xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 0572e44db5edf21c794fbeeeef78eb44bc82414b)
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->subcomm) {
1147       ierr = PetscCommDestroy(&redund->subcomm);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;
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   PetscBool      newsubcomm=PETSC_FALSE;
2764 
2765   PetscFunctionBegin;
2766   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
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     ierr = PetscCommDuplicate(psubcomm->comm,&subcomm,NULL);CHKERRQ(ierr);
2777     newsubcomm = PETSC_TRUE;
2778     if (psubcomm->type == PETSC_SUBCOMM_INTERLACED) {
2779       ierr = MatGetRedundantMatrix_MPIAIJ_interlaced(mat,nsubcomm,subcomm,reuse,matredundant);CHKERRQ(ierr);
2780       ierr = PetscSubcommDestroy(&psubcomm);CHKERRQ(ierr);
2781       PetscFunctionReturn(0);
2782     }
2783     ierr = PetscSubcommDestroy(&psubcomm);CHKERRQ(ierr);
2784   }
2785 
2786   /* get isrow and iscol for redund->type == PETSC_SUBCOMM_CONTIGUOUS */
2787   if (reuse == MAT_INITIAL_MATRIX) {
2788     /* create a local sequential matrix matseq[0] */
2789     mloc_sub = PETSC_DECIDE;
2790     ierr = PetscSplitOwnership(subcomm,&mloc_sub,&M);CHKERRQ(ierr);
2791     ierr = MPI_Scan(&mloc_sub,&rend,1,MPIU_INT,MPI_SUM,subcomm);CHKERRQ(ierr);
2792     rstart = rend - mloc_sub;
2793     ierr = ISCreateStride(PETSC_COMM_SELF,mloc_sub,rstart,1,&isrow);CHKERRQ(ierr);
2794     ierr = ISCreateStride(PETSC_COMM_SELF,N,0,1,&iscol);CHKERRQ(ierr);
2795   } else { /* reuse == MAT_REUSE_MATRIX */
2796     /* retrieve subcomm */
2797     ierr = PetscObjectGetComm((PetscObject)(*matredundant),&subcomm);CHKERRQ(ierr);
2798     redund = (*matredundant)->redundant;
2799     if (redund->type == PETSC_SUBCOMM_INTERLACED) {
2800       ierr = MatGetRedundantMatrix_MPIAIJ_interlaced(mat,nsubcomm,subcomm,reuse,matredundant);CHKERRQ(ierr);
2801       PetscFunctionReturn(0);
2802     }
2803 
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     if (newsubcomm) {
2819       redund->subcomm          = subcomm;
2820     } else {
2821       redund->subcomm          = MPI_COMM_NULL;
2822     }
2823     redund->type               = PETSC_SUBCOMM_CONTIGUOUS;
2824   }
2825   PetscFunctionReturn(0);
2826 }
2827 
2828 #undef __FUNCT__
2829 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2830 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2831 {
2832   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2833   PetscErrorCode ierr;
2834   PetscInt       i,*idxb = 0;
2835   PetscScalar    *va,*vb;
2836   Vec            vtmp;
2837 
2838   PetscFunctionBegin;
2839   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2840   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2841   if (idx) {
2842     for (i=0; i<A->rmap->n; i++) {
2843       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2844     }
2845   }
2846 
2847   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2848   if (idx) {
2849     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2850   }
2851   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2852   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2853 
2854   for (i=0; i<A->rmap->n; i++) {
2855     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2856       va[i] = vb[i];
2857       if (idx) idx[i] = a->garray[idxb[i]];
2858     }
2859   }
2860 
2861   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2862   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2863   ierr = PetscFree(idxb);CHKERRQ(ierr);
2864   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2865   PetscFunctionReturn(0);
2866 }
2867 
2868 #undef __FUNCT__
2869 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2870 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2871 {
2872   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2873   PetscErrorCode ierr;
2874   PetscInt       i,*idxb = 0;
2875   PetscScalar    *va,*vb;
2876   Vec            vtmp;
2877 
2878   PetscFunctionBegin;
2879   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2880   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2881   if (idx) {
2882     for (i=0; i<A->cmap->n; i++) {
2883       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2884     }
2885   }
2886 
2887   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2888   if (idx) {
2889     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2890   }
2891   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2892   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2893 
2894   for (i=0; i<A->rmap->n; i++) {
2895     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2896       va[i] = vb[i];
2897       if (idx) idx[i] = a->garray[idxb[i]];
2898     }
2899   }
2900 
2901   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2902   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2903   ierr = PetscFree(idxb);CHKERRQ(ierr);
2904   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2905   PetscFunctionReturn(0);
2906 }
2907 
2908 #undef __FUNCT__
2909 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2910 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2911 {
2912   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2913   PetscInt       n      = A->rmap->n;
2914   PetscInt       cstart = A->cmap->rstart;
2915   PetscInt       *cmap  = mat->garray;
2916   PetscInt       *diagIdx, *offdiagIdx;
2917   Vec            diagV, offdiagV;
2918   PetscScalar    *a, *diagA, *offdiagA;
2919   PetscInt       r;
2920   PetscErrorCode ierr;
2921 
2922   PetscFunctionBegin;
2923   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2924   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &diagV);CHKERRQ(ierr);
2925   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &offdiagV);CHKERRQ(ierr);
2926   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2927   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2928   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2929   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2930   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2931   for (r = 0; r < n; ++r) {
