xref: /petsc/src/vec/is/ao/impls/basic/aobasic.c (revision 48a46eb9bd028bec07ec0f396b1a3abb43f14558)
11447629fSBarry Smith 
21447629fSBarry Smith /*
31447629fSBarry Smith     The most basic AO application ordering routines. These store the
41447629fSBarry Smith   entire orderings on each processor.
51447629fSBarry Smith */
61447629fSBarry Smith 
71447629fSBarry Smith #include <../src/vec/is/ao/aoimpl.h> /*I  "petscao.h"   I*/
81447629fSBarry Smith 
91447629fSBarry Smith typedef struct {
101447629fSBarry Smith   PetscInt *app;   /* app[i] is the partner for the ith PETSc slot */
111447629fSBarry Smith   PetscInt *petsc; /* petsc[j] is the partner for the jth app slot */
121447629fSBarry Smith } AO_Basic;
131447629fSBarry Smith 
141447629fSBarry Smith /*
151447629fSBarry Smith        All processors have the same data so processor 1 prints it
161447629fSBarry Smith */
179371c9d4SSatish Balay PetscErrorCode AOView_Basic(AO ao, PetscViewer viewer) {
181447629fSBarry Smith   PetscMPIInt rank;
191447629fSBarry Smith   PetscInt    i;
201447629fSBarry Smith   AO_Basic   *aobasic = (AO_Basic *)ao->data;
211447629fSBarry Smith   PetscBool   iascii;
221447629fSBarry Smith 
231447629fSBarry Smith   PetscFunctionBegin;
249566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)ao), &rank));
25dd400576SPatrick Sanan   if (rank == 0) {
269566063dSJacob Faibussowitsch     PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
271447629fSBarry Smith     if (iascii) {
289566063dSJacob Faibussowitsch       PetscCall(PetscViewerASCIIPrintf(viewer, "Number of elements in ordering %" PetscInt_FMT "\n", ao->N));
299566063dSJacob Faibussowitsch       PetscCall(PetscViewerASCIIPrintf(viewer, "PETSc->App  App->PETSc\n"));
30*48a46eb9SPierre Jolivet       for (i = 0; i < ao->N; i++) PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT "  %3" PetscInt_FMT "    %3" PetscInt_FMT "  %3" PetscInt_FMT "\n", i, aobasic->app[i], i, aobasic->petsc[i]));
311447629fSBarry Smith     }
321447629fSBarry Smith   }
339566063dSJacob Faibussowitsch   PetscCall(PetscViewerFlush(viewer));
341447629fSBarry Smith   PetscFunctionReturn(0);
351447629fSBarry Smith }
361447629fSBarry Smith 
379371c9d4SSatish Balay PetscErrorCode AODestroy_Basic(AO ao) {
381447629fSBarry Smith   AO_Basic *aobasic = (AO_Basic *)ao->data;
391447629fSBarry Smith 
401447629fSBarry Smith   PetscFunctionBegin;
419566063dSJacob Faibussowitsch   PetscCall(PetscFree2(aobasic->app, aobasic->petsc));
429566063dSJacob Faibussowitsch   PetscCall(PetscFree(aobasic));
431447629fSBarry Smith   PetscFunctionReturn(0);
441447629fSBarry Smith }
451447629fSBarry Smith 
469371c9d4SSatish Balay PetscErrorCode AOBasicGetIndices_Private(AO ao, PetscInt **app, PetscInt **petsc) {
471447629fSBarry Smith   AO_Basic *basic = (AO_Basic *)ao->data;
481447629fSBarry Smith 
491447629fSBarry Smith   PetscFunctionBegin;
501447629fSBarry Smith   if (app) *app = basic->app;
511447629fSBarry Smith   if (petsc) *petsc = basic->petsc;
521447629fSBarry Smith   PetscFunctionReturn(0);
531447629fSBarry Smith }
541447629fSBarry Smith 
559371c9d4SSatish Balay PetscErrorCode AOPetscToApplication_Basic(AO ao, PetscInt n, PetscInt *ia) {
561447629fSBarry Smith   PetscInt  i, N = ao->N;
571447629fSBarry Smith   AO_Basic *aobasic = (AO_Basic *)ao->data;
581447629fSBarry Smith 
591447629fSBarry Smith   PetscFunctionBegin;
