Tianshou/tianshou/utils/net/continuous.py
Dominik Jain 17ef4dd5eb Support REDQ in high-level API
* Implement example mujoco_redq_hl
* Add abstraction CriticEnsembleFactory with default implementations
  to suit REDQ
* Fix type annotation of linear_layer in Net, MLP, Critic
  (was incompatible with REDQ usage)
2023-10-18 20:44:17 +02:00

506 lines
17 KiB
Python

import warnings
from collections.abc import Sequence
from typing import Any, cast
import numpy as np
import torch
from torch import nn
from tianshou.utils.net.common import MLP, BaseActor, TActionShape, TLinearLayer
SIGMA_MIN = -20
SIGMA_MAX = 2
class Actor(BaseActor):
"""Simple actor network.
It will create an actor operated in continuous action space with structure of preprocess_net ---> action_shape.
:param preprocess_net: a self-defined preprocess_net which output a
flattened hidden state.
:param action_shape: a sequence of int for the shape of action.
:param hidden_sizes: a sequence of int for constructing the MLP after
preprocess_net. Default to empty sequence (where the MLP now contains
only a single linear layer).
:param max_action: the scale for the final action logits. Default to
1.
:param preprocess_net_output_dim: the output dimension of
preprocess_net.
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
.. seealso::
Please refer to :class:`~tianshou.utils.net.common.Net` as an instance
of how preprocess_net is suggested to be defined.
"""
def __init__(
self,
preprocess_net: nn.Module,
action_shape: TActionShape,
hidden_sizes: Sequence[int] = (),
max_action: float = 1.0,
device: str | int | torch.device = "cpu",
preprocess_net_output_dim: int | None = None,
) -> None:
super().__init__()
self.device = device
self.preprocess = preprocess_net
self.output_dim = int(np.prod(action_shape))
input_dim = getattr(preprocess_net, "output_dim", preprocess_net_output_dim)
input_dim = cast(int, input_dim)
self.last = MLP(
input_dim,
self.output_dim,
hidden_sizes,
device=self.device,
)
self.max_action = max_action
def get_preprocess_net(self) -> nn.Module:
return self.preprocess
def forward(
self,
obs: np.ndarray | torch.Tensor,
state: Any = None,
info: dict[str, Any] | None = None,
) -> tuple[torch.Tensor, Any]:
"""Mapping: obs -> logits -> action."""
if info is None:
info = {}
logits, hidden = self.preprocess(obs, state)
logits = self.max_action * torch.tanh(self.last(logits))
return logits, hidden
class Critic(nn.Module):
"""Simple critic network.
It will create an actor operated in continuous action space with structure of preprocess_net ---> 1(q value).
:param preprocess_net: a self-defined preprocess_net which output a
flattened hidden state.
:param hidden_sizes: a sequence of int for constructing the MLP after
preprocess_net. Default to empty sequence (where the MLP now contains
only a single linear layer).
:param preprocess_net_output_dim: the output dimension of
preprocess_net.
:param linear_layer: use this module as linear layer. Default to nn.Linear.
:param flatten_input: whether to flatten input data for the last layer.
Default to True.
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
.. seealso::
Please refer to :class:`~tianshou.utils.net.common.Net` as an instance
of how preprocess_net is suggested to be defined.
"""
def __init__(
self,
preprocess_net: nn.Module,
hidden_sizes: Sequence[int] = (),
device: str | int | torch.device = "cpu",
preprocess_net_output_dim: int | None = None,
linear_layer: TLinearLayer = nn.Linear,
flatten_input: bool = True,
) -> None:
super().__init__()
self.device = device
self.preprocess = preprocess_net
self.output_dim = 1
input_dim = getattr(preprocess_net, "output_dim", preprocess_net_output_dim)
self.last = MLP(
input_dim, # type: ignore
1,
hidden_sizes,
device=self.device,
linear_layer=linear_layer,
flatten_input=flatten_input,
)
def forward(
self,
obs: np.ndarray | torch.Tensor,
act: np.ndarray | torch.Tensor | None = None,
info: dict[str, Any] | None = None,
) -> torch.Tensor:
"""Mapping: (s, a) -> logits -> Q(s, a)."""
