xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision bb1d7374b64f295b2ed5ff23b89435d65e905a54)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>   /*I "petscmat.h" I*/
3 #include <petsc/private/vecimpl.h>
4 #include <petsc/private/isimpl.h>
5 #include <petscblaslapack.h>
6 #include <petscsf.h>
7 
8 /*MC
9    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
10 
11    This matrix type is identical to MATSEQAIJ when constructed with a single process communicator,
12    and MATMPIAIJ otherwise.  As a result, for single process communicators,
13   MatSeqAIJSetPreallocation is supported, and similarly MatMPIAIJSetPreallocation is supported
14   for communicators controlling multiple processes.  It is recommended that you call both of
15   the above preallocation routines for simplicity.
16 
17    Options Database Keys:
18 . -mat_type aij - sets the matrix type to "aij" during a call to MatSetFromOptions()
19 
20   Developer Notes: Subclasses include MATAIJCUSP, MATAIJCUSPARSE, MATAIJPERM, MATAIJCRL, and also automatically switches over to use inodes when
21    enough exist.
22 
23   Level: beginner
24 
25 .seealso: MatCreateAIJ(), MatCreateSeqAIJ(), MATSEQAIJ,MATMPIAIJ
26 M*/
27 
28 /*MC
29    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
30 
31    This matrix type is identical to MATSEQAIJCRL when constructed with a single process communicator,
32    and MATMPIAIJCRL otherwise.  As a result, for single process communicators,
33    MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
34   for communicators controlling multiple processes.  It is recommended that you call both of
35   the above preallocation routines for simplicity.
36 
37    Options Database Keys:
38 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to MatSetFromOptions()
39 
40   Level: beginner
41 
42 .seealso: MatCreateMPIAIJCRL,MATSEQAIJCRL,MATMPIAIJCRL, MATSEQAIJCRL, MATMPIAIJCRL
43 M*/
44 
45 #undef __FUNCT__
46 #define __FUNCT__ "MatFindNonzeroRows_MPIAIJ"
47 PetscErrorCode MatFindNonzeroRows_MPIAIJ(Mat M,IS *keptrows)
48 {
49   PetscErrorCode  ierr;
50   Mat_MPIAIJ      *mat = (Mat_MPIAIJ*)M->data;
51   Mat_SeqAIJ      *a   = (Mat_SeqAIJ*)mat->A->data;
52   Mat_SeqAIJ      *b   = (Mat_SeqAIJ*)mat->B->data;
53   const PetscInt  *ia,*ib;
54   const MatScalar *aa,*bb;
55   PetscInt        na,nb,i,j,*rows,cnt=0,n0rows;
56   PetscInt        m = M->rmap->n,rstart = M->rmap->rstart;
57 
58   PetscFunctionBegin;
59   *keptrows = 0;
60   ia        = a->i;
61   ib        = b->i;
62   for (i=0; i<m; i++) {
63     na = ia[i+1] - ia[i];
64     nb = ib[i+1] - ib[i];
65     if (!na && !nb) {
66       cnt++;
67       goto ok1;
68     }
69     aa = a->a + ia[i];
70     for (j=0; j<na; j++) {
71       if (aa[j] != 0.0) goto ok1;
72     }
73     bb = b->a + ib[i];
74     for (j=0; j <nb; j++) {
75       if (bb[j] != 0.0) goto ok1;
76     }
77     cnt++;
78 ok1:;
79   }
80   ierr = MPI_Allreduce(&cnt,&n0rows,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)M));CHKERRQ(ierr);
81   if (!n0rows) PetscFunctionReturn(0);
82   ierr = PetscMalloc1(M->rmap->n-cnt,&rows);CHKERRQ(ierr);
83   cnt  = 0;
84   for (i=0; i<m; i++) {
85     na = ia[i+1] - ia[i];
86     nb = ib[i+1] - ib[i];
87     if (!na && !nb) continue;
88     aa = a->a + ia[i];
89     for (j=0; j<na;j++) {
90       if (aa[j] != 0.0) {
91         rows[cnt++] = rstart + i;
92         goto ok2;
93       }
94     }
95     bb = b->a + ib[i];
96     for (j=0; j<nb; j++) {
97       if (bb[j] != 0.0) {
98         rows[cnt++] = rstart + i;
99         goto ok2;
100       }
101     }
102 ok2:;
103   }
104   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),cnt,rows,PETSC_OWN_POINTER,keptrows);CHKERRQ(ierr);
105   PetscFunctionReturn(0);
106 }
107 
108 #undef __FUNCT__
109 #define __FUNCT__ "MatDiagonalSet_MPIAIJ"
110 PetscErrorCode  MatDiagonalSet_MPIAIJ(Mat Y,Vec D,InsertMode is)
111 {
112   PetscErrorCode    ierr;
113   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*) Y->data;
114 
115   PetscFunctionBegin;
116   if (Y->assembled && Y->rmap->rstart == Y->cmap->rstart && Y->rmap->rend == Y->cmap->rend) {
117     ierr = MatDiagonalSet(aij->A,D,is);CHKERRQ(ierr);
118   } else {
119     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
120   }
121   PetscFunctionReturn(0);
122 }
123 
124 
125 #undef __FUNCT__
126 #define __FUNCT__ "MatFindZeroDiagonals_MPIAIJ"
127 PetscErrorCode MatFindZeroDiagonals_MPIAIJ(Mat M,IS *zrows)
128 {
129   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)M->data;
130   PetscErrorCode ierr;
131   PetscInt       i,rstart,nrows,*rows;
132 
133   PetscFunctionBegin;
134   *zrows = NULL;
135   ierr   = MatFindZeroDiagonals_SeqAIJ_Private(aij->A,&nrows,&rows);CHKERRQ(ierr);
136   ierr   = MatGetOwnershipRange(M,&rstart,NULL);CHKERRQ(ierr);
137   for (i=0; i<nrows; i++) rows[i] += rstart;
138   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),nrows,rows,PETSC_OWN_POINTER,zrows);CHKERRQ(ierr);
139   PetscFunctionReturn(0);
140 }
141 
142 #undef __FUNCT__
143 #define __FUNCT__ "MatGetColumnNorms_MPIAIJ"
144 PetscErrorCode MatGetColumnNorms_MPIAIJ(Mat A,NormType type,PetscReal *norms)
145 {
146   PetscErrorCode ierr;
147   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)A->data;
148   PetscInt       i,n,*garray = aij->garray;
149   Mat_SeqAIJ     *a_aij = (Mat_SeqAIJ*) aij->A->data;
150   Mat_SeqAIJ     *b_aij = (Mat_SeqAIJ*) aij->B->data;
151   PetscReal      *work;
152 
153   PetscFunctionBegin;
154   ierr = MatGetSize(A,NULL,&n);CHKERRQ(ierr);
155   ierr = PetscCalloc1(n,&work);CHKERRQ(ierr);
156   if (type == NORM_2) {
157     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
158       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]*a_aij->a[i]);
159     }
160     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
161       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]*b_aij->a[i]);
162     }
163   } else if (type == NORM_1) {
164     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
165       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
166     }
167     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
168       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
169     }
170   } else if (type == NORM_INFINITY) {
171     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
172       work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
173     }
174     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
175       work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]),work[garray[b_aij->j[i]]]);
176     }
177 
178   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONG,"Unknown NormType");
179   if (type == NORM_INFINITY) {
180     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
181   } else {
182     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
183   }
184   ierr = PetscFree(work);CHKERRQ(ierr);
185   if (type == NORM_2) {
186     for (i=0; i<n; i++) norms[i] = PetscSqrtReal(norms[i]);
187   }
188   PetscFunctionReturn(0);
189 }
190 
191 #undef __FUNCT__
192 #define __FUNCT__ "MatFindOffBlockDiagonalEntries_MPIAIJ"
193 PetscErrorCode MatFindOffBlockDiagonalEntries_MPIAIJ(Mat A,IS *is)
194 {
195   Mat_MPIAIJ      *a  = (Mat_MPIAIJ*)A->data;
196   IS              sis,gis;
197   PetscErrorCode  ierr;
198   const PetscInt  *isis,*igis;
199   PetscInt        n,*iis,nsis,ngis,rstart,i;
200 
201   PetscFunctionBegin;
202   ierr = MatFindOffBlockDiagonalEntries(a->A,&sis);CHKERRQ(ierr);
203   ierr = MatFindNonzeroRows(a->B,&gis);CHKERRQ(ierr);
204   ierr = ISGetSize(gis,&ngis);CHKERRQ(ierr);
205   ierr = ISGetSize(sis,&nsis);CHKERRQ(ierr);
206   ierr = ISGetIndices(sis,&isis);CHKERRQ(ierr);
207   ierr = ISGetIndices(gis,&igis);CHKERRQ(ierr);
208 
209   ierr = PetscMalloc1(ngis+nsis,&iis);CHKERRQ(ierr);
210   ierr = PetscMemcpy(iis,igis,ngis*sizeof(PetscInt));CHKERRQ(ierr);
211   ierr = PetscMemcpy(iis+ngis,isis,nsis*sizeof(PetscInt));CHKERRQ(ierr);
212   n    = ngis + nsis;
213   ierr = PetscSortRemoveDupsInt(&n,iis);CHKERRQ(ierr);
214   ierr = MatGetOwnershipRange(A,&rstart,NULL);CHKERRQ(ierr);
215   for (i=0; i<n; i++) iis[i] += rstart;
216   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)A),n,iis,PETSC_OWN_POINTER,is);CHKERRQ(ierr);
217 
218   ierr = ISRestoreIndices(sis,&isis);CHKERRQ(ierr);
219   ierr = ISRestoreIndices(gis,&igis);CHKERRQ(ierr);
220   ierr = ISDestroy(&sis);CHKERRQ(ierr);
221   ierr = ISDestroy(&gis);CHKERRQ(ierr);
222   PetscFunctionReturn(0);
223 }
224 
225 #undef __FUNCT__
226 #define __FUNCT__ "MatDistribute_MPIAIJ"
227 /*
228     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
229     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
230 
231     Only for square matrices
232 
233     Used by a preconditioner, hence PETSC_EXTERN
234 */
235 PETSC_EXTERN PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
236 {
237   PetscMPIInt    rank,size;
238   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz = 0,*gmataj,cnt,row,*ld,bses[2];
239   PetscErrorCode ierr;
240   Mat            mat;
241   Mat_SeqAIJ     *gmata;
242   PetscMPIInt    tag;
243   MPI_Status     status;
244   PetscBool      aij;
245   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
246 
247   PetscFunctionBegin;
248   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
249   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
250   if (!rank) {
251     ierr = PetscObjectTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
252     if (!aij) SETERRQ1(PetscObjectComm((PetscObject)gmat),PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
253   }
254   if (reuse == MAT_INITIAL_MATRIX) {
255     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
256     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
257     ierr = MatGetBlockSizes(gmat,&bses[0],&bses[1]);CHKERRQ(ierr);
258     ierr = MPI_Bcast(bses,2,MPIU_INT,0,comm);CHKERRQ(ierr);
259     ierr = MatSetBlockSizes(mat,bses[0],bses[1]);CHKERRQ(ierr);
260     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
261     ierr = PetscMalloc1(size+1,&rowners);CHKERRQ(ierr);
262     ierr = PetscMalloc2(m,&dlens,m,&olens);CHKERRQ(ierr);
263     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
264 
265     rowners[0] = 0;
266     for (i=2; i<=size; i++) rowners[i] += rowners[i-1];
267     rstart = rowners[rank];
268     rend   = rowners[rank+1];
269     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
270     if (!rank) {
271       gmata = (Mat_SeqAIJ*) gmat->data;
272       /* send row lengths to all processors */
273       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
274       for (i=1; i<size; i++) {
275         ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
276       }
277       /* determine number diagonal and off-diagonal counts */
278       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
279       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
280       jj   = 0;
281       for (i=0; i<m; i++) {
282         for (j=0; j<dlens[i]; j++) {
283           if (gmata->j[jj] < rstart) ld[i]++;
284           if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
285           jj++;
286         }
287       }
288       /* send column indices to other processes */
289       for (i=1; i<size; i++) {
290         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
291         ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
292         ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
293       }
294 
295       /* send numerical values to other processes */
296       for (i=1; i<size; i++) {
297         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
298         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
299       }
300       gmataa = gmata->a;
301       gmataj = gmata->j;
302 
303     } else {
304       /* receive row lengths */
305       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
306       /* receive column indices */
307       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
308       ierr = PetscMalloc2(nz,&gmataa,nz,&gmataj);CHKERRQ(ierr);
309       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
310       /* determine number diagonal and off-diagonal counts */
311       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
312       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
313       jj   = 0;
314       for (i=0; i<m; i++) {
315         for (j=0; j<dlens[i]; j++) {
316           if (gmataj[jj] < rstart) ld[i]++;
317           if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
318           jj++;
319         }
320       }
321       /* receive numerical values */
322       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
323       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
324     }
325     /* set preallocation */
326     for (i=0; i<m; i++) {
327       dlens[i] -= olens[i];
328     }
329     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
330     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
331 
332     for (i=0; i<m; i++) {
333       dlens[i] += olens[i];
334     }
335     cnt = 0;
336     for (i=0; i<m; i++) {
337       row  = rstart + i;
338       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
339       cnt += dlens[i];
340     }
341     if (rank) {
342       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
343     }
344     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
345     ierr = PetscFree(rowners);CHKERRQ(ierr);
346 
347     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
348 
349     *inmat = mat;
350   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
351     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
352     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
353     mat  = *inmat;
354     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
355     if (!rank) {
356       /* send numerical values to other processes */
357       gmata  = (Mat_SeqAIJ*) gmat->data;
358       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
359       gmataa = gmata->a;
360       for (i=1; i<size; i++) {
361         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
362         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
363       }
364       nz = gmata->i[rowners[1]]-gmata->i[rowners[0]];
365     } else {
366       /* receive numerical values from process 0*/
367       nz   = Ad->nz + Ao->nz;
368       ierr = PetscMalloc1(nz,&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
369       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
370     }
371     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
372     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
373     ad = Ad->a;
374     ao = Ao->a;
375     if (mat->rmap->n) {
376       i  = 0;
377       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
378       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
379     }
380     for (i=1; i<mat->rmap->n; i++) {
381       nz = Ao->i[i] - Ao->i[i-1] - ld[i-1] + ld[i]; ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
382       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
383     }
384     i--;
385     if (mat->rmap->n) {
386       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
387     }
388     if (rank) {
389       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
390     }
391   }
392   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
393   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
394   PetscFunctionReturn(0);
395 }
396 
397 /*
398   Local utility routine that creates a mapping from the global column
399 number to the local number in the off-diagonal part of the local
400 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
401 a slightly higher hash table cost; without it it is not scalable (each processor
402 has an order N integer array but is fast to acess.
403 */
404 #undef __FUNCT__
405 #define __FUNCT__ "MatCreateColmap_MPIAIJ_Private"
406 PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
407 {
408   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
409   PetscErrorCode ierr;
410   PetscInt       n = aij->B->cmap->n,i;
411 
412   PetscFunctionBegin;
413   if (!aij->garray) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPIAIJ Matrix was assembled but is missing garray");
414 #if defined(PETSC_USE_CTABLE)
415   ierr = PetscTableCreate(n,mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
416   for (i=0; i<n; i++) {
417     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1,INSERT_VALUES);CHKERRQ(ierr);
418   }
419 #else
420   ierr = PetscCalloc1(mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
421   ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N+1)*sizeof(PetscInt));CHKERRQ(ierr);
422   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
423 #endif
424   PetscFunctionReturn(0);
425 }
426 
427 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv,orow,ocol)     \
428 { \
429     if (col <= lastcol1)  low1 = 0;     \
430     else                 high1 = nrow1; \
431     lastcol1 = col;\
432     while (high1-low1 > 5) { \
433       t = (low1+high1)/2; \
434       if (rp1[t] > col) high1 = t; \
435       else              low1  = t; \
436     } \
437       for (_i=low1; _i<high1; _i++) { \
438         if (rp1[_i] > col) break; \
439         if (rp1[_i] == col) { \
440           if (addv == ADD_VALUES) ap1[_i] += value;   \
441           else                    ap1[_i] = value; \
442           goto a_noinsert; \
443         } \
444       }  \
445       if (value == 0.0 && ignorezeroentries) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
446       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}                \
447       if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero at global row/column (%D, %D) into matrix", orow, ocol); \
448       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
449       N = nrow1++ - 1; a->nz++; high1++; \
450       /* shift up all the later entries in this row */ \
451       for (ii=N; ii>=_i; ii--) { \
452         rp1[ii+1] = rp1[ii]; \
453         ap1[ii+1] = ap1[ii]; \
454       } \
455       rp1[_i] = col;  \
456       ap1[_i] = value;  \
457       A->nonzerostate++;\
458       a_noinsert: ; \
459       ailen[row] = nrow1; \
460 }
461 
462 
463 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv,orow,ocol) \
464   { \
465     if (col <= lastcol2) low2 = 0;                        \
466     else high2 = nrow2;                                   \
467     lastcol2 = col;                                       \
468     while (high2-low2 > 5) {                              \
469       t = (low2+high2)/2;                                 \
470       if (rp2[t] > col) high2 = t;                        \
471       else             low2  = t;                         \
472     }                                                     \
473     for (_i=low2; _i<high2; _i++) {                       \
474       if (rp2[_i] > col) break;                           \
475       if (rp2[_i] == col) {                               \
476         if (addv == ADD_VALUES) ap2[_i] += value;         \
477         else                    ap2[_i] = value;          \
478         goto b_noinsert;                                  \
479       }                                                   \
480     }                                                     \
481     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
482     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}                        \
483     if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero at global row/column (%D, %D) into matrix", orow, ocol); \
484     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
485     N = nrow2++ - 1; b->nz++; high2++;                    \
486     /* shift up all the later entries in this row */      \
487     for (ii=N; ii>=_i; ii--) {                            \
488       rp2[ii+1] = rp2[ii];                                \
489       ap2[ii+1] = ap2[ii];                                \
490     }                                                     \
491     rp2[_i] = col;                                        \
492     ap2[_i] = value;                                      \
493     B->nonzerostate++;                                    \
494     b_noinsert: ;                                         \
495     bilen[row] = nrow2;                                   \
496   }
497 
498 #undef __FUNCT__
499 #define __FUNCT__ "MatSetValuesRow_MPIAIJ"
500 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
501 {
502   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
503   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
504   PetscErrorCode ierr;
505   PetscInt       l,*garray = mat->garray,diag;
506 
507   PetscFunctionBegin;
508   /* code only works for square matrices A */
509 
510   /* find size of row to the left of the diagonal part */
511   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
512   row  = row - diag;
513   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
514     if (garray[b->j[b->i[row]+l]] > diag) break;
515   }
516   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
517 
518   /* diagonal part */
519   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
520 
521   /* right of diagonal part */
522   ierr = PetscMemcpy(b->a+b->i[row]+l,v+l+a->i[row+1]-a->i[row],(b->i[row+1]-b->i[row]-l)*sizeof(PetscScalar));CHKERRQ(ierr);
523   PetscFunctionReturn(0);
524 }
525 
526 #undef __FUNCT__
527 #define __FUNCT__ "MatSetValues_MPIAIJ"
528 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
529 {
530   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
531   PetscScalar    value;
532   PetscErrorCode ierr;
533   PetscInt       i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
534   PetscInt       cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
535   PetscBool      roworiented = aij->roworiented;
536 
537   /* Some Variables required in the macro */
538   Mat        A                 = aij->A;
539   Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
540   PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
541   MatScalar  *aa               = a->a;
542   PetscBool  ignorezeroentries = a->ignorezeroentries;
543   Mat        B                 = aij->B;
544   Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
545   PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
546   MatScalar  *ba               = b->a;
547 
548   PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
549   PetscInt  nonew;
550   MatScalar *ap1,*ap2;
551 
552   PetscFunctionBegin;
553   for (i=0; i<m; i++) {
554     if (im[i] < 0) continue;
555 #if defined(PETSC_USE_DEBUG)
556     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
557 #endif
558     if (im[i] >= rstart && im[i] < rend) {
559       row      = im[i] - rstart;
560       lastcol1 = -1;
561       rp1      = aj + ai[row];
562       ap1      = aa + ai[row];
563       rmax1    = aimax[row];
564       nrow1    = ailen[row];
565       low1     = 0;
566       high1    = nrow1;
567       lastcol2 = -1;
568       rp2      = bj + bi[row];
569       ap2      = ba + bi[row];
570       rmax2    = bimax[row];
571       nrow2    = bilen[row];
572       low2     = 0;
573       high2    = nrow2;
574 
575       for (j=0; j<n; j++) {
576         if (roworiented) value = v[i*n+j];
577         else             value = v[i+j*m];
578         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
579         if (in[j] >= cstart && in[j] < cend) {
580           col   = in[j] - cstart;
581           nonew = a->nonew;
582           MatSetValues_SeqAIJ_A_Private(row,col,value,addv,im[i],in[j]);
583         } else if (in[j] < 0) continue;
584 #if defined(PETSC_USE_DEBUG)
585         else if (in[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);
586 #endif
587         else {
588           if (mat->was_assembled) {
589             if (!aij->colmap) {
590               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
591             }
592 #if defined(PETSC_USE_CTABLE)
593             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
594             col--;
595 #else
596             col = aij->colmap[in[j]] - 1;
597 #endif
598             if (col < 0 && !((Mat_SeqAIJ*)(aij->B->data))->nonew) {
599               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
600               col  =  in[j];
601               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
602               B     = aij->B;
603               b     = (Mat_SeqAIJ*)B->data;
604               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
605               rp2   = bj + bi[row];
606               ap2   = ba + bi[row];
607               rmax2 = bimax[row];
608               nrow2 = bilen[row];
609               low2  = 0;
610               high2 = nrow2;
611               bm    = aij->B->rmap->n;
612               ba    = b->a;
613             } else if (col < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero at global row/column (%D, %D) into matrix", im[i], in[j]);
614           } else col = in[j];
615           nonew = b->nonew;
616           MatSetValues_SeqAIJ_B_Private(row,col,value,addv,im[i],in[j]);
617         }
618       }
619     } else {
620       if (mat->nooffprocentries) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Setting off process row %D even though MatSetOption(,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE) was set",im[i]);
621       if (!aij->donotstash) {
622         mat->assembled = PETSC_FALSE;
