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coach/agents/ppo_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

298 lines
14 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 collections
import copy
import numpy as np
from agents import actor_critic_agent as aca
from agents import policy_optimization_agent as poa
from architectures import network_wrapper as nw
import configurations
import logger
import utils
# Proximal Policy Optimization - https://arxiv.org/pdf/1707.06347.pdf
class PPOAgent(aca.ActorCriticAgent):
def __init__(self, env, tuning_parameters, replicated_device=None, thread_id=0):
aca.ActorCriticAgent.__init__(self, env, tuning_parameters, replicated_device, thread_id,
create_target_network=True)
self.critic_network = self.main_network
# define the policy network
tuning_parameters.agent.input_types = {'observation': configurations.InputTypes.Observation}
tuning_parameters.agent.output_types = [configurations.OutputTypes.PPO]
tuning_parameters.agent.optimizer_type = 'Adam'
tuning_parameters.agent.l2_regularization = 0
self.policy_network = nw.NetworkWrapper(tuning_parameters, True, self.has_global, 'policy',
self.replicated_device, self.worker_device)
self.networks.append(self.policy_network)
# signals definition
self.value_loss = utils.Signal('Value Loss')
self.signals.append(self.value_loss)
self.policy_loss = utils.Signal('Policy Loss')
self.signals.append(self.policy_loss)
self.kl_divergence = utils.Signal('KL Divergence')
self.signals.append(self.kl_divergence)
self.total_kl_divergence_during_training_process = 0.0
self.unclipped_grads = utils.Signal('Grads (unclipped)')
self.signals.append(self.unclipped_grads)
self.reset_game(do_not_reset_env=True)
def fill_advantages(self, batch):
current_states, next_states, actions, rewards, game_overs, total_return = self.extract_batch(batch)
# * Found not to have any impact *
# current_states_with_timestep = self.concat_state_and_timestep(batch)
current_state_values = self.critic_network.online_network.predict(current_states).squeeze()
# calculate advantages
advantages = []
if self.policy_gradient_rescaler == poa.PolicyGradientRescaler.A_VALUE:
advantages = total_return - current_state_values
elif self.policy_gradient_rescaler == poa.PolicyGradientRescaler.GAE:
# get bootstraps
episode_start_idx = 0
advantages = np.array([])
# current_state_values[game_overs] = 0
for idx, game_over in enumerate(game_overs):
if game_over:
# get advantages for the rollout
value_bootstrapping = np.zeros((1,))
rollout_state_values = np.append(current_state_values[episode_start_idx:idx+1], value_bootstrapping)
rollout_advantages, _ = \
self.get_general_advantage_estimation_values(rewards[episode_start_idx:idx+1],
rollout_state_values)
episode_start_idx = idx + 1
advantages = np.append(advantages, rollout_advantages)
else:
logger.screen.warning("WARNING: The requested policy gradient rescaler is not available")
# standardize
advantages = (advantages - np.mean(advantages)) / np.std(advantages)
for transition, advantage in zip(self.memory.transitions, advantages):
transition.info['advantage'] = advantage
self.action_advantages.add_sample(advantages)
def train_value_network(self, dataset, epochs):
loss = []
current_states, _, _, _, _, total_return = self.extract_batch(dataset)
# * Found not to have any impact *
# add a timestep to the observation
# current_states_with_timestep = self.concat_state_and_timestep(dataset)
total_return = np.expand_dims(total_return, -1)
mix_fraction = self.tp.agent.value_targets_mix_fraction
for j in range(epochs):
batch_size = len(dataset)
if self.critic_network.online_network.optimizer_type != 'LBFGS':
batch_size = self.tp.batch_size
for i in range(len(dataset) // batch_size):
# split to batches for first order optimization techniques
current_states_batch = {
k: v[i * batch_size:(i + 1) * batch_size]
for k, v in current_states.items()
}
total_return_batch = total_return[i * batch_size:(i + 1) * batch_size]
old_policy_values = utils.force_list(self.critic_network.target_network.predict(
current_states_batch).squeeze())
if self.critic_network.online_network.optimizer_type != 'LBFGS':
targets = total_return_batch
else:
current_values = self.critic_network.online_network.predict(current_states_batch)
targets = current_values * (1 - mix_fraction) + total_return_batch * mix_fraction
inputs = copy.copy(current_states_batch)
for input_index, input in enumerate(old_policy_values):
name = 'output_0_{}'.format(input_index)
if name in self.critic_network.online_network.inputs:
inputs[name] = input
value_loss = self.critic_network.online_network.accumulate_gradients(inputs, targets)
self.critic_network.apply_gradients_to_online_network()
if self.tp.distributed:
self.critic_network.apply_gradients_to_global_network()
self.critic_network.online_network.reset_accumulated_gradients()
loss.append([value_loss[0]])
loss = np.mean(loss, 0)
return loss
def concat_state_and_timestep(self, dataset):
current_states_with_timestep = [np.append(transition.state['observation'], transition.info['timestep'])
for transition in dataset]
current_states_with_timestep = np.expand_dims(current_states_with_timestep, -1)
return current_states_with_timestep
def train_policy_network(self, dataset, epochs):
loss = []
for j in range(epochs):
loss = {
'total_loss': [],
'policy_losses': [],
'unclipped_grads': [],
'fetch_result': []
}
#shuffle(dataset)
for i in range(len(dataset) // self.tp.batch_size):
batch = dataset[i * self.tp.batch_size:(i + 1) * self.tp.batch_size]
current_states, _, actions, _, _, total_return = self.extract_batch(batch)
advantages = np.array([t.info['advantage'] for t in batch])
if not self.tp.env_instance.discrete_controls and len(actions.shape) == 1:
actions = np.expand_dims(actions, -1)
# get old policy probabilities and distribution
old_policy = utils.force_list(self.policy_network.target_network.predict(current_states))
# calculate gradients and apply on both the local policy network and on the global policy network
fetches = [self.policy_network.online_network.output_heads[0].kl_divergence,
self.policy_network.online_network.output_heads[0].entropy]
inputs = copy.copy(current_states)
