Actual source code: iscoloring.c

petsc-3.6.1 2015-07-22
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  2: #include <petsc/private/isimpl.h>    /*I "petscis.h"  I*/
  3: #include <petscviewer.h>

  5: const char *const ISColoringTypes[] = {"global","ghosted","ISColoringType","IS_COLORING_",0};

  9: PetscErrorCode ISColoringReference(ISColoring coloring)
 10: {
 12:   (coloring)->refct++;
 13:   return(0);
 14: }

 18: PetscErrorCode ISColoringSetType(ISColoring coloring,ISColoringType type)
 19: {
 21:   (coloring)->ctype = type;
 22:   return(0);
 23: }

 27: /*@
 28:    ISColoringDestroy - Destroys a coloring context.

 30:    Collective on ISColoring

 32:    Input Parameter:
 33: .  iscoloring - the coloring context

 35:    Level: advanced

 37: .seealso: ISColoringView(), MatColoring
 38: @*/
 39: PetscErrorCode  ISColoringDestroy(ISColoring *iscoloring)
 40: {
 41:   PetscInt       i;

 45:   if (!*iscoloring) return(0);
 47:   if (--(*iscoloring)->refct > 0) {*iscoloring = 0; return(0);}

 49:   if ((*iscoloring)->is) {
 50:     for (i=0; i<(*iscoloring)->n; i++) {
 51:       ISDestroy(&(*iscoloring)->is[i]);
 52:     }
 53:     PetscFree((*iscoloring)->is);
 54:   }
 55:   if ((*iscoloring)->allocated) {PetscFree((*iscoloring)->colors);}
 56:   PetscCommDestroy(&(*iscoloring)->comm);
 57:   PetscFree((*iscoloring));
 58:   return(0);
 59: }

 63: /*
 64:   ISColoringViewFromOptions - Processes command line options to determine if/how an ISColoring object is to be viewed. 

 66:   Collective on ISColoring

 68:   Input Parameters:
 69: + obj   - the ISColoring object
 70: . prefix - prefix to use for viewing, or NULL to use prefix of 'mat'
 71: - optionname - option to activate viewing

 73:   Level: intermediate

 75:   Developer Note: This cannot use PetscObjectViewFromOptions() because ISColoring is not a PetscObject

 77: */
 78: PetscErrorCode ISColoringViewFromOptions(ISColoring obj,PetscObject bobj,const char optionname[])
 79: {
 80:   PetscErrorCode    ierr;
 81:   PetscViewer       viewer;
 82:   PetscBool         flg;
 83:   PetscViewerFormat format;
 84:   char              *prefix;

 87:   prefix = bobj ? bobj->prefix : NULL;
 88:   PetscOptionsGetViewer(obj->comm,prefix,optionname,&viewer,&format,&flg);
 89:   if (flg) {
 90:     PetscViewerPushFormat(viewer,format);
 91:     ISColoringView(obj,viewer);
 92:     PetscViewerPopFormat(viewer);
 93:     PetscViewerDestroy(&viewer);
 94:   }
 95:   return(0);
 96: }

100: /*@C
101:    ISColoringView - Views a coloring context.

103:    Collective on ISColoring

105:    Input Parameters:
106: +  iscoloring - the coloring context
107: -  viewer - the viewer

109:    Level: advanced

111: .seealso: ISColoringDestroy(), ISColoringGetIS(), MatColoring
112: @*/
113: PetscErrorCode  ISColoringView(ISColoring iscoloring,PetscViewer viewer)
114: {
115:   PetscInt       i;
117:   PetscBool      iascii;
118:   IS             *is;

122:   if (!viewer) {
123:     PetscViewerASCIIGetStdout(iscoloring->comm,&viewer);
124:   }

127:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
128:   if (iascii) {
129:     MPI_Comm    comm;
130:     PetscMPIInt size,rank;

132:     PetscObjectGetComm((PetscObject)viewer,&comm);
133:     MPI_Comm_size(comm,&size);
134:     MPI_Comm_rank(comm,&rank);
135:     PetscViewerASCIIPrintf(viewer,"ISColoring Object: %d MPI processes\n",size);
136:     PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);
137:     PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Number of colors %d\n",rank,iscoloring->n);
138:     PetscViewerFlush(viewer);
139:     PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);
140:   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported for ISColoring",((PetscObject)viewer)->type_name);

