import argparse
import importlib
import os
import pickle as pkl
import time
import warnings
from collections import OrderedDict
from pathlib import Path
from pprint import pprint
from typing import Any, Callable, Dict, List, Optional, Tuple, Union
import gymnasium as gym
import numpy as np
import optuna
import torch as th
import yaml
from gymnasium import spaces
from huggingface_sb3 import EnvironmentName
from optuna.pruners import BasePruner, MedianPruner, NopPruner, SuccessiveHalvingPruner
from optuna.samplers import BaseSampler, RandomSampler, TPESampler
from optuna.study import MaxTrialsCallback
from optuna.trial import TrialState
from optuna.visualization import plot_optimization_history, plot_param_importances
from sb3_contrib.common.vec_env import AsyncEval
# For using HER with GoalEnv
from stable_baselines3 import HerReplayBuffer
from stable_baselines3.common.base_class import BaseAlgorithm
from stable_baselines3.common.callbacks import BaseCallback, CheckpointCallback, EvalCallback, ProgressBarCallback
from stable_baselines3.common.env_util import make_vec_env
from stable_baselines3.common.noise import NormalActionNoise, OrnsteinUhlenbeckActionNoise
from stable_baselines3.common.preprocessing import is_image_space, is_image_space_channels_first
from stable_baselines3.common.sb2_compat.rmsprop_tf_like import RMSpropTFLike # noqa: F401
from stable_baselines3.common.utils import constant_fn
from stable_baselines3.common.vec_env import (
DummyVecEnv,
SubprocVecEnv,
VecEnv,
VecFrameStack,
VecNormalize,
VecTransposeImage,
is_vecenv_wrapped,
)
# For custom activation fn
from torch import nn as nn
# Register custom envs
import rl_zoo3.import_envs # noqa: F401
from rl_zoo3.callbacks import SaveVecNormalizeCallback, TrialEvalCallback
from rl_zoo3.hyperparams_opt import HYPERPARAMS_SAMPLER
from rl_zoo3.utils import ALGOS, get_callback_list, get_class_by_name, get_latest_run_id, get_wrapper_class, linear_schedule
[docs]class ExperimentManager:
"""
Experiment manager: read the hyperparameters,
preprocess them, create the environment and the RL model.
Please take a look at `train.py` to have the details for each argument.
"""
def __init__(
self,
args: argparse.Namespace,
algo: str,
env_id: str,
log_folder: str,
tensorboard_log: str = "",
n_timesteps: int = 0,
eval_freq: int = 10000,
n_eval_episodes: int = 5,
save_freq: int = -1,
hyperparams: Optional[Dict[str, Any]] = None,
env_kwargs: Optional[Dict[str, Any]] = None,
eval_env_kwargs: Optional[Dict[str, Any]] = None,
trained_agent: str = "",
optimize_hyperparameters: bool = False,
storage: Optional[str] = None,
study_name: Optional[str] = None,
n_trials: int = 1,
max_total_trials: Optional[int] = None,
n_jobs: int = 1,
sampler: str = "tpe",
pruner: str = "median",
optimization_log_path: Optional[str] = None,
n_startup_trials: int = 0,
n_evaluations: int = 1,
truncate_last_trajectory: bool = False,
uuid_str: str = "",
seed: int = 0,
log_interval: int = 0,
save_replay_buffer: bool = False,
verbose: int = 1,
vec_env_type: str = "dummy",
n_eval_envs: int = 1,
no_optim_plots: bool = False,
device: Union[th.device, str] = "auto",
