Пример #1
0
int _arf_are_close(const arf_t x, const arf_t y, long prec)
{
    fmpz_t xb, yb;
    fmpz_t delta;
    int result;

    fmpz_init(xb);
    fmpz_init(yb);
    fmpz_init(delta);

    arf_bot(xb, x);
    arf_bot(yb, y);

    if (fmpz_cmp(ARF_EXPREF(x), ARF_EXPREF(y)) >= 0)
        fmpz_sub(delta, xb, ARF_EXPREF(y));
    else
        fmpz_sub(delta, yb, ARF_EXPREF(x));

    fmpz_sub_ui(delta, delta, 64);
    result = (fmpz_cmp_ui(delta, prec) < 0);

    fmpz_clear(xb);
    fmpz_clear(yb);
    fmpz_clear(delta);

    return result;
}
Пример #2
0
int main()
{
    slong iter;
    flint_rand_t state;

    flint_printf("is_int_2exp_si....");
    fflush(stdout);

    flint_randinit(state);

    for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
    {
        arf_t x, y;
        fmpz_t t;
        slong e;
        int res1, res2;

        arf_init(x);
        arf_init(y);
        fmpz_init(t);

        arf_randtest_special(x, state, 2000, 100);
        e = n_randtest(state);
        arf_mul_2exp_si(y, x, e);

        res1 = arf_is_int(x);
        res2 = arf_is_int_2exp_si(y, e);

        if (res1 != res2)
        {
            flint_printf("FAIL! (1)\n");
            flint_printf("x = "); arf_print(x); flint_printf("\n\n");
            flint_printf("y = "); arf_print(y); flint_printf("\n\n");
            flint_printf("res1 = %d, res2 = %d\n\n", res1, res2);
            abort();
        }

        if (res1)
        {
            if (n_randint(state, 2))
                arf_floor(y, x);
            else
                arf_ceil(y, x);

            if (!arf_equal(x, y) || !arf_is_finite(x))
            {
                flint_printf("FAIL! (2)\n");
                flint_printf("x = "); arf_print(x); flint_printf("\n\n");
                flint_printf("y = "); arf_print(y); flint_printf("\n\n");
                flint_printf("res1 = %d\n\n", res1);
                abort();
            }
        }

        if (arf_is_finite(x) && !arf_is_zero(x))
        {
            arf_bot(t, x);
            fmpz_neg(t, t);
            arf_mul_2exp_fmpz(x, x, t);
            res1 = arf_is_int(x);
            arf_mul_2exp_si(y, x, -1);
            res2 = arf_is_int(y);

            if (!arf_is_int(x) || arf_is_int(y))
            {
                flint_printf("FAIL! (3)\n");
                flint_printf("x = "); arf_print(x); flint_printf("\n\n");
                flint_printf("y = "); arf_print(y); flint_printf("\n\n");
                flint_printf("res1 = %d, res2 = %d\n\n", res1, res2);
                abort();
            }
        }

        arf_clear(x);
        arf_clear(y);
        fmpz_clear(t);
    }

    flint_randclear(state);
    flint_cleanup();
    flint_printf("PASS\n");
    return EXIT_SUCCESS;
}
Пример #3
0
int
arb_get_unique_fmpz(fmpz_t z, const arb_t x)
{
    if (!arb_is_finite(x))
    {
        return 0;
    }
    else if (arb_is_exact(x))
    {
        /* x = b*2^e, e >= 0 */
        if (arf_is_int(arb_midref(x)))
        {
            /* arf_get_fmpz aborts on overflow */
            arf_get_fmpz(z, arb_midref(x), ARF_RND_DOWN);
            return 1;
        }
        else
        {
            return 0;
        }
    }
    /* if the radius is >= 1, there are at least two integers */
    else if (mag_cmp_2exp_si(arb_radref(x), 0) >= 0)
    {
        return 0;
    }
    /* there are 0 or 1 integers if the radius is < 1 */
    else
    {
        fmpz_t a, b, exp;
        int res;

        /* if the midpoint is exactly an integer, it is what we want */
        if (arf_is_int(arb_midref(x)))
        {
            /* arf_get_fmpz aborts on overflow */
            arf_get_fmpz(z, arb_midref(x), ARF_RND_DOWN);
            return 1;
        }

        fmpz_init(a);
        fmpz_init(b);
        fmpz_init(exp);

        /* if the radius is tiny, it can't be an integer */
        arf_bot(a, arb_midref(x));

        if (fmpz_cmp(a, MAG_EXPREF(arb_radref(x))) > 0)
        {
            res = 0;
        }
        else
        {
            arb_get_interval_fmpz_2exp(a, b, exp, x);

            if (COEFF_IS_MPZ(*exp))
            {
                flint_printf("arb_get_unique_fmpz: input too large\n");
                abort();
            }

            if (*exp >= 0)
            {
                res = fmpz_equal(a, b);

                if (res)
                {
                    fmpz_mul_2exp(a, a, *exp);
                    fmpz_mul_2exp(b, b, *exp);
                }
            }
            else
            {
                fmpz_cdiv_q_2exp(a, a, -(*exp));
                fmpz_fdiv_q_2exp(b, b, -(*exp));
                res = fmpz_equal(a, b);
            }

            if (res)
                fmpz_set(z, a);
        }

        fmpz_clear(a);
        fmpz_clear(b);
        fmpz_clear(exp);

        return res;
    }
}