class Agent():
    def __init__(self, state_size, action_size, config):
        self.seed = config["seed"]
        torch.manual_seed(self.seed)
        np.random.seed(seed=self.seed)
        random.seed(self.seed)
        env = gym.make(config["env_name"])
        self.env = FrameStack(env, config)
        self.env.seed(self.seed)
        self.state_size = state_size
        self.action_size = action_size
        self.clip = config["clip"]
        self.device = 'cuda'
        self.double_dqn = config["DDQN"]
        self.lr_pre = config["lr_pre"]
        self.batch_size = config["batch_size"]
        self.lr = config["lr"]
        self.tau = config["tau"]
        self.gamma = 0.99
        self.fc1 = config["fc1_units"]
        self.fc2 = config["fc2_units"]
        self.qnetwork_local = QNetwork(state_size, action_size, self.fc1,
                                       self.fc2, self.seed).to(self.device)
        self.qnetwork_target = QNetwork(state_size, action_size, self.fc1,
                                        self.fc2, self.seed).to(self.device)
        self.optimizer = optim.Adam(self.qnetwork_local.parameters(),
                                    lr=self.lr)
        self.soft_update(self.qnetwork_local, self.qnetwork_target, 1)
        self.q_shift_local = QNetwork(state_size, action_size, self.fc1,
                                      self.fc2, self.seed).to(self.device)
        self.q_shift_target = QNetwork(state_size, action_size, self.fc1,
                                       self.fc2, self.seed).to(self.device)
        self.optimizer_shift = optim.Adam(self.q_shift_local.parameters(),
                                          lr=self.lr)
        self.soft_update(self.q_shift_local, self.q_shift_target, 1)
        self.R_local = QNetwork(state_size, action_size, self.fc1, self.fc2,
                                self.seed).to(self.device)
        self.R_target = QNetwork(state_size, action_size, self.fc1, self.fc2,
                                 self.seed).to(self.device)
        self.optimizer_r = optim.Adam(self.R_local.parameters(), lr=self.lr)
        self.soft_update(self.R_local, self.R_target, 1)
        self.steps = 0
        self.predicter = QNetwork(state_size, action_size, self.fc1, self.fc2,
                                  self.seed).to(self.device)
        self.optimizer_pre = optim.Adam(self.predicter.parameters(),
                                        lr=self.lr_pre)
        #self.encoder_freq = Encoder(config).to(self.device)
        #self.encoder_optimizer_frq = torch.optim.Adam(self.encoder_freq.parameters(), self.lr)
        self.encoder = Encoder(config).to(self.device)
        self.encoder_optimizer = torch.optim.Adam(self.encoder.parameters(),
                                                  self.lr)
        pathname = "lr_{}_batch_size_{}_fc1_{}_fc2_{}_seed_{}".format(
            self.lr, self.batch_size, self.fc1, self.fc2, self.seed)
        pathname += "_clip_{}".format(config["clip"])
        pathname += "_tau_{}".format(config["tau"])
        now = datetime.now()
        dt_string = now.strftime("%d_%m_%Y_%H:%M:%S")
        pathname += dt_string
        tensorboard_name = str(config["locexp"]) + '/runs/' + pathname
        self.vid_path = str(config["locexp"]) + '/vid'
        self.writer = SummaryWriter(tensorboard_name)
        self.average_prediction = deque(maxlen=100)
        self.average_same_action = deque(maxlen=100)
        self.all_actions = []
        for a in range(self.action_size):
            action = torch.Tensor(1) * 0 + a
            self.all_actions.append(action.to(self.device))

    def learn(self, memory_ex):
        logging.debug(
            "--------------------------New update-----------------------------------------------"
        )
        self.steps += 1
        states, next_states, actions, dones = memory_ex.expert_policy(
            self.batch_size)
        states = states.type(torch.float32).div_(255)
        states = self.encoder.create_vector(states)
        next_states = next_states.type(torch.float32).div_(255)
        next_states = self.encoder.create_vector(next_states)
        self.state_action_frq(states, actions)
        actions = torch.randint(0,
                                3, (self.batch_size, 1),
                                dtype=torch.int64,
                                device=self.device)
        self.compute_shift_function(states.detach(), next_states, actions,
                                    dones)
        self.compute_r_function(states.detach(), actions)
        self.compute_q_function(states.detach(), next_states, actions, dones)
        self.soft_update(self.R_local, self.R_target, self.tau)
        self.soft_update(self.q_shift_local, self.q_shift_target, self.tau)
        self.soft_update(self.qnetwork_local, self.qnetwork_target, self.tau)
        return

    def compute_q_function(self, states, next_states, actions, dones):
        """Update value parameters using given batch of experience tuples. """
        actions = actions.type(torch.int64)
        # Get max predicted Q values (for next states) from target model
        if self.double_dqn:
            q_values = self.qnetwork_local(next_states).detach()
            _, best_action = q_values.max(1)
            best_action = best_action.unsqueeze(1)
            Q_targets_next = self.qnetwork_target(next_states).detach()
            Q_targets_next = Q_targets_next.gather(1, best_action)
        else:
            Q_targets_next = self.qnetwork_target(next_states).detach().max(
                1)[0].unsqueeze(1)
        # Compute Q targets for current states
        # Get expected Q values from local model
        # Compute loss
        rewards = self.R_target(states).detach().gather(
            1, actions.detach()).squeeze(0)
        Q_targets = rewards + (self.gamma * Q_targets_next * (dones))
        Q_expected = self.qnetwork_local(states).gather(1, actions)
        loss = F.mse_loss(Q_expected, Q_targets.detach())
        # Get max predicted Q values (for next states) from target model
        self.writer.add_scalar('Q_loss', loss, self.steps)
        # Minimize the loss
        self.optimizer.zero_grad()
        loss.backward()
        self.encoder_optimizer.step()
        # torch.nn.utils.clip_grad_norm_(self.qnetwork_local.parameters(), 1)
        self.optimizer.step()

    def compute_shift_function(self, states, next_states, actions, dones):
        """Update Q shift parameters using given batch of experience tuples  """
        actions = actions.type(torch.int64)
        with torch.no_grad():
            # Get max predicted Q values (for next states) from target model
            if self.double_dqn:
                q_shift = self.q_shift_local(next_states)
                max_q, max_actions = q_shift.max(1)
                Q_targets_next = self.qnetwork_target(next_states).gather(
                    1, max_actions.unsqueeze(1))
            else:
                Q_targets_next = self.qnetwork_target(
                    next_states).detach().max(1)[0].unsqueeze(1)
            # Compute Q targets for current states
            Q_targets = self.gamma * Q_targets_next
        # Get expected Q values from local model
        Q_expected = self.q_shift_local(states).gather(1, actions)
        # Compute loss
        loss = F.mse_loss(Q_expected, Q_targets.detach())
        # Minimize the loss
        self.optimizer_shift.zero_grad()
        loss.backward()
        self.writer.add_scalar('Shift_loss', loss, self.steps)
        self.optimizer_shift.step()

