diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/assortativity/__pycache__/pairs.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/algorithms/assortativity/__pycache__/pairs.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..95f5b9376d59dc421388986169f7ef204990315d Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/algorithms/assortativity/__pycache__/pairs.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/coloring/equitable_coloring.py b/janus/lib/python3.10/site-packages/networkx/algorithms/coloring/equitable_coloring.py new file mode 100644 index 0000000000000000000000000000000000000000..e464a07447045fcdaa8e7ca4ea56552fb00e2826 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/algorithms/coloring/equitable_coloring.py @@ -0,0 +1,505 @@ +""" +Equitable coloring of graphs with bounded degree. +""" + +from collections import defaultdict + +import networkx as nx + +__all__ = ["equitable_color"] + + +@nx._dispatchable +def is_coloring(G, coloring): + """Determine if the coloring is a valid coloring for the graph G.""" + # Verify that the coloring is valid. + return all(coloring[s] != coloring[d] for s, d in G.edges) + + +@nx._dispatchable +def is_equitable(G, coloring, num_colors=None): + """Determines if the coloring is valid and equitable for the graph G.""" + + if not is_coloring(G, coloring): + return False + + # Verify whether it is equitable. + color_set_size = defaultdict(int) + for color in coloring.values(): + color_set_size[color] += 1 + + if num_colors is not None: + for color in range(num_colors): + if color not in color_set_size: + # These colors do not have any vertices attached to them. + color_set_size[color] = 0 + + # If there are more than 2 distinct values, the coloring cannot be equitable + all_set_sizes = set(color_set_size.values()) + if len(all_set_sizes) == 0 and num_colors is None: # Was an empty graph + return True + elif len(all_set_sizes) == 1: + return True + elif len(all_set_sizes) == 2: + a, b = list(all_set_sizes) + return abs(a - b) <= 1 + else: # len(all_set_sizes) > 2: + return False + + +def make_C_from_F(F): + C = defaultdict(list) + for node, color in F.items(): + C[color].append(node) + + return C + + +def make_N_from_L_C(L, C): + nodes = L.keys() + colors = C.keys() + return { + (node, color): sum(1 for v in L[node] if v in C[color]) + for node in nodes + for color in colors + } + + +def make_H_from_C_N(C, N): + return { + (c1, c2): sum(1 for node in C[c1] if N[(node, c2)] == 0) for c1 in C for c2 in C + } + + +def change_color(u, X, Y, N, H, F, C, L): + """Change the color of 'u' from X to Y and update N, H, F, C.""" + assert F[u] == X and X != Y + + # Change the class of 'u' from X to Y + F[u] = Y + + for k in C: + # 'u' witnesses an edge from k -> Y instead of from k -> X now. + if N[u, k] == 0: + H[(X, k)] -= 1 + H[(Y, k)] += 1 + + for v in L[u]: + # 'v' has lost a neighbor in X and gained one in Y + N[(v, X)] -= 1 + N[(v, Y)] += 1 + + if N[(v, X)] == 0: + # 'v' witnesses F[v] -> X + H[(F[v], X)] += 1 + + if N[(v, Y)] == 1: + # 'v' no longer witnesses F[v] -> Y + H[(F[v], Y)] -= 1 + + C[X].remove(u) + C[Y].append(u) + + +def move_witnesses(src_color, dst_color, N, H, F, C, T_cal, L): + """Move witness along a path from src_color to dst_color.""" + X = src_color + while X != dst_color: + Y = T_cal[X] + # Move _any_ witness from X to Y = T_cal[X] + w = next(x for x in C[X] if N[(x, Y)] == 0) + change_color(w, X, Y, N=N, H=H, F=F, C=C, L=L) + X = Y + + +@nx._dispatchable(mutates_input=True) +def pad_graph(G, num_colors): + """Add a disconnected complete clique K_p such that the number of nodes in + the graph becomes a multiple of `num_colors`. + + Assumes that the graph's nodes are labelled using integers. + + Returns the number of nodes with each color. + """ + + n_ = len(G) + r = num_colors - 1 + + # Ensure that the number of nodes in G is a multiple of (r + 1) + s = n_ // (r + 1) + if n_ != s * (r + 1): + p = (r + 1) - n_ % (r + 1) + s += 1 + + # Complete graph K_p between (imaginary) nodes [n_, ... , n_ + p] + K = nx.relabel_nodes(nx.complete_graph(p), {idx: idx + n_ for idx in range(p)}) + G.add_edges_from(K.edges) + + return s + + +def procedure_P(V_minus, V_plus, N, H, F, C, L, excluded_colors=None): + """Procedure P as described in the paper.""" + + if excluded_colors is None: + excluded_colors = set() + + A_cal = set() + T_cal = {} + R_cal = [] + + # BFS to determine A_cal, i.e. colors reachable from V- + reachable = [V_minus] + marked = set(reachable) + idx = 0 + + while idx < len(reachable): + pop = reachable[idx] + idx += 1 + + A_cal.add(pop) + R_cal.append(pop) + + # TODO: Checking whether a color has been visited can be made faster by + # using a look-up table instead of testing for membership in a set by a + # logarithmic factor. + next_layer = [] + for k in C: + if ( + H[(k, pop)] > 0 + and k not in A_cal + and k not in excluded_colors + and k not in marked + ): + next_layer.append(k) + + for dst in next_layer: + # Record that `dst` can reach `pop` + T_cal[dst] = pop + + marked.update(next_layer) + reachable.extend(next_layer) + + # Variables for the algorithm + b = len(C) - len(A_cal) + + if V_plus in A_cal: + # Easy case: V+ is in A_cal + # Move one node from V+ to V- using T_cal to find the parents. + move_witnesses(V_plus, V_minus, N=N, H=H, F=F, C=C, T_cal=T_cal, L=L) + else: + # If there is a solo edge, we can resolve the situation by + # moving witnesses from B to A, making G[A] equitable and then + # recursively balancing G[B - w] with a different V_minus and + # but the same V_plus. + + A_0 = set() + A_cal_0 = set() + num_terminal_sets_found = 0 + made_equitable = False + + for W_1 in R_cal[::-1]: + for v in C[W_1]: + X = None + + for U in C: + if N[(v, U)] == 0 and U in A_cal and U != W_1: + X = U + + # v does not witness an edge in H[A_cal] + if X is None: + continue + + for U in C: + # Note: Departing from the paper here. + if N[(v, U)] >= 1 and U not in A_cal: + X_prime = U + w = v + + try: + # Finding the solo neighbor of w in X_prime + y = next( + node + for node in L[w] + if F[node] == X_prime and N[(node, W_1)] == 1 + ) + except StopIteration: + pass + else: + W = W_1 + + # Move w from W to X, now X has one extra node. + change_color(w, W, X, N=N, H=H, F=F, C=C, L=L) + + # Move witness from X to V_minus, making the coloring + # equitable. + move_witnesses( + src_color=X, + dst_color=V_minus, + N=N, + H=H, + F=F, + C=C, + T_cal=T_cal, + L=L, + ) + + # Move y from X_prime to W, making W the correct size. + change_color(y, X_prime, W, N=N, H=H, F=F, C=C, L=L) + + # Then call the procedure on G[B - y] + procedure_P( + V_minus=X_prime, + V_plus=V_plus, + N=N, + H=H, + C=C, + F=F, + L=L, + excluded_colors=excluded_colors.union(A_cal), + ) + made_equitable = True + break + + if made_equitable: + break + else: + # No node in W_1 was found such that + # it had a solo-neighbor. + A_cal_0.add(W_1) + A_0.update(C[W_1]) + num_terminal_sets_found += 1 + + if num_terminal_sets_found == b: + # Otherwise, construct the maximal independent set and find + # a pair of z_1, z_2 as in Case II. + + # BFS to determine B_cal': the set of colors reachable from V+ + B_cal_prime = set() + T_cal_prime = {} + + reachable = [V_plus] + marked = set(reachable) + idx = 0 + while idx < len(reachable): + pop = reachable[idx] + idx += 1 + + B_cal_prime.add(pop) + + # No need to check for excluded_colors here because + # they only exclude colors from A_cal + next_layer = [ + k + for k in C + if H[(pop, k)] > 0 and k not in B_cal_prime and k not in marked + ] + + for dst in next_layer: + T_cal_prime[pop] = dst + + marked.update(next_layer) + reachable.extend(next_layer) + + # Construct the independent set of G[B'] + I_set = set() + I_covered = set() + W_covering = {} + + B_prime = [node for k in B_cal_prime for node in C[k]] + + # Add the nodes in V_plus to I first. + for z in C[V_plus] + B_prime: + if z in I_covered or F[z] not in B_cal_prime: + continue + + I_set.add(z) + I_covered.add(z) + I_covered.update(list(L[z])) + + for w in L[z]: + if F[w] in A_cal_0 and N[(z, F[w])] == 1: + if w not in W_covering: + W_covering[w] = z + else: + # Found z1, z2 which have the same solo + # neighbor in some W + z_1 = W_covering[w] + # z_2 = z + + Z = F[z_1] + W = F[w] + + # shift nodes along W, V- + move_witnesses( + W, V_minus, N=N, H=H, F=F, C=C, T_cal=T_cal, L=L + ) + + # shift nodes along V+ to Z + move_witnesses( + V_plus, + Z, + N=N, + H=H, + F=F, + C=C, + T_cal=T_cal_prime, + L=L, + ) + + # change color of z_1 to W + change_color(z_1, Z, W, N=N, H=H, F=F, C=C, L=L) + + # change color of w to some color in B_cal + W_plus = next( + k for k in C if N[(w, k)] == 0 and k not in A_cal + ) + change_color(w, W, W_plus, N=N, H=H, F=F, C=C, L=L) + + # recurse with G[B \cup W*] + excluded_colors.update( + [k for k in C if k != W and k not in B_cal_prime] + ) + procedure_P( + V_minus=W, + V_plus=W_plus, + N=N, + H=H, + C=C, + F=F, + L=L, + excluded_colors=excluded_colors, + ) + + made_equitable = True + break + + if made_equitable: + break + else: + assert False, ( + "Must find a w which is the solo neighbor " + "of two vertices in B_cal_prime." + ) + + if made_equitable: + break + + +@nx._dispatchable +def equitable_color(G, num_colors): + """Provides an equitable coloring for nodes of `G`. + + Attempts to color a graph using `num_colors` colors, where no neighbors of + a node can have same color as the node itself and the number of nodes with + each color differ by at most 1. `num_colors` must be greater than the + maximum degree of `G`. The algorithm is described in [1]_ and has + complexity O(num_colors * n**2). + + Parameters + ---------- + G : networkX graph + The nodes of this graph will be colored. + + num_colors : number of colors to use + This number must be at least one more than the maximum degree of nodes + in the graph. + + Returns + ------- + A dictionary with keys representing nodes and values representing + corresponding coloring. + + Examples + -------- + >>> G = nx.cycle_graph(4) + >>> nx.coloring.equitable_color(G, num_colors=3) # doctest: +SKIP + {0: 2, 1: 1, 2: 2, 3: 0} + + Raises + ------ + NetworkXAlgorithmError + If `num_colors` is not at least the maximum degree of the graph `G` + + References + ---------- + .. [1] Kierstead, H. A., Kostochka, A. V., Mydlarz, M., & Szemerédi, E. + (2010). A fast algorithm for equitable coloring. Combinatorica, 30(2), + 217-224. + """ + + # Map nodes to integers for simplicity later. + nodes_to_int = {} + int_to_nodes = {} + + for idx, node in enumerate(G.nodes): + nodes_to_int[node] = idx + int_to_nodes[idx] = node + + G = nx.relabel_nodes(G, nodes_to_int, copy=True) + + # Basic graph statistics and sanity check. + if len(G.nodes) > 0: + r_ = max(G.degree(node) for node in G.nodes) + else: + r_ = 0 + + if r_ >= num_colors: + raise nx.NetworkXAlgorithmError( + f"Graph has maximum degree {r_}, needs " + f"{r_ + 1} (> {num_colors}) colors for guaranteed coloring." + ) + + # Ensure that the number of nodes in G is a multiple of (r + 1) + pad_graph(G, num_colors) + + # Starting the algorithm. + # L = {node: list(G.neighbors(node)) for node in G.nodes} + L_ = {node: [] for node in G.nodes} + + # Arbitrary equitable allocation of colors to nodes. + F = {node: idx % num_colors for idx, node in enumerate(G.nodes)} + + C = make_C_from_F(F) + + # The neighborhood is empty initially. + N = make_N_from_L_C(L_, C) + + # Currently all nodes witness all edges. + H = make_H_from_C_N(C, N) + + # Start of algorithm. + edges_seen = set() + + for u in sorted(G.nodes): + for v in sorted(G.neighbors(u)): + # Do not double count edges if (v, u) has already been seen. + if (v, u) in edges_seen: + continue + + edges_seen.add((u, v)) + + L_[u].append(v) + L_[v].append(u) + + N[(u, F[v])] += 1 + N[(v, F[u])] += 1 + + if F[u] != F[v]: + # Were 'u' and 'v' witnesses for F[u] -> F[v] or F[v] -> F[u]? + if N[(u, F[v])] == 1: + H[F[u], F[v]] -= 1 # u cannot witness an edge between F[u], F[v] + + if N[(v, F[u])] == 1: + H[F[v], F[u]] -= 1 # v cannot witness an edge between F[v], F[u] + + if N[(u, F[u])] != 0: + # Find the first color where 'u' does not have any neighbors. + Y = next(k for k in C if N[(u, k)] == 0) + X = F[u] + change_color(u, X, Y, N=N, H=H, F=F, C=C, L=L_) + + # Procedure P + procedure_P(V_minus=X, V_plus=Y, N=N, H=H, F=F, C=C, L=L_) + + return {int_to_nodes[x]: F[x] for x in int_to_nodes} diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/__init__.py b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/__init__.py new file mode 100644 index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/__pycache__/__init__.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/__pycache__/__init__.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..a6952905a9a2daeffd3c29a56491c57174c532d0 Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/__pycache__/__init__.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/__pycache__/test_connected.cpython-310.pyc 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a/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_attracting.py b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_attracting.py new file mode 100644 index 0000000000000000000000000000000000000000..336c40ddc27162c1c2f5cc245f4fc840311506b5 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_attracting.py @@ -0,0 +1,70 @@ +import pytest + +import networkx as nx +from networkx import NetworkXNotImplemented + + +class TestAttractingComponents: + @classmethod + def setup_class(cls): + cls.G1 = nx.DiGraph() + cls.G1.add_edges_from( + [ + (5, 11), + (11, 2), + (11, 9), + (11, 10), + (7, 11), + (7, 8), + (8, 9), + (3, 8), + (3, 10), + ] + ) + cls.G2 = nx.DiGraph() + cls.G2.add_edges_from([(0, 1), (0, 2), (1, 1), (1, 2), (2, 1)]) + + cls.G3 = nx.DiGraph() + cls.G3.add_edges_from([(0, 1), (1, 2), (2, 1), (0, 3), (3, 4), (4, 3)]) + + cls.G4 = nx.DiGraph() + + def test_attracting_components(self): + ac = list(nx.attracting_components(self.G1)) + assert {2} in ac + assert {9} in ac + assert {10} in ac + + ac = list(nx.attracting_components(self.G2)) + ac = [tuple(sorted(x)) for x in ac] + assert ac == [(1, 2)] + + ac = list(nx.attracting_components(self.G3)) + ac = [tuple(sorted(x)) for x in ac] + assert (1, 2) in ac + assert (3, 4) in ac + assert len(ac) == 2 + + ac = list(nx.attracting_components(self.G4)) + assert ac == [] + + def test_number_attacting_components(self): + assert nx.number_attracting_components(self.G1) == 3 + assert nx.number_attracting_components(self.G2) == 1 + assert nx.number_attracting_components(self.G3) == 2 + assert nx.number_attracting_components(self.G4) == 0 + + def test_is_attracting_component(self): + assert not nx.is_attracting_component(self.G1) + assert not nx.is_attracting_component(self.G2) + assert not nx.is_attracting_component(self.G3) + g2 = self.G3.subgraph([1, 2]) + assert nx.is_attracting_component(g2) + assert not nx.is_attracting_component(self.G4) + + def test_connected_raise(self): + G = nx.Graph() + with pytest.raises(NetworkXNotImplemented): + next(nx.attracting_components(G)) + pytest.raises(NetworkXNotImplemented, nx.number_attracting_components, G) + pytest.raises(NetworkXNotImplemented, nx.is_attracting_component, G) diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_biconnected.py b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_biconnected.py new file mode 100644 index 0000000000000000000000000000000000000000..19d2d8831ced26a516d101e735b6701f39865c1b --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_biconnected.py @@ -0,0 +1,248 @@ +import pytest + +import networkx as nx +from networkx import NetworkXNotImplemented + + +def assert_components_edges_equal(x, y): + sx = {frozenset(frozenset(e) for e in c) for c in x} + sy = {frozenset(frozenset(e) for e in c) for c in y} + assert sx == sy + + +def assert_components_equal(x, y): + sx = {frozenset(c) for c in x} + sy = {frozenset(c) for c in y} + assert sx == sy + + +def test_barbell(): + G = nx.barbell_graph(8, 4) + nx.add_path(G, [7, 20, 21, 22]) + nx.add_cycle(G, [22, 23, 24, 25]) + pts = set(nx.articulation_points(G)) + assert pts == {7, 8, 9, 10, 11, 12, 20, 21, 22} + + answer = [ + {12, 13, 14, 15, 16, 17, 18, 19}, + {0, 1, 2, 3, 4, 5, 6, 7}, + {22, 23, 24, 25}, + {11, 12}, + {10, 11}, + {9, 10}, + {8, 9}, + {7, 8}, + {21, 22}, + {20, 21}, + {7, 20}, + ] + assert_components_equal(list(nx.biconnected_components(G)), answer) + + G.add_edge(2, 17) + pts = set(nx.articulation_points(G)) + assert pts == {7, 20, 21, 22} + + +def test_articulation_points_repetitions(): + G = nx.Graph() + G.add_edges_from([(0, 1), (1, 2), (1, 3)]) + assert list(nx.articulation_points(G)) == [1] + + +def test_articulation_points_cycle(): + G = nx.cycle_graph(3) + nx.add_cycle(G, [1, 3, 4]) + pts = set(nx.articulation_points(G)) + assert pts == {1} + + +def test_is_biconnected(): + G = nx.cycle_graph(3) + assert nx.is_biconnected(G) + nx.add_cycle(G, [1, 3, 4]) + assert not nx.is_biconnected(G) + + +def test_empty_is_biconnected(): + G = nx.empty_graph(5) + assert not nx.is_biconnected(G) + G.add_edge(0, 1) + assert not nx.is_biconnected(G) + + +def test_biconnected_components_cycle(): + G = nx.cycle_graph(3) + nx.add_cycle(G, [1, 3, 4]) + answer = [{0, 1, 2}, {1, 3, 4}] + assert_components_equal(list(nx.biconnected_components(G)), answer) + + +def test_biconnected_components1(): + # graph example from + # https://web.archive.org/web/20121229123447/http://www.ibluemojo.com/school/articul_algorithm.html + edges = [ + (0, 1), + (0, 5), + (0, 6), + (0, 14), + (1, 5), + (1, 6), + (1, 14), + (2, 4), + (2, 10), + (3, 4), + (3, 15), + (4, 6), + (4, 7), + (4, 10), + (5, 14), + (6, 14), + (7, 9), + (8, 9), + (8, 12), + (8, 13), + (10, 15), + (11, 12), + (11, 13), + (12, 13), + ] + G = nx.Graph(edges) + pts = set(nx.articulation_points(G)) + assert pts == {4, 6, 7, 8, 9} + comps = list(nx.biconnected_component_edges(G)) + answer = [ + [(3, 4), (15, 3), (10, 15), (10, 4), (2, 10), (4, 2)], + [(13, 12), (13, 8), (11, 13), (12, 11), (8, 12)], + [(9, 8)], + [(7, 9)], + [(4, 7)], + [(6, 4)], + [(14, 0), (5, 1), (5, 0), (14, 5), (14, 1), (6, 14), (6, 0), (1, 6), (0, 1)], + ] + assert_components_edges_equal(comps, answer) + + +def test_biconnected_components2(): + G = nx.Graph() + nx.add_cycle(G, "ABC") + nx.add_cycle(G, "CDE") + nx.add_cycle(G, "FIJHG") + nx.add_cycle(G, "GIJ") + G.add_edge("E", "G") + comps = list(nx.biconnected_component_edges(G)) + answer = [ + [ + tuple("GF"), + tuple("FI"), + tuple("IG"), + tuple("IJ"), + tuple("JG"), + tuple("JH"), + tuple("HG"), + ], + [tuple("EG")], + [tuple("CD"), tuple("DE"), tuple("CE")], + [tuple("AB"), tuple("BC"), tuple("AC")], + ] + assert_components_edges_equal(comps, answer) + + +def test_biconnected_davis(): + D = nx.davis_southern_women_graph() + bcc = list(nx.biconnected_components(D))[0] + assert set(D) == bcc # All nodes in a giant bicomponent + # So no articulation points + assert len(list(nx.articulation_points(D))) == 0 + + +def test_biconnected_karate(): + K = nx.karate_club_graph() + answer = [ + { + 0, + 1, + 2, + 3, + 7, + 8, + 9, + 12, + 13, + 14, + 15, + 17, + 18, + 19, + 20, + 21, + 22, + 23, + 24, + 25, + 26, + 27, + 28, + 29, + 30, + 31, + 32, + 33, + }, + {0, 4, 5, 6, 10, 16}, + {0, 11}, + ] + bcc = list(nx.biconnected_components(K)) + assert_components_equal(bcc, answer) + assert set(nx.articulation_points(K)) == {0} + + +def test_biconnected_eppstein(): + # tests from http://www.ics.uci.edu/~eppstein/PADS/Biconnectivity.py + G1 = nx.Graph( + { + 0: [1, 2, 5], + 1: [0, 5], + 2: [0, 3, 4], + 3: [2, 4, 5, 6], + 4: [2, 3, 5, 6], + 5: [0, 1, 3, 4], + 6: [3, 4], + } + ) + G2 = nx.Graph( + { + 0: [2, 5], + 1: [3, 8], + 2: [0, 3, 5], + 3: [1, 2, 6, 8], + 4: [7], + 5: [0, 2], + 6: [3, 8], + 7: [4], + 8: [1, 3, 6], + } + ) + assert nx.is_biconnected(G1) + assert not nx.is_biconnected(G2) + answer_G2 = [{1, 3, 6, 8}, {0, 2, 5}, {2, 3}, {4, 7}] + bcc = list(nx.biconnected_components(G2)) + assert_components_equal(bcc, answer_G2) + + +def test_null_graph(): + G = nx.Graph() + assert not nx.is_biconnected(G) + assert list(nx.biconnected_components(G)) == [] + assert list(nx.biconnected_component_edges(G)) == [] + assert list(nx.articulation_points(G)) == [] + + +def test_connected_raise(): + DG = nx.DiGraph() + with pytest.raises(NetworkXNotImplemented): + next(nx.biconnected_components(DG)) + with pytest.raises(NetworkXNotImplemented): + next(nx.biconnected_component_edges(DG)) + with pytest.raises(NetworkXNotImplemented): + next(nx.articulation_points(DG)) + pytest.raises(NetworkXNotImplemented, nx.is_biconnected, DG) diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_semiconnected.py b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_semiconnected.py new file mode 100644 index 0000000000000000000000000000000000000000..6376bbfb12a061e1724b0c74d2614e116149d8bf --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/algorithms/components/tests/test_semiconnected.py @@ -0,0 +1,55 @@ +from itertools import chain + +import pytest + +import networkx as nx + + +class TestIsSemiconnected: + def test_undirected(self): + pytest.raises(nx.NetworkXNotImplemented, nx.is_semiconnected, nx.Graph()) + pytest.raises(nx.NetworkXNotImplemented, nx.is_semiconnected, nx.MultiGraph()) + + def test_empty(self): + pytest.raises(nx.NetworkXPointlessConcept, nx.is_semiconnected, nx.DiGraph()) + pytest.raises( + nx.NetworkXPointlessConcept, nx.is_semiconnected, nx.MultiDiGraph() + ) + + def test_single_node_graph(self): + G = nx.DiGraph() + G.add_node(0) + assert nx.is_semiconnected(G) + + def test_path(self): + G = nx.path_graph(100, create_using=nx.DiGraph()) + assert nx.is_semiconnected(G) + G.add_edge(100, 99) + assert not nx.is_semiconnected(G) + + def test_cycle(self): + G = nx.cycle_graph(100, create_using=nx.DiGraph()) + assert nx.is_semiconnected(G) + G = nx.path_graph(100, create_using=nx.DiGraph()) + G.add_edge(0, 99) + assert nx.is_semiconnected(G) + + def test_tree(self): + G = nx.DiGraph() + G.add_edges_from( + chain.from_iterable([(i, 2 * i + 1), (i, 2 * i + 2)] for i in range(100)) + ) + assert not nx.is_semiconnected(G) + + def test_dumbbell(self): + G = nx.cycle_graph(100, create_using=nx.DiGraph()) + G.add_edges_from((i + 100, (i + 1) % 100 + 100) for i in range(100)) + assert not nx.is_semiconnected(G) # G is disconnected. + G.add_edge(100, 99) + assert nx.is_semiconnected(G) + + def test_alternating_path(self): + G = nx.DiGraph( + chain.from_iterable([(i, i - 1), (i, i + 1)] for i in range(0, 100, 2)) + ) + assert not nx.is_semiconnected(G) diff --git a/janus/lib/python3.10/site-packages/networkx/algorithms/components/weakly_connected.py b/janus/lib/python3.10/site-packages/networkx/algorithms/components/weakly_connected.py new file mode 100644 index 0000000000000000000000000000000000000000..ecfac50a75177a7a87e41430953276e29778d6e0 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/algorithms/components/weakly_connected.py @@ -0,0 +1,197 @@ +"""Weakly connected components.""" + +import networkx as nx +from networkx.utils.decorators import not_implemented_for + +__all__ = [ + "number_weakly_connected_components", + "weakly_connected_components", + "is_weakly_connected", +] + + +@not_implemented_for("undirected") +@nx._dispatchable +def weakly_connected_components(G): + """Generate weakly connected components of G. + + Parameters + ---------- + G : NetworkX graph + A directed graph + + Returns + ------- + comp : generator of sets + A generator of sets of nodes, one for each weakly connected + component of G. + + Raises + ------ + NetworkXNotImplemented + If G is undirected. + + Examples + -------- + Generate a sorted list of weakly connected components, largest first. + + >>> G = nx.path_graph(4, create_using=nx.DiGraph()) + >>> nx.add_path(G, [10, 11, 12]) + >>> [ + ... len(c) + ... for c in sorted(nx.weakly_connected_components(G), key=len, reverse=True) + ... ] + [4, 3] + + If you only want the largest component, it's more efficient to + use max instead of sort: + + >>> largest_cc = max(nx.weakly_connected_components(G), key=len) + + See Also + -------- + connected_components + strongly_connected_components + + Notes + ----- + For directed graphs only. + + """ + seen = set() + n = len(G) # must be outside the loop to avoid performance hit with graph views + for v in G: + if v not in seen: + c = set(_plain_bfs(G, n, v)) + seen.update(c) + yield c + + +@not_implemented_for("undirected") +@nx._dispatchable +def number_weakly_connected_components(G): + """Returns the number of weakly connected components in G. + + Parameters + ---------- + G : NetworkX graph + A directed graph. + + Returns + ------- + n : integer + Number of weakly connected components + + Raises + ------ + NetworkXNotImplemented + If G is undirected. + + Examples + -------- + >>> G = nx.DiGraph([(0, 1), (2, 1), (3, 4)]) + >>> nx.number_weakly_connected_components(G) + 2 + + See Also + -------- + weakly_connected_components + number_connected_components + number_strongly_connected_components + + Notes + ----- + For directed graphs only. + + """ + return sum(1 for wcc in weakly_connected_components(G)) + + +@not_implemented_for("undirected") +@nx._dispatchable +def is_weakly_connected(G): + """Test directed graph for weak connectivity. + + A directed graph is weakly connected if and only if the graph + is connected when the direction of the edge between nodes is ignored. + + Note that if a graph is strongly connected (i.e. the graph is connected + even when we account for directionality), it is by definition weakly + connected as well. + + Parameters + ---------- + G : NetworkX Graph + A directed graph. + + Returns + ------- + connected : bool + True if the graph is weakly connected, False otherwise. + + Raises + ------ + NetworkXNotImplemented + If G is undirected. + + Examples + -------- + >>> G = nx.DiGraph([(0, 1), (2, 1)]) + >>> G.add_node(3) + >>> nx.is_weakly_connected(G) # node 3 is not connected to the graph + False + >>> G.add_edge(2, 3) + >>> nx.is_weakly_connected(G) + True + + See Also + -------- + is_strongly_connected + is_semiconnected + is_connected + is_biconnected + weakly_connected_components + + Notes + ----- + For directed graphs only. + + """ + if len(G) == 0: + raise nx.NetworkXPointlessConcept( + """Connectivity is undefined for the null graph.""" + ) + + return len(next(weakly_connected_components(G))) == len(G) + + +def _plain_bfs(G, n, source): + """A fast BFS node generator + + The direction of the edge between nodes is ignored. + + For directed graphs only. + + """ + Gsucc = G._succ + Gpred = G._pred + seen = {source} + nextlevel = [source] + + yield source + while nextlevel: + thislevel = nextlevel + nextlevel = [] + for v in thislevel: + for w in Gsucc[v]: + if w not in seen: + seen.add(w) + nextlevel.append(w) + yield w + for w in Gpred[v]: + if w not in seen: + seen.add(w) + nextlevel.append(w) + yield w + if len(seen) == n: + return diff --git a/janus/lib/python3.10/site-packages/networkx/drawing/tests/baseline/test_house_with_colors.png b/janus/lib/python3.10/site-packages/networkx/drawing/tests/baseline/test_house_with_colors.png new file mode 100644 index 0000000000000000000000000000000000000000..6c9e5bdee713b998b23ceb6782595b29c2870a0d --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/drawing/tests/baseline/test_house_with_colors.png @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1508bda48445c23ab882f801f1c0dd0472f97ae414245c3ab1094005fda4455a +size 21918 diff --git 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0000000000000000000000000000000000000000..c5dd8d2d8fee8cf7b49525fb05bbda14ab75305e --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/atlas.py @@ -0,0 +1,180 @@ +""" +Generators for the small graph atlas. +""" + +import gzip +import importlib.resources +import os +import os.path +from itertools import islice + +import networkx as nx + +__all__ = ["graph_atlas", "graph_atlas_g"] + +#: The total number of graphs in the atlas. +#: +#: The graphs are labeled starting from 0 and extending to (but not +#: including) this number. +NUM_GRAPHS = 1253 + +#: The path to the data file containing the graph edge lists. +#: +#: This is the absolute path of the gzipped text file containing the +#: edge list for each graph in the atlas. The file contains one entry +#: per graph in the atlas, in sequential order, starting from graph +#: number 0 and extending through graph number 1252 (see +#: :data:`NUM_GRAPHS`). Each entry looks like +#: +#: .. sourcecode:: text +#: +#: GRAPH 6 +#: NODES 3 +#: 0 1 +#: 0 2 +#: +#: where the first two lines are the graph's index in the atlas and the +#: number of nodes in the graph, and the remaining lines are the edge +#: list. +#: +#: This file was generated from a Python list of graphs via code like +#: the following:: +#: +#: import gzip +#: from networkx.generators.atlas import graph_atlas_g +#: from networkx.readwrite.edgelist import write_edgelist +#: +#: with gzip.open('atlas.dat.gz', 'wb') as f: +#: for i, G in enumerate(graph_atlas_g()): +#: f.write(bytes(f'GRAPH {i}\n', encoding='utf-8')) +#: f.write(bytes(f'NODES {len(G)}\n', encoding='utf-8')) +#: write_edgelist(G, f, data=False) +#: + +# Path to the atlas file +ATLAS_FILE = importlib.resources.files("networkx.generators") / "atlas.dat.gz" + + +def _generate_graphs(): + """Sequentially read the file containing the edge list data for the + graphs in the atlas and generate the graphs one at a time. + + This function reads the file given in :data:`.ATLAS_FILE`. + + """ + with gzip.open(ATLAS_FILE, "rb") as f: + line = f.readline() + while line and line.startswith(b"GRAPH"): + # The first two lines of each entry tell us the index of the + # graph in the list and the number of nodes in the graph. + # They look like this: + # + # GRAPH 3 + # NODES 2 + # + graph_index = int(line[6:].rstrip()) + line = f.readline() + num_nodes = int(line[6:].rstrip()) + # The remaining lines contain the edge list, until the next + # GRAPH line (or until the end of the file). + edgelist = [] + line = f.readline() + while line and not line.startswith(b"GRAPH"): + edgelist.append(line.rstrip()) + line = f.readline() + G = nx.Graph() + G.name = f"G{graph_index}" + G.add_nodes_from(range(num_nodes)) + G.add_edges_from(tuple(map(int, e.split())) for e in edgelist) + yield G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def graph_atlas(i): + """Returns graph number `i` from the Graph Atlas. + + For more information, see :func:`.graph_atlas_g`. + + Parameters + ---------- + i : int + The index of the graph from the atlas to get. The graph at index + 0 is assumed to be the null graph. + + Returns + ------- + list + A list of :class:`~networkx.Graph` objects, the one at index *i* + corresponding to the graph *i* in the Graph Atlas. + + See also + -------- + graph_atlas_g + + Notes + ----- + The time required by this function increases linearly with the + argument `i`, since it reads a large file sequentially in order to + generate the graph [1]_. + + References + ---------- + .. [1] Ronald C. Read and Robin J. Wilson, *An Atlas of Graphs*. + Oxford University Press, 1998. + + """ + if not (0 <= i < NUM_GRAPHS): + raise ValueError(f"index must be between 0 and {NUM_GRAPHS}") + return next(islice(_generate_graphs(), i, None)) + + +@nx._dispatchable(graphs=None, returns_graph=True) +def graph_atlas_g(): + """Returns the list of all graphs with up to seven nodes named in the + Graph Atlas. + + The graphs are listed in increasing order by + + 1. number of nodes, + 2. number of edges, + 3. degree sequence (for example 111223 < 112222), + 4. number of automorphisms, + + in that order, with three exceptions as described in the *Notes* + section below. This causes the list to correspond with the index of + the graphs in the Graph Atlas [atlas]_, with the first graph, + ``G[0]``, being the null graph. + + Returns + ------- + list + A list of :class:`~networkx.Graph` objects, the one at index *i* + corresponding to the graph *i* in the Graph Atlas. + + See also + -------- + graph_atlas + + Notes + ----- + This function may be expensive in both time and space, since it + reads a large file sequentially in order to populate the list. + + Although the NetworkX atlas functions match the order of graphs + given in the "Atlas of Graphs" book, there are (at least) three + errors in the ordering described in the book. The following three + pairs of nodes violate the lexicographically nondecreasing sorted + degree sequence rule: + + - graphs 55 and 56 with degree sequences 001111 and 000112, + - graphs 1007 and 1008 with degree sequences 3333444 and 3333336, + - graphs 1012 and 1213 with degree sequences 1244555 and 1244456. + + References + ---------- + .. [atlas] Ronald C. Read and Robin J. Wilson, + *An Atlas of Graphs*. + Oxford University Press, 1998. + + """ + return list(_generate_graphs()) diff --git a/janus/lib/python3.10/site-packages/networkx/generators/cographs.py b/janus/lib/python3.10/site-packages/networkx/generators/cographs.py new file mode 100644 index 0000000000000000000000000000000000000000..6635b32f691696c1b6f309ad0da81c3cbc43bed9 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/cographs.py @@ -0,0 +1,68 @@ +r"""Generators for cographs + +A cograph is a graph containing no path on four vertices. +Cographs or $P_4$-free graphs can be obtained from a single vertex +by disjoint union and complementation operations. + +References +---------- +.. [0] D.G. Corneil, H. Lerchs, L.Stewart Burlingham, + "Complement reducible graphs", + Discrete Applied Mathematics, Volume 3, Issue 3, 1981, Pages 163-174, + ISSN 0166-218X. +""" + +import networkx as nx +from networkx.utils import py_random_state + +__all__ = ["random_cograph"] + + +@py_random_state(1) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_cograph(n, seed=None): + r"""Returns a random cograph with $2 ^ n$ nodes. + + A cograph is a graph containing no path on four vertices. + Cographs or $P_4$-free graphs can be obtained from a single vertex + by disjoint union and complementation operations. + + This generator starts off from a single vertex and performs disjoint + union and full join operations on itself. + The decision on which operation will take place is random. + + Parameters + ---------- + n : int + The order of the cograph. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + G : A random graph containing no path on four vertices. + + See Also + -------- + full_join + union + + References + ---------- + .. [1] D.G. Corneil, H. Lerchs, L.Stewart Burlingham, + "Complement reducible graphs", + Discrete Applied Mathematics, Volume 3, Issue 3, 1981, Pages 163-174, + ISSN 0166-218X. + """ + R = nx.empty_graph(1) + + for i in range(n): + RR = nx.relabel_nodes(R.copy(), lambda x: x + len(R)) + + if seed.randint(0, 1) == 0: + R = nx.full_join(R, RR) + else: + R = nx.disjoint_union(R, RR) + + return R diff --git a/janus/lib/python3.10/site-packages/networkx/generators/duplication.py b/janus/lib/python3.10/site-packages/networkx/generators/duplication.py new file mode 100644 index 0000000000000000000000000000000000000000..3c3ade63f58237eeb927ff631b25f025d7d83fc1 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/duplication.py @@ -0,0 +1,174 @@ +"""Functions for generating graphs based on the "duplication" method. + +These graph generators start with a small initial graph then duplicate +nodes and (partially) duplicate their edges. These functions are +generally inspired by biological networks. + +""" + +import networkx as nx +from networkx.exception import NetworkXError +from networkx.utils import py_random_state +from networkx.utils.misc import check_create_using + +__all__ = ["partial_duplication_graph", "duplication_divergence_graph"] + + +@py_random_state(4) +@nx._dispatchable(graphs=None, returns_graph=True) +def partial_duplication_graph(N, n, p, q, seed=None, *, create_using=None): + """Returns a random graph using the partial duplication model. + + Parameters + ---------- + N : int + The total number of nodes in the final graph. + + n : int + The number of nodes in the initial clique. + + p : float + The probability of joining each neighbor of a node to the + duplicate node. Must be a number in the between zero and one, + inclusive. + + q : float + The probability of joining the source node to the duplicate + node. Must be a number in the between zero and one, inclusive. + + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Notes + ----- + A graph of nodes is grown by creating a fully connected graph + of size `n`. The following procedure is then repeated until + a total of `N` nodes have been reached. + + 1. A random node, *u*, is picked and a new node, *v*, is created. + 2. For each neighbor of *u* an edge from the neighbor to *v* is created + with probability `p`. + 3. An edge from *u* to *v* is created with probability `q`. + + This algorithm appears in [1]. + + This implementation allows the possibility of generating + disconnected graphs. + + References + ---------- + .. [1] Knudsen Michael, and Carsten Wiuf. "A Markov chain approach to + randomly grown graphs." Journal of Applied Mathematics 2008. + + + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if p < 0 or p > 1 or q < 0 or q > 1: + msg = "partial duplication graph must have 0 <= p, q <= 1." + raise NetworkXError(msg) + if n > N: + raise NetworkXError("partial duplication graph must have n <= N.") + + G = nx.complete_graph(n, create_using) + for new_node in range(n, N): + # Pick a random vertex, u, already in the graph. + src_node = seed.randint(0, new_node - 1) + + # Add a new vertex, v, to the graph. + G.add_node(new_node) + + # For each neighbor of u... + for nbr_node in list(nx.all_neighbors(G, src_node)): + # Add the neighbor to v with probability p. + if seed.random() < p: + G.add_edge(new_node, nbr_node) + + # Join v and u with probability q. + if seed.random() < q: + G.add_edge(new_node, src_node) + return G + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def duplication_divergence_graph(n, p, seed=None, *, create_using=None): + """Returns an undirected graph using the duplication-divergence model. + + A graph of `n` nodes is created by duplicating the initial nodes + and retaining edges incident to the original nodes with a retention + probability `p`. + + Parameters + ---------- + n : int + The desired number of nodes in the graph. + p : float + The probability for retaining the edge of the replicated node. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Returns + ------- + G : Graph + + Raises + ------ + NetworkXError + If `p` is not a valid probability. + If `n` is less than 2. + + Notes + ----- + This algorithm appears in [1]. + + This implementation disallows the possibility of generating + disconnected graphs. + + References + ---------- + .. [1] I. Ispolatov, P. L. Krapivsky, A. Yuryev, + "Duplication-divergence model of protein interaction network", + Phys. Rev. E, 71, 061911, 2005. + + """ + if p > 1 or p < 0: + msg = f"NetworkXError p={p} is not in [0,1]." + raise nx.NetworkXError(msg) + if n < 2: + msg = "n must be greater than or equal to 2" + raise nx.NetworkXError(msg) + + create_using = check_create_using(create_using, directed=False, multigraph=False) + G = nx.empty_graph(create_using=create_using) + + # Initialize the graph with two connected nodes. + G.add_edge(0, 1) + i = 2 + while i < n: + # Choose a random node from current graph to duplicate. + random_node = seed.choice(list(G)) + # Make the replica. + G.add_node(i) + # flag indicates whether at least one edge is connected on the replica. + flag = False + for nbr in G.neighbors(random_node): + if seed.random() < p: + # Link retention step. + G.add_edge(i, nbr) + flag = True + if not flag: + # Delete replica if no edges retained. + G.remove_node(i) + else: + # Successful duplication. + i += 1 + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/ego.py b/janus/lib/python3.10/site-packages/networkx/generators/ego.py new file mode 100644 index 0000000000000000000000000000000000000000..1c705430d8b52cf47d1e1b681397c929221e58a0 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/ego.py @@ -0,0 +1,66 @@ +""" +Ego graph. +""" + +__all__ = ["ego_graph"] + +import networkx as nx + + +@nx._dispatchable(preserve_all_attrs=True, returns_graph=True) +def ego_graph(G, n, radius=1, center=True, undirected=False, distance=None): + """Returns induced subgraph of neighbors centered at node n within + a given radius. + + Parameters + ---------- + G : graph + A NetworkX Graph or DiGraph + + n : node + A single node + + radius : number, optional + Include all neighbors of distance<=radius from n. + + center : bool, optional + If False, do not include center node in graph + + undirected : bool, optional + If True use both in- and out-neighbors of directed graphs. + + distance : key, optional + Use specified edge data key as distance. For example, setting + distance='weight' will use the edge weight to measure the + distance from the node n. + + Notes + ----- + For directed graphs D this produces the "out" neighborhood + or successors. If you want the neighborhood of predecessors + first reverse the graph with D.reverse(). If you want both + directions use the keyword argument undirected=True. + + Node, edge, and graph attributes are copied to the returned subgraph. + """ + if undirected: + if distance is not None: + sp, _ = nx.single_source_dijkstra( + G.to_undirected(), n, cutoff=radius, weight=distance + ) + else: + sp = dict( + nx.single_source_shortest_path_length( + G.to_undirected(), n, cutoff=radius + ) + ) + else: + if distance is not None: + sp, _ = nx.single_source_dijkstra(G, n, cutoff=radius, weight=distance) + else: + sp = dict(nx.single_source_shortest_path_length(G, n, cutoff=radius)) + + H = G.subgraph(sp).copy() + if not center: + H.remove_node(n) + return H diff --git a/janus/lib/python3.10/site-packages/networkx/generators/expanders.py b/janus/lib/python3.10/site-packages/networkx/generators/expanders.py new file mode 100644 index 0000000000000000000000000000000000000000..befdb0e4b0f3579a272491d8ea6b970716c57f6e --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/expanders.py @@ -0,0 +1,474 @@ +"""Provides explicit constructions of expander graphs.""" + +import itertools + +import networkx as nx + +__all__ = [ + "margulis_gabber_galil_graph", + "chordal_cycle_graph", + "paley_graph", + "maybe_regular_expander", + "is_regular_expander", + "random_regular_expander_graph", +] + + +# Other discrete torus expanders can be constructed by using the following edge +# sets. For more information, see Chapter 4, "Expander Graphs", in +# "Pseudorandomness", by Salil Vadhan. +# +# For a directed expander, add edges from (x, y) to: +# +# (x, y), +# ((x + 1) % n, y), +# (x, (y + 1) % n), +# (x, (x + y) % n), +# (-y % n, x) +# +# For an undirected expander, add the reverse edges. +# +# Also appearing in the paper of Gabber and Galil: +# +# (x, y), +# (x, (x + y) % n), +# (x, (x + y + 1) % n), +# ((x + y) % n, y), +# ((x + y + 1) % n, y) +# +# and: +# +# (x, y), +# ((x + 2*y) % n, y), +# ((x + (2*y + 1)) % n, y), +# ((x + (2*y + 2)) % n, y), +# (x, (y + 2*x) % n), +# (x, (y + (2*x + 1)) % n), +# (x, (y + (2*x + 2)) % n), +# +@nx._dispatchable(graphs=None, returns_graph=True) +def margulis_gabber_galil_graph(n, create_using=None): + r"""Returns the Margulis-Gabber-Galil undirected MultiGraph on `n^2` nodes. + + The undirected MultiGraph is regular with degree `8`. Nodes are integer + pairs. The second-largest eigenvalue of the adjacency matrix of the graph + is at most `5 \sqrt{2}`, regardless of `n`. + + Parameters + ---------- + n : int + Determines the number of nodes in the graph: `n^2`. + create_using : NetworkX graph constructor, optional (default MultiGraph) + Graph type to create. If graph instance, then cleared before populated. + + Returns + ------- + G : graph + The constructed undirected multigraph. + + Raises + ------ + NetworkXError + If the graph is directed or not a multigraph. + + """ + G = nx.empty_graph(0, create_using, default=nx.MultiGraph) + if G.is_directed() or not G.is_multigraph(): + msg = "`create_using` must be an undirected multigraph." + raise nx.NetworkXError(msg) + + for x, y in itertools.product(range(n), repeat=2): + for u, v in ( + ((x + 2 * y) % n, y), + ((x + (2 * y + 1)) % n, y), + (x, (y + 2 * x) % n), + (x, (y + (2 * x + 1)) % n), + ): + G.add_edge((x, y), (u, v)) + G.graph["name"] = f"margulis_gabber_galil_graph({n})" + return G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def chordal_cycle_graph(p, create_using=None): + """Returns the chordal cycle graph on `p` nodes. + + The returned graph is a cycle graph on `p` nodes with chords joining each + vertex `x` to its inverse modulo `p`. This graph is a (mildly explicit) + 3-regular expander [1]_. + + `p` *must* be a prime number. + + Parameters + ---------- + p : a prime number + + The number of vertices in the graph. This also indicates where the + chordal edges in the cycle will be created. + + create_using : NetworkX graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + + Returns + ------- + G : graph + The constructed undirected multigraph. + + Raises + ------ + NetworkXError + + If `create_using` indicates directed or not a multigraph. + + References + ---------- + + .. [1] Theorem 4.4.2 in A. Lubotzky. "Discrete groups, expanding graphs and + invariant measures", volume 125 of Progress in Mathematics. + Birkhäuser Verlag, Basel, 1994. + + """ + G = nx.empty_graph(0, create_using, default=nx.MultiGraph) + if G.is_directed() or not G.is_multigraph(): + msg = "`create_using` must be an undirected multigraph." + raise nx.NetworkXError(msg) + + for x in range(p): + left = (x - 1) % p + right = (x + 1) % p + # Here we apply Fermat's Little Theorem to compute the multiplicative + # inverse of x in Z/pZ. By Fermat's Little Theorem, + # + # x^p = x (mod p) + # + # Therefore, + # + # x * x^(p - 2) = 1 (mod p) + # + # The number 0 is a special case: we just let its inverse be itself. + chord = pow(x, p - 2, p) if x > 0 else 0 + for y in (left, right, chord): + G.add_edge(x, y) + G.graph["name"] = f"chordal_cycle_graph({p})" + return G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def paley_graph(p, create_using=None): + r"""Returns the Paley $\frac{(p-1)}{2}$ -regular graph on $p$ nodes. + + The returned graph is a graph on $\mathbb{Z}/p\mathbb{Z}$ with edges between $x$ and $y$ + if and only if $x-y$ is a nonzero square in $\mathbb{Z}/p\mathbb{Z}$. + + If $p \equiv 1 \pmod 4$, $-1$ is a square in $\mathbb{Z}/p\mathbb{Z}$ and therefore $x-y$ is a square if and + only if $y-x$ is also a square, i.e the edges in the Paley graph are symmetric. + + If $p \equiv 3 \pmod 4$, $-1$ is not a square in $\mathbb{Z}/p\mathbb{Z}$ and therefore either $x-y$ or $y-x$ + is a square in $\mathbb{Z}/p\mathbb{Z}$ but not both. + + Note that a more general definition of Paley graphs extends this construction + to graphs over $q=p^n$ vertices, by using the finite field $F_q$ instead of $\mathbb{Z}/p\mathbb{Z}$. + This construction requires to compute squares in general finite fields and is + not what is implemented here (i.e `paley_graph(25)` does not return the true + Paley graph associated with $5^2$). + + Parameters + ---------- + p : int, an odd prime number. + + create_using : NetworkX graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + + Returns + ------- + G : graph + The constructed directed graph. + + Raises + ------ + NetworkXError + If the graph is a multigraph. + + References + ---------- + Chapter 13 in B. Bollobas, Random Graphs. Second edition. + Cambridge Studies in Advanced Mathematics, 73. + Cambridge University Press, Cambridge (2001). + """ + G = nx.empty_graph(0, create_using, default=nx.DiGraph) + if G.is_multigraph(): + msg = "`create_using` cannot be a multigraph." + raise nx.NetworkXError(msg) + + # Compute the squares in Z/pZ. + # Make it a set to uniquify (there are exactly (p-1)/2 squares in Z/pZ + # when is prime). + square_set = {(x**2) % p for x in range(1, p) if (x**2) % p != 0} + + for x in range(p): + for x2 in square_set: + G.add_edge(x, (x + x2) % p) + G.graph["name"] = f"paley({p})" + return G + + +@nx.utils.decorators.np_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def maybe_regular_expander(n, d, *, create_using=None, max_tries=100, seed=None): + r"""Utility for creating a random regular expander. + + Returns a random $d$-regular graph on $n$ nodes which is an expander + graph with very good probability. + + Parameters + ---------- + n : int + The number of nodes. + d : int + The degree of each node. + create_using : Graph Instance or Constructor + Indicator of type of graph to return. + If a Graph-type instance, then clear and use it. + If a constructor, call it to create an empty graph. + Use the Graph constructor by default. + max_tries : int. (default: 100) + The number of allowed loops when generating each independent cycle + seed : (default: None) + Seed used to set random number generation state. See :ref`Randomness`. + + Notes + ----- + The nodes are numbered from $0$ to $n - 1$. + + The graph is generated by taking $d / 2$ random independent cycles. + + Joel Friedman proved that in this model the resulting + graph is an expander with probability + $1 - O(n^{-\tau})$ where $\tau = \lceil (\sqrt{d - 1}) / 2 \rceil - 1$. [1]_ + + Examples + -------- + >>> G = nx.maybe_regular_expander(n=200, d=6, seed=8020) + + Returns + ------- + G : graph + The constructed undirected graph. + + Raises + ------ + NetworkXError + If $d % 2 != 0$ as the degree must be even. + If $n - 1$ is less than $ 2d $ as the graph is complete at most. + If max_tries is reached + + See Also + -------- + is_regular_expander + random_regular_expander_graph + + References + ---------- + .. [1] Joel Friedman, + A Proof of Alon’s Second Eigenvalue Conjecture and Related Problems, 2004 + https://arxiv.org/abs/cs/0405020 + + """ + + import numpy as np + + if n < 1: + raise nx.NetworkXError("n must be a positive integer") + + if not (d >= 2): + raise nx.NetworkXError("d must be greater than or equal to 2") + + if not (d % 2 == 0): + raise nx.NetworkXError("d must be even") + + if not (n - 1 >= d): + raise nx.NetworkXError( + f"Need n-1>= d to have room for {d//2} independent cycles with {n} nodes" + ) + + G = nx.empty_graph(n, create_using) + + if n < 2: + return G + + cycles = [] + edges = set() + + # Create d / 2 cycles + for i in range(d // 2): + iterations = max_tries + # Make sure the cycles are independent to have a regular graph + while len(edges) != (i + 1) * n: + iterations -= 1 + # Faster than random.permutation(n) since there are only + # (n-1)! distinct cycles against n! permutations of size n + cycle = seed.permutation(n - 1).tolist() + cycle.append(n - 1) + + new_edges = { + (u, v) + for u, v in nx.utils.pairwise(cycle, cyclic=True) + if (u, v) not in edges and (v, u) not in edges + } + # If the new cycle has no edges in common with previous cycles + # then add it to the list otherwise try again + if len(new_edges) == n: + cycles.append(cycle) + edges.update(new_edges) + + if iterations == 0: + raise nx.NetworkXError("Too many iterations in maybe_regular_expander") + + G.add_edges_from(edges) + + return G + + +@nx.utils.not_implemented_for("directed") +@nx.utils.not_implemented_for("multigraph") +@nx._dispatchable(preserve_edge_attrs={"G": {"weight": 1}}) +def is_regular_expander(G, *, epsilon=0): + r"""Determines whether the graph G is a regular expander. [1]_ + + An expander graph is a sparse graph with strong connectivity properties. + + More precisely, this helper checks whether the graph is a + regular $(n, d, \lambda)$-expander with $\lambda$ close to + the Alon-Boppana bound and given by + $\lambda = 2 \sqrt{d - 1} + \epsilon$. [2]_ + + In the case where $\epsilon = 0$ then if the graph successfully passes the test + it is a Ramanujan graph. [3]_ + + A Ramanujan graph has spectral gap almost as large as possible, which makes them + excellent expanders. + + Parameters + ---------- + G : NetworkX graph + epsilon : int, float, default=0 + + Returns + ------- + bool + Whether the given graph is a regular $(n, d, \lambda)$-expander + where $\lambda = 2 \sqrt{d - 1} + \epsilon$. + + Examples + -------- + >>> G = nx.random_regular_expander_graph(20, 4) + >>> nx.is_regular_expander(G) + True + + See Also + -------- + maybe_regular_expander + random_regular_expander_graph + + References + ---------- + .. [1] Expander graph, https://en.wikipedia.org/wiki/Expander_graph + .. [2] Alon-Boppana bound, https://en.wikipedia.org/wiki/Alon%E2%80%93Boppana_bound + .. [3] Ramanujan graphs, https://en.wikipedia.org/wiki/Ramanujan_graph + + """ + + import numpy as np + from scipy.sparse.linalg import eigsh + + if epsilon < 0: + raise nx.NetworkXError("epsilon must be non negative") + + if not nx.is_regular(G): + return False + + _, d = nx.utils.arbitrary_element(G.degree) + + A = nx.adjacency_matrix(G, dtype=float) + lams = eigsh(A, which="LM", k=2, return_eigenvectors=False) + + # lambda2 is the second biggest eigenvalue + lambda2 = min(lams) + + # Use bool() to convert numpy scalar to Python Boolean + return bool(abs(lambda2) < 2 ** np.sqrt(d - 1) + epsilon) + + +@nx.utils.decorators.np_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_regular_expander_graph( + n, d, *, epsilon=0, create_using=None, max_tries=100, seed=None +): + r"""Returns a random regular expander graph on $n$ nodes with degree $d$. + + An expander graph is a sparse graph with strong connectivity properties. [1]_ + + More precisely the returned graph is a $(n, d, \lambda)$-expander with + $\lambda = 2 \sqrt{d - 1} + \epsilon$, close to the Alon-Boppana bound. [2]_ + + In the case where $\epsilon = 0$ it returns a Ramanujan graph. + A Ramanujan graph has spectral gap almost as large as possible, + which makes them excellent expanders. [3]_ + + Parameters + ---------- + n : int + The number of nodes. + d : int + The degree of each node. + epsilon : int, float, default=0 + max_tries : int, (default: 100) + The number of allowed loops, also used in the maybe_regular_expander utility + seed : (default: None) + Seed used to set random number generation state. See :ref`Randomness`. + + Raises + ------ + NetworkXError + If max_tries is reached + + Examples + -------- + >>> G = nx.random_regular_expander_graph(20, 4) + >>> nx.is_regular_expander(G) + True + + Notes + ----- + This loops over `maybe_regular_expander` and can be slow when + $n$ is too big or $\epsilon$ too small. + + See Also + -------- + maybe_regular_expander + is_regular_expander + + References + ---------- + .. [1] Expander graph, https://en.wikipedia.org/wiki/Expander_graph + .. [2] Alon-Boppana bound, https://en.wikipedia.org/wiki/Alon%E2%80%93Boppana_bound + .. [3] Ramanujan graphs, https://en.wikipedia.org/wiki/Ramanujan_graph + + """ + G = maybe_regular_expander( + n, d, create_using=create_using, max_tries=max_tries, seed=seed + ) + iterations = max_tries + + while not is_regular_expander(G, epsilon=epsilon): + iterations -= 1 + G = maybe_regular_expander( + n=n, d=d, create_using=create_using, max_tries=max_tries, seed=seed + ) + + if iterations == 0: + raise nx.NetworkXError( + "Too many iterations in random_regular_expander_graph" + ) + + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/geometric.py b/janus/lib/python3.10/site-packages/networkx/generators/geometric.py new file mode 100644 index 0000000000000000000000000000000000000000..7f19281b81fd9d109565c005174b27513ce6ae02 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/geometric.py @@ -0,0 +1,1048 @@ +"""Generators for geometric graphs.""" + +import math +from bisect import bisect_left +from itertools import accumulate, combinations, product + +import networkx as nx +from networkx.utils import py_random_state + +__all__ = [ + "geometric_edges", + "geographical_threshold_graph", + "navigable_small_world_graph", + "random_geometric_graph", + "soft_random_geometric_graph", + "thresholded_random_geometric_graph", + "waxman_graph", + "geometric_soft_configuration_graph", +] + + +@nx._dispatchable(node_attrs="pos_name") +def geometric_edges(G, radius, p=2, *, pos_name="pos"): + """Returns edge list of node pairs within `radius` of each other. + + Parameters + ---------- + G : networkx graph + The graph from which to generate the edge list. The nodes in `G` should + have an attribute ``pos`` corresponding to the node position, which is + used to compute the distance to other nodes. + radius : scalar + The distance threshold. Edges are included in the edge list if the + distance between the two nodes is less than `radius`. + pos_name : string, default="pos" + The name of the node attribute which represents the position of each + node in 2D coordinates. Every node in the Graph must have this attribute. + p : scalar, default=2 + The `Minkowski distance metric + `_ used to compute + distances. The default value is 2, i.e. Euclidean distance. + + Returns + ------- + edges : list + List of edges whose distances are less than `radius` + + Notes + ----- + Radius uses Minkowski distance metric `p`. + If scipy is available, `scipy.spatial.cKDTree` is used to speed computation. + + Examples + -------- + Create a graph with nodes that have a "pos" attribute representing 2D + coordinates. + + >>> G = nx.Graph() + >>> G.add_nodes_from( + ... [ + ... (0, {"pos": (0, 0)}), + ... (1, {"pos": (3, 0)}), + ... (2, {"pos": (8, 0)}), + ... ] + ... ) + >>> nx.geometric_edges(G, radius=1) + [] + >>> nx.geometric_edges(G, radius=4) + [(0, 1)] + >>> nx.geometric_edges(G, radius=6) + [(0, 1), (1, 2)] + >>> nx.geometric_edges(G, radius=9) + [(0, 1), (0, 2), (1, 2)] + """ + # Input validation - every node must have a "pos" attribute + for n, pos in G.nodes(data=pos_name): + if pos is None: + raise nx.NetworkXError( + f"Node {n} (and all nodes) must have a '{pos_name}' attribute." + ) + + # NOTE: See _geometric_edges for the actual implementation. The reason this + # is split into two functions is to avoid the overhead of input validation + # every time the function is called internally in one of the other + # geometric generators + return _geometric_edges(G, radius, p, pos_name) + + +def _geometric_edges(G, radius, p, pos_name): + """ + Implements `geometric_edges` without input validation. See `geometric_edges` + for complete docstring. + """ + nodes_pos = G.nodes(data=pos_name) + try: + import scipy as sp + except ImportError: + # no scipy KDTree so compute by for-loop + radius_p = radius**p + edges = [ + (u, v) + for (u, pu), (v, pv) in combinations(nodes_pos, 2) + if sum(abs(a - b) ** p for a, b in zip(pu, pv)) <= radius_p + ] + return edges + # scipy KDTree is available + nodes, coords = list(zip(*nodes_pos)) + kdtree = sp.spatial.cKDTree(coords) # Cannot provide generator. + edge_indexes = kdtree.query_pairs(radius, p) + edges = [(nodes[u], nodes[v]) for u, v in sorted(edge_indexes)] + return edges + + +@py_random_state(5) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_geometric_graph( + n, radius, dim=2, pos=None, p=2, seed=None, *, pos_name="pos" +): + """Returns a random geometric graph in the unit cube of dimensions `dim`. + + The random geometric graph model places `n` nodes uniformly at + random in the unit cube. Two nodes are joined by an edge if the + distance between the nodes is at most `radius`. + + Edges are determined using a KDTree when SciPy is available. + This reduces the time complexity from $O(n^2)$ to $O(n)$. + + Parameters + ---------- + n : int or iterable + Number of nodes or iterable of nodes + radius: float + Distance threshold value + dim : int, optional + Dimension of graph + pos : dict, optional + A dictionary keyed by node with node positions as values. + p : float, optional + Which Minkowski distance metric to use. `p` has to meet the condition + ``1 <= p <= infinity``. + + If this argument is not specified, the :math:`L^2` metric + (the Euclidean distance metric), p = 2 is used. + This should not be confused with the `p` of an Erdős-Rényi random + graph, which represents probability. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + pos_name : string, default="pos" + The name of the node attribute which represents the position + in 2D coordinates of the node in the returned graph. + + Returns + ------- + Graph + A random geometric graph, undirected and without self-loops. + Each node has a node attribute ``'pos'`` that stores the + position of that node in Euclidean space as provided by the + ``pos`` keyword argument or, if ``pos`` was not provided, as + generated by this function. + + Examples + -------- + Create a random geometric graph on twenty nodes where nodes are joined by + an edge if their distance is at most 0.1:: + + >>> G = nx.random_geometric_graph(20, 0.1) + + Notes + ----- + This uses a *k*-d tree to build the graph. + + The `pos` keyword argument can be used to specify node positions so you + can create an arbitrary distribution and domain for positions. + + For example, to use a 2D Gaussian distribution of node positions with mean + (0, 0) and standard deviation 2:: + + >>> import random + >>> n = 20 + >>> pos = {i: (random.gauss(0, 2), random.gauss(0, 2)) for i in range(n)} + >>> G = nx.random_geometric_graph(n, 0.2, pos=pos) + + References + ---------- + .. [1] Penrose, Mathew, *Random Geometric Graphs*, + Oxford Studies in Probability, 5, 2003. + + """ + # TODO Is this function just a special case of the geographical + # threshold graph? + # + # half_radius = {v: radius / 2 for v in n} + # return geographical_threshold_graph(nodes, theta=1, alpha=1, + # weight=half_radius) + # + G = nx.empty_graph(n) + # If no positions are provided, choose uniformly random vectors in + # Euclidean space of the specified dimension. + if pos is None: + pos = {v: [seed.random() for i in range(dim)] for v in G} + nx.set_node_attributes(G, pos, pos_name) + + G.add_edges_from(_geometric_edges(G, radius, p, pos_name)) + return G + + +@py_random_state(6) +@nx._dispatchable(graphs=None, returns_graph=True) +def soft_random_geometric_graph( + n, radius, dim=2, pos=None, p=2, p_dist=None, seed=None, *, pos_name="pos" +): + r"""Returns a soft random geometric graph in the unit cube. + + The soft random geometric graph [1] model places `n` nodes uniformly at + random in the unit cube in dimension `dim`. Two nodes of distance, `dist`, + computed by the `p`-Minkowski distance metric are joined by an edge with + probability `p_dist` if the computed distance metric value of the nodes + is at most `radius`, otherwise they are not joined. + + Edges within `radius` of each other are determined using a KDTree when + SciPy is available. This reduces the time complexity from :math:`O(n^2)` + to :math:`O(n)`. + + Parameters + ---------- + n : int or iterable + Number of nodes or iterable of nodes + radius: float + Distance threshold value + dim : int, optional + Dimension of graph + pos : dict, optional + A dictionary keyed by node with node positions as values. + p : float, optional + Which Minkowski distance metric to use. + `p` has to meet the condition ``1 <= p <= infinity``. + + If this argument is not specified, the :math:`L^2` metric + (the Euclidean distance metric), p = 2 is used. + + This should not be confused with the `p` of an Erdős-Rényi random + graph, which represents probability. + p_dist : function, optional + A probability density function computing the probability of + connecting two nodes that are of distance, dist, computed by the + Minkowski distance metric. The probability density function, `p_dist`, + must be any function that takes the metric value as input + and outputs a single probability value between 0-1. The scipy.stats + package has many probability distribution functions implemented and + tools for custom probability distribution definitions [2], and passing + the .pdf method of scipy.stats distributions can be used here. If the + probability function, `p_dist`, is not supplied, the default function + is an exponential distribution with rate parameter :math:`\lambda=1`. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + pos_name : string, default="pos" + The name of the node attribute which represents the position + in 2D coordinates of the node in the returned graph. + + Returns + ------- + Graph + A soft random geometric graph, undirected and without self-loops. + Each node has a node attribute ``'pos'`` that stores the + position of that node in Euclidean space as provided by the + ``pos`` keyword argument or, if ``pos`` was not provided, as + generated by this function. + + Examples + -------- + Default Graph: + + G = nx.soft_random_geometric_graph(50, 0.2) + + Custom Graph: + + Create a soft random geometric graph on 100 uniformly distributed nodes + where nodes are joined by an edge with probability computed from an + exponential distribution with rate parameter :math:`\lambda=1` if their + Euclidean distance is at most 0.2. + + Notes + ----- + This uses a *k*-d tree to build the graph. + + The `pos` keyword argument can be used to specify node positions so you + can create an arbitrary distribution and domain for positions. + + For example, to use a 2D Gaussian distribution of node positions with mean + (0, 0) and standard deviation 2 + + The scipy.stats package can be used to define the probability distribution + with the .pdf method used as `p_dist`. + + :: + + >>> import random + >>> import math + >>> n = 100 + >>> pos = {i: (random.gauss(0, 2), random.gauss(0, 2)) for i in range(n)} + >>> p_dist = lambda dist: math.exp(-dist) + >>> G = nx.soft_random_geometric_graph(n, 0.2, pos=pos, p_dist=p_dist) + + References + ---------- + .. [1] Penrose, Mathew D. "Connectivity of soft random geometric graphs." + The Annals of Applied Probability 26.2 (2016): 986-1028. + .. [2] scipy.stats - + https://docs.scipy.org/doc/scipy/reference/tutorial/stats.html + + """ + G = nx.empty_graph(n) + G.name = f"soft_random_geometric_graph({n}, {radius}, {dim})" + # If no positions are provided, choose uniformly random vectors in + # Euclidean space of the specified dimension. + if pos is None: + pos = {v: [seed.random() for i in range(dim)] for v in G} + nx.set_node_attributes(G, pos, pos_name) + + # if p_dist function not supplied the default function is an exponential + # distribution with rate parameter :math:`\lambda=1`. + if p_dist is None: + + def p_dist(dist): + return math.exp(-dist) + + def should_join(edge): + u, v = edge + dist = (sum(abs(a - b) ** p for a, b in zip(pos[u], pos[v]))) ** (1 / p) + return seed.random() < p_dist(dist) + + G.add_edges_from(filter(should_join, _geometric_edges(G, radius, p, pos_name))) + return G + + +@py_random_state(7) +@nx._dispatchable(graphs=None, returns_graph=True) +def geographical_threshold_graph( + n, + theta, + dim=2, + pos=None, + weight=None, + metric=None, + p_dist=None, + seed=None, + *, + pos_name="pos", + weight_name="weight", +): + r"""Returns a geographical threshold graph. + + The geographical threshold graph model places $n$ nodes uniformly at + random in a rectangular domain. Each node $u$ is assigned a weight + $w_u$. Two nodes $u$ and $v$ are joined by an edge if + + .. math:: + + (w_u + w_v)p_{dist}(r) \ge \theta + + where `r` is the distance between `u` and `v`, `p_dist` is any function of + `r`, and :math:`\theta` as the threshold parameter. `p_dist` is used to + give weight to the distance between nodes when deciding whether or not + they should be connected. The larger `p_dist` is, the more prone nodes + separated by `r` are to be connected, and vice versa. + + Parameters + ---------- + n : int or iterable + Number of nodes or iterable of nodes + theta: float + Threshold value + dim : int, optional + Dimension of graph + pos : dict + Node positions as a dictionary of tuples keyed by node. + weight : dict + Node weights as a dictionary of numbers keyed by node. + metric : function + A metric on vectors of numbers (represented as lists or + tuples). This must be a function that accepts two lists (or + tuples) as input and yields a number as output. The function + must also satisfy the four requirements of a `metric`_. + Specifically, if $d$ is the function and $x$, $y$, + and $z$ are vectors in the graph, then $d$ must satisfy + + 1. $d(x, y) \ge 0$, + 2. $d(x, y) = 0$ if and only if $x = y$, + 3. $d(x, y) = d(y, x)$, + 4. $d(x, z) \le d(x, y) + d(y, z)$. + + If this argument is not specified, the Euclidean distance metric is + used. + + .. _metric: https://en.wikipedia.org/wiki/Metric_%28mathematics%29 + p_dist : function, optional + Any function used to give weight to the distance between nodes when + deciding whether or not they should be connected. `p_dist` was + originally conceived as a probability density function giving the + probability of connecting two nodes that are of metric distance `r` + apart. The implementation here allows for more arbitrary definitions + of `p_dist` that do not need to correspond to valid probability + density functions. The :mod:`scipy.stats` package has many + probability density functions implemented and tools for custom + probability density definitions, and passing the ``.pdf`` method of + scipy.stats distributions can be used here. If ``p_dist=None`` + (the default), the exponential function :math:`r^{-2}` is used. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + pos_name : string, default="pos" + The name of the node attribute which represents the position + in 2D coordinates of the node in the returned graph. + weight_name : string, default="weight" + The name of the node attribute which represents the weight + of the node in the returned graph. + + Returns + ------- + Graph + A random geographic threshold graph, undirected and without + self-loops. + + Each node has a node attribute ``pos`` that stores the + position of that node in Euclidean space as provided by the + ``pos`` keyword argument or, if ``pos`` was not provided, as + generated by this function. Similarly, each node has a node + attribute ``weight`` that stores the weight of that node as + provided or as generated. + + Examples + -------- + Specify an alternate distance metric using the ``metric`` keyword + argument. For example, to use the `taxicab metric`_ instead of the + default `Euclidean metric`_:: + + >>> dist = lambda x, y: sum(abs(a - b) for a, b in zip(x, y)) + >>> G = nx.geographical_threshold_graph(10, 0.1, metric=dist) + + .. _taxicab metric: https://en.wikipedia.org/wiki/Taxicab_geometry + .. _Euclidean metric: https://en.wikipedia.org/wiki/Euclidean_distance + + Notes + ----- + If weights are not specified they are assigned to nodes by drawing randomly + from the exponential distribution with rate parameter $\lambda=1$. + To specify weights from a different distribution, use the `weight` keyword + argument:: + + >>> import random + >>> n = 20 + >>> w = {i: random.expovariate(5.0) for i in range(n)} + >>> G = nx.geographical_threshold_graph(20, 50, weight=w) + + If node positions are not specified they are randomly assigned from the + uniform distribution. + + References + ---------- + .. [1] Masuda, N., Miwa, H., Konno, N.: + Geographical threshold graphs with small-world and scale-free + properties. + Physical Review E 71, 036108 (2005) + .. [2] Milan Bradonjić, Aric Hagberg and Allon G. Percus, + Giant component and connectivity in geographical threshold graphs, + in Algorithms and Models for the Web-Graph (WAW 2007), + Antony Bonato and Fan Chung (Eds), pp. 209--216, 2007 + """ + G = nx.empty_graph(n) + # If no weights are provided, choose them from an exponential + # distribution. + if weight is None: + weight = {v: seed.expovariate(1) for v in G} + # If no positions are provided, choose uniformly random vectors in + # Euclidean space of the specified dimension. + if pos is None: + pos = {v: [seed.random() for i in range(dim)] for v in G} + # If no distance metric is provided, use Euclidean distance. + if metric is None: + metric = math.dist + nx.set_node_attributes(G, weight, weight_name) + nx.set_node_attributes(G, pos, pos_name) + + # if p_dist is not supplied, use default r^-2 + if p_dist is None: + + def p_dist(r): + return r**-2 + + # Returns ``True`` if and only if the nodes whose attributes are + # ``du`` and ``dv`` should be joined, according to the threshold + # condition. + def should_join(pair): + u, v = pair + u_pos, v_pos = pos[u], pos[v] + u_weight, v_weight = weight[u], weight[v] + return (u_weight + v_weight) * p_dist(metric(u_pos, v_pos)) >= theta + + G.add_edges_from(filter(should_join, combinations(G, 2))) + return G + + +@py_random_state(6) +@nx._dispatchable(graphs=None, returns_graph=True) +def waxman_graph( + n, + beta=0.4, + alpha=0.1, + L=None, + domain=(0, 0, 1, 1), + metric=None, + seed=None, + *, + pos_name="pos", +): + r"""Returns a Waxman random graph. + + The Waxman random graph model places `n` nodes uniformly at random + in a rectangular domain. Each pair of nodes at distance `d` is + joined by an edge with probability + + .. math:: + p = \beta \exp(-d / \alpha L). + + This function implements both Waxman models, using the `L` keyword + argument. + + * Waxman-1: if `L` is not specified, it is set to be the maximum distance + between any pair of nodes. + * Waxman-2: if `L` is specified, the distance between a pair of nodes is + chosen uniformly at random from the interval `[0, L]`. + + Parameters + ---------- + n : int or iterable + Number of nodes or iterable of nodes + beta: float + Model parameter + alpha: float + Model parameter + L : float, optional + Maximum distance between nodes. If not specified, the actual distance + is calculated. + domain : four-tuple of numbers, optional + Domain size, given as a tuple of the form `(x_min, y_min, x_max, + y_max)`. + metric : function + A metric on vectors of numbers (represented as lists or + tuples). This must be a function that accepts two lists (or + tuples) as input and yields a number as output. The function + must also satisfy the four requirements of a `metric`_. + Specifically, if $d$ is the function and $x$, $y$, + and $z$ are vectors in the graph, then $d$ must satisfy + + 1. $d(x, y) \ge 0$, + 2. $d(x, y) = 0$ if and only if $x = y$, + 3. $d(x, y) = d(y, x)$, + 4. $d(x, z) \le d(x, y) + d(y, z)$. + + If this argument is not specified, the Euclidean distance metric is + used. + + .. _metric: https://en.wikipedia.org/wiki/Metric_%28mathematics%29 + + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + pos_name : string, default="pos" + The name of the node attribute which represents the position + in 2D coordinates of the node in the returned graph. + + Returns + ------- + Graph + A random Waxman graph, undirected and without self-loops. Each + node has a node attribute ``'pos'`` that stores the position of + that node in Euclidean space as generated by this function. + + Examples + -------- + Specify an alternate distance metric using the ``metric`` keyword + argument. For example, to use the "`taxicab metric`_" instead of the + default `Euclidean metric`_:: + + >>> dist = lambda x, y: sum(abs(a - b) for a, b in zip(x, y)) + >>> G = nx.waxman_graph(10, 0.5, 0.1, metric=dist) + + .. _taxicab metric: https://en.wikipedia.org/wiki/Taxicab_geometry + .. _Euclidean metric: https://en.wikipedia.org/wiki/Euclidean_distance + + Notes + ----- + Starting in NetworkX 2.0 the parameters alpha and beta align with their + usual roles in the probability distribution. In earlier versions their + positions in the expression were reversed. Their position in the calling + sequence reversed as well to minimize backward incompatibility. + + References + ---------- + .. [1] B. M. Waxman, *Routing of multipoint connections*. + IEEE J. Select. Areas Commun. 6(9),(1988) 1617--1622. + """ + G = nx.empty_graph(n) + (xmin, ymin, xmax, ymax) = domain + # Each node gets a uniformly random position in the given rectangle. + pos = {v: (seed.uniform(xmin, xmax), seed.uniform(ymin, ymax)) for v in G} + nx.set_node_attributes(G, pos, pos_name) + # If no distance metric is provided, use Euclidean distance. + if metric is None: + metric = math.dist + # If the maximum distance L is not specified (that is, we are in the + # Waxman-1 model), then find the maximum distance between any pair + # of nodes. + # + # In the Waxman-1 model, join nodes randomly based on distance. In + # the Waxman-2 model, join randomly based on random l. + if L is None: + L = max(metric(x, y) for x, y in combinations(pos.values(), 2)) + + def dist(u, v): + return metric(pos[u], pos[v]) + + else: + + def dist(u, v): + return seed.random() * L + + # `pair` is the pair of nodes to decide whether to join. + def should_join(pair): + return seed.random() < beta * math.exp(-dist(*pair) / (alpha * L)) + + G.add_edges_from(filter(should_join, combinations(G, 2))) + return G + + +@py_random_state(5) +@nx._dispatchable(graphs=None, returns_graph=True) +def navigable_small_world_graph(n, p=1, q=1, r=2, dim=2, seed=None): + r"""Returns a navigable small-world graph. + + A navigable small-world graph is a directed grid with additional long-range + connections that are chosen randomly. + + [...] we begin with a set of nodes [...] that are identified with the set + of lattice points in an $n \times n$ square, + $\{(i, j): i \in \{1, 2, \ldots, n\}, j \in \{1, 2, \ldots, n\}\}$, + and we define the *lattice distance* between two nodes $(i, j)$ and + $(k, l)$ to be the number of "lattice steps" separating them: + $d((i, j), (k, l)) = |k - i| + |l - j|$. + + For a universal constant $p >= 1$, the node $u$ has a directed edge to + every other node within lattice distance $p$---these are its *local + contacts*. For universal constants $q >= 0$ and $r >= 0$ we also + construct directed edges from $u$ to $q$ other nodes (the *long-range + contacts*) using independent random trials; the $i$th directed edge from + $u$ has endpoint $v$ with probability proportional to $[d(u,v)]^{-r}$. + + -- [1]_ + + Parameters + ---------- + n : int + The length of one side of the lattice; the number of nodes in + the graph is therefore $n^2$. + p : int + The diameter of short range connections. Each node is joined with every + other node within this lattice distance. + q : int + The number of long-range connections for each node. + r : float + Exponent for decaying probability of connections. The probability of + connecting to a node at lattice distance $d$ is $1/d^r$. + dim : int + Dimension of grid + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + References + ---------- + .. [1] J. Kleinberg. The small-world phenomenon: An algorithmic + perspective. Proc. 32nd ACM Symposium on Theory of Computing, 2000. + """ + if p < 1: + raise nx.NetworkXException("p must be >= 1") + if q < 0: + raise nx.NetworkXException("q must be >= 0") + if r < 0: + raise nx.NetworkXException("r must be >= 0") + + G = nx.DiGraph() + nodes = list(product(range(n), repeat=dim)) + for p1 in nodes: + probs = [0] + for p2 in nodes: + if p1 == p2: + continue + d = sum((abs(b - a) for a, b in zip(p1, p2))) + if d <= p: + G.add_edge(p1, p2) + probs.append(d**-r) + cdf = list(accumulate(probs)) + for _ in range(q): + target = nodes[bisect_left(cdf, seed.uniform(0, cdf[-1]))] + G.add_edge(p1, target) + return G + + +@py_random_state(7) +@nx._dispatchable(graphs=None, returns_graph=True) +def thresholded_random_geometric_graph( + n, + radius, + theta, + dim=2, + pos=None, + weight=None, + p=2, + seed=None, + *, + pos_name="pos", + weight_name="weight", +): + r"""Returns a thresholded random geometric graph in the unit cube. + + The thresholded random geometric graph [1] model places `n` nodes + uniformly at random in the unit cube of dimensions `dim`. Each node + `u` is assigned a weight :math:`w_u`. Two nodes `u` and `v` are + joined by an edge if they are within the maximum connection distance, + `radius` computed by the `p`-Minkowski distance and the summation of + weights :math:`w_u` + :math:`w_v` is greater than or equal + to the threshold parameter `theta`. + + Edges within `radius` of each other are determined using a KDTree when + SciPy is available. This reduces the time complexity from :math:`O(n^2)` + to :math:`O(n)`. + + Parameters + ---------- + n : int or iterable + Number of nodes or iterable of nodes + radius: float + Distance threshold value + theta: float + Threshold value + dim : int, optional + Dimension of graph + pos : dict, optional + A dictionary keyed by node with node positions as values. + weight : dict, optional + Node weights as a dictionary of numbers keyed by node. + p : float, optional (default 2) + Which Minkowski distance metric to use. `p` has to meet the condition + ``1 <= p <= infinity``. + + If this argument is not specified, the :math:`L^2` metric + (the Euclidean distance metric), p = 2 is used. + + This should not be confused with the `p` of an Erdős-Rényi random + graph, which represents probability. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + pos_name : string, default="pos" + The name of the node attribute which represents the position + in 2D coordinates of the node in the returned graph. + weight_name : string, default="weight" + The name of the node attribute which represents the weight + of the node in the returned graph. + + Returns + ------- + Graph + A thresholded random geographic graph, undirected and without + self-loops. + + Each node has a node attribute ``'pos'`` that stores the + position of that node in Euclidean space as provided by the + ``pos`` keyword argument or, if ``pos`` was not provided, as + generated by this function. Similarly, each node has a nodethre + attribute ``'weight'`` that stores the weight of that node as + provided or as generated. + + Examples + -------- + Default Graph: + + G = nx.thresholded_random_geometric_graph(50, 0.2, 0.1) + + Custom Graph: + + Create a thresholded random geometric graph on 50 uniformly distributed + nodes where nodes are joined by an edge if their sum weights drawn from + a exponential distribution with rate = 5 are >= theta = 0.1 and their + Euclidean distance is at most 0.2. + + Notes + ----- + This uses a *k*-d tree to build the graph. + + The `pos` keyword argument can be used to specify node positions so you + can create an arbitrary distribution and domain for positions. + + For example, to use a 2D Gaussian distribution of node positions with mean + (0, 0) and standard deviation 2 + + If weights are not specified they are assigned to nodes by drawing randomly + from the exponential distribution with rate parameter :math:`\lambda=1`. + To specify weights from a different distribution, use the `weight` keyword + argument:: + + :: + + >>> import random + >>> import math + >>> n = 50 + >>> pos = {i: (random.gauss(0, 2), random.gauss(0, 2)) for i in range(n)} + >>> w = {i: random.expovariate(5.0) for i in range(n)} + >>> G = nx.thresholded_random_geometric_graph(n, 0.2, 0.1, 2, pos, w) + + References + ---------- + .. [1] http://cole-maclean.github.io/blog/files/thesis.pdf + + """ + G = nx.empty_graph(n) + G.name = f"thresholded_random_geometric_graph({n}, {radius}, {theta}, {dim})" + # If no weights are provided, choose them from an exponential + # distribution. + if weight is None: + weight = {v: seed.expovariate(1) for v in G} + # If no positions are provided, choose uniformly random vectors in + # Euclidean space of the specified dimension. + if pos is None: + pos = {v: [seed.random() for i in range(dim)] for v in G} + # If no distance metric is provided, use Euclidean distance. + nx.set_node_attributes(G, weight, weight_name) + nx.set_node_attributes(G, pos, pos_name) + + edges = ( + (u, v) + for u, v in _geometric_edges(G, radius, p, pos_name) + if weight[u] + weight[v] >= theta + ) + G.add_edges_from(edges) + return G + + +@py_random_state(5) +@nx._dispatchable(graphs=None, returns_graph=True) +def geometric_soft_configuration_graph( + *, beta, n=None, gamma=None, mean_degree=None, kappas=None, seed=None +): + r"""Returns a random graph from the geometric soft configuration model. + + The $\mathbb{S}^1$ model [1]_ is the geometric soft configuration model + which is able to explain many fundamental features of real networks such as + small-world property, heteregenous degree distributions, high level of + clustering, and self-similarity. + + In the geometric soft configuration model, a node $i$ is assigned two hidden + variables: a hidden degree $\kappa_i$, quantifying its popularity, influence, + or importance, and an angular position $\theta_i$ in a circle abstracting the + similarity space, where angular distances between nodes are a proxy for their + similarity. Focusing on the angular position, this model is often called + the $\mathbb{S}^1$ model (a one-dimensional sphere). The circle's radius is + adjusted to $R = N/2\pi$, where $N$ is the number of nodes, so that the density + is set to 1 without loss of generality. + + The connection probability between any pair of nodes increases with + the product of their hidden degrees (i.e., their combined popularities), + and decreases with the angular distance between the two nodes. + Specifically, nodes $i$ and $j$ are connected with the probability + + $p_{ij} = \frac{1}{1 + \frac{d_{ij}^\beta}{\left(\mu \kappa_i \kappa_j\right)^{\max(1, \beta)}}}$ + + where $d_{ij} = R\Delta\theta_{ij}$ is the arc length of the circle between + nodes $i$ and $j$ separated by an angular distance $\Delta\theta_{ij}$. + Parameters $\mu$ and $\beta$ (also called inverse temperature) control the + average degree and the clustering coefficient, respectively. + + It can be shown [2]_ that the model undergoes a structural phase transition + at $\beta=1$ so that for $\beta<1$ networks are unclustered in the thermodynamic + limit (when $N\to \infty$) whereas for $\beta>1$ the ensemble generates + networks with finite clustering coefficient. + + The $\mathbb{S}^1$ model can be expressed as a purely geometric model + $\mathbb{H}^2$ in the hyperbolic plane [3]_ by mapping the hidden degree of + each node into a radial coordinate as + + $r_i = \hat{R} - \frac{2 \max(1, \beta)}{\beta \zeta} \ln \left(\frac{\kappa_i}{\kappa_0}\right)$ + + where $\hat{R}$ is the radius of the hyperbolic disk and $\zeta$ is the curvature, + + $\hat{R} = \frac{2}{\zeta} \ln \left(\frac{N}{\pi}\right) + - \frac{2\max(1, \beta)}{\beta \zeta} \ln (\mu \kappa_0^2)$ + + The connection probability then reads + + $p_{ij} = \frac{1}{1 + \exp\left({\frac{\beta\zeta}{2} (x_{ij} - \hat{R})}\right)}$ + + where + + $x_{ij} = r_i + r_j + \frac{2}{\zeta} \ln \frac{\Delta\theta_{ij}}{2}$ + + is a good approximation of the hyperbolic distance between two nodes separated + by an angular distance $\Delta\theta_{ij}$ with radial coordinates $r_i$ and $r_j$. + For $\beta > 1$, the curvature $\zeta = 1$, for $\beta < 1$, $\zeta = \beta^{-1}$. + + + Parameters + ---------- + Either `n`, `gamma`, `mean_degree` are provided or `kappas`. The values of + `n`, `gamma`, `mean_degree` (if provided) are used to construct a random + kappa-dict keyed by node with values sampled from a power-law distribution. + + beta : positive number + Inverse temperature, controlling the clustering coefficient. + n : int (default: None) + Size of the network (number of nodes). + If not provided, `kappas` must be provided and holds the nodes. + gamma : float (default: None) + Exponent of the power-law distribution for hidden degrees `kappas`. + If not provided, `kappas` must be provided directly. + mean_degree : float (default: None) + The mean degree in the network. + If not provided, `kappas` must be provided directly. + kappas : dict (default: None) + A dict keyed by node to its hidden degree value. + If not provided, random values are computed based on a power-law + distribution using `n`, `gamma` and `mean_degree`. + seed : int, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + Graph + A random geometric soft configuration graph (undirected with no self-loops). + Each node has three node-attributes: + + - ``kappa`` that represents the hidden degree. + + - ``theta`` the position in the similarity space ($\mathbb{S}^1$) which is + also the angular position in the hyperbolic plane. + + - ``radius`` the radial position in the hyperbolic plane + (based on the hidden degree). + + + Examples + -------- + Generate a network with specified parameters: + + >>> G = nx.geometric_soft_configuration_graph( + ... beta=1.5, n=100, gamma=2.7, mean_degree=5 + ... ) + + Create a geometric soft configuration graph with 100 nodes. The $\beta$ parameter + is set to 1.5 and the exponent of the powerlaw distribution of the hidden + degrees is 2.7 with mean value of 5. + + Generate a network with predefined hidden degrees: + + >>> kappas = {i: 10 for i in range(100)} + >>> G = nx.geometric_soft_configuration_graph(beta=2.5, kappas=kappas) + + Create a geometric soft configuration graph with 100 nodes. The $\beta$ parameter + is set to 2.5 and all nodes with hidden degree $\kappa=10$. + + + References + ---------- + .. [1] Serrano, M. Á., Krioukov, D., & Boguñá, M. (2008). Self-similarity + of complex networks and hidden metric spaces. Physical review letters, 100(7), 078701. + + .. [2] van der Kolk, J., Serrano, M. Á., & Boguñá, M. (2022). An anomalous + topological phase transition in spatial random graphs. Communications Physics, 5(1), 245. + + .. [3] Krioukov, D., Papadopoulos, F., Kitsak, M., Vahdat, A., & Boguná, M. (2010). + Hyperbolic geometry of complex networks. Physical Review E, 82(3), 036106. + + """ + if beta <= 0: + raise nx.NetworkXError("The parameter beta cannot be smaller or equal to 0.") + + if kappas is not None: + if not all((n is None, gamma is None, mean_degree is None)): + raise nx.NetworkXError( + "When kappas is input, n, gamma and mean_degree must not be." + ) + + n = len(kappas) + mean_degree = sum(kappas) / len(kappas) + else: + if any((n is None, gamma is None, mean_degree is None)): + raise nx.NetworkXError( + "Please provide either kappas, or all 3 of: n, gamma and mean_degree." + ) + + # Generate `n` hidden degrees from a powerlaw distribution + # with given exponent `gamma` and mean value `mean_degree` + gam_ratio = (gamma - 2) / (gamma - 1) + kappa_0 = mean_degree * gam_ratio * (1 - 1 / n) / (1 - 1 / n**gam_ratio) + base = 1 - 1 / n + power = 1 / (1 - gamma) + kappas = {i: kappa_0 * (1 - seed.random() * base) ** power for i in range(n)} + + G = nx.Graph() + R = n / (2 * math.pi) + + # Approximate values for mu in the thermodynamic limit (when n -> infinity) + if beta > 1: + mu = beta * math.sin(math.pi / beta) / (2 * math.pi * mean_degree) + elif beta == 1: + mu = 1 / (2 * mean_degree * math.log(n)) + else: + mu = (1 - beta) / (2**beta * mean_degree * n ** (1 - beta)) + + # Generate random positions on a circle + thetas = {k: seed.uniform(0, 2 * math.pi) for k in kappas} + + for u in kappas: + for v in list(G): + angle = math.pi - math.fabs(math.pi - math.fabs(thetas[u] - thetas[v])) + dij = math.pow(R * angle, beta) + mu_kappas = math.pow(mu * kappas[u] * kappas[v], max(1, beta)) + p_ij = 1 / (1 + dij / mu_kappas) + + # Create an edge with a certain connection probability + if seed.random() < p_ij: + G.add_edge(u, v) + G.add_node(u) + + nx.set_node_attributes(G, thetas, "theta") + nx.set_node_attributes(G, kappas, "kappa") + + # Map hidden degrees into the radial coordinates + zeta = 1 if beta > 1 else 1 / beta + kappa_min = min(kappas.values()) + R_c = 2 * max(1, beta) / (beta * zeta) + R_hat = (2 / zeta) * math.log(n / math.pi) - R_c * math.log(mu * kappa_min) + radii = {node: R_hat - R_c * math.log(kappa) for node, kappa in kappas.items()} + nx.set_node_attributes(G, radii, "radius") + + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/harary_graph.py b/janus/lib/python3.10/site-packages/networkx/generators/harary_graph.py new file mode 100644 index 0000000000000000000000000000000000000000..591587d3aca68176a1d781eb1900b0feb04567e4 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/harary_graph.py @@ -0,0 +1,199 @@ +"""Generators for Harary graphs + +This module gives two generators for the Harary graph, which was +introduced by the famous mathematician Frank Harary in his 1962 work [H]_. +The first generator gives the Harary graph that maximizes the node +connectivity with given number of nodes and given number of edges. +The second generator gives the Harary graph that minimizes +the number of edges in the graph with given node connectivity and +number of nodes. + +References +---------- +.. [H] Harary, F. "The Maximum Connectivity of a Graph." + Proc. Nat. Acad. Sci. USA 48, 1142-1146, 1962. + +""" + +import networkx as nx +from networkx.exception import NetworkXError + +__all__ = ["hnm_harary_graph", "hkn_harary_graph"] + + +@nx._dispatchable(graphs=None, returns_graph=True) +def hnm_harary_graph(n, m, create_using=None): + """Returns the Harary graph with given numbers of nodes and edges. + + The Harary graph $H_{n,m}$ is the graph that maximizes node connectivity + with $n$ nodes and $m$ edges. + + This maximum node connectivity is known to be floor($2m/n$). [1]_ + + Parameters + ---------- + n: integer + The number of nodes the generated graph is to contain + + m: integer + The number of edges the generated graph is to contain + + create_using : NetworkX graph constructor, optional Graph type + to create (default=nx.Graph). If graph instance, then cleared + before populated. + + Returns + ------- + NetworkX graph + The Harary graph $H_{n,m}$. + + See Also + -------- + hkn_harary_graph + + Notes + ----- + This algorithm runs in $O(m)$ time. + It is implemented by following the Reference [2]_. + + References + ---------- + .. [1] F. T. Boesch, A. Satyanarayana, and C. L. Suffel, + "A Survey of Some Network Reliability Analysis and Synthesis Results," + Networks, pp. 99-107, 2009. + + .. [2] Harary, F. "The Maximum Connectivity of a Graph." + Proc. Nat. Acad. Sci. USA 48, 1142-1146, 1962. + """ + + if n < 1: + raise NetworkXError("The number of nodes must be >= 1!") + if m < n - 1: + raise NetworkXError("The number of edges must be >= n - 1 !") + if m > n * (n - 1) // 2: + raise NetworkXError("The number of edges must be <= n(n-1)/2") + + # Construct an empty graph with n nodes first + H = nx.empty_graph(n, create_using) + # Get the floor of average node degree + d = 2 * m // n + + # Test the parity of n and d + if (n % 2 == 0) or (d % 2 == 0): + # Start with a regular graph of d degrees + offset = d // 2 + for i in range(n): + for j in range(1, offset + 1): + H.add_edge(i, (i - j) % n) + H.add_edge(i, (i + j) % n) + if d & 1: + # in case d is odd; n must be even in this case + half = n // 2 + for i in range(half): + # add edges diagonally + H.add_edge(i, i + half) + # Get the remainder of 2*m modulo n + r = 2 * m % n + if r > 0: + # add remaining edges at offset+1 + for i in range(r // 2): + H.add_edge(i, i + offset + 1) + else: + # Start with a regular graph of (d - 1) degrees + offset = (d - 1) // 2 + for i in range(n): + for j in range(1, offset + 1): + H.add_edge(i, (i - j) % n) + H.add_edge(i, (i + j) % n) + half = n // 2 + for i in range(m - n * offset): + # add the remaining m - n*offset edges between i and i+half + H.add_edge(i, (i + half) % n) + + return H + + +@nx._dispatchable(graphs=None, returns_graph=True) +def hkn_harary_graph(k, n, create_using=None): + """Returns the Harary graph with given node connectivity and node number. + + The Harary graph $H_{k,n}$ is the graph that minimizes the number of + edges needed with given node connectivity $k$ and node number $n$. + + This smallest number of edges is known to be ceil($kn/2$) [1]_. + + Parameters + ---------- + k: integer + The node connectivity of the generated graph + + n: integer + The number of nodes the generated graph is to contain + + create_using : NetworkX graph constructor, optional Graph type + to create (default=nx.Graph). If graph instance, then cleared + before populated. + + Returns + ------- + NetworkX graph + The Harary graph $H_{k,n}$. + + See Also + -------- + hnm_harary_graph + + Notes + ----- + This algorithm runs in $O(kn)$ time. + It is implemented by following the Reference [2]_. + + References + ---------- + .. [1] Weisstein, Eric W. "Harary Graph." From MathWorld--A Wolfram Web + Resource. http://mathworld.wolfram.com/HararyGraph.html. + + .. [2] Harary, F. "The Maximum Connectivity of a Graph." + Proc. Nat. Acad. Sci. USA 48, 1142-1146, 1962. + """ + + if k < 1: + raise NetworkXError("The node connectivity must be >= 1!") + if n < k + 1: + raise NetworkXError("The number of nodes must be >= k+1 !") + + # in case of connectivity 1, simply return the path graph + if k == 1: + H = nx.path_graph(n, create_using) + return H + + # Construct an empty graph with n nodes first + H = nx.empty_graph(n, create_using) + + # Test the parity of k and n + if (k % 2 == 0) or (n % 2 == 0): + # Construct a regular graph with k degrees + offset = k // 2 + for i in range(n): + for j in range(1, offset + 1): + H.add_edge(i, (i - j) % n) + H.add_edge(i, (i + j) % n) + if k & 1: + # odd degree; n must be even in this case + half = n // 2 + for i in range(half): + # add edges diagonally + H.add_edge(i, i + half) + else: + # Construct a regular graph with (k - 1) degrees + offset = (k - 1) // 2 + for i in range(n): + for j in range(1, offset + 1): + H.add_edge(i, (i - j) % n) + H.add_edge(i, (i + j) % n) + half = n // 2 + for i in range(half + 1): + # add half+1 edges between i and i+half + H.add_edge(i, (i + half) % n) + + return H diff --git a/janus/lib/python3.10/site-packages/networkx/generators/interval_graph.py b/janus/lib/python3.10/site-packages/networkx/generators/interval_graph.py new file mode 100644 index 0000000000000000000000000000000000000000..6a3fda45acec52af6a5f060b96d9af1067fc002b --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/interval_graph.py @@ -0,0 +1,70 @@ +""" +Generators for interval graph. +""" + +from collections.abc import Sequence + +import networkx as nx + +__all__ = ["interval_graph"] + + +@nx._dispatchable(graphs=None, returns_graph=True) +def interval_graph(intervals): + """Generates an interval graph for a list of intervals given. + + In graph theory, an interval graph is an undirected graph formed from a set + of closed intervals on the real line, with a vertex for each interval + and an edge between vertices whose intervals intersect. + It is the intersection graph of the intervals. + + More information can be found at: + https://en.wikipedia.org/wiki/Interval_graph + + Parameters + ---------- + intervals : a sequence of intervals, say (l, r) where l is the left end, + and r is the right end of the closed interval. + + Returns + ------- + G : networkx graph + + Examples + -------- + >>> intervals = [(-2, 3), [1, 4], (2, 3), (4, 6)] + >>> G = nx.interval_graph(intervals) + >>> sorted(G.edges) + [((-2, 3), (1, 4)), ((-2, 3), (2, 3)), ((1, 4), (2, 3)), ((1, 4), (4, 6))] + + Raises + ------ + :exc:`TypeError` + if `intervals` contains None or an element which is not + collections.abc.Sequence or not a length of 2. + :exc:`ValueError` + if `intervals` contains an interval such that min1 > max1 + where min1,max1 = interval + """ + intervals = list(intervals) + for interval in intervals: + if not (isinstance(interval, Sequence) and len(interval) == 2): + raise TypeError( + "Each interval must have length 2, and be a " + "collections.abc.Sequence such as tuple or list." + ) + if interval[0] > interval[1]: + raise ValueError(f"Interval must have lower value first. Got {interval}") + + graph = nx.Graph() + + tupled_intervals = [tuple(interval) for interval in intervals] + graph.add_nodes_from(tupled_intervals) + + while tupled_intervals: + min1, max1 = interval1 = tupled_intervals.pop() + for interval2 in tupled_intervals: + min2, max2 = interval2 + if max1 >= min2 and max2 >= min1: + graph.add_edge(interval1, interval2) + return graph diff --git a/janus/lib/python3.10/site-packages/networkx/generators/joint_degree_seq.py b/janus/lib/python3.10/site-packages/networkx/generators/joint_degree_seq.py new file mode 100644 index 0000000000000000000000000000000000000000..c426df944ad27aef4584371838a6ddb280b90dca --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/joint_degree_seq.py @@ -0,0 +1,664 @@ +"""Generate graphs with a given joint degree and directed joint degree""" + +import networkx as nx +from networkx.utils import py_random_state + +__all__ = [ + "is_valid_joint_degree", + "is_valid_directed_joint_degree", + "joint_degree_graph", + "directed_joint_degree_graph", +] + + +@nx._dispatchable(graphs=None) +def is_valid_joint_degree(joint_degrees): + """Checks whether the given joint degree dictionary is realizable. + + A *joint degree dictionary* is a dictionary of dictionaries, in + which entry ``joint_degrees[k][l]`` is an integer representing the + number of edges joining nodes of degree *k* with nodes of degree + *l*. Such a dictionary is realizable as a simple graph if and only + if the following conditions are satisfied. + + - each entry must be an integer, + - the total number of nodes of degree *k*, computed by + ``sum(joint_degrees[k].values()) / k``, must be an integer, + - the total number of edges joining nodes of degree *k* with + nodes of degree *l* cannot exceed the total number of possible edges, + - each diagonal entry ``joint_degrees[k][k]`` must be even (this is + a convention assumed by the :func:`joint_degree_graph` function). + + + Parameters + ---------- + joint_degrees : dictionary of dictionary of integers + A joint degree dictionary in which entry ``joint_degrees[k][l]`` + is the number of edges joining nodes of degree *k* with nodes of + degree *l*. + + Returns + ------- + bool + Whether the given joint degree dictionary is realizable as a + simple graph. + + References + ---------- + .. [1] M. Gjoka, M. Kurant, A. Markopoulou, "2.5K Graphs: from Sampling + to Generation", IEEE Infocom, 2013. + .. [2] I. Stanton, A. Pinar, "Constructing and sampling graphs with a + prescribed joint degree distribution", Journal of Experimental + Algorithmics, 2012. + """ + + degree_count = {} + for k in joint_degrees: + if k > 0: + k_size = sum(joint_degrees[k].values()) / k + if not k_size.is_integer(): + return False + degree_count[k] = k_size + + for k in joint_degrees: + for l in joint_degrees[k]: + if not float(joint_degrees[k][l]).is_integer(): + return False + + if (k != l) and (joint_degrees[k][l] > degree_count[k] * degree_count[l]): + return False + elif k == l: + if joint_degrees[k][k] > degree_count[k] * (degree_count[k] - 1): + return False + if joint_degrees[k][k] % 2 != 0: + return False + + # if all above conditions have been satisfied then the input + # joint degree is realizable as a simple graph. + return True + + +def _neighbor_switch(G, w, unsat, h_node_residual, avoid_node_id=None): + """Releases one free stub for ``w``, while preserving joint degree in G. + + Parameters + ---------- + G : NetworkX graph + Graph in which the neighbor switch will take place. + w : integer + Node id for which we will execute this neighbor switch. + unsat : set of integers + Set of unsaturated node ids that have the same degree as w. + h_node_residual: dictionary of integers + Keeps track of the remaining stubs for a given node. + avoid_node_id: integer + Node id to avoid when selecting w_prime. + + Notes + ----- + First, it selects *w_prime*, an unsaturated node that has the same degree + as ``w``. Second, it selects *switch_node*, a neighbor node of ``w`` that + is not connected to *w_prime*. Then it executes an edge swap i.e. removes + (``w``,*switch_node*) and adds (*w_prime*,*switch_node*). Gjoka et. al. [1] + prove that such an edge swap is always possible. + + References + ---------- + .. [1] M. Gjoka, B. Tillman, A. Markopoulou, "Construction of Simple + Graphs with a Target Joint Degree Matrix and Beyond", IEEE Infocom, '15 + """ + + if (avoid_node_id is None) or (h_node_residual[avoid_node_id] > 1): + # select unsaturated node w_prime that has the same degree as w + w_prime = next(iter(unsat)) + else: + # assume that the node pair (v,w) has been selected for connection. if + # - neighbor_switch is called for node w, + # - nodes v and w have the same degree, + # - node v=avoid_node_id has only one stub left, + # then prevent v=avoid_node_id from being selected as w_prime. + + iter_var = iter(unsat) + while True: + w_prime = next(iter_var) + if w_prime != avoid_node_id: + break + + # select switch_node, a neighbor of w, that is not connected to w_prime + w_prime_neighbs = G[w_prime] # slightly faster declaring this variable + for v in G[w]: + if (v not in w_prime_neighbs) and (v != w_prime): + switch_node = v + break + + # remove edge (w,switch_node), add edge (w_prime,switch_node) and update + # data structures + G.remove_edge(w, switch_node) + G.add_edge(w_prime, switch_node) + h_node_residual[w] += 1 + h_node_residual[w_prime] -= 1 + if h_node_residual[w_prime] == 0: + unsat.remove(w_prime) + + +@py_random_state(1) +@nx._dispatchable(graphs=None, returns_graph=True) +def joint_degree_graph(joint_degrees, seed=None): + """Generates a random simple graph with the given joint degree dictionary. + + Parameters + ---------- + joint_degrees : dictionary of dictionary of integers + A joint degree dictionary in which entry ``joint_degrees[k][l]`` is the + number of edges joining nodes of degree *k* with nodes of degree *l*. