function r = y(q) % Y Extracts the y component of the vector part of a quaternion. % Copyright © 2005 Stephen J. Sangwine and Nicolas Le Bihan. % See the file : Copyright.m for further details. % error(nargchk(1, 1, nargin)), error(nargoutchk(0, 1, nargout)) % This function is written in terms of its private counterpart % so that the underlying representation of a quaternion is a % private aspect of the class. r = wye(q);