function y=subplus(x)
% SUBPLUS	Positive part.
%                              x , if  x>=0
%     y = subplus(x) := (x)  =               ,
%                          +   0 , if  x<=0
%
%  returns the positive part of  x . Used for computing truncated powers.

% C. de Boor / latest change: Nov.26, 88
% Copyright (c) 1990-92 by Carl de Boor and The MathWorks, Inc.


y=(x+abs(x))/2;
