function [s] = getnumberfield(u)
% GETNUMBERFIELD - Returns the number field of the Lie group.
% function [s] = getnumberfield(u)

% WRITTEN BY       : Kenth Engų, 1999.04.04
% LAST MODIFIED BY : Kenth Engų, 1999.04.07

error(['Function not defined in class: ' class(u)]);
return;