601447629fSBarry Smith   for (i = 0; i < n; i++) {
611447629fSBarry Smith     if (ia[i] >= 0 && ia[i] < N) {
621447629fSBarry Smith       ia[i] = aobasic->app[ia[i]];
631447629fSBarry Smith     } else {
641447629fSBarry Smith       ia[i] = -1;
651447629fSBarry Smith     }
661447629fSBarry Smith   }
671447629fSBarry Smith   PetscFunctionReturn(0);
681447629fSBarry Smith }
691447629fSBarry Smith 
709371c9d4SSatish Balay PetscErrorCode AOApplicationToPetsc_Basic(AO ao, PetscInt n, PetscInt *ia) {
711447629fSBarry Smith   PetscInt  i, N = ao->N;
721447629fSBarry Smith   AO_Basic *aobasic = (AO_Basic *)ao->data;
731447629fSBarry Smith 
741447629fSBarry Smith   PetscFunctionBegin;
751447629fSBarry Smith   for (i = 0; i < n; i++) {
761447629fSBarry Smith     if (ia[i] >= 0 && ia[i] < N) {
771447629fSBarry Smith       ia[i] = aobasic->petsc[ia[i]];
781447629fSBarry Smith     } else {
791447629fSBarry Smith       ia[i] = -1;
801447629fSBarry Smith     }
811447629fSBarry Smith   }
821447629fSBarry Smith   PetscFunctionReturn(0);
831447629fSBarry Smith }
841447629fSBarry Smith 
859371c9d4SSatish Balay PetscErrorCode AOPetscToApplicationPermuteInt_Basic(AO ao, PetscInt block, PetscInt *array) {
861447629fSBarry Smith   AO_Basic *aobasic = (AO_Basic *)ao->data;
871447629fSBarry Smith   PetscInt *temp;
881447629fSBarry Smith   PetscInt  i, j;
891447629fSBarry Smith 
901447629fSBarry Smith   PetscFunctionBegin;
919566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(ao->N * block, &temp));
921447629fSBarry Smith   for (i = 0; i < ao->N; i++) {
931447629fSBarry Smith     for (j = 0; j < block; j++) temp[i * block + j] = array[aobasic->petsc[i] * block + j];
941447629fSBarry Smith   }
959566063dSJacob Faibussowitsch   PetscCall(PetscArraycpy(array, temp, ao->N * block));
969566063dSJacob Faibussowitsch   PetscCall(PetscFree(temp));
971447629fSBarry Smith   PetscFunctionReturn(0);
981447629fSBarry Smith }
991447629fSBarry Smith 
1009371c9d4SSatish Balay PetscErrorCode AOApplicationToPetscPermuteInt_Basic(AO ao, PetscInt block, PetscInt *array) {
1011447629fSBarry Smith   AO_Basic *aobasic = (AO_Basic *)ao->data;
1021447629fSBarry Smith   PetscInt *temp;
1031447629fSBarry Smith   PetscInt  i, j;
1041447629fSBarry Smith 
1051447629fSBarry Smith   PetscFunctionBegin;
1069566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(ao->N * block, &temp));
1071447629fSBarry Smith   for (i = 0; i < ao->N; i++) {
1081447629fSBarry Smith     for (j = 0; j < block; j++) temp[i * block + j] = array[aobasic->app[i] * block + j];
1091447629fSBarry Smith   }
1109566063dSJacob Faibussowitsch   PetscCall(PetscArraycpy(array, temp, ao->N * block));
1119566063dSJacob Faibussowitsch   PetscCall(PetscFree(temp));
1121447629fSBarry Smith   PetscFunctionReturn(0);
1131447629fSBarry Smith }
1141447629fSBarry Smith 
1159371c9d4SSatish Balay PetscErrorCode AOPetscToApplicationPermuteReal_Basic(AO ao, PetscInt block, PetscReal *array) {
1161447629fSBarry Smith   AO_Basic  *aobasic = (AO_Basic *)ao->data;
1171447629fSBarry Smith   PetscReal *temp;
1181447629fSBarry Smith   PetscInt   i, j;
1191447629fSBarry Smith 
1201447629fSBarry Smith   PetscFunctionBegin;
1219566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(ao->N * block, &temp));
1221447629fSBarry Smith   for (i = 0; i < ao->N; i++) {
