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Helper to validate block sizes.
def _validate_block_sizes(block_sizes, bijectors, validate_args): """Helper to validate block sizes.""" block_sizes_shape = block_sizes.shape if tensorshape_util.is_fully_defined(block_sizes_shape): if (tensorshape_util.rank(block_sizes_shape) != 1 or (tensorshape_util.num_elements(block_sizes_shape) ...
Verifies that parts don t broadcast.
def maybe_check_wont_broadcast(flat_xs, validate_args): """Verifies that `parts` don't broadcast.""" flat_xs = tuple(flat_xs) # So we can receive generators. if not validate_args: # Note: we don't try static validation because it is theoretically # possible that a user wants to take advantage of broadcas...
Converts ( batch of ) scalars to ( batch of ) positive valued scalars.
def softplus_and_shift(x, shift=1e-5, name=None): """Converts (batch of) scalars to (batch of) positive valued scalars. Args: x: (Batch of) `float`-like `Tensor` representing scalars which will be transformed into positive elements. shift: `Tensor` added to `softplus` transformation of elements. ...
Converts ( batch of ) vectors to ( batch of ) lower - triangular scale matrices.
def tril_with_diag_softplus_and_shift(x, diag_shift=1e-5, name=None): """Converts (batch of) vectors to (batch of) lower-triangular scale matrices. Args: x: (Batch of) `float`-like `Tensor` representing vectors which will be transformed into lower-triangular scale matrices with positive diagonal el...
Constructs a trainable tfd. MultivariateNormalTriL distribution.
def multivariate_normal_tril(x, dims, layer_fn=tf.compat.v1.layers.dense, loc_fn=lambda x: x, scale_fn=tril_with_diag_softplus_and_shift, name=None): """Constructs a trainab...
Constructs a trainable tfd. Bernoulli distribution.
def bernoulli(x, layer_fn=tf.compat.v1.layers.dense, name=None): """Constructs a trainable `tfd.Bernoulli` distribution. This function creates a Bernoulli distribution parameterized by logits. Using default args, this function is mathematically equivalent to: ```none Y = Bernoulli(logits=matmul(W, x) + b) ...
Constructs a trainable tfd. Normal distribution.
def normal(x, layer_fn=tf.compat.v1.layers.dense, loc_fn=lambda x: x, scale_fn=1., name=None): """Constructs a trainable `tfd.Normal` distribution. This function creates a Normal distribution parameterized by loc and scale. Using default args, this function is mathema...
Constructs a trainable tfd. Poisson distribution.
def poisson(x, layer_fn=tf.compat.v1.layers.dense, log_rate_fn=lambda x: x, name=None): """Constructs a trainable `tfd.Poisson` distribution. This function creates a Poisson distribution parameterized by log rate. Using default args, this function is mathematically equivalent ...
r Finds root ( s ) of a function of single variable using the secant method.
def secant_root(objective_fn, initial_position, next_position=None, value_at_position=None, position_tolerance=1e-8, value_tolerance=1e-8, max_iterations=50, stopping_policy_fn=tf.reduce_all, ...
Applies one step of Euler - Maruyama method.
def _euler_method(random_draw_parts, state_parts, drift_parts, step_size_parts, volatility_parts, name=None): """Applies one step of Euler-Maruyama method. Generates proposal of the form: ```python tfd.Normal(loc=state_p...
Compute diffusion drift at the current location current_state.
def _get_drift(step_size_parts, volatility_parts, grads_volatility, grads_target_log_prob, name=None): """Compute diffusion drift at the current location `current_state`. The drift of the diffusion at is computed as ```none 0.5 * `step_size` * volatility_parts * `target_log_prob_...
r Helper to kernel which computes the log acceptance - correction.
def _compute_log_acceptance_correction(current_state_parts, proposed_state_parts, current_volatility_parts, proposed_volatility_parts, current_drift_parts, ...
