from functools import partial
import tensorflow as tf
import numpy as np
import gym
from stable_baselines import logger, deepq
from stable_baselines.common import tf_util, OffPolicyRLModel, SetVerbosity, TensorboardWriter
from stable_baselines.common.vec_env import VecEnv
from stable_baselines.common.schedules import LinearSchedule
from stable_baselines.deepq.replay_buffer import ReplayBuffer, PrioritizedReplayBuffer
from stable_baselines.deepq.policies import DQNPolicy
from stable_baselines.a2c.utils import total_episode_reward_logger
[docs]class DQN(OffPolicyRLModel):
"""
The DQN model class.
DQN paper: https://arxiv.org/abs/1312.5602
Dueling DQN: https://arxiv.org/abs/1511.06581
Double-Q Learning: https://arxiv.org/abs/1509.06461
Prioritized Experience Replay: https://arxiv.org/abs/1511.05952
:param policy: (DQNPolicy or str) The policy model to use (MlpPolicy, CnnPolicy, LnMlpPolicy, ...)
:param env: (Gym environment or str) The environment to learn from (if registered in Gym, can be str)
:param gamma: (float) discount factor
:param learning_rate: (float) learning rate for adam optimizer
:param buffer_size: (int) size of the replay buffer
:param exploration_fraction: (float) fraction of entire training period over which the exploration rate is
annealed
:param exploration_final_eps: (float) final value of random action probability
:param train_freq: (int) update the model every `train_freq` steps. set to None to disable printing
:param batch_size: (int) size of a batched sampled from replay buffer for training
:param double_q: (bool) Whether to enable Double-Q learning or not.
:param learning_starts: (int) how many steps of the model to collect transitions for before learning starts
:param target_network_update_freq: (int) update the target network every `target_network_update_freq` steps.
:param prioritized_replay: (bool) if True prioritized replay buffer will be used.
:param prioritized_replay_alpha: (float)alpha parameter for prioritized replay buffer.
It determines how much prioritization is used, with alpha=0 corresponding to the uniform case.
:param prioritized_replay_beta0: (float) initial value of beta for prioritized replay buffer
:param prioritized_replay_beta_iters: (int) number of iterations over which beta will be annealed from initial
value to 1.0. If set to None equals to max_timesteps.
:param prioritized_replay_eps: (float) epsilon to add to the TD errors when updating priorities.
:param param_noise: (bool) Whether or not to apply noise to the parameters of the policy.
:param verbose: (int) the verbosity level: 0 none, 1 training information, 2 tensorflow debug
:param tensorboard_log: (str) the log location for tensorboard (if None, no logging)
:param _init_setup_model: (bool) Whether or not to build the network at the creation of the instance
:param full_tensorboard_log: (bool) enable additional logging when using tensorboard
WARNING: this logging can take a lot of space quickly
"""
def __init__(self, policy, env, gamma=0.99, learning_rate=5e-4, buffer_size=50000, exploration_fraction=0.1,
exploration_final_eps=0.02, train_freq=1, batch_size=32, double_q=True,
learning_starts=1000, target_network_update_freq=500, prioritized_replay=False,
prioritized_replay_alpha=0.6, prioritized_replay_beta0=0.4, prioritized_replay_beta_iters=None,
prioritized_replay_eps=1e-6, param_noise=False, verbose=0, tensorboard_log=None,
_init_setup_model=True, policy_kwargs=None, full_tensorboard_log=False):
# TODO: replay_buffer refactoring
super(DQN, self).__init__(policy=policy, env=env, replay_buffer=None, verbose=verbose, policy_base=DQNPolicy,
requires_vec_env=False, policy_kwargs=policy_kwargs)
self.param_noise = param_noise
self.learning_starts = learning_starts
self.train_freq = train_freq
self.prioritized_replay = prioritized_replay
self.prioritized_replay_eps = prioritized_replay_eps
self.batch_size = batch_size
self.target_network_update_freq = target_network_update_freq
self.prioritized_replay_alpha = prioritized_replay_alpha
self.prioritized_replay_beta0 = prioritized_replay_beta0
self.prioritized_replay_beta_iters = prioritized_replay_beta_iters
self.exploration_final_eps = exploration_final_eps
self.exploration_fraction = exploration_fraction
self.buffer_size = buffer_size
self.learning_rate = learning_rate
self.gamma = gamma
self.tensorboard_log = tensorboard_log
self.full_tensorboard_log = full_tensorboard_log
self.double_q = double_q
self.graph = None
self.sess = None
self._train_step = None
self.step_model = None
self.update_target = None
self.act = None
self.proba_step = None
self.replay_buffer = None
self.beta_schedule = None
self.exploration = None
self.params = None
self.summary = None
self.episode_reward = None
if _init_setup_model:
self.setup_model()
def _get_pretrain_placeholders(self):
policy = self.step_model
return policy.obs_ph, tf.placeholder(tf.int32, [None]), policy.q_values
[docs] def setup_model(self):
with SetVerbosity(self.verbose):
assert not isinstance(self.action_space, gym.spaces.Box), \
"Error: DQN cannot output a gym.spaces.Box action space."
