recurrent.py 文件源码

def get_output(self, train=False):
        X = self.get_input(train) # shape: (nb_samples, time (padded with zeros), input_dim)
        # new shape: (time, nb_samples, input_dim) -> because theano.scan iterates over main dimension
        padded_mask = self.get_padded_shuffled_mask(train, X, pad=1)
        X = X.dimshuffle((1, 0, 2)) 
        x = T.dot(X, self.W) + self.b

        # scan = theano symbolic loop.
        # See: http://deeplearning.net/software/theano/library/scan.html
        # Iterate over the first dimension of the x array (=time).
        outputs, updates = theano.scan(
            self._step, # this will be called with arguments (sequences[i], outputs[i-1], non_sequences[i])
            sequences=[x, dict(input=padded_mask, taps=[-1])], # tensors to iterate over, inputs to _step
            # initialization of the output. Input to _step with default tap=-1.
            outputs_info=T.unbroadcast(alloc_zeros_matrix(X.shape[1], self.output_dim), 1),
            non_sequences=self.U, # static inputs to _step
            truncate_gradient=self.truncate_gradient
        )

        if self.return_sequences:
            return outputs.dimshuffle((1, 0, 2))
        return outputs[-1]