623         if (roworiented) {
624           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
625         } else {
626           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
627         }
628       }
629     }
630   }
631   PetscFunctionReturn(0);
632 }
633 
634 #undef __FUNCT__
635 #define __FUNCT__ "MatGetValues_MPIAIJ"
636 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
637 {
638   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
639   PetscErrorCode ierr;
640   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
641   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
642 
643   PetscFunctionBegin;
644   for (i=0; i<m; i++) {
645     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
646     if (idxm[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",idxm[i],mat->rmap->N-1);
647     if (idxm[i] >= rstart && idxm[i] < rend) {
648       row = idxm[i] - rstart;
649       for (j=0; j<n; j++) {
650         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
651         if (idxn[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",idxn[j],mat->cmap->N-1);
652         if (idxn[j] >= cstart && idxn[j] < cend) {
653           col  = idxn[j] - cstart;
654           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
655         } else {
656           if (!aij->colmap) {
657             ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
658           }
659 #if defined(PETSC_USE_CTABLE)
660           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
661           col--;
662 #else
663           col = aij->colmap[idxn[j]] - 1;
664 #endif
665           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
666           else {
667             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
668           }
669         }
670       }
671     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only local values currently supported");
672   }
673   PetscFunctionReturn(0);
674 }
675 
676 extern PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat,Vec,Vec);
677 
678 #undef __FUNCT__
679 #define __FUNCT__ "MatAssemblyBegin_MPIAIJ"
680 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
681 {
682   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
683   PetscErrorCode ierr;
684   PetscInt       nstash,reallocs;
685 
686   PetscFunctionBegin;
687   if (aij->donotstash || mat->nooffprocentries) PetscFunctionReturn(0);
688 
689   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
690   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
691   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
692   PetscFunctionReturn(0);
693 }
694 
695 #undef __FUNCT__
696 #define __FUNCT__ "MatAssemblyEnd_MPIAIJ"
697 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
698 {
699   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
700   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)aij->A->data;
701   PetscErrorCode ierr;
702   PetscMPIInt    n;
703   PetscInt       i,j,rstart,ncols,flg;
704   PetscInt       *row,*col;
705   PetscBool      other_disassembled;
706   PetscScalar    *val;
707 
708   /* do not use 'b = (Mat_SeqAIJ*)aij->B->data' as B can be reset in disassembly */
709 
710   PetscFunctionBegin;
711   if (!aij->donotstash && !mat->nooffprocentries) {
712     while (1) {
713       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
714       if (!flg) break;
715 
716       for (i=0; i<n; ) {
717         /* Now identify the consecutive vals belonging to the same row */
718         for (j=i,rstart=row[j]; j<n; j++) {
719           if (row[j] != rstart) break;
720         }
721         if (j < n) ncols = j-i;
722         else       ncols = n-i;
723         /* Now assemble all these values with a single function call */
724         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,mat->insertmode);CHKERRQ(ierr);
725 
726         i = j;
727       }
728     }
729     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
730   }
731   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
732   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
733 
734   /* determine if any processor has disassembled, if so we must
735      also disassemble ourselfs, in order that we may reassemble. */
736   /*
737      if nonzero structure of submatrix B cannot change then we know that
738      no processor disassembled thus we can skip this stuff
739   */
740   if (!((Mat_SeqAIJ*)aij->B->data)->nonew) {
741     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPIU_BOOL,MPI_PROD,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
742     if (mat->was_assembled && !other_disassembled) {
743       ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
744     }
745   }
746   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
747     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
748   }
749   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
750   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
751   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
752 
753   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
754 
755   aij->rowvalues = 0;
756 
757   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
758   if (a->inode.size) mat->ops->multdiagonalblock = MatMultDiagonalBlock_MPIAIJ;
759 
760   /* if no new nonzero locations are allowed in matrix then only set the matrix state the first time through */
761   if ((!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) || !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
762     PetscObjectState state = aij->A->nonzerostate + aij->B->nonzerostate;
763     ierr = MPI_Allreduce(&state,&mat->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
764   }
765   PetscFunctionReturn(0);
766 }
767 
768 #undef __FUNCT__
769 #define __FUNCT__ "MatZeroEntries_MPIAIJ"
770 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
771 {
772   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
773   PetscErrorCode ierr;
774 
775   PetscFunctionBegin;
776   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
777   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
778   PetscFunctionReturn(0);
779 }
780 
781 #undef __FUNCT__
782 #define __FUNCT__ "MatZeroRows_MPIAIJ"
783 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
784 {
785   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
786   PetscInt      *owners = A->rmap->range;
787   PetscInt       n      = A->rmap->n;
788   PetscSF        sf;
789   PetscInt      *lrows;
790   PetscSFNode   *rrows;
791   PetscInt       r, p = 0, len = 0;
792   PetscErrorCode ierr;
793 
794   PetscFunctionBegin;
795   /* Create SF where leaves are input rows and roots are owned rows */
796   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
797   for (r = 0; r < n; ++r) lrows[r] = -1;
798   if (!A->nooffproczerorows) {ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);}
799   for (r = 0; r < N; ++r) {
800     const PetscInt idx   = rows[r];
801     if (idx < 0 || A->rmap->N <= idx) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row %D out of range [0,%D)",idx,A->rmap->N);
802     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
803       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
804     }
805     if (A->nooffproczerorows) {
806       if (p != mat->rank) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"MAT_NO_OFF_PROC_ZERO_ROWS set, but row %D is not owned by rank %d",idx,mat->rank);
807       lrows[len++] = idx - owners[p];
808     } else {
809       rrows[r].rank = p;
810       rrows[r].index = rows[r] - owners[p];
811     }
812   }
813   if (!A->nooffproczerorows) {
814     ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
815     ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
816     /* Collect flags for rows to be zeroed */
817     ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt*)rows, lrows, MPI_LOR);CHKERRQ(ierr);
818     ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt*)rows, lrows, MPI_LOR);CHKERRQ(ierr);
819     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
820     /* Compress and put in row numbers */
821     for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
822   }
823   /* fix right hand side if needed */
824   if (x && b) {
825     const PetscScalar *xx;
826     PetscScalar       *bb;
827 
828     ierr = VecGetArrayRead(x, &xx);CHKERRQ(ierr);
829     ierr = VecGetArray(b, &bb);CHKERRQ(ierr);
830     for (r = 0; r < len; ++r) bb[lrows[r]] = diag*xx[lrows[r]];
831     ierr = VecRestoreArrayRead(x, &xx);CHKERRQ(ierr);
832     ierr = VecRestoreArray(b, &bb);CHKERRQ(ierr);
833   }
834   /* Must zero l->B before l->A because the (diag) case below may put values into l->B*/
835   ierr = MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
836   if ((diag != 0.0) && (mat->A->rmap->N == mat->A->cmap->N)) {
837     ierr = MatZeroRows(mat->A, len, lrows, diag, NULL, NULL);CHKERRQ(ierr);
838   } else if (diag != 0.0) {
839     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
840     if (((Mat_SeqAIJ *) mat->A->data)->nonew) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "MatZeroRows() on rectangular matrices cannot be used with the Mat options\nMAT_NEW_NONZERO_LOCATIONS,MAT_NEW_NONZERO_LOCATION_ERR,MAT_NEW_NONZERO_ALLOCATION_ERR");
841     for (r = 0; r < len; ++r) {
842       const PetscInt row = lrows[r] + A->rmap->rstart;
843       ierr = MatSetValues(A, 1, &row, 1, &row, &diag, INSERT_VALUES);CHKERRQ(ierr);
844     }
845     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
846     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
847   } else {
848     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
849   }
850   ierr = PetscFree(lrows);CHKERRQ(ierr);
851 
852   /* only change matrix nonzero state if pattern was allowed to be changed */
853   if (!((Mat_SeqAIJ*)(mat->A->data))->keepnonzeropattern) {
854     PetscObjectState state = mat->A->nonzerostate + mat->B->nonzerostate;
855     ierr = MPI_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
856   }
857   PetscFunctionReturn(0);
858 }
859 
860 #undef __FUNCT__
861 #define __FUNCT__ "MatZeroRowsColumns_MPIAIJ"
862 PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
863 {
864   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
865   PetscErrorCode    ierr;
866   PetscMPIInt       n = A->rmap->n;
867   PetscInt          i,j,r,m,p = 0,len = 0;
868   PetscInt          *lrows,*owners = A->rmap->range;
869   PetscSFNode       *rrows;
870   PetscSF           sf;
871   const PetscScalar *xx;
872   PetscScalar       *bb,*mask;
873   Vec               xmask,lmask;
874   Mat_SeqAIJ        *aij = (Mat_SeqAIJ*)l->B->data;
875   const PetscInt    *aj, *ii,*ridx;
876   PetscScalar       *aa;
877 
878   PetscFunctionBegin;
879   /* Create SF where leaves are input rows and roots are owned rows */
880   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
881   for (r = 0; r < n; ++r) lrows[r] = -1;
882   ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);
883   for (r = 0; r < N; ++r) {
884     const PetscInt idx   = rows[r];
885     if (idx < 0 || A->rmap->N <= idx) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row %D out of range [0,%D)",idx,A->rmap->N);
886     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
887       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
888     }
889     rrows[r].rank  = p;
890     rrows[r].index = rows[r] - owners[p];
891   }
892   ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
893   ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
894   /* Collect flags for rows to be zeroed */
895   ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
896   ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
897   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
898   /* Compress and put in row numbers */
899   for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
900   /* zero diagonal part of matrix */
901   ierr = MatZeroRowsColumns(l->A,len,lrows,diag,x,b);CHKERRQ(ierr);
902   /* handle off diagonal part of matrix */
903   ierr = MatCreateVecs(A,&xmask,NULL);CHKERRQ(ierr);
904   ierr = VecDuplicate(l->lvec,&lmask);CHKERRQ(ierr);
905   ierr = VecGetArray(xmask,&bb);CHKERRQ(ierr);
906   for (i=0; i<len; i++) bb[lrows[i]] = 1;
907   ierr = VecRestoreArray(xmask,&bb);CHKERRQ(ierr);
908   ierr = VecScatterBegin(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
909   ierr = VecScatterEnd(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
910   ierr = VecDestroy(&xmask);CHKERRQ(ierr);
911   if (x) {
912     ierr = VecScatterBegin(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
913     ierr = VecScatterEnd(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
914     ierr = VecGetArrayRead(l->lvec,&xx);CHKERRQ(ierr);
915     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
916   }
917   ierr = VecGetArray(lmask,&mask);CHKERRQ(ierr);
918   /* remove zeroed rows of off diagonal matrix */
919   ii = aij->i;
920   for (i=0; i<len; i++) {
921     ierr = PetscMemzero(aij->a + ii[lrows[i]],(ii[lrows[i]+1] - ii[lrows[i]])*sizeof(PetscScalar));CHKERRQ(ierr);
922   }
923   /* loop over all elements of off process part of matrix zeroing removed columns*/
924   if (aij->compressedrow.use) {
925     m    = aij->compressedrow.nrows;
926     ii   = aij->compressedrow.i;
927     ridx = aij->compressedrow.rindex;
928     for (i=0; i<m; i++) {
929       n  = ii[i+1] - ii[i];
930       aj = aij->j + ii[i];
931       aa = aij->a + ii[i];
932 
933       for (j=0; j<n; j++) {
934         if (PetscAbsScalar(mask[*aj])) {
935           if (b) bb[*ridx] -= *aa*xx[*aj];
936           *aa = 0.0;
937         }
938         aa++;
939         aj++;
940       }
941       ridx++;
942     }
943   } else { /* do not use compressed row format */
944     m = l->B->rmap->n;
945     for (i=0; i<m; i++) {
946       n  = ii[i+1] - ii[i];
947       aj = aij->j + ii[i];
948       aa = aij->a + ii[i];
949       for (j=0; j<n; j++) {
950         if (PetscAbsScalar(mask[*aj])) {
951           if (b) bb[i] -= *aa*xx[*aj];
952           *aa = 0.0;
953         }
954         aa++;
955         aj++;
956       }
957     }
958   }
959   if (x) {
960     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
961     ierr = VecRestoreArrayRead(l->lvec,&xx);CHKERRQ(ierr);
962   }
963   ierr = VecRestoreArray(lmask,&mask);CHKERRQ(ierr);
964   ierr = VecDestroy(&lmask);CHKERRQ(ierr);
965   ierr = PetscFree(lrows);CHKERRQ(ierr);
966 
967   /* only change matrix nonzero state if pattern was allowed to be changed */
968   if (!((Mat_SeqAIJ*)(l->A->data))->keepnonzeropattern) {
969     PetscObjectState state = l->A->nonzerostate + l->B->nonzerostate;
970     ierr = MPI_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
971   }
972   PetscFunctionReturn(0);
973 }
974 
975 #undef __FUNCT__
976 #define __FUNCT__ "MatMult_MPIAIJ"
977 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
978 {
979   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
980   PetscErrorCode ierr;
981   PetscInt       nt;
982 
983   PetscFunctionBegin;
984   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
985   if (nt != A->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Incompatible partition of A (%D) and xx (%D)",A->cmap->n,nt);
986   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
987   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
988   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
989   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
990   PetscFunctionReturn(0);
991 }
992 
993 #undef __FUNCT__
994 #define __FUNCT__ "MatMultDiagonalBlock_MPIAIJ"
995 PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A,Vec bb,Vec xx)
996 {
997   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
998   PetscErrorCode ierr;
999 
1000   PetscFunctionBegin;
1001   ierr = MatMultDiagonalBlock(a->A,bb,xx);CHKERRQ(ierr);
1002   PetscFunctionReturn(0);
1003 }
1004 
1005 #undef __FUNCT__
1006 #define __FUNCT__ "MatMultAdd_MPIAIJ"
1007 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1008 {
1009   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1010   PetscErrorCode ierr;
1011 
1012   PetscFunctionBegin;
1013   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1014   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1015   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1016   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
1017   PetscFunctionReturn(0);
1018 }
1019 
1020 #undef __FUNCT__
1021 #define __FUNCT__ "MatMultTranspose_MPIAIJ"
1022 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
1023 {
1024   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1025   PetscErrorCode ierr;
1026   PetscBool      merged;
1027 
1028   PetscFunctionBegin;
1029   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
1030   /* do nondiagonal part */
1031   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1032   if (!merged) {
1033     /* send it on its way */
1034     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1035     /* do local part */
1036     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1037     /* receive remote parts: note this assumes the values are not actually */
1038     /* added in yy until the next line, */
1039     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1040   } else {
1041     /* do local part */
1042     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1043     /* send it on its way */
1044     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1045     /* values actually were received in the Begin() but we need to call this nop */
1046     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1047   }
1048   PetscFunctionReturn(0);
1049 }
1050 
1051 #undef __FUNCT__
1052 #define __FUNCT__ "MatIsTranspose_MPIAIJ"
1053 PetscErrorCode  MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscBool  *f)
1054 {
1055   MPI_Comm       comm;
1056   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ*) Amat->data, *Bij;
1057   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
1058   IS             Me,Notme;
1059   PetscErrorCode ierr;
1060   PetscInt       M,N,first,last,*notme,i;
1061   PetscMPIInt    size;
1062 
1063   PetscFunctionBegin;
1064   /* Easy test: symmetric diagonal block */
1065   Bij  = (Mat_MPIAIJ*) Bmat->data; Bdia = Bij->A;
1066   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
1067   if (!*f) PetscFunctionReturn(0);
1068   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1069   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1070   if (size == 1) PetscFunctionReturn(0);
1071 
1072   /* Hard test: off-diagonal block. This takes a MatGetSubMatrix. */
1073   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
1074   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
1075   ierr = PetscMalloc1(N-last+first,&notme);CHKERRQ(ierr);
1076   for (i=0; i<first; i++) notme[i] = i;
1077   for (i=last; i<M; i++) notme[i-last+first] = i;
1078   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,PETSC_COPY_VALUES,&Notme);CHKERRQ(ierr);
1079   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
1080   ierr = MatGetSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
1081   Aoff = Aoffs[0];
1082   ierr = MatGetSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
1083   Boff = Boffs[0];
1084   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
1085   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
1086   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
1087   ierr = ISDestroy(&Me);CHKERRQ(ierr);
1088   ierr = ISDestroy(&Notme);CHKERRQ(ierr);
1089   ierr = PetscFree(notme);CHKERRQ(ierr);
1090   PetscFunctionReturn(0);
1091 }
1092 
1093 #undef __FUNCT__
1094 #define __FUNCT__ "MatMultTransposeAdd_MPIAIJ"
1095 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1096 {
1097   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1098   PetscErrorCode ierr;
1099 
1100   PetscFunctionBegin;
1101   /* do nondiagonal part */
1102   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1103   /* send it on its way */
1104   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1105   /* do local part */
1106   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1107   /* receive remote parts */
1108   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1109   PetscFunctionReturn(0);
1110 }
1111 
1112 /*
1113   This only works correctly for square matrices where the subblock A->A is the
1114    diagonal block
1115 */
1116 #undef __FUNCT__
1117 #define __FUNCT__ "MatGetDiagonal_MPIAIJ"
1118 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
1119 {
1120   PetscErrorCode ierr;
1121   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1122 
1123   PetscFunctionBegin;
1124   if (A->rmap->N != A->cmap->N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
1125   if (A->rmap->rstart != A->cmap->rstart || A->rmap->rend != A->cmap->rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"row partition must equal col partition");
1126   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1127   PetscFunctionReturn(0);
1128 }
1129 
1130 #undef __FUNCT__
1131 #define __FUNCT__ "MatScale_MPIAIJ"
1132 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
1133 {
1134   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1135   PetscErrorCode ierr;
1136 
1137   PetscFunctionBegin;
1138   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
1139   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
1140   PetscFunctionReturn(0);
1141 }
1142 
1143 #undef __FUNCT__
1144 #define __FUNCT__ "MatDestroy_MPIAIJ"
1145 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
1146 {
1147   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1148   PetscErrorCode ierr;
1149 
1150   PetscFunctionBegin;
1151 #if defined(PETSC_USE_LOG)
1152   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
1153 #endif
1154   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
1155   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
1156   ierr = MatDestroy(&aij->A);CHKERRQ(ierr);
1157   ierr = MatDestroy(&aij->B);CHKERRQ(ierr);
1158 #if defined(PETSC_USE_CTABLE)
1159   ierr = PetscTableDestroy(&aij->colmap);CHKERRQ(ierr);
1160 #else
1161   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
1162 #endif
1163   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
1164   ierr = VecDestroy(&aij->lvec);CHKERRQ(ierr);
1165   ierr = VecScatterDestroy(&aij->Mvctx);CHKERRQ(ierr);
1166   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
1167   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
1168   ierr = PetscFree(mat->data);CHKERRQ(ierr);
1169 
1170   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
1171   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C",NULL);CHKERRQ(ierr);
1172   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C",NULL);CHKERRQ(ierr);
1173   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatGetDiagonalBlock_C",NULL);CHKERRQ(ierr);
1174   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C",NULL);CHKERRQ(ierr);
1175   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C",NULL);CHKERRQ(ierr);
1176   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C",NULL);CHKERRQ(ierr);
1177   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C",NULL);CHKERRQ(ierr);
1178   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_mpisbaij_C",NULL);CHKERRQ(ierr);
1179 #if defined(PETSC_HAVE_ELEMENTAL)
1180   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_elemental_C",NULL);CHKERRQ(ierr);
1181 #endif
1182   PetscFunctionReturn(0);
1183 }
1184 
1185 #undef __FUNCT__
1186 #define __FUNCT__ "MatView_MPIAIJ_Binary"
1187 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
1188 {
1189   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1190   Mat_SeqAIJ     *A   = (Mat_SeqAIJ*)aij->A->data;
1191   Mat_SeqAIJ     *B   = (Mat_SeqAIJ*)aij->B->data;
1192   PetscErrorCode ierr;
1193   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
1194   int            fd;
1195   PetscInt       nz,header[4],*row_lengths,*range=0,rlen,i;
1196   PetscInt       nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz = 0;
1197   PetscScalar    *column_values;
1198   PetscInt       message_count,flowcontrolcount;
1199   FILE           *file;
1200 
1201   PetscFunctionBegin;
1202   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1203   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
1204   nz   = A->nz + B->nz;
1205   ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
1206   if (!rank) {
1207     header[0] = MAT_FILE_CLASSID;
1208     header[1] = mat->rmap->N;
1209     header[2] = mat->cmap->N;
1210 
1211     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1212     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1213     /* get largest number of rows any processor has */
1214     rlen  = mat->rmap->n;
1215     range = mat->rmap->range;
1216     for (i=1; i<size; i++) rlen = PetscMax(rlen,range[i+1] - range[i]);
1217   } else {
1218     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1219     rlen = mat->rmap->n;
1220   }
1221 
1222   /* load up the local row counts */
1223   ierr = PetscMalloc1(rlen+1,&row_lengths);CHKERRQ(ierr);
1224   for (i=0; i<mat->rmap->n; i++) row_lengths[i] = A->i[i+1] - A->i[i] + B->i[i+1] - B->i[i];
1225 
1226   /* store the row lengths to the file */
1227   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1228   if (!rank) {
1229     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1230     for (i=1; i<size; i++) {
1231       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1232       rlen = range[i+1] - range[i];
