void acb_lambertw_left(acb_t res, const acb_t z, const fmpz_t k, slong prec) { if (acb_contains_zero(z) && !(fmpz_equal_si(k, -1) && acb_is_real(z))) { acb_indeterminate(res); return; } if (arb_is_positive(acb_imagref(z))) { acb_lambertw(res, z, k, 0, prec); } else if (arb_is_nonpositive(acb_imagref(z))) { fmpz_t kk; fmpz_init(kk); fmpz_add_ui(kk, k, 1); fmpz_neg(kk, kk); acb_conj(res, z); acb_lambertw(res, res, kk, 0, prec); acb_conj(res, res); fmpz_clear(kk); } else { acb_t za, zb; fmpz_t kk; acb_init(za); acb_init(zb); fmpz_init(kk); acb_set(za, z); acb_conj(zb, z); arb_nonnegative_part(acb_imagref(za), acb_imagref(za)); arb_nonnegative_part(acb_imagref(zb), acb_imagref(zb)); fmpz_add_ui(kk, k, 1); fmpz_neg(kk, kk); acb_lambertw(za, za, k, 0, prec); acb_lambertw(zb, zb, kk, 0, prec); acb_conj(zb, zb); acb_union(res, za, zb, prec); acb_clear(za); acb_clear(zb); fmpz_clear(kk); } }
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); }
void acb_hypgeom_m_1f1(acb_t res, const acb_t a, const acb_t b, const acb_t z, int regularized, slong prec) { if (arf_sgn(arb_midref(acb_realref(z))) >= 0 || (acb_is_int(a) && arb_is_nonpositive(acb_realref(a)))) { _acb_hypgeom_m_1f1(res, a, b, z, regularized, prec, prec, 0); } else { _acb_hypgeom_m_1f1(res, a, b, z, regularized, prec, prec, 1); } }
static void bound_K(arb_t C, const arb_t AN, const arb_t B, const arb_t T, slong wp) { if (arb_is_zero(B) || arb_is_zero(T)) { arb_one(C); } else { arb_div(C, B, AN, wp); /* TODO: atan is dumb, should also bound by pi/2 */ arb_atan(C, C, wp); arb_mul(C, C, T, wp); if (arb_is_nonpositive(C)) arb_one(C); else arb_exp(C, C, wp); } }
int acb_modular_is_in_fundamental_domain(const acb_t z, const arf_t tol, long prec) { arb_t t; arb_init(t); /* require re(w) + 1/2 >= 0 */ arb_set_ui(t, 1); arb_mul_2exp_si(t, t, -1); arb_add(t, t, acb_realref(z), prec); arb_add_arf(t, t, tol, prec); if (!arb_is_nonnegative(t)) { arb_clear(t); return 0; } /* require re(w) - 1/2 <= 0 */ arb_set_ui(t, 1); arb_mul_2exp_si(t, t, -1); arb_sub(t, acb_realref(z), t, prec); arb_sub_arf(t, t, tol, prec); if (!arb_is_nonpositive(t)) { arb_clear(t); return 0; } /* require |w| >= 1 - tol, i.e. |w| - 1 + tol >= 0 */ acb_abs(t, z, prec); arb_sub_ui(t, t, 1, prec); arb_add_arf(t, t, tol, prec); if (!arb_is_nonnegative(t)) { arb_clear(t); return 0; } arb_clear(t); return 1; }
void acb_hypgeom_m_1f1(acb_t res, const acb_t a, const acb_t b, const acb_t z, int regularized, long prec) { acb_t t; if (regularized) { acb_init(t); acb_rgamma(t, b, prec); } if (arf_sgn(arb_midref(acb_realref(z))) >= 0 || (acb_is_int(a) && arb_is_nonpositive(acb_realref(a)))) { _acb_hypgeom_m_1f1(res, a, b, z, prec); } else { /* Kummer's transformation */ acb_t u, v; acb_init(u); acb_init(v); acb_sub(u, b, a, prec); acb_neg(v, z); _acb_hypgeom_m_1f1(u, u, b, v, prec); acb_exp(v, z, prec); acb_mul(res, u, v, prec); acb_clear(u); acb_clear(v); } if (regularized) { acb_mul(res, res, t, prec); acb_clear(t); } }