1231447629fSBarry Smith     for (j = 0; j < block; j++) temp[i * block + j] = array[aobasic->petsc[i] * block + j];
1241447629fSBarry Smith   }
1259566063dSJacob Faibussowitsch   PetscCall(PetscArraycpy(array, temp, ao->N * block));
1269566063dSJacob Faibussowitsch   PetscCall(PetscFree(temp));
1271447629fSBarry Smith   PetscFunctionReturn(0);
1281447629fSBarry Smith }
1291447629fSBarry Smith 
1309371c9d4SSatish Balay PetscErrorCode AOApplicationToPetscPermuteReal_Basic(AO ao, PetscInt block, PetscReal *array) {
1311447629fSBarry Smith   AO_Basic  *aobasic = (AO_Basic *)ao->data;
1321447629fSBarry Smith   PetscReal *temp;
1331447629fSBarry Smith   PetscInt   i, j;
1341447629fSBarry Smith 
1351447629fSBarry Smith   PetscFunctionBegin;
1369566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(ao->N * block, &temp));
1371447629fSBarry Smith   for (i = 0; i < ao->N; i++) {
1381447629fSBarry Smith     for (j = 0; j < block; j++) temp[i * block + j] = array[aobasic->app[i] * block + j];
1391447629fSBarry Smith   }
1409566063dSJacob Faibussowitsch   PetscCall(PetscArraycpy(array, temp, ao->N * block));
1419566063dSJacob Faibussowitsch   PetscCall(PetscFree(temp));
1421447629fSBarry Smith   PetscFunctionReturn(0);
1431447629fSBarry Smith }
1441447629fSBarry Smith 
1451447629fSBarry Smith static struct _AOOps AOOps_Basic = {
146267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(view, AOView_Basic),
147267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(destroy, AODestroy_Basic),
148267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(petsctoapplication, AOPetscToApplication_Basic),
149267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(applicationtopetsc, AOApplicationToPetsc_Basic),
150267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(petsctoapplicationpermuteint, AOPetscToApplicationPermuteInt_Basic),
151267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(applicationtopetscpermuteint, AOApplicationToPetscPermuteInt_Basic),
152267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(petsctoapplicationpermutereal, AOPetscToApplicationPermuteReal_Basic),
153267267bdSJacob Faibussowitsch   PetscDesignatedInitializer(applicationtopetscpermutereal, AOApplicationToPetscPermuteReal_Basic),
1541447629fSBarry Smith };
1551447629fSBarry Smith 
1569371c9d4SSatish Balay PETSC_EXTERN PetscErrorCode AOCreate_Basic(AO ao) {
1571447629fSBarry Smith   AO_Basic       *aobasic;
1581447629fSBarry Smith   PetscMPIInt     size, rank, count, *lens, *disp;
1591447629fSBarry Smith   PetscInt        napp, *allpetsc, *allapp, ip, ia, N, i, *petsc = NULL, start;
1601447629fSBarry Smith   IS              isapp = ao->isapp, ispetsc = ao->ispetsc;
1611447629fSBarry Smith   MPI_Comm        comm;
1621447629fSBarry Smith   const PetscInt *myapp, *mypetsc = NULL;
1631447629fSBarry Smith 
1641447629fSBarry Smith   PetscFunctionBegin;
1651447629fSBarry Smith   /* create special struct aobasic */
1669566063dSJacob Faibussowitsch   PetscCall(PetscNewLog(ao, &aobasic));
1671447629fSBarry Smith   ao->data = (void *)aobasic;
1689566063dSJacob Faibussowitsch   PetscCall(PetscMemcpy(ao->ops, &AOOps_Basic, sizeof(struct _AOOps)));
1699566063dSJacob Faibussowitsch   PetscCall(PetscObjectChangeTypeName((PetscObject)ao, AOBASIC));
1701447629fSBarry Smith 
1719566063dSJacob Faibussowitsch   PetscCall(ISGetLocalSize(isapp, &napp));
1729566063dSJacob Faibussowitsch   PetscCall(ISGetIndices(isapp, &myapp));
