/* Complex trig functions
   Copyright 2002 Free Software Foundation, Inc.
   Contributed by Paul Brook <paul@nowt.org>

This file is part of the GNU Fortran 95 runtime library (libgfor).

Libgfortran 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.

Libgfortran 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 libgfor; 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 <math.h>
#include "libgfortran.h"


/* Complex number z = a + ib.  */

/* sin(z) = sin(a)cosh(b) + icos(a)sinh(b)  */
GFC_COMPLEX_8
csin (GFC_COMPLEX_8 a)
{
  GFC_REAL_8 r;
  GFC_REAL_8 i;
  GFC_COMPLEX_8 v;

  r = REALPART (a);
  i = IMAGPART (a);
  COMPLEX_ASSIGN (v, sin (r) * cosh (i), cos (r) * sinh (i));
  return v;
}

/* cos(z) = cos(a)cosh(b) - isin(a)sinh(b)  */
GFC_COMPLEX_8
ccos (GFC_COMPLEX_8 a)
{
  GFC_REAL_8 r;
  GFC_REAL_8 i;
  GFC_COMPLEX_8 v;

  r = REALPART (a);
  i = IMAGPART (a);
  COMPLEX_ASSIGN (v, cos (r) * cosh (i), - (sin (r) * sinh (i)));
  return v;
}

/* tan(z) = (tan(a) + itanh(b)) / (1 - itan(a)tanh(b))  */
GFC_COMPLEX_8
ctan (GFC_COMPLEX_8 a)
{
  GFC_REAL_8 rt;
  GFC_REAL_8 it;
  GFC_COMPLEX_8 n;
  GFC_COMPLEX_8 d;

  rt = tan (REALPART (a));
  it = tanh (IMAGPART (a));
  COMPLEX_ASSIGN (n, rt, it);
  COMPLEX_ASSIGN (d , 1, - (rt * it));

  return n / d;
}