layers.py 文件源码

def __call__(self, x, gamma=1.0):
        grad_name = "GradientReverse%d" % self.num_calls

        @ops.RegisterGradient(grad_name)
        def _gradients_reverse(op, grad):
            return [tf.neg(grad) * gamma]

        g = tf.get_default_graph()
        with g.gradient_override_map({"Identity": grad_name}):
            y = tf.identity(x)

        self.num_calls += 1
        return y