fix qvalue mask_action error for obs_next (#310)

* fix #309
* remove for-loop in dqn expl_noise

test/discrete/test_qrdqn.py

@@ -17,7 +17,7 @@ from tianshou.data import Collector, VectorReplayBuffer, PrioritizedVectorReplay
 def get_args():
     parser = argparse.ArgumentParser()
     parser.add_argument('--task', type=str, default='CartPole-v0')
-    parser.add_argument('--seed', type=int, default=1)
+    parser.add_argument('--seed', type=int, default=0)
     parser.add_argument('--eps-test', type=float, default=0.05)
     parser.add_argument('--eps-train', type=float, default=0.1)
     parser.add_argument('--buffer-size', type=int, default=20000)
@@ -134,7 +134,6 @@ def test_qrdqn(args=get_args()):
 def test_pqrdqn(args=get_args()):
     args.prioritized_replay = True
     args.gamma = .95
-    args.seed = 1
     test_qrdqn(args)
 
 

tianshou/env/venvs.py

@@ -287,9 +287,9 @@ class BaseVectorEnv(gym.Env):
 
     def normalize_obs(self, obs: np.ndarray) -> np.ndarray:
         """Normalize observations by statistics in obs_rms."""
-        clip_max = 10.0  # this magic number is from openai baselines
-        # see baselines/common/vec_env/vec_normalize.py#L10
         if self.obs_rms and self.norm_obs:
+            clip_max = 10.0  # this magic number is from openai baselines
+            # see baselines/common/vec_env/vec_normalize.py#L10
             obs = (obs - self.obs_rms.mean) / np.sqrt(self.obs_rms.var + self.__eps)
             obs = np.clip(obs, -clip_max, clip_max)
         return obs

tianshou/policy/modelfree/c51.py

@@ -1,6 +1,6 @@
 import torch
 import numpy as np
-from typing import Any, Dict
+from typing import Any, Dict, Optional
 
 from tianshou.policy import DQNPolicy
 from tianshou.data import Batch, ReplayBuffer
@@ -57,14 +57,13 @@ class C51Policy(DQNPolicy):
         )
         self.delta_z = (v_max - v_min) / (num_atoms - 1)
 
-    def _target_q(
+    def _target_q(self, buffer: ReplayBuffer, indice: np.ndarray) -> torch.Tensor:
-        self, buffer: ReplayBuffer, indice: np.ndarray
-    ) -> torch.Tensor:
         return self.support.repeat(len(indice), 1)  # shape: [bsz, num_atoms]
 
-    def compute_q_value(self, logits: torch.Tensor) -> torch.Tensor:
+    def compute_q_value(
-        """Compute the q value based on the network's raw output logits."""
+        self, logits: torch.Tensor, mask: Optional[np.ndarray]
-        return (logits * self.support).sum(2)
+    ) -> torch.Tensor:
+        return super().compute_q_value((logits * self.support).sum(2), mask)
 
     def _target_dist(self, batch: Batch) -> torch.Tensor:
         if self._target:

tianshou/policy/modelfree/dqn.py

@@ -73,13 +73,13 @@ class DQNPolicy(BasePolicy):
 
     def _target_q(self, buffer: ReplayBuffer, indice: np.ndarray) -> torch.Tensor:
         batch = buffer[indice]  # batch.obs_next: s_{t+n}
-        # target_Q = Q_old(s_, argmax(Q_new(s_, *)))
+        result = self(batch, input="obs_next")
         if self._target:
-            a = self(batch, input="obs_next").act
+            # target_Q = Q_old(s_, argmax(Q_new(s_, *)))
             target_q = self(batch, model="model_old", input="obs_next").logits
-            target_q = target_q[np.arange(len(a)), a]
         else:
-            target_q = self(batch, input="obs_next").logits.max(dim=1)[0]
+            target_q = result.logits
+        target_q = target_q[np.arange(len(result.act)), result.act]
         return target_q
 
     def process_fn(
@@ -95,8 +95,14 @@ class DQNPolicy(BasePolicy):
             self._gamma, self._n_step, self._rew_norm)
         return batch
 
-    def compute_q_value(self, logits: torch.Tensor) -> torch.Tensor:
+    def compute_q_value(
-        """Compute the q value based on the network's raw output logits."""
+        self, logits: torch.Tensor, mask: Optional[np.ndarray]
+    ) -> torch.Tensor:
+        """Compute the q value based on the network's raw output and action mask."""
+        if mask is not None:
+            # the masked q value should be smaller than logits.min()
+            min_value = logits.min() - logits.max() - 1.0
+            logits = logits + to_torch_as(1 - mask, logits) * min_value
         return logits
 
     def forward(
@@ -140,15 +146,10 @@ class DQNPolicy(BasePolicy):
         obs = batch[input]
         obs_ = obs.obs if hasattr(obs, "obs") else obs
         logits, h = model(obs_, state=state, info=batch.info)
-        q = self.compute_q_value(logits)
+        q = self.compute_q_value(logits, getattr(obs, "mask", None))
         if not hasattr(self, "max_action_num"):
             self.max_action_num = q.shape[1]
-        act: np.ndarray = to_numpy(q.max(dim=1)[1])
+        act = to_numpy(q.max(dim=1)[1])
-        if hasattr(obs, "mask"):
-            # some of actions are masked, they cannot be selected
-            q_: np.ndarray = to_numpy(q)
-            q_[~obs.mask] = -np.inf
-            act = q_.argmax(axis=1)
         return Batch(logits=logits, act=act, state=h)
 
     def learn(self, batch: Batch, **kwargs: Any) -> Dict[str, float]:
@@ -169,10 +170,11 @@ class DQNPolicy(BasePolicy):
 
     def exploration_noise(self, act: np.ndarray, batch: Batch) -> np.ndarray:
         if not np.isclose(self.eps, 0.0):
-            for i in range(len(act)):
+            bsz = len(act)
-                if np.random.rand() < self.eps:
+            rand_mask = np.random.rand(bsz) < self.eps
-                    q_ = np.random.rand(self.max_action_num)
+            q = np.random.rand(bsz, self.max_action_num)  # [0, 1]
-                    if hasattr(batch["obs"], "mask"):
+            if hasattr(batch.obs, "mask"):
-                        q_[~batch["obs"].mask[i]] = -np.inf
+                q += batch.obs.mask
-                    act[i] = q_.argmax()
+            rand_act = q.argmax(axis=1)
+            act[rand_mask] = rand_act[rand_mask]
         return act

tianshou/policy/modelfree/qrdqn.py

@@ -1,8 +1,8 @@
 import torch
 import warnings
 import numpy as np
-from typing import Any, Dict
 import torch.nn.functional as F
+from typing import Any, Dict, Optional
 
 from tianshou.policy import DQNPolicy
 from tianshou.data import Batch, ReplayBuffer
@@ -61,9 +61,10 @@ class QRDQNPolicy(DQNPolicy):
         next_dist = next_dist[np.arange(len(a)), a, :]
         return next_dist  # shape: [bsz, num_quantiles]
 
-    def compute_q_value(self, logits: torch.Tensor) -> torch.Tensor:
+    def compute_q_value(
-        """Compute the q value based on the network's raw output logits."""
+        self, logits: torch.Tensor, mask: Optional[np.ndarray]
-        return logits.mean(2)
+    ) -> torch.Tensor:
+        return super().compute_q_value(logits.mean(2), mask)
 
     def learn(self, batch: Batch, **kwargs: Any) -> Dict[str, float]:
         if self._target and self._iter % self._freq == 0: