168 lines
4.7 KiB
C
168 lines
4.7 KiB
C
/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2012 Fredrik Johansson
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******************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <gmp.h>
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#include "flint.h"
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#include "nmod_vec.h"
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#include "nmod_mat.h"
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#include "ulong_extras.h"
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#include "perm.h"
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int check_rref_form(slong * perm, nmod_mat_t A, slong rank)
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{
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slong i, j, k, prev_pivot;
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/* bottom should be zero */
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for (i = rank; i < A->r; i++)
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for (j = 0; j < A->c; j++)
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if (nmod_mat_entry(A, i, j) != 0)
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return 0;
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prev_pivot = -1;
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for (i = 0; i < rank; i++)
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{
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for (j = 0; j < A->c; j++)
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{
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if (nmod_mat_entry(A, i, j) != 0)
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{
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/* pivot should have a higher column index than previous */
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if (j <= prev_pivot)
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return 0;
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/* column should be 0 ... 0 1 0 ... 0 */
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for (k = 0; k < rank; k++)
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if (nmod_mat_entry(A, k, j) != (i == k))
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return 0;
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prev_pivot = j;
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break;
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}
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}
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}
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return 1;
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}
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int
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main(void)
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{
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slong i;
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FLINT_TEST_INIT(state);
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flint_printf("rref....");
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fflush(stdout);
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for (i = 0; i < 1000 * flint_test_multiplier(); i++)
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{
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nmod_mat_t A, B, C, D;
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mp_limb_t mod;
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slong j, k, m, n, rank1, rank2;
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slong *perm;
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int equal;
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mp_limb_t c;
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mod = n_randtest_prime(state, 0);
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m = n_randint(state, 20);
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n = n_randint(state, 20);
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perm = _perm_init(2*m);
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nmod_mat_init(A, m, n, mod);
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nmod_mat_init(D, 2*m, n, mod);
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nmod_mat_randtest(A, state);
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nmod_mat_init_set(B, A);
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nmod_mat_init_set(C, A);
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rank1 = nmod_mat_rref(B);
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if (!check_rref_form(perm, B, rank1))
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{
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flint_printf("FAIL (malformed rref)\n");
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nmod_mat_print_pretty(A); flint_printf("\n\n");
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nmod_mat_print_pretty(B); flint_printf("\n\n");
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abort();
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}
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/* Concatenate the original matrix with the rref, scramble the rows,
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and check that the rref is the same */
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_perm_randtest(perm, 2 * m, state);
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for (j = 0; j < m; j++)
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{
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do { c = n_randint(state, mod); } while (c == 0);
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for (k = 0; k < n; k++)
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nmod_mat_entry(D, perm[j], k) =
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nmod_mul(nmod_mat_entry(A, j, k), c, A->mod);
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}
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for (j = 0; j < m; j++)
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{
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do { c = n_randint(state, mod); } while (c == 0);
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for (k = 0; k < n; k++)
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nmod_mat_entry(D, perm[m + j], k) =
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nmod_mul(nmod_mat_entry(B, j, k), c, A->mod);
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}
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rank2 = nmod_mat_rref(D);
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equal = (rank1 == rank2);
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if (equal)
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{
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for (j = 0; j < rank2; j++)
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for (k = 0; k < n; k++)
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equal = equal && (nmod_mat_entry(B, j, k) ==
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nmod_mat_entry(D, j, k));
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for (j = rank2; j < 2 * rank2; j++)
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for (k = 0; k < n; k++)
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equal = equal && (nmod_mat_entry(D, j, k) == 0);
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}
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if (!equal)
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{
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flint_printf("FAIL (rank1 = %wd, rank2 = %wd)!\n", rank1, rank2);
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nmod_mat_print_pretty(A); flint_printf("\n\n");
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nmod_mat_print_pretty(B); flint_printf("\n\n");
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nmod_mat_print_pretty(D); flint_printf("\n\n");
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abort();
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}
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_perm_clear(perm);
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nmod_mat_clear(A);
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nmod_mat_clear(B);
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nmod_mat_clear(C);
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nmod_mat_clear(D);
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}
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FLINT_TEST_CLEANUP(state);
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flint_printf("PASS\n");
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return 0;
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}
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