ctm-dqn/agents/td3_agent.py

125 lines
4.0 KiB
Python

"""
TD3 Agent using Stable-Baselines3
Adapted for MultiDiscrete VSL control.
"""
import numpy as np
import torch
from stable_baselines3 import TD3
from stable_baselines3.common.noise import NormalActionNoise
import gymnasium as gym
from gymnasium import spaces
class MultiDiscreteWrapper(gym.Env):
"""Wrap a MultiDiscrete action space as a continuous Box for TD3."""
def __init__(self, state_dim, action_dims):
super().__init__()
self.state_dim = state_dim
self.action_dims = action_dims
self.num_zones = len(action_dims)
self.observation_space = spaces.Box(
low=-np.inf, high=np.inf, shape=(state_dim,), dtype=np.float32
)
self.action_space = spaces.Box(
low=0.0, high=1.0, shape=(self.num_zones,), dtype=np.float32
)
def reset(self, seed=None, options=None):
return np.zeros(self.state_dim, dtype=np.float32), {}
def step(self, action):
return np.zeros(self.state_dim, dtype=np.float32), 0.0, False, False, {}
class TD3Agent:
"""TD3 agent wrapper."""
def __init__(
self,
state_dim: int,
action_dims: list,
learning_rate: float = 3e-4,
buffer_size: int = 100000,
learning_starts: int = 100,
batch_size: int = 64,
tau: float = 0.005,
gamma: float = 0.99,
policy_delay: int = 2,
exploration_sigma: float = 0.1,
device: str = "cuda",
):
self.state_dim = state_dim
self.action_dims = action_dims
self.num_zones = len(action_dims)
self.device = device
self.learning_starts = learning_starts
self.total_steps = 0
self.exploration_sigma = exploration_sigma
dummy_env = MultiDiscreteWrapper(state_dim, action_dims)
action_noise = NormalActionNoise(
mean=np.zeros(self.num_zones),
sigma=0.1 * np.ones(self.num_zones),
)
self.model = TD3(
"MlpPolicy",
env=dummy_env,
learning_rate=learning_rate,
buffer_size=buffer_size,
learning_starts=learning_starts,
batch_size=batch_size,
tau=tau,
gamma=gamma,
policy_delay=policy_delay,
action_noise=action_noise,
device=device,
verbose=0,
)
def select_action(self, state: np.ndarray, deterministic: bool = False):
if not deterministic and self.total_steps < self.learning_starts:
discrete_action = np.array(
[np.random.randint(self.action_dims[i]) for i in range(self.num_zones)],
dtype=np.int64,
)
return discrete_action, 0.0, 0.0
continuous_action, _ = self.model.predict(state, deterministic=deterministic)
if not deterministic:
noise = np.random.normal(0.0, self.exploration_sigma, size=self.num_zones)
continuous_action = np.clip(continuous_action + noise, 0.0, 1.0)
discrete_action = np.array(
[int(cont * (self.action_dims[i] - 1) + 0.5) for i, cont in enumerate(continuous_action)]
)
discrete_action = np.clip(discrete_action, 0, [d - 1 for d in self.action_dims])
return discrete_action, 0.0, 0.0
def store_transition(self, state, action, reward, next_state, done):
self.total_steps += 1
continuous_action = np.array(
[action[i] / (self.action_dims[i] - 1) for i in range(self.num_zones)],
dtype=np.float32,
)
self.model.replay_buffer.add(
state, next_state, continuous_action, reward, done, [{}]
)
def update(self):
if self.model.replay_buffer.size() < self.model.batch_size:
return {}
self.model.learn(total_timesteps=1, reset_num_timesteps=False, log_interval=None)
return {"actor_loss": 0.0, "critic_loss": 0.0}
def save(self, path: str):
self.model.save(path)
def load(self, path: str):
self.model = TD3.load(path, device=self.device)