/*************************************************************************
* This function finds a matching using the HEM heuristic
**************************************************************************/
void Match_HEM(CtrlType *ctrl, GraphType *graph)
{
int i, ii, j, k, nvtxs, cnvtxs, maxidx, dim;
idxtype *xadj, *vwgt, *adjncy;
idxtype *match, *cmap, *perm, *tperm;
realtype curwgt, maxwgt;
realtype *vvol, *vsurf, *adjwgt, *adjwgtsum;
dim = ctrl->dim;
nvtxs = graph->nvtxs;
xadj = graph->xadj;
vwgt = graph->vwgt;
vvol = graph->vvol;
vsurf = graph->vsurf;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
adjwgtsum = graph->adjwgtsum;
cmap = graph->cmap = idxsmalloc(nvtxs, -1, "cmap");
match = idxsmalloc(nvtxs, -1, "match");
perm = idxmalloc(nvtxs, "perm");
tperm = idxmalloc(nvtxs, "tperm");
RandomPermute(nvtxs, tperm, 1);
BucketSortKeysInc(nvtxs, vwgt[iamax(nvtxs, vwgt)], vwgt, tperm, perm);
/* RandomPermute(nvtxs, perm, 1); */
cnvtxs = 0;
/* Compute a heavy-edge style matching giving preferance to small vertices */
for (ii=0; ii<nvtxs; ii++) {
i = perm[ii];
if (match[i] == UNMATCHED) {
maxidx = i;
maxwgt = 0.0;
/* Find a heavy-edge matching, subject to maxvwgt constraints */
for (j=xadj[i]; j<xadj[i+1]; j++) {
k = adjncy[j];
curwgt = 1.0/ARATIO2(dim, vsurf[i]+vsurf[k]+adjwgtsum[i]+adjwgtsum[k]-
2.0*adjwgt[j], vvol[i]+vvol[k]);
if (match[k] == UNMATCHED && vwgt[i]+vwgt[k] <= ctrl->maxsize &&
curwgt > maxwgt) {
maxwgt = curwgt;
maxidx = k;
}
}
cmap[i] = cmap[maxidx] = cnvtxs++;
match[i] = maxidx;
match[maxidx] = i;
}
}
CreateCoarseGraph(graph, cnvtxs, match, perm);
IMfree((void**)&tperm, &perm, &match, LTERM);
}
void
Math_iamax(void *fp)
{
F_Math_iamax *f;
f = fp;
*f->ret = iamax(f->x->len, (double*)(f->x->data));
}
/*************************************************************************
* This function partitions a finite element mesh by partitioning its nodal
* graph using KMETIS and then assigning elements in a load balanced fashion.
**************************************************************************/
void METIS_PartMeshNodal(int *ne, int *nn, idxtype *elmnts, int *etype, int *numflag,
int *nparts, int *edgecut, idxtype *epart, idxtype *npart)
{
int i, j, k, me;
idxtype *xadj, *adjncy, *pwgts;
int options[10], pnumflag=0, wgtflag=0;
int nnbrs, nbrind[200], nbrwgt[200], maxpwgt;
int esize, esizes[] = {-1, 3, 4, 8, 4};
esize = esizes[*etype];
if (*numflag == 1)
ChangeMesh2CNumbering((*ne)*esize, elmnts);
xadj = idxmalloc(*nn+1, "METIS_MESHPARTNODAL: xadj");
adjncy = idxmalloc(20*(*nn), "METIS_MESHPARTNODAL: adjncy");
METIS_MeshToNodal(ne, nn, elmnts, etype, &pnumflag, xadj, adjncy);
adjncy = realloc(adjncy, xadj[*nn]*sizeof(idxtype));
options[0] = 0;
METIS_PartGraphKway(nn, xadj, adjncy, NULL, NULL, &wgtflag, &pnumflag, nparts, options, edgecut, npart);
/* OK, now compute an element partition based on the nodal partition npart */
idxset(*ne, -1, epart);
pwgts = idxsmalloc(*nparts, 0, "METIS_MESHPARTNODAL: pwgts");
for (i=0; i<*ne; i++) {
me = npart[elmnts[i*esize]];
for (j=1; j<esize; j++) {
if (npart[elmnts[i*esize+j]] != me)
break;
}
if (j == esize) {
