1 /* mpc_asinh -- inverse hyperbolic sine of a complex number.
2
3 Copyright (C) 2009, 2011, 2012 INRIA
4
5 This file is part of GNU MPC.
6
7 GNU MPC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU Lesser General Public License as published by the
9 Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
11
12 GNU MPC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15 more details.
16
17 You should have received a copy of the GNU Lesser General Public License
18 along with this program. If not, see http://www.gnu.org/licenses/ .
19 */
20
21 #include "mpc-impl.h"
22
23 int
mpc_asinh(mpc_ptr rop,mpc_srcptr op,mpc_rnd_t rnd)24 mpc_asinh (mpc_ptr rop, mpc_srcptr op, mpc_rnd_t rnd)
25 {
26 /* asinh(op) = -i*asin(i*op) */
27 int inex;
28 mpc_t z, a;
29 mpfr_t tmp;
30
31 /* z = i*op */
32 mpc_realref (z)[0] = mpc_imagref (op)[0];
33 mpc_imagref (z)[0] = mpc_realref (op)[0];
34 MPFR_CHANGE_SIGN (mpc_realref (z));
35
36 /* Note reversal of precisions due to later multiplication by -i */
37 mpc_init3 (a, MPC_PREC_IM(rop), MPC_PREC_RE(rop));
38
39 inex = mpc_asin (a, z,
40 MPC_RND (INV_RND (MPC_RND_IM (rnd)), MPC_RND_RE (rnd)));
41
42 /* if a = asin(i*op) = x+i*y, and we want y-i*x */
43
44 /* change a to -i*a */
45 tmp[0] = mpc_realref (a)[0];
46 mpc_realref (a)[0] = mpc_imagref (a)[0];
47 mpc_imagref (a)[0] = tmp[0];
48 MPFR_CHANGE_SIGN (mpc_imagref (a));
49
50 mpc_set (rop, a, MPC_RNDNN); /* exact */
51
52 mpc_clear (a);
53
54 return MPC_INEX (MPC_INEX_IM (inex), -MPC_INEX_RE (inex));
55 }
56