xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 5e49412c8a17aeaca39d74026da899260f5f63d4)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>   /*I "petscmat.h" I*/
3 #include <petsc-private/vecimpl.h>
4 #include <petscblaslapack.h>
5 #include <petscsf.h>
6 
7 /*MC
8    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
9 
10    This matrix type is identical to MATSEQAIJ when constructed with a single process communicator,
11    and MATMPIAIJ otherwise.  As a result, for single process communicators,
12   MatSeqAIJSetPreallocation is supported, and similarly MatMPIAIJSetPreallocation is supported
13   for communicators controlling multiple processes.  It is recommended that you call both of
14   the above preallocation routines for simplicity.
15 
16    Options Database Keys:
17 . -mat_type aij - sets the matrix type to "aij" during a call to MatSetFromOptions()
18 
19   Developer Notes: Subclasses include MATAIJCUSP, MATAIJCUSPARSE, MATAIJPERM, MATAIJCRL, and also automatically switches over to use inodes when
20    enough exist.
21 
22   Level: beginner
23 
24 .seealso: MatCreateAIJ(), MatCreateSeqAIJ(), MATSEQAIJ,MATMPIAIJ
25 M*/
26 
27 /*MC
28    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
29 
30    This matrix type is identical to MATSEQAIJCRL when constructed with a single process communicator,
31    and MATMPIAIJCRL otherwise.  As a result, for single process communicators,
32    MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
33   for communicators controlling multiple processes.  It is recommended that you call both of
34   the above preallocation routines for simplicity.
35 
36    Options Database Keys:
37 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to MatSetFromOptions()
38 
39   Level: beginner
40 
41 .seealso: MatCreateMPIAIJCRL,MATSEQAIJCRL,MATMPIAIJCRL, MATSEQAIJCRL, MATMPIAIJCRL
42 M*/
43 
44 #undef __FUNCT__
45 #define __FUNCT__ "MatFindNonzeroRows_MPIAIJ"
46 PetscErrorCode MatFindNonzeroRows_MPIAIJ(Mat M,IS *keptrows)
47 {
48   PetscErrorCode  ierr;
49   Mat_MPIAIJ      *mat = (Mat_MPIAIJ*)M->data;
50   Mat_SeqAIJ      *a   = (Mat_SeqAIJ*)mat->A->data;
51   Mat_SeqAIJ      *b   = (Mat_SeqAIJ*)mat->B->data;
52   const PetscInt  *ia,*ib;
53   const MatScalar *aa,*bb;
54   PetscInt        na,nb,i,j,*rows,cnt=0,n0rows;
55   PetscInt        m = M->rmap->n,rstart = M->rmap->rstart;
56 
57   PetscFunctionBegin;
58   *keptrows = 0;
59   ia        = a->i;
60   ib        = b->i;
61   for (i=0; i<m; i++) {
62     na = ia[i+1] - ia[i];
63     nb = ib[i+1] - ib[i];
64     if (!na && !nb) {
65       cnt++;
66       goto ok1;
67     }
68     aa = a->a + ia[i];
69     for (j=0; j<na; j++) {
70       if (aa[j] != 0.0) goto ok1;
71     }
72     bb = b->a + ib[i];
73     for (j=0; j <nb; j++) {
74       if (bb[j] != 0.0) goto ok1;
75     }
76     cnt++;
77 ok1:;
78   }
79   ierr = MPI_Allreduce(&cnt,&n0rows,1,MPIU_INT,MPIU_SUM,PetscObjectComm((PetscObject)M));CHKERRQ(ierr);
80   if (!n0rows) PetscFunctionReturn(0);
81   ierr = PetscMalloc1((M->rmap->n-cnt),&rows);CHKERRQ(ierr);
82   cnt  = 0;
83   for (i=0; i<m; i++) {
84     na = ia[i+1] - ia[i];
85     nb = ib[i+1] - ib[i];
86     if (!na && !nb) continue;
87     aa = a->a + ia[i];
88     for (j=0; j<na;j++) {
89       if (aa[j] != 0.0) {
90         rows[cnt++] = rstart + i;
91         goto ok2;
92       }
93     }
94     bb = b->a + ib[i];
95     for (j=0; j<nb; j++) {
96       if (bb[j] != 0.0) {
97         rows[cnt++] = rstart + i;
98         goto ok2;
99       }
100     }
101 ok2:;
102   }
103   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),cnt,rows,PETSC_OWN_POINTER,keptrows);CHKERRQ(ierr);
104   PetscFunctionReturn(0);
105 }
106 
107 #undef __FUNCT__
108 #define __FUNCT__ "MatDiagonalSet_MPIAIJ"
109 PetscErrorCode  MatDiagonalSet_MPIAIJ(Mat Y,Vec D,InsertMode is)
110 {
111   PetscErrorCode    ierr;
112   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*) Y->data;
113 
114   PetscFunctionBegin;
115   if (Y->assembled && Y->rmap->rstart == Y->cmap->rstart && Y->rmap->rend == Y->cmap->rend) {
116     ierr = MatDiagonalSet(aij->A,D,is);CHKERRQ(ierr);
117   } else {
118     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
119   }
120   PetscFunctionReturn(0);
121 }
122 
123 
124 #undef __FUNCT__
125 #define __FUNCT__ "MatFindZeroDiagonals_MPIAIJ"
126 PetscErrorCode MatFindZeroDiagonals_MPIAIJ(Mat M,IS *zrows)
127 {
128   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)M->data;
129   PetscErrorCode ierr;
130   PetscInt       i,rstart,nrows,*rows;
131 
132   PetscFunctionBegin;
133   *zrows = NULL;
134   ierr   = MatFindZeroDiagonals_SeqAIJ_Private(aij->A,&nrows,&rows);CHKERRQ(ierr);
135   ierr   = MatGetOwnershipRange(M,&rstart,NULL);CHKERRQ(ierr);
136   for (i=0; i<nrows; i++) rows[i] += rstart;
137   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),nrows,rows,PETSC_OWN_POINTER,zrows);CHKERRQ(ierr);
138   PetscFunctionReturn(0);
139 }
140 
141 #undef __FUNCT__
142 #define __FUNCT__ "MatGetColumnNorms_MPIAIJ"
143 PetscErrorCode MatGetColumnNorms_MPIAIJ(Mat A,NormType type,PetscReal *norms)
144 {
145   PetscErrorCode ierr;
146   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)A->data;
147   PetscInt       i,n,*garray = aij->garray;
148   Mat_SeqAIJ     *a_aij = (Mat_SeqAIJ*) aij->A->data;
149   Mat_SeqAIJ     *b_aij = (Mat_SeqAIJ*) aij->B->data;
150   PetscReal      *work;
151 
152   PetscFunctionBegin;
153   ierr = MatGetSize(A,NULL,&n);CHKERRQ(ierr);
154   ierr = PetscCalloc1(n,&work);CHKERRQ(ierr);
155   if (type == NORM_2) {
156     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
157       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]*a_aij->a[i]);
158     }
159     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
160       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]*b_aij->a[i]);
161     }
162   } else if (type == NORM_1) {
163     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
164       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
165     }
166     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
167       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
168     }
169   } else if (type == NORM_INFINITY) {
170     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
171       work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
172     }
173     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
174       work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]),work[garray[b_aij->j[i]]]);
175     }
176 
177   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONG,"Unknown NormType");
178   if (type == NORM_INFINITY) {
179     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
180   } else {
181     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
182   }
183   ierr = PetscFree(work);CHKERRQ(ierr);
184   if (type == NORM_2) {
185     for (i=0; i<n; i++) norms[i] = PetscSqrtReal(norms[i]);
186   }
187   PetscFunctionReturn(0);
188 }
189 
190 #undef __FUNCT__
191 #define __FUNCT__ "MatDistribute_MPIAIJ"
192 /*
193     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
194     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
195 
196     Only for square matrices
197 
198     Used by a preconditioner, hence PETSC_EXTERN
199 */
200 PETSC_EXTERN PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
201 {
202   PetscMPIInt    rank,size;
203   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz = 0,*gmataj,cnt,row,*ld,bses[2];
204   PetscErrorCode ierr;
205   Mat            mat;
206   Mat_SeqAIJ     *gmata;
207   PetscMPIInt    tag;
208   MPI_Status     status;
209   PetscBool      aij;
210   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
211 
212   PetscFunctionBegin;
213   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
214   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
215   if (!rank) {
216     ierr = PetscObjectTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
217     if (!aij) SETERRQ1(PetscObjectComm((PetscObject)gmat),PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
218   }
219   if (reuse == MAT_INITIAL_MATRIX) {
220     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
221     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
222     ierr = MatGetBlockSizes(gmat,&bses[0],&bses[1]);CHKERRQ(ierr);
223     ierr = MPI_Bcast(bses,2,MPIU_INT,0,comm);CHKERRQ(ierr);
224     ierr = MatSetBlockSizes(mat,bses[0],bses[1]);CHKERRQ(ierr);
225     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
226     ierr = PetscMalloc1((size+1),&rowners);CHKERRQ(ierr);
227     ierr = PetscMalloc2(m,&dlens,m,&olens);CHKERRQ(ierr);
228     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
229 
230     rowners[0] = 0;
231     for (i=2; i<=size; i++) rowners[i] += rowners[i-1];
232     rstart = rowners[rank];
233     rend   = rowners[rank+1];
234     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
235     if (!rank) {
236       gmata = (Mat_SeqAIJ*) gmat->data;
237       /* send row lengths to all processors */
238       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
239       for (i=1; i<size; i++) {
240         ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
241       }
242       /* determine number diagonal and off-diagonal counts */
243       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
244       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
245       jj   = 0;
246       for (i=0; i<m; i++) {
247         for (j=0; j<dlens[i]; j++) {
248           if (gmata->j[jj] < rstart) ld[i]++;
249           if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
250           jj++;
251         }
252       }
253       /* send column indices to other processes */
254       for (i=1; i<size; i++) {
255         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
256         ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
257         ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
258       }
259 
260       /* send numerical values to other processes */
261       for (i=1; i<size; i++) {
262         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
263         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
264       }
265       gmataa = gmata->a;
266       gmataj = gmata->j;
267 
268     } else {
269       /* receive row lengths */
270       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
271       /* receive column indices */
272       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
273       ierr = PetscMalloc2(nz,&gmataa,nz,&gmataj);CHKERRQ(ierr);
274       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
275       /* determine number diagonal and off-diagonal counts */
276       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
277       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
278       jj   = 0;
279       for (i=0; i<m; i++) {
280         for (j=0; j<dlens[i]; j++) {
281           if (gmataj[jj] < rstart) ld[i]++;
282           if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
283           jj++;
284         }
285       }
286       /* receive numerical values */
287       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
288       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
289     }
290     /* set preallocation */
291     for (i=0; i<m; i++) {
292       dlens[i] -= olens[i];
293     }
294     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
295     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
296 
297     for (i=0; i<m; i++) {
298       dlens[i] += olens[i];
299     }
300     cnt = 0;
301     for (i=0; i<m; i++) {
302       row  = rstart + i;
303       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
304       cnt += dlens[i];
305     }
306     if (rank) {
307       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
308     }
309     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
310     ierr = PetscFree(rowners);CHKERRQ(ierr);
311 
312     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
313 
314     *inmat = mat;
315   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
316     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
317     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
318     mat  = *inmat;
319     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
320     if (!rank) {
321       /* send numerical values to other processes */
322       gmata  = (Mat_SeqAIJ*) gmat->data;
323       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
324       gmataa = gmata->a;
325       for (i=1; i<size; i++) {
326         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
327         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
328       }
329       nz = gmata->i[rowners[1]]-gmata->i[rowners[0]];
330     } else {
331       /* receive numerical values from process 0*/
332       nz   = Ad->nz + Ao->nz;
333       ierr = PetscMalloc1(nz,&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
334       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
335     }
336     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
337     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
338     ad = Ad->a;
339     ao = Ao->a;
340     if (mat->rmap->n) {
341       i  = 0;
342       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
343       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
344     }
345     for (i=1; i<mat->rmap->n; i++) {
346       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;
347       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
348     }
349     i--;
350     if (mat->rmap->n) {
351       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
352     }
353     if (rank) {
354       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
355     }
356   }
357   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
358   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
359   PetscFunctionReturn(0);
360 }
361 
362 /*
363   Local utility routine that creates a mapping from the global column
364 number to the local number in the off-diagonal part of the local
365 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
366 a slightly higher hash table cost; without it it is not scalable (each processor
367 has an order N integer array but is fast to acess.
368 */
369 #undef __FUNCT__
370 #define __FUNCT__ "MatCreateColmap_MPIAIJ_Private"
371 PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
372 {
373   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
374   PetscErrorCode ierr;
375   PetscInt       n = aij->B->cmap->n,i;
376 
377   PetscFunctionBegin;
378   if (!aij->garray) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPIAIJ Matrix was assembled but is missing garray");
379 #if defined(PETSC_USE_CTABLE)
380   ierr = PetscTableCreate(n,mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
381   for (i=0; i<n; i++) {
382     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1,INSERT_VALUES);CHKERRQ(ierr);
383   }
384 #else
385   ierr = PetscCalloc1((mat->cmap->N+1),&aij->colmap);CHKERRQ(ierr);
386   ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N+1)*sizeof(PetscInt));CHKERRQ(ierr);
387   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
388 #endif
389   PetscFunctionReturn(0);
390 }
391 
392 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv) \
393 { \
394     if (col <= lastcol1)  low1 = 0;     \
395     else                 high1 = nrow1; \
396     lastcol1 = col;\
397     while (high1-low1 > 5) { \
398       t = (low1+high1)/2; \
399       if (rp1[t] > col) high1 = t; \
400       else              low1  = t; \
401     } \
402       for (_i=low1; _i<high1; _i++) { \
403         if (rp1[_i] > col) break; \
404         if (rp1[_i] == col) { \
405           if (addv == ADD_VALUES) ap1[_i] += value;   \
406           else                    ap1[_i] = value; \
407           goto a_noinsert; \
408         } \
409       }  \
410       if (value == 0.0 && ignorezeroentries) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
411       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}                \
412       if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
413       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
414       N = nrow1++ - 1; a->nz++; high1++; \
415       /* shift up all the later entries in this row */ \
416       for (ii=N; ii>=_i; ii--) { \
417         rp1[ii+1] = rp1[ii]; \
418         ap1[ii+1] = ap1[ii]; \
419       } \
420       rp1[_i] = col;  \
421       ap1[_i] = value;  \
422       A->nonzerostate++;\
423       a_noinsert: ; \
424       ailen[row] = nrow1; \
425 }
426 
427 
428 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv) \
429   { \
430     if (col <= lastcol2) low2 = 0;                        \
431     else high2 = nrow2;                                   \
432     lastcol2 = col;                                       \
433     while (high2-low2 > 5) {                              \
434       t = (low2+high2)/2;                                 \
435       if (rp2[t] > col) high2 = t;                        \
436       else             low2  = t;                         \
437     }                                                     \
438     for (_i=low2; _i<high2; _i++) {                       \
439       if (rp2[_i] > col) break;                           \
440       if (rp2[_i] == col) {                               \
441         if (addv == ADD_VALUES) ap2[_i] += value;         \
442         else                    ap2[_i] = value;          \
443         goto b_noinsert;                                  \
444       }                                                   \
445     }                                                     \
446     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
447     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}                        \
448     if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
449     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
450     N = nrow2++ - 1; b->nz++; high2++;                    \
451     /* shift up all the later entries in this row */      \
452     for (ii=N; ii>=_i; ii--) {                            \
453       rp2[ii+1] = rp2[ii];                                \
454       ap2[ii+1] = ap2[ii];                                \
455     }                                                     \
456     rp2[_i] = col;                                        \
457     ap2[_i] = value;                                      \
458     B->nonzerostate++;                                    \
459     b_noinsert: ;                                         \
460     bilen[row] = nrow2;                                   \
461   }
462 
463 #undef __FUNCT__
464 #define __FUNCT__ "MatSetValuesRow_MPIAIJ"
465 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
466 {
467   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
468   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
469   PetscErrorCode ierr;
470   PetscInt       l,*garray = mat->garray,diag;
471 
472   PetscFunctionBegin;
473   /* code only works for square matrices A */
474 
475   /* find size of row to the left of the diagonal part */
476   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
477   row  = row - diag;
478   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
479     if (garray[b->j[b->i[row]+l]] > diag) break;
480   }
481   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
482 
483   /* diagonal part */
484   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
485 
486   /* right of diagonal part */
487   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);
488   PetscFunctionReturn(0);
489 }
490 
491 #undef __FUNCT__
492 #define __FUNCT__ "MatSetValues_MPIAIJ"
493 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
494 {
495   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
496   PetscScalar    value;
497   PetscErrorCode ierr;
498   PetscInt       i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
499   PetscInt       cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
500   PetscBool      roworiented = aij->roworiented;
501 
502   /* Some Variables required in the macro */
503   Mat        A                 = aij->A;
504   Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
505   PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
506   MatScalar  *aa               = a->a;
507   PetscBool  ignorezeroentries = a->ignorezeroentries;
508   Mat        B                 = aij->B;
509   Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
510   PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
511   MatScalar  *ba               = b->a;
512 
513   PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
514   PetscInt  nonew;
515   MatScalar *ap1,*ap2;
516 
517   PetscFunctionBegin;
518   for (i=0; i<m; i++) {
519     if (im[i] < 0) continue;
520 #if defined(PETSC_USE_DEBUG)
521     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);
522 #endif
523     if (im[i] >= rstart && im[i] < rend) {
524       row      = im[i] - rstart;
525       lastcol1 = -1;
526       rp1      = aj + ai[row];
527       ap1      = aa + ai[row];
528       rmax1    = aimax[row];
529       nrow1    = ailen[row];
530       low1     = 0;
531       high1    = nrow1;
532       lastcol2 = -1;
533       rp2      = bj + bi[row];
534       ap2      = ba + bi[row];
535       rmax2    = bimax[row];
536       nrow2    = bilen[row];
537       low2     = 0;
538       high2    = nrow2;
539 
540       for (j=0; j<n; j++) {
541         if (roworiented) value = v[i*n+j];
542         else             value = v[i+j*m];
543         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
544         if (in[j] >= cstart && in[j] < cend) {
545           col   = in[j] - cstart;
546           nonew = a->nonew;
547           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
548         } else if (in[j] < 0) continue;
549 #if defined(PETSC_USE_DEBUG)
550         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);
551 #endif
552         else {
553           if (mat->was_assembled) {
554             if (!aij->colmap) {
555               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
556             }
557 #if defined(PETSC_USE_CTABLE)
558             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
559             col--;
560 #else
561             col = aij->colmap[in[j]] - 1;
562 #endif
563             if (col < 0 && !((Mat_SeqAIJ*)(aij->B->data))->nonew) {
564               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
565               col  =  in[j];
566               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
567               B     = aij->B;
568               b     = (Mat_SeqAIJ*)B->data;
569               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
570               rp2   = bj + bi[row];
571               ap2   = ba + bi[row];
572               rmax2 = bimax[row];
573               nrow2 = bilen[row];
574               low2  = 0;
575               high2 = nrow2;
576               bm    = aij->B->rmap->n;
577               ba    = b->a;
578             } else if (col < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", im[i], in[j]);
579           } else col = in[j];
580           nonew = b->nonew;
581           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
582         }
583       }
584     } else {
585       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]);
586       if (!aij->donotstash) {
587         mat->assembled = PETSC_FALSE;
588         if (roworiented) {
589           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
590         } else {
591           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
592         }
593       }
594     }
595   }
596   PetscFunctionReturn(0);
597 }
598 
599 #undef __FUNCT__
600 #define __FUNCT__ "MatGetValues_MPIAIJ"
601 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
602 {
603   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
604   PetscErrorCode ierr;
605   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
606   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
607 
608   PetscFunctionBegin;
609   for (i=0; i<m; i++) {
610     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
611     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);
612     if (idxm[i] >= rstart && idxm[i] < rend) {
613       row = idxm[i] - rstart;
614       for (j=0; j<n; j++) {
615         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
616         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);
617         if (idxn[j] >= cstart && idxn[j] < cend) {
618           col  = idxn[j] - cstart;
619           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
620         } else {
621           if (!aij->colmap) {
622             ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
623           }
624 #if defined(PETSC_USE_CTABLE)
625           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
626           col--;
627 #else
628           col = aij->colmap[idxn[j]] - 1;
629 #endif
630           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
631           else {
632             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
633           }
634         }
635       }
636     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only local values currently supported");
637   }
638   PetscFunctionReturn(0);
639 }
640 
641 extern PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat,Vec,Vec);
642 
643 #undef __FUNCT__
644 #define __FUNCT__ "MatAssemblyBegin_MPIAIJ"
645 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
646 {
647   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
648   PetscErrorCode ierr;
649   PetscInt       nstash,reallocs;
650   InsertMode     addv;
651 
652   PetscFunctionBegin;
653   if (aij->donotstash || mat->nooffprocentries) PetscFunctionReturn(0);
654 
655   /* make sure all processors are either in INSERTMODE or ADDMODE */
656   ierr = MPI_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
657   if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
658   mat->insertmode = addv; /* in case this processor had no cache */
659 
660   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
661   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
662   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
663   PetscFunctionReturn(0);
664 }
665 
666 #undef __FUNCT__
667 #define __FUNCT__ "MatAssemblyEnd_MPIAIJ"
668 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
669 {
670   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
671   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)aij->A->data;
672   PetscErrorCode ierr;
673   PetscMPIInt    n;
674   PetscInt       i,j,rstart,ncols,flg;
675   PetscInt       *row,*col;
676   PetscBool      other_disassembled;
677   PetscScalar    *val;
678   InsertMode     addv = mat->insertmode;
679 
680   /* do not use 'b = (Mat_SeqAIJ*)aij->B->data' as B can be reset in disassembly */
681 
682   PetscFunctionBegin;
683   if (!aij->donotstash && !mat->nooffprocentries) {
684     while (1) {
685       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
686       if (!flg) break;
687 
688       for (i=0; i<n; ) {
689         /* Now identify the consecutive vals belonging to the same row */
690         for (j=i,rstart=row[j]; j<n; j++) {
691           if (row[j] != rstart) break;
692         }
693         if (j < n) ncols = j-i;
694         else       ncols = n-i;
695         /* Now assemble all these values with a single function call */
696         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,addv);CHKERRQ(ierr);
697 
698         i = j;
699       }
700     }
701     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
702   }
703   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
704   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
705 
706   /* determine if any processor has disassembled, if so we must
707      also disassemble ourselfs, in order that we may reassemble. */
708   /*
709      if nonzero structure of submatrix B cannot change then we know that
710      no processor disassembled thus we can skip this stuff
711   */
712   if (!((Mat_SeqAIJ*)aij->B->data)->nonew) {
713     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPIU_BOOL,MPI_PROD,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
714     if (mat->was_assembled && !other_disassembled) {
715       ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
716     }
717   }
718   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
719     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
720   }
721   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
722   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
723   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
724 
725   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
726 
727   aij->rowvalues = 0;
728 
729   /* used by MatAXPY() */
730   a->xtoy = 0; ((Mat_SeqAIJ*)aij->B->data)->xtoy = 0;   /* b->xtoy = 0 */
731   a->XtoY = 0; ((Mat_SeqAIJ*)aij->B->data)->XtoY = 0;   /* b->XtoY = 0 */
732 
733   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
734   if (a->inode.size) mat->ops->multdiagonalblock = MatMultDiagonalBlock_MPIAIJ;
735 
736   /* if no new nonzero locations are allowed in matrix then only set the matrix state the first time through */
