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Runs multiple Fisher scoring steps.
def fit( model_matrix, response, model, model_coefficients_start=None, predicted_linear_response_start=None, l2_regularizer=None, dispersion=None, offset=None, convergence_criteria_fn=None, learning_rate=None, fast_unsafe_numerics=True, maximum_iterations=None, name=N...
Runs one step of Fisher scoring.
def fit_one_step( model_matrix, response, model, model_coefficients_start=None, predicted_linear_response_start=None, l2_regularizer=None, dispersion=None, offset=None, learning_rate=None, fast_unsafe_numerics=True, name=None): """Runs one step of Fisher scoring. Args: ...
Returns Python callable which indicates fitting procedure has converged.
def convergence_criteria_small_relative_norm_weights_change( tolerance=1e-5, norm_order=2): """Returns Python `callable` which indicates fitting procedure has converged. Writing old, new `model_coefficients` as `w0`, `w1`, this function defines convergence as, ```python relative_euclidean_norm = (tf...
Helper to fit which sanitizes input args.
def prepare_args(model_matrix, response, model_coefficients, predicted_linear_response, offset, name=None): """Helper to `fit` which sanitizes input args. Args: model_matrix: (Batch of) `float`-like, matrix-shaped `Tensor` whe...
Computes model_matrix
def calculate_linear_predictor(model_matrix, model_coefficients, offset=None, name=None): """Computes `model_matrix @ model_coefficients + offset`.""" with tf.compat.v1.name_scope(name, 'calculate_linear_predictor', [model_matrix, model_coefficients, off...
Returns number of cols in a given Tensor.
def num_cols(x): """Returns number of cols in a given `Tensor`.""" if tf.compat.dimension_value(x.shape[-1]) is not None: return tf.compat.dimension_value(x.shape[-1]) return tf.shape(input=x)[-1]
Wraps original_fn preferring to call static_fn when inputs are static.
def _prefer_static(original_fn, static_fn): """Wraps original_fn, preferring to call static_fn when inputs are static.""" original_spec = tf_inspect.getfullargspec(original_fn) static_spec = tf_inspect.getfullargspec(static_fn) if original_spec != static_spec: raise ValueError( 'Arg specs do not mat...
Wraps new_fn with the doc of original_fn.
def _copy_docstring(original_fn, new_fn): """Wraps new_fn with the doc of original_fn.""" original_spec = tf_inspect.getfullargspec(original_fn) new_spec = tf_inspect.getfullargspec(new_fn) if original_spec != new_spec: raise ValueError( 'Arg specs do not match: original={}, new={}, fn={}'.format( ...
Helper function for statically evaluating predicates in cond.
def _get_static_predicate(pred): """Helper function for statically evaluating predicates in `cond`.""" if pred in {0, 1}: # Accept 1/0 as valid boolean values pred_value = bool(pred) elif isinstance(pred, bool): pred_value = pred elif isinstance(pred, tf.Tensor): pred_value = tf.get_static_value(pr...
Computes rank given a Tensor s shape.
def rank_from_shape(shape_tensor_fn, tensorshape=None): """Computes `rank` given a `Tensor`'s `shape`.""" if tensorshape is None: shape_tensor = (shape_tensor_fn() if callable(shape_tensor_fn) else shape_tensor_fn) if (hasattr(shape_tensor, 'shape') and hasattr(shape_tensor.shap...
Return either true_fn () if predicate pred is true else false_fn ().
def cond(pred, true_fn=None, false_fn=None, name=None): """Return either `true_fn()` if predicate `pred` is true else `false_fn()`. If `pred` is a bool or has a constant value, we return either `true_fn()` or `false_fn()`, otherwise we use `tf.cond` to dynamically route to both. Arguments: pred: A scalar ...
Like tf. case except attempts to statically evaluate predicates.
def case(pred_fn_pairs, default=None, exclusive=False, name='smart_case'): """Like tf.case, except attempts to statically evaluate predicates. If any predicate in `pred_fn_pairs` is a bool or has a constant value, the associated callable will be called or omitted depending on its value. Otherwise this function...
