int main()
{
slong iter;
flint_rand_t state;
flint_printf("backlund_s_bound....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 500 * arb_test_multiplier(); iter++)
{
arb_t a, b;
mag_t u, v;
slong aprec, bprec;
slong abits, bbits;
aprec = 2 + n_randint(state, 1000);
bprec = 2 + n_randint(state, 1000);
abits = 2 + n_randint(state, 100);
bbits = 2 + n_randint(state, 100);
arb_init(a);
arb_init(b);
mag_init(u);
mag_init(v);
arb_randtest(a, state, aprec, abits);
arb_randtest(b, state, bprec, bbits);
if (arb_is_nonnegative(a) && arb_is_nonnegative(b))
{
acb_dirichlet_backlund_s_bound(u, a);
acb_dirichlet_backlund_s_bound(v, b);
if ((arb_lt(a, b) && mag_cmp(u, v) > 0) ||
(arb_gt(a, b) && mag_cmp(u, v) < 0))
{
flint_printf("FAIL: increasing on t >= 0\n\n");
flint_printf("a = "); arb_print(a); flint_printf("\n\n");
flint_printf("b = "); arb_print(b); flint_printf("\n\n");
flint_printf("u = "); mag_print(u); flint_printf("\n\n");
flint_printf("v = "); mag_print(v); flint_printf("\n\n");
flint_abort();
}
}
arb_clear(a);
arb_clear(b);
mag_clear(u);
mag_clear(v);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
void
mag_exp_tail(mag_t z, const mag_t x, ulong N)
{
if (N == 0 || mag_is_inf(x))
{
mag_exp(z, x);
}
else if (mag_is_zero(x))
{
mag_zero(z);
}
else
{
mag_t t;
mag_init(t);
mag_set_ui_2exp_si(t, N, -1);
/* bound by geometric series when N >= 2*x <=> N/2 >= x */
if (mag_cmp(t, x) >= 0)
{
/* 2 c^N / N! */
mag_pow_ui(t, x, N);
mag_rfac_ui(z, N);
mag_mul(z, z, t);
mag_mul_2exp_si(z, z, 1);
}
else
{
mag_exp(z, x);
}
mag_clear(t);
}
}
void
acb_hypgeom_erf_propagated_error(mag_t re, mag_t im, const acb_t z)
{
mag_t x, y;
mag_init(x);
mag_init(y);
/* |exp(-(x+y)^2)| = exp(y^2-x^2) */
arb_get_mag(y, acb_imagref(z));
mag_mul(y, y, y);
arb_get_mag_lower(x, acb_realref(z));
mag_mul_lower(x, x, x);
if (mag_cmp(y, x) >= 0)
{
mag_sub(re, y, x);
mag_exp(re, re);
}
else
{
mag_sub_lower(re, x, y);
mag_expinv(re, re);
}
/* Radius. */
mag_hypot(x, arb_radref(acb_realref(z)), arb_radref(acb_imagref(z)));
mag_mul(re, re, x);
/* 2/sqrt(pi) < 289/256 */
mag_mul_ui(re, re, 289);
mag_mul_2exp_si(re, re, -8);
if (arb_is_zero(acb_imagref(z)))
{
/* todo: could bound magnitude even for complex numbers */
mag_set_ui(y, 2);
mag_min(re, re, y);
mag_zero(im);
}
else if (arb_is_zero(acb_realref(z)))
{
mag_swap(im, re);
mag_zero(re);
}
else
{
mag_set(im, re);
}
mag_clear(x);
mag_clear(y);
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("cmp....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 100000 * arb_test_multiplier(); iter++)
{
fmpr_t x, y;
mag_t xb, yb;
int c1, c2;
fmpr_init(x);
fmpr_init(y);
mag_init(xb);
mag_init(yb);
mag_randtest_special(xb, state, 100);
mag_randtest_special(yb, state, 100);
mag_get_fmpr(x, xb);
mag_get_fmpr(y, yb);
c1 = fmpr_cmp(x, y);
c2 = mag_cmp(xb, yb);
if (c1 != c2)
{
flint_printf("FAIL\n\n");
flint_printf("x = "); fmpr_print(x); flint_printf("\n\n");
flint_printf("y = "); fmpr_print(y); flint_printf("\n\n");
flint_printf("xb = "); mag_print(xb); flint_printf("\n\n");
flint_printf("yb = "); mag_print(yb); flint_printf("\n\n");