config: Optional[str] = None,
show_progress: bool = False,
):
super().__init__()
self.algo = algo
self.env_name = EnvironmentName(env_id)
# Custom params
self.custom_hyperparams = hyperparams
if (Path(__file__).parent / "hyperparams").is_dir():
# Package version
default_path = Path(__file__).parent
else:
# Take the root folder
default_path = Path(__file__).parent.parent
self.config = config or str(default_path / f"hyperparams/{self.algo}.yml")
self.env_kwargs: Dict[str, Any] = env_kwargs or {}
self.n_timesteps = n_timesteps
self.normalize = False
self.normalize_kwargs: Dict[str, Any] = {}
self.env_wrapper: Optional[Callable] = None
self.frame_stack = None
self.seed = seed
self.optimization_log_path = optimization_log_path
self.vec_env_class = {"dummy": DummyVecEnv, "subproc": SubprocVecEnv}[vec_env_type]
self.vec_env_wrapper: Optional[Callable] = None
self.vec_env_kwargs: Dict[str, Any] = {}
# self.vec_env_kwargs = {} if vec_env_type == "dummy" else {"start_method": "fork"}
# Callbacks
self.specified_callbacks: List = []
self.callbacks: List[BaseCallback] = []
# Use env-kwargs if eval_env_kwargs was not specified
self.eval_env_kwargs: Dict[str, Any] = eval_env_kwargs or self.env_kwargs
self.save_freq = save_freq
self.eval_freq = eval_freq
self.n_eval_episodes = n_eval_episodes
self.n_eval_envs = n_eval_envs
self.n_envs = 1 # it will be updated when reading hyperparams
self.n_actions = 0 # For DDPG/TD3 action noise objects
self._hyperparams: Dict[str, Any] = {}
self.monitor_kwargs: Dict[str, Any] = {}
self.trained_agent = trained_agent
self.continue_training = trained_agent.endswith(".zip") and os.path.isfile(trained_agent)
self.truncate_last_trajectory = truncate_last_trajectory
self._is_atari = self.is_atari(env_id)
# Hyperparameter optimization config
self.optimize_hyperparameters = optimize_hyperparameters
self.storage = storage
self.study_name = study_name
self.no_optim_plots = no_optim_plots
# maximum number of trials for finding the best hyperparams
self.n_trials = n_trials
self.max_total_trials = max_total_trials
# number of parallel jobs when doing hyperparameter search
self.n_jobs = n_jobs
self.sampler = sampler
self.pruner = pruner
self.n_startup_trials = n_startup_trials
self.n_evaluations = n_evaluations
self.deterministic_eval = not (self.is_atari(env_id) or self.is_minigrid(env_id))
self.device = device
# Logging
self.log_folder = log_folder
self.tensorboard_log = None if tensorboard_log == "" else os.path.join(tensorboard_log, self.env_name)
self.verbose = verbose
self.args = args
self.log_interval = log_interval
self.save_replay_buffer = save_replay_buffer
self.show_progress = show_progress
self.log_path = f"{log_folder}/{self.algo}/"
self.save_path = os.path.join(
self.log_path, f"{self.env_name}_{get_latest_run_id(self.log_path, self.env_name) + 1}{uuid_str}"
)
self.params_path = f"{self.save_path}/{self.env_name}"
[docs] def setup_experiment(self) -> Optional[Tuple[BaseAlgorithm, Dict[str, Any]]]:
"""
Read hyperparameters, pre-process them (create schedules, wrappers, callbacks, action noise objects)
create the environment and possibly the model.
