## Class MaskedLSTMCell

Inherits From: LSTMCell

LSTMCell with pruning.

Overrides the call method of tensorflow LSTMCell and injects the weight masks. Masks are applied to only the weight matrix of the LSTM and not the projection matrix.

## Properties

### activity_regularizer

Optional regularizer function for the output of this layer.

### input

Retrieves the input tensor(s) of a layer.

Only applicable if the layer has exactly one input, i.e. if it is connected to one incoming layer.

#### Returns:

Input tensor or list of input tensors.

#### Raises:

• AttributeError: if the layer is connected to more than one incoming layers.

#### Raises:

• RuntimeError: If called in Eager mode.
• AttributeError: If no inbound nodes are found.

### input_shape

Retrieves the input shape(s) of a layer.

Only applicable if the layer has exactly one input, i.e. if it is connected to one incoming layer, or if all inputs have the same shape.

#### Returns:

Input shape, as an integer shape tuple (or list of shape tuples, one tuple per input tensor).

#### Raises:

• AttributeError: if the layer has no defined input_shape.
• RuntimeError: if called in Eager mode.

### losses

Losses which are associated with this Layer.

Note that when executing eagerly, getting this property evaluates regularizers. When using graph execution, variable regularization ops have already been created and are simply returned here.

#### Returns:

A list of tensors.

### output

Retrieves the output tensor(s) of a layer.

Only applicable if the layer has exactly one output, i.e. if it is connected to one incoming layer.

#### Returns:

Output tensor or list of output tensors.

#### Raises:

• AttributeError: if the layer is connected to more than one incoming layers.
• RuntimeError: if called in Eager mode.

### output_shape

Retrieves the output shape(s) of a layer.

Only applicable if the layer has one output, or if all outputs have the same shape.

#### Returns:

Output shape, as an integer shape tuple (or list of shape tuples, one tuple per output tensor).

#### Raises:

• AttributeError: if the layer has no defined output shape.
• RuntimeError: if called in Eager mode.

### variables

Returns the list of all layer variables/weights.

#### Returns:

A list of variables.

### weights

Returns the list of all layer variables/weights.

#### Returns:

A list of variables.

## Methods

### __init__

__init__(
num_units,
use_peepholes=False,
cell_clip=None,
initializer=None,
num_proj=None,
proj_clip=None,
num_unit_shards=None,
num_proj_shards=None,
forget_bias=1.0,
state_is_tuple=True,
activation=None,
reuse=None
)


Initialize the parameters for an LSTM cell with masks for pruning.

#### Args:

• num_units: int, The number of units in the LSTM cell
• use_peepholes: bool, set True to enable diagonal/peephole connections.
• cell_clip: (optional) A float value, if provided the cell state is clipped by this value prior to the cell output activation.
• initializer: (optional) The initializer to use for the weight and projection matrices.
• num_proj: (optional) int, The output dimensionality for the projection matrices. If None, no projection is performed.
• proj_clip: (optional) A float value. If num_proj > 0 and proj_clip is provided, then the projected values are clipped elementwise to within [-proj_clip, proj_clip].
• num_unit_shards: Deprecated, will be removed by Jan. 2017. Use a variable_scope partitioner instead.
• num_proj_shards: Deprecated, will be removed by Jan. 2017. Use a variable_scope partitioner instead.
• forget_bias: Biases of the forget gate are initialized by default to 1 in order to reduce the scale of forgetting at the beginning of the training. Must set it manually to 0.0 when restoring from CudnnLSTM trained checkpoints.
• state_is_tuple: If True, accepted and returned states are 2-tuples of the c_state and m_state. If False, they are concatenated along the column axis. This latter behavior will soon be deprecated.
• activation: Activation function of the inner states. Default: tanh.
• reuse: (optional) Python boolean describing whether to reuse variables in an existing scope. If not True, and the existing scope already has the given variables, an error is raised.

When restoring from CudnnLSTM-trained checkpoints, must use CudnnCompatibleLSTMCell instead.

### __call__

__call__(
inputs,
state,
scope=None,
*args,
**kwargs
)


Run this RNN cell on inputs, starting from the given state.

