Exemple #1
0
void
arb_sin_cos_pi(arb_t s, arb_t c, const arb_t x, long prec)
{
    arb_t t;
    arb_t u;
    fmpz_t v;

    if (arf_cmpabs_2exp_si(arb_midref(x), FLINT_MAX(65536, (4*prec))) > 0)
    {
        arf_zero(arb_midref(s));
        mag_one(arb_radref(s));
        arf_zero(arb_midref(c));
        mag_one(arb_radref(c));
        return;
    }

    arb_init(t);
    arb_init(u);
    fmpz_init(v);

    arb_mul_2exp_si(t, x, 1);
    arf_get_fmpz(v, arb_midref(t), ARF_RND_NEAR);
    arb_sub_fmpz(t, t, v, prec);

    arb_const_pi(u, prec);
    arb_mul(t, t, u, prec);
    arb_mul_2exp_si(t, t, -1);

    switch (fmpz_fdiv_ui(v, 4))
    {
        case 0:
            arb_sin_cos(s, c, t, prec);
            break;
        case 1:
            arb_sin_cos(c, s, t, prec);
            arb_neg(c, c);
            break;
        case 2:
            arb_sin_cos(s, c, t, prec);
            arb_neg(s, s);
            arb_neg(c, c);
            break;
        default:
            arb_sin_cos(c, s, t, prec);
            arb_neg(s, s);
            break;
    }

    fmpz_clear(v);
    arb_clear(t);
    arb_clear(u);
}
Exemple #2
0
Fichier : sub.c Projet : isuruf/arb
int
arf_sub_special(arf_t z, const arf_t x, const arf_t y, slong prec, arf_rnd_t rnd)
{
    if (arf_is_zero(x))
    {
        if (arf_is_zero(y))
        {
            arf_zero(z);
            return 0;
        }
        else
            return arf_neg_round(z, y, prec, rnd);
    }
    else if (arf_is_zero(y))
    {
        return arf_set_round(z, x, prec, rnd);
    }
    else if (arf_is_nan(x) || arf_is_nan(y)
        || (arf_is_pos_inf(x) && arf_is_pos_inf(y))
        || (arf_is_neg_inf(x) && arf_is_neg_inf(y)))
    {
        arf_nan(z);
        return 0;
    }
    else if (arf_is_special(x))
    {
        arf_set(z, x);
        return 0;
    }
    else
    {
        arf_neg(z, y);
        return 0;
    }
}
Exemple #3
0
void
arf_ceil(arf_t z, const arf_t x)
{
    if (arf_is_special(x) || arf_is_int(x))
    {
        arf_set(z, x);
    }
    else
    {
        slong exp = ARF_EXP(x);

        /* now exp cannot be too large, as we would have
           caught this in arf_is_int() */
        if (COEFF_IS_MPZ(exp) || exp <= 0)
        {
            if (ARF_SGNBIT(x))
                arf_zero(z);
            else
                arf_one(z);
        }
        else if (exp == 1)
        {
            arf_set_si(z, ARF_SGNBIT(x) ? -1 : 2);
        }
        else
        {
            arf_set_round(z, x, exp, ARF_RND_CEIL);
        }
    }
}
Exemple #4
0
Fichier : erf.c Projet : isuruf/arb
void
acb_hypgeom_erf_asymp(acb_t res, const acb_t z, slong prec, slong prec2)
{
    acb_t a, t, u;

    acb_init(a);
    acb_init(t);
    acb_init(u);

    acb_one(a);
    acb_mul_2exp_si(a, a, -1);
    acb_mul(t, z, z, prec2);

    acb_hypgeom_u_asymp(u, a, a, t, -1, prec2);

    acb_neg(t, t);
    acb_exp(t, t, prec2);
    acb_mul(u, u, t, prec2);

    acb_const_pi(t, prec2);
    acb_sqrt(t, t, prec2);
    acb_mul(t, t, z, prec2);

    acb_div(u, u, t, prec2);

