stable-baselines3/torchy_baselines/common/base_class.py
2019-10-28 17:42:39 +01:00

394 lines
16 KiB
Python

import time
from abc import ABCMeta, abstractmethod
from collections import deque
import gym
import torch as th
import numpy as np
from torchy_baselines.common.policies import get_policy_from_name
from torchy_baselines.common.utils import set_random_seed, get_schedule_fn, update_learning_rate
from torchy_baselines.common.vec_env import DummyVecEnv, VecEnv
from torchy_baselines.common.monitor import Monitor
from torchy_baselines.common import logger
class BaseRLModel(object):
"""
The base RL model
:param policy: (BasePolicy) Policy object
:param env: (Gym environment) The environment to learn from
(if registered in Gym, can be str. Can be None for loading trained models)
:param verbose: (int) the verbosity level: 0 none, 1 training information, 2 debug
:param policy_base: (BasePolicy) the base policy used by this method
:param device: (str or th.device) Device on which the code should.
By default, it will try to use a Cuda compatible device and fallback to cpu
if it is not possible.
:param monitor_wrapper: (bool) When creating an environment, whether to wrap it
or not in a Monitor wrapper.
"""
__metaclass__ = ABCMeta
def __init__(self, policy, env, policy_base, policy_kwargs=None,
verbose=0, device='auto', support_multi_env=False,
create_eval_env=False, monitor_wrapper=True, seed=None):
if isinstance(policy, str) and policy_base is not None:
self.policy = get_policy_from_name(policy_base, policy)
else:
self.policy = policy
if device == 'auto':
device = 'cuda' if th.cuda.is_available() else 'cpu'
self.device = th.device(device)
if verbose > 0:
print("Using {} device".format(self.device))
self.env = env
self.verbose = verbose
self.policy_kwargs = {} if policy_kwargs is None else policy_kwargs
self.observation_space = None
self.action_space = None
self.n_envs = None
self.num_timesteps = 0
self.params = None
self.eval_env = None
self.replay_buffer = None
self.seed = seed
self.action_noise = None
# Track the training progress (from 1 to 0)
# this is used to update the learning rate
self._current_progress = 1
if env is not None:
if isinstance(env, str):
if create_eval_env:
eval_env = gym.make(env)
if monitor_wrapper:
eval_env = Monitor(eval_env, filename=None)
self.eval_env = DummyVecEnv([lambda: eval_env])
if self.verbose >= 1:
print("Creating environment from the given name, wrapped in a DummyVecEnv.")
env = gym.make(env)
if monitor_wrapper:
env = Monitor(env, filename=None)
env = DummyVecEnv([lambda: env])
self.observation_space = env.observation_space
self.action_space = env.action_space
if not isinstance(env, VecEnv):
if self.verbose >= 1:
print("Wrapping the env in a DummyVecEnv.")
env = DummyVecEnv([lambda: env])
self.n_envs = env.num_envs
self.env = env
if not support_multi_env and self.n_envs > 1:
raise ValueError("Error: the model does not support multiple envs requires a single vectorized"
" environment.")
def _get_eval_env(self, eval_env):
if eval_env is None:
eval_env = self.eval_env
if eval_env is not None:
if not isinstance(eval_env, VecEnv):
eval_env = DummyVecEnv([lambda: eval_env])
assert eval_env.num_envs == 1
return eval_env
def scale_action(self, action):
"""
Rescale the action from [low, high] to [-1, 1]
(no need for symmetric action space)
"""
low, high = self.action_space.low, self.action_space.high
return 2.0 * ((action - low) / (high - low)) - 1.0
def unscale_action(self, scaled_action):
"""
Rescale the action from [-1, 1] to [low, high]
(no need for symmetric action space)
"""
low, high = self.action_space.low, self.action_space.high
return low + (0.5 * (scaled_action + 1.0) * (high - low))
def _setup_learning_rate(self):
"""Transform to callable if needed."""
self.learning_rate = get_schedule_fn(self.learning_rate)
def _update_current_progress(self, num_timesteps, total_timesteps):
"""
Compute current progress (from 1 to 0)
:param num_timesteps: (int)
:param total_timesteps: (int)
"""
self._current_progress = 1.0 - float(num_timesteps) / float(total_timesteps)
def _update_learning_rate(self, optimizers):
"""
Update the optimizers learning rate using the current learning rate schedule
and the current progress (from 1 to 0).
