stable-baselines3/stable_baselines3/ddpg/ddpg.py

from typing import Any, Dict, Optional, Tuple, Type, TypeVar, Union

import torch as th

from stable_baselines3.common.buffers import ReplayBuffer
from stable_baselines3.common.noise import ActionNoise
from stable_baselines3.common.type_aliases import GymEnv, MaybeCallback, Schedule
from stable_baselines3.td3.policies import TD3Policy
from stable_baselines3.td3.td3 import TD3

DDPGSelf = TypeVar("DDPGSelf", bound="DDPG")


class DDPG(TD3):
    """
    Deep Deterministic Policy Gradient (DDPG).

    Deterministic Policy Gradient: http://proceedings.mlr.press/v32/silver14.pdf
    DDPG Paper: https://arxiv.org/abs/1509.02971
    Introduction to DDPG: https://spinningup.openai.com/en/latest/algorithms/ddpg.html

    Note: we treat DDPG as a special case of its successor TD3.

    :param policy: The policy model to use (MlpPolicy, CnnPolicy, ...)
    :param env: The environment to learn from (if registered in Gym, can be str)
    :param learning_rate: learning rate for adam optimizer,
        the same learning rate will be used for all networks (Q-Values, Actor and Value function)
        it can be a function of the current progress remaining (from 1 to 0)
    :param buffer_size: size of the replay buffer
    :param learning_starts: how many steps of the model to collect transitions for before learning starts
    :param batch_size: Minibatch size for each gradient update
    :param tau: the soft update coefficient ("Polyak update", between 0 and 1)
    :param gamma: the discount factor
    :param train_freq: Update the model every ``train_freq`` steps. Alternatively pass a tuple of frequency and unit
        like ``(5, "step")`` or ``(2, "episode")``.
    :param gradient_steps: How many gradient steps to do after each rollout (see ``train_freq``)
        Set to ``-1`` means to do as many gradient steps as steps done in the environment
        during the rollout.
    :param action_noise: the action noise type (None by default), this can help
        for hard exploration problem. Cf common.noise for the different action noise type.
    :param replay_buffer_class: Replay buffer class to use (for instance ``HerReplayBuffer``).
        If ``None``, it will be automatically selected.
    :param replay_buffer_kwargs: Keyword arguments to pass to the replay buffer on creation.
    :param optimize_memory_usage: Enable a memory efficient variant of the replay buffer
        at a cost of more complexity.
        See https://github.com/DLR-RM/stable-baselines3/issues/37#issuecomment-637501195
    :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).
        Caution, this parameter is deprecated and will be removed in the future.
        Please use `EvalCallback` or a custom Callback instead.
    :param policy_kwargs: additional arguments to be passed to the policy on creation
    :param verbose: Verbosity level: 0 for no output, 1 for info messages (such as device or wrappers used), 2 for
        debug messages
    :param seed: Seed for the pseudo random generators
    :param device: Device (cpu, cuda, ...) on which the code should be run.
        Setting it to auto, the code will be run on the GPU if possible.
    :param _init_setup_model: Whether or not to build the network at the creation of the instance
    """

    def __init__(
        self,
        policy: Union[str, Type[TD3Policy]],
        env: Union[GymEnv, str],
        learning_rate: Union[float, Schedule] = 1e-3,
        buffer_size: int = 1_000_000,  # 1e6
        learning_starts: int = 100,
        batch_size: int = 100,
        tau: float = 0.005,
        gamma: float = 0.99,
        train_freq: Union[int, Tuple[int, str]] = (1, "episode"),
        gradient_steps: int = -1,
        action_noise: Optional[ActionNoise] = None,
        replay_buffer_class: Optional[Type[ReplayBuffer]] = None,
        replay_buffer_kwargs: Optional[Dict[str, Any]] = None,
        optimize_memory_usage: bool = False,
        tensorboard_log: Optional[str] = None,
        create_eval_env: bool = False,
        policy_kwargs: Optional[Dict[str, Any]] = None,
        verbose: int = 0,
        seed: Optional[int] = None,
        device: Union[th.device, str] = "auto",
        _init_setup_model: bool = True,
    ):

        super().__init__(
            policy=policy,
            env=env,
            learning_rate=learning_rate,
            buffer_size=buffer_size,
            learning_starts=learning_starts,
            batch_size=batch_size,
            tau=tau,
            gamma=gamma,
            train_freq=train_freq,
            gradient_steps=gradient_steps,
            action_noise=action_noise,
            replay_buffer_class=replay_buffer_class,
            replay_buffer_kwargs=replay_buffer_kwargs,
            policy_kwargs=policy_kwargs,
            tensorboard_log=tensorboard_log,
            verbose=verbose,
            device=device,
            create_eval_env=create_eval_env,
            seed=seed,
            optimize_memory_usage=optimize_memory_usage,
            # Remove all tricks from TD3 to obtain DDPG:
            # we still need to specify target_policy_noise > 0 to avoid errors
            policy_delay=1,
            target_noise_clip=0.0,
            target_policy_noise=0.1,
            _init_setup_model=False,
        )

        # Use only one critic
        if "n_critics" not in self.policy_kwargs:
            self.policy_kwargs["n_critics"] = 1

        if _init_setup_model:
            self._setup_model()

    def learn(
        self: DDPGSelf,
        total_timesteps: int,
        callback: MaybeCallback = None,
        log_interval: int = 4,
        eval_env: Optional[GymEnv] = None,
        eval_freq: int = -1,
        n_eval_episodes: int = 5,
        tb_log_name: str = "DDPG",
        eval_log_path: Optional[str] = None,
        reset_num_timesteps: bool = True,
        progress_bar: bool = False,
    ) -> DDPGSelf:

        return super().learn(
            total_timesteps=total_timesteps,
            callback=callback,
            log_interval=log_interval,
            eval_env=eval_env,
            eval_freq=eval_freq,
            n_eval_episodes=n_eval_episodes,
            tb_log_name=tb_log_name,
            eval_log_path=eval_log_path,
            reset_num_timesteps=reset_num_timesteps,
            progress_bar=progress_bar,
        )