1233       ierr = MPIULong_Recv(row_lengths,rlen,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1234       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1235     }
1236     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1237   } else {
1238     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1239     ierr = MPIULong_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1240     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1241   }
1242   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
1243 
1244   /* load up the local column indices */
1245   nzmax = nz; /* th processor needs space a largest processor needs */
1246   ierr  = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1247   ierr  = PetscMalloc1(nzmax+1,&column_indices);CHKERRQ(ierr);
1248   cnt   = 0;
1249   for (i=0; i<mat->rmap->n; i++) {
1250     for (j=B->i[i]; j<B->i[i+1]; j++) {
1251       if ((col = garray[B->j[j]]) > cstart) break;
1252       column_indices[cnt++] = col;
1253     }
1254     for (k=A->i[i]; k<A->i[i+1]; k++) column_indices[cnt++] = A->j[k] + cstart;
1255     for (; j<B->i[i+1]; j++) column_indices[cnt++] = garray[B->j[j]];
1256   }
1257   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1258 
1259   /* store the column indices to the file */
1260   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1261   if (!rank) {
1262     MPI_Status status;
1263     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1264     for (i=1; i<size; i++) {
1265       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1266       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1267       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1268       ierr = MPIULong_Recv(column_indices,rnz,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1269       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1270     }
1271     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1272   } else {
1273     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1274     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1275     ierr = MPIULong_Send(column_indices,nz,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1276     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1277   }
1278   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1279 
1280   /* load up the local column values */
1281   ierr = PetscMalloc1(nzmax+1,&column_values);CHKERRQ(ierr);
1282   cnt  = 0;
1283   for (i=0; i<mat->rmap->n; i++) {
1284     for (j=B->i[i]; j<B->i[i+1]; j++) {
1285       if (garray[B->j[j]] > cstart) break;
1286       column_values[cnt++] = B->a[j];
1287     }
1288     for (k=A->i[i]; k<A->i[i+1]; k++) column_values[cnt++] = A->a[k];
1289     for (; j<B->i[i+1]; j++) column_values[cnt++] = B->a[j];
1290   }
1291   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1292 
1293   /* store the column values to the file */
1294   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1295   if (!rank) {
1296     MPI_Status status;
1297     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1298     for (i=1; i<size; i++) {
1299       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1300       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1301       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1302       ierr = MPIULong_Recv(column_values,rnz,MPIU_SCALAR,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1303       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1304     }
1305     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1306   } else {
1307     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1308     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1309     ierr = MPIULong_Send(column_values,nz,MPIU_SCALAR,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1310     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1311   }
1312   ierr = PetscFree(column_values);CHKERRQ(ierr);
1313 
1314   ierr = PetscViewerBinaryGetInfoPointer(viewer,&file);CHKERRQ(ierr);
1315   if (file) fprintf(file,"-matload_block_size %d\n",(int)PetscAbs(mat->rmap->bs));
1316   PetscFunctionReturn(0);
1317 }
1318 
1319 #include <petscdraw.h>
1320 #undef __FUNCT__
1321 #define __FUNCT__ "MatView_MPIAIJ_ASCIIorDraworSocket"
1322 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1323 {
1324   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1325   PetscErrorCode    ierr;
1326   PetscMPIInt       rank = aij->rank,size = aij->size;
1327   PetscBool         isdraw,iascii,isbinary;
1328   PetscViewer       sviewer;
1329   PetscViewerFormat format;
1330 
1331   PetscFunctionBegin;
1332   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1333   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1334   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1335   if (iascii) {
1336     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1337     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1338       MatInfo   info;
1339       PetscBool inodes;
1340 
1341       ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1342       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1343       ierr = MatInodeGetInodeSizes(aij->A,NULL,(PetscInt**)&inodes,NULL);CHKERRQ(ierr);
1344       ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr);
1345       if (!inodes) {
1346         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1347                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1348       } else {
1349         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1350                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1351       }
1352       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1353       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1354       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1355       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1356       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1357       ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr);
1358       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1359       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1360       PetscFunctionReturn(0);
1361     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1362       PetscInt inodecount,inodelimit,*inodes;
1363       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1364       if (inodes) {
1365         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1366       } else {
1367         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1368       }
1369       PetscFunctionReturn(0);
1370     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1371       PetscFunctionReturn(0);
1372     }
1373   } else if (isbinary) {
1374     if (size == 1) {
1375       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1376       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1377     } else {
1378       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1379     }
1380     PetscFunctionReturn(0);
1381   } else if (isdraw) {
1382     PetscDraw draw;
1383     PetscBool isnull;
1384     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1385     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1386   }
1387 
1388   {
1389     /* assemble the entire matrix onto first processor. */
1390     Mat        A;
1391     Mat_SeqAIJ *Aloc;
1392     PetscInt   M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1393     MatScalar  *a;
1394 
1395     ierr = MatCreate(PetscObjectComm((PetscObject)mat),&A);CHKERRQ(ierr);
1396     if (!rank) {
1397       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1398     } else {
1399       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1400     }
1401     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1402     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1403     ierr = MatMPIAIJSetPreallocation(A,0,NULL,0,NULL);CHKERRQ(ierr);
1404     ierr = MatSetOption(A,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
1405     ierr = PetscLogObjectParent((PetscObject)mat,(PetscObject)A);CHKERRQ(ierr);
1406 
1407     /* copy over the A part */
1408     Aloc = (Mat_SeqAIJ*)aij->A->data;
1409     m    = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1410     row  = mat->rmap->rstart;
1411     for (i=0; i<ai[m]; i++) aj[i] += mat->cmap->rstart;
1412     for (i=0; i<m; i++) {
1413       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1414       row++;
1415       a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1416     }
1417     aj = Aloc->j;
1418     for (i=0; i<ai[m]; i++) aj[i] -= mat->cmap->rstart;
1419 
1420     /* copy over the B part */
1421     Aloc = (Mat_SeqAIJ*)aij->B->data;
1422     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1423     row  = mat->rmap->rstart;
1424     ierr = PetscMalloc1(ai[m]+1,&cols);CHKERRQ(ierr);
1425     ct   = cols;
1426     for (i=0; i<ai[m]; i++) cols[i] = aij->garray[aj[i]];
1427     for (i=0; i<m; i++) {
1428       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1429       row++;
1430       a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1431     }
1432     ierr = PetscFree(ct);CHKERRQ(ierr);
1433     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1434     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1435     /*
1436        Everyone has to call to draw the matrix since the graphics waits are
1437        synchronized across all processors that share the PetscDraw object
1438     */
1439     ierr = PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer);CHKERRQ(ierr);
1440     if (!rank) {
1441       ierr = PetscObjectSetName((PetscObject)((Mat_MPIAIJ*)(A->data))->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1442       ierr = MatView_SeqAIJ(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1443     }
1444     ierr = PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer);CHKERRQ(ierr);
1445     ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1446     ierr = MatDestroy(&A);CHKERRQ(ierr);
1447   }
1448   PetscFunctionReturn(0);
1449 }
1450 
1451 #undef __FUNCT__
1452 #define __FUNCT__ "MatView_MPIAIJ"
1453 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1454 {
1455   PetscErrorCode ierr;
1456   PetscBool      iascii,isdraw,issocket,isbinary;
1457 
1458   PetscFunctionBegin;
1459   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1460   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1461   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1462   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSOCKET,&issocket);CHKERRQ(ierr);
1463   if (iascii || isdraw || isbinary || issocket) {
1464     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1465   }
1466   PetscFunctionReturn(0);
1467 }
1468 
1469 #undef __FUNCT__
1470 #define __FUNCT__ "MatSOR_MPIAIJ"
1471 PetscErrorCode MatSOR_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1472 {
1473   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1474   PetscErrorCode ierr;
1475   Vec            bb1 = 0;
1476   PetscBool      hasop;
1477 
1478   PetscFunctionBegin;
1479   if (flag == SOR_APPLY_UPPER) {
1480     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1481     PetscFunctionReturn(0);
1482   }
1483 
1484   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) {
1485     ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1486   }
1487 
1488   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP) {
1489     if (flag & SOR_ZERO_INITIAL_GUESS) {
1490       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1491       its--;
1492     }
1493 
1494     while (its--) {
1495       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1496       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1497 
1498       /* update rhs: bb1 = bb - B*x */
1499       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1500       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1501 
1502       /* local sweep */
1503       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1504     }
1505   } else if (flag & SOR_LOCAL_FORWARD_SWEEP) {
1506     if (flag & SOR_ZERO_INITIAL_GUESS) {
1507       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1508       its--;
1509     }
1510     while (its--) {
1511       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1512       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1513 
1514       /* update rhs: bb1 = bb - B*x */
1515       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1516       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1517 
1518       /* local sweep */
1519       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1520     }
1521   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP) {
1522     if (flag & SOR_ZERO_INITIAL_GUESS) {
1523       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1524       its--;
1525     }
1526     while (its--) {
1527       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1528       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1529 
1530       /* update rhs: bb1 = bb - B*x */
1531       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1532       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1533 
1534       /* local sweep */
1535       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1536     }
1537   } else if (flag & SOR_EISENSTAT) {
1538     Vec xx1;
1539 
1540     ierr = VecDuplicate(bb,&xx1);CHKERRQ(ierr);
1541     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP),fshift,lits,1,xx);CHKERRQ(ierr);
1542 
1543     ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1544     ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1545     if (!mat->diag) {
1546       ierr = MatCreateVecs(matin,&mat->diag,NULL);CHKERRQ(ierr);
1547       ierr = MatGetDiagonal(matin,mat->diag);CHKERRQ(ierr);
1548     }
1549     ierr = MatHasOperation(matin,MATOP_MULT_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr);
1550     if (hasop) {
1551       ierr = MatMultDiagonalBlock(matin,xx,bb1);CHKERRQ(ierr);
1552     } else {
1553       ierr = VecPointwiseMult(bb1,mat->diag,xx);CHKERRQ(ierr);
1554     }
1555     ierr = VecAYPX(bb1,(omega-2.0)/omega,bb);CHKERRQ(ierr);
1556 
1557     ierr = MatMultAdd(mat->B,mat->lvec,bb1,bb1);CHKERRQ(ierr);
1558 
1559     /* local sweep */
1560     ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP),fshift,lits,1,xx1);CHKERRQ(ierr);
1561     ierr = VecAXPY(xx,1.0,xx1);CHKERRQ(ierr);
1562     ierr = VecDestroy(&xx1);CHKERRQ(ierr);
1563   } else SETERRQ(PetscObjectComm((PetscObject)matin),PETSC_ERR_SUP,"Parallel SOR not supported");
1564 
1565   ierr = VecDestroy(&bb1);CHKERRQ(ierr);
1566   PetscFunctionReturn(0);
1567 }
1568 
1569 #undef __FUNCT__
1570 #define __FUNCT__ "MatPermute_MPIAIJ"
1571 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1572 {
1573   Mat            aA,aB,Aperm;
1574   const PetscInt *rwant,*cwant,*gcols,*ai,*bi,*aj,*bj;
1575   PetscScalar    *aa,*ba;
1576   PetscInt       i,j,m,n,ng,anz,bnz,*dnnz,*onnz,*tdnnz,*tonnz,*rdest,*cdest,*work,*gcdest;
1577   PetscSF        rowsf,sf;
1578   IS             parcolp = NULL;
1579   PetscBool      done;
1580   PetscErrorCode ierr;
1581 
1582   PetscFunctionBegin;
1583   ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr);
1584   ierr = ISGetIndices(rowp,&rwant);CHKERRQ(ierr);
1585   ierr = ISGetIndices(colp,&cwant);CHKERRQ(ierr);
1586   ierr = PetscMalloc3(PetscMax(m,n),&work,m,&rdest,n,&cdest);CHKERRQ(ierr);
1587 
1588   /* Invert row permutation to find out where my rows should go */
1589   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&rowsf);CHKERRQ(ierr);
1590   ierr = PetscSFSetGraphLayout(rowsf,A->rmap,A->rmap->n,NULL,PETSC_OWN_POINTER,rwant);CHKERRQ(ierr);
1591   ierr = PetscSFSetFromOptions(rowsf);CHKERRQ(ierr);
1592   for (i=0; i<m; i++) work[i] = A->rmap->rstart + i;
1593   ierr = PetscSFReduceBegin(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1594   ierr = PetscSFReduceEnd(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1595 
1596   /* Invert column permutation to find out where my columns should go */
1597   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1598   ierr = PetscSFSetGraphLayout(sf,A->cmap,A->cmap->n,NULL,PETSC_OWN_POINTER,cwant);CHKERRQ(ierr);
1599   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1600   for (i=0; i<n; i++) work[i] = A->cmap->rstart + i;
1601   ierr = PetscSFReduceBegin(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1602   ierr = PetscSFReduceEnd(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1603   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1604 
1605   ierr = ISRestoreIndices(rowp,&rwant);CHKERRQ(ierr);
1606   ierr = ISRestoreIndices(colp,&cwant);CHKERRQ(ierr);
1607   ierr = MatMPIAIJGetSeqAIJ(A,&aA,&aB,&gcols);CHKERRQ(ierr);
1608 
1609   /* Find out where my gcols should go */
1610   ierr = MatGetSize(aB,NULL,&ng);CHKERRQ(ierr);
1611   ierr = PetscMalloc1(ng,&gcdest);CHKERRQ(ierr);
1612   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1613   ierr = PetscSFSetGraphLayout(sf,A->cmap,ng,NULL,PETSC_OWN_POINTER,gcols);CHKERRQ(ierr);
1614   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1615   ierr = PetscSFBcastBegin(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1616   ierr = PetscSFBcastEnd(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1617   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1618 
1619   ierr = PetscCalloc4(m,&dnnz,m,&onnz,m,&tdnnz,m,&tonnz);CHKERRQ(ierr);
1620   ierr = MatGetRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1621   ierr = MatGetRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1622   for (i=0; i<m; i++) {
1623     PetscInt row = rdest[i],rowner;
1624     ierr = PetscLayoutFindOwner(A->rmap,row,&rowner);CHKERRQ(ierr);
1625     for (j=ai[i]; j<ai[i+1]; j++) {
1626       PetscInt cowner,col = cdest[aj[j]];
1627       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr); /* Could build an index for the columns to eliminate this search */
1628       if (rowner == cowner) dnnz[i]++;
1629       else onnz[i]++;
1630     }
1631     for (j=bi[i]; j<bi[i+1]; j++) {
1632       PetscInt cowner,col = gcdest[bj[j]];
1633       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr);
1634       if (rowner == cowner) dnnz[i]++;
1635       else onnz[i]++;
1636     }
1637   }
1638   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1639   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1640   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1641   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1642   ierr = PetscSFDestroy(&rowsf);CHKERRQ(ierr);
1643 
1644   ierr = MatCreateAIJ(PetscObjectComm((PetscObject)A),A->rmap->n,A->cmap->n,A->rmap->N,A->cmap->N,0,tdnnz,0,tonnz,&Aperm);CHKERRQ(ierr);
1645   ierr = MatSeqAIJGetArray(aA,&aa);CHKERRQ(ierr);
1646   ierr = MatSeqAIJGetArray(aB,&ba);CHKERRQ(ierr);
1647   for (i=0; i<m; i++) {
1648     PetscInt *acols = dnnz,*bcols = onnz; /* Repurpose now-unneeded arrays */
1649     PetscInt j0,rowlen;
1650     rowlen = ai[i+1] - ai[i];
1651     for (j0=j=0; j<rowlen; j0=j) { /* rowlen could be larger than number of rows m, so sum in batches */
1652       for ( ; j<PetscMin(rowlen,j0+m); j++) acols[j-j0] = cdest[aj[ai[i]+j]];
1653       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,acols,aa+ai[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1654     }
1655     rowlen = bi[i+1] - bi[i];
1656     for (j0=j=0; j<rowlen; j0=j) {
1657       for ( ; j<PetscMin(rowlen,j0+m); j++) bcols[j-j0] = gcdest[bj[bi[i]+j]];
1658       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,bcols,ba+bi[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1659     }
1660   }
1661   ierr = MatAssemblyBegin(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1662   ierr = MatAssemblyEnd(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1663   ierr = MatRestoreRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1664   ierr = MatRestoreRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1665   ierr = MatSeqAIJRestoreArray(aA,&aa);CHKERRQ(ierr);
1666   ierr = MatSeqAIJRestoreArray(aB,&ba);CHKERRQ(ierr);
1667   ierr = PetscFree4(dnnz,onnz,tdnnz,tonnz);CHKERRQ(ierr);
1668   ierr = PetscFree3(work,rdest,cdest);CHKERRQ(ierr);
1669   ierr = PetscFree(gcdest);CHKERRQ(ierr);
1670   if (parcolp) {ierr = ISDestroy(&colp);CHKERRQ(ierr);}
1671   *B = Aperm;
1672   PetscFunctionReturn(0);
1673 }
1674 
1675 #undef __FUNCT__
1676 #define __FUNCT__ "MatGetGhosts_MPIAIJ"
1677 PetscErrorCode  MatGetGhosts_MPIAIJ(Mat mat,PetscInt *nghosts,const PetscInt *ghosts[])
1678 {
1679   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1680   PetscErrorCode ierr;
1681 
1682   PetscFunctionBegin;
1683   ierr = MatGetSize(aij->B,NULL,nghosts);CHKERRQ(ierr);
1684   if (ghosts) *ghosts = aij->garray;
1685   PetscFunctionReturn(0);
1686 }
1687 
1688 #undef __FUNCT__
1689 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1690 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1691 {
1692   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1693   Mat            A    = mat->A,B = mat->B;
1694   PetscErrorCode ierr;
1695   PetscReal      isend[5],irecv[5];
1696 
1697   PetscFunctionBegin;
1698   info->block_size = 1.0;
1699   ierr             = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1700 
1701   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1702   isend[3] = info->memory;  isend[4] = info->mallocs;
1703 
1704   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1705 
1706   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1707   isend[3] += info->memory;  isend[4] += info->mallocs;
1708   if (flag == MAT_LOCAL) {
1709     info->nz_used      = isend[0];
1710     info->nz_allocated = isend[1];
1711     info->nz_unneeded  = isend[2];
1712     info->memory       = isend[3];
1713     info->mallocs      = isend[4];
1714   } else if (flag == MAT_GLOBAL_MAX) {
1715     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1716 
1717     info->nz_used      = irecv[0];
1718     info->nz_allocated = irecv[1];
1719     info->nz_unneeded  = irecv[2];
1720     info->memory       = irecv[3];
1721     info->mallocs      = irecv[4];
1722   } else if (flag == MAT_GLOBAL_SUM) {
1723     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1724 
1725     info->nz_used      = irecv[0];
1726     info->nz_allocated = irecv[1];
1727     info->nz_unneeded  = irecv[2];
1728     info->memory       = irecv[3];
1729     info->mallocs      = irecv[4];
1730   }
1731   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1732   info->fill_ratio_needed = 0;
1733   info->factor_mallocs    = 0;
1734   PetscFunctionReturn(0);
1735 }
1736 
1737 #undef __FUNCT__
1738 #define __FUNCT__ "MatSetOption_MPIAIJ"
1739 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscBool flg)
1740 {
1741   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1742   PetscErrorCode ierr;
1743 
1744   PetscFunctionBegin;
1745   switch (op) {
1746   case MAT_NEW_NONZERO_LOCATIONS:
1747   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1748   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1749   case MAT_KEEP_NONZERO_PATTERN:
1750   case MAT_NEW_NONZERO_LOCATION_ERR:
1751   case MAT_USE_INODES:
1752   case MAT_IGNORE_ZERO_ENTRIES:
1753     MatCheckPreallocated(A,1);
1754     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1755     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1756     break;
1757   case MAT_ROW_ORIENTED:
1758     a->roworiented = flg;
1759 
1760     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1761     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1762     break;
1763   case MAT_NEW_DIAGONALS:
1764     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1765     break;
1766   case MAT_IGNORE_OFF_PROC_ENTRIES:
1767     a->donotstash = flg;
1768     break;
1769   case MAT_SPD:
1770     A->spd_set = PETSC_TRUE;
1771     A->spd     = flg;
1772     if (flg) {
1773       A->symmetric                  = PETSC_TRUE;
1774       A->structurally_symmetric     = PETSC_TRUE;
1775       A->symmetric_set              = PETSC_TRUE;
1776       A->structurally_symmetric_set = PETSC_TRUE;
1777     }
1778     break;
1779   case MAT_SYMMETRIC:
1780     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1781     break;
1782   case MAT_STRUCTURALLY_SYMMETRIC:
1783     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1784     break;
1785   case MAT_HERMITIAN:
1786     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1787     break;
1788   case MAT_SYMMETRY_ETERNAL:
1789     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1790     break;
1791   default:
1792     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"unknown option %d",op);
1793   }
1794   PetscFunctionReturn(0);
1795 }
1796 
1797 #undef __FUNCT__
1798 #define __FUNCT__ "MatGetRow_MPIAIJ"
1799 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1800 {
1801   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1802   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1803   PetscErrorCode ierr;
1804   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1805   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1806   PetscInt       *cmap,*idx_p;
1807 
1808   PetscFunctionBegin;
1809   if (mat->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Already active");
1810   mat->getrowactive = PETSC_TRUE;
1811 
1812   if (!mat->rowvalues && (idx || v)) {
1813     /*
1814         allocate enough space to hold information from the longest row.
