void
acb_hypgeom_expint(acb_t res, const acb_t s, const acb_t z, slong prec)
{
acb_t t;
acb_init(t);
acb_sub_ui(t, s, 1, prec);
acb_neg(t, t);
acb_hypgeom_gamma_upper(res, t, z, 2, prec);
acb_clear(t);
}
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);
}
int main()
{
long iter;
flint_rand_t state;
printf("gamma_upper....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 2000; iter++)
{
acb_t a0, a1, b, z, w0, w1, t, u;
long prec0, prec1;
int modified;
acb_init(a0);
acb_init(a1);
acb_init(b);
acb_init(z);
acb_init(w0);
acb_init(w1);
acb_init(t);
acb_init(u);
modified = n_randint(state, 2);
prec0 = 2 + n_randint(state, 1000);
prec1 = 2 + n_randint(state, 1000);
acb_randtest_maybe_half_int(a0, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_randtest(z, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_randtest(w0, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_randtest(w1, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_add_ui(a1, a0, 1, prec0);
switch (n_randint(state, 4))
{
case 0:
acb_hypgeom_gamma_upper_asymp(w0, a0, z, modified, prec0);
break;
case 1:
acb_hypgeom_gamma_upper_1f1a(w0, a0, z, modified, prec0);
break;
case 2:
acb_hypgeom_gamma_upper_1f1b(w0, a0, z, modified, prec0);
break;
default:
acb_hypgeom_gamma_upper(w0, a0, z, modified, prec0);
}
switch (n_randint(state, 4))
{
case 0:
acb_hypgeom_gamma_upper_asymp(w1, a0, z, modified, prec1);
break;
case 1:
acb_hypgeom_gamma_upper_1f1a(w1, a0, z, modified, prec1);
break;
case 2:
acb_hypgeom_gamma_upper_1f1b(w1, a0, z, modified, prec1);
break;
default:
acb_hypgeom_gamma_upper(w1, a0, z, modified, prec1);
}
if (!acb_overlaps(w0, w1))
{
printf("FAIL: consistency\n\n");
printf("nu = "); acb_printd(a0, 30); printf("\n\n");
printf("z = "); acb_printd(z, 30); printf("\n\n");
printf("w0 = "); acb_printd(w0, 30); printf("\n\n");
printf("w1 = "); acb_printd(w1, 30); printf("\n\n");
abort();
}
switch (n_randint(state, 4))
{
case 0:
acb_hypgeom_gamma_upper_asymp(w1, a1, z, modified, prec1);
break;
case 1:
acb_hypgeom_gamma_upper_1f1a(w1, a1, z, modified, prec1);
break;
case 2:
acb_hypgeom_gamma_upper_1f1b(w1, a1, z, modified, prec1);
break;
default:
acb_hypgeom_gamma_upper(w1, a1, z, modified, prec1);
}
/* a Gamma(a,z) + exp(-z) z^a = Gamma(a+1,z) */
if (modified)
acb_one(t);
else
acb_pow(t, z, a0, prec0);
acb_neg(u, z);
acb_exp(u, u, prec0);
acb_mul(t, t, u, prec0);
if (modified)
{
acb_mul(b, w1, z, prec0);
acb_addmul(t, a0, w0, prec0);
acb_sub(t, t, b, prec0);
}
else
{
acb_addmul(t, a0, w0, prec0);
acb_sub(t, t, w1, prec0);
}
if (!acb_contains_zero(t))
{
printf("FAIL: contiguous relation\n\n");
printf("nu = "); acb_printd(a0, 30); printf("\n\n");
printf("z = "); acb_printd(z, 30); printf("\n\n");
printf("w0 = "); acb_printd(w0, 30); printf("\n\n");
printf("w1 = "); acb_printd(w1, 30); printf("\n\n");
printf("t = "); acb_printd(t, 30); printf("\n\n");
abort();
}
acb_clear(a0);
acb_clear(a1);
acb_clear(b);
acb_clear(z);
acb_clear(w0);
acb_clear(w1);
acb_clear(t);
acb_clear(u);
}
flint_randclear(state);
flint_cleanup();
printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("gamma_lower....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 2000 * arb_test_multiplier(); iter++)
{
