def run()

in rlalgos/ppo/discrete_ppo.py [0:0]


    def run(self):
        self.learning_model = self._create_model()
        self.agent = self._create_agent(
            n_actions=self.n_actions, model=self.learning_model
        )

        # We create a batcher dedicated to evaluation
        model = copy.deepcopy(self.learning_model)
        self.evaluation_batcher = RL_Batcher(
            n_timesteps=self.config["max_episode_steps"],
            create_agent=self._create_agent,
            create_env=self._create_env,
            env_args={
                "n_envs": self.config["n_evaluation_envs"],
                "max_episode_steps": self.config["max_episode_steps"],
                "env_name": self.config["env_name"],
            },
            agent_args={"n_actions": self.n_actions, "model": model},
            n_processes=self.config["n_evaluation_processes"],
            seeds=[
                self.config["env_seed"] + k * 10
                for k in range(self.config["n_evaluation_processes"])
            ],
            agent_info=DictTensor({"stochastic": torch.tensor([True])}),
            env_info=DictTensor({}),
        )

        model = copy.deepcopy(self.learning_model)
        self.train_batcher = RL_Batcher(
            n_timesteps=self.config["ppo_timesteps"],
            create_agent=self._create_agent,
            create_env=self._create_train_env,
            env_args={
                "n_envs": self.config["n_envs"],
                "max_episode_steps": self.config["max_episode_steps"],
                "env_name": self.config["env_name"],
            },
            agent_args={"n_actions": self.n_actions, "model": model},
            n_processes=self.config["n_processes"],
            seeds=[
                self.config["env_seed"] + k * 10
                for k in range(self.config["n_processes"])
            ],
            agent_info=DictTensor({"stochastic": torch.tensor([True])}),
            env_info=DictTensor({}),
        )

        # Creation of the optimizer
        optimizer = torch.optim.Adam(
            self.learning_model.parameters(), lr=self.config["lr"]
        )

        # Training Loop:
        _start_time = time.time()
        self.iteration = 0

        # #We launch the evaluation batcher (in deterministic mode)
        n_episodes = (
            self.config["n_evaluation_processes"] * self.config["n_evaluation_envs"]
        )
        agent_info = DictTensor(
            {"stochastic": torch.tensor([False]).repeat(n_episodes)}
        )
        self.evaluation_batcher.reset(agent_info=agent_info)
        self.evaluation_batcher.execute()
        self.evaluation_iteration = self.iteration

        # Initialize the training batcher such that agents will start to acqire pieces of episodes
        self.train_batcher.update(self.learning_model.state_dict())
        n_episodes = self.config["n_envs"] * self.config["n_processes"]
        agent_info = DictTensor({"stochastic": torch.tensor([True]).repeat(n_episodes)})
        self.train_batcher.reset(agent_info=agent_info)

        while time.time() - _start_time < self.config["time_limit"]:
            self.train_batcher.execute()
            trajectories, n = self.train_batcher.get()
            assert n == self.config["n_envs"] * self.config["n_processes"]
            avg_reward = 0
            for K in range(self.config["k_epochs"]):
                optimizer.zero_grad()
                dt = self.get_loss(trajectories)
                [
                    self.logger.add_scalar("loss/" + k, dt[k].item(), self.iteration)
                    for k in dt.keys()
                ]

                # Computation of final loss
                ld = self.config["coef_critic"] * dt["critic_loss"]
                lr = self.config["coef_ppo"] * dt["a2c_loss"]
                le = self.config["coef_entropy"] * dt["entropy_loss"]

                floss = ld - le - lr
                floss.backward()
                if self.config["clip_grad"] > 0:
                    n = torch.nn.utils.clip_grad_norm_(
                        self.learning_model.parameters(), self.config["clip_grad"]
                    )
                    self.logger.add_scalar("grad_norm", n.item(), self.iteration)
                optimizer.step()
                self.iteration += 1

            cpu_parameters = self._state_dict(self.learning_model, torch.device("cpu"))
            self.train_batcher.update(cpu_parameters)
            self.iteration += 1

            evaluation_trajectories, n = self.evaluation_batcher.get(blocking=False)
            if not evaluation_trajectories is None:  # trajectories are available
                # Compute the cumulated reward
                cumulated_reward = (
                    (
                        evaluation_trajectories.trajectories["_observation/reward"]
                        * evaluation_trajectories.trajectories.mask()
                    )
                    .sum(1)
                    .mean()
                )
                self.logger.add_scalar(
                    "evaluation_reward",
                    cumulated_reward.item(),
                    self.evaluation_iteration,
                )
                print(
                    "At iteration %d, reward is %f"
                    % (self.evaluation_iteration, cumulated_reward.item())
                )
                # We reexecute the evaluation batcher (with same value of agent_info and same number of episodes)
                self.evaluation_batcher.update(self.learning_model.state_dict())
                self.evaluation_iteration = self.iteration
                n_episodes = (
                    self.config["n_evaluation_processes"]
                    * self.config["n_evaluation_envs"]
                )
                agent_info = DictTensor(
                    {"stochastic": torch.tensor([False]).repeat(n_episodes)}
                )
                self.evaluation_batcher.reset(agent_info=agent_info)
                self.evaluation_batcher.execute()