void acb_hypgeom_beta_lower(acb_t res,
const acb_t a, const acb_t b, const acb_t z, int regularized, slong prec)
{
acb_t t, u;
if (acb_is_zero(z) && arb_is_positive(acb_realref(a)))
{
acb_zero(res);
return;
}
if (acb_is_one(z) && arb_is_positive(acb_realref(b)))
{
if (regularized)
acb_one(res);
else
acb_beta(res, a, b, prec);
return;
}
acb_init(t);
acb_init(u);
acb_sub_ui(t, b, 1, prec);
acb_neg(t, t);
acb_add_ui(u, a, 1, prec);
if (regularized)
{
acb_hypgeom_2f1(t, a, t, u, z, 1, prec);
acb_add(u, a, b, prec);
acb_gamma(u, u, prec);
acb_mul(t, t, u, prec);
acb_rgamma(u, b, prec);
acb_mul(t, t, u, prec);
}
else
{
acb_hypgeom_2f1(t, a, t, u, z, 0, prec);
acb_div(t, t, a, prec);
}
acb_pow(u, z, a, prec);
acb_mul(t, t, u, prec);
acb_set(res, t);
acb_clear(t);
acb_clear(u);
}
void
acb_hypgeom_jacobi_p(acb_t res, const acb_t n, const acb_t a, const acb_t b,
const acb_t z, slong prec)
{
acb_t t, u, v, w;
if (use_recurrence(n, a, b, prec))
{
acb_hypgeom_jacobi_p_ui_direct(res,
arf_get_si(arb_midref(acb_realref(n)), ARF_RND_DOWN), a, b, z, prec);
return;
}
acb_init(t);
acb_init(u);
acb_init(v);
acb_init(w);
acb_neg(t, n);
acb_add_ui(v, a, 1, prec);
acb_add(u, n, v, prec);
acb_add(u, u, b, prec);
acb_sub_ui(w, z, 1, prec);
acb_mul_2exp_si(w, w, -1);
acb_neg(w, w);
acb_hypgeom_2f1(w, t, u, v, w, 0, prec);
acb_rising(t, v, n, prec);
acb_mul(w, w, t, prec);
acb_add_ui(t, n, 1, prec);
acb_rgamma(t, t, prec);
acb_mul(w, w, t, prec);
acb_set(res, w);
acb_clear(t);
acb_clear(u);
acb_clear(v);
acb_clear(w);
}
void
arb_hypgeom_2f1(arb_t res, const arb_t a, const arb_t b, const arb_t c, const arb_t z, int regularized, 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), a);
arb_set(acb_realref(u), b);
arb_set(acb_realref(v), c);
arb_set(acb_realref(w), z);
acb_hypgeom_2f1(t, t, u, v, w, 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);
acb_clear(w);
}
int main(int argc, char *argv[])
{
int function, i, numtests;
slong prec, goal;
double t, total, logtotal;
acb_t a, b, c, z, r, s;
acb_init(a);
acb_init(b);
acb_init(c);
acb_init(z);
acb_init(r);
acb_init(s);
/* J(0,pi x) I(0,pi x) K(0,pi x) */
for (function = 0; function < 3; function++)
{
total = 0.0;
logtotal = 0.0;
if (function < 2)
numtests = 40;
else
numtests = 30;
for (i = 0; i < numtests; i++)
{
// printf("%2d ", i + 1); fflush(stdout);
TIMEIT_START
prec = 96;
for (;;)
{
if (function == 0)
{
acb_set_d_d(a, input_1f1[i][0], input_1f1[i][1]);
acb_set_d_d(b, input_1f1[i][2], input_1f1[i][3]);
acb_set_d_d(z, input_1f1[i][4], input_1f1[i][5]);
acb_hypgeom_m(r, a, b, z, 0, prec);
}
else if (function == 1)
{
acb_set_d_d(a, input_1f1[i][0], input_1f1[i][1]);
acb_set_d_d(b, input_1f1[i][2], input_1f1[i][3]);
