int
acb_modular_is_in_fundamental_domain(const acb_t z, const arf_t tol, long prec)
{
    arb_t t;
    arb_init(t);

    /* require re(w) + 1/2 >= 0 */
    arb_set_ui(t, 1);
    arb_mul_2exp_si(t, t, -1);
    arb_add(t, t, acb_realref(z), prec);
    arb_add_arf(t, t, tol, prec);
    if (!arb_is_nonnegative(t))
    {
        arb_clear(t);
        return 0;
    }

    /* require re(w) - 1/2 <= 0 */
    arb_set_ui(t, 1);
    arb_mul_2exp_si(t, t, -1);
    arb_sub(t, acb_realref(z), t, prec);
    arb_sub_arf(t, t, tol, prec);
    if (!arb_is_nonpositive(t))
    {
        arb_clear(t);
        return 0;
    }

    /* require |w| >= 1 - tol, i.e. |w| - 1 + tol >= 0 */
    acb_abs(t, z, prec);
    arb_sub_ui(t, t, 1, prec);
    arb_add_arf(t, t, tol, prec);
    if (!arb_is_nonnegative(t))
    {
        arb_clear(t);
        return 0;
    }

    arb_clear(t);
    return 1;
}
Example #2
0
int main()
{
    slong iter;
    flint_rand_t state;

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

    flint_randinit(state);

    for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
    {
        arb_t a, b, c, d;
        arf_t x;
        slong prec;

        arb_init(a);
        arb_init(b);
        arb_init(c);
        arb_init(d);
        arf_init(x);

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 100);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 100);
        arb_randtest_special(c, state, 1 + n_randint(state, 2000), 100);
        arf_randtest_special(x, state, 1 + n_randint(state, 2000), 100);

        prec = 2 + n_randint(state, 2000);

        arb_set_arf(b, x);
        arb_sub_arf(c, a, x, prec);
        arb_sub(d, a, b, prec);

        if (!arb_equal(c, d))
        {
            flint_printf("FAIL\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");
            flint_printf("d = "); arb_print(d); flint_printf("\n\n");
            abort();
        }

        arb_clear(a);
        arb_clear(b);
        arb_clear(c);
        arb_clear(d);
        arf_clear(x);
    }

    /* aliasing */
    for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
    {
        arb_t a, b, c;
        arf_t x;
        slong prec;

        arb_init(a);
        arb_init(b);
        arb_init(c);
        arf_init(x);

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 100);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 100);
        arb_randtest_special(c, state, 1 + n_randint(state, 2000), 100);
        arf_randtest_special(x, state, 1 + n_randint(state, 2000), 100);

        prec = 2 + n_randint(state, 2000);

        arb_set_arf(b, x);
        arb_sub_arf(c, a, x, prec);
        arb_sub_arf(a, a, x, prec);

        if (!arb_equal(a, c))
        {
            flint_printf("FAIL (aliasing)\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);
        arf_clear(x);
    }

    flint_randclear(state);
    flint_cleanup();
    flint_printf("PASS\n");
    return EXIT_SUCCESS;
}
Example #3
0
static void
acb_log_sin_pi_half(acb_t res, const acb_t z, slong prec, int upper)
{
    acb_t t, u, zmid;
    arf_t n;
    arb_t pi;

    acb_init(t);
    acb_init(u);
    acb_init(zmid);
    arf_init(n);
    arb_init(pi);

    arf_set(arb_midref(acb_realref(zmid)), arb_midref(acb_realref(z)));
    arf_set(arb_midref(acb_imagref(zmid)), arb_midref(acb_imagref(z)));

    arf_floor(n, arb_midref(acb_realref(zmid)));
    arb_sub_arf(acb_realref(zmid), acb_realref(zmid), n, prec);

    arb_const_pi(pi, prec);

    if (arf_cmpabs_2exp_si(arb_midref(acb_imagref(zmid)), 2) < 1)
    {
        acb_sin_pi(t, zmid, prec);
        acb_log(t, t, prec);
    }
    else  /* i*pi*(z-0.5) + log((1-exp(-2i*pi*z))/2) */
    {
        acb_mul_2exp_si(t, zmid, 1);
        acb_neg(t, t);

        if (upper)
            acb_conj(t, t);

        acb_exp_pi_i(t, t, prec);
        acb_sub_ui(t, t, 1, prec);
        acb_neg(t, t);

        acb_mul_2exp_si(t, t, -1);

        acb_log(t, t, prec);
        acb_one(u);
        acb_mul_2exp_si(u, u, -1);
        acb_sub(u, zmid, u, prec);
        if (upper)
            acb_conj(u, u);
        acb_mul_onei(u, u);
        acb_addmul_arb(t, u, pi, prec);
        if (upper)
            acb_conj(t, t);
    }

    if (upper)
        arb_submul_arf(acb_imagref(t), pi, n, prec);
    else
        arb_addmul_arf(acb_imagref(t), pi, n, prec);

    /* propagated error bound from the derivative pi cot(pi z) */
    if (!acb_is_exact(z))
    {
        mag_t zm, um;

        mag_init(zm);
        mag_init(um);

        acb_cot_pi(u, z, prec);
        acb_mul_arb(u, u, pi, prec);

        mag_hypot(zm, arb_radref(acb_realref(z)), arb_radref(acb_imagref(z)));
        acb_get_mag(um, u);
        mag_mul(um, um, zm);

        acb_add_error_mag(t, um);

        mag_clear(zm);
        mag_clear(um);
    }

    acb_set(res, t);

    acb_clear(t);
    acb_clear(u);
    acb_clear(zmid);
    arf_clear(n);
    arb_clear(pi);
}