Computes D ( param = mean ( r )). log_prob ( response ) for linear response r.
def log_prob(self, response, predicted_linear_response, name=None): """Computes `D(param=mean(r)).log_prob(response)` for linear response, `r`. Args: response: `float`-like `Tensor` representing observed ("actual") responses. predicted_linear_response: `float`-like `Tensor` corresponding to...
Helper function to standardize op scope.
def _name_scope(self, name=None, default_name=None, values=None): """Helper function to standardize op scope.""" with tf.compat.v1.name_scope(self.name): with tf.compat.v1.name_scope( name, default_name, values=values or []) as scope: yield scope
Computes the standard deviation of a mixture distribution.
def mixture_stddev(mixture_weight_vector, mean_vector, stddev_vector): """Computes the standard deviation of a mixture distribution. This function works regardless of the component distribution, so long as each component's mean and standard deviation can be provided. Args: mixture_weight_vector: A 2D tens...
Creates a LinearOperator representing a lower triangular matrix.
def make_tril_scale(loc=None, scale_tril=None, scale_diag=None, scale_identity_multiplier=None, shape_hint=None, validate_args=False, assert_positive=False, name=None): """Create...
Creates a LinearOperator representing a diagonal matrix.
def make_diag_scale(loc=None, scale_diag=None, scale_identity_multiplier=None, shape_hint=None, validate_args=False, assert_positive=False, name=None, dtype=None): """Creates a L...
Infer distribution batch and event shapes from a location and scale.
def shapes_from_loc_and_scale(loc, scale, name="shapes_from_loc_and_scale"): """Infer distribution batch and event shapes from a location and scale. Location and scale family distributions determine their batch/event shape by broadcasting the `loc` and `scale` args. This helper does that broadcast, statically...
Get broadcast shape as a Python list of integers ( preferred ) or Tensor.
def get_broadcast_shape(*tensors): """Get broadcast shape as a Python list of integers (preferred) or `Tensor`. Args: *tensors: One or more `Tensor` objects (already converted!). Returns: broadcast shape: Python list (if shapes determined statically), otherwise an `int32` `Tensor`. """ # Try...
Returns True if scale is a LinearOperator that is known to be diag.
def is_diagonal_scale(scale): """Returns `True` if `scale` is a `LinearOperator` that is known to be diag. Args: scale: `LinearOperator` instance. Returns: Python `bool`. Raises: TypeError: If `scale` is not a `LinearOperator`. """ if not isinstance(scale, tf.linalg.LinearOperator): rai...
Helper which checks validity of a scalar distribution init arg.
def maybe_check_scalar_distribution(distribution, expected_base_dtype, validate_args): """Helper which checks validity of a scalar `distribution` init arg. Valid here means: * `distribution` has scalar batch and event shapes. * `distribution` is `FULLY_REPARAMETERIZED` * ...
Pad dimensions of event tensors for mixture distributions.
def pad_mixture_dimensions(x, mixture_distribution, categorical_distribution, event_ndims): """Pad dimensions of event tensors for mixture distributions. See `Mixture._sample_n` and `MixtureSameFamily._sample_n` for usage examples. Args: x: event tensor to pad. mixture_distrib...
Convenience function that chooses one of two values based on the predicate.
def pick_scalar_condition(pred, true_value, false_value, name=None): """Convenience function that chooses one of two values based on the predicate. This utility is equivalent to a version of `tf.where` that accepts only a scalar predicate and computes its result statically when possible. It may also be used in...
Make ( possibly negatively indexed ) axis argument non - negative.
def make_non_negative_axis(axis, rank): """Make (possibly negatively indexed) `axis` argument non-negative.""" axis = tf.convert_to_tensor(value=axis, name="axis") rank = tf.convert_to_tensor(value=rank, name="rank") axis_ = tf.get_static_value(axis) rank_ = tf.get_static_value(rank) # Static case. if ax...
Move a single tensor dimension within its shape.
def move_dimension(x, source_idx, dest_idx): """Move a single tensor dimension within its shape. This is a special case of `tf.transpose()`, which applies arbitrary permutations to tensor dimensions. Args: x: Tensor of rank `ndims`. source_idx: Integer index into `x.shape` (negative indexing is suppor...