737   if ((!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) || !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
738     PetscObjectState state = aij->A->nonzerostate + aij->B->nonzerostate;
739     ierr = MPI_Allreduce(&state,&mat->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
740   }
741   PetscFunctionReturn(0);
742 }
743 
744 #undef __FUNCT__
745 #define __FUNCT__ "MatZeroEntries_MPIAIJ"
746 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
747 {
748   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
749   PetscErrorCode ierr;
750 
751   PetscFunctionBegin;
752   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
753   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
754   PetscFunctionReturn(0);
755 }
756 
757 #undef __FUNCT__
758 #define __FUNCT__ "MatZeroRows_MPIAIJ"
759 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
760 {
761   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
762   PetscInt      *owners = A->rmap->range;
763   PetscInt       n      = A->rmap->n;
764   PetscSF        sf;
765   PetscInt      *lrows;
766   PetscSFNode   *rrows;
767   PetscInt       r, p = 0, len = 0;
768   PetscErrorCode ierr;
769 
770   PetscFunctionBegin;
771   /* Create SF where leaves are input rows and roots are owned rows */
772   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
773   for (r = 0; r < n; ++r) lrows[r] = -1;
774   if (!A->nooffproczerorows) {ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);}
775   for (r = 0; r < N; ++r) {
776     const PetscInt idx   = rows[r];
777     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);
778     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
779       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
780     }
781     if (A->nooffproczerorows) {
782       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);
783       lrows[len++] = idx - owners[p];
784     } else {
785       rrows[r].rank = p;
786       rrows[r].index = rows[r] - owners[p];
787     }
788   }
789   if (!A->nooffproczerorows) {
790     ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
791     ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
792     /* Collect flags for rows to be zeroed */
793     ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt*)rows, lrows, MPI_LOR);CHKERRQ(ierr);
794     ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt*)rows, lrows, MPI_LOR);CHKERRQ(ierr);
795     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
796     /* Compress and put in row numbers */
797     for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
798   }
799   /* fix right hand side if needed */
800   if (x && b) {
801     const PetscScalar *xx;
802     PetscScalar       *bb;
803 
804     ierr = VecGetArrayRead(x, &xx);CHKERRQ(ierr);
805     ierr = VecGetArray(b, &bb);CHKERRQ(ierr);
806     for (r = 0; r < len; ++r) bb[lrows[r]] = diag*xx[lrows[r]];
807     ierr = VecRestoreArrayRead(x, &xx);CHKERRQ(ierr);
808     ierr = VecRestoreArray(b, &bb);CHKERRQ(ierr);
809   }
810   /* Must zero l->B before l->A because the (diag) case below may put values into l->B*/
811   ierr = MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
812   if ((diag != 0.0) && (mat->A->rmap->N == mat->A->cmap->N)) {
813     ierr = MatZeroRows(mat->A, len, lrows, diag, NULL, NULL);CHKERRQ(ierr);
814   } else if (diag != 0.0) {
815     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
816     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");
817     for (r = 0; r < len; ++r) {
818       const PetscInt row = lrows[r] + A->rmap->rstart;
819       ierr = MatSetValues(A, 1, &row, 1, &row, &diag, INSERT_VALUES);CHKERRQ(ierr);
820     }
821     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
822     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
823   } else {
824     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
825   }
826   ierr = PetscFree(lrows);CHKERRQ(ierr);
827 
828   /* only change matrix nonzero state if pattern was allowed to be changed */
829   if (!((Mat_SeqAIJ*)(mat->A->data))->keepnonzeropattern) {
830     PetscObjectState state = mat->A->nonzerostate + mat->B->nonzerostate;
831     ierr = MPI_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
832   }
833   PetscFunctionReturn(0);
834 }
835 
836 #undef __FUNCT__
837 #define __FUNCT__ "MatZeroRowsColumns_MPIAIJ"
838 PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
839 {
840   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
841   PetscErrorCode    ierr;
842   PetscMPIInt       n = A->rmap->n;
843   PetscInt          i,j,r,m,p = 0,len = 0;
844   PetscInt          *lrows,*owners = A->rmap->range;
845   PetscSFNode       *rrows;
846   PetscSF           sf;
847   const PetscScalar *xx;
848   PetscScalar       *bb,*mask;
849   Vec               xmask,lmask;
850   Mat_SeqAIJ        *aij = (Mat_SeqAIJ*)l->B->data;
851   const PetscInt    *aj, *ii,*ridx;
852   PetscScalar       *aa;
853 
854   PetscFunctionBegin;
855   /* Create SF where leaves are input rows and roots are owned rows */
856   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
857   for (r = 0; r < n; ++r) lrows[r] = -1;
858   ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);
859   for (r = 0; r < N; ++r) {
860     const PetscInt idx   = rows[r];
861     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);
862     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
863       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
864     }
865     rrows[r].rank  = p;
866     rrows[r].index = rows[r] - owners[p];
867   }
868   ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
869   ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
870   /* Collect flags for rows to be zeroed */
871   ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
872   ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
873   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
874   /* Compress and put in row numbers */
875   for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
876   /* zero diagonal part of matrix */
877   ierr = MatZeroRowsColumns(l->A,len,lrows,diag,x,b);CHKERRQ(ierr);
878   /* handle off diagonal part of matrix */
879   ierr = MatCreateVecs(A,&xmask,NULL);CHKERRQ(ierr);
880   ierr = VecDuplicate(l->lvec,&lmask);CHKERRQ(ierr);
881   ierr = VecGetArray(xmask,&bb);CHKERRQ(ierr);
882   for (i=0; i<len; i++) bb[lrows[i]] = 1;
883   ierr = VecRestoreArray(xmask,&bb);CHKERRQ(ierr);
884   ierr = VecScatterBegin(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
885   ierr = VecScatterEnd(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
886   ierr = VecDestroy(&xmask);CHKERRQ(ierr);
887   if (x) {
888     ierr = VecScatterBegin(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
889     ierr = VecScatterEnd(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
890     ierr = VecGetArrayRead(l->lvec,&xx);CHKERRQ(ierr);
891     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
892   }
893   ierr = VecGetArray(lmask,&mask);CHKERRQ(ierr);
894   /* remove zeroed rows of off diagonal matrix */
895   ii = aij->i;
896   for (i=0; i<len; i++) {
897     ierr = PetscMemzero(aij->a + ii[lrows[i]],(ii[lrows[i]+1] - ii[lrows[i]])*sizeof(PetscScalar));CHKERRQ(ierr);
898   }
899   /* loop over all elements of off process part of matrix zeroing removed columns*/
900   if (aij->compressedrow.use) {
901     m    = aij->compressedrow.nrows;
902     ii   = aij->compressedrow.i;
903     ridx = aij->compressedrow.rindex;
904     for (i=0; i<m; i++) {
905       n  = ii[i+1] - ii[i];
906       aj = aij->j + ii[i];
907       aa = aij->a + ii[i];
908 
909       for (j=0; j<n; j++) {
910         if (PetscAbsScalar(mask[*aj])) {
911           if (b) bb[*ridx] -= *aa*xx[*aj];
912           *aa = 0.0;
913         }
914         aa++;
915         aj++;
916       }
917       ridx++;
918     }
919   } else { /* do not use compressed row format */
920     m = l->B->rmap->n;
921     for (i=0; i<m; i++) {
922       n  = ii[i+1] - ii[i];
923       aj = aij->j + ii[i];
924       aa = aij->a + ii[i];
925       for (j=0; j<n; j++) {
926         if (PetscAbsScalar(mask[*aj])) {
927           if (b) bb[i] -= *aa*xx[*aj];
928           *aa = 0.0;
929         }
930         aa++;
931         aj++;
932       }
933     }
934   }
935   if (x) {
936     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
937     ierr = VecRestoreArrayRead(l->lvec,&xx);CHKERRQ(ierr);
938   }
939   ierr = VecRestoreArray(lmask,&mask);CHKERRQ(ierr);
940   ierr = VecDestroy(&lmask);CHKERRQ(ierr);
941   ierr = PetscFree(lrows);CHKERRQ(ierr);
942 
943   /* only change matrix nonzero state if pattern was allowed to be changed */
944   if (!((Mat_SeqAIJ*)(l->A->data))->keepnonzeropattern) {
945     PetscObjectState state = l->A->nonzerostate + l->B->nonzerostate;
946     ierr = MPI_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
947   }
948   PetscFunctionReturn(0);
949 }
950 
951 #undef __FUNCT__
952 #define __FUNCT__ "MatMult_MPIAIJ"
953 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
954 {
955   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
956   PetscErrorCode ierr;
957   PetscInt       nt;
958 
959   PetscFunctionBegin;
960   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
961   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);
962   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
963   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
964   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
965   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
966   PetscFunctionReturn(0);
967 }
968 
969 #undef __FUNCT__
970 #define __FUNCT__ "MatMultDiagonalBlock_MPIAIJ"
971 PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A,Vec bb,Vec xx)
972 {
973   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
974   PetscErrorCode ierr;
975 
976   PetscFunctionBegin;
977   ierr = MatMultDiagonalBlock(a->A,bb,xx);CHKERRQ(ierr);
978   PetscFunctionReturn(0);
979 }
980 
981 #undef __FUNCT__
982 #define __FUNCT__ "MatMultAdd_MPIAIJ"
983 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
984 {
985   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
986   PetscErrorCode ierr;
987 
988   PetscFunctionBegin;
989   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
990   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
991   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
992   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
993   PetscFunctionReturn(0);
994 }
995 
996 #undef __FUNCT__
997 #define __FUNCT__ "MatMultTranspose_MPIAIJ"
998 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
999 {
1000   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1001   PetscErrorCode ierr;
1002   PetscBool      merged;
1003 
1004   PetscFunctionBegin;
1005   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
1006   /* do nondiagonal part */
1007   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1008   if (!merged) {
1009     /* send it on its way */
1010     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1011     /* do local part */
1012     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1013     /* receive remote parts: note this assumes the values are not actually */
1014     /* added in yy until the next line, */
1015     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1016   } else {
1017     /* do local part */
1018     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1019     /* send it on its way */
1020     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1021     /* values actually were received in the Begin() but we need to call this nop */
1022     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1023   }
1024   PetscFunctionReturn(0);
1025 }
1026 
1027 #undef __FUNCT__
1028 #define __FUNCT__ "MatIsTranspose_MPIAIJ"
1029 PetscErrorCode  MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscBool  *f)
1030 {
1031   MPI_Comm       comm;
1032   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ*) Amat->data, *Bij;
1033   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
1034   IS             Me,Notme;
1035   PetscErrorCode ierr;
1036   PetscInt       M,N,first,last,*notme,i;
1037   PetscMPIInt    size;
1038 
1039   PetscFunctionBegin;
1040   /* Easy test: symmetric diagonal block */
1041   Bij  = (Mat_MPIAIJ*) Bmat->data; Bdia = Bij->A;
1042   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
1043   if (!*f) PetscFunctionReturn(0);
1044   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1045   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1046   if (size == 1) PetscFunctionReturn(0);
1047 
1048   /* Hard test: off-diagonal block. This takes a MatGetSubMatrix. */
1049   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
1050   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
1051   ierr = PetscMalloc1((N-last+first),&notme);CHKERRQ(ierr);
1052   for (i=0; i<first; i++) notme[i] = i;
1053   for (i=last; i<M; i++) notme[i-last+first] = i;
1054   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,PETSC_COPY_VALUES,&Notme);CHKERRQ(ierr);
1055   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
1056   ierr = MatGetSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
1057   Aoff = Aoffs[0];
1058   ierr = MatGetSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
1059   Boff = Boffs[0];
1060   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
1061   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
1062   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
1063   ierr = ISDestroy(&Me);CHKERRQ(ierr);
1064   ierr = ISDestroy(&Notme);CHKERRQ(ierr);
1065   ierr = PetscFree(notme);CHKERRQ(ierr);
1066   PetscFunctionReturn(0);
1067 }
1068 
1069 #undef __FUNCT__
1070 #define __FUNCT__ "MatMultTransposeAdd_MPIAIJ"
1071 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1072 {
1073   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1074   PetscErrorCode ierr;
1075 
1076   PetscFunctionBegin;
1077   /* do nondiagonal part */
1078   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1079   /* send it on its way */
1080   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1081   /* do local part */
1082   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1083   /* receive remote parts */
1084   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1085   PetscFunctionReturn(0);
1086 }
1087 
1088 /*
1089   This only works correctly for square matrices where the subblock A->A is the
1090    diagonal block
1091 */
1092 #undef __FUNCT__
1093 #define __FUNCT__ "MatGetDiagonal_MPIAIJ"
1094 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
1095 {
1096   PetscErrorCode ierr;
1097   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1098 
1099   PetscFunctionBegin;
1100   if (A->rmap->N != A->cmap->N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
1101   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");
1102   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1103   PetscFunctionReturn(0);
1104 }
1105 
1106 #undef __FUNCT__
1107 #define __FUNCT__ "MatScale_MPIAIJ"
1108 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
1109 {
1110   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1111   PetscErrorCode ierr;
1112 
1113   PetscFunctionBegin;
1114   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
1115   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
1116   PetscFunctionReturn(0);
1117 }
1118 
1119 #undef __FUNCT__
1120 #define __FUNCT__ "MatDestroy_Redundant"
1121 PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1122 {
1123   PetscErrorCode ierr;
1124   Mat_Redundant  *redund = *redundant;
1125   PetscInt       i;
1126 
1127   PetscFunctionBegin;
1128   *redundant = NULL;
1129   if (redund){
1130     if (redund->matseq) { /* via MatGetSubMatrices()  */
1131       ierr = ISDestroy(&redund->isrow);CHKERRQ(ierr);
1132       ierr = ISDestroy(&redund->iscol);CHKERRQ(ierr);
1133       ierr = MatDestroy(&redund->matseq[0]);CHKERRQ(ierr);
1134       ierr = PetscFree(redund->matseq);CHKERRQ(ierr);
1135     } else {
1136       ierr = PetscFree2(redund->send_rank,redund->recv_rank);CHKERRQ(ierr);
1137       ierr = PetscFree(redund->sbuf_j);CHKERRQ(ierr);
1138       ierr = PetscFree(redund->sbuf_a);CHKERRQ(ierr);
1139       for (i=0; i<redund->nrecvs; i++) {
1140         ierr = PetscFree(redund->rbuf_j[i]);CHKERRQ(ierr);
1141         ierr = PetscFree(redund->rbuf_a[i]);CHKERRQ(ierr);
1142       }
1143       ierr = PetscFree4(redund->sbuf_nz,redund->rbuf_nz,redund->rbuf_j,redund->rbuf_a);CHKERRQ(ierr);
1144     }
1145 
1146     if (redund->psubcomm) {
1147       ierr = PetscSubcommDestroy(&redund->psubcomm);CHKERRQ(ierr);
1148     }
1149     ierr = PetscFree(redund);CHKERRQ(ierr);
1150   }
1151   PetscFunctionReturn(0);
1152 }
1153 
1154 #undef __FUNCT__
1155 #define __FUNCT__ "MatDestroy_MPIAIJ"
1156 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
1157 {
1158   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1159   PetscErrorCode ierr;
1160 
1161   PetscFunctionBegin;
1162 #if defined(PETSC_USE_LOG)
1163   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
1164 #endif
1165   ierr = MatDestroy_Redundant(&mat->redundant);CHKERRQ(ierr);
1166   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
1167   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
1168   ierr = MatDestroy(&aij->A);CHKERRQ(ierr);
1169   ierr = MatDestroy(&aij->B);CHKERRQ(ierr);
1170 #if defined(PETSC_USE_CTABLE)
1171   ierr = PetscTableDestroy(&aij->colmap);CHKERRQ(ierr);
1172 #else
1173   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
1174 #endif
1175   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
1176   ierr = VecDestroy(&aij->lvec);CHKERRQ(ierr);
1177   ierr = VecScatterDestroy(&aij->Mvctx);CHKERRQ(ierr);
1178   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
1179   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
1180   ierr = PetscFree(mat->data);CHKERRQ(ierr);
1181 
1182   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
1183   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C",NULL);CHKERRQ(ierr);
1184   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C",NULL);CHKERRQ(ierr);
1185   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatGetDiagonalBlock_C",NULL);CHKERRQ(ierr);
1186   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C",NULL);CHKERRQ(ierr);
1187   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C",NULL);CHKERRQ(ierr);
1188   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C",NULL);CHKERRQ(ierr);
1189   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C",NULL);CHKERRQ(ierr);
1190   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_mpisbaij_C",NULL);CHKERRQ(ierr);
1191 #if defined(PETSC_HAVE_ELEMENTAL)
1192   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_elemental_C",NULL);CHKERRQ(ierr);
1193 #endif
1194   PetscFunctionReturn(0);
1195 }
1196 
1197 #undef __FUNCT__
1198 #define __FUNCT__ "MatView_MPIAIJ_Binary"
1199 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
1200 {
1201   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1202   Mat_SeqAIJ     *A   = (Mat_SeqAIJ*)aij->A->data;
1203   Mat_SeqAIJ     *B   = (Mat_SeqAIJ*)aij->B->data;
1204   PetscErrorCode ierr;
1205   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
1206   int            fd;
1207   PetscInt       nz,header[4],*row_lengths,*range=0,rlen,i;
1208   PetscInt       nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz = 0;
1209   PetscScalar    *column_values;
1210   PetscInt       message_count,flowcontrolcount;
1211   FILE           *file;
1212 
1213   PetscFunctionBegin;
1214   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1215   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
1216   nz   = A->nz + B->nz;
1217   if (!rank) {
1218     header[0] = MAT_FILE_CLASSID;
1219     header[1] = mat->rmap->N;
1220     header[2] = mat->cmap->N;
1221 
1222     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1223     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
1224     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1225     /* get largest number of rows any processor has */
1226     rlen  = mat->rmap->n;
1227     range = mat->rmap->range;
1228     for (i=1; i<size; i++) rlen = PetscMax(rlen,range[i+1] - range[i]);
1229   } else {
1230     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1231     rlen = mat->rmap->n;
1232   }
1233 
1234   /* load up the local row counts */
1235   ierr = PetscMalloc1((rlen+1),&row_lengths);CHKERRQ(ierr);
1236   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];
1237 
1238   /* store the row lengths to the file */
1239   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1240   if (!rank) {
1241     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1242     for (i=1; i<size; i++) {
1243       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1244       rlen = range[i+1] - range[i];
1245       ierr = MPIULong_Recv(row_lengths,rlen,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1246       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1247     }
1248     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1249   } else {
1250     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1251     ierr = MPIULong_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1252     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1253   }
1254   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
1255 
1256   /* load up the local column indices */
1257   nzmax = nz; /* th processor needs space a largest processor needs */
1258   ierr  = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1259   ierr  = PetscMalloc1((nzmax+1),&column_indices);CHKERRQ(ierr);
1260   cnt   = 0;
1261   for (i=0; i<mat->rmap->n; i++) {
1262     for (j=B->i[i]; j<B->i[i+1]; j++) {
1263       if ((col = garray[B->j[j]]) > cstart) break;
1264       column_indices[cnt++] = col;
1265     }
1266     for (k=A->i[i]; k<A->i[i+1]; k++) column_indices[cnt++] = A->j[k] + cstart;
1267     for (; j<B->i[i+1]; j++) column_indices[cnt++] = garray[B->j[j]];
1268   }
1269   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);
1270 
1271   /* store the column indices to the file */
1272   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1273   if (!rank) {
1274     MPI_Status status;
1275     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1276     for (i=1; i<size; i++) {
1277       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1278       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1279       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1280       ierr = MPIULong_Recv(column_indices,rnz,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1281       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1282     }
1283     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1284   } else {
1285     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1286     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1287     ierr = MPIULong_Send(column_indices,nz,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1288     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1289   }
1290   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1291 
1292   /* load up the local column values */
1293   ierr = PetscMalloc1((nzmax+1),&column_values);CHKERRQ(ierr);
1294   cnt  = 0;
1295   for (i=0; i<mat->rmap->n; i++) {
1296     for (j=B->i[i]; j<B->i[i+1]; j++) {
1297       if (garray[B->j[j]] > cstart) break;
1298       column_values[cnt++] = B->a[j];
1299     }
1300     for (k=A->i[i]; k<A->i[i+1]; k++) column_values[cnt++] = A->a[k];
1301     for (; j<B->i[i+1]; j++) column_values[cnt++] = B->a[j];
1302   }
1303   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);
1304 
1305   /* store the column values to the file */
1306   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1307   if (!rank) {
1308     MPI_Status status;
1309     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1310     for (i=1; i<size; i++) {
1311       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1312       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1313       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1314       ierr = MPIULong_Recv(column_values,rnz,MPIU_SCALAR,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1315       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1316     }
1317     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1318   } else {
1319     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1320     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1321     ierr = MPIULong_Send(column_values,nz,MPIU_SCALAR,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1322     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1323   }
1324   ierr = PetscFree(column_values);CHKERRQ(ierr);
1325 
1326   ierr = PetscViewerBinaryGetInfoPointer(viewer,&file);CHKERRQ(ierr);
1327   if (file) fprintf(file,"-matload_block_size %d\n",(int)PetscAbs(mat->rmap->bs));
1328   PetscFunctionReturn(0);
1329 }
1330 
1331 #include <petscdraw.h>
1332 #undef __FUNCT__
1333 #define __FUNCT__ "MatView_MPIAIJ_ASCIIorDraworSocket"
1334 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1335 {
1336   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1337   PetscErrorCode    ierr;
1338   PetscMPIInt       rank = aij->rank,size = aij->size;
1339   PetscBool         isdraw,iascii,isbinary;
1340   PetscViewer       sviewer;
1341   PetscViewerFormat format;
1342 
1343   PetscFunctionBegin;
1344   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1345   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1346   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1347   if (iascii) {
1348     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1349     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1350       MatInfo   info;
1351       PetscBool inodes;
1352 
1353       ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1354       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1355       ierr = MatInodeGetInodeSizes(aij->A,NULL,(PetscInt**)&inodes,NULL);CHKERRQ(ierr);
1356       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr);
1357       if (!inodes) {
1358         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1359                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1360       } else {
1361         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1362                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1363       }
1364       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1365       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1366       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1367       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1368       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1369       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr);
1370       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1371       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1372       PetscFunctionReturn(0);
1373     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1374       PetscInt inodecount,inodelimit,*inodes;
1375       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1376       if (inodes) {
1377         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1378       } else {
1379         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1380       }
1381       PetscFunctionReturn(0);
1382     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1383       PetscFunctionReturn(0);
1384     }
1385   } else if (isbinary) {
1386     if (size == 1) {
1387       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1388       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1389     } else {
1390       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1391     }
1392     PetscFunctionReturn(0);
1393   } else if (isdraw) {
1394     PetscDraw draw;
1395     PetscBool isnull;
1396     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1397     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1398   }
1399 
1400   {
1401     /* assemble the entire matrix onto first processor. */
1402     Mat        A;
1403     Mat_SeqAIJ *Aloc;
1404     PetscInt   M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1405     MatScalar  *a;
1406 
1407     ierr = MatCreate(PetscObjectComm((PetscObject)mat),&A);CHKERRQ(ierr);
1408     if (!rank) {
1409       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1410     } else {
1411       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1412     }
1413     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1414     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1415     ierr = MatMPIAIJSetPreallocation(A,0,NULL,0,NULL);CHKERRQ(ierr);
1416     ierr = MatSetOption(A,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
1417     ierr = PetscLogObjectParent((PetscObject)mat,(PetscObject)A);CHKERRQ(ierr);
1418 
1419     /* copy over the A part */
1420     Aloc = (Mat_SeqAIJ*)aij->A->data;
1421     m    = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1422     row  = mat->rmap->rstart;
1423     for (i=0; i<ai[m]; i++) aj[i] += mat->cmap->rstart;
1424     for (i=0; i<m; i++) {
1425       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1426       row++;
