Files
lammps/src/fix_aveforce.cpp
2022-10-24 11:08:26 -04:00

312 lines
8.8 KiB
C++

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
https://www.lammps.org/, Sandia National Laboratories
LAMMPS development team: developers@lammps.org
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 "fix_aveforce.h"
#include "atom.h"
#include "domain.h"
#include "error.h"
#include "input.h"
#include "modify.h"
#include "region.h"
#include "respa.h"
#include "update.h"
#include "variable.h"
#include <cstring>
using namespace LAMMPS_NS;
using namespace FixConst;
enum { NONE, CONSTANT, EQUAL };
/* ---------------------------------------------------------------------- */
FixAveForce::FixAveForce(LAMMPS *lmp, int narg, char **arg) :
Fix(lmp, narg, arg), xstr(nullptr), ystr(nullptr), zstr(nullptr), idregion(nullptr),
region(nullptr)
{
if (narg < 6) error->all(FLERR, "Illegal fix aveforce command");
dynamic_group_allow = 1;
vector_flag = 1;
size_vector = 3;
global_freq = 1;
extvector = 1;
respa_level_support = 1;
ilevel_respa = nlevels_respa = 0;
xstr = ystr = zstr = nullptr;
if (utils::strmatch(arg[3], "^v_")) {
xstr = utils::strdup(arg[3] + 2);
} else if (strcmp(arg[3], "NULL") == 0) {
xstyle = NONE;
} else {
xvalue = utils::numeric(FLERR, arg[3], false, lmp);
xstyle = CONSTANT;
}
if (utils::strmatch(arg[4], "^v_")) {
ystr = utils::strdup(arg[4] + 2);
} else if (strcmp(arg[4], "NULL") == 0) {
ystyle = NONE;
} else {
yvalue = utils::numeric(FLERR, arg[4], false, lmp);
ystyle = CONSTANT;
}
if (utils::strmatch(arg[5], "^v_")) {
zstr = utils::strdup(arg[5] + 2);
} else if (strcmp(arg[5], "NULL") == 0) {
zstyle = NONE;
} else {
zvalue = utils::numeric(FLERR, arg[5], false, lmp);
zstyle = CONSTANT;
}
// optional args
int iarg = 6;
while (iarg < narg) {
if (strcmp(arg[iarg], "region") == 0) {
if (iarg + 2 > narg) error->all(FLERR, "Illegal fix aveforce command");
region = domain->get_region_by_id(arg[iarg + 1]);
if (!region) error->all(FLERR, "Region {} for fix aveforce does not exist", arg[iarg + 1]);
idregion = utils::strdup(arg[iarg + 1]);
iarg += 2;
} else
error->all(FLERR, "Illegal fix aveforce command");
}
foriginal_all[0] = foriginal_all[1] = foriginal_all[2] = foriginal_all[3] = 0.0;
}
/* ---------------------------------------------------------------------- */
FixAveForce::~FixAveForce()
{
delete[] xstr;
delete[] ystr;
delete[] zstr;
delete[] idregion;
}
/* ---------------------------------------------------------------------- */
int FixAveForce::setmask()
{
int mask = 0;
mask |= POST_FORCE;
mask |= POST_FORCE_RESPA;
mask |= MIN_POST_FORCE;
return mask;
}
/* ---------------------------------------------------------------------- */
void FixAveForce::init()
{
// check variables
if (xstr) {
xvar = input->variable->find(xstr);
if (xvar < 0) error->all(FLERR, "Variable name for fix aveforce does not exist");
if (input->variable->equalstyle(xvar))
xstyle = EQUAL;
else
error->all(FLERR, "Variable for fix aveforce is invalid style");
}
if (ystr) {
yvar = input->variable->find(ystr);
if (yvar < 0) error->all(FLERR, "Variable name for fix aveforce does not exist");
if (input->variable->equalstyle(yvar))
ystyle = EQUAL;
else
error->all(FLERR, "Variable for fix aveforce is invalid style");
}
if (zstr) {
zvar = input->variable->find(zstr);
if (zvar < 0) error->all(FLERR, "Variable name for fix aveforce does not exist");
if (input->variable->equalstyle(zvar))
zstyle = EQUAL;
else
error->all(FLERR, "Variable for fix aveforce is invalid style");
}
// set index and check validity of region
if (idregion) {
region = domain->get_region_by_id(idregion);
if (!region) error->all(FLERR, "Region {} for fix aveforce does not exist", idregion);
}
if (xstyle == EQUAL || ystyle == EQUAL || zstyle == EQUAL)
varflag = EQUAL;
else
varflag = CONSTANT;
if (utils::strmatch(update->integrate_style, "^respa")) {
nlevels_respa = (dynamic_cast<Respa *>(update->integrate))->nlevels;
if (respa_level >= 0)
ilevel_respa = MIN(respa_level, nlevels_respa - 1);
