Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F81599262
compute_force_tally.cpp
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Fri, Sep 6, 23:26
Size
6 KB
Mime Type
text/x-c
Expires
Sun, Sep 8, 23:26 (2 d)
Engine
blob
Format
Raw Data
Handle
20554644
Attached To
rLAMMPS lammps
compute_force_tally.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 <string.h>
#include "compute_force_tally.h"
#include "atom.h"
#include "group.h"
#include "pair.h"
#include "update.h"
#include "memory.h"
#include "error.h"
#include "force.h"
using namespace LAMMPS_NS;
/* ---------------------------------------------------------------------- */
ComputeForceTally::ComputeForceTally(LAMMPS *lmp, int narg, char **arg) :
Compute(lmp, narg, arg)
{
if (narg < 4) error->all(FLERR,"Illegal compute force/tally command");
igroup2 = group->find(arg[3]);
if (igroup2 == -1)
error->all(FLERR,"Could not find compute force/tally second group ID");
groupbit2 = group->bitmask[igroup2];
scalar_flag = 1;
vector_flag = 0;
peratom_flag = 1;
timeflag = 1;
comm_reverse = size_peratom_cols = 3;
extscalar = 1;
peflag = 1; // we need Pair::ev_tally() to be run
did_compute = 0;
invoked_peratom = invoked_scalar = -1;
nmax = -1;
fatom = NULL;
vector = new double[size_peratom_cols];
}
/* ---------------------------------------------------------------------- */
ComputeForceTally::~ComputeForceTally()
{
if (force && force->pair) force->pair->del_tally_callback(this);
memory->destroy(fatom);
delete[] vector;
}
/* ---------------------------------------------------------------------- */
void ComputeForceTally::init()
{
if (force->pair == NULL)
error->all(FLERR,"Trying to use compute force/tally with no pair style");
else
force->pair->add_tally_callback(this);
if (force->pair->single_enable == 0 || force->pair->manybody_flag)
error->all(FLERR,"Compute force/tally used with incompatible pair style.");
if ((comm->me == 0) && (force->bond || force->angle || force->dihedral
|| force->improper || force->kspace))
error->warning(FLERR,"Compute force/tally only called from pair style");
did_compute = -1;
}
/* ---------------------------------------------------------------------- */
void ComputeForceTally::pair_tally_callback(int i, int j, int nlocal, int newton,
double, double, double fpair,
double dx, double dy, double dz)
{
const int ntotal = atom->nlocal + atom->nghost;
const int * const mask = atom->mask;
// do setup work that needs to be done only once per timestep
if (did_compute != update->ntimestep) {
did_compute = update->ntimestep;
// grow local force array if necessary
// needs to be atom->nmax in length
if (atom->nmax > nmax) {
memory->destroy(fatom);
nmax = atom->nmax;
memory->create(fatom,nmax,size_peratom_cols,"force/tally:fatom");
array_atom = fatom;
}
// clear storage as needed
if (newton) {
for (int i=0; i < ntotal; ++i)
for (int j=0; j < size_peratom_cols; ++j)
fatom[i][j] = 0.0;
} else {
for (int i=0; i < atom->nlocal; ++i)
for (int j=0; j < size_peratom_cols; ++j)
fatom[i][j] = 0.0;
}
for (int i=0; i < size_peratom_cols; ++i)
vector[i] = ftotal[i] = 0.0;
}
if ( ((mask[i] & groupbit) && (mask[j] & groupbit2))
|| ((mask[i] & groupbit2) && (mask[j] & groupbit)) ) {
if (newton || i < nlocal) {
if (mask[i] & groupbit) {
ftotal[0] += fpair*dx;
ftotal[1] += fpair*dy;
ftotal[2] += fpair*dz;
}
fatom[i][0] += fpair*dx;
fatom[i][1] += fpair*dy;
fatom[i][2] += fpair*dz;
}
if (newton || j < nlocal) {
if (mask[j] & groupbit) {
ftotal[0] -= fpair*dx;
ftotal[1] -= fpair*dy;
ftotal[2] -= fpair*dz;
}
fatom[j][0] -= fpair*dx;
fatom[j][1] -= fpair*dy;
fatom[j][2] -= fpair*dz;
}
}
}
/* ---------------------------------------------------------------------- */
int ComputeForceTally::pack_reverse_comm(int n, int first, double *buf)
{
int i,m,last;
m = 0;
last = first + n;
for (i = first; i < last; i++) {
buf[m++] = fatom[i][0];
buf[m++] = fatom[i][1];
buf[m++] = fatom[i][2];
}
return m;
}
/* ---------------------------------------------------------------------- */
void ComputeForceTally::unpack_reverse_comm(int n, int *list, double *buf)
{
int i,j,m;
m = 0;
for (i = 0; i < n; i++) {
j = list[i];
fatom[j][0] += buf[m++];
fatom[j][1] += buf[m++];
fatom[j][2] += buf[m++];
}
}
/* ---------------------------------------------------------------------- */
double ComputeForceTally::compute_scalar()
{
invoked_scalar = update->ntimestep;
if ((did_compute != invoked_scalar) || (update->eflag_global != invoked_scalar))
error->all(FLERR,"Energy was not tallied on needed timestep");
// sum accumulated forces across procs
MPI_Allreduce(ftotal,vector,size_peratom_cols,MPI_DOUBLE,MPI_SUM,world);
scalar = sqrt(vector[0]*vector[0]+vector[1]*vector[1]+vector[2]*vector[2]);
return scalar;
}
/* ---------------------------------------------------------------------- */
void ComputeForceTally::compute_peratom()
{
invoked_peratom = update->ntimestep;
if ((did_compute != invoked_peratom) || (update->eflag_global != invoked_peratom))
error->all(FLERR,"Energy was not tallied on needed timestep");
// collect contributions from ghost atoms
if (force->newton_pair) {
comm->reverse_comm_compute(this);
const int nall = atom->nlocal + atom->nghost;
for (int i = atom->nlocal; i < nall; ++i)
for (int j = 0; j < size_peratom_cols; ++j)
fatom[i][j] = 0.0;
}
}
/* ----------------------------------------------------------------------
memory usage of local atom-based array
------------------------------------------------------------------------- */
double ComputeForceTally::memory_usage()
{
double bytes = nmax*size_peratom_cols * sizeof(double);
return bytes;
}
Event Timeline
Log In to Comment