I should mention that I do get a second peak in the frequency at around 200 Hz, which is exactly what I want. I just want to get rid of the maximum peak occurring at 0 Hz...
FFT is finding a max amplitude at 0 Hz
8 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
Aimie
el 28 de Jun. de 2012
Comentada: Iftakharul alam
el 28 de Jul. de 2020
Can anyone explain why fft is giving a maximum amplitude at 0 Hz if the actual signal is pretty clear?
In my code, x is the signal as a function of time and r = length(x):
NFFT = 2^nextpow2(r);
X = fft(x,NFFT)/r;
Fs = 1/dt; % sampling frequency
f = Fs/2*linspace(0,1,NFFT/2+1); % frequency
A = 2*abs(X(1:NFFT/2+1)); % ampitude spectrum
Respuesta aceptada
Honglei Chen
el 28 de Jun. de 2012
You need to remove the DC component first. Just do
x = x-mean(x)
or
x = detrend(x)
before applying FFT
2 comentarios
Iftakharul alam
el 28 de Jul. de 2020
Dear Honglei Chen,
really appreciated to see you answer!
Thank you so much.
Más respuestas (0)
Ver también
Categorías
Más información sobre Fourier Analysis and Filtering en Help Center y File Exchange.
Productos
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!