else
ilevel_respa = nlevels_respa - 1;
}
}
/* ---------------------------------------------------------------------- */
void FixAveForce::setup(int vflag)
{
if (utils::strmatch(update->integrate_style, "^verlet"))
post_force(vflag);
else
for (int ilevel = 0; ilevel < nlevels_respa; ilevel++) {
(dynamic_cast<Respa *>(update->integrate))->copy_flevel_f(ilevel);
post_force_respa(vflag, ilevel, 0);
(dynamic_cast<Respa *>(update->integrate))->copy_f_flevel(ilevel);
}
}
/* ---------------------------------------------------------------------- */
void FixAveForce::min_setup(int vflag)
{
post_force(vflag);
}
/* ---------------------------------------------------------------------- */
void FixAveForce::post_force(int /*vflag*/)
{
// update region if necessary
if (region) region->prematch();
// sum forces on participating atoms
double **x = atom->x;
double **f = atom->f;
int *mask = atom->mask;
int nlocal = atom->nlocal;
double foriginal[4];
foriginal[0] = foriginal[1] = foriginal[2] = foriginal[3] = 0.0;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
if (region && !region->match(x[i][0], x[i][1], x[i][2])) continue;
foriginal[0] += f[i][0];
foriginal[1] += f[i][1];
foriginal[2] += f[i][2];
foriginal[3] += 1.0;
}
// average the force on participating atoms
// add in requested amount, computed via variable evaluation if necessary
// wrap variable evaluation with clear/add
MPI_Allreduce(foriginal, foriginal_all, 4, MPI_DOUBLE, MPI_SUM, world);
int ncount = static_cast<int>(foriginal_all[3]);
if (ncount == 0) return;
if (varflag == EQUAL) {
modify->clearstep_compute();
if (xstyle == EQUAL) xvalue = input->variable->compute_equal(xvar);
if (ystyle == EQUAL) yvalue = input->variable->compute_equal(yvar);
if (zstyle == EQUAL) zvalue = input->variable->compute_equal(zvar);
modify->addstep_compute(update->ntimestep + 1);
}
double fave[3];
fave[0] = foriginal_all[0] / ncount + xvalue;
fave[1] = foriginal_all[1] / ncount + yvalue;
fave[2] = foriginal_all[2] / ncount + zvalue;
// set force of all participating atoms to same value
// only for active dimensions
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
if (region && !region->match(x[i][0], x[i][1], x[i][2])) continue;
if (xstyle) f[i][0] = fave[0];
if (ystyle) f[i][1] = fave[1];
if (zstyle) f[i][2] = fave[2];
}
}
/* ---------------------------------------------------------------------- */
void FixAveForce::post_force_respa(int vflag, int ilevel, int /*iloop*/)
{
// ave + extra force on selected RESPA level
// just ave on all other levels
if (ilevel == ilevel_respa) {
post_force(vflag);
} else {
if (region) region->prematch();
double **x = atom->x;
double **f = atom->f;
int *mask = atom->mask;
int nlocal = atom->nlocal;
double foriginal[4];
foriginal[0] = foriginal[1] = foriginal[2] = foriginal[3] = 0.0;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
if (region && !region->match(x[i][0], x[i][1], x[i][2])) continue;
foriginal[0] += f[i][0];
foriginal[1] += f[i][1];
foriginal[2] += f[i][2];
foriginal[3] += 1.0;
}
MPI_Allreduce(foriginal, foriginal_all, 4, MPI_DOUBLE, MPI_SUM, world);
int ncount = static_cast<int>(foriginal_all[3]);
if (ncount == 0) return;
double fave[3];
fave[0] = foriginal_all[0] / ncount;
fave[1] = foriginal_all[1] / ncount;
fave[2] = foriginal_all[2] / ncount;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
if (region && !region->match(x[i][0], x[i][1], x[i][2])) continue;
if (xstyle) f[i][0] = fave[0];
if (ystyle) f[i][1] = fave[1];
if (zstyle) f[i][2] = fave[2];
}
}
}
/* ---------------------------------------------------------------------- */
void FixAveForce::min_post_force(int vflag)
{
post_force(vflag);
}
/* ----------------------------------------------------------------------
return components of total force on fix group before force was changed
------------------------------------------------------------------------- */
double FixAveForce::compute_vector(int n)
{
return foriginal_all[n];
}