Helper which computes volatility_fn results and grads if needed.
def _maybe_call_volatility_fn_and_grads(volatility_fn, state, volatility_fn_results=None, grads_volatility_fn=None, sample_shape=None, ...
Helper to broadcast volatility_parts to the shape of state_parts.
def _maybe_broadcast_volatility(volatility_parts, state_parts): """Helper to broadcast `volatility_parts` to the shape of `state_parts`.""" return [v + tf.zeros_like(sp, dtype=sp.dtype.base_dtype) for v, sp in zip(volatility_parts, state_parts)]
Helper which processes input args to meet list - like assumptions.
def _prepare_args(target_log_prob_fn, volatility_fn, state, step_size, target_log_prob=None, grads_target_log_prob=None, volatility=None, grads_volatility_fn=None, diffusion_dr...
Build transition matrix for an autoregressive StateSpaceModel.
def make_ar_transition_matrix(coefficients): """Build transition matrix for an autoregressive StateSpaceModel. When applied to a vector of previous values, this matrix computes the expected new value (summing the previous states according to the autoregressive coefficients) in the top dimension of the state sp...
Computes diagonal of the Jacobian matrix of ys = fn ( xs ) wrt xs.
def diag_jacobian(xs, ys=None, sample_shape=None, fn=None, parallel_iterations=10, name=None): """Computes diagonal of the Jacobian matrix of `ys=fn(xs)` wrt `xs`. If `ys` is a tensor or a list of tensors of the form `(ys_1...
Calculates the reshaped dimensions ( replacing up to one - 1 in reshape ).
def calculate_reshape(original_shape, new_shape, validate=False, name=None): """Calculates the reshaped dimensions (replacing up to one -1 in reshape).""" batch_shape_static = tensorshape_util.constant_value_as_shape(new_shape) if tensorshape_util.is_fully_defined(batch_shape_static): return np.int32(batch_sh...
Helper to __init__ which makes or raises assertions.
def validate_init_args_statically(distribution, batch_shape): """Helper to __init__ which makes or raises assertions.""" if tensorshape_util.rank(batch_shape.shape) is not None: if tensorshape_util.rank(batch_shape.shape) != 1: raise ValueError("`batch_shape` must be a vector " "(sa...
Computes graph and static sample_shape.
def _sample_shape(self, x): """Computes graph and static `sample_shape`.""" x_ndims = ( tf.rank(x) if tensorshape_util.rank(x.shape) is None else tensorshape_util.rank(x.shape)) event_ndims = ( tf.size(input=self.event_shape_tensor()) if tensorshape_util.rank(self.event_shape...
Calls fn appropriately reshaping its input x and output.
def _call_reshape_input_output(self, fn, x, extra_kwargs=None): """Calls `fn`, appropriately reshaping its input `x` and output.""" # Note: we take `extra_kwargs` as a dict rather than `**extra_kwargs` # because it is possible the user provided extra kwargs would itself # have `fn` and/or `x` as a key. ...
Calls fn and appropriately reshapes its output.
def _call_and_reshape_output( self, fn, event_shape_list=None, static_event_shape_list=None, extra_kwargs=None): """Calls `fn` and appropriately reshapes its output.""" # Note: we take `extra_kwargs` as a dict rather than `**extra_kwargs` # because it is possible the user provi...
Helper which validates sample arg e. g. input to log_prob.
def _validate_sample_arg(self, x): """Helper which validates sample arg, e.g., input to `log_prob`.""" with tf.name_scope("validate_sample_arg"): x_ndims = ( tf.rank(x) if tensorshape_util.rank(x.shape) is None else tensorshape_util.rank(x.shape)) event_ndims = ( tf.siz...
The binomial cumulative distribution function.
def _bdtr(k, n, p): """The binomial cumulative distribution function. Args: k: floating point `Tensor`. n: floating point `Tensor`. p: floating point `Tensor`. Returns: `sum_{j=0}^k p^j (1 - p)^(n - j)`. """ # Trick for getting safe backprop/gradients into n, k when # betainc(a = 0, ..) ...