    /* branch cut term: -1 or 1 */
    if (arb_contains_zero(acb_realref(z)))
    {
        arb_zero(acb_imagref(t));
        arf_zero(arb_midref(acb_realref(t)));
        mag_one(arb_radref(acb_realref(t)));
    }
    else
    {
        acb_set_si(t, arf_sgn(arb_midref(acb_realref(z))));
    }

    acb_sub(t, t, u, prec);

    if (arb_is_zero(acb_imagref(z)))
        arb_zero(acb_imagref(t));
    else if (arb_is_zero(acb_realref(z)))
        arb_zero(acb_realref(t));

    acb_set(res, t);

    acb_clear(a);
    acb_clear(t);
    acb_clear(u);
}
Exemple #5
0
void
arb_sinc(arb_t z, const arb_t x, slong prec)
{
    mag_t c, r;
    mag_init(c);
    mag_init(r);
    mag_set_ui_2exp_si(c, 5, -1);
    arb_get_mag_lower(r, x);
    if (mag_cmp(c, r) < 0)
    {
        /* x is not near the origin */
        _arb_sinc_direct(z, x, prec);
    }
    else if (mag_cmp_2exp_si(arb_radref(x), 1) < 0)
    {
        /* determine error magnitude using the derivative bound */
        if (arb_is_exact(x))
        {
            mag_zero(c);
        }
        else
        {
            _arb_sinc_derivative_bound(r, x);
            mag_mul(c, arb_radref(x), r);
        }

        /* evaluate sinc at the midpoint of x */
        if (arf_is_zero(arb_midref(x)))
        {
            arb_one(z);
        }
        else
        {
            arb_get_mid_arb(z, x);
            _arb_sinc_direct(z, z, prec);
        }

        /* add the error */
        mag_add(arb_radref(z), arb_radref(z), c);
    }
    else
    {
        /* x has a large radius and includes points near the origin */
        arf_zero(arb_midref(z));
        mag_one(arb_radref(z));
    }

    mag_clear(c);
    mag_clear(r);
}
Exemple #6
0
void
arf_set_fmpr(arf_t y, const fmpr_t x)
{
    if (fmpr_is_special(x))
    {
        if (fmpr_is_zero(x))
            arf_zero(y);
        else if (fmpr_is_pos_inf(x))
            arf_pos_inf(y);
        else if (fmpr_is_neg_inf(x))
            arf_neg_inf(y);
        else
            arf_nan(y);
    }
    else
    {
        arf_set_fmpz(y, fmpr_manref(x));
        fmpz_add_inline(ARF_EXPREF(y), ARF_EXPREF(y), fmpr_expref(x));
    }
}
Exemple #7
0
void
arb_mul_naive(arb_t z, const arb_t x, const arb_t y, slong prec)
{
    arf_t zm_exact, zm_rounded, zr, t, u;

    arf_init(zm_exact);
    arf_init(zm_rounded);
    arf_init(zr);
    arf_init(t);
    arf_init(u);

    arf_mul(zm_exact, arb_midref(x), arb_midref(y), ARF_PREC_EXACT, ARF_RND_DOWN);
    arf_set_round(zm_rounded, zm_exact, prec, ARB_RND);

    /* rounding error */
    if (arf_equal(zm_exact, zm_rounded))
    {
        arf_zero(zr);
    }
    else
    {
        fmpz_t e;
        fmpz_init(e);

        /* more accurate, but not what we are testing
        arf_sub(zr, zm_exact, zm_rounded, MAG_BITS, ARF_RND_UP);
        arf_abs(zr, zr); */

        fmpz_sub_ui(e, ARF_EXPREF(zm_rounded), prec);
        arf_one(zr);
        arf_mul_2exp_fmpz(zr, zr, e);
        fmpz_clear(e);
    }

    /* propagated error */
    if (!arb_is_exact(x))
    {
        arf_set_mag(t, arb_radref(x));
        arf_abs(u, arb_midref(y));
        arf_addmul(zr, t, u, MAG_BITS, ARF_RND_UP);
    }

    if (!arb_is_exact(y))
    {
        arf_set_mag(t, arb_radref(y));
        arf_abs(u, arb_midref(x));
        arf_addmul(zr, t, u, MAG_BITS, ARF_RND_UP);
    }

    if (!arb_is_exact(x) && !arb_is_exact(y))
    {
        arf_set_mag(t, arb_radref(x));
        arf_set_mag(u, arb_radref(y));
        arf_addmul(zr, t, u, MAG_BITS, ARF_RND_UP);
    }

    arf_set(arb_midref(z), zm_rounded);
    arf_get_mag(arb_radref(z), zr);

