1 /* mpc_tanh -- hyperbolic tangent of a complex number.
3 Copyright (C) 2008, 2009, 2011, 2012 INRIA
5 This file is part of GNU MPC.
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.
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
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/ .
24 mpc_tanh (mpc_ptr rop
, mpc_srcptr op
, mpc_rnd_t rnd
)
26 /* tanh(op) = -i*tan(i*op) = conj(-i*tan(conj(-i*op))) */
31 /* z := conj(-i * op) and rop = conj(-i * tan(z)), in other words, we have
32 to switch real and imaginary parts. Let us set them without copying
34 mpc_realref (z
)[0] = mpc_imagref (op
)[0];
35 mpc_imagref (z
)[0] = mpc_realref (op
)[0];
36 mpc_realref (tan_z
)[0] = mpc_imagref (rop
)[0];
37 mpc_imagref (tan_z
)[0] = mpc_realref (rop
)[0];
39 inex
= mpc_tan (tan_z
, z
, MPC_RND (MPC_RND_IM (rnd
), MPC_RND_RE (rnd
)));
41 /* tan_z and rop parts share the same significands, copy the rest now. */
42 mpc_realref (rop
)[0] = mpc_imagref (tan_z
)[0];
43 mpc_imagref (rop
)[0] = mpc_realref (tan_z
)[0];
45 /* swap inexact flags for real and imaginary parts */
46 return MPC_INEX (MPC_INEX_IM (inex
), MPC_INEX_RE (inex
));