# TODO: why is this output 0 and not output 1?
inputs['output_0_0'] = actions
# TODO: does old_policy_distribution really need to be represented as a list?
# A: yes it does, in the event of discrete controls, it has just a mean
# otherwise, it has both a mean and standard deviation
for input_index, input in enumerate(old_policy):
inputs['output_0_{}'.format(input_index + 1)] = input
total_loss, policy_losses, unclipped_grads, fetch_result =\
self.policy_network.online_network.accumulate_gradients(
inputs, [advantages], additional_fetches=fetches)
self.policy_network.apply_gradients_to_online_network()
if self.tp.distributed:
self.policy_network.apply_gradients_to_global_network()
self.policy_network.online_network.reset_accumulated_gradients()
loss['total_loss'].append(total_loss)
loss['policy_losses'].append(policy_losses)
loss['unclipped_grads'].append(unclipped_grads)
loss['fetch_result'].append(fetch_result)
self.unclipped_grads.add_sample(unclipped_grads)
for key in loss.keys():
loss[key] = np.mean(loss[key], 0)
if self.tp.learning_rate_decay_rate != 0:
curr_learning_rate = self.main_network.online_network.get_variable_value(self.tp.learning_rate)
self.curr_learning_rate.add_sample(curr_learning_rate)
else:
curr_learning_rate = self.tp.learning_rate
# log training parameters
logger.screen.log_dict(
collections.OrderedDict([
("Surrogate loss", loss['policy_losses'][0]),
("KL divergence", loss['fetch_result'][0]),
("Entropy", loss['fetch_result'][1]),
("training epoch", j),
("learning_rate", curr_learning_rate)
]),
prefix="Policy training"
)
self.total_kl_divergence_during_training_process = loss['fetch_result'][0]
self.entropy.add_sample(loss['fetch_result'][1])
self.kl_divergence.add_sample(loss['fetch_result'][0])
return loss['total_loss']
def update_kl_coefficient(self):
# John Schulman takes the mean kl divergence only over the last epoch which is strange but we will follow
# his implementation for now because we know it works well
logger.screen.log_title("KL = {}".format(self.total_kl_divergence_during_training_process))
# update kl coefficient
kl_target = self.tp.agent.target_kl_divergence
kl_coefficient = self.policy_network.online_network.get_variable_value(
self.policy_network.online_network.output_heads[0].kl_coefficient)
new_kl_coefficient = kl_coefficient
if self.total_kl_divergence_during_training_process > 1.3 * kl_target:
# kl too high => increase regularization
new_kl_coefficient *= 1.5
elif self.total_kl_divergence_during_training_process < 0.7 * kl_target:
# kl too low => decrease regularization
new_kl_coefficient /= 1.5
# update the kl coefficient variable
if kl_coefficient != new_kl_coefficient:
self.policy_network.online_network.set_variable_value(
self.policy_network.online_network.output_heads[0].assign_kl_coefficient,
new_kl_coefficient,
self.policy_network.online_network.output_heads[0].kl_coefficient_ph)
logger.screen.log_title("KL penalty coefficient change = {} -> {}".format(kl_coefficient, new_kl_coefficient))
def post_training_commands(self):
if self.tp.agent.use_kl_regularization:
self.update_kl_coefficient()
# clean memory
self.memory.clean()
def train(self):
self.policy_network.sync()
self.critic_network.sync()
dataset = self.memory.transitions
self.fill_advantages(dataset)
# take only the requested number of steps
dataset = dataset[:self.tp.agent.num_consecutive_playing_steps]
value_loss = self.train_value_network(dataset, 1)
policy_loss = self.train_policy_network(dataset, 10)
self.value_loss.add_sample(value_loss)
self.policy_loss.add_sample(policy_loss)
self.update_log() # should be done in order to update the data that has been accumulated * while not playing *
return np.append(value_loss, policy_loss)
def choose_action(self, curr_state, phase=utils.RunPhase.TRAIN):
if self.env.discrete_controls:
# DISCRETE
action_values = self.policy_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_info = {"action_probability": action_values[action]}
# self.entropy.add_sample(-np.sum(action_values * np.log(action_values)))
else:
# CONTINUOUS
action_values_mean, action_values_std = self.policy_network.online_network.predict(self.tf_input_state(curr_state))
action_values_mean = action_values_mean.squeeze()
action_values_std = action_values_std.squeeze()
if phase == utils.RunPhase.TRAIN:
action = np.squeeze(np.random.randn(1, self.action_space_size) * action_values_std + action_values_mean)
else:
action = action_values_mean
action_info = {"action_probability": action_values_mean}
return action, action_info