1815     */
1816     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1817     PetscInt   max = 1,tmp;
1818     for (i=0; i<matin->rmap->n; i++) {
1819       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1820       if (max < tmp) max = tmp;
1821     }
1822     ierr = PetscMalloc2(max,&mat->rowvalues,max,&mat->rowindices);CHKERRQ(ierr);
1823   }
1824 
1825   if (row < rstart || row >= rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only local rows");
1826   lrow = row - rstart;
1827 
1828   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1829   if (!v)   {pvA = 0; pvB = 0;}
1830   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1831   ierr  = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1832   ierr  = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1833   nztot = nzA + nzB;
1834 
1835   cmap = mat->garray;
1836   if (v  || idx) {
1837     if (nztot) {
1838       /* Sort by increasing column numbers, assuming A and B already sorted */
1839       PetscInt imark = -1;
1840       if (v) {
1841         *v = v_p = mat->rowvalues;
1842         for (i=0; i<nzB; i++) {
1843           if (cmap[cworkB[i]] < cstart) v_p[i] = vworkB[i];
1844           else break;
1845         }
1846         imark = i;
1847         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1848         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1849       }
1850       if (idx) {
1851         *idx = idx_p = mat->rowindices;
1852         if (imark > -1) {
1853           for (i=0; i<imark; i++) {
1854             idx_p[i] = cmap[cworkB[i]];
1855           }
1856         } else {
1857           for (i=0; i<nzB; i++) {
1858             if (cmap[cworkB[i]] < cstart) idx_p[i] = cmap[cworkB[i]];
1859             else break;
1860           }
1861           imark = i;
1862         }
1863         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1864         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1865       }
1866     } else {
1867       if (idx) *idx = 0;
1868       if (v)   *v   = 0;
1869     }
1870   }
1871   *nz  = nztot;
1872   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1873   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1874   PetscFunctionReturn(0);
1875 }
1876 
1877 #undef __FUNCT__
1878 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1879 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1880 {
1881   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1882 
1883   PetscFunctionBegin;
1884   if (!aij->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1885   aij->getrowactive = PETSC_FALSE;
1886   PetscFunctionReturn(0);
1887 }
1888 
1889 #undef __FUNCT__
1890 #define __FUNCT__ "MatNorm_MPIAIJ"
1891 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1892 {
1893   Mat_MPIAIJ     *aij  = (Mat_MPIAIJ*)mat->data;
1894   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1895   PetscErrorCode ierr;
1896   PetscInt       i,j,cstart = mat->cmap->rstart;
1897   PetscReal      sum = 0.0;
1898   MatScalar      *v;
1899 
1900   PetscFunctionBegin;
1901   if (aij->size == 1) {
1902     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1903   } else {
1904     if (type == NORM_FROBENIUS) {
1905       v = amat->a;
1906       for (i=0; i<amat->nz; i++) {
1907         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1908       }
1909       v = bmat->a;
1910       for (i=0; i<bmat->nz; i++) {
1911         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1912       }
1913       ierr  = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1914       *norm = PetscSqrtReal(*norm);
1915     } else if (type == NORM_1) { /* max column norm */
1916       PetscReal *tmp,*tmp2;
1917       PetscInt  *jj,*garray = aij->garray;
1918       ierr  = PetscCalloc1(mat->cmap->N+1,&tmp);CHKERRQ(ierr);
1919       ierr  = PetscMalloc1(mat->cmap->N+1,&tmp2);CHKERRQ(ierr);
1920       *norm = 0.0;
1921       v     = amat->a; jj = amat->j;
1922       for (j=0; j<amat->nz; j++) {
1923         tmp[cstart + *jj++] += PetscAbsScalar(*v);  v++;
1924       }
1925       v = bmat->a; jj = bmat->j;
1926       for (j=0; j<bmat->nz; j++) {
1927         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1928       }
1929       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1930       for (j=0; j<mat->cmap->N; j++) {
1931         if (tmp2[j] > *norm) *norm = tmp2[j];
1932       }
1933       ierr = PetscFree(tmp);CHKERRQ(ierr);
1934       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1935     } else if (type == NORM_INFINITY) { /* max row norm */
1936       PetscReal ntemp = 0.0;
1937       for (j=0; j<aij->A->rmap->n; j++) {
1938         v   = amat->a + amat->i[j];
1939         sum = 0.0;
1940         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1941           sum += PetscAbsScalar(*v); v++;
1942         }
1943         v = bmat->a + bmat->i[j];
1944         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1945           sum += PetscAbsScalar(*v); v++;
1946         }
1947         if (sum > ntemp) ntemp = sum;
1948       }
1949       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1950     } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"No support for two norm");
1951   }
1952   PetscFunctionReturn(0);
1953 }
1954 
1955 #undef __FUNCT__
1956 #define __FUNCT__ "MatTranspose_MPIAIJ"
1957 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
1958 {
1959   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1960   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
1961   PetscErrorCode ierr;
1962   PetscInt       M      = A->rmap->N,N = A->cmap->N,ma,na,mb,nb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i;
1963   PetscInt       cstart = A->cmap->rstart,ncol;
1964   Mat            B;
1965   MatScalar      *array;
1966 
1967   PetscFunctionBegin;
1968   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
1969 
1970   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n; nb = a->B->cmap->n;
1971   ai = Aloc->i; aj = Aloc->j;
1972   bi = Bloc->i; bj = Bloc->j;
1973   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1974     PetscInt             *d_nnz,*g_nnz,*o_nnz;
1975     PetscSFNode          *oloc;
1976     PETSC_UNUSED PetscSF sf;
1977 
1978     ierr = PetscMalloc4(na,&d_nnz,na,&o_nnz,nb,&g_nnz,nb,&oloc);CHKERRQ(ierr);
1979     /* compute d_nnz for preallocation */
1980     ierr = PetscMemzero(d_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1981     for (i=0; i<ai[ma]; i++) {
1982       d_nnz[aj[i]]++;
1983       aj[i] += cstart; /* global col index to be used by MatSetValues() */
1984     }
1985     /* compute local off-diagonal contributions */
1986     ierr = PetscMemzero(g_nnz,nb*sizeof(PetscInt));CHKERRQ(ierr);
1987     for (i=0; i<bi[ma]; i++) g_nnz[bj[i]]++;
1988     /* map those to global */
1989     ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1990     ierr = PetscSFSetGraphLayout(sf,A->cmap,nb,NULL,PETSC_USE_POINTER,a->garray);CHKERRQ(ierr);
1991     ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1992     ierr = PetscMemzero(o_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1993     ierr = PetscSFReduceBegin(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1994     ierr = PetscSFReduceEnd(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1995     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1996 
1997     ierr = MatCreate(PetscObjectComm((PetscObject)A),&B);CHKERRQ(ierr);
1998     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
1999     ierr = MatSetBlockSizes(B,PetscAbs(A->cmap->bs),PetscAbs(A->rmap->bs));CHKERRQ(ierr);
2000     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
2001     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
2002     ierr = PetscFree4(d_nnz,o_nnz,g_nnz,oloc);CHKERRQ(ierr);
2003   } else {
2004     B    = *matout;
2005     ierr = MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
2006     for (i=0; i<ai[ma]; i++) aj[i] += cstart; /* global col index to be used by MatSetValues() */
2007   }
2008 
2009   /* copy over the A part */
2010   array = Aloc->a;
2011   row   = A->rmap->rstart;
2012   for (i=0; i<ma; i++) {
2013     ncol = ai[i+1]-ai[i];
2014     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2015     row++;
2016     array += ncol; aj += ncol;
2017   }
2018   aj = Aloc->j;
2019   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
2020 
2021   /* copy over the B part */
2022   ierr  = PetscCalloc1(bi[mb],&cols);CHKERRQ(ierr);
2023   array = Bloc->a;
2024   row   = A->rmap->rstart;
2025   for (i=0; i<bi[mb]; i++) cols[i] = a->garray[bj[i]];
2026   cols_tmp = cols;
2027   for (i=0; i<mb; i++) {
2028     ncol = bi[i+1]-bi[i];
2029     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2030     row++;
2031     array += ncol; cols_tmp += ncol;
2032   }
2033   ierr = PetscFree(cols);CHKERRQ(ierr);
2034 
2035   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2036   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2037   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
2038     *matout = B;
2039   } else {
2040     ierr = MatHeaderMerge(A,B);CHKERRQ(ierr);
2041   }
2042   PetscFunctionReturn(0);
2043 }
2044 
2045 #undef __FUNCT__
2046 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
2047 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
2048 {
2049   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2050   Mat            a    = aij->A,b = aij->B;
2051   PetscErrorCode ierr;
2052   PetscInt       s1,s2,s3;
2053 
2054   PetscFunctionBegin;
2055   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
2056   if (rr) {
2057     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
2058     if (s1!=s3) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
2059     /* Overlap communication with computation. */
2060     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2061   }
2062   if (ll) {
2063     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
2064     if (s1!=s2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
2065     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
2066   }
2067   /* scale  the diagonal block */
2068   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
2069 
2070   if (rr) {
2071     /* Do a scatter end and then right scale the off-diagonal block */
2072     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2073     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
2074   }
2075   PetscFunctionReturn(0);
2076 }
2077 
2078 #undef __FUNCT__
2079 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
2080 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2081 {
2082   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2083   PetscErrorCode ierr;
2084 
2085   PetscFunctionBegin;
2086   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
2087   PetscFunctionReturn(0);
2088 }
2089 
2090 #undef __FUNCT__
2091 #define __FUNCT__ "MatEqual_MPIAIJ"
2092 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscBool  *flag)
2093 {
2094   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
2095   Mat            a,b,c,d;
2096   PetscBool      flg;
2097   PetscErrorCode ierr;
2098 
2099   PetscFunctionBegin;
2100   a = matA->A; b = matA->B;
2101   c = matB->A; d = matB->B;
2102 
2103   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
2104   if (flg) {
2105     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
2106   }
2107   ierr = MPI_Allreduce(&flg,flag,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
2108   PetscFunctionReturn(0);
2109 }
2110 
2111 #undef __FUNCT__
2112 #define __FUNCT__ "MatCopy_MPIAIJ"
2113 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
2114 {
2115   PetscErrorCode ierr;
2116   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2117   Mat_MPIAIJ     *b = (Mat_MPIAIJ*)B->data;
2118 
2119   PetscFunctionBegin;
2120   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2121   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2122     /* because of the column compression in the off-processor part of the matrix a->B,
2123        the number of columns in a->B and b->B may be different, hence we cannot call
2124        the MatCopy() directly on the two parts. If need be, we can provide a more
2125        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2126        then copying the submatrices */
2127     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
2128   } else {
2129     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
2130     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
2131   }
2132   PetscFunctionReturn(0);
2133 }
2134 
2135 #undef __FUNCT__
2136 #define __FUNCT__ "MatSetUp_MPIAIJ"
2137 PetscErrorCode MatSetUp_MPIAIJ(Mat A)
2138 {
2139   PetscErrorCode ierr;
2140 
2141   PetscFunctionBegin;
2142   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
2143   PetscFunctionReturn(0);
2144 }
2145 
2146 /*
2147    Computes the number of nonzeros per row needed for preallocation when X and Y
2148    have different nonzero structure.
2149 */
2150 #undef __FUNCT__
2151 #define __FUNCT__ "MatAXPYGetPreallocation_MPIX_private"
2152 PetscErrorCode MatAXPYGetPreallocation_MPIX_private(PetscInt m,const PetscInt *xi,const PetscInt *xj,const PetscInt *xltog,const PetscInt *yi,const PetscInt *yj,const PetscInt *yltog,PetscInt *nnz)
2153 {
2154   PetscInt       i,j,k,nzx,nzy;
2155 
2156   PetscFunctionBegin;
2157   /* Set the number of nonzeros in the new matrix */
2158   for (i=0; i<m; i++) {
2159     const PetscInt *xjj = xj+xi[i],*yjj = yj+yi[i];
2160     nzx = xi[i+1] - xi[i];
2161     nzy = yi[i+1] - yi[i];
2162     nnz[i] = 0;
2163     for (j=0,k=0; j<nzx; j++) {                   /* Point in X */
2164       for (; k<nzy && yltog[yjj[k]]<xltog[xjj[j]]; k++) nnz[i]++; /* Catch up to X */
2165       if (k<nzy && yltog[yjj[k]]==xltog[xjj[j]]) k++;             /* Skip duplicate */
2166       nnz[i]++;
2167     }
2168     for (; k<nzy; k++) nnz[i]++;
2169   }
2170   PetscFunctionReturn(0);
2171 }
2172 
2173 /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2174 #undef __FUNCT__
2175 #define __FUNCT__ "MatAXPYGetPreallocation_MPIAIJ"
2176 static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y,const PetscInt *yltog,Mat X,const PetscInt *xltog,PetscInt *nnz)
2177 {
2178   PetscErrorCode ierr;
2179   PetscInt       m = Y->rmap->N;
2180   Mat_SeqAIJ     *x = (Mat_SeqAIJ*)X->data;
2181   Mat_SeqAIJ     *y = (Mat_SeqAIJ*)Y->data;
2182 
2183   PetscFunctionBegin;
2184   ierr = MatAXPYGetPreallocation_MPIX_private(m,x->i,x->j,xltog,y->i,y->j,yltog,nnz);CHKERRQ(ierr);
2185   PetscFunctionReturn(0);
2186 }
2187 
2188 #undef __FUNCT__
2189 #define __FUNCT__ "MatAXPY_MPIAIJ"
2190 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
2191 {
2192   PetscErrorCode ierr;
2193   Mat_MPIAIJ     *xx = (Mat_MPIAIJ*)X->data,*yy = (Mat_MPIAIJ*)Y->data;
2194   PetscBLASInt   bnz,one=1;
2195   Mat_SeqAIJ     *x,*y;
2196 
2197   PetscFunctionBegin;
2198   if (str == SAME_NONZERO_PATTERN) {
2199     PetscScalar alpha = a;
2200     x    = (Mat_SeqAIJ*)xx->A->data;
2201     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2202     y    = (Mat_SeqAIJ*)yy->A->data;
2203     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2204     x    = (Mat_SeqAIJ*)xx->B->data;
2205     y    = (Mat_SeqAIJ*)yy->B->data;
2206     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2207     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2208     ierr = PetscObjectStateIncrease((PetscObject)Y);CHKERRQ(ierr);
2209   } else if (str == SUBSET_NONZERO_PATTERN) { /* nonzeros of X is a subset of Y's */
2210     ierr = MatAXPY_Basic(Y,a,X,str);CHKERRQ(ierr);
2211   } else {
2212     Mat      B;
2213     PetscInt *nnz_d,*nnz_o;
2214     ierr = PetscMalloc1(yy->A->rmap->N,&nnz_d);CHKERRQ(ierr);
2215     ierr = PetscMalloc1(yy->B->rmap->N,&nnz_o);CHKERRQ(ierr);
2216     ierr = MatCreate(PetscObjectComm((PetscObject)Y),&B);CHKERRQ(ierr);
2217     ierr = PetscObjectSetName((PetscObject)B,((PetscObject)Y)->name);CHKERRQ(ierr);
2218     ierr = MatSetSizes(B,Y->rmap->n,Y->cmap->n,Y->rmap->N,Y->cmap->N);CHKERRQ(ierr);
2219     ierr = MatSetBlockSizesFromMats(B,Y,Y);CHKERRQ(ierr);
2220     ierr = MatSetType(B,MATMPIAIJ);CHKERRQ(ierr);
2221     ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr);
2222     ierr = MatAXPYGetPreallocation_MPIAIJ(yy->B,yy->garray,xx->B,xx->garray,nnz_o);CHKERRQ(ierr);
2223     ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr);
2224     ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);
2225     ierr = MatHeaderReplace(Y,B);CHKERRQ(ierr);
2226     ierr = PetscFree(nnz_d);CHKERRQ(ierr);
2227     ierr = PetscFree(nnz_o);CHKERRQ(ierr);
2228   }
2229   PetscFunctionReturn(0);
2230 }
2231 
2232 extern PetscErrorCode  MatConjugate_SeqAIJ(Mat);
2233 
2234 #undef __FUNCT__
2235 #define __FUNCT__ "MatConjugate_MPIAIJ"
2236 PetscErrorCode  MatConjugate_MPIAIJ(Mat mat)
2237 {
2238 #if defined(PETSC_USE_COMPLEX)
2239   PetscErrorCode ierr;
2240   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2241 
2242   PetscFunctionBegin;
2243   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
2244   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
2245 #else
2246   PetscFunctionBegin;
2247 #endif
2248   PetscFunctionReturn(0);
2249 }
2250 
2251 #undef __FUNCT__
2252 #define __FUNCT__ "MatRealPart_MPIAIJ"
2253 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2254 {
2255   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2256   PetscErrorCode ierr;
2257 
2258   PetscFunctionBegin;
2259   ierr = MatRealPart(a->A);CHKERRQ(ierr);
2260   ierr = MatRealPart(a->B);CHKERRQ(ierr);
2261   PetscFunctionReturn(0);
2262 }
2263 
2264 #undef __FUNCT__
2265 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
2266 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2267 {
2268   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2269   PetscErrorCode ierr;
2270 
2271   PetscFunctionBegin;
2272   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
2273   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
2274   PetscFunctionReturn(0);
2275 }
2276 
2277 #undef __FUNCT__
2278 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2279 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2280 {
2281   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2282   PetscErrorCode ierr;
2283   PetscInt       i,*idxb = 0;
2284   PetscScalar    *va,*vb;
2285   Vec            vtmp;
2286 
2287   PetscFunctionBegin;
2288   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2289   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2290   if (idx) {
2291     for (i=0; i<A->rmap->n; i++) {
2292       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2293     }
2294   }
2295 
2296   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2297   if (idx) {
2298     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2299   }
2300   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2301   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2302 
2303   for (i=0; i<A->rmap->n; i++) {
2304     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2305       va[i] = vb[i];
2306       if (idx) idx[i] = a->garray[idxb[i]];
2307     }
2308   }
2309 
2310   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2311   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2312   ierr = PetscFree(idxb);CHKERRQ(ierr);
2313   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2314   PetscFunctionReturn(0);
2315 }
2316 
2317 #undef __FUNCT__
2318 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2319 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2320 {
2321   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2322   PetscErrorCode ierr;
2323   PetscInt       i,*idxb = 0;
2324   PetscScalar    *va,*vb;
2325   Vec            vtmp;
2326 
2327   PetscFunctionBegin;
2328   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2329   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2330   if (idx) {
2331     for (i=0; i<A->cmap->n; i++) {
2332       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2333     }
2334   }
2335 
2336   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2337   if (idx) {
2338     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2339   }
2340   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2341   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2342 
2343   for (i=0; i<A->rmap->n; i++) {
2344     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2345       va[i] = vb[i];
2346       if (idx) idx[i] = a->garray[idxb[i]];
2347     }
2348   }
2349 
2350   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2351   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2352   ierr = PetscFree(idxb);CHKERRQ(ierr);
2353   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2354   PetscFunctionReturn(0);
2355 }
2356 
2357 #undef __FUNCT__
2358 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2359 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2360 {
2361   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2362   PetscInt       n      = A->rmap->n;
2363   PetscInt       cstart = A->cmap->rstart;
2364   PetscInt       *cmap  = mat->garray;
2365   PetscInt       *diagIdx, *offdiagIdx;
2366   Vec            diagV, offdiagV;
2367   PetscScalar    *a, *diagA, *offdiagA;
2368   PetscInt       r;
2369   PetscErrorCode ierr;
2370 
2371   PetscFunctionBegin;
2372   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2373   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &diagV);CHKERRQ(ierr);
2374   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &offdiagV);CHKERRQ(ierr);
2375   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2376   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2377   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2378   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2379   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2380   for (r = 0; r < n; ++r) {
2381     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2382       a[r]   = diagA[r];
2383       idx[r] = cstart + diagIdx[r];
2384     } else {
2385       a[r]   = offdiagA[r];
2386       idx[r] = cmap[offdiagIdx[r]];
2387     }
2388   }
2389   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2390   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2391   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2392   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2393   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2394   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2395   PetscFunctionReturn(0);
2396 }
2397 
2398 #undef __FUNCT__
2399 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2400 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2401 {
2402   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2403   PetscInt       n      = A->rmap->n;
2404   PetscInt       cstart = A->cmap->rstart;
2405   PetscInt       *cmap  = mat->garray;
2406   PetscInt       *diagIdx, *offdiagIdx;
2407   Vec            diagV, offdiagV;
2408   PetscScalar    *a, *diagA, *offdiagA;
2409   PetscInt       r;
2410   PetscErrorCode ierr;
2411 
2412   PetscFunctionBegin;
2413   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2414   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &diagV);CHKERRQ(ierr);
2415   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &offdiagV);CHKERRQ(ierr);
2416   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2417   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2418   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2419   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2420   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2421   for (r = 0; r < n; ++r) {
2422     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2423       a[r]   = diagA[r];
2424       idx[r] = cstart + diagIdx[r];
2425     } else {
2426       a[r]   = offdiagA[r];
2427       idx[r] = cmap[offdiagIdx[r]];
2428     }
2429   }
2430   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2431   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2432   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2433   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2434   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2435   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2436   PetscFunctionReturn(0);
2437 }
2438 
2439 #undef __FUNCT__
2440 #define __FUNCT__ "MatGetSeqNonzeroStructure_MPIAIJ"
2441 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
2442 {
2443   PetscErrorCode ierr;
2444   Mat            *dummy;
2445 
2446   PetscFunctionBegin;
2447   ierr    = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
2448   *newmat = *dummy;
2449   ierr    = PetscFree(dummy);CHKERRQ(ierr);
2450   PetscFunctionReturn(0);
2451 }
2452 
2453 #undef __FUNCT__
2454 #define __FUNCT__ "MatInvertBlockDiagonal_MPIAIJ"
2455 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
2456 {
2457   Mat_MPIAIJ     *a = (Mat_MPIAIJ*) A->data;
2458   PetscErrorCode ierr;
2459 
2460   PetscFunctionBegin;
2461   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
2462   PetscFunctionReturn(0);
2463 }
2464 
2465 #undef __FUNCT__
2466 #define __FUNCT__ "MatSetRandom_MPIAIJ"
2467 static PetscErrorCode  MatSetRandom_MPIAIJ(Mat x,PetscRandom rctx)
2468 {
2469   PetscErrorCode ierr;
2470   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)x->data;
2471 
2472   PetscFunctionBegin;
2473   ierr = MatSetRandom(aij->A,rctx);CHKERRQ(ierr);
2474   ierr = MatSetRandom(aij->B,rctx);CHKERRQ(ierr);
2475   ierr = MatAssemblyBegin(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2476   ierr = MatAssemblyEnd(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2477   PetscFunctionReturn(0);
2478 }
2479 
2480 #undef __FUNCT__
2481 #define __FUNCT__ "MatShift_MPIAIJ"
2482 PetscErrorCode MatShift_MPIAIJ(Mat Y,PetscScalar a)
2483 {
2484   PetscErrorCode ierr;
2485   Mat_MPIAIJ     *maij = (Mat_MPIAIJ*)Y->data;
2486   Mat_SeqAIJ     *aij = (Mat_SeqAIJ*)maij->A->data;
2487 
2488   PetscFunctionBegin;
2489   if (!Y->preallocated) {
2490     ierr = MatMPIAIJSetPreallocation(Y,1,NULL,0,NULL);CHKERRQ(ierr);
2491   } else if (!aij->nz) {
2492     ierr = MatSeqAIJSetPreallocation(maij->A,1,NULL);CHKERRQ(ierr);
2493   }
2494   ierr = MatShift_Basic(Y,a);CHKERRQ(ierr);
2495   PetscFunctionReturn(0);
2496 }
2497 
2498 /* -------------------------------------------------------------------*/
2499 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
2500                                        MatGetRow_MPIAIJ,
2501                                        MatRestoreRow_MPIAIJ,
2502                                        MatMult_MPIAIJ,
2503                                 /* 4*/ MatMultAdd_MPIAIJ,
2504                                        MatMultTranspose_MPIAIJ,
2505                                        MatMultTransposeAdd_MPIAIJ,
2506                                        0,
2507                                        0,
2508                                        0,
2509                                 /*10*/ 0,
2510                                        0,
2511                                        0,
2512                                        MatSOR_MPIAIJ,
2513                                        MatTranspose_MPIAIJ,
2514                                 /*15*/ MatGetInfo_MPIAIJ,
