/*
Copyright (C) 2023 Fredrik Johansson
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "gr_mat.h"
#include "gr_poly.h"
/* todo: algorithm selection */
int
_gr_mat_charpoly(gr_ptr cp, const gr_mat_t mat, gr_ctx_t ctx)
{
return _gr_mat_charpoly_berkowitz(cp, mat, ctx);
}
int gr_mat_charpoly(gr_poly_t cp, const gr_mat_t mat, gr_ctx_t ctx)
{
int status;
if (mat->r != mat->c)
return GR_DOMAIN;
gr_poly_fit_length(cp, mat->r + 1, ctx);
_gr_poly_set_length(cp, mat->r + 1, ctx);
status = _gr_mat_charpoly(cp->coeffs, mat, ctx);
_gr_poly_normalise(cp, ctx); /* only needed for the zero ring */
return status;
}