1 /* ----------------------------------------------------------------------
2 This is the
3
4 ██╗ ██╗ ██████╗ ██████╗ ██████╗ ██╗ ██╗████████╗███████╗
5 ██║ ██║██╔════╝ ██╔════╝ ██╔════╝ ██║ ██║╚══██╔══╝██╔════╝
6 ██║ ██║██║ ███╗██║ ███╗██║ ███╗███████║ ██║ ███████╗
7 ██║ ██║██║ ██║██║ ██║██║ ██║██╔══██║ ██║ ╚════██║
8 ███████╗██║╚██████╔╝╚██████╔╝╚██████╔╝██║ ██║ ██║ ███████║
9 ╚══════╝╚═╝ ╚═════╝ ╚═════╝ ╚═════╝ ╚═╝ ╚═╝ ╚═╝ ╚══════╝®
10
11 DEM simulation engine, released by
12 DCS Computing Gmbh, Linz, Austria
13 http://www.dcs-computing.com, office@dcs-computing.com
14
15 LIGGGHTS® is part of CFDEM®project:
16 http://www.liggghts.com | http://www.cfdem.com
17
18 Core developer and main author:
19 Christoph Kloss, christoph.kloss@dcs-computing.com
20
21 LIGGGHTS® is open-source, distributed under the terms of the GNU Public
22 License, version 2 or later. It is distributed in the hope that it will
23 be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
24 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. You should have
25 received a copy of the GNU General Public License along with LIGGGHTS®.
26 If not, see http://www.gnu.org/licenses . See also top-level README
27 and LICENSE files.
28
29 LIGGGHTS® and CFDEM® are registered trade marks of DCS Computing GmbH,
30 the producer of the LIGGGHTS® software and the CFDEM®coupling software
31 See http://www.cfdem.com/terms-trademark-policy for details.
32
33 -------------------------------------------------------------------------
34 Contributing author and copyright for this file:
35 This file is from LAMMPS
36 LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
37 http://lammps.sandia.gov, Sandia National Laboratories
38 Steve Plimpton, sjplimp@sandia.gov
39
40 Copyright (2003) Sandia Corporation. Under the terms of Contract
41 DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
42 certain rights in this software. This software is distributed under
43 the GNU General Public License.
44 ------------------------------------------------------------------------- */
45
46 #include <string.h>
47 #include <stdlib.h>
48 #include "fix_addforce.h"
49 #include "atom.h"
50 #include "update.h"
51 #include "modify.h"
52 #include "domain.h"
53 #include "region.h"
54 #include "respa.h"
55 #include "input.h"
56 #include "variable.h"
57 #include "memory.h"
58 #include "error.h"
59 #include "force.h"
60
61 using namespace LAMMPS_NS;
62 using namespace FixConst;
63
64 enum{NONE,CONSTANT,EQUAL,ATOM};
65
66 /* ---------------------------------------------------------------------- */
67
FixAddForce(LAMMPS * lmp,int narg,char ** arg)68 FixAddForce::FixAddForce(LAMMPS *lmp, int narg, char **arg) :
69 Fix(lmp, narg, arg)
70 {
71 if (narg < 6) error->all(FLERR,"Illegal fix addforce command");
72
73 scalar_flag = 1;
74 vector_flag = 1;
75 size_vector = 3;
76 global_freq = 1;
77 extscalar = 1;
78 extvector = 1;
79
80 xstr = ystr = zstr = NULL;
81
82 if (strstr(arg[3],"v_") == arg[3]) {
83 int n = strlen(&arg[3][2]) + 1;
84 xstr = new char[n];
85 strcpy(xstr,&arg[3][2]);
86 } else {
87 xvalue = force->numeric(FLERR,arg[3]);
88 xstyle = CONSTANT;
89 }
90 if (strstr(arg[4],"v_") == arg[4]) {
91 int n = strlen(&arg[4][2]) + 1;