void acb_hypgeom_ci_asymp(acb_t res, const acb_t z, slong prec) { acb_t t, u, w, v, one; acb_init(t); acb_init(u); acb_init(w); acb_init(v); acb_init(one); acb_one(one); acb_mul_onei(w, z); /* u = U(1,1,iz) */ acb_hypgeom_u_asymp(u, one, one, w, -1, prec); /* v = e^(-iz) */ acb_neg(v, w); acb_exp(v, v, prec); acb_mul(t, u, v, prec); if (acb_is_real(z)) { arb_div(acb_realref(t), acb_imagref(t), acb_realref(z), prec); arb_zero(acb_imagref(t)); acb_neg(t, t); } else { /* u = U(1,1,-iz) */ acb_neg(w, w); acb_hypgeom_u_asymp(u, one, one, w, -1, prec); acb_inv(v, v, prec); acb_submul(t, u, v, prec); acb_div(t, t, w, prec); acb_mul_2exp_si(t, t, -1); } if (arb_is_zero(acb_realref(z))) { if (arb_is_positive(acb_imagref(z))) { arb_const_pi(acb_imagref(t), prec); arb_mul_2exp_si(acb_imagref(t), acb_imagref(t), -1); } else if (arb_is_negative(acb_imagref(z))) { arb_const_pi(acb_imagref(t), prec); arb_mul_2exp_si(acb_imagref(t), acb_imagref(t), -1); arb_neg(acb_imagref(t), acb_imagref(t)); } else { acb_const_pi(u, prec); acb_mul_2exp_si(u, u, -1); arb_zero(acb_imagref(t)); arb_add_error(acb_imagref(t), acb_realref(u)); } } else { /* 0 if positive or positive imaginary pi if upper left quadrant (including negative real axis) -pi if lower left quadrant (including negative imaginary axis) */ if (arb_is_positive(acb_realref(z))) { /* do nothing */ } else if (arb_is_negative(acb_realref(z)) && arb_is_nonnegative(acb_imagref(z))) { acb_const_pi(u, prec); arb_add(acb_imagref(t), acb_imagref(t), acb_realref(u), prec); } else if (arb_is_nonpositive(acb_realref(z)) && arb_is_negative(acb_imagref(z))) { acb_const_pi(u, prec); arb_sub(acb_imagref(t), acb_imagref(t), acb_realref(u), prec); } else { /* add [-pi,pi] */ acb_const_pi(u, prec); arb_add_error(acb_imagref(t), acb_realref(u)); } } acb_swap(res, t); acb_clear(t); acb_clear(u); acb_clear(w); acb_clear(v); acb_clear(one); }
/* todo: use log(1-z) when this is better? would also need to adjust strategy in the main function */ void acb_hypgeom_dilog_bernoulli(acb_t res, const acb_t z, slong prec) { acb_t s, w, w2; slong n, k; fmpz_t c, d; mag_t m, err; double lm; int real; acb_init(s); acb_init(w); acb_init(w2); fmpz_init(c); fmpz_init(d); mag_init(m); mag_init(err); real = 0; if (acb_is_real(z)) { arb_sub_ui(acb_realref(w), acb_realref(z), 1, 30); real = arb_is_nonpositive(acb_realref(w)); } acb_log(w, z, prec); acb_get_mag(m, w); /* for k >= 4, the terms are bounded by (|w| / (2 pi))^k */ mag_set_ui_2exp_si(err, 2670177, -24); /* upper bound for 1/(2pi) */ mag_mul(err, err, m); lm = mag_get_d_log2_approx(err); if (lm < -0.25) { n = prec / (-lm) + 1; n = FLINT_MAX(n, 4); mag_geom_series(err, err, n); BERNOULLI_ENSURE_CACHED(n) acb_mul(w2, w, w, prec); for (k = n - (n % 2 == 0); k >= 3; k -= 2) { fmpz_mul_ui(c, fmpq_denref(bernoulli_cache + k - 1), k - 1); fmpz_mul_ui(d, c, (k + 1) * (k + 2)); acb_mul(s, s, w2, prec); acb_mul_fmpz(s, s, c, prec); fmpz_mul_ui(c, fmpq_numref(bernoulli_cache + k - 1), (k + 1) * (k + 2)); acb_sub_fmpz(s, s, c, prec); acb_div_fmpz(s, s, d, prec); } acb_mul(s, s, w, prec); acb_mul_2exp_si(s, s, 1); acb_sub_ui(s, s, 3, prec); acb_mul(s, s, w2, prec); acb_mul_2exp_si(s, s, -1); acb_const_pi(w2, prec); acb_addmul(s, w2, w2, prec); acb_div_ui(s, s, 6, prec); acb_neg(w2, w); acb_log(w2, w2, prec); acb_submul(s, w2, w, prec); acb_add(res, s, w, prec); acb_add_error_mag(res, err); if (real) arb_zero(acb_imagref(res)); } else { acb_indeterminate(res); } acb_clear(s); acb_clear(w); acb_clear(w2); fmpz_clear(c); fmpz_clear(d); mag_clear(m); mag_clear(err); }
void _acb_hypgeom_m_1f1(acb_t res, const acb_t a, const acb_t b, const acb_t z, int regularized, slong prec, slong gamma_prec, int kummer) { if (regularized) { /* Remove singularity */ if (acb_is_int(b) && arb_is_nonpositive(acb_realref(b)) && arf_cmpabs_2exp_si(arb_midref(acb_realref(b)), 30) < 0) { acb_t c, d, t, u; slong n; n = arf_get_si(arb_midref(acb_realref(b)), ARF_RND_DOWN); acb_init(c); acb_init(d); acb_init(t); acb_init(u); acb_sub(c, a, b, prec); acb_add_ui(c, c, 1, prec); acb_neg(d, b); acb_add_ui(d, d, 2, prec); _acb_hypgeom_m_1f1(t, c, d, z, 0, prec, gamma_prec, kummer); acb_pow_ui(u, z, 1 - n, prec); acb_mul(t, t, u, prec); acb_rising_ui(u, a, 1 - n, prec); acb_mul(t, t, u, prec); arb_fac_ui(acb_realref(u), 1 - n, prec); acb_div_arb(res, t, acb_realref(u), prec); acb_clear(c); acb_clear(d); acb_clear(t); acb_clear(u); } else { acb_t t; acb_init(t); acb_rgamma(t, b, gamma_prec); _acb_hypgeom_m_1f1(res, a, b, z, 0, prec, gamma_prec, kummer); acb_mul(res, res, t, prec); acb_clear(t); } return; } /* Kummer's transformation */ if (kummer) { acb_t u, v; acb_init(u); acb_init(v); acb_sub(u, b, a, prec); acb_neg(v, z); _acb_hypgeom_m_1f1(u, u, b, v, regularized, prec, gamma_prec, 0); acb_exp(v, z, prec); acb_mul(res, u, v, prec); acb_clear(u); acb_clear(v); return; } if (acb_is_one(a)) { acb_hypgeom_pfq_direct(res, NULL, 0, b, 1, z, -1, prec); } else { acb_struct c[3]; c[0] = *a; c[1] = *b; acb_init(c + 2); acb_one(c + 2); acb_hypgeom_pfq_direct(res, c, 1, c + 1, 2, z, -1, prec); acb_clear(c + 2); } }