abort();
}
fmpr_clear(x);
fmpr_clear(y);
mag_clear(xb);
mag_clear(yb);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
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);
}
int arb_calc_newton_step(arb_t xnew, arb_calc_func_t func,
void * param, const arb_t x, const arb_t conv_region,
const arf_t conv_factor, slong prec)
{
mag_t err, v;
arb_t t;
arb_struct u[2];
int result;
mag_init(err);
mag_init(v);
arb_init(t);
arb_init(u + 0);
arb_init(u + 1);
mag_mul(err, arb_radref(x), arb_radref(x));
arf_get_mag(v, conv_factor);
mag_mul(err, err, v);
arf_set(arb_midref(t), arb_midref(x));
mag_zero(arb_radref(t));
func(u, t, param, 2, prec);
arb_div(u, u, u + 1, prec);
arb_sub(u, t, u, prec);
mag_add(arb_radref(u), arb_radref(u), err);
if (arb_contains(conv_region, u) &&
(mag_cmp(arb_radref(u), arb_radref(x)) < 0))
{
arb_swap(xnew, u);
result = ARB_CALC_SUCCESS;
}
else
{
arb_set(xnew, x);
result = ARB_CALC_NO_CONVERGENCE;
}
arb_clear(t);
arb_clear(u);
arb_clear(u + 1);
mag_clear(err);
mag_clear(v);
return result;
}
int
_arb_poly_newton_step(arb_t xnew, arb_srcptr poly, long len,
const arb_t x,
const arb_t convergence_interval,
const arf_t convergence_factor, long prec)
{
arf_t err;
arb_t t, u, v;
int result;
arf_init(err);
arb_init(t);
arb_init(u);
arb_init(v);
arf_set_mag(err, arb_radref(x));
arf_mul(err, err, err, MAG_BITS, ARF_RND_UP);
arf_mul(err, err, convergence_factor, MAG_BITS, ARF_RND_UP);
arf_set(arb_midref(t), arb_midref(x));
mag_zero(arb_radref(t));
_arb_poly_evaluate2(u, v, poly, len, t, prec);
arb_div(u, u, v, prec);
arb_sub(u, t, u, prec);
arb_add_error_arf(u, err);
if (arb_contains(convergence_interval, u) &&
(mag_cmp(arb_radref(u), arb_radref(x)) < 0))
{
arb_swap(xnew, u);
result = 1;
}
else
{
arb_set(xnew, x);
result = 0;
}
arb_clear(t);
arb_clear(u);
arb_clear(v);
arf_clear(err);
return result;
}
void
do_plus(longint_t *var1, longint_t *var2) {
longint_t temp;
if (var1->nega == var2->nega) {
/* same signs, can just add */
simple_plus(var1, var2);
} else {
/* different signs, need to get them right way round */
temp = *var2;
if (mag_cmp(var1, var2)>=0) {
/* can process in this order */
simple_suba(var1, &temp);
} else {
/* need to reverse the order */
simple_suba(&temp, var1);
*var1 = temp;
}
}
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("rel_accuracy_bits....");
fflush(stdout);
flint_randinit(state);
/* test aliasing of c and a */
for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
{
arb_t x;
acb_t z;
slong a1, a2;
arb_init(x);
acb_init(z);
arb_randtest_special(x, state, 1 + n_randint(state, 200), 1 + n_randint(state, 200));
acb_set_arb(z, x);
a1 = arb_rel_accuracy_bits(x);
a2 = acb_rel_accuracy_bits(z);
if (a1 != a2)
{
flint_printf("FAIL: acb != arb\n\n");
flint_printf("x = "); arb_print(x); flint_printf("\n\n");
flint_printf("z = "); acb_print(z); flint_printf("\n\n");
flint_printf("a1 = %wd, a2 = %wd\n\n", a1, a2);
abort();
}
acb_randtest_special(z, state, 1 + n_randint(state, 200), 1 + n_randint(state, 200));
a1 = acb_rel_accuracy_bits(z);
if (n_randint(state, 2))
