function p = v(q)
% V(Q). Extracts the vector component 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))

if ispure(q)
    p = q;
else
    p = quaternion(x(q), y(q), z(q));
end