142:   ISColoringGetIS(iscoloring,PETSC_IGNORE,&is);
143:   for (i=0; i<iscoloring->n; i++) {
144:     ISView(iscoloring->is[i],viewer);
145:   }
146:   ISColoringRestoreIS(iscoloring,&is);
147:   return(0);
148: }

152: /*@C
153:    ISColoringGetIS - Extracts index sets from the coloring context

155:    Collective on ISColoring

157:    Input Parameter:
158: .  iscoloring - the coloring context

160:    Output Parameters:
161: +  nn - number of index sets in the coloring context
162: -  is - array of index sets

164:    Level: advanced

166: .seealso: ISColoringRestoreIS(), ISColoringView()
167: @*/
168: PetscErrorCode  ISColoringGetIS(ISColoring iscoloring,PetscInt *nn,IS *isis[])
169: {


175:   if (nn) *nn = iscoloring->n;
176:   if (isis) {
177:     if (!iscoloring->is) {
178:       PetscInt        *mcolors,**ii,nc = iscoloring->n,i,base, n = iscoloring->N;
179:       ISColoringValue *colors = iscoloring->colors;
180:       IS              *is;

182: #if defined(PETSC_USE_DEBUG)
183:       for (i=0; i<n; i++) {
184:         if (((PetscInt)colors[i]) >= nc) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Coloring is our of range index %d value %d number colors %d",(int)i,(int)colors[i],(int)nc);
185:       }
186: #endif

188:       /* generate the lists of nodes for each color */
189:       PetscCalloc1(nc,&mcolors);
190:       for (i=0; i<n; i++) mcolors[colors[i]]++;

192:       PetscMalloc1(nc,&ii);
193:       PetscMalloc1(n,&ii[0]);
194:       for (i=1; i<nc; i++) ii[i] = ii[i-1] + mcolors[i-1];
195:       PetscMemzero(mcolors,nc*sizeof(PetscInt));

197:       if (iscoloring->ctype == IS_COLORING_GLOBAL) {
198:         MPI_Scan(&iscoloring->N,&base,1,MPIU_INT,MPI_SUM,iscoloring->comm);
199:         base -= iscoloring->N;
200:         for (i=0; i<n; i++) ii[colors[i]][mcolors[colors[i]]++] = i + base; /* global idx */
201:       } else if (iscoloring->ctype == IS_COLORING_GHOSTED) {
202:         for (i=0; i<n; i++) ii[colors[i]][mcolors[colors[i]]++] = i;   /* local idx */
203:       } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not provided for this ISColoringType type");

205:       PetscMalloc1(nc,&is);
206:       for (i=0; i<nc; i++) {
207:         ISCreateGeneral(iscoloring->comm,mcolors[i],ii[i],PETSC_COPY_VALUES,is+i);
208:       }

210:       iscoloring->is = is;
211:       PetscFree(ii[0]);
212:       PetscFree(ii);
213:       PetscFree(mcolors);
214:     }
215:     *isis = iscoloring->is;
216:   }
217:   return(0);
218: }

222: /*@C
223:    ISColoringRestoreIS - Restores the index sets extracted from the coloring context

225:    Collective on ISColoring

227:    Input Parameter:
228: +  iscoloring - the coloring context
229: -  is - array of index sets

231:    Level: advanced

233: .seealso: ISColoringGetIS(), ISColoringView()
234: @*/
235: PetscErrorCode  ISColoringRestoreIS(ISColoring iscoloring,IS *is[])
236: {

240:   /* currently nothing is done here */
241:   return(0);
242: }


247: /*@
248:     ISColoringCreate - Generates an ISColoring context from lists (provided
249:     by each processor) of colors for each node.

251:     Collective on MPI_Comm

253:     Input Parameters:
254: +   comm - communicator for the processors creating the coloring
255: .   ncolors - max color value
256: .   n - number of nodes on this processor
257: .   colors - array containing the colors for this processor, color numbers begin at 0.
258: -   mode - see PetscCopyMode for meaning of this flag.

