示例#1
0
文件: t-ceil.c 项目: videlec/e-antic
void test_field1(flint_rand_t state)
{
    /* tests in QQ[sqrt(5)] */
    int iter;

    fmpq_t k;
    fmpq_poly_t p;
    arb_t emb;
    renf_t nf;
    renf_elem_t a;

    fmpq_poly_init(p);
    fmpq_poly_set_coeff_si(p, 2, 1);
    fmpq_poly_set_coeff_si(p, 1, -1);
    fmpq_poly_set_coeff_si(p, 0, -1);

    arb_init(emb);
    arb_set_d(emb, 1.61803398874989);
    arb_add_error_2exp_si(emb, -20);
    renf_init(nf, p, emb, 20 + n_randint(state, 20));
    arb_clear(emb);

    renf_elem_init(a, nf);
    fmpq_init(k);

    /* (1+sqrt(5))/2 vs Fibonacci */
    fmpq_poly_zero(p);
    fmpq_poly_set_coeff_si(p, 1, -1);
    for (iter = 1; iter < 50; iter++)
    {
        fprintf(stderr, "start iter = %d\n", iter);
        fflush(stderr);
        fmpz_fib_ui(fmpq_numref(k), iter+1);
        fmpz_fib_ui(fmpq_denref(k), iter);
        fmpq_poly_set_coeff_fmpq(p, 0, k);
        renf_elem_set_fmpq_poly(a, p, nf);
        check_ceil(a, nf, 1 - iter % 2, "sqrt(5)");
        fprintf(stderr, "end\n");
        fflush(stderr);
    }

    renf_elem_clear(a, nf);
    renf_clear(nf);
    fmpq_clear(k);
    fmpq_poly_clear(p);
}
示例#2
0
void arb_from_interval(arb_t x, const fmpz_t c, const slong k, const slong prec)
{
    /* we build the ball that gives exactly (c 2^k, (c+1) 2^k) */
    /*  center: (2c+1) 2^(k-1) */
    /*  radius: 2^(k-1)        */
    if (prec <= 0 || prec < fmpz_bits(c) + 2)
    {
        fprintf(stderr, "not enough precision");
        abort();
    }

    arb_set_fmpz(x, c);
    arb_mul_2exp_si(x, x, 1);
    arb_add_si(x, x, 1, prec);
    arb_mul_2exp_si(x, x, k-1);
    arb_add_error_2exp_si(x, k-1);
}
示例#3
0
int main(int argc, char *argv[])
{
    acb_t s, t, a, b;
    mag_t tol;
    slong prec, goal;
    slong N;
    ulong k;
    int integral, ifrom, ito;
    int i, twice, havegoal, havetol;
    acb_calc_integrate_opt_t options;

    ifrom = ito = -1;

    for (i = 1; i < argc; i++)
    {
        if (!strcmp(argv[i], "-i"))
        {
            if (!strcmp(argv[i+1], "all"))
            {
                ifrom = 0;
                ito = NUM_INTEGRALS - 1;
            }
            else
            {
                ifrom = ito = atol(argv[i+1]);
                if (ito < 0 || ito >= NUM_INTEGRALS)
                    flint_abort();
            }
        }
    }

    if (ifrom == -1)
    {
        flint_printf("Compute integrals using acb_calc_integrate.\n");
        flint_printf("Usage: integrals -i n [-prec p] [-tol eps] [-twice] [...]\n\n");
        flint_printf("-i n       - compute integral n (0 <= n <= %d), or \"-i all\"\n", NUM_INTEGRALS - 1);
        flint_printf("-prec p    - precision in bits (default p = 64)\n");
        flint_printf("-goal p    - approximate relative accuracy goal (default p)\n");
        flint_printf("-tol eps   - approximate absolute error goal (default 2^-p)\n");
        flint_printf("-twice     - run twice (to see overhead of computing nodes)\n");
        flint_printf("-heap      - use heap for subinterval queue\n");
        flint_printf("-verbose   - show information\n");
        flint_printf("-verbose2  - show more information\n");
        flint_printf("-deg n     - use quadrature degree up to n\n");
        flint_printf("-eval n    - limit number of function evaluations to n\n");
        flint_printf("-depth n   - limit subinterval queue size to n\n\n");
        flint_printf("Implemented integrals:\n");
        for (integral = 0; integral < NUM_INTEGRALS; integral++)
            flint_printf("I%d = %s\n", integral, descr[integral]);
        flint_printf("\n");
        return 1;
    }

