Help me understand my FFT output?

1 view (last 30 days)
C A on 4 Oct 2022
Answered: Image Analyst on 4 Oct 2022
I have two signals and I want to know if they have a natural oscillation. But I don't know if I mistook the signal noise for oscillations and decided to get the fast Fourier transform of my signals.
Here is what I see,
I am not sure what is going on with the green curve.
Here is my code:
plot(AgeBins1,Xidx2,'g','DisplayName','Signal 2','LineWidth',2);
Xidx2f = fft(Xidx2);
plot(AgeBins1,Xidx2f,'g','DisplayName','Signal 1','LineWidth',2);

Answers (1)

Image Analyst
Image Analyst on 4 Oct 2022
Hard to say exactly but it looks like your green signal is sort of like a signal multiplied by a rectangular pulse or triangle wave. So the "true" signal will be convolved with something like a sinc function, which will give rise to the periodic ripples on your "true" signal.





Community Treasure Hunt

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

Start Hunting!

Translated by