Fix models using scale_obs not being persistable (due to locally defined class)

examples/atari/atari_dqn_hl.py

@@ -27,7 +27,7 @@ from tianshou.utils.logging import datetime_tag
 def main(
     experiment_config: ExperimentConfig,
     task: str = "PongNoFrameskip-v4",
-    scale_obs: int = 0,
+    scale_obs: bool = False,
     eps_test: float = 0.005,
     eps_train: float = 1.0,
     eps_train_final: float = 0.05,

examples/atari/atari_iqn_hl.py

@@ -24,7 +24,7 @@ from tianshou.utils.logging import datetime_tag
 def main(
     experiment_config: ExperimentConfig,
     task: str = "PongNoFrameskip-v4",
-    scale_obs: int = 0,
+    scale_obs: bool = False,
     eps_test: float = 0.005,
     eps_train: float = 1.0,
     eps_train_final: float = 0.05,

examples/atari/atari_network.py

@@ -23,19 +23,26 @@ def layer_init(layer: nn.Module, std: float = np.sqrt(2), bias_const: float = 0.
     return layer
 
 
-def scale_obs(module: type[nn.Module], denom: float = 255.0) -> type[nn.Module]:
-    class scaled_module(module):
-        def forward(
-            self,
-            obs: np.ndarray | torch.Tensor,
-            state: Any | None = None,
-            info: dict[str, Any] | None = None,
-        ) -> tuple[torch.Tensor, Any]:
-            if info is None:
-                info = {}
-            return super().forward(obs / denom, state, info)
+class ScaledObsInputModule(torch.nn.Module):
+    def __init__(self, module: torch.nn.Module, denom: float = 255.0):
+        super().__init__()
+        self.module = module
+        self.denom = denom
+        self.output_dim = module.output_dim
 
-    return scaled_module
+    def forward(
+        self,
+        obs: np.ndarray | torch.Tensor,
+        state: Any | None = None,
+        info: dict[str, Any] | None = None,
+    ) -> tuple[torch.Tensor, Any]:
+        if info is None:
+            info = {}
+        return self.module.forward(obs / self.denom, state, info)
+
+
+def scale_obs(module: nn.Module, denom: float = 255.0) -> nn.Module:
+    return ScaledObsInputModule(module, denom=denom)
 
 
 class DQN(nn.Module):
@@ -238,8 +245,7 @@ class ActorFactoryAtariDQN(ActorFactory):
         self.features_only = features_only
 
     def create_module(self, envs: Environments, device: TDevice) -> Actor:
-        net_cls = scale_obs(DQN) if self.scale_obs else DQN
-        net = net_cls(
+        net = DQN(
             *envs.get_observation_shape(),
             envs.get_action_shape(),
             device=device,
@@ -247,6 +253,8 @@ class ActorFactoryAtariDQN(ActorFactory):
             output_dim=self.hidden_size,
             layer_init=layer_init,
         )
+        if self.scale_obs:
+            net = scale_obs(net)
         return Actor(net, envs.get_action_shape(), device=device, softmax_output=False).to(device)
 
 

examples/atari/atari_ppo.py

@@ -109,8 +109,7 @@ def test_ppo(args=get_args()):
     np.random.seed(args.seed)
     torch.manual_seed(args.seed)
     # define model
-    net_cls = scale_obs(DQN) if args.scale_obs else DQN
-    net = net_cls(
+    net = DQN(
         *args.state_shape,
         args.action_shape,
         device=args.device,
@@ -118,6 +117,8 @@ def test_ppo(args=get_args()):
         output_dim=args.hidden_size,
         layer_init=layer_init,
     )
+    if args.scale_obs:
+        net = scale_obs(net)
     actor = Actor(net, args.action_shape, device=args.device, softmax_output=False)
     critic = Critic(net, device=args.device)
     optim = torch.optim.Adam(ActorCritic(actor, critic).parameters(), lr=args.lr, eps=1e-5)

examples/atari/atari_sac_hl.py

@@ -24,7 +24,7 @@ from tianshou.utils.logging import datetime_tag
 def main(
     experiment_config: ExperimentConfig,
     task: str = "PongNoFrameskip-v4",
-    scale_obs: int = 0,
+    scale_obs: bool = False,
     buffer_size: int = 100000,
     actor_lr: float = 1e-5,
     critic_lr: float = 1e-5,