1 // clang-format off
2 /* ----------------------------------------------------------------------
3    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
4    https://www.lammps.org/, Sandia National Laboratories
5    Steve Plimpton, sjplimp@sandia.gov
6 
7    Copyright (2003) Sandia Corporation.  Under the terms of Contract
8    DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
9    certain rights in this software.  This software is distributed under
10    the GNU General Public License.
11 
12    See the README file in the top-level LAMMPS directory.
13 ------------------------------------------------------------------------- */
14 
15 #include "compute_torque_chunk.h"
16 
17 #include <cstring>
18 #include "atom.h"
19 #include "update.h"
20 #include "modify.h"
21 #include "compute_chunk_atom.h"
22 #include "domain.h"
23 #include "memory.h"
24 #include "error.h"
25 
26 using namespace LAMMPS_NS;
27 
28 /* ---------------------------------------------------------------------- */
29 
ComputeTorqueChunk(LAMMPS * lmp,int narg,char ** arg)30 ComputeTorqueChunk::ComputeTorqueChunk(LAMMPS *lmp, int narg, char **arg) :
31   Compute(lmp, narg, arg),
32   idchunk(nullptr), massproc(nullptr), masstotal(nullptr), com(nullptr), comall(nullptr), torque(nullptr), torqueall(nullptr)
33 {
34   if (narg != 4) error->all(FLERR,"Illegal compute torque/chunk command");
35 
36   array_flag = 1;
37   size_array_cols = 3;
38   size_array_rows = 0;
39   size_array_rows_variable = 1;
40   extarray = 0;
41 
42   // ID of compute chunk/atom
43 
44   idchunk = utils::strdup(arg[3]);
45 
46   ComputeTorqueChunk::init();
47 
48   // chunk-based data
49 
50   nchunk = 1;
51   maxchunk = 0;
52   allocate();
53 }
54 
55 /* ---------------------------------------------------------------------- */
56 
~ComputeTorqueChunk()57 ComputeTorqueChunk::~ComputeTorqueChunk()
58 {
59   delete [] idchunk;
60   memory->destroy(massproc);
61   memory->destroy(masstotal);
62   memory->destroy(com);
63   memory->destroy(comall);
64   memory->destroy(torque);
65   memory->destroy(torqueall);
66 }
67 
68 /* ---------------------------------------------------------------------- */
69 
init()70 void ComputeTorqueChunk::init()
71 {
72   int icompute = modify->find_compute(idchunk);
73   if (icompute < 0)
74     error->all(FLERR,"Chunk/atom compute does not exist for "
75                "compute torque/chunk");
76   cchunk = (ComputeChunkAtom *) modify->compute[icompute];
77   if (strcmp(cchunk->style,"chunk/atom") != 0)
78     error->all(FLERR,"Compute torque/chunk does not use chunk/atom compute");
79 }
80 
81 /* ---------------------------------------------------------------------- */
82 
compute_array()83 void ComputeTorqueChunk::compute_array()
84 {
85   int i,index;
86   double dx,dy,dz,massone;
87   double unwrap[3];
88 
89   invoked_array = update->ntimestep;
90 
91   // compute chunk/atom assigns atoms to chunk IDs
92   // extract ichunk index vector from compute
93   // ichunk = 1 to Nchunk for included atoms, 0 for excluded atoms
94 
95   nchunk = cchunk->setup_chunks();
96   cchunk->compute_ichunk();
97   int *ichunk = cchunk->ichunk;
98 
99   if (nchunk > maxchunk) allocate();
100   size_array_rows = nchunk;
101 
102   // zero local per-chunk values
103 
104   for (i = 0; i < nchunk; i++) {
105     massproc[i] = 0.0;
106     com[i][0] = com[i][1] = com[i][2] = 0.0;
107     torque[i][0] = torque[i][1] = torque[i][2] = 0.0;
108   }
109 
110   // compute COM for each chunk
111 
112   double **x = atom->x;
113   int *mask = atom->mask;
114   int *type = atom->type;
115   imageint *image = atom->image;
116   double *mass = atom->mass;
117   double *rmass = atom->rmass;
118   int nlocal = atom->nlocal;
119 
120   for (i = 0; i < nlocal; i++)
121     if (mask[i] & groupbit) {
122       index = ichunk[i]-1;
123       if (index < 0) continue;
124       if (rmass) massone = rmass[i];
125       else massone = mass[type[i]];
126       domain->unmap(x[i],image[i],unwrap);
127       massproc[index] += massone;
128       com[index][0] += unwrap[0] * massone;
129       com[index][1] += unwrap[1] * massone;
130       com[index][2] += unwrap[2] * massone;
131     }
132 
133   MPI_Allreduce(massproc,masstotal,nchunk,MPI_DOUBLE,MPI_SUM,world);
134   MPI_Allreduce(&com[0][0],&comall[0][0],3*nchunk,MPI_DOUBLE,MPI_SUM,world);
135 
136   for (i = 0; i < nchunk; i++) {
137     if (masstotal[i] > 0.0) {