    def compute_r_function(self, states, actions, debug=False, log=False):
        """ compute reward for the state action pair """
        actions = actions.type(torch.int64)
        # sum all other actions
        size = states.shape[0]
        idx = 0
        all_zeros = [1 for i in range(actions.shape[0])]
        zeros = False
        y_shift = self.q_shift_target(states).gather(1, actions).detach()
        log_a = self.get_action_prob(states, actions).detach()
        y_r_part1 = log_a - y_shift
        y_r_part2 = torch.empty((size, 1), dtype=torch.float32).to(self.device)
        for a, s in zip(actions, states):
            y_h = 0
            taken_actions = 0
            for b in self.all_actions:
                b = b.type(torch.int64).unsqueeze(1)
                n_b = self.get_action_prob(s.unsqueeze(0), b)
                if torch.eq(a, b) or n_b is None:
                    continue
                taken_actions += 1
                y_s = self.q_shift_target(s.unsqueeze(0)).detach().gather(
                    1, b).item()
                n_b = n_b.data.item() - y_s
                r_hat = self.R_target(s.unsqueeze(0)).gather(1, b).item()
                y_h += (r_hat - n_b)
                if log:
                    text = "a {} r _hat {:.2f} - n_b  {:.2f} | sh {:.2f} ".format(
                        b.item(), r_hat, n_b, y_s)
                    logging.debug(text)
            if taken_actions == 0:
                all_zeros[idx] = 0
                zeros = True
                y_r_part2[idx] = 0.0
            else:
                y_r_part2[idx] = (1. / taken_actions) * y_h
            idx += 1
            y_r = y_r_part1 + y_r_part2
        # check if there are zeros (no update for this tuble) remove them from states and
        if zeros:
            mask = torch.BoolTensor(all_zeros)
            states = states[mask]
            actions = actions[mask]
            y_r = y_r[mask]
        y = self.R_local(states).gather(1, actions)
        if log:
            text = "Action {:.2f} r target {:.2f} =  n_a {:.2f} + n_b {:.2f}  y {:.2f}".format(
                actions[0].item(), y_r[0].item(), y_r_part1[0].item(),
                y_r_part2[0].item(), y[0].item())
            logging.debug(text)
        r_loss = F.mse_loss(y, y_r.detach())
        # Minimize the loss
        self.optimizer_r.zero_grad()
        r_loss.backward()
        # torch.nn.utils.clip_grad_norm_(self.R_local.parameters(), 5)
        self.optimizer_r.step()
        self.writer.add_scalar('Reward_loss', r_loss, self.steps)

    def get_action_prob(self, states, actions):
        """ compute prob for state action pair """
        actions = actions.type(torch.long)
        # check if action prob is zero
        output = self.predicter(states)
        output = F.softmax(output, dim=1)
        action_prob = output.gather(1, actions)
        action_prob = action_prob + torch.finfo(torch.float32).eps
        # check if one action if its to small
        if action_prob.shape[0] == 1:
            if action_prob.cpu().detach().numpy()[0][0] < 1e-4:
                return None
        action_prob = torch.log(action_prob)
        action_prob = torch.clamp(action_prob, min=self.clip, max=0)
        return action_prob

    def state_action_frq(self, states, action):
        """ Train classifer to compute state action freq """
        self.predicter.train()
        output = self.predicter(states)
        output = output.squeeze(0)
        y = action.type(torch.long).squeeze(1)
        loss = nn.CrossEntropyLoss()(output, y)
        self.optimizer_pre.zero_grad()
        self.encoder_optimizer.zero_grad()
        loss.backward()
        # torch.nn.utils.clip_grad_norm_(self.predicter.parameters(), 1)
        self.optimizer_pre.step()
        self.writer.add_scalar('Predict_loss', loss, self.steps)
        self.predicter.eval()

    def test_predicter(self, memory):
        """ Test the classifier """
        self.predicter.eval()
        same_state_predition = 0
        for i in range(memory.idx):
            states = memory.obses[i]
            actions = memory.actions[i]
            states = torch.as_tensor(states, device=self.device).unsqueeze(0)
            states = states.type(torch.float32).div_(255)
            states = self.encoder.create_vector(states)
            actions = torch.as_tensor(actions, device=self.device)
            output = self.predicter(states)
            output = F.softmax(output, dim=1)
            # create one hot encode y from actions
            y = actions.type(torch.long).item()
            p = torch.argmax(output.data).item()
            if y == p:
                same_state_predition += 1
        text = "Same prediction {} of {} ".format(same_state_predition,
                                                  memory.idx)
        print(text)
        logging.debug(text)

    def soft_update(self, local_model, target_model, tau=4):
        """Soft update model parameters.
        θ_target = τ*θ_local + (1 - τ)*θ_target
        Params
        ======
            local_model (PyTorch model): weights will be copied from
            target_model (PyTorch model): weights will be copied to
            tau (float): interpolation parameter
        """
        # print("use tau", tau)
        for target_param, local_param in zip(target_model.parameters(),
                                             local_model.parameters()):
            target_param.data.copy_(tau * local_param.data +
                                    (1.0 - tau) * target_param.data)

    def load(self, filename):
        self.predicter.load_state_dict(torch.load(filename + "_predicter.pth"))
        self.optimizer_pre.load_state_dict(
            torch.load(filename + "_predicter_optimizer.pth"))
        self.R_local.load_state_dict(torch.load(filename + "_r_net.pth"))
        self.qnetwork_local.load_state_dict(torch.load(filename +
                                                       "_q_net.pth"))
        print("Load models to {}".format(filename))

    def save(self, filename):
        """
        """
        mkdir("", filename)
        torch.save(self.predicter.state_dict(), filename + "_predicter.pth")
        torch.save(self.optimizer_pre.state_dict(),
                   filename + "_predicter_optimizer.pth")
        torch.save(self.qnetwork_local.state_dict(), filename + "_q_net.pth")
        torch.save(self.optimizer.state_dict(),
                   filename + "_q_net_optimizer.pth")
        torch.save(self.R_local.state_dict(), filename + "_r_net.pth")
        torch.save(self.q_shift_local.state_dict(),
                   filename + "_q_shift_net.pth")
        print("save models to {}".format(filename))

