git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@26 f3b2605a-c512-4ea7-a41b-209d697bcdaa

2006-09-27 19:51:33 +00:00
parent 3422cb245c
commit 222c95507e
536 changed files with 108384 additions and 0 deletions
--- a/src/fix_ave_force.cpp
+++ b/src/fix_ave_force.cpp
@ -0,0 +1,171 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   www.cs.sandia.gov/~sjplimp/lammps.html
+   Steve Plimpton, sjplimp@sandia.gov, Sandia National Laboratories
+
+   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 "mpi.h"
+#include "string.h"
+#include "stdlib.h"
+#include "fix_ave_force.h"
+#include "atom.h"
+#include "update.h"
+#include "respa.h"
+#include "error.h"
+
+/* ---------------------------------------------------------------------- */
+
+FixAveForce::FixAveForce(int narg, char **arg) : Fix(narg, arg)
+{
+  if (narg != 6) error->all("Illegal fix aveforce command");
+
+  xflag = yflag = zflag = 1;
+  if (strcmp(arg[3],"NULL") == 0) xflag = 0;
+  else xvalue = atof(arg[3]);
+  if (strcmp(arg[4],"NULL") == 0) yflag = 0;
+  else yvalue = atof(arg[4]);
+  if (strcmp(arg[5],"NULL") == 0) zflag = 0;
+  else zvalue = atof(arg[5]);
+}
+
+/* ---------------------------------------------------------------------- */
+
+int FixAveForce::setmask()
+{
+  int mask = 0;
+  mask |= POST_FORCE;
+  mask |= POST_FORCE_RESPA;
+  mask |= MIN_POST_FORCE;
+  return mask;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixAveForce::init()
+{
+  if (strcmp(update->integrate_style,"respa") == 0)
+    nlevels_respa = ((Respa *) update->integrate)->nlevels;
+
+  // ncount = total # of atoms in group
+
+  int *mask = atom->mask;
+  int nlocal = atom->nlocal;
+
+  int count = 0;
+  for (int i = 0; i < nlocal; i++)
+    if (mask[i] & groupbit) count++;
+  MPI_Allreduce(&count,&ncount,1,MPI_INT,MPI_SUM,world);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixAveForce::setup()
+{
+  if (strcmp(update->integrate_style,"verlet") == 0)
+    post_force(1);
+  else
+    for (int ilevel = 0; ilevel < nlevels_respa; ilevel++) {
+      ((Respa *) update->integrate)->copy_flevel_f(ilevel);
+      post_force_respa(1,ilevel,0);
+      ((Respa *) update->integrate)->copy_f_flevel(ilevel);
+    }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixAveForce::min_setup()
+{
+  post_force(1);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixAveForce::post_force(int vflag)
+{
+  // sum forces on participating atoms
+
+  double **f = atom->f;
+  int *mask = atom->mask;
+  int nlocal = atom->nlocal;
+
+  double sum[3];
+  sum[0] = sum[1] = sum[2] = 0.0;
+
+  for (int i = 0; i < nlocal; i++)
+    if (mask[i] & groupbit) {
+      sum[0] += f[i][0];
+      sum[1] += f[i][1];
+      sum[2] += f[i][2];
+    }
+
+  // average the force on participating atoms
+  // add in requested amount
+
+  double sumall[3];
+  MPI_Allreduce(sum,sumall,3,MPI_DOUBLE,MPI_SUM,world);
+  sumall[0] = sumall[0]/ncount + xvalue;
+  sumall[1] = sumall[1]/ncount + yvalue;
+  sumall[2] = sumall[2]/ncount + zvalue;
+
+  // set force of all participating atoms to same value
+  // only for active dimensions
+
+  for (int i = 0; i < nlocal; i++)
+    if (mask[i] & groupbit) {
+      if (xflag) f[i][0] = sumall[0];
+      if (yflag) f[i][1] = sumall[1];
+      if (zflag) f[i][2] = sumall[2];
+    }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixAveForce::post_force_respa(int vflag, int ilevel, int iloop)
+{
+  // ave + extra force on outermost level
+  // just ave on inner levels
+
+  if (ilevel == nlevels_respa-1) post_force(vflag);
+  else {
+    double **f = atom->f;
+    int *mask = atom->mask;
+    int nlocal = atom->nlocal;
+
+    double sum[3];
+    sum[0] = sum[1] = sum[2] = 0.0;
+
+    for (int i = 0; i < nlocal; i++)
+      if (mask[i] & groupbit) {
+	sum[0] += f[i][0];
+	sum[1] += f[i][1];
+	sum[2] += f[i][2];
+      }
+
+    double sumall[3];
+    MPI_Allreduce(sum,sumall,3,MPI_DOUBLE,MPI_SUM,world);
+    sumall[0] = sumall[0]/ncount;
+    sumall[1] = sumall[1]/ncount;
+    sumall[2] = sumall[2]/ncount;
+
+    for (int i = 0; i < nlocal; i++)
+      if (mask[i] & groupbit) {
+	if (xflag) f[i][0] = sumall[0];
+	if (yflag) f[i][1] = sumall[1];
+	if (zflag) f[i][2] = sumall[2];
+      }
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixAveForce::min_post_force(int vflag)
+{
+  post_force(vflag);
+}