acb_set_d_d(z, input_1f1[i][4], input_1f1[i][5]);
acb_hypgeom_u(r, a, b, z, prec);
}
else if (function == 2)
{
acb_set_d_d(a, input_2f1[i][0], input_2f1[i][1]);
acb_set_d_d(b, input_2f1[i][2], input_2f1[i][3]);
acb_set_d_d(c, input_2f1[i][4], input_2f1[i][5]);
acb_set_d_d(z, input_2f1[i][6], input_2f1[i][7]);
acb_hypgeom_2f1(r, a, b, c, z, 0, prec);
}
else
{
acb_set_d_d(a, input_2f1[i][0], input_2f1[i][1]);
acb_set_d_d(b, input_2f1[i][2], input_2f1[i][3]);
acb_set_d_d(c, input_2f1[i][4], input_2f1[i][5]);
acb_set_d_d(z, input_2f1[i][6], input_2f1[i][7]);
acb_mul_2exp_si(z, z, 1);
acb_sub_ui(z, z, 1, prec);
acb_neg(z, z);
acb_hypgeom_legendre_q(r, a, c, z, 0, prec);
}
if (function == 3)
{
if (acb_rel_accuracy_bits(r) >= goal)
break;
}
else
{
if (arb_can_round_arf(acb_realref(r), goal, ARF_RND_NEAR) &&
arb_can_round_arf(acb_imagref(r), goal, ARF_RND_NEAR))
break;
}
prec *= 2;
}
TIMEIT_STOP_VAL(t)
total += t;
logtotal += log(t);
#if 1
printf("%8g, ", t);
#else
printf("%8ld %8g ", prec, t);
_acb_print(r, 25);
printf("\n");
#endif
}
printf("---------------------------------------------------------------\n");
printf("Mean %g s; geometric mean %g\n", total, exp(logtotal / numtests));
printf("---------------------------------------------------------------\n");
}
acb_clear(a);
acb_clear(b);
acb_clear(c);
acb_clear(z);
acb_clear(r);
acb_clear(s);
}
void
acb_hypgeom_chebyshev_t(acb_t res, const acb_t n, const acb_t z, slong prec)
{
acb_t t;
if (acb_is_int(n) &&
arf_cmpabs_2exp_si(arb_midref(acb_realref(n)), FLINT_BITS - 1) < 0)
{
slong k = arf_get_si(arb_midref(acb_realref(n)), ARF_RND_DOWN);
acb_chebyshev_t_ui(res, FLINT_ABS(k), z, prec);
return;
}
if (acb_is_zero(z))
{
acb_mul_2exp_si(res, n, -1);
acb_cos_pi(res, res, prec);
return;
}
if (acb_is_one(z))
{
acb_one(res);
return;
}
acb_init(t);
acb_set_si(t, -1);
if (acb_equal(t, z))
{
acb_cos_pi(res, n, prec);
}
else
{
acb_sub_ui(t, z, 1, prec);
if (arf_cmpabs_2exp_si(arb_midref(acb_realref(t)), -2 - prec / 10) < 0 &&
arf_cmpabs_2exp_si(arb_midref(acb_imagref(t)), -2 - prec / 10) < 0)
{
acb_t a, c;
acb_init(a);
acb_init(c);
acb_neg(a, n);
acb_one(c);
acb_mul_2exp_si(c, c, -1);
acb_neg(t, t);
acb_mul_2exp_si(t, t, -1);
acb_hypgeom_2f1(res, a, n, c, t, 0, prec);
acb_clear(a);
acb_clear(c);
}
else if (arb_is_nonnegative(acb_realref(t)))
{
acb_acosh(t, z, prec);
acb_mul(t, t, n, prec);
acb_cosh(res, t, prec);
}
else
{
acb_acos(t, z, prec);
acb_mul(t, t, n, prec);
acb_cos(res, t, prec);
}
}
acb_clear(t);
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("2f1....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 3000; iter++)
{
acb_t a, b, c, z, w1, w2, t;
slong prec1, prec2;
int reg1, reg2, ebits;