1427       a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1428     }
1429     aj = Aloc->j;
1430     for (i=0; i<ai[m]; i++) aj[i] -= mat->cmap->rstart;
1431 
1432     /* copy over the B part */
1433     Aloc = (Mat_SeqAIJ*)aij->B->data;
1434     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1435     row  = mat->rmap->rstart;
1436     ierr = PetscMalloc1((ai[m]+1),&cols);CHKERRQ(ierr);
1437     ct   = cols;
1438     for (i=0; i<ai[m]; i++) cols[i] = aij->garray[aj[i]];
1439     for (i=0; i<m; i++) {
1440       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1441       row++;
1442       a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1443     }
1444     ierr = PetscFree(ct);CHKERRQ(ierr);
1445     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1446     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1447     /*
1448        Everyone has to call to draw the matrix since the graphics waits are
1449        synchronized across all processors that share the PetscDraw object
1450     */
1451     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
1452     if (!rank) {
1453       ierr = MatView_SeqAIJ(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1454     }
1455     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
1456     ierr = MatDestroy(&A);CHKERRQ(ierr);
1457   }
1458   PetscFunctionReturn(0);
1459 }
1460 
1461 #undef __FUNCT__
1462 #define __FUNCT__ "MatView_MPIAIJ"
1463 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1464 {
1465   PetscErrorCode ierr;
1466   PetscBool      iascii,isdraw,issocket,isbinary;
1467 
1468   PetscFunctionBegin;
1469   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1470   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1471   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1472   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSOCKET,&issocket);CHKERRQ(ierr);
1473   if (iascii || isdraw || isbinary || issocket) {
1474     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1475   }
1476   PetscFunctionReturn(0);
1477 }
1478 
1479 #undef __FUNCT__
1480 #define __FUNCT__ "MatSOR_MPIAIJ"
1481 PetscErrorCode MatSOR_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1482 {
1483   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1484   PetscErrorCode ierr;
1485   Vec            bb1 = 0;
1486   PetscBool      hasop;
1487 
1488   PetscFunctionBegin;
1489   if (flag == SOR_APPLY_UPPER) {
1490     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1491     PetscFunctionReturn(0);
1492   }
1493 
1494   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) {
1495     ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1496   }
1497 
1498   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP) {
1499     if (flag & SOR_ZERO_INITIAL_GUESS) {
1500       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1501       its--;
1502     }
1503 
1504     while (its--) {
1505       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1506       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1507 
1508       /* update rhs: bb1 = bb - B*x */
1509       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1510       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1511 
1512       /* local sweep */
1513       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1514     }
1515   } else if (flag & SOR_LOCAL_FORWARD_SWEEP) {
1516     if (flag & SOR_ZERO_INITIAL_GUESS) {
1517       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1518       its--;
1519     }
1520     while (its--) {
1521       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1522       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1523 
1524       /* update rhs: bb1 = bb - B*x */
1525       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1526       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1527 
1528       /* local sweep */
1529       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1530     }
1531   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP) {
1532     if (flag & SOR_ZERO_INITIAL_GUESS) {
1533       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1534       its--;
1535     }
1536     while (its--) {
1537       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1538       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1539 
1540       /* update rhs: bb1 = bb - B*x */
1541       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1542       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1543 
1544       /* local sweep */
1545       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1546     }
1547   } else if (flag & SOR_EISENSTAT) {
1548     Vec xx1;
1549 
1550     ierr = VecDuplicate(bb,&xx1);CHKERRQ(ierr);
1551     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP),fshift,lits,1,xx);CHKERRQ(ierr);
1552 
1553     ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1554     ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1555     if (!mat->diag) {
1556       ierr = MatCreateVecs(matin,&mat->diag,NULL);CHKERRQ(ierr);
1557       ierr = MatGetDiagonal(matin,mat->diag);CHKERRQ(ierr);
1558     }
1559     ierr = MatHasOperation(matin,MATOP_MULT_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr);
1560     if (hasop) {
1561       ierr = MatMultDiagonalBlock(matin,xx,bb1);CHKERRQ(ierr);
1562     } else {
1563       ierr = VecPointwiseMult(bb1,mat->diag,xx);CHKERRQ(ierr);
1564     }
1565     ierr = VecAYPX(bb1,(omega-2.0)/omega,bb);CHKERRQ(ierr);
1566 
1567     ierr = MatMultAdd(mat->B,mat->lvec,bb1,bb1);CHKERRQ(ierr);
1568 
1569     /* local sweep */
1570     ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP),fshift,lits,1,xx1);CHKERRQ(ierr);
1571     ierr = VecAXPY(xx,1.0,xx1);CHKERRQ(ierr);
1572     ierr = VecDestroy(&xx1);CHKERRQ(ierr);
1573   } else SETERRQ(PetscObjectComm((PetscObject)matin),PETSC_ERR_SUP,"Parallel SOR not supported");
1574 
1575   ierr = VecDestroy(&bb1);CHKERRQ(ierr);
1576   PetscFunctionReturn(0);
1577 }
1578 
1579 #undef __FUNCT__
1580 #define __FUNCT__ "MatPermute_MPIAIJ"
1581 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1582 {
1583   Mat            aA,aB,Aperm;
1584   const PetscInt *rwant,*cwant,*gcols,*ai,*bi,*aj,*bj;
1585   PetscScalar    *aa,*ba;
1586   PetscInt       i,j,m,n,ng,anz,bnz,*dnnz,*onnz,*tdnnz,*tonnz,*rdest,*cdest,*work,*gcdest;
1587   PetscSF        rowsf,sf;
1588   IS             parcolp = NULL;
1589   PetscBool      done;
1590   PetscErrorCode ierr;
1591 
1592   PetscFunctionBegin;
1593   ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr);
1594   ierr = ISGetIndices(rowp,&rwant);CHKERRQ(ierr);
1595   ierr = ISGetIndices(colp,&cwant);CHKERRQ(ierr);
1596   ierr = PetscMalloc3(PetscMax(m,n),&work,m,&rdest,n,&cdest);CHKERRQ(ierr);
1597 
1598   /* Invert row permutation to find out where my rows should go */
1599   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&rowsf);CHKERRQ(ierr);
1600   ierr = PetscSFSetGraphLayout(rowsf,A->rmap,A->rmap->n,NULL,PETSC_OWN_POINTER,rwant);CHKERRQ(ierr);
1601   ierr = PetscSFSetFromOptions(rowsf);CHKERRQ(ierr);
1602   for (i=0; i<m; i++) work[i] = A->rmap->rstart + i;
1603   ierr = PetscSFReduceBegin(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1604   ierr = PetscSFReduceEnd(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1605 
1606   /* Invert column permutation to find out where my columns should go */
1607   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1608   ierr = PetscSFSetGraphLayout(sf,A->cmap,A->cmap->n,NULL,PETSC_OWN_POINTER,cwant);CHKERRQ(ierr);
1609   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1610   for (i=0; i<n; i++) work[i] = A->cmap->rstart + i;
1611   ierr = PetscSFReduceBegin(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1612   ierr = PetscSFReduceEnd(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1613   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1614 
1615   ierr = ISRestoreIndices(rowp,&rwant);CHKERRQ(ierr);
1616   ierr = ISRestoreIndices(colp,&cwant);CHKERRQ(ierr);
1617   ierr = MatMPIAIJGetSeqAIJ(A,&aA,&aB,&gcols);CHKERRQ(ierr);
1618 
1619   /* Find out where my gcols should go */
1620   ierr = MatGetSize(aB,NULL,&ng);CHKERRQ(ierr);
1621   ierr = PetscMalloc1(ng,&gcdest);CHKERRQ(ierr);
1622   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1623   ierr = PetscSFSetGraphLayout(sf,A->cmap,ng,NULL,PETSC_OWN_POINTER,gcols);CHKERRQ(ierr);
1624   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1625   ierr = PetscSFBcastBegin(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1626   ierr = PetscSFBcastEnd(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1627   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1628 
1629   ierr = PetscCalloc4(m,&dnnz,m,&onnz,m,&tdnnz,m,&tonnz);CHKERRQ(ierr);
1630   ierr = MatGetRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1631   ierr = MatGetRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1632   for (i=0; i<m; i++) {
1633     PetscInt row = rdest[i],rowner;
1634     ierr = PetscLayoutFindOwner(A->rmap,row,&rowner);CHKERRQ(ierr);
1635     for (j=ai[i]; j<ai[i+1]; j++) {
1636       PetscInt cowner,col = cdest[aj[j]];
1637       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr); /* Could build an index for the columns to eliminate this search */
1638       if (rowner == cowner) dnnz[i]++;
1639       else onnz[i]++;
1640     }
1641     for (j=bi[i]; j<bi[i+1]; j++) {
1642       PetscInt cowner,col = gcdest[bj[j]];
1643       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr);
1644       if (rowner == cowner) dnnz[i]++;
1645       else onnz[i]++;
1646     }
1647   }
1648   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1649   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1650   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1651   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1652   ierr = PetscSFDestroy(&rowsf);CHKERRQ(ierr);
1653 
1654   ierr = MatCreateAIJ(PetscObjectComm((PetscObject)A),A->rmap->n,A->cmap->n,A->rmap->N,A->cmap->N,0,tdnnz,0,tonnz,&Aperm);CHKERRQ(ierr);
1655   ierr = MatSeqAIJGetArray(aA,&aa);CHKERRQ(ierr);
1656   ierr = MatSeqAIJGetArray(aB,&ba);CHKERRQ(ierr);
1657   for (i=0; i<m; i++) {
1658     PetscInt *acols = dnnz,*bcols = onnz; /* Repurpose now-unneeded arrays */
1659     PetscInt j0,rowlen;
1660     rowlen = ai[i+1] - ai[i];
1661     for (j0=j=0; j<rowlen; j0=j) { /* rowlen could be larger than number of rows m, so sum in batches */
1662       for ( ; j<PetscMin(rowlen,j0+m); j++) acols[j-j0] = cdest[aj[ai[i]+j]];
1663       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,acols,aa+ai[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1664     }
1665     rowlen = bi[i+1] - bi[i];
1666     for (j0=j=0; j<rowlen; j0=j) {
1667       for ( ; j<PetscMin(rowlen,j0+m); j++) bcols[j-j0] = gcdest[bj[bi[i]+j]];
1668       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,bcols,ba+bi[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1669     }
1670   }
1671   ierr = MatAssemblyBegin(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1672   ierr = MatAssemblyEnd(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1673   ierr = MatRestoreRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1674   ierr = MatRestoreRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1675   ierr = MatSeqAIJRestoreArray(aA,&aa);CHKERRQ(ierr);
1676   ierr = MatSeqAIJRestoreArray(aB,&ba);CHKERRQ(ierr);
1677   ierr = PetscFree4(dnnz,onnz,tdnnz,tonnz);CHKERRQ(ierr);
1678   ierr = PetscFree3(work,rdest,cdest);CHKERRQ(ierr);
1679   ierr = PetscFree(gcdest);CHKERRQ(ierr);
1680   if (parcolp) {ierr = ISDestroy(&colp);CHKERRQ(ierr);}
1681   *B = Aperm;
1682   PetscFunctionReturn(0);
1683 }
1684 
1685 #undef __FUNCT__
1686 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1687 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1688 {
1689   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1690   Mat            A    = mat->A,B = mat->B;
1691   PetscErrorCode ierr;
1692   PetscReal      isend[5],irecv[5];
1693 
1694   PetscFunctionBegin;
1695   info->block_size = 1.0;
1696   ierr             = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1697 
1698   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1699   isend[3] = info->memory;  isend[4] = info->mallocs;
1700 
1701   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1702 
1703   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1704   isend[3] += info->memory;  isend[4] += info->mallocs;
1705   if (flag == MAT_LOCAL) {
1706     info->nz_used      = isend[0];
1707     info->nz_allocated = isend[1];
1708     info->nz_unneeded  = isend[2];
1709     info->memory       = isend[3];
1710     info->mallocs      = isend[4];
1711   } else if (flag == MAT_GLOBAL_MAX) {
1712     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1713 
1714     info->nz_used      = irecv[0];
1715     info->nz_allocated = irecv[1];
1716     info->nz_unneeded  = irecv[2];
1717     info->memory       = irecv[3];
1718     info->mallocs      = irecv[4];
1719   } else if (flag == MAT_GLOBAL_SUM) {
1720     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1721 
1722     info->nz_used      = irecv[0];
1723     info->nz_allocated = irecv[1];
1724     info->nz_unneeded  = irecv[2];
1725     info->memory       = irecv[3];
1726     info->mallocs      = irecv[4];
1727   }
1728   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1729   info->fill_ratio_needed = 0;
1730   info->factor_mallocs    = 0;
1731   PetscFunctionReturn(0);
1732 }
1733 
1734 #undef __FUNCT__
1735 #define __FUNCT__ "MatSetOption_MPIAIJ"
1736 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscBool flg)
1737 {
1738   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1739   PetscErrorCode ierr;
1740 
1741   PetscFunctionBegin;
1742   switch (op) {
1743   case MAT_NEW_NONZERO_LOCATIONS:
1744   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1745   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1746   case MAT_KEEP_NONZERO_PATTERN:
1747   case MAT_NEW_NONZERO_LOCATION_ERR:
1748   case MAT_USE_INODES:
1749   case MAT_IGNORE_ZERO_ENTRIES:
1750     MatCheckPreallocated(A,1);
1751     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1752     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1753     break;
1754   case MAT_ROW_ORIENTED:
1755     a->roworiented = flg;
1756 
1757     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1758     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1759     break;
1760   case MAT_NEW_DIAGONALS:
1761     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1762     break;
1763   case MAT_IGNORE_OFF_PROC_ENTRIES:
1764     a->donotstash = flg;
1765     break;
1766   case MAT_SPD:
1767     A->spd_set = PETSC_TRUE;
1768     A->spd     = flg;
1769     if (flg) {
1770       A->symmetric                  = PETSC_TRUE;
1771       A->structurally_symmetric     = PETSC_TRUE;
1772       A->symmetric_set              = PETSC_TRUE;
1773       A->structurally_symmetric_set = PETSC_TRUE;
1774     }
1775     break;
1776   case MAT_SYMMETRIC:
1777     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1778     break;
1779   case MAT_STRUCTURALLY_SYMMETRIC:
1780     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1781     break;
1782   case MAT_HERMITIAN:
1783     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1784     break;
1785   case MAT_SYMMETRY_ETERNAL:
1786     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1787     break;
1788   default:
1789     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"unknown option %d",op);
1790   }
1791   PetscFunctionReturn(0);
1792 }
1793 
1794 #undef __FUNCT__
1795 #define __FUNCT__ "MatGetRow_MPIAIJ"
1796 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1797 {
1798   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1799   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1800   PetscErrorCode ierr;
1801   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1802   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1803   PetscInt       *cmap,*idx_p;
1804 
1805   PetscFunctionBegin;
1806   if (mat->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Already active");
1807   mat->getrowactive = PETSC_TRUE;
1808 
1809   if (!mat->rowvalues && (idx || v)) {
1810     /*
1811         allocate enough space to hold information from the longest row.
1812     */
1813     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1814     PetscInt   max = 1,tmp;
1815     for (i=0; i<matin->rmap->n; i++) {
1816       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1817       if (max < tmp) max = tmp;
1818     }
1819     ierr = PetscMalloc2(max,&mat->rowvalues,max,&mat->rowindices);CHKERRQ(ierr);
1820   }
1821 
1822   if (row < rstart || row >= rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only local rows");
1823   lrow = row - rstart;
1824 
1825   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1826   if (!v)   {pvA = 0; pvB = 0;}
1827   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1828   ierr  = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1829   ierr  = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1830   nztot = nzA + nzB;
1831 
1832   cmap = mat->garray;
1833   if (v  || idx) {
1834     if (nztot) {
1835       /* Sort by increasing column numbers, assuming A and B already sorted */
1836       PetscInt imark = -1;
1837       if (v) {
1838         *v = v_p = mat->rowvalues;
1839         for (i=0; i<nzB; i++) {
1840           if (cmap[cworkB[i]] < cstart) v_p[i] = vworkB[i];
1841           else break;
1842         }
1843         imark = i;
1844         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1845         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1846       }
1847       if (idx) {
1848         *idx = idx_p = mat->rowindices;
1849         if (imark > -1) {
1850           for (i=0; i<imark; i++) {
1851             idx_p[i] = cmap[cworkB[i]];
1852           }
1853         } else {
1854           for (i=0; i<nzB; i++) {
1855             if (cmap[cworkB[i]] < cstart) idx_p[i] = cmap[cworkB[i]];
1856             else break;
1857           }
1858           imark = i;
1859         }
1860         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1861         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1862       }
1863     } else {
1864       if (idx) *idx = 0;
1865       if (v)   *v   = 0;
1866     }
1867   }
1868   *nz  = nztot;
1869   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1870   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1871   PetscFunctionReturn(0);
1872 }
1873 
1874 #undef __FUNCT__
1875 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1876 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1877 {
1878   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1879 
1880   PetscFunctionBegin;
1881   if (!aij->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1882   aij->getrowactive = PETSC_FALSE;
1883   PetscFunctionReturn(0);
1884 }
1885 
1886 #undef __FUNCT__
1887 #define __FUNCT__ "MatNorm_MPIAIJ"
1888 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1889 {
1890   Mat_MPIAIJ     *aij  = (Mat_MPIAIJ*)mat->data;
1891   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1892   PetscErrorCode ierr;
1893   PetscInt       i,j,cstart = mat->cmap->rstart;
1894   PetscReal      sum = 0.0;
1895   MatScalar      *v;
1896 
1897   PetscFunctionBegin;
1898   if (aij->size == 1) {
1899     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1900   } else {
1901     if (type == NORM_FROBENIUS) {
1902       v = amat->a;
1903       for (i=0; i<amat->nz; i++) {
1904         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1905       }
1906       v = bmat->a;
1907       for (i=0; i<bmat->nz; i++) {
1908         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1909       }
1910       ierr  = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1911       *norm = PetscSqrtReal(*norm);
1912     } else if (type == NORM_1) { /* max column norm */
1913       PetscReal *tmp,*tmp2;
1914       PetscInt  *jj,*garray = aij->garray;
1915       ierr  = PetscCalloc1((mat->cmap->N+1),&tmp);CHKERRQ(ierr);
1916       ierr  = PetscMalloc1((mat->cmap->N+1),&tmp2);CHKERRQ(ierr);
1917       *norm = 0.0;
1918       v     = amat->a; jj = amat->j;
1919       for (j=0; j<amat->nz; j++) {
1920         tmp[cstart + *jj++] += PetscAbsScalar(*v);  v++;
1921       }
1922       v = bmat->a; jj = bmat->j;
1923       for (j=0; j<bmat->nz; j++) {
1924         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1925       }
1926       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1927       for (j=0; j<mat->cmap->N; j++) {
1928         if (tmp2[j] > *norm) *norm = tmp2[j];
1929       }
1930       ierr = PetscFree(tmp);CHKERRQ(ierr);
1931       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1932     } else if (type == NORM_INFINITY) { /* max row norm */
1933       PetscReal ntemp = 0.0;
1934       for (j=0; j<aij->A->rmap->n; j++) {
1935         v   = amat->a + amat->i[j];
1936         sum = 0.0;
1937         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1938           sum += PetscAbsScalar(*v); v++;
1939         }
1940         v = bmat->a + bmat->i[j];
1941         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1942           sum += PetscAbsScalar(*v); v++;
1943         }
1944         if (sum > ntemp) ntemp = sum;
1945       }
1946       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1947     } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"No support for two norm");
1948   }
1949   PetscFunctionReturn(0);
1950 }
1951 
1952 #undef __FUNCT__
1953 #define __FUNCT__ "MatTranspose_MPIAIJ"
1954 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
1955 {
1956   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1957   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
1958   PetscErrorCode ierr;
1959   PetscInt       M      = A->rmap->N,N = A->cmap->N,ma,na,mb,nb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i;
1960   PetscInt       cstart = A->cmap->rstart,ncol;
1961   Mat            B;
1962   MatScalar      *array;
1963 
1964   PetscFunctionBegin;
1965   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
1966 
1967   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n; nb = a->B->cmap->n;
1968   ai = Aloc->i; aj = Aloc->j;
1969   bi = Bloc->i; bj = Bloc->j;
1970   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1971     PetscInt             *d_nnz,*g_nnz,*o_nnz;
1972     PetscSFNode          *oloc;
1973     PETSC_UNUSED PetscSF sf;
1974 
1975     ierr = PetscMalloc4(na,&d_nnz,na,&o_nnz,nb,&g_nnz,nb,&oloc);CHKERRQ(ierr);
1976     /* compute d_nnz for preallocation */
1977     ierr = PetscMemzero(d_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1978     for (i=0; i<ai[ma]; i++) {
1979       d_nnz[aj[i]]++;
1980       aj[i] += cstart; /* global col index to be used by MatSetValues() */
1981     }
1982     /* compute local off-diagonal contributions */
1983     ierr = PetscMemzero(g_nnz,nb*sizeof(PetscInt));CHKERRQ(ierr);
1984     for (i=0; i<bi[ma]; i++) g_nnz[bj[i]]++;
1985     /* map those to global */
1986     ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1987     ierr = PetscSFSetGraphLayout(sf,A->cmap,nb,NULL,PETSC_USE_POINTER,a->garray);CHKERRQ(ierr);
1988     ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1989     ierr = PetscMemzero(o_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1990     ierr = PetscSFReduceBegin(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1991     ierr = PetscSFReduceEnd(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1992     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1993 
1994     ierr = MatCreate(PetscObjectComm((PetscObject)A),&B);CHKERRQ(ierr);
1995     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
1996     ierr = MatSetBlockSizes(B,PetscAbs(A->cmap->bs),PetscAbs(A->rmap->bs));CHKERRQ(ierr);
1997     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
1998     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
1999     ierr = PetscFree4(d_nnz,o_nnz,g_nnz,oloc);CHKERRQ(ierr);
2000   } else {
2001     B    = *matout;
2002     ierr = MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
2003     for (i=0; i<ai[ma]; i++) aj[i] += cstart; /* global col index to be used by MatSetValues() */
2004   }
2005 
2006   /* copy over the A part */
2007   array = Aloc->a;
2008   row   = A->rmap->rstart;
2009   for (i=0; i<ma; i++) {
2010     ncol = ai[i+1]-ai[i];
2011     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2012     row++;
2013     array += ncol; aj += ncol;
2014   }
2015   aj = Aloc->j;
2016   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
2017 
2018   /* copy over the B part */
2019   ierr  = PetscCalloc1(bi[mb],&cols);CHKERRQ(ierr);
2020   array = Bloc->a;
2021   row   = A->rmap->rstart;
2022   for (i=0; i<bi[mb]; i++) cols[i] = a->garray[bj[i]];
2023   cols_tmp = cols;
2024   for (i=0; i<mb; i++) {
2025     ncol = bi[i+1]-bi[i];
2026     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2027     row++;
2028     array += ncol; cols_tmp += ncol;
2029   }
2030   ierr = PetscFree(cols);CHKERRQ(ierr);
2031 
2032   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2033   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2034   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
2035     *matout = B;
2036   } else {
2037     ierr = MatHeaderMerge(A,B);CHKERRQ(ierr);
2038   }
2039   PetscFunctionReturn(0);
2040 }
2041 
2042 #undef __FUNCT__
2043 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
2044 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
2045 {
2046   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2047   Mat            a    = aij->A,b = aij->B;
2048   PetscErrorCode ierr;
2049   PetscInt       s1,s2,s3;
2050 
2051   PetscFunctionBegin;
2052   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
2053   if (rr) {
2054     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
2055     if (s1!=s3) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
2056     /* Overlap communication with computation. */
2057     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2058   }
2059   if (ll) {
2060     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
2061     if (s1!=s2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
2062     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
2063   }
2064   /* scale  the diagonal block */
2065   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
2066 
2067   if (rr) {
2068     /* Do a scatter end and then right scale the off-diagonal block */
2069     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2070     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
2071   }
2072   PetscFunctionReturn(0);
2073 }
2074 
2075 #undef __FUNCT__
2076 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
2077 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2078 {
2079   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2080   PetscErrorCode ierr;
2081 
2082   PetscFunctionBegin;
2083   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
2084   PetscFunctionReturn(0);
2085 }
2086 
2087 #undef __FUNCT__
2088 #define __FUNCT__ "MatEqual_MPIAIJ"
2089 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscBool  *flag)
2090 {
2091   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
2092   Mat            a,b,c,d;
2093   PetscBool      flg;
2094   PetscErrorCode ierr;
2095 
2096   PetscFunctionBegin;
2097   a = matA->A; b = matA->B;
2098   c = matB->A; d = matB->B;
2099 
2100   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
2101   if (flg) {
2102     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
2103   }
2104   ierr = MPI_Allreduce(&flg,flag,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
2105   PetscFunctionReturn(0);
2106 }
2107 
2108 #undef __FUNCT__
2109 #define __FUNCT__ "MatCopy_MPIAIJ"
2110 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
2111 {
2112   PetscErrorCode ierr;
2113   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2114   Mat_MPIAIJ     *b = (Mat_MPIAIJ*)B->data;
2115 
2116   PetscFunctionBegin;
2117   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2118   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2119     /* because of the column compression in the off-processor part of the matrix a->B,
2120        the number of columns in a->B and b->B may be different, hence we cannot call
2121        the MatCopy() directly on the two parts. If need be, we can provide a more
2122        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2123        then copying the submatrices */
2124     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
2125   } else {
2126     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
2127     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
2128   }
2129   PetscFunctionReturn(0);
2130 }
2131 
2132 #undef __FUNCT__
2133 #define __FUNCT__ "MatSetUp_MPIAIJ"
2134 PetscErrorCode MatSetUp_MPIAIJ(Mat A)
2135 {
2136   PetscErrorCode ierr;
2137 
2138   PetscFunctionBegin;
2139   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
2140   PetscFunctionReturn(0);
2141 }
2142 
2143 /*
2144    Computes the number of nonzeros per row needed for preallocation when X and Y
2145    have different nonzero structure.