Assert that x has integer components ( or floats equal to integers ).
def assert_integer_form(x, data=None, summarize=None, message=None, int_dtype=None, name="assert_integer_form"): """Assert that x has integer components (or floats equal to integers). Args: x...
Assert x is a non - negative tensor and optionally of integers.
def embed_check_nonnegative_integer_form( x, name="embed_check_nonnegative_integer_form"): """Assert x is a non-negative tensor, and optionally of integers.""" with tf.name_scope(name): x = tf.convert_to_tensor(value=x, name="x") assertions = [ assert_util.assert_non_negative( x, mes...
Returns whether a and b have the same dynamic shape.
def same_dynamic_shape(a, b): """Returns whether a and b have the same dynamic shape. Args: a: `Tensor` b: `Tensor` Returns: `bool` `Tensor` representing if both tensors have the same shape. """ a = tf.convert_to_tensor(value=a, name="a") b = tf.convert_to_tensor(value=b, name="b") # Here w...
Helper which tries to return a static value.
def maybe_get_static_value(x, dtype=None): """Helper which tries to return a static value. Given `x`, extract it's value statically, optionally casting to a specific dtype. If this is not possible, None is returned. Args: x: `Tensor` for which to extract a value statically. dtype: Optional dtype to ca...
Converts logit to probabilities ( or vice - versa ) and returns both.
def get_logits_and_probs(logits=None, probs=None, multidimensional=False, validate_args=False, name="get_logits_and_probs", dtype=None): """Converts logit to probabilities (or vice-versa), and ...
Helper returning True if dtype is known to be unsigned.
def _is_known_unsigned_by_dtype(dt): """Helper returning True if dtype is known to be unsigned.""" return { tf.bool: True, tf.uint8: True, tf.uint16: True, }.get(dt.base_dtype, False)
Helper returning True if dtype is known to be signed.
def _is_known_signed_by_dtype(dt): """Helper returning True if dtype is known to be signed.""" return { tf.float16: True, tf.float32: True, tf.float64: True, tf.int8: True, tf.int16: True, tf.int32: True, tf.int64: True, }.get(dt.base_dtype, False)
Helper returning the largest integer exactly representable by dtype.
def _largest_integer_by_dtype(dt): """Helper returning the largest integer exactly representable by dtype.""" if not _is_known_dtype(dt): raise TypeError("Unrecognized dtype: {}".format(dt.name)) if dt.is_floating: return int(2**(np.finfo(dt.as_numpy_dtype).nmant + 1)) if dt.is_integer: return np.ii...
Helper returning the smallest integer exactly representable by dtype.
def _smallest_integer_by_dtype(dt): """Helper returning the smallest integer exactly representable by dtype.""" if not _is_known_dtype(dt): raise TypeError("Unrecognized dtype: {}".format(dt.name)) if _is_known_unsigned_by_dtype(dt): return 0 return -1 * _largest_integer_by_dtype(dt)
Helper returning True if dtype. is_integer or is bool.
def _is_integer_like_by_dtype(dt): """Helper returning True if dtype.is_integer or is `bool`.""" if not _is_known_dtype(dt): raise TypeError("Unrecognized dtype: {}".format(dt.name)) return dt.is_integer or dt.base_dtype == tf.bool
Embeds checks that categorical distributions don t have too many classes.
def embed_check_categorical_event_shape( categorical_param, name="embed_check_categorical_event_shape"): """Embeds checks that categorical distributions don't have too many classes. A categorical-type distribution is one which, e.g., returns the class label rather than a one-hot encoding. E.g., `Categorical...
Ensures integers remain unaffected despite casting to/ from int/ float types.
def embed_check_integer_casting_closed(x, target_dtype, assert_nonnegative=True, assert_positive=False, name="embed_check_casting_closed"): """Ensures integers re...