    def test_q_value(self, memory):
        test_elements = memory.idx
        test_elements = 100
        all_diff = 0
        error = True
        used_elements_r = 0
        used_elements_q = 0
        r_error = 0
        q_error = 0
        for i in range(test_elements):
            states = memory.obses[i]
            actions = memory.actions[i]
            states = torch.as_tensor(states, device=self.device).unsqueeze(0)
            states = states.type(torch.float32).div_(255)
            states = self.encoder.create_vector(states)
            actions = torch.as_tensor(actions, device=self.device)
            one_hot = torch.Tensor([0 for i in range(self.action_size)],
                                   device="cpu")
            one_hot[actions.item()] = 1
            with torch.no_grad():
                r_values = self.R_local(states.detach()).detach()
                q_values = self.qnetwork_local(states.detach()).detach()
                soft_r = F.softmax(r_values, dim=1).to("cpu")
                soft_q = F.softmax(q_values, dim=1).to("cpu")
                actions = actions.type(torch.int64)
                kl_q = F.kl_div(soft_q.log(), one_hot, None, None, 'sum')
                kl_r = F.kl_div(soft_r.log(), one_hot, None, None, 'sum')
                if kl_r == float("inf"):
                    pass
                else:
                    r_error += kl_r
                    used_elements_r += 1
                if kl_q == float("inf"):
                    pass
                else:
                    q_error += kl_q
                    used_elements_q += 1

        average_q_kl = q_error / used_elements_q
        average_r_kl = r_error / used_elements_r
        text = "Kl div of Reward {} of {} elements".format(
            average_q_kl, used_elements_r)
        print(text)
        text = "Kl div of Q_values {} of {} elements".format(
            average_r_kl, used_elements_q)
        print(text)
        self.writer.add_scalar('KL_reward', average_r_kl, self.steps)
        self.writer.add_scalar('KL_q_values', average_q_kl, self.steps)

    def act(self, states):
        states = torch.as_tensor(states, device=self.device).unsqueeze(0)
        states = states.type(torch.float32).div_(255)
        states = self.encoder.create_vector(states)
        q_values = self.qnetwork_local(states.detach()).detach()
        action = torch.argmax(q_values).item()
        return action

    def eval_policy(self, record=False, eval_episodes=2):
        if record:
            env = wrappers.Monitor(self.env,
                                   str(self.vid_path) +
                                   "/{}".format(self.steps),
                                   video_callable=lambda episode_id: True,
                                   force=True)
        else:
            env = self.env
        average_reward = 0
        scores_window = deque(maxlen=100)
        s = 0
        for i_epiosde in range(eval_episodes):
            episode_reward = 0
            state = env.reset()
            while True:
                s += 1
                action = self.act(state)
                state, reward, done, _ = env.step(action)
                episode_reward += reward
                if done:
                    break
            scores_window.append(episode_reward)
        if record:
            return
        average_reward = np.mean(scores_window)
        print("Eval Episode {}  average Reward {} ".format(
            eval_episodes, average_reward))
        self.writer.add_scalar('Eval_reward', average_reward, self.steps)
示例#2
0
class TD3():
    def __init__(self, action_size, state_size, config):
        self.seed = config["seed"]
        print("TD3 seed", self.seed)
        torch.manual_seed(self.seed)
        np.random.seed(seed=self.seed)
        random.seed(self.seed)
        self.env = gym.make(config["env_name"])
        self.env.seed(self.seed)
        now = datetime.now()
        dt_string = now.strftime("%d_%m_%Y_%H:%M:%S")
        self.env.action_space.seed(self.seed)
        self.action_size = action_size
        self.state_size = state_size
        self.min_action = config["min_action"]
        self.max_action = config["max_action"]
        self.seed = config["seed"]
        self.tau = config["tau"]
        self.gamma = config["gamma"]
        self.batch_size = config["batch_size"]
        if not torch.cuda.is_available():
            config["device"] == "cpu"
        self.device = config["device"]
        self.eval = config["eval"]
        self.vid_path = config["vid_path"]
        print("actions size ", action_size)
        print("actions min ", self.min_action)
        print("actions max ", self.max_action)
        fc1 = config["fc1_units"]
        fc2 = config["fc2_units"]
        self.actor = Actor(state_size, action_size, self.seed, fc1, fc2).to(self.device)
        self.optimizer_a = torch.optim.Adam(self.actor.parameters(), config["lr_actor"])
        self.target_actor = Actor(state_size, action_size, self.seed, fc1, fc2).to(self.device)
        self.target_actor.load_state_dict(self.actor.state_dict()) 
        self.critic = QNetwork(state_size, action_size, self.seed, fc1, fc2).to(self.device)
        self.optimizer_q = torch.optim.Adam(self.critic.parameters(), config["lr_critic"])
        self.target_critic = QNetwork(state_size, action_size, self.seed, fc1, fc2).to(self.device)
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.max_timesteps = config["max_episodes_steps"]
        self.episodes = config["episodes"]
        self.memory = ReplayBuffer((state_size, ), (action_size, ), config["buffer_size"], self.seed, self.device)
        pathname = str(config["seed"]) + str(dt_string)
        tensorboard_name = str(config["res_path"]) + '/runs/'+ "TD3" + str(pathname)
        self.writer = SummaryWriter(tensorboard_name)
        self.steps= 0
        self.actor_freq = config["actor_freq"]
        self.policy_noise = config["policy_noise"]
        self.noise_clip = config["noise_clip"]
        self.expl_noise = config["exp_noise"]

    def act(self, state):
        state  = torch.as_tensor(state, dtype=torch.float32, device=self.device)
        action = self.actor(state.unsqueeze(0))
        actions = action.detach().cpu().numpy()[0] 
        actions = actions + + np.random.normal(0, self.max_action * self.expl_noise, size=self.action_size)
        actions = np.clip(actions, self.min_action, self.max_action)
        return actions
    
    def act_greedy(self, state):
        state  = torch.as_tensor(state, dtype=torch.float32, device=self.device)
        action = self.actor(state.unsqueeze(0))
        actions = action.detach().cpu().numpy()[0]
        actions = np.clip(actions, self.min_action, self.max_action)
        return actions
    