    acb_calc_integrate_opt_init(options);

    prec = 64;
    twice = 0;
    goal = 0;
    havetol = havegoal = 0;

    acb_init(a);
    acb_init(b);
    acb_init(s);
    acb_init(t);
    mag_init(tol);

    for (i = 1; i < argc; i++)
    {
        if (!strcmp(argv[i], "-prec"))
        {
            prec = atol(argv[i+1]);
        }
        else if (!strcmp(argv[i], "-twice"))
        {
            twice = 1;
        }
        else if (!strcmp(argv[i], "-goal"))
        {
            goal = atol(argv[i+1]);
            if (goal < 0)
            {
                flint_printf("expected goal >= 0\n");
                return 1;
            }
            havegoal = 1;
        }
        else if (!strcmp(argv[i], "-tol"))
        {
            arb_t x;
            arb_init(x);
            arb_set_str(x, argv[i+1], 10);
            arb_get_mag(tol, x);
            arb_clear(x);
            havetol = 1;
        }
        else if (!strcmp(argv[i], "-deg"))
        {
            options->deg_limit = atol(argv[i+1]);
        }
        else if (!strcmp(argv[i], "-eval"))
        {
            options->eval_limit = atol(argv[i+1]);
        }
        else if (!strcmp(argv[i], "-depth"))
        {
            options->depth_limit = atol(argv[i+1]);
        }
        else if (!strcmp(argv[i], "-verbose"))
        {
            options->verbose = 1;
        }
        else if (!strcmp(argv[i], "-verbose2"))
        {
            options->verbose = 2;
        }
        else if (!strcmp(argv[i], "-heap"))
        {
            options->use_heap = 1;
        }
    }

    if (!havegoal)
        goal = prec;

    if (!havetol)
        mag_set_ui_2exp_si(tol, 1, -prec);

    for (integral = ifrom; integral <= ito; integral++)
    {
        flint_printf("I%d = %s ...\n", integral, descr[integral]);

        for (i = 0; i < 1 + twice; i++)
        {
            TIMEIT_ONCE_START
            switch (integral)
            {
            case 0:
                acb_set_d(a, 0);
                acb_set_d(b, 100);
                acb_calc_integrate(s, f_sin, NULL, a, b, goal, tol, options, prec);
                break;

            case 1:
                acb_set_d(a, 0);
                acb_set_d(b, 1);
                acb_calc_integrate(s, f_atanderiv, NULL, a, b, goal, tol, options, prec);
                acb_mul_2exp_si(s, s, 2);
                break;

            case 2:
                acb_set_d(a, 0);
                acb_one(b);
                acb_mul_2exp_si(b, b, goal);
                acb_calc_integrate(s, f_atanderiv, NULL, a, b, goal, tol, options, prec);
                arb_add_error_2exp_si(acb_realref(s), -goal);
                acb_mul_2exp_si(s, s, 1);
                break;

            case 3:
                acb_set_d(a, 0);
                acb_set_d(b, 1);
                acb_calc_integrate(s, f_circle, NULL, a, b, goal, tol, options, prec);
                acb_mul_2exp_si(s, s, 2);
                break;

            case 4:
                acb_set_d(a, 0);
                acb_set_d(b, 8);
                acb_calc_integrate(s, f_rump, NULL, a, b, goal, tol, options, prec);
                break;

            case 5:
                acb_set_d(a, 1);
                acb_set_d(b, 101);
                acb_calc_integrate(s, f_floor, NULL, a, b, goal, tol, options, prec);
                break;

            case 6:
                acb_set_d(a, 0);
                acb_set_d(b, 1);
                acb_calc_integrate(s, f_helfgott, NULL, a, b, goal, tol, options, prec);
                break;

            case 7:
                acb_zero(s);

