/*@
MatColoringSetFromOptions - Sets MatColoring options from user parameters
Collective on MatColoring
Input Parameters:
. mc - MatColoring context
Options Database Keys:
+ -mat_coloring_type - the type of coloring algorithm used
. -mat_coloring_maxcolors - the maximum number of relevant colors, all nodes not in a color are in maxcolors+1
. -mat_coloring_distance - compute a distance 1,2,... coloring.
. -mat_coloring_view - print information about the coloring and the produced index sets
Level: beginner
.keywords: Coloring, Matrix
.seealso: MatColoring, MatColoringApply()
@*/
PetscErrorCode MatColoringSetFromOptions(MatColoring mc)
{
PetscBool flg;
MatColoringType deft = MATCOLORINGSL;
char type[256];
PetscErrorCode ierr;
PetscInt dist,maxcolors;
PetscFunctionBegin;
PetscValidHeaderSpecific(mc,MAT_COLORING_CLASSID,1);
ierr = MatColoringGetDistance(mc,&dist);CHKERRQ(ierr);
ierr = MatColoringGetMaxColors(mc,&maxcolors);CHKERRQ(ierr);
if (!MatColoringRegisterAllCalled) {ierr = MatColoringRegisterAll();CHKERRQ(ierr);}
ierr = PetscObjectOptionsBegin((PetscObject)mc);CHKERRQ(ierr);
if (((PetscObject)mc)->type_name) deft = ((PetscObject)mc)->type_name;
ierr = PetscOptionsFList("-mat_coloring_type","The coloring method used","MatColoringSetType",MatColoringList,deft,type,256,&flg);CHKERRQ(ierr);
if (flg) {
ierr = MatColoringSetType(mc,type);CHKERRQ(ierr);
} else if (!((PetscObject)mc)->type_name) {
ierr = MatColoringSetType(mc,deft);CHKERRQ(ierr);
}
ierr = PetscOptionsInt("-mat_coloring_distance","Distance of the coloring","MatColoringSetDistance",dist,&dist,&flg);CHKERRQ(ierr);
if (flg) {ierr = MatColoringSetDistance(mc,dist);CHKERRQ(ierr);}
ierr = PetscOptionsInt("-mat_coloring_maxcolors","Maximum colors returned at the end. 1 returns an independent set","MatColoringSetMaxColors",maxcolors,&maxcolors,&flg);CHKERRQ(ierr);
if (flg) {ierr = MatColoringSetMaxColors(mc,maxcolors);CHKERRQ(ierr);}
if (mc->ops->setfromoptions) {
ierr = (*mc->ops->setfromoptions)(mc);CHKERRQ(ierr);
}
ierr = PetscOptionsBool("-mat_coloring_valid","Check that a valid coloring has been produced","",mc->valid,&mc->valid,NULL);CHKERRQ(ierr);
ierr = PetscOptionsEnum("-mat_coloring_weight_type","Sets the type of vertex weighting used","MatColoringSetWeightType",MatColoringWeightTypes,(PetscEnum)mc->weight_type,(PetscEnum*)&mc->weight_type,NULL);CHKERRQ(ierr);
ierr = PetscObjectProcessOptionsHandlers((PetscObject)mc);CHKERRQ(ierr);
ierr = PetscOptionsEnd();CHKERRQ(ierr);
PetscFunctionReturn(0);
}
static PetscErrorCode GreedyColoringLocalDistanceTwo_Private(MatColoring mc,PetscReal *wts,PetscInt *lperm,ISColoringValue *colors)
{
MC_Greedy *gr = (MC_Greedy *) mc->data;
PetscInt i,j,k,l,s,e,n,nd,nd_global,n_global,idx,ncols,maxcolors,mcol,mcol_global,nd1cols,*mask,masksize,*d1cols,*bad,*badnext,nbad,badsize,ccol,no,cbad;
Mat m = mc->mat, mt;
Mat_MPIAIJ *aij = (Mat_MPIAIJ*)m->data;
Mat md=NULL,mo=NULL;
const PetscInt *md_i,*mo_i,*md_j,*mo_j;
const PetscInt *rmd_i,*rmo_i,*rmd_j,*rmo_j;