138       comall[i][0] /= masstotal[i];
139       comall[i][1] /= masstotal[i];
140       comall[i][2] /= masstotal[i];
141     }
142   }
143 
144   // compute torque on each chunk
145 
146   double **f = atom->f;
147 
148   for (i = 0; i < nlocal; i++)
149     if (mask[i] & groupbit) {
150       index = ichunk[i]-1;
151       if (index < 0) continue;
152       domain->unmap(x[i],image[i],unwrap);
153       dx = unwrap[0] - comall[index][0];
154       dy = unwrap[1] - comall[index][1];
155       dz = unwrap[2] - comall[index][2];
156       torque[index][0] += dy*f[i][2] - dz*f[i][1];
157       torque[index][1] += dz*f[i][0] - dx*f[i][2];
158       torque[index][2] += dx*f[i][1] - dy*f[i][0];
159     }
160 
161   MPI_Allreduce(&torque[0][0],&torqueall[0][0],3*nchunk,
162                 MPI_DOUBLE,MPI_SUM,world);
163 }
164 
165 /* ----------------------------------------------------------------------
166    lock methods: called by fix ave/time
167    these methods insure vector/array size is locked for Nfreq epoch
168      by passing lock info along to compute chunk/atom
169 ------------------------------------------------------------------------- */
170 
171 /* ----------------------------------------------------------------------
172    increment lock counter
173 ------------------------------------------------------------------------- */
174 
lock_enable()175 void ComputeTorqueChunk::lock_enable()
176 {
177   cchunk->lockcount++;
178 }
179 
180 /* ----------------------------------------------------------------------
181    decrement lock counter in compute chunk/atom, it if still exists
182 ------------------------------------------------------------------------- */
183 
lock_disable()184 void ComputeTorqueChunk::lock_disable()
185 {
186   int icompute = modify->find_compute(idchunk);
187   if (icompute >= 0) {
188     cchunk = (ComputeChunkAtom *) modify->compute[icompute];
189     cchunk->lockcount--;
190   }
191 }
192 
193 /* ----------------------------------------------------------------------
194    calculate and return # of chunks = length of vector/array
195 ------------------------------------------------------------------------- */
196 
lock_length()197 int ComputeTorqueChunk::lock_length()
198 {
199   nchunk = cchunk->setup_chunks();
200   return nchunk;
201 }
202 
203 /* ----------------------------------------------------------------------
204    set the lock from startstep to stopstep
205 ------------------------------------------------------------------------- */
206 
lock(Fix * fixptr,bigint startstep,bigint stopstep)207 void ComputeTorqueChunk::lock(Fix *fixptr, bigint startstep, bigint stopstep)
208 {
209   cchunk->lock(fixptr,startstep,stopstep);
210 }
211 
212 /* ----------------------------------------------------------------------
213    unset the lock
214 ------------------------------------------------------------------------- */
215 
unlock(Fix * fixptr)216 void ComputeTorqueChunk::unlock(Fix *fixptr)
217 {
218   cchunk->unlock(fixptr);
219 }
220 
221 /* ----------------------------------------------------------------------
222    free and reallocate per-chunk arrays
223 ------------------------------------------------------------------------- */
224 
allocate()225 void ComputeTorqueChunk::allocate()
226 {
227   memory->destroy(massproc);
228   memory->destroy(masstotal);
229   memory->destroy(com);
230   memory->destroy(comall);
231   memory->destroy(torque);
232   memory->destroy(torqueall);
233   maxchunk = nchunk;
234   memory->create(massproc,maxchunk,"torque/chunk:massproc");
235   memory->create(masstotal,maxchunk,"torque/chunk:masstotal");
236   memory->create(com,maxchunk,3,"torque/chunk:com");
237   memory->create(comall,maxchunk,3,"torque/chunk:comall");
238   memory->create(torque,maxchunk,3,"torque/chunk:torque");
239   memory->create(torqueall,maxchunk,3,"torque/chunk:torqueall");
240   array = torqueall;
241 }
242 
243 /* ----------------------------------------------------------------------
244    memory usage of local data
245 ------------------------------------------------------------------------- */
246 
memory_usage()247 double ComputeTorqueChunk::memory_usage()
248 {
249   double bytes = (bigint) maxchunk * 2 * sizeof(double);
250   bytes += (double) maxchunk * 2*3 * sizeof(double);
251   bytes += (double) maxchunk * 2*3 * sizeof(double);
252   return bytes;
253 }
254