skrobot.coordinates.math.quaternion_absolute_distance

skrobot.coordinates.math.quaternion_absolute_distance(q1, q2)

Return the absolute distance of quaternion.

Parameters:

• q1 (list or numpy.ndarray) –

• q2 (list or numpy.ndarray) – [w, x, y, z] order

Returns:

diff_theta – absolute distance of q1 and q2 in radian.

Return type:

float

Examples

>>> from skrobot.coordinates.math import quaternion_absolute_distance
>>> quaternion_absolute_distance([1, 0, 0, 0], [1, 0, 0, 0])
0.0
>>> quaternion_absolute_distance(
        [1, 0, 0, 0],
        [0, 0.7071067811865476, 0, 0.7071067811865476])
3.141592653589793
>>> quaternion_absolute_distance(
        [-1, 0, 0, 0],
        [0, 0.7071067811865476, 0, 0.7071067811865476])