2515                                        MatEqual_MPIAIJ,
2516                                        MatGetDiagonal_MPIAIJ,
2517                                        MatDiagonalScale_MPIAIJ,
2518                                        MatNorm_MPIAIJ,
2519                                 /*20*/ MatAssemblyBegin_MPIAIJ,
2520                                        MatAssemblyEnd_MPIAIJ,
2521                                        MatSetOption_MPIAIJ,
2522                                        MatZeroEntries_MPIAIJ,
2523                                 /*24*/ MatZeroRows_MPIAIJ,
2524                                        0,
2525                                        0,
2526                                        0,
2527                                        0,
2528                                 /*29*/ MatSetUp_MPIAIJ,
2529                                        0,
2530                                        0,
2531                                        0,
2532                                        0,
2533                                 /*34*/ MatDuplicate_MPIAIJ,
2534                                        0,
2535                                        0,
2536                                        0,
2537                                        0,
2538                                 /*39*/ MatAXPY_MPIAIJ,
2539                                        MatGetSubMatrices_MPIAIJ,
2540                                        MatIncreaseOverlap_MPIAIJ,
2541                                        MatGetValues_MPIAIJ,
2542                                        MatCopy_MPIAIJ,
2543                                 /*44*/ MatGetRowMax_MPIAIJ,
2544                                        MatScale_MPIAIJ,
2545                                        MatShift_MPIAIJ,
2546                                        MatDiagonalSet_MPIAIJ,
2547                                        MatZeroRowsColumns_MPIAIJ,
2548                                 /*49*/ MatSetRandom_MPIAIJ,
2549                                        0,
2550                                        0,
2551                                        0,
2552                                        0,
2553                                 /*54*/ MatFDColoringCreate_MPIXAIJ,
2554                                        0,
2555                                        MatSetUnfactored_MPIAIJ,
2556                                        MatPermute_MPIAIJ,
2557                                        0,
2558                                 /*59*/ MatGetSubMatrix_MPIAIJ,
2559                                        MatDestroy_MPIAIJ,
2560                                        MatView_MPIAIJ,
2561                                        0,
2562                                        MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ,
2563                                 /*64*/ MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ,
2564                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
2565                                        0,
2566                                        0,
2567                                        0,
2568                                 /*69*/ MatGetRowMaxAbs_MPIAIJ,
2569                                        MatGetRowMinAbs_MPIAIJ,
2570                                        0,
2571                                        MatSetColoring_MPIAIJ,
2572                                        0,
2573                                        MatSetValuesAdifor_MPIAIJ,
2574                                 /*75*/ MatFDColoringApply_AIJ,
2575                                        0,
2576                                        0,
2577                                        0,
2578                                        MatFindZeroDiagonals_MPIAIJ,
2579                                 /*80*/ 0,
2580                                        0,
2581                                        0,
2582                                 /*83*/ MatLoad_MPIAIJ,
2583                                        0,
2584                                        0,
2585                                        0,
2586                                        0,
2587                                        0,
2588                                 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
2589                                        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
2590                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
2591                                        MatPtAP_MPIAIJ_MPIAIJ,
2592                                        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
2593                                 /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
2594                                        0,
2595                                        0,
2596                                        0,
2597                                        0,
2598                                 /*99*/ 0,
2599                                        0,
2600                                        0,
2601                                        MatConjugate_MPIAIJ,
2602                                        0,
2603                                 /*104*/MatSetValuesRow_MPIAIJ,
2604                                        MatRealPart_MPIAIJ,
2605                                        MatImaginaryPart_MPIAIJ,
2606                                        0,
2607                                        0,
2608                                 /*109*/0,
2609                                        0,
2610                                        MatGetRowMin_MPIAIJ,
2611                                        0,
2612                                        0,
2613                                 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
2614                                        0,
2615                                        MatGetGhosts_MPIAIJ,
2616                                        0,
2617                                        0,
2618                                 /*119*/0,
2619                                        0,
2620                                        0,
2621                                        0,
2622                                        MatGetMultiProcBlock_MPIAIJ,
2623                                 /*124*/MatFindNonzeroRows_MPIAIJ,
2624                                        MatGetColumnNorms_MPIAIJ,
2625                                        MatInvertBlockDiagonal_MPIAIJ,
2626                                        0,
2627                                        MatGetSubMatricesMPI_MPIAIJ,
2628                                 /*129*/0,
2629                                        MatTransposeMatMult_MPIAIJ_MPIAIJ,
2630                                        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
2631                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
2632                                        0,
2633                                 /*134*/0,
2634                                        0,
2635                                        0,
2636                                        0,
2637                                        0,
2638                                 /*139*/0,
2639                                        0,
2640                                        0,
2641                                        MatFDColoringSetUp_MPIXAIJ,
2642                                        MatFindOffBlockDiagonalEntries_MPIAIJ,
2643                                 /*144*/MatCreateMPIMatConcatenateSeqMat_MPIAIJ
2644 };
2645 
2646 /* ----------------------------------------------------------------------------------------*/
2647 
2648 #undef __FUNCT__
2649 #define __FUNCT__ "MatStoreValues_MPIAIJ"
2650 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
2651 {
2652   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2653   PetscErrorCode ierr;
2654 
2655   PetscFunctionBegin;
2656   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
2657   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
2658   PetscFunctionReturn(0);
2659 }
2660 
2661 #undef __FUNCT__
2662 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
2663 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
2664 {
2665   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2666   PetscErrorCode ierr;
2667 
2668   PetscFunctionBegin;
2669   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
2670   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
2671   PetscFunctionReturn(0);
2672 }
2673 
2674 #undef __FUNCT__
2675 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
2676 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
2677 {
2678   Mat_MPIAIJ     *b;
2679   PetscErrorCode ierr;
2680 
2681   PetscFunctionBegin;
2682   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
2683   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
2684   b = (Mat_MPIAIJ*)B->data;
2685 
2686   if (!B->preallocated) {
2687     /* Explicitly create 2 MATSEQAIJ matrices. */
2688     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
2689     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
2690     ierr = MatSetBlockSizesFromMats(b->A,B,B);CHKERRQ(ierr);
2691     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
2692     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->A);CHKERRQ(ierr);
2693     ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
2694     ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
2695     ierr = MatSetBlockSizesFromMats(b->B,B,B);CHKERRQ(ierr);
2696     ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
2697     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->B);CHKERRQ(ierr);
2698   }
2699 
2700   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
2701   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
2702   B->preallocated = PETSC_TRUE;
2703   PetscFunctionReturn(0);
2704 }
2705 
2706 #undef __FUNCT__
2707 #define __FUNCT__ "MatDuplicate_MPIAIJ"
2708 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
2709 {
2710   Mat            mat;
2711   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
2712   PetscErrorCode ierr;
2713 
2714   PetscFunctionBegin;
2715   *newmat = 0;
2716   ierr    = MatCreate(PetscObjectComm((PetscObject)matin),&mat);CHKERRQ(ierr);
2717   ierr    = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
2718   ierr    = MatSetBlockSizesFromMats(mat,matin,matin);CHKERRQ(ierr);
2719   ierr    = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
2720   ierr    = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
2721   a       = (Mat_MPIAIJ*)mat->data;
2722 
2723   mat->factortype   = matin->factortype;
2724   mat->assembled    = PETSC_TRUE;
2725   mat->insertmode   = NOT_SET_VALUES;
2726   mat->preallocated = PETSC_TRUE;
2727 
2728   a->size         = oldmat->size;
2729   a->rank         = oldmat->rank;
2730   a->donotstash   = oldmat->donotstash;
2731   a->roworiented  = oldmat->roworiented;
2732   a->rowindices   = 0;
2733   a->rowvalues    = 0;
2734   a->getrowactive = PETSC_FALSE;
2735 
2736   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
2737   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
2738 
2739   if (oldmat->colmap) {
2740 #if defined(PETSC_USE_CTABLE)
2741     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
2742 #else
2743     ierr = PetscMalloc1(mat->cmap->N,&a->colmap);CHKERRQ(ierr);
2744     ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2745     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2746 #endif
2747   } else a->colmap = 0;
2748   if (oldmat->garray) {
2749     PetscInt len;
2750     len  = oldmat->B->cmap->n;
2751     ierr = PetscMalloc1(len+1,&a->garray);CHKERRQ(ierr);
2752     ierr = PetscLogObjectMemory((PetscObject)mat,len*sizeof(PetscInt));CHKERRQ(ierr);
2753     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
2754   } else a->garray = 0;
2755 
2756   ierr    = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
2757   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->lvec);CHKERRQ(ierr);
2758   ierr    = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
2759   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->Mvctx);CHKERRQ(ierr);
2760   ierr    = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
2761   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->A);CHKERRQ(ierr);
2762   ierr    = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
2763   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->B);CHKERRQ(ierr);
2764   ierr    = PetscFunctionListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
2765   *newmat = mat;
2766   PetscFunctionReturn(0);
2767 }
2768 
2769 
2770 
2771 #undef __FUNCT__
2772 #define __FUNCT__ "MatLoad_MPIAIJ"
2773 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
2774 {
2775   PetscScalar    *vals,*svals;
2776   MPI_Comm       comm;
2777   PetscErrorCode ierr;
2778   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
2779   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0;
2780   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
2781   PetscInt       *ourlens = NULL,*procsnz = NULL,*offlens = NULL,jj,*mycols,*smycols;
2782   PetscInt       cend,cstart,n,*rowners;
2783   int            fd;
2784   PetscInt       bs = newMat->rmap->bs;
2785 
2786   PetscFunctionBegin;
2787   /* force binary viewer to load .info file if it has not yet done so */
2788   ierr = PetscViewerSetUp(viewer);CHKERRQ(ierr);
2789   ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
2790   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2791   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2792   ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
2793   if (!rank) {
2794     ierr = PetscBinaryRead(fd,(char*)header,4,PETSC_INT);CHKERRQ(ierr);
2795     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
2796   }
2797 
2798   ierr = PetscOptionsBegin(comm,NULL,"Options for loading MPIAIJ matrix","Mat");CHKERRQ(ierr);
2799   ierr = PetscOptionsInt("-matload_block_size","Set the blocksize used to store the matrix","MatLoad",bs,&bs,NULL);CHKERRQ(ierr);
2800   ierr = PetscOptionsEnd();CHKERRQ(ierr);
2801   if (bs < 0) bs = 1;
2802 
2803   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
2804   M    = header[1]; N = header[2];
2805 
2806   /* If global sizes are set, check if they are consistent with that given in the file */
2807   if (newMat->rmap->N >= 0 && newMat->rmap->N != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"Inconsistent # of rows:Matrix in file has (%D) and input matrix has (%D)",newMat->rmap->N,M);
2808   if (newMat->cmap->N >=0 && newMat->cmap->N != N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"Inconsistent # of cols:Matrix in file has (%D) and input matrix has (%D)",newMat->cmap->N,N);
2809 
2810   /* determine ownership of all (block) rows */
2811   if (M%bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows (%d) and block size (%d)",M,bs);
2812   if (newMat->rmap->n < 0) m = bs*((M/bs)/size + (((M/bs) % size) > rank));    /* PETSC_DECIDE */
2813   else m = newMat->rmap->n; /* Set by user */
2814 
2815   ierr = PetscMalloc1(size+1,&rowners);CHKERRQ(ierr);
2816   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
2817 
2818   /* First process needs enough room for process with most rows */
2819   if (!rank) {
2820     mmax = rowners[1];
2821     for (i=2; i<=size; i++) {
2822       mmax = PetscMax(mmax, rowners[i]);
2823     }
2824   } else mmax = -1;             /* unused, but compilers complain */
2825 
2826   rowners[0] = 0;
2827   for (i=2; i<=size; i++) {
2828     rowners[i] += rowners[i-1];
2829   }
2830   rstart = rowners[rank];
2831   rend   = rowners[rank+1];
2832 
2833   /* distribute row lengths to all processors */
2834   ierr = PetscMalloc2(m,&ourlens,m,&offlens);CHKERRQ(ierr);
2835   if (!rank) {
2836     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
2837     ierr = PetscMalloc1(mmax,&rowlengths);CHKERRQ(ierr);
2838     ierr = PetscCalloc1(size,&procsnz);CHKERRQ(ierr);
2839     for (j=0; j<m; j++) {
2840       procsnz[0] += ourlens[j];
2841     }
2842     for (i=1; i<size; i++) {
2843       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
2844       /* calculate the number of nonzeros on each processor */
2845       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
2846         procsnz[i] += rowlengths[j];
2847       }
2848       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2849     }
2850     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
2851   } else {
2852     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
2853   }
2854 
2855   if (!rank) {
2856     /* determine max buffer needed and allocate it */
2857     maxnz = 0;
2858     for (i=0; i<size; i++) {
2859       maxnz = PetscMax(maxnz,procsnz[i]);
2860     }
2861     ierr = PetscMalloc1(maxnz,&cols);CHKERRQ(ierr);
2862 
2863     /* read in my part of the matrix column indices  */
2864     nz   = procsnz[0];
2865     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
2866     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
2867 
2868     /* read in every one elses and ship off */
2869     for (i=1; i<size; i++) {
2870       nz   = procsnz[i];
2871       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
2872       ierr = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2873     }
2874     ierr = PetscFree(cols);CHKERRQ(ierr);
2875   } else {
2876     /* determine buffer space needed for message */
2877     nz = 0;
2878     for (i=0; i<m; i++) {
2879       nz += ourlens[i];
2880     }
2881     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
2882 
2883     /* receive message of column indices*/
2884     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
2885   }
2886 
2887   /* determine column ownership if matrix is not square */
2888   if (N != M) {
2889     if (newMat->cmap->n < 0) n = N/size + ((N % size) > rank);
2890     else n = newMat->cmap->n;
2891     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
2892     cstart = cend - n;
2893   } else {
2894     cstart = rstart;
2895     cend   = rend;
2896     n      = cend - cstart;
2897   }
2898 
2899   /* loop over local rows, determining number of off diagonal entries */
2900   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
2901   jj   = 0;
2902   for (i=0; i<m; i++) {
2903     for (j=0; j<ourlens[i]; j++) {
2904       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
2905       jj++;
2906     }
2907   }
2908 
2909   for (i=0; i<m; i++) {
2910     ourlens[i] -= offlens[i];
2911   }
2912   ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
2913 
2914   if (bs > 1) {ierr = MatSetBlockSize(newMat,bs);CHKERRQ(ierr);}
2915 
2916   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
2917 
2918   for (i=0; i<m; i++) {
2919     ourlens[i] += offlens[i];
2920   }
2921 
2922   if (!rank) {
2923     ierr = PetscMalloc1(maxnz+1,&vals);CHKERRQ(ierr);
2924 
2925     /* read in my part of the matrix numerical values  */
2926     nz   = procsnz[0];
2927     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2928 
2929     /* insert into matrix */
2930     jj      = rstart;
2931     smycols = mycols;
2932     svals   = vals;
2933     for (i=0; i<m; i++) {
2934       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2935       smycols += ourlens[i];
2936       svals   += ourlens[i];
2937       jj++;
2938     }
2939 
2940     /* read in other processors and ship out */
2941     for (i=1; i<size; i++) {
2942       nz   = procsnz[i];
2943       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2944       ierr = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
2945     }
2946     ierr = PetscFree(procsnz);CHKERRQ(ierr);
2947   } else {
2948     /* receive numeric values */
2949     ierr = PetscMalloc1(nz+1,&vals);CHKERRQ(ierr);
2950 
2951     /* receive message of values*/
2952     ierr = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
2953 
2954     /* insert into matrix */
2955     jj      = rstart;
2956     smycols = mycols;
2957     svals   = vals;
2958     for (i=0; i<m; i++) {
2959       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2960       smycols += ourlens[i];
2961       svals   += ourlens[i];
2962       jj++;
2963     }
2964   }
2965   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
2966   ierr = PetscFree(vals);CHKERRQ(ierr);
2967   ierr = PetscFree(mycols);CHKERRQ(ierr);
2968   ierr = PetscFree(rowners);CHKERRQ(ierr);
2969   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2970   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2971   PetscFunctionReturn(0);
2972 }
2973 
2974 #undef __FUNCT__
2975 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
2976 /* TODO: Not scalable because of ISAllGather() unless getting all columns. */
2977 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
2978 {
2979   PetscErrorCode ierr;
2980   IS             iscol_local;
2981   PetscInt       csize;
2982 
2983   PetscFunctionBegin;
2984   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
2985   if (call == MAT_REUSE_MATRIX) {
2986     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
2987     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
2988   } else {
2989     /* check if we are grabbing all columns*/
2990     PetscBool    isstride;
2991     PetscMPIInt  lisstride = 0,gisstride;
2992     ierr = PetscObjectTypeCompare((PetscObject)iscol,ISSTRIDE,&isstride);CHKERRQ(ierr);
2993     if (isstride) {
2994       PetscInt  start,len,mstart,mlen;
2995       ierr = ISStrideGetInfo(iscol,&start,NULL);CHKERRQ(ierr);
2996       ierr = ISGetLocalSize(iscol,&len);CHKERRQ(ierr);
2997       ierr = MatGetOwnershipRangeColumn(mat,&mstart,&mlen);CHKERRQ(ierr);
2998       if (mstart == start && mlen-mstart == len) lisstride = 1;
2999     }
3000     ierr = MPI_Allreduce(&lisstride,&gisstride,1,MPI_INT,MPI_MIN,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
3001     if (gisstride) {
3002       PetscInt N;
3003       ierr = MatGetSize(mat,NULL,&N);CHKERRQ(ierr);
3004       ierr = ISCreateStride(PetscObjectComm((PetscObject)mat),N,0,1,&iscol_local);CHKERRQ(ierr);
3005       ierr = ISSetIdentity(iscol_local);CHKERRQ(ierr);
3006       ierr = PetscInfo(mat,"Optimizing for obtaining all columns of the matrix; skipping ISAllGather()\n");CHKERRQ(ierr);
3007     } else {
3008       PetscInt cbs;
3009       ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3010       ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
3011       ierr = ISSetBlockSize(iscol_local,cbs);CHKERRQ(ierr);
3012     }
3013   }
3014   ierr = MatGetSubMatrix_MPIAIJ_Private(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3015   if (call == MAT_INITIAL_MATRIX) {
3016     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3017     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3018   }
3019   PetscFunctionReturn(0);
3020 }
3021 
3022 extern PetscErrorCode MatGetSubMatrices_MPIAIJ_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool*,Mat*);
3023 #undef __FUNCT__
3024 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ_Private"
3025 /*
3026     Not great since it makes two copies of the submatrix, first an SeqAIJ
3027   in local and then by concatenating the local matrices the end result.
3028   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3029 
3030   Note: This requires a sequential iscol with all indices.
3031 */
3032 PetscErrorCode MatGetSubMatrix_MPIAIJ_Private(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3033 {
3034   PetscErrorCode ierr;
3035   PetscMPIInt    rank,size;
3036   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3037   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal,ncol;
3038   PetscBool      allcolumns, colflag;
3039   Mat            M,Mreuse;
3040   MatScalar      *vwork,*aa;
3041   MPI_Comm       comm;
3042   Mat_SeqAIJ     *aij;
3043 
3044   PetscFunctionBegin;
3045   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3046   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3047   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3048 
3049   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3050   ierr = ISGetLocalSize(iscol,&ncol);CHKERRQ(ierr);
3051   if (colflag && ncol == mat->cmap->N) {
3052     allcolumns = PETSC_TRUE;
3053     ierr = PetscInfo(mat,"Optimizing for obtaining all columns of the matrix\n");CHKERRQ(ierr);
3054   } else {
3055     allcolumns = PETSC_FALSE;
3056   }
3057   if (call ==  MAT_REUSE_MATRIX) {
3058     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Mreuse);CHKERRQ(ierr);
3059     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3060     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3061   } else {
3062     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3063   }
3064 
3065   /*
3066       m - number of local rows
3067       n - number of columns (same on all processors)
3068       rstart - first row in new global matrix generated
3069   */
3070   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3071   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3072   if (call == MAT_INITIAL_MATRIX) {
3073     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3074     ii  = aij->i;
3075     jj  = aij->j;
3076 
3077     /*
3078         Determine the number of non-zeros in the diagonal and off-diagonal
3079         portions of the matrix in order to do correct preallocation
3080     */
3081 
3082     /* first get start and end of "diagonal" columns */
3083     if (csize == PETSC_DECIDE) {
3084       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3085       if (mglobal == n) { /* square matrix */
3086         nlocal = m;
3087       } else {
3088         nlocal = n/size + ((n % size) > rank);
3089       }
3090     } else {
3091       nlocal = csize;
3092     }
3093     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3094     rstart = rend - nlocal;
3095     if (rank == size - 1 && rend != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Local column sizes %D do not add up to total number of columns %D",rend,n);
3096 
3097     /* next, compute all the lengths */
3098     ierr  = PetscMalloc1(2*m+1,&dlens);CHKERRQ(ierr);
3099     olens = dlens + m;
3100     for (i=0; i<m; i++) {
3101       jend = ii[i+1] - ii[i];
3102       olen = 0;
3103       dlen = 0;
3104       for (j=0; j<jend; j++) {
3105         if (*jj < rstart || *jj >= rend) olen++;
3106         else dlen++;
3107         jj++;
3108       }
3109       olens[i] = olen;
3110       dlens[i] = dlen;
3111     }
3112     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3113     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3114     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3115     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3116     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3117     ierr = PetscFree(dlens);CHKERRQ(ierr);
3118   } else {
3119     PetscInt ml,nl;
3120 
3121     M    = *newmat;
3122     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3123     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3124     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3125     /*
3126          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3127        rather than the slower MatSetValues().