                acb_set_d_d(a, -1.0, -1.0);
                acb_set_d_d(b, 2.0, -1.0);
                acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, 2.0, -1.0);
                acb_set_d_d(b, 2.0, 1.0);
                acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, 2.0, 1.0);
                acb_set_d_d(b, -1.0, 1.0);
                acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, -1.0, 1.0);
                acb_set_d_d(b, -1.0, -1.0);
                acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_const_pi(t, prec);
                acb_div(s, s, t, prec);
                acb_mul_2exp_si(s, s, -1);
                acb_div_onei(s, s);
                break;

            case 8:
                acb_set_d(a, 0);
                acb_set_d(b, 1);
                acb_calc_integrate(s, f_essing, NULL, a, b, goal, tol, options, prec);
                break;

            case 9:
                acb_set_d(a, 0);
                acb_set_d(b, 1);
                acb_calc_integrate(s, f_essing2, NULL, a, b, goal, tol, options, prec);
                break;

            case 10:
                acb_set_d(a, 0);
                acb_set_d(b, 10000);
                acb_calc_integrate(s, f_factorial1000, NULL, a, b, goal, tol, options, prec);
                break;

            case 11:
                acb_set_d_d(a, 1.0, 0.0);
                acb_set_d_d(b, 1.0, 1000.0);
                acb_calc_integrate(s, f_gamma, NULL, a, b, goal, tol, options, prec);
                break;

            case 12:
                acb_set_d(a, -10.0);
                acb_set_d(b, 10.0);
                acb_calc_integrate(s, f_sin_plus_small, NULL, a, b, goal, tol, options, prec);
                break;

            case 13:
                acb_set_d(a, -1020.0);
                acb_set_d(b, -1010.0);
                acb_calc_integrate(s, f_exp, NULL, a, b, goal, tol, options, prec);
                break;

            case 14:
                acb_set_d(a, 0);
                acb_set_d(b, ceil(sqrt(goal * 0.693147181) + 1.0));
                acb_calc_integrate(s, f_gaussian, NULL, a, b, goal, tol, options, prec);
                acb_mul(b, b, b, prec);
                acb_neg(b, b);
                acb_exp(b, b, prec);
                arb_add_error(acb_realref(s), acb_realref(b));
                break;

            case 15:
                acb_set_d(a, 0.0);
                acb_set_d(b, 1.0);
                acb_calc_integrate(s, f_spike, NULL, a, b, goal, tol, options, prec);
                break;

            case 16:
                acb_set_d(a, 0.0);
                acb_set_d(b, 8.0);
                acb_calc_integrate(s, f_monster, NULL, a, b, goal, tol, options, prec);
                break;

            case 17:
                acb_set_d(a, 0);
                acb_set_d(b, ceil(goal * 0.693147181 + 1.0));
                acb_calc_integrate(s, f_sech, NULL, a, b, goal, tol, options, prec);
                acb_neg(b, b);
                acb_exp(b, b, prec);
                acb_mul_2exp_si(b, b, 1);
                arb_add_error(acb_realref(s), acb_realref(b));
                break;

            case 18:
                acb_set_d(a, 0);
                acb_set_d(b, ceil(goal * 0.693147181 / 3.0 + 2.0));
                acb_calc_integrate(s, f_sech3, NULL, a, b, goal, tol, options, prec);
                acb_neg(b, b);
                acb_mul_ui(b, b, 3, prec);
                acb_exp(b, b, prec);
                acb_mul_2exp_si(b, b, 3);
                acb_div_ui(b, b, 3, prec);
                arb_add_error(acb_realref(s), acb_realref(b));
                break;

            case 19:
                if (goal < 0)
                    abort();
                /* error bound 2^-N (1+N) when truncated at 2^-N */
                N = goal + FLINT_BIT_COUNT(goal);
                acb_one(a);
                acb_mul_2exp_si(a, a, -N);
                acb_one(b);
                acb_calc_integrate(s, f_log_div1p, NULL, a, b, goal, tol, options, prec);
                acb_set_ui(b, N + 1);
                acb_mul_2exp_si(b, b, -N);
                arb_add_error(acb_realref(s), acb_realref(b));
                break;

           case 20:
                if (goal < 0)
                    abort();
                /* error bound (N+1) exp(-N) when truncated at N */
                N = goal + FLINT_BIT_COUNT(goal);
                acb_zero(a);
                acb_set_ui(b, N);
                acb_calc_integrate(s, f_log_div1p_transformed, NULL, a, b, goal, tol, options, prec);
                acb_neg(b, b);
                acb_exp(b, b, prec);
                acb_mul_ui(b, b, N + 1, prec);
                arb_add_error(acb_realref(s), acb_realref(b));
                break;

            case 21:

                acb_zero(s);

