1 /*
2 Copyright (C) 2013 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 "arb.h"
13 #include "bernoulli.h"
14
15 void
arb_bernoulli_ui(arb_t b,ulong n,slong prec)16 arb_bernoulli_ui(arb_t b, ulong n, slong prec)
17 {
18 if (n < bernoulli_cache_num)
19 {
20 arb_set_fmpq(b, bernoulli_cache + n, prec);
21 }
22 else
23 {
24 int use_frac;
25
26 use_frac = (n < BERNOULLI_SMALL_NUMER_LIMIT) || (n % 2 != 0);
27 if (!use_frac && n < UWORD_MAX / 1000)
28 use_frac = (prec > bernoulli_global_prec(n));
29
30 if (use_frac)
31 {
32 fmpq_t t;
33 fmpq_init(t);
34 bernoulli_fmpq_ui(t, n);
35 arb_set_fmpq(b, t, prec);
36 fmpq_clear(t);
37 }
38 else
39 {
40 arb_bernoulli_ui_zeta(b, n, prec);
41 }
42 }
43 }
44
45