Files
ray/examples/policy_gradient/reinforce/policy.py
T
Eric LiangandPhilipp Moritz 4374ad1453 Policy gradient example: Support multi-GPU training (#584)
* add tf metrics

* comments

* fix network scopes

* add doc

* initial work

* try with 3 virtual cpus

* clean up metrics

* use format string

* fix trace level

* back to pong

* always run summary on cpu

* plot intermediate and final sgd stats

* add back a global step

* update

* add timeline

* use staging area and reuse weights properly

* stage at cpu

* whoops, stage only the batch

* clean up a bit

* fix py flake

* wip

* create an optimizer graph per device

* print timeline on 5th batch instead

* print examples per second

* log placement for training ops

* force placement on cpu:0

* try separating weights onto different gpus

* try using nccl

* add cpu fallback

* remove space from date

* check has gpu device

* fix flag config

* checkpoint

* wip

* update

* add some timing

* trace loading

* try cpu

* revert that

* remove expensive test

* lint

* cleanups

* clean up timers

* clean it up a bit

* fix code for non-scalar action spaces

* address some nits

* fix quotes

* efficient shuffling between sgd epochs
2017-06-13 06:03:25 +00:00

53 lines
2.0 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import gym.spaces
import tensorflow as tf
from reinforce.models.visionnet import vision_net
from reinforce.models.fcnet import fc_net
class ProximalPolicyLoss(object):
def __init__(
self, observation_space, action_space,
observations, advantages, actions, prev_logits, logit_dim,
kl_coeff, distribution_class, config, sess):
assert (isinstance(action_space, gym.spaces.Discrete) or
isinstance(action_space, gym.spaces.Box))
self.prev_dist = distribution_class(prev_logits)
# Saved so that we can compute actions given different observations
self.observations = observations
if len(observation_space.shape) > 1:
self.curr_logits = vision_net(observations, num_classes=logit_dim)
else:
assert len(observation_space.shape) == 1
self.curr_logits = fc_net(observations, num_classes=logit_dim)
self.curr_dist = distribution_class(self.curr_logits)
self.sampler = self.curr_dist.sample()
# Make loss functions.
self.ratio = tf.exp(self.curr_dist.logp(actions) -
self.prev_dist.logp(actions))
self.kl = self.prev_dist.kl(self.curr_dist)
self.mean_kl = tf.reduce_mean(self.kl)
self.entropy = self.curr_dist.entropy()
self.mean_entropy = tf.reduce_mean(self.entropy)
self.surr1 = self.ratio * advantages
self.surr2 = tf.clip_by_value(self.ratio, 1 - config["clip_param"],
1 + config["clip_param"]) * advantages
self.surr = tf.minimum(self.surr1, self.surr2)
self.loss = tf.reduce_mean(-self.surr + kl_coeff * self.kl -
config["entropy_coeff"] * self.entropy)
self.sess = sess
def compute_actions(self, observations):
return self.sess.run([self.sampler, self.curr_logits],
feed_dict={self.observations: observations})
def loss(self):
return self.loss