include/complex.h

   1 /*
   2  * $Id$
   3  *
   4  *       This source code is part of
   5  *
   6  *        G   R   O   M   A   C   S
   7  *
   8  * GROningen MAchine for Chemical Simulations
   9  *
  10  *               VERSION 2.0
  11  *
  12  * Copyright (c) 1991-1999
  13  * BIOSON Research Institute, Dept. of Biophysical Chemistry
  14  * University of Groningen, The Netherlands
  15  *
  16  * Please refer to:
  17  * GROMACS: A message-passing parallel molecular dynamics implementation
  18  * H.J.C. Berendsen, D. van der Spoel and R. van Drunen
  19  * Comp. Phys. Comm. 91, 43-56 (1995)
  20  *
  21  * Also check out our WWW page:
  22  * http://md.chem.rug.nl/~gmx
  23  * or e-mail to:
  24  * gromacs@chem.rug.nl
  25  *
  26  * And Hey:
  27  * Good ROcking Metal Altar for Chronical Sinners
  28  */
  29
  30 #ifndef _complex_h
  31 #define _complex_h
  32
  33 static char *SRCID_complex_h = "$Id$";
  34
  35 #include <math.h>
  36 #include "typedefs.h"
  37
  38 typedef struct {
  39   real re,im;
  40 } t_complex;
  41
  42 typedef t_complex cvec[DIM];
  43
  44 static t_complex cnul = { 0.0, 0.0 };
  45
  46 static t_complex rcmul(real r,t_complex c)
  47 {
  48   t_complex d;
  49
  50   d.re = r*c.re;
  51   d.im = r*c.im;
  52
  53   return d;
  54 }
  55
  56 static t_complex rcexp(real r)
  57 {
  58   t_complex c;
  59
  60   c.re = cos(r);
  61   c.im = sin(r);
  62
  63   return c;
  64 }
  65
  66
  67 static t_complex cadd(t_complex a,t_complex b)
  68 {
  69   t_complex c;
  70
  71   c.re = a.re+b.re;
  72   c.im = a.im+b.im;
  73
  74   return c;
  75 }
  76
  77 static t_complex csub(t_complex a,t_complex b)
  78 {
  79   t_complex c;
  80
  81   c.re = a.re-b.re;
  82   c.im = a.im-b.im;
  83
  84   return c;
  85 }
  86
  87 static t_complex cmul(t_complex a,t_complex b)
  88 {
  89   t_complex c;
  90
  91   c.re = a.re*b.re - a.im*b.im;
  92   c.im = a.re*b.im + a.im*b.re;
  93
  94   return c;
  95 }
  96
  97 static t_complex conjugate(t_complex c)
  98 {
  99   t_complex d;
 100
 101   d.re =  c.re;
 102   d.im = -c.im;
 103
 104   return d;
 105 }
 106
 107 static t_complex cdiv(t_complex teller,t_complex noemer)
 108 {
 109   t_complex res,anoemer;
 110
 111   anoemer = cmul(conjugate(noemer),noemer);
 112   res = cmul(teller,conjugate(noemer));
 113
 114   return rcmul(1.0/anoemer.re,res);
 115 }
 116 #endif