anax2quat.m

Converts angle-axis rotation parameters into a quaternion.

Syntax

    q=anax2quat(rot_axis,rot_angle)

Parameters

    rot_axis -  cartesian direction vector given as a
                row or column with three real elements

    rot_angle - rotation angle in radians

Outputs

    q         - a structure with four fields q.u, q.i,
                q.j, q.k giving the four components of
                the quaternion

Notes

Both angle-axis and quaternion convention are numerically stable. This conversion has no singularities. See the notes on rotation conventions for the basic definitions of rotations in Spinach.

See also

euler2dcm.m, dcm2euler.m, wigner.m, dcm2wigner.m

Version 2.3, authors: Gareth Charnock, Ilya Kuprov