Ejemplo n.º 1
0
    def __init__(self, mac, scheme, logger, args):
        self.args = args
        self.n_agents = args.n_agents
        self.n_actions = args.n_actions
        self.mac = mac
        self.logger = logger

        self.last_target_update_step = 0
        self.critic_training_steps = 0

        self.log_stats_t = -self.args.learner_log_interval - 1

        self.critic = COMACritic(scheme, args)
        self.target_critic = copy.deepcopy(self.critic)

        self.agent_params = list(mac.parameters())
        self.critic_params = list(self.critic.parameters())
        self.params = self.agent_params + self.critic_params

        self.agent_optimiser = RMSprop(params=self.agent_params,
                                       lr=args.lr,
                                       alpha=args.optim_alpha,
                                       eps=args.optim_eps)
        self.critic_optimiser = RMSprop(params=self.critic_params,
                                        lr=args.critic_lr,
                                        alpha=args.optim_alpha,
                                        eps=args.optim_eps)
Ejemplo n.º 2
0
    def __init__(self, mac, scheme, logger, args):
        self.args = args
        self.n_agents = args.n_agents
        self.n_actions = args.n_actions
        self.logger = logger

        self.mac = mac
        self.agent_params = list(mac.parameters())
        self.agent_optimiser = RMSprop(params=self.agent_params,
                                       lr=args.lr,
                                       alpha=args.optim_alpha,
                                       eps=args.optim_eps)
        self.params = self.agent_params

        if args.critic_q_fn == "coma":
            self.critic = COMACritic(scheme, args)
        elif args.critic_q_fn == "centralV":
            self.critic = CentralVCritic(scheme, args)
        self.target_critic = copy.deepcopy(self.critic)

        self.critic_params = list(self.critic.parameters())
        self.params += self.critic_params
        self.critic_optimiser = RMSprop(params=self.critic_params,
                                        lr=args.critic_lr,
                                        alpha=args.optim_alpha,
                                        eps=args.optim_eps)

        self.separate_baseline_critic = False
        if args.critic_q_fn != args.critic_baseline_fn:
            self.separate_baseline_critic = True
            if args.critic_baseline_fn == "coma":
                self.baseline_critic = COMACritic(scheme, args)
            elif args.critic_baseline_fn == "centralV":
                self.baseline_critic = CentralVCritic(scheme, args)
            self.target_baseline_critic = copy.deepcopy(self.baseline_critic)

            self.baseline_critic_params = list(
                self.baseline_critic.parameters())
            self.params += self.baseline_critic_params
            self.baseline_critic_optimiser = RMSprop(
                params=self.baseline_critic_params,
                lr=args.critic_lr,
                alpha=args.optim_alpha,
                eps=args.optim_eps)

        if args.critic_train_mode == "seq":
            self.critic_train_fn = self.train_critic_sequential
        elif args.critic_train_mode == "batch":
            self.critic_train_fn = self.train_critic_batched
        else:
            raise ValueError

        self.last_target_update_step = 0
        self.critic_training_steps = 0
        self.log_stats_t = -self.args.learner_log_interval - 1
Ejemplo n.º 3
0
    def __init__(self, mac, scheme, logger, args):
        self.args = args
        self.n_agents = args.n_agents
        self.n_actions = args.n_actions
        self.mac = mac
        self.logger = logger

        self.last_target_update_step = 0
        self.critic_training_steps = 0

        self.log_stats_t = -self.args.learner_log_interval - 1

        if args.critic_fact is not None:
            assert args.pair_coma is False
            self.critic = FactoredCOMACritic(scheme, args)
        elif args.pair_coma:
            assert args.critic_fact is None
            self.critic = PairComaCritic(scheme, args)
        else:
            self.critic = COMACritic(scheme, args)

        self.target_critic = copy.deepcopy(self.critic)

        self.agent_params = list(mac.parameters())
        self.critic_params = list(self.critic.parameters())
        self.params = self.agent_params + self.critic_params

        self.agent_optimiser = RMSprop(params=self.agent_params,
                                       lr=args.lr,
                                       alpha=args.optim_alpha,
                                       eps=args.optim_eps)
        self.critic_optimiser = RMSprop(params=self.critic_params,
                                        lr=args.critic_lr,
                                        alpha=args.optim_alpha,
                                        eps=args.optim_eps)