Multinomial coefficient.
def log_combinations(n, counts, name="log_combinations"): """Multinomial coefficient. Given `n` and `counts`, where `counts` has last dimension `k`, we compute the multinomial coefficient as: ```n! / sum_i n_i!``` where `i` runs over all `k` classes. Args: n: Floating-point `Tensor` broadcastable wi...
Transform diagonal of [ batch - ] matrix leave rest of matrix unchanged.
def matrix_diag_transform(matrix, transform=None, name=None): """Transform diagonal of [batch-]matrix, leave rest of matrix unchanged. Create a trainable covariance defined by a Cholesky factor: ```python # Transform network layer into 2 x 2 array. matrix_values = tf.contrib.layers.fully_connected(activatio...
Circularly moves dims left or right.
def rotate_transpose(x, shift, name="rotate_transpose"): """Circularly moves dims left or right. Effectively identical to: ```python numpy.transpose(x, numpy.roll(numpy.arange(len(x.shape)), shift)) ``` When `validate_args=False` additional graph-runtime checks are performed. These checks entail moving...
Picks possibly different length row Tensor s based on condition.
def pick_vector(cond, true_vector, false_vector, name="pick_vector"): """Picks possibly different length row `Tensor`s based on condition. Value `Tensor`s should have exactly one dimension. If `cond` is a python Boolean or `tf.constant` then either `true_vector` or `false_vector` is immediately returned. I.e....
Convenience function which statically broadcasts shape when possible.
def prefer_static_broadcast_shape(shape1, shape2, name="prefer_static_broadcast_shape"): """Convenience function which statically broadcasts shape when possible. Args: shape1: `1-D` integer `Tensor`. Already converted to tensor! shape2: ...
Generate a new seed from the given seed and salt.
def gen_new_seed(seed, salt): """Generate a new seed, from the given seed and salt.""" if seed is None: return None string = (str(seed) + salt).encode("utf-8") return int(hashlib.md5(string).hexdigest()[:8], 16) & 0x7FFFFFFF
r Creates a ( batch of ) triangular matrix from a vector of inputs.
def fill_triangular(x, upper=False, name=None): r"""Creates a (batch of) triangular matrix from a vector of inputs. Created matrix can be lower- or upper-triangular. (It is more efficient to create the matrix as upper or lower, rather than transpose.) Triangular matrix elements are filled in a clockwise spira...
Creates a vector from a ( batch of ) triangular matrix.
def fill_triangular_inverse(x, upper=False, name=None): """Creates a vector from a (batch of) triangular matrix. The vector is created from the lower-triangular or upper-triangular portion depending on the value of the parameter `upper`. If `x.shape` is `[b1, b2, ..., bB, n, n]` then the output shape is `[b...
Creates a matrix with values set above below and on the diagonal.
def tridiag(below=None, diag=None, above=None, name=None): """Creates a matrix with values set above, below, and on the diagonal. Example: ```python tridiag(below=[1., 2., 3.], diag=[4., 5., 6., 7.], above=[8., 9., 10.]) # ==> array([[ 4., 8., 0., 0.], # [ 1., 5., ...
Computes log ( abs ( sum ( weight * exp ( elements across tensor dimensions )))).
def reduce_weighted_logsumexp(logx, w=None, axis=None, keep_dims=False, return_sign=False, name=None): """Computes `log(abs(sum(weight * exp(elements across tensor dime...
Computes the inverse softplus i. e. x = softplus_inverse ( softplus ( x )).
def softplus_inverse(x, name=None): """Computes the inverse softplus, i.e., x = softplus_inverse(softplus(x)). Mathematically this op is equivalent to: ```none softplus_inverse = log(exp(x) - 1.) ``` Args: x: `Tensor`. Non-negative (not enforced), floating-point. name: A name for the operation (o...
Returns the size of a specific dimension.
def dimension_size(x, axis): """Returns the size of a specific dimension.""" # Since tf.gather isn't "constant-in, constant-out", we must first check the # static shape or fallback to dynamic shape. s = tf.compat.dimension_value( tensorshape_util.with_rank_at_least(x.shape, np.abs(axis))[axis]) if s is ...
