Unit quaternion
^^^^^^^^^^^^^^^

.. autoclass:: spatialmath.quaternion.UnitQuaternion
   :members:
   :undoc-members:
   :show-inheritance:
   :inherited-members:
   :special-members: __mul__,  __truediv__, __add__, __sub__, __eq__, __ne__, __pow__, __init__
   :exclude-members: count, copy, index, sort, remove, arghandler, binop, unop,