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + G : Graph + A graph with the specified joint degree dictionary. + + Raises + ------ + NetworkXError + If *joint_degrees* dictionary is not realizable. + + Notes + ----- + In each iteration of the "while loop" the algorithm picks two disconnected + nodes *v* and *w*, of degree *k* and *l* correspondingly, for which + ``joint_degrees[k][l]`` has not reached its target yet. It then adds + edge (*v*, *w*) and increases the number of edges in graph G by one. + + The intelligence of the algorithm lies in the fact that it is always + possible to add an edge between such disconnected nodes *v* and *w*, + even if one or both nodes do not have free stubs. That is made possible by + executing a "neighbor switch", an edge rewiring move that releases + a free stub while keeping the joint degree of G the same. + + The algorithm continues for E (number of edges) iterations of + the "while loop", at the which point all entries of the given + ``joint_degrees[k][l]`` have reached their target values and the + construction is complete. + + References + ---------- + .. [1] M. Gjoka, B. Tillman, A. Markopoulou, "Construction of Simple + Graphs with a Target Joint Degree Matrix and Beyond", IEEE Infocom, '15 + + Examples + -------- + >>> joint_degrees = { + ... 1: {4: 1}, + ... 2: {2: 2, 3: 2, 4: 2}, + ... 3: {2: 2, 4: 1}, + ... 4: {1: 1, 2: 2, 3: 1}, + ... } + >>> G = nx.joint_degree_graph(joint_degrees) + >>> + """ + + if not is_valid_joint_degree(joint_degrees): + msg = "Input joint degree dict not realizable as a simple graph" + raise nx.NetworkXError(msg) + + # compute degree count from joint_degrees + degree_count = {k: sum(l.values()) // k for k, l in joint_degrees.items() if k > 0} + + # start with empty N-node graph + N = sum(degree_count.values()) + G = nx.empty_graph(N) + + # for a given degree group, keep the list of all node ids + h_degree_nodelist = {} + + # for a given node, keep track of the remaining stubs + h_node_residual = {} + + # populate h_degree_nodelist and h_node_residual + nodeid = 0 + for degree, num_nodes in degree_count.items(): + h_degree_nodelist[degree] = range(nodeid, nodeid + num_nodes) + for v in h_degree_nodelist[degree]: + h_node_residual[v] = degree + nodeid += int(num_nodes) + + # iterate over every degree pair (k,l) and add the number of edges given + # for each pair + for k in joint_degrees: + for l in joint_degrees[k]: + # n_edges_add is the number of edges to add for the + # degree pair (k,l) + n_edges_add = joint_degrees[k][l] + + if (n_edges_add > 0) and (k >= l): + # number of nodes with degree k and l + k_size = degree_count[k] + l_size = degree_count[l] + + # k_nodes and l_nodes consist of all nodes of degree k and l + k_nodes = h_degree_nodelist[k] + l_nodes = h_degree_nodelist[l] + + # k_unsat and l_unsat consist of nodes of degree k and l that + # are unsaturated (nodes that have at least 1 available stub) + k_unsat = {v for v in k_nodes if h_node_residual[v] > 0} + + if k != l: + l_unsat = {w for w in l_nodes if h_node_residual[w] > 0} + else: + l_unsat = k_unsat + n_edges_add = joint_degrees[k][l] // 2 + + while n_edges_add > 0: + # randomly pick nodes v and w that have degrees k and l + v = k_nodes[seed.randrange(k_size)] + w = l_nodes[seed.randrange(l_size)] + + # if nodes v and w are disconnected then attempt to connect + if not G.has_edge(v, w) and (v != w): + # if node v has no free stubs then do neighbor switch + if h_node_residual[v] == 0: + _neighbor_switch(G, v, k_unsat, h_node_residual) + + # if node w has no free stubs then do neighbor switch + if h_node_residual[w] == 0: + if k != l: + _neighbor_switch(G, w, l_unsat, h_node_residual) + else: + _neighbor_switch( + G, w, l_unsat, h_node_residual, avoid_node_id=v + ) + + # add edge (v, w) and update data structures + G.add_edge(v, w) + h_node_residual[v] -= 1 + h_node_residual[w] -= 1 + n_edges_add -= 1 + + if h_node_residual[v] == 0: + k_unsat.discard(v) + if h_node_residual[w] == 0: + l_unsat.discard(w) + return G + + +@nx._dispatchable(graphs=None) +def is_valid_directed_joint_degree(in_degrees, out_degrees, nkk): + """Checks whether the given directed joint degree input is realizable + + Parameters + ---------- + in_degrees : list of integers + in degree sequence contains the in degrees of nodes. + out_degrees : list of integers + out degree sequence contains the out degrees of nodes. + nkk : dictionary of dictionary of integers + directed joint degree dictionary. for nodes of out degree k (first + level of dict) and nodes of in degree l (second level of dict) + describes the number of edges. + + Returns + ------- + boolean + returns true if given input is realizable, else returns false. + + Notes + ----- + Here is the list of conditions that the inputs (in/out degree sequences, + nkk) need to satisfy for simple directed graph realizability: + + - Condition 0: in_degrees and out_degrees have the same length + - Condition 1: nkk[k][l] is integer for all k,l + - Condition 2: sum(nkk[k])/k = number of nodes with partition id k, is an + integer and matching degree sequence + - Condition 3: number of edges and non-chords between k and l cannot exceed + maximum possible number of edges + + + References + ---------- + [1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka, + "Construction of Directed 2K Graphs". In Proc. of KDD 2017. + """ + V = {} # number of nodes with in/out degree. + forbidden = {} + if len(in_degrees) != len(out_degrees): + return False + + for idx in range(len(in_degrees)): + i = in_degrees[idx] + o = out_degrees[idx] + V[(i, 0)] = V.get((i, 0), 0) + 1 + V[(o, 1)] = V.get((o, 1), 0) + 1 + + forbidden[(o, i)] = forbidden.get((o, i), 0) + 1 + + S = {} # number of edges going from in/out degree nodes. + for k in nkk: + for l in nkk[k]: + val = nkk[k][l] + if not float(val).is_integer(): # condition 1 + return False + + if val > 0: + S[(k, 1)] = S.get((k, 1), 0) + val + S[(l, 0)] = S.get((l, 0), 0) + val + # condition 3 + if val + forbidden.get((k, l), 0) > V[(k, 1)] * V[(l, 0)]: + return False + + return all(S[s] / s[0] == V[s] for s in S) + + +def _directed_neighbor_switch( + G, w, unsat, h_node_residual_out, chords, h_partition_in, partition +): + """Releases one free stub for node w, while preserving joint degree in G. + + Parameters + ---------- + G : networkx directed graph + graph within which the edge swap will take place. + w : integer + node id for which we need to perform a neighbor switch. + unsat: set of integers + set of node ids that have the same degree as w and are unsaturated. + h_node_residual_out: dict of integers + for a given node, keeps track of the remaining stubs to be added. + chords: set of tuples + keeps track of available positions to add edges. + h_partition_in: dict of integers + for a given node, keeps track of its partition id (in degree). + partition: integer + partition id to check if chords have to be updated. + + Notes + ----- + First, it selects node w_prime that (1) has the same degree as w and + (2) is unsaturated. Then, it selects node v, a neighbor of w, that is + not connected to w_prime and does an edge swap i.e. removes (w,v) and + adds (w_prime,v). If neighbor switch is not possible for w using + w_prime and v, then return w_prime; in [1] it's proven that + such unsaturated nodes can be used. + + References + ---------- + [1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka, + "Construction of Directed 2K Graphs". In Proc. of KDD 2017. + """ + w_prime = unsat.pop() + unsat.add(w_prime) + # select node t, a neighbor of w, that is not connected to w_prime + w_neighbs = list(G.successors(w)) + # slightly faster declaring this variable + w_prime_neighbs = list(G.successors(w_prime)) + + for v in w_neighbs: + if (v not in w_prime_neighbs) and w_prime != v: + # removes (w,v), add (w_prime,v) and update data structures + G.remove_edge(w, v) + G.add_edge(w_prime, v) + + if h_partition_in[v] == partition: + chords.add((w, v)) + chords.discard((w_prime, v)) + + h_node_residual_out[w] += 1 + h_node_residual_out[w_prime] -= 1 + if h_node_residual_out[w_prime] == 0: + unsat.remove(w_prime) + return None + + # If neighbor switch didn't work, use unsaturated node + return w_prime + + +def _directed_neighbor_switch_rev( + G, w, unsat, h_node_residual_in, chords, h_partition_out, partition +): + """The reverse of directed_neighbor_switch. + + Parameters + ---------- + G : networkx directed graph + graph within which the edge swap will take place. + w : integer + node id for which we need to perform a neighbor switch. + unsat: set of integers + set of node ids that have the same degree as w and are unsaturated. + h_node_residual_in: dict of integers + for a given node, keeps track of the remaining stubs to be added. + chords: set of tuples + keeps track of available positions to add edges. + h_partition_out: dict of integers + for a given node, keeps track of its partition id (out degree). + partition: integer + partition id to check if chords have to be updated. + + Notes + ----- + Same operation as directed_neighbor_switch except it handles this operation + for incoming edges instead of outgoing. + """ + w_prime = unsat.pop() + unsat.add(w_prime) + # slightly faster declaring these as variables. + w_neighbs = list(G.predecessors(w)) + w_prime_neighbs = list(G.predecessors(w_prime)) + # select node v, a neighbor of w, that is not connected to w_prime. + for v in w_neighbs: + if (v not in w_prime_neighbs) and w_prime != v: + # removes (v,w), add (v,w_prime) and update data structures. + G.remove_edge(v, w) + G.add_edge(v, w_prime) + if h_partition_out[v] == partition: + chords.add((v, w)) + chords.discard((v, w_prime)) + + h_node_residual_in[w] += 1 + h_node_residual_in[w_prime] -= 1 + if h_node_residual_in[w_prime] == 0: + unsat.remove(w_prime) + return None + + # If neighbor switch didn't work, use the unsaturated node. + return w_prime + + +@py_random_state(3) +@nx._dispatchable(graphs=None, returns_graph=True) +def directed_joint_degree_graph(in_degrees, out_degrees, nkk, seed=None): + """Generates a random simple directed graph with the joint degree. + + Parameters + ---------- + degree_seq : list of tuples (of size 3) + degree sequence contains tuples of nodes with node id, in degree and + out degree. + nkk : dictionary of dictionary of integers + directed joint degree dictionary, for nodes of out degree k (first + level of dict) and nodes of in degree l (second level of dict) + describes the number of edges. + seed : hashable object, optional + Seed for random number generator. + + Returns + ------- + G : Graph + A directed graph with the specified inputs. + + Raises + ------ + NetworkXError + If degree_seq and nkk are not realizable as a simple directed graph. + + + Notes + ----- + Similarly to the undirected version: + In each iteration of the "while loop" the algorithm picks two disconnected + nodes v and w, of degree k and l correspondingly, for which nkk[k][l] has + not reached its target yet i.e. (for given k,l): n_edges_add < nkk[k][l]. + It then adds edge (v,w) and always increases the number of edges in graph G + by one. + + The intelligence of the algorithm lies in the fact that it is always + possible to add an edge between disconnected nodes v and w, for which + nkk[degree(v)][degree(w)] has not reached its target, even if one or both + nodes do not have free stubs. If either node v or w does not have a free + stub, we perform a "neighbor switch", an edge rewiring move that releases a + free stub while keeping nkk the same. + + The difference for the directed version lies in the fact that neighbor + switches might not be able to rewire, but in these cases unsaturated nodes + can be reassigned to use instead, see [1] for detailed description and + proofs. + + The algorithm continues for E (number of edges in the graph) iterations of + the "while loop", at which point all entries of the given nkk[k][l] have + reached their target values and the construction is complete. + + References + ---------- + [1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka, + "Construction of Directed 2K Graphs". In Proc. of KDD 2017. + + Examples + -------- + >>> in_degrees = [0, 1, 1, 2] + >>> out_degrees = [1, 1, 1, 1] + >>> nkk = {1: {1: 2, 2: 2}} + >>> G = nx.directed_joint_degree_graph(in_degrees, out_degrees, nkk) + >>> + """ + if not is_valid_directed_joint_degree(in_degrees, out_degrees, nkk): + msg = "Input is not realizable as a simple graph" + raise nx.NetworkXError(msg) + + # start with an empty directed graph. + G = nx.DiGraph() + + # for a given group, keep the list of all node ids. + h_degree_nodelist_in = {} + h_degree_nodelist_out = {} + # for a given group, keep the list of all unsaturated node ids. + h_degree_nodelist_in_unsat = {} + h_degree_nodelist_out_unsat = {} + # for a given node, keep track of the remaining stubs to be added. + h_node_residual_out = {} + h_node_residual_in = {} + # for a given node, keep track of the partition id. + h_partition_out = {} + h_partition_in = {} + # keep track of non-chords between pairs of partition ids. + non_chords = {} + + # populate data structures + for idx, i in enumerate(in_degrees): + idx = int(idx) + if i > 0: + h_degree_nodelist_in.setdefault(i, []) + h_degree_nodelist_in_unsat.setdefault(i, set()) + h_degree_nodelist_in[i].append(idx) + h_degree_nodelist_in_unsat[i].add(idx) + h_node_residual_in[idx] = i + h_partition_in[idx] = i + + for idx, o in enumerate(out_degrees): + o = out_degrees[idx] + non_chords[(o, in_degrees[idx])] = non_chords.get((o, in_degrees[idx]), 0) + 1 + idx = int(idx) + if o > 0: + h_degree_nodelist_out.setdefault(o, []) + h_degree_nodelist_out_unsat.setdefault(o, set()) + h_degree_nodelist_out[o].append(idx) + h_degree_nodelist_out_unsat[o].add(idx) + h_node_residual_out[idx] = o + h_partition_out[idx] = o + + G.add_node(idx) + + nk_in = {} + nk_out = {} + for p in h_degree_nodelist_in: + nk_in[p] = len(h_degree_nodelist_in[p]) + for p in h_degree_nodelist_out: + nk_out[p] = len(h_degree_nodelist_out[p]) + + # iterate over every degree pair (k,l) and add the number of edges given + # for each pair. + for k in nkk: + for l in nkk[k]: + n_edges_add = nkk[k][l] + + if n_edges_add > 0: + # chords contains a random set of potential edges. + chords = set() + + k_len = nk_out[k] + l_len = nk_in[l] + chords_sample = seed.sample( + range(k_len * l_len), n_edges_add + non_chords.get((k, l), 0) + ) + + num = 0 + while len(chords) < n_edges_add: + i = h_degree_nodelist_out[k][chords_sample[num] % k_len] + j = h_degree_nodelist_in[l][chords_sample[num] // k_len] + num += 1 + if i != j: + chords.add((i, j)) + + # k_unsat and l_unsat consist of nodes of in/out degree k and l + # that are unsaturated i.e. those nodes that have at least one + # available stub + k_unsat = h_degree_nodelist_out_unsat[k] + l_unsat = h_degree_nodelist_in_unsat[l] + + while n_edges_add > 0: + v, w = chords.pop() + chords.add((v, w)) + + # if node v has no free stubs then do neighbor switch. + if h_node_residual_out[v] == 0: + _v = _directed_neighbor_switch( + G, + v, + k_unsat, + h_node_residual_out, + chords, + h_partition_in, + l, + ) + if _v is not None: + v = _v + + # if node w has no free stubs then do neighbor switch. + if h_node_residual_in[w] == 0: + _w = _directed_neighbor_switch_rev( + G, + w, + l_unsat, + h_node_residual_in, + chords, + h_partition_out, + k, + ) + if _w is not None: + w = _w + + # add edge (v,w) and update data structures. + G.add_edge(v, w) + h_node_residual_out[v] -= 1 + h_node_residual_in[w] -= 1 + n_edges_add -= 1 + chords.discard((v, w)) + + if h_node_residual_out[v] == 0: + k_unsat.discard(v) + if h_node_residual_in[w] == 0: + l_unsat.discard(w) + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/line.py b/janus/lib/python3.10/site-packages/networkx/generators/line.py new file mode 100644 index 0000000000000000000000000000000000000000..87d251827f5118cd97d7e575a8553f44b7e041c3 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/line.py @@ -0,0 +1,500 @@ +"""Functions for generating line graphs.""" + +from collections import defaultdict +from functools import partial +from itertools import combinations + +import networkx as nx +from networkx.utils import arbitrary_element +from networkx.utils.decorators import not_implemented_for + +__all__ = ["line_graph", "inverse_line_graph"] + + +@nx._dispatchable(returns_graph=True) +def line_graph(G, create_using=None): + r"""Returns the line graph of the graph or digraph `G`. + + The line graph of a graph `G` has a node for each edge in `G` and an + edge joining those nodes if the two edges in `G` share a common node. For + directed graphs, nodes are adjacent exactly when the edges they represent + form a directed path of length two. + + The nodes of the line graph are 2-tuples of nodes in the original graph (or + 3-tuples for multigraphs, with the key of the edge as the third element). + + For information about self-loops and more discussion, see the **Notes** + section below. + + Parameters + ---------- + G : graph + A NetworkX Graph, DiGraph, MultiGraph, or MultiDigraph. + create_using : NetworkX graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + + Returns + ------- + L : graph + The line graph of G. + + Examples + -------- + >>> G = nx.star_graph(3) + >>> L = nx.line_graph(G) + >>> print(sorted(map(sorted, L.edges()))) # makes a 3-clique, K3 + [[(0, 1), (0, 2)], [(0, 1), (0, 3)], [(0, 2), (0, 3)]] + + Edge attributes from `G` are not copied over as node attributes in `L`, but + attributes can be copied manually: + + >>> G = nx.path_graph(4) + >>> G.add_edges_from((u, v, {"tot": u + v}) for u, v in G.edges) + >>> G.edges(data=True) + EdgeDataView([(0, 1, {'tot': 1}), (1, 2, {'tot': 3}), (2, 3, {'tot': 5})]) + >>> H = nx.line_graph(G) + >>> H.add_nodes_from((node, G.edges[node]) for node in H) + >>> H.nodes(data=True) + NodeDataView({(0, 1): {'tot': 1}, (2, 3): {'tot': 5}, (1, 2): {'tot': 3}}) + + Notes + ----- + Graph, node, and edge data are not propagated to the new graph. For + undirected graphs, the nodes in G must be sortable, otherwise the + constructed line graph may not be correct. + + *Self-loops in undirected graphs* + + For an undirected graph `G` without multiple edges, each edge can be + written as a set `\{u, v\}`. Its line graph `L` has the edges of `G` as + its nodes. If `x` and `y` are two nodes in `L`, then `\{x, y\}` is an edge + in `L` if and only if the intersection of `x` and `y` is nonempty. Thus, + the set of all edges is determined by the set of all pairwise intersections + of edges in `G`. + + Trivially, every edge in G would have a nonzero intersection with itself, + and so every node in `L` should have a self-loop. This is not so + interesting, and the original context of line graphs was with simple + graphs, which had no self-loops or multiple edges. The line graph was also + meant to be a simple graph and thus, self-loops in `L` are not part of the + standard definition of a line graph. In a pairwise intersection matrix, + this is analogous to excluding the diagonal entries from the line graph + definition. + + Self-loops and multiple edges in `G` add nodes to `L` in a natural way, and + do not require any fundamental changes to the definition. It might be + argued that the self-loops we excluded before should now be included. + However, the self-loops are still "trivial" in some sense and thus, are + usually excluded. + + *Self-loops in directed graphs* + + For a directed graph `G` without multiple edges, each edge can be written + as a tuple `(u, v)`. Its line graph `L` has the edges of `G` as its + nodes. If `x` and `y` are two nodes in `L`, then `(x, y)` is an edge in `L` + if and only if the tail of `x` matches the head of `y`, for example, if `x + = (a, b)` and `y = (b, c)` for some vertices `a`, `b`, and `c` in `G`. + + Due to the directed nature of the edges, it is no longer the case that + every edge in `G` should have a self-loop in `L`. Now, the only time + self-loops arise is if a node in `G` itself has a self-loop. So such + self-loops are no longer "trivial" but instead, represent essential + features of the topology of `G`. For this reason, the historical + development of line digraphs is such that self-loops are included. When the + graph `G` has multiple edges, once again only superficial changes are + required to the definition. + + References + ---------- + * Harary, Frank, and Norman, Robert Z., "Some properties of line digraphs", + Rend. Circ. Mat. Palermo, II. Ser. 9 (1960), 161--168. + * Hemminger, R. L.; Beineke, L. W. (1978), "Line graphs and line digraphs", + in Beineke, L. W.; Wilson, R. J., Selected Topics in Graph Theory, + Academic Press Inc., pp. 271--305. + + """ + if G.is_directed(): + L = _lg_directed(G, create_using=create_using) + else: + L = _lg_undirected(G, selfloops=False, create_using=create_using) + return L + + +def _lg_directed(G, create_using=None): + """Returns the line graph L of the (multi)digraph G. + + Edges in G appear as nodes in L, represented as tuples of the form (u,v) + or (u,v,key) if G is a multidigraph. A node in L corresponding to the edge + (u,v) is connected to every node corresponding to an edge (v,w). + + Parameters + ---------- + G : digraph + A directed graph or directed multigraph. + create_using : NetworkX graph constructor, optional + Graph type to create. If graph instance, then cleared before populated. + Default is to use the same graph class as `G`. + + """ + L = nx.empty_graph(0, create_using, default=G.__class__) + + # Create a graph specific edge function. + get_edges = partial(G.edges, keys=True) if G.is_multigraph() else G.edges + + for from_node in get_edges(): + # from_node is: (u,v) or (u,v,key) + L.add_node(from_node) + for to_node in get_edges(from_node[1]): + L.add_edge(from_node, to_node) + + return L + + +def _lg_undirected(G, selfloops=False, create_using=None): + """Returns the line graph L of the (multi)graph G. + + Edges in G appear as nodes in L, represented as sorted tuples of the form + (u,v), or (u,v,key) if G is a multigraph. A node in L corresponding to + the edge {u,v} is connected to every node corresponding to an edge that + involves u or v. + + Parameters + ---------- + G : graph + An undirected graph or multigraph. + selfloops : bool + If `True`, then self-loops are included in the line graph. If `False`, + they are excluded. + create_using : NetworkX graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + + Notes + ----- + The standard algorithm for line graphs of undirected graphs does not + produce self-loops. + + """ + L = nx.empty_graph(0, create_using, default=G.__class__) + + # Graph specific functions for edges. + get_edges = partial(G.edges, keys=True) if G.is_multigraph() else G.edges + + # Determine if we include self-loops or not. + shift = 0 if selfloops else 1 + + # Introduce numbering of nodes + node_index = {n: i for i, n in enumerate(G)} + + # Lift canonical representation of nodes to edges in line graph + edge_key_function = lambda edge: (node_index[edge[0]], node_index[edge[1]]) + + edges = set() + for u in G: + # Label nodes as a sorted tuple of nodes in original graph. + # Decide on representation of {u, v} as (u, v) or (v, u) depending on node_index. + # -> This ensures a canonical representation and avoids comparing values of different types. + nodes = [tuple(sorted(x[:2], key=node_index.get)) + x[2:] for x in get_edges(u)] + + if len(nodes) == 1: + # Then the edge will be an isolated node in L. + L.add_node(nodes[0]) + + # Add a clique of `nodes` to graph. To prevent double adding edges, + # especially important for multigraphs, we store the edges in + # canonical form in a set. + for i, a in enumerate(nodes): + edges.update( + [ + tuple(sorted((a, b), key=edge_key_function)) + for b in nodes[i + shift :] + ] + ) + + L.add_edges_from(edges) + return L + + +@not_implemented_for("directed") +@not_implemented_for("multigraph") +@nx._dispatchable(returns_graph=True) +def inverse_line_graph(G): + """Returns the inverse line graph of graph G. + + If H is a graph, and G is the line graph of H, such that G = L(H). + Then H is the inverse line graph of G. + + Not all graphs are line graphs and these do not have an inverse line graph. + In these cases this function raises a NetworkXError. + + Parameters + ---------- + G : graph + A NetworkX Graph + + Returns + ------- + H : graph + The inverse line graph of G. + + Raises + ------ + NetworkXNotImplemented + If G is directed or a multigraph + + NetworkXError + If G is not a line graph + + Notes + ----- + This is an implementation of the Roussopoulos algorithm[1]_. + + If G consists of multiple components, then the algorithm doesn't work. + You should invert every component separately: + + >>> K5 = nx.complete_graph(5) + >>> P4 = nx.Graph([("a", "b"), ("b", "c"), ("c", "d")]) + >>> G = nx.union(K5, P4) + >>> root_graphs = [] + >>> for comp in nx.connected_components(G): + ... root_graphs.append(nx.inverse_line_graph(G.subgraph(comp))) + >>> len(root_graphs) + 2 + + References + ---------- + .. [1] Roussopoulos, N.D. , "A max {m, n} algorithm for determining the graph H from + its line graph G", Information Processing Letters 2, (1973), 108--112, ISSN 0020-0190, + `DOI link `_ + + """ + if G.number_of_nodes() == 0: + return nx.empty_graph(1) + elif G.number_of_nodes() == 1: + v = arbitrary_element(G) + a = (v, 0) + b = (v, 1) + H = nx.Graph([(a, b)]) + return H + elif G.number_of_nodes() > 1 and G.number_of_edges() == 0: + msg = ( + "inverse_line_graph() doesn't work on an edgeless graph. " + "Please use this function on each component separately." + ) + raise nx.NetworkXError(msg) + + if nx.number_of_selfloops(G) != 0: + msg = ( + "A line graph as generated by NetworkX has no selfloops, so G has no " + "inverse line graph. Please remove the selfloops from G and try again." + ) + raise nx.NetworkXError(msg) + + starting_cell = _select_starting_cell(G) + P = _find_partition(G, starting_cell) + # count how many times each vertex appears in the partition set + P_count = {u: 0 for u in G.nodes} + for p in P: + for u in p: + P_count[u] += 1 + + if max(P_count.values()) > 2: + msg = "G is not a line graph (vertex found in more than two partition cells)" + raise nx.NetworkXError(msg) + W = tuple((u,) for u in P_count if P_count[u] == 1) + H = nx.Graph() + H.add_nodes_from(P) + H.add_nodes_from(W) + for a, b in combinations(H.nodes, 2): + if any(a_bit in b for a_bit in a): + H.add_edge(a, b) + return H + + +def _triangles(G, e): + """Return list of all triangles containing edge e""" + u, v = e + if u not in G: + raise nx.NetworkXError(f"Vertex {u} not in graph") + if v not in G[u]: + raise nx.NetworkXError(f"Edge ({u}, {v}) not in graph") + triangle_list = [] + for x in G[u]: + if x in G[v]: + triangle_list.append((u, v, x)) + return triangle_list + + +def _odd_triangle(G, T): + """Test whether T is an odd triangle in G + + Parameters + ---------- + G : NetworkX Graph + T : 3-tuple of vertices forming triangle in G + + Returns + ------- + True is T is an odd triangle + False otherwise + + Raises + ------ + NetworkXError + T is not a triangle in G + + Notes + ----- + An odd triangle is one in which there exists another vertex in G which is + adjacent to either exactly one or exactly all three of the vertices in the + triangle. + + """ + for u in T: + if u not in G.nodes(): + raise nx.NetworkXError(f"Vertex {u} not in graph") + for e in list(combinations(T, 2)): + if e[0] not in G[e[1]]: + raise nx.NetworkXError(f"Edge ({e[0]}, {e[1]}) not in graph") + + T_nbrs = defaultdict(int) + for t in T: + for v in G[t]: + if v not in T: + T_nbrs[v] += 1 + return any(T_nbrs[v] in [1, 3] for v in T_nbrs) + + +def _find_partition(G, starting_cell): + """Find a partition of the vertices of G into cells of complete graphs + + Parameters + ---------- + G : NetworkX Graph + starting_cell : tuple of vertices in G which form a cell + + Returns + ------- + List of tuples of vertices of G + + Raises + ------ + NetworkXError + If a cell is not a complete subgraph then G is not a line graph + """ + G_partition = G.copy() + P = [starting_cell] # partition set + G_partition.remove_edges_from(list(combinations(starting_cell, 2))) + # keep list of partitioned nodes which might have an edge in G_partition + partitioned_vertices = list(starting_cell) + while G_partition.number_of_edges() > 0: + # there are still edges left and so more cells to be made + u = partitioned_vertices.pop() + deg_u = len(G_partition[u]) + if deg_u != 0: + # if u still has edges then we need to find its other cell + # this other cell must be a complete subgraph or else G is + # not a line graph + new_cell = [u] + list(G_partition[u]) + for u in new_cell: + for v in new_cell: + if (u != v) and (v not in G_partition[u]): + msg = ( + "G is not a line graph " + "(partition cell not a complete subgraph)" + ) + raise nx.NetworkXError(msg) + P.append(tuple(new_cell)) + G_partition.remove_edges_from(list(combinations(new_cell, 2))) + partitioned_vertices += new_cell + return P + + +def _select_starting_cell(G, starting_edge=None): + """Select a cell to initiate _find_partition + + Parameters + ---------- + G : NetworkX Graph + starting_edge: an edge to build the starting cell from + + Returns + ------- + Tuple of vertices in G + + Raises + ------ + NetworkXError + If it is determined that G is not a line graph + + Notes + ----- + If starting edge not specified then pick an arbitrary edge - doesn't + matter which. However, this function may call itself requiring a + specific starting edge. Note that the r, s notation for counting + triangles is the same as in the Roussopoulos paper cited above. + """ + if starting_edge is None: + e = arbitrary_element(G.edges()) + else: + e = starting_edge + if e[0] not in G.nodes(): + raise nx.NetworkXError(f"Vertex {e[0]} not in graph") + if e[1] not in G[e[0]]: + msg = f"starting_edge ({e[0]}, {e[1]}) is not in the Graph" + raise nx.NetworkXError(msg) + e_triangles = _triangles(G, e) + r = len(e_triangles) + if r == 0: + # there are no triangles containing e, so the starting cell is just e + starting_cell = e + elif r == 1: + # there is exactly one triangle, T, containing e. If other 2 edges + # of T belong only to this triangle then T is starting cell + T = e_triangles[0] + a, b, c = T + # ab was original edge so check the other 2 edges + ac_edges = len(_triangles(G, (a, c))) + bc_edges = len(_triangles(G, (b, c))) + if ac_edges == 1: + if bc_edges == 1: + starting_cell = T + else: + return _select_starting_cell(G, starting_edge=(b, c)) + else: + return _select_starting_cell(G, starting_edge=(a, c)) + else: + # r >= 2 so we need to count the number of odd triangles, s + s = 0 + odd_triangles = [] + for T in e_triangles: + if _odd_triangle(G, T): + s += 1 + odd_triangles.append(T) + if r == 2 and s == 0: + # in this case either triangle works, so just use T + starting_cell = T + elif r - 1 <= s <= r: + # check if odd triangles containing e form complete subgraph + triangle_nodes = set() + for T in odd_triangles: + for x in T: + triangle_nodes.add(x) + + for u in triangle_nodes: + for v in triangle_nodes: + if u != v and (v not in G[u]): + msg = ( + "G is not a line graph (odd triangles " + "do not form complete subgraph)" + ) + raise nx.NetworkXError(msg) + # otherwise then we can use this as the starting cell + starting_cell = tuple(triangle_nodes) + + else: + msg = ( + "G is not a line graph (incorrect number of " + "odd triangles around starting edge)" + ) + raise nx.NetworkXError(msg) + return starting_cell diff --git a/janus/lib/python3.10/site-packages/networkx/generators/random_graphs.py b/janus/lib/python3.10/site-packages/networkx/generators/random_graphs.py new file mode 100644 index 0000000000000000000000000000000000000000..90ae0d973ac42550280bf74db0d2fef3117d58da --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/random_graphs.py @@ -0,0 +1,1400 @@ +""" +Generators for random graphs. + +""" + +import itertools +import math +from collections import defaultdict + +import networkx as nx +from networkx.utils import py_random_state + +from ..utils.misc import check_create_using +from .classic import complete_graph, empty_graph, path_graph, star_graph +from .degree_seq import degree_sequence_tree + +__all__ = [ + "fast_gnp_random_graph", + "gnp_random_graph", + "dense_gnm_random_graph", + "gnm_random_graph", + "erdos_renyi_graph", + "binomial_graph", + "newman_watts_strogatz_graph", + "watts_strogatz_graph", + "connected_watts_strogatz_graph", + "random_regular_graph", + "barabasi_albert_graph", + "dual_barabasi_albert_graph", + "extended_barabasi_albert_graph", + "powerlaw_cluster_graph", + "random_lobster", + "random_shell_graph", + "random_powerlaw_tree", + "random_powerlaw_tree_sequence", + "random_kernel_graph", +] + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def fast_gnp_random_graph(n, p, seed=None, directed=False, *, create_using=None): + """Returns a $G_{n,p}$ random graph, also known as an Erdős-Rényi graph or + a binomial graph. + + Parameters + ---------- + n : int + The number of nodes. + p : float + Probability for edge creation. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + directed : bool, optional (default=False) + If True, this function returns a directed graph. + create_using : Graph constructor, optional (default=nx.Graph or nx.DiGraph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph types are not supported and raise a ``NetworkXError``. + By default NetworkX Graph or DiGraph are used depending on `directed`. + + Notes + ----- + The $G_{n,p}$ graph algorithm chooses each of the $[n (n - 1)] / 2$ + (undirected) or $n (n - 1)$ (directed) possible edges with probability $p$. + + This algorithm [1]_ runs in $O(n + m)$ time, where `m` is the expected number of + edges, which equals $p n (n - 1) / 2$. This should be faster than + :func:`gnp_random_graph` when $p$ is small and the expected number of edges + is small (that is, the graph is sparse). + + See Also + -------- + gnp_random_graph + + References + ---------- + .. [1] Vladimir Batagelj and Ulrik Brandes, + "Efficient generation of large random networks", + Phys. Rev. E, 71, 036113, 2005. + """ + default = nx.DiGraph if directed else nx.Graph + create_using = check_create_using( + create_using, directed=directed, multigraph=False, default=default + ) + if p <= 0 or p >= 1: + return nx.gnp_random_graph( + n, p, seed=seed, directed=directed, create_using=create_using + ) + + G = empty_graph(n, create_using=create_using) + + lp = math.log(1.0 - p) + + if directed: + v = 1 + w = -1 + while v < n: + lr = math.log(1.0 - seed.random()) + w = w + 1 + int(lr / lp) + while w >= v and v < n: + w = w - v + v = v + 1 + if v < n: + G.add_edge(w, v) + + # Nodes in graph are from 0,n-1 (start with v as the second node index). + v = 1 + w = -1 + while v < n: + lr = math.log(1.0 - seed.random()) + w = w + 1 + int(lr / lp) + while w >= v and v < n: + w = w - v + v = v + 1 + if v < n: + G.add_edge(v, w) + return G + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def gnp_random_graph(n, p, seed=None, directed=False, *, create_using=None): + """Returns a $G_{n,p}$ random graph, also known as an Erdős-Rényi graph + or a binomial graph. + + The $G_{n,p}$ model chooses each of the possible edges with probability $p$. + + Parameters + ---------- + n : int + The number of nodes. + p : float + Probability for edge creation. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + directed : bool, optional (default=False) + If True, this function returns a directed graph. + create_using : Graph constructor, optional (default=nx.Graph or nx.DiGraph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph types are not supported and raise a ``NetworkXError``. + By default NetworkX Graph or DiGraph are used depending on `directed`. + + See Also + -------- + fast_gnp_random_graph + + Notes + ----- + This algorithm [2]_ runs in $O(n^2)$ time. For sparse graphs (that is, for + small values of $p$), :func:`fast_gnp_random_graph` is a faster algorithm. + + :func:`binomial_graph` and :func:`erdos_renyi_graph` are + aliases for :func:`gnp_random_graph`. + + >>> nx.binomial_graph is nx.gnp_random_graph + True + >>> nx.erdos_renyi_graph is nx.gnp_random_graph + True + + References + ---------- + .. [1] P. Erdős and A. Rényi, On Random Graphs, Publ. Math. 6, 290 (1959). + .. [2] E. N. Gilbert, Random Graphs, Ann. Math. Stat., 30, 1141 (1959). + """ + default = nx.DiGraph if directed else nx.Graph + create_using = check_create_using( + create_using, directed=directed, multigraph=False, default=default + ) + if p >= 1: + return complete_graph(n, create_using=create_using) + + G = nx.empty_graph(n, create_using=create_using) + if p <= 0: + return G + + edgetool = itertools.permutations if directed else itertools.combinations + for e in edgetool(range(n), 2): + if seed.random() < p: + G.add_edge(*e) + return G + + +# add some aliases to common names +binomial_graph = gnp_random_graph +erdos_renyi_graph = gnp_random_graph + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def dense_gnm_random_graph(n, m, seed=None, *, create_using=None): + """Returns a $G_{n,m}$ random graph. + + In the $G_{n,m}$ model, a graph is chosen uniformly at random from the set + of all graphs with $n$ nodes and $m$ edges. + + This algorithm should be faster than :func:`gnm_random_graph` for dense + graphs. + + Parameters + ---------- + n : int + The number of nodes. + m : int + The number of edges. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + See Also + -------- + gnm_random_graph + + Notes + ----- + Algorithm by Keith M. Briggs Mar 31, 2006. + Inspired by Knuth's Algorithm S (Selection sampling technique), + in section 3.4.2 of [1]_. + + References + ---------- + .. [1] Donald E. Knuth, The Art of Computer Programming, + Volume 2/Seminumerical algorithms, Third Edition, Addison-Wesley, 1997. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + mmax = n * (n - 1) // 2 + if m >= mmax: + return complete_graph(n, create_using) + G = empty_graph(n, create_using) + + if n == 1: + return G + + u = 0 + v = 1 + t = 0 + k = 0 + while True: + if seed.randrange(mmax - t) < m - k: + G.add_edge(u, v) + k += 1 + if k == m: + return G + t += 1 + v += 1 + if v == n: # go to next row of adjacency matrix + u += 1 + v = u + 1 + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def gnm_random_graph(n, m, seed=None, directed=False, *, create_using=None): + """Returns a $G_{n,m}$ random graph. + + In the $G_{n,m}$ model, a graph is chosen uniformly at random from the set + of all graphs with $n$ nodes and $m$ edges. + + This algorithm should be faster than :func:`dense_gnm_random_graph` for + sparse graphs. + + Parameters + ---------- + n : int + The number of nodes. + m : int + The number of edges. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + directed : bool, optional (default=False) + If True return a directed graph + create_using : Graph constructor, optional (default=nx.Graph or nx.DiGraph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph types are not supported and raise a ``NetworkXError``. + By default NetworkX Graph or DiGraph are used depending on `directed`. + + See also + -------- + dense_gnm_random_graph + + """ + default = nx.DiGraph if directed else nx.Graph + create_using = check_create_using( + create_using, directed=directed, multigraph=False, default=default + ) + if n == 1: + return nx.empty_graph(n, create_using=create_using) + max_edges = n * (n - 1) if directed else n * (n - 1) / 2.0 + if m >= max_edges: + return complete_graph(n, create_using=create_using) + + G = nx.empty_graph(n, create_using=create_using) + nlist = list(G) + edge_count = 0 + while edge_count < m: + # generate random edge,u,v + u = seed.choice(nlist) + v = seed.choice(nlist) + if u == v or G.has_edge(u, v): + continue + else: + G.add_edge(u, v) + edge_count = edge_count + 1 + return G + + +@py_random_state(3) +@nx._dispatchable(graphs=None, returns_graph=True) +def newman_watts_strogatz_graph(n, k, p, seed=None, *, create_using=None): + """Returns a Newman–Watts–Strogatz small-world graph. + + Parameters + ---------- + n : int + The number of nodes. + k : int + Each node is joined with its `k` nearest neighbors in a ring + topology. + p : float + The probability of adding a new edge for each edge. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Notes + ----- + First create a ring over $n$ nodes [1]_. Then each node in the ring is + connected with its $k$ nearest neighbors (or $k - 1$ neighbors if $k$ + is odd). Then shortcuts are created by adding new edges as follows: for + each edge $(u, v)$ in the underlying "$n$-ring with $k$ nearest + neighbors" with probability $p$ add a new edge $(u, w)$ with + randomly-chosen existing node $w$. In contrast with + :func:`watts_strogatz_graph`, no edges are removed. + + See Also + -------- + watts_strogatz_graph + + References + ---------- + .. [1] M. E. J. Newman and D. J. Watts, + Renormalization group analysis of the small-world network model, + Physics Letters A, 263, 341, 1999. + https://doi.org/10.1016/S0375-9601(99)00757-4 + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if k > n: + raise nx.NetworkXError("k>=n, choose smaller k or larger n") + + # If k == n the graph return is a complete graph + if k == n: + return nx.complete_graph(n, create_using) + + G = empty_graph(n, create_using) + nlist = list(G.nodes()) + fromv = nlist + # connect the k/2 neighbors + for j in range(1, k // 2 + 1): + tov = fromv[j:] + fromv[0:j] # the first j are now last + for i in range(len(fromv)): + G.add_edge(fromv[i], tov[i]) + # for each edge u-v, with probability p, randomly select existing + # node w and add new edge u-w + e = list(G.edges()) + for u, v in e: + if seed.random() < p: + w = seed.choice(nlist) + # no self-loops and reject if edge u-w exists + # is that the correct NWS model? + while w == u or G.has_edge(u, w): + w = seed.choice(nlist) + if G.degree(u) >= n - 1: + break # skip this rewiring + else: + G.add_edge(u, w) + return G + + +@py_random_state(3) +@nx._dispatchable(graphs=None, returns_graph=True) +def watts_strogatz_graph(n, k, p, seed=None, *, create_using=None): + """Returns a Watts–Strogatz small-world graph. + + Parameters + ---------- + n : int + The number of nodes + k : int + Each node is joined with its `k` nearest neighbors in a ring + topology. + p : float + The probability of rewiring each edge + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + See Also + -------- + newman_watts_strogatz_graph + connected_watts_strogatz_graph + + Notes + ----- + First create a ring over $n$ nodes [1]_. Then each node in the ring is joined + to its $k$ nearest neighbors (or $k - 1$ neighbors if $k$ is odd). + Then shortcuts are created by replacing some edges as follows: for each + edge $(u, v)$ in the underlying "$n$-ring with $k$ nearest neighbors" + with probability $p$ replace it with a new edge $(u, w)$ with uniformly + random choice of existing node $w$. + + In contrast with :func:`newman_watts_strogatz_graph`, the random rewiring + does not increase the number of edges. The rewired graph is not guaranteed + to be connected as in :func:`connected_watts_strogatz_graph`. + + References + ---------- + .. [1] Duncan J. Watts and Steven H. Strogatz, + Collective dynamics of small-world networks, + Nature, 393, pp. 440--442, 1998. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if k > n: + raise nx.NetworkXError("k>n, choose smaller k or larger n") + + # If k == n, the graph is complete not Watts-Strogatz + if k == n: + G = nx.complete_graph(n, create_using) + return G + + G = nx.empty_graph(n, create_using=create_using) + nodes = list(range(n)) # nodes are labeled 0 to n-1 + # connect each node to k/2 neighbors + for j in range(1, k // 2 + 1): + targets = nodes[j:] + nodes[0:j] # first j nodes are now last in list + G.add_edges_from(zip(nodes, targets)) + # rewire edges from each node + # loop over all nodes in order (label) and neighbors in order (distance) + # no self loops or multiple edges allowed + for j in range(1, k // 2 + 1): # outer loop is neighbors + targets = nodes[j:] + nodes[0:j] # first j nodes are now last in list + # inner loop in node order + for u, v in zip(nodes, targets): + if seed.random() < p: + w = seed.choice(nodes) + # Enforce no self-loops or multiple edges + while w == u or G.has_edge(u, w): + w = seed.choice(nodes) + if G.degree(u) >= n - 1: + break # skip this rewiring + else: + G.remove_edge(u, v) + G.add_edge(u, w) + return G + + +@py_random_state(4) +@nx._dispatchable(graphs=None, returns_graph=True) +def connected_watts_strogatz_graph(n, k, p, tries=100, seed=None, *, create_using=None): + """Returns a connected Watts–Strogatz small-world graph. + + Attempts to generate a connected graph by repeated generation of + Watts–Strogatz small-world graphs. An exception is raised if the maximum + number of tries is exceeded. + + Parameters + ---------- + n : int + The number of nodes + k : int + Each node is joined with its `k` nearest neighbors in a ring + topology. + p : float + The probability of rewiring each edge + tries : int + Number of attempts to generate a connected graph. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Notes + ----- + First create a ring over $n$ nodes [1]_. Then each node in the ring is joined + to its $k$ nearest neighbors (or $k - 1$ neighbors if $k$ is odd). + Then shortcuts are created by replacing some edges as follows: for each + edge $(u, v)$ in the underlying "$n$-ring with $k$ nearest neighbors" + with probability $p$ replace it with a new edge $(u, w)$ with uniformly + random choice of existing node $w$. + The entire process is repeated until a connected graph results. + + See Also + -------- + newman_watts_strogatz_graph + watts_strogatz_graph + + References + ---------- + .. [1] Duncan J. Watts and Steven H. Strogatz, + Collective dynamics of small-world networks, + Nature, 393, pp. 440--442, 1998. + """ + for i in range(tries): + # seed is an RNG so should change sequence each call + G = watts_strogatz_graph(n, k, p, seed, create_using=create_using) + if nx.is_connected(G): + return G + raise nx.NetworkXError("Maximum number of tries exceeded") + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_regular_graph(d, n, seed=None, *, create_using=None): + r"""Returns a random $d$-regular graph on $n$ nodes. + + A regular graph is a graph where each node has the same number of neighbors. + + The resulting graph has no self-loops or parallel edges. + + Parameters + ---------- + d : int + The degree of each node. + n : integer + The number of nodes. The value of $n \times d$ must be even. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Notes + ----- + The nodes are numbered from $0$ to $n - 1$. + + Kim and Vu's paper [2]_ shows that this algorithm samples in an + asymptotically uniform way from the space of random graphs when + $d = O(n^{1 / 3 - \epsilon})$. + + Raises + ------ + + NetworkXError + If $n \times d$ is odd or $d$ is greater than or equal to $n$. + + References + ---------- + .. [1] A. Steger and N. Wormald, + Generating random regular graphs quickly, + Probability and Computing 8 (1999), 377-396, 1999. + https://doi.org/10.1017/S0963548399003867 + + .. [2] Jeong Han Kim and Van H. Vu, + Generating random regular graphs, + Proceedings of the thirty-fifth ACM symposium on Theory of computing, + San Diego, CA, USA, pp 213--222, 2003. + http://portal.acm.org/citation.cfm?id=780542.780576 + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if (n * d) % 2 != 0: + raise nx.NetworkXError("n * d must be even") + + if not 0 <= d < n: + raise nx.NetworkXError("the 0 <= d < n inequality must be satisfied") + + G = nx.empty_graph(n, create_using=create_using) + + if d == 0: + return G + + def _suitable(edges, potential_edges): + # Helper subroutine to check if there are suitable edges remaining + # If False, the generation of the graph has failed + if not potential_edges: + return True + for s1 in potential_edges: + for s2 in potential_edges: + # Two iterators on the same dictionary are guaranteed + # to visit it in the same order if there are no + # intervening modifications. + if s1 == s2: + # Only need to consider s1-s2 pair one time + break + if s1 > s2: + s1, s2 = s2, s1 + if (s1, s2) not in edges: + return True + return False + + def _try_creation(): + # Attempt to create an edge set + + edges = set() + stubs = list(range(n)) * d + + while stubs: + potential_edges = defaultdict(lambda: 0) + seed.shuffle(stubs) + stubiter = iter(stubs) + for s1, s2 in zip(stubiter, stubiter): + if s1 > s2: + s1, s2 = s2, s1 + if s1 != s2 and ((s1, s2) not in edges): + edges.add((s1, s2)) + else: + potential_edges[s1] += 1 + potential_edges[s2] += 1 + + if not _suitable(edges, potential_edges): + return None # failed to find suitable edge set + + stubs = [ + node + for node, potential in potential_edges.items() + for _ in range(potential) + ] + return edges + + # Even though a suitable edge set exists, + # the generation of such a set is not guaranteed. + # Try repeatedly to find one. + edges = _try_creation() + while edges is None: + edges = _try_creation() + G.add_edges_from(edges) + + return G + + +def _random_subset(seq, m, rng): + """Return m unique elements from seq. + + This differs from random.sample which can return repeated + elements if seq holds repeated elements. + + Note: rng is a random.Random or numpy.random.RandomState instance. + """ + targets = set() + while len(targets) < m: + x = rng.choice(seq) + targets.add(x) + return targets + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def barabasi_albert_graph(n, m, seed=None, initial_graph=None, *, create_using=None): + """Returns a random graph using Barabási–Albert preferential attachment + + A graph of $n$ nodes is grown by attaching new nodes each with $m$ + edges that are preferentially attached to existing nodes with high degree. + + Parameters + ---------- + n : int + Number of nodes + m : int + Number of edges to attach from a new node to existing nodes + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + initial_graph : Graph or None (default) + Initial network for Barabási–Albert algorithm. + It should be a connected graph for most use cases. + A copy of `initial_graph` is used. + If None, starts from a star graph on (m+1) nodes. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Returns + ------- + G : Graph + + Raises + ------ + NetworkXError + If `m` does not satisfy ``1 <= m < n``, or + the initial graph number of nodes m0 does not satisfy ``m <= m0 <= n``. + + References + ---------- + .. [1] A. L. Barabási and R. Albert "Emergence of scaling in + random networks", Science 286, pp 509-512, 1999. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if m < 1 or m >= n: + raise nx.NetworkXError( + f"Barabási–Albert network must have m >= 1 and m < n, m = {m}, n = {n}" + ) + + if initial_graph is None: + # Default initial graph : star graph on (m + 1) nodes + G = star_graph(m, create_using) + else: + if len(initial_graph) < m or len(initial_graph) > n: + raise nx.NetworkXError( + f"Barabási–Albert initial graph needs between m={m} and n={n} nodes" + ) + G = initial_graph.copy() + + # List of existing nodes, with nodes repeated once for each adjacent edge + repeated_nodes = [n for n, d in G.degree() for _ in range(d)] + # Start adding the other n - m0 nodes. + source = len(G) + while source < n: + # Now choose m unique nodes from the existing nodes + # Pick uniformly from repeated_nodes (preferential attachment) + targets = _random_subset(repeated_nodes, m, seed) + # Add edges to m nodes from the source. + G.add_edges_from(zip([source] * m, targets)) + # Add one node to the list for each new edge just created. + repeated_nodes.extend(targets) + # And the new node "source" has m edges to add to the list. + repeated_nodes.extend([source] * m) + + source += 1 + return G + + +@py_random_state(4) +@nx._dispatchable(graphs=None, returns_graph=True) +def dual_barabasi_albert_graph( + n, m1, m2, p, seed=None, initial_graph=None, *, create_using=None +): + """Returns a random graph using dual Barabási–Albert preferential attachment + + A graph of $n$ nodes is grown by attaching new nodes each with either $m_1$ + edges (with probability $p$) or $m_2$ edges (with probability $1-p$) that + are preferentially attached to existing nodes with high degree. + + Parameters + ---------- + n : int + Number of nodes + m1 : int + Number of edges to link each new node to existing nodes with probability $p$ + m2 : int + Number of edges to link each new node to existing nodes with probability $1-p$ + p : float + The probability of attaching $m_1$ edges (as opposed to $m_2$ edges) + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + initial_graph : Graph or None (default) + Initial network for Barabási–Albert algorithm. + A copy of `initial_graph` is used. + It should be connected for most use cases. + If None, starts from an star graph on max(m1, m2) + 1 nodes. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Returns + ------- + G : Graph + + Raises + ------ + NetworkXError + If `m1` and `m2` do not satisfy ``1 <= m1,m2 < n``, or + `p` does not satisfy ``0 <= p <= 1``, or + the initial graph number of nodes m0 does not satisfy m1, m2 <= m0 <= n. + + References + ---------- + .. [1] N. Moshiri "The dual-Barabasi-Albert model", arXiv:1810.10538. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if m1 < 1 or m1 >= n: + raise nx.NetworkXError( + f"Dual Barabási–Albert must have m1 >= 1 and m1 < n, m1 = {m1}, n = {n}" + ) + if m2 < 1 or m2 >= n: + raise nx.NetworkXError( + f"Dual Barabási–Albert must have m2 >= 1 and m2 < n, m2 = {m2}, n = {n}" + ) + if p < 0 or p > 1: + raise nx.NetworkXError( + f"Dual Barabási–Albert network must have 0 <= p <= 1, p = {p}" + ) + + # For simplicity, if p == 0 or 1, just return BA + if p == 1: + return barabasi_albert_graph(n, m1, seed, create_using=create_using) + elif p == 0: + return barabasi_albert_graph(n, m2, seed, create_using=create_using) + + if initial_graph is None: + # Default initial graph : star graph on max(m1, m2) nodes + G = star_graph(max(m1, m2), create_using) + else: + if len(initial_graph) < max(m1, m2) or len(initial_graph) > n: + raise nx.NetworkXError( + f"Barabási–Albert initial graph must have between " + f"max(m1, m2) = {max(m1, m2)} and n = {n} nodes" + ) + G = initial_graph.copy() + + # Target nodes for new edges + targets = list(G) + # List of existing nodes, with nodes repeated once for each adjacent edge + repeated_nodes = [n for n, d in G.degree() for _ in range(d)] + # Start adding the remaining nodes. + source = len(G) + while source < n: + # Pick which m to use (m1 or m2) + if seed.random() < p: + m = m1 + else: + m = m2 + # Now choose m unique nodes from the existing nodes + # Pick uniformly from repeated_nodes (preferential attachment) + targets = _random_subset(repeated_nodes, m, seed) + # Add edges to m nodes from the source. + G.add_edges_from(zip([source] * m, targets)) + # Add one node to the list for each new edge just created. + repeated_nodes.extend(targets) + # And the new node "source" has m edges to add to the list. + repeated_nodes.extend([source] * m) + + source += 1 + return G + + +@py_random_state(4) +@nx._dispatchable(graphs=None, returns_graph=True) +def extended_barabasi_albert_graph(n, m, p, q, seed=None, *, create_using=None): + """Returns an extended Barabási–Albert model graph. + + An extended Barabási–Albert model graph is a random graph constructed + using preferential attachment. The extended model allows new edges, + rewired edges or new nodes. Based on the probabilities $p$ and $q$ + with $p + q < 1$, the growing behavior of the graph is determined as: + + 1) With $p$ probability, $m$ new edges are added to the graph, + starting from randomly chosen existing nodes and attached preferentially at the + other end. + + 2) With $q$ probability, $m$ existing edges are rewired + by randomly choosing an edge and rewiring one end to a preferentially chosen node. + + 3) With $(1 - p - q)$ probability, $m$ new nodes are added to the graph + with edges attached preferentially. + + When $p = q = 0$, the model behaves just like the Barabási–Alber model. + + Parameters + ---------- + n : int + Number of nodes + m : int + Number of edges with which a new node attaches to existing nodes + p : float + Probability value for adding an edge between existing nodes. p + q < 1 + q : float + Probability value of rewiring of existing edges. p + q < 1 + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Returns + ------- + G : Graph + + Raises + ------ + NetworkXError + If `m` does not satisfy ``1 <= m < n`` or ``1 >= p + q`` + + References + ---------- + .. [1] Albert, R., & Barabási, A. L. (2000) + Topology of evolving networks: local events and universality + Physical review letters, 85(24), 5234. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if m < 1 or m >= n: + msg = f"Extended Barabasi-Albert network needs m>=1 and m= 1: + msg = f"Extended Barabasi-Albert network needs p + q <= 1, p={p}, q={q}" + raise nx.NetworkXError(msg) + + # Add m initial nodes (m0 in barabasi-speak) + G = empty_graph(m, create_using) + + # List of nodes to represent the preferential attachment random selection. + # At the creation of the graph, all nodes are added to the list + # so that even nodes that are not connected have a chance to get selected, + # for rewiring and adding of edges. + # With each new edge, nodes at the ends of the edge are added to the list. + attachment_preference = [] + attachment_preference.extend(range(m)) + + # Start adding the other n-m nodes. The first node is m. + new_node = m + while new_node < n: + a_probability = seed.random() + + # Total number of edges of a Clique of all the nodes + clique_degree = len(G) - 1 + clique_size = (len(G) * clique_degree) / 2 + + # Adding m new edges, if there is room to add them + if a_probability < p and G.size() <= clique_size - m: + # Select the nodes where an edge can be added + eligible_nodes = [nd for nd, deg in G.degree() if deg < clique_degree] + for i in range(m): + # Choosing a random source node from eligible_nodes + src_node = seed.choice(eligible_nodes) + + # Picking a possible node that is not 'src_node' or + # neighbor with 'src_node', with preferential attachment + prohibited_nodes = list(G[src_node]) + prohibited_nodes.append(src_node) + # This will raise an exception if the sequence is empty + dest_node = seed.choice( + [nd for nd in attachment_preference if nd not in prohibited_nodes] + ) + # Adding the new edge + G.add_edge(src_node, dest_node) + + # Appending both nodes to add to their preferential attachment + attachment_preference.append(src_node) + attachment_preference.append(dest_node) + + # Adjusting the eligible nodes. Degree may be saturated. + if G.degree(src_node) == clique_degree: + eligible_nodes.remove(src_node) + if G.degree(dest_node) == clique_degree and dest_node in eligible_nodes: + eligible_nodes.remove(dest_node) + + # Rewiring m edges, if there are enough edges + elif p <= a_probability < (p + q) and m <= G.size() < clique_size: + # Selecting nodes that have at least 1 edge but that are not + # fully connected to ALL other nodes (center of star). + # These nodes are the pivot nodes of the edges to rewire + eligible_nodes = [nd for nd, deg in G.degree() if 0 < deg < clique_degree] + for i in range(m): + # Choosing a random source node + node = seed.choice(eligible_nodes) + + # The available nodes do have a neighbor at least. + nbr_nodes = list(G[node]) + + # Choosing the other end that will get detached + src_node = seed.choice(nbr_nodes) + + # Picking a target node that is not 'node' or + # neighbor with 'node', with preferential attachment + nbr_nodes.append(node) + dest_node = seed.choice( + [nd for nd in attachment_preference if nd not in nbr_nodes] + ) + # Rewire + G.remove_edge(node, src_node) + G.add_edge(node, dest_node) + + # Adjusting the preferential attachment list + attachment_preference.remove(src_node) + attachment_preference.append(dest_node) + + # Adjusting the eligible nodes. + # nodes may be saturated or isolated. + if G.degree(src_node) == 0 and src_node in eligible_nodes: + eligible_nodes.remove(src_node) + if dest_node in eligible_nodes: + if G.degree(dest_node) == clique_degree: + eligible_nodes.remove(dest_node) + else: + if G.degree(dest_node) == 1: + eligible_nodes.append(dest_node) + + # Adding new node with m edges + else: + # Select the edges' nodes by preferential attachment + targets = _random_subset(attachment_preference, m, seed) + G.add_edges_from(zip([new_node] * m, targets)) + + # Add one node to the list for each new edge just created. + attachment_preference.extend(targets) + # The new node has m edges to it, plus itself: m + 1 + attachment_preference.extend([new_node] * (m + 1)) + new_node += 1 + return G + + +@py_random_state(3) +@nx._dispatchable(graphs=None, returns_graph=True) +def powerlaw_cluster_graph(n, m, p, seed=None, *, create_using=None): + """Holme and Kim algorithm for growing graphs with powerlaw + degree distribution and approximate average clustering. + + Parameters + ---------- + n : int + the number of nodes + m : int + the number of random edges to add for each new node + p : float, + Probability of adding a triangle after adding a random edge + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Notes + ----- + The average clustering has a hard time getting above a certain + cutoff that depends on `m`. This cutoff is often quite low. The + transitivity (fraction of triangles to possible triangles) seems to + decrease with network size. + + It is essentially the Barabási–Albert (BA) growth model with an + extra step that each random edge is followed by a chance of + making an edge to one of its neighbors too (and thus a triangle). + + This algorithm improves on BA in the sense that it enables a + higher average clustering to be attained if desired. + + It seems possible to have a disconnected graph with this algorithm + since the initial `m` nodes may not be all linked to a new node + on the first iteration like the BA model. + + Raises + ------ + NetworkXError + If `m` does not satisfy ``1 <= m <= n`` or `p` does not + satisfy ``0 <= p <= 1``. + + References + ---------- + .. [1] P. Holme and B. J. Kim, + "Growing scale-free networks with tunable clustering", + Phys. Rev. E, 65, 026107, 2002. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if m < 1 or n < m: + raise nx.NetworkXError(f"NetworkXError must have m>1 and m 1 or p < 0: + raise nx.NetworkXError(f"NetworkXError p must be in [0,1], p={p}") + + G = empty_graph(m, create_using) # add m initial nodes (m0 in barabasi-speak) + repeated_nodes = list(G) # list of existing nodes to sample from + # with nodes repeated once for each adjacent edge + source = m # next node is m + while source < n: # Now add the other n-1 nodes + possible_targets = _random_subset(repeated_nodes, m, seed) + # do one preferential attachment for new node + target = possible_targets.pop() + G.add_edge(source, target) + repeated_nodes.append(target) # add one node to list for each new link + count = 1 + while count < m: # add m-1 more new links + if seed.random() < p: # clustering step: add triangle + neighborhood = [ + nbr + for nbr in G.neighbors(target) + if not G.has_edge(source, nbr) and nbr != source + ] + if neighborhood: # if there is a neighbor without a link + nbr = seed.choice(neighborhood) + G.add_edge(source, nbr) # add triangle + repeated_nodes.append(nbr) + count = count + 1 + continue # go to top of while loop + # else do preferential attachment step if above fails + target = possible_targets.pop() + G.add_edge(source, target) + repeated_nodes.append(target) + count = count + 1 + + repeated_nodes.extend([source] * m) # add source node to list m times + source += 1 + return G + + +@py_random_state(3) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_lobster(n, p1, p2, seed=None, *, create_using=None): + """Returns a random lobster graph. + + A lobster is a tree that reduces to a caterpillar when pruning all + leaf nodes. A caterpillar is a tree that reduces to a path graph + when pruning all leaf nodes; setting `p2` to zero produces a caterpillar. + + This implementation iterates on the probabilities `p1` and `p2` to add + edges at levels 1 and 2, respectively. Graphs are therefore constructed + iteratively with uniform randomness at each level rather than being selected + uniformly at random from the set of all possible lobsters. + + Parameters + ---------- + n : int + The expected number of nodes in the backbone + p1 : float + Probability of adding an edge to the backbone + p2 : float + Probability of adding an edge one level beyond backbone + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Grap) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Raises + ------ + NetworkXError + If `p1` or `p2` parameters are >= 1 because the while loops would never finish. + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + p1, p2 = abs(p1), abs(p2) + if any(p >= 1 for p in [p1, p2]): + raise nx.NetworkXError("Probability values for `p1` and `p2` must both be < 1.") + + # a necessary ingredient in any self-respecting graph library + llen = int(2 * seed.random() * n + 0.5) + L = path_graph(llen, create_using) + # build caterpillar: add edges to path graph with probability p1 + current_node = llen - 1 + for n in range(llen): + while seed.random() < p1: # add fuzzy caterpillar parts + current_node += 1 + L.add_edge(n, current_node) + cat_node = current_node + while seed.random() < p2: # add crunchy lobster bits + current_node += 1 + L.add_edge(cat_node, current_node) + return L # voila, un lobster! + + +@py_random_state(1) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_shell_graph(constructor, seed=None, *, create_using=None): + """Returns a random shell graph for the constructor given. + + Parameters + ---------- + constructor : list of three-tuples + Represents the parameters for a shell, starting at the center + shell. Each element of the list must be of the form `(n, m, + d)`, where `n` is the number of nodes in the shell, `m` is + the number of edges in the shell, and `d` is the ratio of + inter-shell (next) edges to intra-shell edges. If `d` is zero, + there will be no intra-shell edges, and if `d` is one there + will be all possible intra-shell edges. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. Graph instances are not supported. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Examples + -------- + >>> constructor = [(10, 20, 0.8), (20, 40, 0.8)] + >>> G = nx.random_shell_graph(constructor) + + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + G = empty_graph(0, create_using) + + glist = [] + intra_edges = [] + nnodes = 0 + # create gnm graphs for each shell + for n, m, d in constructor: + inter_edges = int(m * d) + intra_edges.append(m - inter_edges) + g = nx.convert_node_labels_to_integers( + gnm_random_graph(n, inter_edges, seed=seed, create_using=G.__class__), + first_label=nnodes, + ) + glist.append(g) + nnodes += n + G = nx.operators.union(G, g) + + # connect the shells randomly + for gi in range(len(glist) - 1): + nlist1 = list(glist[gi]) + nlist2 = list(glist[gi + 1]) + total_edges = intra_edges[gi] + edge_count = 0 + while edge_count < total_edges: + u = seed.choice(nlist1) + v = seed.choice(nlist2) + if u == v or G.has_edge(u, v): + continue + else: + G.add_edge(u, v) + edge_count = edge_count + 1 + return G + + +@py_random_state(2) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_powerlaw_tree(n, gamma=3, seed=None, tries=100, *, create_using=None): + """Returns a tree with a power law degree distribution. + + Parameters + ---------- + n : int + The number of nodes. + gamma : float + Exponent of the power law. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + tries : int + Number of attempts to adjust the sequence to make it a tree. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Raises + ------ + NetworkXError + If no valid sequence is found within the maximum number of + attempts. + + Notes + ----- + A trial power law degree sequence is chosen and then elements are + swapped with new elements from a powerlaw distribution until the + sequence makes a tree (by checking, for example, that the number of + edges is one smaller than the number of nodes). + + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + # This call may raise a NetworkXError if the number of tries is succeeded. + seq = random_powerlaw_tree_sequence(n, gamma=gamma, seed=seed, tries=tries) + G = degree_sequence_tree(seq, create_using) + return G + + +@py_random_state(2) +@nx._dispatchable(graphs=None) +def random_powerlaw_tree_sequence(n, gamma=3, seed=None, tries=100): + """Returns a degree sequence for a tree with a power law distribution. + + Parameters + ---------- + n : int, + The number of nodes. + gamma : float + Exponent of the power law. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + tries : int + Number of attempts to adjust the sequence to make it a tree. + + Raises + ------ + NetworkXError + If no valid sequence is found within the maximum number of + attempts. + + Notes + ----- + A trial power law degree sequence is chosen and then elements are + swapped with new elements from a power law distribution until + the sequence makes a tree (by checking, for example, that the number of + edges is one smaller than the number of nodes). + + """ + # get trial sequence + z = nx.utils.powerlaw_sequence(n, exponent=gamma, seed=seed) + # round to integer values in the range [0,n] + zseq = [min(n, max(round(s), 0)) for s in z] + + # another sequence to swap values from + z = nx.utils.powerlaw_sequence(tries, exponent=gamma, seed=seed) + # round to integer values in the range [0,n] + swap = [min(n, max(round(s), 0)) for s in z] + + for deg in swap: + # If this degree sequence can be the degree sequence of a tree, return + # it. It can be a tree if the number of edges is one fewer than the + # number of nodes, or in other words, `n - sum(zseq) / 2 == 1`. We + # use an equivalent condition below that avoids floating point + # operations. + if 2 * n - sum(zseq) == 2: + return zseq + index = seed.randint(0, n - 1) + zseq[index] = swap.pop() + + raise nx.NetworkXError( + f"Exceeded max ({tries}) attempts for a valid tree sequence." + ) + + +@py_random_state(3) +@nx._dispatchable(graphs=None, returns_graph=True) +def random_kernel_graph( + n, kernel_integral, kernel_root=None, seed=None, *, create_using=None +): + r"""Returns an random graph based on the specified kernel. + + The algorithm chooses each of the $[n(n-1)]/2$ possible edges with + probability specified by a kernel $\kappa(x,y)$ [1]_. The kernel + $\kappa(x,y)$ must be a symmetric (in $x,y$), non-negative, + bounded function. + + Parameters + ---------- + n : int + The number of nodes + kernel_integral : function + Function that returns the definite integral of the kernel $\kappa(x,y)$, + $F(y,a,b) := \int_a^b \kappa(x,y)dx$ + kernel_root: function (optional) + Function that returns the root $b$ of the equation $F(y,a,b) = r$. + If None, the root is found using :func:`scipy.optimize.brentq` + (this requires SciPy). + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + create_using : Graph constructor, optional (default=nx.Graph) + Graph type to create. If graph instance, then cleared before populated. + Multigraph and directed types are not supported and raise a ``NetworkXError``. + + Notes + ----- + The kernel is specified through its definite integral which must be + provided as one of the arguments. If the integral and root of the + kernel integral can be found in $O(1)$ time then this algorithm runs in + time $O(n+m)$ where m is the expected number of edges [2]_. + + The nodes are set to integers from $0$ to $n-1$. + + Examples + -------- + Generate an Erdős–Rényi random graph $G(n,c/n)$, with kernel + $\kappa(x,y)=c$ where $c$ is the mean expected degree. + + >>> def integral(u, w, z): + ... return c * (z - w) + >>> def root(u, w, r): + ... return r / c + w + >>> c = 1 + >>> graph = nx.random_kernel_graph(1000, integral, root) + + See Also + -------- + gnp_random_graph + expected_degree_graph + + References + ---------- + .. [1] Bollobás, Béla, Janson, S. and Riordan, O. + "The phase transition in inhomogeneous random graphs", + *Random Structures Algorithms*, 31, 3--122, 2007. + + .. [2] Hagberg A, Lemons N (2015), + "Fast Generation of Sparse Random Kernel Graphs". + PLoS ONE 10(9): e0135177, 2015. doi:10.1371/journal.pone.0135177 + """ + create_using = check_create_using(create_using, directed=False, multigraph=False) + if kernel_root is None: + import scipy as sp + + def kernel_root(y, a, r): + def my_function(b): + return kernel_integral(y, a, b) - r + + return sp.optimize.brentq(my_function, a, 1) + + graph = nx.empty_graph(create_using=create_using) + graph.add_nodes_from(range(n)) + (i, j) = (1, 1) + while i < n: + r = -math.log(1 - seed.random()) # (1-seed.random()) in (0, 1] + if kernel_integral(i / n, j / n, 1) <= r: + i, j = i + 1, i + 1 + else: + j = math.ceil(n * kernel_root(i / n, j / n, r)) + graph.add_edge(i - 1, j - 1) + return graph diff --git a/janus/lib/python3.10/site-packages/networkx/generators/social.py b/janus/lib/python3.10/site-packages/networkx/generators/social.py new file mode 100644 index 0000000000000000000000000000000000000000..f41b2d88b4bc09f4e45967731f1dc8acfb48420b --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/social.py @@ -0,0 +1,554 @@ +""" +Famous social networks. +""" + +import networkx as nx + +__all__ = [ + "karate_club_graph", + "davis_southern_women_graph", + "florentine_families_graph", + "les_miserables_graph", +] + + +@nx._dispatchable(graphs=None, returns_graph=True) +def karate_club_graph(): + """Returns Zachary's Karate Club graph. + + Each node in the returned graph has a node attribute 'club' that + indicates the name of the club to which the member represented by that node + belongs, either 'Mr. Hi' or 'Officer'. Each edge has a weight based on the + number of contexts in which that edge's incident node members interacted. + + The dataset is derived from the 'Club After Split From Data' column of Table 3 in [1]_. + This was in turn derived from the 'Club After Fission' column of Table 1 in the + same paper. Note that the nodes are 0-indexed in NetworkX, but 1-indexed in the + paper (the 'Individual Number in Matrix C' column of Table 3 starts at 1). This + means, for example, that ``G.nodes[9]["club"]`` returns 'Officer', which + corresponds to row 10 of Table 3 in the paper. + + Examples + -------- + To get the name of the club to which a node belongs:: + + >>> G = nx.karate_club_graph() + >>> G.nodes[5]["club"] + 'Mr. Hi' + >>> G.nodes[9]["club"] + 'Officer' + + References + ---------- + .. [1] Zachary, Wayne W. + "An Information Flow Model for Conflict and Fission in Small Groups." + *Journal of Anthropological Research*, 33, 452--473, (1977). + """ + # Create the set of all members, and the members of each club. + all_members = set(range(34)) + club1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 16, 17, 19, 21} + # club2 = all_members - club1 + + G = nx.Graph() + G.add_nodes_from(all_members) + G.name = "Zachary's Karate Club" + + zacharydat = """\ +0 4 5 3 3 3 3 2 2 0 2 3 2 3 0 0 0 2 0 2 0 2 0 0 0 0 0 0 0 0 0 2 0 0 +4 0 6 3 0 0 0 4 0 0 0 0 0 5 0 0 0 1 0 2 0 2 0 0 0 0 0 0 0 0 2 0 0 0 +5 6 0 3 0 0 0 4 5 1 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 0 0 0 3 0 +3 3 3 0 0 0 0 3 0 0 0 0 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +3 0 0 0 0 0 2 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +3 0 0 0 0 0 5 0 0 0 3 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +3 0 0 0 2 5 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +2 4 4 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +2 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 4 3 +0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 +2 0 0 0 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +1 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +3 5 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 2 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 4 +0 0 0 0 0 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 +2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 1 +2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 4 0 2 0 0 5 4 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 3 0 0 0 2 0 0 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 2 0 0 0 0 0 0 7 0 0 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 2 +0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 3 0 0 0 0 0 0 0 0 4 +0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 2 +0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 4 0 0 0 0 0 3 2 +0 2 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 3 +2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 7 0 0 2 0 0 0 4 4 +0 0 2 0 0 0 0 0 3 0 0 0 0 0 3 3 0 0 1 0 3 0 2 5 0 0 0 0 0 4 3 4 0 5 +0 0 0 0 0 0 0 0 4 2 0 0 0 3 2 4 0 0 2 1 1 0 3 4 0 0 2 4 2 2 3 4 5 0""" + + for row, line in enumerate(zacharydat.split("\n")): + thisrow = [int(b) for b in line.split()] + for col, entry in enumerate(thisrow): + if entry >= 1: + G.add_edge(row, col, weight=entry) + + # Add the name of each member's club as a node attribute. + for v in G: + G.nodes[v]["club"] = "Mr. Hi" if v in club1 else "Officer" + return G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def davis_southern_women_graph(): + """Returns Davis Southern women social network. + + This is a bipartite graph. + + References + ---------- + .. [1] A. Davis, Gardner, B. B., Gardner, M. R., 1941. Deep South. + University of Chicago Press, Chicago, IL. + """ + G = nx.Graph() + # Top nodes + women = [ + "Evelyn Jefferson", + "Laura Mandeville", + "Theresa Anderson", + "Brenda Rogers", + "Charlotte McDowd", + "Frances Anderson", + "Eleanor Nye", + "Pearl Oglethorpe", + "Ruth DeSand", + "Verne Sanderson", + "Myra Liddel", + "Katherina Rogers", + "Sylvia Avondale", + "Nora Fayette", + "Helen Lloyd", + "Dorothy Murchison", + "Olivia Carleton", + "Flora Price", + ] + G.add_nodes_from(women, bipartite=0) + # Bottom nodes + events = [ + "E1", + "E2", + "E3", + "E4", + "E5", + "E6", + "E7", + "E8", + "E9", + "E10", + "E11", + "E12", + "E13", + "E14", + ] + G.add_nodes_from(events, bipartite=1) + + G.add_edges_from( + [ + ("Evelyn Jefferson", "E1"), + ("Evelyn Jefferson", "E2"), + ("Evelyn Jefferson", "E3"), + ("Evelyn Jefferson", "E4"), + ("Evelyn Jefferson", "E5"), + ("Evelyn Jefferson", "E6"), + ("Evelyn Jefferson", "E8"), + ("Evelyn Jefferson", "E9"), + ("Laura Mandeville", "E1"), + ("Laura Mandeville", "E2"), + ("Laura Mandeville", "E3"), + ("Laura Mandeville", "E5"), + ("Laura Mandeville", "E6"), + ("Laura Mandeville", "E7"), + ("Laura Mandeville", "E8"), + ("Theresa Anderson", "E2"), + ("Theresa Anderson", "E3"), + ("Theresa Anderson", "E4"), + ("Theresa Anderson", "E5"), + ("Theresa Anderson", "E6"), + ("Theresa Anderson", "E7"), + ("Theresa Anderson", "E8"), + ("Theresa Anderson", "E9"), + ("Brenda Rogers", "E1"), + ("Brenda Rogers", "E3"), + ("Brenda Rogers", "E4"), + ("Brenda Rogers", "E5"), + ("Brenda Rogers", "E6"), + ("Brenda Rogers", "E7"), + ("Brenda Rogers", "E8"), + ("Charlotte McDowd", "E3"), + ("Charlotte McDowd", "E4"), + ("Charlotte McDowd", "E5"), + ("Charlotte McDowd", "E7"), + ("Frances Anderson", "E3"), + ("Frances Anderson", "E5"), + ("Frances Anderson", "E6"), + ("Frances Anderson", "E8"), + ("Eleanor Nye", "E5"), + ("Eleanor Nye", "E6"), + ("Eleanor Nye", "E7"), + ("Eleanor Nye", "E8"), + ("Pearl Oglethorpe", "E6"), + ("Pearl Oglethorpe", "E8"), + ("Pearl Oglethorpe", "E9"), + ("Ruth DeSand", "E5"), + ("Ruth DeSand", "E7"), + ("Ruth DeSand", "E8"), + ("Ruth DeSand", "E9"), + ("Verne Sanderson", "E7"), + ("Verne Sanderson", "E8"), + ("Verne Sanderson", "E9"), + ("Verne Sanderson", "E12"), + ("Myra Liddel", "E8"), + ("Myra Liddel", "E9"), + ("Myra Liddel", "E10"), + ("Myra Liddel", "E12"), + ("Katherina Rogers", "E8"), + ("Katherina Rogers", "E9"), + ("Katherina Rogers", "E10"), + ("Katherina Rogers", "E12"), + ("Katherina Rogers", "E13"), + ("Katherina Rogers", "E14"), + ("Sylvia Avondale", "E7"), + ("Sylvia Avondale", "E8"), + ("Sylvia Avondale", "E9"), + ("Sylvia Avondale", "E10"), + ("Sylvia Avondale", "E12"), + ("Sylvia Avondale", "E13"), + ("Sylvia Avondale", "E14"), + ("Nora Fayette", "E6"), + ("Nora Fayette", "E7"), + ("Nora Fayette", "E9"), + ("Nora Fayette", "E10"), + ("Nora Fayette", "E11"), + ("Nora Fayette", "E12"), + ("Nora Fayette", "E13"), + ("Nora Fayette", "E14"), + ("Helen Lloyd", "E7"), + ("Helen Lloyd", "E8"), + ("Helen Lloyd", "E10"), + ("Helen Lloyd", "E11"), + ("Helen Lloyd", "E12"), + ("Dorothy Murchison", "E8"), + ("Dorothy Murchison", "E9"), + ("Olivia Carleton", "E9"), + ("Olivia Carleton", "E11"), + ("Flora Price", "E9"), + ("Flora Price", "E11"), + ] + ) + G.graph["top"] = women + G.graph["bottom"] = events + return G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def florentine_families_graph(): + """Returns Florentine families graph. + + References + ---------- + .. [1] Ronald L. Breiger and Philippa E. Pattison + Cumulated social roles: The duality of persons and their algebras,1 + Social Networks, Volume 8, Issue 3, September 1986, Pages 215-256 + """ + G = nx.Graph() + G.add_edge("Acciaiuoli", "Medici") + G.add_edge("Castellani", "Peruzzi") + G.add_edge("Castellani", "Strozzi") + G.add_edge("Castellani", "Barbadori") + G.add_edge("Medici", "Barbadori") + G.add_edge("Medici", "Ridolfi") + G.add_edge("Medici", "Tornabuoni") + G.add_edge("Medici", "Albizzi") + G.add_edge("Medici", "Salviati") + G.add_edge("Salviati", "Pazzi") + G.add_edge("Peruzzi", "Strozzi") + G.add_edge("Peruzzi", "Bischeri") + G.add_edge("Strozzi", "Ridolfi") + G.add_edge("Strozzi", "Bischeri") + G.add_edge("Ridolfi", "Tornabuoni") + G.add_edge("Tornabuoni", "Guadagni") + G.add_edge("Albizzi", "Ginori") + G.add_edge("Albizzi", "Guadagni") + G.add_edge("Bischeri", "Guadagni") + G.add_edge("Guadagni", "Lamberteschi") + return G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def les_miserables_graph(): + """Returns coappearance network of characters in the novel Les Miserables. + + References + ---------- + .. [1] D. E. Knuth, 1993. + The Stanford GraphBase: a platform for combinatorial computing, + pp. 74-87. New York: AcM Press. + """ + G = nx.Graph() + G.add_edge("Napoleon", "Myriel", weight=1) + G.add_edge("MlleBaptistine", "Myriel", weight=8) + G.add_edge("MmeMagloire", "Myriel", weight=10) + G.add_edge("MmeMagloire", "MlleBaptistine", weight=6) + G.add_edge("CountessDeLo", "Myriel", weight=1) + G.add_edge("Geborand", "Myriel", weight=1) + G.add_edge("Champtercier", "Myriel", weight=1) + G.add_edge("Cravatte", "Myriel", weight=1) + G.add_edge("Count", "Myriel", weight=2) + G.add_edge("OldMan", "Myriel", weight=1) + G.add_edge("Valjean", "Labarre", weight=1) + G.add_edge("Valjean", "MmeMagloire", weight=3) + G.add_edge("Valjean", "MlleBaptistine", weight=3) + G.add_edge("Valjean", "Myriel", weight=5) + G.add_edge("Marguerite", "Valjean", weight=1) + G.add_edge("MmeDeR", "Valjean", weight=1) + G.add_edge("Isabeau", "Valjean", weight=1) + G.add_edge("Gervais", "Valjean", weight=1) + G.add_edge("Listolier", "Tholomyes", weight=4) + G.add_edge("Fameuil", "Tholomyes", weight=4) + G.add_edge("Fameuil", "Listolier", weight=4) + G.add_edge("Blacheville", "Tholomyes", weight=4) + G.add_edge("Blacheville", "Listolier", weight=4) + G.add_edge("Blacheville", "Fameuil", weight=4) + G.add_edge("Favourite", "Tholomyes", weight=3) + G.add_edge("Favourite", "Listolier", weight=3) + G.add_edge("Favourite", "Fameuil", weight=3) + G.add_edge("Favourite", "Blacheville", weight=4) + G.add_edge("Dahlia", "Tholomyes", weight=3) + G.add_edge("Dahlia", "Listolier", weight=3) + G.add_edge("Dahlia", "Fameuil", weight=3) + G.add_edge("Dahlia", "Blacheville", weight=3) + G.add_edge("Dahlia", "Favourite", weight=5) + G.add_edge("Zephine", "Tholomyes", weight=3) + G.add_edge("Zephine", "Listolier", weight=3) + G.add_edge("Zephine", "Fameuil", weight=3) + G.add_edge("Zephine", "Blacheville", weight=3) + G.add_edge("Zephine", "Favourite", weight=4) + G.add_edge("Zephine", "Dahlia", weight=4) + G.add_edge("Fantine", "Tholomyes", weight=3) + G.add_edge("Fantine", "Listolier", weight=3) + G.add_edge("Fantine", "Fameuil", weight=3) + G.add_edge("Fantine", "Blacheville", weight=3) + G.add_edge("Fantine", "Favourite", weight=4) + G.add_edge("Fantine", "Dahlia", weight=4) + G.add_edge("Fantine", "Zephine", weight=4) + G.add_edge("Fantine", "Marguerite", weight=2) + G.add_edge("Fantine", "Valjean", weight=9) + G.add_edge("MmeThenardier", "Fantine", weight=2) + G.add_edge("MmeThenardier", "Valjean", weight=7) + G.add_edge("Thenardier", "MmeThenardier", weight=13) + G.add_edge("Thenardier", "Fantine", weight=1) + G.add_edge("Thenardier", "Valjean", weight=12) + G.add_edge("Cosette", "MmeThenardier", weight=4) + G.add_edge("Cosette", "Valjean", weight=31) + G.add_edge("Cosette", "Tholomyes", weight=1) + G.add_edge("Cosette", "Thenardier", weight=1) + G.add_edge("Javert", "Valjean", weight=17) + G.add_edge("Javert", "Fantine", weight=5) + G.add_edge("Javert", "Thenardier", weight=5) + G.add_edge("Javert", "MmeThenardier", weight=1) + G.add_edge("Javert", "Cosette", weight=1) + G.add_edge("Fauchelevent", "Valjean", weight=8) + G.add_edge("Fauchelevent", "Javert", weight=1) + G.add_edge("Bamatabois", "Fantine", weight=1) + G.add_edge("Bamatabois", "Javert", weight=1) + G.add_edge("Bamatabois", "Valjean", weight=2) + G.add_edge("Perpetue", "Fantine", weight=1) + G.add_edge("Simplice", "Perpetue", weight=2) + G.add_edge("Simplice", "Valjean", weight=3) + G.add_edge("Simplice", "Fantine", weight=2) + G.add_edge("Simplice", "Javert", weight=1) + G.add_edge("Scaufflaire", "Valjean", weight=1) + G.add_edge("Woman1", "Valjean", weight=2) + G.add_edge("Woman1", "Javert", weight=1) + G.add_edge("Judge", "Valjean", weight=3) + G.add_edge("Judge", "Bamatabois", weight=2) + G.add_edge("Champmathieu", "Valjean", weight=3) + G.add_edge("Champmathieu", "Judge", weight=3) + G.add_edge("Champmathieu", "Bamatabois", weight=2) + G.add_edge("Brevet", "Judge", weight=2) + G.add_edge("Brevet", "Champmathieu", weight=2) + G.add_edge("Brevet", "Valjean", weight=2) + G.add_edge("Brevet", "Bamatabois", weight=1) + G.add_edge("Chenildieu", "Judge", weight=2) + G.add_edge("Chenildieu", "Champmathieu", weight=2) + G.add_edge("Chenildieu", "Brevet", weight=2) + G.add_edge("Chenildieu", "Valjean", weight=2) + G.add_edge("Chenildieu", "Bamatabois", weight=1) + G.add_edge("Cochepaille", "Judge", weight=2) + G.add_edge("Cochepaille", "Champmathieu", weight=2) + G.add_edge("Cochepaille", "Brevet", weight=2) + G.add_edge("Cochepaille", "Chenildieu", weight=2) + G.add_edge("Cochepaille", "Valjean", weight=2) + G.add_edge("Cochepaille", "Bamatabois", weight=1) + G.add_edge("Pontmercy", "Thenardier", weight=1) + G.add_edge("Boulatruelle", "Thenardier", weight=1) + G.add_edge("Eponine", "MmeThenardier", weight=2) + G.add_edge("Eponine", "Thenardier", weight=3) + G.add_edge("Anzelma", "Eponine", weight=2) + G.add_edge("Anzelma", "Thenardier", weight=2) + G.add_edge("Anzelma", "MmeThenardier", weight=1) + G.add_edge("Woman2", "Valjean", weight=3) + G.add_edge("Woman2", "Cosette", weight=1) + G.add_edge("Woman2", "Javert", weight=1) + G.add_edge("MotherInnocent", "Fauchelevent", weight=3) + G.add_edge("MotherInnocent", "Valjean", weight=1) + G.add_edge("Gribier", "Fauchelevent", weight=2) + G.add_edge("MmeBurgon", "Jondrette", weight=1) + G.add_edge("Gavroche", "MmeBurgon", weight=2) + G.add_edge("Gavroche", "Thenardier", weight=1) + G.add_edge("Gavroche", "Javert", weight=1) + G.add_edge("Gavroche", "Valjean", weight=1) + G.add_edge("Gillenormand", "Cosette", weight=3) + G.add_edge("Gillenormand", "Valjean", weight=2) + G.add_edge("Magnon", "Gillenormand", weight=1) + G.add_edge("Magnon", "MmeThenardier", weight=1) + G.add_edge("MlleGillenormand", "Gillenormand", weight=9) + G.add_edge("MlleGillenormand", "Cosette", weight=2) + G.add_edge("MlleGillenormand", "Valjean", weight=2) + G.add_edge("MmePontmercy", "MlleGillenormand", weight=1) + G.add_edge("MmePontmercy", "Pontmercy", weight=1) + G.add_edge("MlleVaubois", "MlleGillenormand", weight=1) + G.add_edge("LtGillenormand", "MlleGillenormand", weight=2) + G.add_edge("LtGillenormand", "Gillenormand", weight=1) + G.add_edge("LtGillenormand", "Cosette", weight=1) + G.add_edge("Marius", "MlleGillenormand", weight=6) + G.add_edge("Marius", "Gillenormand", weight=12) + G.add_edge("Marius", "Pontmercy", weight=1) + G.add_edge("Marius", "LtGillenormand", weight=1) + G.add_edge("Marius", "Cosette", weight=21) + G.add_edge("Marius", "Valjean", weight=19) + G.add_edge("Marius", "Tholomyes", weight=1) + G.add_edge("Marius", "Thenardier", weight=2) + G.add_edge("Marius", "Eponine", weight=5) + G.add_edge("Marius", "Gavroche", weight=4) + G.add_edge("BaronessT", "Gillenormand", weight=1) + G.add_edge("BaronessT", "Marius", weight=1) + G.add_edge("Mabeuf", "Marius", weight=1) + G.add_edge("Mabeuf", "Eponine", weight=1) + G.add_edge("Mabeuf", "Gavroche", weight=1) + G.add_edge("Enjolras", "Marius", weight=7) + G.add_edge("Enjolras", "Gavroche", weight=7) + G.add_edge("Enjolras", "Javert", weight=6) + G.add_edge("Enjolras", "Mabeuf", weight=1) + G.add_edge("Enjolras", "Valjean", weight=4) + G.add_edge("Combeferre", "Enjolras", weight=15) + G.add_edge("Combeferre", "Marius", weight=5) + G.add_edge("Combeferre", "Gavroche", weight=6) + G.add_edge("Combeferre", "Mabeuf", weight=2) + G.add_edge("Prouvaire", "Gavroche", weight=1) + G.add_edge("Prouvaire", "Enjolras", weight=4) + G.add_edge("Prouvaire", "Combeferre", weight=2) + G.add_edge("Feuilly", "Gavroche", weight=2) + G.add_edge("Feuilly", "Enjolras", weight=6) + G.add_edge("Feuilly", "Prouvaire", weight=2) + G.add_edge("Feuilly", "Combeferre", weight=5) + G.add_edge("Feuilly", "Mabeuf", weight=1) + G.add_edge("Feuilly", "Marius", weight=1) + G.add_edge("Courfeyrac", "Marius", weight=9) + G.add_edge("Courfeyrac", "Enjolras", weight=17) + G.add_edge("Courfeyrac", "Combeferre", weight=13) + G.add_edge("Courfeyrac", "Gavroche", weight=7) + G.add_edge("Courfeyrac", "Mabeuf", weight=2) + G.add_edge("Courfeyrac", "Eponine", weight=1) + G.add_edge("Courfeyrac", "Feuilly", weight=6) + G.add_edge("Courfeyrac", "Prouvaire", weight=3) + G.add_edge("Bahorel", "Combeferre", weight=5) + G.add_edge("Bahorel", "Gavroche", weight=5) + G.add_edge("Bahorel", "Courfeyrac", weight=6) + G.add_edge("Bahorel", "Mabeuf", weight=2) + G.add_edge("Bahorel", "Enjolras", weight=4) + G.add_edge("Bahorel", "Feuilly", weight=3) + G.add_edge("Bahorel", "Prouvaire", weight=2) + G.add_edge("Bahorel", "Marius", weight=1) + G.add_edge("Bossuet", "Marius", weight=5) + G.add_edge("Bossuet", "Courfeyrac", weight=12) + G.add_edge("Bossuet", "Gavroche", weight=5) + G.add_edge("Bossuet", "Bahorel", weight=4) + G.add_edge("Bossuet", "Enjolras", weight=10) + G.add_edge("Bossuet", "Feuilly", weight=6) + G.add_edge("Bossuet", "Prouvaire", weight=2) + G.add_edge("Bossuet", "Combeferre", weight=9) + G.add_edge("Bossuet", "Mabeuf", weight=1) + G.add_edge("Bossuet", "Valjean", weight=1) + G.add_edge("Joly", "Bahorel", weight=5) + G.add_edge("Joly", "Bossuet", weight=7) + G.add_edge("Joly", "Gavroche", weight=3) + G.add_edge("Joly", "Courfeyrac", weight=5) + G.add_edge("Joly", "Enjolras", weight=5) + G.add_edge("Joly", "Feuilly", weight=5) + G.add_edge("Joly", "Prouvaire", weight=2) + G.add_edge("Joly", "Combeferre", weight=5) + G.add_edge("Joly", "Mabeuf", weight=1) + G.add_edge("Joly", "Marius", weight=2) + G.add_edge("Grantaire", "Bossuet", weight=3) + G.add_edge("Grantaire", "Enjolras", weight=3) + G.add_edge("Grantaire", "Combeferre", weight=1) + G.add_edge("Grantaire", "Courfeyrac", weight=2) + G.add_edge("Grantaire", "Joly", weight=2) + G.add_edge("Grantaire", "Gavroche", weight=1) + G.add_edge("Grantaire", "Bahorel", weight=1) + G.add_edge("Grantaire", "Feuilly", weight=1) + G.add_edge("Grantaire", "Prouvaire", weight=1) + G.add_edge("MotherPlutarch", "Mabeuf", weight=3) + G.add_edge("Gueulemer", "Thenardier", weight=5) + G.add_edge("Gueulemer", "Valjean", weight=1) + G.add_edge("Gueulemer", "MmeThenardier", weight=1) + G.add_edge("Gueulemer", "Javert", weight=1) + G.add_edge("Gueulemer", "Gavroche", weight=1) + G.add_edge("Gueulemer", "Eponine", weight=1) + G.add_edge("Babet", "Thenardier", weight=6) + G.add_edge("Babet", "Gueulemer", weight=6) + G.add_edge("Babet", "Valjean", weight=1) + G.add_edge("Babet", "MmeThenardier", weight=1) + G.add_edge("Babet", "Javert", weight=2) + G.add_edge("Babet", "Gavroche", weight=1) + G.add_edge("Babet", "Eponine", weight=1) + G.add_edge("Claquesous", "Thenardier", weight=4) + G.add_edge("Claquesous", "Babet", weight=4) + G.add_edge("Claquesous", "Gueulemer", weight=4) + G.add_edge("Claquesous", "Valjean", weight=1) + G.add_edge("Claquesous", "MmeThenardier", weight=1) + G.add_edge("Claquesous", "Javert", weight=1) + G.add_edge("Claquesous", "Eponine", weight=1) + G.add_edge("Claquesous", "Enjolras", weight=1) + G.add_edge("Montparnasse", "Javert", weight=1) + G.add_edge("Montparnasse", "Babet", weight=2) + G.add_edge("Montparnasse", "Gueulemer", weight=2) + G.add_edge("Montparnasse", "Claquesous", weight=2) + G.add_edge("Montparnasse", "Valjean", weight=1) + G.add_edge("Montparnasse", "Gavroche", weight=1) + G.add_edge("Montparnasse", "Eponine", weight=1) + G.add_edge("Montparnasse", "Thenardier", weight=1) + G.add_edge("Toussaint", "Cosette", weight=2) + G.add_edge("Toussaint", "Javert", weight=1) + G.add_edge("Toussaint", "Valjean", weight=1) + G.add_edge("Child1", "Gavroche", weight=2) + G.add_edge("Child2", "Gavroche", weight=2) + G.add_edge("Child2", "Child1", weight=3) + G.add_edge("Brujon", "Babet", weight=3) + G.add_edge("Brujon", "Gueulemer", weight=3) + G.add_edge("Brujon", "Thenardier", weight=3) + G.add_edge("Brujon", "Gavroche", weight=1) + G.add_edge("Brujon", "Eponine", weight=1) + G.add_edge("Brujon", "Claquesous", weight=1) + G.add_edge("Brujon", "Montparnasse", weight=1) + G.add_edge("MmeHucheloup", "Bossuet", weight=1) + G.add_edge("MmeHucheloup", "Joly", weight=1) + G.add_edge("MmeHucheloup", "Grantaire", weight=1) + G.add_edge("MmeHucheloup", "Bahorel", weight=1) + G.add_edge("MmeHucheloup", "Courfeyrac", weight=1) + G.add_edge("MmeHucheloup", "Gavroche", weight=1) + G.add_edge("MmeHucheloup", "Enjolras", weight=1) + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/stochastic.py