`scipy.spatial.transform._rigid_transform:RigidTransform.as_dual_quat`

source: build-install/usr/lib/python3.14/site-packages/scipy/spatial/transform/_rigid_transform.py:1249

Signature

def as_dual_quat(self, *, scalar_first: bool = False) → Array

Summary

Return the dual quaternion representation of the transform.

Extended Summary

Unit dual quaternions encode orientation in a real unit quaternion and translation in a dual quaternion. There is a double cover, i.e., the unit dual quaternions q and -q represent the same transform.

Parameters

scalar_first : bool, optional: Whether the scalar component goes first or last in the two individual quaternions that represent the real and the dual part. Default is False, i.e. the scalar-last order is used.

Returns

dual_quat : numpy.ndarray, shape (..., 8): Unit dual quaternion vectors with the same leading dimensions as the transform. The real part is stored in the first four components and the dual part in the last four components.

Examples

from scipy.spatial.transform import RigidTransform as Tf
import numpy as np

✓

Get identity dual quaternion (we use scalar-last by default):

Tf.identity().as_dual_quat()

✓

array([0., 0., 0., 1., 0., 0., 0., 0.])

When we want to use the scalar-first convention, we use the argument:

Tf.identity().as_dual_quat(scalar_first=True)

✓

array([1., 0., 0., 0., 0., 0., 0., 0.])

Aliases

scipy.spatial.transform.RigidTransform.as_dual_quat