import copy import glob import os import time import operator from functools import reduce import gym import numpy as np import torch import torch.nn as nn import torch.nn.functional as F import torch.optim as optim from torch.autograd import Variable from arguments import get_args from vec_env.dummy_vec_env import DummyVecEnv from vec_env.subproc_vec_env import SubprocVecEnv from envs import make_env from kfac import KFACOptimizer from model import Policy from storage import RolloutStorage from visualize import visdom_plot args = get_args() assert args.algo in ['a2c', 'ppo', 'acktr'] if args.recurrent_policy: assert args.algo in ['a2c', 'ppo'], 'Recurrent policy is not implemented for ACKTR' num_updates = int(args.num_frames) // args.num_steps // args.num_processes torch.manual_seed(args.seed) if args.cuda: torch.cuda.manual_seed(args.seed) try: os.makedirs(args.log_dir) except OSError: files = glob.glob(os.path.join(args.log_dir, '*.monitor.csv')) for f in files: os.remove(f) def main(): os.environ['OMP_NUM_THREADS'] = '1' envs = [make_env(args.env_name, args.seed, i, args.log_dir) for i in range(args.num_processes)] if args.num_processes > 1: envs = SubprocVecEnv(envs) else: envs = DummyVecEnv(envs) obs_shape = envs.observation_space.shape obs_shape = (obs_shape[0] * args.num_stack, *obs_shape[1:]) obs_numel = reduce(operator.mul, obs_shape, 1) actor_critic = Policy(obs_numel, envs.action_space) # Maxime: log some info about the model and its size modelSize = 0 for p in actor_critic.parameters(): pSize = reduce(operator.mul, p.size(), 1) modelSize += pSize print(str(actor_critic)) print('Total model size: %d' % modelSize) if envs.action_space.__class__.__name__ == "Discrete": action_shape = 1 else: action_shape = envs.action_space.shape[0] if args.cuda: actor_critic.cuda() if args.algo == 'a2c': optimizer = optim.RMSprop(actor_critic.parameters(), args.lr, eps=args.eps, alpha=args.alpha) elif args.algo == 'ppo': optimizer = optim.Adam(actor_critic.parameters(), args.lr, eps=args.eps) elif args.algo == 'acktr': optimizer = KFACOptimizer(actor_critic) rollouts = RolloutStorage(args.num_steps, args.num_processes, obs_shape, envs.action_space, actor_critic.state_size) current_obs = torch.zeros(args.num_processes, *obs_shape) def update_current_obs(obs): shape_dim0 = envs.observation_space.shape[0] obs = torch.from_numpy(obs).float() if args.num_stack > 1: current_obs[:, :-shape_dim0] = current_obs[:, shape_dim0:] current_obs[:, -shape_dim0:] = obs obs = envs.reset() update_current_obs(obs) rollouts.observations[0].copy_(current_obs) # These variables are used to compute average rewards for all processes. episode_rewards = torch.zeros([args.num_processes, 1]) final_rewards = torch.zeros([args.num_processes, 1]) if args.cuda: current_obs = current_obs.cuda() rollouts.cuda() start = time.time() for j in range(num_updates): for step in range(args.num_steps): # Sample actions value, action, action_log_prob, states = actor_critic.act( Variable(rollouts.observations[step], volatile=True), Variable(rollouts.states[step], volatile=True), Variable(rollouts.masks[step], volatile=True) ) cpu_actions = action.data.squeeze(1).cpu().numpy() # Obser reward and next obs obs, reward, done, info = envs.step(cpu_actions) reward = torch.from_numpy(np.expand_dims(np.stack(reward), 1)).float() episode_rewards += reward # If done then clean the history of observations. masks = torch.FloatTensor([[0.0] if done_ else [1.0] for done_ in done]) final_rewards *= masks final_rewards += (1 - masks) * episode_rewards episode_rewards *= masks if args.cuda: masks = masks.cuda() if current_obs.dim() == 4: current_obs *= masks.unsqueeze(2).unsqueeze(2) elif current_obs.dim() == 3: current_obs *= masks.unsqueeze(2) else: current_obs *= masks update_current_obs(obs) rollouts.insert(step, current_obs, states.data, action.data, action_log_prob.data, value.data, reward, masks) next_value = actor_critic( Variable(rollouts.observations[-1], volatile=True), Variable(rollouts.states[-1], volatile=True), Variable(rollouts.masks[-1], volatile=True) )[0].data rollouts.compute_returns(next_value, args.use_gae, args.gamma, args.tau) if args.algo in ['a2c', 'acktr']: values, action_log_probs, dist_entropy, states = actor_critic.evaluate_actions( Variable(rollouts.observations[:-1].view(-1, *obs_shape)), Variable(rollouts.states[:-1].view(-1, actor_critic.state_size)), Variable(rollouts.masks[:-1].view(-1, 1)), Variable(rollouts.actions.view(-1, action_shape)) ) values = values.view(args.num_steps, args.num_processes, 1) action_log_probs = action_log_probs.view(args.num_steps, args.num_processes, 1) advantages = Variable(rollouts.returns[:-1]) - values value_loss = advantages.pow(2).mean() action_loss = -(Variable(advantages.data) * action_log_probs).mean() if args.algo == 'acktr' and optimizer.steps % optimizer.Ts == 0: # Sampled fisher, see Martens 2014 actor_critic.zero_grad() pg_fisher_loss = -action_log_probs.mean() value_noise = Variable(torch.randn(values.size())) if args.cuda: value_noise = value_noise.cuda() sample_values = values + value_noise vf_fisher_loss = -(values - Variable(sample_values.data)).pow(2).mean() fisher_loss = pg_fisher_loss + vf_fisher_loss optimizer.acc_stats = True fisher_loss.backward(retain_graph=True) optimizer.acc_stats = False optimizer.zero_grad() (value_loss * args.value_loss_coef + action_loss - dist_entropy * args.entropy_coef).backward() if args.algo == 'a2c': nn.utils.clip_grad_norm(actor_critic.parameters(), args.max_grad_norm) optimizer.step() elif args.algo == 'ppo': advantages = rollouts.returns[:-1] - rollouts.value_preds[:-1] advantages = (advantages - advantages.mean()) / (advantages.std() + 1e-5) for e in range(args.ppo_epoch): if args.recurrent_policy: data_generator = rollouts.recurrent_generator(advantages, args.num_mini_batch) else: data_generator = rollouts.feed_forward_generator(advantages, args.num_mini_batch) for sample in data_generator: observations_batch, states_batch, actions_batch, \ return_batch, masks_batch, old_action_log_probs_batch, \ adv_targ = sample # Reshape to do in a single forward pass for all steps values, action_log_probs, dist_entropy, states = actor_critic.evaluate_actions( Variable(observations_batch), Variable(states_batch), Variable(masks_batch), Variable(actions_batch) ) adv_targ = Variable(adv_targ) ratio = torch.exp(action_log_probs - Variable(old_action_log_probs_batch)) surr1 = ratio * adv_targ surr2 = torch.clamp(ratio, 1.0 - args.clip_param, 1.0 + args.clip_param) * adv_targ action_loss = -torch.min(surr1, surr2).mean() # PPO's pessimistic surrogate (L^CLIP) value_loss = (Variable(return_batch) - values).pow(2).mean() optimizer.zero_grad() (value_loss + action_loss - dist_entropy * args.entropy_coef).backward() nn.utils.clip_grad_norm(actor_critic.parameters(), args.max_grad_norm) optimizer.step() rollouts.after_update() if j % args.save_interval == 0 and args.save_dir != "": save_path = os.path.join(args.save_dir, args.algo) try: os.makedirs(save_path) except OSError: pass # A really ugly way to save a model to CPU save_model = actor_critic if args.cuda: save_model = copy.deepcopy(actor_critic).cpu() save_model = [save_model, hasattr(envs, 'ob_rms') and envs.ob_rms or None] torch.save(save_model, os.path.join(save_path, args.env_name + ".pt")) if j % args.log_interval == 0: end = time.time() total_num_steps = (j + 1) * args.num_processes * args.num_steps print( "Updates {}, num timesteps {}, FPS {}, mean/median reward {:.1f}/{:.1f}, min/max reward {:.1f}/{:.1f}, entropy {:.5f}, value loss {:.5f}, policy loss {:.5f}". format( j, total_num_steps, int(total_num_steps / (end - start)), final_rewards.mean(), final_rewards.median(), final_rewards.min(), final_rewards.max(), dist_entropy.data[0], value_loss.data[0], action_loss.data[0] ) ) if args.vis and j % args.vis_interval == 0: win = visdom_plot( total_num_steps, final_rewards.mean() ) if __name__ == "__main__": main()