acb_t a0, a1, b, z, w0, w1, t, u, enz;
slong prec0, prec1;
int regularized;
acb_init(a0);
acb_init(a1);
acb_init(b);
acb_init(z);
acb_init(w0);
acb_init(w1);
acb_init(t);
acb_init(u);
acb_init(enz);
regularized = n_randint(state, 3);
prec0 = 2 + n_randint(state, 1000);
prec1 = 2 + n_randint(state, 1000);
acb_randtest_param(a0, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_randtest(z, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_randtest(w0, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_randtest(w1, state, 1 + n_randint(state, 1000), 1 + n_randint(state, 100));
acb_add_ui(a1, a0, 1, prec0);
acb_hypgeom_gamma_lower(w0, a0, z, regularized, prec0);
acb_hypgeom_gamma_lower(w1, a1, z, regularized, prec1);
acb_neg(enz, z);
acb_exp(enz, enz, prec0);
/* recurrence relations */
if (regularized == 2)
{
/* gamma^{*}(a,z) - exp(-z)/Gamma(a+1) - z gamma^{*}(a+1,z) = 0 */
/* http://dlmf.nist.gov/8.8.E4 */
acb_set(t, w0);
acb_rgamma(u, a1, prec0);
acb_submul(t, enz, u, prec0);
acb_submul(t, z, w1, prec0);
}
else if (regularized == 1)
{
/* P(a,z) - exp(-z) z^a / Gamma(a+1) - P(a+1,z) = 0 */
/* http://dlmf.nist.gov/8.8.E5 */
acb_pow(u, z, a0, prec0);
acb_rgamma(b, a1, prec0);
acb_mul(u, u, b, prec0);
acb_sub(t, w0, w1, prec0);
acb_submul(t, enz, u, prec0);
}
else
{
/* a gamma(a,z) - exp(-z) z^a - gamma(a+1,z) = 0 */
/* http://dlmf.nist.gov/8.8.E1 */
acb_pow(u, z, a0, prec0);
acb_mul(t, a0, w0, prec0);
acb_submul(t, enz, u, prec0);
acb_sub(t, t, w1, prec0);
}
if (!acb_contains_zero(t))
{
flint_printf("FAIL: recurrence relation\n\n");
flint_printf("regularized = %d\n\n", regularized);
flint_printf("a0 = "); acb_printd(a0, 30); flint_printf("\n\n");
flint_printf("z = "); acb_printd(z, 30); flint_printf("\n\n");
flint_printf("w0 = "); acb_printd(w0, 30); flint_printf("\n\n");
flint_printf("w1 = "); acb_printd(w1, 30); flint_printf("\n\n");
flint_printf("t = "); acb_printd(t, 30); flint_printf("\n\n");
abort();
}
/* identities relating lower and upper incomplete gamma functions */
if (regularized == 0 || regularized == 1)
{
acb_t u0;
acb_init(u0);
acb_hypgeom_gamma_upper(u0, a0, z, regularized, prec0);
acb_zero(t);
if (regularized == 1)
{
/* P(s,z) + Q(s,z) - 1 = 0 */
/* http://dlmf.nist.gov/8.2.E5 */
acb_add(t, w0, u0, prec0);
acb_sub_ui(t, t, 1, prec0);
}
else
{
/* gamma(s,z) + Gamma(s,z) - Gamma(s) = 0 */
/* excludes non-positive integer values of s */
/* http://dlmf.nist.gov/8.2.E3 */
if (!acb_is_int(a0) || arb_is_positive(acb_realref(a0)))
{
acb_gamma(b, a0, prec0);
acb_add(t, w0, u0, prec0);
acb_sub(t, t, b, prec0);
}
}
if (!acb_contains_zero(t))
{
flint_printf("FAIL: lower plus upper\n\n");
flint_printf("regularized = %d\n\n", regularized);
flint_printf("a0 = "); acb_printd(a0, 30); flint_printf("\n\n");
flint_printf("z = "); acb_printd(z, 30); flint_printf("\n\n");
flint_printf("w0 = "); acb_printd(w0, 30); flint_printf("\n\n");
flint_printf("w1 = "); acb_printd(w1, 30); flint_printf("\n\n");
flint_printf("t = "); acb_printd(t, 30); flint_printf("\n\n");
abort();
}
acb_clear(u0);
}
acb_clear(a0);
acb_clear(a1);
acb_clear(b);
acb_clear(z);
acb_clear(w0);
acb_clear(w1);
acb_clear(t);
acb_clear(u);
acb_clear(enz);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