        self.baseline_critic = None
        self.target_baseline_critic = None
        self.test_v_baseline = False
        self.baseline_critic_optimiser = None
        self.baseline_critic_params = None

        if args.test_v_baseline:
            self.test_v_baseline = True
            self.baseline_critic = CentralVCritic(scheme, args)
            self.target_baseline_critic = copy.deepcopy(self.baseline_critic)
            self.baseline_critic_params = list(
                self.baseline_critic.parameters())
            self.baseline_critic_optimiser = RMSprop(
                params=self.baseline_critic_params,
                lr=args.critic_lr,
                alpha=args.optim_alpha,
                eps=args.optim_eps)
Ejemplo n.º 4
0
    def __init__(self, mac, scheme, logger, args):
        self.args = args
        self.n_agents = args.n_agents
        self.n_actions = args.n_actions
        self.mac = mac
        self.logger = logger

        self.last_target_update_step = 0
        self.critic_training_steps = 0

        self.log_stats_t = -self.args.learner_log_interval - 1

        if self.args.critic == 'coma':
            self.critic = COMACritic(scheme, args)
        elif self.args.critic == 'iac_critic':
            self.critic = IACritic(scheme, args)
        else:
            raise ValueError("{} is not implemented".format(self.args.critic))
        self.target_critic = copy.deepcopy(self.critic)

        self.agent_params = list(mac.parameters())
        self.critic_params = list(self.critic.parameters())
        self.params = self.agent_params + self.critic_params

        self.agent_optimiser = RMSprop(params=self.agent_params,
                                       lr=args.lr,
                                       alpha=args.optim_alpha,
                                       eps=args.optim_eps)
        self.critic_optimiser = RMSprop(params=self.critic_params,
                                        lr=args.critic_lr,
                                        alpha=args.optim_alpha,
                                        eps=args.optim_eps)
Ejemplo n.º 5
0
class COMALearner:
    def __init__(self, mac, scheme, logger, args):
        self.args = args
        self.n_agents = args.n_agents
        self.n_actions = args.n_actions
        self.mac = mac
        self.logger = logger

        self.last_target_update_step = 0
        self.critic_training_steps = 0

        self.log_stats_t = -self.args.learner_log_interval - 1

        self.critic = COMACritic(scheme, args)
        self.target_critic = copy.deepcopy(self.critic)

        self.agent_params = list(mac.parameters())
        self.critic_params = list(self.critic.parameters())
        self.params = self.agent_params + self.critic_params

        self.agent_optimiser = RMSprop(params=self.agent_params, lr=args.lr, alpha=args.optim_alpha, eps=args.optim_eps)
        self.critic_optimiser = RMSprop(params=self.critic_params, lr=args.critic_lr, alpha=args.optim_alpha, eps=args.optim_eps)

    def train(self, batch: EpisodeBatch, t_env: int, episode_num: int):
        # Get the relevant quantities
        bs = batch.batch_size
        max_t = batch.max_seq_length
        rewards = batch["reward"][:, :-1]
        actions = batch["actions"][:, :]
        terminated = batch["terminated"][:, :-1].float()
        mask = batch["filled"][:, :-1].float()
        mask[:, 1:] = mask[:, 1:] * (1 - terminated[:, :-1])
        avail_actions = batch["avail_actions"][:, :-1]

        critic_mask = mask.clone()

        mask = mask.repeat(1, 1, self.n_agents).view(-1)

        q_vals, critic_train_stats = self._train_critic(batch, rewards, terminated, actions, avail_actions,
                                                        critic_mask, bs, max_t)

        actions = actions[:,:-1]

        mac_out = []
        self.mac.init_hidden(batch.batch_size)
        for t in range(batch.max_seq_length - 1):
            agent_outs = self.mac.forward(batch, t=t)
            mac_out.append(agent_outs)
        mac_out = th.stack(mac_out, dim=1)  # Concat over time

        # Mask out unavailable actions, renormalise (as in action selection)
        # modify
        if self.args.legal_action:
            mac_out[avail_actions == 0] = 0
        mac_out = mac_out/mac_out.sum(dim=-1, keepdim=True)
        # modify
        if self.args.legal_action:
            mac_out[avail_actions == 0] = 0

        # Calculated baseline
        q_vals = q_vals.reshape(-1, self.n_actions)
        pi = mac_out.view(-1, self.n_actions)
        baseline = (pi * q_vals).sum(-1).detach()

