fft_small_plan_struct, fft_small_plan_t
#include <flint/fft_small.h>fft_small_plan_structfft_small_plan_tA plan. The public fields are np (number of primes), depth (d), ztrunc (the transform truncation, 2^d for cyclic plans), the window zl, zh of a convolution of length zn, the coefficient bound bound_c \cdot 2^{\mathtt{bound\_e}}, and for integer plans the chunk size bits.
The other fields are the context R, the offset of the first prime in it, the transform contexts in use (those of R, or a private context direct_fft for a transform modulo n itself), the per-prime stride of the data in doubles (a multiple of 256), a sign flag, and the normalisation factors m[i] = (c_i 2^d)^{-1} \bmod p_i, where c_i is the reduced Chinese remainder cofactor (1 for one prime). The two-prime integer plans set m[i] to 1 and normalise during reconstruction.
Guides#
The FLINT team, “fft_small_plan_struct, fft_small_plan_t (fft_small.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/fft_small/fft_small_plan_struct.html (generated 2026-10-20).
@misc{flint-doc-fft-small-fft-small-plan-struct,
author = {{The FLINT team}},
title = {{fft\_small\_plan\_struct, fft\_small\_plan\_t (fft\_small.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/fft_small/fft_small_plan_struct.html},
note = {Generated 2026-10-20}
}