Validates quadrature grid probs or computes them as necessary.
def process_quadrature_grid_and_probs(quadrature_grid_and_probs, dtype, validate_args, name=None): """Validates quadrature grid, probs or computes them as necessary. Args: quadrature_grid_and_probs...
Pads value to the front and/ or back of a Tensor dim count times.
def pad(x, axis, front=False, back=False, value=0, count=1, name=None): """Pads `value` to the front and/or back of a `Tensor` dim, `count` times. Args: x: `Tensor` input. axis: Scalar `int`-like `Tensor` representing the single dimension to pad. (Negative indexing is supported.) front: Python `b...
Returns parent frame arguments.
def parent_frame_arguments(): """Returns parent frame arguments. When called inside a function, returns a dictionary with the caller's function arguments. These are positional arguments and keyword arguments (**kwargs), while variable arguments (*varargs) are excluded. When called at global scope, this will...
Transform a 0 - D or 1 - D Tensor to be 1 - D.
def expand_to_vector(x, tensor_name=None, op_name=None, validate_args=False): """Transform a 0-D or 1-D `Tensor` to be 1-D. For user convenience, many parts of the TensorFlow Probability API accept inputs of rank 0 or 1 -- i.e., allowing an `event_shape` of `[5]` to be passed to the API as either `5` or `[5]`....
Produces the content of output_tensor only after dependencies.
def with_dependencies(dependencies, output_tensor, name=None): """Produces the content of `output_tensor` only after `dependencies`. In some cases, a user may want the output of an operation to be consumed externally only after some other dependencies have run first. This function returns `output_tensor`, but ...
Checks that rightmost_transposed_ndims is valid.
def _maybe_validate_rightmost_transposed_ndims( rightmost_transposed_ndims, validate_args, name=None): """Checks that `rightmost_transposed_ndims` is valid.""" with tf.name_scope(name or 'maybe_validate_rightmost_transposed_ndims'): assertions = [] if not dtype_util.is_integer(rightmost_transposed_ndims...
Checks that perm is valid.
def _maybe_validate_perm(perm, validate_args, name=None): """Checks that `perm` is valid.""" with tf.name_scope(name or 'maybe_validate_perm'): assertions = [] if not dtype_util.is_integer(perm.dtype): raise TypeError('`perm` must be integer type') msg = '`perm` must be a vector.' if tensorsh...
Helper for _forward and _inverse_event_shape.
def _event_shape(self, shape, static_perm_to_shape): """Helper for _forward and _inverse_event_shape.""" rightmost_ = tf.get_static_value(self.rightmost_transposed_ndims) if tensorshape_util.rank(shape) is None or rightmost_ is None: return tf.TensorShape(None) if tensorshape_util.rank(shape) < ri...
Returns the concatenation of the dimension in x and other.
def concatenate(x, other): """Returns the concatenation of the dimension in `x` and `other`. *Note:* If either `x` or `other` is completely unknown, concatenation will discard information about the other shape. In future, we might support concatenation that preserves this information for use with slicing. F...
A version of constant_value () that returns a TensorShape.
def constant_value_as_shape(tensor): # pylint: disable=invalid-name """A version of `constant_value()` that returns a `TensorShape`. This version should be used when a constant tensor value is interpreted as a (possibly partial) shape, e.g. in the shape function for `tf.reshape()`. By explicitly requesting a ...
Returns a list of dimension sizes or None if rank is unknown.
def dims(x): """Returns a list of dimension sizes, or `None` if `rank` is unknown. For more details, see `help(tf.TensorShape.dims)`. Args: x: object representing a shape; convertible to `tf.TensorShape`. Returns: shape_as_list: list of sizes or `None` values representing each dimensions size i...
Returns a shape combining the information in x and other.
def merge_with(x, other): """Returns a shape combining the information in `x` and `other`. The dimensions in `x` and `other` are merged elementwise, according to the rules defined for `tf.Dimension.merge_with()`. For more details, see `help(tf.TensorShape.merge_with)`. Args: x: object representing a sh...
