, 2)), t*f(t)), + Eq(Derivative(g(t), (t, 2)), t*g(t))] + sol14 = [Eq(f(t), C1*airyai(t) + C2*airybi(t)), + Eq(g(t), C3*airyai(t) + C4*airybi(t))] + assert dsolve(eqs14) == sol14 + assert checksysodesol(eqs14, sol14) == (True, [0, 0]) + + + eqs15 = [Eq(Derivative(x(t), (t, 2)), t*(4*Derivative(x(t), t) + 8*Derivative(y(t), t))), + Eq(Derivative(y(t), (t, 2)), t*(12*Derivative(x(t), t) - 6*Derivative(y(t), t)))] + sol15 = [Eq(x(t), C1 - erf(sqrt(6)*t)*(sqrt(6)*sqrt(pi)*C2/33 + sqrt(6)*sqrt(pi)*C3*Rational(-1, 44)) + + erfi(sqrt(5)*t)*(sqrt(5)*sqrt(pi)*C2*Rational(2, 55) + sqrt(5)*sqrt(pi)*C3*Rational(4, 55))), + Eq(y(t), C4 + erf(sqrt(6)*t)*(sqrt(6)*sqrt(pi)*C2*Rational(2, 33) + sqrt(6)*sqrt(pi)*C3*Rational(-1, + 22)) + erfi(sqrt(5)*t)*(sqrt(5)*sqrt(pi)*C2*Rational(3, 110) + sqrt(5)*sqrt(pi)*C3*Rational(3, 55)))] + assert dsolve(eqs15) == sol15 + assert checksysodesol(eqs15, sol15) == (True, [0, 0]) + + +@slow +def test_higher_order_to_first_order_9(): + f, g = symbols('f g', cls=Function) + x = symbols('x') + + eqs9 = [f(x) + g(x) - 2*exp(I*x) + 2*Derivative(f(x), x) + Derivative(f(x), (x, 2)), + f(x) + g(x) - 2*exp(I*x) + 2*Derivative(g(x), x) + Derivative(g(x), (x, 2))] + sol9 = [Eq(f(x), -C1 + C4*exp(-2*x)/2 - (C2/2 - C3/2)*exp(-x)*cos(x) + + (C2/2 + C3/2)*exp(-x)*sin(x) + 2*((1 - 2*I)*exp(I*x)*sin(x)**2/5) + + 2*((1 - 2*I)*exp(I*x)*cos(x)**2/5)), + Eq(g(x), C1 - C4*exp(-2*x)/2 - (C2/2 - C3/2)*exp(-x)*cos(x) + + (C2/2 + C3/2)*exp(-x)*sin(x) + 2*((1 - 2*I)*exp(I*x)*sin(x)**2/5) + + 2*((1 - 2*I)*exp(I*x)*cos(x)**2/5))] + assert dsolve(eqs9) == sol9 + assert checksysodesol(eqs9, sol9) == (True, [0, 0]) + + +def test_higher_order_to_first_order_12(): + f, g = symbols('f g', cls=Function) + x = symbols('x') + + x, y = symbols('x, y', cls=Function) + t, l = symbols('t, l') + + eqs12 = [Eq(4*x(t) + Derivative(x(t), (t, 2)) + 8*Derivative(y(t), t), 0), + Eq(4*y(t) - 8*Derivative(x(t), t) + Derivative(y(t), (t, 2)), 0)] + sol12 = [Eq(y(t), C1*(2 - sqrt(5))*sin(2*t*sqrt(4*sqrt(5) + 9))*Rational(-1, 2) + C2*(2 - + sqrt(5))*cos(2*t*sqrt(4*sqrt(5) + 9))/2 + C3*(2 + sqrt(5))*sin(2*t*sqrt(9 - 4*sqrt(5)))*Rational(-1, + 2) + C4*(2 + sqrt(5))*cos(2*t*sqrt(9 - 4*sqrt(5)))/2), + Eq(x(t), C1*(2 - sqrt(5))*cos(2*t*sqrt(4*sqrt(5) + 9))*Rational(-1, 2) + C2*(2 - + sqrt(5))*sin(2*t*sqrt(4*sqrt(5) + 9))*Rational(-1, 2) + C3*(2 + sqrt(5))*cos(2*t*sqrt(9 - + 4*sqrt(5)))/2 + C4*(2 + sqrt(5))*sin(2*t*sqrt(9 - 4*sqrt(5)))/2)] + assert dsolve(eqs12) == sol12 + assert checksysodesol(eqs12, sol12) == (True, [0, 0]) + + +def test_second_order_to_first_order_2(): + f, g = symbols("f g", cls=Function) + x, t, x_, t_, d, a, m = symbols("x t x_ t_ d a m") + + eqs2 = [Eq(f(x).diff(x, 2), 2*(x*g(x).diff(x) - g(x))), + Eq(g(x).diff(x, 2),-2*(x*f(x).diff(x) - f(x)))] + sol2 = [Eq(f(x), C1*x + x*Integral(C2*exp(-x_)*exp(I*exp(2*x_))/2 + C2*exp(-x_)*exp(-I*exp(2*x_))/2 - + I*C3*exp(-x_)*exp(I*exp(2*x_))/2 + I*C3*exp(-x_)*exp(-I*exp(2*x_))/2, (x_, log(x)))), + Eq(g(x), C4*x + x*Integral(I*C2*exp(-x_)*exp(I*exp(2*x_))/2 - I*C2*exp(-x_)*exp(-I*exp(2*x_))/2 + + C3*exp(-x_)*exp(I*exp(2*x_))/2 + C3*exp(-x_)*exp(-I*exp(2*x_))/2, (x_, log(x))))] + # XXX: dsolve hangs for this in integration + assert dsolve_system(eqs2, simplify=False, doit=False) == [sol2] + assert checksysodesol(eqs2, sol2) == (True, [0, 0]) + + eqs3 = (Eq(diff(f(t),t,t), 9*t*diff(g(t),t)-9*g(t)), Eq(diff(g(t),t,t),7*t*diff(f(t),t)-7*f(t))) + sol3 = [Eq(f(t), C1*t + t*Integral(C2*exp(-t_)*exp(3*sqrt(7)*exp(2*t_)/2)/2 + C2*exp(-t_)* + exp(-3*sqrt(7)*exp(2*t_)/2)/2 + 3*sqrt(7)*C3*exp(-t_)*exp(3*sqrt(7)*exp(2*t_)/2)/14 - + 3*sqrt(7)*C3*exp(-t_)*exp(-3*sqrt(7)*exp(2*t_)/2)/14, (t_, log(t)))), + Eq(g(t), C4*t + t*Integral(sqrt(7)*C2*exp(-t_)*exp(3*sqrt(7)*exp(2*t_)/2)/6 - sqrt(7)*C2*exp(-t_)* + exp(-3*sqrt(7)*exp(2*t_)/2)/6 + C3*exp(-t_)*exp(3*sqrt(7)*exp(2*t_)/2)/2 + C3*exp(-t_)*exp(-3*sqrt(7)* + exp(2*t_)/2)/2, (t_, log(t))))] + # XXX: dsolve hangs for this in integration + assert dsolve_system(eqs3, simplify=False, doit=False) == [sol3] + assert checksysodesol(eqs3, sol3) == (True, [0, 0]) + + # Regression Test case for sympy#19238 + # https://github.com/sympy/sympy/issues/19238 + # Note: When the doit method is removed, these particular types of systems + # can be divided first so that we have lesser number of big matrices. + eqs5 = [Eq(Derivative(g(t), (t, 2)), a*m), + Eq(Derivative(f(t), (t, 2)), 0)] + sol5 = [Eq(g(t), C1 + C2*t + a*m*t**2/2), + Eq(f(t), C3 + C4*t)] + assert dsolve(eqs5) == sol5 + assert checksysodesol(eqs5, sol5) == (True, [0, 0]) + + # Type 2 + eqs6 = [Eq(Derivative(f(t), (t, 2)), f(t)/t**4), + Eq(Derivative(g(t), (t, 2)), d*g(t)/t**4)] + sol6 = [Eq(f(t), C1*sqrt(t**2)*exp(-1/t) - C2*sqrt(t**2)*exp(1/t)), + Eq(g(t), C3*sqrt(t**2)*exp(-sqrt(d)/t)*d**Rational(-1, 2) - + C4*sqrt(t**2)*exp(sqrt(d)/t)*d**Rational(-1, 2))] + assert dsolve(eqs6) == sol6 + assert checksysodesol(eqs6, sol6) == (True, [0, 0]) + + +@slow +def test_second_order_to_first_order_slow1(): + f, g = symbols("f g", cls=Function) + x, t, x_, t_, d, a, m = symbols("x t x_ t_ d a m") + + # Type 1 + + eqs1 = [Eq(f(x).diff(x, 2), 2/x *(x*g(x).diff(x) - g(x))), + Eq(g(x).diff(x, 2),-2/x *(x*f(x).diff(x) - f(x)))] + sol1 = [Eq(f(x), C1*x + 2*C2*x*Ci(2*x) - C2*sin(2*x) - 2*C3*x*Si(2*x) - C3*cos(2*x)), + Eq(g(x), -2*C2*x*Si(2*x) - C2*cos(2*x) - 2*C3*x*Ci(2*x) + C3*sin(2*x) + C4*x)] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + +def test_second_order_to_first_order_slow4(): + f, g = symbols("f g", cls=Function) + x, t, x_, t_, d, a, m = symbols("x t x_ t_ d a m") + + eqs4 = [Eq(Derivative(f(t), (t, 2)), t*sin(t)*Derivative(g(t), t) - g(t)*sin(t)), + Eq(Derivative(g(t), (t, 2)), t*sin(t)*Derivative(f(t), t) - f(t)*sin(t))] + sol4 = [Eq(f(t), C1*t + t*Integral(C2*exp(-t_)*exp(exp(t_)*cos(exp(t_)))*exp(-sin(exp(t_)))/2 + + C2*exp(-t_)*exp(-exp(t_)*cos(exp(t_)))*exp(sin(exp(t_)))/2 - C3*exp(-t_)*exp(exp(t_)*cos(exp(t_)))* + exp(-sin(exp(t_)))/2 + + C3*exp(-t_)*exp(-exp(t_)*cos(exp(t_)))*exp(sin(exp(t_)))/2, (t_, log(t)))), + Eq(g(t), C4*t + t*Integral(-C2*exp(-t_)*exp(exp(t_)*cos(exp(t_)))*exp(-sin(exp(t_)))/2 + + C2*exp(-t_)*exp(-exp(t_)*cos(exp(t_)))*exp(sin(exp(t_)))/2 + C3*exp(-t_)*exp(exp(t_)*cos(exp(t_)))* + exp(-sin(exp(t_)))/2 + C3*exp(-t_)*exp(-exp(t_)*cos(exp(t_)))*exp(sin(exp(t_)))/2, (t_, log(t))))] + # XXX: dsolve hangs for this in integration + assert dsolve_system(eqs4, simplify=False, doit=False) == [sol4] + assert checksysodesol(eqs4, sol4) == (True, [0, 0]) + + +def test_component_division(): + f, g, h, k = symbols('f g h k', cls=Function) + x = symbols("x") + funcs = [f(x), g(x), h(x), k(x)] + + eqs1 = [Eq(Derivative(f(x), x), 2*f(x)), + Eq(Derivative(g(x), x), f(x)), + Eq(Derivative(h(x), x), h(x)), + Eq(Derivative(k(x), x), h(x)**4 + k(x))] + sol1 = [Eq(f(x), 2*C1*exp(2*x)), + Eq(g(x), C1*exp(2*x) + C2), + Eq(h(x), C3*exp(x)), + Eq(k(x), C3**4*exp(4*x)/3 + C4*exp(x))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0, 0, 0]) + + components1 = {((Eq(Derivative(f(x), x), 2*f(x)),), (Eq(Derivative(g(x), x), f(x)),)), + ((Eq(Derivative(h(x), x), h(x)),), (Eq(Derivative(k(x), x), h(x)**4 + k(x)),))} + eqsdict1 = ({f(x): set(), g(x): {f(x)}, h(x): set(), k(x): {h(x)}}, + {f(x): Eq(Derivative(f(x), x), 2*f(x)), + g(x): Eq(Derivative(g(x), x), f(x)), + h(x): Eq(Derivative(h(x), x), h(x)), + k(x): Eq(Derivative(k(x), x), h(x)**4 + k(x))}) + graph1 = [{f(x), g(x), h(x), k(x)}, {(g(x), f(x)), (k(x), h(x))}] + assert {tuple(tuple(scc) for scc in wcc) for wcc in _component_division(eqs1, funcs, x)} == components1 + assert _eqs2dict(eqs1, funcs) == eqsdict1 + assert [set(element) for element in _dict2graph(eqsdict1[0])] == graph1 + + eqs2 = [Eq(Derivative(f(x), x), 2*f(x)), + Eq(Derivative(g(x), x), f(x)), + Eq(Derivative(h(x), x), h(x)), + Eq(Derivative(k(x), x), f(x)**4 + k(x))] + sol2 = [Eq(f(x), C1*exp(2*x)), + Eq(g(x), C1*exp(2*x)/2 + C2), + Eq(h(x), C3*exp(x)), + Eq(k(x), C1**4*exp(8*x)/7 + C4*exp(x))] + assert dsolve(eqs2) == sol2 + assert checksysodesol(eqs2, sol2) == (True, [0, 0, 0, 0]) + + components2 = {frozenset([(Eq(Derivative(f(x), x), 2*f(x)),), + (Eq(Derivative(g(x), x), f(x)),), + (Eq(Derivative(k(x), x), f(x)**4 + k(x)),)]), + frozenset([(Eq(Derivative(h(x), x), h(x)),)])} + eqsdict2 = ({f(x): set(), g(x): {f(x)}, h(x): set(), k(x): {f(x)}}, + {f(x): Eq(Derivative(f(x), x), 2*f(x)), + g(x): Eq(Derivative(g(x), x), f(x)), + h(x): Eq(Derivative(h(x), x), h(x)), + k(x): Eq(Derivative(k(x), x), f(x)**4 + k(x))}) + graph2 = [{f(x), g(x), h(x), k(x)}, {(g(x), f(x)), (k(x), f(x))}] + assert {frozenset(tuple(scc) for scc in wcc) for wcc in _component_division(eqs2, funcs, x)} == components2 + assert _eqs2dict(eqs2, funcs) == eqsdict2 + assert [set(element) for element in _dict2graph(eqsdict2[0])] == graph2 + + eqs3 = [Eq(Derivative(f(x), x), 2*f(x)), + Eq(Derivative(g(x), x), x + f(x)), + Eq(Derivative(h(x), x), h(x)), + Eq(Derivative(k(x), x), f(x)**4 + k(x))] + sol3 = [Eq(f(x), C1*exp(2*x)), + Eq(g(x), C1*exp(2*x)/2 + C2 + x**2/2), + Eq(h(x), C3*exp(x)), + Eq(k(x), C1**4*exp(8*x)/7 + C4*exp(x))] + assert dsolve(eqs3) == sol3 + assert checksysodesol(eqs3, sol3) == (True, [0, 0, 0, 0]) + + components3 = {frozenset([(Eq(Derivative(f(x), x), 2*f(x)),), + (Eq(Derivative(g(x), x), x + f(x)),), + (Eq(Derivative(k(x), x), f(x)**4 + k(x)),)]), + frozenset([(Eq(Derivative(h(x), x), h(x)),),])} + eqsdict3 = ({f(x): set(), g(x): {f(x)}, h(x): set(), k(x): {f(x)}}, + {f(x): Eq(Derivative(f(x), x), 2*f(x)), + g(x): Eq(Derivative(g(x), x), x + f(x)), + h(x): Eq(Derivative(h(x), x), h(x)), + k(x): Eq(Derivative(k(x), x), f(x)**4 + k(x))}) + graph3 = [{f(x), g(x), h(x), k(x)}, {(g(x), f(x)), (k(x), f(x))}] + assert {frozenset(tuple(scc) for scc in wcc) for wcc in _component_division(eqs3, funcs, x)} == components3 + assert _eqs2dict(eqs3, funcs) == eqsdict3 + assert [set(l) for l in _dict2graph(eqsdict3[0])] == graph3 + + # Note: To be uncommented when the default option to call dsolve first for + # single ODE system can be rearranged. This can be done after the doit + # option in dsolve is made False by default. + + eqs4 = [Eq(Derivative(f(x), x), x*f(x) + 2*g(x)), + Eq(Derivative(g(x), x), f(x) + x*g(x) + x), + Eq(Derivative(h(x), x), h(x)), + Eq(Derivative(k(x), x), f(x)**4 + k(x))] + sol4 = [Eq(f(x), (C1/2 - sqrt(2)*C2/2 - sqrt(2)*Integral(x*exp(-x**2/2 - sqrt(2)*x)/2 + x*exp(-x**2/2 +\ + sqrt(2)*x)/2, x)/2 + Integral(sqrt(2)*x*exp(-x**2/2 - sqrt(2)*x)/2 - sqrt(2)*x*exp(-x**2/2 +\ + sqrt(2)*x)/2, x)/2)*exp(x**2/2 - sqrt(2)*x) + (C1/2 + sqrt(2)*C2/2 + sqrt(2)*Integral(x*exp(-x**2/2 + - sqrt(2)*x)/2 + x*exp(-x**2/2 + sqrt(2)*x)/2, x)/2 + Integral(sqrt(2)*x*exp(-x**2/2 - sqrt(2)*x)/2 + - sqrt(2)*x*exp(-x**2/2 + sqrt(2)*x)/2, x)/2)*exp(x**2/2 + sqrt(2)*x)), + Eq(g(x), (-sqrt(2)*C1/4 + C2/2 + Integral(x*exp(-x**2/2 - sqrt(2)*x)/2 + x*exp(-x**2/2 + sqrt(2)*x)/2, x)/2 -\ + sqrt(2)*Integral(sqrt(2)*x*exp(-x**2/2 - sqrt(2)*x)/2 - sqrt(2)*x*exp(-x**2/2 + sqrt(2)*x)/2, + x)/4)*exp(x**2/2 - sqrt(2)*x) + (sqrt(2)*C1/4 + C2/2 + Integral(x*exp(-x**2/2 - sqrt(2)*x)/2 + + x*exp(-x**2/2 + sqrt(2)*x)/2, x)/2 + sqrt(2)*Integral(sqrt(2)*x*exp(-x**2/2 - sqrt(2)*x)/2 - + sqrt(2)*x*exp(-x**2/2 + sqrt(2)*x)/2, x)/4)*exp(x**2/2 + sqrt(2)*x)), + Eq(h(x), C3*exp(x)), + Eq(k(x), C4*exp(x) + exp(x)*Integral((C1*exp(x**2/2 - sqrt(2)*x)/2 + C1*exp(x**2/2 + sqrt(2)*x)/2 - + sqrt(2)*C2*exp(x**2/2 - sqrt(2)*x)/2 + sqrt(2)*C2*exp(x**2/2 + sqrt(2)*x)/2 - sqrt(2)*exp(x**2/2 - + sqrt(2)*x)*Integral(x*exp(-x**2/2 - sqrt(2)*x)/2 + x*exp(-x**2/2 + sqrt(2)*x)/2, x)/2 + exp(x**2/2 - + sqrt(2)*x)*Integral(sqrt(2)*x*exp(-x**2/2 - sqrt(2)*x)/2 - sqrt(2)*x*exp(-x**2/2 + sqrt(2)*x)/2, + x)/2 + sqrt(2)*exp(x**2/2 + sqrt(2)*x)*Integral(x*exp(-x**2/2 - sqrt(2)*x)/2 + x*exp(-x**2/2 + + sqrt(2)*x)/2, x)/2 + exp(x**2/2 + sqrt(2)*x)*Integral(sqrt(2)*x*exp(-x**2/2 - sqrt(2)*x)/2 - + sqrt(2)*x*exp(-x**2/2 + sqrt(2)*x)/2, x)/2)**4*exp(-x), x))] + components4 = {(frozenset([Eq(Derivative(f(x), x), x*f(x) + 2*g(x)), + Eq(Derivative(g(x), x), x*g(x) + x + f(x))]), + frozenset([Eq(Derivative(k(x), x), f(x)**4 + k(x)),])), + (frozenset([Eq(Derivative(h(x), x), h(x)),]),)} + eqsdict4 = ({f(x): {g(x)}, g(x): {f(x)}, h(x): set(), k(x): {f(x)}}, + {f(x): Eq(Derivative(f(x), x), x*f(x) + 2*g(x)), + g(x): Eq(Derivative(g(x), x), x*g(x) + x + f(x)), + h(x): Eq(Derivative(h(x), x), h(x)), + k(x): Eq(Derivative(k(x), x), f(x)**4 + k(x))}) + graph4 = [{f(x), g(x), h(x), k(x)}, {(f(x), g(x)), (g(x), f(x)), (k(x), f(x))}] + assert {tuple(frozenset(scc) for scc in wcc) for wcc in _component_division(eqs4, funcs, x)} == components4 + assert _eqs2dict(eqs4, funcs) == eqsdict4 + assert [set(element) for element in _dict2graph(eqsdict4[0])] == graph4 + # XXX: dsolve hangs in integration here: + assert dsolve_system(eqs4, simplify=False, doit=False) == [sol4] + assert checksysodesol(eqs4, sol4) == (True, [0, 0, 0, 0]) + + eqs5 = [Eq(Derivative(f(x), x), x*f(x) + 2*g(x)), + Eq(Derivative(g(x), x), x*g(x) + f(x)), + Eq(Derivative(h(x), x), h(x)), + Eq(Derivative(k(x), x), f(x)**4 + k(x))] + sol5 = [Eq(f(x), (C1/2 - sqrt(2)*C2/2)*exp(x**2/2 - sqrt(2)*x) + (C1/2 + sqrt(2)*C2/2)*exp(x**2/2 + sqrt(2)*x)), + Eq(g(x), (-sqrt(2)*C1/4 + C2/2)*exp(x**2/2 - sqrt(2)*x) + (sqrt(2)*C1/4 + C2/2)*exp(x**2/2 + sqrt(2)*x)), + Eq(h(x), C3*exp(x)), + Eq(k(x), C4*exp(x) + exp(x)*Integral((C1*exp(x**2/2 - sqrt(2)*x)/2 + C1*exp(x**2/2 + sqrt(2)*x)/2 - + sqrt(2)*C2*exp(x**2/2 - sqrt(2)*x)/2 + sqrt(2)*C2*exp(x**2/2 + sqrt(2)*x)/2)**4*exp(-x), x))] + components5 = {(frozenset([Eq(Derivative(f(x), x), x*f(x) + 2*g(x)), + Eq(Derivative(g(x), x), x*g(x) + f(x))]), + frozenset([Eq(Derivative(k(x), x), f(x)**4 + k(x)),])), + (frozenset([Eq(Derivative(h(x), x), h(x)),]),)} + eqsdict5 = ({f(x): {g(x)}, g(x): {f(x)}, h(x): set(), k(x): {f(x)}}, + {f(x): Eq(Derivative(f(x), x), x*f(x) + 2*g(x)), + g(x): Eq(Derivative(g(x), x), x*g(x) + f(x)), + h(x): Eq(Derivative(h(x), x), h(x)), + k(x): Eq(Derivative(k(x), x), f(x)**4 + k(x))}) + graph5 = [{f(x), g(x), h(x), k(x)}, {(f(x), g(x)), (g(x), f(x)), (k(x), f(x))}] + assert {tuple(frozenset(scc) for scc in wcc) for wcc in _component_division(eqs5, funcs, x)} == components5 + assert _eqs2dict(eqs5, funcs) == eqsdict5 + assert [set(element) for element in _dict2graph(eqsdict5[0])] == graph5 + # XXX: dsolve hangs in integration here: + assert dsolve_system(eqs5, simplify=False, doit=False) == [sol5] + assert checksysodesol(eqs5, sol5) == (True, [0, 0, 0, 0]) + + +def test_linodesolve(): + t, x, a = symbols("t x a") + f, g, h = symbols("f g h", cls=Function) + + # Testing the Errors + raises(ValueError, lambda: linodesolve(1, t)) + raises(ValueError, lambda: linodesolve(a, t)) + + A1 = Matrix([[1, 2], [2, 4], [4, 6]]) + raises(NonSquareMatrixError, lambda: linodesolve(A1, t)) + + A2 = Matrix([[1, 2, 1], [3, 1, 2]]) + raises(NonSquareMatrixError, lambda: linodesolve(A2, t)) + + # Testing auto functionality + func = [f(t), g(t)] + eq = [Eq(f(t).diff(t) + g(t).diff(t), g(t)), Eq(g(t).diff(t), f(t))] + ceq = canonical_odes(eq, func, t) + (A1, A0), b = linear_ode_to_matrix(ceq[0], func, t, 1) + A = A0 + sol = [C1*(-Rational(1, 2) + sqrt(5)/2)*exp(t*(-Rational(1, 2) + sqrt(5)/2)) + C2*(-sqrt(5)/2 - Rational(1, 2))* + exp(t*(-sqrt(5)/2 - Rational(1, 2))), + C1*exp(t*(-Rational(1, 2) + sqrt(5)/2)) + C2*exp(t*(-sqrt(5)/2 - Rational(1, 2)))] + assert constant_renumber(linodesolve(A, t), variables=Tuple(*eq).free_symbols) == sol + + # Testing the Errors + raises(ValueError, lambda: linodesolve(1, t, b=Matrix([t+1]))) + raises(ValueError, lambda: linodesolve(a, t, b=Matrix([log(t) + sin(t)]))) + + raises(ValueError, lambda: linodesolve(Matrix([7]), t, b=t**2)) + raises(ValueError, lambda: linodesolve(Matrix([a+10]), t, b=log(t)*cos(t))) + + raises(ValueError, lambda: linodesolve(7, t, b=t**2)) + raises(ValueError, lambda: linodesolve(a, t, b=log(t) + sin(t))) + + A1 = Matrix([[1, 2], [2, 4], [4, 6]]) + b1 = Matrix([t, 1, t**2]) + raises(NonSquareMatrixError, lambda: linodesolve(A1, t, b=b1)) + + A2 = Matrix([[1, 2, 1], [3, 1, 2]]) + b2 = Matrix([t, t**2]) + raises(NonSquareMatrixError, lambda: linodesolve(A2, t, b=b2)) + + raises(ValueError, lambda: linodesolve(A1[:2, :], t, b=b1)) + raises(ValueError, lambda: linodesolve(A1[:2, :], t, b=b1[:1])) + + # DOIT check + A1 = Matrix([[1, -1], [1, -1]]) + b1 = Matrix([15*t - 10, -15*t - 5]) + sol1 = [C1 + C2*t + C2 - 10*t**3 + 10*t**2 + t*(15*t**2 - 5*t) - 10*t, + C1 + C2*t - 10*t**3 - 5*t**2 + t*(15*t**2 - 5*t) - 5*t] + assert constant_renumber(linodesolve(A1, t, b=b1, type="type2", doit=True), + variables=[t]) == sol1 + + # Testing auto functionality + func = [f(t), g(t)] + eq = [Eq(f(t).diff(t) + g(t).diff(t), g(t) + t), Eq(g(t).diff(t), f(t))] + ceq = canonical_odes(eq, func, t) + (A1, A0), b = linear_ode_to_matrix(ceq[0], func, t, 1) + A = A0 + sol = [-C1*exp(-t/2 + sqrt(5)*t/2)/2 + sqrt(5)*C1*exp(-t/2 + sqrt(5)*t/2)/2 - sqrt(5)*C2*exp(-sqrt(5)*t/2 - + t/2)/2 - C2*exp(-sqrt(5)*t/2 - t/2)/2 - exp(-t/2 + sqrt(5)*t/2)*Integral(t*exp(-sqrt(5)*t/2 + + t/2)/(-5 + sqrt(5)) - sqrt(5)*t*exp(-sqrt(5)*t/2 + t/2)/(-5 + sqrt(5)), t)/2 + sqrt(5)*exp(-t/2 + + sqrt(5)*t/2)*Integral(t*exp(-sqrt(5)*t/2 + t/2)/(-5 + sqrt(5)) - sqrt(5)*t*exp(-sqrt(5)*t/2 + + t/2)/(-5 + sqrt(5)), t)/2 - sqrt(5)*exp(-sqrt(5)*t/2 - t/2)*Integral(-sqrt(5)*t*exp(t/2 + + sqrt(5)*t/2)/5, t)/2 - exp(-sqrt(5)*t/2 - t/2)*Integral(-sqrt(5)*t*exp(t/2 + sqrt(5)*t/2)/5, t)/2, + C1*exp(-t/2 + sqrt(5)*t/2) + C2*exp(-sqrt(5)*t/2 - t/2) + exp(-t/2 + + sqrt(5)*t/2)*Integral(t*exp(-sqrt(5)*t/2 + t/2)/(-5 + sqrt(5)) - sqrt(5)*t*exp(-sqrt(5)*t/2 + + t/2)/(-5 + sqrt(5)), t) + exp(-sqrt(5)*t/2 - + t/2)*Integral(-sqrt(5)*t*exp(t/2 + sqrt(5)*t/2)/5, t)] + assert constant_renumber(linodesolve(A, t, b=b), variables=[t]) == sol + + # non-homogeneous term assumed to be 0 + sol1 = [-C1*exp(-t/2 + sqrt(5)*t/2)/2 + sqrt(5)*C1*exp(-t/2 + sqrt(5)*t/2)/2 - sqrt(5)*C2*exp(-sqrt(5)*t/2 + - t/2)/2 - C2*exp(-sqrt(5)*t/2 - t/2)/2, + C1*exp(-t/2 + sqrt(5)*t/2) + C2*exp(-sqrt(5)*t/2 - t/2)] + assert constant_renumber(linodesolve(A, t, type="type2"), variables=[t]) == sol1 + + # Testing the Errors + raises(ValueError, lambda: linodesolve(t+10, t)) + raises(ValueError, lambda: linodesolve(a*t, t)) + + A1 = Matrix([[1, t], [-t, 1]]) + B1, _ = _is_commutative_anti_derivative(A1, t) + raises(NonSquareMatrixError, lambda: linodesolve(A1[:, :1], t, B=B1)) + raises(ValueError, lambda: linodesolve(A1, t, B=1)) + + A2 = Matrix([[t, t, t], [t, t, t], [t, t, t]]) + B2, _ = _is_commutative_anti_derivative(A2, t) + raises(NonSquareMatrixError, lambda: linodesolve(A2, t, B=B2[:2, :])) + raises(ValueError, lambda: linodesolve(A2, t, B=2)) + raises(ValueError, lambda: linodesolve(A2, t, B=B2, type="type31")) + + raises(ValueError, lambda: linodesolve(A1, t, B=B2)) + raises(ValueError, lambda: linodesolve(A2, t, B=B1)) + + # Testing auto functionality + func = [f(t), g(t)] + eq = [Eq(f(t).diff(t), f(t) + t*g(t)), Eq(g(t).diff(t), -t*f(t) + g(t))] + ceq = canonical_odes(eq, func, t) + (A1, A0), b = linear_ode_to_matrix(ceq[0], func, t, 1) + A = A0 + sol = [(C1/2 - I*C2/2)*exp(I*t**2/2 + t) + (C1/2 + I*C2/2)*exp(-I*t**2/2 + t), + (-I*C1/2 + C2/2)*exp(-I*t**2/2 + t) + (I*C1/2 + C2/2)*exp(I*t**2/2 + t)] + assert constant_renumber(linodesolve(A, t), variables=Tuple(*eq).free_symbols) == sol + assert constant_renumber(linodesolve(A, t, type="type3"), variables=Tuple(*eq).free_symbols) == sol + + A1 = Matrix([[t, 1], [t, -1]]) + raises(NotImplementedError, lambda: linodesolve(A1, t)) + + # Testing the Errors + raises(ValueError, lambda: linodesolve(t+10, t, b=Matrix([t+1]))) + raises(ValueError, lambda: linodesolve(a*t, t, b=Matrix([log(t) + sin(t)]))) + + raises(ValueError, lambda: linodesolve(Matrix([7*t]), t, b=t**2)) + raises(ValueError, lambda: linodesolve(Matrix([a + 10*log(t)]), t, b=log(t)*cos(t))) + + raises(ValueError, lambda: linodesolve(7*t, t, b=t**2)) + raises(ValueError, lambda: linodesolve(a*t**2, t, b=log(t) + sin(t))) + + A1 = Matrix([[1, t], [-t, 1]]) + b1 = Matrix([t, t ** 2]) + B1, _ = _is_commutative_anti_derivative(A1, t) + raises(NonSquareMatrixError, lambda: linodesolve(A1[:, :1], t, b=b1)) + + A2 = Matrix([[t, t, t], [t, t, t], [t, t, t]]) + b2 = Matrix([t, 1, t**2]) + B2, _ = _is_commutative_anti_derivative(A2, t) + raises(NonSquareMatrixError, lambda: linodesolve(A2[:2, :], t, b=b2)) + + raises(ValueError, lambda: linodesolve(A1, t, b=b2)) + raises(ValueError, lambda: linodesolve(A2, t, b=b1)) + + raises(ValueError, lambda: linodesolve(A1, t, b=b1, B=B2)) + raises(ValueError, lambda: linodesolve(A2, t, b=b2, B=B1)) + + # Testing auto functionality + func = [f(x), g(x), h(x)] + eq = [Eq(f(x).diff(x), x*(f(x) + g(x) + h(x)) + x), + Eq(g(x).diff(x), x*(f(x) + g(x) + h(x)) + x), + Eq(h(x).diff(x), x*(f(x) + g(x) + h(x)) + 1)] + ceq = canonical_odes(eq, func, x) + (A1, A0), b = linear_ode_to_matrix(ceq[0], func, x, 1) + A = A0 + _x1 = exp(-3*x**2/2) + _x2 = exp(3*x**2/2) + _x3 = Integral(2*_x1*x/3 + _x1/3 + x/3 - Rational(1, 3), x) + _x4 = 2*_x2*_x3/3 + _x5 = Integral(2*_x1*x/3 + _x1/3 - 2*x/3 + Rational(2, 3), x) + sol = [ + C1*_x2/3 - C1/3 + C2*_x2/3 - C2/3 + C3*_x2/3 + 2*C3/3 + _x2*_x5/3 + _x3/3 + _x4 - _x5/3, + C1*_x2/3 + 2*C1/3 + C2*_x2/3 - C2/3 + C3*_x2/3 - C3/3 + _x2*_x5/3 + _x3/3 + _x4 - _x5/3, + C1*_x2/3 - C1/3 + C2*_x2/3 + 2*C2/3 + C3*_x2/3 - C3/3 + _x2*_x5/3 - 2*_x3/3 + _x4 + 2*_x5/3, + ] + assert constant_renumber(linodesolve(A, x, b=b), variables=Tuple(*eq).free_symbols) == sol + assert constant_renumber(linodesolve(A, x, b=b, type="type4"), + variables=Tuple(*eq).free_symbols) == sol + + A1 = Matrix([[t, 1], [t, -1]]) + raises(NotImplementedError, lambda: linodesolve(A1, t, b=b1)) + + # non-homogeneous term not passed + sol1 = [-C1/3 - C2/3 + 2*C3/3 + (C1/3 + C2/3 + C3/3)*exp(3*x**2/2), 2*C1/3 - C2/3 - C3/3 + (C1/3 + C2/3 + C3/3)*exp(3*x**2/2), + -C1/3 + 2*C2/3 - C3/3 + (C1/3 + C2/3 + C3/3)*exp(3*x**2/2)] + assert constant_renumber(linodesolve(A, x, type="type4", doit=True), variables=Tuple(*eq).free_symbols) == sol1 + + +@slow +def test_linear_3eq_order1_type4_slow(): + x, y, z = symbols('x, y, z', cls=Function) + t = Symbol('t') + + f = t ** 3 + log(t) + g = t ** 2 + sin(t) + eq1 = (Eq(diff(x(t), t), (4 * f + g) * x(t) - f * y(t) - 2 * f * z(t)), + Eq(diff(y(t), t), 2 * f * x(t) + (f + g) * y(t) - 2 * f * z(t)), Eq(diff(z(t), t), 5 * f * x(t) + f * y( + t) + (-3 * f + g) * z(t))) + with dotprodsimp(True): + dsolve(eq1) + + +@slow +def test_linear_neq_order1_type2_slow1(): + i, r1, c1, r2, c2, t = symbols('i, r1, c1, r2, c2, t') + x1 = Function('x1') + x2 = Function('x2') + + eq1 = r1*c1*Derivative(x1(t), t) + x1(t) - x2(t) - r1*i + eq2 = r2*c1*Derivative(x1(t), t) + r2*c2*Derivative(x2(t), t) + x2(t) - r2*i + eq = [eq1, eq2] + + # XXX: Solution is too complicated + [sol] = dsolve_system(eq, simplify=False, doit=False) + assert checksysodesol(eq, sol) == (True, [0, 0]) + + +# Regression test case for issue #9204 +# https://github.com/sympy/sympy/issues/9204 +@tooslow +def test_linear_new_order1_type2_de_lorentz_slow_check(): + m = Symbol("m", real=True) + q = Symbol("q", real=True) + t = Symbol("t", real=True) + + e1, e2, e3 = symbols("e1:4", real=True) + b1, b2, b3 = symbols("b1:4", real=True) + v1, v2, v3 = symbols("v1:4", cls=Function, real=True) + + eqs = [ + -e1*q + m*Derivative(v1(t), t) - q*(-b2*v3(t) + b3*v2(t)), + -e2*q + m*Derivative(v2(t), t) - q*(b1*v3(t) - b3*v1(t)), + -e3*q + m*Derivative(v3(t), t) - q*(-b1*v2(t) + b2*v1(t)) + ] + sol = dsolve(eqs) + assert checksysodesol(eqs, sol) == (True, [0, 0, 0]) + + +# Regression test case for issue #14001 +# https://github.com/sympy/sympy/issues/14001 +@slow +def test_linear_neq_order1_type2_slow_check(): + RC, t, C, Vs, L, R1, V0, I0 = symbols("RC t C Vs L R1 V0 I0") + V = Function("V") + I = Function("I") + system = [Eq(V(t).diff(t), -1/RC*V(t) + I(t)/C), Eq(I(t).diff(t), -R1/L*I(t) - 1/L*V(t) + Vs/L)] + [sol] = dsolve_system(system, simplify=False, doit=False) + + assert checksysodesol(system, sol) == (True, [0, 0]) + + +def _linear_3eq_order1_type4_long(): + x, y, z = symbols('x, y, z', cls=Function) + t = Symbol('t') + + f = t ** 3 + log(t) + g = t ** 2 + sin(t) + + eq1 = (Eq(diff(x(t), t), (4*f + g)*x(t) - f*y(t) - 2*f*z(t)), + Eq(diff(y(t), t), 2*f*x(t) + (f + g)*y(t) - 2*f*z(t)), Eq(diff(z(t), t), 5*f*x(t) + f*y( + t) + (-3*f + g)*z(t))) + + dsolve_sol = dsolve(eq1) + dsolve_sol1 = [_simpsol(sol) for sol in dsolve_sol] + + x_1 = sqrt(-t**6 - 8*t**3*log(t) + 8*t**3 - 16*log(t)**2 + 32*log(t) - 16) + x_2 = sqrt(3) + x_3 = 8324372644*C1*x_1*x_2 + 4162186322*C2*x_1*x_2 - 8324372644*C3*x_1*x_2 + x_4 = 1 / (1903457163*t**3 + 3825881643*x_1*x_2 + 7613828652*log(t) - 7613828652) + x_5 = exp(t**3/3 + t*x_1*x_2/4 - cos(t)) + x_6 = exp(t**3/3 - t*x_1*x_2/4 - cos(t)) + x_7 = exp(t**4/2 + t**3/3 + 2*t*log(t) - 2*t - cos(t)) + x_8 = 91238*C1*x_1*x_2 + 91238*C2*x_1*x_2 - 91238*C3*x_1*x_2 + x_9 = 1 / (66049*t**3 - 50629*x_1*x_2 + 264196*log(t) - 264196) + x_10 = 50629 * C1 / 25189 + 37909*C2/25189 - 50629*C3/25189 - x_3*x_4 + x_11 = -50629*C1/25189 - 12720*C2/25189 + 50629*C3/25189 + x_3*x_4 + sol = [Eq(x(t), x_10*x_5 + x_11*x_6 + x_7*(C1 - C2)), Eq(y(t), x_10*x_5 + x_11*x_6), Eq(z(t), x_5*( + -424*C1/257 - 167*C2/257 + 424*C3/257 - x_8*x_9) + x_6*(167*C1/257 + 424*C2/257 - + 167*C3/257 + x_8*x_9) + x_7*(C1 - C2))] + + assert dsolve_sol1 == sol + assert checksysodesol(eq1, dsolve_sol1) == (True, [0, 0, 0]) + + +@slow +def test_neq_order1_type4_slow_check1(): + f, g = symbols("f g", cls=Function) + x = symbols("x") + + eqs = [Eq(diff(f(x), x), x*f(x) + x**2*g(x) + x), + Eq(diff(g(x), x), 2*x**2*f(x) + (x + 3*x**2)*g(x) + 1)] + sol = dsolve(eqs) + assert checksysodesol(eqs, sol) == (True, [0, 0]) + + +@slow +def test_neq_order1_type4_slow_check2(): + f, g, h = symbols("f, g, h", cls=Function) + x = Symbol("x") + + eqs = [ + Eq(Derivative(f(x), x), x*h(x) + f(x) + g(x) + 1), + Eq(Derivative(g(x), x), x*g(x) + f(x) + h(x) + 10), + Eq(Derivative(h(x), x), x*f(x) + x + g(x) + h(x)) + ] + with dotprodsimp(True): + sol = dsolve(eqs) + assert checksysodesol(eqs, sol) == (True, [0, 0, 0]) + + +def _neq_order1_type4_slow3(): + f, g = symbols("f g", cls=Function) + x = symbols("x") + + eqs = [ + Eq(Derivative(f(x), x), x*f(x) + g(x) + sin(x)), + Eq(Derivative(g(x), x), x**2 + x*g(x) - f(x)) + ] + sol = [ + Eq(f(x), (C1/2 - I*C2/2 - I*Integral(x**2*exp(-x**2/2 - I*x)/2 + + x**2*exp(-x**2/2 + I*x)/2 + I*exp(-x**2/2 - I*x)*sin(x)/2 - + I*exp(-x**2/2 + I*x)*sin(x)/2, x)/2 + Integral(-I*x**2*exp(-x**2/2 + - I*x)/2 + I*x**2*exp(-x**2/2 + I*x)/2 + exp(-x**2/2 - + I*x)*sin(x)/2 + exp(-x**2/2 + I*x)*sin(x)/2, x)/2)*exp(x**2/2 + + I*x) + (C1/2 + I*C2/2 + I*Integral(x**2*exp(-x**2/2 - I*x)/2 + + x**2*exp(-x**2/2 + I*x)/2 + I*exp(-x**2/2 - I*x)*sin(x)/2 - + I*exp(-x**2/2 + I*x)*sin(x)/2, x)/2 + Integral(-I*x**2*exp(-x**2/2 + - I*x)/2 + I*x**2*exp(-x**2/2 + I*x)/2 + exp(-x**2/2 - + I*x)*sin(x)/2 + exp(-x**2/2 + I*x)*sin(x)/2, x)/2)*exp(x**2/2 - + I*x)), + Eq(g(x), (-I*C1/2 + C2/2 + Integral(x**2*exp(-x**2/2 - I*x)/2 + + x**2*exp(-x**2/2 + I*x)/2 + I*exp(-x**2/2 - I*x)*sin(x)/2 - + I*exp(-x**2/2 + I*x)*sin(x)/2, x)/2 - + I*Integral(-I*x**2*exp(-x**2/2 - I*x)/2 + I*x**2*exp(-x**2/2 + + I*x)/2 + exp(-x**2/2 - I*x)*sin(x)/2 + exp(-x**2/2 + + I*x)*sin(x)/2, x)/2)*exp(x**2/2 - I*x) + (I*C1/2 + C2/2 + + Integral(x**2*exp(-x**2/2 - I*x)/2 + x**2*exp(-x**2/2 + I*x)/2 + + I*exp(-x**2/2 - I*x)*sin(x)/2 - I*exp(-x**2/2 + I*x)*sin(x)/2, + x)/2 + I*Integral(-I*x**2*exp(-x**2/2 - I*x)/2 + + I*x**2*exp(-x**2/2 + I*x)/2 + exp(-x**2/2 - I*x)*sin(x)/2 + + exp(-x**2/2 + I*x)*sin(x)/2, x)/2)*exp(x**2/2 + I*x)) + ] + + return eqs, sol + + +def test_neq_order1_type4_slow3(): + eqs, sol = _neq_order1_type4_slow3() + assert dsolve_system(eqs, simplify=False, doit=False) == [sol] + # XXX: dsolve gives an error in integration: + # assert dsolve(eqs) == sol + # https://github.com/sympy/sympy/issues/20155 + + +@slow +def test_neq_order1_type4_slow_check3(): + eqs, sol = _neq_order1_type4_slow3() + assert checksysodesol(eqs, sol) == (True, [0, 0]) + + +@tooslow +@XFAIL +def test_linear_3eq_order1_type4_long_dsolve_slow_xfail(): + eq, sol = _linear_3eq_order1_type4_long() + + dsolve_sol = dsolve(eq) + dsolve_sol1 = [_simpsol(sol) for sol in dsolve_sol] + + assert dsolve_sol1 == sol + + +@tooslow +def test_linear_3eq_order1_type4_long_dsolve_dotprodsimp(): + eq, sol = _linear_3eq_order1_type4_long() + + # XXX: Only works with dotprodsimp see + # test_linear_3eq_order1_type4_long_dsolve_slow_xfail which is too slow + with dotprodsimp(True): + dsolve_sol = dsolve(eq) + + dsolve_sol1 = [_simpsol(sol) for sol in dsolve_sol] + assert dsolve_sol1 == sol + + +@tooslow +def test_linear_3eq_order1_type4_long_check(): + eq, sol = _linear_3eq_order1_type4_long() + assert checksysodesol(eq, sol) == (True, [0, 0, 0]) + + +def test_dsolve_system(): + f, g = symbols("f g", cls=Function) + x = symbols("x") + eqs = [Eq(f(x).diff(x), f(x) + g(x)), Eq(g(x).diff(x), f(x) + g(x))] + funcs = [f(x), g(x)] + + sol = [[Eq(f(x), -C1 + C2*exp(2*x)), Eq(g(x), C1 + C2*exp(2*x))]] + assert dsolve_system(eqs, funcs=funcs, t=x, doit=True) == sol + + raises(ValueError, lambda: dsolve_system(1)) + raises(ValueError, lambda: dsolve_system(eqs, 1)) + raises(ValueError, lambda: dsolve_system(eqs, funcs, 1)) + raises(ValueError, lambda: dsolve_system(eqs, funcs[:1], x)) + + eq = (Eq(f(x).diff(x), 12 * f(x) - 6 * g(x)), Eq(g(x).diff(x) ** 2, 11 * f(x) + 3 * g(x))) + raises(NotImplementedError, lambda: dsolve_system(eq) == ([], [])) + + raises(NotImplementedError, lambda: dsolve_system(eq, funcs=[f(x), g(x)]) == ([], [])) + raises(NotImplementedError, lambda: dsolve_system(eq, funcs=[f(x), g(x)], t=x) == ([], [])) + raises(NotImplementedError, lambda: dsolve_system(eq, funcs=[f(x), g(x)], t=x, ics={f(0): 1, g(0): 1}) == ([], [])) + raises(NotImplementedError, lambda: dsolve_system(eq, t=x, ics={f(0): 1, g(0): 1}) == ([], [])) + raises(NotImplementedError, lambda: dsolve_system(eq, ics={f(0): 1, g(0): 1}) == ([], [])) + raises(NotImplementedError, lambda: dsolve_system(eq, funcs=[f(x), g(x)], ics={f(0): 1, g(0): 1}) == ([], [])) + +def test_dsolve(): + + f, g = symbols('f g', cls=Function) + x, y = symbols('x y') + + eqs = [f(x).diff(x) - x, f(x).diff(x) + x] + with raises(ValueError): + dsolve(eqs) + + eqs = [f(x, y).diff(x)] + with raises(ValueError): + dsolve(eqs) + + eqs = [f(x, y).diff(x)+g(x).diff(x), g(x).diff(x)] + with raises(ValueError): + dsolve(eqs) + + +@slow +def test_higher_order1_slow1(): + x, y = symbols("x y", cls=Function) + t = symbols("t") + + eq = [ + Eq(diff(x(t),t,t), (log(t)+t**2)*diff(x(t),t)+(log(t)+t**2)*3*diff(y(t),t)), + Eq(diff(y(t),t,t), (log(t)+t**2)*2*diff(x(t),t)+(log(t)+t**2)*9*diff(y(t),t)) + ] + sol, = dsolve_system(eq, simplify=False, doit=False) + # The solution is too long to write out explicitly and checkodesol is too + # slow so we test for particular values of t: + for e in eq: + res = (e.lhs - e.rhs).subs({sol[0].lhs:sol[0].rhs, sol[1].lhs:sol[1].rhs}) + res = res.subs({d: d.doit(deep=False) for d in res.atoms(Derivative)}) + assert ratsimp(res.subs(t, 1)) == 0 + + +def test_second_order_type2_slow1(): + x, y, z = symbols('x, y, z', cls=Function) + t, l = symbols('t, l') + + eqs1 = [Eq(Derivative(x(t), (t, 2)), t*(2*x(t) + y(t))), + Eq(Derivative(y(t), (t, 2)), t*(-x(t) + 2*y(t)))] + sol1 = [Eq(x(t), I*C1*airyai(t*(2 - I)**(S(1)/3)) + I*C2*airybi(t*(2 - I)**(S(1)/3)) - I*C3*airyai(t*(2 + + I)**(S(1)/3)) - I*C4*airybi(t*(2 + I)**(S(1)/3))), + Eq(y(t), C1*airyai(t*(2 - I)**(S(1)/3)) + C2*airybi(t*(2 - I)**(S(1)/3)) + C3*airyai(t*(2 + I)**(S(1)/3)) + + C4*airybi(t*(2 + I)**(S(1)/3)))] + assert dsolve(eqs1) == sol1 + assert checksysodesol(eqs1, sol1) == (True, [0, 0]) + + +@tooslow +@XFAIL +def test_nonlinear_3eq_order1_type1(): + a, b, c = symbols('a b c') + + eqs = [ + a * f(x).diff(x) - (b - c) * g(x) * h(x), + b * g(x).diff(x) - (c - a) * h(x) * f(x), + c * h(x).diff(x) - (a - b) * f(x) * g(x), + ] + + assert dsolve(eqs) # NotImplementedError + + +@XFAIL +def test_nonlinear_3eq_order1_type4(): + eqs = [ + Eq(f(x).diff(x), (2*h(x)*g(x) - 3*g(x)*h(x))), + Eq(g(x).diff(x), (4*f(x)*h(x) - 2*h(x)*f(x))), + Eq(h(x).diff(x), (3*g(x)*f(x) - 4*f(x)*g(x))), + ] + dsolve(eqs) # KeyError when matching + # sol = ? + # assert dsolve_sol == sol + # assert checksysodesol(eqs, dsolve_sol) == (True, [0, 0, 0]) + + +@tooslow +@XFAIL +def test_nonlinear_3eq_order1_type3(): + eqs = [ + Eq(f(x).diff(x), (2*f(x)**2 - 3 )), + Eq(g(x).diff(x), (4 - 2*h(x) )), + Eq(h(x).diff(x), (3*h(x) - 4*f(x)**2)), + ] + dsolve(eqs) # Not sure if this finishes... + # sol = ? + # assert dsolve_sol == sol + # assert checksysodesol(eqs, dsolve_sol) == (True, [0, 0, 0]) + + +@XFAIL +def test_nonlinear_3eq_order1_type5(): + eqs = [ + Eq(f(x).diff(x), f(x)*(2*f(x) - 3*g(x))), + Eq(g(x).diff(x), g(x)*(4*g(x) - 2*h(x))), + Eq(h(x).diff(x), h(x)*(3*h(x) - 4*f(x))), + ] + dsolve(eqs) # KeyError + # sol = ? + # assert dsolve_sol == sol + # assert checksysodesol(eqs, dsolve_sol) == (True, [0, 0, 0]) + + +def test_linear_2eq_order1(): + x, y, z = symbols('x, y, z', cls=Function) + k, l, m, n = symbols('k, l, m, n', Integer=True) + t = Symbol('t') + x0, y0 = symbols('x0, y0', cls=Function) + + eq1 = (Eq(diff(x(t),t), x(t) + y(t) + 9), Eq(diff(y(t),t), 2*x(t) + 5*y(t) + 23)) + sol1 = [Eq(x(t), C1*exp(t*(sqrt(6) + 3)) + C2*exp(t*(-sqrt(6) + 3)) - Rational(22, 3)), \ + Eq(y(t), C1*(2 + sqrt(6))*exp(t*(sqrt(6) + 3)) + C2*(-sqrt(6) + 2)*exp(t*(-sqrt(6) + 3)) - Rational(5, 3))] + assert checksysodesol(eq1, sol1) == (True, [0, 0]) + + eq2 = (Eq(diff(x(t),t), x(t) + y(t) + 81), Eq(diff(y(t),t), -2*x(t) + y(t) + 23)) + sol2 = [Eq(x(t), (C1*cos(sqrt(2)*t) + C2*sin(sqrt(2)*t))*exp(t) - Rational(58, 3)), \ + Eq(y(t), (-sqrt(2)*C1*sin(sqrt(2)*t) + sqrt(2)*C2*cos(sqrt(2)*t))*exp(t) - Rational(185, 3))] + assert checksysodesol(eq2, sol2) == (True, [0, 0]) + + eq3 = (Eq(diff(x(t),t), 5*t*x(t) + 2*y(t)), Eq(diff(y(t),t), 2*x(t) + 5*t*y(t))) + sol3 = [Eq(x(t), (C1*exp(2*t) + C2*exp(-2*t))*exp(Rational(5, 2)*t**2)), \ + Eq(y(t), (C1*exp(2*t) - C2*exp(-2*t))*exp(Rational(5, 2)*t**2))] + assert checksysodesol(eq3, sol3) == (True, [0, 0]) + + eq4 = (Eq(diff(x(t),t), 5*t*x(t) + t**2*y(t)), Eq(diff(y(t),t), -t**2*x(t) + 5*t*y(t))) + sol4 = [Eq(x(t), (C1*cos((t**3)/3) + C2*sin((t**3)/3))*exp(Rational(5, 2)*t**2)), \ + Eq(y(t), (-C1*sin((t**3)/3) + C2*cos((t**3)/3))*exp(Rational(5, 2)*t**2))] + assert checksysodesol(eq4, sol4) == (True, [0, 0]) + + eq5 = (Eq(diff(x(t),t), 5*t*x(t) + t**2*y(t)), Eq(diff(y(t),t), -t**2*x(t) + (5*t+9*t**2)*y(t))) + sol5 = [Eq(x(t), (C1*exp((sqrt(77)/2 + Rational(9, 2))*(t**3)/3) + \ + C2*exp((-sqrt(77)/2 + Rational(9, 2))*(t**3)/3))*exp(Rational(5, 2)*t**2)), \ + Eq(y(t), (C1*(sqrt(77)/2 + Rational(9, 2))*exp((sqrt(77)/2 + Rational(9, 2))*(t**3)/3) + \ + C2*(-sqrt(77)/2 + Rational(9, 2))*exp((-sqrt(77)/2 + Rational(9, 2))*(t**3)/3))*exp(Rational(5, 2)*t**2))] + assert checksysodesol(eq5, sol5) == (True, [0, 0]) + + eq6 = (Eq(diff(x(t),t), 5*t*x(t) + t**2*y(t)), Eq(diff(y(t),t), (1-t**2)*x(t) + (5*t+9*t**2)*y(t))) + sol6 = [Eq(x(t), C1*x0(t) + C2*x0(t)*Integral(t**2*exp(Integral(5*t, t))*exp(Integral(9*t**2 + 5*t, t))/x0(t)**2, t)), \ + Eq(y(t), C1*y0(t) + C2*(y0(t)*Integral(t**2*exp(Integral(5*t, t))*exp(Integral(9*t**2 + 5*t, t))/x0(t)**2, t) + \ + exp(Integral(5*t, t))*exp(Integral(9*t**2 + 5*t, t))/x0(t)))] + s = dsolve(eq6) + assert s == sol6 # too complicated to test with subs and simplify + # assert checksysodesol(eq10, sol10) == (True, [0, 0]) # this one fails + + +def test_nonlinear_2eq_order1(): + x, y, z = symbols('x, y, z', cls=Function) + t = Symbol('t') + eq1 = (Eq(diff(x(t),t),x(t)*y(t)**3), Eq(diff(y(t),t),y(t)**5)) + sol1 = [ + Eq(x(t), C1*exp((-1/(4*C2 + 4*t))**(Rational(-1, 4)))), + Eq(y(t), -(-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), C1*exp(-1/(-1/(4*C2 + 4*t))**Rational(1, 4))), + Eq(y(t), (-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), C1*exp(-I/(-1/(4*C2 + 4*t))**Rational(1, 4))), + Eq(y(t), -I*(-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), C1*exp(I/(-1/(4*C2 + 4*t))**Rational(1, 4))), + Eq(y(t), I*(-1/(4*C2 + 4*t))**Rational(1, 4))] + assert dsolve(eq1) == sol1 + assert checksysodesol(eq1, sol1) == (True, [0, 0]) + + eq2 = (Eq(diff(x(t),t), exp(3*x(t))*y(t)**3),Eq(diff(y(t),t), y(t)**5)) + sol2 = [ + Eq(x(t), -log(C1 - 3/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), + Eq(y(t), -(-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), -log(C1 + 3/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), + Eq(y(t), (-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), -log(C1 + 3*I/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), + Eq(y(t), -I*(-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), -log(C1 - 3*I/(-1/(4*C2 + 4*t))**Rational(1, 4))/3), + Eq(y(t), I*(-1/(4*C2 + 4*t))**Rational(1, 4))] + assert dsolve(eq2) == sol2 + assert checksysodesol(eq2, sol2) == (True, [0, 0]) + + eq3 = (Eq(diff(x(t),t), y(t)*x(t)), Eq(diff(y(t),t), x(t)**3)) + tt = Rational(2, 3) + sol3 = [ + Eq(x(t), 6**tt/(6*(-sinh(sqrt(C1)*(C2 + t)/2)/sqrt(C1))**tt)), + Eq(y(t), sqrt(C1 + C1/sinh(sqrt(C1)*(C2 + t)/2)**2)/3)] + assert dsolve(eq3) == sol3 + # FIXME: assert checksysodesol(eq3, sol3) == (True, [0, 0]) + + eq4 = (Eq(diff(x(t),t),x(t)*y(t)*sin(t)**2), Eq(diff(y(t),t),y(t)**2*sin(t)**2)) + sol4 = {Eq(x(t), -2*exp(C1)/(C2*exp(C1) + t - sin(2*t)/2)), Eq(y(t), -2/(C1 + t - sin(2*t)/2))} + assert dsolve(eq4) == sol4 + # FIXME: assert checksysodesol(eq4, sol4) == (True, [0, 0]) + + eq5 = (Eq(x(t),t*diff(x(t),t)+diff(x(t),t)*diff(y(t),t)), Eq(y(t),t*diff(y(t),t)+diff(y(t),t)**2)) + sol5 = {Eq(x(t), C1*C2 + C1*t), Eq(y(t), C2**2 + C2*t)} + assert dsolve(eq5) == sol5 + assert checksysodesol(eq5, sol5) == (True, [0, 0]) + + eq6 = (Eq(diff(x(t),t),x(t)**2*y(t)**3), Eq(diff(y(t),t),y(t)**5)) + sol6 = [ + Eq(x(t), 1/(C1 - 1/(-1/(4*C2 + 4*t))**Rational(1, 4))), + Eq(y(t), -(-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), 1/(C1 + (-1/(4*C2 + 4*t))**(Rational(-1, 4)))), + Eq(y(t), (-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), 1/(C1 + I/(-1/(4*C2 + 4*t))**Rational(1, 4))), + Eq(y(t), -I*(-1/(4*C2 + 4*t))**Rational(1, 4)), + Eq(x(t), 1/(C1 - I/(-1/(4*C2 + 4*t))**Rational(1, 4))), + Eq(y(t), I*(-1/(4*C2 + 4*t))**Rational(1, 4))] + assert dsolve(eq6) == sol6 + assert checksysodesol(eq6, sol6) == (True, [0, 0]) + + +@slow +def test_nonlinear_3eq_order1(): + x, y, z = symbols('x, y, z', cls=Function) + t, u = symbols('t u') + eq1 = (4*diff(x(t),t) + 2*y(t)*z(t), 3*diff(y(t),t) - z(t)*x(t), 5*diff(z(t),t) - x(t)*y(t)) + sol1 = [Eq(4*Integral(1/(sqrt(-4*u**2 - 3*C1 + C2)*sqrt(-4*u**2 + 5*C1 - C2)), (u, x(t))), + C3 - sqrt(15)*t/15), Eq(3*Integral(1/(sqrt(-6*u**2 - C1 + 5*C2)*sqrt(3*u**2 + C1 - 4*C2)), + (u, y(t))), C3 + sqrt(5)*t/10), Eq(5*Integral(1/(sqrt(-10*u**2 - 3*C1 + C2)* + sqrt(5*u**2 + 4*C1 - C2)), (u, z(t))), C3 + sqrt(3)*t/6)] + assert [i.dummy_eq(j) for i, j in zip(dsolve(eq1), sol1)] + # FIXME: assert checksysodesol(eq1, sol1) == (True, [0, 0, 0]) + + eq2 = (4*diff(x(t),t) + 2*y(t)*z(t)*sin(t), 3*diff(y(t),t) - z(t)*x(t)*sin(t), 5*diff(z(t),t) - x(t)*y(t)*sin(t)) + sol2 = [Eq(3*Integral(1/(sqrt(-6*u**2 - C1 + 5*C2)*sqrt(3*u**2 + C1 - 4*C2)), (u, x(t))), C3 + + sqrt(5)*cos(t)/10), Eq(4*Integral(1/(sqrt(-4*u**2 - 3*C1 + C2)*sqrt(-4*u**2 + 5*C1 - C2)), + (u, y(t))), C3 - sqrt(15)*cos(t)/15), Eq(5*Integral(1/(sqrt(-10*u**2 - 3*C1 + C2)* + sqrt(5*u**2 + 4*C1 - C2)), (u, z(t))), C3 + sqrt(3)*cos(t)/6)] + assert [i.dummy_eq(j) for i, j in zip(dsolve(eq2), sol2)] + # FIXME: assert checksysodesol(eq2, sol2) == (True, [0, 0, 0]) + + +def test_C1_function_9239(): + t = Symbol('t') + C1 = Function('C1') + C2 = Function('C2') + C3 = Symbol('C3') + C4 = Symbol('C4') + eq = (Eq(diff(C1(t), t), 9*C2(t)), Eq(diff(C2(t), t), 12*C1(t))) + sol = [Eq(C1(t), 9*C3*exp(6*sqrt(3)*t) + 9*C4*exp(-6*sqrt(3)*t)), + Eq(C2(t), 6*sqrt(3)*C3*exp(6*sqrt(3)*t) - 6*sqrt(3)*C4*exp(-6*sqrt(3)*t))] + assert checksysodesol(eq, sol) == (True, [0, 0]) + + +def test_dsolve_linsystem_symbol(): + eps = Symbol('epsilon', positive=True) + eq1 = (Eq(diff(f(x), x), -eps*g(x)), Eq(diff(g(x), x), eps*f(x))) + sol1 = [Eq(f(x), -C1*eps*cos(eps*x) - C2*eps*sin(eps*x)), + Eq(g(x), -C1*eps*sin(eps*x) + C2*eps*cos(eps*x))] + assert checksysodesol(eq1, sol1) == (True, [0, 0]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/pde.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/pde.py new file mode 100644 index 0000000000000000000000000000000000000000..791ac67ae681ea952ea6e1dabacb7220d1843ebc --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/pde.py @@ -0,0 +1,966 @@ +""" +This module contains pdsolve() and different helper functions that it +uses. It is heavily inspired by the ode module and hence the basic +infrastructure remains the same. + +**Functions in this module** + + These are the user functions in this module: + + - pdsolve() - Solves PDE's + - classify_pde() - Classifies PDEs into possible hints for dsolve(). + - pde_separate() - Separate variables in partial differential equation either by + additive or multiplicative separation approach. + + These are the helper functions in this module: + + - pde_separate_add() - Helper function for searching additive separable solutions. + - pde_separate_mul() - Helper function for searching multiplicative + separable solutions. + +**Currently implemented solver methods** + +The following methods are implemented for solving partial differential +equations. See the docstrings of the various pde_hint() functions for +more information on each (run help(pde)): + + - 1st order linear homogeneous partial differential equations + with constant coefficients. + - 1st order linear general partial differential equations + with constant coefficients. + - 1st order linear partial differential equations with + variable coefficients. + +""" +from functools import reduce + +from itertools import combinations_with_replacement +from sympy.simplify import simplify # type: ignore +from sympy.core import Add, S +from sympy.core.function import Function, expand, AppliedUndef, Subs +from sympy.core.relational import Equality, Eq +from sympy.core.symbol import Symbol, Wild, symbols +from sympy.functions import exp +from sympy.integrals.integrals import Integral, integrate +from sympy.utilities.iterables import has_dups, is_sequence +from sympy.utilities.misc import filldedent + +from sympy.solvers.deutils import _preprocess, ode_order, _desolve +from sympy.solvers.solvers import solve +from sympy.simplify.radsimp import collect + +import operator + + +allhints = ( + "1st_linear_constant_coeff_homogeneous", + "1st_linear_constant_coeff", + "1st_linear_constant_coeff_Integral", + "1st_linear_variable_coeff" + ) + + +def pdsolve(eq, func=None, hint='default', dict=False, solvefun=None, **kwargs): + """ + Solves any (supported) kind of partial differential equation. + + **Usage** + + pdsolve(eq, f(x,y), hint) -> Solve partial differential equation + eq for function f(x,y), using method hint. + + **Details** + + ``eq`` can be any supported partial differential equation (see + the pde docstring for supported methods). This can either + be an Equality, or an expression, which is assumed to be + equal to 0. + + ``f(x,y)`` is a function of two variables whose derivatives in that + variable make up the partial differential equation. In many + cases it is not necessary to provide this; it will be autodetected + (and an error raised if it could not be detected). + + ``hint`` is the solving method that you want pdsolve to use. Use + classify_pde(eq, f(x,y)) to get all of the possible hints for + a PDE. The default hint, 'default', will use whatever hint + is returned first by classify_pde(). See Hints below for + more options that you can use for hint. + + ``solvefun`` is the convention used for arbitrary functions returned + by the PDE solver. If not set by the user, it is set by default + to be F. + + **Hints** + + Aside from the various solving methods, there are also some + meta-hints that you can pass to pdsolve(): + + "default": + This uses whatever hint is returned first by + classify_pde(). This is the default argument to + pdsolve(). + + "all": + To make pdsolve apply all relevant classification hints, + use pdsolve(PDE, func, hint="all"). This will return a + dictionary of hint:solution terms. If a hint causes + pdsolve to raise the NotImplementedError, value of that + hint's key will be the exception object raised. The + dictionary will also include some special keys: + + - order: The order of the PDE. See also ode_order() in + deutils.py + - default: The solution that would be returned by + default. This is the one produced by the hint that + appears first in the tuple returned by classify_pde(). + + "all_Integral": + This is the same as "all", except if a hint also has a + corresponding "_Integral" hint, it only returns the + "_Integral" hint. This is useful if "all" causes + pdsolve() to hang because of a difficult or impossible + integral. This meta-hint will also be much faster than + "all", because integrate() is an expensive routine. + + See also the classify_pde() docstring for more info on hints, + and the pde docstring for a list of all supported hints. + + **Tips** + - You can declare the derivative of an unknown function this way: + + >>> from sympy import Function, Derivative + >>> from sympy.abc import x, y # x and y are the independent variables + >>> f = Function("f")(x, y) # f is a function of x and y + >>> # fx will be the partial derivative of f with respect to x + >>> fx = Derivative(f, x) + >>> # fy will be the partial derivative of f with respect to y + >>> fy = Derivative(f, y) + + - See test_pde.py for many tests, which serves also as a set of + examples for how to use pdsolve(). + - pdsolve always returns an Equality class (except for the case + when the hint is "all" or "all_Integral"). Note that it is not possible + to get an explicit solution for f(x, y) as in the case of ODE's + - Do help(pde.pde_hintname) to get help more information on a + specific hint + + + Examples + ======== + + >>> from sympy.solvers.pde import pdsolve + >>> from sympy import Function, Eq + >>> from sympy.abc import x, y + >>> f = Function('f') + >>> u = f(x, y) + >>> ux = u.diff(x) + >>> uy = u.diff(y) + >>> eq = Eq(1 + (2*(ux/u)) + (3*(uy/u)), 0) + >>> pdsolve(eq) + Eq(f(x, y), F(3*x - 2*y)*exp(-2*x/13 - 3*y/13)) + + """ + + if not solvefun: + solvefun = Function('F') + + # See the docstring of _desolve for more details. + hints = _desolve(eq, func=func, hint=hint, simplify=True, + type='pde', **kwargs) + eq = hints.pop('eq', False) + all_ = hints.pop('all', False) + + if all_: + # TODO : 'best' hint should be implemented when adequate + # number of hints are added. + pdedict = {} + failed_hints = {} + gethints = classify_pde(eq, dict=True) + pdedict.update({'order': gethints['order'], + 'default': gethints['default']}) + for hint in hints: + try: + rv = _helper_simplify(eq, hint, hints[hint]['func'], + hints[hint]['order'], hints[hint][hint], solvefun) + except NotImplementedError as detail: + failed_hints[hint] = detail + else: + pdedict[hint] = rv + pdedict.update(failed_hints) + return pdedict + + else: + return _helper_simplify(eq, hints['hint'], hints['func'], + hints['order'], hints[hints['hint']], solvefun) + + +def _helper_simplify(eq, hint, func, order, match, solvefun): + """Helper function of pdsolve that calls the respective + pde functions to solve for the partial differential + equations. This minimizes the computation in + calling _desolve multiple times. + """ + solvefunc = globals()["pde_" + hint.removesuffix("_Integral")] + return _handle_Integral(solvefunc(eq, func, order, + match, solvefun), func, order, hint) + + +def _handle_Integral(expr, func, order, hint): + r""" + Converts a solution with integrals in it into an actual solution. + + Simplifies the integral mainly using doit() + """ + if hint.endswith("_Integral"): + return expr + + elif hint == "1st_linear_constant_coeff": + return simplify(expr.doit()) + + else: + return expr + + +def classify_pde(eq, func=None, dict=False, *, prep=True, **kwargs): + """ + Returns a tuple of possible pdsolve() classifications for a PDE. + + The tuple is ordered so that first item is the classification that + pdsolve() uses to solve the PDE by default. In general, + classifications near the beginning of the list will produce + better solutions faster than those near the end, though there are + always exceptions. To make pdsolve use a different classification, + use pdsolve(PDE, func, hint=). See also the pdsolve() + docstring for different meta-hints you can use. + + If ``dict`` is true, classify_pde() will return a dictionary of + hint:match expression terms. This is intended for internal use by + pdsolve(). Note that because dictionaries are ordered arbitrarily, + this will most likely not be in the same order as the tuple. + + You can get help on different hints by doing help(pde.pde_hintname), + where hintname is the name of the hint without "_Integral". + + See sympy.pde.allhints or the sympy.pde docstring for a list of all + supported hints that can be returned from classify_pde. + + + Examples + ======== + + >>> from sympy.solvers.pde import classify_pde + >>> from sympy import Function, Eq + >>> from sympy.abc import x, y + >>> f = Function('f') + >>> u = f(x, y) + >>> ux = u.diff(x) + >>> uy = u.diff(y) + >>> eq = Eq(1 + (2*(ux/u)) + (3*(uy/u)), 0) + >>> classify_pde(eq) + ('1st_linear_constant_coeff_homogeneous',) + """ + + if func and len(func.args) != 2: + raise NotImplementedError("Right now only partial " + "differential equations of two variables are supported") + + if prep or func is None: + prep, func_ = _preprocess(eq, func) + if func is None: + func = func_ + + if isinstance(eq, Equality): + if eq.rhs != 0: + return classify_pde(eq.lhs - eq.rhs, func) + eq = eq.lhs + + f = func.func + x = func.args[0] + y = func.args[1] + fx = f(x,y).diff(x) + fy = f(x,y).diff(y) + + # TODO : For now pde.py uses support offered by the ode_order function + # to find the order with respect to a multi-variable function. An + # improvement could be to classify the order of the PDE on the basis of + # individual variables. + order = ode_order(eq, f(x,y)) + + # hint:matchdict or hint:(tuple of matchdicts) + # Also will contain "default": and "order":order items. + matching_hints = {'order': order} + + if not order: + if dict: + matching_hints["default"] = None + return matching_hints + return () + + eq = expand(eq) + + a = Wild('a', exclude = [f(x,y)]) + b = Wild('b', exclude = [f(x,y), fx, fy, x, y]) + c = Wild('c', exclude = [f(x,y), fx, fy, x, y]) + d = Wild('d', exclude = [f(x,y), fx, fy, x, y]) + e = Wild('e', exclude = [f(x,y), fx, fy]) + n = Wild('n', exclude = [x, y]) + # Try removing the smallest power of f(x,y) + # from the highest partial derivatives of f(x,y) + reduced_eq = eq + if eq.is_Add: + power = None + for i in set(combinations_with_replacement((x,y), order)): + coeff = eq.coeff(f(x,y).diff(*i)) + if coeff == 1: + continue + match = coeff.match(a*f(x,y)**n) + if match and match[a]: + if power is None or match[n] < power: + power = match[n] + if power: + den = f(x,y)**power + reduced_eq = Add(*[arg/den for arg in eq.args]) + + if order == 1: + reduced_eq = collect(reduced_eq, f(x, y)) + r = reduced_eq.match(b*fx + c*fy + d*f(x,y) + e) + if r: + if not r[e]: + ## Linear first-order homogeneous partial-differential + ## equation with constant coefficients + r.update({'b': b, 'c': c, 'd': d}) + matching_hints["1st_linear_constant_coeff_homogeneous"] = r + elif r[b]**2 + r[c]**2 != 0: + ## Linear first-order general partial-differential + ## equation with constant coefficients + r.update({'b': b, 'c': c, 'd': d, 'e': e}) + matching_hints["1st_linear_constant_coeff"] = r + matching_hints["1st_linear_constant_coeff_Integral"] = r + + else: + b = Wild('b', exclude=[f(x, y), fx, fy]) + c = Wild('c', exclude=[f(x, y), fx, fy]) + d = Wild('d', exclude=[f(x, y), fx, fy]) + r = reduced_eq.match(b*fx + c*fy + d*f(x,y) + e) + if r: + r.update({'b': b, 'c': c, 'd': d, 'e': e}) + matching_hints["1st_linear_variable_coeff"] = r + + # Order keys based on allhints. + rettuple = tuple(i for i in allhints if i in matching_hints) + + if dict: + # Dictionaries are ordered arbitrarily, so make note of which + # hint would come first for pdsolve(). Use an ordered dict in Py 3. + matching_hints["default"] = None + matching_hints["ordered_hints"] = rettuple + for i in allhints: + if i in matching_hints: + matching_hints["default"] = i + break + return matching_hints + return rettuple + + +def checkpdesol(pde, sol, func=None, solve_for_func=True): + """ + Checks if the given solution satisfies the partial differential + equation. + + pde is the partial differential equation which can be given in the + form of an equation or an expression. sol is the solution for which + the pde is to be checked. This can also be given in an equation or + an expression form. If the function is not provided, the helper + function _preprocess from deutils is used to identify the function. + + If a sequence of solutions is passed, the same sort of container will be + used to return the result for each solution. + + The following methods are currently being implemented to check if the + solution satisfies the PDE: + + 1. Directly substitute the solution in the PDE and check. If the + solution has not been solved for f, then it will solve for f + provided solve_for_func has not been set to False. + + If the solution satisfies the PDE, then a tuple (True, 0) is returned. + Otherwise a tuple (False, expr) where expr is the value obtained + after substituting the solution in the PDE. However if a known solution + returns False, it may be due to the inability of doit() to simplify it to zero. + + Examples + ======== + + >>> from sympy import Function, symbols + >>> from sympy.solvers.pde import checkpdesol, pdsolve + >>> x, y = symbols('x y') + >>> f = Function('f') + >>> eq = 2*f(x,y) + 3*f(x,y).diff(x) + 4*f(x,y).diff(y) + >>> sol = pdsolve(eq) + >>> assert checkpdesol(eq, sol)[0] + >>> eq = x*f(x,y) + f(x,y).diff(x) + >>> checkpdesol(eq, sol) + (False, (x*F(4*x - 3*y) - 6*F(4*x - 3*y)/25 + 4*Subs(Derivative(F(_xi_1), _xi_1), _xi_1, 4*x - 3*y))*exp(-6*x/25 - 8*y/25)) + """ + + # Converting the pde into an equation + if not isinstance(pde, Equality): + pde = Eq(pde, 0) + + # If no function is given, try finding the function present. + if func is None: + try: + _, func = _preprocess(pde.lhs) + except ValueError: + funcs = [s.atoms(AppliedUndef) for s in ( + sol if is_sequence(sol, set) else [sol])] + funcs = set().union(funcs) + if len(funcs) != 1: + raise ValueError( + 'must pass func arg to checkpdesol for this case.') + func = funcs.pop() + + # If the given solution is in the form of a list or a set + # then return a list or set of tuples. + if is_sequence(sol, set): + return type(sol)([checkpdesol( + pde, i, func=func, + solve_for_func=solve_for_func) for i in sol]) + + # Convert solution into an equation + if not isinstance(sol, Equality): + sol = Eq(func, sol) + elif sol.rhs == func: + sol = sol.reversed + + # Try solving for the function + solved = sol.lhs == func and not sol.rhs.has(func) + if solve_for_func and not solved: + solved = solve(sol, func) + if solved: + if len(solved) == 1: + return checkpdesol(pde, Eq(func, solved[0]), + func=func, solve_for_func=False) + else: + return checkpdesol(pde, [Eq(func, t) for t in solved], + func=func, solve_for_func=False) + + # try direct substitution of the solution into the PDE and simplify + if sol.lhs == func: + pde = pde.lhs - pde.rhs + s = simplify(pde.subs(func, sol.rhs).doit()) + return s is S.Zero, s + + raise NotImplementedError(filldedent(''' + Unable to test if %s is a solution to %s.''' % (sol, pde))) + + + +def pde_1st_linear_constant_coeff_homogeneous(eq, func, order, match, solvefun): + r""" + Solves a first order linear homogeneous + partial differential equation with constant coefficients. + + The general form of this partial differential equation is + + .. math:: a \frac{\partial f(x,y)}{\partial x} + + b \frac{\partial f(x,y)}{\partial y} + c f(x,y) = 0 + + where `a`, `b` and `c` are constants. + + The general solution is of the form: + + .. math:: + f(x, y) = F(- a y + b x ) e^{- \frac{c (a x + b y)}{a^2 + b^2}} + + and can be found in SymPy with ``pdsolve``:: + + >>> from sympy.solvers import pdsolve + >>> from sympy.abc import x, y, a, b, c + >>> from sympy import Function, pprint + >>> f = Function('f') + >>> u = f(x,y) + >>> ux = u.diff(x) + >>> uy = u.diff(y) + >>> genform = a*ux + b*uy + c*u + >>> pprint(genform) + d d + a*--(f(x, y)) + b*--(f(x, y)) + c*f(x, y) + dx dy + + >>> pprint(pdsolve(genform)) + -c*(a*x + b*y) + --------------- + 2 2 + a + b + f(x, y) = F(-a*y + b*x)*e + + Examples + ======== + + >>> from sympy import pdsolve + >>> from sympy import Function, pprint + >>> from sympy.abc import x,y + >>> f = Function('f') + >>> pdsolve(f(x,y) + f(x,y).diff(x) + f(x,y).diff(y)) + Eq(f(x, y), F(x - y)*exp(-x/2 - y/2)) + >>> pprint(pdsolve(f(x,y) + f(x,y).diff(x) + f(x,y).diff(y))) + x y + - - - - + 2 2 + f(x, y) = F(x - y)*e + + References + ========== + + - Viktor Grigoryan, "Partial Differential Equations" + Math 124A - Fall 2010, pp.7 + + """ + # TODO : For now homogeneous first order linear PDE's having + # two variables are implemented. Once there is support for + # solving systems of ODE's, this can be extended to n variables. + + f = func.func + x = func.args[0] + y = func.args[1] + b = match[match['b']] + c = match[match['c']] + d = match[match['d']] + return Eq(f(x,y), exp(-S(d)/(b**2 + c**2)*(b*x + c*y))*solvefun(c*x - b*y)) + + +def pde_1st_linear_constant_coeff(eq, func, order, match, solvefun): + r""" + Solves a first order linear partial differential equation + with constant coefficients. + + The general form of this partial differential equation is + + .. math:: a \frac{\partial f(x,y)}{\partial x} + + b \frac{\partial f(x,y)}{\partial y} + + c f(x,y) = G(x,y) + + where `a`, `b` and `c` are constants and `G(x, y)` can be an arbitrary + function in `x` and `y`. + + The general solution of the PDE is: + + .. math:: + f(x, y) = \left. \left[F(\eta) + \frac{1}{a^2 + b^2} + \int\limits^{a x + b y} G\left(\frac{a \xi + b \eta}{a^2 + b^2}, + \frac{- a \eta + b \xi}{a^2 + b^2} \right) + e^{\frac{c \xi}{a^2 + b^2}}\, d\xi\right] + e^{- \frac{c \xi}{a^2 + b^2}} + \right|_{\substack{\eta=- a y + b x\\ \xi=a x + b y }}\, , + + where `F(\eta)` is an arbitrary single-valued function. The solution + can be found in SymPy with ``pdsolve``:: + + >>> from sympy.solvers import pdsolve + >>> from sympy.abc import x, y, a, b, c + >>> from sympy import Function, pprint + >>> f = Function('f') + >>> G = Function('G') + >>> u = f(x, y) + >>> ux = u.diff(x) + >>> uy = u.diff(y) + >>> genform = a*ux + b*uy + c*u - G(x,y) + >>> pprint(genform) + d d + a*--(f(x, y)) + b*--(f(x, y)) + c*f(x, y) - G(x, y) + dx dy + >>> pprint(pdsolve(genform, hint='1st_linear_constant_coeff_Integral')) + // a*x + b*y \ \| + || / | || + || | | || + || | c*xi | || + || | ------- | || + || | 2 2 | || + || | /a*xi + b*eta -a*eta + b*xi\ a + b | || + || | G|------------, -------------|*e d(xi)| || + || | | 2 2 2 2 | | || + || | \ a + b a + b / | -c*xi || + || | | -------|| + || / | 2 2|| + || | a + b || + f(x, y) = ||F(eta) + -------------------------------------------------------|*e || + || 2 2 | || + \\ a + b / /|eta=-a*y + b*x, xi=a*x + b*y + + Examples + ======== + + >>> from sympy.solvers.pde import pdsolve + >>> from sympy import Function, pprint, exp + >>> from sympy.abc import x,y + >>> f = Function('f') + >>> eq = -2*f(x,y).diff(x) + 4*f(x,y).diff(y) + 5*f(x,y) - exp(x + 3*y) + >>> pdsolve(eq) + Eq(f(x, y), (F(4*x + 2*y)*exp(x/2) + exp(x + 4*y)/15)*exp(-y)) + + References + ========== + + - Viktor Grigoryan, "Partial Differential Equations" + Math 124A - Fall 2010, pp.7 + + """ + + # TODO : For now homogeneous first order linear PDE's having + # two variables are implemented. Once there is support for + # solving systems of ODE's, this can be extended to n variables. + xi, eta = symbols("xi eta") + f = func.func + x = func.args[0] + y = func.args[1] + b = match[match['b']] + c = match[match['c']] + d = match[match['d']] + e = -match[match['e']] + expterm = exp(-S(d)/(b**2 + c**2)*xi) + functerm = solvefun(eta) + solvedict = solve((b*x + c*y - xi, c*x - b*y - eta), x, y) + # Integral should remain as it is in terms of xi, + # doit() should be done in _handle_Integral. + genterm = (1/S(b**2 + c**2))*Integral( + (1/expterm*e).subs(solvedict), (xi, b*x + c*y)) + return Eq(f(x,y), Subs(expterm*(functerm + genterm), + (eta, xi), (c*x - b*y, b*x + c*y))) + + +def pde_1st_linear_variable_coeff(eq, func, order, match, solvefun): + r""" + Solves a first order linear partial differential equation + with variable coefficients. The general form of this partial + differential equation is + + .. math:: a(x, y) \frac{\partial f(x, y)}{\partial x} + + b(x, y) \frac{\partial f(x, y)}{\partial y} + + c(x, y) f(x, y) = G(x, y) + + where `a(x, y)`, `b(x, y)`, `c(x, y)` and `G(x, y)` are arbitrary + functions in `x` and `y`. This PDE is converted into an ODE by + making the following transformation: + + 1. `\xi` as `x` + + 2. `\eta` as the constant in the solution to the differential + equation `\frac{dy}{dx} = -\frac{b}{a}` + + Making the previous substitutions reduces it to the linear ODE + + .. math:: a(\xi, \eta)\frac{du}{d\xi} + c(\xi, \eta)u - G(\xi, \eta) = 0 + + which can be solved using ``dsolve``. + + >>> from sympy.abc import x, y + >>> from sympy import Function, pprint + >>> a, b, c, G, f= [Function(i) for i in ['a', 'b', 'c', 'G', 'f']] + >>> u = f(x,y) + >>> ux = u.diff(x) + >>> uy = u.diff(y) + >>> genform = a(x, y)*u + b(x, y)*ux + c(x, y)*uy - G(x,y) + >>> pprint(genform) + d d + -G(x, y) + a(x, y)*f(x, y) + b(x, y)*--(f(x, y)) + c(x, y)*--(f(x, y)) + dx dy + + + Examples + ======== + + >>> from sympy.solvers.pde import pdsolve + >>> from sympy import Function, pprint + >>> from sympy.abc import x,y + >>> f = Function('f') + >>> eq = x*(u.diff(x)) - y*(u.diff(y)) + y**2*u - y**2 + >>> pdsolve(eq) + Eq(f(x, y), F(x*y)*exp(y**2/2) + 1) + + References + ========== + + - Viktor Grigoryan, "Partial Differential Equations" + Math 124A - Fall 2010, pp.7 + + """ + from sympy.solvers.ode import dsolve + + eta = symbols("eta") + f = func.func + x = func.args[0] + y = func.args[1] + b = match[match['b']] + c = match[match['c']] + d = match[match['d']] + e = -match[match['e']] + + + if not d: + # To deal with cases like b*ux = e or c*uy = e + if not (b and c): + if c: + try: + tsol = integrate(e/c, y) + except NotImplementedError: + raise NotImplementedError("Unable to find a solution" + " due to inability of integrate") + else: + return Eq(f(x,y), solvefun(x) + tsol) + if b: + try: + tsol = integrate(e/b, x) + except NotImplementedError: + raise NotImplementedError("Unable to find a solution" + " due to inability of integrate") + else: + return Eq(f(x,y), solvefun(y) + tsol) + + if not c: + # To deal with cases when c is 0, a simpler method is used. + # The PDE reduces to b*(u.diff(x)) + d*u = e, which is a linear ODE in x + plode = f(x).diff(x)*b + d*f(x) - e + sol = dsolve(plode, f(x)) + syms = sol.free_symbols - plode.free_symbols - {x, y} + rhs = _simplify_variable_coeff(sol.rhs, syms, solvefun, y) + return Eq(f(x, y), rhs) + + if not b: + # To deal with cases when b is 0, a simpler method is used. + # The PDE reduces to c*(u.diff(y)) + d*u = e, which is a linear ODE in y + plode = f(y).diff(y)*c + d*f(y) - e + sol = dsolve(plode, f(y)) + syms = sol.free_symbols - plode.free_symbols - {x, y} + rhs = _simplify_variable_coeff(sol.rhs, syms, solvefun, x) + return Eq(f(x, y), rhs) + + dummy = Function('d') + h = (c/b).subs(y, dummy(x)) + sol = dsolve(dummy(x).diff(x) - h, dummy(x)) + if isinstance(sol, list): + sol = sol[0] + solsym = sol.free_symbols - h.free_symbols - {x, y} + if len(solsym) == 1: + solsym = solsym.pop() + etat = (solve(sol, solsym)[0]).subs(dummy(x), y) + ysub = solve(eta - etat, y)[0] + deq = (b*(f(x).diff(x)) + d*f(x) - e).subs(y, ysub) + final = (dsolve(deq, f(x), hint='1st_linear')).rhs + if isinstance(final, list): + final = final[0] + finsyms = final.free_symbols - deq.free_symbols - {x, y} + rhs = _simplify_variable_coeff(final, finsyms, solvefun, etat) + return Eq(f(x, y), rhs) + + else: + raise NotImplementedError("Cannot solve the partial differential equation due" + " to inability of constantsimp") + + +def _simplify_variable_coeff(sol, syms, func, funcarg): + r""" + Helper function to replace constants by functions in 1st_linear_variable_coeff + """ + eta = Symbol("eta") + if len(syms) == 1: + sym = syms.pop() + final = sol.subs(sym, func(funcarg)) + + else: + for sym in syms: + final = sol.subs(sym, func(funcarg)) + + return simplify(final.subs(eta, funcarg)) + + +def pde_separate(eq, fun, sep, strategy='mul'): + """Separate variables in partial differential equation either by additive + or multiplicative separation approach. It tries to rewrite an equation so + that one of the specified variables occurs on a different side of the + equation than the others. + + :param eq: Partial differential equation + + :param fun: Original function F(x, y, z) + + :param sep: List of separated functions [X(x), u(y, z)] + + :param strategy: Separation strategy. You can choose between additive + separation ('add') and multiplicative separation ('mul') which is + default. + + Examples + ======== + + >>> from sympy import E, Eq, Function, pde_separate, Derivative as D + >>> from sympy.abc import x, t + >>> u, X, T = map(Function, 'uXT') + + >>> eq = Eq(D(u(x, t), x), E**(u(x, t))*D(u(x, t), t)) + >>> pde_separate(eq, u(x, t), [X(x), T(t)], strategy='add') + [exp(-X(x))*Derivative(X(x), x), exp(T(t))*Derivative(T(t), t)] + + >>> eq = Eq(D(u(x, t), x, 2), D(u(x, t), t, 2)) + >>> pde_separate(eq, u(x, t), [X(x), T(t)], strategy='mul') + [Derivative(X(x), (x, 2))/X(x), Derivative(T(t), (t, 2))/T(t)] + + See Also + ======== + pde_separate_add, pde_separate_mul + """ + + do_add = False + if strategy == 'add': + do_add = True + elif strategy == 'mul': + do_add = False + else: + raise ValueError('Unknown strategy: %s' % strategy) + + if isinstance(eq, Equality): + if eq.rhs != 0: + return pde_separate(Eq(eq.lhs - eq.rhs, 0), fun, sep, strategy) + else: + return pde_separate(Eq(eq, 0), fun, sep, strategy) + + if eq.rhs != 0: + raise ValueError("Value should be 0") + + # Handle arguments + orig_args = list(fun.args) + subs_args = [arg for s in sep for arg in s.args] + + if do_add: + functions = reduce(operator.add, sep) + else: + functions = reduce(operator.mul, sep) + + # Check whether variables match + if len(subs_args) != len(orig_args): + raise ValueError("Variable counts do not match") + # Check for duplicate arguments like [X(x), u(x, y)] + if has_dups(subs_args): + raise ValueError("Duplicate substitution arguments detected") + # Check whether the variables match + if set(orig_args) != set(subs_args): + raise ValueError("Arguments do not match") + + # Substitute original function with separated... + result = eq.lhs.subs(fun, functions).doit() + + # Divide by terms when doing multiplicative separation + if not do_add: + eq = 0 + for i in result.args: + eq += i/functions + result = eq + + svar = subs_args[0] + dvar = subs_args[1:] + return _separate(result, svar, dvar) + + +def pde_separate_add(eq, fun, sep): + """ + Helper function for searching additive separable solutions. + + Consider an equation of two independent variables x, y and a dependent + variable w, we look for the product of two functions depending on different + arguments: + + `w(x, y, z) = X(x) + y(y, z)` + + Examples + ======== + + >>> from sympy import E, Eq, Function, pde_separate_add, Derivative as D + >>> from sympy.abc import x, t + >>> u, X, T = map(Function, 'uXT') + + >>> eq = Eq(D(u(x, t), x), E**(u(x, t))*D(u(x, t), t)) + >>> pde_separate_add(eq, u(x, t), [X(x), T(t)]) + [exp(-X(x))*Derivative(X(x), x), exp(T(t))*Derivative(T(t), t)] + + """ + return pde_separate(eq, fun, sep, strategy='add') + + +def pde_separate_mul(eq, fun, sep): + """ + Helper function for searching multiplicative separable solutions. + + Consider an equation of two independent variables x, y and a dependent + variable w, we look for the product of two functions depending on different + arguments: + + `w(x, y, z) = X(x)*u(y, z)` + + Examples + ======== + + >>> from sympy import Function, Eq, pde_separate_mul, Derivative as D + >>> from sympy.abc import x, y + >>> u, X, Y = map(Function, 'uXY') + + >>> eq = Eq(D(u(x, y), x, 2), D(u(x, y), y, 2)) + >>> pde_separate_mul(eq, u(x, y), [X(x), Y(y)]) + [Derivative(X(x), (x, 2))/X(x), Derivative(Y(y), (y, 2))/Y(y)] + + """ + return pde_separate(eq, fun, sep, strategy='mul') + + +def _separate(eq, dep, others): + """Separate expression into two parts based on dependencies of variables.""" + + # FIRST PASS + # Extract derivatives depending our separable variable... + terms = set() + for term in eq.args: + if term.is_Mul: + for i in term.args: + if i.is_Derivative and not i.has(*others): + terms.add(term) + continue + elif term.is_Derivative and not term.has(*others): + terms.add(term) + # Find the factor that we need to divide by + div = set() + for term in terms: + ext, sep = term.expand().as_independent(dep) + # Failed? + if sep.has(*others): + return None + div.add(ext) + # FIXME: Find lcm() of all the divisors and divide with it, instead of + # current hack :( + # https://github.com/sympy/sympy/issues/4597 + if len(div) > 0: + # double sum required or some tests will fail + eq = Add(*[simplify(Add(*[term/i for i in div])) for term in eq.args]) + # SECOND PASS - separate the derivatives + div = set() + lhs = rhs = 0 + for term in eq.args: + # Check, whether we have already term with independent variable... + if not term.has(*others): + lhs += term + continue + # ...otherwise, try to separate + temp, sep = term.expand().as_independent(dep) + # Failed? + if sep.has(*others): + return None + # Extract the divisors + div.add(sep) + rhs -= term.expand() + # Do the division + fulldiv = reduce(operator.add, div) + lhs = simplify(lhs/fulldiv).expand() + rhs = simplify(rhs/fulldiv).expand() + # ...and check whether we were successful :) + if lhs.has(*others) or rhs.has(dep): + return None + return [lhs, rhs] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/polysys.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/polysys.py new file mode 100644 index 0000000000000000000000000000000000000000..2edc70b36c25b986c975c33fcc57535ef0b31df2 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/polysys.py @@ -0,0 +1,872 @@ +"""Solvers of systems of polynomial equations. """ + +from __future__ import annotations + +from typing import Any +from collections.abc import Sequence, Iterable + +import itertools + +from sympy import Dummy +from sympy.core import S +from sympy.core.expr import Expr +from sympy.core.exprtools import factor_terms +from sympy.core.sorting import default_sort_key +from sympy.logic.boolalg import Boolean +from sympy.polys import Poly, groebner, roots +from sympy.polys.domains import ZZ +from sympy.polys.polyoptions import build_options +from sympy.polys.polytools import parallel_poly_from_expr, sqf_part +from sympy.polys.polyerrors import ( + ComputationFailed, + PolificationFailed, + CoercionFailed, + GeneratorsNeeded, + DomainError +) +from sympy.simplify import rcollect +from sympy.utilities import postfixes +from sympy.utilities.iterables import cartes +from sympy.utilities.misc import filldedent +from sympy.logic.boolalg import Or, And +from sympy.core.relational import Eq + + +class SolveFailed(Exception): + """Raised when solver's conditions were not met. """ + + +def solve_poly_system(seq, *gens, strict=False, **args): + """ + Return a list of solutions for the system of polynomial equations + or else None. + + Parameters + ========== + + seq: a list/tuple/set + Listing all the equations that are needed to be solved + gens: generators + generators of the equations in seq for which we want the + solutions + strict: a boolean (default is False) + if strict is True, NotImplementedError will be raised if + the solution is known to be incomplete (which can occur if + not all solutions are expressible in radicals) + args: Keyword arguments + Special options for solving the equations. + + + Returns + ======= + + List[Tuple] + a list of tuples with elements being solutions for the + symbols in the order they were passed as gens + None + None is returned when the computed basis contains only the ground. + + Examples + ======== + + >>> from sympy import solve_poly_system + >>> from sympy.abc import x, y + + >>> solve_poly_system([x*y - 2*y, 2*y**2 - x**2], x, y) + [(0, 0), (2, -sqrt(2)), (2, sqrt(2))] + + >>> solve_poly_system([x**5 - x + y**3, y**2 - 1], x, y, strict=True) + Traceback (most recent call last): + ... + UnsolvableFactorError + + """ + try: + polys, opt = parallel_poly_from_expr(seq, *gens, **args) + except PolificationFailed as exc: + raise ComputationFailed('solve_poly_system', len(seq), exc) + + if len(polys) == len(opt.gens) == 2: + f, g = polys + + if all(i <= 2 for i in f.degree_list() + g.degree_list()): + try: + return solve_biquadratic(f, g, opt) + except SolveFailed: + pass + + return solve_generic(polys, opt, strict=strict) + + +def solve_biquadratic(f, g, opt): + """Solve a system of two bivariate quadratic polynomial equations. + + Parameters + ========== + + f: a single Expr or Poly + First equation + g: a single Expr or Poly + Second Equation + opt: an Options object + For specifying keyword arguments and generators + + Returns + ======= + + List[Tuple] + a list of tuples with elements being solutions for the + symbols in the order they were passed as gens + None + None is returned when the computed basis contains only the ground. + + Examples + ======== + + >>> from sympy import Options, Poly + >>> from sympy.abc import x, y + >>> from sympy.solvers.polysys import solve_biquadratic + >>> NewOption = Options((x, y), {'domain': 'ZZ'}) + + >>> a = Poly(y**2 - 4 + x, y, x, domain='ZZ') + >>> b = Poly(y*2 + 3*x - 7, y, x, domain='ZZ') + >>> solve_biquadratic(a, b, NewOption) + [(1/3, 3), (41/27, 11/9)] + + >>> a = Poly(y + x**2 - 3, y, x, domain='ZZ') + >>> b = Poly(-y + x - 4, y, x, domain='ZZ') + >>> solve_biquadratic(a, b, NewOption) + [(7/2 - sqrt(29)/2, -sqrt(29)/2 - 1/2), (sqrt(29)/2 + 7/2, -1/2 + \ + sqrt(29)/2)] + """ + G = groebner([f, g]) + + if len(G) == 1 and G[0].is_ground: + return None + + if len(G) != 2: + raise SolveFailed + + x, y = opt.gens + p, q = G + if not p.gcd(q).is_ground: + # not 0-dimensional + raise SolveFailed + + p = Poly(p, x, expand=False) + p_roots = [rcollect(expr, y) for expr in roots(p).keys()] + + q = q.ltrim(-1) + q_roots = list(roots(q).keys()) + + solutions = [(p_root.subs(y, q_root), q_root) for q_root, p_root in + itertools.product(q_roots, p_roots)] + + return sorted(solutions, key=default_sort_key) + + +def solve_generic(polys, opt, strict=False): + """ + Solve a generic system of polynomial equations. + + Returns all possible solutions over C[x_1, x_2, ..., x_m] of a + set F = { f_1, f_2, ..., f_n } of polynomial equations, using + Groebner basis approach. For now only zero-dimensional systems + are supported, which means F can have at most a finite number + of solutions. If the basis contains only the ground, None is + returned. + + The algorithm works by the fact that, supposing G is the basis + of F with respect to an elimination order (here lexicographic + order is used), G and F generate the same ideal, they have the + same set of solutions. By the elimination property, if G is a + reduced, zero-dimensional Groebner basis, then there exists an + univariate polynomial in G (in its last variable). This can be + solved by computing its roots. Substituting all computed roots + for the last (eliminated) variable in other elements of G, new + polynomial system is generated. Applying the above procedure + recursively, a finite number of solutions can be found. + + The ability of finding all solutions by this procedure depends + on the root finding algorithms. If no solutions were found, it + means only that roots() failed, but the system is solvable. To + overcome this difficulty use numerical algorithms instead. + + Parameters + ========== + + polys: a list/tuple/set + Listing all the polynomial equations that are needed to be solved + opt: an Options object + For specifying keyword arguments and generators + strict: a boolean + If strict is True, NotImplementedError will be raised if the solution + is known to be incomplete + + Returns + ======= + + List[Tuple] + a list of tuples with elements being solutions for the + symbols in the order they were passed as gens + None + None is returned when the computed basis contains only the ground. + + References + ========== + + .. [Buchberger01] B. Buchberger, Groebner Bases: A Short + Introduction for Systems Theorists, In: R. Moreno-Diaz, + B. Buchberger, J.L. Freire, Proceedings of EUROCAST'01, + February, 2001 + + .. [Cox97] D. Cox, J. Little, D. O'Shea, Ideals, Varieties + and Algorithms, Springer, Second Edition, 1997, pp. 112 + + Raises + ======== + + NotImplementedError + If the system is not zero-dimensional (does not have a finite + number of solutions) + + UnsolvableFactorError + If ``strict`` is True and not all solution components are + expressible in radicals + + Examples + ======== + + >>> from sympy import Poly, Options + >>> from sympy.solvers.polysys import solve_generic + >>> from sympy.abc import x, y + >>> NewOption = Options((x, y), {'domain': 'ZZ'}) + + >>> a = Poly(x - y + 5, x, y, domain='ZZ') + >>> b = Poly(x + y - 3, x, y, domain='ZZ') + >>> solve_generic([a, b], NewOption) + [(-1, 4)] + + >>> a = Poly(x - 2*y + 5, x, y, domain='ZZ') + >>> b = Poly(2*x - y - 3, x, y, domain='ZZ') + >>> solve_generic([a, b], NewOption) + [(11/3, 13/3)] + + >>> a = Poly(x**2 + y, x, y, domain='ZZ') + >>> b = Poly(x + y*4, x, y, domain='ZZ') + >>> solve_generic([a, b], NewOption) + [(0, 0), (1/4, -1/16)] + + >>> a = Poly(x**5 - x + y**3, x, y, domain='ZZ') + >>> b = Poly(y**2 - 1, x, y, domain='ZZ') + >>> solve_generic([a, b], NewOption, strict=True) + Traceback (most recent call last): + ... + UnsolvableFactorError + + """ + def _is_univariate(f): + """Returns True if 'f' is univariate in its last variable. """ + for monom in f.monoms(): + if any(monom[:-1]): + return False + + return True + + def _subs_root(f, gen, zero): + """Replace generator with a root so that the result is nice. """ + p = f.as_expr({gen: zero}) + + if f.degree(gen) >= 2: + p = p.expand(deep=False) + + return p + + def _solve_reduced_system(system, gens, entry=False): + """Recursively solves reduced polynomial systems. """ + if len(system) == len(gens) == 1: + # the below line will produce UnsolvableFactorError if + # strict=True and the solution from `roots` is incomplete + zeros = list(roots(system[0], gens[-1], strict=strict).keys()) + return [(zero,) for zero in zeros] + + basis = groebner(system, gens, polys=True) + + if len(basis) == 1 and basis[0].is_ground: + if not entry: + return [] + else: + return None + + univariate = list(filter(_is_univariate, basis)) + + if len(basis) < len(gens): + raise NotImplementedError(filldedent(''' + only zero-dimensional systems supported + (finite number of solutions) + ''')) + + if len(univariate) == 1: + f = univariate.pop() + else: + raise NotImplementedError(filldedent(''' + only zero-dimensional systems supported + (finite number of solutions) + ''')) + + gens = f.gens + gen = gens[-1] + + # the below line will produce UnsolvableFactorError if + # strict=True and the solution from `roots` is incomplete + zeros = list(roots(f.ltrim(gen), strict=strict).keys()) + + if not zeros: + return [] + + if len(basis) == 1: + return [(zero,) for zero in zeros] + + solutions = [] + + for zero in zeros: + new_system = [] + new_gens = gens[:-1] + + for b in basis[:-1]: + eq = _subs_root(b, gen, zero) + + if eq is not S.Zero: + new_system.append(eq) + + for solution in _solve_reduced_system(new_system, new_gens): + solutions.append(solution + (zero,)) + + if solutions and len(solutions[0]) != len(gens): + raise NotImplementedError(filldedent(''' + only zero-dimensional systems supported + (finite number of solutions) + ''')) + return solutions + + try: + result = _solve_reduced_system(polys, opt.gens, entry=True) + except CoercionFailed: + raise NotImplementedError + + if result is not None: + return sorted(result, key=default_sort_key) + + +def solve_triangulated(polys, *gens, **args): + """ + Solve a polynomial system using Gianni-Kalkbrenner algorithm. + + The algorithm proceeds by computing one Groebner basis in the ground + domain and then by iteratively computing polynomial factorizations in + appropriately constructed algebraic extensions of the ground domain. + + Parameters + ========== + + polys: a list/tuple/set + Listing all the equations that are needed to be solved + gens: generators + generators of the equations in polys for which we want the + solutions + args: Keyword arguments + Special options for solving the equations + + Returns + ======= + + List[Tuple] + A List of tuples. Solutions for symbols that satisfy the + equations listed in polys + + Examples + ======== + + >>> from sympy import solve_triangulated + >>> from sympy.abc import x, y, z + + >>> F = [x**2 + y + z - 1, x + y**2 + z - 1, x + y + z**2 - 1] + + >>> solve_triangulated(F, x, y, z) + [(0, 0, 1), (0, 1, 0), (1, 0, 0)] + + Using extension for algebraic solutions. + + >>> solve_triangulated(F, x, y, z, extension=True) #doctest: +NORMALIZE_WHITESPACE + [(0, 0, 1), (0, 1, 0), (1, 0, 0), + (CRootOf(x**2 + 2*x - 1, 0), CRootOf(x**2 + 2*x - 1, 0), CRootOf(x**2 + 2*x - 1, 0)), + (CRootOf(x**2 + 2*x - 1, 1), CRootOf(x**2 + 2*x - 1, 1), CRootOf(x**2 + 2*x - 1, 1))] + + References + ========== + + 1. Patrizia Gianni, Teo Mora, Algebraic Solution of System of + Polynomial Equations using Groebner Bases, AAECC-5 on Applied Algebra, + Algebraic Algorithms and Error-Correcting Codes, LNCS 356 247--257, 1989 + + """ + opt = build_options(gens, args) + + G = groebner(polys, gens, polys=True) + G = list(reversed(G)) + + extension = opt.get('extension', False) + if extension: + def _solve_univariate(f): + return [r for r, _ in f.all_roots(multiple=False, radicals=False)] + else: + domain = opt.get('domain') + + if domain is not None: + for i, g in enumerate(G): + G[i] = g.set_domain(domain) + + def _solve_univariate(f): + return list(f.ground_roots().keys()) + + f, G = G[0].ltrim(-1), G[1:] + dom = f.get_domain() + + zeros = _solve_univariate(f) + + if extension: + solutions = {((zero,), dom.algebraic_field(zero)) for zero in zeros} + else: + solutions = {((zero,), dom) for zero in zeros} + + var_seq = reversed(gens[:-1]) + vars_seq = postfixes(gens[1:]) + + for var, vars in zip(var_seq, vars_seq): + _solutions = set() + + for values, dom in solutions: + H, mapping = [], list(zip(vars, values)) + + for g in G: + _vars = (var,) + vars + + if g.has_only_gens(*_vars) and g.degree(var) != 0: + if extension: + g = g.set_domain(g.domain.unify(dom)) + h = g.ltrim(var).eval(dict(mapping)) + + if g.degree(var) == h.degree(): + H.append(h) + + p = min(H, key=lambda h: h.degree()) + zeros = _solve_univariate(p) + + for zero in zeros: + if not (zero in dom): + dom_zero = dom.algebraic_field(zero) + else: + dom_zero = dom + + _solutions.add(((zero,) + values, dom_zero)) + + solutions = _solutions + return sorted((s for s, _ in solutions), key=default_sort_key) + + +def factor_system(eqs: Sequence[Expr | complex], gens: Sequence[Expr] = (), **kwargs: Any) -> list[list[Expr]]: + """ + Factorizes a system of polynomial equations into + irreducible subsystems. + + Parameters + ========== + + eqs : list + List of expressions to be factored. + Each expression is assumed to be equal to zero. + + gens : list, optional + Generator(s) of the polynomial ring. + If not provided, all free symbols will be used. + + **kwargs : dict, optional + Same optional arguments taken by ``factor`` + + Returns + ======= + + list[list[Expr]] + A list of lists of expressions, where each sublist represents + an irreducible subsystem. When solved, each subsystem gives + one component of the solution. Only generic solutions are + returned (cases not requiring parameters to be zero). + + Examples + ======== + + >>> from sympy.solvers.polysys import factor_system, factor_system_cond + >>> from sympy.abc import x, y, a, b, c + + A simple system with multiple solutions: + + >>> factor_system([x**2 - 1, y - 1]) + [[x + 1, y - 1], [x - 1, y - 1]] + + A system with no solution: + + >>> factor_system([x, 1]) + [] + + A system where any value of the symbol(s) is a solution: + + >>> factor_system([x - x, (x + 1)**2 - (x**2 + 2*x + 1)]) + [[]] + + A system with no generic solution: + + >>> factor_system([a*x*(x-1), b*y, c], [x, y]) + [] + + If c is added to the unknowns then the system has a generic solution: + + >>> factor_system([a*x*(x-1), b*y, c], [x, y, c]) + [[x - 1, y, c], [x, y, c]] + + Alternatively :func:`factor_system_cond` can be used to get degenerate + cases as well: + + >>> factor_system_cond([a*x*(x-1), b*y, c], [x, y]) + [[x - 1, y, c], [x, y, c], [x - 1, b, c], [x, b, c], [y, a, c], [a, b, c]] + + Each of the above cases is only satisfiable in the degenerate case `c = 0`. + + The solution set of the original system represented + by eqs is the union of the solution sets of the + factorized systems. + + An empty list [] means no generic solution exists. + A list containing an empty list [[]] means any value of + the symbol(s) is a solution. + + See Also + ======== + + factor_system_cond : Returns both generic and degenerate solutions + factor_system_bool : Returns a Boolean combination representing all solutions + sympy.polys.polytools.factor : Factors a polynomial into irreducible factors + over the rational numbers + """ + + systems = _factor_system_poly_from_expr(eqs, gens, **kwargs) + systems_generic = [sys for sys in systems if not _is_degenerate(sys)] + systems_expr = [[p.as_expr() for p in system] for system in systems_generic] + return systems_expr + + +def _is_degenerate(system: list[Poly]) -> bool: + """Helper function to check if a system is degenerate""" + return any(p.is_ground for p in system) + + +def factor_system_bool(eqs: Sequence[Expr | complex], gens: Sequence[Expr] = (), **kwargs: Any) -> Boolean: + """ + Factorizes a system of polynomial equations into irreducible DNF. + + The system of expressions(eqs) is taken and a Boolean combination + of equations is returned that represents the same solution set. + The result is in disjunctive normal form (OR of ANDs). + + Parameters + ========== + + eqs : list + List of expressions to be factored. + Each expression is assumed to be equal to zero. + + gens : list, optional + Generator(s) of the polynomial ring. + If not provided, all free symbols will be used. + + **kwargs : dict, optional + Optional keyword arguments + + + Returns + ======= + + Boolean: + A Boolean combination of equations. The result is typically in + the form of a conjunction (AND) of a disjunctive normal form + with additional conditions. + + Examples + ======== + + >>> from sympy.solvers.polysys import factor_system_bool + >>> from sympy.abc import x, y, a, b, c + >>> factor_system_bool([x**2 - 1]) + Eq(x - 1, 0) | Eq(x + 1, 0) + + >>> factor_system_bool([x**2 - 1, y - 1]) + (Eq(x - 1, 0) & Eq(y - 1, 0)) | (Eq(x + 1, 0) & Eq(y - 1, 0)) + + >>> eqs = [a * (x - 1), b] + >>> factor_system_bool([a*(x - 1), b]) + (Eq(a, 0) & Eq(b, 0)) | (Eq(b, 0) & Eq(x - 1, 0)) + + >>> factor_system_bool([a*x**2 - a, b*(x + 1), c], [x]) + (Eq(c, 0) & Eq(x + 1, 0)) | (Eq(a, 0) & Eq(b, 0) & Eq(c, 0)) | (Eq(b, 0) & Eq(c, 0) & Eq(x - 1, 0)) + + >>> factor_system_bool([x**2 + 2*x + 1 - (x + 1)**2]) + True + + The result is logically equivalent to the system of equations + i.e. eqs. The function returns ``True`` when all values of + the symbol(s) is a solution and ``False`` when the system + cannot be solved. + + See Also + ======== + + factor_system : Returns factors and solvability condition separately + factor_system_cond : Returns both factors and conditions + + """ + + systems = factor_system_cond(eqs, gens, **kwargs) + return Or(*[And(*[Eq(eq, 0) for eq in sys]) for sys in systems]) + + +def factor_system_cond(eqs: Sequence[Expr | complex], gens: Sequence[Expr] = (), **kwargs: Any) -> list[list[Expr]]: + """ + Factorizes a polynomial system into irreducible components and returns + both generic and degenerate solutions. + + Parameters + ========== + + eqs : list + List of expressions to be factored. + Each expression is assumed to be equal to zero. + + gens : list, optional + Generator(s) of the polynomial ring. + If not provided, all free symbols will be used. + + **kwargs : dict, optional + Optional keyword arguments. + + Returns + ======= + + list[list[Expr]] + A list of lists of expressions, where each sublist represents + an irreducible subsystem. Includes both generic solutions and + degenerate cases requiring equality conditions on parameters. + + Examples + ======== + + >>> from sympy.solvers.polysys import factor_system_cond + >>> from sympy.abc import x, y, a, b, c + + >>> factor_system_cond([x**2 - 4, a*y, b], [x, y]) + [[x + 2, y, b], [x - 2, y, b], [x + 2, a, b], [x - 2, a, b]] + + >>> factor_system_cond([a*x*(x-1), b*y, c], [x, y]) + [[x - 1, y, c], [x, y, c], [x - 1, b, c], [x, b, c], [y, a, c], [a, b, c]] + + An empty list [] means no solution exists. + A list containing an empty list [[]] means any value of + the symbol(s) is a solution. + + See Also + ======== + + factor_system : Returns only generic solutions + factor_system_bool : Returns a Boolean combination representing all solutions + sympy.polys.polytools.factor : Factors a polynomial into irreducible factors + over the rational numbers + """ + systems_poly = _factor_system_poly_from_expr(eqs, gens, **kwargs) + systems = [[p.as_expr() for p in system] for system in systems_poly] + return systems + + +def _factor_system_poly_from_expr( + eqs: Sequence[Expr | complex], gens: Sequence[Expr], **kwargs: Any +) -> list[list[Poly]]: + """ + Convert expressions to polynomials and factor the system. + + Takes a sequence of expressions, converts them to + polynomials, and factors the resulting system. Handles both regular + polynomial systems and purely numerical cases. + """ + try: + polys, opts = parallel_poly_from_expr(eqs, *gens, **kwargs) + only_numbers = False + except (GeneratorsNeeded, PolificationFailed): + _u = Dummy('u') + polys, opts = parallel_poly_from_expr(eqs, [_u], **kwargs) + assert opts['domain'].is_Numerical + only_numbers = True + + if only_numbers: + return [[]] if all(p == 0 for p in polys) else [] + + return factor_system_poly(polys) + + +def factor_system_poly(polys: list[Poly]) -> list[list[Poly]]: + """ + Factors a system of polynomial equations into irreducible subsystems + + Core implementation that works directly with Poly instances. + + Parameters + ========== + + polys : list[Poly] + A list of Poly instances to be factored. + + Returns + ======= + + list[list[Poly]] + A list of lists of polynomials, where each sublist represents + an irreducible component of the solution. Includes both + generic and degenerate cases. + + Examples + ======== + + >>> from sympy import symbols, Poly, ZZ + >>> from sympy.solvers.polysys import factor_system_poly + >>> a, b, c, x = symbols('a b c x') + >>> p1 = Poly((a - 1)*(x - 2), x, domain=ZZ[a,b,c]) + >>> p2 = Poly((b - 3)*(x - 2), x, domain=ZZ[a,b,c]) + >>> p3 = Poly(c, x, domain=ZZ[a,b,c]) + + The equation to be solved for x is ``x - 2 = 0`` provided either + of the two conditions on the parameters ``a`` and ``b`` is nonzero + and the constant parameter ``c`` should be zero. + + >>> sys1, sys2 = factor_system_poly([p1, p2, p3]) + >>> sys1 + [Poly(x - 2, x, domain='ZZ[a,b,c]'), + Poly(c, x, domain='ZZ[a,b,c]')] + >>> sys2 + [Poly(a - 1, x, domain='ZZ[a,b,c]'), + Poly(b - 3, x, domain='ZZ[a,b,c]'), + Poly(c, x, domain='ZZ[a,b,c]')] + + An empty list [] when returned means no solution exists. + Whereas a list containing an empty list [[]] means any value is a solution. + + See Also + ======== + + factor_system : Returns only generic solutions + factor_system_bool : Returns a Boolean combination representing the solutions + factor_system_cond : Returns both generic and degenerate solutions + sympy.polys.polytools.factor : Factors a polynomial into irreducible factors + over the rational numbers + """ + if not all(isinstance(poly, Poly) for poly in polys): + raise TypeError("polys should be a list of Poly instances") + if not polys: + return [[]] + + base_domain = polys[0].domain + base_gens = polys[0].gens + if not all(poly.domain == base_domain and poly.gens == base_gens for poly in polys[1:]): + raise DomainError("All polynomials must have the same domain and generators") + + factor_sets = [] + for poly in polys: + constant, factors_mult = poly.factor_list() + + if constant.is_zero is True: + continue + elif constant.is_zero is False: + if not factors_mult: + return [] + factor_sets.append([f for f, _ in factors_mult]) + else: + constant = sqf_part(factor_terms(constant).as_coeff_Mul()[1]) + constp = Poly(constant, base_gens, domain=base_domain) + factors = [f for f, _ in factors_mult] + factors.append(constp) + factor_sets.append(factors) + + if not factor_sets: + return [[]] + + result = _factor_sets(factor_sets) + return _sort_systems(result) + + +def _factor_sets_slow(eqs: list[list]) -> set[frozenset]: + """ + Helper to find the minimal set of factorised subsystems that is + equivalent to the original system. + + The result is in DNF. + """ + if not eqs: + return {frozenset()} + systems_set = {frozenset(sys) for sys in cartes(*eqs)} + return {s1 for s1 in systems_set if not any(s1 > s2 for s2 in systems_set)} + + +def _factor_sets(eqs: list[list]) -> set[frozenset]: + """ + Helper that builds factor combinations. + """ + if not eqs: + return {frozenset()} + + current_set = min(eqs, key=len) + other_sets = [s for s in eqs if s is not current_set] + + stack = [(factor, [s for s in other_sets if factor not in s], {factor}) + for factor in current_set] + + result = set() + + while stack: + factor, remaining_sets, current_solution = stack.pop() + + if not remaining_sets: + result.add(frozenset(current_solution)) + continue + + next_set = min(remaining_sets, key=len) + next_remaining = [s for s in remaining_sets if s is not next_set] + + for next_factor in next_set: + valid_remaining = [s for s in next_remaining if next_factor not in s] + new_solution = current_solution | {next_factor} + stack.append((next_factor, valid_remaining, new_solution)) + + return {s1 for s1 in result if not any(s1 > s2 for s2 in result)} + + +def _sort_systems(systems: Iterable[Iterable[Poly]]) -> list[list[Poly]]: + """Sorts a list of lists of polynomials""" + systems_list = [sorted(s, key=_poly_sort_key, reverse=True) for s in systems] + return sorted(systems_list, key=_sys_sort_key, reverse=True) + + +def _poly_sort_key(poly): + """Sort key for polynomials""" + if poly.domain.is_FF: + poly = poly.set_domain(ZZ) + return poly.degree_list(), poly.rep.to_list() + + +def _sys_sort_key(sys): + """Sort key for lists of polynomials""" + return list(zip(*map(_poly_sort_key, sys))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/recurr.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/recurr.py new file mode 100644 index 0000000000000000000000000000000000000000..ba627bbd4cb0844f11a8743634f5f10328aadca8 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/recurr.py @@ -0,0 +1,843 @@ +r""" +This module is intended for solving recurrences or, in other words, +difference equations. Currently supported are linear, inhomogeneous +equations with polynomial or rational coefficients. + +The solutions are obtained among polynomials, rational functions, +hypergeometric terms, or combinations of hypergeometric term which +are pairwise dissimilar. + +``rsolve_X`` functions were meant as a low level interface +for ``rsolve`` which would use Mathematica's syntax. + +Given a recurrence relation: + + .. math:: a_{k}(n) y(n+k) + a_{k-1}(n) y(n+k-1) + + ... + a_{0}(n) y(n) = f(n) + +where `k > 0` and `a_{i}(n)` are polynomials in `n`. To use +``rsolve_X`` we need to put all coefficients in to a list ``L`` of +`k+1` elements the following way: + + ``L = [a_{0}(n), ..., a_{k-1}(n), a_{k}(n)]`` + +where ``L[i]``, for `i=0, \ldots, k`, maps to +`a_{i}(n) y(n+i)` (`y(n+i)` is implicit). + +For example if we would like to compute `m`-th Bernoulli polynomial +up to a constant (example was taken from rsolve_poly docstring), +then we would use `b(n+1) - b(n) = m n^{m-1}` recurrence, which +has solution `b(n) = B_m + C`. + +Then ``L = [-1, 1]`` and `f(n) = m n^(m-1)` and finally for `m=4`: + +>>> from sympy import Symbol, bernoulli, rsolve_poly +>>> n = Symbol('n', integer=True) + +>>> rsolve_poly([-1, 1], 4*n**3, n) +C0 + n**4 - 2*n**3 + n**2 + +>>> bernoulli(4, n) +n**4 - 2*n**3 + n**2 - 1/30 + +For the sake of completeness, `f(n)` can be: + + [1] a polynomial -> rsolve_poly + [2] a rational function -> rsolve_ratio + [3] a hypergeometric function -> rsolve_hyper +""" +from collections import defaultdict + +from sympy.concrete import product +from sympy.core.singleton import S +from sympy.core.numbers import Rational, I +from sympy.core.symbol import Symbol, Wild, Dummy +from sympy.core.relational import Equality +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.sorting import default_sort_key +from sympy.core.sympify import sympify + +from sympy.simplify import simplify, hypersimp, hypersimilar # type: ignore +from sympy.solvers import solve, solve_undetermined_coeffs +from sympy.polys import Poly, quo, gcd, lcm, roots, resultant +from sympy.functions import binomial, factorial, FallingFactorial, RisingFactorial +from sympy.matrices import Matrix, casoratian +from sympy.utilities.iterables import numbered_symbols + + +def rsolve_poly(coeffs, f, n, shift=0, **hints): + r""" + Given linear recurrence operator `\operatorname{L}` of order + `k` with polynomial coefficients and inhomogeneous equation + `\operatorname{L} y = f`, where `f` is a polynomial, we seek for + all polynomial solutions over field `K` of characteristic zero. + + The algorithm performs two basic steps: + + (1) Compute degree `N` of the general polynomial solution. + (2) Find all polynomials of degree `N` or less + of `\operatorname{L} y = f`. + + There are two methods for computing the polynomial solutions. + If the degree bound is relatively small, i.e. it's smaller than + or equal to the order of the recurrence, then naive method of + undetermined coefficients is being used. This gives a system + of algebraic equations with `N+1` unknowns. + + In the other case, the algorithm performs transformation of the + initial equation to an equivalent one for which the system of + algebraic equations has only `r` indeterminates. This method is + quite sophisticated (in comparison with the naive one) and was + invented together by Abramov, Bronstein and Petkovsek. + + It is possible to generalize the algorithm implemented here to + the case of linear q-difference and differential equations. + + Lets say that we would like to compute `m`-th Bernoulli polynomial + up to a constant. For this we can use `b(n+1) - b(n) = m n^{m-1}` + recurrence, which has solution `b(n) = B_m + C`. For example: + + >>> from sympy import Symbol, rsolve_poly + >>> n = Symbol('n', integer=True) + + >>> rsolve_poly([-1, 1], 4*n**3, n) + C0 + n**4 - 2*n**3 + n**2 + + References + ========== + + .. [1] S. A. Abramov, M. Bronstein and M. Petkovsek, On polynomial + solutions of linear operator equations, in: T. Levelt, ed., + Proc. ISSAC '95, ACM Press, New York, 1995, 290-296. + + .. [2] M. Petkovsek, Hypergeometric solutions of linear recurrences + with polynomial coefficients, J. Symbolic Computation, + 14 (1992), 243-264. + + .. [3] M. Petkovsek, H. S. Wilf, D. Zeilberger, A = B, 1996. + + """ + f = sympify(f) + + if not f.is_polynomial(n): + return None + + homogeneous = f.is_zero + + r = len(coeffs) - 1 + + coeffs = [Poly(coeff, n) for coeff in coeffs] + + polys = [Poly(0, n)]*(r + 1) + terms = [(S.Zero, S.NegativeInfinity)]*(r + 1) + + for i in range(r + 1): + for j in range(i, r + 1): + polys[i] += coeffs[j]*(binomial(j, i).as_poly(n)) + + if not polys[i].is_zero: + (exp,), coeff = polys[i].LT() + terms[i] = (coeff, exp) + + d = b = terms[0][1] + + for i in range(1, r + 1): + if terms[i][1] > d: + d = terms[i][1] + + if terms[i][1] - i > b: + b = terms[i][1] - i + + d, b = int(d), int(b) + + x = Dummy('x') + + degree_poly = S.Zero + + for i in range(r + 1): + if terms[i][1] - i == b: + degree_poly += terms[i][0]*FallingFactorial(x, i) + + nni_roots = list(roots(degree_poly, x, filter='Z', + predicate=lambda r: r >= 0).keys()) + + if nni_roots: + N = [max(nni_roots)] + else: + N = [] + + if homogeneous: + N += [-b - 1] + else: + N += [f.as_poly(n).degree() - b, -b - 1] + + N = int(max(N)) + + if N < 0: + if homogeneous: + if hints.get('symbols', False): + return (S.Zero, []) + else: + return S.Zero + else: + return None + + if N <= r: + C = [] + y = E = S.Zero + + for i in range(N + 1): + C.append(Symbol('C' + str(i + shift))) + y += C[i] * n**i + + for i in range(r + 1): + E += coeffs[i].as_expr()*y.subs(n, n + i) + + solutions = solve_undetermined_coeffs(E - f, C, n) + + if solutions is not None: + _C = C + C = [c for c in C if (c not in solutions)] + result = y.subs(solutions) + else: + return None # TBD + else: + A = r + U = N + A + b + 1 + + nni_roots = list(roots(polys[r], filter='Z', + predicate=lambda r: r >= 0).keys()) + + if nni_roots != []: + a = max(nni_roots) + 1 + else: + a = S.Zero + + def _zero_vector(k): + return [S.Zero] * k + + def _one_vector(k): + return [S.One] * k + + def _delta(p, k): + B = S.One + D = p.subs(n, a + k) + + for i in range(1, k + 1): + B *= Rational(i - k - 1, i) + D += B * p.subs(n, a + k - i) + + return D + + alpha = {} + + for i in range(-A, d + 1): + I = _one_vector(d + 1) + + for k in range(1, d + 1): + I[k] = I[k - 1] * (x + i - k + 1)/k + + alpha[i] = S.Zero + + for j in range(A + 1): + for k in range(d + 1): + B = binomial(k, i + j) + D = _delta(polys[j].as_expr(), k) + + alpha[i] += I[k]*B*D + + V = Matrix(U, A, lambda i, j: int(i == j)) + + if homogeneous: + for i in range(A, U): + v = _zero_vector(A) + + for k in range(1, A + b + 1): + if i - k < 0: + break + + B = alpha[k - A].subs(x, i - k) + + for j in range(A): + v[j] += B * V[i - k, j] + + denom = alpha[-A].subs(x, i) + + for j in range(A): + V[i, j] = -v[j] / denom + else: + G = _zero_vector(U) + + for i in range(A, U): + v = _zero_vector(A) + g = S.Zero + + for k in range(1, A + b + 1): + if i - k < 0: + break + + B = alpha[k - A].subs(x, i - k) + + for j in range(A): + v[j] += B * V[i - k, j] + + g += B * G[i - k] + + denom = alpha[-A].subs(x, i) + + for j in range(A): + V[i, j] = -v[j] / denom + + G[i] = (_delta(f, i - A) - g) / denom + + P, Q = _one_vector(U), _zero_vector(A) + + for i in range(1, U): + P[i] = (P[i - 1] * (n - a - i + 1)/i).expand() + + for i in range(A): + Q[i] = Add(*[(v*p).expand() for v, p in zip(V[:, i], P)]) + + if not homogeneous: + h = Add(*[(g*p).expand() for g, p in zip(G, P)]) + + C = [Symbol('C' + str(i + shift)) for i in range(A)] + + g = lambda i: Add(*[c*_delta(q, i) for c, q in zip(C, Q)]) + + if homogeneous: + E = [g(i) for i in range(N + 1, U)] + else: + E = [g(i) + _delta(h, i) for i in range(N + 1, U)] + + if E != []: + solutions = solve(E, *C) + + if not solutions: + if homogeneous: + if hints.get('symbols', False): + return (S.Zero, []) + else: + return S.Zero + else: + return None + else: + solutions = {} + + if homogeneous: + result = S.Zero + else: + result = h + + _C = C[:] + for c, q in list(zip(C, Q)): + if c in solutions: + s = solutions[c]*q + C.remove(c) + else: + s = c*q + + result += s.expand() + + if C != _C: + # renumber so they are contiguous + result = result.xreplace(dict(zip(C, _C))) + C = _C[:len(C)] + + if hints.get('symbols', False): + return (result, C) + else: + return result + + +def rsolve_ratio(coeffs, f, n, **hints): + r""" + Given linear recurrence operator `\operatorname{L}` of order `k` + with polynomial coefficients and inhomogeneous equation + `\operatorname{L} y = f`, where `f` is a polynomial, we seek + for all rational solutions over field `K` of characteristic zero. + + This procedure accepts only polynomials, however if you are + interested in solving recurrence with rational coefficients + then use ``rsolve`` which will pre-process the given equation + and run this procedure with polynomial arguments. + + The algorithm performs two basic steps: + + (1) Compute polynomial `v(n)` which can be used as universal + denominator of any rational solution of equation + `\operatorname{L} y = f`. + + (2) Construct new linear difference equation by substitution + `y(n) = u(n)/v(n)` and solve it for `u(n)` finding all its + polynomial solutions. Return ``None`` if none were found. + + The algorithm implemented here is a revised version of the original + Abramov's algorithm, developed in 1989. The new approach is much + simpler to implement and has better overall efficiency. This + method can be easily adapted to the q-difference equations case. + + Besides finding rational solutions alone, this functions is + an important part of Hyper algorithm where it is used to find + a particular solution for the inhomogeneous part of a recurrence. + + Examples + ======== + + >>> from sympy.abc import x + >>> from sympy.solvers.recurr import rsolve_ratio + >>> rsolve_ratio([-2*x**3 + x**2 + 2*x - 1, 2*x**3 + x**2 - 6*x, + ... - 2*x**3 - 11*x**2 - 18*x - 9, 2*x**3 + 13*x**2 + 22*x + 8], 0, x) + C0*(2*x - 3)/(2*(x**2 - 1)) + + References + ========== + + .. [1] S. A. Abramov, Rational solutions of linear difference + and q-difference equations with polynomial coefficients, + in: T. Levelt, ed., Proc. ISSAC '95, ACM Press, New York, + 1995, 285-289 + + See Also + ======== + + rsolve_hyper + """ + f = sympify(f) + + if not f.is_polynomial(n): + return None + + coeffs = list(map(sympify, coeffs)) + + r = len(coeffs) - 1 + + A, B = coeffs[r], coeffs[0] + A = A.subs(n, n - r).expand() + + h = Dummy('h') + + res = resultant(A, B.subs(n, n + h), n) + + if not res.is_polynomial(h): + p, q = res.as_numer_denom() + res = quo(p, q, h) + + nni_roots = list(roots(res, h, filter='Z', + predicate=lambda r: r >= 0).keys()) + + if not nni_roots: + return rsolve_poly(coeffs, f, n, **hints) + else: + C, numers = S.One, [S.Zero]*(r + 1) + + for i in range(int(max(nni_roots)), -1, -1): + d = gcd(A, B.subs(n, n + i), n) + + A = quo(A, d, n) + B = quo(B, d.subs(n, n - i), n) + + C *= Mul(*[d.subs(n, n - j) for j in range(i + 1)]) + + denoms = [C.subs(n, n + i) for i in range(r + 1)] + + for i in range(r + 1): + g = gcd(coeffs[i], denoms[i], n) + + numers[i] = quo(coeffs[i], g, n) + denoms[i] = quo(denoms[i], g, n) + + for i in range(r + 1): + numers[i] *= Mul(*(denoms[:i] + denoms[i + 1:])) + + result = rsolve_poly(numers, f * Mul(*denoms), n, **hints) + + if result is not None: + if hints.get('symbols', False): + return (simplify(result[0] / C), result[1]) + else: + return simplify(result / C) + else: + return None + + +def rsolve_hyper(coeffs, f, n, **hints): + r""" + Given linear recurrence operator `\operatorname{L}` of order `k` + with polynomial coefficients and inhomogeneous equation + `\operatorname{L} y = f` we seek for all hypergeometric solutions + over field `K` of characteristic zero. + + The inhomogeneous part can be either hypergeometric or a sum + of a fixed number of pairwise dissimilar hypergeometric terms. + + The algorithm performs three basic steps: + + (1) Group together similar hypergeometric terms in the + inhomogeneous part of `\operatorname{L} y = f`, and find + particular solution using Abramov's algorithm. + + (2) Compute generating set of `\operatorname{L}` and find basis + in it, so that all solutions are linearly independent. + + (3) Form final solution with the number of arbitrary + constants equal to dimension of basis of `\operatorname{L}`. + + Term `a(n)` is hypergeometric if it is annihilated by first order + linear difference equations with polynomial coefficients or, in + simpler words, if consecutive term ratio is a rational function. + + The output of this procedure is a linear combination of fixed + number of hypergeometric terms. However the underlying method + can generate larger class of solutions - D'Alembertian terms. + + Note also that this method not only computes the kernel of the + inhomogeneous equation, but also reduces in to a basis so that + solutions generated by this procedure are linearly independent + + Examples + ======== + + >>> from sympy.solvers import rsolve_hyper + >>> from sympy.abc import x + + >>> rsolve_hyper([-1, -1, 1], 0, x) + C0*(1/2 - sqrt(5)/2)**x + C1*(1/2 + sqrt(5)/2)**x + + >>> rsolve_hyper([-1, 1], 1 + x, x) + C0 + x*(x + 1)/2 + + References + ========== + + .. [1] M. Petkovsek, Hypergeometric solutions of linear recurrences + with polynomial coefficients, J. Symbolic Computation, + 14 (1992), 243-264. + + .. [2] M. Petkovsek, H. S. Wilf, D. Zeilberger, A = B, 1996. + """ + coeffs = list(map(sympify, coeffs)) + + f = sympify(f) + + r, kernel, symbols = len(coeffs) - 1, [], set() + + if not f.is_zero: + if f.is_Add: + similar = {} + + for g in f.expand().args: + if not g.is_hypergeometric(n): + return None + + for h in similar.keys(): + if hypersimilar(g, h, n): + similar[h] += g + break + else: + similar[g] = S.Zero + + inhomogeneous = [g + h for g, h in similar.items()] + elif f.is_hypergeometric(n): + inhomogeneous = [f] + else: + return None + + for i, g in enumerate(inhomogeneous): + coeff, polys = S.One, coeffs[:] + denoms = [S.One]*(r + 1) + + s = hypersimp(g, n) + + for j in range(1, r + 1): + coeff *= s.subs(n, n + j - 1) + + p, q = coeff.as_numer_denom() + + polys[j] *= p + denoms[j] = q + + for j in range(r + 1): + polys[j] *= Mul(*(denoms[:j] + denoms[j + 1:])) + + # FIXME: The call to rsolve_ratio below should suffice (rsolve_poly + # call can be removed) but the XFAIL test_rsolve_ratio_missed must + # be fixed first. + R = rsolve_ratio(polys, Mul(*denoms), n, symbols=True) + if R is not None: + R, syms = R + if syms: + R = R.subs(zip(syms, [0]*len(syms))) + else: + R = rsolve_poly(polys, Mul(*denoms), n) + + if R: + inhomogeneous[i] *= R + else: + return None + + result = Add(*inhomogeneous) + result = simplify(result) + else: + result = S.Zero + + Z = Dummy('Z') + + p, q = coeffs[0], coeffs[r].subs(n, n - r + 1) + + p_factors = list(roots(p, n).keys()) + q_factors = list(roots(q, n).keys()) + + factors = [(S.One, S.One)] + + for p in p_factors: + for q in q_factors: + if p.is_integer and q.is_integer and p <= q: + continue + else: + factors += [(n - p, n - q)] + + p = [(n - p, S.One) for p in p_factors] + q = [(S.One, n - q) for q in q_factors] + + factors = p + factors + q + + for A, B in factors: + polys, degrees = [], [] + D = A*B.subs(n, n + r - 1) + + for i in range(r + 1): + a = Mul(*[A.subs(n, n + j) for j in range(i)]) + b = Mul(*[B.subs(n, n + j) for j in range(i, r)]) + + poly = quo(coeffs[i]*a*b, D, n) + polys.append(poly.as_poly(n)) + + if not poly.is_zero: + degrees.append(polys[i].degree()) + + if degrees: + d, poly = max(degrees), S.Zero + else: + return None + + for i in range(r + 1): + coeff = polys[i].nth(d) + + if coeff is not S.Zero: + poly += coeff * Z**i + + for z in roots(poly, Z).keys(): + if z.is_zero: + continue + + recurr_coeffs = [polys[i].as_expr()*z**i for i in range(r + 1)] + if d == 0 and 0 != Add(*[recurr_coeffs[j]*j for j in range(1, r + 1)]): + # faster inline check (than calling rsolve_poly) for a + # constant solution to a constant coefficient recurrence. + sol = [Symbol("C" + str(len(symbols)))] + else: + sol, syms = rsolve_poly(recurr_coeffs, 0, n, len(symbols), symbols=True) + sol = sol.collect(syms) + sol = [sol.coeff(s) for s in syms] + + for C in sol: + ratio = z * A * C.subs(n, n + 1) / B / C + ratio = simplify(ratio) + # If there is a nonnegative root in the denominator of the ratio, + # this indicates that the term y(n_root) is zero, and one should + # start the product with the term y(n_root + 1). + n0 = 0 + for n_root in roots(ratio.as_numer_denom()[1], n).keys(): + if n_root.has(I): + return None + elif (n0 < (n_root + 1)) == True: + n0 = n_root + 1 + K = product(ratio, (n, n0, n - 1)) + if K.has(factorial, FallingFactorial, RisingFactorial): + K = simplify(K) + + if casoratian(kernel + [K], n, zero=False) != 0: + kernel.append(K) + + kernel.sort(key=default_sort_key) + sk = list(zip(numbered_symbols('C'), kernel)) + + for C, ker in sk: + result += C * ker + + if hints.get('symbols', False): + # XXX: This returns the symbols in a non-deterministic order + symbols |= {s for s, k in sk} + return (result, list(symbols)) + else: + return result + + +def rsolve(f, y, init=None): + r""" + Solve univariate recurrence with rational coefficients. + + Given `k`-th order linear recurrence `\operatorname{L} y = f`, + or equivalently: + + .. math:: a_{k}(n) y(n+k) + a_{k-1}(n) y(n+k-1) + + \cdots + a_{0}(n) y(n) = f(n) + + where `a_{i}(n)`, for `i=0, \ldots, k`, are polynomials or rational + functions in `n`, and `f` is a hypergeometric function or a sum + of a fixed number of pairwise dissimilar hypergeometric terms in + `n`, finds all solutions or returns ``None``, if none were found. + + Initial conditions can be given as a dictionary in two forms: + + (1) ``{ n_0 : v_0, n_1 : v_1, ..., n_m : v_m}`` + (2) ``{y(n_0) : v_0, y(n_1) : v_1, ..., y(n_m) : v_m}`` + + or as a list ``L`` of values: + + ``L = [v_0, v_1, ..., v_m]`` + + where ``L[i] = v_i``, for `i=0, \ldots, m`, maps to `y(n_i)`. + + Examples + ======== + + Lets consider the following recurrence: + + .. math:: (n - 1) y(n + 2) - (n^2 + 3 n - 2) y(n + 1) + + 2 n (n + 1) y(n) = 0 + + >>> from sympy import Function, rsolve + >>> from sympy.abc import n + >>> y = Function('y') + + >>> f = (n - 1)*y(n + 2) - (n**2 + 3*n - 2)*y(n + 1) + 2*n*(n + 1)*y(n) + + >>> rsolve(f, y(n)) + 2**n*C0 + C1*factorial(n) + + >>> rsolve(f, y(n), {y(0):0, y(1):3}) + 3*2**n - 3*factorial(n) + + See Also + ======== + + rsolve_poly, rsolve_ratio, rsolve_hyper + + """ + if isinstance(f, Equality): + f = f.lhs - f.rhs + + n = y.args[0] + k = Wild('k', exclude=(n,)) + + # Preprocess user input to allow things like + # y(n) + a*(y(n + 1) + y(n - 1))/2 + f = f.expand().collect(y.func(Wild('m', integer=True))) + + h_part = defaultdict(list) + i_part = [] + for g in Add.make_args(f): + coeff, dep = g.as_coeff_mul(y.func) + if not dep: + i_part.append(coeff) + continue + for h in dep: + if h.is_Function and h.func == y.func: + result = h.args[0].match(n + k) + if result is not None: + h_part[int(result[k])].append(coeff) + continue + raise ValueError( + "'%s(%s + k)' expected, got '%s'" % (y.func, n, h)) + for k in h_part: + h_part[k] = Add(*h_part[k]) + h_part.default_factory = lambda: 0 + i_part = Add(*i_part) + + for k, coeff in h_part.items(): + h_part[k] = simplify(coeff) + + common = S.One + + if not i_part.is_zero and not i_part.is_hypergeometric(n) and \ + not (i_part.is_Add and all((x.is_hypergeometric(n) for x in i_part.expand().args))): + raise ValueError("The independent term should be a sum of hypergeometric functions, got '%s'" % i_part) + + for coeff in h_part.values(): + if coeff.is_rational_function(n): + if not coeff.is_polynomial(n): + common = lcm(common, coeff.as_numer_denom()[1], n) + else: + raise ValueError( + "Polynomial or rational function expected, got '%s'" % coeff) + + i_numer, i_denom = i_part.as_numer_denom() + + if i_denom.is_polynomial(n): + common = lcm(common, i_denom, n) + + if common is not S.One: + for k, coeff in h_part.items(): + numer, denom = coeff.as_numer_denom() + h_part[k] = numer*quo(common, denom, n) + + i_part = i_numer*quo(common, i_denom, n) + + K_min = min(h_part.keys()) + + if K_min < 0: + K = abs(K_min) + + H_part = defaultdict(lambda: S.Zero) + i_part = i_part.subs(n, n + K).expand() + common = common.subs(n, n + K).expand() + + for k, coeff in h_part.items(): + H_part[k + K] = coeff.subs(n, n + K).expand() + else: + H_part = h_part + + K_max = max(H_part.keys()) + coeffs = [H_part[i] for i in range(K_max + 1)] + + result = rsolve_hyper(coeffs, -i_part, n, symbols=True) + + if result is None: + return None + + solution, symbols = result + + if init in ({}, []): + init = None + + if symbols and init is not None: + if isinstance(init, list): + init = {i: init[i] for i in range(len(init))} + + equations = [] + + for k, v in init.items(): + try: + i = int(k) + except TypeError: + if k.is_Function and k.func == y.func: + i = int(k.args[0]) + else: + raise ValueError("Integer or term expected, got '%s'" % k) + + eq = solution.subs(n, i) - v + if eq.has(S.NaN): + eq = solution.limit(n, i) - v + equations.append(eq) + + result = solve(equations, *symbols) + + if not result: + return None + else: + solution = solution.subs(result) + + return solution diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/simplex.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/simplex.py new file mode 100644 index 0000000000000000000000000000000000000000..c8e652cb626507d7829f9bc1c78fc6f49809865f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/simplex.py @@ -0,0 +1,1104 @@ +"""Tools for optimizing a linear function for a given simplex. + +For the linear objective function ``f`` with linear constraints +expressed using `Le`, `Ge` or `Eq` can be found with ``lpmin`` or +``lpmax``. The symbols are **unbounded** unless specifically +constrained. + +As an alternative, the matrices describing the objective and the +constraints, and an optional list of bounds can be passed to +``linprog`` which will solve for the minimization of ``C*x`` +under constraints ``A*x <= b`` and/or ``Aeq*x = beq``, and +individual bounds for variables given as ``(lo, hi)``. The values +returned are **nonnegative** unless bounds are provided that +indicate otherwise. + +Errors that might be raised are UnboundedLPError when there is no +finite solution for the system or InfeasibleLPError when the +constraints represent impossible conditions (i.e. a non-existent + simplex). + +Here is a simple 1-D system: minimize `x` given that ``x >= 1``. + + >>> from sympy.solvers.simplex import lpmin, linprog + >>> from sympy.abc import x + + The function and a list with the constraint is passed directly + to `lpmin`: + + >>> lpmin(x, [x >= 1]) + (1, {x: 1}) + + For `linprog` the matrix for the objective is `[1]` and the + uivariate constraint can be passed as a bound with None acting + as infinity: + + >>> linprog([1], bounds=(1, None)) + (1, [1]) + + Or the matrices, corresponding to ``x >= 1`` expressed as + ``-x <= -1`` as required by the routine, can be passed: + + >>> linprog([1], [-1], [-1]) + (1, [1]) + + If there is no limit for the objective, an error is raised. + In this case there is a valid region of interest (simplex) + but no limit to how small ``x`` can be: + + >>> lpmin(x, []) + Traceback (most recent call last): + ... + sympy.solvers.simplex.UnboundedLPError: + Objective function can assume arbitrarily large values! + + An error is raised if there is no possible solution: + + >>> lpmin(x,[x<=1,x>=2]) + Traceback (most recent call last): + ... + sympy.solvers.simplex.InfeasibleLPError: + Inconsistent/False constraint +""" + +from sympy.core import sympify +from sympy.core.exprtools import factor_terms +from sympy.core.relational import Le, Ge, Eq +from sympy.core.singleton import S +from sympy.core.symbol import Dummy +from sympy.core.sorting import ordered +from sympy.functions.elementary.complexes import sign +from sympy.matrices.dense import Matrix, zeros +from sympy.solvers.solveset import linear_eq_to_matrix +from sympy.utilities.iterables import numbered_symbols +from sympy.utilities.misc import filldedent + + +class UnboundedLPError(Exception): + """ + A linear programming problem is said to be unbounded if its objective + function can assume arbitrarily large values. + + Example + ======= + + Suppose you want to maximize + 2x + subject to + x >= 0 + + There's no upper limit that 2x can take. + """ + + pass + + +class InfeasibleLPError(Exception): + """ + A linear programming problem is considered infeasible if its + constraint set is empty. That is, if the set of all vectors + satisfying the constraints is empty, then the problem is infeasible. + + Example + ======= + + Suppose you want to maximize + x + subject to + x >= 10 + x <= 9 + + No x can satisfy those constraints. + """ + + pass + + +def _pivot(M, i, j): + """ + The pivot element `M[i, j]` is inverted and the rest of the matrix + modified and returned as a new matrix; original is left unmodified. + + Example + ======= + + >>> from sympy.matrices.dense import Matrix + >>> from sympy.solvers.simplex import _pivot + >>> from sympy import var + >>> Matrix(3, 3, var('a:i')) + Matrix([ + [a, b, c], + [d, e, f], + [g, h, i]]) + >>> _pivot(_, 1, 0) + Matrix([ + [-a/d, -a*e/d + b, -a*f/d + c], + [ 1/d, e/d, f/d], + [-g/d, h - e*g/d, i - f*g/d]]) + """ + Mi, Mj, Mij = M[i, :], M[:, j], M[i, j] + if Mij == 0: + raise ZeroDivisionError( + "Tried to pivot about zero-valued entry.") + A = M - Mj * (Mi / Mij) + A[i, :] = Mi / Mij + A[:, j] = -Mj / Mij + A[i, j] = 1 / Mij + return A + + +def _choose_pivot_row(A, B, candidate_rows, pivot_col, Y): + # Choose row with smallest ratio + # If there are ties, pick using Bland's rule + return min(candidate_rows, key=lambda i: (B[i] / A[i, pivot_col], Y[i])) + + +def _simplex(A, B, C, D=None, dual=False): + """Return ``(o, x, y)`` obtained from the two-phase simplex method + using Bland's rule: ``o`` is the minimum value of primal, + ``Cx - D``, under constraints ``Ax <= B`` (with ``x >= 0``) and + the maximum of the dual, ``y^{T}B - D``, under constraints + ``A^{T}*y >= C^{T}`` (with ``y >= 0``). To compute the dual of + the system, pass `dual=True` and ``(o, y, x)`` will be returned. + + Note: the nonnegative constraints for ``x`` and ``y`` supercede + any values of ``A`` and ``B`` that are inconsistent with that + assumption, so if a constraint of ``x >= -1`` is represented + in ``A`` and ``B``, no value will be obtained that is negative; if + a constraint of ``x <= -1`` is represented, an error will be + raised since no solution is possible. + + This routine relies on the ability of determining whether an + expression is 0 or not. This is guaranteed if the input contains + only Float or Rational entries. It will raise a TypeError if + a relationship does not evaluate to True or False. + + Examples + ======== + + >>> from sympy.solvers.simplex import _simplex + >>> from sympy import Matrix + + Consider the simple minimization of ``f = x + y + 1`` under the + constraint that ``y + 2*x >= 4``. This is the "standard form" of + a minimization. + + In the nonnegative quadrant, this inequality describes a area above + a triangle with vertices at (0, 4), (0, 0) and (2, 0). The minimum + of ``f`` occurs at (2, 0). Define A, B, C, D for the standard + minimization: + + >>> A = Matrix([[2, 1]]) + >>> B = Matrix([4]) + >>> C = Matrix([[1, 1]]) + >>> D = Matrix([-1]) + + Confirm that this is the system of interest: + + >>> from sympy.abc import x, y + >>> X = Matrix([x, y]) + >>> (C*X - D)[0] + x + y + 1 + >>> [i >= j for i, j in zip(A*X, B)] + [2*x + y >= 4] + + Since `_simplex` will do a minimization for constraints given as + ``A*x <= B``, the signs of ``A`` and ``B`` must be negated since + the currently correspond to a greater-than inequality: + + >>> _simplex(-A, -B, C, D) + (3, [2, 0], [1/2]) + + The dual of minimizing ``f`` is maximizing ``F = c*y - d`` for + ``a*y <= b`` where ``a``, ``b``, ``c``, ``d`` are derived from the + transpose of the matrix representation of the standard minimization: + + >>> tr = lambda a, b, c, d: [i.T for i in (a, c, b, d)] + >>> a, b, c, d = tr(A, B, C, D) + + This time ``a*x <= b`` is the expected inequality for the `_simplex` + method, but to maximize ``F``, the sign of ``c`` and ``d`` must be + changed (so that minimizing the negative will give the negative of + the maximum of ``F``): + + >>> _simplex(a, b, -c, -d) + (-3, [1/2], [2, 0]) + + The negative of ``F`` and the min of ``f`` are the same. The dual + point `[1/2]` is the value of ``y`` that minimized ``F = c*y - d`` + under constraints a*x <= b``: + + >>> y = Matrix(['y']) + >>> (c*y - d)[0] + 4*y + 1 + >>> [i <= j for i, j in zip(a*y,b)] + [2*y <= 1, y <= 1] + + In this 1-dimensional dual system, the more restrictive constraint is + the first which limits ``y`` between 0 and 1/2 and the maximum of + ``F`` is attained at the nonzero value, hence is ``4*(1/2) + 1 = 3``. + + In this case the values for ``x`` and ``y`` were the same when the + dual representation was solved. This is not always the case (though + the value of the function will be the same). + + >>> l = [[1, 1], [-1, 1], [0, 1], [-1, 0]], [5, 1, 2, -1], [[1, 1]], [-1] + >>> A, B, C, D = [Matrix(i) for i in l] + >>> _simplex(A, B, -C, -D) + (-6, [3, 2], [1, 0, 0, 0]) + >>> _simplex(A, B, -C, -D, dual=True) # [5, 0] != [3, 2] + (-6, [1, 0, 0, 0], [5, 0]) + + In both cases the function has the same value: + + >>> Matrix(C)*Matrix([3, 2]) == Matrix(C)*Matrix([5, 0]) + True + + See Also + ======== + _lp - poses min/max problem in form compatible with _simplex + lpmin - minimization which calls _lp + lpmax - maximimzation which calls _lp + + References + ========== + + .. [1] Thomas S. Ferguson, LINEAR PROGRAMMING: A Concise Introduction + web.tecnico.ulisboa.pt/mcasquilho/acad/or/ftp/FergusonUCLA_lp.pdf + + """ + A, B, C, D = [Matrix(i) for i in (A, B, C, D or [0])] + if dual: + _o, d, p = _simplex(-A.T, C.T, B.T, -D) + return -_o, d, p + + if A and B: + M = Matrix([[A, B], [C, D]]) + else: + if A or B: + raise ValueError("must give A and B") + # no constraints given + M = Matrix([[C, D]]) + n = M.cols - 1 + m = M.rows - 1 + + if not all(i.is_Float or i.is_Rational for i in M): + # with literal Float and Rational we are guaranteed the + # ability of determining whether an expression is 0 or not + raise TypeError(filldedent(""" + Only rationals and floats are allowed. + """ + ) + ) + + # x variables have priority over y variables during Bland's rule + # since False < True + X = [(False, j) for j in range(n)] + Y = [(True, i) for i in range(m)] + + # Phase 1: find a feasible solution or determine none exist + + ## keep track of last pivot row and column + last = None + + while True: + B = M[:-1, -1] + A = M[:-1, :-1] + if all(B[i] >= 0 for i in range(B.rows)): + # We have found a feasible solution + break + + # Find k: first row with a negative rightmost entry + for k in range(B.rows): + if B[k] < 0: + break # use current value of k below + else: + pass # error will raise below + + # Choose pivot column, c + piv_cols = [_ for _ in range(A.cols) if A[k, _] < 0] + if not piv_cols: + raise InfeasibleLPError(filldedent(""" + The constraint set is empty!""")) + _, c = min((X[i], i) for i in piv_cols) # Bland's rule + + # Choose pivot row, r + piv_rows = [_ for _ in range(A.rows) if A[_, c] > 0 and B[_] > 0] + piv_rows.append(k) + r = _choose_pivot_row(A, B, piv_rows, c, Y) + + # check for oscillation + if (r, c) == last: + # Not sure what to do here; it looks like there will be + # oscillations; see o1 test added at this commit to + # see a system with no solution and the o2 for one + # with a solution. In the case of o2, the solution + # from linprog is the same as the one from lpmin, but + # the matrices created in the lpmin case are different + # than those created without replacements in linprog and + # the matrices in the linprog case lead to oscillations. + # If the matrices could be re-written in linprog like + # lpmin does, this behavior could be avoided and then + # perhaps the oscillating case would only occur when + # there is no solution. For now, the output is checked + # before exit if oscillations were detected and an + # error is raised there if the solution was invalid. + # + # cf section 6 of Ferguson for a non-cycling modification + last = True + break + last = r, c + + M = _pivot(M, r, c) + X[c], Y[r] = Y[r], X[c] + + # Phase 2: from a feasible solution, pivot to optimal + while True: + B = M[:-1, -1] + A = M[:-1, :-1] + C = M[-1, :-1] + + # Choose a pivot column, c + piv_cols = [_ for _ in range(n) if C[_] < 0] + if not piv_cols: + break + _, c = min((X[i], i) for i in piv_cols) # Bland's rule + + # Choose a pivot row, r + piv_rows = [_ for _ in range(m) if A[_, c] > 0] + if not piv_rows: + raise UnboundedLPError(filldedent(""" + Objective function can assume + arbitrarily large values!""")) + r = _choose_pivot_row(A, B, piv_rows, c, Y) + + M = _pivot(M, r, c) + X[c], Y[r] = Y[r], X[c] + + argmax = [None] * n + argmin_dual = [None] * m + + for i, (v, n) in enumerate(X): + if v == False: + argmax[n] = 0 + else: + argmin_dual[n] = M[-1, i] + + for i, (v, n) in enumerate(Y): + if v == True: + argmin_dual[n] = 0 + else: + argmax[n] = M[i, -1] + + if last and not all(i >= 0 for i in argmax + argmin_dual): + raise InfeasibleLPError(filldedent(""" + Oscillating system led to invalid solution. + If you believe there was a valid solution, please + report this as a bug.""")) + return -M[-1, -1], argmax, argmin_dual + + +## routines that use _simplex or support those that do + + +def _abcd(M, list=False): + """return parts of M as matrices or lists + + Examples + ======== + + >>> from sympy import Matrix + >>> from sympy.solvers.simplex import _abcd + + >>> m = Matrix(3, 3, range(9)); m + Matrix([ + [0, 1, 2], + [3, 4, 5], + [6, 7, 8]]) + >>> a, b, c, d = _abcd(m) + >>> a + Matrix([ + [0, 1], + [3, 4]]) + >>> b + Matrix([ + [2], + [5]]) + >>> c + Matrix([[6, 7]]) + >>> d + Matrix([[8]]) + + The matrices can be returned as compact lists, too: + + >>> L = a, b, c, d = _abcd(m, list=True); L + ([[0, 1], [3, 4]], [2, 5], [[6, 7]], [8]) + """ + + def aslist(i): + l = i.tolist() + if len(l[0]) == 1: # col vector + return [i[0] for i in l] + return l + + m = M[:-1, :-1], M[:-1, -1], M[-1, :-1], M[-1:, -1:] + if not list: + return m + return tuple([aslist(i) for i in m]) + + +def _m(a, b, c, d=None): + """return Matrix([[a, b], [c, d]]) from matrices + in Matrix or list form. + + Examples + ======== + + >>> from sympy import Matrix + >>> from sympy.solvers.simplex import _abcd, _m + >>> m = Matrix(3, 3, range(9)) + >>> L = _abcd(m, list=True); L + ([[0, 1], [3, 4]], [2, 5], [[6, 7]], [8]) + >>> _abcd(m) + (Matrix([ + [0, 1], + [3, 4]]), Matrix([ + [2], + [5]]), Matrix([[6, 7]]), Matrix([[8]])) + >>> assert m == _m(*L) == _m(*_) + """ + a, b, c, d = [Matrix(i) for i in (a, b, c, d or [0])] + return Matrix([[a, b], [c, d]]) + + +def _primal_dual(M, factor=True): + """return primal and dual function and constraints + assuming that ``M = Matrix([[A, b], [c, d]])`` and the + function ``c*x - d`` is being minimized with ``Ax >= b`` + for nonnegative values of ``x``. The dual and its + constraints will be for maximizing `b.T*y - d` subject + to ``A.T*y <= c.T``. + + Examples + ======== + + >>> from sympy.solvers.simplex import _primal_dual, lpmin, lpmax + >>> from sympy import Matrix + + The following matrix represents the primal task of + minimizing x + y + 7 for y >= x + 1 and y >= -2*x + 3. + The dual task seeks to maximize x + 3*y + 7 with + 2*y - x <= 1 and and x + y <= 1: + + >>> M = Matrix([ + ... [-1, 1, 1], + ... [ 2, 1, 3], + ... [ 1, 1, -7]]) + >>> p, d = _primal_dual(M) + + The minimum of the primal and maximum of the dual are the same + (though they occur at different points): + + >>> lpmin(*p) + (28/3, {x1: 2/3, x2: 5/3}) + >>> lpmax(*d) + (28/3, {y1: 1/3, y2: 2/3}) + + If the equivalent (but canonical) inequalities are + desired, leave `factor=True`, otherwise the unmodified + inequalities for M will be returned. + + >>> m = Matrix([ + ... [-3, -2, 4, -2], + ... [ 2, 0, 0, -2], + ... [ 0, 1, -3, 0]]) + + >>> _primal_dual(m, False) # last condition is 2*x1 >= -2 + ((x2 - 3*x3, + [-3*x1 - 2*x2 + 4*x3 >= -2, 2*x1 >= -2]), + (-2*y1 - 2*y2, + [-3*y1 + 2*y2 <= 0, -2*y1 <= 1, 4*y1 <= -3])) + + >>> _primal_dual(m) # condition now x1 >= -1 + ((x2 - 3*x3, + [-3*x1 - 2*x2 + 4*x3 >= -2, x1 >= -1]), + (-2*y1 - 2*y2, + [-3*y1 + 2*y2 <= 0, -2*y1 <= 1, 4*y1 <= -3])) + + If you pass the transpose of the matrix, the primal will be + identified as the standard minimization problem and the + dual as the standard maximization: + + >>> _primal_dual(m.T) + ((-2*x1 - 2*x2, + [-3*x1 + 2*x2 >= 0, -2*x1 >= 1, 4*x1 >= -3]), + (y2 - 3*y3, + [-3*y1 - 2*y2 + 4*y3 <= -2, y1 <= -1])) + + A matrix must have some size or else None will be returned for + the functions: + + >>> _primal_dual(Matrix([[1, 2]])) + ((x1 - 2, []), (-2, [])) + + >>> _primal_dual(Matrix([])) + ((None, []), (None, [])) + + References + ========== + + .. [1] David Galvin, Relations between Primal and Dual + www3.nd.edu/~dgalvin1/30210/30210_F07/presentations/dual_opt.pdf + """ + if not M: + return (None, []), (None, []) + if not hasattr(M, "shape"): + if len(M) not in (3, 4): + raise ValueError("expecting Matrix or 3 or 4 lists") + M = _m(*M) + m, n = [i - 1 for i in M.shape] + A, b, c, d = _abcd(M) + d = d[0] + _ = lambda x: numbered_symbols(x, start=1) + x = Matrix([i for i, j in zip(_("x"), range(n))]) + yT = Matrix([i for i, j in zip(_("y"), range(m))]).T + + def ineq(L, r, op): + rv = [] + for r in (op(i, j) for i, j in zip(L, r)): + if r == True: + continue + elif r == False: + return [False] + if factor: + f = factor_terms(r) + if f.lhs.is_Mul and f.rhs % f.lhs.args[0] == 0: + assert len(f.lhs.args) == 2, f.lhs + k = f.lhs.args[0] + r = r.func(sign(k) * f.lhs.args[1], f.rhs // abs(k)) + rv.append(r) + return rv + + eq = lambda x, d: x[0] - d if x else -d + F = eq(c * x, d) + f = eq(yT * b, d) + return (F, ineq(A * x, b, Ge)), (f, ineq(yT * A, c, Le)) + + +def _rel_as_nonpos(constr, syms): + """return `(np, d, aux)` where `np` is a list of nonpositive + expressions that represent the given constraints (possibly + rewritten in terms of auxilliary variables) expressible with + nonnegative symbols, and `d` is a dictionary mapping a given + symbols to an expression with an auxilliary variable. In some + cases a symbol will be used as part of the change of variables, + e.g. x: x - z1 instead of x: z1 - z2. + + If any constraint is False/empty, return None. All variables in + ``constr`` are assumed to be unbounded unless explicitly indicated + otherwise with a univariate constraint, e.g. ``x >= 0`` will + restrict ``x`` to nonnegative values. + + The ``syms`` must be included so all symbols can be given an + unbounded assumption if they are not otherwise bound with + univariate conditions like ``x <= 3``. + + Examples + ======== + + >>> from sympy.solvers.simplex import _rel_as_nonpos + >>> from sympy.abc import x, y + >>> _rel_as_nonpos([x >= y, x >= 0, y >= 0], (x, y)) + ([-x + y], {}, []) + >>> _rel_as_nonpos([x >= 3, x <= 5], [x]) + ([_z1 - 2], {x: _z1 + 3}, [_z1]) + >>> _rel_as_nonpos([x <= 5], [x]) + ([], {x: 5 - _z1}, [_z1]) + >>> _rel_as_nonpos([x >= 1], [x]) + ([], {x: _z1 + 1}, [_z1]) + """ + r = {} # replacements to handle change of variables + np = [] # nonpositive expressions + aux = [] # auxilliary symbols added + ui = numbered_symbols("z", start=1, cls=Dummy) # auxilliary symbols + univariate = {} # {x: interval} for univariate constraints + unbound = [] # symbols designated as unbound + syms = set(syms) # the expected syms of the system + + # separate out univariates + for i in constr: + if i == True: + continue # ignore + if i == False: + return # no solution + if i.has(S.Infinity, S.NegativeInfinity): + raise ValueError("only finite bounds are permitted") + if isinstance(i, (Le, Ge)): + i = i.lts - i.gts + freei = i.free_symbols + if freei - syms: + raise ValueError( + "unexpected symbol(s) in constraint: %s" % (freei - syms) + ) + if len(freei) > 1: + np.append(i) + elif freei: + x = freei.pop() + if x in unbound: + continue # will handle later + ivl = Le(i, 0, evaluate=False).as_set() + if x not in univariate: + univariate[x] = ivl + else: + univariate[x] &= ivl + elif i: + return False + else: + raise TypeError(filldedent(""" + only equalities like Eq(x, y) or non-strict + inequalities like x >= y are allowed in lp, not %s""" % i)) + + # introduce auxilliary variables as needed for univariate + # inequalities + for x in syms: + i = univariate.get(x, True) + if not i: + return None # no solution possible + if i == True: + unbound.append(x) + continue + a, b = i.inf, i.sup + if a.is_infinite: + u = next(ui) + r[x] = b - u + aux.append(u) + elif b.is_infinite: + if a: + u = next(ui) + r[x] = a + u + aux.append(u) + else: + # standard nonnegative relationship + pass + else: + u = next(ui) + aux.append(u) + # shift so u = x - a => x = u + a + r[x] = u + a + # add constraint for u <= b - a + # since when u = b-a then x = u + a = b - a + a = b: + # the upper limit for x + np.append(u - (b - a)) + + # make change of variables for unbound variables + for x in unbound: + u = next(ui) + r[x] = u - x # reusing x + aux.append(u) + + return np, r, aux + + +def _lp_matrices(objective, constraints): + """return A, B, C, D, r, x+X, X for maximizing + objective = Cx - D with constraints Ax <= B, introducing + introducing auxilliary variables, X, as necessary to make + replacements of symbols as given in r, {xi: expression with Xj}, + so all variables in x+X will take on nonnegative values. + + Every univariate condition creates a semi-infinite + condition, e.g. a single ``x <= 3`` creates the + interval ``[-oo, 3]`` while ``x <= 3`` and ``x >= 2`` + create an interval ``[2, 3]``. Variables not in a univariate + expression will take on nonnegative values. + """ + + # sympify input and collect free symbols + F = sympify(objective) + np = [sympify(i) for i in constraints] + syms = set.union(*[i.free_symbols for i in [F] + np], set()) + + # change Eq(x, y) to x - y <= 0 and y - x <= 0 + for i in range(len(np)): + if isinstance(np[i], Eq): + np[i] = np[i].lhs - np[i].rhs <= 0 + np.append(-np[i].lhs <= 0) + + # convert constraints to nonpositive expressions + _ = _rel_as_nonpos(np, syms) + if _ is None: + raise InfeasibleLPError(filldedent(""" + Inconsistent/False constraint""")) + np, r, aux = _ + + # do change of variables + F = F.xreplace(r) + np = [i.xreplace(r) for i in np] + + # convert to matrices + xx = list(ordered(syms)) + aux + A, B = linear_eq_to_matrix(np, xx) + C, D = linear_eq_to_matrix([F], xx) + return A, B, C, D, r, xx, aux + + +def _lp(min_max, f, constr): + """Return the optimization (min or max) of ``f`` with the given + constraints. All variables are unbounded unless constrained. + + If `min_max` is 'max' then the results corresponding to the + maximization of ``f`` will be returned, else the minimization. + The constraints can be given as Le, Ge or Eq expressions. + + Examples + ======== + + >>> from sympy.solvers.simplex import _lp as lp + >>> from sympy import Eq + >>> from sympy.abc import x, y, z + >>> f = x + y - 2*z + >>> c = [7*x + 4*y - 7*z <= 3, 3*x - y + 10*z <= 6] + >>> c += [i >= 0 for i in (x, y, z)] + >>> lp(min, f, c) + (-6/5, {x: 0, y: 0, z: 3/5}) + + By passing max, the maximum value for f under the constraints + is returned (if possible): + + >>> lp(max, f, c) + (3/4, {x: 0, y: 3/4, z: 0}) + + Constraints that are equalities will require that the solution + also satisfy them: + + >>> lp(max, f, c + [Eq(y - 9*x, 1)]) + (5/7, {x: 0, y: 1, z: 1/7}) + + All symbols are reported, even if they are not in the objective + function: + + >>> lp(min, x, [y + x >= 3, x >= 0]) + (0, {x: 0, y: 3}) + """ + # get the matrix components for the system expressed + # in terms of only nonnegative variables + A, B, C, D, r, xx, aux = _lp_matrices(f, constr) + + how = str(min_max).lower() + if "max" in how: + # _simplex minimizes for Ax <= B so we + # have to change the sign of the function + # and negate the optimal value returned + _o, p, d = _simplex(A, B, -C, -D) + o = -_o + elif "min" in how: + o, p, d = _simplex(A, B, C, D) + else: + raise ValueError("expecting min or max") + + # restore original variables and remove aux from p + p = dict(zip(xx, p)) + if r: # p has original symbols and auxilliary symbols + # if r has x: x - z1 use values from p to update + r = {k: v.xreplace(p) for k, v in r.items()} + # then use the actual value of x (= x - z1) in p + p.update(r) + # don't show aux + p = {k: p[k] for k in ordered(p) if k not in aux} + + # not returning dual since there may be extra constraints + # when a variable has finite bounds + return o, p + + +def lpmin(f, constr): + """return minimum of linear equation ``f`` under + linear constraints expressed using Ge, Le or Eq. + + All variables are unbounded unless constrained. + + Examples + ======== + + >>> from sympy.solvers.simplex import lpmin + >>> from sympy import Eq + >>> from sympy.abc import x, y + >>> lpmin(x, [2*x - 3*y >= -1, Eq(x + 3*y, 2), x <= 2*y]) + (1/3, {x: 1/3, y: 5/9}) + + Negative values for variables are permitted unless explicitly + excluding, so minimizing ``x`` for ``x <= 3`` is an + unbounded problem while the following has a bounded solution: + + >>> lpmin(x, [x >= 0, x <= 3]) + (0, {x: 0}) + + Without indicating that ``x`` is nonnegative, there + is no minimum for this objective: + + >>> lpmin(x, [x <= 3]) + Traceback (most recent call last): + ... + sympy.solvers.simplex.UnboundedLPError: + Objective function can assume arbitrarily large values! + + See Also + ======== + linprog, lpmax + """ + return _lp(min, f, constr) + + +def lpmax(f, constr): + """return maximum of linear equation ``f`` under + linear constraints expressed using Ge, Le or Eq. + + All variables are unbounded unless constrained. + + Examples + ======== + + >>> from sympy.solvers.simplex import lpmax + >>> from sympy import Eq + >>> from sympy.abc import x, y + >>> lpmax(x, [2*x - 3*y >= -1, Eq(x+ 3*y,2), x <= 2*y]) + (4/5, {x: 4/5, y: 2/5}) + + Negative values for variables are permitted unless explicitly + excluding: + + >>> lpmax(x, [x <= -1]) + (-1, {x: -1}) + + If a non-negative constraint is added for x, there is no + possible solution: + + >>> lpmax(x, [x <= -1, x >= 0]) + Traceback (most recent call last): + ... + sympy.solvers.simplex.InfeasibleLPError: inconsistent/False constraint + + See Also + ======== + linprog, lpmin + """ + return _lp(max, f, constr) + + +def _handle_bounds(bounds): + # introduce auxiliary variables as needed for univariate + # inequalities + + def _make_list(length: int, index_value_pairs): + li = [0] * length + for idx, val in index_value_pairs: + li[idx] = val + return li + + unbound = [] + row = [] + row2 = [] + b_len = len(bounds) + for x, (a, b) in enumerate(bounds): + if a is None and b is None: + unbound.append(x) + elif a is None: + # r[x] = b - u + b_len += 1 + row.append(_make_list(b_len, [(x, 1), (-1, 1)])) + row.append(_make_list(b_len, [(x, -1), (-1, -1)])) + row2.extend([[b], [-b]]) + elif b is None: + if a: + # r[x] = a + u + b_len += 1 + row.append(_make_list(b_len, [(x, 1), (-1, -1)])) + row.append(_make_list(b_len, [(x, -1), (-1, 1)])) + row2.extend([[a], [-a]]) + else: + # standard nonnegative relationship + pass + else: + # r[x] = u + a + b_len += 1 + row.append(_make_list(b_len, [(x, 1), (-1, -1)])) + row.append(_make_list(b_len, [(x, -1), (-1, 1)])) + # u <= b - a + row.append(_make_list(b_len, [(-1, 1)])) + row2.extend([[a], [-a], [b - a]]) + + # make change of variables for unbound variables + for x in unbound: + # r[x] = u - v + b_len += 2 + row.append(_make_list(b_len, [(x, 1), (-1, 1), (-2, -1)])) + row.append(_make_list(b_len, [(x, -1), (-1, -1), (-2, 1)])) + row2.extend([[0], [0]]) + + return Matrix([r + [0]*(b_len - len(r)) for r in row]), Matrix(row2) + + +def linprog(c, A=None, b=None, A_eq=None, b_eq=None, bounds=None): + """Return the minimization of ``c*x`` with the given + constraints ``A*x <= b`` and ``A_eq*x = b_eq``. Unless bounds + are given, variables will have nonnegative values in the solution. + + If ``A`` is not given, then the dimension of the system will + be determined by the length of ``C``. + + By default, all variables will be nonnegative. If ``bounds`` + is given as a single tuple, ``(lo, hi)``, then all variables + will be constrained to be between ``lo`` and ``hi``. Use + None for a ``lo`` or ``hi`` if it is unconstrained in the + negative or positive direction, respectively, e.g. + ``(None, 0)`` indicates nonpositive values. To set + individual ranges, pass a list with length equal to the + number of columns in ``A``, each element being a tuple; if + only a few variables take on non-default values they can be + passed as a dictionary with keys giving the corresponding + column to which the variable is assigned, e.g. ``bounds={2: + (1, 4)}`` would limit the 3rd variable to have a value in + range ``[1, 4]``. + + Examples + ======== + + >>> from sympy.solvers.simplex import linprog + >>> from sympy import symbols, Eq, linear_eq_to_matrix as M, Matrix + >>> x = x1, x2, x3, x4 = symbols('x1:5') + >>> X = Matrix(x) + >>> c, d = M(5*x2 + x3 + 4*x4 - x1, x) + >>> a, b = M([5*x2 + 2*x3 + 5*x4 - (x1 + 5)], x) + >>> aeq, beq = M([Eq(3*x2 + x4, 2), Eq(-x1 + x3 + 2*x4, 1)], x) + >>> constr = [i <= j for i,j in zip(a*X, b)] + >>> constr += [Eq(i, j) for i,j in zip(aeq*X, beq)] + >>> linprog(c, a, b, aeq, beq) + (9/2, [0, 1/2, 0, 1/2]) + >>> assert all(i.subs(dict(zip(x, _[1]))) for i in constr) + + See Also + ======== + lpmin, lpmax + """ + + ## the objective + C = Matrix(c) + if C.rows != 1 and C.cols == 1: + C = C.T + if C.rows != 1: + raise ValueError("C must be a single row.") + + ## the inequalities + if not A: + if b: + raise ValueError("A and b must both be given") + # the governing equations will be simple constraints + # on variables + A, b = zeros(0, C.cols), zeros(C.cols, 1) + else: + A, b = [Matrix(i) for i in (A, b)] + + if A.cols != C.cols: + raise ValueError("number of columns in A and C must match") + + ## the equalities + if A_eq is None: + if not b_eq is None: + raise ValueError("A_eq and b_eq must both be given") + else: + A_eq, b_eq = [Matrix(i) for i in (A_eq, b_eq)] + # if x == y then x <= y and x >= y (-x <= -y) + A = A.col_join(A_eq) + A = A.col_join(-A_eq) + b = b.col_join(b_eq) + b = b.col_join(-b_eq) + + if not (bounds is None or bounds == {} or bounds == (0, None)): + ## the bounds are interpreted + if type(bounds) is tuple and len(bounds) == 2: + bounds = [bounds] * A.cols + elif len(bounds) == A.cols and all( + type(i) is tuple and len(i) == 2 for i in bounds): + pass # individual bounds + elif type(bounds) is dict and all( + type(i) is tuple and len(i) == 2 + for i in bounds.values()): + # sparse bounds + db = bounds + bounds = [(0, None)] * A.cols + while db: + i, j = db.popitem() + bounds[i] = j # IndexError if out-of-bounds indices + else: + raise ValueError("unexpected bounds %s" % bounds) + A_, b_ = _handle_bounds(bounds) + aux = A_.cols - A.cols + if A: + A = Matrix([[A, zeros(A.rows, aux)], [A_]]) + b = b.col_join(b_) + else: + A = A_ + b = b_ + C = C.row_join(zeros(1, aux)) + else: + aux = -A.cols # set so -aux will give all cols below + + o, p, d = _simplex(A, b, C) + return o, p[:-aux] # don't include aux values + +def show_linprog(c, A=None, b=None, A_eq=None, b_eq=None, bounds=None): + from sympy import symbols + ## the objective + C = Matrix(c) + if C.rows != 1 and C.cols == 1: + C = C.T + if C.rows != 1: + raise ValueError("C must be a single row.") + + ## the inequalities + if not A: + if b: + raise ValueError("A and b must both be given") + # the governing equations will be simple constraints + # on variables + A, b = zeros(0, C.cols), zeros(C.cols, 1) + else: + A, b = [Matrix(i) for i in (A, b)] + + if A.cols != C.cols: + raise ValueError("number of columns in A and C must match") + + ## the equalities + if A_eq is None: + if not b_eq is None: + raise ValueError("A_eq and b_eq must both be given") + else: + A_eq, b_eq = [Matrix(i) for i in (A_eq, b_eq)] + + if not (bounds is None or bounds == {} or bounds == (0, None)): + ## the bounds are interpreted + if type(bounds) is tuple and len(bounds) == 2: + bounds = [bounds] * A.cols + elif len(bounds) == A.cols and all( + type(i) is tuple and len(i) == 2 for i in bounds): + pass # individual bounds + elif type(bounds) is dict and all( + type(i) is tuple and len(i) == 2 + for i in bounds.values()): + # sparse bounds + db = bounds + bounds = [(0, None)] * A.cols + while db: + i, j = db.popitem() + bounds[i] = j # IndexError if out-of-bounds indices + else: + raise ValueError("unexpected bounds %s" % bounds) + + x = Matrix(symbols('x1:%s' % (A.cols+1))) + f,c = (C*x)[0], [i<=j for i,j in zip(A*x, b)] + [Eq(i,j) for i,j in zip(A_eq*x,b_eq)] + for i, (lo, hi) in enumerate(bounds): + if lo is not None: + c.append(x[i]>=lo) + if hi is not None: + c.append(x[i]<=hi) + return f,c diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/solvers.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/solvers.py new file mode 100644 index 0000000000000000000000000000000000000000..ef621a84e34bde43a3181d2fd90e26fa7b05e968 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/solvers.py @@ -0,0 +1,3674 @@ +""" +This module contain solvers for all kinds of equations: + + - algebraic or transcendental, use solve() + + - recurrence, use rsolve() + + - differential, use dsolve() + + - nonlinear (numerically), use nsolve() + (you will need a good starting point) + +""" +from __future__ import annotations + +from sympy.core import (S, Add, Symbol, Dummy, Expr, Mul) +from sympy.core.assumptions import check_assumptions +from sympy.core.exprtools import factor_terms +from sympy.core.function import (expand_mul, expand_log, Derivative, + AppliedUndef, UndefinedFunction, nfloat, + Function, expand_power_exp, _mexpand, expand, + expand_func) +from sympy.core.logic import fuzzy_not, fuzzy_and +from sympy.core.numbers import Float, Rational, _illegal +from sympy.core.intfunc import integer_log, ilcm +from sympy.core.power import Pow +from sympy.core.relational import Eq, Ne +from sympy.core.sorting import ordered, default_sort_key +from sympy.core.sympify import sympify, _sympify +from sympy.core.traversal import preorder_traversal +from sympy.logic.boolalg import And, BooleanAtom + +from sympy.functions import (log, exp, LambertW, cos, sin, tan, acos, asin, atan, + Abs, re, im, arg, sqrt, atan2) +from sympy.functions.combinatorial.factorials import binomial +from sympy.functions.elementary.hyperbolic import HyperbolicFunction +from sympy.functions.elementary.piecewise import piecewise_fold, Piecewise +from sympy.functions.elementary.trigonometric import TrigonometricFunction +from sympy.integrals.integrals import Integral +from sympy.ntheory.factor_ import divisors +from sympy.simplify import (simplify, collect, powsimp, posify, # type: ignore + powdenest, nsimplify, denom, logcombine, sqrtdenest, fraction, + separatevars) +from sympy.simplify.sqrtdenest import sqrt_depth +from sympy.simplify.fu import TR1, TR2i, TR10, TR11 +from sympy.strategies.rl import rebuild +from sympy.matrices.exceptions import NonInvertibleMatrixError +from sympy.matrices import Matrix, zeros +from sympy.polys import roots, cancel, factor, Poly +from sympy.polys.solvers import sympy_eqs_to_ring, solve_lin_sys +from sympy.polys.polyerrors import GeneratorsNeeded, PolynomialError +from sympy.polys.polytools import gcd +from sympy.utilities.lambdify import lambdify +from sympy.utilities.misc import filldedent, debugf +from sympy.utilities.iterables import (connected_components, + generate_bell, uniq, iterable, is_sequence, subsets, flatten, sift) +from sympy.utilities.decorator import conserve_mpmath_dps + +from mpmath import findroot + +from sympy.solvers.polysys import solve_poly_system + +from types import GeneratorType +from collections import defaultdict +from itertools import combinations, product + +import warnings + + +def recast_to_symbols(eqs, symbols): + """ + Return (e, s, d) where e and s are versions of *eqs* and + *symbols* in which any non-Symbol objects in *symbols* have + been replaced with generic Dummy symbols and d is a dictionary + that can be used to restore the original expressions. + + Examples + ======== + + >>> from sympy.solvers.solvers import recast_to_symbols + >>> from sympy import symbols, Function + >>> x, y = symbols('x y') + >>> fx = Function('f')(x) + >>> eqs, syms = [fx + 1, x, y], [fx, y] + >>> e, s, d = recast_to_symbols(eqs, syms); (e, s, d) + ([_X0 + 1, x, y], [_X0, y], {_X0: f(x)}) + + The original equations and symbols can be restored using d: + + >>> assert [i.xreplace(d) for i in eqs] == eqs + >>> assert [d.get(i, i) for i in s] == syms + + """ + if not iterable(eqs) and iterable(symbols): + raise ValueError('Both eqs and symbols must be iterable') + orig = list(symbols) + symbols = list(ordered(symbols)) + swap_sym = {} + i = 0 + for s in symbols: + if not isinstance(s, Symbol) and s not in swap_sym: + swap_sym[s] = Dummy('X%d' % i) + i += 1 + new_f = [] + for i in eqs: + isubs = getattr(i, 'subs', None) + if isubs is not None: + new_f.append(isubs(swap_sym)) + else: + new_f.append(i) + restore = {v: k for k, v in swap_sym.items()} + return new_f, [swap_sym.get(i, i) for i in orig], restore + + +def _ispow(e): + """Return True if e is a Pow or is exp.""" + return isinstance(e, Expr) and (e.is_Pow or isinstance(e, exp)) + + +def _simple_dens(f, symbols): + # when checking if a denominator is zero, we can just check the + # base of powers with nonzero exponents since if the base is zero + # the power will be zero, too. To keep it simple and fast, we + # limit simplification to exponents that are Numbers + dens = set() + for d in denoms(f, symbols): + if d.is_Pow and d.exp.is_Number: + if d.exp.is_zero: + continue # foo**0 is never 0 + d = d.base + dens.add(d) + return dens + + +def denoms(eq, *symbols): + """ + Return (recursively) set of all denominators that appear in *eq* + that contain any symbol in *symbols*; if *symbols* are not + provided then all denominators will be returned. + + Examples + ======== + + >>> from sympy.solvers.solvers import denoms + >>> from sympy.abc import x, y, z + + >>> denoms(x/y) + {y} + + >>> denoms(x/(y*z)) + {y, z} + + >>> denoms(3/x + y/z) + {x, z} + + >>> denoms(x/2 + y/z) + {2, z} + + If *symbols* are provided then only denominators containing + those symbols will be returned: + + >>> denoms(1/x + 1/y + 1/z, y, z) + {y, z} + + """ + + pot = preorder_traversal(eq) + dens = set() + for p in pot: + # Here p might be Tuple or Relational + # Expr subtrees (e.g. lhs and rhs) will be traversed after by pot + if not isinstance(p, Expr): + continue + den = denom(p) + if den is S.One: + continue + dens.update(Mul.make_args(den)) + if not symbols: + return dens + elif len(symbols) == 1: + if iterable(symbols[0]): + symbols = symbols[0] + return {d for d in dens if any(s in d.free_symbols for s in symbols)} + + +def checksol(f, symbol, sol=None, **flags): + """ + Checks whether sol is a solution of equation f == 0. + + Explanation + =========== + + Input can be either a single symbol and corresponding value + or a dictionary of symbols and values. When given as a dictionary + and flag ``simplify=True``, the values in the dictionary will be + simplified. *f* can be a single equation or an iterable of equations. + A solution must satisfy all equations in *f* to be considered valid; + if a solution does not satisfy any equation, False is returned; if one or + more checks are inconclusive (and none are False) then None is returned. + + Examples + ======== + + >>> from sympy import checksol, symbols + >>> x, y = symbols('x,y') + >>> checksol(x**4 - 1, x, 1) + True + >>> checksol(x**4 - 1, x, 0) + False + >>> checksol(x**2 + y**2 - 5**2, {x: 3, y: 4}) + True + + To check if an expression is zero using ``checksol()``, pass it + as *f* and send an empty dictionary for *symbol*: + + >>> checksol(x**2 + x - x*(x + 1), {}) + True + + None is returned if ``checksol()`` could not conclude. + + flags: + 'numerical=True (default)' + do a fast numerical check if ``f`` has only one symbol. + 'minimal=True (default is False)' + a very fast, minimal testing. + 'warn=True (default is False)' + show a warning if checksol() could not conclude. + 'simplify=True (default)' + simplify solution before substituting into function and + simplify the function before trying specific simplifications + 'force=True (default is False)' + make positive all symbols without assumptions regarding sign. + + """ + from sympy.physics.units import Unit + + minimal = flags.get('minimal', False) + + if sol is not None: + sol = {symbol: sol} + elif isinstance(symbol, dict): + sol = symbol + else: + msg = 'Expecting (sym, val) or ({sym: val}, None) but got (%s, %s)' + raise ValueError(msg % (symbol, sol)) + + if iterable(f): + if not f: + raise ValueError('no functions to check') + return fuzzy_and(checksol(fi, sol, **flags) for fi in f) + + f = _sympify(f) + + if f.is_number: + return f.is_zero + + if isinstance(f, Poly): + f = f.as_expr() + elif isinstance(f, (Eq, Ne)): + if f.rhs in (S.true, S.false): + f = f.reversed + B, E = f.args + if isinstance(B, BooleanAtom): + f = f.subs(sol) + if not f.is_Boolean: + return + elif isinstance(f, Eq): + f = Add(f.lhs, -f.rhs, evaluate=False) + + if isinstance(f, BooleanAtom): + return bool(f) + elif not f.is_Relational and not f: + return True + + illegal = set(_illegal) + if any(sympify(v).atoms() & illegal for k, v in sol.items()): + return False + + attempt = -1 + numerical = flags.get('numerical', True) + while 1: + attempt += 1 + if attempt == 0: + val = f.subs(sol) + if isinstance(val, Mul): + val = val.as_independent(Unit)[0] + if val.atoms() & illegal: + return False + elif attempt == 1: + if not val.is_number: + if not val.is_constant(*list(sol.keys()), simplify=not minimal): + return False + # there are free symbols -- simple expansion might work + _, val = val.as_content_primitive() + val = _mexpand(val.as_numer_denom()[0], recursive=True) + elif attempt == 2: + if minimal: + return + if flags.get('simplify', True): + for k in sol: + sol[k] = simplify(sol[k]) + # start over without the failed expanded form, possibly + # with a simplified solution + val = simplify(f.subs(sol)) + if flags.get('force', True): + val, reps = posify(val) + # expansion may work now, so try again and check + exval = _mexpand(val, recursive=True) + if exval.is_number: + # we can decide now + val = exval + else: + # if there are no radicals and no functions then this can't be + # zero anymore -- can it? + pot = preorder_traversal(expand_mul(val)) + seen = set() + saw_pow_func = False + for p in pot: + if p in seen: + continue + seen.add(p) + if p.is_Pow and not p.exp.is_Integer: + saw_pow_func = True + elif p.is_Function: + saw_pow_func = True + elif isinstance(p, UndefinedFunction): + saw_pow_func = True + if saw_pow_func: + break + if saw_pow_func is False: + return False + if flags.get('force', True): + # don't do a zero check with the positive assumptions in place + val = val.subs(reps) + nz = fuzzy_not(val.is_zero) + if nz is not None: + # issue 5673: nz may be True even when False + # so these are just hacks to keep a false positive + # from being returned + + # HACK 1: LambertW (issue 5673) + if val.is_number and val.has(LambertW): + # don't eval this to verify solution since if we got here, + # numerical must be False + return None + + # add other HACKs here if necessary, otherwise we assume + # the nz value is correct + return not nz + break + if val.is_Rational: + return val == 0 + if numerical and val.is_number: + return (abs(val.n(18).n(12, chop=True)) < 1e-9) is S.true + + if flags.get('warn', False): + warnings.warn("\n\tWarning: could not verify solution %s." % sol) + # returns None if it can't conclude + # TODO: improve solution testing + + +def solve(f, *symbols, **flags): + r""" + Algebraically solves equations and systems of equations. + + Explanation + =========== + + Currently supported: + - polynomial + - transcendental + - piecewise combinations of the above + - systems of linear and polynomial equations + - systems containing relational expressions + - systems implied by undetermined coefficients + + Examples + ======== + + The default output varies according to the input and might + be a list (possibly empty), a dictionary, a list of + dictionaries or tuples, or an expression involving relationals. + For specifics regarding different forms of output that may appear, see :ref:`solve_output`. + Let it suffice here to say that to obtain a uniform output from + `solve` use ``dict=True`` or ``set=True`` (see below). + + >>> from sympy import solve, Poly, Eq, Matrix, Symbol + >>> from sympy.abc import x, y, z, a, b + + The expressions that are passed can be Expr, Equality, or Poly + classes (or lists of the same); a Matrix is considered to be a + list of all the elements of the matrix: + + >>> solve(x - 3, x) + [3] + >>> solve(Eq(x, 3), x) + [3] + >>> solve(Poly(x - 3), x) + [3] + >>> solve(Matrix([[x, x + y]]), x, y) == solve([x, x + y], x, y) + True + + If no symbols are indicated to be of interest and the equation is + univariate, a list of values is returned; otherwise, the keys in + a dictionary will indicate which (of all the variables used in + the expression(s)) variables and solutions were found: + + >>> solve(x**2 - 4) + [-2, 2] + >>> solve((x - a)*(y - b)) + [{a: x}, {b: y}] + >>> solve([x - 3, y - 1]) + {x: 3, y: 1} + >>> solve([x - 3, y**2 - 1]) + [{x: 3, y: -1}, {x: 3, y: 1}] + + If you pass symbols for which solutions are sought, the output will vary + depending on the number of symbols you passed, whether you are passing + a list of expressions or not, and whether a linear system was solved. + Uniform output is attained by using ``dict=True`` or ``set=True``. + + >>> #### *** feel free to skip to the stars below *** #### + >>> from sympy import TableForm + >>> h = [None, ';|;'.join(['e', 's', 'solve(e, s)', 'solve(e, s, dict=True)', + ... 'solve(e, s, set=True)']).split(';')] + >>> t = [] + >>> for e, s in [ + ... (x - y, y), + ... (x - y, [x, y]), + ... (x**2 - y, [x, y]), + ... ([x - 3, y -1], [x, y]), + ... ]: + ... how = [{}, dict(dict=True), dict(set=True)] + ... res = [solve(e, s, **f) for f in how] + ... t.append([e, '|', s, '|'] + [res[0], '|', res[1], '|', res[2]]) + ... + >>> # ******************************************************* # + >>> TableForm(t, headings=h, alignments="<") + e | s | solve(e, s) | solve(e, s, dict=True) | solve(e, s, set=True) + --------------------------------------------------------------------------------------- + x - y | y | [x] | [{y: x}] | ([y], {(x,)}) + x - y | [x, y] | [(y, y)] | [{x: y}] | ([x, y], {(y, y)}) + x**2 - y | [x, y] | [(x, x**2)] | [{y: x**2}] | ([x, y], {(x, x**2)}) + [x - 3, y - 1] | [x, y] | {x: 3, y: 1} | [{x: 3, y: 1}] | ([x, y], {(3, 1)}) + + * If any equation does not depend on the symbol(s) given, it will be + eliminated from the equation set and an answer may be given + implicitly in terms of variables that were not of interest: + + >>> solve([x - y, y - 3], x) + {x: y} + + When you pass all but one of the free symbols, an attempt + is made to find a single solution based on the method of + undetermined coefficients. If it succeeds, a dictionary of values + is returned. If you want an algebraic solutions for one + or more of the symbols, pass the expression to be solved in a list: + + >>> e = a*x + b - 2*x - 3 + >>> solve(e, [a, b]) + {a: 2, b: 3} + >>> solve([e], [a, b]) + {a: -b/x + (2*x + 3)/x} + + When there is no solution for any given symbol which will make all + expressions zero, the empty list is returned (or an empty set in + the tuple when ``set=True``): + + >>> from sympy import sqrt + >>> solve(3, x) + [] + >>> solve(x - 3, y) + [] + >>> solve(sqrt(x) + 1, x, set=True) + ([x], set()) + + When an object other than a Symbol is given as a symbol, it is + isolated algebraically and an implicit solution may be obtained. + This is mostly provided as a convenience to save you from replacing + the object with a Symbol and solving for that Symbol. It will only + work if the specified object can be replaced with a Symbol using the + subs method: + + >>> from sympy import exp, Function + >>> f = Function('f') + + >>> solve(f(x) - x, f(x)) + [x] + >>> solve(f(x).diff(x) - f(x) - x, f(x).diff(x)) + [x + f(x)] + >>> solve(f(x).diff(x) - f(x) - x, f(x)) + [-x + Derivative(f(x), x)] + >>> solve(x + exp(x)**2, exp(x), set=True) + ([exp(x)], {(-sqrt(-x),), (sqrt(-x),)}) + + >>> from sympy import Indexed, IndexedBase, Tuple + >>> A = IndexedBase('A') + >>> eqs = Tuple(A[1] + A[2] - 3, A[1] - A[2] + 1) + >>> solve(eqs, eqs.atoms(Indexed)) + {A[1]: 1, A[2]: 2} + + * To solve for a function within a derivative, use :func:`~.dsolve`. + + To solve for a symbol implicitly, use implicit=True: + + >>> solve(x + exp(x), x) + [-LambertW(1)] + >>> solve(x + exp(x), x, implicit=True) + [-exp(x)] + + It is possible to solve for anything in an expression that can be + replaced with a symbol using :obj:`~sympy.core.basic.Basic.subs`: + + >>> solve(x + 2 + sqrt(3), x + 2) + [-sqrt(3)] + >>> solve((x + 2 + sqrt(3), x + 4 + y), y, x + 2) + {y: -2 + sqrt(3), x + 2: -sqrt(3)} + + * Nothing heroic is done in this implicit solving so you may end up + with a symbol still in the solution: + + >>> eqs = (x*y + 3*y + sqrt(3), x + 4 + y) + >>> solve(eqs, y, x + 2) + {y: -sqrt(3)/(x + 3), x + 2: -2*x/(x + 3) - 6/(x + 3) + sqrt(3)/(x + 3)} + >>> solve(eqs, y*x, x) + {x: -y - 4, x*y: -3*y - sqrt(3)} + + * If you attempt to solve for a number, remember that the number + you have obtained does not necessarily mean that the value is + equivalent to the expression obtained: + + >>> solve(sqrt(2) - 1, 1) + [sqrt(2)] + >>> solve(x - y + 1, 1) # /!\ -1 is targeted, too + [x/(y - 1)] + >>> [_.subs(z, -1) for _ in solve((x - y + 1).subs(-1, z), 1)] + [-x + y] + + **Additional Examples** + + ``solve()`` with check=True (default) will run through the symbol tags to + eliminate unwanted solutions. If no assumptions are included, all possible + solutions will be returned: + + >>> x = Symbol("x") + >>> solve(x**2 - 1) + [-1, 1] + + By setting the ``positive`` flag, only one solution will be returned: + + >>> pos = Symbol("pos", positive=True) + >>> solve(pos**2 - 1) + [1] + + When the solutions are checked, those that make any denominator zero + are automatically excluded. If you do not want to exclude such solutions, + then use the check=False option: + + >>> from sympy import sin, limit + >>> solve(sin(x)/x) # 0 is excluded + [pi] + + If ``check=False``, then a solution to the numerator being zero is found + but the value of $x = 0$ is a spurious solution since $\sin(x)/x$ has the well + known limit (without discontinuity) of 1 at $x = 0$: + + >>> solve(sin(x)/x, check=False) + [0, pi] + + In the following case, however, the limit exists and is equal to the + value of $x = 0$ that is excluded when check=True: + + >>> eq = x**2*(1/x - z**2/x) + >>> solve(eq, x) + [] + >>> solve(eq, x, check=False) + [0] + >>> limit(eq, x, 0, '-') + 0 + >>> limit(eq, x, 0, '+') + 0 + + **Solving Relationships** + + When one or more expressions passed to ``solve`` is a relational, + a relational result is returned (and the ``dict`` and ``set`` flags + are ignored): + + >>> solve(x < 3) + (-oo < x) & (x < 3) + >>> solve([x < 3, x**2 > 4], x) + ((-oo < x) & (x < -2)) | ((2 < x) & (x < 3)) + >>> solve([x + y - 3, x > 3], x) + (3 < x) & (x < oo) & Eq(x, 3 - y) + + Although checking of assumptions on symbols in relationals + is not done, setting assumptions will affect how certain + relationals might automatically simplify: + + >>> solve(x**2 > 4) + ((-oo < x) & (x < -2)) | ((2 < x) & (x < oo)) + + >>> r = Symbol('r', real=True) + >>> solve(r**2 > 4) + (2 < r) | (r < -2) + + There is currently no algorithm in SymPy that allows you to use + relationships to resolve more than one variable. So the following + does not determine that ``q < 0`` (and trying to solve for ``r`` + and ``q`` will raise an error): + + >>> from sympy import symbols + >>> r, q = symbols('r, q', real=True) + >>> solve([r + q - 3, r > 3], r) + (3 < r) & Eq(r, 3 - q) + + You can directly call the routine that ``solve`` calls + when it encounters a relational: :func:`~.reduce_inequalities`. + It treats Expr like Equality. + + >>> from sympy import reduce_inequalities + >>> reduce_inequalities([x**2 - 4]) + Eq(x, -2) | Eq(x, 2) + + If each relationship contains only one symbol of interest, + the expressions can be processed for multiple symbols: + + >>> reduce_inequalities([0 <= x - 1, y < 3], [x, y]) + (-oo < y) & (1 <= x) & (x < oo) & (y < 3) + + But an error is raised if any relationship has more than one + symbol of interest: + + >>> reduce_inequalities([0 <= x*y - 1, y < 3], [x, y]) + Traceback (most recent call last): + ... + NotImplementedError: + inequality has more than one symbol of interest. + + **Disabling High-Order Explicit Solutions** + + When solving polynomial expressions, you might not want explicit solutions + (which can be quite long). If the expression is univariate, ``CRootOf`` + instances will be returned instead: + + >>> solve(x**3 - x + 1) + [-1/((-1/2 - sqrt(3)*I/2)*(3*sqrt(69)/2 + 27/2)**(1/3)) - + (-1/2 - sqrt(3)*I/2)*(3*sqrt(69)/2 + 27/2)**(1/3)/3, + -(-1/2 + sqrt(3)*I/2)*(3*sqrt(69)/2 + 27/2)**(1/3)/3 - + 1/((-1/2 + sqrt(3)*I/2)*(3*sqrt(69)/2 + 27/2)**(1/3)), + -(3*sqrt(69)/2 + 27/2)**(1/3)/3 - + 1/(3*sqrt(69)/2 + 27/2)**(1/3)] + >>> solve(x**3 - x + 1, cubics=False) + [CRootOf(x**3 - x + 1, 0), + CRootOf(x**3 - x + 1, 1), + CRootOf(x**3 - x + 1, 2)] + + If the expression is multivariate, no solution might be returned: + + >>> solve(x**3 - x + a, x, cubics=False) + [] + + Sometimes solutions will be obtained even when a flag is False because the + expression could be factored. In the following example, the equation can + be factored as the product of a linear and a quadratic factor so explicit + solutions (which did not require solving a cubic expression) are obtained: + + >>> eq = x**3 + 3*x**2 + x - 1 + >>> solve(eq, cubics=False) + [-1, -1 + sqrt(2), -sqrt(2) - 1] + + **Solving Equations Involving Radicals** + + Because of SymPy's use of the principle root, some solutions + to radical equations will be missed unless check=False: + + >>> from sympy import root + >>> eq = root(x**3 - 3*x**2, 3) + 1 - x + >>> solve(eq) + [] + >>> solve(eq, check=False) + [1/3] + + In the above example, there is only a single solution to the + equation. Other expressions will yield spurious roots which + must be checked manually; roots which give a negative argument + to odd-powered radicals will also need special checking: + + >>> from sympy import real_root, S + >>> eq = root(x, 3) - root(x, 5) + S(1)/7 + >>> solve(eq) # this gives 2 solutions but misses a 3rd + [CRootOf(7*x**5 - 7*x**3 + 1, 1)**15, + CRootOf(7*x**5 - 7*x**3 + 1, 2)**15] + >>> sol = solve(eq, check=False) + >>> [abs(eq.subs(x,i).n(2)) for i in sol] + [0.48, 0.e-110, 0.e-110, 0.052, 0.052] + + The first solution is negative so ``real_root`` must be used to see that it + satisfies the expression: + + >>> abs(real_root(eq.subs(x, sol[0])).n(2)) + 0.e-110 + + If the roots of the equation are not real then more care will be + necessary to find the roots, especially for higher order equations. + Consider the following expression: + + >>> expr = root(x, 3) - root(x, 5) + + We will construct a known value for this expression at x = 3 by selecting + the 1-th root for each radical: + + >>> expr1 = root(x, 3, 1) - root(x, 5, 1) + >>> v = expr1.subs(x, -3) + + The ``solve`` function is unable to find any exact roots to this equation: + + >>> eq = Eq(expr, v); eq1 = Eq(expr1, v) + >>> solve(eq, check=False), solve(eq1, check=False) + ([], []) + + The function ``unrad``, however, can be used to get a form of the equation + for which numerical roots can be found: + + >>> from sympy.solvers.solvers import unrad + >>> from sympy import nroots + >>> e, (p, cov) = unrad(eq) + >>> pvals = nroots(e) + >>> inversion = solve(cov, x)[0] + >>> xvals = [inversion.subs(p, i) for i in pvals] + + Although ``eq`` or ``eq1`` could have been used to find ``xvals``, the + solution can only be verified with ``expr1``: + + >>> z = expr - v + >>> [xi.n(chop=1e-9) for xi in xvals if abs(z.subs(x, xi).n()) < 1e-9] + [] + >>> z1 = expr1 - v + >>> [xi.n(chop=1e-9) for xi in xvals if abs(z1.subs(x, xi).n()) < 1e-9] + [-3.0] + + Parameters + ========== + + f : + - a single Expr or Poly that must be zero + - an Equality + - a Relational expression + - a Boolean + - iterable of one or more of the above + + symbols : (object(s) to solve for) specified as + - none given (other non-numeric objects will be used) + - single symbol + - denested list of symbols + (e.g., ``solve(f, x, y)``) + - ordered iterable of symbols + (e.g., ``solve(f, [x, y])``) + + flags : + dict=True (default is False) + Return list (perhaps empty) of solution mappings. + set=True (default is False) + Return list of symbols and set of tuple(s) of solution(s). + exclude=[] (default) + Do not try to solve for any of the free symbols in exclude; + if expressions are given, the free symbols in them will + be extracted automatically. + check=True (default) + If False, do not do any testing of solutions. This can be + useful if you want to include solutions that make any + denominator zero. + numerical=True (default) + Do a fast numerical check if *f* has only one symbol. + minimal=True (default is False) + A very fast, minimal testing. + warn=True (default is False) + Show a warning if ``checksol()`` could not conclude. + simplify=True (default) + Simplify all but polynomials of order 3 or greater before + returning them and (if check is not False) use the + general simplify function on the solutions and the + expression obtained when they are substituted into the + function which should be zero. + force=True (default is False) + Make positive all symbols without assumptions regarding sign. + rational=True (default) + Recast Floats as Rational; if this option is not used, the + system containing Floats may fail to solve because of issues + with polys. If rational=None, Floats will be recast as + rationals but the answer will be recast as Floats. If the + flag is False then nothing will be done to the Floats. + manual=True (default is False) + Do not use the polys/matrix method to solve a system of + equations, solve them one at a time as you might "manually." + implicit=True (default is False) + Allows ``solve`` to return a solution for a pattern in terms of + other functions that contain that pattern; this is only + needed if the pattern is inside of some invertible function + like cos, exp, etc. + particular=True (default is False) + Instructs ``solve`` to try to find a particular solution to + a linear system with as many zeros as possible; this is very + expensive. + quick=True (default is False; ``particular`` must be True) + Selects a fast heuristic to find a solution with many zeros + whereas a value of False uses the very slow method guaranteed + to find the largest number of zeros possible. + cubics=True (default) + Return explicit solutions when cubic expressions are encountered. + When False, quartics and quintics are disabled, too. + quartics=True (default) + Return explicit solutions when quartic expressions are encountered. + When False, quintics are disabled, too. + quintics=True (default) + Return explicit solutions (if possible) when quintic expressions + are encountered. + + See Also + ======== + + rsolve: For solving recurrence relationships + sympy.solvers.ode.dsolve: For solving differential equations + + """ + from .inequalities import reduce_inequalities + + # checking/recording flags + ########################################################################### + + # set solver types explicitly; as soon as one is False + # all the rest will be False + hints = ('cubics', 'quartics', 'quintics') + default = True + for k in hints: + default = flags.setdefault(k, bool(flags.get(k, default))) + + # allow solution to contain symbol if True: + implicit = flags.get('implicit', False) + + # record desire to see warnings + warn = flags.get('warn', False) + + # this flag will be needed for quick exits below, so record + # now -- but don't record `dict` yet since it might change + as_set = flags.get('set', False) + + # keeping track of how f was passed + bare_f = not iterable(f) + + # check flag usage for particular/quick which should only be used + # with systems of equations + if flags.get('quick', None) is not None: + if not flags.get('particular', None): + raise ValueError('when using `quick`, `particular` should be True') + if flags.get('particular', False) and bare_f: + raise ValueError(filldedent(""" + The 'particular/quick' flag is usually used with systems of + equations. Either pass your equation in a list or + consider using a solver like `diophantine` if you are + looking for a solution in integers.""")) + + # sympify everything, creating list of expressions and list of symbols + ########################################################################### + + def _sympified_list(w): + return list(map(sympify, w if iterable(w) else [w])) + f, symbols = (_sympified_list(w) for w in [f, symbols]) + + # preprocess symbol(s) + ########################################################################### + + ordered_symbols = None # were the symbols in a well defined order? + if not symbols: + # get symbols from equations + symbols = set().union(*[fi.free_symbols for fi in f]) + if len(symbols) < len(f): + for fi in f: + pot = preorder_traversal(fi) + for p in pot: + if isinstance(p, AppliedUndef): + if not as_set: + flags['dict'] = True # better show symbols + symbols.add(p) + pot.skip() # don't go any deeper + ordered_symbols = False + symbols = list(ordered(symbols)) # to make it canonical + else: + if len(symbols) == 1 and iterable(symbols[0]): + symbols = symbols[0] + ordered_symbols = symbols and is_sequence(symbols, + include=GeneratorType) + _symbols = list(uniq(symbols)) + if len(_symbols) != len(symbols): + ordered_symbols = False + symbols = list(ordered(symbols)) + else: + symbols = _symbols + + # check for duplicates + if len(symbols) != len(set(symbols)): + raise ValueError('duplicate symbols given') + # remove those not of interest + exclude = flags.pop('exclude', set()) + if exclude: + if isinstance(exclude, Expr): + exclude = [exclude] + exclude = set().union(*[e.free_symbols for e in sympify(exclude)]) + symbols = [s for s in symbols if s not in exclude] + + # preprocess equation(s) + ########################################################################### + + # automatically ignore True values + if isinstance(f, list): + f = [s for s in f if s is not S.true] + + # handle canonicalization of equation types + for i, fi in enumerate(f): + if isinstance(fi, (Eq, Ne)): + if 'ImmutableDenseMatrix' in [type(a).__name__ for a in fi.args]: + fi = fi.lhs - fi.rhs + else: + L, R = fi.args + if isinstance(R, BooleanAtom): + L, R = R, L + if isinstance(L, BooleanAtom): + if isinstance(fi, Ne): + L = ~L + if R.is_Relational: + fi = ~R if L is S.false else R + elif R.is_Symbol: + return L + elif R.is_Boolean and (~R).is_Symbol: + return ~L + else: + raise NotImplementedError(filldedent(''' + Unanticipated argument of Eq when other arg + is True or False. + ''')) + elif isinstance(fi, Eq): + fi = Add(fi.lhs, -fi.rhs, evaluate=False) + f[i] = fi + + # *** dispatch and handle as a system of relationals + # ************************************************** + if fi.is_Relational: + if len(symbols) != 1: + raise ValueError("can only solve for one symbol at a time") + if warn and symbols[0].assumptions0: + warnings.warn(filldedent(""" + \tWarning: assumptions about variable '%s' are + not handled currently.""" % symbols[0])) + return reduce_inequalities(f, symbols=symbols) + + # convert Poly to expression + if isinstance(fi, Poly): + f[i] = fi.as_expr() + + # rewrite hyperbolics in terms of exp if they have symbols of + # interest + f[i] = f[i].replace(lambda w: isinstance(w, HyperbolicFunction) and \ + w.has_free(*symbols), lambda w: w.rewrite(exp)) + + # if we have a Matrix, we need to iterate over its elements again + if f[i].is_Matrix: + try: + f[i] = f[i].as_explicit() + except ValueError: + raise ValueError( + "solve cannot handle matrices with symbolic shape." + ) + bare_f = False + f.extend(list(f[i])) + f[i] = S.Zero + + # if we can split it into real and imaginary parts then do so + freei = f[i].free_symbols + if freei and all(s.is_extended_real or s.is_imaginary for s in freei): + fr, fi = f[i].as_real_imag() + # accept as long as new re, im, arg or atan2 are not introduced + had = f[i].atoms(re, im, arg, atan2) + if fr and fi and fr != fi and not any( + i.atoms(re, im, arg, atan2) - had for i in (fr, fi)): + if bare_f: + bare_f = False + f[i: i + 1] = [fr, fi] + + # real/imag handling ----------------------------- + if any(isinstance(fi, (bool, BooleanAtom)) for fi in f): + if as_set: + return [], set() + return [] + + for i, fi in enumerate(f): + # Abs + while True: + was = fi + fi = fi.replace(Abs, lambda arg: + separatevars(Abs(arg)).rewrite(Piecewise) if arg.has(*symbols) + else Abs(arg)) + if was == fi: + break + + for e in fi.find(Abs): + if e.has(*symbols): + raise NotImplementedError('solving %s when the argument ' + 'is not real or imaginary.' % e) + + # arg + fi = fi.replace(arg, lambda a: arg(a).rewrite(atan2).rewrite(atan)) + + # save changes + f[i] = fi + + # see if re(s) or im(s) appear + freim = [fi for fi in f if fi.has(re, im)] + if freim: + irf = [] + for s in symbols: + if s.is_real or s.is_imaginary: + continue # neither re(x) nor im(x) will appear + # if re(s) or im(s) appear, the auxiliary equation must be present + if any(fi.has(re(s), im(s)) for fi in freim): + irf.append((s, re(s) + S.ImaginaryUnit*im(s))) + if irf: + for s, rhs in irf: + f = [fi.xreplace({s: rhs}) for fi in f] + [s - rhs] + symbols.extend([re(s), im(s)]) + if bare_f: + bare_f = False + flags['dict'] = True + # end of real/imag handling ----------------------------- + + # we can solve for non-symbol entities by replacing them with Dummy symbols + f, symbols, swap_sym = recast_to_symbols(f, symbols) + # this set of symbols (perhaps recast) is needed below + symset = set(symbols) + + # get rid of equations that have no symbols of interest; we don't + # try to solve them because the user didn't ask and they might be + # hard to solve; this means that solutions may be given in terms + # of the eliminated equations e.g. solve((x-y, y-3), x) -> {x: y} + newf = [] + for fi in f: + # let the solver handle equations that.. + # - have no symbols but are expressions + # - have symbols of interest + # - have no symbols of interest but are constant + # but when an expression is not constant and has no symbols of + # interest, it can't change what we obtain for a solution from + # the remaining equations so we don't include it; and if it's + # zero it can be removed and if it's not zero, there is no + # solution for the equation set as a whole + # + # The reason for doing this filtering is to allow an answer + # to be obtained to queries like solve((x - y, y), x); without + # this mod the return value is [] + ok = False + if fi.free_symbols & symset: + ok = True + else: + if fi.is_number: + if fi.is_Number: + if fi.is_zero: + continue + return [] + ok = True + else: + if fi.is_constant(): + ok = True + if ok: + newf.append(fi) + if not newf: + if as_set: + return symbols, set() + return [] + f = newf + del newf + + # mask off any Object that we aren't going to invert: Derivative, + # Integral, etc... so that solving for anything that they contain will + # give an implicit solution + seen = set() + non_inverts = set() + for fi in f: + pot = preorder_traversal(fi) + for p in pot: + if not isinstance(p, Expr) or isinstance(p, Piecewise): + pass + elif (isinstance(p, bool) or + not p.args or + p in symset or + p.is_Add or p.is_Mul or + p.is_Pow and not implicit or + p.is_Function and not implicit) and p.func not in (re, im): + continue + elif p not in seen: + seen.add(p) + if p.free_symbols & symset: + non_inverts.add(p) + else: + continue + pot.skip() + del seen + non_inverts = dict(list(zip(non_inverts, [Dummy() for _ in non_inverts]))) + f = [fi.subs(non_inverts) for fi in f] + + # Both xreplace and subs are needed below: xreplace to force substitution + # inside Derivative, subs to handle non-straightforward substitutions + non_inverts = [(v, k.xreplace(swap_sym).subs(swap_sym)) for k, v in non_inverts.items()] + + # rationalize Floats + floats = False + if flags.get('rational', True) is not False: + for i, fi in enumerate(f): + if fi.has(Float): + floats = True + f[i] = nsimplify(fi, rational=True) + + # capture any denominators before rewriting since + # they may disappear after the rewrite, e.g. issue 14779 + flags['_denominators'] = _simple_dens(f[0], symbols) + + # Any embedded piecewise functions need to be brought out to the + # top level so that the appropriate strategy gets selected. + # However, this is necessary only if one of the piecewise + # functions depends on one of the symbols we are solving for. + def _has_piecewise(e): + if e.is_Piecewise: + return e.has(*symbols) + return any(_has_piecewise(a) for a in e.args) + for i, fi in enumerate(f): + if _has_piecewise(fi): + f[i] = piecewise_fold(fi) + + # expand angles of sums; in general, expand_trig will allow + # more roots to be found but this is not a great solultion + # to not returning a parametric solution, otherwise + # many values can be returned that have a simple + # relationship between values + targs = {t for fi in f for t in fi.atoms(TrigonometricFunction)} + if len(targs) > 1: + add, other = sift(targs, lambda x: x.args[0].is_Add, binary=True) + add, other = [[i for i in l if i.has_free(*symbols)] for l in (add, other)] + trep = {} + for t in add: + a = t.args[0] + ind, dep = a.as_independent(*symbols) + if dep in symbols or -dep in symbols: + # don't let expansion expand wrt anything in ind + n = Dummy() if not ind.is_Number else ind + trep[t] = TR10(t.func(dep + n)).xreplace({n: ind}) + if other and len(other) <= 2: + base = gcd(*[i.args[0] for i in other]) if len(other) > 1 else other[0].args[0] + for i in other: + trep[i] = TR11(i, base) + f = [fi.xreplace(trep) for fi in f] + + # + # try to get a solution + ########################################################################### + if bare_f: + solution = None + if len(symbols) != 1: + solution = _solve_undetermined(f[0], symbols, flags) + if not solution: + solution = _solve(f[0], *symbols, **flags) + else: + linear, solution = _solve_system(f, symbols, **flags) + assert type(solution) is list + assert not solution or type(solution[0]) is dict, solution + # + # postprocessing + ########################################################################### + # capture as_dict flag now (as_set already captured) + as_dict = flags.get('dict', False) + + # define how solution will get unpacked + tuple_format = lambda s: [tuple([i.get(x, x) for x in symbols]) for i in s] + if as_dict or as_set: + unpack = None + elif bare_f: + if len(symbols) == 1: + unpack = lambda s: [i[symbols[0]] for i in s] + elif len(solution) == 1 and len(solution[0]) == len(symbols): + # undetermined linear coeffs solution + unpack = lambda s: s[0] + elif ordered_symbols: + unpack = tuple_format + else: + unpack = lambda s: s + else: + if solution: + if linear and len(solution) == 1: + # if you want the tuple solution for the linear + # case, use `set=True` + unpack = lambda s: s[0] + elif ordered_symbols: + unpack = tuple_format + else: + unpack = lambda s: s + else: + unpack = None + + # Restore masked-off objects + if non_inverts and type(solution) is list: + solution = [{k: v.subs(non_inverts) for k, v in s.items()} + for s in solution] + + # Restore original "symbols" if a dictionary is returned. + # This is not necessary for + # - the single univariate equation case + # since the symbol will have been removed from the solution; + # - the nonlinear poly_system since that only supports zero-dimensional + # systems and those results come back as a list + # + # ** unless there were Derivatives with the symbols, but those were handled + # above. + if swap_sym: + symbols = [swap_sym.get(k, k) for k in symbols] + for i, sol in enumerate(solution): + solution[i] = {swap_sym.get(k, k): v.subs(swap_sym) + for k, v in sol.items()} + + # Get assumptions about symbols, to filter solutions. + # Note that if assumptions about a solution can't be verified, it is still + # returned. + check = flags.get('check', True) + + # restore floats + if floats and solution and flags.get('rational', None) is None: + solution = nfloat(solution, exponent=False) + # nfloat might reveal more duplicates + solution = _remove_duplicate_solutions(solution) + + if check and solution: # assumption checking + warn = flags.get('warn', False) + got_None = [] # solutions for which one or more symbols gave None + no_False = [] # solutions for which no symbols gave False + for sol in solution: + v = fuzzy_and(check_assumptions(val, **symb.assumptions0) + for symb, val in sol.items()) + if v is False: + continue + no_False.append(sol) + if v is None: + got_None.append(sol) + + solution = no_False + if warn and got_None: + warnings.warn(filldedent(""" + \tWarning: assumptions concerning following solution(s) + cannot be checked:""" + '\n\t' + + ', '.join(str(s) for s in got_None))) + + # + # done + ########################################################################### + + if not solution: + if as_set: + return symbols, set() + return [] + + # make orderings canonical for list of dictionaries + if not as_set: # for set, no point in ordering + solution = [{k: s[k] for k in ordered(s)} for s in solution] + solution.sort(key=default_sort_key) + + if not (as_set or as_dict): + return unpack(solution) + + if as_dict: + return solution + + # set output: (symbols, {t1, t2, ...}) from list of dictionaries; + # include all symbols for those that like a verbose solution + # and to resolve any differences in dictionary keys. + # + # The set results can easily be used to make a verbose dict as + # k, v = solve(eqs, syms, set=True) + # sol = [dict(zip(k,i)) for i in v] + # + if ordered_symbols: + k = symbols # keep preferred order + else: + # just unify the symbols for which solutions were found + k = list(ordered(set(flatten(tuple(i.keys()) for i in solution)))) + return k, {tuple([s.get(ki, ki) for ki in k]) for s in solution} + + +def _solve_undetermined(g, symbols, flags): + """solve helper to return a list with one dict (solution) else None + + A direct call to solve_undetermined_coeffs is more flexible and + can return both multiple solutions and handle more than one independent + variable. Here, we have to be more cautious to keep from solving + something that does not look like an undetermined coeffs system -- + to minimize the surprise factor since singularities that cancel are not + prohibited in solve_undetermined_coeffs. + """ + if g.free_symbols - set(symbols): + sol = solve_undetermined_coeffs(g, symbols, **dict(flags, dict=True, set=None)) + if len(sol) == 1: + return sol + + +def _solve(f, *symbols, **flags): + """Return a checked solution for *f* in terms of one or more of the + symbols in the form of a list of dictionaries. + + If no method is implemented to solve the equation, a NotImplementedError + will be raised. In the case that conversion of an expression to a Poly + gives None a ValueError will be raised. + """ + + not_impl_msg = "No algorithms are implemented to solve equation %s" + + if len(symbols) != 1: + # look for solutions for desired symbols that are independent + # of symbols already solved for, e.g. if we solve for x = y + # then no symbol having x in its solution will be returned. + + # First solve for linear symbols (since that is easier and limits + # solution size) and then proceed with symbols appearing + # in a non-linear fashion. Ideally, if one is solving a single + # expression for several symbols, they would have to be + # appear in factors of an expression, but we do not here + # attempt factorization. XXX perhaps handling a Mul + # should come first in this routine whether there is + # one or several symbols. + nonlin_s = [] + got_s = set() + rhs_s = set() + result = [] + for s in symbols: + xi, v = solve_linear(f, symbols=[s]) + if xi == s: + # no need to check but we should simplify if desired + if flags.get('simplify', True): + v = simplify(v) + vfree = v.free_symbols + if vfree & got_s: + # was linear, but has redundant relationship + # e.g. x - y = 0 has y == x is redundant for x == y + # so ignore + continue + rhs_s |= vfree + got_s.add(xi) + result.append({xi: v}) + elif xi: # there might be a non-linear solution if xi is not 0 + nonlin_s.append(s) + if not nonlin_s: + return result + for s in nonlin_s: + try: + soln = _solve(f, s, **flags) + for sol in soln: + if sol[s].free_symbols & got_s: + # depends on previously solved symbols: ignore + continue + got_s.add(s) + result.append(sol) + except NotImplementedError: + continue + if got_s: + return result + else: + raise NotImplementedError(not_impl_msg % f) + + # solve f for a single variable + + symbol = symbols[0] + + # expand binomials only if it has the unknown symbol + f = f.replace(lambda e: isinstance(e, binomial) and e.has(symbol), + lambda e: expand_func(e)) + + # checking will be done unless it is turned off before making a + # recursive call; the variables `checkdens` and `check` are + # captured here (for reference below) in case flag value changes + flags['check'] = checkdens = check = flags.pop('check', True) + + # build up solutions if f is a Mul + if f.is_Mul: + result = set() + for m in f.args: + if m in {S.NegativeInfinity, S.ComplexInfinity, S.Infinity}: + result = set() + break + soln = _vsolve(m, symbol, **flags) + result.update(set(soln)) + result = [{symbol: v} for v in result] + if check: + # all solutions have been checked but now we must + # check that the solutions do not set denominators + # in any factor to zero + dens = flags.get('_denominators', _simple_dens(f, symbols)) + result = [s for s in result if + not any(checksol(den, s, **flags) for den in + dens)] + # set flags for quick exit at end; solutions for each + # factor were already checked and simplified + check = False + flags['simplify'] = False + + elif f.is_Piecewise: + result = set() + if any(e.is_zero for e, c in f.args): + f = f.simplify() # failure imminent w/o help + + cond = neg = True + for expr, cnd in f.args: + # the explicit condition for this expr is the current cond + # and none of the previous conditions + cond = And(neg, cnd) + neg = And(neg, ~cond) + + if expr.is_zero and cond.simplify() != False: + raise NotImplementedError(filldedent(''' + An expression is already zero when %s. + This means that in this *region* the solution + is zero but solve can only represent discrete, + not interval, solutions. If this is a spurious + interval it might be resolved with simplification + of the Piecewise conditions.''' % cond)) + candidates = _vsolve(expr, symbol, **flags) + + for candidate in candidates: + if candidate in result: + # an unconditional value was already there + continue + try: + v = cond.subs(symbol, candidate) + _eval_simplify = getattr(v, '_eval_simplify', None) + if _eval_simplify is not None: + # unconditionally take the simplification of v + v = _eval_simplify(ratio=2, measure=lambda x: 1) + except TypeError: + # incompatible type with condition(s) + continue + if v == False: + continue + if v == True: + result.add(candidate) + else: + result.add(Piecewise( + (candidate, v), + (S.NaN, True))) + # solutions already checked and simplified + # **************************************** + return [{symbol: r} for r in result] + else: + # first see if it really depends on symbol and whether there + # is only a linear solution + f_num, sol = solve_linear(f, symbols=symbols) + if f_num.is_zero or sol is S.NaN: + return [] + elif f_num.is_Symbol: + # no need to check but simplify if desired + if flags.get('simplify', True): + sol = simplify(sol) + return [{f_num: sol}] + + poly = None + # check for a single Add generator + if not f_num.is_Add: + add_args = [i for i in f_num.atoms(Add) + if symbol in i.free_symbols] + if len(add_args) == 1: + gen = add_args[0] + spart = gen.as_independent(symbol)[1].as_base_exp()[0] + if spart == symbol: + try: + poly = Poly(f_num, spart) + except PolynomialError: + pass + + result = False # no solution was obtained + msg = '' # there is no failure message + + # Poly is generally robust enough to convert anything to + # a polynomial and tell us the different generators that it + # contains, so we will inspect the generators identified by + # polys to figure out what to do. + + # try to identify a single generator that will allow us to solve this + # as a polynomial, followed (perhaps) by a change of variables if the + # generator is not a symbol + + try: + if poly is None: + poly = Poly(f_num) + if poly is None: + raise ValueError('could not convert %s to Poly' % f_num) + except GeneratorsNeeded: + simplified_f = simplify(f_num) + if simplified_f != f_num: + return _solve(simplified_f, symbol, **flags) + raise ValueError('expression appears to be a constant') + + gens = [g for g in poly.gens if g.has(symbol)] + + def _as_base_q(x): + """Return (b**e, q) for x = b**(p*e/q) where p/q is the leading + Rational of the exponent of x, e.g. exp(-2*x/3) -> (exp(x), 3) + """ + b, e = x.as_base_exp() + if e.is_Rational: + return b, e.q + if not e.is_Mul: + return x, 1 + c, ee = e.as_coeff_Mul() + if c.is_Rational and c is not S.One: # c could be a Float + return b**ee, c.q + return x, 1 + + if len(gens) > 1: + # If there is more than one generator, it could be that the + # generators have the same base but different powers, e.g. + # >>> Poly(exp(x) + 1/exp(x)) + # Poly(exp(-x) + exp(x), exp(-x), exp(x), domain='ZZ') + # + # If unrad was not disabled then there should be no rational + # exponents appearing as in + # >>> Poly(sqrt(x) + sqrt(sqrt(x))) + # Poly(sqrt(x) + x**(1/4), sqrt(x), x**(1/4), domain='ZZ') + + bases, qs = list(zip(*[_as_base_q(g) for g in gens])) + bases = set(bases) + + if len(bases) > 1 or not all(q == 1 for q in qs): + funcs = {b for b in bases if b.is_Function} + + trig = {_ for _ in funcs if + isinstance(_, TrigonometricFunction)} + other = funcs - trig + if not other and len(funcs.intersection(trig)) > 1: + newf = None + if f_num.is_Add and len(f_num.args) == 2: + # check for sin(x)**p = cos(x)**p + _args = f_num.args + t = a, b = [i.atoms(Function).intersection( + trig) for i in _args] + if all(len(i) == 1 for i in t): + a, b = [i.pop() for i in t] + if isinstance(a, cos): + a, b = b, a + _args = _args[::-1] + if isinstance(a, sin) and isinstance(b, cos + ) and a.args[0] == b.args[0]: + # sin(x) + cos(x) = 0 -> tan(x) + 1 = 0 + newf, _d = (TR2i(_args[0]/_args[1]) + 1 + ).as_numer_denom() + if not _d.is_Number: + newf = None + if newf is None: + newf = TR1(f_num).rewrite(tan) + if newf != f_num: + # don't check the rewritten form --check + # solutions in the un-rewritten form below + flags['check'] = False + result = _solve(newf, symbol, **flags) + flags['check'] = check + + # just a simple case - see if replacement of single function + # clears all symbol-dependent functions, e.g. + # log(x) - log(log(x) - 1) - 3 can be solved even though it has + # two generators. + + if result is False and funcs: + funcs = list(ordered(funcs)) # put shallowest function first + f1 = funcs[0] + t = Dummy('t') + # perform the substitution + ftry = f_num.subs(f1, t) + + # if no Functions left, we can proceed with usual solve + if not ftry.has(symbol): + cv_sols = _solve(ftry, t, **flags) + cv_inv = list(ordered(_vsolve(t - f1, symbol, **flags)))[0] + result = [{symbol: cv_inv.subs(sol)} for sol in cv_sols] + + if result is False: + msg = 'multiple generators %s' % gens + + else: + # e.g. case where gens are exp(x), exp(-x) + u = bases.pop() + t = Dummy('t') + inv = _vsolve(u - t, symbol, **flags) + if isinstance(u, (Pow, exp)): + # this will be resolved by factor in _tsolve but we might + # as well try a simple expansion here to get things in + # order so something like the following will work now without + # having to factor: + # + # >>> eq = (exp(I*(-x-2))+exp(I*(x+2))) + # >>> eq.subs(exp(x),y) # fails + # exp(I*(-x - 2)) + exp(I*(x + 2)) + # >>> eq.expand().subs(exp(x),y) # works + # y**I*exp(2*I) + y**(-I)*exp(-2*I) + def _expand(p): + b, e = p.as_base_exp() + e = expand_mul(e) + return expand_power_exp(b**e) + ftry = f_num.replace( + lambda w: w.is_Pow or isinstance(w, exp), + _expand).subs(u, t) + if not ftry.has(symbol): + soln = _solve(ftry, t, **flags) + result = [{symbol: i.subs(s)} for i in inv for s in soln] + + elif len(gens) == 1: + + # There is only one generator that we are interested in, but + # there may have been more than one generator identified by + # polys (e.g. for symbols other than the one we are interested + # in) so recast the poly in terms of our generator of interest. + # Also use composite=True with f_num since Poly won't update + # poly as documented in issue 8810. + + poly = Poly(f_num, gens[0], composite=True) + + # if we aren't on the tsolve-pass, use roots + if not flags.pop('tsolve', False): + soln = None + deg = poly.degree() + flags['tsolve'] = True + hints = ('cubics', 'quartics', 'quintics') + solvers = {h: flags.get(h) for h in hints} + soln = roots(poly, **solvers) + if sum(soln.values()) < deg: + # e.g. roots(32*x**5 + 400*x**4 + 2032*x**3 + + # 5000*x**2 + 6250*x + 3189) -> {} + # so all_roots is used and RootOf instances are + # returned *unless* the system is multivariate + # or high-order EX domain. + try: + soln = poly.all_roots() + except NotImplementedError: + if not flags.get('incomplete', True): + raise NotImplementedError( + filldedent(''' + Neither high-order multivariate polynomials + nor sorting of EX-domain polynomials is supported. + If you want to see any results, pass keyword incomplete=True to + solve; to see numerical values of roots + for univariate expressions, use nroots. + ''')) + else: + pass + else: + soln = list(soln.keys()) + + if soln is not None: + u = poly.gen + if u != symbol: + try: + t = Dummy('t') + inv = _vsolve(u - t, symbol, **flags) + soln = {i.subs(t, s) for i in inv for s in soln} + except NotImplementedError: + # perhaps _tsolve can handle f_num + soln = None + else: + check = False # only dens need to be checked + if soln is not None: + if len(soln) > 2: + # if the flag wasn't set then unset it since high-order + # results are quite long. Perhaps one could base this + # decision on a certain critical length of the + # roots. In addition, wester test M2 has an expression + # whose roots can be shown to be real with the + # unsimplified form of the solution whereas only one of + # the simplified forms appears to be real. + flags['simplify'] = flags.get('simplify', False) + if soln is not None: + result = [{symbol: v} for v in soln] + + # fallback if above fails + # ----------------------- + if result is False: + # try unrad + if flags.pop('_unrad', True): + try: + u = unrad(f_num, symbol) + except (ValueError, NotImplementedError): + u = False + if u: + eq, cov = u + if cov: + isym, ieq = cov + inv = _vsolve(ieq, symbol, **flags)[0] + rv = {inv.subs(xi) for xi in _solve(eq, isym, **flags)} + else: + try: + rv = set(_vsolve(eq, symbol, **flags)) + except NotImplementedError: + rv = None + if rv is not None: + result = [{symbol: v} for v in rv] + # if the flag wasn't set then unset it since unrad results + # can be quite long or of very high order + flags['simplify'] = flags.get('simplify', False) + else: + pass # for coverage + + # try _tsolve + if result is False: + flags.pop('tsolve', None) # allow tsolve to be used on next pass + try: + soln = _tsolve(f_num, symbol, **flags) + if soln is not None: + result = [{symbol: v} for v in soln] + except PolynomialError: + pass + # ----------- end of fallback ---------------------------- + + if result is False: + raise NotImplementedError('\n'.join([msg, not_impl_msg % f])) + + result = _remove_duplicate_solutions(result) + + if flags.get('simplify', True): + result = [{k: d[k].simplify() for k in d} for d in result] + # Simplification might reveal more duplicates + result = _remove_duplicate_solutions(result) + # we just simplified the solution so we now set the flag to + # False so the simplification doesn't happen again in checksol() + flags['simplify'] = False + + if checkdens: + # reject any result that makes any denom. affirmatively 0; + # if in doubt, keep it + dens = _simple_dens(f, symbols) + result = [r for r in result if + not any(checksol(d, r, **flags) + for d in dens)] + if check: + # keep only results if the check is not False + result = [r for r in result if + checksol(f_num, r, **flags) is not False] + return result + + +def _remove_duplicate_solutions(solutions: list[dict[Expr, Expr]] + ) -> list[dict[Expr, Expr]]: + """Remove duplicates from a list of dicts""" + solutions_set = set() + solutions_new = [] + + for sol in solutions: + solset = frozenset(sol.items()) + if solset not in solutions_set: + solutions_new.append(sol) + solutions_set.add(solset) + + return solutions_new + + +def _solve_system(exprs, symbols, **flags): + """return ``(linear, solution)`` where ``linear`` is True + if the system was linear, else False; ``solution`` + is a list of dictionaries giving solutions for the symbols + """ + if not exprs: + return False, [] + + if flags.pop('_split', True): + # Split the system into connected components + V = exprs + symsset = set(symbols) + exprsyms = {e: e.free_symbols & symsset for e in exprs} + E = [] + sym_indices = {sym: i for i, sym in enumerate(symbols)} + for n, e1 in enumerate(exprs): + for e2 in exprs[:n]: + # Equations are connected if they share a symbol + if exprsyms[e1] & exprsyms[e2]: + E.append((e1, e2)) + G = V, E + subexprs = connected_components(G) + if len(subexprs) > 1: + subsols = [] + linear = True + for subexpr in subexprs: + subsyms = set() + for e in subexpr: + subsyms |= exprsyms[e] + subsyms = sorted(subsyms, key = lambda x: sym_indices[x]) + flags['_split'] = False # skip split step + _linear, subsol = _solve_system(subexpr, subsyms, **flags) + if linear: + linear = linear and _linear + if not isinstance(subsol, list): + subsol = [subsol] + subsols.append(subsol) + # Full solution is cartesian product of subsystems + sols = [] + for soldicts in product(*subsols): + sols.append(dict(item for sd in soldicts + for item in sd.items())) + return linear, sols + + polys = [] + dens = set() + failed = [] + result = [] + solved_syms = [] + linear = True + manual = flags.get('manual', False) + checkdens = check = flags.get('check', True) + + for j, g in enumerate(exprs): + dens.update(_simple_dens(g, symbols)) + i, d = _invert(g, *symbols) + if d in symbols: + if linear: + linear = solve_linear(g, 0, [d])[0] == d + g = d - i + g = g.as_numer_denom()[0] + if manual: + failed.append(g) + continue + + poly = g.as_poly(*symbols, extension=True) + + if poly is not None: + polys.append(poly) + else: + failed.append(g) + + if polys: + if all(p.is_linear for p in polys): + n, m = len(polys), len(symbols) + matrix = zeros(n, m + 1) + + for i, poly in enumerate(polys): + for monom, coeff in poly.terms(): + try: + j = monom.index(1) + matrix[i, j] = coeff + except ValueError: + matrix[i, m] = -coeff + + # returns a dictionary ({symbols: values}) or None + if flags.pop('particular', False): + result = minsolve_linear_system(matrix, *symbols, **flags) + else: + result = solve_linear_system(matrix, *symbols, **flags) + result = [result] if result else [] + if failed: + if result: + solved_syms = list(result[0].keys()) # there is only one result dict + else: + solved_syms = [] + # linear doesn't change + else: + linear = False + if len(symbols) > len(polys): + + free = set().union(*[p.free_symbols for p in polys]) + free = list(ordered(free.intersection(symbols))) + got_s = set() + result = [] + for syms in subsets(free, min(len(free), len(polys))): + try: + # returns [], None or list of tuples + res = solve_poly_system(polys, *syms) + if res: + for r in set(res): + skip = False + for r1 in r: + if got_s and any(ss in r1.free_symbols + for ss in got_s): + # sol depends on previously + # solved symbols: discard it + skip = True + if not skip: + got_s.update(syms) + result.append(dict(list(zip(syms, r)))) + except NotImplementedError: + pass + if got_s: + solved_syms = list(got_s) + else: + failed.extend([g.as_expr() for g in polys]) + else: + try: + result = solve_poly_system(polys, *symbols) + if result: + solved_syms = symbols + result = [dict(list(zip(solved_syms, r))) for r in set(result)] + except NotImplementedError: + failed.extend([g.as_expr() for g in polys]) + solved_syms = [] + + # convert None or [] to [{}] + result = result or [{}] + + if failed: + linear = False + # For each failed equation, see if we can solve for one of the + # remaining symbols from that equation. If so, we update the + # solution set and continue with the next failed equation, + # repeating until we are done or we get an equation that can't + # be solved. + def _ok_syms(e, sort=False): + rv = e.free_symbols & legal + + # Solve first for symbols that have lower degree in the equation. + # Ideally we want to solve firstly for symbols that appear linearly + # with rational coefficients e.g. if e = x*y + z then we should + # solve for z first. + def key(sym): + ep = e.as_poly(sym) + if ep is None: + complexity = (S.Infinity, S.Infinity, S.Infinity) + else: + coeff_syms = ep.LC().free_symbols + complexity = (ep.degree(), len(coeff_syms & rv), len(coeff_syms)) + return complexity + (default_sort_key(sym),) + + if sort: + rv = sorted(rv, key=key) + return rv + + legal = set(symbols) # what we are interested in + # sort so equation with the fewest potential symbols is first + u = Dummy() # used in solution checking + for eq in ordered(failed, lambda _: len(_ok_syms(_))): + newresult = [] + bad_results = [] + hit = False + for r in result: + got_s = set() + # update eq with everything that is known so far + eq2 = eq.subs(r) + # if check is True then we see if it satisfies this + # equation, otherwise we just accept it + if check and r: + b = checksol(u, u, eq2, minimal=True) + if b is not None: + # this solution is sufficient to know whether + # it is valid or not so we either accept or + # reject it, then continue + if b: + newresult.append(r) + else: + bad_results.append(r) + continue + # search for a symbol amongst those available that + # can be solved for + ok_syms = _ok_syms(eq2, sort=True) + if not ok_syms: + if r: + newresult.append(r) + break # skip as it's independent of desired symbols + for s in ok_syms: + try: + soln = _vsolve(eq2, s, **flags) + except NotImplementedError: + continue + # put each solution in r and append the now-expanded + # result in the new result list; use copy since the + # solution for s is being added in-place + for sol in soln: + if got_s and any(ss in sol.free_symbols for ss in got_s): + # sol depends on previously solved symbols: discard it + continue + rnew = r.copy() + for k, v in r.items(): + rnew[k] = v.subs(s, sol) + # and add this new solution + rnew[s] = sol + # check that it is independent of previous solutions + iset = set(rnew.items()) + for i in newresult: + if len(i) < len(iset): + # update i with what is known + i_items_updated = {(k, v.xreplace(rnew)) for k, v in i.items()} + if not i_items_updated - iset: + # this is a superset of a known solution that + # is smaller + break + else: + # keep it + newresult.append(rnew) + hit = True + got_s.add(s) + if not hit: + raise NotImplementedError('could not solve %s' % eq2) + else: + result = newresult + for b in bad_results: + if b in result: + result.remove(b) + + if not result: + return False, [] + + # rely on linear/polynomial system solvers to simplify + # XXX the following tests show that the expressions + # returned are not the same as they would be if simplify + # were applied to this: + # sympy/solvers/ode/tests/test_systems/test__classify_linear_system + # sympy/solvers/tests/test_solvers/test_issue_4886 + # so the docs should be updated to reflect that or else + # the following should be `bool(failed) or not linear` + default_simplify = bool(failed) + if flags.get('simplify', default_simplify): + for r in result: + for k in r: + r[k] = simplify(r[k]) + flags['simplify'] = False # don't need to do so in checksol now + + if checkdens: + result = [r for r in result + if not any(checksol(d, r, **flags) for d in dens)] + + if check and not linear: + result = [r for r in result + if not any(checksol(e, r, **flags) is False for e in exprs)] + + result = [r for r in result if r] + return linear, result + + +def solve_linear(lhs, rhs=0, symbols=[], exclude=[]): + r""" + Return a tuple derived from ``f = lhs - rhs`` that is one of + the following: ``(0, 1)``, ``(0, 0)``, ``(symbol, solution)``, ``(n, d)``. + + Explanation + =========== + + ``(0, 1)`` meaning that ``f`` is independent of the symbols in *symbols* + that are not in *exclude*. + + ``(0, 0)`` meaning that there is no solution to the equation amongst the + symbols given. If the first element of the tuple is not zero, then the + function is guaranteed to be dependent on a symbol in *symbols*. + + ``(symbol, solution)`` where symbol appears linearly in the numerator of + ``f``, is in *symbols* (if given), and is not in *exclude* (if given). No + simplification is done to ``f`` other than a ``mul=True`` expansion, so the + solution will correspond strictly to a unique solution. + + ``(n, d)`` where ``n`` and ``d`` are the numerator and denominator of ``f`` + when the numerator was not linear in any symbol of interest; ``n`` will + never be a symbol unless a solution for that symbol was found (in which case + the second element is the solution, not the denominator). + + Examples + ======== + + >>> from sympy import cancel, Pow + + ``f`` is independent of the symbols in *symbols* that are not in + *exclude*: + + >>> from sympy import cos, sin, solve_linear + >>> from sympy.abc import x, y, z + >>> eq = y*cos(x)**2 + y*sin(x)**2 - y # = y*(1 - 1) = 0 + >>> solve_linear(eq) + (0, 1) + >>> eq = cos(x)**2 + sin(x)**2 # = 1 + >>> solve_linear(eq) + (0, 1) + >>> solve_linear(x, exclude=[x]) + (0, 1) + + The variable ``x`` appears as a linear variable in each of the + following: + + >>> solve_linear(x + y**2) + (x, -y**2) + >>> solve_linear(1/x - y**2) + (x, y**(-2)) + + When not linear in ``x`` or ``y`` then the numerator and denominator are + returned: + + >>> solve_linear(x**2/y**2 - 3) + (x**2 - 3*y**2, y**2) + + If the numerator of the expression is a symbol, then ``(0, 0)`` is + returned if the solution for that symbol would have set any + denominator to 0: + + >>> eq = 1/(1/x - 2) + >>> eq.as_numer_denom() + (x, 1 - 2*x) + >>> solve_linear(eq) + (0, 0) + + But automatic rewriting may cause a symbol in the denominator to + appear in the numerator so a solution will be returned: + + >>> (1/x)**-1 + x + >>> solve_linear((1/x)**-1) + (x, 0) + + Use an unevaluated expression to avoid this: + + >>> solve_linear(Pow(1/x, -1, evaluate=False)) + (0, 0) + + If ``x`` is allowed to cancel in the following expression, then it + appears to be linear in ``x``, but this sort of cancellation is not + done by ``solve_linear`` so the solution will always satisfy the + original expression without causing a division by zero error. + + >>> eq = x**2*(1/x - z**2/x) + >>> solve_linear(cancel(eq)) + (x, 0) + >>> solve_linear(eq) + (x**2*(1 - z**2), x) + + A list of symbols for which a solution is desired may be given: + + >>> solve_linear(x + y + z, symbols=[y]) + (y, -x - z) + + A list of symbols to ignore may also be given: + + >>> solve_linear(x + y + z, exclude=[x]) + (y, -x - z) + + (A solution for ``y`` is obtained because it is the first variable + from the canonically sorted list of symbols that had a linear + solution.) + + """ + if isinstance(lhs, Eq): + if rhs: + raise ValueError(filldedent(''' + If lhs is an Equality, rhs must be 0 but was %s''' % rhs)) + rhs = lhs.rhs + lhs = lhs.lhs + dens = None + eq = lhs - rhs + n, d = eq.as_numer_denom() + if not n: + return S.Zero, S.One + + free = n.free_symbols + if not symbols: + symbols = free + else: + bad = [s for s in symbols if not s.is_Symbol] + if bad: + if len(bad) == 1: + bad = bad[0] + if len(symbols) == 1: + eg = 'solve(%s, %s)' % (eq, symbols[0]) + else: + eg = 'solve(%s, *%s)' % (eq, list(symbols)) + raise ValueError(filldedent(''' + solve_linear only handles symbols, not %s. To isolate + non-symbols use solve, e.g. >>> %s <<<. + ''' % (bad, eg))) + symbols = free.intersection(symbols) + symbols = symbols.difference(exclude) + if not symbols: + return S.Zero, S.One + + # derivatives are easy to do but tricky to analyze to see if they + # are going to disallow a linear solution, so for simplicity we + # just evaluate the ones that have the symbols of interest + derivs = defaultdict(list) + for der in n.atoms(Derivative): + csym = der.free_symbols & symbols + for c in csym: + derivs[c].append(der) + + all_zero = True + for xi in sorted(symbols, key=default_sort_key): # canonical order + # if there are derivatives in this var, calculate them now + if isinstance(derivs[xi], list): + derivs[xi] = {der: der.doit() for der in derivs[xi]} + newn = n.subs(derivs[xi]) + dnewn_dxi = newn.diff(xi) + # dnewn_dxi can be nonzero if it survives differentation by any + # of its free symbols + free = dnewn_dxi.free_symbols + if dnewn_dxi and (not free or any(dnewn_dxi.diff(s) for s in free) or free == symbols): + all_zero = False + if dnewn_dxi is S.NaN: + break + if xi not in dnewn_dxi.free_symbols: + vi = -1/dnewn_dxi*(newn.subs(xi, 0)) + if dens is None: + dens = _simple_dens(eq, symbols) + if not any(checksol(di, {xi: vi}, minimal=True) is True + for di in dens): + # simplify any trivial integral + irep = [(i, i.doit()) for i in vi.atoms(Integral) if + i.function.is_number] + # do a slight bit of simplification + vi = expand_mul(vi.subs(irep)) + return xi, vi + if all_zero: + return S.Zero, S.One + if n.is_Symbol: # no solution for this symbol was found + return S.Zero, S.Zero + return n, d + + +def minsolve_linear_system(system, *symbols, **flags): + r""" + Find a particular solution to a linear system. + + Explanation + =========== + + In particular, try to find a solution with the minimal possible number + of non-zero variables using a naive algorithm with exponential complexity. + If ``quick=True``, a heuristic is used. + + """ + quick = flags.get('quick', False) + # Check if there are any non-zero solutions at all + s0 = solve_linear_system(system, *symbols, **flags) + if not s0 or all(v == 0 for v in s0.values()): + return s0 + if quick: + # We just solve the system and try to heuristically find a nice + # solution. + s = solve_linear_system(system, *symbols) + def update(determined, solution): + delete = [] + for k, v in solution.items(): + solution[k] = v.subs(determined) + if not solution[k].free_symbols: + delete.append(k) + determined[k] = solution[k] + for k in delete: + del solution[k] + determined = {} + update(determined, s) + while s: + # NOTE sort by default_sort_key to get deterministic result + k = max((k for k in s.values()), + key=lambda x: (len(x.free_symbols), default_sort_key(x))) + kfree = k.free_symbols + x = next(reversed(list(ordered(kfree)))) + if len(kfree) != 1: + determined[x] = S.Zero + else: + val = _vsolve(k, x, check=False)[0] + if not val and not any(v.subs(x, val) for v in s.values()): + determined[x] = S.One + else: + determined[x] = val + update(determined, s) + return determined + else: + # We try to select n variables which we want to be non-zero. + # All others will be assumed zero. We try to solve the modified system. + # If there is a non-trivial solution, just set the free variables to + # one. If we do this for increasing n, trying all combinations of + # variables, we will find an optimal solution. + # We speed up slightly by starting at one less than the number of + # variables the quick method manages. + N = len(symbols) + bestsol = minsolve_linear_system(system, *symbols, quick=True) + n0 = len([x for x in bestsol.values() if x != 0]) + for n in range(n0 - 1, 1, -1): + debugf('minsolve: %s', n) + thissol = None + for nonzeros in combinations(range(N), n): + subm = Matrix([system.col(i).T for i in nonzeros] + [system.col(-1).T]).T + s = solve_linear_system(subm, *[symbols[i] for i in nonzeros]) + if s and not all(v == 0 for v in s.values()): + subs = [(symbols[v], S.One) for v in nonzeros] + for k, v in s.items(): + s[k] = v.subs(subs) + for sym in symbols: + if sym not in s: + if symbols.index(sym) in nonzeros: + s[sym] = S.One + else: + s[sym] = S.Zero + thissol = s + break + if thissol is None: + break + bestsol = thissol + return bestsol + + +def solve_linear_system(system, *symbols, **flags): + r""" + Solve system of $N$ linear equations with $M$ variables, which means + both under- and overdetermined systems are supported. + + Explanation + =========== + + The possible number of solutions is zero, one, or infinite. Respectively, + this procedure will return None or a dictionary with solutions. In the + case of underdetermined systems, all arbitrary parameters are skipped. + This may cause a situation in which an empty dictionary is returned. + In that case, all symbols can be assigned arbitrary values. + + Input to this function is a $N\times M + 1$ matrix, which means it has + to be in augmented form. If you prefer to enter $N$ equations and $M$ + unknowns then use ``solve(Neqs, *Msymbols)`` instead. Note: a local + copy of the matrix is made by this routine so the matrix that is + passed will not be modified. + + The algorithm used here is fraction-free Gaussian elimination, + which results, after elimination, in an upper-triangular matrix. + Then solutions are found using back-substitution. This approach + is more efficient and compact than the Gauss-Jordan method. + + Examples + ======== + + >>> from sympy import Matrix, solve_linear_system + >>> from sympy.abc import x, y + + Solve the following system:: + + x + 4 y == 2 + -2 x + y == 14 + + >>> system = Matrix(( (1, 4, 2), (-2, 1, 14))) + >>> solve_linear_system(system, x, y) + {x: -6, y: 2} + + A degenerate system returns an empty dictionary: + + >>> system = Matrix(( (0,0,0), (0,0,0) )) + >>> solve_linear_system(system, x, y) + {} + + """ + assert system.shape[1] == len(symbols) + 1 + + # This is just a wrapper for solve_lin_sys + eqs = list(system * Matrix(symbols + (-1,))) + eqs, ring = sympy_eqs_to_ring(eqs, symbols) + sol = solve_lin_sys(eqs, ring, _raw=False) + if sol is not None: + sol = {sym:val for sym, val in sol.items() if sym != val} + return sol + + +def solve_undetermined_coeffs(equ, coeffs, *syms, **flags): + r""" + Solve a system of equations in $k$ parameters that is formed by + matching coefficients in variables ``coeffs`` that are on + factors dependent on the remaining variables (or those given + explicitly by ``syms``. + + Explanation + =========== + + The result of this function is a dictionary with symbolic values of those + parameters with respect to coefficients in $q$ -- empty if there + is no solution or coefficients do not appear in the equation -- else + None (if the system was not recognized). If there is more than one + solution, the solutions are passed as a list. The output can be modified using + the same semantics as for `solve` since the flags that are passed are sent + directly to `solve` so, for example the flag ``dict=True`` will always return a list + of solutions as dictionaries. + + This function accepts both Equality and Expr class instances. + The solving process is most efficient when symbols are specified + in addition to parameters to be determined, but an attempt to + determine them (if absent) will be made. If an expected solution is not + obtained (and symbols were not specified) try specifying them. + + Examples + ======== + + >>> from sympy import Eq, solve_undetermined_coeffs + >>> from sympy.abc import a, b, c, h, p, k, x, y + + >>> solve_undetermined_coeffs(Eq(a*x + a + b, x/2), [a, b], x) + {a: 1/2, b: -1/2} + >>> solve_undetermined_coeffs(a - 2, [a]) + {a: 2} + + The equation can be nonlinear in the symbols: + + >>> X, Y, Z = y, x**y, y*x**y + >>> eq = a*X + b*Y + c*Z - X - 2*Y - 3*Z + >>> coeffs = a, b, c + >>> syms = x, y + >>> solve_undetermined_coeffs(eq, coeffs, syms) + {a: 1, b: 2, c: 3} + + And the system can be nonlinear in coefficients, too, but if + there is only a single solution, it will be returned as a + dictionary: + + >>> eq = a*x**2 + b*x + c - ((x - h)**2 + 4*p*k)/4/p + >>> solve_undetermined_coeffs(eq, (h, p, k), x) + {h: -b/(2*a), k: (4*a*c - b**2)/(4*a), p: 1/(4*a)} + + Multiple solutions are always returned in a list: + + >>> solve_undetermined_coeffs(a**2*x + b - x, [a, b], x) + [{a: -1, b: 0}, {a: 1, b: 0}] + + Using flag ``dict=True`` (in keeping with semantics in :func:`~.solve`) + will force the result to always be a list with any solutions + as elements in that list. + + >>> solve_undetermined_coeffs(a*x - 2*x, [a], dict=True) + [{a: 2}] + """ + if not (coeffs and all(i.is_Symbol for i in coeffs)): + raise ValueError('must provide symbols for coeffs') + + if isinstance(equ, Eq): + eq = equ.lhs - equ.rhs + else: + eq = equ + + ceq = cancel(eq) + xeq = _mexpand(ceq.as_numer_denom()[0], recursive=True) + + free = xeq.free_symbols + coeffs = free & set(coeffs) + if not coeffs: + return ([], {}) if flags.get('set', None) else [] # solve(0, x) -> [] + + if not syms: + # e.g. A*exp(x) + B - (exp(x) + y) separated into parts that + # don't/do depend on coeffs gives + # -(exp(x) + y), A*exp(x) + B + # then see what symbols are common to both + # {x} = {x, A, B} - {x, y} + ind, dep = xeq.as_independent(*coeffs, as_Add=True) + dfree = dep.free_symbols + syms = dfree & ind.free_symbols + if not syms: + # but if the system looks like (a + b)*x + b - c + # then {} = {a, b, x} - c + # so calculate {x} = {a, b, x} - {a, b} + syms = dfree - set(coeffs) + if not syms: + syms = [Dummy()] + else: + if len(syms) == 1 and iterable(syms[0]): + syms = syms[0] + e, s, _ = recast_to_symbols([xeq], syms) + xeq = e[0] + syms = s + + # find the functional forms in which symbols appear + + gens = set(xeq.as_coefficients_dict(*syms).keys()) - {1} + cset = set(coeffs) + if any(g.has_xfree(cset) for g in gens): + return # a generator contained a coefficient symbol + + # make sure we are working with symbols for generators + + e, gens, _ = recast_to_symbols([xeq], list(gens)) + xeq = e[0] + + # collect coefficients in front of generators + + system = list(collect(xeq, gens, evaluate=False).values()) + + # get a solution + + soln = solve(system, coeffs, **flags) + + # unpack unless told otherwise if length is 1 + + settings = flags.get('dict', None) or flags.get('set', None) + if type(soln) is dict or settings or len(soln) != 1: + return soln + return soln[0] + + +def solve_linear_system_LU(matrix, syms): + """ + Solves the augmented matrix system using ``LUsolve`` and returns a + dictionary in which solutions are keyed to the symbols of *syms* as ordered. + + Explanation + =========== + + The matrix must be invertible. + + Examples + ======== + + >>> from sympy import Matrix, solve_linear_system_LU + >>> from sympy.abc import x, y, z + + >>> solve_linear_system_LU(Matrix([ + ... [1, 2, 0, 1], + ... [3, 2, 2, 1], + ... [2, 0, 0, 1]]), [x, y, z]) + {x: 1/2, y: 1/4, z: -1/2} + + See Also + ======== + + LUsolve + + """ + if matrix.rows != matrix.cols - 1: + raise ValueError("Rows should be equal to columns - 1") + A = matrix[:matrix.rows, :matrix.rows] + b = matrix[:, matrix.cols - 1:] + soln = A.LUsolve(b) + solutions = {} + for i in range(soln.rows): + solutions[syms[i]] = soln[i, 0] + return solutions + + +def det_perm(M): + """ + Return the determinant of *M* by using permutations to select factors. + + Explanation + =========== + + For sizes larger than 8 the number of permutations becomes prohibitively + large, or if there are no symbols in the matrix, it is better to use the + standard determinant routines (e.g., ``M.det()``.) + + See Also + ======== + + det_minor + det_quick + + """ + args = [] + s = True + n = M.rows + list_ = M.flat() + for perm in generate_bell(n): + fac = [] + idx = 0 + for j in perm: + fac.append(list_[idx + j]) + idx += n + term = Mul(*fac) # disaster with unevaluated Mul -- takes forever for n=7 + args.append(term if s else -term) + s = not s + return Add(*args) + + +def det_minor(M): + """ + Return the ``det(M)`` computed from minors without + introducing new nesting in products. + + See Also + ======== + + det_perm + det_quick + + """ + n = M.rows + if n == 2: + return M[0, 0]*M[1, 1] - M[1, 0]*M[0, 1] + else: + return sum((1, -1)[i % 2]*Add(*[M[0, i]*d for d in + Add.make_args(det_minor(M.minor_submatrix(0, i)))]) + if M[0, i] else S.Zero for i in range(n)) + + +def det_quick(M, method=None): + """ + Return ``det(M)`` assuming that either + there are lots of zeros or the size of the matrix + is small. If this assumption is not met, then the normal + Matrix.det function will be used with method = ``method``. + + See Also + ======== + + det_minor + det_perm + + """ + if any(i.has(Symbol) for i in M): + if M.rows < 8 and all(i.has(Symbol) for i in M): + return det_perm(M) + return det_minor(M) + else: + return M.det(method=method) if method else M.det() + + +def inv_quick(M): + """Return the inverse of ``M``, assuming that either + there are lots of zeros or the size of the matrix + is small. + """ + if not all(i.is_Number for i in M): + if not any(i.is_Number for i in M): + det = lambda _: det_perm(_) + else: + det = lambda _: det_minor(_) + else: + return M.inv() + n = M.rows + d = det(M) + if d == S.Zero: + raise NonInvertibleMatrixError("Matrix det == 0; not invertible") + ret = zeros(n) + s1 = -1 + for i in range(n): + s = s1 = -s1 + for j in range(n): + di = det(M.minor_submatrix(i, j)) + ret[j, i] = s*di/d + s = -s + return ret + + +# these are functions that have multiple inverse values per period +multi_inverses = { + sin: lambda x: (asin(x), S.Pi - asin(x)), + cos: lambda x: (acos(x), 2*S.Pi - acos(x)), +} + + +def _vsolve(e, s, **flags): + """return list of scalar values for the solution of e for symbol s""" + return [i[s] for i in _solve(e, s, **flags)] + + +def _tsolve(eq, sym, **flags): + """ + Helper for ``_solve`` that solves a transcendental equation with respect + to the given symbol. Various equations containing powers and logarithms, + can be solved. + + There is currently no guarantee that all solutions will be returned or + that a real solution will be favored over a complex one. + + Either a list of potential solutions will be returned or None will be + returned (in the case that no method was known to get a solution + for the equation). All other errors (like the inability to cast an + expression as a Poly) are unhandled. + + Examples + ======== + + >>> from sympy import log, ordered + >>> from sympy.solvers.solvers import _tsolve as tsolve + >>> from sympy.abc import x + + >>> list(ordered(tsolve(3**(2*x + 5) - 4, x))) + [-5/2 + log(2)/log(3), (-5*log(3)/2 + log(2) + I*pi)/log(3)] + + >>> tsolve(log(x) + 2*x, x) + [LambertW(2)/2] + + """ + if 'tsolve_saw' not in flags: + flags['tsolve_saw'] = [] + if eq in flags['tsolve_saw']: + return None + else: + flags['tsolve_saw'].append(eq) + + rhs, lhs = _invert(eq, sym) + + if lhs == sym: + return [rhs] + try: + if lhs.is_Add: + # it's time to try factoring; powdenest is used + # to try get powers in standard form for better factoring + f = factor(powdenest(lhs - rhs)) + if f.is_Mul: + return _vsolve(f, sym, **flags) + if rhs: + f = logcombine(lhs, force=flags.get('force', True)) + if f.count(log) != lhs.count(log): + if isinstance(f, log): + return _vsolve(f.args[0] - exp(rhs), sym, **flags) + return _tsolve(f - rhs, sym, **flags) + + elif lhs.is_Pow: + if lhs.exp.is_Integer: + if lhs - rhs != eq: + return _vsolve(lhs - rhs, sym, **flags) + + if sym not in lhs.exp.free_symbols: + return _vsolve(lhs.base - rhs**(1/lhs.exp), sym, **flags) + + # _tsolve calls this with Dummy before passing the actual number in. + if any(t.is_Dummy for t in rhs.free_symbols): + raise NotImplementedError # _tsolve will call here again... + + # a ** g(x) == 0 + if not rhs: + # f(x)**g(x) only has solutions where f(x) == 0 and g(x) != 0 at + # the same place + sol_base = _vsolve(lhs.base, sym, **flags) + return [s for s in sol_base if lhs.exp.subs(sym, s) != 0] # XXX use checksol here? + + # a ** g(x) == b + if not lhs.base.has(sym): + if lhs.base == 0: + return _vsolve(lhs.exp, sym, **flags) if rhs != 0 else [] + + # Gets most solutions... + if lhs.base == rhs.as_base_exp()[0]: + # handles case when bases are equal + sol = _vsolve(lhs.exp - rhs.as_base_exp()[1], sym, **flags) + else: + # handles cases when bases are not equal and exp + # may or may not be equal + f = exp(log(lhs.base)*lhs.exp) - exp(log(rhs)) + sol = _vsolve(f, sym, **flags) + + # Check for duplicate solutions + def equal(expr1, expr2): + _ = Dummy() + eq = checksol(expr1 - _, _, expr2) + if eq is None: + if nsimplify(expr1) != nsimplify(expr2): + return False + # they might be coincidentally the same + # so check more rigorously + eq = expr1.equals(expr2) # XXX expensive but necessary? + return eq + + # Guess a rational exponent + e_rat = nsimplify(log(abs(rhs))/log(abs(lhs.base))) + e_rat = simplify(posify(e_rat)[0]) + n, d = fraction(e_rat) + if expand(lhs.base**n - rhs**d) == 0: + sol = [s for s in sol if not equal(lhs.exp.subs(sym, s), e_rat)] + sol.extend(_vsolve(lhs.exp - e_rat, sym, **flags)) + + return list(set(sol)) + + # f(x) ** g(x) == c + else: + sol = [] + logform = lhs.exp*log(lhs.base) - log(rhs) + if logform != lhs - rhs: + try: + sol.extend(_vsolve(logform, sym, **flags)) + except NotImplementedError: + pass + + # Collect possible solutions and check with substitution later. + check = [] + if rhs == 1: + # f(x) ** g(x) = 1 -- g(x)=0 or f(x)=+-1 + check.extend(_vsolve(lhs.exp, sym, **flags)) + check.extend(_vsolve(lhs.base - 1, sym, **flags)) + check.extend(_vsolve(lhs.base + 1, sym, **flags)) + elif rhs.is_Rational: + for d in (i for i in divisors(abs(rhs.p)) if i != 1): + e, t = integer_log(rhs.p, d) + if not t: + continue # rhs.p != d**b + for s in divisors(abs(rhs.q)): + if s**e== rhs.q: + r = Rational(d, s) + check.extend(_vsolve(lhs.base - r, sym, **flags)) + check.extend(_vsolve(lhs.base + r, sym, **flags)) + check.extend(_vsolve(lhs.exp - e, sym, **flags)) + elif rhs.is_irrational: + b_l, e_l = lhs.base.as_base_exp() + n, d = (e_l*lhs.exp).as_numer_denom() + b, e = sqrtdenest(rhs).as_base_exp() + check = [sqrtdenest(i) for i in (_vsolve(lhs.base - b, sym, **flags))] + check.extend([sqrtdenest(i) for i in (_vsolve(lhs.exp - e, sym, **flags))]) + if e_l*d != 1: + check.extend(_vsolve(b_l**n - rhs**(e_l*d), sym, **flags)) + for s in check: + ok = checksol(eq, sym, s) + if ok is None: + ok = eq.subs(sym, s).equals(0) + if ok: + sol.append(s) + return list(set(sol)) + + elif lhs.is_Function and len(lhs.args) == 1: + if lhs.func in multi_inverses: + # sin(x) = 1/3 -> x - asin(1/3) & x - (pi - asin(1/3)) + soln = [] + for i in multi_inverses[type(lhs)](rhs): + soln.extend(_vsolve(lhs.args[0] - i, sym, **flags)) + return list(set(soln)) + elif lhs.func == LambertW: + return _vsolve(lhs.args[0] - rhs*exp(rhs), sym, **flags) + + rewrite = lhs.rewrite(exp) + rewrite = rebuild(rewrite) # avoid rewrites involving evaluate=False + if rewrite != lhs: + return _vsolve(rewrite - rhs, sym, **flags) + except NotImplementedError: + pass + + # maybe it is a lambert pattern + if flags.pop('bivariate', True): + # lambert forms may need some help being recognized, e.g. changing + # 2**(3*x) + x**3*log(2)**3 + 3*x**2*log(2)**2 + 3*x*log(2) + 1 + # to 2**(3*x) + (x*log(2) + 1)**3 + + # make generator in log have exponent of 1 + logs = eq.atoms(log) + spow = min( + {i.exp for j in logs for i in j.atoms(Pow) + if i.base == sym} or {1}) + if spow != 1: + p = sym**spow + u = Dummy('bivariate-cov') + ueq = eq.subs(p, u) + if not ueq.has_free(sym): + sol = _vsolve(ueq, u, **flags) + inv = _vsolve(p - u, sym) + return [i.subs(u, s) for i in inv for s in sol] + + g = _filtered_gens(eq.as_poly(), sym) + up_or_log = set() + for gi in g: + if isinstance(gi, (exp, log)) or (gi.is_Pow and gi.base == S.Exp1): + up_or_log.add(gi) + elif gi.is_Pow: + gisimp = powdenest(expand_power_exp(gi)) + if gisimp.is_Pow and sym in gisimp.exp.free_symbols: + up_or_log.add(gi) + eq_down = expand_log(expand_power_exp(eq)).subs( + dict(list(zip(up_or_log, [0]*len(up_or_log))))) + eq = expand_power_exp(factor(eq_down, deep=True) + (eq - eq_down)) + rhs, lhs = _invert(eq, sym) + if lhs.has(sym): + try: + poly = lhs.as_poly() + g = _filtered_gens(poly, sym) + _eq = lhs - rhs + sols = _solve_lambert(_eq, sym, g) + # use a simplified form if it satisfies eq + # and has fewer operations + for n, s in enumerate(sols): + ns = nsimplify(s) + if ns != s and ns.count_ops() <= s.count_ops(): + ok = checksol(_eq, sym, ns) + if ok is None: + ok = _eq.subs(sym, ns).equals(0) + if ok: + sols[n] = ns + return sols + except NotImplementedError: + # maybe it's a convoluted function + if len(g) == 2: + try: + gpu = bivariate_type(lhs - rhs, *g) + if gpu is None: + raise NotImplementedError + g, p, u = gpu + flags['bivariate'] = False + inversion = _tsolve(g - u, sym, **flags) + if inversion: + sol = _vsolve(p, u, **flags) + return list({i.subs(u, s) + for i in inversion for s in sol}) + except NotImplementedError: + pass + else: + pass + + if flags.pop('force', True): + flags['force'] = False + pos, reps = posify(lhs - rhs) + if rhs == S.ComplexInfinity: + return [] + for u, s in reps.items(): + if s == sym: + break + else: + u = sym + if pos.has(u): + try: + soln = _vsolve(pos, u, **flags) + return [s.subs(reps) for s in soln] + except NotImplementedError: + pass + else: + pass # here for coverage + + return # here for coverage + + +# TODO: option for calculating J numerically + +@conserve_mpmath_dps +def nsolve(*args, dict=False, **kwargs): + r""" + Solve a nonlinear equation system numerically: ``nsolve(f, [args,] x0, + modules=['mpmath'], **kwargs)``. + + Explanation + =========== + + ``f`` is a vector function of symbolic expressions representing the system. + *args* are the variables. If there is only one variable, this argument can + be omitted. ``x0`` is a starting vector close to a solution. + + Use the modules keyword to specify which modules should be used to + evaluate the function and the Jacobian matrix. Make sure to use a module + that supports matrices. For more information on the syntax, please see the + docstring of ``lambdify``. + + If the keyword arguments contain ``dict=True`` (default is False) ``nsolve`` + will return a list (perhaps empty) of solution mappings. This might be + especially useful if you want to use ``nsolve`` as a fallback to solve since + using the dict argument for both methods produces return values of + consistent type structure. Please note: to keep this consistent with + ``solve``, the solution will be returned in a list even though ``nsolve`` + (currently at least) only finds one solution at a time. + + Overdetermined systems are supported. + + Examples + ======== + + >>> from sympy import Symbol, nsolve + >>> import mpmath + >>> mpmath.mp.dps = 15 + >>> x1 = Symbol('x1') + >>> x2 = Symbol('x2') + >>> f1 = 3 * x1**2 - 2 * x2**2 - 1 + >>> f2 = x1**2 - 2 * x1 + x2**2 + 2 * x2 - 8 + >>> print(nsolve((f1, f2), (x1, x2), (-1, 1))) + Matrix([[-1.19287309935246], [1.27844411169911]]) + + For one-dimensional functions the syntax is simplified: + + >>> from sympy import sin, nsolve + >>> from sympy.abc import x + >>> nsolve(sin(x), x, 2) + 3.14159265358979 + >>> nsolve(sin(x), 2) + 3.14159265358979 + + To solve with higher precision than the default, use the prec argument: + + >>> from sympy import cos + >>> nsolve(cos(x) - x, 1) + 0.739085133215161 + >>> nsolve(cos(x) - x, 1, prec=50) + 0.73908513321516064165531208767387340401341175890076 + >>> cos(_) + 0.73908513321516064165531208767387340401341175890076 + + To solve for complex roots of real functions, a nonreal initial point + must be specified: + + >>> from sympy import I + >>> nsolve(x**2 + 2, I) + 1.4142135623731*I + + ``mpmath.findroot`` is used and you can find their more extensive + documentation, especially concerning keyword parameters and + available solvers. Note, however, that functions which are very + steep near the root, the verification of the solution may fail. In + this case you should use the flag ``verify=False`` and + independently verify the solution. + + >>> from sympy import cos, cosh + >>> f = cos(x)*cosh(x) - 1 + >>> nsolve(f, 3.14*100) + Traceback (most recent call last): + ... + ValueError: Could not find root within given tolerance. (1.39267e+230 > 2.1684e-19) + >>> ans = nsolve(f, 3.14*100, verify=False); ans + 312.588469032184 + >>> f.subs(x, ans).n(2) + 2.1e+121 + >>> (f/f.diff(x)).subs(x, ans).n(2) + 7.4e-15 + + One might safely skip the verification if bounds of the root are known + and a bisection method is used: + + >>> bounds = lambda i: (3.14*i, 3.14*(i + 1)) + >>> nsolve(f, bounds(100), solver='bisect', verify=False) + 315.730061685774 + + Alternatively, a function may be better behaved when the + denominator is ignored. Since this is not always the case, however, + the decision of what function to use is left to the discretion of + the user. + + >>> eq = x**2/(1 - x)/(1 - 2*x)**2 - 100 + >>> nsolve(eq, 0.46) + Traceback (most recent call last): + ... + ValueError: Could not find root within given tolerance. (10000 > 2.1684e-19) + Try another starting point or tweak arguments. + >>> nsolve(eq.as_numer_denom()[0], 0.46) + 0.46792545969349058 + + """ + # there are several other SymPy functions that use method= so + # guard against that here + if 'method' in kwargs: + raise ValueError(filldedent(''' + Keyword "method" should not be used in this context. When using + some mpmath solvers directly, the keyword "method" is + used, but when using nsolve (and findroot) the keyword to use is + "solver".''')) + + if 'prec' in kwargs: + import mpmath + mpmath.mp.dps = kwargs.pop('prec') + + # keyword argument to return result as a dictionary + as_dict = dict + from builtins import dict # to unhide the builtin + + # interpret arguments + if len(args) == 3: + f = args[0] + fargs = args[1] + x0 = args[2] + if iterable(fargs) and iterable(x0): + if len(x0) != len(fargs): + raise TypeError('nsolve expected exactly %i guess vectors, got %i' + % (len(fargs), len(x0))) + elif len(args) == 2: + f = args[0] + fargs = None + x0 = args[1] + if iterable(f): + raise TypeError('nsolve expected 3 arguments, got 2') + elif len(args) < 2: + raise TypeError('nsolve expected at least 2 arguments, got %i' + % len(args)) + else: + raise TypeError('nsolve expected at most 3 arguments, got %i' + % len(args)) + modules = kwargs.get('modules', ['mpmath']) + if iterable(f): + f = list(f) + for i, fi in enumerate(f): + if isinstance(fi, Eq): + f[i] = fi.lhs - fi.rhs + f = Matrix(f).T + if iterable(x0): + x0 = list(x0) + if not isinstance(f, Matrix): + # assume it's a SymPy expression + if isinstance(f, Eq): + f = f.lhs - f.rhs + elif f.is_Relational: + raise TypeError('nsolve cannot accept inequalities') + syms = f.free_symbols + if fargs is None: + fargs = syms.copy().pop() + if not (len(syms) == 1 and (fargs in syms or fargs[0] in syms)): + raise ValueError(filldedent(''' + expected a one-dimensional and numerical function''')) + + # the function is much better behaved if there is no denominator + # but sending the numerator is left to the user since sometimes + # the function is better behaved when the denominator is present + # e.g., issue 11768 + + f = lambdify(fargs, f, modules) + x = sympify(findroot(f, x0, **kwargs)) + if as_dict: + return [{fargs: x}] + return x + + if len(fargs) > f.cols: + raise NotImplementedError(filldedent(''' + need at least as many equations as variables''')) + verbose = kwargs.get('verbose', False) + if verbose: + print('f(x):') + print(f) + # derive Jacobian + J = f.jacobian(fargs) + if verbose: + print('J(x):') + print(J) + # create functions + f = lambdify(fargs, f.T, modules) + J = lambdify(fargs, J, modules) + # solve the system numerically + x = findroot(f, x0, J=J, **kwargs) + if as_dict: + return [dict(zip(fargs, [sympify(xi) for xi in x]))] + return Matrix(x) + + +def _invert(eq, *symbols, **kwargs): + """ + Return tuple (i, d) where ``i`` is independent of *symbols* and ``d`` + contains symbols. + + Explanation + =========== + + ``i`` and ``d`` are obtained after recursively using algebraic inversion + until an uninvertible ``d`` remains. If there are no free symbols then + ``d`` will be zero. Some (but not necessarily all) solutions to the + expression ``i - d`` will be related to the solutions of the original + expression. + + Examples + ======== + + >>> from sympy.solvers.solvers import _invert as invert + >>> from sympy import sqrt, cos + >>> from sympy.abc import x, y + >>> invert(x - 3) + (3, x) + >>> invert(3) + (3, 0) + >>> invert(2*cos(x) - 1) + (1/2, cos(x)) + >>> invert(sqrt(x) - 3) + (3, sqrt(x)) + >>> invert(sqrt(x) + y, x) + (-y, sqrt(x)) + >>> invert(sqrt(x) + y, y) + (-sqrt(x), y) + >>> invert(sqrt(x) + y, x, y) + (0, sqrt(x) + y) + + If there is more than one symbol in a power's base and the exponent + is not an Integer, then the principal root will be used for the + inversion: + + >>> invert(sqrt(x + y) - 2) + (4, x + y) + >>> invert(sqrt(x + y) + 2) # note +2 instead of -2 + (4, x + y) + + If the exponent is an Integer, setting ``integer_power`` to True + will force the principal root to be selected: + + >>> invert(x**2 - 4, integer_power=True) + (2, x) + + """ + eq = sympify(eq) + if eq.args: + # make sure we are working with flat eq + eq = eq.func(*eq.args) + free = eq.free_symbols + if not symbols: + symbols = free + if not free & set(symbols): + return eq, S.Zero + + dointpow = bool(kwargs.get('integer_power', False)) + + lhs = eq + rhs = S.Zero + while True: + was = lhs + while True: + indep, dep = lhs.as_independent(*symbols) + + # dep + indep == rhs + if lhs.is_Add: + # this indicates we have done it all + if indep.is_zero: + break + + lhs = dep + rhs -= indep + + # dep * indep == rhs + else: + # this indicates we have done it all + if indep is S.One: + break + + lhs = dep + rhs /= indep + + # collect like-terms in symbols + if lhs.is_Add: + terms = {} + for a in lhs.args: + i, d = a.as_independent(*symbols) + terms.setdefault(d, []).append(i) + if any(len(v) > 1 for v in terms.values()): + args = [] + for d, i in terms.items(): + if len(i) > 1: + args.append(Add(*i)*d) + else: + args.append(i[0]*d) + lhs = Add(*args) + + # if it's a two-term Add with rhs = 0 and two powers we can get the + # dependent terms together, e.g. 3*f(x) + 2*g(x) -> f(x)/g(x) = -2/3 + if lhs.is_Add and not rhs and len(lhs.args) == 2 and \ + not lhs.is_polynomial(*symbols): + a, b = ordered(lhs.args) + ai, ad = a.as_independent(*symbols) + bi, bd = b.as_independent(*symbols) + if any(_ispow(i) for i in (ad, bd)): + a_base, a_exp = ad.as_base_exp() + b_base, b_exp = bd.as_base_exp() + if a_base == b_base and a_exp.extract_additively(b_exp) is None: + # a = -b and exponents do not have canceling terms/factors + # e.g. if exponents were 3*x and x then the ratio would have + # an exponent of 2*x: one of the roots would be lost + rat = powsimp(powdenest(ad/bd)) + lhs = rat + rhs = -bi/ai + else: + rat = ad/bd + _lhs = powsimp(ad/bd) + if _lhs != rat: + lhs = _lhs + rhs = -bi/ai + elif ai == -bi: + if isinstance(ad, Function) and ad.func == bd.func: + if len(ad.args) == len(bd.args) == 1: + lhs = ad.args[0] - bd.args[0] + elif len(ad.args) == len(bd.args): + # should be able to solve + # f(x, y) - f(2 - x, 0) == 0 -> x == 1 + raise NotImplementedError( + 'equal function with more than 1 argument') + else: + raise ValueError( + 'function with different numbers of args') + + elif lhs.is_Mul and any(_ispow(a) for a in lhs.args): + lhs = powsimp(powdenest(lhs)) + + if lhs.is_Function: + if hasattr(lhs, 'inverse') and lhs.inverse() is not None and len(lhs.args) == 1: + # -1 + # f(x) = g -> x = f (g) + # + # /!\ inverse should not be defined if there are multiple values + # for the function -- these are handled in _tsolve + # + rhs = lhs.inverse()(rhs) + lhs = lhs.args[0] + elif isinstance(lhs, atan2): + y, x = lhs.args + lhs = 2*atan(y/(sqrt(x**2 + y**2) + x)) + elif lhs.func == rhs.func: + if len(lhs.args) == len(rhs.args) == 1: + lhs = lhs.args[0] + rhs = rhs.args[0] + elif len(lhs.args) == len(rhs.args): + # should be able to solve + # f(x, y) == f(2, 3) -> x == 2 + # f(x, x + y) == f(2, 3) -> x == 2 + raise NotImplementedError( + 'equal function with more than 1 argument') + else: + raise ValueError( + 'function with different numbers of args') + + + if rhs and lhs.is_Pow and lhs.exp.is_Integer and lhs.exp < 0: + lhs = 1/lhs + rhs = 1/rhs + + # base**a = b -> base = b**(1/a) if + # a is an Integer and dointpow=True (this gives real branch of root) + # a is not an Integer and the equation is multivariate and the + # base has more than 1 symbol in it + # The rationale for this is that right now the multi-system solvers + # doesn't try to resolve generators to see, for example, if the whole + # system is written in terms of sqrt(x + y) so it will just fail, so we + # do that step here. + if lhs.is_Pow and ( + lhs.exp.is_Integer and dointpow or not lhs.exp.is_Integer and + len(symbols) > 1 and len(lhs.base.free_symbols & set(symbols)) > 1): + rhs = rhs**(1/lhs.exp) + lhs = lhs.base + + if lhs == was: + break + return rhs, lhs + + +def unrad(eq, *syms, **flags): + """ + Remove radicals with symbolic arguments and return (eq, cov), + None, or raise an error. + + Explanation + =========== + + None is returned if there are no radicals to remove. + + NotImplementedError is raised if there are radicals and they cannot be + removed or if the relationship between the original symbols and the + change of variable needed to rewrite the system as a polynomial cannot + be solved. + + Otherwise the tuple, ``(eq, cov)``, is returned where: + + *eq*, ``cov`` + *eq* is an equation without radicals (in the symbol(s) of + interest) whose solutions are a superset of the solutions to the + original expression. *eq* might be rewritten in terms of a new + variable; the relationship to the original variables is given by + ``cov`` which is a list containing ``v`` and ``v**p - b`` where + ``p`` is the power needed to clear the radical and ``b`` is the + radical now expressed as a polynomial in the symbols of interest. + For example, for sqrt(2 - x) the tuple would be + ``(c, c**2 - 2 + x)``. The solutions of *eq* will contain + solutions to the original equation (if there are any). + + *syms* + An iterable of symbols which, if provided, will limit the focus of + radical removal: only radicals with one or more of the symbols of + interest will be cleared. All free symbols are used if *syms* is not + set. + + *flags* are used internally for communication during recursive calls. + Two options are also recognized: + + ``take``, when defined, is interpreted as a single-argument function + that returns True if a given Pow should be handled. + + Radicals can be removed from an expression if: + + * All bases of the radicals are the same; a change of variables is + done in this case. + * If all radicals appear in one term of the expression. + * There are only four terms with sqrt() factors or there are less than + four terms having sqrt() factors. + * There are only two terms with radicals. + + Examples + ======== + + >>> from sympy.solvers.solvers import unrad + >>> from sympy.abc import x + >>> from sympy import sqrt, Rational, root + + >>> unrad(sqrt(x)*x**Rational(1, 3) + 2) + (x**5 - 64, []) + >>> unrad(sqrt(x) + root(x + 1, 3)) + (-x**3 + x**2 + 2*x + 1, []) + >>> eq = sqrt(x) + root(x, 3) - 2 + >>> unrad(eq) + (_p**3 + _p**2 - 2, [_p, _p**6 - x]) + + """ + + uflags = {"check": False, "simplify": False} + + def _cov(p, e): + if cov: + # XXX - uncovered + oldp, olde = cov + if Poly(e, p).degree(p) in (1, 2): + cov[:] = [p, olde.subs(oldp, _vsolve(e, p, **uflags)[0])] + else: + raise NotImplementedError + else: + cov[:] = [p, e] + + def _canonical(eq, cov): + if cov: + # change symbol to vanilla so no solutions are eliminated + p, e = cov + rep = {p: Dummy(p.name)} + eq = eq.xreplace(rep) + cov = [p.xreplace(rep), e.xreplace(rep)] + + # remove constants and powers of factors since these don't change + # the location of the root; XXX should factor or factor_terms be used? + eq = factor_terms(_mexpand(eq.as_numer_denom()[0], recursive=True), clear=True) + if eq.is_Mul: + args = [] + for f in eq.args: + if f.is_number: + continue + if f.is_Pow: + args.append(f.base) + else: + args.append(f) + eq = Mul(*args) # leave as Mul for more efficient solving + + # make the sign canonical + margs = list(Mul.make_args(eq)) + changed = False + for i, m in enumerate(margs): + if m.could_extract_minus_sign(): + margs[i] = -m + changed = True + if changed: + eq = Mul(*margs, evaluate=False) + + return eq, cov + + def _Q(pow): + # return leading Rational of denominator of Pow's exponent + c = pow.as_base_exp()[1].as_coeff_Mul()[0] + if not c.is_Rational: + return S.One + return c.q + + # define the _take method that will determine whether a term is of interest + def _take(d): + # return True if coefficient of any factor's exponent's den is not 1 + for pow in Mul.make_args(d): + if not pow.is_Pow: + continue + if _Q(pow) == 1: + continue + if pow.free_symbols & syms: + return True + return False + _take = flags.setdefault('_take', _take) + + if isinstance(eq, Eq): + eq = eq.lhs - eq.rhs # XXX legacy Eq as Eqn support + elif not isinstance(eq, Expr): + return + + cov, nwas, rpt = [flags.setdefault(k, v) for k, v in + sorted({"cov": [], "n": None, "rpt": 0}.items())] + + # preconditioning + eq = powdenest(factor_terms(eq, radical=True, clear=True)) + eq = eq.as_numer_denom()[0] + eq = _mexpand(eq, recursive=True) + if eq.is_number: + return + + # see if there are radicals in symbols of interest + syms = set(syms) or eq.free_symbols # _take uses this + poly = eq.as_poly() + gens = [g for g in poly.gens if _take(g)] + if not gens: + return + + # recast poly in terms of eigen-gens + poly = eq.as_poly(*gens) + + # not a polynomial e.g. 1 + sqrt(x)*exp(sqrt(x)) with gen sqrt(x) + if poly is None: + return + + # - an exponent has a symbol of interest (don't handle) + if any(g.exp.has(*syms) for g in gens): + return + + def _rads_bases_lcm(poly): + # if all the bases are the same or all the radicals are in one + # term, `lcm` will be the lcm of the denominators of the + # exponents of the radicals + lcm = 1 + rads = set() + bases = set() + for g in poly.gens: + q = _Q(g) + if q != 1: + rads.add(g) + lcm = ilcm(lcm, q) + bases.add(g.base) + return rads, bases, lcm + rads, bases, lcm = _rads_bases_lcm(poly) + + covsym = Dummy('p', nonnegative=True) + + # only keep in syms symbols that actually appear in radicals; + # and update gens + newsyms = set() + for r in rads: + newsyms.update(syms & r.free_symbols) + if newsyms != syms: + syms = newsyms + # get terms together that have common generators + drad = dict(zip(rads, range(len(rads)))) + rterms = {(): []} + args = Add.make_args(poly.as_expr()) + for t in args: + if _take(t): + common = set(t.as_poly().gens).intersection(rads) + key = tuple(sorted([drad[i] for i in common])) + else: + key = () + rterms.setdefault(key, []).append(t) + others = Add(*rterms.pop(())) + rterms = [Add(*rterms[k]) for k in rterms.keys()] + + # the output will depend on the order terms are processed, so + # make it canonical quickly + rterms = list(reversed(list(ordered(rterms)))) + + ok = False # we don't have a solution yet + depth = sqrt_depth(eq) + + if len(rterms) == 1 and not (rterms[0].is_Add and lcm > 2): + eq = rterms[0]**lcm - ((-others)**lcm) + ok = True + else: + if len(rterms) == 1 and rterms[0].is_Add: + rterms = list(rterms[0].args) + if len(bases) == 1: + b = bases.pop() + if len(syms) > 1: + x = b.free_symbols + else: + x = syms + x = list(ordered(x))[0] + try: + inv = _vsolve(covsym**lcm - b, x, **uflags) + if not inv: + raise NotImplementedError + eq = poly.as_expr().subs(b, covsym**lcm).subs(x, inv[0]) + _cov(covsym, covsym**lcm - b) + return _canonical(eq, cov) + except NotImplementedError: + pass + + if len(rterms) == 2: + if not others: + eq = rterms[0]**lcm - (-rterms[1])**lcm + ok = True + elif not log(lcm, 2).is_Integer: + # the lcm-is-power-of-two case is handled below + r0, r1 = rterms + if flags.get('_reverse', False): + r1, r0 = r0, r1 + i0 = _rads0, _bases0, lcm0 = _rads_bases_lcm(r0.as_poly()) + i1 = _rads1, _bases1, lcm1 = _rads_bases_lcm(r1.as_poly()) + for reverse in range(2): + if reverse: + i0, i1 = i1, i0 + r0, r1 = r1, r0 + _rads1, _, lcm1 = i1 + _rads1 = Mul(*_rads1) + t1 = _rads1**lcm1 + c = covsym**lcm1 - t1 + for x in syms: + try: + sol = _vsolve(c, x, **uflags) + if not sol: + raise NotImplementedError + neweq = r0.subs(x, sol[0]) + covsym*r1/_rads1 + \ + others + tmp = unrad(neweq, covsym) + if tmp: + eq, newcov = tmp + if newcov: + newp, newc = newcov + _cov(newp, c.subs(covsym, + _vsolve(newc, covsym, **uflags)[0])) + else: + _cov(covsym, c) + else: + eq = neweq + _cov(covsym, c) + ok = True + break + except NotImplementedError: + if reverse: + raise NotImplementedError( + 'no successful change of variable found') + else: + pass + if ok: + break + elif len(rterms) == 3: + # two cube roots and another with order less than 5 + # (so an analytical solution can be found) or a base + # that matches one of the cube root bases + info = [_rads_bases_lcm(i.as_poly()) for i in rterms] + RAD = 0 + BASES = 1 + LCM = 2 + if info[0][LCM] != 3: + info.append(info.pop(0)) + rterms.append(rterms.pop(0)) + elif info[1][LCM] != 3: + info.append(info.pop(1)) + rterms.append(rterms.pop(1)) + if info[0][LCM] == info[1][LCM] == 3: + if info[1][BASES] != info[2][BASES]: + info[0], info[1] = info[1], info[0] + rterms[0], rterms[1] = rterms[1], rterms[0] + if info[1][BASES] == info[2][BASES]: + eq = rterms[0]**3 + (rterms[1] + rterms[2] + others)**3 + ok = True + elif info[2][LCM] < 5: + # a*root(A, 3) + b*root(B, 3) + others = c + a, b, c, d, A, B = [Dummy(i) for i in 'abcdAB'] + # zz represents the unraded expression into which the + # specifics for this case are substituted + zz = (c - d)*(A**3*a**9 + 3*A**2*B*a**6*b**3 - + 3*A**2*a**6*c**3 + 9*A**2*a**6*c**2*d - 9*A**2*a**6*c*d**2 + + 3*A**2*a**6*d**3 + 3*A*B**2*a**3*b**6 + 21*A*B*a**3*b**3*c**3 - + 63*A*B*a**3*b**3*c**2*d + 63*A*B*a**3*b**3*c*d**2 - + 21*A*B*a**3*b**3*d**3 + 3*A*a**3*c**6 - 18*A*a**3*c**5*d + + 45*A*a**3*c**4*d**2 - 60*A*a**3*c**3*d**3 + 45*A*a**3*c**2*d**4 - + 18*A*a**3*c*d**5 + 3*A*a**3*d**6 + B**3*b**9 - 3*B**2*b**6*c**3 + + 9*B**2*b**6*c**2*d - 9*B**2*b**6*c*d**2 + 3*B**2*b**6*d**3 + + 3*B*b**3*c**6 - 18*B*b**3*c**5*d + 45*B*b**3*c**4*d**2 - + 60*B*b**3*c**3*d**3 + 45*B*b**3*c**2*d**4 - 18*B*b**3*c*d**5 + + 3*B*b**3*d**6 - c**9 + 9*c**8*d - 36*c**7*d**2 + 84*c**6*d**3 - + 126*c**5*d**4 + 126*c**4*d**5 - 84*c**3*d**6 + 36*c**2*d**7 - + 9*c*d**8 + d**9) + def _t(i): + b = Mul(*info[i][RAD]) + return cancel(rterms[i]/b), Mul(*info[i][BASES]) + aa, AA = _t(0) + bb, BB = _t(1) + cc = -rterms[2] + dd = others + eq = zz.xreplace(dict(zip( + (a, A, b, B, c, d), + (aa, AA, bb, BB, cc, dd)))) + ok = True + # handle power-of-2 cases + if not ok: + if log(lcm, 2).is_Integer and (not others and + len(rterms) == 4 or len(rterms) < 4): + def _norm2(a, b): + return a**2 + b**2 + 2*a*b + + if len(rterms) == 4: + # (r0+r1)**2 - (r2+r3)**2 + r0, r1, r2, r3 = rterms + eq = _norm2(r0, r1) - _norm2(r2, r3) + ok = True + elif len(rterms) == 3: + # (r1+r2)**2 - (r0+others)**2 + r0, r1, r2 = rterms + eq = _norm2(r1, r2) - _norm2(r0, others) + ok = True + elif len(rterms) == 2: + # r0**2 - (r1+others)**2 + r0, r1 = rterms + eq = r0**2 - _norm2(r1, others) + ok = True + + new_depth = sqrt_depth(eq) if ok else depth + rpt += 1 # XXX how many repeats with others unchanging is enough? + if not ok or ( + nwas is not None and len(rterms) == nwas and + new_depth is not None and new_depth == depth and + rpt > 3): + raise NotImplementedError('Cannot remove all radicals') + + flags.update({"cov": cov, "n": len(rterms), "rpt": rpt}) + neq = unrad(eq, *syms, **flags) + if neq: + eq, cov = neq + eq, cov = _canonical(eq, cov) + return eq, cov + + +# delayed imports +from sympy.solvers.bivariate import ( + bivariate_type, _solve_lambert, _filtered_gens) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/solveset.