function yn_out = isunix()
%ISUNIX True for the UNIX version of MATLAB.
%   ISUNIX returns 1 for UNIX versions of MATLAB and 0 otherwise.

%   Copyright 1984-2000 The MathWorks, Inc.
%   $Revision: 1.11 $  $Date: 2000/05/24 21:28:05 $

persistent yn;
if isempty(yn)
        %  The only non-Unix platform is the PC
        yn = ~strcmp(computer,'PCWIN');
end
yn_out = yn;
