add is_eval attribute to policy and set this attribute as well as train mode in appropriate places

tianshou/data/collector.py

@@ -318,6 +318,7 @@ class Collector:
         no_grad: bool = True,
         reset_before_collect: bool = False,
         gym_reset_kwargs: dict[str, Any] | None = None,
+        is_eval: bool = False,
     ) -> CollectStats:
         """Collect a specified number of steps or episodes.
 
@@ -334,6 +335,7 @@ class Collector:
             (The collector needs the initial obs and info to function properly.)
         :param gym_reset_kwargs: extra keyword arguments to pass into the environment's
             reset function. Only used if reset_before_collect is True.
+        :param is_eval: whether to collect data in evaluation mode.
 
         .. note::
 
@@ -356,6 +358,13 @@ class Collector:
         # S - number of surplus envs, i.e. envs that are ready but won't be used in the next iteration.
         #     Only used in n_episode case. Then, R becomes R-S.
 
+        # set the policy's modules to eval mode (this affects modules like dropout and batchnorm) and the policy
+        # evaluation mode (this affects the policy's behavior, i.e., whether to sample or use the mode depending on
+        # policy.deterministic_eval)
+        self.policy.eval()
+        pre_collect_is_eval = self.policy.is_eval
+        self.policy.is_eval = is_eval
+
         use_grad = not no_grad
         gym_reset_kwargs = gym_reset_kwargs or {}
 
@@ -568,6 +577,9 @@ class Collector:
             # reset envs and the _pre_collect fields
             self.reset_env(gym_reset_kwargs)  # todo still necessary?
 
+        # set the policy back to pre collect mode
+        self.policy.is_eval = pre_collect_is_eval
+
         return CollectStats.with_autogenerated_stats(
             returns=np.array(episode_returns),
             lens=np.array(episode_lens),
@@ -665,6 +677,7 @@ class AsyncCollector(Collector):
         no_grad: bool = True,
         reset_before_collect: bool = False,
         gym_reset_kwargs: dict[str, Any] | None = None,
+        is_eval: bool = False,
     ) -> CollectStats:
         """Collect a specified number of steps or episodes with async env setting.
 
@@ -686,6 +699,7 @@ class AsyncCollector(Collector):
             (The collector needs the initial obs and info to function properly.)
         :param gym_reset_kwargs: extra keyword arguments to pass into the environment's
             reset function. Defaults to None (extra keyword arguments)
+        :param is_eval: whether to collect data in evaluation mode.
 
         .. note::
 
@@ -694,6 +708,13 @@ class AsyncCollector(Collector):
 
         :return: A dataclass object
         """
+        # set the policy's modules to eval mode (this affects modules like dropout and batchnorm) and the policy
+        # evaluation mode (this affects the policy's behavior, i.e., whether to sample or use the mode depending on
+        # policy.deterministic_eval)
+        self.policy.eval()
+        pre_collect_is_eval = self.policy.is_eval
+        self.policy.is_eval = is_eval
+
         use_grad = not no_grad
         gym_reset_kwargs = gym_reset_kwargs or {}
 
@@ -902,6 +923,9 @@ class AsyncCollector(Collector):
         # persist for future collect iterations
         self._ready_env_ids_R = ready_env_ids_R
 
+        # set the policy back to pre collect mode
+        self.policy.is_eval = pre_collect_is_eval
+
         return CollectStats.with_autogenerated_stats(
             returns=np.array(episode_returns),
             lens=np.array(episode_lens),

tianshou/highlevel/experiment.py

@@ -335,10 +335,9 @@ class Experiment(ToStringMixin):
         env: BaseVectorEnv,
         render: float,
     ) -> None:
-        policy.eval()
         collector = Collector(policy, env)
         collector.reset()
-        result = collector.collect(n_episode=num_episodes, render=render)
+        result = collector.collect(n_episode=num_episodes, render=render, is_eval=True)
         assert result.returns_stat is not None  # for mypy
         assert result.lens_stat is not None  # for mypy
         log.info(

tianshou/policy/base.py

@@ -225,6 +225,8 @@ class BasePolicy(nn.Module, Generic[TTrainingStats], ABC):
         self.action_scaling = action_scaling
         self.action_bound_method = action_bound_method
         self.lr_scheduler = lr_scheduler
+        # whether the policy is in evaluation mode
+        self.is_eval = False  # TODO: remove in favor of kwarg in compute_action/forward?
         self._compile()
 