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/solveset.py new file mode 100644 index 0000000000000000000000000000000000000000..0ae242d9c8c4c0d1c1c46cd968a0c5e547ff0f66 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/solveset.py @@ -0,0 +1,4131 @@ +""" +This module contains functions to: + + - solve a single equation for a single variable, in any domain either real or complex. + + - solve a single transcendental equation for a single variable in any domain either real or complex. + (currently supports solving in real domain only) + + - solve a system of linear equations with N variables and M equations. + + - solve a system of Non Linear Equations with N variables and M equations +""" +from sympy.core.sympify import sympify +from sympy.core import (S, Pow, Dummy, pi, Expr, Wild, Mul, + Add, Basic) +from sympy.core.containers import Tuple +from sympy.core.function import (Lambda, expand_complex, AppliedUndef, + expand_log, _mexpand, expand_trig, nfloat) +from sympy.core.mod import Mod +from sympy.core.numbers import I, Number, Rational, oo +from sympy.core.intfunc import integer_log +from sympy.core.relational import Eq, Ne, Relational +from sympy.core.sorting import default_sort_key, ordered +from sympy.core.symbol import Symbol, _uniquely_named_symbol +from sympy.core.sympify import _sympify +from sympy.core.traversal import preorder_traversal +from sympy.external.gmpy import gcd as number_gcd, lcm as number_lcm +from sympy.polys.matrices.linsolve import _linear_eq_to_dict +from sympy.polys.polyroots import UnsolvableFactorError +from sympy.simplify.simplify import simplify, fraction, trigsimp, nsimplify +from sympy.simplify import powdenest, logcombine +from sympy.functions import (log, tan, cot, sin, cos, sec, csc, exp, + acos, asin, atan, acot, acsc, asec, + piecewise_fold, Piecewise) +from sympy.functions.combinatorial.numbers import totient +from sympy.functions.elementary.complexes import Abs, arg, re, im +from sympy.functions.elementary.hyperbolic import (HyperbolicFunction, + sinh, cosh, tanh, coth, sech, csch, + asinh, acosh, atanh, acoth, asech, acsch) +from sympy.functions.elementary.miscellaneous import real_root +from sympy.functions.elementary.trigonometric import TrigonometricFunction +from sympy.logic.boolalg import And, BooleanTrue +from sympy.sets import (FiniteSet, imageset, Interval, Intersection, + Union, ConditionSet, ImageSet, Complement, Contains) +from sympy.sets.sets import Set, ProductSet +from sympy.matrices import zeros, Matrix, MatrixBase +from sympy.ntheory.factor_ import divisors +from sympy.ntheory.residue_ntheory import discrete_log, nthroot_mod +from sympy.polys import (roots, Poly, degree, together, PolynomialError, + RootOf, factor, lcm, gcd) +from sympy.polys.polyerrors import CoercionFailed +from sympy.polys.polytools import invert, groebner, poly +from sympy.polys.solvers import (sympy_eqs_to_ring, solve_lin_sys, + PolyNonlinearError) +from sympy.polys.matrices.linsolve import _linsolve +from sympy.solvers.solvers import (checksol, denoms, unrad, + _simple_dens, recast_to_symbols) +from sympy.solvers.polysys import solve_poly_system +from sympy.utilities import filldedent +from sympy.utilities.iterables import (numbered_symbols, has_dups, + is_sequence, iterable) +from sympy.calculus.util import periodicity, continuous_domain, function_range + + +from types import GeneratorType + + +class NonlinearError(ValueError): + """Raised when unexpectedly encountering nonlinear equations""" + pass + + +def _masked(f, *atoms): + """Return ``f``, with all objects given by ``atoms`` replaced with + Dummy symbols, ``d``, and the list of replacements, ``(d, e)``, + where ``e`` is an object of type given by ``atoms`` in which + any other instances of atoms have been recursively replaced with + Dummy symbols, too. The tuples are ordered so that if they are + applied in sequence, the origin ``f`` will be restored. + + Examples + ======== + + >>> from sympy import cos + >>> from sympy.abc import x + >>> from sympy.solvers.solveset import _masked + + >>> f = cos(cos(x) + 1) + >>> f, reps = _masked(cos(1 + cos(x)), cos) + >>> f + _a1 + >>> reps + [(_a1, cos(_a0 + 1)), (_a0, cos(x))] + >>> for d, e in reps: + ... f = f.xreplace({d: e}) + >>> f + cos(cos(x) + 1) + """ + sym = numbered_symbols('a', cls=Dummy, real=True) + mask = [] + for a in ordered(f.atoms(*atoms)): + for i in mask: + a = a.replace(*i) + mask.append((a, next(sym))) + for i, (o, n) in enumerate(mask): + f = f.replace(o, n) + mask[i] = (n, o) + mask = list(reversed(mask)) + return f, mask + + +def _invert(f_x, y, x, domain=S.Complexes): + r""" + Reduce the complex valued equation $f(x) = y$ to a set of equations + + $$\left\{g(x) = h_1(y),\ g(x) = h_2(y),\ \dots,\ g(x) = h_n(y) \right\}$$ + + where $g(x)$ is a simpler function than $f(x)$. The return value is a tuple + $(g(x), \mathrm{set}_h)$, where $g(x)$ is a function of $x$ and $\mathrm{set}_h$ is + the set of function $\left\{h_1(y), h_2(y), \dots, h_n(y)\right\}$. + Here, $y$ is not necessarily a symbol. + + $\mathrm{set}_h$ contains the functions, along with the information + about the domain in which they are valid, through set + operations. For instance, if :math:`y = |x| - n` is inverted + in the real domain, then $\mathrm{set}_h$ is not simply + $\{-n, n\}$ as the nature of `n` is unknown; rather, it is: + + $$ \left(\left[0, \infty\right) \cap \left\{n\right\}\right) \cup + \left(\left(-\infty, 0\right] \cap \left\{- n\right\}\right)$$ + + By default, the complex domain is used which means that inverting even + seemingly simple functions like $\exp(x)$ will give very different + results from those obtained in the real domain. + (In the case of $\exp(x)$, the inversion via $\log$ is multi-valued + in the complex domain, having infinitely many branches.) + + If you are working with real values only (or you are not sure which + function to use) you should probably set the domain to + ``S.Reals`` (or use ``invert_real`` which does that automatically). + + + Examples + ======== + + >>> from sympy.solvers.solveset import invert_complex, invert_real + >>> from sympy.abc import x, y + >>> from sympy import exp + + When does exp(x) == y? + + >>> invert_complex(exp(x), y, x) + (x, ImageSet(Lambda(_n, I*(2*_n*pi + arg(y)) + log(Abs(y))), Integers)) + >>> invert_real(exp(x), y, x) + (x, Intersection({log(y)}, Reals)) + + When does exp(x) == 1? + + >>> invert_complex(exp(x), 1, x) + (x, ImageSet(Lambda(_n, 2*_n*I*pi), Integers)) + >>> invert_real(exp(x), 1, x) + (x, {0}) + + See Also + ======== + invert_real, invert_complex + """ + x = sympify(x) + if not x.is_Symbol: + raise ValueError("x must be a symbol") + f_x = sympify(f_x) + if x not in f_x.free_symbols: + raise ValueError("Inverse of constant function doesn't exist") + y = sympify(y) + if x in y.free_symbols: + raise ValueError("y should be independent of x ") + + if domain.is_subset(S.Reals): + x1, s = _invert_real(f_x, FiniteSet(y), x) + else: + x1, s = _invert_complex(f_x, FiniteSet(y), x) + + # f couldn't be inverted completely; return unmodified. + if x1 != x: + return x1, s + + # Avoid adding gratuitous intersections with S.Complexes. Actual + # conditions should be handled by the respective inverters. + if domain is S.Complexes: + return x1, s + + if isinstance(s, FiniteSet): + return x1, s.intersect(domain) + + # "Fancier" solution sets like those obtained by inversion of trigonometric + # functions already include general validity conditions (i.e. conditions on + # the domain of the respective inverse functions), so we should avoid adding + # blanket intersections with S.Reals. But subsets of R (or C) must still be + # accounted for. + if domain is S.Reals: + return x1, s + else: + return x1, s.intersect(domain) + + +invert_complex = _invert + + +def invert_real(f_x, y, x): + """ + Inverts a real-valued function. Same as :func:`invert_complex`, but sets + the domain to ``S.Reals`` before inverting. + """ + return _invert(f_x, y, x, S.Reals) + + +def _invert_real(f, g_ys, symbol): + """Helper function for _invert.""" + + if f == symbol or g_ys is S.EmptySet: + return (symbol, g_ys) + + n = Dummy('n', real=True) + + if isinstance(f, exp) or (f.is_Pow and f.base == S.Exp1): + return _invert_real(f.exp, + imageset(Lambda(n, log(n)), g_ys), + symbol) + + if hasattr(f, 'inverse') and f.inverse() is not None and not isinstance(f, ( + TrigonometricFunction, + HyperbolicFunction, + )): + if len(f.args) > 1: + raise ValueError("Only functions with one argument are supported.") + return _invert_real(f.args[0], + imageset(Lambda(n, f.inverse()(n)), g_ys), + symbol) + + if isinstance(f, Abs): + return _invert_abs(f.args[0], g_ys, symbol) + + if f.is_Add: + # f = g + h + g, h = f.as_independent(symbol) + if g is not S.Zero: + return _invert_real(h, imageset(Lambda(n, n - g), g_ys), symbol) + + if f.is_Mul: + # f = g*h + g, h = f.as_independent(symbol) + + if g is not S.One: + return _invert_real(h, imageset(Lambda(n, n/g), g_ys), symbol) + + if f.is_Pow: + base, expo = f.args + base_has_sym = base.has(symbol) + expo_has_sym = expo.has(symbol) + + if not expo_has_sym: + + if expo.is_rational: + num, den = expo.as_numer_denom() + + if den % 2 == 0 and num % 2 == 1 and den.is_zero is False: + # Here we have f(x)**(num/den) = y + # where den is nonzero and even and y is an element + # of the set g_ys. + # den is even, so we are only interested in the cases + # where both f(x) and y are positive. + # Restricting y to be positive (using the set g_ys_pos) + # means that y**(den/num) is always positive. + # Therefore it isn't necessary to also constrain f(x) + # to be positive because we are only going to + # find solutions of f(x) = y**(d/n) + # where the rhs is already required to be positive. + root = Lambda(n, real_root(n, expo)) + g_ys_pos = g_ys & Interval(0, oo) + res = imageset(root, g_ys_pos) + _inv, _set = _invert_real(base, res, symbol) + return (_inv, _set) + + if den % 2 == 1: + root = Lambda(n, real_root(n, expo)) + res = imageset(root, g_ys) + if num % 2 == 0: + neg_res = imageset(Lambda(n, -n), res) + return _invert_real(base, res + neg_res, symbol) + if num % 2 == 1: + return _invert_real(base, res, symbol) + + elif expo.is_irrational: + root = Lambda(n, real_root(n, expo)) + g_ys_pos = g_ys & Interval(0, oo) + res = imageset(root, g_ys_pos) + return _invert_real(base, res, symbol) + + else: + # indeterminate exponent, e.g. Float or parity of + # num, den of rational could not be determined + pass # use default return + + if not base_has_sym: + rhs = g_ys.args[0] + if base.is_positive: + return _invert_real(expo, + imageset(Lambda(n, log(n, base, evaluate=False)), g_ys), symbol) + elif base.is_negative: + s, b = integer_log(rhs, base) + if b: + return _invert_real(expo, FiniteSet(s), symbol) + else: + return (expo, S.EmptySet) + elif base.is_zero: + one = Eq(rhs, 1) + if one == S.true: + # special case: 0**x - 1 + return _invert_real(expo, FiniteSet(0), symbol) + elif one == S.false: + return (expo, S.EmptySet) + + if isinstance(f, (TrigonometricFunction, HyperbolicFunction)): + return _invert_trig_hyp_real(f, g_ys, symbol) + + return (f, g_ys) + + +# Dictionaries of inverses will be cached after first use. +_trig_inverses = None +_hyp_inverses = None + +def _invert_trig_hyp_real(f, g_ys, symbol): + """Helper function for inverting trigonometric and hyperbolic functions. + + This helper only handles inversion over the reals. + + For trigonometric functions only finite `g_ys` sets are implemented. + + For hyperbolic functions the set `g_ys` is checked against the domain of the + respective inverse functions. Infinite `g_ys` sets are also supported. + """ + + if isinstance(f, HyperbolicFunction): + n = Dummy('n', real=True) + + if isinstance(f, sinh): + # asinh is defined over R. + return _invert_real(f.args[0], imageset(n, asinh(n), g_ys), symbol) + + if isinstance(f, cosh): + g_ys_dom = g_ys.intersect(Interval(1, oo)) + if isinstance(g_ys_dom, Intersection): + # could not properly resolve domain check + if isinstance(g_ys, FiniteSet): + # If g_ys is a `FiniteSet`` it should be sufficient to just + # let the calling `_invert_real()` add an intersection with + # `S.Reals` (or a subset `domain`) to ensure that only valid + # (real) solutions are returned. + # This avoids adding "too many" Intersections or + # ConditionSets in the returned set. + g_ys_dom = g_ys + else: + return (f, g_ys) + return _invert_real(f.args[0], Union( + imageset(n, acosh(n), g_ys_dom), + imageset(n, -acosh(n), g_ys_dom)), symbol) + + if isinstance(f, sech): + g_ys_dom = g_ys.intersect(Interval.Lopen(0, 1)) + if isinstance(g_ys_dom, Intersection): + if isinstance(g_ys, FiniteSet): + g_ys_dom = g_ys + else: + return (f, g_ys) + return _invert_real(f.args[0], Union( + imageset(n, asech(n), g_ys_dom), + imageset(n, -asech(n), g_ys_dom)), symbol) + + if isinstance(f, tanh): + g_ys_dom = g_ys.intersect(Interval.open(-1, 1)) + if isinstance(g_ys_dom, Intersection): + if isinstance(g_ys, FiniteSet): + g_ys_dom = g_ys + else: + return (f, g_ys) + return _invert_real(f.args[0], + imageset(n, atanh(n), g_ys_dom), symbol) + + if isinstance(f, coth): + g_ys_dom = g_ys - Interval(-1, 1) + if isinstance(g_ys_dom, Complement): + if isinstance(g_ys, FiniteSet): + g_ys_dom = g_ys + else: + return (f, g_ys) + return _invert_real(f.args[0], + imageset(n, acoth(n), g_ys_dom), symbol) + + if isinstance(f, csch): + g_ys_dom = g_ys - FiniteSet(0) + if isinstance(g_ys_dom, Complement): + if isinstance(g_ys, FiniteSet): + g_ys_dom = g_ys + else: + return (f, g_ys) + return _invert_real(f.args[0], + imageset(n, acsch(n), g_ys_dom), symbol) + + elif isinstance(f, TrigonometricFunction) and isinstance(g_ys, FiniteSet): + def _get_trig_inverses(func): + global _trig_inverses + if _trig_inverses is None: + _trig_inverses = { + sin : ((asin, lambda y: pi-asin(y)), 2*pi, Interval(-1, 1)), + cos : ((acos, lambda y: -acos(y)), 2*pi, Interval(-1, 1)), + tan : ((atan,), pi, S.Reals), + cot : ((acot,), pi, S.Reals), + sec : ((asec, lambda y: -asec(y)), 2*pi, + Union(Interval(-oo, -1), Interval(1, oo))), + csc : ((acsc, lambda y: pi-acsc(y)), 2*pi, + Union(Interval(-oo, -1), Interval(1, oo)))} + return _trig_inverses[func] + + invs, period, rng = _get_trig_inverses(f.func) + n = Dummy('n', integer=True) + def create_return_set(g): + # returns ConditionSet that will be part of the final (x, set) tuple + invsimg = Union(*[ + imageset(n, period*n + inv(g), S.Integers) for inv in invs]) + inv_f, inv_g_ys = _invert_real(f.args[0], invsimg, symbol) + if inv_f == symbol: # inversion successful + conds = rng.contains(g) + return ConditionSet(symbol, conds, inv_g_ys) + else: + return ConditionSet(symbol, Eq(f, g), S.Reals) + + retset = Union(*[create_return_set(g) for g in g_ys]) + return (symbol, retset) + + else: + return (f, g_ys) + + +def _invert_trig_hyp_complex(f, g_ys, symbol): + """Helper function for inverting trigonometric and hyperbolic functions. + + This helper only handles inversion over the complex numbers. + Only finite `g_ys` sets are implemented. + + Handling of singularities is only implemented for hyperbolic equations. + In case of a symbolic element g in g_ys a ConditionSet may be returned. + """ + + if isinstance(f, TrigonometricFunction) and isinstance(g_ys, FiniteSet): + def inv(trig): + if isinstance(trig, (sin, csc)): + F = asin if isinstance(trig, sin) else acsc + return ( + lambda a: 2*n*pi + F(a), + lambda a: 2*n*pi + pi - F(a)) + if isinstance(trig, (cos, sec)): + F = acos if isinstance(trig, cos) else asec + return ( + lambda a: 2*n*pi + F(a), + lambda a: 2*n*pi - F(a)) + if isinstance(trig, (tan, cot)): + return (lambda a: n*pi + trig.inverse()(a),) + + n = Dummy('n', integer=True) + invs = S.EmptySet + for L in inv(f): + invs += Union(*[imageset(Lambda(n, L(g)), S.Integers) for g in g_ys]) + return _invert_complex(f.args[0], invs, symbol) + + elif isinstance(f, HyperbolicFunction) and isinstance(g_ys, FiniteSet): + # There are two main options regarding singularities / domain checking + # for symbolic elements in g_ys: + # 1. Add a "catch-all" intersection with S.Complexes. + # 2. ConditionSets. + # At present ConditionSets seem to work better and have the additional + # benefit of representing the precise conditions that must be satisfied. + # The conditions are also rather straightforward. (At most two isolated + # points.) + def _get_hyp_inverses(func): + global _hyp_inverses + if _hyp_inverses is None: + _hyp_inverses = { + sinh : ((asinh, lambda y: I*pi-asinh(y)), 2*I*pi, ()), + cosh : ((acosh, lambda y: -acosh(y)), 2*I*pi, ()), + tanh : ((atanh,), I*pi, (-1, 1)), + coth : ((acoth,), I*pi, (-1, 1)), + sech : ((asech, lambda y: -asech(y)), 2*I*pi, (0, )), + csch : ((acsch, lambda y: I*pi-acsch(y)), 2*I*pi, (0, ))} + return _hyp_inverses[func] + + # invs: iterable of main inverses, e.g. (acosh, -acosh). + # excl: iterable of singularities to be checked for. + invs, period, excl = _get_hyp_inverses(f.func) + n = Dummy('n', integer=True) + def create_return_set(g): + # returns ConditionSet that will be part of the final (x, set) tuple + invsimg = Union(*[ + imageset(n, period*n + inv(g), S.Integers) for inv in invs]) + inv_f, inv_g_ys = _invert_complex(f.args[0], invsimg, symbol) + if inv_f == symbol: # inversion successful + conds = And(*[Ne(g, e) for e in excl]) + return ConditionSet(symbol, conds, inv_g_ys) + else: + return ConditionSet(symbol, Eq(f, g), S.Complexes) + + retset = Union(*[create_return_set(g) for g in g_ys]) + return (symbol, retset) + + else: + return (f, g_ys) + + +def _invert_complex(f, g_ys, symbol): + """Helper function for _invert.""" + + if f == symbol or g_ys is S.EmptySet: + return (symbol, g_ys) + + n = Dummy('n') + + if f.is_Add: + # f = g + h + g, h = f.as_independent(symbol) + if g is not S.Zero: + return _invert_complex(h, imageset(Lambda(n, n - g), g_ys), symbol) + + if f.is_Mul: + # f = g*h + g, h = f.as_independent(symbol) + + if g is not S.One: + if g in {S.NegativeInfinity, S.ComplexInfinity, S.Infinity}: + return (h, S.EmptySet) + return _invert_complex(h, imageset(Lambda(n, n/g), g_ys), symbol) + + if f.is_Pow: + base, expo = f.args + # special case: g**r = 0 + # Could be improved like `_invert_real` to handle more general cases. + if expo.is_Rational and g_ys == FiniteSet(0): + if expo.is_positive: + return _invert_complex(base, g_ys, symbol) + + if hasattr(f, 'inverse') and f.inverse() is not None and \ + not isinstance(f, TrigonometricFunction) and \ + not isinstance(f, HyperbolicFunction) and \ + not isinstance(f, exp): + if len(f.args) > 1: + raise ValueError("Only functions with one argument are supported.") + return _invert_complex(f.args[0], + imageset(Lambda(n, f.inverse()(n)), g_ys), symbol) + + if isinstance(f, exp) or (f.is_Pow and f.base == S.Exp1): + if isinstance(g_ys, ImageSet): + # can solve up to `(d*exp(exp(...(exp(a*x + b))...) + c)` format. + # Further can be improved to `(d*exp(exp(...(exp(a*x**n + b*x**(n-1) + ... + f))...) + c)`. + g_ys_expr = g_ys.lamda.expr + g_ys_vars = g_ys.lamda.variables + k = Dummy('k{}'.format(len(g_ys_vars))) + g_ys_vars_1 = (k,) + g_ys_vars + exp_invs = Union(*[imageset(Lambda((g_ys_vars_1,), (I*(2*k*pi + arg(g_ys_expr)) + + log(Abs(g_ys_expr)))), S.Integers**(len(g_ys_vars_1)))]) + return _invert_complex(f.exp, exp_invs, symbol) + + elif isinstance(g_ys, FiniteSet): + exp_invs = Union(*[imageset(Lambda(n, I*(2*n*pi + arg(g_y)) + + log(Abs(g_y))), S.Integers) + for g_y in g_ys if g_y != 0]) + return _invert_complex(f.exp, exp_invs, symbol) + + if isinstance(f, (TrigonometricFunction, HyperbolicFunction)): + return _invert_trig_hyp_complex(f, g_ys, symbol) + + return (f, g_ys) + + +def _invert_abs(f, g_ys, symbol): + """Helper function for inverting absolute value functions. + + Returns the complete result of inverting an absolute value + function along with the conditions which must also be satisfied. + + If it is certain that all these conditions are met, a :class:`~.FiniteSet` + of all possible solutions is returned. If any condition cannot be + satisfied, an :class:`~.EmptySet` is returned. Otherwise, a + :class:`~.ConditionSet` of the solutions, with all the required conditions + specified, is returned. + + """ + if not g_ys.is_FiniteSet: + # this could be used for FiniteSet, but the + # results are more compact if they aren't, e.g. + # ConditionSet(x, Contains(n, Interval(0, oo)), {-n, n}) vs + # Union(Intersection(Interval(0, oo), {n}), Intersection(Interval(-oo, 0), {-n})) + # for the solution of abs(x) - n + pos = Intersection(g_ys, Interval(0, S.Infinity)) + parg = _invert_real(f, pos, symbol) + narg = _invert_real(-f, pos, symbol) + if parg[0] != narg[0]: + raise NotImplementedError + return parg[0], Union(narg[1], parg[1]) + + # check conditions: all these must be true. If any are unknown + # then return them as conditions which must be satisfied + unknown = [] + for a in g_ys.args: + ok = a.is_nonnegative if a.is_Number else a.is_positive + if ok is None: + unknown.append(a) + elif not ok: + return symbol, S.EmptySet + if unknown: + conditions = And(*[Contains(i, Interval(0, oo)) + for i in unknown]) + else: + conditions = True + n = Dummy('n', real=True) + # this is slightly different than above: instead of solving + # +/-f on positive values, here we solve for f on +/- g_ys + g_x, values = _invert_real(f, Union( + imageset(Lambda(n, n), g_ys), + imageset(Lambda(n, -n), g_ys)), symbol) + return g_x, ConditionSet(g_x, conditions, values) + + +def domain_check(f, symbol, p): + """Returns False if point p is infinite or any subexpression of f + is infinite or becomes so after replacing symbol with p. If none of + these conditions is met then True will be returned. + + Examples + ======== + + >>> from sympy import Mul, oo + >>> from sympy.abc import x + >>> from sympy.solvers.solveset import domain_check + >>> g = 1/(1 + (1/(x + 1))**2) + >>> domain_check(g, x, -1) + False + >>> domain_check(x**2, x, 0) + True + >>> domain_check(1/x, x, oo) + False + + * The function relies on the assumption that the original form + of the equation has not been changed by automatic simplification. + + >>> domain_check(x/x, x, 0) # x/x is automatically simplified to 1 + True + + * To deal with automatic evaluations use evaluate=False: + + >>> domain_check(Mul(x, 1/x, evaluate=False), x, 0) + False + """ + f, p = sympify(f), sympify(p) + if p.is_infinite: + return False + return _domain_check(f, symbol, p) + + +def _domain_check(f, symbol, p): + # helper for domain check + if f.is_Atom and f.is_finite: + return True + elif f.subs(symbol, p).is_infinite: + return False + elif isinstance(f, Piecewise): + # Check the cases of the Piecewise in turn. There might be invalid + # expressions in later cases that don't apply e.g. + # solveset(Piecewise((0, Eq(x, 0)), (1/x, True)), x) + for expr, cond in f.args: + condsubs = cond.subs(symbol, p) + if condsubs is S.false: + continue + elif condsubs is S.true: + return _domain_check(expr, symbol, p) + else: + # We don't know which case of the Piecewise holds. On this + # basis we cannot decide whether any solution is in or out of + # the domain. Ideally this function would allow returning a + # symbolic condition for the validity of the solution that + # could be handled in the calling code. In the mean time we'll + # give this particular solution the benefit of the doubt and + # let it pass. + return True + else: + # TODO : We should not blindly recurse through all args of arbitrary expressions like this + return all(_domain_check(g, symbol, p) + for g in f.args) + + +def _is_finite_with_finite_vars(f, domain=S.Complexes): + """ + Return True if the given expression is finite. For symbols that + do not assign a value for `complex` and/or `real`, the domain will + be used to assign a value; symbols that do not assign a value + for `finite` will be made finite. All other assumptions are + left unmodified. + """ + def assumptions(s): + A = s.assumptions0 + A.setdefault('finite', A.get('finite', True)) + if domain.is_subset(S.Reals): + # if this gets set it will make complex=True, too + A.setdefault('real', True) + else: + # don't change 'real' because being complex implies + # nothing about being real + A.setdefault('complex', True) + return A + + reps = {s: Dummy(**assumptions(s)) for s in f.free_symbols} + return f.xreplace(reps).is_finite + + +def _is_function_class_equation(func_class, f, symbol): + """ Tests whether the equation is an equation of the given function class. + + The given equation belongs to the given function class if it is + comprised of functions of the function class which are multiplied by + or added to expressions independent of the symbol. In addition, the + arguments of all such functions must be linear in the symbol as well. + + Examples + ======== + + >>> from sympy.solvers.solveset import _is_function_class_equation + >>> from sympy import tan, sin, tanh, sinh, exp + >>> from sympy.abc import x + >>> from sympy.functions.elementary.trigonometric import TrigonometricFunction + >>> from sympy.functions.elementary.hyperbolic import HyperbolicFunction + >>> _is_function_class_equation(TrigonometricFunction, exp(x) + tan(x), x) + False + >>> _is_function_class_equation(TrigonometricFunction, tan(x) + sin(x), x) + True + >>> _is_function_class_equation(TrigonometricFunction, tan(x**2), x) + False + >>> _is_function_class_equation(TrigonometricFunction, tan(x + 2), x) + True + >>> _is_function_class_equation(HyperbolicFunction, tanh(x) + sinh(x), x) + True + """ + if f.is_Mul or f.is_Add: + return all(_is_function_class_equation(func_class, arg, symbol) + for arg in f.args) + + if f.is_Pow: + if not f.exp.has(symbol): + return _is_function_class_equation(func_class, f.base, symbol) + else: + return False + + if not f.has(symbol): + return True + + if isinstance(f, func_class): + try: + g = Poly(f.args[0], symbol) + return g.degree() <= 1 + except PolynomialError: + return False + else: + return False + + +def _solve_as_rational(f, symbol, domain): + """ solve rational functions""" + f = together(_mexpand(f, recursive=True), deep=True) + g, h = fraction(f) + if not h.has(symbol): + try: + return _solve_as_poly(g, symbol, domain) + except NotImplementedError: + # The polynomial formed from g could end up having + # coefficients in a ring over which finding roots + # isn't implemented yet, e.g. ZZ[a] for some symbol a + return ConditionSet(symbol, Eq(f, 0), domain) + except CoercionFailed: + # contained oo, zoo or nan + return S.EmptySet + else: + valid_solns = _solveset(g, symbol, domain) + invalid_solns = _solveset(h, symbol, domain) + return valid_solns - invalid_solns + + +class _SolveTrig1Error(Exception): + """Raised when _solve_trig1 heuristics do not apply""" + +def _solve_trig(f, symbol, domain): + """Function to call other helpers to solve trigonometric equations """ + # If f is composed of a single trig function (potentially appearing multiple + # times) we should solve by either inverting directly or inverting after a + # suitable change of variable. + # + # _solve_trig is currently only called by _solveset for trig/hyperbolic + # functions of an argument linear in x. Inverting a symbolic argument should + # include a guard against division by zero in order to have a result that is + # consistent with similar processing done by _solve_trig1. + # (Ideally _invert should add these conditions by itself.) + trig_expr, count = None, 0 + for expr in preorder_traversal(f): + if isinstance(expr, (TrigonometricFunction, + HyperbolicFunction)) and expr.has(symbol): + if not trig_expr: + trig_expr, count = expr, 1 + elif expr == trig_expr: + count += 1 + else: + trig_expr, count = False, 0 + break + if count == 1: + # direct inversion + x, sol = _invert(f, 0, symbol, domain) + if x == symbol: + cond = True + if trig_expr.free_symbols - {symbol}: + a, h = trig_expr.args[0].as_independent(symbol, as_Add=True) + m, h = h.as_independent(symbol, as_Add=False) + num, den = m.as_numer_denom() + cond = Ne(num, 0) & Ne(den, 0) + return ConditionSet(symbol, cond, sol) + else: + return ConditionSet(symbol, Eq(f, 0), domain) + elif count: + # solve by change of variable + y = Dummy('y') + f_cov = f.subs(trig_expr, y) + sol_cov = solveset(f_cov, y, domain) + if isinstance(sol_cov, FiniteSet): + return Union( + *[_solve_trig(trig_expr-s, symbol, domain) for s in sol_cov]) + + sol = None + try: + # multiple trig/hyp functions; solve by rewriting to exp + sol = _solve_trig1(f, symbol, domain) + except _SolveTrig1Error: + try: + # multiple trig/hyp functions; solve by rewriting to tan(x/2) + sol = _solve_trig2(f, symbol, domain) + except ValueError: + raise NotImplementedError(filldedent(''' + Solution to this kind of trigonometric equations + is yet to be implemented''')) + return sol + + +def _solve_trig1(f, symbol, domain): + """Primary solver for trigonometric and hyperbolic equations + + Returns either the solution set as a ConditionSet (auto-evaluated to a + union of ImageSets if no variables besides 'symbol' are involved) or + raises _SolveTrig1Error if f == 0 cannot be solved. + + Notes + ===== + Algorithm: + 1. Do a change of variable x -> mu*x in arguments to trigonometric and + hyperbolic functions, in order to reduce them to small integers. (This + step is crucial to keep the degrees of the polynomials of step 4 low.) + 2. Rewrite trigonometric/hyperbolic functions as exponentials. + 3. Proceed to a 2nd change of variable, replacing exp(I*x) or exp(x) by y. + 4. Solve the resulting rational equation. + 5. Use invert_complex or invert_real to return to the original variable. + 6. If the coefficients of 'symbol' were symbolic in nature, add the + necessary consistency conditions in a ConditionSet. + + """ + # Prepare change of variable + x = Dummy('x') + if _is_function_class_equation(HyperbolicFunction, f, symbol): + cov = exp(x) + inverter = invert_real if domain.is_subset(S.Reals) else invert_complex + else: + cov = exp(I*x) + inverter = invert_complex + + f = trigsimp(f) + f_original = f + trig_functions = f.atoms(TrigonometricFunction, HyperbolicFunction) + trig_arguments = [e.args[0] for e in trig_functions] + # trigsimp may have reduced the equation to an expression + # that is independent of 'symbol' (e.g. cos**2+sin**2) + if not any(a.has(symbol) for a in trig_arguments): + return solveset(f_original, symbol, domain) + + denominators = [] + numerators = [] + for ar in trig_arguments: + try: + poly_ar = Poly(ar, symbol) + except PolynomialError: + raise _SolveTrig1Error("trig argument is not a polynomial") + if poly_ar.degree() > 1: # degree >1 still bad + raise _SolveTrig1Error("degree of variable must not exceed one") + if poly_ar.degree() == 0: # degree 0, don't care + continue + c = poly_ar.all_coeffs()[0] # got the coefficient of 'symbol' + numerators.append(fraction(c)[0]) + denominators.append(fraction(c)[1]) + + mu = lcm(denominators)/gcd(numerators) + f = f.subs(symbol, mu*x) + f = f.rewrite(exp) + f = together(f) + g, h = fraction(f) + y = Dummy('y') + g, h = g.expand(), h.expand() + g, h = g.subs(cov, y), h.subs(cov, y) + if g.has(x) or h.has(x): + raise _SolveTrig1Error("change of variable not possible") + + solns = solveset_complex(g, y) - solveset_complex(h, y) + if isinstance(solns, ConditionSet): + raise _SolveTrig1Error("polynomial has ConditionSet solution") + + if isinstance(solns, FiniteSet): + if any(isinstance(s, RootOf) for s in solns): + raise _SolveTrig1Error("polynomial results in RootOf object") + # revert the change of variable + cov = cov.subs(x, symbol/mu) + result = Union(*[inverter(cov, s, symbol)[1] for s in solns]) + # In case of symbolic coefficients, the solution set is only valid + # if numerator and denominator of mu are non-zero. + if mu.has(Symbol): + syms = (mu).atoms(Symbol) + munum, muden = fraction(mu) + condnum = munum.as_independent(*syms, as_Add=False)[1] + condden = muden.as_independent(*syms, as_Add=False)[1] + cond = And(Ne(condnum, 0), Ne(condden, 0)) + else: + cond = True + # Actual conditions are returned as part of the ConditionSet. Adding an + # intersection with C would only complicate some solution sets due to + # current limitations of intersection code. (e.g. #19154) + if domain is S.Complexes: + # This is a slight abuse of ConditionSet. Ideally this should + # be some kind of "PiecewiseSet". (See #19507 discussion) + return ConditionSet(symbol, cond, result) + else: + return ConditionSet(symbol, cond, Intersection(result, domain)) + elif solns is S.EmptySet: + return S.EmptySet + else: + raise _SolveTrig1Error("polynomial solutions must form FiniteSet") + + +def _solve_trig2(f, symbol, domain): + """Secondary helper to solve trigonometric equations, + called when first helper fails """ + f = trigsimp(f) + f_original = f + trig_functions = f.atoms(sin, cos, tan, sec, cot, csc) + trig_arguments = [e.args[0] for e in trig_functions] + denominators = [] + numerators = [] + + # todo: This solver can be extended to hyperbolics if the + # analogous change of variable to tanh (instead of tan) + # is used. + if not trig_functions: + return ConditionSet(symbol, Eq(f_original, 0), domain) + + # todo: The pre-processing below (extraction of numerators, denominators, + # gcd, lcm, mu, etc.) should be updated to the enhanced version in + # _solve_trig1. (See #19507) + for ar in trig_arguments: + try: + poly_ar = Poly(ar, symbol) + except PolynomialError: + raise ValueError("give up, we cannot solve if this is not a polynomial in x") + if poly_ar.degree() > 1: # degree >1 still bad + raise ValueError("degree of variable inside polynomial should not exceed one") + if poly_ar.degree() == 0: # degree 0, don't care + continue + c = poly_ar.all_coeffs()[0] # got the coefficient of 'symbol' + try: + numerators.append(Rational(c).p) + denominators.append(Rational(c).q) + except TypeError: + return ConditionSet(symbol, Eq(f_original, 0), domain) + + x = Dummy('x') + + mu = Rational(2)*number_lcm(*denominators)/number_gcd(*numerators) + f = f.subs(symbol, mu*x) + f = f.rewrite(tan) + f = expand_trig(f) + f = together(f) + + g, h = fraction(f) + y = Dummy('y') + g, h = g.expand(), h.expand() + g, h = g.subs(tan(x), y), h.subs(tan(x), y) + + if g.has(x) or h.has(x): + return ConditionSet(symbol, Eq(f_original, 0), domain) + solns = solveset(g, y, S.Reals) - solveset(h, y, S.Reals) + + if isinstance(solns, FiniteSet): + result = Union(*[invert_real(tan(symbol/mu), s, symbol)[1] + for s in solns]) + dsol = invert_real(tan(symbol/mu), oo, symbol)[1] + if degree(h) > degree(g): # If degree(denom)>degree(num) then there + result = Union(result, dsol) # would be another sol at Lim(denom-->oo) + return Intersection(result, domain) + elif solns is S.EmptySet: + return S.EmptySet + else: + return ConditionSet(symbol, Eq(f_original, 0), S.Reals) + + +def _solve_as_poly(f, symbol, domain=S.Complexes): + """ + Solve the equation using polynomial techniques if it already is a + polynomial equation or, with a change of variables, can be made so. + """ + result = None + if f.is_polynomial(symbol): + solns = roots(f, symbol, cubics=True, quartics=True, + quintics=True, domain='EX') + num_roots = sum(solns.values()) + if degree(f, symbol) <= num_roots: + result = FiniteSet(*solns.keys()) + else: + poly = Poly(f, symbol) + solns = poly.all_roots() + if poly.degree() <= len(solns): + result = FiniteSet(*solns) + else: + result = ConditionSet(symbol, Eq(f, 0), domain) + else: + poly = Poly(f) + if poly is None: + result = ConditionSet(symbol, Eq(f, 0), domain) + gens = [g for g in poly.gens if g.has(symbol)] + + if len(gens) == 1: + poly = Poly(poly, gens[0]) + gen = poly.gen + deg = poly.degree() + poly = Poly(poly.as_expr(), poly.gen, composite=True) + poly_solns = FiniteSet(*roots(poly, cubics=True, quartics=True, + quintics=True).keys()) + + if len(poly_solns) < deg: + result = ConditionSet(symbol, Eq(f, 0), domain) + + if gen != symbol: + y = Dummy('y') + inverter = invert_real if domain.is_subset(S.Reals) else invert_complex + lhs, rhs_s = inverter(gen, y, symbol) + if lhs == symbol: + result = Union(*[rhs_s.subs(y, s) for s in poly_solns]) + if isinstance(result, FiniteSet) and isinstance(gen, Pow + ) and gen.base.is_Rational: + result = FiniteSet(*[expand_log(i) for i in result]) + else: + result = ConditionSet(symbol, Eq(f, 0), domain) + else: + result = ConditionSet(symbol, Eq(f, 0), domain) + + if result is not None: + if isinstance(result, FiniteSet): + # this is to simplify solutions like -sqrt(-I) to sqrt(2)/2 + # - sqrt(2)*I/2. We are not expanding for solution with symbols + # or undefined functions because that makes the solution more complicated. + # For example, expand_complex(a) returns re(a) + I*im(a) + if all(s.atoms(Symbol, AppliedUndef) == set() and not isinstance(s, RootOf) + for s in result): + s = Dummy('s') + result = imageset(Lambda(s, expand_complex(s)), result) + if isinstance(result, FiniteSet) and domain != S.Complexes: + # Avoid adding gratuitous intersections with S.Complexes. Actual + # conditions should be handled elsewhere. + result = result.intersection(domain) + return result + else: + return ConditionSet(symbol, Eq(f, 0), domain) + + +def _solve_radical(f, unradf, symbol, solveset_solver): + """ Helper function to solve equations with radicals """ + res = unradf + eq, cov = res if res else (f, []) + if not cov: + result = solveset_solver(eq, symbol) - \ + Union(*[solveset_solver(g, symbol) for g in denoms(f, symbol)]) + else: + y, yeq = cov + if not solveset_solver(y - I, y): + yreal = Dummy('yreal', real=True) + yeq = yeq.xreplace({y: yreal}) + eq = eq.xreplace({y: yreal}) + y = yreal + g_y_s = solveset_solver(yeq, symbol) + f_y_sols = solveset_solver(eq, y) + result = Union(*[imageset(Lambda(y, g_y), f_y_sols) + for g_y in g_y_s]) + + def check_finiteset(solutions): + f_set = [] # solutions for FiniteSet + c_set = [] # solutions for ConditionSet + for s in solutions: + if checksol(f, symbol, s): + f_set.append(s) + else: + c_set.append(s) + return FiniteSet(*f_set) + ConditionSet(symbol, Eq(f, 0), FiniteSet(*c_set)) + + def check_set(solutions): + if solutions is S.EmptySet: + return solutions + elif isinstance(solutions, ConditionSet): + # XXX: Maybe the base set should be checked? + return solutions + elif isinstance(solutions, FiniteSet): + return check_finiteset(solutions) + elif isinstance(solutions, Complement): + A, B = solutions.args + return Complement(check_set(A), B) + elif isinstance(solutions, Union): + return Union(*[check_set(s) for s in solutions.args]) + else: + # XXX: There should be more cases checked here. The cases above + # are all those that come up in the test suite for now. + return solutions + + solution_set = check_set(result) + + return solution_set + + +def _solve_abs(f, symbol, domain): + """ Helper function to solve equation involving absolute value function """ + if not domain.is_subset(S.Reals): + raise ValueError(filldedent(''' + Absolute values cannot be inverted in the + complex domain.''')) + p, q, r = Wild('p'), Wild('q'), Wild('r') + pattern_match = f.match(p*Abs(q) + r) or {} + f_p, f_q, f_r = [pattern_match.get(i, S.Zero) for i in (p, q, r)] + + if not (f_p.is_zero or f_q.is_zero): + domain = continuous_domain(f_q, symbol, domain) + from .inequalities import solve_univariate_inequality + q_pos_cond = solve_univariate_inequality(f_q >= 0, symbol, + relational=False, domain=domain, continuous=True) + q_neg_cond = q_pos_cond.complement(domain) + + sols_q_pos = solveset_real(f_p*f_q + f_r, + symbol).intersect(q_pos_cond) + sols_q_neg = solveset_real(f_p*(-f_q) + f_r, + symbol).intersect(q_neg_cond) + return Union(sols_q_pos, sols_q_neg) + else: + return ConditionSet(symbol, Eq(f, 0), domain) + + +def solve_decomposition(f, symbol, domain): + """ + Function to solve equations via the principle of "Decomposition + and Rewriting". + + Examples + ======== + >>> from sympy import exp, sin, Symbol, pprint, S + >>> from sympy.solvers.solveset import solve_decomposition as sd + >>> x = Symbol('x') + >>> f1 = exp(2*x) - 3*exp(x) + 2 + >>> sd(f1, x, S.Reals) + {0, log(2)} + >>> f2 = sin(x)**2 + 2*sin(x) + 1 + >>> pprint(sd(f2, x, S.Reals), use_unicode=False) + 3*pi + {2*n*pi + ---- | n in Integers} + 2 + >>> f3 = sin(x + 2) + >>> pprint(sd(f3, x, S.Reals), use_unicode=False) + {2*n*pi - 2 | n in Integers} U {2*n*pi - 2 + pi | n in Integers} + + """ + from sympy.solvers.decompogen import decompogen + # decompose the given function + g_s = decompogen(f, symbol) + # `y_s` represents the set of values for which the function `g` is to be + # solved. + # `solutions` represent the solutions of the equations `g = y_s` or + # `g = 0` depending on the type of `y_s`. + # As we are interested in solving the equation: f = 0 + y_s = FiniteSet(0) + for g in g_s: + frange = function_range(g, symbol, domain) + y_s = Intersection(frange, y_s) + result = S.EmptySet + if isinstance(y_s, FiniteSet): + for y in y_s: + solutions = solveset(Eq(g, y), symbol, domain) + if not isinstance(solutions, ConditionSet): + result += solutions + + else: + if isinstance(y_s, ImageSet): + iter_iset = (y_s,) + + elif isinstance(y_s, Union): + iter_iset = y_s.args + + elif y_s is S.EmptySet: + # y_s is not in the range of g in g_s, so no solution exists + #in the given domain + return S.EmptySet + + for iset in iter_iset: + new_solutions = solveset(Eq(iset.lamda.expr, g), symbol, domain) + dummy_var = tuple(iset.lamda.expr.free_symbols)[0] + (base_set,) = iset.base_sets + if isinstance(new_solutions, FiniteSet): + new_exprs = new_solutions + + elif isinstance(new_solutions, Intersection): + if isinstance(new_solutions.args[1], FiniteSet): + new_exprs = new_solutions.args[1] + + for new_expr in new_exprs: + result += ImageSet(Lambda(dummy_var, new_expr), base_set) + + if result is S.EmptySet: + return ConditionSet(symbol, Eq(f, 0), domain) + + y_s = result + + return y_s + + +def _solveset(f, symbol, domain, _check=False): + """Helper for solveset to return a result from an expression + that has already been sympify'ed and is known to contain the + given symbol.""" + # _check controls whether the answer is checked or not + from sympy.simplify.simplify import signsimp + + if isinstance(f, BooleanTrue): + return domain + + orig_f = f + if f.is_Mul: + coeff, f = f.as_independent(symbol, as_Add=False) + if coeff in {S.ComplexInfinity, S.NegativeInfinity, S.Infinity}: + f = together(orig_f) + elif f.is_Add: + a, h = f.as_independent(symbol) + m, h = h.as_independent(symbol, as_Add=False) + if m not in {S.ComplexInfinity, S.Zero, S.Infinity, + S.NegativeInfinity}: + f = a/m + h # XXX condition `m != 0` should be added to soln + + # assign the solvers to use + solver = lambda f, x, domain=domain: _solveset(f, x, domain) + inverter = lambda f, rhs, symbol: _invert(f, rhs, symbol, domain) + + result = S.EmptySet + + if f.expand().is_zero: + return domain + elif not f.has(symbol): + return S.EmptySet + elif f.is_Mul and all(_is_finite_with_finite_vars(m, domain) + for m in f.args): + # if f(x) and g(x) are both finite we can say that the solution of + # f(x)*g(x) == 0 is same as Union(f(x) == 0, g(x) == 0) is not true in + # general. g(x) can grow to infinitely large for the values where + # f(x) == 0. To be sure that we are not silently allowing any + # wrong solutions we are using this technique only if both f and g are + # finite for a finite input. + result = Union(*[solver(m, symbol) for m in f.args]) + elif (_is_function_class_equation(TrigonometricFunction, f, symbol) or \ + _is_function_class_equation(HyperbolicFunction, f, symbol)): + result = _solve_trig(f, symbol, domain) + elif isinstance(f, arg): + a = f.args[0] + result = Intersection(_solveset(re(a) > 0, symbol, domain), + _solveset(im(a), symbol, domain)) + elif f.is_Piecewise: + expr_set_pairs = f.as_expr_set_pairs(domain) + for (expr, in_set) in expr_set_pairs: + if in_set.is_Relational: + in_set = in_set.as_set() + solns = solver(expr, symbol, in_set) + result += solns + elif isinstance(f, Eq): + result = solver(Add(f.lhs, -f.rhs, evaluate=False), symbol, domain) + + elif f.is_Relational: + from .inequalities import solve_univariate_inequality + try: + result = solve_univariate_inequality( + f, symbol, domain=domain, relational=False) + except NotImplementedError: + result = ConditionSet(symbol, f, domain) + return result + elif _is_modular(f, symbol): + result = _solve_modular(f, symbol, domain) + else: + lhs, rhs_s = inverter(f, 0, symbol) + if lhs == symbol: + # do some very minimal simplification since + # repeated inversion may have left the result + # in a state that other solvers (e.g. poly) + # would have simplified; this is done here + # rather than in the inverter since here it + # is only done once whereas there it would + # be repeated for each step of the inversion + if isinstance(rhs_s, FiniteSet): + rhs_s = FiniteSet(*[Mul(* + signsimp(i).as_content_primitive()) + for i in rhs_s]) + result = rhs_s + + elif isinstance(rhs_s, FiniteSet): + for equation in [lhs - rhs for rhs in rhs_s]: + if equation == f: + u = unrad(f, symbol) + if u: + result += _solve_radical(equation, u, + symbol, + solver) + elif equation.has(Abs): + result += _solve_abs(f, symbol, domain) + else: + result_rational = _solve_as_rational(equation, symbol, domain) + if not isinstance(result_rational, ConditionSet): + result += result_rational + else: + # may be a transcendental type equation + t_result = _transolve(equation, symbol, domain) + if isinstance(t_result, ConditionSet): + # might need factoring; this is expensive so we + # have delayed until now. To avoid recursion + # errors look for a non-trivial factoring into + # a product of symbol dependent terms; I think + # that something that factors as a Pow would + # have already been recognized by now. + factored = equation.factor() + if factored.is_Mul and equation != factored: + _, dep = factored.as_independent(symbol) + if not dep.is_Add: + # non-trivial factoring of equation + # but use form with constants + # in case they need special handling + t_results = [] + for fac in Mul.make_args(factored): + if fac.has(symbol): + t_results.append(solver(fac, symbol)) + t_result = Union(*t_results) + result += t_result + else: + result += solver(equation, symbol) + + elif rhs_s is not S.EmptySet: + result = ConditionSet(symbol, Eq(f, 0), domain) + + if isinstance(result, ConditionSet): + if isinstance(f, Expr): + num, den = f.as_numer_denom() + if den.has(symbol): + _result = _solveset(num, symbol, domain) + if not isinstance(_result, ConditionSet): + singularities = _solveset(den, symbol, domain) + result = _result - singularities + + if _check: + if isinstance(result, ConditionSet): + # it wasn't solved or has enumerated all conditions + # -- leave it alone + return result + + # whittle away all but the symbol-containing core + # to use this for testing + if isinstance(orig_f, Expr): + fx = orig_f.as_independent(symbol, as_Add=True)[1] + fx = fx.as_independent(symbol, as_Add=False)[1] + else: + fx = orig_f + + if isinstance(result, FiniteSet): + # check the result for invalid solutions + result = FiniteSet(*[s for s in result + if isinstance(s, RootOf) + or domain_check(fx, symbol, s)]) + + return result + + +def _is_modular(f, symbol): + """ + Helper function to check below mentioned types of modular equations. + ``A - Mod(B, C) = 0`` + + A -> This can or cannot be a function of symbol. + B -> This is surely a function of symbol. + C -> It is an integer. + + Parameters + ========== + + f : Expr + The equation to be checked. + + symbol : Symbol + The concerned variable for which the equation is to be checked. + + Examples + ======== + + >>> from sympy import symbols, exp, Mod + >>> from sympy.solvers.solveset import _is_modular as check + >>> x, y = symbols('x y') + >>> check(Mod(x, 3) - 1, x) + True + >>> check(Mod(x, 3) - 1, y) + False + >>> check(Mod(x, 3)**2 - 5, x) + False + >>> check(Mod(x, 3)**2 - y, x) + False + >>> check(exp(Mod(x, 3)) - 1, x) + False + >>> check(Mod(3, y) - 1, y) + False + """ + + if not f.has(Mod): + return False + + # extract modterms from f. + modterms = list(f.atoms(Mod)) + + return (len(modterms) == 1 and # only one Mod should be present + modterms[0].args[0].has(symbol) and # B-> function of symbol + modterms[0].args[1].is_integer and # C-> to be an integer. + any(isinstance(term, Mod) + for term in list(_term_factors(f))) # free from other funcs + ) + + +def _invert_modular(modterm, rhs, n, symbol): + """ + Helper function to invert modular equation. + ``Mod(a, m) - rhs = 0`` + + Generally it is inverted as (a, ImageSet(Lambda(n, m*n + rhs), S.Integers)). + More simplified form will be returned if possible. + + If it is not invertible then (modterm, rhs) is returned. + + The following cases arise while inverting equation ``Mod(a, m) - rhs = 0``: + + 1. If a is symbol then m*n + rhs is the required solution. + + 2. If a is an instance of ``Add`` then we try to find two symbol independent + parts of a and the symbol independent part gets transferred to the other + side and again the ``_invert_modular`` is called on the symbol + dependent part. + + 3. If a is an instance of ``Mul`` then same as we done in ``Add`` we separate + out the symbol dependent and symbol independent parts and transfer the + symbol independent part to the rhs with the help of invert and again the + ``_invert_modular`` is called on the symbol dependent part. + + 4. If a is an instance of ``Pow`` then two cases arise as following: + + - If a is of type (symbol_indep)**(symbol_dep) then the remainder is + evaluated with the help of discrete_log function and then the least + period is being found out with the help of totient function. + period*n + remainder is the required solution in this case. + For reference: (https://en.wikipedia.org/wiki/Euler's_theorem) + + - If a is of type (symbol_dep)**(symbol_indep) then we try to find all + primitive solutions list with the help of nthroot_mod function. + m*n + rem is the general solution where rem belongs to solutions list + from nthroot_mod function. + + Parameters + ========== + + modterm, rhs : Expr + The modular equation to be inverted, ``modterm - rhs = 0`` + + symbol : Symbol + The variable in the equation to be inverted. + + n : Dummy + Dummy variable for output g_n. + + Returns + ======= + + A tuple (f_x, g_n) is being returned where f_x is modular independent function + of symbol and g_n being set of values f_x can have. + + Examples + ======== + + >>> from sympy import symbols, exp, Mod, Dummy, S + >>> from sympy.solvers.solveset import _invert_modular as invert_modular + >>> x, y = symbols('x y') + >>> n = Dummy('n') + >>> invert_modular(Mod(exp(x), 7), S(5), n, x) + (Mod(exp(x), 7), 5) + >>> invert_modular(Mod(x, 7), S(5), n, x) + (x, ImageSet(Lambda(_n, 7*_n + 5), Integers)) + >>> invert_modular(Mod(3*x + 8, 7), S(5), n, x) + (x, ImageSet(Lambda(_n, 7*_n + 6), Integers)) + >>> invert_modular(Mod(x**4, 7), S(5), n, x) + (x, EmptySet) + >>> invert_modular(Mod(2**(x**2 + x + 1), 7), S(2), n, x) + (x**2 + x + 1, ImageSet(Lambda(_n, 3*_n + 1), Naturals0)) + + """ + a, m = modterm.args + + if rhs.is_integer is False: + return symbol, S.EmptySet + + if rhs.is_real is False or any(term.is_real is False + for term in list(_term_factors(a))): + # Check for complex arguments + return modterm, rhs + + if abs(rhs) >= abs(m): + # if rhs has value greater than value of m. + return symbol, S.EmptySet + + if a == symbol: + return symbol, ImageSet(Lambda(n, m*n + rhs), S.Integers) + + if a.is_Add: + # g + h = a + g, h = a.as_independent(symbol) + if g is not S.Zero: + x_indep_term = rhs - Mod(g, m) + return _invert_modular(Mod(h, m), Mod(x_indep_term, m), n, symbol) + + if a.is_Mul: + # g*h = a + g, h = a.as_independent(symbol) + if g is not S.One: + x_indep_term = rhs*invert(g, m) + return _invert_modular(Mod(h, m), Mod(x_indep_term, m), n, symbol) + + if a.is_Pow: + # base**expo = a + base, expo = a.args + if expo.has(symbol) and not base.has(symbol): + # remainder -> solution independent of n of equation. + # m, rhs are made coprime by dividing number_gcd(m, rhs) + if not m.is_Integer and rhs.is_Integer and a.base.is_Integer: + return modterm, rhs + + mdiv = m.p // number_gcd(m.p, rhs.p) + try: + remainder = discrete_log(mdiv, rhs.p, a.base.p) + except ValueError: # log does not exist + return modterm, rhs + # period -> coefficient of n in the solution and also referred as + # the least period of expo in which it is repeats itself. + # (a**(totient(m)) - 1) divides m. Here is link of theorem: + # (https://en.wikipedia.org/wiki/Euler's_theorem) + period = totient(m) + for p in divisors(period): + # there might a lesser period exist than totient(m). + if pow(a.base, p, m / number_gcd(m.p, a.base.p)) == 1: + period = p + break + # recursion is not applied here since _invert_modular is currently + # not smart enough to handle infinite rhs as here expo has infinite + # rhs = ImageSet(Lambda(n, period*n + remainder), S.Naturals0). + return expo, ImageSet(Lambda(n, period*n + remainder), S.Naturals0) + elif base.has(symbol) and not expo.has(symbol): + try: + remainder_list = nthroot_mod(rhs, expo, m, all_roots=True) + if remainder_list == []: + return symbol, S.EmptySet + except (ValueError, NotImplementedError): + return modterm, rhs + g_n = S.EmptySet + for rem in remainder_list: + g_n += ImageSet(Lambda(n, m*n + rem), S.Integers) + return base, g_n + + return modterm, rhs + + +def _solve_modular(f, symbol, domain): + r""" + Helper function for solving modular equations of type ``A - Mod(B, C) = 0``, + where A can or cannot be a function of symbol, B is surely a function of + symbol and C is an integer. + + Currently ``_solve_modular`` is only able to solve cases + where A is not a function of symbol. + + Parameters + ========== + + f : Expr + The modular equation to be solved, ``f = 0`` + + symbol : Symbol + The variable in the equation to be solved. + + domain : Set + A set over which the equation is solved. It has to be a subset of + Integers. + + Returns + ======= + + A set of integer solutions satisfying the given modular equation. + A ``ConditionSet`` if the equation is unsolvable. + + Examples + ======== + + >>> from sympy.solvers.solveset import _solve_modular as solve_modulo + >>> from sympy import S, Symbol, sin, Intersection, Interval, Mod + >>> x = Symbol('x') + >>> solve_modulo(Mod(5*x - 8, 7) - 3, x, S.Integers) + ImageSet(Lambda(_n, 7*_n + 5), Integers) + >>> solve_modulo(Mod(5*x - 8, 7) - 3, x, S.Reals) # domain should be subset of integers. + ConditionSet(x, Eq(Mod(5*x + 6, 7) - 3, 0), Reals) + >>> solve_modulo(-7 + Mod(x, 5), x, S.Integers) + EmptySet + >>> solve_modulo(Mod(12**x, 21) - 18, x, S.Integers) + ImageSet(Lambda(_n, 6*_n + 2), Naturals0) + >>> solve_modulo(Mod(sin(x), 7) - 3, x, S.Integers) # not solvable + ConditionSet(x, Eq(Mod(sin(x), 7) - 3, 0), Integers) + >>> solve_modulo(3 - Mod(x, 5), x, Intersection(S.Integers, Interval(0, 100))) + Intersection(ImageSet(Lambda(_n, 5*_n + 3), Integers), Range(0, 101, 1)) + """ + # extract modterm and g_y from f + unsolved_result = ConditionSet(symbol, Eq(f, 0), domain) + modterm = list(f.atoms(Mod))[0] + rhs = -S.One*(f.subs(modterm, S.Zero)) + if f.as_coefficients_dict()[modterm].is_negative: + # checks if coefficient of modterm is negative in main equation. + rhs *= -S.One + + if not domain.is_subset(S.Integers): + return unsolved_result + + if rhs.has(symbol): + # TODO Case: A-> function of symbol, can be extended here + # in future. + return unsolved_result + + n = Dummy('n', integer=True) + f_x, g_n = _invert_modular(modterm, rhs, n, symbol) + + if f_x == modterm and g_n == rhs: + return unsolved_result + + if f_x == symbol: + if domain is not S.Integers: + return domain.intersect(g_n) + return g_n + + if isinstance(g_n, ImageSet): + lamda_expr = g_n.lamda.expr + lamda_vars = g_n.lamda.variables + base_sets = g_n.base_sets + sol_set = _solveset(f_x - lamda_expr, symbol, S.Integers) + if isinstance(sol_set, FiniteSet): + tmp_sol = S.EmptySet + for sol in sol_set: + tmp_sol += ImageSet(Lambda(lamda_vars, sol), *base_sets) + sol_set = tmp_sol + else: + sol_set = ImageSet(Lambda(lamda_vars, sol_set), *base_sets) + return domain.intersect(sol_set) + + return unsolved_result + + +def _term_factors(f): + """ + Iterator to get the factors of all terms present + in the given equation. + + Parameters + ========== + f : Expr + Equation that needs to be addressed + + Returns + ======= + Factors of all terms present in the equation. + + Examples + ======== + + >>> from sympy import symbols + >>> from sympy.solvers.solveset import _term_factors + >>> x = symbols('x') + >>> list(_term_factors(-2 - x**2 + x*(x + 1))) + [-2, -1, x**2, x, x + 1] + """ + for add_arg in Add.make_args(f): + yield from Mul.make_args(add_arg) + + +def _solve_exponential(lhs, rhs, symbol, domain): + r""" + Helper function for solving (supported) exponential equations. + + Exponential equations are the sum of (currently) at most + two terms with one or both of them having a power with a + symbol-dependent exponent. + + For example + + .. math:: 5^{2x + 3} - 5^{3x - 1} + + .. math:: 4^{5 - 9x} - e^{2 - x} + + Parameters + ========== + + lhs, rhs : Expr + The exponential equation to be solved, `lhs = rhs` + + symbol : Symbol + The variable in which the equation is solved + + domain : Set + A set over which the equation is solved. + + Returns + ======= + + A set of solutions satisfying the given equation. + A ``ConditionSet`` if the equation is unsolvable or + if the assumptions are not properly defined, in that case + a different style of ``ConditionSet`` is returned having the + solution(s) of the equation with the desired assumptions. + + Examples + ======== + + >>> from sympy.solvers.solveset import _solve_exponential as solve_expo + >>> from sympy import symbols, S + >>> x = symbols('x', real=True) + >>> a, b = symbols('a b') + >>> solve_expo(2**x + 3**x - 5**x, 0, x, S.Reals) # not solvable + ConditionSet(x, Eq(2**x + 3**x - 5**x, 0), Reals) + >>> solve_expo(a**x - b**x, 0, x, S.Reals) # solvable but incorrect assumptions + ConditionSet(x, (a > 0) & (b > 0), {0}) + >>> solve_expo(3**(2*x) - 2**(x + 3), 0, x, S.Reals) + {-3*log(2)/(-2*log(3) + log(2))} + >>> solve_expo(2**x - 4**x, 0, x, S.Reals) + {0} + + * Proof of correctness of the method + + The logarithm function is the inverse of the exponential function. + The defining relation between exponentiation and logarithm is: + + .. math:: {\log_b x} = y \enspace if \enspace b^y = x + + Therefore if we are given an equation with exponent terms, we can + convert every term to its corresponding logarithmic form. This is + achieved by taking logarithms and expanding the equation using + logarithmic identities so that it can easily be handled by ``solveset``. + + For example: + + .. math:: 3^{2x} = 2^{x + 3} + + Taking log both sides will reduce the equation to + + .. math:: (2x)\log(3) = (x + 3)\log(2) + + This form can be easily handed by ``solveset``. + """ + unsolved_result = ConditionSet(symbol, Eq(lhs - rhs, 0), domain) + newlhs = powdenest(lhs) + if lhs != newlhs: + # it may also be advantageous to factor the new expr + neweq = factor(newlhs - rhs) + if neweq != (lhs - rhs): + return _solveset(neweq, symbol, domain) # try again with _solveset + + if not (isinstance(lhs, Add) and len(lhs.args) == 2): + # solving for the sum of more than two powers is possible + # but not yet implemented + return unsolved_result + + if rhs != 0: + return unsolved_result + + a, b = list(ordered(lhs.args)) + a_term = a.as_independent(symbol)[1] + b_term = b.as_independent(symbol)[1] + + a_base, a_exp = a_term.as_base_exp() + b_base, b_exp = b_term.as_base_exp() + + if domain.is_subset(S.Reals): + conditions = And( + a_base > 0, + b_base > 0, + Eq(im(a_exp), 0), + Eq(im(b_exp), 0)) + else: + conditions = And( + Ne(a_base, 0), + Ne(b_base, 0)) + + L, R = (expand_log(log(i), force=True) for i in (a, -b)) + solutions = _solveset(L - R, symbol, domain) + + return ConditionSet(symbol, conditions, solutions) + + +def _is_exponential(f, symbol): + r""" + Return ``True`` if one or more terms contain ``symbol`` only in + exponents, else ``False``. + + Parameters + ========== + + f : Expr + The equation to be checked + + symbol : Symbol + The variable in which the equation is checked + + Examples + ======== + + >>> from sympy import symbols, cos, exp + >>> from sympy.solvers.solveset import _is_exponential as check + >>> x, y = symbols('x y') + >>> check(y, y) + False + >>> check(x**y - 1, y) + True + >>> check(x**y*2**y - 1, y) + True + >>> check(exp(x + 3) + 3**x, x) + True + >>> check(cos(2**x), x) + False + + * Philosophy behind the helper + + The function extracts each term of the equation and checks if it is + of exponential form w.r.t ``symbol``. + """ + rv = False + for expr_arg in _term_factors(f): + if symbol not in expr_arg.free_symbols: + continue + if (isinstance(expr_arg, Pow) and + symbol not in expr_arg.base.free_symbols or + isinstance(expr_arg, exp)): + rv = True # symbol in exponent + else: + return False # dependent on symbol in non-exponential way + return rv + + +def _solve_logarithm(lhs, rhs, symbol, domain): + r""" + Helper to solve logarithmic equations which are reducible + to a single instance of `\log`. + + Logarithmic equations are (currently) the equations that contains + `\log` terms which can be reduced to a single `\log` term or + a constant using various logarithmic identities. + + For example: + + .. math:: \log(x) + \log(x - 4) + + can be reduced to: + + .. math:: \log(x(x - 4)) + + Parameters + ========== + + lhs, rhs : Expr + The logarithmic equation to be solved, `lhs = rhs` + + symbol : Symbol + The variable in which the equation is solved + + domain : Set + A set over which the equation is solved. + + Returns + ======= + + A set of solutions satisfying the given equation. + A ``ConditionSet`` if the equation is unsolvable. + + Examples + ======== + + >>> from sympy import symbols, log, S + >>> from sympy.solvers.solveset import _solve_logarithm as solve_log + >>> x = symbols('x') + >>> f = log(x - 3) + log(x + 3) + >>> solve_log(f, 0, x, S.Reals) + {-sqrt(10), sqrt(10)} + + * Proof of correctness + + A logarithm is another way to write exponent and is defined by + + .. math:: {\log_b x} = y \enspace if \enspace b^y = x + + When one side of the equation contains a single logarithm, the + equation can be solved by rewriting the equation as an equivalent + exponential equation as defined above. But if one side contains + more than one logarithm, we need to use the properties of logarithm + to condense it into a single logarithm. + + Take for example + + .. math:: \log(2x) - 15 = 0 + + contains single logarithm, therefore we can directly rewrite it to + exponential form as + + .. math:: x = \frac{e^{15}}{2} + + But if the equation has more than one logarithm as + + .. math:: \log(x - 3) + \log(x + 3) = 0 + + we use logarithmic identities to convert it into a reduced form + + Using, + + .. math:: \log(a) + \log(b) = \log(ab) + + the equation becomes, + + .. math:: \log((x - 3)(x + 3)) + + This equation contains one logarithm and can be solved by rewriting + to exponents. + """ + new_lhs = logcombine(lhs, force=True) + new_f = new_lhs - rhs + + return _solveset(new_f, symbol, domain) + + +def _is_logarithmic(f, symbol): + r""" + Return ``True`` if the equation is in the form + `a\log(f(x)) + b\log(g(x)) + ... + c` else ``False``. + + Parameters + ========== + + f : Expr + The equation to be checked + + symbol : Symbol + The variable in which the equation is checked + + Returns + ======= + + ``True`` if the equation is logarithmic otherwise ``False``. + + Examples + ======== + + >>> from sympy import symbols, tan, log + >>> from sympy.solvers.solveset import _is_logarithmic as check + >>> x, y = symbols('x y') + >>> check(log(x + 2) - log(x + 3), x) + True + >>> check(tan(log(2*x)), x) + False + >>> check(x*log(x), x) + False + >>> check(x + log(x), x) + False + >>> check(y + log(x), x) + True + + * Philosophy behind the helper + + The function extracts each term and checks whether it is + logarithmic w.r.t ``symbol``. + """ + rv = False + for term in Add.make_args(f): + saw_log = False + for term_arg in Mul.make_args(term): + if symbol not in term_arg.free_symbols: + continue + if isinstance(term_arg, log): + if saw_log: + return False # more than one log in term + saw_log = True + else: + return False # dependent on symbol in non-log way + if saw_log: + rv = True + return rv + + +def _is_lambert(f, symbol): + r""" + If this returns ``False`` then the Lambert solver (``_solve_lambert``) will not be called. + + Explanation + =========== + + Quick check for cases that the Lambert solver might be able to handle. + + 1. Equations containing more than two operands and `symbol`s involving any of + `Pow`, `exp`, `HyperbolicFunction`,`TrigonometricFunction`, `log` terms. + + 2. In `Pow`, `exp` the exponent should have `symbol` whereas for + `HyperbolicFunction`,`TrigonometricFunction`, `log` should contain `symbol`. + + 3. For `HyperbolicFunction`,`TrigonometricFunction` the number of trigonometric functions in + equation should be less than number of symbols. (since `A*cos(x) + B*sin(x) - c` + is not the Lambert type). + + Some forms of lambert equations are: + 1. X**X = C + 2. X*(B*log(X) + D)**A = C + 3. A*log(B*X + A) + d*X = C + 4. (B*X + A)*exp(d*X + g) = C + 5. g*exp(B*X + h) - B*X = C + 6. A*D**(E*X + g) - B*X = C + 7. A*cos(X) + B*sin(X) - D*X = C + 8. A*cosh(X) + B*sinh(X) - D*X = C + + Where X is any variable, + A, B, C, D, E are any constants, + g, h are linear functions or log terms. + + Parameters + ========== + + f : Expr + The equation to be checked + + symbol : Symbol + The variable in which the equation is checked + + Returns + ======= + + If this returns ``False`` then the Lambert solver (``_solve_lambert``) will not be called. + + Examples + ======== + + >>> from sympy.solvers.solveset import _is_lambert + >>> from sympy import symbols, cosh, sinh, log + >>> x = symbols('x') + + >>> _is_lambert(3*log(x) - x*log(3), x) + True + >>> _is_lambert(log(log(x - 3)) + log(x-3), x) + True + >>> _is_lambert(cosh(x) - sinh(x), x) + False + >>> _is_lambert((x**2 - 2*x + 1).subs(x, (log(x) + 3*x)**2 - 1), x) + True + + See Also + ======== + + _solve_lambert + + """ + term_factors = list(_term_factors(f.expand())) + + # total number of symbols in equation + no_of_symbols = len([arg for arg in term_factors if arg.has(symbol)]) + # total number of trigonometric terms in equation + no_of_trig = len([arg for arg in term_factors \ + if arg.has(HyperbolicFunction, TrigonometricFunction)]) + + if f.is_Add and no_of_symbols >= 2: + # `log`, `HyperbolicFunction`, `TrigonometricFunction` should have symbols + # and no_of_trig < no_of_symbols + lambert_funcs = (log, HyperbolicFunction, TrigonometricFunction) + if any(isinstance(arg, lambert_funcs)\ + for arg in term_factors if arg.has(symbol)): + if no_of_trig < no_of_symbols: + return True + # here, `Pow`, `exp` exponent should have symbols + elif any(isinstance(arg, (Pow, exp)) \ + for arg in term_factors if (arg.as_base_exp()[1]).has(symbol)): + return True + return False + + +def _transolve(f, symbol, domain): + r""" + Function to solve transcendental equations. It is a helper to + ``solveset`` and should be used internally. ``_transolve`` + currently supports the following class of equations: + + - Exponential equations + - Logarithmic equations + + Parameters + ========== + + f : Any transcendental equation that needs to be solved. + This needs to be an expression, which is assumed + to be equal to ``0``. + + symbol : The variable for which the equation is solved. + This needs to be of class ``Symbol``. + + domain : A set over which the equation is solved. + This needs to be of class ``Set``. + + Returns + ======= + + Set + A set of values for ``symbol`` for which ``f`` is equal to + zero. An ``EmptySet`` is returned if ``f`` does not have solutions + in respective domain. A ``ConditionSet`` is returned as unsolved + object if algorithms to evaluate complete solution are not + yet implemented. + + How to use ``_transolve`` + ========================= + + ``_transolve`` should not be used as an independent function, because + it assumes that the equation (``f``) and the ``symbol`` comes from + ``solveset`` and might have undergone a few modification(s). + To use ``_transolve`` as an independent function the equation (``f``) + and the ``symbol`` should be passed as they would have been by + ``solveset``. + + Examples + ======== + + >>> from sympy.solvers.solveset import _transolve as transolve + >>> from sympy.solvers.solvers import _tsolve as tsolve + >>> from sympy import symbols, S, pprint + >>> x = symbols('x', real=True) # assumption added + >>> transolve(5**(x - 3) - 3**(2*x + 1), x, S.Reals) + {-(log(3) + 3*log(5))/(-log(5) + 2*log(3))} + + How ``_transolve`` works + ======================== + + ``_transolve`` uses two types of helper functions to solve equations + of a particular class: + + Identifying helpers: To determine whether a given equation + belongs to a certain class of equation or not. Returns either + ``True`` or ``False``. + + Solving helpers: Once an equation is identified, a corresponding + helper either solves the equation or returns a form of the equation + that ``solveset`` might better be able to handle. + + * Philosophy behind the module + + The purpose of ``_transolve`` is to take equations which are not + already polynomial in their generator(s) and to either recast them + as such through a valid transformation or to solve them outright. + A pair of helper functions for each class of supported + transcendental functions are employed for this purpose. One + identifies the transcendental form of an equation and the other + either solves it or recasts it into a tractable form that can be + solved by ``solveset``. + For example, an equation in the form `ab^{f(x)} - cd^{g(x)} = 0` + can be transformed to + `\log(a) + f(x)\log(b) - \log(c) - g(x)\log(d) = 0` + (under certain assumptions) and this can be solved with ``solveset`` + if `f(x)` and `g(x)` are in polynomial form. + + How ``_transolve`` is better than ``_tsolve`` + ============================================= + + 1) Better output + + ``_transolve`` provides expressions in a more simplified form. + + Consider a simple exponential equation + + >>> f = 3**(2*x) - 2**(x + 3) + >>> pprint(transolve(f, x, S.Reals), use_unicode=False) + -3*log(2) + {------------------} + -2*log(3) + log(2) + >>> pprint(tsolve(f, x), use_unicode=False) + / 3 \ + | --------| + | log(2/9)| + [-log\2 /] + + 2) Extensible + + The API of ``_transolve`` is designed such that it is easily + extensible, i.e. the code that solves a given class of + equations is encapsulated in a helper and not mixed in with + the code of ``_transolve`` itself. + + 3) Modular + + ``_transolve`` is designed to be modular i.e, for every class of + equation a separate helper for identification and solving is + implemented. This makes it easy to change or modify any of the + method implemented directly in the helpers without interfering + with the actual structure of the API. + + 4) Faster Computation + + Solving equation via ``_transolve`` is much faster as compared to + ``_tsolve``. In ``solve``, attempts are made computing every possibility + to get the solutions. This series of attempts makes solving a bit + slow. In ``_transolve``, computation begins only after a particular + type of equation is identified. + + How to add new class of equations + ================================= + + Adding a new class of equation solver is a three-step procedure: + + - Identify the type of the equations + + Determine the type of the class of equations to which they belong: + it could be of ``Add``, ``Pow``, etc. types. Separate internal functions + are used for each type. Write identification and solving helpers + and use them from within the routine for the given type of equation + (after adding it, if necessary). Something like: + + .. code-block:: python + + def add_type(lhs, rhs, x): + .... + if _is_exponential(lhs, x): + new_eq = _solve_exponential(lhs, rhs, x) + .... + rhs, lhs = eq.as_independent(x) + if lhs.is_Add: + result = add_type(lhs, rhs, x) + + - Define the identification helper. + + - Define the solving helper. + + Apart from this, a few other things needs to be taken care while + adding an equation solver: + + - Naming conventions: + Name of the identification helper should be as + ``_is_class`` where class will be the name or abbreviation + of the class of equation. The solving helper will be named as + ``_solve_class``. + For example: for exponential equations it becomes + ``_is_exponential`` and ``_solve_expo``. + - The identifying helpers should take two input parameters, + the equation to be checked and the variable for which a solution + is being sought, while solving helpers would require an additional + domain parameter. + - Be sure to consider corner cases. + - Add tests for each helper. + - Add a docstring to your helper that describes the method + implemented. + The documentation of the helpers should identify: + + - the purpose of the helper, + - the method used to identify and solve the equation, + - a proof of correctness + - the return values of the helpers + """ + + def add_type(lhs, rhs, symbol, domain): + """ + Helper for ``_transolve`` to handle equations of + ``Add`` type, i.e. equations taking the form as + ``a*f(x) + b*g(x) + .... = c``. + For example: 4**x + 8**x = 0 + """ + result = ConditionSet(symbol, Eq(lhs - rhs, 0), domain) + + # check if it is exponential type equation + if _is_exponential(lhs, symbol): + result = _solve_exponential(lhs, rhs, symbol, domain) + # check if it is logarithmic type equation + elif _is_logarithmic(lhs, symbol): + result = _solve_logarithm(lhs, rhs, symbol, domain) + + return result + + result = ConditionSet(symbol, Eq(f, 0), domain) + + # invert_complex handles the call to the desired inverter based + # on the domain specified. + lhs, rhs_s = invert_complex(f, 0, symbol, domain) + + if isinstance(rhs_s, FiniteSet): + assert (len(rhs_s.args)) == 1 + rhs = rhs_s.args[0] + + if lhs.is_Add: + result = add_type(lhs, rhs, symbol, domain) + else: + result = rhs_s + + return result + + +def solveset(f, symbol=None, domain=S.Complexes): + r"""Solves a given inequality or equation with set as output + + Parameters + ========== + + f : Expr or a relational. + The target equation or inequality + symbol : Symbol + The variable for which the equation is solved + domain : Set + The domain over which the equation is solved + + Returns + ======= + + Set + A set of values for `symbol` for which `f` is True or is equal to + zero. An :class:`~.EmptySet` is returned if `f` is False or nonzero. + A :class:`~.ConditionSet` is returned as unsolved object if algorithms + to evaluate complete solution are not yet implemented. + + ``solveset`` claims to be complete in the solution set that it returns. + + Raises + ====== + + NotImplementedError + The algorithms to solve inequalities in complex domain are + not yet implemented. + ValueError + The input is not valid. + RuntimeError + It is a bug, please report to the github issue tracker. + + + Notes + ===== + + Python interprets 0 and 1 as False and True, respectively, but + in this function they refer to solutions of an expression. So 0 and 1 + return the domain and EmptySet, respectively, while True and False + return the opposite (as they are assumed to be solutions of relational + expressions). + + + See Also + ======== + + solveset_real: solver for real domain + solveset_complex: solver for complex domain + + Examples + ======== + + >>> from sympy import exp, sin, Symbol, pprint, S, Eq + >>> from sympy.solvers.solveset import solveset, solveset_real + + * The default domain is complex. Not specifying a domain will lead + to the solving of the equation in the complex domain (and this + is not affected by the assumptions on the symbol): + + >>> x = Symbol('x') + >>> pprint(solveset(exp(x) - 1, x), use_unicode=False) + {2*n*I*pi | n in Integers} + + >>> x = Symbol('x', real=True) + >>> pprint(solveset(exp(x) - 1, x), use_unicode=False) + {2*n*I*pi | n in Integers} + + * If you want to use ``solveset`` to solve the equation in the + real domain, provide a real domain. (Using ``solveset_real`` + does this automatically.) + + >>> R = S.Reals + >>> x = Symbol('x') + >>> solveset(exp(x) - 1, x, R) + {0} + >>> solveset_real(exp(x) - 1, x) + {0} + + The solution is unaffected by assumptions on the symbol: + + >>> p = Symbol('p', positive=True) + >>> pprint(solveset(p**2 - 4)) + {-2, 2} + + When a :class:`~.ConditionSet` is returned, symbols with assumptions that + would alter the set are replaced with more generic symbols: + + >>> i = Symbol('i', imaginary=True) + >>> solveset(Eq(i**2 + i*sin(i), 1), i, domain=S.Reals) + ConditionSet(_R, Eq(_R**2 + _R*sin(_R) - 1, 0), Reals) + + * Inequalities can be solved over the real domain only. Use of a complex + domain leads to a NotImplementedError. + + >>> solveset(exp(x) > 1, x, R) + Interval.open(0, oo) + + """ + f = sympify(f) + symbol = sympify(symbol) + + if f is S.true: + return domain + + if f is S.false: + return S.EmptySet + + if not isinstance(f, (Expr, Relational, Number)): + raise ValueError("%s is not a valid SymPy expression" % f) + + if not isinstance(symbol, (Expr, Relational)) and symbol is not None: + raise ValueError("%s is not a valid SymPy symbol" % (symbol,)) + + if not isinstance(domain, Set): + raise ValueError("%s is not a valid domain" %(domain)) + + free_symbols = f.free_symbols + + if f.has(Piecewise): + f = piecewise_fold(f) + + if symbol is None and not free_symbols: + b = Eq(f, 0) + if b is S.true: + return domain + elif b is S.false: + return S.EmptySet + else: + raise NotImplementedError(filldedent(''' + relationship between value and 0 is unknown: %s''' % b)) + + if symbol is None: + if len(free_symbols) == 1: + symbol = free_symbols.pop() + elif free_symbols: + raise ValueError(filldedent(''' + The independent variable must be specified for a + multivariate equation.''')) + elif not isinstance(symbol, Symbol): + f, s, swap = recast_to_symbols([f], [symbol]) + # the xreplace will be needed if a ConditionSet is returned + return solveset(f[0], s[0], domain).xreplace(swap) + + # solveset should ignore assumptions on symbols + newsym = None + if domain.is_subset(S.Reals): + if symbol._assumptions_orig != {'real': True}: + newsym = Dummy('R', real=True) + elif domain.is_subset(S.Complexes): + if symbol._assumptions_orig != {'complex': True}: + newsym = Dummy('C', complex=True) + + if newsym is not None: + rv = solveset(f.xreplace({symbol: newsym}), newsym, domain) + # try to use the original symbol if possible + try: + _rv = rv.xreplace({newsym: symbol}) + except TypeError: + _rv = rv + if rv.dummy_eq(_rv): + rv = _rv + return rv + + # Abs has its own handling method which avoids the + # rewriting property that the first piece of abs(x) + # is for x >= 0 and the 2nd piece for x < 0 -- solutions + # can look better if the 2nd condition is x <= 0. Since + # the solution is a set, duplication of results is not + # an issue, e.g. {y, -y} when y is 0 will be {0} + f, mask = _masked(f, Abs) + f = f.rewrite(Piecewise) # everything that's not an Abs + for d, e in mask: + # everything *in* an Abs + e = e.func(e.args[0].rewrite(Piecewise)) + f = f.xreplace({d: e}) + f = piecewise_fold(f) + + return _solveset(f, symbol, domain, _check=True) + + +def solveset_real(f, symbol): + return solveset(f, symbol, S.Reals) + + +def solveset_complex(f, symbol): + return solveset(f, symbol, S.Complexes) + + +def _solveset_multi(eqs, syms, domains): + '''Basic implementation of a multivariate solveset. + + For internal use (not ready for public consumption)''' + + rep = {} + for sym, dom in zip(syms, domains): + if dom is S.Reals: + rep[sym] = Symbol(sym.name, real=True) + eqs = [eq.subs(rep) for eq in eqs] + syms = [sym.subs(rep) for sym in syms] + + syms = tuple(syms) + + if len(eqs) == 0: + return ProductSet(*domains) + + if len(syms) == 1: + sym = syms[0] + domain = domains[0] + solsets = [solveset(eq, sym, domain) for eq in eqs] + solset = Intersection(*solsets) + return ImageSet(Lambda((sym,), (sym,)), solset).doit() + + eqs = sorted(eqs, key=lambda eq: len(eq.free_symbols & set(syms))) + + for n, eq in enumerate(eqs): + sols = [] + all_handled = True + for sym in syms: + if sym not in eq.free_symbols: + continue + sol = solveset(eq, sym, domains[syms.index(sym)]) + + if isinstance(sol, FiniteSet): + i = syms.index(sym) + symsp = syms[:i] + syms[i+1:] + domainsp = domains[:i] + domains[i+1:] + eqsp = eqs[:n] + eqs[n+1:] + for s in sol: + eqsp_sub = [eq.subs(sym, s) for eq in eqsp] + sol_others = _solveset_multi(eqsp_sub, symsp, domainsp) + fun = Lambda((symsp,), symsp[:i] + (s,) + symsp[i:]) + sols.append(ImageSet(fun, sol_others).doit()) + else: + all_handled = False + if all_handled: + return Union(*sols) + + +def solvify(f, symbol, domain): + """Solves an equation using solveset and returns the solution in accordance + with the `solve` output API. + + Returns + ======= + + We classify the output based on the type of solution returned by `solveset`. + + Solution | Output + ---------------------------------------- + FiniteSet | list + + ImageSet, | list (if `f` is periodic) + Union | + + Union | list (with FiniteSet) + + EmptySet | empty list + + Others | None + + + Raises + ====== + + NotImplementedError + A ConditionSet is the input. + + Examples + ======== + + >>> from sympy.solvers.solveset import solvify + >>> from sympy.abc import x + >>> from sympy import S, tan, sin, exp + >>> solvify(x**2 - 9, x, S.Reals) + [-3, 3] + >>> solvify(sin(x) - 1, x, S.Reals) + [pi/2] + >>> solvify(tan(x), x, S.Reals) + [0] + >>> solvify(exp(x) - 1, x, S.Complexes) + + >>> solvify(exp(x) - 1, x, S.Reals) + [0] + + """ + solution_set = solveset(f, symbol, domain) + result = None + if solution_set is S.EmptySet: + result = [] + + elif isinstance(solution_set, ConditionSet): + raise NotImplementedError('solveset is unable to solve this equation.') + + elif isinstance(solution_set, FiniteSet): + result = list(solution_set) + + else: + period = periodicity(f, symbol) + if period is not None: + solutions = S.EmptySet + iter_solutions = () + if isinstance(solution_set, ImageSet): + iter_solutions = (solution_set,) + elif isinstance(solution_set, Union): + if all(isinstance(i, ImageSet) for i in solution_set.args): + iter_solutions = solution_set.args + + for solution in iter_solutions: + solutions += solution.intersect(Interval(0, period, False, True)) + + if isinstance(solutions, FiniteSet): + result = list(solutions) + + else: + solution = solution_set.intersect(domain) + if isinstance(solution, Union): + # concerned about only FiniteSet with Union but not about ImageSet + # if required could be extend + if any(isinstance(i, FiniteSet) for i in solution.args): + result = [sol for soln in solution.args \ + for sol in soln.args if isinstance(soln,FiniteSet)] + else: + return None + + elif isinstance(solution, FiniteSet): + result += solution + + return result + + +############################################################################### +################################ LINSOLVE ##################################### +############################################################################### + + +def linear_coeffs(eq, *syms, dict=False): + """Return a list whose elements are the coefficients of the + corresponding symbols in the sum of terms in ``eq``. + The additive constant is returned as the last element of the + list. + + Raises + ====== + + NonlinearError + The equation contains a nonlinear term + ValueError + duplicate or unordered symbols are passed + + Parameters + ========== + + dict - (default False) when True, return coefficients as a + dictionary with coefficients keyed to syms that were present; + key 1 gives the constant term + + Examples + ======== + + >>> from sympy.solvers.solveset import linear_coeffs + >>> from sympy.abc import x, y, z + >>> linear_coeffs(3*x + 2*y - 1, x, y) + [3, 2, -1] + + It is not necessary to expand the expression: + + >>> linear_coeffs(x + y*(z*(x*3 + 2) + 3), x) + [3*y*z + 1, y*(2*z + 3)] + + When nonlinear is detected, an error will be raised: + + * even if they would cancel after expansion (so the + situation does not pass silently past the caller's + attention) + + >>> eq = 1/x*(x - 1) + 1/x + >>> linear_coeffs(eq.expand(), x) + [0, 1] + >>> linear_coeffs(eq, x) + Traceback (most recent call last): + ... + NonlinearError: + nonlinear in given generators + + * when there are cross terms + + >>> linear_coeffs(x*(y + 1), x, y) + Traceback (most recent call last): + ... + NonlinearError: + symbol-dependent cross-terms encountered + + * when there are terms that contain an expression + dependent on the symbols that is not linear + + >>> linear_coeffs(x**2, x) + Traceback (most recent call last): + ... + NonlinearError: + nonlinear in given generators + """ + eq = _sympify(eq) + if len(syms) == 1 and iterable(syms[0]) and not isinstance(syms[0], Basic): + raise ValueError('expecting unpacked symbols, *syms') + symset = set(syms) + if len(symset) != len(syms): + raise ValueError('duplicate symbols given') + try: + d, c = _linear_eq_to_dict([eq], symset) + d = d[0] + c = c[0] + except PolyNonlinearError as err: + raise NonlinearError(str(err)) + if dict: + if c: + d[S.One] = c + return d + rv = [S.Zero]*(len(syms) + 1) + rv[-1] = c + for i, k in enumerate(syms): + if k not in d: + continue + rv[i] = d[k] + return rv + + +def linear_eq_to_matrix(equations, *symbols): + r""" + Converts a given System of Equations into Matrix form. Here ``equations`` + must be a linear system of equations in ``symbols``. Element ``M[i, j]`` + corresponds to the coefficient of the jth symbol in the ith equation. + + The Matrix form corresponds to the augmented matrix form. For example: + + .. math:: + + 4x + 2y + 3z & = 1 \\ + 3x + y + z & = -6 \\ + 2x + 4y + 9z & = 2 + + This system will return :math:`A` and :math:`b` as: + + .. math:: + + A = \left[\begin{array}{ccc} + 4 & 2 & 3 \\ + 3 & 1 & 1 \\ + 2 & 4 & 9 + \end{array}\right] \\ + + .. math:: + + b = \left[\begin{array}{c} + 1 \\ -6 \\ 2 + \end{array}\right] + + The only simplification performed is to convert + ``Eq(a, b)`` :math:`\Rightarrow a - b`. + + Raises + ====== + + NonlinearError + The equations contain a nonlinear term. + ValueError + The symbols are not given or are not unique. + + Examples + ======== + + >>> from sympy import linear_eq_to_matrix, symbols + >>> c, x, y, z = symbols('c, x, y, z') + + The coefficients (numerical or symbolic) of the symbols will + be returned as matrices: + + >>> eqns = [c*x + z - 1 - c, y + z, x - y] + >>> A, b = linear_eq_to_matrix(eqns, [x, y, z]) + >>> A + Matrix([ + [c, 0, 1], + [0, 1, 1], + [1, -1, 0]]) + >>> b + Matrix([ + [c + 1], + [ 0], + [ 0]]) + + This routine does not simplify expressions and will raise an error + if nonlinearity is encountered: + + >>> eqns = [ + ... (x**2 - 3*x)/(x - 3) - 3, + ... y**2 - 3*y - y*(y - 4) + x - 4] + >>> linear_eq_to_matrix(eqns, [x, y]) + Traceback (most recent call last): + ... + NonlinearError: + symbol-dependent term can be ignored using `strict=False` + + Simplifying these equations will discard the removable singularity in the + first and reveal the linear structure of the second: + + >>> [e.simplify() for e in eqns] + [x - 3, x + y - 4] + + Any such simplification needed to eliminate nonlinear terms must be done + *before* calling this routine. + + """ + if not symbols: + raise ValueError(filldedent(''' + Symbols must be given, for which coefficients + are to be found. + ''')) + + # Check if 'symbols' is a set and raise an error if it is + if isinstance(symbols[0], set): + raise TypeError( + "Unordered 'set' type is not supported as input for symbols.") + + if hasattr(symbols[0], '__iter__'): + symbols = symbols[0] + + if has_dups(symbols): + raise ValueError('Symbols must be unique') + + equations = sympify(equations) + if isinstance(equations, MatrixBase): + equations = list(equations) + elif isinstance(equations, (Expr, Eq)): + equations = [equations] + elif not is_sequence(equations): + raise ValueError(filldedent(''' + Equation(s) must be given as a sequence, Expr, + Eq or Matrix. + ''')) + + # construct the dictionaries + try: + eq, c = _linear_eq_to_dict(equations, symbols) + except PolyNonlinearError as err: + raise NonlinearError(str(err)) + # prepare output matrices + n, m = shape = len(eq), len(symbols) + ix = dict(zip(symbols, range(m))) + A = zeros(*shape) + for row, d in enumerate(eq): + for k in d: + col = ix[k] + A[row, col] = d[k] + b = Matrix(n, 1, [-i for i in c]) + return A, b + + +def linsolve(system, *symbols): + r""" + Solve system of $N$ linear equations with $M$ variables; both + underdetermined and overdetermined systems are supported. + The possible number of solutions is zero, one or infinite. + Zero solutions throws a ValueError, whereas infinite + solutions are represented parametrically in terms of the given + symbols. For unique solution a :class:`~.FiniteSet` of ordered tuples + is returned. + + All standard input formats are supported: + For the given set of equations, the respective input types + are given below: + + .. math:: 3x + 2y - z = 1 + .. math:: 2x - 2y + 4z = -2 + .. math:: 2x - y + 2z = 0 + + * Augmented matrix form, ``system`` given below: + + $$ \text{system} = \left[{array}{cccc} + 3 & 2 & -1 & 1\\ + 2 & -2 & 4 & -2\\ + 2 & -1 & 2 & 0 + \end{array}\right] $$ + + :: + + system = Matrix([[3, 2, -1, 1], [2, -2, 4, -2], [2, -1, 2, 0]]) + + * List of equations form + + :: + + system = [3x + 2y - z - 1, 2x - 2y + 4z + 2, 2x - y + 2z] + + * Input $A$ and $b$ in matrix form (from $Ax = b$) are given as: + + $$ A = \left[\begin{array}{ccc} + 3 & 2 & -1 \\ + 2 & -2 & 4 \\ + 2 & -1 & 2 + \end{array}\right] \ \ b = \left[\begin{array}{c} + 1 \\ -2 \\ 0 + \end{array}\right] $$ + + :: + + A = Matrix([[3, 2, -1], [2, -2, 4], [2, -1, 2]]) + b = Matrix([[1], [-2], [0]]) + system = (A, b) + + Symbols can always be passed but are actually only needed + when 1) a system of equations is being passed and 2) the + system is passed as an underdetermined matrix and one wants + to control the name of the free variables in the result. + An error is raised if no symbols are used for case 1, but if + no symbols are provided for case 2, internally generated symbols + will be provided. When providing symbols for case 2, there should + be at least as many symbols are there are columns in matrix A. + + The algorithm used here is Gauss-Jordan elimination, which + results, after elimination, in a row echelon form matrix. + + Returns + ======= + + A FiniteSet containing an ordered tuple of values for the + unknowns for which the `system` has a solution. (Wrapping + the tuple in FiniteSet is used to maintain a consistent + output format throughout solveset.) + + Returns EmptySet, if the linear system is inconsistent. + + Raises + ====== + + ValueError + The input is not valid. + The symbols are not given. + + Examples + ======== + + >>> from sympy import Matrix, linsolve, symbols + >>> x, y, z = symbols("x, y, z") + >>> A = Matrix([[1, 2, 3], [4, 5, 6], [7, 8, 10]]) + >>> b = Matrix([3, 6, 9]) + >>> A + Matrix([ + [1, 2, 3], + [4, 5, 6], + [7, 8, 10]]) + >>> b + Matrix([ + [3], + [6], + [9]]) + >>> linsolve((A, b), [x, y, z]) + {(-1, 2, 0)} + + * Parametric Solution: In case the system is underdetermined, the + function will return a parametric solution in terms of the given + symbols. Those that are free will be returned unchanged. e.g. in + the system below, `z` is returned as the solution for variable z; + it can take on any value. + + >>> A = Matrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) + >>> b = Matrix([3, 6, 9]) + >>> linsolve((A, b), x, y, z) + {(z - 1, 2 - 2*z, z)} + + If no symbols are given, internally generated symbols will be used. + The ``tau0`` in the third position indicates (as before) that the third + variable -- whatever it is named -- can take on any value: + + >>> linsolve((A, b)) + {(tau0 - 1, 2 - 2*tau0, tau0)} + + * List of equations as input + + >>> Eqns = [3*x + 2*y - z - 1, 2*x - 2*y + 4*z + 2, - x + y/2 - z] + >>> linsolve(Eqns, x, y, z) + {(1, -2, -2)} + + * Augmented matrix as input + + >>> aug = Matrix([[2, 1, 3, 1], [2, 6, 8, 3], [6, 8, 18, 5]]) + >>> aug + Matrix([ + [2, 1, 3, 1], + [2, 6, 8, 3], + [6, 8, 18, 5]]) + >>> linsolve(aug, x, y, z) + {(3/10, 2/5, 0)} + + * Solve for symbolic coefficients + + >>> a, b, c, d, e, f = symbols('a, b, c, d, e, f') + >>> eqns = [a*x + b*y - c, d*x + e*y - f] + >>> linsolve(eqns, x, y) + {((-b*f + c*e)/(a*e - b*d), (a*f - c*d)/(a*e - b*d))} + + * A degenerate system returns solution as set of given + symbols. + + >>> system = Matrix(([0, 0, 0], [0, 0, 0], [0, 0, 0])) + >>> linsolve(system, x, y) + {(x, y)} + + * For an empty system linsolve returns empty set + + >>> linsolve([], x) + EmptySet + + * An error is raised if any nonlinearity is detected, even + if it could be removed with expansion + + >>> linsolve([x*(1/x - 1)], x) + Traceback (most recent call last): + ... + NonlinearError: nonlinear term: 1/x + + >>> linsolve([x*(y + 1)], x, y) + Traceback (most recent call last): + ... + NonlinearError: nonlinear cross-term: x*(y + 1) + + >>> linsolve([x**2 - 1], x) + Traceback (most recent call last): + ... + NonlinearError: nonlinear term: x**2 + """ + if not system: + return S.EmptySet + + # If second argument is an iterable + if symbols and hasattr(symbols[0], '__iter__'): + symbols = symbols[0] + sym_gen = isinstance(symbols, GeneratorType) + dup_msg = 'duplicate symbols given' + + + b = None # if we don't get b the input was bad + # unpack system + + if hasattr(system, '__iter__'): + + # 1). (A, b) + if len(system) == 2 and isinstance(system[0], MatrixBase): + A, b = system + + # 2). (eq1, eq2, ...) + if not isinstance(system[0], MatrixBase): + if sym_gen or not symbols: + raise ValueError(filldedent(''' + When passing a system of equations, the explicit + symbols for which a solution is being sought must + be given as a sequence, too. + ''')) + if len(set(symbols)) != len(symbols): + raise ValueError(dup_msg) + + # + # Pass to the sparse solver implemented in polys. It is important + # that we do not attempt to convert the equations to a matrix + # because that would be very inefficient for large sparse systems + # of equations. + # + eqs = system + eqs = [sympify(eq) for eq in eqs] + try: + sol = _linsolve(eqs, symbols) + except PolyNonlinearError as exc: + # e.g. cos(x) contains an element of the set of generators + raise NonlinearError(str(exc)) + + if sol is None: + return S.EmptySet + + sol = FiniteSet(Tuple(*(sol.get(sym, sym) for sym in symbols))) + return sol + + elif isinstance(system, MatrixBase) and not ( + symbols and not isinstance(symbols, GeneratorType) and + isinstance(symbols[0], MatrixBase)): + # 3). A augmented with b + A, b = system[:, :-1], system[:, -1:] + + if b is None: + raise ValueError("Invalid arguments") + if sym_gen: + symbols = [next(symbols) for i in range(A.cols)] + symset = set(symbols) + if any(symset & (A.free_symbols | b.free_symbols)): + raise ValueError(filldedent(''' + At least one of the symbols provided + already appears in the system to be solved. + One way to avoid this is to use Dummy symbols in + the generator, e.g. numbered_symbols('%s', cls=Dummy) + ''' % symbols[0].name.rstrip('1234567890'))) + elif len(symset) != len(symbols): + raise ValueError(dup_msg) + + if not symbols: + symbols = [Dummy() for _ in range(A.cols)] + name = _uniquely_named_symbol('tau', (A, b), + compare=lambda i: str(i).rstrip('1234567890')).name + gen = numbered_symbols(name) + else: + gen = None + + # This is just a wrapper for solve_lin_sys + eqs = [] + rows = A.tolist() + for rowi, bi in zip(rows, b): + terms = [elem * sym for elem, sym in zip(rowi, symbols) if elem] + terms.append(-bi) + eqs.append(Add(*terms)) + + eqs, ring = sympy_eqs_to_ring(eqs, symbols) + sol = solve_lin_sys(eqs, ring, _raw=False) + if sol is None: + return S.EmptySet + #sol = {sym:val for sym, val in sol.items() if sym != val} + sol = FiniteSet(Tuple(*(sol.get(sym, sym) for sym in symbols))) + + if gen is not None: + solsym = sol.free_symbols + rep = {sym: next(gen) for sym in symbols if sym in solsym} + sol = sol.subs(rep) + + return sol + + +############################################################################## +# ------------------------------nonlinsolve ---------------------------------# +############################################################################## + + +def _return_conditionset(eqs, symbols): + # return conditionset + eqs = (Eq(lhs, 0) for lhs in eqs) + condition_set = ConditionSet( + Tuple(*symbols), And(*eqs), S.Complexes**len(symbols)) + return condition_set + + +def substitution(system, symbols, result=[{}], known_symbols=[], + exclude=[], all_symbols=None): + r""" + Solves the `system` using substitution method. It is used in + :func:`~.nonlinsolve`. This will be called from :func:`~.nonlinsolve` when any + equation(s) is non polynomial equation. + + Parameters + ========== + + system : list of equations + The target system of equations + symbols : list of symbols to be solved. + The variable(s) for which the system is solved + known_symbols : list of solved symbols + Values are known for these variable(s) + result : An empty list or list of dict + If No symbol values is known then empty list otherwise + symbol as keys and corresponding value in dict. + exclude : Set of expression. + Mostly denominator expression(s) of the equations of the system. + Final solution should not satisfy these expressions. + all_symbols : known_symbols + symbols(unsolved). + + Returns + ======= + + A FiniteSet of ordered tuple of values of `all_symbols` for which the + `system` has solution. Order of values in the tuple is same as symbols + present in the parameter `all_symbols`. If parameter `all_symbols` is None + then same as symbols present in the parameter `symbols`. + + Please note that general FiniteSet is unordered, the solution returned + here is not simply a FiniteSet of solutions, rather it is a FiniteSet of + ordered tuple, i.e. the first & only argument to FiniteSet is a tuple of + solutions, which is ordered, & hence the returned solution is ordered. + + Also note that solution could also have been returned as an ordered tuple, + FiniteSet is just a wrapper `{}` around the tuple. It has no other + significance except for the fact it is just used to maintain a consistent + output format throughout the solveset. + + Raises + ====== + + ValueError + The input is not valid. + The symbols are not given. + AttributeError + The input symbols are not :class:`~.Symbol` type. + + Examples + ======== + + >>> from sympy import symbols, substitution + >>> x, y = symbols('x, y', real=True) + >>> substitution([x + y], [x], [{y: 1}], [y], set([]), [x, y]) + {(-1, 1)} + + * When you want a soln not satisfying $x + 1 = 0$ + + >>> substitution([x + y], [x], [{y: 1}], [y], set([x + 1]), [y, x]) + EmptySet + >>> substitution([x + y], [x], [{y: 1}], [y], set([x - 1]), [y, x]) + {(1, -1)} + >>> substitution([x + y - 1, y - x**2 + 5], [x, y]) + {(-3, 4), (2, -1)} + + * Returns both real and complex solution + + >>> x, y, z = symbols('x, y, z') + >>> from sympy import exp, sin + >>> substitution([exp(x) - sin(y), y**2 - 4], [x, y]) + {(ImageSet(Lambda(_n, I*(2*_n*pi + pi) + log(sin(2))), Integers), -2), + (ImageSet(Lambda(_n, 2*_n*I*pi + log(sin(2))), Integers), 2)} + + >>> eqs = [z**2 + exp(2*x) - sin(y), -3 + exp(-y)] + >>> substitution(eqs, [y, z]) + {(-log(3), -sqrt(-exp(2*x) - sin(log(3)))), + (-log(3), sqrt(-exp(2*x) - sin(log(3)))), + (ImageSet(Lambda(_n, 2*_n*I*pi - log(3)), Integers), + ImageSet(Lambda(_n, -sqrt(-exp(2*x) + sin(2*_n*I*pi - log(3)))), Integers)), + (ImageSet(Lambda(_n, 2*_n*I*pi - log(3)), Integers), + ImageSet(Lambda(_n, sqrt(-exp(2*x) + sin(2*_n*I*pi - log(3)))), Integers))} + + """ + + if not system: + return S.EmptySet + + for i, e in enumerate(system): + if isinstance(e, Eq): + system[i] = e.lhs - e.rhs + + if not symbols: + msg = ('Symbols must be given, for which solution of the ' + 'system is to be found.') + raise ValueError(filldedent(msg)) + + if not is_sequence(symbols): + msg = ('symbols should be given as a sequence, e.g. a list.' + 'Not type %s: %s') + raise TypeError(filldedent(msg % (type(symbols), symbols))) + + if not getattr(symbols[0], 'is_Symbol', False): + msg = ('Iterable of symbols must be given as ' + 'second argument, not type %s: %s') + raise ValueError(filldedent(msg % (type(symbols[0]), symbols[0]))) + + # By default `all_symbols` will be same as `symbols` + if all_symbols is None: + all_symbols = symbols + + old_result = result + # storing complements and intersection for particular symbol + complements = {} + intersections = {} + + # when total_solveset_call equals total_conditionset + # it means that solveset failed to solve all eqs. + total_conditionset = -1 + total_solveset_call = -1 + + def _unsolved_syms(eq, sort=False): + """Returns the unsolved symbol present + in the equation `eq`. + """ + free = eq.free_symbols + unsolved = (free - set(known_symbols)) & set(all_symbols) + if sort: + unsolved = list(unsolved) + unsolved.sort(key=default_sort_key) + return unsolved + + # sort such that equation with the fewest potential symbols is first. + # means eq with less number of variable first in the list. + eqs_in_better_order = list( + ordered(system, lambda _: len(_unsolved_syms(_)))) + + def add_intersection_complement(result, intersection_dict, complement_dict): + # If solveset has returned some intersection/complement + # for any symbol, it will be added in the final solution. + final_result = [] + for res in result: + res_copy = res + for key_res, value_res in res.items(): + intersect_set, complement_set = None, None + for key_sym, value_sym in intersection_dict.items(): + if key_sym == key_res: + intersect_set = value_sym + for key_sym, value_sym in complement_dict.items(): + if key_sym == key_res: + complement_set = value_sym + if intersect_set or complement_set: + new_value = FiniteSet(value_res) + if intersect_set and intersect_set != S.Complexes: + new_value = Intersection(new_value, intersect_set) + if complement_set: + new_value = Complement(new_value, complement_set) + if new_value is S.EmptySet: + res_copy = None + break + elif new_value.is_FiniteSet and len(new_value) == 1: + res_copy[key_res] = set(new_value).pop() + else: + res_copy[key_res] = new_value + + if res_copy is not None: + final_result.append(res_copy) + return final_result + + def _extract_main_soln(sym, sol, soln_imageset): + """Separate the Complements, Intersections, ImageSet lambda expr and + its base_set. This function returns the unmasked sol from different classes + of sets and also returns the appended ImageSet elements in a + soln_imageset dict: `{unmasked element: ImageSet}`. + """ + # if there is union, then need to check + # Complement, Intersection, Imageset. + # Order should not be changed. + if isinstance(sol, ConditionSet): + # extracts any solution in ConditionSet + sol = sol.base_set + + if isinstance(sol, Complement): + # extract solution and complement + complements[sym] = sol.args[1] + sol = sol.args[0] + # complement will be added at the end + # using `add_intersection_complement` method + + # if there is union of Imageset or other in soln. + # no testcase is written for this if block + if isinstance(sol, Union): + sol_args = sol.args + sol = S.EmptySet + # We need in sequence so append finteset elements + # and then imageset or other. + for sol_arg2 in sol_args: + if isinstance(sol_arg2, FiniteSet): + sol += sol_arg2 + else: + # ImageSet, Intersection, complement then + # append them directly + sol += FiniteSet(sol_arg2) + + if isinstance(sol, Intersection): + # Interval/Set will be at 0th index always + if sol.args[0] not in (S.Reals, S.Complexes): + # Sometimes solveset returns soln with intersection + # S.Reals or S.Complexes. We don't consider that + # intersection. + intersections[sym] = sol.args[0] + sol = sol.args[1] + # after intersection and complement Imageset should + # be checked. + if isinstance(sol, ImageSet): + soln_imagest = sol + expr2 = sol.lamda.expr + sol = FiniteSet(expr2) + soln_imageset[expr2] = soln_imagest + + if not isinstance(sol, FiniteSet): + sol = FiniteSet(sol) + return sol, soln_imageset + + def _check_exclude(rnew, imgset_yes): + rnew_ = rnew + if imgset_yes: + # replace all dummy variables (Imageset lambda variables) + # with zero before `checksol`. Considering fundamental soln + # for `checksol`. + rnew_copy = rnew.copy() + dummy_n = imgset_yes[0] + for key_res, value_res in rnew_copy.items(): + rnew_copy[key_res] = value_res.subs(dummy_n, 0) + rnew_ = rnew_copy + # satisfy_exclude == true if it satisfies the expr of `exclude` list. + try: + # something like : `Mod(-log(3), 2*I*pi)` can't be + # simplified right now, so `checksol` returns `TypeError`. + # when this issue is fixed this try block should be + # removed. Mod(-log(3), 2*I*pi) == -log(3) + satisfy_exclude = any( + checksol(d, rnew_) for d in exclude) + except TypeError: + satisfy_exclude = None + return satisfy_exclude + + def _restore_imgset(rnew, original_imageset, newresult): + restore_sym = set(rnew.keys()) & \ + set(original_imageset.keys()) + for key_sym in restore_sym: + img = original_imageset[key_sym] + rnew[key_sym] = img + if rnew not in newresult: + newresult.append(rnew) + + def _append_eq(eq, result, res, delete_soln, n=None): + u = Dummy('u') + if n: + eq = eq.subs(n, 0) + satisfy = eq if eq in (True, False) else checksol(u, u, eq, minimal=True) + if satisfy is False: + delete_soln = True + res = {} + else: + result.append(res) + return result, res, delete_soln + + def _append_new_soln(rnew, sym, sol, imgset_yes, soln_imageset, + original_imageset, newresult, eq=None): + """If `rnew` (A dict ) contains valid soln + append it to `newresult` list. + `imgset_yes` is (base, dummy_var) if there was imageset in previously + calculated result(otherwise empty tuple). `original_imageset` is dict + of imageset expr and imageset from this result. + `soln_imageset` dict of imageset expr and imageset of new soln. + """ + satisfy_exclude = _check_exclude(rnew, imgset_yes) + delete_soln = False + # soln should not satisfy expr present in `exclude` list. + if not satisfy_exclude: + local_n = None + # if it is imageset + if imgset_yes: + local_n = imgset_yes[0] + base = imgset_yes[1] + if sym and sol: + # when `sym` and `sol` is `None` means no new + # soln. In that case we will append rnew directly after + # substituting original imagesets in rnew values if present + # (second last line of this function using _restore_imgset) + dummy_list = list(sol.atoms(Dummy)) + # use one dummy `n` which is in + # previous imageset + local_n_list = [ + local_n for i in range( + 0, len(dummy_list))] + + dummy_zip = zip(dummy_list, local_n_list) + lam = Lambda(local_n, sol.subs(dummy_zip)) + rnew[sym] = ImageSet(lam, base) + if eq is not None: + newresult, rnew, delete_soln = _append_eq( + eq, newresult, rnew, delete_soln, local_n) + elif eq is not None: + newresult, rnew, delete_soln = _append_eq( + eq, newresult, rnew, delete_soln) + elif sol in soln_imageset.keys(): + rnew[sym] = soln_imageset[sol] + # restore original imageset + _restore_imgset(rnew, original_imageset, newresult) + else: + newresult.append(rnew) + elif satisfy_exclude: + delete_soln = True + rnew = {} + _restore_imgset(rnew, original_imageset, newresult) + return newresult, delete_soln + + def _new_order_result(result, eq): + # separate first, second priority. `res` that makes `eq` value equals + # to zero, should be used first then other result(second priority). + # If it is not done then we may miss some soln. + first_priority = [] + second_priority = [] + for res in result: + if not any(isinstance(val, ImageSet) for val in res.values()): + if eq.subs(res) == 0: + first_priority.append(res) + else: + second_priority.append(res) + if first_priority or second_priority: + return first_priority + second_priority + return result + + def _solve_using_known_values(result, solver): + """Solves the system using already known solution + (result contains the dict ). + solver is :func:`~.solveset_complex` or :func:`~.solveset_real`. + """ + # stores imageset . + soln_imageset = {} + total_solvest_call = 0 + total_conditionst = 0 + + # sort equations so the one with the fewest potential + # symbols appears first + for index, eq in enumerate(eqs_in_better_order): + newresult = [] + # if imageset, expr is used to solve for other symbol + imgset_yes = False + for res in result: + original_imageset = {} + got_symbol = set() # symbols solved in one iteration + # find the imageset and use its expr. + for k, v in res.items(): + if isinstance(v, ImageSet): + res[k] = v.lamda.expr + original_imageset[k] = v + dummy_n = v.lamda.expr.atoms(Dummy).pop() + (base,) = v.base_sets + imgset_yes = (dummy_n, base) + assert not isinstance(v, FiniteSet) # if so, internal error + # update eq with everything that is known so far + eq2 = eq.subs(res).expand() + if imgset_yes and not eq2.has(imgset_yes[0]): + # The substituted equation simplified in such a way that + # it's no longer necessary to encapsulate a potential new + # solution in an ImageSet. (E.g. at the previous step some + # {n*2*pi} was found as partial solution for one of the + # unknowns, but its main solution expression n*2*pi has now + # been substituted in a trigonometric function.) + imgset_yes = False + + unsolved_syms = _unsolved_syms(eq2, sort=True) + if not unsolved_syms: + if res: + newresult, delete_res = _append_new_soln( + res, None, None, imgset_yes, soln_imageset, + original_imageset, newresult, eq2) + if delete_res: + # `delete_res` is true, means substituting `res` in + # eq2 doesn't return `zero` or deleting the `res` + # (a soln) since it satisfies expr of `exclude` + # list. + result.remove(res) + continue # skip as it's independent of desired symbols + depen1, depen2 = eq2.as_independent(*unsolved_syms) + if (depen1.has(Abs) or depen2.has(Abs)) and solver == solveset_complex: + # Absolute values cannot be inverted in the + # complex domain + continue + soln_imageset = {} + for sym in unsolved_syms: + not_solvable = False + try: + soln = solver(eq2, sym) + total_solvest_call += 1 + soln_new = S.EmptySet + if isinstance(soln, Complement): + # separate solution and complement + complements[sym] = soln.args[1] + soln = soln.args[0] + # complement will be added at the end + if isinstance(soln, Intersection): + # Interval will be at 0th index always + if soln.args[0] != Interval(-oo, oo): + # sometimes solveset returns soln + # with intersection S.Reals, to confirm that + # soln is in domain=S.Reals + intersections[sym] = soln.args[0] + soln_new += soln.args[1] + soln = soln_new if soln_new else soln + if index > 0 and solver == solveset_real: + # one symbol's real soln, another symbol may have + # corresponding complex soln. + if not isinstance(soln, (ImageSet, ConditionSet)): + soln += solveset_complex(eq2, sym) # might give ValueError with Abs + except (NotImplementedError, ValueError): + # If solveset is not able to solve equation `eq2`. Next + # time we may get soln using next equation `eq2` + continue + if isinstance(soln, ConditionSet): + if soln.base_set in (S.Reals, S.Complexes): + soln = S.EmptySet + # don't do `continue` we may get soln + # in terms of other symbol(s) + not_solvable = True + total_conditionst += 1 + else: + soln = soln.base_set + + if soln is not S.EmptySet: + soln, soln_imageset = _extract_main_soln( + sym, soln, soln_imageset) + + for sol in soln: + # sol is not a `Union` since we checked it + # before this loop + sol, soln_imageset = _extract_main_soln( + sym, sol, soln_imageset) + sol = set(sol).pop() # XXX what if there are more solutions? + free = sol.free_symbols + if got_symbol and any( + ss in free for ss in got_symbol + ): + # sol depends on previously solved symbols + # then continue + continue + rnew = res.copy() + # put each solution in res and append the new result + # in the new result list (solution for symbol `s`) + # along with old results. + for k, v in res.items(): + if isinstance(v, Expr) and isinstance(sol, Expr): + # if any unsolved symbol is present + # Then subs known value + rnew[k] = v.subs(sym, sol) + # and add this new solution + if sol in soln_imageset.keys(): + # replace all lambda variables with 0. + imgst = soln_imageset[sol] + rnew[sym] = imgst.lamda( + *[0 for i in range(0, len( + imgst.lamda.variables))]) + else: + rnew[sym] = sol + newresult, delete_res = _append_new_soln( + rnew, sym, sol, imgset_yes, soln_imageset, + original_imageset, newresult) + if delete_res: + # deleting the `res` (a soln) since it satisfies + # eq of `exclude` list + result.remove(res) + # solution got for sym + if not not_solvable: + got_symbol.add(sym) + # next time use this new soln + if newresult: + result = newresult + return result, total_solvest_call, total_conditionst + + new_result_real, solve_call1, cnd_call1 = _solve_using_known_values( + old_result, solveset_real) + new_result_complex, solve_call2, cnd_call2 = _solve_using_known_values( + old_result, solveset_complex) + + # If total_solveset_call is equal to total_conditionset + # then solveset failed to solve all of the equations. + # In this case we return a ConditionSet here. + total_conditionset += (cnd_call1 + cnd_call2) + total_solveset_call += (solve_call1 + solve_call2) + + if total_conditionset == total_solveset_call and total_solveset_call != -1: + return _return_conditionset(eqs_in_better_order, all_symbols) + + # don't keep duplicate solutions + filtered_complex = [] + for i in list(new_result_complex): + for j in list(new_result_real): + if i.keys() != j.keys(): + continue + if all(a.dummy_eq(b) for a, b in zip(i.values(), j.values()) \ + if not (isinstance(a, int) and isinstance(b, int))): + break + else: + filtered_complex.append(i) + # overall result + result = new_result_real + filtered_complex + + result_all_variables = [] + result_infinite = [] + for res in result: + if not res: + # means {None : None} + continue + # If length < len(all_symbols) means infinite soln. + # Some or all the soln is dependent on 1 symbol. + # eg. {x: y+2} then final soln {x: y+2, y: y} + if len(res) < len(all_symbols): + solved_symbols = res.keys() + unsolved = list(filter( + lambda x: x not in solved_symbols, all_symbols)) + for unsolved_sym in unsolved: + res[unsolved_sym] = unsolved_sym + result_infinite.append(res) + if res not in result_all_variables: + result_all_variables.append(res) + + if result_infinite: + # we have general soln + # eg : [{x: -1, y : 1}, {x : -y, y: y}] then + # return [{x : -y, y : y}] + result_all_variables = result_infinite + if intersections or complements: + result_all_variables = add_intersection_complement( + result_all_variables, intersections, complements) + + # convert to ordered tuple + result = S.EmptySet + for r in result_all_variables: + temp = [r[symb] for symb in all_symbols] + result += FiniteSet(tuple(temp)) + return result + + +def _solveset_work(system, symbols): + soln = solveset(system[0], symbols[0]) + if isinstance(soln, FiniteSet): + _soln = FiniteSet(*[(s,) for s in soln]) + return _soln + else: + return FiniteSet(tuple(FiniteSet(soln))) + + +def _handle_positive_dimensional(polys, symbols, denominators): + from sympy.polys.polytools import groebner + # substitution method where new system is groebner basis of the system + _symbols = list(symbols) + _symbols.sort(key=default_sort_key) + basis = groebner(polys, _symbols, polys=True) + new_system = [] + for poly_eq in basis: + new_system.append(poly_eq.as_expr()) + result = [{}] + result = substitution( + new_system, symbols, result, [], + denominators) + return result + + +def _handle_zero_dimensional(polys, symbols, system): + # solve 0 dimensional poly system using `solve_poly_system` + result = solve_poly_system(polys, *symbols) + # May be some extra soln is added because + # we used `unrad` in `_separate_poly_nonpoly`, so + # need to check and remove if it is not a soln. + result_update = S.EmptySet + for res in result: + dict_sym_value = dict(list(zip(symbols, res))) + if all(checksol(eq, dict_sym_value) for eq in system): + result_update += FiniteSet(res) + return result_update + + +def _separate_poly_nonpoly(system, symbols): + polys = [] + polys_expr = [] + nonpolys = [] + # unrad_changed stores a list of expressions containing + # radicals that were processed using unrad + # this is useful if solutions need to be checked later. + unrad_changed = [] + denominators = set() + poly = None + for eq in system: + # Store denom expressions that contain symbols + denominators.update(_simple_dens(eq, symbols)) + # Convert equality to expression + if isinstance(eq, Eq): + eq = eq.lhs - eq.rhs + # try to remove sqrt and rational power + without_radicals = unrad(simplify(eq), *symbols) + if without_radicals: + unrad_changed.append(eq) + eq_unrad, cov = without_radicals + if not cov: + eq = eq_unrad + if isinstance(eq, Expr): + eq = eq.as_numer_denom()[0] + poly = eq.as_poly(*symbols, extension=True) + elif simplify(eq).is_number: + continue + if poly is not None: + polys.append(poly) + polys_expr.append(poly.as_expr()) + else: + nonpolys.append(eq) + return polys, polys_expr, nonpolys, denominators, unrad_changed + + +def _handle_poly(polys, symbols): + # _handle_poly(polys, symbols) -> (poly_sol, poly_eqs) + # + # We will return possible solution information to nonlinsolve as well as a + # new system of polynomial equations to be solved if we cannot solve + # everything directly here. The new system of polynomial equations will be + # a lex-order Groebner basis for the original system. The lex basis + # hopefully separate some of the variables and equations and give something + # easier for substitution to work with. + + # The format for representing solution sets in nonlinsolve and substitution + # is a list of dicts. These are the special cases: + no_information = [{}] # No equations solved yet + no_solutions = [] # The system is inconsistent and has no solutions. + + # If there is no need to attempt further solution of these equations then + # we return no equations: + no_equations = [] + + inexact = any(not p.domain.is_Exact for p in polys) + if inexact: + # The use of Groebner over RR is likely to result incorrectly in an + # inconsistent Groebner basis. So, convert any float coefficients to + # Rational before computing the Groebner basis. + polys = [poly(nsimplify(p, rational=True)) for p in polys] + + # Compute a Groebner basis in grevlex order wrt the ordering given. We will + # try to convert this to lex order later. Usually it seems to be more + # efficient to compute a lex order basis by computing a grevlex basis and + # converting to lex with fglm. + basis = groebner(polys, symbols, order='grevlex', polys=False) + + # + # No solutions (inconsistent equations)? + # + if 1 in basis: + + # No solutions: + poly_sol = no_solutions + poly_eqs = no_equations + + # + # Finite number of solutions (zero-dimensional case) + # + elif basis.is_zero_dimensional: + + # Convert Groebner basis to lex ordering + basis = basis.fglm('lex') + + # Convert polynomial coefficients back to float before calling + # solve_poly_system + if inexact: + basis = [nfloat(p) for p in basis] + + # Solve the zero-dimensional case using solve_poly_system if possible. + # If some polynomials have factors that cannot be solved in radicals + # then this will fail. Using solve_poly_system(..., strict=True) + # ensures that we either get a complete solution set in radicals or + # UnsolvableFactorError will be raised. + try: + result = solve_poly_system(basis, *symbols, strict=True) + except UnsolvableFactorError: + # Failure... not fully solvable in radicals. Return the lex-order + # basis for substitution to handle. + poly_sol = no_information + poly_eqs = list(basis) + else: + # Success! We have a finite solution set and solve_poly_system has + # succeeded in finding all solutions. Return the solutions and also + # an empty list of remaining equations to be solved. + poly_sol = [dict(zip(symbols, res)) for res in result] + poly_eqs = no_equations + + # + # Infinite families of solutions (positive-dimensional case) + # + else: + # In this case the grevlex basis cannot be converted to lex using the + # fglm method and also solve_poly_system cannot solve the equations. We + # would like to return a lex basis but since we can't use fglm we + # compute the lex basis directly here. The time required to recompute + # the basis is generally significantly less than the time required by + # substitution to solve the new system. + poly_sol = no_information + poly_eqs = list(groebner(polys, symbols, order='lex', polys=False)) + + if inexact: + poly_eqs = [nfloat(p) for p in poly_eqs] + + return poly_sol, poly_eqs + + +def nonlinsolve(system, *symbols): + r""" + Solve system of $N$ nonlinear equations with $M$ variables, which means both + under and overdetermined systems are supported. Positive dimensional + system is also supported (A system with infinitely many solutions is said + to be positive-dimensional). In a positive dimensional system the solution will + be dependent on at least one symbol. Returns both real solution + and complex solution (if they exist). + + Parameters + ========== + + system : list of equations + The target system of equations + symbols : list of Symbols + symbols should be given as a sequence eg. list + + Returns + ======= + + A :class:`~.FiniteSet` of ordered tuple of values of `symbols` for which the `system` + has solution. Order of values in the tuple is same as symbols present in + the parameter `symbols`. + + Please note that general :class:`~.FiniteSet` is unordered, the solution + returned here is not simply a :class:`~.FiniteSet` of solutions, rather it + is a :class:`~.FiniteSet` of ordered tuple, i.e. the first and only + argument to :class:`~.FiniteSet` is a tuple of solutions, which is + ordered, and, hence ,the returned solution is ordered. + + Also note that solution could also have been returned as an ordered tuple, + FiniteSet is just a wrapper ``{}`` around the tuple. It has no other + significance except for the fact it is just used to maintain a consistent + output format throughout the solveset. + + For the given set of equations, the respective input types + are given below: + + .. math:: xy - 1 = 0 + .. math:: 4x^2 + y^2 - 5 = 0 + + :: + + system = [x*y - 1, 4*x**2 + y**2 - 5] + symbols = [x, y] + + Raises + ====== + + ValueError + The input is not valid. + The symbols are not given. + AttributeError + The input symbols are not `Symbol` type. + + Examples + ======== + + >>> from sympy import symbols, nonlinsolve + >>> x, y, z = symbols('x, y, z', real=True) + >>> nonlinsolve([x*y - 1, 4*x**2 + y**2 - 5], [x, y]) + {(-1, -1), (-1/2, -2), (1/2, 2), (1, 1)} + + 1. Positive dimensional system and complements: + + >>> from sympy import pprint + >>> from sympy.polys.polytools import is_zero_dimensional + >>> a, b, c, d = symbols('a, b, c, d', extended_real=True) + >>> eq1 = a + b + c + d + >>> eq2 = a*b + b*c + c*d + d*a + >>> eq3 = a*b*c + b*c*d + c*d*a + d*a*b + >>> eq4 = a*b*c*d - 1 + >>> system = [eq1, eq2, eq3, eq4] + >>> is_zero_dimensional(system) + False + >>> pprint(nonlinsolve(system, [a, b, c, d]), use_unicode=False) + -1 1 1 -1 + {(---, -d, -, {d} \ {0}), (-, -d, ---, {d} \ {0})} + d d d d + >>> nonlinsolve([(x+y)**2 - 4, x + y - 2], [x, y]) + {(2 - y, y)} + + 2. If some of the equations are non-polynomial then `nonlinsolve` + will call the ``substitution`` function and return real and complex solutions, + if present. + + >>> from sympy import exp, sin + >>> nonlinsolve([exp(x) - sin(y), y**2 - 4], [x, y]) + {(ImageSet(Lambda(_n, I*(2*_n*pi + pi) + log(sin(2))), Integers), -2), + (ImageSet(Lambda(_n, 2*_n*I*pi + log(sin(2))), Integers), 2)} + + 3. If system is non-linear polynomial and zero-dimensional then it + returns both solution (real and complex solutions, if present) using + :func:`~.solve_poly_system`: + + >>> from sympy import sqrt + >>> nonlinsolve([x**2 - 2*y**2 -2, x*y - 2], [x, y]) + {(-2, -1), (2, 1), (-sqrt(2)*I, sqrt(2)*I), (sqrt(2)*I, -sqrt(2)*I)} + + 4. ``nonlinsolve`` can solve some linear (zero or positive dimensional) + system (because it uses the :func:`sympy.polys.polytools.groebner` function to get the + groebner basis and then uses the ``substitution`` function basis as the + new `system`). But it is not recommended to solve linear system using + ``nonlinsolve``, because :func:`~.linsolve` is better for general linear systems. + + >>> nonlinsolve([x + 2*y -z - 3, x - y - 4*z + 9, y + z - 4], [x, y, z]) + {(3*z - 5, 4 - z, z)} + + 5. System having polynomial equations and only real solution is + solved using :func:`~.solve_poly_system`: + + >>> e1 = sqrt(x**2 + y**2) - 10 + >>> e2 = sqrt(y**2 + (-x + 10)**2) - 3 + >>> nonlinsolve((e1, e2), (x, y)) + {(191/20, -3*sqrt(391)/20), (191/20, 3*sqrt(391)/20)} + >>> nonlinsolve([x**2 + 2/y - 2, x + y - 3], [x, y]) + {(1, 2), (1 - sqrt(5), 2 + sqrt(5)), (1 + sqrt(5), 2 - sqrt(5))} + >>> nonlinsolve([x**2 + 2/y - 2, x + y - 3], [y, x]) + {(2, 1), (2 - sqrt(5), 1 + sqrt(5)), (2 + sqrt(5), 1 - sqrt(5))} + + 6. It is better to use symbols instead of trigonometric functions or + :class:`~.Function`. For example, replace $\sin(x)$ with a symbol, replace + $f(x)$ with a symbol and so on. Get a solution from ``nonlinsolve`` and then + use :func:`~.solveset` to get the value of $x$. + + How nonlinsolve is better than old solver ``_solve_system`` : + ============================================================= + + 1. A positive dimensional system solver: nonlinsolve can return + solution for positive dimensional system. It finds the + Groebner Basis of the positive dimensional system(calling it as + basis) then we can start solving equation(having least number of + variable first in the basis) using solveset and substituting that + solved solutions into other equation(of basis) to get solution in + terms of minimum variables. Here the important thing is how we + are substituting the known values and in which equations. + + 2. Real and complex solutions: nonlinsolve returns both real + and complex solution. If all the equations in the system are polynomial + then using :func:`~.solve_poly_system` both real and complex solution is returned. + If all the equations in the system are not polynomial equation then goes to + ``substitution`` method with this polynomial and non polynomial equation(s), + to solve for unsolved variables. Here to solve for particular variable + solveset_real and solveset_complex is used. For both real and complex + solution ``_solve_using_known_values`` is used inside ``substitution`` + (``substitution`` will be called when any non-polynomial equation is present). + If a solution is valid its general solution is added to the final result. + + 3. :class:`~.Complement` and :class:`~.Intersection` will be added: + nonlinsolve maintains dict for complements and intersections. If solveset + find complements or/and intersections with any interval or set during the + execution of ``substitution`` function, then complement or/and + intersection for that variable is added before returning final solution. + + """ + if not system: + return S.EmptySet + + if not symbols: + msg = ('Symbols must be given, for which solution of the ' + 'system is to be found.') + raise ValueError(filldedent(msg)) + + if hasattr(symbols[0], '__iter__'): + symbols = symbols[0] + + if not is_sequence(symbols) or not symbols: + msg = ('Symbols must be given, for which solution of the ' + 'system is to be found.') + raise IndexError(filldedent(msg)) + + symbols = list(map(_sympify, symbols)) + system, symbols, swap = recast_to_symbols(system, symbols) + if swap: + soln = nonlinsolve(system, symbols) + return FiniteSet(*[tuple(i.xreplace(swap) for i in s) for s in soln]) + + if len(system) == 1 and len(symbols) == 1: + return _solveset_work(system, symbols) + + # main code of def nonlinsolve() starts from here + + polys, polys_expr, nonpolys, denominators, unrad_changed = \ + _separate_poly_nonpoly(system, symbols) + + poly_eqs = [] + poly_sol = [{}] + + if polys: + poly_sol, poly_eqs = _handle_poly(polys, symbols) + if poly_sol and poly_sol[0]: + poly_syms = set().union(*(eq.free_symbols for eq in polys)) + unrad_syms = set().union(*(eq.free_symbols for eq in unrad_changed)) + if unrad_syms == poly_syms and unrad_changed: + # if all the symbols have been solved by _handle_poly + # and unrad has been used then check solutions + poly_sol = [sol for sol in poly_sol if checksol(unrad_changed, sol)] + + # Collect together the unsolved polynomials with the non-polynomial + # equations. + remaining = poly_eqs + nonpolys + + # to_tuple converts a solution dictionary to a tuple containing the + # value for each symbol + to_tuple = lambda sol: tuple(sol[s] for s in symbols) + + if not remaining: + # If there is nothing left to solve then return the solution from + # solve_poly_system directly. + return FiniteSet(*map(to_tuple, poly_sol)) + else: + # Here we handle: + # + # 1. The Groebner basis if solve_poly_system failed. + # 2. The Groebner basis in the positive-dimensional case. + # 3. Any non-polynomial equations + # + # If solve_poly_system did succeed then we pass those solutions in as + # preliminary results. + subs_res = substitution(remaining, symbols, result=poly_sol, exclude=denominators) + + if not isinstance(subs_res, FiniteSet): + return subs_res + + # check solutions produced by substitution. Currently, checking is done for + # only those solutions which have non-Set variable values. + if unrad_changed: + result = [dict(zip(symbols, sol)) for sol in subs_res.args] + correct_sols = [sol for sol in result if any(isinstance(v, Set) for v in sol) + or checksol(unrad_changed, sol) != False] + return FiniteSet(*map(to_tuple, correct_sols)) + else: + return subs_res diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_constantsimp.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_constantsimp.py new file mode 100644 index 0000000000000000000000000000000000000000..efb966a4c8c2f93558d05e7c330f06530e69180c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_constantsimp.py @@ -0,0 +1,179 @@ +""" +If the arbitrary constant class from issue 4435 is ever implemented, this +should serve as a set of test cases. +""" + +from sympy.core.function import Function +from sympy.core.numbers import I +from sympy.core.power import Pow +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import Symbol +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.hyperbolic import (cosh, sinh) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import (acos, cos, sin) +from sympy.integrals.integrals import Integral +from sympy.solvers.ode.ode import constantsimp, constant_renumber +from sympy.testing.pytest import XFAIL + + +x = Symbol('x') +y = Symbol('y') +z = Symbol('z') +u2 = Symbol('u2') +_a = Symbol('_a') +C1 = Symbol('C1') +C2 = Symbol('C2') +C3 = Symbol('C3') +f = Function('f') + + +def test_constant_mul(): + # We want C1 (Constant) below to absorb the y's, but not the x's + assert constant_renumber(constantsimp(y*C1, [C1])) == C1*y + assert constant_renumber(constantsimp(C1*y, [C1])) == C1*y + assert constant_renumber(constantsimp(x*C1, [C1])) == x*C1 + assert constant_renumber(constantsimp(C1*x, [C1])) == x*C1 + assert constant_renumber(constantsimp(2*C1, [C1])) == C1 + assert constant_renumber(constantsimp(C1*2, [C1])) == C1 + assert constant_renumber(constantsimp(y*C1*x, [C1, y])) == C1*x + assert constant_renumber(constantsimp(x*y*C1, [C1, y])) == x*C1 + assert constant_renumber(constantsimp(y*x*C1, [C1, y])) == x*C1 + assert constant_renumber(constantsimp(C1*x*y, [C1, y])) == C1*x + assert constant_renumber(constantsimp(x*C1*y, [C1, y])) == x*C1 + assert constant_renumber(constantsimp(C1*y*(y + 1), [C1])) == C1*y*(y+1) + assert constant_renumber(constantsimp(y*C1*(y + 1), [C1])) == C1*y*(y+1) + assert constant_renumber(constantsimp(x*(y*C1), [C1])) == x*y*C1 + assert constant_renumber(constantsimp(x*(C1*y), [C1])) == x*y*C1 + assert constant_renumber(constantsimp(C1*(x*y), [C1, y])) == C1*x + assert constant_renumber(constantsimp((x*y)*C1, [C1, y])) == x*C1 + assert constant_renumber(constantsimp((y*x)*C1, [C1, y])) == x*C1 + assert constant_renumber(constantsimp(y*(y + 1)*C1, [C1, y])) == C1 + assert constant_renumber(constantsimp((C1*x)*y, [C1, y])) == C1*x + assert constant_renumber(constantsimp(y*(x*C1), [C1, y])) == x*C1 + assert constant_renumber(constantsimp((x*C1)*y, [C1, y])) == x*C1 + assert constant_renumber(constantsimp(C1*x*y*x*y*2, [C1, y])) == C1*x**2 + assert constant_renumber(constantsimp(C1*x*y*z, [C1, y, z])) == C1*x + assert constant_renumber(constantsimp(C1*x*y**2*sin(z), [C1, y, z])) == C1*x + assert constant_renumber(constantsimp(C1*C1, [C1])) == C1 + assert constant_renumber(constantsimp(C1*C2, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C2*C2, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C1*C1*C2, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C1*x*2**x, [C1])) == C1*x*2**x + +def test_constant_add(): + assert constant_renumber(constantsimp(C1 + C1, [C1])) == C1 + assert constant_renumber(constantsimp(C1 + 2, [C1])) == C1 + assert constant_renumber(constantsimp(2 + C1, [C1])) == C1 + assert constant_renumber(constantsimp(C1 + y, [C1, y])) == C1 + assert constant_renumber(constantsimp(C1 + x, [C1])) == C1 + x + assert constant_renumber(constantsimp(C1 + C1, [C1])) == C1 + assert constant_renumber(constantsimp(C1 + C2, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C2 + C1, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C1 + C2 + C1, [C1, C2])) == C1 + + +def test_constant_power_as_base(): + assert constant_renumber(constantsimp(C1**C1, [C1])) == C1 + assert constant_renumber(constantsimp(Pow(C1, C1), [C1])) == C1 + assert constant_renumber(constantsimp(C1**C1, [C1])) == C1 + assert constant_renumber(constantsimp(C1**C2, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C2**C1, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C2**C2, [C1, C2])) == C1 + assert constant_renumber(constantsimp(C1**y, [C1, y])) == C1 + assert constant_renumber(constantsimp(C1**x, [C1])) == C1**x + assert constant_renumber(constantsimp(C1**2, [C1])) == C1 + assert constant_renumber( + constantsimp(C1**(x*y), [C1])) == C1**(x*y) + + +def test_constant_power_as_exp(): + assert constant_renumber(constantsimp(x**C1, [C1])) == x**C1 + assert constant_renumber(constantsimp(y**C1, [C1, y])) == C1 + assert constant_renumber(constantsimp(x**y**C1, [C1, y])) == x**C1 + assert constant_renumber( + constantsimp((x**y)**C1, [C1])) == (x**y)**C1 + assert constant_renumber( + constantsimp(x**(y**C1), [C1, y])) == x**C1 + assert constant_renumber(constantsimp(x**C1**y, [C1, y])) == x**C1 + assert constant_renumber( + constantsimp(x**(C1**y), [C1, y])) == x**C1 + assert constant_renumber( + constantsimp((x**C1)**y, [C1])) == (x**C1)**y + assert constant_renumber(constantsimp(2**C1, [C1])) == C1 + assert constant_renumber(constantsimp(S(2)**C1, [C1])) == C1 + assert constant_renumber(constantsimp(exp(C1), [C1])) == C1 + assert constant_renumber( + constantsimp(exp(C1 + x), [C1])) == C1*exp(x) + assert constant_renumber(constantsimp(Pow(2, C1), [C1])) == C1 + + +def test_constant_function(): + assert constant_renumber(constantsimp(sin(C1), [C1])) == C1 + assert constant_renumber(constantsimp(f(C1), [C1])) == C1 + assert constant_renumber(constantsimp(f(C1, C1), [C1])) == C1 + assert constant_renumber(constantsimp(f(C1, C2), [C1, C2])) == C1 + assert constant_renumber(constantsimp(f(C2, C1), [C1, C2])) == C1 + assert constant_renumber(constantsimp(f(C2, C2), [C1, C2])) == C1 + assert constant_renumber( + constantsimp(f(C1, x), [C1])) == f(C1, x) + assert constant_renumber(constantsimp(f(C1, y), [C1, y])) == C1 + assert constant_renumber(constantsimp(f(y, C1), [C1, y])) == C1 + assert constant_renumber(constantsimp(f(C1, y, C2), [C1, C2, y])) == C1 + + +def test_constant_function_multiple(): + # The rules to not renumber in this case would be too complicated, and + # dsolve is not likely to ever encounter anything remotely like this. + assert constant_renumber( + constantsimp(f(C1, C1, x), [C1])) == f(C1, C1, x) + + +def test_constant_multiple(): + assert constant_renumber(constantsimp(C1*2 + 2, [C1])) == C1 + assert constant_renumber(constantsimp(x*2/C1, [C1])) == C1*x + assert constant_renumber(constantsimp(C1**2*2 + 2, [C1])) == C1 + assert constant_renumber( + constantsimp(sin(2*C1) + x + sqrt(2), [C1])) == C1 + x + assert constant_renumber(constantsimp(2*C1 + C2, [C1, C2])) == C1 + +def test_constant_repeated(): + assert C1 + C1*x == constant_renumber( C1 + C1*x) + +def test_ode_solutions(): + # only a few examples here, the rest will be tested in the actual dsolve tests + assert constant_renumber(constantsimp(C1*exp(2*x) + exp(x)*(C2 + C3), [C1, C2, C3])) == \ + constant_renumber(C1*exp(x) + C2*exp(2*x)) + assert constant_renumber( + constantsimp(Eq(f(x), I*C1*sinh(x/3) + C2*cosh(x/3)), [C1, C2]) + ) == constant_renumber(Eq(f(x), C1*sinh(x/3) + C2*cosh(x/3))) + assert constant_renumber(constantsimp(Eq(f(x), acos((-C1)/cos(x))), [C1])) == \ + Eq(f(x), acos(C1/cos(x))) + assert constant_renumber( + constantsimp(Eq(log(f(x)/C1) + 2*exp(x/f(x)), 0), [C1]) + ) == Eq(log(C1*f(x)) + 2*exp(x/f(x)), 0) + assert constant_renumber(constantsimp(Eq(log(x*sqrt(2)*sqrt(1/x)*sqrt(f(x)) + /C1) + x**2/(2*f(x)**2), 0), [C1])) == \ + Eq(log(C1*sqrt(x)*sqrt(f(x))) + x**2/(2*f(x)**2), 0) + assert constant_renumber(constantsimp(Eq(-exp(-f(x)/x)*sin(f(x)/x)/2 + log(x/C1) - + cos(f(x)/x)*exp(-f(x)/x)/2, 0), [C1])) == \ + Eq(-exp(-f(x)/x)*sin(f(x)/x)/2 + log(C1*x) - cos(f(x)/x)* + exp(-f(x)/x)/2, 0) + assert constant_renumber(constantsimp(Eq(-Integral(-1/(sqrt(1 - u2**2)*u2), + (u2, _a, x/f(x))) + log(f(x)/C1), 0), [C1])) == \ + Eq(-Integral(-1/(u2*sqrt(1 - u2**2)), (u2, _a, x/f(x))) + + log(C1*f(x)), 0) + assert [constantsimp(i, [C1]) for i in [Eq(f(x), sqrt(-C1*x + x**2)), Eq(f(x), -sqrt(-C1*x + x**2))]] == \ + [Eq(f(x), sqrt(x*(C1 + x))), Eq(f(x), -sqrt(x*(C1 + x)))] + + +@XFAIL +def test_nonlocal_simplification(): + assert constantsimp(C1 + C2+x*C2, [C1, C2]) == C1 + C2*x + + +def test_constant_Eq(): + # C1 on the rhs is well-tested, but the lhs is only tested here + assert constantsimp(Eq(C1, 3 + f(x)*x), [C1]) == Eq(x*f(x), C1) + assert constantsimp(Eq(C1, 3 * f(x)*x), [C1]) == Eq(f(x)*x, C1) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_decompogen.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_decompogen.py new file mode 100644 index 0000000000000000000000000000000000000000..1ba03f4b42558231b626b6ed169f8b0a81a72bf9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_decompogen.py @@ -0,0 +1,59 @@ +from sympy.solvers.decompogen import decompogen, compogen +from sympy.core.symbol import symbols +from sympy.functions.elementary.complexes import Abs +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt, Max +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.testing.pytest import XFAIL, raises + +x, y = symbols('x y') + + +def test_decompogen(): + assert decompogen(sin(cos(x)), x) == [sin(x), cos(x)] + assert decompogen(sin(x)**2 + sin(x) + 1, x) == [x**2 + x + 1, sin(x)] + assert decompogen(sqrt(6*x**2 - 5), x) == [sqrt(x), 6*x**2 - 5] + assert decompogen(sin(sqrt(cos(x**2 + 1))), x) == [sin(x), sqrt(x), cos(x), x**2 + 1] + assert decompogen(Abs(cos(x)**2 + 3*cos(x) - 4), x) == [Abs(x), x**2 + 3*x - 4, cos(x)] + assert decompogen(sin(x)**2 + sin(x) - sqrt(3)/2, x) == [x**2 + x - sqrt(3)/2, sin(x)] + assert decompogen(Abs(cos(y)**2 + 3*cos(x) - 4), x) == [Abs(x), 3*x + cos(y)**2 - 4, cos(x)] + assert decompogen(x, y) == [x] + assert decompogen(1, x) == [1] + assert decompogen(Max(3, x), x) == [Max(3, x)] + raises(TypeError, lambda: decompogen(x < 5, x)) + u = 2*x + 3 + assert decompogen(Max(sqrt(u),(u)**2), x) == [Max(sqrt(x), x**2), u] + assert decompogen(Max(u, u**2, y), x) == [Max(x, x**2, y), u] + assert decompogen(Max(sin(x), u), x) == [Max(2*x + 3, sin(x))] + + +def test_decompogen_poly(): + assert decompogen(x**4 + 2*x**2 + 1, x) == [x**2 + 2*x + 1, x**2] + assert decompogen(x**4 + 2*x**3 - x - 1, x) == [x**2 - x - 1, x**2 + x] + + +@XFAIL +def test_decompogen_fails(): + A = lambda x: x**2 + 2*x + 3 + B = lambda x: 4*x**2 + 5*x + 6 + assert decompogen(A(x*exp(x)), x) == [x**2 + 2*x + 3, x*exp(x)] + assert decompogen(A(B(x)), x) == [x**2 + 2*x + 3, 4*x**2 + 5*x + 6] + assert decompogen(A(1/x + 1/x**2), x) == [x**2 + 2*x + 3, 1/x + 1/x**2] + assert decompogen(A(1/x + 2/(x + 1)), x) == [x**2 + 2*x + 3, 1/x + 2/(x + 1)] + + +def test_compogen(): + assert compogen([sin(x), cos(x)], x) == sin(cos(x)) + assert compogen([x**2 + x + 1, sin(x)], x) == sin(x)**2 + sin(x) + 1 + assert compogen([sqrt(x), 6*x**2 - 5], x) == sqrt(6*x**2 - 5) + assert compogen([sin(x), sqrt(x), cos(x), x**2 + 1], x) == sin(sqrt( + cos(x**2 + 1))) + assert compogen([Abs(x), x**2 + 3*x - 4, cos(x)], x) == Abs(cos(x)**2 + + 3*cos(x) - 4) + assert compogen([x**2 + x - sqrt(3)/2, sin(x)], x) == (sin(x)**2 + sin(x) - + sqrt(3)/2) + assert compogen([Abs(x), 3*x + cos(y)**2 - 4, cos(x)], x) == \ + Abs(3*cos(x) + cos(y)**2 - 4) + assert compogen([x**2 + 2*x + 1, x**2], x) == x**4 + 2*x**2 + 1 + # the result is in unsimplified form + assert compogen([x**2 - x - 1, x**2 + x], x) == -x**2 - x + (x**2 + x)**2 - 1 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_inequalities.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_inequalities.py new file mode 100644 index 0000000000000000000000000000000000000000..6ce6f4520b52d8714102c95457c90d44543c685c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_inequalities.py @@ -0,0 +1,500 @@ +"""Tests for tools for solving inequalities and systems of inequalities. """ + +from sympy.concrete.summations import Sum +from sympy.core.function import Function +from sympy.core.numbers import I, Rational, oo, pi +from sympy.core.relational import Eq, Ge, Gt, Le, Lt, Ne +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol) +from sympy.functions.elementary.complexes import Abs +from sympy.functions.elementary.exponential import exp, log +from sympy.functions.elementary.miscellaneous import root, sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import cos, sin, tan +from sympy.integrals.integrals import Integral +from sympy.logic.boolalg import And, Or +from sympy.polys.polytools import Poly, PurePoly +from sympy.sets.sets import FiniteSet, Interval, Union +from sympy.solvers.inequalities import (reduce_inequalities, + solve_poly_inequality as psolve, + reduce_rational_inequalities, + solve_univariate_inequality as isolve, + reduce_abs_inequality, + _solve_inequality) +from sympy.polys.rootoftools import rootof +from sympy.solvers.solvers import solve +from sympy.solvers.solveset import solveset +from sympy.core.mod import Mod +from sympy.abc import x, y + +from sympy.testing.pytest import raises, XFAIL + + +inf = oo.evalf() + + +def test_solve_poly_inequality(): + assert psolve(Poly(0, x), '==') == [S.Reals] + assert psolve(Poly(1, x), '==') == [S.EmptySet] + assert psolve(PurePoly(x + 1, x), ">") == [Interval(-1, oo, True, False)] + + +def test_reduce_poly_inequalities_real_interval(): + assert reduce_rational_inequalities( + [[Eq(x**2, 0)]], x, relational=False) == FiniteSet(0) + assert reduce_rational_inequalities( + [[Le(x**2, 0)]], x, relational=False) == FiniteSet(0) + assert reduce_rational_inequalities( + [[Lt(x**2, 0)]], x, relational=False) == S.EmptySet + assert reduce_rational_inequalities( + [[Ge(x**2, 0)]], x, relational=False) == \ + S.Reals if x.is_real else Interval(-oo, oo) + assert reduce_rational_inequalities( + [[Gt(x**2, 0)]], x, relational=False) == \ + FiniteSet(0).complement(S.Reals) + assert reduce_rational_inequalities( + [[Ne(x**2, 0)]], x, relational=False) == \ + FiniteSet(0).complement(S.Reals) + + assert reduce_rational_inequalities( + [[Eq(x**2, 1)]], x, relational=False) == FiniteSet(-1, 1) + assert reduce_rational_inequalities( + [[Le(x**2, 1)]], x, relational=False) == Interval(-1, 1) + assert reduce_rational_inequalities( + [[Lt(x**2, 1)]], x, relational=False) == Interval(-1, 1, True, True) + assert reduce_rational_inequalities( + [[Ge(x**2, 1)]], x, relational=False) == \ + Union(Interval(-oo, -1), Interval(1, oo)) + assert reduce_rational_inequalities( + [[Gt(x**2, 1)]], x, relational=False) == \ + Interval(-1, 1).complement(S.Reals) + assert reduce_rational_inequalities( + [[Ne(x**2, 1)]], x, relational=False) == \ + FiniteSet(-1, 1).complement(S.Reals) + assert reduce_rational_inequalities([[Eq( + x**2, 1.0)]], x, relational=False) == FiniteSet(-1.0, 1.0).evalf() + assert reduce_rational_inequalities( + [[Le(x**2, 1.0)]], x, relational=False) == Interval(-1.0, 1.0) + assert reduce_rational_inequalities([[Lt( + x**2, 1.0)]], x, relational=False) == Interval(-1.0, 1.0, True, True) + assert reduce_rational_inequalities( + [[Ge(x**2, 1.0)]], x, relational=False) == \ + Union(Interval(-inf, -1.0), Interval(1.0, inf)) + assert reduce_rational_inequalities( + [[Gt(x**2, 1.0)]], x, relational=False) == \ + Union(Interval(-inf, -1.0, right_open=True), + Interval(1.0, inf, left_open=True)) + assert reduce_rational_inequalities([[Ne( + x**2, 1.0)]], x, relational=False) == \ + FiniteSet(-1.0, 1.0).complement(S.Reals) + + s = sqrt(2) + + assert reduce_rational_inequalities([[Lt( + x**2 - 1, 0), Gt(x**2 - 1, 0)]], x, relational=False) == S.EmptySet + assert reduce_rational_inequalities([[Le(x**2 - 1, 0), Ge( + x**2 - 1, 0)]], x, relational=False) == FiniteSet(-1, 1) + assert reduce_rational_inequalities( + [[Le(x**2 - 2, 0), Ge(x**2 - 1, 0)]], x, relational=False + ) == Union(Interval(-s, -1, False, False), Interval(1, s, False, False)) + assert reduce_rational_inequalities( + [[Le(x**2 - 2, 0), Gt(x**2 - 1, 0)]], x, relational=False + ) == Union(Interval(-s, -1, False, True), Interval(1, s, True, False)) + assert reduce_rational_inequalities( + [[Lt(x**2 - 2, 0), Ge(x**2 - 1, 0)]], x, relational=False + ) == Union(Interval(-s, -1, True, False), Interval(1, s, False, True)) + assert reduce_rational_inequalities( + [[Lt(x**2 - 2, 0), Gt(x**2 - 1, 0)]], x, relational=False + ) == Union(Interval(-s, -1, True, True), Interval(1, s, True, True)) + assert reduce_rational_inequalities( + [[Lt(x**2 - 2, 0), Ne(x**2 - 1, 0)]], x, relational=False + ) == Union(Interval(-s, -1, True, True), Interval(-1, 1, True, True), + Interval(1, s, True, True)) + + assert reduce_rational_inequalities([[Lt(x**2, -1.)]], x) is S.false + + +def test_reduce_poly_inequalities_complex_relational(): + assert reduce_rational_inequalities( + [[Eq(x**2, 0)]], x, relational=True) == Eq(x, 0) + assert reduce_rational_inequalities( + [[Le(x**2, 0)]], x, relational=True) == Eq(x, 0) + assert reduce_rational_inequalities( + [[Lt(x**2, 0)]], x, relational=True) == False + assert reduce_rational_inequalities( + [[Ge(x**2, 0)]], x, relational=True) == And(Lt(-oo, x), Lt(x, oo)) + assert reduce_rational_inequalities( + [[Gt(x**2, 0)]], x, relational=True) == \ + And(Gt(x, -oo), Lt(x, oo), Ne(x, 0)) + assert reduce_rational_inequalities( + [[Ne(x**2, 0)]], x, relational=True) == \ + And(Gt(x, -oo), Lt(x, oo), Ne(x, 0)) + + for one in (S.One, S(1.0)): + inf = one*oo + assert reduce_rational_inequalities( + [[Eq(x**2, one)]], x, relational=True) == \ + Or(Eq(x, -one), Eq(x, one)) + assert reduce_rational_inequalities( + [[Le(x**2, one)]], x, relational=True) == \ + And(And(Le(-one, x), Le(x, one))) + assert reduce_rational_inequalities( + [[Lt(x**2, one)]], x, relational=True) == \ + And(And(Lt(-one, x), Lt(x, one))) + assert reduce_rational_inequalities( + [[Ge(x**2, one)]], x, relational=True) == \ + And(Or(And(Le(one, x), Lt(x, inf)), And(Le(x, -one), Lt(-inf, x)))) + assert reduce_rational_inequalities( + [[Gt(x**2, one)]], x, relational=True) == \ + And(Or(And(Lt(-inf, x), Lt(x, -one)), And(Lt(one, x), Lt(x, inf)))) + assert reduce_rational_inequalities( + [[Ne(x**2, one)]], x, relational=True) == \ + Or(And(Lt(-inf, x), Lt(x, -one)), + And(Lt(-one, x), Lt(x, one)), + And(Lt(one, x), Lt(x, inf))) + + +def test_reduce_rational_inequalities_real_relational(): + assert reduce_rational_inequalities([], x) == False + assert reduce_rational_inequalities( + [[(x**2 + 3*x + 2)/(x**2 - 16) >= 0]], x, relational=False) == \ + Union(Interval.open(-oo, -4), Interval(-2, -1), Interval.open(4, oo)) + + assert reduce_rational_inequalities( + [[((-2*x - 10)*(3 - x))/((x**2 + 5)*(x - 2)**2) < 0]], x, + relational=False) == \ + Union(Interval.open(-5, 2), Interval.open(2, 3)) + + assert reduce_rational_inequalities([[(x + 1)/(x - 5) <= 0]], x, + relational=False) == \ + Interval.Ropen(-1, 5) + + assert reduce_rational_inequalities([[(x**2 + 4*x + 3)/(x - 1) > 0]], x, + relational=False) == \ + Union(Interval.open(-3, -1), Interval.open(1, oo)) + + assert reduce_rational_inequalities([[(x**2 - 16)/(x - 1)**2 < 0]], x, + relational=False) == \ + Union(Interval.open(-4, 1), Interval.open(1, 4)) + + assert reduce_rational_inequalities([[(3*x + 1)/(x + 4) >= 1]], x, + relational=False) == \ + Union(Interval.open(-oo, -4), Interval.Ropen(Rational(3, 2), oo)) + + assert reduce_rational_inequalities([[(x - 8)/x <= 3 - x]], x, + relational=False) == \ + Union(Interval.Lopen(-oo, -2), Interval.Lopen(0, 4)) + + # issue sympy/sympy#10237 + assert reduce_rational_inequalities( + [[x < oo, x >= 0, -oo < x]], x, relational=False) == Interval(0, oo) + + +def test_reduce_abs_inequalities(): + e = abs(x - 5) < 3 + ans = And(Lt(2, x), Lt(x, 8)) + assert reduce_inequalities(e) == ans + assert reduce_inequalities(e, x) == ans + assert reduce_inequalities(abs(x - 5)) == Eq(x, 5) + assert reduce_inequalities( + abs(2*x + 3) >= 8) == Or(And(Le(Rational(5, 2), x), Lt(x, oo)), + And(Le(x, Rational(-11, 2)), Lt(-oo, x))) + assert reduce_inequalities(abs(x - 4) + abs( + 3*x - 5) < 7) == And(Lt(S.Half, x), Lt(x, 4)) + assert reduce_inequalities(abs(x - 4) + abs(3*abs(x) - 5) < 7) == \ + Or(And(S(-2) < x, x < -1), And(S.Half < x, x < 4)) + + nr = Symbol('nr', extended_real=False) + raises(TypeError, lambda: reduce_inequalities(abs(nr - 5) < 3)) + assert reduce_inequalities(x < 3, symbols=[x, nr]) == And(-oo < x, x < 3) + + +def test_reduce_inequalities_general(): + assert reduce_inequalities(Ge(sqrt(2)*x, 1)) == And(sqrt(2)/2 <= x, x < oo) + assert reduce_inequalities(x + 1 > 0) == And(S.NegativeOne < x, x < oo) + + +def test_reduce_inequalities_boolean(): + assert reduce_inequalities( + [Eq(x**2, 0), True]) == Eq(x, 0) + assert reduce_inequalities([Eq(x**2, 0), False]) == False + assert reduce_inequalities(x**2 >= 0) is S.true # issue 10196 + + +def test_reduce_inequalities_multivariate(): + assert reduce_inequalities([Ge(x**2, 1), Ge(y**2, 1)]) == And( + Or(And(Le(S.One, x), Lt(x, oo)), And(Le(x, -1), Lt(-oo, x))), + Or(And(Le(S.One, y), Lt(y, oo)), And(Le(y, -1), Lt(-oo, y)))) + + +def test_reduce_inequalities_errors(): + raises(NotImplementedError, lambda: reduce_inequalities(Ge(sin(x) + x, 1))) + raises(NotImplementedError, lambda: reduce_inequalities(Ge(x**2*y + y, 1))) + + +def test__solve_inequalities(): + assert reduce_inequalities(x + y < 1, symbols=[x]) == (x < 1 - y) + assert reduce_inequalities(x + y >= 1, symbols=[x]) == (x < oo) & (x >= -y + 1) + assert reduce_inequalities(Eq(0, x - y), symbols=[x]) == Eq(x, y) + assert reduce_inequalities(Ne(0, x - y), symbols=[x]) == Ne(x, y) + + +def test_issue_6343(): + eq = -3*x**2/2 - x*Rational(45, 4) + Rational(33, 2) > 0 + assert reduce_inequalities(eq) == \ + And(x < Rational(-15, 4) + sqrt(401)/4, -sqrt(401)/4 - Rational(15, 4) < x) + + +def test_issue_8235(): + assert reduce_inequalities(x**2 - 1 < 0) == \ + And(S.NegativeOne < x, x < 1) + assert reduce_inequalities(x**2 - 1 <= 0) == \ + And(S.NegativeOne <= x, x <= 1) + assert reduce_inequalities(x**2 - 1 > 0) == \ + Or(And(-oo < x, x < -1), And(x < oo, S.One < x)) + assert reduce_inequalities(x**2 - 1 >= 0) == \ + Or(And(-oo < x, x <= -1), And(S.One <= x, x < oo)) + + eq = x**8 + x - 9 # we want CRootOf solns here + sol = solve(eq >= 0) + tru = Or(And(rootof(eq, 1) <= x, x < oo), And(-oo < x, x <= rootof(eq, 0))) + assert sol == tru + + # recast vanilla as real + assert solve(sqrt((-x + 1)**2) < 1) == And(S.Zero < x, x < 2) + + +def test_issue_5526(): + assert reduce_inequalities(0 <= + x + Integral(y**2, (y, 1, 3)) - 1, [x]) == \ + (x >= -Integral(y**2, (y, 1, 3)) + 1) + f = Function('f') + e = Sum(f(x), (x, 1, 3)) + assert reduce_inequalities(0 <= x + e + y**2, [x]) == \ + (x >= -y**2 - Sum(f(x), (x, 1, 3))) + + +def test_solve_univariate_inequality(): + assert isolve(x**2 >= 4, x, relational=False) == Union(Interval(-oo, -2), + Interval(2, oo)) + assert isolve(x**2 >= 4, x) == Or(And(Le(2, x), Lt(x, oo)), And(Le(x, -2), + Lt(-oo, x))) + assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x, relational=False) == \ + Union(Interval(1, 2), Interval(3, oo)) + assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x) == \ + Or(And(Le(1, x), Le(x, 2)), And(Le(3, x), Lt(x, oo))) + assert isolve((x - 1)*(x - 2)*(x - 4) < 0, x, domain = FiniteSet(0, 3)) == \ + Or(Eq(x, 0), Eq(x, 3)) + # issue 2785: + assert isolve(x**3 - 2*x - 1 > 0, x, relational=False) == \ + Union(Interval(-1, -sqrt(5)/2 + S.Half, True, True), + Interval(S.Half + sqrt(5)/2, oo, True, True)) + # issue 2794: + assert isolve(x**3 - x**2 + x - 1 > 0, x, relational=False) == \ + Interval(1, oo, True) + #issue 13105 + assert isolve((x + I)*(x + 2*I) < 0, x) == Eq(x, 0) + assert isolve(((x - 1)*(x - 2) + I)*((x - 1)*(x - 2) + 2*I) < 0, x) == Or(Eq(x, 1), Eq(x, 2)) + assert isolve((((x - 1)*(x - 2) + I)*((x - 1)*(x - 2) + 2*I))/(x - 2) > 0, x) == Eq(x, 1) + raises (ValueError, lambda: isolve((x**2 - 3*x*I + 2)/x < 0, x)) + + # numerical testing in valid() is needed + assert isolve(x**7 - x - 2 > 0, x) == \ + And(rootof(x**7 - x - 2, 0) < x, x < oo) + + # handle numerator and denominator; although these would be handled as + # rational inequalities, these test confirm that the right thing is done + # when the domain is EX (e.g. when 2 is replaced with sqrt(2)) + assert isolve(1/(x - 2) > 0, x) == And(S(2) < x, x < oo) + den = ((x - 1)*(x - 2)).expand() + assert isolve((x - 1)/den <= 0, x) == \ + (x > -oo) & (x < 2) & Ne(x, 1) + + n = Dummy('n') + raises(NotImplementedError, lambda: isolve(Abs(x) <= n, x, relational=False)) + c1 = Dummy("c1", positive=True) + raises(NotImplementedError, lambda: isolve(n/c1 < 0, c1)) + n = Dummy('n', negative=True) + assert isolve(n/c1 > -2, c1) == (-n/2 < c1) + assert isolve(n/c1 < 0, c1) == True + assert isolve(n/c1 > 0, c1) == False + + zero = cos(1)**2 + sin(1)**2 - 1 + raises(NotImplementedError, lambda: isolve(x**2 < zero, x)) + raises(NotImplementedError, lambda: isolve( + x**2 < zero*I, x)) + raises(NotImplementedError, lambda: isolve(1/(x - y) < 2, x)) + raises(NotImplementedError, lambda: isolve(1/(x - y) < 0, x)) + raises(TypeError, lambda: isolve(x - I < 0, x)) + + zero = x**2 + x - x*(x + 1) + assert isolve(zero < 0, x, relational=False) is S.EmptySet + assert isolve(zero <= 0, x, relational=False) is S.Reals + + # make sure iter_solutions gets a default value + raises(NotImplementedError, lambda: isolve( + Eq(cos(x)**2 + sin(x)**2, 1), x)) + + +def test_trig_inequalities(): + # all the inequalities are solved in a periodic interval. + assert isolve(sin(x) < S.Half, x, relational=False) == \ + Union(Interval(0, pi/6, False, True), Interval.open(pi*Rational(5, 6), 2*pi)) + assert isolve(sin(x) > S.Half, x, relational=False) == \ + Interval(pi/6, pi*Rational(5, 6), True, True) + assert isolve(cos(x) < S.Zero, x, relational=False) == \ + Interval(pi/2, pi*Rational(3, 2), True, True) + assert isolve(cos(x) >= S.Zero, x, relational=False) == \ + Union(Interval(0, pi/2), Interval.Ropen(pi*Rational(3, 2), 2*pi)) + + assert isolve(tan(x) < S.One, x, relational=False) == \ + Union(Interval.Ropen(0, pi/4), Interval.open(pi/2, pi)) + + assert isolve(sin(x) <= S.Zero, x, relational=False) == \ + Union(FiniteSet(S.Zero), Interval.Ropen(pi, 2*pi)) + + assert isolve(sin(x) <= S.One, x, relational=False) == S.Reals + assert isolve(cos(x) < S(-2), x, relational=False) == S.EmptySet + assert isolve(sin(x) >= S.NegativeOne, x, relational=False) == S.Reals + assert isolve(cos(x) > S.One, x, relational=False) == S.EmptySet + + +def test_issue_9954(): + assert isolve(x**2 >= 0, x, relational=False) == S.Reals + assert isolve(x**2 >= 0, x, relational=True) == S.Reals.as_relational(x) + assert isolve(x**2 < 0, x, relational=False) == S.EmptySet + assert isolve(x**2 < 0, x, relational=True) == S.EmptySet.as_relational(x) + + +@XFAIL +def test_slow_general_univariate(): + r = rootof(x**5 - x**2 + 1, 0) + assert solve(sqrt(x) + 1/root(x, 3) > 1) == \ + Or(And(0 < x, x < r**6), And(r**6 < x, x < oo)) + + +def test_issue_8545(): + eq = 1 - x - abs(1 - x) + ans = And(Lt(1, x), Lt(x, oo)) + assert reduce_abs_inequality(eq, '<', x) == ans + eq = 1 - x - sqrt((1 - x)**2) + assert reduce_inequalities(eq < 0) == ans + + +def test_issue_8974(): + assert isolve(-oo < x, x) == And(-oo < x, x < oo) + assert isolve(oo > x, x) == And(-oo < x, x < oo) + + +def test_issue_10198(): + assert reduce_inequalities( + -1 + 1/abs(1/x - 1) < 0) == (x > -oo) & (x < S(1)/2) & Ne(x, 0) + + assert reduce_inequalities(abs(1/sqrt(x)) - 1, x) == Eq(x, 1) + assert reduce_abs_inequality(-3 + 1/abs(1 - 1/x), '<', x) == \ + Or(And(-oo < x, x < 0), + And(S.Zero < x, x < Rational(3, 4)), And(Rational(3, 2) < x, x < oo)) + raises(ValueError,lambda: reduce_abs_inequality(-3 + 1/abs( + 1 - 1/sqrt(x)), '<', x)) + + +def test_issue_10047(): + # issue 10047: this must remain an inequality, not True, since if x + # is not real the inequality is invalid + # assert solve(sin(x) < 2) == (x <= oo) + + # with PR 16956, (x <= oo) autoevaluates when x is extended_real + # which is assumed in the current implementation of inequality solvers + assert solve(sin(x) < 2) == True + assert solveset(sin(x) < 2, domain=S.Reals) == S.Reals + + +def test_issue_10268(): + assert solve(log(x) < 1000) == And(S.Zero < x, x < exp(1000)) + + +@XFAIL +def test_isolve_Sets(): + n = Dummy('n') + assert isolve(Abs(x) <= n, x, relational=False) == \ + Piecewise((S.EmptySet, n < 0), (Interval(-n, n), True)) + + +def test_integer_domain_relational_isolve(): + + dom = FiniteSet(0, 3) + x = Symbol('x',zero=False) + assert isolve((x - 1)*(x - 2)*(x - 4) < 0, x, domain=dom) == Eq(x, 3) + + x = Symbol('x') + assert isolve(x + 2 < 0, x, domain=S.Integers) == \ + (x <= -3) & (x > -oo) & Eq(Mod(x, 1), 0) + assert isolve(2 * x + 3 > 0, x, domain=S.Integers) == \ + (x >= -1) & (x < oo) & Eq(Mod(x, 1), 0) + assert isolve((x ** 2 + 3 * x - 2) < 0, x, domain=S.Integers) == \ + (x >= -3) & (x <= 0) & Eq(Mod(x, 1), 0) + assert isolve((x ** 2 + 3 * x - 2) > 0, x, domain=S.Integers) == \ + ((x >= 1) & (x < oo) & Eq(Mod(x, 1), 0)) | ( + (x <= -4) & (x > -oo) & Eq(Mod(x, 1), 0)) + + +def test_issue_10671_12466(): + assert solveset(sin(y), y, Interval(0, pi)) == FiniteSet(0, pi) + i = Interval(1, 10) + assert solveset((1/x).diff(x) < 0, x, i) == i + assert solveset((log(x - 6)/x) <= 0, x, S.Reals) == \ + Interval.Lopen(6, 7) + + +def test__solve_inequality(): + for op in (Gt, Lt, Le, Ge, Eq, Ne): + assert _solve_inequality(op(x, 1), x).lhs == x + assert _solve_inequality(op(S.One, x), x).lhs == x + # don't get tricked by symbol on right: solve it + assert _solve_inequality(Eq(2*x - 1, x), x) == Eq(x, 1) + ie = Eq(S.One, y) + assert _solve_inequality(ie, x) == ie + for fx in (x**2, exp(x), sin(x) + cos(x), x*(1 + x)): + for c in (0, 1): + e = 2*fx - c > 0 + assert _solve_inequality(e, x, linear=True) == ( + fx > c/S(2)) + assert _solve_inequality(2*x**2 + 2*x - 1 < 0, x, linear=True) == ( + x*(x + 1) < S.Half) + assert _solve_inequality(Eq(x*y, 1), x) == Eq(x*y, 1) + nz = Symbol('nz', nonzero=True) + assert _solve_inequality(Eq(x*nz, 1), x) == Eq(x, 1/nz) + assert _solve_inequality(x*nz < 1, x) == (x*nz < 1) + a = Symbol('a', positive=True) + assert _solve_inequality(a/x > 1, x) == (S.Zero < x) & (x < a) + assert _solve_inequality(a/x > 1, x, linear=True) == (1/x > 1/a) + # make sure to include conditions under which solution is valid + e = Eq(1 - x, x*(1/x - 1)) + assert _solve_inequality(e, x) == Ne(x, 0) + assert _solve_inequality(x < x*(1/x - 1), x) == (x < S.Half) & Ne(x, 0) + + +def test__pt(): + from sympy.solvers.inequalities import _pt + assert _pt(-oo, oo) == 0 + assert _pt(S.One, S(3)) == 2 + assert _pt(S.One, oo) == _pt(oo, S.One) == 2 + assert _pt(S.One, -oo) == _pt(-oo, S.One) == S.Half + assert _pt(S.NegativeOne, oo) == _pt(oo, S.NegativeOne) == Rational(-1, 2) + assert _pt(S.NegativeOne, -oo) == _pt(-oo, S.NegativeOne) == -2 + assert _pt(x, oo) == _pt(oo, x) == x + 1 + assert _pt(x, -oo) == _pt(-oo, x) == x - 1 + raises(ValueError, lambda: _pt(Dummy('i', infinite=True), S.One)) + + +def test_issue_25697(): + assert _solve_inequality(log(x, 3) <= 2, x) == (x <= 9) & (S.Zero < x) + + +def test_issue_25738(): + assert reduce_inequalities(3 < abs(x) + ) == reduce_inequalities(pi < abs(x)).subs(pi, 3) + + +def test_issue_25983(): + assert(reduce_inequalities(pi/Abs(x) <= 1) == ((pi <= x) & (x < oo)) | ((-oo < x) & (x <= -pi))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_numeric.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_numeric.py new file mode 100644 index 0000000000000000000000000000000000000000..12abd38c80f07279ed41aefc7952762da0f9f430 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_numeric.py @@ -0,0 +1,139 @@ +from sympy.core.function import nfloat +from sympy.core.numbers import (Float, I, Rational, pi) +from sympy.core.relational import Eq +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import sin +from sympy.integrals.integrals import Integral +from sympy.matrices.dense import Matrix +from mpmath import mnorm, mpf +from sympy.solvers import nsolve +from sympy.utilities.lambdify import lambdify +from sympy.testing.pytest import raises, XFAIL +from sympy.utilities.decorator import conserve_mpmath_dps + +@XFAIL +def test_nsolve_fail(): + x = symbols('x') + # Sometimes it is better to use the numerator (issue 4829) + # but sometimes it is not (issue 11768) so leave this to + # the discretion of the user + ans = nsolve(x**2/(1 - x)/(1 - 2*x)**2 - 100, x, 0) + assert ans > 0.46 and ans < 0.47 + + +def test_nsolve_denominator(): + x = symbols('x') + # Test that nsolve uses the full expression (numerator and denominator). + ans = nsolve((x**2 + 3*x + 2)/(x + 2), -2.1) + # The root -2 was divided out, so make sure we don't find it. + assert ans == -1.0 + +def test_nsolve(): + # onedimensional + x = Symbol('x') + assert nsolve(sin(x), 2) - pi.evalf() < 1e-15 + assert nsolve(Eq(2*x, 2), x, -10) == nsolve(2*x - 2, -10) + # Testing checks on number of inputs + raises(TypeError, lambda: nsolve(Eq(2*x, 2))) + raises(TypeError, lambda: nsolve(Eq(2*x, 2), x, 1, 2)) + # multidimensional + x1 = Symbol('x1') + x2 = Symbol('x2') + f1 = 3 * x1**2 - 2 * x2**2 - 1 + f2 = x1**2 - 2 * x1 + x2**2 + 2 * x2 - 8 + f = Matrix((f1, f2)).T + F = lambdify((x1, x2), f.T, modules='mpmath') + for x0 in [(-1, 1), (1, -2), (4, 4), (-4, -4)]: + x = nsolve(f, (x1, x2), x0, tol=1.e-8) + assert mnorm(F(*x), 1) <= 1.e-10 + # The Chinese mathematician Zhu Shijie was the very first to solve this + # nonlinear system 700 years ago (z was added to make it 3-dimensional) + x = Symbol('x') + y = Symbol('y') + z = Symbol('z') + f1 = -x + 2*y + f2 = (x**2 + x*(y**2 - 2) - 4*y) / (x + 4) + f3 = sqrt(x**2 + y**2)*z + f = Matrix((f1, f2, f3)).T + F = lambdify((x, y, z), f.T, modules='mpmath') + + def getroot(x0): + root = nsolve(f, (x, y, z), x0) + assert mnorm(F(*root), 1) <= 1.e-8 + return root + assert list(map(round, getroot((1, 1, 1)))) == [2, 1, 0] + assert nsolve([Eq( + f1, 0), Eq(f2, 0), Eq(f3, 0)], [x, y, z], (1, 1, 1)) # just see that it works + a = Symbol('a') + assert abs(nsolve(1/(0.001 + a)**3 - 6/(0.9 - a)**3, a, 0.3) - + mpf('0.31883011387318591')) < 1e-15 + + +def test_issue_6408(): + x = Symbol('x') + assert nsolve(Piecewise((x, x < 1), (x**2, True)), x, 2) == 0 + + +def test_issue_6408_integral(): + x, y = symbols('x y') + assert nsolve(Integral(x*y, (x, 0, 5)), y, 2) == 0 + + +@conserve_mpmath_dps +def test_increased_dps(): + # Issue 8564 + import mpmath + mpmath.mp.dps = 128 + x = Symbol('x') + e1 = x**2 - pi + q = nsolve(e1, x, 3.0) + + assert abs(sqrt(pi).evalf(128) - q) < 1e-128 + +def test_nsolve_precision(): + x, y = symbols('x y') + sol = nsolve(x**2 - pi, x, 3, prec=128) + assert abs(sqrt(pi).evalf(128) - sol) < 1e-128 + assert isinstance(sol, Float) + + sols = nsolve((y**2 - x, x**2 - pi), (x, y), (3, 3), prec=128) + assert isinstance(sols, Matrix) + assert sols.shape == (2, 1) + assert abs(sqrt(pi).evalf(128) - sols[0]) < 1e-128 + assert abs(sqrt(sqrt(pi)).evalf(128) - sols[1]) < 1e-128 + assert all(isinstance(i, Float) for i in sols) + +def test_nsolve_complex(): + x, y = symbols('x y') + + assert nsolve(x**2 + 2, 1j) == sqrt(2.)*I + assert nsolve(x**2 + 2, I) == sqrt(2.)*I + + assert nsolve([x**2 + 2, y**2 + 2], [x, y], [I, I]) == Matrix([sqrt(2.)*I, sqrt(2.)*I]) + assert nsolve([x**2 + 2, y**2 + 2], [x, y], [I, I]) == Matrix([sqrt(2.)*I, sqrt(2.)*I]) + +def test_nsolve_dict_kwarg(): + x, y = symbols('x y') + # one variable + assert nsolve(x**2 - 2, 1, dict = True) == \ + [{x: sqrt(2.)}] + # one variable with complex solution + assert nsolve(x**2 + 2, I, dict = True) == \ + [{x: sqrt(2.)*I}] + # two variables + assert nsolve([x**2 + y**2 - 5, x**2 - y**2 + 1], [x, y], [1, 1], dict = True) == \ + [{x: sqrt(2.), y: sqrt(3.)}] + +def test_nsolve_rational(): + x = symbols('x') + assert nsolve(x - Rational(1, 3), 0, prec=100) == Rational(1, 3).evalf(100) + + +def test_issue_14950(): + x = Matrix(symbols('t s')) + x0 = Matrix([17, 23]) + eqn = x + x0 + assert nsolve(eqn, x, x0) == nfloat(-x0) + assert nsolve(eqn.T, x.T, x0.T) == nfloat(-x0) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_pde.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_pde.py new file mode 100644 index 0000000000000000000000000000000000000000..948d90c7be21a9e0e03753e723ef04f1fb08a5d6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_pde.py @@ -0,0 +1,239 @@ +from sympy.core.function import (Derivative as D, Function) +from sympy.core.relational import Eq +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.core import S +from sympy.solvers.pde import (pde_separate, pde_separate_add, pde_separate_mul, + pdsolve, classify_pde, checkpdesol) +from sympy.testing.pytest import raises + + +a, b, c, x, y = symbols('a b c x y') + +def test_pde_separate_add(): + x, y, z, t = symbols("x,y,z,t") + F, T, X, Y, Z, u = map(Function, 'FTXYZu') + + eq = Eq(D(u(x, t), x), D(u(x, t), t)*exp(u(x, t))) + res = pde_separate_add(eq, u(x, t), [X(x), T(t)]) + assert res == [D(X(x), x)*exp(-X(x)), D(T(t), t)*exp(T(t))] + + +def test_pde_separate(): + x, y, z, t = symbols("x,y,z,t") + F, T, X, Y, Z, u = map(Function, 'FTXYZu') + + eq = Eq(D(u(x, t), x), D(u(x, t), t)*exp(u(x, t))) + raises(ValueError, lambda: pde_separate(eq, u(x, t), [X(x), T(t)], 'div')) + + +def test_pde_separate_mul(): + x, y, z, t = symbols("x,y,z,t") + c = Symbol("C", real=True) + Phi = Function('Phi') + F, R, T, X, Y, Z, u = map(Function, 'FRTXYZu') + r, theta, z = symbols('r,theta,z') + + # Something simple :) + eq = Eq(D(F(x, y, z), x) + D(F(x, y, z), y) + D(F(x, y, z), z), 0) + + # Duplicate arguments in functions + raises( + ValueError, lambda: pde_separate_mul(eq, F(x, y, z), [X(x), u(z, z)])) + # Wrong number of arguments + raises(ValueError, lambda: pde_separate_mul(eq, F(x, y, z), [X(x), Y(y)])) + # Wrong variables: [x, y] -> [x, z] + raises( + ValueError, lambda: pde_separate_mul(eq, F(x, y, z), [X(t), Y(x, y)])) + + assert pde_separate_mul(eq, F(x, y, z), [Y(y), u(x, z)]) == \ + [D(Y(y), y)/Y(y), -D(u(x, z), x)/u(x, z) - D(u(x, z), z)/u(x, z)] + assert pde_separate_mul(eq, F(x, y, z), [X(x), Y(y), Z(z)]) == \ + [D(X(x), x)/X(x), -D(Z(z), z)/Z(z) - D(Y(y), y)/Y(y)] + + # wave equation + wave = Eq(D(u(x, t), t, t), c**2*D(u(x, t), x, x)) + res = pde_separate_mul(wave, u(x, t), [X(x), T(t)]) + assert res == [D(X(x), x, x)/X(x), D(T(t), t, t)/(c**2*T(t))] + + # Laplace equation in cylindrical coords + eq = Eq(1/r * D(Phi(r, theta, z), r) + D(Phi(r, theta, z), r, 2) + + 1/r**2 * D(Phi(r, theta, z), theta, 2) + D(Phi(r, theta, z), z, 2), 0) + # Separate z + res = pde_separate_mul(eq, Phi(r, theta, z), [Z(z), u(theta, r)]) + assert res == [D(Z(z), z, z)/Z(z), + -D(u(theta, r), r, r)/u(theta, r) - + D(u(theta, r), r)/(r*u(theta, r)) - + D(u(theta, r), theta, theta)/(r**2*u(theta, r))] + # Lets use the result to create a new equation... + eq = Eq(res[1], c) + # ...and separate theta... + res = pde_separate_mul(eq, u(theta, r), [T(theta), R(r)]) + assert res == [D(T(theta), theta, theta)/T(theta), + -r*D(R(r), r)/R(r) - r**2*D(R(r), r, r)/R(r) - c*r**2] + # ...or r... + res = pde_separate_mul(eq, u(theta, r), [R(r), T(theta)]) + assert res == [r*D(R(r), r)/R(r) + r**2*D(R(r), r, r)/R(r) + c*r**2, + -D(T(theta), theta, theta)/T(theta)] + + +def test_issue_11726(): + x, t = symbols("x t") + f = symbols("f", cls=Function) + X, T = symbols("X T", cls=Function) + + u = f(x, t) + eq = u.diff(x, 2) - u.diff(t, 2) + res = pde_separate(eq, u, [T(x), X(t)]) + assert res == [D(T(x), x, x)/T(x),D(X(t), t, t)/X(t)] + + +def test_pde_classify(): + # When more number of hints are added, add tests for classifying here. + f = Function('f') + eq1 = a*f(x,y) + b*f(x,y).diff(x) + c*f(x,y).diff(y) + eq2 = 3*f(x,y) + 2*f(x,y).diff(x) + f(x,y).diff(y) + eq3 = a*f(x,y) + b*f(x,y).diff(x) + 2*f(x,y).diff(y) + eq4 = x*f(x,y) + f(x,y).diff(x) + 3*f(x,y).diff(y) + eq5 = x**2*f(x,y) + x*f(x,y).diff(x) + x*y*f(x,y).diff(y) + eq6 = y*x**2*f(x,y) + y*f(x,y).diff(x) + f(x,y).diff(y) + for eq in [eq1, eq2, eq3]: + assert classify_pde(eq) == ('1st_linear_constant_coeff_homogeneous',) + for eq in [eq4, eq5, eq6]: + assert classify_pde(eq) == ('1st_linear_variable_coeff',) + + +def test_checkpdesol(): + f, F = map(Function, ['f', 'F']) + eq1 = a*f(x,y) + b*f(x,y).diff(x) + c*f(x,y).diff(y) + eq2 = 3*f(x,y) + 2*f(x,y).diff(x) + f(x,y).diff(y) + eq3 = a*f(x,y) + b*f(x,y).diff(x) + 2*f(x,y).diff(y) + for eq in [eq1, eq2, eq3]: + assert checkpdesol(eq, pdsolve(eq))[0] + eq4 = x*f(x,y) + f(x,y).diff(x) + 3*f(x,y).diff(y) + eq5 = 2*f(x,y) + 1*f(x,y).diff(x) + 3*f(x,y).diff(y) + eq6 = f(x,y) + 1*f(x,y).diff(x) + 3*f(x,y).diff(y) + assert checkpdesol(eq4, [pdsolve(eq5), pdsolve(eq6)]) == [ + (False, (x - 2)*F(3*x - y)*exp(-x/S(5) - 3*y/S(5))), + (False, (x - 1)*F(3*x - y)*exp(-x/S(10) - 3*y/S(10)))] + for eq in [eq4, eq5, eq6]: + assert checkpdesol(eq, pdsolve(eq))[0] + sol = pdsolve(eq4) + sol4 = Eq(sol.lhs - sol.rhs, 0) + raises(NotImplementedError, lambda: + checkpdesol(eq4, sol4, solve_for_func=False)) + + +def test_solvefun(): + f, F, G, H = map(Function, ['f', 'F', 'G', 'H']) + eq1 = f(x,y) + f(x,y).diff(x) + f(x,y).diff(y) + assert pdsolve(eq1) == Eq(f(x, y), F(x - y)*exp(-x/2 - y/2)) + assert pdsolve(eq1, solvefun=G) == Eq(f(x, y), G(x - y)*exp(-x/2 - y/2)) + assert pdsolve(eq1, solvefun=H) == Eq(f(x, y), H(x - y)*exp(-x/2 - y/2)) + + +def test_pde_1st_linear_constant_coeff_homogeneous(): + f, F = map(Function, ['f', 'F']) + u = f(x, y) + eq = 2*u + u.diff(x) + u.diff(y) + assert classify_pde(eq) == ('1st_linear_constant_coeff_homogeneous',) + sol = pdsolve(eq) + assert sol == Eq(u, F(x - y)*exp(-x - y)) + assert checkpdesol(eq, sol)[0] + + eq = 4 + (3*u.diff(x)/u) + (2*u.diff(y)/u) + assert classify_pde(eq) == ('1st_linear_constant_coeff_homogeneous',) + sol = pdsolve(eq) + assert sol == Eq(u, F(2*x - 3*y)*exp(-S(12)*x/13 - S(8)*y/13)) + assert checkpdesol(eq, sol)[0] + + eq = u + (6*u.diff(x)) + (7*u.diff(y)) + assert classify_pde(eq) == ('1st_linear_constant_coeff_homogeneous',) + sol = pdsolve(eq) + assert sol == Eq(u, F(7*x - 6*y)*exp(-6*x/S(85) - 7*y/S(85))) + assert checkpdesol(eq, sol)[0] + + eq = a*u + b*u.diff(x) + c*u.diff(y) + sol = pdsolve(eq) + assert checkpdesol(eq, sol)[0] + + +def test_pde_1st_linear_constant_coeff(): + f, F = map(Function, ['f', 'F']) + u = f(x,y) + eq = -2*u.diff(x) + 4*u.diff(y) + 5*u - exp(x + 3*y) + sol = pdsolve(eq) + assert sol == Eq(f(x,y), + (F(4*x + 2*y)*exp(x/2) + exp(x + 4*y)/15)*exp(-y)) + assert classify_pde(eq) == ('1st_linear_constant_coeff', + '1st_linear_constant_coeff_Integral') + assert checkpdesol(eq, sol)[0] + + eq = (u.diff(x)/u) + (u.diff(y)/u) + 1 - (exp(x + y)/u) + sol = pdsolve(eq) + assert sol == Eq(f(x, y), F(x - y)*exp(-x/2 - y/2) + exp(x + y)/3) + assert classify_pde(eq) == ('1st_linear_constant_coeff', + '1st_linear_constant_coeff_Integral') + assert checkpdesol(eq, sol)[0] + + eq = 2*u + -u.diff(x) + 3*u.diff(y) + sin(x) + sol = pdsolve(eq) + assert sol == Eq(f(x, y), + F(3*x + y)*exp(x/5 - 3*y/5) - 2*sin(x)/5 - cos(x)/5) + assert classify_pde(eq) == ('1st_linear_constant_coeff', + '1st_linear_constant_coeff_Integral') + assert checkpdesol(eq, sol)[0] + + eq = u + u.diff(x) + u.diff(y) + x*y + sol = pdsolve(eq) + assert sol.expand() == Eq(f(x, y), + x + y + (x - y)**2/4 - (x + y)**2/4 + F(x - y)*exp(-x/2 - y/2) - 2).expand() + assert classify_pde(eq) == ('1st_linear_constant_coeff', + '1st_linear_constant_coeff_Integral') + assert checkpdesol(eq, sol)[0] + eq = u + u.diff(x) + u.diff(y) + log(x) + assert classify_pde(eq) == ('1st_linear_constant_coeff', + '1st_linear_constant_coeff_Integral') + + +def test_pdsolve_all(): + f, F = map(Function, ['f', 'F']) + u = f(x,y) + eq = u + u.diff(x) + u.diff(y) + x**2*y + sol = pdsolve(eq, hint = 'all') + keys = ['1st_linear_constant_coeff', + '1st_linear_constant_coeff_Integral', 'default', 'order'] + assert sorted(sol.keys()) == keys + assert sol['order'] == 1 + assert sol['default'] == '1st_linear_constant_coeff' + assert sol['1st_linear_constant_coeff'].expand() == Eq(f(x, y), + -x**2*y + x**2 + 2*x*y - 4*x - 2*y + F(x - y)*exp(-x/2 - y/2) + 6).expand() + + +def test_pdsolve_variable_coeff(): + f, F = map(Function, ['f', 'F']) + u = f(x, y) + eq = x*(u.diff(x)) - y*(u.diff(y)) + y**2*u - y**2 + sol = pdsolve(eq, hint="1st_linear_variable_coeff") + assert sol == Eq(u, F(x*y)*exp(y**2/2) + 1) + assert checkpdesol(eq, sol)[0] + + eq = x**2*u + x*u.diff(x) + x*y*u.diff(y) + sol = pdsolve(eq, hint='1st_linear_variable_coeff') + assert sol == Eq(u, F(y*exp(-x))*exp(-x**2/2)) + assert checkpdesol(eq, sol)[0] + + eq = y*x**2*u + y*u.diff(x) + u.diff(y) + sol = pdsolve(eq, hint='1st_linear_variable_coeff') + assert sol == Eq(u, F(-2*x + y**2)*exp(-x**3/3)) + assert checkpdesol(eq, sol)[0] + + eq = exp(x)**2*(u.diff(x)) + y + sol = pdsolve(eq, hint='1st_linear_variable_coeff') + assert sol == Eq(u, y*exp(-2*x)/2 + F(y)) + assert checkpdesol(eq, sol)[0] + + eq = exp(2*x)*(u.diff(y)) + y*u - u + sol = pdsolve(eq, hint='1st_linear_variable_coeff') + assert sol == Eq(u, F(x)*exp(-y*(y - 2)*exp(-2*x)/2)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_polysys.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_polysys.py new file mode 100644 index 0000000000000000000000000000000000000000..a119591a0354ba377a18767eae6e8b7812810a0d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_polysys.py @@ -0,0 +1,462 @@ +"""Tests for solvers of systems of polynomial equations. """ +from sympy.polys.domains import ZZ, QQ_I +from sympy.core.numbers import (I, Integer, Rational) +from sympy.core.singleton import S +from sympy.core.symbol import symbols +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.polys.domains.rationalfield import QQ +from sympy.polys.polyerrors import UnsolvableFactorError +from sympy.polys.polyoptions import Options +from sympy.polys.polytools import Poly +from sympy.polys.rootoftools import CRootOf +from sympy.solvers.solvers import solve +from sympy.utilities.iterables import flatten +from sympy.abc import a, b, c, x, y, z +from sympy.polys import PolynomialError +from sympy.solvers.polysys import (solve_poly_system, + solve_triangulated, + solve_biquadratic, SolveFailed, + solve_generic, factor_system_bool, + factor_system_cond, factor_system_poly, + factor_system, _factor_sets, _factor_sets_slow) +from sympy.polys.polytools import parallel_poly_from_expr +from sympy.testing.pytest import raises +from sympy.core.relational import Eq +from sympy.functions.elementary.trigonometric import sin, cos + +from sympy.functions.elementary.exponential import exp + + +def test_solve_poly_system(): + assert solve_poly_system([x - 1], x) == [(S.One,)] + + assert solve_poly_system([y - x, y - x - 1], x, y) is None + + assert solve_poly_system([y - x**2, y + x**2], x, y) == [(S.Zero, S.Zero)] + + assert solve_poly_system([2*x - 3, y*Rational(3, 2) - 2*x, z - 5*y], x, y, z) == \ + [(Rational(3, 2), Integer(2), Integer(10))] + + assert solve_poly_system([x*y - 2*y, 2*y**2 - x**2], x, y) == \ + [(0, 0), (2, -sqrt(2)), (2, sqrt(2))] + + assert solve_poly_system([y - x**2, y + x**2 + 1], x, y) == \ + [(-I*sqrt(S.Half), Rational(-1, 2)), (I*sqrt(S.Half), Rational(-1, 2))] + + f_1 = x**2 + y + z - 1 + f_2 = x + y**2 + z - 1 + f_3 = x + y + z**2 - 1 + + a, b = sqrt(2) - 1, -sqrt(2) - 1 + + assert solve_poly_system([f_1, f_2, f_3], x, y, z) == \ + [(0, 0, 1), (0, 1, 0), (1, 0, 0), (a, a, a), (b, b, b)] + + solution = [(1, -1), (1, 1)] + + assert solve_poly_system([Poly(x**2 - y**2), Poly(x - 1)]) == solution + assert solve_poly_system([x**2 - y**2, x - 1], x, y) == solution + assert solve_poly_system([x**2 - y**2, x - 1]) == solution + + assert solve_poly_system( + [x + x*y - 3, y + x*y - 4], x, y) == [(-3, -2), (1, 2)] + + raises(NotImplementedError, lambda: solve_poly_system([x**3 - y**3], x, y)) + raises(NotImplementedError, lambda: solve_poly_system( + [z, -2*x*y**2 + x + y**2*z, y**2*(-z - 4) + 2])) + raises(PolynomialError, lambda: solve_poly_system([1/x], x)) + + raises(NotImplementedError, lambda: solve_poly_system( + [x-1,], (x, y))) + raises(NotImplementedError, lambda: solve_poly_system( + [y-1,], (x, y))) + + # solve_poly_system should ideally construct solutions using + # CRootOf for the following four tests + assert solve_poly_system([x**5 - x + 1], [x], strict=False) == [] + raises(UnsolvableFactorError, lambda: solve_poly_system( + [x**5 - x + 1], [x], strict=True)) + + assert solve_poly_system([(x - 1)*(x**5 - x + 1), y**2 - 1], [x, y], + strict=False) == [(1, -1), (1, 1)] + raises(UnsolvableFactorError, + lambda: solve_poly_system([(x - 1)*(x**5 - x + 1), y**2-1], + [x, y], strict=True)) + + +def test_solve_generic(): + NewOption = Options((x, y), {'domain': 'ZZ'}) + assert solve_generic([x**2 - 2*y**2, y**2 - y + 1], NewOption) == \ + [(-sqrt(-1 - sqrt(3)*I), Rational(1, 2) - sqrt(3)*I/2), + (sqrt(-1 - sqrt(3)*I), Rational(1, 2) - sqrt(3)*I/2), + (-sqrt(-1 + sqrt(3)*I), Rational(1, 2) + sqrt(3)*I/2), + (sqrt(-1 + sqrt(3)*I), Rational(1, 2) + sqrt(3)*I/2)] + + # solve_generic should ideally construct solutions using + # CRootOf for the following two tests + assert solve_generic( + [2*x - y, (y - 1)*(y**5 - y + 1)], NewOption, strict=False) == \ + [(Rational(1, 2), 1)] + raises(UnsolvableFactorError, lambda: solve_generic( + [2*x - y, (y - 1)*(y**5 - y + 1)], NewOption, strict=True)) + + +def test_solve_biquadratic(): + x0, y0, x1, y1, r = symbols('x0 y0 x1 y1 r') + + f_1 = (x - 1)**2 + (y - 1)**2 - r**2 + f_2 = (x - 2)**2 + (y - 2)**2 - r**2 + s = sqrt(2*r**2 - 1) + a = (3 - s)/2 + b = (3 + s)/2 + assert solve_poly_system([f_1, f_2], x, y) == [(a, b), (b, a)] + + f_1 = (x - 1)**2 + (y - 2)**2 - r**2 + f_2 = (x - 1)**2 + (y - 1)**2 - r**2 + + assert solve_poly_system([f_1, f_2], x, y) == \ + [(1 - sqrt((2*r - 1)*(2*r + 1))/2, Rational(3, 2)), + (1 + sqrt((2*r - 1)*(2*r + 1))/2, Rational(3, 2))] + + query = lambda expr: expr.is_Pow and expr.exp is S.Half + + f_1 = (x - 1 )**2 + (y - 2)**2 - r**2 + f_2 = (x - x1)**2 + (y - 1)**2 - r**2 + + result = solve_poly_system([f_1, f_2], x, y) + + assert len(result) == 2 and all(len(r) == 2 for r in result) + assert all(r.count(query) == 1 for r in flatten(result)) + + f_1 = (x - x0)**2 + (y - y0)**2 - r**2 + f_2 = (x - x1)**2 + (y - y1)**2 - r**2 + + result = solve_poly_system([f_1, f_2], x, y) + + assert len(result) == 2 and all(len(r) == 2 for r in result) + assert all(len(r.find(query)) == 1 for r in flatten(result)) + + s1 = (x*y - y, x**2 - x) + assert solve(s1) == [{x: 1}, {x: 0, y: 0}] + s2 = (x*y - x, y**2 - y) + assert solve(s2) == [{y: 1}, {x: 0, y: 0}] + gens = (x, y) + for seq in (s1, s2): + (f, g), opt = parallel_poly_from_expr(seq, *gens) + raises(SolveFailed, lambda: solve_biquadratic(f, g, opt)) + seq = (x**2 + y**2 - 2, y**2 - 1) + (f, g), opt = parallel_poly_from_expr(seq, *gens) + assert solve_biquadratic(f, g, opt) == [ + (-1, -1), (-1, 1), (1, -1), (1, 1)] + ans = [(0, -1), (0, 1)] + seq = (x**2 + y**2 - 1, y**2 - 1) + (f, g), opt = parallel_poly_from_expr(seq, *gens) + assert solve_biquadratic(f, g, opt) == ans + seq = (x**2 + y**2 - 1, x**2 - x + y**2 - 1) + (f, g), opt = parallel_poly_from_expr(seq, *gens) + assert solve_biquadratic(f, g, opt) == ans + + +def test_solve_triangulated(): + f_1 = x**2 + y + z - 1 + f_2 = x + y**2 + z - 1 + f_3 = x + y + z**2 - 1 + + a, b = sqrt(2) - 1, -sqrt(2) - 1 + + assert solve_triangulated([f_1, f_2, f_3], x, y, z) == \ + [(0, 0, 1), (0, 1, 0), (1, 0, 0)] + + dom = QQ.algebraic_field(sqrt(2)) + + assert solve_triangulated([f_1, f_2, f_3], x, y, z, domain=dom) == \ + [(0, 0, 1), (0, 1, 0), (1, 0, 0), (a, a, a), (b, b, b)] + + a, b = CRootOf(z**2 + 2*z - 1, 0), CRootOf(z**2 + 2*z - 1, 1) + assert solve_triangulated([f_1, f_2, f_3], x, y, z, extension=True) == \ + [(0, 0, 1), (0, 1, 0), (1, 0, 0), (a, a, a), (b, b, b)] + + +def test_solve_issue_3686(): + roots = solve_poly_system([((x - 5)**2/250000 + (y - Rational(5, 10))**2/250000) - 1, x], x, y) + assert roots == [(0, S.Half - 15*sqrt(1111)), (0, S.Half + 15*sqrt(1111))] + + roots = solve_poly_system([((x - 5)**2/250000 + (y - 5.0/10)**2/250000) - 1, x], x, y) + # TODO: does this really have to be so complicated?! + assert len(roots) == 2 + assert roots[0][0] == 0 + assert roots[0][1].epsilon_eq(-499.474999374969, 1e12) + assert roots[1][0] == 0 + assert roots[1][1].epsilon_eq(500.474999374969, 1e12) + + +def test_factor_system(): + + assert factor_system([x**2 + 2*x + 1]) == [[x + 1]] + assert factor_system([x**2 + 2*x + 1, y**2 + 2*y + 1]) == [[x + 1, y + 1]] + assert factor_system([x**2 + 1]) == [[x**2 + 1]] + assert factor_system([]) == [[]] + + assert factor_system([x**2 + y**2 + 2*x*y, x**2 - 2], extension=sqrt(2)) == [ + [x + y, x + sqrt(2)], + [x + y, x - sqrt(2)], + ] + + assert factor_system([x**2 + 1, y**2 + 1], gaussian=True) == [ + [x + I, y + I], + [x + I, y - I], + [x - I, y + I], + [x - I, y - I], + ] + + assert factor_system([x**2 + 1, y**2 + 1], domain=QQ_I) == [ + [x + I, y + I], + [x + I, y - I], + [x - I, y + I], + [x - I, y - I], + ] + + assert factor_system([0]) == [[]] + assert factor_system([1]) == [] + assert factor_system([0 , x]) == [[x]] + assert factor_system([1, 0, x]) == [] + + assert factor_system([x**4 - 1, y**6 - 1]) == [ + [x**2 + 1, y**2 + y + 1], + [x**2 + 1, y**2 - y + 1], + [x**2 + 1, y + 1], + [x**2 + 1, y - 1], + [x + 1, y**2 + y + 1], + [x + 1, y**2 - y + 1], + [x - 1, y**2 + y + 1], + [x - 1, y**2 - y + 1], + [x + 1, y + 1], + [x + 1, y - 1], + [x - 1, y + 1], + [x - 1, y - 1], + ] + + assert factor_system([(x - 1)*(y - 2), (y - 2)*(z - 3)]) == [ + [x - 1, z - 3], + [y - 2] + ] + + assert factor_system([sin(x)**2 + cos(x)**2 - 1, x]) == [ + [x, sin(x)**2 + cos(x)**2 - 1], + ] + + assert factor_system([sin(x)**2 + cos(x)**2 - 1]) == [ + [sin(x)**2 + cos(x)**2 - 1] + ] + + assert factor_system([sin(x)**2 + cos(x)**2]) == [ + [sin(x)**2 + cos(x)**2] + ] + + assert factor_system([a*x, y, a]) == [[y, a]] + + assert factor_system([a*x, y, a], [x, y]) == [] + + assert factor_system([a ** 2 * x, y], [x, y]) == [[x, y]] + + assert factor_system([a*x*(x - 1), b*y, c], [x, y]) == [] + + assert factor_system([a*x*(x - 1), b*y, c], [x, y, c]) == [ + [x - 1, y, c], + [x, y, c], + ] + + assert factor_system([a*x*(x - 1), b*y, c]) == [ + [x - 1, y, c], + [x, y, c], + [x - 1, b, c], + [x, b, c], + [y, a, c], + [a, b, c], + ] + + assert factor_system([x**2 - 2], [y]) == [] + + assert factor_system([x**2 - 2], [x]) == [[x**2 - 2]] + + assert factor_system([cos(x)**2 - sin(x)**2, cos(x)**2 + sin(x)**2 - 1]) == [ + [sin(x)**2 + cos(x)**2 - 1, sin(x) + cos(x)], + [sin(x)**2 + cos(x)**2 - 1, -sin(x) + cos(x)], + ] + + assert factor_system([(cos(x) + sin(x))**2 - 1, cos(x)**2 - sin(x)**2 - cos(2*x)]) == [ + [sin(x)**2 - cos(x)**2 + cos(2*x), sin(x) + cos(x) + 1], + [sin(x)**2 - cos(x)**2 + cos(2*x), sin(x) + cos(x) - 1], + ] + + assert factor_system([(cos(x) + sin(x))*exp(y) - 1, (cos(x) - sin(x))*exp(y) - 1]) == [ + [exp(y)*sin(x) + exp(y)*cos(x) - 1, -exp(y)*sin(x) + exp(y)*cos(x) - 1] + ] + + +def test_factor_system_poly(): + + px = lambda e: Poly(e, x) + pxab = lambda e: Poly(e, x, domain=ZZ[a, b]) + pxI = lambda e: Poly(e, x, domain=QQ_I) + pxyz = lambda e: Poly(e, (x, y, z)) + + assert factor_system_poly([px(x**2 - 1), px(x**2 - 4)]) == [ + [px(x + 2), px(x + 1)], + [px(x + 2), px(x - 1)], + [px(x + 1), px(x - 2)], + [px(x - 1), px(x - 2)], + ] + + assert factor_system_poly([px(x**2 - 1)]) == [[px(x + 1)], [px(x - 1)]] + + assert factor_system_poly([pxyz(x**2*y - y), pxyz(x**2*z - z)]) == [ + [pxyz(x + 1)], + [pxyz(x - 1)], + [pxyz(y), pxyz(z)], + ] + + assert factor_system_poly([px(x**2*(x - 1)**2), px(x*(x - 1))]) == [ + [px(x)], + [px(x - 1)], + ] + + assert factor_system_poly([pxyz(x**2 + y*x), pxyz(x**2 + z*x)]) == [ + [pxyz(x + y), pxyz(x + z)], + [pxyz(x)], + ] + + assert factor_system_poly([pxab((a - 1)*(x - 2)), pxab((b - 3)*(x - 2))]) == [ + [pxab(x - 2)], + [pxab(a - 1), pxab(b - 3)], + ] + + assert factor_system_poly([pxI(x**2 + 1)]) == [[pxI(x + I)], [pxI(x - I)]] + + assert factor_system_poly([]) == [[]] + + assert factor_system_poly([px(1)]) == [] + assert factor_system_poly([px(0), px(x)]) == [[px(x)]] + + +def test_factor_system_cond(): + + assert factor_system_cond([x ** 2 - 1, x ** 2 - 4]) == [ + [x + 2, x + 1], + [x + 2, x - 1], + [x + 1, x - 2], + [x - 1, x - 2], + ] + + assert factor_system_cond([1]) == [] + assert factor_system_cond([0]) == [[]] + assert factor_system_cond([1, x]) == [] + assert factor_system_cond([0, x]) == [[x]] + assert factor_system_cond([]) == [[]] + + assert factor_system_cond([x**2 + y*x]) == [[x + y], [x]] + + assert factor_system_cond([(a - 1)*(x - 2), (b - 3)*(x - 2)], [x]) == [ + [x - 2], + [a - 1, b - 3], + ] + + assert factor_system_cond([a * (x - 1), b], [x]) == [[x - 1, b], [a, b]] + + assert factor_system_cond([a*x*(x-1), b*y, c], [x, y]) == [ + [x - 1, y, c], + [x, y, c], + [x - 1, b, c], + [x, b, c], + [y, a, c], + [a, b, c], + ] + + assert factor_system_cond([x*(x-1), y], [x, y]) == [[x - 1, y], [x, y]] + + assert factor_system_cond([a*x, y, a], [x, y]) == [[y, a]] + + assert factor_system_cond([a*x, b*x], [x, y]) == [[x], [a, b]] + + assert factor_system_cond([a*b*x, y], [x, y]) == [[x, y], [y, a*b]] + + assert factor_system_cond([a*b*x, y]) == [[x, y], [y, a], [y, b]] + + assert factor_system_cond([a**2*x, y], [x, y]) == [[x, y], [y, a]] + +def test_factor_system_bool(): + + eqs = [a*(x - 1)*(y - 1), b*(x - 2)*(y - 1)*(y - 2)] + assert factor_system_bool(eqs, [x, y]) == ( + Eq(y - 1, 0) + | (Eq(a, 0) & Eq(b, 0)) + | (Eq(a, 0) & Eq(x - 2, 0)) + | (Eq(a, 0) & Eq(y - 2, 0)) + | (Eq(b, 0) & Eq(x - 1, 0)) + | (Eq(x - 2, 0) & Eq(x - 1, 0)) + | (Eq(x - 1, 0) & Eq(y - 2, 0)) + ) + + assert factor_system_bool([x - 1], [x]) == Eq(x - 1, 0) + + assert factor_system_bool([(x - 1)*(x - 2)], [x]) == Eq(x - 2, 0) | Eq(x - 1, 0) + + assert factor_system_bool([], [x]) == True + assert factor_system_bool([0], [x]) == True + assert factor_system_bool([1], [x]) == False + assert factor_system_bool([a], [x]) == Eq(a, 0) + + assert factor_system_bool([a * x, y, a], [x, y]) == Eq(a, 0) & Eq(y, 0) + + assert (factor_system_bool([a*x, b*y*x, a], [x, y]) == ( + Eq(a, 0) & Eq(b, 0)) + | (Eq(a, 0) & Eq(x, 0)) + | (Eq(a, 0) & Eq(y, 0))) + + assert (factor_system_bool([a*x, b*x], [x, y]) == Eq(x, 0) | + (Eq(a, 0) & Eq(b, 0))) + + assert (factor_system_bool([a*b*x, y], [x, y]) == ( + Eq(x, 0) & Eq(y, 0)) | + (Eq(y, 0) & Eq(a*b, 0))) + + assert (factor_system_bool([a**2*x, y], [x, y]) == ( + Eq(a, 0) & Eq(y, 0)) | + (Eq(x, 0) & Eq(y, 0))) + + assert factor_system_bool([a*x*y, b*y*z], [x, y, z]) == ( + Eq(y, 0) + | (Eq(a, 0) & Eq(b, 0)) + | (Eq(a, 0) & Eq(z, 0)) + | (Eq(b, 0) & Eq(x, 0)) + | (Eq(x, 0) & Eq(z, 0)) + ) + + assert factor_system_bool([a*(x - 1), b], [x]) == ( + (Eq(a, 0) & Eq(b, 0)) + | (Eq(x - 1, 0) & Eq(b, 0)) + ) + + +def test_factor_sets(): + # + from random import randint + + def generate_random_system(n_eqs=3, n_factors=2, max_val=10): + return [ + [randint(0, max_val) for _ in range(randint(1, n_factors))] + for _ in range(n_eqs) + ] + + test_cases = [ + [[1, 2], [1, 3]], + [[1, 2], [3, 4]], + [[1], [1, 2], [2]], + ] + + for case in test_cases: + assert _factor_sets(case) == _factor_sets_slow(case) + + for _ in range(100): + system = generate_random_system() + assert _factor_sets(system) == _factor_sets_slow(system) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_recurr.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_recurr.py new file mode 100644 index 0000000000000000000000000000000000000000..5a6306b51a5cf33ccd9fae131430a24690d540a7 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_recurr.py @@ -0,0 +1,295 @@ +from sympy.core.function import (Function, Lambda, expand) +from sympy.core.numbers import (I, Rational) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.combinatorial.factorials import (rf, binomial, factorial) +from sympy.functions.elementary.complexes import Abs +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.polys.polytools import factor +from sympy.solvers.recurr import rsolve, rsolve_hyper, rsolve_poly, rsolve_ratio +from sympy.testing.pytest import raises, slow, XFAIL +from sympy.abc import a, b + +y = Function('y') +n, k = symbols('n,k', integer=True) +C0, C1, C2 = symbols('C0,C1,C2') + + +def test_rsolve_poly(): + assert rsolve_poly([-1, -1, 1], 0, n) == 0 + assert rsolve_poly([-1, -1, 1], 1, n) == -1 + + assert rsolve_poly([-1, n + 1], n, n) == 1 + assert rsolve_poly([-1, 1], n, n) == C0 + (n**2 - n)/2 + assert rsolve_poly([-n - 1, n], 1, n) == C0*n - 1 + assert rsolve_poly([-4*n - 2, 1], 4*n + 1, n) == -1 + + assert rsolve_poly([-1, 1], n**5 + n**3, n) == \ + C0 - n**3 / 2 - n**5 / 2 + n**2 / 6 + n**6 / 6 + 2*n**4 / 3 + + +def test_rsolve_ratio(): + solution = rsolve_ratio([-2*n**3 + n**2 + 2*n - 1, 2*n**3 + n**2 - 6*n, + -2*n**3 - 11*n**2 - 18*n - 9, 2*n**3 + 13*n**2 + 22*n + 8], 0, n) + assert solution == C0*(2*n - 3)/(n**2 - 1)/2 + + +def test_rsolve_hyper(): + assert rsolve_hyper([-1, -1, 1], 0, n) in [ + C0*(S.Half - S.Half*sqrt(5))**n + C1*(S.Half + S.Half*sqrt(5))**n, + C1*(S.Half - S.Half*sqrt(5))**n + C0*(S.Half + S.Half*sqrt(5))**n, + ] + + assert rsolve_hyper([n**2 - 2, -2*n - 1, 1], 0, n) in [ + C0*rf(sqrt(2), n) + C1*rf(-sqrt(2), n), + C1*rf(sqrt(2), n) + C0*rf(-sqrt(2), n), + ] + + assert rsolve_hyper([n**2 - k, -2*n - 1, 1], 0, n) in [ + C0*rf(sqrt(k), n) + C1*rf(-sqrt(k), n), + C1*rf(sqrt(k), n) + C0*rf(-sqrt(k), n), + ] + + assert rsolve_hyper( + [2*n*(n + 1), -n**2 - 3*n + 2, n - 1], 0, n) == C1*factorial(n) + C0*2**n + + assert rsolve_hyper( + [n + 2, -(2*n + 3)*(17*n**2 + 51*n + 39), n + 1], 0, n) == 0 + + assert rsolve_hyper([-n - 1, -1, 1], 0, n) == 0 + + assert rsolve_hyper([-1, 1], n, n).expand() == C0 + n**2/2 - n/2 + + assert rsolve_hyper([-1, 1], 1 + n, n).expand() == C0 + n**2/2 + n/2 + + assert rsolve_hyper([-1, 1], 3*(n + n**2), n).expand() == C0 + n**3 - n + + assert rsolve_hyper([-a, 1],0,n).expand() == C0*a**n + + assert rsolve_hyper([-a, 0, 1], 0, n).expand() == (-1)**n*C1*a**(n/2) + C0*a**(n/2) + + assert rsolve_hyper([1, 1, 1], 0, n).expand() == \ + C0*(Rational(-1, 2) - sqrt(3)*I/2)**n + C1*(Rational(-1, 2) + sqrt(3)*I/2)**n + + assert rsolve_hyper([1, -2*n/a - 2/a, 1], 0, n) == 0 + + +@XFAIL +def test_rsolve_ratio_missed(): + # this arises during computation + # assert rsolve_hyper([-1, 1], 3*(n + n**2), n).expand() == C0 + n**3 - n + assert rsolve_ratio([-n, n + 2], n, n) is not None + + +def recurrence_term(c, f): + """Compute RHS of recurrence in f(n) with coefficients in c.""" + return sum(c[i]*f.subs(n, n + i) for i in range(len(c))) + + +def test_rsolve_bulk(): + """Some bulk-generated tests.""" + funcs = [ n, n + 1, n**2, n**3, n**4, n + n**2, 27*n + 52*n**2 - 3* + n**3 + 12*n**4 - 52*n**5 ] + coeffs = [ [-2, 1], [-2, -1, 1], [-1, 1, 1, -1, 1], [-n, 1], [n**2 - + n + 12, 1] ] + for p in funcs: + # compute difference + for c in coeffs: + q = recurrence_term(c, p) + if p.is_polynomial(n): + assert rsolve_poly(c, q, n) == p + # See issue 3956: + if p.is_hypergeometric(n) and len(c) <= 3: + assert rsolve_hyper(c, q, n).subs(zip(symbols('C:3'), [0, 0, 0])).expand() == p + + +def test_rsolve_0_sol_homogeneous(): + # fixed by cherry-pick from + # https://github.com/diofant/diofant/commit/e1d2e52125199eb3df59f12e8944f8a5f24b00a5 + assert rsolve_hyper([n**2 - n + 12, 1], n*(n**2 - n + 12) + n + 1, n) == n + + +def test_rsolve(): + f = y(n + 2) - y(n + 1) - y(n) + h = sqrt(5)*(S.Half + S.Half*sqrt(5))**n \ + - sqrt(5)*(S.Half - S.Half*sqrt(5))**n + + assert rsolve(f, y(n)) in [ + C0*(S.Half - S.Half*sqrt(5))**n + C1*(S.Half + S.Half*sqrt(5))**n, + C1*(S.Half - S.Half*sqrt(5))**n + C0*(S.Half + S.Half*sqrt(5))**n, + ] + + assert rsolve(f, y(n), [0, 5]) == h + assert rsolve(f, y(n), {0: 0, 1: 5}) == h + assert rsolve(f, y(n), {y(0): 0, y(1): 5}) == h + assert rsolve(y(n) - y(n - 1) - y(n - 2), y(n), [0, 5]) == h + assert rsolve(Eq(y(n), y(n - 1) + y(n - 2)), y(n), [0, 5]) == h + + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + f = (n - 1)*y(n + 2) - (n**2 + 3*n - 2)*y(n + 1) + 2*n*(n + 1)*y(n) + g = C1*factorial(n) + C0*2**n + h = -3*factorial(n) + 3*2**n + + assert rsolve(f, y(n)) == g + assert rsolve(f, y(n), []) == g + assert rsolve(f, y(n), {}) == g + + assert rsolve(f, y(n), [0, 3]) == h + assert rsolve(f, y(n), {0: 0, 1: 3}) == h + assert rsolve(f, y(n), {y(0): 0, y(1): 3}) == h + + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + f = y(n) - y(n - 1) - 2 + + assert rsolve(f, y(n), {y(0): 0}) == 2*n + assert rsolve(f, y(n), {y(0): 1}) == 2*n + 1 + assert rsolve(f, y(n), {y(0): 0, y(1): 1}) is None + + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + f = 3*y(n - 1) - y(n) - 1 + + assert rsolve(f, y(n), {y(0): 0}) == -3**n/2 + S.Half + assert rsolve(f, y(n), {y(0): 1}) == 3**n/2 + S.Half + assert rsolve(f, y(n), {y(0): 2}) == 3*3**n/2 + S.Half + + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + f = y(n) - 1/n*y(n - 1) + assert rsolve(f, y(n)) == C0/factorial(n) + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + f = y(n) - 1/n*y(n - 1) - 1 + assert rsolve(f, y(n)) is None + + f = 2*y(n - 1) + (1 - n)*y(n)/n + + assert rsolve(f, y(n), {y(1): 1}) == 2**(n - 1)*n + assert rsolve(f, y(n), {y(1): 2}) == 2**(n - 1)*n*2 + assert rsolve(f, y(n), {y(1): 3}) == 2**(n - 1)*n*3 + + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + f = (n - 1)*(n - 2)*y(n + 2) - (n + 1)*(n + 2)*y(n) + + assert rsolve(f, y(n), {y(3): 6, y(4): 24}) == n*(n - 1)*(n - 2) + assert rsolve( + f, y(n), {y(3): 6, y(4): -24}) == -n*(n - 1)*(n - 2)*(-1)**(n) + + assert f.subs(y, Lambda(k, rsolve(f, y(n)).subs(n, k))).simplify() == 0 + + assert rsolve(Eq(y(n + 1), a*y(n)), y(n), {y(1): a}).simplify() == a**n + + assert rsolve(y(n) - a*y(n-2),y(n), \ + {y(1): sqrt(a)*(a + b), y(2): a*(a - b)}).simplify() == \ + a**(n/2 + 1) - b*(-sqrt(a))**n + + f = (-16*n**2 + 32*n - 12)*y(n - 1) + (4*n**2 - 12*n + 9)*y(n) + + yn = rsolve(f, y(n), {y(1): binomial(2*n + 1, 3)}) + sol = 2**(2*n)*n*(2*n - 1)**2*(2*n + 1)/12 + assert factor(expand(yn, func=True)) == sol + + sol = rsolve(y(n) + a*(y(n + 1) + y(n - 1))/2, y(n)) + assert str(sol) == 'C0*((-sqrt(1 - a**2) - 1)/a)**n + C1*((sqrt(1 - a**2) - 1)/a)**n' + + assert rsolve((k + 1)*y(k), y(k)) is None + assert (rsolve((k + 1)*y(k) + (k + 3)*y(k + 1) + (k + 5)*y(k + 2), y(k)) + is None) + + assert rsolve(y(n) + y(n + 1) + 2**n + 3**n, y(n)) == (-1)**n*C0 - 2**n/3 - 3**n/4 + + +def test_rsolve_raises(): + x = Function('x') + raises(ValueError, lambda: rsolve(y(n) - y(k + 1), y(n))) + raises(ValueError, lambda: rsolve(y(n) - y(n + 1), x(n))) + raises(ValueError, lambda: rsolve(y(n) - x(n + 1), y(n))) + raises(ValueError, lambda: rsolve(y(n) - sqrt(n)*y(n + 1), y(n))) + raises(ValueError, lambda: rsolve(y(n) - y(n + 1), y(n), {x(0): 0})) + raises(ValueError, lambda: rsolve(y(n) + y(n + 1) + 2**n + cos(n), y(n))) + + +def test_issue_6844(): + f = y(n + 2) - y(n + 1) + y(n)/4 + assert rsolve(f, y(n)) == 2**(-n + 1)*C1*n + 2**(-n)*C0 + assert rsolve(f, y(n), {y(0): 0, y(1): 1}) == 2**(1 - n)*n + + +def test_issue_18751(): + r = Symbol('r', positive=True) + theta = Symbol('theta', real=True) + f = y(n) - 2 * r * cos(theta) * y(n - 1) + r**2 * y(n - 2) + assert rsolve(f, y(n)) == \ + C0*(r*(cos(theta) - I*Abs(sin(theta))))**n + C1*(r*(cos(theta) + I*Abs(sin(theta))))**n + + +def test_constant_naming(): + #issue 8697 + assert rsolve(y(n+3) - y(n+2) - y(n+1) + y(n), y(n)) == (-1)**n*C1 + C0 + C2*n + assert rsolve(y(n+3)+3*y(n+2)+3*y(n+1)+y(n), y(n)).expand() == (-1)**n*C0 - (-1)**n*C1*n - (-1)**n*C2*n**2 + assert rsolve(y(n) - 2*y(n - 3) + 5*y(n - 2) - 4*y(n - 1),y(n),[1,3,8]) == 3*2**n - n - 2 + + #issue 19630 + assert rsolve(y(n+3) - 3*y(n+1) + 2*y(n), y(n), {y(1):0, y(2):8, y(3):-2}) == (-2)**n + 2*n + + +@slow +def test_issue_15751(): + f = y(n) + 21*y(n + 1) - 273*y(n + 2) - 1092*y(n + 3) + 1820*y(n + 4) + 1092*y(n + 5) - 273*y(n + 6) - 21*y(n + 7) + y(n + 8) + assert rsolve(f, y(n)) is not None + + +def test_issue_17990(): + f = -10*y(n) + 4*y(n + 1) + 6*y(n + 2) + 46*y(n + 3) + sol = rsolve(f, y(n)) + expected = C0*((86*18**(S(1)/3)/69 + (-12 + (-1 + sqrt(3)*I)*(290412 + + 3036*sqrt(9165))**(S(1)/3))*(1 - sqrt(3)*I)*(24201 + 253*sqrt(9165))** + (S(1)/3)/276)/((1 - sqrt(3)*I)*(24201 + 253*sqrt(9165))**(S(1)/3)) + )**n + C1*((86*18**(S(1)/3)/69 + (-12 + (-1 - sqrt(3)*I)*(290412 + 3036 + *sqrt(9165))**(S(1)/3))*(1 + sqrt(3)*I)*(24201 + 253*sqrt(9165))** + (S(1)/3)/276)/((1 + sqrt(3)*I)*(24201 + 253*sqrt(9165))**(S(1)/3)) + )**n + C2*(-43*18**(S(1)/3)/(69*(24201 + 253*sqrt(9165))**(S(1)/3)) - + S(1)/23 + (290412 + 3036*sqrt(9165))**(S(1)/3)/138)**n + assert sol == expected + e = sol.subs({C0: 1, C1: 1, C2: 1, n: 1}).evalf() + assert abs(e + 0.130434782608696) < 1e-13 + + +def test_issue_8697(): + a = Function('a') + eq = a(n + 3) - a(n + 2) - a(n + 1) + a(n) + assert rsolve(eq, a(n)) == (-1)**n*C1 + C0 + C2*n + eq2 = a(n + 3) + 3*a(n + 2) + 3*a(n + 1) + a(n) + assert (rsolve(eq2, a(n)) == + (-1)**n*C0 + (-1)**(n + 1)*C1*n + (-1)**(n + 1)*C2*n**2) + + assert rsolve(a(n) - 2*a(n - 3) + 5*a(n - 2) - 4*a(n - 1), + a(n), {a(0): 1, a(1): 3, a(2): 8}) == 3*2**n - n - 2 + + # From issue thread (but fixed by https://github.com/diofant/diofant/commit/da9789c6cd7d0c2ceeea19fbf59645987125b289): + assert rsolve(a(n) - 2*a(n - 1) - n, a(n), {a(0): 1}) == 3*2**n - n - 2 + + +def test_diofantissue_294(): + f = y(n) - y(n - 1) - 2*y(n - 2) - 2*n + assert rsolve(f, y(n)) == (-1)**n*C0 + 2**n*C1 - n - Rational(5, 2) + # issue sympy/sympy#11261 + assert rsolve(f, y(n), {y(0): -1, y(1): 1}) == (-(-1)**n/2 + 2*2**n - + n - Rational(5, 2)) + # issue sympy/sympy#7055 + assert rsolve(-2*y(n) + y(n + 1) + n - 1, y(n)) == 2**n*C0 + n + + +def test_issue_15553(): + f = Function("f") + assert rsolve(Eq(f(n), 2*f(n - 1) + n), f(n)) == 2**n*C0 - n - 2 + assert rsolve(Eq(f(n + 1), 2*f(n) + n**2 + 1), f(n)) == 2**n*C0 - n**2 - 2*n - 4 + assert rsolve(Eq(f(n + 1), 2*f(n) + n**2 + 1), f(n), {f(1): 0}) == 7*2**n/2 - n**2 - 2*n - 4 + assert rsolve(Eq(f(n), 2*f(n - 1) + 3*n**2), f(n)) == 2**n*C0 - 3*n**2 - 12*n - 18 + assert rsolve(Eq(f(n), 2*f(n - 1) + n**2), f(n)) == 2**n*C0 - n**2 - 4*n - 6 + assert rsolve(Eq(f(n), 2*f(n - 1) + n), f(n), {f(0): 1}) == 3*2**n - n - 2 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_simplex.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_simplex.py new file mode 100644 index 0000000000000000000000000000000000000000..611205f5df009a6d0de6e687501695b63bb932c9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_simplex.py @@ -0,0 +1,254 @@ +from sympy.core.numbers import Rational +from sympy.core.relational import Eq, Ne +from sympy.core.symbol import symbols +from sympy.core.sympify import sympify +from sympy.core.singleton import S +from sympy.core.random import random, choice +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.ntheory.generate import randprime +from sympy.matrices.dense import Matrix +from sympy.solvers.solveset import linear_eq_to_matrix +from sympy.solvers.simplex import (_lp as lp, _primal_dual, + UnboundedLPError, InfeasibleLPError, lpmin, lpmax, + _m, _abcd, _simplex, linprog) + +from sympy.external.importtools import import_module + +from sympy.testing.pytest import raises + +from sympy.abc import x, y, z + + +np = import_module("numpy") +scipy = import_module("scipy") + + +def test_lp(): + r1 = y + 2*z <= 3 + r2 = -x - 3*z <= -2 + r3 = 2*x + y + 7*z <= 5 + constraints = [r1, r2, r3, x >= 0, y >= 0, z >= 0] + objective = -x - y - 5 * z + ans = optimum, argmax = lp(max, objective, constraints) + assert ans == lpmax(objective, constraints) + assert objective.subs(argmax) == optimum + for constr in constraints: + assert constr.subs(argmax) == True + + r1 = x - y + 2*z <= 3 + r2 = -x + 2*y - 3*z <= -2 + r3 = 2*x + y - 7*z <= -5 + constraints = [r1, r2, r3, x >= 0, y >= 0, z >= 0] + objective = -x - y - 5*z + ans = optimum, argmax = lp(max, objective, constraints) + assert ans == lpmax(objective, constraints) + assert objective.subs(argmax) == optimum + for constr in constraints: + assert constr.subs(argmax) == True + + r1 = x - y + 2*z <= -4 + r2 = -x + 2*y - 3*z <= 8 + r3 = 2*x + y - 7*z <= 10 + constraints = [r1, r2, r3, x >= 0, y >= 0, z >= 0] + const = 2 + objective = -x-y-5*z+const # has constant term + ans = optimum, argmax = lp(max, objective, constraints) + assert ans == lpmax(objective, constraints) + assert objective.subs(argmax) == optimum + for constr in constraints: + assert constr.subs(argmax) == True + + # Section 4 Problem 1 from + # http://web.tecnico.ulisboa.pt/mcasquilho/acad/or/ftp/FergusonUCLA_LP.pdf + # answer on page 55 + v = x1, x2, x3, x4 = symbols('x1 x2 x3 x4') + r1 = x1 - x2 - 2*x3 - x4 <= 4 + r2 = 2*x1 + x3 -4*x4 <= 2 + r3 = -2*x1 + x2 + x4 <= 1 + objective, constraints = x1 - 2*x2 - 3*x3 - x4, [r1, r2, r3] + [ + i >= 0 for i in v] + ans = optimum, argmax = lp(max, objective, constraints) + assert ans == lpmax(objective, constraints) + assert ans == (4, {x1: 7, x2: 0, x3: 0, x4: 3}) + + # input contains Floats + r1 = x - y + 2.0*z <= -4 + r2 = -x + 2*y - 3.0*z <= 8 + r3 = 2*x + y - 7*z <= 10 + constraints = [r1, r2, r3] + [i >= 0 for i in (x, y, z)] + objective = -x-y-5*z + optimum, argmax = lp(max, objective, constraints) + assert objective.subs(argmax) == optimum + for constr in constraints: + assert constr.subs(argmax) == True + + # input contains non-float or non-Rational + r1 = x - y + sqrt(2) * z <= -4 + r2 = -x + 2*y - 3*z <= 8 + r3 = 2*x + y - 7*z <= 10 + raises(TypeError, lambda: lp(max, -x-y-5*z, [r1, r2, r3])) + + r1 = x >= 0 + raises(UnboundedLPError, lambda: lp(max, x, [r1])) + r2 = x <= -1 + raises(InfeasibleLPError, lambda: lp(max, x, [r1, r2])) + + # strict inequalities are not allowed + r1 = x > 0 + raises(TypeError, lambda: lp(max, x, [r1])) + + # not equals not allowed + r1 = Ne(x, 0) + raises(TypeError, lambda: lp(max, x, [r1])) + + def make_random_problem(nvar=2, num_constraints=2, sparsity=.1): + def rand(): + if random() < sparsity: + return sympify(0) + int1, int2 = [randprime(0, 200) for _ in range(2)] + return Rational(int1, int2)*choice([-1, 1]) + variables = symbols('x1:%s' % (nvar + 1)) + constraints = [(sum(rand()*x for x in variables) <= rand()) + for _ in range(num_constraints)] + objective = sum(rand() * x for x in variables) + return objective, constraints, variables + + # equality + r1 = Eq(x, y) + r2 = Eq(y, z) + r3 = z <= 3 + constraints = [r1, r2, r3] + objective = x + ans = optimum, argmax = lp(max, objective, constraints) + assert ans == lpmax(objective, constraints) + assert objective.subs(argmax) == optimum + for constr in constraints: + assert constr.subs(argmax) == True + + +def test_simplex(): + L = [ + [[1, 1], [-1, 1], [0, 1], [-1, 0]], + [5, 1, 2, -1], + [[1, 1]], + [-1]] + A, B, C, D = _abcd(_m(*L), list=False) + assert _simplex(A, B, -C, -D) == (-6, [3, 2], [1, 0, 0, 0]) + assert _simplex(A, B, -C, -D, dual=True) == (-6, + [1, 0, 0, 0], [5, 0]) + + assert _simplex([[]],[],[[1]],[0]) == (0, [0], []) + + # handling of Eq (or Eq-like x<=y, x>=y conditions) + assert lpmax(x - y, [x <= y + 2, x >= y + 2, x >= 0, y >= 0] + ) == (2, {x: 2, y: 0}) + assert lpmax(x - y, [x <= y + 2, Eq(x, y + 2), x >= 0, y >= 0] + ) == (2, {x: 2, y: 0}) + assert lpmax(x - y, [x <= y + 2, Eq(x, 2)]) == (2, {x: 2, y: 0}) + assert lpmax(y, [Eq(y, 2)]) == (2, {y: 2}) + + # the conditions are equivalent to Eq(x, y + 2) + assert lpmin(y, [x <= y + 2, x >= y + 2, y >= 0] + ) == (0, {x: 2, y: 0}) + # equivalent to Eq(y, -2) + assert lpmax(y, [0 <= y + 2, 0 >= y + 2]) == (-2, {y: -2}) + assert lpmax(y, [0 <= y + 2, 0 >= y + 2, y <= 0] + ) == (-2, {y: -2}) + + # extra symbols symbols + assert lpmin(x, [y >= 1, x >= y]) == (1, {x: 1, y: 1}) + assert lpmin(x, [y >= 1, x >= y + z, x >= 0, z >= 0] + ) == (1, {x: 1, y: 1, z: 0}) + + # detect oscillation + # o1 + v = x1, x2, x3, x4 = symbols('x1 x2 x3 x4') + raises(InfeasibleLPError, lambda: lpmin( + 9*x2 - 8*x3 + 3*x4 + 6, + [5*x2 - 2*x3 <= 0, + -x1 - 8*x2 + 9*x3 <= -3, + 10*x1 - x2+ 9*x4 <= -4] + [i >= 0 for i in v])) + # o2 - equations fed to lpmin are changed into a matrix + # system that doesn't oscillate and has the same solution + # as below + M = linear_eq_to_matrix + f = 5*x2 + x3 + 4*x4 - x1 + L = 5*x2 + 2*x3 + 5*x4 - (x1 + 5) + cond = [L <= 0] + [Eq(3*x2 + x4, 2), Eq(-x1 + x3 + 2*x4, 1)] + c, d = M(f, v) + a, b = M(L, v) + aeq, beq = M(cond[1:], v) + ans = (S(9)/2, [0, S(1)/2, 0, S(1)/2]) + assert linprog(c, a, b, aeq, beq, bounds=(0, 1)) == ans + lpans = lpmin(f, cond + [x1 >= 0, x1 <= 1, + x2 >= 0, x2 <= 1, x3 >= 0, x3 <= 1, x4 >= 0, x4 <= 1]) + assert (lpans[0], list(lpans[1].values())) == ans + + +def test_lpmin_lpmax(): + v = x1, x2, y1, y2 = symbols('x1 x2 y1 y2') + L = [[1, -1]], [1], [[1, 1]], [2] + a, b, c, d = [Matrix(i) for i in L] + m = Matrix([[a, b], [c, d]]) + f, constr = _primal_dual(m)[0] + ans = lpmin(f, constr + [i >= 0 for i in v[:2]]) + assert ans == (-1, {x1: 1, x2: 0}),ans + + L = [[1, -1], [1, 1]], [1, 1], [[1, 1]], [2] + a, b, c, d = [Matrix(i) for i in L] + m = Matrix([[a, b], [c, d]]) + f, constr = _primal_dual(m)[1] + ans = lpmax(f, constr + [i >= 0 for i in v[-2:]]) + assert ans == (-1, {y1: 1, y2: 0}) + + +def test_linprog(): + for do in range(2): + if not do: + M = lambda a, b: linear_eq_to_matrix(a, b) + else: + # check matrices as list + M = lambda a, b: tuple([ + i.tolist() for i in linear_eq_to_matrix(a, b)]) + + v = x, y, z = symbols('x1:4') + f = x + y - 2*z + c = M(f, v)[0] + ineq = [7*x + 4*y - 7*z <= 3, + 3*x - y + 10*z <= 6, + x >= 0, y >= 0, z >= 0] + ab = M([i.lts - i.gts for i in ineq], v) + ans = (-S(6)/5, [0, 0, S(3)/5]) + assert lpmin(f, ineq) == (ans[0], dict(zip(v, ans[1]))) + assert linprog(c, *ab) == ans + + f += 1 + c = M(f, v)[0] + eq = [Eq(y - 9*x, 1)] + abeq = M([i.lhs - i.rhs for i in eq], v) + ans = (1 - S(2)/5, [0, 1, S(7)/10]) + assert lpmin(f, ineq + eq) == (ans[0], dict(zip(v, ans[1]))) + assert linprog(c, *ab, *abeq) == (ans[0] - 1, ans[1]) + + eq = [z - y <= S.Half] + abeq = M([i.lhs - i.rhs for i in eq], v) + ans = (1 - S(10)/9, [0, S(1)/9, S(11)/18]) + assert lpmin(f, ineq + eq) == (ans[0], dict(zip(v, ans[1]))) + assert linprog(c, *ab, *abeq) == (ans[0] - 1, ans[1]) + + bounds = [(0, None), (0, None), (None, S.Half)] + ans = (0, [0, 0, S.Half]) + assert lpmin(f, ineq + [z <= S.Half]) == ( + ans[0], dict(zip(v, ans[1]))) + assert linprog(c, *ab, bounds=bounds) == (ans[0] - 1, ans[1]) + assert linprog(c, *ab, bounds={v.index(z): bounds[-1]} + ) == (ans[0] - 1, ans[1]) + eq = [z - y <= S.Half] + + assert linprog([[1]], [], [], bounds=(2, 3)) == (2, [2]) + assert linprog([1], [], [], bounds=(2, 3)) == (2, [2]) + assert linprog([1], bounds=(2, 3)) == (2, [2]) + assert linprog([1, -1], [[1, 1]], [2], bounds={1:(None, None)} + ) == (-2, [0, 2]) + assert linprog([1, -1], [[1, 1]], [5], bounds={1:(3, None)} + ) == (-5, [0, 5]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_solvers.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_solvers.py new file mode 100644 index 0000000000000000000000000000000000000000..ac9550ad404c2ec7592caf6afd2910f425138987 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_solvers.py @@ -0,0 +1,2725 @@ +from sympy.assumptions.ask import (Q, ask) +from sympy.core.add import Add +from sympy.core.containers import Tuple +from sympy.core.function import (Derivative, Function, diff) +from sympy.core.mod import Mod +from sympy.core.mul import Mul +from sympy.core import (GoldenRatio, TribonacciConstant) +from sympy.core.numbers import (E, Float, I, Rational, oo, pi) +from sympy.core.relational import (Eq, Gt, Lt, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol, Wild, symbols) +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import binomial +from sympy.functions.elementary.complexes import (Abs, arg, conjugate, im, re) +from sympy.functions.elementary.exponential import (LambertW, exp, log) +from sympy.functions.elementary.hyperbolic import (atanh, cosh, sinh, tanh) +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.miscellaneous import (cbrt, root, sqrt) +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (acos, asin, atan, atan2, cos, sec, sin, tan) +from sympy.functions.special.error_functions import (erf, erfc, erfcinv, erfinv) +from sympy.integrals.integrals import Integral +from sympy.logic.boolalg import (And, Or) +from sympy.matrices.dense import Matrix +from sympy.matrices import MatrixSymbol, SparseMatrix +from sympy.polys.polytools import Poly, groebner +from sympy.printing.str import sstr +from sympy.simplify.radsimp import denom +from sympy.solvers.solvers import (nsolve, solve, solve_linear) + +from sympy.core.function import nfloat +from sympy.solvers import solve_linear_system, solve_linear_system_LU, \ + solve_undetermined_coeffs +from sympy.solvers.bivariate import _filtered_gens, _solve_lambert, _lambert +from sympy.solvers.solvers import _invert, unrad, checksol, posify, _ispow, \ + det_quick, det_perm, det_minor, _simple_dens, denoms + +from sympy.physics.units import cm +from sympy.polys.rootoftools import CRootOf + +from sympy.testing.pytest import slow, XFAIL, SKIP, raises +from sympy.core.random import verify_numerically as tn + +from sympy.abc import a, b, c, d, e, k, h, p, x, y, z, t, q, m, R + + +def NS(e, n=15, **options): + return sstr(sympify(e).evalf(n, **options), full_prec=True) + + +def test_swap_back(): + f, g = map(Function, 'fg') + fx, gx = f(x), g(x) + assert solve([fx + y - 2, fx - gx - 5], fx, y, gx) == \ + {fx: gx + 5, y: -gx - 3} + assert solve(fx + gx*x - 2, [fx, gx], dict=True) == [{fx: 2, gx: 0}] + assert solve(fx + gx**2*x - y, [fx, gx], dict=True) == [{fx: y, gx: 0}] + assert solve([f(1) - 2, x + 2], dict=True) == [{x: -2, f(1): 2}] + + +def guess_solve_strategy(eq, symbol): + try: + solve(eq, symbol) + return True + except (TypeError, NotImplementedError): + return False + + +def test_guess_poly(): + # polynomial equations + assert guess_solve_strategy( S(4), x ) # == GS_POLY + assert guess_solve_strategy( x, x ) # == GS_POLY + assert guess_solve_strategy( x + a, x ) # == GS_POLY + assert guess_solve_strategy( 2*x, x ) # == GS_POLY + assert guess_solve_strategy( x + sqrt(2), x) # == GS_POLY + assert guess_solve_strategy( x + 2**Rational(1, 4), x) # == GS_POLY + assert guess_solve_strategy( x**2 + 1, x ) # == GS_POLY + assert guess_solve_strategy( x**2 - 1, x ) # == GS_POLY + assert guess_solve_strategy( x*y + y, x ) # == GS_POLY + assert guess_solve_strategy( x*exp(y) + y, x) # == GS_POLY + assert guess_solve_strategy( + (x - y**3)/(y**2*sqrt(1 - y**2)), x) # == GS_POLY + + +def test_guess_poly_cv(): + # polynomial equations via a change of variable + assert guess_solve_strategy( sqrt(x) + 1, x ) # == GS_POLY_CV_1 + assert guess_solve_strategy( + x**Rational(1, 3) + sqrt(x) + 1, x ) # == GS_POLY_CV_1 + assert guess_solve_strategy( 4*x*(1 - sqrt(x)), x ) # == GS_POLY_CV_1 + + # polynomial equation multiplying both sides by x**n + assert guess_solve_strategy( x + 1/x + y, x ) # == GS_POLY_CV_2 + + +def test_guess_rational_cv(): + # rational functions + assert guess_solve_strategy( (x + 1)/(x**2 + 2), x) # == GS_RATIONAL + assert guess_solve_strategy( + (x - y**3)/(y**2*sqrt(1 - y**2)), y) # == GS_RATIONAL_CV_1 + + # rational functions via the change of variable y -> x**n + assert guess_solve_strategy( (sqrt(x) + 1)/(x**Rational(1, 3) + sqrt(x) + 1), x ) \ + #== GS_RATIONAL_CV_1 + + +def test_guess_transcendental(): + #transcendental functions + assert guess_solve_strategy( exp(x) + 1, x ) # == GS_TRANSCENDENTAL + assert guess_solve_strategy( 2*cos(x) - y, x ) # == GS_TRANSCENDENTAL + assert guess_solve_strategy( + exp(x) + exp(-x) - y, x ) # == GS_TRANSCENDENTAL + assert guess_solve_strategy(3**x - 10, x) # == GS_TRANSCENDENTAL + assert guess_solve_strategy(-3**x + 10, x) # == GS_TRANSCENDENTAL + + assert guess_solve_strategy(a*x**b - y, x) # == GS_TRANSCENDENTAL + + +def test_solve_args(): + # equation container, issue 5113 + ans = {x: -3, y: 1} + eqs = (x + 5*y - 2, -3*x + 6*y - 15) + assert all(solve(container(eqs), x, y) == ans for container in + (tuple, list, set, frozenset)) + assert solve(Tuple(*eqs), x, y) == ans + # implicit symbol to solve for + assert set(solve(x**2 - 4)) == {S(2), -S(2)} + assert solve([x + y - 3, x - y - 5]) == {x: 4, y: -1} + assert solve(x - exp(x), x, implicit=True) == [exp(x)] + # no symbol to solve for + assert solve(42) == solve(42, x) == [] + assert solve([1, 2]) == [] + assert solve([sqrt(2)],[x]) == [] + # duplicate symbols raises + raises(ValueError, lambda: solve((x - 3, y + 2), x, y, x)) + raises(ValueError, lambda: solve(x, x, x)) + # no error in exclude + assert solve(x, x, exclude=[y, y]) == [0] + # duplicate symbols raises + raises(ValueError, lambda: solve((x - 3, y + 2), x, y, x)) + raises(ValueError, lambda: solve(x, x, x)) + # no error in exclude + assert solve(x, x, exclude=[y, y]) == [0] + # unordered symbols + # only 1 + assert solve(y - 3, {y}) == [3] + # more than 1 + assert solve(y - 3, {x, y}) == [{y: 3}] + # multiple symbols: take the first linear solution+ + # - return as tuple with values for all requested symbols + assert solve(x + y - 3, [x, y]) == [(3 - y, y)] + # - unless dict is True + assert solve(x + y - 3, [x, y], dict=True) == [{x: 3 - y}] + # - or no symbols are given + assert solve(x + y - 3) == [{x: 3 - y}] + # multiple symbols might represent an undetermined coefficients system + assert solve(a + b*x - 2, [a, b]) == {a: 2, b: 0} + assert solve((a + b)*x + b - c, [a, b]) == {a: -c, b: c} + eq = a*x**2 + b*x + c - ((x - h)**2 + 4*p*k)/4/p + # - check that flags are obeyed + sol = solve(eq, [h, p, k], exclude=[a, b, c]) + assert sol == {h: -b/(2*a), k: (4*a*c - b**2)/(4*a), p: 1/(4*a)} + assert solve(eq, [h, p, k], dict=True) == [sol] + assert solve(eq, [h, p, k], set=True) == \ + ([h, p, k], {(-b/(2*a), 1/(4*a), (4*a*c - b**2)/(4*a))}) + # issue 23889 - polysys not simplified + assert solve(eq, [h, p, k], exclude=[a, b, c], simplify=False) == \ + {h: -b/(2*a), k: (4*a*c - b**2)/(4*a), p: 1/(4*a)} + # but this only happens when system has a single solution + args = (a + b)*x - b**2 + 2, a, b + assert solve(*args) == [((b**2 - b*x - 2)/x, b)] + # and if the system has a solution; the following doesn't so + # an algebraic solution is returned + assert solve(a*x + b**2/(x + 4) - 3*x - 4/x, a, b, dict=True) == \ + [{a: (-b**2*x + 3*x**3 + 12*x**2 + 4*x + 16)/(x**2*(x + 4))}] + # failed single equation + assert solve(1/(1/x - y + exp(y))) == [] + raises( + NotImplementedError, lambda: solve(exp(x) + sin(x) + exp(y) + sin(y))) + # failed system + # -- when no symbols given, 1 fails + assert solve([y, exp(x) + x]) == [{x: -LambertW(1), y: 0}] + # both fail + assert solve( + (exp(x) - x, exp(y) - y)) == [{x: -LambertW(-1), y: -LambertW(-1)}] + # -- when symbols given + assert solve([y, exp(x) + x], x, y) == [(-LambertW(1), 0)] + # symbol is a number + assert solve(x**2 - pi, pi) == [x**2] + # no equations + assert solve([], [x]) == [] + # nonlinear system + assert solve((x**2 - 4, y - 2), x, y) == [(-2, 2), (2, 2)] + assert solve((x**2 - 4, y - 2), y, x) == [(2, -2), (2, 2)] + assert solve((x**2 - 4 + z, y - 2 - z), a, z, y, x, set=True + ) == ([a, z, y, x], { + (a, z, z + 2, -sqrt(4 - z)), + (a, z, z + 2, sqrt(4 - z))}) + # overdetermined system + # - nonlinear + assert solve([(x + y)**2 - 4, x + y - 2]) == [{x: -y + 2}] + # - linear + assert solve((x + y - 2, 2*x + 2*y - 4)) == {x: -y + 2} + # When one or more args are Boolean + assert solve(Eq(x**2, 0.0)) == [0.0] # issue 19048 + assert solve([True, Eq(x, 0)], [x], dict=True) == [{x: 0}] + assert solve([Eq(x, x), Eq(x, 0), Eq(x, x+1)], [x], dict=True) == [] + assert not solve([Eq(x, x+1), x < 2], x) + assert solve([Eq(x, 0), x+1<2]) == Eq(x, 0) + assert solve([Eq(x, x), Eq(x, x+1)], x) == [] + assert solve(True, x) == [] + assert solve([x - 1, False], [x], set=True) == ([], set()) + assert solve([-y*(x + y - 1)/2, (y - 1)/x/y + 1/y], + set=True, check=False) == ([x, y], {(1 - y, y), (x, 0)}) + # ordering should be canonical, fastest to order by keys instead + # of by size + assert list(solve((y - 1, x - sqrt(3)*z)).keys()) == [x, y] + # as set always returns as symbols, set even if no solution + assert solve([x - 1, x], (y, x), set=True) == ([y, x], set()) + assert solve([x - 1, x], {y, x}, set=True) == ([x, y], set()) + + +def test_solve_polynomial1(): + assert solve(3*x - 2, x) == [Rational(2, 3)] + assert solve(Eq(3*x, 2), x) == [Rational(2, 3)] + + assert set(solve(x**2 - 1, x)) == {-S.One, S.One} + assert set(solve(Eq(x**2, 1), x)) == {-S.One, S.One} + + assert solve(x - y**3, x) == [y**3] + rx = root(x, 3) + assert solve(x - y**3, y) == [ + rx, -rx/2 - sqrt(3)*I*rx/2, -rx/2 + sqrt(3)*I*rx/2] + a11, a12, a21, a22, b1, b2 = symbols('a11,a12,a21,a22,b1,b2') + + assert solve([a11*x + a12*y - b1, a21*x + a22*y - b2], x, y) == \ + { + x: (a22*b1 - a12*b2)/(a11*a22 - a12*a21), + y: (a11*b2 - a21*b1)/(a11*a22 - a12*a21), + } + + solution = {x: S.Zero, y: S.Zero} + + assert solve((x - y, x + y), x, y ) == solution + assert solve((x - y, x + y), (x, y)) == solution + assert solve((x - y, x + y), [x, y]) == solution + + assert set(solve(x**3 - 15*x - 4, x)) == { + -2 + 3**S.Half, + S(4), + -2 - 3**S.Half + } + + assert set(solve((x**2 - 1)**2 - a, x)) == \ + {sqrt(1 + sqrt(a)), -sqrt(1 + sqrt(a)), + sqrt(1 - sqrt(a)), -sqrt(1 - sqrt(a))} + + +def test_solve_polynomial2(): + assert solve(4, x) == [] + + +def test_solve_polynomial_cv_1a(): + """ + Test for solving on equations that can be converted to a polynomial equation + using the change of variable y -> x**Rational(p, q) + """ + assert solve( sqrt(x) - 1, x) == [1] + assert solve( sqrt(x) - 2, x) == [4] + assert solve( x**Rational(1, 4) - 2, x) == [16] + assert solve( x**Rational(1, 3) - 3, x) == [27] + assert solve(sqrt(x) + x**Rational(1, 3) + x**Rational(1, 4), x) == [0] + + +def test_solve_polynomial_cv_1b(): + assert set(solve(4*x*(1 - a*sqrt(x)), x)) == {S.Zero, 1/a**2} + assert set(solve(x*(root(x, 3) - 3), x)) == {S.Zero, S(27)} + + +def test_solve_polynomial_cv_2(): + """ + Test for solving on equations that can be converted to a polynomial equation + multiplying both sides of the equation by x**m + """ + assert solve(x + 1/x - 1, x) in \ + [[ S.Half + I*sqrt(3)/2, S.Half - I*sqrt(3)/2], + [ S.Half - I*sqrt(3)/2, S.Half + I*sqrt(3)/2]] + + +def test_quintics_1(): + f = x**5 - 110*x**3 - 55*x**2 + 2310*x + 979 + s = solve(f, check=False) + for r in s: + res = f.subs(x, r.n()).n() + assert tn(res, 0) + + f = x**5 - 15*x**3 - 5*x**2 + 10*x + 20 + s = solve(f) + for r in s: + assert r.func == CRootOf + + # if one uses solve to get the roots of a polynomial that has a CRootOf + # solution, make sure that the use of nfloat during the solve process + # doesn't fail. Note: if you want numerical solutions to a polynomial + # it is *much* faster to use nroots to get them than to solve the + # equation only to get RootOf solutions which are then numerically + # evaluated. So for eq = x**5 + 3*x + 7 do Poly(eq).nroots() rather + # than [i.n() for i in solve(eq)] to get the numerical roots of eq. + assert nfloat(solve(x**5 + 3*x**3 + 7)[0], exponent=False) == \ + CRootOf(x**5 + 3*x**3 + 7, 0).n() + + +def test_quintics_2(): + f = x**5 + 15*x + 12 + s = solve(f, check=False) + for r in s: + res = f.subs(x, r.n()).n() + assert tn(res, 0) + + f = x**5 - 15*x**3 - 5*x**2 + 10*x + 20 + s = solve(f) + for r in s: + assert r.func == CRootOf + + assert solve(x**5 - 6*x**3 - 6*x**2 + x - 6) == [ + CRootOf(x**5 - 6*x**3 - 6*x**2 + x - 6, 0), + CRootOf(x**5 - 6*x**3 - 6*x**2 + x - 6, 1), + CRootOf(x**5 - 6*x**3 - 6*x**2 + x - 6, 2), + CRootOf(x**5 - 6*x**3 - 6*x**2 + x - 6, 3), + CRootOf(x**5 - 6*x**3 - 6*x**2 + x - 6, 4)] + +def test_quintics_3(): + y = x**5 + x**3 - 2**Rational(1, 3) + assert solve(y) == solve(-y) == [] + + +def test_highorder_poly(): + # just testing that the uniq generator is unpacked + sol = solve(x**6 - 2*x + 2) + assert all(isinstance(i, CRootOf) for i in sol) and len(sol) == 6 + + +def test_solve_rational(): + """Test solve for rational functions""" + assert solve( ( x - y**3 )/( (y**2)*sqrt(1 - y**2) ), x) == [y**3] + + +def test_solve_conjugate(): + """Test solve for simple conjugate functions""" + assert solve(conjugate(x) -3 + I) == [3 + I] + + +def test_solve_nonlinear(): + assert solve(x**2 - y**2, x, y, dict=True) == [{x: -y}, {x: y}] + assert solve(x**2 - y**2/exp(x), y, x, dict=True) == [{y: -x*sqrt(exp(x))}, + {y: x*sqrt(exp(x))}] + + +def test_issue_8666(): + x = symbols('x') + assert solve(Eq(x**2 - 1/(x**2 - 4), 4 - 1/(x**2 - 4)), x) == [] + assert solve(Eq(x + 1/x, 1/x), x) == [] + + +def test_issue_7228(): + assert solve(4**(2*(x**2) + 2*x) - 8, x) == [Rational(-3, 2), S.Half] + + +def test_issue_7190(): + assert solve(log(x-3) + log(x+3), x) == [sqrt(10)] + + +def test_issue_21004(): + x = symbols('x') + f = x/sqrt(x**2+1) + f_diff = f.diff(x) + assert solve(f_diff, x) == [] + + +def test_issue_24650(): + x = symbols('x') + r = solve(Eq(Piecewise((x, Eq(x, 0) | (x > 1))), 0)) + assert r == [0] + r = checksol(Eq(Piecewise((x, Eq(x, 0) | (x > 1))), 0), x, sol=0) + assert r is True + + +def test_linear_system(): + x, y, z, t, n = symbols('x, y, z, t, n') + + assert solve([x - 1, x - y, x - 2*y, y - 1], [x, y]) == [] + + assert solve([x - 1, x - y, x - 2*y, x - 1], [x, y]) == [] + assert solve([x - 1, x - 1, x - y, x - 2*y], [x, y]) == [] + + assert solve([x + 5*y - 2, -3*x + 6*y - 15], x, y) == {x: -3, y: 1} + + M = Matrix([[0, 0, n*(n + 1), (n + 1)**2, 0], + [n + 1, n + 1, -2*n - 1, -(n + 1), 0], + [-1, 0, 1, 0, 0]]) + + assert solve_linear_system(M, x, y, z, t) == \ + {x: t*(-n-1)/n, y: 0, z: t*(-n-1)/n} + + assert solve([x + y + z + t, -z - t], x, y, z, t) == {x: -y, z: -t} + + +@XFAIL +def test_linear_system_xfail(): + # https://github.com/sympy/sympy/issues/6420 + M = Matrix([[0, 15.0, 10.0, 700.0], + [1, 1, 1, 100.0], + [0, 10.0, 5.0, 200.0], + [-5.0, 0, 0, 0 ]]) + + assert solve_linear_system(M, x, y, z) == {x: 0, y: -60.0, z: 160.0} + + +def test_linear_system_function(): + a = Function('a') + assert solve([a(0, 0) + a(0, 1) + a(1, 0) + a(1, 1), -a(1, 0) - a(1, 1)], + a(0, 0), a(0, 1), a(1, 0), a(1, 1)) == {a(1, 0): -a(1, 1), a(0, 0): -a(0, 1)} + + +def test_linear_system_symbols_doesnt_hang_1(): + + def _mk_eqs(wy): + # Equations for fitting a wy*2 - 1 degree polynomial between two points, + # at end points derivatives are known up to order: wy - 1 + order = 2*wy - 1 + x, x0, x1 = symbols('x, x0, x1', real=True) + y0s = symbols('y0_:{}'.format(wy), real=True) + y1s = symbols('y1_:{}'.format(wy), real=True) + c = symbols('c_:{}'.format(order+1), real=True) + + expr = sum(coeff*x**o for o, coeff in enumerate(c)) + eqs = [] + for i in range(wy): + eqs.append(expr.diff(x, i).subs({x: x0}) - y0s[i]) + eqs.append(expr.diff(x, i).subs({x: x1}) - y1s[i]) + return eqs, c + + # + # The purpose of this test is just to see that these calls don't hang. The + # expressions returned are complicated so are not included here. Testing + # their correctness takes longer than solving the system. + # + + for n in range(1, 7+1): + eqs, c = _mk_eqs(n) + solve(eqs, c) + + +def test_linear_system_symbols_doesnt_hang_2(): + + M = Matrix([ + [66, 24, 39, 50, 88, 40, 37, 96, 16, 65, 31, 11, 37, 72, 16, 19, 55, 37, 28, 76], + [10, 93, 34, 98, 59, 44, 67, 74, 74, 94, 71, 61, 60, 23, 6, 2, 57, 8, 29, 78], + [19, 91, 57, 13, 64, 65, 24, 53, 77, 34, 85, 58, 87, 39, 39, 7, 36, 67, 91, 3], + [74, 70, 15, 53, 68, 43, 86, 83, 81, 72, 25, 46, 67, 17, 59, 25, 78, 39, 63, 6], + [69, 40, 67, 21, 67, 40, 17, 13, 93, 44, 46, 89, 62, 31, 30, 38, 18, 20, 12, 81], + [50, 22, 74, 76, 34, 45, 19, 76, 28, 28, 11, 99, 97, 82, 8, 46, 99, 57, 68, 35], + [58, 18, 45, 88, 10, 64, 9, 34, 90, 82, 17, 41, 43, 81, 45, 83, 22, 88, 24, 39], + [42, 21, 70, 68, 6, 33, 64, 81, 83, 15, 86, 75, 86, 17, 77, 34, 62, 72, 20, 24], + [ 7, 8, 2, 72, 71, 52, 96, 5, 32, 51, 31, 36, 79, 88, 25, 77, 29, 26, 33, 13], + [19, 31, 30, 85, 81, 39, 63, 28, 19, 12, 16, 49, 37, 66, 38, 13, 3, 71, 61, 51], + [29, 82, 80, 49, 26, 85, 1, 37, 2, 74, 54, 82, 26, 47, 54, 9, 35, 0, 99, 40], + [15, 49, 82, 91, 93, 57, 45, 25, 45, 97, 15, 98, 48, 52, 66, 24, 62, 54, 97, 37], + [62, 23, 73, 53, 52, 86, 28, 38, 0, 74, 92, 38, 97, 70, 71, 29, 26, 90, 67, 45], + [ 2, 32, 23, 24, 71, 37, 25, 71, 5, 41, 97, 65, 93, 13, 65, 45, 25, 88, 69, 50], + [40, 56, 1, 29, 79, 98, 79, 62, 37, 28, 45, 47, 3, 1, 32, 74, 98, 35, 84, 32], + [33, 15, 87, 79, 65, 9, 14, 63, 24, 19, 46, 28, 74, 20, 29, 96, 84, 91, 93, 1], + [97, 18, 12, 52, 1, 2, 50, 14, 52, 76, 19, 82, 41, 73, 51, 79, 13, 3, 82, 96], + [40, 28, 52, 10, 10, 71, 56, 78, 82, 5, 29, 48, 1, 26, 16, 18, 50, 76, 86, 52], + [38, 89, 83, 43, 29, 52, 90, 77, 57, 0, 67, 20, 81, 88, 48, 96, 88, 58, 14, 3]]) + + syms = x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,x16,x17,x18 = symbols('x:19') + + sol = { + x0: -S(1967374186044955317099186851240896179)/3166636564687820453598895768302256588, + x1: -S(84268280268757263347292368432053826)/791659141171955113399723942075564147, + x2: -S(229962957341664730974463872411844965)/1583318282343910226799447884151128294, + x3: S(990156781744251750886760432229180537)/6333273129375640907197791536604513176, + x4: -S(2169830351210066092046760299593096265)/18999819388126922721593374609813539528, + x5: S(4680868883477577389628494526618745355)/9499909694063461360796687304906769764, + x6: -S(1590820774344371990683178396480879213)/3166636564687820453598895768302256588, + x7: -S(54104723404825537735226491634383072)/339282489073695048599881689460956063, + x8: S(3182076494196560075964847771774733847)/6333273129375640907197791536604513176, + x9: -S(10870817431029210431989147852497539675)/18999819388126922721593374609813539528, + x10: -S(13118019242576506476316318268573312603)/18999819388126922721593374609813539528, + x11: -S(5173852969886775824855781403820641259)/4749954847031730680398343652453384882, + x12: S(4261112042731942783763341580651820563)/4749954847031730680398343652453384882, + x13: -S(821833082694661608993818117038209051)/6333273129375640907197791536604513176, + x14: S(906881575107250690508618713632090559)/904753304196520129599684505229216168, + x15: -S(732162528717458388995329317371283987)/6333273129375640907197791536604513176, + x16: S(4524215476705983545537087360959896817)/9499909694063461360796687304906769764, + x17: -S(3898571347562055611881270844646055217)/6333273129375640907197791536604513176, + x18: S(7513502486176995632751685137907442269)/18999819388126922721593374609813539528 + } + + eqs = list(M * Matrix(syms + (1,))) + assert solve(eqs, syms) == sol + + y = Symbol('y') + eqs = list(y * M * Matrix(syms + (1,))) + assert solve(eqs, syms) == sol + + +def test_linear_systemLU(): + n = Symbol('n') + + M = Matrix([[1, 2, 0, 1], [1, 3, 2*n, 1], [4, -1, n**2, 1]]) + + assert solve_linear_system_LU(M, [x, y, z]) == {z: -3/(n**2 + 18*n), + x: 1 - 12*n/(n**2 + 18*n), + y: 6*n/(n**2 + 18*n)} + +# Note: multiple solutions exist for some of these equations, so the tests +# should be expected to break if the implementation of the solver changes +# in such a way that a different branch is chosen + +@slow +def test_solve_transcendental(): + from sympy.abc import a, b + + assert solve(exp(x) - 3, x) == [log(3)] + assert set(solve((a*x + b)*(exp(x) - 3), x)) == {-b/a, log(3)} + assert solve(cos(x) - y, x) == [-acos(y) + 2*pi, acos(y)] + assert solve(2*cos(x) - y, x) == [-acos(y/2) + 2*pi, acos(y/2)] + assert solve(Eq(cos(x), sin(x)), x) == [pi/4] + + assert set(solve(exp(x) + exp(-x) - y, x)) in [{ + log(y/2 - sqrt(y**2 - 4)/2), + log(y/2 + sqrt(y**2 - 4)/2), + }, { + log(y - sqrt(y**2 - 4)) - log(2), + log(y + sqrt(y**2 - 4)) - log(2)}, + { + log(y/2 - sqrt((y - 2)*(y + 2))/2), + log(y/2 + sqrt((y - 2)*(y + 2))/2)}] + assert solve(exp(x) - 3, x) == [log(3)] + assert solve(Eq(exp(x), 3), x) == [log(3)] + assert solve(log(x) - 3, x) == [exp(3)] + assert solve(sqrt(3*x) - 4, x) == [Rational(16, 3)] + assert solve(3**(x + 2), x) == [] + assert solve(3**(2 - x), x) == [] + assert solve(x + 2**x, x) == [-LambertW(log(2))/log(2)] + assert solve(2*x + 5 + log(3*x - 2), x) == \ + [Rational(2, 3) + LambertW(2*exp(Rational(-19, 3))/3)/2] + assert solve(3*x + log(4*x), x) == [LambertW(Rational(3, 4))/3] + assert set(solve((2*x + 8)*(8 + exp(x)), x)) == {S(-4), log(8) + pi*I} + eq = 2*exp(3*x + 4) - 3 + ans = solve(eq, x) # this generated a failure in flatten + assert len(ans) == 3 and all(eq.subs(x, a).n(chop=True) == 0 for a in ans) + assert solve(2*log(3*x + 4) - 3, x) == [(exp(Rational(3, 2)) - 4)/3] + assert solve(exp(x) + 1, x) == [pi*I] + + eq = 2*(3*x + 4)**5 - 6*7**(3*x + 9) + result = solve(eq, x) + x0 = -log(2401) + x1 = 3**Rational(1, 5) + x2 = log(7**(7*x1/20)) + x3 = sqrt(2) + x4 = sqrt(5) + x5 = x3*sqrt(x4 - 5) + x6 = x4 + 1 + x7 = 1/(3*log(7)) + x8 = -x4 + x9 = x3*sqrt(x8 - 5) + x10 = x8 + 1 + ans = [x7*(x0 - 5*LambertW(x2*(-x5 + x6))), + x7*(x0 - 5*LambertW(x2*(x5 + x6))), + x7*(x0 - 5*LambertW(x2*(x10 - x9))), + x7*(x0 - 5*LambertW(x2*(x10 + x9))), + x7*(x0 - 5*LambertW(-log(7**(7*x1/5))))] + assert result == ans, result + # it works if expanded, too + assert solve(eq.expand(), x) == result + + assert solve(z*cos(x) - y, x) == [-acos(y/z) + 2*pi, acos(y/z)] + assert solve(z*cos(2*x) - y, x) == [-acos(y/z)/2 + pi, acos(y/z)/2] + assert solve(z*cos(sin(x)) - y, x) == [ + pi - asin(acos(y/z)), asin(acos(y/z) - 2*pi) + pi, + -asin(acos(y/z) - 2*pi), asin(acos(y/z))] + + assert solve(z*cos(x), x) == [pi/2, pi*Rational(3, 2)] + + # issue 4508 + assert solve(y - b*x/(a + x), x) in [[-a*y/(y - b)], [a*y/(b - y)]] + assert solve(y - b*exp(a/x), x) == [a/log(y/b)] + # issue 4507 + assert solve(y - b/(1 + a*x), x) in [[(b - y)/(a*y)], [-((y - b)/(a*y))]] + # issue 4506 + assert solve(y - a*x**b, x) == [(y/a)**(1/b)] + # issue 4505 + assert solve(z**x - y, x) == [log(y)/log(z)] + # issue 4504 + assert solve(2**x - 10, x) == [1 + log(5)/log(2)] + # issue 6744 + assert solve(x*y) == [{x: 0}, {y: 0}] + assert solve([x*y]) == [{x: 0}, {y: 0}] + assert solve(x**y - 1) == [{x: 1}, {y: 0}] + assert solve([x**y - 1]) == [{x: 1}, {y: 0}] + assert solve(x*y*(x**2 - y**2)) == [{x: 0}, {x: -y}, {x: y}, {y: 0}] + assert solve([x*y*(x**2 - y**2)]) == [{x: 0}, {x: -y}, {x: y}, {y: 0}] + # issue 4739 + assert solve(exp(log(5)*x) - 2**x, x) == [0] + # issue 14791 + assert solve(exp(log(5)*x) - exp(log(2)*x), x) == [0] + f = Function('f') + assert solve(y*f(log(5)*x) - y*f(log(2)*x), x) == [0] + assert solve(f(x) - f(0), x) == [0] + assert solve(f(x) - f(2 - x), x) == [1] + raises(NotImplementedError, lambda: solve(f(x, y) - f(1, 2), x)) + raises(NotImplementedError, lambda: solve(f(x, y) - f(2 - x, 2), x)) + raises(ValueError, lambda: solve(f(x, y) - f(1 - x), x)) + raises(ValueError, lambda: solve(f(x, y) - f(1), x)) + + # misc + # make sure that the right variables is picked up in tsolve + # shouldn't generate a GeneratorsNeeded error in _tsolve when the NaN is generated + # for eq_down. Actual answers, as determined numerically are approx. +/- 0.83 + raises(NotImplementedError, lambda: + solve(sinh(x)*sinh(sinh(x)) + cosh(x)*cosh(sinh(x)) - 3)) + + # watch out for recursive loop in tsolve + raises(NotImplementedError, lambda: solve((x + 2)**y*x - 3, x)) + + # issue 7245 + assert solve(sin(sqrt(x))) == [0, pi**2] + + # issue 7602 + a, b = symbols('a, b', real=True, negative=False) + assert str(solve(Eq(a, 0.5 - cos(pi*b)/2), b)) == \ + '[2.0 - 0.318309886183791*acos(1.0 - 2.0*a), 0.318309886183791*acos(1.0 - 2.0*a)]' + + # issue 15325 + assert solve(y**(1/x) - z, x) == [log(y)/log(z)] + + # issue 25685 (basic trig identities should give simple solutions) + for yi in [cos(2*x),sin(2*x),cos(x - pi/3)]: + sol = solve([cos(x) - S(3)/5, yi - y]) + assert (sol[0][y] + sol[1][y]).is_Rational, (yi,sol) + # don't allow massive expansion + assert solve(cos(1000*x) - S.Half) == [pi/3000, pi/600] + assert solve(cos(x - 1000*y) - 1, x) == [1000*y, 1000*y + 2*pi] + assert solve(cos(x + y + z) - 1, x) == [-y - z, -y - z + 2*pi] + + # issue 26008 + assert solve(sin(x + pi/6)) == [-pi/6, 5*pi/6] + + +def test_solve_for_functions_derivatives(): + t = Symbol('t') + x = Function('x')(t) + y = Function('y')(t) + a11, a12, a21, a22, b1, b2 = symbols('a11,a12,a21,a22,b1,b2') + + soln = solve([a11*x + a12*y - b1, a21*x + a22*y - b2], x, y) + assert soln == { + x: (a22*b1 - a12*b2)/(a11*a22 - a12*a21), + y: (a11*b2 - a21*b1)/(a11*a22 - a12*a21), + } + + assert solve(x - 1, x) == [1] + assert solve(3*x - 2, x) == [Rational(2, 3)] + + soln = solve([a11*x.diff(t) + a12*y.diff(t) - b1, a21*x.diff(t) + + a22*y.diff(t) - b2], x.diff(t), y.diff(t)) + assert soln == { y.diff(t): (a11*b2 - a21*b1)/(a11*a22 - a12*a21), + x.diff(t): (a22*b1 - a12*b2)/(a11*a22 - a12*a21) } + + assert solve(x.diff(t) - 1, x.diff(t)) == [1] + assert solve(3*x.diff(t) - 2, x.diff(t)) == [Rational(2, 3)] + + eqns = {3*x - 1, 2*y - 4} + assert solve(eqns, {x, y}) == { x: Rational(1, 3), y: 2 } + x = Symbol('x') + f = Function('f') + F = x**2 + f(x)**2 - 4*x - 1 + assert solve(F.diff(x), diff(f(x), x)) == [(-x + 2)/f(x)] + + # Mixed cased with a Symbol and a Function + x = Symbol('x') + y = Function('y')(t) + + soln = solve([a11*x + a12*y.diff(t) - b1, a21*x + + a22*y.diff(t) - b2], x, y.diff(t)) + assert soln == { y.diff(t): (a11*b2 - a21*b1)/(a11*a22 - a12*a21), + x: (a22*b1 - a12*b2)/(a11*a22 - a12*a21) } + + # issue 13263 + x = Symbol('x') + f = Function('f') + soln = solve([f(x).diff(x) + f(x).diff(x, 2) - 1, f(x).diff(x) - f(x).diff(x, 2)], + f(x).diff(x), f(x).diff(x, 2)) + assert soln == { f(x).diff(x, 2): S(1)/2, f(x).diff(x): S(1)/2 } + + soln = solve([f(x).diff(x, 2) + f(x).diff(x, 3) - 1, 1 - f(x).diff(x, 2) - + f(x).diff(x, 3), 1 - f(x).diff(x,3)], f(x).diff(x, 2), f(x).diff(x, 3)) + assert soln == { f(x).diff(x, 2): 0, f(x).diff(x, 3): 1 } + + +def test_issue_3725(): + f = Function('f') + F = x**2 + f(x)**2 - 4*x - 1 + e = F.diff(x) + assert solve(e, f(x).diff(x)) in [[(2 - x)/f(x)], [-((x - 2)/f(x))]] + + +def test_solve_Matrix(): + # https://github.com/sympy/sympy/issues/3870 + a, b, c, d = symbols('a b c d') + A = Matrix(2, 2, [a, b, c, d]) + B = Matrix(2, 2, [0, 2, -3, 0]) + C = Matrix(2, 2, [1, 2, 3, 4]) + + assert solve(A*B - C, [a, b, c, d]) == {a: 1, b: Rational(-1, 3), c: 2, d: -1} + assert solve([A*B - C], [a, b, c, d]) == {a: 1, b: Rational(-1, 3), c: 2, d: -1} + assert solve(Eq(A*B, C), [a, b, c, d]) == {a: 1, b: Rational(-1, 3), c: 2, d: -1} + + assert solve([A*B - B*A], [a, b, c, d]) == {a: d, b: Rational(-2, 3)*c} + assert solve([A*C - C*A], [a, b, c, d]) == {a: d - c, b: Rational(2, 3)*c} + assert solve([A*B - B*A, A*C - C*A], [a, b, c, d]) == {a: d, b: 0, c: 0} + + assert solve([Eq(A*B, B*A)], [a, b, c, d]) == {a: d, b: Rational(-2, 3)*c} + assert solve([Eq(A*C, C*A)], [a, b, c, d]) == {a: d - c, b: Rational(2, 3)*c} + assert solve([Eq(A*B, B*A), Eq(A*C, C*A)], [a, b, c, d]) == {a: d, b: 0, c: 0} + + # https://github.com/sympy/sympy/issues/27854 + m, n = symbols("m n") + A = MatrixSymbol("A", m, n) + x = MatrixSymbol("x", n, 1) + b = MatrixSymbol('b', m, 1) + r = A * x - b + f = r.T * r + grad_f = f.diff(x) + raises(ValueError, lambda: solve(grad_f, x)) + + +def test_solve_linear(): + w = Wild('w') + assert solve_linear(x, x) == (0, 1) + assert solve_linear(x, exclude=[x]) == (0, 1) + assert solve_linear(x, symbols=[w]) == (0, 1) + assert solve_linear(x, y - 2*x) in [(x, y/3), (y, 3*x)] + assert solve_linear(x, y - 2*x, exclude=[x]) == (y, 3*x) + assert solve_linear(3*x - y, 0) in [(x, y/3), (y, 3*x)] + assert solve_linear(3*x - y, 0, [x]) == (x, y/3) + assert solve_linear(3*x - y, 0, [y]) == (y, 3*x) + assert solve_linear(x**2/y, 1) == (y, x**2) + assert solve_linear(w, x) in [(w, x), (x, w)] + assert solve_linear(cos(x)**2 + sin(x)**2 + 2 + y) == \ + (y, -2 - cos(x)**2 - sin(x)**2) + assert solve_linear(cos(x)**2 + sin(x)**2 + 2 + y, symbols=[x]) == (0, 1) + assert solve_linear(Eq(x, 3)) == (x, 3) + assert solve_linear(1/(1/x - 2)) == (0, 0) + assert solve_linear((x + 1)*exp(-x), symbols=[x]) == (x, -1) + assert solve_linear((x + 1)*exp(x), symbols=[x]) == ((x + 1)*exp(x), 1) + assert solve_linear(x*exp(-x**2), symbols=[x]) == (x, 0) + assert solve_linear(0**x - 1) == (0**x - 1, 1) + assert solve_linear(1 + 1/(x - 1)) == (x, 0) + eq = y*cos(x)**2 + y*sin(x)**2 - y # = y*(1 - 1) = 0 + assert solve_linear(eq) == (0, 1) + eq = cos(x)**2 + sin(x)**2 # = 1 + assert solve_linear(eq) == (0, 1) + raises(ValueError, lambda: solve_linear(Eq(x, 3), 3)) + + +def test_solve_undetermined_coeffs(): + assert solve_undetermined_coeffs( + a*x**2 + b*x**2 + b*x + 2*c*x + c + 1, [a, b, c], x + ) == {a: -2, b: 2, c: -1} + # Test that rational functions work + assert solve_undetermined_coeffs(a/x + b/(x + 1) + - (2*x + 1)/(x**2 + x), [a, b], x) == {a: 1, b: 1} + # Test cancellation in rational functions + assert solve_undetermined_coeffs( + ((c + 1)*a*x**2 + (c + 1)*b*x**2 + + (c + 1)*b*x + (c + 1)*2*c*x + (c + 1)**2)/(c + 1), + [a, b, c], x) == \ + {a: -2, b: 2, c: -1} + # multivariate + X, Y, Z = y, x**y, y*x**y + eq = a*X + b*Y + c*Z - X - 2*Y - 3*Z + coeffs = a, b, c + syms = x, y + assert solve_undetermined_coeffs(eq, coeffs) == { + a: 1, b: 2, c: 3} + assert solve_undetermined_coeffs(eq, coeffs, syms) == { + a: 1, b: 2, c: 3} + assert solve_undetermined_coeffs(eq, coeffs, *syms) == { + a: 1, b: 2, c: 3} + # check output format + assert solve_undetermined_coeffs(a*x + a - 2, [a]) == [] + assert solve_undetermined_coeffs(a**2*x - 4*x, [a]) == [ + {a: -2}, {a: 2}] + assert solve_undetermined_coeffs(0, [a]) == [] + assert solve_undetermined_coeffs(0, [a], dict=True) == [] + assert solve_undetermined_coeffs(0, [a], set=True) == ([], {}) + assert solve_undetermined_coeffs(1, [a]) == [] + abeq = a*x - 2*x + b - 3 + s = {b, a} + assert solve_undetermined_coeffs(abeq, s, x) == {a: 2, b: 3} + assert solve_undetermined_coeffs(abeq, s, x, set=True) == ([a, b], {(2, 3)}) + assert solve_undetermined_coeffs(sin(a*x) - sin(2*x), (a,)) is None + assert solve_undetermined_coeffs(a*x + b*x - 2*x, (a, b)) == {a: 2 - b} + + +def test_solve_inequalities(): + x = Symbol('x') + sol = And(S.Zero < x, x < oo) + assert solve(x + 1 > 1) == sol + assert solve([x + 1 > 1]) == sol + assert solve([x + 1 > 1], x) == sol + assert solve([x + 1 > 1], [x]) == sol + + system = [Lt(x**2 - 2, 0), Gt(x**2 - 1, 0)] + assert solve(system) == \ + And(Or(And(Lt(-sqrt(2), x), Lt(x, -1)), + And(Lt(1, x), Lt(x, sqrt(2)))), Eq(0, 0)) + + x = Symbol('x', real=True) + system = [Lt(x**2 - 2, 0), Gt(x**2 - 1, 0)] + assert solve(system) == \ + Or(And(Lt(-sqrt(2), x), Lt(x, -1)), And(Lt(1, x), Lt(x, sqrt(2)))) + + # issues 6627, 3448 + assert solve((x - 3)/(x - 2) < 0, x) == And(Lt(2, x), Lt(x, 3)) + assert solve(x/(x + 1) > 1, x) == And(Lt(-oo, x), Lt(x, -1)) + + assert solve(sin(x) > S.Half) == And(pi/6 < x, x < pi*Rational(5, 6)) + + assert solve(Eq(False, x < 1)) == (S.One <= x) & (x < oo) + assert solve(Eq(True, x < 1)) == (-oo < x) & (x < 1) + assert solve(Eq(x < 1, False)) == (S.One <= x) & (x < oo) + assert solve(Eq(x < 1, True)) == (-oo < x) & (x < 1) + + assert solve(Eq(False, x)) == False + assert solve(Eq(0, x)) == [0] + assert solve(Eq(True, x)) == True + assert solve(Eq(1, x)) == [1] + assert solve(Eq(False, ~x)) == True + assert solve(Eq(True, ~x)) == False + assert solve(Ne(True, x)) == False + assert solve(Ne(1, x)) == (x > -oo) & (x < oo) & Ne(x, 1) + + +def test_issue_4793(): + assert solve(1/x) == [] + assert solve(x*(1 - 5/x)) == [5] + assert solve(x + sqrt(x) - 2) == [1] + assert solve(-(1 + x)/(2 + x)**2 + 1/(2 + x)) == [] + assert solve(-x**2 - 2*x + (x + 1)**2 - 1) == [] + assert solve((x/(x + 1) + 3)**(-2)) == [] + assert solve(x/sqrt(x**2 + 1), x) == [0] + assert solve(exp(x) - y, x) == [log(y)] + assert solve(exp(x)) == [] + assert solve(x**2 + x + sin(y)**2 + cos(y)**2 - 1, x) in [[0, -1], [-1, 0]] + eq = 4*3**(5*x + 2) - 7 + ans = solve(eq, x) + assert len(ans) == 5 and all(eq.subs(x, a).n(chop=True) == 0 for a in ans) + assert solve(log(x**2) - y**2/exp(x), x, y, set=True) == ( + [x, y], + {(x, sqrt(exp(x) * log(x ** 2))), (x, -sqrt(exp(x) * log(x ** 2)))}) + assert solve(x**2*z**2 - z**2*y**2) == [{x: -y}, {x: y}, {z: 0}] + assert solve((x - 1)/(1 + 1/(x - 1))) == [] + assert solve(x**(y*z) - x, x) == [1] + raises(NotImplementedError, lambda: solve(log(x) - exp(x), x)) + raises(NotImplementedError, lambda: solve(2**x - exp(x) - 3)) + + +def test_PR1964(): + # issue 5171 + assert solve(sqrt(x)) == solve(sqrt(x**3)) == [0] + assert solve(sqrt(x - 1)) == [1] + # issue 4462 + a = Symbol('a') + assert solve(-3*a/sqrt(x), x) == [] + # issue 4486 + assert solve(2*x/(x + 2) - 1, x) == [2] + # issue 4496 + assert set(solve((x**2/(7 - x)).diff(x))) == {S.Zero, S(14)} + # issue 4695 + f = Function('f') + assert solve((3 - 5*x/f(x))*f(x), f(x)) == [x*Rational(5, 3)] + # issue 4497 + assert solve(1/root(5 + x, 5) - 9, x) == [Rational(-295244, 59049)] + + assert solve(sqrt(x) + sqrt(sqrt(x)) - 4) == [(Rational(-1, 2) + sqrt(17)/2)**4] + assert set(solve(Poly(sqrt(exp(x)) + sqrt(exp(-x)) - 4))) in \ + [ + {log((-sqrt(3) + 2)**2), log((sqrt(3) + 2)**2)}, + {2*log(-sqrt(3) + 2), 2*log(sqrt(3) + 2)}, + {log(-4*sqrt(3) + 7), log(4*sqrt(3) + 7)}, + ] + assert set(solve(Poly(exp(x) + exp(-x) - 4))) == \ + {log(-sqrt(3) + 2), log(sqrt(3) + 2)} + assert set(solve(x**y + x**(2*y) - 1, x)) == \ + {(Rational(-1, 2) + sqrt(5)/2)**(1/y), (Rational(-1, 2) - sqrt(5)/2)**(1/y)} + + assert solve(exp(x/y)*exp(-z/y) - 2, y) == [(x - z)/log(2)] + assert solve( + x**z*y**z - 2, z) in [[log(2)/(log(x) + log(y))], [log(2)/(log(x*y))]] + # if you do inversion too soon then multiple roots (as for the following) + # will be missed, e.g. if exp(3*x) = exp(3) -> 3*x = 3 + E = S.Exp1 + assert solve(exp(3*x) - exp(3), x) in [ + [1, log(E*(Rational(-1, 2) - sqrt(3)*I/2)), log(E*(Rational(-1, 2) + sqrt(3)*I/2))], + [1, log(-E/2 - sqrt(3)*E*I/2), log(-E/2 + sqrt(3)*E*I/2)], + ] + + # coverage test + p = Symbol('p', positive=True) + assert solve((1/p + 1)**(p + 1)) == [] + + +def test_issue_5197(): + x = Symbol('x', real=True) + assert solve(x**2 + 1, x) == [] + n = Symbol('n', integer=True, positive=True) + assert solve((n - 1)*(n + 2)*(2*n - 1), n) == [1] + x = Symbol('x', positive=True) + y = Symbol('y') + assert solve([x + 5*y - 2, -3*x + 6*y - 15], x, y) == [] + # not {x: -3, y: 1} b/c x is positive + # The solution following should not contain (-sqrt(2), sqrt(2)) + assert solve([(x + y), 2 - y**2], x, y) == [(sqrt(2), -sqrt(2))] + y = Symbol('y', positive=True) + # The solution following should not contain {y: -x*exp(x/2)} + assert solve(x**2 - y**2/exp(x), y, x, dict=True) == [{y: x*exp(x/2)}] + x, y, z = symbols('x y z', positive=True) + assert solve(z**2*x**2 - z**2*y**2/exp(x), y, x, z, dict=True) == [{y: x*exp(x/2)}] + + +def test_checking(): + assert set( + solve(x*(x - y/x), x, check=False)) == {sqrt(y), S.Zero, -sqrt(y)} + assert set(solve(x*(x - y/x), x, check=True)) == {sqrt(y), -sqrt(y)} + # {x: 0, y: 4} sets denominator to 0 in the following so system should return None + assert solve((1/(1/x + 2), 1/(y - 3) - 1)) == [] + # 0 sets denominator of 1/x to zero so None is returned + assert solve(1/(1/x + 2)) == [] + + +def test_issue_4671_4463_4467(): + assert solve(sqrt(x**2 - 1) - 2) in ([sqrt(5), -sqrt(5)], + [-sqrt(5), sqrt(5)]) + assert solve((2**exp(y**2/x) + 2)/(x**2 + 15), y) == [ + -sqrt(x*log(1 + I*pi/log(2))), sqrt(x*log(1 + I*pi/log(2)))] + + C1, C2 = symbols('C1 C2') + f = Function('f') + assert solve(C1 + C2/x**2 - exp(-f(x)), f(x)) == [log(x**2/(C1*x**2 + C2))] + a = Symbol('a') + E = S.Exp1 + assert solve(1 - log(a + 4*x**2), x) in ( + [-sqrt(-a + E)/2, sqrt(-a + E)/2], + [sqrt(-a + E)/2, -sqrt(-a + E)/2] + ) + assert solve(log(a**(-3) - x**2)/a, x) in ( + [-sqrt(-1 + a**(-3)), sqrt(-1 + a**(-3))], + [sqrt(-1 + a**(-3)), -sqrt(-1 + a**(-3))],) + assert solve(1 - log(a + 4*x**2), x) in ( + [-sqrt(-a + E)/2, sqrt(-a + E)/2], + [sqrt(-a + E)/2, -sqrt(-a + E)/2],) + assert solve((a**2 + 1)*(sin(a*x) + cos(a*x)), x) == [-pi/(4*a)] + assert solve(3 - (sinh(a*x) + cosh(a*x)), x) == [log(3)/a] + assert set(solve(3 - (sinh(a*x) + cosh(a*x)**2), x)) == \ + {log(-2 + sqrt(5))/a, log(-sqrt(2) + 1)/a, + log(-sqrt(5) - 2)/a, log(1 + sqrt(2))/a} + assert solve(atan(x) - 1) == [tan(1)] + + +def test_issue_5132(): + r, t = symbols('r,t') + assert set(solve([r - x**2 - y**2, tan(t) - y/x], [x, y])) == \ + {( + -sqrt(r*cos(t)**2), -1*sqrt(r*cos(t)**2)*tan(t)), + (sqrt(r*cos(t)**2), sqrt(r*cos(t)**2)*tan(t))} + assert solve([exp(x) - sin(y), 1/y - 3], [x, y]) == \ + [(log(sin(Rational(1, 3))), Rational(1, 3))] + assert solve([exp(x) - sin(y), 1/exp(y) - 3], [x, y]) == \ + [(log(-sin(log(3))), -log(3))] + assert set(solve([exp(x) - sin(y), y**2 - 4], [x, y])) == \ + {(log(-sin(2)), -S(2)), (log(sin(2)), S(2))} + eqs = [exp(x)**2 - sin(y) + z**2, 1/exp(y) - 3] + assert solve(eqs, set=True) == \ + ([y, z], { + (-log(3), sqrt(-exp(2*x) - sin(log(3)))), + (-log(3), -sqrt(-exp(2*x) - sin(log(3))))}) + assert solve(eqs, x, z, set=True) == ( + [x, z], + {(x, sqrt(-exp(2*x) + sin(y))), (x, -sqrt(-exp(2*x) + sin(y)))}) + assert set(solve(eqs, x, y)) == \ + { + (log(-sqrt(-z**2 - sin(log(3)))), -log(3)), + (log(-z**2 - sin(log(3)))/2, -log(3))} + assert set(solve(eqs, y, z)) == \ + { + (-log(3), -sqrt(-exp(2*x) - sin(log(3)))), + (-log(3), sqrt(-exp(2*x) - sin(log(3))))} + eqs = [exp(x)**2 - sin(y) + z, 1/exp(y) - 3] + assert solve(eqs, set=True) == ([y, z], { + (-log(3), -exp(2*x) - sin(log(3)))}) + assert solve(eqs, x, z, set=True) == ( + [x, z], {(x, -exp(2*x) + sin(y))}) + assert set(solve(eqs, x, y)) == { + (log(-sqrt(-z - sin(log(3)))), -log(3)), + (log(-z - sin(log(3)))/2, -log(3))} + assert solve(eqs, z, y) == \ + [(-exp(2*x) - sin(log(3)), -log(3))] + assert solve((sqrt(x**2 + y**2) - sqrt(10), x + y - 4), set=True) == ( + [x, y], {(S.One, S(3)), (S(3), S.One)}) + assert set(solve((sqrt(x**2 + y**2) - sqrt(10), x + y - 4), x, y)) == \ + {(S.One, S(3)), (S(3), S.One)} + + +def test_issue_5335(): + lam, a0, conc = symbols('lam a0 conc') + a = 0.005 + b = 0.743436700916726 + eqs = [lam + 2*y - a0*(1 - x/2)*x - a*x/2*x, + a0*(1 - x/2)*x - 1*y - b*y, + x + y - conc] + sym = [x, y, a0] + # there are 4 solutions obtained manually but only two are valid + assert len(solve(eqs, sym, manual=True, minimal=True)) == 2 + assert len(solve(eqs, sym)) == 2 # cf below with rational=False + + +@SKIP("Hangs") +def _test_issue_5335_float(): + # gives ZeroDivisionError: polynomial division + lam, a0, conc = symbols('lam a0 conc') + a = 0.005 + b = 0.743436700916726 + eqs = [lam + 2*y - a0*(1 - x/2)*x - a*x/2*x, + a0*(1 - x/2)*x - 1*y - b*y, + x + y - conc] + sym = [x, y, a0] + assert len(solve(eqs, sym, rational=False)) == 2 + + +def test_issue_5767(): + assert set(solve([x**2 + y + 4], [x])) == \ + {(-sqrt(-y - 4),), (sqrt(-y - 4),)} + + +def _make_example_24609(): + D, R, H, B_g, V, D_c = symbols("D, R, H, B_g, V, D_c", real=True, positive=True) + Sigma_f, Sigma_a, nu = symbols("Sigma_f, Sigma_a, nu", real=True, positive=True) + x = symbols("x", real=True, positive=True) + eq = ( + 2**(S(2)/3)*pi**(S(2)/3)*D_c*(S(231361)/10000 + pi**2/x**2) + /(6*V**(S(2)/3)*x**(S(1)/3)) + - 2**(S(2)/3)*pi**(S(8)/3)*D_c/(2*V**(S(2)/3)*x**(S(7)/3)) + ) + expected = 100*sqrt(2)*pi/481 + return eq, expected, x + + +def test_issue_24609(): + # https://github.com/sympy/sympy/issues/24609 + eq, expected, x = _make_example_24609() + assert solve(eq, x, simplify=True) == [expected] + [solapprox] = solve(eq.n(), x) + assert abs(solapprox - expected.n()) < 1e-14 + + +@XFAIL +def test_issue_24609_xfail(): + # + # This returns 5 solutions when it should be 1 (with x positive). + # Simplification reveals all solutions to be equivalent. It is expected + # that solve without simplify=True returns duplicate solutions in some + # cases but the core of this equation is a simple quadratic that can easily + # be solved without introducing any redundant solutions: + # + # >>> print(factor_terms(eq.as_numer_denom()[0])) + # 2**(2/3)*pi**(2/3)*D_c*V**(2/3)*x**(7/3)*(231361*x**2 - 20000*pi**2) + # + eq, expected, x = _make_example_24609() + assert len(solve(eq, x)) == [expected] + # + # We do not want to pass this test just by using simplify so if the above + # passes then uncomment the additional test below: + # + # assert len(solve(eq, x, simplify=False)) == 1 + + +def test_polysys(): + assert set(solve([x**2 + 2/y - 2, x + y - 3], [x, y])) == \ + {(S.One, S(2)), (1 + sqrt(5), 2 - sqrt(5)), + (1 - sqrt(5), 2 + sqrt(5))} + assert solve([x**2 + y - 2, x**2 + y]) == [] + # the ordering should be whatever the user requested + assert solve([x**2 + y - 3, x - y - 4], (x, y)) != solve([x**2 + + y - 3, x - y - 4], (y, x)) + + +@slow +def test_unrad1(): + raises(NotImplementedError, lambda: + unrad(sqrt(x) + sqrt(x + 1) + sqrt(1 - sqrt(x)) + 3)) + raises(NotImplementedError, lambda: + unrad(sqrt(x) + (x + 1)**Rational(1, 3) + 2*sqrt(y))) + + s = symbols('s', cls=Dummy) + + # checkers to deal with possibility of answer coming + # back with a sign change (cf issue 5203) + def check(rv, ans): + assert bool(rv[1]) == bool(ans[1]) + if ans[1]: + return s_check(rv, ans) + e = rv[0].expand() + a = ans[0].expand() + return e in [a, -a] and rv[1] == ans[1] + + def s_check(rv, ans): + # get the dummy + rv = list(rv) + d = rv[0].atoms(Dummy) + reps = list(zip(d, [s]*len(d))) + # replace s with this dummy + rv = (rv[0].subs(reps).expand(), [rv[1][0].subs(reps), rv[1][1].subs(reps)]) + ans = (ans[0].subs(reps).expand(), [ans[1][0].subs(reps), ans[1][1].subs(reps)]) + return str(rv[0]) in [str(ans[0]), str(-ans[0])] and \ + str(rv[1]) == str(ans[1]) + + assert unrad(1) is None + assert check(unrad(sqrt(x)), + (x, [])) + assert check(unrad(sqrt(x) + 1), + (x - 1, [])) + assert check(unrad(sqrt(x) + root(x, 3) + 2), + (s**3 + s**2 + 2, [s, s**6 - x])) + assert check(unrad(sqrt(x)*root(x, 3) + 2), + (x**5 - 64, [])) + assert check(unrad(sqrt(x) + (x + 1)**Rational(1, 3)), + (x**3 - (x + 1)**2, [])) + assert check(unrad(sqrt(x) + sqrt(x + 1) + sqrt(2*x)), + (-2*sqrt(2)*x - 2*x + 1, [])) + assert check(unrad(sqrt(x) + sqrt(x + 1) + 2), + (16*x - 9, [])) + assert check(unrad(sqrt(x) + sqrt(x + 1) + sqrt(1 - x)), + (5*x**2 - 4*x, [])) + assert check(unrad(a*sqrt(x) + b*sqrt(x) + c*sqrt(y) + d*sqrt(y)), + ((a*sqrt(x) + b*sqrt(x))**2 - (c*sqrt(y) + d*sqrt(y))**2, [])) + assert check(unrad(sqrt(x) + sqrt(1 - x)), + (2*x - 1, [])) + assert check(unrad(sqrt(x) + sqrt(1 - x) - 3), + (x**2 - x + 16, [])) + assert check(unrad(sqrt(x) + sqrt(1 - x) + sqrt(2 + x)), + (5*x**2 - 2*x + 1, [])) + assert unrad(sqrt(x) + sqrt(1 - x) + sqrt(2 + x) - 3) in [ + (25*x**4 + 376*x**3 + 1256*x**2 - 2272*x + 784, []), + (25*x**8 - 476*x**6 + 2534*x**4 - 1468*x**2 + 169, [])] + assert unrad(sqrt(x) + sqrt(1 - x) + sqrt(2 + x) - sqrt(1 - 2*x)) == \ + (41*x**4 + 40*x**3 + 232*x**2 - 160*x + 16, []) # orig root at 0.487 + assert check(unrad(sqrt(x) + sqrt(x + 1)), (S.One, [])) + + eq = sqrt(x) + sqrt(x + 1) + sqrt(1 - sqrt(x)) + assert check(unrad(eq), + (16*x**2 - 9*x, [])) + assert set(solve(eq, check=False)) == {S.Zero, Rational(9, 16)} + assert solve(eq) == [] + # but this one really does have those solutions + assert set(solve(sqrt(x) - sqrt(x + 1) + sqrt(1 - sqrt(x)))) == \ + {S.Zero, Rational(9, 16)} + + assert check(unrad(sqrt(x) + root(x + 1, 3) + 2*sqrt(y), y), + (S('2*sqrt(x)*(x + 1)**(1/3) + x - 4*y + (x + 1)**(2/3)'), [])) + assert check(unrad(sqrt(x/(1 - x)) + (x + 1)**Rational(1, 3)), + (x**5 - x**4 - x**3 + 2*x**2 + x - 1, [])) + assert check(unrad(sqrt(x/(1 - x)) + 2*sqrt(y), y), + (4*x*y + x - 4*y, [])) + assert check(unrad(sqrt(x)*sqrt(1 - x) + 2, x), + (x**2 - x + 4, [])) + + # http://tutorial.math.lamar.edu/ + # Classes/Alg/SolveRadicalEqns.aspx#Solve_Rad_Ex2_a + assert solve(Eq(x, sqrt(x + 6))) == [3] + assert solve(Eq(x + sqrt(x - 4), 4)) == [4] + assert solve(Eq(1, x + sqrt(2*x - 3))) == [] + assert set(solve(Eq(sqrt(5*x + 6) - 2, x))) == {-S.One, S(2)} + assert set(solve(Eq(sqrt(2*x - 1) - sqrt(x - 4), 2))) == {S(5), S(13)} + assert solve(Eq(sqrt(x + 7) + 2, sqrt(3 - x))) == [-6] + # http://www.purplemath.com/modules/solverad.htm + assert solve((2*x - 5)**Rational(1, 3) - 3) == [16] + assert set(solve(x + 1 - root(x**4 + 4*x**3 - x, 4))) == \ + {Rational(-1, 2), Rational(-1, 3)} + assert set(solve(sqrt(2*x**2 - 7) - (3 - x))) == {-S(8), S(2)} + assert solve(sqrt(2*x + 9) - sqrt(x + 1) - sqrt(x + 4)) == [0] + assert solve(sqrt(x + 4) + sqrt(2*x - 1) - 3*sqrt(x - 1)) == [5] + assert solve(sqrt(x)*sqrt(x - 7) - 12) == [16] + assert solve(sqrt(x - 3) + sqrt(x) - 3) == [4] + assert solve(sqrt(9*x**2 + 4) - (3*x + 2)) == [0] + assert solve(sqrt(x) - 2 - 5) == [49] + assert solve(sqrt(x - 3) - sqrt(x) - 3) == [] + assert solve(sqrt(x - 1) - x + 7) == [10] + assert solve(sqrt(x - 2) - 5) == [27] + assert solve(sqrt(17*x - sqrt(x**2 - 5)) - 7) == [3] + assert solve(sqrt(x) - sqrt(x - 1) + sqrt(sqrt(x))) == [] + + # don't posify the expression in unrad and do use _mexpand + z = sqrt(2*x + 1)/sqrt(x) - sqrt(2 + 1/x) + p = posify(z)[0] + assert solve(p) == [] + assert solve(z) == [] + assert solve(z + 6*I) == [Rational(-1, 11)] + assert solve(p + 6*I) == [] + # issue 8622 + assert unrad(root(x + 1, 5) - root(x, 3)) == ( + -(x**5 - x**3 - 3*x**2 - 3*x - 1), []) + # issue #8679 + assert check(unrad(x + root(x, 3) + root(x, 3)**2 + sqrt(y), x), + (s**3 + s**2 + s + sqrt(y), [s, s**3 - x])) + + # for coverage + assert check(unrad(sqrt(x) + root(x, 3) + y), + (s**3 + s**2 + y, [s, s**6 - x])) + assert solve(sqrt(x) + root(x, 3) - 2) == [1] + raises(NotImplementedError, lambda: + solve(sqrt(x) + root(x, 3) + root(x + 1, 5) - 2)) + # fails through a different code path + raises(NotImplementedError, lambda: solve(-sqrt(2) + cosh(x)/x)) + # unrad some + assert solve(sqrt(x + root(x, 3))+root(x - y, 5), y) == [ + x + (x**Rational(1, 3) + x)**Rational(5, 2)] + assert check(unrad(sqrt(x) - root(x + 1, 3)*sqrt(x + 2) + 2), + (s**10 + 8*s**8 + 24*s**6 - 12*s**5 - 22*s**4 - 160*s**3 - 212*s**2 - + 192*s - 56, [s, s**2 - x])) + e = root(x + 1, 3) + root(x, 3) + assert unrad(e) == (2*x + 1, []) + eq = (sqrt(x) + sqrt(x + 1) + sqrt(1 - x) - 6*sqrt(5)/5) + assert check(unrad(eq), + (15625*x**4 + 173000*x**3 + 355600*x**2 - 817920*x + 331776, [])) + assert check(unrad(root(x, 4) + root(x, 4)**3 - 1), + (s**3 + s - 1, [s, s**4 - x])) + assert check(unrad(root(x, 2) + root(x, 2)**3 - 1), + (x**3 + 2*x**2 + x - 1, [])) + assert unrad(x**0.5) is None + assert check(unrad(t + root(x + y, 5) + root(x + y, 5)**3), + (s**3 + s + t, [s, s**5 - x - y])) + assert check(unrad(x + root(x + y, 5) + root(x + y, 5)**3, y), + (s**3 + s + x, [s, s**5 - x - y])) + assert check(unrad(x + root(x + y, 5) + root(x + y, 5)**3, x), + (s**5 + s**3 + s - y, [s, s**5 - x - y])) + assert check(unrad(root(x - 1, 3) + root(x + 1, 5) + root(2, 5)), + (s**5 + 5*2**Rational(1, 5)*s**4 + s**3 + 10*2**Rational(2, 5)*s**3 + + 10*2**Rational(3, 5)*s**2 + 5*2**Rational(4, 5)*s + 4, [s, s**3 - x + 1])) + raises(NotImplementedError, lambda: + unrad((root(x, 2) + root(x, 3) + root(x, 4)).subs(x, x**5 - x + 1))) + + # the simplify flag should be reset to False for unrad results; + # if it's not then this next test will take a long time + assert solve(root(x, 3) + root(x, 5) - 2) == [1] + eq = (sqrt(x) + sqrt(x + 1) + sqrt(1 - x) - 6*sqrt(5)/5) + assert check(unrad(eq), + ((5*x - 4)*(3125*x**3 + 37100*x**2 + 100800*x - 82944), [])) + ans = S(''' + [4/5, -1484/375 + 172564/(140625*(114*sqrt(12657)/78125 + + 12459439/52734375)**(1/3)) + + 4*(114*sqrt(12657)/78125 + 12459439/52734375)**(1/3)]''') + assert solve(eq) == ans + # duplicate radical handling + assert check(unrad(sqrt(x + root(x + 1, 3)) - root(x + 1, 3) - 2), + (s**3 - s**2 - 3*s - 5, [s, s**3 - x - 1])) + # cov post-processing + e = root(x**2 + 1, 3) - root(x**2 - 1, 5) - 2 + assert check(unrad(e), + (s**5 - 10*s**4 + 39*s**3 - 80*s**2 + 80*s - 30, + [s, s**3 - x**2 - 1])) + + e = sqrt(x + root(x + 1, 2)) - root(x + 1, 3) - 2 + assert check(unrad(e), + (s**6 - 2*s**5 - 7*s**4 - 3*s**3 + 26*s**2 + 40*s + 25, + [s, s**3 - x - 1])) + assert check(unrad(e, _reverse=True), + (s**6 - 14*s**5 + 73*s**4 - 187*s**3 + 276*s**2 - 228*s + 89, + [s, s**2 - x - sqrt(x + 1)])) + # this one needs r0, r1 reversal to work + assert check(unrad(sqrt(x + sqrt(root(x, 3) - 1)) - root(x, 6) - 2), + (s**12 - 2*s**8 - 8*s**7 - 8*s**6 + s**4 + 8*s**3 + 23*s**2 + + 32*s + 17, [s, s**6 - x])) + + # why does this pass + assert unrad(root(cosh(x), 3)/x*root(x + 1, 5) - 1) == ( + -(x**15 - x**3*cosh(x)**5 - 3*x**2*cosh(x)**5 - 3*x*cosh(x)**5 + - cosh(x)**5), []) + # and this fail? + #assert unrad(sqrt(cosh(x)/x) + root(x + 1, 3)*sqrt(x) - 1) == ( + # -s**6 + 6*s**5 - 15*s**4 + 20*s**3 - 15*s**2 + 6*s + x**5 + + # 2*x**4 + x**3 - 1, [s, s**2 - cosh(x)/x]) + + # watch for symbols in exponents + assert unrad(S('(x+y)**(2*y/3) + (x+y)**(1/3) + 1')) is None + assert check(unrad(S('(x+y)**(2*y/3) + (x+y)**(1/3) + 1'), x), + (s**(2*y) + s + 1, [s, s**3 - x - y])) + # should _Q be so lenient? + assert unrad(x**(S.Half/y) + y, x) == (x**(1/y) - y**2, []) + + # This tests two things: that if full unrad is attempted and fails + # the solution should still be found; also it tests that the use of + # composite + assert len(solve(sqrt(y)*x + x**3 - 1, x)) == 3 + assert len(solve(-512*y**3 + 1344*(x + 2)**Rational(1, 3)*y**2 - + 1176*(x + 2)**Rational(2, 3)*y - 169*x + 686, y, _unrad=False)) == 3 + + # watch out for when the cov doesn't involve the symbol of interest + eq = S('-x + (7*y/8 - (27*x/2 + 27*sqrt(x**2)/2)**(1/3)/3)**3 - 1') + assert solve(eq, y) == [ + 2**(S(2)/3)*(27*x + 27*sqrt(x**2))**(S(1)/3)*S(4)/21 + (512*x/343 + + S(512)/343)**(S(1)/3)*(-S(1)/2 - sqrt(3)*I/2), 2**(S(2)/3)*(27*x + + 27*sqrt(x**2))**(S(1)/3)*S(4)/21 + (512*x/343 + + S(512)/343)**(S(1)/3)*(-S(1)/2 + sqrt(3)*I/2), 2**(S(2)/3)*(27*x + + 27*sqrt(x**2))**(S(1)/3)*S(4)/21 + (512*x/343 + S(512)/343)**(S(1)/3)] + + eq = root(x + 1, 3) - (root(x, 3) + root(x, 5)) + assert check(unrad(eq), + (3*s**13 + 3*s**11 + s**9 - 1, [s, s**15 - x])) + assert check(unrad(eq - 2), + (3*s**13 + 3*s**11 + 6*s**10 + s**9 + 12*s**8 + 6*s**6 + 12*s**5 + + 12*s**3 + 7, [s, s**15 - x])) + assert check(unrad(root(x, 3) - root(x + 1, 4)/2 + root(x + 2, 3)), + (s*(4096*s**9 + 960*s**8 + 48*s**7 - s**6 - 1728), + [s, s**4 - x - 1])) # orig expr has two real roots: -1, -.389 + assert check(unrad(root(x, 3) + root(x + 1, 4) - root(x + 2, 3)/2), + (343*s**13 + 2904*s**12 + 1344*s**11 + 512*s**10 - 1323*s**9 - + 3024*s**8 - 1728*s**7 + 1701*s**5 + 216*s**4 - 729*s, [s, s**4 - x - + 1])) # orig expr has one real root: -0.048 + assert check(unrad(root(x, 3)/2 - root(x + 1, 4) + root(x + 2, 3)), + (729*s**13 - 216*s**12 + 1728*s**11 - 512*s**10 + 1701*s**9 - + 3024*s**8 + 1344*s**7 + 1323*s**5 - 2904*s**4 + 343*s, [s, s**4 - x - + 1])) # orig expr has 2 real roots: -0.91, -0.15 + assert check(unrad(root(x, 3)/2 - root(x + 1, 4) + root(x + 2, 3) - 2), + (729*s**13 + 1242*s**12 + 18496*s**10 + 129701*s**9 + 388602*s**8 + + 453312*s**7 - 612864*s**6 - 3337173*s**5 - 6332418*s**4 - 7134912*s**3 + - 5064768*s**2 - 2111913*s - 398034, [s, s**4 - x - 1])) + # orig expr has 1 real root: 19.53 + + ans = solve(sqrt(x) + sqrt(x + 1) - + sqrt(1 - x) - sqrt(2 + x)) + assert len(ans) == 1 and NS(ans[0])[:4] == '0.73' + # the fence optimization problem + # https://github.com/sympy/sympy/issues/4793#issuecomment-36994519 + F = Symbol('F') + eq = F - (2*x + 2*y + sqrt(x**2 + y**2)) + ans = F*Rational(2, 7) - sqrt(2)*F/14 + X = solve(eq, x, check=False) + for xi in reversed(X): # reverse since currently, ans is the 2nd one + Y = solve((x*y).subs(x, xi).diff(y), y, simplify=False, check=False) + if any((a - ans).expand().is_zero for a in Y): + break + else: + assert None # no answer was found + assert solve(sqrt(x + 1) + root(x, 3) - 2) == S(''' + [(-11/(9*(47/54 + sqrt(93)/6)**(1/3)) + 1/3 + (47/54 + + sqrt(93)/6)**(1/3))**3]''') + assert solve(sqrt(sqrt(x + 1)) + x**Rational(1, 3) - 2) == S(''' + [(-sqrt(-2*(-1/16 + sqrt(6913)/16)**(1/3) + 6/(-1/16 + + sqrt(6913)/16)**(1/3) + 17/2 + 121/(4*sqrt(-6/(-1/16 + + sqrt(6913)/16)**(1/3) + 2*(-1/16 + sqrt(6913)/16)**(1/3) + 17/4)))/2 + + sqrt(-6/(-1/16 + sqrt(6913)/16)**(1/3) + 2*(-1/16 + + sqrt(6913)/16)**(1/3) + 17/4)/2 + 9/4)**3]''') + assert solve(sqrt(x) + root(sqrt(x) + 1, 3) - 2) == S(''' + [(-(81/2 + 3*sqrt(741)/2)**(1/3)/3 + (81/2 + 3*sqrt(741)/2)**(-1/3) + + 2)**2]''') + eq = S(''' + -x + (1/2 - sqrt(3)*I/2)*(3*x**3/2 - x*(3*x**2 - 34)/2 + sqrt((-3*x**3 + + x*(3*x**2 - 34) + 90)**2/4 - 39304/27) - 45)**(1/3) + 34/(3*(1/2 - + sqrt(3)*I/2)*(3*x**3/2 - x*(3*x**2 - 34)/2 + sqrt((-3*x**3 + x*(3*x**2 + - 34) + 90)**2/4 - 39304/27) - 45)**(1/3))''') + assert check(unrad(eq), + (s*-(-s**6 + sqrt(3)*s**6*I - 153*2**Rational(2, 3)*3**Rational(1, 3)*s**4 + + 51*12**Rational(1, 3)*s**4 - 102*2**Rational(2, 3)*3**Rational(5, 6)*s**4*I - 1620*s**3 + + 1620*sqrt(3)*s**3*I + 13872*18**Rational(1, 3)*s**2 - 471648 + + 471648*sqrt(3)*I), [s, s**3 - 306*x - sqrt(3)*sqrt(31212*x**2 - + 165240*x + 61484) + 810])) + + assert solve(eq) == [] # not other code errors + eq = root(x, 3) - root(y, 3) + root(x, 5) + assert check(unrad(eq), + (s**15 + 3*s**13 + 3*s**11 + s**9 - y, [s, s**15 - x])) + eq = root(x, 3) + root(y, 3) + root(x*y, 4) + assert check(unrad(eq), + (s*y*(-s**12 - 3*s**11*y - 3*s**10*y**2 - s**9*y**3 - + 3*s**8*y**2 + 21*s**7*y**3 - 3*s**6*y**4 - 3*s**4*y**4 - + 3*s**3*y**5 - y**6), [s, s**4 - x*y])) + raises(NotImplementedError, + lambda: unrad(root(x, 3) + root(y, 3) + root(x*y, 5))) + + # Test unrad with an Equality + eq = Eq(-x**(S(1)/5) + x**(S(1)/3), -3**(S(1)/3) - (-1)**(S(3)/5)*3**(S(1)/5)) + assert check(unrad(eq), + (-s**5 + s**3 - 3**(S(1)/3) - (-1)**(S(3)/5)*3**(S(1)/5), [s, s**15 - x])) + + # make sure buried radicals are exposed + s = sqrt(x) - 1 + assert unrad(s**2 - s**3) == (x**3 - 6*x**2 + 9*x - 4, []) + # make sure numerators which are already polynomial are rejected + assert unrad((x/(x + 1) + 3)**(-2), x) is None + + # https://github.com/sympy/sympy/issues/23707 + eq = sqrt(x - y)*exp(t*sqrt(x - y)) - exp(t*sqrt(x - y)) + assert solve(eq, y) == [x - 1] + assert unrad(eq) is None + + +@slow +def test_unrad_slow(): + # this has roots with multiplicity > 1; there should be no + # repeats in roots obtained, however + eq = (sqrt(1 + sqrt(1 - 4*x**2)) - x*(1 + sqrt(1 + 2*sqrt(1 - 4*x**2)))) + assert solve(eq) == [S.Half] + + +@XFAIL +def test_unrad_fail(): + # this only works if we check real_root(eq.subs(x, Rational(1, 3))) + # but checksol doesn't work like that + assert solve(root(x**3 - 3*x**2, 3) + 1 - x) == [Rational(1, 3)] + assert solve(root(x + 1, 3) + root(x**2 - 2, 5) + 1) == [ + -1, -1 + CRootOf(x**5 + x**4 + 5*x**3 + 8*x**2 + 10*x + 5, 0)**3] + + +def test_checksol(): + x, y, r, t = symbols('x, y, r, t') + eq = r - x**2 - y**2 + dict_var_soln = {y: - sqrt(r) / sqrt(tan(t)**2 + 1), + x: -sqrt(r)*tan(t)/sqrt(tan(t)**2 + 1)} + assert checksol(eq, dict_var_soln) == True + assert checksol(Eq(x, False), {x: False}) is True + assert checksol(Ne(x, False), {x: False}) is False + assert checksol(Eq(x < 1, True), {x: 0}) is True + assert checksol(Eq(x < 1, True), {x: 1}) is False + assert checksol(Eq(x < 1, False), {x: 1}) is True + assert checksol(Eq(x < 1, False), {x: 0}) is False + assert checksol(Eq(x + 1, x**2 + 1), {x: 1}) is True + assert checksol([x - 1, x**2 - 1], x, 1) is True + assert checksol([x - 1, x**2 - 2], x, 1) is False + assert checksol(Poly(x**2 - 1), x, 1) is True + assert checksol(0, {}) is True + assert checksol([1e-10, x - 2], x, 2) is False + assert checksol([0.5, 0, x], x, 0) is False + assert checksol(y, x, 2) is False + assert checksol(x+1e-10, x, 0, numerical=True) is True + assert checksol(x+1e-10, x, 0, numerical=False) is False + assert checksol(exp(92*x), {x: log(sqrt(2)/2)}) is False + assert checksol(exp(92*x), {x: log(sqrt(2)/2) + I*pi}) is False + assert checksol(1/x**5, x, 1000) is False + raises(ValueError, lambda: checksol(x, 1)) + raises(ValueError, lambda: checksol([], x, 1)) + + +def test__invert(): + assert _invert(x - 2) == (2, x) + assert _invert(2) == (2, 0) + assert _invert(exp(1/x) - 3, x) == (1/log(3), x) + assert _invert(exp(1/x + a/x) - 3, x) == ((a + 1)/log(3), x) + assert _invert(a, x) == (a, 0) + + +def test_issue_4463(): + assert solve(-a*x + 2*x*log(x), x) == [exp(a/2)] + assert solve(x**x) == [] + assert solve(x**x - 2) == [exp(LambertW(log(2)))] + assert solve(((x - 3)*(x - 2))**((x - 3)*(x - 4))) == [2] + +@slow +def test_issue_5114_solvers(): + a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r = symbols('a:r') + + # there is no 'a' in the equation set but this is how the + # problem was originally posed + syms = a, b, c, f, h, k, n + eqs = [b + r/d - c/d, + c*(1/d + 1/e + 1/g) - f/g - r/d, + f*(1/g + 1/i + 1/j) - c/g - h/i, + h*(1/i + 1/l + 1/m) - f/i - k/m, + k*(1/m + 1/o + 1/p) - h/m - n/p, + n*(1/p + 1/q) - k/p] + assert len(solve(eqs, syms, manual=True, check=False, simplify=False)) == 1 + + +def test_issue_5849(): + # + # XXX: This system does not have a solution for most values of the + # parameters. Generally solve returns the empty set for systems that are + # generically inconsistent. + # + I1, I2, I3, I4, I5, I6 = symbols('I1:7') + dI1, dI4, dQ2, dQ4, Q2, Q4 = symbols('dI1,dI4,dQ2,dQ4,Q2,Q4') + + e = ( + I1 - I2 - I3, + I3 - I4 - I5, + I4 + I5 - I6, + -I1 + I2 + I6, + -2*I1 - 2*I3 - 2*I5 - 3*I6 - dI1/2 + 12, + -I4 + dQ4, + -I2 + dQ2, + 2*I3 + 2*I5 + 3*I6 - Q2, + I4 - 2*I5 + 2*Q4 + dI4 + ) + + ans = [{ + I1: I2 + I3, + dI1: -4*I2 - 8*I3 - 4*I5 - 6*I6 + 24, + I4: I3 - I5, + dQ4: I3 - I5, + Q4: -I3/2 + 3*I5/2 - dI4/2, + dQ2: I2, + Q2: 2*I3 + 2*I5 + 3*I6}] + + v = I1, I4, Q2, Q4, dI1, dI4, dQ2, dQ4 + assert solve(e, *v, manual=True, check=False, dict=True) == ans + assert solve(e, *v, manual=True, check=False) == [ + tuple([a.get(i, i) for i in v]) for a in ans] + assert solve(e, *v, manual=True) == [] + assert solve(e, *v) == [] + + # the matrix solver (tested below) doesn't like this because it produces + # a zero row in the matrix. Is this related to issue 4551? + assert [ei.subs( + ans[0]) for ei in e] == [0, 0, I3 - I6, -I3 + I6, 0, 0, 0, 0, 0] + + +def test_issue_5849_matrix(): + '''Same as test_issue_5849 but solved with the matrix solver. + + A solution only exists if I3 == I6 which is not generically true, + but `solve` does not return conditions under which the solution is + valid, only a solution that is canonical and consistent with the input. + ''' + # a simple example with the same issue + # assert solve([x+y+z, x+y], [x, y]) == {x: y} + # the longer example + I1, I2, I3, I4, I5, I6 = symbols('I1:7') + dI1, dI4, dQ2, dQ4, Q2, Q4 = symbols('dI1,dI4,dQ2,dQ4,Q2,Q4') + + e = ( + I1 - I2 - I3, + I3 - I4 - I5, + I4 + I5 - I6, + -I1 + I2 + I6, + -2*I1 - 2*I3 - 2*I5 - 3*I6 - dI1/2 + 12, + -I4 + dQ4, + -I2 + dQ2, + 2*I3 + 2*I5 + 3*I6 - Q2, + I4 - 2*I5 + 2*Q4 + dI4 + ) + assert solve(e, I1, I4, Q2, Q4, dI1, dI4, dQ2, dQ4) == [] + + +def test_issue_21882(): + + a, b, c, d, f, g, k = unknowns = symbols('a, b, c, d, f, g, k') + + equations = [ + -k*a + b + 5*f/6 + 2*c/9 + 5*d/6 + 4*a/3, + -k*f + 4*f/3 + d/2, + -k*d + f/6 + d, + 13*b/18 + 13*c/18 + 13*a/18, + -k*c + b/2 + 20*c/9 + a, + -k*b + b + c/18 + a/6, + 5*b/3 + c/3 + a, + 2*b/3 + 2*c + 4*a/3, + -g, + ] + + answer = [ + {a: 0, f: 0, b: 0, d: 0, c: 0, g: 0}, + {a: 0, f: -d, b: 0, k: S(5)/6, c: 0, g: 0}, + {a: -2*c, f: 0, b: c, d: 0, k: S(13)/18, g: 0}] + # but not {a: 0, f: 0, b: 0, k: S(3)/2, c: 0, d: 0, g: 0} + # since this is already covered by the first solution + got = solve(equations, unknowns, dict=True) + assert got == answer, (got,answer) + + +def test_issue_5901(): + f, g, h = map(Function, 'fgh') + a = Symbol('a') + D = Derivative(f(x), x) + G = Derivative(g(a), a) + assert solve(f(x) + f(x).diff(x), f(x)) == \ + [-D] + assert solve(f(x) - 3, f(x)) == \ + [3] + assert solve(f(x) - 3*f(x).diff(x), f(x)) == \ + [3*D] + assert solve([f(x) - 3*f(x).diff(x)], f(x)) == \ + {f(x): 3*D} + assert solve([f(x) - 3*f(x).diff(x), f(x)**2 - y + 4], f(x), y) == \ + [(3*D, 9*D**2 + 4)] + assert solve(-f(a)**2*g(a)**2 + f(a)**2*h(a)**2 + g(a).diff(a), + h(a), g(a), set=True) == \ + ([h(a), g(a)], { + (-sqrt(f(a)**2*g(a)**2 - G)/f(a), g(a)), + (sqrt(f(a)**2*g(a)**2 - G)/f(a), g(a))}), solve(-f(a)**2*g(a)**2 + f(a)**2*h(a)**2 + g(a).diff(a), + h(a), g(a), set=True) + args = [[f(x).diff(x, 2)*(f(x) + g(x)), 2 - g(x)**2], f(x), g(x)] + assert solve(*args, set=True)[1] == \ + {(-sqrt(2), sqrt(2)), (sqrt(2), -sqrt(2))} + eqs = [f(x)**2 + g(x) - 2*f(x).diff(x), g(x)**2 - 4] + assert solve(eqs, f(x), g(x), set=True) == \ + ([f(x), g(x)], { + (-sqrt(2*D - 2), S(2)), + (sqrt(2*D - 2), S(2)), + (-sqrt(2*D + 2), -S(2)), + (sqrt(2*D + 2), -S(2))}) + + # the underlying problem was in solve_linear that was not masking off + # anything but a Mul or Add; it now raises an error if it gets anything + # but a symbol and solve handles the substitutions necessary so solve_linear + # won't make this error + raises( + ValueError, lambda: solve_linear(f(x) + f(x).diff(x), symbols=[f(x)])) + assert solve_linear(f(x) + f(x).diff(x), symbols=[x]) == \ + (f(x) + Derivative(f(x), x), 1) + assert solve_linear(f(x) + Integral(x, (x, y)), symbols=[x]) == \ + (f(x) + Integral(x, (x, y)), 1) + assert solve_linear(f(x) + Integral(x, (x, y)) + x, symbols=[x]) == \ + (x + f(x) + Integral(x, (x, y)), 1) + assert solve_linear(f(y) + Integral(x, (x, y)) + x, symbols=[x]) == \ + (x, -f(y) - Integral(x, (x, y))) + assert solve_linear(x - f(x)/a + (f(x) - 1)/a, symbols=[x]) == \ + (x, 1/a) + assert solve_linear(x + Derivative(2*x, x)) == \ + (x, -2) + assert solve_linear(x + Integral(x, y), symbols=[x]) == \ + (x, 0) + assert solve_linear(x + Integral(x, y) - 2, symbols=[x]) == \ + (x, 2/(y + 1)) + + assert set(solve(x + exp(x)**2, exp(x))) == \ + {-sqrt(-x), sqrt(-x)} + assert solve(x + exp(x), x, implicit=True) == \ + [-exp(x)] + assert solve(cos(x) - sin(x), x, implicit=True) == [] + assert solve(x - sin(x), x, implicit=True) == \ + [sin(x)] + assert solve(x**2 + x - 3, x, implicit=True) == \ + [-x**2 + 3] + assert solve(x**2 + x - 3, x**2, implicit=True) == \ + [-x + 3] + + +def test_issue_5912(): + assert set(solve(x**2 - x - 0.1, rational=True)) == \ + {S.Half + sqrt(35)/10, -sqrt(35)/10 + S.Half} + ans = solve(x**2 - x - 0.1, rational=False) + assert len(ans) == 2 and all(a.is_Number for a in ans) + ans = solve(x**2 - x - 0.1) + assert len(ans) == 2 and all(a.is_Number for a in ans) + + +def test_float_handling(): + def test(e1, e2): + return len(e1.atoms(Float)) == len(e2.atoms(Float)) + assert solve(x - 0.5, rational=True)[0].is_Rational + assert solve(x - 0.5, rational=False)[0].is_Float + assert solve(x - S.Half, rational=False)[0].is_Rational + assert solve(x - 0.5, rational=None)[0].is_Float + assert solve(x - S.Half, rational=None)[0].is_Rational + assert test(nfloat(1 + 2*x), 1.0 + 2.0*x) + for contain in [list, tuple, set]: + ans = nfloat(contain([1 + 2*x])) + assert type(ans) is contain and test(list(ans)[0], 1.0 + 2.0*x) + k, v = list(nfloat({2*x: [1 + 2*x]}).items())[0] + assert test(k, 2*x) and test(v[0], 1.0 + 2.0*x) + assert test(nfloat(cos(2*x)), cos(2.0*x)) + assert test(nfloat(3*x**2), 3.0*x**2) + assert test(nfloat(3*x**2, exponent=True), 3.0*x**2.0) + assert test(nfloat(exp(2*x)), exp(2.0*x)) + assert test(nfloat(x/3), x/3.0) + assert test(nfloat(x**4 + 2*x + cos(Rational(1, 3)) + 1), + x**4 + 2.0*x + 1.94495694631474) + # don't call nfloat if there is no solution + tot = 100 + c + z + t + assert solve(((.7 + c)/tot - .6, (.2 + z)/tot - .3, t/tot - .1)) == [] + + +def test_check_assumptions(): + x = symbols('x', positive=True) + assert solve(x**2 - 1) == [1] + + +def test_issue_6056(): + assert solve(tanh(x + 3)*tanh(x - 3) - 1) == [] + assert solve(tanh(x - 1)*tanh(x + 1) + 1) == \ + [I*pi*Rational(-3, 4), -I*pi/4, I*pi/4, I*pi*Rational(3, 4)] + assert solve((tanh(x + 3)*tanh(x - 3) + 1)**2) == \ + [I*pi*Rational(-3, 4), -I*pi/4, I*pi/4, I*pi*Rational(3, 4)] + + +def test_issue_5673(): + eq = -x + exp(exp(LambertW(log(x)))*LambertW(log(x))) + assert checksol(eq, x, 2) is True + assert checksol(eq, x, 2, numerical=False) is None + + +def test_exclude(): + R, C, Ri, Vout, V1, Vminus, Vplus, s = \ + symbols('R, C, Ri, Vout, V1, Vminus, Vplus, s') + Rf = symbols('Rf', positive=True) # to eliminate Rf = 0 soln + eqs = [C*V1*s + Vplus*(-2*C*s - 1/R), + Vminus*(-1/Ri - 1/Rf) + Vout/Rf, + C*Vplus*s + V1*(-C*s - 1/R) + Vout/R, + -Vminus + Vplus] + assert solve(eqs, exclude=s*C*R) == [ + { + Rf: Ri*(C*R*s + 1)**2/(C*R*s), + Vminus: Vplus, + V1: 2*Vplus + Vplus/(C*R*s), + Vout: C*R*Vplus*s + 3*Vplus + Vplus/(C*R*s)}, + { + Vplus: 0, + Vminus: 0, + V1: 0, + Vout: 0}, + ] + + # TODO: Investigate why currently solution [0] is preferred over [1]. + assert solve(eqs, exclude=[Vplus, s, C]) in [[{ + Vminus: Vplus, + V1: Vout/2 + Vplus/2 + sqrt((Vout - 5*Vplus)*(Vout - Vplus))/2, + R: (Vout - 3*Vplus - sqrt(Vout**2 - 6*Vout*Vplus + 5*Vplus**2))/(2*C*Vplus*s), + Rf: Ri*(Vout - Vplus)/Vplus, + }, { + Vminus: Vplus, + V1: Vout/2 + Vplus/2 - sqrt((Vout - 5*Vplus)*(Vout - Vplus))/2, + R: (Vout - 3*Vplus + sqrt(Vout**2 - 6*Vout*Vplus + 5*Vplus**2))/(2*C*Vplus*s), + Rf: Ri*(Vout - Vplus)/Vplus, + }], [{ + Vminus: Vplus, + Vout: (V1**2 - V1*Vplus - Vplus**2)/(V1 - 2*Vplus), + Rf: Ri*(V1 - Vplus)**2/(Vplus*(V1 - 2*Vplus)), + R: Vplus/(C*s*(V1 - 2*Vplus)), + }]] + + +def test_high_order_roots(): + s = x**5 + 4*x**3 + 3*x**2 + Rational(7, 4) + assert set(solve(s)) == set(Poly(s*4, domain='ZZ').all_roots()) + + +def test_minsolve_linear_system(): + pqt = {"quick": True, "particular": True} + pqf = {"quick": False, "particular": True} + assert solve([x + y - 5, 2*x - y - 1], **pqt) == {x: 2, y: 3} + assert solve([x + y - 5, 2*x - y - 1], **pqf) == {x: 2, y: 3} + def count(dic): + return len([x for x in dic.values() if x == 0]) + assert count(solve([x + y + z, y + z + a + t], **pqt)) == 3 + assert count(solve([x + y + z, y + z + a + t], **pqf)) == 3 + assert count(solve([x + y + z, y + z + a], **pqt)) == 1 + assert count(solve([x + y + z, y + z + a], **pqf)) == 2 + # issue 22718 + A = Matrix([ + [ 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0], + [ 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, -1, -1, 0, 0], + [-1, -1, 0, 0, -1, 0, 0, 0, 0, 0, 1, 1, 0, 1], + [ 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, -1, 0, -1, 0], + [-1, 0, -1, 0, 0, -1, 0, 0, 0, 0, 1, 0, 1, 1], + [-1, 0, 0, -1, 0, 0, -1, 0, 0, 0, -1, 0, 0, -1], + [ 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, -1, -1, 0], + [ 0, -1, -1, 0, 0, 0, 0, -1, 0, 0, 0, 1, 1, 1], + [ 0, -1, 0, -1, 0, 0, 0, 0, -1, 0, 0, -1, 0, -1], + [ 0, 0, -1, -1, 0, 0, 0, 0, 0, -1, 0, 0, -1, -1], + [ 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0], + [ 0, 0, 0, 0, -1, -1, 0, -1, 0, 0, 0, 0, 0, 0]]) + v = Matrix(symbols("v:14", integer=True)) + B = Matrix([[2], [-2], [0], [0], [0], [0], [0], [0], [0], + [0], [0], [0]]) + eqs = A@v-B + assert solve(eqs) == [] + assert solve(eqs, particular=True) == [] # assumption violated + assert all(v for v in solve([x + y + z, y + z + a]).values()) + for _q in (True, False): + assert not all(v for v in solve( + [x + y + z, y + z + a], quick=_q, + particular=True).values()) + # raise error if quick used w/o particular=True + raises(ValueError, lambda: solve([x + 1], quick=_q)) + raises(ValueError, lambda: solve([x + 1], quick=_q, particular=False)) + # and give a good error message if someone tries to use + # particular with a single equation + raises(ValueError, lambda: solve(x + 1, particular=True)) + + +def test_real_roots(): + # cf. issue 6650 + x = Symbol('x', real=True) + assert len(solve(x**5 + x**3 + 1)) == 1 + + +def test_issue_6528(): + eqs = [ + 327600995*x**2 - 37869137*x + 1809975124*y**2 - 9998905626, + 895613949*x**2 - 273830224*x*y + 530506983*y**2 - 10000000000] + # two expressions encountered are > 1400 ops long so if this hangs + # it is likely because simplification is being done + assert len(solve(eqs, y, x, check=False)) == 4 + + +def test_overdetermined(): + x = symbols('x', real=True) + eqs = [Abs(4*x - 7) - 5, Abs(3 - 8*x) - 1] + assert solve(eqs, x) == [(S.Half,)] + assert solve(eqs, x, manual=True) == [(S.Half,)] + assert solve(eqs, x, manual=True, check=False) == [(S.Half,), (S(3),)] + + +def test_issue_6605(): + x = symbols('x') + assert solve(4**(x/2) - 2**(x/3)) == [0, 3*I*pi/log(2)] + # while the first one passed, this one failed + x = symbols('x', real=True) + assert solve(5**(x/2) - 2**(x/3)) == [0] + b = sqrt(6)*sqrt(log(2))/sqrt(log(5)) + assert solve(5**(x/2) - 2**(3/x)) == [-b, b] + + +def test__ispow(): + assert _ispow(x**2) + assert not _ispow(x) + assert not _ispow(True) + + +def test_issue_6644(): + eq = -sqrt((m - q)**2 + (-m/(2*q) + S.Half)**2) + sqrt((-m**2/2 - sqrt( + 4*m**4 - 4*m**2 + 8*m + 1)/4 - Rational(1, 4))**2 + (m**2/2 - m - sqrt( + 4*m**4 - 4*m**2 + 8*m + 1)/4 - Rational(1, 4))**2) + sol = solve(eq, q, simplify=False, check=False) + assert len(sol) == 5 + + +def test_issue_6752(): + assert solve([a**2 + a, a - b], [a, b]) == [(-1, -1), (0, 0)] + assert solve([a**2 + a*c, a - b], [a, b]) == [(0, 0), (-c, -c)] + + +def test_issue_6792(): + assert solve(x*(x - 1)**2*(x + 1)*(x**6 - x + 1)) == [ + -1, 0, 1, CRootOf(x**6 - x + 1, 0), CRootOf(x**6 - x + 1, 1), + CRootOf(x**6 - x + 1, 2), CRootOf(x**6 - x + 1, 3), + CRootOf(x**6 - x + 1, 4), CRootOf(x**6 - x + 1, 5)] + + +def test_issues_6819_6820_6821_6248_8692_25777_25779(): + # issue 6821 + x, y = symbols('x y', real=True) + assert solve(abs(x + 3) - 2*abs(x - 3)) == [1, 9] + assert solve([abs(x) - 2, arg(x) - pi], x) == [(-2,)] + assert set(solve(abs(x - 7) - 8)) == {-S.One, S(15)} + + # issue 8692 + assert solve(Eq(Abs(x + 1) + Abs(x**2 - 7), 9), x) == [ + Rational(-1, 2) + sqrt(61)/2, -sqrt(69)/2 + S.Half] + + # issue 7145 + assert solve(2*abs(x) - abs(x - 1)) == [-1, Rational(1, 3)] + + # 25777 + assert solve(abs(x**3 + x + 2)/(x + 1)) == [] + + # 25779 + assert solve(abs(x)) == [0] + assert solve(Eq(abs(x**2 - 2*x), 4), x) == [ + 1 - sqrt(5), 1 + sqrt(5)] + nn = symbols('nn', nonnegative=True) + assert solve(abs(sqrt(nn))) == [0] + nz = symbols('nz', nonzero=True) + assert solve(Eq(Abs(4 + 1 / (4*nz)), 0)) == [-Rational(1, 16)] + + x = symbols('x') + assert solve([re(x) - 1, im(x) - 2], x) == [ + {x: 1 + 2*I, re(x): 1, im(x): 2}] + + # check for 'dict' handling of solution + eq = sqrt(re(x)**2 + im(x)**2) - 3 + assert solve(eq) == solve(eq, x) + + i = symbols('i', imaginary=True) + assert solve(abs(i) - 3) == [-3*I, 3*I] + raises(NotImplementedError, lambda: solve(abs(x) - 3)) + + w = symbols('w', integer=True) + assert solve(2*x**w - 4*y**w, w) == solve((x/y)**w - 2, w) + + x, y = symbols('x y', real=True) + assert solve(x + y*I + 3) == {y: 0, x: -3} + # issue 2642 + assert solve(x*(1 + I)) == [0] + + x, y = symbols('x y', imaginary=True) + assert solve(x + y*I + 3 + 2*I) == {x: -2*I, y: 3*I} + + x = symbols('x', real=True) + assert solve(x + y + 3 + 2*I) == {x: -3, y: -2*I} + + # issue 6248 + f = Function('f') + assert solve(f(x + 1) - f(2*x - 1)) == [2] + assert solve(log(x + 1) - log(2*x - 1)) == [2] + + x = symbols('x') + assert solve(2**x + 4**x) == [I*pi/log(2)] + +def test_issue_17638(): + + assert solve(((2-exp(2*x))*exp(x))/(exp(2*x)+2)**2 > 0, x) == (-oo < x) & (x < log(2)/2) + assert solve(((2-exp(2*x)+2)*exp(x+2))/(exp(x)+2)**2 > 0, x) == (-oo < x) & (x < log(4)/2) + assert solve((exp(x)+2+x**2)*exp(2*x+2)/(exp(x)+2)**2 > 0, x) == (-oo < x) & (x < oo) + + + +def test_issue_14607(): + # issue 14607 + s, tau_c, tau_1, tau_2, phi, K = symbols( + 's, tau_c, tau_1, tau_2, phi, K') + + target = (s**2*tau_1*tau_2 + s*tau_1 + s*tau_2 + 1)/(K*s*(-phi + tau_c)) + + K_C, tau_I, tau_D = symbols('K_C, tau_I, tau_D', + positive=True, nonzero=True) + PID = K_C*(1 + 1/(tau_I*s) + tau_D*s) + + eq = (target - PID).together() + eq *= denom(eq).simplify() + eq = Poly(eq, s) + c = eq.coeffs() + + vars = [K_C, tau_I, tau_D] + s = solve(c, vars, dict=True) + + assert len(s) == 1 + + knownsolution = {K_C: -(tau_1 + tau_2)/(K*(phi - tau_c)), + tau_I: tau_1 + tau_2, + tau_D: tau_1*tau_2/(tau_1 + tau_2)} + + for var in vars: + assert s[0][var].simplify() == knownsolution[var].simplify() + + +def test_lambert_multivariate(): + from sympy.abc import x, y + assert _filtered_gens(Poly(x + 1/x + exp(x) + y), x) == {x, exp(x)} + assert _lambert(x, x) == [] + assert solve((x**2 - 2*x + 1).subs(x, log(x) + 3*x)) == [LambertW(3*S.Exp1)/3] + assert solve((x**2 - 2*x + 1).subs(x, (log(x) + 3*x)**2 - 1)) == \ + [LambertW(3*exp(-sqrt(2)))/3, LambertW(3*exp(sqrt(2)))/3] + assert solve((x**2 - 2*x - 2).subs(x, log(x) + 3*x)) == \ + [LambertW(3*exp(1 - sqrt(3)))/3, LambertW(3*exp(1 + sqrt(3)))/3] + eq = (x*exp(x) - 3).subs(x, x*exp(x)) + assert solve(eq) == [LambertW(3*exp(-LambertW(3)))] + # coverage test + raises(NotImplementedError, lambda: solve(x - sin(x)*log(y - x), x)) + ans = [3, -3*LambertW(-log(3)/3)/log(3)] # 3 and 2.478... + assert solve(x**3 - 3**x, x) == ans + assert set(solve(3*log(x) - x*log(3))) == set(ans) + assert solve(LambertW(2*x) - y, x) == [y*exp(y)/2] + + +@XFAIL +def test_other_lambert(): + assert solve(3*sin(x) - x*sin(3), x) == [3] + assert set(solve(x**a - a**x), x) == { + a, -a*LambertW(-log(a)/a)/log(a)} + + +@slow +def test_lambert_bivariate(): + # tests passing current implementation + assert solve((x**2 + x)*exp(x**2 + x) - 1) == [ + Rational(-1, 2) + sqrt(1 + 4*LambertW(1))/2, + Rational(-1, 2) - sqrt(1 + 4*LambertW(1))/2] + assert solve((x**2 + x)*exp((x**2 + x)*2) - 1) == [ + Rational(-1, 2) + sqrt(1 + 2*LambertW(2))/2, + Rational(-1, 2) - sqrt(1 + 2*LambertW(2))/2] + assert solve(a/x + exp(x/2), x) == [2*LambertW(-a/2)] + assert solve((a/x + exp(x/2)).diff(x), x) == \ + [4*LambertW(-sqrt(2)*sqrt(a)/4), 4*LambertW(sqrt(2)*sqrt(a)/4)] + assert solve((1/x + exp(x/2)).diff(x), x) == \ + [4*LambertW(-sqrt(2)/4), + 4*LambertW(sqrt(2)/4), # nsimplifies as 2*2**(141/299)*3**(206/299)*5**(205/299)*7**(37/299)/21 + 4*LambertW(-sqrt(2)/4, -1)] + assert solve(x*log(x) + 3*x + 1, x) == \ + [exp(-3 + LambertW(-exp(3)))] + assert solve(-x**2 + 2**x, x) == [2, 4, -2*LambertW(log(2)/2)/log(2)] + assert solve(x**2 - 2**x, x) == [2, 4, -2*LambertW(log(2)/2)/log(2)] + ans = solve(3*x + 5 + 2**(-5*x + 3), x) + assert len(ans) == 1 and ans[0].expand() == \ + Rational(-5, 3) + LambertW(-10240*root(2, 3)*log(2)/3)/(5*log(2)) + assert solve(5*x - 1 + 3*exp(2 - 7*x), x) == \ + [Rational(1, 5) + LambertW(-21*exp(Rational(3, 5))/5)/7] + assert solve((log(x) + x).subs(x, x**2 + 1)) == [ + -I*sqrt(-LambertW(1) + 1), sqrt(-1 + LambertW(1))] + # check collection + ax = a**(3*x + 5) + ans = solve(3*log(ax) + b*log(ax) + ax, x) + x0 = 1/log(a) + x1 = sqrt(3)*I + x2 = b + 3 + x3 = x2*LambertW(1/x2)/a**5 + x4 = x3**Rational(1, 3)/2 + assert ans == [ + x0*log(x4*(-x1 - 1)), + x0*log(x4*(x1 - 1)), + x0*log(x3)/3] + x1 = LambertW(Rational(1, 3)) + x2 = a**(-5) + x3 = -3**Rational(1, 3) + x4 = 3**Rational(5, 6)*I + x5 = x1**Rational(1, 3)*x2**Rational(1, 3)/2 + ans = solve(3*log(ax) + ax, x) + assert ans == [ + x0*log(3*x1*x2)/3, + x0*log(x5*(x3 - x4)), + x0*log(x5*(x3 + x4))] + # coverage + p = symbols('p', positive=True) + eq = 4*2**(2*p + 3) - 2*p - 3 + assert _solve_lambert(eq, p, _filtered_gens(Poly(eq), p)) == [ + Rational(-3, 2) - LambertW(-4*log(2))/(2*log(2))] + assert set(solve(3**cos(x) - cos(x)**3)) == { + acos(3), acos(-3*LambertW(-log(3)/3)/log(3))} + # should give only one solution after using `uniq` + assert solve(2*log(x) - 2*log(z) + log(z + log(x) + log(z)), x) == [ + exp(-z + LambertW(2*z**4*exp(2*z))/2)/z] + # cases when p != S.One + # issue 4271 + ans = solve((a/x + exp(x/2)).diff(x, 2), x) + x0 = (-a)**Rational(1, 3) + x1 = sqrt(3)*I + x2 = x0/6 + assert ans == [ + 6*LambertW(x0/3), + 6*LambertW(x2*(-x1 - 1)), + 6*LambertW(x2*(x1 - 1))] + assert solve((1/x + exp(x/2)).diff(x, 2), x) == \ + [6*LambertW(Rational(-1, 3)), 6*LambertW(Rational(1, 6) - sqrt(3)*I/6), \ + 6*LambertW(Rational(1, 6) + sqrt(3)*I/6), 6*LambertW(Rational(-1, 3), -1)] + assert solve(x**2 - y**2/exp(x), x, y, dict=True) == \ + [{x: 2*LambertW(-y/2)}, {x: 2*LambertW(y/2)}] + # this is slow but not exceedingly slow + assert solve((x**3)**(x/2) + pi/2, x) == [ + exp(LambertW(-2*log(2)/3 + 2*log(pi)/3 + I*pi*Rational(2, 3)))] + + # issue 23253 + assert solve((1/log(sqrt(x) + 2)**2 - 1/x)) == [ + (LambertW(-exp(-2), -1) + 2)**2] + assert solve((1/log(1/sqrt(x) + 2)**2 - x)) == [ + (LambertW(-exp(-2), -1) + 2)**-2] + assert solve((1/log(x**2 + 2)**2 - x**-4)) == [ + -I*sqrt(2 - LambertW(exp(2))), + -I*sqrt(LambertW(-exp(-2)) + 2), + sqrt(-2 - LambertW(-exp(-2))), + sqrt(-2 + LambertW(exp(2))), + -sqrt(-2 - LambertW(-exp(-2), -1)), + sqrt(-2 - LambertW(-exp(-2), -1))] + + +def test_rewrite_trig(): + assert solve(sin(x) + tan(x)) == [0, -pi, pi, 2*pi] + assert solve(sin(x) + sec(x)) == [ + -2*atan(Rational(-1, 2) + sqrt(2)*sqrt(1 - sqrt(3)*I)/2 + sqrt(3)*I/2), + 2*atan(S.Half - sqrt(2)*sqrt(1 + sqrt(3)*I)/2 + sqrt(3)*I/2), 2*atan(S.Half + + sqrt(2)*sqrt(1 + sqrt(3)*I)/2 + sqrt(3)*I/2), 2*atan(S.Half - + sqrt(3)*I/2 + sqrt(2)*sqrt(1 - sqrt(3)*I)/2)] + assert solve(sinh(x) + tanh(x)) == [0, I*pi] + + # issue 6157 + assert solve(2*sin(x) - cos(x), x) == [atan(S.Half)] + + +@XFAIL +def test_rewrite_trigh(): + # if this import passes then the test below should also pass + from sympy.functions.elementary.hyperbolic import sech + assert solve(sinh(x) + sech(x)) == [ + 2*atanh(Rational(-1, 2) + sqrt(5)/2 - sqrt(-2*sqrt(5) + 2)/2), + 2*atanh(Rational(-1, 2) + sqrt(5)/2 + sqrt(-2*sqrt(5) + 2)/2), + 2*atanh(-sqrt(5)/2 - S.Half + sqrt(2 + 2*sqrt(5))/2), + 2*atanh(-sqrt(2 + 2*sqrt(5))/2 - sqrt(5)/2 - S.Half)] + + +def test_uselogcombine(): + eq = z - log(x) + log(y/(x*(-1 + y**2/x**2))) + assert solve(eq, x, force=True) == [-sqrt(y*(y - exp(z))), sqrt(y*(y - exp(z)))] + assert solve(log(x + 3) + log(1 + 3/x) - 3) in [ + [-3 + sqrt(-12 + exp(3))*exp(Rational(3, 2))/2 + exp(3)/2, + -sqrt(-12 + exp(3))*exp(Rational(3, 2))/2 - 3 + exp(3)/2], + [-3 + sqrt(-36 + (-exp(3) + 6)**2)/2 + exp(3)/2, + -3 - sqrt(-36 + (-exp(3) + 6)**2)/2 + exp(3)/2], + ] + assert solve(log(exp(2*x) + 1) + log(-tanh(x) + 1) - log(2)) == [] + + +def test_atan2(): + assert solve(atan2(x, 2) - pi/3, x) == [2*sqrt(3)] + + +def test_errorinverses(): + assert solve(erf(x) - y, x) == [erfinv(y)] + assert solve(erfinv(x) - y, x) == [erf(y)] + assert solve(erfc(x) - y, x) == [erfcinv(y)] + assert solve(erfcinv(x) - y, x) == [erfc(y)] + + +def test_issue_2725(): + R = Symbol('R') + eq = sqrt(2)*R*sqrt(1/(R + 1)) + (R + 1)*(sqrt(2)*sqrt(1/(R + 1)) - 1) + sol = solve(eq, R, set=True)[1] + assert sol == {(Rational(5, 3) + (Rational(-1, 2) - sqrt(3)*I/2)*(Rational(251, 27) + + sqrt(111)*I/9)**Rational(1, 3) + 40/(9*((Rational(-1, 2) - sqrt(3)*I/2)*(Rational(251, 27) + + sqrt(111)*I/9)**Rational(1, 3))),), (Rational(5, 3) + 40/(9*(Rational(251, 27) + + sqrt(111)*I/9)**Rational(1, 3)) + (Rational(251, 27) + sqrt(111)*I/9)**Rational(1, 3),)} + + +def test_issue_5114_6611(): + # See that it doesn't hang; this solves in about 2 seconds. + # Also check that the solution is relatively small. + # Note: the system in issue 6611 solves in about 5 seconds and has + # an op-count of 138336 (with simplify=False). + b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r = symbols('b:r') + eqs = Matrix([ + [b - c/d + r/d], [c*(1/g + 1/e + 1/d) - f/g - r/d], + [-c/g + f*(1/j + 1/i + 1/g) - h/i], [-f/i + h*(1/m + 1/l + 1/i) - k/m], + [-h/m + k*(1/p + 1/o + 1/m) - n/p], [-k/p + n*(1/q + 1/p)]]) + v = Matrix([f, h, k, n, b, c]) + ans = solve(list(eqs), list(v), simplify=False) + # If time is taken to simplify then then 2617 below becomes + # 1168 and the time is about 50 seconds instead of 2. + assert sum(s.count_ops() for s in ans.values()) <= 3270 + + +def test_det_quick(): + m = Matrix(3, 3, symbols('a:9')) + assert m.det() == det_quick(m) # calls det_perm + m[0, 0] = 1 + assert m.det() == det_quick(m) # calls det_minor + m = Matrix(3, 3, list(range(9))) + assert m.det() == det_quick(m) # defaults to .det() + # make sure they work with Sparse + s = SparseMatrix(2, 2, (1, 2, 1, 4)) + assert det_perm(s) == det_minor(s) == s.det() + + +def test_real_imag_splitting(): + a, b = symbols('a b', real=True) + assert solve(sqrt(a**2 + b**2) - 3, a) == \ + [-sqrt(-b**2 + 9), sqrt(-b**2 + 9)] + a, b = symbols('a b', imaginary=True) + assert solve(sqrt(a**2 + b**2) - 3, a) == [] + + +def test_issue_7110(): + y = -2*x**3 + 4*x**2 - 2*x + 5 + assert any(ask(Q.real(i)) for i in solve(y)) + + +def test_units(): + assert solve(1/x - 1/(2*cm)) == [2*cm] + + +def test_issue_7547(): + A, B, V = symbols('A,B,V') + eq1 = Eq(630.26*(V - 39.0)*V*(V + 39) - A + B, 0) + eq2 = Eq(B, 1.36*10**8*(V - 39)) + eq3 = Eq(A, 5.75*10**5*V*(V + 39.0)) + sol = Matrix(nsolve(Tuple(eq1, eq2, eq3), [A, B, V], (0, 0, 0))) + assert str(sol) == str(Matrix( + [['4442890172.68209'], + ['4289299466.1432'], + ['70.5389666628177']])) + + +def test_issue_7895(): + r = symbols('r', real=True) + assert solve(sqrt(r) - 2) == [4] + + +def test_issue_2777(): + # the equations represent two circles + x, y = symbols('x y', real=True) + e1, e2 = sqrt(x**2 + y**2) - 10, sqrt(y**2 + (-x + 10)**2) - 3 + a, b = Rational(191, 20), 3*sqrt(391)/20 + ans = [(a, -b), (a, b)] + assert solve((e1, e2), (x, y)) == ans + assert solve((e1, e2/(x - a)), (x, y)) == [] + # make the 2nd circle's radius be -3 + e2 += 6 + assert solve((e1, e2), (x, y)) == [] + assert solve((e1, e2), (x, y), check=False) == ans + + +def test_issue_7322(): + number = 5.62527e-35 + assert solve(x - number, x)[0] == number + + +def test_nsolve(): + raises(ValueError, lambda: nsolve(x, (-1, 1), method='bisect')) + raises(TypeError, lambda: nsolve((x - y + 3,x + y,z - y),(x,y,z),(-50,50))) + raises(TypeError, lambda: nsolve((x + y, x - y), (0, 1))) + raises(TypeError, lambda: nsolve(x < 0.5, x, 1)) + + +@slow +def test_high_order_multivariate(): + assert len(solve(a*x**3 - x + 1, x)) == 3 + assert len(solve(a*x**4 - x + 1, x)) == 4 + assert solve(a*x**5 - x + 1, x) == [] # incomplete solution allowed + raises(NotImplementedError, lambda: + solve(a*x**5 - x + 1, x, incomplete=False)) + + # result checking must always consider the denominator and CRootOf + # must be checked, too + d = x**5 - x + 1 + assert solve(d*(1 + 1/d)) == [CRootOf(d + 1, i) for i in range(5)] + d = x - 1 + assert solve(d*(2 + 1/d)) == [S.Half] + + +def test_base_0_exp_0(): + assert solve(0**x - 1) == [0] + assert solve(0**(x - 2) - 1) == [2] + assert solve(S('x*(1/x**0 - x)', evaluate=False)) == \ + [0, 1] + + +def test__simple_dens(): + assert _simple_dens(1/x**0, [x]) == set() + assert _simple_dens(1/x**y, [x]) == {x**y} + assert _simple_dens(1/root(x, 3), [x]) == {x} + + +def test_issue_8755(): + # This tests two things: that if full unrad is attempted and fails + # the solution should still be found; also it tests the use of + # keyword `composite`. + assert len(solve(sqrt(y)*x + x**3 - 1, x)) == 3 + assert len(solve(-512*y**3 + 1344*(x + 2)**Rational(1, 3)*y**2 - + 1176*(x + 2)**Rational(2, 3)*y - 169*x + 686, y, _unrad=False)) == 3 + + +@slow +def test_issue_8828(): + x1 = 0 + y1 = -620 + r1 = 920 + x2 = 126 + y2 = 276 + x3 = 51 + y3 = 205 + r3 = 104 + v = x, y, z + + f1 = (x - x1)**2 + (y - y1)**2 - (r1 - z)**2 + f2 = (x - x2)**2 + (y - y2)**2 - z**2 + f3 = (x - x3)**2 + (y - y3)**2 - (r3 - z)**2 + F = f1,f2,f3 + + g1 = sqrt((x - x1)**2 + (y - y1)**2) + z - r1 + g2 = f2 + g3 = sqrt((x - x3)**2 + (y - y3)**2) + z - r3 + G = g1,g2,g3 + + A = solve(F, v) + B = solve(G, v) + C = solve(G, v, manual=True) + + p, q, r = [{tuple(i.evalf(2) for i in j) for j in R} for R in [A, B, C]] + assert p == q == r + + +def test_issue_2840_8155(): + # with parameter-free solutions (i.e. no `n`), we want to avoid + # excessive periodic solutions + assert solve(sin(3*x) + sin(6*x)) == [0, -2*pi/9, 2*pi/9] + assert solve(sin(300*x) + sin(600*x)) == [0, -pi/450, pi/450] + assert solve(2*sin(x) - 2*sin(2*x)) == [0, -pi/3, pi/3] + + +def test_issue_9567(): + assert solve(1 + 1/(x - 1)) == [0] + + +def test_issue_11538(): + assert solve(x + E) == [-E] + assert solve(x**2 + E) == [-I*sqrt(E), I*sqrt(E)] + assert solve(x**3 + 2*E) == [ + -cbrt(2 * E), + cbrt(2)*cbrt(E)/2 - cbrt(2)*sqrt(3)*I*cbrt(E)/2, + cbrt(2)*cbrt(E)/2 + cbrt(2)*sqrt(3)*I*cbrt(E)/2] + assert solve([x + 4, y + E], x, y) == {x: -4, y: -E} + assert solve([x**2 + 4, y + E], x, y) == [ + (-2*I, -E), (2*I, -E)] + + e1 = x - y**3 + 4 + e2 = x + y + 4 + 4 * E + assert len(solve([e1, e2], x, y)) == 3 + + +@slow +def test_issue_12114(): + a, b, c, d, e, f, g = symbols('a,b,c,d,e,f,g') + terms = [1 + a*b + d*e, 1 + a*c + d*f, 1 + b*c + e*f, + g - a**2 - d**2, g - b**2 - e**2, g - c**2 - f**2] + sol = solve(terms, [a, b, c, d, e, f, g], dict=True) + s = sqrt(-f**2 - 1) + s2 = sqrt(2 - f**2) + s3 = sqrt(6 - 3*f**2) + s4 = sqrt(3)*f + s5 = sqrt(3)*s2 + assert sol == [ + {a: -s, b: -s, c: -s, d: f, e: f, g: -1}, + {a: s, b: s, c: s, d: f, e: f, g: -1}, + {a: -s4/2 - s2/2, b: s4/2 - s2/2, c: s2, + d: -f/2 + s3/2, e: -f/2 - s5/2, g: 2}, + {a: -s4/2 + s2/2, b: s4/2 + s2/2, c: -s2, + d: -f/2 - s3/2, e: -f/2 + s5/2, g: 2}, + {a: s4/2 - s2/2, b: -s4/2 - s2/2, c: s2, + d: -f/2 - s3/2, e: -f/2 + s5/2, g: 2}, + {a: s4/2 + s2/2, b: -s4/2 + s2/2, c: -s2, + d: -f/2 + s3/2, e: -f/2 - s5/2, g: 2}] + + +def test_inf(): + assert solve(1 - oo*x) == [] + assert solve(oo*x, x) == [] + assert solve(oo*x - oo, x) == [] + + +def test_issue_12448(): + f = Function('f') + fun = [f(i) for i in range(15)] + sym = symbols('x:15') + reps = dict(zip(fun, sym)) + + (x, y, z), c = sym[:3], sym[3:] + ssym = solve([c[4*i]*x + c[4*i + 1]*y + c[4*i + 2]*z + c[4*i + 3] + for i in range(3)], (x, y, z)) + + (x, y, z), c = fun[:3], fun[3:] + sfun = solve([c[4*i]*x + c[4*i + 1]*y + c[4*i + 2]*z + c[4*i + 3] + for i in range(3)], (x, y, z)) + + assert sfun[fun[0]].xreplace(reps).count_ops() == \ + ssym[sym[0]].count_ops() + + +def test_denoms(): + assert denoms(x/2 + 1/y) == {2, y} + assert denoms(x/2 + 1/y, y) == {y} + assert denoms(x/2 + 1/y, [y]) == {y} + assert denoms(1/x + 1/y + 1/z, [x, y]) == {x, y} + assert denoms(1/x + 1/y + 1/z, x, y) == {x, y} + assert denoms(1/x + 1/y + 1/z, {x, y}) == {x, y} + + +def test_issue_12476(): + x0, x1, x2, x3, x4, x5 = symbols('x0 x1 x2 x3 x4 x5') + eqns = [x0**2 - x0, x0*x1 - x1, x0*x2 - x2, x0*x3 - x3, x0*x4 - x4, x0*x5 - x5, + x0*x1 - x1, -x0/3 + x1**2 - 2*x2/3, x1*x2 - x1/3 - x2/3 - x3/3, + x1*x3 - x2/3 - x3/3 - x4/3, x1*x4 - 2*x3/3 - x5/3, x1*x5 - x4, x0*x2 - x2, + x1*x2 - x1/3 - x2/3 - x3/3, -x0/6 - x1/6 + x2**2 - x2/6 - x3/3 - x4/6, + -x1/6 + x2*x3 - x2/3 - x3/6 - x4/6 - x5/6, x2*x4 - x2/3 - x3/3 - x4/3, + x2*x5 - x3, x0*x3 - x3, x1*x3 - x2/3 - x3/3 - x4/3, + -x1/6 + x2*x3 - x2/3 - x3/6 - x4/6 - x5/6, + -x0/6 - x1/6 - x2/6 + x3**2 - x3/3 - x4/6, -x1/3 - x2/3 + x3*x4 - x3/3, + -x2 + x3*x5, x0*x4 - x4, x1*x4 - 2*x3/3 - x5/3, x2*x4 - x2/3 - x3/3 - x4/3, + -x1/3 - x2/3 + x3*x4 - x3/3, -x0/3 - 2*x2/3 + x4**2, -x1 + x4*x5, x0*x5 - x5, + x1*x5 - x4, x2*x5 - x3, -x2 + x3*x5, -x1 + x4*x5, -x0 + x5**2, x0 - 1] + sols = [{x0: 1, x3: Rational(1, 6), x2: Rational(1, 6), x4: Rational(-2, 3), x1: Rational(-2, 3), x5: 1}, + {x0: 1, x3: S.Half, x2: Rational(-1, 2), x4: 0, x1: 0, x5: -1}, + {x0: 1, x3: Rational(-1, 3), x2: Rational(-1, 3), x4: Rational(1, 3), x1: Rational(1, 3), x5: 1}, + {x0: 1, x3: 1, x2: 1, x4: 1, x1: 1, x5: 1}, + {x0: 1, x3: Rational(-1, 3), x2: Rational(1, 3), x4: sqrt(5)/3, x1: -sqrt(5)/3, x5: -1}, + {x0: 1, x3: Rational(-1, 3), x2: Rational(1, 3), x4: -sqrt(5)/3, x1: sqrt(5)/3, x5: -1}] + + assert solve(eqns) == sols + + +def test_issue_13849(): + t = symbols('t') + assert solve((t*(sqrt(5) + sqrt(2)) - sqrt(2), t), t) == [] + + +def test_issue_14860(): + from sympy.physics.units import newton, kilo + assert solve(8*kilo*newton + x + y, x) == [-8000*newton - y] + + +def test_issue_14721(): + k, h, a, b = symbols(':4') + assert solve([ + -1 + (-k + 1)**2/b**2 + (-h - 1)**2/a**2, + -1 + (-k + 1)**2/b**2 + (-h + 1)**2/a**2, + h, k + 2], h, k, a, b) == [ + (0, -2, -b*sqrt(1/(b**2 - 9)), b), + (0, -2, b*sqrt(1/(b**2 - 9)), b)] + assert solve([ + h, h/a + 1/b**2 - 2, -h/2 + 1/b**2 - 2], a, h, b) == [ + (a, 0, -sqrt(2)/2), (a, 0, sqrt(2)/2)] + assert solve((a + b**2 - 1, a + b**2 - 2)) == [] + + +def test_issue_14779(): + x = symbols('x', real=True) + assert solve(sqrt(x**4 - 130*x**2 + 1089) + sqrt(x**4 - 130*x**2 + + 3969) - 96*Abs(x)/x,x) == [sqrt(130)] + + +def test_issue_15307(): + assert solve((y - 2, Mul(x + 3,x - 2, evaluate=False))) == \ + [{x: -3, y: 2}, {x: 2, y: 2}] + assert solve((y - 2, Mul(3, x - 2, evaluate=False))) == \ + {x: 2, y: 2} + assert solve((y - 2, Add(x + 4, x - 2, evaluate=False))) == \ + {x: -1, y: 2} + eq1 = Eq(12513*x + 2*y - 219093, -5726*x - y) + eq2 = Eq(-2*x + 8, 2*x - 40) + assert solve([eq1, eq2]) == {x:12, y:75} + + +def test_issue_15415(): + assert solve(x - 3, x) == [3] + assert solve([x - 3], x) == {x:3} + assert solve(Eq(y + 3*x**2/2, y + 3*x), y) == [] + assert solve([Eq(y + 3*x**2/2, y + 3*x)], y) == [] + assert solve([Eq(y + 3*x**2/2, y + 3*x), Eq(x, 1)], y) == [] + + +@slow +def test_issue_15731(): + # f(x)**g(x)=c + assert solve(Eq((x**2 - 7*x + 11)**(x**2 - 13*x + 42), 1)) == [2, 3, 4, 5, 6, 7] + assert solve((x)**(x + 4) - 4) == [-2] + assert solve((-x)**(-x + 4) - 4) == [2] + assert solve((x**2 - 6)**(x**2 - 2) - 4) == [-2, 2] + assert solve((x**2 - 2*x - 1)**(x**2 - 3) - 1/(1 - 2*sqrt(2))) == [sqrt(2)] + assert solve(x**(x + S.Half) - 4*sqrt(2)) == [S(2)] + assert solve((x**2 + 1)**x - 25) == [2] + assert solve(x**(2/x) - 2) == [2, 4] + assert solve((x/2)**(2/x) - sqrt(2)) == [4, 8] + assert solve(x**(x + S.Half) - Rational(9, 4)) == [Rational(3, 2)] + # a**g(x)=c + assert solve((-sqrt(sqrt(2)))**x - 2) == [4, log(2)/(log(2**Rational(1, 4)) + I*pi)] + assert solve((sqrt(2))**x - sqrt(sqrt(2))) == [S.Half] + assert solve((-sqrt(2))**x + 2*(sqrt(2))) == [3, + (3*log(2)**2 + 4*pi**2 - 4*I*pi*log(2))/(log(2)**2 + 4*pi**2)] + assert solve((sqrt(2))**x - 2*(sqrt(2))) == [3] + assert solve(I**x + 1) == [2] + assert solve((1 + I)**x - 2*I) == [2] + assert solve((sqrt(2) + sqrt(3))**x - (2*sqrt(6) + 5)**Rational(1, 3)) == [Rational(2, 3)] + # bases of both sides are equal + b = Symbol('b') + assert solve(b**x - b**2, x) == [2] + assert solve(b**x - 1/b, x) == [-1] + assert solve(b**x - b, x) == [1] + b = Symbol('b', positive=True) + assert solve(b**x - b**2, x) == [2] + assert solve(b**x - 1/b, x) == [-1] + + +def test_issue_10933(): + assert solve(x**4 + y*(x + 0.1), x) # doesn't fail + assert solve(I*x**4 + x**3 + x**2 + 1.) # doesn't fail + + +def test_Abs_handling(): + x = symbols('x', real=True) + assert solve(abs(x/y), x) == [0] + + +def test_issue_7982(): + x = Symbol('x') + # Test that no exception happens + assert solve([2*x**2 + 5*x + 20 <= 0, x >= 1.5], x) is S.false + # From #8040 + assert solve([x**3 - 8.08*x**2 - 56.48*x/5 - 106 >= 0, x - 1 <= 0], [x]) is S.false + + +def test_issue_14645(): + x, y = symbols('x y') + assert solve([x*y - x - y, x*y - x - y], [x, y]) == [(y/(y - 1), y)] + + +def test_issue_12024(): + x, y = symbols('x y') + assert solve(Piecewise((0.0, x < 0.1), (x, x >= 0.1)) - y) == \ + [{y: Piecewise((0.0, x < 0.1), (x, True))}] + + +def test_issue_17452(): + assert solve((7**x)**x + pi, x) == [-sqrt(log(pi) + I*pi)/sqrt(log(7)), + sqrt(log(pi) + I*pi)/sqrt(log(7))] + assert solve(x**(x/11) + pi/11, x) == [exp(LambertW(-11*log(11) + 11*log(pi) + 11*I*pi))] + + +def test_issue_17799(): + assert solve(-erf(x**(S(1)/3))**pi + I, x) == [] + + +def test_issue_17650(): + x = Symbol('x', real=True) + assert solve(abs(abs(x**2 - 1) - x) - x) == [1, -1 + sqrt(2), 1 + sqrt(2)] + + +def test_issue_17882(): + eq = -8*x**2/(9*(x**2 - 1)**(S(4)/3)) + 4/(3*(x**2 - 1)**(S(1)/3)) + assert unrad(eq) is None + + +def test_issue_17949(): + assert solve(exp(+x+x**2), x) == [] + assert solve(exp(-x+x**2), x) == [] + assert solve(exp(+x-x**2), x) == [] + assert solve(exp(-x-x**2), x) == [] + + +def test_issue_10993(): + assert solve(Eq(binomial(x, 2), 3)) == [-2, 3] + assert solve(Eq(pow(x, 2) + binomial(x, 3), x)) == [-4, 0, 1] + assert solve(Eq(binomial(x, 2), 0)) == [0, 1] + assert solve(a+binomial(x, 3), a) == [-binomial(x, 3)] + assert solve(x-binomial(a, 3) + binomial(y, 2) + sin(a), x) == [-sin(a) + binomial(a, 3) - binomial(y, 2)] + assert solve((x+1)-binomial(x+1, 3), x) == [-2, -1, 3] + + +def test_issue_11553(): + eq1 = x + y + 1 + eq2 = x + GoldenRatio + assert solve([eq1, eq2], x, y) == {x: -GoldenRatio, y: -1 + GoldenRatio} + eq3 = x + 2 + TribonacciConstant + assert solve([eq1, eq3], x, y) == {x: -2 - TribonacciConstant, y: 1 + TribonacciConstant} + + +def test_issue_19113_19102(): + t = S(1)/3 + solve(cos(x)**5-sin(x)**5) + assert solve(4*cos(x)**3 - 2*sin(x)**3) == [ + atan(2**(t)), -atan(2**(t)*(1 - sqrt(3)*I)/2), + -atan(2**(t)*(1 + sqrt(3)*I)/2)] + h = S.Half + assert solve(cos(x)**2 + sin(x)) == [ + 2*atan(-h + sqrt(5)/2 + sqrt(2)*sqrt(1 - sqrt(5))/2), + -2*atan(h + sqrt(5)/2 + sqrt(2)*sqrt(1 + sqrt(5))/2), + -2*atan(-sqrt(5)/2 + h + sqrt(2)*sqrt(1 - sqrt(5))/2), + -2*atan(-sqrt(2)*sqrt(1 + sqrt(5))/2 + h + sqrt(5)/2)] + assert solve(3*cos(x) - sin(x)) == [atan(3)] + + +def test_issue_19509(): + a = S(3)/4 + b = S(5)/8 + c = sqrt(5)/8 + d = sqrt(5)/4 + assert solve(1/(x -1)**5 - 1) == [2, + -d + a - sqrt(-b + c), + -d + a + sqrt(-b + c), + d + a - sqrt(-b - c), + d + a + sqrt(-b - c)] + +def test_issue_20747(): + THT, HT, DBH, dib, c0, c1, c2, c3, c4 = symbols('THT HT DBH dib c0 c1 c2 c3 c4') + f = DBH*c3 + THT*c4 + c2 + rhs = 1 - ((HT - 1)/(THT - 1))**c1*(1 - exp(c0/f)) + eq = dib - DBH*(c0 - f*log(rhs)) + term = ((1 - exp((DBH*c0 - dib)/(DBH*(DBH*c3 + THT*c4 + c2)))) + / (1 - exp(c0/(DBH*c3 + THT*c4 + c2)))) + sol = [THT*term**(1/c1) - term**(1/c1) + 1] + assert solve(eq, HT) == sol + + +def test_issue_27001(): + assert solve((x, x**2), (x, y, z), dict=True) == [{x: 0}] + s = a1, a2, a3, a4, a5 = symbols('a1:6') + eqs = [8*a1**4*a2 + 4*a1**2*a2**3 - 8*a1**2*a2*a4 + a2**5/2 - 2*a2**3*a4 + + 8*a2*a3**2 + 2*a2*a4**2 + 8*a2*a5, 12*a1**4 + 6*a1**2*a2**2 - + 8*a1**2*a4 + 3*a2**4/4 - 2*a2**2*a4 + 4*a3**2 + a4**2 + 4*a5, 16*a1**3 + + 4*a1*a2**2 - 8*a1*a4, -8*a1**2*a2 - 2*a2**3 + 4*a2*a4] + sol = [{a4: 2*a1**2 + a2**2/2, a5: -a3**2}, {a1: 0, a2: 0, a5: -a3**2 - a4**2/4}] + assert solve(eqs, s, dict=True) == sol + assert (g:=solve(groebner(eqs, s), dict=True)) == sol, g + + +def test_issue_20902(): + f = (t / ((1 + t) ** 2)) + assert solve(f.subs({t: 3 * x + 2}).diff(x) > 0, x) == (S(-1) < x) & (x < S(-1)/3) + assert solve(f.subs({t: 3 * x + 3}).diff(x) > 0, x) == (S(-4)/3 < x) & (x < S(-2)/3) + assert solve(f.subs({t: 3 * x + 4}).diff(x) > 0, x) == (S(-5)/3 < x) & (x < S(-1)) + assert solve(f.subs({t: 3 * x + 2}).diff(x) > 0, x) == (S(-1) < x) & (x < S(-1)/3) + + +def test_issue_21034(): + a = symbols('a', real=True) + system = [x - cosh(cos(4)), y - sinh(cos(a)), z - tanh(x)] + # constants inside hyperbolic functions should not be rewritten in terms of exp + assert solve(system, x, y, z) == [(cosh(cos(4)), sinh(cos(a)), tanh(cosh(cos(4))))] + # but if the variable of interest is present in a hyperbolic function, + # then it should be rewritten in terms of exp and solved further + newsystem = [(exp(x) - exp(-x)) - tanh(x)*(exp(x) + exp(-x)) + x - 5] + assert solve(newsystem, x) == {x: 5} + + +def test_issue_4886(): + z = a*sqrt(R**2*a**2 + R**2*b**2 - c**2)/(a**2 + b**2) + t = b*c/(a**2 + b**2) + sol = [((b*(t - z) - c)/(-a), t - z), ((b*(t + z) - c)/(-a), t + z)] + assert solve([x**2 + y**2 - R**2, a*x + b*y - c], x, y) == sol + + +def test_issue_6819(): + a, b, c, d = symbols('a b c d', positive=True) + assert solve(a*b**x - c*d**x, x) == [log(c/a)/log(b/d)] + + +def test_issue_17454(): + x = Symbol('x') + assert solve((1 - x - I)**4, x) == [1 - I] + + +def test_issue_21852(): + solution = [21 - 21*sqrt(2)/2] + assert solve(2*x + sqrt(2*x**2) - 21) == solution + + +def test_issue_21942(): + eq = -d + (a*c**(1 - e) + b**(1 - e)*(1 - a))**(1/(1 - e)) + sol = solve(eq, c, simplify=False, check=False) + assert sol == [((a*b**(1 - e) - b**(1 - e) + + d**(1 - e))/a)**(1/(1 - e))] + + +def test_solver_flags(): + root = solve(x**5 + x**2 - x - 1, cubics=False) + rad = solve(x**5 + x**2 - x - 1, cubics=True) + assert root != rad + + +def test_issue_22768(): + eq = 2*x**3 - 16*(y - 1)**6*z**3 + assert solve(eq.expand(), x, simplify=False + ) == [2*z*(y - 1)**2, z*(-1 + sqrt(3)*I)*(y - 1)**2, + -z*(1 + sqrt(3)*I)*(y - 1)**2] + + +def test_issue_22717(): + assert solve((-y**2 + log(y**2/x) + 2, -2*x*y + 2*x/y)) == [ + {y: -1, x: E}, {y: 1, x: E}] + + +def test_issue_25176(): + eq = (x - 5)**-8 - 3 + sol = solve(eq) + assert not any(eq.subs(x, i) for i in sol) + + +def test_issue_10169(): + eq = S(-8*a - x**5*(a + b + c + e) - x**4*(4*a - 2**Rational(3,4)*c + 4*c + + d + 2**Rational(3,4)*e + 4*e + k) - x**3*(-4*2**Rational(3,4)*c + sqrt(2)*c - + 2**Rational(3,4)*d + 4*d + sqrt(2)*e + 4*2**Rational(3,4)*e + 2**Rational(3,4)*k + 4*k) - + x**2*(4*sqrt(2)*c - 4*2**Rational(3,4)*d + sqrt(2)*d + 4*sqrt(2)*e + + sqrt(2)*k + 4*2**Rational(3,4)*k) - x*(2*a + 2*b + 4*sqrt(2)*d + + 4*sqrt(2)*k) + 5) + assert solve_undetermined_coeffs(eq, [a, b, c, d, e, k], x) == { + a: Rational(5,8), + b: Rational(-5,1032), + c: Rational(-40,129) - 5*2**Rational(3,4)/129 + 5*2**Rational(1,4)/1032, + d: -20*2**Rational(3,4)/129 - 10*sqrt(2)/129 - 5*2**Rational(1,4)/258, + e: Rational(-40,129) - 5*2**Rational(1,4)/1032 + 5*2**Rational(3,4)/129, + k: -10*sqrt(2)/129 + 5*2**Rational(1,4)/258 + 20*2**Rational(3,4)/129 + } + + +def test_solve_undetermined_coeffs_issue_23927(): + A, B, r, phi = symbols('A, B, r, phi') + e = Eq(A*sin(t) + B*cos(t), r*sin(t - phi)) + eq = (e.lhs - e.rhs).expand(trig=True) + soln = solve_undetermined_coeffs(eq, (r, phi), t) + assert soln == [{ + phi: 2*atan((A - sqrt(A**2 + B**2))/B), + r: (-A**2 + A*sqrt(A**2 + B**2) - B**2)/(A - sqrt(A**2 + B**2)) + }, { + phi: 2*atan((A + sqrt(A**2 + B**2))/B), + r: (A**2 + A*sqrt(A**2 + B**2) + B**2)/(A + sqrt(A**2 + B**2))/-1 + }] + +def test_issue_24368(): + # Ideally these would produce a solution, but for now just check that they + # don't fail with a RuntimeError + raises(NotImplementedError, lambda: solve(Mod(x**2, 49), x)) + s2 = Symbol('s2', integer=True, positive=True) + f = floor(s2/2 - S(1)/2) + raises(NotImplementedError, lambda: solve((Mod(f**2/(f + 1) + 2*f/(f + 1) + 1/(f + 1), 1))*f + Mod(f**2/(f + 1) + 2*f/(f + 1) + 1/(f + 1), 1), s2)) + + +def test_solve_Piecewise(): + assert [S(10)/3] == solve(3*Piecewise( + (S.NaN, x <= 0), + (20*x - 3*(x - 6)**2/2 - 176, (x >= 0) & (x >= 2) & (x>= 4) & (x >= 6) & (x < 10)), + (100 - 26*x, (x >= 0) & (x >= 2) & (x >= 4) & (x < 10)), + (16*x - 3*(x - 6)**2/2 - 176, (x >= 2) & (x >= 4) & (x >= 6) & (x < 10)), + (100 - 30*x, (x >= 2) & (x >= 4) & (x < 10)), + (30*x - 3*(x - 6)**2/2 - 196, (x>= 0) & (x >= 4) & (x >= 6) & (x < 10)), + (80 - 16*x, (x >= 0) & (x >= 4) & (x < 10)), + (26*x - 3*(x - 6)**2/2 - 196, (x >= 4) & (x >= 6) & (x < 10)), + (80 - 20*x, (x >= 4) & (x < 10)), + (40*x - 3*(x - 6)**2/2 - 256, (x >= 0) & (x >= 2) & (x >= 6) & (x < 10)), + (20 - 6*x, (x >= 0) & (x >= 2) & (x < 10)), + (36*x - 3*(x - 6)**2/2 - 256, (x >= 2) & (x >= 6) & (x < 10)), + (20 - 10*x, (x >= 2) & (x < 10)), + (50*x - 3*(x - 6)**2/2 - 276, (x >= 0) & (x >= 6) & (x < 10)), + (4*x, (x >= 0) & (x < 10)), + (46*x - 3*(x - 6)**2/2 - 276, (x >= 6) & (x < 10)), + (0, x < 10), # this will simplify away + (S.NaN,True))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_solveset.