92 ystr = new char[n];
93 strcpy(ystr,&arg[4][2]);
94 } else {
95 yvalue = force->numeric(FLERR,arg[4]);
96 ystyle = CONSTANT;
97 }
98 if (strstr(arg[5],"v_") == arg[5]) {
99 int n = strlen(&arg[5][2]) + 1;
100 zstr = new char[n];
101 strcpy(zstr,&arg[5][2]);
102 } else {
103 zvalue = force->numeric(FLERR,arg[5]);
104 zstyle = CONSTANT;
105 }
106
107 // optional args
108
109 iregion = -1;
110 idregion = NULL;
111 estr = NULL;
112
113 int iarg = 6;
114 while (iarg < narg) {
115 if (strcmp(arg[iarg],"region") == 0) {
116 if (iarg+2 > narg) error->all(FLERR,"Illegal fix addforce command");
117 iregion = domain->find_region(arg[iarg+1]);
118 if (iregion == -1)
119 error->all(FLERR,"Region ID for fix addforce does not exist");
120 int n = strlen(arg[iarg+1]) + 1;
121 idregion = new char[n];
122 strcpy(idregion,arg[iarg+1]);
123 iarg += 2;
124 } else if (strcmp(arg[iarg],"energy") == 0) {
125 if (iarg+2 > narg) error->all(FLERR,"Illegal fix addforce command");
126 if (strstr(arg[iarg+1],"v_") == arg[iarg+1]) {
127 int n = strlen(&arg[iarg+1][2]) + 1;
128 estr = new char[n];
129 strcpy(estr,&arg[iarg+1][2]);
130 } else error->all(FLERR,"Illegal fix addforce command");
131 iarg += 2;
132 } else error->all(FLERR,"Illegal fix addforce command");
133 }
134
135 force_flag = 0;
136 foriginal[0] = foriginal[1] = foriginal[2] = foriginal[3] = 0.0;
137
138 maxatom = 0;
139 sforce = NULL;
140 }
141
142 /* ---------------------------------------------------------------------- */
143
~FixAddForce()144 FixAddForce::~FixAddForce()
145 {
146 delete [] xstr;
147 delete [] ystr;
148 delete [] zstr;
149 delete [] estr;
150 delete [] idregion;
151 memory->destroy(sforce);
152 }
153
154 /* ---------------------------------------------------------------------- */
155
setmask()156 int FixAddForce::setmask()
157 {
158 int mask = 0;
159 mask |= POST_FORCE;
160 mask |= THERMO_ENERGY;
161 mask |= POST_FORCE_RESPA;
162 mask |= MIN_POST_FORCE;
163 return mask;
164 }
165
166 /* ---------------------------------------------------------------------- */
167
init()168 void FixAddForce::init()
169 {
170 // check variables
171
172 if (xstr) {
173 xvar = input->variable->find(xstr);
174 if (xvar < 0)
175 error->all(FLERR,"Variable name for fix addforce does not exist");
176 if (input->variable->equalstyle(xvar)) xstyle = EQUAL;
177 else if (input->variable->atomstyle(xvar)) xstyle = ATOM;
178 else error->all(FLERR,"Variable for fix addforce is invalid style");
179 }
180 if (ystr) {
181 yvar = input->variable->find(ystr);
182 if (yvar < 0)
183 error->all(FLERR,"Variable name for fix addforce does not exist");
184 if (input->variable->equalstyle(yvar)) ystyle = EQUAL;
185 else if (input->variable->atomstyle(yvar)) ystyle = ATOM;
186 else error->all(FLERR,"Variable for fix addforce is invalid style");
187 }
188 if (zstr) {
189 zvar = input->variable->find(zstr);
190 if (zvar < 0)
191 error->all(FLERR,"Variable name for fix addforce does not exist");
192 if (input->variable->equalstyle(zvar)) zstyle = EQUAL;
193 else if (input->variable->atomstyle(zvar)) zstyle = ATOM;
194 else error->all(FLERR,"Variable for fix addforce is invalid style");
195 }
196 if (estr) {
197 evar = input->variable->find(estr);
198 if (evar < 0)
