lmp.extract_compute

Hi,

I am using 'lmp.extract_compute' in the python. This function could give the right value belong to compute class, but the return value is not ordered by ID. So I checked the library.cpp. I modify the cpp like the function 'data = lmp.gather_atoms(name,type,count)' which could return the value ordered by ID. But I failed. I will appreciate if anyone could help me.

The original cpp shows as follows:

void *lammps_extract_compute(void *ptr, char *id, int style, int type)
{
LAMMPS *lmp = (LAMMPS *) ptr;

int icompute = lmp->modify->find_compute(id);
if (icompute < 0) return NULL;
Compute *compute = lmp->modify->compute[icompute];

if (style == 1) {
if (!compute->peratom_flag) return NULL;
if (type == 1) {
if (compute->invoked_peratom != lmp->update->ntimestep)
compute->compute_peratom();
return (void *) compute->vector_atom;
}
if (type == 2) {
if (compute->invoked_peratom != lmp->update->ntimestep)
compute->compute_peratom();
return (void *) compute->array_atom;
}
}

return NULL;
}

And the cpp modified by me is as follows:

void *lammps_extract_compute(void *ptr, char *id, int style, int type, void **data)
{
LAMMPS *lmp = (LAMMPS *) ptr;
int icompute = lmp->modify->find_compute(id);
if (icompute < 0) return NULL;
Compute *compute = lmp->modify->compute[icompute];
int natoms = static_cast (lmp->atom->natoms);
int i,j,offset;
if (style == 1) {
if (!compute->peratom_flag) return NULL;
if (type == 1) {
if (compute->invoked_peratom != lmp->update->ntimestep)
compute->compute_peratom();
return (void *) compute->vector_atom;
}
if (type == 2) {
double **array = NULL;
double *copy;
if (compute->invoked_peratom != lmp->update->ntimestep)
compute->compute_peratom();
array=compute->array_atom;
// void *vptr =compute->array_atom;
// array= (double **) vptr;
//***********
lmp->memory->create(copy,6*natoms,"lib/extract:copy");
for (i = 0; i < 6*natoms; i++) copy[i] = 0.0;
int *tag = lmp->atom->tag; //tag is atom id
int nlocal = lmp->atom->nlocal;
for (i = 0; i < nlocal; i++) {
offset = 6*(tag[i]-1);
for (j = 0; j < 6; j++)
copy[offset++] = array[i][j];
}
MPI_Allreduce(copy,data,6*natoms,MPI_DOUBLE,MPI_SUM,lmp->world);
lmp->memory->destroy(copy);
return (void **) data;
}
}