sigmult.m

原名：数字信号处理基础及MATLAB实现,解压缩密码：[e-mail]

%序列乘
function [y,n] = sigmult(x1,n1,x2,n2)
%完成y(n)=x1(n)*x2(n)，其中，n1，n2表示序列的域，n1可以不等于n2；x1表示第一个序列；x2表示第二个序列。
% [y,n] = sigmult(x1,n1,x2,n2)
% y = product 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; % y1 = ones(1,length(n)); y2 = y1;
y1(find((n>=min(n1))&(n<=max(n1))==1))=x1; % x1 with duration of y
y2(find((n>=min(n2))&(n<=max(n2))==1))=x2; % x2 with duration of y
y = y1 .* y2; % sequence multiplication