1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
/*
Copyright (C) 2023 Jean Kieffer
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 "fmpz_mat.h"
#include "arb.h"
#include "arb_mat.h"
int
arb_mat_spd_get_fmpz_mat(fmpz_mat_t B, const arb_mat_t A, slong prec)
{
slong j, k;
slong g = arb_mat_nrows(A);
arb_t z;
int res = 1;
arb_init(z);
for (j = 0; (j < g) && res; j++)
{
for (k = j; (k < g) && res; k++)
{
res = arb_intersection(z, arb_mat_entry(A, j, k),
arb_mat_entry(A, k, j), prec);
arf_get_fmpz_fixed_si(fmpz_mat_entry(B, j, k), arb_midref(z), -prec);
fmpz_set(fmpz_mat_entry(B, k, j), fmpz_mat_entry(B, j, k));
}
}
res = res && fmpz_mat_is_spd(B);
arb_clear(z);
return res;
}