2932     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2933       a[r]   = diagA[r];
2934       idx[r] = cstart + diagIdx[r];
2935     } else {
2936       a[r]   = offdiagA[r];
2937       idx[r] = cmap[offdiagIdx[r]];
2938     }
2939   }
2940   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2941   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2942   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2943   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2944   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2945   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2946   PetscFunctionReturn(0);
2947 }
2948 
2949 #undef __FUNCT__
2950 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2951 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2952 {
2953   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2954   PetscInt       n      = A->rmap->n;
2955   PetscInt       cstart = A->cmap->rstart;
2956   PetscInt       *cmap  = mat->garray;
2957   PetscInt       *diagIdx, *offdiagIdx;
2958   Vec            diagV, offdiagV;
2959   PetscScalar    *a, *diagA, *offdiagA;
2960   PetscInt       r;
2961   PetscErrorCode ierr;
2962 
2963   PetscFunctionBegin;
2964   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2965   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &diagV);CHKERRQ(ierr);
2966   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &offdiagV);CHKERRQ(ierr);
2967   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2968   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2969   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2970   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2971   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2972   for (r = 0; r < n; ++r) {
2973     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2974       a[r]   = diagA[r];
2975       idx[r] = cstart + diagIdx[r];
2976     } else {
2977       a[r]   = offdiagA[r];
2978       idx[r] = cmap[offdiagIdx[r]];
2979     }
2980   }
2981   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2982   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2983   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2984   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2985   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2986   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2987   PetscFunctionReturn(0);
2988 }
2989 
2990 #undef __FUNCT__
2991 #define __FUNCT__ "MatGetSeqNonzeroStructure_MPIAIJ"
2992 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
2993 {
2994   PetscErrorCode ierr;
2995   Mat            *dummy;
2996 
2997   PetscFunctionBegin;
2998   ierr    = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
2999   *newmat = *dummy;
3000   ierr    = PetscFree(dummy);CHKERRQ(ierr);
3001   PetscFunctionReturn(0);
3002 }
3003 
3004 #undef __FUNCT__
3005 #define __FUNCT__ "MatInvertBlockDiagonal_MPIAIJ"
3006 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
3007 {
3008   Mat_MPIAIJ     *a = (Mat_MPIAIJ*) A->data;
3009   PetscErrorCode ierr;
3010 
3011   PetscFunctionBegin;
3012   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
3013   PetscFunctionReturn(0);
3014 }
3015 
3016 #undef __FUNCT__
3017 #define __FUNCT__ "MatSetRandom_MPIAIJ"
3018 static PetscErrorCode  MatSetRandom_MPIAIJ(Mat x,PetscRandom rctx)
3019 {
3020   PetscErrorCode ierr;
3021   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)x->data;
3022 
3023   PetscFunctionBegin;
3024   ierr = MatSetRandom(aij->A,rctx);CHKERRQ(ierr);
3025   ierr = MatSetRandom(aij->B,rctx);CHKERRQ(ierr);
3026   ierr = MatAssemblyBegin(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3027   ierr = MatAssemblyEnd(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3028   PetscFunctionReturn(0);
3029 }
3030 
3031 /* -------------------------------------------------------------------*/
3032 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
3033                                        MatGetRow_MPIAIJ,
3034                                        MatRestoreRow_MPIAIJ,
3035                                        MatMult_MPIAIJ,
3036                                 /* 4*/ MatMultAdd_MPIAIJ,
3037                                        MatMultTranspose_MPIAIJ,
3038                                        MatMultTransposeAdd_MPIAIJ,
3039 #if defined(PETSC_HAVE_PBGL)
3040                                        MatSolve_MPIAIJ,
3041 #else
3042                                        0,
3043 #endif
3044                                        0,
3045                                        0,
3046                                 /*10*/ 0,
3047                                        0,
3048                                        0,
3049                                        MatSOR_MPIAIJ,
3050                                        MatTranspose_MPIAIJ,
3051                                 /*15*/ MatGetInfo_MPIAIJ,
3052                                        MatEqual_MPIAIJ,
3053                                        MatGetDiagonal_MPIAIJ,
3054                                        MatDiagonalScale_MPIAIJ,
3055                                        MatNorm_MPIAIJ,
3056                                 /*20*/ MatAssemblyBegin_MPIAIJ,
3057                                        MatAssemblyEnd_MPIAIJ,
3058                                        MatSetOption_MPIAIJ,
3059                                        MatZeroEntries_MPIAIJ,
3060                                 /*24*/ MatZeroRows_MPIAIJ,
3061                                        0,
3062 #if defined(PETSC_HAVE_PBGL)
3063                                        0,
3064 #else
3065                                        0,
3066 #endif
3067                                        0,
3068                                        0,
3069                                 /*29*/ MatSetUp_MPIAIJ,
3070 #if defined(PETSC_HAVE_PBGL)
3071                                        0,
3072 #else
3073                                        0,
3074 #endif
3075                                        0,
3076                                        0,
3077                                        0,
3078                                 /*34*/ MatDuplicate_MPIAIJ,