:return: the initialized RL model
"""
unprocessed_hyperparams, saved_hyperparams = self.read_hyperparameters()
hyperparams, self.env_wrapper, self.callbacks, self.vec_env_wrapper = self._preprocess_hyperparams(
unprocessed_hyperparams
)
self.create_log_folder()
self.create_callbacks()
# Create env to have access to action space for action noise
n_envs = 1 if self.algo == "ars" or self.optimize_hyperparameters else self.n_envs
env = self.create_envs(n_envs, no_log=False)
self._hyperparams = self._preprocess_action_noise(hyperparams, saved_hyperparams, env)
if self.continue_training:
model = self._load_pretrained_agent(self._hyperparams, env)
elif self.optimize_hyperparameters:
env.close()
return None
else:
# Train an agent from scratch
model = ALGOS[self.algo](
env=env,
tensorboard_log=self.tensorboard_log,
seed=self.seed,
verbose=self.verbose,
device=self.device,
**self._hyperparams,
)
self._save_config(saved_hyperparams)
return model, saved_hyperparams
[docs] def learn(self, model: BaseAlgorithm) -> None:
"""
:param model: an initialized RL model
"""
kwargs: Dict[str, Any] = {}
if self.log_interval > -1:
kwargs = {"log_interval": self.log_interval}
if len(self.callbacks) > 0:
kwargs["callback"] = self.callbacks
# Special case for ARS
if self.algo == "ars" and self.n_envs > 1:
kwargs["async_eval"] = AsyncEval(
[lambda: self.create_envs(n_envs=1, no_log=True) for _ in range(self.n_envs)], model.policy
)
try:
model.learn(self.n_timesteps, **kwargs)
except KeyboardInterrupt:
# this allows to save the model when interrupting training
pass
finally:
# Clean progress bar
if len(self.callbacks) > 0:
self.callbacks[0].on_training_end()
# Release resources
try:
assert model.env is not None
model.env.close()
except EOFError:
pass
[docs] def save_trained_model(self, model: BaseAlgorithm) -> None:
"""
Save trained model optionally with its replay buffer
and ``VecNormalize`` statistics
:param model:
"""
print(f"Saving to {self.save_path}")
model.save(f"{self.save_path}/{self.env_name}")
if hasattr(model, "save_replay_buffer") and self.save_replay_buffer:
print("Saving replay buffer")
model.save_replay_buffer(os.path.join(self.save_path, "replay_buffer.pkl"))
if self.normalize:
# Important: save the running average, for testing the agent we need that normalization
vec_normalize = model.get_vec_normalize_env()
assert vec_normalize is not None
vec_normalize.save(os.path.join(self.params_path, "vecnormalize.pkl"))
def _save_config(self, saved_hyperparams: Dict[str, Any]) -> None:
"""
Save unprocessed hyperparameters, this can be use later
to reproduce an experiment.
:param saved_hyperparams:
"""
# Save hyperparams
with open(os.path.join(self.params_path, "config.yml"), "w") as f:
yaml.dump(saved_hyperparams, f)
# save command line arguments
with open(os.path.join(self.params_path, "args.yml"), "w") as f:
ordered_args = OrderedDict([(key, vars(self.args)[key]) for key in sorted(vars(self.args).keys())])
yaml.dump(ordered_args, f)
print(f"Log path: {self.save_path}")
def read_hyperparameters(self) -> Tuple[Dict[str, Any], Dict[str, Any]]:
print(f"Loading hyperparameters from: {self.config}")
if self.config.endswith(".yml") or self.config.endswith(".yaml"):
# Load hyperparameters from yaml file
with open(self.config) as f:
hyperparams_dict = yaml.safe_load(f)
elif self.config.endswith(".py"):
global_variables: Dict = {}
# Load hyperparameters from python file
exec(Path(self.config).read_text(), global_variables)
hyperparams_dict = global_variables["hyperparams"]
else:
# Load hyperparameters from python package
hyperparams_dict = importlib.import_module(self.config).hyperparams
# raise ValueError(f"Unsupported config file format: {self.config}")
if self.env_name.gym_id in list(hyperparams_dict.keys()):
hyperparams = hyperparams_dict[self.env_name.gym_id]
elif self._is_atari:
hyperparams = hyperparams_dict["atari"]
else:
raise ValueError(f"Hyperparameters not found for {self.algo}-{self.env_name.gym_id} in {self.config}")
if self.custom_hyperparams is not None:
# Overwrite hyperparams if needed
hyperparams.update(self.custom_hyperparams)
# Sort hyperparams that will be saved
saved_hyperparams = OrderedDict([(key, hyperparams[key]) for key in sorted(hyperparams.keys())])
# Always print used hyperparameters
print("Default hyperparameters for environment (ones being tuned will be overridden):")
pprint(saved_hyperparams)
return hyperparams, saved_hyperparams
@staticmethod
def _preprocess_schedules(hyperparams: Dict[str, Any]) -> Dict[str, Any]:
# Create schedules
for key in ["learning_rate", "clip_range", "clip_range_vf", "delta_std"]:
if key not in hyperparams:
continue
if isinstance(hyperparams[key], str):
schedule, initial_value = hyperparams[key].split("_")
initial_value = float(initial_value)
hyperparams[key] = linear_schedule(initial_value)
elif isinstance(hyperparams[key], (float, int)):
# Negative value: ignore (ex: for clipping)
if hyperparams[key] < 0:
continue
hyperparams[key] = constant_fn(float(hyperparams[key]))
else:
raise ValueError(f"Invalid value for {key}: {hyperparams[key]}")
return hyperparams
def _preprocess_normalization(self, hyperparams: Dict[str, Any]) -> Dict[str, Any]:
if "normalize" in hyperparams.keys():
self.normalize = hyperparams["normalize"]