PetscBool isMPIAIJ,isSEQAIJ;
PetscInt pcol,*dcolors,*ocolors;
ISColoringValue *badidx;
const PetscInt *cidx;
PetscReal *owts,*colorweights;
PetscInt *oconf,*conf;
PetscSF sf;
PetscLayout layout;
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = MatGetSize(m,&n_global,NULL);CHKERRQ(ierr);
ierr = MatGetOwnershipRange(m,&s,&e);CHKERRQ(ierr);
n=e-s;
nd_global = 0;
/* get the matrix communication structures */
ierr = PetscObjectTypeCompare((PetscObject)m, MATMPIAIJ, &isMPIAIJ); CHKERRQ(ierr);
ierr = PetscObjectTypeCompare((PetscObject)m, MATSEQAIJ, &isSEQAIJ); CHKERRQ(ierr);
if (isMPIAIJ) {
Mat_SeqAIJ *dseq;
Mat_SeqAIJ *oseq;
md=aij->A;
dseq = (Mat_SeqAIJ*)md->data;
mo=aij->B;
oseq = (Mat_SeqAIJ*)mo->data;
md_i = dseq->i;
md_j = dseq->j;
mo_i = oseq->i;
mo_j = oseq->j;
rmd_i = dseq->i;
rmd_j = dseq->j;
rmo_i = oseq->i;
rmo_j = oseq->j;
} else if (isSEQAIJ) {
Mat_SeqAIJ *dseq;
/* no off-processor nodes */
md=m;
dseq = (Mat_SeqAIJ*)md->data;
md_i = dseq->i;
md_j = dseq->j;
mo_i = NULL;
mo_j = NULL;
rmd_i = dseq->i;
rmd_j = dseq->j;
rmo_i = NULL;
rmo_j = NULL;
} else SETERRQ(PetscObjectComm((PetscObject)mc),PETSC_ERR_ARG_WRONG,"Matrix must be AIJ for greedy coloring");
if (!gr->symmetric) {
ierr = MatTranspose(m, MAT_INITIAL_MATRIX, &mt);CHKERRQ(ierr);
if (isSEQAIJ) {
Mat_SeqAIJ *dseq = (Mat_SeqAIJ*) mt->data;
rmd_i = dseq->i;
rmd_j = dseq->j;
rmo_i = NULL;
rmo_j = NULL;
} else SETERRQ(PetscObjectComm((PetscObject) mc), PETSC_ERR_SUP, "Nonsymmetric greedy coloring only works in serial");
}
/* create the vectors and communication structures if necessary */
no=0;
if (mo) {
ierr = VecGetLocalSize(aij->lvec,&no);CHKERRQ(ierr);
ierr = PetscSFCreate(PetscObjectComm((PetscObject)m),&sf);CHKERRQ(ierr);
ierr = MatGetLayouts(m,&layout,NULL);CHKERRQ(ierr);
ierr = PetscSFSetGraphLayout(sf,layout,no,NULL,PETSC_COPY_VALUES,aij->garray);CHKERRQ(ierr);
}
ierr = MatColoringGetMaxColors(mc,&maxcolors);CHKERRQ(ierr);
masksize=n;
nbad=0;
badsize=n;
ierr = PetscMalloc1(masksize,&mask);CHKERRQ(ierr);
ierr = PetscMalloc4(n,&d1cols,n,&dcolors,n,&conf,n,&bad);CHKERRQ(ierr);
ierr = PetscMalloc2(badsize,&badidx,badsize,&badnext);CHKERRQ(ierr);
for(i=0;i<masksize;i++) {
mask[i]=-1;
}
for (i=0;i<n;i++) {
dcolors[i]=maxcolors;
bad[i]=-1;
}
for (i=0;i<badsize;i++) {
badnext[i]=-1;
}
if (mo) {
ierr = PetscMalloc3(no,&owts,no,&oconf,no,&ocolors);CHKERRQ(ierr);
ierr = PetscSFBcastBegin(sf,MPIU_REAL,wts,owts);CHKERRQ(ierr);
ierr = PetscSFBcastEnd(sf,MPIU_REAL,wts,owts);CHKERRQ(ierr);
for (i=0;i<no;i++) {
ocolors[i]=maxcolors;
}
} else { /* Appease overzealous -Wmaybe-initialized */
owts = NULL;
oconf = NULL;
ocolors = NULL;
}
mcol=0;
while (nd_global < n_global) {
nd=n;
/* assign lowest possible color to each local vertex */
mcol_global=0;
ierr = PetscLogEventBegin(MATCOLORING_Local,mc,0,0,0);CHKERRQ(ierr);
for (i=0;i<n;i++) {
idx=lperm[i];
if (dcolors[idx] == maxcolors) {
/* entries in bad */
cbad=bad[idx];
while (cbad>=0) {
ccol=badidx[cbad];
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