Check counts for proper shape values then return tensor version.
def _maybe_assert_valid_sample(self, counts): """Check counts for proper shape, values, then return tensor version.""" if not self.validate_args: return counts counts = distribution_util.embed_check_nonnegative_integer_form(counts) return distribution_util.with_dependencies([ assert_util.a...
Executes model creating both samples and distributions.
def _flat_sample_distributions(self, sample_shape=(), seed=None, value=None): """Executes `model`, creating both samples and distributions.""" ds = [] values_out = [] seed = seed_stream.SeedStream('JointDistributionCoroutine', seed) gen = self._model() index = 0 d = next(gen) try: ...
Calculate the batched KL divergence KL ( a || b ) with a and b Pareto.
def _kl_pareto_pareto(a, b, name=None): """Calculate the batched KL divergence KL(a || b) with a and b Pareto. Args: a: instance of a Pareto distribution object. b: instance of a Pareto distribution object. name: (optional) Name to use for created operations. default is "kl_pareto_pareto". Ret...
Returns f ( x ) if x is in the support and alt otherwise.
def _extend_support(self, x, f, alt): """Returns `f(x)` if x is in the support, and `alt` otherwise. Given `f` which is defined on the support of this distribution (e.g. x > scale), extend the function definition to the real line by defining `f(x) = alt` for `x < scale`. Args: x: Floating-po...
Latent Dirichlet Allocation in terms of its generative process.
def latent_dirichlet_allocation(concentration, topics_words): """Latent Dirichlet Allocation in terms of its generative process. The model posits a distribution over bags of words and is parameterized by a concentration and the topic-word probabilities. It collapses per-word topic assignments. Args: con...
Creates the variational distribution for LDA.
def make_lda_variational(activation, num_topics, layer_sizes): """Creates the variational distribution for LDA. Args: activation: Activation function to use. num_topics: The number of topics. layer_sizes: The number of hidden units per layer in the encoder. Returns: lda_variational: A function t...
Builds the model function for use in an Estimator.
def model_fn(features, labels, mode, params, config): """Builds the model function for use in an Estimator. Arguments: features: The input features for the Estimator. labels: The labels, unused here. mode: Signifies whether it is train or test or predict. params: Some hyperparameters as a dictionar...
Returns the summary of the learned topics.
def get_topics_strings(topics_words, alpha, vocabulary, topics_to_print=10, words_per_topic=10): """Returns the summary of the learned topics. Arguments: topics_words: KxV tensor with topics as rows and words as columns. alpha: 1xK tensor of prior Dirichlet concentrations for the ...
20 newsgroups as a tf. data. Dataset.
def newsgroups_dataset(directory, split_name, num_words, shuffle_and_repeat): """20 newsgroups as a tf.data.Dataset.""" data = np.load(download(directory, FILE_TEMPLATE.format(split=split_name))) # The last row is empty in both train and test. data = data[:-1] # Each row is a list of word ids in the document...
Builds fake data for unit testing.
def build_fake_input_fns(batch_size): """Builds fake data for unit testing.""" num_words = 1000 vocabulary = [str(i) for i in range(num_words)] random_sample = np.random.randint( 10, size=(batch_size, num_words)).astype(np.float32) def train_input_fn(): dataset = tf.data.Dataset.from_tensor_slices...
Builds iterators for train and evaluation data.
def build_input_fns(data_dir, batch_size): """Builds iterators for train and evaluation data. Each object is represented as a bag-of-words vector. Arguments: data_dir: Folder in which to store the data. batch_size: Batch size for both train and evaluation. Returns: train_input_fn: A function that...
Calculate the batched KL divergence KL ( a || b ) with a and b Chi.
def _kl_chi_chi(a, b, name=None): """Calculate the batched KL divergence KL(a || b) with a and b Chi. Args: a: instance of a Chi distribution object. b: instance of a Chi distribution object. name: (optional) Name to use for created operations. default is "kl_chi_chi". Returns: Batchwise K...
