pooling.py 文件源码

def call(self, x, mask=None):
        mean = super(IntraAttention, self).call(x, mask)
        # x: (batch_size, input_length, input_dim)
        # mean: (batch_size, input_dim)
        ones = K.expand_dims(K.mean(K.ones_like(x), axis=(0, 2)), dim=0)  # (1, input_length)
        # (batch_size, input_length, input_dim)
        tiled_mean = K.permute_dimensions(K.dot(K.expand_dims(mean), ones), (0, 2, 1))
        if mask is not None:
            if K.ndim(mask) > K.ndim(x):
                # Assuming this is because of the bug in Bidirectional. Temporary fix follows.
                # TODO: Fix Bidirectional.
                mask = K.any(mask, axis=(-2, -1))
            if K.ndim(mask) < K.ndim(x):
                mask = K.expand_dims(mask)
            x = switch(mask, x, K.zeros_like(x))
        # (batch_size, input_length, proj_dim)
        projected_combination = K.tanh(K.dot(x, self.vector_projector) + K.dot(tiled_mean, self.mean_projector))
        scores = K.dot(projected_combination, self.scorer)  # (batch_size, input_length)
        weights = K.softmax(scores)  # (batch_size, input_length)
        attended_x = K.sum(K.expand_dims(weights) * x, axis=1)  # (batch_size, input_dim)
        return attended_x