                N = 10;

                acb_set_d_d(a, 0.5, -0.5);
                acb_set_d_d(b, 0.5, 0.5);
                acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, 0.5, 0.5);
                acb_set_d_d(b, -0.5, 0.5);
                acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, -0.5, 0.5);
                acb_set_d_d(b, -0.5, -0.5);
                acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, -0.5, -0.5);
                acb_set_d_d(b, 0.5, -0.5);
                acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_const_pi(t, prec);
                acb_div(s, s, t, prec);
                acb_mul_2exp_si(s, s, -1);
                acb_div_onei(s, s);
                break;

            case 22:

                acb_zero(s);

                N = 1000;

                acb_set_d_d(a, 100.0, 0.0);
                acb_set_d_d(b, 100.0, N);
                acb_calc_integrate(t, f_zeta_frac, NULL, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_set_d_d(a, 100, N);
                acb_set_d_d(b, 0.5, N);
                acb_calc_integrate(t, f_zeta_frac, NULL, a, b, goal, tol, options, prec);
                acb_add(s, s, t, prec);

                acb_div_onei(s, s);
                arb_zero(acb_imagref(s));

                acb_set_ui(t, N);
                acb_dirichlet_hardy_theta(t, t, NULL, NULL, 1, prec);
                acb_add(s, s, t, prec);

                acb_const_pi(t, prec);
                acb_div(s, s, t, prec);
                acb_add_ui(s, s, 1, prec);
                break;

            case 23:
                acb_set_d(a, 0.0);
                acb_set_d(b, 1000.0);
                acb_calc_integrate(s, f_lambertw, NULL, a, b, goal, tol, options, prec);
                break;

            case 24:
                acb_set_d(a, 0.0);
                acb_const_pi(b, prec);
                acb_calc_integrate(s, f_max_sin_cos, NULL, a, b, goal, tol, options, prec);
                break;

            case 25:
                acb_set_si(a, -1);
                acb_set_si(b, 1);
                acb_calc_integrate(s, f_erf_bent, NULL, a, b, goal, tol, options, prec);
                break;

            case 26:
                acb_set_si(a, -10);
                acb_set_si(b, 10);
                acb_calc_integrate(s, f_airy_ai, NULL, a, b, goal, tol, options, prec);
                break;

            case 27:
                acb_set_si(a, 0);
                acb_set_si(b, 10);
                acb_calc_integrate(s, f_horror, NULL, a, b, goal, tol, options, prec);
                break;

            case 28:
                acb_set_d_d(a, -1, -1);
                acb_set_d_d(b, -1, 1);
                acb_calc_integrate(s, f_sqrt, NULL, a, b, goal, tol, options, prec);
                break;

            case 29:
                acb_set_d(a, 0);
                acb_set_d(b, ceil(sqrt(goal * 0.693147181) + 1.0));
                acb_calc_integrate(s, f_gaussian_twist, NULL, a, b, goal, tol, options, prec);
                acb_mul(b, b, b, prec);
                acb_neg(b, b);
                acb_exp(b, b, prec);
                arb_add_error(acb_realref(s), acb_realref(b));
                arb_add_error(acb_imagref(s), acb_realref(b));
                break;

            case 30:
                acb_set_d(a, 0);
                acb_set_d(b, ceil(goal * 0.693147181 + 1.0));
                acb_calc_integrate(s, f_exp_airy, NULL, a, b, goal, tol, options, prec);
                acb_neg(b, b);
                acb_exp(b, b, prec);
                acb_mul_2exp_si(b, b, 1);
                arb_add_error(acb_realref(s), acb_realref(b));
                break;