Returns a ( dense ) column of a Tensor or SparseTensor.
def _sparse_or_dense_matmul_onehot(sparse_or_dense_matrix, col_index): """Returns a (dense) column of a Tensor or SparseTensor. Args: sparse_or_dense_matrix: matrix-shaped, `float` `Tensor` or `SparseTensor`. col_index: scalar, `int` `Tensor` representing the index of the desired column. Returns: ...
One step of ( the outer loop of ) the minimization algorithm.
def minimize_one_step(gradient_unregularized_loss, hessian_unregularized_loss_outer, hessian_unregularized_loss_middle, x_start, tolerance, l1_regularizer, l2_regularizer=None, ...
Minimize using Hessian - informed proximal gradient descent.
def minimize(grad_and_hessian_loss_fn, x_start, tolerance, l1_regularizer, l2_regularizer=None, maximum_iterations=1, maximum_full_sweeps_per_iteration=1, learning_rate=None, name=None): """Minimize using Hessian-i...
Creates the encoder function.
def make_encoder(base_depth, activation, latent_size, code_size): """Creates the encoder function. Args: base_depth: Layer base depth in encoder net. activation: Activation function in hidden layers. latent_size: The number of latent variables in the code. code_size: The dimensionality of each late...
Creates the decoder function.
def make_decoder(base_depth, activation, input_size, output_shape): """Creates the decoder function. Args: base_depth: Layer base depth in decoder net. activation: Activation function in hidden layers. input_size: The flattened latent input shape as an int. output_shape: The output image shape as a...
Add control dependencies to the commmitment loss to update the codebook.
def add_ema_control_dependencies(vector_quantizer, one_hot_assignments, codes, commitment_loss, decay): """Add control dependencies to the commmitment loss to update the codebook. Arg...
Helper method to save a grid of images to a PNG file.
def save_imgs(x, fname): """Helper method to save a grid of images to a PNG file. Args: x: A numpy array of shape [n_images, height, width]. fname: The filename to write to (including extension). """ n = x.shape[0] fig = figure.Figure(figsize=(n, 1), frameon=False) canvas = backend_agg.FigureCanvas...
Helper method to save images visualizing model reconstructions.
def visualize_training(images_val, reconstructed_images_val, random_images_val, log_dir, prefix, viz_n=10): """Helper method to save images visualizing model reconstructions. Args: images_val: Numpy array containing a batch of input images. ...
Returns Hugo Larochelle s binary static MNIST tf. data. Dataset.
def load_bernoulli_mnist_dataset(directory, split_name): """Returns Hugo Larochelle's binary static MNIST tf.data.Dataset.""" amat_file = download(directory, FILE_TEMPLATE.format(split=split_name)) dataset = tf.data.TextLineDataset(amat_file) str_to_arr = lambda string: np.array([c == b"1" for c in string.split...
Builds an Iterator switching between train and heldout data.
def build_input_pipeline(data_dir, batch_size, heldout_size, mnist_type): """Builds an Iterator switching between train and heldout data.""" # Build an iterator over training batches. if mnist_type in [MnistType.FAKE_DATA, MnistType.THRESHOLD]: if mnist_type == MnistType.FAKE_DATA: mnist_data = build_fa...
Returns a np. dtype based on this dtype.
def as_numpy_dtype(dtype): """Returns a `np.dtype` based on this `dtype`.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'as_numpy_dtype'): return dtype.as_numpy_dtype return dtype
Returns a non - reference dtype based on this dtype.
def base_dtype(dtype): """Returns a non-reference `dtype` based on this `dtype`.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'base_dtype'): return dtype.base_dtype return dtype
Returns whether this is a boolean data type.
def is_bool(dtype): """Returns whether this is a boolean data type.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'is_bool'): return dtype.is_bool # We use `kind` because: # np.issubdtype(np.uint8, np.bool) == True. return np.dtype(dtype).kind == 'b'
Returns whether this is a complex floating point type.
