gr_mat_adjugate, gr_mat_adjugate_cofactor, gr_mat_adjugate_charpoly
#include <flint/gr_mat.h>Set adj to the adjugate of A and det to its determinant, so that \operatorname{adj}(A) A = A \operatorname{adj}(A) = \det(A) I. The cofactor version computes n^2 minors; the charpoly version evaluates (-1)^{n-1}(A^{n-1} + c_{n-1} A^{n-2} + \cdots + c_1 I) from the characteristic polynomial x^n + c_{n-1} x^{n-1} + \cdots + c_0 by rectangular splitting, with O(\sqrt{n}) matrix products. The default uses cofactors for n \le 5 and the characteristic polynomial otherwise. All versions are division-free when the characteristic polynomial is.
Guides#
The FLINT team, “gr_mat_adjugate, gr_mat_adjugate_cofactor, gr_mat_adjugate_charpoly (gr_mat.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/gr_mat/gr_mat_adjugate.html (generated 2026-10-20).
@misc{flint-doc-gr-mat-gr-mat-adjugate,
author = {{The FLINT team}},
title = {{gr\_mat\_adjugate, gr\_mat\_adjugate\_cofactor, gr\_mat\_adjugate\_charpoly (gr\_mat.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/gr_mat/gr_mat_adjugate.html},
note = {Generated 2026-10-20}
}