Adding the quaternion-vector product as a utility function #250
Description
Is your feature request related to a problem? Please describe.
Many folks want to rotate vectors using quaternions. As mentioned in the docs,rotate_vectors does this but is not the most efficient way to rotate a single vector because it employs matrix multiplication. As noted in the docs, the formula
v' = v + 2 * r x (s * v + r x v) / m
should suffice. This is mentioned in a couple issues as well (e.g., #151).
Describe the solution you'd like
Can we add this as a utility function? Of course, it's easy for end-users to implement themselves, but I think this is common enough that it would enhance adoption.
Additional context
I can put in a PR and unit tests, should it be a worthwhile contribution.