/*
 * $Id: gmxcomplex.h,v 1.5 2009/03/07 13:30:36 lindahl Exp $
 * 
 *                This source code is part of
 * 
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 * 
 *          GROningen MAchine for Chemical Simulations
 * 
 *                        VERSION 3.2.0
 * Written by David van der Spoel, Erik Lindahl, Berk Hess, and others.
 * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
 * Copyright (c) 2001-2004, The GROMACS development team,
 * check out http://www.gromacs.org for more information.

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#ifndef _gmxcomplex_h
#define _gmxcomplex_h

#include <math.h>
#include "typedefs.h"

typedef struct {
  real re,im;
} t_complex;

typedef t_complex cvec[DIM];

static t_complex cnul = { 0.0, 0.0 };

static t_complex rcmul(real r,t_complex c)
{
  t_complex d;
  
  d.re = r*c.re;
  d.im = r*c.im;
  
  return d;
}

static t_complex rcexp(real r)
{
  t_complex c;
  
  c.re = (real)cos(r);
  c.im = (real)sin(r);
  
  return c;
}


static t_complex cadd(t_complex a,t_complex b)
{
  t_complex c;
  
  c.re = a.re+b.re;
  c.im = a.im+b.im;
  
  return c;
}

static t_complex csub(t_complex a,t_complex b)
{
  t_complex c;
  
  c.re = a.re-b.re;
  c.im = a.im-b.im;
  
  return c;
}

static t_complex cmul(t_complex a,t_complex b)
{
  t_complex c;
  
  c.re = a.re*b.re - a.im*b.im;
  c.im = a.re*b.im + a.im*b.re;
  
  return c;
}

static t_complex conjugate(t_complex c)
{
  t_complex d;
  
  d.re =  c.re;
  d.im = -c.im;
  
  return d;
}

static real cabs2(t_complex c)
{
real abs2;
abs2=(c.re*c.re)+(c.im*c.im);

return abs2;
}



static t_complex cdiv(t_complex teller,t_complex noemer)
{
  t_complex res,anoemer;
  
  anoemer = cmul(conjugate(noemer),noemer);
  res = cmul(teller,conjugate(noemer));
  
  return rcmul(1.0/anoemer.re,res);
}
#endif
