Clarification on observation dimension

[jayaramreddy10]

When I debug code to get dataset for maze2d:

dataset = SequenceDataset()
batch = batchify(dataset[0])

Goal state in first sample of maze2d dataset =
tensor([[ 0.3114, 0.6512, 0.0737, -0.8078]], device='cuda:0')

Can you please clarify why the state is not just 2 dimensional (x, y), why is it 4 dimensional?

Thanks

[jannerm]

The first two dimensions are positions and then final two are velocities. You can verify this with:

>>> env=gym.make('maze2d-umaze-v0')
>>> env.reset()
array([2.98623863, 3.05874153, 0.08356836, 0.04921324])
>>> env.sim.data.qpos
array([2.98623863, 3.05874153])  ## matches obs[:2]
>>> env.sim.data.qvel
array([0.08356836, 0.04921324])  ## matches obs[2:]