void
acb_real_min(acb_t res, const acb_t x, const acb_t y, int analytic, slong prec)
{
arb_t t;
if (!acb_is_finite(x) || !acb_is_finite(y))
{
acb_indeterminate(res);
return;
}
arb_init(t);
arb_sub(t, acb_realref(x), acb_realref(y), prec);
if (arb_is_positive(t))
acb_set_round(res, y, prec);
else if (arb_is_negative(t))
acb_set_round(res, x, prec);
else if (!analytic)
acb_union(res, x, y, prec);
else
acb_indeterminate(res);
arb_clear(t);
}
void
_acb_poly_zeta_cpx_series(acb_ptr z, const acb_t s, const acb_t a, int deflate, long d, long prec)
{
ulong M, N;
long i;
arf_t bound;
arb_ptr vb;
if (d < 1)
return;
if (!acb_is_finite(s) || !acb_is_finite(a))
{
_acb_vec_indeterminate(z, d);
return;
}
arf_init(bound);
vb = _arb_vec_init(d);
_acb_poly_zeta_em_choose_param(bound, &N, &M, s, a, FLINT_MIN(d, 2), prec, MAG_BITS);
_acb_poly_zeta_em_bound(vb, s, a, N, M, d, MAG_BITS);
_acb_poly_zeta_em_sum(z, s, a, deflate, N, M, d, prec);
for (i = 0; i < d; i++)
{
arb_get_abs_ubound_arf(bound, vb + i, MAG_BITS);
arb_add_error_arf(acb_realref(z + i), bound);
arb_add_error_arf(acb_imagref(z + i), bound);
}
arf_clear(bound);
_arb_vec_clear(vb, d);
}
void
_acb_poly_zeta_cpx_series(acb_ptr z, const acb_t s, const acb_t a, int deflate, slong d, slong prec)
{
ulong M, N;
slong i;
mag_t bound;
arb_ptr vb;
int is_real, const_is_real;
if (d < 1)
return;
if (!acb_is_finite(s) || !acb_is_finite(a))
{
_acb_vec_indeterminate(z, d);
return;
}
is_real = const_is_real = 0;
if (acb_is_real(s) && acb_is_real(a))
{
if (arb_is_positive(acb_realref(a)))
{
is_real = const_is_real = 1;
}
else if (arb_is_int(acb_realref(a)) &&
arb_is_int(acb_realref(s)) &&
arb_is_nonpositive(acb_realref(s)))
{
const_is_real = 1;
}
}
mag_init(bound);
vb = _arb_vec_init(d);
_acb_poly_zeta_em_choose_param(bound, &N, &M, s, a, FLINT_MIN(d, 2), prec, MAG_BITS);
_acb_poly_zeta_em_bound(vb, s, a, N, M, d, MAG_BITS);
_acb_poly_zeta_em_sum(z, s, a, deflate, N, M, d, prec);
for (i = 0; i < d; i++)
{
arb_get_mag(bound, vb + i);
arb_add_error_mag(acb_realref(z + i), bound);
if (!is_real && !(i == 0 && const_is_real))
arb_add_error_mag(acb_imagref(z + i), bound);
}
mag_clear(bound);
_arb_vec_clear(vb, d);
}
/* f(z) = |z^4 + 10z^3 + 19z^2 - 6z - 6| exp(z) (for real z) --
Helfgott's integral on MathOverflow */
int
f_helfgott(acb_ptr res, const acb_t z, void * param, slong order, slong prec)
{
if (order > 1)
flint_abort(); /* Would be needed for Taylor method. */
acb_add_si(res, z, 10, prec);
acb_mul(res, res, z, prec);
acb_add_si(res, res, 19, prec);
acb_mul(res, res, z, prec);
acb_add_si(res, res, -6, prec);
acb_mul(res, res, z, prec);
acb_add_si(res, res, -6, prec);
acb_real_abs(res, res, order != 0, prec);
if (acb_is_finite(res))
{
acb_t t;
acb_init(t);
acb_exp(t, z, prec);
acb_mul(res, res, t, prec);
acb_clear(t);
}
return 0;
}
void
acb_log_sin_pi(acb_t res, const acb_t z, slong prec)
{
if (!acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
if (arb_is_positive(acb_imagref(z)) ||
(arb_is_zero(acb_imagref(z)) && arb_is_negative(acb_realref(z))))
{
acb_log_sin_pi_half(res, z, prec, 1);
}
else if (arb_is_negative(acb_imagref(z)) ||
(arb_is_zero(acb_imagref(z)) && arb_is_positive(acb_realref(z))))
{
acb_log_sin_pi_half(res, z, prec, 0);
}
else
{
acb_t t;
acb_init(t);
acb_log_sin_pi_half(t, z, prec, 1);
acb_log_sin_pi_half(res, z, prec, 0);
arb_union(acb_realref(res), acb_realref(res), acb_realref(t), prec);
arb_union(acb_imagref(res), acb_imagref(res), acb_imagref(t), prec);
acb_clear(t);
}
}
int
f_monster(acb_ptr res, const acb_t z, void * param, slong order, slong prec)
{
acb_t t;
if (order > 1)
flint_abort(); /* Would be needed for Taylor method. */
acb_init(t);
acb_exp(t, z, prec);
acb_real_floor(res, t, order != 0, prec);
if (acb_is_finite(res))
{
acb_sub(res, t, res, prec);
acb_add(t, t, z, prec);
acb_sin(t, t, prec);
acb_mul(res, res, t, prec);
}
acb_clear(t);
return 0;
}
int
f_horror(acb_ptr res, const acb_t z, void * param, slong order, slong prec)
{
acb_t s, t;
if (order > 1)
flint_abort(); /* Would be needed for Taylor method. */
acb_init(s);
acb_init(t);
acb_real_floor(res, z, order != 0, prec);
if (acb_is_finite(res))
{
acb_sub(res, z, res, prec);
acb_set_d(t, 0.5);
acb_sub(res, res, t, prec);
acb_sin_cos(s, t, z, prec);
acb_real_max(s, s, t, order != 0, prec);
acb_mul(res, res, s, prec);
}
acb_clear(s);
acb_clear(t);
return 0;
}
void
acb_hypgeom_erf(acb_t res, const acb_t z, slong prec)
{
double x, y, absz2, logz;
slong prec2;
if (!acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
if (acb_is_zero(z))
