Add hyperbolic cosine function.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpc/trunk@129 211d60ee-9f03-0410-a15a-8952a2c7a4e4

1 files changed, 38 insertions, 0 deletions

diff --git a/src/cosh.c b/src/cosh.c
new file mode 100644
index 0000000..4f8849f
--- /dev/null
+++ b/src/cosh.c
@@ -0,0 +1,38 @@
+/* mpc_cosh -- hyperbolic cosine of a complex number.
+
+Copyright (C) 2008 Philippe Th\'eveny
+
+This file is part of the MPC Library.
+
+The MPC Library 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 2.1 of the License, or (at your
+option) any later version.
+
+The MPC Library 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 the MPC Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "mpfr.h"
+#include "mpc.h"
+#include "mpc-impl.h"
+
+void
+mpc_cosh (mpc_ptr rop, mpc_srcptr op, mpc_rnd_t rnd)
+{
+  /* cosh(op) = cos(i*op) */
+  mpc_t z;
+
+  mpc_init3 (z, MPFR_PREC (MPC_IM (op)), MPFR_PREC (MPC_RE (op)));
+
+  mpc_mul_i (z, op, +1, MPC_RNDNN); /* exact */
+  mpc_cos (rop, z, rnd);
+
+  mpc_clear (z);
+}