add accelerate example

cleanrl/ppo_atari_accelerate.py

@@ -0,0 +1,375 @@
+# docs and experiment results can be found at https://docs.cleanrl.dev/rl-algorithms/ppo/#ppo_ataripy
+import os
+import random
+import time
+from dataclasses import dataclass
+
+import gymnasium as gym
+import numpy as np
+import torch
+import torch.nn as nn
+import torch.optim as optim
+import tyro
+from torch.distributions.categorical import Categorical
+from torch.utils.tensorboard import SummaryWriter
+
+from stable_baselines3.common.atari_wrappers import (  # isort:skip
+    ClipRewardEnv,
+    EpisodicLifeEnv,
+    FireResetEnv,
+    MaxAndSkipEnv,
+    NoopResetEnv,
+)
+
+from accelerate import Accelerator
+
+
+@dataclass
+class Args:
+    exp_name: str = os.path.basename(__file__)[: -len(".py")]
+    """the name of this experiment"""
+    seed: int = 1
+    """seed of the experiment"""
+    torch_deterministic: bool = True
+    """if toggled, `torch.backends.cudnn.deterministic=False`"""
+    cuda: bool = True
+    """if toggled, cuda will be enabled by default"""
+    track: bool = False
+    """if toggled, this experiment will be tracked with Weights and Biases"""
+    wandb_project_name: str = "cleanRL"
+    """the wandb's project name"""
+    wandb_entity: str = None
+    """the entity (team) of wandb's project"""
+    capture_video: bool = False
+    """whether to capture videos of the agent performances (check out `videos` folder)"""
+
+    # Algorithm specific arguments
+    env_id: str = "BreakoutNoFrameskip-v4"
+    """the id of the environment"""
+    total_timesteps: int = 10000000
+    """total timesteps of the experiments"""
+    learning_rate: float = 2.5e-4
+    """the learning rate of the optimizer"""
+    local_num_envs: int = 8
+    """the number of parallel game environments (in the local rank)"""
+    num_steps: int = 128
+    """the number of steps to run in each environment per policy rollout"""
+    anneal_lr: bool = True
+    """Toggle learning rate annealing for policy and value networks"""
+    gamma: float = 0.99
+    """the discount factor gamma"""
+    gae_lambda: float = 0.95
+    """the lambda for the general advantage estimation"""
+    num_minibatches: int = 4
+    """the number of mini-batches"""
+    update_epochs: int = 4
+    """the K epochs to update the policy"""
+    norm_adv: bool = True
+    """Toggles advantages normalization"""
+    clip_coef: float = 0.1
+    """the surrogate clipping coefficient"""
+    clip_vloss: bool = True
+    """Toggles whether or not to use a clipped loss for the value function, as per the paper."""
+    ent_coef: float = 0.01
+    """coefficient of the entropy"""
+    vf_coef: float = 0.5
+    """coefficient of the value function"""
+    max_grad_norm: float = 0.5
+    """the maximum norm for the gradient clipping"""
+    target_kl: float = None
+    """the target KL divergence threshold"""
+
+    # to be filled in runtime
+    local_batch_size: int = 0
+    """the local batch size in the local rank (computed in runtime)"""
+    local_minibatch_size: int = 0
+    """the local mini-batch size in the local rank (computed in runtime)"""
+    num_envs: int = 0
+    """the number of parallel game environments (computed in runtime)"""
+    batch_size: int = 0
+    """the batch size (computed in runtime)"""
+    minibatch_size: int = 0
+    """the mini-batch size (computed in runtime)"""
+    num_iterations: int = 0
+    """the number of iterations (computed in runtime)"""
+    world_size: int = 0
+    """the number of processes (computed in runtime)"""
+
+
+def make_env(env_id, idx, capture_video, run_name):
+    def thunk():
+        if capture_video and idx == 0:
+            env = gym.make(env_id, render_mode="rgb_array")
+            env = gym.wrappers.RecordVideo(env, f"videos/{run_name}")
+        else:
+            env = gym.make(env_id)
+        env = gym.wrappers.RecordEpisodeStatistics(env)
+        if capture_video:
+            if idx == 0:
+                env = gym.wrappers.RecordVideo(env, f"videos/{run_name}")
+        env = NoopResetEnv(env, noop_max=30)
+        env = MaxAndSkipEnv(env, skip=4)
+        env = EpisodicLifeEnv(env)
+        if "FIRE" in env.unwrapped.get_action_meanings():
+            env = FireResetEnv(env)
+        env = ClipRewardEnv(env)
+        env = gym.wrappers.ResizeObservation(env, (84, 84))
+        env = gym.wrappers.GrayScaleObservation(env)
+        env = gym.wrappers.FrameStack(env, 4)
+        return env
+
+    return thunk
+
+
+def layer_init(layer, std=np.sqrt(2), bias_const=0.0):
+    torch.nn.init.orthogonal_(layer.weight, std)
+    torch.nn.init.constant_(layer.bias, bias_const)
+    return layer
+
+
+class Agent(nn.Module):
+    def __init__(self, envs):
+        super().__init__()
+        self.network = nn.Sequential(
+            layer_init(nn.Conv2d(4, 32, 8, stride=4)),
+            nn.ReLU(),
+            layer_init(nn.Conv2d(32, 64, 4, stride=2)),
+            nn.ReLU(),
+            layer_init(nn.Conv2d(64, 64, 3, stride=1)),
+            nn.ReLU(),
+            nn.Flatten(),
+            layer_init(nn.Linear(64 * 7 * 7, 512)),
+            nn.ReLU(),
+        )
+        self.actor = layer_init(nn.Linear(512, envs.single_action_space.n), std=0.01)
+        self.critic = layer_init(nn.Linear(512, 1), std=1)
+
+    def get_value(self, x):
+        return self.critic(self.network(x / 255.0))
+
+    def get_action_and_value(self, x, action=None):
+        hidden = self.network(x / 255.0)
+        logits = self.actor(hidden)
+        probs = Categorical(logits=logits)
+        if action is None:
+            action = probs.sample()
+        return action, probs.log_prob(action), probs.entropy(), self.critic(hidden)
+
+    # required due to how DistributedDataParallel wraps the model
+    def forward(self, x, action):
+        return self.get_action_and_value(x, action)
+
+def main():
+    args = tyro.cli(Args)
+    accelerator = Accelerator()
+    local_rank = accelerator.process_index
+    args.world_size = accelerator.num_processes
+    args.local_batch_size = int(args.local_num_envs * args.num_steps)
+    args.local_minibatch_size = int(args.local_batch_size // args.num_minibatches)
+    args.num_envs = args.local_num_envs * args.world_size
+    args.batch_size = int(args.num_envs * args.num_steps)
+    args.minibatch_size = int(args.batch_size // args.num_minibatches)
+    args.num_iterations = args.total_timesteps // args.batch_size
+    run_name = f"{args.env_id}__{args.exp_name}__{args.seed}__{int(time.time())}"
+
+
+    if args.track and accelerator.is_main_process:
+        import wandb
+
+        wandb.init(
+            project=args.wandb_project_name,
+            entity=args.wandb_entity,
+            sync_tensorboard=True,
+            config=vars(args),
+            name=run_name,
+            monitor_gym=True,
+            save_code=True,
+        )
+        writer = SummaryWriter(f"runs/{run_name}")
+        writer.add_text(
+            "hyperparameters",
+            "|param|value|\n|-|-|\n%s" % ("\n".join([f"|{key}|{value}|" for key, value in vars(args).items()])),
+        )
+
+    # TRY NOT TO MODIFY: seeding
+    # CRUCIAL: note that we needed to pass a different seed for each data parallelism worker
+    args.seed += accelerator.process_index * 100003  # Prime
+    random.seed(args.seed)
+    np.random.seed(args.seed)
+    torch.manual_seed(args.seed - local_rank)
+    torch.backends.cudnn.deterministic = args.torch_deterministic
+
+    # env setup
+    envs = gym.vector.SyncVectorEnv(
+        [make_env(args.env_id, i, args.capture_video, run_name) for i in range(args.local_num_envs)],
+    )
+    assert isinstance(envs.single_action_space, gym.spaces.Discrete), "only discrete action space is supported"
+
+    device = accelerator.device
+    agent = Agent(envs).to(device)
+    torch.manual_seed(args.seed)
+    optimizer = optim.Adam(agent.parameters(), lr=args.learning_rate, eps=1e-5)
