include/princ.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 _princ_h
  31 #define _princ_h
  32
  33 static char *SRCID_princ_h = "$Id$";
  34
  35 #include "typedefs.h"
  36
  37 extern void pr_jacobi(real **a,int n,real d[],real **v,int *nrot);
  38
  39 extern void rotate_atoms(int gnx,atom_id index[],rvec x[],matrix trans);
  40 /* Rotate all atoms in index using matrix trans */
  41
  42 extern void principal_comp(int n,atom_id index[],t_atom atom[],rvec x[],
  43                            matrix trans,rvec d);
  44 /* Calculate the principal components of atoms in index. Atoms are
  45  * mass weighted. It is assumed that the center of mass is in the origin!
  46  */
  47
  48 extern real calc_xcm(rvec x[],int gnx,atom_id index[],t_atom atom[],rvec xcm,
  49                      bool bQ);
  50 /* Calculate the center of mass of the atoms in index. if bQ then the atoms
  51  * will be charge weighted rather than mass weighted.
  52  * Returns the total mass/charge.
  53  */
  54
  55 extern real sub_xcm(rvec x[],int gnx,atom_id index[],t_atom atom[],rvec xcm,
  56                     bool bQ);
  57 /* Calc. the center of mass and subtract it from all coordinates.
  58  * Returns the original center of mass in xcm
  59  * Returns the total mass
  60  */
  61
  62 extern void add_xcm(rvec x[],int gnx,atom_id index[],rvec xcm);
  63 /* Increment all atoms in index with xcm */
  64
  65 #endif