if info is None:
info = {}
obs = torch.as_tensor(
obs,
device=self.device,
dtype=torch.float32,
).flatten(1)
if act is not None:
act = torch.as_tensor(
act,
device=self.device,
dtype=torch.float32,
).flatten(1)
obs = torch.cat([obs, act], dim=1)
logits, hidden = self.preprocess(obs)
return self.last(logits)
class ActorProb(BaseActor):
"""Simple actor network (output with a Gauss distribution).
:param preprocess_net: a self-defined preprocess_net which output a
flattened hidden state.
:param action_shape: a sequence of int for the shape of action.
:param hidden_sizes: a sequence of int for constructing the MLP after
preprocess_net. Default to empty sequence (where the MLP now contains
only a single linear layer).
:param max_action: the scale for the final action logits. Default to
1.
:param unbounded: whether to apply tanh activation on final logits.
Default to False.
:param conditioned_sigma: True when sigma is calculated from the
input, False when sigma is an independent parameter. Default to False.
:param preprocess_net_output_dim: the output dimension of
preprocess_net.
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
.. seealso::
Please refer to :class:`~tianshou.utils.net.common.Net` as an instance
of how preprocess_net is suggested to be defined.
"""
def __init__(
self,
preprocess_net: nn.Module,
action_shape: TActionShape,
hidden_sizes: Sequence[int] = (),
max_action: float = 1.0,
device: str | int | torch.device = "cpu",
unbounded: bool = False,
conditioned_sigma: bool = False,
preprocess_net_output_dim: int | None = None,
) -> None:
super().__init__()
if unbounded and not np.isclose(max_action, 1.0):
warnings.warn("Note that max_action input will be discarded when unbounded is True.")
max_action = 1.0
self.preprocess = preprocess_net
self.device = device
self.output_dim = int(np.prod(action_shape))
input_dim = getattr(preprocess_net, "output_dim", preprocess_net_output_dim)
self.mu = MLP(input_dim, self.output_dim, hidden_sizes, device=self.device) # type: ignore
self._c_sigma = conditioned_sigma
if conditioned_sigma:
self.sigma = MLP(
input_dim, # type: ignore
self.output_dim,
hidden_sizes,
device=self.device,
)
else:
self.sigma_param = nn.Parameter(torch.zeros(self.output_dim, 1))
self.max_action = max_action
self._unbounded = unbounded
def get_preprocess_net(self) -> nn.Module:
return self.preprocess
def forward(
self,
obs: np.ndarray | torch.Tensor,
state: Any = None,
info: dict[str, Any] | None = None,
) -> tuple[tuple[torch.Tensor, torch.Tensor], Any]:
"""Mapping: obs -> logits -> (mu, sigma)."""
if info is None:
info = {}
logits, hidden = self.preprocess(obs, state)
mu = self.mu(logits)
if not self._unbounded:
mu = self.max_action * torch.tanh(mu)
if self._c_sigma:
sigma = torch.clamp(self.sigma(logits), min=SIGMA_MIN, max=SIGMA_MAX).exp()
else:
shape = [1] * len(mu.shape)
shape[1] = -1
sigma = (self.sigma_param.view(shape) + torch.zeros_like(mu)).exp()
return (mu, sigma), state
class RecurrentActorProb(nn.Module):
"""Recurrent version of ActorProb.
