pytransform3d.rotations.axis_angle_from_quaternion

pytransform3d.rotations.axis_angle_from_quaternion(q)

Compute axis-angle from quaternion.

This operation is called logarithmic map.

We usually assume active rotations.

Parameters:

qarray-like, shape (4,)

Unit quaternion to represent rotation: (w, x, y, z)

Returns:

aarray, shape (4,)

Axis of rotation and rotation angle: (x, y, z, angle). The angle is constrained to [0, pi) so that the mapping is unique.