260:     Output Parameter:
261: .   iscoloring - the resulting coloring data structure

263:     Options Database Key:
264: .   -is_coloring_view - Activates ISColoringView()

266:    Level: advanced

268:     Notes: By default sets coloring type to  IS_COLORING_GLOBAL

270: .seealso: MatColoringCreate(), ISColoringView(), ISColoringDestroy(), ISColoringSetType()

272: @*/
273: PetscErrorCode  ISColoringCreate(MPI_Comm comm,PetscInt ncolors,PetscInt n,const ISColoringValue colors[],PetscCopyMode mode,ISColoring *iscoloring)
274: {
276:   PetscMPIInt    size,rank,tag;
277:   PetscInt       base,top,i;
278:   PetscInt       nc,ncwork;
279:   MPI_Status     status;

282:   if (ncolors != PETSC_DECIDE && ncolors > IS_COLORING_MAX) {
283:     if (ncolors > 65535) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Max color value exeeds 65535 limit. This number is unrealistic. Perhaps a bug in code?\nCurrent max: %d user rewuested: %d",IS_COLORING_MAX,ncolors);
284:     else                 SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Max color value exeeds limit. Perhaps reconfigure PETSc with --with-is-color-value-type=short?\n Current max: %d user rewuested: %d",IS_COLORING_MAX,ncolors);
285:   }
286:   PetscNew(iscoloring);
287:   PetscCommDuplicate(comm,&(*iscoloring)->comm,&tag);
288:   comm = (*iscoloring)->comm;

290:   /* compute the number of the first node on my processor */
291:   MPI_Comm_size(comm,&size);

293:   /* should use MPI_Scan() */
294:   MPI_Comm_rank(comm,&rank);
295:   if (!rank) {
296:     base = 0;
297:     top  = n;
298:   } else {
299:     MPI_Recv(&base,1,MPIU_INT,rank-1,tag,comm,&status);
300:     top  = base+n;
301:   }
302:   if (rank < size-1) {
303:     MPI_Send(&top,1,MPIU_INT,rank+1,tag,comm);
304:   }

306:   /* compute the total number of colors */
307:   ncwork = 0;
308:   for (i=0; i<n; i++) {
309:     if (ncwork < colors[i]) ncwork = colors[i];
310:   }
311:   ncwork++;
312:   MPI_Allreduce(&ncwork,&nc,1,MPIU_INT,MPI_MAX,comm);
313:   if (nc > ncolors) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Number of colors passed in %D is less then the actual number of colors in array %D",ncolors,nc);
314:   (*iscoloring)->n      = nc;
315:   (*iscoloring)->is     = 0;
316:   (*iscoloring)->N      = n;
317:   (*iscoloring)->refct  = 1;
318:   (*iscoloring)->ctype  = IS_COLORING_GLOBAL;
319:   if (mode == PETSC_COPY_VALUES) {
320:     PetscMalloc1(n,&(*iscoloring)->colors);
321:     PetscLogObjectMemory((PetscObject)(*iscoloring),n*sizeof(ISColoringValue));
322:     PetscMemcpy((*iscoloring)->colors,colors,n*sizeof(ISColoringValue));
323:     (*iscoloring)->allocated = PETSC_TRUE;
324:   } else if (mode == PETSC_OWN_POINTER) {
325:     (*iscoloring)->colors    = (ISColoringValue*)colors;
326:     (*iscoloring)->allocated = PETSC_TRUE;
327:   } else {
328:     (*iscoloring)->colors    = (ISColoringValue*)colors;
329:     (*iscoloring)->allocated = PETSC_FALSE;
330:   }
331:   ISColoringViewFromOptions(*iscoloring,NULL,"-is_coloring_view");
332:   PetscInfo1(0,"Number of colors %D\n",nc);
333:   return(0);
334: }

338: /*@
339:     ISPartitioningToNumbering - Takes an ISPartitioning and on each processor
340:     generates an IS that contains a new global node number for each index based
341:     on the partitioing.

