git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@255 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/compute_ke_atom.cpp

@@ -0,0 +1,104 @@
+/* ----------------------------------------------------------------------
+   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 "string.h"
+#include "compute_ke_atom.h"
+#include "atom.h"
+#include "modify.h"
+#include "comm.h"
+#include "force.h"
+#include "memory.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+ComputeKEAtom::ComputeKEAtom(LAMMPS *lmp, int narg, char **arg) :
+  Compute(lmp, narg, arg)
+{
+  if (narg != 3) error->all("Illegal compute ke/atom command");
+
+  peratom_flag = 1;
+  size_peratom = 0;
+
+  nmax = 0;
+  ke = NULL;
+}
+
+/* ---------------------------------------------------------------------- */
+
+ComputeKEAtom::~ComputeKEAtom()
+{
+  memory->sfree(ke);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeKEAtom::init()
+{
+  int count = 0;
+  for (int i = 0; i < modify->ncompute; i++)
+    if (strcmp(modify->compute[i]->style,"ke/atom") == 0) count++;
+  if (count > 1 && comm->me == 0)
+    error->warning("More than one compute ke/atom defined");
+}
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeKEAtom::compute_peratom()
+{
+  // grow ke array if necessary
+
+  if (atom->nlocal > nmax) {
+    memory->sfree(ke);
+    nmax = atom->nmax;
+    ke = (double *) memory->smalloc(nmax*sizeof(double),"compute/ke/atom:ke");
+    scalar_atom = ke;
+  }
+
+  // compute kinetic energy for each atom in group
+
+  double mvv2e = force->mvv2e;
+  double **v = atom->v;
+  double *mass = atom->mass;
+  double *rmass = atom->rmass;
+  int *mask = atom->mask;
+  int *type = atom->type;
+  int nlocal = atom->nlocal;
+
+  if (mass)
+    for (int i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	ke[i] = 0.5 * mvv2e * mass[type[i]] *
+	  (v[i][0]*v[i][0] + v[i][1]*v[i][1] + v[i][2]*v[i][2]);
+      }
+    }
+  else
+    for (int i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	ke[i] = 0.5 * mvv2e * rmass[i] *
+	  (v[i][0]*v[i][0] + v[i][1]*v[i][1] + v[i][2]*v[i][2]);
+      }
+    }
+}
+
+/* ----------------------------------------------------------------------
+   memory usage of local atom-based array
+------------------------------------------------------------------------- */
+
+int ComputeKEAtom::memory_usage()
+{
+  int bytes = nmax * sizeof(double);
+  return bytes;
+}