        # Calculate policy grad with mask
        q_taken = th.gather(q_vals, dim=1, index=actions.reshape(-1, 1)).squeeze(1)
        pi_taken = th.gather(pi, dim=1, index=actions.reshape(-1, 1)).squeeze(1)
        pi_taken[mask == 0] = 1.0
        log_pi_taken = th.log(pi_taken)

        advantages = (q_taken - baseline).detach()

        coma_loss = - ((advantages * log_pi_taken) * mask).sum() / mask.sum()

        # Optimise agents
        self.agent_optimiser.zero_grad()
        coma_loss.backward()
        grad_norm = th.nn.utils.clip_grad_norm_(self.agent_params, self.args.grad_norm_clip)
        self.agent_optimiser.step()

        if (self.critic_training_steps - self.last_target_update_step) / self.args.target_update_interval >= 1.0:
            self._update_targets()
            self.last_target_update_step = self.critic_training_steps

        if t_env - self.log_stats_t >= self.args.learner_log_interval:
            ts_logged = len(critic_train_stats["critic_loss"])
            for key in ["critic_loss", "critic_grad_norm", "td_error_abs", "q_taken_mean", "target_mean"]:
                self.logger.log_stat(key, sum(critic_train_stats[key])/ts_logged, t_env)

            self.logger.log_stat("advantage_mean", (advantages * mask).sum().item() / mask.sum().item(), t_env)
            self.logger.log_stat("coma_loss", coma_loss.item(), t_env)
            self.logger.log_stat("agent_grad_norm", grad_norm, t_env)
            self.logger.log_stat("pi_max", (pi.max(dim=1)[0] * mask).sum().item() / mask.sum().item(), t_env)
            self.log_stats_t = t_env

    def _train_critic(self, batch, rewards, terminated, actions, avail_actions, mask, bs, max_t):
        # Optimise critic
        target_q_vals = self.target_critic(batch)[:, :]
        targets_taken = th.gather(target_q_vals, dim=3, index=actions).squeeze(3)

        # Calculate td-lambda targets
        targets = build_td_lambda_targets(rewards, terminated, mask, targets_taken, self.n_agents, self.args.gamma, self.args.td_lambda)

        q_vals = th.zeros_like(target_q_vals)[:, :-1]

        running_log = {
            "critic_loss": [],
            "critic_grad_norm": [],
            "td_error_abs": [],
            "target_mean": [],
            "q_taken_mean": [],
        }

        for t in reversed(range(rewards.size(1))):
            mask_t = mask[:, t].expand(-1, self.n_agents)
            if mask_t.sum() == 0:
                continue

            q_t = self.critic(batch, t)
            q_vals[:, t] = q_t.view(bs, self.n_agents, self.n_actions)
            q_taken = th.gather(q_t, dim=3, index=actions[:, t:t+1]).squeeze(3).squeeze(1)
            targets_t = targets[:, t]

            td_error = (q_taken - targets_t.detach())

            # 0-out the targets that came from padded data
            masked_td_error = td_error * mask_t

            # Normal L2 loss, take mean over actual data
            loss = (masked_td_error ** 2).sum() / mask_t.sum()
            self.critic_optimiser.zero_grad()
            loss.backward()
            grad_norm = th.nn.utils.clip_grad_norm_(self.critic_params, self.args.grad_norm_clip)
            self.critic_optimiser.step()
            self.critic_training_steps += 1

            running_log["critic_loss"].append(loss.item())
            running_log["critic_grad_norm"].append(grad_norm)
            mask_elems = mask_t.sum().item()
            running_log["td_error_abs"].append((masked_td_error.abs().sum().item() / mask_elems))
            running_log["q_taken_mean"].append((q_taken * mask_t).sum().item() / mask_elems)
            running_log["target_mean"].append((targets_t * mask_t).sum().item() / mask_elems)

        return q_vals, running_log

    def _update_targets(self):
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.logger.console_logger.info("Updated target network")

    def cuda(self):
        self.mac.cuda()
        self.critic.cuda()
        self.target_critic.cuda()

    def save_models(self, path):
        self.mac.save_models(path)
        th.save(self.critic.state_dict(), "{}/critic.th".format(path))
        th.save(self.agent_optimiser.state_dict(), "{}/agent_opt.th".format(path))
        th.save(self.critic_optimiser.state_dict(), "{}/critic_opt.th".format(path))

