136 lines
4.6 KiB
Python
136 lines
4.6 KiB
Python
import argparse
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import os
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import pprint
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import gym
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import numpy as np
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import torch
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from torch.utils.tensorboard import SummaryWriter
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from tianshou.data import Collector, VectorReplayBuffer
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from tianshou.env import DummyVectorEnv
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from tianshou.policy import PGPolicy
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from tianshou.trainer import onpolicy_trainer
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from tianshou.utils import TensorboardLogger
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from tianshou.utils.net.common import Net
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def get_args():
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parser = argparse.ArgumentParser()
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parser.add_argument('--task', type=str, default='CartPole-v0')
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parser.add_argument('--reward-threshold', type=float, default=None)
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parser.add_argument('--seed', type=int, default=1)
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parser.add_argument('--buffer-size', type=int, default=20000)
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parser.add_argument('--lr', type=float, default=1e-3)
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parser.add_argument('--gamma', type=float, default=0.95)
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parser.add_argument('--epoch', type=int, default=10)
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parser.add_argument('--step-per-epoch', type=int, default=40000)
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parser.add_argument('--episode-per-collect', type=int, default=8)
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parser.add_argument('--repeat-per-collect', type=int, default=2)
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parser.add_argument('--batch-size', type=int, default=64)
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parser.add_argument('--hidden-sizes', type=int, nargs='*', default=[64, 64])
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parser.add_argument('--training-num', type=int, default=8)
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parser.add_argument('--test-num', type=int, default=100)
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parser.add_argument('--logdir', type=str, default='log')
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parser.add_argument('--render', type=float, default=0.)
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parser.add_argument('--rew-norm', type=int, default=1)
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parser.add_argument(
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'--device', type=str, default='cuda' if torch.cuda.is_available() else 'cpu'
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)
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args = parser.parse_known_args()[0]
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return args
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def test_pg(args=get_args()):
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env = gym.make(args.task)
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args.state_shape = env.observation_space.shape or env.observation_space.n
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args.action_shape = env.action_space.shape or env.action_space.n
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if args.reward_threshold is None:
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default_reward_threshold = {"CartPole-v0": 195}
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args.reward_threshold = default_reward_threshold.get(
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args.task, env.spec.reward_threshold
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)
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# train_envs = gym.make(args.task)
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# you can also use tianshou.env.SubprocVectorEnv
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train_envs = DummyVectorEnv(
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[lambda: gym.make(args.task) for _ in range(args.training_num)]
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)
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# test_envs = gym.make(args.task)
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test_envs = DummyVectorEnv(
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[lambda: gym.make(args.task) for _ in range(args.test_num)]
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)
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# seed
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np.random.seed(args.seed)
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torch.manual_seed(args.seed)
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train_envs.seed(args.seed)
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test_envs.seed(args.seed)
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# model
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net = Net(
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args.state_shape,
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args.action_shape,
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hidden_sizes=args.hidden_sizes,
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device=args.device,
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softmax=True
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).to(args.device)
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optim = torch.optim.Adam(net.parameters(), lr=args.lr)
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dist = torch.distributions.Categorical
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policy = PGPolicy(
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net,
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optim,
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dist,
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args.gamma,
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reward_normalization=args.rew_norm,
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action_space=env.action_space
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)
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for m in net.modules():
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if isinstance(m, torch.nn.Linear):
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# orthogonal initialization
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torch.nn.init.orthogonal_(m.weight, gain=np.sqrt(2))
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torch.nn.init.zeros_(m.bias)
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# collector
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train_collector = Collector(
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policy, train_envs, VectorReplayBuffer(args.buffer_size, len(train_envs))
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)
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test_collector = Collector(policy, test_envs)
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# log
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log_path = os.path.join(args.logdir, args.task, 'pg')
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writer = SummaryWriter(log_path)
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logger = TensorboardLogger(writer)
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def save_best_fn(policy):
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torch.save(policy.state_dict(), os.path.join(log_path, 'policy.pth'))
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def stop_fn(mean_rewards):
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return mean_rewards >= args.reward_threshold
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# trainer
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result = onpolicy_trainer(
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policy,
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train_collector,
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test_collector,
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args.epoch,
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args.step_per_epoch,
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args.repeat_per_collect,
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args.test_num,
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args.batch_size,
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episode_per_collect=args.episode_per_collect,
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stop_fn=stop_fn,
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save_best_fn=save_best_fn,
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logger=logger
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)
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assert stop_fn(result['best_reward'])
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if __name__ == '__main__':
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pprint.pprint(result)
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# Let's watch its performance!
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env = gym.make(args.task)
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policy.eval()
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collector = Collector(policy, env)
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result = collector.collect(n_episode=1, render=args.render)
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rews, lens = result["rews"], result["lens"]
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print(f"Final reward: {rews.mean()}, length: {lens.mean()}")
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if __name__ == '__main__':
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test_pg()
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