2146 */
2147 #undef __FUNCT__
2148 #define __FUNCT__ "MatAXPYGetPreallocation_MPIX_private"
2149 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)
2150 {
2151   PetscInt       i,j,k,nzx,nzy;
2152 
2153   PetscFunctionBegin;
2154   /* Set the number of nonzeros in the new matrix */
2155   for (i=0; i<m; i++) {
2156     const PetscInt *xjj = xj+xi[i],*yjj = yj+yi[i];
2157     nzx = xi[i+1] - xi[i];
2158     nzy = yi[i+1] - yi[i];
2159     nnz[i] = 0;
2160     for (j=0,k=0; j<nzx; j++) {                   /* Point in X */
2161       for (; k<nzy && yltog[yjj[k]]<xltog[xjj[j]]; k++) nnz[i]++; /* Catch up to X */
2162       if (k<nzy && yltog[yjj[k]]==xltog[xjj[j]]) k++;             /* Skip duplicate */
2163       nnz[i]++;
2164     }
2165     for (; k<nzy; k++) nnz[i]++;
2166   }
2167   PetscFunctionReturn(0);
2168 }
2169 
2170 /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2171 #undef __FUNCT__
2172 #define __FUNCT__ "MatAXPYGetPreallocation_MPIAIJ"
2173 static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y,const PetscInt *yltog,Mat X,const PetscInt *xltog,PetscInt *nnz)
2174 {
2175   PetscErrorCode ierr;
2176   PetscInt       m = Y->rmap->N;
2177   Mat_SeqAIJ     *x = (Mat_SeqAIJ*)X->data;
2178   Mat_SeqAIJ     *y = (Mat_SeqAIJ*)Y->data;
2179 
2180   PetscFunctionBegin;
2181   ierr = MatAXPYGetPreallocation_MPIX_private(m,x->i,x->j,xltog,y->i,y->j,yltog,nnz);CHKERRQ(ierr);
2182   PetscFunctionReturn(0);
2183 }
2184 
2185 #undef __FUNCT__
2186 #define __FUNCT__ "MatAXPY_MPIAIJ"
2187 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
2188 {
2189   PetscErrorCode ierr;
2190   PetscInt       i;
2191   Mat_MPIAIJ     *xx = (Mat_MPIAIJ*)X->data,*yy = (Mat_MPIAIJ*)Y->data;
2192   PetscBLASInt   bnz,one=1;
2193   Mat_SeqAIJ     *x,*y;
2194 
2195   PetscFunctionBegin;
2196   if (str == SAME_NONZERO_PATTERN) {
2197     PetscScalar alpha = a;
2198     x    = (Mat_SeqAIJ*)xx->A->data;
2199     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2200     y    = (Mat_SeqAIJ*)yy->A->data;
2201     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2202     x    = (Mat_SeqAIJ*)xx->B->data;
2203     y    = (Mat_SeqAIJ*)yy->B->data;
2204     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2205     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2206     ierr = PetscObjectStateIncrease((PetscObject)Y);CHKERRQ(ierr);
2207   } else if (str == SUBSET_NONZERO_PATTERN) {
2208     ierr = MatAXPY_SeqAIJ(yy->A,a,xx->A,str);CHKERRQ(ierr);
2209 
2210     x = (Mat_SeqAIJ*)xx->B->data;
2211     y = (Mat_SeqAIJ*)yy->B->data;
2212     if (y->xtoy && y->XtoY != xx->B) {
2213       ierr = PetscFree(y->xtoy);CHKERRQ(ierr);
2214       ierr = MatDestroy(&y->XtoY);CHKERRQ(ierr);
2215     }
2216     if (!y->xtoy) { /* get xtoy */
2217       ierr    = MatAXPYGetxtoy_Private(xx->B->rmap->n,x->i,x->j,xx->garray,y->i,y->j,yy->garray,&y->xtoy);CHKERRQ(ierr);
2218       y->XtoY = xx->B;
2219       ierr    = PetscObjectReference((PetscObject)xx->B);CHKERRQ(ierr);
2220     }
2221     for (i=0; i<x->nz; i++) y->a[y->xtoy[i]] += a*(x->a[i]);
2222     ierr = PetscObjectStateIncrease((PetscObject)Y);CHKERRQ(ierr);
2223   } else {
2224     Mat      B;
2225     PetscInt *nnz_d,*nnz_o;
2226     ierr = PetscMalloc1(yy->A->rmap->N,&nnz_d);CHKERRQ(ierr);
2227     ierr = PetscMalloc1(yy->B->rmap->N,&nnz_o);CHKERRQ(ierr);
2228     ierr = MatCreate(PetscObjectComm((PetscObject)Y),&B);CHKERRQ(ierr);
2229     ierr = PetscObjectSetName((PetscObject)B,((PetscObject)Y)->name);CHKERRQ(ierr);
2230     ierr = MatSetSizes(B,Y->rmap->n,Y->cmap->n,Y->rmap->N,Y->cmap->N);CHKERRQ(ierr);
2231     ierr = MatSetBlockSizesFromMats(B,Y,Y);CHKERRQ(ierr);
2232     ierr = MatSetType(B,MATMPIAIJ);CHKERRQ(ierr);
2233     ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr);
2234     ierr = MatAXPYGetPreallocation_MPIAIJ(yy->B,yy->garray,xx->B,xx->garray,nnz_o);CHKERRQ(ierr);
2235     ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr);
2236     ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);
2237     ierr = MatHeaderReplace(Y,B);CHKERRQ(ierr);
2238     ierr = PetscFree(nnz_d);CHKERRQ(ierr);
2239     ierr = PetscFree(nnz_o);CHKERRQ(ierr);
2240   }
2241   PetscFunctionReturn(0);
2242 }
2243 
2244 extern PetscErrorCode  MatConjugate_SeqAIJ(Mat);
2245 
2246 #undef __FUNCT__
2247 #define __FUNCT__ "MatConjugate_MPIAIJ"
2248 PetscErrorCode  MatConjugate_MPIAIJ(Mat mat)
2249 {
2250 #if defined(PETSC_USE_COMPLEX)
2251   PetscErrorCode ierr;
2252   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2253 
2254   PetscFunctionBegin;
2255   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
2256   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
2257 #else
2258   PetscFunctionBegin;
2259 #endif
2260   PetscFunctionReturn(0);
2261 }
2262 
2263 #undef __FUNCT__
2264 #define __FUNCT__ "MatRealPart_MPIAIJ"
2265 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2266 {
2267   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2268   PetscErrorCode ierr;
2269 
2270   PetscFunctionBegin;
2271   ierr = MatRealPart(a->A);CHKERRQ(ierr);
2272   ierr = MatRealPart(a->B);CHKERRQ(ierr);
2273   PetscFunctionReturn(0);
2274 }
2275 
2276 #undef __FUNCT__
2277 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
2278 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2279 {
2280   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2281   PetscErrorCode ierr;
2282 
2283   PetscFunctionBegin;
2284   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
2285   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
2286   PetscFunctionReturn(0);
2287 }
2288 
2289 #if defined(PETSC_HAVE_PBGL)
2290 
2291 #include <boost/parallel/mpi/bsp_process_group.hpp>
2292 #include <boost/graph/distributed/ilu_default_graph.hpp>
2293 #include <boost/graph/distributed/ilu_0_block.hpp>
2294 #include <boost/graph/distributed/ilu_preconditioner.hpp>
2295 #include <boost/graph/distributed/petsc/interface.hpp>
2296 #include <boost/multi_array.hpp>
2297 #include <boost/parallel/distributed_property_map->hpp>
2298 
2299 #undef __FUNCT__
2300 #define __FUNCT__ "MatILUFactorSymbolic_MPIAIJ"
2301 /*
2302   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2303 */
2304 PetscErrorCode MatILUFactorSymbolic_MPIAIJ(Mat fact,Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
2305 {
2306   namespace petsc = boost::distributed::petsc;
2307 
2308   namespace graph_dist = boost::graph::distributed;
2309   using boost::graph::distributed::ilu_default::process_group_type;
2310   using boost::graph::ilu_permuted;
2311 
2312   PetscBool      row_identity, col_identity;
2313   PetscContainer c;
2314   PetscInt       m, n, M, N;
2315   PetscErrorCode ierr;
2316 
2317   PetscFunctionBegin;
2318   if (info->levels != 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only levels = 0 supported for parallel ilu");
2319   ierr = ISIdentity(isrow, &row_identity);CHKERRQ(ierr);
2320   ierr = ISIdentity(iscol, &col_identity);CHKERRQ(ierr);
2321   if (!row_identity || !col_identity) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Row and column permutations must be identity for parallel ILU");
2322 
2323   process_group_type pg;
2324   typedef graph_dist::ilu_default::ilu_level_graph_type lgraph_type;
2325   lgraph_type  *lgraph_p   = new lgraph_type(petsc::num_global_vertices(A), pg, petsc::matrix_distribution(A, pg));
2326   lgraph_type& level_graph = *lgraph_p;
2327   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2328 
2329   petsc::read_matrix(A, graph, get(boost::edge_weight, graph));
2330   ilu_permuted(level_graph);
2331 
2332   /* put together the new matrix */
2333   ierr = MatCreate(PetscObjectComm((PetscObject)A), fact);CHKERRQ(ierr);
2334   ierr = MatGetLocalSize(A, &m, &n);CHKERRQ(ierr);
2335   ierr = MatGetSize(A, &M, &N);CHKERRQ(ierr);
2336   ierr = MatSetSizes(fact, m, n, M, N);CHKERRQ(ierr);
2337   ierr = MatSetBlockSizesFromMats(fact,A,A);CHKERRQ(ierr);
2338   ierr = MatSetType(fact, ((PetscObject)A)->type_name);CHKERRQ(ierr);
2339   ierr = MatAssemblyBegin(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2340   ierr = MatAssemblyEnd(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2341 
2342   ierr = PetscContainerCreate(PetscObjectComm((PetscObject)A), &c);
2343   ierr = PetscContainerSetPointer(c, lgraph_p);
2344   ierr = PetscObjectCompose((PetscObject) (fact), "graph", (PetscObject) c);
2345   ierr = PetscContainerDestroy(&c);
2346   PetscFunctionReturn(0);
2347 }
2348 
2349 #undef __FUNCT__
2350 #define __FUNCT__ "MatLUFactorNumeric_MPIAIJ"
2351 PetscErrorCode MatLUFactorNumeric_MPIAIJ(Mat B,Mat A, const MatFactorInfo *info)
2352 {
2353   PetscFunctionBegin;
2354   PetscFunctionReturn(0);
2355 }
2356 
2357 #undef __FUNCT__
2358 #define __FUNCT__ "MatSolve_MPIAIJ"
2359 /*
2360   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2361 */
2362 PetscErrorCode MatSolve_MPIAIJ(Mat A, Vec b, Vec x)
2363 {
2364   namespace graph_dist = boost::graph::distributed;
2365 
2366   typedef graph_dist::ilu_default::ilu_level_graph_type lgraph_type;
2367   lgraph_type    *lgraph_p;
2368   PetscContainer c;
2369   PetscErrorCode ierr;
2370 
2371   PetscFunctionBegin;
2372   ierr = PetscObjectQuery((PetscObject) A, "graph", (PetscObject*) &c);CHKERRQ(ierr);
2373   ierr = PetscContainerGetPointer(c, (void**) &lgraph_p);CHKERRQ(ierr);
2374   ierr = VecCopy(b, x);CHKERRQ(ierr);
2375 
2376   PetscScalar *array_x;
2377   ierr = VecGetArray(x, &array_x);CHKERRQ(ierr);
2378   PetscInt sx;
2379   ierr = VecGetSize(x, &sx);CHKERRQ(ierr);
2380 
2381   PetscScalar *array_b;
2382   ierr = VecGetArray(b, &array_b);CHKERRQ(ierr);
2383   PetscInt sb;
2384   ierr = VecGetSize(b, &sb);CHKERRQ(ierr);
2385 
2386   lgraph_type& level_graph = *lgraph_p;
2387   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2388 
2389   typedef boost::multi_array_ref<PetscScalar, 1> array_ref_type;
2390   array_ref_type                                 ref_b(array_b, boost::extents[num_vertices(graph)]);
2391   array_ref_type                                 ref_x(array_x, boost::extents[num_vertices(graph)]);
2392 
2393   typedef boost::iterator_property_map<array_ref_type::iterator,
2394                                        boost::property_map<graph_dist::ilu_default::graph_type, boost::vertex_index_t>::type>  gvector_type;
2395   gvector_type                                   vector_b(ref_b.begin(), get(boost::vertex_index, graph));
2396   gvector_type                                   vector_x(ref_x.begin(), get(boost::vertex_index, graph));
2397 
2398   ilu_set_solve(*lgraph_p, vector_b, vector_x);
2399   PetscFunctionReturn(0);
2400 }
2401 #endif
2402 
2403 
2404 #undef __FUNCT__
2405 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ_interlaced"
2406 PetscErrorCode MatGetRedundantMatrix_MPIAIJ_interlaced(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,MatReuse reuse,Mat *matredundant)
2407 {
2408   PetscMPIInt    rank,size;
2409   MPI_Comm       comm;
2410   PetscErrorCode ierr;
2411   PetscInt       nsends=0,nrecvs=0,i,rownz_max=0,M=mat->rmap->N,N=mat->cmap->N;
2412   PetscMPIInt    *send_rank= NULL,*recv_rank=NULL,subrank,subsize;
2413   PetscInt       *rowrange = mat->rmap->range;
2414   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2415   Mat            A = aij->A,B=aij->B,C=*matredundant;
2416   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data;
2417   PetscScalar    *sbuf_a;
2418   PetscInt       nzlocal=a->nz+b->nz;
2419   PetscInt       j,cstart=mat->cmap->rstart,cend=mat->cmap->rend,row,nzA,nzB,ncols,*cworkA,*cworkB;
2420   PetscInt       rstart=mat->rmap->rstart,rend=mat->rmap->rend,*bmap=aij->garray;
2421   PetscInt       *cols,ctmp,lwrite,*rptr,l,*sbuf_j;
2422   MatScalar      *aworkA,*aworkB;
2423   PetscScalar    *vals;
2424   PetscMPIInt    tag1,tag2,tag3,imdex;
2425   MPI_Request    *s_waits1=NULL,*s_waits2=NULL,*s_waits3=NULL;
2426   MPI_Request    *r_waits1=NULL,*r_waits2=NULL,*r_waits3=NULL;
2427   MPI_Status     recv_status,*send_status;
2428   PetscInt       *sbuf_nz=NULL,*rbuf_nz=NULL,count;
2429   PetscInt       **rbuf_j=NULL;
2430   PetscScalar    **rbuf_a=NULL;
2431   Mat_Redundant  *redund =NULL;
2432 
2433   PetscFunctionBegin;
2434   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
2435   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2436   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2437   ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
2438   ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2439 
2440   if (reuse == MAT_REUSE_MATRIX) {
2441     if (M != mat->rmap->N || N != mat->cmap->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong global size");
2442 
2443     redund = C->redundant;
2444     if (nzlocal != redund->nzlocal) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong nzlocal");
2445 
2446     nsends    = redund->nsends;
2447     nrecvs    = redund->nrecvs;
2448     send_rank = redund->send_rank;
2449     recv_rank = redund->recv_rank;
2450     sbuf_nz   = redund->sbuf_nz;
2451     rbuf_nz   = redund->rbuf_nz;
2452     sbuf_j    = redund->sbuf_j;
2453     sbuf_a    = redund->sbuf_a;
2454     rbuf_j    = redund->rbuf_j;
2455     rbuf_a    = redund->rbuf_a;
2456   }
2457 
2458   if (reuse == MAT_INITIAL_MATRIX) {
2459     PetscInt    nleftover,np_subcomm;
2460 
2461     /* get the destination processors' id send_rank, nsends and nrecvs */
2462     ierr = PetscMalloc2(size,&send_rank,size,&recv_rank);CHKERRQ(ierr);
2463 
2464     np_subcomm = size/nsubcomm;
2465     nleftover  = size - nsubcomm*np_subcomm;
2466 
2467     /* block of codes below is specific for INTERLACED */
2468     /* ------------------------------------------------*/
2469     nsends = 0; nrecvs = 0;
2470     for (i=0; i<size; i++) {
2471       if (subrank == i/nsubcomm && i != rank) { /* my_subrank == other's subrank */
2472         send_rank[nsends++] = i;
2473         recv_rank[nrecvs++] = i;
2474       }
2475     }
2476     if (rank >= size - nleftover) { /* this proc is a leftover processor */
2477       i = size-nleftover-1;
2478       j = 0;
2479       while (j < nsubcomm - nleftover) {
2480         send_rank[nsends++] = i;
2481         i--; j++;
2482       }
2483     }
2484 
2485     if (nleftover && subsize == size/nsubcomm && subrank==subsize-1) { /* this proc recvs from leftover processors */
2486       for (i=0; i<nleftover; i++) {
2487         recv_rank[nrecvs++] = size-nleftover+i;
2488       }
2489     }
2490     /*----------------------------------------------*/
2491 
2492     /* allocate sbuf_j, sbuf_a */
2493     i    = nzlocal + rowrange[rank+1] - rowrange[rank] + 2;
2494     ierr = PetscMalloc1(i,&sbuf_j);CHKERRQ(ierr);
2495     ierr = PetscMalloc1((nzlocal+1),&sbuf_a);CHKERRQ(ierr);
2496     /*
2497     ierr = PetscSynchronizedPrintf(comm,"[%d] nsends %d, nrecvs %d\n",rank,nsends,nrecvs);CHKERRQ(ierr);
2498     ierr = PetscSynchronizedFlush(comm,PETSC_STDOUT);CHKERRQ(ierr);
2499      */
2500   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2501 
2502   /* copy mat's local entries into the buffers */
2503   if (reuse == MAT_INITIAL_MATRIX) {
2504     rownz_max = 0;
2505     rptr      = sbuf_j;
2506     cols      = sbuf_j + rend-rstart + 1;
2507     vals      = sbuf_a;
2508     rptr[0]   = 0;
2509     for (i=0; i<rend-rstart; i++) {
2510       row    = i + rstart;
2511       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2512       ncols  = nzA + nzB;
2513       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2514       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2515       /* load the column indices for this row into cols */
2516       lwrite = 0;
2517       for (l=0; l<nzB; l++) {
2518         if ((ctmp = bmap[cworkB[l]]) < cstart) {
2519           vals[lwrite]   = aworkB[l];
2520           cols[lwrite++] = ctmp;
2521         }
2522       }
2523       for (l=0; l<nzA; l++) {
2524         vals[lwrite]   = aworkA[l];
2525         cols[lwrite++] = cstart + cworkA[l];
2526       }
2527       for (l=0; l<nzB; l++) {
2528         if ((ctmp = bmap[cworkB[l]]) >= cend) {
2529           vals[lwrite]   = aworkB[l];
2530           cols[lwrite++] = ctmp;
2531         }
2532       }
2533       vals     += ncols;
2534       cols     += ncols;
2535       rptr[i+1] = rptr[i] + ncols;
2536       if (rownz_max < ncols) rownz_max = ncols;
2537     }
2538     if (rptr[rend-rstart] != a->nz + b->nz) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB, "rptr[%d] %d != %d + %d",rend-rstart,rptr[rend-rstart+1],a->nz,b->nz);
2539   } else { /* only copy matrix values into sbuf_a */
2540     rptr    = sbuf_j;
2541     vals    = sbuf_a;
2542     rptr[0] = 0;
2543     for (i=0; i<rend-rstart; i++) {
2544       row    = i + rstart;
2545       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2546       ncols  = nzA + nzB;
2547       cworkB = b->j + b->i[i];
2548       aworkA = a->a + a->i[i];
2549       aworkB = b->a + b->i[i];
2550       lwrite = 0;
2551       for (l=0; l<nzB; l++) {
2552         if ((ctmp = bmap[cworkB[l]]) < cstart) vals[lwrite++] = aworkB[l];
2553       }
2554       for (l=0; l<nzA; l++) vals[lwrite++] = aworkA[l];
2555       for (l=0; l<nzB; l++) {
2556         if ((ctmp = bmap[cworkB[l]]) >= cend) vals[lwrite++] = aworkB[l];
2557       }
2558       vals     += ncols;
2559       rptr[i+1] = rptr[i] + ncols;
2560     }
2561   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2562 
2563   /* send nzlocal to others, and recv other's nzlocal */
2564   /*--------------------------------------------------*/
2565   if (reuse == MAT_INITIAL_MATRIX) {
2566     ierr = PetscMalloc2(3*(nsends + nrecvs)+1,&s_waits3,nsends+1,&send_status);CHKERRQ(ierr);
2567 
2568     s_waits2 = s_waits3 + nsends;
2569     s_waits1 = s_waits2 + nsends;
2570     r_waits1 = s_waits1 + nsends;
2571     r_waits2 = r_waits1 + nrecvs;
2572     r_waits3 = r_waits2 + nrecvs;
2573   } else {
2574     ierr = PetscMalloc2(nsends + nrecvs +1,&s_waits3,nsends+1,&send_status);CHKERRQ(ierr);
2575 
2576     r_waits3 = s_waits3 + nsends;
2577   }
2578 
2579   ierr = PetscObjectGetNewTag((PetscObject)mat,&tag3);CHKERRQ(ierr);
2580   if (reuse == MAT_INITIAL_MATRIX) {
2581     /* get new tags to keep the communication clean */
2582     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag1);CHKERRQ(ierr);
2583     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag2);CHKERRQ(ierr);
2584     ierr = PetscMalloc4(nsends,&sbuf_nz,nrecvs,&rbuf_nz,nrecvs,&rbuf_j,nrecvs,&rbuf_a);CHKERRQ(ierr);
2585 
2586     /* post receives of other's nzlocal */
2587     for (i=0; i<nrecvs; i++) {
2588       ierr = MPI_Irecv(rbuf_nz+i,1,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,r_waits1+i);CHKERRQ(ierr);
2589     }
2590     /* send nzlocal to others */
2591     for (i=0; i<nsends; i++) {
2592       sbuf_nz[i] = nzlocal;
2593       ierr       = MPI_Isend(sbuf_nz+i,1,MPIU_INT,send_rank[i],tag1,comm,s_waits1+i);CHKERRQ(ierr);
2594     }
2595     /* wait on receives of nzlocal; allocate space for rbuf_j, rbuf_a */
2596     count = nrecvs;
2597     while (count) {
2598       ierr = MPI_Waitany(nrecvs,r_waits1,&imdex,&recv_status);CHKERRQ(ierr);
2599 
2600       recv_rank[imdex] = recv_status.MPI_SOURCE;
2601       /* allocate rbuf_a and rbuf_j; then post receives of rbuf_j */
2602       ierr = PetscMalloc1((rbuf_nz[imdex]+1),&rbuf_a[imdex]);CHKERRQ(ierr);
2603 
2604       i = rowrange[recv_status.MPI_SOURCE+1] - rowrange[recv_status.MPI_SOURCE]; /* number of expected mat->i */
2605 
2606       rbuf_nz[imdex] += i + 2;
2607 
2608       ierr = PetscMalloc1(rbuf_nz[imdex],&rbuf_j[imdex]);CHKERRQ(ierr);
2609       ierr = MPI_Irecv(rbuf_j[imdex],rbuf_nz[imdex],MPIU_INT,recv_status.MPI_SOURCE,tag2,comm,r_waits2+imdex);CHKERRQ(ierr);
2610       count--;
2611     }
2612     /* wait on sends of nzlocal */
2613     if (nsends) {ierr = MPI_Waitall(nsends,s_waits1,send_status);CHKERRQ(ierr);}
2614     /* send mat->i,j to others, and recv from other's */
2615     /*------------------------------------------------*/
2616     for (i=0; i<nsends; i++) {
2617       j    = nzlocal + rowrange[rank+1] - rowrange[rank] + 1;
2618       ierr = MPI_Isend(sbuf_j,j,MPIU_INT,send_rank[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
2619     }
2620     /* wait on receives of mat->i,j */
2621     /*------------------------------*/
2622     count = nrecvs;
2623     while (count) {
2624       ierr = MPI_Waitany(nrecvs,r_waits2,&imdex,&recv_status);CHKERRQ(ierr);
2625       if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2626       count--;
2627     }
2628     /* wait on sends of mat->i,j */
2629     /*---------------------------*/
2630     if (nsends) {
2631       ierr = MPI_Waitall(nsends,s_waits2,send_status);CHKERRQ(ierr);
2632     }
2633   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2634 
2635   /* post receives, send and receive mat->a */
2636   /*----------------------------------------*/
2637   for (imdex=0; imdex<nrecvs; imdex++) {
2638     ierr = MPI_Irecv(rbuf_a[imdex],rbuf_nz[imdex],MPIU_SCALAR,recv_rank[imdex],tag3,comm,r_waits3+imdex);CHKERRQ(ierr);
2639   }
2640   for (i=0; i<nsends; i++) {
2641     ierr = MPI_Isend(sbuf_a,nzlocal,MPIU_SCALAR,send_rank[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
2642   }
2643   count = nrecvs;
2644   while (count) {
2645     ierr = MPI_Waitany(nrecvs,r_waits3,&imdex,&recv_status);CHKERRQ(ierr);
2646     if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2647     count--;
2648   }
2649   if (nsends) {
2650     ierr = MPI_Waitall(nsends,s_waits3,send_status);CHKERRQ(ierr);
2651   }
2652 
2653   ierr = PetscFree2(s_waits3,send_status);CHKERRQ(ierr);
2654 
2655   /* create redundant matrix */
2656   /*-------------------------*/
2657   if (reuse == MAT_INITIAL_MATRIX) {
2658     const PetscInt *range;
2659     PetscInt       rstart_sub,rend_sub,mloc_sub;
2660 
2661     /* compute rownz_max for preallocation */
2662     for (imdex=0; imdex<nrecvs; imdex++) {
2663       j    = rowrange[recv_rank[imdex]+1] - rowrange[recv_rank[imdex]];
2664       rptr = rbuf_j[imdex];
2665       for (i=0; i<j; i++) {
2666         ncols = rptr[i+1] - rptr[i];
2667         if (rownz_max < ncols) rownz_max = ncols;
2668       }
2669     }
2670 
2671     ierr = MatCreate(subcomm,&C);CHKERRQ(ierr);
2672 
2673     /* get local size of redundant matrix
2674        - mloc_sub is chosen for PETSC_SUBCOMM_INTERLACED, works for other types, but may not efficient! */
2675     ierr = MatGetOwnershipRanges(mat,&range);CHKERRQ(ierr);
2676     rstart_sub = range[nsubcomm*subrank];
2677     if (subrank+1 < subsize) { /* not the last proc in subcomm */
2678       rend_sub = range[nsubcomm*(subrank+1)];
2679     } else {
2680       rend_sub = mat->rmap->N;
2681     }
2682     mloc_sub = rend_sub - rstart_sub;
2683 
2684     if (M == N) {
2685       ierr = MatSetSizes(C,mloc_sub,mloc_sub,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
2686     } else { /* non-square matrix */
2687       ierr = MatSetSizes(C,mloc_sub,PETSC_DECIDE,PETSC_DECIDE,mat->cmap->N);CHKERRQ(ierr);
2688     }
2689     ierr = MatSetBlockSizesFromMats(C,mat,mat);CHKERRQ(ierr);
2690     ierr = MatSetFromOptions(C);CHKERRQ(ierr);
2691     ierr = MatSeqAIJSetPreallocation(C,rownz_max,NULL);CHKERRQ(ierr);
2692     ierr = MatMPIAIJSetPreallocation(C,rownz_max,NULL,rownz_max,NULL);CHKERRQ(ierr);
2693   } else {
2694     C = *matredundant;
2695   }
2696 
2697   /* insert local matrix entries */
2698   rptr = sbuf_j;
2699   cols = sbuf_j + rend-rstart + 1;
2700   vals = sbuf_a;
2701   for (i=0; i<rend-rstart; i++) {
2702     row   = i + rstart;
2703     ncols = rptr[i+1] - rptr[i];
2704     ierr  = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2705     vals += ncols;
2706     cols += ncols;
2707   }
2708   /* insert received matrix entries */
2709   for (imdex=0; imdex<nrecvs; imdex++) {
2710     rstart = rowrange[recv_rank[imdex]];
2711     rend   = rowrange[recv_rank[imdex]+1];
2712     /* printf("[%d] insert rows %d - %d\n",rank,rstart,rend-1); */
2713     rptr   = rbuf_j[imdex];
2714     cols   = rbuf_j[imdex] + rend-rstart + 1;
2715     vals   = rbuf_a[imdex];
2716     for (i=0; i<rend-rstart; i++) {
2717       row   = i + rstart;
2718       ncols = rptr[i+1] - rptr[i];
2719       ierr  = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2720       vals += ncols;
2721       cols += ncols;
2722     }
2723   }
2724   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2725   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2726 
2727   if (reuse == MAT_INITIAL_MATRIX) {
2728     *matredundant = C;
2729 
2730     /* create a supporting struct and attach it to C for reuse */
2731     ierr = PetscNewLog(C,&redund);CHKERRQ(ierr);
2732     C->redundant      = redund;
2733     redund->nzlocal   = nzlocal;
2734     redund->nsends    = nsends;
2735     redund->nrecvs    = nrecvs;
2736     redund->send_rank = send_rank;
2737     redund->recv_rank = recv_rank;
2738     redund->sbuf_nz   = sbuf_nz;
2739     redund->rbuf_nz   = rbuf_nz;
2740     redund->sbuf_j    = sbuf_j;
2741     redund->sbuf_a    = sbuf_a;
2742     redund->rbuf_j    = rbuf_j;
2743     redund->rbuf_a    = rbuf_a;
2744     redund->subcomm   = subcomm;
2745     redund->type      = PETSC_SUBCOMM_INTERLACED;
2746   }
2747   PetscFunctionReturn(0);
2748 }
2749 
2750 #undef __FUNCT__
2751 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ"
2752 PetscErrorCode MatGetRedundantMatrix_MPIAIJ(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,MatReuse reuse,Mat *matredundant)
2753 {
2754   PetscErrorCode ierr;
2755   MPI_Comm       comm;
2756   PetscMPIInt    size,subsize;
2757   PetscInt       mloc_sub,rstart,rend,M=mat->rmap->N,N=mat->cmap->N;
2758   Mat_Redundant  *redund=NULL;
2759   PetscSubcomm   psubcomm=NULL;
2760   MPI_Comm       subcomm_in=subcomm;
2761   Mat            *matseq;
2762   IS             isrow,iscol;
2763 
2764   PetscFunctionBegin;
2765   if (subcomm_in == MPI_COMM_NULL) { /* user does not provide subcomm */
2766     if (reuse == MAT_INITIAL_MATRIX) {
2767       /* create psubcomm, then get subcomm */
2768       ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
2769       ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2770       if (nsubcomm < 1 || nsubcomm > size) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"nsubcomm must between 1 and %D",size);
2771 
2772       ierr = PetscSubcommCreate(comm,&psubcomm);CHKERRQ(ierr);
2773       ierr = PetscSubcommSetNumber(psubcomm,nsubcomm);CHKERRQ(ierr);
2774       ierr = PetscSubcommSetType(psubcomm,PETSC_SUBCOMM_CONTIGUOUS);CHKERRQ(ierr);
2775       ierr = PetscSubcommSetFromOptions(psubcomm);CHKERRQ(ierr);
2776       subcomm = psubcomm->comm;
2777       if (psubcomm->type == PETSC_SUBCOMM_INTERLACED) {
2778         ierr = MatGetRedundantMatrix_MPIAIJ_interlaced(mat,nsubcomm,subcomm,reuse,matredundant);CHKERRQ(ierr);
2779         (*matredundant)->redundant->psubcomm = psubcomm;
2780         PetscFunctionReturn(0);
2781       }
2782     } else { /* retrieve psubcomm and subcomm */
2783       ierr = PetscObjectGetComm((PetscObject)(*matredundant),&subcomm);CHKERRQ(ierr);
2784       redund = (*matredundant)->redundant;
2785       if (redund->type == PETSC_SUBCOMM_INTERLACED) {
2786         ierr = MatGetRedundantMatrix_MPIAIJ_interlaced(mat,nsubcomm,subcomm,reuse,matredundant);CHKERRQ(ierr);
2787         PetscFunctionReturn(0);
2788       }
2789     }
2790   }
2791 
2792   /* use MPI subcomm via MatGetSubMatrices(); use subcomm_in or psubcomm->comm (psubcomm->type != INTERLACED) */
2793   ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2794   if (reuse == MAT_INITIAL_MATRIX) {
2795     /* create a local sequential matrix matseq[0] */
2796     mloc_sub = PETSC_DECIDE;
2797     ierr = PetscSplitOwnership(subcomm,&mloc_sub,&M);CHKERRQ(ierr);
2798     ierr = MPI_Scan(&mloc_sub,&rend,1,MPIU_INT,MPI_SUM,subcomm);CHKERRQ(ierr);
2799     rstart = rend - mloc_sub;
2800     ierr = ISCreateStride(PETSC_COMM_SELF,mloc_sub,rstart,1,&isrow);CHKERRQ(ierr);
2801     ierr = ISCreateStride(PETSC_COMM_SELF,N,0,1,&iscol);CHKERRQ(ierr);
2802   } else { /* reuse == MAT_REUSE_MATRIX */
2803     redund = (*matredundant)->redundant;
2804     isrow  = redund->isrow;
2805     iscol  = redund->iscol;
2806     matseq = redund->matseq;
2807   }
2808   ierr = MatGetSubMatrices(mat,1,&isrow,&iscol,reuse,&matseq);CHKERRQ(ierr);
2809   ierr = MatCreateMPIMatConcatenateSeqMat(subcomm,matseq[0],PETSC_DECIDE,reuse,matredundant);CHKERRQ(ierr);
2810 
2811   if (reuse == MAT_INITIAL_MATRIX) {
2812     /* create a supporting struct and attach it to C for reuse */
2813     ierr = PetscNewLog(*matredundant,&redund);CHKERRQ(ierr);
2814     (*matredundant)->redundant = redund;
2815     redund->isrow              = isrow;
2816     redund->iscol              = iscol;
2817     redund->matseq             = matseq;
2818     redund->subcomm            = subcomm;
2819     redund->type               = PETSC_SUBCOMM_CONTIGUOUS;
2820     redund->psubcomm           = psubcomm;
2821   }
2822   PetscFunctionReturn(0);
2823 }
2824 
2825 #undef __FUNCT__
2826 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2827 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2828 {
2829   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2830   PetscErrorCode ierr;
2831   PetscInt       i,*idxb = 0;
2832   PetscScalar    *va,*vb;
2833   Vec            vtmp;
2834 
2835   PetscFunctionBegin;
2836   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2837   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2838   if (idx) {
2839     for (i=0; i<A->rmap->n; i++) {
2840       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2841     }
2842   }
2843 
2844   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2845   if (idx) {
2846     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2847   }
2848   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2849   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2850 
2851   for (i=0; i<A->rmap->n; i++) {
2852     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2853       va[i] = vb[i];
2854       if (idx) idx[i] = a->garray[idxb[i]];