int alg1, alg2;
acb_init(a);
acb_init(b);
acb_init(c);
acb_init(z);
acb_init(w1);
acb_init(w2);
acb_init(t);
prec1 = 2 + n_randint(state, 300);
prec2 = 2 + n_randint(state, 300);
if (n_randint(state, 20) == 0)
ebits = 30;
else
ebits = 5;
switch (n_randint(state, 3))
{
case 0:
acb_set_si(a, n_randint(state, 500));
acb_set_si(b, n_randint(state, 500));
acb_set_si(c, n_randint(state, 10));
break;
case 1:
acb_set_si(a, n_randint(state, 200) - 100);
acb_set_si(b, n_randint(state, 200) - 100);
acb_set_si(c, n_randint(state, 200) - 100);
break;
default:
acb_randtest_param(a, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
acb_randtest_param(b, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
acb_randtest_param(c, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
}
acb_randtest_param(z, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
acb_randtest(w1, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
acb_randtest(w2, state, 1 + n_randint(state, 400), 1 + n_randint(state, ebits));
reg1 = n_randint(state, 2);
reg2 = n_randint(state, 2);
alg1 = n_randint(state, 10);
alg2 = n_randint(state, 10);
switch (alg1)
{
case 0:
acb_hypgeom_2f1_direct(w1, a, b, c, z, reg1, prec1);
break;
case 1:
case 2:
case 3:
case 4:
case 5:
acb_hypgeom_2f1_transform(w1, a, b, c, z, reg1, alg1, prec1);
break;
case 6:
acb_hypgeom_2f1_corner(w1, a, b, c, z, reg1, prec1);
break;
default:
acb_hypgeom_2f1(w1, a, b, c, z, reg1, prec1);
}
switch (alg2)
{
case 0:
acb_hypgeom_2f1_direct(w2, a, b, c, z, reg2, prec2);
break;
case 1:
case 2:
case 3:
case 4:
case 5:
acb_hypgeom_2f1_transform(w2, a, b, c, z, reg2, alg2, prec2);
break;
case 6:
acb_hypgeom_2f1_corner(w2, a, b, c, z, reg2, prec2);
break;
default:
acb_hypgeom_2f1(w2, a, b, c, z, reg2, prec2);
}
if (reg1 != reg2)
{
acb_rgamma(t, c, prec2);
if (reg1)
acb_mul(w2, w2, t, prec2);
else
acb_mul(w1, w1, t, prec2);
}
if (!acb_overlaps(w1, w2))
{
flint_printf("FAIL: consistency\n\n");
flint_printf("iter = %wd, prec1 = %wd, prec2 = %wd\n\n", iter, prec1, prec2);
flint_printf("alg1 = %d, alg2 = %d\n\n", alg1, alg2);
flint_printf("reg1 = %d, reg2 = %d\n\n", reg1, reg2);
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("z = "); acb_printd(z, 30); flint_printf("\n\n");
flint_printf("w1 = "); acb_printd(w1, 30); flint_printf("\n\n");
flint_printf("w2 = "); acb_printd(w2, 30); flint_printf("\n\n");
abort();
}
acb_clear(a);
acb_clear(b);
acb_clear(c);
acb_clear(z);
acb_clear(w1);
acb_clear(w2);
acb_clear(t);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
long iter;
flint_rand_t state;
printf("chebyshev_t....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 2000; iter++)
{
acb_t n, z, a, b, c, t, res1, res2;