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
"""
def __init__(
self,
layer_num: int,
state_shape: Sequence[int],
action_shape: Sequence[int],
hidden_layer_size: int = 128,
max_action: float = 1.0,
device: str | int | torch.device = "cpu",
unbounded: bool = False,
conditioned_sigma: bool = False,
) -> None:
super().__init__()
if unbounded and not np.isclose(max_action, 1.0):
warnings.warn("Note that max_action input will be discarded when unbounded is True.")
max_action = 1.0
self.device = device
self.nn = nn.LSTM(
input_size=int(np.prod(state_shape)),
hidden_size=hidden_layer_size,
num_layers=layer_num,
batch_first=True,
)
output_dim = int(np.prod(action_shape))
self.mu = nn.Linear(hidden_layer_size, output_dim)
self._c_sigma = conditioned_sigma
if conditioned_sigma:
self.sigma = nn.Linear(hidden_layer_size, output_dim)
else:
self.sigma_param = nn.Parameter(torch.zeros(output_dim, 1))
self.max_action = max_action
self._unbounded = unbounded
def forward(
self,
obs: np.ndarray | torch.Tensor,
state: dict[str, torch.Tensor] | None = None,
info: dict[str, Any] | None = None,
) -> tuple[tuple[torch.Tensor, torch.Tensor], dict[str, torch.Tensor]]:
"""Almost the same as :class:`~tianshou.utils.net.common.Recurrent`."""
if info is None:
info = {}
obs = torch.as_tensor(
obs,
device=self.device,
dtype=torch.float32,
)
# obs [bsz, len, dim] (training) or [bsz, dim] (evaluation)
# In short, the tensor's shape in training phase is longer than which
# in evaluation phase.
if len(obs.shape) == 2:
obs = obs.unsqueeze(-2)
self.nn.flatten_parameters()
if state is None:
obs, (hidden, cell) = self.nn(obs)
else:
# we store the stack data in [bsz, len, ...] format
# but pytorch rnn needs [len, bsz, ...]
obs, (hidden, cell) = self.nn(
obs,
(
state["hidden"].transpose(0, 1).contiguous(),
state["cell"].transpose(0, 1).contiguous(),
),
)
logits = obs[:, -1]
mu = self.mu(logits)
if not self._unbounded:
mu = self.max_action * torch.tanh(mu)
if self._c_sigma:
sigma = torch.clamp(self.sigma(logits), min=SIGMA_MIN, max=SIGMA_MAX).exp()
else:
shape = [1] * len(mu.shape)
shape[1] = -1
sigma = (self.sigma_param.view(shape) + torch.zeros_like(mu)).exp()
# please ensure the first dim is batch size: [bsz, len, ...]
return (mu, sigma), {
"hidden": hidden.transpose(0, 1).detach(),
"cell": cell.transpose(0, 1).detach(),
}
class RecurrentCritic(nn.Module):
"""Recurrent version of Critic.
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
"""
def __init__(
self,
layer_num: int,
state_shape: Sequence[int],
action_shape: Sequence[int] = [0],
device: str | int | torch.device = "cpu",
hidden_layer_size: int = 128,
) -> None:
super().__init__()
self.state_shape = state_shape
self.action_shape = action_shape
self.device = device
self.nn = nn.LSTM(
input_size=int(np.prod(state_shape)),
hidden_size=hidden_layer_size,
num_layers=layer_num,
batch_first=True,
)
self.fc2 = nn.Linear(hidden_layer_size + int(np.prod(action_shape)), 1)
def forward(
self,
obs: np.ndarray | torch.Tensor,
act: np.ndarray | torch.Tensor | None = None,
info: dict[str, Any] | None = None,
) -> torch.Tensor:
"""Almost the same as :class:`~tianshou.utils.net.common.Recurrent`."""
if info is None:
info = {}
obs = torch.as_tensor(
obs,
device=self.device,
dtype=torch.float32,
)
# obs [bsz, len, dim] (training) or [bsz, dim] (evaluation)
# In short, the tensor's shape in training phase is longer than which
# in evaluation phase.
assert len(obs.shape) == 3
self.nn.flatten_parameters()
obs, (hidden, cell) = self.nn(obs)
obs = obs[:, -1]
if act is not None:
act = torch.as_tensor(
act,
device=self.device,
dtype=torch.float32,
)
obs = torch.cat([obs, act], dim=1)
return self.fc2(obs)
class Perturbation(nn.Module):
"""Implementation of perturbation network in BCQ algorithm.