    def load_models(self, path):
        self.mac.load_models(path)
        self.critic.load_state_dict(th.load("{}/critic.th".format(path), map_location=lambda storage, loc: storage))
        # Not quite right but I don't want to save target networks
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.agent_optimiser.load_state_dict(th.load("{}/agent_opt.th".format(path), map_location=lambda storage, loc: storage))
        self.critic_optimiser.load_state_dict(th.load("{}/critic_opt.th".format(path), map_location=lambda storage, loc: storage))
class COMALearner:
    def __init__(self, mac, scheme, logger, args):
        self.args = args
        self.n_agents = args.n_agents
        self.n_actions = args.n_actions
        self.mac = mac
        self.logger = logger
        self.Mode = str(self.args.running_mode)

        self.last_target_update_step = 0
        self.critic_training_steps = 0

        self.log_stats_t = -self.args.learner_log_interval - 1

        self.critic = COMACritic(scheme, args)
        self.target_critic = copy.deepcopy(self.critic)

        self.agent_params = list(mac.parameters())
        #print("self.agent_params=",self.agent_params)
        self.critic_params = list(self.critic.parameters())
        self.params = self.agent_params + self.critic_params

        self.agent_optimiser = RMSprop(params=self.agent_params,
                                       lr=args.lr,
                                       alpha=args.optim_alpha,
                                       eps=args.optim_eps)
        self.critic_optimiser = RMSprop(params=self.critic_params,
                                        lr=args.critic_lr,
                                        alpha=args.optim_alpha,
                                        eps=args.optim_eps)

    def train(self, batch: EpisodeBatch, t_env: int, episode_num: int):
        # Get the relevant quantities
        bs = batch.batch_size
        #print("episode batch=",EpisodeBatch)
        #print("batch=",batch,"--------------------------------------------------------------------------")
        #print("batch[intrinsic_reward]=",batch["intrinsic_reward"],"--------------------------------------------------------------------------")
        #print("batch[reward]=",batch["reward"],"--------------------------------------------------------------------------")
        #print("shape of batch[reward]=",batch["actions"].shape,"--------------------------------------------------------------------------")
        max_t = batch.max_seq_length

        rewards = batch["reward"][:, :-1]
        #print("rewards =",rewards.shape)
        #print("len rewards =",len(rewards))
        actions = batch["actions"][:, :]
        #print("actions =",actions.shape)
        terminated = batch["terminated"][:, :-1].float()
        mask = batch["filled"][:, :-1].float()
        mask[:, 1:] = mask[:, 1:] * (1 - terminated[:, :-1])
        #print("mask =",mask.shape)
        #print("len mask =",len(mask))
        avail_actions = batch["avail_actions"][:, :-1]

        critic_mask = mask.clone()

        mask = mask.repeat(1, 1, self.n_agents).view(-1)
        #print("mask2 =",mask.shape)

        q_vals, critic_train_stats = self._train_critic(
            batch, rewards, terminated, actions, avail_actions, critic_mask,
            bs, max_t)
        #print("q_vals =",q_vals.shape)
        actions = actions[:, :-1]
        #print("actions2 =",actions.shape)

        mac_out = []
        self.mac.init_hidden(batch.batch_size)
        for t in range(batch.max_seq_length - 1):
            agent_outs = self.mac.forward(batch, t=t)
            #print("t=",t,"agent_outs=",agent_outs)
            mac_out.append(agent_outs)
        mac_out = th.stack(mac_out, dim=1)  # Concat over time
        #print("mac_out=",mac_out.shape)
        #print("mac_out shape =",mac_out.size())

        # Mask out unavailable actions, renormalise (as in action selection)
        mac_out[avail_actions == 0] = 0
        mac_out = mac_out / mac_out.sum(dim=-1, keepdim=True)
        mac_out[avail_actions == 0] = 0
        #print("mac_out2=",mac_out.shape)
        #print("mac_out shape2 =",mac_out.size())

        # Calculated baseline
        q_vals = q_vals.reshape(-1, self.n_actions)
        pi = mac_out.view(-1, self.n_actions)
        baseline = (pi * q_vals).sum(-1).detach()
        #print("baseline=",baseline.shape)