3079                                        0,
3080                                        0,
3081                                        0,
3082                                        0,
3083                                 /*39*/ MatAXPY_MPIAIJ,
3084                                        MatGetSubMatrices_MPIAIJ,
3085                                        MatIncreaseOverlap_MPIAIJ,
3086                                        MatGetValues_MPIAIJ,
3087                                        MatCopy_MPIAIJ,
3088                                 /*44*/ MatGetRowMax_MPIAIJ,
3089                                        MatScale_MPIAIJ,
3090                                        0,
3091                                        MatDiagonalSet_MPIAIJ,
3092                                        MatZeroRowsColumns_MPIAIJ,
3093                                 /*49*/ MatSetRandom_MPIAIJ,
3094                                        0,
3095                                        0,
3096                                        0,
3097                                        0,
3098                                 /*54*/ MatFDColoringCreate_MPIXAIJ,
3099                                        0,
3100                                        MatSetUnfactored_MPIAIJ,
3101                                        MatPermute_MPIAIJ,
3102                                        0,
3103                                 /*59*/ MatGetSubMatrix_MPIAIJ,
3104                                        MatDestroy_MPIAIJ,
3105                                        MatView_MPIAIJ,
3106                                        0,
3107                                        MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ,
3108                                 /*64*/ MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ,
3109                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
3110                                        0,
3111                                        0,
3112                                        0,
3113                                 /*69*/ MatGetRowMaxAbs_MPIAIJ,
3114                                        MatGetRowMinAbs_MPIAIJ,
3115                                        0,
3116                                        MatSetColoring_MPIAIJ,
3117                                        0,
3118                                        MatSetValuesAdifor_MPIAIJ,
3119                                 /*75*/ MatFDColoringApply_AIJ,
3120                                        0,
3121                                        0,
3122                                        0,
3123                                        MatFindZeroDiagonals_MPIAIJ,
3124                                 /*80*/ 0,
3125                                        0,
3126                                        0,
3127                                 /*83*/ MatLoad_MPIAIJ,
3128                                        0,
3129                                        0,
3130                                        0,
3131                                        0,
3132                                        0,
3133                                 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
3134                                        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
3135                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
3136                                        MatPtAP_MPIAIJ_MPIAIJ,
3137                                        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
3138                                 /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
3139                                        0,
3140                                        0,
3141                                        0,
3142                                        0,
3143                                 /*99*/ 0,
3144                                        0,
3145                                        0,
3146                                        MatConjugate_MPIAIJ,
3147                                        0,
3148                                 /*104*/MatSetValuesRow_MPIAIJ,
3149                                        MatRealPart_MPIAIJ,
3150                                        MatImaginaryPart_MPIAIJ,
3151                                        0,
3152                                        0,
3153                                 /*109*/0,
3154                                        MatGetRedundantMatrix_MPIAIJ,
3155                                        MatGetRowMin_MPIAIJ,
3156                                        0,
3157                                        0,
3158                                 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
3159                                        0,
3160                                        0,
3161                                        0,
3162                                        0,
3163                                 /*119*/0,
3164                                        0,
3165                                        0,
3166                                        0,
3167                                        MatGetMultiProcBlock_MPIAIJ,
3168                                 /*124*/MatFindNonzeroRows_MPIAIJ,
3169                                        MatGetColumnNorms_MPIAIJ,
3170                                        MatInvertBlockDiagonal_MPIAIJ,
3171                                        0,
3172                                        MatGetSubMatricesParallel_MPIAIJ,
3173                                 /*129*/0,
3174                                        MatTransposeMatMult_MPIAIJ_MPIAIJ,
3175                                        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
3176                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
3177                                        0,
3178                                 /*134*/0,
3179                                        0,
3180                                        0,
3181                                        0,
3182                                        0,
3183                                 /*139*/0,
3184                                        0,
