The package scipy.fftpack does two things: fast Fourier transforms, and differentiation and integration of periodic sequences.
Fast Fourier Transforms
The fft() function can be used by importing scipy, ie import scipy * However, other functions such as fft2 and the helper functions require the import of fftpack explicitly.
performs an Fourier transform on the array a and returns a complex array
- Inverse of fft
- Multi-dimensional FFT
- Inverse of fftn
- 2D FFT
- Inverse of fft2
- FFT of real periodic sequences
- Inverse of rfft
Differential and pseudo-differential operators
The helper functions have to be imported explicitly to be able to use them. That is import scipy * is not enough, import scipy.fftpack is required
- Shift zero-frequency component to the centre of the spectrum
- Inverse of fftshift