3128     */
3129     M->was_assembled = PETSC_TRUE;
3130     M->assembled     = PETSC_FALSE;
3131   }
3132   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3133   aij  = (Mat_SeqAIJ*)(Mreuse)->data;
3134   ii   = aij->i;
3135   jj   = aij->j;
3136   aa   = aij->a;
3137   for (i=0; i<m; i++) {
3138     row   = rstart + i;
3139     nz    = ii[i+1] - ii[i];
3140     cwork = jj;     jj += nz;
3141     vwork = aa;     aa += nz;
3142     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3143   }
3144 
3145   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3146   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3147   *newmat = M;
3148 
3149   /* save submatrix used in processor for next request */
3150   if (call ==  MAT_INITIAL_MATRIX) {
3151     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3152     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3153   }
3154   PetscFunctionReturn(0);
3155 }
3156 
3157 #undef __FUNCT__
3158 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3159 PetscErrorCode  MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3160 {
3161   PetscInt       m,cstart, cend,j,nnz,i,d;
3162   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3163   const PetscInt *JJ;
3164   PetscScalar    *values;
3165   PetscErrorCode ierr;
3166 
3167   PetscFunctionBegin;
3168   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3169 
3170   ierr   = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3171   ierr   = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3172   m      = B->rmap->n;
3173   cstart = B->cmap->rstart;
3174   cend   = B->cmap->rend;
3175   rstart = B->rmap->rstart;
3176 
3177   ierr = PetscMalloc2(m,&d_nnz,m,&o_nnz);CHKERRQ(ierr);
3178 
3179 #if defined(PETSC_USE_DEBUGGING)
3180   for (i=0; i<m; i++) {
3181     nnz = Ii[i+1]- Ii[i];
3182     JJ  = J + Ii[i];
3183     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3184     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3185     if (nnz && (JJ[nnz-1] >= B->cmap->N) SETERRRQ3(PETSC_ERR_ARG_WRONGSTATE,"Row %D ends with too large a column index %D (max allowed %D)",i,JJ[nnz-1],B->cmap->N);
3186   }
3187 #endif
3188 
3189   for (i=0; i<m; i++) {
3190     nnz     = Ii[i+1]- Ii[i];
3191     JJ      = J + Ii[i];
3192     nnz_max = PetscMax(nnz_max,nnz);
3193     d       = 0;
3194     for (j=0; j<nnz; j++) {
3195       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3196     }
3197     d_nnz[i] = d;
3198     o_nnz[i] = nnz - d;
3199   }
3200   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3201   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3202 
3203   if (v) values = (PetscScalar*)v;
3204   else {
3205     ierr = PetscCalloc1(nnz_max+1,&values);CHKERRQ(ierr);
3206   }
3207 
3208   for (i=0; i<m; i++) {
3209     ii   = i + rstart;
3210     nnz  = Ii[i+1]- Ii[i];
3211     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3212   }
3213   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3214   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3215 
3216   if (!v) {
3217     ierr = PetscFree(values);CHKERRQ(ierr);
3218   }
3219   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3220   PetscFunctionReturn(0);
3221 }
3222 
3223 #undef __FUNCT__
3224 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3225 /*@
3226    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3227    (the default parallel PETSc format).
3228 
3229    Collective on MPI_Comm
3230 
3231    Input Parameters:
3232 +  B - the matrix
3233 .  i - the indices into j for the start of each local row (starts with zero)
3234 .  j - the column indices for each local row (starts with zero)
3235 -  v - optional values in the matrix
3236 
3237    Level: developer
3238 
3239    Notes:
3240        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3241      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3242      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3243 
3244        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3245 
3246        The format which is used for the sparse matrix input, is equivalent to a
3247     row-major ordering.. i.e for the following matrix, the input data expected is
3248     as shown
3249 
3250 $        1 0 0
3251 $        2 0 3     P0
3252 $       -------
3253 $        4 5 6     P1
3254 $
3255 $     Process0 [P0]: rows_owned=[0,1]
3256 $        i =  {0,1,3}  [size = nrow+1  = 2+1]
3257 $        j =  {0,0,2}  [size = 3]
3258 $        v =  {1,2,3}  [size = 3]
3259 $
3260 $     Process1 [P1]: rows_owned=[2]
3261 $        i =  {0,3}    [size = nrow+1  = 1+1]
3262 $        j =  {0,1,2}  [size = 3]
3263 $        v =  {4,5,6}  [size = 3]
3264 
3265 .keywords: matrix, aij, compressed row, sparse, parallel
3266 
3267 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MPIAIJ,
3268           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3269 @*/
3270 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3271 {
3272   PetscErrorCode ierr;
3273 
3274   PetscFunctionBegin;
3275   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
3276   PetscFunctionReturn(0);
3277 }
3278 
3279 #undef __FUNCT__
3280 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3281 /*@C
3282    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3283    (the default parallel PETSc format).  For good matrix assembly performance
3284    the user should preallocate the matrix storage by setting the parameters
3285    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3286    performance can be increased by more than a factor of 50.
3287 
3288    Collective on MPI_Comm
3289 
3290    Input Parameters:
3291 +  B - the matrix
3292 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3293            (same value is used for all local rows)
3294 .  d_nnz - array containing the number of nonzeros in the various rows of the
3295            DIAGONAL portion of the local submatrix (possibly different for each row)
3296            or NULL (PETSC_NULL_INTEGER in Fortran), if d_nz is used to specify the nonzero structure.
3297            The size of this array is equal to the number of local rows, i.e 'm'.
3298            For matrices that will be factored, you must leave room for (and set)
3299            the diagonal entry even if it is zero.
3300 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3301            submatrix (same value is used for all local rows).
3302 -  o_nnz - array containing the number of nonzeros in the various rows of the
3303            OFF-DIAGONAL portion of the local submatrix (possibly different for
3304            each row) or NULL (PETSC_NULL_INTEGER in Fortran), if o_nz is used to specify the nonzero
3305            structure. The size of this array is equal to the number
3306            of local rows, i.e 'm'.
3307 
3308    If the *_nnz parameter is given then the *_nz parameter is ignored
3309 
3310    The AIJ format (also called the Yale sparse matrix format or
3311    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3312    storage.  The stored row and column indices begin with zero.
3313    See Users-Manual: ch_mat for details.
3314 
3315    The parallel matrix is partitioned such that the first m0 rows belong to
3316    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3317    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3318 
3319    The DIAGONAL portion of the local submatrix of a processor can be defined
3320    as the submatrix which is obtained by extraction the part corresponding to
3321    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
3322    first row that belongs to the processor, r2 is the last row belonging to
3323    the this processor, and c1-c2 is range of indices of the local part of a
3324    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
3325    common case of a square matrix, the row and column ranges are the same and
3326    the DIAGONAL part is also square. The remaining portion of the local
3327    submatrix (mxN) constitute the OFF-DIAGONAL portion.
3328 
3329    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3330 
3331    You can call MatGetInfo() to get information on how effective the preallocation was;
3332    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3333    You can also run with the option -info and look for messages with the string
3334    malloc in them to see if additional memory allocation was needed.
3335 
3336    Example usage:
3337 
3338    Consider the following 8x8 matrix with 34 non-zero values, that is
3339    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3340    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3341    as follows:
3342 
3343 .vb
3344             1  2  0  |  0  3  0  |  0  4
3345     Proc0   0  5  6  |  7  0  0  |  8  0
3346             9  0 10  | 11  0  0  | 12  0
3347     -------------------------------------
3348            13  0 14  | 15 16 17  |  0  0
3349     Proc1   0 18  0  | 19 20 21  |  0  0
3350             0  0  0  | 22 23  0  | 24  0
3351     -------------------------------------
3352     Proc2  25 26 27  |  0  0 28  | 29  0
3353            30  0  0  | 31 32 33  |  0 34
3354 .ve
3355 
3356    This can be represented as a collection of submatrices as:
3357 
3358 .vb
3359       A B C
3360       D E F
3361       G H I
3362 .ve
3363 
3364    Where the submatrices A,B,C are owned by proc0, D,E,F are
3365    owned by proc1, G,H,I are owned by proc2.
3366 
3367    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3368    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3369    The 'M','N' parameters are 8,8, and have the same values on all procs.
3370 
3371    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3372    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3373    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3374    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3375    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3376    matrix, ans [DF] as another SeqAIJ matrix.
3377 
3378    When d_nz, o_nz parameters are specified, d_nz storage elements are
3379    allocated for every row of the local diagonal submatrix, and o_nz
3380    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3381    One way to choose d_nz and o_nz is to use the max nonzerors per local
3382    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3383    In this case, the values of d_nz,o_nz are:
3384 .vb
3385      proc0 : dnz = 2, o_nz = 2
3386      proc1 : dnz = 3, o_nz = 2
3387      proc2 : dnz = 1, o_nz = 4
3388 .ve
3389    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3390    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3391    for proc3. i.e we are using 12+15+10=37 storage locations to store
3392    34 values.
3393 
3394    When d_nnz, o_nnz parameters are specified, the storage is specified
3395    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3396    In the above case the values for d_nnz,o_nnz are:
3397 .vb
3398      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3399      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3400      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3401 .ve
3402    Here the space allocated is sum of all the above values i.e 34, and
3403    hence pre-allocation is perfect.
3404 
3405    Level: intermediate
3406 
3407 .keywords: matrix, aij, compressed row, sparse, parallel
3408 
3409 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
3410           MPIAIJ, MatGetInfo(), PetscSplitOwnership()
3411 @*/
3412 PetscErrorCode  MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3413 {
3414   PetscErrorCode ierr;
3415 
3416   PetscFunctionBegin;
3417   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
3418   PetscValidType(B,1);
3419   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
3420   PetscFunctionReturn(0);
3421 }
3422 
3423 #undef __FUNCT__
3424 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3425 /*@
3426      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3427          CSR format the local rows.
3428 
3429    Collective on MPI_Comm
3430 
3431    Input Parameters:
3432 +  comm - MPI communicator
3433 .  m - number of local rows (Cannot be PETSC_DECIDE)
3434 .  n - This value should be the same as the local size used in creating the
3435        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3436        calculated if N is given) For square matrices n is almost always m.
3437 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3438 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3439 .   i - row indices
3440 .   j - column indices
3441 -   a - matrix values
3442 
3443    Output Parameter:
3444 .   mat - the matrix
3445 
3446    Level: intermediate
3447 
3448    Notes:
3449        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3450      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3451      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3452 
3453        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3454 
3455        The format which is used for the sparse matrix input, is equivalent to a
3456     row-major ordering.. i.e for the following matrix, the input data expected is
3457     as shown
3458 
3459 $        1 0 0
3460 $        2 0 3     P0
3461 $       -------
3462 $        4 5 6     P1
3463 $
3464 $     Process0 [P0]: rows_owned=[0,1]
3465 $        i =  {0,1,3}  [size = nrow+1  = 2+1]
3466 $        j =  {0,0,2}  [size = 3]
3467 $        v =  {1,2,3}  [size = 3]
3468 $
3469 $     Process1 [P1]: rows_owned=[2]
3470 $        i =  {0,3}    [size = nrow+1  = 1+1]
3471 $        j =  {0,1,2}  [size = 3]
3472 $        v =  {4,5,6}  [size = 3]
3473 
3474 .keywords: matrix, aij, compressed row, sparse, parallel
3475 
3476 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3477           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
3478 @*/
3479 PetscErrorCode  MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
3480 {
3481   PetscErrorCode ierr;
3482 
3483   PetscFunctionBegin;
3484   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
3485   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
3486   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
3487   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
3488   /* ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr); */
3489   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
3490   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
3491   PetscFunctionReturn(0);
3492 }
3493 
3494 #undef __FUNCT__
3495 #define __FUNCT__ "MatCreateAIJ"
3496 /*@C
3497    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
3498    (the default parallel PETSc format).  For good matrix assembly performance
3499    the user should preallocate the matrix storage by setting the parameters
3500    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3501    performance can be increased by more than a factor of 50.
3502 
3503    Collective on MPI_Comm
3504 
3505    Input Parameters:
3506 +  comm - MPI communicator
3507 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
3508            This value should be the same as the local size used in creating the
3509            y vector for the matrix-vector product y = Ax.
3510 .  n - This value should be the same as the local size used in creating the
3511        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3512        calculated if N is given) For square matrices n is almost always m.
3513 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3514 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3515 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3516            (same value is used for all local rows)
3517 .  d_nnz - array containing the number of nonzeros in the various rows of the
3518            DIAGONAL portion of the local submatrix (possibly different for each row)
3519            or NULL, if d_nz is used to specify the nonzero structure.
3520            The size of this array is equal to the number of local rows, i.e 'm'.
3521 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3522            submatrix (same value is used for all local rows).
3523 -  o_nnz - array containing the number of nonzeros in the various rows of the
3524            OFF-DIAGONAL portion of the local submatrix (possibly different for
3525            each row) or NULL, if o_nz is used to specify the nonzero
3526            structure. The size of this array is equal to the number
3527            of local rows, i.e 'm'.
3528 
3529    Output Parameter:
3530 .  A - the matrix
3531 
3532    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
3533    MatXXXXSetPreallocation() paradgm instead of this routine directly.
3534    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
3535 
3536    Notes:
3537    If the *_nnz parameter is given then the *_nz parameter is ignored
3538 
3539    m,n,M,N parameters specify the size of the matrix, and its partitioning across
3540    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
3541    storage requirements for this matrix.
3542 
3543    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
3544    processor than it must be used on all processors that share the object for
3545    that argument.
3546 
3547    The user MUST specify either the local or global matrix dimensions
3548    (possibly both).
3549 
3550    The parallel matrix is partitioned across processors such that the
3551    first m0 rows belong to process 0, the next m1 rows belong to
3552    process 1, the next m2 rows belong to process 2 etc.. where
3553    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
3554    values corresponding to [m x N] submatrix.
3555 
3556    The columns are logically partitioned with the n0 columns belonging
3557    to 0th partition, the next n1 columns belonging to the next
3558    partition etc.. where n0,n1,n2... are the input parameter 'n'.
3559 
3560    The DIAGONAL portion of the local submatrix on any given processor
3561    is the submatrix corresponding to the rows and columns m,n
3562    corresponding to the given processor. i.e diagonal matrix on
3563    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
3564    etc. The remaining portion of the local submatrix [m x (N-n)]
3565    constitute the OFF-DIAGONAL portion. The example below better
3566    illustrates this concept.
3567 
3568    For a square global matrix we define each processor's diagonal portion
3569    to be its local rows and the corresponding columns (a square submatrix);
3570    each processor's off-diagonal portion encompasses the remainder of the
3571    local matrix (a rectangular submatrix).
3572 
3573    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3574 
3575    When calling this routine with a single process communicator, a matrix of
3576    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
3577    type of communicator, use the construction mechanism:
3578      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
3579 
3580    By default, this format uses inodes (identical nodes) when possible.
3581    We search for consecutive rows with the same nonzero structure, thereby
3582    reusing matrix information to achieve increased efficiency.
3583 
3584    Options Database Keys:
3585 +  -mat_no_inode  - Do not use inodes
3586 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3587 -  -mat_aij_oneindex - Internally use indexing starting at 1
3588         rather than 0.  Note that when calling MatSetValues(),
3589         the user still MUST index entries starting at 0!
3590 
3591 
3592    Example usage:
3593 
3594    Consider the following 8x8 matrix with 34 non-zero values, that is
3595    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3596    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3597    as follows:
3598 
3599 .vb
3600             1  2  0  |  0  3  0  |  0  4
3601     Proc0   0  5  6  |  7  0  0  |  8  0
3602             9  0 10  | 11  0  0  | 12  0
3603     -------------------------------------
3604            13  0 14  | 15 16 17  |  0  0
3605     Proc1   0 18  0  | 19 20 21  |  0  0
3606             0  0  0  | 22 23  0  | 24  0
3607     -------------------------------------
3608     Proc2  25 26 27  |  0  0 28  | 29  0
3609            30  0  0  | 31 32 33  |  0 34
3610 .ve
3611 
3612    This can be represented as a collection of submatrices as:
3613 
3614 .vb
3615       A B C
3616       D E F
3617       G H I
3618 .ve
3619 
3620    Where the submatrices A,B,C are owned by proc0, D,E,F are
3621    owned by proc1, G,H,I are owned by proc2.
3622 
3623    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3624    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3625    The 'M','N' parameters are 8,8, and have the same values on all procs.
3626 
3627    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3628    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3629    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3630    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3631    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3632    matrix, ans [DF] as another SeqAIJ matrix.
3633 
3634    When d_nz, o_nz parameters are specified, d_nz storage elements are
3635    allocated for every row of the local diagonal submatrix, and o_nz
3636    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3637    One way to choose d_nz and o_nz is to use the max nonzerors per local
3638    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3639    In this case, the values of d_nz,o_nz are:
3640 .vb
3641      proc0 : dnz = 2, o_nz = 2
3642      proc1 : dnz = 3, o_nz = 2
3643      proc2 : dnz = 1, o_nz = 4
3644 .ve
3645    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3646    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3647    for proc3. i.e we are using 12+15+10=37 storage locations to store
3648    34 values.
3649 
3650    When d_nnz, o_nnz parameters are specified, the storage is specified
3651    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3652    In the above case the values for d_nnz,o_nnz are:
3653 .vb
3654      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3655      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3656      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3657 .ve
3658    Here the space allocated is sum of all the above values i.e 34, and
3659    hence pre-allocation is perfect.
