src/gromacs/math/gmxcomplex.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
   5  * Copyright (c) 2001-2004, The GROMACS development team.
   6  * Copyright (c) 2012,2014,2017, by the GROMACS development team, led by
   7  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   8  * and including many others, as listed in the AUTHORS file in the
   9  * top-level source directory and at http://www.gromacs.org.
  10  *
  11  * GROMACS is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public License
  13  * as published by the Free Software Foundation; either version 2.1
  14  * of the License, or (at your option) any later version.
  15  *
  16  * GROMACS is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with GROMACS; if not, see
  23  * http://www.gnu.org/licenses, or write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
  25  *
  26  * If you want to redistribute modifications to GROMACS, please
  27  * consider that scientific software is very special. Version
  28  * control is crucial - bugs must be traceable. We will be happy to
  29  * consider code for inclusion in the official distribution, but
  30  * derived work must not be called official GROMACS. Details are found
  31  * in the README & COPYING files - if they are missing, get the
  32  * official version at http://www.gromacs.org.
  33  *
  34  * To help us fund GROMACS development, we humbly ask that you cite
  35  * the research papers on the package. Check out http://www.gromacs.org.
  36  */
  37 #ifndef GMX_MATH_GMXCOMPLEX_H
  38 #define GMX_MATH_GMXCOMPLEX_H
  39
  40 #include <cmath>
  41
  42 #include "gromacs/math/vectypes.h"
  43 #include "gromacs/utility/real.h"
  44
  45 struct t_complex{
  46     real re, im;
  47 };
  48
  49 typedef t_complex cvec[DIM];
  50
  51 static t_complex rcmul(real r, t_complex c)
  52 {
  53     t_complex d;
  54
  55     d.re = r*c.re;
  56     d.im = r*c.im;
  57
  58     return d;
  59 }
  60
  61 static inline t_complex rcexp(real r)
  62 {
  63     t_complex c;
  64
  65     c.re = (real)cos(r);
  66     c.im = (real)sin(r);
  67
  68     return c;
  69 }
  70
  71
  72 static inline t_complex cadd(t_complex a, t_complex b)
  73 {
  74     t_complex c;
  75
  76     c.re = a.re+b.re;
  77     c.im = a.im+b.im;
  78
  79     return c;
  80 }
  81
  82 static inline t_complex csub(t_complex a, t_complex b)
  83 {
  84     t_complex c;
  85
  86     c.re = a.re-b.re;
  87     c.im = a.im-b.im;
  88
  89     return c;
  90 }
  91
  92 static t_complex cmul(t_complex a, t_complex b)
  93 {
  94     t_complex c;
  95
  96     c.re = a.re*b.re - a.im*b.im;
  97     c.im = a.re*b.im + a.im*b.re;
  98
  99     return c;
 100 }
 101
 102 static t_complex conjugate(t_complex c)
 103 {
 104     t_complex d;
 105
 106     d.re =  c.re;
 107     d.im = -c.im;
 108
 109     return d;
 110 }
 111
 112 static inline real cabs2(t_complex c)
 113 {
 114     real abs2;
 115     abs2 = (c.re*c.re)+(c.im*c.im);
 116
 117     return abs2;
 118 }
 119
 120 static inline t_complex cdiv(t_complex teller, t_complex noemer)
 121 {
 122     t_complex res, anoemer;
 123
 124     anoemer = cmul(conjugate(noemer), noemer);
 125     res     = cmul(teller, conjugate(noemer));
 126
 127     return rcmul(1.0/anoemer.re, res);
 128 }
 129
 130 inline bool operator==(const t_complex &lhs, const t_complex &rhs){ return (lhs.re == rhs.re) && (lhs.im == rhs.im); }
 131 inline bool operator!=(const t_complex &lhs, const t_complex &rhs){ return !(lhs == rhs); }
 132
 133 #endif