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coach/memories/episodic_experience_replay.py
Itai Caspi a7206ed702 Multiple improvements and bug fixes (#66)
* Multiple improvements and bug fixes:

    * Using lazy stacking to save on memory when using a replay buffer
    * Remove step counting for evaluation episodes
    * Reset game between heatup and training
    * Major bug fixes in NEC (is reproducing the paper results for pong now)
    * Image input rescaling to 0-1 is now optional
    * Change the terminal title to be the experiment name
    * Observation cropping for atari is now optional
    * Added random number of noop actions for gym to match the dqn paper
    * Fixed a bug where the evaluation episodes won't start with the max possible ale lives
    * Added a script for plotting the results of an experiment over all the atari games
2018-02-26 12:29:07 +02:00

177 lines
6.9 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.
#
from memories.memory import *
import threading
from typing import Union
class EpisodicExperienceReplay(Memory):
def __init__(self, tuning_parameters):
"""
:param tuning_parameters: A Preset class instance with all the running paramaters
:type tuning_parameters: Preset
"""
Memory.__init__(self, tuning_parameters)
self.tp = tuning_parameters
self.max_size_in_episodes = tuning_parameters.agent.num_episodes_in_experience_replay
self.max_size_in_transitions = tuning_parameters.agent.num_transitions_in_experience_replay
self.discount = tuning_parameters.agent.discount
self.buffer = [Episode()] # list of episodes
self.transitions = []
self._length = 1
self._num_transitions = 0
self._num_transitions_in_complete_episodes = 0
self.return_is_bootstrapped = tuning_parameters.agent.bootstrap_total_return_from_old_policy
def length(self):
""" Get the number of episodes in the ER (even if they are not complete) """
if self._length is not 0 and self.buffer[-1].is_empty():
return self._length - 1
return self._length
def num_complete_episodes(self):
""" Get the number of complete episodes in ER """
return self._length - 1
def num_transitions(self):
return self._num_transitions
def num_transitions_in_complete_episodes(self):
return self._num_transitions_in_complete_episodes
def sample_episode(self):
episode_idx = np.random.randint(self.num_complete_episodes())
return self.buffer[episode_idx]
def sample_n_episodes(self, n):
num_n_episodes = (self.num_complete_episodes()) / n
assert num_n_episodes > 0, \
'Tried sampling {} episodes when only {} completed episodes are available in the memory' \
.format(n, self.num_complete_episodes())
start_episode_idx = np.random.randint(num_n_episodes) * n
return self.buffer[start_episode_idx:(start_episode_idx + n)]
def sample_last_n_episodes(self, n):
num_n_episodes = (self.num_complete_episodes()) / n
assert num_n_episodes > 0, \
'Tried sampling {} episodes when only {} completed episodes are available in the memory' \
.format(n, self.num_complete_episodes())
start_episode_idx = -n
return self.buffer[start_episode_idx:(start_episode_idx + n)]
def sample(self, size):
assert self.num_transitions_in_complete_episodes() > size, \
'There are not enough transitions in the replay buffer. ' \
'Available transitions: {}. Requested transitions: {}.'\
.format(self.num_transitions_in_complete_episodes(), size)
batch = []
transitions_idx = np.random.randint(self.num_transitions_in_complete_episodes(), size=size)
for i in transitions_idx:
batch.append(self.transitions[i])
return batch
def enforce_length(self):
# clean up if necessary
if self.max_size_in_transitions is not None:
while self.max_size_in_transitions != 0 and self.num_transitions() > self.max_size_in_transitions:
self.remove_episode(0)
else:
while self.length() > self.max_size_in_episodes:
self.remove_episode(0)
def store(self, transition):
if len(self.buffer) == 0:
self.buffer.append(Episode())
last_episode = self.buffer[-1]
last_episode.insert(transition)
self.transitions.append(transition)
self._num_transitions += 1
if transition.game_over:
self._num_transitions_in_complete_episodes += last_episode.length()
self._length += 1
self.buffer[-1].update_returns(self.discount,
is_bootstrapped=self.tp.agent.bootstrap_total_return_from_old_policy,
n_step_return=self.tp.agent.n_step)
self.buffer[-1].update_measurements_targets(self.tp.agent.num_predicted_steps_ahead)
# self.buffer[-1].update_actions_probabilities() # used for off-policy policy optimization
self.buffer.append(Episode())
self.enforce_length()
def insert_full_episode(self, episode):
# Do not add a new episode if the last one is not closed yet
if self.buffer[-1].get_last_transition().done != True:
return False
episode.update_returns(self.discount)
episode.update_measurements_targets(self.tp.agent.num_predicted_steps_ahead)
self.buffer.append(episode)
self.transitions += episode.transitions
self._length += 1
self._num_transitions += episode.length()
self.enforce_length()
return True
def get_episode(self, episode_index):
if self.length() == 0:
return None
episode = self.buffer[episode_index]
return episode
def remove_episode(self, episode_index):
if len(self.buffer) > episode_index:
episode_length = self.buffer[episode_index].length()
self._length -= 1
self._num_transitions -= episode_length
self._num_transitions_in_complete_episodes -= episode_length
del self.transitions[:episode_length]
del self.buffer[episode_index]
# for API compatibility
def get(self, index):
return self.get_episode(index)
def get_last_complete_episode(self) -> Union[None, Episode]:
"""
Returns the last complete episode in the memory or None if there are no complete episodes
:return: None or the last complete episode
"""
last_complete_episode_index = self.num_complete_episodes()-1
if last_complete_episode_index >= 0:
return self.get(last_complete_episode_index)
else:
return None
def update_last_transition_info(self, info):
episode = self.buffer[-1]
if episode.length() == 0:
if len(self.buffer) < 2:
return
episode = self.buffer[-2]
for key, val in info.items():
episode.transitions[-1].info[key] = val
def clean(self):
self.transitions = []
self.buffer = [Episode()]
self._length = 1
self._num_transitions = 0
self._num_transitions_in_complete_episodes = 0