# Can anyone help with cross correlation error in Simulink?

I am sorry if I say any thing silly. I have a vector x below and trying to implement correlation with itself (lets say x2) in Simulink, but getting error. I am getting all zeros in result of my output vector. Kindly can some one please help me out in it. Thanks in advance.

ts=1*10^-9;
t=0*10^-9:ts:150*10^-9;
fc=1*10^6;
yi=154*10^-9:ts:2000*10^-9;
y=yi*0;
xi=2*sin(2*pi*fc*t);
x=[xi y];
x2=x;
z=xcorr(x2,x);

• You don't show us what xi is, but y is definitely zero. I would guess that xi is also zero. Nov 23 '15 at 11:21
• @MattL. Thanks for your comment.I am so sorry I forgot to add xi its given now.Its not zero. xi=2*sin(2*pifct); Nov 23 '15 at 15:48

The edited code in your question should not result in an all-zero vector. Of course, since x contains many zeros, the autocorrelation also has many zeros, but it's non-zero in its center portion (i.e., around index $2000$).
Also note that you don't need to define a second identical vector to compute the autocorrelation. You can use the command z = xcorr(x);