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_sqrt(acb_t y, const acb_t x, slong prec) { arb_t r, t, u; slong wp; #define a acb_realref(x) #define b acb_imagref(x) #define c acb_realref(y) #define d acb_imagref(y) if (arb_is_zero(b)) { if (arb_is_nonnegative(a)) { arb_sqrt(c, a, prec); arb_zero(d); return; } else if (arb_is_nonpositive(a)) { arb_neg(d, a); arb_sqrt(d, d, prec); arb_zero(c); return; } } if (arb_is_zero(a)) { if (arb_is_nonnegative(b)) { arb_mul_2exp_si(c, b, -1); arb_sqrt(c, c, prec); arb_set(d, c); return; } else if (arb_is_nonpositive(b)) { arb_mul_2exp_si(c, b, -1); arb_neg(c, c); arb_sqrt(c, c, prec); arb_neg(d, c); return; } } wp = prec + 4; arb_init(r); arb_init(t); arb_init(u); acb_abs(r, x, wp); arb_add(t, r, a, wp); if (arb_rel_accuracy_bits(t) > 8) { /* sqrt(a+bi) = sqrt((r+a)/2) + b/sqrt(2*(r+a))*i, r = |a+bi| */ arb_mul_2exp_si(u, t, 1); arb_sqrt(u, u, wp); arb_div(d, b, u, prec); arb_set_round(c, u, prec); arb_mul_2exp_si(c, c, -1); } else { /* sqrt(a+bi) = sqrt((r+a)/2) + (b/|b|)*sqrt((r-a)/2)*i (sign) */ arb_mul_2exp_si(t, t, -1); arb_sub(u, r, a, wp); arb_mul_2exp_si(u, u, -1); arb_sqrtpos(c, t, prec); if (arb_is_nonnegative(b)) { arb_sqrtpos(d, u, prec); } else if (arb_is_nonpositive(b)) { arb_sqrtpos(d, u, prec); arb_neg(d, d); } else { arb_sqrtpos(t, u, wp); arb_neg(u, t); arb_union(d, t, u, prec); } } arb_clear(r); arb_clear(t); arb_clear(u); #undef a #undef b #undef c #undef d }
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; }
void acb_lambertw_middle(acb_t res, const acb_t z, slong prec) { fmpz_t k; if (acb_contains_zero(z)) { acb_indeterminate(res); return; } fmpz_init(k); fmpz_set_si(k, -1); if (arb_is_positive(acb_imagref(z))) { acb_lambertw(res, z, k, 0, prec); } else if (arb_is_negative(acb_imagref(z))) { acb_conj(res, z); acb_lambertw(res, res, k, 0, prec); acb_conj(res, res); } else if (arb_is_negative(acb_realref(z))) { if (arb_is_nonnegative(acb_imagref(z))) { acb_lambertw(res, z, k, 0, prec); } else if (arb_is_negative(acb_imagref(z))) { acb_conj(res, z); acb_lambertw(res, res, k, 0, prec); acb_conj(res, res); } else { acb_t za, zb; acb_init(za); acb_init(zb); acb_set(za, z); acb_conj(zb, z); arb_nonnegative_part(acb_imagref(za), acb_imagref(za)); arb_nonnegative_part(acb_imagref(zb), acb_imagref(zb)); acb_lambertw(za, za, k, 0, prec); acb_lambertw(zb, zb, k, 0, prec); acb_conj(zb, zb); acb_union(res, za, zb, prec); acb_clear(za); acb_clear(zb); } } else /* re is positive */ { if (arb_is_positive(acb_imagref(z))) { acb_lambertw(res, z, k, 0, prec); } else if (arb_is_nonpositive(acb_imagref(z))) { acb_conj(res, z); acb_lambertw(res, res, k, 0, prec); acb_conj(res, res); } else { acb_t za, zb; acb_init(za); acb_init(zb); acb_set(za, z); acb_conj(zb, z); arb_nonnegative_part(acb_imagref(za), acb_imagref(za)); arb_nonnegative_part(acb_imagref(zb), acb_imagref(zb)); acb_lambertw(za, za, k, 0, prec); acb_lambertw(zb, zb, k, 0, prec); acb_conj(zb, zb); acb_union(res, za, zb, prec); acb_clear(za); acb_clear(zb); } } fmpz_clear(k); }