{
acb_zero(res);
return;
}
if ((arf_cmpabs_2exp_si(arb_midref(acb_realref(z)), 0) < 0 &&
arf_cmpabs_2exp_si(arb_midref(acb_imagref(z)), 0) < 0))
{
acb_hypgeom_erf_1f1a(res, z, prec);
return;
}
if ((arf_cmpabs_2exp_si(arb_midref(acb_realref(z)), 64) > 0 ||
arf_cmpabs_2exp_si(arb_midref(acb_imagref(z)), 64) > 0))
{
acb_hypgeom_erf_asymp(res, z, prec, prec);
return;
}
x = arf_get_d(arb_midref(acb_realref(z)), ARF_RND_DOWN);
y = arf_get_d(arb_midref(acb_imagref(z)), ARF_RND_DOWN);
absz2 = x * x + y * y;
logz = 0.5 * log(absz2);
if (logz - absz2 < -(prec + 8) * 0.69314718055994530942)
{
/* If the asymptotic term is small, we can
compute with reduced precision */
prec2 = FLINT_MIN(prec + 4 + (y*y - x*x - logz) * 1.4426950408889634074, (double) prec);
prec2 = FLINT_MAX(8, prec2);
prec2 = FLINT_MIN(prec2, prec);
acb_hypgeom_erf_asymp(res, z, prec, prec2);
}
else if (arf_cmpabs(arb_midref(acb_imagref(z)), arb_midref(acb_realref(z))) > 0)
{
acb_hypgeom_erf_1f1a(res, z, prec);
}
else
{
acb_hypgeom_erf_1f1b(res, z, prec);
}
}
void
acb_hypgeom_fresnel(acb_t res1, acb_t res2, const acb_t z, int normalized, slong prec)
{
slong wp;
acb_t w;
arb_t c;
if (!acb_is_finite(z))
{
if (res1 != NULL) acb_indeterminate(res1);
if (res2 != NULL) acb_indeterminate(res2);
return;
}
acb_init(w);
arb_init(c);
wp = prec + 8;
if (normalized)
{
arb_const_pi(c, wp);
arb_sqrt(c, c, wp);
arb_mul_2exp_si(c, c, -1);
acb_mul_arb(w, z, c, wp);
acb_hypgeom_fresnel_erf_error(res1, res2, w, wp);
}
else
{
arb_sqrt_ui(c, 2, wp);
arb_mul_2exp_si(c, c, -1);
acb_mul_arb(w, z, c, wp);
acb_hypgeom_fresnel_erf_error(res1, res2, w, wp);
arb_const_pi(c, wp);
arb_mul_2exp_si(c, c, -1);
arb_sqrt(c, c, wp);
if (res1 != NULL) acb_mul_arb(res1, res1, c, wp);
if (res2 != NULL) acb_mul_arb(res2, res2, c, wp);
}
if (res1 != NULL)
{
acb_mul_2exp_si(res1, res1, -2);
acb_set_round(res1, res1, prec);
}
if (res2 != NULL)
{
acb_mul_2exp_si(res2, res2, -2);
acb_set_round(res2, res2, prec);
}
acb_clear(w);
arb_clear(c);
}
void
arb_hypgeom_bessel_jy(arb_t res1, arb_t res2, const arb_t nu, const arb_t z, slong prec)
{
acb_t t, u;
acb_init(t);
acb_init(u);
arb_set(acb_realref(t), nu);
arb_set(acb_realref(u), z);
acb_hypgeom_bessel_jy(t, u, t, u, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res1, acb_realref(t));
else
arb_indeterminate(res1);
if (acb_is_finite(u) && acb_is_real(u))
arb_swap(res2, acb_realref(u));
else
arb_indeterminate(res2);
acb_clear(t);
acb_clear(u);
}
void
acb_lambertw(acb_t res, const acb_t z, const fmpz_t k, int flags, slong prec)
{
acb_t ez1;
if (!acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
if (flags == ACB_LAMBERTW_LEFT)
{
acb_lambertw_left(res, z, k, prec);
return;
}
if (flags == ACB_LAMBERTW_MIDDLE)
{
acb_lambertw_middle(res, z, prec);
return;
}
if (acb_contains_zero(z) && !fmpz_is_zero(k))
{
acb_indeterminate(res);
return;
}
acb_init(ez1);
/* precompute z*e + 1 */
arb_const_e(acb_realref(ez1), prec);
acb_mul(ez1, ez1, z, prec);
acb_add_ui(ez1, ez1, 1, prec);
/* Compute standard branches */
/* use real code when possible */
if (acb_is_real(z) && arb_is_positive(acb_realref(ez1)) &&
(fmpz_is_zero(k) ||
(fmpz_equal_si(k, -1) && arb_is_negative(acb_realref(z)))))
{
arb_lambertw(acb_realref(res), acb_realref(z), !fmpz_is_zero(k), prec);
arb_zero(acb_imagref(res));
}
else
{
_acb_lambertw(res, z, ez1, k, flags, prec);
}
acb_clear(ez1);
}
void
arb_hypgeom_gamma_upper(arb_t res, const arb_t s, const arb_t z, int regularized, slong prec)
{
acb_t t, u;
acb_init(t);
acb_init(u);
arb_set(acb_realref(t), s);
arb_set(acb_realref(u), z);
acb_hypgeom_gamma_upper(t, t, u, regularized, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res, acb_realref(t));
else
arb_indeterminate(res);
acb_clear(t);
acb_clear(u);
}
void
arb_hypgeom_hermite_h(arb_t res, const arb_t nu, const arb_t z, slong prec)
{
acb_t t, u;
acb_init(t);
acb_init(u);
arb_set(acb_realref(t), nu);
arb_set(acb_realref(u), z);
acb_hypgeom_hermite_h(t, t, u, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res, acb_realref(t));
else
arb_indeterminate(res);
acb_clear(t);
acb_clear(u);
}
void
arb_hypgeom_pfq(arb_t res, arb_srcptr a, slong p, arb_srcptr b, slong q, const arb_t z, int regularized, slong prec)
{
acb_ptr t;
slong i;
t = _acb_vec_init(p + q + 1);
for (i = 0; i < p; i++)
arb_set(acb_realref(t + i), a + i);
for (i = 0; i < q; i++)
arb_set(acb_realref(t + p + i), b + i);
arb_set(acb_realref(t + p + q), z);
acb_hypgeom_pfq(t, t, p, t + p, q, t + p + q, regularized, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res, acb_realref(t));