            case 31:
                acb_zero(a);
                acb_const_pi(b, prec);
                acb_calc_integrate(s, f_sin_cos_frac, NULL, a, b, goal, tol, options, prec);
                break;

            case 32:
                acb_zero(a);
                acb_set_ui(b, 3);
                acb_calc_integrate(s, f_sin_near_essing, NULL, a, b, goal, tol, options, prec);
                break;

            case 33:
                acb_zero(a);
                acb_zero(b);
                k = 3;
                scaled_bessel_select_N(acb_realref(b), k, prec);
                acb_calc_integrate(s, f_scaled_bessel, &k, a, b, goal, tol, options, prec);
                scaled_bessel_tail_bound(acb_realref(a), k, acb_realref(b), prec);
                arb_add_error(acb_realref(s), acb_realref(a));
                break;

            case 34:
                acb_zero(a);
                acb_zero(b);
                k = 15;
                scaled_bessel_select_N(acb_realref(b), k, prec);
                acb_calc_integrate(s, f_scaled_bessel, &k, a, b, goal, tol, options, prec);
                scaled_bessel_tail_bound(acb_realref(a), k, acb_realref(b), prec);
                arb_add_error(acb_realref(s), acb_realref(a));
                break;

            case 35:
                acb_set_d_d(a, -1, -1);
                acb_set_d_d(b, -1, 1);
                acb_calc_integrate(s, f_rsqrt, NULL, a, b, goal, tol, options, prec);
                break;

            default:
                abort();
            }

            TIMEIT_ONCE_STOP
        }
        flint_printf("I%d = ", integral);
        acb_printn(s, 3.333 * prec, 0);
        flint_printf("\n\n");
    }

    acb_clear(a);
    acb_clear(b);
    acb_clear(s);
    acb_clear(t);
    mag_clear(tol);

    flint_cleanup();
    return 0;
}
示例#4
0
int main()
{
    long iter;
    flint_rand_t state;

    printf("add_error....");
    fflush(stdout);

    flint_randinit(state);

    for (iter = 0; iter < 10000; iter++)
    {
        arb_t a, b, c;
        arf_t m, r;

        arb_init(a);
        arb_init(b);
        arb_init(c);
        arf_init(m);
        arf_init(r);

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(c, state, 1 + n_randint(state, 2000), 10);
        arf_randtest_special(m, state, 1 + n_randint(state, 2000), 10);
        arf_randtest_special(r, state, 1 + n_randint(state, 2000), 10);

        /* c = a plus error bounds */
        arb_set(c, a);
        arf_set(arb_midref(b), m);
        arf_get_mag(arb_radref(b), r);
        arb_add_error(c, b);

        /* b = a + random point */
        arb_set(b, a);

        if (n_randint(state, 2))
            arf_add(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN);
        else
            arf_sub(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN);

        if (n_randint(state, 2))
            arf_add(arb_midref(b), arb_midref(b), r, ARF_PREC_EXACT, ARF_RND_DOWN);
        else
            arf_sub(arb_midref(b), arb_midref(b), r, ARF_PREC_EXACT, ARF_RND_DOWN);

        /* should this be done differently? */
        if (arf_is_nan(arb_midref(b)))
            arf_zero(arb_midref(b));

        if (!arb_contains(c, b))
        {
            printf("FAIL (arb_add_error)\n\n");
            printf("a = "); arb_printn(a, 50, 0); printf("\n\n");
            printf("b = "); arb_printn(b, 50, 0); printf("\n\n");
            printf("c = "); arb_printn(c, 50, 0); printf("\n\n");
            abort();
        }

        arb_clear(a);
        arb_clear(b);
        arb_clear(c);
        arf_clear(m);
        arf_clear(r);
    }

    for (iter = 0; iter < 10000; iter++)
    {
        arb_t a, b, c;
        arf_t m;

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

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(c, state, 1 + n_randint(state, 2000), 10);
        arf_randtest_special(m, state, 1 + n_randint(state, 2000), 10);

        /* c = a plus error bounds */
        arb_set(c, a);
        arb_add_error_arf(c, m);

        /* b = a + random point */
        arb_set(b, a);

        if (n_randint(state, 2))
            arf_add(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN);
        else
            arf_sub(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN);

