1 /*
2 Copyright (C) 2015 Fredrik Johansson
3
4 This file is part of Arb.
5
6 Arb is free software: you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version. See <http://www.gnu.org/licenses/>.
10 */
11
12 #include "acb_hypgeom.h"
13
14 void
acb_hypgeom_expint(acb_t res,const acb_t s,const acb_t z,slong prec)15 acb_hypgeom_expint(acb_t res, const acb_t s, const acb_t z, slong prec)
16 {
17 acb_t t;
18 acb_init(t);
19 acb_sub_ui(t, s, 1, prec);
20 acb_neg(t, t);
21 acb_hypgeom_gamma_upper(res, t, z, 2, prec);
22 acb_clear(t);
23 }
24
25