FFT Peak at Zero

Hello,

I am trying to plot the FFT for a data set I have. I keep getting a peak around zero and have problem with filtering. I also tried the detrend function, but I still don’t get a nice plot. I have attached my data set. I am planning to calculate FFT for the “roll” column from my data set. I appreciate your help.

[dpb]

The zero component in the FFT corresponds to the DC component of the signal...to remove, subtract mean(roll)

[Image Analyst]

Just what I was going to say, so put it down in the Answers section so you can get credit for it.

Answer 1

[Catalytic]

Apply fftshift to your spectrum to see it with DC centered in the plot.

   x=csvread('230.csv',1,0);
   
   rollSpectrum=fftshift(fft(x(:,2)));
   plot(abs(rollSpectrum))

[Mohamad Mossad]

about 8 months later, thanks :)