343:     Collective on IS

345:     Input Parameters
346: .   partitioning - a partitioning as generated by MatPartitioningApply()

348:     Output Parameter:
349: .   is - on each processor the index set that defines the global numbers
350:          (in the new numbering) for all the nodes currently (before the partitioning)
351:          on that processor

353:    Level: advanced

355: .seealso: MatPartitioningCreate(), AOCreateBasic(), ISPartitioningCount()

357: @*/
358: PetscErrorCode  ISPartitioningToNumbering(IS part,IS *is)
359: {
360:   MPI_Comm       comm;
361:   PetscInt       i,np,npt,n,*starts = NULL,*sums = NULL,*lsizes = NULL,*newi = NULL;
362:   const PetscInt *indices = NULL;

366:   PetscObjectGetComm((PetscObject)part,&comm);

368:   /* count the number of partitions, i.e., virtual processors */
369:   ISGetLocalSize(part,&n);
370:   ISGetIndices(part,&indices);
371:   np   = 0;
372:   for (i=0; i<n; i++) np = PetscMax(np,indices[i]);
373:   MPI_Allreduce(&np,&npt,1,MPIU_INT,MPI_MAX,comm);
374:   np   = npt+1; /* so that it looks like a MPI_Comm_size output */

376:   /*
377:         lsizes - number of elements of each partition on this particular processor
378:         sums - total number of "previous" nodes for any particular partition
379:         starts - global number of first element in each partition on this processor
380:   */
381:   PetscMalloc3(np,&lsizes,np,&starts,np,&sums);
382:   PetscMemzero(lsizes,np*sizeof(PetscInt));
383:   for (i=0; i<n; i++) lsizes[indices[i]]++;
384:   MPI_Allreduce(lsizes,sums,np,MPIU_INT,MPI_SUM,comm);
385:   MPI_Scan(lsizes,starts,np,MPIU_INT,MPI_SUM,comm);
386:   for (i=0; i<np; i++) starts[i] -= lsizes[i];
387:   for (i=1; i<np; i++) {
388:     sums[i]   += sums[i-1];
389:     starts[i] += sums[i-1];
390:   }

392:   /*
393:       For each local index give it the new global number
394:   */
395:   PetscMalloc1(n,&newi);
396:   for (i=0; i<n; i++) newi[i] = starts[indices[i]]++;
397:   PetscFree3(lsizes,starts,sums);

399:   ISRestoreIndices(part,&indices);
400:   ISCreateGeneral(comm,n,newi,PETSC_OWN_POINTER,is);
401:   ISSetPermutation(*is);
402:   return(0);
403: }

407: /*@
408:     ISPartitioningCount - Takes a ISPartitioning and determines the number of
409:     resulting elements on each (partition) process

411:     Collective on IS

413:     Input Parameters:
414: +   partitioning - a partitioning as generated by MatPartitioningApply()
415: -   len - length of the array count, this is the total number of partitions

417:     Output Parameter:
418: .   count - array of length size, to contain the number of elements assigned
419:         to each partition, where size is the number of partitions generated
420:          (see notes below).

422:    Level: advanced

424:     Notes:
425:         By default the number of partitions generated (and thus the length
426:         of count) is the size of the communicator associated with IS,
427:         but it can be set by MatPartitioningSetNParts. The resulting array
428:         of lengths can for instance serve as input of PCBJacobiSetTotalBlocks.


431: .seealso: MatPartitioningCreate(), AOCreateBasic(), ISPartitioningToNumbering(),
432:         MatPartitioningSetNParts(), MatPartitioningApply()

434: @*/
435: PetscErrorCode  ISPartitioningCount(IS part,PetscInt len,PetscInt count[])
436: {
437:   MPI_Comm       comm;
438:   PetscInt       i,n,*lsizes;
439:   const PetscInt *indices;
441:   PetscMPIInt    npp;

444:   PetscObjectGetComm((PetscObject)part,&comm);
445:   if (len == PETSC_DEFAULT) {
446:     PetscMPIInt size;
447:     MPI_Comm_size(comm,&size);
448:     len  = (PetscInt) size;
449:   }

451:   /* count the number of partitions */
452:   ISGetLocalSize(part,&n);
453:   ISGetIndices(part,&indices);
454: #if defined(PETSC_USE_DEBUG)
455:   {
456:     PetscInt np = 0,npt;
457:     for (i=0; i<n; i++) np = PetscMax(np,indices[i]);
458:     MPI_Allreduce(&np,&npt,1,MPIU_INT,MPI_MAX,comm);
459:     np   = npt+1; /* so that it looks like a MPI_Comm_size output */
460:     if (np > len) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Length of count array %D is less than number of partitions %D",len,np);
461:   }
462: #endif