3185                                        0,
3186                                        MatFDColoringSetUp_MPIXAIJ,
3187                                        0,
3188                                 /*144*/MatCreateMPIMatConcatenateSeqMat_MPIAIJ
3189 };
3190 
3191 /* ----------------------------------------------------------------------------------------*/
3192 
3193 #undef __FUNCT__
3194 #define __FUNCT__ "MatStoreValues_MPIAIJ"
3195 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
3196 {
3197   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3198   PetscErrorCode ierr;
3199 
3200   PetscFunctionBegin;
3201   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
3202   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
3203   PetscFunctionReturn(0);
3204 }
3205 
3206 #undef __FUNCT__
3207 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
3208 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
3209 {
3210   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3211   PetscErrorCode ierr;
3212 
3213   PetscFunctionBegin;
3214   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
3215   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
3216   PetscFunctionReturn(0);
3217 }
3218 
3219 #undef __FUNCT__
3220 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
3221 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3222 {
3223   Mat_MPIAIJ     *b;
3224   PetscErrorCode ierr;
3225 
3226   PetscFunctionBegin;
3227   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3228   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3229   b = (Mat_MPIAIJ*)B->data;
3230 
3231   if (!B->preallocated) {
3232     /* Explicitly create 2 MATSEQAIJ matrices. */
3233     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
3234     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
3235     ierr = MatSetBlockSizesFromMats(b->A,B,B);CHKERRQ(ierr);
3236     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
3237     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->A);CHKERRQ(ierr);
3238     ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
3239     ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
3240     ierr = MatSetBlockSizesFromMats(b->B,B,B);CHKERRQ(ierr);
3241     ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
3242     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->B);CHKERRQ(ierr);
3243   }
3244 
3245   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
3246   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
3247   B->preallocated = PETSC_TRUE;
3248   PetscFunctionReturn(0);
3249 }
3250 
3251 #undef __FUNCT__
3252 #define __FUNCT__ "MatDuplicate_MPIAIJ"
3253 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
3254 {
3255   Mat            mat;
3256   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
3257   PetscErrorCode ierr;
3258 
3259   PetscFunctionBegin;
3260   *newmat = 0;
3261   ierr    = MatCreate(PetscObjectComm((PetscObject)matin),&mat);CHKERRQ(ierr);
3262   ierr    = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
3263   ierr    = MatSetBlockSizesFromMats(mat,matin,matin);CHKERRQ(ierr);
3264   ierr    = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
3265   ierr    = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
3266   a       = (Mat_MPIAIJ*)mat->data;
3267 
3268   mat->factortype   = matin->factortype;
3269   mat->assembled    = PETSC_TRUE;
3270   mat->insertmode   = NOT_SET_VALUES;
3271   mat->preallocated = PETSC_TRUE;
3272 
3273   a->size         = oldmat->size;
3274   a->rank         = oldmat->rank;
3275   a->donotstash   = oldmat->donotstash;
3276   a->roworiented  = oldmat->roworiented;
3277   a->rowindices   = 0;
3278   a->rowvalues    = 0;
3279   a->getrowactive = PETSC_FALSE;
3280 
3281   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
3282   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
3283 
3284   if (oldmat->colmap) {
3285 #if defined(PETSC_USE_CTABLE)
3286     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
3287 #else
3288     ierr = PetscMalloc1((mat->cmap->N),&a->colmap);CHKERRQ(ierr);
3289     ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3290     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3291 #endif
3292   } else a->colmap = 0;
3293   if (oldmat->garray) {
3294     PetscInt len;
3295     len  = oldmat->B->cmap->n;
3296     ierr = PetscMalloc1((len+1),&a->garray);CHKERRQ(ierr);
3297     ierr = PetscLogObjectMemory((PetscObject)mat,len*sizeof(PetscInt));CHKERRQ(ierr);
3298     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
3299   } else a->garray = 0;
3300 
3301   ierr    = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
3302   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->lvec);CHKERRQ(ierr);
3303   ierr    = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
3304   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->Mvctx);CHKERRQ(ierr);
3305   ierr    = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
3306   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->A);CHKERRQ(ierr);
3307   ierr    = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
3308   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->B);CHKERRQ(ierr);
3309   ierr    = PetscFunctionListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
3310   *newmat = mat;
3311   PetscFunctionReturn(0);
3312 }
3313 
3314 
3315 
3316 #undef __FUNCT__
3317 #define __FUNCT__ "MatLoad_MPIAIJ"
3318 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
3319 {
3320   PetscScalar    *vals,*svals;
3321   MPI_Comm       comm;
3322   PetscErrorCode ierr;
3323   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
3324   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0,grows,gcols;
3325   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
3326   PetscInt       *ourlens = NULL,*procsnz = NULL,*offlens = NULL,jj,*mycols,*smycols;
3327   PetscInt       cend,cstart,n,*rowners,sizesset=1;
3328   int            fd;
3329   PetscInt       bs = 1;
3330 
3331   PetscFunctionBegin;
3332   ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
3333   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3334   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3335   if (!rank) {
