C++ (Cpp) arb_fac2_ui Examples

Example #1

File: t-fac2_ui.c Project: wbhart/arb

int main()
{
    slong iter;
    flint_rand_t state;

    flint_printf("fac2_ui....");
    fflush(stdout);

    flint_randinit(state);

    for (iter = 0; iter < 1000; iter++)
    {
        arb_t a, b, c;
        ulong n;
        slong prec1, prec2;

        prec1 = 2 + n_randint(state, 300);
        prec2 = 2 + n_randint(state, 300);

        arb_init(a);
        arb_init(b);
        arb_init(c);

        n = n_randtest(state);
        if (n + 1 == 0 || n + 2 == 0)
            n -= 2;

        arb_fac2_ui(a, n, prec1);
        arb_fac2_ui(b, n + 2, prec1);
        arb_mul_ui(c, a, n + 2, prec2);

        if (!arb_overlaps(b, c))
        {
            flint_printf("FAIL: overlap\n\n");
            flint_printf("a = "); arb_print(a); flint_printf("\n\n");
            flint_printf("b = "); arb_print(b); flint_printf("\n\n");
            flint_printf("c = "); arb_print(c); flint_printf("\n\n");
            abort();
        }

        arb_clear(a);
        arb_clear(b);
        arb_clear(c);
    }

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

Example #2

File: fac2_ui.c Project: jdemeyer/arb

void
arb_fac2_ui(arb_t res, ulong n, long prec)
{
    if (n % 2 == 0)
    {
        arb_fac_ui(res, n / 2, prec);
        arb_mul_2exp_si(res, res, n / 2);
    }
    else
    {
        arb_t t;
        arb_init(t);
        arb_fac2_ui(t, n - 1, prec + 5);
        arb_fac_ui(res, n, prec + 5);
        arb_div(res, res, t, prec);
        arb_clear(t);
    }
}