long prec;
acb_init(n);
acb_init(z);
acb_init(a);
acb_init(b);
acb_init(c);
acb_init(t);
acb_init(res1);
acb_init(res2);
prec = 2 + n_randint(state, 300);
acb_randtest_param(n, state, 1 + n_randint(state, 400), 1 + n_randint(state, 10));
acb_randtest_param(z, state, 1 + n_randint(state, 400), 1 + n_randint(state, 10));
acb_randtest_param(res1, state, 1 + n_randint(state, 400), 1 + n_randint(state, 10));
acb_randtest_param(res2, state, 1 + n_randint(state, 400), 1 + n_randint(state, 10));
acb_hypgeom_chebyshev_t(res1, n, z, prec);
acb_neg(a, n);
acb_set(b, n);
acb_one(c);
acb_mul_2exp_si(c, c, -1);
acb_sub_ui(t, z, 1, prec);
acb_neg(t, t);
acb_mul_2exp_si(t, t, -1);
acb_hypgeom_2f1(res2, a, b, c, t, 0, 2 + n_randint(state, 300));
if (!acb_overlaps(res1, res2))
{
printf("FAIL: consistency\n\n");
printf("iter = %ld\n\n", iter);
printf("n = ");
acb_printd(n, 30);
printf("\n\n");
printf("z = ");
acb_printd(z, 30);
printf("\n\n");
printf("res1 = ");
acb_printd(res1, 30);
printf("\n\n");
printf("res2 = ");
acb_printd(res2, 30);
printf("\n\n");
abort();
}
acb_clear(n);
acb_clear(z);
acb_clear(a);
acb_clear(b);
acb_clear(c);
acb_clear(t);
acb_clear(res1);
acb_clear(res2);
}
flint_randclear(state);
flint_cleanup();
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;
}
void
acb_hypgeom_legendre_q(acb_t res, const acb_t n, const acb_t m,
const acb_t z, int type, slong prec)
{
if (type == 0)
{
/* http://functions.wolfram.com/07.11.26.0033.01 */
/* todo: simplify the gamma quotients and the sqrt pi factor... */
acb_t a, b, c, z2, mn, nm, t, u;
acb_init(a);
acb_init(b);
acb_init(c);
acb_init(z2);
acb_init(mn);
acb_init(nm);
acb_init(t);
acb_init(u);
acb_add(mn, m, n, prec); /* mn = m + n */
acb_sub(nm, n, m, prec); /* nm = n - m */
acb_mul(z2, z, z, prec); /* z2 = z^2 */
/* t = 2F1((1-m-n)/2, (n-m)/2+1, 3/2, z^2) */
acb_sub_ui(a, mn, 1, prec);
acb_neg(a, a);
acb_mul_2exp_si(a, a, -1);
acb_mul_2exp_si(b, nm, -1);
acb_add_ui(b, b, 1, prec);
acb_set_ui(c, 3);
acb_mul_2exp_si(c, c, -1);
acb_hypgeom_2f1(t, a, b, c, z2, 0, prec);
/* u = 2F1(-(m+n)/2, (n-m+1)/2, 1/2, z^2) */
acb_neg(a, mn);
acb_mul_2exp_si(a, a, -1);
acb_add_ui(b, nm, 1, prec);
acb_mul_2exp_si(b, b, -1);
acb_one(c);
acb_mul_2exp_si(c, c, -1);
acb_hypgeom_2f1(u, a, b, c, z2, 0, prec);
/* a = cospi((m+n)/2) gamma((m+n)/2+1) rgamma((n-m+1)/2) z */
/* b = sinpi((m+n)/2) gamma((m+n+1)/2) rgamma((n-m)/2+1) / 2 */
acb_mul_2exp_si(a, mn, -1);
acb_sin_cos_pi(b, a, a, prec);
acb_mul_2exp_si(c, mn, -1);
acb_add_ui(c, c, 1, prec);
acb_gamma(c, c, prec);
acb_mul(a, a, c, prec);
acb_add_ui(c, nm, 1, prec);
acb_mul_2exp_si(c, c, -1);
acb_rgamma(c, c, prec);
acb_mul(a, a, c, prec);
acb_mul(a, a, z, prec);