else
arb_indeterminate(res);
_acb_vec_clear(t, p + q + 1);
}
void
arb_hypgeom_beta_lower(arb_t res, const arb_t a, const arb_t b, const arb_t z, int regularized, slong prec)
{
acb_t t, u, v;
acb_init(t);
acb_init(u);
acb_init(v);
arb_set(acb_realref(t), a);
arb_set(acb_realref(u), b);
arb_set(acb_realref(v), z);
acb_hypgeom_beta_lower(t, t, u, v, regularized, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res, acb_realref(t));
else
arb_indeterminate(res);
acb_clear(t);
acb_clear(u);
acb_clear(v);
}
void
arb_hypgeom_legendre_q(arb_t res, const arb_t n, const arb_t m, const arb_t z, int type, slong prec)
{
acb_t t, u, v;
acb_init(t);
acb_init(u);
acb_init(v);
arb_set(acb_realref(t), n);
arb_set(acb_realref(u), m);
arb_set(acb_realref(v), z);
acb_hypgeom_legendre_q(t, t, u, v, type, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res, acb_realref(t));
else
arb_indeterminate(res);
acb_clear(t);
acb_clear(u);
acb_clear(v);
}
int
f_lambertw(acb_ptr res, const acb_t z, void * param, slong order, slong prec)
{
acb_t t;
if (order > 1)
flint_abort(); /* Would be needed for Taylor method. */
acb_init(t);
prec = FLINT_MIN(prec, acb_rel_accuracy_bits(z) + 10);
if (order != 0)
{
/* check for branch cut */
arb_const_e(acb_realref(t), prec);
acb_inv(t, t, prec);
acb_add(t, t, z, prec);
if (arb_contains_zero(acb_imagref(t)) &&
arb_contains_nonpositive(acb_realref(t)))
{
acb_indeterminate(t);
}
}
if (acb_is_finite(t))
{
fmpz_t k;
fmpz_init(k);
acb_lambertw(res, z, k, 0, prec);
fmpz_clear(k);
}
else
{
acb_indeterminate(res);
}
acb_clear(t);
return 0;
}
void
arb_hypgeom_jacobi_p(arb_t res, const arb_t n, const arb_t a, const arb_t b, const arb_t z, slong prec)
{
acb_t t, u, v, w;
acb_init(t);
acb_init(u);
acb_init(v);
acb_init(w);
arb_set(acb_realref(t), n);
arb_set(acb_realref(u), a);
arb_set(acb_realref(v), b);
arb_set(acb_realref(w), z);
acb_hypgeom_jacobi_p(t, t, u, v, w, prec);
if (acb_is_finite(t) && acb_is_real(t))
arb_swap(res, acb_realref(t));
else
arb_indeterminate(res);
acb_clear(t);
acb_clear(u);
acb_clear(v);
acb_clear(w);
}
void
acb_hypgeom_bessel_i_asymp(acb_t res, const acb_t nu, const acb_t z, long prec)
{
acb_t A1, A2, C, U1, U2, s, t, u;
int is_real, is_imag;
acb_init(A1);
acb_init(A2);
acb_init(C);
acb_init(U1);
acb_init(U2);
acb_init(s);
acb_init(t);
acb_init(u);
is_imag = 0;
is_real = acb_is_real(nu) && acb_is_real(z)
&& (acb_is_int(nu) || arb_is_positive(acb_realref(z)));
if (!is_real && arb_is_zero(acb_realref(z)) && acb_is_int(nu))
{
acb_mul_2exp_si(t, nu, -1);
if (acb_is_int(t))
is_real = 1;
else
is_imag = 1;
}
acb_hypgeom_bessel_i_asymp_prefactors(A1, A2, C, nu, z, prec);
/* todo: if Ap ~ 2^a and Am = 2^b and U1 ~ U2 ~ 1, change precision? */
if (!acb_is_finite(A1) || !acb_is_finite(A2) || !acb_is_finite(C))
{
acb_indeterminate(res);
}
else
{
/* s = 1/2 + nu */
acb_one(s);
acb_mul_2exp_si(s, s, -1);
acb_add(s, s, nu, prec);
/* t = 1 + 2 nu */
acb_mul_2exp_si(t, nu, 1);
acb_add_ui(t, t, 1, prec);
acb_mul_2exp_si(u, z, 1);
acb_hypgeom_u_asymp(U1, s, t, u, -1, prec);
acb_neg(u, u);
acb_hypgeom_u_asymp(U2, s, t, u, -1, prec);
acb_mul(res, A1, U1, prec);
acb_addmul(res, A2, U2, prec);
acb_mul(res, res, C, prec);
if (is_real)
arb_zero(acb_imagref(res));
if (is_imag)
arb_zero(acb_realref(res));
}
acb_clear(A1);
acb_clear(A2);
acb_clear(C);
acb_clear(U1);
acb_clear(U2);
acb_clear(s);
acb_clear(t);
acb_clear(u);
}
void
_acb_poly_digamma_series(acb_ptr res, acb_srcptr h, slong hlen, slong len, slong prec)
{
int reflect;
slong i, r, n, rflen, wp;
acb_t zr;
acb_ptr t, u, v;
hlen = FLINT_MIN(hlen, len);
if (hlen == 1)
{
acb_digamma(res, h, prec);
if (acb_is_finite(res))
_acb_vec_zero(res + 1, len - 1);
else
_acb_vec_indeterminate(res + 1, len - 1);
return;
}
/* use real code for real input */
if (_acb_vec_is_real(h, hlen))
{
arb_ptr tmp = _arb_vec_init(len);
for (i = 0; i < hlen; i++)
arb_set(tmp + i, acb_realref(h + i));
_arb_poly_digamma_series(tmp, tmp, hlen, len, prec);
for (i = 0; i < len; i++)
acb_set_arb(res + i, tmp + i);
_arb_vec_clear(tmp, len);
return;
}
wp = prec + FLINT_BIT_COUNT(prec);
t = _acb_vec_init(len + 1);
u = _acb_vec_init(len + 1);
v = _acb_vec_init(len + 1);
acb_init(zr);
/* use Stirling series */
acb_gamma_stirling_choose_param(&reflect, &r, &n, h, 1, 1, wp);
/* psi(x) = psi((1-x)+r) - h(1-x,r) - pi*cot(pi*x) */
if (reflect)
{
if (r != 0) /* otherwise t = 0 */
{
acb_sub_ui(v, h, 1, wp);
acb_neg(v, v);
acb_one(v + 1);
rflen = FLINT_MIN(len + 1, r + 1);
_acb_poly_rising_ui_series(u, v, 2, r, rflen, wp);