464:   /*
465:         lsizes - number of elements of each partition on this particular processor
466:         sums - total number of "previous" nodes for any particular partition
467:         starts - global number of first element in each partition on this processor
468:   */
469:   PetscCalloc1(len,&lsizes);
470:   for (i=0; i<n; i++) lsizes[indices[i]]++;
471:   ISRestoreIndices(part,&indices);
472:   PetscMPIIntCast(len,&npp);
473:   MPI_Allreduce(lsizes,count,npp,MPIU_INT,MPI_SUM,comm);
474:   PetscFree(lsizes);
475:   return(0);
476: }

480: /*@
481:     ISAllGather - Given an index set (IS) on each processor, generates a large
482:     index set (same on each processor) by concatenating together each
483:     processors index set.

485:     Collective on IS

487:     Input Parameter:
488: .   is - the distributed index set

490:     Output Parameter:
491: .   isout - the concatenated index set (same on all processors)

493:     Notes:
494:     ISAllGather() is clearly not scalable for large index sets.

496:     The IS created on each processor must be created with a common
497:     communicator (e.g., PETSC_COMM_WORLD). If the index sets were created
498:     with PETSC_COMM_SELF, this routine will not work as expected, since
499:     each process will generate its own new IS that consists only of
500:     itself.

502:     The communicator for this new IS is PETSC_COMM_SELF

504:     Level: intermediate

506:     Concepts: gather^index sets
507:     Concepts: index sets^gathering to all processors
508:     Concepts: IS^gathering to all processors

510: .seealso: ISCreateGeneral(), ISCreateStride(), ISCreateBlock()
511: @*/
512: PetscErrorCode  ISAllGather(IS is,IS *isout)
513: {
515:   PetscInt       *indices,n,i,N,step,first;
516:   const PetscInt *lindices;
517:   MPI_Comm       comm;
518:   PetscMPIInt    size,*sizes = NULL,*offsets = NULL,nn;
519:   PetscBool      stride;


525:   PetscObjectGetComm((PetscObject)is,&comm);
526:   MPI_Comm_size(comm,&size);
527:   ISGetLocalSize(is,&n);
528:   PetscObjectTypeCompare((PetscObject)is,ISSTRIDE,&stride);
529:   if (size == 1 && stride) { /* should handle parallel ISStride also */
530:     ISStrideGetInfo(is,&first,&step);
531:     ISCreateStride(PETSC_COMM_SELF,n,first,step,isout);
532:   } else {
533:     PetscMalloc2(size,&sizes,size,&offsets);

535:     PetscMPIIntCast(n,&nn);
536:     MPI_Allgather(&nn,1,MPI_INT,sizes,1,MPI_INT,comm);
537:     offsets[0] = 0;
538:     for (i=1; i<size; i++) offsets[i] = offsets[i-1] + sizes[i-1];
539:     N = offsets[size-1] + sizes[size-1];

541:     PetscMalloc1(N,&indices);
542:     ISGetIndices(is,&lindices);
543:     MPI_Allgatherv((void*)lindices,nn,MPIU_INT,indices,sizes,offsets,MPIU_INT,comm);
544:     ISRestoreIndices(is,&lindices);
545:     PetscFree2(sizes,offsets);

547:     ISCreateGeneral(PETSC_COMM_SELF,N,indices,PETSC_OWN_POINTER,isout);
548:   }
549:   return(0);
550: }

554: /*@C
555:     ISAllGatherColors - Given a a set of colors on each processor, generates a large
556:     set (same on each processor) by concatenating together each processors colors

558:     Collective on MPI_Comm

560:     Input Parameter:
561: +   comm - communicator to share the indices
562: .   n - local size of set
563: -   lindices - local colors

565:     Output Parameter:
566: +   outN - total number of indices
567: -   outindices - all of the colors

569:     Notes:
570:     ISAllGatherColors() is clearly not scalable for large index sets.


