First issue: Xf = fftshift(data); % NOT NEEDED Xf = fft(Xf); Xf = fftshift(Xf);. Do not fftshift the data before fft. The shift is only needed AFTER fft. ... <看更多>

I'm using the Signal Processing Toolbox in MATLAB to design a Butterworth low-pass filter. I'm told that my filter has been giving some ... ... <看更多>