weldx.transformations.WXRotation.mean

WXRotation.mean(self, weights=None)

Get the mean of the rotations.

Parameters:

weights (array_like shape (N,), optional) – Weights describing the relative importance of the rotations. If None (default), then all values in weights are assumed to be equal.

Returns:

mean – Object containing the mean of the rotations in the current instance.

Return type:

Rotation instance

Notes

The mean used is the chordal L2 mean (also called the projected or induced arithmetic mean). If p is a set of rotations with mean m, then m is the rotation which minimizes (weights[:, None, None] * (p.as_matrix() - m.as_matrix())**2).sum().

Examples

>>> from scipy.spatial.transform import Rotation as R
>>> r = R.from_euler('zyx', [[0, 0, 0],
...                          [1, 0, 0],
...                          [0, 1, 0],
...                          [0, 0, 1]], degrees=True)
>>> r.mean().as_euler('zyx', degrees=True)
array([0.24945696, 0.25054542, 0.24945696])