Returns a shape based on x with at least the given rank.
def with_rank_at_least(x, rank): # pylint: disable=redefined-outer-name """Returns a shape based on `x` with at least the given `rank`. For more details, see `help(tf.TensorShape.with_rank_at_least)`. Args: x: object representing a shape; convertible to `tf.TensorShape`. rank: An `int` representing the...
Check that source and target shape match statically if possible.
def _check_equal_shape(name, static_shape, dynamic_shape, static_target_shape, dynamic_target_shape=None): """Check that source and target shape match, statically if possible.""" static_target_shape = tf.TensorShape(static_...
Augment a sample shape to broadcast batch dimensions.
def _augment_sample_shape(partial_batch_dist, full_sample_and_batch_shape, validate_args=False): """Augment a sample shape to broadcast batch dimensions. Computes an augmented sample shape, so that any batch dimensions not part of the distribution `partial_batc...
Build a callable that perform one step for backward smoothing.
def build_backward_pass_step(get_transition_matrix_for_timestep): """Build a callable that perform one step for backward smoothing. Args: get_transition_matrix_for_timestep: callable taking a timestep as an integer `Tensor` argument, and returning a `LinearOperator` of shape `[latent_size, latent_s...
Backward update for a Kalman smoother.
def backward_smoothing_update(filtered_mean, filtered_cov, predicted_mean, predicted_cov, next_posterior_mean, next_posterior_cov, transitio...
Build a callable that performs one step of Kalman filtering.
def build_kalman_filter_step(get_transition_matrix_for_timestep, get_transition_noise_for_timestep, get_observation_matrix_for_timestep, get_observation_noise_for_timestep): """Build a callable that performs one step of Kalman filt...
Conjugate update for a linear Gaussian model.
def linear_gaussian_update( prior_mean, prior_cov, observation_matrix, observation_noise, x_observed): """Conjugate update for a linear Gaussian model. Given a normal prior on a latent variable `z`, `p(z) = N(prior_mean, prior_cov) = N(u, P)`, for which we observe a linear Gaussian transformation `x`, ...
Propagate a filtered distribution through a transition model.
def kalman_transition(filtered_mean, filtered_cov, transition_matrix, transition_noise): """Propagate a filtered distribution through a transition model.""" predicted_mean = _propagate_mean(filtered_mean, transition_matrix, ...
Build a callable that performs one step of Kalman mean recursion.
def build_kalman_mean_step(get_transition_matrix_for_timestep, get_transition_noise_for_timestep, get_observation_matrix_for_timestep, get_observation_noise_for_timestep): """Build a callable that performs one step of Kalman mean recursi...
Build a callable for one step of Kalman covariance recursion.
def build_kalman_cov_step(get_transition_matrix_for_timestep, get_transition_noise_for_timestep, get_observation_matrix_for_timestep, get_observation_noise_for_timestep): """Build a callable for one step of Kalman covariance recursion. A...
Build a callable for one step of Kalman sampling recursion.
def build_kalman_sample_step(get_transition_matrix_for_timestep, get_transition_noise_for_timestep, get_observation_matrix_for_timestep, get_observation_noise_for_timestep, full_sample_and_batch_shape, ...
Build a callable to push latent means/ covs to observed means/ covs.
def build_pushforward_latents_step(get_observation_matrix_for_timestep, get_observation_noise_for_timestep): """Build a callable to push latent means/covs to observed means/covs. Args: get_observation_matrix_for_timestep: callable taking a timestep as an integer `Tensor...
Propagate a mean through linear Gaussian transformation.
def _propagate_mean(mean, linop, dist): """Propagate a mean through linear Gaussian transformation.""" return linop.matmul(mean) + dist.mean()[..., tf.newaxis]
Propagate covariance through linear Gaussian transformation.
def _propagate_cov(cov, linop, dist): """Propagate covariance through linear Gaussian transformation.""" # For linop A and input cov P, returns `A P A' + dist.cov()` return linop.matmul(linop.matmul(cov), adjoint_arg=True) + dist.covariance()
Run the backward pass in Kalman smoother.
def backward_smoothing_pass(self, filtered_means, filtered_covs, predicted_means, predicted_covs): """Run the backward pass in Kalman smoother. The backward smoothing is using Rauch, Tung and...