2855     }
2856   }
2857 
2858   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2859   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2860   ierr = PetscFree(idxb);CHKERRQ(ierr);
2861   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2862   PetscFunctionReturn(0);
2863 }
2864 
2865 #undef __FUNCT__
2866 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2867 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2868 {
2869   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2870   PetscErrorCode ierr;
2871   PetscInt       i,*idxb = 0;
2872   PetscScalar    *va,*vb;
2873   Vec            vtmp;
2874 
2875   PetscFunctionBegin;
2876   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2877   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2878   if (idx) {
2879     for (i=0; i<A->cmap->n; i++) {
2880       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2881     }
2882   }
2883 
2884   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2885   if (idx) {
2886     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2887   }
2888   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2889   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2890 
2891   for (i=0; i<A->rmap->n; i++) {
2892     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2893       va[i] = vb[i];
2894       if (idx) idx[i] = a->garray[idxb[i]];
2895     }
2896   }
2897 
2898   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2899   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2900   ierr = PetscFree(idxb);CHKERRQ(ierr);
2901   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2902   PetscFunctionReturn(0);
2903 }
2904 
2905 #undef __FUNCT__
2906 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2907 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2908 {
2909   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2910   PetscInt       n      = A->rmap->n;
2911   PetscInt       cstart = A->cmap->rstart;
2912   PetscInt       *cmap  = mat->garray;
2913   PetscInt       *diagIdx, *offdiagIdx;
2914   Vec            diagV, offdiagV;
2915   PetscScalar    *a, *diagA, *offdiagA;
2916   PetscInt       r;
2917   PetscErrorCode ierr;
2918 
2919   PetscFunctionBegin;
2920   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2921   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &diagV);CHKERRQ(ierr);
2922   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &offdiagV);CHKERRQ(ierr);
2923   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2924   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2925   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2926   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2927   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2928   for (r = 0; r < n; ++r) {
2929     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2930       a[r]   = diagA[r];
2931       idx[r] = cstart + diagIdx[r];
2932     } else {
2933       a[r]   = offdiagA[r];
2934       idx[r] = cmap[offdiagIdx[r]];
2935     }
2936   }
2937   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2938   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2939   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2940   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2941   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2942   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2943   PetscFunctionReturn(0);
2944 }
2945 
2946 #undef __FUNCT__
2947 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2948 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2949 {
2950   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2951   PetscInt       n      = A->rmap->n;
2952   PetscInt       cstart = A->cmap->rstart;
2953   PetscInt       *cmap  = mat->garray;
2954   PetscInt       *diagIdx, *offdiagIdx;
2955   Vec            diagV, offdiagV;
2956   PetscScalar    *a, *diagA, *offdiagA;
2957   PetscInt       r;
2958   PetscErrorCode ierr;
2959 
2960   PetscFunctionBegin;
2961   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2962   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &diagV);CHKERRQ(ierr);
2963   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &offdiagV);CHKERRQ(ierr);
2964   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2965   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2966   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2967   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2968   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2969   for (r = 0; r < n; ++r) {
2970     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2971       a[r]   = diagA[r];
2972       idx[r] = cstart + diagIdx[r];
2973     } else {
2974       a[r]   = offdiagA[r];
2975       idx[r] = cmap[offdiagIdx[r]];
2976     }
2977   }
2978   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2979   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2980   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2981   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2982   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2983   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2984   PetscFunctionReturn(0);
2985 }
2986 
2987 #undef __FUNCT__
2988 #define __FUNCT__ "MatGetSeqNonzeroStructure_MPIAIJ"
2989 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
2990 {
2991   PetscErrorCode ierr;
2992   Mat            *dummy;
2993 
2994   PetscFunctionBegin;
2995   ierr    = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
2996   *newmat = *dummy;
2997   ierr    = PetscFree(dummy);CHKERRQ(ierr);
2998   PetscFunctionReturn(0);
2999 }
3000 
3001 #undef __FUNCT__
3002 #define __FUNCT__ "MatInvertBlockDiagonal_MPIAIJ"
3003 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
3004 {
3005   Mat_MPIAIJ     *a = (Mat_MPIAIJ*) A->data;
3006   PetscErrorCode ierr;
3007 
3008   PetscFunctionBegin;
3009   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
3010   PetscFunctionReturn(0);
3011 }
3012 
3013 #undef __FUNCT__
3014 #define __FUNCT__ "MatSetRandom_MPIAIJ"
3015 static PetscErrorCode  MatSetRandom_MPIAIJ(Mat x,PetscRandom rctx)
3016 {
3017   PetscErrorCode ierr;
3018   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)x->data;
3019 
3020   PetscFunctionBegin;
3021   ierr = MatSetRandom(aij->A,rctx);CHKERRQ(ierr);
3022   ierr = MatSetRandom(aij->B,rctx);CHKERRQ(ierr);
3023   ierr = MatAssemblyBegin(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3024   ierr = MatAssemblyEnd(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3025   PetscFunctionReturn(0);
3026 }
3027 
3028 /* -------------------------------------------------------------------*/
3029 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
3030                                        MatGetRow_MPIAIJ,
3031                                        MatRestoreRow_MPIAIJ,
3032                                        MatMult_MPIAIJ,
3033                                 /* 4*/ MatMultAdd_MPIAIJ,
3034                                        MatMultTranspose_MPIAIJ,
3035                                        MatMultTransposeAdd_MPIAIJ,
3036 #if defined(PETSC_HAVE_PBGL)
3037                                        MatSolve_MPIAIJ,
3038 #else
3039                                        0,
3040 #endif
3041                                        0,
3042                                        0,
3043                                 /*10*/ 0,
3044                                        0,
3045                                        0,
3046                                        MatSOR_MPIAIJ,
3047                                        MatTranspose_MPIAIJ,
3048                                 /*15*/ MatGetInfo_MPIAIJ,
3049                                        MatEqual_MPIAIJ,
3050                                        MatGetDiagonal_MPIAIJ,
3051                                        MatDiagonalScale_MPIAIJ,
3052                                        MatNorm_MPIAIJ,
3053                                 /*20*/ MatAssemblyBegin_MPIAIJ,
3054                                        MatAssemblyEnd_MPIAIJ,
3055                                        MatSetOption_MPIAIJ,
3056                                        MatZeroEntries_MPIAIJ,
3057                                 /*24*/ MatZeroRows_MPIAIJ,
3058                                        0,
3059 #if defined(PETSC_HAVE_PBGL)
3060                                        0,
3061 #else
3062                                        0,
3063 #endif
3064                                        0,
3065                                        0,
3066                                 /*29*/ MatSetUp_MPIAIJ,
3067 #if defined(PETSC_HAVE_PBGL)
3068                                        0,
3069 #else
3070                                        0,
3071 #endif
3072                                        0,
3073                                        0,
3074                                        0,
3075                                 /*34*/ MatDuplicate_MPIAIJ,
3076                                        0,
3077                                        0,
3078                                        0,
3079                                        0,
3080                                 /*39*/ MatAXPY_MPIAIJ,
3081                                        MatGetSubMatrices_MPIAIJ,
3082                                        MatIncreaseOverlap_MPIAIJ,
3083                                        MatGetValues_MPIAIJ,
3084                                        MatCopy_MPIAIJ,
3085                                 /*44*/ MatGetRowMax_MPIAIJ,
3086                                        MatScale_MPIAIJ,
3087                                        0,
3088                                        MatDiagonalSet_MPIAIJ,
3089                                        MatZeroRowsColumns_MPIAIJ,
3090                                 /*49*/ MatSetRandom_MPIAIJ,
3091                                        0,
3092                                        0,
3093                                        0,
3094                                        0,
3095                                 /*54*/ MatFDColoringCreate_MPIXAIJ,
3096                                        0,
3097                                        MatSetUnfactored_MPIAIJ,
3098                                        MatPermute_MPIAIJ,
3099                                        0,
3100                                 /*59*/ MatGetSubMatrix_MPIAIJ,
3101                                        MatDestroy_MPIAIJ,
3102                                        MatView_MPIAIJ,
3103                                        0,
3104                                        MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ,
3105                                 /*64*/ MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ,
3106                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
3107                                        0,
3108                                        0,
3109                                        0,
3110                                 /*69*/ MatGetRowMaxAbs_MPIAIJ,
3111                                        MatGetRowMinAbs_MPIAIJ,
3112                                        0,
3113                                        MatSetColoring_MPIAIJ,
3114                                        0,
3115                                        MatSetValuesAdifor_MPIAIJ,
3116                                 /*75*/ MatFDColoringApply_AIJ,
3117                                        0,
3118                                        0,
3119                                        0,
3120                                        MatFindZeroDiagonals_MPIAIJ,
3121                                 /*80*/ 0,
3122                                        0,
3123                                        0,
3124                                 /*83*/ MatLoad_MPIAIJ,
3125                                        0,
3126                                        0,
3127                                        0,
3128                                        0,
3129                                        0,
3130                                 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
3131                                        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
3132                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
3133                                        MatPtAP_MPIAIJ_MPIAIJ,
3134                                        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
3135                                 /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
3136                                        0,
3137                                        0,
3138                                        0,
3139                                        0,
3140                                 /*99*/ 0,
3141                                        0,
3142                                        0,
3143                                        MatConjugate_MPIAIJ,
3144                                        0,
3145                                 /*104*/MatSetValuesRow_MPIAIJ,
3146                                        MatRealPart_MPIAIJ,
3147                                        MatImaginaryPart_MPIAIJ,
3148                                        0,
3149                                        0,
3150                                 /*109*/0,
3151                                        MatGetRedundantMatrix_MPIAIJ,
3152                                        MatGetRowMin_MPIAIJ,
3153                                        0,
3154                                        0,
3155                                 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
3156                                        0,
3157                                        0,
3158                                        0,
3159                                        0,
3160                                 /*119*/0,
3161                                        0,
3162                                        0,
3163                                        0,
3164                                        MatGetMultiProcBlock_MPIAIJ,
3165                                 /*124*/MatFindNonzeroRows_MPIAIJ,
3166                                        MatGetColumnNorms_MPIAIJ,
3167                                        MatInvertBlockDiagonal_MPIAIJ,
3168                                        0,
3169                                        MatGetSubMatricesParallel_MPIAIJ,
3170                                 /*129*/0,
3171                                        MatTransposeMatMult_MPIAIJ_MPIAIJ,
3172                                        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
3173                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
3174                                        0,
3175                                 /*134*/0,
3176                                        0,
3177                                        0,
3178                                        0,
3179                                        0,
3180                                 /*139*/0,
3181                                        0,
3182                                        0,
3183                                        MatFDColoringSetUp_MPIXAIJ,
3184                                        0,
3185                                 /*144*/MatCreateMPIMatConcatenateSeqMat_MPIAIJ
3186 };
3187 
3188 /* ----------------------------------------------------------------------------------------*/
3189 
3190 #undef __FUNCT__
3191 #define __FUNCT__ "MatStoreValues_MPIAIJ"
3192 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
3193 {
3194   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3195   PetscErrorCode ierr;
3196 
3197   PetscFunctionBegin;
3198   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
3199   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
3200   PetscFunctionReturn(0);
3201 }
3202 
3203 #undef __FUNCT__
3204 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
3205 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
3206 {
3207   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3208   PetscErrorCode ierr;
3209 
3210   PetscFunctionBegin;
3211   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
3212   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
3213   PetscFunctionReturn(0);
3214 }
3215 
3216 #undef __FUNCT__
3217 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
3218 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3219 {
3220   Mat_MPIAIJ     *b;
3221   PetscErrorCode ierr;
3222 
3223   PetscFunctionBegin;
3224   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3225   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3226   b = (Mat_MPIAIJ*)B->data;
3227 
3228   if (!B->preallocated) {
3229     /* Explicitly create 2 MATSEQAIJ matrices. */
3230     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
3231     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
3232     ierr = MatSetBlockSizesFromMats(b->A,B,B);CHKERRQ(ierr);
3233     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
3234     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->A);CHKERRQ(ierr);
3235     ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
3236     ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
3237     ierr = MatSetBlockSizesFromMats(b->B,B,B);CHKERRQ(ierr);
3238     ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
3239     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->B);CHKERRQ(ierr);
3240   }
3241 
3242   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
3243   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
3244   B->preallocated = PETSC_TRUE;
3245   PetscFunctionReturn(0);
3246 }
3247 
3248 #undef __FUNCT__
3249 #define __FUNCT__ "MatDuplicate_MPIAIJ"
3250 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
3251 {
3252   Mat            mat;
3253   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
3254   PetscErrorCode ierr;
3255 
3256   PetscFunctionBegin;
3257   *newmat = 0;
3258   ierr    = MatCreate(PetscObjectComm((PetscObject)matin),&mat);CHKERRQ(ierr);
3259   ierr    = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
3260   ierr    = MatSetBlockSizesFromMats(mat,matin,matin);CHKERRQ(ierr);
3261   ierr    = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
3262   ierr    = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
3263   a       = (Mat_MPIAIJ*)mat->data;
3264 
3265   mat->factortype   = matin->factortype;
3266   mat->assembled    = PETSC_TRUE;
3267   mat->insertmode   = NOT_SET_VALUES;
3268   mat->preallocated = PETSC_TRUE;
3269 
3270   a->size         = oldmat->size;
3271   a->rank         = oldmat->rank;
3272   a->donotstash   = oldmat->donotstash;
3273   a->roworiented  = oldmat->roworiented;
3274   a->rowindices   = 0;
3275   a->rowvalues    = 0;
3276   a->getrowactive = PETSC_FALSE;
3277 
3278   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
3279   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
3280 
3281   if (oldmat->colmap) {
3282 #if defined(PETSC_USE_CTABLE)
3283     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
3284 #else
3285     ierr = PetscMalloc1((mat->cmap->N),&a->colmap);CHKERRQ(ierr);
3286     ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3287     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3288 #endif
3289   } else a->colmap = 0;
3290   if (oldmat->garray) {
3291     PetscInt len;
3292     len  = oldmat->B->cmap->n;
3293     ierr = PetscMalloc1((len+1),&a->garray);CHKERRQ(ierr);
3294     ierr = PetscLogObjectMemory((PetscObject)mat,len*sizeof(PetscInt));CHKERRQ(ierr);
3295     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
3296   } else a->garray = 0;
3297 
3298   ierr    = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
3299   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->lvec);CHKERRQ(ierr);
3300   ierr    = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
3301   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->Mvctx);CHKERRQ(ierr);
3302   ierr    = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
3303   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->A);CHKERRQ(ierr);
3304   ierr    = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
3305   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->B);CHKERRQ(ierr);
3306   ierr    = PetscFunctionListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
3307   *newmat = mat;
3308   PetscFunctionReturn(0);
3309 }
3310 
3311 
3312 
3313 #undef __FUNCT__
3314 #define __FUNCT__ "MatLoad_MPIAIJ"
3315 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
3316 {
3317   PetscScalar    *vals,*svals;
3318   MPI_Comm       comm;
3319   PetscErrorCode ierr;
3320   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
3321   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0,grows,gcols;
3322   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
3323   PetscInt       *ourlens = NULL,*procsnz = NULL,*offlens = NULL,jj,*mycols,*smycols;
3324   PetscInt       cend,cstart,n,*rowners,sizesset=1;
3325   int            fd;
3326   PetscInt       bs = 1;
3327 
3328   PetscFunctionBegin;
3329   ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
3330   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3331   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3332   if (!rank) {
3333     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
3334     ierr = PetscBinaryRead(fd,(char*)header,4,PETSC_INT);CHKERRQ(ierr);
3335     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
3336   }
3337 
3338   ierr = PetscOptionsBegin(comm,NULL,"Options for loading SEQAIJ matrix","Mat");CHKERRQ(ierr);
3339   ierr = PetscOptionsInt("-matload_block_size","Set the blocksize used to store the matrix","MatLoad",bs,&bs,NULL);CHKERRQ(ierr);
3340   ierr = PetscOptionsEnd();CHKERRQ(ierr);
3341 
3342   if (newMat->rmap->n < 0 && newMat->rmap->N < 0 && newMat->cmap->n < 0 && newMat->cmap->N < 0) sizesset = 0;
3343 
3344   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
3345   M    = header[1]; N = header[2];
3346   /* If global rows/cols are set to PETSC_DECIDE, set it to the sizes given in the file */
3347   if (sizesset && newMat->rmap->N < 0) newMat->rmap->N = M;
3348   if (sizesset && newMat->cmap->N < 0) newMat->cmap->N = N;
3349 
3350   /* If global sizes are set, check if they are consistent with that given in the file */
3351   if (sizesset) {
3352     ierr = MatGetSize(newMat,&grows,&gcols);CHKERRQ(ierr);
3353   }
3354   if (sizesset && newMat->rmap->N != grows) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows:Matrix in file has (%d) and input matrix has (%d)",M,grows);
3355   if (sizesset && newMat->cmap->N != gcols) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of cols:Matrix in file has (%d) and input matrix has (%d)",N,gcols);
3356 
3357   /* determine ownership of all (block) rows */
3358   if (M%bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows (%d) and block size (%d)",M,bs);
3359   if (newMat->rmap->n < 0) m = bs*((M/bs)/size + (((M/bs) % size) > rank));    /* PETSC_DECIDE */
3360   else m = newMat->rmap->n; /* Set by user */
3361 
3362   ierr = PetscMalloc1((size+1),&rowners);CHKERRQ(ierr);
3363   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
3364 
3365   /* First process needs enough room for process with most rows */
3366   if (!rank) {
3367     mmax = rowners[1];
3368     for (i=2; i<=size; i++) {
3369       mmax = PetscMax(mmax, rowners[i]);
3370     }
3371   } else mmax = -1;             /* unused, but compilers complain */
3372 
3373   rowners[0] = 0;
3374   for (i=2; i<=size; i++) {
3375     rowners[i] += rowners[i-1];
3376   }
3377   rstart = rowners[rank];
3378   rend   = rowners[rank+1];
3379 
3380   /* distribute row lengths to all processors */
3381   ierr = PetscMalloc2(m,&ourlens,m,&offlens);CHKERRQ(ierr);
3382   if (!rank) {
3383     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
3384     ierr = PetscMalloc1(mmax,&rowlengths);CHKERRQ(ierr);
3385     ierr = PetscCalloc1(size,&procsnz);CHKERRQ(ierr);
3386     for (j=0; j<m; j++) {
3387       procsnz[0] += ourlens[j];
3388     }
3389     for (i=1; i<size; i++) {
3390       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
3391       /* calculate the number of nonzeros on each processor */
3392       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
3393         procsnz[i] += rowlengths[j];
3394       }
3395       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3396     }
3397     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
3398   } else {
3399     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3400   }
3401 
3402   if (!rank) {
3403     /* determine max buffer needed and allocate it */
3404     maxnz = 0;
3405     for (i=0; i<size; i++) {
3406       maxnz = PetscMax(maxnz,procsnz[i]);
3407     }
3408     ierr = PetscMalloc1(maxnz,&cols);CHKERRQ(ierr);
3409 
3410     /* read in my part of the matrix column indices  */
3411     nz   = procsnz[0];
3412     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
3413     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
3414 
3415     /* read in every one elses and ship off */
3416     for (i=1; i<size; i++) {
3417       nz   = procsnz[i];
3418       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
3419       ierr = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3420     }
3421     ierr = PetscFree(cols);CHKERRQ(ierr);
3422   } else {
3423     /* determine buffer space needed for message */
3424     nz = 0;
3425     for (i=0; i<m; i++) {
3426       nz += ourlens[i];
3427     }
3428     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
3429 
3430     /* receive message of column indices*/
3431     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3432   }
3433 
3434   /* determine column ownership if matrix is not square */
3435   if (N != M) {
3436     if (newMat->cmap->n < 0) n = N/size + ((N % size) > rank);
3437     else n = newMat->cmap->n;
3438     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3439     cstart = cend - n;
3440   } else {
3441     cstart = rstart;
3442     cend   = rend;
3443     n      = cend - cstart;
3444   }
3445 
3446   /* loop over local rows, determining number of off diagonal entries */
3447   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
3448   jj   = 0;
3449   for (i=0; i<m; i++) {
3450     for (j=0; j<ourlens[i]; j++) {
3451       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
3452       jj++;
3453     }
3454   }
3455 
3456   for (i=0; i<m; i++) {
3457     ourlens[i] -= offlens[i];
3458   }
3459   if (!sizesset) {
3460     ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
3461   }
3462 
3463   if (bs > 1) {ierr = MatSetBlockSize(newMat,bs);CHKERRQ(ierr);}
3464 
3465   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
3466 
3467   for (i=0; i<m; i++) {
3468     ourlens[i] += offlens[i];
3469   }
3470 
3471   if (!rank) {
3472     ierr = PetscMalloc1((maxnz+1),&vals);CHKERRQ(ierr);
3473 
3474     /* read in my part of the matrix numerical values  */
3475     nz   = procsnz[0];
3476     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3477 
3478     /* insert into matrix */
3479     jj      = rstart;
3480     smycols = mycols;
3481     svals   = vals;
3482     for (i=0; i<m; i++) {
3483       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3484       smycols += ourlens[i];
3485       svals   += ourlens[i];
3486       jj++;
3487     }
3488 
3489     /* read in other processors and ship out */
3490     for (i=1; i<size; i++) {
3491       nz   = procsnz[i];
3492       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3493       ierr = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3494     }
3495     ierr = PetscFree(procsnz);CHKERRQ(ierr);
3496   } else {
3497     /* receive numeric values */
3498     ierr = PetscMalloc1((nz+1),&vals);CHKERRQ(ierr);
3499 
3500     /* receive message of values*/
3501     ierr = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3502 
3503     /* insert into matrix */
3504     jj      = rstart;
3505     smycols = mycols;
3506     svals   = vals;
3507     for (i=0; i<m; i++) {
3508       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3509       smycols += ourlens[i];
3510       svals   += ourlens[i];
3511       jj++;
3512     }
3513   }
3514   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
3515   ierr = PetscFree(vals);CHKERRQ(ierr);
3516   ierr = PetscFree(mycols);CHKERRQ(ierr);
3517   ierr = PetscFree(rowners);CHKERRQ(ierr);
3518   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3519   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3520   PetscFunctionReturn(0);
3521 }
3522 
3523 #undef __FUNCT__
3524 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3525 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3526 {
3527   PetscErrorCode ierr;
3528   IS             iscol_local;
3529   PetscInt       csize;
3530 
3531   PetscFunctionBegin;
3532   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3533   if (call == MAT_REUSE_MATRIX) {
3534     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3535     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3536   } else {
3537     PetscInt cbs;
3538     ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3539     ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
3540     ierr = ISSetBlockSize(iscol_local,cbs);CHKERRQ(ierr);
3541   }
3542   ierr = MatGetSubMatrix_MPIAIJ_Private(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3543   if (call == MAT_INITIAL_MATRIX) {
3544     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3545     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3546   }
3547   PetscFunctionReturn(0);
3548 }
3549 
3550 extern PetscErrorCode MatGetSubMatrices_MPIAIJ_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool*,Mat*);
3551 #undef __FUNCT__
3552 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ_Private"
3553 /*
3554     Not great since it makes two copies of the submatrix, first an SeqAIJ
3555   in local and then by concatenating the local matrices the end result.