#### Args:

• inputs: 2-D tensor with shape [batch_size, input_size].
• state: if self.state_size is an integer, this should be a 2-D Tensor with shape [batch_size, self.state_size]. Otherwise, if self.state_size is a tuple of integers, this should be a tuple with shapes [batch_size, s] for s in self.state_size.
• scope: optional cell scope.
• *args: Additional positional arguments.
• **kwargs: Additional keyword arguments.

#### Returns:

A pair containing:

• Output: A 2-D tensor with shape [batch_size, self.output_size].
• New state: Either a single 2-D tensor, or a tuple of tensors matching the arity and shapes of state.

### __deepcopy__

__deepcopy__(memo)


### add_loss

add_loss(
losses,
inputs=None
)


Add loss tensor(s), potentially dependent on layer inputs.

Some losses (for instance, activity regularization losses) may be dependent on the inputs passed when calling a layer. Hence, when reusing the same layer on different inputs a and b, some entries in layer.losses may be dependent on a and some on b. This method automatically keeps track of dependencies.

The get_losses_for method allows to retrieve the losses relevant to a specific set of inputs.

Note that add_loss is not supported when executing eagerly. Instead, variable regularizers may be added through add_variable. Activity regularization is not supported directly (but such losses may be returned from Layer.call()).

#### Arguments:

• losses: Loss tensor, or list/tuple of tensors.
• inputs: If anything other than None is passed, it signals the losses are conditional on some of the layer's inputs, and thus they should only be run where these inputs are available. This is the case for activity regularization losses, for instance. If None is passed, the losses are assumed to be unconditional, and will apply across all dataflows of the layer (e.g. weight regularization losses).

#### Raises:

• RuntimeError: If called in Eager mode.

### add_update

add_update(
inputs=None
)


Add update op(s), potentially dependent on layer inputs.

Weight updates (for instance, the updates of the moving mean and variance in a BatchNormalization layer) may be dependent on the inputs passed when calling a layer. Hence, when reusing the same layer on different inputs a and b, some entries in layer.updates may be dependent on a and some on b. This method automatically keeps track of dependencies.

The get_updates_for method allows to retrieve the updates relevant to a specific set of inputs.

This call is ignored in Eager mode.

#### Arguments:

• updates: Update op, or list/tuple of update ops.
• inputs: If anything other than None is passed, it signals the updates are conditional on some of the layer's inputs, and thus they should only be run where these inputs are available. This is the case for BatchNormalization updates, for instance. If None, the updates will be taken into account unconditionally, and you are responsible for making sure that any dependency they might have is available at runtime. A step counter might fall into this category.

### add_variable

add_variable(
name,
shape,
dtype=None,
initializer=None,
regularizer=None,
trainable=True,
constraint=None,
partitioner=None
)


Adds a new variable to the layer, or gets an existing one; returns it.

#### Arguments:

• name: variable name.
• shape: variable shape.
• dtype: The type of the variable. Defaults to self.dtype or float32.
• initializer: initializer instance (callable).
• regularizer: regularizer instance (callable).
• trainable: whether the variable should be part of the layer's "trainable_variables" (e.g. variables, biases) or "non_trainable_variables" (e.g. BatchNorm mean, stddev). Note, if the current variable scope is marked as non-trainable then this parameter is ignored and any added variables are also marked as non-trainable.
• constraint: constraint instance (callable).
• partitioner: (optional) partitioner instance (callable). If provided, when the requested variable is created it will be split into multiple partitions according to partitioner. In this case, an instance of PartitionedVariable is returned. Available partitioners include tf.fixed_size_partitioner and tf.variable_axis_size_partitioner. For more details, see the documentation of tf.get_variable and the "Variable Partitioners and Sharding" section of the API guide.

#### Returns:

The created variable. Usually either a Variable or ResourceVariable instance. If partitioner is not None, a PartitionedVariable instance is returned.

#### Raises:

• RuntimeError: If called with partioned variable regularization and eager execution is enabled.

### apply

apply(
inputs,
*args,
**kwargs
)


Apply the layer on a input.

This simply wraps self.__call__.

#### Arguments:

• inputs: Input tensor(s).
• *args: additional positional arguments to be passed to self.call.
• **kwargs: additional keyword arguments to be passed to self.call.

#### Returns:

Output tensor(s).

