FFT, PSD, and CSD

Fast Fourier Transform, Powder Spectral Density, and Cross Spectral Density

function Result=FFT(x, Fs)

Fast (Discrete) Fourier Transform of a Signal

inputs

x : input sequence (1*Ndata)

Fs: sampling frequency

outputs

Result structure consists of

Result.f : frequency (1*NumUniquePts)

Result.MX : amplitude (1*NumUniquePts)

Result.Arg : Phase Angle (1*NumUniquePts)

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function Result=PSD(x, Fs,window,N,p)

Power Spectral Density of a Signal (This function do the averaging for the spectral density)

inputs

x : input sequence (1*Ndata)

Fs: sampling frequency

window : window size

N: Number of windows

p: overlap ratio of windows

outputs

Result structure consists of

Result.f : frequency (1*NumUniquePts)

Result.MX : amplitude (1*NumUniquePts)

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function Result=CSD(x,y,Fs,window,N,p)

Cross Spectral Density of a Signal (This function do the averaging for the spectral density)

inputs

x : input sequence 1 (1*Ndata)

y : input sequence 2 (1*Ndata)

Fs: sampling frequency

window : window size

N: Number of windows

p: overlap ratio of windows

outputs

Result structure consists of

Result.f : frequency (1*NumUniquePts)

Result.MX : amplitude (1*NumUniquePts)

Result.Arg : Phase Angle (1*NumUniquePts)