b/janus/lib/python3.10/site-packages/networkx/generators/stochastic.py new file mode 100644 index 0000000000000000000000000000000000000000..f53e2315470f8ffcdea0380026a933e06ddf6ea7 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/stochastic.py @@ -0,0 +1,54 @@ +"""Functions for generating stochastic graphs from a given weighted directed +graph. + +""" + +import networkx as nx +from networkx.classes import DiGraph, MultiDiGraph +from networkx.utils import not_implemented_for + +__all__ = ["stochastic_graph"] + + +@not_implemented_for("undirected") +@nx._dispatchable( + edge_attrs="weight", mutates_input={"not copy": 1}, returns_graph=True +) +def stochastic_graph(G, copy=True, weight="weight"): + """Returns a right-stochastic representation of directed graph `G`. + + A right-stochastic graph is a weighted digraph in which for each + node, the sum of the weights of all the out-edges of that node is + 1. If the graph is already weighted (for example, via a 'weight' + edge attribute), the reweighting takes that into account. + + Parameters + ---------- + G : directed graph + A :class:`~networkx.DiGraph` or :class:`~networkx.MultiDiGraph`. + + copy : boolean, optional + If this is True, then this function returns a new graph with + the stochastic reweighting. Otherwise, the original graph is + modified in-place (and also returned, for convenience). + + weight : edge attribute key (optional, default='weight') + Edge attribute key used for reading the existing weight and + setting the new weight. If no attribute with this key is found + for an edge, then the edge weight is assumed to be 1. If an edge + has a weight, it must be a positive number. + + """ + if copy: + G = MultiDiGraph(G) if G.is_multigraph() else DiGraph(G) + # There is a tradeoff here: the dictionary of node degrees may + # require a lot of memory, whereas making a call to `G.out_degree` + # inside the loop may be costly in computation time. + degree = dict(G.out_degree(weight=weight)) + for u, v, d in G.edges(data=True): + if degree[u] == 0: + d[weight] = 0 + else: + d[weight] = d.get(weight, 1) / degree[u] + nx._clear_cache(G) + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/sudoku.py b/janus/lib/python3.10/site-packages/networkx/generators/sudoku.py new file mode 100644 index 0000000000000000000000000000000000000000..f288ed24d1f189588de7e1e0bba61f50bbad0003 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/sudoku.py @@ -0,0 +1,131 @@ +"""Generator for Sudoku graphs + +This module gives a generator for n-Sudoku graphs. It can be used to develop +algorithms for solving or generating Sudoku puzzles. + +A completed Sudoku grid is a 9x9 array of integers between 1 and 9, with no +number appearing twice in the same row, column, or 3x3 box. + ++---------+---------+---------+ +| | 8 6 4 | | 3 7 1 | | 2 5 9 | +| | 3 2 5 | | 8 4 9 | | 7 6 1 | +| | 9 7 1 | | 2 6 5 | | 8 4 3 | ++---------+---------+---------+ +| | 4 3 6 | | 1 9 2 | | 5 8 7 | +| | 1 9 8 | | 6 5 7 | | 4 3 2 | +| | 2 5 7 | | 4 8 3 | | 9 1 6 | ++---------+---------+---------+ +| | 6 8 9 | | 7 3 4 | | 1 2 5 | +| | 7 1 3 | | 5 2 8 | | 6 9 4 | +| | 5 4 2 | | 9 1 6 | | 3 7 8 | ++---------+---------+---------+ + + +The Sudoku graph is an undirected graph with 81 vertices, corresponding to +the cells of a Sudoku grid. It is a regular graph of degree 20. Two distinct +vertices are adjacent if and only if the corresponding cells belong to the +same row, column, or box. A completed Sudoku grid corresponds to a vertex +coloring of the Sudoku graph with nine colors. + +More generally, the n-Sudoku graph is a graph with n^4 vertices, corresponding +to the cells of an n^2 by n^2 grid. Two distinct vertices are adjacent if and +only if they belong to the same row, column, or n by n box. + +References +---------- +.. [1] Herzberg, A. M., & Murty, M. R. (2007). Sudoku squares and chromatic + polynomials. Notices of the AMS, 54(6), 708-717. +.. [2] Sander, Torsten (2009), "Sudoku graphs are integral", + Electronic Journal of Combinatorics, 16 (1): Note 25, 7pp, MR 2529816 +.. [3] Wikipedia contributors. "Glossary of Sudoku." Wikipedia, The Free + Encyclopedia, 3 Dec. 2019. Web. 22 Dec. 2019. +""" + +import networkx as nx +from networkx.exception import NetworkXError + +__all__ = ["sudoku_graph"] + + +@nx._dispatchable(graphs=None, returns_graph=True) +def sudoku_graph(n=3): + """Returns the n-Sudoku graph. The default value of n is 3. + + The n-Sudoku graph is a graph with n^4 vertices, corresponding to the + cells of an n^2 by n^2 grid. Two distinct vertices are adjacent if and + only if they belong to the same row, column, or n-by-n box. + + Parameters + ---------- + n: integer + The order of the Sudoku graph, equal to the square root of the + number of rows. The default is 3. + + Returns + ------- + NetworkX graph + The n-Sudoku graph Sud(n). + + Examples + -------- + >>> G = nx.sudoku_graph() + >>> G.number_of_nodes() + 81 + >>> G.number_of_edges() + 810 + >>> sorted(G.neighbors(42)) + [6, 15, 24, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 44, 51, 52, 53, 60, 69, 78] + >>> G = nx.sudoku_graph(2) + >>> G.number_of_nodes() + 16 + >>> G.number_of_edges() + 56 + + References + ---------- + .. [1] Herzberg, A. M., & Murty, M. R. (2007). Sudoku squares and chromatic + polynomials. Notices of the AMS, 54(6), 708-717. + .. [2] Sander, Torsten (2009), "Sudoku graphs are integral", + Electronic Journal of Combinatorics, 16 (1): Note 25, 7pp, MR 2529816 + .. [3] Wikipedia contributors. "Glossary of Sudoku." Wikipedia, The Free + Encyclopedia, 3 Dec. 2019. Web. 22 Dec. 2019. + """ + + if n < 0: + raise NetworkXError("The order must be greater than or equal to zero.") + + n2 = n * n + n3 = n2 * n + n4 = n3 * n + + # Construct an empty graph with n^4 nodes + G = nx.empty_graph(n4) + + # A Sudoku graph of order 0 or 1 has no edges + if n < 2: + return G + + # Add edges for cells in the same row + for row_no in range(n2): + row_start = row_no * n2 + for j in range(1, n2): + for i in range(j): + G.add_edge(row_start + i, row_start + j) + + # Add edges for cells in the same column + for col_no in range(n2): + for j in range(col_no, n4, n2): + for i in range(col_no, j, n2): + G.add_edge(i, j) + + # Add edges for cells in the same box + for band_no in range(n): + for stack_no in range(n): + box_start = n3 * band_no + n * stack_no + for j in range(1, n2): + for i in range(j): + u = box_start + (i % n) + n2 * (i // n) + v = box_start + (j % n) + n2 * (j // n) + G.add_edge(u, v) + + return G diff --git 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b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_cographs.py @@ -0,0 +1,18 @@ +"""Unit tests for the :mod:`networkx.generators.cographs` module.""" + +import networkx as nx + + +def test_random_cograph(): + n = 3 + G = nx.random_cograph(n) + + assert len(G) == 2**n + + # Every connected subgraph of G has diameter <= 2 + if nx.is_connected(G): + assert nx.diameter(G) <= 2 + else: + components = nx.connected_components(G) + for component in components: + assert nx.diameter(G.subgraph(component)) <= 2 diff --git a/janus/lib/python3.10/site-packages/networkx/generators/tests/test_duplication.py b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_duplication.py new file mode 100644 index 0000000000000000000000000000000000000000..9b6100b78e59067b607e310f14d80e5a00c2b691 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_duplication.py @@ -0,0 +1,103 @@ +"""Unit tests for the :mod:`networkx.generators.duplication` module.""" + +import pytest + +import networkx as nx + + +class TestDuplicationDivergenceGraph: + """Unit tests for the + :func:`networkx.generators.duplication.duplication_divergence_graph` + function. + + """ + + def test_final_size(self): + G = nx.duplication_divergence_graph(3, p=1) + assert len(G) == 3 + G = nx.duplication_divergence_graph(3, p=1, seed=42) + assert len(G) == 3 + + def test_probability_too_large(self): + with pytest.raises(nx.NetworkXError): + nx.duplication_divergence_graph(3, p=2) + + def test_probability_too_small(self): + with pytest.raises(nx.NetworkXError): + nx.duplication_divergence_graph(3, p=-1) + + def test_non_extreme_probability_value(self): + G = nx.duplication_divergence_graph(6, p=0.3, seed=42) + assert len(G) == 6 + assert list(G.degree()) == [(0, 2), (1, 3), (2, 2), (3, 3), (4, 1), (5, 1)] + + def test_minimum_desired_nodes(self): + with pytest.raises( + nx.NetworkXError, match=".*n must be greater than or equal to 2" + ): + nx.duplication_divergence_graph(1, p=1) + + def test_create_using(self): + class DummyGraph(nx.Graph): + pass + + class DummyDiGraph(nx.DiGraph): + pass + + G = nx.duplication_divergence_graph(6, 0.3, seed=42, create_using=DummyGraph) + assert isinstance(G, DummyGraph) + with pytest.raises(nx.NetworkXError, match="create_using must not be directed"): + nx.duplication_divergence_graph(6, 0.3, seed=42, create_using=DummyDiGraph) + + +class TestPartialDuplicationGraph: + """Unit tests for the + :func:`networkx.generators.duplication.partial_duplication_graph` + function. + + """ + + def test_final_size(self): + N = 10 + n = 5 + p = 0.5 + q = 0.5 + G = nx.partial_duplication_graph(N, n, p, q) + assert len(G) == N + G = nx.partial_duplication_graph(N, n, p, q, seed=42) + assert len(G) == N + + def test_initial_clique_size(self): + N = 10 + n = 10 + p = 0.5 + q = 0.5 + G = nx.partial_duplication_graph(N, n, p, q) + assert len(G) == n + + def test_invalid_initial_size(self): + with pytest.raises(nx.NetworkXError): + N = 5 + n = 10 + p = 0.5 + q = 0.5 + G = nx.partial_duplication_graph(N, n, p, q) + + def test_invalid_probabilities(self): + N = 1 + n = 1 + for p, q in [(0.5, 2), (0.5, -1), (2, 0.5), (-1, 0.5)]: + args = (N, n, p, q) + pytest.raises(nx.NetworkXError, nx.partial_duplication_graph, *args) + + def test_create_using(self): + class DummyGraph(nx.Graph): + pass + + class DummyDiGraph(nx.DiGraph): + pass + + G = nx.partial_duplication_graph(10, 5, 0.5, 0.5, create_using=DummyGraph) + assert isinstance(G, DummyGraph) + with pytest.raises(nx.NetworkXError, match="create_using must not be directed"): + nx.partial_duplication_graph(10, 5, 0.5, 0.5, create_using=DummyDiGraph) diff --git a/janus/lib/python3.10/site-packages/networkx/generators/tests/test_expanders.py b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_expanders.py new file mode 100644 index 0000000000000000000000000000000000000000..7cebc588197fec0d12a958457ef5a0e5b80bf9d4 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_expanders.py @@ -0,0 +1,162 @@ +"""Unit tests for the :mod:`networkx.generators.expanders` module.""" + +import pytest + +import networkx as nx + + +@pytest.mark.parametrize("n", (2, 3, 5, 6, 10)) +def test_margulis_gabber_galil_graph_properties(n): + g = nx.margulis_gabber_galil_graph(n) + assert g.number_of_nodes() == n * n + for node in g: + assert g.degree(node) == 8 + assert len(node) == 2 + for i in node: + assert int(i) == i + assert 0 <= i < n + + +@pytest.mark.parametrize("n", (2, 3, 5, 6, 10)) +def test_margulis_gabber_galil_graph_eigvals(n): + np = pytest.importorskip("numpy") + sp = pytest.importorskip("scipy") + + g = nx.margulis_gabber_galil_graph(n) + # Eigenvalues are already sorted using the scipy eigvalsh, + # but the implementation in numpy does not guarantee order. + w = sorted(sp.linalg.eigvalsh(nx.adjacency_matrix(g).toarray())) + assert w[-2] < 5 * np.sqrt(2) + + +@pytest.mark.parametrize("p", (3, 5, 7, 11)) # Primes +def test_chordal_cycle_graph(p): + """Test for the :func:`networkx.chordal_cycle_graph` function.""" + G = nx.chordal_cycle_graph(p) + assert len(G) == p + # TODO The second largest eigenvalue should be smaller than a constant, + # independent of the number of nodes in the graph: + # + # eigs = sorted(sp.linalg.eigvalsh(nx.adjacency_matrix(G).toarray())) + # assert_less(eigs[-2], ...) + # + + +@pytest.mark.parametrize("p", (3, 5, 7, 11, 13)) # Primes +def test_paley_graph(p): + """Test for the :func:`networkx.paley_graph` function.""" + G = nx.paley_graph(p) + # G has p nodes + assert len(G) == p + # G is (p-1)/2-regular + in_degrees = {G.in_degree(node) for node in G.nodes} + out_degrees = {G.out_degree(node) for node in G.nodes} + assert len(in_degrees) == 1 and in_degrees.pop() == (p - 1) // 2 + assert len(out_degrees) == 1 and out_degrees.pop() == (p - 1) // 2 + + # If p = 1 mod 4, -1 is a square mod 4 and therefore the + # edge in the Paley graph are symmetric. + if p % 4 == 1: + for u, v in G.edges: + assert (v, u) in G.edges + + +@pytest.mark.parametrize("d, n", [(2, 7), (4, 10), (4, 16)]) +def test_maybe_regular_expander(d, n): + pytest.importorskip("numpy") + G = nx.maybe_regular_expander(n, d) + + assert len(G) == n, "Should have n nodes" + assert len(G.edges) == n * d / 2, "Should have n*d/2 edges" + assert nx.is_k_regular(G, d), "Should be d-regular" + + +@pytest.mark.parametrize("n", (3, 5, 6, 10)) +def test_is_regular_expander(n): + pytest.importorskip("numpy") + pytest.importorskip("scipy") + G = nx.complete_graph(n) + + assert nx.is_regular_expander(G) == True, "Should be a regular expander" + + +@pytest.mark.parametrize("d, n", [(2, 7), (4, 10), (4, 16)]) +def test_random_regular_expander(d, n): + pytest.importorskip("numpy") + pytest.importorskip("scipy") + G = nx.random_regular_expander_graph(n, d) + + assert len(G) == n, "Should have n nodes" + assert len(G.edges) == n * d / 2, "Should have n*d/2 edges" + assert nx.is_k_regular(G, d), "Should be d-regular" + assert nx.is_regular_expander(G) == True, "Should be a regular expander" + + +def test_random_regular_expander_explicit_construction(): + pytest.importorskip("numpy") + pytest.importorskip("scipy") + G = nx.random_regular_expander_graph(d=4, n=5) + + assert len(G) == 5 and len(G.edges) == 10, "Should be a complete graph" + + +@pytest.mark.parametrize("graph_type", (nx.Graph, nx.DiGraph, nx.MultiDiGraph)) +def test_margulis_gabber_galil_graph_badinput(graph_type): + with pytest.raises( + nx.NetworkXError, match="`create_using` must be an undirected multigraph" + ): + nx.margulis_gabber_galil_graph(3, create_using=graph_type) + + +@pytest.mark.parametrize("graph_type", (nx.Graph, nx.DiGraph, nx.MultiDiGraph)) +def test_chordal_cycle_graph_badinput(graph_type): + with pytest.raises( + nx.NetworkXError, match="`create_using` must be an undirected multigraph" + ): + nx.chordal_cycle_graph(3, create_using=graph_type) + + +def test_paley_graph_badinput(): + with pytest.raises( + nx.NetworkXError, match="`create_using` cannot be a multigraph." + ): + nx.paley_graph(3, create_using=nx.MultiGraph) + + +def test_maybe_regular_expander_badinput(): + pytest.importorskip("numpy") + pytest.importorskip("scipy") + + with pytest.raises(nx.NetworkXError, match="n must be a positive integer"): + nx.maybe_regular_expander(n=-1, d=2) + + with pytest.raises(nx.NetworkXError, match="d must be greater than or equal to 2"): + nx.maybe_regular_expander(n=10, d=0) + + with pytest.raises(nx.NetworkXError, match="Need n-1>= d to have room"): + nx.maybe_regular_expander(n=5, d=6) + + +def test_is_regular_expander_badinput(): + pytest.importorskip("numpy") + pytest.importorskip("scipy") + + with pytest.raises(nx.NetworkXError, match="epsilon must be non negative"): + nx.is_regular_expander(nx.Graph(), epsilon=-1) + + +def test_random_regular_expander_badinput(): + pytest.importorskip("numpy") + pytest.importorskip("scipy") + + with pytest.raises(nx.NetworkXError, match="n must be a positive integer"): + nx.random_regular_expander_graph(n=-1, d=2) + + with pytest.raises(nx.NetworkXError, match="d must be greater than or equal to 2"): + nx.random_regular_expander_graph(n=10, d=0) + + with pytest.raises(nx.NetworkXError, match="Need n-1>= d to have room"): + nx.random_regular_expander_graph(n=5, d=6) + + with pytest.raises(nx.NetworkXError, match="epsilon must be non negative"): + nx.random_regular_expander_graph(n=4, d=2, epsilon=-1) diff --git a/janus/lib/python3.10/site-packages/networkx/generators/tests/test_geometric.py b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_geometric.py new file mode 100644 index 0000000000000000000000000000000000000000..f1c68bead51b75e7a39484164cc484cbd4e5def8 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_geometric.py @@ -0,0 +1,488 @@ +import math +import random +from itertools import combinations + +import pytest + +import networkx as nx + + +def l1dist(x, y): + return sum(abs(a - b) for a, b in zip(x, y)) + + +class TestRandomGeometricGraph: + """Unit tests for :func:`~networkx.random_geometric_graph`""" + + def test_number_of_nodes(self): + G = nx.random_geometric_graph(50, 0.25, seed=42) + assert len(G) == 50 + G = nx.random_geometric_graph(range(50), 0.25, seed=42) + assert len(G) == 50 + + def test_distances(self): + """Tests that pairs of vertices adjacent if and only if they are + within the prescribed radius. + """ + # Use the Euclidean metric, the default according to the + # documentation. + G = nx.random_geometric_graph(50, 0.25) + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + # Nonadjacent vertices must be at greater distance. + else: + assert not math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_p(self): + """Tests for providing an alternate distance metric to the generator.""" + # Use the L1 metric. + G = nx.random_geometric_graph(50, 0.25, p=1) + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert l1dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + # Nonadjacent vertices must be at greater distance. + else: + assert not l1dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_node_names(self): + """Tests using values other than sequential numbers as node IDs.""" + import string + + nodes = list(string.ascii_lowercase) + G = nx.random_geometric_graph(nodes, 0.25) + assert len(G) == len(nodes) + + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + # Nonadjacent vertices must be at greater distance. + else: + assert not math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_pos_name(self): + G = nx.random_geometric_graph(50, 0.25, seed=42, pos_name="coords") + assert all(len(d["coords"]) == 2 for n, d in G.nodes.items()) + + +class TestSoftRandomGeometricGraph: + """Unit tests for :func:`~networkx.soft_random_geometric_graph`""" + + def test_number_of_nodes(self): + G = nx.soft_random_geometric_graph(50, 0.25, seed=42) + assert len(G) == 50 + G = nx.soft_random_geometric_graph(range(50), 0.25, seed=42) + assert len(G) == 50 + + def test_distances(self): + """Tests that pairs of vertices adjacent if and only if they are + within the prescribed radius. + """ + # Use the Euclidean metric, the default according to the + # documentation. + G = nx.soft_random_geometric_graph(50, 0.25) + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_p(self): + """Tests for providing an alternate distance metric to the generator.""" + + # Use the L1 metric. + def dist(x, y): + return sum(abs(a - b) for a, b in zip(x, y)) + + G = nx.soft_random_geometric_graph(50, 0.25, p=1) + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_node_names(self): + """Tests using values other than sequential numbers as node IDs.""" + import string + + nodes = list(string.ascii_lowercase) + G = nx.soft_random_geometric_graph(nodes, 0.25) + assert len(G) == len(nodes) + + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_p_dist_default(self): + """Tests default p_dict = 0.5 returns graph with edge count <= RGG with + same n, radius, dim and positions + """ + nodes = 50 + dim = 2 + pos = {v: [random.random() for i in range(dim)] for v in range(nodes)} + RGG = nx.random_geometric_graph(50, 0.25, pos=pos) + SRGG = nx.soft_random_geometric_graph(50, 0.25, pos=pos) + assert len(SRGG.edges()) <= len(RGG.edges()) + + def test_p_dist_zero(self): + """Tests if p_dict = 0 returns disconnected graph with 0 edges""" + + def p_dist(dist): + return 0 + + G = nx.soft_random_geometric_graph(50, 0.25, p_dist=p_dist) + assert len(G.edges) == 0 + + def test_pos_name(self): + G = nx.soft_random_geometric_graph(50, 0.25, seed=42, pos_name="coords") + assert all(len(d["coords"]) == 2 for n, d in G.nodes.items()) + + +def join(G, u, v, theta, alpha, metric): + """Returns ``True`` if and only if the nodes whose attributes are + ``du`` and ``dv`` should be joined, according to the threshold + condition for geographical threshold graphs. + + ``G`` is an undirected NetworkX graph, and ``u`` and ``v`` are nodes + in that graph. The nodes must have node attributes ``'pos'`` and + ``'weight'``. + + ``metric`` is a distance metric. + """ + du, dv = G.nodes[u], G.nodes[v] + u_pos, v_pos = du["pos"], dv["pos"] + u_weight, v_weight = du["weight"], dv["weight"] + return (u_weight + v_weight) * metric(u_pos, v_pos) ** alpha >= theta + + +class TestGeographicalThresholdGraph: + """Unit tests for :func:`~networkx.geographical_threshold_graph`""" + + def test_number_of_nodes(self): + G = nx.geographical_threshold_graph(50, 100, seed=42) + assert len(G) == 50 + G = nx.geographical_threshold_graph(range(50), 100, seed=42) + assert len(G) == 50 + + def test_distances(self): + """Tests that pairs of vertices adjacent if and only if their + distances meet the given threshold. + """ + # Use the Euclidean metric and alpha = -2 + # the default according to the documentation. + G = nx.geographical_threshold_graph(50, 10) + for u, v in combinations(G, 2): + # Adjacent vertices must exceed the threshold. + if v in G[u]: + assert join(G, u, v, 10, -2, math.dist) + # Nonadjacent vertices must not exceed the threshold. + else: + assert not join(G, u, v, 10, -2, math.dist) + + def test_metric(self): + """Tests for providing an alternate distance metric to the generator.""" + # Use the L1 metric. + G = nx.geographical_threshold_graph(50, 10, metric=l1dist) + for u, v in combinations(G, 2): + # Adjacent vertices must exceed the threshold. + if v in G[u]: + assert join(G, u, v, 10, -2, l1dist) + # Nonadjacent vertices must not exceed the threshold. + else: + assert not join(G, u, v, 10, -2, l1dist) + + def test_p_dist_zero(self): + """Tests if p_dict = 0 returns disconnected graph with 0 edges""" + + def p_dist(dist): + return 0 + + G = nx.geographical_threshold_graph(50, 1, p_dist=p_dist) + assert len(G.edges) == 0 + + def test_pos_weight_name(self): + gtg = nx.geographical_threshold_graph + G = gtg(50, 100, seed=42, pos_name="coords", weight_name="wt") + assert all(len(d["coords"]) == 2 for n, d in G.nodes.items()) + assert all(d["wt"] > 0 for n, d in G.nodes.items()) + + +class TestWaxmanGraph: + """Unit tests for the :func:`~networkx.waxman_graph` function.""" + + def test_number_of_nodes_1(self): + G = nx.waxman_graph(50, 0.5, 0.1, seed=42) + assert len(G) == 50 + G = nx.waxman_graph(range(50), 0.5, 0.1, seed=42) + assert len(G) == 50 + + def test_number_of_nodes_2(self): + G = nx.waxman_graph(50, 0.5, 0.1, L=1) + assert len(G) == 50 + G = nx.waxman_graph(range(50), 0.5, 0.1, L=1) + assert len(G) == 50 + + def test_metric(self): + """Tests for providing an alternate distance metric to the generator.""" + # Use the L1 metric. + G = nx.waxman_graph(50, 0.5, 0.1, metric=l1dist) + assert len(G) == 50 + + def test_pos_name(self): + G = nx.waxman_graph(50, 0.5, 0.1, seed=42, pos_name="coords") + assert all(len(d["coords"]) == 2 for n, d in G.nodes.items()) + + +class TestNavigableSmallWorldGraph: + def test_navigable_small_world(self): + G = nx.navigable_small_world_graph(5, p=1, q=0, seed=42) + gg = nx.grid_2d_graph(5, 5).to_directed() + assert nx.is_isomorphic(G, gg) + + G = nx.navigable_small_world_graph(5, p=1, q=0, dim=3) + gg = nx.grid_graph([5, 5, 5]).to_directed() + assert nx.is_isomorphic(G, gg) + + G = nx.navigable_small_world_graph(5, p=1, q=0, dim=1) + gg = nx.grid_graph([5]).to_directed() + assert nx.is_isomorphic(G, gg) + + def test_invalid_diameter_value(self): + with pytest.raises(nx.NetworkXException, match=".*p must be >= 1"): + nx.navigable_small_world_graph(5, p=0, q=0, dim=1) + + def test_invalid_long_range_connections_value(self): + with pytest.raises(nx.NetworkXException, match=".*q must be >= 0"): + nx.navigable_small_world_graph(5, p=1, q=-1, dim=1) + + def test_invalid_exponent_for_decaying_probability_value(self): + with pytest.raises(nx.NetworkXException, match=".*r must be >= 0"): + nx.navigable_small_world_graph(5, p=1, q=0, r=-1, dim=1) + + def test_r_between_0_and_1(self): + """Smoke test for radius in range [0, 1]""" + # q=0 means no long-range connections + G = nx.navigable_small_world_graph(3, p=1, q=0, r=0.5, dim=2, seed=42) + expected = nx.grid_2d_graph(3, 3, create_using=nx.DiGraph) + assert nx.utils.graphs_equal(G, expected) + + @pytest.mark.parametrize("seed", range(2478, 2578, 10)) + def test_r_general_scaling(self, seed): + """The probability of adding a long-range edge scales with `1 / dist**r`, + so a navigable_small_world graph created with r < 1 should generally + result in more edges than a navigable_small_world graph with r >= 1 + (for 0 < q << n). + + N.B. this is probabilistic, so this test may not hold for all seeds.""" + G1 = nx.navigable_small_world_graph(7, q=3, r=0.5, seed=seed) + G2 = nx.navigable_small_world_graph(7, q=3, r=1, seed=seed) + G3 = nx.navigable_small_world_graph(7, q=3, r=2, seed=seed) + assert G1.number_of_edges() > G2.number_of_edges() + assert G2.number_of_edges() > G3.number_of_edges() + + +class TestThresholdedRandomGeometricGraph: + """Unit tests for :func:`~networkx.thresholded_random_geometric_graph`""" + + def test_number_of_nodes(self): + G = nx.thresholded_random_geometric_graph(50, 0.2, 0.1, seed=42) + assert len(G) == 50 + G = nx.thresholded_random_geometric_graph(range(50), 0.2, 0.1, seed=42) + assert len(G) == 50 + + def test_distances(self): + """Tests that pairs of vertices adjacent if and only if they are + within the prescribed radius. + """ + # Use the Euclidean metric, the default according to the + # documentation. + G = nx.thresholded_random_geometric_graph(50, 0.25, 0.1, seed=42) + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_p(self): + """Tests for providing an alternate distance metric to the generator.""" + + # Use the L1 metric. + def dist(x, y): + return sum(abs(a - b) for a, b in zip(x, y)) + + G = nx.thresholded_random_geometric_graph(50, 0.25, 0.1, p=1, seed=42) + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_node_names(self): + """Tests using values other than sequential numbers as node IDs.""" + import string + + nodes = list(string.ascii_lowercase) + G = nx.thresholded_random_geometric_graph(nodes, 0.25, 0.1, seed=42) + assert len(G) == len(nodes) + + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert math.dist(G.nodes[u]["pos"], G.nodes[v]["pos"]) <= 0.25 + + def test_theta(self): + """Tests that pairs of vertices adjacent if and only if their sum + weights exceeds the threshold parameter theta. + """ + G = nx.thresholded_random_geometric_graph(50, 0.25, 0.1, seed=42) + + for u, v in combinations(G, 2): + # Adjacent vertices must be within the given distance. + if v in G[u]: + assert (G.nodes[u]["weight"] + G.nodes[v]["weight"]) >= 0.1 + + def test_pos_name(self): + trgg = nx.thresholded_random_geometric_graph + G = trgg(50, 0.25, 0.1, seed=42, pos_name="p", weight_name="wt") + assert all(len(d["p"]) == 2 for n, d in G.nodes.items()) + assert all(d["wt"] > 0 for n, d in G.nodes.items()) + + +def test_geometric_edges_pos_attribute(): + G = nx.Graph() + G.add_nodes_from( + [ + (0, {"position": (0, 0)}), + (1, {"position": (0, 1)}), + (2, {"position": (1, 0)}), + ] + ) + expected_edges = [(0, 1), (0, 2)] + assert expected_edges == nx.geometric_edges(G, radius=1, pos_name="position") + + +def test_geometric_edges_raises_no_pos(): + G = nx.path_graph(3) + msg = "all nodes. must have a '" + with pytest.raises(nx.NetworkXError, match=msg): + nx.geometric_edges(G, radius=1) + + +def test_number_of_nodes_S1(): + G = nx.geometric_soft_configuration_graph( + beta=1.5, n=100, gamma=2.7, mean_degree=10, seed=42 + ) + assert len(G) == 100 + + +def test_set_attributes_S1(): + G = nx.geometric_soft_configuration_graph( + beta=1.5, n=100, gamma=2.7, mean_degree=10, seed=42 + ) + kappas = nx.get_node_attributes(G, "kappa") + assert len(kappas) == 100 + thetas = nx.get_node_attributes(G, "theta") + assert len(thetas) == 100 + radii = nx.get_node_attributes(G, "radius") + assert len(radii) == 100 + + +def test_mean_kappas_mean_degree_S1(): + G = nx.geometric_soft_configuration_graph( + beta=2.5, n=50, gamma=2.7, mean_degree=10, seed=8023 + ) + + kappas = nx.get_node_attributes(G, "kappa") + mean_kappas = sum(kappas.values()) / len(kappas) + assert math.fabs(mean_kappas - 10) < 0.5 + + degrees = dict(G.degree()) + mean_degree = sum(degrees.values()) / len(degrees) + assert math.fabs(mean_degree - 10) < 1 + + +def test_dict_kappas_S1(): + kappas = {i: 10 for i in range(1000)} + G = nx.geometric_soft_configuration_graph(beta=1, kappas=kappas) + assert len(G) == 1000 + kappas = nx.get_node_attributes(G, "kappa") + assert all(kappa == 10 for kappa in kappas.values()) + + +def test_beta_clustering_S1(): + G1 = nx.geometric_soft_configuration_graph( + beta=1.5, n=100, gamma=3.5, mean_degree=10, seed=42 + ) + G2 = nx.geometric_soft_configuration_graph( + beta=3.0, n=100, gamma=3.5, mean_degree=10, seed=42 + ) + assert nx.average_clustering(G1) < nx.average_clustering(G2) + + +def test_wrong_parameters_S1(): + with pytest.raises( + nx.NetworkXError, + match="Please provide either kappas, or all 3 of: n, gamma and mean_degree.", + ): + G = nx.geometric_soft_configuration_graph( + beta=1.5, gamma=3.5, mean_degree=10, seed=42 + ) + + with pytest.raises( + nx.NetworkXError, + match="When kappas is input, n, gamma and mean_degree must not be.", + ): + kappas = {i: 10 for i in range(1000)} + G = nx.geometric_soft_configuration_graph( + beta=1.5, kappas=kappas, gamma=2.3, seed=42 + ) + + with pytest.raises( + nx.NetworkXError, + match="Please provide either kappas, or all 3 of: n, gamma and mean_degree.", + ): + G = nx.geometric_soft_configuration_graph(beta=1.5, seed=42) + + +def test_negative_beta_S1(): + with pytest.raises( + nx.NetworkXError, match="The parameter beta cannot be smaller or equal to 0." + ): + G = nx.geometric_soft_configuration_graph( + beta=-1, n=100, gamma=2.3, mean_degree=10, seed=42 + ) + + +def test_non_zero_clustering_beta_lower_one_S1(): + G = nx.geometric_soft_configuration_graph( + beta=0.5, n=100, gamma=3.5, mean_degree=10, seed=42 + ) + assert nx.average_clustering(G) > 0 + + +def test_mean_degree_influence_on_connectivity_S1(): + low_mean_degree = 2 + high_mean_degree = 20 + G_low = nx.geometric_soft_configuration_graph( + beta=1.2, n=100, gamma=2.7, mean_degree=low_mean_degree, seed=42 + ) + G_high = nx.geometric_soft_configuration_graph( + beta=1.2, n=100, gamma=2.7, mean_degree=high_mean_degree, seed=42 + ) + assert nx.number_connected_components(G_low) > nx.number_connected_components( + G_high + ) + + +def test_compare_mean_kappas_different_gammas_S1(): + G1 = nx.geometric_soft_configuration_graph( + beta=1.5, n=20, gamma=2.7, mean_degree=5, seed=42 + ) + G2 = nx.geometric_soft_configuration_graph( + beta=1.5, n=20, gamma=3.5, mean_degree=5, seed=42 + ) + kappas1 = nx.get_node_attributes(G1, "kappa") + mean_kappas1 = sum(kappas1.values()) / len(kappas1) + kappas2 = nx.get_node_attributes(G2, "kappa") + mean_kappas2 = sum(kappas2.values()) / len(kappas2) + assert math.fabs(mean_kappas1 - mean_kappas2) < 1 diff --git a/janus/lib/python3.10/site-packages/networkx/generators/tests/test_harary_graph.py b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_harary_graph.py new file mode 100644 index 0000000000000000000000000000000000000000..8a0142df2a4340bc81d7dc25f05ea5d57e8f2d16 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_harary_graph.py @@ -0,0 +1,133 @@ +"""Unit tests for the :mod:`networkx.generators.harary_graph` module.""" + +import pytest + +import networkx as nx +from networkx.algorithms.isomorphism.isomorph import is_isomorphic +from networkx.generators.harary_graph import hkn_harary_graph, hnm_harary_graph + + +class TestHararyGraph: + """ + Suppose n nodes, m >= n-1 edges, d = 2m // n, r = 2m % n + """ + + def test_hnm_harary_graph(self): + # When d is even and r = 0, the hnm_harary_graph(n,m) is + # the circulant_graph(n, list(range(1,d/2+1))) + for n, m in [(5, 5), (6, 12), (7, 14)]: + G1 = hnm_harary_graph(n, m) + d = 2 * m // n + G2 = nx.circulant_graph(n, list(range(1, d // 2 + 1))) + assert is_isomorphic(G1, G2) + + # When d is even and r > 0, the hnm_harary_graph(n,m) is + # the circulant_graph(n, list(range(1,d/2+1))) + # with r edges added arbitrarily + for n, m in [(5, 7), (6, 13), (7, 16)]: + G1 = hnm_harary_graph(n, m) + d = 2 * m // n + G2 = nx.circulant_graph(n, list(range(1, d // 2 + 1))) + assert set(G2.edges) < set(G1.edges) + assert G1.number_of_edges() == m + + # When d is odd and n is even and r = 0, the hnm_harary_graph(n,m) + # is the circulant_graph(n, list(range(1,(d+1)/2) plus [n//2]) + for n, m in [(6, 9), (8, 12), (10, 15)]: + G1 = hnm_harary_graph(n, m) + d = 2 * m // n + L = list(range(1, (d + 1) // 2)) + L.append(n // 2) + G2 = nx.circulant_graph(n, L) + assert is_isomorphic(G1, G2) + + # When d is odd and n is even and r > 0, the hnm_harary_graph(n,m) + # is the circulant_graph(n, list(range(1,(d+1)/2) plus [n//2]) + # with r edges added arbitrarily + for n, m in [(6, 10), (8, 13), (10, 17)]: + G1 = hnm_harary_graph(n, m) + d = 2 * m // n + L = list(range(1, (d + 1) // 2)) + L.append(n // 2) + G2 = nx.circulant_graph(n, L) + assert set(G2.edges) < set(G1.edges) + assert G1.number_of_edges() == m + + # When d is odd and n is odd, the hnm_harary_graph(n,m) is + # the circulant_graph(n, list(range(1,(d+1)/2)) + # with m - n*(d-1)/2 edges added arbitrarily + for n, m in [(5, 4), (7, 12), (9, 14)]: + G1 = hnm_harary_graph(n, m) + d = 2 * m // n + L = list(range(1, (d + 1) // 2)) + G2 = nx.circulant_graph(n, L) + assert set(G2.edges) < set(G1.edges) + assert G1.number_of_edges() == m + + # Raise NetworkXError if n<1 + n = 0 + m = 0 + pytest.raises(nx.NetworkXError, hnm_harary_graph, n, m) + + # Raise NetworkXError if m < n-1 + n = 6 + m = 4 + pytest.raises(nx.NetworkXError, hnm_harary_graph, n, m) + + # Raise NetworkXError if m > n(n-1)/2 + n = 6 + m = 16 + pytest.raises(nx.NetworkXError, hnm_harary_graph, n, m) + + """ + Suppose connectivity k, number of nodes n + """ + + def test_hkn_harary_graph(self): + # When k == 1, the hkn_harary_graph(k,n) is + # the path_graph(n) + for k, n in [(1, 6), (1, 7)]: + G1 = hkn_harary_graph(k, n) + G2 = nx.path_graph(n) + assert is_isomorphic(G1, G2) + + # When k is even, the hkn_harary_graph(k,n) is + # the circulant_graph(n, list(range(1,k/2+1))) + for k, n in [(2, 6), (2, 7), (4, 6), (4, 7)]: + G1 = hkn_harary_graph(k, n) + G2 = nx.circulant_graph(n, list(range(1, k // 2 + 1))) + assert is_isomorphic(G1, G2) + + # When k is odd and n is even, the hkn_harary_graph(k,n) is + # the circulant_graph(n, list(range(1,(k+1)/2)) plus [n/2]) + for k, n in [(3, 6), (5, 8), (7, 10)]: + G1 = hkn_harary_graph(k, n) + L = list(range(1, (k + 1) // 2)) + L.append(n // 2) + G2 = nx.circulant_graph(n, L) + assert is_isomorphic(G1, G2) + + # When k is odd and n is odd, the hkn_harary_graph(k,n) is + # the circulant_graph(n, list(range(1,(k+1)/2))) with + # n//2+1 edges added between node i and node i+n//2+1 + for k, n in [(3, 5), (5, 9), (7, 11)]: + G1 = hkn_harary_graph(k, n) + G2 = nx.circulant_graph(n, list(range(1, (k + 1) // 2))) + eSet1 = set(G1.edges) + eSet2 = set(G2.edges) + eSet3 = set() + half = n // 2 + for i in range(half + 1): + # add half+1 edges between i and i+half + eSet3.add((i, (i + half) % n)) + assert eSet1 == eSet2 | eSet3 + + # Raise NetworkXError if k<1 + k = 0 + n = 0 + pytest.raises(nx.NetworkXError, hkn_harary_graph, k, n) + + # Raise NetworkXError if n. + strings = ["a", "to", "tea", "ted", "ten", "i", "in", "inn"] + T = prefix_tree_fn(strings) + root, NIL = 0, -1 + + def source_label(v): + return T.nodes[v]["source"] + + # First, we check that the tree has the expected + # structure. Recall that each node that corresponds to one of + # the input strings has an edge to the NIL node. + # + # Consider the three children at level 1 in the trie. + a, i, t = sorted(T[root], key=source_label) + # Check the 'a' branch. + assert len(T[a]) == 1 + nil = arbitrary_element(T[a]) + assert len(T[nil]) == 0 + # Check the 'i' branch. + assert len(T[i]) == 2 + nil, in_ = sorted(T[i], key=source_label) + assert len(T[nil]) == 0 + assert len(T[in_]) == 2 + nil, inn = sorted(T[in_], key=source_label) + assert len(T[nil]) == 0 + assert len(T[inn]) == 1 + nil = arbitrary_element(T[inn]) + assert len(T[nil]) == 0 + # Check the 't' branch. + te, to = sorted(T[t], key=source_label) + assert len(T[to]) == 1 + nil = arbitrary_element(T[to]) + assert len(T[nil]) == 0 + tea, ted, ten = sorted(T[te], key=source_label) + assert len(T[tea]) == 1 + assert len(T[ted]) == 1 + assert len(T[ten]) == 1 + nil = arbitrary_element(T[tea]) + assert len(T[nil]) == 0 + nil = arbitrary_element(T[ted]) + assert len(T[nil]) == 0 + nil = arbitrary_element(T[ten]) + assert len(T[nil]) == 0 + + # Next, we check that the "sources" of each of the nodes is the + # rightmost letter in the string corresponding to the path to + # that node. + assert source_label(root) is None + assert source_label(a) == "a" + assert source_label(i) == "i" + assert source_label(t) == "t" + assert source_label(in_) == "n" + assert source_label(inn) == "n" + assert source_label(to) == "o" + assert source_label(te) == "e" + assert source_label(tea) == "a" + assert source_label(ted) == "d" + assert source_label(ten) == "n" + assert source_label(NIL) == "NIL" + + +@pytest.mark.parametrize( + "strings", + ( + ["a", "to", "tea", "ted", "ten", "i", "in", "inn"], + ["ab", "abs", "ad"], + ["ab", "abs", "ad", ""], + ["distant", "disparaging", "distant", "diamond", "ruby"], + ), +) +def test_implementations_consistent(strings): + """Ensure results are consistent between prefix_tree implementations.""" + assert graphs_equal(nx.prefix_tree(strings), nx.prefix_tree_recursive(strings)) + + +def test_random_labeled_rooted_tree(): + for i in range(1, 10): + t1 = nx.random_labeled_rooted_tree(i, seed=42) + t2 = nx.random_labeled_rooted_tree(i, seed=42) + assert nx.utils.misc.graphs_equal(t1, t2) + assert nx.is_tree(t1) + assert "root" in t1.graph + assert "roots" not in t1.graph + + +def test_random_labeled_tree_n_zero(): + """Tests if n = 0 then the NetworkXPointlessConcept exception is raised.""" + with pytest.raises(nx.NetworkXPointlessConcept): + T = nx.random_labeled_tree(0, seed=1234) + with pytest.raises(nx.NetworkXPointlessConcept): + T = nx.random_labeled_rooted_tree(0, seed=1234) + + +def test_random_labeled_rooted_forest(): + for i in range(1, 10): + t1 = nx.random_labeled_rooted_forest(i, seed=42) + t2 = nx.random_labeled_rooted_forest(i, seed=42) + assert nx.utils.misc.graphs_equal(t1, t2) + for c in nx.connected_components(t1): + assert nx.is_tree(t1.subgraph(c)) + assert "root" not in t1.graph + assert "roots" in t1.graph + + +def test_random_labeled_rooted_forest_n_zero(): + """Tests generation of empty labeled forests.""" + F = nx.random_labeled_rooted_forest(0, seed=1234) + assert len(F) == 0 + assert len(F.graph["roots"]) == 0 + + +def test_random_unlabeled_rooted_tree(): + for i in range(1, 10): + t1 = nx.random_unlabeled_rooted_tree(i, seed=42) + t2 = nx.random_unlabeled_rooted_tree(i, seed=42) + assert nx.utils.misc.graphs_equal(t1, t2) + assert nx.is_tree(t1) + assert "root" in t1.graph + assert "roots" not in t1.graph + t = nx.random_unlabeled_rooted_tree(15, number_of_trees=10, seed=43) + random.seed(43) + s = nx.random_unlabeled_rooted_tree(15, number_of_trees=10, seed=random) + for i in range(10): + assert nx.utils.misc.graphs_equal(t[i], s[i]) + assert nx.is_tree(t[i]) + assert "root" in t[i].graph + assert "roots" not in t[i].graph + + +def test_random_unlabeled_tree_n_zero(): + """Tests if n = 0 then the NetworkXPointlessConcept exception is raised.""" + with pytest.raises(nx.NetworkXPointlessConcept): + T = nx.random_unlabeled_tree(0, seed=1234) + with pytest.raises(nx.NetworkXPointlessConcept): + T = nx.random_unlabeled_rooted_tree(0, seed=1234) + + +def test_random_unlabeled_rooted_forest(): + with pytest.raises(ValueError): + nx.random_unlabeled_rooted_forest(10, q=0, seed=42) + for i in range(1, 10): + for q in range(1, i + 1): + t1 = nx.random_unlabeled_rooted_forest(i, q=q, seed=42) + t2 = nx.random_unlabeled_rooted_forest(i, q=q, seed=42) + assert nx.utils.misc.graphs_equal(t1, t2) + for c in nx.connected_components(t1): + assert nx.is_tree(t1.subgraph(c)) + assert len(c) <= q + assert "root" not in t1.graph + assert "roots" in t1.graph + t = nx.random_unlabeled_rooted_forest(15, number_of_forests=10, seed=43) + random.seed(43) + s = nx.random_unlabeled_rooted_forest(15, number_of_forests=10, seed=random) + for i in range(10): + assert nx.utils.misc.graphs_equal(t[i], s[i]) + for c in nx.connected_components(t[i]): + assert nx.is_tree(t[i].subgraph(c)) + assert "root" not in t[i].graph + assert "roots" in t[i].graph + + +def test_random_unlabeled_forest_n_zero(): + """Tests generation of empty unlabeled forests.""" + F = nx.random_unlabeled_rooted_forest(0, seed=1234) + assert len(F) == 0 + assert len(F.graph["roots"]) == 0 + + +def test_random_unlabeled_tree(): + for i in range(1, 10): + t1 = nx.random_unlabeled_tree(i, seed=42) + t2 = nx.random_unlabeled_tree(i, seed=42) + assert nx.utils.misc.graphs_equal(t1, t2) + assert nx.is_tree(t1) + assert "root" not in t1.graph + assert "roots" not in t1.graph + t = nx.random_unlabeled_tree(10, number_of_trees=10, seed=43) + random.seed(43) + s = nx.random_unlabeled_tree(10, number_of_trees=10, seed=random) + for i in range(10): + assert nx.utils.misc.graphs_equal(t[i], s[i]) + assert nx.is_tree(t[i]) + assert "root" not in t[i].graph + assert "roots" not in t[i].graph diff --git a/janus/lib/python3.10/site-packages/networkx/generators/tests/test_triads.py b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_triads.py new file mode 100644 index 0000000000000000000000000000000000000000..463844be23a07f71375873bbc71e09c402d51118 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/tests/test_triads.py @@ -0,0 +1,15 @@ +"""Unit tests for the :mod:`networkx.generators.triads` module.""" + +import pytest + +from networkx import triad_graph + + +def test_triad_graph(): + G = triad_graph("030T") + assert [tuple(e) for e in ("ab", "ac", "cb")] == sorted(G.edges()) + + +def test_invalid_name(): + with pytest.raises(ValueError): + triad_graph("bogus") diff --git a/janus/lib/python3.10/site-packages/networkx/generators/time_series.py b/janus/lib/python3.10/site-packages/networkx/generators/time_series.py new file mode 100644 index 0000000000000000000000000000000000000000..592d7734a408bf33e58aad20cb117be674558ad2 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/time_series.py @@ -0,0 +1,74 @@ +""" +Time Series Graphs +""" + +import itertools + +import networkx as nx + +__all__ = ["visibility_graph"] + + +@nx._dispatchable(graphs=None, returns_graph=True) +def visibility_graph(series): + """ + Return a Visibility Graph of an input Time Series. + + A visibility graph converts a time series into a graph. The constructed graph + uses integer nodes to indicate which event in the series the node represents. + Edges are formed as follows: consider a bar plot of the series and view that + as a side view of a landscape with a node at the top of each bar. An edge + means that the nodes can be connected by a straight "line-of-sight" without + being obscured by any bars between the nodes. + + The resulting graph inherits several properties of the series in its structure. + Thereby, periodic series convert into regular graphs, random series convert + into random graphs, and fractal series convert into scale-free networks [1]_. + + Parameters + ---------- + series : Sequence[Number] + A Time Series sequence (iterable and sliceable) of numeric values + representing times. + + Returns + ------- + NetworkX Graph + The Visibility Graph of the input series + + Examples + -------- + >>> series_list = [range(10), [2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3]] + >>> for s in series_list: + ... g = nx.visibility_graph(s) + ... print(g) + Graph with 10 nodes and 9 edges + Graph with 12 nodes and 18 edges + + References + ---------- + .. [1] Lacasa, Lucas, Bartolo Luque, Fernando Ballesteros, Jordi Luque, and Juan Carlos Nuno. + "From time series to complex networks: The visibility graph." Proceedings of the + National Academy of Sciences 105, no. 13 (2008): 4972-4975. + https://www.pnas.org/doi/10.1073/pnas.0709247105 + """ + + # Sequential values are always connected + G = nx.path_graph(len(series)) + nx.set_node_attributes(G, dict(enumerate(series)), "value") + + # Check all combinations of nodes n series + for (n1, t1), (n2, t2) in itertools.combinations(enumerate(series), 2): + # check if any value between obstructs line of sight + slope = (t2 - t1) / (n2 - n1) + offset = t2 - slope * n2 + + obstructed = any( + t >= slope * n + offset + for n, t in enumerate(series[n1 + 1 : n2], start=n1 + 1) + ) + + if not obstructed: + G.add_edge(n1, n2) + + return G diff --git a/janus/lib/python3.10/site-packages/networkx/generators/trees.py b/janus/lib/python3.10/site-packages/networkx/generators/trees.py new file mode 100644 index 0000000000000000000000000000000000000000..30849a8d4884603b766fc7954cc310afe7338fa2 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/generators/trees.py @@ -0,0 +1,1071 @@ +"""Functions for generating trees. + +The functions sampling trees at random in this module come +in two variants: labeled and unlabeled. The labeled variants +sample from every possible tree with the given number of nodes +uniformly at random. The unlabeled variants sample from every +possible *isomorphism class* of trees with the given number +of nodes uniformly at random. + +To understand the difference, consider the following example. +There are two isomorphism classes of trees with four nodes. +One is that of the path graph, the other is that of the +star graph. The unlabeled variant will return a line graph or +a star graph with probability 1/2. + +The labeled variant will return the line graph +with probability 3/4 and the star graph with probability 1/4, +because there are more labeled variants of the line graph +than of the star graph. More precisely, the line graph has +an automorphism group of order 2, whereas the star graph has +an automorphism group of order 6, so the line graph has three +times as many labeled variants as the star graph, and thus +three more