how to plot auto correlation and cross correlation function in a single figure?

17 views (last 30 days)
while plotting the ACf and CCF i didnt get the negative side of Auto correlation fucntion. I am getting only positive side only.
x=sin(2*pi*f/fs*t);
y=cos(2*pi*f/fs*t);
[ACF,Lags,Bounds] = autocorr(x,nLags,nSTDs);
[XCF,Lag,Bound] = crosscorr(x,y,nLags,nSTDs);
plot(Lags,ACF);
hold on
plot(Lag,XCF);
grid on
i getting output like given figure. Help me to get the negative side of the ACF.
  2 Comments
vinod kumar govindu
vinod kumar govindu on 20 Jan 2017
what we have to do for getting response at negative lags also? I am new to the matlab and dsp.

Sign in to comment.

Answers (1)

David J. Mack
David J. Mack on 20 Jan 2017
Edited: David J. Mack on 20 Jan 2017
The negative autocorrelation is the same as the positive as you use the same signal for the correlation. So if you want to pretend there is a negative part:
plot([-Lags(end:-1:1) Lags],[ACF(end:-1:1) ACF]);
Greetings, David

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!