77 lines
3.1 KiB
Python
77 lines
3.1 KiB
Python
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import tensorflow as tf
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import logging
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from .base import PolicyBase
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from ..utils import identify_dependent_variables
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class Distributional(PolicyBase):
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"""
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policy class where action is specified by a probability distribution
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"""
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def __init__(self, network_callable, observation_placeholder, has_old_net=False):
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self.observation_placeholder = observation_placeholder
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self.managed_placeholders = {'observation': observation_placeholder}
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self.has_old_net = has_old_net
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network_scope = 'network'
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net_old_scope = 'net_old'
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# build network, action and value
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with tf.variable_scope(network_scope, reuse=tf.AUTO_REUSE):
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action_dist = network_callable()[0]
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assert action_dist is not None
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self.action_dist = action_dist
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self.action = action_dist.sample()
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weights = tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
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self.network_weights = identify_dependent_variables(self.action_dist.log_prob(self.action), weights)
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self._trainable_variables = [var for var in self.network_weights
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if var in tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES)]
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# deal with target network
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if not has_old_net:
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self.sync_weights_ops = None
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else: # then we need to build another tf graph as target network
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with tf.variable_scope('net_old', reuse=tf.AUTO_REUSE):
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self.action_dist_old = network_callable()[0]
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self.action_old = self.action_dist_old.sample()
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old_weights = tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES, scope=net_old_scope)
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# re-filter to rule out some edge cases
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old_weights = [var for var in old_weights if var.name[:len(net_old_scope)] == net_old_scope]
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self.network_old_weights = identify_dependent_variables(self.action_dist_old.log_prob(self.action_old), old_weights)
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assert len(self.network_weights) == len(self.network_old_weights)
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self.sync_weights_ops = [tf.assign(variable_old, variable)
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for (variable_old, variable) in
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zip(self.network_old_weights, self.network_weights)]
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@property
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def trainable_variables(self):
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return set(self._trainable_variables)
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def act(self, observation, my_feed_dict={}):
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sess = tf.get_default_session()
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# observation[None] adds one dimension at the beginning
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feed_dict = {self.observation_placeholder: observation[None]}
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feed_dict.update(my_feed_dict)
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sampled_action = sess.run(self.action, feed_dict=feed_dict)
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sampled_action = sampled_action[0]
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return sampled_action
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def act_test(self, observation, my_feed_dict={}):
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return self.act(observation, my_feed_dict)
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def sync_weights(self):
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"""
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sync the weights of network_old. Direct copy the weights of network.
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:return:
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"""
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if self.sync_weights_ops is not None:
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sess = tf.get_default_session()
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sess.run(self.sync_weights_ops)
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