tf.keras.layers.SimpleRNN

Fully-connected RNN where the output is to be fed back to input.

Inherits From: RNN

Used in the notebooks

Used in the guide

See the Keras RNN API guide for details about the usage of RNN API.

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.
activity_regularizer Regularizer function applied to the output of the layer (its "activation"). 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.
return_sequences Boolean. Whether to return the last output in the output sequence, or the full sequence. Default: False.
return_state Boolean. Whether to return the last state in addition to the output. Default: False
go_backwards Boolean (default False). If True, process the input sequence backwards and return the reversed sequence.
stateful Boolean (default False). If True, the last state for each sample at index i in a batch will be used as initial state for the sample of index i in the following batch.
unroll Boolean (default False). If True, the network will be unrolled, else a symbolic loop will be used. Unrolling can speed-up a RNN, although it tends to be more memory-intensive. Unrolling is only suitable for short sequences.

Call arguments:

  • inputs: A 3D tensor, with shape [batch, timesteps, feature].
  • mask: Binary tensor of shape [batch, timesteps] indicating whether a given timestep should be masked.
  • training: Python boolean indicating whether the layer should behave in training mode or in inference mode. This argument is passed to the cell when calling it. This is only relevant if dropout or recurrent_dropout is used.
  • initial_state: List of initial state tensors to be passed to the first call of the cell.

Examples:

inputs = np.random.random([32, 10, 8]).astype(np.float32)
simple_rnn = tf.keras.layers.SimpleRNN(4)

output = simple_rnn(inputs)  # The output has shape `[32, 4]`.

simple_rnn = tf.keras.layers.SimpleRNN(
    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 = simple_rnn(inputs)

activation

bias_constraint

bias_initializer

bias_regularizer

dropout

kernel_constraint

kernel_initializer

kernel_regularizer

recurrent_constraint

recurrent_dropout

recurrent_initializer

recurrent_regularizer

states

units