compute_com.cpp
79922fb24136lammm-master-deprecated

compute_com.cpp
View Options

			/* ----------------------------------------------------------------------
			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 "compute_com.h"
			#include "update.h"
			#include "group.h"
			#include "error.h"

			using namespace LAMMPS_NS;

			/* ---------------------------------------------------------------------- */

			ComputeCOM::ComputeCOM(LAMMPS lmp, int narg, char *arg) :
			Compute(lmp, narg, arg)
			{
			if (narg != 3) error->all(FLERR,"Illegal compute com command");

			vector_flag = 1;
			size_vector = 3;
			extvector = 0;

			vector = new double[3];
			}

			/* ---------------------------------------------------------------------- */

			ComputeCOM::~ComputeCOM()
			{
			delete [] vector;
			}

			/* ---------------------------------------------------------------------- */

			void ComputeCOM::init()
			{
			masstotal = group->mass(igroup);
			}

			/* ---------------------------------------------------------------------- */

			void ComputeCOM::compute_vector()
			{
			invoked_vector = update->ntimestep;
			if (group->dynamic[igroup]) masstotal = group->mass(igroup);

			group->xcm(igroup,masstotal,vector);
			}