# Creating and Stepping Environments Our tasks are `gymnax` environments and work with wrappers and code designed to work with `gymnax`. The following example demonstrates how to integrate POPGym Arcade into your code. ```python import popgym_arcade import jax # Create POMDP env variant env, env_params = popgym_arcade.make("BattleShipEasy", partial_obs=True) # Let's vectorize and compile the env # Note when you are training a policy, it is better to compile your policy_update rather than the env_step reset = jax.jit(jax.vmap(env.reset, in_axes=(0, None))) step = jax.jit(jax.vmap(env.step, in_axes=(0, 0, 0, None))) # Initialize four vectorized environments n_envs = 4 # Initialize PRNG keys key = jax.random.key(0) reset_keys = jax.random.split(key, n_envs) # Reset environments observation, env_state = reset(reset_keys, env_params) # Step the POMDP for t in range(10): # Propagate some randomness action_key, step_key = jax.random.split(jax.random.key(t)) action_keys = jax.random.split(action_key, n_envs) step_keys = jax.random.split(step_key, n_envs) # Pick actions at random actions = jax.vmap(env.action_space(env_params).sample)(action_keys) # Step the env to the next state # No need to reset after initial reset, gymnax automatically resets when done observation, env_state, reward, done, info = step(step_keys, env_state, actions, env_params) # POMDP and MDP variants share states # We can plug the POMDP states into the MDP and continue playing mdp, mdp_params = popgym_arcade.make("BattleShipEasy", partial_obs=False) mdp_reset = jax.jit(jax.vmap(mdp.reset, in_axes=(0, None))) mdp_step = jax.jit(jax.vmap(mdp.step, in_axes=(0, 0, 0, None))) action_keys = jax.random.split(jax.random.key(t + 1), n_envs) step_keys = jax.random.split(jax.random.key(t + 2), n_envs) markov_state, env_state, reward, done, info = mdp_step(step_keys, env_state, actions, mdp_params) ```