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/*
Copyright (C) 2011 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 "fmpz.h"
#include "fmpz_mat.h"
#include "fmpq_mat.h"
void
fmpq_mat_get_fmpz_mat_colwise(fmpz_mat_t num, fmpz * den, const fmpq_mat_t mat)
{
fmpz_t t, lcm;
slong i, j;
if (fmpq_mat_is_empty(mat))
return;
fmpz_init(t);
fmpz_init(lcm);
for (j = 0; j < mat->c; j++)
{
/* Compute common denominator of column */
fmpz_set(lcm, fmpq_mat_entry_den(mat, 0, j));
for (i = 1; i < mat->r; i++)
fmpz_lcm(lcm, lcm, fmpq_mat_entry_den(mat, i, j));
if (den != NULL)
fmpz_set(den + j, lcm);
/* Rescale numerators in column */
if (fmpz_is_one(lcm))
{
for (i = 0; i < mat->r; i++)
fmpz_set(fmpz_mat_entry(num, i, j),
fmpq_mat_entry_num(mat, i, j));
}
else
{
for (i = 0; i < mat->r; i++)
{
fmpz_divexact(t, lcm, fmpq_mat_entry_den(mat, i, j));
fmpz_mul(fmpz_mat_entry(num, i, j),
fmpq_mat_entry_num(mat, i, j), t);
}
}
}
fmpz_clear(t);
fmpz_clear(lcm);
}