include/gmxcomplex.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 3.1
  11  * Copyright (c) 1991-2001, University of Groningen, The Netherlands
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * If you want to redistribute modifications, please consider that
  18  * scientific software is very special. Version control is crucial -
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  22  * files - if they are missing, get the official version at www.gromacs.org.
  23  *
  24  * To help us fund GROMACS development, we humbly ask that you cite
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  27  * For more info, check our website at http://www.gromacs.org
  28  *
  29  * And Hey:
  30  * Grunge ROck MAChoS
  31  */
  32 #ifndef _complex_h
  33 #define _complex_h
  34
  35 static char *SRCID_complex_h = "$Id$";
  36
  37 #ifdef HAVE_CONFIG_H
  38 #include <config.h>
  39 #endif
  40
  41 #include <math.h>
  42 #include "typedefs.h"
  43
  44 typedef struct {
  45   real re,im;
  46 } t_complex;
  47
  48 typedef t_complex cvec[DIM];
  49
  50 static t_complex cnul = { 0.0, 0.0 };
  51
  52 static t_complex rcmul(real r,t_complex c)
  53 {
  54   t_complex d;
  55
  56   d.re = r*c.re;
  57   d.im = r*c.im;
  58
  59   return d;
  60 }
  61
  62 static t_complex rcexp(real r)
  63 {
  64   t_complex c;
  65
  66   c.re = cos(r);
  67   c.im = sin(r);
  68
  69   return c;
  70 }
  71
  72
  73 static t_complex cadd(t_complex a,t_complex b)
  74 {
  75   t_complex c;
  76
  77   c.re = a.re+b.re;
  78   c.im = a.im+b.im;
  79
  80   return c;
  81 }
  82
  83 static t_complex csub(t_complex a,t_complex b)
  84 {
  85   t_complex c;
  86
  87   c.re = a.re-b.re;
  88   c.im = a.im-b.im;
  89
  90   return c;
  91 }
  92
  93 static t_complex cmul(t_complex a,t_complex b)
  94 {
  95   t_complex c;
  96
  97   c.re = a.re*b.re - a.im*b.im;
  98   c.im = a.re*b.im + a.im*b.re;
  99
 100   return c;
 101 }
 102
 103 static t_complex conjugate(t_complex c)
 104 {
 105   t_complex d;
 106
 107   d.re =  c.re;
 108   d.im = -c.im;
 109
 110   return d;
 111 }
 112
 113 static t_complex cdiv(t_complex teller,t_complex noemer)
 114 {
 115   t_complex res,anoemer;
 116
 117   anoemer = cmul(conjugate(noemer),noemer);
 118   res = cmul(teller,conjugate(noemer));
 119
 120   return rcmul(1.0/anoemer.re,res);
 121 }
 122 #endif