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/*
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.h"
#include "fmpz_mat.h"
#include "acb_theta.h"
void
sp2gz_block_diag(fmpz_mat_t mat, const fmpz_mat_t U)
{
slong g = sp2gz_dim(mat);
fmpz_mat_t D, zero;
fmpz_t den;
fmpz_mat_init(D, g, g);
fmpz_mat_init(zero, g, g);
fmpz_init(den);
fmpz_mat_inv(D, den, U);
fmpz_mat_transpose(D, D);
if (!fmpz_is_one(den))
{
fmpz_neg(den, den);
fmpz_mat_neg(D, D);
}
sp2gz_set_blocks(mat, U, zero, zero, D);
fmpz_mat_clear(D);
fmpz_mat_clear(zero);
fmpz_clear(den);
}