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_solveset.py new file mode 100644 index 0000000000000000000000000000000000000000..a1ba7a11e68ed518c4d83c050947b78756ade181 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/solvers/tests/test_solveset.py @@ -0,0 +1,3548 @@ +from math import isclose + +from sympy.calculus.util import stationary_points +from sympy.core.containers import Tuple +from sympy.core.function import (Function, Lambda, nfloat, diff) +from sympy.core.mod import Mod +from sympy.core.numbers import (E, I, Rational, oo, pi, Integer, all_close) +from sympy.core.relational import (Eq, Gt, Ne, Ge) +from sympy.core.singleton import S +from sympy.core.sorting import ordered +from sympy.core.symbol import (Dummy, Symbol, symbols) +from sympy.core.sympify import sympify +from sympy.functions.elementary.complexes import (Abs, arg, im, re, sign, conjugate) +from sympy.functions.elementary.exponential import (LambertW, exp, log) +from sympy.functions.elementary.hyperbolic import (HyperbolicFunction, + sinh, cosh, tanh, coth, sech, csch, asinh, acosh, atanh, acoth, asech, acsch) +from sympy.functions.elementary.miscellaneous import sqrt, Min, Max +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import ( + TrigonometricFunction, acos, acot, acsc, asec, asin, atan, atan2, + cos, cot, csc, sec, sin, tan) +from sympy.functions.special.error_functions import (erf, erfc, + erfcinv, erfinv) +from sympy.logic.boolalg import And +from sympy.matrices.dense import MutableDenseMatrix as Matrix +from sympy.matrices.immutable import ImmutableDenseMatrix +from sympy.polys.polytools import Poly +from sympy.polys.rootoftools import CRootOf +from sympy.sets.contains import Contains +from sympy.sets.conditionset import ConditionSet +from sympy.sets.fancysets import ImageSet, Range +from sympy.sets.sets import (Complement, FiniteSet, + Intersection, Interval, Union, imageset, ProductSet) +from sympy.simplify import simplify +from sympy.tensor.indexed import Indexed +from sympy.utilities.iterables import numbered_symbols + +from sympy.testing.pytest import (XFAIL, raises, skip, slow, SKIP, _both_exp_pow) +from sympy.core.random import verify_numerically as tn +from sympy.physics.units import cm + +from sympy.solvers import solve +from sympy.solvers.solveset import ( + solveset_real, domain_check, solveset_complex, linear_eq_to_matrix, + linsolve, _is_function_class_equation, invert_real, invert_complex, + _invert_trig_hyp_real, solveset, solve_decomposition, substitution, + nonlinsolve, solvify, + _is_finite_with_finite_vars, _transolve, _is_exponential, + _solve_exponential, _is_logarithmic, _is_lambert, + _solve_logarithm, _term_factors, _is_modular, NonlinearError) + +from sympy.abc import (a, b, c, d, e, f, g, h, i, j, k, l, m, n, q, r, + t, w, x, y, z) + + +def dumeq(i, j): + if type(i) in (list, tuple): + return all(dumeq(i, j) for i, j in zip(i, j)) + return i == j or i.dummy_eq(j) + + +def assert_close_ss(sol1, sol2): + """Test solutions with floats from solveset are close""" + sol1 = sympify(sol1) + sol2 = sympify(sol2) + assert isinstance(sol1, FiniteSet) + assert isinstance(sol2, FiniteSet) + assert len(sol1) == len(sol2) + assert all(isclose(v1, v2) for v1, v2 in zip(sol1, sol2)) + + +def assert_close_nl(sol1, sol2): + """Test solutions with floats from nonlinsolve are close""" + sol1 = sympify(sol1) + sol2 = sympify(sol2) + assert isinstance(sol1, FiniteSet) + assert isinstance(sol2, FiniteSet) + assert len(sol1) == len(sol2) + for s1, s2 in zip(sol1, sol2): + assert len(s1) == len(s2) + assert all(isclose(v1, v2) for v1, v2 in zip(s1, s2)) + + +@_both_exp_pow +def test_invert_real(): + x = Symbol('x', real=True) + + def ireal(x, s=S.Reals): + return Intersection(s, x) + + assert invert_real(exp(x), z, x) == (x, ireal(FiniteSet(log(z)))) + + y = Symbol('y', positive=True) + n = Symbol('n', real=True) + assert invert_real(x + 3, y, x) == (x, FiniteSet(y - 3)) + assert invert_real(x*3, y, x) == (x, FiniteSet(y / 3)) + + assert invert_real(exp(x), y, x) == (x, FiniteSet(log(y))) + assert invert_real(exp(3*x), y, x) == (x, FiniteSet(log(y) / 3)) + assert invert_real(exp(x + 3), y, x) == (x, FiniteSet(log(y) - 3)) + + assert invert_real(exp(x) + 3, y, x) == (x, ireal(FiniteSet(log(y - 3)))) + assert invert_real(exp(x)*3, y, x) == (x, FiniteSet(log(y / 3))) + + assert invert_real(log(x), y, x) == (x, FiniteSet(exp(y))) + assert invert_real(log(3*x), y, x) == (x, FiniteSet(exp(y) / 3)) + assert invert_real(log(x + 3), y, x) == (x, FiniteSet(exp(y) - 3)) + + assert invert_real(Abs(x), y, x) == (x, FiniteSet(y, -y)) + + assert invert_real(2**x, y, x) == (x, FiniteSet(log(y)/log(2))) + assert invert_real(2**exp(x), y, x) == (x, ireal(FiniteSet(log(log(y)/log(2))))) + + assert invert_real(x**2, y, x) == (x, FiniteSet(sqrt(y), -sqrt(y))) + assert invert_real(x**S.Half, y, x) == (x, FiniteSet(y**2)) + + raises(ValueError, lambda: invert_real(x, x, x)) + + # issue 21236 + assert invert_real(x**pi, y, x) == (x, FiniteSet(y**(1/pi))) + assert invert_real(x**pi, -E, x) == (x, S.EmptySet) + assert invert_real(x**Rational(3/2), 1000, x) == (x, FiniteSet(100)) + assert invert_real(x**1.0, 1, x) == (x**1.0, FiniteSet(1)) + + raises(ValueError, lambda: invert_real(S.One, y, x)) + + assert invert_real(x**31 + x, y, x) == (x**31 + x, FiniteSet(y)) + + lhs = x**31 + x + base_values = FiniteSet(y - 1, -y - 1) + assert invert_real(Abs(x**31 + x + 1), y, x) == (lhs, base_values) + + assert dumeq(invert_real(sin(x), y, x), (x, + ConditionSet(x, (S(-1) <= y) & (y <= S(1)), Union( + ImageSet(Lambda(n, 2*n*pi + asin(y)), S.Integers), + ImageSet(Lambda(n, pi*2*n + pi - asin(y)), S.Integers))))) + + assert dumeq(invert_real(sin(exp(x)), y, x), (x, + ConditionSet(x, (S(-1) <= y) & (y <= S(1)), Union( + ImageSet(Lambda(n, log(2*n*pi + asin(y))), S.Integers), + ImageSet(Lambda(n, log(pi*2*n + pi - asin(y))), S.Integers))))) + + assert dumeq(invert_real(csc(x), y, x), (x, + ConditionSet(x, ((S(1) <= y) & (y < oo)) | ((-oo < y) & (y <= S(-1))), + Union(ImageSet(Lambda(n, 2*n*pi + acsc(y)), S.Integers), + ImageSet(Lambda(n, 2*n*pi - acsc(y) + pi), S.Integers))))) + + assert dumeq(invert_real(csc(exp(x)), y, x), (x, + ConditionSet(x, ((S(1) <= y) & (y < oo)) | ((-oo < y) & (y <= S(-1))), + Union(ImageSet(Lambda(n, log(2*n*pi + acsc(y))), S.Integers), + ImageSet(Lambda(n, log(2*n*pi - acsc(y) + pi)), S.Integers))))) + + assert dumeq(invert_real(cos(x), y, x), (x, + ConditionSet(x, (S(-1) <= y) & (y <= S(1)), Union( + ImageSet(Lambda(n, 2*n*pi + acos(y)), S.Integers), + ImageSet(Lambda(n, 2*n*pi - acos(y)), S.Integers))))) + + assert dumeq(invert_real(cos(exp(x)), y, x), (x, + ConditionSet(x, (S(-1) <= y) & (y <= S(1)), Union( + ImageSet(Lambda(n, log(2*n*pi + acos(y))), S.Integers), + ImageSet(Lambda(n, log(2*n*pi - acos(y))), S.Integers))))) + + assert dumeq(invert_real(sec(x), y, x), (x, + ConditionSet(x, ((S(1) <= y) & (y < oo)) | ((-oo < y) & (y <= S(-1))), + Union(ImageSet(Lambda(n, 2*n*pi + asec(y)), S.Integers), \ + ImageSet(Lambda(n, 2*n*pi - asec(y)), S.Integers))))) + + assert dumeq(invert_real(sec(exp(x)), y, x), (x, + ConditionSet(x, ((S(1) <= y) & (y < oo)) | ((-oo < y) & (y <= S(-1))), + Union(ImageSet(Lambda(n, log(2*n*pi - asec(y))), S.Integers), + ImageSet(Lambda(n, log(2*n*pi + asec(y))), S.Integers))))) + + assert dumeq(invert_real(tan(x), y, x), (x, + ConditionSet(x, (-oo < y) & (y < oo), + ImageSet(Lambda(n, n*pi + atan(y)), S.Integers)))) + + assert dumeq(invert_real(tan(exp(x)), y, x), (x, + ConditionSet(x, (-oo < y) & (y < oo), + ImageSet(Lambda(n, log(n*pi + atan(y))), S.Integers)))) + + assert dumeq(invert_real(cot(x), y, x), (x, + ConditionSet(x, (-oo < y) & (y < oo), + ImageSet(Lambda(n, n*pi + acot(y)), S.Integers)))) + + assert dumeq(invert_real(cot(exp(x)), y, x), (x, + ConditionSet(x, (-oo < y) & (y < oo), + ImageSet(Lambda(n, log(n*pi + acot(y))), S.Integers)))) + + assert dumeq(invert_real(tan(tan(x)), y, x), + (x, ConditionSet(x, Eq(tan(tan(x)), y), S.Reals))) + # slight regression compared to previous result: + # (tan(x), imageset(Lambda(n, n*pi + atan(y)), S.Integers))) + + x = Symbol('x', positive=True) + assert invert_real(x**pi, y, x) == (x, FiniteSet(y**(1/pi))) + + r = Symbol('r', real=True) + p = Symbol('p', positive=True) + assert invert_real(sinh(x), r, x) == (x, FiniteSet(asinh(r))) + assert invert_real(sinh(log(x)), p, x) == (x, FiniteSet(exp(asinh(p)))) + + assert invert_real(cosh(x), r, x) == (x, Intersection( + FiniteSet(-acosh(r), acosh(r)), S.Reals)) + assert invert_real(cosh(x), p + 1, x) == (x, + FiniteSet(-acosh(p + 1), acosh(p + 1))) + + assert invert_real(tanh(x), r, x) == (x, Intersection(FiniteSet(atanh(r)), S.Reals)) + assert invert_real(coth(x), p+1, x) == (x, FiniteSet(acoth(p+1))) + assert invert_real(sech(x), r, x) == (x, Intersection( + FiniteSet(-asech(r), asech(r)), S.Reals)) + assert invert_real(csch(x), p, x) == (x, FiniteSet(acsch(p))) + + assert dumeq(invert_real(tanh(sin(x)), r, x), (x, + ConditionSet(x, (S(-1) <= atanh(r)) & (atanh(r) <= S(1)), Union( + ImageSet(Lambda(n, 2*n*pi + asin(atanh(r))), S.Integers), + ImageSet(Lambda(n, 2*n*pi - asin(atanh(r)) + pi), S.Integers))))) + + +def test_invert_trig_hyp_real(): + # check some codepaths that are not as easily reached otherwise + n = Dummy('n') + assert _invert_trig_hyp_real(cosh(x), Range(-5, 10, 1), x)[1].dummy_eq(Union( + ImageSet(Lambda(n, -acosh(n)), Range(1, 10, 1)), + ImageSet(Lambda(n, acosh(n)), Range(1, 10, 1)))) + assert _invert_trig_hyp_real(coth(x), Interval(-3, 2), x) == (x, Union( + Interval(-oo, -acoth(3)), Interval(acoth(2), oo))) + assert _invert_trig_hyp_real(tanh(x), Interval(-S.Half, 1), x) == (x, + Interval(-atanh(S.Half), oo)) + assert _invert_trig_hyp_real(sech(x), imageset(n, S.Half + n/3, S.Naturals0), x) == \ + (x, FiniteSet(-asech(S(1)/2), asech(S(1)/2), -asech(S(5)/6), asech(S(5)/6))) + assert _invert_trig_hyp_real(csch(x), S.Reals, x) == (x, + Union(Interval.open(-oo, 0), Interval.open(0, oo))) + + +def test_invert_complex(): + assert invert_complex(x + 3, y, x) == (x, FiniteSet(y - 3)) + assert invert_complex(x*3, y, x) == (x, FiniteSet(y / 3)) + assert invert_complex((x - 1)**3, 0, x) == (x, FiniteSet(1)) + + assert dumeq(invert_complex(exp(x), y, x), + (x, imageset(Lambda(n, I*(2*pi*n + arg(y)) + log(Abs(y))), S.Integers))) + + assert invert_complex(log(x), y, x) == (x, FiniteSet(exp(y))) + + raises(ValueError, lambda: invert_real(1, y, x)) + raises(ValueError, lambda: invert_complex(x, x, x)) + raises(ValueError, lambda: invert_complex(x, x, 1)) + + assert dumeq(invert_complex(sin(x), I, x), (x, Union( + ImageSet(Lambda(n, 2*n*pi + I*log(1 + sqrt(2))), S.Integers), + ImageSet(Lambda(n, 2*n*pi + pi - I*log(1 + sqrt(2))), S.Integers)))) + assert dumeq(invert_complex(cos(x), 1+I, x), (x, Union( + ImageSet(Lambda(n, 2*n*pi - acos(1 + I)), S.Integers), + ImageSet(Lambda(n, 2*n*pi + acos(1 + I)), S.Integers)))) + assert dumeq(invert_complex(tan(2*x), 1, x), (x, + ImageSet(Lambda(n, n*pi/2 + pi/8), S.Integers))) + assert dumeq(invert_complex(cot(x), 2*I, x), (x, + ImageSet(Lambda(n, n*pi - I*acoth(2)), S.Integers))) + + assert dumeq(invert_complex(sinh(x), 0, x), (x, Union( + ImageSet(Lambda(n, 2*n*I*pi), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi + I*pi), S.Integers)))) + assert dumeq(invert_complex(cosh(x), 0, x), (x, Union( + ImageSet(Lambda(n, 2*n*I*pi + I*pi/2), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi + 3*I*pi/2), S.Integers)))) + assert invert_complex(tanh(x), 1, x) == (x, S.EmptySet) + assert dumeq(invert_complex(tanh(x), a, x), (x, + ConditionSet(x, Ne(a, -1) & Ne(a, 1), + ImageSet(Lambda(n, n*I*pi + atanh(a)), S.Integers)))) + assert invert_complex(coth(x), 1, x) == (x, S.EmptySet) + assert dumeq(invert_complex(coth(x), a, x), (x, + ConditionSet(x, Ne(a, -1) & Ne(a, 1), + ImageSet(Lambda(n, n*I*pi + acoth(a)), S.Integers)))) + assert dumeq(invert_complex(sech(x), 2, x), (x, Union( + ImageSet(Lambda(n, 2*n*I*pi + I*pi/3), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi + 5*I*pi/3), S.Integers)))) + + +def test_domain_check(): + assert domain_check(1/(1 + (1/(x+1))**2), x, -1) is False + assert domain_check(x**2, x, 0) is True + assert domain_check(x, x, oo) is False + assert domain_check(0, x, oo) is False + + +def test_issue_11536(): + assert solveset(0**x - 100, x, S.Reals) == S.EmptySet + assert solveset(0**x - 1, x, S.Reals) == FiniteSet(0) + + +def test_issue_17479(): + f = (x**2 + y**2)**2 + (x**2 + z**2)**2 - 2*(2*x**2 + y**2 + z**2) + fx = f.diff(x) + fy = f.diff(y) + fz = f.diff(z) + sol = nonlinsolve([fx, fy, fz], [x, y, z]) + assert len(sol) >= 4 and len(sol) <= 20 + # nonlinsolve has been giving a varying number of solutions + # (originally 18, then 20, now 19) due to various internal changes. + # Unfortunately not all the solutions are actually valid and some are + # redundant. Since the original issue was that an exception was raised, + # this first test only checks that nonlinsolve returns a "plausible" + # solution set. The next test checks the result for correctness. + + +@XFAIL +def test_issue_18449(): + x, y, z = symbols("x, y, z") + f = (x**2 + y**2)**2 + (x**2 + z**2)**2 - 2*(2*x**2 + y**2 + z**2) + fx = diff(f, x) + fy = diff(f, y) + fz = diff(f, z) + sol = nonlinsolve([fx, fy, fz], [x, y, z]) + for (xs, ys, zs) in sol: + d = {x: xs, y: ys, z: zs} + assert tuple(_.subs(d).simplify() for _ in (fx, fy, fz)) == (0, 0, 0) + # After simplification and removal of duplicate elements, there should + # only be 4 parametric solutions left: + # simplifiedsolutions = FiniteSet((sqrt(1 - z**2), z, z), + # (-sqrt(1 - z**2), z, z), + # (sqrt(1 - z**2), -z, z), + # (-sqrt(1 - z**2), -z, z)) + # TODO: Is the above solution set definitely complete? + + +def test_issue_21047(): + f = (2 - x)**2 + (sqrt(x - 1) - 1)**6 + assert solveset(f, x, S.Reals) == FiniteSet(2) + + f = (sqrt(x)-1)**2 + (sqrt(x)+1)**2 -2*x**2 + sqrt(2) + assert solveset(f, x, S.Reals) == FiniteSet( + S.Half - sqrt(2*sqrt(2) + 5)/2, S.Half + sqrt(2*sqrt(2) + 5)/2) + + +def test_is_function_class_equation(): + assert _is_function_class_equation(TrigonometricFunction, + tan(x), x) is True + assert _is_function_class_equation(TrigonometricFunction, + tan(x) - 1, x) is True + assert _is_function_class_equation(TrigonometricFunction, + tan(x) + sin(x), x) is True + assert _is_function_class_equation(TrigonometricFunction, + tan(x) + sin(x) - a, x) is True + assert _is_function_class_equation(TrigonometricFunction, + sin(x)*tan(x) + sin(x), x) is True + assert _is_function_class_equation(TrigonometricFunction, + sin(x)*tan(x + a) + sin(x), x) is True + assert _is_function_class_equation(TrigonometricFunction, + sin(x)*tan(x*a) + sin(x), x) is True + assert _is_function_class_equation(TrigonometricFunction, + a*tan(x) - 1, x) is True + assert _is_function_class_equation(TrigonometricFunction, + tan(x)**2 + sin(x) - 1, x) is True + assert _is_function_class_equation(TrigonometricFunction, + tan(x) + x, x) is False + assert _is_function_class_equation(TrigonometricFunction, + tan(x**2), x) is False + assert _is_function_class_equation(TrigonometricFunction, + tan(x**2) + sin(x), x) is False + assert _is_function_class_equation(TrigonometricFunction, + tan(x)**sin(x), x) is False + assert _is_function_class_equation(TrigonometricFunction, + tan(sin(x)) + sin(x), x) is False + assert _is_function_class_equation(HyperbolicFunction, + tanh(x), x) is True + assert _is_function_class_equation(HyperbolicFunction, + tanh(x) - 1, x) is True + assert _is_function_class_equation(HyperbolicFunction, + tanh(x) + sinh(x), x) is True + assert _is_function_class_equation(HyperbolicFunction, + tanh(x) + sinh(x) - a, x) is True + assert _is_function_class_equation(HyperbolicFunction, + sinh(x)*tanh(x) + sinh(x), x) is True + assert _is_function_class_equation(HyperbolicFunction, + sinh(x)*tanh(x + a) + sinh(x), x) is True + assert _is_function_class_equation(HyperbolicFunction, + sinh(x)*tanh(x*a) + sinh(x), x) is True + assert _is_function_class_equation(HyperbolicFunction, + a*tanh(x) - 1, x) is True + assert _is_function_class_equation(HyperbolicFunction, + tanh(x)**2 + sinh(x) - 1, x) is True + assert _is_function_class_equation(HyperbolicFunction, + tanh(x) + x, x) is False + assert _is_function_class_equation(HyperbolicFunction, + tanh(x**2), x) is False + assert _is_function_class_equation(HyperbolicFunction, + tanh(x**2) + sinh(x), x) is False + assert _is_function_class_equation(HyperbolicFunction, + tanh(x)**sinh(x), x) is False + assert _is_function_class_equation(HyperbolicFunction, + tanh(sinh(x)) + sinh(x), x) is False + + +def test_garbage_input(): + raises(ValueError, lambda: solveset_real([y], y)) + x = Symbol('x', real=True) + assert solveset_real(x, 1) == S.EmptySet + assert solveset_real(x - 1, 1) == FiniteSet(x) + assert solveset_real(x, pi) == S.EmptySet + assert solveset_real(x, x**2) == S.EmptySet + + raises(ValueError, lambda: solveset_complex([x], x)) + assert solveset_complex(x, pi) == S.EmptySet + + raises(ValueError, lambda: solveset((x, y), x)) + raises(ValueError, lambda: solveset(x + 1, S.Reals)) + raises(ValueError, lambda: solveset(x + 1, x, 2)) + + +def test_solve_mul(): + assert solveset_real((a*x + b)*(exp(x) - 3), x) == \ + Union({log(3)}, Intersection({-b/a}, S.Reals)) + anz = Symbol('anz', nonzero=True) + bb = Symbol('bb', real=True) + assert solveset_real((anz*x + bb)*(exp(x) - 3), x) == \ + FiniteSet(-bb/anz, log(3)) + assert solveset_real((2*x + 8)*(8 + exp(x)), x) == FiniteSet(S(-4)) + assert solveset_real(x/log(x), x) is S.EmptySet + + +def test_solve_invert(): + assert solveset_real(exp(x) - 3, x) == FiniteSet(log(3)) + assert solveset_real(log(x) - 3, x) == FiniteSet(exp(3)) + + assert solveset_real(3**(x + 2), x) == FiniteSet() + assert solveset_real(3**(2 - x), x) == FiniteSet() + + assert solveset_real(y - b*exp(a/x), x) == Intersection( + S.Reals, FiniteSet(a/log(y/b))) + + # issue 4504 + assert solveset_real(2**x - 10, x) == FiniteSet(1 + log(5)/log(2)) + + +def test_issue_25768(): + assert dumeq(solveset_real(sin(x) - S.Half, x), Union( + ImageSet(Lambda(n, pi*2*n + pi/6), S.Integers), + ImageSet(Lambda(n, pi*2*n + pi*5/6), S.Integers))) + n1 = solveset_real(sin(x) - 0.5, x).n(5) + n2 = solveset_real(sin(x) - S.Half, x).n(5) + # help pass despite fp differences + eq = [i.replace( + lambda x:x.is_Float, + lambda x:Rational(x).limit_denominator(1000)) for i in (n1, n2)] + assert dumeq(*eq),(n1,n2) + + +def test_errorinverses(): + assert solveset_real(erf(x) - S.Half, x) == \ + FiniteSet(erfinv(S.Half)) + assert solveset_real(erfinv(x) - 2, x) == \ + FiniteSet(erf(2)) + assert solveset_real(erfc(x) - S.One, x) == \ + FiniteSet(erfcinv(S.One)) + assert solveset_real(erfcinv(x) - 2, x) == FiniteSet(erfc(2)) + + +def test_solve_polynomial(): + x = Symbol('x', real=True) + y = Symbol('y', real=True) + assert solveset_real(3*x - 2, x) == FiniteSet(Rational(2, 3)) + + assert solveset_real(x**2 - 1, x) == FiniteSet(-S.One, S.One) + assert solveset_real(x - y**3, x) == FiniteSet(y ** 3) + + assert solveset_real(x**3 - 15*x - 4, x) == FiniteSet( + -2 + 3 ** S.Half, + S(4), + -2 - 3 ** S.Half) + + assert solveset_real(sqrt(x) - 1, x) == FiniteSet(1) + assert solveset_real(sqrt(x) - 2, x) == FiniteSet(4) + assert solveset_real(x**Rational(1, 4) - 2, x) == FiniteSet(16) + assert solveset_real(x**Rational(1, 3) - 3, x) == FiniteSet(27) + assert len(solveset_real(x**5 + x**3 + 1, x)) == 1 + assert len(solveset_real(-2*x**3 + 4*x**2 - 2*x + 6, x)) > 0 + assert solveset_real(x**6 + x**4 + I, x) is S.EmptySet + + +def test_return_root_of(): + f = x**5 - 15*x**3 - 5*x**2 + 10*x + 20 + s = list(solveset_complex(f, x)) + for root in s: + assert root.func == CRootOf + + # if one uses solve to get the roots of a polynomial that has a CRootOf + # solution, make sure that the use of nfloat during the solve process + # doesn't fail. Note: if you want numerical solutions to a polynomial + # it is *much* faster to use nroots to get them than to solve the + # equation only to get CRootOf solutions which are then numerically + # evaluated. So for eq = x**5 + 3*x + 7 do Poly(eq).nroots() rather + # than [i.n() for i in solve(eq)] to get the numerical roots of eq. + assert nfloat(list(solveset_complex(x**5 + 3*x**3 + 7, x))[0], + exponent=False) == CRootOf(x**5 + 3*x**3 + 7, 0).n() + + sol = list(solveset_complex(x**6 - 2*x + 2, x)) + assert all(isinstance(i, CRootOf) for i in sol) and len(sol) == 6 + + f = x**5 - 15*x**3 - 5*x**2 + 10*x + 20 + s = list(solveset_complex(f, x)) + for root in s: + assert root.func == CRootOf + + s = x**5 + 4*x**3 + 3*x**2 + Rational(7, 4) + assert solveset_complex(s, x) == \ + FiniteSet(*Poly(s*4, domain='ZZ').all_roots()) + + # Refer issue #7876 + eq = x*(x - 1)**2*(x + 1)*(x**6 - x + 1) + assert solveset_complex(eq, x) == \ + FiniteSet(-1, 0, 1, CRootOf(x**6 - x + 1, 0), + CRootOf(x**6 - x + 1, 1), + CRootOf(x**6 - x + 1, 2), + CRootOf(x**6 - x + 1, 3), + CRootOf(x**6 - x + 1, 4), + CRootOf(x**6 - x + 1, 5)) + + +def test_solveset_sqrt_1(): + assert solveset_real(sqrt(5*x + 6) - 2 - x, x) == \ + FiniteSet(-S.One, S(2)) + assert solveset_real(sqrt(x - 1) - x + 7, x) == FiniteSet(10) + assert solveset_real(sqrt(x - 2) - 5, x) == FiniteSet(27) + assert solveset_real(sqrt(x) - 2 - 5, x) == FiniteSet(49) + assert solveset_real(sqrt(x**3), x) == FiniteSet(0) + assert solveset_real(sqrt(x - 1), x) == FiniteSet(1) + assert solveset_real(sqrt((x-3)/x), x) == FiniteSet(3) + assert solveset_real(sqrt((x-3)/x)-Rational(1, 2), x) == \ + FiniteSet(4) + +def test_solveset_sqrt_2(): + x = Symbol('x', real=True) + y = Symbol('y', real=True) + # http://tutorial.math.lamar.edu/Classes/Alg/SolveRadicalEqns.aspx#Solve_Rad_Ex2_a + assert solveset_real(sqrt(2*x - 1) - sqrt(x - 4) - 2, x) == \ + FiniteSet(S(5), S(13)) + assert solveset_real(sqrt(x + 7) + 2 - sqrt(3 - x), x) == \ + FiniteSet(-6) + + # http://www.purplemath.com/modules/solverad.htm + assert solveset_real(sqrt(17*x - sqrt(x**2 - 5)) - 7, x) == \ + FiniteSet(3) + + eq = x + 1 - (x**4 + 4*x**3 - x)**Rational(1, 4) + assert solveset_real(eq, x) == FiniteSet(Rational(-1, 2), Rational(-1, 3)) + + eq = sqrt(2*x + 9) - sqrt(x + 1) - sqrt(x + 4) + assert solveset_real(eq, x) == FiniteSet(0) + + eq = sqrt(x + 4) + sqrt(2*x - 1) - 3*sqrt(x - 1) + assert solveset_real(eq, x) == FiniteSet(5) + + eq = sqrt(x)*sqrt(x - 7) - 12 + assert solveset_real(eq, x) == FiniteSet(16) + + eq = sqrt(x - 3) + sqrt(x) - 3 + assert solveset_real(eq, x) == FiniteSet(4) + + eq = sqrt(2*x**2 - 7) - (3 - x) + assert solveset_real(eq, x) == FiniteSet(-S(8), S(2)) + + # others + eq = sqrt(9*x**2 + 4) - (3*x + 2) + assert solveset_real(eq, x) == FiniteSet(0) + + assert solveset_real(sqrt(x - 3) - sqrt(x) - 3, x) == FiniteSet() + + eq = (2*x - 5)**Rational(1, 3) - 3 + assert solveset_real(eq, x) == FiniteSet(16) + + assert solveset_real(sqrt(x) + sqrt(sqrt(x)) - 4, x) == \ + FiniteSet((Rational(-1, 2) + sqrt(17)/2)**4) + + eq = sqrt(x) - sqrt(x - 1) + sqrt(sqrt(x)) + assert solveset_real(eq, x) == FiniteSet() + + eq = (x - 4)**2 + (sqrt(x) - 2)**4 + assert solveset_real(eq, x) == FiniteSet(-4, 4) + + eq = (sqrt(x) + sqrt(x + 1) + sqrt(1 - x) - 6*sqrt(5)/5) + ans = solveset_real(eq, x) + ra = S('''-1484/375 - 4*(-S(1)/2 + sqrt(3)*I/2)*(-12459439/52734375 + + 114*sqrt(12657)/78125)**(S(1)/3) - 172564/(140625*(-S(1)/2 + + sqrt(3)*I/2)*(-12459439/52734375 + 114*sqrt(12657)/78125)**(S(1)/3))''') + rb = Rational(4, 5) + assert all(abs(eq.subs(x, i).n()) < 1e-10 for i in (ra, rb)) and \ + len(ans) == 2 and \ + {i.n(chop=True) for i in ans} == \ + {i.n(chop=True) for i in (ra, rb)} + + assert solveset_real(sqrt(x) + x**Rational(1, 3) + + x**Rational(1, 4), x) == FiniteSet(0) + + assert solveset_real(x/sqrt(x**2 + 1), x) == FiniteSet(0) + + eq = (x - y**3)/((y**2)*sqrt(1 - y**2)) + assert solveset_real(eq, x) == FiniteSet(y**3) + + # issue 4497 + assert solveset_real(1/(5 + x)**Rational(1, 5) - 9, x) == \ + FiniteSet(Rational(-295244, 59049)) + + +@XFAIL +def test_solve_sqrt_fail(): + # this only works if we check real_root(eq.subs(x, Rational(1, 3))) + # but checksol doesn't work like that + eq = (x**3 - 3*x**2)**Rational(1, 3) + 1 - x + assert solveset_real(eq, x) == FiniteSet(Rational(1, 3)) + + +@slow +def test_solve_sqrt_3(): + R = Symbol('R') + eq = sqrt(2)*R*sqrt(1/(R + 1)) + (R + 1)*(sqrt(2)*sqrt(1/(R + 1)) - 1) + sol = solveset_complex(eq, R) + fset = [Rational(5, 3) + 4*sqrt(10)*cos(atan(3*sqrt(111)/251)/3)/3, + -sqrt(10)*cos(atan(3*sqrt(111)/251)/3)/3 + + 40*re(1/((Rational(-1, 2) - sqrt(3)*I/2)*(Rational(251, 27) + sqrt(111)*I/9)**Rational(1, 3)))/9 + + sqrt(30)*sin(atan(3*sqrt(111)/251)/3)/3 + Rational(5, 3) + + I*(-sqrt(30)*cos(atan(3*sqrt(111)/251)/3)/3 - + sqrt(10)*sin(atan(3*sqrt(111)/251)/3)/3 + + 40*im(1/((Rational(-1, 2) - sqrt(3)*I/2)*(Rational(251, 27) + sqrt(111)*I/9)**Rational(1, 3)))/9)] + cset = [40*re(1/((Rational(-1, 2) + sqrt(3)*I/2)*(Rational(251, 27) + sqrt(111)*I/9)**Rational(1, 3)))/9 - + sqrt(10)*cos(atan(3*sqrt(111)/251)/3)/3 - sqrt(30)*sin(atan(3*sqrt(111)/251)/3)/3 + + Rational(5, 3) + + I*(40*im(1/((Rational(-1, 2) + sqrt(3)*I/2)*(Rational(251, 27) + sqrt(111)*I/9)**Rational(1, 3)))/9 - + sqrt(10)*sin(atan(3*sqrt(111)/251)/3)/3 + + sqrt(30)*cos(atan(3*sqrt(111)/251)/3)/3)] + + fs = FiniteSet(*fset) + cs = ConditionSet(R, Eq(eq, 0), FiniteSet(*cset)) + assert sol == (fs - {-1}) | (cs - {-1}) + + # the number of real roots will depend on the value of m: for m=1 there are 4 + # and for m=-1 there are none. + eq = -sqrt((m - q)**2 + (-m/(2*q) + S.Half)**2) + sqrt((-m**2/2 - sqrt( + 4*m**4 - 4*m**2 + 8*m + 1)/4 - Rational(1, 4))**2 + (m**2/2 - m - sqrt( + 4*m**4 - 4*m**2 + 8*m + 1)/4 - Rational(1, 4))**2) + unsolved_object = ConditionSet(q, Eq(sqrt((m - q)**2 + (-m/(2*q) + S.Half)**2) - + sqrt((-m**2/2 - sqrt(4*m**4 - 4*m**2 + 8*m + 1)/4 - Rational(1, 4))**2 + (m**2/2 - m - + sqrt(4*m**4 - 4*m**2 + 8*m + 1)/4 - Rational(1, 4))**2), 0), S.Reals) + assert solveset_real(eq, q) == unsolved_object + + +def test_solve_polynomial_symbolic_param(): + assert solveset_complex((x**2 - 1)**2 - a, x) == \ + FiniteSet(sqrt(1 + sqrt(a)), -sqrt(1 + sqrt(a)), + sqrt(1 - sqrt(a)), -sqrt(1 - sqrt(a))) + + # issue 4507 + assert solveset_complex(y - b/(1 + a*x), x) == \ + FiniteSet((b/y - 1)/a) - FiniteSet(-1/a) + + # issue 4508 + assert solveset_complex(y - b*x/(a + x), x) == \ + FiniteSet(-a*y/(y - b)) - FiniteSet(-a) + + +def test_solve_rational(): + assert solveset_real(1/x + 1, x) == FiniteSet(-S.One) + assert solveset_real(1/exp(x) - 1, x) == FiniteSet(0) + assert solveset_real(x*(1 - 5/x), x) == FiniteSet(5) + assert solveset_real(2*x/(x + 2) - 1, x) == FiniteSet(2) + assert solveset_real((x**2/(7 - x)).diff(x), x) == \ + FiniteSet(S.Zero, S(14)) + + +def test_solveset_real_gen_is_pow(): + assert solveset_real(sqrt(1) + 1, x) is S.EmptySet + + +def test_no_sol(): + assert solveset(1 - oo*x) is S.EmptySet + assert solveset(oo*x, x) is S.EmptySet + assert solveset(oo*x - oo, x) is S.EmptySet + assert solveset_real(4, x) is S.EmptySet + assert solveset_real(exp(x), x) is S.EmptySet + assert solveset_real(x**2 + 1, x) is S.EmptySet + assert solveset_real(-3*a/sqrt(x), x) is S.EmptySet + assert solveset_real(1/x, x) is S.EmptySet + assert solveset_real(-(1 + x)/(2 + x)**2 + 1/(2 + x), x + ) is S.EmptySet + + +def test_sol_zero_real(): + assert solveset_real(0, x) == S.Reals + assert solveset(0, x, Interval(1, 2)) == Interval(1, 2) + assert solveset_real(-x**2 - 2*x + (x + 1)**2 - 1, x) == S.Reals + + +def test_no_sol_rational_extragenous(): + assert solveset_real((x/(x + 1) + 3)**(-2), x) is S.EmptySet + assert solveset_real((x - 1)/(1 + 1/(x - 1)), x) is S.EmptySet + + +def test_solve_polynomial_cv_1a(): + """ + Test for solving on equations that can be converted to + a polynomial equation using the change of variable y -> x**Rational(p, q) + """ + assert solveset_real(sqrt(x) - 1, x) == FiniteSet(1) + assert solveset_real(sqrt(x) - 2, x) == FiniteSet(4) + assert solveset_real(x**Rational(1, 4) - 2, x) == FiniteSet(16) + assert solveset_real(x**Rational(1, 3) - 3, x) == FiniteSet(27) + assert solveset_real(x*(x**(S.One / 3) - 3), x) == \ + FiniteSet(S.Zero, S(27)) + + +def test_solveset_real_rational(): + """Test solveset_real for rational functions""" + x = Symbol('x', real=True) + y = Symbol('y', real=True) + assert solveset_real((x - y**3) / ((y**2)*sqrt(1 - y**2)), x) \ + == FiniteSet(y**3) + # issue 4486 + assert solveset_real(2*x/(x + 2) - 1, x) == FiniteSet(2) + + +def test_solveset_real_log(): + assert solveset_real(log((x-1)*(x+1)), x) == \ + FiniteSet(sqrt(2), -sqrt(2)) + + +def test_poly_gens(): + assert solveset_real(4**(2*(x**2) + 2*x) - 8, x) == \ + FiniteSet(Rational(-3, 2), S.Half) + + +def test_solve_abs(): + n = Dummy('n') + raises(ValueError, lambda: solveset(Abs(x) - 1, x)) + assert solveset(Abs(x) - n, x, S.Reals).dummy_eq( + ConditionSet(x, Contains(n, Interval(0, oo)), {-n, n})) + assert solveset_real(Abs(x) - 2, x) == FiniteSet(-2, 2) + assert solveset_real(Abs(x) + 2, x) is S.EmptySet + assert solveset_real(Abs(x + 3) - 2*Abs(x - 3), x) == \ + FiniteSet(1, 9) + assert solveset_real(2*Abs(x) - Abs(x - 1), x) == \ + FiniteSet(-1, Rational(1, 3)) + + sol = ConditionSet( + x, + And( + Contains(b, Interval(0, oo)), + Contains(a + b, Interval(0, oo)), + Contains(a - b, Interval(0, oo))), + FiniteSet(-a - b - 3, -a + b - 3, a - b - 3, a + b - 3)) + eq = Abs(Abs(x + 3) - a) - b + assert invert_real(eq, 0, x)[1] == sol + reps = {a: 3, b: 1} + eqab = eq.subs(reps) + for si in sol.subs(reps): + assert not eqab.subs(x, si) + assert dumeq(solveset(Eq(sin(Abs(x)), 1), x, domain=S.Reals), Union( + Intersection(Interval(0, oo), Union( + Intersection(ImageSet(Lambda(n, 2*n*pi + 3*pi/2), S.Integers), + Interval(-oo, 0)), + Intersection(ImageSet(Lambda(n, 2*n*pi + pi/2), S.Integers), + Interval(0, oo)))))) + + +def test_issue_9824(): + assert dumeq(solveset(sin(x)**2 - 2*sin(x) + 1, x), ImageSet(Lambda(n, 2*n*pi + pi/2), S.Integers)) + assert dumeq(solveset(cos(x)**2 - 2*cos(x) + 1, x), ImageSet(Lambda(n, 2*n*pi), S.Integers)) + + +def test_issue_9565(): + assert solveset_real(Abs((x - 1)/(x - 5)) <= Rational(1, 3), x) == Interval(-1, 2) + + +def test_issue_10069(): + eq = abs(1/(x - 1)) - 1 > 0 + assert solveset_real(eq, x) == Union( + Interval.open(0, 1), Interval.open(1, 2)) + + +def test_real_imag_splitting(): + a, b = symbols('a b', real=True) + assert solveset_real(sqrt(a**2 - b**2) - 3, a) == \ + FiniteSet(-sqrt(b**2 + 9), sqrt(b**2 + 9)) + assert solveset_real(sqrt(a**2 + b**2) - 3, a) != \ + S.EmptySet + + +def test_units(): + assert solveset_real(1/x - 1/(2*cm), x) == FiniteSet(2*cm) + + +def test_solve_only_exp_1(): + y = Symbol('y', positive=True) + assert solveset_real(exp(x) - y, x) == FiniteSet(log(y)) + assert solveset_real(exp(x) + exp(-x) - 4, x) == \ + FiniteSet(log(-sqrt(3) + 2), log(sqrt(3) + 2)) + assert solveset_real(exp(x) + exp(-x) - y, x) != S.EmptySet + + +def test_atan2(): + # The .inverse() method on atan2 works only if x.is_real is True and the + # second argument is a real constant + assert solveset_real(atan2(x, 2) - pi/3, x) == FiniteSet(2*sqrt(3)) + + +def test_piecewise_solveset(): + eq = Piecewise((x - 2, Gt(x, 2)), (2 - x, True)) - 3 + assert set(solveset_real(eq, x)) == set(FiniteSet(-1, 5)) + + absxm3 = Piecewise( + (x - 3, 0 <= x - 3), + (3 - x, 0 > x - 3)) + y = Symbol('y', positive=True) + assert solveset_real(absxm3 - y, x) == FiniteSet(-y + 3, y + 3) + + f = Piecewise(((x - 2)**2, x >= 0), (0, True)) + assert solveset(f, x, domain=S.Reals) == Union(FiniteSet(2), Interval(-oo, 0, True, True)) + + assert solveset( + Piecewise((x + 1, x > 0), (I, True)) - I, x, S.Reals + ) == Interval(-oo, 0) + + assert solveset(Piecewise((x - 1, Ne(x, I)), (x, True)), x) == FiniteSet(1) + + # issue 19718 + g = Piecewise((1, x > 10), (0, True)) + assert solveset(g > 0, x, S.Reals) == Interval.open(10, oo) + + from sympy.logic.boolalg import BooleanTrue + f = BooleanTrue() + assert solveset(f, x, domain=Interval(-3, 10)) == Interval(-3, 10) + + # issue 20552 + f = Piecewise((0, Eq(x, 0)), (x**2/Abs(x), True)) + g = Piecewise((0, Eq(x, pi)), ((x - pi)/sin(x), True)) + assert solveset(f, x, domain=S.Reals) == FiniteSet(0) + assert solveset(g) == FiniteSet(pi) + + +def test_solveset_complex_polynomial(): + assert solveset_complex(a*x**2 + b*x + c, x) == \ + FiniteSet(-b/(2*a) - sqrt(-4*a*c + b**2)/(2*a), + -b/(2*a) + sqrt(-4*a*c + b**2)/(2*a)) + + assert solveset_complex(x - y**3, y) == FiniteSet( + (-x**Rational(1, 3))/2 + I*sqrt(3)*x**Rational(1, 3)/2, + x**Rational(1, 3), + (-x**Rational(1, 3))/2 - I*sqrt(3)*x**Rational(1, 3)/2) + + assert solveset_complex(x + 1/x - 1, x) == \ + FiniteSet(S.Half + I*sqrt(3)/2, S.Half - I*sqrt(3)/2) + + +def test_sol_zero_complex(): + assert solveset_complex(0, x) is S.Complexes + + +def test_solveset_complex_rational(): + assert solveset_complex((x - 1)*(x - I)/(x - 3), x) == \ + FiniteSet(1, I) + + assert solveset_complex((x - y**3)/((y**2)*sqrt(1 - y**2)), x) == \ + FiniteSet(y**3) + assert solveset_complex(-x**2 - I, x) == \ + FiniteSet(-sqrt(2)/2 + sqrt(2)*I/2, sqrt(2)/2 - sqrt(2)*I/2) + + +def test_solve_quintics(): + skip("This test is too slow") + f = x**5 - 110*x**3 - 55*x**2 + 2310*x + 979 + s = solveset_complex(f, x) + for root in s: + res = f.subs(x, root.n()).n() + assert tn(res, 0) + + f = x**5 + 15*x + 12 + s = solveset_complex(f, x) + for root in s: + res = f.subs(x, root.n()).n() + assert tn(res, 0) + + +def test_solveset_complex_exp(): + assert dumeq(solveset_complex(exp(x) - 1, x), + imageset(Lambda(n, I*2*n*pi), S.Integers)) + assert dumeq(solveset_complex(exp(x) - I, x), + imageset(Lambda(n, I*(2*n*pi + pi/2)), S.Integers)) + assert solveset_complex(1/exp(x), x) == S.EmptySet + assert dumeq(solveset_complex(sinh(x).rewrite(exp), x), + imageset(Lambda(n, n*pi*I), S.Integers)) + + +def test_solveset_real_exp(): + assert solveset(Eq((-2)**x, 4), x, S.Reals) == FiniteSet(2) + assert solveset(Eq(-2**x, 4), x, S.Reals) == S.EmptySet + assert solveset(Eq((-3)**x, 27), x, S.Reals) == S.EmptySet + assert solveset(Eq((-5)**(x+1), 625), x, S.Reals) == FiniteSet(3) + assert solveset(Eq(2**(x-3), -16), x, S.Reals) == S.EmptySet + assert solveset(Eq((-3)**(x - 3), -3**39), x, S.Reals) == FiniteSet(42) + assert solveset(Eq(2**x, y), x, S.Reals) == Intersection(S.Reals, FiniteSet(log(y)/log(2))) + + assert invert_real((-2)**(2*x) - 16, 0, x) == (x, FiniteSet(2)) + + +def test_solve_complex_log(): + assert solveset_complex(log(x), x) == FiniteSet(1) + assert solveset_complex(1 - log(a + 4*x**2), x) == \ + FiniteSet(-sqrt(-a + E)/2, sqrt(-a + E)/2) + + +def test_solve_complex_sqrt(): + assert solveset_complex(sqrt(5*x + 6) - 2 - x, x) == \ + FiniteSet(-S.One, S(2)) + assert solveset_complex(sqrt(5*x + 6) - (2 + 2*I) - x, x) == \ + FiniteSet(-S(2), 3 - 4*I) + assert solveset_complex(4*x*(1 - a * sqrt(x)), x) == \ + FiniteSet(S.Zero, 1 / a ** 2) + + +def test_solveset_complex_tan(): + s = solveset_complex(tan(x).rewrite(exp), x) + assert dumeq(s, imageset(Lambda(n, pi*n), S.Integers) - \ + imageset(Lambda(n, pi*n + pi/2), S.Integers)) + + +@_both_exp_pow +def test_solve_trig(): + assert dumeq(solveset_real(sin(x), x), + Union(imageset(Lambda(n, 2*pi*n), S.Integers), + imageset(Lambda(n, 2*pi*n + pi), S.Integers))) + + assert dumeq(solveset_real(sin(x) - 1, x), + imageset(Lambda(n, 2*pi*n + pi/2), S.Integers)) + + assert dumeq(solveset_real(cos(x), x), + Union(imageset(Lambda(n, 2*pi*n + pi/2), S.Integers), + imageset(Lambda(n, 2*pi*n + pi*Rational(3, 2)), S.Integers))) + + assert dumeq(solveset_real(sin(x) + cos(x), x), + Union(imageset(Lambda(n, 2*n*pi + pi*Rational(3, 4)), S.Integers), + imageset(Lambda(n, 2*n*pi + pi*Rational(7, 4)), S.Integers))) + + assert solveset_real(sin(x)**2 + cos(x)**2, x) == S.EmptySet + + assert dumeq(solveset_complex(cos(x) - S.Half, x), + Union(imageset(Lambda(n, 2*n*pi + pi*Rational(5, 3)), S.Integers), + imageset(Lambda(n, 2*n*pi + pi/3), S.Integers))) + + assert dumeq(solveset(sin(y + a) - sin(y), a, domain=S.Reals), + ConditionSet(a, (S(-1) <= sin(y)) & (sin(y) <= S(1)), Union( + ImageSet(Lambda(n, 2*n*pi - y + asin(sin(y))), S.Integers), + ImageSet(Lambda(n, 2*n*pi - y - asin(sin(y)) + pi), S.Integers)))) + + assert dumeq(solveset_real(sin(2*x)*cos(x) + cos(2*x)*sin(x)-1, x), + ImageSet(Lambda(n, n*pi*Rational(2, 3) + pi/6), S.Integers)) + + assert dumeq(solveset_real(2*tan(x)*sin(x) + 1, x), Union( + ImageSet(Lambda(n, 2*n*pi + atan(sqrt(2)*sqrt(-1 + sqrt(17))/ + (1 - sqrt(17))) + pi), S.Integers), + ImageSet(Lambda(n, 2*n*pi - atan(sqrt(2)*sqrt(-1 + sqrt(17))/ + (1 - sqrt(17))) + pi), S.Integers))) + + assert dumeq(solveset_real(cos(2*x)*cos(4*x) - 1, x), + ImageSet(Lambda(n, n*pi), S.Integers)) + + assert dumeq(solveset(sin(x/10) + Rational(3, 4)), Union( + ImageSet(Lambda(n, 20*n*pi - 10*asin(S(3)/4) + 20*pi), S.Integers), + ImageSet(Lambda(n, 20*n*pi + 10*asin(S(3)/4) + 10*pi), S.Integers))) + + assert dumeq(solveset(cos(x/15) + cos(x/5)), Union( + ImageSet(Lambda(n, 30*n*pi + 15*pi/2), S.Integers), + ImageSet(Lambda(n, 30*n*pi + 45*pi/2), S.Integers), + ImageSet(Lambda(n, 30*n*pi + 75*pi/4), S.Integers), + ImageSet(Lambda(n, 30*n*pi + 45*pi/4), S.Integers), + ImageSet(Lambda(n, 30*n*pi + 105*pi/4), S.Integers), + ImageSet(Lambda(n, 30*n*pi + 15*pi/4), S.Integers))) + + assert dumeq(solveset(sec(sqrt(2)*x/3) + 5), Union( + ImageSet(Lambda(n, 3*sqrt(2)*(2*n*pi - asec(-5))/2), S.Integers), + ImageSet(Lambda(n, 3*sqrt(2)*(2*n*pi + asec(-5))/2), S.Integers))) + + assert dumeq(simplify(solveset(tan(pi*x) - cot(pi/2*x))), Union( + ImageSet(Lambda(n, 4*n + 1), S.Integers), + ImageSet(Lambda(n, 4*n + 3), S.Integers), + ImageSet(Lambda(n, 4*n + Rational(7, 3)), S.Integers), + ImageSet(Lambda(n, 4*n + Rational(5, 3)), S.Integers), + ImageSet(Lambda(n, 4*n + Rational(11, 3)), S.Integers), + ImageSet(Lambda(n, 4*n + Rational(1, 3)), S.Integers))) + + assert dumeq(solveset(cos(9*x)), Union( + ImageSet(Lambda(n, 2*n*pi/9 + pi/18), S.Integers), + ImageSet(Lambda(n, 2*n*pi/9 + pi/6), S.Integers))) + + assert dumeq(solveset(sin(8*x) + cot(12*x), x, S.Reals), Union( + ImageSet(Lambda(n, n*pi/2 + pi/8), S.Integers), + ImageSet(Lambda(n, n*pi/2 + 3*pi/8), S.Integers), + ImageSet(Lambda(n, n*pi/2 + 5*pi/16), S.Integers), + ImageSet(Lambda(n, n*pi/2 + 3*pi/16), S.Integers), + ImageSet(Lambda(n, n*pi/2 + 7*pi/16), S.Integers), + ImageSet(Lambda(n, n*pi/2 + pi/16), S.Integers))) + + # This is the only remaining solveset test that actually ends up being solved + # by _solve_trig2(). All others are handled by the improved _solve_trig1. + assert dumeq(solveset_real(2*cos(x)*cos(2*x) - 1, x), + Union(ImageSet(Lambda(n, 2*n*pi + 2*atan(sqrt(-2*2**Rational(1, 3)*(67 + + 9*sqrt(57))**Rational(2, 3) + 8*2**Rational(2, 3) + 11*(67 + + 9*sqrt(57))**Rational(1, 3))/(3*(67 + 9*sqrt(57))**Rational(1, 6)))), S.Integers), + ImageSet(Lambda(n, 2*n*pi - 2*atan(sqrt(-2*2**Rational(1, 3)*(67 + + 9*sqrt(57))**Rational(2, 3) + 8*2**Rational(2, 3) + 11*(67 + + 9*sqrt(57))**Rational(1, 3))/(3*(67 + 9*sqrt(57))**Rational(1, 6))) + + 2*pi), S.Integers))) + + # issue #16870 + assert dumeq(simplify(solveset(sin(x/180*pi) - S.Half, x, S.Reals)), Union( + ImageSet(Lambda(n, 360*n + 150), S.Integers), + ImageSet(Lambda(n, 360*n + 30), S.Integers))) + + +def test_solve_trig_hyp_by_inversion(): + n = Dummy('n') + assert solveset_real(sin(2*x + 3) - S(1)/2, x).dummy_eq(Union( + ImageSet(Lambda(n, n*pi - S(3)/2 + 13*pi/12), S.Integers), + ImageSet(Lambda(n, n*pi - S(3)/2 + 17*pi/12), S.Integers))) + assert solveset_complex(sin(2*x + 3) - S(1)/2, x).dummy_eq(Union( + ImageSet(Lambda(n, n*pi - S(3)/2 + 13*pi/12), S.Integers), + ImageSet(Lambda(n, n*pi - S(3)/2 + 17*pi/12), S.Integers))) + assert solveset_real(tan(x) - tan(pi/10), x).dummy_eq( + ImageSet(Lambda(n, n*pi + pi/10), S.Integers)) + assert solveset_complex(tan(x) - tan(pi/10), x).dummy_eq( + ImageSet(Lambda(n, n*pi + pi/10), S.Integers)) + + assert solveset_real(3*cosh(2*x) - 5, x) == FiniteSet( + -acosh(S(5)/3)/2, acosh(S(5)/3)/2) + assert solveset_complex(3*cosh(2*x) - 5, x).dummy_eq(Union( + ImageSet(Lambda(n, n*I*pi - acosh(S(5)/3)/2), S.Integers), + ImageSet(Lambda(n, n*I*pi + acosh(S(5)/3)/2), S.Integers))) + assert solveset_real(sinh(x - 3) - 2, x) == FiniteSet( + asinh(2) + 3) + assert solveset_complex(sinh(x - 3) - 2, x).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*I*pi + asinh(2) + 3), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi - asinh(2) + 3 + I*pi), S.Integers))) + + assert solveset_real(cos(sinh(x))-cos(pi/12), x).dummy_eq(Union( + ImageSet(Lambda(n, asinh(2*n*pi + pi/12)), S.Integers), + ImageSet(Lambda(n, asinh(2*n*pi + 23*pi/12)), S.Integers))) + assert solveset(cos(sinh(x))-cos(pi/12), x, Interval(2,3)) == \ + FiniteSet(asinh(23*pi/12), asinh(25*pi/12)) + assert solveset_real(cosh(x**2-1)-2, x) == FiniteSet( + -sqrt(1 + acosh(2)), sqrt(1 + acosh(2))) + + assert solveset_real(sin(x) - 2, x) == S.EmptySet # issue #17334 + assert solveset_real(cos(x) + 2, x) == S.EmptySet + assert solveset_real(sec(x), x) == S.EmptySet + assert solveset_real(csc(x), x) == S.EmptySet + assert solveset_real(cosh(x) + 1, x) == S.EmptySet + assert solveset_real(coth(x), x) == S.EmptySet + assert solveset_real(sech(x) - 2, x) == S.EmptySet + assert solveset_real(sech(x), x) == S.EmptySet + assert solveset_real(tanh(x) + 1, x) == S.EmptySet + assert solveset_complex(tanh(x), 1) == S.EmptySet + assert solveset_complex(coth(x), -1) == S.EmptySet + assert solveset_complex(sech(x), 0) == S.EmptySet + assert solveset_complex(csch(x), 0) == S.EmptySet + + assert solveset_real(abs(csch(x)) - 3, x) == FiniteSet(-acsch(3), acsch(3)) + + assert solveset_real(tanh(x**2 - 1) - exp(-9), x) == FiniteSet( + -sqrt(atanh(exp(-9)) + 1), sqrt(atanh(exp(-9)) + 1)) + + assert solveset_real(coth(log(x)) + 2, x) == FiniteSet(exp(-acoth(2))) + assert solveset_real(coth(exp(x)) + 2, x) == S.EmptySet + + assert solveset_complex(sinh(x) - I/2, x).dummy_eq(Union( + ImageSet(Lambda(n, 2*I*pi*n + 5*I*pi/6), S.Integers), + ImageSet(Lambda(n, 2*I*pi*n + I*pi/6), S.Integers))) + assert solveset_complex(sinh(x/10) + Rational(3, 4), x).dummy_eq(Union( + ImageSet(Lambda(n, 20*n*I*pi - 10*asinh(S(3)/4)), S.Integers), + ImageSet(Lambda(n, 20*n*I*pi + 10*asinh(S(3)/4) + 10*I*pi), S.Integers))) + assert solveset_complex(sech(sqrt(2)*x/3) + 5, x).dummy_eq(Union( + ImageSet(Lambda(n, 3*sqrt(2)*(2*n*I*pi - asech(-5))/2), S.Integers), + ImageSet(Lambda(n, 3*sqrt(2)*(2*n*I*pi + asech(-5))/2), S.Integers))) + assert solveset_complex(cosh(9*x), x).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*I*pi/9 + I*pi/18), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi/9 + I*pi/6), S.Integers))) + + eq = (x**5 -4*x + 1).subs(x, coth(z)) + assert solveset(eq, z, S.Complexes).dummy_eq(Union( + ImageSet(Lambda(n, n*I*pi + acoth(CRootOf(x**5 -4*x + 1, 0))), S.Integers), + ImageSet(Lambda(n, n*I*pi + acoth(CRootOf(x**5 -4*x + 1, 1))), S.Integers), + ImageSet(Lambda(n, n*I*pi + acoth(CRootOf(x**5 -4*x + 1, 2))), S.Integers), + ImageSet(Lambda(n, n*I*pi + acoth(CRootOf(x**5 -4*x + 1, 3))), S.Integers), + ImageSet(Lambda(n, n*I*pi + acoth(CRootOf(x**5 -4*x + 1, 4))), S.Integers))) + assert solveset(eq, z, S.Reals) == FiniteSet( + acoth(CRootOf(x**5 - 4*x + 1, 0)), acoth(CRootOf(x**5 - 4*x + 1, 2))) + + eq = ((x-sqrt(3)/2)*(x+2)).expand().subs(x, cos(x)) + assert solveset(eq, x, S.Complexes).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*pi - acos(-2)), S.Integers), + ImageSet(Lambda(n, 2*n*pi + acos(-2)), S.Integers), + ImageSet(Lambda(n, 2*n*pi + pi/6), S.Integers), + ImageSet(Lambda(n, 2*n*pi + 11*pi/6), S.Integers))) + assert solveset(eq, x, S.Reals).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*pi + pi/6), S.Integers), + ImageSet(Lambda(n, 2*n*pi + 11*pi/6), S.Integers))) + + assert solveset((1+sec(sqrt(3)*x+4)**2)/(1-sec(sqrt(3)*x+4))).dummy_eq(Union( + ImageSet(Lambda(n, sqrt(3)*(2*n*pi - 4 - asec(I))/3), S.Integers), + ImageSet(Lambda(n, sqrt(3)*(2*n*pi - 4 + asec(I))/3), S.Integers), + ImageSet(Lambda(n, sqrt(3)*(2*n*pi - 4 - asec(-I))/3), S.Integers), + ImageSet(Lambda(n, sqrt(3)*(2*n*pi - 4 + asec(-I))/3), S.Integers))) + + assert all_close(solveset(tan(3.14*x)**(S(3)/2)-5.678, x, Interval(0, 3)), + FiniteSet(0.403301114561067, 0.403301114561067 + 0.318471337579618*pi, + 0.403301114561067 + 0.636942675159236*pi)) + + +def test_old_trig_issues(): + # issues #9606 / #9531: + assert solveset(sinh(x), x, S.Reals) == FiniteSet(0) + assert solveset(sinh(x), x, S.Complexes).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*I*pi), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi + I*pi), S.Integers))) + + # issues #11218 / #18427 + assert solveset(sin(pi*x), x, S.Reals).dummy_eq(Union( + ImageSet(Lambda(n, (2*n*pi + pi)/pi), S.Integers), + ImageSet(Lambda(n, 2*n), S.Integers))) + assert solveset(sin(pi*x), x).dummy_eq(Union( + ImageSet(Lambda(n, (2*n*pi + pi)/pi), S.Integers), + ImageSet(Lambda(n, 2*n), S.Integers))) + + # issue #17543 + assert solveset(I*cot(8*x - 8*E), x).dummy_eq( + ImageSet(Lambda(n, pi*n/8 - 13*pi/16 + E), S.Integers)) + + # issue #20798 + assert all_close(solveset(cos(2*x) - 0.5, x, Interval(0, 2*pi)), FiniteSet( + 0.523598775598299, -0.523598775598299 + pi, + -0.523598775598299 + 2*pi, 0.523598775598299 + pi)) + sol = Union(ImageSet(Lambda(n, n*pi - 0.523598775598299), S.Integers), + ImageSet(Lambda(n, n*pi + 0.523598775598299), S.Integers)) + ret = solveset(cos(2*x) - 0.5, x, S.Reals) + # replace Dummy n by the regular Symbol n to allow all_close comparison. + ret = ret.subs(ret.atoms(Dummy).pop(), n) + assert all_close(ret, sol) + ret = solveset(cos(2*x) - 0.5, x, S.Complexes) + ret = ret.subs(ret.atoms(Dummy).pop(), n) + assert all_close(ret, sol) + + # issue #21296 / #17667 + assert solveset(tan(x)-sqrt(2), x, Interval(0, pi/2)) == FiniteSet(atan(sqrt(2))) + assert solveset(tan(x)-pi, x, Interval(0, pi/2)) == FiniteSet(atan(pi)) + + # issue #17667 + # not yet working properly: + # solveset(cos(x)-y, x, Interval(0, pi)) + assert solveset(cos(x)-y, x, S.Reals).dummy_eq( + ConditionSet(x,(S(-1) <= y) & (y <= S(1)), Union( + ImageSet(Lambda(n, 2*n*pi - acos(y)), S.Integers), + ImageSet(Lambda(n, 2*n*pi + acos(y)), S.Integers)))) + + # issue #17579 + # Valid result, but the intersection could potentially be simplified. + assert solveset(sin(log(x)), x, Interval(0,1, True, False)).dummy_eq( + Union(Intersection(ImageSet(Lambda(n, exp(2*n*pi)), S.Integers), Interval.Lopen(0, 1)), + Intersection(ImageSet(Lambda(n, exp(2*n*pi + pi)), S.Integers), Interval.Lopen(0, 1)))) + + # issue #17334 + assert solveset(sin(x) - sin(1), x, S.Reals).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*pi + 1), S.Integers), + ImageSet(Lambda(n, 2*n*pi - 1 + pi), S.Integers))) + assert solveset(sin(x) - sqrt(5)/3, x, S.Reals).dummy_eq(Union( + ImageSet(Lambda(n, 2*n*pi + asin(sqrt(5)/3)), S.Integers), + ImageSet(Lambda(n, 2*n*pi - asin(sqrt(5)/3) + pi), S.Integers))) + assert solveset(sinh(x)-cosh(2), x, S.Reals) == FiniteSet(asinh(cosh(2))) + + # issue 9825 + assert solveset(Eq(tan(x), y), x, domain=S.Reals).dummy_eq( + ConditionSet(x, (-oo < y) & (y < oo), + ImageSet(Lambda(n, n*pi + atan(y)), S.Integers))) + r = Symbol('r', real=True) + assert solveset(Eq(tan(x), r), x, domain=S.Reals).dummy_eq( + ImageSet(Lambda(n, n*pi + atan(r)), S.Integers)) + + +def test_solve_hyperbolic(): + # actual solver: _solve_trig1 + n = Dummy('n') + assert solveset(sinh(x) + cosh(x), x) == S.EmptySet + assert solveset(sinh(x) + cos(x), x) == ConditionSet(x, + Eq(cos(x) + sinh(x), 0), S.Complexes) + assert solveset_real(sinh(x) + sech(x), x) == FiniteSet( + log(sqrt(sqrt(5) - 2))) + assert solveset_real(cosh(2*x) + 2*sinh(x) - 5, x) == FiniteSet( + log(-2 + sqrt(5)), log(1 + sqrt(2))) + assert solveset_real((coth(x) + sinh(2*x))/cosh(x) - 3, x) == FiniteSet( + log(S.Half + sqrt(5)/2), log(1 + sqrt(2))) + assert solveset_real(cosh(x)*sinh(x) - 2, x) == FiniteSet( + log(4 + sqrt(17))/2) + assert solveset_real(sinh(x) + tanh(x) - 1, x) == FiniteSet( + log(sqrt(2)/2 + sqrt(-S(1)/2 + sqrt(2)))) + + assert dumeq(solveset_complex(sinh(x) + sech(x), x), Union( + ImageSet(Lambda(n, 2*n*I*pi + log(sqrt(-2 + sqrt(5)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi/2) + log(sqrt(2 + sqrt(5)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi) + log(sqrt(-2 + sqrt(5)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi - pi/2) + log(sqrt(2 + sqrt(5)))), S.Integers))) + + assert dumeq(solveset(cosh(x/15) + cosh(x/5)), Union( + ImageSet(Lambda(n, 15*I*(2*n*pi + pi/2)), S.Integers), + ImageSet(Lambda(n, 15*I*(2*n*pi - pi/2)), S.Integers), + ImageSet(Lambda(n, 15*I*(2*n*pi - 3*pi/4)), S.Integers), + ImageSet(Lambda(n, 15*I*(2*n*pi + 3*pi/4)), S.Integers), + ImageSet(Lambda(n, 15*I*(2*n*pi - pi/4)), S.Integers), + ImageSet(Lambda(n, 15*I*(2*n*pi + pi/4)), S.Integers))) + + assert dumeq(solveset(tanh(pi*x) - coth(pi/2*x)), Union( + ImageSet(Lambda(n, 2*I*(2*n*pi + pi/2)/pi), S.Integers), + ImageSet(Lambda(n, 2*I*(2*n*pi - pi/2)/pi), S.Integers))) + + # issues #18490 / #19489 + assert solveset(cosh(x) + cosh(3*x) - cosh(5*x), x, S.Reals + ).dummy_eq(ConditionSet(x, + Eq(cosh(x) + cosh(3*x) - cosh(5*x), 0), S.Reals)) + assert solveset(sinh(8*x) + coth(12*x)).dummy_eq( + ConditionSet(x, Eq(sinh(8*x) + coth(12*x), 0), S.Complexes)) + + +def test_solve_trig_hyp_symbolic(): + # actual solver: invert_trig_hyp + assert dumeq(solveset(sin(a*x), x), ConditionSet(x, Ne(a, 0), Union( + ImageSet(Lambda(n, (2*n*pi + pi)/a), S.Integers), + ImageSet(Lambda(n, 2*n*pi/a), S.Integers)))) + + assert dumeq(solveset(cosh(x/a), x), ConditionSet(x, Ne(a, 0), Union( + ImageSet(Lambda(n, a*(2*n*I*pi + I*pi/2)), S.Integers), + ImageSet(Lambda(n, a*(2*n*I*pi + 3*I*pi/2)), S.Integers)))) + + assert dumeq(solveset(sin(2*sqrt(3)/3*a**2/(b*pi)*x) + + cos(4*sqrt(3)/3*a**2/(b*pi)*x), x), + ConditionSet(x, Ne(b, 0) & Ne(a**2, 0), Union( + ImageSet(Lambda(n, sqrt(3)*pi*b*(2*n*pi + pi/2)/(2*a**2)), S.Integers), + ImageSet(Lambda(n, sqrt(3)*pi*b*(2*n*pi - 5*pi/6)/(2*a**2)), S.Integers), + ImageSet(Lambda(n, sqrt(3)*pi*b*(2*n*pi - pi/6)/(2*a**2)), S.Integers)))) + + assert dumeq(solveset(cosh((a**2 + 1)*x) - 3, x), ConditionSet( + x, Ne(a**2 + 1, 0), Union( + ImageSet(Lambda(n, (2*n*I*pi - acosh(3))/(a**2 + 1)), S.Integers), + ImageSet(Lambda(n, (2*n*I*pi + acosh(3))/(a**2 + 1)), S.Integers)))) + + ar = Symbol('ar', real=True) + assert solveset(cosh((ar**2 + 1)*x) - 2, x, S.Reals) == FiniteSet( + -acosh(2)/(ar**2 + 1), acosh(2)/(ar**2 + 1)) + + # actual solver: _solve_trig1 + assert dumeq(simplify(solveset(cot((1 + I)*x) - cot((3 + 3*I)*x), x)), Union( + ImageSet(Lambda(n, pi*(1 - I)*(4*n + 1)/4), S.Integers), + ImageSet(Lambda(n, pi*(1 - I)*(4*n - 1)/4), S.Integers))) + + +def test_issue_9616(): + assert dumeq(solveset(sinh(x) + tanh(x) - 1, x), Union( + ImageSet(Lambda(n, 2*n*I*pi + log(sqrt(2)/2 + sqrt(-S.Half + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi - atan(sqrt(2)*sqrt(S.Half + sqrt(2))) + pi) + + log(sqrt(1 + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi) + log(-sqrt(2)/2 + sqrt(-S.Half + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi - pi + atan(sqrt(2)*sqrt(S.Half + sqrt(2)))) + + log(sqrt(1 + sqrt(2)))), S.Integers))) + f1 = (sinh(x)).rewrite(exp) + f2 = (tanh(x)).rewrite(exp) + assert dumeq(solveset(f1 + f2 - 1, x), Union( + Complement(ImageSet( + Lambda(n, I*(2*n*pi + pi) + log(-sqrt(2)/2 + sqrt(-S.Half + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi)/2), S.Integers)), + Complement(ImageSet(Lambda(n, I*(2*n*pi - pi + atan(sqrt(2)*sqrt(S.Half + sqrt(2)))) + + log(sqrt(1 + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi)/2), S.Integers)), + Complement(ImageSet(Lambda(n, I*(2*n*pi - atan(sqrt(2)*sqrt(S.Half + sqrt(2))) + pi) + + log(sqrt(1 + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi)/2), S.Integers)), + Complement( + ImageSet(Lambda(n, 2*n*I*pi + log(sqrt(2)/2 + sqrt(-S.Half + sqrt(2)))), S.Integers), + ImageSet(Lambda(n, I*(2*n*pi + pi)/2), S.Integers)))) + + +def test_solve_invalid_sol(): + assert 0 not in solveset_real(sin(x)/x, x) + assert 0 not in solveset_complex((exp(x) - 1)/x, x) + + +@XFAIL +def test_solve_trig_simplified(): + n = Dummy('n') + assert dumeq(solveset_real(sin(x), x), + imageset(Lambda(n, n*pi), S.Integers)) + + assert dumeq(solveset_real(cos(x), x), + imageset(Lambda(n, n*pi + pi/2), S.Integers)) + + assert dumeq(solveset_real(cos(x) + sin(x), x), + imageset(Lambda(n, n*pi - pi/4), S.Integers)) + + +@XFAIL +def test_solve_lambert(): + assert solveset_real(x*exp(x) - 1, x) == FiniteSet(LambertW(1)) + assert solveset_real(exp(x) + x, x) == FiniteSet(-LambertW(1)) + assert solveset_real(x + 2**x, x) == \ + FiniteSet(-LambertW(log(2))/log(2)) + + # issue 4739 + ans = solveset_real(3*x + 5 + 2**(-5*x + 3), x) + assert ans == FiniteSet(Rational(-5, 3) + + LambertW(-10240*2**Rational(1, 3)*log(2)/3)/(5*log(2))) + + eq = 2*(3*x + 4)**5 - 6*7**(3*x + 9) + result = solveset_real(eq, x) + ans = FiniteSet((log(2401) + + 5*LambertW(-log(7**(7*3**Rational(1, 5)/5))))/(3*log(7))/-1) + assert result == ans + assert solveset_real(eq.expand(), x) == result + + assert solveset_real(5*x - 1 + 3*exp(2 - 7*x), x) == \ + FiniteSet(Rational(1, 5) + LambertW(-21*exp(Rational(3, 5))/5)/7) + + assert solveset_real(2*x + 5 + log(3*x - 2), x) == \ + FiniteSet(Rational(2, 3) + LambertW(2*exp(Rational(-19, 3))/3)/2) + + assert solveset_real(3*x + log(4*x), x) == \ + FiniteSet(LambertW(Rational(3, 4))/3) + + assert solveset_real(x**x - 2) == FiniteSet(exp(LambertW(log(2)))) + + a = Symbol('a') + assert solveset_real(-a*x + 2*x*log(x), x) == FiniteSet(exp(a/2)) + a = Symbol('a', real=True) + assert solveset_real(a/x + exp(x/2), x) == \ + FiniteSet(2*LambertW(-a/2)) + assert solveset_real((a/x + exp(x/2)).diff(x), x) == \ + FiniteSet(4*LambertW(sqrt(2)*sqrt(a)/4)) + + # coverage test + assert solveset_real(tanh(x + 3)*tanh(x - 3) - 1, x) is S.EmptySet + + assert solveset_real((x**2 - 2*x + 1).subs(x, log(x) + 3*x), x) == \ + FiniteSet(LambertW(3*S.Exp1)/3) + assert solveset_real((x**2 - 2*x + 1).subs(x, (log(x) + 3*x)**2 - 1), x) == \ + FiniteSet(LambertW(3*exp(-sqrt(2)))/3, LambertW(3*exp(sqrt(2)))/3) + assert solveset_real((x**2 - 2*x - 2).subs(x, log(x) + 3*x), x) == \ + FiniteSet(LambertW(3*exp(1 + sqrt(3)))/3, LambertW(3*exp(-sqrt(3) + 1))/3) + assert solveset_real(x*log(x) + 3*x + 1, x) == \ + FiniteSet(exp(-3 + LambertW(-exp(3)))) + eq = (x*exp(x) - 3).subs(x, x*exp(x)) + assert solveset_real(eq, x) == \ + FiniteSet(LambertW(3*exp(-LambertW(3)))) + + assert solveset_real(3*log(a**(3*x + 5)) + a**(3*x + 5), x) == \ + FiniteSet(-((log(a**5) + LambertW(Rational(1, 3)))/(3*log(a)))) + p = symbols('p', positive=True) + assert solveset_real(3*log(p**(3*x + 5)) + p**(3*x + 5), x) == \ + FiniteSet( + log((-3**Rational(1, 3) - 3**Rational(5, 6)*I)*LambertW(Rational(1, 3))**Rational(1, 3)/(2*p**Rational(5, 3)))/log(p), + log((-3**Rational(1, 3) + 3**Rational(5, 6)*I)*LambertW(Rational(1, 3))**Rational(1, 3)/(2*p**Rational(5, 3)))/log(p), + log((3*LambertW(Rational(1, 3))/p**5)**(1/(3*log(p)))),) # checked numerically + # check collection + b = Symbol('b') + eq = 3*log(a**(3*x + 5)) + b*log(a**(3*x + 5)) + a**(3*x + 5) + assert solveset_real(eq, x) == FiniteSet( + -((log(a**5) + LambertW(1/(b + 3)))/(3*log(a)))) + + # issue 4271 + assert solveset_real((a/x + exp(x/2)).diff(x, 2), x) == FiniteSet( + 6*LambertW((-1)**Rational(1, 3)*a**Rational(1, 3)/3)) + + assert solveset_real(x**3 - 3**x, x) == \ + FiniteSet(-3/log(3)*LambertW(-log(3)/3)) + assert solveset_real(3**cos(x) - cos(x)**3) == FiniteSet( + acos(-3*LambertW(-log(3)/3)/log(3))) + + assert solveset_real(x**2 - 2**x, x) == \ + solveset_real(-x**2 + 2**x, x) + + assert solveset_real(3*log(x) - x*log(3)) == FiniteSet( + -3*LambertW(-log(3)/3)/log(3), + -3*LambertW(-log(3)/3, -1)/log(3)) + + assert solveset_real(LambertW(2*x) - y) == FiniteSet( + y*exp(y)/2) + + +@XFAIL +def test_other_lambert(): + a = Rational(6, 5) + assert solveset_real(x**a - a**x, x) == FiniteSet( + a, -a*LambertW(-log(a)/a)/log(a)) + + +@_both_exp_pow +def test_solveset(): + f = Function('f') + raises(ValueError, lambda: solveset(x + y)) + assert solveset(x, 1) == S.EmptySet + assert solveset(f(1)**2 + y + 1, f(1) + ) == FiniteSet(-sqrt(-y - 1), sqrt(-y - 1)) + assert solveset(f(1)**2 - 1, f(1), S.Reals) == FiniteSet(-1, 1) + assert solveset(f(1)**2 + 1, f(1)) == FiniteSet(-I, I) + assert solveset(x - 1, 1) == FiniteSet(x) + assert solveset(sin(x) - cos(x), sin(x)) == FiniteSet(cos(x)) + + assert solveset(0, domain=S.Reals) == S.Reals + assert solveset(1) == S.EmptySet + assert solveset(True, domain=S.Reals) == S.Reals # issue 10197 + assert solveset(False, domain=S.Reals) == S.EmptySet + + assert solveset(exp(x) - 1, domain=S.Reals) == FiniteSet(0) + assert solveset(exp(x) - 1, x, S.Reals) == FiniteSet(0) + assert solveset(Eq(exp(x), 1), x, S.Reals) == FiniteSet(0) + assert solveset(exp(x) - 1, exp(x), S.Reals) == FiniteSet(1) + A = Indexed('A', x) + assert solveset(A - 1, A, S.Reals) == FiniteSet(1) + + assert solveset(x - 1 >= 0, x, S.Reals) == Interval(1, oo) + assert solveset(exp(x) - 1 >= 0, x, S.Reals) == Interval(0, oo) + + assert dumeq(solveset(exp(x) - 1, x), imageset(Lambda(n, 2*I*pi*n), S.Integers)) + assert dumeq(solveset(Eq(exp(x), 1), x), imageset(Lambda(n, 2*I*pi*n), + S.Integers)) + # issue 13825 + assert solveset(x**2 + f(0) + 1, x) == {-sqrt(-f(0) - 1), sqrt(-f(0) - 1)} + + # issue 19977 + assert solveset(atan(log(x)) > 0, x, domain=Interval.open(0, oo)) == Interval.open(1, oo) + + +@_both_exp_pow +def test_multi_exp(): + k1, k2, k3 = symbols('k1, k2, k3') + assert dumeq(solveset(exp(exp(x)) - 5, x),\ + imageset(Lambda(((k1, n),), I*(2*k1*pi + arg(2*n*I*pi + log(5))) + log(Abs(2*n*I*pi + log(5)))),\ + ProductSet(S.Integers, S.Integers))) + assert dumeq(solveset((d*exp(exp(a*x + b)) + c), x),\ + imageset(Lambda(x, (-b + x)/a), ImageSet(Lambda(((k1, n),), \ + I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))) + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d))))), \ + ProductSet(S.Integers, S.Integers)))) + + assert dumeq(solveset((d*exp(exp(exp(a*x + b))) + c), x),\ + imageset(Lambda(x, (-b + x)/a), ImageSet(Lambda(((k2, k1, n),), \ + I*(2*k2*pi + arg(I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))) + \ + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))))) + log(Abs(I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + \ + log(Abs(c/d)))) + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d))))))), \ + ProductSet(S.Integers, S.Integers, S.Integers)))) + + assert dumeq(solveset((d*exp(exp(exp(exp(a*x + b)))) + c), x),\ + ImageSet(Lambda(x, (-b + x)/a), ImageSet(Lambda(((k3, k2, k1, n),), \ + I*(2*k3*pi + arg(I*(2*k2*pi + arg(I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))) + \ + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))))) + log(Abs(I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + \ + log(Abs(c/d)))) + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))))))) + log(Abs(I*(2*k2*pi + \ + arg(I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))) + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))))) + \ + log(Abs(I*(2*k1*pi + arg(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d)))) + log(Abs(I*(2*n*pi + arg(-c/d)) + log(Abs(c/d))))))))), \ + ProductSet(S.Integers, S.Integers, S.Integers, S.Integers)))) + + +def test__solveset_multi(): + from sympy.solvers.solveset import _solveset_multi + from sympy.sets import Reals + + # Basic univariate case: + assert _solveset_multi([x**2-1], [x], [S.Reals]) == FiniteSet((1,), (-1,)) + + # Linear systems of two equations + assert _solveset_multi([x+y, x+1], [x, y], [Reals, Reals]) == FiniteSet((-1, 1)) + assert _solveset_multi([x+y, x+1], [y, x], [Reals, Reals]) == FiniteSet((1, -1)) + assert _solveset_multi([x+y, x-y-1], [x, y], [Reals, Reals]) == FiniteSet((S(1)/2, -S(1)/2)) + assert _solveset_multi([x-1, y-2], [x, y], [Reals, Reals]) == FiniteSet((1, 2)) + # assert dumeq(_solveset_multi([x+y], [x, y], [Reals, Reals]), ImageSet(Lambda(x, (x, -x)), Reals)) + assert dumeq(_solveset_multi([x+y], [x, y], [Reals, Reals]), Union( + ImageSet(Lambda(((x,),), (x, -x)), ProductSet(Reals)), + ImageSet(Lambda(((y,),), (-y, y)), ProductSet(Reals)))) + assert _solveset_multi([x+y, x+y+1], [x, y], [Reals, Reals]) == S.EmptySet + assert _solveset_multi([x+y, x-y, x-1], [x, y], [Reals, Reals]) == S.EmptySet + assert _solveset_multi([x+y, x-y, x-1], [y, x], [Reals, Reals]) == S.EmptySet + + # Systems of three equations: + assert _solveset_multi([x+y+z-1, x+y-z-2, x-y-z-3], [x, y, z], [Reals, + Reals, Reals]) == FiniteSet((2, -S.Half, -S.Half)) + + # Nonlinear systems: + from sympy.abc import theta + assert _solveset_multi([x**2+y**2-2, x+y], [x, y], [Reals, Reals]) == FiniteSet((-1, 1), (1, -1)) + assert _solveset_multi([x**2-1, y], [x, y], [Reals, Reals]) == FiniteSet((1, 0), (-1, 0)) + #assert _solveset_multi([x**2-y**2], [x, y], [Reals, Reals]) == Union( + # ImageSet(Lambda(x, (x, -x)), Reals), ImageSet(Lambda(x, (x, x)), Reals)) + assert dumeq(_solveset_multi([x**2-y**2], [x, y], [Reals, Reals]), Union( + ImageSet(Lambda(((x,),), (x, -Abs(x))), ProductSet(Reals)), + ImageSet(Lambda(((x,),), (x, Abs(x))), ProductSet(Reals)), + ImageSet(Lambda(((y,),), (-Abs(y), y)), ProductSet(Reals)), + ImageSet(Lambda(((y,),), (Abs(y), y)), ProductSet(Reals)))) + assert _solveset_multi([r*cos(theta)-1, r*sin(theta)], [theta, r], + [Interval(0, pi), Interval(-1, 1)]) == FiniteSet((0, 1), (pi, -1)) + assert _solveset_multi([r*cos(theta)-1, r*sin(theta)], [r, theta], + [Interval(0, 1), Interval(0, pi)]) == FiniteSet((1, 0)) + assert _solveset_multi([r*cos(theta)-r, r*sin(theta)], [r, theta], + [Interval(0, 1), Interval(0, pi)]) == Union( + ImageSet(Lambda(((r,),), (r, 0)), + ImageSet(Lambda(r, (r,)), Interval(0, 1))), + ImageSet(Lambda(((theta,),), (0, theta)), + ImageSet(Lambda(theta, (theta,)), Interval(0, pi)))) + + +def test_conditionset(): + assert solveset(Eq(sin(x)**2 + cos(x)**2, 1), x, domain=S.Reals + ) is S.Reals + + assert solveset(Eq(x**2 + x*sin(x), 1), x, domain=S.Reals + ).dummy_eq(ConditionSet(x, Eq(x**2 + x*sin(x) - 1, 0), S.Reals)) + + assert dumeq(solveset(Eq(-I*(exp(I*x) - exp(-I*x))/2, 1), x + ), imageset(Lambda(n, 2*n*pi + pi/2), S.Integers)) + + assert solveset(x + sin(x) > 1, x, domain=S.Reals + ).dummy_eq(ConditionSet(x, x + sin(x) > 1, S.Reals)) + + assert solveset(Eq(sin(Abs(x)), x), x, domain=S.Reals + ).dummy_eq(ConditionSet(x, Eq(-x + sin(Abs(x)), 0), S.Reals)) + + assert solveset(y**x-z, x, S.Reals + ).dummy_eq(ConditionSet(x, Eq(y**x - z, 0), S.Reals)) + + +@XFAIL +def test_conditionset_equality(): + ''' Checking equality of different representations of ConditionSet''' + assert solveset(Eq(tan(x), y), x) == ConditionSet(x, Eq(tan(x), y), S.Complexes) + + +def test_solveset_domain(): + assert solveset(x**2 - x - 6, x, Interval(0, oo)) == FiniteSet(3) + assert solveset(x**2 - 1, x, Interval(0, oo)) == FiniteSet(1) + assert solveset(x**4 - 16, x, Interval(0, 10)) == FiniteSet(2) + + +def test_improve_coverage(): + solution = solveset(exp(x) + sin(x), x, S.Reals) + unsolved_object = ConditionSet(x, Eq(exp(x) + sin(x), 0), S.Reals) + assert solution.dummy_eq(unsolved_object) + + +def test_issue_9522(): + expr1 = Eq(1/(x**2 - 4) + x, 1/(x**2 - 4) + 2) + expr2 = Eq(1/x + x, 1/x) + + assert solveset(expr1, x, S.Reals) is S.EmptySet + assert solveset(expr2, x, S.Reals) is S.EmptySet + + +def test_solvify(): + assert solvify(x**2 + 10, x, S.Reals) == [] + assert solvify(x**3 + 1, x, S.Complexes) == [-1, S.Half - sqrt(3)*I/2, + S.Half + sqrt(3)*I/2] + assert solvify(log(x), x, S.Reals) == [1] + assert solvify(cos(x), x, S.Reals) == [pi/2, pi*Rational(3, 2)] + assert solvify(sin(x) + 1, x, S.Reals) == [pi*Rational(3, 2)] + raises(NotImplementedError, lambda: solvify(sin(exp(x)), x, S.Complexes)) + + +def test_solvify_piecewise(): + p1 = Piecewise((0, x < -1), (x**2, x <= 1), (log(x), True)) + p2 = Piecewise((0, x < -10), (x**2 + 5*x - 6, x >= -9)) + p3 = Piecewise((0, Eq(x, 0)), (x**2/Abs(x), True)) + p4 = Piecewise((0, Eq(x, pi)), ((x - pi)/sin(x), True)) + + # issue 21079 + assert solvify(p1, x, S.Reals) == [0] + assert solvify(p2, x, S.Reals) == [-6, 1] + assert solvify(p3, x, S.Reals) == [0] + assert solvify(p4, x, S.Reals) == [pi] + + +def test_abs_invert_solvify(): + + x = Symbol('x',positive=True) + assert solvify(sin(Abs(x)), x, S.Reals) == [0, pi] + x = Symbol('x') + assert solvify(sin(Abs(x)), x, S.Reals) is None + + +def test_linear_eq_to_matrix(): + assert linear_eq_to_matrix(0, x) == (Matrix([[0]]), Matrix([[0]])) + assert linear_eq_to_matrix(1, x) == (Matrix([[0]]), Matrix([[-1]])) + + # integer coefficients + eqns1 = [2*x + y - 2*z - 3, x - y - z, x + y + 3*z - 12] + eqns2 = [Eq(3*x + 2*y - z, 1), Eq(2*x - 2*y + 4*z, -2), -2*x + y - 2*z] + + A, B = linear_eq_to_matrix(eqns1, x, y, z) + assert A == Matrix([[2, 1, -2], [1, -1, -1], [1, 1, 3]]) + assert B == Matrix([[3], [0], [12]]) + + A, B = linear_eq_to_matrix(eqns2, x, y, z) + assert A == Matrix([[3, 2, -1], [2, -2, 4], [-2, 1, -2]]) + assert B == Matrix([[1], [-2], [0]]) + + # Pure symbolic coefficients + eqns3 = [a*b*x + b*y + c*z - d, e*x + d*x + f*y + g*z - h, i*x + j*y + k*z - l] + A, B = linear_eq_to_matrix(eqns3, x, y, z) + assert A == Matrix([[a*b, b, c], [d + e, f, g], [i, j, k]]) + assert B == Matrix([[d], [h], [l]]) + + # raise Errors if + # 1) no symbols are given + raises(ValueError, lambda: linear_eq_to_matrix(eqns3)) + # 2) there are duplicates + raises(ValueError, lambda: linear_eq_to_matrix(eqns3, [x, x, y])) + # 3) a nonlinear term is detected in the original expression + raises(NonlinearError, lambda: linear_eq_to_matrix(Eq(1/x + x, 1/x), [x])) + raises(NonlinearError, lambda: linear_eq_to_matrix([x**2], [x])) + raises(NonlinearError, lambda: linear_eq_to_matrix([x*y], [x, y])) + # 4) Eq being used to represent equations autoevaluates + # (use unevaluated Eq instead) + raises(ValueError, lambda: linear_eq_to_matrix(Eq(x, x), x)) + raises(ValueError, lambda: linear_eq_to_matrix(Eq(x, x + 1), x)) + + + # if non-symbols are passed, the user is responsible for interpreting + assert linear_eq_to_matrix([x], [1/x]) == (Matrix([[0]]), Matrix([[-x]])) + + # issue 15195 + assert linear_eq_to_matrix(x + y*(z*(3*x + 2) + 3), x) == ( + Matrix([[3*y*z + 1]]), Matrix([[-y*(2*z + 3)]])) + assert linear_eq_to_matrix(Matrix( + [[a*x + b*y - 7], [5*x + 6*y - c]]), x, y) == ( + Matrix([[a, b], [5, 6]]), Matrix([[7], [c]])) + + # issue 15312 + assert linear_eq_to_matrix(Eq(x + 2, 1), x) == ( + Matrix([[1]]), Matrix([[-1]])) + + # issue 25423 + raises(TypeError, lambda: linear_eq_to_matrix([], {x, y})) + raises(TypeError, lambda: linear_eq_to_matrix([x + y], {x, y})) + raises(ValueError, lambda: linear_eq_to_matrix({x + y}, (x, y))) + + +def test_issue_16577(): + assert linear_eq_to_matrix(Eq(a*(2*x + 3*y) + 4*y, 5), x, y) == ( + Matrix([[2*a, 3*a + 4]]), Matrix([[5]])) + + +def test_issue_10085(): + assert invert_real(exp(x),0,x) == (x, S.EmptySet) + + +def test_linsolve(): + x1, x2, x3, x4 = symbols('x1, x2, x3, x4') + + # Test for different input forms + + M = Matrix([[1, 2, 1, 1, 7], [1, 2, 2, -1, 12], [2, 4, 0, 6, 4]]) + system1 = A, B = M[:, :-1], M[:, -1] + Eqns = [x1 + 2*x2 + x3 + x4 - 7, x1 + 2*x2 + 2*x3 - x4 - 12, + 2*x1 + 4*x2 + 6*x4 - 4] + + sol = FiniteSet((-2*x2 - 3*x4 + 2, x2, 2*x4 + 5, x4)) + assert linsolve(Eqns, (x1, x2, x3, x4)) == sol + assert linsolve(Eqns, *(x1, x2, x3, x4)) == sol + assert linsolve(system1, (x1, x2, x3, x4)) == sol + assert linsolve(system1, *(x1, x2, x3, x4)) == sol + # issue 9667 - symbols can be Dummy symbols + x1, x2, x3, x4 = symbols('x:4', cls=Dummy) + assert linsolve(system1, x1, x2, x3, x4) == FiniteSet( + (-2*x2 - 3*x4 + 2, x2, 2*x4 + 5, x4)) + + # raise ValueError for garbage value + raises(ValueError, lambda: linsolve(Eqns)) + raises(ValueError, lambda: linsolve(x1)) + raises(ValueError, lambda: linsolve(x1, x2)) + raises(ValueError, lambda: linsolve((A,), x1, x2)) + raises(ValueError, lambda: linsolve(A, B, x1, x2)) + raises(ValueError, lambda: linsolve([x1], x1, x1)) + raises(ValueError, lambda: linsolve([x1], (i for i in (x1, x1)))) + + #raise ValueError if equations are non-linear in given variables + raises(NonlinearError, lambda: linsolve([x + y - 1, x ** 2 + y - 3], [x, y])) + raises(NonlinearError, lambda: linsolve([cos(x) + y, x + y], [x, y])) + assert linsolve([x + z - 1, x ** 2 + y - 3], [z, y]) == {(-x + 1, -x**2 + 3)} + + # Fully symbolic test + A = Matrix([[a, b], [c, d]]) + B = Matrix([[e], [g]]) + system2 = (A, B) + sol = FiniteSet(((-b*g + d*e)/(a*d - b*c), (a*g - c*e)/(a*d - b*c))) + assert linsolve(system2, [x, y]) == sol + + # No solution + A = Matrix([[1, 2, 3], [2, 4, 6], [3, 6, 9]]) + B = Matrix([0, 0, 1]) + assert linsolve((A, B), (x, y, z)) is S.EmptySet + + # Issue #10056 + A, B, J1, J2 = symbols('A B J1 J2') + Augmatrix = Matrix([ + [2*I*J1, 2*I*J2, -2/J1], + [-2*I*J2, -2*I*J1, 2/J2], + [0, 2, 2*I/(J1*J2)], + [2, 0, 0], + ]) + + assert linsolve(Augmatrix, A, B) == FiniteSet((0, I/(J1*J2))) + + # Issue #10121 - Assignment of free variables + Augmatrix = Matrix([[0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0]]) + assert linsolve(Augmatrix, a, b, c, d, e) == FiniteSet((a, 0, c, 0, e)) + #raises(IndexError, lambda: linsolve(Augmatrix, a, b, c)) + + x0, x1, x2, _x0 = symbols('tau0 tau1 tau2 _tau0') + assert linsolve(Matrix([[0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, _x0]]) + ) == FiniteSet((x0, 0, x1, _x0, x2)) + x0, x1, x2, _x0 = symbols('tau00 tau01 tau02 tau0') + assert linsolve(Matrix([[0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, _x0]]) + ) == FiniteSet((x0, 0, x1, _x0, x2)) + x0, x1, x2, _x0 = symbols('tau00 tau01 tau02 tau1') + assert linsolve(Matrix([[0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, _x0]]) + ) == FiniteSet((x0, 0, x1, _x0, x2)) + # symbols can be given as generators + x0, x2, x4 = symbols('x0, x2, x4') + assert linsolve(Augmatrix, numbered_symbols('x') + ) == FiniteSet((x0, 0, x2, 0, x4)) + Augmatrix[-1, -1] = x0 + # use Dummy to avoid clash; the names may clash but the symbols + # will not + Augmatrix[-1, -1] = symbols('_x0') + assert len(linsolve( + Augmatrix, numbered_symbols('x', cls=Dummy)).free_symbols) == 4 + + # Issue #12604 + f = Function('f') + assert linsolve([f(x) - 5], f(x)) == FiniteSet((5,)) + + # Issue #14860 + from sympy.physics.units import meter, newton, kilo + kN = kilo*newton + Eqns = [8*kN + x + y, 28*kN*meter + 3*x*meter] + assert linsolve(Eqns, x, y) == { + (kilo*newton*Rational(-28, 3), kN*Rational(4, 3))} + + # linsolve does not allow expansion (real or implemented) + # to remove singularities, but it will cancel linear terms + assert linsolve([Eq(x, x + y)], [x, y]) == {(x, 0)} + assert linsolve([Eq(x + x*y, 1 + y)], [x]) == {(1,)} + assert linsolve([Eq(1 + y, x + x*y)], [x]) == {(1,)} + raises(NonlinearError, lambda: + linsolve([Eq(x**2, x**2 + y)], [x, y])) + + # corner cases + # + # XXX: The case below should give the same as for [0] + # assert linsolve([], [x]) == {(x,)} + assert linsolve([], [x]) is S.EmptySet + assert linsolve([0], [x]) == {(x,)} + assert linsolve([x], [x, y]) == {(0, y)} + assert linsolve([x, 0], [x, y]) == {(0, y)} + + +def test_linsolve_large_sparse(): + # + # This is mainly a performance test + # + + def _mk_eqs_sol(n): + xs = symbols('x:{}'.format(n)) + ys = symbols('y:{}'.format(n)) + syms = xs + ys + eqs = [] + sol = (-S.Half,) * n + (S.Half,) * n + for xi, yi in zip(xs, ys): + eqs.extend([xi + yi, xi - yi + 1]) + return eqs, syms, FiniteSet(sol) + + n = 500 + eqs, syms, sol = _mk_eqs_sol(n) + assert linsolve(eqs, syms) == sol + + +def test_linsolve_immutable(): + A = ImmutableDenseMatrix([[1, 1, 2], [0, 1, 2], [0, 0, 1]]) + B = ImmutableDenseMatrix([2, 1, -1]) + assert linsolve([A, B], (x, y, z)) == FiniteSet((1, 3, -1)) + + A = ImmutableDenseMatrix([[1, 1, 7], [1, -1, 3]]) + assert linsolve(A) == FiniteSet((5, 2)) + + +def test_solve_decomposition(): + n = Dummy('n') + + f1 = exp(3*x) - 6*exp(2*x) + 11*exp(x) - 6 + f2 = sin(x)**2 - 2*sin(x) + 1 + f3 = sin(x)**2 - sin(x) + f4 = sin(x + 1) + f5 = exp(x + 2) - 1 + f6 = 1/log(x) + f7 = 1/x + + s1 = ImageSet(Lambda(n, 2*n*pi), S.Integers) + s2 = ImageSet(Lambda(n, 2*n*pi + pi), S.Integers) + s3 = ImageSet(Lambda(n, 2*n*pi + pi/2), S.Integers) + s4 = ImageSet(Lambda(n, 2*n*pi - 1), S.Integers) + s5 = ImageSet(Lambda(n, 2*n*pi - 1 + pi), S.Integers) + + assert solve_decomposition(f1, x, S.Reals) == FiniteSet(0, log(2), log(3)) + assert dumeq(solve_decomposition(f2, x, S.Reals), s3) + assert dumeq(solve_decomposition(f3, x, S.Reals), Union(s1, s2, s3)) + assert dumeq(solve_decomposition(f4, x, S.Reals), Union(s4, s5)) + assert solve_decomposition(f5, x, S.Reals) == FiniteSet(-2) + assert solve_decomposition(f6, x, S.Reals) == S.EmptySet + assert solve_decomposition(f7, x, S.Reals) == S.EmptySet + assert solve_decomposition(x, x, Interval(1, 2)) == S.EmptySet + + +# nonlinsolve testcases +def test_nonlinsolve_basic(): + assert nonlinsolve([],[]) == S.EmptySet + assert nonlinsolve([],[x, y]) == S.EmptySet + + system = [x, y - x - 5] + assert nonlinsolve([x],[x, y]) == FiniteSet((0, y)) + assert nonlinsolve(system, [y]) == S.EmptySet + soln = (ImageSet(Lambda(n, 2*n*pi + pi/2), S.Integers),) + assert dumeq(nonlinsolve([sin(x) - 1], [x]), FiniteSet(tuple(soln))) + soln = ((ImageSet(Lambda(n, 2*n*pi + pi), S.Integers), 1), + (ImageSet(Lambda(n, 2*n*pi), S.Integers), 1)) + assert dumeq(nonlinsolve([sin(x), y - 1], [x, y]), FiniteSet(*soln)) + assert nonlinsolve([x**2 - 1], [x]) == FiniteSet((-1,), (1,)) + + soln = FiniteSet((y, y)) + assert nonlinsolve([x - y, 0], x, y) == soln + assert nonlinsolve([0, x - y], x, y) == soln + assert nonlinsolve([x - y, x - y], x, y) == soln + assert nonlinsolve([x, 0], x, y) == FiniteSet((0, y)) + f = Function('f') + assert nonlinsolve([f(x), 0], f(x), y) == FiniteSet((0, y)) + assert nonlinsolve([f(x), 0], f(x), f(y)) == FiniteSet((0, f(y))) + A = Indexed('A', x) + assert nonlinsolve([A, 0], A, y) == FiniteSet((0, y)) + assert nonlinsolve([x**2 -1], [sin(x)]) == FiniteSet((S.EmptySet,)) + assert nonlinsolve([x**2 -1], sin(x)) == FiniteSet((S.EmptySet,)) + assert nonlinsolve([x**2 -1], 1) == FiniteSet((x**2,)) + assert nonlinsolve([x**2 -1], x + y) == FiniteSet((S.EmptySet,)) + assert nonlinsolve([Eq(1, x + y), Eq(1, -x + y - 1), Eq(1, -x + y - 1)], x, y) == FiniteSet( + (-S.Half, 3*S.Half)) + + +def test_nonlinsolve_abs(): + soln = FiniteSet((y, y), (-y, y)) + assert nonlinsolve([Abs(x) - y], x, y) == soln + + +def test_raise_exception_nonlinsolve(): + raises(IndexError, lambda: nonlinsolve([x**2 -1], [])) + raises(ValueError, lambda: nonlinsolve([x**2 -1])) + + +def test_trig_system(): + # TODO: add more simple testcases when solveset returns + # simplified soln for Trig eq + assert nonlinsolve([sin(x) - 1, cos(x) -1 ], x) == S.EmptySet + soln1 = (ImageSet(Lambda(n, 2*n*pi + pi/2), S.Integers),) + soln = FiniteSet(soln1) + assert dumeq(nonlinsolve([sin(x) - 1, cos(x)], x), soln) + + +@XFAIL +def test_trig_system_fail(): + # fails because solveset trig solver is not much smart. + sys = [x + y - pi/2, sin(x) + sin(y) - 1] + # solveset returns conditionset for sin(x) + sin(y) - 1 + soln_1 = (ImageSet(Lambda(n, n*pi + pi/2), S.Integers), + ImageSet(Lambda(n, n*pi), S.Integers)) + soln_1 = FiniteSet(soln_1) + soln_2 = (ImageSet(Lambda(n, n*pi), S.Integers), + ImageSet(Lambda(n, n*pi+ pi/2), S.Integers)) + soln_2 = FiniteSet(soln_2) + soln = soln_1 + soln_2 + assert dumeq(nonlinsolve(sys, [x, y]), soln) + + # Add more cases from here + # http://www.vitutor.com/geometry/trigonometry/equations_systems.html#uno + sys = [sin(x) + sin(y) - (sqrt(3)+1)/2, sin(x) - sin(y) - (sqrt(3) - 1)/2] + soln_x = Union(ImageSet(Lambda(n, 2*n*pi + pi/3), S.Integers), + ImageSet(Lambda(n, 2*n*pi + pi*Rational(2, 3)), S.Integers)) + soln_y = Union(ImageSet(Lambda(n, 2*n*pi + pi/6), S.Integers), + ImageSet(Lambda(n, 2*n*pi + pi*Rational(5, 6)), S.Integers)) + assert dumeq(nonlinsolve(sys, [x, y]), FiniteSet((soln_x, soln_y))) + + +def test_nonlinsolve_positive_dimensional(): + x, y, a, b, c, d = symbols('x, y, a, b, c, d', extended_real=True) + assert nonlinsolve([x*y, x*y - x], [x, y]) == FiniteSet((0, y)) + + system = [a**2 + a*c, a - b] + assert nonlinsolve(system, [a, b]) == FiniteSet((0, 0), (-c, -c)) + # here (a= 0, b = 0) is independent soln so both is printed. + # if symbols = [a, b, c] then only {a : -c ,b : -c} + + eq1 = a + b + c + d + eq2 = a*b + b*c + c*d + d*a + eq3 = a*b*c + b*c*d + c*d*a + d*a*b + eq4 = a*b*c*d - 1 + system = [eq1, eq2, eq3, eq4] + sol1 = (-1/d, -d, 1/d, FiniteSet(d) - FiniteSet(0)) + sol2 = (1/d, -d, -1/d, FiniteSet(d) - FiniteSet(0)) + soln = FiniteSet(sol1, sol2) + assert nonlinsolve(system, [a, b, c, d]) == soln + + assert nonlinsolve([x**4 - 3*x**2 + y*x, x*z**2, y*z - 1], [x, y, z]) == \ + {(0, 1/z, z)} + + +def test_nonlinsolve_polysys(): + x, y, z = symbols('x, y, z', real=True) + assert nonlinsolve([x**2 + y - 2, x**2 + y], [x, y]) == S.EmptySet + + s = (-y + 2, y) + assert nonlinsolve([(x + y)**2 - 4, x + y - 2], [x, y]) == FiniteSet(s) + + system = [x**2 - y**2] + soln_real = FiniteSet((-y, y), (y, y)) + soln_complex = FiniteSet((-Abs(y), y), (Abs(y), y)) + soln =soln_real + soln_complex + assert nonlinsolve(system, [x, y]) == soln + + system = [x**2 - y**2] + soln_real= FiniteSet((y, -y), (y, y)) + soln_complex = FiniteSet((y, -Abs(y)), (y, Abs(y))) + soln = soln_real + soln_complex + assert nonlinsolve(system, [y, x]) == soln + + system = [x**2 + y - 3, x - y - 4] + assert nonlinsolve(system, (x, y)) != nonlinsolve(system, (y, x)) + + assert nonlinsolve([-x**2 - y**2 + z, -2*x, -2*y, S.One], [x, y, z]) == S.EmptySet + assert nonlinsolve([x + y + z, S.One, S.One, S.One], [x, y, z]) == S.EmptySet + + system = [-x**2*z**2 + x*y*z + y**4, -2*x*z**2 + y*z, x*z + 4*y**3, -2*x**2*z + x*y] + assert nonlinsolve(system, [x, y, z]) == FiniteSet((0, 0, z), (x, 0, 0)) + + +def test_nonlinsolve_using_substitution(): + x, y, z, n = symbols('x, y, z, n', real = True) + system = [(x + y)*n - y**2 + 2] + s_x = (n*y - y**2 + 2)/n + soln = (-s_x, y) + assert nonlinsolve(system, [x, y]) == FiniteSet(soln) + + system = [z**2*x**2 - z**2*y**2/exp(x)] + soln_real_1 = (y, x, 0) + soln_real_2 = (-exp(x/2)*Abs(x), x, z) + soln_real_3 = (exp(x/2)*Abs(x), x, z) + soln_complex_1 = (-x*exp(x/2), x, z) + soln_complex_2 = (x*exp(x/2), x, z) + syms = [y, x, z] + soln = FiniteSet(soln_real_1, soln_complex_1, soln_complex_2,\ + soln_real_2, soln_real_3) + assert nonlinsolve(system,syms) == soln + + +def test_nonlinsolve_complex(): + n = Dummy('n') + assert dumeq(nonlinsolve([exp(x) - sin(y), 1/y - 3], [x, y]), { + (ImageSet(Lambda(n, 2*n*I*pi + log(sin(Rational(1, 3)))), S.Integers), Rational(1, 3))}) + + system = [exp(x) - sin(y), 1/exp(y) - 3] + assert dumeq(nonlinsolve(system, [x, y]), { + (ImageSet(Lambda(n, I*(2*n*pi + pi) + + log(sin(log(3)))), S.Integers), -log(3)), + (ImageSet(Lambda(n, I*(2*n*pi + arg(sin(2*n*I*pi - log(3)))) + + log(Abs(sin(2*n*I*pi - log(3))))), S.Integers), + ImageSet(Lambda(n, 2*n*I*pi - log(3)), S.Integers))}) + + system = [exp(x) - sin(y), y**2 - 4] + assert dumeq(nonlinsolve(system, [x, y]), { + (ImageSet(Lambda(n, I*(2*n*pi + pi) + log(sin(2))), S.Integers), -2), + (ImageSet(Lambda(n, 2*n*I*pi + log(sin(2))), S.Integers), 2)}) + + system = [exp(x) - 2, y ** 2 - 2] + assert dumeq(nonlinsolve(system, [x, y]), { + (log(2), -sqrt(2)), (log(2), sqrt(2)), + (ImageSet(Lambda(n, 2*n*I*pi + log(2)), S.Integers), -sqrt(2)), + (ImageSet(Lambda(n, 2 * n * I * pi + log(2)), S.Integers), sqrt(2))}) + + +def test_nonlinsolve_radical(): + assert nonlinsolve([sqrt(y) - x - z, y - 1], [x, y, z]) == {(1 - z, 1, z)} + + +def test_nonlinsolve_inexact(): + sol = [(-1.625, -1.375), (1.625, 1.375)] + res = nonlinsolve([(x + y)**2 - 9, x**2 - y**2 - 0.75], [x, y]) + assert all(abs(res.args[i][j]-sol[i][j]) < 1e-9 + for i in range(2) for j in range(2)) + + assert nonlinsolve([(x + y)**2 - 9, (x + y)**2 - 0.75], [x, y]) == S.EmptySet + + assert nonlinsolve([y**2 + (x - 0.5)**2 - 0.0625, 2*x - 1.0, 2*y], [x, y]) == \ + S.EmptySet + + res = nonlinsolve([x**2 + y - 0.5, (x + y)**2, log(z)], [x, y, z]) + sol = [(-0.366025403784439, 0.366025403784439, 1), + (-0.366025403784439, 0.366025403784439, 1), + (1.36602540378444, -1.36602540378444, 1)] + assert all(abs(res.args[i][j]-sol[i][j]) < 1e-9 + for i in range(3) for j in range(3)) + + res = nonlinsolve([y - x**2, x**5 - x + 1.0], [x, y]) + sol = [(-1.16730397826142, 1.36259857766493), + (-0.181232444469876 - 1.08395410131771*I, + -1.14211129483496 + 0.392895302949911*I), + (-0.181232444469876 + 1.08395410131771*I, + -1.14211129483496 - 0.392895302949911*I), + (0.764884433600585 - 0.352471546031726*I, + 0.460812006002492 - 0.539199997693599*I), + (0.764884433600585 + 0.352471546031726*I, + 0.460812006002492 + 0.539199997693599*I)] + assert all(abs(res.args[i][j] - sol[i][j]) < 1e-9 + for i in range(5) for j in range(2)) + +@XFAIL +def test_solve_nonlinear_trans(): + # After the transcendental equation solver these will work + x, y = symbols('x, y', real=True) + soln1 = FiniteSet((2*LambertW(y/2), y)) + soln2 = FiniteSet((-x*sqrt(exp(x)), y), (x*sqrt(exp(x)), y)) + soln3 = FiniteSet((x*exp(x/2), x)) + soln4 = FiniteSet(2*LambertW(y/2), y) + assert nonlinsolve([x**2 - y**2/exp(x)], [x, y]) == soln1 + assert nonlinsolve([x**2 - y**2/exp(x)], [y, x]) == soln2 + assert nonlinsolve([x**2 - y**2/exp(x)], [y, x]) == soln3 + assert nonlinsolve([x**2 - y**2/exp(x)], [x, y]) == soln4 + + +def test_nonlinsolve_issue_25182(): + a1, b1, c1, ca, cb, cg = symbols('a1, b1, c1, ca, cb, cg') + eq1 = a1*a1 + b1*b1 - 2.*a1*b1*cg - c1*c1 + eq2 = a1*a1 + c1*c1 - 2.*a1*c1*cb - b1*b1 + eq3 = b1*b1 + c1*c1 - 2.*b1*c1*ca - a1*a1 + assert nonlinsolve([eq1, eq2, eq3], [c1, cb, cg]) == FiniteSet( + (1.0*b1*ca - 1.0*sqrt(a1**2 + b1**2*ca**2 - b1**2), + -1.0*sqrt(a1**2 + b1**2*ca**2 - b1**2)/a1, + -1.0*b1*(ca - 1)*(ca + 1)/a1 + 1.0*ca*sqrt(a1**2 + b1**2*ca**2 - b1**2)/a1), + (1.0*b1*ca + 1.0*sqrt(a1**2 + b1**2*ca**2 - b1**2), + 1.0*sqrt(a1**2 + b1**2*ca**2 - b1**2)/a1, + -1.0*b1*(ca - 1)*(ca + 1)/a1 - 1.0*ca*sqrt(a1**2 + b1**2*ca**2 - b1**2)/a1)) + + +def test_issue_14642(): + x = Symbol('x') + n1 = 0.5*x**3+x**2+0.5+I #add I in the Polynomials + solution = solveset(n1, x) + assert abs(solution.args[0] - (-2.28267560928153 - 0.312325580497716*I)) <= 1e-9 + assert abs(solution.args[1] - (-0.297354141679308 + 1.01904778618762*I)) <= 1e-9 + assert abs(solution.args[2] - (0.580029750960839 - 0.706722205689907*I)) <= 1e-9 + + # Symbolic + n1 = S.Half*x**3+x**2+S.Half+I + res = FiniteSet(-((3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49) + /2)/2)**2)**(S(1)/6)*cos(atan((27 + 3*sqrt(3)*31985**(S(1)/4)* + cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan( + S(172)/49)/2)/2 + S(43)/2))/3)/3 - S(2)/3 - 4*cos(atan((27 + + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)* + 31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + S(43)/2))/3)/(3*((3* + sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + S(43)/2)**2 + + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2)/2)**2)**(S(1)/ + 6)) + I*(-((3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/ + 2)/2)**2)**(S(1)/6)*sin(atan((27 + 3*sqrt(3)*31985**(S(1)/4)*cos( + atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49) + /2)/2 + S(43)/2))/3)/3 + 4*sin(atan((27 + 3*sqrt(3)*31985**(S(1)/4)* + cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172) + /49)/2)/2 + S(43)/2))/3)/(3*((3*sqrt(3)*31985**(S(1)/4)*sin(atan( + S(172)/49)/2)/2 + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)* + cos(atan(S(172)/49)/2)/2)**2)**(S(1)/6))), -S(2)/3 - sqrt(3)*((3* + sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + S(43)/2)**2 + + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2)/2)**2)**(S(1) + /6)*sin(atan((27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2) + /2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + S(43)/2)) + /3)/6 - 4*re(1/((-S(1)/2 - sqrt(3)*I/2)*(S(43)/2 + 27*I + sqrt(-256 + + (43 + 54*I)**2)/2)**(S(1)/3)))/3 + ((3*sqrt(3)*31985**(S(1)/4)*sin( + atan(S(172)/49)/2)/2 + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)* + cos(atan(S(172)/49)/2)/2)**2)**(S(1)/6)*cos(atan((27 + 3*sqrt(3)* + 31985**(S(1)/4)*cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)* + sin(atan(S(172)/49)/2)/2 + S(43)/2))/3)/6 + I*(-4*im(1/((-S(1)/2 - + sqrt(3)*I/2)*(S(43)/2 + 27*I + sqrt(-256 + (43 + 54*I)**2)/2)**(S(1)/ + 3)))/3 + ((3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2) + /2)**2)**(S(1)/6)*sin(atan((27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan( + S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2))/3)/6 + sqrt(3)*((3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/ + 49)/2)/2 + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan( + S(172)/49)/2)/2)**2)**(S(1)/6)*cos(atan((27 + 3*sqrt(3)*31985**(S(1)/ + 4)*cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan( + S(172)/49)/2)/2 + S(43)/2))/3)/6), -S(2)/3 - 4*re(1/((-S(1)/2 + + sqrt(3)*I/2)*(S(43)/2 + 27*I + sqrt(-256 + (43 + 54*I)**2)/2)**(S(1) + /3)))/3 + sqrt(3)*((3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2) + /2)**2)**(S(1)/6)*sin(atan((27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan( + S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2))/3)/6 + ((3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan(S(172)/49)/2) + /2)**2)**(S(1)/6)*cos(atan((27 + 3*sqrt(3)*31985**(S(1)/4)*cos(atan( + S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin(atan(S(172)/49)/2)/2 + + S(43)/2))/3)/6 + I*(-sqrt(3)*((3*sqrt(3)*31985**(S(1)/4)*sin(atan( + S(172)/49)/2)/2 + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)*cos( + atan(S(172)/49)/2)/2)**2)**(S(1)/6)*cos(atan((27 + 3*sqrt(3)*31985**( + S(1)/4)*cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin( + atan(S(172)/49)/2)/2 + S(43)/2))/3)/6 + ((3*sqrt(3)*31985**(S(1)/4)* + sin(atan(S(172)/49)/2)/2 + S(43)/2)**2 + (27 + 3*sqrt(3)*31985**(S(1)/4)* + cos(atan(S(172)/49)/2)/2)**2)**(S(1)/6)*sin(atan((27 + 3*sqrt(3)*31985**( + S(1)/4)*cos(atan(S(172)/49)/2)/2)/(3*sqrt(3)*31985**(S(1)/4)*sin( + atan(S(172)/49)/2)/2 + S(43)/2))/3)/6 - 4*im(1/((-S(1)/2 + sqrt(3)*I/2)* + (S(43)/2 + 27*I + sqrt(-256 + (43 + 54*I)**2)/2)**(S(1)/3)))/3)) + + assert solveset(n1, x) == res + + +def test_issue_13961(): + V = (ax, bx, cx, gx, jx, lx, mx, nx, q) = symbols('ax bx cx gx jx lx mx nx q') + S = (ax*q - lx*q - mx, ax - gx*q - lx, bx*q**2 + cx*q - jx*q - nx, q*(-ax*q + lx*q + mx), q*(-ax + gx*q + lx)) + + sol = FiniteSet((lx + mx/q, (-cx*q + jx*q + nx)/q**2, cx, mx/q**2, jx, lx, mx, nx, Complement({q}, {0})), + (lx + mx/q, (cx*q - jx*q - nx)/q**2*-1, cx, mx/q**2, jx, lx, mx, nx, Complement({q}, {0}))) + assert nonlinsolve(S, *V) == sol + # The two solutions are in fact identical, so even better if only one is returned + + +def test_issue_14541(): + solutions = solveset(sqrt(-x**2 - 2.0), x) + assert abs(solutions.args[0]+1.4142135623731*I) <= 1e-9 + assert abs(solutions.args[1]-1.4142135623731*I) <= 1e-9 + + +def test_issue_13396(): + expr = -2*y*exp(-x**2 - y**2)*Abs(x) + sol = FiniteSet(0) + + assert solveset(expr, y, domain=S.Reals) == sol + + # Related type of equation also solved here + assert solveset(atan(x**2 - y**2)-pi/2, y, S.Reals) is S.EmptySet + + +def test_issue_12032(): + sol = FiniteSet(-sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))/2 + + sqrt(Abs(-2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)) + + 2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2/sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))))/2, + -sqrt(Abs(-2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)) + + 2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2/sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))))/2 - + sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))/2, + sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))/2 - + I*sqrt(Abs(-2/sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) - + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)) + + 2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))))/2, + sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)))/2 + + I*sqrt(Abs(-2/sqrt(-2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) + + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3))) - + 2*(Rational(1, 16) + sqrt(849)/144)**(Rational(1, 3)) + + 2/(3*(Rational(1, 16) + sqrt(849)/144)**(Rational(1,3)))))/2) + assert solveset(x**4 + x - 1, x) == sol + + +def test_issue_10876(): + assert solveset(1/sqrt(x), x) == S.EmptySet + + +def test_issue_19050(): + # test_issue_19050 --> TypeError removed + assert dumeq(nonlinsolve([x + y, sin(y)], [x, y]), + FiniteSet((ImageSet(Lambda(n, -2*n*pi), S.Integers), ImageSet(Lambda(n, 2*n*pi), S.Integers)),\ + (ImageSet(Lambda(n, -2*n*pi - pi), S.Integers), ImageSet(Lambda(n, 2*n*pi + pi), S.Integers)))) + assert dumeq(nonlinsolve([x + y, sin(y) + cos(y)], [x, y]), + FiniteSet((ImageSet(Lambda(n, -2*n*pi - 3*pi/4), S.Integers), ImageSet(Lambda(n, 2*n*pi + 3*pi/4), S.Integers)), \ + (ImageSet(Lambda(n, -2*n*pi - 7*pi/4), S.Integers), ImageSet(Lambda(n, 2*n*pi + 7*pi/4), S.Integers)))) + + +def test_issue_16618(): + eqn = [sin(x)*sin(y), cos(x)*cos(y) - 1] + # nonlinsolve's answer is still suspicious since it contains only three + # distinct Dummys instead of 4. (Both 'x' ImageSets share the same Dummy.) + ans = FiniteSet((ImageSet(Lambda(n, 2*n*pi), S.Integers), ImageSet(Lambda(n, 2*n*pi), S.Integers)), + (ImageSet(Lambda(n, 2*n*pi + pi), S.Integers), ImageSet(Lambda(n, 2*n*pi + pi), S.Integers))) + sol = nonlinsolve(eqn, [x, y]) + + for i0, j0 in zip(ordered(sol), ordered(ans)): + assert len(i0) == len(j0) == 2 + assert all(a.dummy_eq(b) for a, b in zip(i0, j0)) + assert len(sol) == len(ans) + + +def test_issue_17566(): + assert nonlinsolve([32*(2**x)/2**(-y) - 4**y, 27*(3**x) - S(1)/3**y], x, y) ==\ + FiniteSet((-log(81)/log(3), 1)) + + +def test_issue_16643(): + n = Dummy('n') + assert solveset(x**2*sin(x), x).dummy_eq(Union(ImageSet(Lambda(n, 2*n*pi + pi), S.Integers), + ImageSet(Lambda(n, 2*n*pi), S.Integers))) + + +def test_issue_19587(): + n,m = symbols('n m') + assert nonlinsolve([32*2**m*2**n - 4**n, 27*3**m - 3**(-n)], m, n) ==\ + FiniteSet((-log(81)/log(3), 1)) + + +def test_issue_5132_1(): + system = [sqrt(x**2 + y**2) - sqrt(10), x + y - 4] + assert nonlinsolve(system, [x, y]) == FiniteSet((1, 3), (3, 1)) + + n = Dummy('n') + eqs = [exp(x)**2 - sin(y) + z**2, 1/exp(y) - 3] + s_real_y = -log(3) + s_real_z = sqrt(-exp(2*x) - sin(log(3))) + soln_real = FiniteSet((s_real_y, s_real_z), (s_real_y, -s_real_z)) + lam = Lambda(n, 2*n*I*pi + -log(3)) + s_complex_y = ImageSet(lam, S.Integers) + lam = Lambda(n, sqrt(-exp(2*x) + sin(2*n*I*pi + -log(3)))) + s_complex_z_1 = ImageSet(lam, S.Integers) + lam = Lambda(n, -sqrt(-exp(2*x) + sin(2*n*I*pi + -log(3)))) + s_complex_z_2 = ImageSet(lam, S.Integers) + soln_complex = FiniteSet( + (s_complex_y, s_complex_z_1), + (s_complex_y, s_complex_z_2) + ) + soln = soln_real + soln_complex + assert dumeq(nonlinsolve(eqs, [y, z]), soln) + + +def test_issue_5132_2(): + x, y = symbols('x, y', real=True) + eqs = [exp(x)**2 - sin(y) + z**2] + n = Dummy('n') + soln_real = (log(-z**2 + sin(y))/2, z) + lam = Lambda( n, I*(2*n*pi + arg(-z**2 + sin(y)))/2 + log(Abs(z**2 - sin(y)))/2) + img = ImageSet(lam, S.Integers) + # not sure about the complex soln. But it looks correct. + soln_complex = (img, z) + soln = FiniteSet(soln_real, soln_complex) + assert dumeq(nonlinsolve(eqs, [x, z]), soln) + + system = [r - x**2 - y**2, tan(t) - y/x] + s_x = sqrt(r/(tan(t)**2 + 1)) + s_y = sqrt(r/(tan(t)**2 + 1))*tan(t) + soln = FiniteSet((s_x, s_y), (-s_x, -s_y)) + assert nonlinsolve(system, [x, y]) == soln + + +def test_issue_6752(): + a, b = symbols('a, b', real=True) + assert nonlinsolve([a**2 + a, a - b], [a, b]) == {(-1, -1), (0, 0)} + + +@SKIP("slow") +def test_issue_5114_solveset(): + # slow testcase + from sympy.abc import o, p + + # there is no 'a' in the equation set but this is how the + # problem was originally posed + syms = [a, b, c, f, h, k, n] + eqs = [b + r/d - c/d, + c*(1/d + 1/e + 1/g) - f/g - r/d, + f*(1/g + 1/i + 1/j) - c/g - h/i, + h*(1/i + 1/l + 1/m) - f/i - k/m, + k*(1/m + 1/o + 1/p) - h/m - n/p, + n*(1/p + 1/q) - k/p] + assert len(nonlinsolve(eqs, syms)) == 1 + + +@SKIP("Hangs") +def _test_issue_5335(): + # Not able to check zero dimensional system. + # is_zero_dimensional Hangs + lam, a0, conc = symbols('lam a0 conc') + eqs = [lam + 2*y - a0*(1 - x/2)*x - 0.005*x/2*x, + a0*(1 - x/2)*x - 1*y - 0.743436700916726*y, + x + y - conc] + sym = [x, y, a0] + # there are 4 solutions but only two are valid + assert len(nonlinsolve(eqs, sym)) == 2 + # float + eqs = [lam + 2*y - a0*(1 - x/2)*x - 0.005*x/2*x, + a0*(1 - x/2)*x - 1*y - 0.743436700916726*y, + x + y - conc] + sym = [x, y, a0] + assert len(nonlinsolve(eqs, sym)) == 2 + + +def test_issue_2777(): + # the equations represent two circles + x, y = symbols('x y', real=True) + e1, e2 = sqrt(x**2 + y**2) - 10, sqrt(y**2 + (-x + 10)**2) - 3 + a, b = Rational(191, 20), 3*sqrt(391)/20 + ans = {(a, -b), (a, b)} + assert nonlinsolve((e1, e2), (x, y)) == ans + assert nonlinsolve((e1, e2/(x - a)), (x, y)) == S.EmptySet + # make the 2nd circle's radius be -3 + e2 += 6 + assert nonlinsolve((e1, e2), (x, y)) == S.EmptySet + + +def test_issue_8828(): + x1 = 0 + y1 = -620 + r1 = 920 + x2 = 126 + y2 = 276 + x3 = 51 + y3 = 205 + r3 = 104 + v = [x, y, z] + + f1 = (x - x1)**2 + (y - y1)**2 - (r1 - z)**2 + f2 = (x2 - x)**2 + (y2 - y)**2 - z**2 + f3 = (x - x3)**2 + (y - y3)**2 - (r3 - z)**2 + F = [f1, f2, f3] + + g1 = sqrt((x - x1)**2 + (y - y1)**2) + z - r1 + g2 = f2 + g3 = sqrt((x - x3)**2 + (y - y3)**2) + z - r3 + G = [g1, g2, g3] + + # both soln same + A = nonlinsolve(F, v) + B = nonlinsolve(G, v) + assert A == B + + +def test_nonlinsolve_conditionset(): + # when solveset failed to solve all the eq + # return conditionset + f = Function('f') + f1 = f(x) - pi/2 + f2 = f(y) - pi*Rational(3, 2) + intermediate_system = Eq(2*f(x) - pi, 0) & Eq(2*f(y) - 3*pi, 0) + syms = Tuple(x, y) + soln = ConditionSet( + syms, + intermediate_system, + S.Complexes**2) + assert nonlinsolve([f1, f2], [x, y]) == soln + + +def test_substitution_basic(): + assert substitution([], [x, y]) == S.EmptySet + assert substitution([], []) == S.EmptySet + system = [2*x**2 + 3*y**2 - 30, 3*x**2 - 2*y**2 - 19] + soln = FiniteSet((-3, -2), (-3, 2), (3, -2), (3, 2)) + assert substitution(system, [x, y]) == soln + + soln = FiniteSet((-1, 1)) + assert substitution([x + y], [x], [{y: 1}], [y], set(), [x, y]) == soln + assert substitution( + [x + y], [x], [{y: 1}], [y], + {x + 1}, [y, x]) == S.EmptySet + + +def test_substitution_incorrect(): + # the solutions in the following two tests are incorrect. The + # correct result is EmptySet in both cases. + assert substitution([h - 1, k - 1, f - 2, f - 4, -2 * k], + [h, k, f]) == {(1, 1, f)} + assert substitution([x + y + z, S.One, S.One, S.One], [x, y, z]) == \ + {(-y - z, y, z)} + + # the correct result in the test below is {(-I, I, I, -I), + # (I, -I, -I, I)} + assert substitution([a - d, b + d, c + d, d**2 + 1], [a, b, c, d]) == \ + {(d, -d, -d, d)} + + # the result in the test below is incomplete. The complete result + # is {(0, b), (log(2), 2)} + assert substitution([a*(a - log(b)), a*(b - 2)], [a, b]) == \ + {(0, b)} + + # The system in the test below is zero-dimensional, so the result + # should have no free symbols + assert substitution([-k*y + 6*x - 4*y, -81*k + 49*y**2 - 270, + -3*k*z + k + z**3, k**2 - 2*k + 4], + [x, y, z, k]).free_symbols == {z} + + +def test_substitution_redundant(): + # the third and fourth solutions are redundant in the test below + assert substitution([x**2 - y**2, z - 1], [x, z]) == \ + {(-y, 1), (y, 1), (-sqrt(y**2), 1), (sqrt(y**2), 1)} + + # the system below has three solutions. Two of the solutions + # returned by substitution are redundant. + res = substitution([x - y, y**3 - 3*y**2 + 1], [x, y]) + assert len(res) == 5 + + +def test_issue_5132_substitution(): + x, y, z, r, t = symbols('x, y, z, r, t', real=True) + system = [r - x**2 - y**2, tan(t) - y/x] + s_x_1 = Complement(FiniteSet(-sqrt(r/(tan(t)**2 + 1))), FiniteSet(0)) + s_x_2 = Complement(FiniteSet(sqrt(r/(tan(t)**2 + 1))), FiniteSet(0)) + s_y = sqrt(r/(tan(t)**2 + 1))*tan(t) + soln = FiniteSet((s_x_2, s_y)) + FiniteSet((s_x_1, -s_y)) + assert substitution(system, [x, y]) == soln + + n = Dummy('n') + eqs = [exp(x)**2 - sin(y) + z**2, 1/exp(y) - 3] + s_real_y = -log(3) + s_real_z = sqrt(-exp(2*x) - sin(log(3))) + soln_real = FiniteSet((s_real_y, s_real_z), (s_real_y, -s_real_z)) + lam = Lambda(n, 2*n*I*pi + -log(3)) + s_complex_y = ImageSet(lam, S.Integers) + lam = Lambda(n, sqrt(-exp(2*x) + sin(2*n*I*pi + -log(3)))) + s_complex_z_1 = ImageSet(lam, S.Integers) + lam = Lambda(n, -sqrt(-exp(2*x) + sin(2*n*I*pi + -log(3)))) + s_complex_z_2 = ImageSet(lam, S.Integers) + soln_complex = FiniteSet( + (s_complex_y, s_complex_z_1), + (s_complex_y, s_complex_z_2)) + soln = soln_real + soln_complex + assert dumeq(substitution(eqs, [y, z]), soln) + + +def test_raises_substitution(): + raises(ValueError, lambda: substitution([x**2 -1], [])) + raises(TypeError, lambda: substitution([x**2 -1])) + raises(ValueError, lambda: substitution([x**2 -1], [sin(x)])) + raises(TypeError, lambda: substitution([x**2 -1], x)) + raises(TypeError, lambda: substitution([x**2 -1], 1)) + + +def test_issue_21022(): + from sympy.core.sympify import sympify + + eqs = [ + 'k-16', + 'p-8', + 'y*y+z*z-x*x', + 'd - x + p', + 'd*d+k*k-y*y', + 'z*z-p*p-k*k', + 'abc-efg', + ] + efg = Symbol('efg') + eqs = [sympify(x) for x in eqs] + + syb = list(ordered(set.union(*[x.free_symbols for x in eqs]))) + res = nonlinsolve(eqs, syb) + + ans = FiniteSet( + (efg, 32, efg, 16, 8, 40, -16*sqrt(5), -8*sqrt(5)), + (efg, 32, efg, 16, 8, 40, -16*sqrt(5), 8*sqrt(5)), + (efg, 32, efg, 16, 8, 40, 16*sqrt(5), -8*sqrt(5)), + (efg, 32, efg, 16, 8, 40, 16*sqrt(5), 8*sqrt(5)), + ) + assert len(res) == len(ans) == 4 + assert res == ans + for result in res.args: + assert len(result) == 8 + + +def test_issue_17940(): + n = Dummy('n') + k1 = Dummy('k1') + sol = ImageSet(Lambda(((k1, n),), I*(2*k1*pi + arg(2*n*I*pi + log(5))) + + log(Abs(2*n*I*pi + log(5)))), + ProductSet(S.Integers, S.Integers)) + assert solveset(exp(exp(x)) - 5, x).dummy_eq(sol) + + +def test_issue_17906(): + assert solveset(7**(x**2 - 80) - 49**x, x) == FiniteSet(-8, 10) + + +@XFAIL +def test_issue_17933(): + eq1 = x*sin(45) - y*cos(q) + eq2 = x*cos(45) - y*sin(q) + eq3 = 9*x*sin(45)/10 + y*cos(q) + eq4 = 9*x*cos(45)/10 + y*sin(z) - z + assert nonlinsolve([eq1, eq2, eq3, eq4], x, y, z, q) ==\ + FiniteSet((0, 0, 0, q)) + +def test_issue_17933_bis(): + # nonlinsolve's result depends on the 'default_sort_key' ordering of + # the unknowns. + eq1 = x*sin(45) - y*cos(q) + eq2 = x*cos(45) - y*sin(q) + eq3 = 9*x*sin(45)/10 + y*cos(q) + eq4 = 9*x*cos(45)/10 + y*sin(z) - z + zz = Symbol('zz') + eqs = [e.subs(q, zz) for e in (eq1, eq2, eq3, eq4)] + assert nonlinsolve(eqs, x, y, z, zz) == FiniteSet((0, 0, 0, zz)) + + +def test_issue_14565(): + # removed redundancy + assert dumeq(nonlinsolve([k + m, k + m*exp(-2*pi*k)], [k, m]) , + FiniteSet((-n*I, ImageSet(Lambda(n, n*I), S.Integers)))) + + +# end of tests for nonlinsolve + + +def test_issue_9556(): + b = Symbol('b', positive=True) + + assert solveset(Abs(x) + 1, x, S.Reals) is S.EmptySet + assert solveset(Abs(x) + b, x, S.Reals) is S.EmptySet + assert solveset(Eq(b, -1), b, S.Reals) is S.EmptySet + + +def test_issue_9611(): + assert solveset(Eq(x - x + a, a), x, S.Reals) == S.Reals + assert solveset(Eq(y - y + a, a), y) == S.Complexes + + +def test_issue_9557(): + assert solveset(x**2 + a, x, S.Reals) == Intersection(S.Reals, + FiniteSet(-sqrt(-a), sqrt(-a))) + + +def test_issue_9778(): + x = Symbol('x', real=True) + y = Symbol('y', real=True) + assert solveset(x**3 + 1, x, S.Reals) == FiniteSet(-1) + assert solveset(x**Rational(3, 5) + 1, x, S.Reals) == S.EmptySet + assert solveset(x**3 + y, x, S.Reals) == \ + FiniteSet(-Abs(y)**Rational(1, 3)*sign(y)) + + +def test_issue_10214(): + assert solveset(x**Rational(3, 2) + 4, x, S.Reals) == S.EmptySet + assert solveset(x**(Rational(-3, 2)) + 4, x, S.Reals) == S.EmptySet + + ans = FiniteSet(-2**Rational(2, 3)) + assert solveset(x**(S(3)) + 4, x, S.Reals) == ans + assert (x**(S(3)) + 4).subs(x,list(ans)[0]) == 0 # substituting ans and verifying the result. + assert (x**(S(3)) + 4).subs(x,-(-2)**Rational(2, 3)) == 0 + + +def test_issue_9849(): + assert solveset(Abs(sin(x)) + 1, x, S.Reals) == S.EmptySet + + +def test_issue_9953(): + assert linsolve([ ], x) == S.EmptySet + + +def test_issue_9913(): + assert solveset(2*x + 1/(x - 10)**2, x, S.Reals) == \ + FiniteSet(-(3*sqrt(24081)/4 + Rational(4027, 4))**Rational(1, 3)/3 - 100/ + (3*(3*sqrt(24081)/4 + Rational(4027, 4))**Rational(1, 3)) + Rational(20, 3)) + + +def test_issue_10397(): + assert solveset(sqrt(x), x, S.Complexes) == FiniteSet(0) + + +def test_issue_14987(): + raises(ValueError, lambda: linear_eq_to_matrix( + [x**2], x)) + raises(ValueError, lambda: linear_eq_to_matrix( + [x*(-3/x + 1) + 2*y - a], [x, y])) + raises(ValueError, lambda: linear_eq_to_matrix( + [(x**2 - 3*x)/(x - 3) - 3], x)) + raises(ValueError, lambda: linear_eq_to_matrix( + [(x + 1)**3 - x**3 - 3*x**2 + 7], x)) + raises(ValueError, lambda: linear_eq_to_matrix( + [x*(1/x + 1) + y], [x, y])) + raises(ValueError, lambda: linear_eq_to_matrix( + [(x + 1)*y], [x, y])) + raises(ValueError, lambda: linear_eq_to_matrix( + [Eq(1/x, 1/x + y)], [x, y])) + raises(ValueError, lambda: linear_eq_to_matrix( + [Eq(y/x, y/x + y)], [x, y])) + raises(ValueError, lambda: linear_eq_to_matrix( + [Eq(x*(x + 1), x**2 + y)], [x, y])) + + +def test_simplification(): + eq = x + (a - b)/(-2*a + 2*b) + assert solveset(eq, x) == FiniteSet(S.Half) + assert solveset(eq, x, S.Reals) == Intersection({-((a - b)/(-2*a + 2*b))}, S.Reals) + # So that ap - bn is not zero: + ap = Symbol('ap', positive=True) + bn = Symbol('bn', negative=True) + eq = x + (ap - bn)/(-2*ap + 2*bn) + assert solveset(eq, x) == FiniteSet(S.Half) + assert solveset(eq, x, S.Reals) == FiniteSet(S.Half) + + +def test_integer_domain_relational(): + eq1 = 2*x + 3 > 0 + eq2 = x**2 + 3*x - 2 >= 0 + eq3 = x + 1/x > -2 + 1/x + eq4 = x + sqrt(x**2 - 5) > 0 + eq = x + 1/x > -2 + 1/x + eq5 = eq.subs(x,log(x)) + eq6 = log(x)/x <= 0 + eq7 = log(x)/x < 0 + eq8 = x/(x-3) < 3 + eq9 = x/(x**2-3) < 3 + + assert solveset(eq1, x, S.Integers) == Range(-1, oo, 1) + assert solveset(eq2, x, S.Integers) == Union(Range(-oo, -3, 1), Range(1, oo, 1)) + assert solveset(eq3, x, S.Integers) == Union(Range(-1, 0, 1), Range(1, oo, 1)) + assert solveset(eq4, x, S.Integers) == Range(3, oo, 1) + assert solveset(eq5, x, S.Integers) == Range(2, oo, 1) + assert solveset(eq6, x, S.Integers) == Range(1, 2, 1) + assert solveset(eq7, x, S.Integers) == S.EmptySet + assert solveset(eq8, x, domain=Range(0,5)) == Range(0, 3, 1) + assert solveset(eq9, x, domain=Range(0,5)) == Union(Range(0, 2, 1), Range(2, 5, 1)) + + # test_issue_19794 + assert solveset(x + 2 < 0, x, S.Integers) == Range(-oo, -2, 1) + + +def test_issue_10555(): + f = Function('f') + g = Function('g') + assert solveset(f(x) - pi/2, x, S.Reals).dummy_eq( + ConditionSet(x, Eq(f(x) - pi/2, 0), S.Reals)) + assert solveset(f(g(x)) - pi/2, g(x), S.Reals).dummy_eq( + ConditionSet(g(x), Eq(f(g(x)) - pi/2, 0), S.Reals)) + + +def test_issue_8715(): + eq = x + 1/x > -2 + 1/x + assert solveset(eq, x, S.Reals) == \ + (Interval.open(-2, oo) - FiniteSet(0)) + assert solveset(eq.subs(x,log(x)), x, S.Reals) == \ + Interval.open(exp(-2), oo) - FiniteSet(1) + + +def test_issue_11174(): + eq = z**2 + exp(2*x) - sin(y) + soln = Intersection(S.Reals, FiniteSet(log(-z**2 + sin(y))/2)) + assert solveset(eq, x, S.Reals) == soln + + eq = sqrt(r)*Abs(tan(t))/sqrt(tan(t)**2 + 1) + x*tan(t) + s = -sqrt(r)*Abs(tan(t))/(sqrt(tan(t)**2 + 1)*tan(t)) + soln = Intersection(S.Reals, FiniteSet(s)) + assert solveset(eq, x, S.Reals) == soln + + +def test_issue_11534(): + # eq1 and eq2 should not have the same solutions because squaring both + # sides of the radical equation introduces a spurious solution branch. + # The equations have a symbolic parameter y and it is easy to see that for + # y != 0 the solution s1 will not be valid for eq1. + x = Symbol('x', real=True) + y = Symbol('y', real=True) + eq1 = -y + x/sqrt(-x**2 + 1) + eq2 = -y**2 + x**2/(-x**2 + 1) + + # We get a ConditionSet here because s1 works in eq1 if y is equal to zero + # although not for any other value of y. That case is redundant though + # because if y=0 then s1=s2 so the solution for eq1 could just be returned + # as s2 - {-1, 1}. In fact we have + # |y/sqrt(y**2 + 1)| < 1 + # So the complements are not needed either. The ideal output here would be + # sol1 = s2 + # sol2 = s1 | s2. + s1, s2 = FiniteSet(-y/sqrt(y**2 + 1)), FiniteSet(y/sqrt(y**2 + 1)) + cset = ConditionSet(x, Eq(eq1, 0), s1) + sol1 = (s2 - {-1, 1}) | (cset - {-1, 1}) + sol2 = (s1 | s2) - {-1, 1} + + assert solveset(eq1, x, S.Reals) == sol1 + assert solveset(eq2, x, S.Reals) == sol2 + + +def test_issue_10477(): + assert solveset((x**2 + 4*x - 3)/x < 2, x, S.Reals) == \ + Union(Interval.open(-oo, -3), Interval.open(0, 1)) + + +def test_issue_10671(): + assert solveset(sin(y), y, Interval(0, pi)) == FiniteSet(0, pi) + i = Interval(1, 10) + assert solveset((1/x).diff(x) < 0, x, i) == i + + +def test_issue_11064(): + eq = x + sqrt(x**2 - 5) + assert solveset(eq > 0, x, S.Reals) == \ + Interval(sqrt(5), oo) + assert solveset(eq < 0, x, S.Reals) == \ + Interval(-oo, -sqrt(5)) + assert solveset(eq > sqrt(5), x, S.Reals) == \ + Interval.Lopen(sqrt(5), oo) + + +def test_issue_12478(): + eq = sqrt(x - 2) + 2 + soln = solveset_real(eq, x) + assert soln is S.EmptySet + assert solveset(eq < 0, x, S.Reals) is S.EmptySet + assert solveset(eq > 0, x, S.Reals) == Interval(2, oo) + + +def test_issue_12429(): + eq = solveset(log(x)/x <= 0, x, S.Reals) + sol = Interval.Lopen(0, 1) + assert eq == sol + + +def test_issue_19506(): + eq = arg(x + I) + C = Dummy('C') + assert solveset(eq).dummy_eq(Intersection(ConditionSet(C, Eq(im(C) + 1, 0), S.Complexes), + ConditionSet(C, re(C) > 0, S.Complexes))) + + +def test_solveset_arg(): + assert solveset(arg(x), x, S.Reals) == Interval.open(0, oo) + assert solveset(arg(4*x -3), x, S.Reals) == Interval.open(Rational(3, 4), oo) + + +def test__is_finite_with_finite_vars(): + f = _is_finite_with_finite_vars + # issue 12482 + assert all(f(1/x) is None for x in ( + Dummy(), Dummy(real=True), Dummy(complex=True))) + assert f(1/Dummy(real=False)) is True # b/c it's finite but not 0 + + +def test_issue_13550(): + assert solveset(x**2 - 2*x - 15, symbol = x, domain = Interval(-oo, 0)) == FiniteSet(-3) + + +def test_issue_13849(): + assert nonlinsolve((t*(sqrt(5) + sqrt(2)) - sqrt(2), t), t) is S.EmptySet + + +def test_issue_14223(): + assert solveset((Abs(x + Min(x, 2)) - 2).rewrite(Piecewise), x, + S.Reals) == FiniteSet(-1, 1) + assert solveset((Abs(x + Min(x, 2)) - 2).rewrite(Piecewise), x, + Interval(0, 2)) == FiniteSet(1) + assert solveset(x, x, FiniteSet(1, 2)) is S.EmptySet + + +def test_issue_10158(): + dom = S.Reals + assert solveset(x*Max(x, 15) - 10, x, dom) == FiniteSet(Rational(2, 3)) + assert solveset(x*Min(x, 15) - 10, x, dom) == FiniteSet(-sqrt(10), sqrt(10)) + assert solveset(Max(Abs(x - 3) - 1, x + 2) - 3, x, dom) == FiniteSet(-1, 1) + assert solveset(Abs(x - 1) - Abs(y), x, dom) == FiniteSet(-Abs(y) + 1, Abs(y) + 1) + assert solveset(Abs(x + 4*Abs(x + 1)), x, dom) == FiniteSet(Rational(-4, 3), Rational(-4, 5)) + assert solveset(2*Abs(x + Abs(x + Max(3, x))) - 2, x, S.Reals) == FiniteSet(-1, -2) + dom = S.Complexes + raises(ValueError, lambda: solveset(x*Max(x, 15) - 10, x, dom)) + raises(ValueError, lambda: solveset(x*Min(x, 15) - 10, x, dom)) + raises(ValueError, lambda: solveset(Max(Abs(x - 3) - 1, x + 2) - 3, x, dom)) + raises(ValueError, lambda: solveset(Abs(x - 1) - Abs(y), x, dom)) + raises(ValueError, lambda: solveset(Abs(x + 4*Abs(x + 1)), x, dom)) + + +def test_issue_14300(): + f = 1 - exp(-18000000*x) - y + a1 = FiniteSet(-log(-y + 1)/18000000) + + assert solveset(f, x, S.Reals) == \ + Intersection(S.Reals, a1) + assert dumeq(solveset(f, x), + ImageSet(Lambda(n, -I*(2*n*pi + arg(-y + 1))/18000000 - + log(Abs(y - 1))/18000000), S.Integers)) + + +def test_issue_14454(): + number = CRootOf(x**4 + x - 1, 2) + raises(ValueError, lambda: invert_real(number, 0, x)) + assert invert_real(x**2, number, x) # no error + + +def test_issue_17882(): + assert solveset(-8*x**2/(9*(x**2 - 1)**(S(4)/3)) + 4/(3*(x**2 - 1)**(S(1)/3)), x, S.Complexes) == \ + FiniteSet(sqrt(3), -sqrt(3)) + + +def test_term_factors(): + assert list(_term_factors(3**x - 2)) == [-2, 3**x] + expr = 4**(x + 1) + 4**(x + 2) + 4**(x - 1) - 3**(x + 2) - 3**(x + 3) + assert set(_term_factors(expr)) == { + 3**(x + 2), 4**(x + 2), 3**(x + 3), 4**(x - 1), -1, 4**(x + 1)} + + +#################### tests for transolve and its helpers ############### + +def test_transolve(): + + assert _transolve(3**x, x, S.Reals) == S.EmptySet + assert _transolve(3**x - 9**(x + 5), x, S.Reals) == FiniteSet(-10) + + +def test_issue_21276(): + eq = (2*x*(y - z) - y*erf(y - z) - y + z*erf(y - z) + z)**2 + assert solveset(eq.expand(), y) == FiniteSet(z, z + erfinv(2*x - 1)) + + +# exponential tests +def test_exponential_real(): + from sympy.abc import y + + e1 = 3**(2*x) - 2**(x + 3) + e2 = 4**(5 - 9*x) - 8**(2 - x) + e3 = 2**x + 4**x + e4 = exp(log(5)*x) - 2**x + e5 = exp(x/y)*exp(-z/y) - 2 + e6 = 5**(x/2) - 2**(x/3) + e7 = 4**(x + 1) + 4**(x + 2) + 4**(x - 1) - 3**(x + 2) - 3**(x + 3) + e8 = -9*exp(-2*x + 5) + 4*exp(3*x + 1) + e9 = 2**x + 4**x + 8**x - 84 + e10 = 29*2**(x + 1)*615**(x) - 123*2726**(x) + + assert solveset(e1, x, S.Reals) == FiniteSet( + -3*log(2)/(-2*log(3) + log(2))) + assert solveset(e2, x, S.Reals) == FiniteSet(Rational(4, 15)) + assert solveset(e3, x, S.Reals) == S.EmptySet + assert solveset(e4, x, S.Reals) == FiniteSet(0) + assert solveset(e5, x, S.Reals) == Intersection( + S.Reals, FiniteSet(y*log(2*exp(z/y)))) + assert solveset(e6, x, S.Reals) == FiniteSet(0) + assert solveset(e7, x, S.Reals) == FiniteSet(2) + assert solveset(e8, x, S.Reals) == FiniteSet(-2*log(2)/5 + 2*log(3)/5 + Rational(4, 5)) + assert solveset(e9, x, S.Reals) == FiniteSet(2) + assert solveset(e10,x, S.Reals) == FiniteSet((-log(29) - log(2) + log(123))/(-log(2726) + log(2) + log(615))) + + assert solveset_real(-9*exp(-2*x + 5) + 2**(x + 1), x) == FiniteSet( + -((-5 - 2*log(3) + log(2))/(log(2) + 2))) + assert solveset_real(4**(x/2) - 2**(x/3), x) == FiniteSet(0) + b = sqrt(6)*sqrt(log(2))/sqrt(log(5)) + assert solveset_real(5**(x/2) - 2**(3/x), x) == FiniteSet(-b, b) + + # coverage test + C1, C2 = symbols('C1 C2') + f = Function('f') + assert solveset_real(C1 + C2/x**2 - exp(-f(x)), f(x)) == Intersection( + S.Reals, FiniteSet(-log(C1 + C2/x**2))) + y = symbols('y', positive=True) + assert solveset_real(x**2 - y**2/exp(x), y) == Intersection( + S.Reals, FiniteSet(-sqrt(x**2*exp(x)), sqrt(x**2*exp(x)))) + p = Symbol('p', positive=True) + assert solveset_real((1/p + 1)**(p + 1), p).dummy_eq( + ConditionSet(x, Eq((1 + 1/x)**(x + 1), 0), S.Reals)) + assert solveset(2**x - 4**x + 12, x, S.Reals) == {2} + assert solveset(2**x - 2**(2*x) + 12, x, S.Reals) == {2} + + +@XFAIL +def test_exponential_complex(): + n = Dummy('n') + + assert dumeq(solveset_complex(2**x + 4**x, x),imageset( + Lambda(n, I*(2*n*pi + pi)/log(2)), S.Integers)) + assert solveset_complex(x**z*y**z - 2, z) == FiniteSet( + log(2)/(log(x) + log(y))) + assert dumeq(solveset_complex(4**(x/2) - 2**(x/3), x), imageset( + Lambda(n, 3*n*I*pi/log(2)), S.Integers)) + assert dumeq(solveset(2**x + 32, x), imageset( + Lambda(n, (I*(2*n*pi + pi) + 5*log(2))/log(2)), S.Integers)) + + eq = (2**exp(y**2/x) + 2)/(x**2 + 15) + a = sqrt(x)*sqrt(-log(log(2)) + log(log(2) + 2*n*I*pi)) + assert solveset_complex(eq, y) == FiniteSet(-a, a) + + union1 = imageset(Lambda(n, I*(2*n*pi - pi*Rational(2, 3))/log(2)), S.Integers) + union2 = imageset(Lambda(n, I*(2*n*pi + pi*Rational(2, 3))/log(2)), S.Integers) + assert dumeq(solveset(2**x + 4**x + 8**x, x), Union(union1, union2)) + + eq = 4**(x + 1) + 4**(x + 2) + 4**(x - 1) - 3**(x + 2) - 3**(x + 3) + res = solveset(eq, x) + num = 2*n*I*pi - 4*log(2) + 2*log(3) + den = -2*log(2) + log(3) + ans = imageset(Lambda(n, num/den), S.Integers) + assert dumeq(res, ans) + + +def test_expo_conditionset(): + + f1 = (exp(x) + 1)**x - 2 + f2 = (x + 2)**y*x - 3 + f3 = 2**x - exp(x) - 3 + f4 = log(x) - exp(x) + f5 = 2**x + 3**x - 5**x + + assert solveset(f1, x, S.Reals).dummy_eq(ConditionSet( + x, Eq((exp(x) + 1)**x - 2, 0), S.Reals)) + assert solveset(f2, x, S.Reals).dummy_eq(ConditionSet( + x, Eq(x*(x + 2)**y - 3, 0), S.Reals)) + assert solveset(f3, x, S.Reals).dummy_eq(ConditionSet( + x, Eq(2**x - exp(x) - 3, 0), S.Reals)) + assert solveset(f4, x, S.Reals).dummy_eq(ConditionSet( + x, Eq(-exp(x) + log(x), 0), S.Reals)) + assert solveset(f5, x, S.Reals).dummy_eq(ConditionSet( + x, Eq(2**x + 3**x - 5**x, 0), S.Reals)) + + +def test_exponential_symbols(): + x, y, z = symbols('x y z', positive=True) + xr, zr = symbols('xr, zr', real=True) + + assert solveset(z**x - y, x, S.Reals) == Intersection( + S.Reals, FiniteSet(log(y)/log(z))) + + f1 = 2*x**w - 4*y**w + f2 = (x/y)**w - 2 + sol1 = Intersection({log(2)/(log(x) - log(y))}, S.Reals) + sol2 = Intersection({log(2)/log(x/y)}, S.Reals) + assert solveset(f1, w, S.Reals) == sol1, solveset(f1, w, S.Reals) + assert solveset(f2, w, S.Reals) == sol2, solveset(f2, w, S.Reals) + + assert solveset(x**x, x, Interval.Lopen(0,oo)).dummy_eq( + ConditionSet(w, Eq(w**w, 0), Interval.open(0, oo))) + assert solveset(x**y - 1, y, S.Reals) == FiniteSet(0) + assert solveset(exp(x/y)*exp(-z/y) - 2, y, S.Reals) == \ + Complement(ConditionSet(y, Eq(im(x)/y, 0) & Eq(im(z)/y, 0), \ + Complement(Intersection(FiniteSet((x - z)/log(2)), S.Reals), FiniteSet(0))), FiniteSet(0)) + assert solveset(exp(xr/y)*exp(-zr/y) - 2, y, S.Reals) == \ + Complement(FiniteSet((xr - zr)/log(2)), FiniteSet(0)) + + assert solveset(a**x - b**x, x).dummy_eq(ConditionSet( + w, Ne(a, 0) & Ne(b, 0), FiniteSet(0))) + + +def test_ignore_assumptions(): + # make sure assumptions are ignored + xpos = symbols('x', positive=True) + x = symbols('x') + assert solveset_complex(xpos**2 - 4, xpos + ) == solveset_complex(x**2 - 4, x) + + +@XFAIL +def test_issue_10864(): + assert solveset(x**(y*z) - x, x, S.Reals) == FiniteSet(1) + + +@XFAIL +def test_solve_only_exp_2(): + assert solveset_real(sqrt(exp(x)) + sqrt(exp(-x)) - 4, x) == \ + FiniteSet(2*log(-sqrt(3) + 2), 2*log(sqrt(3) + 2)) + + +def test_is_exponential(): + assert _is_exponential(y, x) is False + assert _is_exponential(3**x - 2, x) is True + assert _is_exponential(5**x - 7**(2 - x), x) is True + assert _is_exponential(sin(2**x) - 4*x, x) is False + assert _is_exponential(x**y - z, y) is True + assert _is_exponential(x**y - z, x) is False + assert _is_exponential(2**x + 4**x - 1, x) is True + assert _is_exponential(x**(y*z) - x, x) is False + assert _is_exponential(x**(2*x) - 3**x, x) is False + assert _is_exponential(x**y - y*z, y) is False + assert _is_exponential(x**y - x*z, y) is True + + +def test_solve_exponential(): + assert _solve_exponential(3**(2*x) - 2**(x + 3), 0, x, S.Reals) == \ + FiniteSet(-3*log(2)/(-2*log(3) + log(2))) + assert _solve_exponential(2**y + 4**y, 1, y, S.Reals) == \ + FiniteSet(log(Rational(-1, 2) + sqrt(5)/2)/log(2)) + assert _solve_exponential(2**y + 4**y, 0, y, S.Reals) == \ + S.EmptySet + assert _solve_exponential(2**x + 3**x - 5**x, 0, x, S.Reals) == \ + ConditionSet(x, Eq(2**x + 3**x - 5**x, 0), S.Reals) + +# end of exponential tests + + +# logarithmic tests +def test_logarithmic(): + assert solveset_real(log(x - 3) + log(x + 3), x) == FiniteSet( + -sqrt(10), sqrt(10)) + assert solveset_real(log(x + 1) - log(2*x - 1), x) == FiniteSet(2) + assert solveset_real(log(x + 3) + log(1 + 3/x) - 3, x) == FiniteSet( + -3 + sqrt(-12 + exp(3))*exp(Rational(3, 2))/2 + exp(3)/2, + -sqrt(-12 + exp(3))*exp(Rational(3, 2))/2 - 3 + exp(3)/2) + + eq = z - log(x) + log(y/(x*(-1 + y**2/x**2))) + assert solveset_real(eq, x) == \ + Intersection(S.Reals, FiniteSet(-sqrt(y**2 - y*exp(z)), + sqrt(y**2 - y*exp(z)))) - \ + Intersection(S.Reals, FiniteSet(-sqrt(y**2), sqrt(y**2))) + assert solveset_real( + log(3*x) - log(-x + 1) - log(4*x + 1), x) == FiniteSet(Rational(-1, 2), S.Half) + assert solveset(log(x**y) - y*log(x), x, S.Reals) == S.Reals + +@XFAIL +def test_uselogcombine_2(): + eq = log(exp(2*x) + 1) + log(-tanh(x) + 1) - log(2) + assert solveset_real(eq, x) is S.EmptySet + eq = log(8*x) - log(sqrt(x) + 1) - 2 + assert solveset_real(eq, x) is S.EmptySet + + +def test_is_logarithmic(): + assert _is_logarithmic(y, x) is False + assert _is_logarithmic(log(x), x) is True + assert _is_logarithmic(log(x) - 3, x) is True + assert _is_logarithmic(log(x)*log(y), x) is True + assert _is_logarithmic(log(x)**2, x) is False + assert _is_logarithmic(log(x - 3) + log(x + 3), x) is True + assert _is_logarithmic(log(x**y) - y*log(x), x) is True + assert _is_logarithmic(sin(log(x)), x) is False + assert _is_logarithmic(x + y, x) is False + assert _is_logarithmic(log(3*x) - log(1 - x) + 4, x) is True + assert _is_logarithmic(log(x) + log(y) + x, x) is False + assert _is_logarithmic(log(log(x - 3)) + log(x - 3), x) is True + assert _is_logarithmic(log(log(3) + x) + log(x), x) is True + assert _is_logarithmic(log(x)*(y + 3) + log(x), y) is False + + +def test_solve_logarithm(): + y = Symbol('y') + assert _solve_logarithm(log(x**y) - y*log(x), 0, x, S.Reals) == S.Reals + y = Symbol('y', positive=True) + assert _solve_logarithm(log(x)*log(y), 0, x, S.Reals) == FiniteSet(1) + +# end of logarithmic tests + + +# lambert tests +def test_is_lambert(): + a, b, c = symbols('a,b,c') + assert _is_lambert(x**2, x) is False + assert _is_lambert(a**x**2+b*x+c, x) is True + assert _is_lambert(E**2, x) is False + assert _is_lambert(x*E**2, x) is False + assert _is_lambert(3*log(x) - x*log(3), x) is True + assert _is_lambert(log(log(x - 3)) + log(x-3), x) is True + assert _is_lambert(5*x - 1 + 3*exp(2 - 7*x), x) is True + assert _is_lambert((a/x + exp(x/2)).diff(x, 2), x) is True + assert _is_lambert((x**2 - 2*x + 1).subs(x, (log(x) + 3*x)**2 - 1), x) is True + assert _is_lambert(x*sinh(x) - 1, x) is True + assert _is_lambert(x*cos(x) - 5, x) is True + assert _is_lambert(tanh(x) - 5*x, x) is True + assert _is_lambert(cosh(x) - sinh(x), x) is False + +# end of lambert tests + + +def test_linear_coeffs(): + from sympy.solvers.solveset import linear_coeffs + assert linear_coeffs(0, x) == [0, 0] + assert all(i is S.Zero for i in linear_coeffs(0, x)) + assert linear_coeffs(x + 2*y + 3, x, y) == [1, 2, 3] + assert linear_coeffs(x + 2*y + 3, y, x) == [2, 1, 3] + assert linear_coeffs(x + 2*x**2 + 3, x, x**2) == [1, 2, 3] + raises(ValueError, lambda: + linear_coeffs(x + 2*x**2 + x**3, x, x**2)) + raises(ValueError, lambda: + linear_coeffs(1/x*(x - 1) + 1/x, x)) + raises(ValueError, lambda: + linear_coeffs(x, x, x)) + assert linear_coeffs(a*(x + y), x, y) == [a, a, 0] + assert linear_coeffs(1.0, x, y) == [0, 0, 1.0] + # don't include coefficients of 0 + assert linear_coeffs(Eq(x, x + y), x, y, dict=True) == {y: -1} + assert linear_coeffs(0, x, y, dict=True) == {} + + +def test_is_modular(): + assert _is_modular(y, x) is False + assert _is_modular(Mod(x, 3) - 1, x) is True + assert _is_modular(Mod(x**3 - 3*x**2 - x + 1, 3) - 1, x) is True + assert _is_modular(Mod(exp(x + y), 3) - 2, x) is True + assert _is_modular(Mod(exp(x + y), 3) - log(x), x) is True + assert _is_modular(Mod(x, 3) - 1, y) is False + assert _is_modular(Mod(x, 3)**2 - 5, x) is False + assert _is_modular(Mod(x, 3)**2 - y, x) is False + assert _is_modular(exp(Mod(x, 3)) - 1, x) is False + assert _is_modular(Mod(3, y) - 1, y) is False + + +def test_invert_modular(): + n = Dummy('n', integer=True) + from sympy.solvers.solveset import _invert_modular as invert_modular + + # no solutions + assert invert_modular(Mod(x, 12), S(1)/2, n, x) == (x, S.EmptySet) + # non invertible cases + assert invert_modular(Mod(sin(x), 7), S(5), n, x) == (Mod(sin(x), 7), 5) + assert invert_modular(Mod(exp(x), 7), S(5), n, x) == (Mod(exp(x), 7), 5) + assert invert_modular(Mod(log(x), 7), S(5), n, x) == (Mod(log(x), 7), 5) + # a is symbol + assert dumeq(invert_modular(Mod(x, 7), S(5), n, x), + (x, ImageSet(Lambda(n, 7*n + 5), S.Integers))) + # a.is_Add + assert dumeq(invert_modular(Mod(x + 8, 7), S(5), n, x), + (x, ImageSet(Lambda(n, 7*n + 4), S.Integers))) + assert invert_modular(Mod(x**2 + x, 7), S(5), n, x) == \ + (Mod(x**2 + x, 7), 5) + # a.is_Mul + assert dumeq(invert_modular(Mod(3*x, 7), S(5), n, x), + (x, ImageSet(Lambda(n, 7*n + 4), S.Integers))) + assert invert_modular(Mod((x + 1)*(x + 2), 7), S(5), n, x) == \ + (Mod((x + 1)*(x + 2), 7), 5) + # a.is_Pow + assert invert_modular(Mod(x**4, 7), S(5), n, x) == \ + (x, S.EmptySet) + assert dumeq(invert_modular(Mod(3**x, 4), S(3), n, x), + (x, ImageSet(Lambda(n, 2*n + 1), S.Naturals0))) + assert dumeq(invert_modular(Mod(2**(x**2 + x + 1), 7), S(2), n, x), + (x**2 + x + 1, ImageSet(Lambda(n, 3*n + 1), S.Naturals0))) + assert invert_modular(Mod(sin(x)**4, 7), S(5), n, x) == (x, S.EmptySet) + + +def test_solve_modular(): + n = Dummy('n', integer=True) + # if rhs has symbol (need to be implemented in future). + assert solveset(Mod(x, 4) - x, x, S.Integers + ).dummy_eq( + ConditionSet(x, Eq(-x + Mod(x, 4), 0), + S.Integers)) + # when _invert_modular fails to invert + assert solveset(3 - Mod(sin(x), 7), x, S.Integers + ).dummy_eq( + ConditionSet(x, Eq(Mod(sin(x), 7) - 3, 0), S.Integers)) + assert solveset(3 - Mod(log(x), 7), x, S.Integers + ).dummy_eq( + ConditionSet(x, Eq(Mod(log(x), 7) - 3, 0), S.Integers)) + assert solveset(3 - Mod(exp(x), 7), x, S.Integers + ).dummy_eq(ConditionSet(x, Eq(Mod(exp(x), 7) - 3, 0), + S.Integers)) + # EmptySet solution definitely + assert solveset(7 - Mod(x, 5), x, S.Integers) is S.EmptySet + assert solveset(5 - Mod(x, 5), x, S.Integers) is S.EmptySet + # Negative m + assert dumeq(solveset(2 + Mod(x, -3), x, S.Integers), + ImageSet(Lambda(n, -3*n - 2), S.Integers)) + assert solveset(4 + Mod(x, -3), x, S.Integers) is S.EmptySet + # linear expression in Mod + assert dumeq(solveset(3 - Mod(x, 5), x, S.Integers), + ImageSet(Lambda(n, 5*n + 3), S.Integers)) + assert dumeq(solveset(3 - Mod(5*x - 8, 7), x, S.Integers), + ImageSet(Lambda(n, 7*n + 5), S.Integers)) + assert dumeq(solveset(3 - Mod(5*x, 7), x, S.Integers), + ImageSet(Lambda(n, 7*n + 2), S.Integers)) + # higher degree expression in Mod + assert dumeq(solveset(Mod(x**2, 160) - 9, x, S.Integers), + Union(ImageSet(Lambda(n, 160*n + 3), S.Integers), + ImageSet(Lambda(n, 160*n + 13), S.Integers), + ImageSet(Lambda(n, 160*n + 67), S.Integers), + ImageSet(Lambda(n, 160*n + 77), S.Integers), + ImageSet(Lambda(n, 160*n + 83), S.Integers), + ImageSet(Lambda(n, 160*n + 93), S.Integers), + ImageSet(Lambda(n, 160*n + 147), S.Integers), + ImageSet(Lambda(n, 160*n + 157), S.Integers))) + assert solveset(3 - Mod(x**4, 7), x, S.Integers) is S.EmptySet + assert dumeq(solveset(Mod(x**4, 17) - 13, x, S.Integers), + Union(ImageSet(Lambda(n, 17*n + 3), S.Integers), + ImageSet(Lambda(n, 17*n + 5), S.Integers), + ImageSet(Lambda(n, 17*n + 12), S.Integers), + ImageSet(Lambda(n, 17*n + 14), S.Integers))) + # a.is_Pow tests + assert dumeq(solveset(Mod(7**x, 41) - 15, x, S.Integers), + ImageSet(Lambda(n, 40*n + 3), S.Naturals0)) + assert dumeq(solveset(Mod(12**x, 21) - 18, x, S.Integers), + ImageSet(Lambda(n, 6*n + 2), S.Naturals0)) + assert dumeq(solveset(Mod(3**x, 4) - 3, x, S.Integers), + ImageSet(Lambda(n, 2*n + 1), S.Naturals0)) + assert dumeq(solveset(Mod(2**x, 7) - 2 , x, S.Integers), + ImageSet(Lambda(n, 3*n + 1), S.Naturals0)) + assert dumeq(solveset(Mod(3**(3**x), 4) - 3, x, S.Integers), + Intersection(ImageSet(Lambda(n, Intersection({log(2*n + 1)/log(3)}, + S.Integers)), S.Naturals0), S.Integers)) + # Implemented for m without primitive root + assert solveset(Mod(x**3, 7) - 2, x, S.Integers) is S.EmptySet + assert dumeq(solveset(Mod(x**3, 8) - 1, x, S.Integers), + ImageSet(Lambda(n, 8*n + 1), S.Integers)) + assert dumeq(solveset(Mod(x**4, 9) - 4, x, S.Integers), + Union(ImageSet(Lambda(n, 9*n + 4), S.Integers), + ImageSet(Lambda(n, 9*n + 5), S.Integers))) + # domain intersection + assert dumeq(solveset(3 - Mod(5*x - 8, 7), x, S.Naturals0), + Intersection(ImageSet(Lambda(n, 7*n + 5), S.Integers), S.Naturals0)) + # Complex args + assert solveset(Mod(x, 3) - I, x, S.Integers) == \ + S.EmptySet + assert solveset(Mod(I*x, 3) - 2, x, S.Integers + ).dummy_eq( + ConditionSet(x, Eq(Mod(I*x, 3) - 2, 0), S.Integers)) + assert solveset(Mod(I + x, 3) - 2, x, S.Integers + ).dummy_eq( + ConditionSet(x, Eq(Mod(x + I, 3) - 2, 0), S.Integers)) + + # issue 17373 (https://github.com/sympy/sympy/issues/17373) + assert dumeq(solveset(Mod(x**4, 14) - 11, x, S.Integers), + Union(ImageSet(Lambda(n, 14*n + 3), S.Integers), + ImageSet(Lambda(n, 14*n + 11), S.Integers))) + assert dumeq(solveset(Mod(x**31, 74) - 43, x, S.Integers), + ImageSet(Lambda(n, 74*n + 31), S.Integers)) + + # issue 13178 + n = symbols('n', integer=True) + a = 742938285 + b = 1898888478 + m = 2**31 - 1 + c = 20170816 + assert dumeq(solveset(c - Mod(a**n*b, m), n, S.Integers), + ImageSet(Lambda(n, 2147483646*n + 100), S.Naturals0)) + assert dumeq(solveset(c - Mod(a**n*b, m), n, S.Naturals0), + Intersection(ImageSet(Lambda(n, 2147483646*n + 100), S.Naturals0), + S.Naturals0)) + assert dumeq(solveset(c - Mod(a**(2*n)*b, m), n, S.Integers), + Intersection(ImageSet(Lambda(n, 1073741823*n + 50), S.Naturals0), + S.Integers)) + assert solveset(c - Mod(a**(2*n + 7)*b, m), n, S.Integers) is S.EmptySet + assert dumeq(solveset(c - Mod(a**(n - 4)*b, m), n, S.Integers), + Intersection(ImageSet(Lambda(n, 2147483646*n + 104), S.Naturals0), + S.Integers)) + +# end of modular tests + +def test_issue_17276(): + assert nonlinsolve([Eq(x, 5**(S(1)/5)), Eq(x*y, 25*sqrt(5))], x, y) == \ + FiniteSet((5**(S(1)/5), 25*5**(S(3)/10))) + + +def test_issue_10426(): + x = Dummy('x') + a = Symbol('a') + n = Dummy('n') + assert (solveset(sin(x + a) - sin(x), a)).dummy_eq(Dummy('x')) == (Union( + ImageSet(Lambda(n, 2*n*pi), S.Integers), + Intersection(S.Complexes, ImageSet(Lambda(n, -I*(I*(2*n*pi + arg(-exp(-2*I*x))) + 2*im(x))), + S.Integers)))).dummy_eq(Dummy('x,n')) + + +def test_solveset_conjugate(): + """Test solveset for simple conjugate functions""" + assert solveset(conjugate(x) -3 + I) == FiniteSet(3 + I) + + +def test_issue_18208(): + variables = symbols('x0:16') + symbols('y0:12') + x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15,\ + y0, y1, y2, y3, y4, y5, y6, y7, y8, y9, y10, y11 = variables + + eqs = [x0 + x1 + x2 + x3 - 51, + x0 + x1 + x4 + x5 - 46, + x2 + x3 + x6 + x7 - 39, + x0 + x3 + x4 + x7 - 50, + x1 + x2 + x5 + x6 - 35, + x4 + x5 + x6 + x7 - 34, + x4 + x5 + x8 + x9 - 46, + x10 + x11 + x6 + x7 - 23, + x11 + x4 + x7 + x8 - 25, + x10 + x5 + x6 + x9 - 44, + x10 + x11 + x8 + x9 - 35, + x12 + x13 + x8 + x9 - 35, + x10 + x11 + x14 + x15 - 29, + x11 + x12 + x15 + x8 - 35, + x10 + x13 + x14 + x9 - 29, + x12 + x13 + x14 + x15 - 29, + y0 + y1 + y2 + y3 - 55, + y0 + y1 + y4 + y5 - 53, + y2 + y3 + y6 + y7 - 56, + y0 + y3 + y4 + y7 - 57, + y1 + y2 + y5 + y6 - 52, + y4 + y5 + y6 + y7 - 54, + y4 + y5 + y8 + y9 - 48, + y10 + y11 + y6 + y7 - 60, + y11 + y4 + y7 + y8 - 51, + y10 + y5 + y6 + y9 - 57, + y10 + y11 + y8 + y9 - 54, + x10 - 2, + x11 - 5, + x12 - 1, + x13 - 6, + x14 - 1, + x15 - 21, + y0 - 12, + y1 - 20] + + expected = [38 - x3, x3 - 10, 23 - x3, x3, 12 - x7, x7 + 6, 16 - x7, x7, + 8, 20, 2, 5, 1, 6, 1, 21, 12, 20, -y11 + y9 + 2, y11 - y9 + 21, + -y11 - y7 + y9 + 24, y11 + y7 - y9 - 3, 33 - y7, y7, 27 - y9, y9, + 27 - y11, y11] + + A, b = linear_eq_to_matrix(eqs, variables) + + # solve + solve_expected = {v:eq for v, eq in zip(variables, expected) if v != eq} + + assert solve(eqs, variables) == solve_expected + + # linsolve + linsolve_expected = FiniteSet(Tuple(*expected)) + + assert linsolve(eqs, variables) == linsolve_expected + assert linsolve((A, b), variables) == linsolve_expected + + # gauss_jordan_solve + gj_solve, new_vars = A.gauss_jordan_solve(b) + gj_solve = list(gj_solve) + + gj_expected = linsolve_expected.subs(zip([x3, x7, y7, y9, y11], new_vars)) + + assert FiniteSet(Tuple(*gj_solve)) == gj_expected + + # nonlinsolve + # The solution set of nonlinsolve is currently equivalent to linsolve and is + # also correct. However, we would prefer to use the same symbols as parameters + # for the solution to the underdetermined system in all cases if possible. + # We want a solution that is not just equivalent but also given in the same form. + # This test may be changed should nonlinsolve be modified in this way. + + nonlinsolve_expected = FiniteSet((38 - x3, x3 - 10, 23 - x3, x3, 12 - x7, x7 + 6, + 16 - x7, x7, 8, 20, 2, 5, 1, 6, 1, 21, 12, 20, + -y5 + y7 - 1, y5 - y7 + 24, 21 - y5, y5, 33 - y7, + y7, 27 - y9, y9, -y5 + y7 - y9 + 24, y5 - y7 + y9 + 3)) + + assert nonlinsolve(eqs, variables) == nonlinsolve_expected + + +def test_substitution_with_infeasible_solution(): + a00, a01, a10, a11, l0, l1, l2, l3, m0, m1, m2, m3, m4, m5, m6, m7, c00, c01, c10, c11, p00, p01, p10, p11 = symbols( + 'a00, a01, a10, a11, l0, l1, l2, l3, m0, m1, m2, m3, m4, m5, m6, m7, c00, c01, c10, c11, p00, p01, p10, p11' + ) + solvefor = [p00, p01, p10, p11, c00, c01, c10, c11, m0, m1, m3, l0, l1, l2, l3] + system = [ + -l0 * c00 - l1 * c01 + m0 + c00 + c01, + -l0 * c10 - l1 * c11 + m1, + -l2 * c00 - l3 * c01 + c00 + c01, + -l2 * c10 - l3 * c11 + m3, + -l0 * p00 - l2 * p10 + p00 + p10, + -l1 * p00 - l3 * p10 + p00 + p10, + -l0 * p01 - l2 * p11, + -l1 * p01 - l3 * p11, + -a00 + c00 * p00 + c10 * p01, + -a01 + c01 * p00 + c11 * p01, + -a10 + c00 * p10 + c10 * p11, + -a11 + c01 * p10 + c11 * p11, + -m0 * p00, + -m1 * p01, + -m2 * p10, + -m3 * p11, + -m4 * c00, + -m5 * c01, + -m6 * c10, + -m7 * c11, + m2, + m4, + m5, + m6, + m7 + ] + sol = FiniteSet( + (0, Complement(FiniteSet(p01), FiniteSet(0)), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, l2, l3), + (p00, Complement(FiniteSet(p01), FiniteSet(0)), 0, p11, 0, 0, 0, 0, 0, 0, 0, 1, 1, -p01/p11, -p01/p11), + (0, Complement(FiniteSet(p01), FiniteSet(0)), 0, p11, 0, 0, 0, 0, 0, 0, 0, 1, -l3*p11/p01, -p01/p11, l3), + (0, Complement(FiniteSet(p01), FiniteSet(0)), 0, p11, 0, 0, 0, 0, 0, 0, 0, -l2*p11/p01, -l3*p11/p01, l2, l3), + ) + assert sol != nonlinsolve(system, solvefor) + + +def test_issue_20097(): + assert solveset(1/sqrt(x)) is S.EmptySet + + +def test_issue_15350(): + assert solveset(diff(sqrt(1/x+x))) == FiniteSet(-1, 1) + + +def test_issue_18359(): + c1 = Piecewise((0, x < 0), (Min(1, x)/2 - Min(2, x)/2 + Min(3, x)/2, True)) + c2 = Piecewise((Piecewise((0, x < 0), (Min(1, x)/2 - Min(2, x)/2 + Min(3, x)/2, True)), x >= 0), (0, True)) + correct_result = Interval(1, 2) + result1 = solveset(c1 - Rational(1, 2), x, Interval(0, 3)) + result2 = solveset(c2 - Rational(1, 2), x, Interval(0, 3)) + assert result1 == correct_result + assert result2 == correct_result + + +def test_issue_17604(): + lhs = -2**(3*x/11)*exp(x/11) + pi**(x/11) + assert _is_exponential(lhs, x) + assert _solve_exponential(lhs, 0, x, S.Complexes) == FiniteSet(0) + + +def test_issue_17580(): + assert solveset(1/(1 - x**3)**2, x, S.Reals) is S.EmptySet + + +def test_issue_17566_actual(): + sys = [2**x + 2**y - 3, 4**x + 9**y - 5] + # Not clear this is the correct result, but at least no recursion error + assert nonlinsolve(sys, x, y) == FiniteSet((log(3 - 2**y)/log(2), y)) + + +def test_issue_17565(): + eq = Ge(2*(x - 2)**2/(3*(x + 1)**(Integer(1)/3)) + 2*(x - 2)*(x + 1)**(Integer(2)/3), 0) + res = Union(Interval.Lopen(-1, -Rational(1, 4)), Interval(2, oo)) + assert solveset(eq, x, S.Reals) == res + + +def test_issue_15024(): + function = (x + 5)/sqrt(-x**2 - 10*x) + assert solveset(function, x, S.Reals) == FiniteSet(Integer(-5)) + + +def test_issue_16877(): + assert dumeq(nonlinsolve([x - 1, sin(y)], x, y), + FiniteSet((1, ImageSet(Lambda(n, 2*n*pi), S.Integers)), + (1, ImageSet(Lambda(n, 2*n*pi + pi), S.Integers)))) + # Even better if (1, ImageSet(Lambda(n, n*pi), S.Integers)) is obtained + + +def test_issue_16876(): + assert dumeq(nonlinsolve([sin(x), 2*x - 4*y], x, y), + FiniteSet((ImageSet(Lambda(n, 2*n*pi), S.Integers), + ImageSet(Lambda(n, n*pi), S.Integers)), + (ImageSet(Lambda(n, 2*n*pi + pi), S.Integers), + ImageSet(Lambda(n, n*pi + pi/2), S.Integers)))) + # Even better if (ImageSet(Lambda(n, n*pi), S.Integers), + # ImageSet(Lambda(n, n*pi/2), S.Integers)) is obtained + +def test_issue_21236(): + x, z = symbols("x z") + y = symbols('y', rational=True) + assert solveset(x**y - z, x, S.Reals) == ConditionSet(x, Eq(x**y - z, 0), S.Reals) + e1, e2 = symbols('e1 e2', even=True) + y = e1/e2 # don't know if num or den will be odd and the other even + assert solveset(x**y - z, x, S.Reals) == ConditionSet(x, Eq(x**y - z, 0), S.Reals) + + +def test_issue_21908(): + assert nonlinsolve([(x**2 + 2*x - y**2)*exp(x), -2*y*exp(x)], x, y + ) == {(-2, 0), (0, 0)} + + +def test_issue_19144(): + # test case 1 + expr1 = [x + y - 1, y**2 + 1] + eq1 = [Eq(i, 0) for i in expr1] + soln1 = {(1 - I, I), (1 + I, -I)} + soln_expr1 = nonlinsolve(expr1, [x, y]) + soln_eq1 = nonlinsolve(eq1, [x, y]) + assert soln_eq1 == soln_expr1 == soln1 + # test case 2 - with denoms + expr2 = [x/y - 1, y**2 + 1] + eq2 = [Eq(i, 0) for i in expr2] + soln2 = {(-I, -I), (I, I)} + soln_expr2 = nonlinsolve(expr2, [x, y]) + soln_eq2 = nonlinsolve(eq2, [x, y]) + assert soln_eq2 == soln_expr2 == soln2 + # denominators that cancel in expression + assert nonlinsolve([Eq(x + 1/x, 1/x)], [x]) == FiniteSet((S.EmptySet,)) + + +def test_issue_22413(): + res = nonlinsolve((4*y*(2*x + 2*exp(y) + 1)*exp(2*x), + 4*x*exp(2*x) + 4*y*exp(2*x + y) + 4*exp(2*x + y) + 1), + x, y) + # First solution is not correct, but the issue was an exception + sols = FiniteSet((x, S.Zero), (-exp(y) - S.Half, y)) + assert res == sols + + +def test_issue_23318(): + eqs_eq = [ + Eq(53.5780461486929, x * log(y / (5.0 - y) + 1) / y), + Eq(x, 0.0015 * z), + Eq(0.0015, 7845.32 * y / z), + ] + eqs_expr = [eq.lhs - eq.rhs for eq in eqs_eq] + + sol = {(266.97755814852, 0.0340301680681629, 177985.03876568)} + + assert_close_nl(nonlinsolve(eqs_eq, [x, y, z]), sol) + assert_close_nl(nonlinsolve(eqs_expr, [x, y, z]), sol) + + logterm = log(1.91196789933362e-7*z/(5.0 - 1.91196789933362e-7*z) + 1) + eq = -0.0015*z*logterm + 1.02439504345316e-5*z + assert_close_ss(solveset(eq, z), {0, 177985.038765679}) + + +def test_issue_19814(): + assert nonlinsolve([ 2**m - 2**(2*n), 4*2**m - 2**(4*n)], m, n + ) == FiniteSet((log(2**(2*n))/log(2), S.Complexes)) + + +def test_issue_22058(): + sol = solveset(-sqrt(t)*x**2 + 2*x + sqrt(t), x, S.Reals) + # doesn't fail (and following numerical check) + assert sol.xreplace({t: 1}) == {1 - sqrt(2), 1 + sqrt(2)}, sol.xreplace({t: 1}) + + +def test_issue_11184(): + assert solveset(20*sqrt(y**2 + (sqrt(-(y - 10)*(y + 10)) + 10)**2) - 60, y, S.Reals) is S.EmptySet + + +def test_issue_21890(): + e = S(2)/3 + assert nonlinsolve([4*x**3*y**4 - 2*y, 4*x**4*y**3 - 2*x], x, y) == { + (2**e/(2*y), y), ((-2**e/4 - 2**e*sqrt(3)*I/4)/y, y), + ((-2**e/4 + 2**e*sqrt(3)*I/4)/y, y)} + assert nonlinsolve([(1 - 4*x**2)*exp(-2*x**2 - 2*y**2), + -4*x*y*exp(-2*x**2)*exp(-2*y**2)], x, y) == {(-S(1)/2, 0), (S(1)/2, 0)} + rx, ry = symbols('x y', real=True) + sol = nonlinsolve([4*rx**3*ry**4 - 2*ry, 4*rx**4*ry**3 - 2*rx], rx, ry) + ans = {(2**(S(2)/3)/(2*ry), ry), + ((-2**(S(2)/3)/4 - 2**(S(2)/3)*sqrt(3)*I/4)/ry, ry), + ((-2**(S(2)/3)/4 + 2**(S(2)/3)*sqrt(3)*I/4)/ry, ry)} + assert sol == ans + + +def test_issue_22628(): + assert nonlinsolve([h - 1, k - 1, f - 2, f - 4, -2*k], h, k, f) == S.EmptySet + assert nonlinsolve([x**3 - 1, x + y, x**2 - 4], [x, y]) == S.EmptySet + + +def test_issue_25781(): + assert solve(sqrt(x/2) - x) == [0, S.Half] + + +def test_issue_26077(): + _n = Symbol('_n') + function = x*cot(5*x) + critical_points = stationary_points(function, x, S.Reals) + excluded_points = Union( + ImageSet(Lambda(_n, 2*_n*pi/5), S.Integers), + ImageSet(Lambda(_n, 2*_n*pi/5 + pi/5), S.Integers) + ) + solution = ConditionSet(x, + Eq(x*(-5*cot(5*x)**2 - 5) + cot(5*x), 0), + Complement(S.Reals, excluded_points) + ) + assert solution.as_dummy() == critical_points.as_dummy() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..adb79261954924305c1837555d7d47cd53b8430b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/__init__.py @@ -0,0 +1,202 @@ +""" +SymPy statistics module + +Introduces a random variable type into the SymPy language. + +Random variables may be declared using prebuilt functions such as +Normal, Exponential, Coin, Die, etc... or built with functions like FiniteRV. + +Queries on random expressions can be made using the functions + +========================= ============================= + Expression Meaning +------------------------- ----------------------------- + ``P(condition)`` Probability + ``E(expression)`` Expected value + ``H(expression)`` Entropy + ``variance(expression)`` Variance + ``density(expression)`` Probability Density Function + ``sample(expression)`` Produce a realization + ``where(condition)`` Where the condition is true +========================= ============================= + +Examples +======== + +>>> from sympy.stats import P, E, variance, Die, Normal +>>> from sympy import simplify +>>> X, Y = Die('X', 6), Die('Y', 6) # Define two six sided dice +>>> Z = Normal('Z', 0, 1) # Declare a Normal random variable with mean 0, std 1 +>>> P(X>3) # Probability X is greater than 3 +1/2 +>>> E(X+Y) # Expectation of the sum of two dice +7 +>>> variance(X+Y) # Variance of the sum of two dice +35/6 +>>> simplify(P(Z>1)) # Probability of Z being greater than 1 +1/2 - erf(sqrt(2)/2)/2 + + +One could also create custom distribution and define custom random variables +as follows: + +1. If you want to create a Continuous Random Variable: + +>>> from sympy.stats import ContinuousRV, P, E +>>> from sympy import exp, Symbol, Interval, oo +>>> x = Symbol('x') +>>> pdf = exp(-x) # pdf of the Continuous Distribution +>>> Z = ContinuousRV(x, pdf, set=Interval(0, oo)) +>>> E(Z) +1 +>>> P(Z > 5) +exp(-5) + +1.1 To create an instance of Continuous Distribution: + +>>> from sympy.stats import ContinuousDistributionHandmade +>>> from sympy import Lambda +>>> dist = ContinuousDistributionHandmade(Lambda(x, pdf), set=Interval(0, oo)) +>>> dist.pdf(x) +exp(-x) + +2. If you want to create a Discrete Random Variable: + +>>> from sympy.stats import DiscreteRV, P, E +>>> from sympy import Symbol, S +>>> p = S(1)/2 +>>> x = Symbol('x', integer=True, positive=True) +>>> pdf = p*(1 - p)**(x - 1) +>>> D = DiscreteRV(x, pdf, set=S.Naturals) +>>> E(D) +2 +>>> P(D > 3) +1/8 + +2.1 To create an instance of Discrete Distribution: + +>>> from sympy.stats import DiscreteDistributionHandmade +>>> from sympy import Lambda +>>> dist = DiscreteDistributionHandmade(Lambda(x, pdf), set=S.Naturals) +>>> dist.pdf(x) +2**(1 - x)/2 + +3. If you want to create a Finite Random Variable: + +>>> from sympy.stats import FiniteRV, P, E +>>> from sympy import Rational, Eq +>>> pmf = {1: Rational(1, 3), 2: Rational(1, 6), 3: Rational(1, 4), 4: Rational(1, 4)} +>>> X = FiniteRV('X', pmf) +>>> E(X) +29/12 +>>> P(X > 3) +1/4 + +3.1 To create an instance of Finite Distribution: + +>>> from sympy.stats import FiniteDistributionHandmade +>>> dist = FiniteDistributionHandmade(pmf) +>>> dist.pmf(x) +Lambda(x, Piecewise((1/3, Eq(x, 1)), (1/6, Eq(x, 2)), (1/4, Eq(x, 3) | Eq(x, 4)), (0, True))) +""" + +__all__ = [ + 'P', 'E', 'H', 'density', 'where', 'given', 'sample', 'cdf','median', + 'characteristic_function', 'pspace', 'sample_iter', 'variance', 'std', + 'skewness', 'kurtosis', 'covariance', 'dependent', 'entropy', 'independent', + 'random_symbols', 'correlation', 'factorial_moment', 'moment', 'cmoment', + 'sampling_density', 'moment_generating_function', 'smoment', 'quantile', + 'coskewness', 'sample_stochastic_process', + + 'FiniteRV', 'DiscreteUniform', 'Die', 'Bernoulli', 'Coin', 'Binomial', + 'BetaBinomial', 'Hypergeometric', 'Rademacher', 'IdealSoliton', 'RobustSoliton', + 'FiniteDistributionHandmade', + + 'ContinuousRV', 'Arcsin', 'Benini', 'Beta', 'BetaNoncentral', 'BetaPrime', + 'BoundedPareto', 'Cauchy', 'Chi', 'ChiNoncentral', 'ChiSquared', 'Dagum', 'Davis', 'Erlang', + 'ExGaussian', 'Exponential', 'ExponentialPower', 'FDistribution', + 'FisherZ', 'Frechet', 'Gamma', 'GammaInverse', 'Gompertz', 'Gumbel', + 'Kumaraswamy', 'Laplace', 'Levy', 'Logistic','LogCauchy', 'LogLogistic', 'LogitNormal', 'LogNormal', 'Lomax', + 'Moyal', 'Maxwell', 'Nakagami', 'Normal', 'GaussianInverse', 'Pareto', 'PowerFunction', + 'QuadraticU', 'RaisedCosine', 'Rayleigh','Reciprocal', 'StudentT', 'ShiftedGompertz', + 'Trapezoidal', 'Triangular', 'Uniform', 'UniformSum', 'VonMises', 'Wald', + 'Weibull', 'WignerSemicircle', 'ContinuousDistributionHandmade', + + 'FlorySchulz', 'Geometric','Hermite', 'Logarithmic', 'NegativeBinomial', 'Poisson', 'Skellam', + 'YuleSimon', 'Zeta', 'DiscreteRV', 'DiscreteDistributionHandmade', + + 'JointRV', 'Dirichlet', 'GeneralizedMultivariateLogGamma', + 'GeneralizedMultivariateLogGammaOmega', 'Multinomial', 'MultivariateBeta', + 'MultivariateEwens', 'MultivariateT', 'NegativeMultinomial', + 'NormalGamma', 'MultivariateNormal', 'MultivariateLaplace', 'marginal_distribution', + + 'StochasticProcess', 'DiscreteTimeStochasticProcess', + 'DiscreteMarkovChain', 'TransitionMatrixOf', 'StochasticStateSpaceOf', + 'GeneratorMatrixOf', 'ContinuousMarkovChain', 'BernoulliProcess', + 'PoissonProcess', 'WienerProcess', 'GammaProcess', + + 'CircularEnsemble', 'CircularUnitaryEnsemble', + 'CircularOrthogonalEnsemble', 'CircularSymplecticEnsemble', + 'GaussianEnsemble', 'GaussianUnitaryEnsemble', + 'GaussianOrthogonalEnsemble', 'GaussianSymplecticEnsemble', + 'joint_eigen_distribution', 'JointEigenDistribution', + 'level_spacing_distribution', + + 'MatrixGamma', 'Wishart', 'MatrixNormal', 'MatrixStudentT', + + 'Probability', 'Expectation', 'Variance', 'Covariance', 'Moment', + 'CentralMoment', + + 'ExpectationMatrix', 'VarianceMatrix', 'CrossCovarianceMatrix' + +] +from .rv_interface import (P, E, H, density, where, given, sample, cdf, median, + characteristic_function, pspace, sample_iter, variance, std, skewness, + kurtosis, covariance, dependent, entropy, independent, random_symbols, + correlation, factorial_moment, moment, cmoment, sampling_density, + moment_generating_function, smoment, quantile, coskewness, + sample_stochastic_process) + +from .frv_types import (FiniteRV, DiscreteUniform, Die, Bernoulli, Coin, + Binomial, BetaBinomial, Hypergeometric, Rademacher, + FiniteDistributionHandmade, IdealSoliton, RobustSoliton) + +from .crv_types import (ContinuousRV, Arcsin, Benini, Beta, BetaNoncentral, + BetaPrime, BoundedPareto, Cauchy, Chi, ChiNoncentral, ChiSquared, + Dagum, Davis, Erlang, ExGaussian, Exponential, ExponentialPower, + FDistribution, FisherZ, Frechet, Gamma, GammaInverse, GaussianInverse, + Gompertz, Gumbel, Kumaraswamy, Laplace, Levy, Logistic, LogCauchy, + LogLogistic, LogitNormal, LogNormal, Lomax, Maxwell, Moyal, Nakagami, + Normal, Pareto, QuadraticU, RaisedCosine, Rayleigh, Reciprocal, + StudentT, PowerFunction, ShiftedGompertz, Trapezoidal, Triangular, + Uniform, UniformSum, VonMises, Wald, Weibull, WignerSemicircle, + ContinuousDistributionHandmade) + +from .drv_types import (FlorySchulz, Geometric, Hermite, Logarithmic, NegativeBinomial, Poisson, + Skellam, YuleSimon, Zeta, DiscreteRV, DiscreteDistributionHandmade) + +from .joint_rv_types import (JointRV, Dirichlet, + GeneralizedMultivariateLogGamma, GeneralizedMultivariateLogGammaOmega, + Multinomial, MultivariateBeta, MultivariateEwens, MultivariateT, + NegativeMultinomial, NormalGamma, MultivariateNormal, MultivariateLaplace, + marginal_distribution) + +from .stochastic_process_types import (StochasticProcess, + DiscreteTimeStochasticProcess, DiscreteMarkovChain, + TransitionMatrixOf, StochasticStateSpaceOf, GeneratorMatrixOf, + ContinuousMarkovChain, BernoulliProcess, PoissonProcess, WienerProcess, + GammaProcess) + +from .random_matrix_models import (CircularEnsemble, CircularUnitaryEnsemble, + CircularOrthogonalEnsemble, CircularSymplecticEnsemble, + GaussianEnsemble, GaussianUnitaryEnsemble, GaussianOrthogonalEnsemble, + GaussianSymplecticEnsemble, joint_eigen_distribution, + JointEigenDistribution, level_spacing_distribution) + +from .matrix_distributions import MatrixGamma, Wishart, MatrixNormal, MatrixStudentT + +from .symbolic_probability import (Probability, Expectation, Variance, + Covariance, Moment, CentralMoment) + +from .symbolic_multivariate_probability import (ExpectationMatrix, VarianceMatrix, + CrossCovarianceMatrix) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/compound_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/compound_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..27555f4233fe691bac303800a87736205acbdee6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/compound_rv.py @@ -0,0 +1,223 @@ +from sympy.concrete.summations import Sum +from sympy.core.basic import Basic +from sympy.core.function import Lambda +from sympy.core.symbol import Dummy +from sympy.integrals.integrals import Integral +from sympy.stats.rv import (NamedArgsMixin, random_symbols, _symbol_converter, + PSpace, RandomSymbol, is_random, Distribution) +from sympy.stats.crv import ContinuousDistribution, SingleContinuousPSpace +from sympy.stats.drv import DiscreteDistribution, SingleDiscretePSpace +from sympy.stats.frv import SingleFiniteDistribution, SingleFinitePSpace +from sympy.stats.crv_types import ContinuousDistributionHandmade +from sympy.stats.drv_types import DiscreteDistributionHandmade +from sympy.stats.frv_types import FiniteDistributionHandmade + + +class CompoundPSpace(PSpace): + """ + A temporary Probability Space for the Compound Distribution. After + Marginalization, this returns the corresponding Probability Space of the + parent distribution. + """ + + def __new__(cls, s, distribution): + s = _symbol_converter(s) + if isinstance(distribution, ContinuousDistribution): + return SingleContinuousPSpace(s, distribution) + if isinstance(distribution, DiscreteDistribution): + return SingleDiscretePSpace(s, distribution) + if isinstance(distribution, SingleFiniteDistribution): + return SingleFinitePSpace(s, distribution) + if not isinstance(distribution, CompoundDistribution): + raise ValueError("%s should be an isinstance of " + "CompoundDistribution"%(distribution)) + return Basic.__new__(cls, s, distribution) + + @property + def value(self): + return RandomSymbol(self.symbol, self) + + @property + def symbol(self): + return self.args[0] + + @property + def is_Continuous(self): + return self.distribution.is_Continuous + + @property + def is_Finite(self): + return self.distribution.is_Finite + + @property + def is_Discrete(self): + return self.distribution.is_Discrete + + @property + def distribution(self): + return self.args[1] + + @property + def pdf(self): + return self.distribution.pdf(self.symbol) + + @property + def set(self): + return self.distribution.set + + @property + def domain(self): + return self._get_newpspace().domain + + def _get_newpspace(self, evaluate=False): + x = Dummy('x') + parent_dist = self.distribution.args[0] + func = Lambda(x, self.distribution.pdf(x, evaluate)) + new_pspace = self._transform_pspace(self.symbol, parent_dist, func) + if new_pspace is not None: + return new_pspace + message = ("Compound Distribution for %s is not implemented yet" % str(parent_dist)) + raise NotImplementedError(message) + + def _transform_pspace(self, sym, dist, pdf): + """ + This function returns the new pspace of the distribution using handmade + Distributions and their corresponding pspace. + """ + pdf = Lambda(sym, pdf(sym)) + _set = dist.set + if isinstance(dist, ContinuousDistribution): + return SingleContinuousPSpace(sym, ContinuousDistributionHandmade(pdf, _set)) + elif isinstance(dist, DiscreteDistribution): + return SingleDiscretePSpace(sym, DiscreteDistributionHandmade(pdf, _set)) + elif isinstance(dist, SingleFiniteDistribution): + dens = {k: pdf(k) for k in _set} + return SingleFinitePSpace(sym, FiniteDistributionHandmade(dens)) + + def compute_density(self, expr, *, compound_evaluate=True, **kwargs): + new_pspace = self._get_newpspace(compound_evaluate) + expr = expr.subs({self.value: new_pspace.value}) + return new_pspace.compute_density(expr, **kwargs) + + def compute_cdf(self, expr, *, compound_evaluate=True, **kwargs): + new_pspace = self._get_newpspace(compound_evaluate) + expr = expr.subs({self.value: new_pspace.value}) + return new_pspace.compute_cdf(expr, **kwargs) + + def compute_expectation(self, expr, rvs=None, evaluate=False, **kwargs): + new_pspace = self._get_newpspace(evaluate) + expr = expr.subs({self.value: new_pspace.value}) + if rvs: + rvs = rvs.subs({self.value: new_pspace.value}) + if isinstance(new_pspace, SingleFinitePSpace): + return new_pspace.compute_expectation(expr, rvs, **kwargs) + return new_pspace.compute_expectation(expr, rvs, evaluate, **kwargs) + + def probability(self, condition, *, compound_evaluate=True, **kwargs): + new_pspace = self._get_newpspace(compound_evaluate) + condition = condition.subs({self.value: new_pspace.value}) + return new_pspace.probability(condition) + + def conditional_space(self, condition, *, compound_evaluate=True, **kwargs): + new_pspace = self._get_newpspace(compound_evaluate) + condition = condition.subs({self.value: new_pspace.value}) + return new_pspace.conditional_space(condition) + + +class CompoundDistribution(Distribution, NamedArgsMixin): + """ + Class for Compound Distributions. + + Parameters + ========== + + dist : Distribution + Distribution must contain a random parameter + + Examples + ======== + + >>> from sympy.stats.compound_rv import CompoundDistribution + >>> from sympy.stats.crv_types import NormalDistribution + >>> from sympy.stats import Normal + >>> from sympy.abc import x + >>> X = Normal('X', 2, 4) + >>> N = NormalDistribution(X, 4) + >>> C = CompoundDistribution(N) + >>> C.set + Interval(-oo, oo) + >>> C.pdf(x, evaluate=True).simplify() + exp(-x**2/64 + x/16 - 1/16)/(8*sqrt(pi)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Compound_probability_distribution + + """ + + def __new__(cls, dist): + if not isinstance(dist, (ContinuousDistribution, + SingleFiniteDistribution, DiscreteDistribution)): + message = "Compound Distribution for %s is not implemented yet" % str(dist) + raise NotImplementedError(message) + if not cls._compound_check(dist): + return dist + return Basic.__new__(cls, dist) + + @property + def set(self): + return self.args[0].set + + @property + def is_Continuous(self): + return isinstance(self.args[0], ContinuousDistribution) + + @property + def is_Finite(self): + return isinstance(self.args[0], SingleFiniteDistribution) + + @property + def is_Discrete(self): + return isinstance(self.args[0], DiscreteDistribution) + + def pdf(self, x, evaluate=False): + dist = self.args[0] + randoms = [rv for rv in dist.args if is_random(rv)] + if isinstance(dist, SingleFiniteDistribution): + y = Dummy('y', integer=True, negative=False) + expr = dist.pmf(y) + else: + y = Dummy('y') + expr = dist.pdf(y) + for rv in randoms: + expr = self._marginalise(expr, rv, evaluate) + return Lambda(y, expr)(x) + + def _marginalise(self, expr, rv, evaluate): + if isinstance(rv.pspace.distribution, SingleFiniteDistribution): + rv_dens = rv.pspace.distribution.pmf(rv) + else: + rv_dens = rv.pspace.distribution.pdf(rv) + rv_dom = rv.pspace.domain.set + if rv.pspace.is_Discrete or rv.pspace.is_Finite: + expr = Sum(expr*rv_dens, (rv, rv_dom._inf, + rv_dom._sup)) + else: + expr = Integral(expr*rv_dens, (rv, rv_dom._inf, + rv_dom._sup)) + if evaluate: + return expr.doit() + return expr + + @classmethod + def _compound_check(self, dist): + """ + Checks if the given distribution contains random parameters. + """ + randoms = [] + for arg in dist.args: + randoms.extend(random_symbols(arg)) + if len(randoms) == 0: + return False + return True diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/crv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/crv.py new file mode 100644 index 0000000000000000000000000000000000000000..0a5184029679f663c83d81aa6c1b6ca4d948c70f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/crv.py @@ -0,0 +1,570 @@ +""" +Continuous Random Variables Module + +See Also +======== +sympy.stats.crv_types +sympy.stats.rv +sympy.stats.frv +""" + + +from sympy.core.basic import Basic +from sympy.core.cache import cacheit +from sympy.core.function import Lambda, PoleError +from sympy.core.numbers import (I, nan, oo) +from sympy.core.relational import (Eq, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, symbols) +from sympy.core.sympify import _sympify, sympify +from sympy.functions.combinatorial.factorials import factorial +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.delta_functions import DiracDelta +from sympy.integrals.integrals import (Integral, integrate) +from sympy.logic.boolalg import (And, Or) +from sympy.polys.polyerrors import PolynomialError +from sympy.polys.polytools import poly +from sympy.series.series import series +from sympy.sets.sets import (FiniteSet, Intersection, Interval, Union) +from sympy.solvers.solveset import solveset +from sympy.solvers.inequalities import reduce_rational_inequalities +from sympy.stats.rv import (RandomDomain, SingleDomain, ConditionalDomain, is_random, + ProductDomain, PSpace, SinglePSpace, random_symbols, NamedArgsMixin, Distribution) + + +class ContinuousDomain(RandomDomain): + """ + A domain with continuous support + + Represented using symbols and Intervals. + """ + is_Continuous = True + + def as_boolean(self): + raise NotImplementedError("Not Implemented for generic Domains") + + +class SingleContinuousDomain(ContinuousDomain, SingleDomain): + """ + A univariate domain with continuous support + + Represented using a single symbol and interval. + """ + def compute_expectation(self, expr, variables=None, **kwargs): + if variables is None: + variables = self.symbols + if not variables: + return expr + if frozenset(variables) != frozenset(self.symbols): + raise ValueError("Values should be equal") + # assumes only intervals + return Integral(expr, (self.symbol, self.set), **kwargs) + + def as_boolean(self): + return self.set.as_relational(self.symbol) + + +class ProductContinuousDomain(ProductDomain, ContinuousDomain): + """ + A collection of independent domains with continuous support + """ + + def compute_expectation(self, expr, variables=None, **kwargs): + if variables is None: + variables = self.symbols + for domain in self.domains: + domain_vars = frozenset(variables) & frozenset(domain.symbols) + if domain_vars: + expr = domain.compute_expectation(expr, domain_vars, **kwargs) + return expr + + def as_boolean(self): + return And(*[domain.as_boolean() for domain in self.domains]) + + +class ConditionalContinuousDomain(ContinuousDomain, ConditionalDomain): + """ + A domain with continuous support that has been further restricted by a + condition such as $x > 3$. + """ + + def compute_expectation(self, expr, variables=None, **kwargs): + if variables is None: + variables = self.symbols + if not variables: + return expr + # Extract the full integral + fullintgrl = self.fulldomain.compute_expectation(expr, variables) + # separate into integrand and limits + integrand, limits = fullintgrl.function, list(fullintgrl.limits) + + conditions = [self.condition] + while conditions: + cond = conditions.pop() + if cond.is_Boolean: + if isinstance(cond, And): + conditions.extend(cond.args) + elif isinstance(cond, Or): + raise NotImplementedError("Or not implemented here") + elif cond.is_Relational: + if cond.is_Equality: + # Add the appropriate Delta to the integrand + integrand *= DiracDelta(cond.lhs - cond.rhs) + else: + symbols = cond.free_symbols & set(self.symbols) + if len(symbols) != 1: # Can't handle x > y + raise NotImplementedError( + "Multivariate Inequalities not yet implemented") + # Can handle x > 0 + symbol = symbols.pop() + # Find the limit with x, such as (x, -oo, oo) + for i, limit in enumerate(limits): + if limit[0] == symbol: + # Make condition into an Interval like [0, oo] + cintvl = reduce_rational_inequalities_wrap( + cond, symbol) + # Make limit into an Interval like [-oo, oo] + lintvl = Interval(limit[1], limit[2]) + # Intersect them to get [0, oo] + intvl = cintvl.intersect(lintvl) + # Put back into limits list + limits[i] = (symbol, intvl.left, intvl.right) + else: + raise TypeError( + "Condition %s is not a relational or Boolean" % cond) + + return Integral(integrand, *limits, **kwargs) + + def as_boolean(self): + return And(self.fulldomain.as_boolean(), self.condition) + + @property + def set(self): + if len(self.symbols) == 1: + return (self.fulldomain.set & reduce_rational_inequalities_wrap( + self.condition, tuple(self.symbols)[0])) + else: + raise NotImplementedError( + "Set of Conditional Domain not Implemented") + + +class ContinuousDistribution(Distribution): + def __call__(self, *args): + return self.pdf(*args) + + +class SingleContinuousDistribution(ContinuousDistribution, NamedArgsMixin): + """ Continuous distribution of a single variable. + + Explanation + =========== + + Serves as superclass for Normal/Exponential/UniformDistribution etc.... + + Represented by parameters for each of the specific classes. E.g + NormalDistribution is represented by a mean and standard deviation. + + Provides methods for pdf, cdf, and sampling. + + See Also + ======== + + sympy.stats.crv_types.* + """ + + set = Interval(-oo, oo) + + def __new__(cls, *args): + args = list(map(sympify, args)) + return Basic.__new__(cls, *args) + + @staticmethod + def check(*args): + pass + + @cacheit + def compute_cdf(self, **kwargs): + """ Compute the CDF from the PDF. + + Returns a Lambda. + """ + x, z = symbols('x, z', real=True, cls=Dummy) + left_bound = self.set.start + + # CDF is integral of PDF from left bound to z + pdf = self.pdf(x) + cdf = integrate(pdf.doit(), (x, left_bound, z), **kwargs) + # CDF Ensure that CDF left of left_bound is zero + cdf = Piecewise((cdf, z >= left_bound), (0, True)) + return Lambda(z, cdf) + + def _cdf(self, x): + return None + + def cdf(self, x, **kwargs): + """ Cumulative density function """ + if len(kwargs) == 0: + cdf = self._cdf(x) + if cdf is not None: + return cdf + return self.compute_cdf(**kwargs)(x) + + @cacheit + def compute_characteristic_function(self, **kwargs): + """ Compute the characteristic function from the PDF. + + Returns a Lambda. + """ + x, t = symbols('x, t', real=True, cls=Dummy) + pdf = self.pdf(x) + cf = integrate(exp(I*t*x)*pdf, (x, self.set)) + return Lambda(t, cf) + + def _characteristic_function(self, t): + return None + + def characteristic_function(self, t, **kwargs): + """ Characteristic function """ + if len(kwargs) == 0: + cf = self._characteristic_function(t) + if cf is not None: + return cf + return self.compute_characteristic_function(**kwargs)(t) + + @cacheit + def compute_moment_generating_function(self, **kwargs): + """ Compute the moment generating function from the PDF. + + Returns a Lambda. + """ + x, t = symbols('x, t', real=True, cls=Dummy) + pdf = self.pdf(x) + mgf = integrate(exp(t * x) * pdf, (x, self.set)) + return Lambda(t, mgf) + + def _moment_generating_function(self, t): + return None + + def moment_generating_function(self, t, **kwargs): + """ Moment generating function """ + if not kwargs: + mgf = self._moment_generating_function(t) + if mgf is not None: + return mgf + return self.compute_moment_generating_function(**kwargs)(t) + + def expectation(self, expr, var, evaluate=True, **kwargs): + """ Expectation of expression over distribution """ + if evaluate: + try: + p = poly(expr, var) + if p.is_zero: + return S.Zero + t = Dummy('t', real=True) + mgf = self._moment_generating_function(t) + if mgf is None: + return integrate(expr * self.pdf(var), (var, self.set), **kwargs) + deg = p.degree() + taylor = poly(series(mgf, t, 0, deg + 1).removeO(), t) + result = 0 + for k in range(deg+1): + result += p.coeff_monomial(var ** k) * taylor.coeff_monomial(t ** k) * factorial(k) + return result + except PolynomialError: + return integrate(expr * self.pdf(var), (var, self.set), **kwargs) + else: + return Integral(expr * self.pdf(var), (var, self.set), **kwargs) + + @cacheit + def compute_quantile(self, **kwargs): + """ Compute the Quantile from the PDF. + + Returns a Lambda. + """ + x, p = symbols('x, p', real=True, cls=Dummy) + left_bound = self.set.start + + pdf = self.pdf(x) + cdf = integrate(pdf, (x, left_bound, x), **kwargs) + quantile = solveset(cdf - p, x, self.set) + return Lambda(p, Piecewise((quantile, (p >= 0) & (p <= 1) ), (nan, True))) + + def _quantile(self, x): + return None + + def quantile(self, x, **kwargs): + """ Cumulative density function """ + if len(kwargs) == 0: + quantile = self._quantile(x) + if quantile is not None: + return quantile + return self.compute_quantile(**kwargs)(x) + + +class ContinuousPSpace(PSpace): + """ Continuous Probability Space + + Represents the likelihood of an event space defined over a continuum. + + Represented with a ContinuousDomain and a PDF (Lambda-Like) + """ + + is_Continuous = True + is_real = True + + @property + def pdf(self): + return self.density(*self.domain.symbols) + + def compute_expectation(self, expr, rvs=None, evaluate=False, **kwargs): + if rvs is None: + rvs = self.values + else: + rvs = frozenset(rvs) + + expr = expr.xreplace({rv: rv.symbol for rv in rvs}) + + domain_symbols = frozenset(rv.symbol for rv in rvs) + + return self.domain.compute_expectation(self.pdf * expr, + domain_symbols, **kwargs) + + def compute_density(self, expr, **kwargs): + # Common case Density(X) where X in self.values + if expr in self.values: + # Marginalize all other random symbols out of the density + randomsymbols = tuple(set(self.values) - frozenset([expr])) + symbols = tuple(rs.symbol for rs in randomsymbols) + pdf = self.domain.compute_expectation(self.pdf, symbols, **kwargs) + return Lambda(expr.symbol, pdf) + + z = Dummy('z', real=True) + return Lambda(z, self.compute_expectation(DiracDelta(expr - z), **kwargs)) + + @cacheit + def compute_cdf(self, expr, **kwargs): + if not self.domain.set.is_Interval: + raise ValueError( + "CDF not well defined on multivariate expressions") + + d = self.compute_density(expr, **kwargs) + x, z = symbols('x, z', real=True, cls=Dummy) + left_bound = self.domain.set.start + + # CDF is integral of PDF from left bound to z + cdf = integrate(d(x), (x, left_bound, z), **kwargs) + # CDF Ensure that CDF left of left_bound is zero + cdf = Piecewise((cdf, z >= left_bound), (0, True)) + return Lambda(z, cdf) + + @cacheit + def compute_characteristic_function(self, expr, **kwargs): + if not self.domain.set.is_Interval: + raise NotImplementedError("Characteristic function of multivariate expressions not implemented") + + d = self.compute_density(expr, **kwargs) + x, t = symbols('x, t', real=True, cls=Dummy) + cf = integrate(exp(I*t*x)*d(x), (x, -oo, oo), **kwargs) + return Lambda(t, cf) + + @cacheit + def compute_moment_generating_function(self, expr, **kwargs): + if not self.domain.set.is_Interval: + raise NotImplementedError("Moment generating function of multivariate expressions not implemented") + + d = self.compute_density(expr, **kwargs) + x, t = symbols('x, t', real=True, cls=Dummy) + mgf = integrate(exp(t * x) * d(x), (x, -oo, oo), **kwargs) + return Lambda(t, mgf) + + @cacheit + def compute_quantile(self, expr, **kwargs): + if not self.domain.set.is_Interval: + raise ValueError( + "Quantile not well defined on multivariate expressions") + + d = self.compute_cdf(expr, **kwargs) + x = Dummy('x', real=True) + p = Dummy('p', positive=True) + + quantile = solveset(d(x) - p, x, self.set) + + return Lambda(p, quantile) + + def probability(self, condition, **kwargs): + z = Dummy('z', real=True) + cond_inv = False + if isinstance(condition, Ne): + condition = Eq(condition.args[0], condition.args[1]) + cond_inv = True + # Univariate case can be handled by where + try: + domain = self.where(condition) + rv = [rv for rv in self.values if rv.symbol == domain.symbol][0] + # Integrate out all other random variables + pdf = self.compute_density(rv, **kwargs) + # return S.Zero if `domain` is empty set + if domain.set is S.EmptySet or isinstance(domain.set, FiniteSet): + return S.Zero if not cond_inv else S.One + if isinstance(domain.set, Union): + return sum( + Integral(pdf(z), (z, subset), **kwargs) for subset in + domain.set.args if isinstance(subset, Interval)) + # Integrate out the last variable over the special domain + return Integral(pdf(z), (z, domain.set), **kwargs) + + # Other cases can be turned into univariate case + # by computing a density handled by density computation + except NotImplementedError: + from sympy.stats.rv import density + expr = condition.lhs - condition.rhs + if not is_random(expr): + dens = self.density + comp = condition.rhs + else: + dens = density(expr, **kwargs) + comp = 0 + if not isinstance(dens, ContinuousDistribution): + from sympy.stats.crv_types import ContinuousDistributionHandmade + dens = ContinuousDistributionHandmade(dens, set=self.domain.set) + # Turn problem into univariate case + space = SingleContinuousPSpace(z, dens) + result = space.probability(condition.__class__(space.value, comp)) + return result if not cond_inv else S.One - result + + def where(self, condition): + rvs = frozenset(random_symbols(condition)) + if not (len(rvs) == 1 and rvs.issubset(self.values)): + raise NotImplementedError( + "Multiple continuous random variables not supported") + rv = tuple(rvs)[0] + interval = reduce_rational_inequalities_wrap(condition, rv) + interval = interval.intersect(self.domain.set) + return SingleContinuousDomain(rv.symbol, interval) + + def conditional_space(self, condition, normalize=True, **kwargs): + condition = condition.xreplace({rv: rv.symbol for rv in self.values}) + domain = ConditionalContinuousDomain(self.domain, condition) + if normalize: + # create a clone of the variable to + # make sure that variables in nested integrals are different + # from the variables outside the integral + # this makes sure that they are evaluated separately + # and in the correct order + replacement = {rv: Dummy(str(rv)) for rv in self.symbols} + norm = domain.compute_expectation(self.pdf, **kwargs) + pdf = self.pdf / norm.xreplace(replacement) + # XXX: Converting set to tuple. The order matters to Lambda though + # so we shouldn't be starting with a set here... + density = Lambda(tuple(domain.symbols), pdf) + + return ContinuousPSpace(domain, density) + + +class SingleContinuousPSpace(ContinuousPSpace, SinglePSpace): + """ + A continuous probability space over a single univariate variable. + + These consist of a Symbol and a SingleContinuousDistribution + + This class is normally accessed through the various random variable + functions, Normal, Exponential, Uniform, etc.... + """ + + @property + def set(self): + return self.distribution.set + + @property + def domain(self): + return SingleContinuousDomain(sympify(self.symbol), self.set) + + def sample(self, size=(), library='scipy', seed=None): + """ + Internal sample method. + + Returns dictionary mapping RandomSymbol to realization value. + """ + return {self.value: self.distribution.sample(size, library=library, seed=seed)} + + def compute_expectation(self, expr, rvs=None, evaluate=False, **kwargs): + rvs = rvs or (self.value,) + if self.value not in rvs: + return expr + + expr = _sympify(expr) + expr = expr.xreplace({rv: rv.symbol for rv in rvs}) + + x = self.value.symbol + try: + return self.distribution.expectation(expr, x, evaluate=evaluate, **kwargs) + except PoleError: + return Integral(expr * self.pdf, (x, self.set), **kwargs) + + def compute_cdf(self, expr, **kwargs): + if expr == self.value: + z = Dummy("z", real=True) + return Lambda(z, self.distribution.cdf(z, **kwargs)) + else: + return ContinuousPSpace.compute_cdf(self, expr, **kwargs) + + def compute_characteristic_function(self, expr, **kwargs): + if expr == self.value: + t = Dummy("t", real=True) + return Lambda(t, self.distribution.characteristic_function(t, **kwargs)) + else: + return ContinuousPSpace.compute_characteristic_function(self, expr, **kwargs) + + def compute_moment_generating_function(self, expr, **kwargs): + if expr == self.value: + t = Dummy("t", real=True) + return Lambda(t, self.distribution.moment_generating_function(t, **kwargs)) + else: + return ContinuousPSpace.compute_moment_generating_function(self, expr, **kwargs) + + def compute_density(self, expr, **kwargs): + # https://en.wikipedia.org/wiki/Random_variable#Functions_of_random_variables + if expr == self.value: + return self.density + y = Dummy('y', real=True) + + gs = solveset(expr - y, self.value, S.Reals) + + if isinstance(gs, Intersection): + if len(gs.args) == 2 and gs.args[0] is S.Reals: + gs = gs.args[1] + if not gs.is_FiniteSet: + raise ValueError("Can not solve %s for %s" % (expr, self.value)) + fx = self.compute_density(self.value) + fy = sum(fx(g) * abs(g.diff(y)) for g in gs) + return Lambda(y, fy) + + def compute_quantile(self, expr, **kwargs): + + if expr == self.value: + p = Dummy("p", real=True) + return Lambda(p, self.distribution.quantile(p, **kwargs)) + else: + return ContinuousPSpace.compute_quantile(self, expr, **kwargs) + +def _reduce_inequalities(conditions, var, **kwargs): + try: + return reduce_rational_inequalities(conditions, var, **kwargs) + except PolynomialError: + raise ValueError("Reduction of condition failed %s\n" % conditions[0]) + + +def reduce_rational_inequalities_wrap(condition, var): + if condition.is_Relational: + return _reduce_inequalities([[condition]], var, relational=False) + if isinstance(condition, Or): + return Union(*[_reduce_inequalities([[arg]], var, relational=False) + for arg in condition.args]) + if isinstance(condition, And): + intervals = [_reduce_inequalities([[arg]], var, relational=False) + for arg in condition.args] + I = intervals[0] + for i in intervals: + I = I.intersect(i) + return I diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/crv_types.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/crv_types.py new file mode 100644 index 0000000000000000000000000000000000000000..073e7350fdf80aac39ecd1dd607488a8b76187e3 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/crv_types.py @@ -0,0 +1,4732 @@ +""" +Continuous Random Variables - Prebuilt variables + +Contains +======== +Arcsin +Benini +Beta +BetaNoncentral +BetaPrime +BoundedPareto +Cauchy +Chi +ChiNoncentral +ChiSquared +Dagum +Davis +Erlang +ExGaussian +Exponential +ExponentialPower +FDistribution +FisherZ +Frechet +Gamma +GammaInverse +Gumbel +Gompertz +Kumaraswamy +Laplace +Levy +LogCauchy +Logistic +LogLogistic +LogitNormal +LogNormal +Lomax +Maxwell +Moyal +Nakagami +Normal +Pareto +PowerFunction +QuadraticU +RaisedCosine +Rayleigh +Reciprocal +ShiftedGompertz +StudentT +Trapezoidal +Triangular +Uniform +UniformSum +VonMises +Wald +Weibull +WignerSemicircle +""" + + + +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.trigonometric import (atan, cos, sin, tan) +from sympy.functions.special.bessel import (besseli, besselj, besselk) +from sympy.functions.special.beta_functions import beta as beta_fn +from sympy.concrete.summations import Sum +from sympy.core.basic import Basic +from sympy.core.function import Lambda +from sympy.core.numbers import (I, Rational, pi) +from sympy.core.relational import (Eq, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import Dummy +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import (binomial, factorial) +from sympy.functions.elementary.complexes import (Abs, sign) +from sympy.functions.elementary.exponential import log +from sympy.functions.elementary.hyperbolic import sinh +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.miscellaneous import sqrt, Max, Min +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import asin +from sympy.functions.special.error_functions import (erf, erfc, erfi, erfinv, expint) +from sympy.functions.special.gamma_functions import (gamma, lowergamma, uppergamma) +from sympy.functions.special.zeta_functions import zeta +from sympy.functions.special.hyper import hyper +from sympy.integrals.integrals import integrate +from sympy.logic.boolalg import And +from sympy.sets.sets import Interval +from sympy.matrices import MatrixBase +from sympy.stats.crv import SingleContinuousPSpace, SingleContinuousDistribution +from sympy.stats.rv import _value_check, is_random + +oo = S.Infinity + +__all__ = ['ContinuousRV', +'Arcsin', +'Benini', +'Beta', +'BetaNoncentral', +'BetaPrime', +'BoundedPareto', +'Cauchy', +'Chi', +'ChiNoncentral', +'ChiSquared', +'Dagum', +'Davis', +'Erlang', +'ExGaussian', +'Exponential', +'ExponentialPower', +'FDistribution', +'FisherZ', +'Frechet', +'Gamma', +'GammaInverse', +'Gompertz', +'Gumbel', +'Kumaraswamy', +'Laplace', +'Levy', +'LogCauchy', +'Logistic', +'LogLogistic', +'LogitNormal', +'LogNormal', +'Lomax', +'Maxwell', +'Moyal', +'Nakagami', +'Normal', +'GaussianInverse', +'Pareto', +'PowerFunction', +'QuadraticU', +'RaisedCosine', +'Rayleigh', +'Reciprocal', +'StudentT', +'ShiftedGompertz', +'Trapezoidal', +'Triangular', +'Uniform', +'UniformSum', +'VonMises', +'Wald', +'Weibull', +'WignerSemicircle', +] + + +@is_random.register(MatrixBase) +def _(x): + return any(is_random(i) for i in x) + +def rv(symbol, cls, args, **kwargs): + args = list(map(sympify, args)) + dist = cls(*args) + if kwargs.pop('check', True): + dist.check(*args) + pspace = SingleContinuousPSpace(symbol, dist) + if any(is_random(arg) for arg in args): + from sympy.stats.compound_rv import CompoundPSpace, CompoundDistribution + pspace = CompoundPSpace(symbol, CompoundDistribution(dist)) + return pspace.value + + +class ContinuousDistributionHandmade(SingleContinuousDistribution): + _argnames = ('pdf',) + + def __new__(cls, pdf, set=Interval(-oo, oo)): + return Basic.__new__(cls, pdf, set) + + @property + def set(self): + return self.args[1] + + @staticmethod + def check(pdf, set): + x = Dummy('x') + val = integrate(pdf(x), (x, set)) + _value_check(Eq(val, 1) != S.false, "The pdf on the given set is incorrect.") + + +def ContinuousRV(symbol, density, set=Interval(-oo, oo), **kwargs): + """ + Create a Continuous Random Variable given the following: + + Parameters + ========== + + symbol : Symbol + Represents name of the random variable. + density : Expression containing symbol + Represents probability density function. + set : set/Interval + Represents the region where the pdf is valid, by default is real line. + check : bool + If True, it will check whether the given density + integrates to 1 over the given set. If False, it + will not perform this check. Default is False. + + + Returns + ======= + + RandomSymbol + + Many common continuous random variable types are already implemented. + This function should be necessary only very rarely. + + + Examples + ======== + + >>> from sympy import Symbol, sqrt, exp, pi + >>> from sympy.stats import ContinuousRV, P, E + + >>> x = Symbol("x") + + >>> pdf = sqrt(2)*exp(-x**2/2)/(2*sqrt(pi)) # Normal distribution + >>> X = ContinuousRV(x, pdf) + + >>> E(X) + 0 + >>> P(X>0) + 1/2 + """ + pdf = Piecewise((density, set.as_relational(symbol)), (0, True)) + pdf = Lambda(symbol, pdf) + # have a default of False while `rv` should have a default of True + kwargs['check'] = kwargs.pop('check', False) + return rv(symbol.name, ContinuousDistributionHandmade, (pdf, set), **kwargs) + +######################################## +# Continuous Probability Distributions # +######################################## + +#------------------------------------------------------------------------------- +# Arcsin distribution ---------------------------------------------------------- + + +class ArcsinDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b') + + @property + def set(self): + return Interval(self.a, self.b) + + def pdf(self, x): + a, b = self.a, self.b + return 1/(pi*sqrt((x - a)*(b - x))) + + def _cdf(self, x): + a, b = self.a, self.b + return Piecewise( + (S.Zero, x < a), + (2*asin(sqrt((x - a)/(b - a)))/pi, x <= b), + (S.One, True)) + + +def Arcsin(name, a=0, b=1): + r""" + Create a Continuous Random Variable with an arcsin distribution. + + The density of the arcsin distribution is given by + + .. math:: + f(x) := \frac{1}{\pi\sqrt{(x-a)(b-x)}} + + with :math:`x \in (a,b)`. It must hold that :math:`-\infty < a < b < \infty`. + + Parameters + ========== + + a : Real number, the left interval boundary + b : Real number, the right interval boundary + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Arcsin, density, cdf + >>> from sympy import Symbol + + >>> a = Symbol("a", real=True) + >>> b = Symbol("b", real=True) + >>> z = Symbol("z") + + >>> X = Arcsin("x", a, b) + + >>> density(X)(z) + 1/(pi*sqrt((-a + z)*(b - z))) + + >>> cdf(X)(z) + Piecewise((0, a > z), + (2*asin(sqrt((-a + z)/(-a + b)))/pi, b >= z), + (1, True)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Arcsine_distribution + + """ + + return rv(name, ArcsinDistribution, (a, b)) + +#------------------------------------------------------------------------------- +# Benini distribution ---------------------------------------------------------- + + +class BeniniDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'beta', 'sigma') + + @staticmethod + def check(alpha, beta, sigma): + _value_check(alpha > 0, "Shape parameter Alpha must be positive.") + _value_check(beta > 0, "Shape parameter Beta must be positive.") + _value_check(sigma > 0, "Scale parameter Sigma must be positive.") + + @property + def set(self): + return Interval(self.sigma, oo) + + def pdf(self, x): + alpha, beta, sigma = self.alpha, self.beta, self.sigma + return (exp(-alpha*log(x/sigma) - beta*log(x/sigma)**2) + *(alpha/x + 2*beta*log(x/sigma)/x)) + + def _moment_generating_function(self, t): + raise NotImplementedError('The moment generating function of the ' + 'Benini distribution does not exist.') + +def Benini(name, alpha, beta, sigma): + r""" + Create a Continuous Random Variable with a Benini distribution. + + The density of the Benini distribution is given by + + .. math:: + f(x) := e^{-\alpha\log{\frac{x}{\sigma}} + -\beta\log^2\left[{\frac{x}{\sigma}}\right]} + \left(\frac{\alpha}{x}+\frac{2\beta\log{\frac{x}{\sigma}}}{x}\right) + + This is a heavy-tailed distribution and is also known as the log-Rayleigh + distribution. + + Parameters + ========== + + alpha : Real number, `\alpha > 0`, a shape + beta : Real number, `\beta > 0`, a shape + sigma : Real number, `\sigma > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Benini, density, cdf + >>> from sympy import Symbol, pprint + + >>> alpha = Symbol("alpha", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> sigma = Symbol("sigma", positive=True) + >>> z = Symbol("z") + + >>> X = Benini("x", alpha, beta, sigma) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + / / z \\ / z \ 2/ z \ + | 2*beta*log|-----|| - alpha*log|-----| - beta*log |-----| + |alpha \sigma/| \sigma/ \sigma/ + |----- + -----------------|*e + \ z z / + + >>> cdf(X)(z) + Piecewise((1 - exp(-alpha*log(z/sigma) - beta*log(z/sigma)**2), sigma <= z), + (0, True)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Benini_distribution + .. [2] https://reference.wolfram.com/legacy/v8/ref/BeniniDistribution.html + + """ + + return rv(name, BeniniDistribution, (alpha, beta, sigma)) + +#------------------------------------------------------------------------------- +# Beta distribution ------------------------------------------------------------ + + +class BetaDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'beta') + + set = Interval(0, 1) + + @staticmethod + def check(alpha, beta): + _value_check(alpha > 0, "Shape parameter Alpha must be positive.") + _value_check(beta > 0, "Shape parameter Beta must be positive.") + + def pdf(self, x): + alpha, beta = self.alpha, self.beta + return x**(alpha - 1) * (1 - x)**(beta - 1) / beta_fn(alpha, beta) + + def _characteristic_function(self, t): + return hyper((self.alpha,), (self.alpha + self.beta,), I*t) + + def _moment_generating_function(self, t): + return hyper((self.alpha,), (self.alpha + self.beta,), t) + + +def Beta(name, alpha, beta): + r""" + Create a Continuous Random Variable with a Beta distribution. + + The density of the Beta distribution is given by + + .. math:: + f(x) := \frac{x^{\alpha-1}(1-x)^{\beta-1}} {\mathrm{B}(\alpha,\beta)} + + with :math:`x \in [0,1]`. + + Parameters + ========== + + alpha : Real number, `\alpha > 0`, a shape + beta : Real number, `\beta > 0`, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Beta, density, E, variance + >>> from sympy import Symbol, simplify, pprint, factor + + >>> alpha = Symbol("alpha", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> z = Symbol("z") + + >>> X = Beta("x", alpha, beta) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + alpha - 1 beta - 1 + z *(1 - z) + -------------------------- + B(alpha, beta) + + >>> simplify(E(X)) + alpha/(alpha + beta) + + >>> factor(simplify(variance(X))) + alpha*beta/((alpha + beta)**2*(alpha + beta + 1)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Beta_distribution + .. [2] https://mathworld.wolfram.com/BetaDistribution.html + + """ + + return rv(name, BetaDistribution, (alpha, beta)) + +#------------------------------------------------------------------------------- +# Noncentral Beta distribution ------------------------------------------------------------ + + +class BetaNoncentralDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'beta', 'lamda') + + set = Interval(0, 1) + + @staticmethod + def check(alpha, beta, lamda): + _value_check(alpha > 0, "Shape parameter Alpha must be positive.") + _value_check(beta > 0, "Shape parameter Beta must be positive.") + _value_check(lamda >= 0, "Noncentrality parameter Lambda must be positive") + + def pdf(self, x): + alpha, beta, lamda = self.alpha, self.beta, self.lamda + k = Dummy("k") + return Sum(exp(-lamda / 2) * (lamda / 2)**k * x**(alpha + k - 1) *( + 1 - x)**(beta - 1) / (factorial(k) * beta_fn(alpha + k, beta)), (k, 0, oo)) + +def BetaNoncentral(name, alpha, beta, lamda): + r""" + Create a Continuous Random Variable with a Type I Noncentral Beta distribution. + + The density of the Noncentral Beta distribution is given by + + .. math:: + f(x) := \sum_{k=0}^\infty e^{-\lambda/2}\frac{(\lambda/2)^k}{k!} + \frac{x^{\alpha+k-1}(1-x)^{\beta-1}}{\mathrm{B}(\alpha+k,\beta)} + + with :math:`x \in [0,1]`. + + Parameters + ========== + + alpha : Real number, `\alpha > 0`, a shape + beta : Real number, `\beta > 0`, a shape + lamda : Real number, `\lambda \geq 0`, noncentrality parameter + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import BetaNoncentral, density, cdf + >>> from sympy import Symbol, pprint + + >>> alpha = Symbol("alpha", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> lamda = Symbol("lamda", nonnegative=True) + >>> z = Symbol("z") + + >>> X = BetaNoncentral("x", alpha, beta, lamda) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + oo + _____ + \ ` + \ -lamda + \ k ------- + \ k + alpha - 1 /lamda\ beta - 1 2 + ) z *|-----| *(1 - z) *e + / \ 2 / + / ------------------------------------------------ + / B(k + alpha, beta)*k! + /____, + k = 0 + + Compute cdf with specific 'x', 'alpha', 'beta' and 'lamda' values as follows: + + >>> cdf(BetaNoncentral("x", 1, 1, 1), evaluate=False)(2).doit() + 2*exp(1/2) + + The argument evaluate=False prevents an attempt at evaluation + of the sum for general x, before the argument 2 is passed. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Noncentral_beta_distribution + .. [2] https://reference.wolfram.com/language/ref/NoncentralBetaDistribution.html + + """ + + return rv(name, BetaNoncentralDistribution, (alpha, beta, lamda)) + + +#------------------------------------------------------------------------------- +# Beta prime distribution ------------------------------------------------------ + + +class BetaPrimeDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'beta') + + @staticmethod + def check(alpha, beta): + _value_check(alpha > 0, "Shape parameter Alpha must be positive.") + _value_check(beta > 0, "Shape parameter Beta must be positive.") + + set = Interval(0, oo) + + def pdf(self, x): + alpha, beta = self.alpha, self.beta + return x**(alpha - 1)*(1 + x)**(-alpha - beta)/beta_fn(alpha, beta) + +def BetaPrime(name, alpha, beta): + r""" + Create a continuous random variable with a Beta prime distribution. + + The density of the Beta prime distribution is given by + + .. math:: + f(x) := \frac{x^{\alpha-1} (1+x)^{-\alpha -\beta}}{B(\alpha,\beta)} + + with :math:`x > 0`. + + Parameters + ========== + + alpha : Real number, `\alpha > 0`, a shape + beta : Real number, `\beta > 0`, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import BetaPrime, density + >>> from sympy import Symbol, pprint + + >>> alpha = Symbol("alpha", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> z = Symbol("z") + + >>> X = BetaPrime("x", alpha, beta) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + alpha - 1 -alpha - beta + z *(z + 1) + ------------------------------- + B(alpha, beta) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Beta_prime_distribution + .. [2] https://mathworld.wolfram.com/BetaPrimeDistribution.html + + """ + + return rv(name, BetaPrimeDistribution, (alpha, beta)) + +#------------------------------------------------------------------------------- +# Bounded Pareto Distribution -------------------------------------------------- +class BoundedParetoDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'left', 'right') + + @property + def set(self): + return Interval(self.left, self.right) + + @staticmethod + def check(alpha, left, right): + _value_check (alpha.is_positive, "Shape must be positive.") + _value_check (left.is_positive, "Left value should be positive.") + _value_check (right > left, "Right should be greater than left.") + + def pdf(self, x): + alpha, left, right = self.alpha, self.left, self.right + num = alpha * (left**alpha) * x**(- alpha -1) + den = 1 - (left/right)**alpha + return num/den + +def BoundedPareto(name, alpha, left, right): + r""" + Create a continuous random variable with a Bounded Pareto distribution. + + The density of the Bounded Pareto distribution is given by + + .. math:: + f(x) := \frac{\alpha L^{\alpha}x^{-\alpha-1}}{1-(\frac{L}{H})^{\alpha}} + + Parameters + ========== + + alpha : Real Number, `\alpha > 0` + Shape parameter + left : Real Number, `left > 0` + Location parameter + right : Real Number, `right > left` + Location parameter + + Examples + ======== + + >>> from sympy.stats import BoundedPareto, density, cdf, E + >>> from sympy import symbols + >>> L, H = symbols('L, H', positive=True) + >>> X = BoundedPareto('X', 2, L, H) + >>> x = symbols('x') + >>> density(X)(x) + 2*L**2/(x**3*(1 - L**2/H**2)) + >>> cdf(X)(x) + Piecewise((-H**2*L**2/(x**2*(H**2 - L**2)) + H**2/(H**2 - L**2), L <= x), (0, True)) + >>> E(X).simplify() + 2*H*L/(H + L) + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Pareto_distribution#Bounded_Pareto_distribution + + """ + return rv (name, BoundedParetoDistribution, (alpha, left, right)) + +# ------------------------------------------------------------------------------ +# Cauchy distribution ---------------------------------------------------------- + + +class CauchyDistribution(SingleContinuousDistribution): + _argnames = ('x0', 'gamma') + + @staticmethod + def check(x0, gamma): + _value_check(gamma > 0, "Scale parameter Gamma must be positive.") + _value_check(x0.is_real, "Location parameter must be real.") + + def pdf(self, x): + return 1/(pi*self.gamma*(1 + ((x - self.x0)/self.gamma)**2)) + + def _cdf(self, x): + x0, gamma = self.x0, self.gamma + return (1/pi)*atan((x - x0)/gamma) + S.Half + + def _characteristic_function(self, t): + return exp(self.x0 * I * t - self.gamma * Abs(t)) + + def _moment_generating_function(self, t): + raise NotImplementedError("The moment generating function for the " + "Cauchy distribution does not exist.") + + def _quantile(self, p): + return self.x0 + self.gamma*tan(pi*(p - S.Half)) + + +def Cauchy(name, x0, gamma): + r""" + Create a continuous random variable with a Cauchy distribution. + + The density of the Cauchy distribution is given by + + .. math:: + f(x) := \frac{1}{\pi \gamma [1 + {(\frac{x-x_0}{\gamma})}^2]} + + Parameters + ========== + + x0 : Real number, the location + gamma : Real number, `\gamma > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Cauchy, density + >>> from sympy import Symbol + + >>> x0 = Symbol("x0") + >>> gamma = Symbol("gamma", positive=True) + >>> z = Symbol("z") + + >>> X = Cauchy("x", x0, gamma) + + >>> density(X)(z) + 1/(pi*gamma*(1 + (-x0 + z)**2/gamma**2)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Cauchy_distribution + .. [2] https://mathworld.wolfram.com/CauchyDistribution.html + + """ + + return rv(name, CauchyDistribution, (x0, gamma)) + +#------------------------------------------------------------------------------- +# Chi distribution ------------------------------------------------------------- + + +class ChiDistribution(SingleContinuousDistribution): + _argnames = ('k',) + + @staticmethod + def check(k): + _value_check(k > 0, "Number of degrees of freedom (k) must be positive.") + _value_check(k.is_integer, "Number of degrees of freedom (k) must be an integer.") + + set = Interval(0, oo) + + def pdf(self, x): + return 2**(1 - self.k/2)*x**(self.k - 1)*exp(-x**2/2)/gamma(self.k/2) + + def _characteristic_function(self, t): + k = self.k + + part_1 = hyper((k/2,), (S.Half,), -t**2/2) + part_2 = I*t*sqrt(2)*gamma((k+1)/2)/gamma(k/2) + part_3 = hyper(((k+1)/2,), (Rational(3, 2),), -t**2/2) + return part_1 + part_2*part_3 + + def _moment_generating_function(self, t): + k = self.k + + part_1 = hyper((k / 2,), (S.Half,), t ** 2 / 2) + part_2 = t * sqrt(2) * gamma((k + 1) / 2) / gamma(k / 2) + part_3 = hyper(((k + 1) / 2,), (S(3) / 2,), t ** 2 / 2) + return part_1 + part_2 * part_3 + +def Chi(name, k): + r""" + Create a continuous random variable with a Chi distribution. + + The density of the Chi distribution is given by + + .. math:: + f(x) := \frac{2^{1-k/2}x^{k-1}e^{-x^2/2}}{\Gamma(k/2)} + + with :math:`x \geq 0`. + + Parameters + ========== + + k : Positive integer, The number of degrees of freedom + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Chi, density, E + >>> from sympy import Symbol, simplify + + >>> k = Symbol("k", integer=True) + >>> z = Symbol("z") + + >>> X = Chi("x", k) + + >>> density(X)(z) + 2**(1 - k/2)*z**(k - 1)*exp(-z**2/2)/gamma(k/2) + + >>> simplify(E(X)) + sqrt(2)*gamma(k/2 + 1/2)/gamma(k/2) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Chi_distribution + .. [2] https://mathworld.wolfram.com/ChiDistribution.html + + """ + + return rv(name, ChiDistribution, (k,)) + +#------------------------------------------------------------------------------- +# Non-central Chi distribution ------------------------------------------------- + + +class ChiNoncentralDistribution(SingleContinuousDistribution): + _argnames = ('k', 'l') + + @staticmethod + def check(k, l): + _value_check(k > 0, "Number of degrees of freedom (k) must be positive.") + _value_check(k.is_integer, "Number of degrees of freedom (k) must be an integer.") + _value_check(l > 0, "Shift parameter Lambda must be positive.") + + set = Interval(0, oo) + + def pdf(self, x): + k, l = self.k, self.l + return exp(-(x**2+l**2)/2)*x**k*l / (l*x)**(k/2) * besseli(k/2-1, l*x) + +def ChiNoncentral(name, k, l): + r""" + Create a continuous random variable with a non-central Chi distribution. + + Explanation + =========== + + The density of the non-central Chi distribution is given by + + .. math:: + f(x) := \frac{e^{-(x^2+\lambda^2)/2} x^k\lambda} + {(\lambda x)^{k/2}} I_{k/2-1}(\lambda x) + + with `x \geq 0`. Here, `I_\nu (x)` is the + :ref:`modified Bessel function of the first kind `. + + Parameters + ========== + + k : A positive Integer, $k > 0$ + The number of degrees of freedom. + lambda : Real number, `\lambda > 0` + Shift parameter. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import ChiNoncentral, density + >>> from sympy import Symbol + + >>> k = Symbol("k", integer=True) + >>> l = Symbol("l") + >>> z = Symbol("z") + + >>> X = ChiNoncentral("x", k, l) + + >>> density(X)(z) + l*z**k*exp(-l**2/2 - z**2/2)*besseli(k/2 - 1, l*z)/(l*z)**(k/2) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Noncentral_chi_distribution + """ + + return rv(name, ChiNoncentralDistribution, (k, l)) + +#------------------------------------------------------------------------------- +# Chi squared distribution ----------------------------------------------------- + + +class ChiSquaredDistribution(SingleContinuousDistribution): + _argnames = ('k',) + + @staticmethod + def check(k): + _value_check(k > 0, "Number of degrees of freedom (k) must be positive.") + _value_check(k.is_integer, "Number of degrees of freedom (k) must be an integer.") + + set = Interval(0, oo) + + def pdf(self, x): + k = self.k + return 1/(2**(k/2)*gamma(k/2))*x**(k/2 - 1)*exp(-x/2) + + def _cdf(self, x): + k = self.k + return Piecewise( + (S.One/gamma(k/2)*lowergamma(k/2, x/2), x >= 0), + (0, True) + ) + + def _characteristic_function(self, t): + return (1 - 2*I*t)**(-self.k/2) + + def _moment_generating_function(self, t): + return (1 - 2*t)**(-self.k/2) + + +def ChiSquared(name, k): + r""" + Create a continuous random variable with a Chi-squared distribution. + + Explanation + =========== + + The density of the Chi-squared distribution is given by + + .. math:: + f(x) := \frac{1}{2^{\frac{k}{2}}\Gamma\left(\frac{k}{2}\right)} + x^{\frac{k}{2}-1} e^{-\frac{x}{2}} + + with :math:`x \geq 0`. + + Parameters + ========== + + k : Positive integer + The number of degrees of freedom. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import ChiSquared, density, E, variance, moment + >>> from sympy import Symbol + + >>> k = Symbol("k", integer=True, positive=True) + >>> z = Symbol("z") + + >>> X = ChiSquared("x", k) + + >>> density(X)(z) + z**(k/2 - 1)*exp(-z/2)/(2**(k/2)*gamma(k/2)) + + >>> E(X) + k + + >>> variance(X) + 2*k + + >>> moment(X, 3) + k**3 + 6*k**2 + 8*k + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Chi_squared_distribution + .. [2] https://mathworld.wolfram.com/Chi-SquaredDistribution.html + """ + + return rv(name, ChiSquaredDistribution, (k, )) + +#------------------------------------------------------------------------------- +# Dagum distribution ----------------------------------------------------------- + + +class DagumDistribution(SingleContinuousDistribution): + _argnames = ('p', 'a', 'b') + + set = Interval(0, oo) + + @staticmethod + def check(p, a, b): + _value_check(p > 0, "Shape parameter p must be positive.") + _value_check(a > 0, "Shape parameter a must be positive.") + _value_check(b > 0, "Scale parameter b must be positive.") + + def pdf(self, x): + p, a, b = self.p, self.a, self.b + return a*p/x*((x/b)**(a*p)/(((x/b)**a + 1)**(p + 1))) + + def _cdf(self, x): + p, a, b = self.p, self.a, self.b + return Piecewise(((S.One + (S(x)/b)**-a)**-p, x>=0), + (S.Zero, True)) + +def Dagum(name, p, a, b): + r""" + Create a continuous random variable with a Dagum distribution. + + Explanation + =========== + + The density of the Dagum distribution is given by + + .. math:: + f(x) := \frac{a p}{x} \left( \frac{\left(\tfrac{x}{b}\right)^{a p}} + {\left(\left(\tfrac{x}{b}\right)^a + 1 \right)^{p+1}} \right) + + with :math:`x > 0`. + + Parameters + ========== + + p : Real number + `p > 0`, a shape. + a : Real number + `a > 0`, a shape. + b : Real number + `b > 0`, a scale. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Dagum, density, cdf + >>> from sympy import Symbol + + >>> p = Symbol("p", positive=True) + >>> a = Symbol("a", positive=True) + >>> b = Symbol("b", positive=True) + >>> z = Symbol("z") + + >>> X = Dagum("x", p, a, b) + + >>> density(X)(z) + a*p*(z/b)**(a*p)*((z/b)**a + 1)**(-p - 1)/z + + >>> cdf(X)(z) + Piecewise(((1 + (z/b)**(-a))**(-p), z >= 0), (0, True)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Dagum_distribution + + """ + + return rv(name, DagumDistribution, (p, a, b)) + +#------------------------------------------------------------------------------- +# Davis distribution ----------------------------------------------------------- + +class DavisDistribution(SingleContinuousDistribution): + _argnames = ('b', 'n', 'mu') + + set = Interval(0, oo) + + @staticmethod + def check(b, n, mu): + _value_check(b > 0, "Scale parameter b must be positive.") + _value_check(n > 1, "Shape parameter n must be above 1.") + _value_check(mu > 0, "Location parameter mu must be positive.") + + def pdf(self, x): + b, n, mu = self.b, self.n, self.mu + dividend = b**n*(x - mu)**(-1-n) + divisor = (exp(b/(x-mu))-1)*(gamma(n)*zeta(n)) + return dividend/divisor + + +def Davis(name, b, n, mu): + r""" Create a continuous random variable with Davis distribution. + + Explanation + =========== + + The density of Davis distribution is given by + + .. math:: + f(x; \mu; b, n) := \frac{b^{n}(x - \mu)^{1-n}}{ \left( e^{\frac{b}{x-\mu}} - 1 \right) \Gamma(n)\zeta(n)} + + with :math:`x \in [0,\infty]`. + + Davis distribution is a generalization of the Planck's law of radiation from statistical physics. It is used for modeling income distribution. + + Parameters + ========== + b : Real number + `p > 0`, a scale. + n : Real number + `n > 1`, a shape. + mu : Real number + `mu > 0`, a location. + + Returns + ======= + + RandomSymbol + + Examples + ======== + >>> from sympy.stats import Davis, density + >>> from sympy import Symbol + >>> b = Symbol("b", positive=True) + >>> n = Symbol("n", positive=True) + >>> mu = Symbol("mu", positive=True) + >>> z = Symbol("z") + >>> X = Davis("x", b, n, mu) + >>> density(X)(z) + b**n*(-mu + z)**(-n - 1)/((exp(b/(-mu + z)) - 1)*gamma(n)*zeta(n)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Davis_distribution + .. [2] https://reference.wolfram.com/language/ref/DavisDistribution.html + + """ + return rv(name, DavisDistribution, (b, n, mu)) + + +#------------------------------------------------------------------------------- +# Erlang distribution ---------------------------------------------------------- + + +def Erlang(name, k, l): + r""" + Create a continuous random variable with an Erlang distribution. + + Explanation + =========== + + The density of the Erlang distribution is given by + + .. math:: + f(x) := \frac{\lambda^k x^{k-1} e^{-\lambda x}}{(k-1)!} + + with :math:`x \in [0,\infty]`. + + Parameters + ========== + + k : Positive integer + l : Real number, `\lambda > 0`, the rate + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Erlang, density, cdf, E, variance + >>> from sympy import Symbol, simplify, pprint + + >>> k = Symbol("k", integer=True, positive=True) + >>> l = Symbol("l", positive=True) + >>> z = Symbol("z") + + >>> X = Erlang("x", k, l) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + k k - 1 -l*z + l *z *e + --------------- + Gamma(k) + + >>> C = cdf(X)(z) + >>> pprint(C, use_unicode=False) + /lowergamma(k, l*z) + |------------------ for z > 0 + < Gamma(k) + | + \ 0 otherwise + + + >>> E(X) + k/l + + >>> simplify(variance(X)) + k/l**2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Erlang_distribution + .. [2] https://mathworld.wolfram.com/ErlangDistribution.html + + """ + + return rv(name, GammaDistribution, (k, S.One/l)) + +# ------------------------------------------------------------------------------- +# ExGaussian distribution ----------------------------------------------------- + + +class ExGaussianDistribution(SingleContinuousDistribution): + _argnames = ('mean', 'std', 'rate') + + set = Interval(-oo, oo) + + @staticmethod + def check(mean, std, rate): + _value_check( + std > 0, "Standard deviation of ExGaussian must be positive.") + _value_check(rate > 0, "Rate of ExGaussian must be positive.") + + def pdf(self, x): + mean, std, rate = self.mean, self.std, self.rate + term1 = rate/2 + term2 = exp(rate * (2 * mean + rate * std**2 - 2*x)/2) + term3 = erfc((mean + rate*std**2 - x)/(sqrt(2)*std)) + return term1*term2*term3 + + def _cdf(self, x): + from sympy.stats import cdf + mean, std, rate = self.mean, self.std, self.rate + u = rate*(x - mean) + v = rate*std + GaussianCDF1 = cdf(Normal('x', 0, v))(u) + GaussianCDF2 = cdf(Normal('x', v**2, v))(u) + + return GaussianCDF1 - exp(-u + (v**2/2) + log(GaussianCDF2)) + + def _characteristic_function(self, t): + mean, std, rate = self.mean, self.std, self.rate + term1 = (1 - I*t/rate)**(-1) + term2 = exp(I*mean*t - std**2*t**2/2) + return term1 * term2 + + def _moment_generating_function(self, t): + mean, std, rate = self.mean, self.std, self.rate + term1 = (1 - t/rate)**(-1) + term2 = exp(mean*t + std**2*t**2/2) + return term1*term2 + + +def ExGaussian(name, mean, std, rate): + r""" + Create a continuous random variable with an Exponentially modified + Gaussian (EMG) distribution. + + Explanation + =========== + + The density of the exponentially modified Gaussian distribution is given by + + .. math:: + f(x) := \frac{\lambda}{2}e^{\frac{\lambda}{2}(2\mu+\lambda\sigma^2-2x)} + \text{erfc}(\frac{\mu + \lambda\sigma^2 - x}{\sqrt{2}\sigma}) + + with $x > 0$. Note that the expected value is `1/\lambda`. + + Parameters + ========== + + name : A string giving a name for this distribution + mean : A Real number, the mean of Gaussian component + std : A positive Real number, + :math: `\sigma^2 > 0` the variance of Gaussian component + rate : A positive Real number, + :math: `\lambda > 0` the rate of Exponential component + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import ExGaussian, density, cdf, E + >>> from sympy.stats import variance, skewness + >>> from sympy import Symbol, pprint, simplify + + >>> mean = Symbol("mu") + >>> std = Symbol("sigma", positive=True) + >>> rate = Symbol("lamda", positive=True) + >>> z = Symbol("z") + >>> X = ExGaussian("x", mean, std, rate) + + >>> pprint(density(X)(z), use_unicode=False) + / 2 \ + lamda*\lamda*sigma + 2*mu - 2*z/ + --------------------------------- / ___ / 2 \\ + 2 |\/ 2 *\lamda*sigma + mu - z/| + lamda*e *erfc|-----------------------------| + \ 2*sigma / + ---------------------------------------------------------------------------- + 2 + + >>> cdf(X)(z) + -(erf(sqrt(2)*(-lamda**2*sigma**2 + lamda*(-mu + z))/(2*lamda*sigma))/2 + 1/2)*exp(lamda**2*sigma**2/2 - lamda*(-mu + z)) + erf(sqrt(2)*(-mu + z)/(2*sigma))/2 + 1/2 + + >>> E(X) + (lamda*mu + 1)/lamda + + >>> simplify(variance(X)) + sigma**2 + lamda**(-2) + + >>> simplify(skewness(X)) + 2/(lamda**2*sigma**2 + 1)**(3/2) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Exponentially_modified_Gaussian_distribution + """ + return rv(name, ExGaussianDistribution, (mean, std, rate)) + +#------------------------------------------------------------------------------- +# Exponential distribution ----------------------------------------------------- + + +class ExponentialDistribution(SingleContinuousDistribution): + _argnames = ('rate',) + + set = Interval(0, oo) + + @staticmethod + def check(rate): + _value_check(rate > 0, "Rate must be positive.") + + def pdf(self, x): + return self.rate * exp(-self.rate*x) + + def _cdf(self, x): + return Piecewise( + (S.One - exp(-self.rate*x), x >= 0), + (0, True), + ) + + def _characteristic_function(self, t): + rate = self.rate + return rate / (rate - I*t) + + def _moment_generating_function(self, t): + rate = self.rate + return rate / (rate - t) + + def _quantile(self, p): + return -log(1-p)/self.rate + + +def Exponential(name, rate): + r""" + Create a continuous random variable with an Exponential distribution. + + Explanation + =========== + + The density of the exponential distribution is given by + + .. math:: + f(x) := \lambda \exp(-\lambda x) + + with $x > 0$. Note that the expected value is `1/\lambda`. + + Parameters + ========== + + rate : A positive Real number, `\lambda > 0`, the rate (or inverse scale/inverse mean) + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Exponential, density, cdf, E + >>> from sympy.stats import variance, std, skewness, quantile + >>> from sympy import Symbol + + >>> l = Symbol("lambda", positive=True) + >>> z = Symbol("z") + >>> p = Symbol("p") + >>> X = Exponential("x", l) + + >>> density(X)(z) + lambda*exp(-lambda*z) + + >>> cdf(X)(z) + Piecewise((1 - exp(-lambda*z), z >= 0), (0, True)) + + >>> quantile(X)(p) + -log(1 - p)/lambda + + >>> E(X) + 1/lambda + + >>> variance(X) + lambda**(-2) + + >>> skewness(X) + 2 + + >>> X = Exponential('x', 10) + + >>> density(X)(z) + 10*exp(-10*z) + + >>> E(X) + 1/10 + + >>> std(X) + 1/10 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Exponential_distribution + .. [2] https://mathworld.wolfram.com/ExponentialDistribution.html + + """ + + return rv(name, ExponentialDistribution, (rate, )) + + +# ------------------------------------------------------------------------------- +# Exponential Power distribution ----------------------------------------------------- + +class ExponentialPowerDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'alpha', 'beta') + + set = Interval(-oo, oo) + + @staticmethod + def check(mu, alpha, beta): + _value_check(alpha > 0, "Scale parameter alpha must be positive.") + _value_check(beta > 0, "Shape parameter beta must be positive.") + + def pdf(self, x): + mu, alpha, beta = self.mu, self.alpha, self.beta + num = beta*exp(-(Abs(x - mu)/alpha)**beta) + den = 2*alpha*gamma(1/beta) + return num/den + + def _cdf(self, x): + mu, alpha, beta = self.mu, self.alpha, self.beta + num = lowergamma(1/beta, (Abs(x - mu) / alpha)**beta) + den = 2*gamma(1/beta) + return sign(x - mu)*num/den + S.Half + + +def ExponentialPower(name, mu, alpha, beta): + r""" + Create a Continuous Random Variable with Exponential Power distribution. + This distribution is known also as Generalized Normal + distribution version 1. + + Explanation + =========== + + The density of the Exponential Power distribution is given by + + .. math:: + f(x) := \frac{\beta}{2\alpha\Gamma(\frac{1}{\beta})} + e^{{-(\frac{|x - \mu|}{\alpha})^{\beta}}} + + with :math:`x \in [ - \infty, \infty ]`. + + Parameters + ========== + + mu : Real number + A location. + alpha : Real number,`\alpha > 0` + A scale. + beta : Real number, `\beta > 0` + A shape. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import ExponentialPower, density, cdf + >>> from sympy import Symbol, pprint + >>> z = Symbol("z") + >>> mu = Symbol("mu") + >>> alpha = Symbol("alpha", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> X = ExponentialPower("x", mu, alpha, beta) + >>> pprint(density(X)(z), use_unicode=False) + beta + /|mu - z|\ + -|--------| + \ alpha / + beta*e + --------------------- + / 1 \ + 2*alpha*Gamma|----| + \beta/ + >>> cdf(X)(z) + 1/2 + lowergamma(1/beta, (Abs(mu - z)/alpha)**beta)*sign(-mu + z)/(2*gamma(1/beta)) + + References + ========== + + .. [1] https://reference.wolfram.com/language/ref/ExponentialPowerDistribution.html + .. [2] https://en.wikipedia.org/wiki/Generalized_normal_distribution#Version_1 + + """ + return rv(name, ExponentialPowerDistribution, (mu, alpha, beta)) + + +#------------------------------------------------------------------------------- +# F distribution --------------------------------------------------------------- + + +class FDistributionDistribution(SingleContinuousDistribution): + _argnames = ('d1', 'd2') + + set = Interval(0, oo) + + @staticmethod + def check(d1, d2): + _value_check((d1 > 0, d1.is_integer), + "Degrees of freedom d1 must be positive integer.") + _value_check((d2 > 0, d2.is_integer), + "Degrees of freedom d2 must be positive integer.") + + def pdf(self, x): + d1, d2 = self.d1, self.d2 + return (sqrt((d1*x)**d1*d2**d2 / (d1*x+d2)**(d1+d2)) + / (x * beta_fn(d1/2, d2/2))) + + def _moment_generating_function(self, t): + raise NotImplementedError('The moment generating function for the ' + 'F-distribution does not exist.') + +def FDistribution(name, d1, d2): + r""" + Create a continuous random variable with a F distribution. + + Explanation + =========== + + The density of the F distribution is given by + + .. math:: + f(x) := \frac{\sqrt{\frac{(d_1 x)^{d_1} d_2^{d_2}} + {(d_1 x + d_2)^{d_1 + d_2}}}} + {x \mathrm{B} \left(\frac{d_1}{2}, \frac{d_2}{2}\right)} + + with :math:`x > 0`. + + Parameters + ========== + + d1 : `d_1 > 0`, where `d_1` is the degrees of freedom (`n_1 - 1`) + d2 : `d_2 > 0`, where `d_2` is the degrees of freedom (`n_2 - 1`) + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import FDistribution, density + >>> from sympy import Symbol, pprint + + >>> d1 = Symbol("d1", positive=True) + >>> d2 = Symbol("d2", positive=True) + >>> z = Symbol("z") + + >>> X = FDistribution("x", d1, d2) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + d2 + -- ______________________________ + 2 / d1 -d1 - d2 + d2 *\/ (d1*z) *(d1*z + d2) + -------------------------------------- + /d1 d2\ + z*B|--, --| + \2 2 / + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/F-distribution + .. [2] https://mathworld.wolfram.com/F-Distribution.html + + """ + + return rv(name, FDistributionDistribution, (d1, d2)) + +#------------------------------------------------------------------------------- +# Fisher Z distribution -------------------------------------------------------- + +class FisherZDistribution(SingleContinuousDistribution): + _argnames = ('d1', 'd2') + + set = Interval(-oo, oo) + + @staticmethod + def check(d1, d2): + _value_check(d1 > 0, "Degree of freedom d1 must be positive.") + _value_check(d2 > 0, "Degree of freedom d2 must be positive.") + + def pdf(self, x): + d1, d2 = self.d1, self.d2 + return (2*d1**(d1/2)*d2**(d2/2) / beta_fn(d1/2, d2/2) * + exp(d1*x) / (d1*exp(2*x)+d2)**((d1+d2)/2)) + +def FisherZ(name, d1, d2): + r""" + Create a Continuous Random Variable with an Fisher's Z distribution. + + Explanation + =========== + + The density of the Fisher's Z distribution is given by + + .. math:: + f(x) := \frac{2d_1^{d_1/2} d_2^{d_2/2}} {\mathrm{B}(d_1/2, d_2/2)} + \frac{e^{d_1z}}{\left(d_1e^{2z}+d_2\right)^{\left(d_1+d_2\right)/2}} + + + .. TODO - What is the difference between these degrees of freedom? + + Parameters + ========== + + d1 : `d_1 > 0` + Degree of freedom. + d2 : `d_2 > 0` + Degree of freedom. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import FisherZ, density + >>> from sympy import Symbol, pprint + + >>> d1 = Symbol("d1", positive=True) + >>> d2 = Symbol("d2", positive=True) + >>> z = Symbol("z") + + >>> X = FisherZ("x", d1, d2) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + d1 d2 + d1 d2 - -- - -- + -- -- 2 2 + 2 2 / 2*z \ d1*z + 2*d1 *d2 *\d1*e + d2/ *e + ----------------------------------------- + /d1 d2\ + B|--, --| + \2 2 / + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Fisher%27s_z-distribution + .. [2] https://mathworld.wolfram.com/Fishersz-Distribution.html + + """ + + return rv(name, FisherZDistribution, (d1, d2)) + +#------------------------------------------------------------------------------- +# Frechet distribution --------------------------------------------------------- + +class FrechetDistribution(SingleContinuousDistribution): + _argnames = ('a', 's', 'm') + + set = Interval(0, oo) + + @staticmethod + def check(a, s, m): + _value_check(a > 0, "Shape parameter alpha must be positive.") + _value_check(s > 0, "Scale parameter s must be positive.") + + def __new__(cls, a, s=1, m=0): + a, s, m = list(map(sympify, (a, s, m))) + return Basic.__new__(cls, a, s, m) + + def pdf(self, x): + a, s, m = self.a, self.s, self.m + return a/s * ((x-m)/s)**(-1-a) * exp(-((x-m)/s)**(-a)) + + def _cdf(self, x): + a, s, m = self.a, self.s, self.m + return Piecewise((exp(-((x-m)/s)**(-a)), x >= m), + (S.Zero, True)) + +def Frechet(name, a, s=1, m=0): + r""" + Create a continuous random variable with a Frechet distribution. + + Explanation + =========== + + The density of the Frechet distribution is given by + + .. math:: + f(x) := \frac{\alpha}{s} \left(\frac{x-m}{s}\right)^{-1-\alpha} + e^{-(\frac{x-m}{s})^{-\alpha}} + + with :math:`x \geq m`. + + Parameters + ========== + + a : Real number, :math:`a \in \left(0, \infty\right)` the shape + s : Real number, :math:`s \in \left(0, \infty\right)` the scale + m : Real number, :math:`m \in \left(-\infty, \infty\right)` the minimum + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Frechet, density, cdf + >>> from sympy import Symbol + + >>> a = Symbol("a", positive=True) + >>> s = Symbol("s", positive=True) + >>> m = Symbol("m", real=True) + >>> z = Symbol("z") + + >>> X = Frechet("x", a, s, m) + + >>> density(X)(z) + a*((-m + z)/s)**(-a - 1)*exp(-1/((-m + z)/s)**a)/s + + >>> cdf(X)(z) + Piecewise((exp(-1/((-m + z)/s)**a), m <= z), (0, True)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Fr%C3%A9chet_distribution + + """ + + return rv(name, FrechetDistribution, (a, s, m)) + +#------------------------------------------------------------------------------- +# Gamma distribution ----------------------------------------------------------- + + +class GammaDistribution(SingleContinuousDistribution): + _argnames = ('k', 'theta') + + set = Interval(0, oo) + + @staticmethod + def check(k, theta): + _value_check(k > 0, "k must be positive") + _value_check(theta > 0, "Theta must be positive") + + def pdf(self, x): + k, theta = self.k, self.theta + return x**(k - 1) * exp(-x/theta) / (gamma(k)*theta**k) + + def _cdf(self, x): + k, theta = self.k, self.theta + return Piecewise( + (lowergamma(k, S(x)/theta)/gamma(k), x > 0), + (S.Zero, True)) + + def _characteristic_function(self, t): + return (1 - self.theta*I*t)**(-self.k) + + def _moment_generating_function(self, t): + return (1- self.theta*t)**(-self.k) + + +def Gamma(name, k, theta): + r""" + Create a continuous random variable with a Gamma distribution. + + Explanation + =========== + + The density of the Gamma distribution is given by + + .. math:: + f(x) := \frac{1}{\Gamma(k) \theta^k} x^{k - 1} e^{-\frac{x}{\theta}} + + with :math:`x \in [0,1]`. + + Parameters + ========== + + k : Real number, `k > 0`, a shape + theta : Real number, `\theta > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Gamma, density, cdf, E, variance + >>> from sympy import Symbol, pprint, simplify + + >>> k = Symbol("k", positive=True) + >>> theta = Symbol("theta", positive=True) + >>> z = Symbol("z") + + >>> X = Gamma("x", k, theta) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + -z + ----- + -k k - 1 theta + theta *z *e + --------------------- + Gamma(k) + + >>> C = cdf(X, meijerg=True)(z) + >>> pprint(C, use_unicode=False) + / / z \ + |k*lowergamma|k, -----| + | \ theta/ + <---------------------- for z >= 0 + | Gamma(k + 1) + | + \ 0 otherwise + + >>> E(X) + k*theta + + >>> V = simplify(variance(X)) + >>> pprint(V, use_unicode=False) + 2 + k*theta + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Gamma_distribution + .. [2] https://mathworld.wolfram.com/GammaDistribution.html + + """ + + return rv(name, GammaDistribution, (k, theta)) + +#------------------------------------------------------------------------------- +# Inverse Gamma distribution --------------------------------------------------- + + +class GammaInverseDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b') + + set = Interval(0, oo) + + @staticmethod + def check(a, b): + _value_check(a > 0, "alpha must be positive") + _value_check(b > 0, "beta must be positive") + + def pdf(self, x): + a, b = self.a, self.b + return b**a/gamma(a) * x**(-a-1) * exp(-b/x) + + def _cdf(self, x): + a, b = self.a, self.b + return Piecewise((uppergamma(a,b/x)/gamma(a), x > 0), + (S.Zero, True)) + + def _characteristic_function(self, t): + a, b = self.a, self.b + return 2 * (-I*b*t)**(a/2) * besselk(a, sqrt(-4*I*b*t)) / gamma(a) + + def _moment_generating_function(self, t): + raise NotImplementedError('The moment generating function for the ' + 'gamma inverse distribution does not exist.') + +def GammaInverse(name, a, b): + r""" + Create a continuous random variable with an inverse Gamma distribution. + + Explanation + =========== + + The density of the inverse Gamma distribution is given by + + .. math:: + f(x) := \frac{\beta^\alpha}{\Gamma(\alpha)} x^{-\alpha - 1} + \exp\left(\frac{-\beta}{x}\right) + + with :math:`x > 0`. + + Parameters + ========== + + a : Real number, `a > 0`, a shape + b : Real number, `b > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import GammaInverse, density, cdf + >>> from sympy import Symbol, pprint + + >>> a = Symbol("a", positive=True) + >>> b = Symbol("b", positive=True) + >>> z = Symbol("z") + + >>> X = GammaInverse("x", a, b) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + -b + --- + a -a - 1 z + b *z *e + --------------- + Gamma(a) + + >>> cdf(X)(z) + Piecewise((uppergamma(a, b/z)/gamma(a), z > 0), (0, True)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Inverse-gamma_distribution + + """ + + return rv(name, GammaInverseDistribution, (a, b)) + + +#------------------------------------------------------------------------------- +# Gumbel distribution (Maximum and Minimum) -------------------------------------------------------- + + +class GumbelDistribution(SingleContinuousDistribution): + _argnames = ('beta', 'mu', 'minimum') + + set = Interval(-oo, oo) + + @staticmethod + def check(beta, mu, minimum): + _value_check(beta > 0, "Scale parameter beta must be positive.") + + def pdf(self, x): + beta, mu = self.beta, self.mu + z = (x - mu)/beta + f_max = (1/beta)*exp(-z - exp(-z)) + f_min = (1/beta)*exp(z - exp(z)) + return Piecewise((f_min, self.minimum), (f_max, not self.minimum)) + + def _cdf(self, x): + beta, mu = self.beta, self.mu + z = (x - mu)/beta + F_max = exp(-exp(-z)) + F_min = 1 - exp(-exp(z)) + return Piecewise((F_min, self.minimum), (F_max, not self.minimum)) + + def _characteristic_function(self, t): + cf_max = gamma(1 - I*self.beta*t) * exp(I*self.mu*t) + cf_min = gamma(1 + I*self.beta*t) * exp(I*self.mu*t) + return Piecewise((cf_min, self.minimum), (cf_max, not self.minimum)) + + def _moment_generating_function(self, t): + mgf_max = gamma(1 - self.beta*t) * exp(self.mu*t) + mgf_min = gamma(1 + self.beta*t) * exp(self.mu*t) + return Piecewise((mgf_min, self.minimum), (mgf_max, not self.minimum)) + +def Gumbel(name, beta, mu, minimum=False): + r""" + Create a Continuous Random Variable with Gumbel distribution. + + Explanation + =========== + + The density of the Gumbel distribution is given by + + For Maximum + + .. math:: + f(x) := \dfrac{1}{\beta} \exp \left( -\dfrac{x-\mu}{\beta} + - \exp \left( -\dfrac{x - \mu}{\beta} \right) \right) + + with :math:`x \in [ - \infty, \infty ]`. + + For Minimum + + .. math:: + f(x) := \frac{e^{- e^{\frac{- \mu + x}{\beta}} + \frac{- \mu + x}{\beta}}}{\beta} + + with :math:`x \in [ - \infty, \infty ]`. + + Parameters + ========== + + mu : Real number, `\mu`, a location + beta : Real number, `\beta > 0`, a scale + minimum : Boolean, by default ``False``, set to ``True`` for enabling minimum distribution + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Gumbel, density, cdf + >>> from sympy import Symbol + >>> x = Symbol("x") + >>> mu = Symbol("mu") + >>> beta = Symbol("beta", positive=True) + >>> X = Gumbel("x", beta, mu) + >>> density(X)(x) + exp(-exp(-(-mu + x)/beta) - (-mu + x)/beta)/beta + >>> cdf(X)(x) + exp(-exp(-(-mu + x)/beta)) + + References + ========== + + .. [1] https://mathworld.wolfram.com/GumbelDistribution.html + .. [2] https://en.wikipedia.org/wiki/Gumbel_distribution + .. [3] https://web.archive.org/web/20200628222206/http://www.mathwave.com/help/easyfit/html/analyses/distributions/gumbel_max.html + .. [4] https://web.archive.org/web/20200628222212/http://www.mathwave.com/help/easyfit/html/analyses/distributions/gumbel_min.html + + """ + return rv(name, GumbelDistribution, (beta, mu, minimum)) + +#------------------------------------------------------------------------------- +# Gompertz distribution -------------------------------------------------------- + +class GompertzDistribution(SingleContinuousDistribution): + _argnames = ('b', 'eta') + + set = Interval(0, oo) + + @staticmethod + def check(b, eta): + _value_check(b > 0, "b must be positive") + _value_check(eta > 0, "eta must be positive") + + def pdf(self, x): + eta, b = self.eta, self.b + return b*eta*exp(b*x)*exp(eta)*exp(-eta*exp(b*x)) + + def _cdf(self, x): + eta, b = self.eta, self.b + return 1 - exp(eta)*exp(-eta*exp(b*x)) + + def _moment_generating_function(self, t): + eta, b = self.eta, self.b + return eta * exp(eta) * expint(t/b, eta) + +def Gompertz(name, b, eta): + r""" + Create a Continuous Random Variable with Gompertz distribution. + + Explanation + =========== + + The density of the Gompertz distribution is given by + + .. math:: + f(x) := b \eta e^{b x} e^{\eta} \exp \left(-\eta e^{bx} \right) + + with :math:`x \in [0, \infty)`. + + Parameters + ========== + + b : Real number, `b > 0`, a scale + eta : Real number, `\eta > 0`, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Gompertz, density + >>> from sympy import Symbol + + >>> b = Symbol("b", positive=True) + >>> eta = Symbol("eta", positive=True) + >>> z = Symbol("z") + + >>> X = Gompertz("x", b, eta) + + >>> density(X)(z) + b*eta*exp(eta)*exp(b*z)*exp(-eta*exp(b*z)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Gompertz_distribution + + """ + return rv(name, GompertzDistribution, (b, eta)) + +#------------------------------------------------------------------------------- +# Kumaraswamy distribution ----------------------------------------------------- + + +class KumaraswamyDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b') + + set = Interval(0, oo) + + @staticmethod + def check(a, b): + _value_check(a > 0, "a must be positive") + _value_check(b > 0, "b must be positive") + + def pdf(self, x): + a, b = self.a, self.b + return a * b * x**(a-1) * (1-x**a)**(b-1) + + def _cdf(self, x): + a, b = self.a, self.b + return Piecewise( + (S.Zero, x < S.Zero), + (1 - (1 - x**a)**b, x <= S.One), + (S.One, True)) + +def Kumaraswamy(name, a, b): + r""" + Create a Continuous Random Variable with a Kumaraswamy distribution. + + Explanation + =========== + + The density of the Kumaraswamy distribution is given by + + .. math:: + f(x) := a b x^{a-1} (1-x^a)^{b-1} + + with :math:`x \in [0,1]`. + + Parameters + ========== + + a : Real number, `a > 0`, a shape + b : Real number, `b > 0`, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Kumaraswamy, density, cdf + >>> from sympy import Symbol, pprint + + >>> a = Symbol("a", positive=True) + >>> b = Symbol("b", positive=True) + >>> z = Symbol("z") + + >>> X = Kumaraswamy("x", a, b) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + b - 1 + a - 1 / a\ + a*b*z *\1 - z / + + >>> cdf(X)(z) + Piecewise((0, z < 0), (1 - (1 - z**a)**b, z <= 1), (1, True)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Kumaraswamy_distribution + + """ + + return rv(name, KumaraswamyDistribution, (a, b)) + +#------------------------------------------------------------------------------- +# Laplace distribution --------------------------------------------------------- + + +class LaplaceDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'b') + + set = Interval(-oo, oo) + + @staticmethod + def check(mu, b): + _value_check(b > 0, "Scale parameter b must be positive.") + _value_check(mu.is_real, "Location parameter mu should be real") + + def pdf(self, x): + mu, b = self.mu, self.b + return 1/(2*b)*exp(-Abs(x - mu)/b) + + def _cdf(self, x): + mu, b = self.mu, self.b + return Piecewise( + (S.Half*exp((x - mu)/b), x < mu), + (S.One - S.Half*exp(-(x - mu)/b), x >= mu) + ) + + def _characteristic_function(self, t): + return exp(self.mu*I*t) / (1 + self.b**2*t**2) + + def _moment_generating_function(self, t): + return exp(self.mu*t) / (1 - self.b**2*t**2) + +def Laplace(name, mu, b): + r""" + Create a continuous random variable with a Laplace distribution. + + Explanation + =========== + + The density of the Laplace distribution is given by + + .. math:: + f(x) := \frac{1}{2 b} \exp \left(-\frac{|x-\mu|}b \right) + + Parameters + ========== + + mu : Real number or a list/matrix, the location (mean) or the + location vector + b : Real number or a positive definite matrix, representing a scale + or the covariance matrix. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Laplace, density, cdf + >>> from sympy import Symbol, pprint + + >>> mu = Symbol("mu") + >>> b = Symbol("b", positive=True) + >>> z = Symbol("z") + + >>> X = Laplace("x", mu, b) + + >>> density(X)(z) + exp(-Abs(mu - z)/b)/(2*b) + + >>> cdf(X)(z) + Piecewise((exp((-mu + z)/b)/2, mu > z), (1 - exp((mu - z)/b)/2, True)) + + >>> L = Laplace('L', [1, 2], [[1, 0], [0, 1]]) + >>> pprint(density(L)(1, 2), use_unicode=False) + 5 / ____\ + e *besselk\0, \/ 35 / + --------------------- + pi + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Laplace_distribution + .. [2] https://mathworld.wolfram.com/LaplaceDistribution.html + + """ + + if isinstance(mu, (list, MatrixBase)) and\ + isinstance(b, (list, MatrixBase)): + from sympy.stats.joint_rv_types import MultivariateLaplace + return MultivariateLaplace(name, mu, b) + + return rv(name, LaplaceDistribution, (mu, b)) + +#------------------------------------------------------------------------------- +# Levy distribution --------------------------------------------------------- + + +class LevyDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'c') + + @property + def set(self): + return Interval(self.mu, oo) + + @staticmethod + def check(mu, c): + _value_check(c > 0, "c (scale parameter) must be positive") + _value_check(mu.is_real, "mu (location parameter) must be real") + + def pdf(self, x): + mu, c = self.mu, self.c + return sqrt(c/(2*pi))*exp(-c/(2*(x - mu)))/((x - mu)**(S.One + S.Half)) + + def _cdf(self, x): + mu, c = self.mu, self.c + return erfc(sqrt(c/(2*(x - mu)))) + + def _characteristic_function(self, t): + mu, c = self.mu, self.c + return exp(I * mu * t - sqrt(-2 * I * c * t)) + + def _moment_generating_function(self, t): + raise NotImplementedError('The moment generating function of Levy distribution does not exist.') + +def Levy(name, mu, c): + r""" + Create a continuous random variable with a Levy distribution. + + The density of the Levy distribution is given by + + .. math:: + f(x) := \sqrt(\frac{c}{2 \pi}) \frac{\exp -\frac{c}{2 (x - \mu)}}{(x - \mu)^{3/2}} + + Parameters + ========== + + mu : Real number + The location parameter. + c : Real number, `c > 0` + A scale parameter. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Levy, density, cdf + >>> from sympy import Symbol + + >>> mu = Symbol("mu", real=True) + >>> c = Symbol("c", positive=True) + >>> z = Symbol("z") + + >>> X = Levy("x", mu, c) + + >>> density(X)(z) + sqrt(2)*sqrt(c)*exp(-c/(-2*mu + 2*z))/(2*sqrt(pi)*(-mu + z)**(3/2)) + + >>> cdf(X)(z) + erfc(sqrt(c)*sqrt(1/(-2*mu + 2*z))) + + References + ========== + .. [1] https://en.wikipedia.org/wiki/L%C3%A9vy_distribution + .. [2] https://mathworld.wolfram.com/LevyDistribution.html + """ + + return rv(name, LevyDistribution, (mu, c)) + +#------------------------------------------------------------------------------- +# Log-Cauchy distribution -------------------------------------------------------- + + +class LogCauchyDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'sigma') + + set = Interval.open(0, oo) + + @staticmethod + def check(mu, sigma): + _value_check((sigma > 0) != False, "Scale parameter Gamma must be positive.") + _value_check(mu.is_real != False, "Location parameter must be real.") + + def pdf(self, x): + mu, sigma = self.mu, self.sigma + return 1/(x*pi)*(sigma/((log(x) - mu)**2 + sigma**2)) + + def _cdf(self, x): + mu, sigma = self.mu, self.sigma + return (1/pi)*atan((log(x) - mu)/sigma) + S.Half + + def _characteristic_function(self, t): + raise NotImplementedError("The characteristic function for the " + "Log-Cauchy distribution does not exist.") + + def _moment_generating_function(self, t): + raise NotImplementedError("The moment generating function for the " + "Log-Cauchy distribution does not exist.") + +def LogCauchy(name, mu, sigma): + r""" + Create a continuous random variable with a Log-Cauchy distribution. + The density of the Log-Cauchy distribution is given by + + .. math:: + f(x) := \frac{1}{\pi x} \frac{\sigma}{(log(x)-\mu^2) + \sigma^2} + + Parameters + ========== + + mu : Real number, the location + + sigma : Real number, `\sigma > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import LogCauchy, density, cdf + >>> from sympy import Symbol, S + + >>> mu = 2 + >>> sigma = S.One / 5 + >>> z = Symbol("z") + + >>> X = LogCauchy("x", mu, sigma) + + >>> density(X)(z) + 1/(5*pi*z*((log(z) - 2)**2 + 1/25)) + + >>> cdf(X)(z) + atan(5*log(z) - 10)/pi + 1/2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Log-Cauchy_distribution + """ + + return rv(name, LogCauchyDistribution, (mu, sigma)) + + +#------------------------------------------------------------------------------- +# Logistic distribution -------------------------------------------------------- + + +class LogisticDistribution(SingleContinuousDistribution): + _argnames = ('mu', 's') + + set = Interval(-oo, oo) + + @staticmethod + def check(mu, s): + _value_check(s > 0, "Scale parameter s must be positive.") + + def pdf(self, x): + mu, s = self.mu, self.s + return exp(-(x - mu)/s)/(s*(1 + exp(-(x - mu)/s))**2) + + def _cdf(self, x): + mu, s = self.mu, self.s + return S.One/(1 + exp(-(x - mu)/s)) + + def _characteristic_function(self, t): + return Piecewise((exp(I*t*self.mu) * pi*self.s*t / sinh(pi*self.s*t), Ne(t, 0)), (S.One, True)) + + def _moment_generating_function(self, t): + return exp(self.mu*t) * beta_fn(1 - self.s*t, 1 + self.s*t) + + def _quantile(self, p): + return self.mu - self.s*log(-S.One + S.One/p) + +def Logistic(name, mu, s): + r""" + Create a continuous random variable with a logistic distribution. + + Explanation + =========== + + The density of the logistic distribution is given by + + .. math:: + f(x) := \frac{e^{-(x-\mu)/s}} {s\left(1+e^{-(x-\mu)/s}\right)^2} + + Parameters + ========== + + mu : Real number, the location (mean) + s : Real number, `s > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Logistic, density, cdf + >>> from sympy import Symbol + + >>> mu = Symbol("mu", real=True) + >>> s = Symbol("s", positive=True) + >>> z = Symbol("z") + + >>> X = Logistic("x", mu, s) + + >>> density(X)(z) + exp((mu - z)/s)/(s*(exp((mu - z)/s) + 1)**2) + + >>> cdf(X)(z) + 1/(exp((mu - z)/s) + 1) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Logistic_distribution + .. [2] https://mathworld.wolfram.com/LogisticDistribution.html + + """ + + return rv(name, LogisticDistribution, (mu, s)) + +#------------------------------------------------------------------------------- +# Log-logistic distribution -------------------------------------------------------- + + +class LogLogisticDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'beta') + + set = Interval(0, oo) + + @staticmethod + def check(alpha, beta): + _value_check(alpha > 0, "Scale parameter Alpha must be positive.") + _value_check(beta > 0, "Shape parameter Beta must be positive.") + + def pdf(self, x): + a, b = self.alpha, self.beta + return ((b/a)*(x/a)**(b - 1))/(1 + (x/a)**b)**2 + + def _cdf(self, x): + a, b = self.alpha, self.beta + return 1/(1 + (x/a)**(-b)) + + def _quantile(self, p): + a, b = self.alpha, self.beta + return a*((p/(1 - p))**(1/b)) + + def expectation(self, expr, var, **kwargs): + a, b = self.args + return Piecewise((S.NaN, b <= 1), (pi*a/(b*sin(pi/b)), True)) + +def LogLogistic(name, alpha, beta): + r""" + Create a continuous random variable with a log-logistic distribution. + The distribution is unimodal when ``beta > 1``. + + Explanation + =========== + + The density of the log-logistic distribution is given by + + .. math:: + f(x) := \frac{(\frac{\beta}{\alpha})(\frac{x}{\alpha})^{\beta - 1}} + {(1 + (\frac{x}{\alpha})^{\beta})^2} + + Parameters + ========== + + alpha : Real number, `\alpha > 0`, scale parameter and median of distribution + beta : Real number, `\beta > 0`, a shape parameter + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import LogLogistic, density, cdf, quantile + >>> from sympy import Symbol, pprint + + >>> alpha = Symbol("alpha", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> p = Symbol("p") + >>> z = Symbol("z", positive=True) + + >>> X = LogLogistic("x", alpha, beta) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + beta - 1 + / z \ + beta*|-----| + \alpha/ + ------------------------ + 2 + / beta \ + |/ z \ | + alpha*||-----| + 1| + \\alpha/ / + + >>> cdf(X)(z) + 1/(1 + (z/alpha)**(-beta)) + + >>> quantile(X)(p) + alpha*(p/(1 - p))**(1/beta) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Log-logistic_distribution + + """ + + return rv(name, LogLogisticDistribution, (alpha, beta)) + +#------------------------------------------------------------------------------- +#Logit-Normal distribution------------------------------------------------------ + +class LogitNormalDistribution(SingleContinuousDistribution): + _argnames = ('mu', 's') + set = Interval.open(0, 1) + + @staticmethod + def check(mu, s): + _value_check((s ** 2).is_real is not False and s ** 2 > 0, "Squared scale parameter s must be positive.") + _value_check(mu.is_real is not False, "Location parameter must be real") + + def _logit(self, x): + return log(x / (1 - x)) + + def pdf(self, x): + mu, s = self.mu, self.s + return exp(-(self._logit(x) - mu)**2/(2*s**2))*(S.One/sqrt(2*pi*(s**2)))*(1/(x*(1 - x))) + + def _cdf(self, x): + mu, s = self.mu, self.s + return (S.One/2)*(1 + erf((self._logit(x) - mu)/(sqrt(2*s**2)))) + + +def LogitNormal(name, mu, s): + r""" + Create a continuous random variable with a Logit-Normal distribution. + + The density of the logistic distribution is given by + + .. math:: + f(x) := \frac{1}{s \sqrt{2 \pi}} \frac{1}{x(1 - x)} e^{- \frac{(logit(x) - \mu)^2}{s^2}} + where logit(x) = \log(\frac{x}{1 - x}) + Parameters + ========== + + mu : Real number, the location (mean) + s : Real number, `s > 0`, a scale + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import LogitNormal, density, cdf + >>> from sympy import Symbol,pprint + + >>> mu = Symbol("mu", real=True) + >>> s = Symbol("s", positive=True) + >>> z = Symbol("z") + >>> X = LogitNormal("x",mu,s) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + 2 + / / z \\ + -|-mu + log|-----|| + \ \1 - z// + --------------------- + 2 + ___ 2*s + \/ 2 *e + ---------------------------- + ____ + 2*\/ pi *s*z*(1 - z) + + >>> density(X)(z) + sqrt(2)*exp(-(-mu + log(z/(1 - z)))**2/(2*s**2))/(2*sqrt(pi)*s*z*(1 - z)) + + >>> cdf(X)(z) + erf(sqrt(2)*(-mu + log(z/(1 - z)))/(2*s))/2 + 1/2 + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Logit-normal_distribution + + """ + + return rv(name, LogitNormalDistribution, (mu, s)) + +#------------------------------------------------------------------------------- +# Log Normal distribution ------------------------------------------------------ + + +class LogNormalDistribution(SingleContinuousDistribution): + _argnames = ('mean', 'std') + + set = Interval(0, oo) + + @staticmethod + def check(mean, std): + _value_check(std > 0, "Parameter std must be positive.") + + def pdf(self, x): + mean, std = self.mean, self.std + return exp(-(log(x) - mean)**2 / (2*std**2)) / (x*sqrt(2*pi)*std) + + def _cdf(self, x): + mean, std = self.mean, self.std + return Piecewise( + (S.Half + S.Half*erf((log(x) - mean)/sqrt(2)/std), x > 0), + (S.Zero, True) + ) + + def _moment_generating_function(self, t): + raise NotImplementedError('Moment generating function of the log-normal distribution is not defined.') + + +def LogNormal(name, mean, std): + r""" + Create a continuous random variable with a log-normal distribution. + + Explanation + =========== + + The density of the log-normal distribution is given by + + .. math:: + f(x) := \frac{1}{x\sqrt{2\pi\sigma^2}} + e^{-\frac{\left(\ln x-\mu\right)^2}{2\sigma^2}} + + with :math:`x \geq 0`. + + Parameters + ========== + + mu : Real number + The log-scale. + sigma : Real number + A shape. ($\sigma^2 > 0$) + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import LogNormal, density + >>> from sympy import Symbol, pprint + + >>> mu = Symbol("mu", real=True) + >>> sigma = Symbol("sigma", positive=True) + >>> z = Symbol("z") + + >>> X = LogNormal("x", mu, sigma) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + 2 + -(-mu + log(z)) + ----------------- + 2 + ___ 2*sigma + \/ 2 *e + ------------------------ + ____ + 2*\/ pi *sigma*z + + + >>> X = LogNormal('x', 0, 1) # Mean 0, standard deviation 1 + + >>> density(X)(z) + sqrt(2)*exp(-log(z)**2/2)/(2*sqrt(pi)*z) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Lognormal + .. [2] https://mathworld.wolfram.com/LogNormalDistribution.html + + """ + + return rv(name, LogNormalDistribution, (mean, std)) + +#------------------------------------------------------------------------------- +# Lomax Distribution ----------------------------------------------------------- + +class LomaxDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'lamda',) + set = Interval(0, oo) + + @staticmethod + def check(alpha, lamda): + _value_check(alpha.is_real, "Shape parameter should be real.") + _value_check(lamda.is_real, "Scale parameter should be real.") + _value_check(alpha.is_positive, "Shape parameter should be positive.") + _value_check(lamda.is_positive, "Scale parameter should be positive.") + + def pdf(self, x): + lamba, alpha = self.lamda, self.alpha + return (alpha/lamba) * (S.One + x/lamba)**(-alpha-1) + +def Lomax(name, alpha, lamda): + r""" + Create a continuous random variable with a Lomax distribution. + + Explanation + =========== + + The density of the Lomax distribution is given by + + .. math:: + f(x) := \frac{\alpha}{\lambda}\left[1+\frac{x}{\lambda}\right]^{-(\alpha+1)} + + Parameters + ========== + + alpha : Real Number, `\alpha > 0` + Shape parameter + lamda : Real Number, `\lambda > 0` + Scale parameter + + Examples + ======== + + >>> from sympy.stats import Lomax, density, cdf, E + >>> from sympy import symbols + >>> a, l = symbols('a, l', positive=True) + >>> X = Lomax('X', a, l) + >>> x = symbols('x') + >>> density(X)(x) + a*(1 + x/l)**(-a - 1)/l + >>> cdf(X)(x) + Piecewise((1 - 1/(1 + x/l)**a, x >= 0), (0, True)) + >>> a = 2 + >>> X = Lomax('X', a, l) + >>> E(X) + l + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Lomax_distribution + + """ + return rv(name, LomaxDistribution, (alpha, lamda)) + +#------------------------------------------------------------------------------- +# Maxwell distribution --------------------------------------------------------- + + +class MaxwellDistribution(SingleContinuousDistribution): + _argnames = ('a',) + + set = Interval(0, oo) + + @staticmethod + def check(a): + _value_check(a > 0, "Parameter a must be positive.") + + def pdf(self, x): + a = self.a + return sqrt(2/pi)*x**2*exp(-x**2/(2*a**2))/a**3 + + def _cdf(self, x): + a = self.a + return erf(sqrt(2)*x/(2*a)) - sqrt(2)*x*exp(-x**2/(2*a**2))/(sqrt(pi)*a) + +def Maxwell(name, a): + r""" + Create a continuous random variable with a Maxwell distribution. + + Explanation + =========== + + The density of the Maxwell distribution is given by + + .. math:: + f(x) := \sqrt{\frac{2}{\pi}} \frac{x^2 e^{-x^2/(2a^2)}}{a^3} + + with :math:`x \geq 0`. + + .. TODO - what does the parameter mean? + + Parameters + ========== + + a : Real number, `a > 0` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Maxwell, density, E, variance + >>> from sympy import Symbol, simplify + + >>> a = Symbol("a", positive=True) + >>> z = Symbol("z") + + >>> X = Maxwell("x", a) + + >>> density(X)(z) + sqrt(2)*z**2*exp(-z**2/(2*a**2))/(sqrt(pi)*a**3) + + >>> E(X) + 2*sqrt(2)*a/sqrt(pi) + + >>> simplify(variance(X)) + a**2*(-8 + 3*pi)/pi + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Maxwell_distribution + .. [2] https://mathworld.wolfram.com/MaxwellDistribution.html + + """ + + return rv(name, MaxwellDistribution, (a, )) + +#------------------------------------------------------------------------------- +# Moyal Distribution ----------------------------------------------------------- +class MoyalDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'sigma') + + @staticmethod + def check(mu, sigma): + _value_check(mu.is_real, "Location parameter must be real.") + _value_check(sigma.is_real and sigma > 0, "Scale parameter must be real\ + and positive.") + + def pdf(self, x): + mu, sigma = self.mu, self.sigma + num = exp(-(exp(-(x - mu)/sigma) + (x - mu)/(sigma))/2) + den = (sqrt(2*pi) * sigma) + return num/den + + def _characteristic_function(self, t): + mu, sigma = self.mu, self.sigma + term1 = exp(I*t*mu) + term2 = (2**(-I*sigma*t) * gamma(Rational(1, 2) - I*t*sigma)) + return (term1 * term2)/sqrt(pi) + + def _moment_generating_function(self, t): + mu, sigma = self.mu, self.sigma + term1 = exp(t*mu) + term2 = (2**(-1*sigma*t) * gamma(Rational(1, 2) - t*sigma)) + return (term1 * term2)/sqrt(pi) + +def Moyal(name, mu, sigma): + r""" + Create a continuous random variable with a Moyal distribution. + + Explanation + =========== + + The density of the Moyal distribution is given by + + .. math:: + f(x) := \frac{\exp-\frac{1}{2}\exp-\frac{x-\mu}{\sigma}-\frac{x-\mu}{2\sigma}}{\sqrt{2\pi}\sigma} + + with :math:`x \in \mathbb{R}`. + + Parameters + ========== + + mu : Real number + Location parameter + sigma : Real positive number + Scale parameter + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Moyal, density, cdf + >>> from sympy import Symbol, simplify + >>> mu = Symbol("mu", real=True) + >>> sigma = Symbol("sigma", positive=True, real=True) + >>> z = Symbol("z") + >>> X = Moyal("x", mu, sigma) + >>> density(X)(z) + sqrt(2)*exp(-exp((mu - z)/sigma)/2 - (-mu + z)/(2*sigma))/(2*sqrt(pi)*sigma) + >>> simplify(cdf(X)(z)) + 1 - erf(sqrt(2)*exp((mu - z)/(2*sigma))/2) + + References + ========== + + .. [1] https://reference.wolfram.com/language/ref/MoyalDistribution.html + .. [2] https://www.stat.rice.edu/~dobelman/textfiles/DistributionsHandbook.pdf + + """ + + return rv(name, MoyalDistribution, (mu, sigma)) + +#------------------------------------------------------------------------------- +# Nakagami distribution -------------------------------------------------------- + + +class NakagamiDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'omega') + + set = Interval(0, oo) + + @staticmethod + def check(mu, omega): + _value_check(mu >= S.Half, "Shape parameter mu must be greater than equal to 1/2.") + _value_check(omega > 0, "Spread parameter omega must be positive.") + + def pdf(self, x): + mu, omega = self.mu, self.omega + return 2*mu**mu/(gamma(mu)*omega**mu)*x**(2*mu - 1)*exp(-mu/omega*x**2) + + def _cdf(self, x): + mu, omega = self.mu, self.omega + return Piecewise( + (lowergamma(mu, (mu/omega)*x**2)/gamma(mu), x > 0), + (S.Zero, True)) + +def Nakagami(name, mu, omega): + r""" + Create a continuous random variable with a Nakagami distribution. + + Explanation + =========== + + The density of the Nakagami distribution is given by + + .. math:: + f(x) := \frac{2\mu^\mu}{\Gamma(\mu)\omega^\mu} x^{2\mu-1} + \exp\left(-\frac{\mu}{\omega}x^2 \right) + + with :math:`x > 0`. + + Parameters + ========== + + mu : Real number, `\mu \geq \frac{1}{2}`, a shape + omega : Real number, `\omega > 0`, the spread + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Nakagami, density, E, variance, cdf + >>> from sympy import Symbol, simplify, pprint + + >>> mu = Symbol("mu", positive=True) + >>> omega = Symbol("omega", positive=True) + >>> z = Symbol("z") + + >>> X = Nakagami("x", mu, omega) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + 2 + -mu*z + ------- + mu -mu 2*mu - 1 omega + 2*mu *omega *z *e + ---------------------------------- + Gamma(mu) + + >>> simplify(E(X)) + sqrt(mu)*sqrt(omega)*gamma(mu + 1/2)/gamma(mu + 1) + + >>> V = simplify(variance(X)) + >>> pprint(V, use_unicode=False) + 2 + omega*Gamma (mu + 1/2) + omega - ----------------------- + Gamma(mu)*Gamma(mu + 1) + + >>> cdf(X)(z) + Piecewise((lowergamma(mu, mu*z**2/omega)/gamma(mu), z > 0), + (0, True)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Nakagami_distribution + + """ + + return rv(name, NakagamiDistribution, (mu, omega)) + +#------------------------------------------------------------------------------- +# Normal distribution ---------------------------------------------------------- + + +class NormalDistribution(SingleContinuousDistribution): + _argnames = ('mean', 'std') + + @staticmethod + def check(mean, std): + _value_check(std > 0, "Standard deviation must be positive") + + def pdf(self, x): + return exp(-(x - self.mean)**2 / (2*self.std**2)) / (sqrt(2*pi)*self.std) + + def _cdf(self, x): + mean, std = self.mean, self.std + return erf(sqrt(2)*(-mean + x)/(2*std))/2 + S.Half + + def _characteristic_function(self, t): + mean, std = self.mean, self.std + return exp(I*mean*t - std**2*t**2/2) + + def _moment_generating_function(self, t): + mean, std = self.mean, self.std + return exp(mean*t + std**2*t**2/2) + + def _quantile(self, p): + mean, std = self.mean, self.std + return mean + std*sqrt(2)*erfinv(2*p - 1) + + +def Normal(name, mean, std): + r""" + Create a continuous random variable with a Normal distribution. + + Explanation + =========== + + The density of the Normal distribution is given by + + .. math:: + f(x) := \frac{1}{\sigma\sqrt{2\pi}} e^{ -\frac{(x-\mu)^2}{2\sigma^2} } + + Parameters + ========== + + mu : Real number or a list representing the mean or the mean vector + sigma : Real number or a positive definite square matrix, + :math:`\sigma^2 > 0`, the variance + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Normal, density, E, std, cdf, skewness, quantile, marginal_distribution + >>> from sympy import Symbol, simplify, pprint + + >>> mu = Symbol("mu") + >>> sigma = Symbol("sigma", positive=True) + >>> z = Symbol("z") + >>> y = Symbol("y") + >>> p = Symbol("p") + >>> X = Normal("x", mu, sigma) + + >>> density(X)(z) + sqrt(2)*exp(-(-mu + z)**2/(2*sigma**2))/(2*sqrt(pi)*sigma) + + >>> C = simplify(cdf(X))(z) # it needs a little more help... + >>> pprint(C, use_unicode=False) + / ___ \ + |\/ 2 *(-mu + z)| + erf|---------------| + \ 2*sigma / 1 + -------------------- + - + 2 2 + + >>> quantile(X)(p) + mu + sqrt(2)*sigma*erfinv(2*p - 1) + + >>> simplify(skewness(X)) + 0 + + >>> X = Normal("x", 0, 1) # Mean 0, standard deviation 1 + >>> density(X)(z) + sqrt(2)*exp(-z**2/2)/(2*sqrt(pi)) + + >>> E(2*X + 1) + 1 + + >>> simplify(std(2*X + 1)) + 2 + + >>> m = Normal('X', [1, 2], [[2, 1], [1, 2]]) + >>> pprint(density(m)(y, z), use_unicode=False) + 2 2 + y y*z z + - -- + --- - -- + z - 1 + ___ 3 3 3 + \/ 3 *e + ------------------------------ + 6*pi + + >>> marginal_distribution(m, m[0])(1) + 1/(2*sqrt(pi)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Normal_distribution + .. [2] https://mathworld.wolfram.com/NormalDistributionFunction.html + + """ + + if isinstance(mean, list) or getattr(mean, 'is_Matrix', False) and\ + isinstance(std, list) or getattr(std, 'is_Matrix', False): + from sympy.stats.joint_rv_types import MultivariateNormal + return MultivariateNormal(name, mean, std) + return rv(name, NormalDistribution, (mean, std)) + + +#------------------------------------------------------------------------------- +# Inverse Gaussian distribution ---------------------------------------------------------- + + +class GaussianInverseDistribution(SingleContinuousDistribution): + _argnames = ('mean', 'shape') + + @property + def set(self): + return Interval(0, oo) + + @staticmethod + def check(mean, shape): + _value_check(shape > 0, "Shape parameter must be positive") + _value_check(mean > 0, "Mean must be positive") + + def pdf(self, x): + mu, s = self.mean, self.shape + return exp(-s*(x - mu)**2 / (2*x*mu**2)) * sqrt(s/(2*pi*x**3)) + + def _cdf(self, x): + from sympy.stats import cdf + mu, s = self.mean, self.shape + stdNormalcdf = cdf(Normal('x', 0, 1)) + + first_term = stdNormalcdf(sqrt(s/x) * ((x/mu) - S.One)) + second_term = exp(2*s/mu) * stdNormalcdf(-sqrt(s/x)*(x/mu + S.One)) + + return first_term + second_term + + def _characteristic_function(self, t): + mu, s = self.mean, self.shape + return exp((s/mu)*(1 - sqrt(1 - (2*mu**2*I*t)/s))) + + def _moment_generating_function(self, t): + mu, s = self.mean, self.shape + return exp((s/mu)*(1 - sqrt(1 - (2*mu**2*t)/s))) + + +def GaussianInverse(name, mean, shape): + r""" + Create a continuous random variable with an Inverse Gaussian distribution. + Inverse Gaussian distribution is also known as Wald distribution. + + Explanation + =========== + + The density of the Inverse Gaussian distribution is given by + + .. math:: + f(x) := \sqrt{\frac{\lambda}{2\pi x^3}} e^{-\frac{\lambda(x-\mu)^2}{2x\mu^2}} + + Parameters + ========== + + mu : + Positive number representing the mean. + lambda : + Positive number representing the shape parameter. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import GaussianInverse, density, E, std, skewness + >>> from sympy import Symbol, pprint + + >>> mu = Symbol("mu", positive=True) + >>> lamda = Symbol("lambda", positive=True) + >>> z = Symbol("z", positive=True) + >>> X = GaussianInverse("x", mu, lamda) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + 2 + -lambda*(-mu + z) + ------------------- + 2 + ___ ________ 2*mu *z + \/ 2 *\/ lambda *e + ------------------------------------- + ____ 3/2 + 2*\/ pi *z + + >>> E(X) + mu + + >>> std(X).expand() + mu**(3/2)/sqrt(lambda) + + >>> skewness(X).expand() + 3*sqrt(mu)/sqrt(lambda) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Inverse_Gaussian_distribution + .. [2] https://mathworld.wolfram.com/InverseGaussianDistribution.html + + """ + + return rv(name, GaussianInverseDistribution, (mean, shape)) + +Wald = GaussianInverse + +#------------------------------------------------------------------------------- +# Pareto distribution ---------------------------------------------------------- + + +class ParetoDistribution(SingleContinuousDistribution): + _argnames = ('xm', 'alpha') + + @property + def set(self): + return Interval(self.xm, oo) + + @staticmethod + def check(xm, alpha): + _value_check(xm > 0, "Xm must be positive") + _value_check(alpha > 0, "Alpha must be positive") + + def pdf(self, x): + xm, alpha = self.xm, self.alpha + return alpha * xm**alpha / x**(alpha + 1) + + def _cdf(self, x): + xm, alpha = self.xm, self.alpha + return Piecewise( + (S.One - xm**alpha/x**alpha, x>=xm), + (0, True), + ) + + def _moment_generating_function(self, t): + xm, alpha = self.xm, self.alpha + return alpha * (-xm*t)**alpha * uppergamma(-alpha, -xm*t) + + def _characteristic_function(self, t): + xm, alpha = self.xm, self.alpha + return alpha * (-I * xm * t) ** alpha * uppergamma(-alpha, -I * xm * t) + + +def Pareto(name, xm, alpha): + r""" + Create a continuous random variable with the Pareto distribution. + + Explanation + =========== + + The density of the Pareto distribution is given by + + .. math:: + f(x) := \frac{\alpha\,x_m^\alpha}{x^{\alpha+1}} + + with :math:`x \in [x_m,\infty]`. + + Parameters + ========== + + xm : Real number, `x_m > 0`, a scale + alpha : Real number, `\alpha > 0`, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Pareto, density + >>> from sympy import Symbol + + >>> xm = Symbol("xm", positive=True) + >>> beta = Symbol("beta", positive=True) + >>> z = Symbol("z") + + >>> X = Pareto("x", xm, beta) + + >>> density(X)(z) + beta*xm**beta*z**(-beta - 1) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Pareto_distribution + .. [2] https://mathworld.wolfram.com/ParetoDistribution.html + + """ + + return rv(name, ParetoDistribution, (xm, alpha)) + +#------------------------------------------------------------------------------- +# PowerFunction distribution --------------------------------------------------- + + +class PowerFunctionDistribution(SingleContinuousDistribution): + _argnames=('alpha','a','b') + + @property + def set(self): + return Interval(self.a, self.b) + + @staticmethod + def check(alpha, a, b): + _value_check(a.is_real, "Continuous Boundary parameter should be real.") + _value_check(b.is_real, "Continuous Boundary parameter should be real.") + _value_check(a < b, " 'a' the left Boundary must be smaller than 'b' the right Boundary." ) + _value_check(alpha.is_positive, "Continuous Shape parameter should be positive.") + + def pdf(self, x): + alpha, a, b = self.alpha, self.a, self.b + num = alpha*(x - a)**(alpha - 1) + den = (b - a)**alpha + return num/den + +def PowerFunction(name, alpha, a, b): + r""" + Creates a continuous random variable with a Power Function Distribution. + + Explanation + =========== + + The density of PowerFunction distribution is given by + + .. math:: + f(x) := \frac{{\alpha}(x - a)^{\alpha - 1}}{(b - a)^{\alpha}} + + with :math:`x \in [a,b]`. + + Parameters + ========== + + alpha : Positive number, `0 < \alpha`, the shape parameter + a : Real number, :math:`-\infty < a`, the left boundary + b : Real number, :math:`a < b < \infty`, the right boundary + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import PowerFunction, density, cdf, E, variance + >>> from sympy import Symbol + >>> alpha = Symbol("alpha", positive=True) + >>> a = Symbol("a", real=True) + >>> b = Symbol("b", real=True) + >>> z = Symbol("z") + + >>> X = PowerFunction("X", 2, a, b) + + >>> density(X)(z) + (-2*a + 2*z)/(-a + b)**2 + + >>> cdf(X)(z) + Piecewise((a**2/(a**2 - 2*a*b + b**2) - 2*a*z/(a**2 - 2*a*b + b**2) + + z**2/(a**2 - 2*a*b + b**2), a <= z), (0, True)) + + >>> alpha = 2 + >>> a = 0 + >>> b = 1 + >>> Y = PowerFunction("Y", alpha, a, b) + + >>> E(Y) + 2/3 + + >>> variance(Y) + 1/18 + + References + ========== + + .. [1] https://web.archive.org/web/20200204081320/http://www.mathwave.com/help/easyfit/html/analyses/distributions/power_func.html + + """ + return rv(name, PowerFunctionDistribution, (alpha, a, b)) + +#------------------------------------------------------------------------------- +# QuadraticU distribution ------------------------------------------------------ + + +class QuadraticUDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b') + + @property + def set(self): + return Interval(self.a, self.b) + + @staticmethod + def check(a, b): + _value_check(b > a, "Parameter b must be in range (%s, oo)."%(a)) + + def pdf(self, x): + a, b = self.a, self.b + alpha = 12 / (b-a)**3 + beta = (a+b) / 2 + return Piecewise( + (alpha * (x-beta)**2, And(a<=x, x<=b)), + (S.Zero, True)) + + def _moment_generating_function(self, t): + a, b = self.a, self.b + return -3 * (exp(a*t) * (4 + (a**2 + 2*a*(-2 + b) + b**2) * t) \ + - exp(b*t) * (4 + (-4*b + (a + b)**2) * t)) / ((a-b)**3 * t**2) + + def _characteristic_function(self, t): + a, b = self.a, self.b + return -3*I*(exp(I*a*t*exp(I*b*t)) * (4*I - (-4*b + (a+b)**2)*t)) \ + / ((a-b)**3 * t**2) + + +def QuadraticU(name, a, b): + r""" + Create a Continuous Random Variable with a U-quadratic distribution. + + Explanation + =========== + + The density of the U-quadratic distribution is given by + + .. math:: + f(x) := \alpha (x-\beta)^2 + + with :math:`x \in [a,b]`. + + Parameters + ========== + + a : Real number + b : Real number, :math:`a < b` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import QuadraticU, density + >>> from sympy import Symbol, pprint + + >>> a = Symbol("a", real=True) + >>> b = Symbol("b", real=True) + >>> z = Symbol("z") + + >>> X = QuadraticU("x", a, b) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + / 2 + | / a b \ + |12*|- - - - + z| + | \ 2 2 / + <----------------- for And(b >= z, a <= z) + | 3 + | (-a + b) + | + \ 0 otherwise + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/U-quadratic_distribution + + """ + + return rv(name, QuadraticUDistribution, (a, b)) + +#------------------------------------------------------------------------------- +# RaisedCosine distribution ---------------------------------------------------- + + +class RaisedCosineDistribution(SingleContinuousDistribution): + _argnames = ('mu', 's') + + @property + def set(self): + return Interval(self.mu - self.s, self.mu + self.s) + + @staticmethod + def check(mu, s): + _value_check(s > 0, "s must be positive") + + def pdf(self, x): + mu, s = self.mu, self.s + return Piecewise( + ((1+cos(pi*(x-mu)/s)) / (2*s), And(mu-s<=x, x<=mu+s)), + (S.Zero, True)) + + def _characteristic_function(self, t): + mu, s = self.mu, self.s + return Piecewise((exp(-I*pi*mu/s)/2, Eq(t, -pi/s)), + (exp(I*pi*mu/s)/2, Eq(t, pi/s)), + (pi**2*sin(s*t)*exp(I*mu*t) / (s*t*(pi**2 - s**2*t**2)), True)) + + def _moment_generating_function(self, t): + mu, s = self.mu, self.s + return pi**2 * sinh(s*t) * exp(mu*t) / (s*t*(pi**2 + s**2*t**2)) + +def RaisedCosine(name, mu, s): + r""" + Create a Continuous Random Variable with a raised cosine distribution. + + Explanation + =========== + + The density of the raised cosine distribution is given by + + .. math:: + f(x) := \frac{1}{2s}\left(1+\cos\left(\frac{x-\mu}{s}\pi\right)\right) + + with :math:`x \in [\mu-s,\mu+s]`. + + Parameters + ========== + + mu : Real number + s : Real number, `s > 0` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import RaisedCosine, density + >>> from sympy import Symbol, pprint + + >>> mu = Symbol("mu", real=True) + >>> s = Symbol("s", positive=True) + >>> z = Symbol("z") + + >>> X = RaisedCosine("x", mu, s) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + / /pi*(-mu + z)\ + |cos|------------| + 1 + | \ s / + <--------------------- for And(z >= mu - s, z <= mu + s) + | 2*s + | + \ 0 otherwise + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Raised_cosine_distribution + + """ + + return rv(name, RaisedCosineDistribution, (mu, s)) + +#------------------------------------------------------------------------------- +# Rayleigh distribution -------------------------------------------------------- + + +class RayleighDistribution(SingleContinuousDistribution): + _argnames = ('sigma',) + + set = Interval(0, oo) + + @staticmethod + def check(sigma): + _value_check(sigma > 0, "Scale parameter sigma must be positive.") + + def pdf(self, x): + sigma = self.sigma + return x/sigma**2*exp(-x**2/(2*sigma**2)) + + def _cdf(self, x): + sigma = self.sigma + return 1 - exp(-(x**2/(2*sigma**2))) + + def _characteristic_function(self, t): + sigma = self.sigma + return 1 - sigma*t*exp(-sigma**2*t**2/2) * sqrt(pi/2) * (erfi(sigma*t/sqrt(2)) - I) + + def _moment_generating_function(self, t): + sigma = self.sigma + return 1 + sigma*t*exp(sigma**2*t**2/2) * sqrt(pi/2) * (erf(sigma*t/sqrt(2)) + 1) + + +def Rayleigh(name, sigma): + r""" + Create a continuous random variable with a Rayleigh distribution. + + Explanation + =========== + + The density of the Rayleigh distribution is given by + + .. math :: + f(x) := \frac{x}{\sigma^2} e^{-x^2/2\sigma^2} + + with :math:`x > 0`. + + Parameters + ========== + + sigma : Real number, `\sigma > 0` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Rayleigh, density, E, variance + >>> from sympy import Symbol + + >>> sigma = Symbol("sigma", positive=True) + >>> z = Symbol("z") + + >>> X = Rayleigh("x", sigma) + + >>> density(X)(z) + z*exp(-z**2/(2*sigma**2))/sigma**2 + + >>> E(X) + sqrt(2)*sqrt(pi)*sigma/2 + + >>> variance(X) + -pi*sigma**2/2 + 2*sigma**2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Rayleigh_distribution + .. [2] https://mathworld.wolfram.com/RayleighDistribution.html + + """ + + return rv(name, RayleighDistribution, (sigma, )) + +#------------------------------------------------------------------------------- +# Reciprocal distribution -------------------------------------------------------- + +class ReciprocalDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b') + + @property + def set(self): + return Interval(self.a, self.b) + + @staticmethod + def check(a, b): + _value_check(a > 0, "Parameter > 0. a = %s"%a) + _value_check((a < b), + "Parameter b must be in range (%s, +oo]. b = %s"%(a, b)) + + def pdf(self, x): + a, b = self.a, self.b + return 1/(x*(log(b) - log(a))) + + +def Reciprocal(name, a, b): + r"""Creates a continuous random variable with a reciprocal distribution. + + + Parameters + ========== + + a : Real number, :math:`0 < a` + b : Real number, :math:`a < b` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Reciprocal, density, cdf + >>> from sympy import symbols + >>> a, b, x = symbols('a, b, x', positive=True) + >>> R = Reciprocal('R', a, b) + + >>> density(R)(x) + 1/(x*(-log(a) + log(b))) + >>> cdf(R)(x) + Piecewise((log(a)/(log(a) - log(b)) - log(x)/(log(a) - log(b)), a <= x), (0, True)) + + Reference + ========= + + .. [1] https://en.wikipedia.org/wiki/Reciprocal_distribution + + """ + return rv(name, ReciprocalDistribution, (a, b)) + + +#------------------------------------------------------------------------------- +# Shifted Gompertz distribution ------------------------------------------------ + + +class ShiftedGompertzDistribution(SingleContinuousDistribution): + _argnames = ('b', 'eta') + + set = Interval(0, oo) + + @staticmethod + def check(b, eta): + _value_check(b > 0, "b must be positive") + _value_check(eta > 0, "eta must be positive") + + def pdf(self, x): + b, eta = self.b, self.eta + return b*exp(-b*x)*exp(-eta*exp(-b*x))*(1+eta*(1-exp(-b*x))) + +def ShiftedGompertz(name, b, eta): + r""" + Create a continuous random variable with a Shifted Gompertz distribution. + + Explanation + =========== + + The density of the Shifted Gompertz distribution is given by + + .. math:: + f(x) := b e^{-b x} e^{-\eta \exp(-b x)} \left[1 + \eta(1 - e^(-bx)) \right] + + with :math:`x \in [0, \infty)`. + + Parameters + ========== + + b : Real number, `b > 0`, a scale + eta : Real number, `\eta > 0`, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + >>> from sympy.stats import ShiftedGompertz, density + >>> from sympy import Symbol + + >>> b = Symbol("b", positive=True) + >>> eta = Symbol("eta", positive=True) + >>> x = Symbol("x") + + >>> X = ShiftedGompertz("x", b, eta) + + >>> density(X)(x) + b*(eta*(1 - exp(-b*x)) + 1)*exp(-b*x)*exp(-eta*exp(-b*x)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Shifted_Gompertz_distribution + + """ + return rv(name, ShiftedGompertzDistribution, (b, eta)) + +#------------------------------------------------------------------------------- +# StudentT distribution -------------------------------------------------------- + + +class StudentTDistribution(SingleContinuousDistribution): + _argnames = ('nu',) + + set = Interval(-oo, oo) + + @staticmethod + def check(nu): + _value_check(nu > 0, "Degrees of freedom nu must be positive.") + + def pdf(self, x): + nu = self.nu + return 1/(sqrt(nu)*beta_fn(S.Half, nu/2))*(1 + x**2/nu)**(-(nu + 1)/2) + + def _cdf(self, x): + nu = self.nu + return S.Half + x*gamma((nu+1)/2)*hyper((S.Half, (nu+1)/2), + (Rational(3, 2),), -x**2/nu)/(sqrt(pi*nu)*gamma(nu/2)) + + def _moment_generating_function(self, t): + raise NotImplementedError('The moment generating function for the Student-T distribution is undefined.') + + +def StudentT(name, nu): + r""" + Create a continuous random variable with a student's t distribution. + + Explanation + =========== + + The density of the student's t distribution is given by + + .. math:: + f(x) := \frac{\Gamma \left(\frac{\nu+1}{2} \right)} + {\sqrt{\nu\pi}\Gamma \left(\frac{\nu}{2} \right)} + \left(1+\frac{x^2}{\nu} \right)^{-\frac{\nu+1}{2}} + + Parameters + ========== + + nu : Real number, `\nu > 0`, the degrees of freedom + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import StudentT, density, cdf + >>> from sympy import Symbol, pprint + + >>> nu = Symbol("nu", positive=True) + >>> z = Symbol("z") + + >>> X = StudentT("x", nu) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + nu 1 + - -- - - + 2 2 + / 2\ + | z | + |1 + --| + \ nu/ + ----------------- + ____ / nu\ + \/ nu *B|1/2, --| + \ 2 / + + >>> cdf(X)(z) + 1/2 + z*gamma(nu/2 + 1/2)*hyper((1/2, nu/2 + 1/2), (3/2,), + -z**2/nu)/(sqrt(pi)*sqrt(nu)*gamma(nu/2)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Student_t-distribution + .. [2] https://mathworld.wolfram.com/Studentst-Distribution.html + + """ + + return rv(name, StudentTDistribution, (nu, )) + +#------------------------------------------------------------------------------- +# Trapezoidal distribution ------------------------------------------------------ + + +class TrapezoidalDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b', 'c', 'd') + + @property + def set(self): + return Interval(self.a, self.d) + + @staticmethod + def check(a, b, c, d): + _value_check(a < d, "Lower bound parameter a < %s. a = %s"%(d, a)) + _value_check((a <= b, b < c), + "Level start parameter b must be in range [%s, %s). b = %s"%(a, c, b)) + _value_check((b < c, c <= d), + "Level end parameter c must be in range (%s, %s]. c = %s"%(b, d, c)) + _value_check(d >= c, "Upper bound parameter d > %s. d = %s"%(c, d)) + + def pdf(self, x): + a, b, c, d = self.a, self.b, self.c, self.d + return Piecewise( + (2*(x-a) / ((b-a)*(d+c-a-b)), And(a <= x, x < b)), + (2 / (d+c-a-b), And(b <= x, x < c)), + (2*(d-x) / ((d-c)*(d+c-a-b)), And(c <= x, x <= d)), + (S.Zero, True)) + +def Trapezoidal(name, a, b, c, d): + r""" + Create a continuous random variable with a trapezoidal distribution. + + Explanation + =========== + + The density of the trapezoidal distribution is given by + + .. math:: + f(x) := \begin{cases} + 0 & \mathrm{for\ } x < a, \\ + \frac{2(x-a)}{(b-a)(d+c-a-b)} & \mathrm{for\ } a \le x < b, \\ + \frac{2}{d+c-a-b} & \mathrm{for\ } b \le x < c, \\ + \frac{2(d-x)}{(d-c)(d+c-a-b)} & \mathrm{for\ } c \le x < d, \\ + 0 & \mathrm{for\ } d < x. + \end{cases} + + Parameters + ========== + + a : Real number, :math:`a < d` + b : Real number, :math:`a \le b < c` + c : Real number, :math:`b < c \le d` + d : Real number + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Trapezoidal, density + >>> from sympy import Symbol, pprint + + >>> a = Symbol("a") + >>> b = Symbol("b") + >>> c = Symbol("c") + >>> d = Symbol("d") + >>> z = Symbol("z") + + >>> X = Trapezoidal("x", a,b,c,d) + + >>> pprint(density(X)(z), use_unicode=False) + / -2*a + 2*z + |------------------------- for And(a <= z, b > z) + |(-a + b)*(-a - b + c + d) + | + | 2 + | -------------- for And(b <= z, c > z) + < -a - b + c + d + | + | 2*d - 2*z + |------------------------- for And(d >= z, c <= z) + |(-c + d)*(-a - b + c + d) + | + \ 0 otherwise + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Trapezoidal_distribution + + """ + return rv(name, TrapezoidalDistribution, (a, b, c, d)) + +#------------------------------------------------------------------------------- +# Triangular distribution ------------------------------------------------------ + + +class TriangularDistribution(SingleContinuousDistribution): + _argnames = ('a', 'b', 'c') + + @property + def set(self): + return Interval(self.a, self.b) + + @staticmethod + def check(a, b, c): + _value_check(b > a, "Parameter b > %s. b = %s"%(a, b)) + _value_check((a <= c, c <= b), + "Parameter c must be in range [%s, %s]. c = %s"%(a, b, c)) + + def pdf(self, x): + a, b, c = self.a, self.b, self.c + return Piecewise( + (2*(x - a)/((b - a)*(c - a)), And(a <= x, x < c)), + (2/(b - a), Eq(x, c)), + (2*(b - x)/((b - a)*(b - c)), And(c < x, x <= b)), + (S.Zero, True)) + + def _characteristic_function(self, t): + a, b, c = self.a, self.b, self.c + return -2 *((b-c) * exp(I*a*t) - (b-a) * exp(I*c*t) + (c-a) * exp(I*b*t)) / ((b-a)*(c-a)*(b-c)*t**2) + + def _moment_generating_function(self, t): + a, b, c = self.a, self.b, self.c + return 2 * ((b - c) * exp(a * t) - (b - a) * exp(c * t) + (c - a) * exp(b * t)) / ( + (b - a) * (c - a) * (b - c) * t ** 2) + + +def Triangular(name, a, b, c): + r""" + Create a continuous random variable with a triangular distribution. + + Explanation + =========== + + The density of the triangular distribution is given by + + .. math:: + f(x) := \begin{cases} + 0 & \mathrm{for\ } x < a, \\ + \frac{2(x-a)}{(b-a)(c-a)} & \mathrm{for\ } a \le x < c, \\ + \frac{2}{b-a} & \mathrm{for\ } x = c, \\ + \frac{2(b-x)}{(b-a)(b-c)} & \mathrm{for\ } c < x \le b, \\ + 0 & \mathrm{for\ } b < x. + \end{cases} + + Parameters + ========== + + a : Real number, :math:`a \in \left(-\infty, \infty\right)` + b : Real number, :math:`a < b` + c : Real number, :math:`a \leq c \leq b` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Triangular, density + >>> from sympy import Symbol, pprint + + >>> a = Symbol("a") + >>> b = Symbol("b") + >>> c = Symbol("c") + >>> z = Symbol("z") + + >>> X = Triangular("x", a,b,c) + + >>> pprint(density(X)(z), use_unicode=False) + / -2*a + 2*z + |----------------- for And(a <= z, c > z) + |(-a + b)*(-a + c) + | + | 2 + | ------ for c = z + < -a + b + | + | 2*b - 2*z + |---------------- for And(b >= z, c < z) + |(-a + b)*(b - c) + | + \ 0 otherwise + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Triangular_distribution + .. [2] https://mathworld.wolfram.com/TriangularDistribution.html + + """ + + return rv(name, TriangularDistribution, (a, b, c)) + +#------------------------------------------------------------------------------- +# Uniform distribution --------------------------------------------------------- + + +class UniformDistribution(SingleContinuousDistribution): + _argnames = ('left', 'right') + + @property + def set(self): + return Interval(self.left, self.right) + + @staticmethod + def check(left, right): + _value_check(left < right, "Lower limit should be less than Upper limit.") + + def pdf(self, x): + left, right = self.left, self.right + return Piecewise( + (S.One/(right - left), And(left <= x, x <= right)), + (S.Zero, True) + ) + + def _cdf(self, x): + left, right = self.left, self.right + return Piecewise( + (S.Zero, x < left), + ((x - left)/(right - left), x <= right), + (S.One, True) + ) + + def _characteristic_function(self, t): + left, right = self.left, self.right + return Piecewise(((exp(I*t*right) - exp(I*t*left)) / (I*t*(right - left)), Ne(t, 0)), + (S.One, True)) + + def _moment_generating_function(self, t): + left, right = self.left, self.right + return Piecewise(((exp(t*right) - exp(t*left)) / (t * (right - left)), Ne(t, 0)), + (S.One, True)) + + def expectation(self, expr, var, **kwargs): + kwargs['evaluate'] = True + result = SingleContinuousDistribution.expectation(self, expr, var, **kwargs) + result = result.subs({Max(self.left, self.right): self.right, + Min(self.left, self.right): self.left}) + return result + + +def Uniform(name, left, right): + r""" + Create a continuous random variable with a uniform distribution. + + Explanation + =========== + + The density of the uniform distribution is given by + + .. math:: + f(x) := \begin{cases} + \frac{1}{b - a} & \text{for } x \in [a,b] \\ + 0 & \text{otherwise} + \end{cases} + + with :math:`x \in [a,b]`. + + Parameters + ========== + + a : Real number, :math:`-\infty < a`, the left boundary + b : Real number, :math:`a < b < \infty`, the right boundary + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Uniform, density, cdf, E, variance + >>> from sympy import Symbol, simplify + + >>> a = Symbol("a", negative=True) + >>> b = Symbol("b", positive=True) + >>> z = Symbol("z") + + >>> X = Uniform("x", a, b) + + >>> density(X)(z) + Piecewise((1/(-a + b), (b >= z) & (a <= z)), (0, True)) + + >>> cdf(X)(z) + Piecewise((0, a > z), ((-a + z)/(-a + b), b >= z), (1, True)) + + >>> E(X) + a/2 + b/2 + + >>> simplify(variance(X)) + a**2/12 - a*b/6 + b**2/12 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Uniform_distribution_%28continuous%29 + .. [2] https://mathworld.wolfram.com/UniformDistribution.html + + """ + + return rv(name, UniformDistribution, (left, right)) + +#------------------------------------------------------------------------------- +# UniformSum distribution ------------------------------------------------------ + + +class UniformSumDistribution(SingleContinuousDistribution): + _argnames = ('n',) + + @property + def set(self): + return Interval(0, self.n) + + @staticmethod + def check(n): + _value_check((n > 0, n.is_integer), + "Parameter n must be positive integer.") + + def pdf(self, x): + n = self.n + k = Dummy("k") + return 1/factorial( + n - 1)*Sum((-1)**k*binomial(n, k)*(x - k)**(n - 1), (k, 0, floor(x))) + + def _cdf(self, x): + n = self.n + k = Dummy("k") + return Piecewise((S.Zero, x < 0), + (1/factorial(n)*Sum((-1)**k*binomial(n, k)*(x - k)**(n), + (k, 0, floor(x))), x <= n), + (S.One, True)) + + def _characteristic_function(self, t): + return ((exp(I*t) - 1) / (I*t))**self.n + + def _moment_generating_function(self, t): + return ((exp(t) - 1) / t)**self.n + +def UniformSum(name, n): + r""" + Create a continuous random variable with an Irwin-Hall distribution. + + Explanation + =========== + + The probability distribution function depends on a single parameter + $n$ which is an integer. + + The density of the Irwin-Hall distribution is given by + + .. math :: + f(x) := \frac{1}{(n-1)!}\sum_{k=0}^{\left\lfloor x\right\rfloor}(-1)^k + \binom{n}{k}(x-k)^{n-1} + + Parameters + ========== + + n : A positive integer, `n > 0` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import UniformSum, density, cdf + >>> from sympy import Symbol, pprint + + >>> n = Symbol("n", integer=True) + >>> z = Symbol("z") + + >>> X = UniformSum("x", n) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + floor(z) + ___ + \ ` + \ k n - 1 /n\ + ) (-1) *(-k + z) *| | + / \k/ + /__, + k = 0 + -------------------------------- + (n - 1)! + + >>> cdf(X)(z) + Piecewise((0, z < 0), (Sum((-1)**_k*(-_k + z)**n*binomial(n, _k), + (_k, 0, floor(z)))/factorial(n), n >= z), (1, True)) + + + Compute cdf with specific 'x' and 'n' values as follows : + >>> cdf(UniformSum("x", 5), evaluate=False)(2).doit() + 9/40 + + The argument evaluate=False prevents an attempt at evaluation + of the sum for general n, before the argument 2 is passed. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Uniform_sum_distribution + .. [2] https://mathworld.wolfram.com/UniformSumDistribution.html + + """ + + return rv(name, UniformSumDistribution, (n, )) + +#------------------------------------------------------------------------------- +# VonMises distribution -------------------------------------------------------- + + +class VonMisesDistribution(SingleContinuousDistribution): + _argnames = ('mu', 'k') + + set = Interval(0, 2*pi) + + @staticmethod + def check(mu, k): + _value_check(k > 0, "k must be positive") + + def pdf(self, x): + mu, k = self.mu, self.k + return exp(k*cos(x-mu)) / (2*pi*besseli(0, k)) + +def VonMises(name, mu, k): + r""" + Create a Continuous Random Variable with a von Mises distribution. + + Explanation + =========== + + The density of the von Mises distribution is given by + + .. math:: + f(x) := \frac{e^{\kappa\cos(x-\mu)}}{2\pi I_0(\kappa)} + + with :math:`x \in [0,2\pi]`. + + Parameters + ========== + + mu : Real number + Measure of location. + k : Real number + Measure of concentration. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import VonMises, density + >>> from sympy import Symbol, pprint + + >>> mu = Symbol("mu") + >>> k = Symbol("k", positive=True) + >>> z = Symbol("z") + + >>> X = VonMises("x", mu, k) + + >>> D = density(X)(z) + >>> pprint(D, use_unicode=False) + k*cos(mu - z) + e + ------------------ + 2*pi*besseli(0, k) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Von_Mises_distribution + .. [2] https://mathworld.wolfram.com/vonMisesDistribution.html + + """ + + return rv(name, VonMisesDistribution, (mu, k)) + +#------------------------------------------------------------------------------- +# Weibull distribution --------------------------------------------------------- + + +class WeibullDistribution(SingleContinuousDistribution): + _argnames = ('alpha', 'beta') + + set = Interval(0, oo) + + @staticmethod + def check(alpha, beta): + _value_check(alpha > 0, "Alpha must be positive") + _value_check(beta > 0, "Beta must be positive") + + def pdf(self, x): + alpha, beta = self.alpha, self.beta + return beta * (x/alpha)**(beta - 1) * exp(-(x/alpha)**beta) / alpha + + +def Weibull(name, alpha, beta): + r""" + Create a continuous random variable with a Weibull distribution. + + Explanation + =========== + + The density of the Weibull distribution is given by + + .. math:: + f(x) := \begin{cases} + \frac{k}{\lambda}\left(\frac{x}{\lambda}\right)^{k-1} + e^{-(x/\lambda)^{k}} & x\geq0\\ + 0 & x<0 + \end{cases} + + Parameters + ========== + + lambda : Real number, $\lambda > 0$, a scale + k : Real number, $k > 0$, a shape + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Weibull, density, E, variance + >>> from sympy import Symbol, simplify + + >>> l = Symbol("lambda", positive=True) + >>> k = Symbol("k", positive=True) + >>> z = Symbol("z") + + >>> X = Weibull("x", l, k) + + >>> density(X)(z) + k*(z/lambda)**(k - 1)*exp(-(z/lambda)**k)/lambda + + >>> simplify(E(X)) + lambda*gamma(1 + 1/k) + + >>> simplify(variance(X)) + lambda**2*(-gamma(1 + 1/k)**2 + gamma(1 + 2/k)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Weibull_distribution + .. [2] https://mathworld.wolfram.com/WeibullDistribution.html + + """ + + return rv(name, WeibullDistribution, (alpha, beta)) + +#------------------------------------------------------------------------------- +# Wigner semicircle distribution ----------------------------------------------- + + +class WignerSemicircleDistribution(SingleContinuousDistribution): + _argnames = ('R',) + + @property + def set(self): + return Interval(-self.R, self.R) + + @staticmethod + def check(R): + _value_check(R > 0, "Radius R must be positive.") + + def pdf(self, x): + R = self.R + return 2/(pi*R**2)*sqrt(R**2 - x**2) + + def _characteristic_function(self, t): + return Piecewise((2 * besselj(1, self.R*t) / (self.R*t), Ne(t, 0)), + (S.One, True)) + + def _moment_generating_function(self, t): + return Piecewise((2 * besseli(1, self.R*t) / (self.R*t), Ne(t, 0)), + (S.One, True)) + +def WignerSemicircle(name, R): + r""" + Create a continuous random variable with a Wigner semicircle distribution. + + Explanation + =========== + + The density of the Wigner semicircle distribution is given by + + .. math:: + f(x) := \frac2{\pi R^2}\,\sqrt{R^2-x^2} + + with :math:`x \in [-R,R]`. + + Parameters + ========== + + R : Real number, `R > 0`, the radius + + Returns + ======= + + A RandomSymbol. + + Examples + ======== + + >>> from sympy.stats import WignerSemicircle, density, E + >>> from sympy import Symbol + + >>> R = Symbol("R", positive=True) + >>> z = Symbol("z") + + >>> X = WignerSemicircle("x", R) + + >>> density(X)(z) + 2*sqrt(R**2 - z**2)/(pi*R**2) + + >>> E(X) + 0 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Wigner_semicircle_distribution + .. [2] https://mathworld.wolfram.com/WignersSemicircleLaw.html + + """ + + return rv(name, WignerSemicircleDistribution, (R,)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/drv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/drv.py new file mode 100644 index 0000000000000000000000000000000000000000..dea14f2dfd1078c223c61bb5cd1373105e72ea28 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/drv.py @@ -0,0 +1,350 @@ +from sympy.concrete.summations import (Sum, summation) +from sympy.core.basic import Basic +from sympy.core.cache import cacheit +from sympy.core.function import Lambda +from sympy.core.numbers import I +from sympy.core.relational import (Eq, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, symbols) +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import factorial +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.piecewise import Piecewise +from sympy.logic.boolalg import And +from sympy.polys.polytools import poly +from sympy.series.series import series + +from sympy.polys.polyerrors import PolynomialError +from sympy.stats.crv import reduce_rational_inequalities_wrap +from sympy.stats.rv import (NamedArgsMixin, SinglePSpace, SingleDomain, + random_symbols, PSpace, ConditionalDomain, RandomDomain, + ProductDomain, Distribution) +from sympy.stats.symbolic_probability import Probability +from sympy.sets.fancysets import Range, FiniteSet +from sympy.sets.sets import Union +from sympy.sets.contains import Contains +from sympy.utilities import filldedent +from sympy.core.sympify import _sympify + + +class DiscreteDistribution(Distribution): + def __call__(self, *args): + return self.pdf(*args) + + +class SingleDiscreteDistribution(DiscreteDistribution, NamedArgsMixin): + """ Discrete distribution of a single variable. + + Serves as superclass for PoissonDistribution etc.... + + Provides methods for pdf, cdf, and sampling + + See Also: + sympy.stats.crv_types.* + """ + + set = S.Integers + + def __new__(cls, *args): + args = list(map(sympify, args)) + return Basic.__new__(cls, *args) + + @staticmethod + def check(*args): + pass + + @cacheit + def compute_cdf(self, **kwargs): + """ Compute the CDF from the PDF. + + Returns a Lambda. + """ + x = symbols('x', integer=True, cls=Dummy) + z = symbols('z', real=True, cls=Dummy) + left_bound = self.set.inf + + # CDF is integral of PDF from left bound to z + pdf = self.pdf(x) + cdf = summation(pdf, (x, left_bound, floor(z)), **kwargs) + # CDF Ensure that CDF left of left_bound is zero + cdf = Piecewise((cdf, z >= left_bound), (0, True)) + return Lambda(z, cdf) + + def _cdf(self, x): + return None + + def cdf(self, x, **kwargs): + """ Cumulative density function """ + if not kwargs: + cdf = self._cdf(x) + if cdf is not None: + return cdf + return self.compute_cdf(**kwargs)(x) + + @cacheit + def compute_characteristic_function(self, **kwargs): + """ Compute the characteristic function from the PDF. + + Returns a Lambda. + """ + x, t = symbols('x, t', real=True, cls=Dummy) + pdf = self.pdf(x) + cf = summation(exp(I*t*x)*pdf, (x, self.set.inf, self.set.sup)) + return Lambda(t, cf) + + def _characteristic_function(self, t): + return None + + def characteristic_function(self, t, **kwargs): + """ Characteristic function """ + if not kwargs: + cf = self._characteristic_function(t) + if cf is not None: + return cf + return self.compute_characteristic_function(**kwargs)(t) + + @cacheit + def compute_moment_generating_function(self, **kwargs): + t = Dummy('t', real=True) + x = Dummy('x', integer=True) + pdf = self.pdf(x) + mgf = summation(exp(t*x)*pdf, (x, self.set.inf, self.set.sup)) + return Lambda(t, mgf) + + def _moment_generating_function(self, t): + return None + + def moment_generating_function(self, t, **kwargs): + if not kwargs: + mgf = self._moment_generating_function(t) + if mgf is not None: + return mgf + return self.compute_moment_generating_function(**kwargs)(t) + + @cacheit + def compute_quantile(self, **kwargs): + """ Compute the Quantile from the PDF. + + Returns a Lambda. + """ + x = Dummy('x', integer=True) + p = Dummy('p', real=True) + left_bound = self.set.inf + pdf = self.pdf(x) + cdf = summation(pdf, (x, left_bound, x), **kwargs) + set = ((x, p <= cdf), ) + return Lambda(p, Piecewise(*set)) + + def _quantile(self, x): + return None + + def quantile(self, x, **kwargs): + """ Cumulative density function """ + if not kwargs: + quantile = self._quantile(x) + if quantile is not None: + return quantile + return self.compute_quantile(**kwargs)(x) + + def expectation(self, expr, var, evaluate=True, **kwargs): + """ Expectation of expression over distribution """ + # TODO: support discrete sets with non integer stepsizes + + if evaluate: + try: + p = poly(expr, var) + + t = Dummy('t', real=True) + + mgf = self.moment_generating_function(t) + deg = p.degree() + taylor = poly(series(mgf, t, 0, deg + 1).removeO(), t) + result = 0 + for k in range(deg+1): + result += p.coeff_monomial(var ** k) * taylor.coeff_monomial(t ** k) * factorial(k) + + return result + + except PolynomialError: + return summation(expr * self.pdf(var), + (var, self.set.inf, self.set.sup), **kwargs) + + else: + return Sum(expr * self.pdf(var), + (var, self.set.inf, self.set.sup), **kwargs) + + def __call__(self, *args): + return self.pdf(*args) + + +class DiscreteDomain(RandomDomain): + """ + A domain with discrete support with step size one. + Represented using symbols and Range. + """ + is_Discrete = True + +class SingleDiscreteDomain(DiscreteDomain, SingleDomain): + def as_boolean(self): + return Contains(self.symbol, self.set) + + +class ConditionalDiscreteDomain(DiscreteDomain, ConditionalDomain): + """ + Domain with discrete support of step size one, that is restricted by + some condition. + """ + @property + def set(self): + rv = self.symbols + if len(self.symbols) > 1: + raise NotImplementedError(filldedent(''' + Multivariate conditional domains are not yet implemented.''')) + rv = list(rv)[0] + return reduce_rational_inequalities_wrap(self.condition, + rv).intersect(self.fulldomain.set) + + +class DiscretePSpace(PSpace): + is_real = True + is_Discrete = True + + @property + def pdf(self): + return self.density(*self.symbols) + + def where(self, condition): + rvs = random_symbols(condition) + assert all(r.symbol in self.symbols for r in rvs) + if len(rvs) > 1: + raise NotImplementedError(filldedent('''Multivariate discrete + random variables are not yet supported.''')) + conditional_domain = reduce_rational_inequalities_wrap(condition, + rvs[0]) + conditional_domain = conditional_domain.intersect(self.domain.set) + return SingleDiscreteDomain(rvs[0].symbol, conditional_domain) + + def probability(self, condition): + complement = isinstance(condition, Ne) + if complement: + condition = Eq(condition.args[0], condition.args[1]) + try: + _domain = self.where(condition).set + if condition == False or _domain is S.EmptySet: + return S.Zero + if condition == True or _domain == self.domain.set: + return S.One + prob = self.eval_prob(_domain) + except NotImplementedError: + from sympy.stats.rv import density + expr = condition.lhs - condition.rhs + dens = density(expr) + if not isinstance(dens, DiscreteDistribution): + from sympy.stats.drv_types import DiscreteDistributionHandmade + dens = DiscreteDistributionHandmade(dens) + z = Dummy('z', real=True) + space = SingleDiscretePSpace(z, dens) + prob = space.probability(condition.__class__(space.value, 0)) + if prob is None: + prob = Probability(condition) + return prob if not complement else S.One - prob + + def eval_prob(self, _domain): + sym = list(self.symbols)[0] + if isinstance(_domain, Range): + n = symbols('n', integer=True) + inf, sup, step = (r for r in _domain.args) + summand = ((self.pdf).replace( + sym, n*step)) + rv = summation(summand, + (n, inf/step, (sup)/step - 1)).doit() + return rv + elif isinstance(_domain, FiniteSet): + pdf = Lambda(sym, self.pdf) + rv = sum(pdf(x) for x in _domain) + return rv + elif isinstance(_domain, Union): + rv = sum(self.eval_prob(x) for x in _domain.args) + return rv + + def conditional_space(self, condition): + # XXX: Converting from set to tuple. The order matters to Lambda + # though so we should be starting with a set... + density = Lambda(tuple(self.symbols), self.pdf/self.probability(condition)) + condition = condition.xreplace({rv: rv.symbol for rv in self.values}) + domain = ConditionalDiscreteDomain(self.domain, condition) + return DiscretePSpace(domain, density) + +class ProductDiscreteDomain(ProductDomain, DiscreteDomain): + def as_boolean(self): + return And(*[domain.as_boolean for domain in self.domains]) + +class SingleDiscretePSpace(DiscretePSpace, SinglePSpace): + """ Discrete probability space over a single univariate variable """ + is_real = True + + @property + def set(self): + return self.distribution.set + + @property + def domain(self): + return SingleDiscreteDomain(self.symbol, self.set) + + def sample(self, size=(), library='scipy', seed=None): + """ + Internal sample method. + + Returns dictionary mapping RandomSymbol to realization value. + """ + return {self.value: self.distribution.sample(size, library=library, seed=seed)} + + def compute_expectation(self, expr, rvs=None, evaluate=True, **kwargs): + rvs = rvs or (self.value,) + if self.value not in rvs: + return expr + + expr = _sympify(expr) + expr = expr.xreplace({rv: rv.symbol for rv in rvs}) + + x = self.value.symbol + try: + return self.distribution.expectation(expr, x, evaluate=evaluate, + **kwargs) + except NotImplementedError: + return Sum(expr * self.pdf, (x, self.set.inf, self.set.sup), + **kwargs) + + def compute_cdf(self, expr, **kwargs): + if expr == self.value: + x = Dummy("x", real=True) + return Lambda(x, self.distribution.cdf(x, **kwargs)) + else: + raise NotImplementedError() + + def compute_density(self, expr, **kwargs): + if expr == self.value: + return self.distribution + raise NotImplementedError() + + def compute_characteristic_function(self, expr, **kwargs): + if expr == self.value: + t = Dummy("t", real=True) + return Lambda(t, self.distribution.characteristic_function(t, **kwargs)) + else: + raise NotImplementedError() + + def compute_moment_generating_function(self, expr, **kwargs): + if expr == self.value: + t = Dummy("t", real=True) + return Lambda(t, self.distribution.moment_generating_function(t, **kwargs)) + else: + raise NotImplementedError() + + def compute_quantile(self, expr, **kwargs): + if expr == self.value: + p = Dummy("p", real=True) + return Lambda(p, self.distribution.quantile(p, **kwargs)) + else: + raise NotImplementedError() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/drv_types.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/drv_types.py new file mode 100644 index 0000000000000000000000000000000000000000..84920d31c0083828efc2cd3f752d2c48f5430102 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/drv_types.py @@ -0,0 +1,849 @@ +""" + +Contains +======== +FlorySchulz +Geometric +Hermite +Logarithmic +NegativeBinomial +Poisson +Skellam +YuleSimon +Zeta +""" + + + +from sympy.concrete.summations import Sum +from sympy.core.basic import Basic +from sympy.core.function import Lambda +from sympy.core.numbers import I +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import Dummy +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import (binomial, factorial, FallingFactorial) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.bessel import besseli +from sympy.functions.special.beta_functions import beta +from sympy.functions.special.hyper import hyper +from sympy.functions.special.zeta_functions import (polylog, zeta) +from sympy.stats.drv import SingleDiscreteDistribution, SingleDiscretePSpace +from sympy.stats.rv import _value_check, is_random + + +__all__ = ['FlorySchulz', +'Geometric', +'Hermite', +'Logarithmic', +'NegativeBinomial', +'Poisson', +'Skellam', +'YuleSimon', +'Zeta' +] + + +def rv(symbol, cls, *args, **kwargs): + args = list(map(sympify, args)) + dist = cls(*args) + if kwargs.pop('check', True): + dist.check(*args) + pspace = SingleDiscretePSpace(symbol, dist) + if any(is_random(arg) for arg in args): + from sympy.stats.compound_rv import CompoundPSpace, CompoundDistribution + pspace = CompoundPSpace(symbol, CompoundDistribution(dist)) + return pspace.value + + +class DiscreteDistributionHandmade(SingleDiscreteDistribution): + _argnames = ('pdf',) + + def __new__(cls, pdf, set=S.Integers): + return Basic.__new__(cls, pdf, set) + + @property + def set(self): + return self.args[1] + + @staticmethod + def check(pdf, set): + x = Dummy('x') + val = Sum(pdf(x), (x, set._inf, set._sup)).doit() + _value_check(Eq(val, 1) != S.false, "The pdf is incorrect on the given set.") + + + +def DiscreteRV(symbol, density, set=S.Integers, **kwargs): + """ + Create a Discrete Random Variable given the following: + + Parameters + ========== + + symbol : Symbol + Represents name of the random variable. + density : Expression containing symbol + Represents probability density function. + set : set + Represents the region where the pdf is valid, by default is real line. + check : bool + If True, it will check whether the given density + integrates to 1 over the given set. If False, it + will not perform this check. Default is False. + + Examples + ======== + + >>> from sympy.stats import DiscreteRV, P, E + >>> from sympy import Rational, Symbol + >>> x = Symbol('x') + >>> n = 10 + >>> density = Rational(1, 10) + >>> X = DiscreteRV(x, density, set=set(range(n))) + >>> E(X) + 9/2 + >>> P(X>3) + 3/5 + + Returns + ======= + + RandomSymbol + + """ + set = sympify(set) + pdf = Piecewise((density, set.as_relational(symbol)), (0, True)) + pdf = Lambda(symbol, pdf) + # have a default of False while `rv` should have a default of True + kwargs['check'] = kwargs.pop('check', False) + return rv(symbol.name, DiscreteDistributionHandmade, pdf, set, **kwargs) + + +#------------------------------------------------------------------------------- +# Flory-Schulz distribution ------------------------------------------------------------ + +class FlorySchulzDistribution(SingleDiscreteDistribution): + _argnames = ('a',) + set = S.Naturals + + @staticmethod + def check(a): + _value_check((0 < a, a < 1), "a must be between 0 and 1") + + def pdf(self, k): + a = self.a + return (a**2 * k * (1 - a)**(k - 1)) + + def _characteristic_function(self, t): + a = self.a + return a**2*exp(I*t)/((1 + (a - 1)*exp(I*t))**2) + + def _moment_generating_function(self, t): + a = self.a + return a**2*exp(t)/((1 + (a - 1)*exp(t))**2) + + +def FlorySchulz(name, a): + r""" + Create a discrete random variable with a FlorySchulz distribution. + + The density of the FlorySchulz distribution is given by + + .. math:: + f(k) := (a^2) k (1 - a)^{k-1} + + Parameters + ========== + + a : A real number between 0 and 1 + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, E, variance, FlorySchulz + >>> from sympy import Symbol, S + + >>> a = S.One / 5 + >>> z = Symbol("z") + + >>> X = FlorySchulz("x", a) + + >>> density(X)(z) + (4/5)**(z - 1)*z/25 + + >>> E(X) + 9 + + >>> variance(X) + 40 + + References + ========== + + https://en.wikipedia.org/wiki/Flory%E2%80%93Schulz_distribution + """ + return rv(name, FlorySchulzDistribution, a) + + +#------------------------------------------------------------------------------- +# Geometric distribution ------------------------------------------------------------ + +class GeometricDistribution(SingleDiscreteDistribution): + _argnames = ('p',) + set = S.Naturals + + @staticmethod + def check(p): + _value_check((0 < p, p <= 1), "p must be between 0 and 1") + + def pdf(self, k): + return (1 - self.p)**(k - 1) * self.p + + def _characteristic_function(self, t): + p = self.p + return p * exp(I*t) / (1 - (1 - p)*exp(I*t)) + + def _moment_generating_function(self, t): + p = self.p + return p * exp(t) / (1 - (1 - p) * exp(t)) + + +def Geometric(name, p): + r""" + Create a discrete random variable with a Geometric distribution. + + Explanation + =========== + + The density of the Geometric distribution is given by + + .. math:: + f(k) := p (1 - p)^{k - 1} + + Parameters + ========== + + p : A probability between 0 and 1 + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Geometric, density, E, variance + >>> from sympy import Symbol, S + + >>> p = S.One / 5 + >>> z = Symbol("z") + + >>> X = Geometric("x", p) + + >>> density(X)(z) + (4/5)**(z - 1)/5 + + >>> E(X) + 5 + + >>> variance(X) + 20 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Geometric_distribution + .. [2] https://mathworld.wolfram.com/GeometricDistribution.html + + """ + return rv(name, GeometricDistribution, p) + + +#------------------------------------------------------------------------------- +# Hermite distribution --------------------------------------------------------- + + +class HermiteDistribution(SingleDiscreteDistribution): + _argnames = ('a1', 'a2') + set = S.Naturals0 + + @staticmethod + def check(a1, a2): + _value_check(a1.is_nonnegative, 'Parameter a1 must be >= 0.') + _value_check(a2.is_nonnegative, 'Parameter a2 must be >= 0.') + + def pdf(self, k): + a1, a2 = self.a1, self.a2 + term1 = exp(-(a1 + a2)) + j = Dummy("j", integer=True) + num = a1**(k - 2*j) * a2**j + den = factorial(k - 2*j) * factorial(j) + return term1 * Sum(num/den, (j, 0, k//2)).doit() + + def _moment_generating_function(self, t): + a1, a2 = self.a1, self.a2 + term1 = a1 * (exp(t) - 1) + term2 = a2 * (exp(2*t) - 1) + return exp(term1 + term2) + + def _characteristic_function(self, t): + a1, a2 = self.a1, self.a2 + term1 = a1 * (exp(I*t) - 1) + term2 = a2 * (exp(2*I*t) - 1) + return exp(term1 + term2) + +def Hermite(name, a1, a2): + r""" + Create a discrete random variable with a Hermite distribution. + + Explanation + =========== + + The density of the Hermite distribution is given by + + .. math:: + f(x):= e^{-a_1 -a_2}\sum_{j=0}^{\left \lfloor x/2 \right \rfloor} + \frac{a_{1}^{x-2j}a_{2}^{j}}{(x-2j)!j!} + + Parameters + ========== + + a1 : A Positive number greater than equal to 0. + a2 : A Positive number greater than equal to 0. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Hermite, density, E, variance + >>> from sympy import Symbol + + >>> a1 = Symbol("a1", positive=True) + >>> a2 = Symbol("a2", positive=True) + >>> x = Symbol("x") + + >>> H = Hermite("H", a1=5, a2=4) + + >>> density(H)(2) + 33*exp(-9)/2 + + >>> E(H) + 13 + + >>> variance(H) + 21 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Hermite_distribution + + """ + + return rv(name, HermiteDistribution, a1, a2) + + +#------------------------------------------------------------------------------- +# Logarithmic distribution ------------------------------------------------------------ + +class LogarithmicDistribution(SingleDiscreteDistribution): + _argnames = ('p',) + + set = S.Naturals + + @staticmethod + def check(p): + _value_check((p > 0, p < 1), "p should be between 0 and 1") + + def pdf(self, k): + p = self.p + return (-1) * p**k / (k * log(1 - p)) + + def _characteristic_function(self, t): + p = self.p + return log(1 - p * exp(I*t)) / log(1 - p) + + def _moment_generating_function(self, t): + p = self.p + return log(1 - p * exp(t)) / log(1 - p) + + +def Logarithmic(name, p): + r""" + Create a discrete random variable with a Logarithmic distribution. + + Explanation + =========== + + The density of the Logarithmic distribution is given by + + .. math:: + f(k) := \frac{-p^k}{k \ln{(1 - p)}} + + Parameters + ========== + + p : A value between 0 and 1 + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Logarithmic, density, E, variance + >>> from sympy import Symbol, S + + >>> p = S.One / 5 + >>> z = Symbol("z") + + >>> X = Logarithmic("x", p) + + >>> density(X)(z) + -1/(5**z*z*log(4/5)) + + >>> E(X) + -1/(-4*log(5) + 8*log(2)) + + >>> variance(X) + -1/((-4*log(5) + 8*log(2))*(-2*log(5) + 4*log(2))) + 1/(-64*log(2)*log(5) + 64*log(2)**2 + 16*log(5)**2) - 10/(-32*log(5) + 64*log(2)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Logarithmic_distribution + .. [2] https://mathworld.wolfram.com/LogarithmicDistribution.html + + """ + return rv(name, LogarithmicDistribution, p) + + +#------------------------------------------------------------------------------- +# Negative binomial distribution ------------------------------------------------------------ + +class NegativeBinomialDistribution(SingleDiscreteDistribution): + _argnames = ('r', 'p') + set = S.Naturals0 + + @staticmethod + def check(r, p): + _value_check(r > 0, 'r should be positive') + _value_check((p > 0, p < 1), 'p should be between 0 and 1') + + def pdf(self, k): + r = self.r + p = self.p + + return binomial(k + r - 1, k) * (1 - p)**k * p**r + + def _characteristic_function(self, t): + r = self.r + p = self.p + + return (p / (1 - (1 - p) * exp(I*t)))**r + + def _moment_generating_function(self, t): + r = self.r + p = self.p + + return (p / (1 - (1 - p) * exp(t)))**r + +def NegativeBinomial(name, r, p): + r""" + Create a discrete random variable with a Negative Binomial distribution. + + Explanation + =========== + + The density of the Negative Binomial distribution is given by + + .. math:: + f(k) := \binom{k + r - 1}{k} (1 - p)^k p^r + + Parameters + ========== + + r : A positive value + Number of successes until the experiment is stopped. + p : A value between 0 and 1 + Probability of success. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import NegativeBinomial, density, E, variance + >>> from sympy import Symbol, S + + >>> r = 5 + >>> p = S.One / 3 + >>> z = Symbol("z") + + >>> X = NegativeBinomial("x", r, p) + + >>> density(X)(z) + (2/3)**z*binomial(z + 4, z)/243 + + >>> E(X) + 10 + + >>> variance(X) + 30 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Negative_binomial_distribution + .. [2] https://mathworld.wolfram.com/NegativeBinomialDistribution.html + + """ + return rv(name, NegativeBinomialDistribution, r, p) + + +#------------------------------------------------------------------------------- +# Poisson distribution ------------------------------------------------------------ + +class PoissonDistribution(SingleDiscreteDistribution): + _argnames = ('lamda',) + + set = S.Naturals0 + + @staticmethod + def check(lamda): + _value_check(lamda > 0, "Lambda must be positive") + + def pdf(self, k): + return self.lamda**k / factorial(k) * exp(-self.lamda) + + def _characteristic_function(self, t): + return exp(self.lamda * (exp(I*t) - 1)) + + def _moment_generating_function(self, t): + return exp(self.lamda * (exp(t) - 1)) + + def expectation(self, expr, var, evaluate=True, **kwargs): + if evaluate: + if expr == var: + return self.lamda + if ( + isinstance(expr, FallingFactorial) + and expr.args[1].is_integer + and expr.args[1].is_positive + and expr.args[0] == var + ): + return self.lamda ** expr.args[1] + return super().expectation(expr, var, evaluate, **kwargs) + +def Poisson(name, lamda): + r""" + Create a discrete random variable with a Poisson distribution. + + Explanation + =========== + + The density of the Poisson distribution is given by + + .. math:: + f(k) := \frac{\lambda^{k} e^{- \lambda}}{k!} + + Parameters + ========== + + lamda : Positive number, a rate + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Poisson, density, E, variance + >>> from sympy import Symbol, simplify + + >>> rate = Symbol("lambda", positive=True) + >>> z = Symbol("z") + + >>> X = Poisson("x", rate) + + >>> density(X)(z) + lambda**z*exp(-lambda)/factorial(z) + + >>> E(X) + lambda + + >>> simplify(variance(X)) + lambda + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Poisson_distribution + .. [2] https://mathworld.wolfram.com/PoissonDistribution.html + + """ + return rv(name, PoissonDistribution, lamda) + + +# ----------------------------------------------------------------------------- +# Skellam distribution -------------------------------------------------------- + + +class SkellamDistribution(SingleDiscreteDistribution): + _argnames = ('mu1', 'mu2') + set = S.Integers + + @staticmethod + def check(mu1, mu2): + _value_check(mu1 >= 0, 'Parameter mu1 must be >= 0') + _value_check(mu2 >= 0, 'Parameter mu2 must be >= 0') + + def pdf(self, k): + (mu1, mu2) = (self.mu1, self.mu2) + term1 = exp(-(mu1 + mu2)) * (mu1 / mu2) ** (k / 2) + term2 = besseli(k, 2 * sqrt(mu1 * mu2)) + return term1 * term2 + + def _cdf(self, x): + raise NotImplementedError( + "Skellam doesn't have closed form for the CDF.") + + def _characteristic_function(self, t): + (mu1, mu2) = (self.mu1, self.mu2) + return exp(-(mu1 + mu2) + mu1 * exp(I * t) + mu2 * exp(-I * t)) + + def _moment_generating_function(self, t): + (mu1, mu2) = (self.mu1, self.mu2) + return exp(-(mu1 + mu2) + mu1 * exp(t) + mu2 * exp(-t)) + + +def Skellam(name, mu1, mu2): + r""" + Create a discrete random variable with a Skellam distribution. + + Explanation + =========== + + The Skellam is the distribution of the difference N1 - N2 + of two statistically independent random variables N1 and N2 + each Poisson-distributed with respective expected values mu1 and mu2. + + The density of the Skellam distribution is given by + + .. math:: + f(k) := e^{-(\mu_1+\mu_2)}(\frac{\mu_1}{\mu_2})^{k/2}I_k(2\sqrt{\mu_1\mu_2}) + + Parameters + ========== + + mu1 : A non-negative value + mu2 : A non-negative value + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Skellam, density, E, variance + >>> from sympy import Symbol, pprint + + >>> z = Symbol("z", integer=True) + >>> mu1 = Symbol("mu1", positive=True) + >>> mu2 = Symbol("mu2", positive=True) + >>> X = Skellam("x", mu1, mu2) + + >>> pprint(density(X)(z), use_unicode=False) + z + - + 2 + /mu1\ -mu1 - mu2 / _____ _____\ + |---| *e *besseli\z, 2*\/ mu1 *\/ mu2 / + \mu2/ + >>> E(X) + mu1 - mu2 + >>> variance(X).expand() + mu1 + mu2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Skellam_distribution + + """ + return rv(name, SkellamDistribution, mu1, mu2) + + +#------------------------------------------------------------------------------- +# Yule-Simon distribution ------------------------------------------------------------ + +class YuleSimonDistribution(SingleDiscreteDistribution): + _argnames = ('rho',) + set = S.Naturals + + @staticmethod + def check(rho): + _value_check(rho > 0, 'rho should be positive') + + def pdf(self, k): + rho = self.rho + return rho * beta(k, rho + 1) + + def _cdf(self, x): + return Piecewise((1 - floor(x) * beta(floor(x), self.rho + 1), x >= 1), (0, True)) + + def _characteristic_function(self, t): + rho = self.rho + return rho * hyper((1, 1), (rho + 2,), exp(I*t)) * exp(I*t) / (rho + 1) + + def _moment_generating_function(self, t): + rho = self.rho + return rho * hyper((1, 1), (rho + 2,), exp(t)) * exp(t) / (rho + 1) + + +def YuleSimon(name, rho): + r""" + Create a discrete random variable with a Yule-Simon distribution. + + Explanation + =========== + + The density of the Yule-Simon distribution is given by + + .. math:: + f(k) := \rho B(k, \rho + 1) + + Parameters + ========== + + rho : A positive value + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import YuleSimon, density, E, variance + >>> from sympy import Symbol, simplify + + >>> p = 5 + >>> z = Symbol("z") + + >>> X = YuleSimon("x", p) + + >>> density(X)(z) + 5*beta(z, 6) + + >>> simplify(E(X)) + 5/4 + + >>> simplify(variance(X)) + 25/48 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Yule%E2%80%93Simon_distribution + + """ + return rv(name, YuleSimonDistribution, rho) + + +#------------------------------------------------------------------------------- +# Zeta distribution ------------------------------------------------------------ + +class ZetaDistribution(SingleDiscreteDistribution): + _argnames = ('s',) + set = S.Naturals + + @staticmethod + def check(s): + _value_check(s > 1, 's should be greater than 1') + + def pdf(self, k): + s = self.s + return 1 / (k**s * zeta(s)) + + def _characteristic_function(self, t): + return polylog(self.s, exp(I*t)) / zeta(self.s) + + def _moment_generating_function(self, t): + return polylog(self.s, exp(t)) / zeta(self.s) + + +def Zeta(name, s): + r""" + Create a discrete random variable with a Zeta distribution. + + Explanation + =========== + + The density of the Zeta distribution is given by + + .. math:: + f(k) := \frac{1}{k^s \zeta{(s)}} + + Parameters + ========== + + s : A value greater than 1 + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import Zeta, density, E, variance + >>> from sympy import Symbol + + >>> s = 5 + >>> z = Symbol("z") + + >>> X = Zeta("x", s) + + >>> density(X)(z) + 1/(z**5*zeta(5)) + + >>> E(X) + pi**4/(90*zeta(5)) + + >>> variance(X) + -pi**8/(8100*zeta(5)**2) + zeta(3)/zeta(5) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Zeta_distribution + + """ + return rv(name, ZetaDistribution, s) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/error_prop.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/error_prop.py new file mode 100644 index 0000000000000000000000000000000000000000..e6cacb894307fe60cbf096c7760e6ed57f385a91 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/error_prop.py @@ -0,0 +1,100 @@ +"""Tools for arithmetic error propagation.""" + +from itertools import repeat, combinations + +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.power import Pow +from sympy.core.singleton import S +from sympy.core.symbol import Symbol +from sympy.functions.elementary.exponential import exp +from sympy.simplify.simplify import simplify +from sympy.stats.symbolic_probability import RandomSymbol, Variance, Covariance +from sympy.stats.rv import is_random + +_arg0_or_var = lambda var: var.args[0] if len(var.args) > 0 else var + + +def variance_prop(expr, consts=(), include_covar=False): + r"""Symbolically propagates variance (`\sigma^2`) for expressions. + This is computed as as seen in [1]_. + + Parameters + ========== + + expr : Expr + A SymPy expression to compute the variance for. + consts : sequence of Symbols, optional + Represents symbols that are known constants in the expr, + and thus have zero variance. All symbols not in consts are + assumed to be variant. + include_covar : bool, optional + Flag for whether or not to include covariances, default=False. + + Returns + ======= + + var_expr : Expr + An expression for the total variance of the expr. + The variance for the original symbols (e.g. x) are represented + via instance of the Variance symbol (e.g. Variance(x)). + + Examples + ======== + + >>> from sympy import symbols, exp + >>> from sympy.stats.error_prop import variance_prop + >>> x, y = symbols('x y') + + >>> variance_prop(x + y) + Variance(x) + Variance(y) + + >>> variance_prop(x * y) + x**2*Variance(y) + y**2*Variance(x) + + >>> variance_prop(exp(2*x)) + 4*exp(4*x)*Variance(x) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Propagation_of_uncertainty + + """ + args = expr.args + if len(args) == 0: + if expr in consts: + return S.Zero + elif is_random(expr): + return Variance(expr).doit() + elif isinstance(expr, Symbol): + return Variance(RandomSymbol(expr)).doit() + else: + return S.Zero + nargs = len(args) + var_args = list(map(variance_prop, args, repeat(consts, nargs), + repeat(include_covar, nargs))) + if isinstance(expr, Add): + var_expr = Add(*var_args) + if include_covar: + terms = [2 * Covariance(_arg0_or_var(x), _arg0_or_var(y)).expand() \ + for x, y in combinations(var_args, 2)] + var_expr += Add(*terms) + elif isinstance(expr, Mul): + terms = [v/a**2 for a, v in zip(args, var_args)] + var_expr = simplify(expr**2 * Add(*terms)) + if include_covar: + terms = [2*Covariance(_arg0_or_var(x), _arg0_or_var(y)).expand()/(a*b) \ + for (a, b), (x, y) in zip(combinations(args, 2), + combinations(var_args, 2))] + var_expr += Add(*terms) + elif isinstance(expr, Pow): + b = args[1] + v = var_args[0] * (expr * b / args[0])**2 + var_expr = simplify(v) + elif isinstance(expr, exp): + var_expr = simplify(var_args[0] * expr**2) + else: + # unknown how to proceed, return variance of whole expr. + var_expr = Variance(expr) + return var_expr diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/frv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/frv.py new file mode 100644 index 0000000000000000000000000000000000000000..498d7e4006b2b8db306a0905ed67578021e220a8 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/frv.py @@ -0,0 +1,512 @@ +""" +Finite Discrete Random Variables Module + +See Also +======== +sympy.stats.frv_types +sympy.stats.rv +sympy.stats.crv +""" +from itertools import product + +from sympy.concrete.summations import Sum +from sympy.core.basic import Basic +from sympy.core.cache import cacheit +from sympy.core.function import Lambda +from sympy.core.mul import Mul +from sympy.core.numbers import (I, nan) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol) +from sympy.core.sympify import sympify +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.piecewise import Piecewise +from sympy.logic.boolalg import (And, Or) +from sympy.sets.sets import Intersection +from sympy.core.containers import Dict +from sympy.core.logic import Logic +from sympy.core.relational import Relational +from sympy.core.sympify import _sympify +from sympy.sets.sets import FiniteSet +from sympy.stats.rv import (RandomDomain, ProductDomain, ConditionalDomain, + PSpace, IndependentProductPSpace, SinglePSpace, random_symbols, + sumsets, rv_subs, NamedArgsMixin, Density, Distribution) + + +class FiniteDensity(dict): + """ + A domain with Finite Density. + """ + def __call__(self, item): + """ + Make instance of a class callable. + + If item belongs to current instance of a class, return it. + + Otherwise, return 0. + """ + item = sympify(item) + if item in self: + return self[item] + else: + return 0 + + @property + def dict(self): + """ + Return item as dictionary. + """ + return dict(self) + +class FiniteDomain(RandomDomain): + """ + A domain with discrete finite support + + Represented using a FiniteSet. + """ + is_Finite = True + + @property + def symbols(self): + return FiniteSet(sym for sym, val in self.elements) + + @property + def elements(self): + return self.args[0] + + @property + def dict(self): + return FiniteSet(*[Dict(dict(el)) for el in self.elements]) + + def __contains__(self, other): + return other in self.elements + + def __iter__(self): + return self.elements.__iter__() + + def as_boolean(self): + return Or(*[And(*[Eq(sym, val) for sym, val in item]) for item in self]) + + +class SingleFiniteDomain(FiniteDomain): + """ + A FiniteDomain over a single symbol/set + + Example: The possibilities of a *single* die roll. + """ + + def __new__(cls, symbol, set): + if not isinstance(set, FiniteSet) and \ + not isinstance(set, Intersection): + set = FiniteSet(*set) + return Basic.__new__(cls, symbol, set) + + @property + def symbol(self): + return self.args[0] + + @property + def symbols(self): + return FiniteSet(self.symbol) + + @property + def set(self): + return self.args[1] + + @property + def elements(self): + return FiniteSet(*[frozenset(((self.symbol, elem), )) for elem in self.set]) + + def __iter__(self): + return (frozenset(((self.symbol, elem),)) for elem in self.set) + + def __contains__(self, other): + sym, val = tuple(other)[0] + return sym == self.symbol and val in self.set + + +class ProductFiniteDomain(ProductDomain, FiniteDomain): + """ + A Finite domain consisting of several other FiniteDomains + + Example: The possibilities of the rolls of three independent dice + """ + + def __iter__(self): + proditer = product(*self.domains) + return (sumsets(items) for items in proditer) + + @property + def elements(self): + return FiniteSet(*self) + + +class ConditionalFiniteDomain(ConditionalDomain, ProductFiniteDomain): + """ + A FiniteDomain that has been restricted by a condition + + Example: The possibilities of a die roll under the condition that the + roll is even. + """ + + def __new__(cls, domain, condition): + """ + Create a new instance of ConditionalFiniteDomain class + """ + if condition is True: + return domain + cond = rv_subs(condition) + return Basic.__new__(cls, domain, cond) + + def _test(self, elem): + """ + Test the value. If value is boolean, return it. If value is equality + relational (two objects are equal), return it with left-hand side + being equal to right-hand side. Otherwise, raise ValueError exception. + """ + val = self.condition.xreplace(dict(elem)) + if val in [True, False]: + return val + elif val.is_Equality: + return val.lhs == val.rhs + raise ValueError("Undecidable if %s" % str(val)) + + def __contains__(self, other): + return other in self.fulldomain and self._test(other) + + def __iter__(self): + return (elem for elem in self.fulldomain if self._test(elem)) + + @property + def set(self): + if isinstance(self.fulldomain, SingleFiniteDomain): + return FiniteSet(*[elem for elem in self.fulldomain.set + if frozenset(((self.fulldomain.symbol, elem),)) in self]) + else: + raise NotImplementedError( + "Not implemented on multi-dimensional conditional domain") + + def as_boolean(self): + return FiniteDomain.as_boolean(self) + + +class SingleFiniteDistribution(Distribution, NamedArgsMixin): + def __new__(cls, *args): + args = list(map(sympify, args)) + return Basic.__new__(cls, *args) + + @staticmethod + def check(*args): + pass + + @property # type: ignore + @cacheit + def dict(self): + if self.is_symbolic: + return Density(self) + return {k: self.pmf(k) for k in self.set} + + def pmf(self, *args): # to be overridden by specific distribution + raise NotImplementedError() + + @property + def set(self): # to be overridden by specific distribution + raise NotImplementedError() + + values = property(lambda self: self.dict.values) + items = property(lambda self: self.dict.items) + is_symbolic = property(lambda self: False) + __iter__ = property(lambda self: self.dict.__iter__) + __getitem__ = property(lambda self: self.dict.__getitem__) + + def __call__(self, *args): + return self.pmf(*args) + + def __contains__(self, other): + return other in self.set + + +#============================================= +#========= Probability Space =============== +#============================================= + + +class FinitePSpace(PSpace): + """ + A Finite Probability Space + + Represents the probabilities of a finite number of events. + """ + is_Finite = True + + def __new__(cls, domain, density): + density = {sympify(key): sympify(val) + for key, val in density.items()} + public_density = Dict(density) + + obj = PSpace.__new__(cls, domain, public_density) + obj._density = density + return obj + + def prob_of(self, elem): + elem = sympify(elem) + density = self._density + if isinstance(list(density.keys())[0], FiniteSet): + return density.get(elem, S.Zero) + return density.get(tuple(elem)[0][1], S.Zero) + + def where(self, condition): + assert all(r.symbol in self.symbols for r in random_symbols(condition)) + return ConditionalFiniteDomain(self.domain, condition) + + def compute_density(self, expr): + expr = rv_subs(expr, self.values) + d = FiniteDensity() + for elem in self.domain: + val = expr.xreplace(dict(elem)) + prob = self.prob_of(elem) + d[val] = d.get(val, S.Zero) + prob + return d + + @cacheit + def compute_cdf(self, expr): + d = self.compute_density(expr) + cum_prob = S.Zero + cdf = [] + for key in sorted(d): + prob = d[key] + cum_prob += prob + cdf.append((key, cum_prob)) + + return dict(cdf) + + @cacheit + def sorted_cdf(self, expr, python_float=False): + cdf = self.compute_cdf(expr) + items = list(cdf.items()) + sorted_items = sorted(items, key=lambda val_cumprob: val_cumprob[1]) + if python_float: + sorted_items = [(v, float(cum_prob)) + for v, cum_prob in sorted_items] + return sorted_items + + @cacheit + def compute_characteristic_function(self, expr): + d = self.compute_density(expr) + t = Dummy('t', real=True) + + return Lambda(t, sum(exp(I*k*t)*v for k,v in d.items())) + + @cacheit + def compute_moment_generating_function(self, expr): + d = self.compute_density(expr) + t = Dummy('t', real=True) + + return Lambda(t, sum(exp(k*t)*v for k,v in d.items())) + + def compute_expectation(self, expr, rvs=None, **kwargs): + rvs = rvs or self.values + expr = rv_subs(expr, rvs) + probs = [self.prob_of(elem) for elem in self.domain] + if isinstance(expr, (Logic, Relational)): + parse_domain = [tuple(elem)[0][1] for elem in self.domain] + bools = [expr.xreplace(dict(elem)) for elem in self.domain] + else: + parse_domain = [expr.xreplace(dict(elem)) for elem in self.domain] + bools = [True for elem in self.domain] + return sum(Piecewise((prob * elem, blv), (S.Zero, True)) + for prob, elem, blv in zip(probs, parse_domain, bools)) + + def compute_quantile(self, expr): + cdf = self.compute_cdf(expr) + p = Dummy('p', real=True) + set = ((nan, (p < 0) | (p > 1)),) + for key, value in cdf.items(): + set = set + ((key, p <= value), ) + return Lambda(p, Piecewise(*set)) + + def probability(self, condition): + cond_symbols = frozenset(rs.symbol for rs in random_symbols(condition)) + cond = rv_subs(condition) + if not cond_symbols.issubset(self.symbols): + raise ValueError("Cannot compare foreign random symbols, %s" + %(str(cond_symbols - self.symbols))) + if isinstance(condition, Relational) and \ + (not cond.free_symbols.issubset(self.domain.free_symbols)): + rv = condition.lhs if isinstance(condition.rhs, Symbol) else condition.rhs + return sum(Piecewise( + (self.prob_of(elem), condition.subs(rv, list(elem)[0][1])), + (S.Zero, True)) for elem in self.domain) + return sympify(sum(self.prob_of(elem) for elem in self.where(condition))) + + def conditional_space(self, condition): + domain = self.where(condition) + prob = self.probability(condition) + density = {key: val / prob + for key, val in self._density.items() if domain._test(key)} + return FinitePSpace(domain, density) + + def sample(self, size=(), library='scipy', seed=None): + """ + Internal sample method + + Returns dictionary mapping RandomSymbol to realization value. + """ + return {self.value: self.distribution.sample(size, library, seed)} + + +class SingleFinitePSpace(SinglePSpace, FinitePSpace): + """ + A single finite probability space + + Represents the probabilities of a set of random events that can be + attributed to a single variable/symbol. + + This class is implemented by many of the standard FiniteRV types such as + Die, Bernoulli, Coin, etc.... + """ + @property + def domain(self): + return SingleFiniteDomain(self.symbol, self.distribution.set) + + @property + def _is_symbolic(self): + """ + Helper property to check if the distribution + of the random variable is having symbolic + dimension. + """ + return self.distribution.is_symbolic + + @property + def distribution(self): + return self.args[1] + + def pmf(self, expr): + return self.distribution.pmf(expr) + + @property # type: ignore + @cacheit + def _density(self): + return {FiniteSet((self.symbol, val)): prob + for val, prob in self.distribution.dict.items()} + + @cacheit + def compute_characteristic_function(self, expr): + if self._is_symbolic: + d = self.compute_density(expr) + t = Dummy('t', real=True) + ki = Dummy('ki') + return Lambda(t, Sum(d(ki)*exp(I*ki*t), (ki, self.args[1].low, self.args[1].high))) + expr = rv_subs(expr, self.values) + return FinitePSpace(self.domain, self.distribution).compute_characteristic_function(expr) + + @cacheit + def compute_moment_generating_function(self, expr): + if self._is_symbolic: + d = self.compute_density(expr) + t = Dummy('t', real=True) + ki = Dummy('ki') + return Lambda(t, Sum(d(ki)*exp(ki*t), (ki, self.args[1].low, self.args[1].high))) + expr = rv_subs(expr, self.values) + return FinitePSpace(self.domain, self.distribution).compute_moment_generating_function(expr) + + def compute_quantile(self, expr): + if self._is_symbolic: + raise NotImplementedError("Computing quantile for random variables " + "with symbolic dimension because the bounds of searching the required " + "value is undetermined.") + expr = rv_subs(expr, self.values) + return FinitePSpace(self.domain, self.distribution).compute_quantile(expr) + + def compute_density(self, expr): + if self._is_symbolic: + rv = list(random_symbols(expr))[0] + k = Dummy('k', integer=True) + cond = True if not isinstance(expr, (Relational, Logic)) \ + else expr.subs(rv, k) + return Lambda(k, + Piecewise((self.pmf(k), And(k >= self.args[1].low, + k <= self.args[1].high, cond)), (S.Zero, True))) + expr = rv_subs(expr, self.values) + return FinitePSpace(self.domain, self.distribution).compute_density(expr) + + def compute_cdf(self, expr): + if self._is_symbolic: + d = self.compute_density(expr) + k = Dummy('k') + ki = Dummy('ki') + return Lambda(k, Sum(d(ki), (ki, self.args[1].low, k))) + expr = rv_subs(expr, self.values) + return FinitePSpace(self.domain, self.distribution).compute_cdf(expr) + + def compute_expectation(self, expr, rvs=None, **kwargs): + if self._is_symbolic: + rv = random_symbols(expr)[0] + k = Dummy('k', integer=True) + expr = expr.subs(rv, k) + cond = True if not isinstance(expr, (Relational, Logic)) \ + else expr + func = self.pmf(k) * k if cond != True else self.pmf(k) * expr + return Sum(Piecewise((func, cond), (S.Zero, True)), + (k, self.distribution.low, self.distribution.high)).doit() + + expr = _sympify(expr) + expr = rv_subs(expr, rvs) + return FinitePSpace(self.domain, self.distribution).compute_expectation(expr, rvs, **kwargs) + + def probability(self, condition): + if self._is_symbolic: + #TODO: Implement the mechanism for handling queries for symbolic sized distributions. + raise NotImplementedError("Currently, probability queries are not " + "supported for random variables with symbolic sized distributions.") + condition = rv_subs(condition) + return FinitePSpace(self.domain, self.distribution).probability(condition) + + def conditional_space(self, condition): + """ + This method is used for transferring the + computation to probability method because + conditional space of random variables with + symbolic dimensions is currently not possible. + """ + if self._is_symbolic: + self + domain = self.where(condition) + prob = self.probability(condition) + density = {key: val / prob + for key, val in self._density.items() if domain._test(key)} + return FinitePSpace(domain, density) + + +class ProductFinitePSpace(IndependentProductPSpace, FinitePSpace): + """ + A collection of several independent finite probability spaces + """ + @property + def domain(self): + return ProductFiniteDomain(*[space.domain for space in self.spaces]) + + @property # type: ignore + @cacheit + def _density(self): + proditer = product(*[iter(space._density.items()) + for space in self.spaces]) + d = {} + for items in proditer: + elems, probs = list(zip(*items)) + elem = sumsets(elems) + prob = Mul(*probs) + d[elem] = d.get(elem, S.Zero) + prob + return Dict(d) + + @property # type: ignore + @cacheit + def density(self): + return Dict(self._density) + + def probability(self, condition): + return FinitePSpace.probability(self, condition) + + def compute_density(self, expr): + return FinitePSpace.compute_density(self, expr) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/frv_types.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/frv_types.py new file mode 100644 index 0000000000000000000000000000000000000000..bde656c219791c287ff445d5d215e3759271e923 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/frv_types.py @@ -0,0 +1,873 @@ +""" +Finite Discrete Random Variables - Prebuilt variable types + +Contains +======== +FiniteRV +DiscreteUniform +Die +Bernoulli +Coin +Binomial +BetaBinomial +Hypergeometric +Rademacher +IdealSoliton +RobustSoliton +""" + + +from sympy.core.cache import cacheit +from sympy.core.function import Lambda +from sympy.core.numbers import (Integer, Rational) +from sympy.core.relational import (Eq, Ge, Gt, Le, Lt) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol) +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import binomial +from sympy.functions.elementary.exponential import log +from sympy.functions.elementary.piecewise import Piecewise +from sympy.logic.boolalg import Or +from sympy.sets.contains import Contains +from sympy.sets.fancysets import Range +from sympy.sets.sets import (Intersection, Interval) +from sympy.functions.special.beta_functions import beta as beta_fn +from sympy.stats.frv import (SingleFiniteDistribution, + SingleFinitePSpace) +from sympy.stats.rv import _value_check, Density, is_random +from sympy.utilities.iterables import multiset +from sympy.utilities.misc import filldedent + + +__all__ = ['FiniteRV', +'DiscreteUniform', +'Die', +'Bernoulli', +'Coin', +'Binomial', +'BetaBinomial', +'Hypergeometric', +'Rademacher', +'IdealSoliton', +'RobustSoliton', +] + +def rv(name, cls, *args, **kwargs): + args = list(map(sympify, args)) + dist = cls(*args) + if kwargs.pop('check', True): + dist.check(*args) + pspace = SingleFinitePSpace(name, dist) + if any(is_random(arg) for arg in args): + from sympy.stats.compound_rv import CompoundPSpace, CompoundDistribution + pspace = CompoundPSpace(name, CompoundDistribution(dist)) + return pspace.value + +class FiniteDistributionHandmade(SingleFiniteDistribution): + + @property + def dict(self): + return self.args[0] + + def pmf(self, x): + x = Symbol('x') + return Lambda(x, Piecewise(*( + [(v, Eq(k, x)) for k, v in self.dict.items()] + [(S.Zero, True)]))) + + @property + def set(self): + return set(self.dict.keys()) + + @staticmethod + def check(density): + for p in density.values(): + _value_check((p >= 0, p <= 1), + "Probability at a point must be between 0 and 1.") + val = sum(density.values()) + _value_check(Eq(val, 1) != S.false, "Total Probability must be 1.") + +def FiniteRV(name, density, **kwargs): + r""" + Create a Finite Random Variable given a dict representing the density. + + Parameters + ========== + + name : Symbol + Represents name of the random variable. + density : dict + Dictionary containing the pdf of finite distribution + check : bool + If True, it will check whether the given density + integrates to 1 over the given set. If False, it + will not perform this check. Default is False. + + Examples + ======== + + >>> from sympy.stats import FiniteRV, P, E + + >>> density = {0: .1, 1: .2, 2: .3, 3: .4} + >>> X = FiniteRV('X', density) + + >>> E(X) + 2.00000000000000 + >>> P(X >= 2) + 0.700000000000000 + + Returns + ======= + + RandomSymbol + + """ + # have a default of False while `rv` should have a default of True + kwargs['check'] = kwargs.pop('check', False) + return rv(name, FiniteDistributionHandmade, density, **kwargs) + +class DiscreteUniformDistribution(SingleFiniteDistribution): + + @staticmethod + def check(*args): + # not using _value_check since there is a + # suggestion for the user + if len(set(args)) != len(args): + weights = multiset(args) + n = Integer(len(args)) + for k in weights: + weights[k] /= n + raise ValueError(filldedent(""" + Repeated args detected but set expected. For a + distribution having different weights for each + item use the following:""") + ( + '\nS("FiniteRV(%s, %s)")' % ("'X'", weights))) + + @property + def p(self): + return Rational(1, len(self.args)) + + @property # type: ignore + @cacheit + def dict(self): + return dict.fromkeys(self.set, self.p) + + @property + def set(self): + return set(self.args) + + def pmf(self, x): + if x in self.args: + return self.p + else: + return S.Zero + + +def DiscreteUniform(name, items): + r""" + Create a Finite Random Variable representing a uniform distribution over + the input set. + + Parameters + ========== + + items : list/tuple + Items over which Uniform distribution is to be made + + Examples + ======== + + >>> from sympy.stats import DiscreteUniform, density + >>> from sympy import symbols + + >>> X = DiscreteUniform('X', symbols('a b c')) # equally likely over a, b, c + >>> density(X).dict + {a: 1/3, b: 1/3, c: 1/3} + + >>> Y = DiscreteUniform('Y', list(range(5))) # distribution over a range + >>> density(Y).dict + {0: 1/5, 1: 1/5, 2: 1/5, 3: 1/5, 4: 1/5} + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Discrete_uniform_distribution + .. [2] https://mathworld.wolfram.com/DiscreteUniformDistribution.html + + """ + return rv(name, DiscreteUniformDistribution, *items) + + +class DieDistribution(SingleFiniteDistribution): + _argnames = ('sides',) + + @staticmethod + def check(sides): + _value_check((sides.is_positive, sides.is_integer), + "number of sides must be a positive integer.") + + @property + def is_symbolic(self): + return not self.sides.is_number + + @property + def high(self): + return self.sides + + @property + def low(self): + return S.One + + @property + def set(self): + if self.is_symbolic: + return Intersection(S.Naturals0, Interval(0, self.sides)) + return set(map(Integer, range(1, self.sides + 1))) + + def pmf(self, x): + x = sympify(x) + if not (x.is_number or x.is_Symbol or is_random(x)): + raise ValueError("'x' expected as an argument of type 'number', 'Symbol', or " + "'RandomSymbol' not %s" % (type(x))) + cond = Ge(x, 1) & Le(x, self.sides) & Contains(x, S.Integers) + return Piecewise((S.One/self.sides, cond), (S.Zero, True)) + +def Die(name, sides=6): + r""" + Create a Finite Random Variable representing a fair die. + + Parameters + ========== + + sides : Integer + Represents the number of sides of the Die, by default is 6 + + Examples + ======== + + >>> from sympy.stats import Die, density + >>> from sympy import Symbol + + >>> D6 = Die('D6', 6) # Six sided Die + >>> density(D6).dict + {1: 1/6, 2: 1/6, 3: 1/6, 4: 1/6, 5: 1/6, 6: 1/6} + + >>> D4 = Die('D4', 4) # Four sided Die + >>> density(D4).dict + {1: 1/4, 2: 1/4, 3: 1/4, 4: 1/4} + + >>> n = Symbol('n', positive=True, integer=True) + >>> Dn = Die('Dn', n) # n sided Die + >>> density(Dn).dict + Density(DieDistribution(n)) + >>> density(Dn).dict.subs(n, 4).doit() + {1: 1/4, 2: 1/4, 3: 1/4, 4: 1/4} + + Returns + ======= + + RandomSymbol + """ + + return rv(name, DieDistribution, sides) + + +class BernoulliDistribution(SingleFiniteDistribution): + _argnames = ('p', 'succ', 'fail') + + @staticmethod + def check(p, succ, fail): + _value_check((p >= 0, p <= 1), + "p should be in range [0, 1].") + + @property + def set(self): + return {self.succ, self.fail} + + def pmf(self, x): + if isinstance(self.succ, Symbol) and isinstance(self.fail, Symbol): + return Piecewise((self.p, x == self.succ), + (1 - self.p, x == self.fail), + (S.Zero, True)) + return Piecewise((self.p, Eq(x, self.succ)), + (1 - self.p, Eq(x, self.fail)), + (S.Zero, True)) + + +def Bernoulli(name, p, succ=1, fail=0): + r""" + Create a Finite Random Variable representing a Bernoulli process. + + Parameters + ========== + + p : Rational number between 0 and 1 + Represents probability of success + succ : Integer/symbol/string + Represents event of success + fail : Integer/symbol/string + Represents event of failure + + Examples + ======== + + >>> from sympy.stats import Bernoulli, density + >>> from sympy import S + + >>> X = Bernoulli('X', S(3)/4) # 1-0 Bernoulli variable, probability = 3/4 + >>> density(X).dict + {0: 1/4, 1: 3/4} + + >>> X = Bernoulli('X', S.Half, 'Heads', 'Tails') # A fair coin toss + >>> density(X).dict + {Heads: 1/2, Tails: 1/2} + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Bernoulli_distribution + .. [2] https://mathworld.wolfram.com/BernoulliDistribution.html + + """ + + return rv(name, BernoulliDistribution, p, succ, fail) + + +def Coin(name, p=S.Half): + r""" + Create a Finite Random Variable representing a Coin toss. + + This is an equivalent of a Bernoulli random variable with + "H" and "T" as success and failure events respectively. + + Parameters + ========== + + p : Rational Number between 0 and 1 + Represents probability of getting "Heads", by default is Half + + Examples + ======== + + >>> from sympy.stats import Coin, density + >>> from sympy import Rational + + >>> C = Coin('C') # A fair coin toss + >>> density(C).dict + {H: 1/2, T: 1/2} + + >>> C2 = Coin('C2', Rational(3, 5)) # An unfair coin + >>> density(C2).dict + {H: 3/5, T: 2/5} + + Returns + ======= + + RandomSymbol + + See Also + ======== + + sympy.stats.Binomial + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Coin_flipping + + """ + return rv(name, BernoulliDistribution, p, 'H', 'T') + + +class BinomialDistribution(SingleFiniteDistribution): + _argnames = ('n', 'p', 'succ', 'fail') + + @staticmethod + def check(n, p, succ, fail): + _value_check((n.is_integer, n.is_nonnegative), + "'n' must be nonnegative integer.") + _value_check((p <= 1, p >= 0), + "p should be in range [0, 1].") + + @property + def high(self): + return self.n + + @property + def low(self): + return S.Zero + + @property + def is_symbolic(self): + return not self.n.is_number + + @property + def set(self): + if self.is_symbolic: + return Intersection(S.Naturals0, Interval(0, self.n)) + return set(self.dict.keys()) + + def pmf(self, x): + n, p = self.n, self.p + x = sympify(x) + if not (x.is_number or x.is_Symbol or is_random(x)): + raise ValueError("'x' expected as an argument of type 'number', 'Symbol', or " + "'RandomSymbol' not %s" % (type(x))) + cond = Ge(x, 0) & Le(x, n) & Contains(x, S.Integers) + return Piecewise((binomial(n, x) * p**x * (1 - p)**(n - x), cond), (S.Zero, True)) + + @property # type: ignore + @cacheit + def dict(self): + if self.is_symbolic: + return Density(self) + return {k*self.succ + (self.n-k)*self.fail: self.pmf(k) + for k in range(0, self.n + 1)} + + +def Binomial(name, n, p, succ=1, fail=0): + r""" + Create a Finite Random Variable representing a binomial distribution. + + Parameters + ========== + + n : Positive Integer + Represents number of trials + p : Rational Number between 0 and 1 + Represents probability of success + succ : Integer/symbol/string + Represents event of success, by default is 1 + fail : Integer/symbol/string + Represents event of failure, by default is 0 + + Examples + ======== + + >>> from sympy.stats import Binomial, density + >>> from sympy import S, Symbol + + >>> X = Binomial('X', 4, S.Half) # Four "coin flips" + >>> density(X).dict + {0: 1/16, 1: 1/4, 2: 3/8, 3: 1/4, 4: 1/16} + + >>> n = Symbol('n', positive=True, integer=True) + >>> p = Symbol('p', positive=True) + >>> X = Binomial('X', n, S.Half) # n "coin flips" + >>> density(X).dict + Density(BinomialDistribution(n, 1/2, 1, 0)) + >>> density(X).dict.subs(n, 4).doit() + {0: 1/16, 1: 1/4, 2: 3/8, 3: 1/4, 4: 1/16} + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Binomial_distribution + .. [2] https://mathworld.wolfram.com/BinomialDistribution.html + + """ + + return rv(name, BinomialDistribution, n, p, succ, fail) + +#------------------------------------------------------------------------------- +# Beta-binomial distribution ---------------------------------------------------------- + +class BetaBinomialDistribution(SingleFiniteDistribution): + _argnames = ('n', 'alpha', 'beta') + + @staticmethod + def check(n, alpha, beta): + _value_check((n.is_integer, n.is_nonnegative), + "'n' must be nonnegative integer. n = %s." % str(n)) + _value_check((alpha > 0), + "'alpha' must be: alpha > 0 . alpha = %s" % str(alpha)) + _value_check((beta > 0), + "'beta' must be: beta > 0 . beta = %s" % str(beta)) + + @property + def high(self): + return self.n + + @property + def low(self): + return S.Zero + + @property + def is_symbolic(self): + return not self.n.is_number + + @property + def set(self): + if self.is_symbolic: + return Intersection(S.Naturals0, Interval(0, self.n)) + return set(map(Integer, range(self.n + 1))) + + def pmf(self, k): + n, a, b = self.n, self.alpha, self.beta + return binomial(n, k) * beta_fn(k + a, n - k + b) / beta_fn(a, b) + + +def BetaBinomial(name, n, alpha, beta): + r""" + Create a Finite Random Variable representing a Beta-binomial distribution. + + Parameters + ========== + + n : Positive Integer + Represents number of trials + alpha : Real positive number + beta : Real positive number + + Examples + ======== + + >>> from sympy.stats import BetaBinomial, density + + >>> X = BetaBinomial('X', 2, 1, 1) + >>> density(X).dict + {0: 1/3, 1: 2*beta(2, 2), 2: 1/3} + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Beta-binomial_distribution + .. [2] https://mathworld.wolfram.com/BetaBinomialDistribution.html + + """ + + return rv(name, BetaBinomialDistribution, n, alpha, beta) + + +class HypergeometricDistribution(SingleFiniteDistribution): + _argnames = ('N', 'm', 'n') + + @staticmethod + def check(n, N, m): + _value_check((N.is_integer, N.is_nonnegative), + "'N' must be nonnegative integer. N = %s." % str(N)) + _value_check((n.is_integer, n.is_nonnegative), + "'n' must be nonnegative integer. n = %s." % str(n)) + _value_check((m.is_integer, m.is_nonnegative), + "'m' must be nonnegative integer. m = %s." % str(m)) + + @property + def is_symbolic(self): + return not all(x.is_number for x in (self.N, self.m, self.n)) + + @property + def high(self): + return Piecewise((self.n, Lt(self.n, self.m) != False), (self.m, True)) + + @property + def low(self): + return Piecewise((0, Gt(0, self.n + self.m - self.N) != False), (self.n + self.m - self.N, True)) + + @property + def set(self): + N, m, n = self.N, self.m, self.n + if self.is_symbolic: + return Intersection(S.Naturals0, Interval(self.low, self.high)) + return set(range(max(0, n + m - N), min(n, m) + 1)) + + def pmf(self, k): + N, m, n = self.N, self.m, self.n + return S(binomial(m, k) * binomial(N - m, n - k))/binomial(N, n) + + +def Hypergeometric(name, N, m, n): + r""" + Create a Finite Random Variable representing a hypergeometric distribution. + + Parameters + ========== + + N : Positive Integer + Represents finite population of size N. + m : Positive Integer + Represents number of trials with required feature. + n : Positive Integer + Represents numbers of draws. + + + Examples + ======== + + >>> from sympy.stats import Hypergeometric, density + + >>> X = Hypergeometric('X', 10, 5, 3) # 10 marbles, 5 white (success), 3 draws + >>> density(X).dict + {0: 1/12, 1: 5/12, 2: 5/12, 3: 1/12} + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Hypergeometric_distribution + .. [2] https://mathworld.wolfram.com/HypergeometricDistribution.html + + """ + return rv(name, HypergeometricDistribution, N, m, n) + + +class RademacherDistribution(SingleFiniteDistribution): + + @property + def set(self): + return {-1, 1} + + @property + def pmf(self): + k = Dummy('k') + return Lambda(k, Piecewise((S.Half, Or(Eq(k, -1), Eq(k, 1))), (S.Zero, True))) + +def Rademacher(name): + r""" + Create a Finite Random Variable representing a Rademacher distribution. + + Examples + ======== + + >>> from sympy.stats import Rademacher, density + + >>> X = Rademacher('X') + >>> density(X).dict + {-1: 1/2, 1: 1/2} + + Returns + ======= + + RandomSymbol + + See Also + ======== + + sympy.stats.Bernoulli + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Rademacher_distribution + + """ + return rv(name, RademacherDistribution) + +class IdealSolitonDistribution(SingleFiniteDistribution): + _argnames = ('k',) + + @staticmethod + def check(k): + _value_check(k.is_integer and k.is_positive, + "'k' must be a positive integer.") + + @property + def low(self): + return S.One + + @property + def high(self): + return self.k + + @property + def set(self): + return set(map(Integer, range(1, self.k + 1))) + + @property # type: ignore + @cacheit + def dict(self): + if self.k.is_Symbol: + return Density(self) + d = {1: Rational(1, self.k)} + d.update({i: Rational(1, i*(i - 1)) for i in range(2, self.k + 1)}) + return d + + def pmf(self, x): + x = sympify(x) + if not (x.is_number or x.is_Symbol or is_random(x)): + raise ValueError("'x' expected as an argument of type 'number', 'Symbol', or " + "'RandomSymbol' not %s" % (type(x))) + cond1 = Eq(x, 1) & x.is_integer + cond2 = Ge(x, 1) & Le(x, self.k) & x.is_integer + return Piecewise((1/self.k, cond1), (1/(x*(x - 1)), cond2), (S.Zero, True)) + +def IdealSoliton(name, k): + r""" + Create a Finite Random Variable of Ideal Soliton Distribution + + Parameters + ========== + + k : Positive Integer + Represents the number of input symbols in an LT (Luby Transform) code. + + Examples + ======== + + >>> from sympy.stats import IdealSoliton, density, P, E + >>> sol = IdealSoliton('sol', 5) + >>> density(sol).dict + {1: 1/5, 2: 1/2, 3: 1/6, 4: 1/12, 5: 1/20} + >>> density(sol).set + {1, 2, 3, 4, 5} + + >>> from sympy import Symbol + >>> k = Symbol('k', positive=True, integer=True) + >>> sol = IdealSoliton('sol', k) + >>> density(sol).dict + Density(IdealSolitonDistribution(k)) + >>> density(sol).dict.subs(k, 10).doit() + {1: 1/10, 2: 1/2, 3: 1/6, 4: 1/12, 5: 1/20, 6: 1/30, 7: 1/42, 8: 1/56, 9: 1/72, 10: 1/90} + + >>> E(sol.subs(k, 10)) + 7381/2520 + + >>> P(sol.subs(k, 4) > 2) + 1/4 + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Soliton_distribution#Ideal_distribution + .. [2] https://pages.cs.wisc.edu/~suman/courses/740/papers/luby02lt.pdf + + """ + return rv(name, IdealSolitonDistribution, k) + +class RobustSolitonDistribution(SingleFiniteDistribution): + _argnames= ('k', 'delta', 'c') + + @staticmethod + def check(k, delta, c): + _value_check(k.is_integer and k.is_positive, + "'k' must be a positive integer") + _value_check(Gt(delta, 0) and Le(delta, 1), + "'delta' must be a real number in the interval (0,1)") + _value_check(c.is_positive, + "'c' must be a positive real number.") + + @property + def R(self): + return self.c * log(self.k/self.delta) * self.k**0.5 + + @property + def Z(self): + z = 0 + for i in Range(1, round(self.k/self.R)): + z += (1/i) + z += log(self.R/self.delta) + return 1 + z * self.R/self.k + + @property + def low(self): + return S.One + + @property + def high(self): + return self.k + + @property + def set(self): + return set(map(Integer, range(1, self.k + 1))) + + @property + def is_symbolic(self): + return not (self.k.is_number and self.c.is_number and self.delta.is_number) + + def pmf(self, x): + x = sympify(x) + if not (x.is_number or x.is_Symbol or is_random(x)): + raise ValueError("'x' expected as an argument of type 'number', 'Symbol', or " + "'RandomSymbol' not %s" % (type(x))) + + cond1 = Eq(x, 1) & x.is_integer + cond2 = Ge(x, 1) & Le(x, self.k) & x.is_integer + rho = Piecewise((Rational(1, self.k), cond1), (Rational(1, x*(x-1)), cond2), (S.Zero, True)) + + cond1 = Ge(x, 1) & Le(x, round(self.k/self.R)-1) + cond2 = Eq(x, round(self.k/self.R)) + tau = Piecewise((self.R/(self.k * x), cond1), (self.R * log(self.R/self.delta)/self.k, cond2), (S.Zero, True)) + + return (rho + tau)/self.Z + +def RobustSoliton(name, k, delta, c): + r''' + Create a Finite Random Variable of Robust Soliton Distribution + + Parameters + ========== + + k : Positive Integer + Represents the number of input symbols in an LT (Luby Transform) code. + delta : Positive Rational Number + Represents the failure probability. Must be in the interval (0,1). + c : Positive Rational Number + Constant of proportionality. Values close to 1 are recommended + + Examples + ======== + + >>> from sympy.stats import RobustSoliton, density, P, E + >>> robSol = RobustSoliton('robSol', 5, 0.5, 0.01) + >>> density(robSol).dict + {1: 0.204253668152708, 2: 0.490631107897393, 3: 0.165210624506162, 4: 0.0834387731899302, 5: 0.0505633404760675} + >>> density(robSol).set + {1, 2, 3, 4, 5} + + >>> from sympy import Symbol + >>> k = Symbol('k', positive=True, integer=True) + >>> c = Symbol('c', positive=True) + >>> robSol = RobustSoliton('robSol', k, 0.5, c) + >>> density(robSol).dict + Density(RobustSolitonDistribution(k, 0.5, c)) + >>> density(robSol).dict.subs(k, 10).subs(c, 0.03).doit() + {1: 0.116641095387194, 2: 0.467045731687165, 3: 0.159984123349381, 4: 0.0821431680681869, 5: 0.0505765646770100, + 6: 0.0345781523420719, 7: 0.0253132820710503, 8: 0.0194459129233227, 9: 0.0154831166726115, 10: 0.0126733075238887} + + >>> E(robSol.subs(k, 10).subs(c, 0.05)) + 2.91358846104106 + + >>> P(robSol.subs(k, 4).subs(c, 0.1) > 2) + 0.243650614389834 + + Returns + ======= + + RandomSymbol + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Soliton_distribution#Robust_distribution + .. [2] https://www.inference.org.uk/mackay/itprnn/ps/588.596.pdf + .. [3] https://pages.cs.wisc.edu/~suman/courses/740/papers/luby02lt.pdf + + ''' + return rv(name, RobustSolitonDistribution, k, delta, c) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/joint_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/joint_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..d147942f08b998e167b246628360fa27fc8ef348 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/joint_rv.py @@ -0,0 +1,426 @@ +""" +Joint Random Variables Module + +See Also +======== +sympy.stats.rv +sympy.stats.frv +sympy.stats.crv +sympy.stats.drv +""" +from math import prod + +from sympy.core.basic import Basic +from sympy.core.function import Lambda +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol) +from sympy.core.sympify import sympify +from sympy.sets.sets import ProductSet +from sympy.tensor.indexed import Indexed +from sympy.concrete.products import Product +from sympy.concrete.summations import Sum, summation +from sympy.core.containers import Tuple +from sympy.integrals.integrals import Integral, integrate +from sympy.matrices import ImmutableMatrix, matrix2numpy, list2numpy +from sympy.stats.crv import SingleContinuousDistribution, SingleContinuousPSpace +from sympy.stats.drv import SingleDiscreteDistribution, SingleDiscretePSpace +from sympy.stats.rv import (ProductPSpace, NamedArgsMixin, Distribution, + ProductDomain, RandomSymbol, random_symbols, + SingleDomain, _symbol_converter) +from sympy.utilities.iterables import iterable +from sympy.utilities.misc import filldedent +from sympy.external import import_module + +# __all__ = ['marginal_distribution'] + +class JointPSpace(ProductPSpace): + """ + Represents a joint probability space. Represented using symbols for + each component and a distribution. + """ + def __new__(cls, sym, dist): + if isinstance(dist, SingleContinuousDistribution): + return SingleContinuousPSpace(sym, dist) + if isinstance(dist, SingleDiscreteDistribution): + return SingleDiscretePSpace(sym, dist) + sym = _symbol_converter(sym) + return Basic.__new__(cls, sym, dist) + + @property + def set(self): + return self.domain.set + + @property + def symbol(self): + return self.args[0] + + @property + def distribution(self): + return self.args[1] + + @property + def value(self): + return JointRandomSymbol(self.symbol, self) + + @property + def component_count(self): + _set = self.distribution.set + if isinstance(_set, ProductSet): + return S(len(_set.args)) + elif isinstance(_set, Product): + return _set.limits[0][-1] + return S.One + + @property + def pdf(self): + sym = [Indexed(self.symbol, i) for i in range(self.component_count)] + return self.distribution(*sym) + + @property + def domain(self): + rvs = random_symbols(self.distribution) + if not rvs: + return SingleDomain(self.symbol, self.distribution.set) + return ProductDomain(*[rv.pspace.domain for rv in rvs]) + + def component_domain(self, index): + return self.set.args[index] + + def marginal_distribution(self, *indices): + count = self.component_count + if count.atoms(Symbol): + raise ValueError("Marginal distributions cannot be computed " + "for symbolic dimensions. It is a work under progress.") + orig = [Indexed(self.symbol, i) for i in range(count)] + all_syms = [Symbol(str(i)) for i in orig] + replace_dict = dict(zip(all_syms, orig)) + sym = tuple(Symbol(str(Indexed(self.symbol, i))) for i in indices) + limits = [[i,] for i in all_syms if i not in sym] + index = 0 + for i in range(count): + if i not in indices: + limits[index].append(self.distribution.set.args[i]) + limits[index] = tuple(limits[index]) + index += 1 + if self.distribution.is_Continuous: + f = Lambda(sym, integrate(self.distribution(*all_syms), *limits)) + elif self.distribution.is_Discrete: + f = Lambda(sym, summation(self.distribution(*all_syms), *limits)) + return f.xreplace(replace_dict) + + def compute_expectation(self, expr, rvs=None, evaluate=False, **kwargs): + syms = tuple(self.value[i] for i in range(self.component_count)) + rvs = rvs or syms + if not any(i in rvs for i in syms): + return expr + expr = expr*self.pdf + for rv in rvs: + if isinstance(rv, Indexed): + expr = expr.xreplace({rv: Indexed(str(rv.base), rv.args[1])}) + elif isinstance(rv, RandomSymbol): + expr = expr.xreplace({rv: rv.symbol}) + if self.value in random_symbols(expr): + raise NotImplementedError(filldedent(''' + Expectations of expression with unindexed joint random symbols + cannot be calculated yet.''')) + limits = tuple((Indexed(str(rv.base),rv.args[1]), + self.distribution.set.args[rv.args[1]]) for rv in syms) + return Integral(expr, *limits) + + def where(self, condition): + raise NotImplementedError() + + def compute_density(self, expr): + raise NotImplementedError() + + def sample(self, size=(), library='scipy', seed=None): + """ + Internal sample method + + Returns dictionary mapping RandomSymbol to realization value. + """ + return {RandomSymbol(self.symbol, self): self.distribution.sample(size, + library=library, seed=seed)} + + def probability(self, condition): + raise NotImplementedError() + + +class SampleJointScipy: + """Returns the sample from scipy of the given distribution""" + def __new__(cls, dist, size, seed=None): + return cls._sample_scipy(dist, size, seed) + + @classmethod + def _sample_scipy(cls, dist, size, seed): + """Sample from SciPy.""" + + import numpy + if seed is None or isinstance(seed, int): + rand_state = numpy.random.default_rng(seed=seed) + else: + rand_state = seed + from scipy import stats as scipy_stats + scipy_rv_map = { + 'MultivariateNormalDistribution': lambda dist, size: scipy_stats.multivariate_normal.rvs( + mean=matrix2numpy(dist.mu).flatten(), + cov=matrix2numpy(dist.sigma), size=size, random_state=rand_state), + 'MultivariateBetaDistribution': lambda dist, size: scipy_stats.dirichlet.rvs( + alpha=list2numpy(dist.alpha, float).flatten(), size=size, random_state=rand_state), + 'MultinomialDistribution': lambda dist, size: scipy_stats.multinomial.rvs( + n=int(dist.n), p=list2numpy(dist.p, float).flatten(), size=size, random_state=rand_state) + } + + sample_shape = { + 'MultivariateNormalDistribution': lambda dist: matrix2numpy(dist.mu).flatten().shape, + 'MultivariateBetaDistribution': lambda dist: list2numpy(dist.alpha).flatten().shape, + 'MultinomialDistribution': lambda dist: list2numpy(dist.p).flatten().shape + } + + dist_list = scipy_rv_map.keys() + + if dist.__class__.__name__ not in dist_list: + return None + + samples = scipy_rv_map[dist.__class__.__name__](dist, size) + return samples.reshape(size + sample_shape[dist.__class__.__name__](dist)) + +class SampleJointNumpy: + """Returns the sample from numpy of the given distribution""" + + def __new__(cls, dist, size, seed=None): + return cls._sample_numpy(dist, size, seed) + + @classmethod + def _sample_numpy(cls, dist, size, seed): + """Sample from NumPy.""" + + import numpy + if seed is None or isinstance(seed, int): + rand_state = numpy.random.default_rng(seed=seed) + else: + rand_state = seed + numpy_rv_map = { + 'MultivariateNormalDistribution': lambda dist, size: rand_state.multivariate_normal( + mean=matrix2numpy(dist.mu, float).flatten(), + cov=matrix2numpy(dist.sigma, float), size=size), + 'MultivariateBetaDistribution': lambda dist, size: rand_state.dirichlet( + alpha=list2numpy(dist.alpha, float).flatten(), size=size), + 'MultinomialDistribution': lambda dist, size: rand_state.multinomial( + n=int(dist.n), pvals=list2numpy(dist.p, float).flatten(), size=size) + } + + sample_shape = { + 'MultivariateNormalDistribution': lambda dist: matrix2numpy(dist.mu).flatten().shape, + 'MultivariateBetaDistribution': lambda dist: list2numpy(dist.alpha).flatten().shape, + 'MultinomialDistribution': lambda dist: list2numpy(dist.p).flatten().shape + } + + dist_list = numpy_rv_map.keys() + + if dist.__class__.__name__ not in dist_list: + return None + + samples = numpy_rv_map[dist.__class__.__name__](dist, prod(size)) + return samples.reshape(size + sample_shape[dist.__class__.__name__](dist)) + +class SampleJointPymc: + """Returns the sample from pymc of the given distribution""" + + def __new__(cls, dist, size, seed=None): + return cls._sample_pymc(dist, size, seed) + + @classmethod + def _sample_pymc(cls, dist, size, seed): + """Sample from PyMC.""" + + try: + import pymc + except ImportError: + import pymc3 as pymc + pymc_rv_map = { + 'MultivariateNormalDistribution': lambda dist: + pymc.MvNormal('X', mu=matrix2numpy(dist.mu, float).flatten(), + cov=matrix2numpy(dist.sigma, float), shape=(1, dist.mu.shape[0])), + 'MultivariateBetaDistribution': lambda dist: + pymc.Dirichlet('X', a=list2numpy(dist.alpha, float).flatten()), + 'MultinomialDistribution': lambda dist: + pymc.Multinomial('X', n=int(dist.n), + p=list2numpy(dist.p, float).flatten(), shape=(1, len(dist.p))) + } + + sample_shape = { + 'MultivariateNormalDistribution': lambda dist: matrix2numpy(dist.mu).flatten().shape, + 'MultivariateBetaDistribution': lambda dist: list2numpy(dist.alpha).flatten().shape, + 'MultinomialDistribution': lambda dist: list2numpy(dist.p).flatten().shape + } + + dist_list = pymc_rv_map.keys() + + if dist.__class__.__name__ not in dist_list: + return None + + import logging + logging.getLogger("pymc3").setLevel(logging.ERROR) + with pymc.Model(): + pymc_rv_map[dist.__class__.__name__](dist) + samples = pymc.sample(draws=prod(size), chains=1, progressbar=False, random_seed=seed, return_inferencedata=False, compute_convergence_checks=False)[:]['X'] + return samples.reshape(size + sample_shape[dist.__class__.__name__](dist)) + + +_get_sample_class_jrv = { + 'scipy': SampleJointScipy, + 'pymc3': SampleJointPymc, + 'pymc': SampleJointPymc, + 'numpy': SampleJointNumpy +} + +class JointDistribution(Distribution, NamedArgsMixin): + """ + Represented by the random variables part of the joint distribution. + Contains methods for PDF, CDF, sampling, marginal densities, etc. + """ + + _argnames = ('pdf', ) + + def __new__(cls, *args): + args = list(map(sympify, args)) + for i in range(len(args)): + if isinstance(args[i], list): + args[i] = ImmutableMatrix(args[i]) + return Basic.__new__(cls, *args) + + @property + def domain(self): + return ProductDomain(self.symbols) + + @property + def pdf(self): + return self.density.args[1] + + def cdf(self, other): + if not isinstance(other, dict): + raise ValueError("%s should be of type dict, got %s"%(other, type(other))) + rvs = other.keys() + _set = self.domain.set.sets + expr = self.pdf(tuple(i.args[0] for i in self.symbols)) + for i in range(len(other)): + if rvs[i].is_Continuous: + density = Integral(expr, (rvs[i], _set[i].inf, + other[rvs[i]])) + elif rvs[i].is_Discrete: + density = Sum(expr, (rvs[i], _set[i].inf, + other[rvs[i]])) + return density + + def sample(self, size=(), library='scipy', seed=None): + """ A random realization from the distribution """ + + libraries = ('scipy', 'numpy', 'pymc3', 'pymc') + if library not in libraries: + raise NotImplementedError("Sampling from %s is not supported yet." + % str(library)) + if not import_module(library): + raise ValueError("Failed to import %s" % library) + + samps = _get_sample_class_jrv[library](self, size, seed=seed) + + if samps is not None: + return samps + raise NotImplementedError( + "Sampling for %s is not currently implemented from %s" + % (self.__class__.__name__, library) + ) + + def __call__(self, *args): + return self.pdf(*args) + +class JointRandomSymbol(RandomSymbol): + """ + Representation of random symbols with joint probability distributions + to allow indexing." + """ + def __getitem__(self, key): + if isinstance(self.pspace, JointPSpace): + if (self.pspace.component_count <= key) == True: + raise ValueError("Index keys for %s can only up to %s." % + (self.name, self.pspace.component_count - 1)) + return Indexed(self, key) + + + +class MarginalDistribution(Distribution): + """ + Represents the marginal distribution of a joint probability space. + + Initialised using a probability distribution and random variables(or + their indexed components) which should be a part of the resultant + distribution. + """ + + def __new__(cls, dist, *rvs): + if len(rvs) == 1 and iterable(rvs[0]): + rvs = tuple(rvs[0]) + if not all(isinstance(rv, (Indexed, RandomSymbol)) for rv in rvs): + raise ValueError(filldedent('''Marginal distribution can be + intitialised only in terms of random variables or indexed random + variables''')) + rvs = Tuple.fromiter(rv for rv in rvs) + if not isinstance(dist, JointDistribution) and len(random_symbols(dist)) == 0: + return dist + return Basic.__new__(cls, dist, rvs) + + def check(self): + pass + + @property + def set(self): + rvs = [i for i in self.args[1] if isinstance(i, RandomSymbol)] + return ProductSet(*[rv.pspace.set for rv in rvs]) + + @property + def symbols(self): + rvs = self.args[1] + return {rv.pspace.symbol for rv in rvs} + + def pdf(self, *x): + expr, rvs = self.args[0], self.args[1] + marginalise_out = [i for i in random_symbols(expr) if i not in rvs] + if isinstance(expr, JointDistribution): + count = len(expr.domain.args) + x = Dummy('x', real=True) + syms = tuple(Indexed(x, i) for i in count) + expr = expr.pdf(syms) + else: + syms = tuple(rv.pspace.symbol if isinstance(rv, RandomSymbol) else rv.args[0] for rv in rvs) + return Lambda(syms, self.compute_pdf(expr, marginalise_out))(*x) + + def compute_pdf(self, expr, rvs): + for rv in rvs: + lpdf = 1 + if isinstance(rv, RandomSymbol): + lpdf = rv.pspace.pdf + expr = self.marginalise_out(expr*lpdf, rv) + return expr + + def marginalise_out(self, expr, rv): + from sympy.concrete.summations import Sum + if isinstance(rv, RandomSymbol): + dom = rv.pspace.set + elif isinstance(rv, Indexed): + dom = rv.base.component_domain( + rv.pspace.component_domain(rv.args[1])) + expr = expr.xreplace({rv: rv.pspace.symbol}) + if rv.pspace.is_Continuous: + #TODO: Modify to support integration + #for all kinds of sets. + expr = Integral(expr, (rv.pspace.symbol, dom)) + elif rv.pspace.is_Discrete: + #incorporate this into `Sum`/`summation` + if dom in (S.Integers, S.Naturals, S.Naturals0): + dom = (dom.inf, dom.sup) + expr = Sum(expr, (rv.pspace.symbol, dom)) + return expr + + def __call__(self, *args): + return self.pdf(*args) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/joint_rv_types.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/joint_rv_types.py new file mode 100644 index 0000000000000000000000000000000000000000..6cee9f9aa30897593ffb7c7b930a55a38f0c518a --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/joint_rv_types.py @@ -0,0 +1,945 @@ +from sympy.concrete.products import Product +from sympy.concrete.summations import Sum +from sympy.core.add import Add +from sympy.core.function import Lambda +from sympy.core.mul import Mul +from sympy.core.numbers import (Integer, Rational, pi) +from sympy.core.power import Pow +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import (rf, factorial) +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.bessel import besselk +from sympy.functions.special.gamma_functions import gamma +from sympy.matrices.dense import (Matrix, ones) +from sympy.sets.fancysets import Range +from sympy.sets.sets import (Intersection, Interval) +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.matrices import ImmutableMatrix, MatrixSymbol +from sympy.matrices.expressions.determinant import det +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.stats.joint_rv import JointDistribution, JointPSpace, MarginalDistribution +from sympy.stats.rv import _value_check, random_symbols + +__all__ = ['JointRV', +'MultivariateNormal', +'MultivariateLaplace', +'Dirichlet', +'GeneralizedMultivariateLogGamma', +'GeneralizedMultivariateLogGammaOmega', +'Multinomial', +'MultivariateBeta', +'MultivariateEwens', +'MultivariateT', +'NegativeMultinomial', +'NormalGamma' +] + +def multivariate_rv(cls, sym, *args): + args = list(map(sympify, args)) + dist = cls(*args) + args = dist.args + dist.check(*args) + return JointPSpace(sym, dist).value + + +def marginal_distribution(rv, *indices): + """ + Marginal distribution function of a joint random variable. + + Parameters + ========== + + rv : A random variable with a joint probability distribution. + indices : Component indices or the indexed random symbol + for which the joint distribution is to be calculated + + Returns + ======= + + A Lambda expression in `sym`. + + Examples + ======== + + >>> from sympy.stats import MultivariateNormal, marginal_distribution + >>> m = MultivariateNormal('X', [1, 2], [[2, 1], [1, 2]]) + >>> marginal_distribution(m, m[0])(1) + 1/(2*sqrt(pi)) + + """ + indices = list(indices) + for i in range(len(indices)): + if isinstance(indices[i], Indexed): + indices[i] = indices[i].args[1] + prob_space = rv.pspace + if not indices: + raise ValueError( + "At least one component for marginal density is needed.") + if hasattr(prob_space.distribution, '_marginal_distribution'): + return prob_space.distribution._marginal_distribution(indices, rv.symbol) + return prob_space.marginal_distribution(*indices) + + +class JointDistributionHandmade(JointDistribution): + + _argnames = ('pdf',) + is_Continuous = True + + @property + def set(self): + return self.args[1] + + +def JointRV(symbol, pdf, _set=None): + """ + Create a Joint Random Variable where each of its component is continuous, + given the following: + + Parameters + ========== + + symbol : Symbol + Represents name of the random variable. + pdf : A PDF in terms of indexed symbols of the symbol given + as the first argument + + NOTE + ==== + + As of now, the set for each component for a ``JointRV`` is + equal to the set of all integers, which cannot be changed. + + Examples + ======== + + >>> from sympy import exp, pi, Indexed, S + >>> from sympy.stats import density, JointRV + >>> x1, x2 = (Indexed('x', i) for i in (1, 2)) + >>> pdf = exp(-x1**2/2 + x1 - x2**2/2 - S(1)/2)/(2*pi) + >>> N1 = JointRV('x', pdf) #Multivariate Normal distribution + >>> density(N1)(1, 2) + exp(-2)/(2*pi) + + Returns + ======= + + RandomSymbol + + """ + #TODO: Add support for sets provided by the user + symbol = sympify(symbol) + syms = [i for i in pdf.free_symbols if isinstance(i, Indexed) + and i.base == IndexedBase(symbol)] + syms = tuple(sorted(syms, key = lambda index: index.args[1])) + _set = S.Reals**len(syms) + pdf = Lambda(syms, pdf) + dist = JointDistributionHandmade(pdf, _set) + jrv = JointPSpace(symbol, dist).value + rvs = random_symbols(pdf) + if len(rvs) != 0: + dist = MarginalDistribution(dist, (jrv,)) + return JointPSpace(symbol, dist).value + return jrv + +#------------------------------------------------------------------------------- +# Multivariate Normal distribution --------------------------------------------- + +class MultivariateNormalDistribution(JointDistribution): + _argnames = ('mu', 'sigma') + + is_Continuous=True + + @property + def set(self): + k = self.mu.shape[0] + return S.Reals**k + + @staticmethod + def check(mu, sigma): + _value_check(mu.shape[0] == sigma.shape[0], + "Size of the mean vector and covariance matrix are incorrect.") + #check if covariance matrix is positive semi definite or not. + if not isinstance(sigma, MatrixSymbol): + _value_check(sigma.is_positive_semidefinite, + "The covariance matrix must be positive semi definite. ") + + def pdf(self, *args): + mu, sigma = self.mu, self.sigma + k = mu.shape[0] + if len(args) == 1 and args[0].is_Matrix: + args = args[0] + else: + args = ImmutableMatrix(args) + x = args - mu + density = S.One/sqrt((2*pi)**(k)*det(sigma))*exp( + Rational(-1, 2)*x.transpose()*(sigma.inv()*x)) + return MatrixElement(density, 0, 0) + + def _marginal_distribution(self, indices, sym): + sym = ImmutableMatrix([Indexed(sym, i) for i in indices]) + _mu, _sigma = self.mu, self.sigma + k = self.mu.shape[0] + for i in range(k): + if i not in indices: + _mu = _mu.row_del(i) + _sigma = _sigma.col_del(i) + _sigma = _sigma.row_del(i) + return Lambda(tuple(sym), S.One/sqrt((2*pi)**(len(_mu))*det(_sigma))*exp( + Rational(-1, 2)*(_mu - sym).transpose()*(_sigma.inv()*\ + (_mu - sym)))[0]) + +def MultivariateNormal(name, mu, sigma): + r""" + Creates a continuous random variable with Multivariate Normal + Distribution. + + The density of the multivariate normal distribution can be found at [1]. + + Parameters + ========== + + mu : List representing the mean or the mean vector + sigma : Positive semidefinite square matrix + Represents covariance Matrix. + If `\sigma` is noninvertible then only sampling is supported currently + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import MultivariateNormal, density, marginal_distribution + >>> from sympy import symbols, MatrixSymbol + >>> X = MultivariateNormal('X', [3, 4], [[2, 1], [1, 2]]) + >>> y, z = symbols('y z') + >>> density(X)(y, z) + sqrt(3)*exp(-y**2/3 + y*z/3 + 2*y/3 - z**2/3 + 5*z/3 - 13/3)/(6*pi) + >>> density(X)(1, 2) + sqrt(3)*exp(-4/3)/(6*pi) + >>> marginal_distribution(X, X[1])(y) + exp(-(y - 4)**2/4)/(2*sqrt(pi)) + >>> marginal_distribution(X, X[0])(y) + exp(-(y - 3)**2/4)/(2*sqrt(pi)) + + The example below shows that it is also possible to use + symbolic parameters to define the MultivariateNormal class. + + >>> n = symbols('n', integer=True, positive=True) + >>> Sg = MatrixSymbol('Sg', n, n) + >>> mu = MatrixSymbol('mu', n, 1) + >>> obs = MatrixSymbol('obs', n, 1) + >>> X = MultivariateNormal('X', mu, Sg) + + The density of a multivariate normal can be + calculated using a matrix argument, as shown below. + + >>> density(X)(obs) + (exp(((1/2)*mu.T - (1/2)*obs.T)*Sg**(-1)*(-mu + obs))/sqrt((2*pi)**n*Determinant(Sg)))[0, 0] + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Multivariate_normal_distribution + + """ + return multivariate_rv(MultivariateNormalDistribution, name, mu, sigma) + +#------------------------------------------------------------------------------- +# Multivariate Laplace distribution -------------------------------------------- + +class MultivariateLaplaceDistribution(JointDistribution): + _argnames = ('mu', 'sigma') + is_Continuous=True + + @property + def set(self): + k = self.mu.shape[0] + return S.Reals**k + + @staticmethod + def check(mu, sigma): + _value_check(mu.shape[0] == sigma.shape[0], + "Size of the mean vector and covariance matrix are incorrect.") + # check if covariance matrix is positive definite or not. + if not isinstance(sigma, MatrixSymbol): + _value_check(sigma.is_positive_definite, + "The covariance matrix must be positive definite. ") + + def pdf(self, *args): + mu, sigma = self.mu, self.sigma + mu_T = mu.transpose() + k = S(mu.shape[0]) + sigma_inv = sigma.inv() + args = ImmutableMatrix(args) + args_T = args.transpose() + x = (mu_T*sigma_inv*mu)[0] + y = (args_T*sigma_inv*args)[0] + v = 1 - k/2 + return (2 * (y/(2 + x))**(v/2) * besselk(v, sqrt((2 + x)*y)) * + exp((args_T * sigma_inv * mu)[0]) / + ((2 * pi)**(k/2) * sqrt(det(sigma)))) + + +def MultivariateLaplace(name, mu, sigma): + """ + Creates a continuous random variable with Multivariate Laplace + Distribution. + + The density of the multivariate Laplace distribution can be found at [1]. + + Parameters + ========== + + mu : List representing the mean or the mean vector + sigma : Positive definite square matrix + Represents covariance Matrix + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import MultivariateLaplace, density + >>> from sympy import symbols + >>> y, z = symbols('y z') + >>> X = MultivariateLaplace('X', [2, 4], [[3, 1], [1, 3]]) + >>> density(X)(y, z) + sqrt(2)*exp(y/4 + 5*z/4)*besselk(0, sqrt(15*y*(3*y/8 - z/8)/2 + 15*z*(-y/8 + 3*z/8)/2))/(4*pi) + >>> density(X)(1, 2) + sqrt(2)*exp(11/4)*besselk(0, sqrt(165)/4)/(4*pi) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Multivariate_Laplace_distribution + + """ + return multivariate_rv(MultivariateLaplaceDistribution, name, mu, sigma) + +#------------------------------------------------------------------------------- +# Multivariate StudentT distribution ------------------------------------------- + +class MultivariateTDistribution(JointDistribution): + _argnames = ('mu', 'shape_mat', 'dof') + is_Continuous=True + + @property + def set(self): + k = self.mu.shape[0] + return S.Reals**k + + @staticmethod + def check(mu, sigma, v): + _value_check(mu.shape[0] == sigma.shape[0], + "Size of the location vector and shape matrix are incorrect.") + # check if covariance matrix is positive definite or not. + if not isinstance(sigma, MatrixSymbol): + _value_check(sigma.is_positive_definite, + "The shape matrix must be positive definite. ") + + def pdf(self, *args): + mu, sigma = self.mu, self.shape_mat + v = S(self.dof) + k = S(mu.shape[0]) + sigma_inv = sigma.inv() + args = ImmutableMatrix(args) + x = args - mu + return gamma((k + v)/2)/(gamma(v/2)*(v*pi)**(k/2)*sqrt(det(sigma)))\ + *(1 + 1/v*(x.transpose()*sigma_inv*x)[0])**((-v - k)/2) + +def MultivariateT(syms, mu, sigma, v): + """ + Creates a joint random variable with multivariate T-distribution. + + Parameters + ========== + + syms : A symbol/str + For identifying the random variable. + mu : A list/matrix + Representing the location vector + sigma : The shape matrix for the distribution + + Examples + ======== + + >>> from sympy.stats import density, MultivariateT + >>> from sympy import Symbol + + >>> x = Symbol("x") + >>> X = MultivariateT("x", [1, 1], [[1, 0], [0, 1]], 2) + + >>> density(X)(1, 2) + 2/(9*pi) + + Returns + ======= + + RandomSymbol + + """ + return multivariate_rv(MultivariateTDistribution, syms, mu, sigma, v) + + +#------------------------------------------------------------------------------- +# Multivariate Normal Gamma distribution --------------------------------------- + +class NormalGammaDistribution(JointDistribution): + + _argnames = ('mu', 'lamda', 'alpha', 'beta') + is_Continuous=True + + @staticmethod + def check(mu, lamda, alpha, beta): + _value_check(mu.is_real, "Location must be real.") + _value_check(lamda > 0, "Lambda must be positive") + _value_check(alpha > 0, "alpha must be positive") + _value_check(beta > 0, "beta must be positive") + + @property + def set(self): + return S.Reals*Interval(0, S.Infinity) + + def pdf(self, x, tau): + beta, alpha, lamda = self.beta, self.alpha, self.lamda + mu = self.mu + + return beta**alpha*sqrt(lamda)/(gamma(alpha)*sqrt(2*pi))*\ + tau**(alpha - S.Half)*exp(-1*beta*tau)*\ + exp(-1*(lamda*tau*(x - mu)**2)/S(2)) + + def _marginal_distribution(self, indices, *sym): + if len(indices) == 2: + return self.pdf(*sym) + if indices[0] == 0: + #For marginal over `x`, return non-standardized Student-T's + #distribution + x = sym[0] + v, mu, sigma = self.alpha - S.Half, self.mu, \ + S(self.beta)/(self.lamda * self.alpha) + return Lambda(sym, gamma((v + 1)/2)/(gamma(v/2)*sqrt(pi*v)*sigma)*\ + (1 + 1/v*((x - mu)/sigma)**2)**((-v -1)/2)) + #For marginal over `tau`, return Gamma distribution as per construction + from sympy.stats.crv_types import GammaDistribution + return Lambda(sym, GammaDistribution(self.alpha, self.beta)(sym[0])) + +def NormalGamma(sym, mu, lamda, alpha, beta): + """ + Creates a bivariate joint random variable with multivariate Normal gamma + distribution. + + Parameters + ========== + + sym : A symbol/str + For identifying the random variable. + mu : A real number + The mean of the normal distribution + lamda : A positive integer + Parameter of joint distribution + alpha : A positive integer + Parameter of joint distribution + beta : A positive integer + Parameter of joint distribution + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, NormalGamma + >>> from sympy import symbols + + >>> X = NormalGamma('x', 0, 1, 2, 3) + >>> y, z = symbols('y z') + + >>> density(X)(y, z) + 9*sqrt(2)*z**(3/2)*exp(-3*z)*exp(-y**2*z/2)/(2*sqrt(pi)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Normal-gamma_distribution + + """ + return multivariate_rv(NormalGammaDistribution, sym, mu, lamda, alpha, beta) + +#------------------------------------------------------------------------------- +# Multivariate Beta/Dirichlet distribution ------------------------------------- + +class MultivariateBetaDistribution(JointDistribution): + + _argnames = ('alpha',) + is_Continuous = True + + @staticmethod + def check(alpha): + _value_check(len(alpha) >= 2, "At least two categories should be passed.") + for a_k in alpha: + _value_check((a_k > 0) != False, "Each concentration parameter" + " should be positive.") + + @property + def set(self): + k = len(self.alpha) + return Interval(0, 1)**k + + def pdf(self, *syms): + alpha = self.alpha + B = Mul.fromiter(map(gamma, alpha))/gamma(Add(*alpha)) + return Mul.fromiter(sym**(a_k - 1) for a_k, sym in zip(alpha, syms))/B + +def MultivariateBeta(syms, *alpha): + """ + Creates a continuous random variable with Dirichlet/Multivariate Beta + Distribution. + + The density of the Dirichlet distribution can be found at [1]. + + Parameters + ========== + + alpha : Positive real numbers + Signifies concentration numbers. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, MultivariateBeta, marginal_distribution + >>> from sympy import Symbol + >>> a1 = Symbol('a1', positive=True) + >>> a2 = Symbol('a2', positive=True) + >>> B = MultivariateBeta('B', [a1, a2]) + >>> C = MultivariateBeta('C', a1, a2) + >>> x = Symbol('x') + >>> y = Symbol('y') + >>> density(B)(x, y) + x**(a1 - 1)*y**(a2 - 1)*gamma(a1 + a2)/(gamma(a1)*gamma(a2)) + >>> marginal_distribution(C, C[0])(x) + x**(a1 - 1)*gamma(a1 + a2)/(a2*gamma(a1)*gamma(a2)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Dirichlet_distribution + .. [2] https://mathworld.wolfram.com/DirichletDistribution.html + + """ + if not isinstance(alpha[0], list): + alpha = (list(alpha),) + return multivariate_rv(MultivariateBetaDistribution, syms, alpha[0]) + +Dirichlet = MultivariateBeta + +#------------------------------------------------------------------------------- +# Multivariate Ewens distribution ---------------------------------------------- + +class MultivariateEwensDistribution(JointDistribution): + + _argnames = ('n', 'theta') + is_Discrete = True + is_Continuous = False + + @staticmethod + def check(n, theta): + _value_check((n > 0), + "sample size should be positive integer.") + _value_check(theta.is_positive, "mutation rate should be positive.") + + @property + def set(self): + if not isinstance(self.n, Integer): + i = Symbol('i', integer=True, positive=True) + return Product(Intersection(S.Naturals0, Interval(0, self.n//i)), + (i, 1, self.n)) + prod_set = Range(0, self.n + 1) + for i in range(2, self.n + 1): + prod_set *= Range(0, self.n//i + 1) + return prod_set.flatten() + + def pdf(self, *syms): + n, theta = self.n, self.theta + condi = isinstance(self.n, Integer) + if not (isinstance(syms[0], IndexedBase) or condi): + raise ValueError("Please use IndexedBase object for syms as " + "the dimension is symbolic") + term_1 = factorial(n)/rf(theta, n) + if condi: + term_2 = Mul.fromiter(theta**syms[j]/((j+1)**syms[j]*factorial(syms[j])) + for j in range(n)) + cond = Eq(sum((k + 1)*syms[k] for k in range(n)), n) + return Piecewise((term_1 * term_2, cond), (0, True)) + syms = syms[0] + j, k = symbols('j, k', positive=True, integer=True) + term_2 = Product(theta**syms[j]/((j+1)**syms[j]*factorial(syms[j])), + (j, 0, n - 1)) + cond = Eq(Sum((k + 1)*syms[k], (k, 0, n - 1)), n) + return Piecewise((term_1 * term_2, cond), (0, True)) + + +def MultivariateEwens(syms, n, theta): + """ + Creates a discrete random variable with Multivariate Ewens + Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + n : Positive integer + Size of the sample or the integer whose partitions are considered + theta : Positive real number + Denotes Mutation rate + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, marginal_distribution, MultivariateEwens + >>> from sympy import Symbol + >>> a1 = Symbol('a1', positive=True) + >>> a2 = Symbol('a2', positive=True) + >>> ed = MultivariateEwens('E', 2, 1) + >>> density(ed)(a1, a2) + Piecewise((1/(2**a2*factorial(a1)*factorial(a2)), Eq(a1 + 2*a2, 2)), (0, True)) + >>> marginal_distribution(ed, ed[0])(a1) + Piecewise((1/factorial(a1), Eq(a1, 2)), (0, True)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Ewens%27s_sampling_formula + .. [2] https://www.jstor.org/stable/24780825 + """ + return multivariate_rv(MultivariateEwensDistribution, syms, n, theta) + +#------------------------------------------------------------------------------- +# Generalized Multivariate Log Gamma distribution ------------------------------ + +class GeneralizedMultivariateLogGammaDistribution(JointDistribution): + + _argnames = ('delta', 'v', 'lamda', 'mu') + is_Continuous=True + + def check(self, delta, v, l, mu): + _value_check((delta >= 0, delta <= 1), "delta must be in range [0, 1].") + _value_check((v > 0), "v must be positive") + for lk in l: + _value_check((lk > 0), "lamda must be a positive vector.") + for muk in mu: + _value_check((muk > 0), "mu must be a positive vector.") + _value_check(len(l) > 1,"the distribution should have at least" + " two random variables.") + + @property + def set(self): + return S.Reals**len(self.lamda) + + def pdf(self, *y): + d, v, l, mu = self.delta, self.v, self.lamda, self.mu + n = Symbol('n', negative=False, integer=True) + k = len(l) + sterm1 = Pow((1 - d), n)/\ + ((gamma(v + n)**(k - 1))*gamma(v)*gamma(n + 1)) + sterm2 = Mul.fromiter(mui*li**(-v - n) for mui, li in zip(mu, l)) + term1 = sterm1 * sterm2 + sterm3 = (v + n) * sum(mui * yi for mui, yi in zip(mu, y)) + sterm4 = sum(exp(mui * yi)/li for (mui, yi, li) in zip(mu, y, l)) + term2 = exp(sterm3 - sterm4) + return Pow(d, v) * Sum(term1 * term2, (n, 0, S.Infinity)) + +def GeneralizedMultivariateLogGamma(syms, delta, v, lamda, mu): + """ + Creates a joint random variable with generalized multivariate log gamma + distribution. + + The joint pdf can be found at [1]. + + Parameters + ========== + + syms : list/tuple/set of symbols for identifying each component + delta : A constant in range $[0, 1]$ + v : Positive real number + lamda : List of positive real numbers + mu : List of positive real numbers + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density + >>> from sympy.stats.joint_rv_types import GeneralizedMultivariateLogGamma + >>> from sympy import symbols, S + >>> v = 1 + >>> l, mu = [1, 1, 1], [1, 1, 1] + >>> d = S.Half + >>> y = symbols('y_1:4', positive=True) + >>> Gd = GeneralizedMultivariateLogGamma('G', d, v, l, mu) + >>> density(Gd)(y[0], y[1], y[2]) + Sum(exp((n + 1)*(y_1 + y_2 + y_3) - exp(y_1) - exp(y_2) - + exp(y_3))/(2**n*gamma(n + 1)**3), (n, 0, oo))/2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Generalized_multivariate_log-gamma_distribution + .. [2] https://www.researchgate.net/publication/234137346_On_a_multivariate_log-gamma_distribution_and_the_use_of_the_distribution_in_the_Bayesian_analysis + + Note + ==== + + If the GeneralizedMultivariateLogGamma is too long to type use, + + >>> from sympy.stats.joint_rv_types import GeneralizedMultivariateLogGamma as GMVLG + >>> Gd = GMVLG('G', d, v, l, mu) + + If you want to pass the matrix omega instead of the constant delta, then use + ``GeneralizedMultivariateLogGammaOmega``. + + """ + return multivariate_rv(GeneralizedMultivariateLogGammaDistribution, + syms, delta, v, lamda, mu) + +def GeneralizedMultivariateLogGammaOmega(syms, omega, v, lamda, mu): + """ + Extends GeneralizedMultivariateLogGamma. + + Parameters + ========== + + syms : list/tuple/set of symbols + For identifying each component + omega : A square matrix + Every element of square matrix must be absolute value of + square root of correlation coefficient + v : Positive real number + lamda : List of positive real numbers + mu : List of positive real numbers + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density + >>> from sympy.stats.joint_rv_types import GeneralizedMultivariateLogGammaOmega + >>> from sympy import Matrix, symbols, S + >>> omega = Matrix([[1, S.Half, S.Half], [S.Half, 1, S.Half], [S.Half, S.Half, 1]]) + >>> v = 1 + >>> l, mu = [1, 1, 1], [1, 1, 1] + >>> G = GeneralizedMultivariateLogGammaOmega('G', omega, v, l, mu) + >>> y = symbols('y_1:4', positive=True) + >>> density(G)(y[0], y[1], y[2]) + sqrt(2)*Sum((1 - sqrt(2)/2)**n*exp((n + 1)*(y_1 + y_2 + y_3) - exp(y_1) - + exp(y_2) - exp(y_3))/gamma(n + 1)**3, (n, 0, oo))/2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Generalized_multivariate_log-gamma_distribution + .. [2] https://www.researchgate.net/publication/234137346_On_a_multivariate_log-gamma_distribution_and_the_use_of_the_distribution_in_the_Bayesian_analysis + + Notes + ===== + + If the GeneralizedMultivariateLogGammaOmega is too long to type use, + + >>> from sympy.stats.joint_rv_types import GeneralizedMultivariateLogGammaOmega as GMVLGO + >>> G = GMVLGO('G', omega, v, l, mu) + + """ + _value_check((omega.is_square, isinstance(omega, Matrix)), "omega must be a" + " square matrix") + for val in omega.values(): + _value_check((val >= 0, val <= 1), + "all values in matrix must be between 0 and 1(both inclusive).") + _value_check(omega.diagonal().equals(ones(1, omega.shape[0])), + "all the elements of diagonal should be 1.") + _value_check((omega.shape[0] == len(lamda), len(lamda) == len(mu)), + "lamda, mu should be of same length and omega should " + " be of shape (length of lamda, length of mu)") + _value_check(len(lamda) > 1,"the distribution should have at least" + " two random variables.") + delta = Pow(Rational(omega.det()), Rational(1, len(lamda) - 1)) + return GeneralizedMultivariateLogGamma(syms, delta, v, lamda, mu) + + +#------------------------------------------------------------------------------- +# Multinomial distribution ----------------------------------------------------- + +class MultinomialDistribution(JointDistribution): + + _argnames = ('n', 'p') + is_Continuous=False + is_Discrete = True + + @staticmethod + def check(n, p): + _value_check(n > 0, + "number of trials must be a positive integer") + for p_k in p: + _value_check((p_k >= 0, p_k <= 1), + "probability must be in range [0, 1]") + _value_check(Eq(sum(p), 1), + "probabilities must sum to 1") + + @property + def set(self): + return Intersection(S.Naturals0, Interval(0, self.n))**len(self.p) + + def pdf(self, *x): + n, p = self.n, self.p + term_1 = factorial(n)/Mul.fromiter(factorial(x_k) for x_k in x) + term_2 = Mul.fromiter(p_k**x_k for p_k, x_k in zip(p, x)) + return Piecewise((term_1 * term_2, Eq(sum(x), n)), (0, True)) + +def Multinomial(syms, n, *p): + """ + Creates a discrete random variable with Multinomial Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + n : Positive integer + Represents number of trials + p : List of event probabilities + Must be in the range of $[0, 1]$. + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, Multinomial, marginal_distribution + >>> from sympy import symbols + >>> x1, x2, x3 = symbols('x1, x2, x3', nonnegative=True, integer=True) + >>> p1, p2, p3 = symbols('p1, p2, p3', positive=True) + >>> M = Multinomial('M', 3, p1, p2, p3) + >>> density(M)(x1, x2, x3) + Piecewise((6*p1**x1*p2**x2*p3**x3/(factorial(x1)*factorial(x2)*factorial(x3)), + Eq(x1 + x2 + x3, 3)), (0, True)) + >>> marginal_distribution(M, M[0])(x1).subs(x1, 1) + 3*p1*p2**2 + 6*p1*p2*p3 + 3*p1*p3**2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Multinomial_distribution + .. [2] https://mathworld.wolfram.com/MultinomialDistribution.html + + """ + if not isinstance(p[0], list): + p = (list(p), ) + return multivariate_rv(MultinomialDistribution, syms, n, p[0]) + +#------------------------------------------------------------------------------- +# Negative Multinomial Distribution -------------------------------------------- + +class NegativeMultinomialDistribution(JointDistribution): + + _argnames = ('k0', 'p') + is_Continuous=False + is_Discrete = True + + @staticmethod + def check(k0, p): + _value_check(k0 > 0, + "number of failures must be a positive integer") + for p_k in p: + _value_check((p_k >= 0, p_k <= 1), + "probability must be in range [0, 1].") + _value_check(sum(p) <= 1, + "success probabilities must not be greater than 1.") + + @property + def set(self): + return Range(0, S.Infinity)**len(self.p) + + def pdf(self, *k): + k0, p = self.k0, self.p + term_1 = (gamma(k0 + sum(k))*(1 - sum(p))**k0)/gamma(k0) + term_2 = Mul.fromiter(pi**ki/factorial(ki) for pi, ki in zip(p, k)) + return term_1 * term_2 + +def NegativeMultinomial(syms, k0, *p): + """ + Creates a discrete random variable with Negative Multinomial Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + k0 : positive integer + Represents number of failures before the experiment is stopped + p : List of event probabilities + Must be in the range of $[0, 1]$ + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, NegativeMultinomial, marginal_distribution + >>> from sympy import symbols + >>> x1, x2, x3 = symbols('x1, x2, x3', nonnegative=True, integer=True) + >>> p1, p2, p3 = symbols('p1, p2, p3', positive=True) + >>> N = NegativeMultinomial('M', 3, p1, p2, p3) + >>> N_c = NegativeMultinomial('M', 3, 0.1, 0.1, 0.1) + >>> density(N)(x1, x2, x3) + p1**x1*p2**x2*p3**x3*(-p1 - p2 - p3 + 1)**3*gamma(x1 + x2 + + x3 + 3)/(2*factorial(x1)*factorial(x2)*factorial(x3)) + >>> marginal_distribution(N_c, N_c[0])(1).evalf().round(2) + 0.25 + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Negative_multinomial_distribution + .. [2] https://mathworld.wolfram.com/NegativeBinomialDistribution.html + + """ + if not isinstance(p[0], list): + p = (list(p), ) + return multivariate_rv(NegativeMultinomialDistribution, syms, k0, p[0]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/matrix_distributions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/matrix_distributions.py new file mode 100644 index 0000000000000000000000000000000000000000..9a43c0226bc25702211a910ebbe30e280ad0cf50 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/matrix_distributions.py @@ -0,0 +1,610 @@ +from math import prod + +from sympy.core.basic import Basic +from sympy.core.numbers import pi +from sympy.core.singleton import S +from sympy.functions.elementary.exponential import exp +from sympy.functions.special.gamma_functions import multigamma +from sympy.core.sympify import sympify, _sympify +from sympy.matrices import (ImmutableMatrix, Inverse, Trace, Determinant, + MatrixSymbol, MatrixBase, Transpose, MatrixSet, + matrix2numpy) +from sympy.stats.rv import (_value_check, RandomMatrixSymbol, NamedArgsMixin, PSpace, + _symbol_converter, MatrixDomain, Distribution) +from sympy.external import import_module + + +################################################################################ +#------------------------Matrix Probability Space------------------------------# +################################################################################ +class MatrixPSpace(PSpace): + """ + Represents probability space for + Matrix Distributions. + """ + def __new__(cls, sym, distribution, dim_n, dim_m): + sym = _symbol_converter(sym) + dim_n, dim_m = _sympify(dim_n), _sympify(dim_m) + if not (dim_n.is_integer and dim_m.is_integer): + raise ValueError("Dimensions should be integers") + return Basic.__new__(cls, sym, distribution, dim_n, dim_m) + + distribution = property(lambda self: self.args[1]) + symbol = property(lambda self: self.args[0]) + + @property + def domain(self): + return MatrixDomain(self.symbol, self.distribution.set) + + @property + def value(self): + return RandomMatrixSymbol(self.symbol, self.args[2], self.args[3], self) + + @property + def values(self): + return {self.value} + + def compute_density(self, expr, *args): + rms = expr.atoms(RandomMatrixSymbol) + if len(rms) > 1 or (not isinstance(expr, RandomMatrixSymbol)): + raise NotImplementedError("Currently, no algorithm has been " + "implemented to handle general expressions containing " + "multiple matrix distributions.") + return self.distribution.pdf(expr) + + def sample(self, size=(), library='scipy', seed=None): + """ + Internal sample method + + Returns dictionary mapping RandomMatrixSymbol to realization value. + """ + return {self.value: self.distribution.sample(size, library=library, seed=seed)} + + +def rv(symbol, cls, args): + args = list(map(sympify, args)) + dist = cls(*args) + dist.check(*args) + dim = dist.dimension + pspace = MatrixPSpace(symbol, dist, dim[0], dim[1]) + return pspace.value + + +class SampleMatrixScipy: + """Returns the sample from scipy of the given distribution""" + def __new__(cls, dist, size, seed=None): + return cls._sample_scipy(dist, size, seed) + + @classmethod + def _sample_scipy(cls, dist, size, seed): + """Sample from SciPy.""" + + from scipy import stats as scipy_stats + import numpy + scipy_rv_map = { + 'WishartDistribution': lambda dist, size, rand_state: scipy_stats.wishart.rvs( + df=int(dist.n), scale=matrix2numpy(dist.scale_matrix, float), size=size), + 'MatrixNormalDistribution': lambda dist, size, rand_state: scipy_stats.matrix_normal.rvs( + mean=matrix2numpy(dist.location_matrix, float), + rowcov=matrix2numpy(dist.scale_matrix_1, float), + colcov=matrix2numpy(dist.scale_matrix_2, float), size=size, random_state=rand_state) + } + + sample_shape = { + 'WishartDistribution': lambda dist: dist.scale_matrix.shape, + 'MatrixNormalDistribution' : lambda dist: dist.location_matrix.shape + } + + dist_list = scipy_rv_map.keys() + + if dist.__class__.__name__ not in dist_list: + return None + + if seed is None or isinstance(seed, int): + rand_state = numpy.random.default_rng(seed=seed) + else: + rand_state = seed + samp = scipy_rv_map[dist.__class__.__name__](dist, prod(size), rand_state) + return samp.reshape(size + sample_shape[dist.__class__.__name__](dist)) + + +class SampleMatrixNumpy: + """Returns the sample from numpy of the given distribution""" + + ### TODO: Add tests after adding matrix distributions in numpy_rv_map + def __new__(cls, dist, size, seed=None): + return cls._sample_numpy(dist, size, seed) + + @classmethod + def _sample_numpy(cls, dist, size, seed): + """Sample from NumPy.""" + + numpy_rv_map = { + } + + sample_shape = { + } + + dist_list = numpy_rv_map.keys() + + if dist.__class__.__name__ not in dist_list: + return None + + import numpy + if seed is None or isinstance(seed, int): + rand_state = numpy.random.default_rng(seed=seed) + else: + rand_state = seed + samp = numpy_rv_map[dist.__class__.__name__](dist, prod(size), rand_state) + return samp.reshape(size + sample_shape[dist.__class__.__name__](dist)) + + +class SampleMatrixPymc: + """Returns the sample from pymc of the given distribution""" + + def __new__(cls, dist, size, seed=None): + return cls._sample_pymc(dist, size, seed) + + @classmethod + def _sample_pymc(cls, dist, size, seed): + """Sample from PyMC.""" + + try: + import pymc + except ImportError: + import pymc3 as pymc + pymc_rv_map = { + 'MatrixNormalDistribution': lambda dist: pymc.MatrixNormal('X', + mu=matrix2numpy(dist.location_matrix, float), + rowcov=matrix2numpy(dist.scale_matrix_1, float), + colcov=matrix2numpy(dist.scale_matrix_2, float), + shape=dist.location_matrix.shape), + 'WishartDistribution': lambda dist: pymc.WishartBartlett('X', + nu=int(dist.n), S=matrix2numpy(dist.scale_matrix, float)) + } + + sample_shape = { + 'WishartDistribution': lambda dist: dist.scale_matrix.shape, + 'MatrixNormalDistribution' : lambda dist: dist.location_matrix.shape + } + + dist_list = pymc_rv_map.keys() + + if dist.__class__.__name__ not in dist_list: + return None + import logging + logging.getLogger("pymc").setLevel(logging.ERROR) + with pymc.Model(): + pymc_rv_map[dist.__class__.__name__](dist) + samps = pymc.sample(draws=prod(size), chains=1, progressbar=False, random_seed=seed, return_inferencedata=False, compute_convergence_checks=False)['X'] + return samps.reshape(size + sample_shape[dist.__class__.__name__](dist)) + +_get_sample_class_matrixrv = { + 'scipy': SampleMatrixScipy, + 'pymc3': SampleMatrixPymc, + 'pymc': SampleMatrixPymc, + 'numpy': SampleMatrixNumpy +} + +################################################################################ +#-------------------------Matrix Distribution----------------------------------# +################################################################################ + +class MatrixDistribution(Distribution, NamedArgsMixin): + """ + Abstract class for Matrix Distribution. + """ + def __new__(cls, *args): + args = [ImmutableMatrix(arg) if isinstance(arg, list) + else _sympify(arg) for arg in args] + return Basic.__new__(cls, *args) + + @staticmethod + def check(*args): + pass + + def __call__(self, expr): + if isinstance(expr, list): + expr = ImmutableMatrix(expr) + return self.pdf(expr) + + def sample(self, size=(), library='scipy', seed=None): + """ + Internal sample method + + Returns dictionary mapping RandomSymbol to realization value. + """ + + libraries = ['scipy', 'numpy', 'pymc3', 'pymc'] + if library not in libraries: + raise NotImplementedError("Sampling from %s is not supported yet." + % str(library)) + if not import_module(library): + raise ValueError("Failed to import %s" % library) + + samps = _get_sample_class_matrixrv[library](self, size, seed) + + if samps is not None: + return samps + raise NotImplementedError( + "Sampling for %s is not currently implemented from %s" + % (self.__class__.__name__, library) + ) + +################################################################################ +#------------------------Matrix Distribution Types-----------------------------# +################################################################################ + +#------------------------------------------------------------------------------- +# Matrix Gamma distribution ---------------------------------------------------- + +class MatrixGammaDistribution(MatrixDistribution): + + _argnames = ('alpha', 'beta', 'scale_matrix') + + @staticmethod + def check(alpha, beta, scale_matrix): + if not isinstance(scale_matrix, MatrixSymbol): + _value_check(scale_matrix.is_positive_definite, "The shape " + "matrix must be positive definite.") + _value_check(scale_matrix.is_square, "Should " + "be square matrix") + _value_check(alpha.is_positive, "Shape parameter should be positive.") + _value_check(beta.is_positive, "Scale parameter should be positive.") + + @property + def set(self): + k = self.scale_matrix.shape[0] + return MatrixSet(k, k, S.Reals) + + @property + def dimension(self): + return self.scale_matrix.shape + + def pdf(self, x): + alpha, beta, scale_matrix = self.alpha, self.beta, self.scale_matrix + p = scale_matrix.shape[0] + if isinstance(x, list): + x = ImmutableMatrix(x) + if not isinstance(x, (MatrixBase, MatrixSymbol)): + raise ValueError("%s should be an isinstance of Matrix " + "or MatrixSymbol" % str(x)) + sigma_inv_x = - Inverse(scale_matrix)*x / beta + term1 = exp(Trace(sigma_inv_x))/((beta**(p*alpha)) * multigamma(alpha, p)) + term2 = (Determinant(scale_matrix))**(-alpha) + term3 = (Determinant(x))**(alpha - S(p + 1)/2) + return term1 * term2 * term3 + +def MatrixGamma(symbol, alpha, beta, scale_matrix): + """ + Creates a random variable with Matrix Gamma Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + alpha: Positive Real number + Shape Parameter + beta: Positive Real number + Scale Parameter + scale_matrix: Positive definite real square matrix + Scale Matrix + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, MatrixGamma + >>> from sympy import MatrixSymbol, symbols + >>> a, b = symbols('a b', positive=True) + >>> M = MatrixGamma('M', a, b, [[2, 1], [1, 2]]) + >>> X = MatrixSymbol('X', 2, 2) + >>> density(M)(X).doit() + exp(Trace(Matrix([ + [-2/3, 1/3], + [ 1/3, -2/3]])*X)/b)*Determinant(X)**(a - 3/2)/(3**a*sqrt(pi)*b**(2*a)*gamma(a)*gamma(a - 1/2)) + >>> density(M)([[1, 0], [0, 1]]).doit() + exp(-4/(3*b))/(3**a*sqrt(pi)*b**(2*a)*gamma(a)*gamma(a - 1/2)) + + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Matrix_gamma_distribution + + """ + if isinstance(scale_matrix, list): + scale_matrix = ImmutableMatrix(scale_matrix) + return rv(symbol, MatrixGammaDistribution, (alpha, beta, scale_matrix)) + +#------------------------------------------------------------------------------- +# Wishart Distribution --------------------------------------------------------- + +class WishartDistribution(MatrixDistribution): + + _argnames = ('n', 'scale_matrix') + + @staticmethod + def check(n, scale_matrix): + if not isinstance(scale_matrix, MatrixSymbol): + _value_check(scale_matrix.is_positive_definite, "The shape " + "matrix must be positive definite.") + _value_check(scale_matrix.is_square, "Should " + "be square matrix") + _value_check(n.is_positive, "Shape parameter should be positive.") + + @property + def set(self): + k = self.scale_matrix.shape[0] + return MatrixSet(k, k, S.Reals) + + @property + def dimension(self): + return self.scale_matrix.shape + + def pdf(self, x): + n, scale_matrix = self.n, self.scale_matrix + p = scale_matrix.shape[0] + if isinstance(x, list): + x = ImmutableMatrix(x) + if not isinstance(x, (MatrixBase, MatrixSymbol)): + raise ValueError("%s should be an isinstance of Matrix " + "or MatrixSymbol" % str(x)) + sigma_inv_x = - Inverse(scale_matrix)*x / S(2) + term1 = exp(Trace(sigma_inv_x))/((2**(p*n/S(2))) * multigamma(n/S(2), p)) + term2 = (Determinant(scale_matrix))**(-n/S(2)) + term3 = (Determinant(x))**(S(n - p - 1)/2) + return term1 * term2 * term3 + +def Wishart(symbol, n, scale_matrix): + """ + Creates a random variable with Wishart Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + n: Positive Real number + Represents degrees of freedom + scale_matrix: Positive definite real square matrix + Scale Matrix + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy.stats import density, Wishart + >>> from sympy import MatrixSymbol, symbols + >>> n = symbols('n', positive=True) + >>> W = Wishart('W', n, [[2, 1], [1, 2]]) + >>> X = MatrixSymbol('X', 2, 2) + >>> density(W)(X).doit() + exp(Trace(Matrix([ + [-1/3, 1/6], + [ 1/6, -1/3]])*X))*Determinant(X)**(n/2 - 3/2)/(2**n*3**(n/2)*sqrt(pi)*gamma(n/2)*gamma(n/2 - 1/2)) + >>> density(W)([[1, 0], [0, 1]]).doit() + exp(-2/3)/(2**n*3**(n/2)*sqrt(pi)*gamma(n/2)*gamma(n/2 - 1/2)) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Wishart_distribution + + """ + if isinstance(scale_matrix, list): + scale_matrix = ImmutableMatrix(scale_matrix) + return rv(symbol, WishartDistribution, (n, scale_matrix)) + +#------------------------------------------------------------------------------- +# Matrix Normal distribution --------------------------------------------------- + +class MatrixNormalDistribution(MatrixDistribution): + + _argnames = ('location_matrix', 'scale_matrix_1', 'scale_matrix_2') + + @staticmethod + def check(location_matrix, scale_matrix_1, scale_matrix_2): + if not isinstance(scale_matrix_1, MatrixSymbol): + _value_check(scale_matrix_1.is_positive_definite, "The shape " + "matrix must be positive definite.") + if not isinstance(scale_matrix_2, MatrixSymbol): + _value_check(scale_matrix_2.is_positive_definite, "The shape " + "matrix must be positive definite.") + _value_check(scale_matrix_1.is_square, "Scale matrix 1 should be " + "be square matrix") + _value_check(scale_matrix_2.is_square, "Scale matrix 2 should be " + "be square matrix") + n = location_matrix.shape[0] + p = location_matrix.shape[1] + _value_check(scale_matrix_1.shape[0] == n, "Scale matrix 1 should be" + " of shape %s x %s"% (str(n), str(n))) + _value_check(scale_matrix_2.shape[0] == p, "Scale matrix 2 should be" + " of shape %s x %s"% (str(p), str(p))) + + @property + def set(self): + n, p = self.location_matrix.shape + return MatrixSet(n, p, S.Reals) + + @property + def dimension(self): + return self.location_matrix.shape + + def pdf(self, x): + M, U, V = self.location_matrix, self.scale_matrix_1, self.scale_matrix_2 + n, p = M.shape + if isinstance(x, list): + x = ImmutableMatrix(x) + if not isinstance(x, (MatrixBase, MatrixSymbol)): + raise ValueError("%s should be an isinstance of Matrix " + "or MatrixSymbol" % str(x)) + term1 = Inverse(V)*Transpose(x - M)*Inverse(U)*(x - M) + num = exp(-Trace(term1)/S(2)) + den = (2*pi)**(S(n*p)/2) * Determinant(U)**(S(p)/2) * Determinant(V)**(S(n)/2) + return num/den + +def MatrixNormal(symbol, location_matrix, scale_matrix_1, scale_matrix_2): + """ + Creates a random variable with Matrix Normal Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + location_matrix: Real ``n x p`` matrix + Represents degrees of freedom + scale_matrix_1: Positive definite matrix + Scale Matrix of shape ``n x n`` + scale_matrix_2: Positive definite matrix + Scale Matrix of shape ``p x p`` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy import MatrixSymbol + >>> from sympy.stats import density, MatrixNormal + >>> M = MatrixNormal('M', [[1, 2]], [1], [[1, 0], [0, 1]]) + >>> X = MatrixSymbol('X', 1, 2) + >>> density(M)(X).doit() + exp(-Trace((Matrix([ + [-1], + [-2]]) + X.T)*(Matrix([[-1, -2]]) + X))/2)/(2*pi) + >>> density(M)([[3, 4]]).doit() + exp(-4)/(2*pi) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Matrix_normal_distribution + + """ + if isinstance(location_matrix, list): + location_matrix = ImmutableMatrix(location_matrix) + if isinstance(scale_matrix_1, list): + scale_matrix_1 = ImmutableMatrix(scale_matrix_1) + if isinstance(scale_matrix_2, list): + scale_matrix_2 = ImmutableMatrix(scale_matrix_2) + args = (location_matrix, scale_matrix_1, scale_matrix_2) + return rv(symbol, MatrixNormalDistribution, args) + +#------------------------------------------------------------------------------- +# Matrix Student's T distribution --------------------------------------------------- + +class MatrixStudentTDistribution(MatrixDistribution): + + _argnames = ('nu', 'location_matrix', 'scale_matrix_1', 'scale_matrix_2') + + @staticmethod + def check(nu, location_matrix, scale_matrix_1, scale_matrix_2): + if not isinstance(scale_matrix_1, MatrixSymbol): + _value_check(scale_matrix_1.is_positive_definite != False, "The shape " + "matrix must be positive definite.") + if not isinstance(scale_matrix_2, MatrixSymbol): + _value_check(scale_matrix_2.is_positive_definite != False, "The shape " + "matrix must be positive definite.") + _value_check(scale_matrix_1.is_square != False, "Scale matrix 1 should be " + "be square matrix") + _value_check(scale_matrix_2.is_square != False, "Scale matrix 2 should be " + "be square matrix") + n = location_matrix.shape[0] + p = location_matrix.shape[1] + _value_check(scale_matrix_1.shape[0] == p, "Scale matrix 1 should be" + " of shape %s x %s" % (str(p), str(p))) + _value_check(scale_matrix_2.shape[0] == n, "Scale matrix 2 should be" + " of shape %s x %s" % (str(n), str(n))) + _value_check(nu.is_positive != False, "Degrees of freedom must be positive") + + @property + def set(self): + n, p = self.location_matrix.shape + return MatrixSet(n, p, S.Reals) + + @property + def dimension(self): + return self.location_matrix.shape + + def pdf(self, x): + from sympy.matrices.dense import eye + if isinstance(x, list): + x = ImmutableMatrix(x) + if not isinstance(x, (MatrixBase, MatrixSymbol)): + raise ValueError("%s should be an isinstance of Matrix " + "or MatrixSymbol" % str(x)) + nu, M, Omega, Sigma = self.nu, self.location_matrix, self.scale_matrix_1, self.scale_matrix_2 + n, p = M.shape + + K = multigamma((nu + n + p - 1)/2, p) * Determinant(Omega)**(-n/2) * Determinant(Sigma)**(-p/2) \ + / ((pi)**(n*p/2) * multigamma((nu + p - 1)/2, p)) + return K * (Determinant(eye(n) + Inverse(Sigma)*(x - M)*Inverse(Omega)*Transpose(x - M))) \ + **(-(nu + n + p -1)/2) + + + +def MatrixStudentT(symbol, nu, location_matrix, scale_matrix_1, scale_matrix_2): + """ + Creates a random variable with Matrix Gamma Distribution. + + The density of the said distribution can be found at [1]. + + Parameters + ========== + + nu: Positive Real number + degrees of freedom + location_matrix: Positive definite real square matrix + Location Matrix of shape ``n x p`` + scale_matrix_1: Positive definite real square matrix + Scale Matrix of shape ``p x p`` + scale_matrix_2: Positive definite real square matrix + Scale Matrix of shape ``n x n`` + + Returns + ======= + + RandomSymbol + + Examples + ======== + + >>> from sympy import MatrixSymbol,symbols + >>> from sympy.stats import density, MatrixStudentT + >>> v = symbols('v',positive=True) + >>> M = MatrixStudentT('M', v, [[1, 2]], [[1, 0], [0, 1]], [1]) + >>> X = MatrixSymbol('X', 1, 2) + >>> density(M)(X) + gamma(v/2 + 1)*Determinant((Matrix([[-1, -2]]) + X)*(Matrix([ + [-1], + [-2]]) + X.T) + Matrix([[1]]))**(-v/2 - 1)/(pi**1.0*gamma(v/2)*Determinant(Matrix([[1]]))**1.0*Determinant(Matrix([ + [1, 0], + [0, 1]]))**0.5) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Matrix_t-distribution + + """ + if isinstance(location_matrix, list): + location_matrix = ImmutableMatrix(location_matrix) + if isinstance(scale_matrix_1, list): + scale_matrix_1 = ImmutableMatrix(scale_matrix_1) + if isinstance(scale_matrix_2, list): + scale_matrix_2 = ImmutableMatrix(scale_matrix_2) + args = (nu, location_matrix, scale_matrix_1, scale_matrix_2) + return rv(symbol, MatrixStudentTDistribution, args) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/random_matrix.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/random_matrix.py new file mode 100644 index 0000000000000000000000000000000000000000..fdd25cb9ad23fed9d3a85982b24bef33d04928f0 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/random_matrix.py @@ -0,0 +1,30 @@ +from sympy.core.basic import Basic +from sympy.stats.rv import PSpace, _symbol_converter, RandomMatrixSymbol + +class RandomMatrixPSpace(PSpace): + """ + Represents probability space for + random matrices. It contains the mechanics + for handling the API calls for random matrices. + """ + def __new__(cls, sym, model=None): + sym = _symbol_converter(sym) + if model: + return Basic.__new__(cls, sym, model) + else: + return Basic.__new__(cls, sym) + + @property + def model(self): + try: + return self.args[1] + except IndexError: + return None + + def compute_density(self, expr, *args): + rms = expr.atoms(RandomMatrixSymbol) + if len(rms) > 2 or (not isinstance(expr, RandomMatrixSymbol)): + raise NotImplementedError("Currently, no algorithm has been " + "implemented to handle general expressions containing " + "multiple random matrices.") + return self.model.density(expr) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/random_matrix_models.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/random_matrix_models.py new file mode 100644 index 0000000000000000000000000000000000000000..6327a248ea5919c0bbb0ffc2c984105e04fe20e9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/random_matrix_models.py @@ -0,0 +1,457 @@ +from sympy.concrete.products import Product +from sympy.concrete.summations import Sum +from sympy.core.basic import Basic +from sympy.core.function import Lambda +from sympy.core.numbers import (I, pi) +from sympy.core.singleton import S +from sympy.core.symbol import Dummy +from sympy.functions.elementary.complexes import Abs +from sympy.functions.elementary.exponential import exp +from sympy.functions.special.gamma_functions import gamma +from sympy.integrals.integrals import Integral +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.trace import Trace +from sympy.tensor.indexed import IndexedBase +from sympy.core.sympify import _sympify +from sympy.stats.rv import _symbol_converter, Density, RandomMatrixSymbol, is_random +from sympy.stats.joint_rv_types import JointDistributionHandmade +from sympy.stats.random_matrix import RandomMatrixPSpace +from sympy.tensor.array import ArrayComprehension + +__all__ = [ + 'CircularEnsemble', + 'CircularUnitaryEnsemble', + 'CircularOrthogonalEnsemble', + 'CircularSymplecticEnsemble', + 'GaussianEnsemble', + 'GaussianUnitaryEnsemble', + 'GaussianOrthogonalEnsemble', + 'GaussianSymplecticEnsemble', + 'joint_eigen_distribution', + 'JointEigenDistribution', + 'level_spacing_distribution' +] + +@is_random.register(RandomMatrixSymbol) +def _(x): + return True + + +class RandomMatrixEnsembleModel(Basic): + """ + Base class for random matrix ensembles. + It acts as an umbrella and contains + the methods common to all the ensembles + defined in sympy.stats.random_matrix_models. + """ + def __new__(cls, sym, dim=None): + sym, dim = _symbol_converter(sym), _sympify(dim) + if dim.is_integer == False: + raise ValueError("Dimension of the random matrices must be " + "integers, received %s instead."%(dim)) + return Basic.__new__(cls, sym, dim) + + symbol = property(lambda self: self.args[0]) + dimension = property(lambda self: self.args[1]) + + def density(self, expr): + return Density(expr) + + def __call__(self, expr): + return self.density(expr) + +class GaussianEnsembleModel(RandomMatrixEnsembleModel): + """ + Abstract class for Gaussian ensembles. + Contains the properties common to all the + gaussian ensembles. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Random_matrix#Gaussian_ensembles + .. [2] https://arxiv.org/pdf/1712.07903.pdf + """ + def _compute_normalization_constant(self, beta, n): + """ + Helper function for computing normalization + constant for joint probability density of eigen + values of Gaussian ensembles. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Selberg_integral#Mehta's_integral + """ + n = S(n) + prod_term = lambda j: gamma(1 + beta*S(j)/2)/gamma(S.One + beta/S(2)) + j = Dummy('j', integer=True, positive=True) + term1 = Product(prod_term(j), (j, 1, n)).doit() + term2 = (2/(beta*n))**(beta*n*(n - 1)/4 + n/2) + term3 = (2*pi)**(n/2) + return term1 * term2 * term3 + + def _compute_joint_eigen_distribution(self, beta): + """ + Helper function for computing the joint + probability distribution of eigen values + of the random matrix. + """ + n = self.dimension + Zbn = self._compute_normalization_constant(beta, n) + l = IndexedBase('l') + i = Dummy('i', integer=True, positive=True) + j = Dummy('j', integer=True, positive=True) + k = Dummy('k', integer=True, positive=True) + term1 = exp((-S(n)/2) * Sum(l[k]**2, (k, 1, n)).doit()) + sub_term = Lambda(i, Product(Abs(l[j] - l[i])**beta, (j, i + 1, n))) + term2 = Product(sub_term(i).doit(), (i, 1, n - 1)).doit() + syms = ArrayComprehension(l[k], (k, 1, n)).doit() + return Lambda(tuple(syms), (term1 * term2)/Zbn) + +class GaussianUnitaryEnsembleModel(GaussianEnsembleModel): + @property + def normalization_constant(self): + n = self.dimension + return 2**(S(n)/2) * pi**(S(n**2)/2) + + def density(self, expr): + n, ZGUE = self.dimension, self.normalization_constant + h_pspace = RandomMatrixPSpace('P', model=self) + H = RandomMatrixSymbol('H', n, n, pspace=h_pspace) + return Lambda(H, exp(-S(n)/2 * Trace(H**2))/ZGUE)(expr) + + def joint_eigen_distribution(self): + return self._compute_joint_eigen_distribution(S(2)) + + def level_spacing_distribution(self): + s = Dummy('s') + f = (32/pi**2)*(s**2)*exp((-4/pi)*s**2) + return Lambda(s, f) + +class GaussianOrthogonalEnsembleModel(GaussianEnsembleModel): + @property + def normalization_constant(self): + n = self.dimension + _H = MatrixSymbol('_H', n, n) + return Integral(exp(-S(n)/4 * Trace(_H**2))) + + def density(self, expr): + n, ZGOE = self.dimension, self.normalization_constant + h_pspace = RandomMatrixPSpace('P', model=self) + H = RandomMatrixSymbol('H', n, n, pspace=h_pspace) + return Lambda(H, exp(-S(n)/4 * Trace(H**2))/ZGOE)(expr) + + def joint_eigen_distribution(self): + return self._compute_joint_eigen_distribution(S.One) + + def level_spacing_distribution(self): + s = Dummy('s') + f = (pi/2)*s*exp((-pi/4)*s**2) + return Lambda(s, f) + +class GaussianSymplecticEnsembleModel(GaussianEnsembleModel): + @property + def normalization_constant(self): + n = self.dimension + _H = MatrixSymbol('_H', n, n) + return Integral(exp(-S(n) * Trace(_H**2))) + + def density(self, expr): + n, ZGSE = self.dimension, self.normalization_constant + h_pspace = RandomMatrixPSpace('P', model=self) + H = RandomMatrixSymbol('H', n, n, pspace=h_pspace) + return Lambda(H, exp(-S(n) * Trace(H**2))/ZGSE)(expr) + + def joint_eigen_distribution(self): + return self._compute_joint_eigen_distribution(S(4)) + + def level_spacing_distribution(self): + s = Dummy('s') + f = ((S(2)**18)/((S(3)**6)*(pi**3)))*(s**4)*exp((-64/(9*pi))*s**2) + return Lambda(s, f) + +def GaussianEnsemble(sym, dim): + sym, dim = _symbol_converter(sym), _sympify(dim) + model = GaussianEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def GaussianUnitaryEnsemble(sym, dim): + """ + Represents Gaussian Unitary Ensembles. + + Examples + ======== + + >>> from sympy.stats import GaussianUnitaryEnsemble as GUE, density + >>> from sympy import MatrixSymbol + >>> G = GUE('U', 2) + >>> X = MatrixSymbol('X', 2, 2) + >>> density(G)(X) + exp(-Trace(X**2))/(2*pi**2) + """ + sym, dim = _symbol_converter(sym), _sympify(dim) + model = GaussianUnitaryEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def GaussianOrthogonalEnsemble(sym, dim): + """ + Represents Gaussian Orthogonal Ensembles. + + Examples + ======== + + >>> from sympy.stats import GaussianOrthogonalEnsemble as GOE, density + >>> from sympy import MatrixSymbol + >>> G = GOE('U', 2) + >>> X = MatrixSymbol('X', 2, 2) + >>> density(G)(X) + exp(-Trace(X**2)/2)/Integral(exp(-Trace(_H**2)/2), _H) + """ + sym, dim = _symbol_converter(sym), _sympify(dim) + model = GaussianOrthogonalEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def GaussianSymplecticEnsemble(sym, dim): + """ + Represents Gaussian Symplectic Ensembles. + + Examples + ======== + + >>> from sympy.stats import GaussianSymplecticEnsemble as GSE, density + >>> from sympy import MatrixSymbol + >>> G = GSE('U', 2) + >>> X = MatrixSymbol('X', 2, 2) + >>> density(G)(X) + exp(-2*Trace(X**2))/Integral(exp(-2*Trace(_H**2)), _H) + """ + sym, dim = _symbol_converter(sym), _sympify(dim) + model = GaussianSymplecticEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +class CircularEnsembleModel(RandomMatrixEnsembleModel): + """ + Abstract class for Circular ensembles. + Contains the properties and methods + common to all the circular ensembles. + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Circular_ensemble + """ + def density(self, expr): + # TODO : Add support for Lie groups(as extensions of sympy.diffgeom) + # and define measures on them + raise NotImplementedError("Support for Haar measure hasn't been " + "implemented yet, therefore the density of " + "%s cannot be computed."%(self)) + + def _compute_joint_eigen_distribution(self, beta): + """ + Helper function to compute the joint distribution of phases + of the complex eigen values of matrices belonging to any + circular ensembles. + """ + n = self.dimension + Zbn = ((2*pi)**n)*(gamma(beta*n/2 + 1)/S(gamma(beta/2 + 1))**n) + t = IndexedBase('t') + i, j, k = (Dummy('i', integer=True), Dummy('j', integer=True), + Dummy('k', integer=True)) + syms = ArrayComprehension(t[i], (i, 1, n)).doit() + f = Product(Product(Abs(exp(I*t[k]) - exp(I*t[j]))**beta, (j, k + 1, n)).doit(), + (k, 1, n - 1)).doit() + return Lambda(tuple(syms), f/Zbn) + +class CircularUnitaryEnsembleModel(CircularEnsembleModel): + def joint_eigen_distribution(self): + return self._compute_joint_eigen_distribution(S(2)) + +class CircularOrthogonalEnsembleModel(CircularEnsembleModel): + def joint_eigen_distribution(self): + return self._compute_joint_eigen_distribution(S.One) + +class CircularSymplecticEnsembleModel(CircularEnsembleModel): + def joint_eigen_distribution(self): + return self._compute_joint_eigen_distribution(S(4)) + +def CircularEnsemble(sym, dim): + sym, dim = _symbol_converter(sym), _sympify(dim) + model = CircularEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def CircularUnitaryEnsemble(sym, dim): + """ + Represents Circular Unitary Ensembles. + + Examples + ======== + + >>> from sympy.stats import CircularUnitaryEnsemble as CUE + >>> from sympy.stats import joint_eigen_distribution + >>> C = CUE('U', 1) + >>> joint_eigen_distribution(C) + Lambda(t[1], Product(Abs(exp(I*t[_j]) - exp(I*t[_k]))**2, (_j, _k + 1, 1), (_k, 1, 0))/(2*pi)) + + Note + ==== + + As can be seen above in the example, density of CiruclarUnitaryEnsemble + is not evaluated because the exact definition is based on haar measure of + unitary group which is not unique. + """ + sym, dim = _symbol_converter(sym), _sympify(dim) + model = CircularUnitaryEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def CircularOrthogonalEnsemble(sym, dim): + """ + Represents Circular Orthogonal Ensembles. + + Examples + ======== + + >>> from sympy.stats import CircularOrthogonalEnsemble as COE + >>> from sympy.stats import joint_eigen_distribution + >>> C = COE('O', 1) + >>> joint_eigen_distribution(C) + Lambda(t[1], Product(Abs(exp(I*t[_j]) - exp(I*t[_k])), (_j, _k + 1, 1), (_k, 1, 0))/(2*pi)) + + Note + ==== + + As can be seen above in the example, density of CiruclarOrthogonalEnsemble + is not evaluated because the exact definition is based on haar measure of + unitary group which is not unique. + """ + sym, dim = _symbol_converter(sym), _sympify(dim) + model = CircularOrthogonalEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def CircularSymplecticEnsemble(sym, dim): + """ + Represents Circular Symplectic Ensembles. + + Examples + ======== + + >>> from sympy.stats import CircularSymplecticEnsemble as CSE + >>> from sympy.stats import joint_eigen_distribution + >>> C = CSE('S', 1) + >>> joint_eigen_distribution(C) + Lambda(t[1], Product(Abs(exp(I*t[_j]) - exp(I*t[_k]))**4, (_j, _k + 1, 1), (_k, 1, 0))/(2*pi)) + + Note + ==== + + As can be seen above in the example, density of CiruclarSymplecticEnsemble + is not evaluated because the exact definition is based on haar measure of + unitary group which is not unique. + """ + sym, dim = _symbol_converter(sym), _sympify(dim) + model = CircularSymplecticEnsembleModel(sym, dim) + rmp = RandomMatrixPSpace(sym, model=model) + return RandomMatrixSymbol(sym, dim, dim, pspace=rmp) + +def joint_eigen_distribution(mat): + """ + For obtaining joint probability distribution + of eigen values of random matrix. + + Parameters + ========== + + mat: RandomMatrixSymbol + The matrix symbol whose eigen values are to be considered. + + Returns + ======= + + Lambda + + Examples + ======== + + >>> from sympy.stats import GaussianUnitaryEnsemble as GUE + >>> from sympy.stats import joint_eigen_distribution + >>> U = GUE('U', 2) + >>> joint_eigen_distribution(U) + Lambda((l[1], l[2]), exp(-l[1]**2 - l[2]**2)*Product(Abs(l[_i] - l[_j])**2, (_j, _i + 1, 2), (_i, 1, 1))/pi) + """ + if not isinstance(mat, RandomMatrixSymbol): + raise ValueError("%s is not of type, RandomMatrixSymbol."%(mat)) + return mat.pspace.model.joint_eigen_distribution() + +def JointEigenDistribution(mat): + """ + Creates joint distribution of eigen values of matrices with random + expressions. + + Parameters + ========== + + mat: Matrix + The matrix under consideration. + + Returns + ======= + + JointDistributionHandmade + + Examples + ======== + + >>> from sympy.stats import Normal, JointEigenDistribution + >>> from sympy import Matrix + >>> A = [[Normal('A00', 0, 1), Normal('A01', 0, 1)], + ... [Normal('A10', 0, 1), Normal('A11', 0, 1)]] + >>> JointEigenDistribution(Matrix(A)) + JointDistributionHandmade(-sqrt(A00**2 - 2*A00*A11 + 4*A01*A10 + A11**2)/2 + + A00/2 + A11/2, sqrt(A00**2 - 2*A00*A11 + 4*A01*A10 + A11**2)/2 + A00/2 + A11/2) + + """ + eigenvals = mat.eigenvals(multiple=True) + if not all(is_random(eigenval) for eigenval in set(eigenvals)): + raise ValueError("Eigen values do not have any random expression, " + "joint distribution cannot be generated.") + return JointDistributionHandmade(*eigenvals) + +def level_spacing_distribution(mat): + """ + For obtaining distribution of level spacings. + + Parameters + ========== + + mat: RandomMatrixSymbol + The random matrix symbol whose eigen values are + to be considered for finding the level spacings. + + Returns + ======= + + Lambda + + Examples + ======== + + >>> from sympy.stats import GaussianUnitaryEnsemble as GUE + >>> from sympy.stats import level_spacing_distribution + >>> U = GUE('U', 2) + >>> level_spacing_distribution(U) + Lambda(_s, 32*_s**2*exp(-4*_s**2/pi)/pi**2) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Random_matrix#Distribution_of_level_spacings + """ + return mat.pspace.model.level_spacing_distribution() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/rv.py new file mode 100644 index 0000000000000000000000000000000000000000..75ab54deb551b7ff3d4d06f37482a1f16a789ba6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/rv.py @@ -0,0 +1,1798 @@ +""" +Main Random Variables Module + +Defines abstract random variable type. +Contains interfaces for probability space object (PSpace) as well as standard +operators, P, E, sample, density, where, quantile + +See Also +======== + +sympy.stats.crv +sympy.stats.frv +sympy.stats.rv_interface +""" + +from __future__ import annotations +from functools import singledispatch +from math import prod + +from sympy.core.add import Add +from sympy.core.basic import Basic +from sympy.core.containers import Tuple +from sympy.core.expr import Expr +from sympy.core.function import (Function, Lambda) +from sympy.core.logic import fuzzy_and +from sympy.core.mul import Mul +from sympy.core.relational import (Eq, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol) +from sympy.core.sympify import sympify +from sympy.functions.special.delta_functions import DiracDelta +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.logic.boolalg import (And, Or) +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.tensor.indexed import Indexed +from sympy.utilities.lambdify import lambdify +from sympy.core.relational import Relational +from sympy.core.sympify import _sympify +from sympy.sets.sets import FiniteSet, ProductSet, Intersection +from sympy.solvers.solveset import solveset +from sympy.external import import_module +from sympy.utilities.decorator import doctest_depends_on +from sympy.utilities.exceptions import sympy_deprecation_warning +from sympy.utilities.iterables import iterable + + +__doctest_requires__ = {('sample',): ['scipy']} + + +x = Symbol('x') + + +@singledispatch +def is_random(x): + return False + + +@is_random.register(Basic) +def _(x): + atoms = x.free_symbols + return any(is_random(i) for i in atoms) + + +class RandomDomain(Basic): + """ + Represents a set of variables and the values which they can take. + + See Also + ======== + + sympy.stats.crv.ContinuousDomain + sympy.stats.frv.FiniteDomain + """ + + is_ProductDomain = False + is_Finite = False + is_Continuous = False + is_Discrete = False + + def __new__(cls, symbols, *args): + symbols = FiniteSet(*symbols) + return Basic.__new__(cls, symbols, *args) + + @property + def symbols(self): + return self.args[0] + + @property + def set(self): + return self.args[1] + + def __contains__(self, other): + raise NotImplementedError() + + def compute_expectation(self, expr): + raise NotImplementedError() + + +class SingleDomain(RandomDomain): + """ + A single variable and its domain. + + See Also + ======== + + sympy.stats.crv.SingleContinuousDomain + sympy.stats.frv.SingleFiniteDomain + """ + def __new__(cls, symbol, set): + assert symbol.is_Symbol + return Basic.__new__(cls, symbol, set) + + @property + def symbol(self): + return self.args[0] + + @property + def symbols(self): + return FiniteSet(self.symbol) + + def __contains__(self, other): + if len(other) != 1: + return False + sym, val = tuple(other)[0] + return self.symbol == sym and val in self.set + + +class MatrixDomain(RandomDomain): + """ + A Random Matrix variable and its domain. + + """ + def __new__(cls, symbol, set): + symbol, set = _symbol_converter(symbol), _sympify(set) + return Basic.__new__(cls, symbol, set) + + @property + def symbol(self): + return self.args[0] + + @property + def symbols(self): + return FiniteSet(self.symbol) + + +class ConditionalDomain(RandomDomain): + """ + A RandomDomain with an attached condition. + + See Also + ======== + + sympy.stats.crv.ConditionalContinuousDomain + sympy.stats.frv.ConditionalFiniteDomain + """ + def __new__(cls, fulldomain, condition): + condition = condition.xreplace({rs: rs.symbol + for rs in random_symbols(condition)}) + return Basic.__new__(cls, fulldomain, condition) + + @property + def symbols(self): + return self.fulldomain.symbols + + @property + def fulldomain(self): + return self.args[0] + + @property + def condition(self): + return self.args[1] + + @property + def set(self): + raise NotImplementedError("Set of Conditional Domain not Implemented") + + def as_boolean(self): + return And(self.fulldomain.as_boolean(), self.condition) + + +class PSpace(Basic): + """ + A Probability Space. + + Explanation + =========== + + Probability Spaces encode processes that equal different values + probabilistically. These underly Random Symbols which occur in SymPy + expressions and contain the mechanics to evaluate statistical statements. + + See Also + ======== + + sympy.stats.crv.ContinuousPSpace + sympy.stats.frv.FinitePSpace + """ + + is_Finite: bool | None = None # Fails test if not set to None + is_Continuous: bool | None = None # Fails test if not set to None + is_Discrete: bool | None = None # Fails test if not set to None + is_real: bool | None + + @property + def domain(self): + return self.args[0] + + @property + def density(self): + return self.args[1] + + @property + def values(self): + return frozenset(RandomSymbol(sym, self) for sym in self.symbols) + + @property + def symbols(self): + return self.domain.symbols + + def where(self, condition): + raise NotImplementedError() + + def compute_density(self, expr): + raise NotImplementedError() + + def sample(self, size=(), library='scipy', seed=None): + raise NotImplementedError() + + def probability(self, condition): + raise NotImplementedError() + + def compute_expectation(self, expr): + raise NotImplementedError() + + +class SinglePSpace(PSpace): + """ + Represents the probabilities of a set of random events that can be + attributed to a single variable/symbol. + """ + def __new__(cls, s, distribution): + s = _symbol_converter(s) + return Basic.__new__(cls, s, distribution) + + @property + def value(self): + return RandomSymbol(self.symbol, self) + + @property + def symbol(self): + return self.args[0] + + @property + def distribution(self): + return self.args[1] + + @property + def pdf(self): + return self.distribution.pdf(self.symbol) + + +class RandomSymbol(Expr): + """ + Random Symbols represent ProbabilitySpaces in SymPy Expressions. + In principle they can take on any value that their symbol can take on + within the associated PSpace with probability determined by the PSpace + Density. + + Explanation + =========== + + Random Symbols contain pspace and symbol properties. + The pspace property points to the represented Probability Space + The symbol is a standard SymPy Symbol that is used in that probability space + for example in defining a density. + + You can form normal SymPy expressions using RandomSymbols and operate on + those expressions with the Functions + + E - Expectation of a random expression + P - Probability of a condition + density - Probability Density of an expression + given - A new random expression (with new random symbols) given a condition + + An object of the RandomSymbol type should almost never be created by the + user. They tend to be created instead by the PSpace class's value method. + Traditionally a user does not even do this but instead calls one of the + convenience functions Normal, Exponential, Coin, Die, FiniteRV, etc.... + """ + + def __new__(cls, symbol, pspace=None): + from sympy.stats.joint_rv import JointRandomSymbol + if pspace is None: + # Allow single arg, representing pspace == PSpace() + pspace = PSpace() + symbol = _symbol_converter(symbol) + if not isinstance(pspace, PSpace): + raise TypeError("pspace variable should be of type PSpace") + if cls == JointRandomSymbol and isinstance(pspace, SinglePSpace): + cls = RandomSymbol + return Basic.__new__(cls, symbol, pspace) + + is_finite = True + is_symbol = True + is_Atom = True + + _diff_wrt = True + + pspace = property(lambda self: self.args[1]) + symbol = property(lambda self: self.args[0]) + name = property(lambda self: self.symbol.name) + + def _eval_is_positive(self): + return self.symbol.is_positive + + def _eval_is_integer(self): + return self.symbol.is_integer + + def _eval_is_real(self): + return self.symbol.is_real or self.pspace.is_real + + @property + def is_commutative(self): + return self.symbol.is_commutative + + @property + def free_symbols(self): + return {self} + +class RandomIndexedSymbol(RandomSymbol): + + def __new__(cls, idx_obj, pspace=None): + if pspace is None: + # Allow single arg, representing pspace == PSpace() + pspace = PSpace() + if not isinstance(idx_obj, (Indexed, Function)): + raise TypeError("An Function or Indexed object is expected not %s"%(idx_obj)) + return Basic.__new__(cls, idx_obj, pspace) + + symbol = property(lambda self: self.args[0]) + name = property(lambda self: str(self.args[0])) + + @property + def key(self): + if isinstance(self.symbol, Indexed): + return self.symbol.args[1] + elif isinstance(self.symbol, Function): + return self.symbol.args[0] + + @property + def free_symbols(self): + if self.key.free_symbols: + free_syms = self.key.free_symbols + free_syms.add(self) + return free_syms + return {self} + + @property + def pspace(self): + return self.args[1] + +class RandomMatrixSymbol(RandomSymbol, MatrixSymbol): # type: ignore + def __new__(cls, symbol, n, m, pspace=None): + n, m = _sympify(n), _sympify(m) + symbol = _symbol_converter(symbol) + if pspace is None: + # Allow single arg, representing pspace == PSpace() + pspace = PSpace() + return Basic.__new__(cls, symbol, n, m, pspace) + + symbol = property(lambda self: self.args[0]) + pspace = property(lambda self: self.args[3]) + + +class ProductPSpace(PSpace): + """ + Abstract class for representing probability spaces with multiple random + variables. + + See Also + ======== + + sympy.stats.rv.IndependentProductPSpace + sympy.stats.joint_rv.JointPSpace + """ + pass + +class IndependentProductPSpace(ProductPSpace): + """ + A probability space resulting from the merger of two independent probability + spaces. + + Often created using the function, pspace. + """ + + def __new__(cls, *spaces): + rs_space_dict = {} + for space in spaces: + for value in space.values: + rs_space_dict[value] = space + + symbols = FiniteSet(*[val.symbol for val in rs_space_dict.keys()]) + + # Overlapping symbols + from sympy.stats.joint_rv import MarginalDistribution + from sympy.stats.compound_rv import CompoundDistribution + if len(symbols) < sum(len(space.symbols) for space in spaces if not + isinstance(space.distribution, ( + CompoundDistribution, MarginalDistribution))): + raise ValueError("Overlapping Random Variables") + + if all(space.is_Finite for space in spaces): + from sympy.stats.frv import ProductFinitePSpace + cls = ProductFinitePSpace + + obj = Basic.__new__(cls, *FiniteSet(*spaces)) + + return obj + + @property + def pdf(self): + p = Mul(*[space.pdf for space in self.spaces]) + return p.subs({rv: rv.symbol for rv in self.values}) + + @property + def rs_space_dict(self): + d = {} + for space in self.spaces: + for value in space.values: + d[value] = space + return d + + @property + def symbols(self): + return FiniteSet(*[val.symbol for val in self.rs_space_dict.keys()]) + + @property + def spaces(self): + return FiniteSet(*self.args) + + @property + def values(self): + return sumsets(space.values for space in self.spaces) + + def compute_expectation(self, expr, rvs=None, evaluate=False, **kwargs): + rvs = rvs or self.values + rvs = frozenset(rvs) + for space in self.spaces: + expr = space.compute_expectation(expr, rvs & space.values, evaluate=False, **kwargs) + if evaluate and hasattr(expr, 'doit'): + return expr.doit(**kwargs) + return expr + + @property + def domain(self): + return ProductDomain(*[space.domain for space in self.spaces]) + + @property + def density(self): + raise NotImplementedError("Density not available for ProductSpaces") + + def sample(self, size=(), library='scipy', seed=None): + return {k: v for space in self.spaces + for k, v in space.sample(size=size, library=library, seed=seed).items()} + + + def probability(self, condition, **kwargs): + cond_inv = False + if isinstance(condition, Ne): + condition = Eq(condition.args[0], condition.args[1]) + cond_inv = True + elif isinstance(condition, And): # they are independent + return Mul(*[self.probability(arg) for arg in condition.args]) + elif isinstance(condition, Or): # they are independent + return Add(*[self.probability(arg) for arg in condition.args]) + expr = condition.lhs - condition.rhs + rvs = random_symbols(expr) + dens = self.compute_density(expr) + if any(pspace(rv).is_Continuous for rv in rvs): + from sympy.stats.crv import SingleContinuousPSpace + from sympy.stats.crv_types import ContinuousDistributionHandmade + if expr in self.values: + # Marginalize all other random symbols out of the density + randomsymbols = tuple(set(self.values) - frozenset([expr])) + symbols = tuple(rs.symbol for rs in randomsymbols) + pdf = self.domain.integrate(self.pdf, symbols, **kwargs) + return Lambda(expr.symbol, pdf) + dens = ContinuousDistributionHandmade(dens) + z = Dummy('z', real=True) + space = SingleContinuousPSpace(z, dens) + result = space.probability(condition.__class__(space.value, 0)) + else: + from sympy.stats.drv import SingleDiscretePSpace + from sympy.stats.drv_types import DiscreteDistributionHandmade + dens = DiscreteDistributionHandmade(dens) + z = Dummy('z', integer=True) + space = SingleDiscretePSpace(z, dens) + result = space.probability(condition.__class__(space.value, 0)) + return result if not cond_inv else S.One - result + + def compute_density(self, expr, **kwargs): + rvs = random_symbols(expr) + if any(pspace(rv).is_Continuous for rv in rvs): + z = Dummy('z', real=True) + expr = self.compute_expectation(DiracDelta(expr - z), + **kwargs) + else: + z = Dummy('z', integer=True) + expr = self.compute_expectation(KroneckerDelta(expr, z), + **kwargs) + return Lambda(z, expr) + + def compute_cdf(self, expr, **kwargs): + raise ValueError("CDF not well defined on multivariate expressions") + + def conditional_space(self, condition, normalize=True, **kwargs): + rvs = random_symbols(condition) + condition = condition.xreplace({rv: rv.symbol for rv in self.values}) + pspaces = [pspace(rv) for rv in rvs] + if any(ps.is_Continuous for ps in pspaces): + from sympy.stats.crv import (ConditionalContinuousDomain, + ContinuousPSpace) + space = ContinuousPSpace + domain = ConditionalContinuousDomain(self.domain, condition) + elif any(ps.is_Discrete for ps in pspaces): + from sympy.stats.drv import (ConditionalDiscreteDomain, + DiscretePSpace) + space = DiscretePSpace + domain = ConditionalDiscreteDomain(self.domain, condition) + elif all(ps.is_Finite for ps in pspaces): + from sympy.stats.frv import FinitePSpace + return FinitePSpace.conditional_space(self, condition) + if normalize: + replacement = {rv: Dummy(str(rv)) for rv in self.symbols} + norm = domain.compute_expectation(self.pdf, **kwargs) + pdf = self.pdf / norm.xreplace(replacement) + # XXX: Converting symbols from set to tuple. The order matters to + # Lambda though so we shouldn't be starting with a set here... + density = Lambda(tuple(domain.symbols), pdf) + + return space(domain, density) + +class ProductDomain(RandomDomain): + """ + A domain resulting from the merger of two independent domains. + + See Also + ======== + sympy.stats.crv.ProductContinuousDomain + sympy.stats.frv.ProductFiniteDomain + """ + is_ProductDomain = True + + def __new__(cls, *domains): + # Flatten any product of products + domains2 = [] + for domain in domains: + if not domain.is_ProductDomain: + domains2.append(domain) + else: + domains2.extend(domain.domains) + domains2 = FiniteSet(*domains2) + + if all(domain.is_Finite for domain in domains2): + from sympy.stats.frv import ProductFiniteDomain + cls = ProductFiniteDomain + if all(domain.is_Continuous for domain in domains2): + from sympy.stats.crv import ProductContinuousDomain + cls = ProductContinuousDomain + if all(domain.is_Discrete for domain in domains2): + from sympy.stats.drv import ProductDiscreteDomain + cls = ProductDiscreteDomain + + return Basic.__new__(cls, *domains2) + + @property + def sym_domain_dict(self): + return {symbol: domain for domain in self.domains + for symbol in domain.symbols} + + @property + def symbols(self): + return FiniteSet(*[sym for domain in self.domains + for sym in domain.symbols]) + + @property + def domains(self): + return self.args + + @property + def set(self): + return ProductSet(*(domain.set for domain in self.domains)) + + def __contains__(self, other): + # Split event into each subdomain + for domain in self.domains: + # Collect the parts of this event which associate to this domain + elem = frozenset([item for item in other + if sympify(domain.symbols.contains(item[0])) + is S.true]) + # Test this sub-event + if elem not in domain: + return False + # All subevents passed + return True + + def as_boolean(self): + return And(*[domain.as_boolean() for domain in self.domains]) + + +def random_symbols(expr): + """ + Returns all RandomSymbols within a SymPy Expression. + """ + atoms = getattr(expr, 'atoms', None) + if atoms is not None: + comp = lambda rv: rv.symbol.name + l = list(atoms(RandomSymbol)) + return sorted(l, key=comp) + else: + return [] + + +def pspace(expr): + """ + Returns the underlying Probability Space of a random expression. + + For internal use. + + Examples + ======== + + >>> from sympy.stats import pspace, Normal + >>> X = Normal('X', 0, 1) + >>> pspace(2*X + 1) == X.pspace + True + """ + expr = sympify(expr) + if isinstance(expr, RandomSymbol) and expr.pspace is not None: + return expr.pspace + if expr.has(RandomMatrixSymbol): + rm = list(expr.atoms(RandomMatrixSymbol))[0] + return rm.pspace + + rvs = random_symbols(expr) + if not rvs: + raise ValueError("Expression containing Random Variable expected, not %s" % (expr)) + # If only one space present + if all(rv.pspace == rvs[0].pspace for rv in rvs): + return rvs[0].pspace + from sympy.stats.compound_rv import CompoundPSpace + from sympy.stats.stochastic_process import StochasticPSpace + for rv in rvs: + if isinstance(rv.pspace, (CompoundPSpace, StochasticPSpace)): + return rv.pspace + # Otherwise make a product space + return IndependentProductPSpace(*[rv.pspace for rv in rvs]) + + +def sumsets(sets): + """ + Union of sets + """ + return frozenset().union(*sets) + + +def rs_swap(a, b): + """ + Build a dictionary to swap RandomSymbols based on their underlying symbol. + + i.e. + if ``X = ('x', pspace1)`` + and ``Y = ('x', pspace2)`` + then ``X`` and ``Y`` match and the key, value pair + ``{X:Y}`` will appear in the result + + Inputs: collections a and b of random variables which share common symbols + Output: dict mapping RVs in a to RVs in b + """ + d = {} + for rsa in a: + d[rsa] = [rsb for rsb in b if rsa.symbol == rsb.symbol][0] + return d + + +def given(expr, condition=None, **kwargs): + r""" Conditional Random Expression. + + Explanation + =========== + + From a random expression and a condition on that expression creates a new + probability space from the condition and returns the same expression on that + conditional probability space. + + Examples + ======== + + >>> from sympy.stats import given, density, Die + >>> X = Die('X', 6) + >>> Y = given(X, X > 3) + >>> density(Y).dict + {4: 1/3, 5: 1/3, 6: 1/3} + + Following convention, if the condition is a random symbol then that symbol + is considered fixed. + + >>> from sympy.stats import Normal + >>> from sympy import pprint + >>> from sympy.abc import z + + >>> X = Normal('X', 0, 1) + >>> Y = Normal('Y', 0, 1) + >>> pprint(density(X + Y, Y)(z), use_unicode=False) + 2 + -(-Y + z) + ----------- + ___ 2 + \/ 2 *e + ------------------ + ____ + 2*\/ pi + """ + + if not is_random(condition) or pspace_independent(expr, condition): + return expr + + if isinstance(condition, RandomSymbol): + condition = Eq(condition, condition.symbol) + + condsymbols = random_symbols(condition) + if (isinstance(condition, Eq) and len(condsymbols) == 1 and + not isinstance(pspace(expr).domain, ConditionalDomain)): + rv = tuple(condsymbols)[0] + + results = solveset(condition, rv) + if isinstance(results, Intersection) and S.Reals in results.args: + results = list(results.args[1]) + + sums = 0 + for res in results: + temp = expr.subs(rv, res) + if temp == True: + return True + if temp != False: + # XXX: This seems nonsensical but preserves existing behaviour + # after the change that Relational is no longer a subclass of + # Expr. Here expr is sometimes Relational and sometimes Expr + # but we are trying to add them with +=. This needs to be + # fixed somehow. + if sums == 0 and isinstance(expr, Relational): + sums = expr.subs(rv, res) + else: + sums += expr.subs(rv, res) + if sums == 0: + return False + return sums + + # Get full probability space of both the expression and the condition + fullspace = pspace(Tuple(expr, condition)) + # Build new space given the condition + space = fullspace.conditional_space(condition, **kwargs) + # Dictionary to swap out RandomSymbols in expr with new RandomSymbols + # That point to the new conditional space + swapdict = rs_swap(fullspace.values, space.values) + # Swap random variables in the expression + expr = expr.xreplace(swapdict) + return expr + + +def expectation(expr, condition=None, numsamples=None, evaluate=True, **kwargs): + """ + Returns the expected value of a random expression. + + Parameters + ========== + + expr : Expr containing RandomSymbols + The expression of which you want to compute the expectation value + given : Expr containing RandomSymbols + A conditional expression. E(X, X>0) is expectation of X given X > 0 + numsamples : int + Enables sampling and approximates the expectation with this many samples + evalf : Bool (defaults to True) + If sampling return a number rather than a complex expression + evaluate : Bool (defaults to True) + In case of continuous systems return unevaluated integral + + Examples + ======== + + >>> from sympy.stats import E, Die + >>> X = Die('X', 6) + >>> E(X) + 7/2 + >>> E(2*X + 1) + 8 + + >>> E(X, X > 3) # Expectation of X given that it is above 3 + 5 + """ + + if not is_random(expr): # expr isn't random? + return expr + kwargs['numsamples'] = numsamples + from sympy.stats.symbolic_probability import Expectation + if evaluate: + return Expectation(expr, condition).doit(**kwargs) + return Expectation(expr, condition) + + +def probability(condition, given_condition=None, numsamples=None, + evaluate=True, **kwargs): + """ + Probability that a condition is true, optionally given a second condition. + + Parameters + ========== + + condition : Combination of Relationals containing RandomSymbols + The condition of which you want to compute the probability + given_condition : Combination of Relationals containing RandomSymbols + A conditional expression. P(X > 1, X > 0) is expectation of X > 1 + given X > 0 + numsamples : int + Enables sampling and approximates the probability with this many samples + evaluate : Bool (defaults to True) + In case of continuous systems return unevaluated integral + + Examples + ======== + + >>> from sympy.stats import P, Die + >>> from sympy import Eq + >>> X, Y = Die('X', 6), Die('Y', 6) + >>> P(X > 3) + 1/2 + >>> P(Eq(X, 5), X > 2) # Probability that X == 5 given that X > 2 + 1/4 + >>> P(X > Y) + 5/12 + """ + + kwargs['numsamples'] = numsamples + from sympy.stats.symbolic_probability import Probability + if evaluate: + return Probability(condition, given_condition).doit(**kwargs) + return Probability(condition, given_condition) + + +class Density(Basic): + expr = property(lambda self: self.args[0]) + + def __new__(cls, expr, condition = None): + expr = _sympify(expr) + if condition is None: + obj = Basic.__new__(cls, expr) + else: + condition = _sympify(condition) + obj = Basic.__new__(cls, expr, condition) + return obj + + @property + def condition(self): + if len(self.args) > 1: + return self.args[1] + else: + return None + + def doit(self, evaluate=True, **kwargs): + from sympy.stats.random_matrix import RandomMatrixPSpace + from sympy.stats.joint_rv import JointPSpace + from sympy.stats.matrix_distributions import MatrixPSpace + from sympy.stats.compound_rv import CompoundPSpace + from sympy.stats.frv import SingleFiniteDistribution + expr, condition = self.expr, self.condition + + if isinstance(expr, SingleFiniteDistribution): + return expr.dict + if condition is not None: + # Recompute on new conditional expr + expr = given(expr, condition, **kwargs) + if not random_symbols(expr): + return Lambda(x, DiracDelta(x - expr)) + if isinstance(expr, RandomSymbol): + if isinstance(expr.pspace, (SinglePSpace, JointPSpace, MatrixPSpace)) and \ + hasattr(expr.pspace, 'distribution'): + return expr.pspace.distribution + elif isinstance(expr.pspace, RandomMatrixPSpace): + return expr.pspace.model + if isinstance(pspace(expr), CompoundPSpace): + kwargs['compound_evaluate'] = evaluate + result = pspace(expr).compute_density(expr, **kwargs) + + if evaluate and hasattr(result, 'doit'): + return result.doit() + else: + return result + + +def density(expr, condition=None, evaluate=True, numsamples=None, **kwargs): + """ + Probability density of a random expression, optionally given a second + condition. + + Explanation + =========== + + This density will take on different forms for different types of + probability spaces. Discrete variables produce Dicts. Continuous + variables produce Lambdas. + + Parameters + ========== + + expr : Expr containing RandomSymbols + The expression of which you want to compute the density value + condition : Relational containing RandomSymbols + A conditional expression. density(X > 1, X > 0) is density of X > 1 + given X > 0 + numsamples : int + Enables sampling and approximates the density with this many samples + + Examples + ======== + + >>> from sympy.stats import density, Die, Normal + >>> from sympy import Symbol + + >>> x = Symbol('x') + >>> D = Die('D', 6) + >>> X = Normal(x, 0, 1) + + >>> density(D).dict + {1: 1/6, 2: 1/6, 3: 1/6, 4: 1/6, 5: 1/6, 6: 1/6} + >>> density(2*D).dict + {2: 1/6, 4: 1/6, 6: 1/6, 8: 1/6, 10: 1/6, 12: 1/6} + >>> density(X)(x) + sqrt(2)*exp(-x**2/2)/(2*sqrt(pi)) + """ + + if numsamples: + return sampling_density(expr, condition, numsamples=numsamples, + **kwargs) + + return Density(expr, condition).doit(evaluate=evaluate, **kwargs) + + +def cdf(expr, condition=None, evaluate=True, **kwargs): + """ + Cumulative Distribution Function of a random expression. + + optionally given a second condition. + + Explanation + =========== + + This density will take on different forms for different types of + probability spaces. + Discrete variables produce Dicts. + Continuous variables produce Lambdas. + + Examples + ======== + + >>> from sympy.stats import density, Die, Normal, cdf + + >>> D = Die('D', 6) + >>> X = Normal('X', 0, 1) + + >>> density(D).dict + {1: 1/6, 2: 1/6, 3: 1/6, 4: 1/6, 5: 1/6, 6: 1/6} + >>> cdf(D) + {1: 1/6, 2: 1/3, 3: 1/2, 4: 2/3, 5: 5/6, 6: 1} + >>> cdf(3*D, D > 2) + {9: 1/4, 12: 1/2, 15: 3/4, 18: 1} + + >>> cdf(X) + Lambda(_z, erf(sqrt(2)*_z/2)/2 + 1/2) + """ + if condition is not None: # If there is a condition + # Recompute on new conditional expr + return cdf(given(expr, condition, **kwargs), **kwargs) + + # Otherwise pass work off to the ProbabilitySpace + result = pspace(expr).compute_cdf(expr, **kwargs) + + if evaluate and hasattr(result, 'doit'): + return result.doit() + else: + return result + + +def characteristic_function(expr, condition=None, evaluate=True, **kwargs): + """ + Characteristic function of a random expression, optionally given a second condition. + + Returns a Lambda. + + Examples + ======== + + >>> from sympy.stats import Normal, DiscreteUniform, Poisson, characteristic_function + + >>> X = Normal('X', 0, 1) + >>> characteristic_function(X) + Lambda(_t, exp(-_t**2/2)) + + >>> Y = DiscreteUniform('Y', [1, 2, 7]) + >>> characteristic_function(Y) + Lambda(_t, exp(7*_t*I)/3 + exp(2*_t*I)/3 + exp(_t*I)/3) + + >>> Z = Poisson('Z', 2) + >>> characteristic_function(Z) + Lambda(_t, exp(2*exp(_t*I) - 2)) + """ + if condition is not None: + return characteristic_function(given(expr, condition, **kwargs), **kwargs) + + result = pspace(expr).compute_characteristic_function(expr, **kwargs) + + if evaluate and hasattr(result, 'doit'): + return result.doit() + else: + return result + +def moment_generating_function(expr, condition=None, evaluate=True, **kwargs): + if condition is not None: + return moment_generating_function(given(expr, condition, **kwargs), **kwargs) + + result = pspace(expr).compute_moment_generating_function(expr, **kwargs) + + if evaluate and hasattr(result, 'doit'): + return result.doit() + else: + return result + +def where(condition, given_condition=None, **kwargs): + """ + Returns the domain where a condition is True. + + Examples + ======== + + >>> from sympy.stats import where, Die, Normal + >>> from sympy import And + + >>> D1, D2 = Die('a', 6), Die('b', 6) + >>> a, b = D1.symbol, D2.symbol + >>> X = Normal('x', 0, 1) + + >>> where(X**2<1) + Domain: (-1 < x) & (x < 1) + + >>> where(X**2<1).set + Interval.open(-1, 1) + + >>> where(And(D1<=D2, D2<3)) + Domain: (Eq(a, 1) & Eq(b, 1)) | (Eq(a, 1) & Eq(b, 2)) | (Eq(a, 2) & Eq(b, 2)) + """ + if given_condition is not None: # If there is a condition + # Recompute on new conditional expr + return where(given(condition, given_condition, **kwargs), **kwargs) + + # Otherwise pass work off to the ProbabilitySpace + return pspace(condition).where(condition, **kwargs) + + +@doctest_depends_on(modules=('scipy',)) +def sample(expr, condition=None, size=(), library='scipy', + numsamples=1, seed=None, **kwargs): + """ + A realization of the random expression. + + Parameters + ========== + + expr : Expression of random variables + Expression from which sample is extracted + condition : Expr containing RandomSymbols + A conditional expression + size : int, tuple + Represents size of each sample in numsamples + library : str + - 'scipy' : Sample using scipy + - 'numpy' : Sample using numpy + - 'pymc' : Sample using PyMC + + Choose any of the available options to sample from as string, + by default is 'scipy' + numsamples : int + Number of samples, each with size as ``size``. + + .. deprecated:: 1.9 + + The ``numsamples`` parameter is deprecated and is only provided for + compatibility with v1.8. Use a list comprehension or an additional + dimension in ``size`` instead. See + :ref:`deprecated-sympy-stats-numsamples` for details. + + seed : + An object to be used as seed by the given external library for sampling `expr`. + Following is the list of possible types of object for the supported libraries, + + - 'scipy': int, numpy.random.RandomState, numpy.random.Generator + - 'numpy': int, numpy.random.RandomState, numpy.random.Generator + - 'pymc': int + + Optional, by default None, in which case seed settings + related to the given library will be used. + No modifications to environment's global seed settings + are done by this argument. + + Returns + ======= + + sample: float/list/numpy.ndarray + one sample or a collection of samples of the random expression. + + - sample(X) returns float/numpy.float64/numpy.int64 object. + - sample(X, size=int/tuple) returns numpy.ndarray object. + + Examples + ======== + + >>> from sympy.stats import Die, sample, Normal, Geometric + >>> X, Y, Z = Die('X', 6), Die('Y', 6), Die('Z', 6) # Finite Random Variable + >>> die_roll = sample(X + Y + Z) + >>> die_roll # doctest: +SKIP + 3 + >>> N = Normal('N', 3, 4) # Continuous Random Variable + >>> samp = sample(N) + >>> samp in N.pspace.domain.set + True + >>> samp = sample(N, N>0) + >>> samp > 0 + True + >>> samp_list = sample(N, size=4) + >>> [sam in N.pspace.domain.set for sam in samp_list] + [True, True, True, True] + >>> sample(N, size = (2,3)) # doctest: +SKIP + array([[5.42519758, 6.40207856, 4.94991743], + [1.85819627, 6.83403519, 1.9412172 ]]) + >>> G = Geometric('G', 0.5) # Discrete Random Variable + >>> samp_list = sample(G, size=3) + >>> samp_list # doctest: +SKIP + [1, 3, 2] + >>> [sam in G.pspace.domain.set for sam in samp_list] + [True, True, True] + >>> MN = Normal("MN", [3, 4], [[2, 1], [1, 2]]) # Joint Random Variable + >>> samp_list = sample(MN, size=4) + >>> samp_list # doctest: +SKIP + [array([2.85768055, 3.38954165]), + array([4.11163337, 4.3176591 ]), + array([0.79115232, 1.63232916]), + array([4.01747268, 3.96716083])] + >>> [tuple(sam) in MN.pspace.domain.set for sam in samp_list] + [True, True, True, True] + + .. versionchanged:: 1.7.0 + sample used to return an iterator containing the samples instead of value. + + .. versionchanged:: 1.9.0 + sample returns values or array of values instead of an iterator and numsamples is deprecated. + + """ + + iterator = sample_iter(expr, condition, size=size, library=library, + numsamples=numsamples, seed=seed) + + if numsamples != 1: + sympy_deprecation_warning( + f""" + The numsamples parameter to sympy.stats.sample() is deprecated. + Either use a list comprehension, like + + [sample(...) for i in range({numsamples})] + + or add a dimension to size, like + + sample(..., size={(numsamples,) + size}) + """, + deprecated_since_version="1.9", + active_deprecations_target="deprecated-sympy-stats-numsamples", + ) + return [next(iterator) for i in range(numsamples)] + + return next(iterator) + + +def quantile(expr, evaluate=True, **kwargs): + r""" + Return the :math:`p^{th}` order quantile of a probability distribution. + + Explanation + =========== + + Quantile is defined as the value at which the probability of the random + variable is less than or equal to the given probability. + + .. math:: + Q(p) = \inf\{x \in (-\infty, \infty) : p \le F(x)\} + + Examples + ======== + + >>> from sympy.stats import quantile, Die, Exponential + >>> from sympy import Symbol, pprint + >>> p = Symbol("p") + + >>> l = Symbol("lambda", positive=True) + >>> X = Exponential("x", l) + >>> quantile(X)(p) + -log(1 - p)/lambda + + >>> D = Die("d", 6) + >>> pprint(quantile(D)(p), use_unicode=False) + /nan for Or(p > 1, p < 0) + | + | 1 for p <= 1/6 + | + | 2 for p <= 1/3 + | + < 3 for p <= 1/2 + | + | 4 for p <= 2/3 + | + | 5 for p <= 5/6 + | + \ 6 for p <= 1 + + """ + result = pspace(expr).compute_quantile(expr, **kwargs) + + if evaluate and hasattr(result, 'doit'): + return result.doit() + else: + return result + +def sample_iter(expr, condition=None, size=(), library='scipy', + numsamples=S.Infinity, seed=None, **kwargs): + + """ + Returns an iterator of realizations from the expression given a condition. + + Parameters + ========== + + expr: Expr + Random expression to be realized + condition: Expr, optional + A conditional expression + size : int, tuple + Represents size of each sample in numsamples + numsamples: integer, optional + Length of the iterator (defaults to infinity) + seed : + An object to be used as seed by the given external library for sampling `expr`. + Following is the list of possible types of object for the supported libraries, + + - 'scipy': int, numpy.random.RandomState, numpy.random.Generator + - 'numpy': int, numpy.random.RandomState, numpy.random.Generator + - 'pymc': int + + Optional, by default None, in which case seed settings + related to the given library will be used. + No modifications to environment's global seed settings + are done by this argument. + + Examples + ======== + + >>> from sympy.stats import Normal, sample_iter + >>> X = Normal('X', 0, 1) + >>> expr = X*X + 3 + >>> iterator = sample_iter(expr, numsamples=3) # doctest: +SKIP + >>> list(iterator) # doctest: +SKIP + [12, 4, 7] + + Returns + ======= + + sample_iter: iterator object + iterator object containing the sample/samples of given expr + + See Also + ======== + + sample + sampling_P + sampling_E + + """ + from sympy.stats.joint_rv import JointRandomSymbol + if not import_module(library): + raise ValueError("Failed to import %s" % library) + + if condition is not None: + ps = pspace(Tuple(expr, condition)) + else: + ps = pspace(expr) + + rvs = list(ps.values) + if isinstance(expr, JointRandomSymbol): + expr = expr.subs({expr: RandomSymbol(expr.symbol, expr.pspace)}) + else: + sub = {} + for arg in expr.args: + if isinstance(arg, JointRandomSymbol): + sub[arg] = RandomSymbol(arg.symbol, arg.pspace) + expr = expr.subs(sub) + + def fn_subs(*args): + return expr.subs(dict(zip(rvs, args))) + + def given_fn_subs(*args): + if condition is not None: + return condition.subs(dict(zip(rvs, args))) + return False + + if library in ('pymc', 'pymc3'): + # Currently unable to lambdify in pymc + # TODO : Remove when lambdify accepts 'pymc' as module + fn = lambdify(rvs, expr, **kwargs) + else: + fn = lambdify(rvs, expr, modules=library, **kwargs) + + + if condition is not None: + given_fn = lambdify(rvs, condition, **kwargs) + + def return_generator_infinite(): + count = 0 + _size = (1,)+((size,) if isinstance(size, int) else size) + while count < numsamples: + d = ps.sample(size=_size, library=library, seed=seed) # a dictionary that maps RVs to values + args = [d[rv][0] for rv in rvs] + + if condition is not None: # Check that these values satisfy the condition + # TODO: Replace the try-except block with only given_fn(*args) + # once lambdify works with unevaluated SymPy objects. + try: + gd = given_fn(*args) + except (NameError, TypeError): + gd = given_fn_subs(*args) + if gd != True and gd != False: + raise ValueError( + "Conditions must not contain free symbols") + if not gd: # If the values don't satisfy then try again + continue + + yield fn(*args) + count += 1 + + def return_generator_finite(): + faulty = True + while faulty: + d = ps.sample(size=(numsamples,) + ((size,) if isinstance(size, int) else size), + library=library, seed=seed) # a dictionary that maps RVs to values + + faulty = False + count = 0 + while count < numsamples and not faulty: + args = [d[rv][count] for rv in rvs] + if condition is not None: # Check that these values satisfy the condition + # TODO: Replace the try-except block with only given_fn(*args) + # once lambdify works with unevaluated SymPy objects. + try: + gd = given_fn(*args) + except (NameError, TypeError): + gd = given_fn_subs(*args) + if gd != True and gd != False: + raise ValueError( + "Conditions must not contain free symbols") + if not gd: # If the values don't satisfy then try again + faulty = True + + count += 1 + + count = 0 + while count < numsamples: + args = [d[rv][count] for rv in rvs] + # TODO: Replace the try-except block with only fn(*args) + # once lambdify works with unevaluated SymPy objects. + try: + yield fn(*args) + except (NameError, TypeError): + yield fn_subs(*args) + count += 1 + + if numsamples is S.Infinity: + return return_generator_infinite() + + return return_generator_finite() + +def sample_iter_lambdify(expr, condition=None, size=(), + numsamples=S.Infinity, seed=None, **kwargs): + + return sample_iter(expr, condition=condition, size=size, + numsamples=numsamples, seed=seed, **kwargs) + +def sample_iter_subs(expr, condition=None, size=(), + numsamples=S.Infinity, seed=None, **kwargs): + + return sample_iter(expr, condition=condition, size=size, + numsamples=numsamples, seed=seed, **kwargs) + + +def sampling_P(condition, given_condition=None, library='scipy', numsamples=1, + evalf=True, seed=None, **kwargs): + """ + Sampling version of P. + + See Also + ======== + + P + sampling_E + sampling_density + + """ + + count_true = 0 + count_false = 0 + samples = sample_iter(condition, given_condition, library=library, + numsamples=numsamples, seed=seed, **kwargs) + + for sample in samples: + if sample: + count_true += 1 + else: + count_false += 1 + + result = S(count_true) / numsamples + if evalf: + return result.evalf() + else: + return result + + +def sampling_E(expr, given_condition=None, library='scipy', numsamples=1, + evalf=True, seed=None, **kwargs): + """ + Sampling version of E. + + See Also + ======== + + P + sampling_P + sampling_density + """ + samples = list(sample_iter(expr, given_condition, library=library, + numsamples=numsamples, seed=seed, **kwargs)) + result = Add(*samples) / numsamples + + if evalf: + return result.evalf() + else: + return result + +def sampling_density(expr, given_condition=None, library='scipy', + numsamples=1, seed=None, **kwargs): + """ + Sampling version of density. + + See Also + ======== + density + sampling_P + sampling_E + """ + + results = {} + for result in sample_iter(expr, given_condition, library=library, + numsamples=numsamples, seed=seed, **kwargs): + results[result] = results.get(result, 0) + 1 + + return results + + +def dependent(a, b): + """ + Dependence of two random expressions. + + Two expressions are independent if knowledge of one does not change + computations on the other. + + Examples + ======== + + >>> from sympy.stats import Normal, dependent, given + >>> from sympy import Tuple, Eq + + >>> X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + >>> dependent(X, Y) + False + >>> dependent(2*X + Y, -Y) + True + >>> X, Y = given(Tuple(X, Y), Eq(X + Y, 3)) + >>> dependent(X, Y) + True + + See Also + ======== + + independent + """ + if pspace_independent(a, b): + return False + + z = Symbol('z', real=True) + # Dependent if density is unchanged when one is given information about + # the other + return (density(a, Eq(b, z)) != density(a) or + density(b, Eq(a, z)) != density(b)) + + +def independent(a, b): + """ + Independence of two random expressions. + + Two expressions are independent if knowledge of one does not change + computations on the other. + + Examples + ======== + + >>> from sympy.stats import Normal, independent, given + >>> from sympy import Tuple, Eq + + >>> X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + >>> independent(X, Y) + True + >>> independent(2*X + Y, -Y) + False + >>> X, Y = given(Tuple(X, Y), Eq(X + Y, 3)) + >>> independent(X, Y) + False + + See Also + ======== + + dependent + """ + return not dependent(a, b) + + +def pspace_independent(a, b): + """ + Tests for independence between a and b by checking if their PSpaces have + overlapping symbols. This is a sufficient but not necessary condition for + independence and is intended to be used internally. + + Notes + ===== + + pspace_independent(a, b) implies independent(a, b) + independent(a, b) does not imply pspace_independent(a, b) + """ + a_symbols = set(pspace(b).symbols) + b_symbols = set(pspace(a).symbols) + + if len(set(random_symbols(a)).intersection(random_symbols(b))) != 0: + return False + + if len(a_symbols.intersection(b_symbols)) == 0: + return True + return None + + +def rv_subs(expr, symbols=None): + """ + Given a random expression replace all random variables with their symbols. + + If symbols keyword is given restrict the swap to only the symbols listed. + """ + if symbols is None: + symbols = random_symbols(expr) + if not symbols: + return expr + swapdict = {rv: rv.symbol for rv in symbols} + return expr.subs(swapdict) + + +class NamedArgsMixin: + _argnames: tuple[str, ...] = () + + def __getattr__(self, attr): + try: + return self.args[self._argnames.index(attr)] + except ValueError: + raise AttributeError("'%s' object has no attribute '%s'" % ( + type(self).__name__, attr)) + + +class Distribution(Basic): + + def sample(self, size=(), library='scipy', seed=None): + """ A random realization from the distribution """ + + module = import_module(library) + if library in {'scipy', 'numpy', 'pymc3', 'pymc'} and module is None: + raise ValueError("Failed to import %s" % library) + + if library == 'scipy': + # scipy does not require map as it can handle using custom distributions. + # However, we will still use a map where we can. + + # TODO: do this for drv.py and frv.py if necessary. + # TODO: add more distributions here if there are more + # See links below referring to sections beginning with "A common parametrization..." + # I will remove all these comments if everything is ok. + + from sympy.stats.sampling.sample_scipy import do_sample_scipy + import numpy + if seed is None or isinstance(seed, int): + rand_state = numpy.random.default_rng(seed=seed) + else: + rand_state = seed + samps = do_sample_scipy(self, size, rand_state) + + elif library == 'numpy': + from sympy.stats.sampling.sample_numpy import do_sample_numpy + import numpy + if seed is None or isinstance(seed, int): + rand_state = numpy.random.default_rng(seed=seed) + else: + rand_state = seed + _size = None if size == () else size + samps = do_sample_numpy(self, _size, rand_state) + elif library in ('pymc', 'pymc3'): + from sympy.stats.sampling.sample_pymc import do_sample_pymc + import logging + logging.getLogger("pymc").setLevel(logging.ERROR) + try: + import pymc + except ImportError: + import pymc3 as pymc + + with pymc.Model(): + if do_sample_pymc(self) is not None: + samps = pymc.sample(draws=prod(size), chains=1, compute_convergence_checks=False, + progressbar=False, random_seed=seed, return_inferencedata=False)[:]['X'] + samps = samps.reshape(size) + else: + samps = None + + else: + raise NotImplementedError("Sampling from %s is not supported yet." + % str(library)) + + if samps is not None: + return samps + raise NotImplementedError( + "Sampling for %s is not currently implemented from %s" + % (self, library)) + + +def _value_check(condition, message): + """ + Raise a ValueError with message if condition is False, else + return True if all conditions were True, else False. + + Examples + ======== + + >>> from sympy.stats.rv import _value_check + >>> from sympy.abc import a, b, c + >>> from sympy import And, Dummy + + >>> _value_check(2 < 3, '') + True + + Here, the condition is not False, but it does not evaluate to True + so False is returned (but no error is raised). So checking if the + return value is True or False will tell you if all conditions were + evaluated. + + >>> _value_check(a < b, '') + False + + In this case the condition is False so an error is raised: + + >>> r = Dummy(real=True) + >>> _value_check(r < r - 1, 'condition is not true') + Traceback (most recent call last): + ... + ValueError: condition is not true + + If no condition of many conditions must be False, they can be + checked by passing them as an iterable: + + >>> _value_check((a < 0, b < 0, c < 0), '') + False + + The iterable can be a generator, too: + + >>> _value_check((i < 0 for i in (a, b, c)), '') + False + + The following are equivalent to the above but do not pass + an iterable: + + >>> all(_value_check(i < 0, '') for i in (a, b, c)) + False + >>> _value_check(And(a < 0, b < 0, c < 0), '') + False + """ + if not iterable(condition): + condition = [condition] + truth = fuzzy_and(condition) + if truth == False: + raise ValueError(message) + return truth == True + +def _symbol_converter(sym): + """ + Casts the parameter to Symbol if it is 'str' + otherwise no operation is performed on it. + + Parameters + ========== + + sym + The parameter to be converted. + + Returns + ======= + + Symbol + the parameter converted to Symbol. + + Raises + ====== + + TypeError + If the parameter is not an instance of both str and + Symbol. + + Examples + ======== + + >>> from sympy import Symbol + >>> from sympy.stats.rv import _symbol_converter + >>> s = _symbol_converter('s') + >>> isinstance(s, Symbol) + True + >>> _symbol_converter(1) + Traceback (most recent call last): + ... + TypeError: 1 is neither a Symbol nor a string + >>> r = Symbol('r') + >>> isinstance(r, Symbol) + True + """ + if isinstance(sym, str): + sym = Symbol(sym) + if not isinstance(sym, Symbol): + raise TypeError("%s is neither a Symbol nor a string"%(sym)) + return sym + +def sample_stochastic_process(process): + """ + This function is used to sample from stochastic process. + + Parameters + ========== + + process: StochasticProcess + Process used to extract the samples. It must be an instance of + StochasticProcess + + Examples + ======== + + >>> from sympy.stats import sample_stochastic_process, DiscreteMarkovChain + >>> from sympy import Matrix + >>> T = Matrix([[0.5, 0.2, 0.3],[0.2, 0.5, 0.3],[0.2, 0.3, 0.5]]) + >>> Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + >>> next(sample_stochastic_process(Y)) in Y.state_space + True + >>> next(sample_stochastic_process(Y)) # doctest: +SKIP + 0 + >>> next(sample_stochastic_process(Y)) # doctest: +SKIP + 2 + + Returns + ======= + + sample: iterator object + iterator object containing the sample of given process + + """ + from sympy.stats.stochastic_process_types import StochasticProcess + if not isinstance(process, StochasticProcess): + raise ValueError("Process must be an instance of Stochastic Process") + return process.sample() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/rv_interface.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/rv_interface.py new file mode 100644 index 0000000000000000000000000000000000000000..16d65b83634cdb04ef7e5046175848cdf380434b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/rv_interface.py @@ -0,0 +1,519 @@ +from sympy.sets import FiniteSet +from sympy.core.numbers import Rational +from sympy.core.relational import Eq +from sympy.core.symbol import Dummy +from sympy.functions.combinatorial.factorials import FallingFactorial +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import piecewise_fold +from sympy.integrals.integrals import Integral +from sympy.solvers.solveset import solveset +from .rv import (probability, expectation, density, where, given, pspace, cdf, PSpace, + characteristic_function, sample, sample_iter, random_symbols, independent, dependent, + sampling_density, moment_generating_function, quantile, is_random, + sample_stochastic_process) + + +__all__ = ['P', 'E', 'H', 'density', 'where', 'given', 'sample', 'cdf', + 'characteristic_function', 'pspace', 'sample_iter', 'variance', 'std', + 'skewness', 'kurtosis', 'covariance', 'dependent', 'entropy', 'median', + 'independent', 'random_symbols', 'correlation', 'factorial_moment', + 'moment', 'cmoment', 'sampling_density', 'moment_generating_function', + 'smoment', 'quantile', 'sample_stochastic_process'] + + + +def moment(X, n, c=0, condition=None, *, evaluate=True, **kwargs): + """ + Return the nth moment of a random expression about c. + + .. math:: + moment(X, c, n) = E((X-c)^{n}) + + Default value of c is 0. + + Examples + ======== + + >>> from sympy.stats import Die, moment, E + >>> X = Die('X', 6) + >>> moment(X, 1, 6) + -5/2 + >>> moment(X, 2) + 91/6 + >>> moment(X, 1) == E(X) + True + """ + from sympy.stats.symbolic_probability import Moment + if evaluate: + return Moment(X, n, c, condition).doit() + return Moment(X, n, c, condition).rewrite(Integral) + + +def variance(X, condition=None, **kwargs): + """ + Variance of a random expression. + + .. math:: + variance(X) = E((X-E(X))^{2}) + + Examples + ======== + + >>> from sympy.stats import Die, Bernoulli, variance + >>> from sympy import simplify, Symbol + + >>> X = Die('X', 6) + >>> p = Symbol('p') + >>> B = Bernoulli('B', p, 1, 0) + + >>> variance(2*X) + 35/3 + + >>> simplify(variance(B)) + p*(1 - p) + """ + if is_random(X) and pspace(X) == PSpace(): + from sympy.stats.symbolic_probability import Variance + return Variance(X, condition) + + return cmoment(X, 2, condition, **kwargs) + + +def standard_deviation(X, condition=None, **kwargs): + r""" + Standard Deviation of a random expression + + .. math:: + std(X) = \sqrt(E((X-E(X))^{2})) + + Examples + ======== + + >>> from sympy.stats import Bernoulli, std + >>> from sympy import Symbol, simplify + + >>> p = Symbol('p') + >>> B = Bernoulli('B', p, 1, 0) + + >>> simplify(std(B)) + sqrt(p*(1 - p)) + """ + return sqrt(variance(X, condition, **kwargs)) +std = standard_deviation + +def entropy(expr, condition=None, **kwargs): + """ + Calculates entropy of a probability distribution. + + Parameters + ========== + + expression : the random expression whose entropy is to be calculated + condition : optional, to specify conditions on random expression + b: base of the logarithm, optional + By default, it is taken as Euler's number + + Returns + ======= + + result : Entropy of the expression, a constant + + Examples + ======== + + >>> from sympy.stats import Normal, Die, entropy + >>> X = Normal('X', 0, 1) + >>> entropy(X) + log(2)/2 + 1/2 + log(pi)/2 + + >>> D = Die('D', 4) + >>> entropy(D) + log(4) + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Entropy_%28information_theory%29 + .. [2] https://www.crmarsh.com/static/pdf/Charles_Marsh_Continuous_Entropy.pdf + .. [3] https://kconrad.math.uconn.edu/blurbs/analysis/entropypost.pdf + """ + pdf = density(expr, condition, **kwargs) + base = kwargs.get('b', exp(1)) + if isinstance(pdf, dict): + return sum(-prob*log(prob, base) for prob in pdf.values()) + return expectation(-log(pdf(expr), base)) + +def covariance(X, Y, condition=None, **kwargs): + """ + Covariance of two random expressions. + + Explanation + =========== + + The expectation that the two variables will rise and fall together + + .. math:: + covariance(X,Y) = E((X-E(X)) (Y-E(Y))) + + Examples + ======== + + >>> from sympy.stats import Exponential, covariance + >>> from sympy import Symbol + + >>> rate = Symbol('lambda', positive=True, real=True) + >>> X = Exponential('X', rate) + >>> Y = Exponential('Y', rate) + + >>> covariance(X, X) + lambda**(-2) + >>> covariance(X, Y) + 0 + >>> covariance(X, Y + rate*X) + 1/lambda + """ + if (is_random(X) and pspace(X) == PSpace()) or (is_random(Y) and pspace(Y) == PSpace()): + from sympy.stats.symbolic_probability import Covariance + return Covariance(X, Y, condition) + + return expectation( + (X - expectation(X, condition, **kwargs)) * + (Y - expectation(Y, condition, **kwargs)), + condition, **kwargs) + + +def correlation(X, Y, condition=None, **kwargs): + r""" + Correlation of two random expressions, also known as correlation + coefficient or Pearson's correlation. + + Explanation + =========== + + The normalized expectation that the two variables will rise + and fall together + + .. math:: + correlation(X,Y) = E((X-E(X))(Y-E(Y)) / (\sigma_x \sigma_y)) + + Examples + ======== + + >>> from sympy.stats import Exponential, correlation + >>> from sympy import Symbol + + >>> rate = Symbol('lambda', positive=True, real=True) + >>> X = Exponential('X', rate) + >>> Y = Exponential('Y', rate) + + >>> correlation(X, X) + 1 + >>> correlation(X, Y) + 0 + >>> correlation(X, Y + rate*X) + 1/sqrt(1 + lambda**(-2)) + """ + return covariance(X, Y, condition, **kwargs)/(std(X, condition, **kwargs) + * std(Y, condition, **kwargs)) + + +def cmoment(X, n, condition=None, *, evaluate=True, **kwargs): + """ + Return the nth central moment of a random expression about its mean. + + .. math:: + cmoment(X, n) = E((X - E(X))^{n}) + + Examples + ======== + + >>> from sympy.stats import Die, cmoment, variance + >>> X = Die('X', 6) + >>> cmoment(X, 3) + 0 + >>> cmoment(X, 2) + 35/12 + >>> cmoment(X, 2) == variance(X) + True + """ + from sympy.stats.symbolic_probability import CentralMoment + if evaluate: + return CentralMoment(X, n, condition).doit() + return CentralMoment(X, n, condition).rewrite(Integral) + + +def smoment(X, n, condition=None, **kwargs): + r""" + Return the nth Standardized moment of a random expression. + + .. math:: + smoment(X, n) = E(((X - \mu)/\sigma_X)^{n}) + + Examples + ======== + + >>> from sympy.stats import skewness, Exponential, smoment + >>> from sympy import Symbol + >>> rate = Symbol('lambda', positive=True, real=True) + >>> Y = Exponential('Y', rate) + >>> smoment(Y, 4) + 9 + >>> smoment(Y, 4) == smoment(3*Y, 4) + True + >>> smoment(Y, 3) == skewness(Y) + True + """ + sigma = std(X, condition, **kwargs) + return (1/sigma)**n*cmoment(X, n, condition, **kwargs) + +def skewness(X, condition=None, **kwargs): + r""" + Measure of the asymmetry of the probability distribution. + + Explanation + =========== + + Positive skew indicates that most of the values lie to the right of + the mean. + + .. math:: + skewness(X) = E(((X - E(X))/\sigma_X)^{3}) + + Parameters + ========== + + condition : Expr containing RandomSymbols + A conditional expression. skewness(X, X>0) is skewness of X given X > 0 + + Examples + ======== + + >>> from sympy.stats import skewness, Exponential, Normal + >>> from sympy import Symbol + >>> X = Normal('X', 0, 1) + >>> skewness(X) + 0 + >>> skewness(X, X > 0) # find skewness given X > 0 + (-sqrt(2)/sqrt(pi) + 4*sqrt(2)/pi**(3/2))/(1 - 2/pi)**(3/2) + + >>> rate = Symbol('lambda', positive=True, real=True) + >>> Y = Exponential('Y', rate) + >>> skewness(Y) + 2 + """ + return smoment(X, 3, condition=condition, **kwargs) + +def kurtosis(X, condition=None, **kwargs): + r""" + Characterizes the tails/outliers of a probability distribution. + + Explanation + =========== + + Kurtosis of any univariate normal distribution is 3. Kurtosis less than + 3 means that the distribution produces fewer and less extreme outliers + than the normal distribution. + + .. math:: + kurtosis(X) = E(((X - E(X))/\sigma_X)^{4}) + + Parameters + ========== + + condition : Expr containing RandomSymbols + A conditional expression. kurtosis(X, X>0) is kurtosis of X given X > 0 + + Examples + ======== + + >>> from sympy.stats import kurtosis, Exponential, Normal + >>> from sympy import Symbol + >>> X = Normal('X', 0, 1) + >>> kurtosis(X) + 3 + >>> kurtosis(X, X > 0) # find kurtosis given X > 0 + (-4/pi - 12/pi**2 + 3)/(1 - 2/pi)**2 + + >>> rate = Symbol('lamda', positive=True, real=True) + >>> Y = Exponential('Y', rate) + >>> kurtosis(Y) + 9 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Kurtosis + .. [2] https://mathworld.wolfram.com/Kurtosis.html + """ + return smoment(X, 4, condition=condition, **kwargs) + + +def factorial_moment(X, n, condition=None, **kwargs): + """ + The factorial moment is a mathematical quantity defined as the expectation + or average of the falling factorial of a random variable. + + .. math:: + factorial-moment(X, n) = E(X(X - 1)(X - 2)...(X - n + 1)) + + Parameters + ========== + + n: A natural number, n-th factorial moment. + + condition : Expr containing RandomSymbols + A conditional expression. + + Examples + ======== + + >>> from sympy.stats import factorial_moment, Poisson, Binomial + >>> from sympy import Symbol, S + >>> lamda = Symbol('lamda') + >>> X = Poisson('X', lamda) + >>> factorial_moment(X, 2) + lamda**2 + >>> Y = Binomial('Y', 2, S.Half) + >>> factorial_moment(Y, 2) + 1/2 + >>> factorial_moment(Y, 2, Y > 1) # find factorial moment for Y > 1 + 2 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Factorial_moment + .. [2] https://mathworld.wolfram.com/FactorialMoment.html + """ + return expectation(FallingFactorial(X, n), condition=condition, **kwargs) + +def median(X, evaluate=True, **kwargs): + r""" + Calculates the median of the probability distribution. + + Explanation + =========== + + Mathematically, median of Probability distribution is defined as all those + values of `m` for which the following condition is satisfied + + .. math:: + P(X\leq m) \geq \frac{1}{2} \text{ and} \text{ } P(X\geq m)\geq \frac{1}{2} + + Parameters + ========== + + X: The random expression whose median is to be calculated. + + Returns + ======= + + The FiniteSet or an Interval which contains the median of the + random expression. + + Examples + ======== + + >>> from sympy.stats import Normal, Die, median + >>> N = Normal('N', 3, 1) + >>> median(N) + {3} + >>> D = Die('D') + >>> median(D) + {3, 4} + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Median#Probability_distributions + + """ + if not is_random(X): + return X + + from sympy.stats.crv import ContinuousPSpace + from sympy.stats.drv import DiscretePSpace + from sympy.stats.frv import FinitePSpace + + if isinstance(pspace(X), FinitePSpace): + cdf = pspace(X).compute_cdf(X) + result = [] + for key, value in cdf.items(): + if value>= Rational(1, 2) and (1 - value) + \ + pspace(X).probability(Eq(X, key)) >= Rational(1, 2): + result.append(key) + return FiniteSet(*result) + if isinstance(pspace(X), (ContinuousPSpace, DiscretePSpace)): + cdf = pspace(X).compute_cdf(X) + x = Dummy('x') + result = solveset(piecewise_fold(cdf(x) - Rational(1, 2)), x, pspace(X).set) + return result + raise NotImplementedError("The median of %s is not implemented."%str(pspace(X))) + + +def coskewness(X, Y, Z, condition=None, **kwargs): + r""" + Calculates the co-skewness of three random variables. + + Explanation + =========== + + Mathematically Coskewness is defined as + + .. math:: + coskewness(X,Y,Z)=\frac{E[(X-E[X]) * (Y-E[Y]) * (Z-E[Z])]} {\sigma_{X}\sigma_{Y}\sigma_{Z}} + + Parameters + ========== + + X : RandomSymbol + Random Variable used to calculate coskewness + Y : RandomSymbol + Random Variable used to calculate coskewness + Z : RandomSymbol + Random Variable used to calculate coskewness + condition : Expr containing RandomSymbols + A conditional expression + + Examples + ======== + + >>> from sympy.stats import coskewness, Exponential, skewness + >>> from sympy import symbols + >>> p = symbols('p', positive=True) + >>> X = Exponential('X', p) + >>> Y = Exponential('Y', 2*p) + >>> coskewness(X, Y, Y) + 0 + >>> coskewness(X, Y + X, Y + 2*X) + 16*sqrt(85)/85 + >>> coskewness(X + 2*Y, Y + X, Y + 2*X, X > 3) + 9*sqrt(170)/85 + >>> coskewness(Y, Y, Y) == skewness(Y) + True + >>> coskewness(X, Y + p*X, Y + 2*p*X) + 4/(sqrt(1 + 1/(4*p**2))*sqrt(4 + 1/(4*p**2))) + + Returns + ======= + + coskewness : The coskewness of the three random variables + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Coskewness + + """ + num = expectation((X - expectation(X, condition, **kwargs)) \ + * (Y - expectation(Y, condition, **kwargs)) \ + * (Z - expectation(Z, condition, **kwargs)), condition, **kwargs) + den = std(X, condition, **kwargs) * std(Y, condition, **kwargs) \ + * std(Z, condition, **kwargs) + return num/den + + +P = probability +E = expectation +H = entropy diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_numpy.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_numpy.py new file mode 100644 index 0000000000000000000000000000000000000000..d65417945449ed8b62d2547215d8908f84820a9b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_numpy.py @@ -0,0 +1,105 @@ +from functools import singledispatch + +from sympy.external import import_module +from sympy.stats.crv_types import BetaDistribution, ChiSquaredDistribution, ExponentialDistribution, GammaDistribution, \ + LogNormalDistribution, NormalDistribution, ParetoDistribution, UniformDistribution, FDistributionDistribution, GumbelDistribution, LaplaceDistribution, \ + LogisticDistribution, RayleighDistribution, TriangularDistribution +from sympy.stats.drv_types import GeometricDistribution, PoissonDistribution, ZetaDistribution +from sympy.stats.frv_types import BinomialDistribution, HypergeometricDistribution + + +numpy = import_module('numpy') + + +@singledispatch +def do_sample_numpy(dist, size, rand_state): + return None + + +# CRV: + +@do_sample_numpy.register(BetaDistribution) +def _(dist: BetaDistribution, size, rand_state): + return rand_state.beta(a=float(dist.alpha), b=float(dist.beta), size=size) + + +@do_sample_numpy.register(ChiSquaredDistribution) +def _(dist: ChiSquaredDistribution, size, rand_state): + return rand_state.chisquare(df=float(dist.k), size=size) + + +@do_sample_numpy.register(ExponentialDistribution) +def _(dist: ExponentialDistribution, size, rand_state): + return rand_state.exponential(1 / float(dist.rate), size=size) + +@do_sample_numpy.register(FDistributionDistribution) +def _(dist: FDistributionDistribution, size, rand_state): + return rand_state.f(dfnum = float(dist.d1), dfden = float(dist.d2), size=size) + +@do_sample_numpy.register(GammaDistribution) +def _(dist: GammaDistribution, size, rand_state): + return rand_state.gamma(shape = float(dist.k), scale = float(dist.theta), size=size) + +@do_sample_numpy.register(GumbelDistribution) +def _(dist: GumbelDistribution, size, rand_state): + return rand_state.gumbel(loc = float(dist.mu), scale = float(dist.beta), size=size) + +@do_sample_numpy.register(LaplaceDistribution) +def _(dist: LaplaceDistribution, size, rand_state): + return rand_state.laplace(loc = float(dist.mu), scale = float(dist.b), size=size) + +@do_sample_numpy.register(LogisticDistribution) +def _(dist: LogisticDistribution, size, rand_state): + return rand_state.logistic(loc = float(dist.mu), scale = float(dist.s), size=size) + +@do_sample_numpy.register(LogNormalDistribution) +def _(dist: LogNormalDistribution, size, rand_state): + return rand_state.lognormal(mean = float(dist.mean), sigma = float(dist.std), size=size) + +@do_sample_numpy.register(NormalDistribution) +def _(dist: NormalDistribution, size, rand_state): + return rand_state.normal(loc = float(dist.mean), scale = float(dist.std), size=size) + +@do_sample_numpy.register(RayleighDistribution) +def _(dist: RayleighDistribution, size, rand_state): + return rand_state.rayleigh(scale = float(dist.sigma), size=size) + +@do_sample_numpy.register(ParetoDistribution) +def _(dist: ParetoDistribution, size, rand_state): + return (numpy.random.pareto(a=float(dist.alpha), size=size) + 1) * float(dist.xm) + +@do_sample_numpy.register(TriangularDistribution) +def _(dist: TriangularDistribution, size, rand_state): + return rand_state.triangular(left = float(dist.a), mode = float(dist.b), right = float(dist.c), size=size) + +@do_sample_numpy.register(UniformDistribution) +def _(dist: UniformDistribution, size, rand_state): + return rand_state.uniform(low=float(dist.left), high=float(dist.right), size=size) + + +# DRV: + +@do_sample_numpy.register(GeometricDistribution) +def _(dist: GeometricDistribution, size, rand_state): + return rand_state.geometric(p=float(dist.p), size=size) + + +@do_sample_numpy.register(PoissonDistribution) +def _(dist: PoissonDistribution, size, rand_state): + return rand_state.poisson(lam=float(dist.lamda), size=size) + + +@do_sample_numpy.register(ZetaDistribution) +def _(dist: ZetaDistribution, size, rand_state): + return rand_state.zipf(a=float(dist.s), size=size) + + +# FRV: + +@do_sample_numpy.register(BinomialDistribution) +def _(dist: BinomialDistribution, size, rand_state): + return rand_state.binomial(n=int(dist.n), p=float(dist.p), size=size) + +@do_sample_numpy.register(HypergeometricDistribution) +def _(dist: HypergeometricDistribution, size, rand_state): + return rand_state.hypergeometric(ngood = int(dist.N), nbad = int(dist.m), nsample = int(dist.n), size=size) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_pymc.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_pymc.py new file mode 100644 index 0000000000000000000000000000000000000000..546f02a3092815af2e54b4a164463f62ece7a024 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_pymc.py @@ -0,0 +1,99 @@ +from functools import singledispatch +from sympy.external import import_module +from sympy.stats.crv_types import BetaDistribution, CauchyDistribution, ChiSquaredDistribution, ExponentialDistribution, \ + GammaDistribution, LogNormalDistribution, NormalDistribution, ParetoDistribution, UniformDistribution, \ + GaussianInverseDistribution +from sympy.stats.drv_types import PoissonDistribution, GeometricDistribution, NegativeBinomialDistribution +from sympy.stats.frv_types import BinomialDistribution, BernoulliDistribution + + +try: + import pymc +except ImportError: + pymc = import_module('pymc3') + +@singledispatch +def do_sample_pymc(dist): + return None + + +# CRV: + +@do_sample_pymc.register(BetaDistribution) +def _(dist: BetaDistribution): + return pymc.Beta('X', alpha=float(dist.alpha), beta=float(dist.beta)) + + +@do_sample_pymc.register(CauchyDistribution) +def _(dist: CauchyDistribution): + return pymc.Cauchy('X', alpha=float(dist.x0), beta=float(dist.gamma)) + + +@do_sample_pymc.register(ChiSquaredDistribution) +def _(dist: ChiSquaredDistribution): + return pymc.ChiSquared('X', nu=float(dist.k)) + + +@do_sample_pymc.register(ExponentialDistribution) +def _(dist: ExponentialDistribution): + return pymc.Exponential('X', lam=float(dist.rate)) + + +@do_sample_pymc.register(GammaDistribution) +def _(dist: GammaDistribution): + return pymc.Gamma('X', alpha=float(dist.k), beta=1 / float(dist.theta)) + + +@do_sample_pymc.register(LogNormalDistribution) +def _(dist: LogNormalDistribution): + return pymc.Lognormal('X', mu=float(dist.mean), sigma=float(dist.std)) + + +@do_sample_pymc.register(NormalDistribution) +def _(dist: NormalDistribution): + return pymc.Normal('X', float(dist.mean), float(dist.std)) + + +@do_sample_pymc.register(GaussianInverseDistribution) +def _(dist: GaussianInverseDistribution): + return pymc.Wald('X', mu=float(dist.mean), lam=float(dist.shape)) + + +@do_sample_pymc.register(ParetoDistribution) +def _(dist: ParetoDistribution): + return pymc.Pareto('X', alpha=float(dist.alpha), m=float(dist.xm)) + + +@do_sample_pymc.register(UniformDistribution) +def _(dist: UniformDistribution): + return pymc.Uniform('X', lower=float(dist.left), upper=float(dist.right)) + + +# DRV: + +@do_sample_pymc.register(GeometricDistribution) +def _(dist: GeometricDistribution): + return pymc.Geometric('X', p=float(dist.p)) + + +@do_sample_pymc.register(NegativeBinomialDistribution) +def _(dist: NegativeBinomialDistribution): + return pymc.NegativeBinomial('X', mu=float((dist.p * dist.r) / (1 - dist.p)), + alpha=float(dist.r)) + + +@do_sample_pymc.register(PoissonDistribution) +def _(dist: PoissonDistribution): + return pymc.Poisson('X', mu=float(dist.lamda)) + + +# FRV: + +@do_sample_pymc.register(BernoulliDistribution) +def _(dist: BernoulliDistribution): + return pymc.Bernoulli('X', p=float(dist.p)) + + +@do_sample_pymc.register(BinomialDistribution) +def _(dist: BinomialDistribution): + return pymc.Binomial('X', n=int(dist.n), p=float(dist.p)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_scipy.