4296a765125fff6491892a1bb70fb32ac516dae6,ch15/01_train_a2c.py,,,#,54

Before Change

                adv_v = vals_ref_v.unsqueeze(dim=-1) - value_v.detach()
                log_prob_v = adv_v * calc_logprob(mu_v, var_v, actions_v)
                loss_policy_v = -log_prob_v.mean()
                entropy_loss_v = ENTROPY_BETA * (-(torch.log(2*math.pi*var_v) + 1)/2).mean()

                loss_v = loss_policy_v + entropy_loss_v + loss_value_v
                loss_v.backward()
                optimizer.step()

After Change

    test_env = gym.make(ENV_ID)

    net_act = model.ModelActor(envs[0].observation_space.shape[0], envs[0].action_space.shape[0])
    net_crt = model.ModelCritic(envs[0].observation_space.shape[0])
    if args.cuda:
        net_act.cuda()
        net_crt.cuda()
    print(net_act)
    print(net_crt)

    writer = SummaryWriter(comment="-a2c_" + args.name)
    agent = model.AgentA2C(net_act, cuda=args.cuda)
    exp_source = ptan.experience.ExperienceSourceFirstLast(envs, agent, GAMMA, steps_count=REWARD_STEPS)

    opt_act = optim.Adam(net_act.parameters(), lr=LEARNING_RATE_ACTOR)
    opt_crt = optim.Adam(net_crt.parameters(), lr=LEARNING_RATE_CRITIC)

    batch = []
    best_reward = None
    with ptan.common.utils.RewardTracker(writer) as tracker:
        with ptan.common.utils.TBMeanTracker(writer, batch_size=100) as tb_tracker:
            for step_idx, exp in enumerate(exp_source):
                rewards_steps = exp_source.pop_rewards_steps()
                if rewards_steps:
                    rewards, steps = zip(*rewards_steps)
                    tb_tracker.track("episode_steps", np.mean(steps), step_idx)
                    tracker.reward(np.mean(rewards), step_idx)

                if step_idx % TEST_ITERS == 0:
                    ts = time.time()
                    rewards, steps = test_net(net_act, test_env, cuda=args.cuda)
                    print("Test done is %.2f sec, reward %.3f, steps %d" % (
                        time.time() - ts, rewards, steps))
                    writer.add_scalar("test_reward", rewards, step_idx)
                    writer.add_scalar("test_steps", steps, step_idx)
                    if best_reward is None or best_reward < rewards:
                        if best_reward is not None:
                            print("Best reward updated: %.3f -> %.3f" % (best_reward, rewards))
                            name = "best_%+.3f_%d.dat" % (rewards, step_idx)
                            fname = os.path.join(save_path, name)
                            torch.save(net_act.state_dict(), fname)
                        best_reward = rewards

                batch.append(exp)
                if len(batch) < BATCH_SIZE:
                    continue

                states_v, actions_v, vals_ref_v = \
                    common.unpack_batch_a2c(batch, net_crt, last_val_gamma=GAMMA ** REWARD_STEPS, cuda=args.cuda)
                batch.clear()

                opt_crt.zero_grad()

Instances