def is_complex(dtype): """Returns whether this is a complex floating point type.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'is_complex'): return dtype.is_complex return np.issubdtype(np.dtype(dtype), np.complex)
Returns whether this is a ( non - quantized real ) floating point type.
def is_floating(dtype): """Returns whether this is a (non-quantized, real) floating point type.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'is_floating'): return dtype.is_floating return np.issubdtype(np.dtype(dtype), np.float)
Returns whether this is a ( non - quantized ) integer type.
def is_integer(dtype): """Returns whether this is a (non-quantized) integer type.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'is_integer'): return dtype.is_integer return np.issubdtype(np.dtype(dtype), np.integer)
Returns the maximum representable value in this data type.
def max(dtype): # pylint: disable=redefined-builtin """Returns the maximum representable value in this data type.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'max'): return dtype.max use_finfo = is_floating(dtype) or is_complex(dtype) return np.finfo(dtype).max if use_finfo else np.iinfo(dtype).max
Returns the string name for this dtype.
def name(dtype): """Returns the string name for this `dtype`.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'name'): return dtype.name if hasattr(dtype, '__name__'): return dtype.__name__ return str(dtype)
Returns the number of bytes to represent this dtype.
def size(dtype): """Returns the number of bytes to represent this `dtype`.""" dtype = tf.as_dtype(dtype) if hasattr(dtype, 'size'): return dtype.size return np.dtype(dtype).itemsize
r Asserts all items are of the same base type.
def _assert_same_base_type(items, expected_type=None): r"""Asserts all items are of the same base type. Args: items: List of graph items (e.g., `Variable`, `Tensor`, `SparseTensor`, `Operation`, or `IndexedSlices`). Can include `None` elements, which will be ignored. expected_type: Expected...
Validate and return float type based on tensors and dtype.
def assert_same_float_dtype(tensors=None, dtype=None): """Validate and return float type based on `tensors` and `dtype`. For ops such as matrix multiplication, inputs and weights must be of the same float type. This function validates that all `tensors` are the same type, validates that type is `dtype` (if sup...
Calculate the batched KL divergence KL ( a || b ) with a b OneHotCategorical.
def _kl_categorical_categorical(a, b, name=None): """Calculate the batched KL divergence KL(a || b) with a, b OneHotCategorical. Args: a: instance of a OneHotCategorical distribution object. b: instance of a OneHotCategorical distribution object. name: (optional) Name to use for created operations. ...
Minimum of the objective function using the Nelder Mead simplex algorithm.
def minimize(objective_function, initial_simplex=None, initial_vertex=None, step_sizes=None, objective_at_initial_simplex=None, objective_at_initial_vertex=None, batch_evaluate_objective=False, func_tolerance=1e-8, p...
A single iteration of the Nelder Mead algorithm.
def nelder_mead_one_step(current_simplex, current_objective_values, objective_function=None, dim=None, func_tolerance=None, position_tolerance=None, batch_evaluate_object...
Creates the condition function pair for a reflection to be accepted.
def _accept_reflected_fn(simplex, objective_values, worst_index, reflected, objective_at_reflected): """Creates the condition function pair for a reflection to be accepted.""" def _replace_worst_with_reflected(): ...
Creates the condition function pair for an expansion.
def _expansion_fn(objective_function, simplex, objective_values, worst_index, reflected, objective_at_reflected, face_centroid, expansion): """Creates the condition function pair for an expans...
Creates the condition function pair for an outside contraction.
def _outside_contraction_fn(objective_function, simplex, objective_values, face_centroid, best_index, worst_index, reflected, ...
Shrinks the simplex around the best vertex.
def _shrink_towards_best(objective_function, simplex, best_index, shrinkage, batch_evaluate_objective): """Shrinks the simplex around the best vertex.""" # If the contraction step fails to improve the average object...
