Cross corelation

clc
close all
clear all
x=[1 4 5 6 0 0 0]
h=[8 6 3 1 0 0 0]
for i=1:7
    y(i)=0
    for j=1:4
        if(i-j+1>0)
            y(i)=y(i)+x(j)*h(i-j+1)
        else
        end
    end
end
stem(y)