573:     Level: intermediate

575:     Concepts: gather^index sets
576:     Concepts: index sets^gathering to all processors
577:     Concepts: IS^gathering to all processors

579: .seealso: ISCreateGeneral(), ISCreateStride(), ISCreateBlock(), ISAllGather()
580: @*/
581: PetscErrorCode  ISAllGatherColors(MPI_Comm comm,PetscInt n,ISColoringValue *lindices,PetscInt *outN,ISColoringValue *outindices[])
582: {
583:   ISColoringValue *indices;
584:   PetscErrorCode  ierr;
585:   PetscInt        i,N;
586:   PetscMPIInt     size,*offsets = NULL,*sizes = NULL, nn = n;

589:   MPI_Comm_size(comm,&size);
590:   PetscMalloc2(size,&sizes,size,&offsets);

592:   MPI_Allgather(&nn,1,MPI_INT,sizes,1,MPI_INT,comm);
593:   offsets[0] = 0;
594:   for (i=1; i<size; i++) offsets[i] = offsets[i-1] + sizes[i-1];
595:   N    = offsets[size-1] + sizes[size-1];
596:   PetscFree2(sizes,offsets);

598:   PetscMalloc1(N+1,&indices);
599:   MPI_Allgatherv(lindices,(PetscMPIInt)n,MPIU_COLORING_VALUE,indices,sizes,offsets,MPIU_COLORING_VALUE,comm);

601:   *outindices = indices;
602:   if (outN) *outN = N;
603:   return(0);
604: }

608: /*@
609:     ISComplement - Given an index set (IS) generates the complement index set. That is all
610:        all indices that are NOT in the given set.

612:     Collective on IS

614:     Input Parameter:
615: +   is - the index set
616: .   nmin - the first index desired in the local part of the complement
617: -   nmax - the largest index desired in the local part of the complement (note that all indices in is must be greater or equal to nmin and less than nmax)

619:     Output Parameter:
620: .   isout - the complement

622:     Notes:  The communicator for this new IS is the same as for the input IS

624:       For a parallel IS, this will generate the local part of the complement on each process

626:       To generate the entire complement (on each process) of a parallel IS, first call ISAllGather() and then
627:     call this routine.

629:     Level: intermediate

631:     Concepts: gather^index sets
632:     Concepts: index sets^gathering to all processors
633:     Concepts: IS^gathering to all processors

635: .seealso: ISCreateGeneral(), ISCreateStride(), ISCreateBlock(), ISAllGather()
636: @*/
637: PetscErrorCode  ISComplement(IS is,PetscInt nmin,PetscInt nmax,IS *isout)
638: {
640:   const PetscInt *indices;
641:   PetscInt       n,i,j,unique,cnt,*nindices;
642:   PetscBool      sorted;

647:   if (nmin < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"nmin %D cannot be negative",nmin);
648:   if (nmin > nmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"nmin %D cannot be greater than nmax %D",nmin,nmax);
649:   ISSorted(is,&sorted);
650:   if (!sorted) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Index set must be sorted");

652:   ISGetLocalSize(is,&n);
653:   ISGetIndices(is,&indices);
654: #if defined(PETSC_USE_DEBUG)
655:   for (i=0; i<n; i++) {
656:     if (indices[i] <  nmin) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index %D's value %D is smaller than minimum given %D",i,indices[i],nmin);
657:     if (indices[i] >= nmax) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index %D's value %D is larger than maximum given %D",i,indices[i],nmax);
658:   }
659: #endif
660:   /* Count number of unique entries */
661:   unique = (n>0);
662:   for (i=0; i<n-1; i++) {
663:     if (indices[i+1] != indices[i]) unique++;
664:   }
665:   PetscMalloc1(nmax-nmin-unique,&nindices);
666:   cnt  = 0;
667:   for (i=nmin,j=0; i<nmax; i++) {
668:     if (j<n && i==indices[j]) do { j++; } while (j<n && i==indices[j]);
669:     else nindices[cnt++] = i;
670:   }
671:   if (cnt != nmax-nmin-unique) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Number of entries found in complement %D does not match expected %D",cnt,nmax-nmin-unique);
672:   ISCreateGeneral(PetscObjectComm((PetscObject)is),cnt,nindices,PETSC_OWN_POINTER,isout);
673:   ISRestoreIndices(is,&indices);
674:   return(0);
675: }