# Special case, instead of both normalizing
# both observation and reward, we can normalize one of the two.
# in that case `hyperparams["normalize"]` is a string
# that can be evaluated as python,
# ex: "dict(norm_obs=False, norm_reward=True)"
if isinstance(self.normalize, str):
self.normalize_kwargs = eval(self.normalize)
self.normalize = True
if isinstance(self.normalize, dict):
self.normalize_kwargs = self.normalize
self.normalize = True
# Use the same discount factor as for the algorithm
if "gamma" in hyperparams:
self.normalize_kwargs["gamma"] = hyperparams["gamma"]
del hyperparams["normalize"]
return hyperparams
def _preprocess_hyperparams( # noqa: C901
self, hyperparams: Dict[str, Any]
) -> Tuple[Dict[str, Any], Optional[Callable], List[BaseCallback], Optional[Callable]]:
self.n_envs = hyperparams.get("n_envs", 1)
if self.verbose > 0:
print(f"Using {self.n_envs} environments")
# Convert schedule strings to objects
hyperparams = self._preprocess_schedules(hyperparams)
# Pre-process train_freq
if "train_freq" in hyperparams and isinstance(hyperparams["train_freq"], list):
hyperparams["train_freq"] = tuple(hyperparams["train_freq"])
# Should we overwrite the number of timesteps?
if self.n_timesteps > 0:
if self.verbose:
print(f"Overwriting n_timesteps with n={self.n_timesteps}")
else:
self.n_timesteps = int(hyperparams["n_timesteps"])
# Derive n_evaluations from number of timesteps if needed
if self.n_evaluations is None and self.optimize_hyperparameters:
self.n_evaluations = max(1, self.n_timesteps // int(1e5))
print(
f"Doing {self.n_evaluations} intermediate evaluations for pruning based on the number of timesteps."
" (1 evaluation every 100k timesteps)"
)
# Pre-process normalize config
hyperparams = self._preprocess_normalization(hyperparams)
# Pre-process policy/buffer keyword arguments
# Convert to python object if needed
for kwargs_key in {"policy_kwargs", "replay_buffer_class", "replay_buffer_kwargs"}:
if kwargs_key in hyperparams.keys() and isinstance(hyperparams[kwargs_key], str):
hyperparams[kwargs_key] = eval(hyperparams[kwargs_key])
# Preprocess monitor kwargs
if "monitor_kwargs" in hyperparams.keys():
self.monitor_kwargs = hyperparams["monitor_kwargs"]
# Convert str to python code
if isinstance(self.monitor_kwargs, str):
self.monitor_kwargs = eval(self.monitor_kwargs)
del hyperparams["monitor_kwargs"]
# Delete keys so the dict can be pass to the model constructor
if "n_envs" in hyperparams.keys():
del hyperparams["n_envs"]
del hyperparams["n_timesteps"]
if "frame_stack" in hyperparams.keys():
self.frame_stack = hyperparams["frame_stack"]
del hyperparams["frame_stack"]
# import the policy when using a custom policy
if "policy" in hyperparams and "." in hyperparams["policy"]:
hyperparams["policy"] = get_class_by_name(hyperparams["policy"])
# obtain a class object from a wrapper name string in hyperparams
# and delete the entry
env_wrapper = get_wrapper_class(hyperparams)
if "env_wrapper" in hyperparams.keys():
del hyperparams["env_wrapper"]
# Same for VecEnvWrapper
vec_env_wrapper = get_wrapper_class(hyperparams, "vec_env_wrapper")
if "vec_env_wrapper" in hyperparams.keys():
del hyperparams["vec_env_wrapper"]
callbacks = get_callback_list(hyperparams)
if "callback" in hyperparams.keys():
