/*
Copyright (C) 2010 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_vec.h"
#include "fmpz_mat.h"
void
fmpz_mat_randrank(fmpz_mat_t mat, flint_rand_t state, slong rank,
flint_bitcnt_t bits)
{
slong i;
fmpz * diag;
if (rank < 0 || rank > mat->r || rank > mat->c)
{
flint_throw(FLINT_ERROR, "Exception (fmpz_mat_randrank). Impossible rank.\n");
}
diag = _fmpz_vec_init(rank);
for (i = 0; i < rank; i++)
fmpz_randtest_not_zero(&diag[i], state, bits);
fmpz_mat_randpermdiag(mat, state, diag, rank);
_fmpz_vec_clear(diag, rank);
}