+    agent, optimizer = accelerator.prepare(agent, optimizer)
+
+
+    # ALGO Logic: Storage setup
+    obs = torch.zeros((args.num_steps, args.local_num_envs) + envs.single_observation_space.shape).to(device)
+    actions = torch.zeros((args.num_steps, args.local_num_envs) + envs.single_action_space.shape).to(device)
+    logprobs = torch.zeros((args.num_steps, args.local_num_envs)).to(device)
+    rewards = torch.zeros((args.num_steps, args.local_num_envs)).to(device)
+    dones = torch.zeros((args.num_steps, args.local_num_envs)).to(device)
+    values = torch.zeros((args.num_steps, args.local_num_envs)).to(device)
+
+    # TRY NOT TO MODIFY: start the game
+    global_step = 0
+    start_time = time.time()
+    next_obs, _ = envs.reset(seed=args.seed)
+    next_obs = torch.Tensor(next_obs).to(device)
+    next_done = torch.zeros(args.local_num_envs).to(device)
+
+    for iteration in range(1, args.num_iterations + 1):
+        # Annealing the rate if instructed to do so.
+        if args.anneal_lr:
+            frac = 1.0 - (iteration - 1.0) / args.num_iterations
+            lrnow = frac * args.learning_rate
+            optimizer.param_groups[0]["lr"] = lrnow
+
+        for step in range(0, args.num_steps):
+            global_step += args.num_envs
+            obs[step] = next_obs
+            dones[step] = next_done
+
+            # ALGO LOGIC: action logic
+            with torch.no_grad():
+                action, logprob, _, value = accelerator.unwrap_model(agent).get_action_and_value(next_obs)
+                values[step] = value.flatten()
+            actions[step] = action
+            logprobs[step] = logprob
+
+            # TRY NOT TO MODIFY: execute the game and log data.
+            next_obs, reward, terminations, truncations, infos = envs.step(action.cpu().numpy())
+            next_done = np.logical_or(terminations, truncations)
+            rewards[step] = torch.tensor(reward).to(device).view(-1)
+            next_obs, next_done = torch.Tensor(next_obs).to(device), torch.Tensor(next_done).to(device)
+
+            if not (args.track and accelerator.is_main_process):
+                continue
+
+            if "final_info" in infos:
+                for info in infos["final_info"]:
+                    if info and "episode" in info:
+                        print(f"global_step={global_step}, episodic_return={info['episode']['r']}")
+                        writer.add_scalar("charts/episodic_return", info["episode"]["r"], global_step)
+                        writer.add_scalar("charts/episodic_length", info["episode"]["l"], global_step)
+
+        print(
+            f"local_rank: {local_rank}, action.sum(): {action.sum()}, iteration: {iteration}, agent.actor.weight.sum(): {accelerator.unwrap_model(agent).actor.weight.sum()}"
+        )
+        # bootstrap value if not done
+        with torch.no_grad():
+            next_value = accelerator.unwrap_model(agent).get_value(next_obs).reshape(1, -1)
+            advantages = torch.zeros_like(rewards).to(device)
+            lastgaelam = 0
+            for t in reversed(range(args.num_steps)):
+                if t == args.num_steps - 1:
+                    nextnonterminal = 1.0 - next_done
+                    nextvalues = next_value
+                else:
+                    nextnonterminal = 1.0 - dones[t + 1]
+                    nextvalues = values[t + 1]
+                delta = rewards[t] + args.gamma * nextvalues * nextnonterminal - values[t]
+                advantages[t] = lastgaelam = delta + args.gamma * args.gae_lambda * nextnonterminal * lastgaelam
+            returns = advantages + values
+
+        # flatten the batch
+        b_obs = obs.reshape((-1,) + envs.single_observation_space.shape)
+        b_logprobs = logprobs.reshape(-1)
+        b_actions = actions.reshape((-1,) + envs.single_action_space.shape)
+        b_advantages = advantages.reshape(-1)
+        b_returns = returns.reshape(-1)
+        b_values = values.reshape(-1)
