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coach/agents/policy_gradients_agent.py
Roman Dobosz 1b095aeeca Cleanup imports.
Till now, most of the modules were importing all of the module objects
(variables, classes, functions, other imports) into module namespace,
which potentially could (and was) cause of unintentional use of class or
methods, which was indirect imported.

With this patch, all the star imports were substituted with top-level
module, which provides desired class or function.

Besides, all imports where sorted (where possible) in a way pep8[1]
suggests - first are imports from standard library, than goes third
party imports (like numpy, tensorflow etc) and finally coach modules.
All of those sections are separated by one empty line.

[1] https://www.python.org/dev/peps/pep-0008/#imports
2018-04-13 09:58:40 +02:00

87 lines
4.0 KiB
Python

#
# Copyright (c) 2017 Intel Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import numpy as np
from agents import policy_optimization_agent as poa
import logger
import utils
class PolicyGradientsAgent(poa.PolicyOptimizationAgent):
def __init__(self, env, tuning_parameters, replicated_device=None, thread_id=0):
poa.PolicyOptimizationAgent.__init__(self, env, tuning_parameters, replicated_device, thread_id)
self.returns_mean = utils.Signal('Returns Mean')
self.returns_variance = utils.Signal('Returns Variance')
self.signals.append(self.returns_mean)
self.signals.append(self.returns_variance)
self.last_gradient_update_step_idx = 0
def learn_from_batch(self, batch):
# batch contains a list of episodes to learn from
current_states, next_states, actions, rewards, game_overs, total_returns = self.extract_batch(batch)
for i in reversed(range(len(total_returns))):
if self.policy_gradient_rescaler == poa.PolicyGradientRescaler.TOTAL_RETURN:
total_returns[i] = total_returns[0]
elif self.policy_gradient_rescaler == poa.PolicyGradientRescaler.FUTURE_RETURN:
# just take the total return as it is
pass
elif self.policy_gradient_rescaler == poa.PolicyGradientRescaler.FUTURE_RETURN_NORMALIZED_BY_EPISODE:
# we can get a single transition episode while playing Doom Basic, causing the std to be 0
if self.std_discounted_return != 0:
total_returns[i] = (total_returns[i] - self.mean_discounted_return) / self.std_discounted_return
else:
total_returns[i] = 0
elif self.policy_gradient_rescaler == poa.PolicyGradientRescaler.FUTURE_RETURN_NORMALIZED_BY_TIMESTEP:
total_returns[i] -= self.mean_return_over_multiple_episodes[i]
else:
logger.screen.warning("WARNING: The requested policy gradient rescaler is not available")
targets = total_returns
if not self.env.discrete_controls and len(actions.shape) < 2:
actions = np.expand_dims(actions, -1)
self.returns_mean.add_sample(np.mean(total_returns))
self.returns_variance.add_sample(np.std(total_returns))
result = self.main_network.online_network.accumulate_gradients({**current_states, 'output_0_0': actions}, targets)
total_loss = result[0]
return total_loss
def choose_action(self, curr_state, phase=utils.RunPhase.TRAIN):
# convert to batch so we can run it through the network
if self.env.discrete_controls:
# DISCRETE
action_values = self.main_network.online_network.predict(self.tf_input_state(curr_state)).squeeze()
if phase == utils.RunPhase.TRAIN:
action = self.exploration_policy.get_action(action_values)
else:
action = np.argmax(action_values)
action_value = {"action_probability": action_values[action]}
self.entropy.add_sample(-np.sum(action_values * np.log(action_values + eps)))
else:
# CONTINUOUS
result = self.main_network.online_network.predict(self.tf_input_state(curr_state))
action_values = result[0].squeeze()
if phase == utils.RunPhase.TRAIN:
action = self.exploration_policy.get_action(action_values)
else:
action = action_values
action_value = {}
return action, action_value