1731447629fSBarry Smith 
1749566063dSJacob Faibussowitsch   PetscCall(PetscMPIIntCast(napp, &count));
1751447629fSBarry Smith 
1761447629fSBarry Smith   /* transmit all lengths to all processors */
1779566063dSJacob Faibussowitsch   PetscCall(PetscObjectGetComm((PetscObject)isapp, &comm));
1789566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_size(comm, &size));
1799566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(comm, &rank));
1809566063dSJacob Faibussowitsch   PetscCall(PetscMalloc2(size, &lens, size, &disp));
1819566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Allgather(&count, 1, MPI_INT, lens, 1, MPI_INT, comm));
1821447629fSBarry Smith   N = 0;
1831447629fSBarry Smith   for (i = 0; i < size; i++) {
1849566063dSJacob Faibussowitsch     PetscCall(PetscMPIIntCast(N, disp + i)); /* = sum(lens[j]), j< i */
1851447629fSBarry Smith     N += lens[i];
1861447629fSBarry Smith   }
1871447629fSBarry Smith   ao->N = N;
1881447629fSBarry Smith   ao->n = N;
1891447629fSBarry Smith 
1901447629fSBarry Smith   /* If mypetsc is 0 then use "natural" numbering */
1911447629fSBarry Smith   if (napp) {
1921447629fSBarry Smith     if (!ispetsc) {
1931447629fSBarry Smith       start = disp[rank];
1949566063dSJacob Faibussowitsch       PetscCall(PetscMalloc1(napp + 1, &petsc));
1951447629fSBarry Smith       for (i = 0; i < napp; i++) petsc[i] = start + i;
1961447629fSBarry Smith     } else {
1979566063dSJacob Faibussowitsch       PetscCall(ISGetIndices(ispetsc, &mypetsc));
1981447629fSBarry Smith       petsc = (PetscInt *)mypetsc;
1991447629fSBarry Smith     }
2001447629fSBarry Smith   }
2011447629fSBarry Smith 
2021447629fSBarry Smith   /* get all indices on all processors */
2039566063dSJacob Faibussowitsch   PetscCall(PetscMalloc2(N, &allpetsc, N, &allapp));
2049566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Allgatherv(petsc, count, MPIU_INT, allpetsc, lens, disp, MPIU_INT, comm));
2059566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Allgatherv((void *)myapp, count, MPIU_INT, allapp, lens, disp, MPIU_INT, comm));
2069566063dSJacob Faibussowitsch   PetscCall(PetscFree2(lens, disp));
2071447629fSBarry Smith 
2084e1ad211SJed Brown   if (PetscDefined(USE_DEBUG)) {
2091447629fSBarry Smith     PetscInt *sorted;
2109566063dSJacob Faibussowitsch     PetscCall(PetscMalloc1(N, &sorted));
2111447629fSBarry Smith 
2129566063dSJacob Faibussowitsch     PetscCall(PetscArraycpy(sorted, allpetsc, N));
2139566063dSJacob Faibussowitsch     PetscCall(PetscSortInt(N, sorted));
2149371c9d4SSatish Balay     for (i = 0; i < N; i++) { PetscCheck(sorted[i] == i, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "PETSc ordering requires a permutation of numbers 0 to N-1\n it is missing %" PetscInt_FMT " has %" PetscInt_FMT, i, sorted[i]); }
2151447629fSBarry Smith 
2169566063dSJacob Faibussowitsch     PetscCall(PetscArraycpy(sorted, allapp, N));
2179566063dSJacob Faibussowitsch     PetscCall(PetscSortInt(N, sorted));
2189371c9d4SSatish Balay     for (i = 0; i < N; i++) { PetscCheck(sorted[i] == i, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Application ordering requires a permutation of numbers 0 to N-1\n it is missing %" PetscInt_FMT " has %" PetscInt_FMT, i, sorted[i]); }
2191447629fSBarry Smith 
2209566063dSJacob Faibussowitsch     PetscCall(PetscFree(sorted));