3336     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
3337     ierr = PetscBinaryRead(fd,(char*)header,4,PETSC_INT);CHKERRQ(ierr);
3338     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
3339   }
3340 
3341   ierr = PetscOptionsBegin(comm,NULL,"Options for loading SEQAIJ matrix","Mat");CHKERRQ(ierr);
3342   ierr = PetscOptionsInt("-matload_block_size","Set the blocksize used to store the matrix","MatLoad",bs,&bs,NULL);CHKERRQ(ierr);
3343   ierr = PetscOptionsEnd();CHKERRQ(ierr);
3344 
3345   if (newMat->rmap->n < 0 && newMat->rmap->N < 0 && newMat->cmap->n < 0 && newMat->cmap->N < 0) sizesset = 0;
3346 
3347   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
3348   M    = header[1]; N = header[2];
3349   /* If global rows/cols are set to PETSC_DECIDE, set it to the sizes given in the file */
3350   if (sizesset && newMat->rmap->N < 0) newMat->rmap->N = M;
3351   if (sizesset && newMat->cmap->N < 0) newMat->cmap->N = N;
3352 
3353   /* If global sizes are set, check if they are consistent with that given in the file */
3354   if (sizesset) {
3355     ierr = MatGetSize(newMat,&grows,&gcols);CHKERRQ(ierr);
3356   }
3357   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);
3358   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);
3359 
3360   /* determine ownership of all (block) rows */
3361   if (M%bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows (%d) and block size (%d)",M,bs);
3362   if (newMat->rmap->n < 0) m = bs*((M/bs)/size + (((M/bs) % size) > rank));    /* PETSC_DECIDE */
3363   else m = newMat->rmap->n; /* Set by user */
3364 
3365   ierr = PetscMalloc1((size+1),&rowners);CHKERRQ(ierr);
3366   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
3367 
3368   /* First process needs enough room for process with most rows */
3369   if (!rank) {
3370     mmax = rowners[1];
3371     for (i=2; i<=size; i++) {
3372       mmax = PetscMax(mmax, rowners[i]);
3373     }
3374   } else mmax = -1;             /* unused, but compilers complain */
3375 
3376   rowners[0] = 0;
3377   for (i=2; i<=size; i++) {
3378     rowners[i] += rowners[i-1];
3379   }
3380   rstart = rowners[rank];
3381   rend   = rowners[rank+1];
3382 
3383   /* distribute row lengths to all processors */
3384   ierr = PetscMalloc2(m,&ourlens,m,&offlens);CHKERRQ(ierr);
3385   if (!rank) {
3386     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
3387     ierr = PetscMalloc1(mmax,&rowlengths);CHKERRQ(ierr);
3388     ierr = PetscCalloc1(size,&procsnz);CHKERRQ(ierr);
3389     for (j=0; j<m; j++) {
3390       procsnz[0] += ourlens[j];
3391     }
3392     for (i=1; i<size; i++) {
3393       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
3394       /* calculate the number of nonzeros on each processor */
3395       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
3396         procsnz[i] += rowlengths[j];
3397       }
3398       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3399     }
3400     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
3401   } else {
3402     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3403   }
3404 
3405   if (!rank) {
3406     /* determine max buffer needed and allocate it */
3407     maxnz = 0;
3408     for (i=0; i<size; i++) {
3409       maxnz = PetscMax(maxnz,procsnz[i]);
3410     }
3411     ierr = PetscMalloc1(maxnz,&cols);CHKERRQ(ierr);
3412 
3413     /* read in my part of the matrix column indices  */
3414     nz   = procsnz[0];
3415     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
3416     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
3417 
3418     /* read in every one elses and ship off */
3419     for (i=1; i<size; i++) {
3420       nz   = procsnz[i];
3421       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
3422       ierr = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3423     }
3424     ierr = PetscFree(cols);CHKERRQ(ierr);
3425   } else {
3426     /* determine buffer space needed for message */
3427     nz = 0;
3428     for (i=0; i<m; i++) {
3429       nz += ourlens[i];
3430     }
3431     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
3432 
3433     /* receive message of column indices*/
3434     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3435   }
3436 
3437   /* determine column ownership if matrix is not square */
3438   if (N != M) {
3439     if (newMat->cmap->n < 0) n = N/size + ((N % size) > rank);
3440     else n = newMat->cmap->n;
3441     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3442     cstart = cend - n;
3443   } else {
3444     cstart = rstart;
3445     cend   = rend;
3446     n      = cend - cstart;
3447   }
3448 
3449   /* loop over local rows, determining number of off diagonal entries */
3450   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
3451   jj   = 0;
3452   for (i=0; i<m; i++) {
3453     for (j=0; j<ourlens[i]; j++) {
3454       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
3455       jj++;
3456     }
3457   }
3458 
3459   for (i=0; i<m; i++) {
3460     ourlens[i] -= offlens[i];
3461   }
3462   if (!sizesset) {
3463     ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
3464   }
3465 
3466   if (bs > 1) {ierr = MatSetBlockSize(newMat,bs);CHKERRQ(ierr);}
3467 
3468   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
3469 
3470   for (i=0; i<m; i++) {
3471     ourlens[i] += offlens[i];
3472   }
3473 
3474   if (!rank) {
3475     ierr = PetscMalloc1((maxnz+1),&vals);CHKERRQ(ierr);
3476 
3477     /* read in my part of the matrix numerical values  */
3478     nz   = procsnz[0];
3479     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3480 
3481     /* insert into matrix */
3482     jj      = rstart;
3483     smycols = mycols;
3484     svals   = vals;
3485     for (i=0; i<m; i++) {
3486       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3487       smycols += ourlens[i];
3488       svals   += ourlens[i];
3489       jj++;
3490     }
3491 
3492     /* read in other processors and ship out */
3493     for (i=1; i<size; i++) {
3494       nz   = procsnz[i];
3495       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3496       ierr = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3497     }
