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lammps/src/REPLICA/compute_event_displace.cpp
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compute_event_displace.cpp
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/* ----------------------------------------------------------------------
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.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Mike Brown (SNL)
------------------------------------------------------------------------- */
#include "mpi.h"
#include "math.h"
#include "stdlib.h"
#include "string.h"
#include "compute_event_displace.h"
#include "atom.h"
#include "domain.h"
#include "modify.h"
#include "fix_event.h"
#include "memory.h"
#include "error.h"
#include "update.h"
using namespace LAMMPS_NS;
#define INVOKED_SCALAR 1
/* ---------------------------------------------------------------------- */
ComputeEventDisplace::ComputeEventDisplace(LAMMPS *lmp, int narg, char **arg) :
Compute(lmp, narg, arg)
{
if (narg != 4) error->all(FLERR,"Illegal compute event/displace command");
scalar_flag = 1;
extscalar = 0;
double displace_dist = atof(arg[3]);
if (displace_dist <= 0.0)
error->all(FLERR,"Distance must be > 0 for compute event/displace");
displace_distsq = displace_dist * displace_dist;
// fix event ID will be set later by PRD
id_event = NULL;
}
/* ---------------------------------------------------------------------- */
ComputeEventDisplace::~ComputeEventDisplace()
{
delete [] id_event;
}
/* ---------------------------------------------------------------------- */
void ComputeEventDisplace::init()
{
// if id_event is not set, this compute is not active
// if set by PRD, then find fix which stores original atom coords
// check if it is correct style
if (id_event != NULL) {
int ifix = modify->find_fix(id_event);
if (ifix < 0) error->all(FLERR,
"Could not find compute event/displace fix ID");
fix_event = (FixEvent*) modify->fix[ifix];
if (strcmp(fix_event->style,"EVENT/PRD") != 0 &&
strcmp(fix_event->style,"EVENT/TAD") != 0)
error->all(FLERR,"Compute event/displace has invalid fix event assigned");
}
triclinic = domain->triclinic;
}
/* ----------------------------------------------------------------------
return non-zero if an atom has moved > displace_dist since last event
------------------------------------------------------------------------- */
double ComputeEventDisplace::compute_scalar()
{
invoked_scalar = update->ntimestep;
if (id_event == NULL) return 0.0;
double event = 0.0;
double **xevent = fix_event->array_atom;
double **x = atom->x;
int *mask = atom->mask;
tagint *image = atom->image;
int nlocal = atom->nlocal;
double *h = domain->h;
double xprd = domain->xprd;
double yprd = domain->yprd;
double zprd = domain->zprd;
int xbox,ybox,zbox;
double dx,dy,dz,rsq;
if (triclinic == 0) {
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
xbox = (image[i] & IMGMASK) - IMGMAX;
ybox = (image[i] >> IMGBITS & IMGMASK) - IMGMAX;
zbox = (image[i] >> IMG2BITS) - IMGMAX;
dx = x[i][0] + xbox*xprd - xevent[i][0];
dy = x[i][1] + ybox*yprd - xevent[i][1];
dz = x[i][2] + zbox*zprd - xevent[i][2];
rsq = dx*dx + dy*dy + dz*dz;
if (rsq >= displace_distsq) {
event = 1.0;
break;
}
}
} else {
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
xbox = (image[i] & IMGMASK) - IMGMAX;
ybox = (image[i] >> IMGBITS & IMGMASK) - IMGMAX;
zbox = (image[i] >> IMG2BITS) - IMGMAX;
dx = x[i][0] + h[0]*xbox + h[5]*ybox + h[4]*zbox - xevent[i][0];
dy = x[i][1] + h[1]*ybox + h[3]*zbox - xevent[i][1];
dz = x[i][2] + h[2]*zbox - xevent[i][2];
rsq = dx*dx + dy*dy + dz*dz;
if (rsq >= displace_distsq) {
event = 1.0;
break;
}
}
}
MPI_Allreduce(&event,&scalar,1,MPI_DOUBLE,MPI_SUM,world);
return scalar;
}
/* ---------------------------------------------------------------------- */
void ComputeEventDisplace::reset_extra_compute_fix(const char *id_new)
{
delete [] id_event;
id_event = NULL;
if (id_new == NULL) return;
int n = strlen(id_new) + 1;
id_event = new char[n];
strcpy(id_event,id_new);
}
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