arb/acb_hypgeom/pfq_direct.c
2016-04-26 17:20:05 +02:00

50 lines
1.2 KiB
C

/*
Copyright (C) 2014 Fredrik Johansson
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "acb_hypgeom.h"
void
acb_hypgeom_pfq_direct(acb_t res, acb_srcptr a, slong p, acb_srcptr b, slong q,
const acb_t z, slong n, slong prec)
{
acb_t s, t;
mag_t err, C;
acb_init(s);
acb_init(t);
mag_init(err);
mag_init(C);
if (n < 0)
n = acb_hypgeom_pfq_choose_n(a, p, b, q, z, prec);
acb_hypgeom_pfq_sum(s, t, a, p, b, q, z, n, prec);
if (!acb_is_zero(t))
{
acb_hypgeom_pfq_bound_factor(C, a, p, b, q, z, n);
acb_get_mag(err, t);
mag_mul(err, err, C);
if (_acb_vec_is_real(a, p) && _acb_vec_is_real(b, q) && acb_is_real(z))
arb_add_error_mag(acb_realref(s), err);
else
acb_add_error_mag(s, err);
}
acb_set(res, s);
acb_clear(s);
acb_clear(t);
mag_clear(err);
mag_clear(C);
}