Replaces an element at supplied index.
def _replace_at_index(x, index, replacement): """Replaces an element at supplied index.""" x_new = tf.concat([x[:index], tf.expand_dims(replacement, axis=0), x[(index + 1):]], axis=0) return x_new
Returns True if the simplex has converged.
def _check_convergence(simplex, best_vertex, best_objective, worst_objective, func_tolerance, position_tolerance): """Returns True if the simplex has converged. If the simplex size is smaller than the...
Computes the initial simplex and the objective values at the simplex.
def _prepare_args(objective_function, initial_simplex, initial_vertex, step_sizes, objective_at_initial_simplex, objective_at_initial_vertex, batch_evaluate_objective): """Computes the initial simplex and the o...
Chooses default step sizes according to [ Gao and Han ( 2010 ) ] [ 3 ].
def _default_step_sizes(reference_vertex): """Chooses default step sizes according to [Gao and Han(2010)][3].""" # Step size to choose when the coordinate is zero. small_sizes = tf.ones_like(reference_vertex) * 0.00025 # Step size to choose when the coordinate is non-zero. large_sizes = reference_vertex * 0.0...
Evaluates the objective function at the specified initial simplex.
def _prepare_args_with_initial_simplex(objective_function, initial_simplex, objective_at_initial_simplex, batch_evaluate_objective): """Evaluates the objective function at the specified initial simplex...
Constructs a standard axes aligned simplex.
def _prepare_args_with_initial_vertex(objective_function, initial_vertex, step_sizes, objective_at_initial_vertex, batch_evaluate_objective): """Constructs a standard...
Applies the [ Gao and Han ] [ 3 ] presciption to the unspecified parameters.
def _resolve_parameters(dim, reflection, expansion, contraction, shrinkage, dtype): """Applies the [Gao and Han][3] presciption to the unspecified parameters.""" dim = tf.cast(dim, dtype=dtype) ...
Evaluates the objective function on a batch of points.
def _evaluate_objective_multiple(objective_function, arg_batch, batch_evaluate_objective): """Evaluates the objective function on a batch of points. If `batch_evaluate_objective` is True, returns `objective function(arg_batch)` else it maps the `objective_function` across the `...
Save a PNG plot with histograms of weight means and stddevs.
def plot_weight_posteriors(names, qm_vals, qs_vals, fname): """Save a PNG plot with histograms of weight means and stddevs. Args: names: A Python `iterable` of `str` variable names. qm_vals: A Python `iterable`, the same length as `names`, whose elements are Numpy `array`s, of any shape, containing ...
Save a PNG plot visualizing posterior uncertainty on heldout data.
def plot_heldout_prediction(input_vals, probs, fname, n=10, title=""): """Save a PNG plot visualizing posterior uncertainty on heldout data. Args: input_vals: A `float`-like Numpy `array` of shape `[num_heldout] + IMAGE_SHAPE`, containing heldout input images. probs: A `fl...
Build an Iterator switching between train and heldout data.
def build_input_pipeline(mnist_data, batch_size, heldout_size): """Build an Iterator switching between train and heldout data.""" # Build an iterator over training batches. training_dataset = tf.data.Dataset.from_tensor_slices( (mnist_data.train.images, np.int32(mnist_data.train.labels))) training_batche...
Build fake MNIST - style data for unit testing.
def build_fake_data(num_examples=10): """Build fake MNIST-style data for unit testing.""" class Dummy(object): pass num_examples = 10 mnist_data = Dummy() mnist_data.train = Dummy() mnist_data.train.images = np.float32(np.random.randn( num_examples, *IMAGE_SHAPE)) mnist_data.train.labels = np....
Calculate the batched KL divergence KL ( a || b ) with a and b Bernoulli.
def _kl_bernoulli_bernoulli(a, b, name=None): """Calculate the batched KL divergence KL(a || b) with a and b Bernoulli. Args: a: instance of a Bernoulli distribution object. b: instance of a Bernoulli distribution object. name: (optional) Name to use for created operations. default is "kl_bernoul...
