Files
ray/examples/policy_gradient/reinforce/policy.py
T
Robert NishiharaandAlexey Tumanov 3ebfd850e1 Make example applications pep8 compliant. (#553)
* Test examples for pep8 compliance.

* Make rl_pong example pep8 compliant.

* Make policy gradient example pep8 compliant.

* Make lbfgs example pep8 compliant.

* Make hyperopt example pep8 compliant.

* Make a3c example pep8 compliant.

* Make evolution strategies example pep8 compliant.

* Make resnet example pep8 compliant.

* Fix.
2017-05-16 14:12:18 -07:00

71 lines
3.0 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
from reinforce.distributions import Categorical, DiagGaussian
class ProximalPolicyLoss(object):
def __init__(self, observation_space, action_space, preprocessor, config,
sess):
assert (isinstance(action_space, gym.spaces.Discrete) or
isinstance(action_space, gym.spaces.Box))
# Adapting the kl divergence.
self.kl_coeff = tf.placeholder(name="newkl", shape=(), dtype=tf.float32)
self.observations = tf.placeholder(tf.float32,
shape=(None,) + preprocessor.shape)
self.advantages = tf.placeholder(tf.float32, shape=(None,))
if isinstance(action_space, gym.spaces.Box):
# The first half of the dimensions are the means, the second half are the
# standard deviations.
self.action_dim = action_space.shape[0]
self.logit_dim = 2 * self.action_dim
self.actions = tf.placeholder(tf.float32,
shape=(None, action_space.shape[0]))
Distribution = DiagGaussian
elif isinstance(action_space, gym.spaces.Discrete):
self.action_dim = action_space.n
self.logit_dim = self.action_dim
self.actions = tf.placeholder(tf.int64, shape=(None,))
Distribution = Categorical
else:
raise NotImplemented("action space" + str(type(action_space)) +
"currently not supported")
self.prev_logits = tf.placeholder(tf.float32, shape=(None, self.logit_dim))
self.prev_dist = Distribution(self.prev_logits)
if len(observation_space.shape) > 1:
self.curr_logits = vision_net(self.observations,
num_classes=self.logit_dim)
else:
assert len(observation_space.shape) == 1
self.curr_logits = fc_net(self.observations, num_classes=self.logit_dim)
self.curr_dist = Distribution(self.curr_logits)
self.sampler = self.curr_dist.sample()
self.entropy = self.curr_dist.entropy()
# Make loss functions.
self.ratio = tf.exp(self.curr_dist.logp(self.actions) -
self.prev_dist.logp(self.actions))
self.kl = self.prev_dist.kl(self.curr_dist)
self.mean_kl = tf.reduce_mean(self.kl)
self.mean_entropy = tf.reduce_mean(self.entropy)
self.surr1 = self.ratio * self.advantages
self.surr2 = tf.clip_by_value(self.ratio, 1 - config["clip_param"],
1 + config["clip_param"]) * self.advantages
self.surr = tf.minimum(self.surr1, self.surr2)
self.loss = tf.reduce_mean(-self.surr + self.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