### build

build(inputs_shape)


### call

call(
inputs,
state
)


Run one step of LSTM.

#### Args:

• inputs: input Tensor, 2D, [batch, num_units].
• state: if state_is_tuple is False, this must be a state Tensor, 2-D, [batch, state_size]. If state_is_tuple is True, this must be a tuple of state Tensors, both 2-D, with column sizes c_state and m_state.

#### Returns:

A tuple containing:

• A 2-D, [batch, output_dim], Tensor representing the output of the LSTM after reading inputs when previous state was state. Here output_dim is: num_proj if num_proj was set, num_units otherwise.
• Tensor(s) representing the new state of LSTM after reading inputs when the previous state was state. Same type and shape(s) as state.

#### Raises:

• ValueError: If input size cannot be inferred from inputs via static shape inference.

### compute_output_shape

compute_output_shape(input_shape)


Computes the output shape of the layer given the input shape.

#### Args:

• input_shape: A (possibly nested tuple of) TensorShape. It need not be fully defined (e.g. the batch size may be unknown).

#### Returns:

A (possibly nested tuple of) TensorShape.

#### Raises:

• TypeError: if input_shape is not a (possibly nested tuple of) TensorShape.
• ValueError: if input_shape is incomplete or is incompatible with the the layer.

### count_params

count_params()


Count the total number of scalars composing the weights.

#### Returns:

An integer count.

#### Raises:

• ValueError: if the layer isn't yet built (in which case its weights aren't yet defined).

### get_input_at

get_input_at(node_index)


Retrieves the input tensor(s) of a layer at a given node.

#### Arguments:

• node_index: Integer, index of the node from which to retrieve the attribute. E.g. node_index=0 will correspond to the first time the layer was called.

#### Returns:

A tensor (or list of tensors if the layer has multiple inputs).

#### Raises:

• RuntimeError: If called in Eager mode.

### get_input_shape_at

get_input_shape_at(node_index)


Retrieves the input shape(s) of a layer at a given node.

#### Arguments:

• node_index: Integer, index of the node from which to retrieve the attribute. E.g. node_index=0 will correspond to the first time the layer was called.

#### Returns:

A shape tuple (or list of shape tuples if the layer has multiple inputs).

#### Raises:

• RuntimeError: If called in Eager mode.

### get_losses_for

get_losses_for(inputs)


Retrieves losses relevant to a specific set of inputs.

#### Arguments:

• inputs: Input tensor or list/tuple of input tensors.

#### Returns:

List of loss tensors of the layer that depend on inputs.

#### Raises:

• RuntimeError: If called in Eager mode.

### get_output_at

get_output_at(node_index)


Retrieves the output tensor(s) of a layer at a given node.

#### Arguments:

• node_index: Integer, index of the node from which to retrieve the attribute. E.g. node_index=0 will correspond to the first time the layer was called.

#### Returns:

A tensor (or list of tensors if the layer has multiple outputs).

#### Raises:

• RuntimeError: If called in Eager mode.

### get_output_shape_at

get_output_shape_at(node_index)


Retrieves the output shape(s) of a layer at a given node.

#### Arguments:

• node_index: Integer, index of the node from which to retrieve the attribute. E.g. node_index=0 will correspond to the first time the layer was called.

#### Returns:

A shape tuple (or list of shape tuples if the layer has multiple outputs).

#### Raises:

• RuntimeError: If called in Eager mode.

### get_updates_for

get_updates_for(inputs)


Retrieves updates relevant to a specific set of inputs.

#### Arguments:

• inputs: Input tensor or list/tuple of input tensors.

#### Returns:

List of update ops of the layer that depend on inputs.

#### Raises:

• RuntimeError: If called in Eager mode.

### zero_state

zero_state(
batch_size,
dtype
)


Return zero-filled state tensor(s).

#### Args:

• batch_size: int, float, or unit Tensor representing the batch size.
• dtype: the data type to use for the state.

#### Returns:

If state_size is an int or TensorShape, then the return value is a N-D tensor of shape [batch_size, state_size] filled with zeros.

If state_size is a nested list or tuple, then the return value is a nested list or tuple (of the same structure) of 2-D tensors with the shapes [batch_size, s] for each s in state_size`.