import numpy as np
import keras.backend as K
from keras.layers import Layer, merge, RepeatVector
class InteractionRNN(Layer):
""" output response of two input tensors """
def __init__(self, RNN, num_steps, DNN=None, **kwargs):
self.RNN = RNN
self.num_steps = num_steps
self.DNN = DNN
super(InteractionRNN, self).__init__(**kwargs)
def get_output_shape_for(self, input_shape):
return (None, 1)
def call(self, x, mask=None):
U, V = x[0], x[1]
x = merge([U, V], mode='concat', dot_axes=[1, 1])
x = RepeatVector(self.num_steps)(x)
response = self.RNN(x)
if self.DNN is not None:
response = self.DNN(response)
return response
