jax.scipy.spatial.transform.Rotation.from_quat is missing scalar_first flag

[adam-hartshorne]

Description

The Rotation package of methods is supposed to mimic the scipy package. However the from_quat() method is missing the scalar_first flag. The as_quat() has it.

It also isn't clear from the documtation if the quaternion expected for this function is [x,y,z,w] or [w,x,y,z]

Edit:- It looks like it was committed to the main branch in September but now isn't there,

2ff26ff

System info (python version, jaxlib version, accelerator, etc.)

N/A

[jakevdp]

Hi - thanks for the report! jax.scipy.spatial.transform.Rotation is not under active development, and will be removed as soon as there is a viable alternative (refer to https://jax.readthedocs.io/en/latest/jep/18137-numpy-scipy-scope.html#scipy-spatial for a discussion of this).

That said, we will accept PRs making small changes and/or bug fixes if you're interested in adding support for this keyword.