self.specified_callbacks = hyperparams["callback"]
del hyperparams["callback"]
return hyperparams, env_wrapper, callbacks, vec_env_wrapper
def _preprocess_action_noise(
self, hyperparams: Dict[str, Any], saved_hyperparams: Dict[str, Any], env: VecEnv
) -> Dict[str, Any]:
# Parse noise string
# Note: only off-policy algorithms are supported
if hyperparams.get("noise_type") is not None:
noise_type = hyperparams["noise_type"].strip()
noise_std = hyperparams["noise_std"]
# Save for later (hyperparameter optimization)
assert isinstance(
env.action_space, spaces.Box
), f"Action noise can only be used with Box action space, not {env.action_space}"
self.n_actions = env.action_space.shape[0]
if "normal" in noise_type:
hyperparams["action_noise"] = NormalActionNoise(
mean=np.zeros(self.n_actions),
sigma=noise_std * np.ones(self.n_actions),
)
elif "ornstein-uhlenbeck" in noise_type:
hyperparams["action_noise"] = OrnsteinUhlenbeckActionNoise(
mean=np.zeros(self.n_actions),
sigma=noise_std * np.ones(self.n_actions),
)
else:
raise RuntimeError(f'Unknown noise type "{noise_type}"')
print(f"Applying {noise_type} noise with std {noise_std}")
del hyperparams["noise_type"]
del hyperparams["noise_std"]
return hyperparams
def create_log_folder(self):
os.makedirs(self.params_path, exist_ok=True)
def create_callbacks(self):
if self.show_progress:
self.callbacks.append(ProgressBarCallback())
if self.save_freq > 0:
# Account for the number of parallel environments
self.save_freq = max(self.save_freq // self.n_envs, 1)
self.callbacks.append(
CheckpointCallback(
save_freq=self.save_freq,
save_path=self.save_path,
name_prefix="rl_model",
verbose=1,
)
)
# Create test env if needed, do not normalize reward
if self.eval_freq > 0 and not self.optimize_hyperparameters:
# Account for the number of parallel environments
self.eval_freq = max(self.eval_freq // self.n_envs, 1)
if self.verbose > 0:
print("Creating test environment")
save_vec_normalize = SaveVecNormalizeCallback(save_freq=1, save_path=self.params_path)
eval_callback = EvalCallback(
self.create_envs(self.n_eval_envs, eval_env=True),
callback_on_new_best=save_vec_normalize,
best_model_save_path=self.save_path,
n_eval_episodes=self.n_eval_episodes,
log_path=self.save_path,
eval_freq=self.eval_freq,
deterministic=self.deterministic_eval,
)
self.callbacks.append(eval_callback)
@staticmethod
def entry_point(env_id: str) -> str:
return str(gym.envs.registry[env_id].entry_point)
@staticmethod
def is_atari(env_id: str) -> bool:
return "AtariEnv" in ExperimentManager.entry_point(env_id)
@staticmethod
def is_minigrid(env_id: str) -> bool:
return "minigrid" in ExperimentManager.entry_point(env_id)
@staticmethod
def is_bullet(env_id: str) -> bool:
return "pybullet_envs" in ExperimentManager.entry_point(env_id)
@staticmethod
def is_robotics_env(env_id: str) -> bool:
return "gym.envs.robotics" in ExperimentManager.entry_point(
env_id
) or "panda_gym.envs" in ExperimentManager.entry_point(env_id)
@staticmethod
def is_panda_gym(env_id: str) -> bool:
return "panda_gym.envs" in ExperimentManager.entry_point(env_id)
def _maybe_normalize(self, env: VecEnv, eval_env: bool) -> VecEnv:
"""
Wrap the env into a VecNormalize wrapper if needed
and load saved statistics when present.
