[Doc] Fix tutorials

ghstack-source-id: 6c91143
Pull Request resolved: #2560

Author: Vincent Moens

tutorials/sphinx-tutorials/torchrl_demo.py

@@ -415,11 +415,9 @@
     TransformedEnv,
 )
 
-base_env = GymEnv("Pendulum-v1", frame_skip=3, from_pixels=True, pixels_only=False)
+base_env = GymEnv("HalfCheetah-v4", frame_skip=3, from_pixels=True, pixels_only=False)
 env = TransformedEnv(base_env, Compose(NoopResetEnv(3), ToTensorImage()))
-env.append_transform(ObservationNorm(in_keys=["pixels"], loc=2, scale=1))
-
-###############################################################################
+env = env.append_transform(ObservationNorm(in_keys=["pixels"], loc=2, scale=1))
 
 env.reset()
 

tutorials/sphinx-tutorials/torchrl_envs.py

@@ -694,9 +694,11 @@ def env_make(env_name):
 
 make_env = EnvCreator(lambda: TransformedEnv(GymEnv("CartPole-v1"), VecNorm(decay=1.0)))
 env = ParallelEnv(3, make_env)
-make_env.state_dict()["_extra_state"]["td"]["observation_count"].fill_(0.0)
-make_env.state_dict()["_extra_state"]["td"]["observation_ssq"].fill_(0.0)
-make_env.state_dict()["_extra_state"]["td"]["observation_sum"].fill_(0.0)
+print("env state dict:")
+sd = TensorDict(make_env.state_dict())
+print(sd)
+# Zeroes all tensors
+sd *= 0
 
 tensordict = env.rollout(max_steps=5)