Draw a joint sample from the prior over latents and observations.
def _joint_sample_n(self, n, seed=None): """Draw a joint sample from the prior over latents and observations.""" with tf.name_scope("sample_n_joint"): stream = seed_stream.SeedStream( seed, salt="LinearGaussianStateSpaceModel_sample_n_joint") sample_and_batch_shape = distribution_util.pr...
Run a Kalman filter over a provided sequence of outputs.
def forward_filter(self, x, mask=None): """Run a Kalman filter over a provided sequence of outputs. Note that the returned values `filtered_means`, `predicted_means`, and `observation_means` depend on the observed time series `x`, while the corresponding covariances are independent of the observed seri...
Run a Kalman smoother to return posterior mean and cov.
def posterior_marginals(self, x, mask=None): """Run a Kalman smoother to return posterior mean and cov. Note that the returned values `smoothed_means` depend on the observed time series `x`, while the `smoothed_covs` are independent of the observed series; i.e., they depend only on the model itself. ...
Compute prior means for all variables via dynamic programming.
def _joint_mean(self): """Compute prior means for all variables via dynamic programming. Returns: latent_means: Prior means of latent states `z_t`, as a `Tensor` of shape `batch_shape + [num_timesteps, latent_size]` observation_means: Prior covariance matrices of observations `x_t`,...
Compute prior covariances for all variables via dynamic programming.
def _joint_covariances(self): """Compute prior covariances for all variables via dynamic programming. Returns: latent_covs: Prior covariance matrices of latent states `z_t`, as a `Tensor` of shape `batch_shape + [num_timesteps, latent_size, latent_size]` observation_covs: Prior cova...
Push latent means and covariances forward through the observation model.
def latents_to_observations(self, latent_means, latent_covs): """Push latent means and covariances forward through the observation model. Args: latent_means: float `Tensor` of shape `[..., num_timesteps, latent_size]` latent_covs: float `Tensor` of shape `[..., num_timesteps, latent_size, l...
Computes I_v ( z ) * exp ( - abs ( z )) using a recurrence relation where z > 0.
def _bessel_ive(v, z, cache=None): """Computes I_v(z)*exp(-abs(z)) using a recurrence relation, where z > 0.""" # TODO(b/67497980): Switch to a more numerically faithful implementation. z = tf.convert_to_tensor(value=z) wrap = lambda result: tf.debugging.check_numerics(result, 'besseli{}'.format(v ...
Computes the log - normalizer of the distribution.
def _log_normalization(self): """Computes the log-normalizer of the distribution.""" event_dim = tf.compat.dimension_value(self.event_shape[0]) if event_dim is None: raise ValueError('vMF _log_normalizer currently only supports ' 'statically known event shape') safe_conc = t...
Check counts for proper shape values then return tensor version.
def _maybe_assert_valid_sample(self, samples): """Check counts for proper shape, values, then return tensor version.""" if not self.validate_args: return samples with tf.control_dependencies([ assert_util.assert_near( 1., tf.linalg.norm(tensor=samples, axis=-1), ...
The mode of the von Mises - Fisher distribution is the mean direction.
def _mode(self): """The mode of the von Mises-Fisher distribution is the mean direction.""" return (self.mean_direction + tf.zeros_like(self.concentration)[..., tf.newaxis])
Applies a Householder rotation to samples.
def _rotate(self, samples): """Applies a Householder rotation to `samples`.""" event_dim = ( tf.compat.dimension_value(self.event_shape[0]) or self._event_shape_tensor()[0]) basis = tf.concat([[1.], tf.zeros([event_dim - 1], dtype=self.dtype)], axis=0), u = tf.nn.l2...
Specialized inversion sampler for 3D.
def _sample_3d(self, n, seed=None): """Specialized inversion sampler for 3D.""" seed = seed_stream.SeedStream(seed, salt='von_mises_fisher_3d') u_shape = tf.concat([[n], self._batch_shape_tensor()], axis=0) z = tf.random.uniform(u_shape, seed=seed(), dtype=self.dtype) # TODO(bjp): Higher-order odd d...