3556   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3557 
3558   Note: This requires a sequential iscol with all indices.
3559 */
3560 PetscErrorCode MatGetSubMatrix_MPIAIJ_Private(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3561 {
3562   PetscErrorCode ierr;
3563   PetscMPIInt    rank,size;
3564   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3565   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal,ncol;
3566   PetscBool      allcolumns, colflag;
3567   Mat            M,Mreuse;
3568   MatScalar      *vwork,*aa;
3569   MPI_Comm       comm;
3570   Mat_SeqAIJ     *aij;
3571 
3572   PetscFunctionBegin;
3573   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3574   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3575   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3576 
3577   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3578   ierr = ISGetLocalSize(iscol,&ncol);CHKERRQ(ierr);
3579   if (colflag && ncol == mat->cmap->N) {
3580     allcolumns = PETSC_TRUE;
3581   } else {
3582     allcolumns = PETSC_FALSE;
3583   }
3584   if (call ==  MAT_REUSE_MATRIX) {
3585     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Mreuse);CHKERRQ(ierr);
3586     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3587     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3588   } else {
3589     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3590   }
3591 
3592   /*
3593       m - number of local rows
3594       n - number of columns (same on all processors)
3595       rstart - first row in new global matrix generated
3596   */
3597   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3598   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3599   if (call == MAT_INITIAL_MATRIX) {
3600     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3601     ii  = aij->i;
3602     jj  = aij->j;
3603 
3604     /*
3605         Determine the number of non-zeros in the diagonal and off-diagonal
3606         portions of the matrix in order to do correct preallocation
3607     */
3608 
3609     /* first get start and end of "diagonal" columns */
3610     if (csize == PETSC_DECIDE) {
3611       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3612       if (mglobal == n) { /* square matrix */
3613         nlocal = m;
3614       } else {
3615         nlocal = n/size + ((n % size) > rank);
3616       }
3617     } else {
3618       nlocal = csize;
3619     }
3620     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3621     rstart = rend - nlocal;
3622     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);
3623 
3624     /* next, compute all the lengths */
3625     ierr  = PetscMalloc1((2*m+1),&dlens);CHKERRQ(ierr);
3626     olens = dlens + m;
3627     for (i=0; i<m; i++) {
3628       jend = ii[i+1] - ii[i];
3629       olen = 0;
3630       dlen = 0;
3631       for (j=0; j<jend; j++) {
3632         if (*jj < rstart || *jj >= rend) olen++;
3633         else dlen++;
3634         jj++;
3635       }
3636       olens[i] = olen;
3637       dlens[i] = dlen;
3638     }
3639     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3640     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3641     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3642     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3643     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3644     ierr = PetscFree(dlens);CHKERRQ(ierr);
3645   } else {
3646     PetscInt ml,nl;
3647 
3648     M    = *newmat;
3649     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3650     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3651     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3652     /*
3653          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3654        rather than the slower MatSetValues().
3655     */
3656     M->was_assembled = PETSC_TRUE;
3657     M->assembled     = PETSC_FALSE;
3658   }
3659   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3660   aij  = (Mat_SeqAIJ*)(Mreuse)->data;
3661   ii   = aij->i;
3662   jj   = aij->j;
3663   aa   = aij->a;
3664   for (i=0; i<m; i++) {
3665     row   = rstart + i;
3666     nz    = ii[i+1] - ii[i];
3667     cwork = jj;     jj += nz;
3668     vwork = aa;     aa += nz;
3669     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3670   }
3671 
3672   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3673   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3674   *newmat = M;
3675 
3676   /* save submatrix used in processor for next request */
3677   if (call ==  MAT_INITIAL_MATRIX) {
3678     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3679     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3680   }
3681   PetscFunctionReturn(0);
3682 }
3683 
3684 #undef __FUNCT__
3685 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3686 PetscErrorCode  MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3687 {
3688   PetscInt       m,cstart, cend,j,nnz,i,d;
3689   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3690   const PetscInt *JJ;
3691   PetscScalar    *values;
3692   PetscErrorCode ierr;
3693 
3694   PetscFunctionBegin;
3695   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3696 
3697   ierr   = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3698   ierr   = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3699   m      = B->rmap->n;
3700   cstart = B->cmap->rstart;
3701   cend   = B->cmap->rend;
3702   rstart = B->rmap->rstart;
3703 
3704   ierr = PetscMalloc2(m,&d_nnz,m,&o_nnz);CHKERRQ(ierr);
3705 
3706 #if defined(PETSC_USE_DEBUGGING)
3707   for (i=0; i<m; i++) {
3708     nnz = Ii[i+1]- Ii[i];
3709     JJ  = J + Ii[i];
3710     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3711     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3712     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);
3713   }
3714 #endif
3715 
3716   for (i=0; i<m; i++) {
3717     nnz     = Ii[i+1]- Ii[i];
3718     JJ      = J + Ii[i];
3719     nnz_max = PetscMax(nnz_max,nnz);
3720     d       = 0;
3721     for (j=0; j<nnz; j++) {
3722       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3723     }
3724     d_nnz[i] = d;
3725     o_nnz[i] = nnz - d;
3726   }
3727   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3728   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3729 
3730   if (v) values = (PetscScalar*)v;
3731   else {
3732     ierr = PetscCalloc1((nnz_max+1),&values);CHKERRQ(ierr);
3733   }
3734 
3735   for (i=0; i<m; i++) {
3736     ii   = i + rstart;
3737     nnz  = Ii[i+1]- Ii[i];
3738     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3739   }
3740   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3741   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3742 
3743   if (!v) {
3744     ierr = PetscFree(values);CHKERRQ(ierr);
3745   }
3746   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3747   PetscFunctionReturn(0);
3748 }
3749 
3750 #undef __FUNCT__
3751 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3752 /*@
3753    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3754    (the default parallel PETSc format).
3755 
3756    Collective on MPI_Comm
3757 
3758    Input Parameters:
3759 +  B - the matrix
3760 .  i - the indices into j for the start of each local row (starts with zero)
3761 .  j - the column indices for each local row (starts with zero)
3762 -  v - optional values in the matrix
3763 
3764    Level: developer
3765 
3766    Notes:
3767        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3768      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3769      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3770 
3771        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3772 
3773        The format which is used for the sparse matrix input, is equivalent to a
3774     row-major ordering.. i.e for the following matrix, the input data expected is
3775     as shown:
3776 
3777         1 0 0
3778         2 0 3     P0
3779        -------
3780         4 5 6     P1
3781 
3782      Process0 [P0]: rows_owned=[0,1]
3783         i =  {0,1,3}  [size = nrow+1  = 2+1]
3784         j =  {0,0,2}  [size = nz = 6]
3785         v =  {1,2,3}  [size = nz = 6]
3786 
3787      Process1 [P1]: rows_owned=[2]
3788         i =  {0,3}    [size = nrow+1  = 1+1]
3789         j =  {0,1,2}  [size = nz = 6]
3790         v =  {4,5,6}  [size = nz = 6]
3791 
3792 .keywords: matrix, aij, compressed row, sparse, parallel
3793 
3794 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MPIAIJ,
3795           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3796 @*/
3797 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3798 {
3799   PetscErrorCode ierr;
3800 
3801   PetscFunctionBegin;
3802   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
3803   PetscFunctionReturn(0);
3804 }
3805 
3806 #undef __FUNCT__
3807 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3808 /*@C
3809    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3810    (the default parallel PETSc format).  For good matrix assembly performance
3811    the user should preallocate the matrix storage by setting the parameters
3812    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3813    performance can be increased by more than a factor of 50.
3814 
3815    Collective on MPI_Comm
3816 
3817    Input Parameters:
3818 +  B - the matrix
3819 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3820            (same value is used for all local rows)
3821 .  d_nnz - array containing the number of nonzeros in the various rows of the
3822            DIAGONAL portion of the local submatrix (possibly different for each row)
3823            or NULL, if d_nz is used to specify the nonzero structure.
3824            The size of this array is equal to the number of local rows, i.e 'm'.
3825            For matrices that will be factored, you must leave room for (and set)
3826            the diagonal entry even if it is zero.
3827 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3828            submatrix (same value is used for all local rows).
3829 -  o_nnz - array containing the number of nonzeros in the various rows of the
3830            OFF-DIAGONAL portion of the local submatrix (possibly different for
3831            each row) or NULL, if o_nz is used to specify the nonzero
3832            structure. The size of this array is equal to the number
3833            of local rows, i.e 'm'.
3834 
3835    If the *_nnz parameter is given then the *_nz parameter is ignored
3836 
3837    The AIJ format (also called the Yale sparse matrix format or
3838    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3839    storage.  The stored row and column indices begin with zero.
3840    See Users-Manual: ch_mat for details.
3841 
3842    The parallel matrix is partitioned such that the first m0 rows belong to
3843    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3844    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3845 
3846    The DIAGONAL portion of the local submatrix of a processor can be defined
3847    as the submatrix which is obtained by extraction the part corresponding to
3848    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
3849    first row that belongs to the processor, r2 is the last row belonging to
3850    the this processor, and c1-c2 is range of indices of the local part of a
3851    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
3852    common case of a square matrix, the row and column ranges are the same and
3853    the DIAGONAL part is also square. The remaining portion of the local
3854    submatrix (mxN) constitute the OFF-DIAGONAL portion.
3855 
3856    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3857 
3858    You can call MatGetInfo() to get information on how effective the preallocation was;
3859    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3860    You can also run with the option -info and look for messages with the string
3861    malloc in them to see if additional memory allocation was needed.
3862 
3863    Example usage:
3864 
3865    Consider the following 8x8 matrix with 34 non-zero values, that is
3866    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3867    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3868    as follows:
3869 
3870 .vb
3871             1  2  0  |  0  3  0  |  0  4
3872     Proc0   0  5  6  |  7  0  0  |  8  0
3873             9  0 10  | 11  0  0  | 12  0
3874     -------------------------------------
3875            13  0 14  | 15 16 17  |  0  0
3876     Proc1   0 18  0  | 19 20 21  |  0  0
3877             0  0  0  | 22 23  0  | 24  0
3878     -------------------------------------
3879     Proc2  25 26 27  |  0  0 28  | 29  0
3880            30  0  0  | 31 32 33  |  0 34
3881 .ve
3882 
3883    This can be represented as a collection of submatrices as:
3884 
3885 .vb
3886       A B C
3887       D E F
3888       G H I
3889 .ve
3890 
3891    Where the submatrices A,B,C are owned by proc0, D,E,F are
3892    owned by proc1, G,H,I are owned by proc2.
3893 
3894    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3895    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3896    The 'M','N' parameters are 8,8, and have the same values on all procs.
3897 
3898    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3899    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3900    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3901    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3902    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3903    matrix, ans [DF] as another SeqAIJ matrix.
3904 
3905    When d_nz, o_nz parameters are specified, d_nz storage elements are
3906    allocated for every row of the local diagonal submatrix, and o_nz
3907    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3908    One way to choose d_nz and o_nz is to use the max nonzerors per local
3909    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3910    In this case, the values of d_nz,o_nz are:
3911 .vb
3912      proc0 : dnz = 2, o_nz = 2
3913      proc1 : dnz = 3, o_nz = 2
3914      proc2 : dnz = 1, o_nz = 4
3915 .ve
3916    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3917    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3918    for proc3. i.e we are using 12+15+10=37 storage locations to store
3919    34 values.
3920 
3921    When d_nnz, o_nnz parameters are specified, the storage is specified
3922    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3923    In the above case the values for d_nnz,o_nnz are:
3924 .vb
3925      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3926      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3927      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3928 .ve
3929    Here the space allocated is sum of all the above values i.e 34, and
3930    hence pre-allocation is perfect.
3931 
3932    Level: intermediate
3933 
3934 .keywords: matrix, aij, compressed row, sparse, parallel
3935 
3936 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
3937           MPIAIJ, MatGetInfo(), PetscSplitOwnership()
3938 @*/
3939 PetscErrorCode  MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3940 {
3941   PetscErrorCode ierr;
3942 
3943   PetscFunctionBegin;
3944   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
3945   PetscValidType(B,1);
3946   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
3947   PetscFunctionReturn(0);
3948 }
3949 
3950 #undef __FUNCT__
3951 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3952 /*@
3953      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3954          CSR format the local rows.
3955 
3956    Collective on MPI_Comm
3957 
3958    Input Parameters:
3959 +  comm - MPI communicator
3960 .  m - number of local rows (Cannot be PETSC_DECIDE)
3961 .  n - This value should be the same as the local size used in creating the
3962        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3963        calculated if N is given) For square matrices n is almost always m.
3964 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3965 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3966 .   i - row indices
3967 .   j - column indices
3968 -   a - matrix values
3969 
3970    Output Parameter:
3971 .   mat - the matrix
3972 
3973    Level: intermediate
3974 
3975    Notes:
3976        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3977      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3978      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3979 
3980        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3981 
3982        The format which is used for the sparse matrix input, is equivalent to a
3983     row-major ordering.. i.e for the following matrix, the input data expected is
3984     as shown:
3985 
3986         1 0 0
3987         2 0 3     P0
3988        -------
3989         4 5 6     P1
3990 
3991      Process0 [P0]: rows_owned=[0,1]
3992         i =  {0,1,3}  [size = nrow+1  = 2+1]
3993         j =  {0,0,2}  [size = nz = 6]
3994         v =  {1,2,3}  [size = nz = 6]
3995 
3996      Process1 [P1]: rows_owned=[2]
3997         i =  {0,3}    [size = nrow+1  = 1+1]
3998         j =  {0,1,2}  [size = nz = 6]
3999         v =  {4,5,6}  [size = nz = 6]
4000 
4001 .keywords: matrix, aij, compressed row, sparse, parallel
4002 
4003 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4004           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
4005 @*/
4006 PetscErrorCode  MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
4007 {
4008   PetscErrorCode ierr;
4009 
4010   PetscFunctionBegin;
4011   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
4012   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
4013   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
4014   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
4015   /* ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr); */
4016   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
4017   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
4018   PetscFunctionReturn(0);
4019 }
4020 
4021 #undef __FUNCT__
4022 #define __FUNCT__ "MatCreateAIJ"
4023 /*@C
4024    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
4025    (the default parallel PETSc format).  For good matrix assembly performance
4026    the user should preallocate the matrix storage by setting the parameters
4027    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4028    performance can be increased by more than a factor of 50.
4029 
4030    Collective on MPI_Comm
4031 
4032    Input Parameters:
4033 +  comm - MPI communicator
4034 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
4035            This value should be the same as the local size used in creating the
4036            y vector for the matrix-vector product y = Ax.
4037 .  n - This value should be the same as the local size used in creating the
4038        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4039        calculated if N is given) For square matrices n is almost always m.
4040 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4041 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4042 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4043            (same value is used for all local rows)
4044 .  d_nnz - array containing the number of nonzeros in the various rows of the
4045            DIAGONAL portion of the local submatrix (possibly different for each row)
4046            or NULL, if d_nz is used to specify the nonzero structure.
4047            The size of this array is equal to the number of local rows, i.e 'm'.
4048 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4049            submatrix (same value is used for all local rows).
4050 -  o_nnz - array containing the number of nonzeros in the various rows of the
4051            OFF-DIAGONAL portion of the local submatrix (possibly different for
4052            each row) or NULL, if o_nz is used to specify the nonzero
4053            structure. The size of this array is equal to the number
4054            of local rows, i.e 'm'.
4055 
4056    Output Parameter:
4057 .  A - the matrix
4058 
4059    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
4060    MatXXXXSetPreallocation() paradgm instead of this routine directly.
4061    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
4062 
4063    Notes:
4064    If the *_nnz parameter is given then the *_nz parameter is ignored
4065 
4066    m,n,M,N parameters specify the size of the matrix, and its partitioning across
4067    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
4068    storage requirements for this matrix.
4069 
4070    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
4071    processor than it must be used on all processors that share the object for
4072    that argument.
4073 
4074    The user MUST specify either the local or global matrix dimensions
4075    (possibly both).
4076 
4077    The parallel matrix is partitioned across processors such that the
4078    first m0 rows belong to process 0, the next m1 rows belong to
4079    process 1, the next m2 rows belong to process 2 etc.. where
4080    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
4081    values corresponding to [m x N] submatrix.
4082 
4083    The columns are logically partitioned with the n0 columns belonging
4084    to 0th partition, the next n1 columns belonging to the next
4085    partition etc.. where n0,n1,n2... are the input parameter 'n'.
4086 
4087    The DIAGONAL portion of the local submatrix on any given processor
4088    is the submatrix corresponding to the rows and columns m,n
4089    corresponding to the given processor. i.e diagonal matrix on
4090    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4091    etc. The remaining portion of the local submatrix [m x (N-n)]
4092    constitute the OFF-DIAGONAL portion. The example below better
4093    illustrates this concept.
4094 
4095    For a square global matrix we define each processor's diagonal portion
4096    to be its local rows and the corresponding columns (a square submatrix);
4097    each processor's off-diagonal portion encompasses the remainder of the
4098    local matrix (a rectangular submatrix).
4099 
4100    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4101 
4102    When calling this routine with a single process communicator, a matrix of
4103    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
4104    type of communicator, use the construction mechanism:
4105      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
4106 
4107    By default, this format uses inodes (identical nodes) when possible.
4108    We search for consecutive rows with the same nonzero structure, thereby
4109    reusing matrix information to achieve increased efficiency.
4110 
4111    Options Database Keys:
4112 +  -mat_no_inode  - Do not use inodes
4113 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
4114 -  -mat_aij_oneindex - Internally use indexing starting at 1
4115         rather than 0.  Note that when calling MatSetValues(),
4116         the user still MUST index entries starting at 0!
4117 
4118 
4119    Example usage:
4120 
4121    Consider the following 8x8 matrix with 34 non-zero values, that is
4122    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4123    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4124    as follows:
4125 
4126 .vb
4127             1  2  0  |  0  3  0  |  0  4
4128     Proc0   0  5  6  |  7  0  0  |  8  0
4129             9  0 10  | 11  0  0  | 12  0
4130     -------------------------------------
4131            13  0 14  | 15 16 17  |  0  0
4132     Proc1   0 18  0  | 19 20 21  |  0  0
4133             0  0  0  | 22 23  0  | 24  0
4134     -------------------------------------
4135     Proc2  25 26 27  |  0  0 28  | 29  0
4136            30  0  0  | 31 32 33  |  0 34
4137 .ve
4138 
4139    This can be represented as a collection of submatrices as:
4140 
4141 .vb
4142       A B C
4143       D E F
4144       G H I
4145 .ve
4146 
4147    Where the submatrices A,B,C are owned by proc0, D,E,F are
4148    owned by proc1, G,H,I are owned by proc2.
4149 
4150    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4151    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4152    The 'M','N' parameters are 8,8, and have the same values on all procs.
4153 
4154    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4155    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4156    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4157    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4158    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4159    matrix, ans [DF] as another SeqAIJ matrix.
4160 
4161    When d_nz, o_nz parameters are specified, d_nz storage elements are
4162    allocated for every row of the local diagonal submatrix, and o_nz
4163    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4164    One way to choose d_nz and o_nz is to use the max nonzerors per local
4165    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4166    In this case, the values of d_nz,o_nz are:
4167 .vb
4168      proc0 : dnz = 2, o_nz = 2
4169      proc1 : dnz = 3, o_nz = 2
4170      proc2 : dnz = 1, o_nz = 4
4171 .ve
4172    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4173    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4174    for proc3. i.e we are using 12+15+10=37 storage locations to store
4175    34 values.
4176 
4177    When d_nnz, o_nnz parameters are specified, the storage is specified
4178    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4179    In the above case the values for d_nnz,o_nnz are:
4180 .vb
4181      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4182      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4183      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4184 .ve
4185    Here the space allocated is sum of all the above values i.e 34, and
4186    hence pre-allocation is perfect.