    arf_clear(zm_exact);
    arf_clear(zm_rounded);
    arf_clear(zr);
    arf_clear(t);
    arf_clear(u);
}
Exemple #8
0
int arb_mat_jacobi(arb_mat_t D, arb_mat_t P, const arb_mat_t A, slong prec) {
    //
    // Given a d x d real symmetric matrix A, compute an orthogonal matrix
    // P and a diagonal D such that A = P D P^t = P D P^(-1).
    //
    // D should have already been initialized as a d x 1 matrix, and Pp
    // should have already been initialized as a d x d matrix.
    //
    // If the eigenvalues can be certified as unique, then a nonzero int is
    // returned, and the eigenvectors should have reasonable error bounds. If
    // the eigenvalues cannot be certified as unique, then some of the
    // eigenvectors will have infinite error radius.

#define B(i,j) arb_mat_entry(B, i, j)
#define D(i) arb_mat_entry(D, i, 0)
#define P(i,j) arb_mat_entry(P, i, j)
    int dim = arb_mat_nrows(A);
    if(dim == 1) {
        arb_mat_set(D, A);
        arb_mat_one(P);
        return 0;
    }
    arb_mat_t B;
    arb_mat_init(B, dim, dim);

    arf_t * B1 = (arf_t*)malloc(dim * sizeof(arf_t));
    arf_t * B2 = (arf_t*)malloc(dim * sizeof(arf_t));
    arf_t * row_max = (arf_t*)malloc((dim - 1) * sizeof(arf_t));
    int * row_max_indices = (int*)malloc((dim - 1) * sizeof(int));

    for(int k = 0; k < dim; k++) {
        arf_init(B1[k]);
        arf_init(B2[k]);
    }
    for(int k = 0; k < dim - 1; k++) {
        arf_init(row_max[k]);
    }

    arf_t x1, x2;
    arf_init(x1);
    arf_init(x2);

    arf_t Gii, Gij, Gji, Gjj;
    arf_init(Gii);
    arf_init(Gij);
    arf_init(Gji);
    arf_init(Gjj);

    arb_mat_set(B, A);
    arb_mat_one(P);

    for(int i = 0; i < dim - 1; i++) {
        for(int j = i + 1; j < dim; j++) {
            arf_abs(x1, arb_midref(B(i,j)));
            if(arf_cmp(row_max[i], x1) < 0) {
                arf_set(row_max[i], x1);
                row_max_indices[i] = j;
            }
        }
    }


    int finished = 0;

    while(!finished) {
        arf_zero(x1);
        int i = 0;
        int j = 0;
        for(int k = 0; k < dim - 1; k++) {
            if(arf_cmp(x1, row_max[k]) < 0) {
                arf_set(x1, row_max[k]);
                i = k;
            }
        }
        j = row_max_indices[i];

        slong bound = arf_abs_bound_lt_2exp_si(x1);
        if(bound < -prec * .9) {
            finished = 1;
            break;
        }
        else {
            //printf("%ld\n", arf_abs_bound_lt_2exp_si(x1));
            //arb_mat_printd(B, 10);
            //printf("\n");
        }

        arf_twobytwo_diag(Gii, Gij, arb_midref(B(i,i)), arb_midref(B(i,j)), arb_midref(B(j,j)), 2*prec);
        arf_neg(Gji, Gij);
        arf_set(Gjj, Gii);

        //printf("%d %d\n", i, j);
        //arf_printd(Gii, 100);
        //printf(" ");
        //arf_printd(Gij, 100);
        //printf("\n");
        if(arf_is_zero(Gij)) {  // If this happens, we're
            finished = 1;       // not going to do any better
            break;              // without increasing the precision.
        }

        for(int k = 0; k < dim; k++) {
            arf_mul(B1[k], Gii, arb_midref(B(i,k)), prec, ARF_RND_NEAR);
            arf_addmul(B1[k], Gji, arb_midref(B(j,k)), prec, ARF_RND_NEAR);

            arf_mul(B2[k], Gij, arb_midref(B(i,k)), prec, ARF_RND_NEAR);
            arf_addmul(B2[k], Gjj, arb_midref(B(j,k)), prec, ARF_RND_NEAR);
        }
        for(int k = 0; k < dim; k++) {
            arf_set(arb_midref(B(i,k)), B1[k]);
            arf_set(arb_midref(B(j,k)), B2[k]);
        }
        for(int k = 0; k < dim; k++) {
            arf_mul(B1[k], Gii, arb_midref(B(k,i)), prec, ARF_RND_NEAR);
            arf_addmul(B1[k], Gji, arb_midref(B(k,j)), prec, ARF_RND_NEAR);