3498     ierr = PetscFree(procsnz);CHKERRQ(ierr);
3499   } else {
3500     /* receive numeric values */
3501     ierr = PetscMalloc1((nz+1),&vals);CHKERRQ(ierr);
3502 
3503     /* receive message of values*/
3504     ierr = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3505 
3506     /* insert into matrix */
3507     jj      = rstart;
3508     smycols = mycols;
3509     svals   = vals;
3510     for (i=0; i<m; i++) {
3511       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3512       smycols += ourlens[i];
3513       svals   += ourlens[i];
3514       jj++;
3515     }
3516   }
3517   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
3518   ierr = PetscFree(vals);CHKERRQ(ierr);
3519   ierr = PetscFree(mycols);CHKERRQ(ierr);
3520   ierr = PetscFree(rowners);CHKERRQ(ierr);
3521   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3522   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3523   PetscFunctionReturn(0);
3524 }
3525 
3526 #undef __FUNCT__
3527 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3528 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3529 {
3530   PetscErrorCode ierr;
3531   IS             iscol_local;
3532   PetscInt       csize;
3533 
3534   PetscFunctionBegin;
3535   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3536   if (call == MAT_REUSE_MATRIX) {
3537     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3538     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3539   } else {
3540     PetscInt cbs;
3541     ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3542     ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
3543     ierr = ISSetBlockSize(iscol_local,cbs);CHKERRQ(ierr);
3544   }
3545   ierr = MatGetSubMatrix_MPIAIJ_Private(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3546   if (call == MAT_INITIAL_MATRIX) {
3547     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3548     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3549   }
3550   PetscFunctionReturn(0);
3551 }
3552 
3553 extern PetscErrorCode MatGetSubMatrices_MPIAIJ_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool*,Mat*);
3554 #undef __FUNCT__
3555 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ_Private"
3556 /*
3557     Not great since it makes two copies of the submatrix, first an SeqAIJ
3558   in local and then by concatenating the local matrices the end result.
3559   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3560 
3561   Note: This requires a sequential iscol with all indices.
3562 */
3563 PetscErrorCode MatGetSubMatrix_MPIAIJ_Private(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3564 {
3565   PetscErrorCode ierr;
3566   PetscMPIInt    rank,size;
3567   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3568   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal,ncol;
3569   PetscBool      allcolumns, colflag;
3570   Mat            M,Mreuse;
3571   MatScalar      *vwork,*aa;
3572   MPI_Comm       comm;
3573   Mat_SeqAIJ     *aij;
3574 
3575   PetscFunctionBegin;
3576   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3577   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3578   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3579 
3580   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3581   ierr = ISGetLocalSize(iscol,&ncol);CHKERRQ(ierr);
3582   if (colflag && ncol == mat->cmap->N) {
3583     allcolumns = PETSC_TRUE;
3584   } else {
3585     allcolumns = PETSC_FALSE;
3586   }
3587   if (call ==  MAT_REUSE_MATRIX) {
3588     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Mreuse);CHKERRQ(ierr);
3589     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3590     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3591   } else {
3592     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3593   }
3594 
3595   /*
3596       m - number of local rows
3597       n - number of columns (same on all processors)
3598       rstart - first row in new global matrix generated
3599   */
3600   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3601   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3602   if (call == MAT_INITIAL_MATRIX) {
3603     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3604     ii  = aij->i;
3605     jj  = aij->j;
3606 
3607     /*
3608         Determine the number of non-zeros in the diagonal and off-diagonal
3609         portions of the matrix in order to do correct preallocation
3610     */
3611 
3612     /* first get start and end of "diagonal" columns */
3613     if (csize == PETSC_DECIDE) {
3614       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3615       if (mglobal == n) { /* square matrix */
3616         nlocal = m;
3617       } else {
3618         nlocal = n/size + ((n % size) > rank);
3619       }
3620     } else {
3621       nlocal = csize;
3622     }
3623     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3624     rstart = rend - nlocal;
3625     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);
3626 
3627     /* next, compute all the lengths */
3628     ierr  = PetscMalloc1((2*m+1),&dlens);CHKERRQ(ierr);
3629     olens = dlens + m;
3630     for (i=0; i<m; i++) {
3631       jend = ii[i+1] - ii[i];
3632       olen = 0;
3633       dlen = 0;
3634       for (j=0; j<jend; j++) {
3635         if (*jj < rstart || *jj >= rend) olen++;
3636         else dlen++;
3637         jj++;
3638       }
3639       olens[i] = olen;
3640       dlens[i] = dlen;
3641     }
3642     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3643     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3644     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3645     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3646     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3647     ierr = PetscFree(dlens);CHKERRQ(ierr);
3648   } else {
3649     PetscInt ml,nl;
3650 
3651     M    = *newmat;
3652     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3653     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3654     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3655     /*
3656          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3657        rather than the slower MatSetValues().