3660 
3661    Level: intermediate
3662 
3663 .keywords: matrix, aij, compressed row, sparse, parallel
3664 
3665 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3666           MPIAIJ, MatCreateMPIAIJWithArrays()
3667 @*/
3668 PetscErrorCode  MatCreateAIJ(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[],Mat *A)
3669 {
3670   PetscErrorCode ierr;
3671   PetscMPIInt    size;
3672 
3673   PetscFunctionBegin;
3674   ierr = MatCreate(comm,A);CHKERRQ(ierr);
3675   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
3676   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3677   if (size > 1) {
3678     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
3679     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
3680   } else {
3681     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
3682     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
3683   }
3684   PetscFunctionReturn(0);
3685 }
3686 
3687 #undef __FUNCT__
3688 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
3689 PetscErrorCode  MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,const PetscInt *colmap[])
3690 {
3691   Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
3692 
3693   PetscFunctionBegin;
3694   if (Ad)     *Ad     = a->A;
3695   if (Ao)     *Ao     = a->B;
3696   if (colmap) *colmap = a->garray;
3697   PetscFunctionReturn(0);
3698 }
3699 
3700 #undef __FUNCT__
3701 #define __FUNCT__ "MatSetColoring_MPIAIJ"
3702 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
3703 {
3704   PetscErrorCode ierr;
3705   PetscInt       i;
3706   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3707 
3708   PetscFunctionBegin;
3709   if (coloring->ctype == IS_COLORING_GLOBAL) {
3710     ISColoringValue *allcolors,*colors;
3711     ISColoring      ocoloring;
3712 
3713     /* set coloring for diagonal portion */
3714     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
3715 
3716     /* set coloring for off-diagonal portion */
3717     ierr = ISAllGatherColors(PetscObjectComm((PetscObject)A),coloring->n,coloring->colors,NULL,&allcolors);CHKERRQ(ierr);
3718     ierr = PetscMalloc1(a->B->cmap->n+1,&colors);CHKERRQ(ierr);
3719     for (i=0; i<a->B->cmap->n; i++) {
3720       colors[i] = allcolors[a->garray[i]];
3721     }
3722     ierr = PetscFree(allcolors);CHKERRQ(ierr);
3723     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,PETSC_OWN_POINTER,&ocoloring);CHKERRQ(ierr);
3724     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
3725     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
3726   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
3727     ISColoringValue *colors;
3728     PetscInt        *larray;
3729     ISColoring      ocoloring;
3730 
3731     /* set coloring for diagonal portion */
3732     ierr = PetscMalloc1(a->A->cmap->n+1,&larray);CHKERRQ(ierr);
3733     for (i=0; i<a->A->cmap->n; i++) {
3734       larray[i] = i + A->cmap->rstart;
3735     }
3736     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,NULL,larray);CHKERRQ(ierr);
3737     ierr = PetscMalloc1(a->A->cmap->n+1,&colors);CHKERRQ(ierr);
3738     for (i=0; i<a->A->cmap->n; i++) {
3739       colors[i] = coloring->colors[larray[i]];
3740     }
3741     ierr = PetscFree(larray);CHKERRQ(ierr);
3742     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,PETSC_OWN_POINTER,&ocoloring);CHKERRQ(ierr);
3743     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
3744     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
3745 
3746     /* set coloring for off-diagonal portion */
3747     ierr = PetscMalloc1(a->B->cmap->n+1,&larray);CHKERRQ(ierr);
3748     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,NULL,larray);CHKERRQ(ierr);
3749     ierr = PetscMalloc1(a->B->cmap->n+1,&colors);CHKERRQ(ierr);
3750     for (i=0; i<a->B->cmap->n; i++) {
3751       colors[i] = coloring->colors[larray[i]];
3752     }
3753     ierr = PetscFree(larray);CHKERRQ(ierr);
3754     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,PETSC_OWN_POINTER,&ocoloring);CHKERRQ(ierr);
3755     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
3756     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
3757   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
3758   PetscFunctionReturn(0);
3759 }
3760 
3761 #undef __FUNCT__
3762 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
3763 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
3764 {
3765   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3766   PetscErrorCode ierr;
3767 
3768   PetscFunctionBegin;
3769   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
3770   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
3771   PetscFunctionReturn(0);
3772 }
3773 
3774 #undef __FUNCT__
3775 #define __FUNCT__ "MatCreateMPIMatConcatenateSeqMat_MPIAIJ"
3776 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_MPIAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
3777 {
3778   PetscErrorCode ierr;
3779   PetscInt       m,N,i,rstart,nnz,Ii;
3780   PetscInt       *indx;
3781   PetscScalar    *values;
3782 
3783   PetscFunctionBegin;
3784   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
3785   if (scall == MAT_INITIAL_MATRIX) { /* symbolic phase */
3786     PetscInt       *dnz,*onz,sum,bs,cbs;
3787 
3788     if (n == PETSC_DECIDE) {
3789       ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
3790     }
3791     /* Check sum(n) = N */
3792     ierr = MPI_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3793     if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
3794 
3795     ierr    = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3796     rstart -= m;
3797 
3798     ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
3799     for (i=0; i<m; i++) {
3800       ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
3801       ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
3802       ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
3803     }
3804 
3805     ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
3806     ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
3807     ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
3808     ierr = MatSetBlockSizes(*outmat,bs,cbs);CHKERRQ(ierr);
3809     ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
3810     ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
3811     ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
3812   }
3813 
3814   /* numeric phase */
3815   ierr = MatGetOwnershipRange(*outmat,&rstart,NULL);CHKERRQ(ierr);
3816   for (i=0; i<m; i++) {
3817     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
3818     Ii   = i + rstart;
3819     ierr = MatSetValues(*outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
3820     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
3821   }
3822   ierr = MatAssemblyBegin(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3823   ierr = MatAssemblyEnd(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3824   PetscFunctionReturn(0);
3825 }
3826 
3827 #undef __FUNCT__
3828 #define __FUNCT__ "MatFileSplit"
3829 PetscErrorCode MatFileSplit(Mat A,char *outfile)
3830 {
3831   PetscErrorCode    ierr;
3832   PetscMPIInt       rank;
3833   PetscInt          m,N,i,rstart,nnz;
3834   size_t            len;
3835   const PetscInt    *indx;
3836   PetscViewer       out;
3837   char              *name;
3838   Mat               B;
3839   const PetscScalar *values;
3840 
3841   PetscFunctionBegin;
3842   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
3843   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
3844   /* Should this be the type of the diagonal block of A? */
3845   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
3846   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
3847   ierr = MatSetBlockSizesFromMats(B,A,A);CHKERRQ(ierr);
3848   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
3849   ierr = MatSeqAIJSetPreallocation(B,0,NULL);CHKERRQ(ierr);
3850   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
3851   for (i=0; i<m; i++) {
3852     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
3853     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
3854     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
3855   }
3856   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3857   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3858 
3859   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
3860   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
3861   ierr = PetscMalloc1(len+5,&name);CHKERRQ(ierr);
3862   sprintf(name,"%s.%d",outfile,rank);
3863   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
3864   ierr = PetscFree(name);CHKERRQ(ierr);
3865   ierr = MatView(B,out);CHKERRQ(ierr);
3866   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
3867   ierr = MatDestroy(&B);CHKERRQ(ierr);
3868   PetscFunctionReturn(0);
3869 }
3870 
3871 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
3872 #undef __FUNCT__
3873 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
3874 PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
3875 {
3876   PetscErrorCode      ierr;
3877   Mat_Merge_SeqsToMPI *merge;
3878   PetscContainer      container;
3879 
3880   PetscFunctionBegin;
3881   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
3882   if (container) {
3883     ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
3884     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
3885     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
3886     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
3887     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
3888     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
3889     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
3890     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
3891     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
3892     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
3893     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
3894     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
3895     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
3896     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
3897     ierr = PetscFree(merge);CHKERRQ(ierr);
3898     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
3899   }
3900   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
3901   PetscFunctionReturn(0);
3902 }
3903 
3904 #include <../src/mat/utils/freespace.h>
3905 #include <petscbt.h>
3906 
3907 #undef __FUNCT__
3908 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJNumeric"
3909 PetscErrorCode  MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
3910 {
3911   PetscErrorCode      ierr;
3912   MPI_Comm            comm;
3913   Mat_SeqAIJ          *a  =(Mat_SeqAIJ*)seqmat->data;
3914   PetscMPIInt         size,rank,taga,*len_s;
3915   PetscInt            N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj;
3916   PetscInt            proc,m;
3917   PetscInt            **buf_ri,**buf_rj;
3918   PetscInt            k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
3919   PetscInt            nrows,**buf_ri_k,**nextrow,**nextai;
3920   MPI_Request         *s_waits,*r_waits;
3921   MPI_Status          *status;
3922   MatScalar           *aa=a->a;
3923   MatScalar           **abuf_r,*ba_i;
3924   Mat_Merge_SeqsToMPI *merge;
3925   PetscContainer      container;
3926 
3927   PetscFunctionBegin;
3928   ierr = PetscObjectGetComm((PetscObject)mpimat,&comm);CHKERRQ(ierr);
3929   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
3930 
3931   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3932   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3933 
3934   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
3935   ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
3936 
3937   bi     = merge->bi;
3938   bj     = merge->bj;
3939   buf_ri = merge->buf_ri;
3940   buf_rj = merge->buf_rj;
3941 
3942   ierr   = PetscMalloc1(size,&status);CHKERRQ(ierr);
3943   owners = merge->rowmap->range;
3944   len_s  = merge->len_s;
3945 
3946   /* send and recv matrix values */
3947   /*-----------------------------*/
3948   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
3949   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
3950 
3951   ierr = PetscMalloc1(merge->nsend+1,&s_waits);CHKERRQ(ierr);
3952   for (proc=0,k=0; proc<size; proc++) {
3953     if (!len_s[proc]) continue;
3954     i    = owners[proc];
3955     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
3956     k++;
3957   }
3958 
3959   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
3960   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
3961   ierr = PetscFree(status);CHKERRQ(ierr);
3962 
3963   ierr = PetscFree(s_waits);CHKERRQ(ierr);
3964   ierr = PetscFree(r_waits);CHKERRQ(ierr);
3965 
3966   /* insert mat values of mpimat */
3967   /*----------------------------*/
3968   ierr = PetscMalloc1(N,&ba_i);CHKERRQ(ierr);
3969   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
3970 
3971   for (k=0; k<merge->nrecv; k++) {
3972     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
3973     nrows       = *(buf_ri_k[k]);
3974     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
3975     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
3976   }
3977 
3978   /* set values of ba */
3979   m = merge->rowmap->n;
3980   for (i=0; i<m; i++) {
3981     arow = owners[rank] + i;
3982     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
3983     bnzi = bi[i+1] - bi[i];
3984     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
3985 
3986     /* add local non-zero vals of this proc's seqmat into ba */
3987     anzi   = ai[arow+1] - ai[arow];
3988     aj     = a->j + ai[arow];
3989     aa     = a->a + ai[arow];
3990     nextaj = 0;
3991     for (j=0; nextaj<anzi; j++) {
3992       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
3993         ba_i[j] += aa[nextaj++];
3994       }
3995     }
3996 
3997     /* add received vals into ba */
3998     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
3999       /* i-th row */
4000       if (i == *nextrow[k]) {
4001         anzi   = *(nextai[k]+1) - *nextai[k];
4002         aj     = buf_rj[k] + *(nextai[k]);
4003         aa     = abuf_r[k] + *(nextai[k]);
4004         nextaj = 0;
4005         for (j=0; nextaj<anzi; j++) {
4006           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4007             ba_i[j] += aa[nextaj++];
4008           }
4009         }
4010         nextrow[k]++; nextai[k]++;
4011       }
4012     }
4013     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4014   }
4015   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4016   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4017 
4018   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4019   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4020   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4021   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4022   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4023   PetscFunctionReturn(0);
4024 }
4025 
4026 extern PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat);
4027 
4028 #undef __FUNCT__
4029 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJSymbolic"
4030 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4031 {
4032   PetscErrorCode      ierr;
4033   Mat                 B_mpi;
4034   Mat_SeqAIJ          *a=(Mat_SeqAIJ*)seqmat->data;
4035   PetscMPIInt         size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4036   PetscInt            **buf_rj,**buf_ri,**buf_ri_k;
4037   PetscInt            M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4038   PetscInt            len,proc,*dnz,*onz,bs,cbs;
4039   PetscInt            k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4040   PetscInt            nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4041   MPI_Request         *si_waits,*sj_waits,*ri_waits,*rj_waits;
4042   MPI_Status          *status;
4043   PetscFreeSpaceList  free_space=NULL,current_space=NULL;
4044   PetscBT             lnkbt;
4045   Mat_Merge_SeqsToMPI *merge;
4046   PetscContainer      container;
4047 
4048   PetscFunctionBegin;
4049   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4050 
4051   /* make sure it is a PETSc comm */
4052   ierr = PetscCommDuplicate(comm,&comm,NULL);CHKERRQ(ierr);
4053   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4054   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4055 
4056   ierr = PetscNew(&merge);CHKERRQ(ierr);
4057   ierr = PetscMalloc1(size,&status);CHKERRQ(ierr);
4058 
4059   /* determine row ownership */
4060   /*---------------------------------------------------------*/
4061   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4062   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4063   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4064   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4065   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4066   ierr = PetscMalloc1(size,&len_si);CHKERRQ(ierr);
4067   ierr = PetscMalloc1(size,&merge->len_s);CHKERRQ(ierr);
4068 
4069   m      = merge->rowmap->n;
4070   owners = merge->rowmap->range;
4071 
4072   /* determine the number of messages to send, their lengths */
4073   /*---------------------------------------------------------*/
4074   len_s = merge->len_s;
4075 
4076   len          = 0; /* length of buf_si[] */
4077   merge->nsend = 0;
4078   for (proc=0; proc<size; proc++) {
4079     len_si[proc] = 0;
4080     if (proc == rank) {
4081       len_s[proc] = 0;
4082     } else {
4083       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4084       len_s[proc]  = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4085     }
4086     if (len_s[proc]) {
4087       merge->nsend++;
4088       nrows = 0;
4089       for (i=owners[proc]; i<owners[proc+1]; i++) {
4090         if (ai[i+1] > ai[i]) nrows++;
4091       }
4092       len_si[proc] = 2*(nrows+1);
4093       len         += len_si[proc];
4094     }
4095   }
4096 
4097   /* determine the number and length of messages to receive for ij-structure */
4098   /*-------------------------------------------------------------------------*/
4099   ierr = PetscGatherNumberOfMessages(comm,NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4100   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4101 
4102   /* post the Irecv of j-structure */
4103   /*-------------------------------*/
4104   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4105   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4106 
4107   /* post the Isend of j-structure */
4108   /*--------------------------------*/
4109   ierr = PetscMalloc2(merge->nsend,&si_waits,merge->nsend,&sj_waits);CHKERRQ(ierr);
4110 
4111   for (proc=0, k=0; proc<size; proc++) {
4112     if (!len_s[proc]) continue;
4113     i    = owners[proc];
4114     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4115     k++;
4116   }
4117 
4118   /* receives and sends of j-structure are complete */
4119   /*------------------------------------------------*/
4120   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4121   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4122 
4123   /* send and recv i-structure */
4124   /*---------------------------*/
4125   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4126   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4127 
4128   ierr   = PetscMalloc1(len+1,&buf_s);CHKERRQ(ierr);
4129   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4130   for (proc=0,k=0; proc<size; proc++) {
4131     if (!len_s[proc]) continue;
4132     /* form outgoing message for i-structure:
4133          buf_si[0]:                 nrows to be sent
4134                [1:nrows]:           row index (global)
4135                [nrows+1:2*nrows+1]: i-structure index
4136     */
4137     /*-------------------------------------------*/
4138     nrows       = len_si[proc]/2 - 1;
4139     buf_si_i    = buf_si + nrows+1;
4140     buf_si[0]   = nrows;
4141     buf_si_i[0] = 0;
4142     nrows       = 0;
4143     for (i=owners[proc]; i<owners[proc+1]; i++) {
4144       anzi = ai[i+1] - ai[i];
4145       if (anzi) {
4146         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4147         buf_si[nrows+1]   = i-owners[proc]; /* local row index */
4148         nrows++;
4149       }
4150     }
4151     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4152     k++;
4153     buf_si += len_si[proc];
4154   }
4155 
4156   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4157   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4158 
4159   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4160   for (i=0; i<merge->nrecv; i++) {
4161     ierr = PetscInfo3(seqmat,"recv len_ri=%D, len_rj=%D from [%D]\n",len_ri[i],merge->len_r[i],merge->id_r[i]);CHKERRQ(ierr);
4162   }
4163 
4164   ierr = PetscFree(len_si);CHKERRQ(ierr);
4165   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4166   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4167   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4168   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4169   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4170   ierr = PetscFree(status);CHKERRQ(ierr);
4171 
4172   /* compute a local seq matrix in each processor */
4173   /*----------------------------------------------*/
4174   /* allocate bi array and free space for accumulating nonzero column info */
4175   ierr  = PetscMalloc1(m+1,&bi);CHKERRQ(ierr);
4176   bi[0] = 0;
4177 
4178   /* create and initialize a linked list */
4179   nlnk = N+1;
4180   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4181 
4182   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4183   len  = ai[owners[rank+1]] - ai[owners[rank]];
4184   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4185 
4186   current_space = free_space;
4187 
4188   /* determine symbolic info for each local row */
4189   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4190 
4191   for (k=0; k<merge->nrecv; k++) {
4192     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4193     nrows       = *buf_ri_k[k];
4194     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4195     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4196   }
4197 
4198   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4199   len  = 0;
4200   for (i=0; i<m; i++) {
4201     bnzi = 0;
4202     /* add local non-zero cols of this proc's seqmat into lnk */
4203     arow  = owners[rank] + i;
4204     anzi  = ai[arow+1] - ai[arow];
4205     aj    = a->j + ai[arow];
4206     ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4207     bnzi += nlnk;
4208     /* add received col data into lnk */
4209     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4210       if (i == *nextrow[k]) { /* i-th row */
4211         anzi  = *(nextai[k]+1) - *nextai[k];
4212         aj    = buf_rj[k] + *nextai[k];
4213         ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4214         bnzi += nlnk;
4215         nextrow[k]++; nextai[k]++;
4216       }
4217     }
4218     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4219 
4220     /* if free space is not available, make more free space */
4221     if (current_space->local_remaining<bnzi) {
4222       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4223       nspacedouble++;
4224     }
4225     /* copy data into free space, then initialize lnk */
4226     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4227     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4228 
4229     current_space->array           += bnzi;
4230     current_space->local_used      += bnzi;
4231     current_space->local_remaining -= bnzi;
4232 
4233     bi[i+1] = bi[i] + bnzi;
4234   }
4235 
4236   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4237 
4238   ierr = PetscMalloc1(bi[m]+1,&bj);CHKERRQ(ierr);
4239   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4240   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4241 
4242   /* create symbolic parallel matrix B_mpi */
4243   /*---------------------------------------*/
4244   ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
4245   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4246   if (n==PETSC_DECIDE) {
4247     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4248   } else {
4249     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4250   }
4251   ierr = MatSetBlockSizes(B_mpi,bs,cbs);CHKERRQ(ierr);
4252   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4253   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4254   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4255   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
4256 
4257   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
4258   B_mpi->assembled    = PETSC_FALSE;
4259   B_mpi->ops->destroy = MatDestroy_MPIAIJ_SeqsToMPI;
4260   merge->bi           = bi;
4261   merge->bj           = bj;
4262   merge->buf_ri       = buf_ri;
4263   merge->buf_rj       = buf_rj;
4264   merge->coi          = NULL;
4265   merge->coj          = NULL;
4266   merge->owners_co    = NULL;
4267 
4268   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4269 
4270   /* attach the supporting struct to B_mpi for reuse */
4271   ierr    = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4272   ierr    = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4273   ierr    = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4274   ierr    = PetscContainerDestroy(&container);CHKERRQ(ierr);
4275   *mpimat = B_mpi;
4276 
4277   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4278   PetscFunctionReturn(0);
4279 }
4280 
4281 #undef __FUNCT__
4282 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJ"
4283 /*@C
4284       MatCreateMPIAIJSumSeqAIJ - Creates a MPIAIJ matrix by adding sequential
4285                  matrices from each processor
4286 
4287     Collective on MPI_Comm
4288 
4289    Input Parameters:
4290 +    comm - the communicators the parallel matrix will live on
4291 .    seqmat - the input sequential matrices
4292 .    m - number of local rows (or PETSC_DECIDE)
4293 .    n - number of local columns (or PETSC_DECIDE)
4294 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4295 
4296    Output Parameter:
4297 .    mpimat - the parallel matrix generated
4298 
4299     Level: advanced
4300 
4301    Notes:
4302      The dimensions of the sequential matrix in each processor MUST be the same.
4303      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
4304      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
4305 @*/
4306 PetscErrorCode  MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4307 {
4308   PetscErrorCode ierr;
4309   PetscMPIInt    size;
4310 
4311   PetscFunctionBegin;
4312   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4313   if (size == 1) {
4314     ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4315     if (scall == MAT_INITIAL_MATRIX) {
4316       ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
4317     } else {
4318       ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4319     }
4320     ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4321     PetscFunctionReturn(0);
4322   }
4323   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4324   if (scall == MAT_INITIAL_MATRIX) {
4325     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4326   }
4327   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
4328   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4329   PetscFunctionReturn(0);
4330 }
4331 
4332 #undef __FUNCT__
4333 #define __FUNCT__ "MatMPIAIJGetLocalMat"
4334 /*@
4335      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
4336           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
4337           with MatGetSize()
4338 
4339     Not Collective
4340 
4341    Input Parameters:
4342 +    A - the matrix
4343 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4344 
4345    Output Parameter:
4346 .    A_loc - the local sequential matrix generated
4347 
4348     Level: developer
4349 
4350 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
4351 
4352 @*/
4353 PetscErrorCode  MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4354 {
4355   PetscErrorCode ierr;
4356   Mat_MPIAIJ     *mpimat=(Mat_MPIAIJ*)A->data;
4357   Mat_SeqAIJ     *mat,*a,*b;
4358   PetscInt       *ai,*aj,*bi,*bj,*cmap=mpimat->garray;
4359   MatScalar      *aa,*ba,*cam;
4360   PetscScalar    *ca;
4361   PetscInt       am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4362   PetscInt       *ci,*cj,col,ncols_d,ncols_o,jo;
4363   PetscBool      match;
4364   MPI_Comm       comm;
4365   PetscMPIInt    size;
4366 
4367   PetscFunctionBegin;
4368   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4369   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
4370   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
4371   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4372   if (size == 1 && scall == MAT_REUSE_MATRIX) PetscFunctionReturn(0);
4373 
4374   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4375   a = (Mat_SeqAIJ*)(mpimat->A)->data;
4376   b = (Mat_SeqAIJ*)(mpimat->B)->data;
4377   ai = a->i; aj = a->j; bi = b->i; bj = b->j;
4378   aa = a->a; ba = b->a;
4379   if (scall == MAT_INITIAL_MATRIX) {
4380     if (size == 1) {
4381       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ai,aj,aa,A_loc);CHKERRQ(ierr);
4382       PetscFunctionReturn(0);
4383     }
4384 
4385     ierr  = PetscMalloc1(1+am,&ci);CHKERRQ(ierr);
4386     ci[0] = 0;
4387     for (i=0; i<am; i++) {
4388       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4389     }
4390     ierr = PetscMalloc1(1+ci[am],&cj);CHKERRQ(ierr);
4391     ierr = PetscMalloc1(1+ci[am],&ca);CHKERRQ(ierr);
4392     k    = 0;
4393     for (i=0; i<am; i++) {
4394       ncols_o = bi[i+1] - bi[i];
4395       ncols_d = ai[i+1] - ai[i];
4396       /* off-diagonal portion of A */
4397       for (jo=0; jo<ncols_o; jo++) {
4398         col = cmap[*bj];
4399         if (col >= cstart) break;
4400         cj[k]   = col; bj++;
4401         ca[k++] = *ba++;
4402       }
4403       /* diagonal portion of A */
4404       for (j=0; j<ncols_d; j++) {
4405         cj[k]   = cstart + *aj++;
4406         ca[k++] = *aa++;
4407       }
4408       /* off-diagonal portion of A */
4409       for (j=jo; j<ncols_o; j++) {
4410         cj[k]   = cmap[*bj++];
4411         ca[k++] = *ba++;
4412       }
4413     }
4414     /* put together the new matrix */
4415     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4416     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4417     /* Since these are PETSc arrays, change flags to free them as necessary. */
4418     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4419     mat->free_a  = PETSC_TRUE;
4420     mat->free_ij = PETSC_TRUE;
4421     mat->nonew   = 0;
4422   } else if (scall == MAT_REUSE_MATRIX) {
4423     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4424     ci = mat->i; cj = mat->j; cam = mat->a;
4425     for (i=0; i<am; i++) {
4426       /* off-diagonal portion of A */
4427       ncols_o = bi[i+1] - bi[i];
4428       for (jo=0; jo<ncols_o; jo++) {
