43 lines
1.4 KiB
Python

import tensorflow as tf
def identify_dependent_variables(tensor, candidate_variables):
"""
identify the variables that `tensor` depends on
:param tensor: A Tensor.
:param candidate_variables: A list of Variables.
:return: A list of variables in `candidate variables` that has effect on `tensor`
"""
grads = tf.gradients(tensor, candidate_variables)
return [var for var, grad in zip(candidate_variables, grads) if grad is not None]
def get_soft_update_op(update_fraction, including_nets, excluding_nets=None):
"""
:param including_nets:
:param excluding_nets:
:return:
"""
assert 0 < update_fraction < 1, 'Unrecommended update_fraction <=0 or >=1!'
variables = []
variables_old = []
for net in including_nets:
for var, var_old in zip(net.network_weights, net.network_old_weights):
if var not in variables:
variables.append(var)
variables_old.append(var_old)
if excluding_nets:
excluding_variables = []
for net in excluding_nets:
excluding_variables += net.network_weights
for var, var_old in zip(variables, variables_old):
if var in excluding_variables:
variables.remove(var)
variables_old.remove(var_old)
return [tf.assign(var_old, update_fraction * var + (1 - update_fraction) * var_old)
for var_old, var in zip(variables_old, variables)]