Why is Frame_skip for gymnasium mujoco environments set to zero?

[HiddeLekanne]

The default for these environments differs from environment to environment. If you set them all to zero, results become silently incomparable with other benchmarks which use the default values.

Also action_repeat = X is not necessarily equal to frame_skip = X. Mujoco Implementations use fixed step ODEs to solve their environments, meaning larger frame_skips result in larger (less accurate) steps.

[belerico]

Hi @HiddeLekanne, it was a leftover from a previous implementation: thanks for spotting out!
Regarding the frame_skip vs action_repeat:

• for mujoco (which can be instantiated with the sheeprl/configs/env/gym.yaml config changing the env.id field) we do not apply any frame_skip by default (w/o considering the frame_skip=0 leftover)
• for dmc we have the frame_skip parameter and I think this can be misleading: we can remove that parameter and if one wants to apply the action_repeat it will set the env.action_repeat>=1 field

[HiddeLekanne]

Ah I was just worried it was a design decision, and that the idea was to replace any frame_skip parameter with the action_repeat parameter. I am not doing any dmc anyways so that issue isn't on my radar.

Personally I am doing something with irregular timesteps and have added my own config args for that.

[belerico]

Beautiful! I'll have it removed asap
Thanks