arb/acb_mat/test/t-exp_taylor_sum.c

/*=============================================================================

    This file is part of ARB.

    ARB is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    ARB is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with ARB; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

=============================================================================*/
/******************************************************************************

    Copyright (C) 2016 Fredrik Johansson

******************************************************************************/

#include "acb_mat.h"

int main()
{
    slong iter;
    flint_rand_t state;

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

    flint_randinit(state);

    for (iter = 0; iter < 500 * arb_test_multiplier(); iter++)
    {
        acb_mat_t A, S1, S2, S3;
        fmpz_t f;
        slong n, N, prec1, prec2;

        n = n_randint(state, 5);
        N = n_randint(state, 40);
        prec1 = 2 + n_randint(state, 200);
        prec2 = 2 + n_randint(state, 200);

        acb_mat_init(A, n, n);
        acb_mat_init(S1, n, n);
        acb_mat_init(S2, n, n);
        acb_mat_init(S3, n, n);
        fmpz_init(f);

        acb_mat_randtest(A, state, prec1, 10);
        acb_mat_randtest(S1, state, prec1, 10);
        acb_mat_randtest(S2, state, prec1, 10);

        acb_mat_exp_taylor_sum(S1, A, N, prec1);

        acb_mat_exp_taylor_sum(S2, A, N + 1, prec2);

        acb_mat_pow_ui(S3, A, N, prec2);
        fmpz_fac_ui(f, N);
        acb_mat_scalar_div_fmpz(S3, S3, f, prec2);
        acb_mat_add(S3, S3, S1, prec2);

        if (!acb_mat_overlaps(S2, S3))
        {
            flint_printf("FAIL\n\n");
            flint_printf("n = %wd, N = %wd\n", n, N);
            flint_printf("A = \n"); acb_mat_printd(A, 15); flint_printf("\n\n");
            flint_printf("S1 = \n"); acb_mat_printd(S1, 15); flint_printf("\n\n");
            flint_printf("S2 = \n"); acb_mat_printd(S2, 15); flint_printf("\n\n");
            flint_printf("S3 = \n"); acb_mat_printd(S3, 15); flint_printf("\n\n");
            abort();
        }

        acb_mat_exp_taylor_sum(A, A, N, prec1);

        if (!acb_mat_overlaps(A, S1))
        {
            flint_printf("FAIL (aliasing)\n\n");
            abort();
        }

        acb_mat_clear(A);
        acb_mat_clear(S1);
        acb_mat_clear(S2);
        acb_mat_clear(S3);
        fmpz_clear(f);
    }

    flint_randclear(state);
    flint_cleanup();
    flint_printf("PASS\n");
    return EXIT_SUCCESS;
}