stable-baselines3/stable_baselines3/common/off_policy_algorithm.py
Tirafesi 644d2c17ac
save_replay_buffer now receives as argument the file path instead of the folder path (#63)
* save_replay_buffer now receives as argument the file path instead of the folder path

* Update changelog.rst

Co-authored-by: Antonin RAFFIN <antonin.raffin@ensta.org>
2020-06-17 14:00:49 +02:00

279 lines
14 KiB
Python

import time
import os
import pickle
import warnings
from typing import Union, Type, Optional, Dict, Any, Callable
import gym
import torch as th
import numpy as np
from stable_baselines3.common import logger
from stable_baselines3.common.base_class import BaseAlgorithm
from stable_baselines3.common.policies import BasePolicy
from stable_baselines3.common.utils import safe_mean
from stable_baselines3.common.vec_env import VecEnv
from stable_baselines3.common.type_aliases import GymEnv, RolloutReturn
from stable_baselines3.common.callbacks import BaseCallback
from stable_baselines3.common.noise import ActionNoise
from stable_baselines3.common.buffers import ReplayBuffer
class OffPolicyAlgorithm(BaseAlgorithm):
"""
The base for Off-Policy algorithms (ex: SAC/TD3)
:param policy: Policy object
:param env: The environment to learn from
(if registered in Gym, can be str. Can be None for loading trained models)
:param policy_base: The base policy used by this method
:param learning_rate: (float or callable) learning rate for the optimizer,
it can be a function of the current progress remaining (from 1 to 0)
:param buffer_size: (int) size of the replay buffer
:param learning_starts: (int) how many steps of the model to collect transitions for before learning starts
:param batch_size: (int) Minibatch size for each gradient update
:param policy_kwargs: Additional arguments to be passed to the policy on creation
:param tensorboard_log: (str) the log location for tensorboard (if None, no logging)
:param verbose: The verbosity level: 0 none, 1 training information, 2 debug
:param device: Device on which the code should run.
By default, it will try to use a Cuda compatible device and fallback to cpu
if it is not possible.
:param support_multi_env: Whether the algorithm supports training
with multiple environments (as in A2C)
:param create_eval_env: Whether to create a second environment that will be
used for evaluating the agent periodically. (Only available when passing string for the environment)
:param monitor_wrapper: When creating an environment, whether to wrap it
or not in a Monitor wrapper.
:param seed: Seed for the pseudo random generators
:param use_sde: Whether to use State Dependent Exploration (SDE)
instead of action noise exploration (default: False)
:param sde_sample_freq: Sample a new noise matrix every n steps when using gSDE
Default: -1 (only sample at the beginning of the rollout)
:param use_sde_at_warmup: (bool) Whether to use gSDE instead of uniform sampling
during the warm up phase (before learning starts)
:param sde_support: (bool) Whether the model support gSDE or not
"""
def __init__(self,
policy: Type[BasePolicy],
env: Union[GymEnv, str],
policy_base: Type[BasePolicy],
learning_rate: Union[float, Callable],
buffer_size: int = int(1e6),
learning_starts: int = 100,
batch_size: int = 256,
policy_kwargs: Dict[str, Any] = None,
tensorboard_log: Optional[str] = None,
verbose: int = 0,
device: Union[th.device, str] = 'auto',
support_multi_env: bool = False,
create_eval_env: bool = False,
monitor_wrapper: bool = True,
seed: Optional[int] = None,
use_sde: bool = False,
sde_sample_freq: int = -1,
use_sde_at_warmup: bool = False,
sde_support: bool = True):
super(OffPolicyAlgorithm, self).__init__(policy=policy, env=env, policy_base=policy_base,
learning_rate=learning_rate, policy_kwargs=policy_kwargs,
tensorboard_log=tensorboard_log, verbose=verbose,
device=device, support_multi_env=support_multi_env,
create_eval_env=create_eval_env, monitor_wrapper=monitor_wrapper,
seed=seed, use_sde=use_sde, sde_sample_freq=sde_sample_freq)
self.buffer_size = buffer_size
self.batch_size = batch_size
self.learning_starts = learning_starts
self.actor = None # type: Optional[th.nn.Module]
self.replay_buffer = None # type: Optional[ReplayBuffer]
# Update policy keyword arguments
if sde_support:
self.policy_kwargs['use_sde'] = self.use_sde
self.policy_kwargs['device'] = self.device
# For gSDE only
self.use_sde_at_warmup = use_sde_at_warmup
def _setup_model(self):
self._setup_lr_schedule()
self.set_random_seed(self.seed)
self.replay_buffer = ReplayBuffer(self.buffer_size, self.observation_space,
self.action_space, self.device)
self.policy = self.policy_class(self.observation_space, self.action_space,
self.lr_schedule, **self.policy_kwargs)
self.policy = self.policy.to(self.device)
def save_replay_buffer(self, path: str):
"""
Save the replay buffer as a pickle file.
:param path: (str) Path to the file where the replay buffer should be saved
"""
assert self.replay_buffer is not None, "The replay buffer is not defined"
with open(path, 'wb') as file_handler:
pickle.dump(self.replay_buffer, file_handler)
def load_replay_buffer(self, path: str):
"""
Load a replay buffer from a pickle file.
:param path: (str) Path to the pickled replay buffer.
"""
with open(path, 'rb') as file_handler:
self.replay_buffer = pickle.load(file_handler)
assert isinstance(self.replay_buffer, ReplayBuffer), 'The replay buffer must inherit from ReplayBuffer class'
def collect_rollouts(self, # noqa: C901
env: VecEnv,
# Type hint as string to avoid circular import
callback: 'BaseCallback',
n_episodes: int = 1,
n_steps: int = -1,
action_noise: Optional[ActionNoise] = None,