Given a state and action, it can generate perturbed action.
:param preprocess_net: a self-defined preprocess_net which output a
flattened hidden state.
:param max_action: the maximum value of each dimension of action.
:param device: which device to create this model on.
Default to cpu.
:param phi: max perturbation parameter for BCQ. Default to 0.05.
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
.. seealso::
You can refer to `examples/offline/offline_bcq.py` to see how to use it.
"""
def __init__(
self,
preprocess_net: nn.Module,
max_action: float,
device: str | int | torch.device = "cpu",
phi: float = 0.05,
):
# preprocess_net: input_dim=state_dim+action_dim, output_dim=action_dim
super().__init__()
self.preprocess_net = preprocess_net
self.device = device
self.max_action = max_action
self.phi = phi
def forward(self, state: torch.Tensor, action: torch.Tensor) -> torch.Tensor:
# preprocess_net
logits = self.preprocess_net(torch.cat([state, action], -1))[0]
noise = self.phi * self.max_action * torch.tanh(logits)
# clip to [-max_action, max_action]
return (noise + action).clamp(-self.max_action, self.max_action)
class VAE(nn.Module):
"""Implementation of VAE.
It models the distribution of action. Given a state, it can generate actions similar to those in batch.
It is used in BCQ algorithm.
:param encoder: the encoder in VAE. Its input_dim must be
state_dim + action_dim, and output_dim must be hidden_dim.
:param decoder: the decoder in VAE. Its input_dim must be
state_dim + latent_dim, and output_dim must be action_dim.
:param hidden_dim: the size of the last linear-layer in encoder.
:param latent_dim: the size of latent layer.
:param max_action: the maximum value of each dimension of action.
:param device: which device to create this model on.
Default to "cpu".
For advanced usage (how to customize the network), please refer to
:ref:`build_the_network`.
.. seealso::
You can refer to `examples/offline/offline_bcq.py` to see how to use it.
"""
def __init__(
self,
encoder: nn.Module,
decoder: nn.Module,
hidden_dim: int,
latent_dim: int,
max_action: float,
device: str | torch.device = "cpu",
):
super().__init__()
self.encoder = encoder
self.mean = nn.Linear(hidden_dim, latent_dim)
self.log_std = nn.Linear(hidden_dim, latent_dim)
self.decoder = decoder
self.max_action = max_action
self.latent_dim = latent_dim
self.device = device
def forward(
self,
state: torch.Tensor,
action: torch.Tensor,
) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
# [state, action] -> z , [state, z] -> action
latent_z = self.encoder(torch.cat([state, action], -1))
# shape of z: (state.shape[:-1], hidden_dim)
mean = self.mean(latent_z)
# Clamped for numerical stability
log_std = self.log_std(latent_z).clamp(-4, 15)
std = torch.exp(log_std)
# shape of mean, std: (state.shape[:-1], latent_dim)
latent_z = mean + std * torch.randn_like(std) # (state.shape[:-1], latent_dim)
reconstruction = self.decode(state, latent_z) # (state.shape[:-1], action_dim)
return reconstruction, mean, std
def decode(
self,
state: torch.Tensor,
latent_z: torch.Tensor | None = None,
) -> torch.Tensor:
# decode(state) -> action
if latent_z is None:
# state.shape[0] may be batch_size
# latent vector clipped to [-0.5, 0.5]
latent_z = (
torch.randn(state.shape[:-1] + (self.latent_dim,)).to(self.device).clamp(-0.5, 0.5)
)
# decode z with state!
return self.max_action * torch.tanh(self.decoder(torch.cat([state, latent_z], -1)))