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 "acb_poly.h"
13
14 void
_acb_poly_sinh_cosh_series(acb_ptr s,acb_ptr c,acb_srcptr h,slong hlen,slong n,slong prec)15 _acb_poly_sinh_cosh_series(acb_ptr s, acb_ptr c, acb_srcptr h, slong hlen, slong n, slong prec)
16 {
17 hlen = FLINT_MIN(hlen, n);
18
19 if (hlen == 1)
20 {
21 acb_sinh_cosh(s, c, h, prec);
22 _acb_vec_zero(s + 1, n - 1);
23 _acb_vec_zero(c + 1, n - 1);
24 }
25 else if (n == 2)
26 {
27 acb_t t;
28 acb_init(t);
29 acb_set(t, h + 1);
30 acb_sinh_cosh(s, c, h, prec);
31 acb_mul(s + 1, c, t, prec);
32 acb_mul(c + 1, s, t, prec);
33 acb_clear(t);
34 }
35 else
36 {
37 slong cutoff;
38
39 if (prec <= 128)
40 cutoff = 400;
41 else
42 cutoff = 30000 / pow(log(prec), 3);
43
44 if (hlen < cutoff)
45 _acb_poly_sinh_cosh_series_basecase(s, c, h, hlen, n, prec);
46 else
47 _acb_poly_sinh_cosh_series_exponential(s, c, h, hlen, n, prec);
48 }
49 }
50
51 void
acb_poly_sinh_cosh_series(acb_poly_t s,acb_poly_t c,const acb_poly_t h,slong n,slong prec)52 acb_poly_sinh_cosh_series(acb_poly_t s, acb_poly_t c,
53 const acb_poly_t h, slong n, slong prec)
54 {
55 slong hlen = h->length;
56
57 if (n == 0)
58 {
59 acb_poly_zero(s);
60 acb_poly_zero(c);
61 return;
62 }
63
64 if (hlen == 0)
65 {
66 acb_poly_zero(s);
67 acb_poly_one(c);
68 return;
69 }
70
71 if (hlen == 1)
72 n = 1;
73
74 acb_poly_fit_length(s, n);
75 acb_poly_fit_length(c, n);
76 _acb_poly_sinh_cosh_series(s->coeffs, c->coeffs, h->coeffs, hlen, n, prec);
77 _acb_poly_set_length(s, n);
78 _acb_poly_normalise(s);
79 _acb_poly_set_length(c, n);
80 _acb_poly_normalise(c);
81 }
82