arf_swap(arb_midref(acb_realref(z)), arb_midref(acb_imagref(z)));
if (n_randint(state, 2))
mag_swap(arb_radref(acb_realref(z)), arb_radref(acb_imagref(z)));
a2 = acb_rel_accuracy_bits(z);
if (a1 != a2)
{
flint_printf("FAIL: swapping\n\n");
flint_printf("z = "); acb_print(z); flint_printf("\n\n");
flint_printf("a1 = %wd, a2 = %wd\n\n", a1, a2);
abort();
}
acb_randtest_special(z, state, 1 + n_randint(state, 200), 1 + n_randint(state, 200));
if (arf_cmpabs(arb_midref(acb_realref(z)), arb_midref(acb_imagref(z))) >= 0)
arf_set(arb_midref(x), arb_midref(acb_realref(z)));
else
arf_set(arb_midref(x), arb_midref(acb_imagref(z)));
if (mag_cmp(arb_radref(acb_realref(z)), arb_radref(acb_imagref(z))) >= 0)
mag_set(arb_radref(x), arb_radref(acb_realref(z)));
else
mag_set(arb_radref(x), arb_radref(acb_imagref(z)));
a1 = acb_rel_accuracy_bits(z);
a2 = arb_rel_accuracy_bits(x);
if (a1 != a2)
{
flint_printf("FAIL: acb != arb (2)\n\n");
flint_printf("x = "); arb_print(x); flint_printf("\n\n");
flint_printf("z = "); acb_print(z); flint_printf("\n\n");
flint_printf("a1 = %wd, a2 = %wd\n\n", a1, a2);
abort();
}
arb_clear(x);
acb_clear(z);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
slong
hypgeom_bound(mag_t error, int r,
slong A, slong B, slong K, const mag_t TK, const mag_t z, slong tol_2exp)
{
mag_t Tn, t, u, one, tol, num, den;
slong n, m;
mag_init(Tn);
mag_init(t);
mag_init(u);
mag_init(one);
mag_init(tol);
mag_init(num);
mag_init(den);
mag_one(one);
mag_set_ui_2exp_si(tol, UWORD(1), -tol_2exp);
/* approximate number of needed terms */
n = hypgeom_estimate_terms(z, r, tol_2exp);
/* required for 1 + O(1/k) part to be decreasing */
n = FLINT_MAX(n, K + 1);
/* required for z^k / (k!)^r to be decreasing */
m = hypgeom_root_bound(z, r);
n = FLINT_MAX(n, m);
/* We now have |R(k)| <= G(k) where G(k) is monotonically decreasing,
and can bound the tail using a geometric series as soon
as soon as G(k) < 1. */
/* bound T(n-1) */
hypgeom_term_bound(Tn, TK, K, A, B, r, z, n-1);
while (1)
{
/* bound R(n) */
mag_mul_ui(num, z, n);
mag_mul_ui(num, num, n - B);
mag_set_ui_lower(den, n - A);
mag_mul_ui_lower(den, den, n - 2*B);
if (r != 0)
{
mag_set_ui_lower(u, n);
mag_pow_ui_lower(u, u, r);
mag_mul_lower(den, den, u);
}
mag_div(t, num, den);
/* multiply bound for T(n-1) by bound for R(n) to bound T(n) */
mag_mul(Tn, Tn, t);
/* geometric series termination check */
/* u = max(1-t, 0), rounding down [lower bound] */
mag_sub_lower(u, one, t);
if (!mag_is_zero(u))
{
mag_div(u, Tn, u);
if (mag_cmp(u, tol) < 0)
{
mag_set(error, u);
break;
}
}
/* move on to next term */
n++;
}
mag_clear(Tn);
mag_clear(t);
mag_clear(u);
mag_clear(one);
mag_clear(tol);
mag_clear(num);
mag_clear(den);
return n;
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("root_bound_fujiwara....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
{
arb_poly_t a;
arb_ptr roots;
arb_t t;
mag_t mag1, mag2;
slong i, deg, prec;
prec = 10 + n_randint(state, 400);
deg = n_randint(state, 10);
arb_init(t);
arb_poly_init(a);
mag_init(mag1);
mag_init(mag2);
roots = _arb_vec_init(deg);