     @property

tianshou/policy/modelfree/a2c.py

@@ -165,6 +165,9 @@ class A2CPolicy(PGPolicy[TA2CTrainingStats], Generic[TA2CTrainingStats]):  # typ
         *args: Any,
         **kwargs: Any,
     ) -> TA2CTrainingStats:
+        # set policy in train mode
+        self.train()
+
         losses, actor_losses, vf_losses, ent_losses = [], [], [], []
         split_batch_size = batch_size or -1
         for _ in range(repeat):

tianshou/policy/modelfree/bdq.py

@@ -163,6 +163,9 @@ class BranchingDQNPolicy(DQNPolicy[TBDQNTrainingStats]):
         return cast(ModelOutputBatchProtocol, result)
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TBDQNTrainingStats:
+        # set policy in train mode
+        self.train()
+
         if self._target and self._iter % self.freq == 0:
             self.sync_weight()
         self.optim.zero_grad()

tianshou/policy/modelfree/c51.py

@@ -117,6 +117,8 @@ class C51Policy(DQNPolicy[TC51TrainingStats], Generic[TC51TrainingStats]):
         return target_dist.sum(-1)
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TC51TrainingStats:
+        # set policy in train mode
+        self.train()
         if self._target and self._iter % self.freq == 0:
             self.sync_weight()
         self.optim.zero_grad()

tianshou/policy/modelfree/discrete_sac.py

@@ -107,10 +107,7 @@ class DiscreteSACPolicy(SACPolicy[TDiscreteSACTrainingStats]):
     ) -> Batch:
         logits_BA, hidden_BH = self.actor(batch.obs, state=state, info=batch.info)
         dist = Categorical(logits=logits_BA)
-        if self.deterministic_eval and not self.training:
+        act_B = dist.mode if self.deterministic_eval and self.is_eval else dist.sample()
-            act_B = dist.mode
-        else:
-            act_B = dist.sample()
         return Batch(logits=logits_BA, act=act_B, state=hidden_BH, dist=dist)
 
     def _target_q(self, buffer: ReplayBuffer, indices: np.ndarray) -> torch.Tensor:
@@ -127,6 +124,9 @@ class DiscreteSACPolicy(SACPolicy[TDiscreteSACTrainingStats]):
         return target_q.sum(dim=-1) + self.alpha * dist.entropy()
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TDiscreteSACTrainingStats:  # type: ignore
+        # set policy in train mode
+        self.train()
+
         weight = batch.pop("weight", 1.0)
         target_q = batch.returns.flatten()
         act = to_torch(batch.act[:, np.newaxis], device=target_q.device, dtype=torch.long)

tianshou/policy/modelfree/dqn.py

@@ -210,6 +210,8 @@ class DQNPolicy(BasePolicy[TDQNTrainingStats], Generic[TDQNTrainingStats]):
         return cast(ModelOutputBatchProtocol, result)
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TDQNTrainingStats:
+        # set policy in train mode
+        self.train()
         if self._target and self._iter % self.freq == 0:
             self.sync_weight()
         self.optim.zero_grad()

tianshou/policy/modelfree/fqf.py

@@ -153,6 +153,8 @@ class FQFPolicy(QRDQNPolicy[TFQFTrainingStats]):
         return cast(FQFBatchProtocol, result)
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TFQFTrainingStats:
+        # set policy in train mode
+        self.train()
         if self._target and self._iter % self.freq == 0:
             self.sync_weight()
         weight = batch.pop("weight", 1.0)

tianshou/policy/modelfree/iqn.py

@@ -131,6 +131,8 @@ class IQNPolicy(QRDQNPolicy[TIQNTrainingStats]):
         return cast(QuantileRegressionBatchProtocol, result)
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TIQNTrainingStats:
+        # set policy in train mode
+        self.train()
         if self._target and self._iter % self.freq == 0:
             self.sync_weight()
         self.optim.zero_grad()

tianshou/policy/modelfree/pg.py

@@ -197,10 +197,7 @@ class PGPolicy(BasePolicy[TPGTrainingStats], Generic[TPGTrainingStats]):
         # the action_dist_input_BD in that case is a tuple of loc_B, scale_B and needs to be unpacked
         dist = self.dist_fn(action_dist_input_BD)
 
-        if self.deterministic_eval and not self.training:
+        act_B = dist.mode if self.deterministic_eval and self.is_eval else dist.sample()
-            act_B = dist.mode
-        else:
-            act_B = dist.sample()
         # act is of dimension BA in continuous case and of dimension B in discrete
         result = Batch(logits=action_dist_input_BD, act=act_B, state=hidden_BH, dist=dist)
         return cast(DistBatchProtocol, result)
@@ -214,6 +211,9 @@ class PGPolicy(BasePolicy[TPGTrainingStats], Generic[TPGTrainingStats]):
         *args: Any,
         **kwargs: Any,
     ) -> TPGTrainingStats:
+        # set policy in train mode
+        self.train()
+
         losses = []
         split_batch_size = batch_size or -1
         for _ in range(repeat):