3658     */
3659     M->was_assembled = PETSC_TRUE;
3660     M->assembled     = PETSC_FALSE;
3661   }
3662   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3663   aij  = (Mat_SeqAIJ*)(Mreuse)->data;
3664   ii   = aij->i;
3665   jj   = aij->j;
3666   aa   = aij->a;
3667   for (i=0; i<m; i++) {
3668     row   = rstart + i;
3669     nz    = ii[i+1] - ii[i];
3670     cwork = jj;     jj += nz;
3671     vwork = aa;     aa += nz;
3672     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3673   }
3674 
3675   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3676   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3677   *newmat = M;
3678 
3679   /* save submatrix used in processor for next request */
3680   if (call ==  MAT_INITIAL_MATRIX) {
3681     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3682     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3683   }
3684   PetscFunctionReturn(0);
3685 }
3686 
3687 #undef __FUNCT__
3688 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3689 PetscErrorCode  MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3690 {
3691   PetscInt       m,cstart, cend,j,nnz,i,d;
3692   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3693   const PetscInt *JJ;
3694   PetscScalar    *values;
3695   PetscErrorCode ierr;
3696 
3697   PetscFunctionBegin;
3698   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3699 
3700   ierr   = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3701   ierr   = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3702   m      = B->rmap->n;
3703   cstart = B->cmap->rstart;
3704   cend   = B->cmap->rend;
3705   rstart = B->rmap->rstart;
3706 
3707   ierr = PetscMalloc2(m,&d_nnz,m,&o_nnz);CHKERRQ(ierr);
3708 
3709 #if defined(PETSC_USE_DEBUGGING)
3710   for (i=0; i<m; i++) {
3711     nnz = Ii[i+1]- Ii[i];
3712     JJ  = J + Ii[i];
3713     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3714     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3715     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);
3716   }
3717 #endif
3718 
3719   for (i=0; i<m; i++) {
3720     nnz     = Ii[i+1]- Ii[i];
3721     JJ      = J + Ii[i];
3722     nnz_max = PetscMax(nnz_max,nnz);
3723     d       = 0;
3724     for (j=0; j<nnz; j++) {
3725       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3726     }
3727     d_nnz[i] = d;
3728     o_nnz[i] = nnz - d;
3729   }
3730   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3731   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3732 
3733   if (v) values = (PetscScalar*)v;
3734   else {
3735     ierr = PetscCalloc1((nnz_max+1),&values);CHKERRQ(ierr);
3736   }
3737 
3738   for (i=0; i<m; i++) {
3739     ii   = i + rstart;
3740     nnz  = Ii[i+1]- Ii[i];
3741     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3742   }
3743   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3744   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3745 
3746   if (!v) {
3747     ierr = PetscFree(values);CHKERRQ(ierr);
3748   }
3749   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3750   PetscFunctionReturn(0);
3751 }
3752 
3753 #undef __FUNCT__
3754 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3755 /*@
3756    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3757    (the default parallel PETSc format).
3758 
3759    Collective on MPI_Comm
3760 
3761    Input Parameters:
3762 +  B - the matrix
3763 .  i - the indices into j for the start of each local row (starts with zero)
3764 .  j - the column indices for each local row (starts with zero)
3765 -  v - optional values in the matrix
3766 
3767    Level: developer
3768 
3769    Notes:
3770        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3771      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3772      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3773 
3774        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3775 
3776        The format which is used for the sparse matrix input, is equivalent to a
3777     row-major ordering.. i.e for the following matrix, the input data expected is
3778     as shown:
3779 
3780         1 0 0
3781         2 0 3     P0
3782        -------
3783         4 5 6     P1
3784 
3785      Process0 [P0]: rows_owned=[0,1]
3786         i =  {0,1,3}  [size = nrow+1  = 2+1]
3787         j =  {0,0,2}  [size = nz = 6]
3788         v =  {1,2,3}  [size = nz = 6]
3789 
3790      Process1 [P1]: rows_owned=[2]
3791         i =  {0,3}    [size = nrow+1  = 1+1]
3792         j =  {0,1,2}  [size = nz = 6]
3793         v =  {4,5,6}  [size = nz = 6]
3794 
3795 .keywords: matrix, aij, compressed row, sparse, parallel
3796 
3797 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MPIAIJ,
3798           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3799 @*/
3800 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3801 {
3802   PetscErrorCode ierr;
3803 
3804   PetscFunctionBegin;
3805   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
3806   PetscFunctionReturn(0);
3807 }
3808 
3809 #undef __FUNCT__
3810 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3811 /*@C
3812    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3813    (the default parallel PETSc format).  For good matrix assembly performance
3814    the user should preallocate the matrix storage by setting the parameters
3815    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3816    performance can be increased by more than a factor of 50.