        # Calculate policy grad with mask
        q_taken = th.gather(q_vals, dim=1, index=actions.reshape(-1,
                                                                 1)).squeeze(1)
        pi_taken = th.gather(pi, dim=1, index=actions.reshape(-1,
                                                              1)).squeeze(1)
        pi_taken[mask == 0] = 1.0
        log_pi_taken = th.log(pi_taken)

        advantages = th.FloatTensor([0.0])
        #torch.clamp(a, min=-0.5, max=0.5)
        advantages = (q_taken - baseline).detach()
        #print("advantages",advantages)
        ##################################################### individual Intrinsic Reward
        advantages = advantages.reshape(-1)
        if self.Mode == "2":
            int_adv = batch["intrinsic_reward"][:, :-1, :].reshape(-1)
            #print("int_adv",int_adv)
            clip_ratio = 2

            for t in range(len(advantages)):
                #print("adv shape =",advantages[t])
                #print("int_adv shape =",int_adv[t])
                int_adv_clipped = th.clamp(int_adv[t],
                                           min=clip_ratio * -advantages[t],
                                           max=clip_ratio * advantages[t])
                advantages[t] = advantages[t] + int_adv_clipped

        #print("advantages after",advantages)

        ##################################################### Combined Intrinsic Reward
        #print("batchzzzz = ",batch["intrinsic_reward"][:, :-1, 3])
        elif self.Mode == "5":
            #print("batch all =", th.cat((batch["intrinsic_reward"][:, :-1, :],batch["intrinsic_reward"][:, :-1, :],batch["intrinsic_reward"][:, :-1, :]),0).reshape(-1).shape)
            #print("batch soze =", batch["intrinsic_reward"][:, :-1, :].shape)
            #print("advantages  =", advantages.shape)
            #temp = []
            int_adv = batch["intrinsic_reward"][:, :-1, :]
            for p in range(self.n_agents - 1):
                int_adv = th.cat(
                    (int_adv, batch["intrinsic_reward"][:, :-1, :]), 0)
            int_adv = int_adv.view(-1)

            #int_adv = th.cat((batch["intrinsic_reward"][:, :-1, :],batch["intrinsic_reward"][:, :-1, :],batch["intrinsic_reward"][:, :-1, :]),1).reshape(-1)
            clip_ratio = 2
            for t in range(len(advantages)):
                #print("adv shape =",len(advantages))
                #print("int_adv shape =",len(int_adv))
                int_adv_clipped = th.clamp(int_adv[t],
                                           min=clip_ratio * -advantages[t],
                                           max=clip_ratio * advantages[t])
                advantages[t] = advantages[t] + int_adv_clipped
        else:
            pass

        #print("advantages after",advantages)
        ###################################################################################
        #print("int_adv",int_adv.shape)
        #print("batch[intrinsic_reward]",batch["intrinsic_reward"].shape)
        #print("batch[reward]",batch["reward"].shape)
        print("log_pi_taken", log_pi_taken.shape)
        print("advantages", advantages.shape)

        coma_loss = -((advantages * log_pi_taken) * mask).sum() / mask.sum()
        #print("self.agent_optimiser=",self.agent_optimiser)
        # Optimise agents
        #print(self.critic.parameters())
        #print(self.agent_optimiser.parameters())

        self.agent_optimiser.zero_grad()
        coma_loss.backward()
        grad_norm = th.nn.utils.clip_grad_norm_(self.agent_params,
                                                self.args.grad_norm_clip)
        self.agent_optimiser.step()

        if (self.critic_training_steps - self.last_target_update_step
            ) / self.args.target_update_interval >= 1.0:
            self._update_targets()
            self.last_target_update_step = self.critic_training_steps

        if t_env - self.log_stats_t >= self.args.learner_log_interval:
            ts_logged = len(critic_train_stats["critic_loss"])
            for key in [
                    "critic_loss", "critic_grad_norm", "td_error_abs",
                    "q_taken_mean", "target_mean"
            ]:
                self.logger.log_stat(key,
                                     sum(critic_train_stats[key]) / ts_logged,
                                     t_env)