epart[i] = me;
pwgts[me]++;
}
}
maxpwgt = 1.03*(*ne)/(*nparts);
for (i=0; i<*ne; i++) {
if (epart[i] == -1) { /* Assign the boundary element */
nnbrs = 0;
for (j=0; j<esize; j++) {
me = npart[elmnts[i*esize+j]];
for (k=0; k<nnbrs; k++) {
if (nbrind[k] == me) {
nbrwgt[k]++;
break;
}
}
if (k == nnbrs) {
nbrind[nnbrs] = me;
nbrwgt[nnbrs++] = 1;
}
}
/* Try to assign it first to the domain with most things in common */
j = iamax(nnbrs, nbrwgt);
if (pwgts[nbrind[j]] < maxpwgt) {
epart[i] = nbrind[j];
}
else {
/* If that fails, assign it to a light domain */
for (j=0; j<nnbrs; j++) {
if (pwgts[nbrind[j]] < maxpwgt) {
epart[i] = nbrind[j];
break;
}
}
if (j == nnbrs)
epart[i] = nbrind[iamax(nnbrs, nbrwgt)];
}
pwgts[epart[i]]++;
}
}
if (*numflag == 1)
ChangeMesh2FNumbering2((*ne)*esize, elmnts, *ne, *nn, epart, npart);
GKfree(&xadj, &adjncy, &pwgts, LTERM);
}
void METIS_PartMeshDual_WV(int *ne, int *nn, idxtype *elmnts, int *etype, int *numflag,
int *nparts, int *edgecut, idxtype *epart, idxtype *npart, idxtype *vwgts)
{
int i, j, k, me;
idxtype *xadj, *adjncy, *pwgts, *nptr, *nind;
int options[10], pnumflag=0, wgtflag=2;
int nnbrs, nbrind[200], nbrwgt[200], maxpwgt;
int esize, esizes[] = {-1, 3, 4, 8, 4};
esize = esizes[*etype];
if (*numflag == 1)
ChangeMesh2CNumbering((*ne)*esize, elmnts);
xadj = idxmalloc(*ne+1, "METIS_MESHPARTNODAL: xadj");
adjncy = idxmalloc(esize*(*ne), "METIS_MESHPARTNODAL: adjncy");
METIS_MeshToDual(ne, nn, elmnts, etype, &pnumflag, xadj, adjncy);
options[0] = 0;
METIS_PartGraphKway(ne, xadj, adjncy, vwgts, NULL, &wgtflag, &pnumflag, nparts, options, edgecut, epart);
/* Construct the node-element list */
nptr = idxsmalloc(*nn+1, 0, "METIS_MESHPARTDUAL: nptr");
for (j=esize*(*ne), i=0; i<j; i++)
nptr[elmnts[i]]++;
MAKECSR(i, *nn, nptr);
nind = idxmalloc(nptr[*nn], "METIS_MESHPARTDUAL: nind");
for (k=i=0; i<(*ne); i++) {
for (j=0; j<esize; j++, k++)
nind[nptr[elmnts[k]]++] = i;
}
for (i=(*nn); i>0; i--)
nptr[i] = nptr[i-1];
nptr[0] = 0;
/* OK, now compute a nodal partition based on the element partition npart */
idxset(*nn, -1, npart);
pwgts = idxsmalloc(*nparts, 0, "METIS_MESHPARTDUAL: pwgts");
for (i=0; i<*nn; i++) {
me = epart[nind[nptr[i]]];
for (j=nptr[i]+1; j<nptr[i+1]; j++) {
if (epart[nind[j]] != me)
break;
}
if (j == nptr[i+1]) {
npart[i] = me;
pwgts[me]++;
}
}
maxpwgt = 1.03*(*nn)/(*nparts);
for (i=0; i<*nn; i++) {
if (npart[i] == -1) { /* Assign the boundary element */
nnbrs = 0;
for (j=nptr[i]; j<nptr[i+1]; j++) {
me = epart[nind[j]];
for (k=0; k<nnbrs; k++) {
if (nbrind[k] == me) {
nbrwgt[k]++;
break;
}
}
if (k == nnbrs) {
nbrind[nnbrs] = me;
nbrwgt[nnbrs++] = 1;
}
}
/* Try to assign it first to the domain with most things in common */
j = iamax(nnbrs, nbrwgt);
if (pwgts[nbrind[j]] < maxpwgt) {
npart[i] = nbrind[j];
}
else {
/* If that fails, assign it to a light domain */
npart[i] = nbrind[0];
for (j=0; j<nnbrs; j++) {
if (pwgts[nbrind[j]] < maxpwgt) {
npart[i] = nbrind[j];
break;
}
}
}
pwgts[npart[i]]++;
}
}
if (*numflag == 1)
ChangeMesh2FNumbering2((*ne)*esize, elmnts, *ne, *nn, epart, npart);
GKfree(&xadj, &adjncy, &pwgts, &nptr, &nind, LTERM);
}