        /* should this be done differently? */
        if (arf_is_nan(arb_midref(b)))
            arf_zero(arb_midref(b));

        if (!arb_contains(c, b))
        {
            printf("FAIL (arb_add_error_arf)\n\n");
            printf("a = "); arb_printn(a, 50, 0); printf("\n\n");
            printf("b = "); arb_printn(b, 50, 0); printf("\n\n");
            printf("c = "); arb_printn(c, 50, 0); printf("\n\n");
            abort();
        }

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

    for (iter = 0; iter < 10000; iter++)
    {
        arb_t a, b, c;
        arf_t t;
        mag_t r;

        arb_init(a);
        arb_init(b);
        arb_init(c);
        mag_init(r);
        arf_init(t);

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10);
        mag_randtest(r, state, 10);

        /* c = a plus error bounds */
        arb_set(c, a);
        arb_add_error_mag(c, r);

        /* b = a + random point */
        arb_set(b, a);
        arf_set_mag(t, r);
        if (n_randint(state, 2))
            arf_add(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN);
        else
            arf_sub(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN);

        /* should this be done differently? */
        if (arf_is_nan(arb_midref(b)))
            arf_zero(arb_midref(b));

        if (!arb_contains(c, b))
        {
            printf("FAIL (arb_add_error_mag)\n\n");
            printf("a = "); arb_printn(a, 50, 0); printf("\n\n");
            printf("b = "); arb_printn(b, 50, 0); printf("\n\n");
            printf("c = "); arb_printn(c, 50, 0); printf("\n\n");
            abort();
        }

        arb_clear(a);
        arb_clear(b);
        arb_clear(c);
        mag_clear(r);
        arf_clear(t);
    }

    for (iter = 0; iter < 10000; iter++)
    {
        arb_t a, b, c;
        arf_t t;
        long e;

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

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10);
        e = n_randint(state, 10) - 10;

        /* c = a plus error bounds */
        arb_set(c, a);
        arb_add_error_2exp_si(c, e);

        /* b = a + random point */
        arb_set(b, a);
        arf_one(t);
        arf_mul_2exp_si(t, t, e);
        if (n_randint(state, 2))
            arf_add(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN);
        else
            arf_sub(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN);

        /* should this be done differently? */
        if (arf_is_nan(arb_midref(b)))
            arf_zero(arb_midref(b));

        if (!arb_contains(c, b))
        {
            printf("FAIL (arb_add_error_2exp_si)\n\n");
            printf("a = "); arb_printn(a, 50, 0); printf("\n\n");
            printf("b = "); arb_printn(b, 50, 0); printf("\n\n");
            printf("c = "); arb_printn(c, 50, 0); printf("\n\n");
            abort();
        }

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

    for (iter = 0; iter < 10000; iter++)
    {
        arb_t a, b, c;
        arf_t t;
        fmpz_t e;

        arb_init(a);
        arb_init(b);
        arb_init(c);
        arf_init(t);
        fmpz_init(e);

        arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10);
        arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10);
        fmpz_randtest(e, state, 10);

        /* c = a plus error bounds */
        arb_set(c, a);
        arb_add_error_2exp_fmpz(c, e);

        /* b = a + random point */
        arb_set(b, a);
        arf_one(t);
        arf_mul_2exp_fmpz(t, t, e);
        if (n_randint(state, 2))
            arf_add(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN);
        else
            arf_sub(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN);

        /* should this be done differently? */
        if (arf_is_nan(arb_midref(b)))
            arf_zero(arb_midref(b));

        if (!arb_contains(c, b))
        {
            printf("FAIL (arb_add_error_2exp_fmpz)\n\n");
            printf("a = "); arb_printn(a, 50, 0); printf("\n\n");
            printf("b = "); arb_printn(b, 50, 0); printf("\n\n");
            printf("c = "); arb_printn(c, 50, 0); printf("\n\n");
            abort();
        }

        arb_clear(a);
        arb_clear(b);
        arb_clear(c);
        arf_clear(t);
        fmpz_clear(e);
    }

