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TensorFlow 1 version
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View source on GitHub
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Cell class for SimpleRNN.
tf.keras.layers.SimpleRNNCell(
units, activation='tanh', use_bias=True,
kernel_initializer='glorot_uniform',
recurrent_initializer='orthogonal',
bias_initializer='zeros', kernel_regularizer=None,
recurrent_regularizer=None, bias_regularizer=None, kernel_constraint=None,
recurrent_constraint=None, bias_constraint=None, dropout=0.0,
recurrent_dropout=0.0, **kwargs
)
See the Keras RNN API guide for details about the usage of RNN API.
This class processes one step within the whole time sequence input, whereas
tf.keras.layer.SimpleRNN processes the whole sequence.
Arguments | |
|---|---|
units
|
Positive integer, dimensionality of the output space. |
activation
|
Activation function to use.
Default: hyperbolic tangent (tanh).
If you pass None, no activation is applied
(ie. "linear" activation: a(x) = x).
|
use_bias
|
Boolean, (default True), whether the layer uses a bias vector.
|
kernel_initializer
|
Initializer for the kernel weights matrix,
used for the linear transformation of the inputs. Default:
glorot_uniform.
|
recurrent_initializer
|
Initializer for the recurrent_kernel
weights matrix, used for the linear transformation of the recurrent state.
Default: orthogonal.
|
bias_initializer
|
Initializer for the bias vector. Default: zeros.
|
kernel_regularizer
|
Regularizer function applied to the kernel weights
matrix. Default: None.
|
recurrent_regularizer
|
Regularizer function applied to the
recurrent_kernel weights matrix. Default: None.
|
bias_regularizer
|
Regularizer function applied to the bias vector. Default:
None.
|
kernel_constraint
|
Constraint function applied to the kernel weights
matrix. Default: None.
|
recurrent_constraint
|
Constraint function applied to the recurrent_kernel
weights matrix. Default: None.
|
bias_constraint
|
Constraint function applied to the bias vector. Default:
None.
|
dropout
|
Float between 0 and 1. Fraction of the units to drop for the linear transformation of the inputs. Default: 0. |
recurrent_dropout
|
Float between 0 and 1. Fraction of the units to drop for the linear transformation of the recurrent state. Default: 0. |
Call arguments:
inputs: A 2D tensor, with shape of[batch, feature].states: A 2D tensor with shape of[batch, units], which is the state from the previous time step. For timestep 0, the initial state provided by user will be feed to cell.training: Python boolean indicating whether the layer should behave in training mode or in inference mode. Only relevant whendropoutorrecurrent_dropoutis used.
Examples:
inputs = np.random.random([32, 10, 8]).astype(np.float32)
rnn = tf.keras.layers.RNN(tf.keras.layers.SimpleRNNCell(4))
output = rnn(inputs) # The output has shape `[32, 4]`.
rnn = tf.keras.layers.RNN(
tf.keras.layers.SimpleRNNCell(4),
return_sequences=True,
return_state=True)
# whole_sequence_output has shape `[32, 10, 4]`.
# final_state has shape `[32, 4]`.
whole_sequence_output, final_state = rnn(inputs)
Methods
get_dropout_mask_for_cell
get_dropout_mask_for_cell(
inputs, training, count=1
)
Get the dropout mask for RNN cell's input.
It will create mask based on context if there isn't any existing cached mask. If a new mask is generated, it will update the cache in the cell.
| Args | |
|---|---|
inputs
|
The input tensor whose shape will be used to generate dropout mask. |
training
|
Boolean tensor, whether its in training mode, dropout will be ignored in non-training mode. |
count
|
Int, how many dropout mask will be generated. It is useful for cell that has internal weights fused together. |
| Returns | |
|---|---|
| List of mask tensor, generated or cached mask based on context. |
get_initial_state
get_initial_state(
inputs=None, batch_size=None, dtype=None
)
get_recurrent_dropout_mask_for_cell
get_recurrent_dropout_mask_for_cell(
inputs, training, count=1
)
Get the recurrent dropout mask for RNN cell.
It will create mask based on context if there isn't any existing cached mask. If a new mask is generated, it will update the cache in the cell.
| Args | |
|---|---|
inputs
|
The input tensor whose shape will be used to generate dropout mask. |
training
|
Boolean tensor, whether its in training mode, dropout will be ignored in non-training mode. |
count
|
Int, how many dropout mask will be generated. It is useful for cell that has internal weights fused together. |
| Returns | |
|---|---|
| List of mask tensor, generated or cached mask based on context. |
reset_dropout_mask
reset_dropout_mask()
Reset the cached dropout masks if any.
This is important for the RNN layer to invoke this in it call() method so
that the cached mask is cleared before calling the cell.call(). The mask
should be cached across the timestep within the same batch, but shouldn't
be cached between batches. Otherwise it will introduce unreasonable bias
against certain index of data within the batch.
reset_recurrent_dropout_mask
reset_recurrent_dropout_mask()
Reset the cached recurrent dropout masks if any.
This is important for the RNN layer to invoke this in it call() method so that the cached mask is cleared before calling the cell.call(). The mask should be cached across the timestep within the same batch, but shouldn't be cached between batches. Otherwise it will introduce unreasonable bias against certain index of data within the batch.