FLINT3.7.0-dev

ca_mat_dft

Synopsis#include <flint/ca_mat.h>
void ca_mat_dft(ca_mat_t res, int type, ca_ctx_t ctx)source

Sets res to a matrix of the discrete Fourier transform of length nn, the smaller of the two dimensions (along the larger dimension the entries repeat periodically). With ω=e2πi/n\omega = e^{2 \pi i / n}, the entries Aj,kA_{j,k} are ω−jk\omega^{-jk} for type = 0, ωjk/n\omega^{jk}/n for type 1, ω−jk/n\omega^{-jk}/\sqrt{n} for type 2 and ωjk/n\omega^{jk}/\sqrt{n} for type 3. Types 0 and 1 are inverse to each other, and so are types 2 and 3. The entries are elements of the cyclotomic field Q(ω)\mathbb{Q}(\omega) (and n\sqrt{n}).

Cite this page

The FLINT team, “ca_mat_dft (ca_mat.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/ca_mat/ca_mat_dft.html (generated 2026-11-02).