            self.logger.log_stat("advantage_mean",
                                 (advantages * mask).sum().item() /
                                 mask.sum().item(), t_env)
            self.logger.log_stat("coma_loss", coma_loss.item(), t_env)
            self.logger.log_stat("agent_grad_norm", grad_norm, t_env)
            self.logger.log_stat("pi_max",
                                 (pi.max(dim=1)[0] * mask).sum().item() /
                                 mask.sum().item(), t_env)
            self.log_stats_t = t_env

    def _train_critic(self, batch, rewards, terminated, actions, avail_actions,
                      mask, bs, max_t):
        # Optimise critic
        #print("batch obs =",batch["obs"][0][0])
        target_q_vals = self.target_critic(batch)[:, :]
        #print("target_q_vals=",target_q_vals)
        #print("shape target_q_vals=",target_q_vals.shape)
        #print("batch obs =",batch["obs"])
        #print("size batch obs =",batch["obs"].size())
        #print("rewards", rewards)
        #print("size of rewards", rewards.shape)
        targets_taken = th.gather(target_q_vals, dim=3,
                                  index=actions).squeeze(3)

        # Calculate td-lambda targets
        targets = build_td_lambda_targets(rewards, terminated, mask,
                                          targets_taken, self.n_agents,
                                          self.args.gamma, self.args.td_lambda)
        #print("targets=",targets)

        q_vals = th.zeros_like(target_q_vals)[:, :-1]

        running_log = {
            "critic_loss": [],
            "critic_grad_norm": [],
            "td_error_abs": [],
            "target_mean": [],
            "q_taken_mean": [],
        }

        for t in reversed(range(rewards.size(1))):
            #print("mask_t before=",mask[:, t])
            mask_t = mask[:, t].expand(-1, self.n_agents)
            #print("mask_t after=",mask_t)
            if mask_t.sum() == 0:
                continue

            q_t = self.critic(batch, t)  # may be implement in here
            #print("batch check what inside =",batch)
            #print("q_t=",q_t)
            q_vals[:, t] = q_t.view(bs, self.n_agents, self.n_actions)
            #print("q_vals=",q_vals)
            #print("q_vals shpae=",q_vals.shape)
            q_taken = th.gather(q_t, dim=3,
                                index=actions[:,
                                              t:t + 1]).squeeze(3).squeeze(1)
            #print("q_taken=",q_taken)
            targets_t = targets[:, t]
            #print("targets_t=",targets_t)

            td_error = (q_taken - targets_t.detach())

            # 0-out the targets that came from padded data
            masked_td_error = td_error * mask_t

            # Normal L2 loss, take mean over actual data
            loss = (masked_td_error**2).sum() / mask_t.sum()
            self.critic_optimiser.zero_grad()
            loss.backward()
            grad_norm = th.nn.utils.clip_grad_norm_(self.critic_params,
                                                    self.args.grad_norm_clip)
            self.critic_optimiser.step()
            self.critic_training_steps += 1

            running_log["critic_loss"].append(loss.item())
            running_log["critic_grad_norm"].append(grad_norm)
            mask_elems = mask_t.sum().item()
            running_log["td_error_abs"].append(
                (masked_td_error.abs().sum().item() / mask_elems))
            running_log["q_taken_mean"].append(
                (q_taken * mask_t).sum().item() / mask_elems)
            running_log["target_mean"].append(
                (targets_t * mask_t).sum().item() / mask_elems)

        return q_vals, running_log

    def _update_targets(self):
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.logger.console_logger.info("Updated target network")

    def cuda(self):
        self.mac.cuda()
        self.critic.cuda()
        self.target_critic.cuda()

    def save_models(self, path):
        self.mac.save_models(path)
        th.save(self.critic.state_dict(), "{}/critic.th".format(path))
        th.save(self.agent_optimiser.state_dict(),
                "{}/agent_opt.th".format(path))
        th.save(self.critic_optimiser.state_dict(),
                "{}/critic_opt.th".format(path))

    def load_models(self, path):
        self.mac.load_models(path)
        self.critic.load_state_dict(
            th.load("{}/critic.th".format(path),
                    map_location=lambda storage, loc: storage))
        # Not quite right but I don't want to save target networks
        self.target_critic.load_state_dict(self.critic.state_dict())
        self.agent_optimiser.load_state_dict(
            th.load("{}/agent_opt.th".format(path),
                    map_location=lambda storage, loc: storage))
        self.critic_optimiser.load_state_dict(
            th.load("{}/critic_opt.th".format(path),
                    map_location=lambda storage, loc: storage))