Returns initializer configuration as a JSON - serializable dict.
def get_config(self): """Returns initializer configuration as a JSON-serializable dict.""" return { 'initializers': [ tf.compat.v2.initializers.serialize( tf.keras.initializers.get(init)) for init in self.initializers ], 'sizes': self.sizes, ...
Instantiates an initializer from a configuration dictionary.
def from_config(cls, config): """Instantiates an initializer from a configuration dictionary.""" return cls(**{ 'initializers': [tf.compat.v2.initializers.deserialize(init) for init in config.get('initializers', [])], 'sizes': config.get('sizes', []), 'validate_a...
Numpy matmul wrapper.
def _matmul(a, b, transpose_a=False, transpose_b=False, adjoint_a=False, adjoint_b=False, a_is_sparse=False, b_is_sparse=False, name=None): # pylint: disable=unused-argument """Numpy matmul wrapper.""" if a_is_sparse or b_is_sparse: raise NotImplementedError('Num...
Helper to compute stddev covariance and variance.
def _std_var_helper(self, statistic, statistic_name, statistic_ndims, df_factor_fn): """Helper to compute stddev, covariance and variance.""" df = tf.reshape( self.df, tf.concat([ tf.shape(input=self.df), tf.ones([statistic_ndims], dtype=tf.int32) ...
Compute exponentially weighted moving { mean variance } of a streaming value.
def assign_moving_mean_variance( mean_var, variance_var, value, decay, name=None): """Compute exponentially weighted moving {mean,variance} of a streaming value. The `value` updated exponentially weighted moving `mean_var` and `variance_var` are given by the following recurrence relations: ```python var...
Compute the log of the exponentially weighted moving mean of the exp.
def assign_log_moving_mean_exp( log_mean_exp_var, log_value, decay, name=None): """Compute the log of the exponentially weighted moving mean of the exp. If `log_value` is a draw from a stationary random variable, this function approximates `log(E[exp(log_value)])`, i.e., a weighted log-sum-exp. More precis...
Compute exponentially weighted moving { mean variance } of a streaming value.
def moving_mean_variance(value, decay, name=None): """Compute exponentially weighted moving {mean,variance} of a streaming value. The exponentially-weighting moving `mean_var` and `variance_var` are updated by `value` according to the following recurrence: ```python variance_var = decay * (variance_var + (1...
Ensures non - scalar input has at least one column.
def _make_columnar(self, x): """Ensures non-scalar input has at least one column. Example: If `x = [1, 2, 3]` then the output is `[[1], [2], [3]]`. If `x = [[1, 2, 3], [4, 5, 6]]` then the output is unchanged. If `x = 1` then the output is unchanged. Args: x: `Tensor`. Retur...
Calculate the batched KL divergence KL ( a || b ) with a and b Laplace.
def _kl_laplace_laplace(a, b, name=None): """Calculate the batched KL divergence KL(a || b) with a and b Laplace. Args: a: instance of a Laplace distribution object. b: instance of a Laplace distribution object. name: (optional) Name to use for created operations. default is "kl_laplace_laplace"....
Generates Tensor consisting of - 1 or + 1 chosen uniformly at random.
def random_rademacher(shape, dtype=tf.float32, seed=None, name=None): """Generates `Tensor` consisting of `-1` or `+1`, chosen uniformly at random. For more details, see [Rademacher distribution]( https://en.wikipedia.org/wiki/Rademacher_distribution). Args: shape: Vector-shaped, `int` `Tensor` representi...
Generates Tensor of positive reals drawn from a Rayleigh distributions.
def random_rayleigh(shape, scale=None, dtype=tf.float32, seed=None, name=None): """Generates `Tensor` of positive reals drawn from a Rayleigh distributions. The probability density function of a Rayleigh distribution with `scale` parameter is given by: ```none f(x) = x scale**-2 exp(-x**2 0.5 scale**-2) `...
