/***********************************************************************************
* This function is the entry point of the parallel multilevel undirected diffusion
* algorithm. It uses parallel undirected diffusion followed by adaptive k-way
* refinement. This function utilizes local coarsening.
************************************************************************************/
void PARUAMETIS(idxtype *vtxdist, idxtype *xadj, idxtype *vwgt, idxtype *adjncy, idxtype *adjwgt,
idxtype *part, int *options, MPI_Comm comm)
{
int wgtflag, numflag, edgecut, newoptions[5];
newoptions[0] = 1;
newoptions[OPTION_IPART] = options[2];
newoptions[OPTION_FOLDF] = options[1];
newoptions[OPTION_DBGLVL] = options[4];
numflag = options[3];
wgtflag = (vwgt == NULL ? 0 : 2) + (adjwgt == NULL ? 0 : 1);
ParMETIS_RepartLDiffusion(vtxdist, xadj, adjncy, vwgt, adjwgt, &wgtflag, &numflag,
newoptions, &edgecut, part, &comm);
options[0] = edgecut;
}
void CreateFusedElementGraph(CtrlType *ctrl, GraphType *graph, WorkSpaceType *wspace, int *numflag)
{
int i, j, k, l;
int *nparts, ipart, mypart, newpart;
int wgtflag, edgecut, npes, mype, nvtxs, nedges, counter;
int gnfvtxs, nfvtxs, firstfvtx;
int foptions[10];
idxtype *fptr, *find;
idxtype *part, *fpart, *spart, *rpart;
idxtype *vtxdist, *xadj, *adjncy;
idxtype *fvtxdist, *fxadj, *fadjncy;
idxtype *map;
realtype *fadjwgt;
MPI_Comm *comm;
npes = ctrl->npes;
mype = ctrl->mype;
nparts = &(ctrl->nparts);
comm = &(ctrl->comm);
vtxdist = graph->vtxdist;
xadj = graph->xadj;
adjncy = graph->adjncy;
nvtxs = vtxdist[mype+1]-vtxdist[mype];
nedges = xadj[nvtxs];
SetUp(ctrl, graph, wspace);
/* Communicate number of parts found */
fvtxdist = idxmalloc(npes+1, "FusedElementGraph: fvtxdist");
MPI_Allgather((void *)nparts, 1, MPI_INT, (void *)fvtxdist, 1, MPI_INT, *comm);
MAKECSR(i, npes, fvtxdist);
firstfvtx = fvtxdist[mype];
nfvtxs = fvtxdist[mype+1]-fvtxdist[mype];
gnfvtxs = fvtxdist[npes];
ASSERT(ctrl, nfvtxs == *nparts);
part = idxmalloc(nvtxs+graph->nrecv, "FusedElementGraph: part");
idxcopy(nvtxs, graph->where, part);
spart = wspace->indices;
rpart = part + nvtxs;
CommInterfaceData(ctrl, graph, part, spart, rpart);
/* Create a part-to-vertex mapping */
/* map = idxsmalloc(gnfvtxs, -1, "FusedElementGraph: map"); */ /* TOO GENEROUS !! */
/* fptr = idxsmalloc(*nparts+1, 0, "FusedElementGraph: fptr"); */
/* find = idxmalloc(nvtxs, "FusedElementGraph: find"); */
if (gnfvtxs + nvtxs + (*nparts+1) <= wspace->maxcore) {
map = wspace->core;
idxset(gnfvtxs, -1, map);
fptr = map + gnfvtxs;
}
else {
map = idxsmalloc(gnfvtxs, -1, "FusedElementGraph: map");
fptr = wspace->core;
}
idxset((*nparts+1), 0, fptr);
find = fptr + (*nparts+1);
for (i=0; i<nvtxs; i++)
fptr[part[i]-firstfvtx]++;
MAKECSR(i, *nparts, fptr);
for (i=0; i<nvtxs; i++) {
ipart = part[i] - firstfvtx;
find[fptr[ipart]] = i;
fptr[ipart]++;
}
for (ipart=*nparts; ipart>0; ipart--)
fptr[ipart] = fptr[ipart-1];
fptr[0] = 0;
/* Create the fused graph for the local edges */
fxadj = idxsmalloc(nfvtxs+1, 0, "FusedElementGraph: fxadj");
fadjncy = idxmalloc(nedges, "FusedElementGraph: fadjncy");
fadjwgt = realsmalloc(nedges, 0, "FusedElementGraph: fadjwgt");
fxadj[0] = 0;
for (ipart=0; ipart<*nparts; ipart++) {
counter = 0;
mypart = ipart + firstfvtx;
for (l=fptr[ipart]; l<fptr[ipart+1]; l++) {
i = find[l];
for (j=xadj[i]; j<xadj[i+1]; j++) {
k=adjncy[j];
newpart=part[k];
if (newpart != mypart && map[newpart] == -1) { /* edge is not created yet */
map[newpart] = fxadj[ipart]+counter;
fadjncy[fxadj[ipart]+counter] = newpart;
fadjwgt[map[newpart]] = 1; /* alternatively = adjwgt[k] */
counter++;
}
else if (newpart != mypart && map[newpart] != -1) /* edge is already there */
fadjwgt[map[newpart]]++;
}
}
fxadj[ipart+1] = fxadj[ipart] + counter;
for (i=fxadj[ipart]; i<fxadj[ipart+1]; i++)
map[fadjncy[i]] = -1;
}
/* Now change the weights of the interface edges */
ChangeWeights(nfvtxs, fvtxdist, fxadj, fadjncy, fadjwgt, *comm);
/* Repartition the graph using fused elements */
foptions[0] = 1;
foptions[3] = 0;
/* fpart = idxmalloc(nfvtxs, "TestParMetis: fpart"); */
fpart = map; /* it is OK since nfvtxs < gnfvtxs */
wgtflag = 1;
ParMETIS_RepartLDiffusion(fvtxdist, fxadj, fadjncy, NULL, fadjwgt,
&wgtflag, numflag, foptions, &edgecut, fpart, comm);
/* Project the partitioning back to the original graph */
for (ipart=0; ipart<nfvtxs; ipart++) {
ASSERTP(ctrl, fpart[ipart] >= 0 && fpart[ipart] < npes, (ctrl, "%d %d %d\n", ipart , fpart[ipart], npes) );
for (i=fptr[ipart]; i<fptr[ipart+1]; i++)
graph->where[find[i]]=fpart[ipart];
}
if (gnfvtxs + nvtxs + (*nparts+1) > wspace->maxcore)
IMfree((void**)&map, LTERM);
IMfree((void**)&fvtxdist, &fxadj, &fadjncy, &fadjwgt, &part, LTERM);
}