acb_add_ui(c, mn, 1, prec);
acb_mul_2exp_si(c, c, -1);
acb_gamma(c, c, prec);
acb_mul(b, b, c, prec);
acb_mul_2exp_si(c, nm, -1);
acb_add_ui(c, c, 1, prec);
acb_rgamma(c, c, prec);
acb_mul(b, b, c, prec);
acb_mul_2exp_si(b, b, -1);
/* at - bu */
acb_mul(t, t, a, prec);
acb_mul(u, u, b, prec);
acb_sub(t, t, u, prec);
/* prefactor sqrt(pi) 2^m (1-z^2)^(-m/2) */
if (!acb_is_zero(m))
{
acb_sub_ui(u, z2, 1, prec);
acb_neg(u, u);
acb_neg(c, m);
acb_mul_2exp_si(c, c, -1);
acb_pow(u, u, c, prec);
acb_set_ui(c, 2);
acb_pow(c, c, m, prec);
acb_mul(u, u, c, prec);
acb_mul(t, t, u, prec);
}
arb_const_sqrt_pi(acb_realref(u), prec);
acb_mul_arb(t, t, acb_realref(u), prec);
acb_set(res, t);
acb_clear(a);
acb_clear(b);
acb_clear(c);
acb_clear(z2);
acb_clear(mn);
acb_clear(nm);
acb_clear(t);
acb_clear(u);
}
else if (type == 1)
{
if ((arf_cmpabs_2exp_si(arb_midref(acb_realref(z)), -2) < 0 &&
arf_cmpabs_2exp_si(arb_midref(acb_imagref(z)), -2) < 0) ||
!_acb_hypgeom_legendre_q_single_valid(z))
{
_acb_hypgeom_legendre_q_double(res, n, m, z, prec);
}
else
{
_acb_hypgeom_legendre_q_single(res, n, m, z, prec);
}
}
else
{
flint_printf("unsupported 'type' %d for legendre q\n", type);
abort();
}
}
void
_acb_hypgeom_legendre_q_single(acb_t res, const acb_t n, const acb_t m,
const acb_t z, slong prec)
{
acb_t a, b, c, z2, t, u;
acb_init(a);
acb_init(b);
acb_init(c);
acb_init(z2);
acb_init(t);
acb_init(u);
/* invalid in (-1,0) */
if (!_acb_hypgeom_legendre_q_single_valid(z))
{
acb_indeterminate(res);
return;
}
acb_pow_si(z2, z, -2, prec); /* z2 = 1/z^2 */
/* t = 2F1r((m+n+1)/2, (m+n)/2+1, n+3/2, 1/z^2) */
acb_add(b, m, n, prec);
acb_add_ui(a, b, 1, prec);
acb_mul_2exp_si(a, a, -1);
acb_mul_2exp_si(b, b, -1);
acb_add_ui(b, b, 1, prec);
acb_set_ui(c, 3);
acb_mul_2exp_si(c, c, -1);
acb_add(c, c, n, prec);
acb_hypgeom_2f1(t, a, b, c, z2, 1, prec);
/* prefactor sqrt(pi) 2^-n (z+1)^(m/2) (z-1)^(m/2) exp(i pi m) */
/* (1/2) gamma(m+n+1) z^(-m-n-1) */
if (!acb_is_zero(m))
{
acb_add_ui(z2, z, 1, prec);
acb_mul_2exp_si(c, m, -1);
acb_pow(z2, z2, c, prec);
acb_mul(t, t, z2, prec);
acb_sub_ui(z2, z, 1, prec);
acb_mul_2exp_si(c, m, -1);
acb_pow(z2, z2, c, prec);
acb_mul(t, t, z2, prec);
acb_exp_pi_i(z2, m, prec);
acb_mul(t, t, z2, prec);
}
acb_set_ui(z2, 2);
acb_neg(c, n);
acb_pow(z2, z2, c, prec);
acb_mul(t, t, z2, prec);
acb_add(c, m, n, prec);
acb_add_ui(c, c, 1, prec);
acb_gamma(z2, c, prec);
acb_mul(t, t, z2, prec);
acb_neg(c, c);
acb_pow(z2, z, c, prec);
acb_mul(t, t, z2, prec);
acb_mul_2exp_si(t, t, -1);
arb_const_sqrt_pi(acb_realref(u), prec);
acb_mul_arb(t, t, acb_realref(u), prec);
acb_set(res, t);
acb_clear(a);
acb_clear(b);
acb_clear(c);
acb_clear(z2);
acb_clear(t);
acb_clear(u);
}