_acb_poly_derivative(v, u, rflen, wp);
_acb_poly_div_series(t, v, rflen - 1, u, rflen, len, wp);
for (i = 1; i < len; i += 2)
acb_neg(t + i, t + i);
}
acb_sub_ui(zr, h, r + 1, wp);
acb_neg(zr, zr);
_acb_poly_gamma_stirling_eval2(u, zr, n, len + 1, 1, wp);
for (i = 1; i < len; i += 2)
acb_neg(u + i, u + i);
_acb_vec_sub(u, u, t, len, wp);
acb_set(t, h);
acb_one(t + 1);
_acb_poly_cot_pi_series(t, t, 2, len, wp);
acb_const_pi(v, wp);
_acb_vec_scalar_mul(t, t, len, v, wp);
_acb_vec_sub(u, u, t, len, wp);
}
else
{
if (r == 0)
{
acb_add_ui(zr, h, r, wp);
_acb_poly_gamma_stirling_eval2(u, zr, n, len + 1, 1, wp);
}
else
{
acb_set(v, h);
acb_one(v + 1);
rflen = FLINT_MIN(len + 1, r + 1);
_acb_poly_rising_ui_series(u, v, 2, r, rflen, wp);
_acb_poly_derivative(v, u, rflen, wp);
_acb_poly_div_series(t, v, rflen - 1, u, rflen, len, wp);
acb_add_ui(zr, h, r, wp);
_acb_poly_gamma_stirling_eval2(u, zr, n, len + 1, 1, wp);
_acb_vec_sub(u, u, t, len, wp);
}
}
/* compose with nonconstant part */
acb_zero(t);
_acb_vec_set(t + 1, h + 1, hlen - 1);
_acb_poly_compose_series(res, u, len, t, hlen, len, prec);
acb_clear(zr);
_acb_vec_clear(t, len + 1);
_acb_vec_clear(u, len + 1);
_acb_vec_clear(v, len + 1);
}
void
acb_dirichlet_zeta_rs_mid(acb_t res, const acb_t s, slong K, slong prec)
{
acb_t R1, R2, X, t;
slong wp;
if (arf_sgn(arb_midref(acb_imagref(s))) < 0)
{
acb_init(t);
acb_conj(t, s);
acb_dirichlet_zeta_rs(res, t, K, prec);
acb_conj(res, res);
acb_clear(t);
return;
}
acb_init(R1);
acb_init(R2);
acb_init(X);
acb_init(t);
/* rs_r increases the precision internally */
wp = prec;
acb_dirichlet_zeta_rs_r(R1, s, K, wp);
if (arb_is_exact(acb_realref(s)) &&
(arf_cmp_2exp_si(arb_midref(acb_realref(s)), -1) == 0))
{
acb_conj(R2, R1);
}
else
{
/* conj(R(conj(1-s))) */
arb_sub_ui(acb_realref(t), acb_realref(s), 1, 10 * wp);
arb_neg(acb_realref(t), acb_realref(t));
arb_set(acb_imagref(t), acb_imagref(s));
acb_dirichlet_zeta_rs_r(R2, t, K, wp);
acb_conj(R2, R2);
}
if (acb_is_finite(R1) && acb_is_finite(R2))
{
wp += 10 + arf_abs_bound_lt_2exp_si(arb_midref(acb_imagref(s)));
wp = FLINT_MAX(wp, 10);
/* X = pi^(s-1/2) gamma((1-s)/2) rgamma(s/2)
= (2 pi)^s rgamma(s) / (2 cos(pi s / 2)) */
acb_rgamma(X, s, wp);
acb_const_pi(t, wp);
acb_mul_2exp_si(t, t, 1);
acb_pow(t, t, s, wp);
acb_mul(X, X, t, wp);
acb_mul_2exp_si(t, s, -1);
acb_cos_pi(t, t, wp);
acb_mul_2exp_si(t, t, 1);
acb_div(X, X, t, wp);
acb_mul(R2, R2, X, wp);
}
/* R1 + X * R2 */
acb_add(res, R1, R2, prec);
acb_clear(R1);
acb_clear(R2);
acb_clear(X);
acb_clear(t);
}
void
acb_dirichlet_l(acb_t res, const acb_t s,
const dirichlet_group_t G, const dirichlet_char_t chi, slong prec)
{
if (!acb_is_finite(s))
{
acb_indeterminate(res);
}
else if (G == NULL || G->q == 1)
{
acb_dirichlet_zeta(res, s, prec);
}
else if (dirichlet_char_is_primitive(G, chi) &&
(arf_cmp_d(arb_midref(acb_realref(s)), -0.5) < 0 ||
(G->q != 1 && dirichlet_parity_char(G, chi) == 0 &&
arf_cmpabs_d(arb_midref(acb_imagref(s)), 0.125) < 0 &&
arf_cmp_d(arb_midref(acb_realref(s)), 0.125) < 0)))
{
/* use functional equation */
acb_t t, u, v;
int parity;
ulong q;
parity = dirichlet_parity_char(G, chi);
q = G->q;
acb_init(t);
acb_init(u);
acb_init(v);
/* gamma((1-s+p)/2) / gamma((s+p)/2) */
acb_add_ui(t, s, parity, prec);
acb_mul_2exp_si(t, t, -1);
acb_rgamma(t, t, prec);
if (!acb_is_zero(t)) /* assumes q != 1 when s = 0 */
{
acb_neg(u, s);
acb_add_ui(u, u, 1 + parity, prec);
acb_mul_2exp_si(u, u, -1);
acb_gamma(u, u, prec);
acb_mul(t, t, u, prec);
/* epsilon */
acb_dirichlet_root_number(u, G, chi, prec);
acb_mul(t, t, u, prec);
/* (pi/q)^(s-1/2) */
acb_const_pi(u, prec);
acb_div_ui(u, u, q, prec);
acb_set_d(v, -0.5);
acb_add(v, v, s, prec);
acb_pow(u, u, v, prec);
acb_mul(t, t, u, prec);
acb_sub_ui(u, s, 1, prec);
acb_neg(u, u);
acb_conj(u, u);
acb_dirichlet_l_general(u, u, G, chi, prec);
acb_conj(u, u);
acb_mul(t, t, u, prec);
if (dirichlet_char_is_real(G, chi) && acb_is_real(s))
arb_zero(acb_imagref(t));
}
acb_set(res, t);
acb_clear(t);
acb_clear(u);
acb_clear(v);
}
else
{
acb_dirichlet_l_general(res, s, G, chi, prec);
}
}
void
acb_hypgeom_2f1(acb_t res, const acb_t a, const acb_t b,
const acb_t c, const acb_t z, int flags, slong prec)
{
int algorithm, regularized;
regularized = flags & ACB_HYPGEOM_2F1_REGULARIZED;
if (!acb_is_finite(a) || !acb_is_finite(b) || !acb_is_finite(c) || !acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
if (acb_is_zero(z))
{
if (regularized)
acb_rgamma(res, c, prec);
else
acb_one(res);
return;
}