for (i = 0; i < deg; i++)
arb_randtest(roots + i, state, prec, 1 + n_randint(state, 20));
arb_poly_product_roots(a, roots, deg, prec);
arb_randtest(t, state, prec, 1 + n_randint(state, 20));
arb_poly_scalar_mul(a, a, t, prec);
arb_poly_root_bound_fujiwara(mag1, a);
for (i = 0; i < deg; i++)
{
arb_get_mag(mag2, roots + i);
/* arb_get_mag gives an upper bound which due to rounding
could be larger than mag1, so we pick a slightly
smaller number */
mag_mul_ui(mag2, mag2, 10000);
mag_div_ui(mag2, mag2, 10001);
if (mag_cmp(mag2, mag1) > 0)
{
flint_printf("FAIL\n");
flint_printf("a = "); arb_poly_printd(a, 15); flint_printf("\n\n");
flint_printf("root = "); arb_printd(roots + i, 15); flint_printf("\n\n");
flint_printf("mag1 = "); mag_printd(mag1, 10); flint_printf("\n\n");
flint_printf("mag2 = "); mag_printd(mag2, 10); flint_printf("\n\n");
abort();
}
}
_arb_vec_clear(roots, deg);
arb_clear(t);
arb_poly_clear(a);
mag_clear(mag1);
mag_clear(mag2);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("frobenius_norm....");
fflush(stdout);
flint_randinit(state);
/* compare to the exact rational norm */
for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
{
fmpq_mat_t Q;
fmpq_t q;
arb_mat_t A;
slong n, qbits, prec;
n = n_randint(state, 8);
qbits = 1 + n_randint(state, 100);
prec = 2 + n_randint(state, 200);
fmpq_mat_init(Q, n, n);
fmpq_init(q);
arb_mat_init(A, n, n);
fmpq_mat_randtest(Q, state, qbits);
_fmpq_mat_sum_of_squares(q, Q);
arb_mat_set_fmpq_mat(A, Q, prec);
/* check that the arb interval contains the exact value */
{
arb_t a;
arb_init(a);
arb_mat_frobenius_norm(a, A, prec);
arb_mul(a, a, a, prec);
if (!arb_contains_fmpq(a, q))
{
flint_printf("FAIL (containment, iter = %wd)\n", iter);
flint_printf("n = %wd, prec = %wd\n", n, prec);
flint_printf("\n");
flint_printf("Q = \n");
fmpq_mat_print(Q);
flint_printf("\n\n");
flint_printf("frobenius_norm(Q)^2 = \n");
fmpq_print(q);
flint_printf("\n\n");
flint_printf("A = \n");
arb_mat_printd(A, 15);
flint_printf("\n\n");
flint_printf("frobenius_norm(A)^2 = \n");
arb_printd(a, 15);
flint_printf("\n\n");
flint_printf("frobenius_norm(A)^2 = \n");
arb_print(a);
flint_printf("\n\n");
abort();
}
arb_clear(a);
}
/* check that the upper bound is not less than the exact value */
{
mag_t b;
fmpq_t y;
mag_init(b);
fmpq_init(y);
arb_mat_bound_frobenius_norm(b, A);
mag_mul(b, b, b);
mag_get_fmpq(y, b);
if (fmpq_cmp(q, y) > 0)
{
flint_printf("FAIL (bound, iter = %wd)\n", iter);
flint_printf("n = %wd, prec = %wd\n", n, prec);
flint_printf("\n");
flint_printf("Q = \n");
fmpq_mat_print(Q);
flint_printf("\n\n");
flint_printf("frobenius_norm(Q)^2 = \n");
fmpq_print(q);
flint_printf("\n\n");
flint_printf("A = \n");
arb_mat_printd(A, 15);
flint_printf("\n\n");
flint_printf("bound_frobenius_norm(A)^2 = \n");
mag_printd(b, 15);
flint_printf("\n\n");
flint_printf("bound_frobenius_norm(A)^2 = \n");
mag_print(b);
flint_printf("\n\n");
abort();
}
mag_clear(b);
fmpq_clear(y);
}
fmpq_mat_clear(Q);
fmpq_clear(q);
arb_mat_clear(A);
}
/* check trace(A^T A) = frobenius_norm(A)^2 */
for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