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_scipy.py new file mode 100644 index 0000000000000000000000000000000000000000..f12508f68844488e9a14b1476005164eb422796e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/sample_scipy.py @@ -0,0 +1,167 @@ +from functools import singledispatch + +from sympy.core.symbol import Dummy +from sympy.functions.elementary.exponential import exp +from sympy.utilities.lambdify import lambdify +from sympy.external import import_module +from sympy.stats import DiscreteDistributionHandmade +from sympy.stats.crv import SingleContinuousDistribution +from sympy.stats.crv_types import ChiSquaredDistribution, ExponentialDistribution, GammaDistribution, \ + LogNormalDistribution, NormalDistribution, ParetoDistribution, UniformDistribution, BetaDistribution, \ + StudentTDistribution, CauchyDistribution +from sympy.stats.drv_types import GeometricDistribution, LogarithmicDistribution, NegativeBinomialDistribution, \ + PoissonDistribution, SkellamDistribution, YuleSimonDistribution, ZetaDistribution +from sympy.stats.frv import SingleFiniteDistribution + + +scipy = import_module("scipy", import_kwargs={'fromlist':['stats']}) + + +@singledispatch +def do_sample_scipy(dist, size, seed): + return None + + +# CRV + +@do_sample_scipy.register(SingleContinuousDistribution) +def _(dist: SingleContinuousDistribution, size, seed): + # if we don't need to make a handmade pdf, we won't + import scipy.stats + + z = Dummy('z') + handmade_pdf = lambdify(z, dist.pdf(z), ['numpy', 'scipy']) + + class scipy_pdf(scipy.stats.rv_continuous): + def _pdf(dist, x): + return handmade_pdf(x) + + scipy_rv = scipy_pdf(a=float(dist.set._inf), + b=float(dist.set._sup), name='scipy_pdf') + return scipy_rv.rvs(size=size, random_state=seed) + + +@do_sample_scipy.register(ChiSquaredDistribution) +def _(dist: ChiSquaredDistribution, size, seed): + # same parametrisation + return scipy.stats.chi2.rvs(df=float(dist.k), size=size, random_state=seed) + + +@do_sample_scipy.register(ExponentialDistribution) +def _(dist: ExponentialDistribution, size, seed): + # https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.expon.html#scipy.stats.expon + return scipy.stats.expon.rvs(scale=1 / float(dist.rate), size=size, random_state=seed) + + +@do_sample_scipy.register(GammaDistribution) +def _(dist: GammaDistribution, size, seed): + # https://stackoverflow.com/questions/42150965/how-to-plot-gamma-distribution-with-alpha-and-beta-parameters-in-python + return scipy.stats.gamma.rvs(a=float(dist.k), scale=float(dist.theta), size=size, random_state=seed) + + +@do_sample_scipy.register(LogNormalDistribution) +def _(dist: LogNormalDistribution, size, seed): + # https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.lognorm.html + return scipy.stats.lognorm.rvs(scale=float(exp(dist.mean)), s=float(dist.std), size=size, random_state=seed) + + +@do_sample_scipy.register(NormalDistribution) +def _(dist: NormalDistribution, size, seed): + return scipy.stats.norm.rvs(loc=float(dist.mean), scale=float(dist.std), size=size, random_state=seed) + + +@do_sample_scipy.register(ParetoDistribution) +def _(dist: ParetoDistribution, size, seed): + # https://stackoverflow.com/questions/42260519/defining-pareto-distribution-in-python-scipy + return scipy.stats.pareto.rvs(b=float(dist.alpha), scale=float(dist.xm), size=size, random_state=seed) + + +@do_sample_scipy.register(StudentTDistribution) +def _(dist: StudentTDistribution, size, seed): + return scipy.stats.t.rvs(df=float(dist.nu), size=size, random_state=seed) + + +@do_sample_scipy.register(UniformDistribution) +def _(dist: UniformDistribution, size, seed): + # https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.uniform.html + return scipy.stats.uniform.rvs(loc=float(dist.left), scale=float(dist.right - dist.left), size=size, random_state=seed) + + +@do_sample_scipy.register(BetaDistribution) +def _(dist: BetaDistribution, size, seed): + # same parametrisation + return scipy.stats.beta.rvs(a=float(dist.alpha), b=float(dist.beta), size=size, random_state=seed) + + +@do_sample_scipy.register(CauchyDistribution) +def _(dist: CauchyDistribution, size, seed): + return scipy.stats.cauchy.rvs(loc=float(dist.x0), scale=float(dist.gamma), size=size, random_state=seed) + + +# DRV: + +@do_sample_scipy.register(DiscreteDistributionHandmade) +def _(dist: DiscreteDistributionHandmade, size, seed): + from scipy.stats import rv_discrete + + z = Dummy('z') + handmade_pmf = lambdify(z, dist.pdf(z), ['numpy', 'scipy']) + + class scipy_pmf(rv_discrete): + def _pmf(dist, x): + return handmade_pmf(x) + + scipy_rv = scipy_pmf(a=float(dist.set._inf), b=float(dist.set._sup), + name='scipy_pmf') + return scipy_rv.rvs(size=size, random_state=seed) + + +@do_sample_scipy.register(GeometricDistribution) +def _(dist: GeometricDistribution, size, seed): + return scipy.stats.geom.rvs(p=float(dist.p), size=size, random_state=seed) + + +@do_sample_scipy.register(LogarithmicDistribution) +def _(dist: LogarithmicDistribution, size, seed): + return scipy.stats.logser.rvs(p=float(dist.p), size=size, random_state=seed) + + +@do_sample_scipy.register(NegativeBinomialDistribution) +def _(dist: NegativeBinomialDistribution, size, seed): + return scipy.stats.nbinom.rvs(n=float(dist.r), p=float(dist.p), size=size, random_state=seed) + + +@do_sample_scipy.register(PoissonDistribution) +def _(dist: PoissonDistribution, size, seed): + return scipy.stats.poisson.rvs(mu=float(dist.lamda), size=size, random_state=seed) + + +@do_sample_scipy.register(SkellamDistribution) +def _(dist: SkellamDistribution, size, seed): + return scipy.stats.skellam.rvs(mu1=float(dist.mu1), mu2=float(dist.mu2), size=size, random_state=seed) + + +@do_sample_scipy.register(YuleSimonDistribution) +def _(dist: YuleSimonDistribution, size, seed): + return scipy.stats.yulesimon.rvs(alpha=float(dist.rho), size=size, random_state=seed) + + +@do_sample_scipy.register(ZetaDistribution) +def _(dist: ZetaDistribution, size, seed): + return scipy.stats.zipf.rvs(a=float(dist.s), size=size, random_state=seed) + + +# FRV: + +@do_sample_scipy.register(SingleFiniteDistribution) +def _(dist: SingleFiniteDistribution, size, seed): + # scipy can handle with custom distributions + + from scipy.stats import rv_discrete + density_ = dist.dict + x, y = [], [] + for k, v in density_.items(): + x.append(int(k)) + y.append(float(v)) + scipy_rv = rv_discrete(name='scipy_rv', values=(x, y)) + return scipy_rv.rvs(size=size, random_state=seed) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_continuous_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_continuous_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..953bb602df5e63da2882ee118de9dbf24b6f7804 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_continuous_rv.py @@ -0,0 +1,181 @@ +from sympy.core.numbers import oo +from sympy.core.symbol import Symbol +from sympy.functions.elementary.exponential import exp +from sympy.sets.sets import Interval +from sympy.external import import_module +from sympy.stats import Beta, Chi, Normal, Gamma, Exponential, LogNormal, Pareto, ChiSquared, Uniform, sample, \ + BetaPrime, Cauchy, GammaInverse, GaussianInverse, StudentT, Weibull, density, ContinuousRV, FDistribution, \ + Gumbel, Laplace, Logistic, Rayleigh, Triangular +from sympy.testing.pytest import skip, raises + + +def test_sample_numpy(): + distribs_numpy = [ + Beta("B", 1, 1), + Normal("N", 0, 1), + Gamma("G", 2, 7), + Exponential("E", 2), + LogNormal("LN", 0, 1), + Pareto("P", 1, 1), + ChiSquared("CS", 2), + Uniform("U", 0, 1), + FDistribution("FD", 1, 2), + Gumbel("GB", 1, 2), + Laplace("L", 1, 2), + Logistic("LO", 1, 2), + Rayleigh("R", 1), + Triangular("T", 1, 2, 2), + ] + size = 3 + numpy = import_module('numpy') + if not numpy: + skip('Numpy is not installed. Abort tests for _sample_numpy.') + else: + for X in distribs_numpy: + samps = sample(X, size=size, library='numpy') + for sam in samps: + assert sam in X.pspace.domain.set + raises(NotImplementedError, + lambda: sample(Chi("C", 1), library='numpy')) + raises(NotImplementedError, + lambda: Chi("C", 1).pspace.distribution.sample(library='tensorflow')) + + +def test_sample_scipy(): + distribs_scipy = [ + Beta("B", 1, 1), + BetaPrime("BP", 1, 1), + Cauchy("C", 1, 1), + Chi("C", 1), + Normal("N", 0, 1), + Gamma("G", 2, 7), + GammaInverse("GI", 1, 1), + GaussianInverse("GUI", 1, 1), + Exponential("E", 2), + LogNormal("LN", 0, 1), + Pareto("P", 1, 1), + StudentT("S", 2), + ChiSquared("CS", 2), + Uniform("U", 0, 1) + ] + size = 3 + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests for _sample_scipy.') + else: + for X in distribs_scipy: + samps = sample(X, size=size, library='scipy') + samps2 = sample(X, size=(2, 2), library='scipy') + for sam in samps: + assert sam in X.pspace.domain.set + for i in range(2): + for j in range(2): + assert samps2[i][j] in X.pspace.domain.set + + +def test_sample_pymc(): + distribs_pymc = [ + Beta("B", 1, 1), + Cauchy("C", 1, 1), + Normal("N", 0, 1), + Gamma("G", 2, 7), + GaussianInverse("GI", 1, 1), + Exponential("E", 2), + LogNormal("LN", 0, 1), + Pareto("P", 1, 1), + ChiSquared("CS", 2), + Uniform("U", 0, 1) + ] + size = 3 + pymc = import_module('pymc') + if not pymc: + skip('PyMC is not installed. Abort tests for _sample_pymc.') + else: + for X in distribs_pymc: + samps = sample(X, size=size, library='pymc') + for sam in samps: + assert sam in X.pspace.domain.set + raises(NotImplementedError, + lambda: sample(Chi("C", 1), library='pymc')) + + +def test_sampling_gamma_inverse(): + scipy = import_module('scipy') + if not scipy: + skip('Scipy not installed. Abort tests for sampling of gamma inverse.') + X = GammaInverse("x", 1, 1) + assert sample(X) in X.pspace.domain.set + + +def test_lognormal_sampling(): + # Right now, only density function and sampling works + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + for i in range(3): + X = LogNormal('x', i, 1) + assert sample(X) in X.pspace.domain.set + + size = 5 + samps = sample(X, size=size) + for samp in samps: + assert samp in X.pspace.domain.set + + +def test_sampling_gaussian_inverse(): + scipy = import_module('scipy') + if not scipy: + skip('Scipy not installed. Abort tests for sampling of Gaussian inverse.') + X = GaussianInverse("x", 1, 1) + assert sample(X, library='scipy') in X.pspace.domain.set + + +def test_prefab_sampling(): + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + N = Normal('X', 0, 1) + L = LogNormal('L', 0, 1) + E = Exponential('Ex', 1) + P = Pareto('P', 1, 3) + W = Weibull('W', 1, 1) + U = Uniform('U', 0, 1) + B = Beta('B', 2, 5) + G = Gamma('G', 1, 3) + + variables = [N, L, E, P, W, U, B, G] + niter = 10 + size = 5 + for var in variables: + for _ in range(niter): + assert sample(var) in var.pspace.domain.set + samps = sample(var, size=size) + for samp in samps: + assert samp in var.pspace.domain.set + + +def test_sample_continuous(): + z = Symbol('z') + Z = ContinuousRV(z, exp(-z), set=Interval(0, oo)) + assert density(Z)(-1) == 0 + + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + assert sample(Z) in Z.pspace.domain.set + sym, val = list(Z.pspace.sample().items())[0] + assert sym == Z and val in Interval(0, oo) + + libraries = ['scipy', 'numpy', 'pymc'] + for lib in libraries: + try: + imported_lib = import_module(lib) + if imported_lib: + s0, s1, s2 = [], [], [] + s0 = sample(Z, size=10, library=lib, seed=0) + s1 = sample(Z, size=10, library=lib, seed=0) + s2 = sample(Z, size=10, library=lib, seed=1) + assert all(s0 == s1) + assert all(s1 != s2) + except NotImplementedError: + continue diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_discrete_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_discrete_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..90d385cd599222fd7da7c1559b619bafbeb01831 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_discrete_rv.py @@ -0,0 +1,109 @@ +from sympy.core.singleton import S +from sympy.core.symbol import Symbol +from sympy.external import import_module +from sympy.stats import ( + Geometric, + Poisson, + Zeta, + sample, + Skellam, + Logarithmic, + NegativeBinomial, + YuleSimon, + DiscreteRV, +) +from sympy.testing.pytest import skip, raises, slow + + +def test_sample_numpy(): + distribs_numpy = [ + Geometric('G', 0.5), + Poisson('P', 1), + Zeta('Z', 2) + ] + size = 3 + numpy = import_module('numpy') + if not numpy: + skip('Numpy is not installed. Abort tests for _sample_numpy.') + else: + for X in distribs_numpy: + samps = sample(X, size=size, library='numpy') + for sam in samps: + assert sam in X.pspace.domain.set + raises(NotImplementedError, + lambda: sample(Skellam('S', 1, 1), library='numpy')) + raises(NotImplementedError, + lambda: Skellam('S', 1, 1).pspace.distribution.sample(library='tensorflow')) + + +def test_sample_scipy(): + p = S(2)/3 + x = Symbol('x', integer=True, positive=True) + pdf = p*(1 - p)**(x - 1) # pdf of Geometric Distribution + distribs_scipy = [ + DiscreteRV(x, pdf, set=S.Naturals), + Geometric('G', 0.5), + Logarithmic('L', 0.5), + NegativeBinomial('N', 5, 0.4), + Poisson('P', 1), + Skellam('S', 1, 1), + YuleSimon('Y', 1), + Zeta('Z', 2) + ] + size = 3 + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests for _sample_scipy.') + else: + for X in distribs_scipy: + samps = sample(X, size=size, library='scipy') + samps2 = sample(X, size=(2, 2), library='scipy') + for sam in samps: + assert sam in X.pspace.domain.set + for i in range(2): + for j in range(2): + assert samps2[i][j] in X.pspace.domain.set + + +def test_sample_pymc(): + distribs_pymc = [ + Geometric('G', 0.5), + Poisson('P', 1), + NegativeBinomial('N', 5, 0.4) + ] + size = 3 + pymc = import_module('pymc') + if not pymc: + skip('PyMC is not installed. Abort tests for _sample_pymc.') + else: + for X in distribs_pymc: + samps = sample(X, size=size, library='pymc') + for sam in samps: + assert sam in X.pspace.domain.set + raises(NotImplementedError, + lambda: sample(Skellam('S', 1, 1), library='pymc')) + +@slow +def test_sample_discrete(): + X = Geometric('X', S.Half) + scipy = import_module('scipy') + if not scipy: + skip('Scipy not installed. Abort tests') + assert sample(X) in X.pspace.domain.set + samps = sample(X, size=2) # This takes long time if ran without scipy + for samp in samps: + assert samp in X.pspace.domain.set + + libraries = ['scipy', 'numpy', 'pymc'] + for lib in libraries: + try: + imported_lib = import_module(lib) + if imported_lib: + s0, s1, s2 = [], [], [] + s0 = sample(X, size=10, library=lib, seed=0) + s1 = sample(X, size=10, library=lib, seed=0) + s2 = sample(X, size=10, library=lib, seed=1) + assert all(s0 == s1) + assert not all(s1 == s2) + except NotImplementedError: + continue diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_finite_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_finite_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..96cabe0ff4aaa5977e16600217fbbdeb08b962ae --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/sampling/tests/test_sample_finite_rv.py @@ -0,0 +1,94 @@ +from sympy.core.numbers import Rational +from sympy.core.singleton import S +from sympy.external import import_module +from sympy.stats import Binomial, sample, Die, FiniteRV, DiscreteUniform, Bernoulli, BetaBinomial, Hypergeometric, \ + Rademacher +from sympy.testing.pytest import skip, raises + +def test_given_sample(): + X = Die('X', 6) + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + assert sample(X, X > 5) == 6 + +def test_sample_numpy(): + distribs_numpy = [ + Binomial("B", 5, 0.4), + Hypergeometric("H", 2, 1, 1) + ] + size = 3 + numpy = import_module('numpy') + if not numpy: + skip('Numpy is not installed. Abort tests for _sample_numpy.') + else: + for X in distribs_numpy: + samps = sample(X, size=size, library='numpy') + for sam in samps: + assert sam in X.pspace.domain.set + raises(NotImplementedError, + lambda: sample(Die("D"), library='numpy')) + raises(NotImplementedError, + lambda: Die("D").pspace.sample(library='tensorflow')) + + +def test_sample_scipy(): + distribs_scipy = [ + FiniteRV('F', {1: S.Half, 2: Rational(1, 4), 3: Rational(1, 4)}), + DiscreteUniform("Y", list(range(5))), + Die("D"), + Bernoulli("Be", 0.3), + Binomial("Bi", 5, 0.4), + BetaBinomial("Bb", 2, 1, 1), + Hypergeometric("H", 1, 1, 1), + Rademacher("R") + ] + + size = 3 + scipy = import_module('scipy') + if not scipy: + skip('Scipy not installed. Abort tests for _sample_scipy.') + else: + for X in distribs_scipy: + samps = sample(X, size=size) + samps2 = sample(X, size=(2, 2)) + for sam in samps: + assert sam in X.pspace.domain.set + for i in range(2): + for j in range(2): + assert samps2[i][j] in X.pspace.domain.set + + +def test_sample_pymc(): + distribs_pymc = [ + Bernoulli('B', 0.2), + Binomial('N', 5, 0.4) + ] + size = 3 + pymc = import_module('pymc') + if not pymc: + skip('PyMC is not installed. Abort tests for _sample_pymc.') + else: + for X in distribs_pymc: + samps = sample(X, size=size, library='pymc') + for sam in samps: + assert sam in X.pspace.domain.set + raises(NotImplementedError, + lambda: (sample(Die("D"), library='pymc'))) + + +def test_sample_seed(): + F = FiniteRV('F', {1: S.Half, 2: Rational(1, 4), 3: Rational(1, 4)}) + size = 10 + libraries = ['scipy', 'numpy', 'pymc'] + for lib in libraries: + try: + imported_lib = import_module(lib) + if imported_lib: + s0 = sample(F, size=size, library=lib, seed=0) + s1 = sample(F, size=size, library=lib, seed=0) + s2 = sample(F, size=size, library=lib, seed=1) + assert all(s0 == s1) + assert not all(s1 == s2) + except NotImplementedError: + continue diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/stochastic_process.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/stochastic_process.py new file mode 100644 index 0000000000000000000000000000000000000000..bfb0e759c66be892ae38ddda004dfe928f683fee --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/stochastic_process.py @@ -0,0 +1,66 @@ +from sympy.core.basic import Basic +from sympy.stats.joint_rv import ProductPSpace +from sympy.stats.rv import ProductDomain, _symbol_converter, Distribution + + +class StochasticPSpace(ProductPSpace): + """ + Represents probability space of stochastic processes + and their random variables. Contains mechanics to do + computations for queries of stochastic processes. + + Explanation + =========== + + Initialized by symbol, the specific process and + distribution(optional) if the random indexed symbols + of the process follows any specific distribution, like, + in Bernoulli Process, each random indexed symbol follows + Bernoulli distribution. For processes with memory, this + parameter should not be passed. + """ + + def __new__(cls, sym, process, distribution=None): + sym = _symbol_converter(sym) + from sympy.stats.stochastic_process_types import StochasticProcess + if not isinstance(process, StochasticProcess): + raise TypeError("`process` must be an instance of StochasticProcess.") + if distribution is None: + distribution = Distribution() + return Basic.__new__(cls, sym, process, distribution) + + @property + def process(self): + """ + The associated stochastic process. + """ + return self.args[1] + + @property + def domain(self): + return ProductDomain(self.process.index_set, + self.process.state_space) + + @property + def symbol(self): + return self.args[0] + + @property + def distribution(self): + return self.args[2] + + def probability(self, condition, given_condition=None, evaluate=True, **kwargs): + """ + Transfers the task of handling queries to the specific stochastic + process because every process has their own logic of handling such + queries. + """ + return self.process.probability(condition, given_condition, evaluate, **kwargs) + + def compute_expectation(self, expr, condition=None, evaluate=True, **kwargs): + """ + Transfers the task of handling queries to the specific stochastic + process because every process has their own logic of handling such + queries. + """ + return self.process.expectation(expr, condition, evaluate, **kwargs) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/stochastic_process_types.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/stochastic_process_types.py new file mode 100644 index 0000000000000000000000000000000000000000..7387cd3dbcf6defb3b7e475f542d04ecef6fecf6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/stochastic_process_types.py @@ -0,0 +1,2383 @@ +from __future__ import annotations +import random +import itertools +from typing import Sequence as tSequence +from sympy.concrete.summations import Sum +from sympy.core.add import Add +from sympy.core.basic import Basic +from sympy.core.cache import cacheit +from sympy.core.containers import Tuple +from sympy.core.expr import Expr +from sympy.core.function import (Function, Lambda) +from sympy.core.mul import Mul +from sympy.core.intfunc import igcd +from sympy.core.numbers import (Integer, Rational, oo, pi) +from sympy.core.relational import (Eq, Ge, Gt, Le, Lt, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol) +from sympy.functions.combinatorial.factorials import factorial +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.integers import ceiling +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.gamma_functions import gamma +from sympy.logic.boolalg import (And, Not, Or) +from sympy.matrices.exceptions import NonSquareMatrixError +from sympy.matrices.dense import (Matrix, eye, ones, zeros) +from sympy.matrices.expressions.blockmatrix import BlockMatrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.special import Identity +from sympy.matrices.immutable import ImmutableMatrix +from sympy.sets.conditionset import ConditionSet +from sympy.sets.contains import Contains +from sympy.sets.fancysets import Range +from sympy.sets.sets import (FiniteSet, Intersection, Interval, Set, Union) +from sympy.solvers.solveset import linsolve +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.core.relational import Relational +from sympy.logic.boolalg import Boolean +from sympy.utilities.exceptions import sympy_deprecation_warning +from sympy.utilities.iterables import strongly_connected_components +from sympy.stats.joint_rv import JointDistribution +from sympy.stats.joint_rv_types import JointDistributionHandmade +from sympy.stats.rv import (RandomIndexedSymbol, random_symbols, RandomSymbol, + _symbol_converter, _value_check, pspace, given, + dependent, is_random, sample_iter, Distribution, + Density) +from sympy.stats.stochastic_process import StochasticPSpace +from sympy.stats.symbolic_probability import Probability, Expectation +from sympy.stats.frv_types import Bernoulli, BernoulliDistribution, FiniteRV +from sympy.stats.drv_types import Poisson, PoissonDistribution +from sympy.stats.crv_types import Normal, NormalDistribution, Gamma, GammaDistribution +from sympy.core.sympify import _sympify, sympify + +EmptySet = S.EmptySet + +__all__ = [ + 'StochasticProcess', + 'DiscreteTimeStochasticProcess', + 'DiscreteMarkovChain', + 'TransitionMatrixOf', + 'StochasticStateSpaceOf', + 'GeneratorMatrixOf', + 'ContinuousMarkovChain', + 'BernoulliProcess', + 'PoissonProcess', + 'WienerProcess', + 'GammaProcess' +] + + +@is_random.register(Indexed) +def _(x): + return is_random(x.base) + +@is_random.register(RandomIndexedSymbol) # type: ignore +def _(x): + return True + +def _set_converter(itr): + """ + Helper function for converting list/tuple/set to Set. + If parameter is not an instance of list/tuple/set then + no operation is performed. + + Returns + ======= + + Set + The argument converted to Set. + + + Raises + ====== + + TypeError + If the argument is not an instance of list/tuple/set. + """ + if isinstance(itr, (list, tuple, set)): + itr = FiniteSet(*itr) + if not isinstance(itr, Set): + raise TypeError("%s is not an instance of list/tuple/set."%(itr)) + return itr + +def _state_converter(itr: tSequence) -> Tuple | Range: + """ + Helper function for converting list/tuple/set/Range/Tuple/FiniteSet + to tuple/Range. + """ + itr_ret: Tuple | Range + + if isinstance(itr, (Tuple, set, FiniteSet)): + itr_ret = Tuple(*(sympify(i) if isinstance(i, str) else i for i in itr)) + + elif isinstance(itr, (list, tuple)): + # check if states are unique + if len(set(itr)) != len(itr): + raise ValueError('The state space must have unique elements.') + itr_ret = Tuple(*(sympify(i) if isinstance(i, str) else i for i in itr)) + + elif isinstance(itr, Range): + # the only ordered set in SymPy I know of + # try to convert to tuple + try: + itr_ret = Tuple(*(sympify(i) if isinstance(i, str) else i for i in itr)) + except (TypeError, ValueError): + itr_ret = itr + + else: + raise TypeError("%s is not an instance of list/tuple/set/Range/Tuple/FiniteSet." % (itr)) + return itr_ret + +def _sym_sympify(arg): + """ + Converts an arbitrary expression to a type that can be used inside SymPy. + As generally strings are unwise to use in the expressions, + it returns the Symbol of argument if the string type argument is passed. + + Parameters + ========= + + arg: The parameter to be converted to be used in SymPy. + + Returns + ======= + + The converted parameter. + + """ + if isinstance(arg, str): + return Symbol(arg) + else: + return _sympify(arg) + +def _matrix_checks(matrix): + if not isinstance(matrix, (Matrix, MatrixSymbol, ImmutableMatrix)): + raise TypeError("Transition probabilities either should " + "be a Matrix or a MatrixSymbol.") + if matrix.shape[0] != matrix.shape[1]: + raise NonSquareMatrixError("%s is not a square matrix"%(matrix)) + if isinstance(matrix, Matrix): + matrix = ImmutableMatrix(matrix.tolist()) + return matrix + +class StochasticProcess(Basic): + """ + Base class for all the stochastic processes whether + discrete or continuous. + + Parameters + ========== + + sym: Symbol or str + state_space: Set + The state space of the stochastic process, by default S.Reals. + For discrete sets it is zero indexed. + + See Also + ======== + + DiscreteTimeStochasticProcess + """ + + index_set = S.Reals + + def __new__(cls, sym, state_space=S.Reals, **kwargs): + sym = _symbol_converter(sym) + state_space = _set_converter(state_space) + return Basic.__new__(cls, sym, state_space) + + @property + def symbol(self): + return self.args[0] + + @property + def state_space(self) -> FiniteSet | Range: + if not isinstance(self.args[1], (FiniteSet, Range)): + assert isinstance(self.args[1], Tuple) + return FiniteSet(*self.args[1]) + return self.args[1] + + def _deprecation_warn_distribution(self): + sympy_deprecation_warning( + """ + Calling the distribution method with a RandomIndexedSymbol + argument, like X.distribution(X(t)) is deprecated. Instead, call + distribution() with the given timestamp, like + + X.distribution(t) + """, + deprecated_since_version="1.7.1", + active_deprecations_target="deprecated-distribution-randomindexedsymbol", + stacklevel=4, + ) + + def distribution(self, key=None): + if key is None: + self._deprecation_warn_distribution() + return Distribution() + + def density(self, x): + return Density() + + def __call__(self, time): + """ + Overridden in ContinuousTimeStochasticProcess. + """ + raise NotImplementedError("Use [] for indexing discrete time stochastic process.") + + def __getitem__(self, time): + """ + Overridden in DiscreteTimeStochasticProcess. + """ + raise NotImplementedError("Use () for indexing continuous time stochastic process.") + + def probability(self, condition): + raise NotImplementedError() + + def joint_distribution(self, *args): + """ + Computes the joint distribution of the random indexed variables. + + Parameters + ========== + + args: iterable + The finite list of random indexed variables/the key of a stochastic + process whose joint distribution has to be computed. + + Returns + ======= + + JointDistribution + The joint distribution of the list of random indexed variables. + An unevaluated object is returned if it is not possible to + compute the joint distribution. + + Raises + ====== + + ValueError: When the arguments passed are not of type RandomIndexSymbol + or Number. + """ + args = list(args) + for i, arg in enumerate(args): + if S(arg).is_Number: + if self.index_set.is_subset(S.Integers): + args[i] = self.__getitem__(arg) + else: + args[i] = self.__call__(arg) + elif not isinstance(arg, RandomIndexedSymbol): + raise ValueError("Expected a RandomIndexedSymbol or " + "key not %s"%(type(arg))) + + if args[0].pspace.distribution == Distribution(): + return JointDistribution(*args) + density = Lambda(tuple(args), + expr=Mul.fromiter(arg.pspace.process.density(arg) for arg in args)) + return JointDistributionHandmade(density) + + def expectation(self, condition, given_condition): + raise NotImplementedError("Abstract method for expectation queries.") + + def sample(self): + raise NotImplementedError("Abstract method for sampling queries.") + +class DiscreteTimeStochasticProcess(StochasticProcess): + """ + Base class for all discrete stochastic processes. + """ + def __getitem__(self, time): + """ + For indexing discrete time stochastic processes. + + Returns + ======= + + RandomIndexedSymbol + """ + time = sympify(time) + if not time.is_symbol and time not in self.index_set: + raise IndexError("%s is not in the index set of %s"%(time, self.symbol)) + idx_obj = Indexed(self.symbol, time) + pspace_obj = StochasticPSpace(self.symbol, self, self.distribution(time)) + return RandomIndexedSymbol(idx_obj, pspace_obj) + +class ContinuousTimeStochasticProcess(StochasticProcess): + """ + Base class for all continuous time stochastic process. + """ + def __call__(self, time): + """ + For indexing continuous time stochastic processes. + + Returns + ======= + + RandomIndexedSymbol + """ + time = sympify(time) + if not time.is_symbol and time not in self.index_set: + raise IndexError("%s is not in the index set of %s"%(time, self.symbol)) + func_obj = Function(self.symbol)(time) + pspace_obj = StochasticPSpace(self.symbol, self, self.distribution(time)) + return RandomIndexedSymbol(func_obj, pspace_obj) + +class TransitionMatrixOf(Boolean): + """ + Assumes that the matrix is the transition matrix + of the process. + """ + + def __new__(cls, process, matrix): + if not isinstance(process, DiscreteMarkovChain): + raise ValueError("Currently only DiscreteMarkovChain " + "support TransitionMatrixOf.") + matrix = _matrix_checks(matrix) + return Basic.__new__(cls, process, matrix) + + process = property(lambda self: self.args[0]) + matrix = property(lambda self: self.args[1]) + +class GeneratorMatrixOf(TransitionMatrixOf): + """ + Assumes that the matrix is the generator matrix + of the process. + """ + + def __new__(cls, process, matrix): + if not isinstance(process, ContinuousMarkovChain): + raise ValueError("Currently only ContinuousMarkovChain " + "support GeneratorMatrixOf.") + matrix = _matrix_checks(matrix) + return Basic.__new__(cls, process, matrix) + +class StochasticStateSpaceOf(Boolean): + + def __new__(cls, process, state_space): + if not isinstance(process, (DiscreteMarkovChain, ContinuousMarkovChain)): + raise ValueError("Currently only DiscreteMarkovChain and ContinuousMarkovChain " + "support StochasticStateSpaceOf.") + state_space = _state_converter(state_space) + if isinstance(state_space, Range): + ss_size = ceiling((state_space.stop - state_space.start) / state_space.step) + else: + ss_size = len(state_space) + state_index = Range(ss_size) + return Basic.__new__(cls, process, state_index) + + process = property(lambda self: self.args[0]) + state_index = property(lambda self: self.args[1]) + +class MarkovProcess(StochasticProcess): + """ + Contains methods that handle queries + common to Markov processes. + """ + + @property + def number_of_states(self) -> Integer | Symbol: + """ + The number of states in the Markov Chain. + """ + return _sympify(self.args[2].shape[0]) # type: ignore + + @property + def _state_index(self): + """ + Returns state index as Range. + """ + return self.args[1] + + @classmethod + def _sanity_checks(cls, state_space, trans_probs): + # Try to never have None as state_space or trans_probs. + # This helps a lot if we get it done at the start. + if (state_space is None) and (trans_probs is None): + _n = Dummy('n', integer=True, nonnegative=True) + state_space = _state_converter(Range(_n)) + trans_probs = _matrix_checks(MatrixSymbol('_T', _n, _n)) + + elif state_space is None: + trans_probs = _matrix_checks(trans_probs) + state_space = _state_converter(Range(trans_probs.shape[0])) + + elif trans_probs is None: + state_space = _state_converter(state_space) + if isinstance(state_space, Range): + _n = ceiling((state_space.stop - state_space.start) / state_space.step) + else: + _n = len(state_space) + trans_probs = MatrixSymbol('_T', _n, _n) + + else: + state_space = _state_converter(state_space) + trans_probs = _matrix_checks(trans_probs) + # Range object doesn't want to give a symbolic size + # so we do it ourselves. + if isinstance(state_space, Range): + ss_size = ceiling((state_space.stop - state_space.start) / state_space.step) + else: + ss_size = len(state_space) + if ss_size != trans_probs.shape[0]: + raise ValueError('The size of the state space and the number of ' + 'rows of the transition matrix must be the same.') + + return state_space, trans_probs + + def _extract_information(self, given_condition): + """ + Helper function to extract information, like, + transition matrix/generator matrix, state space, etc. + """ + if isinstance(self, DiscreteMarkovChain): + trans_probs = self.transition_probabilities + state_index = self._state_index + elif isinstance(self, ContinuousMarkovChain): + trans_probs = self.generator_matrix + state_index = self._state_index + if isinstance(given_condition, And): + gcs = given_condition.args + given_condition = S.true + for gc in gcs: + if isinstance(gc, TransitionMatrixOf): + trans_probs = gc.matrix + if isinstance(gc, StochasticStateSpaceOf): + state_index = gc.state_index + if isinstance(gc, Relational): + given_condition = given_condition & gc + if isinstance(given_condition, TransitionMatrixOf): + trans_probs = given_condition.matrix + given_condition = S.true + if isinstance(given_condition, StochasticStateSpaceOf): + state_index = given_condition.state_index + given_condition = S.true + return trans_probs, state_index, given_condition + + def _check_trans_probs(self, trans_probs, row_sum=1): + """ + Helper function for checking the validity of transition + probabilities. + """ + if not isinstance(trans_probs, MatrixSymbol): + rows = trans_probs.tolist() + for row in rows: + if (sum(row) - row_sum) != 0: + raise ValueError("Values in a row must sum to %s. " + "If you are using Float or floats then please use Rational."%(row_sum)) + + def _work_out_state_index(self, state_index, given_condition, trans_probs): + """ + Helper function to extract state space if there + is a random symbol in the given condition. + """ + # if given condition is None, then there is no need to work out + # state_space from random variables + if given_condition != None: + rand_var = list(given_condition.atoms(RandomSymbol) - + given_condition.atoms(RandomIndexedSymbol)) + if len(rand_var) == 1: + state_index = rand_var[0].pspace.set + + # `not None` is `True`. So the old test fails for symbolic sizes. + # Need to build the statement differently. + sym_cond = not self.number_of_states.is_Integer + cond1 = not sym_cond and len(state_index) != trans_probs.shape[0] + if cond1: + raise ValueError("state space is not compatible with the transition probabilities.") + if not isinstance(trans_probs.shape[0], Symbol): + state_index = FiniteSet(*range(trans_probs.shape[0])) + return state_index + + @cacheit + def _preprocess(self, given_condition, evaluate): + """ + Helper function for pre-processing the information. + """ + is_insufficient = False + + if not evaluate: # avoid pre-processing if the result is not to be evaluated + return (True, None, None, None) + + # extracting transition matrix and state space + trans_probs, state_index, given_condition = self._extract_information(given_condition) + + # given_condition does not have sufficient information + # for computations + if trans_probs is None or \ + given_condition is None: + is_insufficient = True + else: + # checking transition probabilities + if isinstance(self, DiscreteMarkovChain): + self._check_trans_probs(trans_probs, row_sum=1) + elif isinstance(self, ContinuousMarkovChain): + self._check_trans_probs(trans_probs, row_sum=0) + + # working out state space + state_index = self._work_out_state_index(state_index, given_condition, trans_probs) + + return is_insufficient, trans_probs, state_index, given_condition + + def replace_with_index(self, condition): + if isinstance(condition, Relational): + lhs, rhs = condition.lhs, condition.rhs + if not isinstance(lhs, RandomIndexedSymbol): + lhs, rhs = rhs, lhs + condition = type(condition)(self.index_of.get(lhs, lhs), + self.index_of.get(rhs, rhs)) + return condition + + def probability(self, condition, given_condition=None, evaluate=True, **kwargs): + """ + Handles probability queries for Markov process. + + Parameters + ========== + + condition: Relational + given_condition: Relational/And + + Returns + ======= + Probability + If the information is not sufficient. + Expr + In all other cases. + + Note + ==== + Any information passed at the time of query overrides + any information passed at the time of object creation like + transition probabilities, state space. + Pass the transition matrix using TransitionMatrixOf, + generator matrix using GeneratorMatrixOf and state space + using StochasticStateSpaceOf in given_condition using & or And. + """ + check, mat, state_index, new_given_condition = \ + self._preprocess(given_condition, evaluate) + + rv = list(condition.atoms(RandomIndexedSymbol)) + symbolic = False + for sym in rv: + if sym.key.is_symbol: + symbolic = True + break + + if check: + return Probability(condition, new_given_condition) + + if isinstance(self, ContinuousMarkovChain): + trans_probs = self.transition_probabilities(mat) + elif isinstance(self, DiscreteMarkovChain): + trans_probs = mat + condition = self.replace_with_index(condition) + given_condition = self.replace_with_index(given_condition) + new_given_condition = self.replace_with_index(new_given_condition) + + if isinstance(condition, Relational): + if isinstance(new_given_condition, And): + gcs = new_given_condition.args + else: + gcs = (new_given_condition, ) + min_key_rv = list(new_given_condition.atoms(RandomIndexedSymbol)) + + if len(min_key_rv): + min_key_rv = min_key_rv[0] + for r in rv: + if min_key_rv.key.is_symbol or r.key.is_symbol: + continue + if min_key_rv.key > r.key: + return Probability(condition) + else: + min_key_rv = None + return Probability(condition) + + if symbolic: + return self._symbolic_probability(condition, new_given_condition, rv, min_key_rv) + + if len(rv) > 1: + rv[0] = condition.lhs + rv[1] = condition.rhs + if rv[0].key < rv[1].key: + rv[0], rv[1] = rv[1], rv[0] + if isinstance(condition, Gt): + condition = Lt(condition.lhs, condition.rhs) + elif isinstance(condition, Lt): + condition = Gt(condition.lhs, condition.rhs) + elif isinstance(condition, Ge): + condition = Le(condition.lhs, condition.rhs) + elif isinstance(condition, Le): + condition = Ge(condition.lhs, condition.rhs) + s = Rational(0, 1) + n = len(self.state_space) + + if isinstance(condition, (Eq, Ne)): + for i in range(0, n): + s += self.probability(Eq(rv[0], i), Eq(rv[1], i)) * self.probability(Eq(rv[1], i), new_given_condition) + return s if isinstance(condition, Eq) else 1 - s + else: + upper = 0 + greater = False + if isinstance(condition, (Ge, Lt)): + upper = 1 + if isinstance(condition, (Ge, Gt)): + greater = True + + for i in range(0, n): + if i <= n//2: + for j in range(0, i + upper): + s += self.probability(Eq(rv[0], i), Eq(rv[1], j)) * self.probability(Eq(rv[1], j), new_given_condition) + else: + s += self.probability(Eq(rv[0], i), new_given_condition) + for j in range(i + upper, n): + s -= self.probability(Eq(rv[0], i), Eq(rv[1], j)) * self.probability(Eq(rv[1], j), new_given_condition) + return s if greater else 1 - s + + rv = rv[0] + states = condition.as_set() + prob, gstate = {}, None + for gc in gcs: + if gc.has(min_key_rv): + if gc.has(Probability): + p, gp = (gc.rhs, gc.lhs) if isinstance(gc.lhs, Probability) \ + else (gc.lhs, gc.rhs) + gr = gp.args[0] + gset = Intersection(gr.as_set(), state_index) + gstate = list(gset)[0] + prob[gset] = p + else: + _, gstate = (gc.lhs.key, gc.rhs) if isinstance(gc.lhs, RandomIndexedSymbol) \ + else (gc.rhs.key, gc.lhs) + + if not all(k in self.index_set for k in (rv.key, min_key_rv.key)): + raise IndexError("The timestamps of the process are not in it's index set.") + states = Intersection(states, state_index) if not isinstance(self.number_of_states, Symbol) else states + for state in Union(states, FiniteSet(gstate)): + if not state.is_Integer or Ge(state, mat.shape[0]) is True: + raise IndexError("No information is available for (%s, %s) in " + "transition probabilities of shape, (%s, %s). " + "State space is zero indexed." + %(gstate, state, mat.shape[0], mat.shape[1])) + if prob: + gstates = Union(*prob.keys()) + if len(gstates) == 1: + gstate = list(gstates)[0] + gprob = list(prob.values())[0] + prob[gstates] = gprob + elif len(gstates) == len(state_index) - 1: + gstate = list(state_index - gstates)[0] + gprob = S.One - sum(prob.values()) + prob[state_index - gstates] = gprob + else: + raise ValueError("Conflicting information.") + else: + gprob = S.One + + if min_key_rv == rv: + return sum(prob[FiniteSet(state)] for state in states) + if isinstance(self, ContinuousMarkovChain): + return gprob * sum(trans_probs(rv.key - min_key_rv.key).__getitem__((gstate, state)) + for state in states) + if isinstance(self, DiscreteMarkovChain): + return gprob * sum((trans_probs**(rv.key - min_key_rv.key)).__getitem__((gstate, state)) + for state in states) + + if isinstance(condition, Not): + expr = condition.args[0] + return S.One - self.probability(expr, given_condition, evaluate, **kwargs) + + if isinstance(condition, And): + compute_later, state2cond, conds = [], {}, condition.args + for expr in conds: + if isinstance(expr, Relational): + ris = list(expr.atoms(RandomIndexedSymbol))[0] + if state2cond.get(ris, None) is None: + state2cond[ris] = S.true + state2cond[ris] &= expr + else: + compute_later.append(expr) + ris = [] + for ri in state2cond: + ris.append(ri) + cset = Intersection(state2cond[ri].as_set(), state_index) + if len(cset) == 0: + return S.Zero + state2cond[ri] = cset.as_relational(ri) + sorted_ris = sorted(ris, key=lambda ri: ri.key) + prod = self.probability(state2cond[sorted_ris[0]], given_condition, evaluate, **kwargs) + for i in range(1, len(sorted_ris)): + ri, prev_ri = sorted_ris[i], sorted_ris[i-1] + if not isinstance(state2cond[ri], Eq): + raise ValueError("The process is in multiple states at %s, unable to determine the probability."%(ri)) + mat_of = TransitionMatrixOf(self, mat) if isinstance(self, DiscreteMarkovChain) else GeneratorMatrixOf(self, mat) + prod *= self.probability(state2cond[ri], state2cond[prev_ri] + & mat_of + & StochasticStateSpaceOf(self, state_index), + evaluate, **kwargs) + for expr in compute_later: + prod *= self.probability(expr, given_condition, evaluate, **kwargs) + return prod + + if isinstance(condition, Or): + return sum(self.probability(expr, given_condition, evaluate, **kwargs) + for expr in condition.args) + + raise NotImplementedError("Mechanism for handling (%s, %s) queries hasn't been " + "implemented yet."%(condition, given_condition)) + + def _symbolic_probability(self, condition, new_given_condition, rv, min_key_rv): + #Function to calculate probability for queries with symbols + if isinstance(condition, Relational): + curr_state = new_given_condition.rhs if isinstance(new_given_condition.lhs, RandomIndexedSymbol) \ + else new_given_condition.lhs + next_state = condition.rhs if isinstance(condition.lhs, RandomIndexedSymbol) \ + else condition.lhs + + if isinstance(condition, (Eq, Ne)): + if isinstance(self, DiscreteMarkovChain): + P = self.transition_probabilities**(rv[0].key - min_key_rv.key) + else: + P = exp(self.generator_matrix*(rv[0].key - min_key_rv.key)) + prob = P[curr_state, next_state] if isinstance(condition, Eq) else 1 - P[curr_state, next_state] + return Piecewise((prob, rv[0].key > min_key_rv.key), (Probability(condition), True)) + else: + upper = 1 + greater = False + if isinstance(condition, (Ge, Lt)): + upper = 0 + if isinstance(condition, (Ge, Gt)): + greater = True + k = Dummy('k') + condition = Eq(condition.lhs, k) if isinstance(condition.lhs, RandomIndexedSymbol)\ + else Eq(condition.rhs, k) + total = Sum(self.probability(condition, new_given_condition), (k, next_state + upper, self.state_space._sup)) + return Piecewise((total, rv[0].key > min_key_rv.key), (Probability(condition), True)) if greater\ + else Piecewise((1 - total, rv[0].key > min_key_rv.key), (Probability(condition), True)) + else: + return Probability(condition, new_given_condition) + + def expectation(self, expr, condition=None, evaluate=True, **kwargs): + """ + Handles expectation queries for markov process. + + Parameters + ========== + + expr: RandomIndexedSymbol, Relational, Logic + Condition for which expectation has to be computed. Must + contain a RandomIndexedSymbol of the process. + condition: Relational, Logic + The given conditions under which computations should be done. + + Returns + ======= + + Expectation + Unevaluated object if computations cannot be done due to + insufficient information. + Expr + In all other cases when the computations are successful. + + Note + ==== + + Any information passed at the time of query overrides + any information passed at the time of object creation like + transition probabilities, state space. + + Pass the transition matrix using TransitionMatrixOf, + generator matrix using GeneratorMatrixOf and state space + using StochasticStateSpaceOf in given_condition using & or And. + """ + + check, mat, state_index, condition = \ + self._preprocess(condition, evaluate) + + if check: + return Expectation(expr, condition) + + rvs = random_symbols(expr) + if isinstance(expr, Expr) and isinstance(condition, Eq) \ + and len(rvs) == 1: + # handle queries similar to E(f(X[i]), Eq(X[i-m], )) + condition=self.replace_with_index(condition) + state_index=self.replace_with_index(state_index) + rv = list(rvs)[0] + lhsg, rhsg = condition.lhs, condition.rhs + if not isinstance(lhsg, RandomIndexedSymbol): + lhsg, rhsg = (rhsg, lhsg) + if rhsg not in state_index: + raise ValueError("%s state is not in the state space."%(rhsg)) + if rv.key < lhsg.key: + raise ValueError("Incorrect given condition is given, expectation " + "time %s < time %s"%(rv.key, rv.key)) + mat_of = TransitionMatrixOf(self, mat) if isinstance(self, DiscreteMarkovChain) else GeneratorMatrixOf(self, mat) + cond = condition & mat_of & \ + StochasticStateSpaceOf(self, state_index) + func = lambda s: self.probability(Eq(rv, s), cond) * expr.subs(rv, self._state_index[s]) + return sum(func(s) for s in state_index) + + raise NotImplementedError("Mechanism for handling (%s, %s) queries hasn't been " + "implemented yet."%(expr, condition)) + +class DiscreteMarkovChain(DiscreteTimeStochasticProcess, MarkovProcess): + """ + Represents a finite discrete time-homogeneous Markov chain. + + This type of Markov Chain can be uniquely characterised by + its (ordered) state space and its one-step transition probability + matrix. + + Parameters + ========== + + sym: + The name given to the Markov Chain + state_space: + Optional, by default, Range(n) + trans_probs: + Optional, by default, MatrixSymbol('_T', n, n) + + Examples + ======== + + >>> from sympy.stats import DiscreteMarkovChain, TransitionMatrixOf, P, E + >>> from sympy import Matrix, MatrixSymbol, Eq, symbols + >>> T = Matrix([[0.5, 0.2, 0.3],[0.2, 0.5, 0.3],[0.2, 0.3, 0.5]]) + >>> Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + >>> YS = DiscreteMarkovChain("Y") + + >>> Y.state_space + {0, 1, 2} + >>> Y.transition_probabilities + Matrix([ + [0.5, 0.2, 0.3], + [0.2, 0.5, 0.3], + [0.2, 0.3, 0.5]]) + >>> TS = MatrixSymbol('T', 3, 3) + >>> P(Eq(YS[3], 2), Eq(YS[1], 1) & TransitionMatrixOf(YS, TS)) + T[0, 2]*T[1, 0] + T[1, 1]*T[1, 2] + T[1, 2]*T[2, 2] + >>> P(Eq(Y[3], 2), Eq(Y[1], 1)).round(2) + 0.36 + + Probabilities will be calculated based on indexes rather + than state names. For example, with the Sunny-Cloudy-Rainy + model with string state names: + + >>> from sympy.core.symbol import Str + >>> Y = DiscreteMarkovChain("Y", [Str('Sunny'), Str('Cloudy'), Str('Rainy')], T) + >>> P(Eq(Y[3], 2), Eq(Y[1], 1)).round(2) + 0.36 + + This gives the same answer as the ``[0, 1, 2]`` state space. + Currently, there is no support for state names within probability + and expectation statements. Here is a work-around using ``Str``: + + >>> P(Eq(Str('Rainy'), Y[3]), Eq(Y[1], Str('Cloudy'))).round(2) + 0.36 + + Symbol state names can also be used: + + >>> sunny, cloudy, rainy = symbols('Sunny, Cloudy, Rainy') + >>> Y = DiscreteMarkovChain("Y", [sunny, cloudy, rainy], T) + >>> P(Eq(Y[3], rainy), Eq(Y[1], cloudy)).round(2) + 0.36 + + Expectations will be calculated as follows: + + >>> E(Y[3], Eq(Y[1], cloudy)) + 0.38*Cloudy + 0.36*Rainy + 0.26*Sunny + + Probability of expressions with multiple RandomIndexedSymbols + can also be calculated provided there is only 1 RandomIndexedSymbol + in the given condition. It is always better to use Rational instead + of floating point numbers for the probabilities in the + transition matrix to avoid errors. + + >>> from sympy import Gt, Le, Rational + >>> T = Matrix([[Rational(5, 10), Rational(3, 10), Rational(2, 10)], [Rational(2, 10), Rational(7, 10), Rational(1, 10)], [Rational(3, 10), Rational(3, 10), Rational(4, 10)]]) + >>> Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + >>> P(Eq(Y[3], Y[1]), Eq(Y[0], 0)).round(3) + 0.409 + >>> P(Gt(Y[3], Y[1]), Eq(Y[0], 0)).round(2) + 0.36 + >>> P(Le(Y[15], Y[10]), Eq(Y[8], 2)).round(7) + 0.6963328 + + Symbolic probability queries are also supported + + >>> a, b, c, d = symbols('a b c d') + >>> T = Matrix([[Rational(1, 10), Rational(4, 10), Rational(5, 10)], [Rational(3, 10), Rational(4, 10), Rational(3, 10)], [Rational(7, 10), Rational(2, 10), Rational(1, 10)]]) + >>> Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + >>> query = P(Eq(Y[a], b), Eq(Y[c], d)) + >>> query.subs({a:10, b:2, c:5, d:1}).round(4) + 0.3096 + >>> P(Eq(Y[10], 2), Eq(Y[5], 1)).evalf().round(4) + 0.3096 + >>> query_gt = P(Gt(Y[a], b), Eq(Y[c], d)) + >>> query_gt.subs({a:21, b:0, c:5, d:0}).evalf().round(5) + 0.64705 + >>> P(Gt(Y[21], 0), Eq(Y[5], 0)).round(5) + 0.64705 + + There is limited support for arbitrarily sized states: + + >>> n = symbols('n', nonnegative=True, integer=True) + >>> T = MatrixSymbol('T', n, n) + >>> Y = DiscreteMarkovChain("Y", trans_probs=T) + >>> Y.state_space + Range(0, n, 1) + >>> query = P(Eq(Y[a], b), Eq(Y[c], d)) + >>> query.subs({a:10, b:2, c:5, d:1}) + (T**5)[1, 2] + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Markov_chain#Discrete-time_Markov_chain + .. [2] https://web.archive.org/web/20201230182007/https://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/Chapter11.pdf + """ + index_set = S.Naturals0 + + def __new__(cls, sym, state_space=None, trans_probs=None): + sym = _symbol_converter(sym) + + state_space, trans_probs = MarkovProcess._sanity_checks(state_space, trans_probs) + + obj = Basic.__new__(cls, sym, state_space, trans_probs) # type: ignore + indices = {} + if isinstance(obj.number_of_states, Integer): + for index, state in enumerate(obj._state_index): + indices[state] = index + obj.index_of = indices + return obj + + @property + def transition_probabilities(self): + """ + Transition probabilities of discrete Markov chain, + either an instance of Matrix or MatrixSymbol. + """ + return self.args[2] + + def communication_classes(self) -> list[tuple[list[Basic], Boolean, Integer]]: + """ + Returns the list of communication classes that partition + the states of the markov chain. + + A communication class is defined to be a set of states + such that every state in that set is reachable from + every other state in that set. Due to its properties + this forms a class in the mathematical sense. + Communication classes are also known as recurrence + classes. + + Returns + ======= + + classes + The ``classes`` are a list of tuples. Each + tuple represents a single communication class + with its properties. The first element in the + tuple is the list of states in the class, the + second element is whether the class is recurrent + and the third element is the period of the + communication class. + + Examples + ======== + + >>> from sympy.stats import DiscreteMarkovChain + >>> from sympy import Matrix + >>> T = Matrix([[0, 1, 0], + ... [1, 0, 0], + ... [1, 0, 0]]) + >>> X = DiscreteMarkovChain('X', [1, 2, 3], T) + >>> classes = X.communication_classes() + >>> for states, is_recurrent, period in classes: + ... states, is_recurrent, period + ([1, 2], True, 2) + ([3], False, 1) + + From this we can see that states ``1`` and ``2`` + communicate, are recurrent and have a period + of 2. We can also see state ``3`` is transient + with a period of 1. + + Notes + ===== + + The algorithm used is of order ``O(n**2)`` where + ``n`` is the number of states in the markov chain. + It uses Tarjan's algorithm to find the classes + themselves and then it uses a breadth-first search + algorithm to find each class's periodicity. + Most of the algorithm's components approach ``O(n)`` + as the matrix becomes more and more sparse. + + References + ========== + + .. [1] https://web.archive.org/web/20220207032113/https://www.columbia.edu/~ww2040/4701Sum07/4701-06-Notes-MCII.pdf + .. [2] https://cecas.clemson.edu/~shierd/Shier/markov.pdf + .. [3] https://www.proquest.com/openview/4adc6a51d8371be5b0e4c7dff287fc70/1?pq-origsite=gscholar&cbl=2026366&diss=y + .. [4] https://www.mathworks.com/help/econ/dtmc.classify.html + """ + n = self.number_of_states + T = self.transition_probabilities + + if isinstance(T, MatrixSymbol): + raise NotImplementedError("Cannot perform the operation with a symbolic matrix.") + + # begin Tarjan's algorithm + V = Range(n) + # don't use state names. Rather use state + # indexes since we use them for matrix + # indexing here and later onward + E = [(i, j) for i in V for j in V if T[i, j] != 0] + classes = strongly_connected_components((V, E)) + # end Tarjan's algorithm + + recurrence = [] + periods = [] + for class_ in classes: + # begin recurrent check (similar to self._check_trans_probs()) + submatrix = T[class_, class_] # get the submatrix with those states + is_recurrent = S.true + rows = submatrix.tolist() + for row in rows: + if (sum(row) - 1) != 0: + is_recurrent = S.false + break + recurrence.append(is_recurrent) + # end recurrent check + + # begin breadth-first search + non_tree_edge_values: set[int] = set() + visited = {class_[0]} + newly_visited = {class_[0]} + level = {class_[0]: 0} + current_level = 0 + done = False # imitate a do-while loop + while not done: # runs at most len(class_) times + done = len(visited) == len(class_) + current_level += 1 + + # this loop and the while loop above run a combined len(class_) number of times. + # so this triple nested loop runs through each of the n states once. + for i in newly_visited: + + # the loop below runs len(class_) number of times + # complexity is around about O(n * avg(len(class_))) + newly_visited = {j for j in class_ if T[i, j] != 0} + + new_tree_edges = newly_visited.difference(visited) + for j in new_tree_edges: + level[j] = current_level + + new_non_tree_edges = newly_visited.intersection(visited) + new_non_tree_edge_values = {level[i]-level[j]+1 for j in new_non_tree_edges} + + non_tree_edge_values = non_tree_edge_values.union(new_non_tree_edge_values) + visited = visited.union(new_tree_edges) + + # igcd needs at least 2 arguments + positive_ntev = {val_e for val_e in non_tree_edge_values if val_e > 0} + if len(positive_ntev) == 0: + periods.append(len(class_)) + elif len(positive_ntev) == 1: + periods.append(positive_ntev.pop()) + else: + periods.append(igcd(*positive_ntev)) + # end breadth-first search + + # convert back to the user's state names + classes = [[_sympify(self._state_index[i]) for i in class_] for class_ in classes] + return list(zip(classes, recurrence, map(Integer,periods))) + + def fundamental_matrix(self): + """ + Each entry fundamental matrix can be interpreted as + the expected number of times the chains is in state j + if it started in state i. + + References + ========== + + .. [1] https://lips.cs.princeton.edu/the-fundamental-matrix-of-a-finite-markov-chain/ + + """ + _, _, _, Q = self.decompose() + + if Q.shape[0] > 0: # if non-ergodic + I = eye(Q.shape[0]) + if (I - Q).det() == 0: + raise ValueError("The fundamental matrix doesn't exist.") + return (I - Q).inv().as_immutable() + else: # if ergodic + P = self.transition_probabilities + I = eye(P.shape[0]) + w = self.fixed_row_vector() + W = Matrix([list(w) for i in range(0, P.shape[0])]) + if (I - P + W).det() == 0: + raise ValueError("The fundamental matrix doesn't exist.") + return (I - P + W).inv().as_immutable() + + def absorbing_probabilities(self): + """ + Computes the absorbing probabilities, i.e. + the ij-th entry of the matrix denotes the + probability of Markov chain being absorbed + in state j starting from state i. + """ + _, _, R, _ = self.decompose() + N = self.fundamental_matrix() + if R is None or N is None: + return None + return N*R + + def absorbing_probabilites(self): + sympy_deprecation_warning( + """ + DiscreteMarkovChain.absorbing_probabilites() is deprecated. Use + absorbing_probabilities() instead (note the spelling difference). + """, + deprecated_since_version="1.7", + active_deprecations_target="deprecated-absorbing_probabilites", + ) + return self.absorbing_probabilities() + + def is_regular(self): + tuples = self.communication_classes() + if len(tuples) == 0: + return S.false # not defined for a 0x0 matrix + classes, _, periods = list(zip(*tuples)) + return And(len(classes) == 1, periods[0] == 1) + + def is_ergodic(self): + tuples = self.communication_classes() + if len(tuples) == 0: + return S.false # not defined for a 0x0 matrix + classes, _, _ = list(zip(*tuples)) + return S(len(classes) == 1) + + def is_absorbing_state(self, state): + trans_probs = self.transition_probabilities + if isinstance(trans_probs, ImmutableMatrix) and \ + state < trans_probs.shape[0]: + return S(trans_probs[state, state]) is S.One + + def is_absorbing_chain(self): + states, A, B, C = self.decompose() + r = A.shape[0] + return And(r > 0, A == Identity(r).as_explicit()) + + def stationary_distribution(self, condition_set=False) -> ImmutableMatrix | ConditionSet | Lambda: + r""" + The stationary distribution is any row vector, p, that solves p = pP, + is row stochastic and each element in p must be nonnegative. + That means in matrix form: :math:`(P-I)^T p^T = 0` and + :math:`(1, \dots, 1) p = 1` + where ``P`` is the one-step transition matrix. + + All time-homogeneous Markov Chains with a finite state space + have at least one stationary distribution. In addition, if + a finite time-homogeneous Markov Chain is irreducible, the + stationary distribution is unique. + + Parameters + ========== + + condition_set : bool + If the chain has a symbolic size or transition matrix, + it will return a ``Lambda`` if ``False`` and return a + ``ConditionSet`` if ``True``. + + Examples + ======== + + >>> from sympy.stats import DiscreteMarkovChain + >>> from sympy import Matrix, S + + An irreducible Markov Chain + + >>> T = Matrix([[S(1)/2, S(1)/2, 0], + ... [S(4)/5, S(1)/5, 0], + ... [1, 0, 0]]) + >>> X = DiscreteMarkovChain('X', trans_probs=T) + >>> X.stationary_distribution() + Matrix([[8/13, 5/13, 0]]) + + A reducible Markov Chain + + >>> T = Matrix([[S(1)/2, S(1)/2, 0], + ... [S(4)/5, S(1)/5, 0], + ... [0, 0, 1]]) + >>> X = DiscreteMarkovChain('X', trans_probs=T) + >>> X.stationary_distribution() + Matrix([[8/13 - 8*tau0/13, 5/13 - 5*tau0/13, tau0]]) + + >>> Y = DiscreteMarkovChain('Y') + >>> Y.stationary_distribution() + Lambda((wm, _T), Eq(wm*_T, wm)) + + >>> Y.stationary_distribution(condition_set=True) + ConditionSet(wm, Eq(wm*_T, wm)) + + References + ========== + + .. [1] https://www.probabilitycourse.com/chapter11/11_2_6_stationary_and_limiting_distributions.php + .. [2] https://web.archive.org/web/20210508104430/https://galton.uchicago.edu/~yibi/teaching/stat317/2014/Lectures/Lecture4_6up.pdf + + See Also + ======== + + sympy.stats.DiscreteMarkovChain.limiting_distribution + """ + trans_probs = self.transition_probabilities + n = self.number_of_states + + if n == 0: + return ImmutableMatrix(Matrix([[]])) + + # symbolic matrix version + if isinstance(trans_probs, MatrixSymbol): + wm = MatrixSymbol('wm', 1, n) + if condition_set: + return ConditionSet(wm, Eq(wm * trans_probs, wm)) + else: + return Lambda((wm, trans_probs), Eq(wm * trans_probs, wm)) + + # numeric matrix version + a = Matrix(trans_probs - Identity(n)).T + a[0, 0:n] = ones(1, n) # type: ignore + b = zeros(n, 1) + b[0, 0] = 1 + + soln = list(linsolve((a, b)))[0] + return ImmutableMatrix([soln]) + + def fixed_row_vector(self): + """ + A wrapper for ``stationary_distribution()``. + """ + return self.stationary_distribution() + + @property + def limiting_distribution(self): + """ + The fixed row vector is the limiting + distribution of a discrete Markov chain. + """ + return self.fixed_row_vector() + + def decompose(self) -> tuple[list[Basic], ImmutableMatrix, ImmutableMatrix, ImmutableMatrix]: + """ + Decomposes the transition matrix into submatrices with + special properties. + + The transition matrix can be decomposed into 4 submatrices: + - A - the submatrix from recurrent states to recurrent states. + - B - the submatrix from transient to recurrent states. + - C - the submatrix from transient to transient states. + - O - the submatrix of zeros for recurrent to transient states. + + Returns + ======= + + states, A, B, C + ``states`` - a list of state names with the first being + the recurrent states and the last being + the transient states in the order + of the row names of A and then the row names of C. + ``A`` - the submatrix from recurrent states to recurrent states. + ``B`` - the submatrix from transient to recurrent states. + ``C`` - the submatrix from transient to transient states. + + Examples + ======== + + >>> from sympy.stats import DiscreteMarkovChain + >>> from sympy import Matrix, S + + One can decompose this chain for example: + + >>> T = Matrix([[S(1)/2, S(1)/2, 0, 0, 0], + ... [S(2)/5, S(1)/5, S(2)/5, 0, 0], + ... [0, 0, 1, 0, 0], + ... [0, 0, S(1)/2, S(1)/2, 0], + ... [S(1)/2, 0, 0, 0, S(1)/2]]) + >>> X = DiscreteMarkovChain('X', trans_probs=T) + >>> states, A, B, C = X.decompose() + >>> states + [2, 0, 1, 3, 4] + + >>> A # recurrent to recurrent + Matrix([[1]]) + + >>> B # transient to recurrent + Matrix([ + [ 0], + [2/5], + [1/2], + [ 0]]) + + >>> C # transient to transient + Matrix([ + [1/2, 1/2, 0, 0], + [2/5, 1/5, 0, 0], + [ 0, 0, 1/2, 0], + [1/2, 0, 0, 1/2]]) + + This means that state 2 is the only absorbing state + (since A is a 1x1 matrix). B is a 4x1 matrix since + the 4 remaining transient states all merge into recurrent + state 2. And C is the 4x4 matrix that shows how the + transient states 0, 1, 3, 4 all interact. + + See Also + ======== + + sympy.stats.DiscreteMarkovChain.communication_classes + sympy.stats.DiscreteMarkovChain.canonical_form + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Absorbing_Markov_chain + .. [2] https://people.brandeis.edu/~igusa/Math56aS08/Math56a_S08_notes015.pdf + """ + trans_probs = self.transition_probabilities + + classes = self.communication_classes() + r_states = [] + t_states = [] + + for states, recurrent, period in classes: + if recurrent: + r_states += states + else: + t_states += states + + states = r_states + t_states + indexes = [self.index_of[state] for state in states] # type: ignore + + A = Matrix(len(r_states), len(r_states), + lambda i, j: trans_probs[indexes[i], indexes[j]]) + + B = Matrix(len(t_states), len(r_states), + lambda i, j: trans_probs[indexes[len(r_states) + i], indexes[j]]) + + C = Matrix(len(t_states), len(t_states), + lambda i, j: trans_probs[indexes[len(r_states) + i], indexes[len(r_states) + j]]) + + return states, A.as_immutable(), B.as_immutable(), C.as_immutable() + + def canonical_form(self) -> tuple[list[Basic], ImmutableMatrix]: + """ + Reorders the one-step transition matrix + so that recurrent states appear first and transient + states appear last. Other representations include inserting + transient states first and recurrent states last. + + Returns + ======= + + states, P_new + ``states`` is the list that describes the order of the + new states in the matrix + so that the ith element in ``states`` is the state of the + ith row of A. + ``P_new`` is the new transition matrix in canonical form. + + Examples + ======== + + >>> from sympy.stats import DiscreteMarkovChain + >>> from sympy import Matrix, S + + You can convert your chain into canonical form: + + >>> T = Matrix([[S(1)/2, S(1)/2, 0, 0, 0], + ... [S(2)/5, S(1)/5, S(2)/5, 0, 0], + ... [0, 0, 1, 0, 0], + ... [0, 0, S(1)/2, S(1)/2, 0], + ... [S(1)/2, 0, 0, 0, S(1)/2]]) + >>> X = DiscreteMarkovChain('X', list(range(1, 6)), trans_probs=T) + >>> states, new_matrix = X.canonical_form() + >>> states + [3, 1, 2, 4, 5] + + >>> new_matrix + Matrix([ + [ 1, 0, 0, 0, 0], + [ 0, 1/2, 1/2, 0, 0], + [2/5, 2/5, 1/5, 0, 0], + [1/2, 0, 0, 1/2, 0], + [ 0, 1/2, 0, 0, 1/2]]) + + The new states are [3, 1, 2, 4, 5] and you can + create a new chain with this and its canonical + form will remain the same (since it is already + in canonical form). + + >>> X = DiscreteMarkovChain('X', states, new_matrix) + >>> states, new_matrix = X.canonical_form() + >>> states + [3, 1, 2, 4, 5] + + >>> new_matrix + Matrix([ + [ 1, 0, 0, 0, 0], + [ 0, 1/2, 1/2, 0, 0], + [2/5, 2/5, 1/5, 0, 0], + [1/2, 0, 0, 1/2, 0], + [ 0, 1/2, 0, 0, 1/2]]) + + This is not limited to absorbing chains: + + >>> T = Matrix([[0, 5, 5, 0, 0], + ... [0, 0, 0, 10, 0], + ... [5, 0, 5, 0, 0], + ... [0, 10, 0, 0, 0], + ... [0, 3, 0, 3, 4]])/10 + >>> X = DiscreteMarkovChain('X', trans_probs=T) + >>> states, new_matrix = X.canonical_form() + >>> states + [1, 3, 0, 2, 4] + + >>> new_matrix + Matrix([ + [ 0, 1, 0, 0, 0], + [ 1, 0, 0, 0, 0], + [ 1/2, 0, 0, 1/2, 0], + [ 0, 0, 1/2, 1/2, 0], + [3/10, 3/10, 0, 0, 2/5]]) + + See Also + ======== + + sympy.stats.DiscreteMarkovChain.communication_classes + sympy.stats.DiscreteMarkovChain.decompose + + References + ========== + + .. [1] https://onlinelibrary.wiley.com/doi/pdf/10.1002/9780470316887.app1 + .. [2] http://www.columbia.edu/~ww2040/6711F12/lect1023big.pdf + """ + states, A, B, C = self.decompose() + O = zeros(A.shape[0], C.shape[1]) + return states, BlockMatrix([[A, O], [B, C]]).as_explicit() + + def sample(self): + """ + Returns + ======= + + sample: iterator object + iterator object containing the sample + + """ + if not isinstance(self.transition_probabilities, (Matrix, ImmutableMatrix)): + raise ValueError("Transition Matrix must be provided for sampling") + Tlist = self.transition_probabilities.tolist() + samps = [random.choice(list(self.state_space))] + yield samps[0] + time = 1 + densities = {} + for state in self.state_space: + states = list(self.state_space) + densities[state] = {states[i]: Tlist[state][i] + for i in range(len(states))} + while time < S.Infinity: + samps.append((next(sample_iter(FiniteRV("_", densities[samps[time - 1]]))))) + yield samps[time] + time += 1 + +class ContinuousMarkovChain(ContinuousTimeStochasticProcess, MarkovProcess): + """ + Represents continuous time Markov chain. + + Parameters + ========== + + sym : Symbol/str + state_space : Set + Optional, by default, S.Reals + gen_mat : Matrix/ImmutableMatrix/MatrixSymbol + Optional, by default, None + + Examples + ======== + + >>> from sympy.stats import ContinuousMarkovChain, P + >>> from sympy import Matrix, S, Eq, Gt + >>> G = Matrix([[-S(1), S(1)], [S(1), -S(1)]]) + >>> C = ContinuousMarkovChain('C', state_space=[0, 1], gen_mat=G) + >>> C.limiting_distribution() + Matrix([[1/2, 1/2]]) + >>> C.state_space + {0, 1} + >>> C.generator_matrix + Matrix([ + [-1, 1], + [ 1, -1]]) + + Probability queries are supported + + >>> P(Eq(C(1.96), 0), Eq(C(0.78), 1)).round(5) + 0.45279 + >>> P(Gt(C(1.7), 0), Eq(C(0.82), 1)).round(5) + 0.58602 + + Probability of expressions with multiple RandomIndexedSymbols + can also be calculated provided there is only 1 RandomIndexedSymbol + in the given condition. It is always better to use Rational instead + of floating point numbers for the probabilities in the + generator matrix to avoid errors. + + >>> from sympy import Gt, Le, Rational + >>> G = Matrix([[-S(1), Rational(1, 10), Rational(9, 10)], [Rational(2, 5), -S(1), Rational(3, 5)], [Rational(1, 2), Rational(1, 2), -S(1)]]) + >>> C = ContinuousMarkovChain('C', state_space=[0, 1, 2], gen_mat=G) + >>> P(Eq(C(3.92), C(1.75)), Eq(C(0.46), 0)).round(5) + 0.37933 + >>> P(Gt(C(3.92), C(1.75)), Eq(C(0.46), 0)).round(5) + 0.34211 + >>> P(Le(C(1.57), C(3.14)), Eq(C(1.22), 1)).round(4) + 0.7143 + + Symbolic probability queries are also supported + + >>> from sympy import symbols + >>> a,b,c,d = symbols('a b c d') + >>> G = Matrix([[-S(1), Rational(1, 10), Rational(9, 10)], [Rational(2, 5), -S(1), Rational(3, 5)], [Rational(1, 2), Rational(1, 2), -S(1)]]) + >>> C = ContinuousMarkovChain('C', state_space=[0, 1, 2], gen_mat=G) + >>> query = P(Eq(C(a), b), Eq(C(c), d)) + >>> query.subs({a:3.65, b:2, c:1.78, d:1}).evalf().round(10) + 0.4002723175 + >>> P(Eq(C(3.65), 2), Eq(C(1.78), 1)).round(10) + 0.4002723175 + >>> query_gt = P(Gt(C(a), b), Eq(C(c), d)) + >>> query_gt.subs({a:43.2, b:0, c:3.29, d:2}).evalf().round(10) + 0.6832579186 + >>> P(Gt(C(43.2), 0), Eq(C(3.29), 2)).round(10) + 0.6832579186 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Markov_chain#Continuous-time_Markov_chain + .. [2] https://u.math.biu.ac.il/~amirgi/CTMCnotes.pdf + """ + index_set = S.Reals + + def __new__(cls, sym, state_space=None, gen_mat=None): + sym = _symbol_converter(sym) + state_space, gen_mat = MarkovProcess._sanity_checks(state_space, gen_mat) + obj = Basic.__new__(cls, sym, state_space, gen_mat) + indices = {} + if isinstance(obj.number_of_states, Integer): + for index, state in enumerate(obj.state_space): + indices[state] = index + obj.index_of = indices + return obj + + @property + def generator_matrix(self): + return self.args[2] + + @cacheit + def transition_probabilities(self, gen_mat=None): + t = Dummy('t') + if isinstance(gen_mat, (Matrix, ImmutableMatrix)) and \ + gen_mat.is_diagonalizable(): + # for faster computation use diagonalized generator matrix + Q, D = gen_mat.diagonalize() + return Lambda(t, Q*exp(t*D)*Q.inv()) + if gen_mat != None: + return Lambda(t, exp(t*gen_mat)) + + def limiting_distribution(self): + gen_mat = self.generator_matrix + if gen_mat is None: + return None + if isinstance(gen_mat, MatrixSymbol): + wm = MatrixSymbol('wm', 1, gen_mat.shape[0]) + return Lambda((wm, gen_mat), Eq(wm*gen_mat, wm)) + w = IndexedBase('w') + wi = [w[i] for i in range(gen_mat.shape[0])] + wm = Matrix([wi]) + eqs = (wm*gen_mat).tolist()[0] + eqs.append(sum(wi) - 1) + soln = list(linsolve(eqs, wi))[0] + return ImmutableMatrix([soln]) + + +class BernoulliProcess(DiscreteTimeStochasticProcess): + """ + The Bernoulli process consists of repeated + independent Bernoulli process trials with the same parameter `p`. + It's assumed that the probability `p` applies to every + trial and that the outcomes of each trial + are independent of all the rest. Therefore Bernoulli Process + is Discrete State and Discrete Time Stochastic Process. + + Parameters + ========== + + sym : Symbol/str + success : Integer/str + The event which is considered to be success. Default: 1. + failure: Integer/str + The event which is considered to be failure. Default: 0. + p : Real Number between 0 and 1 + Represents the probability of getting success. + + Examples + ======== + + >>> from sympy.stats import BernoulliProcess, P, E + >>> from sympy import Eq, Gt + >>> B = BernoulliProcess("B", p=0.7, success=1, failure=0) + >>> B.state_space + {0, 1} + >>> B.p.round(2) + 0.70 + >>> B.success + 1 + >>> B.failure + 0 + >>> X = B[1] + B[2] + B[3] + >>> P(Eq(X, 0)).round(2) + 0.03 + >>> P(Eq(X, 2)).round(2) + 0.44 + >>> P(Eq(X, 4)).round(2) + 0 + >>> P(Gt(X, 1)).round(2) + 0.78 + >>> P(Eq(B[1], 0) & Eq(B[2], 1) & Eq(B[3], 0) & Eq(B[4], 1)).round(2) + 0.04 + >>> B.joint_distribution(B[1], B[2]) + JointDistributionHandmade(Lambda((B[1], B[2]), Piecewise((0.7, Eq(B[1], 1)), + (0.3, Eq(B[1], 0)), (0, True))*Piecewise((0.7, Eq(B[2], 1)), (0.3, Eq(B[2], 0)), + (0, True)))) + >>> E(2*B[1] + B[2]).round(2) + 2.10 + >>> P(B[1] < 1).round(2) + 0.30 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Bernoulli_process + .. [2] https://mathcs.clarku.edu/~djoyce/ma217/bernoulli.pdf + + """ + + index_set = S.Naturals0 + + def __new__(cls, sym, p, success=1, failure=0): + _value_check(p >= 0 and p <= 1, 'Value of p must be between 0 and 1.') + sym = _symbol_converter(sym) + p = _sympify(p) + success = _sym_sympify(success) + failure = _sym_sympify(failure) + return Basic.__new__(cls, sym, p, success, failure) + + @property + def symbol(self): + return self.args[0] + + @property + def p(self): + return self.args[1] + + @property + def success(self): + return self.args[2] + + @property + def failure(self): + return self.args[3] + + @property + def state_space(self): + return _set_converter([self.success, self.failure]) + + def distribution(self, key=None): + if key is None: + self._deprecation_warn_distribution() + return BernoulliDistribution(self.p) + return BernoulliDistribution(self.p, self.success, self.failure) + + def simple_rv(self, rv): + return Bernoulli(rv.name, p=self.p, + succ=self.success, fail=self.failure) + + def expectation(self, expr, condition=None, evaluate=True, **kwargs): + """ + Computes expectation. + + Parameters + ========== + + expr : RandomIndexedSymbol, Relational, Logic + Condition for which expectation has to be computed. Must + contain a RandomIndexedSymbol of the process. + condition : Relational, Logic + The given conditions under which computations should be done. + + Returns + ======= + + Expectation of the RandomIndexedSymbol. + + """ + + return _SubstituteRV._expectation(expr, condition, evaluate, **kwargs) + + def probability(self, condition, given_condition=None, evaluate=True, **kwargs): + """ + Computes probability. + + Parameters + ========== + + condition : Relational + Condition for which probability has to be computed. Must + contain a RandomIndexedSymbol of the process. + given_condition : Relational, Logic + The given conditions under which computations should be done. + + Returns + ======= + + Probability of the condition. + + """ + + return _SubstituteRV._probability(condition, given_condition, evaluate, **kwargs) + + def density(self, x): + return Piecewise((self.p, Eq(x, self.success)), + (1 - self.p, Eq(x, self.failure)), + (S.Zero, True)) + +class _SubstituteRV: + """ + Internal class to handle the queries of expectation and probability + by substitution. + """ + + @staticmethod + def _rvindexed_subs(expr, condition=None): + """ + Substitutes the RandomIndexedSymbol with the RandomSymbol with + same name, distribution and probability as RandomIndexedSymbol. + + Parameters + ========== + + expr: RandomIndexedSymbol, Relational, Logic + Condition for which expectation has to be computed. Must + contain a RandomIndexedSymbol of the process. + condition: Relational, Logic + The given conditions under which computations should be done. + + """ + + rvs_expr = random_symbols(expr) + if len(rvs_expr) != 0: + swapdict_expr = {} + for rv in rvs_expr: + if isinstance(rv, RandomIndexedSymbol): + newrv = rv.pspace.process.simple_rv(rv) # substitute with equivalent simple rv + swapdict_expr[rv] = newrv + expr = expr.subs(swapdict_expr) + rvs_cond = random_symbols(condition) + if len(rvs_cond)!=0: + swapdict_cond = {} + for rv in rvs_cond: + if isinstance(rv, RandomIndexedSymbol): + newrv = rv.pspace.process.simple_rv(rv) + swapdict_cond[rv] = newrv + condition = condition.subs(swapdict_cond) + return expr, condition + + @classmethod + def _expectation(self, expr, condition=None, evaluate=True, **kwargs): + """ + Internal method for computing expectation of indexed RV. + + Parameters + ========== + + expr: RandomIndexedSymbol, Relational, Logic + Condition for which expectation has to be computed. Must + contain a RandomIndexedSymbol of the process. + condition: Relational, Logic + The given conditions under which computations should be done. + + Returns + ======= + + Expectation of the RandomIndexedSymbol. + + """ + new_expr, new_condition = self._rvindexed_subs(expr, condition) + + if not is_random(new_expr): + return new_expr + new_pspace = pspace(new_expr) + if new_condition is not None: + new_expr = given(new_expr, new_condition) + if new_expr.is_Add: # As E is Linear + return Add(*[new_pspace.compute_expectation( + expr=arg, evaluate=evaluate, **kwargs) + for arg in new_expr.args]) + return new_pspace.compute_expectation( + new_expr, evaluate=evaluate, **kwargs) + + @classmethod + def _probability(self, condition, given_condition=None, evaluate=True, **kwargs): + """ + Internal method for computing probability of indexed RV + + Parameters + ========== + + condition: Relational + Condition for which probability has to be computed. Must + contain a RandomIndexedSymbol of the process. + given_condition: Relational/And + The given conditions under which computations should be done. + + Returns + ======= + + Probability of the condition. + + """ + new_condition, new_givencondition = self._rvindexed_subs(condition, given_condition) + + if isinstance(new_givencondition, RandomSymbol): + condrv = random_symbols(new_condition) + if len(condrv) == 1 and condrv[0] == new_givencondition: + return BernoulliDistribution(self._probability(new_condition), 0, 1) + + if any(dependent(rv, new_givencondition) for rv in condrv): + return Probability(new_condition, new_givencondition) + else: + return self._probability(new_condition) + + if new_givencondition is not None and \ + not isinstance(new_givencondition, (Relational, Boolean)): + raise ValueError("%s is not a relational or combination of relationals" + % (new_givencondition)) + if new_givencondition == False or new_condition == False: + return S.Zero + if new_condition == True: + return S.One + if not isinstance(new_condition, (Relational, Boolean)): + raise ValueError("%s is not a relational or combination of relationals" + % (new_condition)) + + if new_givencondition is not None: # If there is a condition + # Recompute on new conditional expr + return self._probability(given(new_condition, new_givencondition, **kwargs), **kwargs) + result = pspace(new_condition).probability(new_condition, **kwargs) + if evaluate and hasattr(result, 'doit'): + return result.doit() + else: + return result + +def get_timerv_swaps(expr, condition): + """ + Finds the appropriate interval for each time stamp in expr by parsing + the given condition and returns intervals for each timestamp and + dictionary that maps variable time-stamped Random Indexed Symbol to its + corresponding Random Indexed variable with fixed time stamp. + + Parameters + ========== + + expr: SymPy Expression + Expression containing Random Indexed Symbols with variable time stamps + condition: Relational/Boolean Expression + Expression containing time bounds of variable time stamps in expr + + Examples + ======== + + >>> from sympy.stats.stochastic_process_types import get_timerv_swaps, PoissonProcess + >>> from sympy import symbols, Contains, Interval + >>> x, t, d = symbols('x t d', positive=True) + >>> X = PoissonProcess("X", 3) + >>> get_timerv_swaps(x*X(t), Contains(t, Interval.Lopen(0, 1))) + ([Interval.Lopen(0, 1)], {X(t): X(1)}) + >>> get_timerv_swaps((X(t)**2 + X(d)**2), Contains(t, Interval.Lopen(0, 1)) + ... & Contains(d, Interval.Ropen(1, 4))) # doctest: +SKIP + ([Interval.Ropen(1, 4), Interval.Lopen(0, 1)], {X(d): X(3), X(t): X(1)}) + + Returns + ======= + + intervals: list + List of Intervals/FiniteSet on which each time stamp is defined + rv_swap: dict + Dictionary mapping variable time Random Indexed Symbol to constant time + Random Indexed Variable + + """ + + if not isinstance(condition, (Relational, Boolean)): + raise ValueError("%s is not a relational or combination of relationals" + % (condition)) + expr_syms = list(expr.atoms(RandomIndexedSymbol)) + if isinstance(condition, (And, Or)): + given_cond_args = condition.args + else: # single condition + given_cond_args = (condition, ) + rv_swap = {} + intervals = [] + for expr_sym in expr_syms: + for arg in given_cond_args: + if arg.has(expr_sym.key) and isinstance(expr_sym.key, Symbol): + intv = _set_converter(arg.args[1]) + diff_key = intv._sup - intv._inf + if diff_key == oo: + raise ValueError("%s should have finite bounds" % str(expr_sym.name)) + elif diff_key == S.Zero: # has singleton set + diff_key = intv._sup + rv_swap[expr_sym] = expr_sym.subs({expr_sym.key: diff_key}) + intervals.append(intv) + return intervals, rv_swap + + +class CountingProcess(ContinuousTimeStochasticProcess): + """ + This class handles the common methods of the Counting Processes + such as Poisson, Wiener and Gamma Processes + """ + index_set = _set_converter(Interval(0, oo)) + + @property + def symbol(self): + return self.args[0] + + def expectation(self, expr, condition=None, evaluate=True, **kwargs): + """ + Computes expectation + + Parameters + ========== + + expr: RandomIndexedSymbol, Relational, Logic + Condition for which expectation has to be computed. Must + contain a RandomIndexedSymbol of the process. + condition: Relational, Boolean + The given conditions under which computations should be done, i.e, + the intervals on which each variable time stamp in expr is defined + + Returns + ======= + + Expectation of the given expr + + """ + if condition is not None: + intervals, rv_swap = get_timerv_swaps(expr, condition) + # they are independent when they have non-overlapping intervals + if len(intervals) == 1 or all(Intersection(*intv_comb) == EmptySet + for intv_comb in itertools.combinations(intervals, 2)): + if expr.is_Add: + return Add.fromiter(self.expectation(arg, condition) + for arg in expr.args) + expr = expr.subs(rv_swap) + else: + return Expectation(expr, condition) + + return _SubstituteRV._expectation(expr, evaluate=evaluate, **kwargs) + + def _solve_argwith_tworvs(self, arg): + if arg.args[0].key >= arg.args[1].key or isinstance(arg, Eq): + diff_key = abs(arg.args[0].key - arg.args[1].key) + rv = arg.args[0] + arg = arg.__class__(rv.pspace.process(diff_key), 0) + else: + diff_key = arg.args[1].key - arg.args[0].key + rv = arg.args[1] + arg = arg.__class__(rv.pspace.process(diff_key), 0) + return arg + + def _solve_numerical(self, condition, given_condition=None): + if isinstance(condition, And): + args_list = list(condition.args) + else: + args_list = [condition] + if given_condition is not None: + if isinstance(given_condition, And): + args_list.extend(list(given_condition.args)) + else: + args_list.extend([given_condition]) + # sort the args based on timestamp to get the independent increments in + # each segment using all the condition args as well as given_condition args + args_list = sorted(args_list, key=lambda x: x.args[0].key) + result = [] + cond_args = list(condition.args) if isinstance(condition, And) else [condition] + if args_list[0] in cond_args and not (is_random(args_list[0].args[0]) + and is_random(args_list[0].args[1])): + result.append(_SubstituteRV._probability(args_list[0])) + + if is_random(args_list[0].args[0]) and is_random(args_list[0].args[1]): + arg = self._solve_argwith_tworvs(args_list[0]) + result.append(_SubstituteRV._probability(arg)) + + for i in range(len(args_list) - 1): + curr, nex = args_list[i], args_list[i + 1] + diff_key = nex.args[0].key - curr.args[0].key + working_set = curr.args[0].pspace.process.state_space + if curr.args[1] > nex.args[1]: #impossible condition so return 0 + result.append(0) + break + if isinstance(curr, Eq): + working_set = Intersection(working_set, Interval.Lopen(curr.args[1], oo)) + else: + working_set = Intersection(working_set, curr.as_set()) + if isinstance(nex, Eq): + working_set = Intersection(working_set, Interval(-oo, nex.args[1])) + else: + working_set = Intersection(working_set, nex.as_set()) + if working_set == EmptySet: + rv = Eq(curr.args[0].pspace.process(diff_key), 0) + result.append(_SubstituteRV._probability(rv)) + else: + if working_set.is_finite_set: + if isinstance(curr, Eq) and isinstance(nex, Eq): + rv = Eq(curr.args[0].pspace.process(diff_key), len(working_set)) + result.append(_SubstituteRV._probability(rv)) + elif isinstance(curr, Eq) ^ isinstance(nex, Eq): + result.append(Add.fromiter(_SubstituteRV._probability(Eq( + curr.args[0].pspace.process(diff_key), x)) + for x in range(len(working_set)))) + else: + n = len(working_set) + result.append(Add.fromiter((n - x)*_SubstituteRV._probability(Eq( + curr.args[0].pspace.process(diff_key), x)) for x in range(n))) + else: + result.append(_SubstituteRV._probability( + curr.args[0].pspace.process(diff_key) <= working_set._sup - working_set._inf)) + return Mul.fromiter(result) + + + def probability(self, condition, given_condition=None, evaluate=True, **kwargs): + """ + Computes probability. + + Parameters + ========== + + condition: Relational + Condition for which probability has to be computed. Must + contain a RandomIndexedSymbol of the process. + given_condition: Relational, Boolean + The given conditions under which computations should be done, i.e, + the intervals on which each variable time stamp in expr is defined + + Returns + ======= + + Probability of the condition + + """ + check_numeric = True + if isinstance(condition, (And, Or)): + cond_args = condition.args + else: + cond_args = (condition, ) + # check that condition args are numeric or not + if not all(arg.args[0].key.is_number for arg in cond_args): + check_numeric = False + if given_condition is not None: + check_given_numeric = True + if isinstance(given_condition, (And, Or)): + given_cond_args = given_condition.args + else: + given_cond_args = (given_condition, ) + # check that given condition args are numeric or not + if given_condition.has(Contains): + check_given_numeric = False + # Handle numerical queries + if check_numeric and check_given_numeric: + res = [] + if isinstance(condition, Or): + res.append(Add.fromiter(self._solve_numerical(arg, given_condition) + for arg in condition.args)) + if isinstance(given_condition, Or): + res.append(Add.fromiter(self._solve_numerical(condition, arg) + for arg in given_condition.args)) + if res: + return Add.fromiter(res) + return self._solve_numerical(condition, given_condition) + + # No numeric queries, go by Contains?... then check that all the + # given condition are in form of `Contains` + if not all(arg.has(Contains) for arg in given_cond_args): + raise ValueError("If given condition is passed with `Contains`, then " + "please pass the evaluated condition with its corresponding information " + "in terms of intervals of each time stamp to be passed in given condition.") + + intervals, rv_swap = get_timerv_swaps(condition, given_condition) + # they are independent when they have non-overlapping intervals + if len(intervals) == 1 or all(Intersection(*intv_comb) == EmptySet + for intv_comb in itertools.combinations(intervals, 2)): + if isinstance(condition, And): + return Mul.fromiter(self.probability(arg, given_condition) + for arg in condition.args) + elif isinstance(condition, Or): + return Add.fromiter(self.probability(arg, given_condition) + for arg in condition.args) + condition = condition.subs(rv_swap) + else: + return Probability(condition, given_condition) + if check_numeric: + return self._solve_numerical(condition) + return _SubstituteRV._probability(condition, evaluate=evaluate, **kwargs) + +class PoissonProcess(CountingProcess): + """ + The Poisson process is a counting process. It is usually used in scenarios + where we are counting the occurrences of certain events that appear + to happen at a certain rate, but completely at random. + + Parameters + ========== + + sym : Symbol/str + lamda : Positive number + Rate of the process, ``lambda > 0`` + + Examples + ======== + + >>> from sympy.stats import PoissonProcess, P, E + >>> from sympy import symbols, Eq, Ne, Contains, Interval + >>> X = PoissonProcess("X", lamda=3) + >>> X.state_space + Naturals0 + >>> X.lamda + 3 + >>> t1, t2 = symbols('t1 t2', positive=True) + >>> P(X(t1) < 4) + (9*t1**3/2 + 9*t1**2/2 + 3*t1 + 1)*exp(-3*t1) + >>> P(Eq(X(t1), 2) | Ne(X(t1), 4), Contains(t1, Interval.Ropen(2, 4))) + 1 - 36*exp(-6) + >>> P(Eq(X(t1), 2) & Eq(X(t2), 3), Contains(t1, Interval.Lopen(0, 2)) + ... & Contains(t2, Interval.Lopen(2, 4))) + 648*exp(-12) + >>> E(X(t1)) + 3*t1 + >>> E(X(t1)**2 + 2*X(t2), Contains(t1, Interval.Lopen(0, 1)) + ... & Contains(t2, Interval.Lopen(1, 2))) + 18 + >>> P(X(3) < 1, Eq(X(1), 0)) + exp(-6) + >>> P(Eq(X(4), 3), Eq(X(2), 3)) + exp(-6) + >>> P(X(2) <= 3, X(1) > 1) + 5*exp(-3) + + Merging two Poisson Processes + + >>> Y = PoissonProcess("Y", lamda=4) + >>> Z = X + Y + >>> Z.lamda + 7 + + Splitting a Poisson Process into two independent Poisson Processes + + >>> N, M = Z.split(l1=2, l2=5) + >>> N.lamda, M.lamda + (2, 5) + + References + ========== + + .. [1] https://www.probabilitycourse.com/chapter11/11_0_0_intro.php + .. [2] https://en.wikipedia.org/wiki/Poisson_point_process + + """ + + def __new__(cls, sym, lamda): + _value_check(lamda > 0, 'lamda should be a positive number.') + sym = _symbol_converter(sym) + lamda = _sympify(lamda) + return Basic.__new__(cls, sym, lamda) + + @property + def lamda(self): + return self.args[1] + + @property + def state_space(self): + return S.Naturals0 + + def distribution(self, key): + if isinstance(key, RandomIndexedSymbol): + self._deprecation_warn_distribution() + return PoissonDistribution(self.lamda*key.key) + return PoissonDistribution(self.lamda*key) + + def density(self, x): + return (self.lamda*x.key)**x / factorial(x) * exp(-(self.lamda*x.key)) + + def simple_rv(self, rv): + return Poisson(rv.name, lamda=self.lamda*rv.key) + + def __add__(self, other): + if not isinstance(other, PoissonProcess): + raise ValueError("Only instances of Poisson Process can be merged") + return PoissonProcess(Dummy(self.symbol.name + other.symbol.name), + self.lamda + other.lamda) + + def split(self, l1, l2): + if _sympify(l1 + l2) != self.lamda: + raise ValueError("Sum of l1 and l2 should be %s" % str(self.lamda)) + return PoissonProcess(Dummy("l1"), l1), PoissonProcess(Dummy("l2"), l2) + +class WienerProcess(CountingProcess): + """ + The Wiener process is a real valued continuous-time stochastic process. + In physics it is used to study Brownian motion and it is often also called + Brownian motion due to its historical connection with physical process of the + same name originally observed by Scottish botanist Robert Brown. + + Parameters + ========== + + sym : Symbol/str + + Examples + ======== + + >>> from sympy.stats import WienerProcess, P, E + >>> from sympy import symbols, Contains, Interval + >>> X = WienerProcess("X") + >>> X.state_space + Reals + >>> t1, t2 = symbols('t1 t2', positive=True) + >>> P(X(t1) < 7).simplify() + erf(7*sqrt(2)/(2*sqrt(t1)))/2 + 1/2 + >>> P((X(t1) > 2) | (X(t1) < 4), Contains(t1, Interval.Ropen(2, 4))).simplify() + -erf(1)/2 + erf(2)/2 + 1 + >>> E(X(t1)) + 0 + >>> E(X(t1) + 2*X(t2), Contains(t1, Interval.Lopen(0, 1)) + ... & Contains(t2, Interval.Lopen(1, 2))) + 0 + + References + ========== + + .. [1] https://www.probabilitycourse.com/chapter11/11_4_0_brownian_motion_wiener_process.php + .. [2] https://en.wikipedia.org/wiki/Wiener_process + + """ + def __new__(cls, sym): + sym = _symbol_converter(sym) + return Basic.__new__(cls, sym) + + @property + def state_space(self): + return S.Reals + + def distribution(self, key): + if isinstance(key, RandomIndexedSymbol): + self._deprecation_warn_distribution() + return NormalDistribution(0, sqrt(key.key)) + return NormalDistribution(0, sqrt(key)) + + def density(self, x): + return exp(-x**2/(2*x.key)) / (sqrt(2*pi)*sqrt(x.key)) + + def simple_rv(self, rv): + return Normal(rv.name, 0, sqrt(rv.key)) + + +class GammaProcess(CountingProcess): + r""" + A Gamma process is a random process with independent gamma distributed + increments. It is a pure-jump increasing Levy process. + + Parameters + ========== + + sym : Symbol/str + lamda : Positive number + Jump size of the process, ``lamda > 0`` + gamma : Positive number + Rate of jump arrivals, `\gamma > 0` + + Examples + ======== + + >>> from sympy.stats import GammaProcess, E, P, variance + >>> from sympy import symbols, Contains, Interval, Not + >>> t, d, x, l, g = symbols('t d x l g', positive=True) + >>> X = GammaProcess("X", l, g) + >>> E(X(t)) + g*t/l + >>> variance(X(t)).simplify() + g*t/l**2 + >>> X = GammaProcess('X', 1, 2) + >>> P(X(t) < 1).simplify() + lowergamma(2*t, 1)/gamma(2*t) + >>> P(Not((X(t) < 5) & (X(d) > 3)), Contains(t, Interval.Ropen(2, 4)) & + ... Contains(d, Interval.Lopen(7, 8))).simplify() + -4*exp(-3) + 472*exp(-8)/3 + 1 + >>> E(X(2) + x*E(X(5))) + 10*x + 4 + + References + ========== + + .. [1] https://en.wikipedia.org/wiki/Gamma_process + + """ + def __new__(cls, sym, lamda, gamma): + _value_check(lamda > 0, 'lamda should be a positive number') + _value_check(gamma > 0, 'gamma should be a positive number') + sym = _symbol_converter(sym) + gamma = _sympify(gamma) + lamda = _sympify(lamda) + return Basic.__new__(cls, sym, lamda, gamma) + + @property + def lamda(self): + return self.args[1] + + @property + def gamma(self): + return self.args[2] + + @property + def state_space(self): + return _set_converter(Interval(0, oo)) + + def distribution(self, key): + if isinstance(key, RandomIndexedSymbol): + self._deprecation_warn_distribution() + return GammaDistribution(self.gamma*key.key, 1/self.lamda) + return GammaDistribution(self.gamma*key, 1/self.lamda) + + def density(self, x): + k = self.gamma*x.key + theta = 1/self.lamda + return x**(k - 1) * exp(-x/theta) / (gamma(k)*theta**k) + + def simple_rv(self, rv): + return Gamma(rv.name, self.gamma*rv.key, 1/self.lamda) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/symbolic_multivariate_probability.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/symbolic_multivariate_probability.py new file mode 100644 index 0000000000000000000000000000000000000000..bbe8776e58e82489e29734cea48c9138bc512f34 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/symbolic_multivariate_probability.py @@ -0,0 +1,308 @@ +import itertools + +from sympy.core.add import Add +from sympy.core.expr import Expr +from sympy.core.function import expand as _expand +from sympy.core.mul import Mul +from sympy.core.singleton import S +from sympy.matrices.exceptions import ShapeError +from sympy.matrices.expressions.matexpr import MatrixExpr +from sympy.matrices.expressions.matmul import MatMul +from sympy.matrices.expressions.special import ZeroMatrix +from sympy.stats.rv import RandomSymbol, is_random +from sympy.core.sympify import _sympify +from sympy.stats.symbolic_probability import Variance, Covariance, Expectation + + +class ExpectationMatrix(Expectation, MatrixExpr): + """ + Expectation of a random matrix expression. + + Examples + ======== + + >>> from sympy.stats import ExpectationMatrix, Normal + >>> from sympy.stats.rv import RandomMatrixSymbol + >>> from sympy import symbols, MatrixSymbol, Matrix + >>> k = symbols("k") + >>> A, B = MatrixSymbol("A", k, k), MatrixSymbol("B", k, k) + >>> X, Y = RandomMatrixSymbol("X", k, 1), RandomMatrixSymbol("Y", k, 1) + >>> ExpectationMatrix(X) + ExpectationMatrix(X) + >>> ExpectationMatrix(A*X).shape + (k, 1) + + To expand the expectation in its expression, use ``expand()``: + + >>> ExpectationMatrix(A*X + B*Y).expand() + A*ExpectationMatrix(X) + B*ExpectationMatrix(Y) + >>> ExpectationMatrix((X + Y)*(X - Y).T).expand() + ExpectationMatrix(X*X.T) - ExpectationMatrix(X*Y.T) + ExpectationMatrix(Y*X.T) - ExpectationMatrix(Y*Y.T) + + To evaluate the ``ExpectationMatrix``, use ``doit()``: + + >>> N11, N12 = Normal('N11', 11, 1), Normal('N12', 12, 1) + >>> N21, N22 = Normal('N21', 21, 1), Normal('N22', 22, 1) + >>> M11, M12 = Normal('M11', 1, 1), Normal('M12', 2, 1) + >>> M21, M22 = Normal('M21', 3, 1), Normal('M22', 4, 1) + >>> x1 = Matrix([[N11, N12], [N21, N22]]) + >>> x2 = Matrix([[M11, M12], [M21, M22]]) + >>> ExpectationMatrix(x1 + x2).doit() + Matrix([ + [12, 14], + [24, 26]]) + + """ + def __new__(cls, expr, condition=None): + expr = _sympify(expr) + if condition is None: + if not is_random(expr): + return expr + obj = Expr.__new__(cls, expr) + else: + condition = _sympify(condition) + obj = Expr.__new__(cls, expr, condition) + + obj._shape = expr.shape + obj._condition = condition + return obj + + @property + def shape(self): + return self._shape + + def expand(self, **hints): + expr = self.args[0] + condition = self._condition + if not is_random(expr): + return expr + + if isinstance(expr, Add): + return Add.fromiter(Expectation(a, condition=condition).expand() + for a in expr.args) + + expand_expr = _expand(expr) + if isinstance(expand_expr, Add): + return Add.fromiter(Expectation(a, condition=condition).expand() + for a in expand_expr.args) + + elif isinstance(expr, (Mul, MatMul)): + rv = [] + nonrv = [] + postnon = [] + + for a in expr.args: + if is_random(a): + if rv: + rv.extend(postnon) + else: + nonrv.extend(postnon) + postnon = [] + rv.append(a) + elif a.is_Matrix: + postnon.append(a) + else: + nonrv.append(a) + + # In order to avoid infinite-looping (MatMul may call .doit() again), + # do not rebuild + if len(nonrv) == 0: + return self + return Mul.fromiter(nonrv)*Expectation(Mul.fromiter(rv), + condition=condition)*Mul.fromiter(postnon) + + return self + +class VarianceMatrix(Variance, MatrixExpr): + """ + Variance of a random matrix probability expression. Also known as + Covariance matrix, auto-covariance matrix, dispersion matrix, + or variance-covariance matrix. + + Examples + ======== + + >>> from sympy.stats import VarianceMatrix + >>> from sympy.stats.rv import RandomMatrixSymbol + >>> from sympy import symbols, MatrixSymbol + >>> k = symbols("k") + >>> A, B = MatrixSymbol("A", k, k), MatrixSymbol("B", k, k) + >>> X, Y = RandomMatrixSymbol("X", k, 1), RandomMatrixSymbol("Y", k, 1) + >>> VarianceMatrix(X) + VarianceMatrix(X) + >>> VarianceMatrix(X).shape + (k, k) + + To expand the variance in its expression, use ``expand()``: + + >>> VarianceMatrix(A*X).expand() + A*VarianceMatrix(X)*A.T + >>> VarianceMatrix(A*X + B*Y).expand() + 2*A*CrossCovarianceMatrix(X, Y)*B.T + A*VarianceMatrix(X)*A.T + B*VarianceMatrix(Y)*B.T + """ + def __new__(cls, arg, condition=None): + arg = _sympify(arg) + + if 1 not in arg.shape: + raise ShapeError("Expression is not a vector") + + shape = (arg.shape[0], arg.shape[0]) if arg.shape[1] == 1 else (arg.shape[1], arg.shape[1]) + + if condition: + obj = Expr.__new__(cls, arg, condition) + else: + obj = Expr.__new__(cls, arg) + + obj._shape = shape + obj._condition = condition + return obj + + @property + def shape(self): + return self._shape + + def expand(self, **hints): + arg = self.args[0] + condition = self._condition + + if not is_random(arg): + return ZeroMatrix(*self.shape) + + if isinstance(arg, RandomSymbol): + return self + elif isinstance(arg, Add): + rv = [] + for a in arg.args: + if is_random(a): + rv.append(a) + variances = Add(*(Variance(xv, condition).expand() for xv in rv)) + map_to_covar = lambda x: 2*Covariance(*x, condition=condition).expand() + covariances = Add(*map(map_to_covar, itertools.combinations(rv, 2))) + return variances + covariances + elif isinstance(arg, (Mul, MatMul)): + nonrv = [] + rv = [] + for a in arg.args: + if is_random(a): + rv.append(a) + else: + nonrv.append(a) + if len(rv) == 0: + return ZeroMatrix(*self.shape) + # Avoid possible infinite loops with MatMul: + if len(nonrv) == 0: + return self + # Variance of many multiple matrix products is not implemented: + if len(rv) > 1: + return self + return Mul.fromiter(nonrv)*Variance(Mul.fromiter(rv), + condition)*(Mul.fromiter(nonrv)).transpose() + + # this expression contains a RandomSymbol somehow: + return self + +class CrossCovarianceMatrix(Covariance, MatrixExpr): + """ + Covariance of a random matrix probability expression. + + Examples + ======== + + >>> from sympy.stats import CrossCovarianceMatrix + >>> from sympy.stats.rv import RandomMatrixSymbol + >>> from sympy import symbols, MatrixSymbol + >>> k = symbols("k") + >>> A, B = MatrixSymbol("A", k, k), MatrixSymbol("B", k, k) + >>> C, D = MatrixSymbol("C", k, k), MatrixSymbol("D", k, k) + >>> X, Y = RandomMatrixSymbol("X", k, 1), RandomMatrixSymbol("Y", k, 1) + >>> Z, W = RandomMatrixSymbol("Z", k, 1), RandomMatrixSymbol("W", k, 1) + >>> CrossCovarianceMatrix(X, Y) + CrossCovarianceMatrix(X, Y) + >>> CrossCovarianceMatrix(X, Y).shape + (k, k) + + To expand the covariance in its expression, use ``expand()``: + + >>> CrossCovarianceMatrix(X + Y, Z).expand() + CrossCovarianceMatrix(X, Z) + CrossCovarianceMatrix(Y, Z) + >>> CrossCovarianceMatrix(A*X, Y).expand() + A*CrossCovarianceMatrix(X, Y) + >>> CrossCovarianceMatrix(A*X, B.T*Y).expand() + A*CrossCovarianceMatrix(X, Y)*B + >>> CrossCovarianceMatrix(A*X + B*Y, C.T*Z + D.T*W).expand() + A*CrossCovarianceMatrix(X, W)*D + A*CrossCovarianceMatrix(X, Z)*C + B*CrossCovarianceMatrix(Y, W)*D + B*CrossCovarianceMatrix(Y, Z)*C + + """ + def __new__(cls, arg1, arg2, condition=None): + arg1 = _sympify(arg1) + arg2 = _sympify(arg2) + + if (1 not in arg1.shape) or (1 not in arg2.shape) or (arg1.shape[1] != arg2.shape[1]): + raise ShapeError("Expression is not a vector") + + shape = (arg1.shape[0], arg2.shape[0]) if arg1.shape[1] == 1 and arg2.shape[1] == 1 \ + else (1, 1) + + if condition: + obj = Expr.__new__(cls, arg1, arg2, condition) + else: + obj = Expr.__new__(cls, arg1, arg2) + + obj._shape = shape + obj._condition = condition + return obj + + @property + def shape(self): + return self._shape + + def expand(self, **hints): + arg1 = self.args[0] + arg2 = self.args[1] + condition = self._condition + + if arg1 == arg2: + return VarianceMatrix(arg1, condition).expand() + + if not is_random(arg1) or not is_random(arg2): + return ZeroMatrix(*self.shape) + + if isinstance(arg1, RandomSymbol) and isinstance(arg2, RandomSymbol): + return CrossCovarianceMatrix(arg1, arg2, condition) + + coeff_rv_list1 = self._expand_single_argument(arg1.expand()) + coeff_rv_list2 = self._expand_single_argument(arg2.expand()) + + addends = [a*CrossCovarianceMatrix(r1, r2, condition=condition)*b.transpose() + for (a, r1) in coeff_rv_list1 for (b, r2) in coeff_rv_list2] + return Add.fromiter(addends) + + @classmethod + def _expand_single_argument(cls, expr): + # return (coefficient, random_symbol) pairs: + if isinstance(expr, RandomSymbol): + return [(S.One, expr)] + elif isinstance(expr, Add): + outval = [] + for a in expr.args: + if isinstance(a, (Mul, MatMul)): + outval.append(cls._get_mul_nonrv_rv_tuple(a)) + elif is_random(a): + outval.append((S.One, a)) + + return outval + elif isinstance(expr, (Mul, MatMul)): + return [cls._get_mul_nonrv_rv_tuple(expr)] + elif is_random(expr): + return [(S.One, expr)] + + @classmethod + def _get_mul_nonrv_rv_tuple(cls, m): + rv = [] + nonrv = [] + for a in m.args: + if is_random(a): + rv.append(a) + else: + nonrv.append(a) + return (Mul.fromiter(nonrv), Mul.fromiter(rv)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/symbolic_probability.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/symbolic_probability.py new file mode 100644 index 0000000000000000000000000000000000000000..5d0b971a8691f82de15258d4c460129059eaf436 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/symbolic_probability.py @@ -0,0 +1,698 @@ +import itertools +from sympy.concrete.summations import Sum +from sympy.core.add import Add +from sympy.core.expr import Expr +from sympy.core.function import expand as _expand +from sympy.core.mul import Mul +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import Symbol +from sympy.integrals.integrals import Integral +from sympy.logic.boolalg import Not +from sympy.core.parameters import global_parameters +from sympy.core.sorting import default_sort_key +from sympy.core.sympify import _sympify +from sympy.core.relational import Relational +from sympy.logic.boolalg import Boolean +from sympy.stats import variance, covariance +from sympy.stats.rv import (RandomSymbol, pspace, dependent, + given, sampling_E, RandomIndexedSymbol, is_random, + PSpace, sampling_P, random_symbols) + +__all__ = ['Probability', 'Expectation', 'Variance', 'Covariance'] + + +@is_random.register(Expr) +def _(x): + atoms = x.free_symbols + if len(atoms) == 1 and next(iter(atoms)) == x: + return False + return any(is_random(i) for i in atoms) + +@is_random.register(RandomSymbol) # type: ignore +def _(x): + return True + + +class Probability(Expr): + """ + Symbolic expression for the probability. + + Examples + ======== + + >>> from sympy.stats import Probability, Normal + >>> from sympy import Integral + >>> X = Normal("X", 0, 1) + >>> prob = Probability(X > 1) + >>> prob + Probability(X > 1) + + Integral representation: + + >>> prob.rewrite(Integral) + Integral(sqrt(2)*exp(-_z**2/2)/(2*sqrt(pi)), (_z, 1, oo)) + + Evaluation of the integral: + + >>> prob.evaluate_integral() + sqrt(2)*(-sqrt(2)*sqrt(pi)*erf(sqrt(2)/2) + sqrt(2)*sqrt(pi))/(4*sqrt(pi)) + """ + + is_commutative = True + + def __new__(cls, prob, condition=None, **kwargs): + prob = _sympify(prob) + if condition is None: + obj = Expr.__new__(cls, prob) + else: + condition = _sympify(condition) + obj = Expr.__new__(cls, prob, condition) + obj._condition = condition + return obj + + def doit(self, **hints): + condition = self.args[0] + given_condition = self._condition + numsamples = hints.get('numsamples', False) + evaluate = hints.get('evaluate', True) + + if isinstance(condition, Not): + return S.One - self.func(condition.args[0], given_condition, + evaluate=evaluate).doit(**hints) + + if condition.has(RandomIndexedSymbol): + return pspace(condition).probability(condition, given_condition, + evaluate=evaluate) + + if isinstance(given_condition, RandomSymbol): + condrv = random_symbols(condition) + if len(condrv) == 1 and condrv[0] == given_condition: + from sympy.stats.frv_types import BernoulliDistribution + return BernoulliDistribution(self.func(condition).doit(**hints), 0, 1) + if any(dependent(rv, given_condition) for rv in condrv): + return Probability(condition, given_condition) + else: + return Probability(condition).doit() + + if given_condition is not None and \ + not isinstance(given_condition, (Relational, Boolean)): + raise ValueError("%s is not a relational or combination of relationals" + % (given_condition)) + + if given_condition == False or condition is S.false: + return S.Zero + if not isinstance(condition, (Relational, Boolean)): + raise ValueError("%s is not a relational or combination of relationals" + % (condition)) + if condition is S.true: + return S.One + + if numsamples: + return sampling_P(condition, given_condition, numsamples=numsamples) + if given_condition is not None: # If there is a condition + # Recompute on new conditional expr + return Probability(given(condition, given_condition)).doit() + + # Otherwise pass work off to the ProbabilitySpace + if pspace(condition) == PSpace(): + return Probability(condition, given_condition) + + result = pspace(condition).probability(condition) + if hasattr(result, 'doit') and evaluate: + return result.doit() + else: + return result + + def _eval_rewrite_as_Integral(self, arg, condition=None, **kwargs): + return self.func(arg, condition=condition).doit(evaluate=False) + + _eval_rewrite_as_Sum = _eval_rewrite_as_Integral + + def evaluate_integral(self): + return self.rewrite(Integral).doit() + + +class Expectation(Expr): + """ + Symbolic expression for the expectation. + + Examples + ======== + + >>> from sympy.stats import Expectation, Normal, Probability, Poisson + >>> from sympy import symbols, Integral, Sum + >>> mu = symbols("mu") + >>> sigma = symbols("sigma", positive=True) + >>> X = Normal("X", mu, sigma) + >>> Expectation(X) + Expectation(X) + >>> Expectation(X).evaluate_integral().simplify() + mu + + To get the integral expression of the expectation: + + >>> Expectation(X).rewrite(Integral) + Integral(sqrt(2)*X*exp(-(X - mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (X, -oo, oo)) + + The same integral expression, in more abstract terms: + + >>> Expectation(X).rewrite(Probability) + Integral(x*Probability(Eq(X, x)), (x, -oo, oo)) + + To get the Summation expression of the expectation for discrete random variables: + + >>> lamda = symbols('lamda', positive=True) + >>> Z = Poisson('Z', lamda) + >>> Expectation(Z).rewrite(Sum) + Sum(Z*lamda**Z*exp(-lamda)/factorial(Z), (Z, 0, oo)) + + This class is aware of some properties of the expectation: + + >>> from sympy.abc import a + >>> Expectation(a*X) + Expectation(a*X) + >>> Y = Normal("Y", 1, 2) + >>> Expectation(X + Y) + Expectation(X + Y) + + To expand the ``Expectation`` into its expression, use ``expand()``: + + >>> Expectation(X + Y).expand() + Expectation(X) + Expectation(Y) + >>> Expectation(a*X + Y).expand() + a*Expectation(X) + Expectation(Y) + >>> Expectation(a*X + Y) + Expectation(a*X + Y) + >>> Expectation((X + Y)*(X - Y)).expand() + Expectation(X**2) - Expectation(Y**2) + + To evaluate the ``Expectation``, use ``doit()``: + + >>> Expectation(X + Y).doit() + mu + 1 + >>> Expectation(X + Expectation(Y + Expectation(2*X))).doit() + 3*mu + 1 + + To prevent evaluating nested ``Expectation``, use ``doit(deep=False)`` + + >>> Expectation(X + Expectation(Y)).doit(deep=False) + mu + Expectation(Expectation(Y)) + >>> Expectation(X + Expectation(Y + Expectation(2*X))).doit(deep=False) + mu + Expectation(Expectation(Expectation(2*X) + Y)) + + """ + + def __new__(cls, expr, condition=None, **kwargs): + expr = _sympify(expr) + if expr.is_Matrix: + from sympy.stats.symbolic_multivariate_probability import ExpectationMatrix + return ExpectationMatrix(expr, condition) + if condition is None: + if not is_random(expr): + return expr + obj = Expr.__new__(cls, expr) + else: + condition = _sympify(condition) + obj = Expr.__new__(cls, expr, condition) + obj._condition = condition + return obj + + def _eval_is_commutative(self): + return(self.args[0].is_commutative) + + def expand(self, **hints): + expr = self.args[0] + condition = self._condition + + if not is_random(expr): + return expr + + if isinstance(expr, Add): + return Add.fromiter(Expectation(a, condition=condition).expand() + for a in expr.args) + + expand_expr = _expand(expr) + if isinstance(expand_expr, Add): + return Add.fromiter(Expectation(a, condition=condition).expand() + for a in expand_expr.args) + + elif isinstance(expr, Mul): + rv = [] + nonrv = [] + for a in expr.args: + if is_random(a): + rv.append(a) + else: + nonrv.append(a) + return Mul.fromiter(nonrv)*Expectation(Mul.fromiter(rv), condition=condition) + + return self + + def doit(self, **hints): + deep = hints.get('deep', True) + condition = self._condition + expr = self.args[0] + numsamples = hints.get('numsamples', False) + evaluate = hints.get('evaluate', True) + + if deep: + expr = expr.doit(**hints) + + if not is_random(expr) or isinstance(expr, Expectation): # expr isn't random? + return expr + if numsamples: # Computing by monte carlo sampling? + evalf = hints.get('evalf', True) + return sampling_E(expr, condition, numsamples=numsamples, evalf=evalf) + + if expr.has(RandomIndexedSymbol): + return pspace(expr).compute_expectation(expr, condition) + + # Create new expr and recompute E + if condition is not None: # If there is a condition + return self.func(given(expr, condition)).doit(**hints) + + # A few known statements for efficiency + + if expr.is_Add: # We know that E is Linear + return Add(*[self.func(arg, condition).doit(**hints) + if not isinstance(arg, Expectation) else self.func(arg, condition) + for arg in expr.args]) + if expr.is_Mul: + if expr.atoms(Expectation): + return expr + + if pspace(expr) == PSpace(): + return self.func(expr) + # Otherwise case is simple, pass work off to the ProbabilitySpace + result = pspace(expr).compute_expectation(expr, evaluate=evaluate) + if hasattr(result, 'doit') and evaluate: + return result.doit(**hints) + else: + return result + + + def _eval_rewrite_as_Probability(self, arg, condition=None, **kwargs): + rvs = arg.atoms(RandomSymbol) + if len(rvs) > 1: + raise NotImplementedError() + if len(rvs) == 0: + return arg + + rv = rvs.pop() + if rv.pspace is None: + raise ValueError("Probability space not known") + + symbol = rv.symbol + if symbol.name[0].isupper(): + symbol = Symbol(symbol.name.lower()) + else : + symbol = Symbol(symbol.name + "_1") + + if rv.pspace.is_Continuous: + return Integral(arg.replace(rv, symbol)*Probability(Eq(rv, symbol), condition), (symbol, rv.pspace.domain.set.inf, rv.pspace.domain.set.sup)) + else: + if rv.pspace.is_Finite: + raise NotImplementedError + else: + return Sum(arg.replace(rv, symbol)*Probability(Eq(rv, symbol), condition), (symbol, rv.pspace.domain.set.inf, rv.pspace.set.sup)) + + def _eval_rewrite_as_Integral(self, arg, condition=None, evaluate=False, **kwargs): + return self.func(arg, condition=condition).doit(deep=False, evaluate=evaluate) + + _eval_rewrite_as_Sum = _eval_rewrite_as_Integral # For discrete this will be Sum + + def evaluate_integral(self): + return self.rewrite(Integral).doit() + + evaluate_sum = evaluate_integral + +class Variance(Expr): + """ + Symbolic expression for the variance. + + Examples + ======== + + >>> from sympy import symbols, Integral + >>> from sympy.stats import Normal, Expectation, Variance, Probability + >>> mu = symbols("mu", positive=True) + >>> sigma = symbols("sigma", positive=True) + >>> X = Normal("X", mu, sigma) + >>> Variance(X) + Variance(X) + >>> Variance(X).evaluate_integral() + sigma**2 + + Integral representation of the underlying calculations: + + >>> Variance(X).rewrite(Integral) + Integral(sqrt(2)*(X - Integral(sqrt(2)*X*exp(-(X - mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (X, -oo, oo)))**2*exp(-(X - mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (X, -oo, oo)) + + Integral representation, without expanding the PDF: + + >>> Variance(X).rewrite(Probability) + -Integral(x*Probability(Eq(X, x)), (x, -oo, oo))**2 + Integral(x**2*Probability(Eq(X, x)), (x, -oo, oo)) + + Rewrite the variance in terms of the expectation + + >>> Variance(X).rewrite(Expectation) + -Expectation(X)**2 + Expectation(X**2) + + Some transformations based on the properties of the variance may happen: + + >>> from sympy.abc import a + >>> Y = Normal("Y", 0, 1) + >>> Variance(a*X) + Variance(a*X) + + To expand the variance in its expression, use ``expand()``: + + >>> Variance(a*X).expand() + a**2*Variance(X) + >>> Variance(X + Y) + Variance(X + Y) + >>> Variance(X + Y).expand() + 2*Covariance(X, Y) + Variance(X) + Variance(Y) + + """ + def __new__(cls, arg, condition=None, **kwargs): + arg = _sympify(arg) + + if arg.is_Matrix: + from sympy.stats.symbolic_multivariate_probability import VarianceMatrix + return VarianceMatrix(arg, condition) + if condition is None: + obj = Expr.__new__(cls, arg) + else: + condition = _sympify(condition) + obj = Expr.__new__(cls, arg, condition) + obj._condition = condition + return obj + + def _eval_is_commutative(self): + return self.args[0].is_commutative + + def expand(self, **hints): + arg = self.args[0] + condition = self._condition + + if not is_random(arg): + return S.Zero + + if isinstance(arg, RandomSymbol): + return self + elif isinstance(arg, Add): + rv = [] + for a in arg.args: + if is_random(a): + rv.append(a) + variances = Add(*(Variance(xv, condition).expand() for xv in rv)) + map_to_covar = lambda x: 2*Covariance(*x, condition=condition).expand() + covariances = Add(*map(map_to_covar, itertools.combinations(rv, 2))) + return variances + covariances + elif isinstance(arg, Mul): + nonrv = [] + rv = [] + for a in arg.args: + if is_random(a): + rv.append(a) + else: + nonrv.append(a**2) + if len(rv) == 0: + return S.Zero + return Mul.fromiter(nonrv)*Variance(Mul.fromiter(rv), condition) + + # this expression contains a RandomSymbol somehow: + return self + + def _eval_rewrite_as_Expectation(self, arg, condition=None, **kwargs): + e1 = Expectation(arg**2, condition) + e2 = Expectation(arg, condition)**2 + return e1 - e2 + + def _eval_rewrite_as_Probability(self, arg, condition=None, **kwargs): + return self.rewrite(Expectation).rewrite(Probability) + + def _eval_rewrite_as_Integral(self, arg, condition=None, **kwargs): + return variance(self.args[0], self._condition, evaluate=False) + + _eval_rewrite_as_Sum = _eval_rewrite_as_Integral + + def evaluate_integral(self): + return self.rewrite(Integral).doit() + + +class Covariance(Expr): + """ + Symbolic expression for the covariance. + + Examples + ======== + + >>> from sympy.stats import Covariance + >>> from sympy.stats import Normal + >>> X = Normal("X", 3, 2) + >>> Y = Normal("Y", 0, 1) + >>> Z = Normal("Z", 0, 1) + >>> W = Normal("W", 0, 1) + >>> cexpr = Covariance(X, Y) + >>> cexpr + Covariance(X, Y) + + Evaluate the covariance, `X` and `Y` are independent, + therefore zero is the result: + + >>> cexpr.evaluate_integral() + 0 + + Rewrite the covariance expression in terms of expectations: + + >>> from sympy.stats import Expectation + >>> cexpr.rewrite(Expectation) + Expectation(X*Y) - Expectation(X)*Expectation(Y) + + In order to expand the argument, use ``expand()``: + + >>> from sympy.abc import a, b, c, d + >>> Covariance(a*X + b*Y, c*Z + d*W) + Covariance(a*X + b*Y, c*Z + d*W) + >>> Covariance(a*X + b*Y, c*Z + d*W).expand() + a*c*Covariance(X, Z) + a*d*Covariance(W, X) + b*c*Covariance(Y, Z) + b*d*Covariance(W, Y) + + This class is aware of some properties of the covariance: + + >>> Covariance(X, X).expand() + Variance(X) + >>> Covariance(a*X, b*Y).expand() + a*b*Covariance(X, Y) + """ + + def __new__(cls, arg1, arg2, condition=None, **kwargs): + arg1 = _sympify(arg1) + arg2 = _sympify(arg2) + + if arg1.is_Matrix or arg2.is_Matrix: + from sympy.stats.symbolic_multivariate_probability import CrossCovarianceMatrix + return CrossCovarianceMatrix(arg1, arg2, condition) + + if kwargs.pop('evaluate', global_parameters.evaluate): + arg1, arg2 = sorted([arg1, arg2], key=default_sort_key) + + if condition is None: + obj = Expr.__new__(cls, arg1, arg2) + else: + condition = _sympify(condition) + obj = Expr.__new__(cls, arg1, arg2, condition) + obj._condition = condition + return obj + + def _eval_is_commutative(self): + return self.args[0].is_commutative + + def expand(self, **hints): + arg1 = self.args[0] + arg2 = self.args[1] + condition = self._condition + + if arg1 == arg2: + return Variance(arg1, condition).expand() + + if not is_random(arg1): + return S.Zero + if not is_random(arg2): + return S.Zero + + arg1, arg2 = sorted([arg1, arg2], key=default_sort_key) + + if isinstance(arg1, RandomSymbol) and isinstance(arg2, RandomSymbol): + return Covariance(arg1, arg2, condition) + + coeff_rv_list1 = self._expand_single_argument(arg1.expand()) + coeff_rv_list2 = self._expand_single_argument(arg2.expand()) + + addends = [a*b*Covariance(*sorted([r1, r2], key=default_sort_key), condition=condition) + for (a, r1) in coeff_rv_list1 for (b, r2) in coeff_rv_list2] + return Add.fromiter(addends) + + @classmethod + def _expand_single_argument(cls, expr): + # return (coefficient, random_symbol) pairs: + if isinstance(expr, RandomSymbol): + return [(S.One, expr)] + elif isinstance(expr, Add): + outval = [] + for a in expr.args: + if isinstance(a, Mul): + outval.append(cls._get_mul_nonrv_rv_tuple(a)) + elif is_random(a): + outval.append((S.One, a)) + + return outval + elif isinstance(expr, Mul): + return [cls._get_mul_nonrv_rv_tuple(expr)] + elif is_random(expr): + return [(S.One, expr)] + + @classmethod + def _get_mul_nonrv_rv_tuple(cls, m): + rv = [] + nonrv = [] + for a in m.args: + if is_random(a): + rv.append(a) + else: + nonrv.append(a) + return (Mul.fromiter(nonrv), Mul.fromiter(rv)) + + def _eval_rewrite_as_Expectation(self, arg1, arg2, condition=None, **kwargs): + e1 = Expectation(arg1*arg2, condition) + e2 = Expectation(arg1, condition)*Expectation(arg2, condition) + return e1 - e2 + + def _eval_rewrite_as_Probability(self, arg1, arg2, condition=None, **kwargs): + return self.rewrite(Expectation).rewrite(Probability) + + def _eval_rewrite_as_Integral(self, arg1, arg2, condition=None, **kwargs): + return covariance(self.args[0], self.args[1], self._condition, evaluate=False) + + _eval_rewrite_as_Sum = _eval_rewrite_as_Integral + + def evaluate_integral(self): + return self.rewrite(Integral).doit() + + +class Moment(Expr): + """ + Symbolic class for Moment + + Examples + ======== + + >>> from sympy import Symbol, Integral + >>> from sympy.stats import Normal, Expectation, Probability, Moment + >>> mu = Symbol('mu', real=True) + >>> sigma = Symbol('sigma', positive=True) + >>> X = Normal('X', mu, sigma) + >>> M = Moment(X, 3, 1) + + To evaluate the result of Moment use `doit`: + + >>> M.doit() + mu**3 - 3*mu**2 + 3*mu*sigma**2 + 3*mu - 3*sigma**2 - 1 + + Rewrite the Moment expression in terms of Expectation: + + >>> M.rewrite(Expectation) + Expectation((X - 1)**3) + + Rewrite the Moment expression in terms of Probability: + + >>> M.rewrite(Probability) + Integral((x - 1)**3*Probability(Eq(X, x)), (x, -oo, oo)) + + Rewrite the Moment expression in terms of Integral: + + >>> M.rewrite(Integral) + Integral(sqrt(2)*(X - 1)**3*exp(-(X - mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (X, -oo, oo)) + + """ + def __new__(cls, X, n, c=0, condition=None, **kwargs): + X = _sympify(X) + n = _sympify(n) + c = _sympify(c) + if condition is not None: + condition = _sympify(condition) + return super().__new__(cls, X, n, c, condition) + else: + return super().__new__(cls, X, n, c) + + def doit(self, **hints): + return self.rewrite(Expectation).doit(**hints) + + def _eval_rewrite_as_Expectation(self, X, n, c=0, condition=None, **kwargs): + return Expectation((X - c)**n, condition) + + def _eval_rewrite_as_Probability(self, X, n, c=0, condition=None, **kwargs): + return self.rewrite(Expectation).rewrite(Probability) + + def _eval_rewrite_as_Integral(self, X, n, c=0, condition=None, **kwargs): + return self.rewrite(Expectation).rewrite(Integral) + + +class CentralMoment(Expr): + """ + Symbolic class Central Moment + + Examples + ======== + + >>> from sympy import Symbol, Integral + >>> from sympy.stats import Normal, Expectation, Probability, CentralMoment + >>> mu = Symbol('mu', real=True) + >>> sigma = Symbol('sigma', positive=True) + >>> X = Normal('X', mu, sigma) + >>> CM = CentralMoment(X, 4) + + To evaluate the result of CentralMoment use `doit`: + + >>> CM.doit().simplify() + 3*sigma**4 + + Rewrite the CentralMoment expression in terms of Expectation: + + >>> CM.rewrite(Expectation) + Expectation((-Expectation(X) + X)**4) + + Rewrite the CentralMoment expression in terms of Probability: + + >>> CM.rewrite(Probability) + Integral((x - Integral(x*Probability(True), (x, -oo, oo)))**4*Probability(Eq(X, x)), (x, -oo, oo)) + + Rewrite the CentralMoment expression in terms of Integral: + + >>> CM.rewrite(Integral) + Integral(sqrt(2)*(X - Integral(sqrt(2)*X*exp(-(X - mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (X, -oo, oo)))**4*exp(-(X - mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (X, -oo, oo)) + + """ + def __new__(cls, X, n, condition=None, **kwargs): + X = _sympify(X) + n = _sympify(n) + if condition is not None: + condition = _sympify(condition) + return super().__new__(cls, X, n, condition) + else: + return super().__new__(cls, X, n) + + def doit(self, **hints): + return self.rewrite(Expectation).doit(**hints) + + def _eval_rewrite_as_Expectation(self, X, n, condition=None, **kwargs): + mu = Expectation(X, condition, **kwargs) + return Moment(X, n, mu, condition, **kwargs).rewrite(Expectation) + + def _eval_rewrite_as_Probability(self, X, n, condition=None, **kwargs): + return self.rewrite(Expectation).rewrite(Probability) + + def _eval_rewrite_as_Integral(self, X, n, condition=None, **kwargs): + return self.rewrite(Expectation).rewrite(Integral) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_compound_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_compound_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..573ba364b686738e56bb1c4615acd2a9bc8bf3ae --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_compound_rv.py @@ -0,0 +1,159 @@ +from sympy.concrete.summations import Sum +from sympy.core.numbers import (oo, pi) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import symbols +from sympy.functions.combinatorial.factorials import factorial +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.beta_functions import beta +from sympy.functions.special.error_functions import erf +from sympy.functions.special.gamma_functions import gamma +from sympy.integrals.integrals import Integral +from sympy.sets.sets import Interval +from sympy.stats import (Normal, P, E, density, Gamma, Poisson, Rayleigh, + variance, Bernoulli, Beta, Uniform, cdf) +from sympy.stats.compound_rv import CompoundDistribution, CompoundPSpace +from sympy.stats.crv_types import NormalDistribution +from sympy.stats.drv_types import PoissonDistribution +from sympy.stats.frv_types import BernoulliDistribution +from sympy.testing.pytest import raises, ignore_warnings +from sympy.stats.joint_rv_types import MultivariateNormalDistribution + +from sympy.abc import x + + +# helpers for testing troublesome unevaluated expressions +flat = lambda s: ''.join(str(s).split()) +streq = lambda *a: len(set(map(flat, a))) == 1 +assert streq(x, x) +assert streq(x, 'x') +assert not streq(x, x + 1) + + +def test_normal_CompoundDist(): + X = Normal('X', 1, 2) + Y = Normal('X', X, 4) + assert density(Y)(x).simplify() == sqrt(10)*exp(-x**2/40 + x/20 - S(1)/40)/(20*sqrt(pi)) + assert E(Y) == 1 # it is always equal to mean of X + assert P(Y > 1) == S(1)/2 # as 1 is the mean + assert P(Y > 5).simplify() == S(1)/2 - erf(sqrt(10)/5)/2 + assert variance(Y) == variance(X) + 4**2 # 2**2 + 4**2 + # https://math.stackexchange.com/questions/1484451/ + # (Contains proof of E and variance computation) + + +def test_poisson_CompoundDist(): + k, t, y = symbols('k t y', positive=True, real=True) + G = Gamma('G', k, t) + D = Poisson('P', G) + assert density(D)(y).simplify() == t**y*(t + 1)**(-k - y)*gamma(k + y)/(gamma(k)*gamma(y + 1)) + # https://en.wikipedia.org/wiki/Negative_binomial_distribution#Gamma%E2%80%93Poisson_mixture + assert E(D).simplify() == k*t # mean of NegativeBinomialDistribution + + +def test_bernoulli_CompoundDist(): + X = Beta('X', 1, 2) + Y = Bernoulli('Y', X) + assert density(Y).dict == {0: S(2)/3, 1: S(1)/3} + assert E(Y) == P(Eq(Y, 1)) == S(1)/3 + assert variance(Y) == S(2)/9 + assert cdf(Y) == {0: S(2)/3, 1: 1} + + # test issue 8128 + a = Bernoulli('a', S(1)/2) + b = Bernoulli('b', a) + assert density(b).dict == {0: S(1)/2, 1: S(1)/2} + assert P(b > 0.5) == S(1)/2 + + X = Uniform('X', 0, 1) + Y = Bernoulli('Y', X) + assert E(Y) == S(1)/2 + assert P(Eq(Y, 1)) == E(Y) + + +def test_unevaluated_CompoundDist(): + # these tests need to be removed once they work with evaluation as they are currently not + # evaluated completely in sympy. + R = Rayleigh('R', 4) + X = Normal('X', 3, R) + ans = ''' + Piecewise(((-sqrt(pi)*sinh(x/4 - 3/4) + sqrt(pi)*cosh(x/4 - 3/4))/( + 8*sqrt(pi)), Abs(arg(x - 3)) <= pi/4), (Integral(sqrt(2)*exp(-(x - 3) + **2/(2*R**2))*exp(-R**2/32)/(32*sqrt(pi)), (R, 0, oo)), True))''' + assert streq(density(X)(x), ans) + + expre = ''' + Integral(X*Integral(sqrt(2)*exp(-(X-3)**2/(2*R**2))*exp(-R**2/32)/(32* + sqrt(pi)),(R,0,oo)),(X,-oo,oo))''' + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + assert streq(E(X, evaluate=False).rewrite(Integral), expre) + + X = Poisson('X', 1) + Y = Poisson('Y', X) + Z = Poisson('Z', Y) + exprd = Sum(exp(-Y)*Y**x*Sum(exp(-1)*exp(-X)*X**Y/(factorial(X)*factorial(Y) + ), (X, 0, oo))/factorial(x), (Y, 0, oo)) + assert density(Z)(x) == exprd + + N = Normal('N', 1, 2) + M = Normal('M', 3, 4) + D = Normal('D', M, N) + exprd = ''' + Integral(sqrt(2)*exp(-(N-1)**2/8)*Integral(exp(-(x-M)**2/(2*N**2))*exp + (-(M-3)**2/32)/(8*pi*N),(M,-oo,oo))/(4*sqrt(pi)),(N,-oo,oo))''' + assert streq(density(D, evaluate=False)(x), exprd) + + +def test_Compound_Distribution(): + X = Normal('X', 2, 4) + N = NormalDistribution(X, 4) + C = CompoundDistribution(N) + assert C.is_Continuous + assert C.set == Interval(-oo, oo) + assert C.pdf(x, evaluate=True).simplify() == exp(-x**2/64 + x/16 - S(1)/16)/(8*sqrt(pi)) + + assert not isinstance(CompoundDistribution(NormalDistribution(2, 3)), + CompoundDistribution) + M = MultivariateNormalDistribution([1, 2], [[2, 1], [1, 2]]) + raises(NotImplementedError, lambda: CompoundDistribution(M)) + + X = Beta('X', 2, 4) + B = BernoulliDistribution(X, 1, 0) + C = CompoundDistribution(B) + assert C.is_Finite + assert C.set == {0, 1} + y = symbols('y', negative=False, integer=True) + assert C.pdf(y, evaluate=True) == Piecewise((S(1)/(30*beta(2, 4)), Eq(y, 0)), + (S(1)/(60*beta(2, 4)), Eq(y, 1)), (0, True)) + + k, t, z = symbols('k t z', positive=True, real=True) + G = Gamma('G', k, t) + X = PoissonDistribution(G) + C = CompoundDistribution(X) + assert C.is_Discrete + assert C.set == S.Naturals0 + assert C.pdf(z, evaluate=True).simplify() == t**z*(t + 1)**(-k - z)*gamma(k \ + + z)/(gamma(k)*gamma(z + 1)) + + +def test_compound_pspace(): + X = Normal('X', 2, 4) + Y = Normal('Y', 3, 6) + assert not isinstance(Y.pspace, CompoundPSpace) + N = NormalDistribution(1, 2) + D = PoissonDistribution(3) + B = BernoulliDistribution(0.2, 1, 0) + pspace1 = CompoundPSpace('N', N) + pspace2 = CompoundPSpace('D', D) + pspace3 = CompoundPSpace('B', B) + assert not isinstance(pspace1, CompoundPSpace) + assert not isinstance(pspace2, CompoundPSpace) + assert not isinstance(pspace3, CompoundPSpace) + M = MultivariateNormalDistribution([1, 2], [[2, 1], [1, 2]]) + raises(ValueError, lambda: CompoundPSpace('M', M)) + Y = Normal('Y', X, 6) + assert isinstance(Y.pspace, CompoundPSpace) + assert Y.pspace.distribution == CompoundDistribution(NormalDistribution(X, 6)) + assert Y.pspace.domain.set == Interval(-oo, oo) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_continuous_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_continuous_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..b2c4206b5c29ffd3194d1ae05e57c51c9c1b6d78 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_continuous_rv.py @@ -0,0 +1,1583 @@ +from sympy.concrete.summations import Sum +from sympy.core.function import (Lambda, diff, expand_func) +from sympy.core.mul import Mul +from sympy.core import EulerGamma +from sympy.core.numbers import (E as e, I, Rational, pi) +from sympy.core.relational import (Eq, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol, symbols) +from sympy.functions.combinatorial.factorials import (binomial, factorial) +from sympy.functions.elementary.complexes import (Abs, im, re, sign) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.hyperbolic import (cosh, sinh) +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import (asin, atan, cos, sin, tan) +from sympy.functions.special.bessel import (besseli, besselj, besselk) +from sympy.functions.special.beta_functions import beta +from sympy.functions.special.error_functions import (erf, erfc, erfi, expint) +from sympy.functions.special.gamma_functions import (gamma, lowergamma, uppergamma) +from sympy.functions.special.zeta_functions import zeta +from sympy.functions.special.hyper import hyper +from sympy.integrals.integrals import Integral +from sympy.logic.boolalg import (And, Or) +from sympy.sets.sets import Interval +from sympy.simplify.simplify import simplify +from sympy.utilities.lambdify import lambdify +from sympy.functions.special.error_functions import erfinv +from sympy.functions.special.hyper import meijerg +from sympy.sets.sets import FiniteSet, Complement, Intersection +from sympy.stats import (P, E, where, density, variance, covariance, skewness, kurtosis, median, + given, pspace, cdf, characteristic_function, moment_generating_function, + ContinuousRV, Arcsin, Benini, Beta, BetaNoncentral, BetaPrime, + Cauchy, Chi, ChiSquared, ChiNoncentral, Dagum, Davis, Erlang, ExGaussian, + Exponential, ExponentialPower, FDistribution, FisherZ, Frechet, Gamma, + GammaInverse, Gompertz, Gumbel, Kumaraswamy, Laplace, Levy, Logistic, LogCauchy, + LogLogistic, LogitNormal, LogNormal, Maxwell, Moyal, Nakagami, Normal, GaussianInverse, + Pareto, PowerFunction, QuadraticU, RaisedCosine, Rayleigh, Reciprocal, ShiftedGompertz, StudentT, + Trapezoidal, Triangular, Uniform, UniformSum, VonMises, Weibull, coskewness, + WignerSemicircle, Wald, correlation, moment, cmoment, smoment, quantile, + Lomax, BoundedPareto) + +from sympy.stats.crv_types import NormalDistribution, ExponentialDistribution, ContinuousDistributionHandmade +from sympy.stats.joint_rv_types import MultivariateLaplaceDistribution, MultivariateNormalDistribution +from sympy.stats.crv import SingleContinuousPSpace, SingleContinuousDomain +from sympy.stats.compound_rv import CompoundPSpace +from sympy.stats.symbolic_probability import Probability +from sympy.testing.pytest import raises, XFAIL, slow, ignore_warnings +from sympy.core.random import verify_numerically as tn + +oo = S.Infinity + +x, y, z = map(Symbol, 'xyz') + +def test_single_normal(): + mu = Symbol('mu', real=True) + sigma = Symbol('sigma', positive=True) + X = Normal('x', 0, 1) + Y = X*sigma + mu + + assert E(Y) == mu + assert variance(Y) == sigma**2 + pdf = density(Y) + x = Symbol('x', real=True) + assert (pdf(x) == + 2**S.Half*exp(-(x - mu)**2/(2*sigma**2))/(2*pi**S.Half*sigma)) + + assert P(X**2 < 1) == erf(2**S.Half/2) + ans = quantile(Y)(x) + assert ans == Complement(Intersection(FiniteSet( + sqrt(2)*sigma*(sqrt(2)*mu/(2*sigma)+ erfinv(2*x - 1))), + Interval(-oo, oo)), FiniteSet(mu)) + assert E(X, Eq(X, mu)) == mu + + assert median(X) == FiniteSet(0) + # issue 8248 + assert X.pspace.compute_expectation(1).doit() == 1 + + +def test_conditional_1d(): + X = Normal('x', 0, 1) + Y = given(X, X >= 0) + z = Symbol('z') + + assert density(Y)(z) == 2 * density(X)(z) + + assert Y.pspace.domain.set == Interval(0, oo) + assert E(Y) == sqrt(2) / sqrt(pi) + + assert E(X**2) == E(Y**2) + + +def test_ContinuousDomain(): + X = Normal('x', 0, 1) + assert where(X**2 <= 1).set == Interval(-1, 1) + assert where(X**2 <= 1).symbol == X.symbol + assert where(And(X**2 <= 1, X >= 0)).set == Interval(0, 1) + raises(ValueError, lambda: where(sin(X) > 1)) + + Y = given(X, X >= 0) + + assert Y.pspace.domain.set == Interval(0, oo) + + +def test_multiple_normal(): + X, Y = Normal('x', 0, 1), Normal('y', 0, 1) + p = Symbol("p", positive=True) + + assert E(X + Y) == 0 + assert variance(X + Y) == 2 + assert variance(X + X) == 4 + assert covariance(X, Y) == 0 + assert covariance(2*X + Y, -X) == -2*variance(X) + assert skewness(X) == 0 + assert skewness(X + Y) == 0 + assert kurtosis(X) == 3 + assert kurtosis(X+Y) == 3 + assert correlation(X, Y) == 0 + assert correlation(X, X + Y) == correlation(X, X - Y) + assert moment(X, 2) == 1 + assert cmoment(X, 3) == 0 + assert moment(X + Y, 4) == 12 + assert cmoment(X, 2) == variance(X) + assert smoment(X*X, 2) == 1 + assert smoment(X + Y, 3) == skewness(X + Y) + assert smoment(X + Y, 4) == kurtosis(X + Y) + assert E(X, Eq(X + Y, 0)) == 0 + assert variance(X, Eq(X + Y, 0)) == S.Half + assert quantile(X)(p) == sqrt(2)*erfinv(2*p - S.One) + + +def test_symbolic(): + mu1, mu2 = symbols('mu1 mu2', real=True) + s1, s2 = symbols('sigma1 sigma2', positive=True) + rate = Symbol('lambda', positive=True) + X = Normal('x', mu1, s1) + Y = Normal('y', mu2, s2) + Z = Exponential('z', rate) + a, b, c = symbols('a b c', real=True) + + assert E(X) == mu1 + assert E(X + Y) == mu1 + mu2 + assert E(a*X + b) == a*E(X) + b + assert variance(X) == s1**2 + assert variance(X + a*Y + b) == variance(X) + a**2*variance(Y) + + assert E(Z) == 1/rate + assert E(a*Z + b) == a*E(Z) + b + assert E(X + a*Z + b) == mu1 + a/rate + b + assert median(X) == FiniteSet(mu1) + + +def test_cdf(): + X = Normal('x', 0, 1) + + d = cdf(X) + assert P(X < 1) == d(1).rewrite(erfc) + assert d(0) == S.Half + + d = cdf(X, X > 0) # given X>0 + assert d(0) == 0 + + Y = Exponential('y', 10) + d = cdf(Y) + assert d(-5) == 0 + assert P(Y > 3) == 1 - d(3) + + raises(ValueError, lambda: cdf(X + Y)) + + Z = Exponential('z', 1) + f = cdf(Z) + assert f(z) == Piecewise((1 - exp(-z), z >= 0), (0, True)) + + +def test_characteristic_function(): + X = Uniform('x', 0, 1) + + cf = characteristic_function(X) + assert cf(1) == -I*(-1 + exp(I)) + + Y = Normal('y', 1, 1) + cf = characteristic_function(Y) + assert cf(0) == 1 + assert cf(1) == exp(I - S.Half) + + Z = Exponential('z', 5) + cf = characteristic_function(Z) + assert cf(0) == 1 + assert cf(1).expand() == Rational(25, 26) + I*5/26 + + X = GaussianInverse('x', 1, 1) + cf = characteristic_function(X) + assert cf(0) == 1 + assert cf(1) == exp(1 - sqrt(1 - 2*I)) + + X = ExGaussian('x', 0, 1, 1) + cf = characteristic_function(X) + assert cf(0) == 1 + assert cf(1) == (1 + I)*exp(Rational(-1, 2))/2 + + L = Levy('x', 0, 1) + cf = characteristic_function(L) + assert cf(0) == 1 + assert cf(1) == exp(-sqrt(2)*sqrt(-I)) + + +def test_moment_generating_function(): + t = symbols('t', positive=True) + + # Symbolic tests + a, b, c = symbols('a b c') + + mgf = moment_generating_function(Beta('x', a, b))(t) + assert mgf == hyper((a,), (a + b,), t) + + mgf = moment_generating_function(Chi('x', a))(t) + assert mgf == sqrt(2)*t*gamma(a/2 + S.Half)*\ + hyper((a/2 + S.Half,), (Rational(3, 2),), t**2/2)/gamma(a/2) +\ + hyper((a/2,), (S.Half,), t**2/2) + + mgf = moment_generating_function(ChiSquared('x', a))(t) + assert mgf == (1 - 2*t)**(-a/2) + + mgf = moment_generating_function(Erlang('x', a, b))(t) + assert mgf == (1 - t/b)**(-a) + + mgf = moment_generating_function(ExGaussian("x", a, b, c))(t) + assert mgf == exp(a*t + b**2*t**2/2)/(1 - t/c) + + mgf = moment_generating_function(Exponential('x', a))(t) + assert mgf == a/(a - t) + + mgf = moment_generating_function(Gamma('x', a, b))(t) + assert mgf == (-b*t + 1)**(-a) + + mgf = moment_generating_function(Gumbel('x', a, b))(t) + assert mgf == exp(b*t)*gamma(-a*t + 1) + + mgf = moment_generating_function(Gompertz('x', a, b))(t) + assert mgf == b*exp(b)*expint(t/a, b) + + mgf = moment_generating_function(Laplace('x', a, b))(t) + assert mgf == exp(a*t)/(-b**2*t**2 + 1) + + mgf = moment_generating_function(Logistic('x', a, b))(t) + assert mgf == exp(a*t)*beta(-b*t + 1, b*t + 1) + + mgf = moment_generating_function(Normal('x', a, b))(t) + assert mgf == exp(a*t + b**2*t**2/2) + + mgf = moment_generating_function(Pareto('x', a, b))(t) + assert mgf == b*(-a*t)**b*uppergamma(-b, -a*t) + + mgf = moment_generating_function(QuadraticU('x', a, b))(t) + assert str(mgf) == ("(3*(t*(-4*b + (a + b)**2) + 4)*exp(b*t) - " + "3*(t*(a**2 + 2*a*(b - 2) + b**2) + 4)*exp(a*t))/(t**2*(a - b)**3)") + + mgf = moment_generating_function(RaisedCosine('x', a, b))(t) + assert mgf == pi**2*exp(a*t)*sinh(b*t)/(b*t*(b**2*t**2 + pi**2)) + + mgf = moment_generating_function(Rayleigh('x', a))(t) + assert mgf == sqrt(2)*sqrt(pi)*a*t*(erf(sqrt(2)*a*t/2) + 1)\ + *exp(a**2*t**2/2)/2 + 1 + + mgf = moment_generating_function(Triangular('x', a, b, c))(t) + assert str(mgf) == ("(-2*(-a + b)*exp(c*t) + 2*(-a + c)*exp(b*t) + " + "2*(b - c)*exp(a*t))/(t**2*(-a + b)*(-a + c)*(b - c))") + + mgf = moment_generating_function(Uniform('x', a, b))(t) + assert mgf == (-exp(a*t) + exp(b*t))/(t*(-a + b)) + + mgf = moment_generating_function(UniformSum('x', a))(t) + assert mgf == ((exp(t) - 1)/t)**a + + mgf = moment_generating_function(WignerSemicircle('x', a))(t) + assert mgf == 2*besseli(1, a*t)/(a*t) + + # Numeric tests + + mgf = moment_generating_function(Beta('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 1) == hyper((2,), (3,), 1)/2 + + mgf = moment_generating_function(Chi('x', 1))(t) + assert mgf.diff(t).subs(t, 1) == sqrt(2)*hyper((1,), (Rational(3, 2),), S.Half + )/sqrt(pi) + hyper((Rational(3, 2),), (Rational(3, 2),), S.Half) + 2*sqrt(2)*hyper((2,), + (Rational(5, 2),), S.Half)/(3*sqrt(pi)) + + mgf = moment_generating_function(ChiSquared('x', 1))(t) + assert mgf.diff(t).subs(t, 1) == I + + mgf = moment_generating_function(Erlang('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 0) == 1 + + mgf = moment_generating_function(ExGaussian("x", 0, 1, 1))(t) + assert mgf.diff(t).subs(t, 2) == -exp(2) + + mgf = moment_generating_function(Exponential('x', 1))(t) + assert mgf.diff(t).subs(t, 0) == 1 + + mgf = moment_generating_function(Gamma('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 0) == 1 + + mgf = moment_generating_function(Gumbel('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 0) == EulerGamma + 1 + + mgf = moment_generating_function(Gompertz('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 1) == -e*meijerg(((), (1, 1)), + ((0, 0, 0), ()), 1) + + mgf = moment_generating_function(Laplace('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 0) == 1 + + mgf = moment_generating_function(Logistic('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 0) == beta(1, 1) + + mgf = moment_generating_function(Normal('x', 0, 1))(t) + assert mgf.diff(t).subs(t, 1) == exp(S.Half) + + mgf = moment_generating_function(Pareto('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 0) == expint(1, 0) + + mgf = moment_generating_function(QuadraticU('x', 1, 2))(t) + assert mgf.diff(t).subs(t, 1) == -12*e - 3*exp(2) + + mgf = moment_generating_function(RaisedCosine('x', 1, 1))(t) + assert mgf.diff(t).subs(t, 1) == -2*e*pi**2*sinh(1)/\ + (1 + pi**2)**2 + e*pi**2*cosh(1)/(1 + pi**2) + + mgf = moment_generating_function(Rayleigh('x', 1))(t) + assert mgf.diff(t).subs(t, 0) == sqrt(2)*sqrt(pi)/2 + + mgf = moment_generating_function(Triangular('x', 1, 3, 2))(t) + assert mgf.diff(t).subs(t, 1) == -e + exp(3) + + mgf = moment_generating_function(Uniform('x', 0, 1))(t) + assert mgf.diff(t).subs(t, 1) == 1 + + mgf = moment_generating_function(UniformSum('x', 1))(t) + assert mgf.diff(t).subs(t, 1) == 1 + + mgf = moment_generating_function(WignerSemicircle('x', 1))(t) + assert mgf.diff(t).subs(t, 1) == -2*besseli(1, 1) + besseli(2, 1) +\ + besseli(0, 1) + + +def test_ContinuousRV(): + pdf = sqrt(2)*exp(-x**2/2)/(2*sqrt(pi)) # Normal distribution + # X and Y should be equivalent + X = ContinuousRV(x, pdf, check=True) + Y = Normal('y', 0, 1) + + assert variance(X) == variance(Y) + assert P(X > 0) == P(Y > 0) + Z = ContinuousRV(z, exp(-z), set=Interval(0, oo)) + assert Z.pspace.domain.set == Interval(0, oo) + assert E(Z) == 1 + assert P(Z > 5) == exp(-5) + raises(ValueError, lambda: ContinuousRV(z, exp(-z), set=Interval(0, 10), check=True)) + + # the correct pdf for Gamma(k, theta) but the integral in `check` + # integrates to something equivalent to 1 and not to 1 exactly + _x, k, theta = symbols("x k theta", positive=True) + pdf = 1/(gamma(k)*theta**k)*_x**(k-1)*exp(-_x/theta) + X = ContinuousRV(_x, pdf, set=Interval(0, oo)) + Y = Gamma('y', k, theta) + assert (E(X) - E(Y)).simplify() == 0 + assert (variance(X) - variance(Y)).simplify() == 0 + + +def test_arcsin(): + + a = Symbol("a", real=True) + b = Symbol("b", real=True) + + X = Arcsin('x', a, b) + assert density(X)(x) == 1/(pi*sqrt((-x + b)*(x - a))) + assert cdf(X)(x) == Piecewise((0, a > x), + (2*asin(sqrt((-a + x)/(-a + b)))/pi, b >= x), + (1, True)) + assert pspace(X).domain.set == Interval(a, b) + +def test_benini(): + alpha = Symbol("alpha", positive=True) + beta = Symbol("beta", positive=True) + sigma = Symbol("sigma", positive=True) + X = Benini('x', alpha, beta, sigma) + + assert density(X)(x) == ((alpha/x + 2*beta*log(x/sigma)/x) + *exp(-alpha*log(x/sigma) - beta*log(x/sigma)**2)) + + assert pspace(X).domain.set == Interval(sigma, oo) + raises(NotImplementedError, lambda: moment_generating_function(X)) + alpha = Symbol("alpha", nonpositive=True) + raises(ValueError, lambda: Benini('x', alpha, beta, sigma)) + + beta = Symbol("beta", nonpositive=True) + raises(ValueError, lambda: Benini('x', alpha, beta, sigma)) + + alpha = Symbol("alpha", positive=True) + raises(ValueError, lambda: Benini('x', alpha, beta, sigma)) + + beta = Symbol("beta", positive=True) + sigma = Symbol("sigma", nonpositive=True) + raises(ValueError, lambda: Benini('x', alpha, beta, sigma)) + +def test_beta(): + a, b = symbols('alpha beta', positive=True) + B = Beta('x', a, b) + + assert pspace(B).domain.set == Interval(0, 1) + assert characteristic_function(B)(x) == hyper((a,), (a + b,), I*x) + assert density(B)(x) == x**(a - 1)*(1 - x)**(b - 1)/beta(a, b) + + assert simplify(E(B)) == a / (a + b) + assert simplify(variance(B)) == a*b / (a**3 + 3*a**2*b + a**2 + 3*a*b**2 + 2*a*b + b**3 + b**2) + + # Full symbolic solution is too much, test with numeric version + a, b = 1, 2 + B = Beta('x', a, b) + assert expand_func(E(B)) == a / S(a + b) + assert expand_func(variance(B)) == (a*b) / S((a + b)**2 * (a + b + 1)) + assert median(B) == FiniteSet(1 - 1/sqrt(2)) + +def test_beta_noncentral(): + a, b = symbols('a b', positive=True) + c = Symbol('c', nonnegative=True) + _k = Dummy('k') + + X = BetaNoncentral('x', a, b, c) + + assert pspace(X).domain.set == Interval(0, 1) + + dens = density(X) + z = Symbol('z') + + res = Sum( z**(_k + a - 1)*(c/2)**_k*(1 - z)**(b - 1)*exp(-c/2)/ + (beta(_k + a, b)*factorial(_k)), (_k, 0, oo)) + assert dens(z).dummy_eq(res) + + # BetaCentral should not raise if the assumptions + # on the symbols can not be determined + a, b, c = symbols('a b c') + assert BetaNoncentral('x', a, b, c) + + a = Symbol('a', positive=False, real=True) + raises(ValueError, lambda: BetaNoncentral('x', a, b, c)) + + a = Symbol('a', positive=True) + b = Symbol('b', positive=False, real=True) + raises(ValueError, lambda: BetaNoncentral('x', a, b, c)) + + a = Symbol('a', positive=True) + b = Symbol('b', positive=True) + c = Symbol('c', nonnegative=False, real=True) + raises(ValueError, lambda: BetaNoncentral('x', a, b, c)) + +def test_betaprime(): + alpha = Symbol("alpha", positive=True) + + betap = Symbol("beta", positive=True) + + X = BetaPrime('x', alpha, betap) + assert density(X)(x) == x**(alpha - 1)*(x + 1)**(-alpha - betap)/beta(alpha, betap) + + alpha = Symbol("alpha", nonpositive=True) + raises(ValueError, lambda: BetaPrime('x', alpha, betap)) + + alpha = Symbol("alpha", positive=True) + betap = Symbol("beta", nonpositive=True) + raises(ValueError, lambda: BetaPrime('x', alpha, betap)) + X = BetaPrime('x', 1, 1) + assert median(X) == FiniteSet(1) + + +def test_BoundedPareto(): + L, H = symbols('L, H', negative=True) + raises(ValueError, lambda: BoundedPareto('X', 1, L, H)) + L, H = symbols('L, H', real=False) + raises(ValueError, lambda: BoundedPareto('X', 1, L, H)) + L, H = symbols('L, H', positive=True) + raises(ValueError, lambda: BoundedPareto('X', -1, L, H)) + + X = BoundedPareto('X', 2, L, H) + assert X.pspace.domain.set == Interval(L, H) + assert density(X)(x) == 2*L**2/(x**3*(1 - L**2/H**2)) + assert cdf(X)(x) == Piecewise((-H**2*L**2/(x**2*(H**2 - L**2)) \ + + H**2/(H**2 - L**2), L <= x), (0, True)) + assert E(X).simplify() == 2*H*L/(H + L) + X = BoundedPareto('X', 1, 2, 4) + assert E(X).simplify() == log(16) + assert median(X) == FiniteSet(Rational(8, 3)) + assert variance(X).simplify() == 8 - 16*log(2)**2 + + +def test_cauchy(): + x0 = Symbol("x0", real=True) + gamma = Symbol("gamma", positive=True) + p = Symbol("p", positive=True) + + X = Cauchy('x', x0, gamma) + # Tests the characteristic function + assert characteristic_function(X)(x) == exp(-gamma*Abs(x) + I*x*x0) + raises(NotImplementedError, lambda: moment_generating_function(X)) + assert density(X)(x) == 1/(pi*gamma*(1 + (x - x0)**2/gamma**2)) + assert diff(cdf(X)(x), x) == density(X)(x) + assert quantile(X)(p) == gamma*tan(pi*(p - S.Half)) + x0 + + x1 = Symbol("x1", real=False) + raises(ValueError, lambda: Cauchy('x', x1, gamma)) + gamma = Symbol("gamma", nonpositive=True) + raises(ValueError, lambda: Cauchy('x', x0, gamma)) + assert median(X) == FiniteSet(x0) + +def test_chi(): + from sympy.core.numbers import I + k = Symbol("k", integer=True) + + X = Chi('x', k) + assert density(X)(x) == 2**(-k/2 + 1)*x**(k - 1)*exp(-x**2/2)/gamma(k/2) + + # Tests the characteristic function + assert characteristic_function(X)(x) == sqrt(2)*I*x*gamma(k/2 + S(1)/2)*hyper((k/2 + S(1)/2,), + (S(3)/2,), -x**2/2)/gamma(k/2) + hyper((k/2,), (S(1)/2,), -x**2/2) + + # Tests the moment generating function + assert moment_generating_function(X)(x) == sqrt(2)*x*gamma(k/2 + S(1)/2)*hyper((k/2 + S(1)/2,), + (S(3)/2,), x**2/2)/gamma(k/2) + hyper((k/2,), (S(1)/2,), x**2/2) + + k = Symbol("k", integer=True, positive=False) + raises(ValueError, lambda: Chi('x', k)) + + k = Symbol("k", integer=False, positive=True) + raises(ValueError, lambda: Chi('x', k)) + +def test_chi_noncentral(): + k = Symbol("k", integer=True) + l = Symbol("l") + + X = ChiNoncentral("x", k, l) + assert density(X)(x) == (x**k*l*(x*l)**(-k/2)* + exp(-x**2/2 - l**2/2)*besseli(k/2 - 1, x*l)) + + k = Symbol("k", integer=True, positive=False) + raises(ValueError, lambda: ChiNoncentral('x', k, l)) + + k = Symbol("k", integer=True, positive=True) + l = Symbol("l", nonpositive=True) + raises(ValueError, lambda: ChiNoncentral('x', k, l)) + + k = Symbol("k", integer=False) + l = Symbol("l", positive=True) + raises(ValueError, lambda: ChiNoncentral('x', k, l)) + + +def test_chi_squared(): + k = Symbol("k", integer=True) + X = ChiSquared('x', k) + + # Tests the characteristic function + assert characteristic_function(X)(x) == ((-2*I*x + 1)**(-k/2)) + + assert density(X)(x) == 2**(-k/2)*x**(k/2 - 1)*exp(-x/2)/gamma(k/2) + assert cdf(X)(x) == Piecewise((lowergamma(k/2, x/2)/gamma(k/2), x >= 0), (0, True)) + assert E(X) == k + assert variance(X) == 2*k + + X = ChiSquared('x', 15) + assert cdf(X)(3) == -14873*sqrt(6)*exp(Rational(-3, 2))/(5005*sqrt(pi)) + erf(sqrt(6)/2) + + k = Symbol("k", integer=True, positive=False) + raises(ValueError, lambda: ChiSquared('x', k)) + + k = Symbol("k", integer=False, positive=True) + raises(ValueError, lambda: ChiSquared('x', k)) + + +def test_dagum(): + p = Symbol("p", positive=True) + b = Symbol("b", positive=True) + a = Symbol("a", positive=True) + + X = Dagum('x', p, a, b) + assert density(X)(x) == a*p*(x/b)**(a*p)*((x/b)**a + 1)**(-p - 1)/x + assert cdf(X)(x) == Piecewise(((1 + (x/b)**(-a))**(-p), x >= 0), + (0, True)) + + p = Symbol("p", nonpositive=True) + raises(ValueError, lambda: Dagum('x', p, a, b)) + + p = Symbol("p", positive=True) + b = Symbol("b", nonpositive=True) + raises(ValueError, lambda: Dagum('x', p, a, b)) + + b = Symbol("b", positive=True) + a = Symbol("a", nonpositive=True) + raises(ValueError, lambda: Dagum('x', p, a, b)) + X = Dagum('x', 1, 1, 1) + assert median(X) == FiniteSet(1) + +def test_davis(): + b = Symbol("b", positive=True) + n = Symbol("n", positive=True) + mu = Symbol("mu", positive=True) + + X = Davis('x', b, n, mu) + dividend = b**n*(x - mu)**(-1-n) + divisor = (exp(b/(x-mu))-1)*(gamma(n)*zeta(n)) + assert density(X)(x) == dividend/divisor + + +def test_erlang(): + k = Symbol("k", integer=True, positive=True) + l = Symbol("l", positive=True) + + X = Erlang("x", k, l) + assert density(X)(x) == x**(k - 1)*l**k*exp(-x*l)/gamma(k) + assert cdf(X)(x) == Piecewise((lowergamma(k, l*x)/gamma(k), x > 0), + (0, True)) + + +def test_exgaussian(): + m, z = symbols("m, z") + s, l = symbols("s, l", positive=True) + X = ExGaussian("x", m, s, l) + + assert density(X)(z) == l*exp(l*(l*s**2 + 2*m - 2*z)/2) *\ + erfc(sqrt(2)*(l*s**2 + m - z)/(2*s))/2 + + # Note: actual_output simplifies to expected_output. + # Ideally cdf(X)(z) would return expected_output + # expected_output = (erf(sqrt(2)*(l*s**2 + m - z)/(2*s)) - 1)*exp(l*(l*s**2 + 2*m - 2*z)/2)/2 - erf(sqrt(2)*(m - z)/(2*s))/2 + S.Half + u = l*(z - m) + v = l*s + GaussianCDF1 = cdf(Normal('x', 0, v))(u) + GaussianCDF2 = cdf(Normal('x', v**2, v))(u) + actual_output = GaussianCDF1 - exp(-u + (v**2/2) + log(GaussianCDF2)) + assert cdf(X)(z) == actual_output + # assert simplify(actual_output) == expected_output + + assert variance(X).expand() == s**2 + l**(-2) + + assert skewness(X).expand() == 2/(l**3*s**2*sqrt(s**2 + l**(-2)) + l * + sqrt(s**2 + l**(-2))) + + +@slow +def test_exponential(): + rate = Symbol('lambda', positive=True) + X = Exponential('x', rate) + p = Symbol("p", positive=True, real=True) + + assert E(X) == 1/rate + assert variance(X) == 1/rate**2 + assert skewness(X) == 2 + assert skewness(X) == smoment(X, 3) + assert kurtosis(X) == 9 + assert kurtosis(X) == smoment(X, 4) + assert smoment(2*X, 4) == smoment(X, 4) + assert moment(X, 3) == 3*2*1/rate**3 + assert P(X > 0) is S.One + assert P(X > 1) == exp(-rate) + assert P(X > 10) == exp(-10*rate) + assert quantile(X)(p) == -log(1-p)/rate + + assert where(X <= 1).set == Interval(0, 1) + Y = Exponential('y', 1) + assert median(Y) == FiniteSet(log(2)) + #Test issue 9970 + z = Dummy('z') + assert P(X > z) == exp(-z*rate) + assert P(X < z) == 0 + #Test issue 10076 (Distribution with interval(0,oo)) + x = Symbol('x') + _z = Dummy('_z') + b = SingleContinuousPSpace(x, ExponentialDistribution(2)) + + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + expected1 = Integral(2*exp(-2*_z), (_z, 3, oo)) + assert b.probability(x > 3, evaluate=False).rewrite(Integral).dummy_eq(expected1) + + expected2 = Integral(2*exp(-2*_z), (_z, 0, 4)) + assert b.probability(x < 4, evaluate=False).rewrite(Integral).dummy_eq(expected2) + Y = Exponential('y', 2*rate) + assert coskewness(X, X, X) == skewness(X) + assert coskewness(X, Y + rate*X, Y + 2*rate*X) == \ + 4/(sqrt(1 + 1/(4*rate**2))*sqrt(4 + 1/(4*rate**2))) + assert coskewness(X + 2*Y, Y + X, Y + 2*X, X > 3) == \ + sqrt(170)*Rational(9, 85) + +def test_exponential_power(): + mu = Symbol('mu') + z = Symbol('z') + alpha = Symbol('alpha', positive=True) + beta = Symbol('beta', positive=True) + + X = ExponentialPower('x', mu, alpha, beta) + + assert density(X)(z) == beta*exp(-(Abs(mu - z)/alpha) + ** beta)/(2*alpha*gamma(1/beta)) + assert cdf(X)(z) == S.Half + lowergamma(1/beta, + (Abs(mu - z)/alpha)**beta)*sign(-mu + z)/\ + (2*gamma(1/beta)) + + +def test_f_distribution(): + d1 = Symbol("d1", positive=True) + d2 = Symbol("d2", positive=True) + + X = FDistribution("x", d1, d2) + + assert density(X)(x) == (d2**(d2/2)*sqrt((d1*x)**d1*(d1*x + d2)**(-d1 - d2)) + /(x*beta(d1/2, d2/2))) + + raises(NotImplementedError, lambda: moment_generating_function(X)) + d1 = Symbol("d1", nonpositive=True) + raises(ValueError, lambda: FDistribution('x', d1, d1)) + + d1 = Symbol("d1", positive=True, integer=False) + raises(ValueError, lambda: FDistribution('x', d1, d1)) + + d1 = Symbol("d1", positive=True) + d2 = Symbol("d2", nonpositive=True) + raises(ValueError, lambda: FDistribution('x', d1, d2)) + + d2 = Symbol("d2", positive=True, integer=False) + raises(ValueError, lambda: FDistribution('x', d1, d2)) + + +def test_fisher_z(): + d1 = Symbol("d1", positive=True) + d2 = Symbol("d2", positive=True) + + X = FisherZ("x", d1, d2) + assert density(X)(x) == (2*d1**(d1/2)*d2**(d2/2)*(d1*exp(2*x) + d2) + **(-d1/2 - d2/2)*exp(d1*x)/beta(d1/2, d2/2)) + +def test_frechet(): + a = Symbol("a", positive=True) + s = Symbol("s", positive=True) + m = Symbol("m", real=True) + + X = Frechet("x", a, s=s, m=m) + assert density(X)(x) == a*((x - m)/s)**(-a - 1)*exp(-((x - m)/s)**(-a))/s + assert cdf(X)(x) == Piecewise((exp(-((-m + x)/s)**(-a)), m <= x), (0, True)) + +@slow +def test_gamma(): + k = Symbol("k", positive=True) + theta = Symbol("theta", positive=True) + + X = Gamma('x', k, theta) + + # Tests characteristic function + assert characteristic_function(X)(x) == ((-I*theta*x + 1)**(-k)) + + assert density(X)(x) == x**(k - 1)*theta**(-k)*exp(-x/theta)/gamma(k) + assert cdf(X, meijerg=True)(z) == Piecewise( + (-k*lowergamma(k, 0)/gamma(k + 1) + + k*lowergamma(k, z/theta)/gamma(k + 1), z >= 0), + (0, True)) + + # assert simplify(variance(X)) == k*theta**2 # handled numerically below + assert E(X) == moment(X, 1) + + k, theta = symbols('k theta', positive=True) + X = Gamma('x', k, theta) + assert E(X) == k*theta + assert variance(X) == k*theta**2 + assert skewness(X).expand() == 2/sqrt(k) + assert kurtosis(X).expand() == 3 + 6/k + + Y = Gamma('y', 2*k, 3*theta) + assert coskewness(X, theta*X + Y, k*X + Y).simplify() == \ + 2*531441**(-k)*sqrt(k)*theta*(3*3**(12*k) - 2*531441**k) \ + /(sqrt(k**2 + 18)*sqrt(theta**2 + 18)) + +def test_gamma_inverse(): + a = Symbol("a", positive=True) + b = Symbol("b", positive=True) + X = GammaInverse("x", a, b) + assert density(X)(x) == x**(-a - 1)*b**a*exp(-b/x)/gamma(a) + assert cdf(X)(x) == Piecewise((uppergamma(a, b/x)/gamma(a), x > 0), (0, True)) + assert characteristic_function(X)(x) == 2 * (-I*b*x)**(a/2) \ + * besselk(a, 2*sqrt(b)*sqrt(-I*x))/gamma(a) + raises(NotImplementedError, lambda: moment_generating_function(X)) + +def test_gompertz(): + b = Symbol("b", positive=True) + eta = Symbol("eta", positive=True) + + X = Gompertz("x", b, eta) + + assert density(X)(x) == b*eta*exp(eta)*exp(b*x)*exp(-eta*exp(b*x)) + assert cdf(X)(x) == 1 - exp(eta)*exp(-eta*exp(b*x)) + assert diff(cdf(X)(x), x) == density(X)(x) + + +def test_gumbel(): + beta = Symbol("beta", positive=True) + mu = Symbol("mu") + x = Symbol("x") + y = Symbol("y") + X = Gumbel("x", beta, mu) + Y = Gumbel("y", beta, mu, minimum=True) + assert density(X)(x).expand() == \ + exp(mu/beta)*exp(-x/beta)*exp(-exp(mu/beta)*exp(-x/beta))/beta + assert density(Y)(y).expand() == \ + exp(-mu/beta)*exp(y/beta)*exp(-exp(-mu/beta)*exp(y/beta))/beta + assert cdf(X)(x).expand() == \ + exp(-exp(mu/beta)*exp(-x/beta)) + assert characteristic_function(X)(x) == exp(I*mu*x)*gamma(-I*beta*x + 1) + +def test_kumaraswamy(): + a = Symbol("a", positive=True) + b = Symbol("b", positive=True) + + X = Kumaraswamy("x", a, b) + assert density(X)(x) == x**(a - 1)*a*b*(-x**a + 1)**(b - 1) + assert cdf(X)(x) == Piecewise((0, x < 0), + (-(-x**a + 1)**b + 1, x <= 1), + (1, True)) + + +def test_laplace(): + mu = Symbol("mu") + b = Symbol("b", positive=True) + + X = Laplace('x', mu, b) + + #Tests characteristic_function + assert characteristic_function(X)(x) == (exp(I*mu*x)/(b**2*x**2 + 1)) + + assert density(X)(x) == exp(-Abs(x - mu)/b)/(2*b) + assert cdf(X)(x) == Piecewise((exp((-mu + x)/b)/2, mu > x), + (-exp((mu - x)/b)/2 + 1, True)) + X = Laplace('x', [1, 2], [[1, 0], [0, 1]]) + assert isinstance(pspace(X).distribution, MultivariateLaplaceDistribution) + +def test_levy(): + mu = Symbol("mu", real=True) + c = Symbol("c", positive=True) + + X = Levy('x', mu, c) + assert X.pspace.domain.set == Interval(mu, oo) + assert density(X)(x) == sqrt(c/(2*pi))*exp(-c/(2*(x - mu)))/((x - mu)**(S.One + S.Half)) + assert cdf(X)(x) == erfc(sqrt(c/(2*(x - mu)))) + + raises(NotImplementedError, lambda: moment_generating_function(X)) + mu = Symbol("mu", real=False) + raises(ValueError, lambda: Levy('x',mu,c)) + + c = Symbol("c", nonpositive=True) + raises(ValueError, lambda: Levy('x',mu,c)) + + mu = Symbol("mu", real=True) + raises(ValueError, lambda: Levy('x',mu,c)) + +def test_logcauchy(): + mu = Symbol("mu", positive=True) + sigma = Symbol("sigma", positive=True) + + X = LogCauchy("x", mu, sigma) + + assert density(X)(x) == sigma/(x*pi*(sigma**2 + (-mu + log(x))**2)) + assert cdf(X)(x) == atan((log(x) - mu)/sigma)/pi + S.Half + + +def test_logistic(): + mu = Symbol("mu", real=True) + s = Symbol("s", positive=True) + p = Symbol("p", positive=True) + + X = Logistic('x', mu, s) + + #Tests characteristics_function + assert characteristic_function(X)(x) == \ + (Piecewise((pi*s*x*exp(I*mu*x)/sinh(pi*s*x), Ne(x, 0)), (1, True))) + + assert density(X)(x) == exp((-x + mu)/s)/(s*(exp((-x + mu)/s) + 1)**2) + assert cdf(X)(x) == 1/(exp((mu - x)/s) + 1) + assert quantile(X)(p) == mu - s*log(-S.One + 1/p) + +def test_loglogistic(): + a, b = symbols('a b') + assert LogLogistic('x', a, b) + + a = Symbol('a', negative=True) + b = Symbol('b', positive=True) + raises(ValueError, lambda: LogLogistic('x', a, b)) + + a = Symbol('a', positive=True) + b = Symbol('b', negative=True) + raises(ValueError, lambda: LogLogistic('x', a, b)) + + a, b, z, p = symbols('a b z p', positive=True) + X = LogLogistic('x', a, b) + assert density(X)(z) == b*(z/a)**(b - 1)/(a*((z/a)**b + 1)**2) + assert cdf(X)(z) == 1/(1 + (z/a)**(-b)) + assert quantile(X)(p) == a*(p/(1 - p))**(1/b) + + # Expectation + assert E(X) == Piecewise((S.NaN, b <= 1), (pi*a/(b*sin(pi/b)), True)) + b = symbols('b', prime=True) # b > 1 + X = LogLogistic('x', a, b) + assert E(X) == pi*a/(b*sin(pi/b)) + X = LogLogistic('x', 1, 2) + assert median(X) == FiniteSet(1) + +def test_logitnormal(): + mu = Symbol('mu', real=True) + s = Symbol('s', positive=True) + X = LogitNormal('x', mu, s) + x = Symbol('x') + + assert density(X)(x) == sqrt(2)*exp(-(-mu + log(x/(1 - x)))**2/(2*s**2))/(2*sqrt(pi)*s*x*(1 - x)) + assert cdf(X)(x) == erf(sqrt(2)*(-mu + log(x/(1 - x)))/(2*s))/2 + S(1)/2 + +def test_lognormal(): + mean = Symbol('mu', real=True) + std = Symbol('sigma', positive=True) + X = LogNormal('x', mean, std) + # The sympy integrator can't do this too well + #assert E(X) == exp(mean+std**2/2) + #assert variance(X) == (exp(std**2)-1) * exp(2*mean + std**2) + + # The sympy integrator can't do this too well + #assert E(X) == + raises(NotImplementedError, lambda: moment_generating_function(X)) + mu = Symbol("mu", real=True) + sigma = Symbol("sigma", positive=True) + + X = LogNormal('x', mu, sigma) + assert density(X)(x) == (sqrt(2)*exp(-(-mu + log(x))**2 + /(2*sigma**2))/(2*x*sqrt(pi)*sigma)) + # Tests cdf + assert cdf(X)(x) == Piecewise( + (erf(sqrt(2)*(-mu + log(x))/(2*sigma))/2 + + S(1)/2, x > 0), (0, True)) + + X = LogNormal('x', 0, 1) # Mean 0, standard deviation 1 + assert density(X)(x) == sqrt(2)*exp(-log(x)**2/2)/(2*x*sqrt(pi)) + + +def test_Lomax(): + a, l = symbols('a, l', negative=True) + raises(ValueError, lambda: Lomax('X', a, l)) + a, l = symbols('a, l', real=False) + raises(ValueError, lambda: Lomax('X', a, l)) + + a, l = symbols('a, l', positive=True) + X = Lomax('X', a, l) + assert X.pspace.domain.set == Interval(0, oo) + assert density(X)(x) == a*(1 + x/l)**(-a - 1)/l + assert cdf(X)(x) == Piecewise((1 - (1 + x/l)**(-a), x >= 0), (0, True)) + a = 3 + X = Lomax('X', a, l) + assert E(X) == l/2 + assert median(X) == FiniteSet(l*(-1 + 2**Rational(1, 3))) + assert variance(X) == 3*l**2/4 + + +def test_maxwell(): + a = Symbol("a", positive=True) + + X = Maxwell('x', a) + + assert density(X)(x) == (sqrt(2)*x**2*exp(-x**2/(2*a**2))/ + (sqrt(pi)*a**3)) + assert E(X) == 2*sqrt(2)*a/sqrt(pi) + assert variance(X) == -8*a**2/pi + 3*a**2 + assert cdf(X)(x) == erf(sqrt(2)*x/(2*a)) - sqrt(2)*x*exp(-x**2/(2*a**2))/(sqrt(pi)*a) + assert diff(cdf(X)(x), x) == density(X)(x) + + +@slow +def test_Moyal(): + mu = Symbol('mu',real=False) + sigma = Symbol('sigma', positive=True) + raises(ValueError, lambda: Moyal('M',mu, sigma)) + + mu = Symbol('mu', real=True) + sigma = Symbol('sigma', negative=True) + raises(ValueError, lambda: Moyal('M',mu, sigma)) + + sigma = Symbol('sigma', positive=True) + M = Moyal('M', mu, sigma) + assert density(M)(z) == sqrt(2)*exp(-exp((mu - z)/sigma)/2 + - (-mu + z)/(2*sigma))/(2*sqrt(pi)*sigma) + assert cdf(M)(z).simplify() == 1 - erf(sqrt(2)*exp((mu - z)/(2*sigma))/2) + assert characteristic_function(M)(z) == 2**(-I*sigma*z)*exp(I*mu*z) \ + *gamma(-I*sigma*z + Rational(1, 2))/sqrt(pi) + assert E(M) == mu + EulerGamma*sigma + sigma*log(2) + assert moment_generating_function(M)(z) == 2**(-sigma*z)*exp(mu*z) \ + *gamma(-sigma*z + Rational(1, 2))/sqrt(pi) + + +def test_nakagami(): + mu = Symbol("mu", positive=True) + omega = Symbol("omega", positive=True) + + X = Nakagami('x', mu, omega) + assert density(X)(x) == (2*x**(2*mu - 1)*mu**mu*omega**(-mu) + *exp(-x**2*mu/omega)/gamma(mu)) + assert simplify(E(X)) == (sqrt(mu)*sqrt(omega) + *gamma(mu + S.Half)/gamma(mu + 1)) + assert simplify(variance(X)) == ( + omega - omega*gamma(mu + S.Half)**2/(gamma(mu)*gamma(mu + 1))) + assert cdf(X)(x) == Piecewise( + (lowergamma(mu, mu*x**2/omega)/gamma(mu), x > 0), + (0, True)) + X = Nakagami('x', 1, 1) + assert median(X) == FiniteSet(sqrt(log(2))) + +def test_gaussian_inverse(): + # test for symbolic parameters + a, b = symbols('a b') + assert GaussianInverse('x', a, b) + + # Inverse Gaussian distribution is also known as Wald distribution + # `GaussianInverse` can also be referred by the name `Wald` + a, b, z = symbols('a b z') + X = Wald('x', a, b) + assert density(X)(z) == sqrt(2)*sqrt(b/z**3)*exp(-b*(-a + z)**2/(2*a**2*z))/(2*sqrt(pi)) + + a, b = symbols('a b', positive=True) + z = Symbol('z', positive=True) + + X = GaussianInverse('x', a, b) + assert density(X)(z) == sqrt(2)*sqrt(b)*sqrt(z**(-3))*exp(-b*(-a + z)**2/(2*a**2*z))/(2*sqrt(pi)) + assert E(X) == a + assert variance(X).expand() == a**3/b + assert cdf(X)(z) == (S.Half - erf(sqrt(2)*sqrt(b)*(1 + z/a)/(2*sqrt(z)))/2)*exp(2*b/a) +\ + erf(sqrt(2)*sqrt(b)*(-1 + z/a)/(2*sqrt(z)))/2 + S.Half + + a = symbols('a', nonpositive=True) + raises(ValueError, lambda: GaussianInverse('x', a, b)) + + a = symbols('a', positive=True) + b = symbols('b', nonpositive=True) + raises(ValueError, lambda: GaussianInverse('x', a, b)) + +def test_pareto(): + xm, beta = symbols('xm beta', positive=True) + alpha = beta + 5 + X = Pareto('x', xm, alpha) + + dens = density(X) + + #Tests cdf function + assert cdf(X)(x) == \ + Piecewise((-x**(-beta - 5)*xm**(beta + 5) + 1, x >= xm), (0, True)) + + #Tests characteristic_function + assert characteristic_function(X)(x) == \ + ((-I*x*xm)**(beta + 5)*(beta + 5)*uppergamma(-beta - 5, -I*x*xm)) + + assert dens(x) == x**(-(alpha + 1))*xm**(alpha)*(alpha) + + assert simplify(E(X)) == alpha*xm/(alpha-1) + + # computation of taylor series for MGF still too slow + #assert simplify(variance(X)) == xm**2*alpha / ((alpha-1)**2*(alpha-2)) + + +def test_pareto_numeric(): + xm, beta = 3, 2 + alpha = beta + 5 + X = Pareto('x', xm, alpha) + + assert E(X) == alpha*xm/S(alpha - 1) + assert variance(X) == xm**2*alpha / S((alpha - 1)**2*(alpha - 2)) + assert median(X) == FiniteSet(3*2**Rational(1, 7)) + # Skewness tests too slow. Try shortcutting function? + + +def test_PowerFunction(): + alpha = Symbol("alpha", nonpositive=True) + a, b = symbols('a, b', real=True) + raises (ValueError, lambda: PowerFunction('x', alpha, a, b)) + + a, b = symbols('a, b', real=False) + raises (ValueError, lambda: PowerFunction('x', alpha, a, b)) + + alpha = Symbol("alpha", positive=True) + a, b = symbols('a, b', real=True) + raises (ValueError, lambda: PowerFunction('x', alpha, 5, 2)) + + X = PowerFunction('X', 2, a, b) + assert density(X)(z) == (-2*a + 2*z)/(-a + b)**2 + assert cdf(X)(z) == Piecewise((a**2/(a**2 - 2*a*b + b**2) - + 2*a*z/(a**2 - 2*a*b + b**2) + z**2/(a**2 - 2*a*b + b**2), a <= z), (0, True)) + + X = PowerFunction('X', 2, 0, 1) + assert density(X)(z) == 2*z + assert cdf(X)(z) == Piecewise((z**2, z >= 0), (0,True)) + assert E(X) == Rational(2,3) + assert P(X < 0) == 0 + assert P(X < 1) == 1 + assert median(X) == FiniteSet(1/sqrt(2)) + +def test_raised_cosine(): + mu = Symbol("mu", real=True) + s = Symbol("s", positive=True) + + X = RaisedCosine("x", mu, s) + + assert pspace(X).domain.set == Interval(mu - s, mu + s) + #Tests characteristics_function + assert characteristic_function(X)(x) == \ + Piecewise((exp(-I*pi*mu/s)/2, Eq(x, -pi/s)), (exp(I*pi*mu/s)/2, Eq(x, pi/s)), (pi**2*exp(I*mu*x)*sin(s*x)/(s*x*(-s**2*x**2 + pi**2)), True)) + + assert density(X)(x) == (Piecewise(((cos(pi*(x - mu)/s) + 1)/(2*s), + And(x <= mu + s, mu - s <= x)), (0, True))) + + +def test_rayleigh(): + sigma = Symbol("sigma", positive=True) + + X = Rayleigh('x', sigma) + + #Tests characteristic_function + assert characteristic_function(X)(x) == (-sqrt(2)*sqrt(pi)*sigma*x*(erfi(sqrt(2)*sigma*x/2) - I)*exp(-sigma**2*x**2/2)/2 + 1) + + assert density(X)(x) == x*exp(-x**2/(2*sigma**2))/sigma**2 + assert E(X) == sqrt(2)*sqrt(pi)*sigma/2 + assert variance(X) == -pi*sigma**2/2 + 2*sigma**2 + assert cdf(X)(x) == 1 - exp(-x**2/(2*sigma**2)) + assert diff(cdf(X)(x), x) == density(X)(x) + +def test_reciprocal(): + a = Symbol("a", real=True) + b = Symbol("b", real=True) + + X = Reciprocal('x', a, b) + assert density(X)(x) == 1/(x*(-log(a) + log(b))) + assert cdf(X)(x) == Piecewise((log(a)/(log(a) - log(b)) - log(x)/(log(a) - log(b)), a <= x), (0, True)) + X = Reciprocal('x', 5, 30) + + assert E(X) == 25/(log(30) - log(5)) + assert P(X < 4) == S.Zero + assert P(X < 20) == log(20) / (log(30) - log(5)) - log(5) / (log(30) - log(5)) + assert cdf(X)(10) == log(10) / (log(30) - log(5)) - log(5) / (log(30) - log(5)) + + a = symbols('a', nonpositive=True) + raises(ValueError, lambda: Reciprocal('x', a, b)) + + a = symbols('a', positive=True) + b = symbols('b', positive=True) + raises(ValueError, lambda: Reciprocal('x', a + b, a)) + +def test_shiftedgompertz(): + b = Symbol("b", positive=True) + eta = Symbol("eta", positive=True) + X = ShiftedGompertz("x", b, eta) + assert density(X)(x) == b*(eta*(1 - exp(-b*x)) + 1)*exp(-b*x)*exp(-eta*exp(-b*x)) + + +def test_studentt(): + nu = Symbol("nu", positive=True) + + X = StudentT('x', nu) + assert density(X)(x) == (1 + x**2/nu)**(-nu/2 - S.Half)/(sqrt(nu)*beta(S.Half, nu/2)) + assert cdf(X)(x) == S.Half + x*gamma(nu/2 + S.Half)*hyper((S.Half, nu/2 + S.Half), + (Rational(3, 2),), -x**2/nu)/(sqrt(pi)*sqrt(nu)*gamma(nu/2)) + raises(NotImplementedError, lambda: moment_generating_function(X)) + +def test_trapezoidal(): + a = Symbol("a", real=True) + b = Symbol("b", real=True) + c = Symbol("c", real=True) + d = Symbol("d", real=True) + + X = Trapezoidal('x', a, b, c, d) + assert density(X)(x) == Piecewise(((-2*a + 2*x)/((-a + b)*(-a - b + c + d)), (a <= x) & (x < b)), + (2/(-a - b + c + d), (b <= x) & (x < c)), + ((2*d - 2*x)/((-c + d)*(-a - b + c + d)), (c <= x) & (x <= d)), + (0, True)) + + X = Trapezoidal('x', 0, 1, 2, 3) + assert E(X) == Rational(3, 2) + assert variance(X) == Rational(5, 12) + assert P(X < 2) == Rational(3, 4) + assert median(X) == FiniteSet(Rational(3, 2)) + +def test_triangular(): + a = Symbol("a") + b = Symbol("b") + c = Symbol("c") + + X = Triangular('x', a, b, c) + assert pspace(X).domain.set == Interval(a, b) + assert str(density(X)(x)) == ("Piecewise(((-2*a + 2*x)/((-a + b)*(-a + c)), (a <= x) & (c > x)), " + "(2/(-a + b), Eq(c, x)), ((2*b - 2*x)/((-a + b)*(b - c)), (b >= x) & (c < x)), (0, True))") + + #Tests moment_generating_function + assert moment_generating_function(X)(x).expand() == \ + ((-2*(-a + b)*exp(c*x) + 2*(-a + c)*exp(b*x) + 2*(b - c)*exp(a*x))/(x**2*(-a + b)*(-a + c)*(b - c))).expand() + assert str(characteristic_function(X)(x)) == \ + '(2*(-a + b)*exp(I*c*x) - 2*(-a + c)*exp(I*b*x) - 2*(b - c)*exp(I*a*x))/(x**2*(-a + b)*(-a + c)*(b - c))' + +def test_quadratic_u(): + a = Symbol("a", real=True) + b = Symbol("b", real=True) + + X = QuadraticU("x", a, b) + Y = QuadraticU("x", 1, 2) + + assert pspace(X).domain.set == Interval(a, b) + # Tests _moment_generating_function + assert moment_generating_function(Y)(1) == -15*exp(2) + 27*exp(1) + assert moment_generating_function(Y)(2) == -9*exp(4)/2 + 21*exp(2)/2 + + assert characteristic_function(Y)(1) == 3*I*(-1 + 4*I)*exp(I*exp(2*I)) + assert density(X)(x) == (Piecewise((12*(x - a/2 - b/2)**2/(-a + b)**3, + And(x <= b, a <= x)), (0, True))) + + +def test_uniform(): + l = Symbol('l', real=True) + w = Symbol('w', positive=True) + X = Uniform('x', l, l + w) + + assert E(X) == l + w/2 + assert variance(X).expand() == w**2/12 + + # With numbers all is well + X = Uniform('x', 3, 5) + assert P(X < 3) == 0 and P(X > 5) == 0 + assert P(X < 4) == P(X > 4) == S.Half + assert median(X) == FiniteSet(4) + + z = Symbol('z') + p = density(X)(z) + assert p.subs(z, 3.7) == S.Half + assert p.subs(z, -1) == 0 + assert p.subs(z, 6) == 0 + + c = cdf(X) + assert c(2) == 0 and c(3) == 0 + assert c(Rational(7, 2)) == Rational(1, 4) + assert c(5) == 1 and c(6) == 1 + + +@XFAIL +@slow +def test_uniform_P(): + """ This stopped working because SingleContinuousPSpace.compute_density no + longer calls integrate on a DiracDelta but rather just solves directly. + integrate used to call UniformDistribution.expectation which special-cased + subsed out the Min and Max terms that Uniform produces + + I decided to regress on this class for general cleanliness (and I suspect + speed) of the algorithm. + """ + l = Symbol('l', real=True) + w = Symbol('w', positive=True) + X = Uniform('x', l, l + w) + assert P(X < l) == 0 and P(X > l + w) == 0 + + +def test_uniformsum(): + n = Symbol("n", integer=True) + _k = Dummy("k") + x = Symbol("x") + + X = UniformSum('x', n) + res = Sum((-1)**_k*(-_k + x)**(n - 1)*binomial(n, _k), (_k, 0, floor(x)))/factorial(n - 1) + assert density(X)(x).dummy_eq(res) + + #Tests set functions + assert X.pspace.domain.set == Interval(0, n) + + #Tests the characteristic_function + assert characteristic_function(X)(x) == (-I*(exp(I*x) - 1)/x)**n + + #Tests the moment_generating_function + assert moment_generating_function(X)(x) == ((exp(x) - 1)/x)**n + + +def test_von_mises(): + mu = Symbol("mu") + k = Symbol("k", positive=True) + + X = VonMises("x", mu, k) + assert density(X)(x) == exp(k*cos(x - mu))/(2*pi*besseli(0, k)) + + +def test_weibull(): + a, b = symbols('a b', positive=True) + # FIXME: simplify(E(X)) seems to hang without extended_positive=True + # On a Linux machine this had a rapid memory leak... + # a, b = symbols('a b', positive=True) + X = Weibull('x', a, b) + + assert E(X).expand() == a * gamma(1 + 1/b) + assert variance(X).expand() == (a**2 * gamma(1 + 2/b) - E(X)**2).expand() + assert simplify(skewness(X)) == (2*gamma(1 + 1/b)**3 - 3*gamma(1 + 1/b)*gamma(1 + 2/b) + gamma(1 + 3/b))/(-gamma(1 + 1/b)**2 + gamma(1 + 2/b))**Rational(3, 2) + assert simplify(kurtosis(X)) == (-3*gamma(1 + 1/b)**4 +\ + 6*gamma(1 + 1/b)**2*gamma(1 + 2/b) - 4*gamma(1 + 1/b)*gamma(1 + 3/b) + gamma(1 + 4/b))/(gamma(1 + 1/b)**2 - gamma(1 + 2/b))**2 + +def test_weibull_numeric(): + # Test for integers and rationals + a = 1 + bvals = [S.Half, 1, Rational(3, 2), 5] + for b in bvals: + X = Weibull('x', a, b) + assert simplify(E(X)) == expand_func(a * gamma(1 + 1/S(b))) + assert simplify(variance(X)) == simplify( + a**2 * gamma(1 + 2/S(b)) - E(X)**2) + # Not testing Skew... it's slow with int/frac values > 3/2 + + +def test_wignersemicircle(): + R = Symbol("R", positive=True) + + X = WignerSemicircle('x', R) + assert pspace(X).domain.set == Interval(-R, R) + assert density(X)(x) == 2*sqrt(-x**2 + R**2)/(pi*R**2) + assert E(X) == 0 + + + #Tests ChiNoncentralDistribution + assert characteristic_function(X)(x) == \ + Piecewise((2*besselj(1, R*x)/(R*x), Ne(x, 0)), (1, True)) + + +def test_input_value_assertions(): + a, b = symbols('a b') + p, q = symbols('p q', positive=True) + m, n = symbols('m n', positive=False, real=True) + + raises(ValueError, lambda: Normal('x', 3, 0)) + raises(ValueError, lambda: Normal('x', m, n)) + Normal('X', a, p) # No error raised + raises(ValueError, lambda: Exponential('x', m)) + Exponential('Ex', p) # No error raised + for fn in [Pareto, Weibull, Beta, Gamma]: + raises(ValueError, lambda: fn('x', m, p)) + raises(ValueError, lambda: fn('x', p, n)) + fn('x', p, q) # No error raised + + +def test_unevaluated(): + X = Normal('x', 0, 1) + k = Dummy('k') + expr1 = Integral(sqrt(2)*k*exp(-k**2/2)/(2*sqrt(pi)), (k, -oo, oo)) + expr2 = Integral(sqrt(2)*exp(-k**2/2)/(2*sqrt(pi)), (k, 0, oo)) + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + assert E(X, evaluate=False).rewrite(Integral).dummy_eq(expr1) + assert E(X + 1, evaluate=False).rewrite(Integral).dummy_eq(expr1 + 1) + assert P(X > 0, evaluate=False).rewrite(Integral).dummy_eq(expr2) + + assert P(X > 0, X**2 < 1) == S.Half + + +def test_probability_unevaluated(): + T = Normal('T', 30, 3) + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + assert type(P(T > 33, evaluate=False)) == Probability + + +def test_density_unevaluated(): + X = Normal('X', 0, 1) + Y = Normal('Y', 0, 2) + assert isinstance(density(X+Y, evaluate=False)(z), Integral) + + +def test_NormalDistribution(): + nd = NormalDistribution(0, 1) + x = Symbol('x') + assert nd.cdf(x) == erf(sqrt(2)*x/2)/2 + S.Half + assert nd.expectation(1, x) == 1 + assert nd.expectation(x, x) == 0 + assert nd.expectation(x**2, x) == 1 + #Test issue 10076 + a = SingleContinuousPSpace(x, NormalDistribution(2, 4)) + _z = Dummy('_z') + + expected1 = Integral(sqrt(2)*exp(-(_z - 2)**2/32)/(8*sqrt(pi)),(_z, -oo, 1)) + assert a.probability(x < 1, evaluate=False).dummy_eq(expected1) is True + + expected2 = Integral(sqrt(2)*exp(-(_z - 2)**2/32)/(8*sqrt(pi)),(_z, 1, oo)) + assert a.probability(x > 1, evaluate=False).dummy_eq(expected2) is True + + b = SingleContinuousPSpace(x, NormalDistribution(1, 9)) + + expected3 = Integral(sqrt(2)*exp(-(_z - 1)**2/162)/(18*sqrt(pi)),(_z, 6, oo)) + assert b.probability(x > 6, evaluate=False).dummy_eq(expected3) is True + + expected4 = Integral(sqrt(2)*exp(-(_z - 1)**2/162)/(18*sqrt(pi)),(_z, -oo, 6)) + assert b.probability(x < 6, evaluate=False).dummy_eq(expected4) is True + + +def test_random_parameters(): + mu = Normal('mu', 2, 3) + meas = Normal('T', mu, 1) + assert density(meas, evaluate=False)(z) + assert isinstance(pspace(meas), CompoundPSpace) + X = Normal('x', [1, 2], [[1, 0], [0, 1]]) + assert isinstance(pspace(X).distribution, MultivariateNormalDistribution) + assert density(meas)(z).simplify() == sqrt(5)*exp(-z**2/20 + z/5 - S(1)/5)/(10*sqrt(pi)) + + +def test_random_parameters_given(): + mu = Normal('mu', 2, 3) + meas = Normal('T', mu, 1) + assert given(meas, Eq(mu, 5)) == Normal('T', 5, 1) + + +def test_conjugate_priors(): + mu = Normal('mu', 2, 3) + x = Normal('x', mu, 1) + assert isinstance(simplify(density(mu, Eq(x, y), evaluate=False)(z)), + Mul) + + +def test_difficult_univariate(): + """ Since using solve in place of deltaintegrate we're able to perform + substantially more complex density computations on single continuous random + variables """ + x = Normal('x', 0, 1) + assert density(x**3) + assert density(exp(x**2)) + assert density(log(x)) + + +def test_issue_10003(): + X = Exponential('x', 3) + G = Gamma('g', 1, 2) + assert P(X < -1) is S.Zero + assert P(G < -1) is S.Zero + + +def test_precomputed_cdf(): + x = symbols("x", real=True) + mu = symbols("mu", real=True) + sigma, xm, alpha = symbols("sigma xm alpha", positive=True) + n = symbols("n", integer=True, positive=True) + distribs = [ + Normal("X", mu, sigma), + Pareto("P", xm, alpha), + ChiSquared("C", n), + Exponential("E", sigma), + # LogNormal("L", mu, sigma), + ] + for X in distribs: + compdiff = cdf(X)(x) - simplify(X.pspace.density.compute_cdf()(x)) + compdiff = simplify(compdiff.rewrite(erfc)) + assert compdiff == 0 + + +@slow +def test_precomputed_characteristic_functions(): + import mpmath + + def test_cf(dist, support_lower_limit, support_upper_limit): + pdf = density(dist) + t = Symbol('t') + + # first function is the hardcoded CF of the distribution + cf1 = lambdify([t], characteristic_function(dist)(t), 'mpmath') + + # second function is the Fourier transform of the density function + f = lambdify([x, t], pdf(x)*exp(I*x*t), 'mpmath') + cf2 = lambda t: mpmath.quad(lambda x: f(x, t), [support_lower_limit, support_upper_limit], maxdegree=10) + + # compare the two functions at various points + for test_point in [2, 5, 8, 11]: + n1 = cf1(test_point) + n2 = cf2(test_point) + + assert abs(re(n1) - re(n2)) < 1e-12 + assert abs(im(n1) - im(n2)) < 1e-12 + + test_cf(Beta('b', 1, 2), 0, 1) + test_cf(Chi('c', 3), 0, mpmath.inf) + test_cf(ChiSquared('c', 2), 0, mpmath.inf) + test_cf(Exponential('e', 6), 0, mpmath.inf) + test_cf(Logistic('l', 1, 2), -mpmath.inf, mpmath.inf) + test_cf(Normal('n', -1, 5), -mpmath.inf, mpmath.inf) + test_cf(RaisedCosine('r', 3, 1), 2, 4) + test_cf(Rayleigh('r', 0.5), 0, mpmath.inf) + test_cf(Uniform('u', -1, 1), -1, 1) + test_cf(WignerSemicircle('w', 3), -3, 3) + + +def test_long_precomputed_cdf(): + x = symbols("x", real=True) + distribs = [ + Arcsin("A", -5, 9), + Dagum("D", 4, 10, 3), + Erlang("E", 14, 5), + Frechet("F", 2, 6, -3), + Gamma("G", 2, 7), + GammaInverse("GI", 3, 5), + Kumaraswamy("K", 6, 8), + Laplace("LA", -5, 4), + Logistic("L", -6, 7), + Nakagami("N", 2, 7), + StudentT("S", 4) + ] + for distr in distribs: + for _ in range(5): + assert tn(diff(cdf(distr)(x), x), density(distr)(x), x, a=0, b=0, c=1, d=0) + + US = UniformSum("US", 5) + pdf01 = density(US)(x).subs(floor(x), 0).doit() # pdf on (0, 1) + cdf01 = cdf(US, evaluate=False)(x).subs(floor(x), 0).doit() # cdf on (0, 1) + assert tn(diff(cdf01, x), pdf01, x, a=0, b=0, c=1, d=0) + + +def test_issue_13324(): + X = Uniform('X', 0, 1) + assert E(X, X > S.Half) == Rational(3, 4) + assert E(X, X > 0) == S.Half + +def test_issue_20756(): + X = Uniform('X', -1, +1) + Y = Uniform('Y', -1, +1) + assert E(X * Y) == S.Zero + assert E(X * ((Y + 1) - 1)) == S.Zero + assert E(Y * (X*(X + 1) - X*X)) == S.Zero + +def test_FiniteSet_prob(): + E = Exponential('E', 3) + N = Normal('N', 5, 7) + assert P(Eq(E, 1)) is S.Zero + assert P(Eq(N, 2)) is S.Zero + assert P(Eq(N, x)) is S.Zero + +def test_prob_neq(): + E = Exponential('E', 4) + X = ChiSquared('X', 4) + assert P(Ne(E, 2)) == 1 + assert P(Ne(X, 4)) == 1 + assert P(Ne(X, 4)) == 1 + assert P(Ne(X, 5)) == 1 + assert P(Ne(E, x)) == 1 + +def test_union(): + N = Normal('N', 3, 2) + assert simplify(P(N**2 - N > 2)) == \ + -erf(sqrt(2))/2 - erfc(sqrt(2)/4)/2 + Rational(3, 2) + assert simplify(P(N**2 - 4 > 0)) == \ + -erf(5*sqrt(2)/4)/2 - erfc(sqrt(2)/4)/2 + Rational(3, 2) + +def test_Or(): + N = Normal('N', 0, 1) + assert simplify(P(Or(N > 2, N < 1))) == \ + -erf(sqrt(2))/2 - erfc(sqrt(2)/2)/2 + Rational(3, 2) + assert P(Or(N < 0, N < 1)) == P(N < 1) + assert P(Or(N > 0, N < 0)) == 1 + + +def test_conditional_eq(): + E = Exponential('E', 1) + assert P(Eq(E, 1), Eq(E, 1)) == 1 + assert P(Eq(E, 1), Eq(E, 2)) == 0 + assert P(E > 1, Eq(E, 2)) == 1 + assert P(E < 1, Eq(E, 2)) == 0 + +def test_ContinuousDistributionHandmade(): + x = Symbol('x') + z = Dummy('z') + dens = Lambda(x, Piecewise((S.Half, (0<=x)&(x<1)), (0, (x>=1)&(x<2)), + (S.Half, (x>=2)&(x<3)), (0, True))) + dens = ContinuousDistributionHandmade(dens, set=Interval(0, 3)) + space = SingleContinuousPSpace(z, dens) + assert dens.pdf == Lambda(x, Piecewise((S(1)/2, (x >= 0) & (x < 1)), + (0, (x >= 1) & (x < 2)), (S(1)/2, (x >= 2) & (x < 3)), (0, True))) + assert median(space.value) == Interval(1, 2) + assert E(space.value) == Rational(3, 2) + assert variance(space.value) == Rational(13, 12) + + +def test_issue_16318(): + # test compute_expectation function of the SingleContinuousDomain + N = SingleContinuousDomain(x, Interval(0, 1)) + raises(ValueError, lambda: SingleContinuousDomain.compute_expectation(N, x+1, {x, y})) + +def test_compute_density(): + X = Normal('X', 0, Symbol("sigma")**2) + raises(ValueError, lambda: density(X**5 + X)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_discrete_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_discrete_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..39650a1a08e42840aaf8b06c1eb6e60c92a57f23 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_discrete_rv.py @@ -0,0 +1,312 @@ +from sympy.concrete.summations import Sum +from sympy.core.numbers import (I, Rational, oo, pi) +from sympy.core.singleton import S +from sympy.core.symbol import Symbol +from sympy.functions.elementary.complexes import (im, re) +from sympy.functions.elementary.exponential import log +from sympy.functions.elementary.integers import floor +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.bessel import besseli +from sympy.functions.special.beta_functions import beta +from sympy.functions.special.zeta_functions import zeta +from sympy.sets.sets import FiniteSet +from sympy.simplify.simplify import simplify +from sympy.utilities.lambdify import lambdify +from sympy.core.relational import Eq, Ne +from sympy.functions.elementary.exponential import exp +from sympy.logic.boolalg import Or +from sympy.sets.fancysets import Range +from sympy.stats import (P, E, variance, density, characteristic_function, + where, moment_generating_function, skewness, cdf, + kurtosis, coskewness) +from sympy.stats.drv_types import (PoissonDistribution, GeometricDistribution, + FlorySchulz, Poisson, Geometric, Hermite, Logarithmic, + NegativeBinomial, Skellam, YuleSimon, Zeta, + DiscreteRV) +from sympy.testing.pytest import slow, nocache_fail, raises, skip +from sympy.stats.symbolic_probability import Expectation +from sympy.functions.combinatorial.factorials import FallingFactorial + +x = Symbol('x') + + +def test_PoissonDistribution(): + l = 3 + p = PoissonDistribution(l) + assert abs(p.cdf(10).evalf() - 1) < .001 + assert abs(p.cdf(10.4).evalf() - 1) < .001 + assert p.expectation(x, x) == l + assert p.expectation(x**2, x) - p.expectation(x, x)**2 == l + + +def test_Poisson(): + l = 3 + x = Poisson('x', l) + assert E(x) == l + assert E(2*x) == 2*l + assert variance(x) == l + assert density(x) == PoissonDistribution(l) + assert isinstance(E(x, evaluate=False), Expectation) + assert isinstance(E(2*x, evaluate=False), Expectation) + # issue 8248 + assert x.pspace.compute_expectation(1) == 1 + # issue 27344 + try: + import numpy as np + except ImportError: + skip("numpy not installed") + y = Poisson('y', np.float64(4.72544290380919e-11)) + assert E(y) == 4.72544290380919e-11 + y = Poisson('y', np.float64(4.725442903809197e-11)) + assert E(y) == 4.725442903809197e-11 + l2 = 5 + z = Poisson('z', l2) + assert E(z) == l2 + assert E(FallingFactorial(z, 3)) == l2**3 + assert E(z**2) == l2 + l2**2 + + +def test_FlorySchulz(): + a = Symbol("a") + z = Symbol("z") + x = FlorySchulz('x', a) + assert E(x) == (2 - a)/a + assert (variance(x) - 2*(1 - a)/a**2).simplify() == S(0) + assert density(x)(z) == a**2*z*(1 - a)**(z - 1) + + +@slow +def test_GeometricDistribution(): + p = S.One / 5 + d = GeometricDistribution(p) + assert d.expectation(x, x) == 1/p + assert d.expectation(x**2, x) - d.expectation(x, x)**2 == (1-p)/p**2 + assert abs(d.cdf(20000).evalf() - 1) < .001 + assert abs(d.cdf(20000.8).evalf() - 1) < .001 + G = Geometric('G', p=S(1)/4) + assert cdf(G)(S(7)/2) == P(G <= S(7)/2) + + X = Geometric('X', Rational(1, 5)) + Y = Geometric('Y', Rational(3, 10)) + assert coskewness(X, X + Y, X + 2*Y).simplify() == sqrt(230)*Rational(81, 1150) + + +def test_Hermite(): + a1 = Symbol("a1", positive=True) + a2 = Symbol("a2", negative=True) + raises(ValueError, lambda: Hermite("H", a1, a2)) + + a1 = Symbol("a1", negative=True) + a2 = Symbol("a2", positive=True) + raises(ValueError, lambda: Hermite("H", a1, a2)) + + a1 = Symbol("a1", positive=True) + x = Symbol("x") + H = Hermite("H", a1, a2) + assert moment_generating_function(H)(x) == exp(a1*(exp(x) - 1) + + a2*(exp(2*x) - 1)) + assert characteristic_function(H)(x) == exp(a1*(exp(I*x) - 1) + + a2*(exp(2*I*x) - 1)) + assert E(H) == a1 + 2*a2 + + H = Hermite("H", a1=5, a2=4) + assert density(H)(2) == 33*exp(-9)/2 + assert E(H) == 13 + assert variance(H) == 21 + assert kurtosis(H) == Rational(464,147) + assert skewness(H) == 37*sqrt(21)/441 + +def test_Logarithmic(): + p = S.Half + x = Logarithmic('x', p) + assert E(x) == -p / ((1 - p) * log(1 - p)) + assert variance(x) == -1/log(2)**2 + 2/log(2) + assert E(2*x**2 + 3*x + 4) == 4 + 7 / log(2) + assert isinstance(E(x, evaluate=False), Expectation) + + +@nocache_fail +def test_negative_binomial(): + r = 5 + p = S.One / 3 + x = NegativeBinomial('x', r, p) + assert E(x) == r * (1 - p) / p + # This hangs when run with the cache disabled: + assert variance(x) == r * (1 - p) / p**2 + assert E(x**5 + 2*x + 3) == E(x**5) + 2*E(x) + 3 == Rational(796473, 1) + assert isinstance(E(x, evaluate=False), Expectation) + + +def test_skellam(): + mu1 = Symbol('mu1') + mu2 = Symbol('mu2') + z = Symbol('z') + X = Skellam('x', mu1, mu2) + + assert density(X)(z) == (mu1/mu2)**(z/2) * \ + exp(-mu1 - mu2)*besseli(z, 2*sqrt(mu1*mu2)) + assert skewness(X).expand() == mu1/(mu1*sqrt(mu1 + mu2) + mu2 * + sqrt(mu1 + mu2)) - mu2/(mu1*sqrt(mu1 + mu2) + mu2*sqrt(mu1 + mu2)) + assert variance(X).expand() == mu1 + mu2 + assert E(X) == mu1 - mu2 + assert characteristic_function(X)(z) == exp( + mu1*exp(I*z) - mu1 - mu2 + mu2*exp(-I*z)) + assert moment_generating_function(X)(z) == exp( + mu1*exp(z) - mu1 - mu2 + mu2*exp(-z)) + + +def test_yule_simon(): + from sympy.core.singleton import S + rho = S(3) + x = YuleSimon('x', rho) + assert simplify(E(x)) == rho / (rho - 1) + assert simplify(variance(x)) == rho**2 / ((rho - 1)**2 * (rho - 2)) + assert isinstance(E(x, evaluate=False), Expectation) + # To test the cdf function + assert cdf(x)(x) == Piecewise((-beta(floor(x), 4)*floor(x) + 1, x >= 1), (0, True)) + + +def test_zeta(): + s = S(5) + x = Zeta('x', s) + assert E(x) == zeta(s-1) / zeta(s) + assert simplify(variance(x)) == ( + zeta(s) * zeta(s-2) - zeta(s-1)**2) / zeta(s)**2 + + +def test_discrete_probability(): + X = Geometric('X', Rational(1, 5)) + Y = Poisson('Y', 4) + G = Geometric('e', x) + assert P(Eq(X, 3)) == Rational(16, 125) + assert P(X < 3) == Rational(9, 25) + assert P(X > 3) == Rational(64, 125) + assert P(X >= 3) == Rational(16, 25) + assert P(X <= 3) == Rational(61, 125) + assert P(Ne(X, 3)) == Rational(109, 125) + assert P(Eq(Y, 3)) == 32*exp(-4)/3 + assert P(Y < 3) == 13*exp(-4) + assert P(Y > 3).equals(32*(Rational(-71, 32) + 3*exp(4)/32)*exp(-4)/3) + assert P(Y >= 3).equals(32*(Rational(-39, 32) + 3*exp(4)/32)*exp(-4)/3) + assert P(Y <= 3) == 71*exp(-4)/3 + assert P(Ne(Y, 3)).equals( + 13*exp(-4) + 32*(Rational(-71, 32) + 3*exp(4)/32)*exp(-4)/3) + assert P(X < S.Infinity) is S.One + assert P(X > S.Infinity) is S.Zero + assert P(G < 3) == x*(2-x) + assert P(Eq(G, 3)) == x*(-x + 1)**2 + + +def test_DiscreteRV(): + p = S(1)/2 + x = Symbol('x', integer=True, positive=True) + pdf = p*(1 - p)**(x - 1) # pdf of Geometric Distribution + D = DiscreteRV(x, pdf, set=S.Naturals, check=True) + assert E(D) == E(Geometric('G', S(1)/2)) == 2 + assert P(D > 3) == S(1)/8 + assert D.pspace.domain.set == S.Naturals + raises(ValueError, lambda: DiscreteRV(x, x, FiniteSet(*range(4)), check=True)) + + # purposeful invalid pmf but it should not raise since check=False + # see test_drv_types.test_ContinuousRV for explanation + X = DiscreteRV(x, 1/x, S.Naturals) + assert P(X < 2) == 1 + assert E(X) == oo + +def test_precomputed_characteristic_functions(): + import mpmath + + def test_cf(dist, support_lower_limit, support_upper_limit): + pdf = density(dist) + t = S('t') + x = S('x') + + # first function is the hardcoded CF of the distribution + cf1 = lambdify([t], characteristic_function(dist)(t), 'mpmath') + + # second function is the Fourier transform of the density function + f = lambdify([x, t], pdf(x)*exp(I*x*t), 'mpmath') + cf2 = lambda t: mpmath.nsum(lambda x: f(x, t), [ + support_lower_limit, support_upper_limit], maxdegree=10) + + # compare the two functions at various points + for test_point in [2, 5, 8, 11]: + n1 = cf1(test_point) + n2 = cf2(test_point) + + assert abs(re(n1) - re(n2)) < 1e-12 + assert abs(im(n1) - im(n2)) < 1e-12 + + test_cf(Geometric('g', Rational(1, 3)), 1, mpmath.inf) + test_cf(Logarithmic('l', Rational(1, 5)), 1, mpmath.inf) + test_cf(NegativeBinomial('n', 5, Rational(1, 7)), 0, mpmath.inf) + test_cf(Poisson('p', 5), 0, mpmath.inf) + test_cf(YuleSimon('y', 5), 1, mpmath.inf) + test_cf(Zeta('z', 5), 1, mpmath.inf) + + +def test_moment_generating_functions(): + t = S('t') + + geometric_mgf = moment_generating_function(Geometric('g', S.Half))(t) + assert geometric_mgf.diff(t).subs(t, 0) == 2 + + logarithmic_mgf = moment_generating_function(Logarithmic('l', S.Half))(t) + assert logarithmic_mgf.diff(t).subs(t, 0) == 1/log(2) + + negative_binomial_mgf = moment_generating_function( + NegativeBinomial('n', 5, Rational(1, 3)))(t) + assert negative_binomial_mgf.diff(t).subs(t, 0) == Rational(10, 1) + + poisson_mgf = moment_generating_function(Poisson('p', 5))(t) + assert poisson_mgf.diff(t).subs(t, 0) == 5 + + skellam_mgf = moment_generating_function(Skellam('s', 1, 1))(t) + assert skellam_mgf.diff(t).subs( + t, 2) == (-exp(-2) + exp(2))*exp(-2 + exp(-2) + exp(2)) + + yule_simon_mgf = moment_generating_function(YuleSimon('y', 3))(t) + assert simplify(yule_simon_mgf.diff(t).subs(t, 0)) == Rational(3, 2) + + zeta_mgf = moment_generating_function(Zeta('z', 5))(t) + assert zeta_mgf.diff(t).subs(t, 0) == pi**4/(90*zeta(5)) + + +def test_Or(): + X = Geometric('X', S.Half) + assert P(Or(X < 3, X > 4)) == Rational(13, 16) + assert P(Or(X > 2, X > 1)) == P(X > 1) + assert P(Or(X >= 3, X < 3)) == 1 + + +def test_where(): + X = Geometric('X', Rational(1, 5)) + Y = Poisson('Y', 4) + assert where(X**2 > 4).set == Range(3, S.Infinity, 1) + assert where(X**2 >= 4).set == Range(2, S.Infinity, 1) + assert where(Y**2 < 9).set == Range(0, 3, 1) + assert where(Y**2 <= 9).set == Range(0, 4, 1) + + +def test_conditional(): + X = Geometric('X', Rational(2, 3)) + Y = Poisson('Y', 3) + assert P(X > 2, X > 3) == 1 + assert P(X > 3, X > 2) == Rational(1, 3) + assert P(Y > 2, Y < 2) == 0 + assert P(Eq(Y, 3), Y >= 0) == 9*exp(-3)/2 + assert P(Eq(Y, 3), Eq(Y, 2)) == 0 + assert P(X < 2, Eq(X, 2)) == 0 + assert P(X > 2, Eq(X, 3)) == 1 + + +def test_product_spaces(): + X1 = Geometric('X1', S.Half) + X2 = Geometric('X2', Rational(1, 3)) + assert str(P(X1 + X2 < 3).rewrite(Sum)) == ( + "Sum(Piecewise((1/(4*2**n), n >= -1), (0, True)), (n, -oo, -1))/3") + assert str(P(X1 + X2 > 3).rewrite(Sum)) == ( + 'Sum(Piecewise((2**(X2 - n - 2)*(2/3)**(X2 - 1)/6, ' + 'X2 - n <= 2), (0, True)), (X2, 1, oo), (n, 1, oo))') + assert P(Eq(X1 + X2, 3)) == Rational(1, 12) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_error_prop.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_error_prop.py new file mode 100644 index 0000000000000000000000000000000000000000..483fb4c36e202d744faeb355606ff9803a516873 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_error_prop.py @@ -0,0 +1,60 @@ +from sympy.core.function import Function +from sympy.core.symbol import symbols +from sympy.functions.elementary.exponential import exp +from sympy.stats.error_prop import variance_prop +from sympy.stats.symbolic_probability import (RandomSymbol, Variance, + Covariance) + + +def test_variance_prop(): + x, y, z = symbols('x y z') + phi, t = consts = symbols('phi t') + a = RandomSymbol(x) + var_x = Variance(a) + var_y = Variance(RandomSymbol(y)) + var_z = Variance(RandomSymbol(z)) + f = Function('f')(x) + cases = { + x + y: var_x + var_y, + a + y: var_x + var_y, + x + y + z: var_x + var_y + var_z, + 2*x: 4*var_x, + x*y: var_x*y**2 + var_y*x**2, + 1/x: var_x/x**4, + x/y: (var_x*y**2 + var_y*x**2)/y**4, + exp(x): var_x*exp(2*x), + exp(2*x): 4*var_x*exp(4*x), + exp(-x*t): t**2*var_x*exp(-2*t*x), + f: Variance(f), + } + for inp, out in cases.items(): + obs = variance_prop(inp, consts=consts) + assert out == obs + +def test_variance_prop_with_covar(): + x, y, z = symbols('x y z') + phi, t = consts = symbols('phi t') + a = RandomSymbol(x) + var_x = Variance(a) + b = RandomSymbol(y) + var_y = Variance(b) + c = RandomSymbol(z) + var_z = Variance(c) + covar_x_y = Covariance(a, b) + covar_x_z = Covariance(a, c) + covar_y_z = Covariance(b, c) + cases = { + x + y: var_x + var_y + 2*covar_x_y, + a + y: var_x + var_y + 2*covar_x_y, + x + y + z: var_x + var_y + var_z + \ + 2*covar_x_y + 2*covar_x_z + 2*covar_y_z, + 2*x: 4*var_x, + x*y: var_x*y**2 + var_y*x**2 + 2*covar_x_y/(x*y), + 1/x: var_x/x**4, + exp(x): var_x*exp(2*x), + exp(2*x): 4*var_x*exp(4*x), + exp(-x*t): t**2*var_x*exp(-2*t*x), + } + for inp, out in cases.items(): + obs = variance_prop(inp, consts=consts, include_covar=True) + assert out == obs diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_finite_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_finite_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..93bf0211a26ecc32d7f18c7e2d8236859857e445 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_finite_rv.py @@ -0,0 +1,509 @@ +from sympy.concrete.summations import Sum +from sympy.core.containers import (Dict, Tuple) +from sympy.core.function import Function +from sympy.core.numbers import (I, Rational, nan) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, Symbol, symbols) +from sympy.core.sympify import sympify +from sympy.functions.combinatorial.factorials import binomial +from sympy.functions.combinatorial.numbers import harmonic +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.elementary.trigonometric import cos +from sympy.functions.special.beta_functions import beta +from sympy.logic.boolalg import (And, Or) +from sympy.polys.polytools import cancel +from sympy.sets.sets import FiniteSet +from sympy.simplify.simplify import simplify +from sympy.matrices import Matrix +from sympy.stats import (DiscreteUniform, Die, Bernoulli, Coin, Binomial, BetaBinomial, + Hypergeometric, Rademacher, IdealSoliton, RobustSoliton, P, E, variance, + covariance, skewness, density, where, FiniteRV, pspace, cdf, + correlation, moment, cmoment, smoment, characteristic_function, + moment_generating_function, quantile, kurtosis, median, coskewness) +from sympy.stats.frv_types import DieDistribution, BinomialDistribution, \ + HypergeometricDistribution +from sympy.stats.rv import Density +from sympy.testing.pytest import raises + + +def BayesTest(A, B): + assert P(A, B) == P(And(A, B)) / P(B) + assert P(A, B) == P(B, A) * P(A) / P(B) + + +def test_discreteuniform(): + # Symbolic + a, b, c, t = symbols('a b c t') + X = DiscreteUniform('X', [a, b, c]) + + assert E(X) == (a + b + c)/3 + assert simplify(variance(X) + - ((a**2 + b**2 + c**2)/3 - (a/3 + b/3 + c/3)**2)) == 0 + assert P(Eq(X, a)) == P(Eq(X, b)) == P(Eq(X, c)) == S('1/3') + + Y = DiscreteUniform('Y', range(-5, 5)) + + # Numeric + assert E(Y) == S('-1/2') + assert variance(Y) == S('33/4') + assert median(Y) == FiniteSet(-1, 0) + + for x in range(-5, 5): + assert P(Eq(Y, x)) == S('1/10') + assert P(Y <= x) == S(x + 6)/10 + assert P(Y >= x) == S(5 - x)/10 + + assert dict(density(Die('D', 6)).items()) == \ + dict(density(DiscreteUniform('U', range(1, 7))).items()) + + assert characteristic_function(X)(t) == exp(I*a*t)/3 + exp(I*b*t)/3 + exp(I*c*t)/3 + assert moment_generating_function(X)(t) == exp(a*t)/3 + exp(b*t)/3 + exp(c*t)/3 + # issue 18611 + raises(ValueError, lambda: DiscreteUniform('Z', [a, a, a, b, b, c])) + +def test_dice(): + # TODO: Make iid method! + X, Y, Z = Die('X', 6), Die('Y', 6), Die('Z', 6) + a, b, t, p = symbols('a b t p') + + assert E(X) == 3 + S.Half + assert variance(X) == Rational(35, 12) + assert E(X + Y) == 7 + assert E(X + X) == 7 + assert E(a*X + b) == a*E(X) + b + assert variance(X + Y) == variance(X) + variance(Y) == cmoment(X + Y, 2) + assert variance(X + X) == 4 * variance(X) == cmoment(X + X, 2) + assert cmoment(X, 0) == 1 + assert cmoment(4*X, 3) == 64*cmoment(X, 3) + assert covariance(X, Y) is S.Zero + assert covariance(X, X + Y) == variance(X) + assert density(Eq(cos(X*S.Pi), 1))[True] == S.Half + assert correlation(X, Y) == 0 + assert correlation(X, Y) == correlation(Y, X) + assert smoment(X + Y, 3) == skewness(X + Y) + assert smoment(X + Y, 4) == kurtosis(X + Y) + assert smoment(X, 0) == 1 + assert P(X > 3) == S.Half + assert P(2*X > 6) == S.Half + assert P(X > Y) == Rational(5, 12) + assert P(Eq(X, Y)) == P(Eq(X, 1)) + + assert E(X, X > 3) == 5 == moment(X, 1, 0, X > 3) + assert E(X, Y > 3) == E(X) == moment(X, 1, 0, Y > 3) + assert E(X + Y, Eq(X, Y)) == E(2*X) + assert moment(X, 0) == 1 + assert moment(5*X, 2) == 25*moment(X, 2) + assert quantile(X)(p) == Piecewise((nan, (p > 1) | (p < 0)),\ + (S.One, p <= Rational(1, 6)), (S(2), p <= Rational(1, 3)), (S(3), p <= S.Half),\ + (S(4), p <= Rational(2, 3)), (S(5), p <= Rational(5, 6)), (S(6), p <= 1)) + + assert P(X > 3, X > 3) is S.One + assert P(X > Y, Eq(Y, 6)) is S.Zero + assert P(Eq(X + Y, 12)) == Rational(1, 36) + assert P(Eq(X + Y, 12), Eq(X, 6)) == Rational(1, 6) + + assert density(X + Y) == density(Y + Z) != density(X + X) + d = density(2*X + Y**Z) + assert d[S(22)] == Rational(1, 108) and d[S(4100)] == Rational(1, 216) and S(3130) not in d + + assert pspace(X).domain.as_boolean() == Or( + *[Eq(X.symbol, i) for i in [1, 2, 3, 4, 5, 6]]) + + assert where(X > 3).set == FiniteSet(4, 5, 6) + + assert characteristic_function(X)(t) == exp(6*I*t)/6 + exp(5*I*t)/6 + exp(4*I*t)/6 + exp(3*I*t)/6 + exp(2*I*t)/6 + exp(I*t)/6 + assert moment_generating_function(X)(t) == exp(6*t)/6 + exp(5*t)/6 + exp(4*t)/6 + exp(3*t)/6 + exp(2*t)/6 + exp(t)/6 + assert median(X) == FiniteSet(3, 4) + D = Die('D', 7) + assert median(D) == FiniteSet(4) + # Bayes test for die + BayesTest(X > 3, X + Y < 5) + BayesTest(Eq(X - Y, Z), Z > Y) + BayesTest(X > 3, X > 2) + + # arg test for die + raises(ValueError, lambda: Die('X', -1)) # issue 8105: negative sides. + raises(ValueError, lambda: Die('X', 0)) + raises(ValueError, lambda: Die('X', 1.5)) # issue 8103: non integer sides. + + # symbolic test for die + n, k = symbols('n, k', positive=True) + D = Die('D', n) + dens = density(D).dict + assert dens == Density(DieDistribution(n)) + assert set(dens.subs(n, 4).doit().keys()) == {1, 2, 3, 4} + assert set(dens.subs(n, 4).doit().values()) == {Rational(1, 4)} + k = Dummy('k', integer=True) + assert E(D).dummy_eq( + Sum(Piecewise((k/n, k <= n), (0, True)), (k, 1, n))) + assert variance(D).subs(n, 6).doit() == Rational(35, 12) + + ki = Dummy('ki') + cumuf = cdf(D)(k) + assert cumuf.dummy_eq( + Sum(Piecewise((1/n, (ki >= 1) & (ki <= n)), (0, True)), (ki, 1, k))) + assert cumuf.subs({n: 6, k: 2}).doit() == Rational(1, 3) + + t = Dummy('t') + cf = characteristic_function(D)(t) + assert cf.dummy_eq( + Sum(Piecewise((exp(ki*I*t)/n, (ki >= 1) & (ki <= n)), (0, True)), (ki, 1, n))) + assert cf.subs(n, 3).doit() == exp(3*I*t)/3 + exp(2*I*t)/3 + exp(I*t)/3 + mgf = moment_generating_function(D)(t) + assert mgf.dummy_eq( + Sum(Piecewise((exp(ki*t)/n, (ki >= 1) & (ki <= n)), (0, True)), (ki, 1, n))) + assert mgf.subs(n, 3).doit() == exp(3*t)/3 + exp(2*t)/3 + exp(t)/3 + +def test_given(): + X = Die('X', 6) + assert density(X, X > 5) == {S(6): S.One} + assert where(X > 2, X > 5).as_boolean() == Eq(X.symbol, 6) + + +def test_domains(): + X, Y = Die('x', 6), Die('y', 6) + x, y = X.symbol, Y.symbol + # Domains + d = where(X > Y) + assert d.condition == (x > y) + d = where(And(X > Y, Y > 3)) + assert d.as_boolean() == Or(And(Eq(x, 5), Eq(y, 4)), And(Eq(x, 6), + Eq(y, 5)), And(Eq(x, 6), Eq(y, 4))) + assert len(d.elements) == 3 + + assert len(pspace(X + Y).domain.elements) == 36 + + Z = Die('x', 4) + + raises(ValueError, lambda: P(X > Z)) # Two domains with same internal symbol + + assert pspace(X + Y).domain.set == FiniteSet(1, 2, 3, 4, 5, 6)**2 + + assert where(X > 3).set == FiniteSet(4, 5, 6) + assert X.pspace.domain.dict == FiniteSet( + *[Dict({X.symbol: i}) for i in range(1, 7)]) + + assert where(X > Y).dict == FiniteSet(*[Dict({X.symbol: i, Y.symbol: j}) + for i in range(1, 7) for j in range(1, 7) if i > j]) + +def test_bernoulli(): + p, a, b, t = symbols('p a b t') + X = Bernoulli('B', p, a, b) + + assert E(X) == a*p + b*(-p + 1) + assert density(X)[a] == p + assert density(X)[b] == 1 - p + assert characteristic_function(X)(t) == p * exp(I * a * t) + (-p + 1) * exp(I * b * t) + assert moment_generating_function(X)(t) == p * exp(a * t) + (-p + 1) * exp(b * t) + + X = Bernoulli('B', p, 1, 0) + z = Symbol("z") + + assert E(X) == p + assert simplify(variance(X)) == p*(1 - p) + assert E(a*X + b) == a*E(X) + b + assert simplify(variance(a*X + b)) == simplify(a**2 * variance(X)) + assert quantile(X)(z) == Piecewise((nan, (z > 1) | (z < 0)), (0, z <= 1 - p), (1, z <= 1)) + Y = Bernoulli('Y', Rational(1, 2)) + assert median(Y) == FiniteSet(0, 1) + Z = Bernoulli('Z', Rational(2, 3)) + assert median(Z) == FiniteSet(1) + raises(ValueError, lambda: Bernoulli('B', 1.5)) + raises(ValueError, lambda: Bernoulli('B', -0.5)) + + #issue 8248 + assert X.pspace.compute_expectation(1) == 1 + + p = Rational(1, 5) + X = Binomial('X', 5, p) + Y = Binomial('Y', 7, 2*p) + Z = Binomial('Z', 9, 3*p) + assert coskewness(Y + Z, X + Y, X + Z).simplify() == 0 + assert coskewness(Y + 2*X + Z, X + 2*Y + Z, X + 2*Z + Y).simplify() == \ + sqrt(1529)*Rational(12, 16819) + assert coskewness(Y + 2*X + Z, X + 2*Y + Z, X + 2*Z + Y, X < 2).simplify() \ + == -sqrt(357451121)*Rational(2812, 4646864573) + +def test_cdf(): + D = Die('D', 6) + o = S.One + + assert cdf( + D) == sympify({1: o/6, 2: o/3, 3: o/2, 4: 2*o/3, 5: 5*o/6, 6: o}) + + +def test_coins(): + C, D = Coin('C'), Coin('D') + H, T = symbols('H, T') + assert P(Eq(C, D)) == S.Half + assert density(Tuple(C, D)) == {(H, H): Rational(1, 4), (H, T): Rational(1, 4), + (T, H): Rational(1, 4), (T, T): Rational(1, 4)} + assert dict(density(C).items()) == {H: S.Half, T: S.Half} + + F = Coin('F', Rational(1, 10)) + assert P(Eq(F, H)) == Rational(1, 10) + + d = pspace(C).domain + + assert d.as_boolean() == Or(Eq(C.symbol, H), Eq(C.symbol, T)) + + raises(ValueError, lambda: P(C > D)) # Can't intelligently compare H to T + +def test_binomial_verify_parameters(): + raises(ValueError, lambda: Binomial('b', .2, .5)) + raises(ValueError, lambda: Binomial('b', 3, 1.5)) + +def test_binomial_numeric(): + nvals = range(5) + pvals = [0, Rational(1, 4), S.Half, Rational(3, 4), 1] + + for n in nvals: + for p in pvals: + X = Binomial('X', n, p) + assert E(X) == n*p + assert variance(X) == n*p*(1 - p) + if n > 0 and 0 < p < 1: + assert skewness(X) == (1 - 2*p)/sqrt(n*p*(1 - p)) + assert kurtosis(X) == 3 + (1 - 6*p*(1 - p))/(n*p*(1 - p)) + for k in range(n + 1): + assert P(Eq(X, k)) == binomial(n, k)*p**k*(1 - p)**(n - k) + +def test_binomial_quantile(): + X = Binomial('X', 50, S.Half) + assert quantile(X)(0.95) == S(31) + assert median(X) == FiniteSet(25) + + X = Binomial('X', 5, S.Half) + p = Symbol("p", positive=True) + assert quantile(X)(p) == Piecewise((nan, p > S.One), (S.Zero, p <= Rational(1, 32)),\ + (S.One, p <= Rational(3, 16)), (S(2), p <= S.Half), (S(3), p <= Rational(13, 16)),\ + (S(4), p <= Rational(31, 32)), (S(5), p <= S.One)) + assert median(X) == FiniteSet(2, 3) + + +def test_binomial_symbolic(): + n = 2 + p = symbols('p', positive=True) + X = Binomial('X', n, p) + t = Symbol('t') + + assert simplify(E(X)) == n*p == simplify(moment(X, 1)) + assert simplify(variance(X)) == n*p*(1 - p) == simplify(cmoment(X, 2)) + assert cancel(skewness(X) - (1 - 2*p)/sqrt(n*p*(1 - p))) == 0 + assert cancel((kurtosis(X)) - (3 + (1 - 6*p*(1 - p))/(n*p*(1 - p)))) == 0 + assert characteristic_function(X)(t) == p ** 2 * exp(2 * I * t) + 2 * p * (-p + 1) * exp(I * t) + (-p + 1) ** 2 + assert moment_generating_function(X)(t) == p ** 2 * exp(2 * t) + 2 * p * (-p + 1) * exp(t) + (-p + 1) ** 2 + + # Test ability to change success/failure winnings + H, T = symbols('H T') + Y = Binomial('Y', n, p, succ=H, fail=T) + assert simplify(E(Y) - (n*(H*p + T*(1 - p)))) == 0 + + # test symbolic dimensions + n = symbols('n') + B = Binomial('B', n, p) + raises(NotImplementedError, lambda: P(B > 2)) + assert density(B).dict == Density(BinomialDistribution(n, p, 1, 0)) + assert set(density(B).dict.subs(n, 4).doit().keys()) == \ + {S.Zero, S.One, S(2), S(3), S(4)} + assert set(density(B).dict.subs(n, 4).doit().values()) == \ + {(1 - p)**4, 4*p*(1 - p)**3, 6*p**2*(1 - p)**2, 4*p**3*(1 - p), p**4} + k = Dummy('k', integer=True) + assert E(B > 2).dummy_eq( + Sum(Piecewise((k*p**k*(1 - p)**(-k + n)*binomial(n, k), (k >= 0) + & (k <= n) & (k > 2)), (0, True)), (k, 0, n))) + +def test_beta_binomial(): + # verify parameters + raises(ValueError, lambda: BetaBinomial('b', .2, 1, 2)) + raises(ValueError, lambda: BetaBinomial('b', 2, -1, 2)) + raises(ValueError, lambda: BetaBinomial('b', 2, 1, -2)) + assert BetaBinomial('b', 2, 1, 1) + + # test numeric values + nvals = range(1,5) + alphavals = [Rational(1, 4), S.Half, Rational(3, 4), 1, 10] + betavals = [Rational(1, 4), S.Half, Rational(3, 4), 1, 10] + + for n in nvals: + for a in alphavals: + for b in betavals: + X = BetaBinomial('X', n, a, b) + assert E(X) == moment(X, 1) + assert variance(X) == cmoment(X, 2) + + # test symbolic + n, a, b = symbols('a b n') + assert BetaBinomial('x', n, a, b) + n = 2 # Because we're using for loops, can't do symbolic n + a, b = symbols('a b', positive=True) + X = BetaBinomial('X', n, a, b) + t = Symbol('t') + + assert E(X).expand() == moment(X, 1).expand() + assert variance(X).expand() == cmoment(X, 2).expand() + assert skewness(X) == smoment(X, 3) + assert characteristic_function(X)(t) == exp(2*I*t)*beta(a + 2, b)/beta(a, b) +\ + 2*exp(I*t)*beta(a + 1, b + 1)/beta(a, b) + beta(a, b + 2)/beta(a, b) + assert moment_generating_function(X)(t) == exp(2*t)*beta(a + 2, b)/beta(a, b) +\ + 2*exp(t)*beta(a + 1, b + 1)/beta(a, b) + beta(a, b + 2)/beta(a, b) + +def test_hypergeometric_numeric(): + for N in range(1, 5): + for m in range(0, N + 1): + for n in range(1, N + 1): + X = Hypergeometric('X', N, m, n) + N, m, n = map(sympify, (N, m, n)) + assert sum(density(X).values()) == 1 + assert E(X) == n * m / N + if N > 1: + assert variance(X) == n*(m/N)*(N - m)/N*(N - n)/(N - 1) + # Only test for skewness when defined + if N > 2 and 0 < m < N and n < N: + assert skewness(X) == simplify((N - 2*m)*sqrt(N - 1)*(N - 2*n) + / (sqrt(n*m*(N - m)*(N - n))*(N - 2))) + +def test_hypergeometric_symbolic(): + N, m, n = symbols('N, m, n') + H = Hypergeometric('H', N, m, n) + dens = density(H).dict + expec = E(H > 2) + assert dens == Density(HypergeometricDistribution(N, m, n)) + assert dens.subs(N, 5).doit() == Density(HypergeometricDistribution(5, m, n)) + assert set(dens.subs({N: 3, m: 2, n: 1}).doit().keys()) == {S.Zero, S.One} + assert set(dens.subs({N: 3, m: 2, n: 1}).doit().values()) == {Rational(1, 3), Rational(2, 3)} + k = Dummy('k', integer=True) + assert expec.dummy_eq( + Sum(Piecewise((k*binomial(m, k)*binomial(N - m, -k + n) + /binomial(N, n), k > 2), (0, True)), (k, 0, n))) + +def test_rademacher(): + X = Rademacher('X') + t = Symbol('t') + + assert E(X) == 0 + assert variance(X) == 1 + assert density(X)[-1] == S.Half + assert density(X)[1] == S.Half + assert characteristic_function(X)(t) == exp(I*t)/2 + exp(-I*t)/2 + assert moment_generating_function(X)(t) == exp(t) / 2 + exp(-t) / 2 + +def test_ideal_soliton(): + raises(ValueError, lambda : IdealSoliton('sol', -12)) + raises(ValueError, lambda : IdealSoliton('sol', 13.2)) + raises(ValueError, lambda : IdealSoliton('sol', 0)) + f = Function('f') + raises(ValueError, lambda : density(IdealSoliton('sol', 10)).pmf(f)) + + k = Symbol('k', integer=True, positive=True) + x = Symbol('x', integer=True, positive=True) + t = Symbol('t') + sol = IdealSoliton('sol', k) + assert density(sol).low == S.One + assert density(sol).high == k + assert density(sol).dict == Density(density(sol)) + assert density(sol).pmf(x) == Piecewise((1/k, Eq(x, 1)), (1/(x*(x - 1)), k >= x), (0, True)) + + k_vals = [5, 20, 50, 100, 1000] + for i in k_vals: + assert E(sol.subs(k, i)) == harmonic(i) == moment(sol.subs(k, i), 1) + assert variance(sol.subs(k, i)) == (i - 1) + harmonic(i) - harmonic(i)**2 == cmoment(sol.subs(k, i),2) + assert skewness(sol.subs(k, i)) == smoment(sol.subs(k, i), 3) + assert kurtosis(sol.subs(k, i)) == smoment(sol.subs(k, i), 4) + + assert exp(I*t)/10 + Sum(exp(I*t*x)/(x*x - x), (x, 2, k)).subs(k, 10).doit() == characteristic_function(sol.subs(k, 10))(t) + assert exp(t)/10 + Sum(exp(t*x)/(x*x - x), (x, 2, k)).subs(k, 10).doit() == moment_generating_function(sol.subs(k, 10))(t) + +def test_robust_soliton(): + raises(ValueError, lambda : RobustSoliton('robSol', -12, 0.1, 0.02)) + raises(ValueError, lambda : RobustSoliton('robSol', 13, 1.89, 0.1)) + raises(ValueError, lambda : RobustSoliton('robSol', 15, 0.6, -2.31)) + f = Function('f') + raises(ValueError, lambda : density(RobustSoliton('robSol', 15, 0.6, 0.1)).pmf(f)) + + k = Symbol('k', integer=True, positive=True) + delta = Symbol('delta', positive=True) + c = Symbol('c', positive=True) + robSol = RobustSoliton('robSol', k, delta, c) + assert density(robSol).low == 1 + assert density(robSol).high == k + + k_vals = [10, 20, 50] + delta_vals = [0.2, 0.4, 0.6] + c_vals = [0.01, 0.03, 0.05] + for x in k_vals: + for y in delta_vals: + for z in c_vals: + assert E(robSol.subs({k: x, delta: y, c: z})) == moment(robSol.subs({k: x, delta: y, c: z}), 1) + assert variance(robSol.subs({k: x, delta: y, c: z})) == cmoment(robSol.subs({k: x, delta: y, c: z}), 2) + assert skewness(robSol.subs({k: x, delta: y, c: z})) == smoment(robSol.subs({k: x, delta: y, c: z}), 3) + assert kurtosis(robSol.subs({k: x, delta: y, c: z})) == smoment(robSol.subs({k: x, delta: y, c: z}), 4) + +def test_FiniteRV(): + F = FiniteRV('F', {1: S.Half, 2: Rational(1, 4), 3: Rational(1, 4)}, check=True) + p = Symbol("p", positive=True) + + assert dict(density(F).items()) == {S.One: S.Half, S(2): Rational(1, 4), S(3): Rational(1, 4)} + assert P(F >= 2) == S.Half + assert quantile(F)(p) == Piecewise((nan, p > S.One), (S.One, p <= S.Half),\ + (S(2), p <= Rational(3, 4)),(S(3), True)) + + assert pspace(F).domain.as_boolean() == Or( + *[Eq(F.symbol, i) for i in [1, 2, 3]]) + + assert F.pspace.domain.set == FiniteSet(1, 2, 3) + raises(ValueError, lambda: FiniteRV('F', {1: S.Half, 2: S.Half, 3: S.Half}, check=True)) + raises(ValueError, lambda: FiniteRV('F', {1: S.Half, 2: Rational(-1, 2), 3: S.One}, check=True)) + raises(ValueError, lambda: FiniteRV('F', {1: S.One, 2: Rational(3, 2), 3: S.Zero,\ + 4: Rational(-1, 2), 5: Rational(-3, 4), 6: Rational(-1, 4)}, check=True)) + + # purposeful invalid pmf but it should not raise since check=False + # see test_drv_types.test_ContinuousRV for explanation + X = FiniteRV('X', {1: 1, 2: 2}) + assert E(X) == 5 + assert P(X <= 2) + P(X > 2) != 1 + +def test_density_call(): + from sympy.abc import p + x = Bernoulli('x', p) + d = density(x) + assert d(0) == 1 - p + assert d(S.Zero) == 1 - p + assert d(5) == 0 + + assert 0 in d + assert 5 not in d + assert d(S.Zero) == d[S.Zero] + + +def test_DieDistribution(): + from sympy.abc import x + X = DieDistribution(6) + assert X.pmf(S.Half) is S.Zero + assert X.pmf(x).subs({x: 1}).doit() == Rational(1, 6) + assert X.pmf(x).subs({x: 7}).doit() == 0 + assert X.pmf(x).subs({x: -1}).doit() == 0 + assert X.pmf(x).subs({x: Rational(1, 3)}).doit() == 0 + raises(ValueError, lambda: X.pmf(Matrix([0, 0]))) + raises(ValueError, lambda: X.pmf(x**2 - 1)) + +def test_FinitePSpace(): + X = Die('X', 6) + space = pspace(X) + assert space.density == DieDistribution(6) + +def test_symbolic_conditions(): + B = Bernoulli('B', Rational(1, 4)) + D = Die('D', 4) + b, n = symbols('b, n') + Y = P(Eq(B, b)) + Z = E(D > n) + assert Y == \ + Piecewise((Rational(1, 4), Eq(b, 1)), (0, True)) + \ + Piecewise((Rational(3, 4), Eq(b, 0)), (0, True)) + assert Z == \ + Piecewise((Rational(1, 4), n < 1), (0, True)) + Piecewise((S.Half, n < 2), (0, True)) + \ + Piecewise((Rational(3, 4), n < 3), (0, True)) + Piecewise((S.One, n < 4), (0, True)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_joint_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_joint_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..057fc313dfbb31826b07fd1315205d22b86a7f96 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_joint_rv.py @@ -0,0 +1,436 @@ +from sympy.concrete.products import Product +from sympy.concrete.summations import Sum +from sympy.core.numbers import (Rational, oo, pi) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import symbols +from sympy.functions.combinatorial.factorials import (RisingFactorial, factorial) +from sympy.functions.elementary.complexes import polar_lift +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.bessel import besselk +from sympy.functions.special.gamma_functions import gamma +from sympy.matrices.dense import eye +from sympy.matrices.expressions.determinant import Determinant +from sympy.sets.fancysets import Range +from sympy.sets.sets import (Interval, ProductSet) +from sympy.simplify.simplify import simplify +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.core.numbers import comp +from sympy.integrals.integrals import integrate +from sympy.matrices import Matrix, MatrixSymbol +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.stats import density, median, marginal_distribution, Normal, Laplace, E, sample +from sympy.stats.joint_rv_types import (JointRV, MultivariateNormalDistribution, + JointDistributionHandmade, MultivariateT, NormalGamma, + GeneralizedMultivariateLogGammaOmega as GMVLGO, MultivariateBeta, + GeneralizedMultivariateLogGamma as GMVLG, MultivariateEwens, + Multinomial, NegativeMultinomial, MultivariateNormal, + MultivariateLaplace) +from sympy.testing.pytest import raises, XFAIL, skip, slow +from sympy.external import import_module + +from sympy.abc import x, y + + + +def test_Normal(): + m = Normal('A', [1, 2], [[1, 0], [0, 1]]) + A = MultivariateNormal('A', [1, 2], [[1, 0], [0, 1]]) + assert m == A + assert density(m)(1, 2) == 1/(2*pi) + assert m.pspace.distribution.set == ProductSet(S.Reals, S.Reals) + raises (ValueError, lambda:m[2]) + n = Normal('B', [1, 2, 3], [[1, 0, 0], [0, 1, 0], [0, 0, 1]]) + p = Normal('C', Matrix([1, 2]), Matrix([[1, 0], [0, 1]])) + assert density(m)(x, y) == density(p)(x, y) + assert marginal_distribution(n, 0, 1)(1, 2) == 1/(2*pi) + raises(ValueError, lambda: marginal_distribution(m)) + assert integrate(density(m)(x, y), (x, -oo, oo), (y, -oo, oo)).evalf() == 1.0 + N = Normal('N', [1, 2], [[x, 0], [0, y]]) + assert density(N)(0, 0) == exp(-((4*x + y)/(2*x*y)))/(2*pi*sqrt(x*y)) + + raises (ValueError, lambda: Normal('M', [1, 2], [[1, 1], [1, -1]])) + # symbolic + n = symbols('n', integer=True, positive=True) + mu = MatrixSymbol('mu', n, 1) + sigma = MatrixSymbol('sigma', n, n) + X = Normal('X', mu, sigma) + assert density(X) == MultivariateNormalDistribution(mu, sigma) + raises (NotImplementedError, lambda: median(m)) + # Below tests should work after issue #17267 is resolved + # assert E(X) == mu + # assert variance(X) == sigma + + # test symbolic multivariate normal densities + n = 3 + + Sg = MatrixSymbol('Sg', n, n) + mu = MatrixSymbol('mu', n, 1) + obs = MatrixSymbol('obs', n, 1) + + X = MultivariateNormal('X', mu, Sg) + density_X = density(X) + + eval_a = density_X(obs).subs({Sg: eye(3), + mu: Matrix([0, 0, 0]), obs: Matrix([0, 0, 0])}).doit() + eval_b = density_X(0, 0, 0).subs({Sg: eye(3), mu: Matrix([0, 0, 0])}).doit() + + assert eval_a == sqrt(2)/(4*pi**Rational(3/2)) + assert eval_b == sqrt(2)/(4*pi**Rational(3/2)) + + n = symbols('n', integer=True, positive=True) + + Sg = MatrixSymbol('Sg', n, n) + mu = MatrixSymbol('mu', n, 1) + obs = MatrixSymbol('obs', n, 1) + + X = MultivariateNormal('X', mu, Sg) + density_X_at_obs = density(X)(obs) + + expected_density = MatrixElement( + exp((S(1)/2) * (mu.T - obs.T) * Sg**(-1) * (-mu + obs)) / \ + sqrt((2*pi)**n * Determinant(Sg)), 0, 0) + + assert density_X_at_obs == expected_density + + +def test_MultivariateTDist(): + t1 = MultivariateT('T', [0, 0], [[1, 0], [0, 1]], 2) + assert(density(t1))(1, 1) == 1/(8*pi) + assert t1.pspace.distribution.set == ProductSet(S.Reals, S.Reals) + assert integrate(density(t1)(x, y), (x, -oo, oo), \ + (y, -oo, oo)).evalf() == 1.0 + raises(ValueError, lambda: MultivariateT('T', [1, 2], [[1, 1], [1, -1]], 1)) + t2 = MultivariateT('t2', [1, 2], [[x, 0], [0, y]], 1) + assert density(t2)(1, 2) == 1/(2*pi*sqrt(x*y)) + + +def test_multivariate_laplace(): + raises(ValueError, lambda: Laplace('T', [1, 2], [[1, 2], [2, 1]])) + L = Laplace('L', [1, 0], [[1, 0], [0, 1]]) + L2 = MultivariateLaplace('L2', [1, 0], [[1, 0], [0, 1]]) + assert density(L)(2, 3) == exp(2)*besselk(0, sqrt(39))/pi + L1 = Laplace('L1', [1, 2], [[x, 0], [0, y]]) + assert density(L1)(0, 1) == \ + exp(2/y)*besselk(0, sqrt((2 + 4/y + 1/x)/y))/(pi*sqrt(x*y)) + assert L.pspace.distribution.set == ProductSet(S.Reals, S.Reals) + assert L.pspace.distribution == L2.pspace.distribution + + +def test_NormalGamma(): + ng = NormalGamma('G', 1, 2, 3, 4) + assert density(ng)(1, 1) == 32*exp(-4)/sqrt(pi) + assert ng.pspace.distribution.set == ProductSet(S.Reals, Interval(0, oo)) + raises(ValueError, lambda:NormalGamma('G', 1, 2, 3, -1)) + assert marginal_distribution(ng, 0)(1) == \ + 3*sqrt(10)*gamma(Rational(7, 4))/(10*sqrt(pi)*gamma(Rational(5, 4))) + assert marginal_distribution(ng, y)(1) == exp(Rational(-1, 4))/128 + assert marginal_distribution(ng,[0,1])(x) == x**2*exp(-x/4)/128 + + +def test_GeneralizedMultivariateLogGammaDistribution(): + h = S.Half + omega = Matrix([[1, h, h, h], + [h, 1, h, h], + [h, h, 1, h], + [h, h, h, 1]]) + v, l, mu = (4, [1, 2, 3, 4], [1, 2, 3, 4]) + y_1, y_2, y_3, y_4 = symbols('y_1:5', real=True) + delta = symbols('d', positive=True) + G = GMVLGO('G', omega, v, l, mu) + Gd = GMVLG('Gd', delta, v, l, mu) + dend = ("d**4*Sum(4*24**(-n - 4)*(1 - d)**n*exp((n + 4)*(y_1 + 2*y_2 + 3*y_3 " + "+ 4*y_4) - exp(y_1) - exp(2*y_2)/2 - exp(3*y_3)/3 - exp(4*y_4)/4)/" + "(gamma(n + 1)*gamma(n + 4)**3), (n, 0, oo))") + assert str(density(Gd)(y_1, y_2, y_3, y_4)) == dend + den = ("5*2**(2/3)*5**(1/3)*Sum(4*24**(-n - 4)*(-2**(2/3)*5**(1/3)/4 + 1)**n*" + "exp((n + 4)*(y_1 + 2*y_2 + 3*y_3 + 4*y_4) - exp(y_1) - exp(2*y_2)/2 - " + "exp(3*y_3)/3 - exp(4*y_4)/4)/(gamma(n + 1)*gamma(n + 4)**3), (n, 0, oo))/64") + assert str(density(G)(y_1, y_2, y_3, y_4)) == den + marg = ("5*2**(2/3)*5**(1/3)*exp(4*y_1)*exp(-exp(y_1))*Integral(exp(-exp(4*G[3])" + "/4)*exp(16*G[3])*Integral(exp(-exp(3*G[2])/3)*exp(12*G[2])*Integral(exp(" + "-exp(2*G[1])/2)*exp(8*G[1])*Sum((-1/4)**n*(-4 + 2**(2/3)*5**(1/3" + "))**n*exp(n*y_1)*exp(2*n*G[1])*exp(3*n*G[2])*exp(4*n*G[3])/(24**n*gamma(n + 1)" + "*gamma(n + 4)**3), (n, 0, oo)), (G[1], -oo, oo)), (G[2], -oo, oo)), (G[3]" + ", -oo, oo))/5308416") + assert str(marginal_distribution(G, G[0])(y_1)) == marg + omega_f1 = Matrix([[1, h, h]]) + omega_f2 = Matrix([[1, h, h, h], + [h, 1, 2, h], + [h, h, 1, h], + [h, h, h, 1]]) + omega_f3 = Matrix([[6, h, h, h], + [h, 1, 2, h], + [h, h, 1, h], + [h, h, h, 1]]) + v_f = symbols("v_f", positive=False, real=True) + l_f = [1, 2, v_f, 4] + m_f = [v_f, 2, 3, 4] + omega_f4 = Matrix([[1, h, h, h, h], + [h, 1, h, h, h], + [h, h, 1, h, h], + [h, h, h, 1, h], + [h, h, h, h, 1]]) + l_f1 = [1, 2, 3, 4, 5] + omega_f5 = Matrix([[1]]) + mu_f5 = l_f5 = [1] + + raises(ValueError, lambda: GMVLGO('G', omega_f1, v, l, mu)) + raises(ValueError, lambda: GMVLGO('G', omega_f2, v, l, mu)) + raises(ValueError, lambda: GMVLGO('G', omega_f3, v, l, mu)) + raises(ValueError, lambda: GMVLGO('G', omega, v_f, l, mu)) + raises(ValueError, lambda: GMVLGO('G', omega, v, l_f, mu)) + raises(ValueError, lambda: GMVLGO('G', omega, v, l, m_f)) + raises(ValueError, lambda: GMVLGO('G', omega_f4, v, l, mu)) + raises(ValueError, lambda: GMVLGO('G', omega, v, l_f1, mu)) + raises(ValueError, lambda: GMVLGO('G', omega_f5, v, l_f5, mu_f5)) + raises(ValueError, lambda: GMVLG('G', Rational(3, 2), v, l, mu)) + + +def test_MultivariateBeta(): + a1, a2 = symbols('a1, a2', positive=True) + a1_f, a2_f = symbols('a1, a2', positive=False, real=True) + mb = MultivariateBeta('B', [a1, a2]) + mb_c = MultivariateBeta('C', a1, a2) + assert density(mb)(1, 2) == S(2)**(a2 - 1)*gamma(a1 + a2)/\ + (gamma(a1)*gamma(a2)) + assert marginal_distribution(mb_c, 0)(3) == S(3)**(a1 - 1)*gamma(a1 + a2)/\ + (a2*gamma(a1)*gamma(a2)) + raises(ValueError, lambda: MultivariateBeta('b1', [a1_f, a2])) + raises(ValueError, lambda: MultivariateBeta('b2', [a1, a2_f])) + raises(ValueError, lambda: MultivariateBeta('b3', [0, 0])) + raises(ValueError, lambda: MultivariateBeta('b4', [a1_f, a2_f])) + assert mb.pspace.distribution.set == ProductSet(Interval(0, 1), Interval(0, 1)) + + +def test_MultivariateEwens(): + n, theta, i = symbols('n theta i', positive=True) + + # tests for integer dimensions + theta_f = symbols('t_f', negative=True) + a = symbols('a_1:4', positive = True, integer = True) + ed = MultivariateEwens('E', 3, theta) + assert density(ed)(a[0], a[1], a[2]) == Piecewise((6*2**(-a[1])*3**(-a[2])* + theta**a[0]*theta**a[1]*theta**a[2]/ + (theta*(theta + 1)*(theta + 2)* + factorial(a[0])*factorial(a[1])* + factorial(a[2])), Eq(a[0] + 2*a[1] + + 3*a[2], 3)), (0, True)) + assert marginal_distribution(ed, ed[1])(a[1]) == Piecewise((6*2**(-a[1])* + theta**a[1]/((theta + 1)* + (theta + 2)*factorial(a[1])), + Eq(2*a[1] + 1, 3)), (0, True)) + raises(ValueError, lambda: MultivariateEwens('e1', 5, theta_f)) + assert ed.pspace.distribution.set == ProductSet(Range(0, 4, 1), + Range(0, 2, 1), Range(0, 2, 1)) + + # tests for symbolic dimensions + eds = MultivariateEwens('E', n, theta) + a = IndexedBase('a') + j, k = symbols('j, k') + den = Piecewise((factorial(n)*Product(theta**a[j]*(j + 1)**(-a[j])/ + factorial(a[j]), (j, 0, n - 1))/RisingFactorial(theta, n), + Eq(n, Sum((k + 1)*a[k], (k, 0, n - 1)))), (0, True)) + assert density(eds)(a).dummy_eq(den) + + +def test_Multinomial(): + n, x1, x2, x3, x4 = symbols('n, x1, x2, x3, x4', nonnegative=True, integer=True) + p1, p2, p3, p4 = symbols('p1, p2, p3, p4', positive=True) + p1_f, n_f = symbols('p1_f, n_f', negative=True) + M = Multinomial('M', n, [p1, p2, p3, p4]) + C = Multinomial('C', 3, p1, p2, p3) + f = factorial + assert density(M)(x1, x2, x3, x4) == Piecewise((p1**x1*p2**x2*p3**x3*p4**x4* + f(n)/(f(x1)*f(x2)*f(x3)*f(x4)), + Eq(n, x1 + x2 + x3 + x4)), (0, True)) + assert marginal_distribution(C, C[0])(x1).subs(x1, 1) ==\ + 3*p1*p2**2 +\ + 6*p1*p2*p3 +\ + 3*p1*p3**2 + raises(ValueError, lambda: Multinomial('b1', 5, [p1, p2, p3, p1_f])) + raises(ValueError, lambda: Multinomial('b2', n_f, [p1, p2, p3, p4])) + raises(ValueError, lambda: Multinomial('b3', n, 0.5, 0.4, 0.3, 0.1)) + + +def test_NegativeMultinomial(): + k0, x1, x2, x3, x4 = symbols('k0, x1, x2, x3, x4', nonnegative=True, integer=True) + p1, p2, p3, p4 = symbols('p1, p2, p3, p4', positive=True) + p1_f = symbols('p1_f', negative=True) + N = NegativeMultinomial('N', 4, [p1, p2, p3, p4]) + C = NegativeMultinomial('C', 4, 0.1, 0.2, 0.3) + g = gamma + f = factorial + assert simplify(density(N)(x1, x2, x3, x4) - + p1**x1*p2**x2*p3**x3*p4**x4*(-p1 - p2 - p3 - p4 + 1)**4*g(x1 + x2 + + x3 + x4 + 4)/(6*f(x1)*f(x2)*f(x3)*f(x4))) is S.Zero + assert comp(marginal_distribution(C, C[0])(1).evalf(), 0.33, .01) + raises(ValueError, lambda: NegativeMultinomial('b1', 5, [p1, p2, p3, p1_f])) + raises(ValueError, lambda: NegativeMultinomial('b2', k0, 0.5, 0.4, 0.3, 0.4)) + assert N.pspace.distribution.set == ProductSet(Range(0, oo, 1), + Range(0, oo, 1), Range(0, oo, 1), Range(0, oo, 1)) + + +@slow +def test_JointPSpace_marginal_distribution(): + T = MultivariateT('T', [0, 0], [[1, 0], [0, 1]], 2) + got = marginal_distribution(T, T[1])(x) + ans = sqrt(2)*(x**2/2 + 1)/(4*polar_lift(x**2/2 + 1)**(S(5)/2)) + assert got == ans, got + assert integrate(marginal_distribution(T, 1)(x), (x, -oo, oo)) == 1 + + t = MultivariateT('T', [0, 0, 0], [[1, 0, 0], [0, 1, 0], [0, 0, 1]], 3) + assert comp(marginal_distribution(t, 0)(1).evalf(), 0.2, .01) + + +def test_JointRV(): + x1, x2 = (Indexed('x', i) for i in (1, 2)) + pdf = exp(-x1**2/2 + x1 - x2**2/2 - S.Half)/(2*pi) + X = JointRV('x', pdf) + assert density(X)(1, 2) == exp(-2)/(2*pi) + assert isinstance(X.pspace.distribution, JointDistributionHandmade) + assert marginal_distribution(X, 0)(2) == sqrt(2)*exp(Rational(-1, 2))/(2*sqrt(pi)) + + +def test_expectation(): + m = Normal('A', [x, y], [[1, 0], [0, 1]]) + assert simplify(E(m[1])) == y + + +@XFAIL +def test_joint_vector_expectation(): + m = Normal('A', [x, y], [[1, 0], [0, 1]]) + assert E(m) == (x, y) + + +def test_sample_numpy(): + distribs_numpy = [ + MultivariateNormal("M", [3, 4], [[2, 1], [1, 2]]), + MultivariateBeta("B", [0.4, 5, 15, 50, 203]), + Multinomial("N", 50, [0.3, 0.2, 0.1, 0.25, 0.15]) + ] + size = 3 + numpy = import_module('numpy') + if not numpy: + skip('Numpy is not installed. Abort tests for _sample_numpy.') + else: + for X in distribs_numpy: + samps = sample(X, size=size, library='numpy') + for sam in samps: + assert tuple(sam) in X.pspace.distribution.set + N_c = NegativeMultinomial('N', 3, 0.1, 0.1, 0.1) + raises(NotImplementedError, lambda: sample(N_c, library='numpy')) + + +def test_sample_scipy(): + distribs_scipy = [ + MultivariateNormal("M", [0, 0], [[0.1, 0.025], [0.025, 0.1]]), + MultivariateBeta("B", [0.4, 5, 15]), + Multinomial("N", 8, [0.3, 0.2, 0.1, 0.4]) + ] + + size = 3 + scipy = import_module('scipy') + if not scipy: + skip('Scipy not installed. Abort tests for _sample_scipy.') + else: + for X in distribs_scipy: + samps = sample(X, size=size) + samps2 = sample(X, size=(2, 2)) + for sam in samps: + assert tuple(sam) in X.pspace.distribution.set + for i in range(2): + for j in range(2): + assert tuple(samps2[i][j]) in X.pspace.distribution.set + N_c = NegativeMultinomial('N', 3, 0.1, 0.1, 0.1) + raises(NotImplementedError, lambda: sample(N_c)) + + +def test_sample_pymc(): + distribs_pymc = [ + MultivariateNormal("M", [5, 2], [[1, 0], [0, 1]]), + MultivariateBeta("B", [0.4, 5, 15]), + Multinomial("N", 4, [0.3, 0.2, 0.1, 0.4]) + ] + size = 3 + pymc = import_module('pymc') + if not pymc: + skip('PyMC is not installed. Abort tests for _sample_pymc.') + else: + for X in distribs_pymc: + samps = sample(X, size=size, library='pymc') + for sam in samps: + assert tuple(sam.flatten()) in X.pspace.distribution.set + N_c = NegativeMultinomial('N', 3, 0.1, 0.1, 0.1) + raises(NotImplementedError, lambda: sample(N_c, library='pymc')) + + +def test_sample_seed(): + x1, x2 = (Indexed('x', i) for i in (1, 2)) + pdf = exp(-x1**2/2 + x1 - x2**2/2 - S.Half)/(2*pi) + X = JointRV('x', pdf) + + libraries = ['scipy', 'numpy', 'pymc'] + for lib in libraries: + try: + imported_lib = import_module(lib) + if imported_lib: + s0, s1, s2 = [], [], [] + s0 = sample(X, size=10, library=lib, seed=0) + s1 = sample(X, size=10, library=lib, seed=0) + s2 = sample(X, size=10, library=lib, seed=1) + assert all(s0 == s1) + assert all(s1 != s2) + except NotImplementedError: + continue + +# +# XXX: This fails for pymc. Previously the test appeared to pass but that is +# just because the library argument was not passed so the test always used +# scipy. +# +def test_issue_21057(): + m = Normal("x", [0, 0], [[0, 0], [0, 0]]) + n = MultivariateNormal("x", [0, 0], [[0, 0], [0, 0]]) + p = Normal("x", [0, 0], [[0, 0], [0, 1]]) + assert m == n + libraries = ('scipy', 'numpy') # , 'pymc') # <-- pymc fails + for library in libraries: + try: + imported_lib = import_module(library) + if imported_lib: + s1 = sample(m, size=8, library=library) + s2 = sample(n, size=8, library=library) + s3 = sample(p, size=8, library=library) + assert tuple(s1.flatten()) == tuple(s2.flatten()) + for s in s3: + assert tuple(s.flatten()) in p.pspace.distribution.set + except NotImplementedError: + continue + + +# +# When this passes the pymc part can be uncommented in test_issue_21057 above +# and this can be deleted. +# +@XFAIL +def test_issue_21057_pymc(): + m = Normal("x", [0, 0], [[0, 0], [0, 0]]) + n = MultivariateNormal("x", [0, 0], [[0, 0], [0, 0]]) + p = Normal("x", [0, 0], [[0, 0], [0, 1]]) + assert m == n + libraries = ('pymc',) + for library in libraries: + try: + imported_lib = import_module(library) + if imported_lib: + s1 = sample(m, size=8, library=library) + s2 = sample(n, size=8, library=library) + s3 = sample(p, size=8, library=library) + assert tuple(s1.flatten()) == tuple(s2.flatten()) + for s in s3: + assert tuple(s.flatten()) in p.pspace.distribution.set + except NotImplementedError: + continue diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_matrix_distributions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_matrix_distributions.py new file mode 100644 index 0000000000000000000000000000000000000000..a2a2dcdd853793d9f77e1a88adf63158ed68e3ba --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_matrix_distributions.py @@ -0,0 +1,186 @@ +from sympy.concrete.products import Product +from sympy.core.numbers import pi +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, symbols) +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.special.gamma_functions import gamma +from sympy.matrices import Determinant, Matrix, Trace, MatrixSymbol, MatrixSet +from sympy.stats import density, sample +from sympy.stats.matrix_distributions import (MatrixGammaDistribution, + MatrixGamma, MatrixPSpace, Wishart, MatrixNormal, MatrixStudentT) +from sympy.testing.pytest import raises, skip +from sympy.external import import_module + + +def test_MatrixPSpace(): + M = MatrixGammaDistribution(1, 2, [[2, 1], [1, 2]]) + MP = MatrixPSpace('M', M, 2, 2) + assert MP.distribution == M + raises(ValueError, lambda: MatrixPSpace('M', M, 1.2, 2)) + +def test_MatrixGamma(): + M = MatrixGamma('M', 1, 2, [[1, 0], [0, 1]]) + assert M.pspace.distribution.set == MatrixSet(2, 2, S.Reals) + assert isinstance(density(M), MatrixGammaDistribution) + X = MatrixSymbol('X', 2, 2) + num = exp(Trace(Matrix([[-S(1)/2, 0], [0, -S(1)/2]])*X)) + assert density(M)(X).doit() == num/(4*pi*sqrt(Determinant(X))) + assert density(M)([[2, 1], [1, 2]]).doit() == sqrt(3)*exp(-2)/(12*pi) + X = MatrixSymbol('X', 1, 2) + Y = MatrixSymbol('Y', 1, 2) + assert density(M)([X, Y]).doit() == exp(-X[0, 0]/2 - Y[0, 1]/2)/(4*pi*sqrt( + X[0, 0]*Y[0, 1] - X[0, 1]*Y[0, 0])) + # symbolic + a, b = symbols('a b', positive=True) + d = symbols('d', positive=True, integer=True) + Y = MatrixSymbol('Y', d, d) + Z = MatrixSymbol('Z', 2, 2) + SM = MatrixSymbol('SM', d, d) + M2 = MatrixGamma('M2', a, b, SM) + M3 = MatrixGamma('M3', 2, 3, [[2, 1], [1, 2]]) + k = Dummy('k') + exprd = pi**(-d*(d - 1)/4)*b**(-a*d)*exp(Trace((-1/b)*SM**(-1)*Y) + )*Determinant(SM)**(-a)*Determinant(Y)**(a - d/2 - S(1)/2)/Product( + gamma(-k/2 + a + S(1)/2), (k, 1, d)) + assert density(M2)(Y).dummy_eq(exprd) + raises(NotImplementedError, lambda: density(M3 + M)(Z)) + raises(ValueError, lambda: density(M)(1)) + raises(ValueError, lambda: MatrixGamma('M', -1, 2, [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixGamma('M', -1, -2, [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixGamma('M', -1, 2, [[1, 0], [2, 1]])) + raises(ValueError, lambda: MatrixGamma('M', -1, 2, [[1, 0], [0]])) + +def test_Wishart(): + W = Wishart('W', 5, [[1, 0], [0, 1]]) + assert W.pspace.distribution.set == MatrixSet(2, 2, S.Reals) + X = MatrixSymbol('X', 2, 2) + term1 = exp(Trace(Matrix([[-S(1)/2, 0], [0, -S(1)/2]])*X)) + assert density(W)(X).doit() == term1 * Determinant(X)/(24*pi) + assert density(W)([[2, 1], [1, 2]]).doit() == exp(-2)/(8*pi) + n = symbols('n', positive=True) + d = symbols('d', positive=True, integer=True) + Y = MatrixSymbol('Y', d, d) + SM = MatrixSymbol('SM', d, d) + W = Wishart('W', n, SM) + k = Dummy('k') + exprd = 2**(-d*n/2)*pi**(-d*(d - 1)/4)*exp(Trace(-(S(1)/2)*SM**(-1)*Y) + )*Determinant(SM)**(-n/2)*Determinant(Y)**( + -d/2 + n/2 - S(1)/2)/Product(gamma(-k/2 + n/2 + S(1)/2), (k, 1, d)) + assert density(W)(Y).dummy_eq(exprd) + raises(ValueError, lambda: density(W)(1)) + raises(ValueError, lambda: Wishart('W', -1, [[1, 0], [0, 1]])) + raises(ValueError, lambda: Wishart('W', -1, [[1, 0], [2, 1]])) + raises(ValueError, lambda: Wishart('W', 2, [[1, 0], [0]])) + +def test_MatrixNormal(): + M = MatrixNormal('M', [[5, 6]], [4], [[2, 1], [1, 2]]) + assert M.pspace.distribution.set == MatrixSet(1, 2, S.Reals) + X = MatrixSymbol('X', 1, 2) + term1 = exp(-Trace(Matrix([[ S(2)/3, -S(1)/3], [-S(1)/3, S(2)/3]])*( + Matrix([[-5], [-6]]) + X.T)*Matrix([[S(1)/4]])*(Matrix([[-5, -6]]) + X))/2) + assert density(M)(X).doit() == (sqrt(3)) * term1/(24*pi) + assert density(M)([[7, 8]]).doit() == sqrt(3)*exp(-S(1)/3)/(24*pi) + d, n = symbols('d n', positive=True, integer=True) + SM2 = MatrixSymbol('SM2', d, d) + SM1 = MatrixSymbol('SM1', n, n) + LM = MatrixSymbol('LM', n, d) + Y = MatrixSymbol('Y', n, d) + M = MatrixNormal('M', LM, SM1, SM2) + exprd = (2*pi)**(-d*n/2)*exp(-Trace(SM2**(-1)*(-LM.T + Y.T)*SM1**(-1)*(-LM + Y) + )/2)*Determinant(SM1)**(-d/2)*Determinant(SM2)**(-n/2) + assert density(M)(Y).doit() == exprd + raises(ValueError, lambda: density(M)(1)) + raises(ValueError, lambda: MatrixNormal('M', [1, 2], [[1, 0], [0, 1]], [[1, 0], [2, 1]])) + raises(ValueError, lambda: MatrixNormal('M', [1, 2], [[1, 0], [2, 1]], [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixNormal('M', [1, 2], [[1, 0], [0, 1]], [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixNormal('M', [1, 2], [[1, 0], [2]], [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixNormal('M', [1, 2], [[1, 0], [2, 1]], [[1, 0], [0]])) + raises(ValueError, lambda: MatrixNormal('M', [[1, 2]], [[1, 0], [0, 1]], [[1, 0]])) + raises(ValueError, lambda: MatrixNormal('M', [[1, 2]], [1], [[1, 0]])) + +def test_MatrixStudentT(): + M = MatrixStudentT('M', 2, [[5, 6]], [[2, 1], [1, 2]], [4]) + assert M.pspace.distribution.set == MatrixSet(1, 2, S.Reals) + X = MatrixSymbol('X', 1, 2) + D = pi ** (-1.0) * Determinant(Matrix([[4]])) ** (-1.0) * Determinant(Matrix([[2, 1], [1, 2]])) \ + ** (-0.5) / Determinant(Matrix([[S(1) / 4]]) * (Matrix([[-5, -6]]) + X) + * Matrix([[S(2) / 3, -S(1) / 3], [-S(1) / 3, S(2) / 3]]) * ( + Matrix([[-5], [-6]]) + X.T) + Matrix([[1]])) ** 2 + assert density(M)(X) == D + + v = symbols('v', positive=True) + n, p = 1, 2 + Omega = MatrixSymbol('Omega', p, p) + Sigma = MatrixSymbol('Sigma', n, n) + Location = MatrixSymbol('Location', n, p) + Y = MatrixSymbol('Y', n, p) + M = MatrixStudentT('M', v, Location, Omega, Sigma) + + exprd = gamma(v/2 + 1)*Determinant(Matrix([[1]]) + Sigma**(-1)*(-Location + Y)*Omega**(-1)*(-Location.T + Y.T))**(-v/2 - 1) / \ + (pi*gamma(v/2)*sqrt(Determinant(Omega))*Determinant(Sigma)) + + assert density(M)(Y) == exprd + raises(ValueError, lambda: density(M)(1)) + raises(ValueError, lambda: MatrixStudentT('M', 1, [1, 2], [[1, 0], [0, 1]], [[1, 0], [2, 1]])) + raises(ValueError, lambda: MatrixStudentT('M', 1, [1, 2], [[1, 0], [2, 1]], [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixStudentT('M', 1, [1, 2], [[1, 0], [0, 1]], [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixStudentT('M', 1, [1, 2], [[1, 0], [2]], [[1, 0], [0, 1]])) + raises(ValueError, lambda: MatrixStudentT('M', 1, [1, 2], [[1, 0], [2, 1]], [[1], [2]])) + raises(ValueError, lambda: MatrixStudentT('M', 1, [[1, 2]], [[1, 0], [0, 1]], [[1, 0]])) + raises(ValueError, lambda: MatrixStudentT('M', 1, [[1, 2]], [1], [[1, 0]])) + raises(ValueError, lambda: MatrixStudentT('M', -1, [1, 2], [[1, 0], [0, 1]], [4])) + +def test_sample_scipy(): + distribs_scipy = [ + MatrixNormal('M', [[5, 6]], [4], [[2, 1], [1, 2]]), + Wishart('W', 5, [[1, 0], [0, 1]]) + ] + + size = 5 + scipy = import_module('scipy') + if not scipy: + skip('Scipy not installed. Abort tests for _sample_scipy.') + else: + for X in distribs_scipy: + samps = sample(X, size=size) + for sam in samps: + assert Matrix(sam) in X.pspace.distribution.set + M = MatrixGamma('M', 1, 2, [[1, 0], [0, 1]]) + raises(NotImplementedError, lambda: sample(M, size=3)) + +def test_sample_pymc(): + distribs_pymc = [ + MatrixNormal('M', [[5, 6], [3, 4]], [[1, 0], [0, 1]], [[2, 1], [1, 2]]), + Wishart('W', 7, [[2, 1], [1, 2]]) + ] + size = 3 + pymc = import_module('pymc') + if not pymc: + skip('PyMC is not installed. Abort tests for _sample_pymc.') + else: + for X in distribs_pymc: + samps = sample(X, size=size, library='pymc') + for sam in samps: + assert Matrix(sam) in X.pspace.distribution.set + M = MatrixGamma('M', 1, 2, [[1, 0], [0, 1]]) + raises(NotImplementedError, lambda: sample(M, size=3)) + +def test_sample_seed(): + X = MatrixNormal('M', [[5, 6], [3, 4]], [[1, 0], [0, 1]], [[2, 1], [1, 2]]) + + libraries = ['scipy', 'numpy', 'pymc'] + for lib in libraries: + try: + imported_lib = import_module(lib) + if imported_lib: + s0, s1, s2 = [], [], [] + s0 = sample(X, size=10, library=lib, seed=0) + s1 = sample(X, size=10, library=lib, seed=0) + s2 = sample(X, size=10, library=lib, seed=1) + for i in range(10): + assert (s0[i] == s1[i]).all() + assert (s1[i] != s2[i]).all() + + except NotImplementedError: + continue diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_mix.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_mix.py new file mode 100644 index 0000000000000000000000000000000000000000..4334d9b144a5ddaad938f195f0276e0e8993aa35 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_mix.py @@ -0,0 +1,82 @@ +from sympy.concrete.summations import Sum +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.numbers import (Integer, oo, pi) +from sympy.core.power import Pow +from sympy.core.relational import (Eq, Ne) +from sympy.core.symbol import (Dummy, Symbol, symbols) +from sympy.functions.combinatorial.factorials import factorial +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.delta_functions import DiracDelta +from sympy.functions.special.gamma_functions import gamma +from sympy.integrals.integrals import Integral +from sympy.simplify.simplify import simplify +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.functions.elementary.piecewise import ExprCondPair +from sympy.stats import (Poisson, Beta, Exponential, P, + Multinomial, MultivariateBeta) +from sympy.stats.crv_types import Normal +from sympy.stats.drv_types import PoissonDistribution +from sympy.stats.compound_rv import CompoundPSpace, CompoundDistribution +from sympy.stats.joint_rv import MarginalDistribution +from sympy.stats.rv import pspace, density +from sympy.testing.pytest import ignore_warnings + +def test_density(): + x = Symbol('x') + l = Symbol('l', positive=True) + rate = Beta(l, 2, 3) + X = Poisson(x, rate) + assert isinstance(pspace(X), CompoundPSpace) + assert density(X, Eq(rate, rate.symbol)) == PoissonDistribution(l) + N1 = Normal('N1', 0, 1) + N2 = Normal('N2', N1, 2) + assert density(N2)(0).doit() == sqrt(10)/(10*sqrt(pi)) + assert simplify(density(N2, Eq(N1, 1))(x)) == \ + sqrt(2)*exp(-(x - 1)**2/8)/(4*sqrt(pi)) + assert simplify(density(N2)(x)) == sqrt(10)*exp(-x**2/10)/(10*sqrt(pi)) + +def test_MarginalDistribution(): + a1, p1, p2 = symbols('a1 p1 p2', positive=True) + C = Multinomial('C', 2, p1, p2) + B = MultivariateBeta('B', a1, C[0]) + MGR = MarginalDistribution(B, (C[0],)) + mgrc = Mul(Symbol('B'), Piecewise(ExprCondPair(Mul(Integer(2), + Pow(Symbol('p1', positive=True), Indexed(IndexedBase(Symbol('C')), + Integer(0))), Pow(Symbol('p2', positive=True), + Indexed(IndexedBase(Symbol('C')), Integer(1))), + Pow(factorial(Indexed(IndexedBase(Symbol('C')), Integer(0))), Integer(-1)), + Pow(factorial(Indexed(IndexedBase(Symbol('C')), Integer(1))), Integer(-1))), + Eq(Add(Indexed(IndexedBase(Symbol('C')), Integer(0)), + Indexed(IndexedBase(Symbol('C')), Integer(1))), Integer(2))), + ExprCondPair(Integer(0), True)), Pow(gamma(Symbol('a1', positive=True)), + Integer(-1)), gamma(Add(Symbol('a1', positive=True), + Indexed(IndexedBase(Symbol('C')), Integer(0)))), + Pow(gamma(Indexed(IndexedBase(Symbol('C')), Integer(0))), Integer(-1)), + Pow(Indexed(IndexedBase(Symbol('B')), Integer(0)), + Add(Symbol('a1', positive=True), Integer(-1))), + Pow(Indexed(IndexedBase(Symbol('B')), Integer(1)), + Add(Indexed(IndexedBase(Symbol('C')), Integer(0)), Integer(-1)))) + assert MGR(C) == mgrc + +def test_compound_distribution(): + Y = Poisson('Y', 1) + Z = Poisson('Z', Y) + assert isinstance(pspace(Z), CompoundPSpace) + assert isinstance(pspace(Z).distribution, CompoundDistribution) + assert Z.pspace.distribution.pdf(1).doit() == exp(-2)*exp(exp(-1)) + +def test_mix_expression(): + Y, E = Poisson('Y', 1), Exponential('E', 1) + k = Dummy('k') + expr1 = Integral(Sum(exp(-1)*Integral(exp(-k)*DiracDelta(k - 2), (k, 0, oo) + )/factorial(k), (k, 0, oo)), (k, -oo, 0)) + expr2 = Integral(Sum(exp(-1)*Integral(exp(-k)*DiracDelta(k - 2), (k, 0, oo) + )/factorial(k), (k, 0, oo)), (k, 0, oo)) + assert P(Eq(Y + E, 1)) == 0 + assert P(Ne(Y + E, 2)) == 1 + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + assert P(E + Y < 2, evaluate=False).rewrite(Integral).dummy_eq(expr1) + assert P(E + Y > 2, evaluate=False).rewrite(Integral).dummy_eq(expr2) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_random_matrix.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_random_matrix.py new file mode 100644 index 0000000000000000000000000000000000000000..ba570a16bc42620d53bce19be71e7d125965ede1 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_random_matrix.py @@ -0,0 +1,135 @@ +from sympy.concrete.products import Product +from sympy.core.function import Lambda +from sympy.core.numbers import (I, Rational, pi) +from sympy.core.singleton import S +from sympy.core.symbol import Dummy +from sympy.functions.elementary.complexes import Abs +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.integrals.integrals import Integral +from sympy.matrices.dense import Matrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.trace import Trace +from sympy.tensor.indexed import IndexedBase +from sympy.stats import (GaussianUnitaryEnsemble as GUE, density, + GaussianOrthogonalEnsemble as GOE, + GaussianSymplecticEnsemble as GSE, + joint_eigen_distribution, + CircularUnitaryEnsemble as CUE, + CircularOrthogonalEnsemble as COE, + CircularSymplecticEnsemble as CSE, + JointEigenDistribution, + level_spacing_distribution, + Normal, Beta) +from sympy.stats.joint_rv_types import JointDistributionHandmade +from sympy.stats.rv import RandomMatrixSymbol +from sympy.stats.random_matrix_models import GaussianEnsemble, RandomMatrixPSpace +from sympy.testing.pytest import raises + +def test_GaussianEnsemble(): + G = GaussianEnsemble('G', 3) + assert density(G) == G.pspace.model + raises(ValueError, lambda: GaussianEnsemble('G', 3.5)) + +def test_GaussianUnitaryEnsemble(): + H = RandomMatrixSymbol('H', 3, 3) + G = GUE('U', 3) + assert density(G)(H) == sqrt(2)*exp(-3*Trace(H**2)/2)/(4*pi**Rational(9, 2)) + i, j = (Dummy('i', integer=True, positive=True), + Dummy('j', integer=True, positive=True)) + l = IndexedBase('l') + assert joint_eigen_distribution(G).dummy_eq( + Lambda((l[1], l[2], l[3]), + 27*sqrt(6)*exp(-3*(l[1]**2)/2 - 3*(l[2]**2)/2 - 3*(l[3]**2)/2)* + Product(Abs(l[i] - l[j])**2, (j, i + 1, 3), (i, 1, 2))/(16*pi**Rational(3, 2)))) + s = Dummy('s') + assert level_spacing_distribution(G).dummy_eq(Lambda(s, 32*s**2*exp(-4*s**2/pi)/pi**2)) + + +def test_GaussianOrthogonalEnsemble(): + H = RandomMatrixSymbol('H', 3, 3) + _H = MatrixSymbol('_H', 3, 3) + G = GOE('O', 3) + assert density(G)(H) == exp(-3*Trace(H**2)/4)/Integral(exp(-3*Trace(_H**2)/4), _H) + i, j = (Dummy('i', integer=True, positive=True), + Dummy('j', integer=True, positive=True)) + l = IndexedBase('l') + assert joint_eigen_distribution(G).dummy_eq( + Lambda((l[1], l[2], l[3]), + 9*sqrt(2)*exp(-3*l[1]**2/2 - 3*l[2]**2/2 - 3*l[3]**2/2)* + Product(Abs(l[i] - l[j]), (j, i + 1, 3), (i, 1, 2))/(32*pi))) + s = Dummy('s') + assert level_spacing_distribution(G).dummy_eq(Lambda(s, s*pi*exp(-s**2*pi/4)/2)) + +def test_GaussianSymplecticEnsemble(): + H = RandomMatrixSymbol('H', 3, 3) + _H = MatrixSymbol('_H', 3, 3) + G = GSE('O', 3) + assert density(G)(H) == exp(-3*Trace(H**2))/Integral(exp(-3*Trace(_H**2)), _H) + i, j = (Dummy('i', integer=True, positive=True), + Dummy('j', integer=True, positive=True)) + l = IndexedBase('l') + assert joint_eigen_distribution(G).dummy_eq( + Lambda((l[1], l[2], l[3]), + 162*sqrt(3)*exp(-3*l[1]**2/2 - 3*l[2]**2/2 - 3*l[3]**2/2)* + Product(Abs(l[i] - l[j])**4, (j, i + 1, 3), (i, 1, 2))/(5*pi**Rational(3, 2)))) + s = Dummy('s') + assert level_spacing_distribution(G).dummy_eq(Lambda(s, S(262144)*s**4*exp(-64*s**2/(9*pi))/(729*pi**3))) + +def test_CircularUnitaryEnsemble(): + CU = CUE('U', 3) + j, k = (Dummy('j', integer=True, positive=True), + Dummy('k', integer=True, positive=True)) + t = IndexedBase('t') + assert joint_eigen_distribution(CU).dummy_eq( + Lambda((t[1], t[2], t[3]), + Product(Abs(exp(I*t[j]) - exp(I*t[k]))**2, + (j, k + 1, 3), (k, 1, 2))/(48*pi**3)) + ) + +def test_CircularOrthogonalEnsemble(): + CO = COE('U', 3) + j, k = (Dummy('j', integer=True, positive=True), + Dummy('k', integer=True, positive=True)) + t = IndexedBase('t') + assert joint_eigen_distribution(CO).dummy_eq( + Lambda((t[1], t[2], t[3]), + Product(Abs(exp(I*t[j]) - exp(I*t[k])), + (j, k + 1, 3), (k, 1, 2))/(48*pi**2)) + ) + +def test_CircularSymplecticEnsemble(): + CS = CSE('U', 3) + j, k = (Dummy('j', integer=True, positive=True), + Dummy('k', integer=True, positive=True)) + t = IndexedBase('t') + assert joint_eigen_distribution(CS).dummy_eq( + Lambda((t[1], t[2], t[3]), + Product(Abs(exp(I*t[j]) - exp(I*t[k]))**4, + (j, k + 1, 3), (k, 1, 2))/(720*pi**3)) + ) + +def test_JointEigenDistribution(): + A = Matrix([[Normal('A00', 0, 1), Normal('A01', 1, 1)], + [Beta('A10', 1, 1), Beta('A11', 1, 1)]]) + assert JointEigenDistribution(A) == \ + JointDistributionHandmade(-sqrt(A[0, 0]**2 - 2*A[0, 0]*A[1, 1] + 4*A[0, 1]*A[1, 0] + A[1, 1]**2)/2 + + A[0, 0]/2 + A[1, 1]/2, sqrt(A[0, 0]**2 - 2*A[0, 0]*A[1, 1] + 4*A[0, 1]*A[1, 0] + A[1, 1]**2)/2 + A[0, 0]/2 + A[1, 1]/2) + raises(ValueError, lambda: JointEigenDistribution(Matrix([[1, 0], [2, 1]]))) + +def test_issue_19841(): + G1 = GUE('U', 2) + G2 = G1.xreplace({2: 2}) + assert G1.args == G2.args + + X = MatrixSymbol('X', 2, 2) + G = GSE('U', 2) + h_pspace = RandomMatrixPSpace('P', model=density(G)) + H = RandomMatrixSymbol('H', 2, 2, pspace=h_pspace) + H2 = RandomMatrixSymbol('H', 2, 2, pspace=None) + assert H.doit() == H + + assert (2*H).xreplace({H: X}) == 2*X + assert (2*H).xreplace({H2: X}) == 2*H + assert (2*H2).xreplace({H: X}) == 2*H2 + assert (2*H2).xreplace({H2: X}) == 2*X diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_rv.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_rv.py new file mode 100644 index 0000000000000000000000000000000000000000..185756300556f2fe70b76c402113ec2bb2501ef4 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_rv.py @@ -0,0 +1,441 @@ +from sympy.concrete.summations import Sum +from sympy.core.basic import Basic +from sympy.core.containers import Tuple +from sympy.core.function import Lambda +from sympy.core.numbers import (Rational, nan, oo, pi) +from sympy.core.relational import Eq +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.combinatorial.factorials import (FallingFactorial, binomial) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.functions.special.delta_functions import DiracDelta +from sympy.integrals.integrals import integrate +from sympy.logic.boolalg import (And, Or) +from sympy.matrices.dense import Matrix +from sympy.sets.sets import Interval +from sympy.tensor.indexed import Indexed +from sympy.stats import (Die, Normal, Exponential, FiniteRV, P, E, H, variance, + density, given, independent, dependent, where, pspace, GaussianUnitaryEnsemble, + random_symbols, sample, Geometric, factorial_moment, Binomial, Hypergeometric, + DiscreteUniform, Poisson, characteristic_function, moment_generating_function, + BernoulliProcess, Variance, Expectation, Probability, Covariance, covariance, cmoment, + moment, median) +from sympy.stats.rv import (IndependentProductPSpace, rs_swap, Density, NamedArgsMixin, + RandomSymbol, sample_iter, PSpace, is_random, RandomIndexedSymbol, RandomMatrixSymbol) +from sympy.testing.pytest import raises, skip, XFAIL, warns_deprecated_sympy +from sympy.external import import_module +from sympy.core.numbers import comp +from sympy.stats.frv_types import BernoulliDistribution +from sympy.core.symbol import Dummy +from sympy.functions.elementary.piecewise import Piecewise + +def test_where(): + X, Y = Die('X'), Die('Y') + Z = Normal('Z', 0, 1) + + assert where(Z**2 <= 1).set == Interval(-1, 1) + assert where(Z**2 <= 1).as_boolean() == Interval(-1, 1).as_relational(Z.symbol) + assert where(And(X > Y, Y > 4)).as_boolean() == And( + Eq(X.symbol, 6), Eq(Y.symbol, 5)) + + assert len(where(X < 3).set) == 2 + assert 1 in where(X < 3).set + + X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + assert where(And(X**2 <= 1, X >= 0)).set == Interval(0, 1) + XX = given(X, And(X**2 <= 1, X >= 0)) + assert XX.pspace.domain.set == Interval(0, 1) + assert XX.pspace.domain.as_boolean() == \ + And(0 <= X.symbol, X.symbol**2 <= 1, -oo < X.symbol, X.symbol < oo) + + with raises(TypeError): + XX = given(X, X + 3) + + +def test_random_symbols(): + X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + + assert set(random_symbols(2*X + 1)) == {X} + assert set(random_symbols(2*X + Y)) == {X, Y} + assert set(random_symbols(2*X + Y.symbol)) == {X} + assert set(random_symbols(2)) == set() + + +def test_characteristic_function(): + # Imports I from sympy + from sympy.core.numbers import I + X = Normal('X',0,1) + Y = DiscreteUniform('Y', [1,2,7]) + Z = Poisson('Z', 2) + t = symbols('_t') + P = Lambda(t, exp(-t**2/2)) + Q = Lambda(t, exp(7*t*I)/3 + exp(2*t*I)/3 + exp(t*I)/3) + R = Lambda(t, exp(2 * exp(t*I) - 2)) + + + assert characteristic_function(X).dummy_eq(P) + assert characteristic_function(Y).dummy_eq(Q) + assert characteristic_function(Z).dummy_eq(R) + + +def test_moment_generating_function(): + + X = Normal('X',0,1) + Y = DiscreteUniform('Y', [1,2,7]) + Z = Poisson('Z', 2) + t = symbols('_t') + P = Lambda(t, exp(t**2/2)) + Q = Lambda(t, (exp(7*t)/3 + exp(2*t)/3 + exp(t)/3)) + R = Lambda(t, exp(2 * exp(t) - 2)) + + + assert moment_generating_function(X).dummy_eq(P) + assert moment_generating_function(Y).dummy_eq(Q) + assert moment_generating_function(Z).dummy_eq(R) + +def test_sample_iter(): + + X = Normal('X',0,1) + Y = DiscreteUniform('Y', [1, 2, 7]) + Z = Poisson('Z', 2) + + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + expr = X**2 + 3 + iterator = sample_iter(expr) + + expr2 = Y**2 + 5*Y + 4 + iterator2 = sample_iter(expr2) + + expr3 = Z**3 + 4 + iterator3 = sample_iter(expr3) + + def is_iterator(obj): + if ( + hasattr(obj, '__iter__') and + (hasattr(obj, 'next') or + hasattr(obj, '__next__')) and + callable(obj.__iter__) and + obj.__iter__() is obj + ): + return True + else: + return False + assert is_iterator(iterator) + assert is_iterator(iterator2) + assert is_iterator(iterator3) + +def test_pspace(): + X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + x = Symbol('x') + + raises(ValueError, lambda: pspace(5 + 3)) + raises(ValueError, lambda: pspace(x < 1)) + assert pspace(X) == X.pspace + assert pspace(2*X + 1) == X.pspace + assert pspace(2*X + Y) == IndependentProductPSpace(Y.pspace, X.pspace) + +def test_rs_swap(): + X = Normal('x', 0, 1) + Y = Exponential('y', 1) + + XX = Normal('x', 0, 2) + YY = Normal('y', 0, 3) + + expr = 2*X + Y + assert expr.subs(rs_swap((X, Y), (YY, XX))) == 2*XX + YY + + +def test_RandomSymbol(): + + X = Normal('x', 0, 1) + Y = Normal('x', 0, 2) + assert X.symbol == Y.symbol + assert X != Y + + assert X.name == X.symbol.name + + X = Normal('lambda', 0, 1) # make sure we can use protected terms + X = Normal('Lambda', 0, 1) # make sure we can use SymPy terms + + +def test_RandomSymbol_diff(): + X = Normal('x', 0, 1) + assert (2*X).diff(X) + + +def test_random_symbol_no_pspace(): + x = RandomSymbol(Symbol('x')) + assert x.pspace == PSpace() + +def test_overlap(): + X = Normal('x', 0, 1) + Y = Normal('x', 0, 2) + + raises(ValueError, lambda: P(X > Y)) + + +def test_IndependentProductPSpace(): + X = Normal('X', 0, 1) + Y = Normal('Y', 0, 1) + px = X.pspace + py = Y.pspace + assert pspace(X + Y) == IndependentProductPSpace(px, py) + assert pspace(X + Y) == IndependentProductPSpace(py, px) + + +def test_E(): + assert E(5) == 5 + + +def test_H(): + X = Normal('X', 0, 1) + D = Die('D', sides = 4) + G = Geometric('G', 0.5) + assert H(X, X > 0) == -log(2)/2 + S.Half + log(pi)/2 + assert H(D, D > 2) == log(2) + assert comp(H(G).evalf().round(2), 1.39) + + +def test_Sample(): + X = Die('X', 6) + Y = Normal('Y', 0, 1) + z = Symbol('z', integer=True) + + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + assert sample(X) in [1, 2, 3, 4, 5, 6] + assert isinstance(sample(X + Y), float) + + assert P(X + Y > 0, Y < 0, numsamples=10).is_number + assert E(X + Y, numsamples=10).is_number + assert E(X**2 + Y, numsamples=10).is_number + assert E((X + Y)**2, numsamples=10).is_number + assert variance(X + Y, numsamples=10).is_number + + raises(TypeError, lambda: P(Y > z, numsamples=5)) + + assert P(sin(Y) <= 1, numsamples=10) == 1.0 + assert P(sin(Y) <= 1, cos(Y) < 1, numsamples=10) == 1.0 + + assert all(i in range(1, 7) for i in density(X, numsamples=10)) + assert all(i in range(4, 7) for i in density(X, X>3, numsamples=10)) + + numpy = import_module('numpy') + if not numpy: + skip('Numpy is not installed. Abort tests') + #Test Issue #21563: Output of sample must be a float or array + assert isinstance(sample(X), (numpy.int32, numpy.int64)) + assert isinstance(sample(Y), numpy.float64) + assert isinstance(sample(X, size=2), numpy.ndarray) + + with warns_deprecated_sympy(): + sample(X, numsamples=2) + +@XFAIL +def test_samplingE(): + scipy = import_module('scipy') + if not scipy: + skip('Scipy is not installed. Abort tests') + Y = Normal('Y', 0, 1) + z = Symbol('z', integer=True) + assert E(Sum(1/z**Y, (z, 1, oo)), Y > 2, numsamples=3).is_number + + +def test_given(): + X = Normal('X', 0, 1) + Y = Normal('Y', 0, 1) + A = given(X, True) + B = given(X, Y > 2) + + assert X == A == B + + +def test_factorial_moment(): + X = Poisson('X', 2) + Y = Binomial('Y', 2, S.Half) + Z = Hypergeometric('Z', 4, 2, 2) + assert factorial_moment(X, 2) == 4 + assert factorial_moment(Y, 2) == S.Half + assert factorial_moment(Z, 2) == Rational(1, 3) + + x, y, z, l = symbols('x y z l') + Y = Binomial('Y', 2, y) + Z = Hypergeometric('Z', 10, 2, 3) + assert factorial_moment(Y, l) == y**2*FallingFactorial( + 2, l) + 2*y*(1 - y)*FallingFactorial(1, l) + (1 - y)**2*\ + FallingFactorial(0, l) + assert factorial_moment(Z, l) == 7*FallingFactorial(0, l)/\ + 15 + 7*FallingFactorial(1, l)/15 + FallingFactorial(2, l)/15 + + +def test_dependence(): + X, Y = Die('X'), Die('Y') + assert independent(X, 2*Y) + assert not dependent(X, 2*Y) + + X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + assert independent(X, Y) + assert dependent(X, 2*X) + + # Create a dependency + XX, YY = given(Tuple(X, Y), Eq(X + Y, 3)) + assert dependent(XX, YY) + +def test_dependent_finite(): + X, Y = Die('X'), Die('Y') + # Dependence testing requires symbolic conditions which currently break + # finite random variables + assert dependent(X, Y + X) + + XX, YY = given(Tuple(X, Y), X + Y > 5) # Create a dependency + assert dependent(XX, YY) + + +def test_normality(): + X, Y = Normal('X', 0, 1), Normal('Y', 0, 1) + x = Symbol('x', real=True) + z = Symbol('z', real=True) + dens = density(X - Y, Eq(X + Y, z)) + + assert integrate(dens(x), (x, -oo, oo)) == 1 + + +def test_Density(): + X = Die('X', 6) + d = Density(X) + assert d.doit() == density(X) + +def test_NamedArgsMixin(): + class Foo(Basic, NamedArgsMixin): + _argnames = 'foo', 'bar' + + a = Foo(S(1), S(2)) + + assert a.foo == 1 + assert a.bar == 2 + + raises(AttributeError, lambda: a.baz) + + class Bar(Basic, NamedArgsMixin): + pass + + raises(AttributeError, lambda: Bar(S(1), S(2)).foo) + +def test_density_constant(): + assert density(3)(2) == 0 + assert density(3)(3) == DiracDelta(0) + +def test_cmoment_constant(): + assert variance(3) == 0 + assert cmoment(3, 3) == 0 + assert cmoment(3, 4) == 0 + x = Symbol('x') + assert variance(x) == 0 + assert cmoment(x, 15) == 0 + assert cmoment(x, 0) == 1 + +def test_moment_constant(): + assert moment(3, 0) == 1 + assert moment(3, 1) == 3 + assert moment(3, 2) == 9 + x = Symbol('x') + assert moment(x, 2) == x**2 + +def test_median_constant(): + assert median(3) == 3 + x = Symbol('x') + assert median(x) == x + +def test_real(): + x = Normal('x', 0, 1) + assert x.is_real + + +def test_issue_10052(): + X = Exponential('X', 3) + assert P(X < oo) == 1 + assert P(X > oo) == 0 + assert P(X < 2, X > oo) == 0 + assert P(X < oo, X > oo) == 0 + assert P(X < oo, X > 2) == 1 + assert P(X < 3, X == 2) == 0 + raises(ValueError, lambda: P(1)) + raises(ValueError, lambda: P(X < 1, 2)) + +def test_issue_11934(): + density = {0: .5, 1: .5} + X = FiniteRV('X', density) + assert E(X) == 0.5 + assert P( X>= 2) == 0 + +def test_issue_8129(): + X = Exponential('X', 4) + assert P(X >= X) == 1 + assert P(X > X) == 0 + assert P(X > X+1) == 0 + +def test_issue_12237(): + X = Normal('X', 0, 1) + Y = Normal('Y', 0, 1) + U = P(X > 0, X) + V = P(Y < 0, X) + W = P(X + Y > 0, X) + assert W == P(X + Y > 0, X) + assert U == BernoulliDistribution(S.Half, S.Zero, S.One) + assert V == S.Half + +def test_is_random(): + X = Normal('X', 0, 1) + Y = Normal('Y', 0, 1) + a, b = symbols('a, b') + G = GaussianUnitaryEnsemble('U', 2) + B = BernoulliProcess('B', 0.9) + assert not is_random(a) + assert not is_random(a + b) + assert not is_random(a * b) + assert not is_random(Matrix([a**2, b**2])) + assert is_random(X) + assert is_random(X**2 + Y) + assert is_random(Y + b**2) + assert is_random(Y > 5) + assert is_random(B[3] < 1) + assert is_random(G) + assert is_random(X * Y * B[1]) + assert is_random(Matrix([[X, B[2]], [G, Y]])) + assert is_random(Eq(X, 4)) + +def test_issue_12283(): + x = symbols('x') + X = RandomSymbol(x) + Y = RandomSymbol('Y') + Z = RandomMatrixSymbol('Z', 2, 1) + W = RandomMatrixSymbol('W', 2, 1) + RI = RandomIndexedSymbol(Indexed('RI', 3)) + assert pspace(Z) == PSpace() + assert pspace(RI) == PSpace() + assert pspace(X) == PSpace() + assert E(X) == Expectation(X) + assert P(Y > 3) == Probability(Y > 3) + assert variance(X) == Variance(X) + assert variance(RI) == Variance(RI) + assert covariance(X, Y) == Covariance(X, Y) + assert covariance(W, Z) == Covariance(W, Z) + +def test_issue_6810(): + X = Die('X', 6) + Y = Normal('Y', 0, 1) + assert P(Eq(X, 2)) == S(1)/6 + assert P(Eq(Y, 0)) == 0 + assert P(Or(X > 2, X < 3)) == 1 + assert P(And(X > 3, X > 2)) == S(1)/2 + +def test_issue_20286(): + n, p = symbols('n p') + B = Binomial('B', n, p) + k = Dummy('k', integer = True) + eq = Sum(Piecewise((-p**k*(1 - p)**(-k + n)*log(p**k*(1 - p)**(-k + n)*binomial(n, k))*binomial(n, k), (k >= 0) & (k <= n)), (nan, True)), (k, 0, n)) + assert eq.dummy_eq(H(B)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_stochastic_process.