chances to be drawn. + +Additionally, some functions in this module can sample rooted +trees and forests uniformly at random. A rooted tree is a tree +with a designated root node. A rooted forest is a disjoint union +of rooted trees. +""" + +import warnings +from collections import Counter, defaultdict +from math import comb, factorial + +import networkx as nx +from networkx.utils import py_random_state + +__all__ = [ + "prefix_tree", + "prefix_tree_recursive", + "random_labeled_tree", + "random_labeled_rooted_tree", + "random_labeled_rooted_forest", + "random_unlabeled_tree", + "random_unlabeled_rooted_tree", + "random_unlabeled_rooted_forest", +] + + +@nx._dispatchable(graphs=None, returns_graph=True) +def prefix_tree(paths): + """Creates a directed prefix tree from a list of paths. + + Usually the paths are described as strings or lists of integers. + + A "prefix tree" represents the prefix structure of the strings. + Each node represents a prefix of some string. The root represents + the empty prefix with children for the single letter prefixes which + in turn have children for each double letter prefix starting with + the single letter corresponding to the parent node, and so on. + + More generally the prefixes do not need to be strings. A prefix refers + to the start of a sequence. The root has children for each one element + prefix and they have children for each two element prefix that starts + with the one element sequence of the parent, and so on. + + Note that this implementation uses integer nodes with an attribute. + Each node has an attribute "source" whose value is the original element + of the path to which this node corresponds. For example, suppose `paths` + consists of one path: "can". Then the nodes `[1, 2, 3]` which represent + this path have "source" values "c", "a" and "n". + + All the descendants of a node have a common prefix in the sequence/path + associated with that node. From the returned tree, the prefix for each + node can be constructed by traversing the tree up to the root and + accumulating the "source" values along the way. + + The root node is always `0` and has "source" attribute `None`. + The root is the only node with in-degree zero. + The nil node is always `-1` and has "source" attribute `"NIL"`. + The nil node is the only node with out-degree zero. + + + Parameters + ---------- + paths: iterable of paths + An iterable of paths which are themselves sequences. + Matching prefixes among these sequences are identified with + nodes of the prefix tree. One leaf of the tree is associated + with each path. (Identical paths are associated with the same + leaf of the tree.) + + + Returns + ------- + tree: DiGraph + A directed graph representing an arborescence consisting of the + prefix tree generated by `paths`. Nodes are directed "downward", + from parent to child. A special "synthetic" root node is added + to be the parent of the first node in each path. A special + "synthetic" leaf node, the "nil" node `-1`, is added to be the child + of all nodes representing the last element in a path. (The + addition of this nil node technically makes this not an + arborescence but a directed acyclic graph; removing the nil node + makes it an arborescence.) + + + Notes + ----- + The prefix tree is also known as a *trie*. + + + Examples + -------- + Create a prefix tree from a list of strings with common prefixes:: + + >>> paths = ["ab", "abs", "ad"] + >>> T = nx.prefix_tree(paths) + >>> list(T.edges) + [(0, 1), (1, 2), (1, 4), (2, -1), (2, 3), (3, -1), (4, -1)] + + The leaf nodes can be obtained as predecessors of the nil node:: + + >>> root, NIL = 0, -1 + >>> list(T.predecessors(NIL)) + [2, 3, 4] + + To recover the original paths that generated the prefix tree, + traverse up the tree from the node `-1` to the node `0`:: + + >>> recovered = [] + >>> for v in T.predecessors(NIL): + ... prefix = "" + ... while v != root: + ... prefix = str(T.nodes[v]["source"]) + prefix + ... v = next(T.predecessors(v)) # only one predecessor + ... recovered.append(prefix) + >>> sorted(recovered) + ['ab', 'abs', 'ad'] + """ + + def get_children(parent, paths): + children = defaultdict(list) + # Populate dictionary with key(s) as the child/children of the root and + # value(s) as the remaining paths of the corresponding child/children + for path in paths: + # If path is empty, we add an edge to the NIL node. + if not path: + tree.add_edge(parent, NIL) + continue + child, *rest = path + # `child` may exist as the head of more than one path in `paths`. + children[child].append(rest) + return children + + # Initialize the prefix tree with a root node and a nil node. + tree = nx.DiGraph() + root = 0 + tree.add_node(root, source=None) + NIL = -1 + tree.add_node(NIL, source="NIL") + children = get_children(root, paths) + stack = [(root, iter(children.items()))] + while stack: + parent, remaining_children = stack[-1] + try: + child, remaining_paths = next(remaining_children) + # Pop item off stack if there are no remaining children + except StopIteration: + stack.pop() + continue + # We relabel each child with an unused name. + new_name = len(tree) - 1 + # The "source" node attribute stores the original node name. + tree.add_node(new_name, source=child) + tree.add_edge(parent, new_name) + children = get_children(new_name, remaining_paths) + stack.append((new_name, iter(children.items()))) + + return tree + + +@nx._dispatchable(graphs=None, returns_graph=True) +def prefix_tree_recursive(paths): + """Recursively creates a directed prefix tree from a list of paths. + + The original recursive version of prefix_tree for comparison. It is + the same algorithm but the recursion is unrolled onto a stack. + + Usually the paths are described as strings or lists of integers. + + A "prefix tree" represents the prefix structure of the strings. + Each node represents a prefix of some string. The root represents + the empty prefix with children for the single letter prefixes which + in turn have children for each double letter prefix starting with + the single letter corresponding to the parent node, and so on. + + More generally the prefixes do not need to be strings. A prefix refers + to the start of a sequence. The root has children for each one element + prefix and they have children for each two element prefix that starts + with the one element sequence of the parent, and so on. + + Note that this implementation uses integer nodes with an attribute. + Each node has an attribute "source" whose value is the original element + of the path to which this node corresponds. For example, suppose `paths` + consists of one path: "can". Then the nodes `[1, 2, 3]` which represent + this path have "source" values "c", "a" and "n". + + All the descendants of a node have a common prefix in the sequence/path + associated with that node. From the returned tree, ehe prefix for each + node can be constructed by traversing the tree up to the root and + accumulating the "source" values along the way. + + The root node is always `0` and has "source" attribute `None`. + The root is the only node with in-degree zero. + The nil node is always `-1` and has "source" attribute `"NIL"`. + The nil node is the only node with out-degree zero. + + + Parameters + ---------- + paths: iterable of paths + An iterable of paths which are themselves sequences. + Matching prefixes among these sequences are identified with + nodes of the prefix tree. One leaf of the tree is associated + with each path. (Identical paths are associated with the same + leaf of the tree.) + + + Returns + ------- + tree: DiGraph + A directed graph representing an arborescence consisting of the + prefix tree generated by `paths`. Nodes are directed "downward", + from parent to child. A special "synthetic" root node is added + to be the parent of the first node in each path. A special + "synthetic" leaf node, the "nil" node `-1`, is added to be the child + of all nodes representing the last element in a path. (The + addition of this nil node technically makes this not an + arborescence but a directed acyclic graph; removing the nil node + makes it an arborescence.) + + + Notes + ----- + The prefix tree is also known as a *trie*. + + + Examples + -------- + Create a prefix tree from a list of strings with common prefixes:: + + >>> paths = ["ab", "abs", "ad"] + >>> T = nx.prefix_tree(paths) + >>> list(T.edges) + [(0, 1), (1, 2), (1, 4), (2, -1), (2, 3), (3, -1), (4, -1)] + + The leaf nodes can be obtained as predecessors of the nil node. + + >>> root, NIL = 0, -1 + >>> list(T.predecessors(NIL)) + [2, 3, 4] + + To recover the original paths that generated the prefix tree, + traverse up the tree from the node `-1` to the node `0`:: + + >>> recovered = [] + >>> for v in T.predecessors(NIL): + ... prefix = "" + ... while v != root: + ... prefix = str(T.nodes[v]["source"]) + prefix + ... v = next(T.predecessors(v)) # only one predecessor + ... recovered.append(prefix) + >>> sorted(recovered) + ['ab', 'abs', 'ad'] + """ + + def _helper(paths, root, tree): + """Recursively create a trie from the given list of paths. + + `paths` is a list of paths, each of which is itself a list of + nodes, relative to the given `root` (but not including it). This + list of paths will be interpreted as a tree-like structure, in + which two paths that share a prefix represent two branches of + the tree with the same initial segment. + + `root` is the parent of the node at index 0 in each path. + + `tree` is the "accumulator", the :class:`networkx.DiGraph` + representing the branching to which the new nodes and edges will + be added. + + """ + # For each path, remove the first node and make it a child of root. + # Any remaining paths then get processed recursively. + children = defaultdict(list) + for path in paths: + # If path is empty, we add an edge to the NIL node. + if not path: + tree.add_edge(root, NIL) + continue + child, *rest = path + # `child` may exist as the head of more than one path in `paths`. + children[child].append(rest) + # Add a node for each child, connect root, recurse to remaining paths + for child, remaining_paths in children.items(): + # We relabel each child with an unused name. + new_name = len(tree) - 1 + # The "source" node attribute stores the original node name. + tree.add_node(new_name, source=child) + tree.add_edge(root, new_name) + _helper(remaining_paths, new_name, tree) + + # Initialize the prefix tree with a root node and a nil node. + tree = nx.DiGraph() + root = 0 + tree.add_node(root, source=None) + NIL = -1 + tree.add_node(NIL, source="NIL") + # Populate the tree. + _helper(paths, root, tree) + return tree + + +@py_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_labeled_tree(n, *, seed=None): + """Returns a labeled tree on `n` nodes chosen uniformly at random. + + Generating uniformly distributed random Prüfer sequences and + converting them into the corresponding trees is a straightforward + method of generating uniformly distributed random labeled trees. + This function implements this method. + + Parameters + ---------- + n : int + The number of nodes, greater than zero. + seed : random_state + Indicator of random number generation state. + See :ref:`Randomness` + + Returns + ------- + :class:`networkx.Graph` + A `networkx.Graph` with nodes in the set {0, …, *n* - 1}. + + Raises + ------ + NetworkXPointlessConcept + If `n` is zero (because the null graph is not a tree). + + Examples + -------- + >>> G = nx.random_labeled_tree(5, seed=42) + >>> nx.is_tree(G) + True + >>> G.edges + EdgeView([(0, 1), (0, 3), (0, 2), (2, 4)]) + + A tree with *arbitrarily directed* edges can be created by assigning + generated edges to a ``DiGraph``: + + >>> DG = nx.DiGraph() + >>> DG.add_edges_from(G.edges) + >>> nx.is_tree(DG) + True + >>> DG.edges + OutEdgeView([(0, 1), (0, 3), (0, 2), (2, 4)]) + """ + # Cannot create a Prüfer sequence unless `n` is at least two. + if n == 0: + raise nx.NetworkXPointlessConcept("the null graph is not a tree") + if n == 1: + return nx.empty_graph(1) + return nx.from_prufer_sequence([seed.choice(range(n)) for i in range(n - 2)]) + + +@py_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_labeled_rooted_tree(n, *, seed=None): + """Returns a labeled rooted tree with `n` nodes. + + The returned tree is chosen uniformly at random from all labeled rooted trees. + + Parameters + ---------- + n : int + The number of nodes + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + :class:`networkx.Graph` + A `networkx.Graph` with integer nodes 0 <= node <= `n` - 1. + The root of the tree is selected uniformly from the nodes. + The "root" graph attribute identifies the root of the tree. + + Notes + ----- + This function returns the result of :func:`random_labeled_tree` + with a randomly selected root. + + Raises + ------ + NetworkXPointlessConcept + If `n` is zero (because the null graph is not a tree). + """ + t = random_labeled_tree(n, seed=seed) + t.graph["root"] = seed.randint(0, n - 1) + return t + + +@py_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_labeled_rooted_forest(n, *, seed=None): + """Returns a labeled rooted forest with `n` nodes. + + The returned forest is chosen uniformly at random using a + generalization of Prüfer sequences [1]_ in the form described in [2]_. + + Parameters + ---------- + n : int + The number of nodes. + seed : random_state + See :ref:`Randomness`. + + Returns + ------- + :class:`networkx.Graph` + A `networkx.Graph` with integer nodes 0 <= node <= `n` - 1. + The "roots" graph attribute is a set of integers containing the roots. + + References + ---------- + .. [1] Knuth, Donald E. "Another Enumeration of Trees." + Canadian Journal of Mathematics, 20 (1968): 1077-1086. + https://doi.org/10.4153/CJM-1968-104-8 + .. [2] Rubey, Martin. "Counting Spanning Trees". Diplomarbeit + zur Erlangung des akademischen Grades Magister der + Naturwissenschaften an der Formal- und Naturwissenschaftlichen + Fakultät der Universität Wien. Wien, May 2000. + """ + + # Select the number of roots by iterating over the cumulative count of trees + # with at most k roots + def _select_k(n, seed): + r = seed.randint(0, (n + 1) ** (n - 1) - 1) + cum_sum = 0 + for k in range(1, n): + cum_sum += (factorial(n - 1) * n ** (n - k)) // ( + factorial(k - 1) * factorial(n - k) + ) + if r < cum_sum: + return k + + return n + + F = nx.empty_graph(n) + if n == 0: + F.graph["roots"] = {} + return F + # Select the number of roots k + k = _select_k(n, seed) + if k == n: + F.graph["roots"] = set(range(n)) + return F # Nothing to do + # Select the roots + roots = seed.sample(range(n), k) + # Nonroots + p = set(range(n)).difference(roots) + # Coding sequence + N = [seed.randint(0, n - 1) for i in range(n - k - 1)] + # Multiset of elements in N also in p + degree = Counter([x for x in N if x in p]) + # Iterator over the elements of p with degree zero + iterator = iter(x for x in p if degree[x] == 0) + u = last = next(iterator) + # This loop is identical to that for Prüfer sequences, + # except that we can draw nodes only from p + for v in N: + F.add_edge(u, v) + degree[v] -= 1 + if v < last and degree[v] == 0: + u = v + else: + last = u = next(iterator) + + F.add_edge(u, roots[0]) + F.graph["roots"] = set(roots) + return F + + +# The following functions support generation of unlabeled trees and forests. + + +def _to_nx(edges, n_nodes, root=None, roots=None): + """ + Converts the (edges, n_nodes) input to a :class:`networkx.Graph`. + The (edges, n_nodes) input is a list of even length, where each pair + of consecutive integers represents an edge, and an integer `n_nodes`. + Integers in the list are elements of `range(n_nodes)`. + + Parameters + ---------- + edges : list of ints + The flattened list of edges of the graph. + n_nodes : int + The number of nodes of the graph. + root: int (default=None) + If not None, the "root" attribute of the graph will be set to this value. + roots: collection of ints (default=None) + If not None, he "roots" attribute of the graph will be set to this value. + + Returns + ------- + :class:`networkx.Graph` + The graph with `n_nodes` nodes and edges given by `edges`. + """ + G = nx.empty_graph(n_nodes) + G.add_edges_from(edges) + if root is not None: + G.graph["root"] = root + if roots is not None: + G.graph["roots"] = roots + return G + + +def _num_rooted_trees(n, cache_trees): + """Returns the number of unlabeled rooted trees with `n` nodes. + + See also https://oeis.org/A000081. + + Parameters + ---------- + n : int + The number of nodes + cache_trees : list of ints + The $i$-th element is the number of unlabeled rooted trees with $i$ nodes, + which is used as a cache (and is extended to length $n+1$ if needed) + + Returns + ------- + int + The number of unlabeled rooted trees with `n` nodes. + """ + for n_i in range(len(cache_trees), n + 1): + cache_trees.append( + sum( + [ + d * cache_trees[n_i - j * d] * cache_trees[d] + for d in range(1, n_i) + for j in range(1, (n_i - 1) // d + 1) + ] + ) + // (n_i - 1) + ) + return cache_trees[n] + + +def _select_jd_trees(n, cache_trees, seed): + """Returns a pair $(j,d)$ with a specific probability + + Given $n$, returns a pair of positive integers $(j,d)$ with the probability + specified in formula (5) of Chapter 29 of [1]_. + + Parameters + ---------- + n : int + The number of nodes + cache_trees : list of ints + Cache for :func:`_num_rooted_trees`. + seed : random_state + See :ref:`Randomness`. + + Returns + ------- + (int, int) + A pair of positive integers $(j,d)$ satisfying formula (5) of + Chapter 29 of [1]_. + + References + ---------- + .. [1] Nijenhuis, Albert, and Wilf, Herbert S. + "Combinatorial algorithms: for computers and calculators." + Academic Press, 1978. + https://doi.org/10.1016/C2013-0-11243-3 + """ + p = seed.randint(0, _num_rooted_trees(n, cache_trees) * (n - 1) - 1) + cumsum = 0 + for d in range(n - 1, 0, -1): + for j in range(1, (n - 1) // d + 1): + cumsum += ( + d + * _num_rooted_trees(n - j * d, cache_trees) + * _num_rooted_trees(d, cache_trees) + ) + if p < cumsum: + return (j, d) + + +def _random_unlabeled_rooted_tree(n, cache_trees, seed): + """Returns an unlabeled rooted tree with `n` nodes. + + Returns an unlabeled rooted tree with `n` nodes chosen uniformly + at random using the "RANRUT" algorithm from [1]_. + The tree is returned in the form: (list_of_edges, number_of_nodes) + + Parameters + ---------- + n : int + The number of nodes, greater than zero. + cache_trees : list ints + Cache for :func:`_num_rooted_trees`. + seed : random_state + See :ref:`Randomness`. + + Returns + ------- + (list_of_edges, number_of_nodes) : list, int + A random unlabeled rooted tree with `n` nodes as a 2-tuple + ``(list_of_edges, number_of_nodes)``. + The root is node 0. + + References + ---------- + .. [1] Nijenhuis, Albert, and Wilf, Herbert S. + "Combinatorial algorithms: for computers and calculators." + Academic Press, 1978. + https://doi.org/10.1016/C2013-0-11243-3 + """ + if n == 1: + edges, n_nodes = [], 1 + return edges, n_nodes + if n == 2: + edges, n_nodes = [(0, 1)], 2 + return edges, n_nodes + + j, d = _select_jd_trees(n, cache_trees, seed) + t1, t1_nodes = _random_unlabeled_rooted_tree(n - j * d, cache_trees, seed) + t2, t2_nodes = _random_unlabeled_rooted_tree(d, cache_trees, seed) + t12 = [(0, t2_nodes * i + t1_nodes) for i in range(j)] + t1.extend(t12) + for _ in range(j): + t1.extend((n1 + t1_nodes, n2 + t1_nodes) for n1, n2 in t2) + t1_nodes += t2_nodes + + return t1, t1_nodes + + +@py_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_unlabeled_rooted_tree(n, *, number_of_trees=None, seed=None): + """Returns a number of unlabeled rooted trees uniformly at random + + Returns one or more (depending on `number_of_trees`) + unlabeled rooted trees with `n` nodes drawn uniformly + at random. + + Parameters + ---------- + n : int + The number of nodes + number_of_trees : int or None (default) + If not None, this number of trees is generated and returned. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + :class:`networkx.Graph` or list of :class:`networkx.Graph` + A single `networkx.Graph` (or a list thereof, if `number_of_trees` + is specified) with nodes in the set {0, …, *n* - 1}. + The "root" graph attribute identifies the root of the tree. + + Notes + ----- + The trees are generated using the "RANRUT" algorithm from [1]_. + The algorithm needs to compute some counting functions + that are relatively expensive: in case several trees are needed, + it is advisable to use the `number_of_trees` optional argument + to reuse the counting functions. + + Raises + ------ + NetworkXPointlessConcept + If `n` is zero (because the null graph is not a tree). + + References + ---------- + .. [1] Nijenhuis, Albert, and Wilf, Herbert S. + "Combinatorial algorithms: for computers and calculators." + Academic Press, 1978. + https://doi.org/10.1016/C2013-0-11243-3 + """ + if n == 0: + raise nx.NetworkXPointlessConcept("the null graph is not a tree") + cache_trees = [0, 1] # initial cache of number of rooted trees + if number_of_trees is None: + return _to_nx(*_random_unlabeled_rooted_tree(n, cache_trees, seed), root=0) + return [ + _to_nx(*_random_unlabeled_rooted_tree(n, cache_trees, seed), root=0) + for i in range(number_of_trees) + ] + + +def _num_rooted_forests(n, q, cache_forests): + """Returns the number of unlabeled rooted forests with `n` nodes, and with + no more than `q` nodes per tree. A recursive formula for this is (2) in + [1]_. This function is implemented using dynamic programming instead of + recursion. + + Parameters + ---------- + n : int + The number of nodes. + q : int + The maximum number of nodes for each tree of the forest. + cache_forests : list of ints + The $i$-th element is the number of unlabeled rooted forests with + $i$ nodes, and with no more than `q` nodes per tree; this is used + as a cache (and is extended to length `n` + 1 if needed). + + Returns + ------- + int + The number of unlabeled rooted forests with `n` nodes with no more than + `q` nodes per tree. + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + for n_i in range(len(cache_forests), n + 1): + q_i = min(n_i, q) + cache_forests.append( + sum( + [ + d * cache_forests[n_i - j * d] * cache_forests[d - 1] + for d in range(1, q_i + 1) + for j in range(1, n_i // d + 1) + ] + ) + // n_i + ) + + return cache_forests[n] + + +def _select_jd_forests(n, q, cache_forests, seed): + """Given `n` and `q`, returns a pair of positive integers $(j,d)$ + such that $j\\leq d$, with probability satisfying (F1) of [1]_. + + Parameters + ---------- + n : int + The number of nodes. + q : int + The maximum number of nodes for each tree of the forest. + cache_forests : list of ints + Cache for :func:`_num_rooted_forests`. + seed : random_state + See :ref:`Randomness`. + + Returns + ------- + (int, int) + A pair of positive integers $(j,d)$ + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + p = seed.randint(0, _num_rooted_forests(n, q, cache_forests) * n - 1) + cumsum = 0 + for d in range(q, 0, -1): + for j in range(1, n // d + 1): + cumsum += ( + d + * _num_rooted_forests(n - j * d, q, cache_forests) + * _num_rooted_forests(d - 1, q, cache_forests) + ) + if p < cumsum: + return (j, d) + + +def _random_unlabeled_rooted_forest(n, q, cache_trees, cache_forests, seed): + """Returns an unlabeled rooted forest with `n` nodes, and with no more + than `q` nodes per tree, drawn uniformly at random. It is an implementation + of the algorithm "Forest" of [1]_. + + Parameters + ---------- + n : int + The number of nodes. + q : int + The maximum number of nodes per tree. + cache_trees : + Cache for :func:`_num_rooted_trees`. + cache_forests : + Cache for :func:`_num_rooted_forests`. + seed : random_state + See :ref:`Randomness`. + + Returns + ------- + (edges, n, r) : (list, int, list) + The forest (edges, n) and a list r of root nodes. + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + if n == 0: + return ([], 0, []) + + j, d = _select_jd_forests(n, q, cache_forests, seed) + t1, t1_nodes, r1 = _random_unlabeled_rooted_forest( + n - j * d, q, cache_trees, cache_forests, seed + ) + t2, t2_nodes = _random_unlabeled_rooted_tree(d, cache_trees, seed) + for _ in range(j): + r1.append(t1_nodes) + t1.extend((n1 + t1_nodes, n2 + t1_nodes) for n1, n2 in t2) + t1_nodes += t2_nodes + return t1, t1_nodes, r1 + + +@py_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_unlabeled_rooted_forest(n, *, q=None, number_of_forests=None, seed=None): + """Returns a forest or list of forests selected at random. + + Returns one or more (depending on `number_of_forests`) + unlabeled rooted forests with `n` nodes, and with no more than + `q` nodes per tree, drawn uniformly at random. + The "roots" graph attribute identifies the roots of the forest. + + Parameters + ---------- + n : int + The number of nodes + q : int or None (default) + The maximum number of nodes per tree. + number_of_forests : int or None (default) + If not None, this number of forests is generated and returned. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + :class:`networkx.Graph` or list of :class:`networkx.Graph` + A single `networkx.Graph` (or a list thereof, if `number_of_forests` + is specified) with nodes in the set {0, …, *n* - 1}. + The "roots" graph attribute is a set containing the roots + of the trees in the forest. + + Notes + ----- + This function implements the algorithm "Forest" of [1]_. + The algorithm needs to compute some counting functions + that are relatively expensive: in case several trees are needed, + it is advisable to use the `number_of_forests` optional argument + to reuse the counting functions. + + Raises + ------ + ValueError + If `n` is non-zero but `q` is zero. + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + if q is None: + q = n + if q == 0 and n != 0: + raise ValueError("q must be a positive integer if n is positive.") + + cache_trees = [0, 1] # initial cache of number of rooted trees + cache_forests = [1] # initial cache of number of rooted forests + + if number_of_forests is None: + g, nodes, rs = _random_unlabeled_rooted_forest( + n, q, cache_trees, cache_forests, seed + ) + return _to_nx(g, nodes, roots=set(rs)) + + res = [] + for i in range(number_of_forests): + g, nodes, rs = _random_unlabeled_rooted_forest( + n, q, cache_trees, cache_forests, seed + ) + res.append(_to_nx(g, nodes, roots=set(rs))) + return res + + +def _num_trees(n, cache_trees): + """Returns the number of unlabeled trees with `n` nodes. + + See also https://oeis.org/A000055. + + Parameters + ---------- + n : int + The number of nodes. + cache_trees : list of ints + Cache for :func:`_num_rooted_trees`. + + Returns + ------- + int + The number of unlabeled trees with `n` nodes. + """ + r = _num_rooted_trees(n, cache_trees) - sum( + [ + _num_rooted_trees(j, cache_trees) * _num_rooted_trees(n - j, cache_trees) + for j in range(1, n // 2 + 1) + ] + ) + if n % 2 == 0: + r += comb(_num_rooted_trees(n // 2, cache_trees) + 1, 2) + return r + + +def _bicenter(n, cache, seed): + """Returns a bi-centroidal tree on `n` nodes drawn uniformly at random. + + This function implements the algorithm Bicenter of [1]_. + + Parameters + ---------- + n : int + The number of nodes (must be even). + cache : list of ints. + Cache for :func:`_num_rooted_trees`. + seed : random_state + See :ref:`Randomness` + + Returns + ------- + (edges, n) + The tree as a list of edges and number of nodes. + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + t, t_nodes = _random_unlabeled_rooted_tree(n // 2, cache, seed) + if seed.randint(0, _num_rooted_trees(n // 2, cache)) == 0: + t2, t2_nodes = t, t_nodes + else: + t2, t2_nodes = _random_unlabeled_rooted_tree(n // 2, cache, seed) + t.extend([(n1 + (n // 2), n2 + (n // 2)) for n1, n2 in t2]) + t.append((0, n // 2)) + return t, t_nodes + t2_nodes + + +def _random_unlabeled_tree(n, cache_trees, cache_forests, seed): + """Returns a tree on `n` nodes drawn uniformly at random. + It implements the Wilf's algorithm "Free" of [1]_. + + Parameters + ---------- + n : int + The number of nodes, greater than zero. + cache_trees : list of ints + Cache for :func:`_num_rooted_trees`. + cache_forests : list of ints + Cache for :func:`_num_rooted_forests`. + seed : random_state + Indicator of random number generation state. + See :ref:`Randomness` + + Returns + ------- + (edges, n) + The tree as a list of edges and number of nodes. + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + if n % 2 == 1: + p = 0 + else: + p = comb(_num_rooted_trees(n // 2, cache_trees) + 1, 2) + if seed.randint(0, _num_trees(n, cache_trees) - 1) < p: + return _bicenter(n, cache_trees, seed) + else: + f, n_f, r = _random_unlabeled_rooted_forest( + n - 1, (n - 1) // 2, cache_trees, cache_forests, seed + ) + for i in r: + f.append((i, n_f)) + return f, n_f + 1 + + +@py_random_state("seed") +@nx._dispatchable(graphs=None, returns_graph=True) +def random_unlabeled_tree(n, *, number_of_trees=None, seed=None): + """Returns a tree or list of trees chosen randomly. + + Returns one or more (depending on `number_of_trees`) + unlabeled trees with `n` nodes drawn uniformly at random. + + Parameters + ---------- + n : int + The number of nodes + number_of_trees : int or None (default) + If not None, this number of trees is generated and returned. + seed : integer, random_state, or None (default) + Indicator of random number generation state. + See :ref:`Randomness`. + + Returns + ------- + :class:`networkx.Graph` or list of :class:`networkx.Graph` + A single `networkx.Graph` (or a list thereof, if + `number_of_trees` is specified) with nodes in the set {0, …, *n* - 1}. + + Raises + ------ + NetworkXPointlessConcept + If `n` is zero (because the null graph is not a tree). + + Notes + ----- + This function generates an unlabeled tree uniformly at random using + Wilf's algorithm "Free" of [1]_. The algorithm needs to + compute some counting functions that are relatively expensive: + in case several trees are needed, it is advisable to use the + `number_of_trees` optional argument to reuse the counting + functions. + + References + ---------- + .. [1] Wilf, Herbert S. "The uniform selection of free trees." + Journal of Algorithms 2.2 (1981): 204-207. + https://doi.org/10.1016/0196-6774(81)90021-3 + """ + if n == 0: + raise nx.NetworkXPointlessConcept("the null graph is not a tree") + + cache_trees = [0, 1] # initial cache of number of rooted trees + cache_forests = [1] # initial cache of number of rooted forests + if number_of_trees is None: + return _to_nx(*_random_unlabeled_tree(n, cache_trees, cache_forests, seed)) + else: + return [ + _to_nx(*_random_unlabeled_tree(n, cache_trees, cache_forests, seed)) + for i in range(number_of_trees) + ] diff --git a/janus/lib/python3.10/site-packages/networkx/tests/__pycache__/__init__.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/tests/__pycache__/__init__.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..74f15849e1200ddf24a23ede9ffa825a6807cf0c Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/tests/__pycache__/__init__.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/utils/__pycache__/__init__.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/utils/__pycache__/__init__.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..6e65392cd2648a65b0e1fd36a46831ffd29b8db3 Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/utils/__pycache__/__init__.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/utils/__pycache__/backends.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/utils/__pycache__/backends.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..1a8dd2e1ba4d75a5ef8ceeffb29309c800b62956 Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/utils/__pycache__/backends.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/utils/backends.py b/janus/lib/python3.10/site-packages/networkx/utils/backends.py new file mode 100644 index 0000000000000000000000000000000000000000..0b41d4c780c48ec446d76fbd04de13fb06f2f4af --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/utils/backends.py @@ -0,0 +1,2501 @@ +""" +Docs for backend users +~~~~~~~~~~~~~~~~~~~~~~ +NetworkX utilizes a plugin-dispatch architecture. A valid NetworkX backend +specifies `entry points +`_, named +``networkx.backends`` and an optional ``networkx.backend_info`` when it is +installed (not imported). This allows NetworkX to dispatch (redirect) function +calls to the backend so the execution flows to the designated backend +implementation. This design enhances flexibility and integration, making +NetworkX more adaptable and efficient. + +NetworkX can dispatch to backends **explicitly** (this requires changing code) +or **automatically** (this requires setting configuration or environment +variables). The best way to use a backend depends on the backend, your use +case, and whether you want to automatically convert to or from backend +graphs. Automatic conversions of graphs is always opt-in. + +To explicitly dispatch to a backend, use the `backend=` keyword argument in a +dispatchable function. This will convert (and cache by default) input NetworkX +graphs to backend graphs and call the backend implementation. Another explicit +way to use a backend is to create a backend graph directly--for example, +perhaps the backend has its own functions for loading data and creating +graphs--and pass that graph to a dispatchable function, which will then call +the backend implementation without converting. + +Using automatic dispatch requires setting configuration options. Every NetworkX +configuration may also be set from an environment variable and are processed at +the time networkx is imported. The following configuration variables are +supported: + +* ``nx.config.backend_priority`` (``NETWORKX_BACKEND_PRIORITY`` env var), a + list of backends, controls dispatchable functions that don't return graphs + such as e.g. ``nx.pagerank``. When one of these functions is called with + NetworkX graphs as input, the dispatcher iterates over the backends listed in + this backend_priority config and will use the first backend that implements + this function. The input NetworkX graphs are converted (and cached by + default) to backend graphs. Using this configuration can allow you to use the + full flexibility of NetworkX graphs and the performance of backend + implementations, but possible downsides are that creating NetworkX graphs, + converting to backend graphs, and caching backend graphs may all be + expensive. + +* ``nx.config.backend_priority.algos`` (``NETWORKX_BACKEND_PRIORITY_ALGOS`` env + var), can be used instead of ``nx.config.backend_priority`` + (``NETWORKX_BACKEND_PRIORITY`` env var) to emphasize that the setting only + affects the dispatching of algorithm functions as described above. + +* ``nx.config.backend_priority.generators`` + (``NETWORKX_BACKEND_PRIORITY_GENERATORS`` env var), a list of backends, + controls dispatchable functions that return graphs such as + nx.from_pandas_edgelist and nx.empty_graph. When one of these functions is + called, the first backend listed in this backend_priority config that + implements this function will be used and will return a backend graph. When + this backend graph is passed to other dispatchable NetworkX functions, it + will use the backend implementation if it exists or raise by default unless + nx.config.fallback_to_nx is True (default is False). Using this configuration + avoids creating NetworkX graphs, which subsequently avoids the need to + convert to and cache backend graphs as when using + nx.config.backend_priority.algos, but possible downsides are that the backend + graph may not behave the same as a NetworkX graph and the backend may not + implement all algorithms that you use, which may break your workflow. + +* ``nx.config.fallback_to_nx`` (``NETWORKX_FALLBACK_TO_NX`` env var), a boolean + (default False), controls what happens when a backend graph is passed to a + dispatchable function that is not implemented by that backend. The default + behavior when False is to raise. If True, then the backend graph will be + converted (and cached by default) to a NetworkX graph and will run with the + default NetworkX implementation. Enabling this configuration can allow + workflows to complete if the backend does not implement all algorithms used + by the workflow, but a possible downside is that it may require converting + the input backend graph to a NetworkX graph, which may be expensive. If a + backend graph is duck-type compatible as a NetworkX graph, then the backend + may choose not to convert to a NetworkX graph and use the incoming graph + as-is. + +* ``nx.config.cache_converted_graphs`` (``NETWORKX_CACHE_CONVERTED_GRAPHS`` env + var), a boolean (default True), controls whether graph conversions are cached + to G.__networkx_cache__ or not. Caching can improve performance by avoiding + repeated conversions, but it uses more memory. + +.. note:: Backends *should* follow the NetworkX backend naming convention. For + example, if a backend is named ``parallel`` and specified using + ``backend=parallel`` or ``NETWORKX_BACKEND_PRIORITY=parallel``, the package + installed is ``nx-parallel``, and we would use ``import nx_parallel`` if we + were to import the backend package directly. + +Backends are encouraged to document how they recommend to be used and whether +their graph types are duck-type compatible as NetworkX graphs. If backend +graphs are NetworkX-compatible and you want your workflow to automatically +"just work" with a backend--converting and caching if necessary--then use all +of the above configurations. Automatically converting graphs is opt-in, and +configuration gives the user control. + +Examples: +--------- + +Use the ``cugraph`` backend for every algorithm function it supports. This will +allow for fall back to the default NetworkX implementations for algorithm calls +not supported by cugraph because graph generator functions are still returning +NetworkX graphs. + +.. code-block:: bash + + bash> NETWORKX_BACKEND_PRIORITY=cugraph python my_networkx_script.py + +Explicitly use the ``parallel`` backend for a function call. + +.. code-block:: python + + nx.betweenness_centrality(G, k=10, backend="parallel") + +Explicitly use the ``parallel`` backend for a function call by passing an +instance of the backend graph type to the function. + +.. code-block:: python + + H = nx_parallel.ParallelGraph(G) + nx.betweenness_centrality(H, k=10) + +Explicitly use the ``parallel`` backend and pass additional backend-specific +arguments. Here, ``get_chunks`` is an argument unique to the ``parallel`` +backend. + +.. code-block:: python + + nx.betweenness_centrality(G, k=10, backend="parallel", get_chunks=get_chunks) + +Automatically dispatch the ``cugraph`` backend for all NetworkX algorithms and +generators, and allow the backend graph object returned from generators to be +passed to NetworkX functions the backend does not support. + +.. code-block:: bash + + bash> NETWORKX_BACKEND_PRIORITY_ALGOS=cugraph \\ + NETWORKX_BACKEND_PRIORITY_GENERATORS=cugraph \\ + NETWORKX_FALLBACK_TO_NX=True \\ + python my_networkx_script.py + +How does this work? +------------------- + +If you've looked at functions in the NetworkX codebase, you might have seen the +``@nx._dispatchable`` decorator on most of the functions. This decorator allows the NetworkX +function to dispatch to the corresponding backend function if available. When the decorated +function is called, it first checks for a backend to run the function, and if no appropriate +backend is specified or available, it runs the NetworkX version of the function. + +Backend Keyword Argument +^^^^^^^^^^^^^^^^^^^^^^^^ + +When a decorated function is called with the ``backend`` kwarg provided, it checks +if the specified backend is installed, and loads it. Next it checks whether to convert +input graphs by first resolving the backend of each input graph by looking +for an attribute named ``__networkx_backend__`` that holds the backend name for that +graph type. If all input graphs backend matches the ``backend`` kwarg, the backend's +function is called with the original inputs. If any of the input graphs do not match +the ``backend`` kwarg, they are converted to the backend graph type before calling. +Exceptions are raised if any step is not possible, e.g. if the backend does not +implement this function. + +Finding a Backend +^^^^^^^^^^^^^^^^^ + +When a decorated function is called without a ``backend`` kwarg, it tries to find a +dispatchable backend function. +The backend type of each input graph parameter is resolved (using the +``__networkx_backend__`` attribute) and if they all agree, that backend's function +is called if possible. Otherwise the backends listed in the config ``backend_priority`` +are considered one at a time in order. If that backend supports the function and +can convert the input graphs to its backend type, that backend function is called. +Otherwise the next backend is considered. + +During this process, the backends can provide helpful information to the dispatcher +via helper methods in the backend's interface. Backend methods ``can_run`` and +``should_run`` are used by the dispatcher to determine whether to use the backend +function. If the number of nodes is small, it might be faster to run the NetworkX +version of the function. This is how backends can provide info about whether to run. + +Falling Back to NetworkX +^^^^^^^^^^^^^^^^^^^^^^^^ + +If none of the backends are appropriate, we "fall back" to the NetworkX function. +That means we resolve the backends of all input graphs and if all are NetworkX +graphs we call the NetworkX function. If any are not NetworkX graphs, we raise +an exception unless the `fallback_to_nx` config is set. If it is, we convert all +graph types to NetworkX graph types before calling the NetworkX function. + +Functions that mutate the graph +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Any function decorated with the option that indicates it mutates the graph goes through +a slightly different path to automatically find backends. These functions typically +generate a graph, or add attributes or change the graph structure. The config +`backend_priority.generators` holds a list of backend names similar to the config +`backend_priority`. The process is similar for finding a matching backend. Once found, +the backend function is called and a backend graph is returned (instead of a NetworkX +graph). You can then use this backend graph in any function supported by the backend. +And you can use it for functions not supported by the backend if you set the config +`fallback_to_nx` to allow it to convert the backend graph to a NetworkX graph before +calling the function. + +Optional keyword arguments +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Backends can add optional keyword parameters to NetworkX functions to allow you to +control aspects of the backend algorithm. Thus the function signatures can be extended +beyond the NetworkX function signature. For example, the ``parallel`` backend might +have a parameter to specify how many CPUs to use. These parameters are collected +by the dispatchable decorator code at the start of the function call and used when +calling the backend function. + +Existing Backends +^^^^^^^^^^^^^^^^^ + +NetworkX does not know all the backends that have been created. In fact, the +NetworkX library does not need to know that a backend exists for it to work. As +long as the backend package creates the ``entry_point``, and provides the +correct interface, it will be called when the user requests it using one of the +three approaches described above. Some backends have been working with the +NetworkX developers to ensure smooth operation. + +Refer to the :doc:`/backends` section to see a list of available backends known +to work with the current stable release of NetworkX. + +.. _introspect: + +Introspection and Logging +------------------------- +Introspection techniques aim to demystify dispatching and backend graph conversion behaviors. + +The primary way to see what the dispatch machinery is doing is by enabling logging. +This can help you verify that the backend you specified is being used. +You can enable NetworkX's backend logger to print to ``sys.stderr`` like this:: + + import logging + nxl = logging.getLogger("networkx") + nxl.addHandler(logging.StreamHandler()) + nxl.setLevel(logging.DEBUG) + +And you can disable it by running this:: + + nxl.setLevel(logging.CRITICAL) + +Refer to :external+python:mod:`logging` to learn more about the logging facilities in Python. + +By looking at the ``.backends`` attribute, you can get the set of all currently +installed backends that implement a particular function. For example:: + + >>> nx.betweenness_centrality.backends # doctest: +SKIP + {'parallel'} + +The function docstring will also show which installed backends support it +along with any backend-specific notes and keyword arguments:: + + >>> help(nx.betweenness_centrality) # doctest: +SKIP + ... + Backends + -------- + parallel : Parallel backend for NetworkX algorithms + The parallel computation is implemented by dividing the nodes into chunks + and computing betweenness centrality for each chunk concurrently. + ... + +The NetworkX documentation website also includes info about trusted backends of NetworkX in function references. +For example, see :func:`~networkx.algorithms.shortest_paths.weighted.all_pairs_bellman_ford_path_length`. + +Introspection capabilities are currently limited, but we are working to improve them. +We plan to make it easier to answer questions such as: + +- What happened (and why)? +- What *will* happen (and why)? +- Where was time spent (including conversions)? +- What is in the cache and how much memory is it using? + +Transparency is essential to allow for greater understanding, debug-ability, +and customization. After all, NetworkX dispatching is extremely flexible and can +support advanced workflows with multiple backends and fine-tuned configuration, +but introspection can be helpful by describing *when* and *how* to evolve your workflow +to meet your needs. If you have suggestions for how to improve introspection, please +`let us know `_! + +Docs for backend developers +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Creating a custom backend +------------------------- + +1. Defining a ``BackendInterface`` object: + + Note that the ``BackendInterface`` doesn't need to must be a class. It can be an + instance of a class, or a module as well. You can define the following methods or + functions in your backend's ``BackendInterface`` object.: + + 1. ``convert_from_nx`` and ``convert_to_nx`` methods or functions are required for + backend dispatching to work. The arguments to ``convert_from_nx`` are: + + - ``G`` : NetworkX Graph + - ``edge_attrs`` : dict, optional + Dictionary mapping edge attributes to default values if missing in ``G``. + If None, then no edge attributes will be converted and default may be 1. + - ``node_attrs``: dict, optional + Dictionary mapping node attributes to default values if missing in ``G``. + If None, then no node attributes will be converted. + - ``preserve_edge_attrs`` : bool + Whether to preserve all edge attributes. + - ``preserve_node_attrs`` : bool + Whether to preserve all node attributes. + - ``preserve_graph_attrs`` : bool + Whether to preserve all graph attributes. + - ``preserve_all_attrs`` : bool + Whether to preserve all graph, node, and edge attributes. + - ``name`` : str + The name of the algorithm. + - ``graph_name`` : str + The name of the graph argument being converted. + + 2. ``can_run`` (Optional): + If your backend only partially implements an algorithm, you can define + a ``can_run(name, args, kwargs)`` function in your ``BackendInterface`` object that + returns True or False indicating whether the backend can run the algorithm with + the given arguments or not. Instead of a boolean you can also return a string + message to inform the user why that algorithm can't be run. + + 3. ``should_run`` (Optional): + A backend may also define ``should_run(name, args, kwargs)`` + that is similar to ``can_run``, but answers whether the backend *should* be run. + ``should_run`` is only run when performing backend graph conversions. Like + ``can_run``, it receives the original arguments so it can decide whether it + should be run by inspecting the arguments. ``can_run`` runs before + ``should_run``, so ``should_run`` may assume ``can_run`` is True. If not + implemented by the backend, ``can_run``and ``should_run`` are assumed to + always return True if the backend implements the algorithm. + + 4. ``on_start_tests`` (Optional): + A special ``on_start_tests(items)`` function may be defined by the backend. + It will be called with the list of NetworkX tests discovered. Each item + is a test object that can be marked as xfail if the backend does not support + the test using ``item.add_marker(pytest.mark.xfail(reason=...))