{
slong m, n, prec;
arb_mat_t A, AT, ATA;
arb_t t;
prec = 2 + n_randint(state, 200);
m = n_randint(state, 10);
n = n_randint(state, 10);
arb_mat_init(A, m, n);
arb_mat_init(AT, n, m);
arb_mat_init(ATA, n, n);
arb_init(t);
arb_mat_randtest(A, state, 2 + n_randint(state, 100), 10);
arb_mat_transpose(AT, A);
arb_mat_mul(ATA, AT, A, prec);
arb_mat_trace(t, ATA, prec);
arb_sqrt(t, t, prec);
/* check the norm bound */
{
mag_t low, frobenius;
mag_init(low);
arb_get_mag_lower(low, t);
mag_init(frobenius);
arb_mat_bound_frobenius_norm(frobenius, A);
if (mag_cmp(low, frobenius) > 0)
{
flint_printf("FAIL (bound)\n", iter);
flint_printf("m = %wd, n = %wd, prec = %wd\n", m, n, prec);
flint_printf("\n");
flint_printf("A = \n");
arb_mat_printd(A, 15);
flint_printf("\n\n");
flint_printf("lower(sqrt(trace(A^T A))) = \n");
mag_printd(low, 15);
flint_printf("\n\n");
flint_printf("bound_frobenius_norm(A) = \n");
mag_printd(frobenius, 15);
flint_printf("\n\n");
abort();
}
mag_clear(low);
mag_clear(frobenius);
}
/* check the norm interval */
{
arb_t frobenius;
arb_init(frobenius);
arb_mat_frobenius_norm(frobenius, A, prec);
if (!arb_overlaps(t, frobenius))
{
flint_printf("FAIL (overlap)\n", iter);
flint_printf("m = %wd, n = %wd, prec = %wd\n", m, n, prec);
flint_printf("\n");
flint_printf("A = \n");
arb_mat_printd(A, 15);
flint_printf("\n\n");
flint_printf("sqrt(trace(A^T A)) = \n");
arb_printd(t, 15);
flint_printf("\n\n");
flint_printf("frobenius_norm(A) = \n");
arb_printd(frobenius, 15);
flint_printf("\n\n");
abort();
}
arb_clear(frobenius);
}
arb_mat_clear(A);
arb_mat_clear(AT);
arb_mat_clear(ATA);
arb_clear(t);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("2f1_continuation....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 1000 * arb_test_multiplier(); iter++)
{
acb_t a, b, c, z1, z2, f1, f2, g1, g2, h1, h2, aa, bb, cc;
mag_t d0, d1, dt;
slong prec;
int regularized, ebits;
acb_init(a); acb_init(b); acb_init(c);
acb_init(aa); acb_init(bb); acb_init(cc);
acb_init(z1); acb_init(z2);
acb_init(f1); acb_init(f2);
acb_init(g1); acb_init(g2);
acb_init(h1); acb_init(h2);
mag_init(d0); mag_init(d1); mag_init(dt);
prec = 2 + n_randint(state, 300);
ebits = 10;
regularized = n_randint(state, 2);
acb_randtest_param(a, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits / 2));
acb_randtest_param(b, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits / 2));
acb_randtest_param(c, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits / 2));
acb_randtest(h1, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
acb_randtest(h2, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
do {
int left, upper, lower;
acb_randtest_param(z1, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
acb_randtest_param(z2, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
/* we test both convergent and non-convergent cases, but
try to be more efficient by generating more convergent cases */
if (n_randint(state, 2))
{
acb_sub_ui(aa, z1, 1, prec);
acb_get_mag(d0, z1);
acb_get_mag(d1, aa);
acb_get_mag(dt, z2);
