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

360 lines
10 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_setforce.h"
#include "atom.h"
#include "domain.h"
#include "error.h"
#include "input.h"
#include "memory.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, ATOM };
/* ---------------------------------------------------------------------- */
FixSetForce::FixSetForce(LAMMPS *lmp, int narg, char **arg) :
Fix(lmp, narg, arg), xstr(nullptr), ystr(nullptr), zstr(nullptr), idregion(nullptr),
region(nullptr), sforce(nullptr)
{
if (narg < 6) utils::missing_cmd_args(FLERR, "fix setforce", error);
dynamic_group_allow = 1;
vector_flag = 1;
size_vector = 3;
global_freq = 1;
extvector = 1;
respa_level_support = 1;
ilevel_respa = nlevels_respa = 0;
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) utils::missing_cmd_args(FLERR, "fix setforce region", error);
region = domain->get_region_by_id(arg[iarg + 1]);
if (!region) error->all(FLERR, "Region {} for fix setforce does not exist", arg[iarg + 1]);
idregion = utils::strdup(arg[iarg + 1]);
iarg += 2;
} else
error->all(FLERR, "Unknown fix setforce keyword: {}", arg[iarg]);
}
force_flag = 0;
foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
maxatom = 1;
memory->create(sforce, maxatom, 3, "setforce:sforce");
}
/* ---------------------------------------------------------------------- */
FixSetForce::~FixSetForce()
{
if (copymode) return;
delete[] xstr;
delete[] ystr;
delete[] zstr;
delete[] idregion;
memory->destroy(sforce);
}
/* ---------------------------------------------------------------------- */
int FixSetForce::setmask()
{
int mask = 0;
mask |= POST_FORCE;
mask |= POST_FORCE_RESPA;
mask |= MIN_POST_FORCE;
return mask;
}
/* ---------------------------------------------------------------------- */
void FixSetForce::init()
{
// check variables
if (xstr) {
xvar = input->variable->find(xstr);
if (xvar < 0) error->all(FLERR, "Variable {} for fix setforce does not exist", xstr);
if (input->variable->equalstyle(xvar))
xstyle = EQUAL;
else if (input->variable->atomstyle(xvar))
xstyle = ATOM;
else
error->all(FLERR, "Variable {} for fix setforce is invalid style", xstr);
}
if (ystr) {
yvar = input->variable->find(ystr);
if (yvar < 0) error->all(FLERR, "Variable {} for fix setforce does not exist", ystr);
if (input->variable->equalstyle(yvar))
ystyle = EQUAL;
else if (input->variable->atomstyle(yvar))
ystyle = ATOM;
else
error->all(FLERR, "Variable {} for fix setforce is invalid style", ystr);
}
if (zstr) {
zvar = input->variable->find(zstr);
if (zvar < 0) error->all(FLERR, "Variable {} for fix setforce does not exist", zstr);
if (input->variable->equalstyle(zvar))
zstyle = EQUAL;
else if (input->variable->atomstyle(zvar))
zstyle = ATOM;
else
error->all(FLERR, "Variable {} for fix setforce is invalid style", zstr);
}
// set index and check validity of region
if (idregion) {
region = domain->get_region_by_id(idregion);
if (!region) error->all(FLERR, "Region {} for fix setforce does not exist", idregion);
}
if (xstyle == ATOM || ystyle == ATOM || zstyle == ATOM)
varflag = ATOM;
else 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;
}
// cannot use non-zero forces for a minimization since no energy is integrated
// use fix addforce instead
int flag = 0;
if (update->whichflag == 2) {
if (xstyle == EQUAL || xstyle == ATOM) flag = 1;
if (ystyle == EQUAL || ystyle == ATOM) flag = 1;
if (zstyle == EQUAL || zstyle == ATOM) flag = 1;
if (xstyle == CONSTANT && xvalue != 0.0) flag = 1;
if (ystyle == CONSTANT && yvalue != 0.0) flag = 1;
if (zstyle == CONSTANT && zvalue != 0.0) flag = 1;
}
