www.gusucode.com > MATLAB GUI设计的实例，学习用matlab设计界面的很好的参考资料 > matlab_GUI/sigadd.m

    function[y,n] = sigadd(x1,n1,x2,n2)
%信号加y(n) = x1(n) + x2(n)

n = [min(min(n1),min(n2)):0.01*pi:max(max(n1),max(n2))];
y1 = zeros(1,length(n));
y2 = zeros(1,length(n));
x2(1)=0;
y1(find((n >= min(n1))&(n <= max(n1)))) = x1;
y2([1,find((n >= min(n2))&(n <= max(n2)))]) = x2;
y = y1 + y2;