:param optimizers: ([th.optim.Optimizer] or Optimizer) An optimizer
or a list of optimizer.
"""
# Log the current learning rate
logger.logkv("learning_rate", self.learning_rate(self._current_progress))
if not isinstance(optimizers, list):
optimizers = [optimizers]
for optimizer in optimizers:
update_learning_rate(optimizer, self.learning_rate(self._current_progress))
@staticmethod
def safe_mean(arr):
"""
Compute the mean of an array if there is at least one element.
For empty array, return nan. It is used for logging only.
:param arr: (np.ndarray)
:return: (float)
"""
return np.nan if len(arr) == 0 else np.mean(arr)
def get_env(self):
"""
returns the current environment (can be None if not defined)
:return: (Gym Environment) The current environment
"""
return self.env
def set_env(self, env):
"""
Checks the validity of the environment, and if it is coherent, set it as the current environment.
:param env: (Gym Environment) The environment for learning a policy
"""
pass
def get_parameter_list(self):
"""
Get pytorch Variables of model's parameters
This includes all variables necessary for continuing training (saving / loading).
:return: (list) List of pytorch Variables
"""
pass
def get_parameters(self):
"""
Get current model parameters as dictionary of variable name -> ndarray.
:return: (OrderedDict) Dictionary of variable name -> ndarray of model's parameters.
"""
raise NotImplementedError()
def pretrain(self, dataset, n_epochs=10, learning_rate=1e-4,
adam_epsilon=1e-8, val_interval=None):
"""
Pretrain a model using behavior cloning:
supervised learning given an expert dataset.
NOTE: only Box and Discrete spaces are supported for now.
:param dataset: (ExpertDataset) Dataset manager
:param n_epochs: (int) Number of iterations on the training set
:param learning_rate: (float) Learning rate
:param adam_epsilon: (float) the epsilon value for the adam optimizer
:param val_interval: (int) Report training and validation losses every n epochs.
By default, every 10th of the maximum number of epochs.
:return: (BaseRLModel) the pretrained model
"""
raise NotImplementedError()
@abstractmethod
def learn(self, total_timesteps, callback=None, log_interval=100, tb_log_name="run",
eval_env=None, eval_freq=-1, n_eval_episodes=5, reset_num_timesteps=True):
"""
Return a trained model.
:param total_timesteps: (int) The total number of samples to train on
:param seed: (int) The initial seed for training, if None: keep current seed
:param callback: (function (dict, dict)) -> boolean function called at every steps with state of the algorithm.
It takes the local and global variables. If it returns False, training is aborted.
:param log_interval: (int) The number of timesteps before logging.
:param tb_log_name: (str) the name of the run for tensorboard log
:param reset_num_timesteps: (bool) whether or not to reset the current timestep number (used in logging)
:return: (BaseRLModel) the trained model
"""
pass
@abstractmethod
def predict(self, observation, state=None, mask=None, deterministic=False):
"""
Get the model's action from an observation
:param observation: (np.ndarray) the input observation
:param state: (np.ndarray) The last states (can be None, used in recurrent policies)
:param mask: (np.ndarray) The last masks (can be None, used in recurrent policies)
:param deterministic: (bool) Whether or not to return deterministic actions.
:return: (np.ndarray, np.ndarray) the model's action and the next state (used in recurrent policies)
"""
pass
def load_parameters(self, load_path_or_dict, exact_match=True):
"""
Load model parameters from a file or a dictionary
Dictionary keys should be tensorflow variable names, which can be obtained
with ``get_parameters`` function. If ``exact_match`` is True, dictionary
should contain keys for all model's parameters, otherwise RunTimeError
is raised. If False, only variables included in the dictionary will be updated.
This does not load agent's hyper-parameters.
.. warning::
This function does not update trainer/optimizer variables (e.g. momentum).
As such training after using this function may lead to less-than-optimal results.
:param load_path_or_dict: (str or file-like or dict) Save parameter location
or dict of parameters as variable.name -> ndarrays to be loaded.
:param exact_match: (bool) If True, expects load dictionary to contain keys for
all variables in the model. If False, loads parameters only for variables
mentioned in the dictionary. Defaults to True.