cbad=badnext[cbad];
}
/* diagonal distance-one rows */
nd1cols=0;
ncols = rmd_i[idx+1]-rmd_i[idx];
cidx = &(rmd_j[rmd_i[idx]]);
for (j=0;j<ncols;j++) {
d1cols[nd1cols] = cidx[j];
nd1cols++;
ccol=dcolors[cidx[j]];
if (ccol != maxcolors) {
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
}
}
/* off-diagonal distance-one rows */
if (mo) {
ncols = rmo_i[idx+1]-rmo_i[idx];
cidx = &(rmo_j[rmo_i[idx]]);
for (j=0;j<ncols;j++) {
ccol=ocolors[cidx[j]];
if (ccol != maxcolors) {
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
}
}
}
/* diagonal distance-two rows */
for (j=0;j<nd1cols;j++) {
ncols = md_i[d1cols[j]+1]-md_i[d1cols[j]];
cidx = &(md_j[md_i[d1cols[j]]]);
for (l=0;l<ncols;l++) {
ccol=dcolors[cidx[l]];
if (ccol != maxcolors) {
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
}
}
}
/* off-diagonal distance-two rows */
if (mo) {
for (j=0;j<nd1cols;j++) {
ncols = mo_i[d1cols[j]+1]-mo_i[d1cols[j]];
cidx = &(mo_j[mo_i[d1cols[j]]]);
for (l=0;l<ncols;l++) {
ccol=ocolors[cidx[l]];
if (ccol != maxcolors) {
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
}
}
}
}
/* assign this one the lowest color possible by seeing if there's a gap in the sequence of sorted neighbor colors */
for (j=0;j<masksize;j++) {
if (mask[j]!=idx) {
break;
}
}
pcol=j;
if (pcol>maxcolors) pcol=maxcolors;
dcolors[idx]=pcol;
if (pcol>mcol) mcol=pcol;
}
}
ierr = PetscLogEventEnd(MATCOLORING_Local,mc,0,0,0);CHKERRQ(ierr);
if (mo) {
/* transfer neighbor colors */
ierr = PetscSFBcastBegin(sf,MPIU_INT,dcolors,ocolors);CHKERRQ(ierr);
ierr = PetscSFBcastEnd(sf,MPIU_INT,dcolors,ocolors);CHKERRQ(ierr);
/* find the maximum color assigned locally and allocate a mask */
ierr = MPIU_Allreduce(&mcol,&mcol_global,1,MPIU_INT,MPI_MAX,PetscObjectComm((PetscObject)mc));CHKERRQ(ierr);
ierr = PetscMalloc1(mcol_global+1,&colorweights);CHKERRQ(ierr);
/* check for conflicts */
for (i=0;i<n;i++) {
conf[i]=PETSC_FALSE;
}
for (i=0;i<no;i++) {
oconf[i]=PETSC_FALSE;
}
for (i=0;i<n;i++) {
ncols = mo_i[i+1]-mo_i[i];
cidx = &(mo_j[mo_i[i]]);
if (ncols > 0) {
/* fill in the mask */
for (j=0;j<mcol_global+1;j++) {
colorweights[j]=0;
}
colorweights[dcolors[i]]=wts[i];
/* fill in the off-diagonal part of the mask */
for (j=0;j<ncols;j++) {
ccol=ocolors[cidx[j]];
if (ccol < maxcolors) {
if (colorweights[ccol] < owts[cidx[j]]) {
colorweights[ccol] = owts[cidx[j]];
}
}
}
/* fill in the on-diagonal part of the mask */
ncols = md_i[i+1]-md_i[i];
cidx = &(md_j[md_i[i]]);
for (j=0;j<ncols;j++) {
ccol=dcolors[cidx[j]];
if (ccol < maxcolors) {
if (colorweights[ccol] < wts[cidx[j]]) {
colorweights[ccol] = wts[cidx[j]];
}
}
}
/* go back through and set up on and off-diagonal conflict vectors */
ncols = md_i[i+1]-md_i[i];
cidx = &(md_j[md_i[i]]);
for (j=0;j<ncols;j++) {
ccol=dcolors[cidx[j]];
if (ccol < maxcolors) {
if (colorweights[ccol] > wts[cidx[j]]) {
conf[cidx[j]]=PETSC_TRUE;
}
}
}
ncols = mo_i[i+1]-mo_i[i];
cidx = &(mo_j[mo_i[i]]);
for (j=0;j<ncols;j++) {
ccol=ocolors[cidx[j]];