    def train_agent(self):
        average_reward = 0
        scores_window = deque(maxlen=100)
        s = 0
        t0 = time.time()
        for i_epiosde in range(self.episodes):
            episode_reward = 0
            state = self.env.reset()
            for t in range(self.max_timesteps):
                s += 1
                action = self.act(state)
                next_state, reward, done, _ = self.env.step(action)
                episode_reward += reward
                if i_epiosde > 10:
                    self.learn()
                self.memory.add(state, reward, action, next_state, done)
                state = next_state
                if done:
                    scores_window.append(episode_reward)
                    break
            if i_epiosde % self.eval == 0:
                self.eval_policy()
            ave_reward = np.mean(scores_window)
            print("Epiosde {} Steps {} Reward {} Reward averge{} Time {}".format(i_epiosde, t, episode_reward, np.mean(scores_window), time_format(time.time() - t0)))
            self.writer.add_scalar('Aver_reward', ave_reward, self.steps)
            self.writer.add_scalar('steps_in_episode', t, self.steps)
            
    
    def learn(self):
        self.steps += 1
        states, rewards, actions, next_states, dones = self.memory.sample(self.batch_size)
        with torch.no_grad():
            next_action = self.target_actor(next_states)
            noise = (torch.randn_like(actions) * self.policy_noise).clamp(-self.noise_clip, self.noise_clip)
            print(noise)
            next_action = (next_action + noise).clamp(-self.max_action, self.max_action)
            q1_target, q2_target = self.target_critic(next_states, next_action)
            q_target = torch.min(q1_target, q2_target)
            q_target = rewards + (self.gamma * q_target * (1 - dones))
        q_pre1, q_pre2 = self.critic(states, actions)
        loss = F.mse_loss(q_pre1, q_target) + F.mse_loss(q_pre2, q_target)
        self.writer.add_scalar('Q_loss', loss, self.steps)
        self.optimizer_q.zero_grad()
        loss.backward()
        self.optimizer_q.step()
        # delay actor update
        if self.steps % self.actor_freq == 0:
            #-------------------------------update-actor-------------------------------------------------
            actor_actions  = self.actor(states)
            q_values = self.critic.Q1(states, actor_actions)
            loss_actor = -q_values.mean()
            self.optimizer_a.zero_grad()
            loss_actor.backward()
            self.writer.add_scalar('Actor_loss', loss_actor, self.steps)
            self.optimizer_a.step()
            #-------------------------------update-networks-------------------------------------------------
            self.soft_udapte(self.critic, self.target_critic)
            self.soft_udapte(self.actor, self.target_actor)
    
    
    def soft_udapte(self, online, target):
        for param, target_parm in zip(online.parameters(), target.parameters()):
            target_parm.data.copy_(self.tau * param.data + (1 - self.tau) * target_parm.data)


    def eval_policy(self, eval_episodes=4):
        env  = wrappers.Monitor(self.env, str(self.vid_path) + "/{}".format(self.steps), video_callable=lambda episode_id: True,force=True)
        average_reward = 0
        scores_window = deque(maxlen=100)
        for i_epiosde in range(eval_episodes):
            print("Eval Episode {} of {} ".format(i_epiosde, self.episodes))
            episode_reward = 0
            state = env.reset()
            while True: 
                action = self.act_greedy(state)
                state, reward, done, _ = env.step(action)
                episode_reward += reward
                if done:
                    scores_window.append(episode_reward)
                    break
        average_reward = np.mean(scores_window)
        self.writer.add_scalar('Eval_reward', average_reward, self.steps)
class SACAgent():
    def __init__(self, action_size, state_size, config):
        self.seed = config["seed"]
        torch.manual_seed(self.seed)
        np.random.seed(seed=self.seed)
        self.env = gym.make(config["env_name"])
        self.env = FrameStack(self.env, config)
        self.env.seed(self.seed)
        self.action_size = action_size
        self.state_size = state_size
        self.tau = config["tau"]
        self.gamma = config["gamma"]
        self.batch_size = config["batch_size"]
        self.lr = config["lr"]
        self.history_length = config["history_length"]
        self.size = config["size"]
        if not torch.cuda.is_available():
            config["device"] == "cpu"
        self.device = config["device"]
        self.eval = config["eval"]
        self.vid_path = config["vid_path"]
        print("actions size ", action_size)
        self.critic = QNetwork(state_size, action_size, config["fc1_units"],
                               config["fc2_units"]).to(self.device)
        self.q_optim = torch.optim.Adam(self.critic.parameters(),
                                        config["lr_critic"])
        self.target_critic = QNetwork(state_size, action_size,
                                      config["fc1_units"],
                                      config["fc2_units"]).to(self.device)
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.log_alpha = torch.zeros(1, requires_grad=True, device=self.device)
        self.alpha = self.log_alpha.exp()
        self.alpha_optim = Adam([self.log_alpha], lr=config["lr_alpha"])
        self.policy = SACActor(state_size, action_size).to(self.device)
        self.policy_optim = Adam(self.policy.parameters(),
                                 lr=config["lr_policy"])
        self.encoder = Encoder(config).to(self.device)
        self.encoder_optimizer = torch.optim.Adam(self.encoder.parameters(),
                                                  self.lr)
        self.episodes = config["episodes"]
        self.memory = ReplayBuffer((self.history_length, self.size, self.size),
                                   (1, ), config["buffer_size"],
                                   config["image_pad"], self.seed, self.device)
        pathname = config["seed"]
        tensorboard_name = str(config["res_path"]) + '/runs/' + str(pathname)
        self.writer = SummaryWriter(tensorboard_name)
        self.steps = 0
        self.target_entropy = -torch.prod(
            torch.Tensor(action_size).to(self.device)).item()

    def act(self, state, evaluate=False):
        with torch.no_grad():
            state = torch.FloatTensor(state).to(self.device).unsqueeze(0)
            state = state.type(torch.float32).div_(255)
            self.encoder.eval()
            state = self.encoder.create_vector(state)
            self.encoder.train()
            if evaluate is False:
                action = self.policy.sample(state)
            else:
                action_prob, _ = self.policy(state)
                action = torch.argmax(action_prob)
                action = action.cpu().numpy()
                return action
            # action = np.clip(action, self.min_action, self.max_action)
            action = action.cpu().numpy()[0]
        return action

