A Short MATLAB Script for Spectrum Analysis or FFT

The following codes may be used for spectrum analysis for any vibration problems. The program is capable of isolating fundamental peaks from a noisy signal smoothly. It uses the MATLAB built-in Fast Fourier Transform (FFT) algorithm.

Codes for Spectrum Analysis (FFT):

NS=EFFORTS(:,1);                 % Data to Analyze
L=length(NS);
Fs=L;                            % Sample Rate
NFFT = 2^nextpow2(L);
F = Fs/2*linspace(0,1,NFFT/2+1);
win=hamming(L,'periodic');
Ywin=win.*NS;
X = fft(Ywin,NFFT)/L;            % MATLAB built-in FFT Algorithm
Xf=abs(X(1:NFFT/2+1));
Xf=Xf/max(Xf);                   % Normalizing Magnitude
plot(F,Xf)