if (mag_cmp(dt, d0) >= 0 || mag_cmp(dt, d1) >= 0)
continue;
}
acb_add(z2, z1, z2, prec);
/* for the test, don't cross the branch cut */
acb_sub_ui(aa, z1, 1, prec);
acb_sub_ui(bb, z2, 1, prec);
left = arb_is_negative(acb_realref(aa)) && arb_is_negative(acb_realref(bb));
upper = arb_is_positive(acb_imagref(aa)) && arb_is_positive(acb_imagref(bb));
lower = arb_is_nonpositive(acb_imagref(aa)) && arb_is_nonpositive(acb_imagref(bb));
if (left || upper || lower)
break;
} while (1);
acb_add_ui(aa, a, 1, prec);
acb_add_ui(bb, b, 1, prec);
acb_add_ui(cc, c, 1, prec);
acb_hypgeom_2f1(f1, a, b, c, z1, regularized, prec);
acb_hypgeom_2f1(f2, aa, bb, cc, z1, regularized, prec);
acb_mul(f2, f2, a, prec);
acb_mul(f2, f2, b, prec);
if (!regularized)
acb_div(f2, f2, c, prec);
acb_hypgeom_2f1_continuation(h1, h2, a, b, c, z1, z2, f1, f2, prec);
if (acb_is_finite(h1) || acb_is_finite(h2))
{
acb_hypgeom_2f1(g1, a, b, c, z2, regularized, prec);
acb_hypgeom_2f1(g2, aa, bb, cc, z2, regularized, prec);
acb_mul(g2, g2, a, prec);
acb_mul(g2, g2, b, prec);
if (!regularized)
acb_div(g2, g2, c, prec);
if (!acb_overlaps(g1, h1) || !acb_overlaps(g2, h2))
{
flint_printf("FAIL: consistency\n\n");
flint_printf("regularized = %d, prec = %wd\n\n", regularized, prec);
flint_printf("a = "); acb_printd(a, 30); flint_printf("\n\n");
flint_printf("b = "); acb_printd(b, 30); flint_printf("\n\n");
flint_printf("c = "); acb_printd(c, 30); flint_printf("\n\n");
flint_printf("z1 = "); acb_printd(z1, 30); flint_printf("\n\n");
flint_printf("z2 = "); acb_printd(z2, 30); flint_printf("\n\n");
flint_printf("F(a,b,c,z1) and F'(a,b,c,z1):\n");
flint_printf("f1 = "); acb_printd(f1, 30); flint_printf("\n\n");
flint_printf("f2 = "); acb_printd(f2, 30); flint_printf("\n\n");
flint_printf("F(a,b,c,z2) and F'(a,b,c,z2):\n");
flint_printf("g1 = "); acb_printd(g1, 30); flint_printf("\n\n");
flint_printf("g2 = "); acb_printd(g2, 30); flint_printf("\n\n");
flint_printf("Computed F and F':\n");
flint_printf("h1 = "); acb_printd(h1, 30); flint_printf("\n\n");
flint_printf("h2 = "); acb_printd(h2, 30); flint_printf("\n\n");
flint_abort();
}
}
acb_clear(a); acb_clear(b); acb_clear(c);
acb_clear(aa); acb_clear(bb); acb_clear(cc);
acb_clear(z1); acb_clear(z2);
acb_clear(f1); acb_clear(f2);
acb_clear(g1); acb_clear(g2);
acb_clear(h1); acb_clear(h2);
mag_clear(d0); mag_clear(d1); mag_clear(dt);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
/* computes the factors that are independent of n (all are upper bounds) */
void
acb_hypgeom_u_asymp_bound_factors(int * R, mag_t alpha,
mag_t nu, mag_t sigma, mag_t rho, mag_t zinv,
const acb_t a, const acb_t b, const acb_t z)
{
mag_t r, u, zre, zim, zlo, sigma_prime;
acb_t t;
mag_init(r);
mag_init(u);
mag_init(zre);
mag_init(zim);
mag_init(zlo);
mag_init(sigma_prime);
acb_init(t);
/* lower bounds for |re(z)|, |im(z)|, |z| */
arb_get_mag_lower(zre, acb_realref(z));
arb_get_mag_lower(zim, acb_imagref(z));
acb_get_mag_lower(zlo, z); /* todo: hypot */
/* upper bound for 1/|z| */
mag_one(u);
mag_div(zinv, u, zlo);
/* upper bound for r = |b - 2a| */
acb_mul_2exp_si(t, a, 1);
