import tensorflow as tf
from tensorflow.python.framework import ops
class FlipGradientBuilder(object):
"""
Flips the gradient of the operation.
Copied from tf-dann: https://github.com/pumpikano/tf-dann
"""
def __init__(self):
self.num_calls = 0
def __call__(self, x, l=1.0):
grad_name = "FlipGradient%d" % self.num_calls
@ops.RegisterGradient(grad_name)
def _flip_gradients(op, grad):
return [(-grad) * l]
g = tf.get_default_graph()
with g.gradient_override_map({"Identity": grad_name}):
y = tf.identity(x)
self.num_calls += 1
return y
flip_gradient = FlipGradientBuilder()