if (regularized && acb_is_int(c) && arb_is_nonpositive(acb_realref(c)))
{
if ((acb_is_int(a) && arb_is_nonpositive(acb_realref(a)) &&
arf_cmp(arb_midref(acb_realref(a)), arb_midref(acb_realref(c))) >= 0) ||
(acb_is_int(b) && arb_is_nonpositive(acb_realref(b)) &&
arf_cmp(arb_midref(acb_realref(b)), arb_midref(acb_realref(c))) >= 0))
{
acb_zero(res);
return;
}
}
if (regularized && acb_eq(a, c))
{
_acb_hypgeom_2f1r_reduced(res, b, c, z, prec);
return;
}
if (regularized && acb_eq(b, c))
{
_acb_hypgeom_2f1r_reduced(res, a, c, z, prec);
return;
}
/* polynomial */
if (acb_is_int(a) && arf_sgn(arb_midref(acb_realref(a))) <= 0 &&
arf_cmpabs_ui(arb_midref(acb_realref(a)), prec) < 0)
{
acb_hypgeom_2f1_direct(res, a, b, c, z, regularized, prec);
return;
}
/* polynomial */
if (acb_is_int(b) && arf_sgn(arb_midref(acb_realref(b))) <= 0 &&
arf_cmpabs_ui(arb_midref(acb_realref(b)), prec) < 0)
{
acb_hypgeom_2f1_direct(res, a, b, c, z, regularized, prec);
return;
}
/* Try to reduce to a polynomial case using the Pfaff transformation */
/* TODO: look at flags for integer c-b, c-a here, even when c is nonexact */
if (acb_is_exact(c))
{
acb_t t;
acb_init(t);
acb_sub(t, c, b, prec);
if (acb_is_int(t) && arb_is_nonpositive(acb_realref(t)))
{
acb_hypgeom_2f1_transform(res, a, b, c, z, flags, 1, prec);
acb_clear(t);
return;
}
acb_sub(t, c, a, prec);
if (acb_is_int(t) && arb_is_nonpositive(acb_realref(t)))
{
int f1, f2;
/* When swapping a, b, also swap the flags. */
f1 = flags & ACB_HYPGEOM_2F1_AC;
f2 = flags & ACB_HYPGEOM_2F1_BC;
flags &= ~ACB_HYPGEOM_2F1_AC;
flags &= ~ACB_HYPGEOM_2F1_BC;
if (f1) flags |= ACB_HYPGEOM_2F1_BC;
if (f2) flags |= ACB_HYPGEOM_2F1_AC;
acb_hypgeom_2f1_transform(res, b, a, c, z, flags, 1, prec);
acb_clear(t);
return;
}
acb_clear(t);
}
/* special value at z = 1 */
if (acb_is_one(z))
{
acb_t t, u, v;
acb_init(t);
acb_init(u);
acb_init(v);
acb_sub(t, c, a, prec);
acb_sub(u, c, b, prec);
acb_sub(v, t, b, prec);
if (arb_is_positive(acb_realref(v)))
{
acb_rgamma(t, t, prec);
acb_rgamma(u, u, prec);
acb_mul(t, t, u, prec);
acb_gamma(v, v, prec);
acb_mul(t, t, v, prec);
if (!regularized)
{
acb_gamma(v, c, prec);
acb_mul(t, t, v, prec);
}
acb_set(res, t);
}
else
{
acb_indeterminate(res);
}
acb_clear(t);
acb_clear(u);
acb_clear(v);
return;
}
algorithm = acb_hypgeom_2f1_choose(z);
if (algorithm == 0)
{
acb_hypgeom_2f1_direct(res, a, b, c, z, regularized, prec);
}
else if (algorithm >= 1 && algorithm <= 5)
{
acb_hypgeom_2f1_transform(res, a, b, c, z, flags, algorithm, prec);
}
else
{
acb_hypgeom_2f1_corner(res, a, b, c, z, regularized, prec);
}
}
void
_acb_poly_lgamma_series(acb_ptr res, acb_srcptr h, slong hlen, slong len, slong prec)
{
int reflect;
slong i, r, n, wp;
acb_t zr;
acb_ptr t, u;
hlen = FLINT_MIN(hlen, len);
if (hlen == 1)
{
acb_lgamma(res, h, prec);
if (acb_is_finite(res))
_acb_vec_zero(res + 1, len - 1);
else
_acb_vec_indeterminate(res + 1, len - 1);
return;
}
if (len == 2)
{
acb_t v;
acb_init(v);
acb_set(v, h + 1);
acb_digamma(res + 1, h, prec);
acb_lgamma(res, h, prec);
acb_mul(res + 1, res + 1, v, prec);
acb_clear(v);
return;
}
/* use real code for real input and output */
if (_acb_vec_is_real(h, hlen) && arb_is_positive(acb_realref(h)))
{
arb_ptr tmp = _arb_vec_init(len);
for (i = 0; i < hlen; i++)
arb_set(tmp + i, acb_realref(h + i));
_arb_poly_lgamma_series(tmp, tmp, hlen, len, prec);
for (i = 0; i < len; i++)
acb_set_arb(res + i, tmp + i);
_arb_vec_clear(tmp, len);
return;
}
wp = prec + FLINT_BIT_COUNT(prec);
t = _acb_vec_init(len);
u = _acb_vec_init(len);
acb_init(zr);
/* use Stirling series */
acb_gamma_stirling_choose_param(&reflect, &r, &n, h, 1, 0, wp);
if (reflect)
{
/* log gamma(h+x) = log rf(1-(h+x), r) - log gamma(1-(h+x)+r) - log sin(pi (h+x)) + log(pi) */
if (r != 0) /* otherwise t = 0 */
{
acb_sub_ui(u, h, 1, wp);
acb_neg(u, u);
_log_rising_ui_series(t, u, r, len, wp);
for (i = 1; i < len; i += 2)
acb_neg(t + i, t + i);
}
acb_sub_ui(u, h, 1, wp);
acb_neg(u, u);
acb_add_ui(zr, u, r, wp);
_acb_poly_gamma_stirling_eval(u, zr, n, len, wp);
for (i = 1; i < len; i += 2)
acb_neg(u + i, u + i);
_acb_vec_sub(t, t, u, len, wp);
/* log(sin) is unstable with large imaginary parts;
cot_pi is implemented in a numerically stable way */
acb_set(u, h);
acb_one(u + 1);
_acb_poly_cot_pi_series(u, u, 2, len - 1, wp);
_acb_poly_integral(u, u, len, wp);
acb_const_pi(u, wp);
_acb_vec_scalar_mul(u + 1, u + 1, len - 1, u, wp);
acb_log_sin_pi(u, h, wp);
_acb_vec_sub(u, t, u, len, wp);
acb_const_pi(t, wp); /* todo: constant for log pi */
acb_log(t, t, wp);