:param env:
:param eval_env:
:return:
"""
# Pretrained model, load normalization
path_ = os.path.join(os.path.dirname(self.trained_agent), self.env_name)
path_ = os.path.join(path_, "vecnormalize.pkl")
if os.path.exists(path_):
print("Loading saved VecNormalize stats")
env = VecNormalize.load(path_, env)
# Deactivate training and reward normalization
if eval_env:
env.training = False
env.norm_reward = False
elif self.normalize:
# Copy to avoid changing default values by reference
local_normalize_kwargs = self.normalize_kwargs.copy()
# In eval env: turn off reward normalization and normalization stats updates.
if eval_env:
local_normalize_kwargs["norm_reward"] = False
local_normalize_kwargs["training"] = False
if self.verbose > 0:
if len(local_normalize_kwargs) > 0:
print(f"Normalization activated: {local_normalize_kwargs}")
else:
print("Normalizing input and reward")
env = VecNormalize(env, **local_normalize_kwargs)
return env
[docs] def create_envs(self, n_envs: int, eval_env: bool = False, no_log: bool = False) -> VecEnv:
"""
Create the environment and wrap it if necessary.
:param n_envs:
:param eval_env: Whether is it an environment used for evaluation or not
:param no_log: Do not log training when doing hyperparameter optim
(issue with writing the same file)
:return: the vectorized environment, with appropriate wrappers
"""
# Do not log eval env (issue with writing the same file)
log_dir = None if eval_env or no_log else self.save_path
# Special case for GoalEnvs: log success rate too
if (
"Neck" in self.env_name.gym_id
or self.is_robotics_env(self.env_name.gym_id)
or "parking-v0" in self.env_name.gym_id
and len(self.monitor_kwargs) == 0 # do not overwrite custom kwargs
):
self.monitor_kwargs = dict(info_keywords=("is_success",))
spec = gym.spec(self.env_name.gym_id)
# Define make_env here, so it works with subprocesses
# when the registry was modified with `--gym-packages`
# See https://github.com/HumanCompatibleAI/imitation/pull/160
def make_env(**kwargs) -> gym.Env:
return spec.make(**kwargs)
env_kwargs = self.eval_env_kwargs if eval_env else self.env_kwargs
# On most env, SubprocVecEnv does not help and is quite memory hungry,
# therefore, we use DummyVecEnv by default
env = make_vec_env(
make_env,
n_envs=n_envs,
seed=self.seed,
env_kwargs=env_kwargs,
monitor_dir=log_dir,
wrapper_class=self.env_wrapper,
vec_env_cls=self.vec_env_class, # type: ignore[arg-type]
vec_env_kwargs=self.vec_env_kwargs,
monitor_kwargs=self.monitor_kwargs,
)
if self.vec_env_wrapper is not None:
env = self.vec_env_wrapper(env)
# Wrap the env into a VecNormalize wrapper if needed
# and load saved statistics when present
env = self._maybe_normalize(env, eval_env)
# Optional Frame-stacking
if self.frame_stack is not None:
n_stack = self.frame_stack
env = VecFrameStack(env, n_stack)
if self.verbose > 0:
print(f"Stacking {n_stack} frames")
if not is_vecenv_wrapped(env, VecTransposeImage):
wrap_with_vectranspose = False
if isinstance(env.observation_space, spaces.Dict):
# If even one of the keys is an image-space in need of transpose, apply transpose
# If the image spaces are not consistent (for instance, one is channel first,
# the other channel last); VecTransposeImage will throw an error
for space in env.observation_space.spaces.values():
wrap_with_vectranspose = wrap_with_vectranspose or (
is_image_space(space) and not is_image_space_channels_first(space) # type: ignore[arg-type]
)
else:
wrap_with_vectranspose = is_image_space(env.observation_space) and not is_image_space_channels_first(
env.observation_space # type: ignore[arg-type]
)
if wrap_with_vectranspose:
if self.verbose >= 1:
print("Wrapping the env in a VecTransposeImage.")
