scipy.spatial.transform.Rotation.from_rotvec#

classmethod Rotation.from_rotvec(cls, rotvec, degrees=False)#

Initialize from rotation vectors.

A rotation vector is a 3 dimensional vector which is co-directional to the axis of rotation and whose norm gives the angle of rotation [1].

Parameters:

rotvecarray_like, shape (N, 3) or (3,): A single vector or a stack of vectors, where rot_vec[i] gives the ith rotation vector.
degreesbool, optional: If True, then the given magnitudes are assumed to be in degrees. Default is False.

New in version 1.7.0.

Returns:

rotationRotation instance: Object containing the rotations represented by input rotation vectors.

References

[1]

https://en.wikipedia.org/wiki/Axis%E2%80%93angle_representation#Rotation_vector

Examples

>>> from scipy.spatial.transform import Rotation as R
>>> import numpy as np

Initialize a single rotation:

>>> r = R.from_rotvec(np.pi/2 * np.array([0, 0, 1]))
>>> r.as_rotvec()
array([0.        , 0.        , 1.57079633])
>>> r.as_rotvec().shape
(3,)

Initialize a rotation in degrees, and view it in degrees:

>>> r = R.from_rotvec(45 * np.array([0, 1, 0]), degrees=True)
>>> r.as_rotvec(degrees=True)
array([ 0., 45.,  0.])

Initialize multiple rotations in one object:

>>> r = R.from_rotvec([
... [0, 0, np.pi/2],
... [np.pi/2, 0, 0]])
>>> r.as_rotvec()
array([[0.        , 0.        , 1.57079633],
       [1.57079633, 0.        , 0.        ]])
>>> r.as_rotvec().shape
(2, 3)

It is also possible to have a stack of a single rotaton:

>>> r = R.from_rotvec([[0, 0, np.pi/2]])
>>> r.as_rotvec().shape
(1, 3)