4429         col = cmap[*bj];
4430         if (col >= cstart) break;
4431         *cam++ = *ba++; bj++;
4432       }
4433       /* diagonal portion of A */
4434       ncols_d = ai[i+1] - ai[i];
4435       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4436       /* off-diagonal portion of A */
4437       for (j=jo; j<ncols_o; j++) {
4438         *cam++ = *ba++; bj++;
4439       }
4440     }
4441   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
4442   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4443   PetscFunctionReturn(0);
4444 }
4445 
4446 #undef __FUNCT__
4447 #define __FUNCT__ "MatMPIAIJGetLocalMatCondensed"
4448 /*@C
4449      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MPIAIJ matrix by taking all its local rows and NON-ZERO columns
4450 
4451     Not Collective
4452 
4453    Input Parameters:
4454 +    A - the matrix
4455 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4456 -    row, col - index sets of rows and columns to extract (or NULL)
4457 
4458    Output Parameter:
4459 .    A_loc - the local sequential matrix generated
4460 
4461     Level: developer
4462 
4463 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
4464 
4465 @*/
4466 PetscErrorCode  MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
4467 {
4468   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
4469   PetscErrorCode ierr;
4470   PetscInt       i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
4471   IS             isrowa,iscola;
4472   Mat            *aloc;
4473   PetscBool      match;
4474 
4475   PetscFunctionBegin;
4476   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4477   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
4478   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4479   if (!row) {
4480     start = A->rmap->rstart; end = A->rmap->rend;
4481     ierr  = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
4482   } else {
4483     isrowa = *row;
4484   }
4485   if (!col) {
4486     start = A->cmap->rstart;
4487     cmap  = a->garray;
4488     nzA   = a->A->cmap->n;
4489     nzB   = a->B->cmap->n;
4490     ierr  = PetscMalloc1(nzA+nzB, &idx);CHKERRQ(ierr);
4491     ncols = 0;
4492     for (i=0; i<nzB; i++) {
4493       if (cmap[i] < start) idx[ncols++] = cmap[i];
4494       else break;
4495     }
4496     imark = i;
4497     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
4498     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
4499     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
4500   } else {
4501     iscola = *col;
4502   }
4503   if (scall != MAT_INITIAL_MATRIX) {
4504     ierr    = PetscMalloc1(1,&aloc);CHKERRQ(ierr);
4505     aloc[0] = *A_loc;
4506   }
4507   ierr   = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
4508   *A_loc = aloc[0];
4509   ierr   = PetscFree(aloc);CHKERRQ(ierr);
4510   if (!row) {
4511     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
4512   }
4513   if (!col) {
4514     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
4515   }
4516   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4517   PetscFunctionReturn(0);
4518 }
4519 
4520 #undef __FUNCT__
4521 #define __FUNCT__ "MatGetBrowsOfAcols"
4522 /*@C
4523     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
4524 
4525     Collective on Mat
4526 
4527    Input Parameters:
4528 +    A,B - the matrices in mpiaij format
4529 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4530 -    rowb, colb - index sets of rows and columns of B to extract (or NULL)
4531 
4532    Output Parameter:
4533 +    rowb, colb - index sets of rows and columns of B to extract
4534 -    B_seq - the sequential matrix generated
4535 
4536     Level: developer
4537 
4538 @*/
4539 PetscErrorCode  MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
4540 {
4541   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
4542   PetscErrorCode ierr;
4543   PetscInt       *idx,i,start,ncols,nzA,nzB,*cmap,imark;
4544   IS             isrowb,iscolb;
4545   Mat            *bseq=NULL;
4546 
4547   PetscFunctionBegin;
4548   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
4549     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%D, %D) != (%D,%D)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
4550   }
4551   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
4552 
4553   if (scall == MAT_INITIAL_MATRIX) {
4554     start = A->cmap->rstart;
4555     cmap  = a->garray;
4556     nzA   = a->A->cmap->n;
4557     nzB   = a->B->cmap->n;
4558     ierr  = PetscMalloc1(nzA+nzB, &idx);CHKERRQ(ierr);
4559     ncols = 0;
4560     for (i=0; i<nzB; i++) {  /* row < local row index */
4561       if (cmap[i] < start) idx[ncols++] = cmap[i];
4562       else break;
4563     }
4564     imark = i;
4565     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
4566     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
4567     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
4568     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
4569   } else {
4570     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
4571     isrowb  = *rowb; iscolb = *colb;
4572     ierr    = PetscMalloc1(1,&bseq);CHKERRQ(ierr);
4573     bseq[0] = *B_seq;
4574   }
4575   ierr   = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
4576   *B_seq = bseq[0];
4577   ierr   = PetscFree(bseq);CHKERRQ(ierr);
4578   if (!rowb) {
4579     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
4580   } else {
4581     *rowb = isrowb;
4582   }
4583   if (!colb) {
4584     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
4585   } else {
4586     *colb = iscolb;
4587   }
4588   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
4589   PetscFunctionReturn(0);
4590 }
4591 
4592 #undef __FUNCT__
4593 #define __FUNCT__ "MatGetBrowsOfAoCols_MPIAIJ"
4594 /*
4595     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
4596     of the OFF-DIAGONAL portion of local A
4597 
4598     Collective on Mat
4599 
4600    Input Parameters:
4601 +    A,B - the matrices in mpiaij format
4602 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4603 
4604    Output Parameter:
4605 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
4606 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
4607 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
4608 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
4609 
4610     Level: developer
4611 
4612 */
4613 PetscErrorCode  MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
4614 {
4615   VecScatter_MPI_General *gen_to,*gen_from;
4616   PetscErrorCode         ierr;
4617   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
4618   Mat_SeqAIJ             *b_oth;
4619   VecScatter             ctx =a->Mvctx;
4620   MPI_Comm               comm;
4621   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
4622   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
4623   PetscScalar            *rvalues,*svalues;
4624   MatScalar              *b_otha,*bufa,*bufA;
4625   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
4626   MPI_Request            *rwaits = NULL,*swaits = NULL;
4627   MPI_Status             *sstatus,rstatus;
4628   PetscMPIInt            jj,size;
4629   PetscInt               *cols,sbs,rbs;
4630   PetscScalar            *vals;
4631 
4632   PetscFunctionBegin;
4633   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
4634   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4635 
4636   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
4637     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%d, %d) != (%d,%d)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
4638   }
4639   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
4640   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4641 
4642   gen_to   = (VecScatter_MPI_General*)ctx->todata;
4643   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
4644   rvalues  = gen_from->values; /* holds the length of receiving row */
4645   svalues  = gen_to->values;   /* holds the length of sending row */
4646   nrecvs   = gen_from->n;
4647   nsends   = gen_to->n;
4648 
4649   ierr    = PetscMalloc2(nrecvs,&rwaits,nsends,&swaits);CHKERRQ(ierr);
4650   srow    = gen_to->indices;    /* local row index to be sent */
4651   sstarts = gen_to->starts;
4652   sprocs  = gen_to->procs;
4653   sstatus = gen_to->sstatus;
4654   sbs     = gen_to->bs;
4655   rstarts = gen_from->starts;
4656   rprocs  = gen_from->procs;
4657   rbs     = gen_from->bs;
4658 
4659   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
4660   if (scall == MAT_INITIAL_MATRIX) {
4661     /* i-array */
4662     /*---------*/
4663     /*  post receives */
4664     for (i=0; i<nrecvs; i++) {
4665       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
4666       nrows  = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
4667       ierr   = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4668     }
4669 
4670     /* pack the outgoing message */
4671     ierr = PetscMalloc2(nsends+1,&sstartsj,nrecvs+1,&rstartsj);CHKERRQ(ierr);
4672 
4673     sstartsj[0] = 0;
4674     rstartsj[0] = 0;
4675     len         = 0; /* total length of j or a array to be sent */
4676     k           = 0;
4677     for (i=0; i<nsends; i++) {
4678       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
4679       nrows  = sstarts[i+1]-sstarts[i]; /* num of block rows */
4680       for (j=0; j<nrows; j++) {
4681         row = srow[k] + B->rmap->range[rank]; /* global row idx */
4682         for (l=0; l<sbs; l++) {
4683           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr); /* rowlength */
4684 
4685           rowlen[j*sbs+l] = ncols;
4686 
4687           len += ncols;
4688           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr);
4689         }
4690         k++;
4691       }
4692       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4693 
4694       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
4695     }
4696     /* recvs and sends of i-array are completed */
4697     i = nrecvs;
4698     while (i--) {
4699       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4700     }
4701     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4702 
4703     /* allocate buffers for sending j and a arrays */
4704     ierr = PetscMalloc1(len+1,&bufj);CHKERRQ(ierr);
4705     ierr = PetscMalloc1(len+1,&bufa);CHKERRQ(ierr);
4706 
4707     /* create i-array of B_oth */
4708     ierr = PetscMalloc1(aBn+2,&b_othi);CHKERRQ(ierr);
4709 
4710     b_othi[0] = 0;
4711     len       = 0; /* total length of j or a array to be received */
4712     k         = 0;
4713     for (i=0; i<nrecvs; i++) {
4714       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
4715       nrows  = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
4716       for (j=0; j<nrows; j++) {
4717         b_othi[k+1] = b_othi[k] + rowlen[j];
4718         len        += rowlen[j]; k++;
4719       }
4720       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
4721     }
4722 
4723     /* allocate space for j and a arrrays of B_oth */
4724     ierr = PetscMalloc1(b_othi[aBn]+1,&b_othj);CHKERRQ(ierr);
4725     ierr = PetscMalloc1(b_othi[aBn]+1,&b_otha);CHKERRQ(ierr);
4726 
4727     /* j-array */
4728     /*---------*/
4729     /*  post receives of j-array */
4730     for (i=0; i<nrecvs; i++) {
4731       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
4732       ierr  = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4733     }
4734 
4735     /* pack the outgoing message j-array */
4736     k = 0;
4737     for (i=0; i<nsends; i++) {
4738       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4739       bufJ  = bufj+sstartsj[i];
4740       for (j=0; j<nrows; j++) {
4741         row = srow[k++] + B->rmap->range[rank];  /* global row idx */
4742         for (ll=0; ll<sbs; ll++) {
4743           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
4744           for (l=0; l<ncols; l++) {
4745             *bufJ++ = cols[l];
4746           }
4747           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
4748         }
4749       }
4750       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4751     }
4752 
4753     /* recvs and sends of j-array are completed */
4754     i = nrecvs;
4755     while (i--) {
4756       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4757     }
4758     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4759   } else if (scall == MAT_REUSE_MATRIX) {
4760     sstartsj = *startsj_s;
4761     rstartsj = *startsj_r;
4762     bufa     = *bufa_ptr;
4763     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
4764     b_otha   = b_oth->a;
4765   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
4766 
4767   /* a-array */
4768   /*---------*/
4769   /*  post receives of a-array */
4770   for (i=0; i<nrecvs; i++) {
4771     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
4772     ierr  = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4773   }
4774 
4775   /* pack the outgoing message a-array */
4776   k = 0;
4777   for (i=0; i<nsends; i++) {
4778     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4779     bufA  = bufa+sstartsj[i];
4780     for (j=0; j<nrows; j++) {
4781       row = srow[k++] + B->rmap->range[rank];  /* global row idx */
4782       for (ll=0; ll<sbs; ll++) {
4783         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
4784         for (l=0; l<ncols; l++) {
4785           *bufA++ = vals[l];
4786         }
4787         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
4788       }
4789     }
4790     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4791   }
4792   /* recvs and sends of a-array are completed */
4793   i = nrecvs;
4794   while (i--) {
4795     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4796   }
4797   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4798   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
4799 
4800   if (scall == MAT_INITIAL_MATRIX) {
4801     /* put together the new matrix */
4802     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
4803 
4804     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4805     /* Since these are PETSc arrays, change flags to free them as necessary. */
4806     b_oth          = (Mat_SeqAIJ*)(*B_oth)->data;
4807     b_oth->free_a  = PETSC_TRUE;
4808     b_oth->free_ij = PETSC_TRUE;
4809     b_oth->nonew   = 0;
4810 
4811     ierr = PetscFree(bufj);CHKERRQ(ierr);
4812     if (!startsj_s || !bufa_ptr) {
4813       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
4814       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
4815     } else {
4816       *startsj_s = sstartsj;
4817       *startsj_r = rstartsj;
4818       *bufa_ptr  = bufa;
4819     }
4820   }
4821   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
4822   PetscFunctionReturn(0);
4823 }
4824 
4825 #undef __FUNCT__
4826 #define __FUNCT__ "MatGetCommunicationStructs"
4827 /*@C
4828   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
4829 
4830   Not Collective
4831 
4832   Input Parameters:
4833 . A - The matrix in mpiaij format
4834 
4835   Output Parameter:
4836 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
4837 . colmap - A map from global column index to local index into lvec
4838 - multScatter - A scatter from the argument of a matrix-vector product to lvec
4839 
4840   Level: developer
4841 
4842 @*/
4843 #if defined(PETSC_USE_CTABLE)
4844 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
4845 #else
4846 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
4847 #endif
4848 {
4849   Mat_MPIAIJ *a;
4850 
4851   PetscFunctionBegin;
4852   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
4853   PetscValidPointer(lvec, 2);
4854   PetscValidPointer(colmap, 3);
4855   PetscValidPointer(multScatter, 4);
4856   a = (Mat_MPIAIJ*) A->data;
4857   if (lvec) *lvec = a->lvec;
4858   if (colmap) *colmap = a->colmap;
4859   if (multScatter) *multScatter = a->Mvctx;
4860   PetscFunctionReturn(0);
4861 }
4862 
4863 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat,MatType,MatReuse,Mat*);
4864 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat,MatType,MatReuse,Mat*);
4865 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat,MatType,MatReuse,Mat*);
4866 #if defined(PETSC_HAVE_ELEMENTAL)
4867 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat,MatType,MatReuse,Mat*);
4868 #endif
4869 
4870 #undef __FUNCT__
4871 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
4872 /*
4873     Computes (B'*A')' since computing B*A directly is untenable
4874 
4875                n                       p                          p
4876         (              )       (              )         (                  )
4877       m (      A       )  *  n (       B      )   =   m (         C        )
4878         (              )       (              )         (                  )
4879 
4880 */
4881 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
4882 {
4883   PetscErrorCode ierr;
4884   Mat            At,Bt,Ct;
4885 
4886   PetscFunctionBegin;
4887   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
4888   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
4889   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
4890   ierr = MatDestroy(&At);CHKERRQ(ierr);
4891   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
4892   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
4893   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
4894   PetscFunctionReturn(0);
4895 }
4896 
4897 #undef __FUNCT__
4898 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
4899 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
4900 {
4901   PetscErrorCode ierr;
4902   PetscInt       m=A->rmap->n,n=B->cmap->n;
4903   Mat            Cmat;
4904 
4905   PetscFunctionBegin;
4906   if (A->cmap->n != B->rmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"A->cmap->n %d != B->rmap->n %d\n",A->cmap->n,B->rmap->n);
4907   ierr = MatCreate(PetscObjectComm((PetscObject)A),&Cmat);CHKERRQ(ierr);
4908   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4909   ierr = MatSetBlockSizesFromMats(Cmat,A,B);CHKERRQ(ierr);
4910   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
4911   ierr = MatMPIDenseSetPreallocation(Cmat,NULL);CHKERRQ(ierr);
4912   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4913   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4914 
4915   Cmat->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
4916 
4917   *C = Cmat;
4918   PetscFunctionReturn(0);
4919 }
4920 
4921 /* ----------------------------------------------------------------*/
4922 #undef __FUNCT__
4923 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
4924 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
4925 {
4926   PetscErrorCode ierr;
4927 
4928   PetscFunctionBegin;
4929   if (scall == MAT_INITIAL_MATRIX) {
4930     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
4931     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
4932     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
4933   }
4934   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
4935   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
4936   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
4937   PetscFunctionReturn(0);
4938 }
4939 
4940 /*MC
4941    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
4942 
4943    Options Database Keys:
4944 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
4945 
4946   Level: beginner
4947 
4948 .seealso: MatCreateAIJ()
4949 M*/
4950 
4951 #undef __FUNCT__
4952 #define __FUNCT__ "MatCreate_MPIAIJ"
4953 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
4954 {
4955   Mat_MPIAIJ     *b;
4956   PetscErrorCode ierr;
4957   PetscMPIInt    size;
4958 
4959   PetscFunctionBegin;
4960   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)B),&size);CHKERRQ(ierr);
4961 
4962   ierr          = PetscNewLog(B,&b);CHKERRQ(ierr);
4963   B->data       = (void*)b;
4964   ierr          = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
4965   B->assembled  = PETSC_FALSE;
4966   B->insertmode = NOT_SET_VALUES;
4967   b->size       = size;
4968 
4969   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)B),&b->rank);CHKERRQ(ierr);
4970 
4971   /* build cache for off array entries formed */
4972   ierr = MatStashCreate_Private(PetscObjectComm((PetscObject)B),1,&B->stash);CHKERRQ(ierr);
4973 
4974   b->donotstash  = PETSC_FALSE;
4975   b->colmap      = 0;
4976   b->garray      = 0;
4977   b->roworiented = PETSC_TRUE;
4978 
4979   /* stuff used for matrix vector multiply */
4980   b->lvec  = NULL;
4981   b->Mvctx = NULL;
4982 
4983   /* stuff for MatGetRow() */
4984   b->rowindices   = 0;
4985   b->rowvalues    = 0;
4986   b->getrowactive = PETSC_FALSE;
4987 
4988   /* flexible pointer used in CUSP/CUSPARSE classes */
4989   b->spptr = NULL;
4990 
4991   ierr = PetscObjectComposeFunction((PetscObject)B,"MatStoreValues_C",MatStoreValues_MPIAIJ);CHKERRQ(ierr);
4992   ierr = PetscObjectComposeFunction((PetscObject)B,"MatRetrieveValues_C",MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
4993   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetDiagonalBlock_C",MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
4994   ierr = PetscObjectComposeFunction((PetscObject)B,"MatIsTranspose_C",MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
4995   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
4996   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
4997   ierr = PetscObjectComposeFunction((PetscObject)B,"MatDiagonalScaleLocal_C",MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
4998   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
4999   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5000   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5001 #if defined(PETSC_HAVE_ELEMENTAL)
5002   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_elemental_C",MatConvert_MPIAIJ_Elemental);CHKERRQ(ierr);
5003 #endif
5004   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5005   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5006   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5007   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5008   PetscFunctionReturn(0);
5009 }
5010 
5011 #undef __FUNCT__
5012 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5013 /*@C
5014      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5015          and "off-diagonal" part of the matrix in CSR format.
5016 
5017    Collective on MPI_Comm
5018 
5019    Input Parameters:
5020 +  comm - MPI communicator
5021 .  m - number of local rows (Cannot be PETSC_DECIDE)
5022 .  n - This value should be the same as the local size used in creating the
5023        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5024        calculated if N is given) For square matrices n is almost always m.
5025 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5026 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5027 .   i - row indices for "diagonal" portion of matrix
5028 .   j - column indices
5029 .   a - matrix values
5030 .   oi - row indices for "off-diagonal" portion of matrix
5031 .   oj - column indices
5032 -   oa - matrix values
5033 
5034    Output Parameter:
5035 .   mat - the matrix
5036 
5037    Level: advanced
5038 
5039    Notes:
5040        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5041        must free the arrays once the matrix has been destroyed and not before.
5042 
5043        The i and j indices are 0 based
5044 
5045        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5046 
5047        This sets local rows and cannot be used to set off-processor values.
5048 
5049        Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
5050        legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
5051        not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
5052        the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
5053        keep track of the underlying array. Use MatSetOption(A,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE) to disable all
5054        communication if it is known that only local entries will be set.
5055 
5056 .keywords: matrix, aij, compressed row, sparse, parallel
5057 
5058 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5059           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5060 @*/
5061 PetscErrorCode  MatCreateMPIAIJWithSplitArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt i[],PetscInt j[],PetscScalar a[],PetscInt oi[], PetscInt oj[],PetscScalar oa[],Mat *mat)
5062 {
5063   PetscErrorCode ierr;
5064   Mat_MPIAIJ     *maij;
5065 
5066   PetscFunctionBegin;
5067   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5068   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5069   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5070   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5071   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5072   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5073   maij = (Mat_MPIAIJ*) (*mat)->data;
5074 
5075   (*mat)->preallocated = PETSC_TRUE;
5076 
5077   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5078   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5079 
5080   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5081   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5082 
5083   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5084   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5085   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5086   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5087 
5088   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5089   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5090   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
5091   PetscFunctionReturn(0);
5092 }
5093 
5094 /*
5095     Special version for direct calls from Fortran
5096 */
5097 #include <petsc/private/fortranimpl.h>
5098 
5099 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5100 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5101 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5102 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5103 #endif
5104 
5105 /* Change these macros so can be used in void function */
5106 #undef CHKERRQ
5107 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5108 #undef SETERRQ2
5109 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5110 #undef SETERRQ3
5111 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5112 #undef SETERRQ
5113 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5114 
5115 #undef __FUNCT__
5116 #define __FUNCT__ "matsetvaluesmpiaij_"
5117 PETSC_EXTERN void PETSC_STDCALL matsetvaluesmpiaij_(Mat *mmat,PetscInt *mm,const PetscInt im[],PetscInt *mn,const PetscInt in[],const PetscScalar v[],InsertMode *maddv,PetscErrorCode *_ierr)
5118 {
5119   Mat            mat  = *mmat;
5120   PetscInt       m    = *mm, n = *mn;
5121   InsertMode     addv = *maddv;
5122   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
5123   PetscScalar    value;
5124   PetscErrorCode ierr;
5125 
5126   MatCheckPreallocated(mat,1);
5127   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
5128 
5129 #if defined(PETSC_USE_DEBUG)
5130   else if (mat->insertmode != addv) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5131 #endif
5132   {
5133     PetscInt  i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
5134     PetscInt  cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5135     PetscBool roworiented = aij->roworiented;
5136 
5137     /* Some Variables required in the macro */
5138     Mat        A                 = aij->A;
5139     Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
5140     PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5141     MatScalar  *aa               = a->a;
5142     PetscBool  ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
5143     Mat        B                 = aij->B;
5144     Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
5145     PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5146     MatScalar  *ba               = b->a;
5147 
5148     PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5149     PetscInt  nonew = a->nonew;
5150     MatScalar *ap1,*ap2;
5151 
5152     PetscFunctionBegin;
5153     for (i=0; i<m; i++) {
5154       if (im[i] < 0) continue;
5155 #if defined(PETSC_USE_DEBUG)
5156       if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
5157 #endif
5158       if (im[i] >= rstart && im[i] < rend) {
5159         row      = im[i] - rstart;
5160         lastcol1 = -1;
5161         rp1      = aj + ai[row];
5162         ap1      = aa + ai[row];
5163         rmax1    = aimax[row];
5164         nrow1    = ailen[row];
5165         low1     = 0;
5166         high1    = nrow1;
5167         lastcol2 = -1;
5168         rp2      = bj + bi[row];
5169         ap2      = ba + bi[row];
5170         rmax2    = bimax[row];
5171         nrow2    = bilen[row];
5172         low2     = 0;
5173         high2    = nrow2;
5174 
5175         for (j=0; j<n; j++) {
5176           if (roworiented) value = v[i*n+j];
5177           else value = v[i+j*m];
5178           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5179           if (in[j] >= cstart && in[j] < cend) {
5180             col = in[j] - cstart;
5181             MatSetValues_SeqAIJ_A_Private(row,col,value,addv,im[i],in[j]);
5182           } else if (in[j] < 0) continue;
5183 #if defined(PETSC_USE_DEBUG)
5184           else if (in[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);
5185 #endif
5186           else {
5187             if (mat->was_assembled) {
5188               if (!aij->colmap) {
5189                 ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5190               }
5191 #if defined(PETSC_USE_CTABLE)
5192               ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5193               col--;
5194 #else
5195               col = aij->colmap[in[j]] - 1;
5196 #endif
5197               if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5198                 ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5199                 col  =  in[j];
5200                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5201                 B     = aij->B;
5202                 b     = (Mat_SeqAIJ*)B->data;
5203                 bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5204                 rp2   = bj + bi[row];
5205                 ap2   = ba + bi[row];
5206                 rmax2 = bimax[row];
5207                 nrow2 = bilen[row];
5208                 low2  = 0;
5209                 high2 = nrow2;
5210                 bm    = aij->B->rmap->n;
5211                 ba    = b->a;
5212               }
5213             } else col = in[j];
5214             MatSetValues_SeqAIJ_B_Private(row,col,value,addv,im[i],in[j]);
5215           }
5216         }
5217       } else if (!aij->donotstash) {
5218         if (roworiented) {
5219           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5220         } else {
5221           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5222         }
5223       }
5224     }
5225   }
5226   PetscFunctionReturnVoid();
5227 }
5228 
5229