env = VecTransposeImage(env)
return env
def _load_pretrained_agent(self, hyperparams: Dict[str, Any], env: VecEnv) -> BaseAlgorithm:
# Continue training
print("Loading pretrained agent")
# Policy should not be changed
del hyperparams["policy"]
if "policy_kwargs" in hyperparams.keys():
del hyperparams["policy_kwargs"]
model = ALGOS[self.algo].load(
self.trained_agent,
env=env,
seed=self.seed,
tensorboard_log=self.tensorboard_log,
verbose=self.verbose,
device=self.device,
**hyperparams,
)
replay_buffer_path = os.path.join(os.path.dirname(self.trained_agent), "replay_buffer.pkl")
if os.path.exists(replay_buffer_path):
print("Loading replay buffer")
# `truncate_last_traj` will be taken into account only if we use HER replay buffer
assert hasattr(
model, "load_replay_buffer"
), "The current model doesn't have a `load_replay_buffer` to load the replay buffer"
model.load_replay_buffer(replay_buffer_path, truncate_last_traj=self.truncate_last_trajectory)
return model
def _create_sampler(self, sampler_method: str) -> BaseSampler:
# n_warmup_steps: Disable pruner until the trial reaches the given number of steps.
if sampler_method == "random":
sampler: BaseSampler = RandomSampler(seed=self.seed)
elif sampler_method == "tpe":
sampler = TPESampler(n_startup_trials=self.n_startup_trials, seed=self.seed, multivariate=True)
elif sampler_method == "skopt":
from optuna.integration.skopt import SkoptSampler
# cf https://scikit-optimize.github.io/#skopt.Optimizer
# GP: gaussian process
# Gradient boosted regression: GBRT
sampler = SkoptSampler(skopt_kwargs={"base_estimator": "GP", "acq_func": "gp_hedge"})
else:
raise ValueError(f"Unknown sampler: {sampler_method}")
return sampler
def _create_pruner(self, pruner_method: str) -> BasePruner:
if pruner_method == "halving":
pruner: BasePruner = SuccessiveHalvingPruner(min_resource=1, reduction_factor=4, min_early_stopping_rate=0)
elif pruner_method == "median":
pruner = MedianPruner(n_startup_trials=self.n_startup_trials, n_warmup_steps=self.n_evaluations // 3)
elif pruner_method == "none":
# Do not prune
pruner = NopPruner()
else:
raise ValueError(f"Unknown pruner: {pruner_method}")
return pruner
def objective(self, trial: optuna.Trial) -> float:
kwargs = self._hyperparams.copy()
n_envs = 1 if self.algo == "ars" else self.n_envs
additional_args = {
"using_her_replay_buffer": kwargs.get("replay_buffer_class") == HerReplayBuffer,
"her_kwargs": kwargs.get("replay_buffer_kwargs", {}),
}
# Pass n_actions to initialize DDPG/TD3 noise sampler
# Sample candidate hyperparameters
sampled_hyperparams = HYPERPARAMS_SAMPLER[self.algo](trial, self.n_actions, n_envs, additional_args)
kwargs.update(sampled_hyperparams)
env = self.create_envs(n_envs, no_log=True)
# By default, do not activate verbose output to keep
# stdout clean with only the trial's results
trial_verbosity = 0
# Activate verbose mode for the trial in debug mode
# See PR #214
if self.verbose >= 2:
trial_verbosity = self.verbose
model = ALGOS[self.algo](
env=env,
tensorboard_log=None,
# We do not seed the trial
seed=None,
verbose=trial_verbosity,
device=self.device,
**kwargs,
)
eval_env = self.create_envs(n_envs=self.n_eval_envs, eval_env=True)
optuna_eval_freq = int(self.n_timesteps / self.n_evaluations)
# Account for parallel envs
optuna_eval_freq = max(optuna_eval_freq // self.n_envs, 1)
# Use non-deterministic eval for Atari
path = None
if self.optimization_log_path is not None:
path = os.path.join(self.optimization_log_path, f"trial_{trial.number!s}")
callbacks = get_callback_list({"callback": self.specified_callbacks})
eval_callback = TrialEvalCallback(