            arf_mul(B2[k], Gij, arb_midref(B(k,i)), prec, ARF_RND_NEAR);
            arf_addmul(B2[k], Gjj, arb_midref(B(k,j)), prec, ARF_RND_NEAR);
        }
        for(int k = 0; k < dim; k++) {
            arf_set(arb_midref(B(k,i)), B1[k]);
            arf_set(arb_midref(B(k,j)), B2[k]);
        }

        for(int k = 0; k < dim; k++) {
            arf_mul(B1[k], Gii, arb_midref(P(k,i)), prec, ARF_RND_NEAR);
            arf_addmul(B1[k], Gji, arb_midref(P(k,j)), prec, ARF_RND_NEAR);

            arf_mul(B2[k], Gij, arb_midref(P(k,i)), prec, ARF_RND_NEAR);
            arf_addmul(B2[k], Gjj, arb_midref(P(k,j)), prec, ARF_RND_NEAR);
        }
        for(int k = 0; k < dim; k++) {
            arf_set(arb_midref(P(k,i)), B1[k]);
            arf_set(arb_midref(P(k,j)), B2[k]);
        }

        if(i < dim - 1)
            arf_set_ui(row_max[i], 0);
        if(j < dim - 1)
            arf_set_ui(row_max[j], 0);

        // Update the max in any row where the maximum
        // was in a column that changed.
        for(int k = 0; k < dim - 1; k++) {
            if(row_max_indices[k] == j || row_max_indices[k] == i) {
                arf_abs(row_max[k], arb_midref(B(k,k+1)));
                row_max_indices[k] = k+1;
                for(int l = k+2; l < dim; l++) {
                    arf_abs(x1, arb_midref(B(k,l)));
                    if(arf_cmp(row_max[k], x1) < 0) {
                        arf_set(row_max[k], x1);
                        row_max_indices[k] = l;
                    }
                }
            }
        }

        // Update the max in the ith row.
        for(int k = i + 1; k < dim; k++) {
            arf_abs(x1, arb_midref(B(i, k)));
            if(arf_cmp(row_max[i], x1) < 0) {
                arf_set(row_max[i], x1);
                row_max_indices[i] = k;
            }
        }

        // Update the max in the jth row.
        for(int k = j + 1; k < dim; k++) {
            arf_abs(x1, arb_midref(B(j, k)));
            if(arf_cmp(row_max[j], x1) < 0) {
                arf_set(row_max[j], x1);
                row_max_indices[j] = k;
            }
        }

        // Go through column i to see if any of
        // the new entries are larger than the
        // max of their row.
        for(int k = 0; k < i; k++) {
            if(k == dim) continue;
            arf_abs(x1, arb_midref(B(k, i)));
            if(arf_cmp(row_max[k], x1) < 0) {
                arf_set(row_max[k], x1);
                row_max_indices[k] = i;
            }
        }

        // And then column j.
        for(int k = 0; k < j; k++) {
            if(k == dim) continue;
            arf_abs(x1, arb_midref(B(k, j)));
            if(arf_cmp(row_max[k], x1) < 0) {
                arf_set(row_max[k], x1);
                row_max_indices[k] = j;
            }
        }
    }

    for(int k = 0; k < dim; k++) {
        arb_set(D(k), B(k,k));
        arb_set_exact(D(k));
    }

    // At this point we've done that diagonalization and all that remains is
    // to certify the correctness and compute error bounds.

