UGRNN

UGRNN(input_size => hidden_size;
    return_state = false, kwargs...)

Update gate recurrent neural network (Collins et al., 2017). See UGRNNCell for a layer that processes a single sequence.

Arguments

• input_size => hidden_size: input and inner dimension of the layer

Keyword arguments

• return_state: Option to return the last state together with the output. Default is false.
• init_kernel: initializer for the input to hidden weights. Default is glorot_uniform.
• init_recurrent_kernel: initializer for the hidden to hidden weights. Default is glorot_uniform.
• bias: include a bias or not. Default is true.

Equations

\[\begin{aligned} \mathbf{c}(t) &= s\left( \mathbf{W}_{hh}^c \, \mathbf{h}(t-1) + \mathbf{W}_{xh}^c \, \mathbf{x}(t) + \mathbf{b}^c \right), \\ \mathbf{g}(t) &= \sigma\left( \mathbf{W}_{hh}^g \, \mathbf{h}(t-1) + \mathbf{W}_{xh}^g \, \mathbf{x}(t) + \mathbf{b}^g \right), \\ \mathbf{h}(t) &= \mathbf{g}(t) \circ \mathbf{h}(t-1) + \left( 1 - \mathbf{g}(t) \right) \circ \mathbf{c}(t). \end{aligned}\]

Forward

ugrnn(inp, state)
ugrnn(inp)

Arguments

• inp: The input to the ugrnn. It should be a vector of size input_size x len or a matrix of size input_size x len x batch_size.
• state: The hidden state of the UGRNN. If given, it is a vector of size hidden_size or a matrix of size hidden_size x batch_size. If not provided, it is assumed to be a vector of zeros, initialized by Flux.initialstates.

Returns

• New hidden states new_states as an array of size hidden_size x len x batch_size. When return_state = true it returns a tuple of the hidden stats new_states and the last state of the iteration.