learning_starts: int = 0,
replay_buffer: Optional[ReplayBuffer] = None,
log_interval: Optional[int] = None) -> RolloutReturn:
"""
Collect experiences and store them into a ReplayBuffer.
:param env: (VecEnv) The training environment
:param callback: (BaseCallback) Callback that will be called at each step
(and at the beginning and end of the rollout)
:param n_episodes: (int) Number of episodes to use to collect rollout data
You can also specify a ``n_steps`` instead
:param n_steps: (int) Number of steps to use to collect rollout data
You can also specify a ``n_episodes`` instead.
:param action_noise: (Optional[ActionNoise]) Action noise that will be used for exploration
Required for deterministic policy (e.g. TD3). This can also be used
in addition to the stochastic policy for SAC.
:param learning_starts: (int) Number of steps before learning for the warm-up phase.
:param replay_buffer: (ReplayBuffer)
:param log_interval: (int) Log data every ``log_interval`` episodes
:return: (RolloutReturn)
"""
episode_rewards, total_timesteps = [], []
total_steps, total_episodes = 0, 0
assert isinstance(env, VecEnv), "You must pass a VecEnv"
assert env.num_envs == 1, "OffPolicyAlgorithm only support single environment"
if n_episodes > 0 and n_steps > 0:
# Note we are refering to the constructor arguments
# that are named `train_freq` and `n_episodes_rollout`
# but correspond to `n_steps` and `n_episodes` here
warnings.warn("You passed a positive value for `train_freq` and `n_episodes_rollout`."
"Please make sure this is intended. "
"The agent will collect data by stepping in the environment "
"until both conditions are true: "
"`number of steps in the env` >= `train_freq` and "
"`number of episodes` > `n_episodes_rollout`")
if self.use_sde:
self.actor.reset_noise()
callback.on_rollout_start()
continue_training = True
while total_steps < n_steps or total_episodes < n_episodes:
done = False
episode_reward, episode_timesteps = 0.0, 0
while not done:
if self.use_sde and self.sde_sample_freq > 0 and total_steps % self.sde_sample_freq == 0:
# Sample a new noise matrix
self.actor.reset_noise()
# Select action randomly or according to policy
if self.num_timesteps < learning_starts and not (self.use_sde and self.use_sde_at_warmup):
# Warmup phase
unscaled_action = np.array([self.action_space.sample()])
else:
# Note: we assume that the policy uses tanh to scale the action
# We use non-deterministic action in the case of SAC, for TD3, it does not matter
unscaled_action, _ = self.predict(self._last_obs, deterministic=False)
# Rescale the action from [low, high] to [-1, 1]
if isinstance(self.action_space, gym.spaces.Box):
scaled_action = self.policy.scale_action(unscaled_action)
# Add noise to the action (improve exploration)
if action_noise is not None:
# NOTE: in the original implementation of TD3, the noise was applied to the unscaled action
# Update(October 2019): Not anymore
scaled_action = np.clip(scaled_action + action_noise(), -1, 1)
# We store the scaled action in the buffer
buffer_action = scaled_action
action = self.policy.unscale_action(scaled_action)
else:
# Discrete case, no need to normalize or clip
buffer_action = unscaled_action
action = buffer_action
# Rescale and perform action
new_obs, reward, done, infos = env.step(action)
# Only stop training if return value is False, not when it is None.
if callback.on_step() is False:
return RolloutReturn(0.0, total_steps, total_episodes, continue_training=False)
episode_reward += reward
# Retrieve reward and episode length if using Monitor wrapper
self._update_info_buffer(infos, done)
# Store data in replay buffer
if replay_buffer is not None:
# Store only the unnormalized version
if self._vec_normalize_env is not None:
new_obs_ = self._vec_normalize_env.get_original_obs()
reward_ = self._vec_normalize_env.get_original_reward()
else:
# Avoid changing the original ones
self._last_original_obs, new_obs_, reward_ = self._last_obs, new_obs, reward
replay_buffer.add(self._last_original_obs, new_obs_, buffer_action, reward_, done)
self._last_obs = new_obs
# Save the unnormalized observation
if self._vec_normalize_env is not None:
self._last_original_obs = new_obs_
self.num_timesteps += 1
episode_timesteps += 1
total_steps += 1
if 0 < n_steps <= total_steps:
break
if done:
total_episodes += 1
self._episode_num += 1
episode_rewards.append(episode_reward)
total_timesteps.append(episode_timesteps)
if action_noise is not None:
action_noise.reset()
# Log training infos
if log_interval is not None and self._episode_num % log_interval == 0:
fps = int(self.num_timesteps / (time.time() - self.start_time))
logger.record("time/episodes", self._episode_num, exclude="tensorboard")
if len(self.ep_info_buffer) > 0 and len(self.ep_info_buffer[0]) > 0:
logger.record('rollout/ep_rew_mean', safe_mean([ep_info['r'] for ep_info in self.ep_info_buffer]))
logger.record('rollout/ep_len_mean', safe_mean([ep_info['l'] for ep_info in self.ep_info_buffer]))
logger.record("time/fps", fps)
logger.record('time/time_elapsed', int(time.time() - self.start_time), exclude="tensorboard")
logger.record("time/total timesteps", self.num_timesteps, exclude="tensorboard")
if self.use_sde:
logger.record("train/std", (self.actor.get_std()).mean().item())
if len(self.ep_success_buffer) > 0:
logger.record('rollout/success rate', safe_mean(self.ep_success_buffer))
# Pass the number of timesteps for tensorboard
logger.dump(step=self.num_timesteps)
mean_reward = np.mean(episode_rewards) if total_episodes > 0 else 0.0
callback.on_rollout_end()
return RolloutReturn(mean_reward, total_steps, total_episodes, continue_training)