stable-baselines3/stable_baselines3/td3/policies.py
2020-05-08 15:10:46 +02:00

281 lines
13 KiB
Python

from typing import Optional, List, Tuple, Callable, Union, Type, Any, Dict
import gym
import torch as th
import torch.nn as nn
from stable_baselines3.common.preprocessing import get_action_dim
from stable_baselines3.common.policies import (BasePolicy, register_policy, create_mlp,
NatureCNN, BaseFeaturesExtractor, FlattenExtractor)
class Actor(BasePolicy):
"""
Actor network (policy) for TD3.
:param observation_space: (gym.spaces.Space) Obervation space
:param action_space: (gym.spaces.Space) Action space
:param net_arch: ([int]) Network architecture
:param features_extractor: (nn.Module) Network to extract features
(a CNN when using images, a nn.Flatten() layer otherwise)
:param features_dim: (int) Number of features
:param activation_fn: (Type[nn.Module]) Activation function
:param normalize_images: (bool) Whether to normalize images or not,
dividing by 255.0 (True by default)
:param device: (Union[th.device, str]) Device on which the code should run.
"""
def __init__(self,
observation_space: gym.spaces.Space,
action_space: gym.spaces.Space,
net_arch: List[int],
features_extractor: nn.Module,
features_dim: int,
activation_fn: Type[nn.Module] = nn.ReLU,
normalize_images: bool = True,
device: Union[th.device, str] = 'auto'):
super(Actor, self).__init__(observation_space, action_space,
features_extractor=features_extractor,
normalize_images=normalize_images,
device=device,
squash_output=True)
self.features_extractor = features_extractor
self.normalize_images = normalize_images
self.net_arch = net_arch
self.features_dim = features_dim
self.activation_fn = activation_fn
action_dim = get_action_dim(self.action_space)
actor_net = create_mlp(features_dim, action_dim, net_arch, activation_fn, squash_output=True)
# Deterministic action
self.mu = nn.Sequential(*actor_net)
def _get_data(self) -> Dict[str, Any]:
data = super()._get_data()
data.update(dict(
net_arch=self.net_arch,
features_dim=self.features_dim,
activation_fn=self.activation_fn,
features_extractor=self.features_extractor
))
return data
def forward(self, obs: th.Tensor, deterministic: bool = True) -> th.Tensor:
# assert deterministic, 'The TD3 actor only outputs deterministic actions'
features = self.extract_features(obs)
return self.mu(features)
def _predict(self, observation: th.Tensor, deterministic: bool = False) -> th.Tensor:
return self.forward(observation, deterministic=deterministic)
class Critic(BasePolicy):
"""
Critic network for TD3,
in fact it represents the action-state value function (Q-value function)
:param observation_space: (gym.spaces.Space) Obervation space
:param action_space: (gym.spaces.Space) Action space
:param net_arch: ([int]) Network architecture
:param features_extractor: (nn.Module) Network to extract features
(a CNN when using images, a nn.Flatten() layer otherwise)
:param features_dim: (int) Number of features
:param activation_fn: (Type[nn.Module]) Activation function
:param normalize_images: (bool) Whether to normalize images or not,
dividing by 255.0 (True by default)
:param device: (Union[th.device, str]) Device on which the code should run.
"""
def __init__(self, observation_space: gym.spaces.Space,
action_space: gym.spaces.Space,
net_arch: List[int],
features_extractor: nn.Module,
features_dim: int,
activation_fn: Type[nn.Module] = nn.ReLU,
normalize_images: bool = True,
device: Union[th.device, str] = 'auto'):
super(Critic, self).__init__(observation_space, action_space,
features_extractor=features_extractor,
normalize_images=normalize_images,
device=device)
action_dim = get_action_dim(self.action_space)
q1_net = create_mlp(features_dim + action_dim, 1, net_arch, activation_fn)
self.q1_net = nn.Sequential(*q1_net)
q2_net = create_mlp(features_dim + action_dim, 1, net_arch, activation_fn)
self.q2_net = nn.Sequential(*q2_net)
def forward(self, obs: th.Tensor, actions: th.Tensor) -> Tuple[th.Tensor, th.Tensor]:
# Learn the features extractor using the policy loss only
with th.no_grad():
features = self.extract_features(obs)
qvalue_input = th.cat([features, actions], dim=1)
return self.q1_net(qvalue_input), self.q2_net(qvalue_input)
def q1_forward(self, obs: th.Tensor, actions: th.Tensor) -> th.Tensor:
with th.no_grad():
features = self.extract_features(obs)
return self.q1_net(th.cat([features, actions], dim=1))
class TD3Policy(BasePolicy):
"""
Policy class (with both actor and critic) for TD3.
:param observation_space: (gym.spaces.Space) Observation space
:param action_space: (gym.spaces.Space) Action space
:param lr_schedule: (Callable) Learning rate schedule (could be constant)
:param net_arch: (Optional[List[int]]) The specification of the policy and value networks.
:param device: (Union[th.device, str]) Device on which the code should run.
:param activation_fn: (Type[nn.Module]) Activation function
:param features_extractor_class: (Type[BaseFeaturesExtractor]) Features extractor to use.
:param features_extractor_kwargs: (Optional[Dict[str, Any]]) Keyword arguments
to pass to the feature extractor.
