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Farama-Foundation / Gymnasium

An API standard for single-agent reinforcement learning environments, with popular reference environments and related utilities (formerly Gym)
https://gymnasium.farama.org
MIT License
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[Question] Ant action space discrepancy #1035

Closed Velythyl closed 6 months ago

Velythyl commented 6 months ago

Question

In the old gym lib, the documentation for the action space of Ant-v4 is differently reported: https://www.gymlibrary.dev/environments/mujoco/ant/

Theirs also matches the brax ordering: https://github.com/google/brax/blob/main/brax/envs/ant.py

In contrast, gymnasium reports a different ordering: https://gymnasium.farama.org/environments/mujoco/ant/

This seems weird: why is the gymnasium ordering different? Is it misreported/a bug in the documentation? Or did the gymnasium authors change the ordering?

Kallinteris-Andreas commented 6 months ago

From the model file: https://github.com/Farama-Foundation/Gymnasium/blob/d1964978f14ea57479e797dadc91cbc437793de1/gymnasium/envs/mujoco/assets/ant.xml#L71-L80

The correct order is in gymnasium's documentation

Brax documentation is wrong because it copied the old version from gym which was wrong

Velythyl commented 6 months ago

Hey @Kallinteris-Andreas thanks for your answer, you're totally right! I'm now in the process of contacting the brax team for them to fix their doc as well