C++ (Cpp) fmpz_mat_solve_dixon Examples

Example #1

File: det_divisor.c Project: goens/flint2

void
fmpz_mat_det_divisor(fmpz_t d, const fmpz_mat_t A)
{
    fmpz_mat_t X, B;
    fmpz_t t, u, v, mod;
    long i, n;
    int success;

    n = A->r;

    fmpz_mat_init(B, n, 1);
    fmpz_mat_init(X, n, 1);
    fmpz_init(t);
    fmpz_init(u);
    fmpz_init(v);
    fmpz_init(mod);

    /* Create a "random" vector */
    for (i = 0; i < n; i++)
    {
        fmpz_set_si(fmpz_mat_entry(B, i, 0), 2*(i % 2) - 1);
    }

    success = fmpz_mat_solve_dixon(X, mod, A, B);

    if (success)
    {
        fmpz_one(d);
        for (i = 0; i < n; i++)
        {
            fmpz_mul(t, d, fmpz_mat_entry(X, i, 0));
            fmpz_fdiv_qr(u, t, t, mod);
            if (!_fmpq_reconstruct_fmpz(u, v, t, mod))
            {
                printf("Exception: fmpz_mat_det_divisor: "
                       "rational reconstruction failed!\n");
                abort();
            }

            fmpz_mul(d, v, d);
        }
    }
    else
    {
        fmpz_zero(d);
    }

    fmpz_mat_clear(B);
    fmpz_mat_clear(X);
    fmpz_clear(t);
    fmpz_clear(u);
    fmpz_clear(v);
    fmpz_clear(mod);
}

Example #2

File: t-solve_dixon.c Project: clear731/lattice

int
main(void)
{
    fmpz_mat_t A, X, B, AX, AXm, Bm;
    fmpz_t mod;
    slong i, m, n, r;
    int success;

    FLINT_TEST_INIT(state);

    flint_printf("solve_dixon....");
    fflush(stdout);    

    for (i = 0; i < 100 * flint_test_multiplier(); i++)
    {
        m = n_randint(state, 20);
        n = n_randint(state, 20);

        fmpz_mat_init(A, m, m);
        fmpz_mat_init(B, m, n);
        fmpz_mat_init(Bm, m, n);
        fmpz_mat_init(X, m, n);
        fmpz_mat_init(AX, m, n);
        fmpz_mat_init(AXm, m, n);
        fmpz_init(mod);

        fmpz_mat_randrank(A, state, m, 1+n_randint(state, 2)*n_randint(state, 100));
        fmpz_mat_randtest(B, state, 1+n_randint(state, 2)*n_randint(state, 100));

        /* Dense */
        if (n_randint(state, 2))
            fmpz_mat_randops(A, state, 1+n_randint(state, 1 + m*m));

        success = fmpz_mat_solve_dixon(X, mod, A, B);

        fmpz_mat_set(AXm, X);

        fmpz_mat_mul(AX, A, AXm);

        fmpz_mat_scalar_mod_fmpz(AXm, AX, mod);
        fmpz_mat_scalar_mod_fmpz(Bm, B, mod);

        if (!fmpz_mat_equal(AXm, Bm) || !success)
        {
            flint_printf("FAIL:\n");
            flint_printf("AX != B!\n");
            flint_printf("A:\n"),      fmpz_mat_print_pretty(A),  flint_printf("\n");
            flint_printf("B:\n"),      fmpz_mat_print_pretty(B),  flint_printf("\n");
            flint_printf("X:\n"),      fmpz_mat_print_pretty(X),  flint_printf("\n");
            flint_printf("mod = "),    fmpz_print(mod),           flint_printf("\n");
            flint_printf("AX:\n"),     fmpz_mat_print_pretty(AX), flint_printf("\n");
            abort();
        }

        fmpz_mat_clear(A);
        fmpz_mat_clear(B);
        fmpz_mat_clear(Bm);
        fmpz_mat_clear(X);
        fmpz_mat_clear(AX);
        fmpz_mat_clear(AXm);
        fmpz_clear(mod);
    }

    /* Test singular systems */
    for (i = 0; i < 100 * flint_test_multiplier(); i++)
    {
        m = 1 + n_randint(state, 10);
        n = 1 + n_randint(state, 10);
        r = n_randint(state, m);

        fmpz_mat_init(A, m, m);
        fmpz_mat_init(B, m, n);
        fmpz_mat_init(X, m, n);
        fmpz_init(mod);

        fmpz_mat_randrank(A, state, r, 1+n_randint(state, 2)*n_randint(state, 100));
        fmpz_mat_randtest(B, state, 1+n_randint(state, 2)*n_randint(state, 100));

        /* Dense */
        if (n_randint(state, 2))
            fmpz_mat_randops(A, state, 1+n_randint(state, 1 + m*m));

        if (fmpz_mat_solve_dixon(X, mod, A, B) != 0)
        {
            flint_printf("FAIL:\n");
            flint_printf("singular system, returned nonzero\n");
            abort();
        }

        fmpz_mat_clear(A);
        fmpz_mat_clear(B);
        fmpz_mat_clear(X);
        fmpz_clear(mod);
    }

    FLINT_TEST_CLEANUP(state);
    
    flint_printf("PASS\n");
    return 0;
}