    arb_mat_t e;

    arb_t error_norms[dim];
    for(int k = 0; k < dim; k++) arb_init(error_norms[k]);

    arb_mat_init(e, dim, 1);

    arb_t z1, z2;
    arb_init(z1);
    arb_init(z2);
    for(int j = 0; j < dim; j++) {
        arb_mat_set(B, A);
        for(int k = 0; k < dim; k++) {
            arb_sub(B(k, k), B(k, k), D(j), prec);
        }
        for(int k = 0; k < dim; k++) {
            arb_set(arb_mat_entry(e, k, 0), P(k, j));
        }
        arb_mat_L2norm(z2, e, prec);
        arb_mat_mul(e, B, e, prec);
        arb_mat_L2norm(error_norms[j], e, prec);

        arb_div(z2, error_norms[j], z2, prec); // and now z1 is an upper bound for the
                                               // error in the eigenvalue
        arb_add_error(D(j), z2);
    }

    int unique_eigenvalues = 1;
    for(int j = 0; j < dim; j++) {
        if(j == 0) {
            arb_sub(z1, D(j), D(1), prec);
        }
        else {
            arb_sub(z1, D(j), D(0), prec);
        }
        arb_get_abs_lbound_arf(x1, z1, prec);
        for(int k = 1; k < dim; k++) {
            if(k == j) continue;
            arb_sub(z1, D(j), D(k), prec);
            arb_get_abs_lbound_arf(x2, z1, prec);
            if(arf_cmp(x2, x1) < 0) {
                arf_set(x1, x2);
            }
        }
        if(arf_is_zero(x1)) {
            unique_eigenvalues = 0;
        }
        arb_div_arf(z1, error_norms[j], x1, prec);
        for(int k = 0; k < dim; k++) {
            arb_add_error(P(k, j), z1);
        }
    }

    arb_mat_clear(e);
    arb_clear(z1);
    arb_clear(z2);
    for(int k = 0; k < dim; k++) arb_clear(error_norms[k]);

    arf_clear(x1);
    arf_clear(x2);
    arb_mat_clear(B);
    for(int k = 0; k < dim; k++) {
        arf_clear(B1[k]);
        arf_clear(B2[k]);
    }
    for(int k = 0; k < dim - 1; k++) {
        arf_clear(row_max[k]);
    }
    arf_clear(Gii);
    arf_clear(Gij);
    arf_clear(Gji);
    arf_clear(Gjj);
    free(B1);
    free(B2);
    free(row_max);
    free(row_max_indices);

    if(unique_eigenvalues) return 0;
    else return 1;
#undef B
#undef D
#undef P
}
Exemple #9
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;
}
Exemple #10
0
int
arf_sum(arf_t s, arf_srcptr terms, long len, long prec, arf_rnd_t rnd)
{
    arf_ptr blocks;
    long i, j, used;
    int have_merged, res;

    /* first check if the result is inf or nan */
    {
        int have_pos_inf = 0;
        int have_neg_inf = 0;

        for (i = 0; i < len; i++)
        {
            if (arf_is_pos_inf(terms + i))
            {
                if (have_neg_inf)
                {
                    arf_nan(s);
                    return 0;
                }
                have_pos_inf = 1;
            }
            else if (arf_is_neg_inf(terms + i))
            {
                if (have_pos_inf)
                {
                    arf_nan(s);
                    return 0;
                }
                have_neg_inf = 1;
            }
            else if (arf_is_nan(terms + i))
            {
                arf_nan(s);
                return 0;
            }
        }

        if (have_pos_inf)
        {
            arf_pos_inf(s);
            return 0;
        }

        if (have_neg_inf)
        {
            arf_neg_inf(s);
            return 0;
        }
    }

    blocks = flint_malloc(sizeof(arf_struct) * len);
    for (i = 0; i < len; i++)
        arf_init(blocks + i);

    /* put all terms into blocks */
    used = 0;
    for (i = 0; i < len; i++)
    {
        if (!arf_is_zero(terms + i))
        {
            arf_set(blocks + used, terms + i);
            used++;
        }
    }

    /* merge blocks until all are well separated */
    have_merged = 1;
    while (used >= 2 && have_merged)
    {
        have_merged = 0;

        for (i = 0; i < used && !have_merged; i++)
        {
            for (j = i + 1; j < used && !have_merged; j++)
            {
                if (_arf_are_close(blocks + i, blocks + j, prec))
                {
                    arf_add(blocks + i, blocks + i, blocks + j,
                        ARF_PREC_EXACT, ARF_RND_DOWN);

                    /* remove the merged block */
                    arf_swap(blocks + j, blocks + used - 1);
                    used--;

