fft_radix2_twiddle, ifft_radix2_twiddle
Synopsis
#include <flint/fft.h>void fft_radix2_twiddle(mp_limb_t ** ii, mp_size_t is, mp_size_t n, flint_bitcnt_t w, mp_limb_t ** t1, mp_limb_t ** t2, mp_size_t ws, mp_size_t r, mp_size_t c, mp_size_t rs)sourcevoid ifft_radix2_twiddle(mp_limb_t ** ii, mp_size_t is, mp_size_t n, flint_bitcnt_t w, mp_limb_t ** t1, mp_limb_t ** t2, mp_size_t ws, mp_size_t r, mp_size_t c, mp_size_t rs)sourceAs fft_radix2 and ifft_radix2 on the entries ii[0], ii[is], …, ii[(2n - 1) is], with an extra twiddle: output k of the forward transform is multiplied by 2^{\mathit{ws} \cdot c \cdot (r + \mathit{rs} \cdot \mathrm{rev}(k))}, and input k of the inverse is divided by the same factor first.
Cite this page
The FLINT team, “fft_radix2_twiddle, ifft_radix2_twiddle (fft.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/fft/fft_radix2_twiddle.html (generated 2026-10-20).
@misc{flint-doc-fft-fft-radix2-twiddle,
author = {{The FLINT team}},
title = {{fft\_radix2\_twiddle, ifft\_radix2\_twiddle (fft.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/fft/fft_radix2_twiddle.html},
note = {Generated 2026-10-20}
}