199 error->all(FLERR,"Variable name for fix addforce does not exist");
200 if (input->variable->atomstyle(evar)) estyle = ATOM;
201 else error->all(FLERR,"Variable for fix addforce is invalid style");
202 } else estyle = NONE;
203
204 // set index and check validity of region
205
206 if (iregion >= 0) {
207 iregion = domain->find_region(idregion);
208 if (iregion == -1)
209 error->all(FLERR,"Region ID for fix addforce does not exist");
210 }
211
212 if (xstyle == ATOM || ystyle == ATOM || zstyle == ATOM)
213 varflag = ATOM;
214 else if (xstyle == EQUAL || ystyle == EQUAL || zstyle == EQUAL)
215 varflag = EQUAL;
216 else varflag = CONSTANT;
217
218 if (varflag == CONSTANT && estyle != NONE)
219 error->all(FLERR,"Cannot use variable energy with "
220 "constant force in fix addforce");
221 if ((varflag == EQUAL || varflag == ATOM) &&
222 update->whichflag == 2 && estyle == NONE)
223 error->all(FLERR,"Must use variable energy with fix addforce");
224
225 if (strstr(update->integrate_style,"respa"))
226 nlevels_respa = ((Respa *) update->integrate)->nlevels;
227
228 // error checks on coarsegraining
229 if(force->cg_active())
230 error->cg(FLERR,this->style);
231 }
232
233 /* ---------------------------------------------------------------------- */
234
setup(int vflag)235 void FixAddForce::setup(int vflag)
236 {
237 if (strstr(update->integrate_style,"verlet"))
238 post_force(vflag);
239 else {
240 ((Respa *) update->integrate)->copy_flevel_f(nlevels_respa-1);
241 post_force_respa(vflag,nlevels_respa-1,0);
242 ((Respa *) update->integrate)->copy_f_flevel(nlevels_respa-1);
243 }
244 }
245
246 /* ---------------------------------------------------------------------- */
247
min_setup(int vflag)248 void FixAddForce::min_setup(int vflag)
249 {
250 post_force(vflag);
251 }
252
253 /* ---------------------------------------------------------------------- */
254
post_force(int vflag)255 void FixAddForce::post_force(int vflag)
256 {
257 double **x = atom->x;
258 double **f = atom->f;
259 int *mask = atom->mask;
260 tagint *image = atom->image;
261 int nlocal = atom->nlocal;
262
263 // reallocate sforce array if necessary
264
265 if ((varflag == ATOM || estyle == ATOM) && nlocal > maxatom) {
266 maxatom = atom->nmax;
267 memory->destroy(sforce);
268 memory->create(sforce,maxatom,4,"addforce:sforce");
269 }
270
271 // foriginal[0] = "potential energy" for added force
272 // foriginal[123] = force on atoms before extra force added
273
274 foriginal[0] = foriginal[1] = foriginal[2] = foriginal[3] = 0.0;
275 force_flag = 0;
276
277 // constant force
278 // potential energy = - x dot f in unwrapped coords
279
280 if (varflag == CONSTANT) {
281 double unwrap[3];
282 for (int i = 0; i < nlocal; i++)
283 if (mask[i] & groupbit) {
284 if (iregion >= 0 &&
285 !domain->regions[iregion]->match(x[i][0],x[i][1],x[i][2]))
286 continue;
287
288 domain->unmap(x[i],image[i],unwrap);
289 foriginal[0] -= xvalue*unwrap[0] + yvalue*unwrap[1] + zvalue*unwrap[2];
290 foriginal[1] += f[i][0];
291 foriginal[2] += f[i][1];
292 foriginal[3] += f[i][2];
293 f[i][0] += xvalue;
294 f[i][1] += yvalue;
295 f[i][2] += zvalue;
296 }
297
298 // variable force, wrap with clear/add
299 // potential energy = evar if defined, else 0.0