``. + +2. Adding entry points + + To be discoverable by NetworkX, your package must register an + `entry-point `_ + ``networkx.backends`` in the package's metadata, with a `key pointing to your + dispatch object `_ . + For example, if you are using ``setuptools`` to manage your backend package, + you can `add the following to your pyproject.toml file `_:: + + [project.entry-points."networkx.backends"] + backend_name = "your_backend_interface_object" + + You can also add the ``backend_info`` entry-point. It points towards the ``get_info`` + function that returns all the backend information, which is then used to build the + "Additional Backend Implementation" box at the end of algorithm's documentation + page. Note that the `get_info` function shouldn't import your backend package.:: + + [project.entry-points."networkx.backend_info"] + backend_name = "your_get_info_function" + + The ``get_info`` should return a dictionary with following key-value pairs: + - ``backend_name`` : str or None + It is the name passed in the ``backend`` kwarg. + - ``project`` : str or None + The name of your backend project. + - ``package`` : str or None + The name of your backend package. + - ``url`` : str or None + This is the url to either your backend's codebase or documentation, and + will be displayed as a hyperlink to the ``backend_name``, in the + "Additional backend implementations" section. + - ``short_summary`` : str or None + One line summary of your backend which will be displayed in the + "Additional backend implementations" section. + - ``default_config`` : dict + A dictionary mapping the backend config parameter names to their default values. + This is used to automatically initialize the default configs for all the + installed backends at the time of networkx's import. + + .. seealso:: `~networkx.utils.configs.Config` + + - ``functions`` : dict or None + A dictionary mapping function names to a dictionary of information + about the function. The information can include the following keys: + + - ``url`` : str or None + The url to ``function``'s source code or documentation. + - ``additional_docs`` : str or None + A short description or note about the backend function's + implementation. + - ``additional_parameters`` : dict or None + A dictionary mapping additional parameters headers to their + short descriptions. For example:: + + "additional_parameters": { + 'param1 : str, function (default = "chunks")' : "...", + 'param2 : int' : "...", + } + + If any of these keys are not present, the corresponding information + will not be displayed in the "Additional backend implementations" + section on NetworkX docs website. + + Note that your backend's docs would only appear on the official NetworkX docs only + if your backend is a trusted backend of NetworkX, and is present in the + `.circleci/config.yml` and `.github/workflows/deploy-docs.yml` files in the + NetworkX repository. + +3. Defining a Backend Graph class + + The backend must create an object with an attribute ``__networkx_backend__`` that holds + a string with the entry point name:: + + class BackendGraph: + __networkx_backend__ = "backend_name" + ... + + A backend graph instance may have a ``G.__networkx_cache__`` dict to enable + caching, and care should be taken to clear the cache when appropriate. + +Testing the Custom backend +-------------------------- + +To test your custom backend, you can run the NetworkX test suite on your backend. +This also ensures that the custom backend is compatible with NetworkX's API. +The following steps will help you run the tests: + +1. Setting Backend Environment Variables: + - ``NETWORKX_TEST_BACKEND`` : Setting this to your backend's ``backend_name`` will + let NetworkX's dispatch machinery to automatically convert a regular NetworkX + ``Graph``, ``DiGraph``, ``MultiGraph``, etc. to their backend equivalents, using + ``your_backend_interface_object.convert_from_nx(G, ...)`` function. + - ``NETWORKX_FALLBACK_TO_NX`` (default=False) : Setting this variable to `True` will + instruct tests to use a NetworkX ``Graph`` for algorithms not implemented by your + custom backend. Setting this to `False` will only run the tests for algorithms + implemented by your custom backend and tests for other algorithms will ``xfail``. + +2. Running Tests: + You can invoke NetworkX tests for your custom backend with the following commands:: + + NETWORKX_TEST_BACKEND= + NETWORKX_FALLBACK_TO_NX=True # or False + pytest --pyargs networkx + +How tests are run? +------------------ + +1. While dispatching to the backend implementation the ``_convert_and_call`` function + is used and while testing the ``_convert_and_call_for_tests`` function is used. + Other than testing it also checks for functions that return numpy scalars, and + for functions that return graphs it runs the backend implementation and the + networkx implementation and then converts the backend graph into a NetworkX graph + and then compares them, and returns the networkx graph. This can be regarded as + (pragmatic) technical debt. We may replace these checks in the future. + +2. Conversions while running tests: + - Convert NetworkX graphs using ``.convert_from_nx(G, ...)`` into + the backend graph. + - Pass the backend graph objects to the backend implementation of the algorithm. + - Convert the result back to a form expected by NetworkX tests using + ``.convert_to_nx(result, ...)``. + - For nx_loopback, the graph is copied using the dispatchable metadata + +3. Dispatchable algorithms that are not implemented by the backend + will cause a ``pytest.xfail``, when the ``NETWORKX_FALLBACK_TO_NX`` + environment variable is set to ``False``, giving some indication that + not all tests are running, while avoiding causing an explicit failure. +""" + +import inspect +import itertools +import logging +import os +import warnings +from functools import partial +from importlib.metadata import entry_points + +import networkx as nx + +from .configs import BackendPriorities, Config, NetworkXConfig +from .decorators import argmap + +__all__ = ["_dispatchable"] + +_logger = logging.getLogger(__name__) + + +def _do_nothing(): + """This does nothing at all, yet it helps turn `_dispatchable` into functions.""" + + +def _get_backends(group, *, load_and_call=False): + """ + Retrieve NetworkX ``backends`` and ``backend_info`` from the entry points. + + Parameters + ----------- + group : str + The entry_point to be retrieved. + load_and_call : bool, optional + If True, load and call the backend. Defaults to False. + + Returns + -------- + dict + A dictionary mapping backend names to their respective backend objects. + + Notes + ------ + If a backend is defined more than once, a warning is issued. + The `nx_loopback` backend is removed if it exists, as it is only available during testing. + A warning is displayed if an error occurs while loading a backend. + """ + items = entry_points(group=group) + rv = {} + for ep in items: + if ep.name in rv: + warnings.warn( + f"networkx backend defined more than once: {ep.name}", + RuntimeWarning, + stacklevel=2, + ) + elif load_and_call: + try: + rv[ep.name] = ep.load()() + except Exception as exc: + warnings.warn( + f"Error encountered when loading info for backend {ep.name}: {exc}", + RuntimeWarning, + stacklevel=2, + ) + else: + rv[ep.name] = ep + rv.pop("nx_loopback", None) + return rv + + +# Note: "networkx" will be in `backend_info`, but not `backends` or `config.backends`. +# It is valid to use "networkx"` as backend argument and in `config.backend_priority`. +# We may make "networkx" a "proper" backend and have it in `backends` and `config.backends`. +backends = _get_backends("networkx.backends") +backend_info = {} # fill backend_info after networkx is imported in __init__.py + +# Load and cache backends on-demand +_loaded_backends = {} # type: ignore[var-annotated] +_registered_algorithms = {} + + +# Get default configuration from environment variables at import time +def _comma_sep_to_list(string): + return [stripped for x in string.strip().split(",") if (stripped := x.strip())] + + +def _set_configs_from_environment(): + """Initialize ``config.backend_priority``, load backend_info and config. + + This gets default values from environment variables (see ``nx.config`` for details). + This function is run at the very end of importing networkx. It is run at this time + to avoid loading backend_info before the rest of networkx is imported in case a + backend uses networkx for its backend_info (e.g. subclassing the Config class.) + """ + # backend_info is defined above as empty dict. Fill it after import finishes. + backend_info.update(_get_backends("networkx.backend_info", load_and_call=True)) + backend_info.update( + (backend, {}) for backend in backends.keys() - backend_info.keys() + ) + + # set up config based on backend_info and environment + config = NetworkXConfig( + backend_priority=BackendPriorities( + algos=[], + generators=[], + ), + backends=Config( + **{ + backend: ( + cfg + if isinstance(cfg := info["default_config"], Config) + else Config(**cfg) + ) + if "default_config" in info + else Config() + for backend, info in backend_info.items() + } + ), + cache_converted_graphs=bool( + os.environ.get("NETWORKX_CACHE_CONVERTED_GRAPHS", True) + ), + fallback_to_nx=bool(os.environ.get("NETWORKX_FALLBACK_TO_NX", False)), + warnings_to_ignore={ + x.strip() + for x in os.environ.get("NETWORKX_WARNINGS_TO_IGNORE", "").split(",") + if x.strip() + }, + ) + backend_info["networkx"] = {} + type(config.backends).__doc__ = "All installed NetworkX backends and their configs." + + # NETWORKX_BACKEND_PRIORITY is the same as NETWORKX_BACKEND_PRIORITY_ALGOS + priorities = { + key[26:].lower(): val + for key, val in os.environ.items() + if key.startswith("NETWORKX_BACKEND_PRIORITY_") + } + backend_priority = config.backend_priority + backend_priority.algos = ( + _comma_sep_to_list(priorities.pop("algos")) + if "algos" in priorities + else _comma_sep_to_list( + os.environ.get( + "NETWORKX_BACKEND_PRIORITY", + os.environ.get("NETWORKX_AUTOMATIC_BACKENDS", ""), + ) + ) + ) + backend_priority.generators = _comma_sep_to_list(priorities.pop("generators", "")) + for key in sorted(priorities): + backend_priority[key] = _comma_sep_to_list(priorities[key]) + + return config + + +def _always_run(name, args, kwargs): + return True + + +def _load_backend(backend_name): + if backend_name in _loaded_backends: + return _loaded_backends[backend_name] + if backend_name not in backends: + raise ImportError(f"'{backend_name}' backend is not installed") + rv = _loaded_backends[backend_name] = backends[backend_name].load() + if not hasattr(rv, "can_run"): + rv.can_run = _always_run + if not hasattr(rv, "should_run"): + rv.should_run = _always_run + return rv + + +class _dispatchable: + _is_testing = False + + class _fallback_to_nx: + """Class property that returns ``nx.config.fallback_to_nx``.""" + + def __get__(self, instance, owner=None): + warnings.warn( + "`_dispatchable._fallback_to_nx` is deprecated and will be removed " + "in NetworkX v3.5. Use `nx.config.fallback_to_nx` instead.", + category=DeprecationWarning, + stacklevel=2, + ) + return nx.config.fallback_to_nx + + # Note that chaining `@classmethod` and `@property` was removed in Python 3.13 + _fallback_to_nx = _fallback_to_nx() # type: ignore[assignment,misc] + + def __new__( + cls, + func=None, + *, + name=None, + graphs="G", + edge_attrs=None, + node_attrs=None, + preserve_edge_attrs=False, + preserve_node_attrs=False, + preserve_graph_attrs=False, + preserve_all_attrs=False, + mutates_input=False, + returns_graph=False, + ): + """A decorator function that is used to redirect the execution of ``func`` + function to its backend implementation. + + This decorator function dispatches to + a different backend implementation based on the input graph types, and it also + manages all the ``backend_kwargs``. Usage can be any of the following decorator + forms: + + - ``@_dispatchable`` + - ``@_dispatchable()`` + - ``@_dispatchable(name="override_name")`` + - ``@_dispatchable(graphs="graph_var_name")`` + - ``@_dispatchable(edge_attrs="weight")`` + - ``@_dispatchable(graphs={"G": 0, "H": 1}, edge_attrs={"weight": "default"})`` + with 0 and 1 giving the position in the signature function for graph + objects. When ``edge_attrs`` is a dict, keys are keyword names and values + are defaults. + + Parameters + ---------- + func : callable, optional + The function to be decorated. If ``func`` is not provided, returns a + partial object that can be used to decorate a function later. If ``func`` + is provided, returns a new callable object that dispatches to a backend + algorithm based on input graph types. + + name : str, optional + The name of the algorithm to use for dispatching. If not provided, + the name of ``func`` will be used. ``name`` is useful to avoid name + conflicts, as all dispatched algorithms live in a single namespace. + For example, ``tournament.is_strongly_connected`` had a name conflict + with the standard ``nx.is_strongly_connected``, so we used + ``@_dispatchable(name="tournament_is_strongly_connected")``. + + graphs : str or dict or None, default "G" + If a string, the parameter name of the graph, which must be the first + argument of the wrapped function. If more than one graph is required + for the algorithm (or if the graph is not the first argument), provide + a dict keyed to argument names with argument position as values for each + graph argument. For example, ``@_dispatchable(graphs={"G": 0, "auxiliary?": 4})`` + indicates the 0th parameter ``G`` of the function is a required graph, + and the 4th parameter ``auxiliary?`` is an optional graph. + To indicate that an argument is a list of graphs, do ``"[graphs]"``. + Use ``graphs=None``, if *no* arguments are NetworkX graphs such as for + graph generators, readers, and conversion functions. + + edge_attrs : str or dict, optional + ``edge_attrs`` holds information about edge attribute arguments + and default values for those edge attributes. + If a string, ``edge_attrs`` holds the function argument name that + indicates a single edge attribute to include in the converted graph. + The default value for this attribute is 1. To indicate that an argument + is a list of attributes (all with default value 1), use e.g. ``"[attrs]"``. + If a dict, ``edge_attrs`` holds a dict keyed by argument names, with + values that are either the default value or, if a string, the argument + name that indicates the default value. + + node_attrs : str or dict, optional + Like ``edge_attrs``, but for node attributes. + + preserve_edge_attrs : bool or str or dict, optional + For bool, whether to preserve all edge attributes. + For str, the parameter name that may indicate (with ``True`` or a + callable argument) whether all edge attributes should be preserved + when converting. + For dict of ``{graph_name: {attr: default}}``, indicate pre-determined + edge attributes (and defaults) to preserve for input graphs. + + preserve_node_attrs : bool or str or dict, optional + Like ``preserve_edge_attrs``, but for node attributes. + + preserve_graph_attrs : bool or set + For bool, whether to preserve all graph attributes. + For set, which input graph arguments to preserve graph attributes. + + preserve_all_attrs : bool + Whether to preserve all edge, node and graph attributes. + This overrides all the other preserve_*_attrs. + + mutates_input : bool or dict, default False + For bool, whether the function mutates an input graph argument. + For dict of ``{arg_name: arg_pos}``, arguments that indicate whether an + input graph will be mutated, and ``arg_name`` may begin with ``"not "`` + to negate the logic (for example, this is used by ``copy=`` arguments). + By default, dispatching doesn't convert input graphs to a different + backend for functions that mutate input graphs. + + returns_graph : bool, default False + Whether the function can return or yield a graph object. By default, + dispatching doesn't convert input graphs to a different backend for + functions that return graphs. + """ + if func is None: + return partial( + _dispatchable, + name=name, + graphs=graphs, + edge_attrs=edge_attrs, + node_attrs=node_attrs, + preserve_edge_attrs=preserve_edge_attrs, + preserve_node_attrs=preserve_node_attrs, + preserve_graph_attrs=preserve_graph_attrs, + preserve_all_attrs=preserve_all_attrs, + mutates_input=mutates_input, + returns_graph=returns_graph, + ) + if isinstance(func, str): + raise TypeError("'name' and 'graphs' must be passed by keyword") from None + # If name not provided, use the name of the function + if name is None: + name = func.__name__ + + self = object.__new__(cls) + + # standard function-wrapping stuff + # __annotations__ not used + self.__name__ = func.__name__ + # self.__doc__ = func.__doc__ # __doc__ handled as cached property + self.__defaults__ = func.__defaults__ + # We "magically" add `backend=` keyword argument to allow backend to be specified + if func.__kwdefaults__: + self.__kwdefaults__ = {**func.__kwdefaults__, "backend": None} + else: + self.__kwdefaults__ = {"backend": None} + self.__module__ = func.__module__ + self.__qualname__ = func.__qualname__ + self.__dict__.update(func.__dict__) + self.__wrapped__ = func + + # Supplement docstring with backend info; compute and cache when needed + self._orig_doc = func.__doc__ + self._cached_doc = None + + self.orig_func = func + self.name = name + self.edge_attrs = edge_attrs + self.node_attrs = node_attrs + self.preserve_edge_attrs = preserve_edge_attrs or preserve_all_attrs + self.preserve_node_attrs = preserve_node_attrs or preserve_all_attrs + self.preserve_graph_attrs = preserve_graph_attrs or preserve_all_attrs + self.mutates_input = mutates_input + # Keep `returns_graph` private for now, b/c we may extend info on return types + self._returns_graph = returns_graph + + if edge_attrs is not None and not isinstance(edge_attrs, str | dict): + raise TypeError( + f"Bad type for edge_attrs: {type(edge_attrs)}. Expected str or dict." + ) from None + if node_attrs is not None and not isinstance(node_attrs, str | dict): + raise TypeError( + f"Bad type for node_attrs: {type(node_attrs)}. Expected str or dict." + ) from None + if not isinstance(self.preserve_edge_attrs, bool | str | dict): + raise TypeError( + f"Bad type for preserve_edge_attrs: {type(self.preserve_edge_attrs)}." + " Expected bool, str, or dict." + ) from None + if not isinstance(self.preserve_node_attrs, bool | str | dict): + raise TypeError( + f"Bad type for preserve_node_attrs: {type(self.preserve_node_attrs)}." + " Expected bool, str, or dict." + ) from None + if not isinstance(self.preserve_graph_attrs, bool | set): + raise TypeError( + f"Bad type for preserve_graph_attrs: {type(self.preserve_graph_attrs)}." + " Expected bool or set." + ) from None + if not isinstance(self.mutates_input, bool | dict): + raise TypeError( + f"Bad type for mutates_input: {type(self.mutates_input)}." + " Expected bool or dict." + ) from None + if not isinstance(self._returns_graph, bool): + raise TypeError( + f"Bad type for returns_graph: {type(self._returns_graph)}." + " Expected bool." + ) from None + + if isinstance(graphs, str): + graphs = {graphs: 0} + elif graphs is None: + pass + elif not isinstance(graphs, dict): + raise TypeError( + f"Bad type for graphs: {type(graphs)}. Expected str or dict." + ) from None + elif len(graphs) == 0: + raise KeyError("'graphs' must contain at least one variable name") from None + + # This dict comprehension is complicated for better performance; equivalent shown below. + self.optional_graphs = set() + self.list_graphs = set() + if graphs is None: + self.graphs = {} + else: + self.graphs = { + self.optional_graphs.add(val := k[:-1]) or val + if (last := k[-1]) == "?" + else self.list_graphs.add(val := k[1:-1]) or val + if last == "]" + else k: v + for k, v in graphs.items() + } + # The above is equivalent to: + # self.optional_graphs = {k[:-1] for k in graphs if k[-1] == "?"} + # self.list_graphs = {k[1:-1] for k in graphs if k[-1] == "]"} + # self.graphs = {k[:-1] if k[-1] == "?" else k: v for k, v in graphs.items()} + + # Compute and cache the signature on-demand + self._sig = None + + # Which backends implement this function? + self.backends = { + backend + for backend, info in backend_info.items() + if "functions" in info and name in info["functions"] + } + + if name in _registered_algorithms: + raise KeyError( + f"Algorithm already exists in dispatch registry: {name}" + ) from None + # Use the magic of `argmap` to turn `self` into a function. This does result + # in small additional overhead compared to calling `_dispatchable` directly, + # but `argmap` has the magical property that it can stack with other `argmap` + # decorators "for free". Being a function is better for REPRs and type-checkers. + self = argmap(_do_nothing)(self) + _registered_algorithms[name] = self + return self + + @property + def __doc__(self): + """If the cached documentation exists, it is returned. + Otherwise, the documentation is generated using _make_doc() method, + cached, and then returned.""" + + if (rv := self._cached_doc) is not None: + return rv + rv = self._cached_doc = self._make_doc() + return rv + + @__doc__.setter + def __doc__(self, val): + """Sets the original documentation to the given value and resets the + cached documentation.""" + + self._orig_doc = val + self._cached_doc = None + + @property + def __signature__(self): + """Return the signature of the original function, with the addition of + the `backend` and `backend_kwargs` parameters.""" + + if self._sig is None: + sig = inspect.signature(self.orig_func) + # `backend` is now a reserved argument used by dispatching. + # assert "backend" not in sig.parameters + if not any( + p.kind == inspect.Parameter.VAR_KEYWORD for p in sig.parameters.values() + ): + sig = sig.replace( + parameters=[ + *sig.parameters.values(), + inspect.Parameter( + "backend", inspect.Parameter.KEYWORD_ONLY, default=None + ), + inspect.Parameter( + "backend_kwargs", inspect.Parameter.VAR_KEYWORD + ), + ] + ) + else: + *parameters, var_keyword = sig.parameters.values() + sig = sig.replace( + parameters=[ + *parameters, + inspect.Parameter( + "backend", inspect.Parameter.KEYWORD_ONLY, default=None + ), + var_keyword, + ] + ) + self._sig = sig + return self._sig + + def __call__(self, /, *args, backend=None, **kwargs): + """Returns the result of the original function, or the backend function if + the backend is specified and that backend implements `func`.""" + + if not backends: + # Fast path if no backends are installed + if backend is not None and backend != "networkx": + raise ImportError(f"'{backend}' backend is not installed") + return self.orig_func(*args, **kwargs) + + # Use `backend_name` in this function instead of `backend`. + # This is purely for aesthetics and to make it easier to search for this + # variable since "backend" is used in many comments and log/error messages. + backend_name = backend + if backend_name is not None and backend_name not in backend_info: + raise ImportError(f"'{backend_name}' backend is not installed") + + graphs_resolved = {} + for gname, pos in self.graphs.items(): + if pos < len(args): + if gname in kwargs: + raise TypeError(f"{self.name}() got multiple values for {gname!r}") + graph = args[pos] + elif gname in kwargs: + graph = kwargs[gname] + elif gname not in self.optional_graphs: + raise TypeError( + f"{self.name}() missing required graph argument: {gname}" + ) + else: + continue + if graph is None: + if gname not in self.optional_graphs: + raise TypeError( + f"{self.name}() required graph argument {gname!r} is None; must be a graph" + ) + else: + graphs_resolved[gname] = graph + + # Alternative to the above that does not check duplicated args or missing required graphs. + # graphs_resolved = { + # gname: graph + # for gname, pos in self.graphs.items() + # if (graph := args[pos] if pos < len(args) else kwargs.get(gname)) is not None + # } + + # Check if any graph comes from a backend + if self.list_graphs: + # Make sure we don't lose values by consuming an iterator + args = list(args) + for gname in self.list_graphs & graphs_resolved.keys(): + list_of_graphs = list(graphs_resolved[gname]) + graphs_resolved[gname] = list_of_graphs + if gname in kwargs: + kwargs[gname] = list_of_graphs + else: + args[self.graphs[gname]] = list_of_graphs + + graph_backend_names = { + getattr(g, "__networkx_backend__", None) + for gname, g in graphs_resolved.items() + if gname not in self.list_graphs + } + for gname in self.list_graphs & graphs_resolved.keys(): + graph_backend_names.update( + getattr(g, "__networkx_backend__", None) + for g in graphs_resolved[gname] + ) + else: + graph_backend_names = { + getattr(g, "__networkx_backend__", None) + for g in graphs_resolved.values() + } + + backend_priority = nx.config.backend_priority.get( + self.name, + nx.config.backend_priority.generators + if self._returns_graph + else nx.config.backend_priority.algos, + ) + if self._is_testing and backend_priority and backend_name is None: + # Special path if we are running networkx tests with a backend. + # This even runs for (and handles) functions that mutate input graphs. + return self._convert_and_call_for_tests( + backend_priority[0], + args, + kwargs, + fallback_to_nx=nx.config.fallback_to_nx, + ) + + graph_backend_names.discard(None) + if backend_name is not None: + # Must run with the given backend. + # `can_run` only used for better log and error messages. + # Check `mutates_input` for logging, not behavior. + blurb = ( + "No other backends will be attempted, because the backend was " + f"specified with the `backend='{backend_name}'` keyword argument." + ) + extra_message = ( + f"'{backend_name}' backend raised NotImplementedError when calling " + f"`{self.name}'. {blurb}" + ) + if not graph_backend_names or graph_backend_names == {backend_name}: + # All graphs are backend graphs--no need to convert! + if self._can_backend_run(backend_name, args, kwargs): + return self._call_with_backend( + backend_name, args, kwargs, extra_message=extra_message + ) + if self._does_backend_have(backend_name): + extra = " for the given arguments" + else: + extra = "" + raise NotImplementedError( + f"`{self.name}' is not implemented by '{backend_name}' backend" + f"{extra}. {blurb}" + ) + if self._can_convert(backend_name, graph_backend_names): + if self._can_backend_run(backend_name, args, kwargs): + if self._will_call_mutate_input(args, kwargs): + _logger.debug( + "`%s' will mutate an input graph. This prevents automatic conversion " + "to, and use of, backends listed in `nx.config.backend_priority`. " + "Using backend specified by the " + "`backend='%s'` keyword argument. This may change behavior by not " + "mutating inputs.", + self.name, + backend_name, + ) + mutations = [] + else: + mutations = None + rv = self._convert_and_call( + backend_name, + graph_backend_names, + args, + kwargs, + extra_message=extra_message, + mutations=mutations, + ) + if mutations: + for cache, key in mutations: + # If the call mutates inputs, then remove all inputs gotten + # from cache. We do this after all conversions (and call) so + # that a graph can be gotten from a cache multiple times. + cache.pop(key, None) + return rv + if self._does_backend_have(backend_name): + extra = " for the given arguments" + else: + extra = "" + raise NotImplementedError( + f"`{self.name}' is not implemented by '{backend_name}' backend" + f"{extra}. {blurb}" + ) + if len(graph_backend_names) == 1: + maybe_s = "" + graph_backend_names = f"'{next(iter(graph_backend_names))}'" + else: + maybe_s = "s" + raise TypeError( + f"`{self.name}' is unable to convert graph from backend{maybe_s} " + f"{graph_backend_names} to '{backend_name}' backend, which was " + f"specified with the `backend='{backend_name}'` keyword argument. " + f"{blurb}" + ) + + if self._will_call_mutate_input(args, kwargs): + # The current behavior for functions that mutate input graphs: + # + # 1. If backend is specified by `backend=` keyword, use it (done above). + # 2. If inputs are from one backend, try to use it. + # 3. If all input graphs are instances of `nx.Graph`, then run with the + # default "networkx" implementation. + # + # Do not automatically convert if a call will mutate inputs, because doing + # so would change behavior. Hence, we should fail if there are multiple input + # backends or if the input backend does not implement the function. However, + # we offer a way for backends to circumvent this if they do not implement + # this function: we will fall back to the default "networkx" implementation + # without using conversions if all input graphs are subclasses of `nx.Graph`. + blurb = ( + "conversions between backends (if configured) will not be attempted, " + "because this may change behavior. You may specify a backend to use " + "by passing e.g. `backend='networkx'` keyword, but this may also " + "change behavior by not mutating inputs." + ) + fallback_blurb = ( + "This call will mutate inputs, so fall back to 'networkx' " + "backend (without converting) since all input graphs are " + "instances of nx.Graph and are hopefully compatible.", + ) + if len(graph_backend_names) == 1: + [backend_name] = graph_backend_names + msg_template = ( + f"Backend '{backend_name}' does not implement `{self.name}'%s. " + f"This call will mutate an input, so automatic {blurb}" + ) + # `can_run` is only used for better log and error messages + try: + if self._can_backend_run(backend_name, args, kwargs): + return self._call_with_backend( + backend_name, + args, + kwargs, + extra_message=msg_template % " with these arguments", + ) + except NotImplementedError as exc: + if all(isinstance(g, nx.Graph) for g in graphs_resolved.values()): + _logger.debug( + "Backend '%s' raised when calling `%s': %s. %s", + backend_name, + self.name, + exc, + fallback_blurb, + ) + else: + raise + else: + if nx.config.fallback_to_nx and all( + # Consider dropping the `isinstance` check here to allow + # duck-type graphs, but let's wait for a backend to ask us. + isinstance(g, nx.Graph) + for g in graphs_resolved.values() + ): + # Log that we are falling back to networkx + _logger.debug( + "Backend '%s' can't run `%s'. %s", + backend_name, + self.name, + fallback_blurb, + ) + else: + if self._does_backend_have(backend_name): + extra = " with these arguments" + else: + extra = "" + raise NotImplementedError(msg_template % extra) + elif nx.config.fallback_to_nx and all( + # Consider dropping the `isinstance` check here to allow + # duck-type graphs, but let's wait for a backend to ask us. + isinstance(g, nx.Graph) + for g in graphs_resolved.values() + ): + # Log that we are falling back to networkx + _logger.debug( + "`%s' was called with inputs from multiple backends: %s. %s", + self.name, + graph_backend_names, + fallback_blurb, + ) + else: + raise RuntimeError( + f"`{self.name}' will mutate an input, but it was called with inputs " + f"from multiple backends: {graph_backend_names}. Automatic {blurb}" + ) + # At this point, no backends are available to handle the call with + # the input graph types, but if the input graphs are compatible + # nx.Graph instances, fall back to networkx without converting. + return self.orig_func(*args, **kwargs) + + # We may generalize fallback configuration as e.g. `nx.config.backend_fallback` + if nx.config.fallback_to_nx or not graph_backend_names: + # Use "networkx" by default if there are no inputs from backends. + # For example, graph generators should probably return NetworkX graphs + # instead of raising NotImplementedError. + backend_fallback = ["networkx"] + else: + backend_fallback = [] + + # ########################## + # # How this behaves today # + # ########################## + # + # The prose below describes the implementation and a *possible* way to + # generalize "networkx" as "just another backend". The code is structured + # to perhaps someday support backend-to-backend conversions (including + # simply passing objects from one backend directly to another backend; + # the dispatch machinery does not necessarily need to perform conversions), + # but since backend-to-backend matching is not yet supported, the following + # code is merely a convenient way to implement dispatch behaviors that have + # been carefully developed since NetworkX 3.0 and to include falling back + # to the default NetworkX implementation. + # + # The current behavior for functions that don't mutate input graphs: + # + # 1. If backend is specified by `backend=` keyword, use it (done above). + # 2. If input is from a backend other than "networkx", try to use it. + # - Note: if present, "networkx" graphs will be converted to the backend. + # 3. If input is from "networkx" (or no backend), try to use backends from + # `backend_priority` before running with the default "networkx" implementation. + # 4. If configured, "fall back" and run with the default "networkx" implementation. + # + # ################################################ + # # How this is implemented and may work someday # + # ################################################ + # + # Let's determine the order of backends we should try according + # to `backend_priority`, `backend_fallback`, and input backends. + # There are two† dimensions of priorities to consider: + # backend_priority > unspecified > backend_fallback + # and + # backend of an input > not a backend of an input + # These are combined to form five groups of priorities as such: + # + # input ~input + # +-------+-------+ + # backend_priority | 1 | 2 | + # unspecified | 3 | N/A | (if only 1) + # backend_fallback | 4 | 5 | + # +-------+-------+ + # + # This matches the behaviors we developed in versions 3.0 to 3.2, it + # ought to cover virtually all use cases we expect, and I (@eriknw) don't + # think it can be done any simpler (although it can be generalized further + # and made to be more complicated to capture 100% of *possible* use cases). + # Some observations: + # + # 1. If an input is in `backend_priority`, it will be used before trying a + # backend that is higher priority in `backend_priority` and not an input. + # 2. To prioritize converting from one backend to another even if both implement + # a function, list one in `backend_priority` and one in `backend_fallback`. + # 3. To disable conversions, set `backend_priority` and `backend_fallback` to []. + # + # †: There is actually a third dimension of priorities: + # should_run == True > should_run == False + # Backends with `can_run == True` and `should_run == False` are tried last. + # + seen = set() + group1 = [] # In backend_priority, and an input + group2 = [] # In backend_priority, but not an input + for name in backend_priority: + if name in seen: + continue + seen.add(name) + if name in graph_backend_names: + group1.append(name) + else: + group2.append(name) + group4 = [] # In backend_fallback, and an input + group5 = [] # In backend_fallback, but not an input + for name in backend_fallback: + if name in seen: + continue + seen.add(name) + if name in graph_backend_names: + group4.append(name) + else: + group5.append(name) + # An input, but not in backend_priority or backend_fallback. + group3 = graph_backend_names - seen + if len(group3) > 1: + # `group3` backends are not configured for automatic conversion or fallback. + # There are at least two issues if this group contains multiple backends: + # + # 1. How should we prioritize them? We have no good way to break ties. + # Although we could arbitrarily choose alphabetical or left-most, + # let's follow the Zen of Python and refuse the temptation to guess. + # 2. We probably shouldn't automatically convert to these backends, + # because we are not configured to do so. + # + # (2) is important to allow disabling all conversions by setting both + # `nx.config.backend_priority` and `nx.config.backend_fallback` to []. + # + # If there is a single backend in `group3`, then giving it priority over + # the fallback backends is what is generally expected. For example, this + # allows input graphs of `backend_fallback` backends (such as "networkx") + # to be converted to, and run with, the unspecified backend. + _logger.debug( + "Call to `%s' has inputs from multiple backends, %s, that " + "have no priority set in `nx.config.backend_priority`, " + "so automatic conversions to " + "these backends will not be attempted.", + self.name, + group3, + ) + group3 = () + + try_order = list(itertools.chain(group1, group2, group3, group4, group5)) + if len(try_order) > 1: + # Should we consider adding an option for more verbose logging? + # For example, we could explain the order of `try_order` in detail. + _logger.debug( + "Call to `%s' has inputs from %s backends, and will try to use " + "backends in the following order: %s", + self.name, + graph_backend_names or "no", + try_order, + ) + backends_to_try_again = [] + for is_not_first, backend_name in enumerate(try_order): + if is_not_first: + _logger.debug("Trying next backend: '%s'", backend_name) + try: + if not graph_backend_names or graph_backend_names == {backend_name}: + if self._can_backend_run(backend_name, args, kwargs): + return self._call_with_backend(backend_name, args, kwargs) + elif self._can_convert( + backend_name, graph_backend_names + ) and self._can_backend_run(backend_name, args, kwargs): + if self._should_backend_run(backend_name, args, kwargs): + rv = self._convert_and_call( + backend_name, graph_backend_names, args, kwargs + ) + if ( + self._returns_graph + and graph_backend_names + and backend_name not in graph_backend_names + ): + # If the function has graph inputs and graph output, we try + # to make it so the backend of the return type will match the + # backend of the input types. In case this is not possible, + # let's tell the user that the backend of the return graph + # has changed. Perhaps we could try to convert back, but + # "fallback" backends for graph generators should typically + # be compatible with NetworkX graphs. + _logger.debug( + "Call to `%s' is returning a graph from a different " + "backend! It has inputs from %s backends, but ran with " + "'%s' backend and is returning graph from '%s' backend", + self.name, + graph_backend_names, + backend_name, + backend_name, + ) + return rv + # `should_run` is False, but `can_run` is True, so try again later + backends_to_try_again.append(backend_name) + except NotImplementedError as exc: + _logger.debug( + "Backend '%s' raised when calling `%s': %s", + backend_name, + self.name, + exc, + ) + + # We are about to fail. Let's try backends with can_run=True and should_run=False. + # This is unlikely to help today since we try to run with "networkx" before this. + for backend_name in backends_to_try_again: + _logger.debug( + "Trying backend: '%s' (ignoring `should_run=False`)", backend_name + ) + try: + rv = self._convert_and_call( + backend_name, graph_backend_names, args, kwargs + ) + if ( + self._returns_graph + and graph_backend_names + and backend_name not in graph_backend_names + ): + _logger.debug( + "Call to `%s' is returning a graph from a different " + "backend! It has inputs from %s backends, but ran with " + "'%s' backend and is returning graph from '%s' backend", + self.name, + graph_backend_names, + backend_name, + backend_name, + ) + return rv + except NotImplementedError as exc: + _logger.debug( + "Backend '%s' raised when calling `%s': %s", + backend_name, + self.name, + exc, + ) + # As a final effort, we could try to convert and run with `group3` backends + # that we discarded when `len(group3) > 1`, but let's not consider doing + # so until there is a reasonable request for it. + + if len(unspecified_backends := graph_backend_names - seen) > 1: + raise TypeError( + f"Unable to convert inputs from {graph_backend_names} backends and " + f"run `{self.name}'. NetworkX is configured to automatically convert " + f"to {try_order} backends. To remedy this, you may enable automatic " + f"conversion to {unspecified_backends} backends by adding them to " + "`nx.config.backend_priority`, or you " + "may specify a backend to use with the `backend=` keyword argument." + ) + raise NotImplementedError( + f"`{self.name}' is not implemented by {try_order} backends. To remedy " + "this, you may enable automatic conversion to more backends (including " + "'networkx') by adding them to `nx.config.backend_priority`, " + "or you may specify a backend to use with " + "the `backend=` keyword argument." + ) + + def _will_call_mutate_input(self, args, kwargs): + return (mutates_input := self.mutates_input) and ( + mutates_input is True + or any( + # If `mutates_input` begins with "not ", then assume the argument is bool, + # otherwise treat it as a node or edge attribute if it's not None. + not ( + args[arg_pos] + if len(args) > arg_pos + # This assumes that e.g. `copy=True` is the default + else kwargs.get(arg_name[4:], True) + ) + if arg_name.startswith("not ") + else (args[arg_pos] if len(args) > arg_pos else kwargs.get(arg_name)) + is not None + for arg_name, arg_pos in mutates_input.items() + ) + ) + + def _can_convert(self, backend_name, graph_backend_names): + # Backend-to-backend conversion not supported yet. + # We can only convert to and from networkx. + rv = backend_name == "networkx" or graph_backend_names.issubset( + {"networkx", backend_name} + ) + if not rv: + _logger.debug( + "Unable to convert from %s backends to '%s' backend", + graph_backend_names, + backend_name, + ) + return rv + + def _does_backend_have(self, backend_name): + """Does the specified backend have this algorithm?""" + if backend_name == "networkx": + return True + # Inspect the backend; don't trust metadata used to create `self.backends` + backend = _load_backend(backend_name) + return hasattr(backend, self.name) + + def _can_backend_run(self, backend_name, args, kwargs): + """Can the specified backend run this algorithm with these arguments?""" + if backend_name == "networkx": + return True + backend = _load_backend(backend_name) + # `backend.can_run` and `backend.should_run` may return strings that describe + # why they can't or shouldn't be run. + if not hasattr(backend, self.name): + _logger.debug( + "Backend '%s' does not implement `%s'", backend_name, self.name + ) + return False + can_run = backend.can_run(self.name, args, kwargs) + if isinstance(can_run, str) or not can_run: + reason = f", because: {can_run}" if isinstance(can_run, str) else "" + _logger.debug( + "Backend '%s' can't run `%s` with arguments: %s%s", + backend_name, + self.name, + _LazyArgsRepr(self, args, kwargs), + reason, + ) + return False + return True + + def _should_backend_run(self, backend_name, args, kwargs): + """Should the specified backend run this algorithm with these arguments? + + Note that this does not check ``backend.can_run``. + """ + # `backend.can_run` and `backend.should_run` may return strings that describe + # why they can't or shouldn't be run. + if backend_name == "networkx": + return True + backend = _load_backend(backend_name) + should_run = backend.should_run(self.name, args, kwargs) + if isinstance(should_run, str) or not should_run: + reason = f", because: {should_run}" if isinstance(should_run, str) else "" + _logger.debug( + "Backend '%s' shouldn't run `%s` with arguments: %s%s", + backend_name, + self.name, + _LazyArgsRepr(self, args, kwargs), + reason, + ) + return False + return True + + def _convert_arguments(self, backend_name, args, kwargs, *, use_cache, mutations): + """Convert graph arguments to the specified backend. + + Returns + ------- + args tuple and kwargs dict + """ + bound = self.__signature__.bind(*args, **kwargs) + bound.apply_defaults() + if not self.graphs: + bound_kwargs = bound.kwargs + del bound_kwargs["backend"] + return bound.args, bound_kwargs + if backend_name == "networkx": + # `backend_interface.convert_from_nx` preserves everything + preserve_edge_attrs = preserve_node_attrs = preserve_graph_attrs = True + else: + preserve_edge_attrs = self.preserve_edge_attrs + preserve_node_attrs = self.preserve_node_attrs + preserve_graph_attrs = self.preserve_graph_attrs + edge_attrs = self.edge_attrs + node_attrs = self.node_attrs + # Convert graphs into backend graph-like object + # Include the edge and/or node labels if provided to the algorithm + if preserve_edge_attrs is False: + # e.g. `preserve_edge_attrs=False` + pass + elif preserve_edge_attrs is True: + # e.g. `preserve_edge_attrs=True` + edge_attrs = None + elif isinstance(preserve_edge_attrs, str): + if bound.arguments[preserve_edge_attrs] is True or callable( + bound.arguments[preserve_edge_attrs] + ): + # e.g. `preserve_edge_attrs="attr"` and `func(attr=True)` + # e.g. `preserve_edge_attrs="attr"` and `func(attr=myfunc)` + preserve_edge_attrs = True + edge_attrs = None + elif bound.arguments[preserve_edge_attrs] is False and ( + isinstance(edge_attrs, str) + and edge_attrs == preserve_edge_attrs + or isinstance(edge_attrs, dict) + and preserve_edge_attrs in edge_attrs + ): + # e.g. `preserve_edge_attrs="attr"` and `func(attr=False)` + # Treat `False` argument as meaning "preserve_edge_data=False" + # and not `False` as the edge attribute to use. + preserve_edge_attrs = False + edge_attrs = None + else: + # e.g. `preserve_edge_attrs="attr"` and `func(attr="weight")` + preserve_edge_attrs = False + # Else: e.g. `preserve_edge_attrs={"G": {"weight": 1}}` + + if edge_attrs is None: + # May have been set to None above b/c all attributes are preserved + pass + elif isinstance(edge_attrs, str): + if edge_attrs[0] == "[": + # e.g. `edge_attrs="[edge_attributes]"` (argument of list of attributes) + # e.g. `func(edge_attributes=["foo", "bar"])` + edge_attrs = { + edge_attr: 1 for edge_attr in bound.arguments[edge_attrs[1:-1]] + } + elif callable(bound.arguments[edge_attrs]): + # e.g. `edge_attrs="weight"` and `func(weight=myfunc)` + preserve_edge_attrs = True + edge_attrs = None + elif bound.arguments[edge_attrs] is not None: + # e.g. `edge_attrs="weight"` and `func(weight="foo")` (default of 1) + edge_attrs = {bound.arguments[edge_attrs]: 1} + elif self.name == "to_numpy_array" and hasattr( + bound.arguments["dtype"], "names" + ): + # Custom handling: attributes may be obtained from `dtype` + edge_attrs = { + edge_attr: 1 for edge_attr in bound.arguments["dtype"].names + } + else: + # e.g. `edge_attrs="weight"` and `func(weight=None)` + edge_attrs = None + else: + # e.g. `edge_attrs={"attr": "default"}` and `func(attr="foo", default=7)` + # e.g. `edge_attrs={"attr": 0}` and `func(attr="foo")` + edge_attrs = { + edge_attr: bound.arguments.get(val, 1) if isinstance(val, str) else val + for key, val in edge_attrs.items() + if (edge_attr := bound.arguments[key]) is not None + } + + if preserve_node_attrs is False: + # e.g. `preserve_node_attrs=False` + pass + elif preserve_node_attrs is True: + # e.g. `preserve_node_attrs=True` + node_attrs = None + elif isinstance(preserve_node_attrs, str): + if bound.arguments[preserve_node_attrs] is True or callable( + bound.arguments[preserve_node_attrs] + ): + # e.g. `preserve_node_attrs="attr"` and `func(attr=True)` + # e.g. `preserve_node_attrs="attr"` and `func(attr=myfunc)` + preserve_node_attrs = True + node_attrs = None + elif bound.arguments[preserve_node_attrs] is False and ( + isinstance(node_attrs, str) + and node_attrs == preserve_node_attrs + or isinstance(node_attrs, dict) + and preserve_node_attrs in node_attrs + ): + # e.g. `preserve_node_attrs="attr"` and `func(attr=False)` + # Treat `False` argument as meaning "preserve_node_data=False" + # and not `False` as the node attribute to use. Is this used? + preserve_node_attrs = False + node_attrs = None + else: + # e.g. `preserve_node_attrs="attr"` and `func(attr="weight")` + preserve_node_attrs = False + # Else: e.g. `preserve_node_attrs={"G": {"pos": None}}` + + if node_attrs is None: + # May have been set to None above b/c all attributes are preserved + pass + elif isinstance(node_attrs, str): + if node_attrs[0] == "[": + # e.g. `node_attrs="[node_attributes]"` (argument of list of attributes) + # e.g. `func(node_attributes=["foo", "bar"])` + node_attrs = { + node_attr: None for node_attr in bound.arguments[node_attrs[1:-1]] + } + elif callable(bound.arguments[node_attrs]): + # e.g. `node_attrs="weight"` and `func(weight=myfunc)` + preserve_node_attrs = True + node_attrs = None + elif bound.arguments[node_attrs] is not None: + # e.g. `node_attrs="weight"` and `func(weight="foo")` + node_attrs = {bound.arguments[node_attrs]: None} + else: + # e.g. `node_attrs="weight"` and `func(weight=None)` + node_attrs = None + else: + # e.g. `node_attrs={"attr": "default"}` and `func(attr="foo", default=7)` + # e.g. `node_attrs={"attr": 0}` and `func(attr="foo")` + node_attrs = { + node_attr: bound.arguments.get(val) if isinstance(val, str) else val + for key, val in node_attrs.items() + if (node_attr := bound.arguments[key]) is not None + } + + # It should be safe to assume that we either have networkx graphs or backend graphs. + # Future work: allow conversions between backends. + for gname in self.graphs: + if gname in self.list_graphs: + bound.arguments[gname] = [ + self._convert_graph( + backend_name, + g, + edge_attrs=edge_attrs, + node_attrs=node_attrs, + preserve_edge_attrs=preserve_edge_attrs, + preserve_node_attrs=preserve_node_attrs, + preserve_graph_attrs=preserve_graph_attrs, + graph_name=gname, + use_cache=use_cache, + mutations=mutations, + ) + if getattr(g, "__networkx_backend__", "networkx") != backend_name + else g + for g in bound.arguments[gname] + ] + else: + graph = bound.arguments[gname] + if graph is None: + if gname in self.optional_graphs: + continue + raise TypeError( + f"Missing required graph argument `{gname}` in {self.name} function" + ) + if isinstance(preserve_edge_attrs, dict): + preserve_edges = False + edges = preserve_edge_attrs.get(gname, edge_attrs) + else: + preserve_edges = preserve_edge_attrs + edges = edge_attrs + if isinstance(preserve_node_attrs, dict): + preserve_nodes = False + nodes = preserve_node_attrs.get(gname, node_attrs) + else: + preserve_nodes = preserve_node_attrs + nodes = node_attrs + if isinstance(preserve_graph_attrs, set): + preserve_graph = gname in preserve_graph_attrs + else: + preserve_graph = preserve_graph_attrs + if getattr(graph, "__networkx_backend__", "networkx") != backend_name: + bound.arguments[gname] = self._convert_graph( + backend_name, + graph, + edge_attrs=edges, + node_attrs=nodes, + preserve_edge_attrs=preserve_edges, + preserve_node_attrs=preserve_nodes, + preserve_graph_attrs=preserve_graph, + graph_name=gname, + use_cache=use_cache, + mutations=mutations, + ) + bound_kwargs = bound.kwargs + del bound_kwargs["backend"] + return bound.args, bound_kwargs + + def _convert_graph( + self, + backend_name, + graph, + *, + edge_attrs, + node_attrs, + preserve_edge_attrs, + preserve_node_attrs, + preserve_graph_attrs, + graph_name, + use_cache, + mutations, + ): + if ( + use_cache + and (nx_cache := getattr(graph, "__networkx_cache__", None)) is not None + ): + cache = nx_cache.setdefault("backends", {}).setdefault(backend_name, {}) + key = _get_cache_key( + edge_attrs=edge_attrs, + node_attrs=node_attrs, + preserve_edge_attrs=preserve_edge_attrs, + preserve_node_attrs=preserve_node_attrs, + preserve_graph_attrs=preserve_graph_attrs, + ) + compat_key, rv = _get_from_cache(cache, key, mutations=mutations) + if rv is not None: + if "cache" not in nx.config.warnings_to_ignore: + warnings.warn( + "Note: conversions to backend graphs are saved to cache " + "(`G.