# If the policy is wrap in functool.partial (e.g. to disable dueling)
# unwrap it to check the class type
if isinstance(self.policy, partial):
test_policy = self.policy.func
else:
test_policy = self.policy
assert issubclass(test_policy, DQNPolicy), "Error: the input policy for the DQN model must be " \
"an instance of DQNPolicy."
self.graph = tf.Graph()
with self.graph.as_default():
self.sess = tf_util.make_session(graph=self.graph)
optimizer = tf.train.AdamOptimizer(learning_rate=self.learning_rate)
self.act, self._train_step, self.update_target, self.step_model = deepq.build_train(
q_func=partial(self.policy, **self.policy_kwargs),
ob_space=self.observation_space,
ac_space=self.action_space,
optimizer=optimizer,
gamma=self.gamma,
grad_norm_clipping=10,
param_noise=self.param_noise,
sess=self.sess,
full_tensorboard_log=self.full_tensorboard_log,
double_q=self.double_q
)
self.proba_step = self.step_model.proba_step
self.params = tf_util.get_trainable_vars("deepq")
# Initialize the parameters and copy them to the target network.
tf_util.initialize(self.sess)
self.update_target(sess=self.sess)
self.summary = tf.summary.merge_all()
[docs] def learn(self, total_timesteps, callback=None, seed=None, log_interval=100, tb_log_name="DQN",
reset_num_timesteps=True, replay_wrapper=None):
new_tb_log = self._init_num_timesteps(reset_num_timesteps)
with SetVerbosity(self.verbose), TensorboardWriter(self.graph, self.tensorboard_log, tb_log_name, new_tb_log) \
as writer:
self._setup_learn(seed)
# Create the replay buffer
if self.prioritized_replay:
self.replay_buffer = PrioritizedReplayBuffer(self.buffer_size, alpha=self.prioritized_replay_alpha)
if self.prioritized_replay_beta_iters is None:
prioritized_replay_beta_iters = total_timesteps
else:
prioritized_replay_beta_iters = self.prioritized_replay_beta_iters
self.beta_schedule = LinearSchedule(prioritized_replay_beta_iters,
initial_p=self.prioritized_replay_beta0,
final_p=1.0)
else:
self.replay_buffer = ReplayBuffer(self.buffer_size)
self.beta_schedule = None
if replay_wrapper is not None:
assert not self.prioritized_replay, "Prioritized replay buffer is not supported by HER"
self.replay_buffer = replay_wrapper(self.replay_buffer)
# Create the schedule for exploration starting from 1.
self.exploration = LinearSchedule(schedule_timesteps=int(self.exploration_fraction * total_timesteps),
initial_p=1.0,
final_p=self.exploration_final_eps)
episode_rewards = [0.0]
episode_successes = []
obs = self.env.reset()
reset = True
self.episode_reward = np.zeros((1,))
for _ in range(total_timesteps):
if callback is not None:
# Only stop training if return value is False, not when it is None. This is for backwards
# compatibility with callbacks that have no return statement.
if callback(locals(), globals()) is False:
break
# Take action and update exploration to the newest value
kwargs = {}
if not self.param_noise:
update_eps = self.exploration.value(self.num_timesteps)
update_param_noise_threshold = 0.
else:
update_eps = 0.
# Compute the threshold such that the KL divergence between perturbed and non-perturbed
# policy is comparable to eps-greedy exploration with eps = exploration.value(t).
# See Appendix C.1 in Parameter Space Noise for Exploration, Plappert et al., 2017
# for detailed explanation.
update_param_noise_threshold = \
-np.log(1. - self.exploration.value(self.num_timesteps) +
self.exploration.value(self.num_timesteps) / float(self.env.action_space.n))
kwargs['reset'] = reset
kwargs['update_param_noise_threshold'] = update_param_noise_threshold
kwargs['update_param_noise_scale'] = True
with self.sess.as_default():
action = self.act(np.array(obs)[None], update_eps=update_eps, **kwargs)[0]
env_action = action
reset = False
new_obs, rew, done, info = self.env.step(env_action)
# Store transition in the replay buffer.
self.replay_buffer.add(obs, action, rew, new_obs, float(done))
obs = new_obs
if writer is not None:
ep_rew = np.array([rew]).reshape((1, -1))
ep_done = np.array([done]).reshape((1, -1))
self.episode_reward = total_episode_reward_logger(self.episode_reward, ep_rew, ep_done, writer,
self.num_timesteps)
episode_rewards[-1] += rew
if done:
maybe_is_success = info.get('is_success')
if maybe_is_success is not None:
episode_successes.append(float(maybe_is_success))
if not isinstance(self.env, VecEnv):
obs = self.env.reset()
episode_rewards.append(0.0)
reset = True
# Do not train if the warmup phase is not over
# or if there are not enough samples in the replay buffer
can_sample = self.replay_buffer.can_sample(self.batch_size)
if can_sample and self.num_timesteps > self.learning_starts \
and self.num_timesteps % self.train_freq == 0:
# Minimize the error in Bellman's equation on a batch sampled from replay buffer.
if self.prioritized_replay:
experience = self.replay_buffer.sample(self.batch_size,
beta=self.beta_schedule.value(self.num_timesteps))
(obses_t, actions, rewards, obses_tp1, dones, weights, batch_idxes) = experience
else:
obses_t, actions, rewards, obses_tp1, dones = self.replay_buffer.sample(self.batch_size)
weights, batch_idxes = np.ones_like(rewards), None
if writer is not None:
# run loss backprop with summary, but once every 100 steps save the metadata
# (memory, compute time, ...)
if (1 + self.num_timesteps) % 100 == 0:
run_options = tf.RunOptions(trace_level=tf.RunOptions.FULL_TRACE)
run_metadata = tf.RunMetadata()
summary, td_errors = self._train_step(obses_t, actions, rewards, obses_tp1, obses_tp1,
dones, weights, sess=self.sess, options=run_options,
run_metadata=run_metadata)
writer.add_run_metadata(run_metadata, 'step%d' % self.num_timesteps)
else:
summary, td_errors = self._train_step(obses_t, actions, rewards, obses_tp1, obses_tp1,
dones, weights, sess=self.sess)
writer.add_summary(summary, self.num_timesteps)
else:
_, td_errors = self._train_step(obses_t, actions, rewards, obses_tp1, obses_tp1, dones, weights,
sess=self.sess)
if self.prioritized_replay:
new_priorities = np.abs(td_errors) + self.prioritized_replay_eps
self.replay_buffer.update_priorities(batch_idxes, new_priorities)
if can_sample and self.num_timesteps > self.learning_starts and \
self.num_timesteps % self.target_network_update_freq == 0:
# Update target network periodically.
self.update_target(sess=self.sess)
if len(episode_rewards[-101:-1]) == 0:
mean_100ep_reward = -np.inf
else:
mean_100ep_reward = round(float(np.mean(episode_rewards[-101:-1])), 1)
num_episodes = len(episode_rewards)
if self.verbose >= 1 and done and log_interval is not None and len(episode_rewards) % log_interval == 0:
logger.record_tabular("steps", self.num_timesteps)
logger.record_tabular("episodes", num_episodes)
if len(episode_successes) > 0:
logger.logkv("success rate", np.mean(episode_successes[-100:]))
logger.record_tabular("mean 100 episode reward", mean_100ep_reward)
logger.record_tabular("% time spent exploring",
int(100 * self.exploration.value(self.num_timesteps)))
logger.dump_tabular()
self.num_timesteps += 1
return self
[docs] def predict(self, observation, state=None, mask=None, deterministic=True):
observation = np.array(observation)
vectorized_env = self._is_vectorized_observation(observation, self.observation_space)
observation = observation.reshape((-1,) + self.observation_space.shape)
with self.sess.as_default():
actions, _, _ = self.step_model.step(observation, deterministic=deterministic)
if not vectorized_env:
actions = actions[0]
return actions, None
[docs] def action_probability(self, observation, state=None, mask=None, actions=None, logp=False):
observation = np.array(observation)
vectorized_env = self._is_vectorized_observation(observation, self.observation_space)
observation = observation.reshape((-1,) + self.observation_space.shape)
actions_proba = self.proba_step(observation, state, mask)
if actions is not None: # comparing the action distribution, to given actions
actions = np.array([actions])
assert isinstance(self.action_space, gym.spaces.Discrete)
actions = actions.reshape((-1,))
assert observation.shape[0] == actions.shape[0], "Error: batch sizes differ for actions and observations."
actions_proba = actions_proba[np.arange(actions.shape[0]), actions]
# normalize action proba shape
actions_proba = actions_proba.reshape((-1, 1))
if logp:
actions_proba = np.log(actions_proba)
if not vectorized_env:
if state is not None:
raise ValueError("Error: The environment must be vectorized when using recurrent policies.")
actions_proba = actions_proba[0]
return actions_proba
[docs] def get_parameter_list(self):
return self.params
[docs] def save(self, save_path, cloudpickle=False):
# params
data = {
"double_q": self.double_q,
"param_noise": self.param_noise,
"learning_starts": self.learning_starts,
"train_freq": self.train_freq,
"prioritized_replay": self.prioritized_replay,
"prioritized_replay_eps": self.prioritized_replay_eps,
"batch_size": self.batch_size,
"target_network_update_freq": self.target_network_update_freq,
"prioritized_replay_alpha": self.prioritized_replay_alpha,
"prioritized_replay_beta0": self.prioritized_replay_beta0,
"prioritized_replay_beta_iters": self.prioritized_replay_beta_iters,
"exploration_final_eps": self.exploration_final_eps,
"exploration_fraction": self.exploration_fraction,
"learning_rate": self.learning_rate,
"gamma": self.gamma,
"verbose": self.verbose,
"observation_space": self.observation_space,
"action_space": self.action_space,
"policy": self.policy,
"n_envs": self.n_envs,
"_vectorize_action": self._vectorize_action,
"policy_kwargs": self.policy_kwargs
}
params_to_save = self.get_parameters()
self._save_to_file(save_path, data=data, params=params_to_save, cloudpickle=cloudpickle)