Create a deep copy of fn.
def _copy_fn(fn): """Create a deep copy of fn. Args: fn: a callable Returns: A `FunctionType`: a deep copy of fn. Raises: TypeError: if `fn` is not a callable. """ if not callable(fn): raise TypeError("fn is not callable: {}".format(fn)) # The blessed way to copy a function. copy.deepco...
Update old_str by inserting append_str just before the Args: section.
def _update_docstring(old_str, append_str): """Update old_str by inserting append_str just before the "Args:" section.""" old_str = old_str or "" old_str_lines = old_str.split("\n") # Step 0: Prepend spaces to all lines of append_str. This is # necessary for correct markdown generation. append_str = "\n".j...
Converts the given value to a ( structure of ) Tensor.
def _convert_to_tensor(value, dtype=None, dtype_hint=None, name=None): """Converts the given `value` to a (structure of) `Tensor`. This function converts Python objects of various types to a (structure of) `Tensor` objects. It accepts `Tensor` objects, numpy arrays, Python lists, and Python scalars. For exampl...
Removes dict keys which have have self as value.
def _remove_dict_keys_with_value(dict_, val): """Removes `dict` keys which have have `self` as value.""" return {k: v for k, v in dict_.items() if v is not val}
Recursively replace dict s with _PrettyDict.
def _recursively_replace_dict_for_pretty_dict(x): """Recursively replace `dict`s with `_PrettyDict`.""" # We use "PrettyDict" because collections.OrderedDict repr/str has the word # "OrderedDict" in it. We only want to print "OrderedDict" if in fact the # input really is an OrderedDict. if isinstance(x, dict)...
Computes the Monte - Carlo approximation of E_p [ f ( X ) ].
def expectation(f, samples, log_prob=None, use_reparametrization=True, axis=0, keep_dims=False, name=None): """Computes the Monte-Carlo approximation of `E_p[f(X)]`. This function computes the Monte-Carlo approximation of an expectation, i.e., ```none E_p[f(X)] approx= m**-1 sum_i^m f(x_j), x...
Check args and return samples.
def _get_samples(dist, z, n, seed): """Check args and return samples.""" with tf.compat.v1.name_scope('get_samples', values=[z, n]): if (n is None) == (z is None): raise ValueError( 'Must specify exactly one of arguments "n" and "z". Found: ' 'n = %s, z = %s' % (n, z)) if n is not...
Helper which returns True if input is collections. namedtuple - like.
def is_namedtuple_like(x): """Helper which returns `True` if input is `collections.namedtuple`-like.""" try: for fn in x._fields: _ = getattr(x, fn) return True except AttributeError: return False
Helper which makes a str name ; useful for tf. compat. v1. name_scope.
def make_name(super_name, default_super_name, sub_name): """Helper which makes a `str` name; useful for tf.compat.v1.name_scope.""" name = super_name if super_name is not None else default_super_name if sub_name is not None: name += '_' + sub_name return name
Helper to choose which expand_dims is_accepted and applies tf. where.
def _choose_base_case(is_accepted, accepted, rejected, name=None): """Helper to `choose` which expand_dims `is_accepted` and applies tf.where.""" def _expand_is_accepted_like(x): """Helper to expand `is_accepted` like the shape of some input arg....
Helper which expand_dims is_accepted then applies tf. where.
def choose(is_accepted, accepted, rejected, name=None): """Helper which expand_dims `is_accepted` then applies tf.where.""" if not is_namedtuple_like(accepted): return _choose_base_case(is_accepted, accepted, rejected, name=name) if not isinstance(accepted, type(rejected)): raise TypeError('Type of `accep...
Elementwise adds list members replacing non - finite results with alt_value.
def safe_sum(x, alt_value=-np.inf, name=None): """Elementwise adds list members, replacing non-finite results with alt_value. Typically the `alt_value` is chosen so the `MetropolisHastings` `TransitionKernel` always rejects the proposal. Args: x: Python `list` of `Tensors` to elementwise add. alt_valu...