function [y,n] = sigadd(x1,n1,x2,n2)% implements y(n) = x1(n)+x2(n)% -----------------------------% [y,n] = sigadd(x1,n1,x2,n2)%   y = sum sequence over n, which includes n1 and n2%  x1 = first sequence over n1%  x2 = second sequence over n2 (n2 can be different from n1)%n = min(min(n1),min(n2)):max(max(n1),max(n2)); % duration of y(n)y1 = zeros(1,length(n)); y2 = y1;              % initializationy1(find((n>=min(n1))&(n<=max(n1))==1))=x1;     % x1 with duration of yy2(find((n>=min(n2))&(n<=max(n2))==1))=x2;     % x2 with duration of yy = y1+y2;                                     % sequence addition