    def train_agent(self):
        average_reward = 0
        scores_window = deque(maxlen=100)
        t0 = time.time()
        for i_epiosde in range(1, self.episodes):
            episode_reward = 0
            state = self.env.reset()
            t = 0
            while True:
                t += 1
                action = self.act(state)
                next_state, reward, done, _ = self.env.step(action)
                episode_reward += reward
                if i_epiosde > 10:
                    self.learn()
                self.memory.add(state, reward, action, next_state, done)
                state = next_state
                if done:
                    scores_window.append(episode_reward)
                    break
            if i_epiosde % self.eval == 0:
                self.eval_policy()
            ave_reward = np.mean(scores_window)
            print("Epiosde {} Steps {} Reward {} Reward averge{:.2f} Time {}".
                  format(i_epiosde, t, episode_reward, np.mean(scores_window),
                         time_format(time.time() - t0)))
            self.writer.add_scalar('Aver_reward', ave_reward, self.steps)

    def learn(self):
        self.steps += 1
        states, rewards, actions, next_states, dones = self.memory.sample(
            self.batch_size)
        states = states.type(torch.float32).div_(255)
        states = self.encoder.create_vector(states)
        states_detached = states.detach()
        qf1, qf2 = self.critic(states)
        q_value1 = qf1.gather(1, actions)
        q_value2 = qf2.gather(1, actions)

        with torch.no_grad():
            next_states = next_states.type(torch.float32).div_(255)
            next_states = self.encoder.create_vector(next_states)
            q1_target, q2_target = self.target_critic(next_states)
            min_q_target = torch.min(q1_target, q2_target)
            next_action_prob, next_action_log_prob = self.policy(next_states)
            next_q_target = (
                next_action_prob *
                (min_q_target - self.alpha * next_action_log_prob)).sum(
                    dim=1, keepdim=True)
            next_q_value = rewards + (1 - dones) * self.gamma * next_q_target

        # --------------------------update-q--------------------------------------------------------
        loss = F.mse_loss(q_value1, next_q_value) + F.mse_loss(
            q_value2, next_q_value)
        self.q_optim.zero_grad()
        self.encoder_optimizer.zero_grad()
        loss.backward()
        self.q_optim.step()
        self.encoder_optimizer.zero_grad()
        self.writer.add_scalar('loss/q', loss, self.steps)

        # --------------------------update-policy--------------------------------------------------------
        action_prob, log_action_prob = self.policy(states_detached)
        with torch.no_grad():
            q_pi1, q_pi2 = self.critic(states_detached)
            min_q_values = torch.min(q_pi1, q_pi2)
        #policy_loss = (action_prob *  ((self.alpha * log_action_prob) - min_q_values).detach()).sum(dim=1).mean()
        policy_loss = (action_prob *
                       ((self.alpha * log_action_prob) - min_q_values)).sum(
                           dim=1).mean()
        self.policy_optim.zero_grad()
        policy_loss.backward()
        self.policy_optim.step()
        self.writer.add_scalar('loss/policy', policy_loss, self.steps)

        # --------------------------update-alpha--------------------------------------------------------
        alpha_loss = (action_prob.detach() *
                      (-self.log_alpha *
                       (log_action_prob + self.target_entropy).detach())).sum(
                           dim=1).mean()
        self.alpha_optim.zero_grad()
        alpha_loss.backward()
        self.alpha_optim.step()
        self.writer.add_scalar('loss/alpha', alpha_loss, self.steps)
        self.soft_udapte(self.critic, self.target_critic)
        self.alpha = self.log_alpha.exp()

    def soft_udapte(self, online, target):
        for param, target_parm in zip(online.parameters(),
                                      target.parameters()):
            target_parm.data.copy_(self.tau * param.data +
                                   (1 - self.tau) * target_parm.data)

    def eval_policy(self, eval_episodes=4):
        env = gym.make(self.env_name)
        env = wrappers.Monitor(env,
                               str(self.vid_path) + "/{}".format(self.steps),
                               video_callable=lambda episode_id: True,
                               force=True)
        average_reward = 0
        scores_window = deque(maxlen=100)
        for i_epiosde in range(eval_episodes):
            print("Eval Episode {} of {} ".format(i_epiosde, eval_episodes))
            episode_reward = 0
            state = env.reset()
            while True:
                action = self.act(state, evaluate=True)
                state, reward, done, _ = env.step(action)
                episode_reward += reward
                if done:
                    break
            scores_window.append(episode_reward)
        average_reward = np.mean(scores_window)
        self.writer.add_scalar('Eval_reward', average_reward, self.steps)
示例#4
0
def train(args):
    chrome_driver_path = args.chrome_driver_path
    checkpoint_path = args.checkpoint_path
    nb_actions = args.nb_actions
    initial_epsilon = args.initial_epsilon
    epsilon = initial_epsilon
    final_epsilon = args.final_epsilon
    gamma = args.gamma
    nb_memory = args.nb_memory
    nb_expolre = args.nb_expolre
    is_debug = args.is_debug
    batch_size = args.batch_size
    nb_observation = args.nb_observation
    desired_fps = args.desired_fps
    is_cuda = True if args.use_cuda and torch.cuda.is_available() else False
    log_frequency = args.log_frequency
    save_frequency = args.save_frequency
    ratio_of_win = args.ratio_of_win
    if args.exploiting:
        nb_observation = -1
        epsilon = final_epsilon

    seed = 22
    np.random.seed(seed)
    memory = deque()
    env = DinoSeleniumEnv(chrome_driver_path, speed=args.game_speed)
    agent = Agent(env)
    game_state = GameState(agent, debug=is_debug)
    qnetwork = QNetwork(nb_actions)
    if is_cuda:
        qnetwork.cuda()
    optimizer = torch.optim.Adam(qnetwork.parameters(), 1e-4)
    tmp_param = next(qnetwork.parameters())
    try:
        m = torch.load(checkpoint_path)
        qnetwork.load_state_dict(m["qnetwork"])
        optimizer.load_state_dict(m["optimizer"])
    except:
        logger.warn("No model found in {}".format(checkpoint_path))
    loss_fcn = torch.nn.MSELoss()
    action_indx = 0  # do nothing as the first action
    screen, reward, is_gameover, score = game_state.get_state(action_indx)
    current_state = np.expand_dims(screen, 0)
    # [IMAGE_CHANNELS,IMAGE_WIDTH,IMAGE_HEIGHT]
    current_state = np.tile(current_state, (IMAGE_CHANNELS, 1, 1))
    initial_state = current_state