+
+        # Optimizing the policy and value network
+        b_inds = np.arange(args.local_batch_size)
+        clipfracs = []
+        for epoch in range(args.update_epochs):
+            np.random.shuffle(b_inds)
+            for start in range(0, args.local_batch_size, args.local_minibatch_size):
+                end = start + args.local_minibatch_size
+                mb_inds = b_inds[start:end]
+
+                _, newlogprob, entropy, newvalue = agent(b_obs[mb_inds], b_actions.long()[mb_inds])
+                logratio = newlogprob - b_logprobs[mb_inds]
+                ratio = logratio.exp()
+
+                with torch.no_grad():
+                    # calculate approx_kl http://joschu.net/blog/kl-approx.html
+                    old_approx_kl = (-logratio).mean()
+                    approx_kl = ((ratio - 1) - logratio).mean()
+                    clipfracs += [((ratio - 1.0).abs() > args.clip_coef).float().mean().item()]
+
+                mb_advantages = b_advantages[mb_inds]
+                if args.norm_adv:
+                    mb_advantages = (mb_advantages - mb_advantages.mean()) / (mb_advantages.std() + 1e-8)
+
+                # Policy loss
+                pg_loss1 = -mb_advantages * ratio
+                pg_loss2 = -mb_advantages * torch.clamp(ratio, 1 - args.clip_coef, 1 + args.clip_coef)
+                pg_loss = torch.max(pg_loss1, pg_loss2).mean()
+
+                # Value loss
+                newvalue = newvalue.view(-1)
+                if args.clip_vloss:
+                    v_loss_unclipped = (newvalue - b_returns[mb_inds]) ** 2
+                    v_clipped = b_values[mb_inds] + torch.clamp(
+                        newvalue - b_values[mb_inds],
+                        -args.clip_coef,
+                        args.clip_coef,
+                    )
+                    v_loss_clipped = (v_clipped - b_returns[mb_inds]) ** 2
+                    v_loss_max = torch.max(v_loss_unclipped, v_loss_clipped)
+                    v_loss = 0.5 * v_loss_max.mean()
+                else:
+                    v_loss = 0.5 * ((newvalue - b_returns[mb_inds]) ** 2).mean()
+
+                entropy_loss = entropy.mean()
+                loss = pg_loss - args.ent_coef * entropy_loss + v_loss * args.vf_coef
+
+
+                accelerator.backward(loss)
+                accelerator.clip_grad_norm_(agent.parameters(), args.max_grad_norm)
+                optimizer.step()
+                optimizer.zero_grad()
+
+            if args.target_kl is not None and approx_kl > args.target_kl:
+                break
+
+        y_pred, y_true = b_values.cpu().numpy(), b_returns.cpu().numpy()
+        var_y = np.var(y_true)
+        explained_var = np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
+
+        # TRY NOT TO MODIFY: record rewards for plotting purposes
+        if accelerator.is_main_process:
+            print("SPS:", int(global_step / (time.time() - start_time)))
+
+            if args.track:
+                writer.add_scalar("charts/learning_rate", optimizer.param_groups[0]["lr"], global_step)
+                writer.add_scalar("losses/value_loss", v_loss.item(), global_step)
+                writer.add_scalar("losses/policy_loss", pg_loss.item(), global_step)
+                writer.add_scalar("losses/entropy", entropy_loss.item(), global_step)
+                writer.add_scalar("losses/old_approx_kl", old_approx_kl.item(), global_step)
+                writer.add_scalar("losses/approx_kl", approx_kl.item(), global_step)
+                writer.add_scalar("losses/clipfrac", np.mean(clipfracs), global_step)
+                writer.add_scalar("losses/explained_variance", explained_var, global_step)
+                writer.add_scalar("charts/SPS", int(global_step / (time.time() - start_time)), global_step)
+
+    envs.close()
+
+    if accelerator.is_main_process:
+        writer.close()
+        if args.track:
+            wandb.finish()
+
+if __name__ == "__main__":
+    main()
+