"""
raise NotImplementedError()
@abstractmethod
def save(self, save_path):
"""
Save the current parameters to file
:param save_path: (str or file-like object) the save location
"""
raise NotImplementedError()
@classmethod
@abstractmethod
def load(cls, load_path, env=None, **kwargs):
"""
Load the model from file
:param load_path: (str or file-like) the saved parameter location
:param env: (Gym Envrionment) the new environment to run the loaded model on
(can be None if you only need prediction from a trained model)
:param kwargs: extra arguments to change the model when loading
"""
raise NotImplementedError()
def set_random_seed(self, seed=0):
set_random_seed(seed, using_cuda=self.device == th.device('cuda'))
self.action_space.seed(seed)
if self.env is not None:
self.env.seed(seed)
if self.eval_env is not None:
self.eval_env.seed(seed)
def _setup_learn(self, eval_env):
self.start_time = time.time()
self.ep_info_buffer = deque(maxlen=100)
if self.action_noise is not None:
self.action_noise.reset()
timesteps_since_eval, episode_num = 0, 0
evaluations = []
if eval_env is not None and self.seed is not None:
eval_env.seed(self.seed)
eval_env = self._get_eval_env(eval_env)
obs = self.env.reset()
return timesteps_since_eval, episode_num, evaluations, obs, eval_env
def _update_info_buffer(self, infos):
"""
Retrieve reward and episode length if using Monitor wrapper.
:param infos: ([dict])
"""
for info in infos:
maybe_ep_info = info.get('episode')
if maybe_ep_info is not None:
self.ep_info_buffer.extend([maybe_ep_info])
def collect_rollouts(self, env, n_episodes=1, n_steps=-1, action_noise=None,
deterministic=False, callback=None,
learning_starts=0, num_timesteps=0,
replay_buffer=None, obs=None,
episode_num=0, log_interval=None):
episode_rewards = []
total_timesteps = []
total_steps, total_episodes = 0, 0
assert isinstance(env, VecEnv)
assert env.num_envs == 1
while total_steps < n_steps or total_episodes < n_episodes:
done = False
# Reset environment: not needed for VecEnv
# obs = env.reset()
episode_reward, episode_timesteps = 0.0, 0
while not done:
# Select action randomly or according to policy
if num_timesteps < learning_starts:
action = np.array([self.action_space.sample()])
else:
action = self.predict(obs, deterministic=deterministic)
# Rescale the action from [low, high] to [-1, 1]
action = self.scale_action(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
action = np.clip(action + action_noise(), -1, 1)
# Rescale and perform action
new_obs, reward, done, infos = env.step(self.unscale_action(action))
done_bool = [float(done[0])]
episode_reward += reward
# Retrieve reward and episode length if using Monitor wrapper
self._update_info_buffer(infos)
# Store data in replay buffer
if replay_buffer is not None:
replay_buffer.add(obs, new_obs, action, reward, done_bool)
obs = new_obs
num_timesteps += 1
episode_timesteps += 1
total_steps += 1
if n_steps > 0 and total_steps >= n_steps:
break
if done:
total_episodes += 1
episode_rewards.append(episode_reward)
total_timesteps.append(episode_timesteps)
if action_noise is not None:
action_noise.reset()
# Display training infos
if self.verbose >= 1 and log_interval is not None and (episode_num + total_episodes) % log_interval == 0:
fps = int(num_timesteps / (time.time() - self.start_time))
logger.logkv("episodes", episode_num + total_episodes)
# logger.logkv("mean 100 episode reward", mean_reward)
if len(self.ep_info_buffer) > 0 and len(self.ep_info_buffer[0]) > 0:
logger.logkv('ep_rew_mean', self.safe_mean([ep_info['r'] for ep_info in self.ep_info_buffer]))
logger.logkv('ep_len_mean', self.safe_mean([ep_info['l'] for ep_info in self.ep_info_buffer]))
# logger.logkv("n_updates", n_updates)
# logger.logkv("current_lr", current_lr)
logger.logkv("fps", fps)
logger.logkv('time_elapsed', int(time.time() - self.start_time))
logger.logkv("total timesteps", num_timesteps)
logger.dumpkvs()
mean_reward = np.mean(episode_rewards) if total_episodes > 0 else 0.0
return mean_reward, total_steps, total_episodes, obs