    t = 0
    last_time = 0
    sum_scores = 0
    total_loss = 0
    max_score = 0
    qvalues = np.array([0, 0])
    lost_action = []
    win_actions = []
    action_random = 0
    action_greedy = 0
    episodes = 0
    nb_episodes = 0
    if not args.exploiting:
        try:
            t, memory, epsilon, nb_episodes = pickle.load(open(
                "cache.p", "rb"))
        except:
            logger.warn("Could not load cache file! Starting from scratch.")
    try:
        while True:
            qnetwork.eval()
            if np.random.random() < epsilon:  # epsilon greedy
                action_indx = np.random.randint(nb_actions)
                action_random += 1
            else:
                action_greedy += 1
                tensor = torch.from_numpy(current_state).float().unsqueeze(0)
                with torch.no_grad():
                    qvalues = qnetwork(tensor).squeeze()
                _, action_indx = qvalues.max(-1)
                action_indx = action_indx.item()
            if epsilon > final_epsilon and t > nb_observation:
                epsilon -= (initial_epsilon - final_epsilon) / nb_expolre
            screen, reward, is_gameover, score = game_state.get_state(
                action_indx)
            if is_gameover:
                episodes += 1
                nb_episodes += 1
                lost_action.append(action_indx)
                sum_scores += score
            else:
                win_actions.append(action_indx)
            if score > max_score:
                max_score = score
            if last_time:
                fps = 1 / (time.time() - last_time)
                if fps > desired_fps:
                    time.sleep(1 / desired_fps - 1 / fps)
            if last_time and t % log_frequency == 0:
                logger.info('fps: {0}'.format(1 / (time.time() - last_time)))
            last_time = time.time()
            screen = np.expand_dims(screen, 0)
            next_state = np.append(screen,
                                   current_state[:IMAGE_CHANNELS - 1, :, :],
                                   axis=0)
            if not args.exploiting and (is_gameover
                                        or np.random.random() < ratio_of_win):
                memory.append((current_state, action_indx, reward, next_state,
                               is_gameover))
            if len(memory) > nb_memory:
                memory.popleft()
            if nb_observation > 0 and t > nb_observation:
                indxes = np.random.choice(len(memory),
                                          batch_size,
                                          replace=False)
                minibatch = [memory[b] for b in indxes]
                inputs = tmp_param.new(batch_size, IMAGE_CHANNELS, IMAGE_WIDTH,
                                       IMAGE_HEIGHT).zero_()
                targets = tmp_param.new(batch_size, nb_actions).zero_()
                for i, (state_t, action_t, reward_t, state_t1,
                        is_gameover_t1) in enumerate(minibatch):
                    inputs[i] = torch.from_numpy(state_t).float()
                    tensor = inputs[i].unsqueeze(0)
                    with torch.no_grad():
                        qvalues = qnetwork(tensor).squeeze()
                    targets[i] = qvalues
                    if is_gameover_t1:
                        assert reward_t == -1
                        targets[i, action_t] = reward_t
                    else:
                        tensor = torch.from_numpy(state_t1).float().unsqueeze(
                            0)
                        with torch.no_grad():
                            qvalues = qnetwork(tensor).squeeze()
                        qvalues = qvalues.cpu().numpy()
                        targets[i, action_t] = reward_t + gamma * qvalues.max()
                qnetwork.train()
                qnetwork.zero_grad()
                q_values = qnetwork(inputs)
                loss = loss_fcn(q_values, targets)
                loss.backward()
                optimizer.step()
                total_loss += loss.item()
            current_state = initial_state if is_gameover else next_state
            t += 1
            if t % log_frequency == 0:
                logger.info(
                    "For t {}: mean score is {} max score is {} mean loss: {} number of episode: {}"
                    .format(t, sum_scores / (episodes + 0.1), max_score,
                            total_loss / 1000, episodes))
                logger.info(
                    "t: {} action_index: {} reward: {} max qvalue: {} total number of eposodes so far: {}"
                    .format(t, action_indx, reward, qvalues.max(),
                            nb_episodes))
                tmp = np.array(lost_action)
                dnc = (tmp == 0).sum()
                logger.info(
                    "Lost actions do_nothing: {} jump: {} length of memory {}".
                    format(dnc,
                           len(tmp) - dnc, len(memory)))
                tmp = np.array(win_actions)
                dnc = (tmp == 0).sum()
                logger.info("Win actions do_nothing: {} jump: {}".format(
                    dnc,
                    len(tmp) - dnc))
                logger.info("Greedy action {} Random action {}".format(
                    action_greedy, action_random))
                action_greedy = 0
                action_random = 0
                lost_action = []
                win_actions = []
                if episodes != 0:
                    sum_scores = 0
                total_loss = 0
                episodes = 0
            if t % save_frequency and not args.exploiting:
                env.pause_game()
                with open("cache.p", "wb") as fh:
                    pickle.dump((t, memory, epsilon, nb_episodes), fh)
                gc.collect()
                torch.save(
                    {
                        "qnetwork": qnetwork.state_dict(),
                        "optimizer": optimizer.state_dict()
                    }, checkpoint_path)
                env.resume_game()
    except KeyboardInterrupt:
        if not args.exploiting:
            torch.save(
                {
                    "qnetwork": qnetwork.state_dict(),
                    "optimizer": optimizer.state_dict()
                }, checkpoint_path)
            with open("cache.p", "wb") as fh:
                pickle.dump((t, memory, epsilon, nb_episodes), fh)
示例#5
0
from checkpoints.model_checkpoint_backup_config import config
from models import QNetwork

def get_env_configs(config):
    env = gym.make(config["env"])
    config["num_actions"] = env.action_space.n
    config["observation_shape"] = env.observation_space.shape
    return config

if __name__ == '__main__':
    config = get_env_configs(config)

    env = gym.make('CartPole-v1').unwrapped
    net = QNetwork(config)
    print(net.net)
    net.load_state_dict(torch.load("checkpoints/model_checkpoint_backup"))

    high_score = -math.inf
    episode = 0
    num_samples = 0
    while True:
        done = False
        state = env.reset()

        score, frame = 0, 1
        while not done:
            env.render()