acb_add(u, u, t, wp);
}
else
{
/* log gamma(x) = log gamma(x+r) - log rf(x,r) */
acb_add_ui(zr, h, r, wp);
_acb_poly_gamma_stirling_eval(u, zr, n, len, wp);
if (r != 0)
{
_log_rising_ui_series(t, h, r, len, wp);
_acb_vec_sub(u, u, t, len, wp);
}
}
/* compose with nonconstant part */
acb_zero(t);
_acb_vec_set(t + 1, h + 1, hlen - 1);
_acb_poly_compose_series(res, u, len, t, hlen, len, prec);
acb_clear(zr);
_acb_vec_clear(t, len);
_acb_vec_clear(u, len);
}
void acb_hypgeom_u_asymp(acb_t res, const acb_t a, const acb_t b,
const acb_t z, slong n, slong prec)
{
acb_struct aa[3];
acb_t s, t, w, winv;
int R, p, q, is_real, is_terminating;
slong n_terminating;
if (!acb_is_finite(a) || !acb_is_finite(b) || !acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
acb_init(aa);
acb_init(aa + 1);
acb_init(aa + 2);
acb_init(s);
acb_init(t);
acb_init(w);
acb_init(winv);
is_terminating = 0;
n_terminating = WORD_MAX;
/* special case, for incomplete gamma
[todo: also when they happen to be exact and with difference 1...] */
if (a == b)
{
acb_set(aa, a);
p = 1;
q = 0;
}
else
{
acb_set(aa, a);
acb_sub(aa + 1, a, b, prec);
acb_add_ui(aa + 1, aa + 1, 1, prec);
acb_one(aa + 2);
p = 2;
q = 1;
}
if (acb_is_nonpositive_int(aa))
{
is_terminating = 1;
if (arf_cmpabs_ui(arb_midref(acb_realref(aa)), prec) < 0)
n_terminating = 1 - arf_get_si(arb_midref(acb_realref(aa)), ARF_RND_DOWN);
}
if (p == 2 && acb_is_nonpositive_int(aa + 1))
{
is_terminating = 1;
if (arf_cmpabs_ui(arb_midref(acb_realref(aa + 1)), n_terminating) < 0)
n_terminating = 1 - arf_get_si(arb_midref(acb_realref(aa + 1)), ARF_RND_DOWN);
}
acb_neg(w, z);
acb_inv(w, w, prec);
acb_neg(winv, z);
/* low degree polynomial -- no need to try to terminate sooner */
if (is_terminating && n_terminating < 8)
{
acb_hypgeom_pfq_sum_invz(s, t, aa, p, aa + p, q, w, winv,
n_terminating, prec);
acb_set(res, s);
}
else
{
mag_t C1, Cn, alpha, nu, sigma, rho, zinv, tmp, err;
mag_init(C1);
mag_init(Cn);
mag_init(alpha);
mag_init(nu);
mag_init(sigma);
mag_init(rho);
mag_init(zinv);
mag_init(tmp);
mag_init(err);
acb_hypgeom_u_asymp_bound_factors(&R, alpha, nu,
sigma, rho, zinv, a, b, z);
is_real = acb_is_real(a) && acb_is_real(b) && acb_is_real(z) &&
(is_terminating || arb_is_positive(acb_realref(z)));
if (R == 0)
{
/* if R == 0, the error bound is infinite unless terminating */
if (is_terminating && n_terminating < prec)
{
acb_hypgeom_pfq_sum_invz(s, t, aa, p, aa + p, q, w, winv,
n_terminating, prec);
acb_set(res, s);
}
else
{
acb_indeterminate(res);
}
}
else
{
/* C1 */
acb_hypgeom_mag_Cn(C1, R, nu, sigma, 1);
/* err = 2 * alpha * exp(...) */
mag_mul(tmp, C1, rho);
mag_mul(tmp, tmp, alpha);
mag_mul(tmp, tmp, zinv);
mag_mul_2exp_si(tmp, tmp, 1);
mag_exp(err, tmp);
mag_mul(err, err, alpha);
mag_mul_2exp_si(err, err, 1);
/* choose n automatically */
if (n < 0)
{
slong moreprec;
/* take err into account when finding truncation point */
/* we should take Cn into account as well, but this depends
on n which is to be determined; it's easier to look
only at exp(...) which should be larger anyway */
if (mag_cmp_2exp_si(err, 10 * prec) > 0)
moreprec = 10 * prec;
else if (mag_cmp_2exp_si(err, 0) < 0)
moreprec = 0;
else
moreprec = MAG_EXP(err);
n = acb_hypgeom_pfq_choose_n_max(aa, p, aa + p, q, w,
prec + moreprec, FLINT_MIN(WORD_MAX / 2, 50 + 10.0 * prec));
}
acb_hypgeom_pfq_sum_invz(s, t, aa, p, aa + p, q, w, winv, n, prec);
/* add error bound, if not terminating */
if (!(is_terminating && n == n_terminating))
{
acb_hypgeom_mag_Cn(Cn, R, nu, sigma, n);
mag_mul(err, err, Cn);
/* nth term * factor */
acb_get_mag(tmp, t);
mag_mul(err, err, tmp);
if (is_real)
arb_add_error_mag(acb_realref(s), err);
else
acb_add_error_mag(s, err);
}
acb_set(res, s);
}
mag_clear(C1);
mag_clear(Cn);
mag_clear(alpha);
mag_clear(nu);
mag_clear(sigma);
mag_clear(rho);
mag_clear(zinv);
mag_clear(tmp);
mag_clear(err);
}
acb_clear(aa);
acb_clear(aa + 1);
acb_clear(aa + 2);
acb_clear(s);
acb_clear(t);
acb_clear(w);
acb_clear(winv);
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("laguerre_l....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 2000 * arb_test_multiplier(); iter++)
{
acb_t n, m, n1, m1, z, res1, res2, res3, s;
slong prec;
acb_init(n);
acb_init(m);
acb_init(n1);
acb_init(m1);
acb_init(z);
acb_init(res1);
acb_init(res2);
acb_init(res3);
acb_init(s);
prec = 2 + n_randint(state, 200);
if (n_randint(state, 2))
{
acb_set_si(n, n_randint(state, 20) - 10);
acb_set_si(m, n_randint(state, 20) - 10);
}
else
{
acb_randtest_param(n, state, 1 + n_randint(state, 400), 10);