2211447629fSBarry Smith   }
2221447629fSBarry Smith 
2231447629fSBarry Smith   /* generate a list of application and PETSc node numbers */
2249566063dSJacob Faibussowitsch   PetscCall(PetscCalloc2(N, &aobasic->app, N, &aobasic->petsc));
2259566063dSJacob Faibussowitsch   PetscCall(PetscLogObjectMemory((PetscObject)ao, 2 * N * sizeof(PetscInt)));
2261447629fSBarry Smith   for (i = 0; i < N; i++) {
2271447629fSBarry Smith     ip = allpetsc[i];
2281447629fSBarry Smith     ia = allapp[i];
2291447629fSBarry Smith     /* check there are no duplicates */
230c9cc58a2SBarry Smith     PetscCheck(!aobasic->app[ip], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Duplicate in PETSc ordering at position %" PetscInt_FMT ". Already mapped to %" PetscInt_FMT ", not %" PetscInt_FMT ".", i, aobasic->app[ip] - 1, ia);
2311447629fSBarry Smith     aobasic->app[ip] = ia + 1;
232c9cc58a2SBarry Smith     PetscCheck(!aobasic->petsc[ia], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Duplicate in Application ordering at position %" PetscInt_FMT ". Already mapped to %" PetscInt_FMT ", not %" PetscInt_FMT ".", i, aobasic->petsc[ia] - 1, ip);
2331447629fSBarry Smith     aobasic->petsc[ia] = ip + 1;
2341447629fSBarry Smith   }
235*48a46eb9SPierre Jolivet   if (napp && !mypetsc) PetscCall(PetscFree(petsc));
2369566063dSJacob Faibussowitsch   PetscCall(PetscFree2(allpetsc, allapp));
2371447629fSBarry Smith   /* shift indices down by one */
2381447629fSBarry Smith   for (i = 0; i < N; i++) {
2391447629fSBarry Smith     aobasic->app[i]--;
2401447629fSBarry Smith     aobasic->petsc[i]--;
2411447629fSBarry Smith   }
2421447629fSBarry Smith 
2439566063dSJacob Faibussowitsch   PetscCall(ISRestoreIndices(isapp, &myapp));
2441447629fSBarry Smith   if (napp) {
2451447629fSBarry Smith     if (ispetsc) {
2469566063dSJacob Faibussowitsch       PetscCall(ISRestoreIndices(ispetsc, &mypetsc));
2471447629fSBarry Smith     } else {
2489566063dSJacob Faibussowitsch       PetscCall(PetscFree(petsc));
2491447629fSBarry Smith     }
2501447629fSBarry Smith   }
2511447629fSBarry Smith   PetscFunctionReturn(0);
2521447629fSBarry Smith }
2531447629fSBarry Smith 
2541447629fSBarry Smith /*@C
2551447629fSBarry Smith    AOCreateBasic - Creates a basic application ordering using two integer arrays.
2561447629fSBarry Smith 
257d083f849SBarry Smith    Collective
2581447629fSBarry Smith 
2591447629fSBarry Smith    Input Parameters:
2601447629fSBarry Smith +  comm - MPI communicator that is to share AO
2611447629fSBarry Smith .  napp - size of integer arrays
2621447629fSBarry Smith .  myapp - integer array that defines an ordering
2631447629fSBarry Smith -  mypetsc - integer array that defines another ordering (may be NULL to
2641447629fSBarry Smith              indicate the natural ordering, that is 0,1,2,3,...)
2651447629fSBarry Smith 
2661447629fSBarry Smith    Output Parameter:
2671447629fSBarry Smith .  aoout - the new application ordering
2681447629fSBarry Smith 
2691447629fSBarry Smith    Level: beginner
2701447629fSBarry Smith 
27195452b02SPatrick Sanan     Notes:
27295452b02SPatrick Sanan     the arrays myapp and mypetsc must contain the all the integers 0 to napp-1 with no duplicates; that is there cannot be any "holes"
2731447629fSBarry Smith            in the indices. Use AOCreateMapping() or AOCreateMappingIS() if you wish to have "holes" in the indices.