if (ccol < maxcolors) {
if (colorweights[ccol] > owts[cidx[j]]) {
oconf[cidx[j]]=PETSC_TRUE;
}
}
}
}
}
nd_global=0;
ierr = PetscFree(colorweights);CHKERRQ(ierr);
ierr = PetscLogEventBegin(MATCOLORING_Comm,mc,0,0,0);CHKERRQ(ierr);
ierr = PetscSFReduceBegin(sf,MPIU_INT,oconf,conf,MPIU_SUM);CHKERRQ(ierr);
ierr = PetscSFReduceEnd(sf,MPIU_INT,oconf,conf,MPIU_SUM);CHKERRQ(ierr);
ierr = PetscLogEventEnd(MATCOLORING_Comm,mc,0,0,0);CHKERRQ(ierr);
/* go through and unset local colors that have conflicts */
for (i=0;i<n;i++) {
if (conf[i]>0) {
/* push this color onto the bad stack */
badidx[nbad]=dcolors[i];
badnext[nbad]=bad[i];
bad[i]=nbad;
nbad++;
if (nbad>=badsize) {
PetscInt *newbadnext;
ISColoringValue *newbadidx;
ierr = PetscMalloc2(badsize*2,&newbadidx,badsize*2,&newbadnext);CHKERRQ(ierr);
for(k=0;k<2*badsize;k++) {
newbadnext[k]=-1;
}
for(k=0;k<badsize;k++) {
newbadidx[k]=badidx[k];
newbadnext[k]=badnext[k];
}
ierr = PetscFree2(badidx,badnext);CHKERRQ(ierr);
badidx=newbadidx;
badnext=newbadnext;
badsize*=2;
}
dcolors[i] = maxcolors;
nd--;
}
}
}
ierr = MPIU_Allreduce(&nd,&nd_global,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)mc));CHKERRQ(ierr);
}
if (mo) {
ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
ierr = PetscFree3(owts,oconf,ocolors);CHKERRQ(ierr);
}
for (i=0;i<n;i++) {
colors[i]=dcolors[i];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
ierr = PetscFree4(d1cols,dcolors,conf,bad);CHKERRQ(ierr);
ierr = PetscFree2(badidx,badnext);CHKERRQ(ierr);
if (!gr->symmetric) {ierr = MatDestroy(&mt);CHKERRQ(ierr);}
PetscFunctionReturn(0);
}
static PetscErrorCode GreedyColoringLocalDistanceOne_Private(MatColoring mc,PetscReal *wts,PetscInt *lperm,ISColoringValue *colors)
{
PetscInt i,j,k,s,e,n,no,nd,nd_global,n_global,idx,ncols,maxcolors,masksize,ccol,*mask;
PetscErrorCode ierr;
Mat m=mc->mat;
Mat_MPIAIJ *aij = (Mat_MPIAIJ*)m->data;
Mat md=NULL,mo=NULL;
const PetscInt *md_i,*mo_i,*md_j,*mo_j;
PetscBool isMPIAIJ,isSEQAIJ;
ISColoringValue pcol;
const PetscInt *cidx;
PetscInt *lcolors,*ocolors;
PetscReal *owts=NULL;
PetscSF sf;
PetscLayout layout;
PetscFunctionBegin;
ierr = MatGetSize(m,&n_global,NULL);CHKERRQ(ierr);
ierr = MatGetOwnershipRange(m,&s,&e);CHKERRQ(ierr);
n=e-s;
masksize=20;
nd_global = 0;
/* get the matrix communication structures */
ierr = PetscObjectTypeCompare((PetscObject)m, MATMPIAIJ, &isMPIAIJ); CHKERRQ(ierr);
ierr = PetscObjectTypeCompare((PetscObject)m, MATSEQAIJ, &isSEQAIJ); CHKERRQ(ierr);
if (isMPIAIJ) {
/* get the CSR data for on and off diagonal portions of m */
Mat_SeqAIJ *dseq;
Mat_SeqAIJ *oseq;
md=aij->A;
dseq = (Mat_SeqAIJ*)md->data;
mo=aij->B;
oseq = (Mat_SeqAIJ*)mo->data;
md_i = dseq->i;
md_j = dseq->j;
mo_i = oseq->i;
mo_j = oseq->j;
} else if (isSEQAIJ) {
/* get the CSR data for m */
Mat_SeqAIJ *dseq;
/* no off-processor nodes */
md=m;
dseq = (Mat_SeqAIJ*)md->data;
mo=NULL;
no=0;
md_i = dseq->i;
md_j = dseq->j;
mo_i = NULL;
mo_j = NULL;
} else SETERRQ(PetscObjectComm((PetscObject)mc),PETSC_ERR_ARG_WRONG,"Matrix must be AIJ for greedy coloring");
