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Diffstat (limited to 'mpc/src/asinh.c')
-rw-r--r-- | mpc/src/asinh.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/mpc/src/asinh.c b/mpc/src/asinh.c new file mode 100644 index 0000000000..2807a8bb31 --- /dev/null +++ b/mpc/src/asinh.c @@ -0,0 +1,55 @@ +/* mpc_asinh -- inverse hyperbolic sine of a complex number. + +Copyright (C) 2009, 2011, 2012 INRIA + +This file is part of GNU MPC. + +GNU MPC is free software; you can redistribute it and/or modify it under +the terms of the GNU Lesser General Public License as published by the +Free Software Foundation; either version 3 of the License, or (at your +option) any later version. + +GNU MPC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for +more details. + +You should have received a copy of the GNU Lesser General Public License +along with this program. If not, see http://www.gnu.org/licenses/ . +*/ + +#include "mpc-impl.h" + +int +mpc_asinh (mpc_ptr rop, mpc_srcptr op, mpc_rnd_t rnd) +{ + /* asinh(op) = -i*asin(i*op) */ + int inex; + mpc_t z, a; + mpfr_t tmp; + + /* z = i*op */ + mpc_realref (z)[0] = mpc_imagref (op)[0]; + mpc_imagref (z)[0] = mpc_realref (op)[0]; + MPFR_CHANGE_SIGN (mpc_realref (z)); + + /* Note reversal of precisions due to later multiplication by -i */ + mpc_init3 (a, MPC_PREC_IM(rop), MPC_PREC_RE(rop)); + + inex = mpc_asin (a, z, + MPC_RND (INV_RND (MPC_RND_IM (rnd)), MPC_RND_RE (rnd))); + + /* if a = asin(i*op) = x+i*y, and we want y-i*x */ + + /* change a to -i*a */ + tmp[0] = mpc_realref (a)[0]; + mpc_realref (a)[0] = mpc_imagref (a)[0]; + mpc_imagref (a)[0] = tmp[0]; + MPFR_CHANGE_SIGN (mpc_imagref (a)); + + mpc_set (rop, a, MPC_RNDNN); /* exact */ + + mpc_clear (a); + + return MPC_INEX (MPC_INEX_IM (inex), -MPC_INEX_RE (inex)); +} |