300 // wrap with clear/add
301
302 } else {
303
304 modify->clearstep_compute();
305
306 if (xstyle == EQUAL) xvalue = input->variable->compute_equal(xvar);
307 else if (xstyle == ATOM && sforce)
308 input->variable->compute_atom(xvar,igroup,&sforce[0][0],4,0);
309 if (ystyle == EQUAL) yvalue = input->variable->compute_equal(yvar);
310 else if (ystyle == ATOM && sforce)
311 input->variable->compute_atom(yvar,igroup,&sforce[0][1],4,0);
312 if (zstyle == EQUAL) zvalue = input->variable->compute_equal(zvar);
313 else if (zstyle == ATOM && sforce)
314 input->variable->compute_atom(zvar,igroup,&sforce[0][2],4,0);
315 if (estyle == ATOM && sforce)
316 input->variable->compute_atom(evar,igroup,&sforce[0][3],4,0);
317
318 modify->addstep_compute(update->ntimestep + 1);
319
320 for (int i = 0; i < nlocal; i++)
321 if (mask[i] & groupbit) {
322 if (iregion >= 0 &&
323 !domain->regions[iregion]->match(x[i][0],x[i][1],x[i][2]))
324 continue;
325
326 if (estyle == ATOM) foriginal[0] += sforce[i][3];
327 foriginal[1] += f[i][0];
328 foriginal[2] += f[i][1];
329 foriginal[3] += f[i][2];
330 if (xstyle == ATOM) f[i][0] += sforce[i][0];
331 else if (xstyle) f[i][0] += xvalue;
332 if (ystyle == ATOM) f[i][1] += sforce[i][1];
333 else if (ystyle) f[i][1] += yvalue;
334 if (zstyle == ATOM) f[i][2] += sforce[i][2];
335 else if (zstyle) f[i][2] += zvalue;
336 }
337 }
338 }
339
340 /* ---------------------------------------------------------------------- */
341
post_force_respa(int vflag,int ilevel,int iloop)342 void FixAddForce::post_force_respa(int vflag, int ilevel, int iloop)
343 {
344 if (ilevel == nlevels_respa-1) post_force(vflag);
345 }
346
347 /* ---------------------------------------------------------------------- */
348
min_post_force(int vflag)349 void FixAddForce::min_post_force(int vflag)
350 {
351 post_force(vflag);
352 }
353
354 /* ----------------------------------------------------------------------
355 potential energy of added force
356 ------------------------------------------------------------------------- */
357
compute_scalar()358 double FixAddForce::compute_scalar()
359 {
360 // only sum across procs one time
361
362 if (force_flag == 0) {
363 MPI_Allreduce(foriginal,foriginal_all,4,MPI_DOUBLE,MPI_SUM,world);
364 force_flag = 1;
365 }
366 return foriginal_all[0];
367 }
368
369 /* ----------------------------------------------------------------------
370 return components of total force on fix group before force was changed
371 ------------------------------------------------------------------------- */
372
compute_vector(int n)373 double FixAddForce::compute_vector(int n)
374 {
375 // only sum across procs one time
376
377 if (force_flag == 0) {
378 MPI_Allreduce(foriginal,foriginal_all,4,MPI_DOUBLE,MPI_SUM,world);
379 force_flag = 1;
380 }
381 return foriginal_all[n+1];
382 }
383
384 /* ----------------------------------------------------------------------
385 memory usage of local atom-based array
386 ------------------------------------------------------------------------- */
387
memory_usage()388 double FixAddForce::memory_usage()
389 {
390 double bytes = 0.0;
391 if (varflag == ATOM) bytes = atom->nmax*4 * sizeof(double);
392 return bytes;
393 }
394