            state = torch.tensor(state, dtype=torch.float32)
            state = state.unsqueeze(0)
            qs = net(state)[0]
示例#6
0
class SACAgent():
    def __init__(self, action_size, state_size, config):
        self.action_size = action_size
        self.state_size = state_size
        self.min_action = config["min_action"]
        self.max_action = config["max_action"]
        self.seed = config["seed"]
        self.tau = config["tau"]
        self.gamma = config["gamma"]
        self.batch_size = config["batch_size"]
        if not torch.cuda.is_available():
            config["device"] == "cpu"
        self.device = config["device"]
        self.eval = config["eval"]
        torch.manual_seed(self.seed)
        np.random.seed(self.seed)
        self.vid_path = config["vid_path"]
        print("actions size ", action_size)
        print("actions min ", self.min_action)
        print("actions max ", self.max_action)
        self.critic = QNetwork(state_size, action_size, config["fc1_units"], config["fc2_units"]).to(self.device)
        self.q_optim = torch.optim.Adam(self.critic.parameters(), config["lr_critic"])
        self.target_critic = QNetwork(state_size, action_size, config["fc1_units"], config["fc2_units"]).to(self.device)
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.log_alpha = torch.zeros(1, requires_grad=True, device=self.device)
        self.alpha = self.log_alpha.exp()
        self.alpha_optim = Adam([self.log_alpha], lr=config["lr_alpha"])
        #self.policy = SACActor(state_size, action_size).to(self.device)
        self.policy = GaussianPolicy(state_size, action_size, 256).to(self.device)
        self.policy_optim = Adam(self.policy.parameters(), lr=config["lr_policy"])
        self.max_timesteps = config["max_episodes_steps"]
        self.episodes = config["episodes"]
        self.memory = ReplayBuffer((state_size, ), (action_size, ), config["buffer_size"], self.device)
        pathname = config["seed"]
        tensorboard_name = str(config["res_path"]) + '/runs/' + str(pathname)
        self.writer = SummaryWriter(tensorboard_name)
        self.steps= 0
        self.target_entropy = -torch.prod(torch.Tensor(action_size).to(self.device)).item()

    def act(self, state, evaluate=False):
        with torch.no_grad():
            state = torch.FloatTensor(state).to(self.device).unsqueeze(0)
            if evaluate is False:
                action, _, _ = self.policy.sample(state)
            else:
                _, _, action = self.policy.sample(state)
            # action = np.clip(action, self.min_action, self.max_action)
            action = action.cpu().numpy()[0]
        #print(action)
        return action
    
    def train_agent(self):
        env = gym.make("LunarLanderContinuous-v2")
        average_reward = 0
        scores_window = deque(maxlen=100)
        s = 0
        t0 = time.time()
        for i_epiosde in range(self.episodes):
            episode_reward = 0
            state = env.reset()
            for t in range(self.max_timesteps):
                s += 1
                action = self.act(state)
                next_state, reward, done, _ = env.step(action)
                episode_reward += reward
                if i_epiosde > 3:
                    self.learn()
                self.memory.add(state, reward, action, next_state, done)
                state = next_state
                if done:
                    scores_window.append(episode_reward)
                    break
            if i_epiosde % self.eval == 0:
                self.eval_policy()
            ave_reward = np.mean(scores_window)
            print("Epiosde {} Steps {} Reward {} Reward averge{} Time {}".format(i_epiosde, t, episode_reward, np.mean(scores_window), time_format(time.time() - t0)))
            self.writer.add_scalar('Aver_reward', ave_reward, self.steps)
            
    
    def learn(self):
        self.steps += 1
        states, rewards, actions, next_states, dones = self.memory.sample(self.batch_size)
        with torch.no_grad():
            next_state_action, next_state_log_pi, _ = self.policy.sample(next_states)
            target_q1, target_q2 = self.target_critic(next_states, next_state_action)
            target_min = torch.min(target_q1, target_q2)
            q_target = target_min - (self.alpha * next_state_log_pi)
            next_q_value = rewards + (1 - dones) * self.gamma * q_target
        
        qf1, qf2 = self.critic(states, actions)
        # --------------------------update-q--------------------------------------------------------
        loss = F.mse_loss(qf1, next_q_value) + F.mse_loss(qf2, next_q_value) 
        self.q_optim.zero_grad() 
        loss.backward()
        self.q_optim.step()
        self.writer.add_scalar('loss/q', loss, self.steps)


        # --------------------------update-policy--------------------------------------------------------
        pi, log_pi, _ = self.policy.sample(states)
        q_pi1, q_pi2 = self.critic(states, pi)
        min_q_values = torch.min(q_pi1, q_pi2)
        policy_loss = ((self.alpha * log_pi) - min_q_values).mean()

        self.policy_optim.zero_grad()
        policy_loss.backward()
        self.policy_optim.step()
        self.writer.add_scalar('loss/policy', policy_loss, self.steps)
        
        # --------------------------update-alpha--------------------------------------------------------
        alpha_loss = -(self.log_alpha * (log_pi + self.target_entropy).detach()).mean()
        
        self.alpha_optim.zero_grad()
        alpha_loss.backward()
        self.alpha_optim.step()
        self.writer.add_scalar('loss/alpha', alpha_loss, self.steps)

        self.soft_udapte(self.critic, self.target_critic)
        self.alpha = self.log_alpha.exp()


    
    def soft_udapte(self, online, target):
        for param, target_parm in zip(online.parameters(), target.parameters()):
            target_parm.data.copy_(self.tau * param.data + (1 - self.tau) * target_parm.data)

    def eval_policy(self, eval_episodes=4):
        env = gym.make("LunarLanderContinuous-v2")
        # env  = wrappers.Monitor(env, str(self.vid_path) + "/{}".format(self.steps), video_callable=lambda episode_id: True,force=True)
        average_reward = 0
        scores_window = deque(maxlen=100)
        for i_epiosde in range(eval_episodes):
            print("Eval Episode {} of {} ".format(i_epiosde, eval_episodes))
            episode_reward = 0
            state = env.reset()
            while True: 
                action = self.act(state, evaluate=True)
                state, reward, done, _ = env.step(action)
                episode_reward += reward
                if done:
                    break
            scores_window.append(episode_reward)
        average_reward = np.mean(scores_window)
        self.writer.add_scalar('Eval_reward', average_reward, self.steps)
示例#7
0
class NewSACAgent:
    def __init__(self, env, render, config_info):
        self.env = env
        self.render = render
        self._reset_env()

        # Create run folder to store parameters, figures, and tensorboard logs
        self.path_runs = create_run_folder(config_info)

        # Extract training parameters from yaml config file
        param = load_training_parameters(config_info["config_param"])
        self.train_param = param["training"]

        # Define device
        self.device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
        print(f"Device in use : {self.device}")

        # Define state and action dimension spaces
        state_dim = env.observation_space.shape[0]
        num_actions = env.action_space.shape[0]

        # Define models
        hidden_size = param["model"]["hidden_size"]
        self.q_net = QNetwork(state_dim, num_actions, hidden_size).to(self.device)

        self.target_q_net = QNetwork(state_dim, num_actions, hidden_size).to(
            self.device
        )
        self.target_q_net.load_state_dict(self.q_net.state_dict())

        self.policy_net = PolicyNetwork(state_dim, num_actions, hidden_size).to(
            self.device
        )

