include/gmxcomplex.h

   1 /*
   2  * $Id: gmxcomplex.h,v 1.5 2009/03/07 13:30:36 lindahl Exp $
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   4  *                This source code is part of
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   8  *          GROningen MAchine for Chemical Simulations
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  36 #ifndef _gmxcomplex_h
  37 #define _gmxcomplex_h
  38
  39 #include <math.h>
  40 #include "typedefs.h"
  41
  42 typedef struct {
  43   real re,im;
  44 } t_complex;
  45
  46 typedef t_complex cvec[DIM];
  47
  48 static t_complex cnul = { 0.0, 0.0 };
  49
  50 static t_complex rcmul(real r,t_complex c)
  51 {
  52   t_complex d;
  53
  54   d.re = r*c.re;
  55   d.im = r*c.im;
  56
  57   return d;
  58 }
  59
  60 static t_complex rcexp(real r)
  61 {
  62   t_complex c;
  63
  64   c.re = (real)cos(r);
  65   c.im = (real)sin(r);
  66
  67   return c;
  68 }
  69
  70
  71 static t_complex cadd(t_complex a,t_complex b)
  72 {
  73   t_complex c;
  74
  75   c.re = a.re+b.re;
  76   c.im = a.im+b.im;
  77
  78   return c;
  79 }
  80
  81 static t_complex csub(t_complex a,t_complex b)
  82 {
  83   t_complex c;
  84
  85   c.re = a.re-b.re;
  86   c.im = a.im-b.im;
  87
  88   return c;
  89 }
  90
  91 static t_complex cmul(t_complex a,t_complex b)
  92 {
  93   t_complex c;
  94
  95   c.re = a.re*b.re - a.im*b.im;
  96   c.im = a.re*b.im + a.im*b.re;
  97
  98   return c;
  99 }
 100
 101 static t_complex conjugate(t_complex c)
 102 {
 103   t_complex d;
 104
 105   d.re =  c.re;
 106   d.im = -c.im;
 107
 108   return d;
 109 }
 110
 111 static real cabs2(t_complex c)
 112 {
 113 real abs2;
 114 abs2=(c.re*c.re)+(c.im*c.im);
 115
 116 return abs2;
 117 }
 118
 119
 120
 121 static t_complex cdiv(t_complex teller,t_complex noemer)
 122 {
 123   t_complex res,anoemer;
 124
 125   anoemer = cmul(conjugate(noemer),noemer);
 126   res = cmul(teller,conjugate(noemer));
 127
 128   return rcmul(1.0/anoemer.re,res);
 129 }
 130 #endif