:param normalize_images: (bool) Whether to normalize images or not,
dividing by 255.0 (True by default)
:param optimizer_class: (Type[th.optim.Optimizer]) The optimizer to use,
``th.optim.Adam`` by default
:param optimizer_kwargs: (Optional[Dict[str, Any]]) Additional keyword arguments,
excluding the learning rate, to pass to the optimizer
"""
def __init__(self, observation_space: gym.spaces.Space,
action_space: gym.spaces.Space,
lr_schedule: Callable,
net_arch: Optional[List[int]] = None,
device: Union[th.device, str] = 'auto',
activation_fn: Type[nn.Module] = nn.ReLU,
features_extractor_class: Type[BaseFeaturesExtractor] = FlattenExtractor,
features_extractor_kwargs: Optional[Dict[str, Any]] = None,
normalize_images: bool = True,
optimizer_class: Type[th.optim.Optimizer] = th.optim.Adam,
optimizer_kwargs: Optional[Dict[str, Any]] = None):
super(TD3Policy, self).__init__(observation_space, action_space,
device,
features_extractor_class,
features_extractor_kwargs,
optimizer_class=optimizer_class,
optimizer_kwargs=optimizer_kwargs,
squash_output=True)
# Default network architecture, from the original paper
if net_arch is None:
if features_extractor_class == FlattenExtractor:
net_arch = [400, 300]
else:
net_arch = []
self.features_extractor = features_extractor_class(self.observation_space,
**self.features_extractor_kwargs)
self.features_dim = self.features_extractor.features_dim
self.net_arch = net_arch
self.activation_fn = activation_fn
self.net_args = {
'observation_space': self.observation_space,
'action_space': self.action_space,
'features_extractor': self.features_extractor,
'features_dim': self.features_dim,
'net_arch': self.net_arch,
'activation_fn': self.activation_fn,
'normalize_images': normalize_images,
'device': device
}
self.actor, self.actor_target = None, None
self.critic, self.critic_target = None, None
self._build(lr_schedule)
def _build(self, lr_schedule: Callable) -> None:
self.actor = self.make_actor()
self.actor_target = self.make_actor()
self.actor_target.load_state_dict(self.actor.state_dict())
self.actor.optimizer = self.optimizer_class(self.actor.parameters(), lr=lr_schedule(1),
**self.optimizer_kwargs)
self.critic = self.make_critic()
self.critic_target = self.make_critic()
self.critic_target.load_state_dict(self.critic.state_dict())
self.critic.optimizer = self.optimizer_class(self.critic.parameters(), lr=lr_schedule(1),
**self.optimizer_kwargs)
def _get_data(self) -> Dict[str, Any]:
data = super()._get_data()
data.update(dict(
net_arch=self.net_args['net_arch'],
activation_fn=self.net_args['activation_fn'],
lr_schedule=self._dummy_schedule, # dummy lr schedule, not needed for loading policy alone
optimizer_class=self.optimizer_class,
optimizer_kwargs=self.optimizer_kwargs,
features_extractor_class=self.features_extractor_class,
features_extractor_kwargs=self.features_extractor_kwargs
))
return data
def make_actor(self) -> Actor:
return Actor(**self.net_args).to(self.device)
def make_critic(self) -> Critic:
return Critic(**self.net_args).to(self.device)
def forward(self, observation: th.Tensor, deterministic: bool = False):
return self._predict(observation, deterministic=deterministic)
def _predict(self, observation: th.Tensor, deterministic: bool = False) -> th.Tensor:
return self.actor(observation, deterministic=deterministic)
MlpPolicy = TD3Policy
class CnnPolicy(TD3Policy):
"""
Policy class (with both actor and critic) for TD3.
:param observation_space: (gym.spaces.Space) Observation space
:param action_space: (gym.spaces.Space) Action space
:param lr_schedule: (Callable) Learning rate schedule (could be constant)
:param net_arch: (Optional[List[int]]) The specification of the policy and value networks.
:param device: (Union[th.device, str]) Device on which the code should run.
:param activation_fn: (Type[nn.Module]) Activation function
:param features_extractor_class: (Type[BaseFeaturesExtractor]) Features extractor to use.
:param features_extractor_kwargs: (Optional[Dict[str, Any]]) Keyword arguments
to pass to the feature extractor.
:param normalize_images: (bool) Whether to normalize images or not,
dividing by 255.0 (True by default)
:param optimizer_class: (Type[th.optim.Optimizer]) The optimizer to use,
``th.optim.Adam`` by default
:param optimizer_kwargs: (Optional[Dict[str, Any]]) Additional keyword arguments,
excluding the learning rate, to pass to the optimizer
"""
def __init__(self, observation_space: gym.spaces.Space,
action_space: gym.spaces.Space,
lr_schedule: Callable,
net_arch: Optional[List[int]] = None,
device: Union[th.device, str] = 'auto',
activation_fn: Type[nn.Module] = nn.ReLU,
features_extractor_class: Type[BaseFeaturesExtractor] = NatureCNN,
features_extractor_kwargs: Optional[Dict[str, Any]] = None,
normalize_images: bool = True,
optimizer_class: Type[th.optim.Optimizer] = th.optim.Adam,
optimizer_kwargs: Optional[Dict[str, Any]] = None):
super(CnnPolicy, self).__init__(observation_space,
action_space,
lr_schedule,
net_arch,
device,
activation_fn,
features_extractor_class,
features_extractor_kwargs,
normalize_images,
optimizer_class,
optimizer_kwargs)
register_policy("MlpPolicy", MlpPolicy)
register_policy("CnnPolicy", CnnPolicy)