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_stochastic_process.py new file mode 100644 index 0000000000000000000000000000000000000000..3e42ffc8632240b1d85a774467a057e9857c567c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_stochastic_process.py @@ -0,0 +1,763 @@ +from sympy.concrete.summations import Sum +from sympy.core.containers import Tuple +from sympy.core.function import Lambda +from sympy.core.numbers import (Float, Rational, oo, pi) +from sympy.core.relational import (Eq, Ge, Gt, Le, Lt, Ne) +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.functions.combinatorial.factorials import factorial +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.integers import ceiling +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.piecewise import Piecewise +from sympy.functions.special.error_functions import erf +from sympy.functions.special.gamma_functions import (gamma, lowergamma) +from sympy.logic.boolalg import (And, Not) +from sympy.matrices.dense import Matrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.immutable import ImmutableMatrix +from sympy.sets.contains import Contains +from sympy.sets.fancysets import Range +from sympy.sets.sets import (FiniteSet, Interval) +from sympy.stats import (DiscreteMarkovChain, P, TransitionMatrixOf, E, + StochasticStateSpaceOf, variance, ContinuousMarkovChain, + BernoulliProcess, PoissonProcess, WienerProcess, + GammaProcess, sample_stochastic_process) +from sympy.stats.joint_rv import JointDistribution +from sympy.stats.joint_rv_types import JointDistributionHandmade +from sympy.stats.rv import RandomIndexedSymbol +from sympy.stats.symbolic_probability import Probability, Expectation +from sympy.testing.pytest import (raises, skip, ignore_warnings, + warns_deprecated_sympy) +from sympy.external import import_module +from sympy.stats.frv_types import BernoulliDistribution +from sympy.stats.drv_types import PoissonDistribution +from sympy.stats.crv_types import NormalDistribution, GammaDistribution +from sympy.core.symbol import Str + + +def test_DiscreteMarkovChain(): + + # pass only the name + X = DiscreteMarkovChain("X") + assert isinstance(X.state_space, Range) + assert X.index_set == S.Naturals0 + assert isinstance(X.transition_probabilities, MatrixSymbol) + t = symbols('t', positive=True, integer=True) + assert isinstance(X[t], RandomIndexedSymbol) + assert E(X[0]) == Expectation(X[0]) + raises(TypeError, lambda: DiscreteMarkovChain(1)) + raises(NotImplementedError, lambda: X(t)) + raises(NotImplementedError, lambda: X.communication_classes()) + raises(NotImplementedError, lambda: X.canonical_form()) + raises(NotImplementedError, lambda: X.decompose()) + + nz = Symbol('n', integer=True) + TZ = MatrixSymbol('M', nz, nz) + SZ = Range(nz) + YZ = DiscreteMarkovChain('Y', SZ, TZ) + assert P(Eq(YZ[2], 1), Eq(YZ[1], 0)) == TZ[0, 1] + + raises(ValueError, lambda: sample_stochastic_process(t)) + raises(ValueError, lambda: next(sample_stochastic_process(X))) + # pass name and state_space + # any hashable object should be a valid state + # states should be valid as a tuple/set/list/Tuple/Range + sym, rainy, cloudy, sunny = symbols('a Rainy Cloudy Sunny', real=True) + state_spaces = [(1, 2, 3), [Str('Hello'), sym, DiscreteMarkovChain("Y", (1,2,3))], + Tuple(S(1), exp(sym), Str('World'), sympify=False), Range(-1, 5, 2), + [rainy, cloudy, sunny]] + chains = [DiscreteMarkovChain("Y", state_space) for state_space in state_spaces] + + for i, Y in enumerate(chains): + assert isinstance(Y.transition_probabilities, MatrixSymbol) + assert Y.state_space == state_spaces[i] or Y.state_space == FiniteSet(*state_spaces[i]) + assert Y.number_of_states == 3 + + with ignore_warnings(UserWarning): # TODO: Restore tests once warnings are removed + assert P(Eq(Y[2], 1), Eq(Y[0], 2), evaluate=False) == Probability(Eq(Y[2], 1), Eq(Y[0], 2)) + assert E(Y[0]) == Expectation(Y[0]) + + raises(ValueError, lambda: next(sample_stochastic_process(Y))) + + raises(TypeError, lambda: DiscreteMarkovChain("Y", {1: 1})) + Y = DiscreteMarkovChain("Y", Range(1, t, 2)) + assert Y.number_of_states == ceiling((t-1)/2) + + # pass name and transition_probabilities + chains = [DiscreteMarkovChain("Y", trans_probs=Matrix([])), + DiscreteMarkovChain("Y", trans_probs=Matrix([[0, 1], [1, 0]])), + DiscreteMarkovChain("Y", trans_probs=Matrix([[pi, 1-pi], [sym, 1-sym]]))] + for Z in chains: + assert Z.number_of_states == Z.transition_probabilities.shape[0] + assert isinstance(Z.transition_probabilities, ImmutableMatrix) + + # pass name, state_space and transition_probabilities + T = Matrix([[0.5, 0.2, 0.3],[0.2, 0.5, 0.3],[0.2, 0.3, 0.5]]) + TS = MatrixSymbol('T', 3, 3) + Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + YS = DiscreteMarkovChain("Y", ['One', 'Two', 3], TS) + assert Y.joint_distribution(1, Y[2], 3) == JointDistribution(Y[1], Y[2], Y[3]) + raises(ValueError, lambda: Y.joint_distribution(Y[1].symbol, Y[2].symbol)) + assert P(Eq(Y[3], 2), Eq(Y[1], 1)).round(2) == Float(0.36, 2) + assert (P(Eq(YS[3], 2), Eq(YS[1], 1)) - + (TS[0, 2]*TS[1, 0] + TS[1, 1]*TS[1, 2] + TS[1, 2]*TS[2, 2])).simplify() == 0 + assert P(Eq(YS[1], 1), Eq(YS[2], 2)) == Probability(Eq(YS[1], 1)) + assert P(Eq(YS[3], 3), Eq(YS[1], 1)) == TS[0, 2]*TS[1, 0] + TS[1, 1]*TS[1, 2] + TS[1, 2]*TS[2, 2] + TO = Matrix([[0.25, 0.75, 0],[0, 0.25, 0.75],[0.75, 0, 0.25]]) + assert P(Eq(Y[3], 2), Eq(Y[1], 1) & TransitionMatrixOf(Y, TO)).round(3) == Float(0.375, 3) + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + assert E(Y[3], evaluate=False) == Expectation(Y[3]) + assert E(Y[3], Eq(Y[2], 1)).round(2) == Float(1.1, 3) + TSO = MatrixSymbol('T', 4, 4) + raises(ValueError, lambda: str(P(Eq(YS[3], 2), Eq(YS[1], 1) & TransitionMatrixOf(YS, TSO)))) + raises(TypeError, lambda: DiscreteMarkovChain("Z", [0, 1, 2], symbols('M'))) + raises(ValueError, lambda: DiscreteMarkovChain("Z", [0, 1, 2], MatrixSymbol('T', 3, 4))) + raises(ValueError, lambda: E(Y[3], Eq(Y[2], 6))) + raises(ValueError, lambda: E(Y[2], Eq(Y[3], 1))) + + + # extended tests for probability queries + TO1 = Matrix([[Rational(1, 4), Rational(3, 4), 0],[Rational(1, 3), Rational(1, 3), Rational(1, 3)],[0, Rational(1, 4), Rational(3, 4)]]) + assert P(And(Eq(Y[2], 1), Eq(Y[1], 1), Eq(Y[0], 0)), + Eq(Probability(Eq(Y[0], 0)), Rational(1, 4)) & TransitionMatrixOf(Y, TO1)) == Rational(1, 16) + assert P(And(Eq(Y[2], 1), Eq(Y[1], 1), Eq(Y[0], 0)), TransitionMatrixOf(Y, TO1)) == \ + Probability(Eq(Y[0], 0))/4 + assert P(Lt(X[1], 2) & Gt(X[1], 0), Eq(X[0], 2) & + StochasticStateSpaceOf(X, [0, 1, 2]) & TransitionMatrixOf(X, TO1)) == Rational(1, 4) + assert P(Lt(X[1], 2) & Gt(X[1], 0), Eq(X[0], 2) & + StochasticStateSpaceOf(X, [S(0), '0', 1]) & TransitionMatrixOf(X, TO1)) == Rational(1, 4) + assert P(Ne(X[1], 2) & Ne(X[1], 1), Eq(X[0], 2) & + StochasticStateSpaceOf(X, [0, 1, 2]) & TransitionMatrixOf(X, TO1)) is S.Zero + assert P(Ne(X[1], 2) & Ne(X[1], 1), Eq(X[0], 2) & + StochasticStateSpaceOf(X, [S(0), '0', 1]) & TransitionMatrixOf(X, TO1)) is S.Zero + assert P(And(Eq(Y[2], 1), Eq(Y[1], 1), Eq(Y[0], 0)), Eq(Y[1], 1)) == 0.1*Probability(Eq(Y[0], 0)) + + # testing properties of Markov chain + TO2 = Matrix([[S.One, 0, 0],[Rational(1, 3), Rational(1, 3), Rational(1, 3)],[0, Rational(1, 4), Rational(3, 4)]]) + TO3 = Matrix([[Rational(1, 4), Rational(3, 4), 0],[Rational(1, 3), Rational(1, 3), Rational(1, 3)], [0, Rational(1, 4), Rational(3, 4)]]) + Y2 = DiscreteMarkovChain('Y', trans_probs=TO2) + Y3 = DiscreteMarkovChain('Y', trans_probs=TO3) + assert Y3.fundamental_matrix() == ImmutableMatrix([[176, 81, -132], [36, 141, -52], [-44, -39, 208]])/125 + assert Y2.is_absorbing_chain() == True + assert Y3.is_absorbing_chain() == False + assert Y2.canonical_form() == ([0, 1, 2], TO2) + assert Y3.canonical_form() == ([0, 1, 2], TO3) + assert Y2.decompose() == ([0, 1, 2], TO2[0:1, 0:1], TO2[1:3, 0:1], TO2[1:3, 1:3]) + assert Y3.decompose() == ([0, 1, 2], TO3, Matrix(0, 3, []), Matrix(0, 0, [])) + TO4 = Matrix([[Rational(1, 5), Rational(2, 5), Rational(2, 5)], [Rational(1, 10), S.Half, Rational(2, 5)], [Rational(3, 5), Rational(3, 10), Rational(1, 10)]]) + Y4 = DiscreteMarkovChain('Y', trans_probs=TO4) + w = ImmutableMatrix([[Rational(11, 39), Rational(16, 39), Rational(4, 13)]]) + assert Y4.limiting_distribution == w + assert Y4.is_regular() == True + assert Y4.is_ergodic() == True + TS1 = MatrixSymbol('T', 3, 3) + Y5 = DiscreteMarkovChain('Y', trans_probs=TS1) + assert Y5.limiting_distribution(w, TO4).doit() == True + assert Y5.stationary_distribution(condition_set=True).subs(TS1, TO4).contains(w).doit() == S.true + TO6 = Matrix([[S.One, 0, 0, 0, 0],[S.Half, 0, S.Half, 0, 0],[0, S.Half, 0, S.Half, 0], [0, 0, S.Half, 0, S.Half], [0, 0, 0, 0, 1]]) + Y6 = DiscreteMarkovChain('Y', trans_probs=TO6) + assert Y6.fundamental_matrix() == ImmutableMatrix([[Rational(3, 2), S.One, S.Half], [S.One, S(2), S.One], [S.Half, S.One, Rational(3, 2)]]) + assert Y6.absorbing_probabilities() == ImmutableMatrix([[Rational(3, 4), Rational(1, 4)], [S.Half, S.Half], [Rational(1, 4), Rational(3, 4)]]) + with warns_deprecated_sympy(): + Y6.absorbing_probabilites() + TO7 = Matrix([[Rational(1, 2), Rational(1, 4), Rational(1, 4)], [Rational(1, 2), 0, Rational(1, 2)], [Rational(1, 4), Rational(1, 4), Rational(1, 2)]]) + Y7 = DiscreteMarkovChain('Y', trans_probs=TO7) + assert Y7.is_absorbing_chain() == False + assert Y7.fundamental_matrix() == ImmutableMatrix([[Rational(86, 75), Rational(1, 25), Rational(-14, 75)], + [Rational(2, 25), Rational(21, 25), Rational(2, 25)], + [Rational(-14, 75), Rational(1, 25), Rational(86, 75)]]) + + # test for zero-sized matrix functionality + X = DiscreteMarkovChain('X', trans_probs=Matrix([])) + assert X.number_of_states == 0 + assert X.stationary_distribution() == Matrix([[]]) + assert X.communication_classes() == [] + assert X.canonical_form() == ([], Matrix([])) + assert X.decompose() == ([], Matrix([]), Matrix([]), Matrix([])) + assert X.is_regular() == False + assert X.is_ergodic() == False + + # test communication_class + # see https://drive.google.com/drive/folders/1HbxLlwwn2b3U8Lj7eb_ASIUb5vYaNIjg?usp=sharing + # tutorial 2.pdf + TO7 = Matrix([[0, 5, 5, 0, 0], + [0, 0, 0, 10, 0], + [5, 0, 5, 0, 0], + [0, 10, 0, 0, 0], + [0, 3, 0, 3, 4]])/10 + Y7 = DiscreteMarkovChain('Y', trans_probs=TO7) + tuples = Y7.communication_classes() + classes, recurrence, periods = list(zip(*tuples)) + assert classes == ([1, 3], [0, 2], [4]) + assert recurrence == (True, False, False) + assert periods == (2, 1, 1) + + TO8 = Matrix([[0, 0, 0, 10, 0, 0], + [5, 0, 5, 0, 0, 0], + [0, 4, 0, 0, 0, 6], + [10, 0, 0, 0, 0, 0], + [0, 10, 0, 0, 0, 0], + [0, 0, 0, 5, 5, 0]])/10 + Y8 = DiscreteMarkovChain('Y', trans_probs=TO8) + tuples = Y8.communication_classes() + classes, recurrence, periods = list(zip(*tuples)) + assert classes == ([0, 3], [1, 2, 5, 4]) + assert recurrence == (True, False) + assert periods == (2, 2) + + TO9 = Matrix([[2, 0, 0, 3, 0, 0, 3, 2, 0, 0], + [0, 10, 0, 0, 0, 0, 0, 0, 0, 0], + [0, 2, 2, 0, 0, 0, 0, 0, 3, 3], + [0, 0, 0, 3, 0, 0, 6, 1, 0, 0], + [0, 0, 0, 0, 5, 5, 0, 0, 0, 0], + [0, 0, 0, 0, 0, 10, 0, 0, 0, 0], + [4, 0, 0, 5, 0, 0, 1, 0, 0, 0], + [2, 0, 0, 4, 0, 0, 2, 2, 0, 0], + [3, 0, 1, 0, 0, 0, 0, 0, 4, 2], + [0, 0, 4, 0, 0, 0, 0, 0, 3, 3]])/10 + Y9 = DiscreteMarkovChain('Y', trans_probs=TO9) + tuples = Y9.communication_classes() + classes, recurrence, periods = list(zip(*tuples)) + assert classes == ([0, 3, 6, 7], [1], [2, 8, 9], [5], [4]) + assert recurrence == (True, True, False, True, False) + assert periods == (1, 1, 1, 1, 1) + + # test canonical form + # see https://web.archive.org/web/20201230182007/https://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/Chapter11.pdf + # example 11.13 + T = Matrix([[1, 0, 0, 0, 0], + [S(1) / 2, 0, S(1) / 2, 0, 0], + [0, S(1) / 2, 0, S(1) / 2, 0], + [0, 0, S(1) / 2, 0, S(1) / 2], + [0, 0, 0, 0, S(1)]]) + DW = DiscreteMarkovChain('DW', [0, 1, 2, 3, 4], T) + states, A, B, C = DW.decompose() + assert states == [0, 4, 1, 2, 3] + assert A == Matrix([[1, 0], [0, 1]]) + assert B == Matrix([[S(1)/2, 0], [0, 0], [0, S(1)/2]]) + assert C == Matrix([[0, S(1)/2, 0], [S(1)/2, 0, S(1)/2], [0, S(1)/2, 0]]) + states, new_matrix = DW.canonical_form() + assert states == [0, 4, 1, 2, 3] + assert new_matrix == Matrix([[1, 0, 0, 0, 0], + [0, 1, 0, 0, 0], + [S(1)/2, 0, 0, S(1)/2, 0], + [0, 0, S(1)/2, 0, S(1)/2], + [0, S(1)/2, 0, S(1)/2, 0]]) + + # test regular and ergodic + # https://web.archive.org/web/20201230182007/https://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/Chapter11.pdf + T = Matrix([[0, 4, 0, 0, 0], + [1, 0, 3, 0, 0], + [0, 2, 0, 2, 0], + [0, 0, 3, 0, 1], + [0, 0, 0, 4, 0]])/4 + X = DiscreteMarkovChain('X', trans_probs=T) + assert not X.is_regular() + assert X.is_ergodic() + T = Matrix([[0, 1], [1, 0]]) + X = DiscreteMarkovChain('X', trans_probs=T) + assert not X.is_regular() + assert X.is_ergodic() + # http://www.math.wisc.edu/~valko/courses/331/MC2.pdf + T = Matrix([[2, 1, 1], + [2, 0, 2], + [1, 1, 2]])/4 + X = DiscreteMarkovChain('X', trans_probs=T) + assert X.is_regular() + assert X.is_ergodic() + # https://docs.ufpr.br/~lucambio/CE222/1S2014/Kemeny-Snell1976.pdf + T = Matrix([[1, 1], [1, 1]])/2 + X = DiscreteMarkovChain('X', trans_probs=T) + assert X.is_regular() + assert X.is_ergodic() + + # test is_absorbing_chain + T = Matrix([[0, 1, 0], + [1, 0, 0], + [0, 0, 1]]) + X = DiscreteMarkovChain('X', trans_probs=T) + assert not X.is_absorbing_chain() + # https://en.wikipedia.org/wiki/Absorbing_Markov_chain + T = Matrix([[1, 1, 0, 0], + [0, 1, 1, 0], + [1, 0, 0, 1], + [0, 0, 0, 2]])/2 + X = DiscreteMarkovChain('X', trans_probs=T) + assert X.is_absorbing_chain() + T = Matrix([[2, 0, 0, 0, 0], + [1, 0, 1, 0, 0], + [0, 1, 0, 1, 0], + [0, 0, 1, 0, 1], + [0, 0, 0, 0, 2]])/2 + X = DiscreteMarkovChain('X', trans_probs=T) + assert X.is_absorbing_chain() + + # test custom state space + Y10 = DiscreteMarkovChain('Y', [1, 2, 3], TO2) + tuples = Y10.communication_classes() + classes, recurrence, periods = list(zip(*tuples)) + assert classes == ([1], [2, 3]) + assert recurrence == (True, False) + assert periods == (1, 1) + assert Y10.canonical_form() == ([1, 2, 3], TO2) + assert Y10.decompose() == ([1, 2, 3], TO2[0:1, 0:1], TO2[1:3, 0:1], TO2[1:3, 1:3]) + + # testing miscellaneous queries + T = Matrix([[S.Half, Rational(1, 4), Rational(1, 4)], + [Rational(1, 3), 0, Rational(2, 3)], + [S.Half, S.Half, 0]]) + X = DiscreteMarkovChain('X', [0, 1, 2], T) + assert P(Eq(X[1], 2) & Eq(X[2], 1) & Eq(X[3], 0), + Eq(P(Eq(X[1], 0)), Rational(1, 4)) & Eq(P(Eq(X[1], 1)), Rational(1, 4))) == Rational(1, 12) + assert P(Eq(X[2], 1) | Eq(X[2], 2), Eq(X[1], 1)) == Rational(2, 3) + assert P(Eq(X[2], 1) & Eq(X[2], 2), Eq(X[1], 1)) is S.Zero + assert P(Ne(X[2], 2), Eq(X[1], 1)) == Rational(1, 3) + assert E(X[1]**2, Eq(X[0], 1)) == Rational(8, 3) + assert variance(X[1], Eq(X[0], 1)) == Rational(8, 9) + raises(ValueError, lambda: E(X[1], Eq(X[2], 1))) + raises(ValueError, lambda: DiscreteMarkovChain('X', [0, 1], T)) + + # testing miscellaneous queries with different state space + X = DiscreteMarkovChain('X', ['A', 'B', 'C'], T) + assert P(Eq(X[1], 2) & Eq(X[2], 1) & Eq(X[3], 0), + Eq(P(Eq(X[1], 0)), Rational(1, 4)) & Eq(P(Eq(X[1], 1)), Rational(1, 4))) == Rational(1, 12) + assert P(Eq(X[2], 1) | Eq(X[2], 2), Eq(X[1], 1)) == Rational(2, 3) + assert P(Eq(X[2], 1) & Eq(X[2], 2), Eq(X[1], 1)) is S.Zero + assert P(Ne(X[2], 2), Eq(X[1], 1)) == Rational(1, 3) + a = X.state_space.args[0] + c = X.state_space.args[2] + assert (E(X[1] ** 2, Eq(X[0], 1)) - (a**2/3 + 2*c**2/3)).simplify() == 0 + assert (variance(X[1], Eq(X[0], 1)) - (2*(-a/3 + c/3)**2/3 + (2*a/3 - 2*c/3)**2/3)).simplify() == 0 + raises(ValueError, lambda: E(X[1], Eq(X[2], 1))) + + #testing queries with multiple RandomIndexedSymbols + T = Matrix([[Rational(5, 10), Rational(3, 10), Rational(2, 10)], [Rational(2, 10), Rational(7, 10), Rational(1, 10)], [Rational(3, 10), Rational(3, 10), Rational(4, 10)]]) + Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + assert P(Eq(Y[7], Y[5]), Eq(Y[2], 0)).round(5) == Float(0.44428, 5) + assert P(Gt(Y[3], Y[1]), Eq(Y[0], 0)).round(2) == Float(0.36, 2) + assert P(Le(Y[5], Y[10]), Eq(Y[4], 2)).round(6) == Float(0.583120, 6) + assert Float(P(Eq(Y[10], Y[5]), Eq(Y[4], 1)), 14) == Float(1 - P(Ne(Y[10], Y[5]), Eq(Y[4], 1)), 14) + assert Float(P(Gt(Y[8], Y[9]), Eq(Y[3], 2)), 14) == Float(1 - P(Le(Y[8], Y[9]), Eq(Y[3], 2)), 14) + assert Float(P(Lt(Y[1], Y[4]), Eq(Y[0], 0)), 14) == Float(1 - P(Ge(Y[1], Y[4]), Eq(Y[0], 0)), 14) + assert P(Eq(Y[5], Y[10]), Eq(Y[2], 1)) == P(Eq(Y[10], Y[5]), Eq(Y[2], 1)) + assert P(Gt(Y[1], Y[2]), Eq(Y[0], 1)) == P(Lt(Y[2], Y[1]), Eq(Y[0], 1)) + assert P(Ge(Y[7], Y[6]), Eq(Y[4], 1)) == P(Le(Y[6], Y[7]), Eq(Y[4], 1)) + + #test symbolic queries + a, b, c, d = symbols('a b c d') + T = Matrix([[Rational(1, 10), Rational(4, 10), Rational(5, 10)], [Rational(3, 10), Rational(4, 10), Rational(3, 10)], [Rational(7, 10), Rational(2, 10), Rational(1, 10)]]) + Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + query = P(Eq(Y[a], b), Eq(Y[c], d)) + assert query.subs({a:10, b:2, c:5, d:1}).evalf().round(4) == P(Eq(Y[10], 2), Eq(Y[5], 1)).round(4) + assert query.subs({a:15, b:0, c:10, d:1}).evalf().round(4) == P(Eq(Y[15], 0), Eq(Y[10], 1)).round(4) + query_gt = P(Gt(Y[a], b), Eq(Y[c], d)) + query_le = P(Le(Y[a], b), Eq(Y[c], d)) + assert query_gt.subs({a:5, b:2, c:1, d:0}).evalf() + query_le.subs({a:5, b:2, c:1, d:0}).evalf() == 1.0 + query_ge = P(Ge(Y[a], b), Eq(Y[c], d)) + query_lt = P(Lt(Y[a], b), Eq(Y[c], d)) + assert query_ge.subs({a:4, b:1, c:0, d:2}).evalf() + query_lt.subs({a:4, b:1, c:0, d:2}).evalf() == 1.0 + + #test issue 20078 + assert (2*Y[1] + 3*Y[1]).simplify() == 5*Y[1] + assert (2*Y[1] - 3*Y[1]).simplify() == -Y[1] + assert (2*(0.25*Y[1])).simplify() == 0.5*Y[1] + assert ((2*Y[1]) * (0.25*Y[1])).simplify() == 0.5*Y[1]**2 + assert (Y[1]**2 + Y[1]**3).simplify() == (Y[1] + 1)*Y[1]**2 + +def test_sample_stochastic_process(): + if not import_module('scipy'): + skip('SciPy Not installed. Skip sampling tests') + import random + random.seed(0) + numpy = import_module('numpy') + if numpy: + numpy.random.seed(0) # scipy uses numpy to sample so to set its seed + T = Matrix([[0.5, 0.2, 0.3],[0.2, 0.5, 0.3],[0.2, 0.3, 0.5]]) + Y = DiscreteMarkovChain("Y", [0, 1, 2], T) + for samps in range(10): + assert next(sample_stochastic_process(Y)) in Y.state_space + Z = DiscreteMarkovChain("Z", ['1', 1, 0], T) + for samps in range(10): + assert next(sample_stochastic_process(Z)) in Z.state_space + + T = Matrix([[S.Half, Rational(1, 4), Rational(1, 4)], + [Rational(1, 3), 0, Rational(2, 3)], + [S.Half, S.Half, 0]]) + X = DiscreteMarkovChain('X', [0, 1, 2], T) + for samps in range(10): + assert next(sample_stochastic_process(X)) in X.state_space + W = DiscreteMarkovChain('W', [1, pi, oo], T) + for samps in range(10): + assert next(sample_stochastic_process(W)) in W.state_space + + +def test_ContinuousMarkovChain(): + T1 = Matrix([[S(-2), S(2), S.Zero], + [S.Zero, S.NegativeOne, S.One], + [Rational(3, 2), Rational(3, 2), S(-3)]]) + C1 = ContinuousMarkovChain('C', [0, 1, 2], T1) + assert C1.limiting_distribution() == ImmutableMatrix([[Rational(3, 19), Rational(12, 19), Rational(4, 19)]]) + + T2 = Matrix([[-S.One, S.One, S.Zero], [S.One, -S.One, S.Zero], [S.Zero, S.One, -S.One]]) + C2 = ContinuousMarkovChain('C', [0, 1, 2], T2) + A, t = C2.generator_matrix, symbols('t', positive=True) + assert C2.transition_probabilities(A)(t) == Matrix([[S.Half + exp(-2*t)/2, S.Half - exp(-2*t)/2, 0], + [S.Half - exp(-2*t)/2, S.Half + exp(-2*t)/2, 0], + [S.Half - exp(-t) + exp(-2*t)/2, S.Half - exp(-2*t)/2, exp(-t)]]) + with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed + assert P(Eq(C2(1), 1), Eq(C2(0), 1), evaluate=False) == Probability(Eq(C2(1), 1), Eq(C2(0), 1)) + assert P(Eq(C2(1), 1), Eq(C2(0), 1)) == exp(-2)/2 + S.Half + assert P(Eq(C2(1), 0) & Eq(C2(2), 1) & Eq(C2(3), 1), + Eq(P(Eq(C2(1), 0)), S.Half)) == (Rational(1, 4) - exp(-2)/4)*(exp(-2)/2 + S.Half) + assert P(Not(Eq(C2(1), 0) & Eq(C2(2), 1) & Eq(C2(3), 2)) | + (Eq(C2(1), 0) & Eq(C2(2), 1) & Eq(C2(3), 2)), + Eq(P(Eq(C2(1), 0)), Rational(1, 4)) & Eq(P(Eq(C2(1), 1)), Rational(1, 4))) is S.One + assert E(C2(Rational(3, 2)), Eq(C2(0), 2)) == -exp(-3)/2 + 2*exp(Rational(-3, 2)) + S.Half + assert variance(C2(Rational(3, 2)), Eq(C2(0), 1)) == ((S.Half - exp(-3)/2)**2*(exp(-3)/2 + S.Half) + + (Rational(-1, 2) - exp(-3)/2)**2*(S.Half - exp(-3)/2)) + raises(KeyError, lambda: P(Eq(C2(1), 0), Eq(P(Eq(C2(1), 1)), S.Half))) + assert P(Eq(C2(1), 0), Eq(P(Eq(C2(5), 1)), S.Half)) == Probability(Eq(C2(1), 0)) + TS1 = MatrixSymbol('G', 3, 3) + CS1 = ContinuousMarkovChain('C', [0, 1, 2], TS1) + A = CS1.generator_matrix + assert CS1.transition_probabilities(A)(t) == exp(t*A) + + C3 = ContinuousMarkovChain('C', [Symbol('0'), Symbol('1'), Symbol('2')], T2) + assert P(Eq(C3(1), 1), Eq(C3(0), 1)) == exp(-2)/2 + S.Half + assert P(Eq(C3(1), Symbol('1')), Eq(C3(0), Symbol('1'))) == exp(-2)/2 + S.Half + + #test probability queries + G = Matrix([[-S(1), Rational(1, 10), Rational(9, 10)], [Rational(2, 5), -S(1), Rational(3, 5)], [Rational(1, 2), Rational(1, 2), -S(1)]]) + C = ContinuousMarkovChain('C', state_space=[0, 1, 2], gen_mat=G) + assert P(Eq(C(7.385), C(3.19)), Eq(C(0.862), 0)).round(5) == Float(0.35469, 5) + assert P(Gt(C(98.715), C(19.807)), Eq(C(11.314), 2)).round(5) == Float(0.32452, 5) + assert P(Le(C(5.9), C(10.112)), Eq(C(4), 1)).round(6) == Float(0.675214, 6) + assert Float(P(Eq(C(7.32), C(2.91)), Eq(C(2.63), 1)), 14) == Float(1 - P(Ne(C(7.32), C(2.91)), Eq(C(2.63), 1)), 14) + assert Float(P(Gt(C(3.36), C(1.101)), Eq(C(0.8), 2)), 14) == Float(1 - P(Le(C(3.36), C(1.101)), Eq(C(0.8), 2)), 14) + assert Float(P(Lt(C(4.9), C(2.79)), Eq(C(1.61), 0)), 14) == Float(1 - P(Ge(C(4.9), C(2.79)), Eq(C(1.61), 0)), 14) + assert P(Eq(C(5.243), C(10.912)), Eq(C(2.174), 1)) == P(Eq(C(10.912), C(5.243)), Eq(C(2.174), 1)) + assert P(Gt(C(2.344), C(9.9)), Eq(C(1.102), 1)) == P(Lt(C(9.9), C(2.344)), Eq(C(1.102), 1)) + assert P(Ge(C(7.87), C(1.008)), Eq(C(0.153), 1)) == P(Le(C(1.008), C(7.87)), Eq(C(0.153), 1)) + + #test symbolic queries + a, b, c, d = symbols('a b c d') + query = P(Eq(C(a), b), Eq(C(c), d)) + assert query.subs({a:3.65, b:2, c:1.78, d:1}).evalf().round(10) == P(Eq(C(3.65), 2), Eq(C(1.78), 1)).round(10) + query_gt = P(Gt(C(a), b), Eq(C(c), d)) + query_le = P(Le(C(a), b), Eq(C(c), d)) + assert query_gt.subs({a:13.2, b:0, c:3.29, d:2}).evalf() + query_le.subs({a:13.2, b:0, c:3.29, d:2}).evalf() == 1.0 + query_ge = P(Ge(C(a), b), Eq(C(c), d)) + query_lt = P(Lt(C(a), b), Eq(C(c), d)) + assert query_ge.subs({a:7.43, b:1, c:1.45, d:0}).evalf() + query_lt.subs({a:7.43, b:1, c:1.45, d:0}).evalf() == 1.0 + + #test issue 20078 + assert (2*C(1) + 3*C(1)).simplify() == 5*C(1) + assert (2*C(1) - 3*C(1)).simplify() == -C(1) + assert (2*(0.25*C(1))).simplify() == 0.5*C(1) + assert (2*C(1) * 0.25*C(1)).simplify() == 0.5*C(1)**2 + assert (C(1)**2 + C(1)**3).simplify() == (C(1) + 1)*C(1)**2 + +def test_BernoulliProcess(): + + B = BernoulliProcess("B", p=0.6, success=1, failure=0) + assert B.state_space == FiniteSet(0, 1) + assert B.index_set == S.Naturals0 + assert B.success == 1 + assert B.failure == 0 + + X = BernoulliProcess("X", p=Rational(1,3), success='H', failure='T') + assert X.state_space == FiniteSet('H', 'T') + H, T = symbols("H,T") + assert E(X[1]+X[2]*X[3]) == H**2/9 + 4*H*T/9 + H/3 + 4*T**2/9 + 2*T/3 + + t, x = symbols('t, x', positive=True, integer=True) + assert isinstance(B[t], RandomIndexedSymbol) + + raises(ValueError, lambda: BernoulliProcess("X", p=1.1, success=1, failure=0)) + raises(NotImplementedError, lambda: B(t)) + + raises(IndexError, lambda: B[-3]) + assert B.joint_distribution(B[3], B[9]) == JointDistributionHandmade(Lambda((B[3], B[9]), + Piecewise((0.6, Eq(B[3], 1)), (0.4, Eq(B[3], 0)), (0, True)) + *Piecewise((0.6, Eq(B[9], 1)), (0.4, Eq(B[9], 0)), (0, True)))) + + assert B.joint_distribution(2, B[4]) == JointDistributionHandmade(Lambda((B[2], B[4]), + Piecewise((0.6, Eq(B[2], 1)), (0.4, Eq(B[2], 0)), (0, True)) + *Piecewise((0.6, Eq(B[4], 1)), (0.4, Eq(B[4], 0)), (0, True)))) + + # Test for the sum distribution of Bernoulli Process RVs + Y = B[1] + B[2] + B[3] + assert P(Eq(Y, 0)).round(2) == Float(0.06, 1) + assert P(Eq(Y, 2)).round(2) == Float(0.43, 2) + assert P(Eq(Y, 4)).round(2) == 0 + assert P(Gt(Y, 1)).round(2) == Float(0.65, 2) + # Test for independency of each Random Indexed variable + assert P(Eq(B[1], 0) & Eq(B[2], 1) & Eq(B[3], 0) & Eq(B[4], 1)).round(2) == Float(0.06, 1) + + assert E(2 * B[1] + B[2]).round(2) == Float(1.80, 3) + assert E(2 * B[1] + B[2] + 5).round(2) == Float(6.80, 3) + assert E(B[2] * B[4] + B[10]).round(2) == Float(0.96, 2) + assert E(B[2] > 0, Eq(B[1],1) & Eq(B[2],1)).round(2) == Float(0.60,2) + assert E(B[1]) == 0.6 + assert P(B[1] > 0).round(2) == Float(0.60, 2) + assert P(B[1] < 1).round(2) == Float(0.40, 2) + assert P(B[1] > 0, B[2] <= 1).round(2) == Float(0.60, 2) + assert P(B[12] * B[5] > 0).round(2) == Float(0.36, 2) + assert P(B[12] * B[5] > 0, B[4] < 1).round(2) == Float(0.36, 2) + assert P(Eq(B[2], 1), B[2] > 0) == 1.0 + assert P(Eq(B[5], 3)) == 0 + assert P(Eq(B[1], 1), B[1] < 0) == 0 + assert P(B[2] > 0, Eq(B[2], 1)) == 1 + assert P(B[2] < 0, Eq(B[2], 1)) == 0 + assert P(B[2] > 0, B[2]==7) == 0 + assert P(B[5] > 0, B[5]) == BernoulliDistribution(0.6, 0, 1) + raises(ValueError, lambda: P(3)) + raises(ValueError, lambda: P(B[3] > 0, 3)) + + # test issue 19456 + expr = Sum(B[t], (t, 0, 4)) + expr2 = Sum(B[t], (t, 1, 3)) + expr3 = Sum(B[t]**2, (t, 1, 3)) + assert expr.doit() == B[0] + B[1] + B[2] + B[3] + B[4] + assert expr2.doit() == Y + assert expr3.doit() == B[1]**2 + B[2]**2 + B[3]**2 + assert B[2*t].free_symbols == {B[2*t], t} + assert B[4].free_symbols == {B[4]} + assert B[x*t].free_symbols == {B[x*t], x, t} + + #test issue 20078 + assert (2*B[t] + 3*B[t]).simplify() == 5*B[t] + assert (2*B[t] - 3*B[t]).simplify() == -B[t] + assert (2*(0.25*B[t])).simplify() == 0.5*B[t] + assert (2*B[t] * 0.25*B[t]).simplify() == 0.5*B[t]**2 + assert (B[t]**2 + B[t]**3).simplify() == (B[t] + 1)*B[t]**2 + +def test_PoissonProcess(): + X = PoissonProcess("X", 3) + assert X.state_space == S.Naturals0 + assert X.index_set == Interval(0, oo) + assert X.lamda == 3 + + t, d, x, y = symbols('t d x y', positive=True) + assert isinstance(X(t), RandomIndexedSymbol) + assert X.distribution(t) == PoissonDistribution(3*t) + with warns_deprecated_sympy(): + X.distribution(X(t)) + raises(ValueError, lambda: PoissonProcess("X", -1)) + raises(NotImplementedError, lambda: X[t]) + raises(IndexError, lambda: X(-5)) + + assert X.joint_distribution(X(2), X(3)) == JointDistributionHandmade(Lambda((X(2), X(3)), + 6**X(2)*9**X(3)*exp(-15)/(factorial(X(2))*factorial(X(3))))) + + assert X.joint_distribution(4, 6) == JointDistributionHandmade(Lambda((X(4), X(6)), + 12**X(4)*18**X(6)*exp(-30)/(factorial(X(4))*factorial(X(6))))) + + assert P(X(t) < 1) == exp(-3*t) + assert P(Eq(X(t), 0), Contains(t, Interval.Lopen(3, 5))) == exp(-6) # exp(-2*lamda) + res = P(Eq(X(t), 1), Contains(t, Interval.Lopen(3, 4))) + assert res == 3*exp(-3) + + # Equivalent to P(Eq(X(t), 1))**4 because of non-overlapping intervals + assert P(Eq(X(t), 1) & Eq(X(d), 1) & Eq(X(x), 1) & Eq(X(y), 1), Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Lopen(1, 2)) & Contains(x, Interval.Lopen(2, 3)) + & Contains(y, Interval.Lopen(3, 4))) == res**4 + + # Return Probability because of overlapping intervals + assert P(Eq(X(t), 2) & Eq(X(d), 3), Contains(t, Interval.Lopen(0, 2)) + & Contains(d, Interval.Ropen(2, 4))) == \ + Probability(Eq(X(d), 3) & Eq(X(t), 2), Contains(t, Interval.Lopen(0, 2)) + & Contains(d, Interval.Ropen(2, 4))) + + raises(ValueError, lambda: P(Eq(X(t), 2) & Eq(X(d), 3), + Contains(t, Interval.Lopen(0, 4)) & Contains(d, Interval.Lopen(3, oo)))) # no bound on d + assert P(Eq(X(3), 2)) == 81*exp(-9)/2 + assert P(Eq(X(t), 2), Contains(t, Interval.Lopen(0, 5))) == 225*exp(-15)/2 + + # Check that probability works correctly by adding it to 1 + res1 = P(X(t) <= 3, Contains(t, Interval.Lopen(0, 5))) + res2 = P(X(t) > 3, Contains(t, Interval.Lopen(0, 5))) + assert res1 == 691*exp(-15) + assert (res1 + res2).simplify() == 1 + + # Check Not and Or + assert P(Not(Eq(X(t), 2) & (X(d) > 3)), Contains(t, Interval.Ropen(2, 4)) & \ + Contains(d, Interval.Lopen(7, 8))).simplify() == -18*exp(-6) + 234*exp(-9) + 1 + assert P(Eq(X(t), 2) | Ne(X(t), 4), Contains(t, Interval.Ropen(2, 4))) == 1 - 36*exp(-6) + raises(ValueError, lambda: P(X(t) > 2, X(t) + X(d))) + assert E(X(t)) == 3*t # property of the distribution at a given timestamp + assert E(X(t)**2 + X(d)*2 + X(y)**3, Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Lopen(1, 2)) & Contains(y, Interval.Ropen(3, 4))) == 75 + assert E(X(t)**2, Contains(t, Interval.Lopen(0, 1))) == 12 + assert E(x*(X(t) + X(d))*(X(t)**2+X(d)**2), Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Ropen(1, 2))) == \ + Expectation(x*(X(d) + X(t))*(X(d)**2 + X(t)**2), Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Ropen(1, 2))) + + # Value Error because of infinite time bound + raises(ValueError, lambda: E(X(t)**3, Contains(t, Interval.Lopen(1, oo)))) + + # Equivalent to E(X(t)**2) - E(X(d)**2) == E(X(1)**2) - E(X(1)**2) == 0 + assert E((X(t) + X(d))*(X(t) - X(d)), Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Lopen(1, 2))) == 0 + assert E(X(2) + x*E(X(5))) == 15*x + 6 + assert E(x*X(1) + y) == 3*x + y + assert P(Eq(X(1), 2) & Eq(X(t), 3), Contains(t, Interval.Lopen(1, 2))) == 81*exp(-6)/4 + Y = PoissonProcess("Y", 6) + Z = X + Y + assert Z.lamda == X.lamda + Y.lamda == 9 + raises(ValueError, lambda: X + 5) # should be added be only PoissonProcess instance + N, M = Z.split(4, 5) + assert N.lamda == 4 + assert M.lamda == 5 + raises(ValueError, lambda: Z.split(3, 2)) # 2+3 != 9 + + raises(ValueError, lambda :P(Eq(X(t), 0), Contains(t, Interval.Lopen(1, 3)) & Eq(X(1), 0))) + # check if it handles queries with two random variables in one args + res1 = P(Eq(N(3), N(5))) + assert res1 == P(Eq(N(t), 0), Contains(t, Interval(3, 5))) + res2 = P(N(3) > N(1)) + assert res2 == P((N(t) > 0), Contains(t, Interval(1, 3))) + assert P(N(3) < N(1)) == 0 # condition is not possible + res3 = P(N(3) <= N(1)) # holds only for Eq(N(3), N(1)) + assert res3 == P(Eq(N(t), 0), Contains(t, Interval(1, 3))) + + # tests from https://www.probabilitycourse.com/chapter11/11_1_2_basic_concepts_of_the_poisson_process.php + X = PoissonProcess('X', 10) # 11.1 + assert P(Eq(X(S(1)/3), 3) & Eq(X(1), 10)) == exp(-10)*Rational(8000000000, 11160261) + assert P(Eq(X(1), 1), Eq(X(S(1)/3), 3)) == 0 + assert P(Eq(X(1), 10), Eq(X(S(1)/3), 3)) == P(Eq(X(S(2)/3), 7)) + + X = PoissonProcess('X', 2) # 11.2 + assert P(X(S(1)/2) < 1) == exp(-1) + assert P(X(3) < 1, Eq(X(1), 0)) == exp(-4) + assert P(Eq(X(4), 3), Eq(X(2), 3)) == exp(-4) + + X = PoissonProcess('X', 3) + assert P(Eq(X(2), 5) & Eq(X(1), 2)) == Rational(81, 4)*exp(-6) + + # check few properties + assert P(X(2) <= 3, X(1)>=1) == 3*P(Eq(X(1), 0)) + 2*P(Eq(X(1), 1)) + P(Eq(X(1), 2)) + assert P(X(2) <= 3, X(1) > 1) == 2*P(Eq(X(1), 0)) + 1*P(Eq(X(1), 1)) + assert P(Eq(X(2), 5) & Eq(X(1), 2)) == P(Eq(X(1), 3))*P(Eq(X(1), 2)) + assert P(Eq(X(3), 4), Eq(X(1), 3)) == P(Eq(X(2), 1)) + + #test issue 20078 + assert (2*X(t) + 3*X(t)).simplify() == 5*X(t) + assert (2*X(t) - 3*X(t)).simplify() == -X(t) + assert (2*(0.25*X(t))).simplify() == 0.5*X(t) + assert (2*X(t) * 0.25*X(t)).simplify() == 0.5*X(t)**2 + assert (X(t)**2 + X(t)**3).simplify() == (X(t) + 1)*X(t)**2 + +def test_WienerProcess(): + X = WienerProcess("X") + assert X.state_space == S.Reals + assert X.index_set == Interval(0, oo) + + t, d, x, y = symbols('t d x y', positive=True) + assert isinstance(X(t), RandomIndexedSymbol) + assert X.distribution(t) == NormalDistribution(0, sqrt(t)) + with warns_deprecated_sympy(): + X.distribution(X(t)) + raises(ValueError, lambda: PoissonProcess("X", -1)) + raises(NotImplementedError, lambda: X[t]) + raises(IndexError, lambda: X(-2)) + + assert X.joint_distribution(X(2), X(3)) == JointDistributionHandmade( + Lambda((X(2), X(3)), sqrt(6)*exp(-X(2)**2/4)*exp(-X(3)**2/6)/(12*pi))) + assert X.joint_distribution(4, 6) == JointDistributionHandmade( + Lambda((X(4), X(6)), sqrt(6)*exp(-X(4)**2/8)*exp(-X(6)**2/12)/(24*pi))) + + assert P(X(t) < 3).simplify() == erf(3*sqrt(2)/(2*sqrt(t)))/2 + S(1)/2 + assert P(X(t) > 2, Contains(t, Interval.Lopen(3, 7))).simplify() == S(1)/2 -\ + erf(sqrt(2)/2)/2 + + # Equivalent to P(X(1)>1)**4 + assert P((X(t) > 4) & (X(d) > 3) & (X(x) > 2) & (X(y) > 1), + Contains(t, Interval.Lopen(0, 1)) & Contains(d, Interval.Lopen(1, 2)) + & Contains(x, Interval.Lopen(2, 3)) & Contains(y, Interval.Lopen(3, 4))).simplify() ==\ + (1 - erf(sqrt(2)/2))*(1 - erf(sqrt(2)))*(1 - erf(3*sqrt(2)/2))*(1 - erf(2*sqrt(2)))/16 + + # Contains an overlapping interval so, return Probability + assert P((X(t)< 2) & (X(d)> 3), Contains(t, Interval.Lopen(0, 2)) + & Contains(d, Interval.Ropen(2, 4))) == Probability((X(d) > 3) & (X(t) < 2), + Contains(d, Interval.Ropen(2, 4)) & Contains(t, Interval.Lopen(0, 2))) + + assert str(P(Not((X(t) < 5) & (X(d) > 3)), Contains(t, Interval.Ropen(2, 4)) & + Contains(d, Interval.Lopen(7, 8))).simplify()) == \ + '-(1 - erf(3*sqrt(2)/2))*(2 - erfc(5/2))/4 + 1' + # Distribution has mean 0 at each timestamp + assert E(X(t)) == 0 + assert E(x*(X(t) + X(d))*(X(t)**2+X(d)**2), Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Ropen(1, 2))) == Expectation(x*(X(d) + X(t))*(X(d)**2 + X(t)**2), + Contains(d, Interval.Ropen(1, 2)) & Contains(t, Interval.Lopen(0, 1))) + assert E(X(t) + x*E(X(3))) == 0 + + #test issue 20078 + assert (2*X(t) + 3*X(t)).simplify() == 5*X(t) + assert (2*X(t) - 3*X(t)).simplify() == -X(t) + assert (2*(0.25*X(t))).simplify() == 0.5*X(t) + assert (2*X(t) * 0.25*X(t)).simplify() == 0.5*X(t)**2 + assert (X(t)**2 + X(t)**3).simplify() == (X(t) + 1)*X(t)**2 + + +def test_GammaProcess_symbolic(): + t, d, x, y, g, l = symbols('t d x y g l', positive=True) + X = GammaProcess("X", l, g) + + raises(NotImplementedError, lambda: X[t]) + raises(IndexError, lambda: X(-1)) + assert isinstance(X(t), RandomIndexedSymbol) + assert X.state_space == Interval(0, oo) + assert X.distribution(t) == GammaDistribution(g*t, 1/l) + with warns_deprecated_sympy(): + X.distribution(X(t)) + assert X.joint_distribution(5, X(3)) == JointDistributionHandmade(Lambda( + (X(5), X(3)), l**(8*g)*exp(-l*X(3))*exp(-l*X(5))*X(3)**(3*g - 1)*X(5)**(5*g + - 1)/(gamma(3*g)*gamma(5*g)))) + # property of the gamma process at any given timestamp + assert E(X(t)) == g*t/l + assert variance(X(t)).simplify() == g*t/l**2 + + # Equivalent to E(2*X(1)) + E(X(1)**2) + E(X(1)**3), where E(X(1)) == g/l + assert E(X(t)**2 + X(d)*2 + X(y)**3, Contains(t, Interval.Lopen(0, 1)) + & Contains(d, Interval.Lopen(1, 2)) & Contains(y, Interval.Ropen(3, 4))) == \ + 2*g/l + (g**2 + g)/l**2 + (g**3 + 3*g**2 + 2*g)/l**3 + + assert P(X(t) > 3, Contains(t, Interval.Lopen(3, 4))).simplify() == \ + 1 - lowergamma(g, 3*l)/gamma(g) # equivalent to P(X(1)>3) + + + #test issue 20078 + assert (2*X(t) + 3*X(t)).simplify() == 5*X(t) + assert (2*X(t) - 3*X(t)).simplify() == -X(t) + assert (2*(0.25*X(t))).simplify() == 0.5*X(t) + assert (2*X(t) * 0.25*X(t)).simplify() == 0.5*X(t)**2 + assert (X(t)**2 + X(t)**3).simplify() == (X(t) + 1)*X(t)**2 +def test_GammaProcess_numeric(): + t, d, x, y = symbols('t d x y', positive=True) + X = GammaProcess("X", 1, 2) + assert X.state_space == Interval(0, oo) + assert X.index_set == Interval(0, oo) + assert X.lamda == 1 + assert X.gamma == 2 + + raises(ValueError, lambda: GammaProcess("X", -1, 2)) + raises(ValueError, lambda: GammaProcess("X", 0, -2)) + raises(ValueError, lambda: GammaProcess("X", -1, -2)) + + # all are independent because of non-overlapping intervals + assert P((X(t) > 4) & (X(d) > 3) & (X(x) > 2) & (X(y) > 1), Contains(t, + Interval.Lopen(0, 1)) & Contains(d, Interval.Lopen(1, 2)) & Contains(x, + Interval.Lopen(2, 3)) & Contains(y, Interval.Lopen(3, 4))).simplify() == \ + 120*exp(-10) + + # Check working with Not and Or + assert P(Not((X(t) < 5) & (X(d) > 3)), Contains(t, Interval.Ropen(2, 4)) & + Contains(d, Interval.Lopen(7, 8))).simplify() == -4*exp(-3) + 472*exp(-8)/3 + 1 + assert P((X(t) > 2) | (X(t) < 4), Contains(t, Interval.Ropen(1, 4))).simplify() == \ + -643*exp(-4)/15 + 109*exp(-2)/15 + 1 + + assert E(X(t)) == 2*t # E(X(t)) == gamma*t/l + assert E(X(2) + x*E(X(5))) == 10*x + 4 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_symbolic_multivariate.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_symbolic_multivariate.py new file mode 100644 index 0000000000000000000000000000000000000000..79979e20a6f10d2a2ddfe85ce4c8df145e98c3fd --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_symbolic_multivariate.py @@ -0,0 +1,172 @@ +from sympy.stats import Expectation, Normal, Variance, Covariance +from sympy.testing.pytest import raises +from sympy.core.symbol import symbols +from sympy.matrices.exceptions import ShapeError +from sympy.matrices.dense import Matrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.special import ZeroMatrix +from sympy.stats.rv import RandomMatrixSymbol +from sympy.stats.symbolic_multivariate_probability import (ExpectationMatrix, + VarianceMatrix, CrossCovarianceMatrix) + +j, k = symbols("j,k") + +A = MatrixSymbol("A", k, k) +B = MatrixSymbol("B", k, k) +C = MatrixSymbol("C", k, k) +D = MatrixSymbol("D", k, k) + +a = MatrixSymbol("a", k, 1) +b = MatrixSymbol("b", k, 1) + +A2 = MatrixSymbol("A2", 2, 2) +B2 = MatrixSymbol("B2", 2, 2) + +X = RandomMatrixSymbol("X", k, 1) +Y = RandomMatrixSymbol("Y", k, 1) +Z = RandomMatrixSymbol("Z", k, 1) +W = RandomMatrixSymbol("W", k, 1) + +R = RandomMatrixSymbol("R", k, k) + +X2 = RandomMatrixSymbol("X2", 2, 1) + +normal = Normal("normal", 0, 1) + +m1 = Matrix([ + [1, j*Normal("normal2", 2, 1)], + [normal, 0] +]) + +def test_multivariate_expectation(): + expr = Expectation(a) + assert expr == Expectation(a) == ExpectationMatrix(a) + assert expr.expand() == a + + expr = Expectation(X) + assert expr == Expectation(X) == ExpectationMatrix(X) + assert expr.shape == (k, 1) + assert expr.rows == k + assert expr.cols == 1 + assert isinstance(expr, ExpectationMatrix) + + expr = Expectation(A*X + b) + assert expr == ExpectationMatrix(A*X + b) + assert expr.expand() == A*ExpectationMatrix(X) + b + assert isinstance(expr, ExpectationMatrix) + assert expr.shape == (k, 1) + + expr = Expectation(m1*X2) + assert expr.expand() == expr + + expr = Expectation(A2*m1*B2*X2) + assert expr.args[0].args == (A2, m1, B2, X2) + assert expr.expand() == A2*ExpectationMatrix(m1*B2*X2) + + expr = Expectation((X + Y)*(X - Y).T) + assert expr.expand() == ExpectationMatrix(X*X.T) - ExpectationMatrix(X*Y.T) +\ + ExpectationMatrix(Y*X.T) - ExpectationMatrix(Y*Y.T) + + expr = Expectation(A*X + B*Y) + assert expr.expand() == A*ExpectationMatrix(X) + B*ExpectationMatrix(Y) + + assert Expectation(m1).doit() == Matrix([[1, 2*j], [0, 0]]) + + x1 = Matrix([ + [Normal('N11', 11, 1), Normal('N12', 12, 1)], + [Normal('N21', 21, 1), Normal('N22', 22, 1)] + ]) + x2 = Matrix([ + [Normal('M11', 1, 1), Normal('M12', 2, 1)], + [Normal('M21', 3, 1), Normal('M22', 4, 1)] + ]) + + assert Expectation(Expectation(x1 + x2)).doit(deep=False) == ExpectationMatrix(x1 + x2) + assert Expectation(Expectation(x1 + x2)).doit() == Matrix([[12, 14], [24, 26]]) + + +def test_multivariate_variance(): + raises(ShapeError, lambda: Variance(A)) + + expr = Variance(a) + assert expr == Variance(a) == VarianceMatrix(a) + assert expr.expand() == ZeroMatrix(k, k) + expr = Variance(a.T) + assert expr == Variance(a.T) == VarianceMatrix(a.T) + assert expr.expand() == ZeroMatrix(k, k) + + expr = Variance(X) + assert expr == Variance(X) == VarianceMatrix(X) + assert expr.shape == (k, k) + assert expr.rows == k + assert expr.cols == k + assert isinstance(expr, VarianceMatrix) + + expr = Variance(A*X) + assert expr == VarianceMatrix(A*X) + assert expr.expand() == A*VarianceMatrix(X)*A.T + assert isinstance(expr, VarianceMatrix) + assert expr.shape == (k, k) + + expr = Variance(A*B*X) + assert expr.expand() == A*B*VarianceMatrix(X)*B.T*A.T + + expr = Variance(m1*X2) + assert expr.expand() == expr + + expr = Variance(A2*m1*B2*X2) + assert expr.args[0].args == (A2, m1, B2, X2) + assert expr.expand() == expr + + expr = Variance(A*X + B*Y) + assert expr.expand() == 2*A*CrossCovarianceMatrix(X, Y)*B.T +\ + A*VarianceMatrix(X)*A.T + B*VarianceMatrix(Y)*B.T + +def test_multivariate_crosscovariance(): + raises(ShapeError, lambda: Covariance(X, Y.T)) + raises(ShapeError, lambda: Covariance(X, A)) + + + expr = Covariance(a.T, b.T) + assert expr.shape == (1, 1) + assert expr.expand() == ZeroMatrix(1, 1) + + expr = Covariance(a, b) + assert expr == Covariance(a, b) == CrossCovarianceMatrix(a, b) + assert expr.expand() == ZeroMatrix(k, k) + assert expr.shape == (k, k) + assert expr.rows == k + assert expr.cols == k + assert isinstance(expr, CrossCovarianceMatrix) + + expr = Covariance(A*X + a, b) + assert expr.expand() == ZeroMatrix(k, k) + + expr = Covariance(X, Y) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == expr + + expr = Covariance(X, X) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == VarianceMatrix(X) + + expr = Covariance(X + Y, Z) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == CrossCovarianceMatrix(X, Z) + CrossCovarianceMatrix(Y, Z) + + expr = Covariance(A*X, Y) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == A*CrossCovarianceMatrix(X, Y) + + expr = Covariance(X, B*Y) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == CrossCovarianceMatrix(X, Y)*B.T + + expr = Covariance(A*X + a, B.T*Y + b) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == A*CrossCovarianceMatrix(X, Y)*B + + expr = Covariance(A*X + B*Y + a, C.T*Z + D.T*W + b) + assert isinstance(expr, CrossCovarianceMatrix) + assert expr.expand() == A*CrossCovarianceMatrix(X, W)*D + A*CrossCovarianceMatrix(X, Z)*C \ + + B*CrossCovarianceMatrix(Y, W)*D + B*CrossCovarianceMatrix(Y, Z)*C diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_symbolic_probability.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_symbolic_probability.py new file mode 100644 index 0000000000000000000000000000000000000000..edac942ac081c0d44cafd31761b77bc577b6a3fd --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/stats/tests/test_symbolic_probability.py @@ -0,0 +1,175 @@ +from sympy.concrete.summations import Sum +from sympy.core.mul import Mul +from sympy.core.numbers import (oo, pi) +from sympy.core.relational import Eq +from sympy.core.symbol import (Dummy, symbols) +from sympy.functions.elementary.exponential import exp +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import sin +from sympy.integrals.integrals import Integral +from sympy.core.expr import unchanged +from sympy.stats import (Normal, Poisson, variance, Covariance, Variance, + Probability, Expectation, Moment, CentralMoment) +from sympy.stats.rv import probability, expectation + + +def test_literal_probability(): + X = Normal('X', 2, 3) + Y = Normal('Y', 3, 4) + Z = Poisson('Z', 4) + W = Poisson('W', 3) + x = symbols('x', real=True) + y, w, z = symbols('y, w, z') + + assert Probability(X > 0).evaluate_integral() == probability(X > 0) + assert Probability(X > x).evaluate_integral() == probability(X > x) + assert Probability(X > 0).rewrite(Integral).doit() == probability(X > 0) + assert Probability(X > x).rewrite(Integral).doit() == probability(X > x) + + assert Expectation(X).evaluate_integral() == expectation(X) + assert Expectation(X).rewrite(Integral).doit() == expectation(X) + assert Expectation(X**2).evaluate_integral() == expectation(X**2) + assert Expectation(x*X).args == (x*X,) + assert Expectation(x*X).expand() == x*Expectation(X) + assert Expectation(2*X + 3*Y + z*X*Y).expand() == 2*Expectation(X) + 3*Expectation(Y) + z*Expectation(X*Y) + assert Expectation(2*X + 3*Y + z*X*Y).args == (2*X + 3*Y + z*X*Y,) + assert Expectation(sin(X)) == Expectation(sin(X)).expand() + assert Expectation(2*x*sin(X)*Y + y*X**2 + z*X*Y).expand() == 2*x*Expectation(sin(X)*Y) \ + + y*Expectation(X**2) + z*Expectation(X*Y) + assert Expectation(X + Y).expand() == Expectation(X) + Expectation(Y) + assert Expectation((X + Y)*(X - Y)).expand() == Expectation(X**2) - Expectation(Y**2) + assert Expectation((X + Y)*(X - Y)).expand().doit() == -12 + assert Expectation(X + Y, evaluate=True).doit() == 5 + assert Expectation(X + Expectation(Y)).doit() == 5 + assert Expectation(X + Expectation(Y)).doit(deep=False) == 2 + Expectation(Expectation(Y)) + assert Expectation(X + Expectation(Y + Expectation(2*X))).doit(deep=False) == 2 \ + + Expectation(Expectation(Y + Expectation(2*X))) + assert Expectation(X + Expectation(Y + Expectation(2*X))).doit() == 9 + assert Expectation(Expectation(2*X)).doit() == 4 + assert Expectation(Expectation(2*X)).doit(deep=False) == Expectation(2*X) + assert Expectation(4*Expectation(2*X)).doit(deep=False) == 4*Expectation(2*X) + assert Expectation((X + Y)**3).expand() == 3*Expectation(X*Y**2) +\ + 3*Expectation(X**2*Y) + Expectation(X**3) + Expectation(Y**3) + assert Expectation((X - Y)**3).expand() == 3*Expectation(X*Y**2) -\ + 3*Expectation(X**2*Y) + Expectation(X**3) - Expectation(Y**3) + assert Expectation((X - Y)**2).expand() == -2*Expectation(X*Y) +\ + Expectation(X**2) + Expectation(Y**2) + + assert Variance(w).args == (w,) + assert Variance(w).expand() == 0 + assert Variance(X).evaluate_integral() == Variance(X).rewrite(Integral).doit() == variance(X) + assert Variance(X + z).args == (X + z,) + assert Variance(X + z).expand() == Variance(X) + assert Variance(X*Y).args == (Mul(X, Y),) + assert type(Variance(X*Y)) == Variance + assert Variance(z*X).expand() == z**2*Variance(X) + assert Variance(X + Y).expand() == Variance(X) + Variance(Y) + 2*Covariance(X, Y) + assert Variance(X + Y + Z + W).expand() == (Variance(X) + Variance(Y) + Variance(Z) + Variance(W) + + 2 * Covariance(X, Y) + 2 * Covariance(X, Z) + 2 * Covariance(X, W) + + 2 * Covariance(Y, Z) + 2 * Covariance(Y, W) + 2 * Covariance(W, Z)) + assert Variance(X**2).evaluate_integral() == variance(X**2) + assert unchanged(Variance, X**2) + assert Variance(x*X**2).expand() == x**2*Variance(X**2) + assert Variance(sin(X)).args == (sin(X),) + assert Variance(sin(X)).expand() == Variance(sin(X)) + assert Variance(x*sin(X)).expand() == x**2*Variance(sin(X)) + + assert Covariance(w, z).args == (w, z) + assert Covariance(w, z).expand() == 0 + assert Covariance(X, w).expand() == 0 + assert Covariance(w, X).expand() == 0 + assert Covariance(X, Y).args == (X, Y) + assert type(Covariance(X, Y)) == Covariance + assert Covariance(z*X + 3, Y).expand() == z*Covariance(X, Y) + assert Covariance(X, X).args == (X, X) + assert Covariance(X, X).expand() == Variance(X) + assert Covariance(z*X + 3, w*Y + 4).expand() == w*z*Covariance(X,Y) + assert Covariance(X, Y) == Covariance(Y, X) + assert Covariance(X + Y, Z + W).expand() == Covariance(W, X) + Covariance(W, Y) + Covariance(X, Z) + Covariance(Y, Z) + assert Covariance(x*X + y*Y, z*Z + w*W).expand() == (x*w*Covariance(W, X) + w*y*Covariance(W, Y) + + x*z*Covariance(X, Z) + y*z*Covariance(Y, Z)) + assert Covariance(x*X**2 + y*sin(Y), z*Y*Z**2 + w*W).expand() == (w*x*Covariance(W, X**2) + w*y*Covariance(sin(Y), W) + + x*z*Covariance(Y*Z**2, X**2) + y*z*Covariance(Y*Z**2, sin(Y))) + assert Covariance(X, X**2).expand() == Covariance(X, X**2) + assert Covariance(X, sin(X)).expand() == Covariance(sin(X), X) + assert Covariance(X**2, sin(X)*Y).expand() == Covariance(sin(X)*Y, X**2) + assert Covariance(w, X).evaluate_integral() == 0 + + +def test_probability_rewrite(): + X = Normal('X', 2, 3) + Y = Normal('Y', 3, 4) + Z = Poisson('Z', 4) + W = Poisson('W', 3) + x, y, w, z = symbols('x, y, w, z') + + assert Variance(w).rewrite(Expectation) == 0 + assert Variance(X).rewrite(Expectation) == Expectation(X ** 2) - Expectation(X) ** 2 + assert Variance(X, condition=Y).rewrite(Expectation) == Expectation(X ** 2, Y) - Expectation(X, Y) ** 2 + assert Variance(X, Y) != Expectation(X**2) - Expectation(X)**2 + assert Variance(X + z).rewrite(Expectation) == Expectation((X + z) ** 2) - Expectation(X + z) ** 2 + assert Variance(X * Y).rewrite(Expectation) == Expectation(X ** 2 * Y ** 2) - Expectation(X * Y) ** 2 + + assert Covariance(w, X).rewrite(Expectation) == -w*Expectation(X) + Expectation(w*X) + assert Covariance(X, Y).rewrite(Expectation) == Expectation(X*Y) - Expectation(X)*Expectation(Y) + assert Covariance(X, Y, condition=W).rewrite(Expectation) == Expectation(X * Y, W) - Expectation(X, W) * Expectation(Y, W) + + w, x, z = symbols("W, x, z") + px = Probability(Eq(X, x)) + pz = Probability(Eq(Z, z)) + + assert Expectation(X).rewrite(Probability) == Integral(x*px, (x, -oo, oo)) + assert Expectation(Z).rewrite(Probability) == Sum(z*pz, (z, 0, oo)) + assert Variance(X).rewrite(Probability) == Integral(x**2*px, (x, -oo, oo)) - Integral(x*px, (x, -oo, oo))**2 + assert Variance(Z).rewrite(Probability) == Sum(z**2*pz, (z, 0, oo)) - Sum(z*pz, (z, 0, oo))**2 + assert Covariance(w, X).rewrite(Probability) == \ + -w*Integral(x*Probability(Eq(X, x)), (x, -oo, oo)) + Integral(w*x*Probability(Eq(X, x)), (x, -oo, oo)) + + # To test rewrite as sum function + assert Variance(X).rewrite(Sum) == Variance(X).rewrite(Integral) + assert Expectation(X).rewrite(Sum) == Expectation(X).rewrite(Integral) + + assert Covariance(w, X).rewrite(Sum) == 0 + + assert Covariance(w, X).rewrite(Integral) == 0 + + assert Variance(X, condition=Y).rewrite(Probability) == Integral(x**2*Probability(Eq(X, x), Y), (x, -oo, oo)) - \ + Integral(x*Probability(Eq(X, x), Y), (x, -oo, oo))**2 + + +def test_symbolic_Moment(): + mu = symbols('mu', real=True) + sigma = symbols('sigma', positive=True) + x = symbols('x') + X = Normal('X', mu, sigma) + M = Moment(X, 4, 2) + assert M.rewrite(Expectation) == Expectation((X - 2)**4) + assert M.rewrite(Probability) == Integral((x - 2)**4*Probability(Eq(X, x)), + (x, -oo, oo)) + k = Dummy('k') + expri = Integral(sqrt(2)*(k - 2)**4*exp(-(k - \ + mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (k, -oo, oo)) + assert M.rewrite(Integral).dummy_eq(expri) + assert M.doit() == (mu**4 - 8*mu**3 + 6*mu**2*sigma**2 + \ + 24*mu**2 - 24*mu*sigma**2 - 32*mu + 3*sigma**4 + 24*sigma**2 + 16) + M = Moment(2, 5) + assert M.doit() == 2**5 + + +def test_symbolic_CentralMoment(): + mu = symbols('mu', real=True) + sigma = symbols('sigma', positive=True) + x = symbols('x') + X = Normal('X', mu, sigma) + CM = CentralMoment(X, 6) + assert CM.rewrite(Expectation) == Expectation((X - Expectation(X))**6) + assert CM.rewrite(Probability) == Integral((x - Integral(x*Probability(True), + (x, -oo, oo)))**6*Probability(Eq(X, x)), (x, -oo, oo)) + k = Dummy('k') + expri = Integral(sqrt(2)*(k - Integral(sqrt(2)*k*exp(-(k - \ + mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (k, -oo, oo)))**6*exp(-(k - \ + mu)**2/(2*sigma**2))/(2*sqrt(pi)*sigma), (k, -oo, oo)) + assert CM.rewrite(Integral).dummy_eq(expri) + assert CM.doit().simplify() == 15*sigma**6 + CM = Moment(5, 5) + assert CM.doit() == 5**5 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..bb4c5aa8afe6fd818e136ec0797b7429e2da76cf --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/__init__.py @@ -0,0 +1,50 @@ +""" Rewrite Rules + +DISCLAIMER: This module is experimental. The interface is subject to change. + +A rule is a function that transforms one expression into another + + Rule :: Expr -> Expr + +A strategy is a function that says how a rule should be applied to a syntax +tree. In general strategies take rules and produce a new rule + + Strategy :: [Rules], Other-stuff -> Rule + +This allows developers to separate a mathematical transformation from the +algorithmic details of applying that transformation. The goal is to separate +the work of mathematical programming from algorithmic programming. + +Submodules + +strategies.rl - some fundamental rules +strategies.core - generic non-SymPy specific strategies +strategies.traverse - strategies that traverse a SymPy tree +strategies.tools - some conglomerate strategies that do depend on SymPy +""" + +from . import rl +from . import traverse +from .rl import rm_id, unpack, flatten, sort, glom, distribute, rebuild +from .util import new +from .core import ( + condition, debug, chain, null_safe, do_one, exhaust, minimize, tryit) +from .tools import canon, typed +from . import branch + +__all__ = [ + 'rl', + + 'traverse', + + 'rm_id', 'unpack', 'flatten', 'sort', 'glom', 'distribute', 'rebuild', + + 'new', + + 'condition', 'debug', 'chain', 'null_safe', 'do_one', 'exhaust', + 'minimize', 'tryit', + + 'canon', 'typed', + + 'branch', +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..fec5afe84a58f3d887a8c762692a3673a2b6d4c8 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/__init__.py @@ -0,0 +1,14 @@ +from . import traverse +from .core import ( + condition, debug, multiplex, exhaust, notempty, + chain, onaction, sfilter, yieldify, do_one, identity) +from .tools import canon + +__all__ = [ + 'traverse', + + 'condition', 'debug', 'multiplex', 'exhaust', 'notempty', 'chain', + 'onaction', 'sfilter', 'yieldify', 'do_one', 'identity', + + 'canon', +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/core.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/core.py new file mode 100644 index 0000000000000000000000000000000000000000..2dabaef69b60d994799f71414699223f84e1809b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/core.py @@ -0,0 +1,116 @@ +""" Generic SymPy-Independent Strategies """ + + +def identity(x): + yield x + + +def exhaust(brule): + """ Apply a branching rule repeatedly until it has no effect """ + def exhaust_brl(expr): + seen = {expr} + for nexpr in brule(expr): + if nexpr not in seen: + seen.add(nexpr) + yield from exhaust_brl(nexpr) + if seen == {expr}: + yield expr + return exhaust_brl + + +def onaction(brule, fn): + def onaction_brl(expr): + for result in brule(expr): + if result != expr: + fn(brule, expr, result) + yield result + return onaction_brl + + +def debug(brule, file=None): + """ Print the input and output expressions at each rule application """ + if not file: + from sys import stdout + file = stdout + + def write(brl, expr, result): + file.write("Rule: %s\n" % brl.__name__) + file.write("In: %s\nOut: %s\n\n" % (expr, result)) + + return onaction(brule, write) + + +def multiplex(*brules): + """ Multiplex many branching rules into one """ + def multiplex_brl(expr): + seen = set() + for brl in brules: + for nexpr in brl(expr): + if nexpr not in seen: + seen.add(nexpr) + yield nexpr + return multiplex_brl + + +def condition(cond, brule): + """ Only apply branching rule if condition is true """ + def conditioned_brl(expr): + if cond(expr): + yield from brule(expr) + else: + pass + return conditioned_brl + + +def sfilter(pred, brule): + """ Yield only those results which satisfy the predicate """ + def filtered_brl(expr): + yield from filter(pred, brule(expr)) + return filtered_brl + + +def notempty(brule): + def notempty_brl(expr): + yielded = False + for nexpr in brule(expr): + yielded = True + yield nexpr + if not yielded: + yield expr + return notempty_brl + + +def do_one(*brules): + """ Execute one of the branching rules """ + def do_one_brl(expr): + yielded = False + for brl in brules: + for nexpr in brl(expr): + yielded = True + yield nexpr + if yielded: + return + return do_one_brl + + +def chain(*brules): + """ + Compose a sequence of brules so that they apply to the expr sequentially + """ + def chain_brl(expr): + if not brules: + yield expr + return + + head, tail = brules[0], brules[1:] + for nexpr in head(expr): + yield from chain(*tail)(nexpr) + + return chain_brl + + +def yieldify(rl): + """ Turn a rule into a branching rule """ + def brl(expr): + yield rl(expr) + return brl diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_core.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_core.py new file mode 100644 index 0000000000000000000000000000000000000000..ac620b0afb6dbadc4d97b29ddbb341cd920b6588 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_core.py @@ -0,0 +1,117 @@ +from sympy.strategies.branch.core import ( + exhaust, debug, multiplex, condition, notempty, chain, onaction, sfilter, + yieldify, do_one, identity) + + +def posdec(x): + if x > 0: + yield x - 1 + else: + yield x + + +def branch5(x): + if 0 < x < 5: + yield x - 1 + elif 5 < x < 10: + yield x + 1 + elif x == 5: + yield x + 1 + yield x - 1 + else: + yield x + + +def even(x): + return x % 2 == 0 + + +def inc(x): + yield x + 1 + + +def one_to_n(n): + yield from range(n) + + +def test_exhaust(): + brl = exhaust(branch5) + assert set(brl(3)) == {0} + assert set(brl(7)) == {10} + assert set(brl(5)) == {0, 10} + + +def test_debug(): + from io import StringIO + file = StringIO() + rl = debug(posdec, file) + list(rl(5)) + log = file.getvalue() + file.close() + + assert posdec.__name__ in log + assert '5' in log + assert '4' in log + + +def test_multiplex(): + brl = multiplex(posdec, branch5) + assert set(brl(3)) == {2} + assert set(brl(7)) == {6, 8} + assert set(brl(5)) == {4, 6} + + +def test_condition(): + brl = condition(even, branch5) + assert set(brl(4)) == set(branch5(4)) + assert set(brl(5)) == set() + + +def test_sfilter(): + brl = sfilter(even, one_to_n) + assert set(brl(10)) == {0, 2, 4, 6, 8} + + +def test_notempty(): + def ident_if_even(x): + if even(x): + yield x + + brl = notempty(ident_if_even) + assert set(brl(4)) == {4} + assert set(brl(5)) == {5} + + +def test_chain(): + assert list(chain()(2)) == [2] # identity + assert list(chain(inc, inc)(2)) == [4] + assert list(chain(branch5, inc)(4)) == [4] + assert set(chain(branch5, inc)(5)) == {5, 7} + assert list(chain(inc, branch5)(5)) == [7] + + +def test_onaction(): + L = [] + + def record(fn, input, output): + L.append((input, output)) + + list(onaction(inc, record)(2)) + assert L == [(2, 3)] + + list(onaction(identity, record)(2)) + assert L == [(2, 3)] + + +def test_yieldify(): + yinc = yieldify(lambda x: x + 1) + assert list(yinc(3)) == [4] + + +def test_do_one(): + def bad(expr): + raise ValueError + + assert list(do_one(inc)(3)) == [4] + assert list(do_one(inc, bad)(3)) == [4] + assert list(do_one(inc, posdec)(3)) == [4] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_tools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_tools.py new file mode 100644 index 0000000000000000000000000000000000000000..c2bd224030c337f0a000d94f6e7e65f3b8bd118f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_tools.py @@ -0,0 +1,42 @@ +from sympy.strategies.branch.tools import canon +from sympy.core.basic import Basic +from sympy.core.numbers import Integer +from sympy.core.singleton import S + + +def posdec(x): + if isinstance(x, Integer) and x > 0: + yield x - 1 + else: + yield x + + +def branch5(x): + if isinstance(x, Integer): + if 0 < x < 5: + yield x - 1 + elif 5 < x < 10: + yield x + 1 + elif x == 5: + yield x + 1 + yield x - 1 + else: + yield x + + +def test_zero_ints(): + expr = Basic(S(2), Basic(S(5), S(3)), S(8)) + expected = {Basic(S(0), Basic(S(0), S(0)), S(0))} + + brl = canon(posdec) + assert set(brl(expr)) == expected + + +def test_split5(): + expr = Basic(S(2), Basic(S(5), S(3)), S(8)) + expected = { + Basic(S(0), Basic(S(0), S(0)), S(10)), + Basic(S(0), Basic(S(10), S(0)), S(10))} + + brl = canon(branch5) + assert set(brl(expr)) == expected diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_traverse.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_traverse.py new file mode 100644 index 0000000000000000000000000000000000000000..e051928210981223004de28b8c617d0438e11ac6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tests/test_traverse.py @@ -0,0 +1,53 @@ +from sympy.core.basic import Basic +from sympy.core.numbers import Integer +from sympy.core.singleton import S +from sympy.strategies.branch.traverse import top_down, sall +from sympy.strategies.branch.core import do_one, identity + + +def inc(x): + if isinstance(x, Integer): + yield x + 1 + + +def test_top_down_easy(): + expr = Basic(S(1), S(2)) + expected = Basic(S(2), S(3)) + brl = top_down(inc) + + assert set(brl(expr)) == {expected} + + +def test_top_down_big_tree(): + expr = Basic(S(1), Basic(S(2)), Basic(S(3), Basic(S(4)), S(5))) + expected = Basic(S(2), Basic(S(3)), Basic(S(4), Basic(S(5)), S(6))) + brl = top_down(inc) + + assert set(brl(expr)) == {expected} + + +def test_top_down_harder_function(): + def split5(x): + if x == 5: + yield x - 1 + yield x + 1 + + expr = Basic(Basic(S(5), S(6)), S(1)) + expected = {Basic(Basic(S(4), S(6)), S(1)), Basic(Basic(S(6), S(6)), S(1))} + brl = top_down(split5) + + assert set(brl(expr)) == expected + + +def test_sall(): + expr = Basic(S(1), S(2)) + expected = Basic(S(2), S(3)) + brl = sall(inc) + + assert list(brl(expr)) == [expected] + + expr = Basic(S(1), S(2), Basic(S(3), S(4))) + expected = Basic(S(2), S(3), Basic(S(3), S(4))) + brl = sall(do_one(inc, identity)) + + assert list(brl(expr)) == [expected] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tools.py new file mode 100644 index 0000000000000000000000000000000000000000..a6c9097323a7962080ae4497ead976818e386518 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/tools.py @@ -0,0 +1,12 @@ +from .core import exhaust, multiplex +from .traverse import top_down + + +def canon(*rules): + """ Strategy for canonicalization + + Apply each branching rule in a top-down fashion through the tree. + Multiplex through all branching rule traversals + Keep doing this until there is no change. + """ + return exhaust(multiplex(*map(top_down, rules))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/traverse.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/traverse.py new file mode 100644 index 0000000000000000000000000000000000000000..28b7098dbda401fc0f0b6d27988d8c37e2f231ae --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/branch/traverse.py @@ -0,0 +1,25 @@ +""" Branching Strategies to Traverse a Tree """ +from itertools import product +from sympy.strategies.util import basic_fns +from .core import chain, identity, do_one + + +def top_down(brule, fns=basic_fns): + """ Apply a rule down a tree running it on the top nodes first """ + return chain(do_one(brule, identity), + lambda expr: sall(top_down(brule, fns), fns)(expr)) + + +def sall(brule, fns=basic_fns): + """ Strategic all - apply rule to args """ + op, new, children, leaf = map(fns.get, ('op', 'new', 'children', 'leaf')) + + def all_rl(expr): + if leaf(expr): + yield expr + else: + myop = op(expr) + argss = product(*map(brule, children(expr))) + for args in argss: + yield new(myop, *args) + return all_rl diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/core.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/core.py new file mode 100644 index 0000000000000000000000000000000000000000..75b75cb5f2e0693eea98a7b1c9b3e7f036ec26f6 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/core.py @@ -0,0 +1,151 @@ +""" Generic SymPy-Independent Strategies """ +from __future__ import annotations +from collections.abc import Callable, Mapping +from typing import TypeVar +from sys import stdout + + +_S = TypeVar('_S') +_T = TypeVar('_T') + + +def identity(x: _T) -> _T: + return x + + +def exhaust(rule: Callable[[_T], _T]) -> Callable[[_T], _T]: + """ Apply a rule repeatedly until it has no effect """ + def exhaustive_rl(expr: _T) -> _T: + new, old = rule(expr), expr + while new != old: + new, old = rule(new), new + return new + return exhaustive_rl + + +def memoize(rule: Callable[[_S], _T]) -> Callable[[_S], _T]: + """Memoized version of a rule + + Notes + ===== + + This cache can grow infinitely, so it is not recommended to use this + than ``functools.lru_cache`` unless you need very heavy computation. + """ + cache: dict[_S, _T] = {} + + def memoized_rl(expr: _S) -> _T: + if expr in cache: + return cache[expr] + else: + result = rule(expr) + cache[expr] = result + return result + return memoized_rl + + +def condition( + cond: Callable[[_T], bool], rule: Callable[[_T], _T] +) -> Callable[[_T], _T]: + """ Only apply rule if condition is true """ + def conditioned_rl(expr: _T) -> _T: + if cond(expr): + return rule(expr) + return expr + return conditioned_rl + + +def chain(*rules: Callable[[_T], _T]) -> Callable[[_T], _T]: + """ + Compose a sequence of rules so that they apply to the expr sequentially + """ + def chain_rl(expr: _T) -> _T: + for rule in rules: + expr = rule(expr) + return expr + return chain_rl + + +def debug(rule, file=None): + """ Print out before and after expressions each time rule is used """ + if file is None: + file = stdout + + def debug_rl(*args, **kwargs): + expr = args[0] + result = rule(*args, **kwargs) + if result != expr: + file.write("Rule: %s\n" % rule.__name__) + file.write("In: %s\nOut: %s\n\n" % (expr, result)) + return result + return debug_rl + + +def null_safe(rule: Callable[[_T], _T | None]) -> Callable[[_T], _T]: + """ Return original expr if rule returns None """ + def null_safe_rl(expr: _T) -> _T: + result = rule(expr) + if result is None: + return expr + return result + return null_safe_rl + + +def tryit(rule: Callable[[_T], _T], exception) -> Callable[[_T], _T]: + """ Return original expr if rule raises exception """ + def try_rl(expr: _T) -> _T: + try: + return rule(expr) + except exception: + return expr + return try_rl + + +def do_one(*rules: Callable[[_T], _T]) -> Callable[[_T], _T]: + """ Try each of the rules until one works. Then stop. """ + def do_one_rl(expr: _T) -> _T: + for rl in rules: + result = rl(expr) + if result != expr: + return result + return expr + return do_one_rl + + +def switch( + key: Callable[[_S], _T], + ruledict: Mapping[_T, Callable[[_S], _S]] +) -> Callable[[_S], _S]: + """ Select a rule based on the result of key called on the function """ + def switch_rl(expr: _S) -> _S: + rl = ruledict.get(key(expr), identity) + return rl(expr) + return switch_rl + + +# XXX Untyped default argument for minimize function +# where python requires SupportsRichComparison type +def _identity(x): + return x + + +def minimize( + *rules: Callable[[_S], _T], + objective=_identity +) -> Callable[[_S], _T]: + """ Select result of rules that minimizes objective + + >>> from sympy.strategies import minimize + >>> inc = lambda x: x + 1 + >>> dec = lambda x: x - 1 + >>> rl = minimize(inc, dec) + >>> rl(4) + 3 + + >>> rl = minimize(inc, dec, objective=lambda x: -x) # maximize + >>> rl(4) + 5 + """ + def minrule(expr: _S) -> _T: + return min([rule(expr) for rule in rules], key=objective) + return minrule diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/rl.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/rl.py new file mode 100644 index 0000000000000000000000000000000000000000..e84ee90582fafcf36fd4205a58b05b650875a9a5 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/rl.py @@ -0,0 +1,176 @@ +""" Generic Rules for SymPy + +This file assumes knowledge of Basic and little else. +""" +from sympy.utilities.iterables import sift +from .util import new + + +# Functions that create rules +def rm_id(isid, new=new): + """ Create a rule to remove identities. + + isid - fn :: x -> Bool --- whether or not this element is an identity. + + Examples + ======== + + >>> from sympy.strategies import rm_id + >>> from sympy import Basic, S + >>> remove_zeros = rm_id(lambda x: x==0) + >>> remove_zeros(Basic(S(1), S(0), S(2))) + Basic(1, 2) + >>> remove_zeros(Basic(S(0), S(0))) # If only identities then we keep one + Basic(0) + + See Also: + unpack + """ + def ident_remove(expr): + """ Remove identities """ + ids = list(map(isid, expr.args)) + if sum(ids) == 0: # No identities. Common case + return expr + elif sum(ids) != len(ids): # there is at least one non-identity + return new(expr.__class__, + *[arg for arg, x in zip(expr.args, ids) if not x]) + else: + return new(expr.__class__, expr.args[0]) + + return ident_remove + + +def glom(key, count, combine): + """ Create a rule to conglomerate identical args. + + Examples + ======== + + >>> from sympy.strategies import glom + >>> from sympy import Add + >>> from sympy.abc import x + + >>> key = lambda x: x.as_coeff_Mul()[1] + >>> count = lambda x: x.as_coeff_Mul()[0] + >>> combine = lambda cnt, arg: cnt * arg + >>> rl = glom(key, count, combine) + + >>> rl(Add(x, -x, 3*x, 2, 3, evaluate=False)) + 3*x + 5 + + Wait, how are key, count and combine supposed to work? + + >>> key(2*x) + x + >>> count(2*x) + 2 + >>> combine(2, x) + 2*x + """ + def conglomerate(expr): + """ Conglomerate together identical args x + x -> 2x """ + groups = sift(expr.args, key) + counts = {k: sum(map(count, args)) for k, args in groups.items()} + newargs = [combine(cnt, mat) for mat, cnt in counts.items()] + if set(newargs) != set(expr.args): + return new(type(expr), *newargs) + else: + return expr + + return conglomerate + + +def sort(key, new=new): + """ Create a rule to sort by a key function. + + Examples + ======== + + >>> from sympy.strategies import sort + >>> from sympy import Basic, S + >>> sort_rl = sort(str) + >>> sort_rl(Basic(S(3), S(1), S(2))) + Basic(1, 2, 3) + """ + + def sort_rl(expr): + return new(expr.__class__, *sorted(expr.args, key=key)) + return sort_rl + + +def distribute(A, B): + """ Turns an A containing Bs into a B of As + + where A, B are container types + + >>> from sympy.strategies import distribute + >>> from sympy import Add, Mul, symbols + >>> x, y = symbols('x,y') + >>> dist = distribute(Mul, Add) + >>> expr = Mul(2, x+y, evaluate=False) + >>> expr + 2*(x + y) + >>> dist(expr) + 2*x + 2*y + """ + + def distribute_rl(expr): + for i, arg in enumerate(expr.args): + if isinstance(arg, B): + first, b, tail = expr.args[:i], expr.args[i], expr.args[i + 1:] + return B(*[A(*(first + (arg,) + tail)) for arg in b.args]) + return expr + return distribute_rl + + +def subs(a, b): + """ Replace expressions exactly """ + def subs_rl(expr): + if expr == a: + return b + else: + return expr + return subs_rl + + +# Functions that are rules +def unpack(expr): + """ Rule to unpack singleton args + + >>> from sympy.strategies import unpack + >>> from sympy import Basic, S + >>> unpack(Basic(S(2))) + 2 + """ + if len(expr.args) == 1: + return expr.args[0] + else: + return expr + + +def flatten(expr, new=new): + """ Flatten T(a, b, T(c, d), T2(e)) to T(a, b, c, d, T2(e)) """ + cls = expr.__class__ + args = [] + for arg in expr.args: + if arg.__class__ == cls: + args.extend(arg.args) + else: + args.append(arg) + return new(expr.__class__, *args) + + +def rebuild(expr): + """ Rebuild a SymPy tree. + + Explanation + =========== + + This function recursively calls constructors in the expression tree. + This forces canonicalization and removes ugliness introduced by the use of + Basic.__new__ + """ + if expr.is_Atom: + return expr + else: + return expr.func(*list(map(rebuild, expr.args))) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_core.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_core.py new file mode 100644 index 0000000000000000000000000000000000000000..1e19bcab1940c476a8996b7ba92e7645a6230034 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_core.py @@ -0,0 +1,118 @@ +from __future__ import annotations +from sympy.core.singleton import S +from sympy.core.basic import Basic +from sympy.strategies.core import ( + null_safe, exhaust, memoize, condition, + chain, tryit, do_one, debug, switch, minimize) +from io import StringIO + + +def posdec(x: int) -> int: + if x > 0: + return x - 1 + return x + + +def inc(x: int) -> int: + return x + 1 + + +def dec(x: int) -> int: + return x - 1 + + +def test_null_safe(): + def rl(expr: int) -> int | None: + if expr == 1: + return 2 + return None + + safe_rl = null_safe(rl) + assert rl(1) == safe_rl(1) + assert rl(3) is None + assert safe_rl(3) == 3 + + +def test_exhaust(): + sink = exhaust(posdec) + assert sink(5) == 0 + assert sink(10) == 0 + + +def test_memoize(): + rl = memoize(posdec) + assert rl(5) == posdec(5) + assert rl(5) == posdec(5) + assert rl(-2) == posdec(-2) + + +def test_condition(): + rl = condition(lambda x: x % 2 == 0, posdec) + assert rl(5) == 5 + assert rl(4) == 3 + + +def test_chain(): + rl = chain(posdec, posdec) + assert rl(5) == 3 + assert rl(1) == 0 + + +def test_tryit(): + def rl(expr: Basic) -> Basic: + assert False + + safe_rl = tryit(rl, AssertionError) + assert safe_rl(S(1)) == S(1) + + +def test_do_one(): + rl = do_one(posdec, posdec) + assert rl(5) == 4 + + def rl1(x: int) -> int: + if x == 1: + return 2 + return x + + def rl2(x: int) -> int: + if x == 2: + return 3 + return x + + rule = do_one(rl1, rl2) + assert rule(1) == 2 + assert rule(rule(1)) == 3 + + +def test_debug(): + file = StringIO() + rl = debug(posdec, file) + rl(5) + log = file.getvalue() + file.close() + + assert posdec.__name__ in log + assert '5' in log + assert '4' in log + + +def test_switch(): + def key(x: int) -> int: + return x % 3 + + rl = switch(key, {0: inc, 1: dec}) + assert rl(3) == 4 + assert rl(4) == 3 + assert rl(5) == 5 + + +def test_minimize(): + def key(x: int) -> int: + return -x + + rl = minimize(inc, dec) + assert rl(4) == 3 + + rl = minimize(inc, dec, objective=key) + assert rl(4) == 5 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_rl.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_rl.py new file mode 100644 index 0000000000000000000000000000000000000000..8bfa90ad4d970b21396e0e1b6427b5a5c68fe381 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_rl.py @@ -0,0 +1,78 @@ +from sympy.core.singleton import S +from sympy.strategies.rl import ( + rm_id, glom, flatten, unpack, sort, distribute, subs, rebuild) +from sympy.core.basic import Basic +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.symbol import symbols +from sympy.abc import x + + +def test_rm_id(): + rmzeros = rm_id(lambda x: x == 0) + assert rmzeros(Basic(S(0), S(1))) == Basic(S(1)) + assert rmzeros(Basic(S(0), S(0))) == Basic(S(0)) + assert rmzeros(Basic(S(2), S(1))) == Basic(S(2), S(1)) + + +def test_glom(): + def key(x): + return x.as_coeff_Mul()[1] + + def count(x): + return x.as_coeff_Mul()[0] + + def newargs(cnt, arg): + return cnt * arg + + rl = glom(key, count, newargs) + + result = rl(Add(x, -x, 3 * x, 2, 3, evaluate=False)) + expected = Add(3 * x, 5) + assert set(result.args) == set(expected.args) + + +def test_flatten(): + assert flatten(Basic(S(1), S(2), Basic(S(3), S(4)))) == \ + Basic(S(1), S(2), S(3), S(4)) + + +def test_unpack(): + assert unpack(Basic(S(2))) == 2 + assert unpack(Basic(S(2), S(3))) == Basic(S(2), S(3)) + + +def test_sort(): + assert sort(str)(Basic(S(3), S(1), S(2))) == Basic(S(1), S(2), S(3)) + + +def test_distribute(): + class T1(Basic): + pass + + class T2(Basic): + pass + + distribute_t12 = distribute(T1, T2) + assert distribute_t12(T1(S(1), S(2), T2(S(3), S(4)), S(5))) == \ + T2(T1(S(1), S(2), S(3), S(5)), T1(S(1), S(2), S(4), S(5))) + assert distribute_t12(T1(S(1), S(2), S(3))) == T1(S(1), S(2), S(3)) + + +def test_distribute_add_mul(): + x, y = symbols('x, y') + expr = Mul(2, Add(x, y), evaluate=False) + expected = Add(Mul(2, x), Mul(2, y)) + distribute_mul = distribute(Mul, Add) + assert distribute_mul(expr) == expected + + +def test_subs(): + rl = subs(1, 2) + assert rl(1) == 2 + assert rl(3) == 3 + + +def test_rebuild(): + expr = Basic.__new__(Add, S(1), S(2)) + assert rebuild(expr) == 3 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_tools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_tools.py new file mode 100644 index 0000000000000000000000000000000000000000..89774aeb92ead5781966e4f48ad32dc63e1bf7e2 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_tools.py @@ -0,0 +1,32 @@ +from sympy.strategies.tools import subs, typed +from sympy.strategies.rl import rm_id +from sympy.core.basic import Basic +from sympy.core.singleton import S + + +def test_subs(): + from sympy.core.symbol import symbols + a, b, c, d, e, f = symbols('a,b,c,d,e,f') + mapping = {a: d, d: a, Basic(e): Basic(f)} + expr = Basic(a, Basic(b, c), Basic(d, Basic(e))) + result = Basic(d, Basic(b, c), Basic(a, Basic(f))) + assert subs(mapping)(expr) == result + + +def test_subs_empty(): + assert subs({})(Basic(S(1), S(2))) == Basic(S(1), S(2)) + + +def test_typed(): + class A(Basic): + pass + + class B(Basic): + pass + + rmzeros = rm_id(lambda x: x == S(0)) + rmones = rm_id(lambda x: x == S(1)) + remove_something = typed({A: rmzeros, B: rmones}) + + assert remove_something(A(S(0), S(1))) == A(S(1)) + assert remove_something(B(S(0), S(1))) == B(S(0)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_traverse.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_traverse.py new file mode 100644 index 0000000000000000000000000000000000000000..ee2409616a8b4f750af8baea149b2ea52c56be9d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_traverse.py @@ -0,0 +1,84 @@ +from sympy.strategies.traverse import ( + top_down, bottom_up, sall, top_down_once, bottom_up_once, basic_fns) +from sympy.strategies.rl import rebuild +from sympy.strategies.util import expr_fns +from sympy.core.add import Add +from sympy.core.basic import Basic +from sympy.core.numbers import Integer +from sympy.core.singleton import S +from sympy.core.symbol import Str, Symbol +from sympy.abc import x, y, z + + +def zero_symbols(expression): + return S.Zero if isinstance(expression, Symbol) else expression + + +def test_sall(): + zero_onelevel = sall(zero_symbols) + + assert zero_onelevel(Basic(x, y, Basic(x, z))) == \ + Basic(S(0), S(0), Basic(x, z)) + + +def test_bottom_up(): + _test_global_traversal(bottom_up) + _test_stop_on_non_basics(bottom_up) + + +def test_top_down(): + _test_global_traversal(top_down) + _test_stop_on_non_basics(top_down) + + +def _test_global_traversal(trav): + zero_all_symbols = trav(zero_symbols) + + assert zero_all_symbols(Basic(x, y, Basic(x, z))) == \ + Basic(S(0), S(0), Basic(S(0), S(0))) + + +def _test_stop_on_non_basics(trav): + def add_one_if_can(expr): + try: + return expr + 1 + except TypeError: + return expr + + expr = Basic(S(1), Str('a'), Basic(S(2), Str('b'))) + expected = Basic(S(2), Str('a'), Basic(S(3), Str('b'))) + rl = trav(add_one_if_can) + + assert rl(expr) == expected + + +class Basic2(Basic): + pass + + +def rl(x): + if x.args and not isinstance(x.args[0], Integer): + return Basic2(*x.args) + return x + + +def test_top_down_once(): + top_rl = top_down_once(rl) + + assert top_rl(Basic(S(1.0), S(2.0), Basic(S(3), S(4)))) == \ + Basic2(S(1.0), S(2.0), Basic(S(3), S(4))) + + +def test_bottom_up_once(): + bottom_rl = bottom_up_once(rl) + + assert bottom_rl(Basic(S(1), S(2), Basic(S(3.0), S(4.0)))) == \ + Basic(S(1), S(2), Basic2(S(3.0), S(4.0))) + + +def test_expr_fns(): + expr = x + y**3 + e = bottom_up(lambda v: v + 1, expr_fns)(expr) + b = bottom_up(lambda v: Basic.__new__(Add, v, S(1)), basic_fns)(expr) + + assert rebuild(b) == e diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_tree.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_tree.py new file mode 100644 index 0000000000000000000000000000000000000000..d5cdde747fe3ab90c8fd181701194403bc526067 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tests/test_tree.py @@ -0,0 +1,92 @@ +from sympy.strategies.tree import treeapply, greedy, allresults, brute +from functools import partial, reduce + + +def inc(x): + return x + 1 + + +def dec(x): + return x - 1 + + +def double(x): + return 2 * x + + +def square(x): + return x**2 + + +def add(*args): + return sum(args) + + +def mul(*args): + return reduce(lambda a, b: a * b, args, 1) + + +def test_treeapply(): + tree = ([3, 3], [4, 1], 2) + assert treeapply(tree, {list: min, tuple: max}) == 3 + assert treeapply(tree, {list: add, tuple: mul}) == 60 + + +def test_treeapply_leaf(): + assert treeapply(3, {}, leaf=lambda x: x**2) == 9 + tree = ([3, 3], [4, 1], 2) + treep1 = ([4, 4], [5, 2], 3) + assert treeapply(tree, {list: min, tuple: max}, leaf=lambda x: x + 1) == \ + treeapply(treep1, {list: min, tuple: max}) + + +def test_treeapply_strategies(): + from sympy.strategies import chain, minimize + join = {list: chain, tuple: minimize} + + assert treeapply(inc, join) == inc + assert treeapply((inc, dec), join)(5) == minimize(inc, dec)(5) + assert treeapply([inc, dec], join)(5) == chain(inc, dec)(5) + tree = (inc, [dec, double]) # either inc or dec-then-double + assert treeapply(tree, join)(5) == 6 + assert treeapply(tree, join)(1) == 0 + + maximize = partial(minimize, objective=lambda x: -x) + join = {list: chain, tuple: maximize} + fn = treeapply(tree, join) + assert fn(4) == 6 # highest value comes from the dec then double + assert fn(1) == 2 # highest value comes from the inc + + +def test_greedy(): + tree = [inc, (dec, double)] # either inc or dec-then-double + + fn = greedy(tree, objective=lambda x: -x) + assert fn(4) == 6 # highest value comes from the dec then double + assert fn(1) == 2 # highest value comes from the inc + + tree = [inc, dec, [inc, dec, [(inc, inc), (dec, dec)]]] + lowest = greedy(tree) + assert lowest(10) == 8 + + highest = greedy(tree, objective=lambda x: -x) + assert highest(10) == 12 + + +def test_allresults(): + # square = lambda x: x**2 + + assert set(allresults(inc)(3)) == {inc(3)} + assert set(allresults([inc, dec])(3)) == {2, 4} + assert set(allresults((inc, dec))(3)) == {3} + assert set(allresults([inc, (dec, double)])(4)) == {5, 6} + + +def test_brute(): + tree = ([inc, dec], square) + fn = brute(tree, lambda x: -x) + + assert fn(2) == (2 + 1)**2 + assert fn(-2) == (-2 - 1)**2 + + assert brute(inc)(1) == 2 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tools.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tools.py new file mode 100644 index 0000000000000000000000000000000000000000..e6a94c16db57206d7c83c8a5e13930c4cffdde47 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tools.py @@ -0,0 +1,53 @@ +from . import rl +from .core import do_one, exhaust, switch +from .traverse import top_down + + +def subs(d, **kwargs): + """ Full simultaneous exact substitution. + + Examples + ======== + + >>> from sympy.strategies.tools import subs + >>> from sympy import Basic, S + >>> mapping = {S(1): S(4), S(4): S(1), Basic(S(5)): Basic(S(6), S(7))} + >>> expr = Basic(S(1), Basic(S(2), S(3)), Basic(S(4), Basic(S(5)))) + >>> subs(mapping)(expr) + Basic(4, Basic(2, 3), Basic(1, Basic(6, 7))) + """ + if d: + return top_down(do_one(*map(rl.subs, *zip(*d.items()))), **kwargs) + else: + return lambda x: x + + +def canon(*rules, **kwargs): + """ Strategy for canonicalization. + + Explanation + =========== + + Apply each rule in a bottom_up fashion through the tree. + Do each one in turn. + Keep doing this until there is no change. + """ + return exhaust(top_down(exhaust(do_one(*rules)), **kwargs)) + + +def typed(ruletypes): + """ Apply rules based on the expression type + + inputs: + ruletypes -- a dict mapping {Type: rule} + + Examples + ======== + + >>> from sympy.strategies import rm_id, typed + >>> from sympy import Add, Mul + >>> rm_zeros = rm_id(lambda x: x==0) + >>> rm_ones = rm_id(lambda x: x==1) + >>> remove_idents = typed({Add: rm_zeros, Mul: rm_ones}) + """ + return switch(type, ruletypes) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/traverse.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/traverse.py new file mode 100644 index 0000000000000000000000000000000000000000..869361f443742b5b7346c9c970f103b955e8473e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/traverse.py @@ -0,0 +1,37 @@ +"""Strategies to Traverse a Tree.""" +from sympy.strategies.util import basic_fns +from sympy.strategies.core import chain, do_one + + +def top_down(rule, fns=basic_fns): + """Apply a rule down a tree running it on the top nodes first.""" + return chain(rule, lambda expr: sall(top_down(rule, fns), fns)(expr)) + + +def bottom_up(rule, fns=basic_fns): + """Apply a rule down a tree running it on the bottom nodes first.""" + return chain(lambda expr: sall(bottom_up(rule, fns), fns)(expr), rule) + + +def top_down_once(rule, fns=basic_fns): + """Apply a rule down a tree - stop on success.""" + return do_one(rule, lambda expr: sall(top_down(rule, fns), fns)(expr)) + + +def bottom_up_once(rule, fns=basic_fns): + """Apply a rule up a tree - stop on success.""" + return do_one(lambda expr: sall(bottom_up(rule, fns), fns)(expr), rule) + + +def sall(rule, fns=basic_fns): + """Strategic all - apply rule to args.""" + op, new, children, leaf = map(fns.get, ('op', 'new', 'children', 'leaf')) + + def all_rl(expr): + if leaf(expr): + return expr + else: + args = map(rule, children(expr)) + return new(op(expr), *args) + + return all_rl diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tree.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tree.py new file mode 100644 index 0000000000000000000000000000000000000000..c2006fde4fc5d09f3d38baae4d7335b4cbd971b7 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/tree.py @@ -0,0 +1,139 @@ +from functools import partial +from sympy.strategies import chain, minimize +from sympy.strategies.core import identity +import sympy.strategies.branch as branch +from sympy.strategies.branch import yieldify + + +def treeapply(tree, join, leaf=identity): + """ Apply functions onto recursive containers (tree). + + Explanation + =========== + + join - a dictionary mapping container types to functions + e.g. ``{list: minimize, tuple: chain}`` + + Keys are containers/iterables. Values are functions [a] -> a. + + Examples + ======== + + >>> from sympy.strategies.tree import treeapply + >>> tree = [(3, 2), (4, 1)] + >>> treeapply(tree, {list: max, tuple: min}) + 2 + + >>> add = lambda *args: sum(args) + >>> def mul(*args): + ... total = 1 + ... for arg in args: + ... total *= arg + ... return total + >>> treeapply(tree, {list: mul, tuple: add}) + 25 + """ + for typ in join: + if isinstance(tree, typ): + return join[typ](*map(partial(treeapply, join=join, leaf=leaf), + tree)) + return leaf(tree) + + +def greedy(tree, objective=identity, **kwargs): + """ Execute a strategic tree. Select alternatives greedily + + Trees + ----- + + Nodes in a tree can be either + + function - a leaf + list - a selection among operations + tuple - a sequence of chained operations + + Textual examples + ---------------- + + Text: Run f, then run g, e.g. ``lambda x: g(f(x))`` + Code: ``(f, g)`` + + Text: Run either f or g, whichever minimizes the objective + Code: ``[f, g]`` + + Textx: Run either f or g, whichever is better, then run h + Code: ``([f, g], h)`` + + Text: Either expand then simplify or try factor then foosimp. Finally print + Code: ``([(expand, simplify), (factor, foosimp)], print)`` + + Objective + --------- + + "Better" is determined by the objective keyword. This function makes + choices to minimize the objective. It defaults to the identity. + + Examples + ======== + + >>> from sympy.strategies.tree import greedy + >>> inc = lambda x: x + 1 + >>> dec = lambda x: x - 1 + >>> double = lambda x: 2*x + + >>> tree = [inc, (dec, double)] # either inc or dec-then-double + >>> fn = greedy(tree) + >>> fn(4) # lowest value comes from the inc + 5 + >>> fn(1) # lowest value comes from dec then double + 0 + + This function selects between options in a tuple. The result is chosen + that minimizes the objective function. + + >>> fn = greedy(tree, objective=lambda x: -x) # maximize + >>> fn(4) # highest value comes from the dec then double + 6 + >>> fn(1) # highest value comes from the inc + 2 + + Greediness + ---------- + + This is a greedy algorithm. In the example: + + ([a, b], c) # do either a or b, then do c + + the choice between running ``a`` or ``b`` is made without foresight to c + """ + optimize = partial(minimize, objective=objective) + return treeapply(tree, {list: optimize, tuple: chain}, **kwargs) + + +def allresults(tree, leaf=yieldify): + """ Execute a strategic tree. Return all possibilities. + + Returns a lazy iterator of all possible results + + Exhaustiveness + -------------- + + This is an exhaustive algorithm. In the example + + ([a, b], [c, d]) + + All of the results from + + (a, c), (b, c), (a, d), (b, d) + + are returned. This can lead to combinatorial blowup. + + See sympy.strategies.greedy for details on input + """ + return treeapply(tree, {list: branch.multiplex, tuple: branch.chain}, + leaf=leaf) + + +def brute(tree, objective=identity, **kwargs): + return lambda expr: min(tuple(allresults(tree, **kwargs)(expr)), + key=objective) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/util.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/util.py new file mode 100644 index 0000000000000000000000000000000000000000..13aab5f6a49650c5ded9cd913c23c6682f18d40a --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/strategies/util.py @@ -0,0 +1,17 @@ +from sympy.core.basic import Basic + +new = Basic.__new__ + + +def assoc(d, k, v): + d = d.copy() + d[k] = v + return d + + +basic_fns = {'op': type, + 'new': Basic.__new__, + 'leaf': lambda x: not isinstance(x, Basic) or x.is_Atom, + 'children': lambda x: x.args} + +expr_fns = assoc(basic_fns, 'new', lambda op, *args: op(*args)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..a832614b1d48e26bf01e16f040f34dd412e8e32b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/__init__.py @@ -0,0 +1,23 @@ +"""A module to manipulate symbolic objects with indices including tensors + +""" +from .indexed import IndexedBase, Idx, Indexed +from .index_methods import get_contraction_structure, get_indices +from .functions import shape +from .array import (MutableDenseNDimArray, ImmutableDenseNDimArray, + MutableSparseNDimArray, ImmutableSparseNDimArray, NDimArray, tensorproduct, + tensorcontraction, tensordiagonal, derive_by_array, permutedims, Array, + DenseNDimArray, SparseNDimArray,) + +__all__ = [ + 'IndexedBase', 'Idx', 'Indexed', + + 'get_contraction_structure', 'get_indices', + + 'shape', + + 'MutableDenseNDimArray', 'ImmutableDenseNDimArray', + 'MutableSparseNDimArray', 'ImmutableSparseNDimArray', 'NDimArray', + 'tensorproduct', 'tensorcontraction', 'tensordiagonal', 'derive_by_array', 'permutedims', + 'Array', 'DenseNDimArray', 'SparseNDimArray', +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..eca2eb4c6c58cb113517b6e41737e9d97abbb84e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/__init__.py @@ -0,0 +1,271 @@ +r""" +N-dim array module for SymPy. + +Four classes are provided to handle N-dim arrays, given by the combinations +dense/sparse (i.e. whether to store all elements or only the non-zero ones in +memory) and mutable/immutable (immutable classes are SymPy objects, but cannot +change after they have been created). + +Examples +======== + +The following examples show the usage of ``Array``. This is an abbreviation for +``ImmutableDenseNDimArray``, that is an immutable and dense N-dim array, the +other classes are analogous. For mutable classes it is also possible to change +element values after the object has been constructed. + +Array construction can detect the shape of nested lists and tuples: + +>>> from sympy import Array +>>> a1 = Array([[1, 2], [3, 4], [5, 6]]) +>>> a1 +[[1, 2], [3, 4], [5, 6]] +>>> a1.shape +(3, 2) +>>> a1.rank() +2 +>>> from sympy.abc import x, y, z +>>> a2 = Array([[[x, y], [z, x*z]], [[1, x*y], [1/x, x/y]]]) +>>> a2 +[[[x, y], [z, x*z]], [[1, x*y], [1/x, x/y]]] +>>> a2.shape +(2, 2, 2) +>>> a2.rank() +3 + +Otherwise one could pass a 1-dim array followed by a shape tuple: + +>>> m1 = Array(range(12), (3, 4)) +>>> m1 +[[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]] +>>> m2 = Array(range(12), (3, 2, 2)) +>>> m2 +[[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]]] +>>> m2[1,1,1] +7 +>>> m2.reshape(4, 3) +[[0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11]] + +Slice support: + +>>> m2[:, 1, 1] +[3, 7, 11] + +Elementwise derivative: + +>>> from sympy.abc import x, y, z +>>> m3 = Array([x**3, x*y, z]) +>>> m3.diff(x) +[3*x**2, y, 0] +>>> m3.diff(z) +[0, 0, 1] + +Multiplication with other SymPy expressions is applied elementwisely: + +>>> (1+x)*m3 +[x**3*(x + 1), x*y*(x + 1), z*(x + 1)] + +To apply a function to each element of the N-dim array, use ``applyfunc``: + +>>> m3.applyfunc(lambda x: x/2) +[x**3/2, x*y/2, z/2] + +N-dim arrays can be converted to nested lists by the ``tolist()`` method: + +>>> m2.tolist() +[[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]]] +>>> isinstance(m2.tolist(), list) +True + +If the rank is 2, it is possible to convert them to matrices with ``tomatrix()``: + +>>> m1.tomatrix() +Matrix([ +[0, 1, 2, 3], +[4, 5, 6, 7], +[8, 9, 10, 11]]) + +Products and contractions +------------------------- + +Tensor product between arrays `A_{i_1,\ldots,i_n}` and `B_{j_1,\ldots,j_m}` +creates the combined array `P = A \otimes B` defined as + +`P_{i_1,\ldots,i_n,j_1,\ldots,j_m} := A_{i_1,\ldots,i_n}\cdot B_{j_1,\ldots,j_m}.` + +It is available through ``tensorproduct(...)``: + +>>> from sympy import Array, tensorproduct +>>> from sympy.abc import x,y,z,t +>>> A = Array([x, y, z, t]) +>>> B = Array([1, 2, 3, 4]) +>>> tensorproduct(A, B) +[[x, 2*x, 3*x, 4*x], [y, 2*y, 3*y, 4*y], [z, 2*z, 3*z, 4*z], [t, 2*t, 3*t, 4*t]] + +In case you don't want to evaluate the tensor product immediately, you can use +``ArrayTensorProduct``, which creates an unevaluated tensor product expression: + +>>> from sympy.tensor.array.expressions import ArrayTensorProduct +>>> ArrayTensorProduct(A, B) +ArrayTensorProduct([x, y, z, t], [1, 2, 3, 4]) + +Calling ``.as_explicit()`` on ``ArrayTensorProduct`` is equivalent to just calling +``tensorproduct(...)``: + +>>> ArrayTensorProduct(A, B).as_explicit() +[[x, 2*x, 3*x, 4*x], [y, 2*y, 3*y, 4*y], [z, 2*z, 3*z, 4*z], [t, 2*t, 3*t, 4*t]] + +Tensor product between a rank-1 array and a matrix creates a rank-3 array: + +>>> from sympy import eye +>>> p1 = tensorproduct(A, eye(4)) +>>> p1 +[[[x, 0, 0, 0], [0, x, 0, 0], [0, 0, x, 0], [0, 0, 0, x]], [[y, 0, 0, 0], [0, y, 0, 0], [0, 0, y, 0], [0, 0, 0, y]], [[z, 0, 0, 0], [0, z, 0, 0], [0, 0, z, 0], [0, 0, 0, z]], [[t, 0, 0, 0], [0, t, 0, 0], [0, 0, t, 0], [0, 0, 0, t]]] + +Now, to get back `A_0 \otimes \mathbf{1}` one can access `p_{0,m,n}` by slicing: + +>>> p1[0,:,:] +[[x, 0, 0, 0], [0, x, 0, 0], [0, 0, x, 0], [0, 0, 0, x]] + +Tensor contraction sums over the specified axes, for example contracting +positions `a` and `b` means + +`A_{i_1,\ldots,i_a,\ldots,i_b,\ldots,i_n} \implies \sum_k A_{i_1,\ldots,k,\ldots,k,\ldots,i_n}` + +Remember that Python indexing is zero starting, to contract the a-th and b-th +axes it is therefore necessary to specify `a-1` and `b-1` + +>>> from sympy import tensorcontraction +>>> C = Array([[x, y], [z, t]]) + +The matrix trace is equivalent to the contraction of a rank-2 array: + +`A_{m,n} \implies \sum_k A_{k,k}` + +>>> tensorcontraction(C, (0, 1)) +t + x + +To create an expression representing a tensor contraction that does not get +evaluated immediately, use ``ArrayContraction``, which is equivalent to +``tensorcontraction(...)`` if it is followed by ``.as_explicit()``: + +>>> from sympy.tensor.array.expressions import ArrayContraction +>>> ArrayContraction(C, (0, 1)) +ArrayContraction([[x, y], [z, t]], (0, 1)) +>>> ArrayContraction(C, (0, 1)).as_explicit() +t + x + +Matrix product is equivalent to a tensor product of two rank-2 arrays, followed +by a contraction of the 2nd and 3rd axes (in Python indexing axes number 1, 2). + +`A_{m,n}\cdot B_{i,j} \implies \sum_k A_{m, k}\cdot B_{k, j}` + +>>> D = Array([[2, 1], [0, -1]]) +>>> tensorcontraction(tensorproduct(C, D), (1, 2)) +[[2*x, x - y], [2*z, -t + z]] + +One may verify that the matrix product is equivalent: + +>>> from sympy import Matrix +>>> Matrix([[x, y], [z, t]])*Matrix([[2, 1], [0, -1]]) +Matrix([ +[2*x, x - y], +[2*z, -t + z]]) + +or equivalently + +>>> C.tomatrix()*D.tomatrix() +Matrix([ +[2*x, x - y], +[2*z, -t + z]]) + +Diagonal operator +----------------- + +The ``tensordiagonal`` function acts in a similar manner as ``tensorcontraction``, +but the joined indices are not summed over, for example diagonalizing +positions `a` and `b` means + +`A_{i_1,\ldots,i_a,\ldots,i_b,\ldots,i_n} \implies A_{i_1,\ldots,k,\ldots,k,\ldots,i_n} +\implies \tilde{A}_{i_1,\ldots,i_{a-1},i_{a+1},\ldots,i_{b-1},i_{b+1},\ldots,i_n,k}` + +where `\tilde{A}` is the array equivalent to the diagonal of `A` at positions +`a` and `b` moved to the last index slot. + +Compare the difference between contraction and diagonal operators: + +>>> from sympy import tensordiagonal +>>> from sympy.abc import a, b, c, d +>>> m = Matrix([[a, b], [c, d]]) +>>> tensorcontraction(m, [0, 1]) +a + d +>>> tensordiagonal(m, [0, 1]) +[a, d] + +In short, no summation occurs with ``tensordiagonal``. + + +Derivatives by array +-------------------- + +The usual derivative operation may be extended to support derivation with +respect to arrays, provided that all elements in the that array are symbols or +expressions suitable for derivations. + +The definition of a derivative by an array is as follows: given the array +`A_{i_1, \ldots, i_N}` and the array `X_{j_1, \ldots, j_M}` +the derivative of arrays will return a new array `B` defined by + +`B_{j_1,\ldots,j_M,i_1,\ldots,i_N} := \frac{\partial A_{i_1,\ldots,i_N}}{\partial X_{j_1,\ldots,j_M}}` + +The function ``derive_by_array`` performs such an operation: + +>>> from sympy import derive_by_array +>>> from sympy.abc import x, y, z, t +>>> from sympy import sin, exp + +With scalars, it behaves exactly as the ordinary derivative: + +>>> derive_by_array(sin(x*y), x) +y*cos(x*y) + +Scalar derived by an array basis: + +>>> derive_by_array(sin(x*y), [x, y, z]) +[y*cos(x*y), x*cos(x*y), 0] + +Deriving array by an array basis: `B^{nm} := \frac{\partial A^m}{\partial x^n}` + +>>> basis = [x, y, z] +>>> ax = derive_by_array([exp(x), sin(y*z), t], basis) +>>> ax +[[exp(x), 0, 0], [0, z*cos(y*z), 0], [0, y*cos(y*z), 0]] + +Contraction of the resulting array: `\sum_m \frac{\partial A^m}{\partial x^m}` + +>>> tensorcontraction(ax, (0, 1)) +z*cos(y*z) + exp(x) + +""" + +from .dense_ndim_array import MutableDenseNDimArray, ImmutableDenseNDimArray, DenseNDimArray +from .sparse_ndim_array import MutableSparseNDimArray, ImmutableSparseNDimArray, SparseNDimArray +from .ndim_array import NDimArray, ArrayKind +from .arrayop import tensorproduct, tensorcontraction, tensordiagonal, derive_by_array, permutedims +from .array_comprehension import ArrayComprehension, ArrayComprehensionMap + +Array = ImmutableDenseNDimArray + +__all__ = [ + 'MutableDenseNDimArray', 'ImmutableDenseNDimArray', 'DenseNDimArray', + + 'MutableSparseNDimArray', 'ImmutableSparseNDimArray', 'SparseNDimArray', + + 'NDimArray', 'ArrayKind', + + 'tensorproduct', 'tensorcontraction', 'tensordiagonal', 'derive_by_array', + + 'permutedims', 'ArrayComprehension', 'ArrayComprehensionMap', + + 'Array', +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/array_comprehension.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/array_comprehension.py new file mode 100644 index 0000000000000000000000000000000000000000..95702f499f3e40597fd0144929138ac1329962ee --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/array_comprehension.py @@ -0,0 +1,399 @@ +import functools, itertools +from sympy.core.sympify import _sympify, sympify +from sympy.core.expr import Expr +from sympy.core import Basic, Tuple +from sympy.tensor.array import ImmutableDenseNDimArray +from sympy.core.symbol import Symbol +from sympy.core.numbers import Integer + + +class ArrayComprehension(Basic): + """ + Generate a list comprehension. + + Explanation + =========== + + If there is a symbolic dimension, for example, say [i for i in range(1, N)] where + N is a Symbol, then the expression will not be expanded to an array. Otherwise, + calling the doit() function will launch the expansion. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a + ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.doit() + [[11, 12, 13], [21, 22, 23], [31, 32, 33], [41, 42, 43]] + >>> b = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, k)) + >>> b.doit() + ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, k)) + """ + def __new__(cls, function, *symbols, **assumptions): + if any(len(l) != 3 or None for l in symbols): + raise ValueError('ArrayComprehension requires values lower and upper bound' + ' for the expression') + arglist = [sympify(function)] + arglist.extend(cls._check_limits_validity(function, symbols)) + obj = Basic.__new__(cls, *arglist, **assumptions) + obj._limits = obj._args[1:] + obj._shape = cls._calculate_shape_from_limits(obj._limits) + obj._rank = len(obj._shape) + obj._loop_size = cls._calculate_loop_size(obj._shape) + return obj + + @property + def function(self): + """The function applied across limits. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j = symbols('i j') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.function + 10*i + j + """ + return self._args[0] + + @property + def limits(self): + """ + The list of limits that will be applied while expanding the array. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j = symbols('i j') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.limits + ((i, 1, 4), (j, 1, 3)) + """ + return self._limits + + @property + def free_symbols(self): + """ + The set of the free_symbols in the array. + Variables appeared in the bounds are supposed to be excluded + from the free symbol set. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.free_symbols + set() + >>> b = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, k+3)) + >>> b.free_symbols + {k} + """ + expr_free_sym = self.function.free_symbols + for var, inf, sup in self._limits: + expr_free_sym.discard(var) + curr_free_syms = inf.free_symbols.union(sup.free_symbols) + expr_free_sym = expr_free_sym.union(curr_free_syms) + return expr_free_sym + + @property + def variables(self): + """The tuples of the variables in the limits. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.variables + [i, j] + """ + return [l[0] for l in self._limits] + + @property + def bound_symbols(self): + """The list of dummy variables. + + Note + ==== + + Note that all variables are dummy variables since a limit without + lower bound or upper bound is not accepted. + """ + return [l[0] for l in self._limits if len(l) != 1] + + @property + def shape(self): + """ + The shape of the expanded array, which may have symbols. + + Note + ==== + + Both the lower and the upper bounds are included while + calculating the shape. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.shape + (4, 3) + >>> b = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, k+3)) + >>> b.shape + (4, k + 3) + """ + return self._shape + + @property + def is_shape_numeric(self): + """ + Test if the array is shape-numeric which means there is no symbolic + dimension. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.is_shape_numeric + True + >>> b = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, k+3)) + >>> b.is_shape_numeric + False + """ + for _, inf, sup in self._limits: + if Basic(inf, sup).atoms(Symbol): + return False + return True + + def rank(self): + """The rank of the expanded array. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.rank() + 2 + """ + return self._rank + + def __len__(self): + """ + The length of the expanded array which means the number + of elements in the array. + + Raises + ====== + + ValueError : When the length of the array is symbolic + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j = symbols('i j') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> len(a) + 12 + """ + if self._loop_size.free_symbols: + raise ValueError('Symbolic length is not supported') + return self._loop_size + + @classmethod + def _check_limits_validity(cls, function, limits): + #limits = sympify(limits) + new_limits = [] + for var, inf, sup in limits: + var = _sympify(var) + inf = _sympify(inf) + #since this is stored as an argument, it should be + #a Tuple + if isinstance(sup, list): + sup = Tuple(*sup) + else: + sup = _sympify(sup) + new_limits.append(Tuple(var, inf, sup)) + if any((not isinstance(i, Expr)) or i.atoms(Symbol, Integer) != i.atoms() + for i in [inf, sup]): + raise TypeError('Bounds should be an Expression(combination of Integer and Symbol)') + if (inf > sup) == True: + raise ValueError('Lower bound should be inferior to upper bound') + if var in inf.free_symbols or var in sup.free_symbols: + raise ValueError('Variable should not be part of its bounds') + return new_limits + + @classmethod + def _calculate_shape_from_limits(cls, limits): + return tuple([sup - inf + 1 for _, inf, sup in limits]) + + @classmethod + def _calculate_loop_size(cls, shape): + if not shape: + return 0 + loop_size = 1 + for l in shape: + loop_size = loop_size * l + + return loop_size + + def doit(self, **hints): + if not self.is_shape_numeric: + return self + + return self._expand_array() + + def _expand_array(self): + res = [] + for values in itertools.product(*[range(inf, sup+1) + for var, inf, sup + in self._limits]): + res.append(self._get_element(values)) + + return ImmutableDenseNDimArray(res, self.shape) + + def _get_element(self, values): + temp = self.function + for var, val in zip(self.variables, values): + temp = temp.subs(var, val) + return temp + + def tolist(self): + """Transform the expanded array to a list. + + Raises + ====== + + ValueError : When there is a symbolic dimension + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j = symbols('i j') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.tolist() + [[11, 12, 13], [21, 22, 23], [31, 32, 33], [41, 42, 43]] + """ + if self.is_shape_numeric: + return self._expand_array().tolist() + + raise ValueError("A symbolic array cannot be expanded to a list") + + def tomatrix(self): + """Transform the expanded array to a matrix. + + Raises + ====== + + ValueError : When there is a symbolic dimension + ValueError : When the rank of the expanded array is not equal to 2 + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehension + >>> from sympy import symbols + >>> i, j = symbols('i j') + >>> a = ArrayComprehension(10*i + j, (i, 1, 4), (j, 1, 3)) + >>> a.tomatrix() + Matrix([ + [11, 12, 13], + [21, 22, 23], + [31, 32, 33], + [41, 42, 43]]) + """ + from sympy.matrices import Matrix + + if not self.is_shape_numeric: + raise ValueError("A symbolic array cannot be expanded to a matrix") + if self._rank != 2: + raise ValueError('Dimensions must be of size of 2') + + return Matrix(self._expand_array().tomatrix()) + + +def isLambda(v): + LAMBDA = lambda: 0 + return isinstance(v, type(LAMBDA)) and v.__name__ == LAMBDA.__name__ + +class ArrayComprehensionMap(ArrayComprehension): + ''' + A subclass of ArrayComprehension dedicated to map external function lambda. + + Notes + ===== + + Only the lambda function is considered. + At most one argument in lambda function is accepted in order to avoid ambiguity + in value assignment. + + Examples + ======== + + >>> from sympy.tensor.array import ArrayComprehensionMap + >>> from sympy import symbols + >>> i, j, k = symbols('i j k') + >>> a = ArrayComprehensionMap(lambda: 1, (i, 1, 4)) + >>> a.doit() + [1, 1, 1, 1] + >>> b = ArrayComprehensionMap(lambda a: a+1, (j, 1, 4)) + >>> b.doit() + [2, 3, 4, 5] + + ''' + def __new__(cls, function, *symbols, **assumptions): + if any(len(l) != 3 or None for l in symbols): + raise ValueError('ArrayComprehension requires values lower and upper bound' + ' for the expression') + + if not isLambda(function): + raise ValueError('Data type not supported') + + arglist = cls._check_limits_validity(function, symbols) + obj = Basic.__new__(cls, *arglist, **assumptions) + obj._limits = obj._args + obj._shape = cls._calculate_shape_from_limits(obj._limits) + obj._rank = len(obj._shape) + obj._loop_size = cls._calculate_loop_size(obj._shape) + obj._lambda = function + return obj + + @property + def func(self): + class _(ArrayComprehensionMap): + def __new__(cls, *args, **kwargs): + return ArrayComprehensionMap(self._lambda, *args, **kwargs) + return _ + + def _get_element(self, values): + temp = self._lambda + if self._lambda.__code__.co_argcount == 0: + temp = temp() + elif self._lambda.__code__.co_argcount == 1: + temp = temp(functools.reduce(lambda a, b: a*b, values)) + return temp diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/array_derivatives.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/array_derivatives.py new file mode 100644 index 0000000000000000000000000000000000000000..a38db6caefe256a8c7e1f3415b78351b3787fee9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/array_derivatives.py @@ -0,0 +1,129 @@ +from __future__ import annotations + +from sympy.core.expr import Expr +from sympy.core.function import Derivative +from sympy.core.numbers import Integer +from sympy.matrices.matrixbase import MatrixBase +from .ndim_array import NDimArray +from .arrayop import derive_by_array +from sympy.matrices.expressions.matexpr import MatrixExpr +from sympy.matrices.expressions.special import ZeroMatrix +from sympy.matrices.expressions.matexpr import _matrix_derivative + + +class ArrayDerivative(Derivative): + + is_scalar = False + + def __new__(cls, expr, *variables, **kwargs): + obj = super().__new__(cls, expr, *variables, **kwargs) + if isinstance(obj, ArrayDerivative): + obj._shape = obj._get_shape() + return obj + + def _get_shape(self): + shape = () + for v, count in self.variable_count: + if hasattr(v, "shape"): + for i in range(count): + shape += v.shape + if hasattr(self.expr, "shape"): + shape += self.expr.shape + return shape + + @property + def shape(self): + return self._shape + + @classmethod + def _get_zero_with_shape_like(cls, expr): + if isinstance(expr, (MatrixBase, NDimArray)): + return expr.zeros(*expr.shape) + elif isinstance(expr, MatrixExpr): + return ZeroMatrix(*expr.shape) + else: + raise RuntimeError("Unable to determine shape of array-derivative.") + + @staticmethod + def _call_derive_scalar_by_matrix(expr: Expr, v: MatrixBase) -> Expr: + return v.applyfunc(lambda x: expr.diff(x)) + + @staticmethod + def _call_derive_scalar_by_matexpr(expr: Expr, v: MatrixExpr) -> Expr: + if expr.has(v): + return _matrix_derivative(expr, v) + else: + return ZeroMatrix(*v.shape) + + @staticmethod + def _call_derive_scalar_by_array(expr: Expr, v: NDimArray) -> Expr: + return v.applyfunc(lambda x: expr.diff(x)) + + @staticmethod + def _call_derive_matrix_by_scalar(expr: MatrixBase, v: Expr) -> Expr: + return _matrix_derivative(expr, v) + + @staticmethod + def _call_derive_matexpr_by_scalar(expr: MatrixExpr, v: Expr) -> Expr: + return expr._eval_derivative(v) + + @staticmethod + def _call_derive_array_by_scalar(expr: NDimArray, v: Expr) -> Expr: + return expr.applyfunc(lambda x: x.diff(v)) + + @staticmethod + def _call_derive_default(expr: Expr, v: Expr) -> Expr | None: + if expr.has(v): + return _matrix_derivative(expr, v) + else: + return None + + @classmethod + def _dispatch_eval_derivative_n_times(cls, expr, v, count): + # Evaluate the derivative `n` times. If + # `_eval_derivative_n_times` is not overridden by the current + # object, the default in `Basic` will call a loop over + # `_eval_derivative`: + + if not isinstance(count, (int, Integer)) or ((count <= 0) == True): + return None + + # TODO: this could be done with multiple-dispatching: + if expr.is_scalar: + if isinstance(v, MatrixBase): + result = cls._call_derive_scalar_by_matrix(expr, v) + elif isinstance(v, MatrixExpr): + result = cls._call_derive_scalar_by_matexpr(expr, v) + elif isinstance(v, NDimArray): + result = cls._call_derive_scalar_by_array(expr, v) + elif v.is_scalar: + # scalar by scalar has a special + return super()._dispatch_eval_derivative_n_times(expr, v, count) + else: + return None + elif v.is_scalar: + if isinstance(expr, MatrixBase): + result = cls._call_derive_matrix_by_scalar(expr, v) + elif isinstance(expr, MatrixExpr): + result = cls._call_derive_matexpr_by_scalar(expr, v) + elif isinstance(expr, NDimArray): + result = cls._call_derive_array_by_scalar(expr, v) + else: + return None + else: + # Both `expr` and `v` are some array/matrix type: + if isinstance(expr, MatrixBase) or isinstance(v, MatrixBase): + result = derive_by_array(expr, v) + elif isinstance(expr, MatrixExpr) and isinstance(v, MatrixExpr): + result = cls._call_derive_default(expr, v) + elif isinstance(expr, MatrixExpr) or isinstance(v, MatrixExpr): + # if one expression is a symbolic matrix expression while the other isn't, don't evaluate: + return None + else: + result = derive_by_array(expr, v) + if result is None: + return None + if count == 1: + return result + else: + return cls._dispatch_eval_derivative_n_times(result, v, count - 1) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/arrayop.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/arrayop.py new file mode 100644 index 0000000000000000000000000000000000000000..a81e6b381a8a93f0cd585278a4be0259b06406dd --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/arrayop.py @@ -0,0 +1,528 @@ +import itertools +from collections.abc import Iterable + +from sympy.core._print_helpers import Printable +from sympy.core.containers import Tuple +from sympy.core.function import diff +from sympy.core.singleton import S +from sympy.core.sympify import _sympify + +from sympy.tensor.array.ndim_array import NDimArray +from sympy.tensor.array.dense_ndim_array import DenseNDimArray, ImmutableDenseNDimArray +from sympy.tensor.array.sparse_ndim_array import SparseNDimArray + + +def _arrayfy(a): + from sympy.matrices import MatrixBase + + if isinstance(a, NDimArray): + return a + if isinstance(a, (MatrixBase, list, tuple, Tuple)): + return ImmutableDenseNDimArray(a) + return a + + +def tensorproduct(*args): + """ + Tensor product among scalars or array-like objects. + + The equivalent operator for array expressions is ``ArrayTensorProduct``, + which can be used to keep the expression unevaluated. + + Examples + ======== + + >>> from sympy.tensor.array import tensorproduct, Array + >>> from sympy.abc import x, y, z, t + >>> A = Array([[1, 2], [3, 4]]) + >>> B = Array([x, y]) + >>> tensorproduct(A, B) + [[[x, y], [2*x, 2*y]], [[3*x, 3*y], [4*x, 4*y]]] + >>> tensorproduct(A, x) + [[x, 2*x], [3*x, 4*x]] + >>> tensorproduct(A, B, B) + [[[[x**2, x*y], [x*y, y**2]], [[2*x**2, 2*x*y], [2*x*y, 2*y**2]]], [[[3*x**2, 3*x*y], [3*x*y, 3*y**2]], [[4*x**2, 4*x*y], [4*x*y, 4*y**2]]]] + + Applying this function on two matrices will result in a rank 4 array. + + >>> from sympy import Matrix, eye + >>> m = Matrix([[x, y], [z, t]]) + >>> p = tensorproduct(eye(3), m) + >>> p + [[[[x, y], [z, t]], [[0, 0], [0, 0]], [[0, 0], [0, 0]]], [[[0, 0], [0, 0]], [[x, y], [z, t]], [[0, 0], [0, 0]]], [[[0, 0], [0, 0]], [[0, 0], [0, 0]], [[x, y], [z, t]]]] + + See Also + ======== + + sympy.tensor.array.expressions.array_expressions.ArrayTensorProduct + + """ + from sympy.tensor.array import SparseNDimArray, ImmutableSparseNDimArray + + if len(args) == 0: + return S.One + if len(args) == 1: + return _arrayfy(args[0]) + from sympy.tensor.array.expressions.array_expressions import _CodegenArrayAbstract + from sympy.tensor.array.expressions.array_expressions import ArrayTensorProduct + from sympy.tensor.array.expressions.array_expressions import _ArrayExpr + from sympy.matrices.expressions.matexpr import MatrixSymbol + if any(isinstance(arg, (_ArrayExpr, _CodegenArrayAbstract, MatrixSymbol)) for arg in args): + return ArrayTensorProduct(*args) + if len(args) > 2: + return tensorproduct(tensorproduct(args[0], args[1]), *args[2:]) + + # length of args is 2: + a, b = map(_arrayfy, args) + + if not isinstance(a, NDimArray) or not isinstance(b, NDimArray): + return a*b + + if isinstance(a, SparseNDimArray) and isinstance(b, SparseNDimArray): + lp = len(b) + new_array = {k1*lp + k2: v1*v2 for k1, v1 in a._sparse_array.items() for k2, v2 in b._sparse_array.items()} + return ImmutableSparseNDimArray(new_array, a.shape + b.shape) + + product_list = [i*j for i in Flatten(a) for j in Flatten(b)] + return ImmutableDenseNDimArray(product_list, a.shape + b.shape) + + +def _util_contraction_diagonal(array, *contraction_or_diagonal_axes): + array = _arrayfy(array) + + # Verify contraction_axes: + taken_dims = set() + for axes_group in contraction_or_diagonal_axes: + if not isinstance(axes_group, Iterable): + raise ValueError("collections of contraction/diagonal axes expected") + + dim = array.shape[axes_group[0]] + + for d in axes_group: + if d in taken_dims: + raise ValueError("dimension specified more than once") + if dim != array.shape[d]: + raise ValueError("cannot contract or diagonalize between axes of different dimension") + taken_dims.add(d) + + rank = array.rank() + + remaining_shape = [dim for i, dim in enumerate(array.shape) if i not in taken_dims] + cum_shape = [0]*rank + _cumul = 1 + for i in range(rank): + cum_shape[rank - i - 1] = _cumul + _cumul *= int(array.shape[rank - i - 1]) + + # DEFINITION: by absolute position it is meant the position along the one + # dimensional array containing all the tensor components. + + # Possible future work on this module: move computation of absolute + # positions to a class method. + + # Determine absolute positions of the uncontracted indices: + remaining_indices = [[cum_shape[i]*j for j in range(array.shape[i])] + for i in range(rank) if i not in taken_dims] + + # Determine absolute positions of the contracted indices: + summed_deltas = [] + for axes_group in contraction_or_diagonal_axes: + lidx = [] + for js in range(array.shape[axes_group[0]]): + lidx.append(sum(cum_shape[ig] * js for ig in axes_group)) + summed_deltas.append(lidx) + + return array, remaining_indices, remaining_shape, summed_deltas + + +def tensorcontraction(array, *contraction_axes): + """ + Contraction of an array-like object on the specified axes. + + The equivalent operator for array expressions is ``ArrayContraction``, + which can be used to keep the expression unevaluated. + + Examples + ======== + + >>> from sympy import Array, tensorcontraction + >>> from sympy import Matrix, eye + >>> tensorcontraction(eye(3), (0, 1)) + 3 + >>> A = Array(range(18), (3, 2, 3)) + >>> A + [[[0, 1, 2], [3, 4, 5]], [[6, 7, 8], [9, 10, 11]], [[12, 13, 14], [15, 16, 17]]] + >>> tensorcontraction(A, (0, 2)) + [21, 30] + + Matrix multiplication may be emulated with a proper combination of + ``tensorcontraction`` and ``tensorproduct`` + + >>> from sympy import tensorproduct + >>> from sympy.abc import a,b,c,d,e,f,g,h + >>> m1 = Matrix([[a, b], [c, d]]) + >>> m2 = Matrix([[e, f], [g, h]]) + >>> p = tensorproduct(m1, m2) + >>> p + [[[[a*e, a*f], [a*g, a*h]], [[b*e, b*f], [b*g, b*h]]], [[[c*e, c*f], [c*g, c*h]], [[d*e, d*f], [d*g, d*h]]]] + >>> tensorcontraction(p, (1, 2)) + [[a*e + b*g, a*f + b*h], [c*e + d*g, c*f + d*h]] + >>> m1*m2 + Matrix([ + [a*e + b*g, a*f + b*h], + [c*e + d*g, c*f + d*h]]) + + See Also + ======== + + sympy.tensor.array.expressions.array_expressions.ArrayContraction + + """ + from sympy.tensor.array.expressions.array_expressions import _array_contraction + from sympy.tensor.array.expressions.array_expressions import _CodegenArrayAbstract + from sympy.tensor.array.expressions.array_expressions import _ArrayExpr + from sympy.matrices.expressions.matexpr import MatrixSymbol + if isinstance(array, (_ArrayExpr, _CodegenArrayAbstract, MatrixSymbol)): + return _array_contraction(array, *contraction_axes) + + array, remaining_indices, remaining_shape, summed_deltas = _util_contraction_diagonal(array, *contraction_axes) + + # Compute the contracted array: + # + # 1. external for loops on all uncontracted indices. + # Uncontracted indices are determined by the combinatorial product of + # the absolute positions of the remaining indices. + # 2. internal loop on all contracted indices. + # It sums the values of the absolute contracted index and the absolute + # uncontracted index for the external loop. + contracted_array = [] + for icontrib in itertools.product(*remaining_indices): + index_base_position = sum(icontrib) + isum = S.Zero + for sum_to_index in itertools.product(*summed_deltas): + idx = array._get_tuple_index(index_base_position + sum(sum_to_index)) + isum += array[idx] + + contracted_array.append(isum) + + if len(remaining_indices) == 0: + assert len(contracted_array) == 1 + return contracted_array[0] + + return type(array)(contracted_array, remaining_shape) + + +def tensordiagonal(array, *diagonal_axes): + """ + Diagonalization of an array-like object on the specified axes. + + This is equivalent to multiplying the expression by Kronecker deltas + uniting the axes. + + The diagonal indices are put at the end of the axes. + + The equivalent operator for array expressions is ``ArrayDiagonal``, which + can be used to keep the expression unevaluated. + + Examples + ======== + + ``tensordiagonal`` acting on a 2-dimensional array by axes 0 and 1 is + equivalent to the diagonal of the matrix: + + >>> from sympy import Array, tensordiagonal + >>> from sympy import Matrix, eye + >>> tensordiagonal(eye(3), (0, 1)) + [1, 1, 1] + + >>> from sympy.abc import a,b,c,d + >>> m1 = Matrix([[a, b], [c, d]]) + >>> tensordiagonal(m1, [0, 1]) + [a, d] + + In case of higher dimensional arrays, the diagonalized out dimensions + are appended removed and appended as a single dimension at the end: + + >>> A = Array(range(18), (3, 2, 3)) + >>> A + [[[0, 1, 2], [3, 4, 5]], [[6, 7, 8], [9, 10, 11]], [[12, 13, 14], [15, 16, 17]]] + >>> tensordiagonal(A, (0, 2)) + [[0, 7, 14], [3, 10, 17]] + >>> from sympy import permutedims + >>> tensordiagonal(A, (0, 2)) == permutedims(Array([A[0, :, 0], A[1, :, 1], A[2, :, 2]]), [1, 0]) + True + + See Also + ======== + + sympy.tensor.array.expressions.array_expressions.ArrayDiagonal + + """ + if any(len(i) <= 1 for i in diagonal_axes): + raise ValueError("need at least two axes to diagonalize") + + from sympy.tensor.array.expressions.array_expressions import _ArrayExpr + from sympy.tensor.array.expressions.array_expressions import _CodegenArrayAbstract + from sympy.tensor.array.expressions.array_expressions import ArrayDiagonal, _array_diagonal + from sympy.matrices.expressions.matexpr import MatrixSymbol + if isinstance(array, (_ArrayExpr, _CodegenArrayAbstract, MatrixSymbol)): + return _array_diagonal(array, *diagonal_axes) + + ArrayDiagonal._validate(array, *diagonal_axes) + + array, remaining_indices, remaining_shape, diagonal_deltas = _util_contraction_diagonal(array, *diagonal_axes) + + # Compute the diagonalized array: + # + # 1. external for loops on all undiagonalized indices. + # Undiagonalized indices are determined by the combinatorial product of + # the absolute positions of the remaining indices. + # 2. internal loop on all diagonal indices. + # It appends the values of the absolute diagonalized index and the absolute + # undiagonalized index for the external loop. + diagonalized_array = [] + diagonal_shape = [len(i) for i in diagonal_deltas] + for icontrib in itertools.product(*remaining_indices): + index_base_position = sum(icontrib) + isum = [] + for sum_to_index in itertools.product(*diagonal_deltas): + idx = array._get_tuple_index(index_base_position + sum(sum_to_index)) + isum.append(array[idx]) + + isum = type(array)(isum).reshape(*diagonal_shape) + diagonalized_array.append(isum) + + return type(array)(diagonalized_array, remaining_shape + diagonal_shape) + + +def derive_by_array(expr, dx): + r""" + Derivative by arrays. Supports both arrays and scalars. + + The equivalent operator for array expressions is ``array_derive``. + + Explanation + =========== + + Given the array `A_{i_1, \ldots, i_N}` and the array `X_{j_1, \ldots, j_M}` + this function will return a new array `B` defined by + + `B_{j_1,\ldots,j_M,i_1,\ldots,i_N} := \frac{\partial A_{i_1,\ldots,i_N}}{\partial X_{j_1,\ldots,j_M}}` + + Examples + ======== + + >>> from sympy import derive_by_array + >>> from sympy.abc import x, y, z, t + >>> from sympy import cos + >>> derive_by_array(cos(x*t), x) + -t*sin(t*x) + >>> derive_by_array(cos(x*t), [x, y, z, t]) + [-t*sin(t*x), 0, 0, -x*sin(t*x)] + >>> derive_by_array([x, y**2*z], [[x, y], [z, t]]) + [[[1, 0], [0, 2*y*z]], [[0, y**2], [0, 0]]] + + """ + from sympy.matrices import MatrixBase + from sympy.tensor.array import SparseNDimArray + array_types = (Iterable, MatrixBase, NDimArray) + + if isinstance(dx, array_types): + dx = ImmutableDenseNDimArray(dx) + for i in dx: + if not i._diff_wrt: + raise ValueError("cannot derive by this array") + + if isinstance(expr, array_types): + if isinstance(expr, NDimArray): + expr = expr.as_immutable() + else: + expr = ImmutableDenseNDimArray(expr) + + if isinstance(dx, array_types): + if isinstance(expr, SparseNDimArray): + lp = len(expr) + new_array = {k + i*lp: v + for i, x in enumerate(Flatten(dx)) + for k, v in expr.diff(x)._sparse_array.items()} + else: + new_array = [[y.diff(x) for y in Flatten(expr)] for x in Flatten(dx)] + return type(expr)(new_array, dx.shape + expr.shape) + else: + return expr.diff(dx) + else: + expr = _sympify(expr) + if isinstance(dx, array_types): + return ImmutableDenseNDimArray([expr.diff(i) for i in Flatten(dx)], dx.shape) + else: + dx = _sympify(dx) + return diff(expr, dx) + + +def permutedims(expr, perm=None, index_order_old=None, index_order_new=None): + """ + Permutes the indices of an array. + + Parameter specifies the permutation of the indices. + + The equivalent operator for array expressions is ``PermuteDims``, which can + be used to keep the expression unevaluated. + + Examples + ======== + + >>> from sympy.abc import x, y, z, t + >>> from sympy import sin + >>> from sympy import Array, permutedims + >>> a = Array([[x, y, z], [t, sin(x), 0]]) + >>> a + [[x, y, z], [t, sin(x), 0]] + >>> permutedims(a, (1, 0)) + [[x, t], [y, sin(x)], [z, 0]] + + If the array is of second order, ``transpose`` can be used: + + >>> from sympy import transpose + >>> transpose(a) + [[x, t], [y, sin(x)], [z, 0]] + + Examples on higher dimensions: + + >>> b = Array([[[1, 2], [3, 4]], [[5, 6], [7, 8]]]) + >>> permutedims(b, (2, 1, 0)) + [[[1, 5], [3, 7]], [[2, 6], [4, 8]]] + >>> permutedims(b, (1, 2, 0)) + [[[1, 5], [2, 6]], [[3, 7], [4, 8]]] + + An alternative way to specify the same permutations as in the previous + lines involves passing the *old* and *new* indices, either as a list or as + a string: + + >>> permutedims(b, index_order_old="cba", index_order_new="abc") + [[[1, 5], [3, 7]], [[2, 6], [4, 8]]] + >>> permutedims(b, index_order_old="cab", index_order_new="abc") + [[[1, 5], [2, 6]], [[3, 7], [4, 8]]] + + ``Permutation`` objects are also allowed: + + >>> from sympy.combinatorics import Permutation + >>> permutedims(b, Permutation([1, 2, 0])) + [[[1, 5], [2, 6]], [[3, 7], [4, 8]]] + + See Also + ======== + + sympy.tensor.array.expressions.array_expressions.PermuteDims + + """ + from sympy.tensor.array import SparseNDimArray + + from sympy.tensor.array.expressions.array_expressions import _ArrayExpr + from sympy.tensor.array.expressions.array_expressions import _CodegenArrayAbstract + from sympy.tensor.array.expressions.array_expressions import _permute_dims + from sympy.matrices.expressions.matexpr import MatrixSymbol + from sympy.tensor.array.expressions import PermuteDims + from sympy.tensor.array.expressions.array_expressions import get_rank + perm = PermuteDims._get_permutation_from_arguments(perm, index_order_old, index_order_new, get_rank(expr)) + if isinstance(expr, (_ArrayExpr, _CodegenArrayAbstract, MatrixSymbol)): + return _permute_dims(expr, perm) + + if not isinstance(expr, NDimArray): + expr = ImmutableDenseNDimArray(expr) + + from sympy.combinatorics import Permutation + if not isinstance(perm, Permutation): + perm = Permutation(list(perm)) + + if perm.size != expr.rank(): + raise ValueError("wrong permutation size") + + # Get the inverse permutation: + iperm = ~perm + new_shape = perm(expr.shape) + + if isinstance(expr, SparseNDimArray): + return type(expr)({tuple(perm(expr._get_tuple_index(k))): v + for k, v in expr._sparse_array.items()}, new_shape) + + indices_span = perm([range(i) for i in expr.shape]) + + new_array = [None]*len(expr) + for i, idx in enumerate(itertools.product(*indices_span)): + t = iperm(idx) + new_array[i] = expr[t] + + return type(expr)(new_array, new_shape) + + +class Flatten(Printable): + """ + Flatten an iterable object to a list in a lazy-evaluation way. + + Notes + ===== + + This class is an iterator with which the memory cost can be economised. + Optimisation has been considered to ameliorate the performance for some + specific data types like DenseNDimArray and SparseNDimArray. + + Examples + ======== + + >>> from sympy.tensor.array.arrayop import Flatten + >>> from sympy.tensor.array import Array + >>> A = Array(range(6)).reshape(2, 3) + >>> Flatten(A) + Flatten([[0, 1, 2], [3, 4, 5]]) + >>> [i for i in Flatten(A)] + [0, 1, 2, 3, 4, 5] + """ + def __init__(self, iterable): + from sympy.matrices.matrixbase import MatrixBase + from sympy.tensor.array import NDimArray + + if not isinstance(iterable, (Iterable, MatrixBase)): + raise NotImplementedError("Data type not yet supported") + + if isinstance(iterable, list): + iterable = NDimArray(iterable) + + self._iter = iterable + self._idx = 0 + + def __iter__(self): + return self + + def __next__(self): + from sympy.matrices.matrixbase import MatrixBase + + if len(self._iter) > self._idx: + if isinstance(self._iter, DenseNDimArray): + result = self._iter._array[self._idx] + + elif isinstance(self._iter, SparseNDimArray): + if self._idx in self._iter._sparse_array: + result = self._iter._sparse_array[self._idx] + else: + result = 0 + + elif isinstance(self._iter, MatrixBase): + result = self._iter[self._idx] + + elif hasattr(self._iter, '__next__'): + result = next(self._iter) + + else: + result = self._iter[self._idx] + + else: + raise StopIteration + + self._idx += 1 + return result + + def next(self): + return self.__next__() + + def _sympystr(self, printer): + return type(self).__name__ + '(' + printer._print(self._iter) + ')' diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/dense_ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/dense_ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..576e452c55d8d374ca1f72c553f3a64de7227d43 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/dense_ndim_array.py @@ -0,0 +1,206 @@ +import functools +from typing import List + +from sympy.core.basic import Basic +from sympy.core.containers import Tuple +from sympy.core.singleton import S +from sympy.core.sympify import _sympify +from sympy.tensor.array.mutable_ndim_array import MutableNDimArray +from sympy.tensor.array.ndim_array import NDimArray, ImmutableNDimArray, ArrayKind +from sympy.utilities.iterables import flatten + + +class DenseNDimArray(NDimArray): + + _array: List[Basic] + + def __new__(self, *args, **kwargs): + return ImmutableDenseNDimArray(*args, **kwargs) + + @property + def kind(self) -> ArrayKind: + return ArrayKind._union(self._array) + + def __getitem__(self, index): + """ + Allows to get items from N-dim array. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray([0, 1, 2, 3], (2, 2)) + >>> a + [[0, 1], [2, 3]] + >>> a[0, 0] + 0 + >>> a[1, 1] + 3 + >>> a[0] + [0, 1] + >>> a[1] + [2, 3] + + + Symbolic index: + + >>> from sympy.abc import i, j + >>> a[i, j] + [[0, 1], [2, 3]][i, j] + + Replace `i` and `j` to get element `(1, 1)`: + + >>> a[i, j].subs({i: 1, j: 1}) + 3 + + """ + syindex = self._check_symbolic_index(index) + if syindex is not None: + return syindex + + index = self._check_index_for_getitem(index) + + if isinstance(index, tuple) and any(isinstance(i, slice) for i in index): + sl_factors, eindices = self._get_slice_data_for_array_access(index) + array = [self._array[self._parse_index(i)] for i in eindices] + nshape = [len(el) for i, el in enumerate(sl_factors) if isinstance(index[i], slice)] + return type(self)(array, nshape) + else: + index = self._parse_index(index) + return self._array[index] + + @classmethod + def zeros(cls, *shape): + list_length = functools.reduce(lambda x, y: x*y, shape, S.One) + return cls._new(([0]*list_length,), shape) + + def tomatrix(self): + """ + Converts MutableDenseNDimArray to Matrix. Can convert only 2-dim array, else will raise error. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray([1 for i in range(9)], (3, 3)) + >>> b = a.tomatrix() + >>> b + Matrix([ + [1, 1, 1], + [1, 1, 1], + [1, 1, 1]]) + + """ + from sympy.matrices import Matrix + + if self.rank() != 2: + raise ValueError('Dimensions must be of size of 2') + + return Matrix(self.shape[0], self.shape[1], self._array) + + def reshape(self, *newshape): + """ + Returns MutableDenseNDimArray instance with new shape. Elements number + must be suitable to new shape. The only argument of method sets + new shape. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray([1, 2, 3, 4, 5, 6], (2, 3)) + >>> a.shape + (2, 3) + >>> a + [[1, 2, 3], [4, 5, 6]] + >>> b = a.reshape(3, 2) + >>> b.shape + (3, 2) + >>> b + [[1, 2], [3, 4], [5, 6]] + + """ + new_total_size = functools.reduce(lambda x,y: x*y, newshape) + if new_total_size != self._loop_size: + raise ValueError('Expecting reshape size to %d but got prod(%s) = %d' % ( + self._loop_size, str(newshape), new_total_size)) + + # there is no `.func` as this class does not subtype `Basic`: + return type(self)(self._array, newshape) + + +class ImmutableDenseNDimArray(DenseNDimArray, ImmutableNDimArray): # type: ignore + def __new__(cls, iterable, shape=None, **kwargs): + return cls._new(iterable, shape, **kwargs) + + @classmethod + def _new(cls, iterable, shape, **kwargs): + shape, flat_list = cls._handle_ndarray_creation_inputs(iterable, shape, **kwargs) + shape = Tuple(*map(_sympify, shape)) + cls._check_special_bounds(flat_list, shape) + flat_list = flatten(flat_list) + flat_list = Tuple(*flat_list) + self = Basic.__new__(cls, flat_list, shape, **kwargs) + self._shape = shape + self._array = list(flat_list) + self._rank = len(shape) + self._loop_size = functools.reduce(lambda x,y: x*y, shape, 1) + return self + + def __setitem__(self, index, value): + raise TypeError('immutable N-dim array') + + def as_mutable(self): + return MutableDenseNDimArray(self) + + def _eval_simplify(self, **kwargs): + from sympy.simplify.simplify import simplify + return self.applyfunc(simplify) + +class MutableDenseNDimArray(DenseNDimArray, MutableNDimArray): + + def __new__(cls, iterable=None, shape=None, **kwargs): + return cls._new(iterable, shape, **kwargs) + + @classmethod + def _new(cls, iterable, shape, **kwargs): + shape, flat_list = cls._handle_ndarray_creation_inputs(iterable, shape, **kwargs) + flat_list = flatten(flat_list) + self = object.__new__(cls) + self._shape = shape + self._array = list(flat_list) + self._rank = len(shape) + self._loop_size = functools.reduce(lambda x,y: x*y, shape) if shape else len(flat_list) + return self + + def __setitem__(self, index, value): + """Allows to set items to MutableDenseNDimArray. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray.zeros(2, 2) + >>> a[0,0] = 1 + >>> a[1,1] = 1 + >>> a + [[1, 0], [0, 1]] + + """ + if isinstance(index, tuple) and any(isinstance(i, slice) for i in index): + value, eindices, slice_offsets = self._get_slice_data_for_array_assignment(index, value) + for i in eindices: + other_i = [ind - j for ind, j in zip(i, slice_offsets) if j is not None] + self._array[self._parse_index(i)] = value[other_i] + else: + index = self._parse_index(index) + self._setter_iterable_check(value) + value = _sympify(value) + self._array[index] = value + + def as_immutable(self): + return ImmutableDenseNDimArray(self) + + @property + def free_symbols(self): + return {i for j in self._array for i in j.free_symbols} diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..f1658241782cdf0e38a30c43a6d67f9811297f4c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/__init__.py @@ -0,0 +1,178 @@ +r""" +Array expressions are expressions representing N-dimensional arrays, without +evaluating them. These expressions represent in a certain way abstract syntax +trees of operations on N-dimensional arrays. + +Every N-dimensional array operator has a corresponding array expression object. + +Table of correspondences: + +=============================== ============================= + Array operator Array expression operator +=============================== ============================= + tensorproduct ArrayTensorProduct + tensorcontraction ArrayContraction + tensordiagonal ArrayDiagonal + permutedims PermuteDims +=============================== ============================= + +Examples +======== + +``ArraySymbol`` objects are the N-dimensional equivalent of ``MatrixSymbol`` +objects in the matrix module: + +>>> from sympy.tensor.array.expressions import ArraySymbol +>>> from sympy.abc import i, j, k +>>> A = ArraySymbol("A", (3, 2, 4)) +>>> A.shape +(3, 2, 4) +>>> A[i, j, k] +A[i, j, k] +>>> A.as_explicit() +[[[A[0, 0, 0], A[0, 0, 1], A[0, 0, 2], A[0, 0, 3]], + [A[0, 1, 0], A[0, 1, 1], A[0, 1, 2], A[0, 1, 3]]], + [[A[1, 0, 0], A[1, 0, 1], A[1, 0, 2], A[1, 0, 3]], + [A[1, 1, 0], A[1, 1, 1], A[1, 1, 2], A[1, 1, 3]]], + [[A[2, 0, 0], A[2, 0, 1], A[2, 0, 2], A[2, 0, 3]], + [A[2, 1, 0], A[2, 1, 1], A[2, 1, 2], A[2, 1, 3]]]] + +Component-explicit arrays can be added inside array expressions: + +>>> from sympy import Array +>>> from sympy import tensorproduct +>>> from sympy.tensor.array.expressions import ArrayTensorProduct +>>> a = Array([1, 2, 3]) +>>> b = Array([i, j, k]) +>>> expr = ArrayTensorProduct(a, b, b) +>>> expr +ArrayTensorProduct([1, 2, 3], [i, j, k], [i, j, k]) +>>> expr.as_explicit() == tensorproduct(a, b, b) +True + +Constructing array expressions from index-explicit forms +-------------------------------------------------------- + +Array expressions are index-implicit. This means they do not use any indices to +represent array operations. The function ``convert_indexed_to_array( ... )`` +may be used to convert index-explicit expressions to array expressions. +It takes as input two parameters: the index-explicit expression and the order +of the indices: + +>>> from sympy.tensor.array.expressions import convert_indexed_to_array +>>> from sympy import Sum +>>> A = ArraySymbol("A", (3, 3)) +>>> B = ArraySymbol("B", (3, 3)) +>>> convert_indexed_to_array(A[i, j], [i, j]) +A +>>> convert_indexed_to_array(A[i, j], [j, i]) +PermuteDims(A, (0 1)) +>>> convert_indexed_to_array(A[i, j] + B[j, i], [i, j]) +ArrayAdd(A, PermuteDims(B, (0 1))) +>>> convert_indexed_to_array(Sum(A[i, j]*B[j, k], (j, 0, 2)), [i, k]) +ArrayContraction(ArrayTensorProduct(A, B), (1, 2)) + +The diagonal of a matrix in the array expression form: + +>>> convert_indexed_to_array(A[i, i], [i]) +ArrayDiagonal(A, (0, 1)) + +The trace of a matrix in the array expression form: + +>>> convert_indexed_to_array(Sum(A[i, i], (i, 0, 2)), [i]) +ArrayContraction(A, (0, 1)) + +Compatibility with matrices +--------------------------- + +Array expressions can be mixed with objects from the matrix module: + +>>> from sympy import MatrixSymbol +>>> from sympy.tensor.array.expressions import ArrayContraction +>>> M = MatrixSymbol("M", 3, 3) +>>> N = MatrixSymbol("N", 3, 3) + +Express the matrix product in the array expression form: + +>>> from sympy.tensor.array.expressions import convert_matrix_to_array +>>> expr = convert_matrix_to_array(M*N) +>>> expr +ArrayContraction(ArrayTensorProduct(M, N), (1, 2)) + +The expression can be converted back to matrix form: + +>>> from sympy.tensor.array.expressions import convert_array_to_matrix +>>> convert_array_to_matrix(expr) +M*N + +Add a second contraction on the remaining axes in order to get the trace of `M \cdot N`: + +>>> expr_tr = ArrayContraction(expr, (0, 1)) +>>> expr_tr +ArrayContraction(ArrayContraction(ArrayTensorProduct(M, N), (1, 2)), (0, 1)) + +Flatten the expression by calling ``.doit()`` and remove the nested array contraction operations: + +>>> expr_tr.doit() +ArrayContraction(ArrayTensorProduct(M, N), (0, 3), (1, 2)) + +Get the explicit form of the array expression: + +>>> expr.as_explicit() +[[M[0, 0]*N[0, 0] + M[0, 1]*N[1, 0] + M[0, 2]*N[2, 0], M[0, 0]*N[0, 1] + M[0, 1]*N[1, 1] + M[0, 2]*N[2, 1], M[0, 0]*N[0, 2] + M[0, 1]*N[1, 2] + M[0, 2]*N[2, 2]], + [M[1, 0]*N[0, 0] + M[1, 1]*N[1, 0] + M[1, 2]*N[2, 0], M[1, 0]*N[0, 1] + M[1, 1]*N[1, 1] + M[1, 2]*N[2, 1], M[1, 0]*N[0, 2] + M[1, 1]*N[1, 2] + M[1, 2]*N[2, 2]], + [M[2, 0]*N[0, 0] + M[2, 1]*N[1, 0] + M[2, 2]*N[2, 0], M[2, 0]*N[0, 1] + M[2, 1]*N[1, 1] + M[2, 2]*N[2, 1], M[2, 0]*N[0, 2] + M[2, 1]*N[1, 2] + M[2, 2]*N[2, 2]]] + +Express the trace of a matrix: + +>>> from sympy import Trace +>>> convert_matrix_to_array(Trace(M)) +ArrayContraction(M, (0, 1)) +>>> convert_matrix_to_array(Trace(M*N)) +ArrayContraction(ArrayTensorProduct(M, N), (0, 3), (1, 2)) + +Express the transposition of a matrix (will be expressed as a permutation of the axes: + +>>> convert_matrix_to_array(M.T) +PermuteDims(M, (0 1)) + +Compute the derivative array expressions: + +>>> from sympy.tensor.array.expressions import array_derive +>>> d = array_derive(M, M) +>>> d +PermuteDims(ArrayTensorProduct(I, I), (3)(1 2)) + +Verify that the derivative corresponds to the form computed with explicit matrices: + +>>> d.as_explicit() +[[[[1, 0, 0], [0, 0, 0], [0, 0, 0]], [[0, 1, 0], [0, 0, 0], [0, 0, 0]], [[0, 0, 1], [0, 0, 0], [0, 0, 0]]], [[[0, 0, 0], [1, 0, 0], [0, 0, 0]], [[0, 0, 0], [0, 1, 0], [0, 0, 0]], [[0, 0, 0], [0, 0, 1], [0, 0, 0]]], [[[0, 0, 0], [0, 0, 0], [1, 0, 0]], [[0, 0, 0], [0, 0, 0], [0, 1, 0]], [[0, 0, 0], [0, 0, 0], [0, 0, 1]]]] +>>> Me = M.as_explicit() +>>> Me.diff(Me) +[[[[1, 0, 0], [0, 0, 0], [0, 0, 0]], [[0, 1, 0], [0, 0, 0], [0, 0, 0]], [[0, 0, 1], [0, 0, 0], [0, 0, 0]]], [[[0, 0, 0], [1, 0, 0], [0, 0, 0]], [[0, 0, 0], [0, 1, 0], [0, 0, 0]], [[0, 0, 0], [0, 0, 1], [0, 0, 0]]], [[[0, 0, 0], [0, 0, 0], [1, 0, 0]], [[0, 0, 0], [0, 0, 0], [0, 1, 0]], [[0, 0, 0], [0, 0, 0], [0, 0, 1]]]] + +""" + +__all__ = [ + "ArraySymbol", "ArrayElement", "ZeroArray", "OneArray", + "ArrayTensorProduct", + "ArrayContraction", + "ArrayDiagonal", + "PermuteDims", + "ArrayAdd", + "ArrayElementwiseApplyFunc", + "Reshape", + "convert_array_to_matrix", + "convert_matrix_to_array", + "convert_array_to_indexed", + "convert_indexed_to_array", + "array_derive", +] + +from sympy.tensor.array.expressions.array_expressions import ArrayTensorProduct, ArrayAdd, PermuteDims, ArrayDiagonal, \ + ArrayContraction, Reshape, ArraySymbol, ArrayElement, ZeroArray, OneArray, ArrayElementwiseApplyFunc +from sympy.tensor.array.expressions.arrayexpr_derivatives import array_derive +from sympy.tensor.array.expressions.from_array_to_indexed import convert_array_to_indexed +from sympy.tensor.array.expressions.from_array_to_matrix import convert_array_to_matrix +from sympy.tensor.array.expressions.from_indexed_to_array import convert_indexed_to_array +from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/array_expressions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/array_expressions.py new file mode 100644 index 0000000000000000000000000000000000000000..f062e3de4c24987d62ba0b3a19fe474fb4687940 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/array_expressions.py @@ -0,0 +1,1969 @@ +from __future__ import annotations +import collections.abc +import operator +from collections import defaultdict, Counter +from functools import reduce +import itertools +from itertools import accumulate + +import typing + +from sympy.core.numbers import Integer +from sympy.core.relational import Equality +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.core.basic import Basic +from sympy.core.containers import Tuple +from sympy.core.expr import Expr +from sympy.core.function import (Function, Lambda) +from sympy.core.mul import Mul +from sympy.core.singleton import S +from sympy.core.sorting import default_sort_key +from sympy.core.symbol import (Dummy, Symbol) +from sympy.matrices.matrixbase import MatrixBase +from sympy.matrices.expressions.diagonal import diagonalize_vector +from sympy.matrices.expressions.matexpr import MatrixExpr +from sympy.matrices.expressions.special import ZeroMatrix +from sympy.tensor.array.arrayop import (permutedims, tensorcontraction, tensordiagonal, tensorproduct) +from sympy.tensor.array.dense_ndim_array import ImmutableDenseNDimArray +from sympy.tensor.array.ndim_array import NDimArray +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.tensor.array.expressions.utils import _apply_recursively_over_nested_lists, _sort_contraction_indices, \ + _get_mapping_from_subranks, _build_push_indices_up_func_transformation, _get_contraction_links, \ + _build_push_indices_down_func_transformation +from sympy.combinatorics import Permutation +from sympy.combinatorics.permutations import _af_invert +from sympy.core.sympify import _sympify + + +class _ArrayExpr(Expr): + shape: tuple[Expr, ...] + + def __getitem__(self, item): + if not isinstance(item, collections.abc.Iterable): + item = (item,) + ArrayElement._check_shape(self, item) + return self._get(item) + + def _get(self, item): + return _get_array_element_or_slice(self, item) + + +class ArraySymbol(_ArrayExpr): + """ + Symbol representing an array expression + """ + + _iterable = False + + def __new__(cls, symbol, shape: typing.Iterable) -> "ArraySymbol": + if isinstance(symbol, str): + symbol = Symbol(symbol) + # symbol = _sympify(symbol) + shape = Tuple(*map(_sympify, shape)) + obj = Expr.__new__(cls, symbol, shape) + return obj + + @property + def name(self): + return self._args[0] + + @property + def shape(self): + return self._args[1] + + def as_explicit(self): + if not all(i.is_Integer for i in self.shape): + raise ValueError("cannot express explicit array with symbolic shape") + data = [self[i] for i in itertools.product(*[range(j) for j in self.shape])] + return ImmutableDenseNDimArray(data).reshape(*self.shape) + + +class ArrayElement(Expr): + """ + An element of an array. + """ + + _diff_wrt = True + is_symbol = True + is_commutative = True + + def __new__(cls, name, indices): + if isinstance(name, str): + name = Symbol(name) + name = _sympify(name) + if not isinstance(indices, collections.abc.Iterable): + indices = (indices,) + indices = _sympify(tuple(indices)) + cls._check_shape(name, indices) + obj = Expr.__new__(cls, name, indices) + return obj + + @classmethod + def _check_shape(cls, name, indices): + indices = tuple(indices) + if hasattr(name, "shape"): + index_error = IndexError("number of indices does not match shape of the array") + if len(indices) != len(name.shape): + raise index_error + if any((i >= s) == True for i, s in zip(indices, name.shape)): + raise ValueError("shape is out of bounds") + if any((i < 0) == True for i in indices): + raise ValueError("shape contains negative values") + + @property + def name(self): + return self._args[0] + + @property + def indices(self): + return self._args[1] + + def _eval_derivative(self, s): + if not isinstance(s, ArrayElement): + return S.Zero + + if s == self: + return S.One + + if s.name != self.name: + return S.Zero + + return Mul.fromiter(KroneckerDelta(i, j) for i, j in zip(self.indices, s.indices)) + + +class ZeroArray(_ArrayExpr): + """ + Symbolic array of zeros. Equivalent to ``ZeroMatrix`` for matrices. + """ + + def __new__(cls, *shape): + if len(shape) == 0: + return S.Zero + shape = map(_sympify, shape) + obj = Expr.__new__(cls, *shape) + return obj + + @property + def shape(self): + return self._args + + def as_explicit(self): + if not all(i.is_Integer for i in self.shape): + raise ValueError("Cannot return explicit form for symbolic shape.") + return ImmutableDenseNDimArray.zeros(*self.shape) + + def _get(self, item): + return S.Zero + + +class OneArray(_ArrayExpr): + """ + Symbolic array of ones. + """ + + def __new__(cls, *shape): + if len(shape) == 0: + return S.One + shape = map(_sympify, shape) + obj = Expr.__new__(cls, *shape) + return obj + + @property + def shape(self): + return self._args + + def as_explicit(self): + if not all(i.is_Integer for i in self.shape): + raise ValueError("Cannot return explicit form for symbolic shape.") + return ImmutableDenseNDimArray([S.One for i in range(reduce(operator.mul, self.shape))]).reshape(*self.shape) + + def _get(self, item): + return S.One + + +class _CodegenArrayAbstract(Basic): + + @property + def subranks(self): + """ + Returns the ranks of the objects in the uppermost tensor product inside + the current object. In case no tensor products are contained, return + the atomic ranks. + + Examples + ======== + + >>> from sympy.tensor.array import tensorproduct, tensorcontraction + >>> from sympy import MatrixSymbol + >>> M = MatrixSymbol("M", 3, 3) + >>> N = MatrixSymbol("N", 3, 3) + >>> P = MatrixSymbol("P", 3, 3) + + Important: do not confuse the rank of the matrix with the rank of an array. + + >>> tp = tensorproduct(M, N, P) + >>> tp.subranks + [2, 2, 2] + + >>> co = tensorcontraction(tp, (1, 2), (3, 4)) + >>> co.subranks + [2, 2, 2] + """ + return self._subranks[:] + + def subrank(self): + """ + The sum of ``subranks``. + """ + return sum(self.subranks) + + @property + def shape(self): + return self._shape + + def doit(self, **hints): + deep = hints.get("deep", True) + if deep: + return self.func(*[arg.doit(**hints) for arg in self.args])._canonicalize() + else: + return self._canonicalize() + +class ArrayTensorProduct(_CodegenArrayAbstract): + r""" + Class to represent the tensor product of array-like objects. + """ + + def __new__(cls, *args, **kwargs): + args = [_sympify(arg) for arg in args] + + canonicalize = kwargs.pop("canonicalize", False) + + ranks = [get_rank(arg) for arg in args] + + obj = Basic.__new__(cls, *args) + obj._subranks = ranks + shapes = [get_shape(i) for i in args] + + if any(i is None for i in shapes): + obj._shape = None + else: + obj._shape = tuple(j for i in shapes for j in i) + if canonicalize: + return obj._canonicalize() + return obj + + def _canonicalize(self): + args = self.args + args = self._flatten(args) + + ranks = [get_rank(arg) for arg in args] + + # Check if there are nested permutation and lift them up: + permutation_cycles = [] + for i, arg in enumerate(args): + if not isinstance(arg, PermuteDims): + continue + permutation_cycles.extend([[k + sum(ranks[:i]) for k in j] for j in arg.permutation.cyclic_form]) + args[i] = arg.expr + if permutation_cycles: + return _permute_dims(_array_tensor_product(*args), Permutation(sum(ranks)-1)*Permutation(permutation_cycles)) + + if len(args) == 1: + return args[0] + + # If any object is a ZeroArray, return a ZeroArray: + if any(isinstance(arg, (ZeroArray, ZeroMatrix)) for arg in args): + shapes = reduce(operator.add, [get_shape(i) for i in args], ()) + return ZeroArray(*shapes) + + # If there are contraction objects inside, transform the whole + # expression into `ArrayContraction`: + contractions = {i: arg for i, arg in enumerate(args) if isinstance(arg, ArrayContraction)} + if contractions: + ranks = [_get_subrank(arg) if isinstance(arg, ArrayContraction) else get_rank(arg) for arg in args] + cumulative_ranks = list(accumulate([0] + ranks))[:-1] + tp = _array_tensor_product(*[arg.expr if isinstance(arg, ArrayContraction) else arg for arg in args]) + contraction_indices = [tuple(cumulative_ranks[i] + k for k in j) for i, arg in contractions.items() for j in arg.contraction_indices] + return _array_contraction(tp, *contraction_indices) + + diagonals = {i: arg for i, arg in enumerate(args) if isinstance(arg, ArrayDiagonal)} + if diagonals: + inverse_permutation = [] + last_perm = [] + ranks = [get_rank(arg) for arg in args] + cumulative_ranks = list(accumulate([0] + ranks))[:-1] + for i, arg in enumerate(args): + if isinstance(arg, ArrayDiagonal): + i1 = get_rank(arg) - len(arg.diagonal_indices) + i2 = len(arg.diagonal_indices) + inverse_permutation.extend([cumulative_ranks[i] + j for j in range(i1)]) + last_perm.extend([cumulative_ranks[i] + j for j in range(i1, i1 + i2)]) + else: + inverse_permutation.extend([cumulative_ranks[i] + j for j in range(get_rank(arg))]) + inverse_permutation.extend(last_perm) + tp = _array_tensor_product(*[arg.expr if isinstance(arg, ArrayDiagonal) else arg for arg in args]) + ranks2 = [_get_subrank(arg) if isinstance(arg, ArrayDiagonal) else get_rank(arg) for arg in args] + cumulative_ranks2 = list(accumulate([0] + ranks2))[:-1] + diagonal_indices = [tuple(cumulative_ranks2[i] + k for k in j) for i, arg in diagonals.items() for j in arg.diagonal_indices] + return _permute_dims(_array_diagonal(tp, *diagonal_indices), _af_invert(inverse_permutation)) + + return self.func(*args, canonicalize=False) + + @classmethod + def _flatten(cls, args): + args = [i for arg in args for i in (arg.args if isinstance(arg, cls) else [arg])] + return args + + def as_explicit(self): + return tensorproduct(*[arg.as_explicit() if hasattr(arg, "as_explicit") else arg for arg in self.args]) + + +class ArrayAdd(_CodegenArrayAbstract): + r""" + Class for elementwise array additions. + """ + + def __new__(cls, *args, **kwargs): + args = [_sympify(arg) for arg in args] + ranks = [get_rank(arg) for arg in args] + ranks = list(set(ranks)) + if len(ranks) != 1: + raise ValueError("summing arrays of different ranks") + shapes = [arg.shape for arg in args] + if len({i for i in shapes if i is not None}) > 1: + raise ValueError("mismatching shapes in addition") + + canonicalize = kwargs.pop("canonicalize", False) + + obj = Basic.__new__(cls, *args) + obj._subranks = ranks + if any(i is None for i in shapes): + obj._shape = None + else: + obj._shape = shapes[0] + if canonicalize: + return obj._canonicalize() + return obj + + def _canonicalize(self): + args = self.args + + # Flatten: + args = self._flatten_args(args) + + shapes = [get_shape(arg) for arg in args] + args = [arg for arg in args if not isinstance(arg, (ZeroArray, ZeroMatrix))] + if len(args) == 0: + if any(i for i in shapes if i is None): + raise NotImplementedError("cannot handle addition of ZeroMatrix/ZeroArray and undefined shape object") + return ZeroArray(*shapes[0]) + elif len(args) == 1: + return args[0] + return self.func(*args, canonicalize=False) + + @classmethod + def _flatten_args(cls, args): + new_args = [] + for arg in args: + if isinstance(arg, ArrayAdd): + new_args.extend(arg.args) + else: + new_args.append(arg) + return new_args + + def as_explicit(self): + return reduce( + operator.add, + [arg.as_explicit() if hasattr(arg, "as_explicit") else arg for arg in self.args]) + + +class PermuteDims(_CodegenArrayAbstract): + r""" + Class to represent permutation of axes of arrays. + + Examples + ======== + + >>> from sympy.tensor.array import permutedims + >>> from sympy import MatrixSymbol + >>> M = MatrixSymbol("M", 3, 3) + >>> cg = permutedims(M, [1, 0]) + + The object ``cg`` represents the transposition of ``M``, as the permutation + ``[1, 0]`` will act on its indices by switching them: + + `M_{ij} \Rightarrow M_{ji}` + + This is evident when transforming back to matrix form: + + >>> from sympy.tensor.array.expressions.from_array_to_matrix import convert_array_to_matrix + >>> convert_array_to_matrix(cg) + M.T + + >>> N = MatrixSymbol("N", 3, 2) + >>> cg = permutedims(N, [1, 0]) + >>> cg.shape + (2, 3) + + There are optional parameters that can be used as alternative to the permutation: + + >>> from sympy.tensor.array.expressions import ArraySymbol, PermuteDims + >>> M = ArraySymbol("M", (1, 2, 3, 4, 5)) + >>> expr = PermuteDims(M, index_order_old="ijklm", index_order_new="kijml") + >>> expr + PermuteDims(M, (0 2 1)(3 4)) + >>> expr.shape + (3, 1, 2, 5, 4) + + Permutations of tensor products are simplified in order to achieve a + standard form: + + >>> from sympy.tensor.array import tensorproduct + >>> M = MatrixSymbol("M", 4, 5) + >>> tp = tensorproduct(M, N) + >>> tp.shape + (4, 5, 3, 2) + >>> perm1 = permutedims(tp, [2, 3, 1, 0]) + + The args ``(M, N)`` have been sorted and the permutation has been + simplified, the expression is equivalent: + + >>> perm1.expr.args + (N, M) + >>> perm1.shape + (3, 2, 5, 4) + >>> perm1.permutation + (2 3) + + The permutation in its array form has been simplified from + ``[2, 3, 1, 0]`` to ``[0, 1, 3, 2]``, as the arguments of the tensor + product `M` and `N` have been switched: + + >>> perm1.permutation.array_form + [0, 1, 3, 2] + + We can nest a second permutation: + + >>> perm2 = permutedims(perm1, [1, 0, 2, 3]) + >>> perm2.shape + (2, 3, 5, 4) + >>> perm2.permutation.array_form + [1, 0, 3, 2] + """ + + def __new__(cls, expr, permutation=None, index_order_old=None, index_order_new=None, **kwargs): + from sympy.combinatorics import Permutation + expr = _sympify(expr) + expr_rank = get_rank(expr) + permutation = cls._get_permutation_from_arguments(permutation, index_order_old, index_order_new, expr_rank) + permutation = Permutation(permutation) + permutation_size = permutation.size + if permutation_size != expr_rank: + raise ValueError("Permutation size must be the length of the shape of expr") + + canonicalize = kwargs.pop("canonicalize", False) + + obj = Basic.__new__(cls, expr, permutation) + obj._subranks = [get_rank(expr)] + shape = get_shape(expr) + if shape is None: + obj._shape = None + else: + obj._shape = tuple(shape[permutation(i)] for i in range(len(shape))) + if canonicalize: + return obj._canonicalize() + return obj + + def _canonicalize(self): + expr = self.expr + permutation = self.permutation + if isinstance(expr, PermuteDims): + subexpr = expr.expr + subperm = expr.permutation + permutation = permutation * subperm + expr = subexpr + if isinstance(expr, ArrayContraction): + expr, permutation = self._PermuteDims_denestarg_ArrayContraction(expr, permutation) + if isinstance(expr, ArrayTensorProduct): + expr, permutation = self._PermuteDims_denestarg_ArrayTensorProduct(expr, permutation) + if isinstance(expr, (ZeroArray, ZeroMatrix)): + return ZeroArray(*[expr.shape[i] for i in permutation.array_form]) + plist = permutation.array_form + if plist == sorted(plist): + return expr + return self.func(expr, permutation, canonicalize=False) + + @property + def expr(self): + return self.args[0] + + @property + def permutation(self): + return self.args[1] + + @classmethod + def _PermuteDims_denestarg_ArrayTensorProduct(cls, expr, permutation): + # Get the permutation in its image-form: + perm_image_form = _af_invert(permutation.array_form) + args = list(expr.args) + # Starting index global position for every arg: + cumul = list(accumulate([0] + expr.subranks)) + # Split `perm_image_form` into a list of list corresponding to the indices + # of every argument: + perm_image_form_in_components = [perm_image_form[cumul[i]:cumul[i+1]] for i in range(len(args))] + # Create an index, target-position-key array: + ps = [(i, sorted(comp)) for i, comp in enumerate(perm_image_form_in_components)] + # Sort the array according to the target-position-key: + # In this way, we define a canonical way to sort the arguments according + # to the permutation. + ps.sort(key=lambda x: x[1]) + # Read the inverse-permutation (i.e. image-form) of the args: + perm_args_image_form = [i[0] for i in ps] + # Apply the args-permutation to the `args`: + args_sorted = [args[i] for i in perm_args_image_form] + # Apply the args-permutation to the array-form of the permutation of the axes (of `expr`): + perm_image_form_sorted_args = [perm_image_form_in_components[i] for i in perm_args_image_form] + new_permutation = Permutation(_af_invert([j for i in perm_image_form_sorted_args for j in i])) + return _array_tensor_product(*args_sorted), new_permutation + + @classmethod + def _PermuteDims_denestarg_ArrayContraction(cls, expr, permutation): + if not isinstance(expr, ArrayContraction): + return expr, permutation + if not isinstance(expr.expr, ArrayTensorProduct): + return expr, permutation + args = expr.expr.args + subranks = [get_rank(arg) for arg in expr.expr.args] + + contraction_indices = expr.contraction_indices + contraction_indices_flat = [j for i in contraction_indices for j in i] + cumul = list(accumulate([0] + subranks)) + + # Spread the permutation in its array form across the args in the corresponding + # tensor-product arguments with free indices: + permutation_array_blocks_up = [] + image_form = _af_invert(permutation.array_form) + counter = 0 + for i in range(len(subranks)): + current = [] + for j in range(cumul[i], cumul[i+1]): + if j in contraction_indices_flat: + continue + current.append(image_form[counter]) + counter += 1 + permutation_array_blocks_up.append(current) + + # Get the map of axis repositioning for every argument of tensor-product: + index_blocks = [list(range(cumul[i], cumul[i+1])) for i, e in enumerate(expr.subranks)] + index_blocks_up = expr._push_indices_up(expr.contraction_indices, index_blocks) + inverse_permutation = permutation**(-1) + index_blocks_up_permuted = [[inverse_permutation(j) for j in i if j is not None] for i in index_blocks_up] + + # Sorting key is a list of tuple, first element is the index of `args`, second element of + # the tuple is the sorting key to sort `args` of the tensor product: + sorting_keys = list(enumerate(index_blocks_up_permuted)) + sorting_keys.sort(key=lambda x: x[1]) + + # Now we can get the permutation acting on the args in its image-form: + new_perm_image_form = [i[0] for i in sorting_keys] + # Apply the args-level permutation to various elements: + new_index_blocks = [index_blocks[i] for i in new_perm_image_form] + new_index_perm_array_form = _af_invert([j for i in new_index_blocks for j in i]) + new_args = [args[i] for i in new_perm_image_form] + new_contraction_indices = [tuple(new_index_perm_array_form[j] for j in i) for i in contraction_indices] + new_expr = _array_contraction(_array_tensor_product(*new_args), *new_contraction_indices) + new_permutation = Permutation(_af_invert([j for i in [permutation_array_blocks_up[k] for k in new_perm_image_form] for j in i])) + return new_expr, new_permutation + + @classmethod + def _check_permutation_mapping(cls, expr, permutation): + subranks = expr.subranks + index2arg = [i for i, arg in enumerate(expr.args) for j in range(expr.subranks[i])] + permuted_indices = [permutation(i) for i in range(expr.subrank())] + new_args = list(expr.args) + arg_candidate_index = index2arg[permuted_indices[0]] + current_indices = [] + new_permutation = [] + inserted_arg_cand_indices = set() + for i, idx in enumerate(permuted_indices): + if index2arg[idx] != arg_candidate_index: + new_permutation.extend(current_indices) + current_indices = [] + arg_candidate_index = index2arg[idx] + current_indices.append(idx) + arg_candidate_rank = subranks[arg_candidate_index] + if len(current_indices) == arg_candidate_rank: + new_permutation.extend(sorted(current_indices)) + local_current_indices = [j - min(current_indices) for j in current_indices] + i1 = index2arg[i] + new_args[i1] = _permute_dims(new_args[i1], Permutation(local_current_indices)) + inserted_arg_cand_indices.add(arg_candidate_index) + current_indices = [] + new_permutation.extend(current_indices) + + # TODO: swap args positions in order to simplify the expression: + # TODO: this should be in a function + args_positions = list(range(len(new_args))) + # Get possible shifts: + maps = {} + cumulative_subranks = [0] + list(accumulate(subranks)) + for i in range(len(subranks)): + s = {index2arg[new_permutation[j]] for j in range(cumulative_subranks[i], cumulative_subranks[i+1])} + if len(s) != 1: + continue + elem = next(iter(s)) + if i != elem: + maps[i] = elem + + # Find cycles in the map: + lines = [] + current_line = [] + while maps: + if len(current_line) == 0: + k, v = maps.popitem() + current_line.append(k) + else: + k = current_line[-1] + if k not in maps: + current_line = [] + continue + v = maps.pop(k) + if v in current_line: + lines.append(current_line) + current_line = [] + continue + current_line.append(v) + for line in lines: + for i, e in enumerate(line): + args_positions[line[(i + 1) % len(line)]] = e + + # TODO: function in order to permute the args: + permutation_blocks = [[new_permutation[cumulative_subranks[i] + j] for j in range(e)] for i, e in enumerate(subranks)] + new_args = [new_args[i] for i in args_positions] + new_permutation_blocks = [permutation_blocks[i] for i in args_positions] + new_permutation2 = [j for i in new_permutation_blocks for j in i] + return _array_tensor_product(*new_args), Permutation(new_permutation2) # **(-1) + + @classmethod + def _check_if_there_are_closed_cycles(cls, expr, permutation): + args = list(expr.args) + subranks = expr.subranks + cyclic_form = permutation.cyclic_form + cumulative_subranks = [0] + list(accumulate(subranks)) + cyclic_min = [min(i) for i in cyclic_form] + cyclic_max = [max(i) for i in cyclic_form] + cyclic_keep = [] + for i, cycle in enumerate(cyclic_form): + flag = True + for j in range(len(cumulative_subranks) - 1): + if cyclic_min[i] >= cumulative_subranks[j] and cyclic_max[i] < cumulative_subranks[j+1]: + # Found a sinkable cycle. + args[j] = _permute_dims(args[j], Permutation([[k - cumulative_subranks[j] for k in cycle]])) + flag = False + break + if flag: + cyclic_keep.append(cycle) + return _array_tensor_product(*args), Permutation(cyclic_keep, size=permutation.size) + + def nest_permutation(self): + r""" + DEPRECATED. + """ + ret = self._nest_permutation(self.expr, self.permutation) + if ret is None: + return self + return ret + + @classmethod + def _nest_permutation(cls, expr, permutation): + if isinstance(expr, ArrayTensorProduct): + return _permute_dims(*cls._check_if_there_are_closed_cycles(expr, permutation)) + elif isinstance(expr, ArrayContraction): + # Invert tree hierarchy: put the contraction above. + cycles = permutation.cyclic_form + newcycles = ArrayContraction._convert_outer_indices_to_inner_indices(expr, *cycles) + newpermutation = Permutation(newcycles) + new_contr_indices = [tuple(newpermutation(j) for j in i) for i in expr.contraction_indices] + return _array_contraction(PermuteDims(expr.expr, newpermutation), *new_contr_indices) + elif isinstance(expr, ArrayAdd): + return _array_add(*[PermuteDims(arg, permutation) for arg in expr.args]) + return None + + def as_explicit(self): + expr = self.expr + if hasattr(expr, "as_explicit"): + expr = expr.as_explicit() + return permutedims(expr, self.permutation) + + @classmethod + def _get_permutation_from_arguments(cls, permutation, index_order_old, index_order_new, dim): + if permutation is None: + if index_order_new is None or index_order_old is None: + raise ValueError("Permutation not defined") + return PermuteDims._get_permutation_from_index_orders(index_order_old, index_order_new, dim) + else: + if index_order_new is not None: + raise ValueError("index_order_new cannot be defined with permutation") + if index_order_old is not None: + raise ValueError("index_order_old cannot be defined with permutation") + return permutation + + @classmethod + def _get_permutation_from_index_orders(cls, index_order_old, index_order_new, dim): + if len(set(index_order_new)) != dim: + raise ValueError("wrong number of indices in index_order_new") + if len(set(index_order_old)) != dim: + raise ValueError("wrong number of indices in index_order_old") + if len(set.symmetric_difference(set(index_order_new), set(index_order_old))) > 0: + raise ValueError("index_order_new and index_order_old must have the same indices") + permutation = [index_order_old.index(i) for i in index_order_new] + return permutation + + +class ArrayDiagonal(_CodegenArrayAbstract): + r""" + Class to represent the diagonal operator. + + Explanation + =========== + + In a 2-dimensional array it returns the diagonal, this looks like the + operation: + + `A_{ij} \rightarrow A_{ii}` + + The diagonal over axes 1 and 2 (the second and third) of the tensor product + of two 2-dimensional arrays `A \otimes B` is + + `\Big[ A_{ab} B_{cd} \Big]_{abcd} \rightarrow \Big[ A_{ai} B_{id} \Big]_{adi}` + + In this last example the array expression has been reduced from + 4-dimensional to 3-dimensional. Notice that no contraction has occurred, + rather there is a new index `i` for the diagonal, contraction would have + reduced the array to 2 dimensions. + + Notice that the diagonalized out dimensions are added as new dimensions at + the end of the indices. + """ + + def __new__(cls, expr, *diagonal_indices, **kwargs): + expr = _sympify(expr) + diagonal_indices = [Tuple(*sorted(i)) for i in diagonal_indices] + canonicalize = kwargs.get("canonicalize", False) + + shape = get_shape(expr) + if shape is not None: + cls._validate(expr, *diagonal_indices, **kwargs) + # Get new shape: + positions, shape = cls._get_positions_shape(shape, diagonal_indices) + else: + positions = None + if len(diagonal_indices) == 0: + return expr + obj = Basic.__new__(cls, expr, *diagonal_indices) + obj._positions = positions + obj._subranks = _get_subranks(expr) + obj._shape = shape + if canonicalize: + return obj._canonicalize() + return obj + + def _canonicalize(self): + expr = self.expr + diagonal_indices = self.diagonal_indices + trivial_diags = [i for i in diagonal_indices if len(i) == 1] + if len(trivial_diags) > 0: + trivial_pos = {e[0]: i for i, e in enumerate(diagonal_indices) if len(e) == 1} + diag_pos = {e: i for i, e in enumerate(diagonal_indices) if len(e) > 1} + diagonal_indices_short = [i for i in diagonal_indices if len(i) > 1] + rank1 = get_rank(self) + rank2 = len(diagonal_indices) + rank3 = rank1 - rank2 + inv_permutation = [] + counter1 = 0 + indices_down = ArrayDiagonal._push_indices_down(diagonal_indices_short, list(range(rank1)), get_rank(expr)) + for i in indices_down: + if i in trivial_pos: + inv_permutation.append(rank3 + trivial_pos[i]) + elif isinstance(i, (Integer, int)): + inv_permutation.append(counter1) + counter1 += 1 + else: + inv_permutation.append(rank3 + diag_pos[i]) + permutation = _af_invert(inv_permutation) + if len(diagonal_indices_short) > 0: + return _permute_dims(_array_diagonal(expr, *diagonal_indices_short), permutation) + else: + return _permute_dims(expr, permutation) + if isinstance(expr, ArrayAdd): + return self._ArrayDiagonal_denest_ArrayAdd(expr, *diagonal_indices) + if isinstance(expr, ArrayDiagonal): + return self._ArrayDiagonal_denest_ArrayDiagonal(expr, *diagonal_indices) + if isinstance(expr, PermuteDims): + return self._ArrayDiagonal_denest_PermuteDims(expr, *diagonal_indices) + if isinstance(expr, (ZeroArray, ZeroMatrix)): + positions, shape = self._get_positions_shape(expr.shape, diagonal_indices) + return ZeroArray(*shape) + return self.func(expr, *diagonal_indices, canonicalize=False) + + @staticmethod + def _validate(expr, *diagonal_indices, **kwargs): + # Check that no diagonalization happens on indices with mismatched + # dimensions: + shape = get_shape(expr) + for i in diagonal_indices: + if any(j >= len(shape) for j in i): + raise ValueError("index is larger than expression shape") + if len({shape[j] for j in i}) != 1: + raise ValueError("diagonalizing indices of different dimensions") + if not kwargs.get("allow_trivial_diags", False) and len(i) <= 1: + raise ValueError("need at least two axes to diagonalize") + if len(set(i)) != len(i): + raise ValueError("axis index cannot be repeated") + + @staticmethod + def _remove_trivial_dimensions(shape, *diagonal_indices): + return [tuple(j for j in i) for i in diagonal_indices if shape[i[0]] != 1] + + @property + def expr(self): + return self.args[0] + + @property + def diagonal_indices(self): + return self.args[1:] + + @staticmethod + def _flatten(expr, *outer_diagonal_indices): + inner_diagonal_indices = expr.diagonal_indices + all_inner = [j for i in inner_diagonal_indices for j in i] + all_inner.sort() + # TODO: add API for total rank and cumulative rank: + total_rank = _get_subrank(expr) + inner_rank = len(all_inner) + outer_rank = total_rank - inner_rank + shifts = [0 for i in range(outer_rank)] + counter = 0 + pointer = 0 + for i in range(outer_rank): + while pointer < inner_rank and counter >= all_inner[pointer]: + counter += 1 + pointer += 1 + shifts[i] += pointer + counter += 1 + outer_diagonal_indices = tuple(tuple(shifts[j] + j for j in i) for i in outer_diagonal_indices) + diagonal_indices = inner_diagonal_indices + outer_diagonal_indices + return _array_diagonal(expr.expr, *diagonal_indices) + + @classmethod + def _ArrayDiagonal_denest_ArrayAdd(cls, expr, *diagonal_indices): + return _array_add(*[_array_diagonal(arg, *diagonal_indices) for arg in expr.args]) + + @classmethod + def _ArrayDiagonal_denest_ArrayDiagonal(cls, expr, *diagonal_indices): + return cls._flatten(expr, *diagonal_indices) + + @classmethod + def _ArrayDiagonal_denest_PermuteDims(cls, expr: PermuteDims, *diagonal_indices): + back_diagonal_indices = [[expr.permutation(j) for j in i] for i in diagonal_indices] + nondiag = [i for i in range(get_rank(expr)) if not any(i in j for j in diagonal_indices)] + back_nondiag = [expr.permutation(i) for i in nondiag] + remap = {e: i for i, e in enumerate(sorted(back_nondiag))} + new_permutation1 = [remap[i] for i in back_nondiag] + shift = len(new_permutation1) + diag_block_perm = [i + shift for i in range(len(back_diagonal_indices))] + new_permutation = new_permutation1 + diag_block_perm + return _permute_dims( + _array_diagonal( + expr.expr, + *back_diagonal_indices + ), + new_permutation + ) + + def _push_indices_down_nonstatic(self, indices): + transform = lambda x: self._positions[x] if x < len(self._positions) else None + return _apply_recursively_over_nested_lists(transform, indices) + + def _push_indices_up_nonstatic(self, indices): + + def transform(x): + for i, e in enumerate(self._positions): + if (isinstance(e, int) and x == e) or (isinstance(e, tuple) and x in e): + return i + + return _apply_recursively_over_nested_lists(transform, indices) + + @classmethod + def _push_indices_down(cls, diagonal_indices, indices, rank): + positions, shape = cls._get_positions_shape(range(rank), diagonal_indices) + transform = lambda x: positions[x] if x < len(positions) else None + return _apply_recursively_over_nested_lists(transform, indices) + + @classmethod + def _push_indices_up(cls, diagonal_indices, indices, rank): + positions, shape = cls._get_positions_shape(range(rank), diagonal_indices) + + def transform(x): + for i, e in enumerate(positions): + if (isinstance(e, int) and x == e) or (isinstance(e, (tuple, Tuple)) and (x in e)): + return i + + return _apply_recursively_over_nested_lists(transform, indices) + + @classmethod + def _get_positions_shape(cls, shape, diagonal_indices): + data1 = tuple((i, shp) for i, shp in enumerate(shape) if not any(i in j for j in diagonal_indices)) + pos1, shp1 = zip(*data1) if data1 else ((), ()) + data2 = tuple((i, shape[i[0]]) for i in diagonal_indices) + pos2, shp2 = zip(*data2) if data2 else ((), ()) + positions = pos1 + pos2 + shape = shp1 + shp2 + return positions, shape + + def as_explicit(self): + expr = self.expr + if hasattr(expr, "as_explicit"): + expr = expr.as_explicit() + return tensordiagonal(expr, *self.diagonal_indices) + + +class ArrayElementwiseApplyFunc(_CodegenArrayAbstract): + + def __new__(cls, function, element): + + if not isinstance(function, Lambda): + d = Dummy('d') + function = Lambda(d, function(d)) + + obj = _CodegenArrayAbstract.__new__(cls, function, element) + obj._subranks = _get_subranks(element) + return obj + + @property + def function(self): + return self.args[0] + + @property + def expr(self): + return self.args[1] + + @property + def shape(self): + return self.expr.shape + + def _get_function_fdiff(self): + d = Dummy("d") + function = self.function(d) + fdiff = function.diff(d) + if isinstance(fdiff, Function): + fdiff = type(fdiff) + else: + fdiff = Lambda(d, fdiff) + return fdiff + + def as_explicit(self): + expr = self.expr + if hasattr(expr, "as_explicit"): + expr = expr.as_explicit() + return expr.applyfunc(self.function) + + +class ArrayContraction(_CodegenArrayAbstract): + r""" + This class is meant to represent contractions of arrays in a form easily + processable by the code printers. + """ + + def __new__(cls, expr, *contraction_indices, **kwargs): + contraction_indices = _sort_contraction_indices(contraction_indices) + expr = _sympify(expr) + + canonicalize = kwargs.get("canonicalize", False) + + obj = Basic.__new__(cls, expr, *contraction_indices) + obj._subranks = _get_subranks(expr) + obj._mapping = _get_mapping_from_subranks(obj._subranks) + + free_indices_to_position = {i: i for i in range(sum(obj._subranks)) if all(i not in cind for cind in contraction_indices)} + obj._free_indices_to_position = free_indices_to_position + + shape = get_shape(expr) + cls._validate(expr, *contraction_indices) + if shape: + shape = tuple(shp for i, shp in enumerate(shape) if not any(i in j for j in contraction_indices)) + obj._shape = shape + if canonicalize: + return obj._canonicalize() + return obj + + def _canonicalize(self): + expr = self.expr + contraction_indices = self.contraction_indices + + if len(contraction_indices) == 0: + return expr + + if isinstance(expr, ArrayContraction): + return self._ArrayContraction_denest_ArrayContraction(expr, *contraction_indices) + + if isinstance(expr, (ZeroArray, ZeroMatrix)): + return self._ArrayContraction_denest_ZeroArray(expr, *contraction_indices) + + if isinstance(expr, PermuteDims): + return self._ArrayContraction_denest_PermuteDims(expr, *contraction_indices) + + if isinstance(expr, ArrayTensorProduct): + expr, contraction_indices = self._sort_fully_contracted_args(expr, contraction_indices) + expr, contraction_indices = self._lower_contraction_to_addends(expr, contraction_indices) + if len(contraction_indices) == 0: + return expr + + if isinstance(expr, ArrayDiagonal): + return self._ArrayContraction_denest_ArrayDiagonal(expr, *contraction_indices) + + if isinstance(expr, ArrayAdd): + return self._ArrayContraction_denest_ArrayAdd(expr, *contraction_indices) + + # Check single index contractions on 1-dimensional axes: + contraction_indices = [i for i in contraction_indices if len(i) > 1 or get_shape(expr)[i[0]] != 1] + if len(contraction_indices) == 0: + return expr + + return self.func(expr, *contraction_indices, canonicalize=False) + + def __mul__(self, other): + if other == 1: + return self + else: + raise NotImplementedError("Product of N-dim arrays is not uniquely defined. Use another method.") + + def __rmul__(self, other): + if other == 1: + return self + else: + raise NotImplementedError("Product of N-dim arrays is not uniquely defined. Use another method.") + + @staticmethod + def _validate(expr, *contraction_indices): + shape = get_shape(expr) + if shape is None: + return + + # Check that no contraction happens when the shape is mismatched: + for i in contraction_indices: + if len({shape[j] for j in i if shape[j] != -1}) != 1: + raise ValueError("contracting indices of different dimensions") + + @classmethod + def _push_indices_down(cls, contraction_indices, indices): + flattened_contraction_indices = [j for i in contraction_indices for j in i] + flattened_contraction_indices.sort() + transform = _build_push_indices_down_func_transformation(flattened_contraction_indices) + return _apply_recursively_over_nested_lists(transform, indices) + + @classmethod + def _push_indices_up(cls, contraction_indices, indices): + flattened_contraction_indices = [j for i in contraction_indices for j in i] + flattened_contraction_indices.sort() + transform = _build_push_indices_up_func_transformation(flattened_contraction_indices) + return _apply_recursively_over_nested_lists(transform, indices) + + @classmethod + def _lower_contraction_to_addends(cls, expr, contraction_indices): + if isinstance(expr, ArrayAdd): + raise NotImplementedError() + if not isinstance(expr, ArrayTensorProduct): + return expr, contraction_indices + subranks = expr.subranks + cumranks = list(accumulate([0] + subranks)) + contraction_indices_remaining = [] + contraction_indices_args = [[] for i in expr.args] + backshift = set() + for contraction_group in contraction_indices: + for j in range(len(expr.args)): + if not isinstance(expr.args[j], ArrayAdd): + continue + if all(cumranks[j] <= k < cumranks[j+1] for k in contraction_group): + contraction_indices_args[j].append([k - cumranks[j] for k in contraction_group]) + backshift.update(contraction_group) + break + else: + contraction_indices_remaining.append(contraction_group) + if len(contraction_indices_remaining) == len(contraction_indices): + return expr, contraction_indices + total_rank = get_rank(expr) + shifts = list(accumulate([1 if i in backshift else 0 for i in range(total_rank)])) + contraction_indices_remaining = [Tuple.fromiter(j - shifts[j] for j in i) for i in contraction_indices_remaining] + ret = _array_tensor_product(*[ + _array_contraction(arg, *contr) for arg, contr in zip(expr.args, contraction_indices_args) + ]) + return ret, contraction_indices_remaining + + def split_multiple_contractions(self): + """ + Recognize multiple contractions and attempt at rewriting them as paired-contractions. + + This allows some contractions involving more than two indices to be + rewritten as multiple contractions involving two indices, thus allowing + the expression to be rewritten as a matrix multiplication line. + + Examples: + + * `A_ij b_j0 C_jk` ===> `A*DiagMatrix(b)*C` + + Care for: + - matrix being diagonalized (i.e. `A_ii`) + - vectors being diagonalized (i.e. `a_i0`) + + Multiple contractions can be split into matrix multiplications if + not more than two arguments are non-diagonals or non-vectors. + Vectors get diagonalized while diagonal matrices remain diagonal. + The non-diagonal matrices can be at the beginning or at the end + of the final matrix multiplication line. + """ + + editor = _EditArrayContraction(self) + + contraction_indices = self.contraction_indices + + onearray_insert = [] + + for indl, links in enumerate(contraction_indices): + if len(links) <= 2: + continue + + # Check multiple contractions: + # + # Examples: + # + # * `A_ij b_j0 C_jk` ===> `A*DiagMatrix(b)*C \otimes OneArray(1)` with permutation (1 2) + # + # Care for: + # - matrix being diagonalized (i.e. `A_ii`) + # - vectors being diagonalized (i.e. `a_i0`) + + # Multiple contractions can be split into matrix multiplications if + # not more than three arguments are non-diagonals or non-vectors. + # + # Vectors get diagonalized while diagonal matrices remain diagonal. + # The non-diagonal matrices can be at the beginning or at the end + # of the final matrix multiplication line. + + positions = editor.get_mapping_for_index(indl) + + # Also consider the case of diagonal matrices being contracted: + current_dimension = self.expr.shape[links[0]] + + not_vectors = [] + vectors = [] + for arg_ind, rel_ind in positions: + arg = editor.args_with_ind[arg_ind] + mat = arg.element + abs_arg_start, abs_arg_end = editor.get_absolute_range(arg) + other_arg_pos = 1-rel_ind + other_arg_abs = abs_arg_start + other_arg_pos + if ((1 not in mat.shape) or + ((current_dimension == 1) is True and mat.shape != (1, 1)) or + any(other_arg_abs in l for li, l in enumerate(contraction_indices) if li != indl) + ): + not_vectors.append((arg, rel_ind)) + else: + vectors.append((arg, rel_ind)) + if len(not_vectors) > 2: + # If more than two arguments in the multiple contraction are + # non-vectors and non-diagonal matrices, we cannot find a way + # to split this contraction into a matrix multiplication line: + continue + # Three cases to handle: + # - zero non-vectors + # - one non-vector + # - two non-vectors + for v, rel_ind in vectors: + v.element = diagonalize_vector(v.element) + vectors_to_loop = not_vectors[:1] + vectors + not_vectors[1:] + first_not_vector, rel_ind = vectors_to_loop[0] + new_index = first_not_vector.indices[rel_ind] + + for v, rel_ind in vectors_to_loop[1:-1]: + v.indices[rel_ind] = new_index + new_index = editor.get_new_contraction_index() + assert v.indices.index(None) == 1 - rel_ind + v.indices[v.indices.index(None)] = new_index + onearray_insert.append(v) + + last_vec, rel_ind = vectors_to_loop[-1] + last_vec.indices[rel_ind] = new_index + + for v in onearray_insert: + editor.insert_after(v, _ArgE(OneArray(1), [None])) + + return editor.to_array_contraction() + + def flatten_contraction_of_diagonal(self): + if not isinstance(self.expr, ArrayDiagonal): + return self + contraction_down = self.expr._push_indices_down(self.expr.diagonal_indices, self.contraction_indices) + new_contraction_indices = [] + diagonal_indices = self.expr.diagonal_indices[:] + for i in contraction_down: + contraction_group = list(i) + for j in i: + diagonal_with = [k for k in diagonal_indices if j in k] + contraction_group.extend([l for k in diagonal_with for l in k]) + diagonal_indices = [k for k in diagonal_indices if k not in diagonal_with] + new_contraction_indices.append(sorted(set(contraction_group))) + + new_contraction_indices = ArrayDiagonal._push_indices_up(diagonal_indices, new_contraction_indices) + return _array_contraction( + _array_diagonal( + self.expr.expr, + *diagonal_indices + ), + *new_contraction_indices + ) + + @staticmethod + def _get_free_indices_to_position_map(free_indices, contraction_indices): + free_indices_to_position = {} + flattened_contraction_indices = [j for i in contraction_indices for j in i] + counter = 0 + for ind in free_indices: + while counter in flattened_contraction_indices: + counter += 1 + free_indices_to_position[ind] = counter + counter += 1 + return free_indices_to_position + + @staticmethod + def _get_index_shifts(expr): + """ + Get the mapping of indices at the positions before the contraction + occurs. + + Examples + ======== + + >>> from sympy.tensor.array import tensorproduct, tensorcontraction + >>> from sympy import MatrixSymbol + >>> M = MatrixSymbol("M", 3, 3) + >>> N = MatrixSymbol("N", 3, 3) + >>> cg = tensorcontraction(tensorproduct(M, N), [1, 2]) + >>> cg._get_index_shifts(cg) + [0, 2] + + Indeed, ``cg`` after the contraction has two dimensions, 0 and 1. They + need to be shifted by 0 and 2 to get the corresponding positions before + the contraction (that is, 0 and 3). + """ + inner_contraction_indices = expr.contraction_indices + all_inner = [j for i in inner_contraction_indices for j in i] + all_inner.sort() + # TODO: add API for total rank and cumulative rank: + total_rank = _get_subrank(expr) + inner_rank = len(all_inner) + outer_rank = total_rank - inner_rank + shifts = [0 for i in range(outer_rank)] + counter = 0 + pointer = 0 + for i in range(outer_rank): + while pointer < inner_rank and counter >= all_inner[pointer]: + counter += 1 + pointer += 1 + shifts[i] += pointer + counter += 1 + return shifts + + @staticmethod + def _convert_outer_indices_to_inner_indices(expr, *outer_contraction_indices): + shifts = ArrayContraction._get_index_shifts(expr) + outer_contraction_indices = tuple(tuple(shifts[j] + j for j in i) for i in outer_contraction_indices) + return outer_contraction_indices + + @staticmethod + def _flatten(expr, *outer_contraction_indices): + inner_contraction_indices = expr.contraction_indices + outer_contraction_indices = ArrayContraction._convert_outer_indices_to_inner_indices(expr, *outer_contraction_indices) + contraction_indices = inner_contraction_indices + outer_contraction_indices + return _array_contraction(expr.expr, *contraction_indices) + + @classmethod + def _ArrayContraction_denest_ArrayContraction(cls, expr, *contraction_indices): + return cls._flatten(expr, *contraction_indices) + + @classmethod + def _ArrayContraction_denest_ZeroArray(cls, expr, *contraction_indices): + contraction_indices_flat = [j for i in contraction_indices for j in i] + shape = [e for i, e in enumerate(expr.shape) if i not in contraction_indices_flat] + return ZeroArray(*shape) + + @classmethod + def _ArrayContraction_denest_ArrayAdd(cls, expr, *contraction_indices): + return _array_add(*[_array_contraction(i, *contraction_indices) for i in expr.args]) + + @classmethod + def _ArrayContraction_denest_PermuteDims(cls, expr, *contraction_indices): + permutation = expr.permutation + plist = permutation.array_form + new_contraction_indices = [tuple(permutation(j) for j in i) for i in contraction_indices] + new_plist = [i for i in plist if not any(i in j for j in new_contraction_indices)] + new_plist = cls._push_indices_up(new_contraction_indices, new_plist) + return _permute_dims( + _array_contraction(expr.expr, *new_contraction_indices), + Permutation(new_plist) + ) + + @classmethod + def _ArrayContraction_denest_ArrayDiagonal(cls, expr: 'ArrayDiagonal', *contraction_indices): + diagonal_indices = list(expr.diagonal_indices) + down_contraction_indices = expr._push_indices_down(expr.diagonal_indices, contraction_indices, get_rank(expr.expr)) + # Flatten diagonally contracted indices: + down_contraction_indices = [[k for j in i for k in (j if isinstance(j, (tuple, Tuple)) else [j])] for i in down_contraction_indices] + new_contraction_indices = [] + for contr_indgrp in down_contraction_indices: + ind = contr_indgrp[:] + for j, diag_indgrp in enumerate(diagonal_indices): + if diag_indgrp is None: + continue + if any(i in diag_indgrp for i in contr_indgrp): + ind.extend(diag_indgrp) + diagonal_indices[j] = None + new_contraction_indices.append(sorted(set(ind))) + + new_diagonal_indices_down = [i for i in diagonal_indices if i is not None] + new_diagonal_indices = ArrayContraction._push_indices_up(new_contraction_indices, new_diagonal_indices_down) + return _array_diagonal( + _array_contraction(expr.expr, *new_contraction_indices), + *new_diagonal_indices + ) + + @classmethod + def _sort_fully_contracted_args(cls, expr, contraction_indices): + if expr.shape is None: + return expr, contraction_indices + cumul = list(accumulate([0] + expr.subranks)) + index_blocks = [list(range(cumul[i], cumul[i+1])) for i in range(len(expr.args))] + contraction_indices_flat = {j for i in contraction_indices for j in i} + fully_contracted = [all(j in contraction_indices_flat for j in range(cumul[i], cumul[i+1])) for i, arg in enumerate(expr.args)] + new_pos = sorted(range(len(expr.args)), key=lambda x: (0, default_sort_key(expr.args[x])) if fully_contracted[x] else (1,)) + new_args = [expr.args[i] for i in new_pos] + new_index_blocks_flat = [j for i in new_pos for j in index_blocks[i]] + index_permutation_array_form = _af_invert(new_index_blocks_flat) + new_contraction_indices = [tuple(index_permutation_array_form[j] for j in i) for i in contraction_indices] + new_contraction_indices = _sort_contraction_indices(new_contraction_indices) + return _array_tensor_product(*new_args), new_contraction_indices + + def _get_contraction_tuples(self): + r""" + Return tuples containing the argument index and position within the + argument of the index position. + + Examples + ======== + + >>> from sympy import MatrixSymbol + >>> from sympy.abc import N + >>> from sympy.tensor.array import tensorproduct, tensorcontraction + >>> A = MatrixSymbol("A", N, N) + >>> B = MatrixSymbol("B", N, N) + + >>> cg = tensorcontraction(tensorproduct(A, B), (1, 2)) + >>> cg._get_contraction_tuples() + [[(0, 1), (1, 0)]] + + Notes + ===== + + Here the contraction pair `(1, 2)` meaning that the 2nd and 3rd indices + of the tensor product `A\otimes B` are contracted, has been transformed + into `(0, 1)` and `(1, 0)`, identifying the same indices in a different + notation. `(0, 1)` is the second index (1) of the first argument (i.e. + 0 or `A`). `(1, 0)` is the first index (i.e. 0) of the second + argument (i.e. 1 or `B`). + """ + mapping = self._mapping + return [[mapping[j] for j in i] for i in self.contraction_indices] + + @staticmethod + def _contraction_tuples_to_contraction_indices(expr, contraction_tuples): + # TODO: check that `expr` has `.subranks`: + ranks = expr.subranks + cumulative_ranks = [0] + list(accumulate(ranks)) + return [tuple(cumulative_ranks[j]+k for j, k in i) for i in contraction_tuples] + + @property + def free_indices(self): + return self._free_indices[:] + + @property + def free_indices_to_position(self): + return dict(self._free_indices_to_position) + + @property + def expr(self): + return self.args[0] + + @property + def contraction_indices(self): + return self.args[1:] + + def _contraction_indices_to_components(self): + expr = self.expr + if not isinstance(expr, ArrayTensorProduct): + raise NotImplementedError("only for contractions of tensor products") + ranks = expr.subranks + mapping = {} + counter = 0 + for i, rank in enumerate(ranks): + for j in range(rank): + mapping[counter] = (i, j) + counter += 1 + return mapping + + def sort_args_by_name(self): + """ + Sort arguments in the tensor product so that their order is lexicographical. + + Examples + ======== + + >>> from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array + >>> from sympy import MatrixSymbol + >>> from sympy.abc import N + >>> A = MatrixSymbol("A", N, N) + >>> B = MatrixSymbol("B", N, N) + >>> C = MatrixSymbol("C", N, N) + >>> D = MatrixSymbol("D", N, N) + + >>> cg = convert_matrix_to_array(C*D*A*B) + >>> cg + ArrayContraction(ArrayTensorProduct(A, D, C, B), (0, 3), (1, 6), (2, 5)) + >>> cg.sort_args_by_name() + ArrayContraction(ArrayTensorProduct(A, D, B, C), (0, 3), (1, 4), (2, 7)) + """ + expr = self.expr + if not isinstance(expr, ArrayTensorProduct): + return self + args = expr.args + sorted_data = sorted(enumerate(args), key=lambda x: default_sort_key(x[1])) + pos_sorted, args_sorted = zip(*sorted_data) + reordering_map = {i: pos_sorted.index(i) for i, arg in enumerate(args)} + contraction_tuples = self._get_contraction_tuples() + contraction_tuples = [[(reordering_map[j], k) for j, k in i] for i in contraction_tuples] + c_tp = _array_tensor_product(*args_sorted) + new_contr_indices = self._contraction_tuples_to_contraction_indices( + c_tp, + contraction_tuples + ) + return _array_contraction(c_tp, *new_contr_indices) + + def _get_contraction_links(self): + r""" + Returns a dictionary of links between arguments in the tensor product + being contracted. + + See the example for an explanation of the values. + + Examples + ======== + + >>> from sympy import MatrixSymbol + >>> from sympy.abc import N + >>> from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array + >>> A = MatrixSymbol("A", N, N) + >>> B = MatrixSymbol("B", N, N) + >>> C = MatrixSymbol("C", N, N) + >>> D = MatrixSymbol("D", N, N) + + Matrix multiplications are pairwise contractions between neighboring + matrices: + + `A_{ij} B_{jk} C_{kl} D_{lm}` + + >>> cg = convert_matrix_to_array(A*B*C*D) + >>> cg + ArrayContraction(ArrayTensorProduct(B, C, A, D), (0, 5), (1, 2), (3, 6)) + + >>> cg._get_contraction_links() + {0: {0: (2, 1), 1: (1, 0)}, 1: {0: (0, 1), 1: (3, 0)}, 2: {1: (0, 0)}, 3: {0: (1, 1)}} + + This dictionary is interpreted as follows: argument in position 0 (i.e. + matrix `A`) has its second index (i.e. 1) contracted to `(1, 0)`, that + is argument in position 1 (matrix `B`) on the first index slot of `B`, + this is the contraction provided by the index `j` from `A`. + + The argument in position 1 (that is, matrix `B`) has two contractions, + the ones provided by the indices `j` and `k`, respectively the first + and second indices (0 and 1 in the sub-dict). The link `(0, 1)` and + `(2, 0)` respectively. `(0, 1)` is the index slot 1 (the 2nd) of + argument in position 0 (that is, `A_{\ldot j}`), and so on. + """ + args, dlinks = _get_contraction_links([self], self.subranks, *self.contraction_indices) + return dlinks + + def as_explicit(self): + expr = self.expr + if hasattr(expr, "as_explicit"): + expr = expr.as_explicit() + return tensorcontraction(expr, *self.contraction_indices) + + +class Reshape(_CodegenArrayAbstract): + """ + Reshape the dimensions of an array expression. + + Examples + ======== + + >>> from sympy.tensor.array.expressions import ArraySymbol, Reshape + >>> A = ArraySymbol("A", (6,)) + >>> A.shape + (6,) + >>> Reshape(A, (3, 2)).shape + (3, 2) + + Check the component-explicit forms: + + >>> A.as_explicit() + [A[0], A[1], A[2], A[3], A[4], A[5]] + >>> Reshape(A, (3, 2)).as_explicit() + [[A[0], A[1]], [A[2], A[3]], [A[4], A[5]]] + + """ + + def __new__(cls, expr, shape): + expr = _sympify(expr) + if not isinstance(shape, Tuple): + shape = Tuple(*shape) + if Equality(Mul.fromiter(expr.shape), Mul.fromiter(shape)) == False: + raise ValueError("shape mismatch") + obj = Expr.__new__(cls, expr, shape) + obj._shape = tuple(shape) + obj._expr = expr + return obj + + @property + def shape(self): + return self._shape + + @property + def expr(self): + return self._expr + + def doit(self, *args, **kwargs): + if kwargs.get("deep", True): + expr = self.expr.doit(*args, **kwargs) + else: + expr = self.expr + if isinstance(expr, (MatrixBase, NDimArray)): + return expr.reshape(*self.shape) + return Reshape(expr, self.shape) + + def as_explicit(self): + ee = self.expr + if hasattr(ee, "as_explicit"): + ee = ee.as_explicit() + if isinstance(ee, MatrixBase): + from sympy import Array + ee = Array(ee) + elif isinstance(ee, MatrixExpr): + return self + return ee.reshape(*self.shape) + + +class _ArgE: + """ + The ``_ArgE`` object contains references to the array expression + (``.element``) and a list containing the information about index + contractions (``.indices``). + + Index contractions are numbered and contracted indices show the number of + the contraction. Uncontracted indices have ``None`` value. + + For example: + ``_ArgE(M, [None, 3])`` + This object means that expression ``M`` is part of an array contraction + and has two indices, the first is not contracted (value ``None``), + the second index is contracted to the 4th (i.e. number ``3``) group of the + array contraction object. + """ + indices: list[int | None] + + def __init__(self, element, indices: list[int | None] | None = None): + self.element = element + if indices is None: + self.indices = [None for i in range(get_rank(element))] + else: + self.indices = indices + + def __str__(self): + return "_ArgE(%s, %s)" % (self.element, self.indices) + + __repr__ = __str__ + + +class _IndPos: + """ + Index position, requiring two integers in the constructor: + + - arg: the position of the argument in the tensor product, + - rel: the relative position of the index inside the argument. + """ + def __init__(self, arg: int, rel: int): + self.arg = arg + self.rel = rel + + def __str__(self): + return "_IndPos(%i, %i)" % (self.arg, self.rel) + + __repr__ = __str__ + + def __iter__(self): + yield from [self.arg, self.rel] + + +class _EditArrayContraction: + """ + Utility class to help manipulate array contraction objects. + + This class takes as input an ``ArrayContraction`` object and turns it into + an editable object. + + The field ``args_with_ind`` of this class is a list of ``_ArgE`` objects + which can be used to easily edit the contraction structure of the + expression. + + Once editing is finished, the ``ArrayContraction`` object may be recreated + by calling the ``.to_array_contraction()`` method. + """ + + def __init__(self, base_array: typing.Union[ArrayContraction, ArrayDiagonal, ArrayTensorProduct]): + + expr: Basic + diagonalized: tuple[tuple[int, ...], ...] + contraction_indices: list[tuple[int]] + if isinstance(base_array, ArrayContraction): + mapping = _get_mapping_from_subranks(base_array.subranks) + expr = base_array.expr + contraction_indices = base_array.contraction_indices + diagonalized = () + elif isinstance(base_array, ArrayDiagonal): + + if isinstance(base_array.expr, ArrayContraction): + mapping = _get_mapping_from_subranks(base_array.expr.subranks) + expr = base_array.expr.expr + diagonalized = ArrayContraction._push_indices_down(base_array.expr.contraction_indices, base_array.diagonal_indices) + contraction_indices = base_array.expr.contraction_indices + elif isinstance(base_array.expr, ArrayTensorProduct): + mapping = {} + expr = base_array.expr + diagonalized = base_array.diagonal_indices + contraction_indices = [] + else: + mapping = {} + expr = base_array.expr + diagonalized = base_array.diagonal_indices + contraction_indices = [] + + elif isinstance(base_array, ArrayTensorProduct): + expr = base_array + contraction_indices = [] + diagonalized = () + else: + raise NotImplementedError() + + if isinstance(expr, ArrayTensorProduct): + args = list(expr.args) + else: + args = [expr] + + args_with_ind: list[_ArgE] = [_ArgE(arg) for arg in args] + for i, contraction_tuple in enumerate(contraction_indices): + for j in contraction_tuple: + arg_pos, rel_pos = mapping[j] + args_with_ind[arg_pos].indices[rel_pos] = i + self.args_with_ind: list[_ArgE] = args_with_ind + self.number_of_contraction_indices: int = len(contraction_indices) + self._track_permutation: list[list[int]] | None = None + + mapping = _get_mapping_from_subranks(base_array.subranks) + + # Trick: add diagonalized indices as negative indices into the editor object: + for i, e in enumerate(diagonalized): + for j in e: + arg_pos, rel_pos = mapping[j] + self.args_with_ind[arg_pos].indices[rel_pos] = -1 - i + + def insert_after(self, arg: _ArgE, new_arg: _ArgE): + pos = self.args_with_ind.index(arg) + self.args_with_ind.insert(pos + 1, new_arg) + + def get_new_contraction_index(self): + self.number_of_contraction_indices += 1 + return self.number_of_contraction_indices - 1 + + def refresh_indices(self): + updates = {} + for arg_with_ind in self.args_with_ind: + updates.update({i: -1 for i in arg_with_ind.indices if i is not None}) + for i, e in enumerate(sorted(updates)): + updates[e] = i + self.number_of_contraction_indices = len(updates) + for arg_with_ind in self.args_with_ind: + arg_with_ind.indices = [updates.get(i, None) for i in arg_with_ind.indices] + + def merge_scalars(self): + scalars = [] + for arg_with_ind in self.args_with_ind: + if len(arg_with_ind.indices) == 0: + scalars.append(arg_with_ind) + for i in scalars: + self.args_with_ind.remove(i) + scalar = Mul.fromiter([i.element for i in scalars]) + if len(self.args_with_ind) == 0: + self.args_with_ind.append(_ArgE(scalar)) + else: + from sympy.tensor.array.expressions.from_array_to_matrix import _a2m_tensor_product + self.args_with_ind[0].element = _a2m_tensor_product(scalar, self.args_with_ind[0].element) + + def to_array_contraction(self): + + # Count the ranks of the arguments: + counter = 0 + # Create a collector for the new diagonal indices: + diag_indices = defaultdict(list) + + count_index_freq = Counter() + for arg_with_ind in self.args_with_ind: + count_index_freq.update(Counter(arg_with_ind.indices)) + + free_index_count = count_index_freq[None] + + # Construct the inverse permutation: + inv_perm1 = [] + inv_perm2 = [] + # Keep track of which diagonal indices have already been processed: + done = set() + + # Counter for the diagonal indices: + counter4 = 0 + + for arg_with_ind in self.args_with_ind: + # If some diagonalization axes have been removed, they should be + # permuted in order to keep the permutation. + # Add permutation here + counter2 = 0 # counter for the indices + for i in arg_with_ind.indices: + if i is None: + inv_perm1.append(counter4) + counter2 += 1 + counter4 += 1 + continue + if i >= 0: + continue + # Reconstruct the diagonal indices: + diag_indices[-1 - i].append(counter + counter2) + if count_index_freq[i] == 1 and i not in done: + inv_perm1.append(free_index_count - 1 - i) + done.add(i) + elif i not in done: + inv_perm2.append(free_index_count - 1 - i) + done.add(i) + counter2 += 1 + # Remove negative indices to restore a proper editor object: + arg_with_ind.indices = [i if i is not None and i >= 0 else None for i in arg_with_ind.indices] + counter += len([i for i in arg_with_ind.indices if i is None or i < 0]) + + inverse_permutation = inv_perm1 + inv_perm2 + permutation = _af_invert(inverse_permutation) + + # Get the diagonal indices after the detection of HadamardProduct in the expression: + diag_indices_filtered = [tuple(v) for v in diag_indices.values() if len(v) > 1] + + self.merge_scalars() + self.refresh_indices() + args = [arg.element for arg in self.args_with_ind] + contraction_indices = self.get_contraction_indices() + expr = _array_contraction(_array_tensor_product(*args), *contraction_indices) + expr2 = _array_diagonal(expr, *diag_indices_filtered) + if self._track_permutation is not None: + permutation2 = _af_invert([j for i in self._track_permutation for j in i]) + expr2 = _permute_dims(expr2, permutation2) + + expr3 = _permute_dims(expr2, permutation) + return expr3 + + def get_contraction_indices(self) -> list[list[int]]: + contraction_indices: list[list[int]] = [[] for i in range(self.number_of_contraction_indices)] + current_position: int = 0 + for arg_with_ind in self.args_with_ind: + for j in arg_with_ind.indices: + if j is not None: + contraction_indices[j].append(current_position) + current_position += 1 + return contraction_indices + + def get_mapping_for_index(self, ind) -> list[_IndPos]: + if ind >= self.number_of_contraction_indices: + raise ValueError("index value exceeding the index range") + positions: list[_IndPos] = [] + for i, arg_with_ind in enumerate(self.args_with_ind): + for j, arg_ind in enumerate(arg_with_ind.indices): + if ind == arg_ind: + positions.append(_IndPos(i, j)) + return positions + + def get_contraction_indices_to_ind_rel_pos(self) -> list[list[_IndPos]]: + contraction_indices: list[list[_IndPos]] = [[] for i in range(self.number_of_contraction_indices)] + for i, arg_with_ind in enumerate(self.args_with_ind): + for j, ind in enumerate(arg_with_ind.indices): + if ind is not None: + contraction_indices[ind].append(_IndPos(i, j)) + return contraction_indices + + def count_args_with_index(self, index: int) -> int: + """ + Count the number of arguments that have the given index. + """ + counter: int = 0 + for arg_with_ind in self.args_with_ind: + if index in arg_with_ind.indices: + counter += 1 + return counter + + def get_args_with_index(self, index: int) -> list[_ArgE]: + """ + Get a list of arguments having the given index. + """ + ret: list[_ArgE] = [i for i in self.args_with_ind if index in i.indices] + return ret + + @property + def number_of_diagonal_indices(self): + data = set() + for arg in self.args_with_ind: + data.update({i for i in arg.indices if i is not None and i < 0}) + return len(data) + + def track_permutation_start(self): + permutation = [] + perm_diag = [] + counter = 0 + counter2 = -1 + for arg_with_ind in self.args_with_ind: + perm = [] + for i in arg_with_ind.indices: + if i is not None: + if i < 0: + perm_diag.append(counter2) + counter2 -= 1 + continue + perm.append(counter) + counter += 1 + permutation.append(perm) + max_ind = max(max(i) if i else -1 for i in permutation) if permutation else -1 + perm_diag = [max_ind - i for i in perm_diag] + self._track_permutation = permutation + [perm_diag] + + def track_permutation_merge(self, destination: _ArgE, from_element: _ArgE): + index_destination = self.args_with_ind.index(destination) + index_element = self.args_with_ind.index(from_element) + self._track_permutation[index_destination].extend(self._track_permutation[index_element]) # type: ignore + self._track_permutation.pop(index_element) # type: ignore + + def get_absolute_free_range(self, arg: _ArgE) -> typing.Tuple[int, int]: + """ + Return the range of the free indices of the arg as absolute positions + among all free indices. + """ + counter = 0 + for arg_with_ind in self.args_with_ind: + number_free_indices = len([i for i in arg_with_ind.indices if i is None]) + if arg_with_ind == arg: + return counter, counter + number_free_indices + counter += number_free_indices + raise IndexError("argument not found") + + def get_absolute_range(self, arg: _ArgE) -> typing.Tuple[int, int]: + """ + Return the absolute range of indices for arg, disregarding dummy + indices. + """ + counter = 0 + for arg_with_ind in self.args_with_ind: + number_indices = len(arg_with_ind.indices) + if arg_with_ind == arg: + return counter, counter + number_indices + counter += number_indices + raise IndexError("argument not found") + + +def get_rank(expr): + if isinstance(expr, (MatrixExpr, MatrixElement)): + return 2 + if isinstance(expr, _CodegenArrayAbstract): + return len(expr.shape) + if isinstance(expr, NDimArray): + return expr.rank() + if isinstance(expr, Indexed): + return expr.rank + if isinstance(expr, IndexedBase): + shape = expr.shape + if shape is None: + return -1 + else: + return len(shape) + if hasattr(expr, "shape"): + return len(expr.shape) + return 0 + + +def _get_subrank(expr): + if isinstance(expr, _CodegenArrayAbstract): + return expr.subrank() + return get_rank(expr) + + +def _get_subranks(expr): + if isinstance(expr, _CodegenArrayAbstract): + return expr.subranks + else: + return [get_rank(expr)] + + +def get_shape(expr): + if hasattr(expr, "shape"): + return expr.shape + return () + + +def nest_permutation(expr): + if isinstance(expr, PermuteDims): + return expr.nest_permutation() + else: + return expr + + +def _array_tensor_product(*args, **kwargs): + return ArrayTensorProduct(*args, canonicalize=True, **kwargs) + + +def _array_contraction(expr, *contraction_indices, **kwargs): + return ArrayContraction(expr, *contraction_indices, canonicalize=True, **kwargs) + + +def _array_diagonal(expr, *diagonal_indices, **kwargs): + return ArrayDiagonal(expr, *diagonal_indices, canonicalize=True, **kwargs) + + +def _permute_dims(expr, permutation, **kwargs): + return PermuteDims(expr, permutation, canonicalize=True, **kwargs) + + +def _array_add(*args, **kwargs): + return ArrayAdd(*args, canonicalize=True, **kwargs) + + +def _get_array_element_or_slice(expr, indices): + return ArrayElement(expr, indices) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/arrayexpr_derivatives.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/arrayexpr_derivatives.py new file mode 100644 index 0000000000000000000000000000000000000000..ab44a6fbf715ac7f2b8c287dcc84a49289f2dd76 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/arrayexpr_derivatives.py @@ -0,0 +1,194 @@ +import operator +from functools import reduce, singledispatch + +from sympy.core.expr import Expr +from sympy.core.singleton import S +from sympy.matrices.expressions.hadamard import HadamardProduct +from sympy.matrices.expressions.inverse import Inverse +from sympy.matrices.expressions.matexpr import (MatrixExpr, MatrixSymbol) +from sympy.matrices.expressions.special import Identity, OneMatrix +from sympy.matrices.expressions.transpose import Transpose +from sympy.combinatorics.permutations import _af_invert +from sympy.matrices.expressions.applyfunc import ElementwiseApplyFunction +from sympy.tensor.array.expressions.array_expressions import ( + _ArrayExpr, ZeroArray, ArraySymbol, ArrayTensorProduct, ArrayAdd, + PermuteDims, ArrayDiagonal, ArrayElementwiseApplyFunc, get_rank, + get_shape, ArrayContraction, _array_tensor_product, _array_contraction, + _array_diagonal, _array_add, _permute_dims, Reshape) +from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array + + +@singledispatch +def array_derive(expr, x): + """ + Derivatives (gradients) for array expressions. + """ + raise NotImplementedError(f"not implemented for type {type(expr)}") + + +@array_derive.register(Expr) +def _(expr: Expr, x: _ArrayExpr): + return ZeroArray(*x.shape) + + +@array_derive.register(ArrayTensorProduct) +def _(expr: ArrayTensorProduct, x: Expr): + args = expr.args + addend_list = [] + for i, arg in enumerate(expr.args): + darg = array_derive(arg, x) + if darg == 0: + continue + args_prev = args[:i] + args_succ = args[i+1:] + shape_prev = reduce(operator.add, map(get_shape, args_prev), ()) + shape_succ = reduce(operator.add, map(get_shape, args_succ), ()) + addend = _array_tensor_product(*args_prev, darg, *args_succ) + tot1 = len(get_shape(x)) + tot2 = tot1 + len(shape_prev) + tot3 = tot2 + len(get_shape(arg)) + tot4 = tot3 + len(shape_succ) + perm = list(range(tot1, tot2)) + \ + list(range(tot1)) + list(range(tot2, tot3)) + \ + list(range(tot3, tot4)) + addend = _permute_dims(addend, _af_invert(perm)) + addend_list.append(addend) + if len(addend_list) == 1: + return addend_list[0] + elif len(addend_list) == 0: + return S.Zero + else: + return _array_add(*addend_list) + + +@array_derive.register(ArraySymbol) +def _(expr: ArraySymbol, x: _ArrayExpr): + if expr == x: + return _permute_dims( + ArrayTensorProduct.fromiter(Identity(i) for i in expr.shape), + [2*i for i in range(len(expr.shape))] + [2*i+1 for i in range(len(expr.shape))] + ) + return ZeroArray(*(x.shape + expr.shape)) + + +@array_derive.register(MatrixSymbol) +def _(expr: MatrixSymbol, x: _ArrayExpr): + m, n = expr.shape + if expr == x: + return _permute_dims( + _array_tensor_product(Identity(m), Identity(n)), + [0, 2, 1, 3] + ) + return ZeroArray(*(x.shape + expr.shape)) + + +@array_derive.register(Identity) +def _(expr: Identity, x: _ArrayExpr): + return ZeroArray(*(x.shape + expr.shape)) + + +@array_derive.register(OneMatrix) +def _(expr: OneMatrix, x: _ArrayExpr): + return ZeroArray(*(x.shape + expr.shape)) + + +@array_derive.register(Transpose) +def _(expr: Transpose, x: Expr): + # D(A.T, A) ==> (m,n,i,j) ==> D(A_ji, A_mn) = d_mj d_ni + # D(B.T, A) ==> (m,n,i,j) ==> D(B_ji, A_mn) + fd = array_derive(expr.arg, x) + return _permute_dims(fd, [0, 1, 3, 2]) + + +@array_derive.register(Inverse) +def _(expr: Inverse, x: Expr): + mat = expr.I + dexpr = array_derive(mat, x) + tp = _array_tensor_product(-expr, dexpr, expr) + mp = _array_contraction(tp, (1, 4), (5, 6)) + pp = _permute_dims(mp, [1, 2, 0, 3]) + return pp + + +@array_derive.register(ElementwiseApplyFunction) +def _(expr: ElementwiseApplyFunction, x: Expr): + assert get_rank(expr) == 2 + assert get_rank(x) == 2 + fdiff = expr._get_function_fdiff() + dexpr = array_derive(expr.expr, x) + tp = _array_tensor_product( + ElementwiseApplyFunction(fdiff, expr.expr), + dexpr + ) + td = _array_diagonal( + tp, (0, 4), (1, 5) + ) + return td + + +@array_derive.register(ArrayElementwiseApplyFunc) +def _(expr: ArrayElementwiseApplyFunc, x: Expr): + fdiff = expr._get_function_fdiff() + subexpr = expr.expr + dsubexpr = array_derive(subexpr, x) + tp = _array_tensor_product( + dsubexpr, + ArrayElementwiseApplyFunc(fdiff, subexpr) + ) + b = get_rank(x) + c = get_rank(expr) + diag_indices = [(b + i, b + c + i) for i in range(c)] + return _array_diagonal(tp, *diag_indices) + + +@array_derive.register(MatrixExpr) +def _(expr: MatrixExpr, x: Expr): + cg = convert_matrix_to_array(expr) + return array_derive(cg, x) + + +@array_derive.register(HadamardProduct) +def _(expr: HadamardProduct, x: Expr): + raise NotImplementedError() + + +@array_derive.register(ArrayContraction) +def _(expr: ArrayContraction, x: Expr): + fd = array_derive(expr.expr, x) + rank_x = len(get_shape(x)) + contraction_indices = expr.contraction_indices + new_contraction_indices = [tuple(j + rank_x for j in i) for i in contraction_indices] + return _array_contraction(fd, *new_contraction_indices) + + +@array_derive.register(ArrayDiagonal) +def _(expr: ArrayDiagonal, x: Expr): + dsubexpr = array_derive(expr.expr, x) + rank_x = len(get_shape(x)) + diag_indices = [[j + rank_x for j in i] for i in expr.diagonal_indices] + return _array_diagonal(dsubexpr, *diag_indices) + + +@array_derive.register(ArrayAdd) +def _(expr: ArrayAdd, x: Expr): + return _array_add(*[array_derive(arg, x) for arg in expr.args]) + + +@array_derive.register(PermuteDims) +def _(expr: PermuteDims, x: Expr): + de = array_derive(expr.expr, x) + perm = [0, 1] + [i + 2 for i in expr.permutation.array_form] + return _permute_dims(de, perm) + + +@array_derive.register(Reshape) +def _(expr: Reshape, x: Expr): + de = array_derive(expr.expr, x) + return Reshape(de, get_shape(x) + expr.shape) + + +def matrix_derive(expr, x): + from sympy.tensor.array.expressions.from_array_to_matrix import convert_array_to_matrix + ce = convert_matrix_to_array(expr) + dce = array_derive(ce, x) + return convert_array_to_matrix(dce).doit() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_array_to_indexed.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_array_to_indexed.py new file mode 100644 index 0000000000000000000000000000000000000000..1929c3401e131cca0a83080131ead9198b37bcbb --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_array_to_indexed.py @@ -0,0 +1,12 @@ +from sympy.tensor.array.expressions import from_array_to_indexed +from sympy.utilities.decorator import deprecated + + +_conv_to_from_decorator = deprecated( + "module has been renamed by replacing 'conv_' with 'from_' in its name", + deprecated_since_version="1.11", + active_deprecations_target="deprecated-conv-array-expr-module-names", +) + + +convert_array_to_indexed = _conv_to_from_decorator(from_array_to_indexed.convert_array_to_indexed) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_array_to_matrix.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_array_to_matrix.py new file mode 100644 index 0000000000000000000000000000000000000000..2708e74aaa98d6ee38eae46d97d4483a546e0776 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_array_to_matrix.py @@ -0,0 +1,6 @@ +from sympy.tensor.array.expressions import from_array_to_matrix +from sympy.tensor.array.expressions.conv_array_to_indexed import _conv_to_from_decorator + +convert_array_to_matrix = _conv_to_from_decorator(from_array_to_matrix.convert_array_to_matrix) +_array2matrix = _conv_to_from_decorator(from_array_to_matrix._array2matrix) +_remove_trivial_dims = _conv_to_from_decorator(from_array_to_matrix._remove_trivial_dims) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_indexed_to_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_indexed_to_array.py new file mode 100644 index 0000000000000000000000000000000000000000..6058b31f20778834ea23a01553d594b7965eb6bb --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_indexed_to_array.py @@ -0,0 +1,4 @@ +from sympy.tensor.array.expressions import from_indexed_to_array +from sympy.tensor.array.expressions.conv_array_to_indexed import _conv_to_from_decorator + +convert_indexed_to_array = _conv_to_from_decorator(from_indexed_to_array.convert_indexed_to_array) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_matrix_to_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_matrix_to_array.py new file mode 100644 index 0000000000000000000000000000000000000000..46469df60703c237527c0b2834235309640afe7c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/conv_matrix_to_array.py @@ -0,0 +1,4 @@ +from sympy.tensor.array.expressions import from_matrix_to_array +from sympy.tensor.array.expressions.conv_array_to_indexed import _conv_to_from_decorator + +convert_matrix_to_array = _conv_to_from_decorator(from_matrix_to_array.convert_matrix_to_array) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_array_to_indexed.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_array_to_indexed.py new file mode 100644 index 0000000000000000000000000000000000000000..9eb86e7cfbe31ebfe7c9649803d9cb5e34b98276 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_array_to_indexed.py @@ -0,0 +1,84 @@ +import collections.abc +import operator +from itertools import accumulate + +from sympy import Mul, Sum, Dummy, Add +from sympy.tensor.array.expressions import PermuteDims, ArrayAdd, ArrayElementwiseApplyFunc, Reshape +from sympy.tensor.array.expressions.array_expressions import ArrayTensorProduct, get_rank, ArrayContraction, \ + ArrayDiagonal, get_shape, _get_array_element_or_slice, _ArrayExpr +from sympy.tensor.array.expressions.utils import _apply_permutation_to_list + + +def convert_array_to_indexed(expr, indices): + return _ConvertArrayToIndexed().do_convert(expr, indices) + + +class _ConvertArrayToIndexed: + + def __init__(self): + self.count_dummies = 0 + + def do_convert(self, expr, indices): + if isinstance(expr, ArrayTensorProduct): + cumul = list(accumulate([0] + [get_rank(arg) for arg in expr.args])) + indices_grp = [indices[cumul[i]:cumul[i+1]] for i in range(len(expr.args))] + return Mul.fromiter(self.do_convert(arg, ind) for arg, ind in zip(expr.args, indices_grp)) + if isinstance(expr, ArrayContraction): + new_indices = [None for i in range(get_rank(expr.expr))] + limits = [] + bottom_shape = get_shape(expr.expr) + for contraction_index_grp in expr.contraction_indices: + d = Dummy(f"d{self.count_dummies}") + self.count_dummies += 1 + dim = bottom_shape[contraction_index_grp[0]] + limits.append((d, 0, dim-1)) + for i in contraction_index_grp: + new_indices[i] = d + j = 0 + for i in range(len(new_indices)): + if new_indices[i] is None: + new_indices[i] = indices[j] + j += 1 + newexpr = self.do_convert(expr.expr, new_indices) + return Sum(newexpr, *limits) + if isinstance(expr, ArrayDiagonal): + new_indices = [None for i in range(get_rank(expr.expr))] + ind_pos = expr._push_indices_down(expr.diagonal_indices, list(range(len(indices))), get_rank(expr)) + for i, index in zip(ind_pos, indices): + if isinstance(i, collections.abc.Iterable): + for j in i: + new_indices[j] = index + else: + new_indices[i] = index + newexpr = self.do_convert(expr.expr, new_indices) + return newexpr + if isinstance(expr, PermuteDims): + permuted_indices = _apply_permutation_to_list(expr.permutation, indices) + return self.do_convert(expr.expr, permuted_indices) + if isinstance(expr, ArrayAdd): + return Add.fromiter(self.do_convert(arg, indices) for arg in expr.args) + if isinstance(expr, _ArrayExpr): + return expr.__getitem__(tuple(indices)) + if isinstance(expr, ArrayElementwiseApplyFunc): + return expr.function(self.do_convert(expr.expr, indices)) + if isinstance(expr, Reshape): + shape_up = expr.shape + shape_down = get_shape(expr.expr) + cumul = list(accumulate([1] + list(reversed(shape_up)), operator.mul)) + one_index = Add.fromiter(i*s for i, s in zip(reversed(indices), cumul)) + dest_indices = [None for _ in shape_down] + c = 1 + for i, e in enumerate(reversed(shape_down)): + if c == 1: + if i == len(shape_down) - 1: + dest_indices[i] = one_index + else: + dest_indices[i] = one_index % e + elif i == len(shape_down) - 1: + dest_indices[i] = one_index // c + else: + dest_indices[i] = one_index // c % e + c *= e + dest_indices.reverse() + return self.do_convert(expr.expr, dest_indices) + return _get_array_element_or_slice(expr, indices) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_array_to_matrix.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_array_to_matrix.py new file mode 100644 index 0000000000000000000000000000000000000000..debfdd7eb5c4533996b3d72b55d679be3daf3afe --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_array_to_matrix.py @@ -0,0 +1,1004 @@ +from __future__ import annotations +import itertools +from collections import defaultdict +from typing import FrozenSet +from functools import singledispatch +from itertools import accumulate + +from sympy import MatMul, Basic, Wild, KroneckerProduct +from sympy.assumptions.ask import (Q, ask) +from sympy.core.mul import Mul +from sympy.core.singleton import S +from sympy.matrices.expressions.diagonal import DiagMatrix +from sympy.matrices.expressions.hadamard import hadamard_product, HadamardPower +from sympy.matrices.expressions.matexpr import MatrixExpr +from sympy.matrices.expressions.special import (Identity, ZeroMatrix, OneMatrix) +from sympy.matrices.expressions.trace import Trace +from sympy.matrices.expressions.transpose import Transpose +from sympy.combinatorics.permutations import _af_invert, Permutation +from sympy.matrices.matrixbase import MatrixBase +from sympy.matrices.expressions.applyfunc import ElementwiseApplyFunction +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.tensor.array.expressions.array_expressions import PermuteDims, ArrayDiagonal, \ + ArrayTensorProduct, OneArray, get_rank, _get_subrank, ZeroArray, ArrayContraction, \ + ArrayAdd, _CodegenArrayAbstract, get_shape, ArrayElementwiseApplyFunc, _ArrayExpr, _EditArrayContraction, _ArgE, \ + ArrayElement, _array_tensor_product, _array_contraction, _array_diagonal, _array_add, _permute_dims +from sympy.tensor.array.expressions.utils import _get_mapping_from_subranks + + +def _get_candidate_for_matmul_from_contraction(scan_indices: list[int | None], remaining_args: list[_ArgE]) -> tuple[_ArgE | None, bool, int]: + + scan_indices_int: list[int] = [i for i in scan_indices if i is not None] + if len(scan_indices_int) == 0: + return None, False, -1 + + transpose: bool = False + candidate: _ArgE | None = None + candidate_index: int = -1 + for arg_with_ind2 in remaining_args: + if not isinstance(arg_with_ind2.element, MatrixExpr): + continue + for index in scan_indices_int: + if candidate_index != -1 and candidate_index != index: + # A candidate index has already been selected, check + # repetitions only for that index: + continue + if index in arg_with_ind2.indices: + if set(arg_with_ind2.indices) == {index}: + # Index repeated twice in arg_with_ind2 + candidate = None + break + if candidate is None: + candidate = arg_with_ind2 + candidate_index = index + transpose = (index == arg_with_ind2.indices[1]) + else: + # Index repeated more than twice, break + candidate = None + break + return candidate, transpose, candidate_index + + +def _insert_candidate_into_editor(editor: _EditArrayContraction, arg_with_ind: _ArgE, candidate: _ArgE, transpose1: bool, transpose2: bool): + other = candidate.element + other_index: int | None + if transpose2: + other = Transpose(other) + other_index = candidate.indices[0] + else: + other_index = candidate.indices[1] + new_element = (Transpose(arg_with_ind.element) if transpose1 else arg_with_ind.element) * other + editor.args_with_ind.remove(candidate) + new_arge = _ArgE(new_element) + return new_arge, other_index + + +def _support_function_tp1_recognize(contraction_indices, args): + if len(contraction_indices) == 0: + return _a2m_tensor_product(*args) + + ac = _array_contraction(_array_tensor_product(*args), *contraction_indices) + editor = _EditArrayContraction(ac) + editor.track_permutation_start() + + while True: + flag_stop = True + for i, arg_with_ind in enumerate(editor.args_with_ind): + if not isinstance(arg_with_ind.element, MatrixExpr): + continue + + first_index = arg_with_ind.indices[0] + second_index = arg_with_ind.indices[1] + + first_frequency = editor.count_args_with_index(first_index) + second_frequency = editor.count_args_with_index(second_index) + + if first_index is not None and first_frequency == 1 and first_index == second_index: + flag_stop = False + arg_with_ind.element = Trace(arg_with_ind.element)._normalize() + arg_with_ind.indices = [] + break + + scan_indices = [] + if first_frequency == 2: + scan_indices.append(first_index) + if second_frequency == 2: + scan_indices.append(second_index) + + candidate, transpose, found_index = _get_candidate_for_matmul_from_contraction(scan_indices, editor.args_with_ind[i+1:]) + if candidate is not None: + flag_stop = False + editor.track_permutation_merge(arg_with_ind, candidate) + transpose1 = found_index == first_index + new_arge, other_index = _insert_candidate_into_editor(editor, arg_with_ind, candidate, transpose1, transpose) + if found_index == first_index: + new_arge.indices = [second_index, other_index] + else: + new_arge.indices = [first_index, other_index] + set_indices = set(new_arge.indices) + if len(set_indices) == 1 and set_indices != {None}: + # This is a trace: + new_arge.element = Trace(new_arge.element)._normalize() + new_arge.indices = [] + editor.args_with_ind[i] = new_arge + # TODO: is this break necessary? + break + + if flag_stop: + break + + editor.refresh_indices() + return editor.to_array_contraction() + + +def _find_trivial_matrices_rewrite(expr: ArrayTensorProduct): + # If there are matrices of trivial shape in the tensor product (i.e. shape + # (1, 1)), try to check if there is a suitable non-trivial MatMul where the + # expression can be inserted. + + # For example, if "a" has shape (1, 1) and "b" has shape (k, 1), the + # expressions "_array_tensor_product(a, b*b.T)" can be rewritten as + # "b*a*b.T" + + trivial_matrices = [] + pos: int | None = None # must be initialized else causes UnboundLocalError + first: MatrixExpr | None = None # may cause UnboundLocalError if not initialized + second: MatrixExpr | None = None # may cause UnboundLocalError if not initialized + removed: list[int] = [] + counter: int = 0 + args: list[Basic | None] = list(expr.args) + for i, arg in enumerate(expr.args): + if isinstance(arg, MatrixExpr): + if arg.shape == (1, 1): + trivial_matrices.append(arg) + args[i] = None + removed.extend([counter, counter+1]) + elif pos is None and isinstance(arg, MatMul): + margs = arg.args + for j, e in enumerate(margs): + if isinstance(e, MatrixExpr) and e.shape[1] == 1: + pos = i + first = MatMul.fromiter(margs[:j+1]) + second = MatMul.fromiter(margs[j+1:]) + break + counter += get_rank(arg) + if pos is None: + return expr, [] + args[pos] = (first*MatMul.fromiter(i for i in trivial_matrices)*second).doit() + return _array_tensor_product(*[i for i in args if i is not None]), removed + + +def _find_trivial_kronecker_products_broadcast(expr: ArrayTensorProduct): + newargs: list[Basic] = [] + removed = [] + count_dims = 0 + for arg in expr.args: + count_dims += get_rank(arg) + shape = get_shape(arg) + current_range = [count_dims-i for i in range(len(shape), 0, -1)] + if (shape == (1, 1) and len(newargs) > 0 and 1 not in get_shape(newargs[-1]) and + isinstance(newargs[-1], MatrixExpr) and isinstance(arg, MatrixExpr)): + # KroneckerProduct object allows the trick of broadcasting: + newargs[-1] = KroneckerProduct(newargs[-1], arg) + removed.extend(current_range) + elif 1 not in shape and len(newargs) > 0 and get_shape(newargs[-1]) == (1, 1): + # Broadcast: + newargs[-1] = KroneckerProduct(newargs[-1], arg) + prev_range = [i for i in range(min(current_range)) if i not in removed] + removed.extend(prev_range[-2:]) + else: + newargs.append(arg) + return _array_tensor_product(*newargs), removed + + +@singledispatch +def _array2matrix(expr): + return expr + + +@_array2matrix.register(ZeroArray) +def _(expr: ZeroArray): + if get_rank(expr) == 2: + return ZeroMatrix(*expr.shape) + else: + return expr + + +@_array2matrix.register(ArrayTensorProduct) +def _(expr: ArrayTensorProduct): + return _a2m_tensor_product(*[_array2matrix(arg) for arg in expr.args]) + + +@_array2matrix.register(ArrayContraction) +def _(expr: ArrayContraction): + expr = expr.flatten_contraction_of_diagonal() + expr = identify_removable_identity_matrices(expr) + expr = expr.split_multiple_contractions() + expr = identify_hadamard_products(expr) + if not isinstance(expr, ArrayContraction): + return _array2matrix(expr) + subexpr = expr.expr + contraction_indices: tuple[tuple[int]] = expr.contraction_indices + if contraction_indices == ((0,), (1,)) or ( + contraction_indices == ((0,),) and subexpr.shape[1] == 1 + ) or ( + contraction_indices == ((1,),) and subexpr.shape[0] == 1 + ): + shape = subexpr.shape + subexpr = _array2matrix(subexpr) + if isinstance(subexpr, MatrixExpr): + return OneMatrix(1, shape[0])*subexpr*OneMatrix(shape[1], 1) + if isinstance(subexpr, ArrayTensorProduct): + newexpr = _array_contraction(_array2matrix(subexpr), *contraction_indices) + contraction_indices = newexpr.contraction_indices + if any(i > 2 for i in newexpr.subranks): + addends = _array_add(*[_a2m_tensor_product(*j) for j in itertools.product(*[i.args if isinstance(i, + ArrayAdd) else [i] for i in expr.expr.args])]) + newexpr = _array_contraction(addends, *contraction_indices) + if isinstance(newexpr, ArrayAdd): + ret = _array2matrix(newexpr) + return ret + assert isinstance(newexpr, ArrayContraction) + ret = _support_function_tp1_recognize(contraction_indices, list(newexpr.expr.args)) + return ret + elif not isinstance(subexpr, _CodegenArrayAbstract): + ret = _array2matrix(subexpr) + if isinstance(ret, MatrixExpr): + assert expr.contraction_indices == ((0, 1),) + return _a2m_trace(ret) + else: + return _array_contraction(ret, *expr.contraction_indices) + + +@_array2matrix.register(ArrayDiagonal) +def _(expr: ArrayDiagonal): + pexpr = _array_diagonal(_array2matrix(expr.expr), *expr.diagonal_indices) + pexpr = identify_hadamard_products(pexpr) + if isinstance(pexpr, ArrayDiagonal): + pexpr = _array_diag2contr_diagmatrix(pexpr) + if expr == pexpr: + return expr + return _array2matrix(pexpr) + + +@_array2matrix.register(PermuteDims) +def _(expr: PermuteDims): + if expr.permutation.array_form == [1, 0]: + return _a2m_transpose(_array2matrix(expr.expr)) + elif isinstance(expr.expr, ArrayTensorProduct): + ranks = expr.expr.subranks + inv_permutation = expr.permutation**(-1) + newrange = [inv_permutation(i) for i in range(sum(ranks))] + newpos = [] + counter = 0 + for rank in ranks: + newpos.append(newrange[counter:counter+rank]) + counter += rank + newargs = [] + newperm = [] + scalars = [] + for pos, arg in zip(newpos, expr.expr.args): + if len(pos) == 0: + scalars.append(_array2matrix(arg)) + elif pos == sorted(pos): + newargs.append((_array2matrix(arg), pos[0])) + newperm.extend(pos) + elif len(pos) == 2: + newargs.append((_a2m_transpose(_array2matrix(arg)), pos[0])) + newperm.extend(reversed(pos)) + else: + raise NotImplementedError() + newargs = [i[0] for i in newargs] + return _permute_dims(_a2m_tensor_product(*scalars, *newargs), _af_invert(newperm)) + elif isinstance(expr.expr, ArrayContraction): + mat_mul_lines = _array2matrix(expr.expr) + if not isinstance(mat_mul_lines, ArrayTensorProduct): + return _permute_dims(mat_mul_lines, expr.permutation) + # TODO: this assumes that all arguments are matrices, it may not be the case: + permutation = Permutation(2*len(mat_mul_lines.args)-1)*expr.permutation + permuted = [permutation(i) for i in range(2*len(mat_mul_lines.args))] + args_array = [None for i in mat_mul_lines.args] + for i in range(len(mat_mul_lines.args)): + p1 = permuted[2*i] + p2 = permuted[2*i+1] + if p1 // 2 != p2 // 2: + return _permute_dims(mat_mul_lines, permutation) + if p1 > p2: + args_array[i] = _a2m_transpose(mat_mul_lines.args[p1 // 2]) + else: + args_array[i] = mat_mul_lines.args[p1 // 2] + return _a2m_tensor_product(*args_array) + else: + return expr + + +@_array2matrix.register(ArrayAdd) +def _(expr: ArrayAdd): + addends = [_array2matrix(arg) for arg in expr.args] + return _a2m_add(*addends) + + +@_array2matrix.register(ArrayElementwiseApplyFunc) +def _(expr: ArrayElementwiseApplyFunc): + subexpr = _array2matrix(expr.expr) + if isinstance(subexpr, MatrixExpr): + if subexpr.shape != (1, 1): + d = expr.function.bound_symbols[0] + w = Wild("w", exclude=[d]) + p = Wild("p", exclude=[d]) + m = expr.function.expr.match(w*d**p) + if m is not None: + return m[w]*HadamardPower(subexpr, m[p]) + return ElementwiseApplyFunction(expr.function, subexpr) + else: + return ArrayElementwiseApplyFunc(expr.function, subexpr) + + +@_array2matrix.register(ArrayElement) +def _(expr: ArrayElement): + ret = _array2matrix(expr.name) + if isinstance(ret, MatrixExpr): + return MatrixElement(ret, *expr.indices) + return ArrayElement(ret, expr.indices) + + +@singledispatch +def _remove_trivial_dims(expr): + return expr, [] + + +@_remove_trivial_dims.register(ArrayTensorProduct) +def _(expr: ArrayTensorProduct): + # Recognize expressions like [x, y] with shape (k, 1, k, 1) as `x*y.T`. + # The matrix expression has to be equivalent to the tensor product of the + # matrices, with trivial dimensions (i.e. dim=1) dropped. + # That is, add contractions over trivial dimensions: + + removed = [] + newargs = [] + cumul = list(accumulate([0] + [get_rank(arg) for arg in expr.args])) + pending = None + prev_i = None + for i, arg in enumerate(expr.args): + current_range = list(range(cumul[i], cumul[i+1])) + if isinstance(arg, OneArray): + removed.extend(current_range) + continue + if not isinstance(arg, (MatrixExpr, MatrixBase)): + rarg, rem = _remove_trivial_dims(arg) + removed.extend(rem) + newargs.append(rarg) + continue + elif getattr(arg, "is_Identity", False) and arg.shape == (1, 1): + if arg.shape == (1, 1): + # Ignore identity matrices of shape (1, 1) - they are equivalent to scalar 1. + removed.extend(current_range) + continue + elif arg.shape == (1, 1): + arg, _ = _remove_trivial_dims(arg) + # Matrix is equivalent to scalar: + if len(newargs) == 0: + newargs.append(arg) + elif 1 in get_shape(newargs[-1]): + if newargs[-1].shape[1] == 1: + newargs[-1] = newargs[-1]*arg + else: + newargs[-1] = arg*newargs[-1] + removed.extend(current_range) + else: + newargs.append(arg) + elif 1 in arg.shape: + k = [i for i in arg.shape if i != 1][0] + if pending is None: + pending = k + prev_i = i + newargs.append(arg) + elif pending == k: + prev = newargs[-1] + if prev.shape[0] == 1: + d1 = cumul[prev_i] # type: ignore + prev = _a2m_transpose(prev) + else: + d1 = cumul[prev_i] + 1 # type: ignore + if arg.shape[1] == 1: + d2 = cumul[i] + 1 + arg = _a2m_transpose(arg) + else: + d2 = cumul[i] + newargs[-1] = prev*arg + pending = None + removed.extend([d1, d2]) + else: + newargs.append(arg) + pending = k + prev_i = i + else: + newargs.append(arg) + pending = None + newexpr, newremoved = _a2m_tensor_product(*newargs), sorted(removed) + if isinstance(newexpr, ArrayTensorProduct): + newexpr, newremoved2 = _find_trivial_matrices_rewrite(newexpr) + newremoved = _combine_removed(-1, newremoved, newremoved2) + if isinstance(newexpr, ArrayTensorProduct): + newexpr, newremoved2 = _find_trivial_kronecker_products_broadcast(newexpr) + newremoved = _combine_removed(-1, newremoved, newremoved2) + return newexpr, newremoved + + +@_remove_trivial_dims.register(ArrayAdd) +def _(expr: ArrayAdd): + rec = [_remove_trivial_dims(arg) for arg in expr.args] + newargs, removed = zip(*rec) + if len({get_shape(i) for i in newargs}) > 1: + return expr, [] + if len(removed) == 0: + return expr, removed + removed1 = removed[0] + return _a2m_add(*newargs), removed1 + + +@_remove_trivial_dims.register(PermuteDims) +def _(expr: PermuteDims): + subexpr, subremoved = _remove_trivial_dims(expr.expr) + p = expr.permutation.array_form + pinv = _af_invert(expr.permutation.array_form) + shift = list(accumulate([1 if i in subremoved else 0 for i in range(len(p))])) + premoved = [pinv[i] for i in subremoved] + p2 = [e - shift[e] for e in p if e not in subremoved] + # TODO: check if subremoved should be permuted as well... + newexpr = _permute_dims(subexpr, p2) + premoved = sorted(premoved) + if newexpr != expr: + newexpr, removed2 = _remove_trivial_dims(_array2matrix(newexpr)) + premoved = _combine_removed(-1, premoved, removed2) + return newexpr, premoved + + +@_remove_trivial_dims.register(ArrayContraction) +def _(expr: ArrayContraction): + new_expr, removed0 = _array_contraction_to_diagonal_multiple_identity(expr) + if new_expr != expr: + new_expr2, removed1 = _remove_trivial_dims(_array2matrix(new_expr)) + removed = _combine_removed(-1, removed0, removed1) + return new_expr2, removed + rank1 = get_rank(expr) + expr, removed1 = remove_identity_matrices(expr) + if not isinstance(expr, ArrayContraction): + expr2, removed2 = _remove_trivial_dims(expr) + return expr2, _combine_removed(rank1, removed1, removed2) + newexpr, removed2 = _remove_trivial_dims(expr.expr) + shifts = list(accumulate([1 if i in removed2 else 0 for i in range(get_rank(expr.expr))])) + new_contraction_indices = [tuple(j for j in i if j not in removed2) for i in expr.contraction_indices] + # Remove possible empty tuples "()": + new_contraction_indices = [i for i in new_contraction_indices if len(i) > 0] + contraction_indices_flat = [j for i in expr.contraction_indices for j in i] + removed2 = [i for i in removed2 if i not in contraction_indices_flat] + new_contraction_indices = [tuple(j - shifts[j] for j in i) for i in new_contraction_indices] + # Shift removed2: + removed2 = ArrayContraction._push_indices_up(expr.contraction_indices, removed2) + removed = _combine_removed(rank1, removed1, removed2) + return _array_contraction(newexpr, *new_contraction_indices), list(removed) + + +def _remove_diagonalized_identity_matrices(expr: ArrayDiagonal): + assert isinstance(expr, ArrayDiagonal) + editor = _EditArrayContraction(expr) + mapping = {i: {j for j in editor.args_with_ind if i in j.indices} for i in range(-1, -1-editor.number_of_diagonal_indices, -1)} + removed = [] + counter: int = 0 + for i, arg_with_ind in enumerate(editor.args_with_ind): + counter += len(arg_with_ind.indices) + if isinstance(arg_with_ind.element, Identity): + if None in arg_with_ind.indices and any(i is not None and (i < 0) == True for i in arg_with_ind.indices): + diag_ind = [j for j in arg_with_ind.indices if j is not None][0] + other = [j for j in mapping[diag_ind] if j != arg_with_ind][0] + if not isinstance(other.element, MatrixExpr): + continue + if 1 not in other.element.shape: + continue + if None not in other.indices: + continue + editor.args_with_ind[i].element = None + none_index = other.indices.index(None) + other.element = DiagMatrix(other.element) + other_range = editor.get_absolute_range(other) + removed.extend([other_range[0] + none_index]) + editor.args_with_ind = [i for i in editor.args_with_ind if i.element is not None] + removed = ArrayDiagonal._push_indices_up(expr.diagonal_indices, removed, get_rank(expr.expr)) + return editor.to_array_contraction(), removed + + +@_remove_trivial_dims.register(ArrayDiagonal) +def _(expr: ArrayDiagonal): + newexpr, removed = _remove_trivial_dims(expr.expr) + shifts = list(accumulate([0] + [1 if i in removed else 0 for i in range(get_rank(expr.expr))])) + new_diag_indices_map = {i: tuple(j for j in i if j not in removed) for i in expr.diagonal_indices} + for old_diag_tuple, new_diag_tuple in new_diag_indices_map.items(): + if len(new_diag_tuple) == 1: + removed = [i for i in removed if i not in old_diag_tuple] + new_diag_indices = [tuple(j - shifts[j] for j in i) for i in new_diag_indices_map.values()] + rank = get_rank(expr.expr) + removed = ArrayDiagonal._push_indices_up(expr.diagonal_indices, removed, rank) + removed = sorted(set(removed)) + # If there are single axes to diagonalize remaining, it means that their + # corresponding dimension has been removed, they no longer need diagonalization: + new_diag_indices = [i for i in new_diag_indices if len(i) > 0] + if len(new_diag_indices) > 0: + newexpr2 = _array_diagonal(newexpr, *new_diag_indices, allow_trivial_diags=True) + else: + newexpr2 = newexpr + if isinstance(newexpr2, ArrayDiagonal): + newexpr3, removed2 = _remove_diagonalized_identity_matrices(newexpr2) + removed = _combine_removed(-1, removed, removed2) + return newexpr3, removed + else: + return newexpr2, removed + + +@_remove_trivial_dims.register(ElementwiseApplyFunction) +def _(expr: ElementwiseApplyFunction): + subexpr, removed = _remove_trivial_dims(expr.expr) + if subexpr.shape == (1, 1): + # TODO: move this to ElementwiseApplyFunction + return expr.function(subexpr), removed + [0, 1] + return ElementwiseApplyFunction(expr.function, subexpr), [] + + +@_remove_trivial_dims.register(ArrayElementwiseApplyFunc) +def _(expr: ArrayElementwiseApplyFunc): + subexpr, removed = _remove_trivial_dims(expr.expr) + return ArrayElementwiseApplyFunc(expr.function, subexpr), removed + + +def convert_array_to_matrix(expr): + r""" + Recognize matrix expressions in codegen objects. + + If more than one matrix multiplication line have been detected, return a + list with the matrix expressions. + + Examples + ======== + + >>> from sympy.tensor.array.expressions.from_indexed_to_array import convert_indexed_to_array + >>> from sympy.tensor.array import tensorcontraction, tensorproduct + >>> from sympy import MatrixSymbol, Sum + >>> from sympy.abc import i, j, k, l, N + >>> from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array + >>> from sympy.tensor.array.expressions.from_array_to_matrix import convert_array_to_matrix + >>> A = MatrixSymbol("A", N, N) + >>> B = MatrixSymbol("B", N, N) + >>> C = MatrixSymbol("C", N, N) + >>> D = MatrixSymbol("D", N, N) + + >>> expr = Sum(A[i, j]*B[j, k], (j, 0, N-1)) + >>> cg = convert_indexed_to_array(expr) + >>> convert_array_to_matrix(cg) + A*B + >>> cg = convert_indexed_to_array(expr, first_indices=[k]) + >>> convert_array_to_matrix(cg) + B.T*A.T + + Transposition is detected: + + >>> expr = Sum(A[j, i]*B[j, k], (j, 0, N-1)) + >>> cg = convert_indexed_to_array(expr) + >>> convert_array_to_matrix(cg) + A.T*B + >>> cg = convert_indexed_to_array(expr, first_indices=[k]) + >>> convert_array_to_matrix(cg) + B.T*A + + Detect the trace: + + >>> expr = Sum(A[i, i], (i, 0, N-1)) + >>> cg = convert_indexed_to_array(expr) + >>> convert_array_to_matrix(cg) + Trace(A) + + Recognize some more complex traces: + + >>> expr = Sum(A[i, j]*B[j, i], (i, 0, N-1), (j, 0, N-1)) + >>> cg = convert_indexed_to_array(expr) + >>> convert_array_to_matrix(cg) + Trace(A*B) + + More complicated expressions: + + >>> expr = Sum(A[i, j]*B[k, j]*A[l, k], (j, 0, N-1), (k, 0, N-1)) + >>> cg = convert_indexed_to_array(expr) + >>> convert_array_to_matrix(cg) + A*B.T*A.T + + Expressions constructed from matrix expressions do not contain literal + indices, the positions of free indices are returned instead: + + >>> expr = A*B + >>> cg = convert_matrix_to_array(expr) + >>> convert_array_to_matrix(cg) + A*B + + If more than one line of matrix multiplications is detected, return + separate matrix multiplication factors embedded in a tensor product object: + + >>> cg = tensorcontraction(tensorproduct(A, B, C, D), (1, 2), (5, 6)) + >>> convert_array_to_matrix(cg) + ArrayTensorProduct(A*B, C*D) + + The two lines have free indices at axes 0, 3 and 4, 7, respectively. + """ + rec = _array2matrix(expr) + rec, removed = _remove_trivial_dims(rec) + return rec + + +def _array_diag2contr_diagmatrix(expr: ArrayDiagonal): + if isinstance(expr.expr, ArrayTensorProduct): + args = list(expr.expr.args) + diag_indices = list(expr.diagonal_indices) + mapping = _get_mapping_from_subranks([_get_subrank(arg) for arg in args]) + tuple_links = [[mapping[j] for j in i] for i in diag_indices] + contr_indices = [] + total_rank = get_rank(expr) + replaced = [False for arg in args] + for i, (abs_pos, rel_pos) in enumerate(zip(diag_indices, tuple_links)): + if len(abs_pos) != 2: + continue + (pos1_outer, pos1_inner), (pos2_outer, pos2_inner) = rel_pos + arg1 = args[pos1_outer] + arg2 = args[pos2_outer] + if get_rank(arg1) != 2 or get_rank(arg2) != 2: + if replaced[pos1_outer]: + diag_indices[i] = None + if replaced[pos2_outer]: + diag_indices[i] = None + continue + pos1_in2 = 1 - pos1_inner + pos2_in2 = 1 - pos2_inner + if arg1.shape[pos1_in2] == 1: + if arg1.shape[pos1_inner] != 1: + darg1 = DiagMatrix(arg1) + else: + darg1 = arg1 + args.append(darg1) + contr_indices.append(((pos2_outer, pos2_inner), (len(args)-1, pos1_inner))) + total_rank += 1 + diag_indices[i] = None + args[pos1_outer] = OneArray(arg1.shape[pos1_in2]) + replaced[pos1_outer] = True + elif arg2.shape[pos2_in2] == 1: + if arg2.shape[pos2_inner] != 1: + darg2 = DiagMatrix(arg2) + else: + darg2 = arg2 + args.append(darg2) + contr_indices.append(((pos1_outer, pos1_inner), (len(args)-1, pos2_inner))) + total_rank += 1 + diag_indices[i] = None + args[pos2_outer] = OneArray(arg2.shape[pos2_in2]) + replaced[pos2_outer] = True + diag_indices_new = [i for i in diag_indices if i is not None] + cumul = list(accumulate([0] + [get_rank(arg) for arg in args])) + contr_indices2 = [tuple(cumul[a] + b for a, b in i) for i in contr_indices] + tc = _array_contraction( + _array_tensor_product(*args), *contr_indices2 + ) + td = _array_diagonal(tc, *diag_indices_new) + return td + return expr + + +def _a2m_mul(*args): + if not any(isinstance(i, _CodegenArrayAbstract) for i in args): + from sympy.matrices.expressions.matmul import MatMul + return MatMul(*args).doit() + else: + return _array_contraction( + _array_tensor_product(*args), + *[(2*i-1, 2*i) for i in range(1, len(args))] + ) + + +def _a2m_tensor_product(*args): + scalars = [] + arrays = [] + for arg in args: + if isinstance(arg, (MatrixExpr, _ArrayExpr, _CodegenArrayAbstract)): + arrays.append(arg) + else: + scalars.append(arg) + scalar = Mul.fromiter(scalars) + if len(arrays) == 0: + return scalar + if scalar != 1: + if isinstance(arrays[0], _CodegenArrayAbstract): + arrays = [scalar] + arrays + else: + arrays[0] *= scalar + return _array_tensor_product(*arrays) + + +def _a2m_add(*args): + if not any(isinstance(i, _CodegenArrayAbstract) for i in args): + from sympy.matrices.expressions.matadd import MatAdd + return MatAdd(*args).doit() + else: + return _array_add(*args) + + +def _a2m_trace(arg): + if isinstance(arg, _CodegenArrayAbstract): + return _array_contraction(arg, (0, 1)) + else: + from sympy.matrices.expressions.trace import Trace + return Trace(arg) + + +def _a2m_transpose(arg): + if isinstance(arg, _CodegenArrayAbstract): + return _permute_dims(arg, [1, 0]) + else: + from sympy.matrices.expressions.transpose import Transpose + return Transpose(arg).doit() + + +def identify_hadamard_products(expr: ArrayContraction | ArrayDiagonal): + + editor: _EditArrayContraction = _EditArrayContraction(expr) + + map_contr_to_args: dict[FrozenSet, list[_ArgE]] = defaultdict(list) + map_ind_to_inds: dict[int | None, int] = defaultdict(int) + for arg_with_ind in editor.args_with_ind: + for ind in arg_with_ind.indices: + map_ind_to_inds[ind] += 1 + if None in arg_with_ind.indices: + continue + map_contr_to_args[frozenset(arg_with_ind.indices)].append(arg_with_ind) + + k: FrozenSet[int] + v: list[_ArgE] + for k, v in map_contr_to_args.items(): + make_trace: bool = False + if len(k) == 1 and next(iter(k)) >= 0 and sum(next(iter(k)) in i for i in map_contr_to_args) == 1: + # This is a trace: the arguments are fully contracted with only one + # index, and the index isn't used anywhere else: + make_trace = True + first_element = S.One + elif len(k) != 2: + # Hadamard product only defined for matrices: + continue + if len(v) == 1: + # Hadamard product with a single argument makes no sense: + continue + for ind in k: + if map_ind_to_inds[ind] <= 2: + # There is no other contraction, skip: + continue + + def check_transpose(x): + x = [i if i >= 0 else -1-i for i in x] + return x == sorted(x) + + # Check if expression is a trace: + if all(map_ind_to_inds[j] == len(v) and j >= 0 for j in k) and all(j >= 0 for j in k): + # This is a trace + make_trace = True + first_element = v[0].element + if not check_transpose(v[0].indices): + first_element = first_element.T # type: ignore + hadamard_factors = v[1:] + else: + hadamard_factors = v + + # This is a Hadamard product: + + hp = hadamard_product(*[i.element if check_transpose(i.indices) else Transpose(i.element) for i in hadamard_factors]) + hp_indices = v[0].indices + if not check_transpose(hadamard_factors[0].indices): + hp_indices = list(reversed(hp_indices)) + if make_trace: + hp = Trace(first_element*hp.T)._normalize() + hp_indices = [] + editor.insert_after(v[0], _ArgE(hp, hp_indices)) + for i in v: + editor.args_with_ind.remove(i) + + return editor.to_array_contraction() + + +def identify_removable_identity_matrices(expr): + editor = _EditArrayContraction(expr) + + flag = True + while flag: + flag = False + for arg_with_ind in editor.args_with_ind: + if isinstance(arg_with_ind.element, Identity): + k = arg_with_ind.element.shape[0] + # Candidate for removal: + if arg_with_ind.indices == [None, None]: + # Free identity matrix, will be cleared by _remove_trivial_dims: + continue + elif None in arg_with_ind.indices: + ind = [j for j in arg_with_ind.indices if j is not None][0] + counted = editor.count_args_with_index(ind) + if counted == 1: + # Identity matrix contracted only on one index with itself, + # transform to a OneArray(k) element: + editor.insert_after(arg_with_ind, OneArray(k)) + editor.args_with_ind.remove(arg_with_ind) + flag = True + break + elif counted > 2: + # Case counted = 2 is a matrix multiplication by identity matrix, skip it. + # Case counted > 2 is a multiple contraction, + # this is a case where the contraction becomes a diagonalization if the + # identity matrix is dropped. + continue + elif arg_with_ind.indices[0] == arg_with_ind.indices[1]: + ind = arg_with_ind.indices[0] + counted = editor.count_args_with_index(ind) + if counted > 1: + editor.args_with_ind.remove(arg_with_ind) + flag = True + break + else: + # This is a trace, skip it as it will be recognized somewhere else: + pass + elif ask(Q.diagonal(arg_with_ind.element)): + if arg_with_ind.indices == [None, None]: + continue + elif None in arg_with_ind.indices: + pass + elif arg_with_ind.indices[0] == arg_with_ind.indices[1]: + ind = arg_with_ind.indices[0] + counted = editor.count_args_with_index(ind) + if counted == 3: + # A_ai B_bi D_ii ==> A_ai D_ij B_bj + ind_new = editor.get_new_contraction_index() + other_args = [j for j in editor.args_with_ind if j != arg_with_ind] + other_args[1].indices = [ind_new if j == ind else j for j in other_args[1].indices] + arg_with_ind.indices = [ind, ind_new] + flag = True + break + + return editor.to_array_contraction() + + +def remove_identity_matrices(expr: ArrayContraction): + editor = _EditArrayContraction(expr) + removed: list[int] = [] + + permutation_map = {} + + free_indices = list(accumulate([0] + [sum(i is None for i in arg.indices) for arg in editor.args_with_ind])) + free_map = dict(zip(editor.args_with_ind, free_indices[:-1])) + + update_pairs = {} + + for ind in range(editor.number_of_contraction_indices): + args = editor.get_args_with_index(ind) + identity_matrices = [i for i in args if isinstance(i.element, Identity)] + number_identity_matrices = len(identity_matrices) + # If the contraction involves a non-identity matrix and multiple identity matrices: + if number_identity_matrices != len(args) - 1 or number_identity_matrices == 0: + continue + # Get the non-identity element: + non_identity = [i for i in args if not isinstance(i.element, Identity)][0] + # Check that all identity matrices have at least one free index + # (otherwise they would be contractions to some other elements) + if any(None not in i.indices for i in identity_matrices): + continue + # Mark the identity matrices for removal: + for i in identity_matrices: + i.element = None + removed.extend(range(free_map[i], free_map[i] + len([j for j in i.indices if j is None]))) + last_removed = removed.pop(-1) + update_pairs[last_removed, ind] = non_identity.indices[:] + # Remove the indices from the non-identity matrix, as the contraction + # no longer exists: + non_identity.indices = [None if i == ind else i for i in non_identity.indices] + + removed.sort() + + shifts = list(accumulate([1 if i in removed else 0 for i in range(get_rank(expr))])) + for (last_removed, ind), non_identity_indices in update_pairs.items(): + pos = [free_map[non_identity] + i for i, e in enumerate(non_identity_indices) if e == ind] + assert len(pos) == 1 + for j in pos: + permutation_map[j] = last_removed + + editor.args_with_ind = [i for i in editor.args_with_ind if i.element is not None] + ret_expr = editor.to_array_contraction() + permutation = [] + counter = 0 + counter2 = 0 + for j in range(get_rank(expr)): + if j in removed: + continue + if counter2 in permutation_map: + target = permutation_map[counter2] + permutation.append(target - shifts[target]) + counter2 += 1 + else: + while counter in permutation_map.values(): + counter += 1 + permutation.append(counter) + counter += 1 + counter2 += 1 + ret_expr2 = _permute_dims(ret_expr, _af_invert(permutation)) + return ret_expr2, removed + + +def _combine_removed(dim: int, removed1: list[int], removed2: list[int]) -> list[int]: + # Concatenate two axis removal operations as performed by + # _remove_trivial_dims, + removed1 = sorted(removed1) + removed2 = sorted(removed2) + i = 0 + j = 0 + removed = [] + while True: + if j >= len(removed2): + while i < len(removed1): + removed.append(removed1[i]) + i += 1 + break + elif i < len(removed1) and removed1[i] <= i + removed2[j]: + removed.append(removed1[i]) + i += 1 + else: + removed.append(i + removed2[j]) + j += 1 + return removed + + +def _array_contraction_to_diagonal_multiple_identity(expr: ArrayContraction): + editor = _EditArrayContraction(expr) + editor.track_permutation_start() + removed: list[int] = [] + diag_index_counter: int = 0 + for i in range(editor.number_of_contraction_indices): + identities = [] + args = [] + for j, arg in enumerate(editor.args_with_ind): + if i not in arg.indices: + continue + if isinstance(arg.element, Identity): + identities.append(arg) + else: + args.append(arg) + if len(identities) == 0: + continue + if len(args) + len(identities) < 3: + continue + new_diag_ind = -1 - diag_index_counter + diag_index_counter += 1 + # Variable "flag" to control whether to skip this contraction set: + flag: bool = True + for i1, id1 in enumerate(identities): + if None not in id1.indices: + flag = True + break + free_pos = list(range(*editor.get_absolute_free_range(id1)))[0] + editor._track_permutation[-1].append(free_pos) # type: ignore + id1.element = None + flag = False + break + if flag: + continue + for arg in identities[:i1] + identities[i1+1:]: + arg.element = None + removed.extend(range(*editor.get_absolute_free_range(arg))) + for arg in args: + arg.indices = [new_diag_ind if j == i else j for j in arg.indices] + for j, e in enumerate(editor.args_with_ind): + if e.element is None: + editor._track_permutation[j] = None # type: ignore + editor._track_permutation = [i for i in editor._track_permutation if i is not None] # type: ignore + # Renumber permutation array form in order to deal with deleted positions: + remap = {e: i for i, e in enumerate(sorted({k for j in editor._track_permutation for k in j}))} + editor._track_permutation = [[remap[j] for j in i] for i in editor._track_permutation] + editor.args_with_ind = [i for i in editor.args_with_ind if i.element is not None] + new_expr = editor.to_array_contraction() + return new_expr, removed diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_indexed_to_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_indexed_to_array.py new file mode 100644 index 0000000000000000000000000000000000000000..c219a205c4305bd7070e5117978146224521c58c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_indexed_to_array.py @@ -0,0 +1,257 @@ +from collections import defaultdict + +from sympy import Function +from sympy.combinatorics.permutations import _af_invert +from sympy.concrete.summations import Sum +from sympy.core.add import Add +from sympy.core.mul import Mul +from sympy.core.numbers import Integer +from sympy.core.power import Pow +from sympy.core.sorting import default_sort_key +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.tensor.array.expressions import ArrayElementwiseApplyFunc +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.combinatorics import Permutation +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.tensor.array.expressions.array_expressions import ArrayDiagonal, \ + get_shape, ArrayElement, _array_tensor_product, _array_diagonal, _array_contraction, _array_add, \ + _permute_dims, OneArray, ArrayAdd +from sympy.tensor.array.expressions.utils import _get_argindex, _get_diagonal_indices + + +def convert_indexed_to_array(expr, first_indices=None): + r""" + Parse indexed expression into a form useful for code generation. + + Examples + ======== + + >>> from sympy.tensor.array.expressions.from_indexed_to_array import convert_indexed_to_array + >>> from sympy import MatrixSymbol, Sum, symbols + + >>> i, j, k, d = symbols("i j k d") + >>> M = MatrixSymbol("M", d, d) + >>> N = MatrixSymbol("N", d, d) + + Recognize the trace in summation form: + + >>> expr = Sum(M[i, i], (i, 0, d-1)) + >>> convert_indexed_to_array(expr) + ArrayContraction(M, (0, 1)) + + Recognize the extraction of the diagonal by using the same index `i` on + both axes of the matrix: + + >>> expr = M[i, i] + >>> convert_indexed_to_array(expr) + ArrayDiagonal(M, (0, 1)) + + This function can help perform the transformation expressed in two + different mathematical notations as: + + `\sum_{j=0}^{N-1} A_{i,j} B_{j,k} \Longrightarrow \mathbf{A}\cdot \mathbf{B}` + + Recognize the matrix multiplication in summation form: + + >>> expr = Sum(M[i, j]*N[j, k], (j, 0, d-1)) + >>> convert_indexed_to_array(expr) + ArrayContraction(ArrayTensorProduct(M, N), (1, 2)) + + Specify that ``k`` has to be the starting index: + + >>> convert_indexed_to_array(expr, first_indices=[k]) + ArrayContraction(ArrayTensorProduct(N, M), (0, 3)) + """ + + result, indices = _convert_indexed_to_array(expr) + + if any(isinstance(i, (int, Integer)) for i in indices): + result = ArrayElement(result, indices) + indices = [] + + if not first_indices: + return result + + def _check_is_in(elem, indices): + if elem in indices: + return True + if any(elem in i for i in indices if isinstance(i, frozenset)): + return True + return False + + repl = {j: i for i in indices if isinstance(i, frozenset) for j in i} + first_indices = [repl.get(i, i) for i in first_indices] + for i in first_indices: + if not _check_is_in(i, indices): + first_indices.remove(i) + first_indices.extend([i for i in indices if not _check_is_in(i, first_indices)]) + + def _get_pos(elem, indices): + if elem in indices: + return indices.index(elem) + for i, e in enumerate(indices): + if not isinstance(e, frozenset): + continue + if elem in e: + return i + raise ValueError("not found") + + permutation = _af_invert([_get_pos(i, first_indices) for i in indices]) + if isinstance(result, ArrayAdd): + return _array_add(*[_permute_dims(arg, permutation) for arg in result.args]) + else: + return _permute_dims(result, permutation) + + +def _convert_indexed_to_array(expr): + if isinstance(expr, Sum): + function = expr.function + summation_indices = expr.variables + subexpr, subindices = _convert_indexed_to_array(function) + subindicessets = {j: i for i in subindices if isinstance(i, frozenset) for j in i} + summation_indices = sorted({subindicessets.get(i, i) for i in summation_indices}, key=default_sort_key) + # TODO: check that Kronecker delta is only contracted to one other element: + kronecker_indices = set() + if isinstance(function, Mul): + for arg in function.args: + if not isinstance(arg, KroneckerDelta): + continue + arg_indices = sorted(set(arg.indices), key=default_sort_key) + if len(arg_indices) == 2: + kronecker_indices.update(arg_indices) + kronecker_indices = sorted(kronecker_indices, key=default_sort_key) + # Check dimensional consistency: + shape = get_shape(subexpr) + if shape: + for ind, istart, iend in expr.limits: + i = _get_argindex(subindices, ind) + if istart != 0 or iend+1 != shape[i]: + raise ValueError("summation index and array dimension mismatch: %s" % ind) + contraction_indices = [] + subindices = list(subindices) + if isinstance(subexpr, ArrayDiagonal): + diagonal_indices = list(subexpr.diagonal_indices) + dindices = subindices[-len(diagonal_indices):] + subindices = subindices[:-len(diagonal_indices)] + for index in summation_indices: + if index in dindices: + position = dindices.index(index) + contraction_indices.append(diagonal_indices[position]) + diagonal_indices[position] = None + diagonal_indices = [i for i in diagonal_indices if i is not None] + for i, ind in enumerate(subindices): + if ind in summation_indices: + pass + if diagonal_indices: + subexpr = _array_diagonal(subexpr.expr, *diagonal_indices) + else: + subexpr = subexpr.expr + + axes_contraction = defaultdict(list) + for i, ind in enumerate(subindices): + include = all(j not in kronecker_indices for j in ind) if isinstance(ind, frozenset) else ind not in kronecker_indices + if ind in summation_indices and include: + axes_contraction[ind].append(i) + subindices[i] = None + for k, v in axes_contraction.items(): + if any(i in kronecker_indices for i in k) if isinstance(k, frozenset) else k in kronecker_indices: + continue + contraction_indices.append(tuple(v)) + free_indices = [i for i in subindices if i is not None] + indices_ret = list(free_indices) + indices_ret.sort(key=lambda x: free_indices.index(x)) + return _array_contraction( + subexpr, + *contraction_indices, + free_indices=free_indices + ), tuple(indices_ret) + if isinstance(expr, Mul): + args, indices = zip(*[_convert_indexed_to_array(arg) for arg in expr.args]) + # Check if there are KroneckerDelta objects: + kronecker_delta_repl = {} + for arg in args: + if not isinstance(arg, KroneckerDelta): + continue + # Diagonalize two indices: + i, j = arg.indices + kindices = set(arg.indices) + if i in kronecker_delta_repl: + kindices.update(kronecker_delta_repl[i]) + if j in kronecker_delta_repl: + kindices.update(kronecker_delta_repl[j]) + kindices = frozenset(kindices) + for index in kindices: + kronecker_delta_repl[index] = kindices + # Remove KroneckerDelta objects, their relations should be handled by + # ArrayDiagonal: + newargs = [] + newindices = [] + for arg, loc_indices in zip(args, indices): + if isinstance(arg, KroneckerDelta): + continue + newargs.append(arg) + newindices.append(loc_indices) + flattened_indices = [kronecker_delta_repl.get(j, j) for i in newindices for j in i] + diagonal_indices, ret_indices = _get_diagonal_indices(flattened_indices) + tp = _array_tensor_product(*newargs) + if diagonal_indices: + return _array_diagonal(tp, *diagonal_indices), ret_indices + else: + return tp, ret_indices + if isinstance(expr, MatrixElement): + indices = expr.args[1:] + diagonal_indices, ret_indices = _get_diagonal_indices(indices) + if diagonal_indices: + return _array_diagonal(expr.args[0], *diagonal_indices), ret_indices + else: + return expr.args[0], ret_indices + if isinstance(expr, ArrayElement): + indices = expr.indices + diagonal_indices, ret_indices = _get_diagonal_indices(indices) + if diagonal_indices: + return _array_diagonal(expr.name, *diagonal_indices), ret_indices + else: + return expr.name, ret_indices + if isinstance(expr, Indexed): + indices = expr.indices + diagonal_indices, ret_indices = _get_diagonal_indices(indices) + if diagonal_indices: + return _array_diagonal(expr.base, *diagonal_indices), ret_indices + else: + return expr.args[0], ret_indices + if isinstance(expr, IndexedBase): + raise NotImplementedError + if isinstance(expr, KroneckerDelta): + return expr, expr.indices + if isinstance(expr, Add): + args, indices = zip(*[_convert_indexed_to_array(arg) for arg in expr.args]) + args = list(args) + # Check if all indices are compatible. Otherwise expand the dimensions: + index0 = [] + shape0 = [] + for arg, arg_indices in zip(args, indices): + arg_indices_set = set(arg_indices) + arg_indices_missing = arg_indices_set.difference(index0) + index0.extend([i for i in arg_indices if i in arg_indices_missing]) + arg_shape = get_shape(arg) + shape0.extend([arg_shape[i] for i, e in enumerate(arg_indices) if e in arg_indices_missing]) + for i, (arg, arg_indices) in enumerate(zip(args, indices)): + if len(arg_indices) < len(index0): + missing_indices_pos = [i for i, e in enumerate(index0) if e not in arg_indices] + missing_shape = [shape0[i] for i in missing_indices_pos] + arg_indices = tuple(index0[j] for j in missing_indices_pos) + arg_indices + args[i] = _array_tensor_product(OneArray(*missing_shape), args[i]) + permutation = Permutation([arg_indices.index(j) for j in index0]) + # Perform index permutations: + args[i] = _permute_dims(args[i], permutation) + return _array_add(*args), tuple(index0) + if isinstance(expr, Pow): + subexpr, subindices = _convert_indexed_to_array(expr.base) + if isinstance(expr.exp, (int, Integer)): + diags = zip(*[(2*i, 2*i + 1) for i in range(expr.exp)]) + arr = _array_diagonal(_array_tensor_product(*[subexpr for i in range(expr.exp)]), *diags) + return arr, subindices + if isinstance(expr, Function): + subexpr, subindices = _convert_indexed_to_array(expr.args[0]) + return ArrayElementwiseApplyFunc(type(expr), subexpr), subindices + return expr, () diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_matrix_to_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_matrix_to_array.py new file mode 100644 index 0000000000000000000000000000000000000000..8f66961727f6338318d65876a7768802773e4f2d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/from_matrix_to_array.py @@ -0,0 +1,87 @@ +from sympy import KroneckerProduct +from sympy.core.basic import Basic +from sympy.core.function import Lambda +from sympy.core.mul import Mul +from sympy.core.numbers import Integer +from sympy.core.power import Pow +from sympy.core.singleton import S +from sympy.core.symbol import (Dummy, symbols) +from sympy.matrices.expressions.hadamard import (HadamardPower, HadamardProduct) +from sympy.matrices.expressions.matadd import MatAdd +from sympy.matrices.expressions.matmul import MatMul +from sympy.matrices.expressions.matpow import MatPow +from sympy.matrices.expressions.trace import Trace +from sympy.matrices.expressions.transpose import Transpose +from sympy.matrices.expressions.matexpr import MatrixExpr +from sympy.tensor.array.expressions.array_expressions import \ + ArrayElementwiseApplyFunc, _array_tensor_product, _array_contraction, \ + _array_diagonal, _array_add, _permute_dims, Reshape + + +def convert_matrix_to_array(expr: Basic) -> Basic: + if isinstance(expr, MatMul): + args_nonmat = [] + args = [] + for arg in expr.args: + if isinstance(arg, MatrixExpr): + args.append(arg) + else: + args_nonmat.append(convert_matrix_to_array(arg)) + contractions = [(2*i+1, 2*i+2) for i in range(len(args)-1)] + scalar = _array_tensor_product(*args_nonmat) if args_nonmat else S.One + if scalar == 1: + tprod = _array_tensor_product( + *[convert_matrix_to_array(arg) for arg in args]) + else: + tprod = _array_tensor_product( + scalar, + *[convert_matrix_to_array(arg) for arg in args]) + return _array_contraction( + tprod, + *contractions + ) + elif isinstance(expr, MatAdd): + return _array_add( + *[convert_matrix_to_array(arg) for arg in expr.args] + ) + elif isinstance(expr, Transpose): + return _permute_dims( + convert_matrix_to_array(expr.args[0]), [1, 0] + ) + elif isinstance(expr, Trace): + inner_expr: MatrixExpr = convert_matrix_to_array(expr.arg) # type: ignore + return _array_contraction(inner_expr, (0, len(inner_expr.shape) - 1)) + elif isinstance(expr, Mul): + return _array_tensor_product(*[convert_matrix_to_array(i) for i in expr.args]) + elif isinstance(expr, Pow): + base = convert_matrix_to_array(expr.base) + if (expr.exp > 0) == True: + return _array_tensor_product(*[base for i in range(expr.exp)]) + else: + return expr + elif isinstance(expr, MatPow): + base = convert_matrix_to_array(expr.base) + if expr.exp.is_Integer != True: + b = symbols("b", cls=Dummy) + return ArrayElementwiseApplyFunc(Lambda(b, b**expr.exp), convert_matrix_to_array(base)) + elif (expr.exp > 0) == True: + return convert_matrix_to_array(MatMul.fromiter(base for i in range(expr.exp))) + else: + return expr + elif isinstance(expr, HadamardProduct): + tp = _array_tensor_product(*[convert_matrix_to_array(arg) for arg in expr.args]) + diag = [[2*i for i in range(len(expr.args))], [2*i+1 for i in range(len(expr.args))]] + return _array_diagonal(tp, *diag) + elif isinstance(expr, HadamardPower): + base, exp = expr.args + if isinstance(exp, Integer) and exp > 0: + return convert_matrix_to_array(HadamardProduct.fromiter(base for i in range(exp))) + else: + d = Dummy("d") + return ArrayElementwiseApplyFunc(Lambda(d, d**exp), base) + elif isinstance(expr, KroneckerProduct): + kp_args = [convert_matrix_to_array(arg) for arg in expr.args] + permutation = [2*i for i in range(len(kp_args))] + [2*i + 1 for i in range(len(kp_args))] + return Reshape(_permute_dims(_array_tensor_product(*kp_args), permutation), expr.shape) + else: + return expr diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_array_expressions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_array_expressions.py new file mode 100644 index 0000000000000000000000000000000000000000..63fb79ab7ced7bff5ecb55b1764f43e29f98609d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_array_expressions.py @@ -0,0 +1,808 @@ +import random + +from sympy import tensordiagonal, eye, KroneckerDelta, Array +from sympy.core.symbol import symbols +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.matrices.expressions.diagonal import DiagMatrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.special import ZeroMatrix +from sympy.tensor.array.arrayop import (permutedims, tensorcontraction, tensorproduct) +from sympy.tensor.array.dense_ndim_array import ImmutableDenseNDimArray +from sympy.combinatorics import Permutation +from sympy.tensor.array.expressions.array_expressions import ZeroArray, OneArray, ArraySymbol, ArrayElement, \ + PermuteDims, ArrayContraction, ArrayTensorProduct, ArrayDiagonal, \ + ArrayAdd, nest_permutation, ArrayElementwiseApplyFunc, _EditArrayContraction, _ArgE, _array_tensor_product, \ + _array_contraction, _array_diagonal, _array_add, _permute_dims, Reshape +from sympy.testing.pytest import raises + +i, j, k, l, m, n = symbols("i j k l m n") + + +M = ArraySymbol("M", (k, k)) +N = ArraySymbol("N", (k, k)) +P = ArraySymbol("P", (k, k)) +Q = ArraySymbol("Q", (k, k)) + +A = ArraySymbol("A", (k, k)) +B = ArraySymbol("B", (k, k)) +C = ArraySymbol("C", (k, k)) +D = ArraySymbol("D", (k, k)) + +X = ArraySymbol("X", (k, k)) +Y = ArraySymbol("Y", (k, k)) + +a = ArraySymbol("a", (k, 1)) +b = ArraySymbol("b", (k, 1)) +c = ArraySymbol("c", (k, 1)) +d = ArraySymbol("d", (k, 1)) + + +def test_array_symbol_and_element(): + A = ArraySymbol("A", (2,)) + A0 = ArrayElement(A, (0,)) + A1 = ArrayElement(A, (1,)) + assert A[0] == A0 + assert A[1] != A0 + assert A.as_explicit() == ImmutableDenseNDimArray([A0, A1]) + + A2 = tensorproduct(A, A) + assert A2.shape == (2, 2) + # TODO: not yet supported: + # assert A2.as_explicit() == Array([[A[0]*A[0], A[1]*A[0]], [A[0]*A[1], A[1]*A[1]]]) + A3 = tensorcontraction(A2, (0, 1)) + assert A3.shape == () + # TODO: not yet supported: + # assert A3.as_explicit() == Array([]) + + A = ArraySymbol("A", (2, 3, 4)) + Ae = A.as_explicit() + assert Ae == ImmutableDenseNDimArray( + [[[ArrayElement(A, (i, j, k)) for k in range(4)] for j in range(3)] for i in range(2)]) + + p = _permute_dims(A, Permutation(0, 2, 1)) + assert isinstance(p, PermuteDims) + + A = ArraySymbol("A", (2,)) + raises(IndexError, lambda: A[()]) + raises(IndexError, lambda: A[0, 1]) + raises(ValueError, lambda: A[-1]) + raises(ValueError, lambda: A[2]) + + O = OneArray(3, 4) + Z = ZeroArray(m, n) + + raises(IndexError, lambda: O[()]) + raises(IndexError, lambda: O[1, 2, 3]) + raises(ValueError, lambda: O[3, 0]) + raises(ValueError, lambda: O[0, 4]) + + assert O[1, 2] == 1 + assert Z[1, 2] == 0 + + +def test_zero_array(): + assert ZeroArray() == 0 + assert ZeroArray().is_Integer + + za = ZeroArray(3, 2, 4) + assert za.shape == (3, 2, 4) + za_e = za.as_explicit() + assert za_e.shape == (3, 2, 4) + + m, n, k = symbols("m n k") + za = ZeroArray(m, n, k, 2) + assert za.shape == (m, n, k, 2) + raises(ValueError, lambda: za.as_explicit()) + + +def test_one_array(): + assert OneArray() == 1 + assert OneArray().is_Integer + + oa = OneArray(3, 2, 4) + assert oa.shape == (3, 2, 4) + oa_e = oa.as_explicit() + assert oa_e.shape == (3, 2, 4) + + m, n, k = symbols("m n k") + oa = OneArray(m, n, k, 2) + assert oa.shape == (m, n, k, 2) + raises(ValueError, lambda: oa.as_explicit()) + + +def test_arrayexpr_contraction_construction(): + + cg = _array_contraction(A) + assert cg == A + + cg = _array_contraction(_array_tensor_product(A, B), (1, 0)) + assert cg == _array_contraction(_array_tensor_product(A, B), (0, 1)) + + cg = _array_contraction(_array_tensor_product(M, N), (0, 1)) + indtup = cg._get_contraction_tuples() + assert indtup == [[(0, 0), (0, 1)]] + assert cg._contraction_tuples_to_contraction_indices(cg.expr, indtup) == [(0, 1)] + + cg = _array_contraction(_array_tensor_product(M, N), (1, 2)) + indtup = cg._get_contraction_tuples() + assert indtup == [[(0, 1), (1, 0)]] + assert cg._contraction_tuples_to_contraction_indices(cg.expr, indtup) == [(1, 2)] + + cg = _array_contraction(_array_tensor_product(M, M, N), (1, 4), (2, 5)) + indtup = cg._get_contraction_tuples() + assert indtup == [[(0, 0), (1, 1)], [(0, 1), (2, 0)]] + assert cg._contraction_tuples_to_contraction_indices(cg.expr, indtup) == [(0, 3), (1, 4)] + + # Test removal of trivial contraction: + assert _array_contraction(a, (1,)) == a + assert _array_contraction( + _array_tensor_product(a, b), (0, 2), (1,), (3,)) == _array_contraction( + _array_tensor_product(a, b), (0, 2)) + + +def test_arrayexpr_array_flatten(): + + # Flatten nested ArrayTensorProduct objects: + expr1 = _array_tensor_product(M, N) + expr2 = _array_tensor_product(P, Q) + expr = _array_tensor_product(expr1, expr2) + assert expr == _array_tensor_product(M, N, P, Q) + assert expr.args == (M, N, P, Q) + + # Flatten mixed ArrayTensorProduct and ArrayContraction objects: + cg1 = _array_contraction(expr1, (1, 2)) + cg2 = _array_contraction(expr2, (0, 3)) + + expr = _array_tensor_product(cg1, cg2) + assert expr == _array_contraction(_array_tensor_product(M, N, P, Q), (1, 2), (4, 7)) + + expr = _array_tensor_product(M, cg1) + assert expr == _array_contraction(_array_tensor_product(M, M, N), (3, 4)) + + # Flatten nested ArrayContraction objects: + cgnested = _array_contraction(cg1, (0, 1)) + assert cgnested == _array_contraction(_array_tensor_product(M, N), (0, 3), (1, 2)) + + cgnested = _array_contraction(_array_tensor_product(cg1, cg2), (0, 3)) + assert cgnested == _array_contraction(_array_tensor_product(M, N, P, Q), (0, 6), (1, 2), (4, 7)) + + cg3 = _array_contraction(_array_tensor_product(M, N, P, Q), (1, 3), (2, 4)) + cgnested = _array_contraction(cg3, (0, 1)) + assert cgnested == _array_contraction(_array_tensor_product(M, N, P, Q), (0, 5), (1, 3), (2, 4)) + + cgnested = _array_contraction(cg3, (0, 3), (1, 2)) + assert cgnested == _array_contraction(_array_tensor_product(M, N, P, Q), (0, 7), (1, 3), (2, 4), (5, 6)) + + cg4 = _array_contraction(_array_tensor_product(M, N, P, Q), (1, 5), (3, 7)) + cgnested = _array_contraction(cg4, (0, 1)) + assert cgnested == _array_contraction(_array_tensor_product(M, N, P, Q), (0, 2), (1, 5), (3, 7)) + + cgnested = _array_contraction(cg4, (0, 1), (2, 3)) + assert cgnested == _array_contraction(_array_tensor_product(M, N, P, Q), (0, 2), (1, 5), (3, 7), (4, 6)) + + cg = _array_diagonal(cg4) + assert cg == cg4 + assert isinstance(cg, type(cg4)) + + # Flatten nested ArrayDiagonal objects: + cg1 = _array_diagonal(expr1, (1, 2)) + cg2 = _array_diagonal(expr2, (0, 3)) + cg3 = _array_diagonal(_array_tensor_product(M, N, P, Q), (1, 3), (2, 4)) + cg4 = _array_diagonal(_array_tensor_product(M, N, P, Q), (1, 5), (3, 7)) + + cgnested = _array_diagonal(cg1, (0, 1)) + assert cgnested == _array_diagonal(_array_tensor_product(M, N), (1, 2), (0, 3)) + + cgnested = _array_diagonal(cg3, (1, 2)) + assert cgnested == _array_diagonal(_array_tensor_product(M, N, P, Q), (1, 3), (2, 4), (5, 6)) + + cgnested = _array_diagonal(cg4, (1, 2)) + assert cgnested == _array_diagonal(_array_tensor_product(M, N, P, Q), (1, 5), (3, 7), (2, 4)) + + cg = _array_add(M, N) + cg2 = _array_add(cg, P) + assert isinstance(cg2, ArrayAdd) + assert cg2.args == (M, N, P) + assert cg2.shape == (k, k) + + expr = _array_tensor_product(_array_diagonal(X, (0, 1)), _array_diagonal(A, (0, 1))) + assert expr == _array_diagonal(_array_tensor_product(X, A), (0, 1), (2, 3)) + + expr1 = _array_diagonal(_array_tensor_product(X, A), (1, 2)) + expr2 = _array_tensor_product(expr1, a) + assert expr2 == _permute_dims(_array_diagonal(_array_tensor_product(X, A, a), (1, 2)), [0, 1, 4, 2, 3]) + + expr1 = _array_contraction(_array_tensor_product(X, A), (1, 2)) + expr2 = _array_tensor_product(expr1, a) + assert isinstance(expr2, ArrayContraction) + assert isinstance(expr2.expr, ArrayTensorProduct) + + cg = _array_tensor_product(_array_diagonal(_array_tensor_product(A, X, Y), (0, 3), (1, 5)), a, b) + assert cg == _permute_dims(_array_diagonal(_array_tensor_product(A, X, Y, a, b), (0, 3), (1, 5)), [0, 1, 6, 7, 2, 3, 4, 5]) + + +def test_arrayexpr_array_diagonal(): + cg = _array_diagonal(M, (1, 0)) + assert cg == _array_diagonal(M, (0, 1)) + + cg = _array_diagonal(_array_tensor_product(M, N, P), (4, 1), (2, 0)) + assert cg == _array_diagonal(_array_tensor_product(M, N, P), (1, 4), (0, 2)) + + cg = _array_diagonal(_array_tensor_product(M, N), (1, 2), (3,), allow_trivial_diags=True) + assert cg == _permute_dims(_array_diagonal(_array_tensor_product(M, N), (1, 2)), [0, 2, 1]) + + Ax = ArraySymbol("Ax", shape=(1, 2, 3, 4, 3, 5, 6, 2, 7)) + cg = _array_diagonal(Ax, (1, 7), (3,), (2, 4), (6,), allow_trivial_diags=True) + assert cg == _permute_dims(_array_diagonal(Ax, (1, 7), (2, 4)), [0, 2, 4, 5, 1, 6, 3]) + + cg = _array_diagonal(M, (0,), allow_trivial_diags=True) + assert cg == _permute_dims(M, [1, 0]) + + raises(ValueError, lambda: _array_diagonal(M, (0, 0))) + + +def test_arrayexpr_array_shape(): + expr = _array_tensor_product(M, N, P, Q) + assert expr.shape == (k, k, k, k, k, k, k, k) + Z = MatrixSymbol("Z", m, n) + expr = _array_tensor_product(M, Z) + assert expr.shape == (k, k, m, n) + expr2 = _array_contraction(expr, (0, 1)) + assert expr2.shape == (m, n) + expr2 = _array_diagonal(expr, (0, 1)) + assert expr2.shape == (m, n, k) + exprp = _permute_dims(expr, [2, 1, 3, 0]) + assert exprp.shape == (m, k, n, k) + expr3 = _array_tensor_product(N, Z) + expr2 = _array_add(expr, expr3) + assert expr2.shape == (k, k, m, n) + + # Contraction along axes with discordant dimensions: + raises(ValueError, lambda: _array_contraction(expr, (1, 2))) + # Also diagonal needs the same dimensions: + raises(ValueError, lambda: _array_diagonal(expr, (1, 2))) + # Diagonal requires at least to axes to compute the diagonal: + raises(ValueError, lambda: _array_diagonal(expr, (1,))) + + +def test_arrayexpr_permutedims_sink(): + + cg = _permute_dims(_array_tensor_product(M, N), [0, 1, 3, 2], nest_permutation=False) + sunk = nest_permutation(cg) + assert sunk == _array_tensor_product(M, _permute_dims(N, [1, 0])) + + cg = _permute_dims(_array_tensor_product(M, N), [1, 0, 3, 2], nest_permutation=False) + sunk = nest_permutation(cg) + assert sunk == _array_tensor_product(_permute_dims(M, [1, 0]), _permute_dims(N, [1, 0])) + + cg = _permute_dims(_array_tensor_product(M, N), [3, 2, 1, 0], nest_permutation=False) + sunk = nest_permutation(cg) + assert sunk == _array_tensor_product(_permute_dims(N, [1, 0]), _permute_dims(M, [1, 0])) + + cg = _permute_dims(_array_contraction(_array_tensor_product(M, N), (1, 2)), [1, 0], nest_permutation=False) + sunk = nest_permutation(cg) + assert sunk == _array_contraction(_permute_dims(_array_tensor_product(M, N), [[0, 3]]), (1, 2)) + + cg = _permute_dims(_array_tensor_product(M, N), [1, 0, 3, 2], nest_permutation=False) + sunk = nest_permutation(cg) + assert sunk == _array_tensor_product(_permute_dims(M, [1, 0]), _permute_dims(N, [1, 0])) + + cg = _permute_dims(_array_contraction(_array_tensor_product(M, N, P), (1, 2), (3, 4)), [1, 0], nest_permutation=False) + sunk = nest_permutation(cg) + assert sunk == _array_contraction(_permute_dims(_array_tensor_product(M, N, P), [[0, 5]]), (1, 2), (3, 4)) + + +def test_arrayexpr_push_indices_up_and_down(): + + indices = list(range(12)) + + contr_diag_indices = [(0, 6), (2, 8)] + assert ArrayContraction._push_indices_down(contr_diag_indices, indices) == (1, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, 15) + assert ArrayContraction._push_indices_up(contr_diag_indices, indices) == (None, 0, None, 1, 2, 3, None, 4, None, 5, 6, 7) + + assert ArrayDiagonal._push_indices_down(contr_diag_indices, indices, 10) == (1, 3, 4, 5, 7, 9, (0, 6), (2, 8), None, None, None, None) + assert ArrayDiagonal._push_indices_up(contr_diag_indices, indices, 10) == (6, 0, 7, 1, 2, 3, 6, 4, 7, 5, None, None) + + contr_diag_indices = [(1, 2), (7, 8)] + assert ArrayContraction._push_indices_down(contr_diag_indices, indices) == (0, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 15) + assert ArrayContraction._push_indices_up(contr_diag_indices, indices) == (0, None, None, 1, 2, 3, 4, None, None, 5, 6, 7) + + assert ArrayDiagonal._push_indices_down(contr_diag_indices, indices, 10) == (0, 3, 4, 5, 6, 9, (1, 2), (7, 8), None, None, None, None) + assert ArrayDiagonal._push_indices_up(contr_diag_indices, indices, 10) == (0, 6, 6, 1, 2, 3, 4, 7, 7, 5, None, None) + + +def test_arrayexpr_split_multiple_contractions(): + a = MatrixSymbol("a", k, 1) + b = MatrixSymbol("b", k, 1) + A = MatrixSymbol("A", k, k) + B = MatrixSymbol("B", k, k) + C = MatrixSymbol("C", k, k) + X = MatrixSymbol("X", k, k) + + cg = _array_contraction(_array_tensor_product(A.T, a, b, b.T, (A*X*b).applyfunc(cos)), (1, 2, 8), (5, 6, 9)) + expected = _array_contraction(_array_tensor_product(A.T, DiagMatrix(a), OneArray(1), b, b.T, (A*X*b).applyfunc(cos)), (1, 3), (2, 9), (6, 7, 10)) + assert cg.split_multiple_contractions().dummy_eq(expected) + + # Check no overlap of lines: + + cg = _array_contraction(_array_tensor_product(A, a, C, a, B), (1, 2, 4), (5, 6, 8), (3, 7)) + assert cg.split_multiple_contractions() == cg + + cg = _array_contraction(_array_tensor_product(a, b, A), (0, 2, 4), (1, 3)) + assert cg.split_multiple_contractions() == cg + + +def test_arrayexpr_nested_permutations(): + + cg = _permute_dims(_permute_dims(M, (1, 0)), (1, 0)) + assert cg == M + + times = 3 + plist1 = [list(range(6)) for i in range(times)] + plist2 = [list(range(6)) for i in range(times)] + + for i in range(times): + random.shuffle(plist1[i]) + random.shuffle(plist2[i]) + + plist1.append([2, 5, 4, 1, 0, 3]) + plist2.append([3, 5, 0, 4, 1, 2]) + + plist1.append([2, 5, 4, 0, 3, 1]) + plist2.append([3, 0, 5, 1, 2, 4]) + + plist1.append([5, 4, 2, 0, 3, 1]) + plist2.append([4, 5, 0, 2, 3, 1]) + + Me = M.subs(k, 3).as_explicit() + Ne = N.subs(k, 3).as_explicit() + Pe = P.subs(k, 3).as_explicit() + cge = tensorproduct(Me, Ne, Pe) + + for permutation_array1, permutation_array2 in zip(plist1, plist2): + p1 = Permutation(permutation_array1) + p2 = Permutation(permutation_array2) + + cg = _permute_dims( + _permute_dims( + _array_tensor_product(M, N, P), + p1), + p2 + ) + result = _permute_dims( + _array_tensor_product(M, N, P), + p2*p1 + ) + assert cg == result + + # Check that `permutedims` behaves the same way with explicit-component arrays: + result1 = _permute_dims(_permute_dims(cge, p1), p2) + result2 = _permute_dims(cge, p2*p1) + assert result1 == result2 + + +def test_arrayexpr_contraction_permutation_mix(): + + Me = M.subs(k, 3).as_explicit() + Ne = N.subs(k, 3).as_explicit() + + cg1 = _array_contraction(PermuteDims(_array_tensor_product(M, N), Permutation([0, 2, 1, 3])), (2, 3)) + cg2 = _array_contraction(_array_tensor_product(M, N), (1, 3)) + assert cg1 == cg2 + cge1 = tensorcontraction(permutedims(tensorproduct(Me, Ne), Permutation([0, 2, 1, 3])), (2, 3)) + cge2 = tensorcontraction(tensorproduct(Me, Ne), (1, 3)) + assert cge1 == cge2 + + cg1 = _permute_dims(_array_tensor_product(M, N), Permutation([0, 1, 3, 2])) + cg2 = _array_tensor_product(M, _permute_dims(N, Permutation([1, 0]))) + assert cg1 == cg2 + + cg1 = _array_contraction( + _permute_dims( + _array_tensor_product(M, N, P, Q), Permutation([0, 2, 3, 1, 4, 5, 7, 6])), + (1, 2), (3, 5) + ) + cg2 = _array_contraction( + _array_tensor_product(M, N, P, _permute_dims(Q, Permutation([1, 0]))), + (1, 5), (2, 3) + ) + assert cg1 == cg2 + + cg1 = _array_contraction( + _permute_dims( + _array_tensor_product(M, N, P, Q), Permutation([1, 0, 4, 6, 2, 7, 5, 3])), + (0, 1), (2, 6), (3, 7) + ) + cg2 = _permute_dims( + _array_contraction( + _array_tensor_product(M, P, Q, N), + (0, 1), (2, 3), (4, 7)), + [1, 0] + ) + assert cg1 == cg2 + + cg1 = _array_contraction( + _permute_dims( + _array_tensor_product(M, N, P, Q), Permutation([1, 0, 4, 6, 7, 2, 5, 3])), + (0, 1), (2, 6), (3, 7) + ) + cg2 = _permute_dims( + _array_contraction( + _array_tensor_product(_permute_dims(M, [1, 0]), N, P, Q), + (0, 1), (3, 6), (4, 5) + ), + Permutation([1, 0]) + ) + assert cg1 == cg2 + + +def test_arrayexpr_permute_tensor_product(): + cg1 = _permute_dims(_array_tensor_product(M, N, P, Q), Permutation([2, 3, 1, 0, 5, 4, 6, 7])) + cg2 = _array_tensor_product(N, _permute_dims(M, [1, 0]), + _permute_dims(P, [1, 0]), Q) + assert cg1 == cg2 + + # TODO: reverse operation starting with `PermuteDims` and getting down to `bb`... + cg1 = _permute_dims(_array_tensor_product(M, N, P, Q), Permutation([2, 3, 4, 5, 0, 1, 6, 7])) + cg2 = _array_tensor_product(N, P, M, Q) + assert cg1 == cg2 + + cg1 = _permute_dims(_array_tensor_product(M, N, P, Q), Permutation([2, 3, 4, 6, 5, 7, 0, 1])) + assert cg1.expr == _array_tensor_product(N, P, Q, M) + assert cg1.permutation == Permutation([0, 1, 2, 4, 3, 5, 6, 7]) + + cg1 = _array_contraction( + _permute_dims( + _array_tensor_product(N, Q, Q, M), + [2, 1, 5, 4, 0, 3, 6, 7]), + [1, 2, 6]) + cg2 = _permute_dims(_array_contraction(_array_tensor_product(Q, Q, N, M), (3, 5, 6)), [0, 2, 3, 1, 4]) + assert cg1 == cg2 + + cg1 = _array_contraction( + _array_contraction( + _array_contraction( + _array_contraction( + _permute_dims( + _array_tensor_product(N, Q, Q, M), + [2, 1, 5, 4, 0, 3, 6, 7]), + [1, 2, 6]), + [1, 3, 4]), + [1]), + [0]) + cg2 = _array_contraction(_array_tensor_product(M, N, Q, Q), (0, 3, 5), (1, 4, 7), (2,), (6,)) + assert cg1 == cg2 + + +def test_arrayexpr_canonicalize_diagonal__permute_dims(): + tp = _array_tensor_product(M, Q, N, P) + expr = _array_diagonal( + _permute_dims(tp, [0, 1, 2, 4, 7, 6, 3, 5]), (2, 4, 5), (6, 7), + (0, 3)) + result = _array_diagonal(tp, (2, 6, 7), (3, 5), (0, 4)) + assert expr == result + + tp = _array_tensor_product(M, N, P, Q) + expr = _array_diagonal(_permute_dims(tp, [0, 5, 2, 4, 1, 6, 3, 7]), (1, 2, 6), (3, 4)) + result = _array_diagonal(_array_tensor_product(M, P, N, Q), (3, 4, 5), (1, 2)) + assert expr == result + + +def test_arrayexpr_canonicalize_diagonal_contraction(): + tp = _array_tensor_product(M, N, P, Q) + expr = _array_contraction(_array_diagonal(tp, (1, 3, 4)), (0, 3)) + result = _array_diagonal(_array_contraction(_array_tensor_product(M, N, P, Q), (0, 6)), (0, 2, 3)) + assert expr == result + + expr = _array_contraction(_array_diagonal(tp, (0, 1, 2, 3, 7)), (1, 2, 3)) + result = _array_contraction(_array_tensor_product(M, N, P, Q), (0, 1, 2, 3, 5, 6, 7)) + assert expr == result + + expr = _array_contraction(_array_diagonal(tp, (0, 2, 6, 7)), (1, 2, 3)) + result = _array_diagonal(_array_contraction(tp, (3, 4, 5)), (0, 2, 3, 4)) + assert expr == result + + td = _array_diagonal(_array_tensor_product(M, N, P, Q), (0, 3)) + expr = _array_contraction(td, (2, 1), (0, 4, 6, 5, 3)) + result = _array_contraction(_array_tensor_product(M, N, P, Q), (0, 1, 3, 5, 6, 7), (2, 4)) + assert expr == result + + +def test_arrayexpr_array_wrong_permutation_size(): + cg = _array_tensor_product(M, N) + raises(ValueError, lambda: _permute_dims(cg, [1, 0])) + raises(ValueError, lambda: _permute_dims(cg, [1, 0, 2, 3, 5, 4])) + + +def test_arrayexpr_nested_array_elementwise_add(): + cg = _array_contraction(_array_add( + _array_tensor_product(M, N), + _array_tensor_product(N, M) + ), (1, 2)) + result = _array_add( + _array_contraction(_array_tensor_product(M, N), (1, 2)), + _array_contraction(_array_tensor_product(N, M), (1, 2)) + ) + assert cg == result + + cg = _array_diagonal(_array_add( + _array_tensor_product(M, N), + _array_tensor_product(N, M) + ), (1, 2)) + result = _array_add( + _array_diagonal(_array_tensor_product(M, N), (1, 2)), + _array_diagonal(_array_tensor_product(N, M), (1, 2)) + ) + assert cg == result + + +def test_arrayexpr_array_expr_zero_array(): + za1 = ZeroArray(k, l, m, n) + zm1 = ZeroMatrix(m, n) + + za2 = ZeroArray(k, m, m, n) + zm2 = ZeroMatrix(m, m) + zm3 = ZeroMatrix(k, k) + + assert _array_tensor_product(M, N, za1) == ZeroArray(k, k, k, k, k, l, m, n) + assert _array_tensor_product(M, N, zm1) == ZeroArray(k, k, k, k, m, n) + + assert _array_contraction(za1, (3,)) == ZeroArray(k, l, m) + assert _array_contraction(zm1, (1,)) == ZeroArray(m) + assert _array_contraction(za2, (1, 2)) == ZeroArray(k, n) + assert _array_contraction(zm2, (0, 1)) == 0 + + assert _array_diagonal(za2, (1, 2)) == ZeroArray(k, n, m) + assert _array_diagonal(zm2, (0, 1)) == ZeroArray(m) + + assert _permute_dims(za1, [2, 1, 3, 0]) == ZeroArray(m, l, n, k) + assert _permute_dims(zm1, [1, 0]) == ZeroArray(n, m) + + assert _array_add(za1) == za1 + assert _array_add(zm1) == ZeroArray(m, n) + tp1 = _array_tensor_product(MatrixSymbol("A", k, l), MatrixSymbol("B", m, n)) + assert _array_add(tp1, za1) == tp1 + tp2 = _array_tensor_product(MatrixSymbol("C", k, l), MatrixSymbol("D", m, n)) + assert _array_add(tp1, za1, tp2) == _array_add(tp1, tp2) + assert _array_add(M, zm3) == M + assert _array_add(M, N, zm3) == _array_add(M, N) + + +def test_arrayexpr_array_expr_applyfunc(): + + A = ArraySymbol("A", (3, k, 2)) + aaf = ArrayElementwiseApplyFunc(sin, A) + assert aaf.shape == (3, k, 2) + + +def test_edit_array_contraction(): + cg = _array_contraction(_array_tensor_product(A, B, C, D), (1, 2, 5)) + ecg = _EditArrayContraction(cg) + assert ecg.to_array_contraction() == cg + + ecg.args_with_ind[1], ecg.args_with_ind[2] = ecg.args_with_ind[2], ecg.args_with_ind[1] + assert ecg.to_array_contraction() == _array_contraction(_array_tensor_product(A, C, B, D), (1, 3, 4)) + + ci = ecg.get_new_contraction_index() + new_arg = _ArgE(X) + new_arg.indices = [ci, ci] + ecg.args_with_ind.insert(2, new_arg) + assert ecg.to_array_contraction() == _array_contraction(_array_tensor_product(A, C, X, B, D), (1, 3, 6), (4, 5)) + + assert ecg.get_contraction_indices() == [[1, 3, 6], [4, 5]] + assert [[tuple(j) for j in i] for i in ecg.get_contraction_indices_to_ind_rel_pos()] == [[(0, 1), (1, 1), (3, 0)], [(2, 0), (2, 1)]] + assert [list(i) for i in ecg.get_mapping_for_index(0)] == [[0, 1], [1, 1], [3, 0]] + assert [list(i) for i in ecg.get_mapping_for_index(1)] == [[2, 0], [2, 1]] + raises(ValueError, lambda: ecg.get_mapping_for_index(2)) + + ecg.args_with_ind.pop(1) + assert ecg.to_array_contraction() == _array_contraction(_array_tensor_product(A, X, B, D), (1, 4), (2, 3)) + + ecg.args_with_ind[0].indices[1] = ecg.args_with_ind[1].indices[0] + ecg.args_with_ind[1].indices[1] = ecg.args_with_ind[2].indices[0] + assert ecg.to_array_contraction() == _array_contraction(_array_tensor_product(A, X, B, D), (1, 2), (3, 4)) + + ecg.insert_after(ecg.args_with_ind[1], _ArgE(C)) + assert ecg.to_array_contraction() == _array_contraction(_array_tensor_product(A, X, C, B, D), (1, 2), (3, 6)) + + +def test_array_expressions_no_canonicalization(): + + tp = _array_tensor_product(M, N, P) + + # ArrayTensorProduct: + + expr = ArrayTensorProduct(tp, N) + assert str(expr) == "ArrayTensorProduct(ArrayTensorProduct(M, N, P), N)" + assert expr.doit() == ArrayTensorProduct(M, N, P, N) + + expr = ArrayTensorProduct(ArrayContraction(M, (0, 1)), N) + assert str(expr) == "ArrayTensorProduct(ArrayContraction(M, (0, 1)), N)" + assert expr.doit() == ArrayContraction(ArrayTensorProduct(M, N), (0, 1)) + + expr = ArrayTensorProduct(ArrayDiagonal(M, (0, 1)), N) + assert str(expr) == "ArrayTensorProduct(ArrayDiagonal(M, (0, 1)), N)" + assert expr.doit() == PermuteDims(ArrayDiagonal(ArrayTensorProduct(M, N), (0, 1)), [2, 0, 1]) + + expr = ArrayTensorProduct(PermuteDims(M, [1, 0]), N) + assert str(expr) == "ArrayTensorProduct(PermuteDims(M, (0 1)), N)" + assert expr.doit() == PermuteDims(ArrayTensorProduct(M, N), [1, 0, 2, 3]) + + # ArrayContraction: + + expr = ArrayContraction(_array_contraction(tp, (0, 2)), (0, 1)) + assert isinstance(expr, ArrayContraction) + assert isinstance(expr.expr, ArrayContraction) + assert str(expr) == "ArrayContraction(ArrayContraction(ArrayTensorProduct(M, N, P), (0, 2)), (0, 1))" + assert expr.doit() == ArrayContraction(tp, (0, 2), (1, 3)) + + expr = ArrayContraction(ArrayContraction(ArrayContraction(tp, (0, 1)), (0, 1)), (0, 1)) + assert expr.doit() == ArrayContraction(tp, (0, 1), (2, 3), (4, 5)) + # assert expr._canonicalize() == ArrayContraction(ArrayContraction(tp, (0, 1)), (0, 1), (2, 3)) + + expr = ArrayContraction(ArrayDiagonal(tp, (0, 1)), (0, 1)) + assert str(expr) == "ArrayContraction(ArrayDiagonal(ArrayTensorProduct(M, N, P), (0, 1)), (0, 1))" + assert expr.doit() == ArrayDiagonal(ArrayContraction(ArrayTensorProduct(N, M, P), (0, 1)), (0, 1)) + + expr = ArrayContraction(PermuteDims(M, [1, 0]), (0, 1)) + assert str(expr) == "ArrayContraction(PermuteDims(M, (0 1)), (0, 1))" + assert expr.doit() == ArrayContraction(M, (0, 1)) + + # ArrayDiagonal: + + expr = ArrayDiagonal(ArrayDiagonal(tp, (0, 2)), (0, 1)) + assert str(expr) == "ArrayDiagonal(ArrayDiagonal(ArrayTensorProduct(M, N, P), (0, 2)), (0, 1))" + assert expr.doit() == ArrayDiagonal(tp, (0, 2), (1, 3)) + + expr = ArrayDiagonal(ArrayDiagonal(ArrayDiagonal(tp, (0, 1)), (0, 1)), (0, 1)) + assert expr.doit() == ArrayDiagonal(tp, (0, 1), (2, 3), (4, 5)) + assert expr._canonicalize() == expr.doit() + + expr = ArrayDiagonal(ArrayContraction(tp, (0, 1)), (0, 1)) + assert str(expr) == "ArrayDiagonal(ArrayContraction(ArrayTensorProduct(M, N, P), (0, 1)), (0, 1))" + assert expr.doit() == expr + + expr = ArrayDiagonal(PermuteDims(M, [1, 0]), (0, 1)) + assert str(expr) == "ArrayDiagonal(PermuteDims(M, (0 1)), (0, 1))" + assert expr.doit() == ArrayDiagonal(M, (0, 1)) + + # ArrayAdd: + + expr = ArrayAdd(M) + assert isinstance(expr, ArrayAdd) + assert expr.doit() == M + + expr = ArrayAdd(ArrayAdd(M, N), P) + assert str(expr) == "ArrayAdd(ArrayAdd(M, N), P)" + assert expr.doit() == ArrayAdd(M, N, P) + + expr = ArrayAdd(M, ArrayAdd(N, ArrayAdd(P, M))) + assert expr.doit() == ArrayAdd(M, N, P, M) + assert expr._canonicalize() == ArrayAdd(M, N, ArrayAdd(P, M)) + + expr = ArrayAdd(M, ZeroArray(k, k), N) + assert str(expr) == "ArrayAdd(M, ZeroArray(k, k), N)" + assert expr.doit() == ArrayAdd(M, N) + + # PermuteDims: + + expr = PermuteDims(PermuteDims(M, [1, 0]), [1, 0]) + assert str(expr) == "PermuteDims(PermuteDims(M, (0 1)), (0 1))" + assert expr.doit() == M + + expr = PermuteDims(PermuteDims(PermuteDims(M, [1, 0]), [1, 0]), [1, 0]) + assert expr.doit() == PermuteDims(M, [1, 0]) + assert expr._canonicalize() == expr.doit() + + # Reshape + + expr = Reshape(A, (k**2,)) + assert expr.shape == (k**2,) + assert isinstance(expr, Reshape) + + +def test_array_expr_construction_with_functions(): + + tp = tensorproduct(M, N) + assert tp == ArrayTensorProduct(M, N) + + expr = tensorproduct(A, eye(2)) + assert expr == ArrayTensorProduct(A, eye(2)) + + # Contraction: + + expr = tensorcontraction(M, (0, 1)) + assert expr == ArrayContraction(M, (0, 1)) + + expr = tensorcontraction(tp, (1, 2)) + assert expr == ArrayContraction(tp, (1, 2)) + + expr = tensorcontraction(tensorcontraction(tp, (1, 2)), (0, 1)) + assert expr == ArrayContraction(tp, (0, 3), (1, 2)) + + # Diagonalization: + + expr = tensordiagonal(M, (0, 1)) + assert expr == ArrayDiagonal(M, (0, 1)) + + expr = tensordiagonal(tensordiagonal(tp, (0, 1)), (0, 1)) + assert expr == ArrayDiagonal(tp, (0, 1), (2, 3)) + + # Permutation of dimensions: + + expr = permutedims(M, [1, 0]) + assert expr == PermuteDims(M, [1, 0]) + + expr = permutedims(PermuteDims(tp, [1, 0, 2, 3]), [0, 1, 3, 2]) + assert expr == PermuteDims(tp, [1, 0, 3, 2]) + + expr = PermuteDims(tp, index_order_new=["a", "b", "c", "d"], index_order_old=["d", "c", "b", "a"]) + assert expr == PermuteDims(tp, [3, 2, 1, 0]) + + arr = Array(range(32)).reshape(2, 2, 2, 2, 2) + expr = PermuteDims(arr, index_order_new=["a", "b", "c", "d", "e"], index_order_old=['b', 'e', 'a', 'd', 'c']) + assert expr == PermuteDims(arr, [2, 0, 4, 3, 1]) + assert expr.as_explicit() == permutedims(arr, index_order_new=["a", "b", "c", "d", "e"], index_order_old=['b', 'e', 'a', 'd', 'c']) + + +def test_array_element_expressions(): + # Check commutative property: + assert M[0, 0]*N[0, 0] == N[0, 0]*M[0, 0] + + # Check derivatives: + assert M[0, 0].diff(M[0, 0]) == 1 + assert M[0, 0].diff(M[1, 0]) == 0 + assert M[0, 0].diff(N[0, 0]) == 0 + assert M[0, 1].diff(M[i, j]) == KroneckerDelta(i, 0)*KroneckerDelta(j, 1) + assert M[0, 1].diff(N[i, j]) == 0 + + K4 = ArraySymbol("K4", shape=(k, k, k, k)) + + assert K4[i, j, k, l].diff(K4[1, 2, 3, 4]) == ( + KroneckerDelta(i, 1)*KroneckerDelta(j, 2)*KroneckerDelta(k, 3)*KroneckerDelta(l, 4) + ) + + +def test_array_expr_reshape(): + + A = MatrixSymbol("A", 2, 2) + B = ArraySymbol("B", (2, 2, 2)) + C = Array([1, 2, 3, 4]) + + expr = Reshape(A, (4,)) + assert expr.expr == A + assert expr.shape == (4,) + assert expr.as_explicit() == Array([A[0, 0], A[0, 1], A[1, 0], A[1, 1]]) + + expr = Reshape(B, (2, 4)) + assert expr.expr == B + assert expr.shape == (2, 4) + ee = expr.as_explicit() + assert isinstance(ee, ImmutableDenseNDimArray) + assert ee.shape == (2, 4) + assert ee == Array([[B[0, 0, 0], B[0, 0, 1], B[0, 1, 0], B[0, 1, 1]], [B[1, 0, 0], B[1, 0, 1], B[1, 1, 0], B[1, 1, 1]]]) + + expr = Reshape(A, (k, 2)) + assert expr.shape == (k, 2) + + raises(ValueError, lambda: Reshape(A, (2, 3))) + raises(ValueError, lambda: Reshape(A, (3,))) + + expr = Reshape(C, (2, 2)) + assert expr.expr == C + assert expr.shape == (2, 2) + assert expr.doit() == Array([[1, 2], [3, 4]]) + + +def test_array_expr_as_explicit_with_explicit_component_arrays(): + # Test if .as_explicit() works with explicit-component arrays + # nested in array expressions: + from sympy.abc import x, y, z, t + A = Array([[x, y], [z, t]]) + assert ArrayTensorProduct(A, A).as_explicit() == tensorproduct(A, A) + assert ArrayDiagonal(A, (0, 1)).as_explicit() == tensordiagonal(A, (0, 1)) + assert ArrayContraction(A, (0, 1)).as_explicit() == tensorcontraction(A, (0, 1)) + assert ArrayAdd(A, A).as_explicit() == A + A + assert ArrayElementwiseApplyFunc(sin, A).as_explicit() == A.applyfunc(sin) + assert PermuteDims(A, [1, 0]).as_explicit() == permutedims(A, [1, 0]) + assert Reshape(A, [4]).as_explicit() == A.reshape(4) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_arrayexpr_derivatives.