function u = uminus(a) % + Unary plus. % (Quaternion overloading of standard Matlab function.) % 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)) u = a; % Since + does nothing, we can just return a.