acb_randtest_param(m, state, 1 + n_randint(state, 400), 10);
}
acb_randtest_param(z, state, 1 + n_randint(state, 400), 10);
acb_sub_ui(n1, n, 1, prec);
acb_sub_ui(m1, m, 1, prec);
acb_hypgeom_laguerre_l(res1, n, m, z, prec);
acb_hypgeom_laguerre_l(res2, n1, m, z, 2 + n_randint(state, 200));
acb_hypgeom_laguerre_l(res3, n, m1, z, 2 + n_randint(state, 200));
acb_add(s, res2, res3, prec);
if (acb_is_finite(res1) && acb_is_finite(s) && !acb_overlaps(res1, s))
{
flint_printf("FAIL: consistency\n\n");
flint_printf("iter = %wd\n\n", iter);
flint_printf("n = "); acb_printd(n, 30); flint_printf("\n\n");
flint_printf("m = "); acb_printd(m, 30); flint_printf("\n\n");
flint_printf("z = "); acb_printd(z, 30); flint_printf("\n\n");
flint_printf("res1 = "); acb_printd(res1, 30); flint_printf("\n\n");
flint_printf("res2 = "); acb_printd(res2, 30); flint_printf("\n\n");
flint_printf("res3 = "); acb_printd(res3, 30); flint_printf("\n\n");
flint_printf("s = "); acb_printd(s, 30); flint_printf("\n\n");
abort();
}
acb_clear(n);
acb_clear(m);
acb_clear(n1);
acb_clear(m1);
acb_clear(z);
acb_clear(res1);
acb_clear(res2);
acb_clear(res3);
acb_clear(s);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
void
acb_hypgeom_erf(acb_t res, const acb_t z, slong prec)
{
double x, y, abs_z2, log_z, log_erf_z_asymp;
slong prec2, wp;
int more_imaginary;
if (!acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
if (acb_is_zero(z))
{
acb_zero(res);
return;
}
if ((arf_cmpabs_2exp_si(arb_midref(acb_realref(z)), -64) < 0 &&
arf_cmpabs_2exp_si(arb_midref(acb_imagref(z)), -64) < 0))
{
acb_hypgeom_erf_1f1(res, z, prec, prec, 1);
return;
}
if ((arf_cmpabs_2exp_si(arb_midref(acb_realref(z)), 64) > 0 ||
arf_cmpabs_2exp_si(arb_midref(acb_imagref(z)), 64) > 0))
{
acb_hypgeom_erf_asymp(res, z, 0, prec, prec);
return;
}
x = arf_get_d(arb_midref(acb_realref(z)), ARF_RND_DOWN);
y = arf_get_d(arb_midref(acb_imagref(z)), ARF_RND_DOWN);
abs_z2 = x * x + y * y;
log_z = 0.5 * log(abs_z2);
/* estimate of log(erf(z)), disregarding csgn term */
log_erf_z_asymp = y*y - x*x - log_z;
if (log_z - abs_z2 < -(prec + 8) * 0.69314718055994530942)
{
/* If the asymptotic term is small, we can
compute with reduced precision. */
prec2 = FLINT_MIN(prec + 4 + log_erf_z_asymp * 1.4426950408889634074, (double) prec);
prec2 = FLINT_MAX(8, prec2);
prec2 = FLINT_MIN(prec2, prec);
acb_hypgeom_erf_asymp(res, z, 0, prec, prec2);
}
else
{
more_imaginary = arf_cmpabs(arb_midref(acb_imagref(z)),
arb_midref(acb_realref(z))) > 0;
/* Worst case: exp(|x|^2), computed: exp(x^2).
(x^2+y^2) - (x^2-y^2) = 2y^2, etc. */
if (more_imaginary)
wp = prec + FLINT_MAX(2 * x * x, 0.0) * 1.4426950408889634074 + 5;
else
wp = prec + FLINT_MAX(2 * y * y, 0.0) * 1.4426950408889634074 + 5;
acb_hypgeom_erf_1f1(res, z, prec, wp, more_imaginary);
}
}
void
acb_inv(acb_t res, const acb_t z, slong prec)
{
mag_t am, bm;
slong hprec;
#define a arb_midref(acb_realref(z))
#define b arb_midref(acb_imagref(z))
#define x arb_radref(acb_realref(z))
#define y arb_radref(acb_imagref(z))
/* choose precision for the floating-point approximation of a^2+b^2 so
that the double rounding result in less than
2 ulp error; also use at least MAG_BITS bits since the
value will be recycled for error bounds */
hprec = FLINT_MAX(prec + 3, MAG_BITS);
if (arb_is_zero(acb_imagref(z)))
{
arb_inv(acb_realref(res), acb_realref(z), prec);
arb_zero(acb_imagref(res));
return;
}
if (arb_is_zero(acb_realref(z)))
{
arb_inv(acb_imagref(res), acb_imagref(z), prec);
arb_neg(acb_imagref(res), acb_imagref(res));
arb_zero(acb_realref(res));
return;
}
if (!acb_is_finite(z))
{
acb_indeterminate(res);
return;
}
if (mag_is_zero(x) && mag_is_zero(y))
{
int inexact;
arf_t a2b2;
arf_init(a2b2);
inexact = arf_sosq(a2b2, a, b, hprec, ARF_RND_DOWN);
if (arf_is_special(a2b2))
{
acb_indeterminate(res);
}
else
{
_arb_arf_div_rounded_den(acb_realref(res), a, a2b2, inexact, prec);
_arb_arf_div_rounded_den(acb_imagref(res), b, a2b2, inexact, prec);
arf_neg(arb_midref(acb_imagref(res)), arb_midref(acb_imagref(res)));
}
arf_clear(a2b2);
return;
}
mag_init(am);
mag_init(bm);
/* first bound |a|-x, |b|-y */
arb_get_mag_lower(am, acb_realref(z));
arb_get_mag_lower(bm, acb_imagref(z));
if ((mag_is_zero(am) && mag_is_zero(bm)))
{
acb_indeterminate(res);
}
else
{
/*
The propagated error in the real part is given exactly by
(a+x')/((a+x')^2+(b+y'))^2 - a/(a^2+b^2) = P / Q,
P = [(b^2-a^2) x' - a (x'^2+y'^2 + 2y'b)]
Q = [(a^2+b^2)((a+x')^2+(b+y')^2)]
where |x'| <= x and |y'| <= y, and analogously for the imaginary part.
