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lammps/src/compute_bond_local.cpp
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compute_bond_local.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.
------------------------------------------------------------------------- */
#include "math.h"
#include "string.h"
#include "compute_bond_local.h"
#include "atom.h"
#include "atom_vec.h"
#include "update.h"
#include "domain.h"
#include "force.h"
#include "bond.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
#define DELTA 10000
enum{DIST,ENG,FORCE};
/* ---------------------------------------------------------------------- */
ComputeBondLocal::ComputeBondLocal(LAMMPS *lmp, int narg, char **arg) :
Compute(lmp, narg, arg)
{
if (narg < 4) error->all(FLERR,"Illegal compute bond/local command");
if (atom->avec->bonds_allow == 0)
error->all(FLERR,"Compute bond/local used when bonds are not allowed");
local_flag = 1;
nvalues = narg - 3;
if (nvalues == 1) size_local_cols = 0;
else size_local_cols = nvalues;
bstyle = new int[nvalues];
nvalues = 0;
for (int iarg = 3; iarg < narg; iarg++) {
if (strcmp(arg[iarg],"dist") == 0) bstyle[nvalues++] = DIST;
else if (strcmp(arg[iarg],"eng") == 0) bstyle[nvalues++] = ENG;
else if (strcmp(arg[iarg],"force") == 0) bstyle[nvalues++] = FORCE;
else error->all(FLERR,"Invalid keyword in compute bond/local command");
}
// set singleflag if need to call bond->single()
singleflag = 0;
for (int i = 0; i < nvalues; i++)
if (bstyle[i] != DIST) singleflag = 1;
nmax = 0;
vector = NULL;
array = NULL;
}
/* ---------------------------------------------------------------------- */
ComputeBondLocal::~ComputeBondLocal()
{
memory->destroy(vector);
memory->destroy(array);
delete [] bstyle;
}
/* ---------------------------------------------------------------------- */
void ComputeBondLocal::init()
{
if (force->bond == NULL)
error->all(FLERR,"No bond style is defined for compute bond/local");
// do initial memory allocation so that memory_usage() is correct
ncount = compute_bonds(0);
if (ncount > nmax) reallocate(ncount);
size_local_rows = ncount;
}
/* ---------------------------------------------------------------------- */
void ComputeBondLocal::compute_local()
{
invoked_local = update->ntimestep;
// count local entries and compute bond info
ncount = compute_bonds(0);
if (ncount > nmax) reallocate(ncount);
size_local_rows = ncount;
ncount = compute_bonds(1);
}
/* ----------------------------------------------------------------------
count bonds and compute bond info on this proc
only count bond once if newton_bond is off
all atoms in interaction must be in group
all atoms in interaction must be known to proc
if bond is deleted (type = 0), do not count
if bond is turned off (type < 0), still count
if flag is set, compute requested info about bond
if bond is turned off (type < 0), energy = 0.0
------------------------------------------------------------------------- */
int ComputeBondLocal::compute_bonds(int flag)
{
int i,m,n,atom1,atom2;
double delx,dely,delz,rsq;
double *dbuf,*ebuf,*fbuf;
double *ptr;
double **x = atom->x;
int *num_bond = atom->num_bond;
int **bond_atom = atom->bond_atom;
int **bond_type = atom->bond_type;
int *tag = atom->tag;
int *mask = atom->mask;
int nlocal = atom->nlocal;
int newton_bond = force->newton_bond;
Bond *bond = force->bond;
double eng,fbond;
m = n = 0;
for (atom1 = 0; atom1 < nlocal; atom1++) {
if (!(mask[atom1] & groupbit)) continue;
for (i = 0; i < num_bond[atom1]; i++) {
atom2 = atom->map(bond_atom[atom1][i]);
if (atom2 < 0 || !(mask[atom2] & groupbit)) continue;
if (newton_bond == 0 && tag[atom1] > tag[atom2]) continue;
if (bond_type[atom1][i] == 0) continue;
if (flag) {
delx = x[atom1][0] - x[atom2][0];
dely = x[atom1][1] - x[atom2][1];
delz = x[atom1][2] - x[atom2][2];
domain->minimum_image(delx,dely,delz);
rsq = delx*delx + dely*dely + delz*delz;
if (singleflag) {
if (bond_type[atom1][i] > 0)
eng = bond->single(bond_type[atom1][i],rsq,atom1,atom2,fbond);
else eng = fbond = 0.0;
}
if (nvalues == 1) ptr = &vector[m];
else ptr = array[m];
for (n = 0; n < nvalues; n++) {
switch (bstyle[n]) {
case DIST:
ptr[n] = sqrt(rsq);
break;
case ENG:
ptr[n] = eng;
break;
case FORCE:
ptr[n] = sqrt(rsq)*fbond;
break;
}
}
}
m++;
}
}
return m;
}
/* ---------------------------------------------------------------------- */
void ComputeBondLocal::reallocate(int n)
{
// grow vector or array and indices array
while (nmax < n) nmax += DELTA;
if (nvalues == 1) {
memory->destroy(vector);
memory->create(vector,nmax,"bond/local:vector");
vector_local = vector;
} else {
memory->destroy(array);
memory->create(array,nmax,nvalues,"bond/local:array");
array_local = array;
}
}
/* ----------------------------------------------------------------------
memory usage of local data
------------------------------------------------------------------------- */
double ComputeBondLocal::memory_usage()
{
double bytes = nmax*nvalues * sizeof(double);
return bytes;
}
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