eval_env,
trial,
best_model_save_path=path,
log_path=path,
n_eval_episodes=self.n_eval_episodes,
eval_freq=optuna_eval_freq,
deterministic=self.deterministic_eval,
)
callbacks.append(eval_callback)
learn_kwargs = {}
# Special case for ARS
if self.algo == "ars" and self.n_envs > 1:
learn_kwargs["async_eval"] = AsyncEval(
[lambda: self.create_envs(n_envs=1, no_log=True) for _ in range(self.n_envs)], model.policy
)
try:
model.learn(self.n_timesteps, callback=callbacks, **learn_kwargs) # type: ignore[arg-type]
# Free memory
assert model.env is not None
model.env.close()
eval_env.close()
except (AssertionError, ValueError) as e:
# Sometimes, random hyperparams can generate NaN
# Free memory
assert model.env is not None
model.env.close()
eval_env.close()
# Prune hyperparams that generate NaNs
print(e)
print("============")
print("Sampled hyperparams:")
pprint(sampled_hyperparams)
raise optuna.exceptions.TrialPruned() from e
is_pruned = eval_callback.is_pruned
reward = eval_callback.last_mean_reward
del model.env, eval_env
del model
if is_pruned:
raise optuna.exceptions.TrialPruned()
return reward
def hyperparameters_optimization(self) -> None:
if self.verbose > 0:
print("Optimizing hyperparameters")
if self.storage is not None and self.study_name is None:
warnings.warn(
f"You passed a remote storage: {self.storage} but no `--study-name`."
"The study name will be generated by Optuna, make sure to re-use the same study name "
"when you want to do distributed hyperparameter optimization."
)
if self.tensorboard_log is not None:
warnings.warn("Tensorboard log is deactivated when running hyperparameter optimization")
self.tensorboard_log = None
# TODO: eval each hyperparams several times to account for noisy evaluation
sampler = self._create_sampler(self.sampler)
pruner = self._create_pruner(self.pruner)
if self.verbose > 0:
print(f"Sampler: {self.sampler} - Pruner: {self.pruner}")
study = optuna.create_study(
sampler=sampler,
pruner=pruner,
storage=self.storage,
study_name=self.study_name,
load_if_exists=True,
direction="maximize",
)
try:
if self.max_total_trials is not None:
# Note: we count already running trials here otherwise we get
# (max_total_trials + number of workers) trials in total.
counted_states = [
TrialState.COMPLETE,
TrialState.RUNNING,
TrialState.PRUNED,
]
completed_trials = len(study.get_trials(states=counted_states))
if completed_trials < self.max_total_trials:
study.optimize(
self.objective,
n_jobs=self.n_jobs,
callbacks=[
MaxTrialsCallback(
self.max_total_trials,
states=counted_states,
)
],
)
else:
study.optimize(self.objective, n_jobs=self.n_jobs, n_trials=self.n_trials)
except KeyboardInterrupt:
pass
print("Number of finished trials: ", len(study.trials))
print("Best trial:")
trial = study.best_trial
print("Value: ", trial.value)
print("Params: ")
for key, value in trial.params.items():
print(f" {key}: {value}")
report_name = (
f"report_{self.env_name}_{self.n_trials}-trials-{self.n_timesteps}"
f"-{self.sampler}-{self.pruner}_{int(time.time())}"
)
log_path = os.path.join(self.log_folder, self.algo, report_name)
if self.verbose:
print(f"Writing report to {log_path}")
# Write report
os.makedirs(os.path.dirname(log_path), exist_ok=True)
study.trials_dataframe().to_csv(f"{log_path}.csv")
# Save python object to inspect/re-use it later
with open(f"{log_path}.pkl", "wb+") as f:
pkl.dump(study, f)
# Skip plots
if self.no_optim_plots:
return
# Plot optimization result
try:
fig1 = plot_optimization_history(study)
fig2 = plot_param_importances(study)
fig1.show()
fig2.show()
except (ValueError, ImportError, RuntimeError):
pass