*/
mag_t t, u, v, w;
arf_t a2b2;
int inexact;
mag_init(t);
mag_init(u);
mag_init(v);
mag_init(w);
arf_init(a2b2);
inexact = arf_sosq(a2b2, a, b, hprec, ARF_RND_DOWN);
/* compute denominator */
/* t = (|a|-x)^2 + (|b|-x)^2 (lower bound) */
mag_mul_lower(t, am, am);
mag_mul_lower(u, bm, bm);
mag_add_lower(t, t, u);
/* u = a^2 + b^2 (lower bound) */
arf_get_mag_lower(u, a2b2);
/* t = ((|a|-x)^2 + (|b|-x)^2)(a^2 + b^2) (lower bound) */
mag_mul_lower(t, t, u);
/* compute numerator */
/* real: |a^2-b^2| x + |a| ((x^2 + y^2) + 2 |b| y)) */
/* imag: |a^2-b^2| y + |b| ((x^2 + y^2) + 2 |a| x)) */
/* am, bm = upper bounds for a, b */
arf_get_mag(am, a);
arf_get_mag(bm, b);
/* v = x^2 + y^2 */
mag_mul(v, x, x);
mag_addmul(v, y, y);
/* u = |a| ((x^2 + y^2) + 2 |b| y) */
mag_mul_2exp_si(u, bm, 1);
mag_mul(u, u, y);
mag_add(u, u, v);
mag_mul(u, u, am);
/* v = |b| ((x^2 + y^2) + 2 |a| x) */
mag_mul_2exp_si(w, am, 1);
mag_addmul(v, w, x);
mag_mul(v, v, bm);
/* w = |b^2 - a^2| (upper bound) */
if (arf_cmpabs(a, b) >= 0)
mag_mul(w, am, am);
else
mag_mul(w, bm, bm);
mag_addmul(u, w, x);
mag_addmul(v, w, y);
mag_div(arb_radref(acb_realref(res)), u, t);
mag_div(arb_radref(acb_imagref(res)), v, t);
_arb_arf_div_rounded_den_add_err(acb_realref(res), a, a2b2, inexact, prec);
_arb_arf_div_rounded_den_add_err(acb_imagref(res), b, a2b2, inexact, prec);
arf_neg(arb_midref(acb_imagref(res)), arb_midref(acb_imagref(res)));
mag_clear(t);
mag_clear(u);
mag_clear(v);
mag_clear(w);
arf_clear(a2b2);
}
mag_clear(am);
mag_clear(bm);
#undef a
#undef b
#undef x
#undef y
}
void
acb_hypgeom_airy(acb_t ai, acb_t aip, acb_t bi, acb_t bip, const acb_t z, slong prec)
{
arf_srcptr re, im;
double x, y, t, zmag, z15, term_est, airy_est, abstol;
slong n, wp;
if (!acb_is_finite(z))
{
if (ai != NULL) acb_indeterminate(ai);
if (aip != NULL) acb_indeterminate(aip);
if (bi != NULL) acb_indeterminate(bi);
if (bip != NULL) acb_indeterminate(bip);
return;
}
re = arb_midref(acb_realref(z));
im = arb_midref(acb_imagref(z));
wp = prec * 1.03 + 15;
/* tiny input -- use direct method and pick n without underflowing */
if (arf_cmpabs_2exp_si(re, -64) < 0 && arf_cmpabs_2exp_si(im, -64) < 0)
{
if (arf_cmpabs_2exp_si(re, -wp) < 0 && arf_cmpabs_2exp_si(im, -wp) < 0)
{
n = 1; /* very tiny input */
}
else
{
if (arf_cmpabs(re, im) > 0)
zmag = fmpz_get_d(ARF_EXPREF(re));
else
zmag = fmpz_get_d(ARF_EXPREF(im));
zmag = (zmag + 1) * (1.0 / LOG2);
n = wp / (-zmag) + 1;
}
acb_hypgeom_airy_direct(ai, aip, bi, bip, z, n, wp);
} /* huge input -- use asymptotics and pick n without overflowing */
else if ((arf_cmpabs_2exp_si(re, 64) > 0 || arf_cmpabs_2exp_si(im, 64) > 0))
{
if (arf_cmpabs_2exp_si(re, prec) > 0 || arf_cmpabs_2exp_si(im, prec) > 0)
{
n = 1; /* very huge input */
}
else
{
x = fmpz_get_d(ARF_EXPREF(re));
y = fmpz_get_d(ARF_EXPREF(im));
zmag = (FLINT_MAX(x, y) - 2) * (1.0 / LOG2);
n = asymp_pick_terms(wp, zmag);
n = FLINT_MAX(n, 1);
}
acb_hypgeom_airy_asymp(ai, aip, bi, bip, z, n, wp);
}
else /* moderate input */
{
x = arf_get_d(re, ARF_RND_DOWN);
y = arf_get_d(im, ARF_RND_DOWN);
zmag = sqrt(x * x + y * y);
z15 = zmag * sqrt(zmag);
if (zmag >= 4.0 && (n = asymp_pick_terms(wp, log(zmag))) != -1)
{
acb_hypgeom_airy_asymp(ai, aip, bi, bip, z, n, wp);
}
else if (zmag <= 1.5)
{
t = 3 * (wp * LOG2) / (2 * z15 * EXP1);
t = (wp * LOG2) / (2 * d_lambertw(t));
n = FLINT_MAX(t + 1, 2);
acb_hypgeom_airy_direct(ai, aip, bi, bip, z, n, wp);
}
else
{
/* estimate largest term: log2(exp(2(z^3/9)^(1/2))) */
term_est = 0.96179669392597560491 * z15;
/* estimate the smaller of Ai and Bi */
airy_est = estimate_airy(x, y, (ai != NULL || aip != NULL));
/* estimate absolute tolerance and necessary working precision */
abstol = airy_est - wp;
wp = wp + term_est - airy_est;
wp = FLINT_MAX(wp, 10);
t = 3 * (-abstol * LOG2) / (2 * z15 * EXP1);
t = (-abstol * LOG2) / (2 * d_lambertw(t));
n = FLINT_MAX(t + 1, 2);
if (acb_is_exact(z))
acb_hypgeom_airy_direct(ai, aip, bi, bip, z, n, wp);
else
acb_hypgeom_airy_direct_prop(ai, aip, bi, bip, z, n, wp);
}
}
if (ai != NULL) acb_set_round(ai, ai, prec);
if (aip != NULL) acb_set_round(aip, aip, prec);
if (bi != NULL) acb_set_round(bi, bi, prec);
if (bip != NULL) acb_set_round(bip, bip, prec);
}
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;
}
