scipy.spatial.transform.Rotation.

random#

classmethod Rotation.random(cls, num=None, rng=None)#

Generate uniformly distributed rotations.

Parameters:
numint or None, optional

Number of random rotations to generate. If None (default), then a single rotation is generated.

rng{None, int, numpy.random.Generator}, optional

If rng is passed by keyword, types other than numpy.random.Generator are passed to numpy.random.default_rng to instantiate a Generator. If rng is already a Generator instance, then the provided instance is used. Specify rng for repeatable function behavior.

If this argument is passed by position or random_state is passed by keyword, legacy behavior for the argument random_state applies:

  • If random_state is None (or numpy.random), the numpy.random.RandomState singleton is used.

  • If random_state is an int, a new RandomState instance is used, seeded with random_state.

  • If random_state is already a Generator or RandomState instance then that instance is used.

Changed in version 1.15.0: As part of the SPEC-007 transition from use of numpy.random.RandomState to numpy.random.Generator, this keyword was changed from random_state to rng. For an interim period, both keywords will continue to work, although only one may be specified at a time. After the interim period, function calls using the random_state keyword will emit warnings. The behavior of both random_state and rng are outlined above, but only the rng keyword should be used in new code.

Returns:
random_rotationRotation instance

Contains a single rotation if num is None. Otherwise contains a stack of num rotations.

See also

scipy.stats.special_ortho_group

Notes

This function is optimized for efficiently sampling random rotation matrices in three dimensions. For generating random rotation matrices in higher dimensions, see scipy.stats.special_ortho_group.

Examples

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

Sample a single rotation:

>>> R.random().as_euler('zxy', degrees=True)
array([-110.5976185 ,   55.32758512,   76.3289269 ])  # random

Sample a stack of rotations:

>>> R.random(5).as_euler('zxy', degrees=True)
array([[-110.5976185 ,   55.32758512,   76.3289269 ],  # random
       [ -91.59132005,  -14.3629884 ,  -93.91933182],
       [  25.23835501,   45.02035145, -121.67867086],
       [ -51.51414184,  -15.29022692, -172.46870023],
       [ -81.63376847,  -27.39521579,    2.60408416]])
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