tianshou/policy/modelfree/ppo.py

@@ -151,6 +151,9 @@ class PPOPolicy(A2CPolicy[TPPOTrainingStats], Generic[TPPOTrainingStats]):  # ty
         *args: Any,
         **kwargs: Any,
     ) -> TPPOTrainingStats:
+        # set policy in train mode
+        self.train()
+
         losses, clip_losses, vf_losses, ent_losses = [], [], [], []
         split_batch_size = batch_size or -1
         for step in range(repeat):

tianshou/policy/modelfree/qrdqn.py

@@ -105,6 +105,8 @@ class QRDQNPolicy(DQNPolicy[TQRDQNTrainingStats], Generic[TQRDQNTrainingStats]):
         return super().compute_q_value(logits.mean(2), mask)
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TQRDQNTrainingStats:
+        # set policy in train mode
+        self.train()
         if self._target and self._iter % self.freq == 0:
             self.sync_weight()
         self.optim.zero_grad()

tianshou/policy/modelfree/redq.py

@@ -153,7 +153,7 @@ class REDQPolicy(DDPGPolicy[TREDQTrainingStats]):
     ) -> Batch:
         (loc_B, scale_B), h_BH = self.actor(batch.obs, state=state, info=batch.info)
         dist = Independent(Normal(loc_B, scale_B), 1)
-        if self.deterministic_eval and not self.training:
+        if self.deterministic_eval and self.is_eval:
             act_B = dist.mode
         else:
             act_B = dist.rsample()

tianshou/policy/modelfree/sac.py

@@ -175,7 +175,7 @@ class SACPolicy(DDPGPolicy[TSACTrainingStats], Generic[TSACTrainingStats]):  # t
     ) -> DistLogProbBatchProtocol:
         (loc_B, scale_B), hidden_BH = self.actor(batch.obs, state=state, info=batch.info)
         dist = Independent(Normal(loc=loc_B, scale=scale_B), 1)
-        if self.deterministic_eval and not self.training:
+        if self.deterministic_eval and self.is_eval:
             act_B = dist.mode
         else:
             act_B = dist.rsample()
@@ -213,6 +213,9 @@ class SACPolicy(DDPGPolicy[TSACTrainingStats], Generic[TSACTrainingStats]):  # t
         )
 
     def learn(self, batch: RolloutBatchProtocol, *args: Any, **kwargs: Any) -> TSACTrainingStats:  # type: ignore
+        # set policy in train mode
+        self.train()
+
         # critic 1&2
         td1, critic1_loss = self._mse_optimizer(batch, self.critic, self.critic_optim)
         td2, critic2_loss = self._mse_optimizer(batch, self.critic2, self.critic2_optim)

tianshou/trainer/base.py

@@ -269,7 +269,6 @@ class BaseTrainer(ABC):
             assert self.episode_per_test is not None
             assert not isinstance(self.test_collector, AsyncCollector)  # Issue 700
             test_result = test_episode(
-                self.policy,
                 self.test_collector,
                 self.test_fn,
                 self.start_epoch,
@@ -309,9 +308,6 @@ class BaseTrainer(ABC):
             if self.stop_fn_flag:
                 raise StopIteration
 
-        # set policy in train mode
-        self.policy.train()
-
         progress = tqdm.tqdm if self.show_progress else DummyTqdm
 
         # perform n step_per_epoch
@@ -395,7 +391,6 @@ class BaseTrainer(ABC):
         assert self.test_collector is not None
         stop_fn_flag = False
         test_stat = test_episode(
-            self.policy,
             self.test_collector,
             self.test_fn,
             self.epoch,
@@ -468,7 +463,6 @@ class BaseTrainer(ABC):
         ):
             assert self.test_collector is not None
             test_result = test_episode(
-                self.policy,
                 self.test_collector,
                 self.test_fn,
                 self.epoch,
@@ -481,8 +475,6 @@ class BaseTrainer(ABC):
                 should_stop_training = True
                 self.best_reward = test_result.returns_stat.mean
                 self.best_reward_std = test_result.returns_stat.std
-            else:
-                self.policy.train()
         return result, should_stop_training
 
     # TODO: move moving average computation and logging into its own logger

tianshou/trainer/utils.py

@@ -11,12 +11,10 @@ from tianshou.data import (
     SequenceSummaryStats,
     TimingStats,
 )
-from tianshou.policy import BasePolicy
 from tianshou.utils import BaseLogger
 
 
 def test_episode(
-    policy: BasePolicy,
     collector: Collector,
     test_fn: Callable[[int, int | None], None] | None,
     epoch: int,
@@ -27,10 +25,9 @@ def test_episode(
 ) -> CollectStats:
     """A simple wrapper of testing policy in collector."""
     collector.reset(reset_stats=False)
-    policy.eval()
     if test_fn:
         test_fn(epoch, global_step)
-    result = collector.collect(n_episode=n_episode)
+    result = collector.collect(n_episode=n_episode, is_eval=True)
     if reward_metric:  # TODO: move into collector
         rew = reward_metric(result.returns)
         result.returns = rew