Unstable behavior in vector_vector_rotation

[Matthew Spellings]

When given two vectors that are opposite each other, vector_vector_rotation fails due to the degeneracy of that operation. I think people typically check whether the dot product is close to +- 1 and use a special case for that.

>>> import rowan
>>> rowan.vector_vector_rotation((0, 0, 1), (0, 0, -1))
array([6.123234e-17,          nan,          nan,          nan])

[Vyas Ramasubramani]

Thanks for reporting Matt! I'll look into this early next week or so.

[Vyas Ramasubramani]

Finalize solution and close Issue #3

→ <<cset 10b201944e96>>