2741447629fSBarry Smith 
275db781477SPatrick Sanan .seealso: `AOCreateBasicIS()`, `AODestroy()`, `AOPetscToApplication()`, `AOApplicationToPetsc()`
2761447629fSBarry Smith @*/
2779371c9d4SSatish Balay PetscErrorCode AOCreateBasic(MPI_Comm comm, PetscInt napp, const PetscInt myapp[], const PetscInt mypetsc[], AO *aoout) {
2781447629fSBarry Smith   IS              isapp, ispetsc;
2791447629fSBarry Smith   const PetscInt *app = myapp, *petsc = mypetsc;
2801447629fSBarry Smith 
2811447629fSBarry Smith   PetscFunctionBegin;
2829566063dSJacob Faibussowitsch   PetscCall(ISCreateGeneral(comm, napp, app, PETSC_USE_POINTER, &isapp));
2831447629fSBarry Smith   if (mypetsc) {
2849566063dSJacob Faibussowitsch     PetscCall(ISCreateGeneral(comm, napp, petsc, PETSC_USE_POINTER, &ispetsc));
2851447629fSBarry Smith   } else {
2861447629fSBarry Smith     ispetsc = NULL;
2871447629fSBarry Smith   }
2889566063dSJacob Faibussowitsch   PetscCall(AOCreateBasicIS(isapp, ispetsc, aoout));
2899566063dSJacob Faibussowitsch   PetscCall(ISDestroy(&isapp));
290*48a46eb9SPierre Jolivet   if (mypetsc) PetscCall(ISDestroy(&ispetsc));
2911447629fSBarry Smith   PetscFunctionReturn(0);
2921447629fSBarry Smith }
2931447629fSBarry Smith 
2941447629fSBarry Smith /*@C
2951447629fSBarry Smith    AOCreateBasicIS - Creates a basic application ordering using two index sets.
2961447629fSBarry Smith 
2971447629fSBarry Smith    Collective on IS
2981447629fSBarry Smith 
2991447629fSBarry Smith    Input Parameters:
3001447629fSBarry Smith +  isapp - index set that defines an ordering
3011447629fSBarry Smith -  ispetsc - index set that defines another ordering (may be NULL to use the
3021447629fSBarry Smith              natural ordering)
3031447629fSBarry Smith 
3041447629fSBarry Smith    Output Parameter:
3051447629fSBarry Smith .  aoout - the new application ordering
3061447629fSBarry Smith 
3071447629fSBarry Smith    Level: beginner
3081447629fSBarry Smith 
30995452b02SPatrick Sanan     Notes:
31095452b02SPatrick Sanan     the index sets isapp and ispetsc must contain the all the integers 0 to napp-1 (where napp is the length of the index sets) with no duplicates;
3111447629fSBarry Smith            that is there cannot be any "holes"
3121447629fSBarry Smith 
313db781477SPatrick Sanan .seealso: `AOCreateBasic()`, `AODestroy()`
3141447629fSBarry Smith @*/
3159371c9d4SSatish Balay PetscErrorCode AOCreateBasicIS(IS isapp, IS ispetsc, AO *aoout) {
3161447629fSBarry Smith   MPI_Comm comm;
3171447629fSBarry Smith   AO       ao;
3181447629fSBarry Smith 
3191447629fSBarry Smith   PetscFunctionBegin;
3209566063dSJacob Faibussowitsch   PetscCall(PetscObjectGetComm((PetscObject)isapp, &comm));
3219566063dSJacob Faibussowitsch   PetscCall(AOCreate(comm, &ao));
3229566063dSJacob Faibussowitsch   PetscCall(AOSetIS(ao, isapp, ispetsc));
3239566063dSJacob Faibussowitsch   PetscCall(AOSetType(ao, AOBASIC));
3249566063dSJacob Faibussowitsch   PetscCall(AOViewFromOptions(ao, NULL, "-ao_view"));
3251447629fSBarry Smith   *aoout = ao;
3261447629fSBarry Smith   PetscFunctionReturn(0);
3271447629fSBarry Smith }
328