__networkx_cache__` on the original graph) by default." + "\n\nThis warning means the cached graph is being used " + f"for the {backend_name!r} backend in the " + f"call to {self.name}.\n\nFor the cache to be consistent " + "(i.e., correct), the input graph must not have been " + "manually mutated since the cached graph was created. " + "Examples of manually mutating the graph data structures " + "resulting in an inconsistent cache include:\n\n" + " >>> G[u][v][key] = val\n\n" + "and\n\n" + " >>> for u, v, d in G.edges(data=True):\n" + " ... d[key] = val\n\n" + "Using methods such as `G.add_edge(u, v, weight=val)` " + "will correctly clear the cache to keep it consistent. " + "You may also use `G.__networkx_cache__.clear()` to " + "manually clear the cache, or set `G.__networkx_cache__` " + "to None to disable caching for G. Enable or disable caching " + "globally via `nx.config.cache_converted_graphs` config.\n\n" + "To disable this warning:\n\n" + ' >>> nx.config.warnings_to_ignore.add("cache")\n' + ) + _logger.debug( + "Using cached converted graph (from '%s' to '%s' backend) " + "in call to `%s' for '%s' argument", + getattr(graph, "__networkx_backend__", None), + backend_name, + self.name, + graph_name, + ) + return rv + + if backend_name == "networkx": + # Perhaps we should check that "__networkx_backend__" attribute exists + # and return the original object if not. + if not hasattr(graph, "__networkx_backend__"): + _logger.debug( + "Unable to convert input to 'networkx' backend in call to `%s' for " + "'%s argument, because it is not from a backend (i.e., it does not " + "have `G.__networkx_backend__` attribute). Using the original " + "object: %s", + self.name, + graph_name, + graph, + ) + # This may fail, but let it fail in the networkx function + return graph + backend = _load_backend(graph.__networkx_backend__) + rv = backend.convert_to_nx(graph) + else: + backend = _load_backend(backend_name) + rv = backend.convert_from_nx( + graph, + edge_attrs=edge_attrs, + node_attrs=node_attrs, + preserve_edge_attrs=preserve_edge_attrs, + preserve_node_attrs=preserve_node_attrs, + # Always preserve graph attrs when we are caching b/c this should be + # cheap and may help prevent extra (unnecessary) conversions. Because + # we do this, we don't need `preserve_graph_attrs` in the cache key. + preserve_graph_attrs=preserve_graph_attrs or use_cache, + name=self.name, + graph_name=graph_name, + ) + if use_cache and nx_cache is not None and mutations is None: + _set_to_cache(cache, key, rv) + _logger.debug( + "Caching converted graph (from '%s' to '%s' backend) " + "in call to `%s' for '%s' argument", + getattr(graph, "__networkx_backend__", None), + backend_name, + self.name, + graph_name, + ) + + return rv + + def _call_with_backend(self, backend_name, args, kwargs, *, extra_message=None): + """Call this dispatchable function with a backend without converting inputs.""" + if backend_name == "networkx": + return self.orig_func(*args, **kwargs) + backend = _load_backend(backend_name) + _logger.debug( + "Using backend '%s' for call to `%s' with arguments: %s", + backend_name, + self.name, + _LazyArgsRepr(self, args, kwargs), + ) + try: + return getattr(backend, self.name)(*args, **kwargs) + except NotImplementedError as exc: + if extra_message is not None: + _logger.debug( + "Backend '%s' raised when calling `%s': %s", + backend_name, + self.name, + exc, + ) + raise NotImplementedError(extra_message) from exc + raise + + def _convert_and_call( + self, + backend_name, + input_backend_names, + args, + kwargs, + *, + extra_message=None, + mutations=None, + ): + """Call this dispatchable function with a backend after converting inputs. + + Parameters + ---------- + backend_name : str + input_backend_names : set[str] + args : arguments tuple + kwargs : keywords dict + extra_message : str, optional + Additional message to log if NotImplementedError is raised by backend. + mutations : list, optional + Used to clear objects gotten from cache if inputs will be mutated. + """ + if backend_name == "networkx": + func = self.orig_func + else: + backend = _load_backend(backend_name) + func = getattr(backend, self.name) + other_backend_names = input_backend_names - {backend_name} + _logger.debug( + "Converting input graphs from %s backend%s to '%s' backend for call to `%s'", + other_backend_names + if len(other_backend_names) > 1 + else f"'{next(iter(other_backend_names))}'", + "s" if len(other_backend_names) > 1 else "", + backend_name, + self.name, + ) + try: + converted_args, converted_kwargs = self._convert_arguments( + backend_name, + args, + kwargs, + use_cache=nx.config.cache_converted_graphs, + mutations=mutations, + ) + except NotImplementedError as exc: + # Only log the exception if we are adding an extra message + # because we don't want to lose any information. + _logger.debug( + "Failed to convert graphs from %s to '%s' backend for call to `%s'" + + ("" if extra_message is None else ": %s"), + input_backend_names, + backend_name, + self.name, + *(() if extra_message is None else (exc,)), + ) + if extra_message is not None: + raise NotImplementedError(extra_message) from exc + raise + if backend_name != "networkx": + _logger.debug( + "Using backend '%s' for call to `%s' with arguments: %s", + backend_name, + self.name, + _LazyArgsRepr(self, converted_args, converted_kwargs), + ) + try: + return func(*converted_args, **converted_kwargs) + except NotImplementedError as exc: + if extra_message is not None: + _logger.debug( + "Backend '%s' raised when calling `%s': %s", + backend_name, + self.name, + exc, + ) + raise NotImplementedError(extra_message) from exc + raise + + def _convert_and_call_for_tests( + self, backend_name, args, kwargs, *, fallback_to_nx=False + ): + """Call this dispatchable function with a backend; for use with testing.""" + backend = _load_backend(backend_name) + if not self._can_backend_run(backend_name, args, kwargs): + if fallback_to_nx or not self.graphs: + if fallback_to_nx: + _logger.debug( + "Falling back to use 'networkx' instead of '%s' backend " + "for call to `%s' with arguments: %s", + backend_name, + self.name, + _LazyArgsRepr(self, args, kwargs), + ) + return self.orig_func(*args, **kwargs) + + import pytest + + msg = f"'{self.name}' not implemented by {backend_name}" + if hasattr(backend, self.name): + msg += " with the given arguments" + pytest.xfail(msg) + + from collections.abc import Iterable, Iterator, Mapping + from copy import copy, deepcopy + from io import BufferedReader, BytesIO, StringIO, TextIOWrapper + from itertools import tee + from random import Random + + import numpy as np + from numpy.random import Generator, RandomState + from scipy.sparse import sparray + + # We sometimes compare the backend result to the original result, + # so we need two sets of arguments. We tee iterators and copy + # random state so that they may be used twice. + if not args: + args1 = args2 = args + else: + args1, args2 = zip( + *( + (arg, deepcopy(arg)) + if isinstance(arg, RandomState) + else (arg, copy(arg)) + if isinstance(arg, BytesIO | StringIO | Random | Generator) + else tee(arg) + if isinstance(arg, Iterator) + and not isinstance(arg, BufferedReader | TextIOWrapper) + else (arg, arg) + for arg in args + ) + ) + if not kwargs: + kwargs1 = kwargs2 = kwargs + else: + kwargs1, kwargs2 = zip( + *( + ((k, v), (k, deepcopy(v))) + if isinstance(v, RandomState) + else ((k, v), (k, copy(v))) + if isinstance(v, BytesIO | StringIO | Random | Generator) + else ((k, (teed := tee(v))[0]), (k, teed[1])) + if isinstance(v, Iterator) + and not isinstance(v, BufferedReader | TextIOWrapper) + else ((k, v), (k, v)) + for k, v in kwargs.items() + ) + ) + kwargs1 = dict(kwargs1) + kwargs2 = dict(kwargs2) + try: + converted_args, converted_kwargs = self._convert_arguments( + backend_name, args1, kwargs1, use_cache=False, mutations=None + ) + _logger.debug( + "Using backend '%s' for call to `%s' with arguments: %s", + backend_name, + self.name, + _LazyArgsRepr(self, converted_args, converted_kwargs), + ) + result = getattr(backend, self.name)(*converted_args, **converted_kwargs) + except NotImplementedError as exc: + if fallback_to_nx: + _logger.debug( + "Graph conversion failed; falling back to use 'networkx' instead " + "of '%s' backend for call to `%s'", + backend_name, + self.name, + ) + return self.orig_func(*args2, **kwargs2) + import pytest + + pytest.xfail( + exc.args[0] if exc.args else f"{self.name} raised {type(exc).__name__}" + ) + # Verify that `self._returns_graph` is correct. This compares the return type + # to the type expected from `self._returns_graph`. This handles tuple and list + # return types, but *does not* catch functions that yield graphs. + if ( + self._returns_graph + != ( + isinstance(result, nx.Graph) + or hasattr(result, "__networkx_backend__") + or isinstance(result, tuple | list) + and any( + isinstance(x, nx.Graph) or hasattr(x, "__networkx_backend__") + for x in result + ) + ) + and not ( + # May return Graph or None + self.name in {"check_planarity", "check_planarity_recursive"} + and any(x is None for x in result) + ) + and not ( + # May return Graph or dict + self.name in {"held_karp_ascent"} + and any(isinstance(x, dict) for x in result) + ) + and self.name + not in { + # yields graphs + "all_triads", + "general_k_edge_subgraphs", + # yields graphs or arrays + "nonisomorphic_trees", + } + ): + raise RuntimeError(f"`returns_graph` is incorrect for {self.name}") + + def check_result(val, depth=0): + if isinstance(val, np.number): + raise RuntimeError( + f"{self.name} returned a numpy scalar {val} ({type(val)}, depth={depth})" + ) + if isinstance(val, np.ndarray | sparray): + return + if isinstance(val, nx.Graph): + check_result(val._node, depth=depth + 1) + check_result(val._adj, depth=depth + 1) + return + if isinstance(val, Iterator): + raise NotImplementedError + if isinstance(val, Iterable) and not isinstance(val, str): + for x in val: + check_result(x, depth=depth + 1) + if isinstance(val, Mapping): + for x in val.values(): + check_result(x, depth=depth + 1) + + def check_iterator(it): + for val in it: + try: + check_result(val) + except RuntimeError as exc: + raise RuntimeError( + f"{self.name} returned a numpy scalar {val} ({type(val)})" + ) from exc + yield val + + if self.name in {"from_edgelist"}: + # numpy scalars are explicitly given as values in some tests + pass + elif isinstance(result, Iterator): + result = check_iterator(result) + else: + try: + check_result(result) + except RuntimeError as exc: + raise RuntimeError( + f"{self.name} returned a numpy scalar {result} ({type(result)})" + ) from exc + check_result(result) + + if self.name in { + "edmonds_karp", + "barycenter", + "contracted_edge", + "contracted_nodes", + "stochastic_graph", + "relabel_nodes", + "maximum_branching", + "incremental_closeness_centrality", + "minimal_branching", + "minimum_spanning_arborescence", + "recursive_simple_cycles", + "connected_double_edge_swap", + }: + # Special-case algorithms that mutate input graphs + bound = self.__signature__.bind(*converted_args, **converted_kwargs) + bound.apply_defaults() + bound2 = self.__signature__.bind(*args2, **kwargs2) + bound2.apply_defaults() + if self.name in { + "minimal_branching", + "minimum_spanning_arborescence", + "recursive_simple_cycles", + "connected_double_edge_swap", + }: + G1 = backend.convert_to_nx(bound.arguments["G"]) + G2 = bound2.arguments["G"] + G2._adj = G1._adj + if G2.is_directed(): + G2._pred = G1._pred + nx._clear_cache(G2) + elif self.name == "edmonds_karp": + R1 = backend.convert_to_nx(bound.arguments["residual"]) + R2 = bound2.arguments["residual"] + if R1 is not None and R2 is not None: + for k, v in R1.edges.items(): + R2.edges[k]["flow"] = v["flow"] + R2.graph.update(R1.graph) + nx._clear_cache(R2) + elif self.name == "barycenter" and bound.arguments["attr"] is not None: + G1 = backend.convert_to_nx(bound.arguments["G"]) + G2 = bound2.arguments["G"] + attr = bound.arguments["attr"] + for k, v in G1.nodes.items(): + G2.nodes[k][attr] = v[attr] + nx._clear_cache(G2) + elif ( + self.name in {"contracted_nodes", "contracted_edge"} + and not bound.arguments["copy"] + ): + # Edges and nodes changed; node "contraction" and edge "weight" attrs + G1 = backend.convert_to_nx(bound.arguments["G"]) + G2 = bound2.arguments["G"] + G2.__dict__.update(G1.__dict__) + nx._clear_cache(G2) + elif self.name == "stochastic_graph" and not bound.arguments["copy"]: + G1 = backend.convert_to_nx(bound.arguments["G"]) + G2 = bound2.arguments["G"] + for k, v in G1.edges.items(): + G2.edges[k]["weight"] = v["weight"] + nx._clear_cache(G2) + elif ( + self.name == "relabel_nodes" + and not bound.arguments["copy"] + or self.name in {"incremental_closeness_centrality"} + ): + G1 = backend.convert_to_nx(bound.arguments["G"]) + G2 = bound2.arguments["G"] + if G1 is G2: + return G2 + G2._node.clear() + G2._node.update(G1._node) + G2._adj.clear() + G2._adj.update(G1._adj) + if hasattr(G1, "_pred") and hasattr(G2, "_pred"): + G2._pred.clear() + G2._pred.update(G1._pred) + if hasattr(G1, "_succ") and hasattr(G2, "_succ"): + G2._succ.clear() + G2._succ.update(G1._succ) + nx._clear_cache(G2) + if self.name == "relabel_nodes": + return G2 + return backend.convert_to_nx(result) + + converted_result = backend.convert_to_nx(result) + if isinstance(converted_result, nx.Graph) and self.name not in { + "boykov_kolmogorov", + "preflow_push", + "quotient_graph", + "shortest_augmenting_path", + "spectral_graph_forge", + # We don't handle tempfile.NamedTemporaryFile arguments + "read_gml", + "read_graph6", + "read_sparse6", + # We don't handle io.BufferedReader or io.TextIOWrapper arguments + "bipartite_read_edgelist", + "read_adjlist", + "read_edgelist", + "read_graphml", + "read_multiline_adjlist", + "read_pajek", + "from_pydot", + "pydot_read_dot", + "agraph_read_dot", + # graph comparison fails b/c of nan values + "read_gexf", + }: + # For graph return types (e.g. generators), we compare that results are + # the same between the backend and networkx, then return the original + # networkx result so the iteration order will be consistent in tests. + G = self.orig_func(*args2, **kwargs2) + if not nx.utils.graphs_equal(G, converted_result): + assert G.number_of_nodes() == converted_result.number_of_nodes() + assert G.number_of_edges() == converted_result.number_of_edges() + assert G.graph == converted_result.graph + assert G.nodes == converted_result.nodes + assert G.adj == converted_result.adj + assert type(G) is type(converted_result) + raise AssertionError("Graphs are not equal") + return G + return converted_result + + def _make_doc(self): + """Generate the backends section at the end for functions having an alternate + backend implementation(s) using the `backend_info` entry-point.""" + + if not self.backends: + return self._orig_doc + lines = [ + "Backends", + "--------", + ] + for backend in sorted(self.backends): + info = backend_info[backend] + if "short_summary" in info: + lines.append(f"{backend} : {info['short_summary']}") + else: + lines.append(backend) + if "functions" not in info or self.name not in info["functions"]: + lines.append("") + continue + + func_info = info["functions"][self.name] + + # Renaming extra_docstring to additional_docs + if func_docs := ( + func_info.get("additional_docs") or func_info.get("extra_docstring") + ): + lines.extend( + f" {line}" if line else line for line in func_docs.split("\n") + ) + add_gap = True + else: + add_gap = False + + # Renaming extra_parameters to additional_parameters + if extra_parameters := ( + func_info.get("extra_parameters") + or func_info.get("additional_parameters") + ): + if add_gap: + lines.append("") + lines.append(" Additional parameters:") + for param in sorted(extra_parameters): + lines.append(f" {param}") + if desc := extra_parameters[param]: + lines.append(f" {desc}") + lines.append("") + else: + lines.append("") + + if func_url := func_info.get("url"): + lines.append(f"[`Source <{func_url}>`_]") + lines.append("") + + lines.pop() # Remove last empty line + to_add = "\n ".join(lines) + if not self._orig_doc: + return f"The original docstring for {self.name} was empty.\n\n {to_add}" + return f"{self._orig_doc.rstrip()}\n\n {to_add}" + + def __reduce__(self): + """Allow this object to be serialized with pickle. + + This uses the global registry `_registered_algorithms` to deserialize. + """ + return _restore_dispatchable, (self.name,) + + +def _restore_dispatchable(name): + return _registered_algorithms[name].__wrapped__ + + +def _get_cache_key( + *, + edge_attrs, + node_attrs, + preserve_edge_attrs, + preserve_node_attrs, + preserve_graph_attrs, +): + """Return key used by networkx caching given arguments for ``convert_from_nx``.""" + # edge_attrs: dict | None + # node_attrs: dict | None + # preserve_edge_attrs: bool (False if edge_attrs is not None) + # preserve_node_attrs: bool (False if node_attrs is not None) + return ( + frozenset(edge_attrs.items()) + if edge_attrs is not None + else preserve_edge_attrs, + frozenset(node_attrs.items()) + if node_attrs is not None + else preserve_node_attrs, + ) + + +def _get_from_cache(cache, key, *, backend_name=None, mutations=None): + """Search the networkx cache for a graph that is compatible with ``key``. + + Parameters + ---------- + cache : dict + If ``backend_name`` is given, then this is treated as ``G.__networkx_cache__``, + but if ``backend_name`` is None, then this is treated as the resolved inner + cache such as ``G.__networkx_cache__["backends"][backend_name]``. + key : tuple + Cache key from ``_get_cache_key``. + backend_name : str, optional + Name of the backend to control how ``cache`` is interpreted. + mutations : list, optional + Used internally to clear objects gotten from cache if inputs will be mutated. + + Returns + ------- + tuple or None + The key of the compatible graph found in the cache. + graph or None + A compatible graph or None. + """ + if backend_name is not None: + cache = cache.get("backends", {}).get(backend_name, {}) + if not cache: + return None, None + + # Do a simple search for a cached graph with compatible data. + # For example, if we need a single attribute, then it's okay + # to use a cached graph that preserved all attributes. + # This looks for an exact match first. + edge_key, node_key = key + for compat_key in itertools.product( + (edge_key, True) if edge_key is not True else (True,), + (node_key, True) if node_key is not True else (True,), + ): + if (rv := cache.get(compat_key)) is not None: + if mutations is not None: + # Remove this item from the cache (after all conversions) if + # the call to this dispatchable function will mutate an input. + mutations.append((cache, compat_key)) + return compat_key, rv + if edge_key is not True and node_key is not True: + # Iterate over the items in `cache` to see if any are compatible. + # For example, if no edge attributes are needed, then a graph + # with any edge attribute will suffice. We use the same logic + # below (but switched) to clear unnecessary items from the cache. + # Use `list(cache.items())` to be thread-safe. + for (ekey, nkey), graph in list(cache.items()): + if edge_key is False or ekey is True: + pass # Cache works for edge data! + elif edge_key is True or ekey is False or not edge_key.issubset(ekey): + continue # Cache missing required edge data; does not work + if node_key is False or nkey is True: + pass # Cache works for node data! + elif node_key is True or nkey is False or not node_key.issubset(nkey): + continue # Cache missing required node data; does not work + if mutations is not None: + # Remove this item from the cache (after all conversions) if + # the call to this dispatchable function will mutate an input. + mutations.append((cache, (ekey, nkey))) + return (ekey, nkey), graph + return None, None + + +def _set_to_cache(cache, key, graph, *, backend_name=None): + """Set a backend graph to the cache, and remove unnecessary cached items. + + Parameters + ---------- + cache : dict + If ``backend_name`` is given, then this is treated as ``G.__networkx_cache__``, + but if ``backend_name`` is None, then this is treated as the resolved inner + cache such as ``G.__networkx_cache__["backends"][backend_name]``. + key : tuple + Cache key from ``_get_cache_key``. + graph : graph + backend_name : str, optional + Name of the backend to control how ``cache`` is interpreted. + + Returns + ------- + dict + The items that were removed from the cache. + """ + if backend_name is not None: + cache = cache.setdefault("backends", {}).setdefault(backend_name, {}) + # Remove old cached items that are no longer necessary since they + # are dominated/subsumed/outdated by what was just calculated. + # This uses the same logic as above, but with keys switched. + # Also, don't update the cache here if the call will mutate an input. + removed = {} + edge_key, node_key = key + cache[key] = graph # Set at beginning to be thread-safe + for cur_key in list(cache): + if cur_key == key: + continue + ekey, nkey = cur_key + if ekey is False or edge_key is True: + pass + elif ekey is True or edge_key is False or not ekey.issubset(edge_key): + continue + if nkey is False or node_key is True: + pass + elif nkey is True or node_key is False or not nkey.issubset(node_key): + continue + # Use pop instead of del to try to be thread-safe + if (graph := cache.pop(cur_key, None)) is not None: + removed[cur_key] = graph + return removed + + +class _LazyArgsRepr: + """Simple wrapper to display arguments of dispatchable functions in logging calls.""" + + def __init__(self, func, args, kwargs): + self.func = func + self.args = args + self.kwargs = kwargs + self.value = None + + def __repr__(self): + if self.value is None: + bound = self.func.__signature__.bind_partial(*self.args, **self.kwargs) + inner = ", ".join(f"{key}={val!r}" for key, val in bound.arguments.items()) + self.value = f"({inner})" + return self.value + + +if os.environ.get("_NETWORKX_BUILDING_DOCS_"): + # When building docs with Sphinx, use the original function with the + # dispatched __doc__, b/c Sphinx renders normal Python functions better. + # This doesn't show e.g. `*, backend=None, **backend_kwargs` in the + # signatures, which is probably okay. It does allow the docstring to be + # updated based on the installed backends. + _orig_dispatchable = _dispatchable + + def _dispatchable(func=None, **kwargs): # type: ignore[no-redef] + if func is None: + return partial(_dispatchable, **kwargs) + dispatched_func = _orig_dispatchable(func, **kwargs) + func.__doc__ = dispatched_func.__doc__ + return func + + _dispatchable.__doc__ = _orig_dispatchable.__new__.__doc__ # type: ignore[method-assign,assignment] + _sig = inspect.signature(_orig_dispatchable.__new__) + _dispatchable.__signature__ = _sig.replace( # type: ignore[method-assign,assignment] + parameters=[v for k, v in _sig.parameters.items() if k != "cls"] + ) diff --git a/janus/lib/python3.10/site-packages/networkx/utils/heaps.py b/janus/lib/python3.10/site-packages/networkx/utils/heaps.py new file mode 100644 index 0000000000000000000000000000000000000000..3db27906314924380a8a87f2dfd3a81292ffbb9f --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/utils/heaps.py @@ -0,0 +1,340 @@ +""" +Min-heaps. +""" + +from heapq import heappop, heappush +from itertools import count + +import networkx as nx + +__all__ = ["MinHeap", "PairingHeap", "BinaryHeap"] + + +class MinHeap: + """Base class for min-heaps. + + A MinHeap stores a collection of key-value pairs ordered by their values. + It supports querying the minimum pair, inserting a new pair, decreasing the + value in an existing pair and deleting the minimum pair. + """ + + class _Item: + """Used by subclassess to represent a key-value pair.""" + + __slots__ = ("key", "value") + + def __init__(self, key, value): + self.key = key + self.value = value + + def __repr__(self): + return repr((self.key, self.value)) + + def __init__(self): + """Initialize a new min-heap.""" + self._dict = {} + + def min(self): + """Query the minimum key-value pair. + + Returns + ------- + key, value : tuple + The key-value pair with the minimum value in the heap. + + Raises + ------ + NetworkXError + If the heap is empty. + """ + raise NotImplementedError + + def pop(self): + """Delete the minimum pair in the heap. + + Returns + ------- + key, value : tuple + The key-value pair with the minimum value in the heap. + + Raises + ------ + NetworkXError + If the heap is empty. + """ + raise NotImplementedError + + def get(self, key, default=None): + """Returns the value associated with a key. + + Parameters + ---------- + key : hashable object + The key to be looked up. + + default : object + Default value to return if the key is not present in the heap. + Default value: None. + + Returns + ------- + value : object. + The value associated with the key. + """ + raise NotImplementedError + + def insert(self, key, value, allow_increase=False): + """Insert a new key-value pair or modify the value in an existing + pair. + + Parameters + ---------- + key : hashable object + The key. + + value : object comparable with existing values. + The value. + + allow_increase : bool + Whether the value is allowed to increase. If False, attempts to + increase an existing value have no effect. Default value: False. + + Returns + ------- + decreased : bool + True if a pair is inserted or the existing value is decreased. + """ + raise NotImplementedError + + def __nonzero__(self): + """Returns whether the heap if empty.""" + return bool(self._dict) + + def __bool__(self): + """Returns whether the heap if empty.""" + return bool(self._dict) + + def __len__(self): + """Returns the number of key-value pairs in the heap.""" + return len(self._dict) + + def __contains__(self, key): + """Returns whether a key exists in the heap. + + Parameters + ---------- + key : any hashable object. + The key to be looked up. + """ + return key in self._dict + + +class PairingHeap(MinHeap): + """A pairing heap.""" + + class _Node(MinHeap._Item): + """A node in a pairing heap. + + A tree in a pairing heap is stored using the left-child, right-sibling + representation. + """ + + __slots__ = ("left", "next", "prev", "parent") + + def __init__(self, key, value): + super().__init__(key, value) + # The leftmost child. + self.left = None + # The next sibling. + self.next = None + # The previous sibling. + self.prev = None + # The parent. + self.parent = None + + def __init__(self): + """Initialize a pairing heap.""" + super().__init__() + self._root = None + + def min(self): + if self._root is None: + raise nx.NetworkXError("heap is empty.") + return (self._root.key, self._root.value) + + def pop(self): + if self._root is None: + raise nx.NetworkXError("heap is empty.") + min_node = self._root + self._root = self._merge_children(self._root) + del self._dict[min_node.key] + return (min_node.key, min_node.value) + + def get(self, key, default=None): + node = self._dict.get(key) + return node.value if node is not None else default + + def insert(self, key, value, allow_increase=False): + node = self._dict.get(key) + root = self._root + if node is not None: + if value < node.value: + node.value = value + if node is not root and value < node.parent.value: + self._cut(node) + self._root = self._link(root, node) + return True + elif allow_increase and value > node.value: + node.value = value + child = self._merge_children(node) + # Nonstandard step: Link the merged subtree with the root. See + # below for the standard step. + if child is not None: + self._root = self._link(self._root, child) + # Standard step: Perform a decrease followed by a pop as if the + # value were the smallest in the heap. Then insert the new + # value into the heap. + # if node is not root: + # self._cut(node) + # if child is not None: + # root = self._link(root, child) + # self._root = self._link(root, node) + # else: + # self._root = (self._link(node, child) + # if child is not None else node) + return False + else: + # Insert a new key. + node = self._Node(key, value) + self._dict[key] = node + self._root = self._link(root, node) if root is not None else node + return True + + def _link(self, root, other): + """Link two nodes, making the one with the smaller value the parent of + the other. + """ + if other.value < root.value: + root, other = other, root + next = root.left + other.next = next + if next is not None: + next.prev = other + other.prev = None + root.left = other + other.parent = root + return root + + def _merge_children(self, root): + """Merge the subtrees of the root using the standard two-pass method. + The resulting subtree is detached from the root. + """ + node = root.left + root.left = None + if node is not None: + link = self._link + # Pass 1: Merge pairs of consecutive subtrees from left to right. + # At the end of the pass, only the prev pointers of the resulting + # subtrees have meaningful values. The other pointers will be fixed + # in pass 2. + prev = None + while True: + next = node.next + if next is None: + node.prev = prev + break + next_next = next.next + node = link(node, next) + node.prev = prev + prev = node + if next_next is None: + break + node = next_next + # Pass 2: Successively merge the subtrees produced by pass 1 from + # right to left with the rightmost one. + prev = node.prev + while prev is not None: + prev_prev = prev.prev + node = link(prev, node) + prev = prev_prev + # Now node can become the new root. Its has no parent nor siblings. + node.prev = None + node.next = None + node.parent = None + return node + + def _cut(self, node): + """Cut a node from its parent.""" + prev = node.prev + next = node.next + if prev is not None: + prev.next = next + else: + node.parent.left = next + node.prev = None + if next is not None: + next.prev = prev + node.next = None + node.parent = None + + +class BinaryHeap(MinHeap): + """A binary heap.""" + + def __init__(self): + """Initialize a binary heap.""" + super().__init__() + self._heap = [] + self._count = count() + + def min(self): + dict = self._dict + if not dict: + raise nx.NetworkXError("heap is empty") + heap = self._heap + pop = heappop + # Repeatedly remove stale key-value pairs until a up-to-date one is + # met. + while True: + value, _, key = heap[0] + if key in dict and value == dict[key]: + break + pop(heap) + return (key, value) + + def pop(self): + dict = self._dict + if not dict: + raise nx.NetworkXError("heap is empty") + heap = self._heap + pop = heappop + # Repeatedly remove stale key-value pairs until a up-to-date one is + # met. + while True: + value, _, key = heap[0] + pop(heap) + if key in dict and value == dict[key]: + break + del dict[key] + return (key, value) + + def get(self, key, default=None): + return self._dict.get(key, default) + + def insert(self, key, value, allow_increase=False): + dict = self._dict + if key in dict: + old_value = dict[key] + if value < old_value or (allow_increase and value > old_value): + # Since there is no way to efficiently obtain the location of a + # key-value pair in the heap, insert a new pair even if ones + # with the same key may already be present. Deem the old ones + # as stale and skip them when the minimum pair is queried. + dict[key] = value + heappush(self._heap, (value, next(self._count), key)) + return value < old_value + return False + else: + dict[key] = value + heappush(self._heap, (value, next(self._count), key)) + return True diff --git a/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_backends.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_backends.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..0e88738e926e2632ab2d61a99b52c30b27652cee Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_backends.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_config.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_config.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..911ce2378ea17efc65ec327ba2c53fe63132bc7f Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_config.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_unionfind.cpython-310.pyc b/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_unionfind.cpython-310.pyc new file mode 100644 index 0000000000000000000000000000000000000000..1de2fd57a9b23c3966f6e76689809e64c5ab121e Binary files /dev/null and b/janus/lib/python3.10/site-packages/networkx/utils/tests/__pycache__/test_unionfind.cpython-310.pyc differ diff --git a/janus/lib/python3.10/site-packages/networkx/utils/tests/test_backends.py b/janus/lib/python3.10/site-packages/networkx/utils/tests/test_backends.py new file mode 100644 index 0000000000000000000000000000000000000000..ad006f00f7a9b5f4a5140827c5a9dce1eb0530c3 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/utils/tests/test_backends.py @@ -0,0 +1,170 @@ +import pickle + +import pytest + +import networkx as nx + +sp = pytest.importorskip("scipy") +pytest.importorskip("numpy") + + +def test_dispatch_kwds_vs_args(): + G = nx.path_graph(4) + nx.pagerank(G) + nx.pagerank(G=G) + with pytest.raises(TypeError): + nx.pagerank() + + +def test_pickle(): + count = 0 + for name, func in nx.utils.backends._registered_algorithms.items(): + pickled = pickle.dumps(func.__wrapped__) + assert pickle.loads(pickled) is func.__wrapped__ + try: + # Some functions can't be pickled, but it's not b/c of _dispatchable + pickled = pickle.dumps(func) + except pickle.PicklingError: + continue + assert pickle.loads(pickled) is func + count += 1 + assert count > 0 + assert pickle.loads(pickle.dumps(nx.inverse_line_graph)) is nx.inverse_line_graph + + +@pytest.mark.skipif( + "not nx.config.backend_priority.algos " + "or nx.config.backend_priority.algos[0] != 'nx_loopback'" +) +def test_graph_converter_needs_backend(): + # When testing, `nx.from_scipy_sparse_array` will *always* call the backend + # implementation if it's implemented. If `backend=` isn't given, then the result + # will be converted back to NetworkX via `convert_to_nx`. + # If not testing, then calling `nx.from_scipy_sparse_array` w/o `backend=` will + # always call the original version. `backend=` is *required* to call the backend. + from networkx.classes.tests.dispatch_interface import ( + LoopbackBackendInterface, + LoopbackGraph, + ) + + A = sp.sparse.coo_array([[0, 3, 2], [3, 0, 1], [2, 1, 0]]) + + side_effects = [] + + def from_scipy_sparse_array(self, *args, **kwargs): + side_effects.append(1) # Just to prove this was called + return self.convert_from_nx( + self.__getattr__("from_scipy_sparse_array")(*args, **kwargs), + preserve_edge_attrs=True, + preserve_node_attrs=True, + preserve_graph_attrs=True, + ) + + @staticmethod + def convert_to_nx(obj, *, name=None): + if type(obj) is nx.Graph: + return obj + return nx.Graph(obj) + + # *This mutates LoopbackBackendInterface!* + orig_convert_to_nx = LoopbackBackendInterface.convert_to_nx + LoopbackBackendInterface.convert_to_nx = convert_to_nx + LoopbackBackendInterface.from_scipy_sparse_array = from_scipy_sparse_array + + try: + assert side_effects == [] + assert type(nx.from_scipy_sparse_array(A)) is nx.Graph + assert side_effects == [1] + assert ( + type(nx.from_scipy_sparse_array(A, backend="nx_loopback")) is LoopbackGraph + ) + assert side_effects == [1, 1] + # backend="networkx" is default implementation + assert type(nx.from_scipy_sparse_array(A, backend="networkx")) is nx.Graph + assert side_effects == [1, 1] + finally: + LoopbackBackendInterface.convert_to_nx = staticmethod(orig_convert_to_nx) + del LoopbackBackendInterface.from_scipy_sparse_array + with pytest.raises(ImportError, match="backend is not installed"): + nx.from_scipy_sparse_array(A, backend="bad-backend-name") + + +@pytest.mark.skipif( + "not nx.config.backend_priority.algos " + "or nx.config.backend_priority.algos[0] != 'nx_loopback'" +) +def test_networkx_backend(): + """Test using `backend="networkx"` in a dispatchable function.""" + # (Implementing this test is harder than it should be) + from networkx.classes.tests.dispatch_interface import ( + LoopbackBackendInterface, + LoopbackGraph, + ) + + G = LoopbackGraph() + G.add_edges_from([(0, 1), (1, 2), (1, 3), (2, 4)]) + + @staticmethod + def convert_to_nx(obj, *, name=None): + if isinstance(obj, LoopbackGraph): + new_graph = nx.Graph() + new_graph.__dict__.update(obj.__dict__) + return new_graph + return obj + + # *This mutates LoopbackBackendInterface!* + # This uses the same trick as in the previous test. + orig_convert_to_nx = LoopbackBackendInterface.convert_to_nx + LoopbackBackendInterface.convert_to_nx = convert_to_nx + try: + G2 = nx.ego_graph(G, 0, backend="networkx") + assert type(G2) is nx.Graph + finally: + LoopbackBackendInterface.convert_to_nx = staticmethod(orig_convert_to_nx) + + +def test_dispatchable_are_functions(): + assert type(nx.pagerank) is type(nx.pagerank.orig_func) + + +@pytest.mark.skipif("not nx.utils.backends.backends") +def test_mixing_backend_graphs(): + from networkx.classes.tests import dispatch_interface + + G = nx.Graph() + G.add_edge(1, 2) + G.add_edge(2, 3) + H = nx.Graph() + H.add_edge(2, 3) + rv = nx.intersection(G, H) + assert set(nx.intersection(G, H)) == {2, 3} + G2 = dispatch_interface.convert(G) + H2 = dispatch_interface.convert(H) + if "nx_loopback" in nx.config.backend_priority: + # Auto-convert + assert set(nx.intersection(G2, H)) == {2, 3} + assert set(nx.intersection(G, H2)) == {2, 3} + elif not nx.config.backend_priority and "nx_loopback" not in nx.config.backends: + # G2 and H2 are backend objects for a backend that is not registered! + with pytest.raises(ImportError, match="backend is not installed"): + nx.intersection(G2, H) + with pytest.raises(ImportError, match="backend is not installed"): + nx.intersection(G, H2) + # It would be nice to test passing graphs from *different* backends, + # but we are not set up to do this yet. + + +def test_bad_backend_name(): + """Using `backend=` raises with unknown backend even if there are no backends.""" + with pytest.raises( + ImportError, match="'this_backend_does_not_exist' backend is not installed" + ): + nx.null_graph(backend="this_backend_does_not_exist") + + +def test_fallback_to_nx(): + with pytest.warns(DeprecationWarning, match="_fallback_to_nx"): + # Check as class property + assert nx._dispatchable._fallback_to_nx == nx.config.fallback_to_nx + # Check as instance property + assert nx.pagerank.__wrapped__._fallback_to_nx == nx.config.fallback_to_nx diff --git a/janus/lib/python3.10/site-packages/networkx/utils/tests/test_config.py b/janus/lib/python3.10/site-packages/networkx/utils/tests/test_config.py new file mode 100644 index 0000000000000000000000000000000000000000..7416b0ac18e9f8852ad9b5989a2edcb55c7c1638 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/utils/tests/test_config.py @@ -0,0 +1,231 @@ +import collections +import pickle + +import pytest + +import networkx as nx +from networkx.utils.configs import BackendPriorities, Config + + +# Define this at module level so we can test pickling +class ExampleConfig(Config): + """Example configuration.""" + + x: int + y: str + + def _on_setattr(self, key, value): + if key == "x" and value <= 0: + raise ValueError("x must be positive") + if key == "y" and not isinstance(value, str): + raise TypeError("y must be a str") + return value + + +class EmptyConfig(Config): + pass + + +@pytest.mark.parametrize("cfg", [EmptyConfig(), Config()]) +def test_config_empty(cfg): + assert dir(cfg) == [] + with pytest.raises(AttributeError): + cfg.x = 1 + with pytest.raises(KeyError): + cfg["x"] = 1 + with pytest.raises(AttributeError): + cfg.x + with pytest.raises(KeyError): + cfg["x"] + assert len(cfg) == 0 + assert "x" not in cfg + assert cfg == cfg + assert cfg.get("x", 2) == 2 + assert set(cfg.keys()) == set() + assert set(cfg.values()) == set() + assert set(cfg.items()) == set() + cfg2 = pickle.loads(pickle.dumps(cfg)) + assert cfg == cfg2 + assert isinstance(cfg, collections.abc.Collection) + assert isinstance(cfg, collections.abc.Mapping) + + +def test_config_subclass(): + with pytest.raises(TypeError, match="missing 2 required keyword-only"): + ExampleConfig() + with pytest.raises(ValueError, match="x must be positive"): + ExampleConfig(x=0, y="foo") + with pytest.raises(TypeError, match="unexpected keyword"): + ExampleConfig(x=1, y="foo", z="bad config") + with pytest.raises(TypeError, match="unexpected keyword"): + EmptyConfig(z="bad config") + cfg = ExampleConfig(x=1, y="foo") + assert cfg.x == 1 + assert cfg["x"] == 1 + assert cfg["y"] == "foo" + assert cfg.y == "foo" + assert "x" in cfg + assert "y" in cfg + assert "z" not in cfg + assert len(cfg) == 2 + assert set(iter(cfg)) == {"x", "y"} + assert set(cfg.keys()) == {"x", "y"} + assert set(cfg.values()) == {1, "foo"} + assert set(cfg.items()) == {("x", 1), ("y", "foo")} + assert dir(cfg) == ["x", "y"] + cfg.x = 2 + cfg["y"] = "bar" + assert cfg["x"] == 2 + assert cfg.y == "bar" + with pytest.raises(TypeError, match="can't be deleted"): + del cfg.x + with pytest.raises(TypeError, match="can't be deleted"): + del cfg["y"] + assert cfg.x == 2 + assert cfg == cfg + assert cfg == ExampleConfig(x=2, y="bar") + assert cfg != ExampleConfig(x=3, y="baz") + assert cfg != Config(x=2, y="bar") + with pytest.raises(TypeError, match="y must be a str"): + cfg["y"] = 5 + with pytest.raises(ValueError, match="x must be positive"): + cfg.x = -5 + assert cfg.get("x", 10) == 2 + with pytest.raises(AttributeError): + cfg.z = 5 + with pytest.raises(KeyError): + cfg["z"] = 5 + with pytest.raises(AttributeError): + cfg.z + with pytest.raises(KeyError): + cfg["z"] + cfg2 = pickle.loads(pickle.dumps(cfg)) + assert cfg == cfg2 + assert cfg.__doc__ == "Example configuration." + assert cfg2.__doc__ == "Example configuration." + + +def test_config_defaults(): + class DefaultConfig(Config): + x: int = 0 + y: int + + cfg = DefaultConfig(y=1) + assert cfg.x == 0 + cfg = DefaultConfig(x=2, y=1) + assert cfg.x == 2 + + +def test_nxconfig(): + assert isinstance(nx.config.backend_priority, BackendPriorities) + assert isinstance(nx.config.backend_priority.algos, list) + assert isinstance(nx.config.backends, Config) + with pytest.raises(TypeError, match="must be a list of backend names"): + nx.config.backend_priority.algos = "nx_loopback" + with pytest.raises(ValueError, match="Unknown backend when setting"): + nx.config.backend_priority.algos = ["this_almost_certainly_is_not_a_backend"] + with pytest.raises(TypeError, match="must be a Config of backend configs"): + nx.config.backends = {} + with pytest.raises(TypeError, match="must be a Config of backend configs"): + nx.config.backends = Config(plausible_backend_name={}) + with pytest.raises(ValueError, match="Unknown backend when setting"): + nx.config.backends = Config(this_almost_certainly_is_not_a_backend=Config()) + with pytest.raises(TypeError, match="must be True or False"): + nx.config.cache_converted_graphs = "bad value" + with pytest.raises(TypeError, match="must be a set of "): + nx.config.warnings_to_ignore = 7 + with pytest.raises(ValueError, match="Unknown warning "): + nx.config.warnings_to_ignore = {"bad value"} + + +def test_not_strict(): + class FlexibleConfig(Config, strict=False): + x: int + + cfg = FlexibleConfig(x=1) + assert "_strict" not in cfg + assert len(cfg) == 1 + assert list(cfg) == ["x"] + assert list(cfg.keys()) == ["x"] + assert list(cfg.values()) == [1] + assert list(cfg.items()) == [("x", 1)] + assert cfg.x == 1 + assert cfg["x"] == 1 + assert "x" in cfg + assert hasattr(cfg, "x") + assert "FlexibleConfig(x=1)" in repr(cfg) + assert cfg == FlexibleConfig(x=1) + del cfg.x + assert "FlexibleConfig()" in repr(cfg) + assert len(cfg) == 0 + assert not hasattr(cfg, "x") + assert "x" not in cfg + assert not hasattr(cfg, "y") + assert "y" not in cfg + cfg.y = 2 + assert len(cfg) == 1 + assert list(cfg) == ["y"] + assert list(cfg.keys()) == ["y"] + assert list(cfg.values()) == [2] + assert list(cfg.items()) == [("y", 2)] + assert cfg.y == 2 + assert cfg["y"] == 2 + assert hasattr(cfg, "y") + assert "y" in cfg + del cfg["y"] + assert len(cfg) == 0 + assert list(cfg) == [] + with pytest.raises(AttributeError, match="y"): + del cfg.y + with pytest.raises(KeyError, match="y"): + del cfg["y"] + with pytest.raises(TypeError, match="missing 1 required keyword-only"): + FlexibleConfig() + # Be strict when first creating the config object + with pytest.raises(TypeError, match="unexpected keyword argument 'y'"): + FlexibleConfig(x=1, y=2) + + class FlexibleConfigWithDefault(Config, strict=False): + x: int = 0 + + assert FlexibleConfigWithDefault().x == 0 + assert FlexibleConfigWithDefault(x=1)["x"] == 1 + + +def test_context(): + cfg = Config(x=1) + with cfg(x=2) as c: + assert c.x == 2 + c.x = 3 + assert cfg.x == 3 + assert cfg.x == 1 + + with cfg(x=2) as c: + assert c == cfg + assert cfg.x == 2 + with cfg(x=3) as c2: + assert c2 == cfg + assert cfg.x == 3 + with pytest.raises(RuntimeError, match="context manager without"): + with cfg as c3: # Forgot to call `cfg(...)` + pass + assert cfg.x == 3 + assert cfg.x == 2 + assert cfg.x == 1 + + c = cfg(x=4) # Not yet as context (not recommended, but possible) + assert c == cfg + assert cfg.x == 4 + # Cheat by looking at internal data; context stack should only grow with __enter__ + assert cfg._prev is not None + assert cfg._context_stack == [] + with c: + assert c == cfg + assert cfg.x == 4 + assert cfg.x == 1 + # Cheat again; there was no preceding `cfg(...)` call this time + assert cfg._prev is None + with pytest.raises(RuntimeError, match="context manager without"): + with cfg: + pass + assert cfg.x == 1 diff --git a/janus/lib/python3.10/site-packages/networkx/utils/tests/test_unionfind.py b/janus/lib/python3.10/site-packages/networkx/utils/tests/test_unionfind.py new file mode 100644 index 0000000000000000000000000000000000000000..2d30580fc942e3715f2a6a25125bad9f9e1e74b6 --- /dev/null +++ b/janus/lib/python3.10/site-packages/networkx/utils/tests/test_unionfind.py @@ -0,0 +1,55 @@ +import networkx as nx + + +def test_unionfind(): + # Fixed by: 2cddd5958689bdecdcd89b91ac9aaf6ce0e4f6b8 + # Previously (in 2.x), the UnionFind class could handle mixed types. + # But in Python 3.x, this causes a TypeError such as: + # TypeError: unorderable types: str() > int() + # + # Now we just make sure that no exception is raised. + x = nx.utils.UnionFind() + x.union(0, "a") + + +def test_subtree_union(): + # See https://github.com/networkx/networkx/pull/3224 + # (35db1b551ee65780794a357794f521d8768d5049). + # Test if subtree unions hare handled correctly by to_sets(). + uf = nx.utils.UnionFind() + uf.union(1, 2) + uf.union(3, 4) + uf.union(4, 5) + uf.union(1, 5) + assert list(uf.to_sets()) == [{1, 2, 3, 4, 5}] + + +def test_unionfind_weights(): + # Tests if weights are computed correctly with unions of many elements + uf = nx.utils.UnionFind() + uf.union(1, 4, 7) + uf.union(2, 5, 8) + uf.union(3, 6, 9) + uf.union(1, 2, 3, 4, 5, 6, 7, 8, 9) + assert uf.weights[uf[1]] == 9 + + +def test_unbalanced_merge_weights(): + # Tests if the largest set's root is used as the new root when merging + uf = nx.utils.UnionFind() + uf.union(1, 2, 3) + uf.union(4, 5, 6, 7, 8, 9) + assert uf.weights[uf[1]] == 3 + assert uf.weights[uf[4]] == 6 + largest_root = uf[4] + uf.union(1, 4) + assert uf[1] == largest_root + assert uf.weights[largest_root] == 9 + + +def test_empty_union(): + # Tests if a null-union does nothing. + uf = nx.utils.UnionFind((0, 1)) + uf.union() + assert uf[0] == 0 + assert uf[1] == 1