to_axes_angles

Orientation.to_axes_angles() → AxAngle

Return the unit quaternions as axis-angle vectors [Rowenhorst et al., 2015].

Returns:

ax

Axis-angle vectors with magnitude \(\theta\) equal to the angle of rotation.

See also

to_homochoric, to_rodrigues

Examples

A 3-fold rotation around the [111] axis

>>> from orix.quaternion import Quaternion
>>> Q = Quaternion([0.5, 0.5, 0.5, 0.5])
>>> ax = Q.to_axes_angles()
>>> ax
AxAngle (1,)
[[1.2092 1.2092 1.2092]]
>>> np.rad2deg(ax.angle)
array([120.])