git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@3531 f3b2605a-c512-4ea7-a41b-209d697bcdaa

2009-12-15 01:21:02 +00:00
parent 964f1815d0
commit ff0a4b800c
11 changed files with 776 additions and 17 deletions
--- a/src/fix_lineforce.cpp
+++ b/src/fix_lineforce.cpp
@ -0,0 +1,107 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under 
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#include "math.h"
+#include "string.h"
+#include "stdlib.h"
+#include "fix_lineforce.h"
+#include "atom.h"
+#include "update.h"
+#include "respa.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+FixLineForce::FixLineForce(LAMMPS *lmp, int narg, char **arg) :
+  Fix(lmp, narg, arg)
+{
+  if (narg != 6) error->all("Illegal fix lineforce command");
+  xdir = atof(arg[3]);
+  ydir = atof(arg[4]);
+  zdir = atof(arg[5]);
+
+  double len = sqrt(xdir*xdir + ydir*ydir + zdir*zdir);
+  if (len == 0.0) error->all("Illegal fix lineforce command");
+
+  xdir /= len;
+  ydir /= len;
+  zdir /= len;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int FixLineForce::setmask()
+{
+  int mask = 0;
+  mask |= POST_FORCE;
+  mask |= POST_FORCE_RESPA;
+  mask |= MIN_POST_FORCE;
+  return mask;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixLineForce::setup(int vflag)
+{
+  if (strcmp(update->integrate_style,"verlet") == 0)
+    post_force(vflag);
+  else {
+    int nlevels_respa = ((Respa *) update->integrate)->nlevels;
+    for (int ilevel = 0; ilevel < nlevels_respa; ilevel++) {
+      ((Respa *) update->integrate)->copy_flevel_f(ilevel);
+      post_force_respa(vflag,ilevel,0);
+      ((Respa *) update->integrate)->copy_f_flevel(ilevel);
+    }
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixLineForce::min_setup(int vflag)
+{
+  post_force(vflag);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixLineForce::post_force(int vflag)
+{
+  double **f = atom->f;
+  int *mask = atom->mask;
+  int nlocal = atom->nlocal;
+
+  double dot;
+  for (int i = 0; i < nlocal; i++)
+    if (mask[i] & groupbit) {
+      dot = f[i][0]*xdir + f[i][1]*ydir + f[i][2]*zdir;
+      f[i][0] = dot * xdir;
+      f[i][1] = dot * ydir;
+      f[i][2] = dot * zdir;
+    }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixLineForce::post_force_respa(int vflag, int ilevel, int iloop)
+{
+  post_force(vflag);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixLineForce::min_post_force(int vflag)
+{
+  post_force(vflag);
+}