4187 
4188    Level: intermediate
4189 
4190 .keywords: matrix, aij, compressed row, sparse, parallel
4191 
4192 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4193           MPIAIJ, MatCreateMPIAIJWithArrays()
4194 @*/
4195 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)
4196 {
4197   PetscErrorCode ierr;
4198   PetscMPIInt    size;
4199 
4200   PetscFunctionBegin;
4201   ierr = MatCreate(comm,A);CHKERRQ(ierr);
4202   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
4203   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4204   if (size > 1) {
4205     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
4206     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
4207   } else {
4208     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
4209     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
4210   }
4211   PetscFunctionReturn(0);
4212 }
4213 
4214 #undef __FUNCT__
4215 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
4216 PetscErrorCode  MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,const PetscInt *colmap[])
4217 {
4218   Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
4219 
4220   PetscFunctionBegin;
4221   if (Ad)     *Ad     = a->A;
4222   if (Ao)     *Ao     = a->B;
4223   if (colmap) *colmap = a->garray;
4224   PetscFunctionReturn(0);
4225 }
4226 
4227 #undef __FUNCT__
4228 #define __FUNCT__ "MatSetColoring_MPIAIJ"
4229 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
4230 {
4231   PetscErrorCode ierr;
4232   PetscInt       i;
4233   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4234 
4235   PetscFunctionBegin;
4236   if (coloring->ctype == IS_COLORING_GLOBAL) {
4237     ISColoringValue *allcolors,*colors;
4238     ISColoring      ocoloring;
4239 
4240     /* set coloring for diagonal portion */
4241     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
4242 
4243     /* set coloring for off-diagonal portion */
4244     ierr = ISAllGatherColors(PetscObjectComm((PetscObject)A),coloring->n,coloring->colors,NULL,&allcolors);CHKERRQ(ierr);
4245     ierr = PetscMalloc1((a->B->cmap->n+1),&colors);CHKERRQ(ierr);
4246     for (i=0; i<a->B->cmap->n; i++) {
4247       colors[i] = allcolors[a->garray[i]];
4248     }
4249     ierr = PetscFree(allcolors);CHKERRQ(ierr);
4250     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4251     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4252     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4253   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
4254     ISColoringValue *colors;
4255     PetscInt        *larray;
4256     ISColoring      ocoloring;
4257 
4258     /* set coloring for diagonal portion */
4259     ierr = PetscMalloc1((a->A->cmap->n+1),&larray);CHKERRQ(ierr);
4260     for (i=0; i<a->A->cmap->n; i++) {
4261       larray[i] = i + A->cmap->rstart;
4262     }
4263     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,NULL,larray);CHKERRQ(ierr);
4264     ierr = PetscMalloc1((a->A->cmap->n+1),&colors);CHKERRQ(ierr);
4265     for (i=0; i<a->A->cmap->n; i++) {
4266       colors[i] = coloring->colors[larray[i]];
4267     }
4268     ierr = PetscFree(larray);CHKERRQ(ierr);
4269     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4270     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
4271     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4272 
4273     /* set coloring for off-diagonal portion */
4274     ierr = PetscMalloc1((a->B->cmap->n+1),&larray);CHKERRQ(ierr);
4275     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,NULL,larray);CHKERRQ(ierr);
4276     ierr = PetscMalloc1((a->B->cmap->n+1),&colors);CHKERRQ(ierr);
4277     for (i=0; i<a->B->cmap->n; i++) {
4278       colors[i] = coloring->colors[larray[i]];
4279     }
4280     ierr = PetscFree(larray);CHKERRQ(ierr);
4281     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4282     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4283     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4284   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
4285   PetscFunctionReturn(0);
4286 }
4287 
4288 #undef __FUNCT__
4289 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
4290 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
4291 {
4292   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4293   PetscErrorCode ierr;
4294 
4295   PetscFunctionBegin;
4296   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
4297   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
4298   PetscFunctionReturn(0);
4299 }
4300 
4301 #undef __FUNCT__
4302 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJSymbolic"
4303 PetscErrorCode MatCreateMPIAIJConcatenateSeqAIJSymbolic(MPI_Comm comm,Mat inmat,PetscInt n,Mat *outmat)
4304 {
4305   PetscErrorCode ierr;
4306   PetscInt       m,N,i,rstart,nnz,*dnz,*onz,sum,bs,cbs;
4307   PetscInt       *indx;
4308 
4309   PetscFunctionBegin;
4310   /* This routine will ONLY return MPIAIJ type matrix */
4311   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4312   ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
4313   if (n == PETSC_DECIDE) {
4314     ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
4315   }
4316   /* Check sum(n) = N */
4317   ierr = MPI_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4318   if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
4319 
4320   ierr    = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4321   rstart -= m;
4322 
4323   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4324   for (i=0; i<m; i++) {
4325     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4326     ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
4327     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4328   }
4329 
4330   ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
4331   ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4332   ierr = MatSetBlockSizes(*outmat,bs,cbs);CHKERRQ(ierr);
4333   ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
4334   ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
4335   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4336   PetscFunctionReturn(0);
4337 }
4338 
4339 #undef __FUNCT__
4340 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJNumeric"
4341 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJNumeric(MPI_Comm comm,Mat inmat,PetscInt n,Mat outmat)
4342 {
4343   PetscErrorCode ierr;
4344   PetscInt       m,N,i,rstart,nnz,Ii;
4345   PetscInt       *indx;
4346   PetscScalar    *values;
4347 
4348   PetscFunctionBegin;
4349   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4350   ierr = MatGetOwnershipRange(outmat,&rstart,NULL);CHKERRQ(ierr);
4351   for (i=0; i<m; i++) {
4352     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4353     Ii   = i + rstart;
4354     ierr = MatSetValues(outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4355     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4356   }
4357   ierr = MatAssemblyBegin(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4358   ierr = MatAssemblyEnd(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4359   PetscFunctionReturn(0);
4360 }
4361 
4362 #undef __FUNCT__
4363 #define __FUNCT__ "MatCreateMPIMatConcatenateSeqMat_MPIAIJ"
4364 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_MPIAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
4365 {
4366   PetscErrorCode ierr;
4367   PetscMPIInt    size;
4368 
4369   PetscFunctionBegin;
4370   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4371   ierr = PetscLogEventBegin(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4372   if (size == 1) {
4373     if (scall == MAT_INITIAL_MATRIX) {
4374       ierr = MatDuplicate(inmat,MAT_COPY_VALUES,outmat);CHKERRQ(ierr);
4375     } else {
4376       ierr = MatCopy(inmat,*outmat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4377     }
4378   } else {
4379     if (scall == MAT_INITIAL_MATRIX) {
4380       ierr = MatCreateMPIAIJConcatenateSeqAIJSymbolic(comm,inmat,n,outmat);CHKERRQ(ierr);
4381     }
4382     ierr = MatCreateMPIAIJConcatenateSeqAIJNumeric(comm,inmat,n,*outmat);CHKERRQ(ierr);
4383   }
4384   ierr = PetscLogEventEnd(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4385   PetscFunctionReturn(0);
4386 }
4387 
4388 #undef __FUNCT__
4389 #define __FUNCT__ "MatFileSplit"
4390 PetscErrorCode MatFileSplit(Mat A,char *outfile)
4391 {
4392   PetscErrorCode    ierr;
4393   PetscMPIInt       rank;
4394   PetscInt          m,N,i,rstart,nnz;
4395   size_t            len;
4396   const PetscInt    *indx;
4397   PetscViewer       out;
4398   char              *name;
4399   Mat               B;
4400   const PetscScalar *values;
4401 
4402   PetscFunctionBegin;
4403   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
4404   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
4405   /* Should this be the type of the diagonal block of A? */
4406   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
4407   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
4408   ierr = MatSetBlockSizesFromMats(B,A,A);CHKERRQ(ierr);
4409   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
4410   ierr = MatSeqAIJSetPreallocation(B,0,NULL);CHKERRQ(ierr);
4411   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
4412   for (i=0; i<m; i++) {
4413     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4414     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4415     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4416   }
4417   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4418   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4419 
4420   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
4421   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
4422   ierr = PetscMalloc1((len+5),&name);CHKERRQ(ierr);
4423   sprintf(name,"%s.%d",outfile,rank);
4424   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
4425   ierr = PetscFree(name);CHKERRQ(ierr);
4426   ierr = MatView(B,out);CHKERRQ(ierr);
4427   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
4428   ierr = MatDestroy(&B);CHKERRQ(ierr);
4429   PetscFunctionReturn(0);
4430 }
4431 
4432 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
4433 #undef __FUNCT__
4434 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
4435 PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
4436 {
4437   PetscErrorCode      ierr;
4438   Mat_Merge_SeqsToMPI *merge;
4439   PetscContainer      container;
4440 
4441   PetscFunctionBegin;
4442   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4443   if (container) {
4444     ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4445     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
4446     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
4447     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
4448     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
4449     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
4450     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
4451     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
4452     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
4453     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
4454     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
4455     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
4456     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
4457     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
4458     ierr = PetscFree(merge);CHKERRQ(ierr);
4459     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
4460   }
4461   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
4462   PetscFunctionReturn(0);
4463 }
4464 
4465 #include <../src/mat/utils/freespace.h>
4466 #include <petscbt.h>
4467 
4468 #undef __FUNCT__
4469 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJNumeric"
4470 PetscErrorCode  MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
4471 {
4472   PetscErrorCode      ierr;
4473   MPI_Comm            comm;
4474   Mat_SeqAIJ          *a  =(Mat_SeqAIJ*)seqmat->data;
4475   PetscMPIInt         size,rank,taga,*len_s;
4476   PetscInt            N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj;
4477   PetscInt            proc,m;
4478   PetscInt            **buf_ri,**buf_rj;
4479   PetscInt            k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
4480   PetscInt            nrows,**buf_ri_k,**nextrow,**nextai;
4481   MPI_Request         *s_waits,*r_waits;
4482   MPI_Status          *status;
4483   MatScalar           *aa=a->a;
4484   MatScalar           **abuf_r,*ba_i;
4485   Mat_Merge_SeqsToMPI *merge;
4486   PetscContainer      container;
4487 
4488   PetscFunctionBegin;
4489   ierr = PetscObjectGetComm((PetscObject)mpimat,&comm);CHKERRQ(ierr);
4490   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4491 
4492   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4493   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4494 
4495   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4496   ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4497 
4498   bi     = merge->bi;
4499   bj     = merge->bj;
4500   buf_ri = merge->buf_ri;
4501   buf_rj = merge->buf_rj;
4502 
4503   ierr   = PetscMalloc1(size,&status);CHKERRQ(ierr);
4504   owners = merge->rowmap->range;
4505   len_s  = merge->len_s;
4506 
4507   /* send and recv matrix values */
4508   /*-----------------------------*/
4509   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
4510   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
4511 
4512   ierr = PetscMalloc1((merge->nsend+1),&s_waits);CHKERRQ(ierr);
4513   for (proc=0,k=0; proc<size; proc++) {
4514     if (!len_s[proc]) continue;
4515     i    = owners[proc];
4516     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4517     k++;
4518   }
4519 
4520   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4521   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4522   ierr = PetscFree(status);CHKERRQ(ierr);
4523 
4524   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4525   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4526 
4527   /* insert mat values of mpimat */
4528   /*----------------------------*/
4529   ierr = PetscMalloc1(N,&ba_i);CHKERRQ(ierr);
4530   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4531 
4532   for (k=0; k<merge->nrecv; k++) {
4533     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4534     nrows       = *(buf_ri_k[k]);
4535     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4536     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4537   }
4538 
4539   /* set values of ba */
4540   m = merge->rowmap->n;
4541   for (i=0; i<m; i++) {
4542     arow = owners[rank] + i;
4543     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4544     bnzi = bi[i+1] - bi[i];
4545     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4546 
4547     /* add local non-zero vals of this proc's seqmat into ba */
4548     anzi   = ai[arow+1] - ai[arow];
4549     aj     = a->j + ai[arow];
4550     aa     = a->a + ai[arow];
4551     nextaj = 0;
4552     for (j=0; nextaj<anzi; j++) {
4553       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4554         ba_i[j] += aa[nextaj++];
4555       }
4556     }
4557 
4558     /* add received vals into ba */
4559     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4560       /* i-th row */
4561       if (i == *nextrow[k]) {
4562         anzi   = *(nextai[k]+1) - *nextai[k];
4563         aj     = buf_rj[k] + *(nextai[k]);
4564         aa     = abuf_r[k] + *(nextai[k]);
4565         nextaj = 0;
4566         for (j=0; nextaj<anzi; j++) {
4567           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4568             ba_i[j] += aa[nextaj++];
4569           }
4570         }
4571         nextrow[k]++; nextai[k]++;
4572       }
4573     }
4574     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4575   }
4576   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4577   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4578 
4579   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4580   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4581   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4582   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4583   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4584   PetscFunctionReturn(0);
4585 }
4586 
4587 extern PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat);
4588 
4589 #undef __FUNCT__
4590 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJSymbolic"
4591 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4592 {
4593   PetscErrorCode      ierr;
4594   Mat                 B_mpi;
4595   Mat_SeqAIJ          *a=(Mat_SeqAIJ*)seqmat->data;
4596   PetscMPIInt         size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4597   PetscInt            **buf_rj,**buf_ri,**buf_ri_k;
4598   PetscInt            M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4599   PetscInt            len,proc,*dnz,*onz,bs,cbs;
4600   PetscInt            k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4601   PetscInt            nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4602   MPI_Request         *si_waits,*sj_waits,*ri_waits,*rj_waits;
4603   MPI_Status          *status;
4604   PetscFreeSpaceList  free_space=NULL,current_space=NULL;
4605   PetscBT             lnkbt;
4606   Mat_Merge_SeqsToMPI *merge;
4607   PetscContainer      container;
4608 
4609   PetscFunctionBegin;
4610   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4611 
4612   /* make sure it is a PETSc comm */
4613   ierr = PetscCommDuplicate(comm,&comm,NULL);CHKERRQ(ierr);
4614   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4615   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4616 
4617   ierr = PetscNew(&merge);CHKERRQ(ierr);
4618   ierr = PetscMalloc1(size,&status);CHKERRQ(ierr);
4619 
4620   /* determine row ownership */
4621   /*---------------------------------------------------------*/
4622   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4623   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4624   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4625   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4626   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4627   ierr = PetscMalloc1(size,&len_si);CHKERRQ(ierr);
4628   ierr = PetscMalloc1(size,&merge->len_s);CHKERRQ(ierr);
4629 
4630   m      = merge->rowmap->n;
4631   owners = merge->rowmap->range;
4632 
4633   /* determine the number of messages to send, their lengths */
4634   /*---------------------------------------------------------*/
4635   len_s = merge->len_s;
4636 
4637   len          = 0; /* length of buf_si[] */
4638   merge->nsend = 0;
4639   for (proc=0; proc<size; proc++) {
4640     len_si[proc] = 0;
4641     if (proc == rank) {
4642       len_s[proc] = 0;
4643     } else {
4644       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4645       len_s[proc]  = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4646     }
4647     if (len_s[proc]) {
4648       merge->nsend++;
4649       nrows = 0;
4650       for (i=owners[proc]; i<owners[proc+1]; i++) {
4651         if (ai[i+1] > ai[i]) nrows++;
4652       }
4653       len_si[proc] = 2*(nrows+1);
4654       len         += len_si[proc];
4655     }
4656   }
4657 
4658   /* determine the number and length of messages to receive for ij-structure */
4659   /*-------------------------------------------------------------------------*/
4660   ierr = PetscGatherNumberOfMessages(comm,NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4661   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4662 
4663   /* post the Irecv of j-structure */
4664   /*-------------------------------*/
4665   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4666   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4667 
4668   /* post the Isend of j-structure */
4669   /*--------------------------------*/
4670   ierr = PetscMalloc2(merge->nsend,&si_waits,merge->nsend,&sj_waits);CHKERRQ(ierr);
4671 
4672   for (proc=0, k=0; proc<size; proc++) {
4673     if (!len_s[proc]) continue;
4674     i    = owners[proc];
4675     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4676     k++;
4677   }
4678 
4679   /* receives and sends of j-structure are complete */
4680   /*------------------------------------------------*/
4681   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4682   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4683 
4684   /* send and recv i-structure */
4685   /*---------------------------*/
4686   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4687   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4688 
4689   ierr   = PetscMalloc1((len+1),&buf_s);CHKERRQ(ierr);
4690   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4691   for (proc=0,k=0; proc<size; proc++) {
4692     if (!len_s[proc]) continue;
4693     /* form outgoing message for i-structure:
4694          buf_si[0]:                 nrows to be sent
4695                [1:nrows]:           row index (global)
4696                [nrows+1:2*nrows+1]: i-structure index
4697     */
4698     /*-------------------------------------------*/
4699     nrows       = len_si[proc]/2 - 1;
4700     buf_si_i    = buf_si + nrows+1;
4701     buf_si[0]   = nrows;
4702     buf_si_i[0] = 0;
4703     nrows       = 0;
4704     for (i=owners[proc]; i<owners[proc+1]; i++) {
4705       anzi = ai[i+1] - ai[i];
4706       if (anzi) {
4707         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4708         buf_si[nrows+1]   = i-owners[proc]; /* local row index */
4709         nrows++;
4710       }
4711     }
4712     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4713     k++;
4714     buf_si += len_si[proc];
4715   }
4716 
4717   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4718   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4719 
4720   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4721   for (i=0; i<merge->nrecv; i++) {
4722     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);
4723   }
4724 
4725   ierr = PetscFree(len_si);CHKERRQ(ierr);
4726   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4727   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4728   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4729   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4730   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4731   ierr = PetscFree(status);CHKERRQ(ierr);
4732 
4733   /* compute a local seq matrix in each processor */
4734   /*----------------------------------------------*/
4735   /* allocate bi array and free space for accumulating nonzero column info */
4736   ierr  = PetscMalloc1((m+1),&bi);CHKERRQ(ierr);
4737   bi[0] = 0;
4738 
4739   /* create and initialize a linked list */
4740   nlnk = N+1;
4741   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4742 
4743   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4744   len  = ai[owners[rank+1]] - ai[owners[rank]];
4745   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4746 
4747   current_space = free_space;
4748 
4749   /* determine symbolic info for each local row */
4750   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4751 
4752   for (k=0; k<merge->nrecv; k++) {
4753     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4754     nrows       = *buf_ri_k[k];
4755     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4756     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4757   }
4758 
4759   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4760   len  = 0;
4761   for (i=0; i<m; i++) {
4762     bnzi = 0;
4763     /* add local non-zero cols of this proc's seqmat into lnk */
4764     arow  = owners[rank] + i;
4765     anzi  = ai[arow+1] - ai[arow];
4766     aj    = a->j + ai[arow];
4767     ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4768     bnzi += nlnk;
4769     /* add received col data into lnk */
4770     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4771       if (i == *nextrow[k]) { /* i-th row */
4772         anzi  = *(nextai[k]+1) - *nextai[k];
4773         aj    = buf_rj[k] + *nextai[k];
4774         ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4775         bnzi += nlnk;
4776         nextrow[k]++; nextai[k]++;
4777       }
4778     }
4779     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4780 
4781     /* if free space is not available, make more free space */
4782     if (current_space->local_remaining<bnzi) {
4783       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4784       nspacedouble++;
4785     }
4786     /* copy data into free space, then initialize lnk */
4787     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4788     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4789 
4790     current_space->array           += bnzi;
4791     current_space->local_used      += bnzi;
4792     current_space->local_remaining -= bnzi;
4793 
4794     bi[i+1] = bi[i] + bnzi;
4795   }
4796 
4797   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4798 
4799   ierr = PetscMalloc1((bi[m]+1),&bj);CHKERRQ(ierr);
4800   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4801   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4802 
4803   /* create symbolic parallel matrix B_mpi */
4804   /*---------------------------------------*/
4805   ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
4806   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4807   if (n==PETSC_DECIDE) {
4808     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4809   } else {
4810     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4811   }
4812   ierr = MatSetBlockSizes(B_mpi,bs,cbs);CHKERRQ(ierr);
4813   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4814   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4815   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4816   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
4817 
4818   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
4819   B_mpi->assembled    = PETSC_FALSE;
4820   B_mpi->ops->destroy = MatDestroy_MPIAIJ_SeqsToMPI;
4821   merge->bi           = bi;
4822   merge->bj           = bj;
4823   merge->buf_ri       = buf_ri;
4824   merge->buf_rj       = buf_rj;
4825   merge->coi          = NULL;
4826   merge->coj          = NULL;
4827   merge->owners_co    = NULL;
4828 
4829   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4830 
4831   /* attach the supporting struct to B_mpi for reuse */
4832   ierr    = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4833   ierr    = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4834   ierr    = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4835   ierr    = PetscContainerDestroy(&container);CHKERRQ(ierr);
4836   *mpimat = B_mpi;
4837 
4838   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4839   PetscFunctionReturn(0);
4840 }
4841 
4842 #undef __FUNCT__
4843 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJ"
4844 /*@C
4845       MatCreateMPIAIJSumSeqAIJ - Creates a MPIAIJ matrix by adding sequential
4846                  matrices from each processor
4847 
4848     Collective on MPI_Comm
4849 
4850    Input Parameters:
4851 +    comm - the communicators the parallel matrix will live on
4852 .    seqmat - the input sequential matrices
4853 .    m - number of local rows (or PETSC_DECIDE)
4854 .    n - number of local columns (or PETSC_DECIDE)
