Example #1
0
int main()
{
	long p = 1000;
	long d = 53;
	arb_t a, b, x, t;
	
	arb_init(a);
	arb_init(b);
	arb_init(x);
	arb_init(t);

	// a = 1 + 2 ^ -76
	arb_set_str(a, "2", p);
	arb_set_str(t, "-76", p);
	arb_pow(a, a, t, p);
	arb_set_str(t, "1", p);
	arb_add(a, t, a, p);
	printf("a   = "); arb_printd(a, d); printf("\n");

	// b = 4 ^ 38 + 0.5
	arb_set_str(b, "0.5", p);
	arb_ui_pow_ui(t, 4, 38, p);
	arb_add(b, t, b, p);
	printf("b   = "); arb_printd(b, d); printf("\n");

	// x = a ^ b
	arb_pow(x, a, b, p);
	printf("x   = "); arb_printd(x, d); printf("\n");
	arb_const_e(t, p);
	printf("e   = "); arb_printd(t, d); printf("\n");
	arb_sub(t, x, t, p);
	printf("x-e = "); arb_printd(t, d); printf("\n");

	printf("Computed with arb-%s\n", arb_version);

	arb_clear(a);
	arb_clear(b);
	arb_clear(x);
	arb_clear(t);
}
Example #2
0
static __inline__ void
zeta_coeff_k(zeta_bsplit_t S, slong k, slong n, slong s)
{
    arb_set_si(S->D, 2 * (n + k));
    arb_mul_si(S->D, S->D, n - k, ARF_PREC_EXACT);
    arb_set_si(S->Q1, k + 1);
    arb_mul_si(S->Q1, S->Q1, 2*k + 1, ARF_PREC_EXACT);

    if (k == 0)
    {
        arb_zero(S->A);
        arb_one(S->Q2);
    }
    else
    {
        arb_set_si(S->A, k % 2 ? 1 : -1);
        arb_mul(S->A, S->A, S->Q1, ARF_PREC_EXACT);
        arb_ui_pow_ui(S->Q2, k, s, ARF_PREC_EXACT);
    }

    arb_mul(S->Q3, S->Q1, S->Q2, ARF_PREC_EXACT);
    arb_zero(S->B);
    arb_set(S->C, S->Q1);
}
Example #3
0
int main()
{
    slong iter;
    flint_rand_t state;

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

    flint_randinit(state);

    /* test multiplication theorem */
    for (iter = 0; iter < 1000 * arb_test_multiplier(); iter++)
    {
        acb_t x, t, res1, res2;
        ulong n, m, k;
        slong prec;

        n = n_randint(state, 50);
        m = 1 + n_randint(state, 5);
        prec = 2 + n_randint(state, 200);

        acb_init(x);
        acb_init(t);
        acb_init(res1);
        acb_init(res2);

        acb_randtest(x, state, 2 + n_randint(state, 200), 20);
        acb_randtest(res1, state, 2 + n_randint(state, 200), 20);

        acb_mul_ui(t, x, m, prec);
        acb_bernoulli_poly_ui(res1, n, t, prec);

        acb_zero(res2);
        for (k = 0; k < m; k++)
        {
            acb_set_ui(t, k);
            acb_div_ui(t, t, m, prec);
            acb_add(t, t, x, prec);
            acb_bernoulli_poly_ui(t, n, t, prec);
            acb_add(res2, res2, t, prec);
        }

        if (n > 0)
        {
            arb_ui_pow_ui(acb_realref(t), m, n - 1, prec);
            acb_mul_arb(res2, res2, acb_realref(t), prec);
        }
        else
        {
            acb_div_ui(res2, res2, m, prec);
        }

        if (!acb_overlaps(res1, res2))
        {
            flint_printf("FAIL: overlap\n\n");
            flint_printf("n = %wu, m = %wu\n\n", n, m);
            flint_printf("x = "); acb_printd(x, 15); flint_printf("\n\n");
            flint_printf("res1 = "); acb_printd(res1, 15); flint_printf("\n\n");
            flint_printf("res2 = "); acb_printd(res2, 15); flint_printf("\n\n");
            abort();
        }

        acb_clear(x);
        acb_clear(t);
        acb_clear(res1);
        acb_clear(res2);
    }

    flint_randclear(state);
    flint_cleanup();
    flint_printf("PASS\n");
    return EXIT_SUCCESS;
}
void
bernoulli_rev_init(bernoulli_rev_t iter, ulong nmax)
{
    long j;
    fmpz_t t;
    arb_t x;
    arf_t u;
    int round1, round2;
    long wp;

    nmax -= (nmax % 2);
    iter->n = nmax;

    iter->alloc = 0;
    if (nmax < BERNOULLI_REV_MIN)
        return;

    iter->prec = wp = bernoulli_global_prec(nmax);

    iter->max_power = bernoulli_zeta_terms(nmax, iter->prec);
    iter->alloc = iter->max_power + 1;
    iter->powers = _fmpz_vec_init(iter->alloc);
    fmpz_init(iter->pow_error);
    arb_init(iter->prefactor);
    arb_init(iter->two_pi_squared);

    arb_init(x);
    fmpz_init(t);
    arf_init(u);

    /* precompute powers */
    for (j = 3; j <= iter->max_power; j += 2)
    {
        arb_ui_pow_ui(x, j, nmax, bernoulli_power_prec(j, nmax, wp));
        arb_inv(x, x, bernoulli_power_prec(j, nmax, wp));
        round1 = arf_get_fmpz_fixed_si(t, arb_midref(x), -wp);
        fmpz_set(iter->powers + j, t);

        /* error: the radius, plus two roundings */
        arf_set_mag(u, arb_radref(x));
        round2 = arf_get_fmpz_fixed_si(t, u, -wp);
        fmpz_add_ui(t, t, (round1 != 0) + (round2 != 0));
        if (fmpz_cmp(iter->pow_error, t) < 0)
            fmpz_set(iter->pow_error, t);
    }

    /* precompute (2pi)^2 and 2*(n!)/(2pi)^n */
    arb_fac_ui(iter->prefactor, nmax, wp);
    arb_mul_2exp_si(iter->prefactor, iter->prefactor, 1);

    arb_const_pi(x, wp);
    arb_mul_2exp_si(x, x, 1);
    arb_mul(iter->two_pi_squared, x, x, wp);

    arb_pow_ui(x, iter->two_pi_squared, nmax / 2, wp);
    arb_div(iter->prefactor, iter->prefactor, x, wp);

    fmpz_clear(t);
    arb_clear(x);
    arf_clear(u);
}