        # Define loss criterion
        self.q_criterion = nn.MSELoss()

        # Define optimizers
        lr = float(param["optimizer"]["learning_rate"])
        self.q_opt = optim.Adam(self.q_net.parameters(), lr=lr)
        self.policy_opt = optim.Adam(self.policy_net.parameters(), lr=lr)

        # Initialize replay buffer
        self.replay_buffer = ReplayBuffer(param["training"]["replay_size"])

        self.transition = namedtuple(
            "transition",
            field_names=["state", "action", "reward", "done", "next_state"],
        )

        # Useful variables
        self.batch_size = param["training"]["batch_size"]
        self.gamma = param["training"]["gamma"]
        self.tau = param["training"]["tau"]
        self.start_step = param["training"]["start_step"]
        self.max_timesteps = param["training"]["max_timesteps"]
        self.alpha = param["training"]["alpha"]

    def _reset_env(self):
        # Reset the environment and initialize episode reward
        self.state, self.done = self.env.reset(), False
        self.episode_reward = 0.0
        self.episode_step = 0

    def train(self):
        # Main training loop
        total_timestep = 0
        all_episode_rewards = []
        all_mean_rewards = []
        update = 0

        # Create tensorboard writer
        writer = SummaryWriter(log_dir=self.path_runs, comment="-sac")

        for episode in itertools.count(1, 1):
            self._reset_env()

            while not self.done:
                # trick to improve exploration at the start of training
                if self.start_step > total_timestep:
                    action = self.env.action_space.sample()  # Sample random action
                else:
                    action = self.policy_net.get_action(
                        self.state, self.device
                    )  # Sample action from policy

                # Fill the replay buffer up with transitions
                if len(self.replay_buffer) > self.batch_size:
                    batch = self.replay_buffer.sample_buffer(self.batch_size)

                    # Update parameters of all the networks
                    q1_loss, q2_loss, policy_loss = self.train_on_batch(batch)
                    writer.add_scalar("loss/q1", q1_loss, update)
                    writer.add_scalar("loss/q2", q2_loss, update)
                    writer.add_scalar("loss/policy", policy_loss, update)
                    update += 1

                if self.render:
                    self.env.render()

                # Perform one step in the environment
                next_state, reward, self.done, _ = self.env.step(action)
                total_timestep += 1
                self.episode_step += 1
                self.episode_reward += reward

                # Create a tuple for the new transition
                new_transition = self.transition(
                    self.state, action, reward, self.done, next_state
                )

                # Append transition to the replay buffer
                self.replay_buffer.store_transition(new_transition)

                self.state = next_state

            if total_timestep > self.max_timesteps:
                break

            mean_reward = np.mean(all_episode_rewards[-100:])
            all_episode_rewards.append(self.episode_reward)
            all_mean_rewards.append(mean_reward)

            print(
                "Episode n°{} ; total timestep [{}/{}] ; episode steps {} ; "
                "reward {} ; mean reward {}".format(
                    episode,
                    total_timestep,
                    self.max_timesteps,
                    self.episode_step,
                    round(self.episode_reward, 2),
                    round(mean_reward, 2)
                )
            )

            writer.add_scalar("reward", self.episode_reward, episode)
            writer.add_scalar("mean reward", mean_reward, episode)

        # Save networks' weights
        path_critic = os.path.join(self.path_runs, "critic.pth")
        path_actor = os.path.join(self.path_runs, "actor.pth")
        torch.save(self.q_net.state_dict(), path_critic)
        torch.save(self.policy_net.state_dict(), path_actor)

        # Plot reward
        self.plot_reward(all_episode_rewards, all_mean_rewards)

        # Close all
        writer.close()
        self.env.close()

    def train_on_batch(self, batch_samples):
        # Unpack batch_size of transitions randomly drawn from the replay buffer
        (
            state_batch,
            action_batch,
            reward_batch,
            done_int_batch,
            next_state_batch,
        ) = batch_samples

        # Transform np arrays into tensors and send them to device
        state_batch = torch.tensor(state_batch).to(self.device)
        next_state_batch = torch.tensor(next_state_batch).to(self.device)
        action_batch = torch.tensor(action_batch).to(self.device)
        reward_batch = torch.tensor(reward_batch).unsqueeze(1).to(self.device)
        done_int_batch = torch.tensor(done_int_batch).unsqueeze(1).to(self.device)

        ### Update Q
        with torch.no_grad():
            next_state_action, next_state_log_pi = self.policy_net.sample(
                next_state_batch
            )
            q1_next_target, q2_next_target = self.target_q_net(
                next_state_batch, next_state_action
            )
            min_qf_next_target = (
                torch.min(q1_next_target, q2_next_target)
                - self.alpha * next_state_log_pi
            )
            next_q_value = reward_batch + (1 - done_int_batch) * self.gamma * (
                min_qf_next_target
            )
        # Estimated state-action values
        q1, q2 = self.q_net(state_batch, action_batch)
        q1_loss = self.q_criterion(q1, next_q_value)
        q2_loss = self.q_criterion(q2, next_q_value)

        ### Update policy
        pi, log_pi = self.policy_net.sample(state_batch)
        q1_pi, q2_pi = self.q_net(state_batch, pi)
        # Mitigate positive bias in the policy improvement step
        min_q_pi = torch.min(q1_pi, q2_pi)
        policy_loss = (self.alpha * log_pi - min_q_pi).mean()

        # Losses and optimizers
        self.q_opt.zero_grad()
        q1_loss.backward()
        self.q_opt.step()

        self.q_opt.zero_grad()
        q2_loss.backward()
        self.q_opt.step()

        self.policy_opt.zero_grad()
        policy_loss.backward()
        self.policy_opt.step()

        soft_update(self.target_q_net, self.q_net, self.tau)

        return q1_loss.item(), q2_loss.item(), policy_loss.item()

    def plot_reward(self, data, mean_data):
        plt.plot(data, label="reward")
        plt.plot(mean_data, label="mean reward")
        plt.xlabel("Episode")
        plt.ylabel("Reward")
        plt.title(f"Reward evolution for {self.env.unwrapped.spec.id} Gym environment")
        plt.tight_layout()
        plt.legend()

        path_fig = os.path.join(self.path_runs, "figure.png")
        plt.savefig(path_fig)
        print(f"Figure saved to {path_fig}")

        plt.show()