4855 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4856 
4857    Output Parameter:
4858 .    mpimat - the parallel matrix generated
4859 
4860     Level: advanced
4861 
4862    Notes:
4863      The dimensions of the sequential matrix in each processor MUST be the same.
4864      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
4865      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
4866 @*/
4867 PetscErrorCode  MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4868 {
4869   PetscErrorCode ierr;
4870   PetscMPIInt    size;
4871 
4872   PetscFunctionBegin;
4873   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4874   if (size == 1) {
4875     ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4876     if (scall == MAT_INITIAL_MATRIX) {
4877       ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
4878     } else {
4879       ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4880     }
4881     ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4882     PetscFunctionReturn(0);
4883   }
4884   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4885   if (scall == MAT_INITIAL_MATRIX) {
4886     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4887   }
4888   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
4889   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4890   PetscFunctionReturn(0);
4891 }
4892 
4893 #undef __FUNCT__
4894 #define __FUNCT__ "MatMPIAIJGetLocalMat"
4895 /*@
4896      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
4897           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
4898           with MatGetSize()
4899 
4900     Not Collective
4901 
4902    Input Parameters:
4903 +    A - the matrix
4904 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4905 
4906    Output Parameter:
4907 .    A_loc - the local sequential matrix generated
4908 
4909     Level: developer
4910 
4911 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
4912 
4913 @*/
4914 PetscErrorCode  MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4915 {
4916   PetscErrorCode ierr;
4917   Mat_MPIAIJ     *mpimat=(Mat_MPIAIJ*)A->data;
4918   Mat_SeqAIJ     *mat,*a,*b;
4919   PetscInt       *ai,*aj,*bi,*bj,*cmap=mpimat->garray;
4920   MatScalar      *aa,*ba,*cam;
4921   PetscScalar    *ca;
4922   PetscInt       am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4923   PetscInt       *ci,*cj,col,ncols_d,ncols_o,jo;
4924   PetscBool      match;
4925   MPI_Comm       comm;
4926   PetscMPIInt    size;
4927 
4928   PetscFunctionBegin;
4929   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4930   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
4931   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
4932   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4933   if (size == 1 && scall == MAT_REUSE_MATRIX) PetscFunctionReturn(0);
4934 
4935   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4936   a = (Mat_SeqAIJ*)(mpimat->A)->data;
4937   b = (Mat_SeqAIJ*)(mpimat->B)->data;
4938   ai = a->i; aj = a->j; bi = b->i; bj = b->j;
4939   aa = a->a; ba = b->a;
4940   if (scall == MAT_INITIAL_MATRIX) {
4941     if (size == 1) {
4942       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ai,aj,aa,A_loc);CHKERRQ(ierr);
4943       PetscFunctionReturn(0);
4944     }
4945 
4946     ierr  = PetscMalloc1((1+am),&ci);CHKERRQ(ierr);
4947     ci[0] = 0;
4948     for (i=0; i<am; i++) {
4949       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4950     }
4951     ierr = PetscMalloc1((1+ci[am]),&cj);CHKERRQ(ierr);
4952     ierr = PetscMalloc1((1+ci[am]),&ca);CHKERRQ(ierr);
4953     k    = 0;
4954     for (i=0; i<am; i++) {
4955       ncols_o = bi[i+1] - bi[i];
4956       ncols_d = ai[i+1] - ai[i];
4957       /* off-diagonal portion of A */
4958       for (jo=0; jo<ncols_o; jo++) {
4959         col = cmap[*bj];
4960         if (col >= cstart) break;
4961         cj[k]   = col; bj++;
4962         ca[k++] = *ba++;
4963       }
4964       /* diagonal portion of A */
4965       for (j=0; j<ncols_d; j++) {
4966         cj[k]   = cstart + *aj++;
4967         ca[k++] = *aa++;
4968       }
4969       /* off-diagonal portion of A */
4970       for (j=jo; j<ncols_o; j++) {
4971         cj[k]   = cmap[*bj++];
4972         ca[k++] = *ba++;
4973       }
4974     }
4975     /* put together the new matrix */
4976     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4977     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4978     /* Since these are PETSc arrays, change flags to free them as necessary. */
4979     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4980     mat->free_a  = PETSC_TRUE;
4981     mat->free_ij = PETSC_TRUE;
4982     mat->nonew   = 0;
4983   } else if (scall == MAT_REUSE_MATRIX) {
4984     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4985     ci = mat->i; cj = mat->j; cam = mat->a;
4986     for (i=0; i<am; i++) {
4987       /* off-diagonal portion of A */
4988       ncols_o = bi[i+1] - bi[i];
4989       for (jo=0; jo<ncols_o; jo++) {
4990         col = cmap[*bj];
4991         if (col >= cstart) break;
4992         *cam++ = *ba++; bj++;
4993       }
4994       /* diagonal portion of A */
4995       ncols_d = ai[i+1] - ai[i];
4996       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4997       /* off-diagonal portion of A */
4998       for (j=jo; j<ncols_o; j++) {
4999         *cam++ = *ba++; bj++;
5000       }
5001     }
5002   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
5003   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
5004   PetscFunctionReturn(0);
5005 }
5006 
5007 #undef __FUNCT__
5008 #define __FUNCT__ "MatMPIAIJGetLocalMatCondensed"
5009 /*@C
5010      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MPIAIJ matrix by taking all its local rows and NON-ZERO columns
5011 
5012     Not Collective
5013 
5014    Input Parameters:
5015 +    A - the matrix
5016 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5017 -    row, col - index sets of rows and columns to extract (or NULL)
5018 
5019    Output Parameter:
5020 .    A_loc - the local sequential matrix generated
5021 
5022     Level: developer
5023 
5024 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
5025 
5026 @*/
5027 PetscErrorCode  MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
5028 {
5029   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5030   PetscErrorCode ierr;
5031   PetscInt       i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
5032   IS             isrowa,iscola;
5033   Mat            *aloc;
5034   PetscBool      match;
5035 
5036   PetscFunctionBegin;
5037   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
5038   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
5039   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5040   if (!row) {
5041     start = A->rmap->rstart; end = A->rmap->rend;
5042     ierr  = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
5043   } else {
5044     isrowa = *row;
5045   }
5046   if (!col) {
5047     start = A->cmap->rstart;
5048     cmap  = a->garray;
5049     nzA   = a->A->cmap->n;
5050     nzB   = a->B->cmap->n;
5051     ierr  = PetscMalloc1((nzA+nzB), &idx);CHKERRQ(ierr);
5052     ncols = 0;
5053     for (i=0; i<nzB; i++) {
5054       if (cmap[i] < start) idx[ncols++] = cmap[i];
5055       else break;
5056     }
5057     imark = i;
5058     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
5059     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
5060     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
5061   } else {
5062     iscola = *col;
5063   }
5064   if (scall != MAT_INITIAL_MATRIX) {
5065     ierr    = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
5066     aloc[0] = *A_loc;
5067   }
5068   ierr   = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
5069   *A_loc = aloc[0];
5070   ierr   = PetscFree(aloc);CHKERRQ(ierr);
5071   if (!row) {
5072     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
5073   }
5074   if (!col) {
5075     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
5076   }
5077   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5078   PetscFunctionReturn(0);
5079 }
5080 
5081 #undef __FUNCT__
5082 #define __FUNCT__ "MatGetBrowsOfAcols"
5083 /*@C
5084     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
5085 
5086     Collective on Mat
5087 
5088    Input Parameters:
5089 +    A,B - the matrices in mpiaij format
5090 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5091 -    rowb, colb - index sets of rows and columns of B to extract (or NULL)
5092 
5093    Output Parameter:
5094 +    rowb, colb - index sets of rows and columns of B to extract
5095 -    B_seq - the sequential matrix generated
5096 
5097     Level: developer
5098 
5099 @*/
5100 PetscErrorCode  MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
5101 {
5102   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5103   PetscErrorCode ierr;
5104   PetscInt       *idx,i,start,ncols,nzA,nzB,*cmap,imark;
5105   IS             isrowb,iscolb;
5106   Mat            *bseq=NULL;
5107 
5108   PetscFunctionBegin;
5109   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5110     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);
5111   }
5112   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5113 
5114   if (scall == MAT_INITIAL_MATRIX) {
5115     start = A->cmap->rstart;
5116     cmap  = a->garray;
5117     nzA   = a->A->cmap->n;
5118     nzB   = a->B->cmap->n;
5119     ierr  = PetscMalloc1((nzA+nzB), &idx);CHKERRQ(ierr);
5120     ncols = 0;
5121     for (i=0; i<nzB; i++) {  /* row < local row index */
5122       if (cmap[i] < start) idx[ncols++] = cmap[i];
5123       else break;
5124     }
5125     imark = i;
5126     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
5127     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5128     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
5129     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
5130   } else {
5131     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5132     isrowb  = *rowb; iscolb = *colb;
5133     ierr    = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
5134     bseq[0] = *B_seq;
5135   }
5136   ierr   = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
5137   *B_seq = bseq[0];
5138   ierr   = PetscFree(bseq);CHKERRQ(ierr);
5139   if (!rowb) {
5140     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
5141   } else {
5142     *rowb = isrowb;
5143   }
5144   if (!colb) {
5145     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
5146   } else {
5147     *colb = iscolb;
5148   }
5149   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5150   PetscFunctionReturn(0);
5151 }
5152 
5153 #undef __FUNCT__
5154 #define __FUNCT__ "MatGetBrowsOfAoCols_MPIAIJ"
5155 /*
5156     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
5157     of the OFF-DIAGONAL portion of local A
5158 
5159     Collective on Mat
5160 
5161    Input Parameters:
5162 +    A,B - the matrices in mpiaij format
5163 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5164 
5165    Output Parameter:
5166 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
5167 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
5168 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
5169 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
5170 
5171     Level: developer
5172 
5173 */
5174 PetscErrorCode  MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
5175 {
5176   VecScatter_MPI_General *gen_to,*gen_from;
5177   PetscErrorCode         ierr;
5178   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
5179   Mat_SeqAIJ             *b_oth;
5180   VecScatter             ctx =a->Mvctx;
5181   MPI_Comm               comm;
5182   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
5183   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
5184   PetscScalar            *rvalues,*svalues;
5185   MatScalar              *b_otha,*bufa,*bufA;
5186   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
5187   MPI_Request            *rwaits = NULL,*swaits = NULL;
5188   MPI_Status             *sstatus,rstatus;
5189   PetscMPIInt            jj,size;
5190   PetscInt               *cols,sbs,rbs;
5191   PetscScalar            *vals;
5192 
5193   PetscFunctionBegin;
5194   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
5195   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
5196   if (size == 1) PetscFunctionReturn(0);
5197 
5198   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5199     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);
5200   }
5201   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5202   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
5203 
5204   gen_to   = (VecScatter_MPI_General*)ctx->todata;
5205   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
5206   rvalues  = gen_from->values; /* holds the length of receiving row */
5207   svalues  = gen_to->values;   /* holds the length of sending row */
5208   nrecvs   = gen_from->n;
5209   nsends   = gen_to->n;
5210 
5211   ierr    = PetscMalloc2(nrecvs,&rwaits,nsends,&swaits);CHKERRQ(ierr);
5212   srow    = gen_to->indices;    /* local row index to be sent */
5213   sstarts = gen_to->starts;
5214   sprocs  = gen_to->procs;
5215   sstatus = gen_to->sstatus;
5216   sbs     = gen_to->bs;
5217   rstarts = gen_from->starts;
5218   rprocs  = gen_from->procs;
5219   rbs     = gen_from->bs;
5220 
5221   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5222   if (scall == MAT_INITIAL_MATRIX) {
5223     /* i-array */
5224     /*---------*/
5225     /*  post receives */
5226     for (i=0; i<nrecvs; i++) {
5227       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5228       nrows  = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
5229       ierr   = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5230     }
5231 
5232     /* pack the outgoing message */
5233     ierr = PetscMalloc2(nsends+1,&sstartsj,nrecvs+1,&rstartsj);CHKERRQ(ierr);
5234 
5235     sstartsj[0] = 0;
5236     rstartsj[0] = 0;
5237     len         = 0; /* total length of j or a array to be sent */
5238     k           = 0;
5239     for (i=0; i<nsends; i++) {
5240       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
5241       nrows  = sstarts[i+1]-sstarts[i]; /* num of block rows */
5242       for (j=0; j<nrows; j++) {
5243         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5244         for (l=0; l<sbs; l++) {
5245           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr); /* rowlength */
5246 
5247           rowlen[j*sbs+l] = ncols;
5248 
5249           len += ncols;
5250           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr);
5251         }
5252         k++;
5253       }
5254       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5255 
5256       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5257     }
5258     /* recvs and sends of i-array are completed */
5259     i = nrecvs;
5260     while (i--) {
5261       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5262     }
5263     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5264 
5265     /* allocate buffers for sending j and a arrays */
5266     ierr = PetscMalloc1((len+1),&bufj);CHKERRQ(ierr);
5267     ierr = PetscMalloc1((len+1),&bufa);CHKERRQ(ierr);
5268 
5269     /* create i-array of B_oth */
5270     ierr = PetscMalloc1((aBn+2),&b_othi);CHKERRQ(ierr);
5271 
5272     b_othi[0] = 0;
5273     len       = 0; /* total length of j or a array to be received */
5274     k         = 0;
5275     for (i=0; i<nrecvs; i++) {
5276       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5277       nrows  = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
5278       for (j=0; j<nrows; j++) {
5279         b_othi[k+1] = b_othi[k] + rowlen[j];
5280         len        += rowlen[j]; k++;
5281       }
5282       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5283     }
5284 
5285     /* allocate space for j and a arrrays of B_oth */
5286     ierr = PetscMalloc1((b_othi[aBn]+1),&b_othj);CHKERRQ(ierr);
5287     ierr = PetscMalloc1((b_othi[aBn]+1),&b_otha);CHKERRQ(ierr);
5288 
5289     /* j-array */
5290     /*---------*/
5291     /*  post receives of j-array */
5292     for (i=0; i<nrecvs; i++) {
5293       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5294       ierr  = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5295     }
5296 
5297     /* pack the outgoing message j-array */
5298     k = 0;
5299     for (i=0; i<nsends; i++) {
5300       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5301       bufJ  = bufj+sstartsj[i];
5302       for (j=0; j<nrows; j++) {
5303         row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5304         for (ll=0; ll<sbs; ll++) {
5305           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5306           for (l=0; l<ncols; l++) {
5307             *bufJ++ = cols[l];
5308           }
5309           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5310         }
5311       }
5312       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5313     }
5314 
5315     /* recvs and sends of j-array are completed */
5316     i = nrecvs;
5317     while (i--) {
5318       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5319     }
5320     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5321   } else if (scall == MAT_REUSE_MATRIX) {
5322     sstartsj = *startsj_s;
5323     rstartsj = *startsj_r;
5324     bufa     = *bufa_ptr;
5325     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
5326     b_otha   = b_oth->a;
5327   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
5328 
5329   /* a-array */
5330   /*---------*/
5331   /*  post receives of a-array */
5332   for (i=0; i<nrecvs; i++) {
5333     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5334     ierr  = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5335   }
5336 
5337   /* pack the outgoing message a-array */
5338   k = 0;
5339   for (i=0; i<nsends; i++) {
5340     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5341     bufA  = bufa+sstartsj[i];
5342     for (j=0; j<nrows; j++) {
5343       row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5344       for (ll=0; ll<sbs; ll++) {
5345         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5346         for (l=0; l<ncols; l++) {
5347           *bufA++ = vals[l];
5348         }
5349         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5350       }
5351     }
5352     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5353   }
5354   /* recvs and sends of a-array are completed */
5355   i = nrecvs;
5356   while (i--) {
5357     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5358   }
5359   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5360   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
5361 
5362   if (scall == MAT_INITIAL_MATRIX) {
5363     /* put together the new matrix */
5364     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
5365 
5366     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5367     /* Since these are PETSc arrays, change flags to free them as necessary. */
5368     b_oth          = (Mat_SeqAIJ*)(*B_oth)->data;
5369     b_oth->free_a  = PETSC_TRUE;
5370     b_oth->free_ij = PETSC_TRUE;
5371     b_oth->nonew   = 0;
5372 
5373     ierr = PetscFree(bufj);CHKERRQ(ierr);
5374     if (!startsj_s || !bufa_ptr) {
5375       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
5376       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
5377     } else {
5378       *startsj_s = sstartsj;
5379       *startsj_r = rstartsj;
5380       *bufa_ptr  = bufa;
5381     }
5382   }
5383   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5384   PetscFunctionReturn(0);
5385 }
5386 
5387 #undef __FUNCT__
5388 #define __FUNCT__ "MatGetCommunicationStructs"
5389 /*@C
5390   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
5391 
5392   Not Collective
5393 
5394   Input Parameters:
5395 . A - The matrix in mpiaij format
5396 
5397   Output Parameter:
5398 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
5399 . colmap - A map from global column index to local index into lvec
5400 - multScatter - A scatter from the argument of a matrix-vector product to lvec
5401 
5402   Level: developer
5403 
5404 @*/
5405 #if defined(PETSC_USE_CTABLE)
5406 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
5407 #else
5408 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
5409 #endif
5410 {
5411   Mat_MPIAIJ *a;
5412 
5413   PetscFunctionBegin;
5414   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
5415   PetscValidPointer(lvec, 2);
5416   PetscValidPointer(colmap, 3);
5417   PetscValidPointer(multScatter, 4);
5418   a = (Mat_MPIAIJ*) A->data;
5419   if (lvec) *lvec = a->lvec;
5420   if (colmap) *colmap = a->colmap;
5421   if (multScatter) *multScatter = a->Mvctx;
5422   PetscFunctionReturn(0);
5423 }
5424 
5425 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat,MatType,MatReuse,Mat*);
5426 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat,MatType,MatReuse,Mat*);
5427 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat,MatType,MatReuse,Mat*);
5428 #if defined(PETSC_HAVE_ELEMENTAL)
5429 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat,MatType,MatReuse,Mat*);
5430 #endif
5431 
5432 #undef __FUNCT__
5433 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
5434 /*
5435     Computes (B'*A')' since computing B*A directly is untenable
5436 
5437                n                       p                          p
5438         (              )       (              )         (                  )
5439       m (      A       )  *  n (       B      )   =   m (         C        )
5440         (              )       (              )         (                  )
5441 
5442 */
5443 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
5444 {
5445   PetscErrorCode ierr;
5446   Mat            At,Bt,Ct;
5447 
5448   PetscFunctionBegin;
5449   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
5450   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
5451   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
5452   ierr = MatDestroy(&At);CHKERRQ(ierr);
5453   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
5454   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
5455   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
5456   PetscFunctionReturn(0);
5457 }
5458 
5459 #undef __FUNCT__
5460 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
5461 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
5462 {
5463   PetscErrorCode ierr;
5464   PetscInt       m=A->rmap->n,n=B->cmap->n;
5465   Mat            Cmat;
5466 
5467   PetscFunctionBegin;
5468   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);
5469   ierr = MatCreate(PetscObjectComm((PetscObject)A),&Cmat);CHKERRQ(ierr);
5470   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5471   ierr = MatSetBlockSizesFromMats(Cmat,A,B);CHKERRQ(ierr);
5472   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
5473   ierr = MatMPIDenseSetPreallocation(Cmat,NULL);CHKERRQ(ierr);
5474   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5475   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5476 
5477   Cmat->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
5478 
5479   *C = Cmat;
5480   PetscFunctionReturn(0);
5481 }
5482 
5483 /* ----------------------------------------------------------------*/
5484 #undef __FUNCT__
5485 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
5486 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
5487 {
5488   PetscErrorCode ierr;
5489 
5490   PetscFunctionBegin;
5491   if (scall == MAT_INITIAL_MATRIX) {
5492     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5493     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
5494     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5495   }
5496   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5497   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
5498   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5499   PetscFunctionReturn(0);
5500 }
5501 
5502 #if defined(PETSC_HAVE_MUMPS)
5503 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_mumps(Mat,MatFactorType,Mat*);
5504 #endif
5505 #if defined(PETSC_HAVE_PASTIX)
5506 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
5507 #endif
5508 #if defined(PETSC_HAVE_SUPERLU_DIST)
5509 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
5510 #endif
5511 #if defined(PETSC_HAVE_CLIQUE)
5512 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_clique(Mat,MatFactorType,Mat*);
5513 #endif
5514 
5515 /*MC
5516    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
5517 
5518    Options Database Keys:
5519 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
5520 
5521   Level: beginner
5522 
5523 .seealso: MatCreateAIJ()
5524 M*/
5525 
5526 #undef __FUNCT__
5527 #define __FUNCT__ "MatCreate_MPIAIJ"
5528 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
5529 {
5530   Mat_MPIAIJ     *b;
5531   PetscErrorCode ierr;
5532   PetscMPIInt    size;
5533 
5534   PetscFunctionBegin;
5535   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)B),&size);CHKERRQ(ierr);
5536 
5537   ierr          = PetscNewLog(B,&b);CHKERRQ(ierr);
5538   B->data       = (void*)b;
5539   ierr          = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
5540   B->assembled  = PETSC_FALSE;
5541   B->insertmode = NOT_SET_VALUES;
5542   b->size       = size;
5543 
5544   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)B),&b->rank);CHKERRQ(ierr);
5545 
5546   /* build cache for off array entries formed */
5547   ierr = MatStashCreate_Private(PetscObjectComm((PetscObject)B),1,&B->stash);CHKERRQ(ierr);
5548 
5549   b->donotstash  = PETSC_FALSE;
5550   b->colmap      = 0;
5551   b->garray      = 0;
5552   b->roworiented = PETSC_TRUE;
5553 
5554   /* stuff used for matrix vector multiply */
5555   b->lvec  = NULL;
5556   b->Mvctx = NULL;
5557 
5558   /* stuff for MatGetRow() */
5559   b->rowindices   = 0;
5560   b->rowvalues    = 0;
5561   b->getrowactive = PETSC_FALSE;
5562 
5563   /* flexible pointer used in CUSP/CUSPARSE classes */
5564   b->spptr = NULL;
5565 
5566 #if defined(PETSC_HAVE_MUMPS)
5567   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_mumps_C",MatGetFactor_aij_mumps);CHKERRQ(ierr);
5568 #endif
5569 #if defined(PETSC_HAVE_PASTIX)
5570   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_pastix_C",MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
5571 #endif
5572 #if defined(PETSC_HAVE_SUPERLU_DIST)
5573   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_superlu_dist_C",MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
5574 #endif
5575 #if defined(PETSC_HAVE_CLIQUE)
5576   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_clique_C",MatGetFactor_aij_clique);CHKERRQ(ierr);
5577 #endif
5578   ierr = PetscObjectComposeFunction((PetscObject)B,"MatStoreValues_C",MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5579   ierr = PetscObjectComposeFunction((PetscObject)B,"MatRetrieveValues_C",MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5580   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetDiagonalBlock_C",MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5581   ierr = PetscObjectComposeFunction((PetscObject)B,"MatIsTranspose_C",MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5582   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5583   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5584   ierr = PetscObjectComposeFunction((PetscObject)B,"MatDiagonalScaleLocal_C",MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5585   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
5586   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5587   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5588 #if defined(PETSC_HAVE_ELEMENTAL)
5589   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_elemental_C",MatConvert_MPIAIJ_Elemental);CHKERRQ(ierr);
5590 #endif
5591   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5592   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5593   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5594   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5595   PetscFunctionReturn(0);
5596 }
5597 
5598 #undef __FUNCT__
5599 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5600 /*@
5601      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5602          and "off-diagonal" part of the matrix in CSR format.
5603 
5604    Collective on MPI_Comm
5605 
5606    Input Parameters:
5607 +  comm - MPI communicator
5608 .  m - number of local rows (Cannot be PETSC_DECIDE)
5609 .  n - This value should be the same as the local size used in creating the
5610        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5611        calculated if N is given) For square matrices n is almost always m.
5612 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5613 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5614 .   i - row indices for "diagonal" portion of matrix
5615 .   j - column indices
5616 .   a - matrix values
5617 .   oi - row indices for "off-diagonal" portion of matrix
5618 .   oj - column indices
5619 -   oa - matrix values
5620 
5621    Output Parameter:
5622 .   mat - the matrix
5623 
5624    Level: advanced
5625 
5626    Notes:
5627        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5628        must free the arrays once the matrix has been destroyed and not before.
5629 
5630        The i and j indices are 0 based
5631 
5632        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5633 
5634        This sets local rows and cannot be used to set off-processor values.
5635 
5636        Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
5637        legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
5638        not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
5639        the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
5640        keep track of the underlying array. Use MatSetOption(A,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE) to disable all
5641        communication if it is known that only local entries will be set.
5642 
5643 .keywords: matrix, aij, compressed row, sparse, parallel
5644 
5645 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5646           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5647 @*/
5648 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)
5649 {
5650   PetscErrorCode ierr;
5651   Mat_MPIAIJ     *maij;
5652 
5653   PetscFunctionBegin;
5654   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5655   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5656   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5657   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5658   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5659   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5660   maij = (Mat_MPIAIJ*) (*mat)->data;
5661 
5662   (*mat)->preallocated = PETSC_TRUE;
5663 
5664   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5665   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5666 
5667   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5668   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5669 
5670   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5671   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5672   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5673   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5674 
5675   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5676   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5677   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
5678   PetscFunctionReturn(0);
5679 }
5680 
5681 /*
5682     Special version for direct calls from Fortran
5683 */
5684 #include <petsc-private/fortranimpl.h>
5685 
5686 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5687 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5688 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5689 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5690 #endif
5691 
5692 /* Change these macros so can be used in void function */
5693 #undef CHKERRQ
5694 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5695 #undef SETERRQ2
5696 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5697 #undef SETERRQ3
5698 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5699 #undef SETERRQ
5700 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5701 
5702 #undef __FUNCT__
5703 #define __FUNCT__ "matsetvaluesmpiaij_"
5704 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)
5705 {
5706   Mat            mat  = *mmat;
5707   PetscInt       m    = *mm, n = *mn;
5708   InsertMode     addv = *maddv;
5709   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
5710   PetscScalar    value;
5711   PetscErrorCode ierr;
5712 
5713   MatCheckPreallocated(mat,1);
5714   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
5715 
5716 #if defined(PETSC_USE_DEBUG)
5717   else if (mat->insertmode != addv) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5718 #endif
5719   {
5720     PetscInt  i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
5721     PetscInt  cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5722     PetscBool roworiented = aij->roworiented;
5723 
5724     /* Some Variables required in the macro */
5725     Mat        A                 = aij->A;
5726     Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
5727     PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5728     MatScalar  *aa               = a->a;
5729     PetscBool  ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
5730     Mat        B                 = aij->B;
5731     Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
5732     PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5733     MatScalar  *ba               = b->a;
5734 
5735     PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5736     PetscInt  nonew = a->nonew;
5737     MatScalar *ap1,*ap2;
5738 
5739     PetscFunctionBegin;
5740     for (i=0; i<m; i++) {
5741       if (im[i] < 0) continue;
5742 #if defined(PETSC_USE_DEBUG)
5743       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);
5744 #endif
5745       if (im[i] >= rstart && im[i] < rend) {
5746         row      = im[i] - rstart;
5747         lastcol1 = -1;
5748         rp1      = aj + ai[row];
5749         ap1      = aa + ai[row];
5750         rmax1    = aimax[row];
5751         nrow1    = ailen[row];
5752         low1     = 0;
5753         high1    = nrow1;
5754         lastcol2 = -1;
5755         rp2      = bj + bi[row];
5756         ap2      = ba + bi[row];
5757         rmax2    = bimax[row];
5758         nrow2    = bilen[row];
5759         low2     = 0;
5760         high2    = nrow2;
5761 
5762         for (j=0; j<n; j++) {
5763           if (roworiented) value = v[i*n+j];
5764           else value = v[i+j*m];
5765           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5766           if (in[j] >= cstart && in[j] < cend) {
5767             col = in[j] - cstart;
5768             MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5769           } else if (in[j] < 0) continue;
5770 #if defined(PETSC_USE_DEBUG)
5771           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);
5772 #endif
5773           else {
5774             if (mat->was_assembled) {
5775               if (!aij->colmap) {
5776                 ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5777               }
5778 #if defined(PETSC_USE_CTABLE)
5779               ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5780               col--;
5781 #else
5782               col = aij->colmap[in[j]] - 1;
5783 #endif
5784               if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5785                 ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5786                 col  =  in[j];
5787                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5788                 B     = aij->B;
5789                 b     = (Mat_SeqAIJ*)B->data;
5790                 bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5791                 rp2   = bj + bi[row];
5792                 ap2   = ba + bi[row];
5793                 rmax2 = bimax[row];
5794                 nrow2 = bilen[row];
5795                 low2  = 0;
5796                 high2 = nrow2;
5797                 bm    = aij->B->rmap->n;
5798                 ba    = b->a;
5799               }
5800             } else col = in[j];
5801             MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
5802           }
5803         }
5804       } else if (!aij->donotstash) {
5805         if (roworiented) {
5806           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5807         } else {
5808           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5809         }
5810       }
5811     }
5812   }
5813   PetscFunctionReturnVoid();
5814 }
5815 
5816