Fourier transforms

FFT related functions

pyvib.fft.fft(y, Fs, detrend='constant', hann=True, cons=True, debug=False)

The scaled amplitude frequency spectrum

Parameters

• y (float 1D array) – Signal you want FFT of.

• Fs (float) – Sampling frequency

• Detrend (string, optional) – Detrends the signal using scipy.signal.detrend - ‘constant’ to remove mean value - ‘linear’ to remove least squares fit - ‘none’ to do nothing

• hann (bool, optional) – Add a hanning window if true.

• cons (bool, optional) –

  Whether conservative part of the spectrum should be returned:

  • True returns Fs/2.56

  • False returns Fs/2.0

Returns

• Y (float 1D array) – FFT amplitude

• df (float) – Delta frequency

pyvib.fft.rawfft(y)

Raw FFT of the signal.

Parameters

• y (float 1D array) – Signal to get spectrum of

• Fs (float) – Sampling frequency in Hz

Returns

• Y (float 1D array) – Spectrum values

• df (float) – Delta frequency in Hz

pyvib.fft.rawifft(Y)

Raw inverse FFT

Parameters

Y (float 1D array) – Spectrum to inverse

Returns

y – Time domain signal

Return type

float 1D array