                    /* remove the updated block if the sum is zero */
                    if (arf_is_zero(blocks + i))
                    {
                        arf_swap(blocks + i, blocks + used - 1);
                        used--;
                    }

                    have_merged = 1;
                }
            }
        }
    }

    if (used == 0)
    {
        arf_zero(s);
        res = 0;
    }
    else if (used == 1)
    {
        res = arf_set_round(s, blocks + 0, prec, rnd);
    }
    else
    {
        /* find the two largest blocks */
        for (i = 1; i < used; i++)
            if (arf_cmpabs(blocks + 0, blocks + i) < 0)
                arf_swap(blocks + 0, blocks + i);

        for (i = 2; i < used; i++)
            if (arf_cmpabs(blocks + 1, blocks + i) < 0)
                arf_swap(blocks + 1, blocks + i);

        res = _arf_add_eps(s, blocks + 0, arf_sgn(blocks + 1), prec, rnd);
    }

    for (i = 0; i < len; i++)
        arf_clear(blocks + i);
    flint_free(blocks);

    return res;
}
Exemple #11
0
int main()
{
    slong iter;
    flint_rand_t state;

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

    flint_randinit(state);

    for (iter = 0; iter < 1000000 * arb_test_multiplier(); iter++)
    {
        slong i, len, prec, bits, expbits;
        int res1, res2;
        arf_t s1, s2, s3, err;
        mag_t err_bound;
        arf_struct terms[20];
        arf_rnd_t rnd;

        len = n_randint(state, 20);
        bits = 2 + n_randint(state, 1000);
        prec = 2 + n_randint(state, 1000);
        expbits = n_randint(state, 14);

        arf_init(s1);
        arf_init(s2);
        arf_init(s3);
        arf_init(err);
        mag_init(err_bound);

        for (i = 0; i < len; i++)
        {
            arf_init(terms + i);
            arf_randtest_special(terms + i, state, bits, expbits);
        }

        switch (n_randint(state, 4))
        {
            case 0: rnd = ARF_RND_DOWN; break;
            case 1: rnd = ARF_RND_UP; break;
            case 2: rnd = ARF_RND_FLOOR; break;
            default: rnd = ARF_RND_CEIL; break;
        }

        res1 = arf_sum(s1, terms, len, prec, rnd);

        arf_zero(s2);
        for (i = 0; i < len; i++)
            arf_add(s2, s2, terms + i, ARF_PREC_EXACT, ARF_RND_DOWN);
        res2 = arf_set_round(s3, s2, prec, rnd);

        if (!arf_equal(s1, s3) || res1 != res2)
        {
            flint_printf("FAIL (%wd)\n\n", iter);
            flint_printf("prec = %wd\n\n", prec);
            for (i = 0; i < len; i++)
            {
                flint_printf("terms[%wd] = ", i); arf_print(terms + i); flint_printf("\n\n");
            }
            flint_printf("s1 = "); arf_print(s1); flint_printf("\n\n");
            flint_printf("s2 = "); arf_print(s2); flint_printf("\n\n");
            flint_printf("s3 = "); arf_print(s3); flint_printf("\n\n");
            flint_printf("res1 = %d, res2 = %d\n\n", res1, res2);
            abort();
        }

        arf_sub(err, s1, s2, ARF_PREC_EXACT, ARF_RND_DOWN);
        arf_abs(err, err);

        if (res1)
            arf_mag_set_ulp(err_bound, s1, prec);
        else
            mag_zero(err_bound);

        if (arf_cmpabs_mag(err, err_bound) > 0)
        {
            flint_printf("FAIL (error bound)!\n");
            flint_printf("prec = %wd\n\n", prec);
            for (i = 0; i < len; i++)
            {
                flint_printf("terms[%wd] = ", i); arf_print(terms + i); flint_printf("\n\n");
            }
            flint_printf("s1 = "); arf_print(s1); flint_printf("\n\n");
            flint_printf("s2 = "); arf_print(s2); flint_printf("\n\n");
            flint_printf("s3 = "); arf_print(s3); flint_printf("\n\n");
            flint_printf("error: "); arf_print(err); flint_printf("\n\n");
            flint_printf("error bound: "); mag_print(err_bound); flint_printf("\n\n");
            flint_printf("res1 = %d, res2 = %d\n\n", res1, res2);
            abort();
        }

        arf_clear(s1);
        arf_clear(s2);
        arf_clear(s3);
        arf_clear(err);
        mag_clear(err_bound);

        for (i = 0; i < len; i++)
            arf_clear(terms + i);
    }

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