# tensorplay.fft

Source: https://www.tensorplay.cn/docs/fft.html

Discrete Fourier transforms and related functions.

## Fast Fourier Transforms

| tensorplay.fft._transforms.fft |Computes the one-dimensional discrete Fourier transform. |
| --- | --- |
| tensorplay.fft._transforms.ifft | Computes the one-dimensional inverse discrete Fourier transform. |
| tensorplay.fft._transforms.fft2 | Computes the two-dimensional discrete Fourier transform. |
| tensorplay.fft._transforms.ifft2 | Computes the two-dimensional inverse discrete Fourier transform. |
| tensorplay.fft._transforms.fftn | Computes the N-dimensional discrete Fourier transform over dim. |
| tensorplay.fft._transforms.ifftn | Computes the N-dimensional inverse discrete Fourier transform. |
| tensorplay.fft._transforms.rfft | Computes the one-dimensional FFT of real input, one-sided output. |
| tensorplay.fft._transforms.irfft | Computes the inverse of rfft(); n is the output length. |
| tensorplay.fft._transforms.rfft2 | Computes the two-dimensional FFT of real input. |
| tensorplay.fft._transforms.irfft2 | Computes the inverse of rfft2(). |
| tensorplay.fft._transforms.rfftn | N-dimensional FFT of real input; one-sided along the last listed dim. |
| tensorplay.fft._transforms.irfftn | Inverse of rfftn(); s[-1] is the real output size (default 2 * (input.size(dim[-1]) - 1)). |
| tensorplay.fft._transforms.hfft | Computes the 1-D FFT of a Hermitian-symmetric spectrum; real output. |
| tensorplay.fft._transforms.ihfft | Computes the inverse of hfft(); one-sided complex output. |
| tensorplay.fft._transforms.hfft2 | Two-dimensional FFT of a Hermitian-symmetric spectrum; real output. |
| tensorplay.fft._transforms.ihfft2 | Two-dimensional counterpart of ihfft(). |
| tensorplay.fft._transforms.hfftn | N-dimensional FFT of a Hermitian-symmetric spectrum; real output. |
| tensorplay.fft._transforms.ihfftn | Inverse of hfftn(): ihfft() along the final transformed dimension, then the inverse transform over the remaining dimensions. |

## Helper Functions

| tensorplay.fft._frequency.fftfreq |DFT sample frequencies (cycles/unit): [0, 1, ..., (n-1)//2, -(n//2), ..., -1] / (n*d). |
| --- | --- |
| tensorplay.fft._frequency.rfftfreq | Sample frequencies for rfft()/one-sided transforms: [0..n//2] / (n*d). |
| tensorplay.fft._frequency.fftshift | Re-orders an N-D FFT output so the zero-frequency term is centered. |
| tensorplay.fft._frequency.ifftshift | Inverse of fftshift(); rolls by (n + 1) // 2 (odd-safe). |