acb_sub(t, b, t, MAG_BITS);
acb_get_mag(r, t);
/* determine region */
*R = 0;
if (mag_cmp(zlo, r) >= 0)
{
int znonneg = arb_is_nonnegative(acb_realref(z));
if (znonneg && mag_cmp(zre, r) >= 0)
{
*R = 1;
}
else if (mag_cmp(zim, r) >= 0 || znonneg)
{
*R = 2;
}
else
{
mag_mul_2exp_si(u, r, 1);
if (mag_cmp(zlo, u) >= 0)
*R = 3;
}
}
if (R == 0)
{
mag_inf(alpha);
mag_inf(nu);
mag_inf(sigma);
mag_inf(rho);
}
else
{
/* sigma = |(b-2a)/z| */
mag_mul(sigma, r, zinv);
/* nu = (1/2 + 1/2 sqrt(1-4 sigma^2))^(-1/2) <= 1 + 2 sigma^2 */
if (mag_cmp_2exp_si(sigma, -1) <= 0)
{
mag_mul(nu, sigma, sigma);
mag_mul_2exp_si(nu, nu, 1);
mag_one(u);
mag_add(nu, nu, u);
}
else
{
mag_inf(nu);
}
/* modified sigma for alpha, beta, rho when in R3 */
if (*R == 3)
mag_mul(sigma_prime, sigma, nu);
else
mag_set(sigma_prime, sigma);
/* alpha = 1/(1-sigma') */
mag_one(alpha);
mag_sub_lower(alpha, alpha, sigma_prime);
mag_one(u);
mag_div(alpha, u, alpha);
/* rho = |2a^2-2ab+b|/2 + sigma'*(1+sigma'/4)/(1-sigma')^2 */
mag_mul_2exp_si(rho, sigma_prime, -2);
mag_one(u);
mag_add(rho, rho, u);
mag_mul(rho, rho, sigma_prime);
mag_mul(rho, rho, alpha);
mag_mul(rho, rho, alpha);
acb_sub(t, a, b, MAG_BITS);
acb_mul(t, t, a, MAG_BITS);
acb_mul_2exp_si(t, t, 1);
acb_add(t, t, b, MAG_BITS);
acb_get_mag(u, t);
mag_mul_2exp_si(u, u, -1);
mag_add(rho, rho, u);
}
mag_clear(r);
mag_clear(u);
mag_clear(zre);
mag_clear(zim);
mag_clear(zlo);
mag_clear(sigma_prime);
acb_clear(t);
}
void
acb_hypgeom_2f1_continuation(acb_t res, acb_t res1,
const acb_t a, const acb_t b, const acb_t c, const acb_t y,
const acb_t z, const acb_t f0, const acb_t f1, long prec)
{
mag_t A, nu, N, w, err, err1, R, T, goal;
acb_t x;
long j, k;
mag_init(A);
mag_init(nu);
mag_init(N);
mag_init(err);
mag_init(err1);
mag_init(w);
mag_init(R);
mag_init(T);
mag_init(goal);
acb_init(x);
bound(A, nu, N, a, b, c, y, f0, f1);
acb_sub(x, z, y, prec);
/* |T(k)| <= A * binomial(N+k, k) * nu^k * |x|^k */
acb_get_mag(w, x);
mag_mul(w, w, nu); /* w = nu |x| */
mag_mul_2exp_si(goal, A, -prec-2);
/* bound for T(0) */
mag_set(T, A);
mag_inf(R);
for (k = 1; k < 100 * prec; k++)
{
/* T(k) = T(k) * R(k), R(k) = (N+k)/k * w = (1 + N/k) w */
mag_div_ui(R, N, k);
mag_add_ui(R, R, 1);
mag_mul(R, R, w);
/* T(k) */
mag_mul(T, T, R);
if (mag_cmp(T, goal) <= 0 && mag_cmp_2exp_si(R, 0) < 0)
break;
}
/* T(k) [1 + R + R^2 + R^3 + ...] */
mag_geom_series(err, R, 0);
mag_mul(err, T, err);
/* Now compute T, R for the derivative */
/* Coefficients are A * (k+1) * binomial(N+k+1, k+1) */
mag_add_ui(T, N, 1);
mag_mul(T, T, A);
mag_inf(R);
for (j = 1; j <= k; j++)
{
mag_add_ui(R, N, k + 1);
mag_div_ui(R, R, k);
mag_mul(R, R, w);
mag_mul(T, T, R);
}
mag_geom_series(err1, R, 0);
mag_mul(err1, T, err1);
if (mag_is_inf(err))
{
acb_indeterminate(res);
acb_indeterminate(res1);
}
else
{
evaluate_sum(res, res1, a, b, c, y, x, f0, f1, k, prec);
acb_add_error_mag(res, err);
acb_add_error_mag(res1, err1);
}
mag_clear(A);
mag_clear(nu);
mag_clear(N);
mag_clear(err);
mag_clear(err1);
mag_clear(w);
mag_clear(R);
mag_clear(T);
mag_clear(goal);
acb_clear(x);
}