if (flag) error->all(FLERR, "Cannot use non-zero forces in an energy minimization");
}
/* ---------------------------------------------------------------------- */
void FixSetForce::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 FixSetForce::min_setup(int vflag)
{
post_force(vflag);
}
/* ---------------------------------------------------------------------- */
void FixSetForce::post_force(int /*vflag*/)
{
double **x = atom->x;
double **f = atom->f;
int *mask = atom->mask;
int nlocal = atom->nlocal;
// update region if necessary
if (region) region->prematch();
// reallocate sforce array if necessary
if (varflag == ATOM && atom->nmax > maxatom) {
maxatom = atom->nmax;
memory->destroy(sforce);
memory->create(sforce, maxatom, 3, "setforce:sforce");
}
foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
force_flag = 0;
if (varflag == CONSTANT) {
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];
if (xstyle) f[i][0] = xvalue;
if (ystyle) f[i][1] = yvalue;
if (zstyle) f[i][2] = zvalue;
}
// variable force, wrap with clear/add
} else {
modify->clearstep_compute();
if (xstyle == EQUAL)
xvalue = input->variable->compute_equal(xvar);
else if (xstyle == ATOM)
input->variable->compute_atom(xvar, igroup, &sforce[0][0], 3, 0);
if (ystyle == EQUAL)
yvalue = input->variable->compute_equal(yvar);
else if (ystyle == ATOM)
input->variable->compute_atom(yvar, igroup, &sforce[0][1], 3, 0);
if (zstyle == EQUAL)
zvalue = input->variable->compute_equal(zvar);
else if (zstyle == ATOM)
input->variable->compute_atom(zvar, igroup, &sforce[0][2], 3, 0);
modify->addstep_compute(update->ntimestep + 1);
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];
if (xstyle == ATOM)
f[i][0] = sforce[i][0];
else if (xstyle)
f[i][0] = xvalue;
if (ystyle == ATOM)
f[i][1] = sforce[i][1];
else if (ystyle)
f[i][1] = yvalue;
if (zstyle == ATOM)
f[i][2] = sforce[i][2];
else if (zstyle)
f[i][2] = zvalue;
}
}
}
/* ---------------------------------------------------------------------- */
void FixSetForce::post_force_respa(int vflag, int ilevel, int /*iloop*/)
{
// set force to desired value on requested level, 0.0 on other levels
if (ilevel == 0) foriginal_saved[0] = foriginal_saved[1] = foriginal_saved[2] = 0.0;
if (ilevel == ilevel_respa) {
post_force(vflag);
foriginal[0] += foriginal_saved[0];
foriginal[1] += foriginal_saved[1];
foriginal[2] += foriginal_saved[2];
} else {
if (region) region->prematch();
double **x = atom->x;
double **f = atom->f;
int *mask = atom->mask;
int nlocal = atom->nlocal;
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_saved[0] += f[i][0];
foriginal_saved[1] += f[i][1];
foriginal_saved[2] += f[i][2];
if (xstyle) f[i][0] = 0.0;
if (ystyle) f[i][1] = 0.0;
if (zstyle) f[i][2] = 0.0;
}
}
}
/* ---------------------------------------------------------------------- */
void FixSetForce::min_post_force(int vflag)
{
post_force(vflag);
}
/* ----------------------------------------------------------------------
return components of total force on fix group before force was changed
------------------------------------------------------------------------- */
double FixSetForce::compute_vector(int n)
{
// only sum across procs one time
if (force_flag == 0) {
MPI_Allreduce(foriginal, foriginal_all, 3, MPI_DOUBLE, MPI_SUM, world);
force_flag = 1;
}
return foriginal_all[n];
}
/* ----------------------------------------------------------------------
memory usage of local atom-based array
------------------------------------------------------------------------- */
double FixSetForce::memory_usage()
{
double bytes = 0.0;
if (varflag == ATOM) bytes = maxatom * 3 * sizeof(double);
return bytes;
}