Convenience function which chooses the condition based on the predicate.
def _pick_scalar_condition(pred, cond_true, cond_false): """Convenience function which chooses the condition based on the predicate.""" # Note: This function is only valid if all of pred, cond_true, and cond_false # are scalars. This means its semantics are arguably more like tf.cond than # tf.where even though...
Finish computation of log_prob on one element of the inverse image.
def _finish_log_prob_for_one_fiber(self, y, x, ildj, event_ndims, **distribution_kwargs): """Finish computation of log_prob on one element of the inverse image.""" x = self._maybe_rotate_dims(x, rotate_right=True) log_prob = self.distribution.log_prob(x, **distribution_k...
Finish computation of prob on one element of the inverse image.
def _finish_prob_for_one_fiber(self, y, x, ildj, event_ndims, **distribution_kwargs): """Finish computation of prob on one element of the inverse image.""" x = self._maybe_rotate_dims(x, rotate_right=True) prob = self.distribution.prob(x, **distribution_kwargs) if self._...
Helper to __init__ which ensures override batch/ event_shape are valid.
def _maybe_validate_shape_override(self, override_shape, base_is_scalar, validate_args, name): """Helper to __init__ which ensures override batch/event_shape are valid.""" if override_shape is None: override_shape = [] override_shape = tf.convert_to_tensor( ...
Helper which rolls left event_dims left or right event_dims right.
def _maybe_rotate_dims(self, x, rotate_right=False): """Helper which rolls left event_dims left or right event_dims right.""" needs_rotation_const = tf.get_static_value(self._needs_rotation) if needs_rotation_const is not None and not needs_rotation_const: return x ndims = prefer_static.rank(x) ...
r Inverse of tf. nn. batch_normalization.
def _undo_batch_normalization(x, mean, variance, offset, scale, variance_epsilon, name=None): r"""Inverse of tf.nn.batch_normalization. ...
Check for valid BatchNormalization layer.
def _validate_bn_layer(self, layer): """Check for valid BatchNormalization layer. Args: layer: Instance of `tf.layers.BatchNormalization`. Raises: ValueError: If batchnorm_layer argument is not an instance of `tf.layers.BatchNormalization`, or if `batchnorm_layer.renorm=True` or if ...
Slices a single parameter of a distribution.
def _slice_single_param(param, param_event_ndims, slices, dist_batch_shape): """Slices a single parameter of a distribution. Args: param: A `Tensor`, the original parameter to slice. param_event_ndims: `int` event parameterization rank for this parameter. slices: A `tuple` of normalized slices. dis...
Computes the override dictionary of sliced parameters.
def _slice_params_to_dict(dist, params_event_ndims, slices): """Computes the override dictionary of sliced parameters. Args: dist: The tfd.Distribution being batch-sliced. params_event_ndims: Per-event parameter ranks, a `str->int` `dict`. slices: Slices as received by __getitem__. Returns: over...
Applies a single slicing step to dist returning a new instance.
def _apply_single_step(dist, params_event_ndims, slices, params_overrides): """Applies a single slicing step to `dist`, returning a new instance.""" if len(slices) == 1 and slices[0] == Ellipsis: # The path used by Distribution.copy: batch_slice(...args..., Ellipsis) override_dict = {} else: override_...
Applies a sequence of slice or copy - with - overrides operations to dist.
def _apply_slice_sequence(dist, params_event_ndims, slice_overrides_seq): """Applies a sequence of slice or copy-with-overrides operations to `dist`.""" for slices, overrides in slice_overrides_seq: dist = _apply_single_step(dist, params_event_ndims, slices, overrides) return dist
Slices dist along its batch dimensions. Helper for tfd. Distribution.
def batch_slice(dist, params_event_ndims, params_overrides, slices): """Slices `dist` along its batch dimensions. Helper for tfd.Distribution. Args: dist: A `tfd.Distribution` instance. params_event_ndims: A `dict` of `str->int` indicating the number of dimensions of a given parameter required to par...