ierr = MatColoringGetMaxColors(mc,&maxcolors);CHKERRQ(ierr);
if (mo) {
ierr = VecGetSize(aij->lvec,&no);CHKERRQ(ierr);
ierr = PetscMalloc2(no,&ocolors,no,&owts);CHKERRQ(ierr);
for(i=0;i<no;i++) {
ocolors[i]=maxcolors;
}
}
ierr = PetscMalloc1(masksize,&mask);CHKERRQ(ierr);
ierr = PetscMalloc1(n,&lcolors);CHKERRQ(ierr);
for(i=0;i<n;i++) {
lcolors[i]=maxcolors;
}
for (i=0;i<masksize;i++) {
mask[i]=-1;
}
if (mo) {
/* transfer neighbor weights */
ierr = PetscSFCreate(PetscObjectComm((PetscObject)m),&sf);CHKERRQ(ierr);
ierr = MatGetLayouts(m,&layout,NULL);CHKERRQ(ierr);
ierr = PetscSFSetGraphLayout(sf,layout,no,NULL,PETSC_COPY_VALUES,aij->garray);CHKERRQ(ierr);
ierr = PetscSFBcastBegin(sf,MPIU_REAL,wts,owts);CHKERRQ(ierr);
ierr = PetscSFBcastEnd(sf,MPIU_REAL,wts,owts);CHKERRQ(ierr);
}
while (nd_global < n_global) {
nd=n;
/* assign lowest possible color to each local vertex */
ierr = PetscLogEventBegin(MATCOLORING_Local,mc,0,0,0);CHKERRQ(ierr);
for (i=0;i<n;i++) {
idx=lperm[i];
if (lcolors[idx] == maxcolors) {
ncols = md_i[idx+1]-md_i[idx];
cidx = &(md_j[md_i[idx]]);
for (j=0;j<ncols;j++) {
if (lcolors[cidx[j]] != maxcolors) {
ccol=lcolors[cidx[j]];
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
}
}
if (mo) {
ncols = mo_i[idx+1]-mo_i[idx];
cidx = &(mo_j[mo_i[idx]]);
for (j=0;j<ncols;j++) {
if (ocolors[cidx[j]] != maxcolors) {
ccol=ocolors[cidx[j]];
if (ccol>=masksize) {
PetscInt *newmask;
ierr = PetscMalloc1(masksize*2,&newmask);CHKERRQ(ierr);
for(k=0;k<2*masksize;k++) {
newmask[k]=-1;
}
for(k=0;k<masksize;k++) {
newmask[k]=mask[k];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
mask=newmask;
masksize*=2;
}
mask[ccol]=idx;
}
}
}
for (j=0;j<masksize;j++) {
if (mask[j]!=idx) {
break;
}
}
pcol=j;
if (pcol>maxcolors)pcol=maxcolors;
lcolors[idx]=pcol;
}
}
ierr = PetscLogEventEnd(MATCOLORING_Local,mc,0,0,0);CHKERRQ(ierr);
if (mo) {
/* transfer neighbor colors */
ierr = PetscLogEventBegin(MATCOLORING_Comm,mc,0,0,0);CHKERRQ(ierr);
ierr = PetscSFBcastBegin(sf,MPIU_INT,lcolors,ocolors);CHKERRQ(ierr);
ierr = PetscSFBcastEnd(sf,MPIU_INT,lcolors,ocolors);CHKERRQ(ierr);
/* check for conflicts -- this is merely checking if any adjacent off-processor rows have the same color and marking the ones that are lower weight locally for changing */
for (i=0;i<n;i++) {
ncols = mo_i[i+1]-mo_i[i];
cidx = &(mo_j[mo_i[i]]);
for (j=0;j<ncols;j++) {
/* in the case of conflicts, the highest weight one stays and the others go */
if ((ocolors[cidx[j]] == lcolors[i]) && (owts[cidx[j]] > wts[i]) && lcolors[i] < maxcolors) {
lcolors[i]=maxcolors;
nd--;
}
}
}
nd_global=0;
}
ierr = MPIU_Allreduce(&nd,&nd_global,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)mc));CHKERRQ(ierr);
}
for (i=0;i<n;i++) {
colors[i] = (ISColoringValue)lcolors[i];
}
ierr = PetscFree(mask);CHKERRQ(ierr);
ierr = PetscFree(lcolors);CHKERRQ(ierr);
if (mo) {
ierr = PetscFree2(ocolors,owts);CHKERRQ(ierr);
ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
