ulab.fft – Frequency-domain functions

ulab.fft.fft(r: ulab.array, c: Optional[ulab.array] = None) → Tuple[ulab.array, ulab.array]

Parameters:

• r (ulab.array) – A 1-dimension array of values whose size is a power of 2
• c (ulab.array) – An optional 1-dimension array of values whose size is a power of 2, giving the complex part of the value

Return tuple (r, c):  

The real and complex parts of the FFT

Perform a Fast Fourier Transform from the time domain into the frequency domain

See also ~ulab.extras.spectrum, which computes the magnitude of the fft, rather than separately returning its real and imaginary parts.

ulab.fft.ifft(r: ulab.array, c: Optional[ulab.array] = None) → Tuple[ulab.array, ulab.array]

Parameters:

• r (ulab.array) – A 1-dimension array of values whose size is a power of 2
• c (ulab.array) – An optional 1-dimension array of values whose size is a power of 2, giving the complex part of the value

Return tuple (r, c):  

The real and complex parts of the inverse FFT

Perform an Inverse Fast Fourier Transform from the frequeny domain into the time domain

ulab.fft.spectrogram(r: ulab.array) → ulab.array

Parameters:r (ulab.array) – A 1-dimension array of values whose size is a power of 2

Computes the spectrum of the input signal. This is the absolute value of the (complex-valued) fft of the signal. This function is similar to scipy’s scipy.signal.spectrogram.