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_arrayexpr_derivatives.py new file mode 100644 index 0000000000000000000000000000000000000000..bc0fcf63f2607b23feb38758e4f0994de4f0384b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_arrayexpr_derivatives.py @@ -0,0 +1,78 @@ +from sympy.core.symbol import symbols +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.special import Identity +from sympy.matrices.expressions.applyfunc import ElementwiseApplyFunction +from sympy.tensor.array.expressions.array_expressions import ArraySymbol, ArrayTensorProduct, \ + PermuteDims, ArrayDiagonal, ArrayElementwiseApplyFunc, ArrayContraction, _permute_dims, Reshape +from sympy.tensor.array.expressions.arrayexpr_derivatives import array_derive + +k = symbols("k") + +I = Identity(k) +X = MatrixSymbol("X", k, k) +x = MatrixSymbol("x", k, 1) + +A = MatrixSymbol("A", k, k) +B = MatrixSymbol("B", k, k) +C = MatrixSymbol("C", k, k) +D = MatrixSymbol("D", k, k) + +A1 = ArraySymbol("A", (3, 2, k)) + + +def test_arrayexpr_derivatives1(): + + res = array_derive(X, X) + assert res == PermuteDims(ArrayTensorProduct(I, I), [0, 2, 1, 3]) + + cg = ArrayTensorProduct(A, X, B) + res = array_derive(cg, X) + assert res == _permute_dims( + ArrayTensorProduct(I, A, I, B), + [0, 4, 2, 3, 1, 5, 6, 7]) + + cg = ArrayContraction(X, (0, 1)) + res = array_derive(cg, X) + assert res == ArrayContraction(ArrayTensorProduct(I, I), (1, 3)) + + cg = ArrayDiagonal(X, (0, 1)) + res = array_derive(cg, X) + assert res == ArrayDiagonal(ArrayTensorProduct(I, I), (1, 3)) + + cg = ElementwiseApplyFunction(sin, X) + res = array_derive(cg, X) + assert res.dummy_eq(ArrayDiagonal( + ArrayTensorProduct( + ElementwiseApplyFunction(cos, X), + I, + I + ), (0, 3), (1, 5))) + + cg = ArrayElementwiseApplyFunc(sin, X) + res = array_derive(cg, X) + assert res.dummy_eq(ArrayDiagonal( + ArrayTensorProduct( + I, + I, + ArrayElementwiseApplyFunc(cos, X) + ), (1, 4), (3, 5))) + + res = array_derive(A1, A1) + assert res == PermuteDims( + ArrayTensorProduct(Identity(3), Identity(2), Identity(k)), + [0, 2, 4, 1, 3, 5] + ) + + cg = ArrayElementwiseApplyFunc(sin, A1) + res = array_derive(cg, A1) + assert res.dummy_eq(ArrayDiagonal( + ArrayTensorProduct( + Identity(3), Identity(2), Identity(k), + ArrayElementwiseApplyFunc(cos, A1) + ), (1, 6), (3, 7), (5, 8) + )) + + cg = Reshape(A, (k**2,)) + res = array_derive(cg, A) + assert res == Reshape(PermuteDims(ArrayTensorProduct(I, I), [0, 2, 1, 3]), (k, k, k**2)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_as_explicit.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_as_explicit.py new file mode 100644 index 0000000000000000000000000000000000000000..30cc61b1ee651ca032e165cd67926fa33c71354f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_as_explicit.py @@ -0,0 +1,63 @@ +from sympy.core.symbol import Symbol +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.tensor.array.arrayop import (permutedims, tensorcontraction, tensordiagonal, tensorproduct) +from sympy.tensor.array.dense_ndim_array import ImmutableDenseNDimArray +from sympy.tensor.array.expressions.array_expressions import ZeroArray, OneArray, ArraySymbol, \ + ArrayTensorProduct, PermuteDims, ArrayDiagonal, ArrayContraction, ArrayAdd +from sympy.testing.pytest import raises + + +def test_array_as_explicit_call(): + + assert ZeroArray(3, 2, 4).as_explicit() == ImmutableDenseNDimArray.zeros(3, 2, 4) + assert OneArray(3, 2, 4).as_explicit() == ImmutableDenseNDimArray([1 for i in range(3*2*4)]).reshape(3, 2, 4) + + k = Symbol("k") + X = ArraySymbol("X", (k, 3, 2)) + raises(ValueError, lambda: X.as_explicit()) + raises(ValueError, lambda: ZeroArray(k, 2, 3).as_explicit()) + raises(ValueError, lambda: OneArray(2, k, 2).as_explicit()) + + A = ArraySymbol("A", (3, 3)) + B = ArraySymbol("B", (3, 3)) + + texpr = tensorproduct(A, B) + assert isinstance(texpr, ArrayTensorProduct) + assert texpr.as_explicit() == tensorproduct(A.as_explicit(), B.as_explicit()) + + texpr = tensorcontraction(A, (0, 1)) + assert isinstance(texpr, ArrayContraction) + assert texpr.as_explicit() == A[0, 0] + A[1, 1] + A[2, 2] + + texpr = tensordiagonal(A, (0, 1)) + assert isinstance(texpr, ArrayDiagonal) + assert texpr.as_explicit() == ImmutableDenseNDimArray([A[0, 0], A[1, 1], A[2, 2]]) + + texpr = permutedims(A, [1, 0]) + assert isinstance(texpr, PermuteDims) + assert texpr.as_explicit() == permutedims(A.as_explicit(), [1, 0]) + + +def test_array_as_explicit_matrix_symbol(): + + A = MatrixSymbol("A", 3, 3) + B = MatrixSymbol("B", 3, 3) + + texpr = tensorproduct(A, B) + assert isinstance(texpr, ArrayTensorProduct) + assert texpr.as_explicit() == tensorproduct(A.as_explicit(), B.as_explicit()) + + texpr = tensorcontraction(A, (0, 1)) + assert isinstance(texpr, ArrayContraction) + assert texpr.as_explicit() == A[0, 0] + A[1, 1] + A[2, 2] + + texpr = tensordiagonal(A, (0, 1)) + assert isinstance(texpr, ArrayDiagonal) + assert texpr.as_explicit() == ImmutableDenseNDimArray([A[0, 0], A[1, 1], A[2, 2]]) + + texpr = permutedims(A, [1, 0]) + assert isinstance(texpr, PermuteDims) + assert texpr.as_explicit() == permutedims(A.as_explicit(), [1, 0]) + + expr = ArrayAdd(ArrayTensorProduct(A, B), ArrayTensorProduct(B, A)) + assert expr.as_explicit() == expr.args[0].as_explicit() + expr.args[1].as_explicit() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_array_to_indexed.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_array_to_indexed.py new file mode 100644 index 0000000000000000000000000000000000000000..a6b713fbec94ab7808c5a8a778b3313402d9d0c7 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_array_to_indexed.py @@ -0,0 +1,61 @@ +from sympy import Sum, Dummy, sin +from sympy.tensor.array.expressions import ArraySymbol, ArrayTensorProduct, ArrayContraction, PermuteDims, \ + ArrayDiagonal, ArrayAdd, OneArray, ZeroArray, convert_indexed_to_array, ArrayElementwiseApplyFunc, Reshape +from sympy.tensor.array.expressions.from_array_to_indexed import convert_array_to_indexed + +from sympy.abc import i, j, k, l, m, n, o + + +def test_convert_array_to_indexed_main(): + A = ArraySymbol("A", (3, 3, 3)) + B = ArraySymbol("B", (3, 3)) + C = ArraySymbol("C", (3, 3)) + + d_ = Dummy("d_") + + assert convert_array_to_indexed(A, [i, j, k]) == A[i, j, k] + + expr = ArrayTensorProduct(A, B, C) + conv = convert_array_to_indexed(expr, [i,j,k,l,m,n,o]) + assert conv == A[i,j,k]*B[l,m]*C[n,o] + assert convert_indexed_to_array(conv, [i,j,k,l,m,n,o]) == expr + + expr = ArrayContraction(A, (0, 2)) + assert convert_array_to_indexed(expr, [i]).dummy_eq(Sum(A[d_, i, d_], (d_, 0, 2))) + + expr = ArrayDiagonal(A, (0, 2)) + assert convert_array_to_indexed(expr, [i, j]) == A[j, i, j] + + expr = PermuteDims(A, [1, 2, 0]) + conv = convert_array_to_indexed(expr, [i, j, k]) + assert conv == A[k, i, j] + assert convert_indexed_to_array(conv, [i, j, k]) == expr + + expr = ArrayAdd(B, C, PermuteDims(C, [1, 0])) + conv = convert_array_to_indexed(expr, [i, j]) + assert conv == B[i, j] + C[i, j] + C[j, i] + assert convert_indexed_to_array(conv, [i, j]) == expr + + expr = ArrayElementwiseApplyFunc(sin, A) + conv = convert_array_to_indexed(expr, [i, j, k]) + assert conv == sin(A[i, j, k]) + assert convert_indexed_to_array(conv, [i, j, k]).dummy_eq(expr) + + assert convert_array_to_indexed(OneArray(3, 3), [i, j]) == 1 + assert convert_array_to_indexed(ZeroArray(3, 3), [i, j]) == 0 + + expr = Reshape(A, (27,)) + assert convert_array_to_indexed(expr, [i]) == A[i // 9, i // 3 % 3, i % 3] + + X = ArraySymbol("X", (2, 3, 4, 5, 6)) + expr = Reshape(X, (2*3*4*5*6,)) + assert convert_array_to_indexed(expr, [i]) == X[i // 360, i // 120 % 3, i // 30 % 4, i // 6 % 5, i % 6] + + expr = Reshape(X, (4, 9, 2, 2, 5)) + one_index = 180*i + 20*j + 10*k + 5*l + m + expected = X[one_index // (3*4*5*6), one_index // (4*5*6) % 3, one_index // (5*6) % 4, one_index // 6 % 5, one_index % 6] + assert convert_array_to_indexed(expr, [i, j, k, l, m]) == expected + + X = ArraySymbol("X", (2*3*5,)) + expr = Reshape(X, (2, 3, 5)) + assert convert_array_to_indexed(expr, [i, j, k]) == X[15*i + 5*j + k] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_array_to_matrix.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_array_to_matrix.py new file mode 100644 index 0000000000000000000000000000000000000000..26839d5e7cec0554948c6b726482f9d8ca250b1c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_array_to_matrix.py @@ -0,0 +1,689 @@ +from sympy import Lambda, S, Dummy, KroneckerProduct +from sympy.core.symbol import symbols +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.functions.elementary.trigonometric import cos, sin +from sympy.matrices.expressions.hadamard import HadamardProduct, HadamardPower +from sympy.matrices.expressions.special import (Identity, OneMatrix, ZeroMatrix) +from sympy.matrices.expressions.matexpr import MatrixElement +from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array +from sympy.tensor.array.expressions.from_array_to_matrix import _support_function_tp1_recognize, \ + _array_diag2contr_diagmatrix, convert_array_to_matrix, _remove_trivial_dims, _array2matrix, \ + _combine_removed, identify_removable_identity_matrices, _array_contraction_to_diagonal_multiple_identity +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.combinatorics import Permutation +from sympy.matrices.expressions.diagonal import DiagMatrix, DiagonalMatrix +from sympy.matrices import Trace, MatMul, Transpose +from sympy.tensor.array.expressions.array_expressions import ZeroArray, OneArray, \ + ArrayElement, ArraySymbol, ArrayElementwiseApplyFunc, _array_tensor_product, _array_contraction, \ + _array_diagonal, _permute_dims, PermuteDims, ArrayAdd, ArrayDiagonal, ArrayContraction, ArrayTensorProduct +from sympy.testing.pytest import raises + + +i, j, k, l, m, n = symbols("i j k l m n") + +I = Identity(k) +I1 = Identity(1) + +M = MatrixSymbol("M", k, k) +N = MatrixSymbol("N", k, k) +P = MatrixSymbol("P", k, k) +Q = MatrixSymbol("Q", k, k) + +A = MatrixSymbol("A", k, k) +B = MatrixSymbol("B", k, k) +C = MatrixSymbol("C", k, k) +D = MatrixSymbol("D", k, k) + +X = MatrixSymbol("X", k, k) +Y = MatrixSymbol("Y", k, k) + +a = MatrixSymbol("a", k, 1) +b = MatrixSymbol("b", k, 1) +c = MatrixSymbol("c", k, 1) +d = MatrixSymbol("d", k, 1) + +x = MatrixSymbol("x", k, 1) +y = MatrixSymbol("y", k, 1) + + +def test_arrayexpr_convert_array_to_matrix(): + + cg = _array_contraction(_array_tensor_product(M), (0, 1)) + assert convert_array_to_matrix(cg) == Trace(M) + + cg = _array_contraction(_array_tensor_product(M, N), (0, 1), (2, 3)) + assert convert_array_to_matrix(cg) == Trace(M) * Trace(N) + + cg = _array_contraction(_array_tensor_product(M, N), (0, 3), (1, 2)) + assert convert_array_to_matrix(cg) == Trace(M * N) + + cg = _array_contraction(_array_tensor_product(M, N), (0, 2), (1, 3)) + assert convert_array_to_matrix(cg) == Trace(M * N.T) + + cg = convert_matrix_to_array(M * N * P) + assert convert_array_to_matrix(cg) == M * N * P + + cg = convert_matrix_to_array(M * N.T * P) + assert convert_array_to_matrix(cg) == M * N.T * P + + cg = _array_contraction(_array_tensor_product(M,N,P,Q), (1, 2), (5, 6)) + assert convert_array_to_matrix(cg) == _array_tensor_product(M * N, P * Q) + + cg = _array_contraction(_array_tensor_product(-2, M, N), (1, 2)) + assert convert_array_to_matrix(cg) == -2 * M * N + + a = MatrixSymbol("a", k, 1) + b = MatrixSymbol("b", k, 1) + c = MatrixSymbol("c", k, 1) + cg = PermuteDims( + _array_contraction( + _array_tensor_product( + a, + ArrayAdd( + _array_tensor_product(b, c), + _array_tensor_product(c, b), + ) + ), (2, 4)), [0, 1, 3, 2]) + assert convert_array_to_matrix(cg) == a * (b.T * c + c.T * b) + + za = ZeroArray(m, n) + assert convert_array_to_matrix(za) == ZeroMatrix(m, n) + + cg = _array_tensor_product(3, M) + assert convert_array_to_matrix(cg) == 3 * M + + # Partial conversion to matrix multiplication: + expr = _array_contraction(_array_tensor_product(M, N, P, Q), (0, 2), (1, 4, 6)) + assert convert_array_to_matrix(expr) == _array_contraction(_array_tensor_product(M.T*N, P, Q), (0, 2, 4)) + + x = MatrixSymbol("x", k, 1) + cg = PermuteDims( + _array_contraction(_array_tensor_product(OneArray(1), x, OneArray(1), DiagMatrix(Identity(1))), + (0, 5)), Permutation(1, 2, 3)) + assert convert_array_to_matrix(cg) == x + + expr = ArrayAdd(M, PermuteDims(M, [1, 0])) + assert convert_array_to_matrix(expr) == M + Transpose(M) + + +def test_arrayexpr_convert_array_to_matrix2(): + cg = _array_contraction(_array_tensor_product(M, N), (1, 3)) + assert convert_array_to_matrix(cg) == M * N.T + + cg = PermuteDims(_array_tensor_product(M, N), Permutation([0, 1, 3, 2])) + assert convert_array_to_matrix(cg) == _array_tensor_product(M, N.T) + + cg = _array_tensor_product(M, PermuteDims(N, Permutation([1, 0]))) + assert convert_array_to_matrix(cg) == _array_tensor_product(M, N.T) + + cg = _array_contraction( + PermuteDims( + _array_tensor_product(M, N, P, Q), Permutation([0, 2, 3, 1, 4, 5, 7, 6])), + (1, 2), (3, 5) + ) + assert convert_array_to_matrix(cg) == _array_tensor_product(M * P.T * Trace(N), Q.T) + + cg = _array_contraction( + _array_tensor_product(M, N, P, PermuteDims(Q, Permutation([1, 0]))), + (1, 5), (2, 3) + ) + assert convert_array_to_matrix(cg) == _array_tensor_product(M * P.T * Trace(N), Q.T) + + cg = _array_tensor_product(M, PermuteDims(N, [1, 0])) + assert convert_array_to_matrix(cg) == _array_tensor_product(M, N.T) + + cg = _array_tensor_product(PermuteDims(M, [1, 0]), PermuteDims(N, [1, 0])) + assert convert_array_to_matrix(cg) == _array_tensor_product(M.T, N.T) + + cg = _array_tensor_product(PermuteDims(N, [1, 0]), PermuteDims(M, [1, 0])) + assert convert_array_to_matrix(cg) == _array_tensor_product(N.T, M.T) + + cg = _array_contraction(M, (0,), (1,)) + assert convert_array_to_matrix(cg) == OneMatrix(1, k)*M*OneMatrix(k, 1) + + cg = _array_contraction(x, (0,), (1,)) + assert convert_array_to_matrix(cg) == OneMatrix(1, k)*x + + Xm = MatrixSymbol("Xm", m, n) + cg = _array_contraction(Xm, (0,), (1,)) + assert convert_array_to_matrix(cg) == OneMatrix(1, m)*Xm*OneMatrix(n, 1) + + +def test_arrayexpr_convert_array_to_diagonalized_vector(): + + # Check matrix recognition over trivial dimensions: + + cg = _array_tensor_product(a, b) + assert convert_array_to_matrix(cg) == a * b.T + + cg = _array_tensor_product(I1, a, b) + assert convert_array_to_matrix(cg) == a * b.T + + # Recognize trace inside a tensor product: + + cg = _array_contraction(_array_tensor_product(A, B, C), (0, 3), (1, 2)) + assert convert_array_to_matrix(cg) == Trace(A * B) * C + + # Transform diagonal operator to contraction: + + cg = _array_diagonal(_array_tensor_product(A, a), (1, 2)) + assert _array_diag2contr_diagmatrix(cg) == _array_contraction(_array_tensor_product(A, OneArray(1), DiagMatrix(a)), (1, 3)) + assert convert_array_to_matrix(cg) == A * DiagMatrix(a) + + cg = _array_diagonal(_array_tensor_product(a, b), (0, 2)) + assert _array_diag2contr_diagmatrix(cg) == _permute_dims( + _array_contraction(_array_tensor_product(DiagMatrix(a), OneArray(1), b), (0, 3)), [1, 2, 0] + ) + assert convert_array_to_matrix(cg) == b.T * DiagMatrix(a) + + cg = _array_diagonal(_array_tensor_product(A, a), (0, 2)) + assert _array_diag2contr_diagmatrix(cg) == _array_contraction(_array_tensor_product(A, OneArray(1), DiagMatrix(a)), (0, 3)) + assert convert_array_to_matrix(cg) == A.T * DiagMatrix(a) + + cg = _array_diagonal(_array_tensor_product(I, x, I1), (0, 2), (3, 5)) + assert _array_diag2contr_diagmatrix(cg) == _array_contraction(_array_tensor_product(I, OneArray(1), I1, DiagMatrix(x)), (0, 5)) + assert convert_array_to_matrix(cg) == DiagMatrix(x) + + cg = _array_diagonal(_array_tensor_product(I, x, A, B), (1, 2), (5, 6)) + assert _array_diag2contr_diagmatrix(cg) == _array_diagonal(_array_contraction(_array_tensor_product(I, OneArray(1), A, B, DiagMatrix(x)), (1, 7)), (5, 6)) + # TODO: this is returning a wrong result: + # convert_array_to_matrix(cg) + + cg = _array_diagonal(_array_tensor_product(I1, a, b), (1, 3, 5)) + assert convert_array_to_matrix(cg) == a*b.T + + cg = _array_diagonal(_array_tensor_product(I1, a, b), (1, 3)) + assert _array_diag2contr_diagmatrix(cg) == _array_contraction(_array_tensor_product(OneArray(1), a, b, I1), (2, 6)) + assert convert_array_to_matrix(cg) == a*b.T + + cg = _array_diagonal(_array_tensor_product(x, I1), (1, 2)) + assert isinstance(cg, ArrayDiagonal) + assert cg.diagonal_indices == ((1, 2),) + assert convert_array_to_matrix(cg) == x + + cg = _array_diagonal(_array_tensor_product(x, I), (0, 2)) + assert _array_diag2contr_diagmatrix(cg) == _array_contraction(_array_tensor_product(OneArray(1), I, DiagMatrix(x)), (1, 3)) + assert convert_array_to_matrix(cg).doit() == DiagMatrix(x) + + raises(ValueError, lambda: _array_diagonal(x, (1,))) + + # Ignore identity matrices with contractions: + + cg = _array_contraction(_array_tensor_product(I, A, I, I), (0, 2), (1, 3), (5, 7)) + assert cg.split_multiple_contractions() == cg + assert convert_array_to_matrix(cg) == Trace(A) * I + + cg = _array_contraction(_array_tensor_product(Trace(A) * I, I, I), (1, 5), (3, 4)) + assert cg.split_multiple_contractions() == cg + assert convert_array_to_matrix(cg).doit() == Trace(A) * I + + # Add DiagMatrix when required: + + cg = _array_contraction(_array_tensor_product(A, a), (1, 2)) + assert cg.split_multiple_contractions() == cg + assert convert_array_to_matrix(cg) == A * a + + cg = _array_contraction(_array_tensor_product(A, a, B), (1, 2, 4)) + assert cg.split_multiple_contractions() == _array_contraction(_array_tensor_product(A, DiagMatrix(a), OneArray(1), B), (1, 2), (3, 5)) + assert convert_array_to_matrix(cg) == A * DiagMatrix(a) * B + + cg = _array_contraction(_array_tensor_product(A, a, B), (0, 2, 4)) + assert cg.split_multiple_contractions() == _array_contraction(_array_tensor_product(A, DiagMatrix(a), OneArray(1), B), (0, 2), (3, 5)) + assert convert_array_to_matrix(cg) == A.T * DiagMatrix(a) * B + + cg = _array_contraction(_array_tensor_product(A, a, b, a.T, B), (0, 2, 4, 7, 9)) + assert cg.split_multiple_contractions() == _array_contraction(_array_tensor_product(A, DiagMatrix(a), OneArray(1), + DiagMatrix(b), OneArray(1), DiagMatrix(a), OneArray(1), B), + (0, 2), (3, 5), (6, 9), (8, 12)) + assert convert_array_to_matrix(cg) == A.T * DiagMatrix(a) * DiagMatrix(b) * DiagMatrix(a) * B.T + + cg = _array_contraction(_array_tensor_product(I1, I1, I1), (1, 2, 4)) + assert cg.split_multiple_contractions() == _array_contraction(_array_tensor_product(I1, I1, OneArray(1), I1), (1, 2), (3, 5)) + assert convert_array_to_matrix(cg) == 1 + + cg = _array_contraction(_array_tensor_product(I, I, I, I, A), (1, 2, 8), (5, 6, 9)) + assert convert_array_to_matrix(cg.split_multiple_contractions()).doit() == A + + cg = _array_contraction(_array_tensor_product(A, a, C, a, B), (1, 2, 4), (5, 6, 8)) + expected = _array_contraction(_array_tensor_product(A, DiagMatrix(a), OneArray(1), C, DiagMatrix(a), OneArray(1), B), (1, 3), (2, 5), (6, 7), (8, 10)) + assert cg.split_multiple_contractions() == expected + assert convert_array_to_matrix(cg) == A * DiagMatrix(a) * C * DiagMatrix(a) * B + + cg = _array_contraction(_array_tensor_product(a, I1, b, I1, (a.T*b).applyfunc(cos)), (1, 2, 8), (5, 6, 9)) + expected = _array_contraction(_array_tensor_product(a, I1, OneArray(1), b, I1, OneArray(1), (a.T*b).applyfunc(cos)), + (1, 3), (2, 10), (6, 8), (7, 11)) + assert cg.split_multiple_contractions().dummy_eq(expected) + assert convert_array_to_matrix(cg).doit().dummy_eq(MatMul(a, (a.T * b).applyfunc(cos), b.T)) + + +def test_arrayexpr_convert_array_contraction_tp_additions(): + a = ArrayAdd( + _array_tensor_product(M, N), + _array_tensor_product(N, M) + ) + tp = _array_tensor_product(P, a, Q) + expr = _array_contraction(tp, (3, 4)) + expected = _array_tensor_product( + P, + ArrayAdd( + _array_contraction(_array_tensor_product(M, N), (1, 2)), + _array_contraction(_array_tensor_product(N, M), (1, 2)), + ), + Q + ) + assert expr == expected + assert convert_array_to_matrix(expr) == _array_tensor_product(P, M * N + N * M, Q) + + expr = _array_contraction(tp, (1, 2), (3, 4), (5, 6)) + result = _array_contraction( + _array_tensor_product( + P, + ArrayAdd( + _array_contraction(_array_tensor_product(M, N), (1, 2)), + _array_contraction(_array_tensor_product(N, M), (1, 2)), + ), + Q + ), (1, 2), (3, 4)) + assert expr == result + assert convert_array_to_matrix(expr) == P * (M * N + N * M) * Q + + +def test_arrayexpr_convert_array_to_implicit_matmul(): + # Trivial dimensions are suppressed, so the result can be expressed in matrix form: + + cg = _array_tensor_product(a, b) + assert convert_array_to_matrix(cg) == a * b.T + + cg = _array_tensor_product(a, b, I) + assert convert_array_to_matrix(cg) == _array_tensor_product(a*b.T, I) + + cg = _array_tensor_product(I, a, b) + assert convert_array_to_matrix(cg) == _array_tensor_product(I, a*b.T) + + cg = _array_tensor_product(a, I, b) + assert convert_array_to_matrix(cg) == _array_tensor_product(a, I, b) + + cg = _array_contraction(_array_tensor_product(I, I), (1, 2)) + assert convert_array_to_matrix(cg) == I + + cg = PermuteDims(_array_tensor_product(I, Identity(1)), [0, 2, 1, 3]) + assert convert_array_to_matrix(cg) == I + + +def test_arrayexpr_convert_array_to_matrix_remove_trivial_dims(): + + # Tensor Product: + assert _remove_trivial_dims(_array_tensor_product(a, b)) == (a * b.T, [1, 3]) + assert _remove_trivial_dims(_array_tensor_product(a.T, b)) == (a * b.T, [0, 3]) + assert _remove_trivial_dims(_array_tensor_product(a, b.T)) == (a * b.T, [1, 2]) + assert _remove_trivial_dims(_array_tensor_product(a.T, b.T)) == (a * b.T, [0, 2]) + + assert _remove_trivial_dims(_array_tensor_product(I, a.T, b.T)) == (_array_tensor_product(I, a * b.T), [2, 4]) + assert _remove_trivial_dims(_array_tensor_product(a.T, I, b.T)) == (_array_tensor_product(a.T, I, b.T), []) + + assert _remove_trivial_dims(_array_tensor_product(a, I)) == (_array_tensor_product(a, I), []) + assert _remove_trivial_dims(_array_tensor_product(I, a)) == (_array_tensor_product(I, a), []) + + assert _remove_trivial_dims(_array_tensor_product(a.T, b.T, c, d)) == ( + _array_tensor_product(a * b.T, c * d.T), [0, 2, 5, 7]) + assert _remove_trivial_dims(_array_tensor_product(a.T, I, b.T, c, d, I)) == ( + _array_tensor_product(a.T, I, b*c.T, d, I), [4, 7]) + + # Addition: + + cg = ArrayAdd(_array_tensor_product(a, b), _array_tensor_product(c, d)) + assert _remove_trivial_dims(cg) == (a * b.T + c * d.T, [1, 3]) + + # Permute Dims: + + cg = PermuteDims(_array_tensor_product(a, b), Permutation(3)(1, 2)) + assert _remove_trivial_dims(cg) == (a * b.T, [2, 3]) + + cg = PermuteDims(_array_tensor_product(a, I, b), Permutation(5)(1, 2, 3, 4)) + assert _remove_trivial_dims(cg) == (cg, []) + + cg = PermuteDims(_array_tensor_product(I, b, a), Permutation(5)(1, 2, 4, 5, 3)) + assert _remove_trivial_dims(cg) == (PermuteDims(_array_tensor_product(I, b * a.T), [0, 2, 3, 1]), [4, 5]) + + # Diagonal: + + cg = _array_diagonal(_array_tensor_product(M, a), (1, 2)) + assert _remove_trivial_dims(cg) == (cg, []) + + # Contraction: + + cg = _array_contraction(_array_tensor_product(M, a), (1, 2)) + assert _remove_trivial_dims(cg) == (cg, []) + + # A few more cases to test the removal and shift of nested removed axes + # with array contractions and array diagonals: + tp = _array_tensor_product( + OneMatrix(1, 1), + M, + x, + OneMatrix(1, 1), + Identity(1), + ) + + expr = _array_contraction(tp, (1, 8)) + rexpr, removed = _remove_trivial_dims(expr) + assert removed == [0, 5, 6, 7] + + expr = _array_contraction(tp, (1, 8), (3, 4)) + rexpr, removed = _remove_trivial_dims(expr) + assert removed == [0, 3, 4, 5] + + expr = _array_diagonal(tp, (1, 8)) + rexpr, removed = _remove_trivial_dims(expr) + assert removed == [0, 5, 6, 7, 8] + + expr = _array_diagonal(tp, (1, 8), (3, 4)) + rexpr, removed = _remove_trivial_dims(expr) + assert removed == [0, 3, 4, 5, 6] + + expr = _array_diagonal(_array_contraction(_array_tensor_product(A, x, I, I1), (1, 2, 5)), (1, 4)) + rexpr, removed = _remove_trivial_dims(expr) + assert removed == [2, 3] + + cg = _array_diagonal(_array_tensor_product(PermuteDims(_array_tensor_product(x, I1), Permutation(1, 2, 3)), (x.T*x).applyfunc(sqrt)), (2, 4), (3, 5)) + rexpr, removed = _remove_trivial_dims(cg) + assert removed == [1, 2] + + # Contractions with identity matrices need to be followed by a permutation + # in order + cg = _array_contraction(_array_tensor_product(A, B, C, M, I), (1, 8)) + ret, removed = _remove_trivial_dims(cg) + assert ret == PermuteDims(_array_tensor_product(A, B, C, M), [0, 2, 3, 4, 5, 6, 7, 1]) + assert removed == [] + + cg = _array_contraction(_array_tensor_product(A, B, C, M, I), (1, 8), (3, 4)) + ret, removed = _remove_trivial_dims(cg) + assert ret == PermuteDims(_array_contraction(_array_tensor_product(A, B, C, M), (3, 4)), [0, 2, 3, 4, 5, 1]) + assert removed == [] + + # Trivial matrices are sometimes inserted into MatMul expressions: + + cg = _array_tensor_product(b*b.T, a.T*a) + ret, removed = _remove_trivial_dims(cg) + assert ret == b*a.T*a*b.T + assert removed == [2, 3] + + Xs = ArraySymbol("X", (3, 2, k)) + cg = _array_tensor_product(M, Xs, b.T*c, a*a.T, b*b.T, c.T*d) + ret, removed = _remove_trivial_dims(cg) + assert ret == _array_tensor_product(M, Xs, a*b.T*c*c.T*d*a.T, b*b.T) + assert removed == [5, 6, 11, 12] + + cg = _array_diagonal(_array_tensor_product(I, I1, x), (1, 4), (3, 5)) + assert _remove_trivial_dims(cg) == (PermuteDims(_array_diagonal(_array_tensor_product(I, x), (1, 2)), Permutation(1, 2)), [1]) + + expr = _array_diagonal(_array_tensor_product(x, I, y), (0, 2)) + assert _remove_trivial_dims(expr) == (PermuteDims(_array_tensor_product(DiagMatrix(x), y), [1, 2, 3, 0]), [0]) + + expr = _array_diagonal(_array_tensor_product(x, I, y), (0, 2), (3, 4)) + assert _remove_trivial_dims(expr) == (expr, []) + + +def test_arrayexpr_convert_array_to_matrix_diag2contraction_diagmatrix(): + cg = _array_diagonal(_array_tensor_product(M, a), (1, 2)) + res = _array_diag2contr_diagmatrix(cg) + assert res.shape == cg.shape + assert res == _array_contraction(_array_tensor_product(M, OneArray(1), DiagMatrix(a)), (1, 3)) + + raises(ValueError, lambda: _array_diagonal(_array_tensor_product(a, M), (1, 2))) + + cg = _array_diagonal(_array_tensor_product(a.T, M), (1, 2)) + res = _array_diag2contr_diagmatrix(cg) + assert res.shape == cg.shape + assert res == _array_contraction(_array_tensor_product(OneArray(1), M, DiagMatrix(a.T)), (1, 4)) + + cg = _array_diagonal(_array_tensor_product(a.T, M, N, b.T), (1, 2), (4, 7)) + res = _array_diag2contr_diagmatrix(cg) + assert res.shape == cg.shape + assert res == _array_contraction( + _array_tensor_product(OneArray(1), M, N, OneArray(1), DiagMatrix(a.T), DiagMatrix(b.T)), (1, 7), (3, 9)) + + cg = _array_diagonal(_array_tensor_product(a, M, N, b.T), (0, 2), (4, 7)) + res = _array_diag2contr_diagmatrix(cg) + assert res.shape == cg.shape + assert res == _array_contraction( + _array_tensor_product(OneArray(1), M, N, OneArray(1), DiagMatrix(a), DiagMatrix(b.T)), (1, 6), (3, 9)) + + cg = _array_diagonal(_array_tensor_product(a, M, N, b.T), (0, 4), (3, 7)) + res = _array_diag2contr_diagmatrix(cg) + assert res.shape == cg.shape + assert res == _array_contraction( + _array_tensor_product(OneArray(1), M, N, OneArray(1), DiagMatrix(a), DiagMatrix(b.T)), (3, 6), (2, 9)) + + I1 = Identity(1) + x = MatrixSymbol("x", k, 1) + A = MatrixSymbol("A", k, k) + cg = _array_diagonal(_array_tensor_product(x, A.T, I1), (0, 2)) + assert _array_diag2contr_diagmatrix(cg).shape == cg.shape + assert _array2matrix(cg).shape == cg.shape + + +def test_arrayexpr_convert_array_to_matrix_support_function(): + + assert _support_function_tp1_recognize([], [2 * k]) == 2 * k + + assert _support_function_tp1_recognize([(1, 2)], [A, 2 * k, B, 3]) == 6 * k * A * B + + assert _support_function_tp1_recognize([(0, 3), (1, 2)], [A, B]) == Trace(A * B) + + assert _support_function_tp1_recognize([(1, 2)], [A, B]) == A * B + assert _support_function_tp1_recognize([(0, 2)], [A, B]) == A.T * B + assert _support_function_tp1_recognize([(1, 3)], [A, B]) == A * B.T + assert _support_function_tp1_recognize([(0, 3)], [A, B]) == A.T * B.T + + assert _support_function_tp1_recognize([(1, 2), (5, 6)], [A, B, C, D]) == _array_tensor_product(A * B, C * D) + assert _support_function_tp1_recognize([(1, 4), (3, 6)], [A, B, C, D]) == PermuteDims( + _array_tensor_product(A * C, B * D), [0, 2, 1, 3]) + + assert _support_function_tp1_recognize([(0, 3), (1, 4)], [A, B, C]) == B * A * C + + assert _support_function_tp1_recognize([(9, 10), (1, 2), (5, 6), (3, 4), (7, 8)], + [X, Y, A, B, C, D]) == X * Y * A * B * C * D + + assert _support_function_tp1_recognize([(9, 10), (1, 2), (5, 6), (3, 4)], + [X, Y, A, B, C, D]) == _array_tensor_product(X * Y * A * B, C * D) + + assert _support_function_tp1_recognize([(1, 7), (3, 8), (4, 11)], [X, Y, A, B, C, D]) == PermuteDims( + _array_tensor_product(X * B.T, Y * C, A.T * D.T), [0, 2, 4, 1, 3, 5] + ) + + assert _support_function_tp1_recognize([(0, 1), (3, 6), (5, 8)], [X, A, B, C, D]) == PermuteDims( + _array_tensor_product(Trace(X) * A * C, B * D), [0, 2, 1, 3]) + + assert _support_function_tp1_recognize([(1, 2), (3, 4), (5, 6), (7, 8)], [A, A, B, C, D]) == A ** 2 * B * C * D + assert _support_function_tp1_recognize([(1, 2), (3, 4), (5, 6), (7, 8)], [X, A, B, C, D]) == X * A * B * C * D + + assert _support_function_tp1_recognize([(1, 6), (3, 8), (5, 10)], [X, Y, A, B, C, D]) == PermuteDims( + _array_tensor_product(X * B, Y * C, A * D), [0, 2, 4, 1, 3, 5] + ) + + assert _support_function_tp1_recognize([(1, 4), (3, 6)], [A, B, C, D]) == PermuteDims( + _array_tensor_product(A * C, B * D), [0, 2, 1, 3]) + + assert _support_function_tp1_recognize([(0, 4), (1, 7), (2, 5), (3, 8)], [X, A, B, C, D]) == C*X.T*B*A*D + + assert _support_function_tp1_recognize([(0, 4), (1, 7), (2, 5), (3, 8)], [X, A, B, C, D]) == C*X.T*B*A*D + + +def test_convert_array_to_hadamard_products(): + + expr = HadamardProduct(M, N) + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == expr + + expr = HadamardProduct(M, N)*P + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == expr + + expr = Q*HadamardProduct(M, N)*P + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == expr + + expr = Q*HadamardProduct(M, N.T)*P + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == expr + + expr = HadamardProduct(M, N)*HadamardProduct(Q, P) + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert expr == ret + + expr = P.T*HadamardProduct(M, N)*HadamardProduct(Q, P) + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert expr == ret + + # ArrayDiagonal should be converted + cg = _array_diagonal(_array_tensor_product(M, N, Q), (1, 3), (0, 2, 4)) + ret = convert_array_to_matrix(cg) + expected = PermuteDims(_array_diagonal(_array_tensor_product(HadamardProduct(M.T, N.T), Q), (1, 2)), [1, 0, 2]) + assert expected == ret + + # Special case that should return the same expression: + cg = _array_diagonal(_array_tensor_product(HadamardProduct(M, N), Q), (0, 2)) + ret = convert_array_to_matrix(cg) + assert ret == cg + + # Hadamard products with traces: + + expr = Trace(HadamardProduct(M, N)) + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == Trace(HadamardProduct(M.T, N.T)) + + expr = Trace(A*HadamardProduct(M, N)) + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == Trace(HadamardProduct(M, N)*A) + + expr = Trace(HadamardProduct(A, M)*N) + cg = convert_matrix_to_array(expr) + ret = convert_array_to_matrix(cg) + assert ret == Trace(HadamardProduct(M.T, N)*A) + + # These should not be converted into Hadamard products: + + cg = _array_diagonal(_array_tensor_product(M, N), (0, 1, 2, 3)) + ret = convert_array_to_matrix(cg) + assert ret == cg + + cg = _array_diagonal(_array_tensor_product(A), (0, 1)) + ret = convert_array_to_matrix(cg) + assert ret == cg + + cg = _array_diagonal(_array_tensor_product(M, N, P), (0, 2, 4), (1, 3, 5)) + assert convert_array_to_matrix(cg) == HadamardProduct(M, N, P) + + cg = _array_diagonal(_array_tensor_product(M, N, P), (0, 3, 4), (1, 2, 5)) + assert convert_array_to_matrix(cg) == HadamardProduct(M, P, N.T) + + cg = _array_diagonal(_array_tensor_product(I, I1, x), (1, 4), (3, 5)) + assert convert_array_to_matrix(cg) == DiagMatrix(x) + + +def test_identify_removable_identity_matrices(): + + D = DiagonalMatrix(MatrixSymbol("D", k, k)) + + cg = _array_contraction(_array_tensor_product(A, B, I), (1, 2, 4, 5)) + expected = _array_contraction(_array_tensor_product(A, B), (1, 2)) + assert identify_removable_identity_matrices(cg) == expected + + cg = _array_contraction(_array_tensor_product(A, B, C, I), (1, 3, 5, 6, 7)) + expected = _array_contraction(_array_tensor_product(A, B, C), (1, 3, 5)) + assert identify_removable_identity_matrices(cg) == expected + + # Tests with diagonal matrices: + + cg = _array_contraction(_array_tensor_product(A, B, D), (1, 2, 4, 5)) + ret = identify_removable_identity_matrices(cg) + expected = _array_contraction(_array_tensor_product(A, B, D), (1, 4), (2, 5)) + assert ret == expected + + cg = _array_contraction(_array_tensor_product(A, B, D, M, N), (1, 2, 4, 5, 6, 8)) + ret = identify_removable_identity_matrices(cg) + assert ret == cg + + +def test_combine_removed(): + + assert _combine_removed(6, [0, 1, 2], [0, 1, 2]) == [0, 1, 2, 3, 4, 5] + assert _combine_removed(8, [2, 5], [1, 3, 4]) == [1, 2, 4, 5, 6] + assert _combine_removed(8, [7], []) == [7] + + +def test_array_contraction_to_diagonal_multiple_identities(): + + expr = _array_contraction(_array_tensor_product(A, B, I, C), (1, 2, 4), (5, 6)) + assert _array_contraction_to_diagonal_multiple_identity(expr) == (expr, []) + assert convert_array_to_matrix(expr) == _array_contraction(_array_tensor_product(A, B, C), (1, 2, 4)) + + expr = _array_contraction(_array_tensor_product(A, I, I), (1, 2, 4)) + assert _array_contraction_to_diagonal_multiple_identity(expr) == (A, [2]) + assert convert_array_to_matrix(expr) == A + + expr = _array_contraction(_array_tensor_product(A, I, I, B), (1, 2, 4), (3, 6)) + assert _array_contraction_to_diagonal_multiple_identity(expr) == (expr, []) + + expr = _array_contraction(_array_tensor_product(A, I, I, B), (1, 2, 3, 4, 6)) + assert _array_contraction_to_diagonal_multiple_identity(expr) == (expr, []) + + +def test_convert_array_element_to_matrix(): + + expr = ArrayElement(M, (i, j)) + assert convert_array_to_matrix(expr) == MatrixElement(M, i, j) + + expr = ArrayElement(_array_contraction(_array_tensor_product(M, N), (1, 3)), (i, j)) + assert convert_array_to_matrix(expr) == MatrixElement(M*N.T, i, j) + + expr = ArrayElement(_array_tensor_product(M, N), (i, j, m, n)) + assert convert_array_to_matrix(expr) == expr + + +def test_convert_array_elementwise_function_to_matrix(): + + d = Dummy("d") + + expr = ArrayElementwiseApplyFunc(Lambda(d, sin(d)), x.T*y) + assert convert_array_to_matrix(expr) == sin(x.T*y) + + expr = ArrayElementwiseApplyFunc(Lambda(d, d**2), x.T*y) + assert convert_array_to_matrix(expr) == (x.T*y)**2 + + expr = ArrayElementwiseApplyFunc(Lambda(d, sin(d)), x) + assert convert_array_to_matrix(expr).dummy_eq(x.applyfunc(sin)) + + expr = ArrayElementwiseApplyFunc(Lambda(d, 1 / (2 * sqrt(d))), x) + assert convert_array_to_matrix(expr) == S.Half * HadamardPower(x, -S.Half) + + +def test_array2matrix(): + # See issue https://github.com/sympy/sympy/pull/22877 + expr = PermuteDims(ArrayContraction(ArrayTensorProduct(x, I, I1, x), (0, 3), (1, 7)), Permutation(2, 3)) + expected = PermuteDims(ArrayTensorProduct(x*x.T, I1), Permutation(3)(1, 2)) + assert _array2matrix(expr) == expected + + +def test_recognize_broadcasting(): + expr = ArrayTensorProduct(x.T*x, A) + assert _remove_trivial_dims(expr) == (KroneckerProduct(x.T*x, A), [0, 1]) + + expr = ArrayTensorProduct(A, x.T*x) + assert _remove_trivial_dims(expr) == (KroneckerProduct(A, x.T*x), [2, 3]) + + expr = ArrayTensorProduct(A, B, x.T*x, C) + assert _remove_trivial_dims(expr) == (ArrayTensorProduct(A, KroneckerProduct(B, x.T*x), C), [4, 5]) + + # Always prefer matrix multiplication to Kronecker product, if possible: + expr = ArrayTensorProduct(a, b, x.T*x) + assert _remove_trivial_dims(expr) == (a*x.T*x*b.T, [1, 3, 4, 5]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_indexed_to_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_indexed_to_array.py new file mode 100644 index 0000000000000000000000000000000000000000..258062eadeca041ae3c864dabeefd5165f1cef11 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_indexed_to_array.py @@ -0,0 +1,205 @@ +from sympy import tanh +from sympy.concrete.summations import Sum +from sympy.core.symbol import symbols +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.special import Identity +from sympy.tensor.array.expressions import ArrayElementwiseApplyFunc +from sympy.tensor.indexed import IndexedBase +from sympy.combinatorics import Permutation +from sympy.tensor.array.expressions.array_expressions import ArrayContraction, ArrayTensorProduct, \ + ArrayDiagonal, ArrayAdd, PermuteDims, ArrayElement, _array_tensor_product, _array_contraction, _array_diagonal, \ + _array_add, _permute_dims, ArraySymbol, OneArray +from sympy.tensor.array.expressions.from_array_to_matrix import convert_array_to_matrix +from sympy.tensor.array.expressions.from_indexed_to_array import convert_indexed_to_array, _convert_indexed_to_array +from sympy.testing.pytest import raises + + +A, B = symbols("A B", cls=IndexedBase) +i, j, k, l, m, n = symbols("i j k l m n") +d0, d1, d2, d3 = symbols("d0:4") + +I = Identity(k) + +M = MatrixSymbol("M", k, k) +N = MatrixSymbol("N", k, k) +P = MatrixSymbol("P", k, k) +Q = MatrixSymbol("Q", k, k) + +a = MatrixSymbol("a", k, 1) +b = MatrixSymbol("b", k, 1) +c = MatrixSymbol("c", k, 1) +d = MatrixSymbol("d", k, 1) + + +def test_arrayexpr_convert_index_to_array_support_function(): + expr = M[i, j] + assert _convert_indexed_to_array(expr) == (M, (i, j)) + expr = M[i, j]*N[k, l] + assert _convert_indexed_to_array(expr) == (ArrayTensorProduct(M, N), (i, j, k, l)) + expr = M[i, j]*N[j, k] + assert _convert_indexed_to_array(expr) == (ArrayDiagonal(ArrayTensorProduct(M, N), (1, 2)), (i, k, j)) + expr = Sum(M[i, j]*N[j, k], (j, 0, k-1)) + assert _convert_indexed_to_array(expr) == (ArrayContraction(ArrayTensorProduct(M, N), (1, 2)), (i, k)) + expr = M[i, j] + N[i, j] + assert _convert_indexed_to_array(expr) == (ArrayAdd(M, N), (i, j)) + expr = M[i, j] + N[j, i] + assert _convert_indexed_to_array(expr) == (ArrayAdd(M, PermuteDims(N, Permutation([1, 0]))), (i, j)) + expr = M[i, j] + M[j, i] + assert _convert_indexed_to_array(expr) == (ArrayAdd(M, PermuteDims(M, Permutation([1, 0]))), (i, j)) + expr = (M*N*P)[i, j] + assert _convert_indexed_to_array(expr) == (_array_contraction(ArrayTensorProduct(M, N, P), (1, 2), (3, 4)), (i, j)) + expr = expr.function # Disregard summation in previous expression + ret1, ret2 = _convert_indexed_to_array(expr) + assert ret1 == ArrayDiagonal(ArrayTensorProduct(M, N, P), (1, 2), (3, 4)) + assert str(ret2) == "(i, j, _i_1, _i_2)" + expr = KroneckerDelta(i, j)*M[i, k] + assert _convert_indexed_to_array(expr) == (M, ({i, j}, k)) + expr = KroneckerDelta(i, j)*KroneckerDelta(j, k)*M[i, l] + assert _convert_indexed_to_array(expr) == (M, ({i, j, k}, l)) + expr = KroneckerDelta(j, k)*(M[i, j]*N[k, l] + N[i, j]*M[k, l]) + assert _convert_indexed_to_array(expr) == (_array_diagonal(_array_add( + ArrayTensorProduct(M, N), + _permute_dims(ArrayTensorProduct(M, N), Permutation(0, 2)(1, 3)) + ), (1, 2)), (i, l, frozenset({j, k}))) + expr = KroneckerDelta(j, m)*KroneckerDelta(m, k)*(M[i, j]*N[k, l] + N[i, j]*M[k, l]) + assert _convert_indexed_to_array(expr) == (_array_diagonal(_array_add( + ArrayTensorProduct(M, N), + _permute_dims(ArrayTensorProduct(M, N), Permutation(0, 2)(1, 3)) + ), (1, 2)), (i, l, frozenset({j, m, k}))) + expr = KroneckerDelta(i, j)*KroneckerDelta(j, k)*KroneckerDelta(k,m)*M[i, 0]*KroneckerDelta(m, n) + assert _convert_indexed_to_array(expr) == (M, ({i, j, k, m, n}, 0)) + expr = M[i, i] + assert _convert_indexed_to_array(expr) == (ArrayDiagonal(M, (0, 1)), (i,)) + + +def test_arrayexpr_convert_indexed_to_array_expression(): + + s = Sum(A[i]*B[i], (i, 0, 3)) + cg = convert_indexed_to_array(s) + assert cg == ArrayContraction(ArrayTensorProduct(A, B), (0, 1)) + + expr = M*N + result = ArrayContraction(ArrayTensorProduct(M, N), (1, 2)) + elem = expr[i, j] + assert convert_indexed_to_array(elem) == result + + expr = M*N*M + elem = expr[i, j] + result = _array_contraction(_array_tensor_product(M, M, N), (1, 4), (2, 5)) + cg = convert_indexed_to_array(elem) + assert cg == result + + cg = convert_indexed_to_array((M * N * P)[i, j]) + assert cg == _array_contraction(ArrayTensorProduct(M, N, P), (1, 2), (3, 4)) + + cg = convert_indexed_to_array((M * N.T * P)[i, j]) + assert cg == _array_contraction(ArrayTensorProduct(M, N, P), (1, 3), (2, 4)) + + expr = -2*M*N + elem = expr[i, j] + cg = convert_indexed_to_array(elem) + assert cg == ArrayContraction(ArrayTensorProduct(-2, M, N), (1, 2)) + + +def test_arrayexpr_convert_array_element_to_array_expression(): + A = ArraySymbol("A", (k,)) + B = ArraySymbol("B", (k,)) + + s = Sum(A[i]*B[i], (i, 0, k-1)) + cg = convert_indexed_to_array(s) + assert cg == ArrayContraction(ArrayTensorProduct(A, B), (0, 1)) + + s = A[i]*B[i] + cg = convert_indexed_to_array(s) + assert cg == ArrayDiagonal(ArrayTensorProduct(A, B), (0, 1)) + + s = A[i]*B[j] + cg = convert_indexed_to_array(s, [i, j]) + assert cg == ArrayTensorProduct(A, B) + cg = convert_indexed_to_array(s, [j, i]) + assert cg == ArrayTensorProduct(B, A) + + s = tanh(A[i]*B[j]) + cg = convert_indexed_to_array(s, [i, j]) + assert cg.dummy_eq(ArrayElementwiseApplyFunc(tanh, ArrayTensorProduct(A, B))) + + +def test_arrayexpr_convert_indexed_to_array_and_back_to_matrix(): + + expr = a.T*b + elem = expr[0, 0] + cg = convert_indexed_to_array(elem) + assert cg == ArrayElement(ArrayContraction(ArrayTensorProduct(a, b), (0, 2)), [0, 0]) + + expr = M[i,j] + N[i,j] + p1, p2 = _convert_indexed_to_array(expr) + assert convert_array_to_matrix(p1) == M + N + + expr = M[i,j] + N[j,i] + p1, p2 = _convert_indexed_to_array(expr) + assert convert_array_to_matrix(p1) == M + N.T + + expr = M[i,j]*N[k,l] + N[i,j]*M[k,l] + p1, p2 = _convert_indexed_to_array(expr) + assert convert_array_to_matrix(p1) == ArrayAdd( + ArrayTensorProduct(M, N), + ArrayTensorProduct(N, M)) + + expr = (M*N*P)[i, j] + p1, p2 = _convert_indexed_to_array(expr) + assert convert_array_to_matrix(p1) == M * N * P + + expr = Sum(M[i,j]*(N*P)[j,m], (j, 0, k-1)) + p1, p2 = _convert_indexed_to_array(expr) + assert convert_array_to_matrix(p1) == M * N * P + + expr = Sum((P[j, m] + P[m, j])*(M[i,j]*N[m,n] + N[i,j]*M[m,n]), (j, 0, k-1), (m, 0, k-1)) + p1, p2 = _convert_indexed_to_array(expr) + assert convert_array_to_matrix(p1) == M * P * N + M * P.T * N + N * P * M + N * P.T * M + + +def test_arrayexpr_convert_indexed_to_array_out_of_bounds(): + + expr = Sum(M[i, i], (i, 0, 4)) + raises(ValueError, lambda: convert_indexed_to_array(expr)) + expr = Sum(M[i, i], (i, 0, k)) + raises(ValueError, lambda: convert_indexed_to_array(expr)) + expr = Sum(M[i, i], (i, 1, k-1)) + raises(ValueError, lambda: convert_indexed_to_array(expr)) + + expr = Sum(M[i, j]*N[j,m], (j, 0, 4)) + raises(ValueError, lambda: convert_indexed_to_array(expr)) + expr = Sum(M[i, j]*N[j,m], (j, 0, k)) + raises(ValueError, lambda: convert_indexed_to_array(expr)) + expr = Sum(M[i, j]*N[j,m], (j, 1, k-1)) + raises(ValueError, lambda: convert_indexed_to_array(expr)) + + +def test_arrayexpr_convert_indexed_to_array_broadcast(): + A = ArraySymbol("A", (3, 3)) + B = ArraySymbol("B", (3, 3)) + + expr = A[i, j] + B[k, l] + O2 = OneArray(3, 3) + expected = ArrayAdd(ArrayTensorProduct(A, O2), ArrayTensorProduct(O2, B)) + assert convert_indexed_to_array(expr) == expected + assert convert_indexed_to_array(expr, [i, j, k, l]) == expected + assert convert_indexed_to_array(expr, [l, k, i, j]) == ArrayAdd(PermuteDims(ArrayTensorProduct(O2, A), [1, 0, 2, 3]), PermuteDims(ArrayTensorProduct(B, O2), [1, 0, 2, 3])) + + expr = A[i, j] + B[j, k] + O1 = OneArray(3) + assert convert_indexed_to_array(expr, [i, j, k]) == ArrayAdd(ArrayTensorProduct(A, O1), ArrayTensorProduct(O1, B)) + + C = ArraySymbol("C", (d0, d1)) + D = ArraySymbol("D", (d3, d1)) + + expr = C[i, j] + D[k, j] + assert convert_indexed_to_array(expr, [i, j, k]) == ArrayAdd(ArrayTensorProduct(C, OneArray(d3)), PermuteDims(ArrayTensorProduct(OneArray(d0), D), [0, 2, 1])) + + X = ArraySymbol("X", (5, 3)) + + expr = X[i, n] - X[j, n] + assert convert_indexed_to_array(expr, [i, j, n]) == ArrayAdd(ArrayTensorProduct(-1, OneArray(5), X), PermuteDims(ArrayTensorProduct(X, OneArray(5)), [0, 2, 1])) + + raises(ValueError, lambda: convert_indexed_to_array(C[i, j] + D[i, j])) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_matrix_to_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_matrix_to_array.py new file mode 100644 index 0000000000000000000000000000000000000000..142585882588df6aa0e4648d9d8881ea755f42a0 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_convert_matrix_to_array.py @@ -0,0 +1,128 @@ +from sympy import Lambda, KroneckerProduct +from sympy.core.symbol import symbols, Dummy +from sympy.matrices.expressions.hadamard import (HadamardPower, HadamardProduct) +from sympy.matrices.expressions.inverse import Inverse +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.matrices.expressions.matpow import MatPow +from sympy.matrices.expressions.special import Identity +from sympy.matrices.expressions.trace import Trace +from sympy.matrices.expressions.transpose import Transpose +from sympy.tensor.array.expressions.array_expressions import ArrayTensorProduct, ArrayContraction, \ + PermuteDims, ArrayDiagonal, ArrayElementwiseApplyFunc, _array_contraction, _array_tensor_product, Reshape +from sympy.tensor.array.expressions.from_array_to_matrix import convert_array_to_matrix +from sympy.tensor.array.expressions.from_matrix_to_array import convert_matrix_to_array + +i, j, k, l, m, n = symbols("i j k l m n") + +I = Identity(k) + +M = MatrixSymbol("M", k, k) +N = MatrixSymbol("N", k, k) +P = MatrixSymbol("P", k, k) +Q = MatrixSymbol("Q", k, k) + +A = MatrixSymbol("A", k, k) +B = MatrixSymbol("B", k, k) +C = MatrixSymbol("C", k, k) +D = MatrixSymbol("D", k, k) + +X = MatrixSymbol("X", k, k) +Y = MatrixSymbol("Y", k, k) + +a = MatrixSymbol("a", k, 1) +b = MatrixSymbol("b", k, 1) +c = MatrixSymbol("c", k, 1) +d = MatrixSymbol("d", k, 1) + + +def test_arrayexpr_convert_matrix_to_array(): + + expr = M*N + result = ArrayContraction(ArrayTensorProduct(M, N), (1, 2)) + assert convert_matrix_to_array(expr) == result + + expr = M*N*M + result = _array_contraction(ArrayTensorProduct(M, N, M), (1, 2), (3, 4)) + assert convert_matrix_to_array(expr) == result + + expr = Transpose(M) + assert convert_matrix_to_array(expr) == PermuteDims(M, [1, 0]) + + expr = M*Transpose(N) + assert convert_matrix_to_array(expr) == _array_contraction(_array_tensor_product(M, PermuteDims(N, [1, 0])), (1, 2)) + + expr = 3*M*N + res = convert_matrix_to_array(expr) + rexpr = convert_array_to_matrix(res) + assert expr == rexpr + + expr = 3*M + N*M.T*M + 4*k*N + res = convert_matrix_to_array(expr) + rexpr = convert_array_to_matrix(res) + assert expr == rexpr + + expr = Inverse(M)*N + rexpr = convert_array_to_matrix(convert_matrix_to_array(expr)) + assert expr == rexpr + + expr = M**2 + rexpr = convert_array_to_matrix(convert_matrix_to_array(expr)) + assert expr == rexpr + + expr = M*(2*N + 3*M) + res = convert_matrix_to_array(expr) + rexpr = convert_array_to_matrix(res) + assert expr == rexpr + + expr = Trace(M) + result = ArrayContraction(M, (0, 1)) + assert convert_matrix_to_array(expr) == result + + expr = 3*Trace(M) + result = ArrayContraction(ArrayTensorProduct(3, M), (0, 1)) + assert convert_matrix_to_array(expr) == result + + expr = 3*Trace(Trace(M) * M) + result = ArrayContraction(ArrayTensorProduct(3, M, M), (0, 1), (2, 3)) + assert convert_matrix_to_array(expr) == result + + expr = 3*Trace(M)**2 + result = ArrayContraction(ArrayTensorProduct(3, M, M), (0, 1), (2, 3)) + assert convert_matrix_to_array(expr) == result + + expr = HadamardProduct(M, N) + result = ArrayDiagonal(ArrayTensorProduct(M, N), (0, 2), (1, 3)) + assert convert_matrix_to_array(expr) == result + + expr = HadamardProduct(M*N, N*M) + result = ArrayDiagonal(ArrayContraction(ArrayTensorProduct(M, N, N, M), (1, 2), (5, 6)), (0, 2), (1, 3)) + assert convert_matrix_to_array(expr) == result + + expr = HadamardPower(M, 2) + result = ArrayDiagonal(ArrayTensorProduct(M, M), (0, 2), (1, 3)) + assert convert_matrix_to_array(expr) == result + + expr = HadamardPower(M*N, 2) + result = ArrayDiagonal(ArrayContraction(ArrayTensorProduct(M, N, M, N), (1, 2), (5, 6)), (0, 2), (1, 3)) + assert convert_matrix_to_array(expr) == result + + expr = HadamardPower(M, n) + d0 = Dummy("d0") + result = ArrayElementwiseApplyFunc(Lambda(d0, d0**n), M) + assert convert_matrix_to_array(expr).dummy_eq(result) + + expr = M**2 + assert isinstance(expr, MatPow) + assert convert_matrix_to_array(expr) == ArrayContraction(ArrayTensorProduct(M, M), (1, 2)) + + expr = a.T*b + cg = convert_matrix_to_array(expr) + assert cg == ArrayContraction(ArrayTensorProduct(a, b), (0, 2)) + + expr = KroneckerProduct(A, B) + cg = convert_matrix_to_array(expr) + assert cg == Reshape(PermuteDims(ArrayTensorProduct(A, B), [0, 2, 1, 3]), (k**2, k**2)) + + expr = KroneckerProduct(A, B, C, D) + cg = convert_matrix_to_array(expr) + assert cg == Reshape(PermuteDims(ArrayTensorProduct(A, B, C, D), [0, 2, 4, 6, 1, 3, 5, 7]), (k**4, k**4)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_deprecated_conv_modules.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_deprecated_conv_modules.py new file mode 100644 index 0000000000000000000000000000000000000000..b41b6105410a308e7774fce760b235497d0303bb --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/tests/test_deprecated_conv_modules.py @@ -0,0 +1,22 @@ +from sympy import MatrixSymbol, symbols, Sum +from sympy.tensor.array.expressions import conv_array_to_indexed, from_array_to_indexed, ArrayTensorProduct, \ + ArrayContraction, conv_array_to_matrix, from_array_to_matrix, conv_matrix_to_array, from_matrix_to_array, \ + conv_indexed_to_array, from_indexed_to_array +from sympy.testing.pytest import warns +from sympy.utilities.exceptions import SymPyDeprecationWarning + + +def test_deprecated_conv_module_results(): + + M = MatrixSymbol("M", 3, 3) + N = MatrixSymbol("N", 3, 3) + i, j, d = symbols("i j d") + + x = ArrayContraction(ArrayTensorProduct(M, N), (1, 2)) + y = Sum(M[i, d]*N[d, j], (d, 0, 2)) + + with warns(SymPyDeprecationWarning, test_stacklevel=False): + assert conv_array_to_indexed.convert_array_to_indexed(x, [i, j]).dummy_eq(from_array_to_indexed.convert_array_to_indexed(x, [i, j])) + assert conv_array_to_matrix.convert_array_to_matrix(x) == from_array_to_matrix.convert_array_to_matrix(x) + assert conv_matrix_to_array.convert_matrix_to_array(M*N) == from_matrix_to_array.convert_matrix_to_array(M*N) + assert conv_indexed_to_array.convert_indexed_to_array(y) == from_indexed_to_array.convert_indexed_to_array(y) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/utils.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/utils.py new file mode 100644 index 0000000000000000000000000000000000000000..e55c0e6ed47cdc9ff1c24cc92f006998aeb86822 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/expressions/utils.py @@ -0,0 +1,123 @@ +import bisect +from collections import defaultdict + +from sympy.combinatorics import Permutation +from sympy.core.containers import Tuple +from sympy.core.numbers import Integer + + +def _get_mapping_from_subranks(subranks): + mapping = {} + counter = 0 + for i, rank in enumerate(subranks): + for j in range(rank): + mapping[counter] = (i, j) + counter += 1 + return mapping + + +def _get_contraction_links(args, subranks, *contraction_indices): + mapping = _get_mapping_from_subranks(subranks) + contraction_tuples = [[mapping[j] for j in i] for i in contraction_indices] + dlinks = defaultdict(dict) + for links in contraction_tuples: + if len(links) == 2: + (arg1, pos1), (arg2, pos2) = links + dlinks[arg1][pos1] = (arg2, pos2) + dlinks[arg2][pos2] = (arg1, pos1) + continue + + return args, dict(dlinks) + + +def _sort_contraction_indices(pairing_indices): + pairing_indices = [Tuple(*sorted(i)) for i in pairing_indices] + pairing_indices.sort(key=lambda x: min(x)) + return pairing_indices + + +def _get_diagonal_indices(flattened_indices): + axes_contraction = defaultdict(list) + for i, ind in enumerate(flattened_indices): + if isinstance(ind, (int, Integer)): + # If the indices is a number, there can be no diagonal operation: + continue + axes_contraction[ind].append(i) + axes_contraction = {k: v for k, v in axes_contraction.items() if len(v) > 1} + # Put the diagonalized indices at the end: + ret_indices = [i for i in flattened_indices if i not in axes_contraction] + diag_indices = list(axes_contraction) + diag_indices.sort(key=lambda x: flattened_indices.index(x)) + diagonal_indices = [tuple(axes_contraction[i]) for i in diag_indices] + ret_indices += diag_indices + ret_indices = tuple(ret_indices) + return diagonal_indices, ret_indices + + +def _get_argindex(subindices, ind): + for i, sind in enumerate(subindices): + if ind == sind: + return i + if isinstance(sind, (set, frozenset)) and ind in sind: + return i + raise IndexError("%s not found in %s" % (ind, subindices)) + + +def _apply_recursively_over_nested_lists(func, arr): + if isinstance(arr, (tuple, list, Tuple)): + return tuple(_apply_recursively_over_nested_lists(func, i) for i in arr) + elif isinstance(arr, Tuple): + return Tuple.fromiter(_apply_recursively_over_nested_lists(func, i) for i in arr) + else: + return func(arr) + + +def _build_push_indices_up_func_transformation(flattened_contraction_indices): + shifts = {0: 0} + i = 0 + cumulative = 0 + while i < len(flattened_contraction_indices): + j = 1 + while i+j < len(flattened_contraction_indices): + if flattened_contraction_indices[i] + j != flattened_contraction_indices[i+j]: + break + j += 1 + cumulative += j + shifts[flattened_contraction_indices[i]] = cumulative + i += j + shift_keys = sorted(shifts.keys()) + + def func(idx): + return shifts[shift_keys[bisect.bisect_right(shift_keys, idx)-1]] + + def transform(j): + if j in flattened_contraction_indices: + return None + else: + return j - func(j) + + return transform + + +def _build_push_indices_down_func_transformation(flattened_contraction_indices): + N = flattened_contraction_indices[-1]+2 + + shifts = [i for i in range(N) if i not in flattened_contraction_indices] + + def transform(j): + if j < len(shifts): + return shifts[j] + else: + return j + shifts[-1] - len(shifts) + 1 + + return transform + + +def _apply_permutation_to_list(perm: Permutation, target_list: list): + """ + Permute a list according to the given permutation. + """ + new_list = [None for i in range(perm.size)] + for i, e in enumerate(target_list): + new_list[perm(i)] = e + return new_list diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/mutable_ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/mutable_ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..e1eaaf7241bc3b4a48234178d18da3aa5736e189 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/mutable_ndim_array.py @@ -0,0 +1,13 @@ +from sympy.tensor.array.ndim_array import NDimArray + + +class MutableNDimArray(NDimArray): + + def as_immutable(self): + raise NotImplementedError("abstract method") + + def as_mutable(self): + return self + + def _sympy_(self): + return self.as_immutable() diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..2b9a857b8cfd9ee46646c46f274636d6b9962b6e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/ndim_array.py @@ -0,0 +1,601 @@ +from sympy.core.basic import Basic +from sympy.core.containers import (Dict, Tuple) +from sympy.core.expr import Expr +from sympy.core.kind import Kind, NumberKind, UndefinedKind +from sympy.core.numbers import Integer +from sympy.core.singleton import S +from sympy.core.sympify import sympify +from sympy.external.gmpy import SYMPY_INTS +from sympy.printing.defaults import Printable + +import itertools +from collections.abc import Iterable + + +class ArrayKind(Kind): + """ + Kind for N-dimensional array in SymPy. + + This kind represents the multidimensional array that algebraic + operations are defined. Basic class for this kind is ``NDimArray``, + but any expression representing the array can have this. + + Parameters + ========== + + element_kind : Kind + Kind of the element. Default is :obj:NumberKind ``, + which means that the array contains only numbers. + + Examples + ======== + + Any instance of array class has ``ArrayKind``. + + >>> from sympy import NDimArray + >>> NDimArray([1,2,3]).kind + ArrayKind(NumberKind) + + Although expressions representing an array may be not instance of + array class, it will have ``ArrayKind`` as well. + + >>> from sympy import Integral + >>> from sympy.tensor.array import NDimArray + >>> from sympy.abc import x + >>> intA = Integral(NDimArray([1,2,3]), x) + >>> isinstance(intA, NDimArray) + False + >>> intA.kind + ArrayKind(NumberKind) + + Use ``isinstance()`` to check for ``ArrayKind` without specifying + the element kind. Use ``is`` with specifying the element kind. + + >>> from sympy.tensor.array import ArrayKind + >>> from sympy.core import NumberKind + >>> boolA = NDimArray([True, False]) + >>> isinstance(boolA.kind, ArrayKind) + True + >>> boolA.kind is ArrayKind(NumberKind) + False + + See Also + ======== + + shape : Function to return the shape of objects with ``MatrixKind``. + + """ + def __new__(cls, element_kind=NumberKind): + obj = super().__new__(cls, element_kind) + obj.element_kind = element_kind + return obj + + def __repr__(self): + return "ArrayKind(%s)" % self.element_kind + + @classmethod + def _union(cls, kinds) -> 'ArrayKind': + elem_kinds = {e.kind for e in kinds} + if len(elem_kinds) == 1: + elemkind, = elem_kinds + else: + elemkind = UndefinedKind + return ArrayKind(elemkind) + + +class NDimArray(Printable): + """N-dimensional array. + + Examples + ======== + + Create an N-dim array of zeros: + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray.zeros(2, 3, 4) + >>> a + [[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]], [[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]] + + Create an N-dim array from a list; + + >>> a = MutableDenseNDimArray([[2, 3], [4, 5]]) + >>> a + [[2, 3], [4, 5]] + + >>> b = MutableDenseNDimArray([[[1, 2], [3, 4], [5, 6]], [[7, 8], [9, 10], [11, 12]]]) + >>> b + [[[1, 2], [3, 4], [5, 6]], [[7, 8], [9, 10], [11, 12]]] + + Create an N-dim array from a flat list with dimension shape: + + >>> a = MutableDenseNDimArray([1, 2, 3, 4, 5, 6], (2, 3)) + >>> a + [[1, 2, 3], [4, 5, 6]] + + Create an N-dim array from a matrix: + + >>> from sympy import Matrix + >>> a = Matrix([[1,2],[3,4]]) + >>> a + Matrix([ + [1, 2], + [3, 4]]) + >>> b = MutableDenseNDimArray(a) + >>> b + [[1, 2], [3, 4]] + + Arithmetic operations on N-dim arrays + + >>> a = MutableDenseNDimArray([1, 1, 1, 1], (2, 2)) + >>> b = MutableDenseNDimArray([4, 4, 4, 4], (2, 2)) + >>> c = a + b + >>> c + [[5, 5], [5, 5]] + >>> a - b + [[-3, -3], [-3, -3]] + + """ + + _diff_wrt = True + is_scalar = False + + def __new__(cls, iterable, shape=None, **kwargs): + from sympy.tensor.array import ImmutableDenseNDimArray + return ImmutableDenseNDimArray(iterable, shape, **kwargs) + + def __getitem__(self, index): + raise NotImplementedError("A subclass of NDimArray should implement __getitem__") + + def _parse_index(self, index): + if isinstance(index, (SYMPY_INTS, Integer)): + if index >= self._loop_size: + raise ValueError("Only a tuple index is accepted") + return index + + if self._loop_size == 0: + raise ValueError("Index not valid with an empty array") + + if len(index) != self._rank: + raise ValueError('Wrong number of array axes') + + real_index = 0 + # check if input index can exist in current indexing + for i in range(self._rank): + if (index[i] >= self.shape[i]) or (index[i] < -self.shape[i]): + raise ValueError('Index ' + str(index) + ' out of border') + if index[i] < 0: + real_index += 1 + real_index = real_index*self.shape[i] + index[i] + + return real_index + + def _get_tuple_index(self, integer_index): + index = [] + for sh in reversed(self.shape): + index.append(integer_index % sh) + integer_index //= sh + index.reverse() + return tuple(index) + + def _check_symbolic_index(self, index): + # Check if any index is symbolic: + tuple_index = (index if isinstance(index, tuple) else (index,)) + if any((isinstance(i, Expr) and (not i.is_number)) for i in tuple_index): + for i, nth_dim in zip(tuple_index, self.shape): + if ((i < 0) == True) or ((i >= nth_dim) == True): + raise ValueError("index out of range") + from sympy.tensor import Indexed + return Indexed(self, *tuple_index) + return None + + def _setter_iterable_check(self, value): + from sympy.matrices.matrixbase import MatrixBase + if isinstance(value, (Iterable, MatrixBase, NDimArray)): + raise NotImplementedError + + @classmethod + def _scan_iterable_shape(cls, iterable): + def f(pointer): + if not isinstance(pointer, Iterable): + return [pointer], () + + if len(pointer) == 0: + return [], (0,) + + result = [] + elems, shapes = zip(*[f(i) for i in pointer]) + if len(set(shapes)) != 1: + raise ValueError("could not determine shape unambiguously") + for i in elems: + result.extend(i) + return result, (len(shapes),)+shapes[0] + + return f(iterable) + + @classmethod + def _handle_ndarray_creation_inputs(cls, iterable=None, shape=None, **kwargs): + from sympy.matrices.matrixbase import MatrixBase + from sympy.tensor.array import SparseNDimArray + + if shape is None: + if iterable is None: + shape = () + iterable = () + # Construction of a sparse array from a sparse array + elif isinstance(iterable, SparseNDimArray): + return iterable._shape, iterable._sparse_array + + # Construct N-dim array from another N-dim array: + elif isinstance(iterable, NDimArray): + shape = iterable.shape + + # Construct N-dim array from an iterable (numpy arrays included): + elif isinstance(iterable, Iterable): + iterable, shape = cls._scan_iterable_shape(iterable) + + # Construct N-dim array from a Matrix: + elif isinstance(iterable, MatrixBase): + shape = iterable.shape + + else: + shape = () + iterable = (iterable,) + + if isinstance(iterable, (Dict, dict)) and shape is not None: + new_dict = iterable.copy() + for k in new_dict: + if isinstance(k, (tuple, Tuple)): + new_key = 0 + for i, idx in enumerate(k): + new_key = new_key * shape[i] + idx + iterable[new_key] = iterable[k] + del iterable[k] + + if isinstance(shape, (SYMPY_INTS, Integer)): + shape = (shape,) + + if not all(isinstance(dim, (SYMPY_INTS, Integer)) for dim in shape): + raise TypeError("Shape should contain integers only.") + + return tuple(shape), iterable + + def __len__(self): + """Overload common function len(). Returns number of elements in array. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray.zeros(3, 3) + >>> a + [[0, 0, 0], [0, 0, 0], [0, 0, 0]] + >>> len(a) + 9 + + """ + return self._loop_size + + @property + def shape(self): + """ + Returns array shape (dimension). + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray.zeros(3, 3) + >>> a.shape + (3, 3) + + """ + return self._shape + + def rank(self): + """ + Returns rank of array. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray.zeros(3,4,5,6,3) + >>> a.rank() + 5 + + """ + return self._rank + + def diff(self, *args, **kwargs): + """ + Calculate the derivative of each element in the array. + + Examples + ======== + + >>> from sympy import ImmutableDenseNDimArray + >>> from sympy.abc import x, y + >>> M = ImmutableDenseNDimArray([[x, y], [1, x*y]]) + >>> M.diff(x) + [[1, 0], [0, y]] + + """ + from sympy.tensor.array.array_derivatives import ArrayDerivative + kwargs.setdefault('evaluate', True) + return ArrayDerivative(self.as_immutable(), *args, **kwargs) + + def _eval_derivative(self, base): + # Types are (base: scalar, self: array) + return self.applyfunc(lambda x: base.diff(x)) + + def _eval_derivative_n_times(self, s, n): + return Basic._eval_derivative_n_times(self, s, n) + + def applyfunc(self, f): + """Apply a function to each element of the N-dim array. + + Examples + ======== + + >>> from sympy import ImmutableDenseNDimArray + >>> m = ImmutableDenseNDimArray([i*2+j for i in range(2) for j in range(2)], (2, 2)) + >>> m + [[0, 1], [2, 3]] + >>> m.applyfunc(lambda i: 2*i) + [[0, 2], [4, 6]] + """ + from sympy.tensor.array import SparseNDimArray + from sympy.tensor.array.arrayop import Flatten + + if isinstance(self, SparseNDimArray) and f(S.Zero) == 0: + return type(self)({k: f(v) for k, v in self._sparse_array.items() if f(v) != 0}, self.shape) + + return type(self)(map(f, Flatten(self)), self.shape) + + def _sympystr(self, printer): + def f(sh, shape_left, i, j): + if len(shape_left) == 1: + return "["+", ".join([printer._print(self[self._get_tuple_index(e)]) for e in range(i, j)])+"]" + + sh //= shape_left[0] + return "[" + ", ".join([f(sh, shape_left[1:], i+e*sh, i+(e+1)*sh) for e in range(shape_left[0])]) + "]" # + "\n"*len(shape_left) + + if self.rank() == 0: + return printer._print(self[()]) + if 0 in self.shape: + return f"{self.__class__.__name__}([], {self.shape})" + return f(self._loop_size, self.shape, 0, self._loop_size) + + def tolist(self): + """ + Converting MutableDenseNDimArray to one-dim list + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray([1, 2, 3, 4], (2, 2)) + >>> a + [[1, 2], [3, 4]] + >>> b = a.tolist() + >>> b + [[1, 2], [3, 4]] + """ + + def f(sh, shape_left, i, j): + if len(shape_left) == 1: + return [self[self._get_tuple_index(e)] for e in range(i, j)] + result = [] + sh //= shape_left[0] + for e in range(shape_left[0]): + result.append(f(sh, shape_left[1:], i+e*sh, i+(e+1)*sh)) + return result + + return f(self._loop_size, self.shape, 0, self._loop_size) + + def __add__(self, other): + from sympy.tensor.array.arrayop import Flatten + + if not isinstance(other, NDimArray): + return NotImplemented + + if self.shape != other.shape: + raise ValueError("array shape mismatch") + result_list = [i+j for i,j in zip(Flatten(self), Flatten(other))] + + return type(self)(result_list, self.shape) + + def __sub__(self, other): + from sympy.tensor.array.arrayop import Flatten + + if not isinstance(other, NDimArray): + return NotImplemented + + if self.shape != other.shape: + raise ValueError("array shape mismatch") + result_list = [i-j for i,j in zip(Flatten(self), Flatten(other))] + + return type(self)(result_list, self.shape) + + def __mul__(self, other): + from sympy.matrices.matrixbase import MatrixBase + from sympy.tensor.array import SparseNDimArray + from sympy.tensor.array.arrayop import Flatten + + if isinstance(other, (Iterable, NDimArray, MatrixBase)): + raise ValueError("scalar expected, use tensorproduct(...) for tensorial product") + + other = sympify(other) + if isinstance(self, SparseNDimArray): + if other.is_zero: + return type(self)({}, self.shape) + return type(self)({k: other*v for (k, v) in self._sparse_array.items()}, self.shape) + + result_list = [i*other for i in Flatten(self)] + return type(self)(result_list, self.shape) + + def __rmul__(self, other): + from sympy.matrices.matrixbase import MatrixBase + from sympy.tensor.array import SparseNDimArray + from sympy.tensor.array.arrayop import Flatten + + if isinstance(other, (Iterable, NDimArray, MatrixBase)): + raise ValueError("scalar expected, use tensorproduct(...) for tensorial product") + + other = sympify(other) + if isinstance(self, SparseNDimArray): + if other.is_zero: + return type(self)({}, self.shape) + return type(self)({k: other*v for (k, v) in self._sparse_array.items()}, self.shape) + + result_list = [other*i for i in Flatten(self)] + return type(self)(result_list, self.shape) + + def __truediv__(self, other): + from sympy.matrices.matrixbase import MatrixBase + from sympy.tensor.array import SparseNDimArray + from sympy.tensor.array.arrayop import Flatten + + if isinstance(other, (Iterable, NDimArray, MatrixBase)): + raise ValueError("scalar expected") + + other = sympify(other) + if isinstance(self, SparseNDimArray) and other != S.Zero: + return type(self)({k: v/other for (k, v) in self._sparse_array.items()}, self.shape) + + result_list = [i/other for i in Flatten(self)] + return type(self)(result_list, self.shape) + + def __rtruediv__(self, other): + raise NotImplementedError('unsupported operation on NDimArray') + + def __neg__(self): + from sympy.tensor.array import SparseNDimArray + from sympy.tensor.array.arrayop import Flatten + + if isinstance(self, SparseNDimArray): + return type(self)({k: -v for (k, v) in self._sparse_array.items()}, self.shape) + + result_list = [-i for i in Flatten(self)] + return type(self)(result_list, self.shape) + + def __iter__(self): + def iterator(): + if self._shape: + for i in range(self._shape[0]): + yield self[i] + else: + yield self[()] + + return iterator() + + def __eq__(self, other): + """ + NDimArray instances can be compared to each other. + Instances equal if they have same shape and data. + + Examples + ======== + + >>> from sympy import MutableDenseNDimArray + >>> a = MutableDenseNDimArray.zeros(2, 3) + >>> b = MutableDenseNDimArray.zeros(2, 3) + >>> a == b + True + >>> c = a.reshape(3, 2) + >>> c == b + False + >>> a[0,0] = 1 + >>> b[0,0] = 2 + >>> a == b + False + """ + from sympy.tensor.array import SparseNDimArray + if not isinstance(other, NDimArray): + return False + + if not self.shape == other.shape: + return False + + if isinstance(self, SparseNDimArray) and isinstance(other, SparseNDimArray): + return dict(self._sparse_array) == dict(other._sparse_array) + + return list(self) == list(other) + + def __ne__(self, other): + return not self == other + + def _eval_transpose(self): + if self.rank() != 2: + raise ValueError("array rank not 2") + from .arrayop import permutedims + return permutedims(self, (1, 0)) + + def transpose(self): + return self._eval_transpose() + + def _eval_conjugate(self): + from sympy.tensor.array.arrayop import Flatten + + return self.func([i.conjugate() for i in Flatten(self)], self.shape) + + def conjugate(self): + return self._eval_conjugate() + + def _eval_adjoint(self): + return self.transpose().conjugate() + + def adjoint(self): + return self._eval_adjoint() + + def _slice_expand(self, s, dim): + if not isinstance(s, slice): + return (s,) + start, stop, step = s.indices(dim) + return [start + i*step for i in range((stop-start)//step)] + + def _get_slice_data_for_array_access(self, index): + sl_factors = [self._slice_expand(i, dim) for (i, dim) in zip(index, self.shape)] + eindices = itertools.product(*sl_factors) + return sl_factors, eindices + + def _get_slice_data_for_array_assignment(self, index, value): + if not isinstance(value, NDimArray): + value = type(self)(value) + sl_factors, eindices = self._get_slice_data_for_array_access(index) + slice_offsets = [min(i) if isinstance(i, list) else None for i in sl_factors] + # TODO: add checks for dimensions for `value`? + return value, eindices, slice_offsets + + @classmethod + def _check_special_bounds(cls, flat_list, shape): + if shape == () and len(flat_list) != 1: + raise ValueError("arrays without shape need one scalar value") + if shape == (0,) and len(flat_list) > 0: + raise ValueError("if array shape is (0,) there cannot be elements") + + def _check_index_for_getitem(self, index): + if isinstance(index, (SYMPY_INTS, Integer, slice)): + index = (index,) + + if len(index) < self.rank(): + index = tuple(index) + \ + tuple(slice(None) for i in range(len(index), self.rank())) + + if len(index) > self.rank(): + raise ValueError('Dimension of index greater than rank of array') + + return index + + +class ImmutableNDimArray(NDimArray, Basic): + _op_priority = 11.0 + + def __hash__(self): + return Basic.__hash__(self) + + def as_immutable(self): + return self + + def as_mutable(self): + raise NotImplementedError("abstract method") diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/sparse_ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/sparse_ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..f11aa95be8ec9d10a9104d48fb28f406fe43845e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/sparse_ndim_array.py @@ -0,0 +1,196 @@ +from sympy.core.basic import Basic +from sympy.core.containers import (Dict, Tuple) +from sympy.core.singleton import S +from sympy.core.sympify import _sympify +from sympy.tensor.array.mutable_ndim_array import MutableNDimArray +from sympy.tensor.array.ndim_array import NDimArray, ImmutableNDimArray +from sympy.utilities.iterables import flatten + +import functools + +class SparseNDimArray(NDimArray): + + def __new__(self, *args, **kwargs): + return ImmutableSparseNDimArray(*args, **kwargs) + + def __getitem__(self, index): + """ + Get an element from a sparse N-dim array. + + Examples + ======== + + >>> from sympy import MutableSparseNDimArray + >>> a = MutableSparseNDimArray(range(4), (2, 2)) + >>> a + [[0, 1], [2, 3]] + >>> a[0, 0] + 0 + >>> a[1, 1] + 3 + >>> a[0] + [0, 1] + >>> a[1] + [2, 3] + + Symbolic indexing: + + >>> from sympy.abc import i, j + >>> a[i, j] + [[0, 1], [2, 3]][i, j] + + Replace `i` and `j` to get element `(0, 0)`: + + >>> a[i, j].subs({i: 0, j: 0}) + 0 + + """ + syindex = self._check_symbolic_index(index) + if syindex is not None: + return syindex + + index = self._check_index_for_getitem(index) + + # `index` is a tuple with one or more slices: + if isinstance(index, tuple) and any(isinstance(i, slice) for i in index): + sl_factors, eindices = self._get_slice_data_for_array_access(index) + array = [self._sparse_array.get(self._parse_index(i), S.Zero) for i in eindices] + nshape = [len(el) for i, el in enumerate(sl_factors) if isinstance(index[i], slice)] + return type(self)(array, nshape) + else: + index = self._parse_index(index) + return self._sparse_array.get(index, S.Zero) + + @classmethod + def zeros(cls, *shape): + """ + Return a sparse N-dim array of zeros. + """ + return cls({}, shape) + + def tomatrix(self): + """ + Converts MutableDenseNDimArray to Matrix. Can convert only 2-dim array, else will raise error. + + Examples + ======== + + >>> from sympy import MutableSparseNDimArray + >>> a = MutableSparseNDimArray([1 for i in range(9)], (3, 3)) + >>> b = a.tomatrix() + >>> b + Matrix([ + [1, 1, 1], + [1, 1, 1], + [1, 1, 1]]) + """ + from sympy.matrices import SparseMatrix + if self.rank() != 2: + raise ValueError('Dimensions must be of size of 2') + + mat_sparse = {} + for key, value in self._sparse_array.items(): + mat_sparse[self._get_tuple_index(key)] = value + + return SparseMatrix(self.shape[0], self.shape[1], mat_sparse) + + def reshape(self, *newshape): + new_total_size = functools.reduce(lambda x,y: x*y, newshape) + if new_total_size != self._loop_size: + raise ValueError("Invalid reshape parameters " + newshape) + + return type(self)(self._sparse_array, newshape) + +class ImmutableSparseNDimArray(SparseNDimArray, ImmutableNDimArray): # type: ignore + + def __new__(cls, iterable=None, shape=None, **kwargs): + shape, flat_list = cls._handle_ndarray_creation_inputs(iterable, shape, **kwargs) + shape = Tuple(*map(_sympify, shape)) + cls._check_special_bounds(flat_list, shape) + loop_size = functools.reduce(lambda x,y: x*y, shape) if shape else len(flat_list) + + # Sparse array: + if isinstance(flat_list, (dict, Dict)): + sparse_array = Dict(flat_list) + else: + sparse_array = {} + for i, el in enumerate(flatten(flat_list)): + if el != 0: + sparse_array[i] = _sympify(el) + + sparse_array = Dict(sparse_array) + + self = Basic.__new__(cls, sparse_array, shape, **kwargs) + self._shape = shape + self._rank = len(shape) + self._loop_size = loop_size + self._sparse_array = sparse_array + + return self + + def __setitem__(self, index, value): + raise TypeError("immutable N-dim array") + + def as_mutable(self): + return MutableSparseNDimArray(self) + + +class MutableSparseNDimArray(MutableNDimArray, SparseNDimArray): + + def __new__(cls, iterable=None, shape=None, **kwargs): + shape, flat_list = cls._handle_ndarray_creation_inputs(iterable, shape, **kwargs) + self = object.__new__(cls) + self._shape = shape + self._rank = len(shape) + self._loop_size = functools.reduce(lambda x,y: x*y, shape) if shape else len(flat_list) + + # Sparse array: + if isinstance(flat_list, (dict, Dict)): + self._sparse_array = dict(flat_list) + return self + + self._sparse_array = {} + + for i, el in enumerate(flatten(flat_list)): + if el != 0: + self._sparse_array[i] = _sympify(el) + + return self + + def __setitem__(self, index, value): + """Allows to set items to MutableDenseNDimArray. + + Examples + ======== + + >>> from sympy import MutableSparseNDimArray + >>> a = MutableSparseNDimArray.zeros(2, 2) + >>> a[0, 0] = 1 + >>> a[1, 1] = 1 + >>> a + [[1, 0], [0, 1]] + """ + if isinstance(index, tuple) and any(isinstance(i, slice) for i in index): + value, eindices, slice_offsets = self._get_slice_data_for_array_assignment(index, value) + for i in eindices: + other_i = [ind - j for ind, j in zip(i, slice_offsets) if j is not None] + other_value = value[other_i] + complete_index = self._parse_index(i) + if other_value != 0: + self._sparse_array[complete_index] = other_value + elif complete_index in self._sparse_array: + self._sparse_array.pop(complete_index) + else: + index = self._parse_index(index) + value = _sympify(value) + if value == 0 and index in self._sparse_array: + self._sparse_array.pop(index) + else: + self._sparse_array[index] = value + + def as_immutable(self): + return ImmutableSparseNDimArray(self) + + @property + def free_symbols(self): + return {i for j in self._sparse_array.values() for i in j.free_symbols} diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_array_comprehension.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_array_comprehension.py new file mode 100644 index 0000000000000000000000000000000000000000..510e068f287fa04419712e5e9a16a314e522a62d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_array_comprehension.py @@ -0,0 +1,78 @@ +from sympy.tensor.array.array_comprehension import ArrayComprehension, ArrayComprehensionMap +from sympy.tensor.array import ImmutableDenseNDimArray +from sympy.abc import i, j, k, l +from sympy.testing.pytest import raises +from sympy.matrices import Matrix + + +def test_array_comprehension(): + a = ArrayComprehension(i*j, (i, 1, 3), (j, 2, 4)) + b = ArrayComprehension(i, (i, 1, j+1)) + c = ArrayComprehension(i+j+k+l, (i, 1, 2), (j, 1, 3), (k, 1, 4), (l, 1, 5)) + d = ArrayComprehension(k, (i, 1, 5)) + e = ArrayComprehension(i, (j, k+1, k+5)) + assert a.doit().tolist() == [[2, 3, 4], [4, 6, 8], [6, 9, 12]] + assert a.shape == (3, 3) + assert a.is_shape_numeric == True + assert a.tolist() == [[2, 3, 4], [4, 6, 8], [6, 9, 12]] + assert a.tomatrix() == Matrix([ + [2, 3, 4], + [4, 6, 8], + [6, 9, 12]]) + assert len(a) == 9 + assert isinstance(b.doit(), ArrayComprehension) + assert isinstance(a.doit(), ImmutableDenseNDimArray) + assert b.subs(j, 3) == ArrayComprehension(i, (i, 1, 4)) + assert b.free_symbols == {j} + assert b.shape == (j + 1,) + assert b.rank() == 1 + assert b.is_shape_numeric == False + assert c.free_symbols == set() + assert c.function == i + j + k + l + assert c.limits == ((i, 1, 2), (j, 1, 3), (k, 1, 4), (l, 1, 5)) + assert c.doit().tolist() == [[[[4, 5, 6, 7, 8], [5, 6, 7, 8, 9], [6, 7, 8, 9, 10], [7, 8, 9, 10, 11]], + [[5, 6, 7, 8, 9], [6, 7, 8, 9, 10], [7, 8, 9, 10, 11], [8, 9, 10, 11, 12]], + [[6, 7, 8, 9, 10], [7, 8, 9, 10, 11], [8, 9, 10, 11, 12], [9, 10, 11, 12, 13]]], + [[[5, 6, 7, 8, 9], [6, 7, 8, 9, 10], [7, 8, 9, 10, 11], [8, 9, 10, 11, 12]], + [[6, 7, 8, 9, 10], [7, 8, 9, 10, 11], [8, 9, 10, 11, 12], [9, 10, 11, 12, 13]], + [[7, 8, 9, 10, 11], [8, 9, 10, 11, 12], [9, 10, 11, 12, 13], [10, 11, 12, 13, 14]]]] + assert c.free_symbols == set() + assert c.variables == [i, j, k, l] + assert c.bound_symbols == [i, j, k, l] + assert d.doit().tolist() == [k, k, k, k, k] + assert len(e) == 5 + raises(TypeError, lambda: ArrayComprehension(i*j, (i, 1, 3), (j, 2, [1, 3, 2]))) + raises(ValueError, lambda: ArrayComprehension(i*j, (i, 1, 3), (j, 2, 1))) + raises(ValueError, lambda: ArrayComprehension(i*j, (i, 1, 3), (j, 2, j+1))) + raises(ValueError, lambda: len(ArrayComprehension(i*j, (i, 1, 3), (j, 2, j+4)))) + raises(TypeError, lambda: ArrayComprehension(i*j, (i, 0, i + 1.5), (j, 0, 2))) + raises(ValueError, lambda: b.tolist()) + raises(ValueError, lambda: b.tomatrix()) + raises(ValueError, lambda: c.tomatrix()) + +def test_arraycomprehensionmap(): + a = ArrayComprehensionMap(lambda i: i+1, (i, 1, 5)) + assert a.doit().tolist() == [2, 3, 4, 5, 6] + assert a.shape == (5,) + assert a.is_shape_numeric + assert a.tolist() == [2, 3, 4, 5, 6] + assert len(a) == 5 + assert isinstance(a.doit(), ImmutableDenseNDimArray) + expr = ArrayComprehensionMap(lambda i: i+1, (i, 1, k)) + assert expr.doit() == expr + assert expr.subs(k, 4) == ArrayComprehensionMap(lambda i: i+1, (i, 1, 4)) + assert expr.subs(k, 4).doit() == ImmutableDenseNDimArray([2, 3, 4, 5]) + b = ArrayComprehensionMap(lambda i: i+1, (i, 1, 2), (i, 1, 3), (i, 1, 4), (i, 1, 5)) + assert b.doit().tolist() == [[[[2, 3, 4, 5, 6], [3, 5, 7, 9, 11], [4, 7, 10, 13, 16], [5, 9, 13, 17, 21]], + [[3, 5, 7, 9, 11], [5, 9, 13, 17, 21], [7, 13, 19, 25, 31], [9, 17, 25, 33, 41]], + [[4, 7, 10, 13, 16], [7, 13, 19, 25, 31], [10, 19, 28, 37, 46], [13, 25, 37, 49, 61]]], + [[[3, 5, 7, 9, 11], [5, 9, 13, 17, 21], [7, 13, 19, 25, 31], [9, 17, 25, 33, 41]], + [[5, 9, 13, 17, 21], [9, 17, 25, 33, 41], [13, 25, 37, 49, 61], [17, 33, 49, 65, 81]], + [[7, 13, 19, 25, 31], [13, 25, 37, 49, 61], [19, 37, 55, 73, 91], [25, 49, 73, 97, 121]]]] + + # tests about lambda expression + assert ArrayComprehensionMap(lambda: 3, (i, 1, 5)).doit().tolist() == [3, 3, 3, 3, 3] + assert ArrayComprehensionMap(lambda i: i+1, (i, 1, 5)).doit().tolist() == [2, 3, 4, 5, 6] + raises(ValueError, lambda: ArrayComprehensionMap(i*j, (i, 1, 3), (j, 2, 4))) + a = ArrayComprehensionMap(lambda i, j: i+j, (i, 1, 5)) + raises(ValueError, lambda: a.doit()) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_array_derivatives.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_array_derivatives.py new file mode 100644 index 0000000000000000000000000000000000000000..7f6c777c55a9170704f309bf74387d140bf2ec32 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_array_derivatives.py @@ -0,0 +1,52 @@ +from sympy.core.symbol import symbols +from sympy.matrices.dense import Matrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.tensor.array.ndim_array import NDimArray +from sympy.matrices.matrixbase import MatrixBase +from sympy.tensor.array.array_derivatives import ArrayDerivative + +x, y, z, t = symbols("x y z t") + +m = Matrix([[x, y], [z, t]]) + +M = MatrixSymbol("M", 3, 2) +N = MatrixSymbol("N", 4, 3) + + +def test_array_derivative_construction(): + + d = ArrayDerivative(x, m, evaluate=False) + assert d.shape == (2, 2) + expr = d.doit() + assert isinstance(expr, MatrixBase) + assert expr.shape == (2, 2) + + d = ArrayDerivative(m, m, evaluate=False) + assert d.shape == (2, 2, 2, 2) + expr = d.doit() + assert isinstance(expr, NDimArray) + assert expr.shape == (2, 2, 2, 2) + + d = ArrayDerivative(m, x, evaluate=False) + assert d.shape == (2, 2) + expr = d.doit() + assert isinstance(expr, MatrixBase) + assert expr.shape == (2, 2) + + d = ArrayDerivative(M, N, evaluate=False) + assert d.shape == (4, 3, 3, 2) + expr = d.doit() + assert isinstance(expr, ArrayDerivative) + assert expr.shape == (4, 3, 3, 2) + + d = ArrayDerivative(M, (N, 2), evaluate=False) + assert d.shape == (4, 3, 4, 3, 3, 2) + expr = d.doit() + assert isinstance(expr, ArrayDerivative) + assert expr.shape == (4, 3, 4, 3, 3, 2) + + d = ArrayDerivative(M.as_explicit(), (N.as_explicit(), 2), evaluate=False) + assert d.doit().shape == (4, 3, 4, 3, 3, 2) + expr = d.doit() + assert isinstance(expr, NDimArray) + assert expr.shape == (4, 3, 4, 3, 3, 2) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_arrayop.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_arrayop.py new file mode 100644 index 0000000000000000000000000000000000000000..de56e81e0064f1e303a7a58e41932d15f2d0b41e --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_arrayop.py @@ -0,0 +1,361 @@ +import itertools +import random + +from sympy.combinatorics import Permutation +from sympy.combinatorics.permutations import _af_invert +from sympy.testing.pytest import raises + +from sympy.core.function import diff +from sympy.core.symbol import symbols +from sympy.functions.elementary.complexes import (adjoint, conjugate, transpose) +from sympy.functions.elementary.exponential import (exp, log) +from sympy.functions.elementary.trigonometric import (cos, sin) +from sympy.tensor.array import Array, ImmutableDenseNDimArray, ImmutableSparseNDimArray, MutableSparseNDimArray + +from sympy.tensor.array.arrayop import tensorproduct, tensorcontraction, derive_by_array, permutedims, Flatten, \ + tensordiagonal + + +def test_import_NDimArray(): + from sympy.tensor.array import NDimArray + del NDimArray + + +def test_tensorproduct(): + x,y,z,t = symbols('x y z t') + from sympy.abc import a,b,c,d + assert tensorproduct() == 1 + assert tensorproduct([x]) == Array([x]) + assert tensorproduct([x], [y]) == Array([[x*y]]) + assert tensorproduct([x], [y], [z]) == Array([[[x*y*z]]]) + assert tensorproduct([x], [y], [z], [t]) == Array([[[[x*y*z*t]]]]) + + assert tensorproduct(x) == x + assert tensorproduct(x, y) == x*y + assert tensorproduct(x, y, z) == x*y*z + assert tensorproduct(x, y, z, t) == x*y*z*t + + for ArrayType in [ImmutableDenseNDimArray, ImmutableSparseNDimArray]: + A = ArrayType([x, y]) + B = ArrayType([1, 2, 3]) + C = ArrayType([a, b, c, d]) + + assert tensorproduct(A, B, C) == ArrayType([[[a*x, b*x, c*x, d*x], [2*a*x, 2*b*x, 2*c*x, 2*d*x], [3*a*x, 3*b*x, 3*c*x, 3*d*x]], + [[a*y, b*y, c*y, d*y], [2*a*y, 2*b*y, 2*c*y, 2*d*y], [3*a*y, 3*b*y, 3*c*y, 3*d*y]]]) + + assert tensorproduct([x, y], [1, 2, 3]) == tensorproduct(A, B) + + assert tensorproduct(A, 2) == ArrayType([2*x, 2*y]) + assert tensorproduct(A, [2]) == ArrayType([[2*x], [2*y]]) + assert tensorproduct([2], A) == ArrayType([[2*x, 2*y]]) + assert tensorproduct(a, A) == ArrayType([a*x, a*y]) + assert tensorproduct(a, A, B) == ArrayType([[a*x, 2*a*x, 3*a*x], [a*y, 2*a*y, 3*a*y]]) + assert tensorproduct(A, B, a) == ArrayType([[a*x, 2*a*x, 3*a*x], [a*y, 2*a*y, 3*a*y]]) + assert tensorproduct(B, a, A) == ArrayType([[a*x, a*y], [2*a*x, 2*a*y], [3*a*x, 3*a*y]]) + + # tests for large scale sparse array + for SparseArrayType in [ImmutableSparseNDimArray, MutableSparseNDimArray]: + a = SparseArrayType({1:2, 3:4},(1000, 2000)) + b = SparseArrayType({1:2, 3:4},(1000, 2000)) + assert tensorproduct(a, b) == ImmutableSparseNDimArray({2000001: 4, 2000003: 8, 6000001: 8, 6000003: 16}, (1000, 2000, 1000, 2000)) + + +def test_tensorcontraction(): + from sympy.abc import a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x + B = Array(range(18), (2, 3, 3)) + assert tensorcontraction(B, (1, 2)) == Array([12, 39]) + C1 = Array([a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x], (2, 3, 2, 2)) + + assert tensorcontraction(C1, (0, 2)) == Array([[a + o, b + p], [e + s, f + t], [i + w, j + x]]) + assert tensorcontraction(C1, (0, 2, 3)) == Array([a + p, e + t, i + x]) + assert tensorcontraction(C1, (2, 3)) == Array([[a + d, e + h, i + l], [m + p, q + t, u + x]]) + + +def test_derivative_by_array(): + from sympy.abc import i, j, t, x, y, z + + bexpr = x*y**2*exp(z)*log(t) + sexpr = sin(bexpr) + cexpr = cos(bexpr) + + a = Array([sexpr]) + + assert derive_by_array(sexpr, t) == x*y**2*exp(z)*cos(x*y**2*exp(z)*log(t))/t + assert derive_by_array(sexpr, [x, y, z]) == Array([bexpr/x*cexpr, 2*y*bexpr/y**2*cexpr, bexpr*cexpr]) + assert derive_by_array(a, [x, y, z]) == Array([[bexpr/x*cexpr], [2*y*bexpr/y**2*cexpr], [bexpr*cexpr]]) + + assert derive_by_array(sexpr, [[x, y], [z, t]]) == Array([[bexpr/x*cexpr, 2*y*bexpr/y**2*cexpr], [bexpr*cexpr, bexpr/log(t)/t*cexpr]]) + assert derive_by_array(a, [[x, y], [z, t]]) == Array([[[bexpr/x*cexpr], [2*y*bexpr/y**2*cexpr]], [[bexpr*cexpr], [bexpr/log(t)/t*cexpr]]]) + assert derive_by_array([[x, y], [z, t]], [x, y]) == Array([[[1, 0], [0, 0]], [[0, 1], [0, 0]]]) + assert derive_by_array([[x, y], [z, t]], [[x, y], [z, t]]) == Array([[[[1, 0], [0, 0]], [[0, 1], [0, 0]]], + [[[0, 0], [1, 0]], [[0, 0], [0, 1]]]]) + + assert diff(sexpr, t) == x*y**2*exp(z)*cos(x*y**2*exp(z)*log(t))/t + assert diff(sexpr, Array([x, y, z])) == Array([bexpr/x*cexpr, 2*y*bexpr/y**2*cexpr, bexpr*cexpr]) + assert diff(a, Array([x, y, z])) == Array([[bexpr/x*cexpr], [2*y*bexpr/y**2*cexpr], [bexpr*cexpr]]) + + assert diff(sexpr, Array([[x, y], [z, t]])) == Array([[bexpr/x*cexpr, 2*y*bexpr/y**2*cexpr], [bexpr*cexpr, bexpr/log(t)/t*cexpr]]) + assert diff(a, Array([[x, y], [z, t]])) == Array([[[bexpr/x*cexpr], [2*y*bexpr/y**2*cexpr]], [[bexpr*cexpr], [bexpr/log(t)/t*cexpr]]]) + assert diff(Array([[x, y], [z, t]]), Array([x, y])) == Array([[[1, 0], [0, 0]], [[0, 1], [0, 0]]]) + assert diff(Array([[x, y], [z, t]]), Array([[x, y], [z, t]])) == Array([[[[1, 0], [0, 0]], [[0, 1], [0, 0]]], + [[[0, 0], [1, 0]], [[0, 0], [0, 1]]]]) + + # test for large scale sparse array + for SparseArrayType in [ImmutableSparseNDimArray, MutableSparseNDimArray]: + b = MutableSparseNDimArray({0:i, 1:j}, (10000, 20000)) + assert derive_by_array(b, i) == ImmutableSparseNDimArray({0: 1}, (10000, 20000)) + assert derive_by_array(b, (i, j)) == ImmutableSparseNDimArray({0: 1, 200000001: 1}, (2, 10000, 20000)) + + #https://github.com/sympy/sympy/issues/20655 + U = Array([x, y, z]) + E = 2 + assert derive_by_array(E, U) == ImmutableDenseNDimArray([0, 0, 0]) + + +def test_issue_emerged_while_discussing_10972(): + ua = Array([-1,0]) + Fa = Array([[0, 1], [-1, 0]]) + po = tensorproduct(Fa, ua, Fa, ua) + assert tensorcontraction(po, (1, 2), (4, 5)) == Array([[0, 0], [0, 1]]) + + sa = symbols('a0:144') + po = Array(sa, [2, 2, 3, 3, 2, 2]) + assert tensorcontraction(po, (0, 1), (2, 3), (4, 5)) == sa[0] + sa[108] + sa[111] + sa[124] + sa[127] + sa[140] + sa[143] + sa[16] + sa[19] + sa[3] + sa[32] + sa[35] + assert tensorcontraction(po, (0, 1, 4, 5), (2, 3)) == sa[0] + sa[111] + sa[127] + sa[143] + sa[16] + sa[32] + assert tensorcontraction(po, (0, 1), (4, 5)) == Array([[sa[0] + sa[108] + sa[111] + sa[3], sa[112] + sa[115] + sa[4] + sa[7], + sa[11] + sa[116] + sa[119] + sa[8]], [sa[12] + sa[120] + sa[123] + sa[15], + sa[124] + sa[127] + sa[16] + sa[19], sa[128] + sa[131] + sa[20] + sa[23]], + [sa[132] + sa[135] + sa[24] + sa[27], sa[136] + sa[139] + sa[28] + sa[31], + sa[140] + sa[143] + sa[32] + sa[35]]]) + assert tensorcontraction(po, (0, 1), (2, 3)) == Array([[sa[0] + sa[108] + sa[124] + sa[140] + sa[16] + sa[32], sa[1] + sa[109] + sa[125] + sa[141] + sa[17] + sa[33]], + [sa[110] + sa[126] + sa[142] + sa[18] + sa[2] + sa[34], sa[111] + sa[127] + sa[143] + sa[19] + sa[3] + sa[35]]]) + + +def test_array_permutedims(): + sa = symbols('a0:144') + + for ArrayType in [ImmutableDenseNDimArray, ImmutableSparseNDimArray]: + m1 = ArrayType(sa[:6], (2, 3)) + assert permutedims(m1, (1, 0)) == transpose(m1) + assert m1.tomatrix().T == permutedims(m1, (1, 0)).tomatrix() + + assert m1.tomatrix().T == transpose(m1).tomatrix() + assert m1.tomatrix().C == conjugate(m1).tomatrix() + assert m1.tomatrix().H == adjoint(m1).tomatrix() + + assert m1.tomatrix().T == m1.transpose().tomatrix() + assert m1.tomatrix().C == m1.conjugate().tomatrix() + assert m1.tomatrix().H == m1.adjoint().tomatrix() + + raises(ValueError, lambda: permutedims(m1, (0,))) + raises(ValueError, lambda: permutedims(m1, (0, 0))) + raises(ValueError, lambda: permutedims(m1, (1, 2, 0))) + + # Some tests with random arrays: + dims = 6 + shape = [random.randint(1,5) for i in range(dims)] + elems = [random.random() for i in range(tensorproduct(*shape))] + ra = ArrayType(elems, shape) + perm = list(range(dims)) + # Randomize the permutation: + random.shuffle(perm) + # Test inverse permutation: + assert permutedims(permutedims(ra, perm), _af_invert(perm)) == ra + # Test that permuted shape corresponds to action by `Permutation`: + assert permutedims(ra, perm).shape == tuple(Permutation(perm)(shape)) + + z = ArrayType.zeros(4,5,6,7) + + assert permutedims(z, (2, 3, 1, 0)).shape == (6, 7, 5, 4) + assert permutedims(z, [2, 3, 1, 0]).shape == (6, 7, 5, 4) + assert permutedims(z, Permutation([2, 3, 1, 0])).shape == (6, 7, 5, 4) + + po = ArrayType(sa, [2, 2, 3, 3, 2, 2]) + + raises(ValueError, lambda: permutedims(po, (1, 1))) + raises(ValueError, lambda: po.transpose()) + raises(ValueError, lambda: po.adjoint()) + + assert permutedims(po, reversed(range(po.rank()))) == ArrayType( + [[[[[[sa[0], sa[72]], [sa[36], sa[108]]], [[sa[12], sa[84]], [sa[48], sa[120]]], [[sa[24], + sa[96]], [sa[60], sa[132]]]], + [[[sa[4], sa[76]], [sa[40], sa[112]]], [[sa[16], + sa[88]], [sa[52], sa[124]]], + [[sa[28], sa[100]], [sa[64], sa[136]]]], + [[[sa[8], + sa[80]], [sa[44], sa[116]]], [[sa[20], sa[92]], [sa[56], sa[128]]], [[sa[32], + sa[104]], [sa[68], sa[140]]]]], + [[[[sa[2], sa[74]], [sa[38], sa[110]]], [[sa[14], + sa[86]], [sa[50], sa[122]]], [[sa[26], sa[98]], [sa[62], sa[134]]]], + [[[sa[6], + sa[78]], [sa[42], sa[114]]], [[sa[18], sa[90]], [sa[54], sa[126]]], [[sa[30], + sa[102]], [sa[66], sa[138]]]], + [[[sa[10], sa[82]], [sa[46], sa[118]]], [[sa[22], + sa[94]], [sa[58], sa[130]]], + [[sa[34], sa[106]], [sa[70], sa[142]]]]]], + [[[[[sa[1], + sa[73]], [sa[37], sa[109]]], [[sa[13], sa[85]], [sa[49], sa[121]]], [[sa[25], + sa[97]], [sa[61], sa[133]]]], + [[[sa[5], sa[77]], [sa[41], sa[113]]], [[sa[17], + sa[89]], [sa[53], sa[125]]], + [[sa[29], sa[101]], [sa[65], sa[137]]]], + [[[sa[9], + sa[81]], [sa[45], sa[117]]], [[sa[21], sa[93]], [sa[57], sa[129]]], [[sa[33], + sa[105]], [sa[69], sa[141]]]]], + [[[[sa[3], sa[75]], [sa[39], sa[111]]], [[sa[15], + sa[87]], [sa[51], sa[123]]], [[sa[27], sa[99]], [sa[63], sa[135]]]], + [[[sa[7], + sa[79]], [sa[43], sa[115]]], [[sa[19], sa[91]], [sa[55], sa[127]]], [[sa[31], + sa[103]], [sa[67], sa[139]]]], + [[[sa[11], sa[83]], [sa[47], sa[119]]], [[sa[23], + sa[95]], [sa[59], sa[131]]], + [[sa[35], sa[107]], [sa[71], sa[143]]]]]]]) + + assert permutedims(po, (1, 0, 2, 3, 4, 5)) == ArrayType( + [[[[[[sa[0], sa[1]], [sa[2], sa[3]]], [[sa[4], sa[5]], [sa[6], sa[7]]], [[sa[8], sa[9]], [sa[10], + sa[11]]]], + [[[sa[12], sa[13]], [sa[14], sa[15]]], [[sa[16], sa[17]], [sa[18], + sa[19]]], [[sa[20], sa[21]], [sa[22], sa[23]]]], + [[[sa[24], sa[25]], [sa[26], + sa[27]]], [[sa[28], sa[29]], [sa[30], sa[31]]], [[sa[32], sa[33]], [sa[34], + sa[35]]]]], + [[[[sa[72], sa[73]], [sa[74], sa[75]]], [[sa[76], sa[77]], [sa[78], + sa[79]]], [[sa[80], sa[81]], [sa[82], sa[83]]]], + [[[sa[84], sa[85]], [sa[86], + sa[87]]], [[sa[88], sa[89]], [sa[90], sa[91]]], [[sa[92], sa[93]], [sa[94], + sa[95]]]], + [[[sa[96], sa[97]], [sa[98], sa[99]]], [[sa[100], sa[101]], [sa[102], + sa[103]]], + [[sa[104], sa[105]], [sa[106], sa[107]]]]]], [[[[[sa[36], sa[37]], [sa[38], + sa[39]]], + [[sa[40], sa[41]], [sa[42], sa[43]]], + [[sa[44], sa[45]], [sa[46], + sa[47]]]], + [[[sa[48], sa[49]], [sa[50], sa[51]]], + [[sa[52], sa[53]], [sa[54], + sa[55]]], + [[sa[56], sa[57]], [sa[58], sa[59]]]], + [[[sa[60], sa[61]], [sa[62], + sa[63]]], + [[sa[64], sa[65]], [sa[66], sa[67]]], + [[sa[68], sa[69]], [sa[70], + sa[71]]]]], [ + [[[sa[108], sa[109]], [sa[110], sa[111]]], + [[sa[112], sa[113]], [sa[114], + sa[115]]], + [[sa[116], sa[117]], [sa[118], sa[119]]]], + [[[sa[120], sa[121]], [sa[122], + sa[123]]], + [[sa[124], sa[125]], [sa[126], sa[127]]], + [[sa[128], sa[129]], [sa[130], + sa[131]]]], + [[[sa[132], sa[133]], [sa[134], sa[135]]], + [[sa[136], sa[137]], [sa[138], + sa[139]]], + [[sa[140], sa[141]], [sa[142], sa[143]]]]]]]) + + assert permutedims(po, (0, 2, 1, 4, 3, 5)) == ArrayType( + [[[[[[sa[0], sa[1]], [sa[4], sa[5]], [sa[8], sa[9]]], [[sa[2], sa[3]], [sa[6], sa[7]], [sa[10], + sa[11]]]], + [[[sa[36], sa[37]], [sa[40], sa[41]], [sa[44], sa[45]]], [[sa[38], + sa[39]], [sa[42], sa[43]], [sa[46], sa[47]]]]], + [[[[sa[12], sa[13]], [sa[16], + sa[17]], [sa[20], sa[21]]], [[sa[14], sa[15]], [sa[18], sa[19]], [sa[22], + sa[23]]]], + [[[sa[48], sa[49]], [sa[52], sa[53]], [sa[56], sa[57]]], [[sa[50], + sa[51]], [sa[54], sa[55]], [sa[58], sa[59]]]]], + [[[[sa[24], sa[25]], [sa[28], + sa[29]], [sa[32], sa[33]]], [[sa[26], sa[27]], [sa[30], sa[31]], [sa[34], + sa[35]]]], + [[[sa[60], sa[61]], [sa[64], sa[65]], [sa[68], sa[69]]], [[sa[62], + sa[63]], [sa[66], sa[67]], [sa[70], sa[71]]]]]], + [[[[[sa[72], sa[73]], [sa[76], + sa[77]], [sa[80], sa[81]]], [[sa[74], sa[75]], [sa[78], sa[79]], [sa[82], + sa[83]]]], + [[[sa[108], sa[109]], [sa[112], sa[113]], [sa[116], sa[117]]], [[sa[110], + sa[111]], [sa[114], sa[115]], + [sa[118], sa[119]]]]], + [[[[sa[84], sa[85]], [sa[88], + sa[89]], [sa[92], sa[93]]], [[sa[86], sa[87]], [sa[90], sa[91]], [sa[94], + sa[95]]]], + [[[sa[120], sa[121]], [sa[124], sa[125]], [sa[128], sa[129]]], [[sa[122], + sa[123]], [sa[126], sa[127]], + [sa[130], sa[131]]]]], + [[[[sa[96], sa[97]], [sa[100], + sa[101]], [sa[104], sa[105]]], [[sa[98], sa[99]], [sa[102], sa[103]], [sa[106], + sa[107]]]], + [[[sa[132], sa[133]], [sa[136], sa[137]], [sa[140], sa[141]]], [[sa[134], + sa[135]], [sa[138], sa[139]], + [sa[142], sa[143]]]]]]]) + + po2 = po.reshape(4, 9, 2, 2) + assert po2 == ArrayType([[[[sa[0], sa[1]], [sa[2], sa[3]]], [[sa[4], sa[5]], [sa[6], sa[7]]], [[sa[8], sa[9]], [sa[10], sa[11]]], [[sa[12], sa[13]], [sa[14], sa[15]]], [[sa[16], sa[17]], [sa[18], sa[19]]], [[sa[20], sa[21]], [sa[22], sa[23]]], [[sa[24], sa[25]], [sa[26], sa[27]]], [[sa[28], sa[29]], [sa[30], sa[31]]], [[sa[32], sa[33]], [sa[34], sa[35]]]], [[[sa[36], sa[37]], [sa[38], sa[39]]], [[sa[40], sa[41]], [sa[42], sa[43]]], [[sa[44], sa[45]], [sa[46], sa[47]]], [[sa[48], sa[49]], [sa[50], sa[51]]], [[sa[52], sa[53]], [sa[54], sa[55]]], [[sa[56], sa[57]], [sa[58], sa[59]]], [[sa[60], sa[61]], [sa[62], sa[63]]], [[sa[64], sa[65]], [sa[66], sa[67]]], [[sa[68], sa[69]], [sa[70], sa[71]]]], [[[sa[72], sa[73]], [sa[74], sa[75]]], [[sa[76], sa[77]], [sa[78], sa[79]]], [[sa[80], sa[81]], [sa[82], sa[83]]], [[sa[84], sa[85]], [sa[86], sa[87]]], [[sa[88], sa[89]], [sa[90], sa[91]]], [[sa[92], sa[93]], [sa[94], sa[95]]], [[sa[96], sa[97]], [sa[98], sa[99]]], [[sa[100], sa[101]], [sa[102], sa[103]]], [[sa[104], sa[105]], [sa[106], sa[107]]]], [[[sa[108], sa[109]], [sa[110], sa[111]]], [[sa[112], sa[113]], [sa[114], sa[115]]], [[sa[116], sa[117]], [sa[118], sa[119]]], [[sa[120], sa[121]], [sa[122], sa[123]]], [[sa[124], sa[125]], [sa[126], sa[127]]], [[sa[128], sa[129]], [sa[130], sa[131]]], [[sa[132], sa[133]], [sa[134], sa[135]]], [[sa[136], sa[137]], [sa[138], sa[139]]], [[sa[140], sa[141]], [sa[142], sa[143]]]]]) + + assert permutedims(po2, (3, 2, 0, 1)) == ArrayType([[[[sa[0], sa[4], sa[8], sa[12], sa[16], sa[20], sa[24], sa[28], sa[32]], [sa[36], sa[40], sa[44], sa[48], sa[52], sa[56], sa[60], sa[64], sa[68]], [sa[72], sa[76], sa[80], sa[84], sa[88], sa[92], sa[96], sa[100], sa[104]], [sa[108], sa[112], sa[116], sa[120], sa[124], sa[128], sa[132], sa[136], sa[140]]], [[sa[2], sa[6], sa[10], sa[14], sa[18], sa[22], sa[26], sa[30], sa[34]], [sa[38], sa[42], sa[46], sa[50], sa[54], sa[58], sa[62], sa[66], sa[70]], [sa[74], sa[78], sa[82], sa[86], sa[90], sa[94], sa[98], sa[102], sa[106]], [sa[110], sa[114], sa[118], sa[122], sa[126], sa[130], sa[134], sa[138], sa[142]]]], [[[sa[1], sa[5], sa[9], sa[13], sa[17], sa[21], sa[25], sa[29], sa[33]], [sa[37], sa[41], sa[45], sa[49], sa[53], sa[57], sa[61], sa[65], sa[69]], [sa[73], sa[77], sa[81], sa[85], sa[89], sa[93], sa[97], sa[101], sa[105]], [sa[109], sa[113], sa[117], sa[121], sa[125], sa[129], sa[133], sa[137], sa[141]]], [[sa[3], sa[7], sa[11], sa[15], sa[19], sa[23], sa[27], sa[31], sa[35]], [sa[39], sa[43], sa[47], sa[51], sa[55], sa[59], sa[63], sa[67], sa[71]], [sa[75], sa[79], sa[83], sa[87], sa[91], sa[95], sa[99], sa[103], sa[107]], [sa[111], sa[115], sa[119], sa[123], sa[127], sa[131], sa[135], sa[139], sa[143]]]]]) + + # test for large scale sparse array + for SparseArrayType in [ImmutableSparseNDimArray, MutableSparseNDimArray]: + A = SparseArrayType({1:1, 10000:2}, (10000, 20000, 10000)) + assert permutedims(A, (0, 1, 2)) == A + assert permutedims(A, (1, 0, 2)) == SparseArrayType({1: 1, 100000000: 2}, (20000, 10000, 10000)) + B = SparseArrayType({1:1, 20000:2}, (10000, 20000)) + assert B.transpose() == SparseArrayType({10000: 1, 1: 2}, (20000, 10000)) + + +def test_permutedims_with_indices(): + A = Array(range(32)).reshape(2, 2, 2, 2, 2) + indices_new = list("abcde") + indices_old = list("ebdac") + new_A = permutedims(A, index_order_new=indices_new, index_order_old=indices_old) + for a, b, c, d, e in itertools.product(range(2), range(2), range(2), range(2), range(2)): + assert new_A[a, b, c, d, e] == A[e, b, d, a, c] + indices_old = list("cabed") + new_A = permutedims(A, index_order_new=indices_new, index_order_old=indices_old) + for a, b, c, d, e in itertools.product(range(2), range(2), range(2), range(2), range(2)): + assert new_A[a, b, c, d, e] == A[c, a, b, e, d] + raises(ValueError, lambda: permutedims(A, index_order_old=list("aacde"), index_order_new=list("abcde"))) + raises(ValueError, lambda: permutedims(A, index_order_old=list("abcde"), index_order_new=list("abcce"))) + raises(ValueError, lambda: permutedims(A, index_order_old=list("abcde"), index_order_new=list("abce"))) + raises(ValueError, lambda: permutedims(A, index_order_old=list("abce"), index_order_new=list("abce"))) + raises(ValueError, lambda: permutedims(A, [2, 1, 0, 3, 4], index_order_old=list("abcde"))) + raises(ValueError, lambda: permutedims(A, [2, 1, 0, 3, 4], index_order_new=list("abcde"))) + + +def test_flatten(): + from sympy.matrices.dense import Matrix + for ArrayType in [ImmutableDenseNDimArray, ImmutableSparseNDimArray, Matrix]: + A = ArrayType(range(24)).reshape(4, 6) + assert list(Flatten(A)) == [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23] + + for i, v in enumerate(Flatten(A)): + assert i == v + + +def test_tensordiagonal(): + from sympy.matrices.dense import eye + expr = Array(range(9)).reshape(3, 3) + raises(ValueError, lambda: tensordiagonal(expr, [0], [1])) + raises(ValueError, lambda: tensordiagonal(expr, [0, 0])) + assert tensordiagonal(eye(3), [0, 1]) == Array([1, 1, 1]) + assert tensordiagonal(expr, [0, 1]) == Array([0, 4, 8]) + x, y, z = symbols("x y z") + expr2 = tensorproduct([x, y, z], expr) + assert tensordiagonal(expr2, [1, 2]) == Array([[0, 4*x, 8*x], [0, 4*y, 8*y], [0, 4*z, 8*z]]) + assert tensordiagonal(expr2, [0, 1]) == Array([[0, 3*y, 6*z], [x, 4*y, 7*z], [2*x, 5*y, 8*z]]) + assert tensordiagonal(expr2, [0, 1, 2]) == Array([0, 4*y, 8*z]) + # assert tensordiagonal(expr2, [0]) == permutedims(expr2, [1, 2, 0]) + # assert tensordiagonal(expr2, [1]) == permutedims(expr2, [0, 2, 1]) + # assert tensordiagonal(expr2, [2]) == expr2 + # assert tensordiagonal(expr2, [1], [2]) == expr2 + # assert tensordiagonal(expr2, [0], [1]) == permutedims(expr2, [2, 0, 1]) + + a, b, c, X, Y, Z = symbols("a b c X Y Z") + expr3 = tensorproduct([x, y, z], [1, 2, 3], [a, b, c], [X, Y, Z]) + assert tensordiagonal(expr3, [0, 1, 2, 3]) == Array([x*a*X, 2*y*b*Y, 3*z*c*Z]) + assert tensordiagonal(expr3, [0, 1], [2, 3]) == tensorproduct([x, 2*y, 3*z], [a*X, b*Y, c*Z]) + + # assert tensordiagonal(expr3, [0], [1, 2], [3]) == tensorproduct([x, y, z], [a, 2*b, 3*c], [X, Y, Z]) + assert tensordiagonal(tensordiagonal(expr3, [2, 3]), [0, 1]) == tensorproduct([a*X, b*Y, c*Z], [x, 2*y, 3*z]) + + raises(ValueError, lambda: tensordiagonal([[1, 2, 3], [4, 5, 6]], [0, 1])) + raises(ValueError, lambda: tensordiagonal(expr3.reshape(3, 3, 9), [1, 2])) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_immutable_ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_immutable_ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..c6bed4b605c424284b4752592b03b13a9178aac8 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_immutable_ndim_array.py @@ -0,0 +1,452 @@ +from copy import copy + +from sympy.tensor.array.dense_ndim_array import ImmutableDenseNDimArray +from sympy.core.containers import Dict +from sympy.core.function import diff +from sympy.core.numbers import Rational +from sympy.core.singleton import S +from sympy.core.symbol import (Symbol, symbols) +from sympy.matrices import SparseMatrix +from sympy.tensor.indexed import (Indexed, IndexedBase) +from sympy.matrices import Matrix +from sympy.tensor.array.sparse_ndim_array import ImmutableSparseNDimArray +from sympy.testing.pytest import raises + + +def test_ndim_array_initiation(): + arr_with_no_elements = ImmutableDenseNDimArray([], shape=(0,)) + assert len(arr_with_no_elements) == 0 + assert arr_with_no_elements.rank() == 1 + + raises(ValueError, lambda: ImmutableDenseNDimArray([0], shape=(0,))) + raises(ValueError, lambda: ImmutableDenseNDimArray([1, 2, 3], shape=(0,))) + raises(ValueError, lambda: ImmutableDenseNDimArray([], shape=())) + + raises(ValueError, lambda: ImmutableSparseNDimArray([0], shape=(0,))) + raises(ValueError, lambda: ImmutableSparseNDimArray([1, 2, 3], shape=(0,))) + raises(ValueError, lambda: ImmutableSparseNDimArray([], shape=())) + + arr_with_one_element = ImmutableDenseNDimArray([23]) + assert len(arr_with_one_element) == 1 + assert arr_with_one_element[0] == 23 + assert arr_with_one_element[:] == ImmutableDenseNDimArray([23]) + assert arr_with_one_element.rank() == 1 + + arr_with_symbol_element = ImmutableDenseNDimArray([Symbol('x')]) + assert len(arr_with_symbol_element) == 1 + assert arr_with_symbol_element[0] == Symbol('x') + assert arr_with_symbol_element[:] == ImmutableDenseNDimArray([Symbol('x')]) + assert arr_with_symbol_element.rank() == 1 + + number5 = 5 + vector = ImmutableDenseNDimArray.zeros(number5) + assert len(vector) == number5 + assert vector.shape == (number5,) + assert vector.rank() == 1 + + vector = ImmutableSparseNDimArray.zeros(number5) + assert len(vector) == number5 + assert vector.shape == (number5,) + assert vector._sparse_array == Dict() + assert vector.rank() == 1 + + n_dim_array = ImmutableDenseNDimArray(range(3**4), (3, 3, 3, 3,)) + assert len(n_dim_array) == 3 * 3 * 3 * 3 + assert n_dim_array.shape == (3, 3, 3, 3) + assert n_dim_array.rank() == 4 + + array_shape = (3, 3, 3, 3) + sparse_array = ImmutableSparseNDimArray.zeros(*array_shape) + assert len(sparse_array._sparse_array) == 0 + assert len(sparse_array) == 3 * 3 * 3 * 3 + assert n_dim_array.shape == array_shape + assert n_dim_array.rank() == 4 + + one_dim_array = ImmutableDenseNDimArray([2, 3, 1]) + assert len(one_dim_array) == 3 + assert one_dim_array.shape == (3,) + assert one_dim_array.rank() == 1 + assert one_dim_array.tolist() == [2, 3, 1] + + shape = (3, 3) + array_with_many_args = ImmutableSparseNDimArray.zeros(*shape) + assert len(array_with_many_args) == 3 * 3 + assert array_with_many_args.shape == shape + assert array_with_many_args[0, 0] == 0 + assert array_with_many_args.rank() == 2 + + shape = (int(3), int(3)) + array_with_long_shape = ImmutableSparseNDimArray.zeros(*shape) + assert len(array_with_long_shape) == 3 * 3 + assert array_with_long_shape.shape == shape + assert array_with_long_shape[int(0), int(0)] == 0 + assert array_with_long_shape.rank() == 2 + + vector_with_long_shape = ImmutableDenseNDimArray(range(5), int(5)) + assert len(vector_with_long_shape) == 5 + assert vector_with_long_shape.shape == (int(5),) + assert vector_with_long_shape.rank() == 1 + raises(ValueError, lambda: vector_with_long_shape[int(5)]) + + from sympy.abc import x + for ArrayType in [ImmutableDenseNDimArray, ImmutableSparseNDimArray]: + rank_zero_array = ArrayType(x) + assert len(rank_zero_array) == 1 + assert rank_zero_array.shape == () + assert rank_zero_array.rank() == 0 + assert rank_zero_array[()] == x + raises(ValueError, lambda: rank_zero_array[0]) + + +def test_reshape(): + array = ImmutableDenseNDimArray(range(50), 50) + assert array.shape == (50,) + assert array.rank() == 1 + + array = array.reshape(5, 5, 2) + assert array.shape == (5, 5, 2) + assert array.rank() == 3 + assert len(array) == 50 + + +def test_getitem(): + for ArrayType in [ImmutableDenseNDimArray, ImmutableSparseNDimArray]: + array = ArrayType(range(24)).reshape(2, 3, 4) + assert array.tolist() == [[[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]], [[12, 13, 14, 15], [16, 17, 18, 19], [20, 21, 22, 23]]] + assert array[0] == ArrayType([[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]]) + assert array[0, 0] == ArrayType([0, 1, 2, 3]) + value = 0 + for i in range(2): + for j in range(3): + for k in range(4): + assert array[i, j, k] == value + value += 1 + + raises(ValueError, lambda: array[3, 4, 5]) + raises(ValueError, lambda: array[3, 4, 5, 6]) + raises(ValueError, lambda: array[3, 4, 5, 3:4]) + + +def test_iterator(): + array = ImmutableDenseNDimArray(range(4), (2, 2)) + assert array[0] == ImmutableDenseNDimArray([0, 1]) + assert array[1] == ImmutableDenseNDimArray([2, 3]) + + array = array.reshape(4) + j = 0 + for i in array: + assert i == j + j += 1 + + +def test_sparse(): + sparse_array = ImmutableSparseNDimArray([0, 0, 0, 1], (2, 2)) + assert len(sparse_array) == 2 * 2 + # dictionary where all data is, only non-zero entries are actually stored: + assert len(sparse_array._sparse_array) == 1 + + assert sparse_array.tolist() == [[0, 0], [0, 1]] + + for i, j in zip(sparse_array, [[0, 0], [0, 1]]): + assert i == ImmutableSparseNDimArray(j) + + def sparse_assignment(): + sparse_array[0, 0] = 123 + + assert len(sparse_array._sparse_array) == 1 + raises(TypeError, sparse_assignment) + assert len(sparse_array._sparse_array) == 1 + assert sparse_array[0, 0] == 0 + assert sparse_array/0 == ImmutableSparseNDimArray([[S.NaN, S.NaN], [S.NaN, S.ComplexInfinity]], (2, 2)) + + # test for large scale sparse array + # equality test + assert ImmutableSparseNDimArray.zeros(100000, 200000) == ImmutableSparseNDimArray.zeros(100000, 200000) + + # __mul__ and __rmul__ + a = ImmutableSparseNDimArray({200001: 1}, (100000, 200000)) + assert a * 3 == ImmutableSparseNDimArray({200001: 3}, (100000, 200000)) + assert 3 * a == ImmutableSparseNDimArray({200001: 3}, (100000, 200000)) + assert a * 0 == ImmutableSparseNDimArray({}, (100000, 200000)) + assert 0 * a == ImmutableSparseNDimArray({}, (100000, 200000)) + + # __truediv__ + assert a/3 == ImmutableSparseNDimArray({200001: Rational(1, 3)}, (100000, 200000)) + + # __neg__ + assert -a == ImmutableSparseNDimArray({200001: -1}, (100000, 200000)) + + +def test_calculation(): + + a = ImmutableDenseNDimArray([1]*9, (3, 3)) + b = ImmutableDenseNDimArray([9]*9, (3, 3)) + + c = a + b + for i in c: + assert i == ImmutableDenseNDimArray([10, 10, 10]) + + assert c == ImmutableDenseNDimArray([10]*9, (3, 3)) + assert c == ImmutableSparseNDimArray([10]*9, (3, 3)) + + c = b - a + for i in c: + assert i == ImmutableDenseNDimArray([8, 8, 8]) + + assert c == ImmutableDenseNDimArray([8]*9, (3, 3)) + assert c == ImmutableSparseNDimArray([8]*9, (3, 3)) + + +def test_ndim_array_converting(): + dense_array = ImmutableDenseNDimArray([1, 2, 3, 4], (2, 2)) + alist = dense_array.tolist() + + assert alist == [[1, 2], [3, 4]] + + matrix = dense_array.tomatrix() + assert (isinstance(matrix, Matrix)) + + for i in range(len(dense_array)): + assert dense_array[dense_array._get_tuple_index(i)] == matrix[i] + assert matrix.shape == dense_array.shape + + assert ImmutableDenseNDimArray(matrix) == dense_array + assert ImmutableDenseNDimArray(matrix.as_immutable()) == dense_array + assert ImmutableDenseNDimArray(matrix.as_mutable()) == dense_array + + sparse_array = ImmutableSparseNDimArray([1, 2, 3, 4], (2, 2)) + alist = sparse_array.tolist() + + assert alist == [[1, 2], [3, 4]] + + matrix = sparse_array.tomatrix() + assert(isinstance(matrix, SparseMatrix)) + + for i in range(len(sparse_array)): + assert sparse_array[sparse_array._get_tuple_index(i)] == matrix[i] + assert matrix.shape == sparse_array.shape + + assert ImmutableSparseNDimArray(matrix) == sparse_array + assert ImmutableSparseNDimArray(matrix.as_immutable()) == sparse_array + assert ImmutableSparseNDimArray(matrix.as_mutable()) == sparse_array + + +def test_converting_functions(): + arr_list = [1, 2, 3, 4] + arr_matrix = Matrix(((1, 2), (3, 4))) + + # list + arr_ndim_array = ImmutableDenseNDimArray(arr_list, (2, 2)) + assert (isinstance(arr_ndim_array, ImmutableDenseNDimArray)) + assert arr_matrix.tolist() == arr_ndim_array.tolist() + + # Matrix + arr_ndim_array = ImmutableDenseNDimArray(arr_matrix) + assert (isinstance(arr_ndim_array, ImmutableDenseNDimArray)) + assert arr_matrix.tolist() == arr_ndim_array.tolist() + assert arr_matrix.shape == arr_ndim_array.shape + + +def test_equality(): + first_list = [1, 2, 3, 4] + second_list = [1, 2, 3, 4] + third_list = [4, 3, 2, 1] + assert first_list == second_list + assert first_list != third_list + + first_ndim_array = ImmutableDenseNDimArray(first_list, (2, 2)) + second_ndim_array = ImmutableDenseNDimArray(second_list, (2, 2)) + fourth_ndim_array = ImmutableDenseNDimArray(first_list, (2, 2)) + + assert first_ndim_array == second_ndim_array + + def assignment_attempt(a): + a[0, 0] = 0 + + raises(TypeError, lambda: assignment_attempt(second_ndim_array)) + assert first_ndim_array == second_ndim_array + assert first_ndim_array == fourth_ndim_array + + +def test_arithmetic(): + a = ImmutableDenseNDimArray([3 for i in range(9)], (3, 3)) + b = ImmutableDenseNDimArray([7 for i in range(9)], (3, 3)) + + c1 = a + b + c2 = b + a + assert c1 == c2 + + d1 = a - b + d2 = b - a + assert d1 == d2 * (-1) + + e1 = a * 5 + e2 = 5 * a + e3 = copy(a) + e3 *= 5 + assert e1 == e2 == e3 + + f1 = a / 5 + f2 = copy(a) + f2 /= 5 + assert f1 == f2 + assert f1[0, 0] == f1[0, 1] == f1[0, 2] == f1[1, 0] == f1[1, 1] == \ + f1[1, 2] == f1[2, 0] == f1[2, 1] == f1[2, 2] == Rational(3, 5) + + assert type(a) == type(b) == type(c1) == type(c2) == type(d1) == type(d2) \ + == type(e1) == type(e2) == type(e3) == type(f1) + + z0 = -a + assert z0 == ImmutableDenseNDimArray([-3 for i in range(9)], (3, 3)) + + +def test_higher_dimenions(): + m3 = ImmutableDenseNDimArray(range(10, 34), (2, 3, 4)) + + assert m3.tolist() == [[[10, 11, 12, 13], + [14, 15, 16, 17], + [18, 19, 20, 21]], + + [[22, 23, 24, 25], + [26, 27, 28, 29], + [30, 31, 32, 33]]] + + assert m3._get_tuple_index(0) == (0, 0, 0) + assert m3._get_tuple_index(1) == (0, 0, 1) + assert m3._get_tuple_index(4) == (0, 1, 0) + assert m3._get_tuple_index(12) == (1, 0, 0) + + assert str(m3) == '[[[10, 11, 12, 13], [14, 15, 16, 17], [18, 19, 20, 21]], [[22, 23, 24, 25], [26, 27, 28, 29], [30, 31, 32, 33]]]' + + m3_rebuilt = ImmutableDenseNDimArray([[[10, 11, 12, 13], [14, 15, 16, 17], [18, 19, 20, 21]], [[22, 23, 24, 25], [26, 27, 28, 29], [30, 31, 32, 33]]]) + assert m3 == m3_rebuilt + + m3_other = ImmutableDenseNDimArray([[[10, 11, 12, 13], [14, 15, 16, 17], [18, 19, 20, 21]], [[22, 23, 24, 25], [26, 27, 28, 29], [30, 31, 32, 33]]], (2, 3, 4)) + + assert m3 == m3_other + + +def test_rebuild_immutable_arrays(): + sparr = ImmutableSparseNDimArray(range(10, 34), (2, 3, 4)) + densarr = ImmutableDenseNDimArray(range(10, 34), (2, 3, 4)) + + assert sparr == sparr.func(*sparr.args) + assert densarr == densarr.func(*densarr.args) + + +def test_slices(): + md = ImmutableDenseNDimArray(range(10, 34), (2, 3, 4)) + + assert md[:] == ImmutableDenseNDimArray(range(10, 34), (2, 3, 4)) + assert md[:, :, 0].tomatrix() == Matrix([[10, 14, 18], [22, 26, 30]]) + assert md[0, 1:2, :].tomatrix() == Matrix([[14, 15, 16, 17]]) + assert md[0, 1:3, :].tomatrix() == Matrix([[14, 15, 16, 17], [18, 19, 20, 21]]) + assert md[:, :, :] == md + + sd = ImmutableSparseNDimArray(range(10, 34), (2, 3, 4)) + assert sd == ImmutableSparseNDimArray(md) + + assert sd[:] == ImmutableSparseNDimArray(range(10, 34), (2, 3, 4)) + assert sd[:, :, 0].tomatrix() == Matrix([[10, 14, 18], [22, 26, 30]]) + assert sd[0, 1:2, :].tomatrix() == Matrix([[14, 15, 16, 17]]) + assert sd[0, 1:3, :].tomatrix() == Matrix([[14, 15, 16, 17], [18, 19, 20, 21]]) + assert sd[:, :, :] == sd + + +def test_diff_and_applyfunc(): + from sympy.abc import x, y, z + md = ImmutableDenseNDimArray([[x, y], [x*z, x*y*z]]) + assert md.diff(x) == ImmutableDenseNDimArray([[1, 0], [z, y*z]]) + assert diff(md, x) == ImmutableDenseNDimArray([[1, 0], [z, y*z]]) + + sd = ImmutableSparseNDimArray(md) + assert sd == ImmutableSparseNDimArray([x, y, x*z, x*y*z], (2, 2)) + assert sd.diff(x) == ImmutableSparseNDimArray([[1, 0], [z, y*z]]) + assert diff(sd, x) == ImmutableSparseNDimArray([[1, 0], [z, y*z]]) + + mdn = md.applyfunc(lambda x: x*3) + assert mdn == ImmutableDenseNDimArray([[3*x, 3*y], [3*x*z, 3*x*y*z]]) + assert md != mdn + + sdn = sd.applyfunc(lambda x: x/2) + assert sdn == ImmutableSparseNDimArray([[x/2, y/2], [x*z/2, x*y*z/2]]) + assert sd != sdn + + sdp = sd.applyfunc(lambda x: x+1) + assert sdp == ImmutableSparseNDimArray([[x + 1, y + 1], [x*z + 1, x*y*z + 1]]) + assert sd != sdp + + +def test_op_priority(): + from sympy.abc import x + md = ImmutableDenseNDimArray([1, 2, 3]) + e1 = (1+x)*md + e2 = md*(1+x) + assert e1 == ImmutableDenseNDimArray([1+x, 2+2*x, 3+3*x]) + assert e1 == e2 + + sd = ImmutableSparseNDimArray([1, 2, 3]) + e3 = (1+x)*sd + e4 = sd*(1+x) + assert e3 == ImmutableDenseNDimArray([1+x, 2+2*x, 3+3*x]) + assert e3 == e4 + + +def test_symbolic_indexing(): + x, y, z, w = symbols("x y z w") + M = ImmutableDenseNDimArray([[x, y], [z, w]]) + i, j = symbols("i, j") + Mij = M[i, j] + assert isinstance(Mij, Indexed) + Ms = ImmutableSparseNDimArray([[2, 3*x], [4, 5]]) + msij = Ms[i, j] + assert isinstance(msij, Indexed) + for oi, oj in [(0, 0), (0, 1), (1, 0), (1, 1)]: + assert Mij.subs({i: oi, j: oj}) == M[oi, oj] + assert msij.subs({i: oi, j: oj}) == Ms[oi, oj] + A = IndexedBase("A", (0, 2)) + assert A[0, 0].subs(A, M) == x + assert A[i, j].subs(A, M) == M[i, j] + assert M[i, j].subs(M, A) == A[i, j] + + assert isinstance(M[3 * i - 2, j], Indexed) + assert M[3 * i - 2, j].subs({i: 1, j: 0}) == M[1, 0] + assert isinstance(M[i, 0], Indexed) + assert M[i, 0].subs(i, 0) == M[0, 0] + assert M[0, i].subs(i, 1) == M[0, 1] + + assert M[i, j].diff(x) == ImmutableDenseNDimArray([[1, 0], [0, 0]])[i, j] + assert Ms[i, j].diff(x) == ImmutableSparseNDimArray([[0, 3], [0, 0]])[i, j] + + Mo = ImmutableDenseNDimArray([1, 2, 3]) + assert Mo[i].subs(i, 1) == 2 + Mos = ImmutableSparseNDimArray([1, 2, 3]) + assert Mos[i].subs(i, 1) == 2 + + raises(ValueError, lambda: M[i, 2]) + raises(ValueError, lambda: M[i, -1]) + raises(ValueError, lambda: M[2, i]) + raises(ValueError, lambda: M[-1, i]) + + raises(ValueError, lambda: Ms[i, 2]) + raises(ValueError, lambda: Ms[i, -1]) + raises(ValueError, lambda: Ms[2, i]) + raises(ValueError, lambda: Ms[-1, i]) + + +def test_issue_12665(): + # Testing Python 3 hash of immutable arrays: + arr = ImmutableDenseNDimArray([1, 2, 3]) + # This should NOT raise an exception: + hash(arr) + + +def test_zeros_without_shape(): + arr = ImmutableDenseNDimArray.zeros() + assert arr == ImmutableDenseNDimArray(0) + +def test_issue_21870(): + a0 = ImmutableDenseNDimArray(0) + assert a0.rank() == 0 + a1 = ImmutableDenseNDimArray(a0) + assert a1.rank() == 0 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_mutable_ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_mutable_ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..9a232f399bbc0639d326217975fb0a12e645a984 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_mutable_ndim_array.py @@ -0,0 +1,374 @@ +from copy import copy + +from sympy.tensor.array.dense_ndim_array import MutableDenseNDimArray +from sympy.core.function import diff +from sympy.core.numbers import Rational +from sympy.core.singleton import S +from sympy.core.symbol import Symbol +from sympy.core.sympify import sympify +from sympy.matrices import SparseMatrix +from sympy.matrices import Matrix +from sympy.tensor.array.sparse_ndim_array import MutableSparseNDimArray +from sympy.testing.pytest import raises + + +def test_ndim_array_initiation(): + arr_with_one_element = MutableDenseNDimArray([23]) + assert len(arr_with_one_element) == 1 + assert arr_with_one_element[0] == 23 + assert arr_with_one_element.rank() == 1 + raises(ValueError, lambda: arr_with_one_element[1]) + + arr_with_symbol_element = MutableDenseNDimArray([Symbol('x')]) + assert len(arr_with_symbol_element) == 1 + assert arr_with_symbol_element[0] == Symbol('x') + assert arr_with_symbol_element.rank() == 1 + + number5 = 5 + vector = MutableDenseNDimArray.zeros(number5) + assert len(vector) == number5 + assert vector.shape == (number5,) + assert vector.rank() == 1 + raises(ValueError, lambda: arr_with_one_element[5]) + + vector = MutableSparseNDimArray.zeros(number5) + assert len(vector) == number5 + assert vector.shape == (number5,) + assert vector._sparse_array == {} + assert vector.rank() == 1 + + n_dim_array = MutableDenseNDimArray(range(3**4), (3, 3, 3, 3,)) + assert len(n_dim_array) == 3 * 3 * 3 * 3 + assert n_dim_array.shape == (3, 3, 3, 3) + assert n_dim_array.rank() == 4 + raises(ValueError, lambda: n_dim_array[0, 0, 0, 3]) + raises(ValueError, lambda: n_dim_array[3, 0, 0, 0]) + raises(ValueError, lambda: n_dim_array[3**4]) + + array_shape = (3, 3, 3, 3) + sparse_array = MutableSparseNDimArray.zeros(*array_shape) + assert len(sparse_array._sparse_array) == 0 + assert len(sparse_array) == 3 * 3 * 3 * 3 + assert n_dim_array.shape == array_shape + assert n_dim_array.rank() == 4 + + one_dim_array = MutableDenseNDimArray([2, 3, 1]) + assert len(one_dim_array) == 3 + assert one_dim_array.shape == (3,) + assert one_dim_array.rank() == 1 + assert one_dim_array.tolist() == [2, 3, 1] + + shape = (3, 3) + array_with_many_args = MutableSparseNDimArray.zeros(*shape) + assert len(array_with_many_args) == 3 * 3 + assert array_with_many_args.shape == shape + assert array_with_many_args[0, 0] == 0 + assert array_with_many_args.rank() == 2 + + shape = (int(3), int(3)) + array_with_long_shape = MutableSparseNDimArray.zeros(*shape) + assert len(array_with_long_shape) == 3 * 3 + assert array_with_long_shape.shape == shape + assert array_with_long_shape[int(0), int(0)] == 0 + assert array_with_long_shape.rank() == 2 + + vector_with_long_shape = MutableDenseNDimArray(range(5), int(5)) + assert len(vector_with_long_shape) == 5 + assert vector_with_long_shape.shape == (int(5),) + assert vector_with_long_shape.rank() == 1 + raises(ValueError, lambda: vector_with_long_shape[int(5)]) + + from sympy.abc import x + for ArrayType in [MutableDenseNDimArray, MutableSparseNDimArray]: + rank_zero_array = ArrayType(x) + assert len(rank_zero_array) == 1 + assert rank_zero_array.shape == () + assert rank_zero_array.rank() == 0 + assert rank_zero_array[()] == x + raises(ValueError, lambda: rank_zero_array[0]) + +def test_sympify(): + from sympy.abc import x, y, z, t + arr = MutableDenseNDimArray([[x, y], [1, z*t]]) + arr_other = sympify(arr) + assert arr_other.shape == (2, 2) + assert arr_other == arr + + +def test_reshape(): + array = MutableDenseNDimArray(range(50), 50) + assert array.shape == (50,) + assert array.rank() == 1 + + array = array.reshape(5, 5, 2) + assert array.shape == (5, 5, 2) + assert array.rank() == 3 + assert len(array) == 50 + + +def test_iterator(): + array = MutableDenseNDimArray(range(4), (2, 2)) + assert array[0] == MutableDenseNDimArray([0, 1]) + assert array[1] == MutableDenseNDimArray([2, 3]) + + array = array.reshape(4) + j = 0 + for i in array: + assert i == j + j += 1 + + +def test_getitem(): + for ArrayType in [MutableDenseNDimArray, MutableSparseNDimArray]: + array = ArrayType(range(24)).reshape(2, 3, 4) + assert array.tolist() == [[[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]], [[12, 13, 14, 15], [16, 17, 18, 19], [20, 21, 22, 23]]] + assert array[0] == ArrayType([[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]]) + assert array[0, 0] == ArrayType([0, 1, 2, 3]) + value = 0 + for i in range(2): + for j in range(3): + for k in range(4): + assert array[i, j, k] == value + value += 1 + + raises(ValueError, lambda: array[3, 4, 5]) + raises(ValueError, lambda: array[3, 4, 5, 6]) + raises(ValueError, lambda: array[3, 4, 5, 3:4]) + + +def test_sparse(): + sparse_array = MutableSparseNDimArray([0, 0, 0, 1], (2, 2)) + assert len(sparse_array) == 2 * 2 + # dictionary where all data is, only non-zero entries are actually stored: + assert len(sparse_array._sparse_array) == 1 + + assert sparse_array.tolist() == [[0, 0], [0, 1]] + + for i, j in zip(sparse_array, [[0, 0], [0, 1]]): + assert i == MutableSparseNDimArray(j) + + sparse_array[0, 0] = 123 + assert len(sparse_array._sparse_array) == 2 + assert sparse_array[0, 0] == 123 + assert sparse_array/0 == MutableSparseNDimArray([[S.ComplexInfinity, S.NaN], [S.NaN, S.ComplexInfinity]], (2, 2)) + + # when element in sparse array become zero it will disappear from + # dictionary + sparse_array[0, 0] = 0 + assert len(sparse_array._sparse_array) == 1 + sparse_array[1, 1] = 0 + assert len(sparse_array._sparse_array) == 0 + assert sparse_array[0, 0] == 0 + + # test for large scale sparse array + # equality test + a = MutableSparseNDimArray.zeros(100000, 200000) + b = MutableSparseNDimArray.zeros(100000, 200000) + assert a == b + a[1, 1] = 1 + b[1, 1] = 2 + assert a != b + + # __mul__ and __rmul__ + assert a * 3 == MutableSparseNDimArray({200001: 3}, (100000, 200000)) + assert 3 * a == MutableSparseNDimArray({200001: 3}, (100000, 200000)) + assert a * 0 == MutableSparseNDimArray({}, (100000, 200000)) + assert 0 * a == MutableSparseNDimArray({}, (100000, 200000)) + + # __truediv__ + assert a/3 == MutableSparseNDimArray({200001: Rational(1, 3)}, (100000, 200000)) + + # __neg__ + assert -a == MutableSparseNDimArray({200001: -1}, (100000, 200000)) + + +def test_calculation(): + + a = MutableDenseNDimArray([1]*9, (3, 3)) + b = MutableDenseNDimArray([9]*9, (3, 3)) + + c = a + b + for i in c: + assert i == MutableDenseNDimArray([10, 10, 10]) + + assert c == MutableDenseNDimArray([10]*9, (3, 3)) + assert c == MutableSparseNDimArray([10]*9, (3, 3)) + + c = b - a + for i in c: + assert i == MutableSparseNDimArray([8, 8, 8]) + + assert c == MutableDenseNDimArray([8]*9, (3, 3)) + assert c == MutableSparseNDimArray([8]*9, (3, 3)) + + +def test_ndim_array_converting(): + dense_array = MutableDenseNDimArray([1, 2, 3, 4], (2, 2)) + alist = dense_array.tolist() + + assert alist == [[1, 2], [3, 4]] + + matrix = dense_array.tomatrix() + assert (isinstance(matrix, Matrix)) + + for i in range(len(dense_array)): + assert dense_array[dense_array._get_tuple_index(i)] == matrix[i] + assert matrix.shape == dense_array.shape + + assert MutableDenseNDimArray(matrix) == dense_array + assert MutableDenseNDimArray(matrix.as_immutable()) == dense_array + assert MutableDenseNDimArray(matrix.as_mutable()) == dense_array + + sparse_array = MutableSparseNDimArray([1, 2, 3, 4], (2, 2)) + alist = sparse_array.tolist() + + assert alist == [[1, 2], [3, 4]] + + matrix = sparse_array.tomatrix() + assert(isinstance(matrix, SparseMatrix)) + + for i in range(len(sparse_array)): + assert sparse_array[sparse_array._get_tuple_index(i)] == matrix[i] + assert matrix.shape == sparse_array.shape + + assert MutableSparseNDimArray(matrix) == sparse_array + assert MutableSparseNDimArray(matrix.as_immutable()) == sparse_array + assert MutableSparseNDimArray(matrix.as_mutable()) == sparse_array + + +def test_converting_functions(): + arr_list = [1, 2, 3, 4] + arr_matrix = Matrix(((1, 2), (3, 4))) + + # list + arr_ndim_array = MutableDenseNDimArray(arr_list, (2, 2)) + assert (isinstance(arr_ndim_array, MutableDenseNDimArray)) + assert arr_matrix.tolist() == arr_ndim_array.tolist() + + # Matrix + arr_ndim_array = MutableDenseNDimArray(arr_matrix) + assert (isinstance(arr_ndim_array, MutableDenseNDimArray)) + assert arr_matrix.tolist() == arr_ndim_array.tolist() + assert arr_matrix.shape == arr_ndim_array.shape + + +def test_equality(): + first_list = [1, 2, 3, 4] + second_list = [1, 2, 3, 4] + third_list = [4, 3, 2, 1] + assert first_list == second_list + assert first_list != third_list + + first_ndim_array = MutableDenseNDimArray(first_list, (2, 2)) + second_ndim_array = MutableDenseNDimArray(second_list, (2, 2)) + third_ndim_array = MutableDenseNDimArray(third_list, (2, 2)) + fourth_ndim_array = MutableDenseNDimArray(first_list, (2, 2)) + + assert first_ndim_array == second_ndim_array + second_ndim_array[0, 0] = 0 + assert first_ndim_array != second_ndim_array + assert first_ndim_array != third_ndim_array + assert first_ndim_array == fourth_ndim_array + + +def test_arithmetic(): + a = MutableDenseNDimArray([3 for i in range(9)], (3, 3)) + b = MutableDenseNDimArray([7 for i in range(9)], (3, 3)) + + c1 = a + b + c2 = b + a + assert c1 == c2 + + d1 = a - b + d2 = b - a + assert d1 == d2 * (-1) + + e1 = a * 5 + e2 = 5 * a + e3 = copy(a) + e3 *= 5 + assert e1 == e2 == e3 + + f1 = a / 5 + f2 = copy(a) + f2 /= 5 + assert f1 == f2 + assert f1[0, 0] == f1[0, 1] == f1[0, 2] == f1[1, 0] == f1[1, 1] == \ + f1[1, 2] == f1[2, 0] == f1[2, 1] == f1[2, 2] == Rational(3, 5) + + assert type(a) == type(b) == type(c1) == type(c2) == type(d1) == type(d2) \ + == type(e1) == type(e2) == type(e3) == type(f1) + + z0 = -a + assert z0 == MutableDenseNDimArray([-3 for i in range(9)], (3, 3)) + + +def test_higher_dimenions(): + m3 = MutableDenseNDimArray(range(10, 34), (2, 3, 4)) + + assert m3.tolist() == [[[10, 11, 12, 13], + [14, 15, 16, 17], + [18, 19, 20, 21]], + + [[22, 23, 24, 25], + [26, 27, 28, 29], + [30, 31, 32, 33]]] + + assert m3._get_tuple_index(0) == (0, 0, 0) + assert m3._get_tuple_index(1) == (0, 0, 1) + assert m3._get_tuple_index(4) == (0, 1, 0) + assert m3._get_tuple_index(12) == (1, 0, 0) + + assert str(m3) == '[[[10, 11, 12, 13], [14, 15, 16, 17], [18, 19, 20, 21]], [[22, 23, 24, 25], [26, 27, 28, 29], [30, 31, 32, 33]]]' + + m3_rebuilt = MutableDenseNDimArray([[[10, 11, 12, 13], [14, 15, 16, 17], [18, 19, 20, 21]], [[22, 23, 24, 25], [26, 27, 28, 29], [30, 31, 32, 33]]]) + assert m3 == m3_rebuilt + + m3_other = MutableDenseNDimArray([[[10, 11, 12, 13], [14, 15, 16, 17], [18, 19, 20, 21]], [[22, 23, 24, 25], [26, 27, 28, 29], [30, 31, 32, 33]]], (2, 3, 4)) + + assert m3 == m3_other + + +def test_slices(): + md = MutableDenseNDimArray(range(10, 34), (2, 3, 4)) + + assert md[:] == MutableDenseNDimArray(range(10, 34), (2, 3, 4)) + assert md[:, :, 0].tomatrix() == Matrix([[10, 14, 18], [22, 26, 30]]) + assert md[0, 1:2, :].tomatrix() == Matrix([[14, 15, 16, 17]]) + assert md[0, 1:3, :].tomatrix() == Matrix([[14, 15, 16, 17], [18, 19, 20, 21]]) + assert md[:, :, :] == md + + sd = MutableSparseNDimArray(range(10, 34), (2, 3, 4)) + assert sd == MutableSparseNDimArray(md) + + assert sd[:] == MutableSparseNDimArray(range(10, 34), (2, 3, 4)) + assert sd[:, :, 0].tomatrix() == Matrix([[10, 14, 18], [22, 26, 30]]) + assert sd[0, 1:2, :].tomatrix() == Matrix([[14, 15, 16, 17]]) + assert sd[0, 1:3, :].tomatrix() == Matrix([[14, 15, 16, 17], [18, 19, 20, 21]]) + assert sd[:, :, :] == sd + + +def test_slices_assign(): + a = MutableDenseNDimArray(range(12), shape=(4, 3)) + b = MutableSparseNDimArray(range(12), shape=(4, 3)) + + for i in [a, b]: + assert i.tolist() == [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11]] + i[0, :] = [2, 2, 2] + assert i.tolist() == [[2, 2, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11]] + i[0, 1:] = [8, 8] + assert i.tolist() == [[2, 8, 8], [3, 4, 5], [6, 7, 8], [9, 10, 11]] + i[1:3, 1] = [20, 44] + assert i.tolist() == [[2, 8, 8], [3, 20, 5], [6, 44, 8], [9, 10, 11]] + + +def test_diff(): + from sympy.abc import x, y, z + md = MutableDenseNDimArray([[x, y], [x*z, x*y*z]]) + assert md.diff(x) == MutableDenseNDimArray([[1, 0], [z, y*z]]) + assert diff(md, x) == MutableDenseNDimArray([[1, 0], [z, y*z]]) + + sd = MutableSparseNDimArray(md) + assert sd == MutableSparseNDimArray([x, y, x*z, x*y*z], (2, 2)) + assert sd.diff(x) == MutableSparseNDimArray([[1, 0], [z, y*z]]) + assert diff(sd, x) == MutableSparseNDimArray([[1, 0], [z, y*z]]) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_ndim_array.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_ndim_array.py new file mode 100644 index 0000000000000000000000000000000000000000..7ff9b032631c01272c00478e4cdf0dcbc6997990 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_ndim_array.py @@ -0,0 +1,73 @@ +from sympy.testing.pytest import raises +from sympy.functions.elementary.trigonometric import sin, cos +from sympy.matrices.dense import Matrix +from sympy.simplify import simplify +from sympy.tensor.array import Array +from sympy.tensor.array.dense_ndim_array import ( + ImmutableDenseNDimArray, MutableDenseNDimArray) +from sympy.tensor.array.sparse_ndim_array import ( + ImmutableSparseNDimArray, MutableSparseNDimArray) + +from sympy.abc import x, y + +mutable_array_types = [ + MutableDenseNDimArray, + MutableSparseNDimArray +] + +array_types = [ + ImmutableDenseNDimArray, + ImmutableSparseNDimArray, + MutableDenseNDimArray, + MutableSparseNDimArray +] + + +def test_array_negative_indices(): + for ArrayType in array_types: + test_array = ArrayType([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]]) + assert test_array[:, -1] == Array([5, 10]) + assert test_array[:, -2] == Array([4, 9]) + assert test_array[:, -3] == Array([3, 8]) + assert test_array[:, -4] == Array([2, 7]) + assert test_array[:, -5] == Array([1, 6]) + assert test_array[:, 0] == Array([1, 6]) + assert test_array[:, 1] == Array([2, 7]) + assert test_array[:, 2] == Array([3, 8]) + assert test_array[:, 3] == Array([4, 9]) + assert test_array[:, 4] == Array([5, 10]) + + raises(ValueError, lambda: test_array[:, -6]) + raises(ValueError, lambda: test_array[-3, :]) + + assert test_array[-1, -1] == 10 + + +def test_issue_18361(): + A = Array([sin(2 * x) - 2 * sin(x) * cos(x)]) + B = Array([sin(x)**2 + cos(x)**2, 0]) + C = Array([(x + x**2)/(x*sin(y)**2 + x*cos(y)**2), 2*sin(x)*cos(x)]) + assert simplify(A) == Array([0]) + assert simplify(B) == Array([1, 0]) + assert simplify(C) == Array([x + 1, sin(2*x)]) + + +def test_issue_20222(): + A = Array([[1, 2], [3, 4]]) + B = Matrix([[1,2],[3,4]]) + raises(TypeError, lambda: A - B) + + +def test_issue_17851(): + for array_type in array_types: + A = array_type([]) + assert isinstance(A, array_type) + assert A.shape == (0,) + assert list(A) == [] + + +def test_issue_and_18715(): + for array_type in mutable_array_types: + A = array_type([0, 1, 2]) + A[0] += 5 + assert A[0] == 5 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_ndim_array_conversions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_ndim_array_conversions.py new file mode 100644 index 0000000000000000000000000000000000000000..f43260ccc636ac461ba0c06dbfcf3fe3a8d5338d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/array/tests/test_ndim_array_conversions.py @@ -0,0 +1,22 @@ +from sympy.tensor.array import (ImmutableDenseNDimArray, + ImmutableSparseNDimArray, MutableDenseNDimArray, MutableSparseNDimArray) +from sympy.abc import x, y, z + + +def test_NDim_array_conv(): + MD = MutableDenseNDimArray([x, y, z]) + MS = MutableSparseNDimArray([x, y, z]) + ID = ImmutableDenseNDimArray([x, y, z]) + IS = ImmutableSparseNDimArray([x, y, z]) + + assert MD.as_immutable() == ID + assert MD.as_mutable() == MD + + assert MS.as_immutable() == IS + assert MS.as_mutable() == MS + + assert ID.as_immutable() == ID + assert ID.as_mutable() == MD + + assert IS.as_immutable() == IS + assert IS.as_mutable() == MS diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/functions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/functions.py new file mode 100644 index 0000000000000000000000000000000000000000..f14599d69152db1713f21c9dd785683901c5eeb9 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/functions.py @@ -0,0 +1,154 @@ +from collections.abc import Iterable +from functools import singledispatch + +from sympy.core.expr import Expr +from sympy.core.mul import Mul +from sympy.core.singleton import S +from sympy.core.sympify import sympify +from sympy.core.parameters import global_parameters + + +class TensorProduct(Expr): + """ + Generic class for tensor products. + """ + is_number = False + + def __new__(cls, *args, **kwargs): + from sympy.tensor.array import NDimArray, tensorproduct, Array + from sympy.matrices.expressions.matexpr import MatrixExpr + from sympy.matrices.matrixbase import MatrixBase + from sympy.strategies import flatten + + args = [sympify(arg) for arg in args] + evaluate = kwargs.get("evaluate", global_parameters.evaluate) + + if not evaluate: + obj = Expr.__new__(cls, *args) + return obj + + arrays = [] + other = [] + scalar = S.One + for arg in args: + if isinstance(arg, (Iterable, MatrixBase, NDimArray)): + arrays.append(Array(arg)) + elif isinstance(arg, (MatrixExpr,)): + other.append(arg) + else: + scalar *= arg + + coeff = scalar*tensorproduct(*arrays) + if len(other) == 0: + return coeff + if coeff != 1: + newargs = [coeff] + other + else: + newargs = other + obj = Expr.__new__(cls, *newargs, **kwargs) + return flatten(obj) + + def rank(self): + return len(self.shape) + + def _get_args_shapes(self): + from sympy.tensor.array import Array + return [i.shape if hasattr(i, "shape") else Array(i).shape for i in self.args] + + @property + def shape(self): + shape_list = self._get_args_shapes() + return sum(shape_list, ()) + + def __getitem__(self, index): + index = iter(index) + return Mul.fromiter( + arg.__getitem__(tuple(next(index) for i in shp)) + for arg, shp in zip(self.args, self._get_args_shapes()) + ) + + +@singledispatch +def shape(expr): + """ + Return the shape of the *expr* as a tuple. *expr* should represent + suitable object such as matrix or array. + + Parameters + ========== + + expr : SymPy object having ``MatrixKind`` or ``ArrayKind``. + + Raises + ====== + + NoShapeError : Raised when object with wrong kind is passed. + + Examples + ======== + + This function returns the shape of any object representing matrix or array. + + >>> from sympy import shape, Array, ImmutableDenseMatrix, Integral + >>> from sympy.abc import x + >>> A = Array([1, 2]) + >>> shape(A) + (2,) + >>> shape(Integral(A, x)) + (2,) + >>> M = ImmutableDenseMatrix([1, 2]) + >>> shape(M) + (2, 1) + >>> shape(Integral(M, x)) + (2, 1) + + You can support new type by dispatching. + + >>> from sympy import Expr + >>> class NewExpr(Expr): + ... pass + >>> @shape.register(NewExpr) + ... def _(expr): + ... return shape(expr.args[0]) + >>> shape(NewExpr(M)) + (2, 1) + + If unsuitable expression is passed, ``NoShapeError()`` will be raised. + + >>> shape(Integral(x, x)) + Traceback (most recent call last): + ... + sympy.tensor.functions.NoShapeError: shape() called on non-array object: Integral(x, x) + + Notes + ===== + + Array-like classes (such as ``Matrix`` or ``NDimArray``) has ``shape`` + property which returns its shape, but it cannot be used for non-array + classes containing array. This function returns the shape of any + registered object representing array. + + """ + if hasattr(expr, "shape"): + return expr.shape + raise NoShapeError( + "%s does not have shape, or its type is not registered to shape()." % expr) + + +class NoShapeError(Exception): + """ + Raised when ``shape()`` is called on non-array object. + + This error can be imported from ``sympy.tensor.functions``. + + Examples + ======== + + >>> from sympy import shape + >>> from sympy.abc import x + >>> shape(x) + Traceback (most recent call last): + ... + sympy.tensor.functions.NoShapeError: shape() called on non-array object: x + """ + pass diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/index_methods.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/index_methods.py new file mode 100644 index 0000000000000000000000000000000000000000..12f707b60b4ad0bcadc35a222d9abe0cc5e033fc --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/index_methods.py @@ -0,0 +1,469 @@ +"""Module with functions operating on IndexedBase, Indexed and Idx objects + + - Check shape conformance + - Determine indices in resulting expression + + etc. + + Methods in this module could be implemented by calling methods on Expr + objects instead. When things stabilize this could be a useful + refactoring. +""" + +from functools import reduce + +from sympy.core.function import Function +from sympy.functions import exp, Piecewise +from sympy.tensor.indexed import Idx, Indexed +from sympy.utilities import sift + +from collections import OrderedDict + +class IndexConformanceException(Exception): + pass + +def _unique_and_repeated(inds): + """ + Returns the unique and repeated indices. Also note, from the examples given below + that the order of indices is maintained as given in the input. + + Examples + ======== + + >>> from sympy.tensor.index_methods import _unique_and_repeated + >>> _unique_and_repeated([2, 3, 1, 3, 0, 4, 0]) + ([2, 1, 4], [3, 0]) + """ + uniq = OrderedDict() + for i in inds: + if i in uniq: + uniq[i] = 0 + else: + uniq[i] = 1 + return sift(uniq, lambda x: uniq[x], binary=True) + +def _remove_repeated(inds): + """ + Removes repeated objects from sequences + + Returns a set of the unique objects and a tuple of all that have been + removed. + + Examples + ======== + + >>> from sympy.tensor.index_methods import _remove_repeated + >>> l1 = [1, 2, 3, 2] + >>> _remove_repeated(l1) + ({1, 3}, (2,)) + + """ + u, r = _unique_and_repeated(inds) + return set(u), tuple(r) + + +def _get_indices_Mul(expr, return_dummies=False): + """Determine the outer indices of a Mul object. + + Examples + ======== + + >>> from sympy.tensor.index_methods import _get_indices_Mul + >>> from sympy.tensor.indexed import IndexedBase, Idx + >>> i, j, k = map(Idx, ['i', 'j', 'k']) + >>> x = IndexedBase('x') + >>> y = IndexedBase('y') + >>> _get_indices_Mul(x[i, k]*y[j, k]) + ({i, j}, {}) + >>> _get_indices_Mul(x[i, k]*y[j, k], return_dummies=True) + ({i, j}, {}, (k,)) + + """ + + inds = list(map(get_indices, expr.args)) + inds, syms = list(zip(*inds)) + + inds = list(map(list, inds)) + inds = list(reduce(lambda x, y: x + y, inds)) + inds, dummies = _remove_repeated(inds) + + symmetry = {} + for s in syms: + for pair in s: + if pair in symmetry: + symmetry[pair] *= s[pair] + else: + symmetry[pair] = s[pair] + + if return_dummies: + return inds, symmetry, dummies + else: + return inds, symmetry + + +def _get_indices_Pow(expr): + """Determine outer indices of a power or an exponential. + + A power is considered a universal function, so that the indices of a Pow is + just the collection of indices present in the expression. This may be + viewed as a bit inconsistent in the special case: + + x[i]**2 = x[i]*x[i] (1) + + The above expression could have been interpreted as the contraction of x[i] + with itself, but we choose instead to interpret it as a function + + lambda y: y**2 + + applied to each element of x (a universal function in numpy terms). In + order to allow an interpretation of (1) as a contraction, we need + contravariant and covariant Idx subclasses. (FIXME: this is not yet + implemented) + + Expressions in the base or exponent are subject to contraction as usual, + but an index that is present in the exponent, will not be considered + contractable with its own base. Note however, that indices in the same + exponent can be contracted with each other. + + Examples + ======== + + >>> from sympy.tensor.index_methods import _get_indices_Pow + >>> from sympy import Pow, exp, IndexedBase, Idx + >>> A = IndexedBase('A') + >>> x = IndexedBase('x') + >>> i, j, k = map(Idx, ['i', 'j', 'k']) + >>> _get_indices_Pow(exp(A[i, j]*x[j])) + ({i}, {}) + >>> _get_indices_Pow(Pow(x[i], x[i])) + ({i}, {}) + >>> _get_indices_Pow(Pow(A[i, j]*x[j], x[i])) + ({i}, {}) + + """ + base, exp = expr.as_base_exp() + binds, bsyms = get_indices(base) + einds, esyms = get_indices(exp) + + inds = binds | einds + + # FIXME: symmetries from power needs to check special cases, else nothing + symmetries = {} + + return inds, symmetries + + +def _get_indices_Add(expr): + """Determine outer indices of an Add object. + + In a sum, each term must have the same set of outer indices. A valid + expression could be + + x(i)*y(j) - x(j)*y(i) + + But we do not allow expressions like: + + x(i)*y(j) - z(j)*z(j) + + FIXME: Add support for Numpy broadcasting + + Examples + ======== + + >>> from sympy.tensor.index_methods import _get_indices_Add + >>> from sympy.tensor.indexed import IndexedBase, Idx + >>> i, j, k = map(Idx, ['i', 'j', 'k']) + >>> x = IndexedBase('x') + >>> y = IndexedBase('y') + >>> _get_indices_Add(x[i] + x[k]*y[i, k]) + ({i}, {}) + + """ + + inds = list(map(get_indices, expr.args)) + inds, syms = list(zip(*inds)) + + # allow broadcast of scalars + non_scalars = [x for x in inds if x != set()] + if not non_scalars: + return set(), {} + + if not all(x == non_scalars[0] for x in non_scalars[1:]): + raise IndexConformanceException("Indices are not consistent: %s" % expr) + if not reduce(lambda x, y: x != y or y, syms): + symmetries = syms[0] + else: + # FIXME: search for symmetries + symmetries = {} + + return non_scalars[0], symmetries + + +def get_indices(expr): + """Determine the outer indices of expression ``expr`` + + By *outer* we mean indices that are not summation indices. Returns a set + and a dict. The set contains outer indices and the dict contains + information about index symmetries. + + Examples + ======== + + >>> from sympy.tensor.index_methods import get_indices + >>> from sympy import symbols + >>> from sympy.tensor import IndexedBase + >>> x, y, A = map(IndexedBase, ['x', 'y', 'A']) + >>> i, j, a, z = symbols('i j a z', integer=True) + + The indices of the total expression is determined, Repeated indices imply a + summation, for instance the trace of a matrix A: + + >>> get_indices(A[i, i]) + (set(), {}) + + In the case of many terms, the terms are required to have identical + outer indices. Else an IndexConformanceException is raised. + + >>> get_indices(x[i] + A[i, j]*y[j]) + ({i}, {}) + + :Exceptions: + + An IndexConformanceException means that the terms ar not compatible, e.g. + + >>> get_indices(x[i] + y[j]) #doctest: +SKIP + (...) + IndexConformanceException: Indices are not consistent: x(i) + y(j) + + .. warning:: + The concept of *outer* indices applies recursively, starting on the deepest + level. This implies that dummies inside parenthesis are assumed to be + summed first, so that the following expression is handled gracefully: + + >>> get_indices((x[i] + A[i, j]*y[j])*x[j]) + ({i, j}, {}) + + This is correct and may appear convenient, but you need to be careful + with this as SymPy will happily .expand() the product, if requested. The + resulting expression would mix the outer ``j`` with the dummies inside + the parenthesis, which makes it a different expression. To be on the + safe side, it is best to avoid such ambiguities by using unique indices + for all contractions that should be held separate. + + """ + # We call ourself recursively to determine indices of sub expressions. + + # break recursion + if isinstance(expr, Indexed): + c = expr.indices + inds, dummies = _remove_repeated(c) + return inds, {} + elif expr is None: + return set(), {} + elif isinstance(expr, Idx): + return {expr}, {} + elif expr.is_Atom: + return set(), {} + + + # recurse via specialized functions + else: + if expr.is_Mul: + return _get_indices_Mul(expr) + elif expr.is_Add: + return _get_indices_Add(expr) + elif expr.is_Pow or isinstance(expr, exp): + return _get_indices_Pow(expr) + + elif isinstance(expr, Piecewise): + # FIXME: No support for Piecewise yet + return set(), {} + elif isinstance(expr, Function): + # Support ufunc like behaviour by returning indices from arguments. + # Functions do not interpret repeated indices across arguments + # as summation + ind0 = set() + for arg in expr.args: + ind, sym = get_indices(arg) + ind0 |= ind + return ind0, sym + + # this test is expensive, so it should be at the end + elif not expr.has(Indexed): + return set(), {} + raise NotImplementedError( + "FIXME: No specialized handling of type %s" % type(expr)) + + +def get_contraction_structure(expr): + """Determine dummy indices of ``expr`` and describe its structure + + By *dummy* we mean indices that are summation indices. + + The structure of the expression is determined and described as follows: + + 1) A conforming summation of Indexed objects is described with a dict where + the keys are summation indices and the corresponding values are sets + containing all terms for which the summation applies. All Add objects + in the SymPy expression tree are described like this. + + 2) For all nodes in the SymPy expression tree that are *not* of type Add, the + following applies: + + If a node discovers contractions in one of its arguments, the node + itself will be stored as a key in the dict. For that key, the + corresponding value is a list of dicts, each of which is the result of a + recursive call to get_contraction_structure(). The list contains only + dicts for the non-trivial deeper contractions, omitting dicts with None + as the one and only key. + + .. Note:: The presence of expressions among the dictionary keys indicates + multiple levels of index contractions. A nested dict displays nested + contractions and may itself contain dicts from a deeper level. In + practical calculations the summation in the deepest nested level must be + calculated first so that the outer expression can access the resulting + indexed object. + + Examples + ======== + + >>> from sympy.tensor.index_methods import get_contraction_structure + >>> from sympy import default_sort_key + >>> from sympy.tensor import IndexedBase, Idx + >>> x, y, A = map(IndexedBase, ['x', 'y', 'A']) + >>> i, j, k, l = map(Idx, ['i', 'j', 'k', 'l']) + >>> get_contraction_structure(x[i]*y[i] + A[j, j]) + {(i,): {x[i]*y[i]}, (j,): {A[j, j]}} + >>> get_contraction_structure(x[i]*y[j]) + {None: {x[i]*y[j]}} + + A multiplication of contracted factors results in nested dicts representing + the internal contractions. + + >>> d = get_contraction_structure(x[i, i]*y[j, j]) + >>> sorted(d.keys(), key=default_sort_key) + [None, x[i, i]*y[j, j]] + + In this case, the product has no contractions: + + >>> d[None] + {x[i, i]*y[j, j]} + + Factors are contracted "first": + + >>> sorted(d[x[i, i]*y[j, j]], key=default_sort_key) + [{(i,): {x[i, i]}}, {(j,): {y[j, j]}}] + + A parenthesized Add object is also returned as a nested dictionary. The + term containing the parenthesis is a Mul with a contraction among the + arguments, so it will be found as a key in the result. It stores the + dictionary resulting from a recursive call on the Add expression. + + >>> d = get_contraction_structure(x[i]*(y[i] + A[i, j]*x[j])) + >>> sorted(d.keys(), key=default_sort_key) + [(A[i, j]*x[j] + y[i])*x[i], (i,)] + >>> d[(i,)] + {(A[i, j]*x[j] + y[i])*x[i]} + >>> d[x[i]*(A[i, j]*x[j] + y[i])] + [{None: {y[i]}, (j,): {A[i, j]*x[j]}}] + + Powers with contractions in either base or exponent will also be found as + keys in the dictionary, mapping to a list of results from recursive calls: + + >>> d = get_contraction_structure(A[j, j]**A[i, i]) + >>> d[None] + {A[j, j]**A[i, i]} + >>> nested_contractions = d[A[j, j]**A[i, i]] + >>> nested_contractions[0] + {(j,): {A[j, j]}} + >>> nested_contractions[1] + {(i,): {A[i, i]}} + + The description of the contraction structure may appear complicated when + represented with a string in the above examples, but it is easy to iterate + over: + + >>> from sympy import Expr + >>> for key in d: + ... if isinstance(key, Expr): + ... continue + ... for term in d[key]: + ... if term in d: + ... # treat deepest contraction first + ... pass + ... # treat outermost contactions here + + """ + + # We call ourself recursively to inspect sub expressions. + + if isinstance(expr, Indexed): + junk, key = _remove_repeated(expr.indices) + return {key or None: {expr}} + elif expr.is_Atom: + return {None: {expr}} + elif expr.is_Mul: + junk, junk, key = _get_indices_Mul(expr, return_dummies=True) + result = {key or None: {expr}} + # recurse on every factor + nested = [] + for fac in expr.args: + facd = get_contraction_structure(fac) + if not (None in facd and len(facd) == 1): + nested.append(facd) + if nested: + result[expr] = nested + return result + elif expr.is_Pow or isinstance(expr, exp): + # recurse in base and exp separately. If either has internal + # contractions we must include ourselves as a key in the returned dict + b, e = expr.as_base_exp() + dbase = get_contraction_structure(b) + dexp = get_contraction_structure(e) + + dicts = [] + for d in dbase, dexp: + if not (None in d and len(d) == 1): + dicts.append(d) + result = {None: {expr}} + if dicts: + result[expr] = dicts + return result + elif expr.is_Add: + # Note: we just collect all terms with identical summation indices, We + # do nothing to identify equivalent terms here, as this would require + # substitutions or pattern matching in expressions of unknown + # complexity. + result = {} + for term in expr.args: + # recurse on every term + d = get_contraction_structure(term) + for key in d: + if key in result: + result[key] |= d[key] + else: + result[key] = d[key] + return result + + elif isinstance(expr, Piecewise): + # FIXME: No support for Piecewise yet + return {None: expr} + elif isinstance(expr, Function): + # Collect non-trivial contraction structures in each argument + # We do not report repeated indices in separate arguments as a + # contraction + deeplist = [] + for arg in expr.args: + deep = get_contraction_structure(arg) + if not (None in deep and len(deep) == 1): + deeplist.append(deep) + d = {None: {expr}} + if deeplist: + d[expr] = deeplist + return d + + # this test is expensive, so it should be at the end + elif not expr.has(Indexed): + return {None: {expr}} + raise NotImplementedError( + "FIXME: No specialized handling of type %s" % type(expr)) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/indexed.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/indexed.py new file mode 100644 index 0000000000000000000000000000000000000000..feddad21e52bbab2e1243beafdb11f30b2eded4d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/indexed.py @@ -0,0 +1,793 @@ +r"""Module that defines indexed objects. + +The classes ``IndexedBase``, ``Indexed``, and ``Idx`` represent a +matrix element ``M[i, j]`` as in the following diagram:: + + 1) The Indexed class represents the entire indexed object. + | + ___|___ + ' ' + M[i, j] + / \__\______ + | | + | | + | 2) The Idx class represents indices; each Idx can + | optionally contain information about its range. + | + 3) IndexedBase represents the 'stem' of an indexed object, here `M`. + The stem used by itself is usually taken to represent the entire + array. + +There can be any number of indices on an Indexed object. No +transformation properties are implemented in these Base objects, but +implicit contraction of repeated indices is supported. + +Note that the support for complicated (i.e. non-atomic) integer +expressions as indices is limited. (This should be improved in +future releases.) + +Examples +======== + +To express the above matrix element example you would write: + +>>> from sympy import symbols, IndexedBase, Idx +>>> M = IndexedBase('M') +>>> i, j = symbols('i j', cls=Idx) +>>> M[i, j] +M[i, j] + +Repeated indices in a product implies a summation, so to express a +matrix-vector product in terms of Indexed objects: + +>>> x = IndexedBase('x') +>>> M[i, j]*x[j] +M[i, j]*x[j] + +If the indexed objects will be converted to component based arrays, e.g. +with the code printers or the autowrap framework, you also need to provide +(symbolic or numerical) dimensions. This can be done by passing an +optional shape parameter to IndexedBase upon construction: + +>>> dim1, dim2 = symbols('dim1 dim2', integer=True) +>>> A = IndexedBase('A', shape=(dim1, 2*dim1, dim2)) +>>> A.shape +(dim1, 2*dim1, dim2) +>>> A[i, j, 3].shape +(dim1, 2*dim1, dim2) + +If an IndexedBase object has no shape information, it is assumed that the +array is as large as the ranges of its indices: + +>>> n, m = symbols('n m', integer=True) +>>> i = Idx('i', m) +>>> j = Idx('j', n) +>>> M[i, j].shape +(m, n) +>>> M[i, j].ranges +[(0, m - 1), (0, n - 1)] + +The above can be compared with the following: + +>>> A[i, 2, j].shape +(dim1, 2*dim1, dim2) +>>> A[i, 2, j].ranges +[(0, m - 1), None, (0, n - 1)] + +To analyze the structure of indexed expressions, you can use the methods +get_indices() and get_contraction_structure(): + +>>> from sympy.tensor import get_indices, get_contraction_structure +>>> get_indices(A[i, j, j]) +({i}, {}) +>>> get_contraction_structure(A[i, j, j]) +{(j,): {A[i, j, j]}} + +See the appropriate docstrings for a detailed explanation of the output. +""" + +# TODO: (some ideas for improvement) +# +# o test and guarantee numpy compatibility +# - implement full support for broadcasting +# - strided arrays +# +# o more functions to analyze indexed expressions +# - identify standard constructs, e.g matrix-vector product in a subexpression +# +# o functions to generate component based arrays (numpy and sympy.Matrix) +# - generate a single array directly from Indexed +# - convert simple sub-expressions +# +# o sophisticated indexing (possibly in subclasses to preserve simplicity) +# - Idx with range smaller than dimension of Indexed +# - Idx with stepsize != 1 +# - Idx with step determined by function call +from collections.abc import Iterable + +from sympy.core.numbers import Number +from sympy.core.assumptions import StdFactKB +from sympy.core import Expr, Tuple, sympify, S +from sympy.core.symbol import _filter_assumptions, Symbol +from sympy.core.logic import fuzzy_bool, fuzzy_not +from sympy.core.sympify import _sympify +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.multipledispatch import dispatch +from sympy.utilities.iterables import is_sequence, NotIterable +from sympy.utilities.misc import filldedent + + +class IndexException(Exception): + pass + + +class Indexed(Expr): + """Represents a mathematical object with indices. + + >>> from sympy import Indexed, IndexedBase, Idx, symbols + >>> i, j = symbols('i j', cls=Idx) + >>> Indexed('A', i, j) + A[i, j] + + It is recommended that ``Indexed`` objects be created by indexing ``IndexedBase``: + ``IndexedBase('A')[i, j]`` instead of ``Indexed(IndexedBase('A'), i, j)``. + + >>> A = IndexedBase('A') + >>> a_ij = A[i, j] # Prefer this, + >>> b_ij = Indexed(A, i, j) # over this. + >>> a_ij == b_ij + True + + """ + is_Indexed = True + is_symbol = True + is_Atom = True + + def __new__(cls, base, *args, **kw_args): + from sympy.tensor.array.ndim_array import NDimArray + from sympy.matrices.matrixbase import MatrixBase + + if not args: + raise IndexException("Indexed needs at least one index.") + if isinstance(base, (str, Symbol)): + base = IndexedBase(base) + elif not hasattr(base, '__getitem__') and not isinstance(base, IndexedBase): + raise TypeError(filldedent(""" + The base can only be replaced with a string, Symbol, + IndexedBase or an object with a method for getting + items (i.e. an object with a `__getitem__` method). + """)) + args = list(map(sympify, args)) + if isinstance(base, (NDimArray, Iterable, Tuple, MatrixBase)) and all(i.is_number for i in args): + if len(args) == 1: + return base[args[0]] + else: + return base[args] + + base = _sympify(base) + + obj = Expr.__new__(cls, base, *args, **kw_args) + + IndexedBase._set_assumptions(obj, base.assumptions0) + + return obj + + def _hashable_content(self): + return super()._hashable_content() + tuple(sorted(self.assumptions0.items())) + + @property + def name(self): + return str(self) + + @property + def _diff_wrt(self): + """Allow derivatives with respect to an ``Indexed`` object.""" + return True + + def _eval_derivative(self, wrt): + from sympy.tensor.array.ndim_array import NDimArray + + if isinstance(wrt, Indexed) and wrt.base == self.base: + if len(self.indices) != len(wrt.indices): + msg = "Different # of indices: d({!s})/d({!s})".format(self, + wrt) + raise IndexException(msg) + result = S.One + for index1, index2 in zip(self.indices, wrt.indices): + result *= KroneckerDelta(index1, index2) + return result + elif isinstance(self.base, NDimArray): + from sympy.tensor.array import derive_by_array + return Indexed(derive_by_array(self.base, wrt), *self.args[1:]) + else: + if Tuple(self.indices).has(wrt): + return S.NaN + return S.Zero + + @property + def assumptions0(self): + return {k: v for k, v in self._assumptions.items() if v is not None} + + @property + def base(self): + """Returns the ``IndexedBase`` of the ``Indexed`` object. + + Examples + ======== + + >>> from sympy import Indexed, IndexedBase, Idx, symbols + >>> i, j = symbols('i j', cls=Idx) + >>> Indexed('A', i, j).base + A + >>> B = IndexedBase('B') + >>> B == B[i, j].base + True + + """ + return self.args[0] + + @property + def indices(self): + """ + Returns the indices of the ``Indexed`` object. + + Examples + ======== + + >>> from sympy import Indexed, Idx, symbols + >>> i, j = symbols('i j', cls=Idx) + >>> Indexed('A', i, j).indices + (i, j) + + """ + return self.args[1:] + + @property + def rank(self): + """ + Returns the rank of the ``Indexed`` object. + + Examples + ======== + + >>> from sympy import Indexed, Idx, symbols + >>> i, j, k, l, m = symbols('i:m', cls=Idx) + >>> Indexed('A', i, j).rank + 2 + >>> q = Indexed('A', i, j, k, l, m) + >>> q.rank + 5 + >>> q.rank == len(q.indices) + True + + """ + return len(self.args) - 1 + + @property + def shape(self): + """Returns a list with dimensions of each index. + + Dimensions is a property of the array, not of the indices. Still, if + the ``IndexedBase`` does not define a shape attribute, it is assumed + that the ranges of the indices correspond to the shape of the array. + + >>> from sympy import IndexedBase, Idx, symbols + >>> n, m = symbols('n m', integer=True) + >>> i = Idx('i', m) + >>> j = Idx('j', m) + >>> A = IndexedBase('A', shape=(n, n)) + >>> B = IndexedBase('B') + >>> A[i, j].shape + (n, n) + >>> B[i, j].shape + (m, m) + """ + + if self.base.shape: + return self.base.shape + sizes = [] + for i in self.indices: + upper = getattr(i, 'upper', None) + lower = getattr(i, 'lower', None) + if None in (upper, lower): + raise IndexException(filldedent(""" + Range is not defined for all indices in: %s""" % self)) + try: + size = upper - lower + 1 + except TypeError: + raise IndexException(filldedent(""" + Shape cannot be inferred from Idx with + undefined range: %s""" % self)) + sizes.append(size) + return Tuple(*sizes) + + @property + def ranges(self): + """Returns a list of tuples with lower and upper range of each index. + + If an index does not define the data members upper and lower, the + corresponding slot in the list contains ``None`` instead of a tuple. + + Examples + ======== + + >>> from sympy import Indexed,Idx, symbols + >>> Indexed('A', Idx('i', 2), Idx('j', 4), Idx('k', 8)).ranges + [(0, 1), (0, 3), (0, 7)] + >>> Indexed('A', Idx('i', 3), Idx('j', 3), Idx('k', 3)).ranges + [(0, 2), (0, 2), (0, 2)] + >>> x, y, z = symbols('x y z', integer=True) + >>> Indexed('A', x, y, z).ranges + [None, None, None] + + """ + ranges = [] + sentinel = object() + for i in self.indices: + upper = getattr(i, 'upper', sentinel) + lower = getattr(i, 'lower', sentinel) + if sentinel not in (upper, lower): + ranges.append((lower, upper)) + else: + ranges.append(None) + return ranges + + def _sympystr(self, p): + indices = list(map(p.doprint, self.indices)) + return "%s[%s]" % (p.doprint(self.base), ", ".join(indices)) + + @property + def free_symbols(self): + base_free_symbols = self.base.free_symbols + indices_free_symbols = { + fs for i in self.indices for fs in i.free_symbols} + if base_free_symbols: + return {self} | base_free_symbols | indices_free_symbols + else: + return indices_free_symbols + + @property + def expr_free_symbols(self): + from sympy.utilities.exceptions import sympy_deprecation_warning + sympy_deprecation_warning(""" + The expr_free_symbols property is deprecated. Use free_symbols to get + the free symbols of an expression. + """, + deprecated_since_version="1.9", + active_deprecations_target="deprecated-expr-free-symbols") + + return {self} + + +class IndexedBase(Expr, NotIterable): + """Represent the base or stem of an indexed object + + The IndexedBase class represent an array that contains elements. The main purpose + of this class is to allow the convenient creation of objects of the Indexed + class. The __getitem__ method of IndexedBase returns an instance of + Indexed. Alone, without indices, the IndexedBase class can be used as a + notation for e.g. matrix equations, resembling what you could do with the + Symbol class. But, the IndexedBase class adds functionality that is not + available for Symbol instances: + + - An IndexedBase object can optionally store shape information. This can + be used in to check array conformance and conditions for numpy + broadcasting. (TODO) + - An IndexedBase object implements syntactic sugar that allows easy symbolic + representation of array operations, using implicit summation of + repeated indices. + - The IndexedBase object symbolizes a mathematical structure equivalent + to arrays, and is recognized as such for code generation and automatic + compilation and wrapping. + + >>> from sympy.tensor import IndexedBase, Idx + >>> from sympy import symbols + >>> A = IndexedBase('A'); A + A + >>> type(A) + + + When an IndexedBase object receives indices, it returns an array with named + axes, represented by an Indexed object: + + >>> i, j = symbols('i j', integer=True) + >>> A[i, j, 2] + A[i, j, 2] + >>> type(A[i, j, 2]) + + + The IndexedBase constructor takes an optional shape argument. If given, + it overrides any shape information in the indices. (But not the index + ranges!) + + >>> m, n, o, p = symbols('m n o p', integer=True) + >>> i = Idx('i', m) + >>> j = Idx('j', n) + >>> A[i, j].shape + (m, n) + >>> B = IndexedBase('B', shape=(o, p)) + >>> B[i, j].shape + (o, p) + + Assumptions can be specified with keyword arguments the same way as for Symbol: + + >>> A_real = IndexedBase('A', real=True) + >>> A_real.is_real + True + >>> A != A_real + True + + Assumptions can also be inherited if a Symbol is used to initialize the IndexedBase: + + >>> I = symbols('I', integer=True) + >>> C_inherit = IndexedBase(I) + >>> C_explicit = IndexedBase('I', integer=True) + >>> C_inherit == C_explicit + True + """ + is_symbol = True + is_Atom = True + + @staticmethod + def _set_assumptions(obj, assumptions): + """Set assumptions on obj, making sure to apply consistent values.""" + tmp_asm_copy = assumptions.copy() + is_commutative = fuzzy_bool(assumptions.get('commutative', True)) + assumptions['commutative'] = is_commutative + obj._assumptions = StdFactKB(assumptions) + obj._assumptions._generator = tmp_asm_copy # Issue #8873 + + def __new__(cls, label, shape=None, *, offset=S.Zero, strides=None, **kw_args): + from sympy.matrices.matrixbase import MatrixBase + from sympy.tensor.array.ndim_array import NDimArray + + assumptions, kw_args = _filter_assumptions(kw_args) + if isinstance(label, str): + label = Symbol(label, **assumptions) + elif isinstance(label, Symbol): + assumptions = label._merge(assumptions) + elif isinstance(label, (MatrixBase, NDimArray)): + return label + elif isinstance(label, Iterable): + return _sympify(label) + else: + label = _sympify(label) + + if is_sequence(shape): + shape = Tuple(*shape) + elif shape is not None: + shape = Tuple(shape) + + if shape is not None: + obj = Expr.__new__(cls, label, shape) + else: + obj = Expr.__new__(cls, label) + obj._shape = shape + obj._offset = offset + obj._strides = strides + obj._name = str(label) + + IndexedBase._set_assumptions(obj, assumptions) + return obj + + @property + def name(self): + return self._name + + def _hashable_content(self): + return super()._hashable_content() + tuple(sorted(self.assumptions0.items())) + + @property + def assumptions0(self): + return {k: v for k, v in self._assumptions.items() if v is not None} + + def __getitem__(self, indices, **kw_args): + if is_sequence(indices): + # Special case needed because M[*my_tuple] is a syntax error. + if self.shape and len(self.shape) != len(indices): + raise IndexException("Rank mismatch.") + return Indexed(self, *indices, **kw_args) + else: + if self.shape and len(self.shape) != 1: + raise IndexException("Rank mismatch.") + return Indexed(self, indices, **kw_args) + + @property + def shape(self): + """Returns the shape of the ``IndexedBase`` object. + + Examples + ======== + + >>> from sympy import IndexedBase, Idx + >>> from sympy.abc import x, y + >>> IndexedBase('A', shape=(x, y)).shape + (x, y) + + Note: If the shape of the ``IndexedBase`` is specified, it will override + any shape information given by the indices. + + >>> A = IndexedBase('A', shape=(x, y)) + >>> B = IndexedBase('B') + >>> i = Idx('i', 2) + >>> j = Idx('j', 1) + >>> A[i, j].shape + (x, y) + >>> B[i, j].shape + (2, 1) + + """ + return self._shape + + @property + def strides(self): + """Returns the strided scheme for the ``IndexedBase`` object. + + Normally this is a tuple denoting the number of + steps to take in the respective dimension when traversing + an array. For code generation purposes strides='C' and + strides='F' can also be used. + + strides='C' would mean that code printer would unroll + in row-major order and 'F' means unroll in column major + order. + + """ + + return self._strides + + @property + def offset(self): + """Returns the offset for the ``IndexedBase`` object. + + This is the value added to the resulting index when the + 2D Indexed object is unrolled to a 1D form. Used in code + generation. + + Examples + ========== + >>> from sympy.printing import ccode + >>> from sympy.tensor import IndexedBase, Idx + >>> from sympy import symbols + >>> l, m, n, o = symbols('l m n o', integer=True) + >>> A = IndexedBase('A', strides=(l, m, n), offset=o) + >>> i, j, k = map(Idx, 'ijk') + >>> ccode(A[i, j, k]) + 'A[l*i + m*j + n*k + o]' + + """ + return self._offset + + @property + def label(self): + """Returns the label of the ``IndexedBase`` object. + + Examples + ======== + + >>> from sympy import IndexedBase + >>> from sympy.abc import x, y + >>> IndexedBase('A', shape=(x, y)).label + A + + """ + return self.args[0] + + def _sympystr(self, p): + return p.doprint(self.label) + + +class Idx(Expr): + """Represents an integer index as an ``Integer`` or integer expression. + + There are a number of ways to create an ``Idx`` object. The constructor + takes two arguments: + + ``label`` + An integer or a symbol that labels the index. + ``range`` + Optionally you can specify a range as either + + * ``Symbol`` or integer: This is interpreted as a dimension. Lower and + upper bounds are set to ``0`` and ``range - 1``, respectively. + * ``tuple``: The two elements are interpreted as the lower and upper + bounds of the range, respectively. + + Note: bounds of the range are assumed to be either integer or infinite (oo + and -oo are allowed to specify an unbounded range). If ``n`` is given as a + bound, then ``n.is_integer`` must not return false. + + For convenience, if the label is given as a string it is automatically + converted to an integer symbol. (Note: this conversion is not done for + range or dimension arguments.) + + Examples + ======== + + >>> from sympy import Idx, symbols, oo + >>> n, i, L, U = symbols('n i L U', integer=True) + + If a string is given for the label an integer ``Symbol`` is created and the + bounds are both ``None``: + + >>> idx = Idx('qwerty'); idx + qwerty + >>> idx.lower, idx.upper + (None, None) + + Both upper and lower bounds can be specified: + + >>> idx = Idx(i, (L, U)); idx + i + >>> idx.lower, idx.upper + (L, U) + + When only a single bound is given it is interpreted as the dimension + and the lower bound defaults to 0: + + >>> idx = Idx(i, n); idx.lower, idx.upper + (0, n - 1) + >>> idx = Idx(i, 4); idx.lower, idx.upper + (0, 3) + >>> idx = Idx(i, oo); idx.lower, idx.upper + (0, oo) + + """ + + is_integer = True + is_finite = True + is_real = True + is_symbol = True + is_Atom = True + _diff_wrt = True + + def __new__(cls, label, range=None, **kw_args): + + if isinstance(label, str): + label = Symbol(label, integer=True) + label, range = list(map(sympify, (label, range))) + + if label.is_Number: + if not label.is_integer: + raise TypeError("Index is not an integer number.") + return label + + if not label.is_integer: + raise TypeError("Idx object requires an integer label.") + + elif is_sequence(range): + if len(range) != 2: + raise ValueError(filldedent(""" + Idx range tuple must have length 2, but got %s""" % len(range))) + for bound in range: + if (bound.is_integer is False and bound is not S.Infinity + and bound is not S.NegativeInfinity): + raise TypeError("Idx object requires integer bounds.") + args = label, Tuple(*range) + elif isinstance(range, Expr): + if range is not S.Infinity and fuzzy_not(range.is_integer): + raise TypeError("Idx object requires an integer dimension.") + args = label, Tuple(0, range - 1) + elif range: + raise TypeError(filldedent(""" + The range must be an ordered iterable or + integer SymPy expression.""")) + else: + args = label, + + obj = Expr.__new__(cls, *args, **kw_args) + obj._assumptions["finite"] = True + obj._assumptions["real"] = True + return obj + + @property + def label(self): + """Returns the label (Integer or integer expression) of the Idx object. + + Examples + ======== + + >>> from sympy import Idx, Symbol + >>> x = Symbol('x', integer=True) + >>> Idx(x).label + x + >>> j = Symbol('j', integer=True) + >>> Idx(j).label + j + >>> Idx(j + 1).label + j + 1 + + """ + return self.args[0] + + @property + def lower(self): + """Returns the lower bound of the ``Idx``. + + Examples + ======== + + >>> from sympy import Idx + >>> Idx('j', 2).lower + 0 + >>> Idx('j', 5).lower + 0 + >>> Idx('j').lower is None + True + + """ + try: + return self.args[1][0] + except IndexError: + return + + @property + def upper(self): + """Returns the upper bound of the ``Idx``. + + Examples + ======== + + >>> from sympy import Idx + >>> Idx('j', 2).upper + 1 + >>> Idx('j', 5).upper + 4 + >>> Idx('j').upper is None + True + + """ + try: + return self.args[1][1] + except IndexError: + return + + def _sympystr(self, p): + return p.doprint(self.label) + + @property + def name(self): + return self.label.name if self.label.is_Symbol else str(self.label) + + @property + def free_symbols(self): + return {self} + + +@dispatch(Idx, Idx) +def _eval_is_ge(lhs, rhs): # noqa:F811 + + other_upper = rhs if rhs.upper is None else rhs.upper + other_lower = rhs if rhs.lower is None else rhs.lower + + if lhs.lower is not None and (lhs.lower >= other_upper) == True: + return True + if lhs.upper is not None and (lhs.upper < other_lower) == True: + return False + return None + + +@dispatch(Idx, Number) # type:ignore +def _eval_is_ge(lhs, rhs): # noqa:F811 + + other_upper = rhs + other_lower = rhs + + if lhs.lower is not None and (lhs.lower >= other_upper) == True: + return True + if lhs.upper is not None and (lhs.upper < other_lower) == True: + return False + return None + + +@dispatch(Number, Idx) # type:ignore +def _eval_is_ge(lhs, rhs): # noqa:F811 + + other_upper = lhs + other_lower = lhs + + if rhs.upper is not None and (rhs.upper <= other_lower) == True: + return True + if rhs.lower is not None and (rhs.lower > other_upper) == True: + return False + return None diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tensor.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tensor.py new file mode 100644 index 0000000000000000000000000000000000000000..579e7c7a86c2a1f18ab889af32ce0053a729ff5f --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tensor.py @@ -0,0 +1,5265 @@ +""" +This module defines tensors with abstract index notation. + +The abstract index notation has been first formalized by Penrose. + +Tensor indices are formal objects, with a tensor type; there is no +notion of index range, it is only possible to assign the dimension, +used to trace the Kronecker delta; the dimension can be a Symbol. + +The Einstein summation convention is used. +The covariant indices are indicated with a minus sign in front of the index. + +For instance the tensor ``t = p(a)*A(b,c)*q(-c)`` has the index ``c`` +contracted. + +A tensor expression ``t`` can be called; called with its +indices in sorted order it is equal to itself: +in the above example ``t(a, b) == t``; +one can call ``t`` with different indices; ``t(c, d) == p(c)*A(d,a)*q(-a)``. + +The contracted indices are dummy indices, internally they have no name, +the indices being represented by a graph-like structure. + +Tensors are put in canonical form using ``canon_bp``, which uses +the Butler-Portugal algorithm for canonicalization using the monoterm +symmetries of the tensors. + +If there is a (anti)symmetric metric, the indices can be raised and +lowered when the tensor is put in canonical form. +""" + +from __future__ import annotations +from typing import Any +from functools import reduce +from math import prod + +from abc import abstractmethod, ABC +from collections import defaultdict +import operator +import itertools + +from sympy.core.numbers import (Integer, Rational) +from sympy.combinatorics import Permutation +from sympy.combinatorics.tensor_can import get_symmetric_group_sgs, \ + bsgs_direct_product, canonicalize, riemann_bsgs +from sympy.core import Basic, Expr, sympify, Add, Mul, S +from sympy.core.cache import clear_cache +from sympy.core.containers import Tuple, Dict +from sympy.core.function import WildFunction +from sympy.core.sorting import default_sort_key +from sympy.core.symbol import Symbol, symbols, Wild +from sympy.core.sympify import CantSympify, _sympify +from sympy.core.operations import AssocOp +from sympy.external.gmpy import SYMPY_INTS +from sympy.matrices import eye +from sympy.utilities.exceptions import (sympy_deprecation_warning, + SymPyDeprecationWarning, + ignore_warnings) +from sympy.utilities.decorator import memoize_property, deprecated +from sympy.utilities.iterables import sift + + +def deprecate_data(): + sympy_deprecation_warning( + """ + The data attribute of TensorIndexType is deprecated. Use The + replace_with_arrays() method instead. + """, + deprecated_since_version="1.4", + active_deprecations_target="deprecated-tensorindextype-attrs", + stacklevel=4, + ) + +def deprecate_fun_eval(): + sympy_deprecation_warning( + """ + The Tensor.fun_eval() method is deprecated. Use + Tensor.substitute_indices() instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensor-fun-eval", + stacklevel=4, + ) + + +def deprecate_call(): + sympy_deprecation_warning( + """ + Calling a tensor like Tensor(*indices) is deprecated. Use + Tensor.substitute_indices() instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensor-fun-eval", + stacklevel=4, + ) + + +class _IndexStructure(CantSympify): + """ + This class handles the indices (free and dummy ones). It contains the + algorithms to manage the dummy indices replacements and contractions of + free indices under multiplications of tensor expressions, as well as stuff + related to canonicalization sorting, getting the permutation of the + expression and so on. It also includes tools to get the ``TensorIndex`` + objects corresponding to the given index structure. + """ + + def __init__(self, free, dum, index_types, indices, canon_bp=False): + self.free = free + self.dum = dum + self.index_types = index_types + self.indices = indices + self._ext_rank = len(self.free) + 2*len(self.dum) + self.dum.sort(key=lambda x: x[0]) + + @staticmethod + def from_indices(*indices): + """ + Create a new ``_IndexStructure`` object from a list of ``indices``. + + Explanation + =========== + + ``indices`` ``TensorIndex`` objects, the indices. Contractions are + detected upon construction. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, _IndexStructure + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2, m3 = tensor_indices('m0,m1,m2,m3', Lorentz) + >>> _IndexStructure.from_indices(m0, m1, -m1, m3) + _IndexStructure([(m0, 0), (m3, 3)], [(1, 2)], [Lorentz, Lorentz, Lorentz, Lorentz]) + """ + + free, dum = _IndexStructure._free_dum_from_indices(*indices) + index_types = [i.tensor_index_type for i in indices] + indices = _IndexStructure._replace_dummy_names(indices, free, dum) + return _IndexStructure(free, dum, index_types, indices) + + @staticmethod + def from_components_free_dum(components, free, dum): + index_types = [] + for component in components: + index_types.extend(component.index_types) + indices = _IndexStructure.generate_indices_from_free_dum_index_types(free, dum, index_types) + return _IndexStructure(free, dum, index_types, indices) + + @staticmethod + def _free_dum_from_indices(*indices): + """ + Convert ``indices`` into ``free``, ``dum`` for single component tensor. + + Explanation + =========== + + ``free`` list of tuples ``(index, pos, 0)``, + where ``pos`` is the position of index in + the list of indices formed by the component tensors + + ``dum`` list of tuples ``(pos_contr, pos_cov, 0, 0)`` + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, \ + _IndexStructure + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2, m3 = tensor_indices('m0,m1,m2,m3', Lorentz) + >>> _IndexStructure._free_dum_from_indices(m0, m1, -m1, m3) + ([(m0, 0), (m3, 3)], [(1, 2)]) + """ + n = len(indices) + if n == 1: + return [(indices[0], 0)], [] + + # find the positions of the free indices and of the dummy indices + free = [True]*len(indices) + index_dict = {} + dum = [] + for i, index in enumerate(indices): + name = index.name + typ = index.tensor_index_type + contr = index.is_up + if (name, typ) in index_dict: + # found a pair of dummy indices + is_contr, pos = index_dict[(name, typ)] + # check consistency and update free + if is_contr: + if contr: + raise ValueError('two equal contravariant indices in slots %d and %d' %(pos, i)) + else: + free[pos] = False + free[i] = False + else: + if contr: + free[pos] = False + free[i] = False + else: + raise ValueError('two equal covariant indices in slots %d and %d' %(pos, i)) + if contr: + dum.append((i, pos)) + else: + dum.append((pos, i)) + else: + index_dict[(name, typ)] = index.is_up, i + + free = [(index, i) for i, index in enumerate(indices) if free[i]] + free.sort() + return free, dum + + def get_indices(self): + """ + Get a list of indices, creating new tensor indices to complete dummy indices. + """ + return self.indices[:] + + @staticmethod + def generate_indices_from_free_dum_index_types(free, dum, index_types): + indices = [None]*(len(free)+2*len(dum)) + for idx, pos in free: + indices[pos] = idx + + generate_dummy_name = _IndexStructure._get_generator_for_dummy_indices(free) + for pos1, pos2 in dum: + typ1 = index_types[pos1] + indname = generate_dummy_name(typ1) + indices[pos1] = TensorIndex(indname, typ1, True) + indices[pos2] = TensorIndex(indname, typ1, False) + + return _IndexStructure._replace_dummy_names(indices, free, dum) + + @staticmethod + def _get_generator_for_dummy_indices(free): + cdt = defaultdict(int) + # if the free indices have names with dummy_name, start with an + # index higher than those for the dummy indices + # to avoid name collisions + for indx, ipos in free: + if indx.name.split('_')[0] == indx.tensor_index_type.dummy_name: + cdt[indx.tensor_index_type] = max(cdt[indx.tensor_index_type], int(indx.name.split('_')[1]) + 1) + + def dummy_name_gen(tensor_index_type): + nd = str(cdt[tensor_index_type]) + cdt[tensor_index_type] += 1 + return tensor_index_type.dummy_name + '_' + nd + + return dummy_name_gen + + @staticmethod + def _replace_dummy_names(indices, free, dum): + dum.sort(key=lambda x: x[0]) + new_indices = list(indices) + assert len(indices) == len(free) + 2*len(dum) + generate_dummy_name = _IndexStructure._get_generator_for_dummy_indices(free) + for ipos1, ipos2 in dum: + typ1 = new_indices[ipos1].tensor_index_type + indname = generate_dummy_name(typ1) + new_indices[ipos1] = TensorIndex(indname, typ1, True) + new_indices[ipos2] = TensorIndex(indname, typ1, False) + return new_indices + + def get_free_indices(self) -> list[TensorIndex]: + """ + Get a list of free indices. + """ + # get sorted indices according to their position: + free = sorted(self.free, key=lambda x: x[1]) + return [i[0] for i in free] + + def __str__(self): + return "_IndexStructure({}, {}, {})".format(self.free, self.dum, self.index_types) + + def __repr__(self): + return self.__str__() + + def _get_sorted_free_indices_for_canon(self): + sorted_free = self.free[:] + sorted_free.sort(key=lambda x: x[0]) + return sorted_free + + def _get_sorted_dum_indices_for_canon(self): + return sorted(self.dum, key=lambda x: x[0]) + + def _get_lexicographically_sorted_index_types(self): + permutation = self.indices_canon_args()[0] + index_types = [None]*self._ext_rank + for i, it in enumerate(self.index_types): + index_types[permutation(i)] = it + return index_types + + def _get_lexicographically_sorted_indices(self): + permutation = self.indices_canon_args()[0] + indices = [None]*self._ext_rank + for i, it in enumerate(self.indices): + indices[permutation(i)] = it + return indices + + def perm2tensor(self, g, is_canon_bp=False): + """ + Returns a ``_IndexStructure`` instance corresponding to the permutation ``g``. + + Explanation + =========== + + ``g`` permutation corresponding to the tensor in the representation + used in canonicalization + + ``is_canon_bp`` if True, then ``g`` is the permutation + corresponding to the canonical form of the tensor + """ + sorted_free = [i[0] for i in self._get_sorted_free_indices_for_canon()] + lex_index_types = self._get_lexicographically_sorted_index_types() + lex_indices = self._get_lexicographically_sorted_indices() + nfree = len(sorted_free) + rank = self._ext_rank + dum = [[None]*2 for i in range((rank - nfree)//2)] + free = [] + + index_types = [None]*rank + indices = [None]*rank + for i in range(rank): + gi = g[i] + index_types[i] = lex_index_types[gi] + indices[i] = lex_indices[gi] + if gi < nfree: + ind = sorted_free[gi] + assert index_types[i] == sorted_free[gi].tensor_index_type + free.append((ind, i)) + else: + j = gi - nfree + idum, cov = divmod(j, 2) + if cov: + dum[idum][1] = i + else: + dum[idum][0] = i + dum = [tuple(x) for x in dum] + + return _IndexStructure(free, dum, index_types, indices) + + def indices_canon_args(self): + """ + Returns ``(g, dummies, msym, v)``, the entries of ``canonicalize`` + + See ``canonicalize`` in ``tensor_can.py`` in combinatorics module. + """ + # to be called after sorted_components + from sympy.combinatorics.permutations import _af_new + n = self._ext_rank + g = [None]*n + [n, n+1] + + # Converts the symmetry of the metric into msym from .canonicalize() + # method in the combinatorics module + def metric_symmetry_to_msym(metric): + if metric is None: + return None + sym = metric.symmetry + if sym == TensorSymmetry.fully_symmetric(2): + return 0 + if sym == TensorSymmetry.fully_symmetric(-2): + return 1 + return None + + # ordered indices: first the free indices, ordered by types + # then the dummy indices, ordered by types and contravariant before + # covariant + # g[position in tensor] = position in ordered indices + for i, (indx, ipos) in enumerate(self._get_sorted_free_indices_for_canon()): + g[ipos] = i + pos = len(self.free) + j = len(self.free) + dummies = [] + prev = None + a = [] + msym = [] + for ipos1, ipos2 in self._get_sorted_dum_indices_for_canon(): + g[ipos1] = j + g[ipos2] = j + 1 + j += 2 + typ = self.index_types[ipos1] + if typ != prev: + if a: + dummies.append(a) + a = [pos, pos + 1] + prev = typ + msym.append(metric_symmetry_to_msym(typ.metric)) + else: + a.extend([pos, pos + 1]) + pos += 2 + if a: + dummies.append(a) + + return _af_new(g), dummies, msym + + +def components_canon_args(components): + numtyp = [] + prev = None + for t in components: + if t == prev: + numtyp[-1][1] += 1 + else: + prev = t + numtyp.append([prev, 1]) + v = [] + for h, n in numtyp: + if h.comm in (0, 1): + comm = h.comm + else: + comm = TensorManager.get_comm(h.comm, h.comm) + v.append((h.symmetry.base, h.symmetry.generators, n, comm)) + return v + + +class _TensorDataLazyEvaluator(CantSympify): + """ + EXPERIMENTAL: do not rely on this class, it may change without deprecation + warnings in future versions of SymPy. + + Explanation + =========== + + This object contains the logic to associate components data to a tensor + expression. Components data are set via the ``.data`` property of tensor + expressions, is stored inside this class as a mapping between the tensor + expression and the ``ndarray``. + + Computations are executed lazily: whereas the tensor expressions can have + contractions, tensor products, and additions, components data are not + computed until they are accessed by reading the ``.data`` property + associated to the tensor expression. + """ + _substitutions_dict: dict[Any, Any] = {} + _substitutions_dict_tensmul: dict[Any, Any] = {} + + def __getitem__(self, key): + dat = self._get(key) + if dat is None: + return None + + from .array import NDimArray + if not isinstance(dat, NDimArray): + return dat + + if dat.rank() == 0: + return dat[()] + elif dat.rank() == 1 and len(dat) == 1: + return dat[0] + return dat + + def _get(self, key): + """ + Retrieve ``data`` associated with ``key``. + + Explanation + =========== + + This algorithm looks into ``self._substitutions_dict`` for all + ``TensorHead`` in the ``TensExpr`` (or just ``TensorHead`` if key is a + TensorHead instance). It reconstructs the components data that the + tensor expression should have by performing on components data the + operations that correspond to the abstract tensor operations applied. + + Metric tensor is handled in a different manner: it is pre-computed in + ``self._substitutions_dict_tensmul``. + """ + if key in self._substitutions_dict: + return self._substitutions_dict[key] + + if isinstance(key, TensorHead): + return None + + if isinstance(key, Tensor): + # special case to handle metrics. Metric tensors cannot be + # constructed through contraction by the metric, their + # components show if they are a matrix or its inverse. + signature = tuple([i.is_up for i in key.get_indices()]) + srch = (key.component,) + signature + if srch in self._substitutions_dict_tensmul: + return self._substitutions_dict_tensmul[srch] + array_list = [self.data_from_tensor(key)] + return self.data_contract_dum(array_list, key.dum, key.ext_rank) + + if isinstance(key, TensMul): + tensmul_args = key.args + if len(tensmul_args) == 1 and len(tensmul_args[0].components) == 1: + # special case to handle metrics. Metric tensors cannot be + # constructed through contraction by the metric, their + # components show if they are a matrix or its inverse. + signature = tuple([i.is_up for i in tensmul_args[0].get_indices()]) + srch = (tensmul_args[0].components[0],) + signature + if srch in self._substitutions_dict_tensmul: + return self._substitutions_dict_tensmul[srch] + #data_list = [self.data_from_tensor(i) for i in tensmul_args if isinstance(i, TensExpr)] + data_list = [self.data_from_tensor(i) if isinstance(i, Tensor) else i.data for i in tensmul_args if isinstance(i, TensExpr)] + coeff = prod([i for i in tensmul_args if not isinstance(i, TensExpr)]) + if all(i is None for i in data_list): + return None + if any(i is None for i in data_list): + raise ValueError("Mixing tensors with associated components "\ + "data with tensors without components data") + data_result = self.data_contract_dum(data_list, key.dum, key.ext_rank) + return coeff*data_result + + if isinstance(key, TensAdd): + data_list = [] + free_args_list = [] + for arg in key.args: + if isinstance(arg, TensExpr): + data_list.append(arg.data) + free_args_list.append([x[0] for x in arg.free]) + else: + data_list.append(arg) + free_args_list.append([]) + if all(i is None for i in data_list): + return None + if any(i is None for i in data_list): + raise ValueError("Mixing tensors with associated components "\ + "data with tensors without components data") + + sum_list = [] + from .array import permutedims + for data, free_args in zip(data_list, free_args_list): + if len(free_args) < 2: + sum_list.append(data) + else: + free_args_pos = {y: x for x, y in enumerate(free_args)} + axes = [free_args_pos[arg] for arg in key.free_args] + sum_list.append(permutedims(data, axes)) + return reduce(lambda x, y: x+y, sum_list) + + return None + + @staticmethod + def data_contract_dum(ndarray_list, dum, ext_rank): + from .array import tensorproduct, tensorcontraction, MutableDenseNDimArray + arrays = list(map(MutableDenseNDimArray, ndarray_list)) + prodarr = tensorproduct(*arrays) + return tensorcontraction(prodarr, *dum) + + def data_tensorhead_from_tensmul(self, data, tensmul, tensorhead): + """ + This method is used when assigning components data to a ``TensMul`` + object, it converts components data to a fully contravariant ndarray, + which is then stored according to the ``TensorHead`` key. + """ + if data is None: + return None + + return self._correct_signature_from_indices( + data, + tensmul.get_indices(), + tensmul.free, + tensmul.dum, + True) + + def data_from_tensor(self, tensor): + """ + This method corrects the components data to the right signature + (covariant/contravariant) using the metric associated with each + ``TensorIndexType``. + """ + tensorhead = tensor.component + + if tensorhead.data is None: + return None + + return self._correct_signature_from_indices( + tensorhead.data, + tensor.get_indices(), + tensor.free, + tensor.dum) + + def _assign_data_to_tensor_expr(self, key, data): + if isinstance(key, TensAdd): + raise ValueError('cannot assign data to TensAdd') + # here it is assumed that `key` is a `TensMul` instance. + if len(key.components) != 1: + raise ValueError('cannot assign data to TensMul with multiple components') + tensorhead = key.components[0] + newdata = self.data_tensorhead_from_tensmul(data, key, tensorhead) + return tensorhead, newdata + + def _check_permutations_on_data(self, tens, data): + from .array import permutedims + from .array.arrayop import Flatten + + if isinstance(tens, TensorHead): + rank = tens.rank + generators = tens.symmetry.generators + elif isinstance(tens, Tensor): + rank = tens.rank + generators = tens.components[0].symmetry.generators + elif isinstance(tens, TensorIndexType): + rank = tens.metric.rank + generators = tens.metric.symmetry.generators + + # Every generator is a permutation, check that by permuting the array + # by that permutation, the array will be the same, except for a + # possible sign change if the permutation admits it. + for gener in generators: + sign_change = +1 if (gener(rank) == rank) else -1 + data_swapped = data + last_data = data + permute_axes = list(map(gener, range(rank))) + # the order of a permutation is the number of times to get the + # identity by applying that permutation. + for i in range(gener.order()-1): + data_swapped = permutedims(data_swapped, permute_axes) + # if any value in the difference array is non-zero, raise an error: + if any(Flatten(last_data - sign_change*data_swapped)): + raise ValueError("Component data symmetry structure error") + last_data = data_swapped + + def __setitem__(self, key, value): + """ + Set the components data of a tensor object/expression. + + Explanation + =========== + + Components data are transformed to the all-contravariant form and stored + with the corresponding ``TensorHead`` object. If a ``TensorHead`` object + cannot be uniquely identified, it will raise an error. + """ + data = _TensorDataLazyEvaluator.parse_data(value) + self._check_permutations_on_data(key, data) + + # TensorHead and TensorIndexType can be assigned data directly, while + # TensMul must first convert data to a fully contravariant form, and + # assign it to its corresponding TensorHead single component. + if not isinstance(key, (TensorHead, TensorIndexType)): + key, data = self._assign_data_to_tensor_expr(key, data) + + if isinstance(key, TensorHead): + for dim, indextype in zip(data.shape, key.index_types): + if indextype.data is None: + raise ValueError("index type {} has no components data"\ + " associated (needed to raise/lower index)".format(indextype)) + if not indextype.dim.is_number: + continue + if dim != indextype.dim: + raise ValueError("wrong dimension of ndarray") + self._substitutions_dict[key] = data + + def __delitem__(self, key): + del self._substitutions_dict[key] + + def __contains__(self, key): + return key in self._substitutions_dict + + def add_metric_data(self, metric, data): + """ + Assign data to the ``metric`` tensor. The metric tensor behaves in an + anomalous way when raising and lowering indices. + + Explanation + =========== + + A fully covariant metric is the inverse transpose of the fully + contravariant metric (it is meant matrix inverse). If the metric is + symmetric, the transpose is not necessary and mixed + covariant/contravariant metrics are Kronecker deltas. + """ + # hard assignment, data should not be added to `TensorHead` for metric: + # the problem with `TensorHead` is that the metric is anomalous, i.e. + # raising and lowering the index means considering the metric or its + # inverse, this is not the case for other tensors. + self._substitutions_dict_tensmul[metric, True, True] = data + inverse_transpose = self.inverse_transpose_matrix(data) + # in symmetric spaces, the transpose is the same as the original matrix, + # the full covariant metric tensor is the inverse transpose, so this + # code will be able to handle non-symmetric metrics. + self._substitutions_dict_tensmul[metric, False, False] = inverse_transpose + # now mixed cases, these are identical to the unit matrix if the metric + # is symmetric. + m = data.tomatrix() + invt = inverse_transpose.tomatrix() + self._substitutions_dict_tensmul[metric, True, False] = m * invt + self._substitutions_dict_tensmul[metric, False, True] = invt * m + + @staticmethod + def _flip_index_by_metric(data, metric, pos): + from .array import tensorproduct, tensorcontraction + + mdim = metric.rank() + ddim = data.rank() + + if pos == 0: + data = tensorcontraction( + tensorproduct( + metric, + data + ), + (1, mdim+pos) + ) + else: + data = tensorcontraction( + tensorproduct( + data, + metric + ), + (pos, ddim) + ) + return data + + @staticmethod + def inverse_matrix(ndarray): + m = ndarray.tomatrix().inv() + return _TensorDataLazyEvaluator.parse_data(m) + + @staticmethod + def inverse_transpose_matrix(ndarray): + m = ndarray.tomatrix().inv().T + return _TensorDataLazyEvaluator.parse_data(m) + + @staticmethod + def _correct_signature_from_indices(data, indices, free, dum, inverse=False): + """ + Utility function to correct the values inside the components data + ndarray according to whether indices are covariant or contravariant. + + It uses the metric matrix to lower values of covariant indices. + """ + # change the ndarray values according covariantness/contravariantness of the indices + # use the metric + for i, indx in enumerate(indices): + if not indx.is_up and not inverse: + data = _TensorDataLazyEvaluator._flip_index_by_metric(data, indx.tensor_index_type.data, i) + elif not indx.is_up and inverse: + data = _TensorDataLazyEvaluator._flip_index_by_metric( + data, + _TensorDataLazyEvaluator.inverse_matrix(indx.tensor_index_type.data), + i + ) + return data + + @staticmethod + def _sort_data_axes(old, new): + from .array import permutedims + + new_data = old.data.copy() + + old_free = [i[0] for i in old.free] + new_free = [i[0] for i in new.free] + + for i in range(len(new_free)): + for j in range(i, len(old_free)): + if old_free[j] == new_free[i]: + old_free[i], old_free[j] = old_free[j], old_free[i] + new_data = permutedims(new_data, (i, j)) + break + return new_data + + @staticmethod + def add_rearrange_tensmul_parts(new_tensmul, old_tensmul): + def sorted_compo(): + return _TensorDataLazyEvaluator._sort_data_axes(old_tensmul, new_tensmul) + + _TensorDataLazyEvaluator._substitutions_dict[new_tensmul] = sorted_compo() + + @staticmethod + def parse_data(data): + """ + Transform ``data`` to array. The parameter ``data`` may + contain data in various formats, e.g. nested lists, SymPy ``Matrix``, + and so on. + + Examples + ======== + + >>> from sympy.tensor.tensor import _TensorDataLazyEvaluator + >>> _TensorDataLazyEvaluator.parse_data([1, 3, -6, 12]) + [1, 3, -6, 12] + + >>> _TensorDataLazyEvaluator.parse_data([[1, 2], [4, 7]]) + [[1, 2], [4, 7]] + """ + from .array import MutableDenseNDimArray + + if not isinstance(data, MutableDenseNDimArray): + if len(data) == 2 and hasattr(data[0], '__call__'): + data = MutableDenseNDimArray(data[0], data[1]) + else: + data = MutableDenseNDimArray(data) + return data + +_tensor_data_substitution_dict = _TensorDataLazyEvaluator() + + +class _TensorManager: + """ + Class to manage tensor properties. + + Notes + ===== + + Tensors belong to tensor commutation groups; each group has a label + ``comm``; there are predefined labels: + + ``0`` tensors commuting with any other tensor + + ``1`` tensors anticommuting among themselves + + ``2`` tensors not commuting, apart with those with ``comm=0`` + + Other groups can be defined using ``set_comm``; tensors in those + groups commute with those with ``comm=0``; by default they + do not commute with any other group. + """ + def __init__(self): + self._comm_init() + + def _comm_init(self): + self._comm = [{} for i in range(3)] + for i in range(3): + self._comm[0][i] = 0 + self._comm[i][0] = 0 + self._comm[1][1] = 1 + self._comm[2][1] = None + self._comm[1][2] = None + self._comm_symbols2i = {0:0, 1:1, 2:2} + self._comm_i2symbol = {0:0, 1:1, 2:2} + + @property + def comm(self): + return self._comm + + def comm_symbols2i(self, i): + """ + Get the commutation group number corresponding to ``i``. + + ``i`` can be a symbol or a number or a string. + + If ``i`` is not already defined its commutation group number + is set. + """ + if i not in self._comm_symbols2i: + n = len(self._comm) + self._comm.append({}) + self._comm[n][0] = 0 + self._comm[0][n] = 0 + self._comm_symbols2i[i] = n + self._comm_i2symbol[n] = i + return n + return self._comm_symbols2i[i] + + def comm_i2symbol(self, i): + """ + Returns the symbol corresponding to the commutation group number. + """ + return self._comm_i2symbol[i] + + def set_comm(self, i, j, c): + """ + Set the commutation parameter ``c`` for commutation groups ``i, j``. + + Parameters + ========== + + i, j : symbols representing commutation groups + + c : group commutation number + + Notes + ===== + + ``i, j`` can be symbols, strings or numbers, + apart from ``0, 1`` and ``2`` which are reserved respectively + for commuting, anticommuting tensors and tensors not commuting + with any other group apart with the commuting tensors. + For the remaining cases, use this method to set the commutation rules; + by default ``c=None``. + + The group commutation number ``c`` is assigned in correspondence + to the group commutation symbols; it can be + + 0 commuting + + 1 anticommuting + + None no commutation property + + Examples + ======== + + ``G`` and ``GH`` do not commute with themselves and commute with + each other; A is commuting. + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorHead, TensorManager, TensorSymmetry + >>> Lorentz = TensorIndexType('Lorentz') + >>> i0,i1,i2,i3,i4 = tensor_indices('i0:5', Lorentz) + >>> A = TensorHead('A', [Lorentz]) + >>> G = TensorHead('G', [Lorentz], TensorSymmetry.no_symmetry(1), 'Gcomm') + >>> GH = TensorHead('GH', [Lorentz], TensorSymmetry.no_symmetry(1), 'GHcomm') + >>> TensorManager.set_comm('Gcomm', 'GHcomm', 0) + >>> (GH(i1)*G(i0)).canon_bp() + G(i0)*GH(i1) + >>> (G(i1)*G(i0)).canon_bp() + G(i1)*G(i0) + >>> (G(i1)*A(i0)).canon_bp() + A(i0)*G(i1) + """ + if c not in (0, 1, None): + raise ValueError('`c` can assume only the values 0, 1 or None') + + i = sympify(i) + j = sympify(j) + + if i not in self._comm_symbols2i: + n = len(self._comm) + self._comm.append({}) + self._comm[n][0] = 0 + self._comm[0][n] = 0 + self._comm_symbols2i[i] = n + self._comm_i2symbol[n] = i + if j not in self._comm_symbols2i: + n = len(self._comm) + self._comm.append({}) + self._comm[0][n] = 0 + self._comm[n][0] = 0 + self._comm_symbols2i[j] = n + self._comm_i2symbol[n] = j + ni = self._comm_symbols2i[i] + nj = self._comm_symbols2i[j] + self._comm[ni][nj] = c + self._comm[nj][ni] = c + + """ + Cached sympy functions (e.g. expand) may have cached the results of + expressions involving tensors, but those results may not be valid after + changing the commutation properties. To stay on the safe side, we clear + the cache of all functions. + """ + clear_cache() + + def set_comms(self, *args): + """ + Set the commutation group numbers ``c`` for symbols ``i, j``. + + Parameters + ========== + + args : sequence of ``(i, j, c)`` + """ + for i, j, c in args: + self.set_comm(i, j, c) + + def get_comm(self, i, j): + """ + Return the commutation parameter for commutation group numbers ``i, j`` + + see ``_TensorManager.set_comm`` + """ + return self._comm[i].get(j, 0 if i == 0 or j == 0 else None) + + def clear(self): + """ + Clear the TensorManager. + """ + self._comm_init() + + +TensorManager = _TensorManager() + + +class TensorIndexType(Basic): + """ + A TensorIndexType is characterized by its name and its metric. + + Parameters + ========== + + name : name of the tensor type + dummy_name : name of the head of dummy indices + dim : dimension, it can be a symbol or an integer or ``None`` + eps_dim : dimension of the epsilon tensor + metric_symmetry : integer that denotes metric symmetry or ``None`` for no metric + metric_name : string with the name of the metric tensor + + Attributes + ========== + + ``metric`` : the metric tensor + ``delta`` : ``Kronecker delta`` + ``epsilon`` : the ``Levi-Civita epsilon`` tensor + ``data`` : (deprecated) a property to add ``ndarray`` values, to work in a specified basis. + + Notes + ===== + + The possible values of the ``metric_symmetry`` parameter are: + + ``1`` : metric tensor is fully symmetric + ``0`` : metric tensor possesses no index symmetry + ``-1`` : metric tensor is fully antisymmetric + ``None``: there is no metric tensor (metric equals to ``None``) + + The metric is assumed to be symmetric by default. It can also be set + to a custom tensor by the ``.set_metric()`` method. + + If there is a metric the metric is used to raise and lower indices. + + In the case of non-symmetric metric, the following raising and + lowering conventions will be adopted: + + ``psi(a) = g(a, b)*psi(-b); chi(-a) = chi(b)*g(-b, -a)`` + + From these it is easy to find: + + ``g(-a, b) = delta(-a, b)`` + + where ``delta(-a, b) = delta(b, -a)`` is the ``Kronecker delta`` + (see ``TensorIndex`` for the conventions on indices). + For antisymmetric metrics there is also the following equality: + + ``g(a, -b) = -delta(a, -b)`` + + If there is no metric it is not possible to raise or lower indices; + e.g. the index of the defining representation of ``SU(N)`` + is 'covariant' and the conjugate representation is + 'contravariant'; for ``N > 2`` they are linearly independent. + + ``eps_dim`` is by default equal to ``dim``, if the latter is an integer; + else it can be assigned (for use in naive dimensional regularization); + if ``eps_dim`` is not an integer ``epsilon`` is ``None``. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> Lorentz.metric + metric(Lorentz,Lorentz) + """ + + def __new__(cls, name, dummy_name=None, dim=None, eps_dim=None, + metric_symmetry=1, metric_name='metric', **kwargs): + if 'dummy_fmt' in kwargs: + dummy_fmt = kwargs['dummy_fmt'] + sympy_deprecation_warning( + f""" + The dummy_fmt keyword to TensorIndexType is deprecated. Use + dummy_name={dummy_fmt} instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensorindextype-dummy-fmt", + ) + dummy_name = dummy_fmt + + if isinstance(name, str): + name = Symbol(name) + + if dummy_name is None: + dummy_name = str(name)[0] + if isinstance(dummy_name, str): + dummy_name = Symbol(dummy_name) + + if dim is None: + dim = Symbol("dim_" + dummy_name.name) + else: + dim = sympify(dim) + + if eps_dim is None: + eps_dim = dim + else: + eps_dim = sympify(eps_dim) + + metric_symmetry = sympify(metric_symmetry) + + if isinstance(metric_name, str): + metric_name = Symbol(metric_name) + + if 'metric' in kwargs: + SymPyDeprecationWarning( + """ + The 'metric' keyword argument to TensorIndexType is + deprecated. Use the 'metric_symmetry' keyword argument or the + TensorIndexType.set_metric() method instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensorindextype-metric", + ) + metric = kwargs.get('metric') + if metric is not None: + if metric in (True, False, 0, 1): + metric_name = 'metric' + #metric_antisym = metric + else: + metric_name = metric.name + #metric_antisym = metric.antisym + + if metric: + metric_symmetry = -1 + else: + metric_symmetry = 1 + + obj = Basic.__new__(cls, name, dummy_name, dim, eps_dim, + metric_symmetry, metric_name) + + obj._autogenerated = [] + return obj + + @property + def name(self): + return self.args[0].name + + @property + def dummy_name(self): + return self.args[1].name + + @property + def dim(self): + return self.args[2] + + @property + def eps_dim(self): + return self.args[3] + + @memoize_property + def metric(self): + metric_symmetry = self.args[4] + metric_name = self.args[5] + if metric_symmetry is None: + return None + + if metric_symmetry == 0: + symmetry = TensorSymmetry.no_symmetry(2) + elif metric_symmetry == 1: + symmetry = TensorSymmetry.fully_symmetric(2) + elif metric_symmetry == -1: + symmetry = TensorSymmetry.fully_symmetric(-2) + + return TensorHead(metric_name, [self]*2, symmetry) + + @memoize_property + def delta(self): + return TensorHead('KD', [self]*2, TensorSymmetry.fully_symmetric(2)) + + @memoize_property + def epsilon(self): + if not isinstance(self.eps_dim, (SYMPY_INTS, Integer)): + return None + symmetry = TensorSymmetry.fully_symmetric(-self.eps_dim) + return TensorHead('Eps', [self]*self.eps_dim, symmetry) + + def set_metric(self, tensor): + self._metric = tensor + + def __lt__(self, other): + return self.name < other.name + + def __str__(self): + return self.name + + __repr__ = __str__ + + # Everything below this line is deprecated + + @property + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return _tensor_data_substitution_dict[self] + + @data.setter + def data(self, data): + deprecate_data() + # This assignment is a bit controversial, should metric components be assigned + # to the metric only or also to the TensorIndexType object? The advantage here + # is the ability to assign a 1D array and transform it to a 2D diagonal array. + from .array import MutableDenseNDimArray + + data = _TensorDataLazyEvaluator.parse_data(data) + if data.rank() > 2: + raise ValueError("data have to be of rank 1 (diagonal metric) or 2.") + if data.rank() == 1: + if self.dim.is_number: + nda_dim = data.shape[0] + if nda_dim != self.dim: + raise ValueError("Dimension mismatch") + + dim = data.shape[0] + newndarray = MutableDenseNDimArray.zeros(dim, dim) + for i, val in enumerate(data): + newndarray[i, i] = val + data = newndarray + dim1, dim2 = data.shape + if dim1 != dim2: + raise ValueError("Non-square matrix tensor.") + if self.dim.is_number: + if self.dim != dim1: + raise ValueError("Dimension mismatch") + _tensor_data_substitution_dict[self] = data + _tensor_data_substitution_dict.add_metric_data(self.metric, data) + with ignore_warnings(SymPyDeprecationWarning): + delta = self.get_kronecker_delta() + i1 = TensorIndex('i1', self) + i2 = TensorIndex('i2', self) + with ignore_warnings(SymPyDeprecationWarning): + delta(i1, -i2).data = _TensorDataLazyEvaluator.parse_data(eye(dim1)) + + @data.deleter + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if self in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self] + if self.metric in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self.metric] + + @deprecated( + """ + The TensorIndexType.get_kronecker_delta() method is deprecated. Use + the TensorIndexType.delta attribute instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensorindextype-methods", + ) + def get_kronecker_delta(self): + sym2 = TensorSymmetry(get_symmetric_group_sgs(2)) + delta = TensorHead('KD', [self]*2, sym2) + return delta + + @deprecated( + """ + The TensorIndexType.get_epsilon() method is deprecated. Use + the TensorIndexType.epsilon attribute instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensorindextype-methods", + ) + def get_epsilon(self): + if not isinstance(self._eps_dim, (SYMPY_INTS, Integer)): + return None + sym = TensorSymmetry(get_symmetric_group_sgs(self._eps_dim, 1)) + epsilon = TensorHead('Eps', [self]*self._eps_dim, sym) + return epsilon + + def _components_data_full_destroy(self): + """ + EXPERIMENTAL: do not rely on this API method. + + This destroys components data associated to the ``TensorIndexType``, if + any, specifically: + + * metric tensor data + * Kronecker tensor data + """ + if self in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self] + + def delete_tensmul_data(key): + if key in _tensor_data_substitution_dict._substitutions_dict_tensmul: + del _tensor_data_substitution_dict._substitutions_dict_tensmul[key] + + # delete metric data: + delete_tensmul_data((self.metric, True, True)) + delete_tensmul_data((self.metric, True, False)) + delete_tensmul_data((self.metric, False, True)) + delete_tensmul_data((self.metric, False, False)) + + # delete delta tensor data: + delta = self.get_kronecker_delta() + if delta in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[delta] + + +class TensorIndex(Basic): + """ + Represents a tensor index + + Parameters + ========== + + name : name of the index, or ``True`` if you want it to be automatically assigned + tensor_index_type : ``TensorIndexType`` of the index + is_up : flag for contravariant index (is_up=True by default) + + Attributes + ========== + + ``name`` + ``tensor_index_type`` + ``is_up`` + + Notes + ===== + + Tensor indices are contracted with the Einstein summation convention. + + An index can be in contravariant or in covariant form; in the latter + case it is represented prepending a ``-`` to the index name. Adding + ``-`` to a covariant (is_up=False) index makes it contravariant. + + Dummy indices have a name with head given by + ``tensor_inde_type.dummy_name`` with underscore and a number. + + Similar to ``symbols`` multiple contravariant indices can be created + at once using ``tensor_indices(s, typ)``, where ``s`` is a string + of names. + + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, TensorIndex, TensorHead, tensor_indices + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> mu = TensorIndex('mu', Lorentz, is_up=False) + >>> nu, rho = tensor_indices('nu, rho', Lorentz) + >>> A = TensorHead('A', [Lorentz, Lorentz]) + >>> A(mu, nu) + A(-mu, nu) + >>> A(-mu, -rho) + A(mu, -rho) + >>> A(mu, -mu) + A(-L_0, L_0) + """ + def __new__(cls, name, tensor_index_type, is_up=True): + if isinstance(name, str): + name_symbol = Symbol(name) + elif isinstance(name, Symbol): + name_symbol = name + elif name is True: + name = "_i{}".format(len(tensor_index_type._autogenerated)) + name_symbol = Symbol(name) + tensor_index_type._autogenerated.append(name_symbol) + else: + raise ValueError("invalid name") + + is_up = sympify(is_up) + return Basic.__new__(cls, name_symbol, tensor_index_type, is_up) + + @property + def name(self): + return self.args[0].name + + @property + def tensor_index_type(self): + return self.args[1] + + @property + def is_up(self): + return self.args[2] + + def _print(self): + s = self.name + if not self.is_up: + s = '-%s' % s + return s + + def __lt__(self, other): + return ((self.tensor_index_type, self.name) < + (other.tensor_index_type, other.name)) + + def __neg__(self): + t1 = TensorIndex(self.name, self.tensor_index_type, + (not self.is_up)) + return t1 + + +def tensor_indices(s, typ): + """ + Returns list of tensor indices given their names and their types. + + Parameters + ========== + + s : string of comma separated names of indices + + typ : ``TensorIndexType`` of the indices + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> a, b, c, d = tensor_indices('a,b,c,d', Lorentz) + """ + if isinstance(s, str): + a = [x.name for x in symbols(s, seq=True)] + else: + raise ValueError('expecting a string') + + tilist = [TensorIndex(i, typ) for i in a] + if len(tilist) == 1: + return tilist[0] + return tilist + + +class TensorSymmetry(Basic): + """ + Monoterm symmetry of a tensor (i.e. any symmetric or anti-symmetric + index permutation). For the relevant terminology see ``tensor_can.py`` + section of the combinatorics module. + + Parameters + ========== + + bsgs : tuple ``(base, sgs)`` BSGS of the symmetry of the tensor + + Attributes + ========== + + ``base`` : base of the BSGS + ``generators`` : generators of the BSGS + ``rank`` : rank of the tensor + + Notes + ===== + + A tensor can have an arbitrary monoterm symmetry provided by its BSGS. + Multiterm symmetries, like the cyclic symmetry of the Riemann tensor + (i.e., Bianchi identity), are not covered. See combinatorics module for + information on how to generate BSGS for a general index permutation group. + Simple symmetries can be generated using built-in methods. + + See Also + ======== + + sympy.combinatorics.tensor_can.get_symmetric_group_sgs + + Examples + ======== + + Define a symmetric tensor of rank 2 + + >>> from sympy.tensor.tensor import TensorIndexType, TensorSymmetry, get_symmetric_group_sgs, TensorHead + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> sym = TensorSymmetry(get_symmetric_group_sgs(2)) + >>> T = TensorHead('T', [Lorentz]*2, sym) + + Note, that the same can also be done using built-in TensorSymmetry methods + + >>> sym2 = TensorSymmetry.fully_symmetric(2) + >>> sym == sym2 + True + """ + def __new__(cls, *args, **kw_args): + if len(args) == 1: + base, generators = args[0] + elif len(args) == 2: + base, generators = args + else: + raise TypeError("bsgs required, either two separate parameters or one tuple") + + if not isinstance(base, Tuple): + base = Tuple(*base) + if not isinstance(generators, Tuple): + generators = Tuple(*generators) + + return Basic.__new__(cls, base, generators, **kw_args) + + @property + def base(self): + return self.args[0] + + @property + def generators(self): + return self.args[1] + + @property + def rank(self): + return self.generators[0].size - 2 + + @classmethod + def fully_symmetric(cls, rank): + """ + Returns a fully symmetric (antisymmetric if ``rank``<0) + TensorSymmetry object for ``abs(rank)`` indices. + """ + if rank > 0: + bsgs = get_symmetric_group_sgs(rank, False) + elif rank < 0: + bsgs = get_symmetric_group_sgs(-rank, True) + elif rank == 0: + bsgs = ([], [Permutation(1)]) + return TensorSymmetry(bsgs) + + @classmethod + def direct_product(cls, *args): + """ + Returns a TensorSymmetry object that is being a direct product of + fully (anti-)symmetric index permutation groups. + + Notes + ===== + + Some examples for different values of ``(*args)``: + ``(1)`` vector, equivalent to ``TensorSymmetry.fully_symmetric(1)`` + ``(2)`` tensor with 2 symmetric indices, equivalent to ``.fully_symmetric(2)`` + ``(-2)`` tensor with 2 antisymmetric indices, equivalent to ``.fully_symmetric(-2)`` + ``(2, -2)`` tensor with the first 2 indices commuting and the last 2 anticommuting + ``(1, 1, 1)`` tensor with 3 indices without any symmetry + """ + base, sgs = [], [Permutation(1)] + for arg in args: + if arg > 0: + bsgs2 = get_symmetric_group_sgs(arg, False) + elif arg < 0: + bsgs2 = get_symmetric_group_sgs(-arg, True) + else: + continue + base, sgs = bsgs_direct_product(base, sgs, *bsgs2) + + return TensorSymmetry(base, sgs) + + @classmethod + def riemann(cls): + """ + Returns a monotorem symmetry of the Riemann tensor + """ + return TensorSymmetry(riemann_bsgs) + + @classmethod + def no_symmetry(cls, rank): + """ + TensorSymmetry object for ``rank`` indices with no symmetry + """ + return TensorSymmetry([], [Permutation(rank+1)]) + + +@deprecated( + """ + The tensorsymmetry() function is deprecated. Use the TensorSymmetry + constructor instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensorsymmetry", +) +def tensorsymmetry(*args): + """ + Returns a ``TensorSymmetry`` object. This method is deprecated, use + ``TensorSymmetry.direct_product()`` or ``.riemann()`` instead. + + Explanation + =========== + + One can represent a tensor with any monoterm slot symmetry group + using a BSGS. + + ``args`` can be a BSGS + ``args[0]`` base + ``args[1]`` sgs + + Usually tensors are in (direct products of) representations + of the symmetric group; + ``args`` can be a list of lists representing the shapes of Young tableaux + + Notes + ===== + + For instance: + ``[[1]]`` vector + ``[[1]*n]`` symmetric tensor of rank ``n`` + ``[[n]]`` antisymmetric tensor of rank ``n`` + ``[[2, 2]]`` monoterm slot symmetry of the Riemann tensor + ``[[1],[1]]`` vector*vector + ``[[2],[1],[1]`` (antisymmetric tensor)*vector*vector + + Notice that with the shape ``[2, 2]`` we associate only the monoterm + symmetries of the Riemann tensor; this is an abuse of notation, + since the shape ``[2, 2]`` corresponds usually to the irreducible + representation characterized by the monoterm symmetries and by the + cyclic symmetry. + """ + from sympy.combinatorics import Permutation + + def tableau2bsgs(a): + if len(a) == 1: + # antisymmetric vector + n = a[0] + bsgs = get_symmetric_group_sgs(n, 1) + else: + if all(x == 1 for x in a): + # symmetric vector + n = len(a) + bsgs = get_symmetric_group_sgs(n) + elif a == [2, 2]: + bsgs = riemann_bsgs + else: + raise NotImplementedError + return bsgs + + if not args: + return TensorSymmetry(Tuple(), Tuple(Permutation(1))) + + if len(args) == 2 and isinstance(args[1][0], Permutation): + return TensorSymmetry(args) + base, sgs = tableau2bsgs(args[0]) + for a in args[1:]: + basex, sgsx = tableau2bsgs(a) + base, sgs = bsgs_direct_product(base, sgs, basex, sgsx) + return TensorSymmetry(Tuple(base, sgs)) + +@deprecated( + "TensorType is deprecated. Use tensor_heads() instead.", + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensortype", +) +class TensorType(Basic): + """ + Class of tensor types. Deprecated, use tensor_heads() instead. + + Parameters + ========== + + index_types : list of ``TensorIndexType`` of the tensor indices + symmetry : ``TensorSymmetry`` of the tensor + + Attributes + ========== + + ``index_types`` + ``symmetry`` + ``types`` : list of ``TensorIndexType`` without repetitions + """ + is_commutative = False + + def __new__(cls, index_types, symmetry, **kw_args): + assert symmetry.rank == len(index_types) + obj = Basic.__new__(cls, Tuple(*index_types), symmetry, **kw_args) + return obj + + @property + def index_types(self): + return self.args[0] + + @property + def symmetry(self): + return self.args[1] + + @property + def types(self): + return sorted(set(self.index_types), key=lambda x: x.name) + + def __str__(self): + return 'TensorType(%s)' % ([str(x) for x in self.index_types]) + + def __call__(self, s, comm=0): + """ + Return a TensorHead object or a list of TensorHead objects. + + Parameters + ========== + + s : name or string of names. + + comm : Commutation group. + + see ``_TensorManager.set_comm`` + """ + if isinstance(s, str): + names = [x.name for x in symbols(s, seq=True)] + else: + raise ValueError('expecting a string') + if len(names) == 1: + return TensorHead(names[0], self.index_types, self.symmetry, comm) + else: + return [TensorHead(name, self.index_types, self.symmetry, comm) for name in names] + + +@deprecated( + """ + The tensorhead() function is deprecated. Use tensor_heads() instead. + """, + deprecated_since_version="1.5", + active_deprecations_target="deprecated-tensorhead", +) +def tensorhead(name, typ, sym=None, comm=0): + """ + Function generating tensorhead(s). This method is deprecated, + use TensorHead constructor or tensor_heads() instead. + + Parameters + ========== + + name : name or sequence of names (as in ``symbols``) + + typ : index types + + sym : same as ``*args`` in ``tensorsymmetry`` + + comm : commutation group number + see ``_TensorManager.set_comm`` + """ + if sym is None: + sym = [[1] for i in range(len(typ))] + with ignore_warnings(SymPyDeprecationWarning): + sym = tensorsymmetry(*sym) + return TensorHead(name, typ, sym, comm) + + +class TensorHead(Basic): + """ + Tensor head of the tensor. + + Parameters + ========== + + name : name of the tensor + index_types : list of TensorIndexType + symmetry : TensorSymmetry of the tensor + comm : commutation group number + + Attributes + ========== + + ``name`` + ``index_types`` + ``rank`` : total number of indices + ``symmetry`` + ``comm`` : commutation group + + Notes + ===== + + Similar to ``symbols`` multiple TensorHeads can be created using + ``tensorhead(s, typ, sym=None, comm=0)`` function, where ``s`` + is the string of names and ``sym`` is the monoterm tensor symmetry + (see ``tensorsymmetry``). + + A ``TensorHead`` belongs to a commutation group, defined by a + symbol on number ``comm`` (see ``_TensorManager.set_comm``); + tensors in a commutation group have the same commutation properties; + by default ``comm`` is ``0``, the group of the commuting tensors. + + Examples + ======== + + Define a fully antisymmetric tensor of rank 2: + + >>> from sympy.tensor.tensor import TensorIndexType, TensorHead, TensorSymmetry + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> asym2 = TensorSymmetry.fully_symmetric(-2) + >>> A = TensorHead('A', [Lorentz, Lorentz], asym2) + + Examples with ndarray values, the components data assigned to the + ``TensorHead`` object are assumed to be in a fully-contravariant + representation. In case it is necessary to assign components data which + represents the values of a non-fully covariant tensor, see the other + examples. + + >>> from sympy.tensor.tensor import tensor_indices + >>> from sympy import diag + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> i0, i1 = tensor_indices('i0:2', Lorentz) + + Specify a replacement dictionary to keep track of the arrays to use for + replacements in the tensorial expression. The ``TensorIndexType`` is + associated to the metric used for contractions (in fully covariant form): + + >>> repl = {Lorentz: diag(1, -1, -1, -1)} + + Let's see some examples of working with components with the electromagnetic + tensor: + + >>> from sympy import symbols + >>> Ex, Ey, Ez, Bx, By, Bz = symbols('E_x E_y E_z B_x B_y B_z') + >>> c = symbols('c', positive=True) + + Let's define `F`, an antisymmetric tensor: + + >>> F = TensorHead('F', [Lorentz, Lorentz], asym2) + + Let's update the dictionary to contain the matrix to use in the + replacements: + + >>> repl.update({F(-i0, -i1): [ + ... [0, Ex/c, Ey/c, Ez/c], + ... [-Ex/c, 0, -Bz, By], + ... [-Ey/c, Bz, 0, -Bx], + ... [-Ez/c, -By, Bx, 0]]}) + + Now it is possible to retrieve the contravariant form of the Electromagnetic + tensor: + + >>> F(i0, i1).replace_with_arrays(repl, [i0, i1]) + [[0, -E_x/c, -E_y/c, -E_z/c], [E_x/c, 0, -B_z, B_y], [E_y/c, B_z, 0, -B_x], [E_z/c, -B_y, B_x, 0]] + + and the mixed contravariant-covariant form: + + >>> F(i0, -i1).replace_with_arrays(repl, [i0, -i1]) + [[0, E_x/c, E_y/c, E_z/c], [E_x/c, 0, B_z, -B_y], [E_y/c, -B_z, 0, B_x], [E_z/c, B_y, -B_x, 0]] + + Energy-momentum of a particle may be represented as: + + >>> from sympy import symbols + >>> P = TensorHead('P', [Lorentz], TensorSymmetry.no_symmetry(1)) + >>> E, px, py, pz = symbols('E p_x p_y p_z', positive=True) + >>> repl.update({P(i0): [E, px, py, pz]}) + + The contravariant and covariant components are, respectively: + + >>> P(i0).replace_with_arrays(repl, [i0]) + [E, p_x, p_y, p_z] + >>> P(-i0).replace_with_arrays(repl, [-i0]) + [E, -p_x, -p_y, -p_z] + + The contraction of a 1-index tensor by itself: + + >>> expr = P(i0)*P(-i0) + >>> expr.replace_with_arrays(repl, []) + E**2 - p_x**2 - p_y**2 - p_z**2 + """ + is_commutative = False + + def __new__(cls, name, index_types, symmetry=None, comm=0): + if isinstance(name, str): + name_symbol = Symbol(name) + elif isinstance(name, Symbol): + name_symbol = name + else: + raise ValueError("invalid name") + + if symmetry is None: + symmetry = TensorSymmetry.no_symmetry(len(index_types)) + else: + assert symmetry.rank == len(index_types) + + obj = Basic.__new__(cls, name_symbol, Tuple(*index_types), symmetry, sympify(comm)) + return obj + + @property + def name(self): + return self.args[0].name + + @property + def index_types(self): + return list(self.args[1]) + + @property + def symmetry(self): + return self.args[2] + + @property + def comm(self): + return TensorManager.comm_symbols2i(self.args[3]) + + @property + def rank(self): + return len(self.index_types) + + def __lt__(self, other): + return (self.name, self.index_types) < (other.name, other.index_types) + + def commutes_with(self, other): + """ + Returns ``0`` if ``self`` and ``other`` commute, ``1`` if they anticommute. + + Returns ``None`` if ``self`` and ``other`` neither commute nor anticommute. + """ + r = TensorManager.get_comm(self.comm, other.comm) + return r + + def _print(self): + return '%s(%s)' %(self.name, ','.join([str(x) for x in self.index_types])) + + def __call__(self, *indices, **kw_args): + """ + Returns a tensor with indices. + + Explanation + =========== + + There is a special behavior in case of indices denoted by ``True``, + they are considered auto-matrix indices, their slots are automatically + filled, and confer to the tensor the behavior of a matrix or vector + upon multiplication with another tensor containing auto-matrix indices + of the same ``TensorIndexType``. This means indices get summed over the + same way as in matrix multiplication. For matrix behavior, define two + auto-matrix indices, for vector behavior define just one. + + Indices can also be strings, in which case the attribute + ``index_types`` is used to convert them to proper ``TensorIndex``. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorSymmetry, TensorHead + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> a, b = tensor_indices('a,b', Lorentz) + >>> A = TensorHead('A', [Lorentz]*2, TensorSymmetry.no_symmetry(2)) + >>> t = A(a, -b) + >>> t + A(a, -b) + + """ + + updated_indices = [] + for idx, typ in zip(indices, self.index_types): + if isinstance(idx, str): + idx = idx.strip().replace(" ", "") + if idx.startswith('-'): + updated_indices.append(TensorIndex(idx[1:], typ, + is_up=False)) + else: + updated_indices.append(TensorIndex(idx, typ)) + else: + updated_indices.append(idx) + + updated_indices += indices[len(updated_indices):] + + tensor = Tensor(self, updated_indices, **kw_args) + return tensor.doit() + + # Everything below this line is deprecated + + def __pow__(self, other): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if self.data is None: + raise ValueError("No power on abstract tensors.") + from .array import tensorproduct, tensorcontraction + metrics = [_.data for _ in self.index_types] + + marray = self.data + marraydim = marray.rank() + for metric in metrics: + marray = tensorproduct(marray, metric, marray) + marray = tensorcontraction(marray, (0, marraydim), (marraydim+1, marraydim+2)) + + return marray ** (other * S.Half) + + @property + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return _tensor_data_substitution_dict[self] + + @data.setter + def data(self, data): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + _tensor_data_substitution_dict[self] = data + + @data.deleter + def data(self): + deprecate_data() + if self in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self] + + def __iter__(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return self.data.__iter__() + + def _components_data_full_destroy(self): + """ + EXPERIMENTAL: do not rely on this API method. + + Destroy components data associated to the ``TensorHead`` object, this + checks for attached components data, and destroys components data too. + """ + # do not garbage collect Kronecker tensor (it should be done by + # ``TensorIndexType`` garbage collection) + deprecate_data() + if self.name == "KD": + return + + # the data attached to a tensor must be deleted only by the TensorHead + # destructor. If the TensorHead is deleted, it means that there are no + # more instances of that tensor anywhere. + if self in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self] + + +def tensor_heads(s, index_types, symmetry=None, comm=0): + """ + Returns a sequence of TensorHeads from a string `s` + """ + if isinstance(s, str): + names = [x.name for x in symbols(s, seq=True)] + else: + raise ValueError('expecting a string') + + thlist = [TensorHead(name, index_types, symmetry, comm) for name in names] + if len(thlist) == 1: + return thlist[0] + return thlist + + +class TensExpr(Expr, ABC): + """ + Abstract base class for tensor expressions + + Notes + ===== + + A tensor expression is an expression formed by tensors; + currently the sums of tensors are distributed. + + A ``TensExpr`` can be a ``TensAdd`` or a ``TensMul``. + + ``TensMul`` objects are formed by products of component tensors, + and include a coefficient, which is a SymPy expression. + + + In the internal representation contracted indices are represented + by ``(ipos1, ipos2, icomp1, icomp2)``, where ``icomp1`` is the position + of the component tensor with contravariant index, ``ipos1`` is the + slot which the index occupies in that component tensor. + + Contracted indices are therefore nameless in the internal representation. + """ + + _op_priority = 12.0 + is_commutative = False + + def __neg__(self): + return self*S.NegativeOne + + def __abs__(self): + raise NotImplementedError + + def __add__(self, other): + return TensAdd(self, other).doit(deep=False) + + def __radd__(self, other): + return TensAdd(other, self).doit(deep=False) + + def __sub__(self, other): + return TensAdd(self, -other).doit(deep=False) + + def __rsub__(self, other): + return TensAdd(other, -self).doit(deep=False) + + def __mul__(self, other): + """ + Multiply two tensors using Einstein summation convention. + + Explanation + =========== + + If the two tensors have an index in common, one contravariant + and the other covariant, in their product the indices are summed + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensor_heads + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2 = tensor_indices('m0,m1,m2', Lorentz) + >>> g = Lorentz.metric + >>> p, q = tensor_heads('p,q', [Lorentz]) + >>> t1 = p(m0) + >>> t2 = q(-m0) + >>> t1*t2 + p(L_0)*q(-L_0) + """ + return TensMul(self, other).doit(deep=False) + + def __rmul__(self, other): + return TensMul(other, self).doit(deep=False) + + def __truediv__(self, other): + other = _sympify(other) + if isinstance(other, TensExpr): + raise ValueError('cannot divide by a tensor') + return TensMul(self, S.One/other).doit(deep=False) + + def __rtruediv__(self, other): + raise ValueError('cannot divide by a tensor') + + def __pow__(self, other): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if self.data is None: + raise ValueError("No power without ndarray data.") + from .array import tensorproduct, tensorcontraction + free = self.free + marray = self.data + mdim = marray.rank() + for metric in free: + marray = tensorcontraction( + tensorproduct( + marray, + metric[0].tensor_index_type.data, + marray), + (0, mdim), (mdim+1, mdim+2) + ) + return marray ** (other * S.Half) + + def __rpow__(self, other): + raise NotImplementedError + + @property + @abstractmethod + def nocoeff(self): + raise NotImplementedError("abstract method") + + @property + @abstractmethod + def coeff(self): + raise NotImplementedError("abstract method") + + @abstractmethod + def get_indices(self): + raise NotImplementedError("abstract method") + + @abstractmethod + def get_free_indices(self) -> list[TensorIndex]: + raise NotImplementedError("abstract method") + + @abstractmethod + def _replace_indices(self, repl: dict[TensorIndex, TensorIndex]) -> TensExpr: + raise NotImplementedError("abstract method") + + def fun_eval(self, *index_tuples): + deprecate_fun_eval() + return self.substitute_indices(*index_tuples) + + def get_matrix(self): + """ + DEPRECATED: do not use. + + Returns ndarray components data as a matrix, if components data are + available and ndarray dimension does not exceed 2. + """ + from sympy.matrices.dense import Matrix + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if 0 < self.rank <= 2: + rows = self.data.shape[0] + columns = self.data.shape[1] if self.rank == 2 else 1 + if self.rank == 2: + mat_list = [] * rows + for i in range(rows): + mat_list.append([]) + for j in range(columns): + mat_list[i].append(self[i, j]) + else: + mat_list = [None] * rows + for i in range(rows): + mat_list[i] = self[i] + return Matrix(mat_list) + else: + raise NotImplementedError( + "missing multidimensional reduction to matrix.") + + @staticmethod + def _get_indices_permutation(indices1, indices2): + return [indices1.index(i) for i in indices2] + + def _get_free_indices_set(self): + indset = set() + for arg in self.args: + if isinstance(arg, TensExpr): + indset.update(arg._get_free_indices_set()) + return indset + + def _get_dummy_indices_set(self): + indset = set() + for arg in self.args: + if isinstance(arg, TensExpr): + indset.update(arg._get_dummy_indices_set()) + return indset + + def _get_indices_set(self): + indset = set() + for arg in self.args: + if isinstance(arg, TensExpr): + indset.update(arg._get_indices_set()) + return indset + + @property + def _iterate_dummy_indices(self): + dummy_set = self._get_dummy_indices_set() + + def recursor(expr, pos): + if isinstance(expr, TensorIndex): + if expr in dummy_set: + yield (expr, pos) + elif isinstance(expr, (Tuple, TensExpr)): + for p, arg in enumerate(expr.args): + yield from recursor(arg, pos+(p,)) + + return recursor(self, ()) + + @property + def _iterate_free_indices(self): + free_set = self._get_free_indices_set() + + def recursor(expr, pos): + if isinstance(expr, TensorIndex): + if expr in free_set: + yield (expr, pos) + elif isinstance(expr, (Tuple, TensExpr)): + for p, arg in enumerate(expr.args): + yield from recursor(arg, pos+(p,)) + + return recursor(self, ()) + + @property + def _iterate_indices(self): + def recursor(expr, pos): + if isinstance(expr, TensorIndex): + yield (expr, pos) + elif isinstance(expr, (Tuple, TensExpr)): + for p, arg in enumerate(expr.args): + yield from recursor(arg, pos+(p,)) + + return recursor(self, ()) + + @staticmethod + def _contract_and_permute_with_metric(metric, array, pos, dim): + # TODO: add possibility of metric after (spinors) + from .array import tensorcontraction, tensorproduct, permutedims + + array = tensorcontraction(tensorproduct(metric, array), (1, 2+pos)) + permu = list(range(dim)) + permu[0], permu[pos] = permu[pos], permu[0] + return permutedims(array, permu) + + @staticmethod + def _match_indices_with_other_tensor(array, free_ind1, free_ind2, replacement_dict): + from .array import permutedims + + index_types1 = [i.tensor_index_type for i in free_ind1] + + # Check if variance of indices needs to be fixed: + pos2up = [] + pos2down = [] + free2remaining = free_ind2[:] + for pos1, index1 in enumerate(free_ind1): + if index1 in free2remaining: + pos2 = free2remaining.index(index1) + free2remaining[pos2] = None + continue + if -index1 in free2remaining: + pos2 = free2remaining.index(-index1) + free2remaining[pos2] = None + free_ind2[pos2] = index1 + if index1.is_up: + pos2up.append(pos2) + else: + pos2down.append(pos2) + else: + index2 = free2remaining[pos1] + if index2 is None: + raise ValueError("incompatible indices: %s and %s" % (free_ind1, free_ind2)) + free2remaining[pos1] = None + free_ind2[pos1] = index1 + if index1.is_up ^ index2.is_up: + if index1.is_up: + pos2up.append(pos1) + else: + pos2down.append(pos1) + + if len(set(free_ind1) & set(free_ind2)) < len(free_ind1): + raise ValueError("incompatible indices: %s and %s" % (free_ind1, free_ind2)) + + # Raise indices: + for pos in pos2up: + index_type_pos = index_types1[pos] + if index_type_pos not in replacement_dict: + raise ValueError("No metric provided to lower index") + metric = replacement_dict[index_type_pos] + metric_inverse = _TensorDataLazyEvaluator.inverse_matrix(metric) + array = TensExpr._contract_and_permute_with_metric(metric_inverse, array, pos, len(free_ind1)) + # Lower indices: + for pos in pos2down: + index_type_pos = index_types1[pos] + if index_type_pos not in replacement_dict: + raise ValueError("No metric provided to lower index") + metric = replacement_dict[index_type_pos] + array = TensExpr._contract_and_permute_with_metric(metric, array, pos, len(free_ind1)) + + if free_ind1: + permutation = TensExpr._get_indices_permutation(free_ind2, free_ind1) + array = permutedims(array, permutation) + + if hasattr(array, "rank") and array.rank() == 0: + array = array[()] + + return free_ind2, array + + def replace_with_arrays(self, replacement_dict, indices=None): + """ + Replace the tensorial expressions with arrays. The final array will + correspond to the N-dimensional array with indices arranged according + to ``indices``. + + Parameters + ========== + + replacement_dict + dictionary containing the replacement rules for tensors. + indices + the index order with respect to which the array is read. The + original index order will be used if no value is passed. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices + >>> from sympy.tensor.tensor import TensorHead + >>> from sympy import symbols, diag + + >>> L = TensorIndexType("L") + >>> i, j = tensor_indices("i j", L) + >>> A = TensorHead("A", [L]) + >>> A(i).replace_with_arrays({A(i): [1, 2]}, [i]) + [1, 2] + + Since 'indices' is optional, we can also call replace_with_arrays by + this way if no specific index order is needed: + + >>> A(i).replace_with_arrays({A(i): [1, 2]}) + [1, 2] + + >>> expr = A(i)*A(j) + >>> expr.replace_with_arrays({A(i): [1, 2]}) + [[1, 2], [2, 4]] + + For contractions, specify the metric of the ``TensorIndexType``, which + in this case is ``L``, in its covariant form: + + >>> expr = A(i)*A(-i) + >>> expr.replace_with_arrays({A(i): [1, 2], L: diag(1, -1)}) + -3 + + Symmetrization of an array: + + >>> H = TensorHead("H", [L, L]) + >>> a, b, c, d = symbols("a b c d") + >>> expr = H(i, j)/2 + H(j, i)/2 + >>> expr.replace_with_arrays({H(i, j): [[a, b], [c, d]]}) + [[a, b/2 + c/2], [b/2 + c/2, d]] + + Anti-symmetrization of an array: + + >>> expr = H(i, j)/2 - H(j, i)/2 + >>> repl = {H(i, j): [[a, b], [c, d]]} + >>> expr.replace_with_arrays(repl) + [[0, b/2 - c/2], [-b/2 + c/2, 0]] + + The same expression can be read as the transpose by inverting ``i`` and + ``j``: + + >>> expr.replace_with_arrays(repl, [j, i]) + [[0, -b/2 + c/2], [b/2 - c/2, 0]] + """ + from .array import Array + + indices = indices or [] + remap = {k.args[0] if k.is_up else -k.args[0]: k for k in self.get_free_indices()} + for i, index in enumerate(indices): + if isinstance(index, (Symbol, Mul)): + if index in remap: + indices[i] = remap[index] + else: + indices[i] = -remap[-index] + + replacement_dict = {tensor: Array(array) for tensor, array in replacement_dict.items()} + + # Check dimensions of replaced arrays: + for tensor, array in replacement_dict.items(): + if isinstance(tensor, TensorIndexType): + expected_shape = [tensor.dim for i in range(2)] + else: + expected_shape = [index_type.dim for index_type in tensor.index_types] + if len(expected_shape) != array.rank() or (not all(dim1 == dim2 if + dim1.is_number else True for dim1, dim2 in zip(expected_shape, + array.shape))): + raise ValueError("shapes for tensor %s expected to be %s, "\ + "replacement array shape is %s" % (tensor, expected_shape, + array.shape)) + + ret_indices, array = self._extract_data(replacement_dict) + + last_indices, array = self._match_indices_with_other_tensor(array, indices, ret_indices, replacement_dict) + return array + + def _check_add_Sum(self, expr, index_symbols): + from sympy.concrete.summations import Sum + indices = self.get_indices() + dum = self.dum + sum_indices = [ (index_symbols[i], 0, + indices[i].tensor_index_type.dim-1) for i, j in dum] + if sum_indices: + expr = Sum(expr, *sum_indices) + return expr + + def _expand_partial_derivative(self): + # simply delegate the _expand_partial_derivative() to + # its arguments to expand a possibly found PartialDerivative + return self.func(*[ + a._expand_partial_derivative() + if isinstance(a, TensExpr) else a + for a in self.args]) + + def _matches_simple(self, expr, repl_dict=None, old=False): + """ + Matches assuming there are no wild objects in self. + """ + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + if not isinstance(expr, TensExpr): + if len(self.get_free_indices()) > 0: + #self has indices, but expr does not. + return None + elif set(self.get_free_indices()) != set(expr.get_free_indices()): + #If there are no wilds and the free indices are not the same, they cannot match. + return None + + if canon_bp(self - expr) == S.Zero: + return repl_dict + else: + return None + + +class TensAdd(TensExpr, AssocOp): + """ + Sum of tensors. + + Parameters + ========== + + free_args : list of the free indices + + Attributes + ========== + + ``args`` : tuple of addends + ``rank`` : rank of the tensor + ``free_args`` : list of the free indices in sorted order + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_heads, tensor_indices + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> a, b = tensor_indices('a,b', Lorentz) + >>> p, q = tensor_heads('p,q', [Lorentz]) + >>> t = p(a) + q(a); t + p(a) + q(a) + + Examples with components data added to the tensor expression: + + >>> from sympy import symbols, diag + >>> x, y, z, t = symbols("x y z t") + >>> repl = {} + >>> repl[Lorentz] = diag(1, -1, -1, -1) + >>> repl[p(a)] = [1, 2, 3, 4] + >>> repl[q(a)] = [x, y, z, t] + + The following are: 2**2 - 3**2 - 2**2 - 7**2 ==> -58 + + >>> expr = p(a) + q(a) + >>> expr.replace_with_arrays(repl, [a]) + [x + 1, y + 2, z + 3, t + 4] + """ + + def __new__(cls, *args, **kw_args): + args = [_sympify(x) for x in args if x] + args = TensAdd._tensAdd_flatten(args) + args.sort(key=default_sort_key) + if not args: + return S.Zero + if len(args) == 1: + return args[0] + + return Basic.__new__(cls, *args, **kw_args) + + @property + def coeff(self): + return S.One + + @property + def nocoeff(self): + return self + + def get_free_indices(self) -> list[TensorIndex]: + return self.free_indices + + def _replace_indices(self, repl: dict[TensorIndex, TensorIndex]) -> TensExpr: + newargs = [arg._replace_indices(repl) if isinstance(arg, TensExpr) else arg for arg in self.args] + return self.func(*newargs) + + @memoize_property + def rank(self): + if isinstance(self.args[0], TensExpr): + return self.args[0].rank + else: + return 0 + + @memoize_property + def free_args(self): + if isinstance(self.args[0], TensExpr): + return self.args[0].free_args + else: + return [] + + @memoize_property + def free_indices(self): + if isinstance(self.args[0], TensExpr): + return self.args[0].get_free_indices() + else: + return set() + + def doit(self, **hints) -> Expr: + deep = hints.get('deep', True) + if deep: + args = [arg.doit(**hints) for arg in self.args] + else: + args = self.args # type: ignore + + # if any of the args are zero (after doit), drop them. Otherwise, _tensAdd_check will complain about non-matching indices, even though the TensAdd is correctly formed. + args = [arg for arg in args if arg != S.Zero] + + if len(args) == 0: + return S.Zero + elif len(args) == 1: + return args[0] + + # now check that all addends have the same indices: + TensAdd._tensAdd_check(args) + + # Collect terms appearing more than once, differing by their coefficients: + args = TensAdd._tensAdd_collect_terms(args) + + # collect canonicalized terms + def sort_key(t): + if not isinstance(t, TensExpr): + return [], [], [] + if hasattr(t, "_index_structure") and hasattr(t, "components"): + x = get_index_structure(t) + return t.components, x.free, x.dum + return [], [], [] + args.sort(key=sort_key) + + if not args: + return S.Zero + # it there is only a component tensor return it + if len(args) == 1: + return args[0] + + obj = self.func(*args) + return obj + + @staticmethod + def _tensAdd_flatten(args): + # flatten TensAdd, coerce terms which are not tensors to tensors + a = [] + for x in args: + if isinstance(x, (Add, TensAdd)): + a.extend(list(x.args)) + else: + a.append(x) + args = [x for x in a if x.coeff] + return args + + @staticmethod + def _tensAdd_check(args): + # check that all addends have the same free indices + + def get_indices_set(x: Expr) -> set[TensorIndex]: + if isinstance(x, TensExpr): + return set(x.get_free_indices()) + return set() + + indices0 = get_indices_set(args[0]) + list_indices = [get_indices_set(arg) for arg in args[1:]] + if not all(x == indices0 for x in list_indices): + raise ValueError('all tensors must have the same indices') + + @staticmethod + def _tensAdd_collect_terms(args): + # collect TensMul terms differing at most by their coefficient + terms_dict = defaultdict(list) + scalars = S.Zero + if isinstance(args[0], TensExpr): + free_indices = set(args[0].get_free_indices()) + else: + free_indices = set() + + for arg in args: + if not isinstance(arg, TensExpr): + if free_indices != set(): + raise ValueError("wrong valence") + scalars += arg + continue + if free_indices != set(arg.get_free_indices()): + raise ValueError("wrong valence") + # TODO: what is the part which is not a coeff? + # needs an implementation similar to .as_coeff_Mul() + terms_dict[arg.nocoeff].append(arg.coeff) + + new_args = [TensMul(Add(*coeff), t).doit(deep=False) for t, coeff in terms_dict.items() if Add(*coeff) != 0] + if isinstance(scalars, Add): + new_args = list(scalars.args) + new_args + elif scalars != 0: + new_args = [scalars] + new_args + return new_args + + def get_indices(self): + indices = [] + for arg in self.args: + indices.extend([i for i in get_indices(arg) if i not in indices]) + return indices + + + def __call__(self, *indices): + deprecate_call() + free_args = self.free_args + indices = list(indices) + if [x.tensor_index_type for x in indices] != [x.tensor_index_type for x in free_args]: + raise ValueError('incompatible types') + if indices == free_args: + return self + index_tuples = list(zip(free_args, indices)) + a = [x.func(*x.substitute_indices(*index_tuples).args) for x in self.args] + res = TensAdd(*a).doit(deep=False) + return res + + def canon_bp(self): + """ + Canonicalize using the Butler-Portugal algorithm for canonicalization + under monoterm symmetries. + """ + expr = self.expand() + if isinstance(expr, self.func): + args = [canon_bp(x) for x in expr.args] + res = TensAdd(*args).doit(deep=False) + return res + else: + return canon_bp(expr) + + def equals(self, other): + other = _sympify(other) + if isinstance(other, TensMul) and other.coeff == 0: + return all(x.coeff == 0 for x in self.args) + if isinstance(other, TensExpr): + if self.rank != other.rank: + return False + if isinstance(other, TensAdd): + if set(self.args) != set(other.args): + return False + else: + return True + t = self - other + if not isinstance(t, TensExpr): + return t == 0 + else: + if isinstance(t, TensMul): + return t.coeff == 0 + else: + return all(x.coeff == 0 for x in t.args) + + def __getitem__(self, item): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return self.data[item] + + def contract_delta(self, delta): + args = [x.contract_delta(delta) if isinstance(x, TensExpr) else x for x in self.args] + t = TensAdd(*args).doit(deep=False) + return canon_bp(t) + + def contract_metric(self, g): + """ + Raise or lower indices with the metric ``g``. + + Parameters + ========== + + g : metric + + contract_all : if True, eliminate all ``g`` which are contracted + + Notes + ===== + + see the ``TensorIndexType`` docstring for the contraction conventions + """ + + args = [contract_metric(x, g) for x in self.args] + t = TensAdd(*args).doit(deep=False) + return canon_bp(t) + + def substitute_indices(self, *index_tuples): + new_args = [] + for arg in self.args: + if isinstance(arg, TensExpr): + arg = arg.substitute_indices(*index_tuples) + new_args.append(arg) + return TensAdd(*new_args).doit(deep=False) + + def _print(self): + a = [] + args = self.args + for x in args: + a.append(str(x)) + s = ' + '.join(a) + s = s.replace('+ -', '- ') + return s + + def _extract_data(self, replacement_dict): + from sympy.tensor.array import Array, permutedims + args_indices, arrays = zip(*[ + arg._extract_data(replacement_dict) if + isinstance(arg, TensExpr) else ([], arg) for arg in self.args + ]) + arrays = [Array(i) for i in arrays] + ref_indices = args_indices[0] + for i in range(1, len(args_indices)): + indices = args_indices[i] + array = arrays[i] + permutation = TensMul._get_indices_permutation(indices, ref_indices) + arrays[i] = permutedims(array, permutation) + return ref_indices, sum(arrays, Array.zeros(*array.shape)) + + @property + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return _tensor_data_substitution_dict[self.expand()] + + @data.setter + def data(self, data): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + _tensor_data_substitution_dict[self] = data + + @data.deleter + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if self in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self] + + def __iter__(self): + deprecate_data() + if not self.data: + raise ValueError("No iteration on abstract tensors") + return self.data.flatten().__iter__() + + def _eval_rewrite_as_Indexed(self, *args, **kwargs): + return Add.fromiter(args) + + def _eval_partial_derivative(self, s): + # Evaluation like Add + list_addends = [] + for a in self.args: + if isinstance(a, TensExpr): + list_addends.append(a._eval_partial_derivative(s)) + # do not call diff if s is no symbol + elif s._diff_wrt: + list_addends.append(a._eval_derivative(s)) + + return self.func(*list_addends).doit(deep=False) + + def matches(self, expr, repl_dict=None, old=False): + expr = sympify(expr) + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + if not isinstance(expr, TensAdd): + return None + + if len(_get_wilds(self)) == 0: + return self._matches_simple(expr, repl_dict, old) + + def siftkey(arg): + wildatoms = _get_wilds(arg) + wildatom_types = sift(wildatoms, type) + if len(wildatoms) == 0: + return "nonwild" + elif WildTensor in wildatom_types.keys(): + for w in wildatom_types["WildTensor"]: + if len(w.get_indices()) == 0: + return "indexless_wildtensor" + return "wildtensor" + else: + return "otherwild" + + query_sifted = sift(self.args, siftkey) + expr_sifted = sift(expr.args, siftkey) + + #First try to match the terms without WildTensors + matched_e_tensors = [] #Used to make sure that the same tensor in expr is not matched with more than one tensor in self. + for q_tensor in query_sifted["nonwild"]: + matched_this_q = False + for e_tensor in expr_sifted["nonwild"]: + if e_tensor in matched_e_tensors: + continue + + m = q_tensor.matches(e_tensor, repl_dict=repl_dict, old=old) + if m is None: + continue + else: + matched_this_q = True + repl_dict.update(m) + matched_e_tensors.append(e_tensor) + break + + if not matched_this_q: + return None + + remaining_e_tensors = [t for t in expr_sifted["nonwild"] if t not in matched_e_tensors] + for w in query_sifted["otherwild"]: + for e in remaining_e_tensors: + m = w.matches(e) + if m is not None: + matched_e_tensors.append(e) + if w in repl_dict.keys(): + repl_dict[w] += m.pop(w) + repl_dict.update(m) + + remaining_e_tensors = [t for t in expr_sifted["nonwild"] if t not in matched_e_tensors] + for w in query_sifted["wildtensor"]: + for e in remaining_e_tensors: + m = w.matches(e) + if m is not None: + matched_e_tensors.append(e) + if w.component in repl_dict.keys(): + repl_dict[w.component] += m.pop(w.component) + repl_dict.update(m) + + remaining_e_tensors = [t for t in expr_sifted["nonwild"] if t not in matched_e_tensors] + for w in query_sifted["indexless_wildtensor"]: + for e in remaining_e_tensors: + m = w.matches(e) + if m is not None: + matched_e_tensors.append(e) + if w.component in repl_dict.keys(): + repl_dict[w.component] += m.pop(w.component) + repl_dict.update(m) + + remaining_e_tensors = [t for t in expr_sifted["nonwild"] if t not in matched_e_tensors] + if len(remaining_e_tensors) > 0: + return None + else: + return repl_dict + + +class Tensor(TensExpr): + """ + Base tensor class, i.e. this represents a tensor, the single unit to be + put into an expression. + + Explanation + =========== + + This object is usually created from a ``TensorHead``, by attaching indices + to it. Indices preceded by a minus sign are considered contravariant, + otherwise covariant. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorHead + >>> Lorentz = TensorIndexType("Lorentz", dummy_name="L") + >>> mu, nu = tensor_indices('mu nu', Lorentz) + >>> A = TensorHead("A", [Lorentz, Lorentz]) + >>> A(mu, -nu) + A(mu, -nu) + >>> A(mu, -mu) + A(L_0, -L_0) + + It is also possible to use symbols instead of inidices (appropriate indices + are then generated automatically). + + >>> from sympy import Symbol + >>> x = Symbol('x') + >>> A(x, mu) + A(x, mu) + >>> A(x, -x) + A(L_0, -L_0) + + """ + + is_commutative = False + + _index_structure: _IndexStructure + args: tuple[TensorHead, Tuple] + + def __new__(cls, tensor_head, indices, *, is_canon_bp=False, **kw_args): + indices = cls._parse_indices(tensor_head, indices) + obj = Basic.__new__(cls, tensor_head, Tuple(*indices), **kw_args) + obj._index_structure = _IndexStructure.from_indices(*indices) + obj._free = obj._index_structure.free[:] + obj._dum = obj._index_structure.dum[:] + obj._ext_rank = obj._index_structure._ext_rank + obj._coeff = S.One + obj._nocoeff = obj + obj._component = tensor_head + obj._components = [tensor_head] + if tensor_head.rank != len(indices): + raise ValueError("wrong number of indices") + obj.is_canon_bp = is_canon_bp + obj._index_map = Tensor._build_index_map(indices, obj._index_structure) + return obj + + @property + def free(self): + return self._free + + @property + def dum(self): + return self._dum + + @property + def ext_rank(self): + return self._ext_rank + + @property + def coeff(self): + return self._coeff + + @property + def nocoeff(self): + return self._nocoeff + + @property + def component(self): + return self._component + + @property + def components(self): + return self._components + + @property + def head(self): + return self.args[0] + + @property + def indices(self): + return self.args[1] + + @property + def free_indices(self): + return set(self._index_structure.get_free_indices()) + + @property + def index_types(self): + return self.head.index_types + + @property + def rank(self): + return len(self.free_indices) + + @staticmethod + def _build_index_map(indices, index_structure): + index_map = {} + for idx in indices: + index_map[idx] = (indices.index(idx),) + return index_map + + def doit(self, **hints): + args, indices, free, dum = TensMul._tensMul_contract_indices([self]) + return args[0] + + @staticmethod + def _parse_indices(tensor_head, indices): + if not isinstance(indices, (tuple, list, Tuple)): + raise TypeError("indices should be an array, got %s" % type(indices)) + indices = list(indices) + for i, index in enumerate(indices): + if isinstance(index, Symbol): + indices[i] = TensorIndex(index, tensor_head.index_types[i], True) + elif isinstance(index, Mul): + c, e = index.as_coeff_Mul() + if c == -1 and isinstance(e, Symbol): + indices[i] = TensorIndex(e, tensor_head.index_types[i], False) + else: + raise ValueError("index not understood: %s" % index) + elif not isinstance(index, TensorIndex): + raise TypeError("wrong type for index: %s is %s" % (index, type(index))) + return indices + + def _set_new_index_structure(self, im, is_canon_bp=False): + indices = im.get_indices() + return self._set_indices(*indices, is_canon_bp=is_canon_bp) + + def _set_indices(self, *indices, is_canon_bp=False, **kw_args): + if len(indices) != self.ext_rank: + raise ValueError("indices length mismatch") + return self.func(self.args[0], indices, is_canon_bp=is_canon_bp).doit() + + def _get_free_indices_set(self): + return {i[0] for i in self._index_structure.free} + + def _get_dummy_indices_set(self): + dummy_pos = set(itertools.chain(*self._index_structure.dum)) + return {idx for i, idx in enumerate(self.args[1]) if i in dummy_pos} + + def _get_indices_set(self): + return set(self.args[1].args) + + @property + def free_in_args(self): + return [(ind, pos, 0) for ind, pos in self.free] + + @property + def dum_in_args(self): + return [(p1, p2, 0, 0) for p1, p2 in self.dum] + + @property + def free_args(self): + return sorted([x[0] for x in self.free]) + + def commutes_with(self, other): + """ + :param other: + :return: + 0 commute + 1 anticommute + None neither commute nor anticommute + """ + if not isinstance(other, TensExpr): + return 0 + elif isinstance(other, Tensor): + return self.component.commutes_with(other.component) + return NotImplementedError + + def perm2tensor(self, g, is_canon_bp=False): + """ + Returns the tensor corresponding to the permutation ``g``. + + For further details, see the method in ``TIDS`` with the same name. + """ + return perm2tensor(self, g, is_canon_bp) + + def canon_bp(self): + if self.is_canon_bp: + return self + expr = self.expand() + g, dummies, msym = expr._index_structure.indices_canon_args() + v = components_canon_args([expr.component]) + can = canonicalize(g, dummies, msym, *v) + if can == 0: + return S.Zero + tensor = self.perm2tensor(can, True) + return tensor + + def split(self): + return [self] + + def sorted_components(self): + return self + + def get_indices(self) -> list[TensorIndex]: + """ + Get a list of indices, corresponding to those of the tensor. + """ + return list(self.args[1]) + + def get_free_indices(self) -> list[TensorIndex]: + """ + Get a list of free indices, corresponding to those of the tensor. + """ + return self._index_structure.get_free_indices() + + def _replace_indices(self, repl: dict[TensorIndex, TensorIndex]) -> TensExpr: + # TODO: this could be optimized by only swapping the indices + # instead of visiting the whole expression tree: + return self.xreplace(repl) + + def as_base_exp(self): + return self, S.One + + def substitute_indices(self, *index_tuples): + """ + Return a tensor with free indices substituted according to ``index_tuples``. + + ``index_types`` list of tuples ``(old_index, new_index)``. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensor_heads, TensorSymmetry + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> i, j, k, l = tensor_indices('i,j,k,l', Lorentz) + >>> A, B = tensor_heads('A,B', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + >>> t = A(i, k)*B(-k, -j); t + A(i, L_0)*B(-L_0, -j) + >>> t.substitute_indices((i, k),(-j, l)) + A(k, L_0)*B(-L_0, l) + """ + indices = [] + for index in self.indices: + for ind_old, ind_new in index_tuples: + if (index.name == ind_old.name and index.tensor_index_type == + ind_old.tensor_index_type): + if index.is_up == ind_old.is_up: + indices.append(ind_new) + else: + indices.append(-ind_new) + break + else: + indices.append(index) + return self.head(*indices) + + def _get_symmetrized_forms(self): + """ + Return a list giving all possible permutations of self that are allowed by its symmetries. + """ + comp = self.component + gens = comp.symmetry.generators + rank = comp.rank + + old_perms = None + new_perms = {self} + while new_perms != old_perms: + old_perms = new_perms.copy() + for tens in old_perms: + for gen in gens: + inds = tens.get_indices() + per = [gen.apply(i) for i in range(0,rank)] + sign = (-1)**(gen.apply(rank) - rank) + ind_map = dict(zip(inds, [inds[i] for i in per])) + new_perms.add( sign * tens._replace_indices(ind_map) ) + + return new_perms + + def matches(self, expr, repl_dict=None, old=False): + expr = sympify(expr) + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + #simple checks + if self == expr: + return repl_dict + if not isinstance(expr, Tensor): + return None + if self.head != expr.head: + return None + + #Now consider all index symmetries of expr, and see if any of them allow a match. + for new_expr in expr._get_symmetrized_forms(): + m = self._matches(new_expr, repl_dict, old=old) + if m is not None: + repl_dict.update(m) + return repl_dict + + return None + + def _matches(self, expr, repl_dict=None, old=False): + """ + This does not account for index symmetries of expr + """ + expr = sympify(expr) + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + #simple checks + if self == expr: + return repl_dict + if not isinstance(expr, Tensor): + return None + if self.head != expr.head: + return None + + s_indices = self.get_indices() + e_indices = expr.get_indices() + + if len(s_indices) != len(e_indices): + return None + + for i in range(len(s_indices)): + s_ind = s_indices[i] + m = s_ind.matches(e_indices[i]) + if m is None: + return None + elif -s_ind in repl_dict.keys() and -repl_dict[-s_ind] != m[s_ind]: + return None + else: + repl_dict.update(m) + + return repl_dict + + def __call__(self, *indices): + deprecate_call() + free_args = self.free_args + indices = list(indices) + if [x.tensor_index_type for x in indices] != [x.tensor_index_type for x in free_args]: + raise ValueError('incompatible types') + if indices == free_args: + return self + t = self.substitute_indices(*list(zip(free_args, indices))) + + # object is rebuilt in order to make sure that all contracted indices + # get recognized as dummies, but only if there are contracted indices. + if len({i if i.is_up else -i for i in indices}) != len(indices): + return t.func(*t.args) + return t + + # TODO: put this into TensExpr? + def __iter__(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return self.data.__iter__() + + # TODO: put this into TensExpr? + def __getitem__(self, item): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return self.data[item] + + def _extract_data(self, replacement_dict): + from .array import Array + for k, v in replacement_dict.items(): + if isinstance(k, Tensor) and k.args[0] == self.args[0]: + other = k + array = v + break + else: + raise ValueError("%s not found in %s" % (self, replacement_dict)) + + # TODO: inefficient, this should be done at root level only: + replacement_dict = {k: Array(v) for k, v in replacement_dict.items()} + array = Array(array) + + dum1 = self.dum + dum2 = other.dum + + if len(dum2) > 0: + for pair in dum2: + # allow `dum2` if the contained values are also in `dum1`. + if pair not in dum1: + raise NotImplementedError("%s with contractions is not implemented" % other) + # Remove elements in `dum2` from `dum1`: + dum1 = [pair for pair in dum1 if pair not in dum2] + if len(dum1) > 0: + indices1 = self.get_indices() + indices2 = other.get_indices() + repl = {} + for p1, p2 in dum1: + repl[indices2[p2]] = -indices2[p1] + for pos in (p1, p2): + if indices1[pos].is_up ^ indices2[pos].is_up: + metric = replacement_dict[indices1[pos].tensor_index_type] + if indices1[pos].is_up: + metric = _TensorDataLazyEvaluator.inverse_matrix(metric) + array = self._contract_and_permute_with_metric(metric, array, pos, len(indices2)) + other = other.xreplace(repl).doit() + array = _TensorDataLazyEvaluator.data_contract_dum([array], dum1, len(indices2)) + + free_ind1 = self.get_free_indices() + free_ind2 = other.get_free_indices() + + return self._match_indices_with_other_tensor(array, free_ind1, free_ind2, replacement_dict) + + @property + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return _tensor_data_substitution_dict[self] + + @data.setter + def data(self, data): + deprecate_data() + # TODO: check data compatibility with properties of tensor. + with ignore_warnings(SymPyDeprecationWarning): + _tensor_data_substitution_dict[self] = data + + @data.deleter + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if self in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self] + if self.metric in _tensor_data_substitution_dict: + del _tensor_data_substitution_dict[self.metric] + + def _print(self): + indices = [str(ind) for ind in self.indices] + component = self.component + if component.rank > 0: + return ('%s(%s)' % (component.name, ', '.join(indices))) + else: + return ('%s' % component.name) + + def equals(self, other): + if other == 0: + return self.coeff == 0 + other = _sympify(other) + if not isinstance(other, TensExpr): + assert not self.components + return S.One == other + + def _get_compar_comp(self): + t = self.canon_bp() + r = (t.coeff, tuple(t.components), \ + tuple(sorted(t.free)), tuple(sorted(t.dum))) + return r + + return _get_compar_comp(self) == _get_compar_comp(other) + + def contract_metric(self, g): + # if metric is not the same, ignore this step: + if self.component != g: + return self + # in case there are free components, do not perform anything: + if len(self.free) != 0: + return self + + #antisym = g.index_types[0].metric_antisym + if g.symmetry == TensorSymmetry.fully_symmetric(-2): + antisym = 1 + elif g.symmetry == TensorSymmetry.fully_symmetric(2): + antisym = 0 + elif g.symmetry == TensorSymmetry.no_symmetry(2): + antisym = None + else: + raise NotImplementedError + sign = S.One + typ = g.index_types[0] + + if not antisym: + # g(i, -i) + sign = sign*typ.dim + else: + # g(i, -i) + sign = sign*typ.dim + + dp0, dp1 = self.dum[0] + if dp0 < dp1: + # g(i, -i) = -D with antisymmetric metric + sign = -sign + + return sign + + def contract_delta(self, metric): + return self.contract_metric(metric) + + def _eval_rewrite_as_Indexed(self, tens, indices, **kwargs): + from sympy.tensor.indexed import Indexed + # TODO: replace .args[0] with .name: + index_symbols = [i.args[0] for i in self.get_indices()] + expr = Indexed(tens.args[0], *index_symbols) + return self._check_add_Sum(expr, index_symbols) + + def _eval_partial_derivative(self, s: Tensor) -> Expr: + + if not isinstance(s, Tensor): + return S.Zero + else: + + # @a_i/@a_k = delta_i^k + # @a_i/@a^k = g_ij delta^j_k + # @a^i/@a^k = delta^i_k + # @a^i/@a_k = g^ij delta_j^k + # TODO: if there is no metric present, the derivative should be zero? + + if self.head != s.head: + return S.Zero + + # if heads are the same, provide delta and/or metric products + # for every free index pair in the appropriate tensor + # assumed that the free indices are in proper order + # A contravariante index in the derivative becomes covariant + # after performing the derivative and vice versa + + kronecker_delta_list = [1] + + # not guarantee a correct index order + + for (count, (iself, iother)) in enumerate(zip(self.get_free_indices(), s.get_free_indices())): + if iself.tensor_index_type != iother.tensor_index_type: + raise ValueError("index types not compatible") + else: + tensor_index_type = iself.tensor_index_type + tensor_metric = tensor_index_type.metric + dummy = TensorIndex("d_" + str(count), tensor_index_type, + is_up=iself.is_up) + if iself.is_up == iother.is_up: + kroneckerdelta = tensor_index_type.delta(iself, -iother) + else: + kroneckerdelta = ( + TensMul(tensor_metric(iself, dummy), + tensor_index_type.delta(-dummy, -iother)) + ) + kronecker_delta_list.append(kroneckerdelta) + return TensMul.fromiter(kronecker_delta_list).doit(deep=False) + # doit necessary to rename dummy indices accordingly + + +class TensMul(TensExpr, AssocOp): + """ + Product of tensors. + + Parameters + ========== + + coeff : SymPy coefficient of the tensor + args + + Attributes + ========== + + ``components`` : list of ``TensorHead`` of the component tensors + ``types`` : list of nonrepeated ``TensorIndexType`` + ``free`` : list of ``(ind, ipos, icomp)``, see Notes + ``dum`` : list of ``(ipos1, ipos2, icomp1, icomp2)``, see Notes + ``ext_rank`` : rank of the tensor counting the dummy indices + ``rank`` : rank of the tensor + ``coeff`` : SymPy coefficient of the tensor + ``free_args`` : list of the free indices in sorted order + ``is_canon_bp`` : ``True`` if the tensor in in canonical form + + Notes + ===== + + ``args[0]`` list of ``TensorHead`` of the component tensors. + + ``args[1]`` list of ``(ind, ipos, icomp)`` + where ``ind`` is a free index, ``ipos`` is the slot position + of ``ind`` in the ``icomp``-th component tensor. + + ``args[2]`` list of tuples representing dummy indices. + ``(ipos1, ipos2, icomp1, icomp2)`` indicates that the contravariant + dummy index is the ``ipos1``-th slot position in the ``icomp1``-th + component tensor; the corresponding covariant index is + in the ``ipos2`` slot position in the ``icomp2``-th component tensor. + + """ + identity = S.One + + _index_structure: _IndexStructure + + def __new__(cls, *args, **kw_args): + is_canon_bp = kw_args.get('is_canon_bp', False) + args = list(map(_sympify, args)) + + """ + If the internal dummy indices in one arg conflict with the free indices + of the remaining args, we need to rename those internal dummy indices. + """ + free = [get_free_indices(arg) for arg in args] + free = set(itertools.chain(*free)) #flatten free + newargs = [] + for arg in args: + dum_this = set(get_dummy_indices(arg)) + dum_other = [get_dummy_indices(a) for a in newargs] + dum_other = set(itertools.chain(*dum_other)) #flatten dum_other + free_this = set(get_free_indices(arg)) + if len(dum_this.intersection(free)) > 0: + exclude = free_this.union(free, dum_other) + newarg = TensMul._dedupe_indices(arg, exclude) + else: + newarg = arg + newargs.append(newarg) + + args = newargs + + # Flatten: + args = [i for arg in args for i in (arg.args if isinstance(arg, (TensMul, Mul)) else [arg])] + + args, indices, free, dum = TensMul._tensMul_contract_indices(args, replace_indices=False) + + # Data for indices: + index_types = [i.tensor_index_type for i in indices] + index_structure = _IndexStructure(free, dum, index_types, indices, canon_bp=is_canon_bp) + + obj = TensExpr.__new__(cls, *args) + obj._indices = indices + obj._index_types = index_types.copy() + obj._index_structure = index_structure + obj._free = index_structure.free[:] + obj._dum = index_structure.dum[:] + obj._free_indices = {x[0] for x in obj.free} + obj._rank = len(obj.free) + obj._ext_rank = len(obj._index_structure.free) + 2*len(obj._index_structure.dum) + obj._coeff = S.One + obj._is_canon_bp = is_canon_bp + return obj + + index_types = property(lambda self: self._index_types) + free = property(lambda self: self._free) + dum = property(lambda self: self._dum) + free_indices = property(lambda self: self._free_indices) + rank = property(lambda self: self._rank) + ext_rank = property(lambda self: self._ext_rank) + + @staticmethod + def _indices_to_free_dum(args_indices): + free2pos1 = {} + free2pos2 = {} + dummy_data = [] + indices = [] + + # Notation for positions (to better understand the code): + # `pos1`: position in the `args`. + # `pos2`: position in the indices. + + # Example: + # A(i, j)*B(k, m, n)*C(p) + # `pos1` of `n` is 1 because it's in `B` (second `args` of TensMul). + # `pos2` of `n` is 4 because it's the fifth overall index. + + # Counter for the index position wrt the whole expression: + pos2 = 0 + + for pos1, arg_indices in enumerate(args_indices): + + for index in arg_indices: + if not isinstance(index, TensorIndex): + raise TypeError("expected TensorIndex") + if -index in free2pos1: + # Dummy index detected: + other_pos1 = free2pos1.pop(-index) + other_pos2 = free2pos2.pop(-index) + if index.is_up: + dummy_data.append((index, pos1, other_pos1, pos2, other_pos2)) + else: + dummy_data.append((-index, other_pos1, pos1, other_pos2, pos2)) + indices.append(index) + elif index in free2pos1: + raise ValueError("Repeated index: %s" % index) + else: + free2pos1[index] = pos1 + free2pos2[index] = pos2 + indices.append(index) + pos2 += 1 + + free = list(free2pos2.items()) + free_names = [i.name for i in free2pos2.keys()] + + dummy_data.sort(key=lambda x: x[3]) + return indices, free, free_names, dummy_data + + @staticmethod + def _dummy_data_to_dum(dummy_data): + return [(p2a, p2b) for (i, p1a, p1b, p2a, p2b) in dummy_data] + + @staticmethod + def _tensMul_contract_indices(args, replace_indices=True): + replacements = [{} for _ in args] + + #_index_order = all(_has_index_order(arg) for arg in args) + + args_indices = [get_indices(arg) for arg in args] + indices, free, free_names, dummy_data = TensMul._indices_to_free_dum(args_indices) + + cdt = defaultdict(int) + + def dummy_name_gen(tensor_index_type): + nd = str(cdt[tensor_index_type]) + cdt[tensor_index_type] += 1 + return tensor_index_type.dummy_name + '_' + nd + + if replace_indices: + for old_index, pos1cov, pos1contra, pos2cov, pos2contra in dummy_data: + index_type = old_index.tensor_index_type + while True: + dummy_name = dummy_name_gen(index_type) + if dummy_name not in free_names: + break + dummy = old_index.func(dummy_name, index_type, *old_index.args[2:]) + replacements[pos1cov][old_index] = dummy + replacements[pos1contra][-old_index] = -dummy + indices[pos2cov] = dummy + indices[pos2contra] = -dummy + args = [ + arg._replace_indices(repl) if isinstance(arg, TensExpr) else arg + for arg, repl in zip(args, replacements)] + + """ + The order of indices might've changed due to the replacements (e.g. if one of the args is a TensAdd, replacing an index can change the sort order of the terms, thus changing the order of indices returned by its get_indices() method). + To stay on the safe side, we calculate these quantities again. + """ + args_indices = [get_indices(arg) for arg in args] + indices, free, free_names, dummy_data = TensMul._indices_to_free_dum(args_indices) + + dum = TensMul._dummy_data_to_dum(dummy_data) + return args, indices, free, dum + + @staticmethod + def _get_components_from_args(args): + """ + Get a list of ``Tensor`` objects having the same ``TIDS`` if multiplied + by one another. + """ + components = [] + for arg in args: + if not isinstance(arg, TensExpr): + continue + if isinstance(arg, TensAdd): + continue + components.extend(arg.components) + return components + + @staticmethod + def _rebuild_tensors_list(args, index_structure): + indices = index_structure.get_indices() + #tensors = [None for i in components] # pre-allocate list + ind_pos = 0 + for i, arg in enumerate(args): + if not isinstance(arg, TensExpr): + continue + prev_pos = ind_pos + ind_pos += arg.ext_rank + args[i] = Tensor(arg.component, indices[prev_pos:ind_pos]) + + def doit(self, **hints): + is_canon_bp = self._is_canon_bp + deep = hints.get('deep', True) + if deep: + args = [arg.doit(**hints) for arg in self.args] + + """ + There may now be conflicts between dummy indices of different args + (each arg's doit method does not have any information about which + dummy indices are already used in the other args), so we + deduplicate them. + """ + rule = dict(zip(self.args, args)) + rule = self._dedupe_indices_in_rule(rule) + args = [rule[a] for a in self.args] + + else: + args = self.args + + args = [arg for arg in args if arg != self.identity] + + # Extract non-tensor coefficients: + coeff = reduce(lambda a, b: a*b, [arg for arg in args if not isinstance(arg, TensExpr)], S.One) + args = [arg for arg in args if isinstance(arg, TensExpr)] + + if len(args) == 0: + return coeff + + if coeff != self.identity: + args = [coeff] + args + if coeff == 0: + return S.Zero + + if len(args) == 1: + return args[0] + + args, indices, free, dum = TensMul._tensMul_contract_indices(args) + + # Data for indices: + index_types = [i.tensor_index_type for i in indices] + index_structure = _IndexStructure(free, dum, index_types, indices, canon_bp=is_canon_bp) + + obj = self.func(*args) + obj._index_types = index_types + obj._index_structure = index_structure + obj._ext_rank = len(obj._index_structure.free) + 2*len(obj._index_structure.dum) + obj._coeff = coeff + obj._is_canon_bp = is_canon_bp + return obj + + # TODO: this method should be private + # TODO: should this method be renamed _from_components_free_dum ? + @staticmethod + def from_data(coeff, components, free, dum, **kw_args): + return TensMul(coeff, *TensMul._get_tensors_from_components_free_dum(components, free, dum), **kw_args).doit(deep=False) + + @staticmethod + def _get_tensors_from_components_free_dum(components, free, dum): + """ + Get a list of ``Tensor`` objects by distributing ``free`` and ``dum`` indices on the ``components``. + """ + index_structure = _IndexStructure.from_components_free_dum(components, free, dum) + indices = index_structure.get_indices() + tensors = [None for i in components] # pre-allocate list + + # distribute indices on components to build a list of tensors: + ind_pos = 0 + for i, component in enumerate(components): + prev_pos = ind_pos + ind_pos += component.rank + tensors[i] = Tensor(component, indices[prev_pos:ind_pos]) + return tensors + + def _get_free_indices_set(self): + return {i[0] for i in self.free} + + def _get_dummy_indices_set(self): + dummy_pos = set(itertools.chain(*self.dum)) + return {idx for i, idx in enumerate(self._index_structure.get_indices()) if i in dummy_pos} + + def _get_position_offset_for_indices(self): + arg_offset = [None for i in range(self.ext_rank)] + counter = 0 + for arg in self.args: + if not isinstance(arg, TensExpr): + continue + for j in range(arg.ext_rank): + arg_offset[j + counter] = counter + counter += arg.ext_rank + return arg_offset + + @property + def free_args(self): + return sorted([x[0] for x in self.free]) + + @property + def components(self): + return self._get_components_from_args(self.args) + + @property + def free_in_args(self): + arg_offset = self._get_position_offset_for_indices() + argpos = self._get_indices_to_args_pos() + return [(ind, pos-arg_offset[pos], argpos[pos]) for (ind, pos) in self.free] + + @property + def coeff(self): + # return Mul.fromiter([c for c in self.args if not isinstance(c, TensExpr)]) + return self._coeff + + @property + def nocoeff(self): + return self.func(*self.args, 1/self.coeff).doit(deep=False) + + @property + def dum_in_args(self): + arg_offset = self._get_position_offset_for_indices() + argpos = self._get_indices_to_args_pos() + return [(p1-arg_offset[p1], p2-arg_offset[p2], argpos[p1], argpos[p2]) for p1, p2 in self.dum] + + def equals(self, other): + if other == 0: + return self.coeff == 0 + other = _sympify(other) + if not isinstance(other, TensExpr): + assert not self.components + return self.coeff == other + + return self.canon_bp() == other.canon_bp() + + def get_indices(self): + """ + Returns the list of indices of the tensor. + + Explanation + =========== + + The indices are listed in the order in which they appear in the + component tensors. + The dummy indices are given a name which does not collide with + the names of the free indices. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensor_heads + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2 = tensor_indices('m0,m1,m2', Lorentz) + >>> g = Lorentz.metric + >>> p, q = tensor_heads('p,q', [Lorentz]) + >>> t = p(m1)*g(m0,m2) + >>> t.get_indices() + [m1, m0, m2] + >>> t2 = p(m1)*g(-m1, m2) + >>> t2.get_indices() + [L_0, -L_0, m2] + """ + return self._indices + + def get_free_indices(self) -> list[TensorIndex]: + """ + Returns the list of free indices of the tensor. + + Explanation + =========== + + The indices are listed in the order in which they appear in the + component tensors. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensor_heads + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2 = tensor_indices('m0,m1,m2', Lorentz) + >>> g = Lorentz.metric + >>> p, q = tensor_heads('p,q', [Lorentz]) + >>> t = p(m1)*g(m0,m2) + >>> t.get_free_indices() + [m1, m0, m2] + >>> t2 = p(m1)*g(-m1, m2) + >>> t2.get_free_indices() + [m2] + """ + return self._index_structure.get_free_indices() + + def _replace_indices(self, repl: dict[TensorIndex, TensorIndex]) -> TensExpr: + return self.func(*[arg._replace_indices(repl) if isinstance(arg, TensExpr) else arg for arg in self.args]) + + def split(self): + """ + Returns a list of tensors, whose product is ``self``. + + Explanation + =========== + + Dummy indices contracted among different tensor components + become free indices with the same name as the one used to + represent the dummy indices. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensor_heads, TensorSymmetry + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> a, b, c, d = tensor_indices('a,b,c,d', Lorentz) + >>> A, B = tensor_heads('A,B', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + >>> t = A(a,b)*B(-b,c) + >>> t + A(a, L_0)*B(-L_0, c) + >>> t.split() + [A(a, L_0), B(-L_0, c)] + """ + if self.args == (): + return [self] + splitp = [] + res = 1 + for arg in self.args: + if isinstance(arg, Tensor): + splitp.append(res*arg) + res = 1 + else: + res *= arg + return splitp + + def _eval_expand_mul(self, **hints): + args1 = [arg.args if isinstance(arg, (Add, TensAdd)) else (arg,) for arg in self.args] + return TensAdd(*[ + TensMul(*i).doit(deep=False) for i in itertools.product(*args1)] + ) + + def __neg__(self): + return TensMul(S.NegativeOne, self, is_canon_bp=self._is_canon_bp).doit(deep=False) + + def __getitem__(self, item): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + return self.data[item] + + def _get_args_for_traditional_printer(self): + args = list(self.args) + if self.coeff.could_extract_minus_sign(): + # expressions like "-A(a)" + sign = "-" + if args[0] == S.NegativeOne: + args = args[1:] + else: + args[0] = -args[0] + else: + sign = "" + return sign, args + + def _sort_args_for_sorted_components(self): + """ + Returns the ``args`` sorted according to the components commutation + properties. + + Explanation + =========== + + The sorting is done taking into account the commutation group + of the component tensors. + """ + cv = [arg for arg in self.args if isinstance(arg, TensExpr)] + sign = 1 + n = len(cv) - 1 + for i in range(n): + for j in range(n, i, -1): + c = cv[j-1].commutes_with(cv[j]) + # if `c` is `None`, it does neither commute nor anticommute, skip: + if c not in (0, 1): + continue + typ1 = sorted(set(cv[j-1].component.index_types), key=lambda x: x.name) + typ2 = sorted(set(cv[j].component.index_types), key=lambda x: x.name) + if (typ1, cv[j-1].component.name) > (typ2, cv[j].component.name): + cv[j-1], cv[j] = cv[j], cv[j-1] + # if `c` is 1, the anticommute, so change sign: + if c: + sign = -sign + + coeff = sign * self.coeff + if coeff != 1: + return [coeff] + cv + return cv + + def sorted_components(self): + """ + Returns a tensor product with sorted components. + """ + return TensMul(*self._sort_args_for_sorted_components()).doit(deep=False) + + def perm2tensor(self, g, is_canon_bp=False): + """ + Returns the tensor corresponding to the permutation ``g`` + + For further details, see the method in ``TIDS`` with the same name. + """ + return perm2tensor(self, g, is_canon_bp=is_canon_bp) + + def canon_bp(self): + """ + Canonicalize using the Butler-Portugal algorithm for canonicalization + under monoterm symmetries. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorHead, TensorSymmetry + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2 = tensor_indices('m0,m1,m2', Lorentz) + >>> A = TensorHead('A', [Lorentz]*2, TensorSymmetry.fully_symmetric(-2)) + >>> t = A(m0,-m1)*A(m1,-m0) + >>> t.canon_bp() + -A(L_0, L_1)*A(-L_0, -L_1) + >>> t = A(m0,-m1)*A(m1,-m2)*A(m2,-m0) + >>> t.canon_bp() + 0 + """ + if self._is_canon_bp: + return self + expr = self.expand() + if isinstance(expr, TensAdd): + return expr.canon_bp() + if not expr.components: + return expr + expr = expr.doit(deep=False) #make sure self.coeff is populated correctly + t = expr.sorted_components() + g, dummies, msym = t._index_structure.indices_canon_args() + v = components_canon_args(t.components) + can = canonicalize(g, dummies, msym, *v) + if can == 0: + return S.Zero + tmul = t.perm2tensor(can, True) + return tmul + + def contract_delta(self, delta): + t = self.contract_metric(delta) + return t + + def _get_indices_to_args_pos(self): + """ + Get a dict mapping the index position to TensMul's argument number. + """ + pos_map = {} + pos_counter = 0 + for arg_i, arg in enumerate(self.args): + if not isinstance(arg, TensExpr): + continue + assert isinstance(arg, Tensor) + for i in range(arg.ext_rank): + pos_map[pos_counter] = arg_i + pos_counter += 1 + return pos_map + + def contract_metric(self, g): + """ + Raise or lower indices with the metric ``g``. + + Parameters + ========== + + g : metric + + Notes + ===== + + See the ``TensorIndexType`` docstring for the contraction conventions. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensor_heads + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> m0, m1, m2 = tensor_indices('m0,m1,m2', Lorentz) + >>> g = Lorentz.metric + >>> p, q = tensor_heads('p,q', [Lorentz]) + >>> t = p(m0)*q(m1)*g(-m0, -m1) + >>> t.canon_bp() + metric(L_0, L_1)*p(-L_0)*q(-L_1) + >>> t.contract_metric(g).canon_bp() + p(L_0)*q(-L_0) + """ + expr = self.expand().doit(deep=False) + if self != expr: + expr = canon_bp(expr) + return contract_metric(expr, g) + pos_map = self._get_indices_to_args_pos() + args = list(self.args) + + #antisym = g.index_types[0].metric_antisym + if g.symmetry == TensorSymmetry.fully_symmetric(-2): + antisym = 1 + elif g.symmetry == TensorSymmetry.fully_symmetric(2): + antisym = 0 + elif g.symmetry == TensorSymmetry.no_symmetry(2): + antisym = None + else: + raise NotImplementedError + + # list of positions of the metric ``g`` inside ``args`` + gpos = [i for i, x in enumerate(self.args) if isinstance(x, Tensor) and x.component == g] + if not gpos: + return self + + # Sign is either 1 or -1, to correct the sign after metric contraction + # (for spinor indices). + sign = 1 + dum = self.dum[:] + free = self.free[:] + elim = set() + for gposx in gpos: + if gposx in elim: + continue + free1 = [x for x in free if pos_map[x[1]] == gposx] + dum1 = [x for x in dum if pos_map[x[0]] == gposx or pos_map[x[1]] == gposx] + if not dum1: + continue + elim.add(gposx) + # subs with the multiplication neutral element, that is, remove it: + args[gposx] = 1 + if len(dum1) == 2: + if not antisym: + dum10, dum11 = dum1 + if pos_map[dum10[1]] == gposx: + # the index with pos p0 contravariant + p0 = dum10[0] + else: + # the index with pos p0 is covariant + p0 = dum10[1] + if pos_map[dum11[1]] == gposx: + # the index with pos p1 is contravariant + p1 = dum11[0] + else: + # the index with pos p1 is covariant + p1 = dum11[1] + + dum.append((p0, p1)) + else: + dum10, dum11 = dum1 + # change the sign to bring the indices of the metric to contravariant + # form; change the sign if dum10 has the metric index in position 0 + if pos_map[dum10[1]] == gposx: + # the index with pos p0 is contravariant + p0 = dum10[0] + if dum10[1] == 1: + sign = -sign + else: + # the index with pos p0 is covariant + p0 = dum10[1] + if dum10[0] == 0: + sign = -sign + if pos_map[dum11[1]] == gposx: + # the index with pos p1 is contravariant + p1 = dum11[0] + sign = -sign + else: + # the index with pos p1 is covariant + p1 = dum11[1] + + dum.append((p0, p1)) + + elif len(dum1) == 1: + if not antisym: + dp0, dp1 = dum1[0] + if pos_map[dp0] == pos_map[dp1]: + # g(i, -i) + typ = g.index_types[0] + sign = sign*typ.dim + + else: + # g(i0, i1)*p(-i1) + if pos_map[dp0] == gposx: + p1 = dp1 + else: + p1 = dp0 + + ind, p = free1[0] + free.append((ind, p1)) + else: + dp0, dp1 = dum1[0] + if pos_map[dp0] == pos_map[dp1]: + # g(i, -i) + typ = g.index_types[0] + sign = sign*typ.dim + + if dp0 < dp1: + # g(i, -i) = -D with antisymmetric metric + sign = -sign + else: + # g(i0, i1)*p(-i1) + if pos_map[dp0] == gposx: + p1 = dp1 + if dp0 == 0: + sign = -sign + else: + p1 = dp0 + ind, p = free1[0] + free.append((ind, p1)) + dum = [x for x in dum if x not in dum1] + free = [x for x in free if x not in free1] + + # shift positions: + shift = 0 + shifts = [0]*len(args) + for i in range(len(args)): + if i in elim: + shift += 2 + continue + shifts[i] = shift + free = [(ind, p - shifts[pos_map[p]]) for (ind, p) in free if pos_map[p] not in elim] + dum = [(p0 - shifts[pos_map[p0]], p1 - shifts[pos_map[p1]]) for p0, p1 in dum if pos_map[p0] not in elim and pos_map[p1] not in elim] + + res = ( sign*TensMul(*args) ).doit(deep=False) + if not isinstance(res, TensExpr): + return res + im = _IndexStructure.from_components_free_dum(res.components, free, dum) + return res._set_new_index_structure(im) + + def _set_new_index_structure(self, im, is_canon_bp=False): + indices = im.get_indices() + return self._set_indices(*indices, is_canon_bp=is_canon_bp) + + def _set_indices(self, *indices, is_canon_bp=False, **kw_args): + if len(indices) != self.ext_rank: + raise ValueError("indices length mismatch") + args = list(self.args) + pos = 0 + for i, arg in enumerate(args): + if not isinstance(arg, TensExpr): + continue + assert isinstance(arg, Tensor) + ext_rank = arg.ext_rank + args[i] = arg._set_indices(*indices[pos:pos+ext_rank]) + pos += ext_rank + return TensMul(*args, is_canon_bp=is_canon_bp).doit(deep=False) + + @staticmethod + def _index_replacement_for_contract_metric(args, free, dum): + for arg in args: + if not isinstance(arg, TensExpr): + continue + assert isinstance(arg, Tensor) + + def substitute_indices(self, *index_tuples): + new_args = [] + for arg in self.args: + if isinstance(arg, TensExpr): + arg = arg.substitute_indices(*index_tuples) + new_args.append(arg) + return TensMul(*new_args).doit(deep=False) + + def __call__(self, *indices): + deprecate_call() + free_args = self.free_args + indices = list(indices) + if [x.tensor_index_type for x in indices] != [x.tensor_index_type for x in free_args]: + raise ValueError('incompatible types') + if indices == free_args: + return self + t = self.substitute_indices(*list(zip(free_args, indices))) + + # object is rebuilt in order to make sure that all contracted indices + # get recognized as dummies, but only if there are contracted indices. + if len({i if i.is_up else -i for i in indices}) != len(indices): + return t.func(*t.args) + return t + + def _extract_data(self, replacement_dict): + args_indices, arrays = zip(*[arg._extract_data(replacement_dict) for arg in self.args if isinstance(arg, TensExpr)]) + coeff = reduce(operator.mul, [a for a in self.args if not isinstance(a, TensExpr)], S.One) + indices, free, free_names, dummy_data = TensMul._indices_to_free_dum(args_indices) + dum = TensMul._dummy_data_to_dum(dummy_data) + ext_rank = self.ext_rank + free.sort(key=lambda x: x[1]) + free_indices = [i[0] for i in free] + return free_indices, coeff*_TensorDataLazyEvaluator.data_contract_dum(arrays, dum, ext_rank) + + @property + def data(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + dat = _tensor_data_substitution_dict[self.expand()] + return dat + + @data.setter + def data(self, data): + deprecate_data() + raise ValueError("Not possible to set component data to a tensor expression") + + @data.deleter + def data(self): + deprecate_data() + raise ValueError("Not possible to delete component data to a tensor expression") + + def __iter__(self): + deprecate_data() + with ignore_warnings(SymPyDeprecationWarning): + if self.data is None: + raise ValueError("No iteration on abstract tensors") + return self.data.__iter__() + + @staticmethod + def _dedupe_indices(new, exclude): + """ + exclude: set + new: TensExpr + + If ``new`` has any dummy indices that are in ``exclude``, return a version + of new with those indices replaced. If no replacements are needed, + return None + + """ + exclude = set(exclude) + dums_new = set(get_dummy_indices(new)) + free_new = set(get_free_indices(new)) + + conflicts = dums_new.intersection(exclude) + if len(conflicts) == 0: + return None + + """ + ``exclude_for_gen`` is to be passed to ``_IndexStructure._get_generator_for_dummy_indices()``. + Since the latter does not use the index position for anything, we just + set it as ``None`` here. + """ + exclude.update(dums_new) + exclude.update(free_new) + exclude_for_gen = [(i, None) for i in exclude] + gen = _IndexStructure._get_generator_for_dummy_indices(exclude_for_gen) + repl = {} + for d in conflicts: + if -d in repl.keys(): + continue + newname = gen(d.tensor_index_type) + new_d = d.func(newname, *d.args[1:]) + repl[d] = new_d + repl[-d] = -new_d + + if len(repl) == 0: + return None + + new_renamed = new._replace_indices(repl) + return new_renamed + + def _dedupe_indices_in_rule(self, rule): + """ + rule: dict + + This applies TensMul._dedupe_indices on all values of rule. + + """ + index_rules = {k:v for k,v in rule.items() if isinstance(k, TensorIndex)} + other_rules = {k:v for k,v in rule.items() if k not in index_rules.keys()} + exclude = set(self.get_indices()) + + newrule = {} + newrule.update(index_rules) + exclude.update(index_rules.keys()) + exclude.update(index_rules.values()) + for old, new in other_rules.items(): + new_renamed = TensMul._dedupe_indices(new, exclude) + if old == new or new_renamed is None: + newrule[old] = new + else: + newrule[old] = new_renamed + exclude.update(get_indices(new_renamed)) + return newrule + + def _eval_subs(self, old, new): + """ + If new is an index which is already present in self as a dummy, the dummies in self should be renamed. + """ + + if not isinstance(new, TensorIndex): + return None + + exclude = {new} + self_renamed = self._dedupe_indices(self, exclude) + if self_renamed is None: + return None + else: + return self_renamed._subs(old, new).doit(deep=False) + + def _eval_rewrite_as_Indexed(self, *args, **kwargs): + from sympy.concrete.summations import Sum + index_symbols = [i.args[0] for i in self.get_indices()] + args = [arg.args[0] if isinstance(arg, Sum) else arg for arg in args] + expr = Mul.fromiter(args) + return self._check_add_Sum(expr, index_symbols) + + def _eval_partial_derivative(self, s): + # Evaluation like Mul + terms = [] + for i, arg in enumerate(self.args): + # checking whether some tensor instance is differentiated + # or some other thing is necessary, but ugly + if isinstance(arg, TensExpr): + d = arg._eval_partial_derivative(s) + else: + # do not call diff is s is no symbol + if s._diff_wrt: + d = arg._eval_derivative(s) + else: + d = S.Zero + if d: + terms.append(TensMul.fromiter(self.args[:i] + (d,) + self.args[i + 1:]).doit(deep=False)) + return TensAdd.fromiter(terms).doit(deep=False) + + + def _matches_commutative(self, expr, repl_dict=None, old=False): + """ + Match assuming all tensors commute. But note that we are not assuming anything about their symmetry under index permutations. + """ + #Take care of the various possible types for expr. + if not isinstance(expr, TensMul): + if isinstance(expr, (TensExpr, Expr)): + expr = TensMul(expr) + else: + return None + + #The code that follows assumes expr is a TensMul + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + #Make sure that none of the dummy indices in self, expr conflict with the values already present in repl_dict. This may happen due to automatic index relabelling when rem_query and rem_expr are formed later on in this function (it calls itself recursively). + indices = [k for k in repl_dict.values() if isinstance(k ,TensorIndex)] + + def dedupe(expr): + renamed = TensMul._dedupe_indices(expr, indices) + if renamed is not None: + return renamed + else: + return expr + + self = dedupe(self) + expr = dedupe(expr) + + #Find the non-tensor part of expr. This need not be the same as expr.coeff when expr.doit() has not been called. + expr_coeff = reduce(lambda a, b: a*b, [arg for arg in expr.args if not isinstance(arg, TensExpr)], S.One) + + # handle simple patterns + if self == expr: + return repl_dict + + if len(_get_wilds(self)) == 0: + return self._matches_simple(expr, repl_dict, old) + + def siftkey(arg): + if isinstance(arg, WildTensor): + return "WildTensor" + elif isinstance(arg, (Tensor, TensExpr)): + return "Tensor" + else: + return "coeff" + + query_sifted = sift(self.args, siftkey) + expr_sifted = sift(expr.args, siftkey) + + #Sanity checks + if "coeff" in query_sifted.keys(): + if TensMul(*query_sifted["coeff"]).doit(deep=False) != self.coeff: + raise NotImplementedError(f"Found something that we do not know to handle: {query_sifted['coeff']}") + if "coeff" in expr_sifted.keys(): + if TensMul(*expr_sifted["coeff"]).doit(deep=False) != expr_coeff: + raise NotImplementedError(f"Found something that we do not know to handle: {expr_sifted['coeff']}") + + query_tens_heads = {tuple(getattr(x, "components", [])) for x in query_sifted["Tensor"]} #We use getattr because, e.g. TensAdd does not have the 'components' attribute. + expr_tens_heads = {tuple(getattr(x, "components", [])) for x in expr_sifted["Tensor"]} + if not query_tens_heads.issubset(expr_tens_heads): + #Some tensorheads in self are not present in the expr + return None + + #Try to match all non-wild tensors of self with tensors that compose expr + if len(query_sifted["Tensor"]) > 0: + q_tensor = query_sifted["Tensor"][0] + """ + We need to iterate over all possible symmetrized forms of q_tensor since the matches given by some of them may map dummy indices to free indices; the information about which indices are dummy/free will only be available later, when we are doing rem_q.matches(rem_e) + """ + for q_tens in q_tensor._get_symmetrized_forms(): + for e in expr_sifted["Tensor"]: + if isinstance(q_tens, TensMul): + #q_tensor got a minus sign due to this permutation. + sign = -1 + else: + sign = 1 + + """ + _matches is used here since we are already iterating over index permutations of q_tensor. Also note that the sign is removed from q_tensor, and will later be put into rem_q. + """ + m = (sign*q_tens)._matches(e) + if m is None: + continue + + rem_query = self.func(sign, *[a for a in self.args if a != q_tensor]).doit(deep=False) + rem_expr = expr.func(*[a for a in expr.args if a != e]).doit(deep=False) + tmp_repl = {} + tmp_repl.update(repl_dict) + tmp_repl.update(m) + rem_m = rem_query.matches(rem_expr, repl_dict=tmp_repl) + if rem_m is not None: + #Check that contracted indices are not mapped to different indices. + internally_consistent = True + for k in rem_m.keys(): + if isinstance(k,TensorIndex): + if -k in rem_m.keys() and rem_m[-k] != -rem_m[k]: + internally_consistent = False + break + if internally_consistent: + repl_dict.update(rem_m) + return repl_dict + + return None + + #Try to match WildTensor instances which have indices + matched_e_tensors = [] + remaining_e_tensors = expr_sifted["Tensor"] + indexless_wilds, wilds = sift(query_sifted["WildTensor"], lambda x: len(x.get_free_indices()) == 0, binary=True) + + for w in wilds: + free_this_wild = set(w.get_free_indices()) + tensors_to_try = [] + for t in remaining_e_tensors: + free = t.get_free_indices() + shares_indices_with_wild = True + for i in free: + if all(j.matches(i) is None for j in free_this_wild): + #The index i matches none of the indices in free_this_wild + shares_indices_with_wild = False + if shares_indices_with_wild: + tensors_to_try.append(t) + + m = w.matches(TensMul(*tensors_to_try).doit(deep=False) ) + if m is None: + return None + else: + for tens in tensors_to_try: + matched_e_tensors.append(tens) + repl_dict.update(m) + + #Try to match indexless WildTensor instances + remaining_e_tensors = [t for t in expr_sifted["Tensor"] if t not in matched_e_tensors] + if len(indexless_wilds) > 0: + #If there are any remaining tensors, match them with the indexless WildTensor + m = indexless_wilds[0].matches( TensMul(1,*remaining_e_tensors).doit(deep=False) ) + if m is None: + return None + else: + repl_dict.update(m) + elif len(remaining_e_tensors) > 0: + return None + + #Try to match the non-tensorial coefficient + m = self.coeff.matches(expr_coeff, old=old) + if m is None: + return None + else: + repl_dict.update(m) + + return repl_dict + + def matches(self, expr, repl_dict=None, old=False): + expr = sympify(expr) + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + commute = all(arg.component.comm == 0 for arg in expr.args if isinstance(arg, Tensor)) + if commute: + return self._matches_commutative(expr, repl_dict, old) + else: + raise NotImplementedError("Tensor matching not implemented for non-commuting tensors") + +class TensorElement(TensExpr): + """ + Tensor with evaluated components. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, TensorHead, TensorSymmetry + >>> from sympy import symbols + >>> L = TensorIndexType("L") + >>> i, j, k = symbols("i j k") + >>> A = TensorHead("A", [L, L], TensorSymmetry.fully_symmetric(2)) + >>> A(i, j).get_free_indices() + [i, j] + + If we want to set component ``i`` to a specific value, use the + ``TensorElement`` class: + + >>> from sympy.tensor.tensor import TensorElement + >>> te = TensorElement(A(i, j), {i: 2}) + + As index ``i`` has been accessed (``{i: 2}`` is the evaluation of its 3rd + element), the free indices will only contain ``j``: + + >>> te.get_free_indices() + [j] + """ + + def __new__(cls, expr, index_map): + if not isinstance(expr, Tensor): + # remap + if not isinstance(expr, TensExpr): + raise TypeError("%s is not a tensor expression" % expr) + return expr.func(*[TensorElement(arg, index_map) for arg in expr.args]) + expr_free_indices = expr.get_free_indices() + name_translation = {i.args[0]: i for i in expr_free_indices} + index_map = {name_translation.get(index, index): value for index, value in index_map.items()} + index_map = {index: value for index, value in index_map.items() if index in expr_free_indices} + if len(index_map) == 0: + return expr + free_indices = [i for i in expr_free_indices if i not in index_map.keys()] + index_map = Dict(index_map) + obj = TensExpr.__new__(cls, expr, index_map) + obj._free_indices = free_indices + return obj + + @property + def free(self): + return [(index, i) for i, index in enumerate(self.get_free_indices())] + + @property + def dum(self): + # TODO: inherit dummies from expr + return [] + + @property + def expr(self): + return self._args[0] + + @property + def index_map(self): + return self._args[1] + + @property + def coeff(self): + return S.One + + @property + def nocoeff(self): + return self + + def get_free_indices(self): + return self._free_indices + + def _replace_indices(self, repl: dict[TensorIndex, TensorIndex]) -> TensExpr: + # TODO: can be improved: + return self.xreplace(repl) + + def get_indices(self): + return self.get_free_indices() + + def _extract_data(self, replacement_dict): + ret_indices, array = self.expr._extract_data(replacement_dict) + index_map = self.index_map + slice_tuple = tuple(index_map.get(i, slice(None)) for i in ret_indices) + ret_indices = [i for i in ret_indices if i not in index_map] + array = array.__getitem__(slice_tuple) + return ret_indices, array + + +class WildTensorHead(TensorHead): + """ + A wild object that is used to create ``WildTensor`` instances + + Explanation + =========== + + Examples + ======== + >>> from sympy.tensor.tensor import TensorHead, TensorIndex, WildTensorHead, TensorIndexType + >>> R3 = TensorIndexType('R3', dim=3) + >>> p = TensorIndex('p', R3) + >>> q = TensorIndex('q', R3) + + A WildTensorHead can be created without specifying a ``TensorIndexType`` + + >>> W = WildTensorHead("W") + + Calling it with a ``TensorIndex`` creates a ``WildTensor`` instance. + + >>> type(W(p)) + + + The ``TensorIndexType`` is automatically detected from the index that is passed + + >>> W(p).component + W(R3) + + Calling it with no indices returns an object that can match tensors with any number of indices. + + >>> K = TensorHead('K', [R3]) + >>> Q = TensorHead('Q', [R3, R3]) + >>> W().matches(K(p)) + {W: K(p)} + >>> W().matches(Q(p,q)) + {W: Q(p, q)} + + If you want to ignore the order of indices while matching, pass ``unordered_indices=True``. + + >>> U = WildTensorHead("U", unordered_indices=True) + >>> W(p,q).matches(Q(q,p)) + >>> U(p,q).matches(Q(q,p)) + {U(R3,R3): _WildTensExpr(Q(q, p))} + + Parameters + ========== + name : name of the tensor + unordered_indices : whether the order of the indices matters for matching + (default: False) + + See also + ======== + ``WildTensor`` + ``TensorHead`` + + """ + def __new__(cls, name, index_types=None, symmetry=None, comm=0, unordered_indices=False): + if isinstance(name, str): + name_symbol = Symbol(name) + elif isinstance(name, Symbol): + name_symbol = name + else: + raise ValueError("invalid name") + + if index_types is None: + index_types = [] + + if symmetry is None: + symmetry = TensorSymmetry.no_symmetry(len(index_types)) + else: + assert symmetry.rank == len(index_types) + + if symmetry != TensorSymmetry.no_symmetry(len(index_types)): + raise NotImplementedError("Wild matching based on symmetry is not implemented.") + + obj = Basic.__new__(cls, name_symbol, Tuple(*index_types), sympify(symmetry), sympify(comm), sympify(unordered_indices)) + + return obj + + @property + def unordered_indices(self): + return self.args[4] + + def __call__(self, *indices, **kwargs): + tensor = WildTensor(self, indices, **kwargs) + return tensor.doit() + + +class WildTensor(Tensor): + """ + A wild object which matches ``Tensor`` instances + + Explanation + =========== + This is instantiated by attaching indices to a ``WildTensorHead`` instance. + + Examples + ======== + >>> from sympy.tensor.tensor import TensorHead, TensorIndex, WildTensorHead, TensorIndexType + >>> W = WildTensorHead("W") + >>> R3 = TensorIndexType('R3', dim=3) + >>> p = TensorIndex('p', R3) + >>> q = TensorIndex('q', R3) + >>> K = TensorHead('K', [R3]) + >>> Q = TensorHead('Q', [R3, R3]) + + Matching also takes the indices into account + >>> W(p).matches(K(p)) + {W(R3): _WildTensExpr(K(p))} + >>> W(p).matches(K(q)) + >>> W(p).matches(K(-p)) + + If you want to match objects with any number of indices, just use a ``WildTensor`` with no indices. + >>> W().matches(K(p)) + {W: K(p)} + >>> W().matches(Q(p,q)) + {W: Q(p, q)} + + See Also + ======== + ``WildTensorHead`` + ``Tensor`` + + """ + def __new__(cls, tensor_head, indices, **kw_args): + is_canon_bp = kw_args.pop("is_canon_bp", False) + + if tensor_head.func == TensorHead: + """ + If someone tried to call WildTensor by supplying a TensorHead (not a WildTensorHead), return a normal tensor instead. This is helpful when using subs on an expression to replace occurrences of a WildTensorHead with a TensorHead. + """ + return Tensor(tensor_head, indices, is_canon_bp=is_canon_bp, **kw_args) + elif tensor_head.func == _WildTensExpr: + return tensor_head(*indices) + + indices = cls._parse_indices(tensor_head, indices) + index_types = [ind.tensor_index_type for ind in indices] + tensor_head = tensor_head.func( + tensor_head.name, + index_types, + symmetry=None, + comm=tensor_head.comm, + unordered_indices=tensor_head.unordered_indices, + ) + + obj = Basic.__new__(cls, tensor_head, Tuple(*indices)) + obj.name = tensor_head.name + obj._index_structure = _IndexStructure.from_indices(*indices) + obj._free = obj._index_structure.free[:] + obj._dum = obj._index_structure.dum[:] + obj._ext_rank = obj._index_structure._ext_rank + obj._coeff = S.One + obj._nocoeff = obj + obj._component = tensor_head + obj._components = [tensor_head] + if tensor_head.rank != len(indices): + raise ValueError("wrong number of indices") + obj.is_canon_bp = is_canon_bp + obj._index_map = obj._build_index_map(indices, obj._index_structure) + + return obj + + + def matches(self, expr, repl_dict=None, old=False): + if not isinstance(expr, TensExpr) and expr != S(1): + return None + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + if len(self.indices) > 0: + if not hasattr(expr, "get_free_indices"): + return None + expr_indices = expr.get_free_indices() + if len(expr_indices) != len(self.indices): + return None + if self._component.unordered_indices: + m = self._match_indices_ignoring_order(expr) + if m is None: + return None + else: + repl_dict.update(m) + else: + for i in range(len(expr_indices)): + m = self.indices[i].matches(expr_indices[i]) + if m is None: + return None + else: + repl_dict.update(m) + + repl_dict[self.component] = _WildTensExpr(expr) + else: + #If no indices were passed to the WildTensor, it may match tensors with any number of indices. + repl_dict[self] = expr + + return repl_dict + + def _match_indices_ignoring_order(self, expr, repl_dict=None, old=False): + """ + Helper method for matches. Checks if the indices of self and expr + match disregarding index ordering. + """ + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + def siftkey(ind): + if isinstance(ind, WildTensorIndex): + if ind.ignore_updown: + return "wild, updown" + else: + return "wild" + else: + return "nonwild" + + indices_sifted = sift(self.indices, siftkey) + + matched_indices = [] + expr_indices_remaining = expr.get_indices() + for ind in indices_sifted["nonwild"]: + matched_this_ind = False + for e_ind in expr_indices_remaining: + if e_ind in matched_indices: + continue + m = ind.matches(e_ind) + if m is not None: + matched_this_ind = True + repl_dict.update(m) + matched_indices.append(e_ind) + break + if not matched_this_ind: + return None + + expr_indices_remaining = [i for i in expr_indices_remaining if i not in matched_indices] + for ind in indices_sifted["wild"]: + matched_this_ind = False + for e_ind in expr_indices_remaining: + m = ind.matches(e_ind) + if m is not None: + if -ind in repl_dict.keys() and -repl_dict[-ind] != m[ind]: + return None + matched_this_ind = True + repl_dict.update(m) + matched_indices.append(e_ind) + break + if not matched_this_ind: + return None + + expr_indices_remaining = [i for i in expr_indices_remaining if i not in matched_indices] + for ind in indices_sifted["wild, updown"]: + matched_this_ind = False + for e_ind in expr_indices_remaining: + m = ind.matches(e_ind) + if m is not None: + if -ind in repl_dict.keys() and -repl_dict[-ind] != m[ind]: + return None + matched_this_ind = True + repl_dict.update(m) + matched_indices.append(e_ind) + break + if not matched_this_ind: + return None + + if len(matched_indices) < len(self.indices): + return None + else: + return repl_dict + +class WildTensorIndex(TensorIndex): + """ + A wild object that matches TensorIndex instances. + + Examples + ======== + >>> from sympy.tensor.tensor import TensorIndex, TensorIndexType, WildTensorIndex + >>> R3 = TensorIndexType('R3', dim=3) + >>> p = TensorIndex("p", R3) + + By default, covariant indices only match with covariant indices (and + similarly for contravariant) + + >>> q = WildTensorIndex("q", R3) + >>> (q).matches(p) + {q: p} + >>> (q).matches(-p) + + If you want matching to ignore whether the index is co/contra-variant, set + ignore_updown=True + + >>> r = WildTensorIndex("r", R3, ignore_updown=True) + >>> (r).matches(-p) + {r: -p} + >>> (r).matches(p) + {r: p} + + Parameters + ========== + name : name of the index (string), or ``True`` if you want it to be + automatically assigned + tensor_index_type : ``TensorIndexType`` of the index + is_up : flag for contravariant index (is_up=True by default) + ignore_updown : bool, Whether this should match both co- and contra-variant + indices (default:False) + """ + def __new__(cls, name, tensor_index_type, is_up=True, ignore_updown=False): + if isinstance(name, str): + name_symbol = Symbol(name) + elif isinstance(name, Symbol): + name_symbol = name + elif name is True: + name = "_i{}".format(len(tensor_index_type._autogenerated)) + name_symbol = Symbol(name) + tensor_index_type._autogenerated.append(name_symbol) + else: + raise ValueError("invalid name") + + is_up = sympify(is_up) + ignore_updown = sympify(ignore_updown) + return Basic.__new__(cls, name_symbol, tensor_index_type, is_up, ignore_updown) + + @property + def ignore_updown(self): + return self.args[3] + + def __neg__(self): + t1 = WildTensorIndex(self.name, self.tensor_index_type, + (not self.is_up), self.ignore_updown) + return t1 + + def matches(self, expr, repl_dict=None, old=False): + if not isinstance(expr, TensorIndex): + return None + if self.tensor_index_type != expr.tensor_index_type: + return None + if not self.ignore_updown: + if self.is_up != expr.is_up: + return None + + if repl_dict is None: + repl_dict = {} + else: + repl_dict = repl_dict.copy() + + repl_dict[self] = expr + return repl_dict + + +class _WildTensExpr(Basic): + """ + INTERNAL USE ONLY + + This is an object that helps with replacement of WildTensors in expressions. + When this object is set as the tensor_head of a WildTensor, it replaces the + WildTensor by a TensExpr (passed when initializing this object). + + Examples + ======== + >>> from sympy.tensor.tensor import WildTensorHead, TensorIndex, TensorHead, TensorIndexType + >>> W = WildTensorHead("W") + >>> R3 = TensorIndexType('R3', dim=3) + >>> p = TensorIndex('p', R3) + >>> q = TensorIndex('q', R3) + >>> K = TensorHead('K', [R3]) + >>> print( ( K(p) ).replace( W(p), W(q)*W(-q)*W(p) ) ) + K(R_0)*K(-R_0)*K(p) + + """ + def __init__(self, expr): + if not isinstance(expr, TensExpr): + raise TypeError("_WildTensExpr expects a TensExpr as argument") + self.expr = expr + + def __call__(self, *indices): + return self.expr._replace_indices(dict(zip(self.expr.get_free_indices(), indices))) + + def __neg__(self): + return self.func(self.expr*S.NegativeOne) + + def __abs__(self): + raise NotImplementedError + + def __add__(self, other): + if other.func != self.func: + raise TypeError(f"Cannot add {self.func} to {other.func}") + return self.func(self.expr+other.expr) + + def __radd__(self, other): + if other.func != self.func: + raise TypeError(f"Cannot add {self.func} to {other.func}") + return self.func(other.expr+self.expr) + + def __sub__(self, other): + return self + (-other) + + def __rsub__(self, other): + return other + (-self) + + def __mul__(self, other): + raise NotImplementedError + + def __rmul__(self, other): + raise NotImplementedError + + def __truediv__(self, other): + raise NotImplementedError + + def __rtruediv__(self, other): + raise NotImplementedError + + def __pow__(self, other): + raise NotImplementedError + + def __rpow__(self, other): + raise NotImplementedError + + +def canon_bp(p): + """ + Butler-Portugal canonicalization. See ``tensor_can.py`` from the + combinatorics module for the details. + """ + if isinstance(p, TensExpr): + return p.canon_bp() + return p + + +def tensor_mul(*a): + """ + product of tensors + """ + if not a: + return TensMul.from_data(S.One, [], [], []) + t = a[0] + for tx in a[1:]: + t = t*tx + return t + + +def riemann_cyclic_replace(t_r): + """ + replace Riemann tensor with an equivalent expression + + ``R(m,n,p,q) -> 2/3*R(m,n,p,q) - 1/3*R(m,q,n,p) + 1/3*R(m,p,n,q)`` + + """ + free = sorted(t_r.free, key=lambda x: x[1]) + m, n, p, q = [x[0] for x in free] + t0 = t_r*Rational(2, 3) + t1 = -t_r.substitute_indices((m,m),(n,q),(p,n),(q,p))*Rational(1, 3) + t2 = t_r.substitute_indices((m,m),(n,p),(p,n),(q,q))*Rational(1, 3) + t3 = t0 + t1 + t2 + return t3 + +def riemann_cyclic(t2): + """ + Replace each Riemann tensor with an equivalent expression + satisfying the cyclic identity. + + This trick is discussed in the reference guide to Cadabra. + + Examples + ======== + + >>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorHead, riemann_cyclic, TensorSymmetry + >>> Lorentz = TensorIndexType('Lorentz', dummy_name='L') + >>> i, j, k, l = tensor_indices('i,j,k,l', Lorentz) + >>> R = TensorHead('R', [Lorentz]*4, TensorSymmetry.riemann()) + >>> t = R(i,j,k,l)*(R(-i,-j,-k,-l) - 2*R(-i,-k,-j,-l)) + >>> riemann_cyclic(t) + 0 + """ + t2 = t2.expand() + if isinstance(t2, (TensMul, Tensor)): + args = [t2] + else: + args = t2.args + a1 = [x.split() for x in args] + a2 = [[riemann_cyclic_replace(tx) for tx in y] for y in a1] + a3 = [tensor_mul(*v) for v in a2] + t3 = TensAdd(*a3).doit(deep=False) + if not t3: + return t3 + else: + return canon_bp(t3) + + +def get_lines(ex, index_type): + """ + Returns ``(lines, traces, rest)`` for an index type, + where ``lines`` is the list of list of positions of a matrix line, + ``traces`` is the list of list of traced matrix lines, + ``rest`` is the rest of the elements of the tensor. + """ + def _join_lines(a): + i = 0 + while i < len(a): + x = a[i] + xend = x[-1] + xstart = x[0] + hit = True + while hit: + hit = False + for j in range(i + 1, len(a)): + if j >= len(a): + break + if a[j][0] == xend: + hit = True + x.extend(a[j][1:]) + xend = x[-1] + a.pop(j) + continue + if a[j][0] == xstart: + hit = True + a[i] = reversed(a[j][1:]) + x + x = a[i] + xstart = a[i][0] + a.pop(j) + continue + if a[j][-1] == xend: + hit = True + x.extend(reversed(a[j][:-1])) + xend = x[-1] + a.pop(j) + continue + if a[j][-1] == xstart: + hit = True + a[i] = a[j][:-1] + x + x = a[i] + xstart = x[0] + a.pop(j) + continue + i += 1 + return a + + arguments = ex.args + dt = {} + for c in ex.args: + if not isinstance(c, TensExpr): + continue + if c in dt: + continue + index_types = c.index_types + a = [] + for i in range(len(index_types)): + if index_types[i] is index_type: + a.append(i) + if len(a) > 2: + raise ValueError('at most two indices of type %s allowed' % index_type) + if len(a) == 2: + dt[c] = a + #dum = ex.dum + lines = [] + traces = [] + traces1 = [] + #indices_to_args_pos = ex._get_indices_to_args_pos() + # TODO: add a dum_to_components_map ? + for p0, p1, c0, c1 in ex.dum_in_args: + if arguments[c0] not in dt: + continue + if c0 == c1: + traces.append([c0]) + continue + ta0 = dt[arguments[c0]] + ta1 = dt[arguments[c1]] + if p0 not in ta0: + continue + if ta0.index(p0) == ta1.index(p1): + # case gamma(i,s0,-s1) in c0, gamma(j,-s0,s2) in c1; + # to deal with this case one could add to the position + # a flag for transposition; + # one could write [(c0, False), (c1, True)] + raise NotImplementedError + # if p0 == ta0[1] then G in pos c0 is mult on the right by G in c1 + # if p0 == ta0[0] then G in pos c1 is mult on the right by G in c0 + ta0 = dt[arguments[c0]] + b0, b1 = (c0, c1) if p0 == ta0[1] else (c1, c0) + lines1 = lines.copy() + for line in lines: + if line[-1] == b0: + if line[0] == b1: + n = line.index(min(line)) + traces1.append(line) + traces.append(line[n:] + line[:n]) + else: + line.append(b1) + break + elif line[0] == b1: + line.insert(0, b0) + break + else: + lines1.append([b0, b1]) + + lines = [x for x in lines1 if x not in traces1] + lines = _join_lines(lines) + rest = [] + for line in lines: + for y in line: + rest.append(y) + for line in traces: + for y in line: + rest.append(y) + rest = [x for x in range(len(arguments)) if x not in rest] + + return lines, traces, rest + + +def get_free_indices(t): + if not isinstance(t, TensExpr): + return () + return t.get_free_indices() + + +def get_indices(t): + if not isinstance(t, TensExpr): + return () + return t.get_indices() + +def get_dummy_indices(t): + if not isinstance(t, TensExpr): + return () + inds = t.get_indices() + free = t.get_free_indices() + return [i for i in inds if i not in free] + +def get_index_structure(t): + if isinstance(t, TensExpr): + return t._index_structure + return _IndexStructure([], [], [], []) + + +def get_coeff(t): + if isinstance(t, Tensor): + return S.One + if isinstance(t, TensMul): + return t.coeff + if isinstance(t, TensExpr): + raise ValueError("no coefficient associated to this tensor expression") + return t + +def contract_metric(t, g): + if isinstance(t, TensExpr): + return t.contract_metric(g) + return t + +def perm2tensor(t, g, is_canon_bp=False): + """ + Returns the tensor corresponding to the permutation ``g`` + + For further details, see the method in ``TIDS`` with the same name. + """ + if not isinstance(t, TensExpr): + return t + elif isinstance(t, (Tensor, TensMul)): + nim = get_index_structure(t).perm2tensor(g, is_canon_bp=is_canon_bp) + res = t._set_new_index_structure(nim, is_canon_bp=is_canon_bp) + if g[-1] != len(g) - 1: + return -res + + return res + raise NotImplementedError() + + +def substitute_indices(t, *index_tuples): + if not isinstance(t, TensExpr): + return t + return t.substitute_indices(*index_tuples) + + +def _get_wilds(expr): + return list(expr.atoms(Wild, WildFunction, WildTensor, WildTensorIndex, WildTensorHead)) + + +def get_postprocessor(cls): + def _postprocessor(expr): + tens_class = {Mul: TensMul, Add: TensAdd}[cls] + if any(isinstance(a, TensExpr) for a in expr.args): + return tens_class(*expr.args) + else: + return expr + + return _postprocessor + +Basic._constructor_postprocessor_mapping[TensExpr] = { + "Mul": [get_postprocessor(Mul)], +} diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_functions.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_functions.py new file mode 100644 index 0000000000000000000000000000000000000000..ae40865d1bddffaa976dc3d94ae1ef1b6c97ca35 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_functions.py @@ -0,0 +1,57 @@ +from sympy.tensor.functions import TensorProduct +from sympy.matrices.dense import Matrix +from sympy.matrices.expressions.matexpr import MatrixSymbol +from sympy.tensor.array import Array +from sympy.abc import x, y, z +from sympy.abc import i, j, k, l + + +A = MatrixSymbol("A", 3, 3) +B = MatrixSymbol("B", 3, 3) +C = MatrixSymbol("C", 3, 3) + + +def test_TensorProduct_construction(): + assert TensorProduct(3, 4) == 12 + assert isinstance(TensorProduct(A, A), TensorProduct) + + expr = TensorProduct(TensorProduct(x, y), z) + assert expr == x*y*z + + expr = TensorProduct(TensorProduct(A, B), C) + assert expr == TensorProduct(A, B, C) + + expr = TensorProduct(Matrix.eye(2), Array([[0, -1], [1, 0]])) + assert expr == Array([ + [ + [[0, -1], [1, 0]], + [[0, 0], [0, 0]] + ], + [ + [[0, 0], [0, 0]], + [[0, -1], [1, 0]] + ] + ]) + + +def test_TensorProduct_shape(): + + expr = TensorProduct(3, 4, evaluate=False) + assert expr.shape == () + assert expr.rank() == 0 + + expr = TensorProduct(Array([1, 2]), Array([x, y]), evaluate=False) + assert expr.shape == (2, 2) + assert expr.rank() == 2 + expr = TensorProduct(expr, expr, evaluate=False) + assert expr.shape == (2, 2, 2, 2) + assert expr.rank() == 4 + + expr = TensorProduct(Matrix.eye(2), Array([[0, -1], [1, 0]]), evaluate=False) + assert expr.shape == (2, 2, 2, 2) + assert expr.rank() == 4 + + +def test_TensorProduct_getitem(): + expr = TensorProduct(A, B) + assert expr[i, j, k, l] == A[i, j]*B[k, l] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_index_methods.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_index_methods.py new file mode 100644 index 0000000000000000000000000000000000000000..df20f7e7c1ab392321e8350b95dd07c5639c1865 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_index_methods.py @@ -0,0 +1,227 @@ +from sympy.core import symbols, S, Pow, Function +from sympy.functions import exp +from sympy.testing.pytest import raises +from sympy.tensor.indexed import Idx, IndexedBase +from sympy.tensor.index_methods import IndexConformanceException + +from sympy.tensor.index_methods import (get_contraction_structure, get_indices) + + +def test_trivial_indices(): + x, y = symbols('x y') + assert get_indices(x) == (set(), {}) + assert get_indices(x*y) == (set(), {}) + assert get_indices(x + y) == (set(), {}) + assert get_indices(x**y) == (set(), {}) + + +def test_get_indices_Indexed(): + x = IndexedBase('x') + i, j = Idx('i'), Idx('j') + assert get_indices(x[i, j]) == ({i, j}, {}) + assert get_indices(x[j, i]) == ({j, i}, {}) + + +def test_get_indices_Idx(): + f = Function('f') + i, j = Idx('i'), Idx('j') + assert get_indices(f(i)*j) == ({i, j}, {}) + assert get_indices(f(j, i)) == ({j, i}, {}) + assert get_indices(f(i)*i) == (set(), {}) + + +def test_get_indices_mul(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j = Idx('i'), Idx('j') + assert get_indices(x[j]*y[i]) == ({i, j}, {}) + assert get_indices(x[i]*y[j]) == ({i, j}, {}) + + +def test_get_indices_exceptions(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j = Idx('i'), Idx('j') + raises(IndexConformanceException, lambda: get_indices(x[i] + y[j])) + + +def test_scalar_broadcast(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j = Idx('i'), Idx('j') + assert get_indices(x[i] + y[i, i]) == ({i}, {}) + assert get_indices(x[i] + y[j, j]) == ({i}, {}) + + +def test_get_indices_add(): + x = IndexedBase('x') + y = IndexedBase('y') + A = IndexedBase('A') + i, j, k = Idx('i'), Idx('j'), Idx('k') + assert get_indices(x[i] + 2*y[i]) == ({i}, {}) + assert get_indices(y[i] + 2*A[i, j]*x[j]) == ({i}, {}) + assert get_indices(y[i] + 2*(x[i] + A[i, j]*x[j])) == ({i}, {}) + assert get_indices(y[i] + x[i]*(A[j, j] + 1)) == ({i}, {}) + assert get_indices( + y[i] + x[i]*x[j]*(y[j] + A[j, k]*x[k])) == ({i}, {}) + + +def test_get_indices_Pow(): + x = IndexedBase('x') + y = IndexedBase('y') + A = IndexedBase('A') + i, j, k = Idx('i'), Idx('j'), Idx('k') + assert get_indices(Pow(x[i], y[j])) == ({i, j}, {}) + assert get_indices(Pow(x[i, k], y[j, k])) == ({i, j, k}, {}) + assert get_indices(Pow(A[i, k], y[k] + A[k, j]*x[j])) == ({i, k}, {}) + assert get_indices(Pow(2, x[i])) == get_indices(exp(x[i])) + + # test of a design decision, this may change: + assert get_indices(Pow(x[i], 2)) == ({i}, {}) + + +def test_get_contraction_structure_basic(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j = Idx('i'), Idx('j') + assert get_contraction_structure(x[i]*y[j]) == {None: {x[i]*y[j]}} + assert get_contraction_structure(x[i] + y[j]) == {None: {x[i], y[j]}} + assert get_contraction_structure(x[i]*y[i]) == {(i,): {x[i]*y[i]}} + assert get_contraction_structure( + 1 + x[i]*y[i]) == {None: {S.One}, (i,): {x[i]*y[i]}} + assert get_contraction_structure(x[i]**y[i]) == {None: {x[i]**y[i]}} + + +def test_get_contraction_structure_complex(): + x = IndexedBase('x') + y = IndexedBase('y') + A = IndexedBase('A') + i, j, k = Idx('i'), Idx('j'), Idx('k') + expr1 = y[i] + A[i, j]*x[j] + d1 = {None: {y[i]}, (j,): {A[i, j]*x[j]}} + assert get_contraction_structure(expr1) == d1 + expr2 = expr1*A[k, i] + x[k] + d2 = {None: {x[k]}, (i,): {expr1*A[k, i]}, expr1*A[k, i]: [d1]} + assert get_contraction_structure(expr2) == d2 + + +def test_contraction_structure_simple_Pow(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j, k = Idx('i'), Idx('j'), Idx('k') + ii_jj = x[i, i]**y[j, j] + assert get_contraction_structure(ii_jj) == { + None: {ii_jj}, + ii_jj: [ + {(i,): {x[i, i]}}, + {(j,): {y[j, j]}} + ] + } + + ii_jk = x[i, i]**y[j, k] + assert get_contraction_structure(ii_jk) == { + None: {x[i, i]**y[j, k]}, + x[i, i]**y[j, k]: [ + {(i,): {x[i, i]}} + ] + } + + +def test_contraction_structure_Mul_and_Pow(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j, k = Idx('i'), Idx('j'), Idx('k') + + i_ji = x[i]**(y[j]*x[i]) + assert get_contraction_structure(i_ji) == {None: {i_ji}} + ij_i = (x[i]*y[j])**(y[i]) + assert get_contraction_structure(ij_i) == {None: {ij_i}} + j_ij_i = x[j]*(x[i]*y[j])**(y[i]) + assert get_contraction_structure(j_ij_i) == {(j,): {j_ij_i}} + j_i_ji = x[j]*x[i]**(y[j]*x[i]) + assert get_contraction_structure(j_i_ji) == {(j,): {j_i_ji}} + ij_exp_kki = x[i]*y[j]*exp(y[i]*y[k, k]) + result = get_contraction_structure(ij_exp_kki) + expected = { + (i,): {ij_exp_kki}, + ij_exp_kki: [{ + None: {exp(y[i]*y[k, k])}, + exp(y[i]*y[k, k]): [{ + None: {y[i]*y[k, k]}, + y[i]*y[k, k]: [{(k,): {y[k, k]}}] + }]} + ] + } + assert result == expected + + +def test_contraction_structure_Add_in_Pow(): + x = IndexedBase('x') + y = IndexedBase('y') + i, j, k = Idx('i'), Idx('j'), Idx('k') + s_ii_jj_s = (1 + x[i, i])**(1 + y[j, j]) + expected = { + None: {s_ii_jj_s}, + s_ii_jj_s: [ + {None: {S.One}, (i,): {x[i, i]}}, + {None: {S.One}, (j,): {y[j, j]}} + ] + } + result = get_contraction_structure(s_ii_jj_s) + assert result == expected + + s_ii_jk_s = (1 + x[i, i]) ** (1 + y[j, k]) + expected_2 = { + None: {(x[i, i] + 1)**(y[j, k] + 1)}, + s_ii_jk_s: [ + {None: {S.One}, (i,): {x[i, i]}} + ] + } + result_2 = get_contraction_structure(s_ii_jk_s) + assert result_2 == expected_2 + + +def test_contraction_structure_Pow_in_Pow(): + x = IndexedBase('x') + y = IndexedBase('y') + z = IndexedBase('z') + i, j, k = Idx('i'), Idx('j'), Idx('k') + ii_jj_kk = x[i, i]**y[j, j]**z[k, k] + expected = { + None: {ii_jj_kk}, + ii_jj_kk: [ + {(i,): {x[i, i]}}, + { + None: {y[j, j]**z[k, k]}, + y[j, j]**z[k, k]: [ + {(j,): {y[j, j]}}, + {(k,): {z[k, k]}} + ] + } + ] + } + assert get_contraction_structure(ii_jj_kk) == expected + + +def test_ufunc_support(): + f = Function('f') + g = Function('g') + x = IndexedBase('x') + y = IndexedBase('y') + i, j = Idx('i'), Idx('j') + a = symbols('a') + + assert get_indices(f(x[i])) == ({i}, {}) + assert get_indices(f(x[i], y[j])) == ({i, j}, {}) + assert get_indices(f(y[i])*g(x[i])) == (set(), {}) + assert get_indices(f(a, x[i])) == ({i}, {}) + assert get_indices(f(a, y[i], x[j])*g(x[i])) == ({j}, {}) + assert get_indices(g(f(x[i]))) == ({i}, {}) + + assert get_contraction_structure(f(x[i])) == {None: {f(x[i])}} + assert get_contraction_structure( + f(y[i])*g(x[i])) == {(i,): {f(y[i])*g(x[i])}} + assert get_contraction_structure( + f(y[i])*g(f(x[i]))) == {(i,): {f(y[i])*g(f(x[i]))}} + assert get_contraction_structure( + f(x[j], y[i])*g(x[i])) == {(i,): {f(x[j], y[i])*g(x[i])}} diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_indexed.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_indexed.py new file mode 100644 index 0000000000000000000000000000000000000000..689ec932c8fcefe0a24de289dd2ffd6820c63f19 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_indexed.py @@ -0,0 +1,511 @@ +from sympy.core import symbols, Symbol, Tuple, oo, Dummy +from sympy.tensor.indexed import IndexException +from sympy.testing.pytest import raises +from sympy.utilities.iterables import iterable + +# import test: +from sympy.concrete.summations import Sum +from sympy.core.function import Function, Subs, Derivative +from sympy.core.relational import (StrictLessThan, GreaterThan, + StrictGreaterThan, LessThan) +from sympy.core.singleton import S +from sympy.functions.elementary.exponential import exp, log +from sympy.functions.elementary.trigonometric import cos, sin +from sympy.functions.special.tensor_functions import KroneckerDelta +from sympy.series.order import Order +from sympy.sets.fancysets import Range +from sympy.tensor.indexed import IndexedBase, Idx, Indexed + + +def test_Idx_construction(): + i, a, b = symbols('i a b', integer=True) + assert Idx(i) != Idx(i, 1) + assert Idx(i, a) == Idx(i, (0, a - 1)) + assert Idx(i, oo) == Idx(i, (0, oo)) + + x = symbols('x', integer=False) + raises(TypeError, lambda: Idx(x)) + raises(TypeError, lambda: Idx(0.5)) + raises(TypeError, lambda: Idx(i, x)) + raises(TypeError, lambda: Idx(i, 0.5)) + raises(TypeError, lambda: Idx(i, (x, 5))) + raises(TypeError, lambda: Idx(i, (2, x))) + raises(TypeError, lambda: Idx(i, (2, 3.5))) + + +def test_Idx_properties(): + i, a, b = symbols('i a b', integer=True) + assert Idx(i).is_integer + assert Idx(i).name == 'i' + assert Idx(i + 2).name == 'i + 2' + assert Idx('foo').name == 'foo' + + +def test_Idx_bounds(): + i, a, b = symbols('i a b', integer=True) + assert Idx(i).lower is None + assert Idx(i).upper is None + assert Idx(i, a).lower == 0 + assert Idx(i, a).upper == a - 1 + assert Idx(i, 5).lower == 0 + assert Idx(i, 5).upper == 4 + assert Idx(i, oo).lower == 0 + assert Idx(i, oo).upper is oo + assert Idx(i, (a, b)).lower == a + assert Idx(i, (a, b)).upper == b + assert Idx(i, (1, 5)).lower == 1 + assert Idx(i, (1, 5)).upper == 5 + assert Idx(i, (-oo, oo)).lower is -oo + assert Idx(i, (-oo, oo)).upper is oo + + +def test_Idx_fixed_bounds(): + i, a, b, x = symbols('i a b x', integer=True) + assert Idx(x).lower is None + assert Idx(x).upper is None + assert Idx(x, a).lower == 0 + assert Idx(x, a).upper == a - 1 + assert Idx(x, 5).lower == 0 + assert Idx(x, 5).upper == 4 + assert Idx(x, oo).lower == 0 + assert Idx(x, oo).upper is oo + assert Idx(x, (a, b)).lower == a + assert Idx(x, (a, b)).upper == b + assert Idx(x, (1, 5)).lower == 1 + assert Idx(x, (1, 5)).upper == 5 + assert Idx(x, (-oo, oo)).lower is -oo + assert Idx(x, (-oo, oo)).upper is oo + + +def test_Idx_inequalities(): + i14 = Idx("i14", (1, 4)) + i79 = Idx("i79", (7, 9)) + i46 = Idx("i46", (4, 6)) + i35 = Idx("i35", (3, 5)) + + assert i14 <= 5 + assert i14 < 5 + assert not (i14 >= 5) + assert not (i14 > 5) + + assert 5 >= i14 + assert 5 > i14 + assert not (5 <= i14) + assert not (5 < i14) + + assert LessThan(i14, 5) + assert StrictLessThan(i14, 5) + assert not GreaterThan(i14, 5) + assert not StrictGreaterThan(i14, 5) + + assert i14 <= 4 + assert isinstance(i14 < 4, StrictLessThan) + assert isinstance(i14 >= 4, GreaterThan) + assert not (i14 > 4) + + assert isinstance(i14 <= 1, LessThan) + assert not (i14 < 1) + assert i14 >= 1 + assert isinstance(i14 > 1, StrictGreaterThan) + + assert not (i14 <= 0) + assert not (i14 < 0) + assert i14 >= 0 + assert i14 > 0 + + from sympy.abc import x + + assert isinstance(i14 < x, StrictLessThan) + assert isinstance(i14 > x, StrictGreaterThan) + assert isinstance(i14 <= x, LessThan) + assert isinstance(i14 >= x, GreaterThan) + + assert i14 < i79 + assert i14 <= i79 + assert not (i14 > i79) + assert not (i14 >= i79) + + assert i14 <= i46 + assert isinstance(i14 < i46, StrictLessThan) + assert isinstance(i14 >= i46, GreaterThan) + assert not (i14 > i46) + + assert isinstance(i14 < i35, StrictLessThan) + assert isinstance(i14 > i35, StrictGreaterThan) + assert isinstance(i14 <= i35, LessThan) + assert isinstance(i14 >= i35, GreaterThan) + + iNone1 = Idx("iNone1") + iNone2 = Idx("iNone2") + + assert isinstance(iNone1 < iNone2, StrictLessThan) + assert isinstance(iNone1 > iNone2, StrictGreaterThan) + assert isinstance(iNone1 <= iNone2, LessThan) + assert isinstance(iNone1 >= iNone2, GreaterThan) + + +def test_Idx_inequalities_current_fails(): + i14 = Idx("i14", (1, 4)) + + assert S(5) >= i14 + assert S(5) > i14 + assert not (S(5) <= i14) + assert not (S(5) < i14) + + +def test_Idx_func_args(): + i, a, b = symbols('i a b', integer=True) + ii = Idx(i) + assert ii.func(*ii.args) == ii + ii = Idx(i, a) + assert ii.func(*ii.args) == ii + ii = Idx(i, (a, b)) + assert ii.func(*ii.args) == ii + + +def test_Idx_subs(): + i, a, b = symbols('i a b', integer=True) + assert Idx(i, a).subs(a, b) == Idx(i, b) + assert Idx(i, a).subs(i, b) == Idx(b, a) + + assert Idx(i).subs(i, 2) == Idx(2) + assert Idx(i, a).subs(a, 2) == Idx(i, 2) + assert Idx(i, (a, b)).subs(i, 2) == Idx(2, (a, b)) + + +def test_IndexedBase_sugar(): + i, j = symbols('i j', integer=True) + a = symbols('a') + A1 = Indexed(a, i, j) + A2 = IndexedBase(a) + assert A1 == A2[i, j] + assert A1 == A2[(i, j)] + assert A1 == A2[[i, j]] + assert A1 == A2[Tuple(i, j)] + assert all(a.is_Integer for a in A2[1, 0].args[1:]) + + +def test_IndexedBase_subs(): + i = symbols('i', integer=True) + a, b = symbols('a b') + A = IndexedBase(a) + B = IndexedBase(b) + assert A[i] == B[i].subs(b, a) + C = {1: 2} + assert C[1] == A[1].subs(A, C) + + +def test_IndexedBase_shape(): + i, j, m, n = symbols('i j m n', integer=True) + a = IndexedBase('a', shape=(m, m)) + b = IndexedBase('a', shape=(m, n)) + assert b.shape == Tuple(m, n) + assert a[i, j] != b[i, j] + assert a[i, j] == b[i, j].subs(n, m) + assert b.func(*b.args) == b + assert b[i, j].func(*b[i, j].args) == b[i, j] + raises(IndexException, lambda: b[i]) + raises(IndexException, lambda: b[i, i, j]) + F = IndexedBase("F", shape=m) + assert F.shape == Tuple(m) + assert F[i].subs(i, j) == F[j] + raises(IndexException, lambda: F[i, j]) + + +def test_IndexedBase_assumptions(): + i = Symbol('i', integer=True) + a = Symbol('a') + A = IndexedBase(a, positive=True) + for c in (A, A[i]): + assert c.is_real + assert c.is_complex + assert not c.is_imaginary + assert c.is_nonnegative + assert c.is_nonzero + assert c.is_commutative + assert log(exp(c)) == c + + assert A != IndexedBase(a) + assert A == IndexedBase(a, positive=True, real=True) + assert A[i] != Indexed(a, i) + + +def test_IndexedBase_assumptions_inheritance(): + I = Symbol('I', integer=True) + I_inherit = IndexedBase(I) + I_explicit = IndexedBase('I', integer=True) + + assert I_inherit.is_integer + assert I_explicit.is_integer + assert I_inherit.label.is_integer + assert I_explicit.label.is_integer + assert I_inherit == I_explicit + + +def test_issue_17652(): + """Regression test issue #17652. + + IndexedBase.label should not upcast subclasses of Symbol + """ + class SubClass(Symbol): + pass + + x = SubClass('X') + assert type(x) == SubClass + base = IndexedBase(x) + assert type(x) == SubClass + assert type(base.label) == SubClass + + +def test_Indexed_constructor(): + i, j = symbols('i j', integer=True) + A = Indexed('A', i, j) + assert A == Indexed(Symbol('A'), i, j) + assert A == Indexed(IndexedBase('A'), i, j) + raises(TypeError, lambda: Indexed(A, i, j)) + raises(IndexException, lambda: Indexed("A")) + assert A.free_symbols == {A, A.base.label, i, j} + + +def test_Indexed_func_args(): + i, j = symbols('i j', integer=True) + a = symbols('a') + A = Indexed(a, i, j) + assert A == A.func(*A.args) + + +def test_Indexed_subs(): + i, j, k = symbols('i j k', integer=True) + a, b = symbols('a b') + A = IndexedBase(a) + B = IndexedBase(b) + assert A[i, j] == B[i, j].subs(b, a) + assert A[i, j] == A[i, k].subs(k, j) + + +def test_Indexed_properties(): + i, j = symbols('i j', integer=True) + A = Indexed('A', i, j) + assert A.name == 'A[i, j]' + assert A.rank == 2 + assert A.indices == (i, j) + assert A.base == IndexedBase('A') + assert A.ranges == [None, None] + raises(IndexException, lambda: A.shape) + + n, m = symbols('n m', integer=True) + assert Indexed('A', Idx( + i, m), Idx(j, n)).ranges == [Tuple(0, m - 1), Tuple(0, n - 1)] + assert Indexed('A', Idx(i, m), Idx(j, n)).shape == Tuple(m, n) + raises(IndexException, lambda: Indexed("A", Idx(i, m), Idx(j)).shape) + + +def test_Indexed_shape_precedence(): + i, j = symbols('i j', integer=True) + o, p = symbols('o p', integer=True) + n, m = symbols('n m', integer=True) + a = IndexedBase('a', shape=(o, p)) + assert a.shape == Tuple(o, p) + assert Indexed( + a, Idx(i, m), Idx(j, n)).ranges == [Tuple(0, m - 1), Tuple(0, n - 1)] + assert Indexed(a, Idx(i, m), Idx(j, n)).shape == Tuple(o, p) + assert Indexed( + a, Idx(i, m), Idx(j)).ranges == [Tuple(0, m - 1), (None, None)] + assert Indexed(a, Idx(i, m), Idx(j)).shape == Tuple(o, p) + + +def test_complex_indices(): + i, j = symbols('i j', integer=True) + A = Indexed('A', i, i + j) + assert A.rank == 2 + assert A.indices == (i, i + j) + + +def test_not_interable(): + i, j = symbols('i j', integer=True) + A = Indexed('A', i, i + j) + assert not iterable(A) + + +def test_Indexed_coeff(): + N = Symbol('N', integer=True) + len_y = N + i = Idx('i', len_y-1) + y = IndexedBase('y', shape=(len_y,)) + a = (1/y[i+1]*y[i]).coeff(y[i]) + b = (y[i]/y[i+1]).coeff(y[i]) + assert a == b + + +def test_differentiation(): + from sympy.functions.special.tensor_functions import KroneckerDelta + i, j, k, l = symbols('i j k l', cls=Idx) + a = symbols('a') + m, n = symbols("m, n", integer=True, finite=True) + assert m.is_real + h, L = symbols('h L', cls=IndexedBase) + hi, hj = h[i], h[j] + + expr = hi + assert expr.diff(hj) == KroneckerDelta(i, j) + assert expr.diff(hi) == KroneckerDelta(i, i) + + expr = S(2) * hi + assert expr.diff(hj) == S(2) * KroneckerDelta(i, j) + assert expr.diff(hi) == S(2) * KroneckerDelta(i, i) + assert expr.diff(a) is S.Zero + + assert Sum(expr, (i, -oo, oo)).diff(hj) == Sum(2*KroneckerDelta(i, j), (i, -oo, oo)) + assert Sum(expr.diff(hj), (i, -oo, oo)) == Sum(2*KroneckerDelta(i, j), (i, -oo, oo)) + assert Sum(expr, (i, -oo, oo)).diff(hj).doit() == 2 + + assert Sum(expr.diff(hi), (i, -oo, oo)).doit() == Sum(2, (i, -oo, oo)).doit() + assert Sum(expr, (i, -oo, oo)).diff(hi).doit() is oo + + expr = a * hj * hj / S(2) + assert expr.diff(hi) == a * h[j] * KroneckerDelta(i, j) + assert expr.diff(a) == hj * hj / S(2) + assert expr.diff(a, 2) is S.Zero + + assert Sum(expr, (i, -oo, oo)).diff(hi) == Sum(a*KroneckerDelta(i, j)*h[j], (i, -oo, oo)) + assert Sum(expr.diff(hi), (i, -oo, oo)) == Sum(a*KroneckerDelta(i, j)*h[j], (i, -oo, oo)) + assert Sum(expr, (i, -oo, oo)).diff(hi).doit() == a*h[j] + + assert Sum(expr, (j, -oo, oo)).diff(hi) == Sum(a*KroneckerDelta(i, j)*h[j], (j, -oo, oo)) + assert Sum(expr.diff(hi), (j, -oo, oo)) == Sum(a*KroneckerDelta(i, j)*h[j], (j, -oo, oo)) + assert Sum(expr, (j, -oo, oo)).diff(hi).doit() == a*h[i] + + expr = a * sin(hj * hj) + assert expr.diff(hi) == 2*a*cos(hj * hj) * hj * KroneckerDelta(i, j) + assert expr.diff(hj) == 2*a*cos(hj * hj) * hj + + expr = a * L[i, j] * h[j] + assert expr.diff(hi) == a*L[i, j]*KroneckerDelta(i, j) + assert expr.diff(hj) == a*L[i, j] + assert expr.diff(L[i, j]) == a*h[j] + assert expr.diff(L[k, l]) == a*KroneckerDelta(i, k)*KroneckerDelta(j, l)*h[j] + assert expr.diff(L[i, l]) == a*KroneckerDelta(j, l)*h[j] + + assert Sum(expr, (j, -oo, oo)).diff(L[k, l]) == Sum(a * KroneckerDelta(i, k) * KroneckerDelta(j, l) * h[j], (j, -oo, oo)) + assert Sum(expr, (j, -oo, oo)).diff(L[k, l]).doit() == a * KroneckerDelta(i, k) * h[l] + + assert h[m].diff(h[m]) == 1 + assert h[m].diff(h[n]) == KroneckerDelta(m, n) + assert Sum(a*h[m], (m, -oo, oo)).diff(h[n]) == Sum(a*KroneckerDelta(m, n), (m, -oo, oo)) + assert Sum(a*h[m], (m, -oo, oo)).diff(h[n]).doit() == a + assert Sum(a*h[m], (n, -oo, oo)).diff(h[n]) == Sum(a*KroneckerDelta(m, n), (n, -oo, oo)) + assert Sum(a*h[m], (m, -oo, oo)).diff(h[m]).doit() == oo*a + + +def test_indexed_series(): + A = IndexedBase("A") + i = symbols("i", integer=True) + assert sin(A[i]).series(A[i]) == A[i] - A[i]**3/6 + A[i]**5/120 + Order(A[i]**6, A[i]) + + +def test_indexed_is_constant(): + A = IndexedBase("A") + i, j, k = symbols("i,j,k") + assert not A[i].is_constant() + assert A[i].is_constant(j) + assert not A[1+2*i, k].is_constant() + assert not A[1+2*i, k].is_constant(i) + assert A[1+2*i, k].is_constant(j) + assert not A[1+2*i, k].is_constant(k) + + +def test_issue_12533(): + d = IndexedBase('d') + assert IndexedBase(range(5)) == Range(0, 5, 1) + assert d[0].subs(Symbol("d"), range(5)) == 0 + assert d[0].subs(d, range(5)) == 0 + assert d[1].subs(d, range(5)) == 1 + assert Indexed(Range(5), 2) == 2 + + +def test_issue_12780(): + n = symbols("n") + i = Idx("i", (0, n)) + raises(TypeError, lambda: i.subs(n, 1.5)) + + +def test_issue_18604(): + m = symbols("m") + assert Idx("i", m).name == 'i' + assert Idx("i", m).lower == 0 + assert Idx("i", m).upper == m - 1 + m = symbols("m", real=False) + raises(TypeError, lambda: Idx("i", m)) + +def test_Subs_with_Indexed(): + A = IndexedBase("A") + i, j, k = symbols("i,j,k") + x, y, z = symbols("x,y,z") + f = Function("f") + + assert Subs(A[i], A[i], A[j]).diff(A[j]) == 1 + assert Subs(A[i], A[i], x).diff(A[i]) == 0 + assert Subs(A[i], A[i], x).diff(A[j]) == 0 + assert Subs(A[i], A[i], x).diff(x) == 1 + assert Subs(A[i], A[i], x).diff(y) == 0 + assert Subs(A[i], A[i], A[j]).diff(A[k]) == KroneckerDelta(j, k) + assert Subs(x, x, A[i]).diff(A[j]) == KroneckerDelta(i, j) + assert Subs(f(A[i]), A[i], x).diff(A[j]) == 0 + assert Subs(f(A[i]), A[i], A[k]).diff(A[j]) == Derivative(f(A[k]), A[k])*KroneckerDelta(j, k) + assert Subs(x, x, A[i]**2).diff(A[j]) == 2*KroneckerDelta(i, j)*A[i] + assert Subs(A[i], A[i], A[j]**2).diff(A[k]) == 2*KroneckerDelta(j, k)*A[j] + + assert Subs(A[i]*x, x, A[i]).diff(A[i]) == 2*A[i] + assert Subs(A[i]*x, x, A[i]).diff(A[j]) == 2*A[i]*KroneckerDelta(i, j) + assert Subs(A[i]*x, x, A[j]).diff(A[i]) == A[j] + A[i]*KroneckerDelta(i, j) + assert Subs(A[i]*x, x, A[j]).diff(A[j]) == A[i] + A[j]*KroneckerDelta(i, j) + assert Subs(A[i]*x, x, A[i]).diff(A[k]) == 2*A[i]*KroneckerDelta(i, k) + assert Subs(A[i]*x, x, A[j]).diff(A[k]) == KroneckerDelta(i, k)*A[j] + KroneckerDelta(j, k)*A[i] + + assert Subs(A[i]*x, A[i], x).diff(A[i]) == 0 + assert Subs(A[i]*x, A[i], x).diff(A[j]) == 0 + assert Subs(A[i]*x, A[j], x).diff(A[i]) == x + assert Subs(A[i]*x, A[j], x).diff(A[j]) == x*KroneckerDelta(i, j) + assert Subs(A[i]*x, A[i], x).diff(A[k]) == 0 + assert Subs(A[i]*x, A[j], x).diff(A[k]) == x*KroneckerDelta(i, k) + + +def test_complicated_derivative_with_Indexed(): + x, y = symbols("x,y", cls=IndexedBase) + sigma = symbols("sigma") + i, j, k = symbols("i,j,k") + m0,m1,m2,m3,m4,m5 = symbols("m0:6") + f = Function("f") + + expr = f((x[i] - y[i])**2/sigma) + _xi_1 = symbols("xi_1", cls=Dummy) + assert expr.diff(x[m0]).dummy_eq( + (x[i] - y[i])*KroneckerDelta(i, m0)*\ + 2*Subs( + Derivative(f(_xi_1), _xi_1), + (_xi_1,), + ((x[i] - y[i])**2/sigma,) + )/sigma + ) + assert expr.diff(x[m0]).diff(x[m1]).dummy_eq( + 2*KroneckerDelta(i, m0)*\ + KroneckerDelta(i, m1)*Subs( + Derivative(f(_xi_1), _xi_1), + (_xi_1,), + ((x[i] - y[i])**2/sigma,) + )/sigma + \ + 4*(x[i] - y[i])**2*KroneckerDelta(i, m0)*KroneckerDelta(i, m1)*\ + Subs( + Derivative(f(_xi_1), _xi_1, _xi_1), + (_xi_1,), + ((x[i] - y[i])**2/sigma,) + )/sigma**2 + ) + + +def test_IndexedBase_commutative(): + t = IndexedBase('t', commutative=False) + u = IndexedBase('u', commutative=False) + v = IndexedBase('v') + assert t[0]*v[0] == v[0]*t[0] + assert t[0]*u[0] != u[0]*t[0] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_printing.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_printing.py new file mode 100644 index 0000000000000000000000000000000000000000..9f3cf7f0591a7012c93354ab7b8d7e010def38bb --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_printing.py @@ -0,0 +1,13 @@ +from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorHead +from sympy import I + +def test_printing_TensMul(): + R3 = TensorIndexType('R3', dim=3) + p, q = tensor_indices("p q", R3) + K = TensorHead("K", [R3]) + + assert repr(2*K(p)) == "2*K(p)" + assert repr(-K(p)) == "-K(p)" + assert repr(-2*K(p)*K(q)) == "-2*K(p)*K(q)" + assert repr(-I*K(p)) == "-I*K(p)" + assert repr(I*K(p)) == "I*K(p)" diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_tensor.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_tensor.py new file mode 100644 index 0000000000000000000000000000000000000000..3113f5be9bcd32224f3525b5d831b6d7476c39e3 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/tensor/tests/test_tensor.py @@ -0,0 +1,2218 @@ +from sympy.concrete.summations import Sum +from sympy.core.function import expand +from sympy.core.numbers import Integer +from sympy.matrices.dense import (Matrix, eye) +from sympy.tensor.indexed import Indexed +from sympy.combinatorics import Permutation +from sympy.core import S, Rational, Symbol, Basic, Add, Wild, Function +from sympy.core.containers import Tuple +from sympy.core.symbol import symbols +from sympy.functions.elementary.miscellaneous import sqrt +from sympy.integrals import integrate +from sympy.tensor.array import Array +from sympy.tensor.tensor import TensorIndexType, tensor_indices, TensorSymmetry, \ + get_symmetric_group_sgs, TensorIndex, tensor_mul, TensAdd, \ + riemann_cyclic_replace, riemann_cyclic, TensMul, tensor_heads, \ + TensorManager, TensExpr, TensorHead, canon_bp, \ + tensorhead, tensorsymmetry, TensorType, substitute_indices, \ + WildTensorIndex, WildTensorHead, _WildTensExpr +from sympy.testing.pytest import raises, XFAIL, warns_deprecated_sympy +from sympy.matrices import diag + +def _is_equal(arg1, arg2): + if isinstance(arg1, TensExpr): + return arg1.equals(arg2) + elif isinstance(arg2, TensExpr): + return arg2.equals(arg1) + return arg1 == arg2 + + +#################### Tests from tensor_can.py ####################### +def test_canonicalize_no_slot_sym(): + # A_d0 * B^d0; T_c = A^d0*B_d0 + Lorentz = TensorIndexType('Lorentz', dummy_name='L') + a, b, d0, d1 = tensor_indices('a,b,d0,d1', Lorentz) + A, B = tensor_heads('A,B', [Lorentz], TensorSymmetry.no_symmetry(1)) + t = A(-d0)*B(d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0)*B(-L_0)' + + # A^a * B^b; T_c = T + t = A(a)*B(b) + tc = t.canon_bp() + assert tc == t + # B^b * A^a + t1 = B(b)*A(a) + tc = t1.canon_bp() + assert str(tc) == 'A(a)*B(b)' + + # A symmetric + # A^{b}_{d0}*A^{d0, a}; T_c = A^{a d0}*A{b}_{d0} + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + t = A(b, -d0)*A(d0, a) + tc = t.canon_bp() + assert str(tc) == 'A(a, L_0)*A(b, -L_0)' + + # A^{d1}_{d0}*B^d0*C_d1 + # T_c = A^{d0 d1}*B_d0*C_d1 + B, C = tensor_heads('B,C', [Lorentz], TensorSymmetry.no_symmetry(1)) + t = A(d1, -d0)*B(d0)*C(-d1) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-L_0)*C(-L_1)' + + # A without symmetry + # A^{d1}_{d0}*B^d0*C_d1 ord=[d0,-d0,d1,-d1]; g = [2,1,0,3,4,5] + # T_c = A^{d0 d1}*B_d1*C_d0; can = [0,2,3,1,4,5] + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.no_symmetry(2)) + t = A(d1, -d0)*B(d0)*C(-d1) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-L_1)*C(-L_0)' + + # A, B without symmetry + # A^{d1}_{d0}*B_{d1}^{d0} + # T_c = A^{d0 d1}*B_{d0 d1} + B = TensorHead('B', [Lorentz]*2, TensorSymmetry.no_symmetry(2)) + t = A(d1, -d0)*B(-d1, d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-L_0, -L_1)' + # A_{d0}^{d1}*B_{d1}^{d0} + # T_c = A^{d0 d1}*B_{d1 d0} + t = A(-d0, d1)*B(-d1, d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-L_1, -L_0)' + + # A, B, C without symmetry + # A^{d1 d0}*B_{a d0}*C_{d1 b} + # T_c=A^{d0 d1}*B_{a d1}*C_{d0 b} + C = TensorHead('C', [Lorentz]*2, TensorSymmetry.no_symmetry(2)) + t = A(d1, d0)*B(-a, -d0)*C(-d1, -b) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-a, -L_1)*C(-L_0, -b)' + + # A symmetric, B and C without symmetry + # A^{d1 d0}*B_{a d0}*C_{d1 b} + # T_c = A^{d0 d1}*B_{a d0}*C_{d1 b} + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + t = A(d1, d0)*B(-a, -d0)*C(-d1, -b) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-a, -L_0)*C(-L_1, -b)' + + # A and C symmetric, B without symmetry + # A^{d1 d0}*B_{a d0}*C_{d1 b} ord=[a,b,d0,-d0,d1,-d1] + # T_c = A^{d0 d1}*B_{a d0}*C_{b d1} + C = TensorHead('C', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + t = A(d1, d0)*B(-a, -d0)*C(-d1, -b) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1)*B(-a, -L_0)*C(-b, -L_1)' + +def test_canonicalize_no_dummies(): + Lorentz = TensorIndexType('Lorentz', dummy_name='L') + a, b, c, d = tensor_indices('a, b, c, d', Lorentz) + + # A commuting + # A^c A^b A^a + # T_c = A^a A^b A^c + A = TensorHead('A', [Lorentz], TensorSymmetry.no_symmetry(1)) + t = A(c)*A(b)*A(a) + tc = t.canon_bp() + assert str(tc) == 'A(a)*A(b)*A(c)' + + # A anticommuting + # A^c A^b A^a + # T_c = -A^a A^b A^c + A = TensorHead('A', [Lorentz], TensorSymmetry.no_symmetry(1), 1) + t = A(c)*A(b)*A(a) + tc = t.canon_bp() + assert str(tc) == '-A(a)*A(b)*A(c)' + + # A commuting and symmetric + # A^{b,d}*A^{c,a} + # T_c = A^{a c}*A^{b d} + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + t = A(b, d)*A(c, a) + tc = t.canon_bp() + assert str(tc) == 'A(a, c)*A(b, d)' + + # A anticommuting and symmetric + # A^{b,d}*A^{c,a} + # T_c = -A^{a c}*A^{b d} + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.fully_symmetric(2), 1) + t = A(b, d)*A(c, a) + tc = t.canon_bp() + assert str(tc) == '-A(a, c)*A(b, d)' + + # A^{c,a}*A^{b,d} + # T_c = A^{a c}*A^{b d} + t = A(c, a)*A(b, d) + tc = t.canon_bp() + assert str(tc) == 'A(a, c)*A(b, d)' + +def test_tensorhead_construction_without_symmetry(): + L = TensorIndexType('Lorentz') + A1 = TensorHead('A', [L, L]) + A2 = TensorHead('A', [L, L], TensorSymmetry.no_symmetry(2)) + assert A1 == A2 + A3 = TensorHead('A', [L, L], TensorSymmetry.fully_symmetric(2)) # Symmetric + assert A1 != A3 + +def test_no_metric_symmetry(): + # no metric symmetry; A no symmetry + # A^d1_d0 * A^d0_d1 + # T_c = A^d0_d1 * A^d1_d0 + Lorentz = TensorIndexType('Lorentz', dummy_name='L', metric_symmetry=0) + d0, d1, d2, d3 = tensor_indices('d:4', Lorentz) + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.no_symmetry(2)) + t = A(d1, -d0)*A(d0, -d1) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, -L_1)*A(L_1, -L_0)' + + # A^d1_d2 * A^d0_d3 * A^d2_d1 * A^d3_d0 + # T_c = A^d0_d1 * A^d1_d0 * A^d2_d3 * A^d3_d2 + t = A(d1, -d2)*A(d0, -d3)*A(d2, -d1)*A(d3, -d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, -L_1)*A(L_1, -L_0)*A(L_2, -L_3)*A(L_3, -L_2)' + + # A^d0_d2 * A^d1_d3 * A^d3_d0 * A^d2_d1 + # T_c = A^d0_d1 * A^d1_d2 * A^d2_d3 * A^d3_d0 + t = A(d0, -d1)*A(d1, -d2)*A(d2, -d3)*A(d3, -d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, -L_1)*A(L_1, -L_2)*A(L_2, -L_3)*A(L_3, -L_0)' + +def test_canonicalize1(): + Lorentz = TensorIndexType('Lorentz', dummy_name='L') + a, a0, a1, a2, a3, b, d0, d1, d2, d3 = \ + tensor_indices('a,a0,a1,a2,a3,b,d0,d1,d2,d3', Lorentz) + + # A_d0*A^d0; ord = [d0,-d0] + # T_c = A^d0*A_d0 + A = TensorHead('A', [Lorentz], TensorSymmetry.no_symmetry(1)) + t = A(-d0)*A(d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0)*A(-L_0)' + + # A commuting + # A_d0*A_d1*A_d2*A^d2*A^d1*A^d0 + # T_c = A^d0*A_d0*A^d1*A_d1*A^d2*A_d2 + t = A(-d0)*A(-d1)*A(-d2)*A(d2)*A(d1)*A(d0) + tc = t.canon_bp() + assert str(tc) == 'A(L_0)*A(-L_0)*A(L_1)*A(-L_1)*A(L_2)*A(-L_2)' + + # A anticommuting + # A_d0*A_d1*A_d2*A^d2*A^d1*A^d0 + # T_c 0 + A = TensorHead('A', [Lorentz], TensorSymmetry.no_symmetry(1), 1) + t = A(-d0)*A(-d1)*A(-d2)*A(d2)*A(d1)*A(d0) + tc = t.canon_bp() + assert tc == 0 + + # A commuting symmetric + # A^{d0 b}*A^a_d1*A^d1_d0 + # T_c = A^{a d0}*A^{b d1}*A_{d0 d1} + A = TensorHead('A', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + t = A(d0, b)*A(a, -d1)*A(d1, -d0) + tc = t.canon_bp() + assert str(tc) == 'A(a, L_0)*A(b, L_1)*A(-L_0, -L_1)' + + # A, B commuting symmetric + # A^{d0 b}*A^d1_d0*B^a_d1 + # T_c = A^{b d0}*A_d0^d1*B^a_d1 + B = TensorHead('B', [Lorentz]*2, TensorSymmetry.fully_symmetric(2)) + t = A(d0, b)*A(d1, -d0)*B(a, -d1) + tc = t.canon_bp() + assert str(tc) == 'A(b, L_0)*A(-L_0, L_1)*B(a, -L_1)' + + # A commuting symmetric + # A^{d1 d0 b}*A^{a}_{d1 d0}; ord=[a,b, d0,-d0,d1,-d1] + # T_c = A^{a d0 d1}*A^{b}_{d0 d1} + A = TensorHead('A', [Lorentz]*3, TensorSymmetry.fully_symmetric(3)) + t = A(d1, d0, b)*A(a, -d1, -d0) + tc = t.canon_bp() + assert str(tc) == 'A(a, L_0, L_1)*A(b, -L_0, -L_1)' + + # A^{d3 d0 d2}*A^a0_{d1 d2}*A^d1_d3^a1*A^{a2 a3}_d0 + # T_c = A^{a0 d0 d1}*A^a1_d0^d2*A^{a2 a3 d3}*A_{d1 d2 d3} + t = A(d3, d0, d2)*A(a0, -d1, -d2)*A(d1, -d3, a1)*A(a2, a3, -d0) + tc = t.canon_bp() + assert str(tc) == 'A(a0, L_0, L_1)*A(a1, -L_0, L_2)*A(a2, a3, L_3)*A(-L_1, -L_2, -L_3)' + + # A commuting symmetric, B antisymmetric + # A^{d0 d1 d2} * A_{d2 d3 d1} * B_d0^d3 + # in this esxample and in the next three, + # renaming dummy indices and using symmetry of A, + # T = A^{d0 d1 d2} * A_{d0 d1 d3} * B_d2^d3 + # can = 0 + A = TensorHead('A', [Lorentz]*3, TensorSymmetry.fully_symmetric(3)) + B = TensorHead('B', [Lorentz]*2, TensorSymmetry.fully_symmetric(-2)) + t = A(d0, d1, d2)*A(-d2, -d3, -d1)*B(-d0, d3) + tc = t.canon_bp() + assert tc == 0 + + # A anticommuting symmetric, B antisymmetric + # A^{d0 d1 d2} * A_{d2 d3 d1} * B_d0^d3 + # T_c = A^{d0 d1 d2} * A_{d0 d1}^d3 * B_{d2 d3} + A = TensorHead('A', [Lorentz]*3, TensorSymmetry.fully_symmetric(3), 1) + B = TensorHead('B', [Lorentz]*2, TensorSymmetry.fully_symmetric(-2)) + t = A(d0, d1, d2)*A(-d2, -d3, -d1)*B(-d0, d3) + tc = t.canon_bp() + assert str(tc) == 'A(L_0, L_1, L_2)*A(-L_0, -L_1, L_3)*B(-L_2, -L_3)' + + # A anticommuting symmetric, B antisymmetric commuting, antisymmetric metric + # A^{d0 d1 d2} * A_{d2 d3 d1} * B_d0^d3 + # T_c = -A^{d0 d1 d2} * A_{d0 d1}^d3 * B_{d2 d3} + Spinor = TensorIndexType('Spinor', dummy_name='S', metric_symmetry=-1) + a, a0, a1, a2, a3, b, d0, d1, d2, d3 = \ + tensor_indices('a,a0,a1,a2,a3,b,d0,d1,d2,d3', Spinor) + A = TensorHead('A', [Spinor]*3, TensorSymmetry.fully_symmetric(3), 1) + B = TensorHead('B', [Spinor]*2, TensorSymmetry.fully_symmetric(-2)) + t = A(d0, d1, d2)*A(-d2, -d3, -d1)*B(-d0, d3) + tc = t.canon_bp() + assert str(tc) == '-A(S_0, S_1, S_2)*A(-S_0, -S_1, S_3)*B(-S_2, -S_3)' + + # A anticommuting symmetric, B antisymmetric anticommuting, + # no metric symmetry + # A^{d0 d1 d2} * A_{d2 d3 d1} * B_d0^d3 + # T_c = A^{d0 d1 d2} * A_{d0 d1 d3} * B_d2^d3 + Mat = TensorIndexType('Mat', metric_symmetry=0, dummy_name='M') + a, a0, a1, a2, a3, b, d0, d1, d2, d3 = \ + tensor_indices('a,a0,a1,a2,a3,b,d0,d1,d2,d3', Mat) + A = TensorHead('A', [Mat]*3, TensorSymmetry.fully_symmetric(3), 1) + B = TensorHead('B', [Mat]*2, TensorSymmetry.fully_symmetric(-2)) + t = A(d0, d1, d2)*A(-d2, -d3, -d1)*B(-d0, d3) + tc = t.canon_bp() + assert str(tc) == 'A(M_0, M_1, M_2)*A(-M_0, -M_1, -M_3)*B(-M_2, M_3)' + + # Gamma anticommuting + # Gamma_{mu nu} * gamma^rho * Gamma^{nu mu alpha} + # T_c = -Gamma^{mu nu} * gamma^rho * Gamma_{alpha mu nu} + alpha, beta, gamma, mu, nu, rho = \ + tensor_indices('alpha,beta,gamma,mu,nu,rho', Lorentz) + Gamma = TensorHead('Gamma', [Lorentz], + TensorSymmetry.fully_symmetric(1), 2) + Gamma2 = TensorHead('Gamma', [Lorentz]*2, + TensorSymmetry.fully_symmetric(-2), 2) + Gamma3 = TensorHead('Gamma', [Lorentz]*3, + TensorSymmetry.fully_symmetric(-3), 2) + t = Gamma2(-mu, -nu)*Gamma(rho)*Gamma3(nu, mu, alpha) + tc = t.canon_bp() + assert str(tc) == '-Gamma(L_0, L_1)*Gamma(rho)*Gamma(alpha, -L_0, -L_1)' + + # Gamma_{mu nu} * Gamma^{gamma beta} * gamma_rho * Gamma^{nu mu alpha} + # T_c = Gamma^{mu nu} * Gamma^{beta gamma} * gamma_rho * Gamma^alpha_{mu nu} + t = Gamma2(mu, nu)*Gamma2(beta, gamma)*Gamma(-rho)*Gamma3(alpha, -mu, -nu) + tc = t.canon_bp() + assert str(tc) == 'Gamma(L_0, L_1)*Gamma(beta, gamma)*Gamma(-rho)*Gamma(alpha, -L_0, -L_1)' + + # f^a_{b,c} antisymmetric in b,c; A_mu^a no symmetry + # f^c_{d a} * f_{c e b} * A_mu^d * A_nu^a * A^{nu e} * A^{mu b} + # g = [8,11,5, 9,13,7, 1,10, 3,4, 2,12, 0,6, 14,15] + # T_c = -f^{a b c} * f_a^{d e} * A^mu_b * A_{mu d} * A^nu_c * A_{nu e} + Flavor = TensorIndexType('Flavor', dummy_name='F') + a, b, c, d, e, ff = tensor_indices('a,b,c,d,e,f', Flavor) + mu, nu = tensor_indices('mu,nu', Lorentz) + f = TensorHead('f', [Flavor]*3, TensorSymmetry.direct_product(1, -2)) + A = TensorHead('A', [Lorentz, Flavor], TensorSymmetry.no_symmetry(2)) + t = f(c, -d, -a)*f(-c, -e, -b)*A(-mu, d)*A(-nu, a)*A(nu, e)*A(mu, b) + tc = t.canon_bp() + assert str(tc) == '-f(F_0, F_1, F_2)*f(-F_0, F_3, F_4)*A(L_0, -F_1)*A(-L_0, -F_3)*A(L_1, -F_2)*A(-L_1, -F_4)' + + +def test_bug_correction_tensor_indices(): + # to make sure that tensor_indices does not return a list if creating + # only one index: + A = TensorIndexType("A") + i = tensor_indices('i', A) + assert not isinstance(i, (tuple, list)) + assert isinstance(i, TensorIndex) + + +def test_riemann_invariants(): + Lorentz = TensorIndexType('Lorentz', dummy_name='L') + d0, d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11 = \ + tensor_indices('d0:12', Lorentz) + # R^{d0 d1}_{d1 d0}; ord = [d0,-d0,d1,-d1] + # T_c = -R^{d0 d1}_{d0 d1} + R = TensorHead('R', [Lorentz]*4, TensorSymmetry.riemann()) + t = R(d0, d1, -d1, -d0) + tc = t.canon_bp() + assert str(tc) == '-R(L_0, L_1, -L_0, -L_1)' + + # R_d11^d1_d0^d5 * R^{d6 d4 d0}_d5 * R_{d7 d2 d8 d9} * + # R_{d10 d3 d6 d4} * R^{d2 d7 d11}_d1 * R^{d8 d9 d3 d10} + # can = [0,2,4,6, 1,3,8,10, 5,7,12,14, 9,11,16,18, 13,15,20,22, + # 17,19,21>> from sympy.tensor.tensor import TensorIndexType, TensorHead + >>> from sympy.tensor.toperators import PartialDerivative + >>> from sympy import symbols + >>> L = TensorIndexType("L") + >>> A = TensorHead("A", [L]) + >>> B = TensorHead("B", [L]) + >>> i, j, k = symbols("i j k") + + >>> expr = PartialDerivative(A(i), A(j)) + >>> expr + PartialDerivative(A(i), A(j)) + + The ``PartialDerivative`` object behaves like a tensorial expression: + + >>> expr.get_indices() + [i, -j] + + Notice that the deriving variables have opposite valence than the + printed one: ``A(j)`` is printed as covariant, but the index of the + derivative is actually contravariant, i.e. ``-j``. + + Indices can be contracted: + + >>> expr = PartialDerivative(A(i), A(i)) + >>> expr + PartialDerivative(A(L_0), A(L_0)) + >>> expr.get_indices() + [L_0, -L_0] + + The method ``.get_indices()`` always returns all indices (even the + contracted ones). If only uncontracted indices are needed, call + ``.get_free_indices()``: + + >>> expr.get_free_indices() + [] + + Nested partial derivatives are flattened: + + >>> expr = PartialDerivative(PartialDerivative(A(i), A(j)), A(k)) + >>> expr + PartialDerivative(A(i), A(j), A(k)) + >>> expr.get_indices() + [i, -j, -k] + + Replace a derivative with array values: + + >>> from sympy.abc import x, y + >>> from sympy import sin, log + >>> compA = [sin(x), log(x)*y**3] + >>> compB = [x, y] + >>> expr = PartialDerivative(A(i), B(j)) + >>> expr.replace_with_arrays({A(i): compA, B(i): compB}) + [[cos(x), 0], [y**3/x, 3*y**2*log(x)]] + + The returned array is indexed by `(i, -j)`. + + Be careful that other SymPy modules put the indices of the deriving + variables before the indices of the derivand in the derivative result. + For example: + + >>> expr.get_free_indices() + [i, -j] + + >>> from sympy import Matrix, Array + >>> Matrix(compA).diff(Matrix(compB)).reshape(2, 2) + [[cos(x), y**3/x], [0, 3*y**2*log(x)]] + >>> Array(compA).diff(Array(compB)) + [[cos(x), y**3/x], [0, 3*y**2*log(x)]] + + These are the transpose of the result of ``PartialDerivative``, + as the matrix and the array modules put the index `-j` before `i` in the + derivative result. An array read with index order `(-j, i)` is indeed the + transpose of the same array read with index order `(i, -j)`. By specifying + the index order to ``.replace_with_arrays`` one can get a compatible + expression: + + >>> expr.replace_with_arrays({A(i): compA, B(i): compB}, [-j, i]) + [[cos(x), y**3/x], [0, 3*y**2*log(x)]] + """ + + def __new__(cls, expr, *variables): + + # Flatten: + if isinstance(expr, PartialDerivative): + variables = expr.variables + variables + expr = expr.expr + + args, indices, free, dum = cls._contract_indices_for_derivative( + S(expr), variables) + + obj = TensExpr.__new__(cls, *args) + + obj._indices = indices + obj._free = free + obj._dum = dum + return obj + + @property + def coeff(self): + return S.One + + @property + def nocoeff(self): + return self + + @classmethod + def _contract_indices_for_derivative(cls, expr, variables): + variables_opposite_valence = [] + + for i in variables: + if isinstance(i, Tensor): + i_free_indices = i.get_free_indices() + variables_opposite_valence.append( + i.xreplace({k: -k for k in i_free_indices})) + elif isinstance(i, Symbol): + variables_opposite_valence.append(i) + + args, indices, free, dum = TensMul._tensMul_contract_indices( + [expr] + variables_opposite_valence, replace_indices=True) + + for i in range(1, len(args)): + args_i = args[i] + if isinstance(args_i, Tensor): + i_indices = args[i].get_free_indices() + args[i] = args[i].xreplace({k: -k for k in i_indices}) + + return args, indices, free, dum + + def doit(self, **hints): + args, indices, free, dum = self._contract_indices_for_derivative(self.expr, self.variables) + + obj = self.func(*args) + obj._indices = indices + obj._free = free + obj._dum = dum + + return obj + + def _expand_partial_derivative(self): + args, indices, free, dum = self._contract_indices_for_derivative(self.expr, self.variables) + + obj = self.func(*args) + obj._indices = indices + obj._free = free + obj._dum = dum + + result = obj + + if not args[0].free_symbols: + return S.Zero + elif isinstance(obj.expr, TensAdd): + # take care of sums of multi PDs + result = obj.expr.func(*[ + self.func(a, *obj.variables)._expand_partial_derivative() + for a in result.expr.args]) + elif isinstance(obj.expr, TensMul): + # take care of products of multi PDs + if len(obj.variables) == 1: + # derivative with respect to single variable + terms = [] + mulargs = list(obj.expr.args) + for ind in range(len(mulargs)): + if not isinstance(sympify(mulargs[ind]), Number): + # a number coefficient is not considered for + # expansion of PartialDerivative + d = self.func(mulargs[ind], *obj.variables)._expand_partial_derivative() + terms.append(TensMul(*(mulargs[:ind] + + [d] + + mulargs[(ind + 1):]))) + result = TensAdd.fromiter(terms) + else: + # derivative with respect to multiple variables + # decompose: + # partial(expr, (u, v)) + # = partial(partial(expr, u).doit(), v).doit() + result = obj.expr # init with expr + for v in obj.variables: + result = self.func(result, v)._expand_partial_derivative() + # then throw PD on it + + return result + + def _perform_derivative(self): + result = self.expr + for v in self.variables: + if isinstance(result, TensExpr): + result = result._eval_partial_derivative(v) + else: + if v._diff_wrt: + result = result._eval_derivative(v) + else: + result = S.Zero + return result + + def get_indices(self): + return self._indices + + def get_free_indices(self): + free = sorted(self._free, key=lambda x: x[1]) + return [i[0] for i in free] + + def _replace_indices(self, repl): + expr = self.expr.xreplace(repl) + mirrored = {-k: -v for k, v in repl.items()} + variables = [i.xreplace(mirrored) for i in self.variables] + return self.func(expr, *variables) + + @property + def expr(self): + return self.args[0] + + @property + def variables(self): + return self.args[1:] + + def _extract_data(self, replacement_dict): + from .array import derive_by_array, tensorcontraction + indices, array = self.expr._extract_data(replacement_dict) + for variable in self.variables: + var_indices, var_array = variable._extract_data(replacement_dict) + var_indices = [-i for i in var_indices] + coeff_array, var_array = zip(*[i.as_coeff_Mul() for i in var_array]) + dim_before = len(array.shape) + array = derive_by_array(array, var_array) + dim_after = len(array.shape) + dim_increase = dim_after - dim_before + array = permutedims(array, [i + dim_increase for i in range(dim_before)] + list(range(dim_increase))) + array = array.as_mutable() + varindex = var_indices[0] + # Remove coefficients of base vector: + coeff_index = [0] + [slice(None) for i in range(len(indices))] + for i, coeff in enumerate(coeff_array): + coeff_index[0] = i + array[tuple(coeff_index)] /= coeff + if -varindex in indices: + pos = indices.index(-varindex) + array = tensorcontraction(array, (0, pos+1)) + indices.pop(pos) + else: + indices.append(varindex) + return indices, array diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..aa66402955e7d5d2b27cccc6627b42d33f4cd855 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/__init__.py @@ -0,0 +1,10 @@ +"""This module contains code for running the tests in SymPy.""" + + +from .runtests import doctest +from .runtests_pytest import test + + +__all__ = [ + 'test', 'doctest', +] diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/matrices.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/matrices.py new file mode 100644 index 0000000000000000000000000000000000000000..236a384366df7f69d0d92f43f7e007e95c12388c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/matrices.py @@ -0,0 +1,8 @@ +def allclose(A, B, rtol=1e-05, atol=1e-08): + if len(A) != len(B): + return False + + for x, y in zip(A, B): + if abs(x-y) > atol + rtol * max(abs(x), abs(y)): + return False + return True diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/pytest.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/pytest.py new file mode 100644 index 0000000000000000000000000000000000000000..498515a2d3c0a167a5f7067753736898cfa64799 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/pytest.py @@ -0,0 +1,392 @@ +"""py.test hacks to support XFAIL/XPASS""" + +import platform +import sys +import re +import functools +import os +import contextlib +import warnings +import inspect +import pathlib +from typing import Any, Callable + +from sympy.utilities.exceptions import SymPyDeprecationWarning +# Imported here for backwards compatibility. Note: do not import this from +# here in library code (importing sympy.pytest in library code will break the +# pytest integration). +from sympy.utilities.exceptions import ignore_warnings # noqa:F401 + +ON_CI = os.getenv('CI', None) == "true" + +try: + import pytest + USE_PYTEST = getattr(sys, '_running_pytest', False) +except ImportError: + USE_PYTEST = False + +IS_WASM: bool = sys.platform == 'emscripten' or platform.machine() in ["wasm32", "wasm64"] + +raises: Callable[[Any, Any], Any] +XFAIL: Callable[[Any], Any] +skip: Callable[[Any], Any] +SKIP: Callable[[Any], Any] +slow: Callable[[Any], Any] +tooslow: Callable[[Any], Any] +nocache_fail: Callable[[Any], Any] + + +if USE_PYTEST: + raises = pytest.raises + skip = pytest.skip + XFAIL = pytest.mark.xfail + SKIP = pytest.mark.skip + slow = pytest.mark.slow + tooslow = pytest.mark.tooslow + nocache_fail = pytest.mark.nocache_fail + from _pytest.outcomes import Failed + +else: + # Not using pytest so define the things that would have been imported from + # there. + + # _pytest._code.code.ExceptionInfo + class ExceptionInfo: + def __init__(self, value): + self.value = value + + def __repr__(self): + return "".format(self.value) + + + def raises(expectedException, code=None): + """ + Tests that ``code`` raises the exception ``expectedException``. + + ``code`` may be a callable, such as a lambda expression or function + name. + + If ``code`` is not given or None, ``raises`` will return a context + manager for use in ``with`` statements; the code to execute then + comes from the scope of the ``with``. + + ``raises()`` does nothing if the callable raises the expected exception, + otherwise it raises an AssertionError. + + Examples + ======== + + >>> from sympy.testing.pytest import raises + + >>> raises(ZeroDivisionError, lambda: 1/0) + + >>> raises(ZeroDivisionError, lambda: 1/2) + Traceback (most recent call last): + ... + Failed: DID NOT RAISE + + >>> with raises(ZeroDivisionError): + ... n = 1/0 + >>> with raises(ZeroDivisionError): + ... n = 1/2 + Traceback (most recent call last): + ... + Failed: DID NOT RAISE + + Note that you cannot test multiple statements via + ``with raises``: + + >>> with raises(ZeroDivisionError): + ... n = 1/0 # will execute and raise, aborting the ``with`` + ... n = 9999/0 # never executed + + This is just what ``with`` is supposed to do: abort the + contained statement sequence at the first exception and let + the context manager deal with the exception. + + To test multiple statements, you'll need a separate ``with`` + for each: + + >>> with raises(ZeroDivisionError): + ... n = 1/0 # will execute and raise + >>> with raises(ZeroDivisionError): + ... n = 9999/0 # will also execute and raise + + """ + if code is None: + return RaisesContext(expectedException) + elif callable(code): + try: + code() + except expectedException as e: + return ExceptionInfo(e) + raise Failed("DID NOT RAISE") + elif isinstance(code, str): + raise TypeError( + '\'raises(xxx, "code")\' has been phased out; ' + 'change \'raises(xxx, "expression")\' ' + 'to \'raises(xxx, lambda: expression)\', ' + '\'raises(xxx, "statement")\' ' + 'to \'with raises(xxx): statement\'') + else: + raise TypeError( + 'raises() expects a callable for the 2nd argument.') + + class RaisesContext: + def __init__(self, expectedException): + self.expectedException = expectedException + + def __enter__(self): + return None + + def __exit__(self, exc_type, exc_value, traceback): + if exc_type is None: + raise Failed("DID NOT RAISE") + return issubclass(exc_type, self.expectedException) + + class XFail(Exception): + pass + + class XPass(Exception): + pass + + class Skipped(Exception): + pass + + class Failed(Exception): # type: ignore + pass + + def XFAIL(func): + def wrapper(): + try: + func() + except Exception as e: + message = str(e) + if message != "Timeout": + raise XFail(func.__name__) + else: + raise Skipped("Timeout") + raise XPass(func.__name__) + + wrapper = functools.update_wrapper(wrapper, func) + return wrapper + + def skip(str): + raise Skipped(str) + + def SKIP(reason): + """Similar to ``skip()``, but this is a decorator. """ + def wrapper(func): + def func_wrapper(): + raise Skipped(reason) + + func_wrapper = functools.update_wrapper(func_wrapper, func) + return func_wrapper + + return wrapper + + def slow(func): + func._slow = True + + def func_wrapper(): + func() + + func_wrapper = functools.update_wrapper(func_wrapper, func) + func_wrapper.__wrapped__ = func + return func_wrapper + + def tooslow(func): + func._slow = True + func._tooslow = True + + def func_wrapper(): + skip("Too slow") + + func_wrapper = functools.update_wrapper(func_wrapper, func) + func_wrapper.__wrapped__ = func + return func_wrapper + + def nocache_fail(func): + "Dummy decorator for marking tests that fail when cache is disabled" + return func + +@contextlib.contextmanager +def warns(warningcls, *, match='', test_stacklevel=True): + ''' + Like raises but tests that warnings are emitted. + + >>> from sympy.testing.pytest import warns + >>> import warnings + + >>> with warns(UserWarning): + ... warnings.warn('deprecated', UserWarning, stacklevel=2) + + >>> with warns(UserWarning): + ... pass + Traceback (most recent call last): + ... + Failed: DID NOT WARN. No warnings of type UserWarning\ + was emitted. The list of emitted warnings is: []. + + ``test_stacklevel`` makes it check that the ``stacklevel`` parameter to + ``warn()`` is set so that the warning shows the user line of code (the + code under the warns() context manager). Set this to False if this is + ambiguous or if the context manager does not test the direct user code + that emits the warning. + + If the warning is a ``SymPyDeprecationWarning``, this additionally tests + that the ``active_deprecations_target`` is a real target in the + ``active-deprecations.md`` file. + + ''' + # Absorbs all warnings in warnrec + with warnings.catch_warnings(record=True) as warnrec: + # Any warning other than the one we are looking for is an error + warnings.simplefilter("error") + warnings.filterwarnings("always", category=warningcls) + # Now run the test + yield warnrec + + # Raise if expected warning not found + if not any(issubclass(w.category, warningcls) for w in warnrec): + msg = ('Failed: DID NOT WARN.' + ' No warnings of type %s was emitted.' + ' The list of emitted warnings is: %s.' + ) % (warningcls, [w.message for w in warnrec]) + raise Failed(msg) + + # We don't include the match in the filter above because it would then + # fall to the error filter, so we instead manually check that it matches + # here + for w in warnrec: + # Should always be true due to the filters above + assert issubclass(w.category, warningcls) + if not re.compile(match, re.IGNORECASE).match(str(w.message)): + raise Failed(f"Failed: WRONG MESSAGE. A warning with of the correct category ({warningcls.__name__}) was issued, but it did not match the given match regex ({match!r})") + + if test_stacklevel: + for f in inspect.stack(): + thisfile = f.filename + file = os.path.split(thisfile)[1] + if file.startswith('test_'): + break + elif file == 'doctest.py': + # skip the stacklevel testing in the doctests of this + # function + return + else: + raise RuntimeError("Could not find the file for the given warning to test the stacklevel") + for w in warnrec: + if w.filename != thisfile: + msg = f'''\ +Failed: Warning has the wrong stacklevel. The warning stacklevel needs to be +set so that the line of code shown in the warning message is user code that +calls the deprecated code (the current stacklevel is showing code from +{w.filename} (line {w.lineno}), expected {thisfile})'''.replace('\n', ' ') + raise Failed(msg) + + if warningcls == SymPyDeprecationWarning: + this_file = pathlib.Path(__file__) + active_deprecations_file = (this_file.parent.parent.parent / 'doc' / + 'src' / 'explanation' / + 'active-deprecations.md') + if not active_deprecations_file.exists(): + # We can only test that the active_deprecations_target works if we are + # in the git repo. + return + targets = [] + for w in warnrec: + targets.append(w.message.active_deprecations_target) + text = pathlib.Path(active_deprecations_file).read_text(encoding="utf-8") + for target in targets: + if f'({target})=' not in text: + raise Failed(f"The active deprecations target {target!r} does not appear to be a valid target in the active-deprecations.md file ({active_deprecations_file}).") + +def _both_exp_pow(func): + """ + Decorator used to run the test twice: the first time `e^x` is represented + as ``Pow(E, x)``, the second time as ``exp(x)`` (exponential object is not + a power). + + This is a temporary trick helping to manage the elimination of the class + ``exp`` in favor of a replacement by ``Pow(E, ...)``. + """ + from sympy.core.parameters import _exp_is_pow + + def func_wrap(): + with _exp_is_pow(True): + func() + with _exp_is_pow(False): + func() + + wrapper = functools.update_wrapper(func_wrap, func) + return wrapper + + +@contextlib.contextmanager +def warns_deprecated_sympy(): + ''' + Shorthand for ``warns(SymPyDeprecationWarning)`` + + This is the recommended way to test that ``SymPyDeprecationWarning`` is + emitted for deprecated features in SymPy. To test for other warnings use + ``warns``. To suppress warnings without asserting that they are emitted + use ``ignore_warnings``. + + .. note:: + + ``warns_deprecated_sympy()`` is only intended for internal use in the + SymPy test suite to test that a deprecation warning triggers properly. + All other code in the SymPy codebase, including documentation examples, + should not use deprecated behavior. + + If you are a user of SymPy and you want to disable + SymPyDeprecationWarnings, use ``warnings`` filters (see + :ref:`silencing-sympy-deprecation-warnings`). + + >>> from sympy.testing.pytest import warns_deprecated_sympy + >>> from sympy.utilities.exceptions import sympy_deprecation_warning + >>> with warns_deprecated_sympy(): + ... sympy_deprecation_warning("Don't use", + ... deprecated_since_version="1.0", + ... active_deprecations_target="active-deprecations") + + >>> with warns_deprecated_sympy(): + ... pass + Traceback (most recent call last): + ... + Failed: DID NOT WARN. No warnings of type \ + SymPyDeprecationWarning was emitted. The list of emitted warnings is: []. + + .. note:: + + Sometimes the stacklevel test will fail because the same warning is + emitted multiple times. In this case, you can use + :func:`sympy.utilities.exceptions.ignore_warnings` in the code to + prevent the ``SymPyDeprecationWarning`` from being emitted again + recursively. In rare cases it is impossible to have a consistent + ``stacklevel`` for deprecation warnings because different ways of + calling a function will produce different call stacks.. In those cases, + use ``warns(SymPyDeprecationWarning)`` instead. + + See Also + ======== + sympy.utilities.exceptions.SymPyDeprecationWarning + sympy.utilities.exceptions.sympy_deprecation_warning + sympy.utilities.decorator.deprecated + + ''' + with warns(SymPyDeprecationWarning): + yield + + +def skip_under_pyodide(message): + """Decorator to skip a test if running under Pyodide/WASM.""" + def decorator(test_func): + @functools.wraps(test_func) + def test_wrapper(): + if IS_WASM: + skip(message) + return test_func() + return test_wrapper + return decorator diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/quality_unicode.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/quality_unicode.py new file mode 100644 index 0000000000000000000000000000000000000000..d43623ff5112610e377347f50c6a40a15810644b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/quality_unicode.py @@ -0,0 +1,102 @@ +import re +import fnmatch + + +message_unicode_B = \ + "File contains a unicode character : %s, line %s. " \ + "But not in the whitelist. " \ + "Add the file to the whitelist in " + __file__ +message_unicode_D = \ + "File does not contain a unicode character : %s." \ + "but is in the whitelist. " \ + "Remove the file from the whitelist in " + __file__ + + +encoding_header_re = re.compile( + r'^[ \t\f]*#.*?coding[:=][ \t]*([-_.a-zA-Z0-9]+)') + +# Whitelist pattern for files which can have unicode. +unicode_whitelist = [ + # Author names can include non-ASCII characters + r'*/bin/authors_update.py', + r'*/bin/mailmap_check.py', + + # These files have functions and test functions for unicode input and + # output. + r'*/sympy/testing/tests/test_code_quality.py', + r'*/sympy/physics/vector/tests/test_printing.py', + r'*/physics/quantum/tests/test_printing.py', + r'*/sympy/vector/tests/test_printing.py', + r'*/sympy/parsing/tests/test_sympy_parser.py', + r'*/sympy/printing/pretty/stringpict.py', + r'*/sympy/printing/pretty/tests/test_pretty.py', + r'*/sympy/printing/tests/test_conventions.py', + r'*/sympy/printing/tests/test_preview.py', + r'*/liealgebras/type_g.py', + r'*/liealgebras/weyl_group.py', + r'*/liealgebras/tests/test_type_G.py', + + # wigner.py and polarization.py have unicode doctests. These probably + # don't need to be there but some of the examples that are there are + # pretty ugly without use_unicode (matrices need to be wrapped across + # multiple lines etc) + r'*/sympy/physics/wigner.py', + r'*/sympy/physics/optics/polarization.py', + + # joint.py uses some unicode for variable names in the docstrings + r'*/sympy/physics/mechanics/joint.py', + + # lll method has unicode in docstring references and author name + r'*/sympy/polys/matrices/domainmatrix.py', + r'*/sympy/matrices/repmatrix.py', + + # Explanation of symbols uses greek letters + r'*/sympy/core/symbol.py', +] + +unicode_strict_whitelist = [ + r'*/sympy/parsing/latex/_antlr/__init__.py', + # test_mathematica.py uses some unicode for testing Greek characters are working #24055 + r'*/sympy/parsing/tests/test_mathematica.py', +] + + +def _test_this_file_encoding( + fname, test_file, + unicode_whitelist=unicode_whitelist, + unicode_strict_whitelist=unicode_strict_whitelist): + """Test helper function for unicode test + + The test may have to operate on filewise manner, so it had moved + to a separate process. + """ + has_unicode = False + + is_in_whitelist = False + is_in_strict_whitelist = False + for patt in unicode_whitelist: + if fnmatch.fnmatch(fname, patt): + is_in_whitelist = True + break + for patt in unicode_strict_whitelist: + if fnmatch.fnmatch(fname, patt): + is_in_strict_whitelist = True + is_in_whitelist = True + break + + if is_in_whitelist: + for idx, line in enumerate(test_file): + try: + line.encode(encoding='ascii') + except (UnicodeEncodeError, UnicodeDecodeError): + has_unicode = True + + if not has_unicode and not is_in_strict_whitelist: + assert False, message_unicode_D % fname + + else: + for idx, line in enumerate(test_file): + try: + line.encode(encoding='ascii') + except (UnicodeEncodeError, UnicodeDecodeError): + assert False, message_unicode_B % (fname, idx + 1) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/randtest.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/randtest.py new file mode 100644 index 0000000000000000000000000000000000000000..3ce2c8c031eec1c886532daba32c96d83e9cf85c --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/randtest.py @@ -0,0 +1,19 @@ +""" +.. deprecated:: 1.10 + + ``sympy.testing.randtest`` functions have been moved to + :mod:`sympy.core.random`. + +""" +from sympy.utilities.exceptions import sympy_deprecation_warning + +sympy_deprecation_warning("The sympy.testing.randtest submodule is deprecated. Use sympy.core.random instead.", + deprecated_since_version="1.10", + active_deprecations_target="deprecated-sympy-testing-randtest") + +from sympy.core.random import ( # noqa:F401 + random_complex_number, + verify_numerically, + test_derivative_numerically, + _randrange, + _randint) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/runtests.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/runtests.py new file mode 100644 index 0000000000000000000000000000000000000000..e2650e4e6dabaaa07fc25c76cce3d9d28723b0d5 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/runtests.py @@ -0,0 +1,2409 @@ +""" +This is our testing framework. + +Goals: + +* it should be compatible with py.test and operate very similarly + (or identically) +* does not require any external dependencies +* preferably all the functionality should be in this file only +* no magic, just import the test file and execute the test functions, that's it +* portable + +""" + +import os +import sys +import platform +import inspect +import traceback +import pdb +import re +import linecache +import time +from fnmatch import fnmatch +from timeit import default_timer as clock +import doctest as pdoctest # avoid clashing with our doctest() function +from doctest import DocTestFinder, DocTestRunner +import random +import subprocess +import shutil +import signal +import stat +import tempfile +import warnings +from contextlib import contextmanager +from inspect import unwrap +from pathlib import Path + +from sympy.core.cache import clear_cache +from sympy.external import import_module +from sympy.external.gmpy import GROUND_TYPES + +IS_WINDOWS = (os.name == 'nt') +ON_CI = os.getenv('CI', None) + +# empirically generated list of the proportion of time spent running +# an even split of tests. This should periodically be regenerated. +# A list of [.6, .1, .3] would mean that if the tests are evenly split +# into '1/3', '2/3', '3/3', the first split would take 60% of the time, +# the second 10% and the third 30%. These lists are normalized to sum +# to 1, so [60, 10, 30] has the same behavior as [6, 1, 3] or [.6, .1, .3]. +# +# This list can be generated with the code: +# from time import time +# import sympy +# import os +# os.environ["CI"] = 'true' # Mock CI to get more correct densities +# delays, num_splits = [], 30 +# for i in range(1, num_splits + 1): +# tic = time() +# sympy.test(split='{}/{}'.format(i, num_splits), time_balance=False) # Add slow=True for slow tests +# delays.append(time() - tic) +# tot = sum(delays) +# print([round(x / tot, 4) for x in delays]) +SPLIT_DENSITY = [ + 0.0059, 0.0027, 0.0068, 0.0011, 0.0006, + 0.0058, 0.0047, 0.0046, 0.004, 0.0257, + 0.0017, 0.0026, 0.004, 0.0032, 0.0016, + 0.0015, 0.0004, 0.0011, 0.0016, 0.0014, + 0.0077, 0.0137, 0.0217, 0.0074, 0.0043, + 0.0067, 0.0236, 0.0004, 0.1189, 0.0142, + 0.0234, 0.0003, 0.0003, 0.0047, 0.0006, + 0.0013, 0.0004, 0.0008, 0.0007, 0.0006, + 0.0139, 0.0013, 0.0007, 0.0051, 0.002, + 0.0004, 0.0005, 0.0213, 0.0048, 0.0016, + 0.0012, 0.0014, 0.0024, 0.0015, 0.0004, + 0.0005, 0.0007, 0.011, 0.0062, 0.0015, + 0.0021, 0.0049, 0.0006, 0.0006, 0.0011, + 0.0006, 0.0019, 0.003, 0.0044, 0.0054, + 0.0057, 0.0049, 0.0016, 0.0006, 0.0009, + 0.0006, 0.0012, 0.0006, 0.0149, 0.0532, + 0.0076, 0.0041, 0.0024, 0.0135, 0.0081, + 0.2209, 0.0459, 0.0438, 0.0488, 0.0137, + 0.002, 0.0003, 0.0008, 0.0039, 0.0024, + 0.0005, 0.0004, 0.003, 0.056, 0.0026] +SPLIT_DENSITY_SLOW = [0.0086, 0.0004, 0.0568, 0.0003, 0.0032, 0.0005, 0.0004, 0.0013, 0.0016, 0.0648, 0.0198, 0.1285, 0.098, 0.0005, 0.0064, 0.0003, 0.0004, 0.0026, 0.0007, 0.0051, 0.0089, 0.0024, 0.0033, 0.0057, 0.0005, 0.0003, 0.001, 0.0045, 0.0091, 0.0006, 0.0005, 0.0321, 0.0059, 0.1105, 0.216, 0.1489, 0.0004, 0.0003, 0.0006, 0.0483] + +class Skipped(Exception): + pass + +class TimeOutError(Exception): + pass + +class DependencyError(Exception): + pass + + +def _indent(s, indent=4): + """ + Add the given number of space characters to the beginning of + every non-blank line in ``s``, and return the result. + If the string ``s`` is Unicode, it is encoded using the stdout + encoding and the ``backslashreplace`` error handler. + """ + # This regexp matches the start of non-blank lines: + return re.sub('(?m)^(?!$)', indent*' ', s) + + +pdoctest._indent = _indent # type: ignore + +# override reporter to maintain windows and python3 + + +def _report_failure(self, out, test, example, got): + """ + Report that the given example failed. + """ + s = self._checker.output_difference(example, got, self.optionflags) + s = s.encode('raw_unicode_escape').decode('utf8', 'ignore') + out(self._failure_header(test, example) + s) + + +if IS_WINDOWS: + DocTestRunner.report_failure = _report_failure # type: ignore + + +def convert_to_native_paths(lst): + """ + Converts a list of '/' separated paths into a list of + native (os.sep separated) paths and converts to lowercase + if the system is case insensitive. + """ + newlst = [] + for rv in lst: + rv = os.path.join(*rv.split("/")) + # on windows the slash after the colon is dropped + if sys.platform == "win32": + pos = rv.find(':') + if pos != -1: + if rv[pos + 1] != '\\': + rv = rv[:pos + 1] + '\\' + rv[pos + 1:] + newlst.append(os.path.normcase(rv)) + return newlst + + +def get_sympy_dir(): + """ + Returns the root SymPy directory and set the global value + indicating whether the system is case sensitive or not. + """ + this_file = os.path.abspath(__file__) + sympy_dir = os.path.join(os.path.dirname(this_file), "..", "..") + sympy_dir = os.path.normpath(sympy_dir) + return os.path.normcase(sympy_dir) + + +def setup_pprint(disable_line_wrap=True): + from sympy.interactive.printing import init_printing + from sympy.printing.pretty.pretty import pprint_use_unicode + import sympy.interactive.printing as interactive_printing + from sympy.printing.pretty import stringpict + + # Prevent init_printing() in doctests from affecting other doctests + interactive_printing.NO_GLOBAL = True + + # force pprint to be in ascii mode in doctests + use_unicode_prev = pprint_use_unicode(False) + + # disable line wrapping for pprint() outputs + wrap_line_prev = stringpict._GLOBAL_WRAP_LINE + if disable_line_wrap: + stringpict._GLOBAL_WRAP_LINE = False + + # hook our nice, hash-stable strprinter + init_printing(pretty_print=False) + + return use_unicode_prev, wrap_line_prev + + +@contextmanager +def raise_on_deprecated(): + """Context manager to make DeprecationWarning raise an error + + This is to catch SymPyDeprecationWarning from library code while running + tests and doctests. It is important to use this context manager around + each individual test/doctest in case some tests modify the warning + filters. + """ + with warnings.catch_warnings(): + warnings.filterwarnings('error', '.*', DeprecationWarning, module='sympy.*') + yield + + +def run_in_subprocess_with_hash_randomization( + function, function_args=(), + function_kwargs=None, command=sys.executable, + module='sympy.testing.runtests', force=False): + """ + Run a function in a Python subprocess with hash randomization enabled. + + If hash randomization is not supported by the version of Python given, it + returns False. Otherwise, it returns the exit value of the command. The + function is passed to sys.exit(), so the return value of the function will + be the return value. + + The environment variable PYTHONHASHSEED is used to seed Python's hash + randomization. If it is set, this function will return False, because + starting a new subprocess is unnecessary in that case. If it is not set, + one is set at random, and the tests are run. Note that if this + environment variable is set when Python starts, hash randomization is + automatically enabled. To force a subprocess to be created even if + PYTHONHASHSEED is set, pass ``force=True``. This flag will not force a + subprocess in Python versions that do not support hash randomization (see + below), because those versions of Python do not support the ``-R`` flag. + + ``function`` should be a string name of a function that is importable from + the module ``module``, like "_test". The default for ``module`` is + "sympy.testing.runtests". ``function_args`` and ``function_kwargs`` + should be a repr-able tuple and dict, respectively. The default Python + command is sys.executable, which is the currently running Python command. + + This function is necessary because the seed for hash randomization must be + set by the environment variable before Python starts. Hence, in order to + use a predetermined seed for tests, we must start Python in a separate + subprocess. + + Hash randomization was added in the minor Python versions 2.6.8, 2.7.3, + 3.1.5, and 3.2.3, and is enabled by default in all Python versions after + and including 3.3.0. + + Examples + ======== + + >>> from sympy.testing.runtests import ( + ... run_in_subprocess_with_hash_randomization) + >>> # run the core tests in verbose mode + >>> run_in_subprocess_with_hash_randomization("_test", + ... function_args=("core",), + ... function_kwargs={'verbose': True}) # doctest: +SKIP + # Will return 0 if sys.executable supports hash randomization and tests + # pass, 1 if they fail, and False if it does not support hash + # randomization. + + """ + cwd = get_sympy_dir() + # Note, we must return False everywhere, not None, as subprocess.call will + # sometimes return None. + + # First check if the Python version supports hash randomization + # If it does not have this support, it won't recognize the -R flag + p = subprocess.Popen([command, "-RV"], stdout=subprocess.PIPE, + stderr=subprocess.STDOUT, cwd=cwd) + p.communicate() + if p.returncode != 0: + return False + + hash_seed = os.getenv("PYTHONHASHSEED") + if not hash_seed: + os.environ["PYTHONHASHSEED"] = str(random.randrange(2**32)) + else: + if not force: + return False + + function_kwargs = function_kwargs or {} + + # Now run the command + commandstring = ("import sys; from %s import %s;sys.exit(%s(*%s, **%s))" % + (module, function, function, repr(function_args), + repr(function_kwargs))) + + try: + p = subprocess.Popen([command, "-R", "-c", commandstring], cwd=cwd) + p.communicate() + except KeyboardInterrupt: + p.wait() + finally: + # Put the environment variable back, so that it reads correctly for + # the current Python process. + if hash_seed is None: + del os.environ["PYTHONHASHSEED"] + else: + os.environ["PYTHONHASHSEED"] = hash_seed + return p.returncode + + +def run_all_tests(test_args=(), test_kwargs=None, + doctest_args=(), doctest_kwargs=None, + examples_args=(), examples_kwargs=None): + """ + Run all tests. + + Right now, this runs the regular tests (bin/test), the doctests + (bin/doctest), and the examples (examples/all.py). + + This is what ``setup.py test`` uses. + + You can pass arguments and keyword arguments to the test functions that + support them (for now, test, doctest, and the examples). See the + docstrings of those functions for a description of the available options. + + For example, to run the solvers tests with colors turned off: + + >>> from sympy.testing.runtests import run_all_tests + >>> run_all_tests(test_args=("solvers",), + ... test_kwargs={"colors:False"}) # doctest: +SKIP + + """ + tests_successful = True + + test_kwargs = test_kwargs or {} + doctest_kwargs = doctest_kwargs or {} + examples_kwargs = examples_kwargs or {'quiet': True} + + try: + # Regular tests + if not test(*test_args, **test_kwargs): + # some regular test fails, so set the tests_successful + # flag to false and continue running the doctests + tests_successful = False + + # Doctests + print() + if not doctest(*doctest_args, **doctest_kwargs): + tests_successful = False + + # Examples + print() + sys.path.append("examples") # examples/all.py + from all import run_examples # type: ignore + if not run_examples(*examples_args, **examples_kwargs): + tests_successful = False + + if tests_successful: + return + else: + # Return nonzero exit code + sys.exit(1) + except KeyboardInterrupt: + print() + print("DO *NOT* COMMIT!") + sys.exit(1) + + +def test(*paths, subprocess=True, rerun=0, **kwargs): + """ + Run tests in the specified test_*.py files. + + Tests in a particular test_*.py file are run if any of the given strings + in ``paths`` matches a part of the test file's path. If ``paths=[]``, + tests in all test_*.py files are run. + + Notes: + + - If sort=False, tests are run in random order (not default). + - Paths can be entered in native system format or in unix, + forward-slash format. + - Files that are on the blacklist can be tested by providing + their path; they are only excluded if no paths are given. + + **Explanation of test results** + + ====== =============================================================== + Output Meaning + ====== =============================================================== + . passed + F failed + X XPassed (expected to fail but passed) + f XFAILed (expected to fail and indeed failed) + s skipped + w slow + T timeout (e.g., when ``--timeout`` is used) + K KeyboardInterrupt (when running the slow tests with ``--slow``, + you can interrupt one of them without killing the test runner) + ====== =============================================================== + + + Colors have no additional meaning and are used just to facilitate + interpreting the output. + + Examples + ======== + + >>> import sympy + + Run all tests: + + >>> sympy.test() # doctest: +SKIP + + Run one file: + + >>> sympy.test("sympy/core/tests/test_basic.py") # doctest: +SKIP + >>> sympy.test("_basic") # doctest: +SKIP + + Run all tests in sympy/functions/ and some particular file: + + >>> sympy.test("sympy/core/tests/test_basic.py", + ... "sympy/functions") # doctest: +SKIP + + Run all tests in sympy/core and sympy/utilities: + + >>> sympy.test("/core", "/util") # doctest: +SKIP + + Run specific test from a file: + + >>> sympy.test("sympy/core/tests/test_basic.py", + ... kw="test_equality") # doctest: +SKIP + + Run specific test from any file: + + >>> sympy.test(kw="subs") # doctest: +SKIP + + Run the tests with verbose mode on: + + >>> sympy.test(verbose=True) # doctest: +SKIP + + Do not sort the test output: + + >>> sympy.test(sort=False) # doctest: +SKIP + + Turn on post-mortem pdb: + + >>> sympy.test(pdb=True) # doctest: +SKIP + + Turn off colors: + + >>> sympy.test(colors=False) # doctest: +SKIP + + Force colors, even when the output is not to a terminal (this is useful, + e.g., if you are piping to ``less -r`` and you still want colors) + + >>> sympy.test(force_colors=False) # doctest: +SKIP + + The traceback verboseness can be set to "short" or "no" (default is + "short") + + >>> sympy.test(tb='no') # doctest: +SKIP + + The ``split`` option can be passed to split the test run into parts. The + split currently only splits the test files, though this may change in the + future. ``split`` should be a string of the form 'a/b', which will run + part ``a`` of ``b``. For instance, to run the first half of the test suite: + + >>> sympy.test(split='1/2') # doctest: +SKIP + + The ``time_balance`` option can be passed in conjunction with ``split``. + If ``time_balance=True`` (the default for ``sympy.test``), SymPy will attempt + to split the tests such that each split takes equal time. This heuristic + for balancing is based on pre-recorded test data. + + >>> sympy.test(split='1/2', time_balance=True) # doctest: +SKIP + + You can disable running the tests in a separate subprocess using + ``subprocess=False``. This is done to support seeding hash randomization, + which is enabled by default in the Python versions where it is supported. + If subprocess=False, hash randomization is enabled/disabled according to + whether it has been enabled or not in the calling Python process. + However, even if it is enabled, the seed cannot be printed unless it is + called from a new Python process. + + Hash randomization was added in the minor Python versions 2.6.8, 2.7.3, + 3.1.5, and 3.2.3, and is enabled by default in all Python versions after + and including 3.3.0. + + If hash randomization is not supported ``subprocess=False`` is used + automatically. + + >>> sympy.test(subprocess=False) # doctest: +SKIP + + To set the hash randomization seed, set the environment variable + ``PYTHONHASHSEED`` before running the tests. This can be done from within + Python using + + >>> import os + >>> os.environ['PYTHONHASHSEED'] = '42' # doctest: +SKIP + + Or from the command line using + + $ PYTHONHASHSEED=42 ./bin/test + + If the seed is not set, a random seed will be chosen. + + Note that to reproduce the same hash values, you must use both the same seed + as well as the same architecture (32-bit vs. 64-bit). + + """ + # count up from 0, do not print 0 + print_counter = lambda i : (print("rerun %d" % (rerun-i)) + if rerun-i else None) + + if subprocess: + # loop backwards so last i is 0 + for i in range(rerun, -1, -1): + print_counter(i) + ret = run_in_subprocess_with_hash_randomization("_test", + function_args=paths, function_kwargs=kwargs) + if ret is False: + break + val = not bool(ret) + # exit on the first failure or if done + if not val or i == 0: + return val + + # rerun even if hash randomization is not supported + for i in range(rerun, -1, -1): + print_counter(i) + val = not bool(_test(*paths, **kwargs)) + if not val or i == 0: + return val + + +def _test(*paths, + verbose=False, tb="short", kw=None, pdb=False, colors=True, + force_colors=False, sort=True, seed=None, timeout=False, + fail_on_timeout=False, slow=False, enhance_asserts=False, split=None, + time_balance=True, blacklist=(), + fast_threshold=None, slow_threshold=None): + """ + Internal function that actually runs the tests. + + All keyword arguments from ``test()`` are passed to this function except for + ``subprocess``. + + Returns 0 if tests passed and 1 if they failed. See the docstring of + ``test()`` for more information. + """ + kw = kw or () + # ensure that kw is a tuple + if isinstance(kw, str): + kw = (kw,) + post_mortem = pdb + if seed is None: + seed = random.randrange(100000000) + if ON_CI and timeout is False: + timeout = 595 + fail_on_timeout = True + if ON_CI: + blacklist = list(blacklist) + ['sympy/plotting/pygletplot/tests'] + blacklist = convert_to_native_paths(blacklist) + r = PyTestReporter(verbose=verbose, tb=tb, colors=colors, + force_colors=force_colors, split=split) + # This won't strictly run the test for the corresponding file, but it is + # good enough for copying and pasting the failing test. + _paths = [] + for path in paths: + if '::' in path: + path, _kw = path.split('::', 1) + kw += (_kw,) + _paths.append(path) + paths = _paths + + t = SymPyTests(r, kw, post_mortem, seed, + fast_threshold=fast_threshold, + slow_threshold=slow_threshold) + + test_files = t.get_test_files('sympy') + + not_blacklisted = [f for f in test_files + if not any(b in f for b in blacklist)] + + if len(paths) == 0: + matched = not_blacklisted + else: + paths = convert_to_native_paths(paths) + matched = [] + for f in not_blacklisted: + basename = os.path.basename(f) + for p in paths: + if p in f or fnmatch(basename, p): + matched.append(f) + break + + density = None + if time_balance: + if slow: + density = SPLIT_DENSITY_SLOW + else: + density = SPLIT_DENSITY + + if split: + matched = split_list(matched, split, density=density) + + t._testfiles.extend(matched) + + return int(not t.test(sort=sort, timeout=timeout, slow=slow, + enhance_asserts=enhance_asserts, fail_on_timeout=fail_on_timeout)) + + +def doctest(*paths, subprocess=True, rerun=0, **kwargs): + r""" + Runs doctests in all \*.py files in the SymPy directory which match + any of the given strings in ``paths`` or all tests if paths=[]. + + Notes: + + - Paths can be entered in native system format or in unix, + forward-slash format. + - Files that are on the blacklist can be tested by providing + their path; they are only excluded if no paths are given. + + Examples + ======== + + >>> import sympy + + Run all tests: + + >>> sympy.doctest() # doctest: +SKIP + + Run one file: + + >>> sympy.doctest("sympy/core/basic.py") # doctest: +SKIP + >>> sympy.doctest("polynomial.rst") # doctest: +SKIP + + Run all tests in sympy/functions/ and some particular file: + + >>> sympy.doctest("/functions", "basic.py") # doctest: +SKIP + + Run any file having polynomial in its name, doc/src/modules/polynomial.rst, + sympy/functions/special/polynomials.py, and sympy/polys/polynomial.py: + + >>> sympy.doctest("polynomial") # doctest: +SKIP + + The ``split`` option can be passed to split the test run into parts. The + split currently only splits the test files, though this may change in the + future. ``split`` should be a string of the form 'a/b', which will run + part ``a`` of ``b``. Note that the regular doctests and the Sphinx + doctests are split independently. For instance, to run the first half of + the test suite: + + >>> sympy.doctest(split='1/2') # doctest: +SKIP + + The ``subprocess`` and ``verbose`` options are the same as with the function + ``test()`` (see the docstring of that function for more information) except + that ``verbose`` may also be set equal to ``2`` in order to print + individual doctest lines, as they are being tested. + """ + # count up from 0, do not print 0 + print_counter = lambda i : (print("rerun %d" % (rerun-i)) + if rerun-i else None) + + if subprocess: + # loop backwards so last i is 0 + for i in range(rerun, -1, -1): + print_counter(i) + ret = run_in_subprocess_with_hash_randomization("_doctest", + function_args=paths, function_kwargs=kwargs) + if ret is False: + break + val = not bool(ret) + # exit on the first failure or if done + if not val or i == 0: + return val + + # rerun even if hash randomization is not supported + for i in range(rerun, -1, -1): + print_counter(i) + val = not bool(_doctest(*paths, **kwargs)) + if not val or i == 0: + return val + + +def _get_doctest_blacklist(): + '''Get the default blacklist for the doctests''' + blacklist = [] + + blacklist.extend([ + "doc/src/modules/plotting.rst", # generates live plots + "doc/src/modules/physics/mechanics/autolev_parser.rst", + "sympy/codegen/array_utils.py", # raises deprecation warning + "sympy/core/compatibility.py", # backwards compatibility shim, importing it triggers a deprecation warning + "sympy/core/trace.py", # backwards compatibility shim, importing it triggers a deprecation warning + "sympy/galgebra.py", # no longer part of SymPy + "sympy/parsing/autolev/_antlr/autolevlexer.py", # generated code + "sympy/parsing/autolev/_antlr/autolevlistener.py", # generated code + "sympy/parsing/autolev/_antlr/autolevparser.py", # generated code + "sympy/parsing/latex/_antlr/latexlexer.py", # generated code + "sympy/parsing/latex/_antlr/latexparser.py", # generated code + "sympy/plotting/pygletplot/__init__.py", # crashes on some systems + "sympy/plotting/pygletplot/plot.py", # crashes on some systems + "sympy/printing/ccode.py", # backwards compatibility shim, importing it breaks the codegen doctests + "sympy/printing/cxxcode.py", # backwards compatibility shim, importing it breaks the codegen doctests + "sympy/printing/fcode.py", # backwards compatibility shim, importing it breaks the codegen doctests + "sympy/testing/randtest.py", # backwards compatibility shim, importing it triggers a deprecation warning + "sympy/this.py", # prints text + ]) + # autolev parser tests + num = 12 + for i in range (1, num+1): + blacklist.append("sympy/parsing/autolev/test-examples/ruletest" + str(i) + ".py") + blacklist.extend(["sympy/parsing/autolev/test-examples/pydy-example-repo/mass_spring_damper.py", + "sympy/parsing/autolev/test-examples/pydy-example-repo/chaos_pendulum.py", + "sympy/parsing/autolev/test-examples/pydy-example-repo/double_pendulum.py", + "sympy/parsing/autolev/test-examples/pydy-example-repo/non_min_pendulum.py"]) + + if import_module('numpy') is None: + blacklist.extend([ + "sympy/plotting/experimental_lambdify.py", + "sympy/plotting/plot_implicit.py", + "examples/advanced/autowrap_integrators.py", + "examples/advanced/autowrap_ufuncify.py", + "examples/intermediate/sample.py", + "examples/intermediate/mplot2d.py", + "examples/intermediate/mplot3d.py", + "doc/src/modules/numeric-computation.rst", + "doc/src/explanation/best-practices.md", + "doc/src/tutorials/physics/biomechanics/biomechanical-model-example.rst", + "doc/src/tutorials/physics/biomechanics/biomechanics.rst", + ]) + else: + if import_module('matplotlib') is None: + blacklist.extend([ + "examples/intermediate/mplot2d.py", + "examples/intermediate/mplot3d.py" + ]) + else: + # Use a non-windowed backend, so that the tests work on CI + import matplotlib + matplotlib.use('Agg') + + if ON_CI or import_module('pyglet') is None: + blacklist.extend(["sympy/plotting/pygletplot"]) + + if import_module('aesara') is None: + blacklist.extend([ + "sympy/printing/aesaracode.py", + "doc/src/modules/numeric-computation.rst", + ]) + + if import_module('cupy') is None: + blacklist.extend([ + "doc/src/modules/numeric-computation.rst", + ]) + + if import_module('jax') is None: + blacklist.extend([ + "doc/src/modules/numeric-computation.rst", + ]) + + if import_module('antlr4') is None: + blacklist.extend([ + "sympy/parsing/autolev/__init__.py", + "sympy/parsing/latex/_parse_latex_antlr.py", + ]) + + if import_module('lfortran') is None: + #throws ImportError when lfortran not installed + blacklist.extend([ + "sympy/parsing/sym_expr.py", + ]) + + if import_module("scipy") is None: + # throws ModuleNotFoundError when scipy not installed + blacklist.extend([ + "doc/src/guides/solving/solve-numerically.md", + "doc/src/guides/solving/solve-ode.md", + ]) + + if import_module("numpy") is None: + # throws ModuleNotFoundError when numpy not installed + blacklist.extend([ + "doc/src/guides/solving/solve-ode.md", + "doc/src/guides/solving/solve-numerically.md", + ]) + + # disabled because of doctest failures in asmeurer's bot + blacklist.extend([ + "sympy/utilities/autowrap.py", + "examples/advanced/autowrap_integrators.py", + "examples/advanced/autowrap_ufuncify.py" + ]) + + blacklist.extend([ + "sympy/conftest.py", # Depends on pytest + ]) + + # These are deprecated stubs to be removed: + blacklist.extend([ + "sympy/utilities/tmpfiles.py", + "sympy/utilities/pytest.py", + "sympy/utilities/runtests.py", + "sympy/utilities/quality_unicode.py", + "sympy/utilities/randtest.py", + ]) + + blacklist = convert_to_native_paths(blacklist) + return blacklist + + +def _doctest(*paths, **kwargs): + """ + Internal function that actually runs the doctests. + + All keyword arguments from ``doctest()`` are passed to this function + except for ``subprocess``. + + Returns 0 if tests passed and 1 if they failed. See the docstrings of + ``doctest()`` and ``test()`` for more information. + """ + from sympy.printing.pretty.pretty import pprint_use_unicode + from sympy.printing.pretty import stringpict + + normal = kwargs.get("normal", False) + verbose = kwargs.get("verbose", False) + colors = kwargs.get("colors", True) + force_colors = kwargs.get("force_colors", False) + blacklist = kwargs.get("blacklist", []) + split = kwargs.get('split', None) + + blacklist.extend(_get_doctest_blacklist()) + + # Use a non-windowed backend, so that the tests work on CI + if import_module('matplotlib') is not None: + import matplotlib + matplotlib.use('Agg') + + # Disable warnings for external modules + import sympy.external + sympy.external.importtools.WARN_OLD_VERSION = False + sympy.external.importtools.WARN_NOT_INSTALLED = False + + # Disable showing up of plots + from sympy.plotting.plot import unset_show + unset_show() + + r = PyTestReporter(verbose, split=split, colors=colors,\ + force_colors=force_colors) + t = SymPyDocTests(r, normal) + + test_files = t.get_test_files('sympy') + test_files.extend(t.get_test_files('examples', init_only=False)) + + not_blacklisted = [f for f in test_files + if not any(b in f for b in blacklist)] + if len(paths) == 0: + matched = not_blacklisted + else: + # take only what was requested...but not blacklisted items + # and allow for partial match anywhere or fnmatch of name + paths = convert_to_native_paths(paths) + matched = [] + for f in not_blacklisted: + basename = os.path.basename(f) + for p in paths: + if p in f or fnmatch(basename, p): + matched.append(f) + break + + matched.sort() + + if split: + matched = split_list(matched, split) + + t._testfiles.extend(matched) + + # run the tests and record the result for this *py portion of the tests + if t._testfiles: + failed = not t.test() + else: + failed = False + + # N.B. + # -------------------------------------------------------------------- + # Here we test *.rst and *.md files at or below doc/src. Code from these + # must be self supporting in terms of imports since there is no importing + # of necessary modules by doctest.testfile. If you try to pass *.py files + # through this they might fail because they will lack the needed imports + # and smarter parsing that can be done with source code. + # + test_files_rst = t.get_test_files('doc/src', '*.rst', init_only=False) + test_files_md = t.get_test_files('doc/src', '*.md', init_only=False) + test_files = test_files_rst + test_files_md + test_files.sort() + + not_blacklisted = [f for f in test_files + if not any(b in f for b in blacklist)] + + if len(paths) == 0: + matched = not_blacklisted + else: + # Take only what was requested as long as it's not on the blacklist. + # Paths were already made native in *py tests so don't repeat here. + # There's no chance of having a *py file slip through since we + # only have *rst files in test_files. + matched = [] + for f in not_blacklisted: + basename = os.path.basename(f) + for p in paths: + if p in f or fnmatch(basename, p): + matched.append(f) + break + + if split: + matched = split_list(matched, split) + + first_report = True + for rst_file in matched: + if not os.path.isfile(rst_file): + continue + old_displayhook = sys.displayhook + try: + use_unicode_prev, wrap_line_prev = setup_pprint() + out = sympytestfile( + rst_file, module_relative=False, encoding='utf-8', + optionflags=pdoctest.ELLIPSIS | pdoctest.NORMALIZE_WHITESPACE | + pdoctest.IGNORE_EXCEPTION_DETAIL) + finally: + # make sure we return to the original displayhook in case some + # doctest has changed that + sys.displayhook = old_displayhook + # The NO_GLOBAL flag overrides the no_global flag to init_printing + # if True + import sympy.interactive.printing as interactive_printing + interactive_printing.NO_GLOBAL = False + pprint_use_unicode(use_unicode_prev) + stringpict._GLOBAL_WRAP_LINE = wrap_line_prev + + rstfailed, tested = out + if tested: + failed = rstfailed or failed + if first_report: + first_report = False + msg = 'rst/md doctests start' + if not t._testfiles: + r.start(msg=msg) + else: + r.write_center(msg) + print() + # use as the id, everything past the first 'sympy' + file_id = rst_file[rst_file.find('sympy') + len('sympy') + 1:] + print(file_id, end=" ") + # get at least the name out so it is know who is being tested + wid = r.terminal_width - len(file_id) - 1 # update width + test_file = '[%s]' % (tested) + report = '[%s]' % (rstfailed or 'OK') + print(''.join( + [test_file, ' '*(wid - len(test_file) - len(report)), report]) + ) + + # the doctests for *py will have printed this message already if there was + # a failure, so now only print it if there was intervening reporting by + # testing the *rst as evidenced by first_report no longer being True. + if not first_report and failed: + print() + print("DO *NOT* COMMIT!") + + return int(failed) + +sp = re.compile(r'([0-9]+)/([1-9][0-9]*)') + +def split_list(l, split, density=None): + """ + Splits a list into part a of b + + split should be a string of the form 'a/b'. For instance, '1/3' would give + the split one of three. + + If the length of the list is not divisible by the number of splits, the + last split will have more items. + + `density` may be specified as a list. If specified, + tests will be balanced so that each split has as equal-as-possible + amount of mass according to `density`. + + >>> from sympy.testing.runtests import split_list + >>> a = list(range(10)) + >>> split_list(a, '1/3') + [0, 1, 2] + >>> split_list(a, '2/3') + [3, 4, 5] + >>> split_list(a, '3/3') + [6, 7, 8, 9] + """ + m = sp.match(split) + if not m: + raise ValueError("split must be a string of the form a/b where a and b are ints") + i, t = map(int, m.groups()) + + if not density: + return l[(i - 1)*len(l)//t : i*len(l)//t] + + # normalize density + tot = sum(density) + density = [x / tot for x in density] + + def density_inv(x): + """Interpolate the inverse to the cumulative + distribution function given by density""" + if x <= 0: + return 0 + if x >= sum(density): + return 1 + + # find the first time the cumulative sum surpasses x + # and linearly interpolate + cumm = 0 + for i, d in enumerate(density): + cumm += d + if cumm >= x: + break + frac = (d - (cumm - x)) / d + return (i + frac) / len(density) + + lower_frac = density_inv((i - 1) / t) + higher_frac = density_inv(i / t) + return l[int(lower_frac*len(l)) : int(higher_frac*len(l))] + +from collections import namedtuple +SymPyTestResults = namedtuple('SymPyTestResults', 'failed attempted') + +def sympytestfile(filename, module_relative=True, name=None, package=None, + globs=None, verbose=None, report=True, optionflags=0, + extraglobs=None, raise_on_error=False, + parser=pdoctest.DocTestParser(), encoding=None): + + """ + Test examples in the given file. Return (#failures, #tests). + + Optional keyword arg ``module_relative`` specifies how filenames + should be interpreted: + + - If ``module_relative`` is True (the default), then ``filename`` + specifies a module-relative path. By default, this path is + relative to the calling module's directory; but if the + ``package`` argument is specified, then it is relative to that + package. To ensure os-independence, ``filename`` should use + "/" characters to separate path segments, and should not + be an absolute path (i.e., it may not begin with "/"). + + - If ``module_relative`` is False, then ``filename`` specifies an + os-specific path. The path may be absolute or relative (to + the current working directory). + + Optional keyword arg ``name`` gives the name of the test; by default + use the file's basename. + + Optional keyword argument ``package`` is a Python package or the + name of a Python package whose directory should be used as the + base directory for a module relative filename. If no package is + specified, then the calling module's directory is used as the base + directory for module relative filenames. It is an error to + specify ``package`` if ``module_relative`` is False. + + Optional keyword arg ``globs`` gives a dict to be used as the globals + when executing examples; by default, use {}. A copy of this dict + is actually used for each docstring, so that each docstring's + examples start with a clean slate. + + Optional keyword arg ``extraglobs`` gives a dictionary that should be + merged into the globals that are used to execute examples. By + default, no extra globals are used. + + Optional keyword arg ``verbose`` prints lots of stuff if true, prints + only failures if false; by default, it's true iff "-v" is in sys.argv. + + Optional keyword arg ``report`` prints a summary at the end when true, + else prints nothing at the end. In verbose mode, the summary is + detailed, else very brief (in fact, empty if all tests passed). + + Optional keyword arg ``optionflags`` or's together module constants, + and defaults to 0. Possible values (see the docs for details): + + - DONT_ACCEPT_TRUE_FOR_1 + - DONT_ACCEPT_BLANKLINE + - NORMALIZE_WHITESPACE + - ELLIPSIS + - SKIP + - IGNORE_EXCEPTION_DETAIL + - REPORT_UDIFF + - REPORT_CDIFF + - REPORT_NDIFF + - REPORT_ONLY_FIRST_FAILURE + + Optional keyword arg ``raise_on_error`` raises an exception on the + first unexpected exception or failure. This allows failures to be + post-mortem debugged. + + Optional keyword arg ``parser`` specifies a DocTestParser (or + subclass) that should be used to extract tests from the files. + + Optional keyword arg ``encoding`` specifies an encoding that should + be used to convert the file to unicode. + + Advanced tomfoolery: testmod runs methods of a local instance of + class doctest.Tester, then merges the results into (or creates) + global Tester instance doctest.master. Methods of doctest.master + can be called directly too, if you want to do something unusual. + Passing report=0 to testmod is especially useful then, to delay + displaying a summary. Invoke doctest.master.summarize(verbose) + when you're done fiddling. + """ + if package and not module_relative: + raise ValueError("Package may only be specified for module-" + "relative paths.") + + # Relativize the path + text, filename = pdoctest._load_testfile( + filename, package, module_relative, encoding) + + # If no name was given, then use the file's name. + if name is None: + name = os.path.basename(filename) + + # Assemble the globals. + if globs is None: + globs = {} + else: + globs = globs.copy() + if extraglobs is not None: + globs.update(extraglobs) + if '__name__' not in globs: + globs['__name__'] = '__main__' + + if raise_on_error: + runner = pdoctest.DebugRunner(verbose=verbose, optionflags=optionflags) + else: + runner = SymPyDocTestRunner(verbose=verbose, optionflags=optionflags) + runner._checker = SymPyOutputChecker() + + # Read the file, convert it to a test, and run it. + test = parser.get_doctest(text, globs, name, filename, 0) + runner.run(test) + + if report: + runner.summarize() + + if pdoctest.master is None: + pdoctest.master = runner + else: + pdoctest.master.merge(runner) + + return SymPyTestResults(runner.failures, runner.tries) + + +class SymPyTests: + + def __init__(self, reporter, kw="", post_mortem=False, + seed=None, fast_threshold=None, slow_threshold=None): + self._post_mortem = post_mortem + self._kw = kw + self._count = 0 + self._root_dir = get_sympy_dir() + self._reporter = reporter + self._reporter.root_dir(self._root_dir) + self._testfiles = [] + self._seed = seed if seed is not None else random.random() + + # Defaults in seconds, from human / UX design limits + # http://www.nngroup.com/articles/response-times-3-important-limits/ + # + # These defaults are *NOT* set in stone as we are measuring different + # things, so others feel free to come up with a better yardstick :) + if fast_threshold: + self._fast_threshold = float(fast_threshold) + else: + self._fast_threshold = 8 + if slow_threshold: + self._slow_threshold = float(slow_threshold) + else: + self._slow_threshold = 10 + + def test(self, sort=False, timeout=False, slow=False, + enhance_asserts=False, fail_on_timeout=False): + """ + Runs the tests returning True if all tests pass, otherwise False. + + If sort=False run tests in random order. + """ + if sort: + self._testfiles.sort() + elif slow: + pass + else: + random.seed(self._seed) + random.shuffle(self._testfiles) + self._reporter.start(self._seed) + for f in self._testfiles: + try: + self.test_file(f, sort, timeout, slow, + enhance_asserts, fail_on_timeout) + except KeyboardInterrupt: + print(" interrupted by user") + self._reporter.finish() + raise + return self._reporter.finish() + + def _enhance_asserts(self, source): + from ast import (NodeTransformer, Compare, Name, Store, Load, Tuple, + Assign, BinOp, Str, Mod, Assert, parse, fix_missing_locations) + + ops = {"Eq": '==', "NotEq": '!=', "Lt": '<', "LtE": '<=', + "Gt": '>', "GtE": '>=', "Is": 'is', "IsNot": 'is not', + "In": 'in', "NotIn": 'not in'} + + class Transform(NodeTransformer): + def visit_Assert(self, stmt): + if isinstance(stmt.test, Compare): + compare = stmt.test + values = [compare.left] + compare.comparators + names = [ "_%s" % i for i, _ in enumerate(values) ] + names_store = [ Name(n, Store()) for n in names ] + names_load = [ Name(n, Load()) for n in names ] + target = Tuple(names_store, Store()) + value = Tuple(values, Load()) + assign = Assign([target], value) + new_compare = Compare(names_load[0], compare.ops, names_load[1:]) + msg_format = "\n%s " + "\n%s ".join([ ops[op.__class__.__name__] for op in compare.ops ]) + "\n%s" + msg = BinOp(Str(msg_format), Mod(), Tuple(names_load, Load())) + test = Assert(new_compare, msg, lineno=stmt.lineno, col_offset=stmt.col_offset) + return [assign, test] + else: + return stmt + + tree = parse(source) + new_tree = Transform().visit(tree) + return fix_missing_locations(new_tree) + + def test_file(self, filename, sort=True, timeout=False, slow=False, + enhance_asserts=False, fail_on_timeout=False): + reporter = self._reporter + funcs = [] + try: + gl = {'__file__': filename} + try: + open_file = lambda: open(filename, encoding="utf8") + + with open_file() as f: + source = f.read() + if self._kw: + for l in source.splitlines(): + if l.lstrip().startswith('def '): + if any(l.lower().find(k.lower()) != -1 for k in self._kw): + break + else: + return + + if enhance_asserts: + try: + source = self._enhance_asserts(source) + except ImportError: + pass + + code = compile(source, filename, "exec", flags=0, dont_inherit=True) + exec(code, gl) + except (SystemExit, KeyboardInterrupt): + raise + except ImportError: + reporter.import_error(filename, sys.exc_info()) + return + except Exception: + reporter.test_exception(sys.exc_info()) + + clear_cache() + self._count += 1 + random.seed(self._seed) + disabled = gl.get("disabled", False) + if not disabled: + # we need to filter only those functions that begin with 'test_' + # We have to be careful about decorated functions. As long as + # the decorator uses functools.wraps, we can detect it. + funcs = [] + for f in gl: + if (f.startswith("test_") and (inspect.isfunction(gl[f]) + or inspect.ismethod(gl[f]))): + func = gl[f] + # Handle multiple decorators + while hasattr(func, '__wrapped__'): + func = func.__wrapped__ + + if inspect.getsourcefile(func) == filename: + funcs.append(gl[f]) + if slow: + funcs = [f for f in funcs if getattr(f, '_slow', False)] + # Sorting of XFAILed functions isn't fixed yet :-( + funcs.sort(key=lambda x: inspect.getsourcelines(x)[1]) + i = 0 + while i < len(funcs): + if inspect.isgeneratorfunction(funcs[i]): + # some tests can be generators, that return the actual + # test functions. We unpack it below: + f = funcs.pop(i) + for fg in f(): + func = fg[0] + args = fg[1:] + fgw = lambda: func(*args) + funcs.insert(i, fgw) + i += 1 + else: + i += 1 + # drop functions that are not selected with the keyword expression: + funcs = [x for x in funcs if self.matches(x)] + + if not funcs: + return + except Exception: + reporter.entering_filename(filename, len(funcs)) + raise + + reporter.entering_filename(filename, len(funcs)) + if not sort: + random.shuffle(funcs) + + for f in funcs: + start = time.time() + reporter.entering_test(f) + try: + if getattr(f, '_slow', False) and not slow: + raise Skipped("Slow") + with raise_on_deprecated(): + if timeout: + self._timeout(f, timeout, fail_on_timeout) + else: + random.seed(self._seed) + f() + except KeyboardInterrupt: + if getattr(f, '_slow', False): + reporter.test_skip("KeyboardInterrupt") + else: + raise + except Exception: + if timeout: + signal.alarm(0) # Disable the alarm. It could not be handled before. + t, v, tr = sys.exc_info() + if t is AssertionError: + reporter.test_fail((t, v, tr)) + if self._post_mortem: + pdb.post_mortem(tr) + elif t.__name__ == "Skipped": + reporter.test_skip(v) + elif t.__name__ == "XFail": + reporter.test_xfail() + elif t.__name__ == "XPass": + reporter.test_xpass(v) + else: + reporter.test_exception((t, v, tr)) + if self._post_mortem: + pdb.post_mortem(tr) + else: + reporter.test_pass() + taken = time.time() - start + if taken > self._slow_threshold: + filename = os.path.relpath(filename, reporter._root_dir) + reporter.slow_test_functions.append( + (filename + "::" + f.__name__, taken)) + if getattr(f, '_slow', False) and slow: + if taken < self._fast_threshold: + filename = os.path.relpath(filename, reporter._root_dir) + reporter.fast_test_functions.append( + (filename + "::" + f.__name__, taken)) + reporter.leaving_filename() + + def _timeout(self, function, timeout, fail_on_timeout): + def callback(x, y): + signal.alarm(0) + if fail_on_timeout: + raise TimeOutError("Timed out after %d seconds" % timeout) + else: + raise Skipped("Timeout") + signal.signal(signal.SIGALRM, callback) + signal.alarm(timeout) # Set an alarm with a given timeout + function() + signal.alarm(0) # Disable the alarm + + def matches(self, x): + """ + Does the keyword expression self._kw match "x"? Returns True/False. + + Always returns True if self._kw is "". + """ + if not self._kw: + return True + for kw in self._kw: + if x.__name__.lower().find(kw.lower()) != -1: + return True + return False + + def get_test_files(self, dir, pat='test_*.py'): + """ + Returns the list of test_*.py (default) files at or below directory + ``dir`` relative to the SymPy home directory. + """ + dir = os.path.join(self._root_dir, convert_to_native_paths([dir])[0]) + + g = [] + for path, folders, files in os.walk(dir): + g.extend([os.path.join(path, f) for f in files if fnmatch(f, pat)]) + + return sorted([os.path.normcase(gi) for gi in g]) + + +class SymPyDocTests: + + def __init__(self, reporter, normal): + self._count = 0 + self._root_dir = get_sympy_dir() + self._reporter = reporter + self._reporter.root_dir(self._root_dir) + self._normal = normal + + self._testfiles = [] + + def test(self): + """ + Runs the tests and returns True if all tests pass, otherwise False. + """ + self._reporter.start() + for f in self._testfiles: + try: + self.test_file(f) + except KeyboardInterrupt: + print(" interrupted by user") + self._reporter.finish() + raise + return self._reporter.finish() + + def test_file(self, filename): + clear_cache() + + from io import StringIO + import sympy.interactive.printing as interactive_printing + from sympy.printing.pretty.pretty import pprint_use_unicode + from sympy.printing.pretty import stringpict + + rel_name = filename[len(self._root_dir) + 1:] + dirname, file = os.path.split(filename) + module = rel_name.replace(os.sep, '.')[:-3] + + if rel_name.startswith("examples"): + # Examples files do not have __init__.py files, + # So we have to temporarily extend sys.path to import them + sys.path.insert(0, dirname) + module = file[:-3] # remove ".py" + try: + module = pdoctest._normalize_module(module) + tests = SymPyDocTestFinder().find(module) + except (SystemExit, KeyboardInterrupt): + raise + except ImportError: + self._reporter.import_error(filename, sys.exc_info()) + return + finally: + if rel_name.startswith("examples"): + del sys.path[0] + + tests = [test for test in tests if len(test.examples) > 0] + # By default tests are sorted by alphabetical order by function name. + # We sort by line number so one can edit the file sequentially from + # bottom to top. However, if there are decorated functions, their line + # numbers will be too large and for now one must just search for these + # by text and function name. + tests.sort(key=lambda x: -x.lineno) + + if not tests: + return + self._reporter.entering_filename(filename, len(tests)) + for test in tests: + assert len(test.examples) != 0 + + if self._reporter._verbose: + self._reporter.write("\n{} ".format(test.name)) + + # check if there are external dependencies which need to be met + if '_doctest_depends_on' in test.globs: + try: + self._check_dependencies(**test.globs['_doctest_depends_on']) + except DependencyError as e: + self._reporter.test_skip(v=str(e)) + continue + + runner = SymPyDocTestRunner(verbose=self._reporter._verbose==2, + optionflags=pdoctest.ELLIPSIS | + pdoctest.NORMALIZE_WHITESPACE | + pdoctest.IGNORE_EXCEPTION_DETAIL) + runner._checker = SymPyOutputChecker() + old = sys.stdout + new = old if self._reporter._verbose==2 else StringIO() + sys.stdout = new + # If the testing is normal, the doctests get importing magic to + # provide the global namespace. If not normal (the default) then + # then must run on their own; all imports must be explicit within + # a function's docstring. Once imported that import will be + # available to the rest of the tests in a given function's + # docstring (unless clear_globs=True below). + if not self._normal: + test.globs = {} + # if this is uncommented then all the test would get is what + # comes by default with a "from sympy import *" + #exec('from sympy import *') in test.globs + old_displayhook = sys.displayhook + use_unicode_prev, wrap_line_prev = setup_pprint() + + try: + f, t = runner.run(test, + out=new.write, clear_globs=False) + except KeyboardInterrupt: + raise + finally: + sys.stdout = old + if f > 0: + self._reporter.doctest_fail(test.name, new.getvalue()) + else: + self._reporter.test_pass() + sys.displayhook = old_displayhook + interactive_printing.NO_GLOBAL = False + pprint_use_unicode(use_unicode_prev) + stringpict._GLOBAL_WRAP_LINE = wrap_line_prev + + self._reporter.leaving_filename() + + def get_test_files(self, dir, pat='*.py', init_only=True): + r""" + Returns the list of \*.py files (default) from which docstrings + will be tested which are at or below directory ``dir``. By default, + only those that have an __init__.py in their parent directory + and do not start with ``test_`` will be included. + """ + def importable(x): + """ + Checks if given pathname x is an importable module by checking for + __init__.py file. + + Returns True/False. + + Currently we only test if the __init__.py file exists in the + directory with the file "x" (in theory we should also test all the + parent dirs). + """ + init_py = os.path.join(os.path.dirname(x), "__init__.py") + return os.path.exists(init_py) + + dir = os.path.join(self._root_dir, convert_to_native_paths([dir])[0]) + + g = [] + for path, folders, files in os.walk(dir): + g.extend([os.path.join(path, f) for f in files + if not f.startswith('test_') and fnmatch(f, pat)]) + if init_only: + # skip files that are not importable (i.e. missing __init__.py) + g = [x for x in g if importable(x)] + + return [os.path.normcase(gi) for gi in g] + + def _check_dependencies(self, + executables=(), + modules=(), + disable_viewers=(), + python_version=(3, 5), + ground_types=None): + """ + Checks if the dependencies for the test are installed. + + Raises ``DependencyError`` it at least one dependency is not installed. + """ + + for executable in executables: + if not shutil.which(executable): + raise DependencyError("Could not find %s" % executable) + + for module in modules: + if module == 'matplotlib': + matplotlib = import_module( + 'matplotlib', + import_kwargs={'fromlist': + ['pyplot', 'cm', 'collections']}, + min_module_version='1.0.0', catch=(RuntimeError,)) + if matplotlib is None: + raise DependencyError("Could not import matplotlib") + else: + if not import_module(module): + raise DependencyError("Could not import %s" % module) + + if disable_viewers: + tempdir = tempfile.mkdtemp() + os.environ['PATH'] = '%s:%s' % (tempdir, os.environ['PATH']) + + vw = ('#!/usr/bin/env python3\n' + 'import sys\n' + 'if len(sys.argv) <= 1:\n' + ' exit("wrong number of args")\n') + + for viewer in disable_viewers: + Path(os.path.join(tempdir, viewer)).write_text(vw) + + # make the file executable + os.chmod(os.path.join(tempdir, viewer), + stat.S_IREAD | stat.S_IWRITE | stat.S_IXUSR) + + if python_version: + if sys.version_info < python_version: + raise DependencyError("Requires Python >= " + '.'.join(map(str, python_version))) + + if ground_types is not None: + if GROUND_TYPES not in ground_types: + raise DependencyError("Requires ground_types in " + str(ground_types)) + + if 'pyglet' in modules: + # monkey-patch pyglet s.t. it does not open a window during + # doctesting + import pyglet + class DummyWindow: + def __init__(self, *args, **kwargs): + self.has_exit = True + self.width = 600 + self.height = 400 + + def set_vsync(self, x): + pass + + def switch_to(self): + pass + + def push_handlers(self, x): + pass + + def close(self): + pass + + pyglet.window.Window = DummyWindow + + +class SymPyDocTestFinder(DocTestFinder): + """ + A class used to extract the DocTests that are relevant to a given + object, from its docstring and the docstrings of its contained + objects. Doctests can currently be extracted from the following + object types: modules, functions, classes, methods, staticmethods, + classmethods, and properties. + + Modified from doctest's version to look harder for code that + appears comes from a different module. For example, the @vectorize + decorator makes it look like functions come from multidimensional.py + even though their code exists elsewhere. + """ + + def _find(self, tests, obj, name, module, source_lines, globs, seen): + """ + Find tests for the given object and any contained objects, and + add them to ``tests``. + """ + if self._verbose: + print('Finding tests in %s' % name) + + # If we've already processed this object, then ignore it. + if id(obj) in seen: + return + seen[id(obj)] = 1 + + # Make sure we don't run doctests for classes outside of sympy, such + # as in numpy or scipy. + if inspect.isclass(obj): + if obj.__module__.split('.')[0] != 'sympy': + return + + # Find a test for this object, and add it to the list of tests. + test = self._get_test(obj, name, module, globs, source_lines) + if test is not None: + tests.append(test) + + if not self._recurse: + return + + # Look for tests in a module's contained objects. + if inspect.ismodule(obj): + for rawname, val in obj.__dict__.items(): + # Recurse to functions & classes. + if inspect.isfunction(val) or inspect.isclass(val): + # Make sure we don't run doctests functions or classes + # from different modules + if val.__module__ != module.__name__: + continue + + assert self._from_module(module, val), \ + "%s is not in module %s (rawname %s)" % (val, module, rawname) + + try: + valname = '%s.%s' % (name, rawname) + self._find(tests, val, valname, module, + source_lines, globs, seen) + except KeyboardInterrupt: + raise + + # Look for tests in a module's __test__ dictionary. + for valname, val in getattr(obj, '__test__', {}).items(): + if not isinstance(valname, str): + raise ValueError("SymPyDocTestFinder.find: __test__ keys " + "must be strings: %r" % + (type(valname),)) + if not (inspect.isfunction(val) or inspect.isclass(val) or + inspect.ismethod(val) or inspect.ismodule(val) or + isinstance(val, str)): + raise ValueError("SymPyDocTestFinder.find: __test__ values " + "must be strings, functions, methods, " + "classes, or modules: %r" % + (type(val),)) + valname = '%s.__test__.%s' % (name, valname) + self._find(tests, val, valname, module, source_lines, + globs, seen) + + + # Look for tests in a class's contained objects. + if inspect.isclass(obj): + for valname, val in obj.__dict__.items(): + # Special handling for staticmethod/classmethod. + if isinstance(val, staticmethod): + val = getattr(obj, valname) + if isinstance(val, classmethod): + val = getattr(obj, valname).__func__ + + + # Recurse to methods, properties, and nested classes. + if ((inspect.isfunction(unwrap(val)) or + inspect.isclass(val) or + isinstance(val, property)) and + self._from_module(module, val)): + # Make sure we don't run doctests functions or classes + # from different modules + if isinstance(val, property): + if hasattr(val.fget, '__module__'): + if val.fget.__module__ != module.__name__: + continue + else: + if val.__module__ != module.__name__: + continue + + assert self._from_module(module, val), \ + "%s is not in module %s (valname %s)" % ( + val, module, valname) + + valname = '%s.%s' % (name, valname) + self._find(tests, val, valname, module, source_lines, + globs, seen) + + def _get_test(self, obj, name, module, globs, source_lines): + """ + Return a DocTest for the given object, if it defines a docstring; + otherwise, return None. + """ + + lineno = None + + # Extract the object's docstring. If it does not have one, + # then return None (no test for this object). + if isinstance(obj, str): + # obj is a string in the case for objects in the polys package. + # Note that source_lines is a binary string (compiled polys + # modules), which can't be handled by _find_lineno so determine + # the line number here. + + docstring = obj + + matches = re.findall(r"line \d+", name) + assert len(matches) == 1, \ + "string '%s' does not contain lineno " % name + + # NOTE: this is not the exact linenumber but its better than no + # lineno ;) + lineno = int(matches[0][5:]) + + else: + docstring = getattr(obj, '__doc__', '') + if docstring is None: + docstring = '' + if not isinstance(docstring, str): + docstring = str(docstring) + + # Don't bother if the docstring is empty. + if self._exclude_empty and not docstring: + return None + + # check that properties have a docstring because _find_lineno + # assumes it + if isinstance(obj, property): + if obj.fget.__doc__ is None: + return None + + # Find the docstring's location in the file. + if lineno is None: + obj = unwrap(obj) + # handling of properties is not implemented in _find_lineno so do + # it here + if hasattr(obj, 'func_closure') and obj.func_closure is not None: + tobj = obj.func_closure[0].cell_contents + elif isinstance(obj, property): + tobj = obj.fget + else: + tobj = obj + lineno = self._find_lineno(tobj, source_lines) + + if lineno is None: + return None + + # Return a DocTest for this object. + if module is None: + filename = None + else: + filename = getattr(module, '__file__', module.__name__) + if filename[-4:] in (".pyc", ".pyo"): + filename = filename[:-1] + + globs['_doctest_depends_on'] = getattr(obj, '_doctest_depends_on', {}) + + return self._parser.get_doctest(docstring, globs, name, + filename, lineno) + + +class SymPyDocTestRunner(DocTestRunner): + """ + A class used to run DocTest test cases, and accumulate statistics. + The ``run`` method is used to process a single DocTest case. It + returns a tuple ``(f, t)``, where ``t`` is the number of test cases + tried, and ``f`` is the number of test cases that failed. + + Modified from the doctest version to not reset the sys.displayhook (see + issue 5140). + + See the docstring of the original DocTestRunner for more information. + """ + + def run(self, test, compileflags=None, out=None, clear_globs=True): + """ + Run the examples in ``test``, and display the results using the + writer function ``out``. + + The examples are run in the namespace ``test.globs``. If + ``clear_globs`` is true (the default), then this namespace will + be cleared after the test runs, to help with garbage + collection. If you would like to examine the namespace after + the test completes, then use ``clear_globs=False``. + + ``compileflags`` gives the set of flags that should be used by + the Python compiler when running the examples. If not + specified, then it will default to the set of future-import + flags that apply to ``globs``. + + The output of each example is checked using + ``SymPyDocTestRunner.check_output``, and the results are + formatted by the ``SymPyDocTestRunner.report_*`` methods. + """ + self.test = test + + # Remove ``` from the end of example, which may appear in Markdown + # files + for example in test.examples: + example.want = example.want.replace('```\n', '') + example.exc_msg = example.exc_msg and example.exc_msg.replace('```\n', '') + + + if compileflags is None: + compileflags = pdoctest._extract_future_flags(test.globs) + + save_stdout = sys.stdout + if out is None: + out = save_stdout.write + sys.stdout = self._fakeout + + # Patch pdb.set_trace to restore sys.stdout during interactive + # debugging (so it's not still redirected to self._fakeout). + # Note that the interactive output will go to *our* + # save_stdout, even if that's not the real sys.stdout; this + # allows us to write test cases for the set_trace behavior. + save_set_trace = pdb.set_trace + self.debugger = pdoctest._OutputRedirectingPdb(save_stdout) + self.debugger.reset() + pdb.set_trace = self.debugger.set_trace + + # Patch linecache.getlines, so we can see the example's source + # when we're inside the debugger. + self.save_linecache_getlines = pdoctest.linecache.getlines + linecache.getlines = self.__patched_linecache_getlines + + # Fail for deprecation warnings + with raise_on_deprecated(): + try: + return self.__run(test, compileflags, out) + finally: + sys.stdout = save_stdout + pdb.set_trace = save_set_trace + linecache.getlines = self.save_linecache_getlines + if clear_globs: + test.globs.clear() + + +# We have to override the name mangled methods. +monkeypatched_methods = [ + 'patched_linecache_getlines', + 'run', + 'record_outcome' +] +for method in monkeypatched_methods: + oldname = '_DocTestRunner__' + method + newname = '_SymPyDocTestRunner__' + method + setattr(SymPyDocTestRunner, newname, getattr(DocTestRunner, oldname)) + + +class SymPyOutputChecker(pdoctest.OutputChecker): + """ + Compared to the OutputChecker from the stdlib our OutputChecker class + supports numerical comparison of floats occurring in the output of the + doctest examples + """ + + def __init__(self): + # NOTE OutputChecker is an old-style class with no __init__ method, + # so we can't call the base class version of __init__ here + + got_floats = r'(\d+\.\d*|\.\d+)' + + # floats in the 'want' string may contain ellipses + want_floats = got_floats + r'(\.{3})?' + + front_sep = r'\s|\+|\-|\*|,' + back_sep = front_sep + r'|j|e' + + fbeg = r'^%s(?=%s|$)' % (got_floats, back_sep) + fmidend = r'(?<=%s)%s(?=%s|$)' % (front_sep, got_floats, back_sep) + self.num_got_rgx = re.compile(r'(%s|%s)' %(fbeg, fmidend)) + + fbeg = r'^%s(?=%s|$)' % (want_floats, back_sep) + fmidend = r'(?<=%s)%s(?=%s|$)' % (front_sep, want_floats, back_sep) + self.num_want_rgx = re.compile(r'(%s|%s)' %(fbeg, fmidend)) + + def check_output(self, want, got, optionflags): + """ + Return True iff the actual output from an example (`got`) + matches the expected output (`want`). These strings are + always considered to match if they are identical; but + depending on what option flags the test runner is using, + several non-exact match types are also possible. See the + documentation for `TestRunner` for more information about + option flags. + """ + # Handle the common case first, for efficiency: + # if they're string-identical, always return true. + if got == want: + return True + + # TODO parse integers as well ? + # Parse floats and compare them. If some of the parsed floats contain + # ellipses, skip the comparison. + matches = self.num_got_rgx.finditer(got) + numbers_got = [match.group(1) for match in matches] # list of strs + matches = self.num_want_rgx.finditer(want) + numbers_want = [match.group(1) for match in matches] # list of strs + if len(numbers_got) != len(numbers_want): + return False + + if len(numbers_got) > 0: + nw_ = [] + for ng, nw in zip(numbers_got, numbers_want): + if '...' in nw: + nw_.append(ng) + continue + else: + nw_.append(nw) + + if abs(float(ng)-float(nw)) > 1e-5: + return False + + got = self.num_got_rgx.sub(r'%s', got) + got = got % tuple(nw_) + + # can be used as a special sequence to signify a + # blank line, unless the DONT_ACCEPT_BLANKLINE flag is used. + if not (optionflags & pdoctest.DONT_ACCEPT_BLANKLINE): + # Replace in want with a blank line. + want = re.sub(r'(?m)^%s\s*?$' % re.escape(pdoctest.BLANKLINE_MARKER), + '', want) + # If a line in got contains only spaces, then remove the + # spaces. + got = re.sub(r'(?m)^\s*?$', '', got) + if got == want: + return True + + # This flag causes doctest to ignore any differences in the + # contents of whitespace strings. Note that this can be used + # in conjunction with the ELLIPSIS flag. + if optionflags & pdoctest.NORMALIZE_WHITESPACE: + got = ' '.join(got.split()) + want = ' '.join(want.split()) + if got == want: + return True + + # The ELLIPSIS flag says to let the sequence "..." in `want` + # match any substring in `got`. + if optionflags & pdoctest.ELLIPSIS: + if pdoctest._ellipsis_match(want, got): + return True + + # We didn't find any match; return false. + return False + + +class Reporter: + """ + Parent class for all reporters. + """ + pass + + +class PyTestReporter(Reporter): + """ + Py.test like reporter. Should produce output identical to py.test. + """ + + def __init__(self, verbose=False, tb="short", colors=True, + force_colors=False, split=None): + self._verbose = verbose + self._tb_style = tb + self._colors = colors + self._force_colors = force_colors + self._xfailed = 0 + self._xpassed = [] + self._failed = [] + self._failed_doctest = [] + self._passed = 0 + self._skipped = 0 + self._exceptions = [] + self._terminal_width = None + self._default_width = 80 + self._split = split + self._active_file = '' + self._active_f = None + + # TODO: Should these be protected? + self.slow_test_functions = [] + self.fast_test_functions = [] + + # this tracks the x-position of the cursor (useful for positioning + # things on the screen), without the need for any readline library: + self._write_pos = 0 + self._line_wrap = False + + def root_dir(self, dir): + self._root_dir = dir + + @property + def terminal_width(self): + if self._terminal_width is not None: + return self._terminal_width + + def findout_terminal_width(): + if sys.platform == "win32": + # Windows support is based on: + # + # http://code.activestate.com/recipes/ + # 440694-determine-size-of-console-window-on-windows/ + + from ctypes import windll, create_string_buffer + + h = windll.kernel32.GetStdHandle(-12) + csbi = create_string_buffer(22) + res = windll.kernel32.GetConsoleScreenBufferInfo(h, csbi) + + if res: + import struct + (_, _, _, _, _, left, _, right, _, _, _) = \ + struct.unpack("hhhhHhhhhhh", csbi.raw) + return right - left + else: + return self._default_width + + if hasattr(sys.stdout, 'isatty') and not sys.stdout.isatty(): + return self._default_width # leave PIPEs alone + + try: + process = subprocess.Popen(['stty', '-a'], + stdout=subprocess.PIPE, + stderr=subprocess.PIPE) + stdout, stderr = process.communicate() + stdout = stdout.decode("utf-8") + except OSError: + pass + else: + # We support the following output formats from stty: + # + # 1) Linux -> columns 80 + # 2) OS X -> 80 columns + # 3) Solaris -> columns = 80 + + re_linux = r"columns\s+(?P\d+);" + re_osx = r"(?P\d+)\s*columns;" + re_solaris = r"columns\s+=\s+(?P\d+);" + + for regex in (re_linux, re_osx, re_solaris): + match = re.search(regex, stdout) + + if match is not None: + columns = match.group('columns') + + try: + width = int(columns) + except ValueError: + pass + if width != 0: + return width + + return self._default_width + + width = findout_terminal_width() + self._terminal_width = width + + return width + + def write(self, text, color="", align="left", width=None, + force_colors=False): + """ + Prints a text on the screen. + + It uses sys.stdout.write(), so no readline library is necessary. + + Parameters + ========== + + color : choose from the colors below, "" means default color + align : "left"/"right", "left" is a normal print, "right" is aligned on + the right-hand side of the screen, filled with spaces if + necessary + width : the screen width + + """ + color_templates = ( + ("Black", "0;30"), + ("Red", "0;31"), + ("Green", "0;32"), + ("Brown", "0;33"), + ("Blue", "0;34"), + ("Purple", "0;35"), + ("Cyan", "0;36"), + ("LightGray", "0;37"), + ("DarkGray", "1;30"), + ("LightRed", "1;31"), + ("LightGreen", "1;32"), + ("Yellow", "1;33"), + ("LightBlue", "1;34"), + ("LightPurple", "1;35"), + ("LightCyan", "1;36"), + ("White", "1;37"), + ) + + colors = {} + + for name, value in color_templates: + colors[name] = value + c_normal = '\033[0m' + c_color = '\033[%sm' + + if width is None: + width = self.terminal_width + + if align == "right": + if self._write_pos + len(text) > width: + # we don't fit on the current line, create a new line + self.write("\n") + self.write(" "*(width - self._write_pos - len(text))) + + if not self._force_colors and hasattr(sys.stdout, 'isatty') and not \ + sys.stdout.isatty(): + # the stdout is not a terminal, this for example happens if the + # output is piped to less, e.g. "bin/test | less". In this case, + # the terminal control sequences would be printed verbatim, so + # don't use any colors. + color = "" + elif sys.platform == "win32": + # Windows consoles don't support ANSI escape sequences + color = "" + elif not self._colors: + color = "" + + if self._line_wrap: + if text[0] != "\n": + sys.stdout.write("\n") + + # Avoid UnicodeEncodeError when printing out test failures + if IS_WINDOWS: + text = text.encode('raw_unicode_escape').decode('utf8', 'ignore') + elif not sys.stdout.encoding.lower().startswith('utf'): + text = text.encode(sys.stdout.encoding, 'backslashreplace' + ).decode(sys.stdout.encoding) + + if color == "": + sys.stdout.write(text) + else: + sys.stdout.write("%s%s%s" % + (c_color % colors[color], text, c_normal)) + sys.stdout.flush() + l = text.rfind("\n") + if l == -1: + self._write_pos += len(text) + else: + self._write_pos = len(text) - l - 1 + self._line_wrap = self._write_pos >= width + self._write_pos %= width + + def write_center(self, text, delim="="): + width = self.terminal_width + if text != "": + text = " %s " % text + idx = (width - len(text)) // 2 + t = delim*idx + text + delim*(width - idx - len(text)) + self.write(t + "\n") + + def write_exception(self, e, val, tb): + # remove the first item, as that is always runtests.py + tb = tb.tb_next + t = traceback.format_exception(e, val, tb) + self.write("".join(t)) + + def start(self, seed=None, msg="test process starts"): + self.write_center(msg) + executable = sys.executable + v = tuple(sys.version_info) + python_version = "%s.%s.%s-%s-%s" % v + implementation = platform.python_implementation() + if implementation == 'PyPy': + implementation += " %s.%s.%s-%s-%s" % sys.pypy_version_info + self.write("executable: %s (%s) [%s]\n" % + (executable, python_version, implementation)) + from sympy.utilities.misc import ARCH + self.write("architecture: %s\n" % ARCH) + from sympy.core.cache import USE_CACHE + self.write("cache: %s\n" % USE_CACHE) + version = '' + if GROUND_TYPES =='gmpy': + import gmpy2 as gmpy + version = gmpy.version() + self.write("ground types: %s %s\n" % (GROUND_TYPES, version)) + numpy = import_module('numpy') + self.write("numpy: %s\n" % (None if not numpy else numpy.__version__)) + if seed is not None: + self.write("random seed: %d\n" % seed) + from sympy.utilities.misc import HASH_RANDOMIZATION + self.write("hash randomization: ") + hash_seed = os.getenv("PYTHONHASHSEED") or '0' + if HASH_RANDOMIZATION and (hash_seed == "random" or int(hash_seed)): + self.write("on (PYTHONHASHSEED=%s)\n" % hash_seed) + else: + self.write("off\n") + if self._split: + self.write("split: %s\n" % self._split) + self.write('\n') + self._t_start = clock() + + def finish(self): + self._t_end = clock() + self.write("\n") + global text, linelen + text = "tests finished: %d passed, " % self._passed + linelen = len(text) + + def add_text(mytext): + global text, linelen + """Break new text if too long.""" + if linelen + len(mytext) > self.terminal_width: + text += '\n' + linelen = 0 + text += mytext + linelen += len(mytext) + + if len(self._failed) > 0: + add_text("%d failed, " % len(self._failed)) + if len(self._failed_doctest) > 0: + add_text("%d failed, " % len(self._failed_doctest)) + if self._skipped > 0: + add_text("%d skipped, " % self._skipped) + if self._xfailed > 0: + add_text("%d expected to fail, " % self._xfailed) + if len(self._xpassed) > 0: + add_text("%d expected to fail but passed, " % len(self._xpassed)) + if len(self._exceptions) > 0: + add_text("%d exceptions, " % len(self._exceptions)) + add_text("in %.2f seconds" % (self._t_end - self._t_start)) + + if self.slow_test_functions: + self.write_center('slowest tests', '_') + sorted_slow = sorted(self.slow_test_functions, key=lambda r: r[1]) + for slow_func_name, taken in sorted_slow: + print('%s - Took %.3f seconds' % (slow_func_name, taken)) + + if self.fast_test_functions: + self.write_center('unexpectedly fast tests', '_') + sorted_fast = sorted(self.fast_test_functions, + key=lambda r: r[1]) + for fast_func_name, taken in sorted_fast: + print('%s - Took %.3f seconds' % (fast_func_name, taken)) + + if len(self._xpassed) > 0: + self.write_center("xpassed tests", "_") + for e in self._xpassed: + self.write("%s: %s\n" % (e[0], e[1])) + self.write("\n") + + if self._tb_style != "no" and len(self._exceptions) > 0: + for e in self._exceptions: + filename, f, (t, val, tb) = e + self.write_center("", "_") + if f is None: + s = "%s" % filename + else: + s = "%s:%s" % (filename, f.__name__) + self.write_center(s, "_") + self.write_exception(t, val, tb) + self.write("\n") + + if self._tb_style != "no" and len(self._failed) > 0: + for e in self._failed: + filename, f, (t, val, tb) = e + self.write_center("", "_") + self.write_center("%s::%s" % (filename, f.__name__), "_") + self.write_exception(t, val, tb) + self.write("\n") + + if self._tb_style != "no" and len(self._failed_doctest) > 0: + for e in self._failed_doctest: + filename, msg = e + self.write_center("", "_") + self.write_center("%s" % filename, "_") + self.write(msg) + self.write("\n") + + self.write_center(text) + ok = len(self._failed) == 0 and len(self._exceptions) == 0 and \ + len(self._failed_doctest) == 0 + if not ok: + self.write("DO *NOT* COMMIT!\n") + return ok + + def entering_filename(self, filename, n): + rel_name = filename[len(self._root_dir) + 1:] + self._active_file = rel_name + self._active_file_error = False + self.write(rel_name) + self.write("[%d] " % n) + + def leaving_filename(self): + self.write(" ") + if self._active_file_error: + self.write("[FAIL]", "Red", align="right") + else: + self.write("[OK]", "Green", align="right") + self.write("\n") + if self._verbose: + self.write("\n") + + def entering_test(self, f): + self._active_f = f + if self._verbose: + self.write("\n" + f.__name__ + " ") + + def test_xfail(self): + self._xfailed += 1 + self.write("f", "Green") + + def test_xpass(self, v): + message = str(v) + self._xpassed.append((self._active_file, message)) + self.write("X", "Green") + + def test_fail(self, exc_info): + self._failed.append((self._active_file, self._active_f, exc_info)) + self.write("F", "Red") + self._active_file_error = True + + def doctest_fail(self, name, error_msg): + # the first line contains "******", remove it: + error_msg = "\n".join(error_msg.split("\n")[1:]) + self._failed_doctest.append((name, error_msg)) + self.write("F", "Red") + self._active_file_error = True + + def test_pass(self, char="."): + self._passed += 1 + if self._verbose: + self.write("ok", "Green") + else: + self.write(char, "Green") + + def test_skip(self, v=None): + char = "s" + self._skipped += 1 + if v is not None: + message = str(v) + if message == "KeyboardInterrupt": + char = "K" + elif message == "Timeout": + char = "T" + elif message == "Slow": + char = "w" + if self._verbose: + if v is not None: + self.write(message + ' ', "Blue") + else: + self.write(" - ", "Blue") + self.write(char, "Blue") + + def test_exception(self, exc_info): + self._exceptions.append((self._active_file, self._active_f, exc_info)) + if exc_info[0] is TimeOutError: + self.write("T", "Red") + else: + self.write("E", "Red") + self._active_file_error = True + + def import_error(self, filename, exc_info): + self._exceptions.append((filename, None, exc_info)) + rel_name = filename[len(self._root_dir) + 1:] + self.write(rel_name) + self.write("[?] Failed to import", "Red") + self.write(" ") + self.write("[FAIL]", "Red", align="right") + self.write("\n") diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/runtests_pytest.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/runtests_pytest.py new file mode 100644 index 0000000000000000000000000000000000000000..635f27864ca86571128e6c9a055199dfbde1ed63 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/runtests_pytest.py @@ -0,0 +1,461 @@ +"""Backwards compatible functions for running tests from SymPy using pytest. + +SymPy historically had its own testing framework that aimed to: +- be compatible with pytest; +- operate similarly (or identically) to pytest; +- not require any external dependencies; +- have all the functionality in one file only; +- have no magic, just import the test file and execute the test functions; and +- be portable. + +To reduce the maintenance burden of developing an independent testing framework +and to leverage the benefits of existing Python testing infrastructure, SymPy +now uses pytest (and various of its plugins) to run the test suite. + +To maintain backwards compatibility with the legacy testing interface of SymPy, +which implemented functions that allowed users to run the tests on their +installed version of SymPy, the functions in this module are implemented to +match the existing API while thinly wrapping pytest. + +These two key functions are `test` and `doctest`. + +""" + +import functools +import importlib.util +import os +import pathlib +import re +from fnmatch import fnmatch +from typing import List, Optional, Tuple + +try: + import pytest +except ImportError: + + class NoPytestError(Exception): + """Raise when an internal test helper function is called with pytest.""" + + class pytest: # type: ignore + """Shadow to support pytest features when pytest can't be imported.""" + + @staticmethod + def main(*args, **kwargs): + msg = 'pytest must be installed to run tests via this function' + raise NoPytestError(msg) + +from sympy.testing.runtests import test as test_sympy + + +TESTPATHS_DEFAULT = ( + pathlib.Path('sympy'), + pathlib.Path('doc', 'src'), +) +BLACKLIST_DEFAULT = ( + 'sympy/integrals/rubi/rubi_tests/tests', +) + + +class PytestPluginManager: + """Module names for pytest plugins used by SymPy.""" + PYTEST: str = 'pytest' + RANDOMLY: str = 'pytest_randomly' + SPLIT: str = 'pytest_split' + TIMEOUT: str = 'pytest_timeout' + XDIST: str = 'xdist' + + @functools.cached_property + def has_pytest(self) -> bool: + return bool(importlib.util.find_spec(self.PYTEST)) + + @functools.cached_property + def has_randomly(self) -> bool: + return bool(importlib.util.find_spec(self.RANDOMLY)) + + @functools.cached_property + def has_split(self) -> bool: + return bool(importlib.util.find_spec(self.SPLIT)) + + @functools.cached_property + def has_timeout(self) -> bool: + return bool(importlib.util.find_spec(self.TIMEOUT)) + + @functools.cached_property + def has_xdist(self) -> bool: + return bool(importlib.util.find_spec(self.XDIST)) + + +split_pattern = re.compile(r'([1-9][0-9]*)/([1-9][0-9]*)') + + +@functools.lru_cache +def sympy_dir() -> pathlib.Path: + """Returns the root SymPy directory.""" + return pathlib.Path(__file__).parents[2] + + +def update_args_with_paths( + paths: List[str], + keywords: Optional[Tuple[str]], + args: List[str], +) -> List[str]: + """Appends valid paths and flags to the args `list` passed to `pytest.main`. + + The are three different types of "path" that a user may pass to the `paths` + positional arguments, all of which need to be handled slightly differently: + + 1. Nothing is passed + The paths to the `testpaths` defined in `pytest.ini` need to be appended + to the arguments list. + 2. Full, valid paths are passed + These paths need to be validated but can then be directly appended to + the arguments list. + 3. Partial paths are passed. + The `testpaths` defined in `pytest.ini` need to be recursed and any + matches be appended to the arguments list. + + """ + + def find_paths_matching_partial(partial_paths): + partial_path_file_patterns = [] + for partial_path in partial_paths: + if len(partial_path) >= 4: + has_test_prefix = partial_path[:4] == 'test' + has_py_suffix = partial_path[-3:] == '.py' + elif len(partial_path) >= 3: + has_test_prefix = False + has_py_suffix = partial_path[-3:] == '.py' + else: + has_test_prefix = False + has_py_suffix = False + if has_test_prefix and has_py_suffix: + partial_path_file_patterns.append(partial_path) + elif has_test_prefix: + partial_path_file_patterns.append(f'{partial_path}*.py') + elif has_py_suffix: + partial_path_file_patterns.append(f'test*{partial_path}') + else: + partial_path_file_patterns.append(f'test*{partial_path}*.py') + matches = [] + for testpath in valid_testpaths_default: + for path, dirs, files in os.walk(testpath, topdown=True): + zipped = zip(partial_paths, partial_path_file_patterns) + for (partial_path, partial_path_file) in zipped: + if fnmatch(path, f'*{partial_path}*'): + matches.append(str(pathlib.Path(path))) + dirs[:] = [] + else: + for file in files: + if fnmatch(file, partial_path_file): + matches.append(str(pathlib.Path(path, file))) + return matches + + def is_tests_file(filepath: str) -> bool: + path = pathlib.Path(filepath) + if not path.is_file(): + return False + if not path.parts[-1].startswith('test_'): + return False + if not path.suffix == '.py': + return False + return True + + def find_tests_matching_keywords(keywords, filepath): + matches = [] + source = pathlib.Path(filepath).read_text(encoding='utf-8') + for line in source.splitlines(): + if line.lstrip().startswith('def '): + for kw in keywords: + if line.lower().find(kw.lower()) != -1: + test_name = line.split(' ')[1].split('(')[0] + full_test_path = filepath + '::' + test_name + matches.append(full_test_path) + return matches + + valid_testpaths_default = [] + for testpath in TESTPATHS_DEFAULT: + absolute_testpath = pathlib.Path(sympy_dir(), testpath) + if absolute_testpath.exists(): + valid_testpaths_default.append(str(absolute_testpath)) + + candidate_paths = [] + if paths: + full_paths = [] + partial_paths = [] + for path in paths: + if pathlib.Path(path).exists(): + full_paths.append(str(pathlib.Path(sympy_dir(), path))) + else: + partial_paths.append(path) + matched_paths = find_paths_matching_partial(partial_paths) + candidate_paths.extend(full_paths) + candidate_paths.extend(matched_paths) + else: + candidate_paths.extend(valid_testpaths_default) + + if keywords is not None and keywords != (): + matches = [] + for path in candidate_paths: + if is_tests_file(path): + test_matches = find_tests_matching_keywords(keywords, path) + matches.extend(test_matches) + else: + for root, dirnames, filenames in os.walk(path): + for filename in filenames: + absolute_filepath = str(pathlib.Path(root, filename)) + if is_tests_file(absolute_filepath): + test_matches = find_tests_matching_keywords( + keywords, + absolute_filepath, + ) + matches.extend(test_matches) + args.extend(matches) + else: + args.extend(candidate_paths) + + return args + + +def make_absolute_path(partial_path: str) -> str: + """Convert a partial path to an absolute path. + + A path such a `sympy/core` might be needed. However, absolute paths should + be used in the arguments to pytest in all cases as it avoids errors that + arise from nonexistent paths. + + This function assumes that partial_paths will be passed in such that they + begin with the explicit `sympy` directory, i.e. `sympy/...`. + + """ + + def is_valid_partial_path(partial_path: str) -> bool: + """Assumption that partial paths are defined from the `sympy` root.""" + return pathlib.Path(partial_path).parts[0] == 'sympy' + + if not is_valid_partial_path(partial_path): + msg = ( + f'Partial path {dir(partial_path)} is invalid, partial paths are ' + f'expected to be defined with the `sympy` directory as the root.' + ) + raise ValueError(msg) + + absolute_path = str(pathlib.Path(sympy_dir(), partial_path)) + return absolute_path + + +def test(*paths, subprocess=True, rerun=0, **kwargs): + """Interface to run tests via pytest compatible with SymPy's test runner. + + Explanation + =========== + + Note that a `pytest.ExitCode`, which is an `enum`, is returned. This is + different to the legacy SymPy test runner which would return a `bool`. If + all tests successfully pass the `pytest.ExitCode.OK` with value `0` is + returned, whereas the legacy SymPy test runner would return `True`. In any + other scenario, a non-zero `enum` value is returned, whereas the legacy + SymPy test runner would return `False`. Users need to, therefore, be careful + if treating the pytest exit codes as booleans because + `bool(pytest.ExitCode.OK)` evaluates to `False`, the opposite of legacy + behaviour. + + Examples + ======== + + >>> import sympy # doctest: +SKIP + + Run one file: + + >>> sympy.test('sympy/core/tests/test_basic.py') # doctest: +SKIP + >>> sympy.test('_basic') # doctest: +SKIP + + Run all tests in sympy/functions/ and some particular file: + + >>> sympy.test("sympy/core/tests/test_basic.py", + ... "sympy/functions") # doctest: +SKIP + + Run all tests in sympy/core and sympy/utilities: + + >>> sympy.test("/core", "/util") # doctest: +SKIP + + Run specific test from a file: + + >>> sympy.test("sympy/core/tests/test_basic.py", + ... kw="test_equality") # doctest: +SKIP + + Run specific test from any file: + + >>> sympy.test(kw="subs") # doctest: +SKIP + + Run the tests using the legacy SymPy runner: + + >>> sympy.test(use_sympy_runner=True) # doctest: +SKIP + + Note that this option is slated for deprecation in the near future and is + only currently provided to ensure users have an alternative option while the + pytest-based runner receives real-world testing. + + Parameters + ========== + paths : first n positional arguments of strings + Paths, both partial and absolute, describing which subset(s) of the test + suite are to be run. + subprocess : bool, default is True + Legacy option, is currently ignored. + rerun : int, default is 0 + Legacy option, is ignored. + use_sympy_runner : bool or None, default is None + Temporary option to invoke the legacy SymPy test runner instead of + `pytest.main`. Will be removed in the near future. + verbose : bool, default is False + Sets the verbosity of the pytest output. Using `True` will add the + `--verbose` option to the pytest call. + tb : str, 'auto', 'long', 'short', 'line', 'native', or 'no' + Sets the traceback print mode of pytest using the `--tb` option. + kw : str + Only run tests which match the given substring expression. An expression + is a Python evaluatable expression where all names are substring-matched + against test names and their parent classes. Example: -k 'test_method or + test_other' matches all test functions and classes whose name contains + 'test_method' or 'test_other', while -k 'not test_method' matches those + that don't contain 'test_method' in their names. -k 'not test_method and + not test_other' will eliminate the matches. Additionally keywords are + matched to classes and functions containing extra names in their + 'extra_keyword_matches' set, as well as functions which have names + assigned directly to them. The matching is case-insensitive. + pdb : bool, default is False + Start the interactive Python debugger on errors or `KeyboardInterrupt`. + colors : bool, default is True + Color terminal output. + force_colors : bool, default is False + Legacy option, is ignored. + sort : bool, default is True + Run the tests in sorted order. pytest uses a sorted test order by + default. Requires pytest-randomly. + seed : int + Seed to use for random number generation. Requires pytest-randomly. + timeout : int, default is 0 + Timeout in seconds before dumping the stacks. 0 means no timeout. + Requires pytest-timeout. + fail_on_timeout : bool, default is False + Legacy option, is currently ignored. + slow : bool, default is False + Run the subset of tests marked as `slow`. + enhance_asserts : bool, default is False + Legacy option, is currently ignored. + split : string in form `/` or None, default is None + Used to split the tests up. As an example, if `split='2/3' is used then + only the middle third of tests are run. Requires pytest-split. + time_balance : bool, default is True + Legacy option, is currently ignored. + blacklist : iterable of test paths as strings, default is BLACKLIST_DEFAULT + Blacklisted test paths are ignored using the `--ignore` option. Paths + may be partial or absolute. If partial then they are matched against + all paths in the pytest tests path. + parallel : bool, default is False + Parallelize the test running using pytest-xdist. If `True` then pytest + will automatically detect the number of CPU cores available and use them + all. Requires pytest-xdist. + store_durations : bool, False + Store test durations into the file `.test_durations`. The is used by + `pytest-split` to help determine more even splits when more than one + test group is being used. Requires pytest-split. + + """ + # NOTE: to be removed alongside SymPy test runner + if kwargs.get('use_sympy_runner', False): + kwargs.pop('parallel', False) + kwargs.pop('store_durations', False) + kwargs.pop('use_sympy_runner', True) + if kwargs.get('slow') is None: + kwargs['slow'] = False + return test_sympy(*paths, subprocess=True, rerun=0, **kwargs) + + pytest_plugin_manager = PytestPluginManager() + if not pytest_plugin_manager.has_pytest: + pytest.main() + + args = [] + + if kwargs.get('verbose', False): + args.append('--verbose') + + if tb := kwargs.get('tb'): + args.extend(['--tb', tb]) + + if kwargs.get('pdb'): + args.append('--pdb') + + if not kwargs.get('colors', True): + args.extend(['--color', 'no']) + + if seed := kwargs.get('seed'): + if not pytest_plugin_manager.has_randomly: + msg = '`pytest-randomly` plugin required to control random seed.' + raise ModuleNotFoundError(msg) + args.extend(['--randomly-seed', str(seed)]) + + if kwargs.get('sort', True) and pytest_plugin_manager.has_randomly: + args.append('--randomly-dont-reorganize') + elif not kwargs.get('sort', True) and not pytest_plugin_manager.has_randomly: + msg = '`pytest-randomly` plugin required to randomize test order.' + raise ModuleNotFoundError(msg) + + if timeout := kwargs.get('timeout', None): + if not pytest_plugin_manager.has_timeout: + msg = '`pytest-timeout` plugin required to apply timeout to tests.' + raise ModuleNotFoundError(msg) + args.extend(['--timeout', str(int(timeout))]) + + # Skip slow tests by default and always skip tooslow tests + if kwargs.get('slow', False): + args.extend(['-m', 'slow and not tooslow']) + else: + args.extend(['-m', 'not slow and not tooslow']) + + if (split := kwargs.get('split')) is not None: + if not pytest_plugin_manager.has_split: + msg = '`pytest-split` plugin required to run tests as groups.' + raise ModuleNotFoundError(msg) + match = split_pattern.match(split) + if not match: + msg = ('split must be a string of the form a/b where a and b are ' + 'positive nonzero ints') + raise ValueError(msg) + group, splits = map(str, match.groups()) + args.extend(['--group', group, '--splits', splits]) + if group > splits: + msg = (f'cannot have a group number {group} with only {splits} ' + 'splits') + raise ValueError(msg) + + if blacklist := kwargs.get('blacklist', BLACKLIST_DEFAULT): + for path in blacklist: + args.extend(['--ignore', make_absolute_path(path)]) + + if kwargs.get('parallel', False): + if not pytest_plugin_manager.has_xdist: + msg = '`pytest-xdist` plugin required to run tests in parallel.' + raise ModuleNotFoundError(msg) + args.extend(['-n', 'auto']) + + if kwargs.get('store_durations', False): + if not pytest_plugin_manager.has_split: + msg = '`pytest-split` plugin required to store test durations.' + raise ModuleNotFoundError(msg) + args.append('--store-durations') + + if (keywords := kwargs.get('kw')) is not None: + keywords = tuple(str(kw) for kw in keywords) + else: + keywords = () + + args = update_args_with_paths(paths, keywords, args) + exit_code = pytest.main(args) + return exit_code + + +def doctest(): + """Interface to run doctests via pytest compatible with SymPy's test runner. + """ + raise NotImplementedError diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/__init__.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/diagnose_imports.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/diagnose_imports.py new file mode 100644 index 0000000000000000000000000000000000000000..a31b66c66690c082800ae36eee37dad6927e0b37 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/diagnose_imports.py @@ -0,0 +1,216 @@ +#!/usr/bin/env python + +""" +Import diagnostics. Run bin/diagnose_imports.py --help for details. +""" + +from __future__ import annotations + +if __name__ == "__main__": + + import sys + import inspect + import builtins + + import optparse + + from os.path import abspath, dirname, join, normpath + this_file = abspath(__file__) + sympy_dir = join(dirname(this_file), '..', '..', '..') + sympy_dir = normpath(sympy_dir) + sys.path.insert(0, sympy_dir) + + option_parser = optparse.OptionParser( + usage= + "Usage: %prog option [options]\n" + "\n" + "Import analysis for imports between SymPy modules.") + option_group = optparse.OptionGroup( + option_parser, + 'Analysis options', + 'Options that define what to do. Exactly one of these must be given.') + option_group.add_option( + '--problems', + help= + 'Print all import problems, that is: ' + 'If an import pulls in a package instead of a module ' + '(e.g. sympy.core instead of sympy.core.add); ' # see ##PACKAGE## + 'if it imports a symbol that is already present; ' # see ##DUPLICATE## + 'if it imports a symbol ' + 'from somewhere other than the defining module.', # see ##ORIGIN## + action='count') + option_group.add_option( + '--origins', + help= + 'For each imported symbol in each module, ' + 'print the module that defined it. ' + '(This is useful for import refactoring.)', + action='count') + option_parser.add_option_group(option_group) + option_group = optparse.OptionGroup( + option_parser, + 'Sort options', + 'These options define the sort order for output lines. ' + 'At most one of these options is allowed. ' + 'Unsorted output will reflect the order in which imports happened.') + option_group.add_option( + '--by-importer', + help='Sort output lines by name of importing module.', + action='count') + option_group.add_option( + '--by-origin', + help='Sort output lines by name of imported module.', + action='count') + option_parser.add_option_group(option_group) + (options, args) = option_parser.parse_args() + if args: + option_parser.error( + 'Unexpected arguments %s (try %s --help)' % (args, sys.argv[0])) + if options.problems > 1: + option_parser.error('--problems must not be given more than once.') + if options.origins > 1: + option_parser.error('--origins must not be given more than once.') + if options.by_importer > 1: + option_parser.error('--by-importer must not be given more than once.') + if options.by_origin > 1: + option_parser.error('--by-origin must not be given more than once.') + options.problems = options.problems == 1 + options.origins = options.origins == 1 + options.by_importer = options.by_importer == 1 + options.by_origin = options.by_origin == 1 + if not options.problems and not options.origins: + option_parser.error( + 'At least one of --problems and --origins is required') + if options.problems and options.origins: + option_parser.error( + 'At most one of --problems and --origins is allowed') + if options.by_importer and options.by_origin: + option_parser.error( + 'At most one of --by-importer and --by-origin is allowed') + options.by_process = not options.by_importer and not options.by_origin + + builtin_import = builtins.__import__ + + class Definition: + """Information about a symbol's definition.""" + def __init__(self, name, value, definer): + self.name = name + self.value = value + self.definer = definer + def __hash__(self): + return hash(self.name) + def __eq__(self, other): + return self.name == other.name and self.value == other.value + def __ne__(self, other): + return not (self == other) + def __repr__(self): + return 'Definition(%s, ..., %s)' % ( + repr(self.name), repr(self.definer)) + + # Maps each function/variable to name of module to define it + symbol_definers: dict[Definition, str] = {} + + def in_module(a, b): + """Is a the same module as or a submodule of b?""" + return a == b or a != None and b != None and a.startswith(b + '.') + + def relevant(module): + """Is module relevant for import checking? + + Only imports between relevant modules will be checked.""" + return in_module(module, 'sympy') + + sorted_messages = [] + + def msg(msg, *args): + if options.by_process: + print(msg % args) + else: + sorted_messages.append(msg % args) + + def tracking_import(module, globals=globals(), locals=[], fromlist=None, level=-1): + """__import__ wrapper - does not change imports at all, but tracks them. + + Default order is implemented by doing output directly. + All other orders are implemented by collecting output information into + a sorted list that will be emitted after all imports are processed. + + Indirect imports can only occur after the requested symbol has been + imported directly (because the indirect import would not have a module + to pick the symbol up from). + So this code detects indirect imports by checking whether the symbol in + question was already imported. + + Keeps the semantics of __import__ unchanged.""" + caller_frame = inspect.getframeinfo(sys._getframe(1)) + importer_filename = caller_frame.filename + importer_module = globals['__name__'] + if importer_filename == caller_frame.filename: + importer_reference = '%s line %s' % ( + importer_filename, str(caller_frame.lineno)) + else: + importer_reference = importer_filename + result = builtin_import(module, globals, locals, fromlist, level) + importee_module = result.__name__ + # We're only interested if importer and importee are in SymPy + if relevant(importer_module) and relevant(importee_module): + for symbol in result.__dict__.iterkeys(): + definition = Definition( + symbol, result.__dict__[symbol], importer_module) + if definition not in symbol_definers: + symbol_definers[definition] = importee_module + if hasattr(result, '__path__'): + ##PACKAGE## + # The existence of __path__ is documented in the tutorial on modules. + # Python 3.3 documents this in http://docs.python.org/3.3/reference/import.html + if options.by_origin: + msg('Error: %s (a package) is imported by %s', + module, importer_reference) + else: + msg('Error: %s contains package import %s', + importer_reference, module) + if fromlist != None: + symbol_list = fromlist + if '*' in symbol_list: + if (importer_filename.endswith(("__init__.py", "__init__.pyc", "__init__.pyo"))): + # We do not check starred imports inside __init__ + # That's the normal "please copy over its imports to my namespace" + symbol_list = [] + else: + symbol_list = result.__dict__.iterkeys() + for symbol in symbol_list: + if symbol not in result.__dict__: + if options.by_origin: + msg('Error: %s.%s is not defined (yet), but %s tries to import it', + importee_module, symbol, importer_reference) + else: + msg('Error: %s tries to import %s.%s, which did not define it (yet)', + importer_reference, importee_module, symbol) + else: + definition = Definition( + symbol, result.__dict__[symbol], importer_module) + symbol_definer = symbol_definers[definition] + if symbol_definer == importee_module: + ##DUPLICATE## + if options.by_origin: + msg('Error: %s.%s is imported again into %s', + importee_module, symbol, importer_reference) + else: + msg('Error: %s imports %s.%s again', + importer_reference, importee_module, symbol) + else: + ##ORIGIN## + if options.by_origin: + msg('Error: %s.%s is imported by %s, which should import %s.%s instead', + importee_module, symbol, importer_reference, symbol_definer, symbol) + else: + msg('Error: %s imports %s.%s but should import %s.%s instead', + importer_reference, importee_module, symbol, symbol_definer, symbol) + return result + + builtins.__import__ = tracking_import + __import__('sympy') + + sorted_messages.sort() + for message in sorted_messages: + print(message) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/test_code_quality.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/test_code_quality.py new file mode 100644 index 0000000000000000000000000000000000000000..9a9f363f0b9a802553f8643186b7d858d1ad0694 --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/test_code_quality.py @@ -0,0 +1,510 @@ +# coding=utf-8 +from os import walk, sep, pardir +from os.path import split, join, abspath, exists, isfile +from glob import glob +import re +import random +import ast + +from sympy.testing.pytest import raises +from sympy.testing.quality_unicode import _test_this_file_encoding + +# System path separator (usually slash or backslash) to be +# used with excluded files, e.g. +# exclude = set([ +# "%(sep)smpmath%(sep)s" % sepd, +# ]) +sepd = {"sep": sep} + +# path and sympy_path +SYMPY_PATH = abspath(join(split(__file__)[0], pardir, pardir)) # go to sympy/ +assert exists(SYMPY_PATH) + +TOP_PATH = abspath(join(SYMPY_PATH, pardir)) +BIN_PATH = join(TOP_PATH, "bin") +EXAMPLES_PATH = join(TOP_PATH, "examples") + +# Error messages +message_space = "File contains trailing whitespace: %s, line %s." +message_implicit = "File contains an implicit import: %s, line %s." +message_tabs = "File contains tabs instead of spaces: %s, line %s." +message_carriage = "File contains carriage returns at end of line: %s, line %s" +message_str_raise = "File contains string exception: %s, line %s" +message_gen_raise = "File contains generic exception: %s, line %s" +message_old_raise = "File contains old-style raise statement: %s, line %s, \"%s\"" +message_eof = "File does not end with a newline: %s, line %s" +message_multi_eof = "File ends with more than 1 newline: %s, line %s" +message_test_suite_def = "Function should start with 'test_' or '_': %s, line %s" +message_duplicate_test = "This is a duplicate test function: %s, line %s" +message_self_assignments = "File contains assignments to self/cls: %s, line %s." +message_func_is = "File contains '.func is': %s, line %s." +message_bare_expr = "File contains bare expression: %s, line %s." + +implicit_test_re = re.compile(r'^\s*(>>> )?(\.\.\. )?from .* import .*\*') +str_raise_re = re.compile( + r'^\s*(>>> )?(\.\.\. )?raise(\s+(\'|\")|\s*(\(\s*)+(\'|\"))') +gen_raise_re = re.compile( + r'^\s*(>>> )?(\.\.\. )?raise(\s+Exception|\s*(\(\s*)+Exception)') +old_raise_re = re.compile(r'^\s*(>>> )?(\.\.\. )?raise((\s*\(\s*)|\s+)\w+\s*,') +test_suite_def_re = re.compile(r'^def\s+(?!(_|test))[^(]*\(\s*\)\s*:$') +test_ok_def_re = re.compile(r'^def\s+test_.*:$') +test_file_re = re.compile(r'.*[/\\]test_.*\.py$') +func_is_re = re.compile(r'\.\s*func\s+is') + + +def tab_in_leading(s): + """Returns True if there are tabs in the leading whitespace of a line, + including the whitespace of docstring code samples.""" + n = len(s) - len(s.lstrip()) + if not s[n:n + 3] in ['...', '>>>']: + check = s[:n] + else: + smore = s[n + 3:] + check = s[:n] + smore[:len(smore) - len(smore.lstrip())] + return not (check.expandtabs() == check) + + +def find_self_assignments(s): + """Returns a list of "bad" assignments: if there are instances + of assigning to the first argument of the class method (except + for staticmethod's). + """ + t = [n for n in ast.parse(s).body if isinstance(n, ast.ClassDef)] + + bad = [] + for c in t: + for n in c.body: + if not isinstance(n, ast.FunctionDef): + continue + if any(d.id == 'staticmethod' + for d in n.decorator_list if isinstance(d, ast.Name)): + continue + if n.name == '__new__': + continue + if not n.args.args: + continue + first_arg = n.args.args[0].arg + + for m in ast.walk(n): + if isinstance(m, ast.Assign): + for a in m.targets: + if isinstance(a, ast.Name) and a.id == first_arg: + bad.append(m) + elif (isinstance(a, ast.Tuple) and + any(q.id == first_arg for q in a.elts + if isinstance(q, ast.Name))): + bad.append(m) + + return bad + + +def check_directory_tree(base_path, file_check, exclusions=set(), pattern="*.py"): + """ + Checks all files in the directory tree (with base_path as starting point) + with the file_check function provided, skipping files that contain + any of the strings in the set provided by exclusions. + """ + if not base_path: + return + for root, dirs, files in walk(base_path): + check_files(glob(join(root, pattern)), file_check, exclusions) + + +def check_files(files, file_check, exclusions=set(), pattern=None): + """ + Checks all files with the file_check function provided, skipping files + that contain any of the strings in the set provided by exclusions. + """ + if not files: + return + for fname in files: + if not exists(fname) or not isfile(fname): + continue + if any(ex in fname for ex in exclusions): + continue + if pattern is None or re.match(pattern, fname): + file_check(fname) + + +class _Visit(ast.NodeVisitor): + """return the line number corresponding to the + line on which a bare expression appears if it is a binary op + or a comparison that is not in a with block. + + EXAMPLES + ======== + + >>> import ast + >>> class _Visit(ast.NodeVisitor): + ... def visit_Expr(self, node): + ... if isinstance(node.value, (ast.BinOp, ast.Compare)): + ... print(node.lineno) + ... def visit_With(self, node): + ... pass # no checking there + ... + >>> code='''x = 1 # line 1 + ... for i in range(3): + ... x == 2 # <-- 3 + ... if x == 2: + ... x == 3 # <-- 5 + ... x + 1 # <-- 6 + ... x = 1 + ... if x == 1: + ... print(1) + ... while x != 1: + ... x == 1 # <-- 11 + ... with raises(TypeError): + ... c == 1 + ... raise TypeError + ... assert x == 1 + ... ''' + >>> _Visit().visit(ast.parse(code)) + 3 + 5 + 6 + 11 + """ + def visit_Expr(self, node): + if isinstance(node.value, (ast.BinOp, ast.Compare)): + assert None, message_bare_expr % ('', node.lineno) + def visit_With(self, node): + pass + + +BareExpr = _Visit() + + +def line_with_bare_expr(code): + """return None or else 0-based line number of code on which + a bare expression appeared. + """ + tree = ast.parse(code) + try: + BareExpr.visit(tree) + except AssertionError as msg: + assert msg.args + msg = msg.args[0] + assert msg.startswith(message_bare_expr.split(':', 1)[0]) + return int(msg.rsplit(' ', 1)[1].rstrip('.')) # the line number + + +def test_files(): + """ + This test tests all files in SymPy and checks that: + o no lines contains a trailing whitespace + o no lines end with \r\n + o no line uses tabs instead of spaces + o that the file ends with a single newline + o there are no general or string exceptions + o there are no old style raise statements + o name of arg-less test suite functions start with _ or test_ + o no duplicate function names that start with test_ + o no assignments to self variable in class methods + o no lines contain ".func is" except in the test suite + o there is no do-nothing expression like `a == b` or `x + 1` + """ + + def test(fname): + with open(fname, encoding="utf8") as test_file: + test_this_file(fname, test_file) + with open(fname, encoding='utf8') as test_file: + _test_this_file_encoding(fname, test_file) + + def test_this_file(fname, test_file): + idx = None + code = test_file.read() + test_file.seek(0) # restore reader to head + py = fname if sep not in fname else fname.rsplit(sep, 1)[-1] + if py.startswith('test_'): + idx = line_with_bare_expr(code) + if idx is not None: + assert False, message_bare_expr % (fname, idx + 1) + + line = None # to flag the case where there were no lines in file + tests = 0 + test_set = set() + for idx, line in enumerate(test_file): + if test_file_re.match(fname): + if test_suite_def_re.match(line): + assert False, message_test_suite_def % (fname, idx + 1) + if test_ok_def_re.match(line): + tests += 1 + test_set.add(line[3:].split('(')[0].strip()) + if len(test_set) != tests: + assert False, message_duplicate_test % (fname, idx + 1) + if line.endswith((" \n", "\t\n")): + assert False, message_space % (fname, idx + 1) + if line.endswith("\r\n"): + assert False, message_carriage % (fname, idx + 1) + if tab_in_leading(line): + assert False, message_tabs % (fname, idx + 1) + if str_raise_re.search(line): + assert False, message_str_raise % (fname, idx + 1) + if gen_raise_re.search(line): + assert False, message_gen_raise % (fname, idx + 1) + if (implicit_test_re.search(line) and + not list(filter(lambda ex: ex in fname, import_exclude))): + assert False, message_implicit % (fname, idx + 1) + if func_is_re.search(line) and not test_file_re.search(fname): + assert False, message_func_is % (fname, idx + 1) + + result = old_raise_re.search(line) + + if result is not None: + assert False, message_old_raise % ( + fname, idx + 1, result.group(2)) + + if line is not None: + if line == '\n' and idx > 0: + assert False, message_multi_eof % (fname, idx + 1) + elif not line.endswith('\n'): + # eof newline check + assert False, message_eof % (fname, idx + 1) + + + # Files to test at top level + top_level_files = [join(TOP_PATH, file) for file in [ + "isympy.py", + "build.py", + "setup.py", + ]] + # Files to exclude from all tests + exclude = { + "%(sep)ssympy%(sep)sparsing%(sep)sautolev%(sep)s_antlr%(sep)sautolevparser.py" % sepd, + "%(sep)ssympy%(sep)sparsing%(sep)sautolev%(sep)s_antlr%(sep)sautolevlexer.py" % sepd, + "%(sep)ssympy%(sep)sparsing%(sep)sautolev%(sep)s_antlr%(sep)sautolevlistener.py" % sepd, + "%(sep)ssympy%(sep)sparsing%(sep)slatex%(sep)s_antlr%(sep)slatexparser.py" % sepd, + "%(sep)ssympy%(sep)sparsing%(sep)slatex%(sep)s_antlr%(sep)slatexlexer.py" % sepd, + } + # Files to exclude from the implicit import test + import_exclude = { + # glob imports are allowed in top-level __init__.py: + "%(sep)ssympy%(sep)s__init__.py" % sepd, + # these __init__.py should be fixed: + # XXX: not really, they use useful import pattern (DRY) + "%(sep)svector%(sep)s__init__.py" % sepd, + "%(sep)smechanics%(sep)s__init__.py" % sepd, + "%(sep)squantum%(sep)s__init__.py" % sepd, + "%(sep)spolys%(sep)s__init__.py" % sepd, + "%(sep)spolys%(sep)sdomains%(sep)s__init__.py" % sepd, + # interactive SymPy executes ``from sympy import *``: + "%(sep)sinteractive%(sep)ssession.py" % sepd, + # isympy.py executes ``from sympy import *``: + "%(sep)sisympy.py" % sepd, + # these two are import timing tests: + "%(sep)sbin%(sep)ssympy_time.py" % sepd, + "%(sep)sbin%(sep)ssympy_time_cache.py" % sepd, + # Taken from Python stdlib: + "%(sep)sparsing%(sep)ssympy_tokenize.py" % sepd, + # this one should be fixed: + "%(sep)splotting%(sep)spygletplot%(sep)s" % sepd, + # False positive in the docstring + "%(sep)sbin%(sep)stest_external_imports.py" % sepd, + "%(sep)sbin%(sep)stest_submodule_imports.py" % sepd, + # These are deprecated stubs that can be removed at some point: + "%(sep)sutilities%(sep)sruntests.py" % sepd, + "%(sep)sutilities%(sep)spytest.py" % sepd, + "%(sep)sutilities%(sep)srandtest.py" % sepd, + "%(sep)sutilities%(sep)stmpfiles.py" % sepd, + "%(sep)sutilities%(sep)squality_unicode.py" % sepd, + } + check_files(top_level_files, test) + check_directory_tree(BIN_PATH, test, {"~", ".pyc", ".sh"}, "*") + check_directory_tree(SYMPY_PATH, test, exclude) + check_directory_tree(EXAMPLES_PATH, test, exclude) + + +def _with_space(c): + # return c with a random amount of leading space + return random.randint(0, 10)*' ' + c + + +def test_raise_statement_regular_expression(): + candidates_ok = [ + "some text # raise Exception, 'text'", + "raise ValueError('text') # raise Exception, 'text'", + "raise ValueError('text')", + "raise ValueError", + "raise ValueError('text')", + "raise ValueError('text') #,", + # Talking about an exception in a docstring + ''''"""This function will raise ValueError, except when it doesn't"""''', + "raise (ValueError('text')", + ] + str_candidates_fail = [ + "raise 'exception'", + "raise 'Exception'", + 'raise "exception"', + 'raise "Exception"', + "raise 'ValueError'", + ] + gen_candidates_fail = [ + "raise Exception('text') # raise Exception, 'text'", + "raise Exception('text')", + "raise Exception", + "raise Exception('text')", + "raise Exception('text') #,", + "raise Exception, 'text'", + "raise Exception, 'text' # raise Exception('text')", + "raise Exception, 'text' # raise Exception, 'text'", + ">>> raise Exception, 'text'", + ">>> raise Exception, 'text' # raise Exception('text')", + ">>> raise Exception, 'text' # raise Exception, 'text'", + ] + old_candidates_fail = [ + "raise Exception, 'text'", + "raise Exception, 'text' # raise Exception('text')", + "raise Exception, 'text' # raise Exception, 'text'", + ">>> raise Exception, 'text'", + ">>> raise Exception, 'text' # raise Exception('text')", + ">>> raise Exception, 'text' # raise Exception, 'text'", + "raise ValueError, 'text'", + "raise ValueError, 'text' # raise Exception('text')", + "raise ValueError, 'text' # raise Exception, 'text'", + ">>> raise ValueError, 'text'", + ">>> raise ValueError, 'text' # raise Exception('text')", + ">>> raise ValueError, 'text' # raise Exception, 'text'", + "raise(ValueError,", + "raise (ValueError,", + "raise( ValueError,", + "raise ( ValueError,", + "raise(ValueError ,", + "raise (ValueError ,", + "raise( ValueError ,", + "raise ( ValueError ,", + ] + + for c in candidates_ok: + assert str_raise_re.search(_with_space(c)) is None, c + assert gen_raise_re.search(_with_space(c)) is None, c + assert old_raise_re.search(_with_space(c)) is None, c + for c in str_candidates_fail: + assert str_raise_re.search(_with_space(c)) is not None, c + for c in gen_candidates_fail: + assert gen_raise_re.search(_with_space(c)) is not None, c + for c in old_candidates_fail: + assert old_raise_re.search(_with_space(c)) is not None, c + + +def test_implicit_imports_regular_expression(): + candidates_ok = [ + "from sympy import something", + ">>> from sympy import something", + "from sympy.somewhere import something", + ">>> from sympy.somewhere import something", + "import sympy", + ">>> import sympy", + "import sympy.something.something", + "... import sympy", + "... import sympy.something.something", + "... from sympy import something", + "... from sympy.somewhere import something", + ">> from sympy import *", # To allow 'fake' docstrings + "# from sympy import *", + "some text # from sympy import *", + ] + candidates_fail = [ + "from sympy import *", + ">>> from sympy import *", + "from sympy.somewhere import *", + ">>> from sympy.somewhere import *", + "... from sympy import *", + "... from sympy.somewhere import *", + ] + for c in candidates_ok: + assert implicit_test_re.search(_with_space(c)) is None, c + for c in candidates_fail: + assert implicit_test_re.search(_with_space(c)) is not None, c + + +def test_test_suite_defs(): + candidates_ok = [ + " def foo():\n", + "def foo(arg):\n", + "def _foo():\n", + "def test_foo():\n", + ] + candidates_fail = [ + "def foo():\n", + "def foo() :\n", + "def foo( ):\n", + "def foo():\n", + ] + for c in candidates_ok: + assert test_suite_def_re.search(c) is None, c + for c in candidates_fail: + assert test_suite_def_re.search(c) is not None, c + + +def test_test_duplicate_defs(): + candidates_ok = [ + "def foo():\ndef foo():\n", + "def test():\ndef test_():\n", + "def test_():\ndef test__():\n", + ] + candidates_fail = [ + "def test_():\ndef test_ ():\n", + "def test_1():\ndef test_1():\n", + ] + ok = (None, 'check') + def check(file): + tests = 0 + test_set = set() + for idx, line in enumerate(file.splitlines()): + if test_ok_def_re.match(line): + tests += 1 + test_set.add(line[3:].split('(')[0].strip()) + if len(test_set) != tests: + return False, message_duplicate_test % ('check', idx + 1) + return None, 'check' + for c in candidates_ok: + assert check(c) == ok + for c in candidates_fail: + assert check(c) != ok + + +def test_find_self_assignments(): + candidates_ok = [ + "class A(object):\n def foo(self, arg): arg = self\n", + "class A(object):\n def foo(self, arg): self.prop = arg\n", + "class A(object):\n def foo(self, arg): obj, obj2 = arg, self\n", + "class A(object):\n @classmethod\n def bar(cls, arg): arg = cls\n", + "class A(object):\n def foo(var, arg): arg = var\n", + ] + candidates_fail = [ + "class A(object):\n def foo(self, arg): self = arg\n", + "class A(object):\n def foo(self, arg): obj, self = arg, arg\n", + "class A(object):\n def foo(self, arg):\n if arg: self = arg", + "class A(object):\n @classmethod\n def foo(cls, arg): cls = arg\n", + "class A(object):\n def foo(var, arg): var = arg\n", + ] + + for c in candidates_ok: + assert find_self_assignments(c) == [] + for c in candidates_fail: + assert find_self_assignments(c) != [] + + +def test_test_unicode_encoding(): + unicode_whitelist = ['foo'] + unicode_strict_whitelist = ['bar'] + + fname = 'abc' + test_file = ['α'] + raises(AssertionError, lambda: _test_this_file_encoding( + fname, test_file, unicode_whitelist, unicode_strict_whitelist)) + + fname = 'abc' + test_file = ['abc'] + _test_this_file_encoding( + fname, test_file, unicode_whitelist, unicode_strict_whitelist) + + fname = 'foo' + test_file = ['abc'] + raises(AssertionError, lambda: _test_this_file_encoding( + fname, test_file, unicode_whitelist, unicode_strict_whitelist)) + + fname = 'bar' + test_file = ['abc'] + _test_this_file_encoding( + fname, test_file, unicode_whitelist, unicode_strict_whitelist) diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/test_deprecated.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/test_deprecated.py new file mode 100644 index 0000000000000000000000000000000000000000..696933d96d6232ea869da1002ec9ebee5309724d --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tests/test_deprecated.py @@ -0,0 +1,5 @@ +from sympy.testing.pytest import warns_deprecated_sympy + +def test_deprecated_testing_randtest(): + with warns_deprecated_sympy(): + import sympy.testing.randtest # noqa:F401 diff --git a/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tmpfiles.py b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tmpfiles.py new file mode 100644 index 0000000000000000000000000000000000000000..1d5c69cb58aa11f77679855f3df21f03a10d3b2b --- /dev/null +++ b/miniconda3/envs/ladir/lib/python3.10/site-packages/sympy/testing/tmpfiles.py @@ -0,0 +1,46 @@ +""" +This module adds context manager for temporary files generated by the tests. +""" + +import shutil +import os + + +class TmpFileManager: + """ + A class to track record of every temporary files created by the tests. + """ + tmp_files = set('') + tmp_folders = set('') + + @classmethod + def tmp_file(cls, name=''): + cls.tmp_files.add(name) + return name + + @classmethod + def tmp_folder(cls, name=''): + cls.tmp_folders.add(name) + return name + + @classmethod + def cleanup(cls): + while cls.tmp_files: + file = cls.tmp_files.pop() + if os.path.isfile(file): + os.remove(file) + while cls.tmp_folders: + folder = cls.tmp_folders.pop() + shutil.rmtree(folder) + +def cleanup_tmp_files(test_func): + """ + A decorator to help test codes remove temporary files after the tests. + """ + def wrapper_function(): + try: + test_func() + finally: + TmpFileManager.cleanup() + + return wrapper_function