    flint_randclear(state);
    flint_cleanup();
    printf("PASS\n");
    return EXIT_SUCCESS;
}
示例#5
0
文件: exp_arf_bb.c 项目: isuruf/arb
void
arb_exp_arf_bb(arb_t z, const arf_t x, slong prec, int minus_one)
{
    slong k, iter, bits, r, mag, q, wp, N;
    slong argred_bits, start_bits;
    mp_bitcnt_t Qexp[1];
    int inexact;
    fmpz_t t, u, T, Q;
    arb_t w;

    if (arf_is_zero(x))
    {
        if (minus_one)
            arb_zero(z);
        else
            arb_one(z);
        return;
    }

    if (arf_is_special(x))
    {
        abort();
    }

    mag = arf_abs_bound_lt_2exp_si(x);

    /* We assume that this function only gets called with something
       reasonable as input (huge/tiny input will be handled by
       the main exp wrapper). */
    if (mag > 200 || mag < -2 * prec - 100)
    {
        flint_printf("arb_exp_arf_bb: unexpectedly large/small input\n");
        abort();
    }

    if (prec < 100000000)
    {
        argred_bits = 16;
        start_bits = 32;
    }
    else
    {
        argred_bits = 32;
        start_bits = 64;
    }

    /* Argument reduction: exp(x) -> exp(x/2^q). This improves efficiency
       of the first iteration in the bit-burst algorithm. */
    q = FLINT_MAX(0, mag + argred_bits);

    /* Determine working precision. */
    wp = prec + 10 + 2 * q + 2 * FLINT_BIT_COUNT(prec);
    if (minus_one && mag < 0)
        wp += (-mag);

    fmpz_init(t);
    fmpz_init(u);
    fmpz_init(Q);
    fmpz_init(T);
    arb_init(w);

    /* Convert x/2^q to a fixed-point number. */
    inexact = arf_get_fmpz_fixed_si(t, x, -wp + q);

    /* Aliasing of z and x is safe now that only use t. */
    /* Start with z = 1. */
    arb_one(z);

    /* Bit-burst loop. */
    for (iter = 0, bits = start_bits; !fmpz_is_zero(t);
        iter++, bits *= 2)
    {
        /* Extract bits. */
        r = FLINT_MIN(bits, wp);
        fmpz_tdiv_q_2exp(u, t, wp - r);

        /* Binary splitting (+1 fixed-point ulp truncation error). */
        mag = fmpz_bits(u) - r;
        N = bs_num_terms(mag, wp);

       _arb_exp_sum_bs_powtab(T, Q, Qexp, u, r, N);

        /* T = T / Q  (+1 fixed-point ulp error). */
        if (*Qexp >= wp)
        {
            fmpz_tdiv_q_2exp(T, T, *Qexp - wp);
            fmpz_tdiv_q(T, T, Q);
        }
        else
        {
            fmpz_mul_2exp(T, T, wp - *Qexp);
            fmpz_tdiv_q(T, T, Q);
        }

        /* T = 1 + T */
        fmpz_one(Q);
        fmpz_mul_2exp(Q, Q, wp);
        fmpz_add(T, T, Q);

        /* Now T = exp(u) with at most 2 fixed-point ulp error. */
        /* Set z = z * T. */
        arf_set_fmpz(arb_midref(w), T);
        arf_mul_2exp_si(arb_midref(w), arb_midref(w), -wp);
        mag_set_ui_2exp_si(arb_radref(w), 2, -wp);
        arb_mul(z, z, w, wp);

        /* Remove used bits. */
        fmpz_mul_2exp(u, u, wp - r);
        fmpz_sub(t, t, u);
    }

    /* We have exp(x + eps) - exp(x) < 2*eps (by assumption that the argument
       reduction is large enough). */
    if (inexact)
        arb_add_error_2exp_si(z, -wp + 1);

    fmpz_clear(t);
    fmpz_clear(u);
    fmpz_clear(Q);
    fmpz_clear(T);
    arb_clear(w);

    /* exp(x) = exp(x/2^q)^(2^q) */
    for (k = 0; k < q; k++)
        arb_mul(z, z, z, wp);

    if (minus_one)
        arb_sub_ui(z, z, 1, wp);

    arb_set_round(z, z, prec);
}