3817 
3818    Collective on MPI_Comm
3819 
3820    Input Parameters:
3821 +  B - the matrix
3822 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3823            (same value is used for all local rows)
3824 .  d_nnz - array containing the number of nonzeros in the various rows of the
3825            DIAGONAL portion of the local submatrix (possibly different for each row)
3826            or NULL, if d_nz is used to specify the nonzero structure.
3827            The size of this array is equal to the number of local rows, i.e 'm'.
3828            For matrices that will be factored, you must leave room for (and set)
3829            the diagonal entry even if it is zero.
3830 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3831            submatrix (same value is used for all local rows).
3832 -  o_nnz - array containing the number of nonzeros in the various rows of the
3833            OFF-DIAGONAL portion of the local submatrix (possibly different for
3834            each row) or NULL, if o_nz is used to specify the nonzero
3835            structure. The size of this array is equal to the number
3836            of local rows, i.e 'm'.
3837 
3838    If the *_nnz parameter is given then the *_nz parameter is ignored
3839 
3840    The AIJ format (also called the Yale sparse matrix format or
3841    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3842    storage.  The stored row and column indices begin with zero.
3843    See Users-Manual: ch_mat for details.
3844 
3845    The parallel matrix is partitioned such that the first m0 rows belong to
3846    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3847    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3848 
3849    The DIAGONAL portion of the local submatrix of a processor can be defined
3850    as the submatrix which is obtained by extraction the part corresponding to
3851    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
3852    first row that belongs to the processor, r2 is the last row belonging to
3853    the this processor, and c1-c2 is range of indices of the local part of a
3854    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
3855    common case of a square matrix, the row and column ranges are the same and
3856    the DIAGONAL part is also square. The remaining portion of the local
3857    submatrix (mxN) constitute the OFF-DIAGONAL portion.
3858 
3859    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3860 
3861    You can call MatGetInfo() to get information on how effective the preallocation was;
3862    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3863    You can also run with the option -info and look for messages with the string
3864    malloc in them to see if additional memory allocation was needed.
3865 
3866    Example usage:
3867 
3868    Consider the following 8x8 matrix with 34 non-zero values, that is
3869    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3870    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3871    as follows:
3872 
3873 .vb
3874             1  2  0  |  0  3  0  |  0  4
3875     Proc0   0  5  6  |  7  0  0  |  8  0
3876             9  0 10  | 11  0  0  | 12  0
3877     -------------------------------------
3878            13  0 14  | 15 16 17  |  0  0
3879     Proc1   0 18  0  | 19 20 21  |  0  0
3880             0  0  0  | 22 23  0  | 24  0
3881     -------------------------------------
3882     Proc2  25 26 27  |  0  0 28  | 29  0
3883            30  0  0  | 31 32 33  |  0 34
3884 .ve
3885 
3886    This can be represented as a collection of submatrices as:
3887 
3888 .vb
3889       A B C
3890       D E F
3891       G H I
3892 .ve
3893 
3894    Where the submatrices A,B,C are owned by proc0, D,E,F are
3895    owned by proc1, G,H,I are owned by proc2.
3896 
3897    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3898    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3899    The 'M','N' parameters are 8,8, and have the same values on all procs.
3900 
3901    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3902    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3903    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3904    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3905    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3906    matrix, ans [DF] as another SeqAIJ matrix.
3907 
3908    When d_nz, o_nz parameters are specified, d_nz storage elements are
3909    allocated for every row of the local diagonal submatrix, and o_nz
3910    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3911    One way to choose d_nz and o_nz is to use the max nonzerors per local
3912    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3913    In this case, the values of d_nz,o_nz are:
3914 .vb
3915      proc0 : dnz = 2, o_nz = 2
3916      proc1 : dnz = 3, o_nz = 2
3917      proc2 : dnz = 1, o_nz = 4
3918 .ve
3919    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3920    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3921    for proc3. i.e we are using 12+15+10=37 storage locations to store
3922    34 values.
3923 
3924    When d_nnz, o_nnz parameters are specified, the storage is specified
3925    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3926    In the above case the values for d_nnz,o_nnz are:
3927 .vb
3928      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3929      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3930      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3931 .ve
3932    Here the space allocated is sum of all the above values i.e 34, and
3933    hence pre-allocation is perfect.
3934 
3935    Level: intermediate
3936 
3937 .keywords: matrix, aij, compressed row, sparse, parallel
3938 
3939 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
3940           MPIAIJ, MatGetInfo(), PetscSplitOwnership()
3941 @*/
3942 PetscErrorCode  MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3943 {
3944   PetscErrorCode ierr;
3945 
3946   PetscFunctionBegin;
3947   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
3948   PetscValidType(B,1);
3949   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
3950   PetscFunctionReturn(0);
3951 }
3952 
3953 #undef __FUNCT__
3954 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3955 /*@
3956      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3957          CSR format the local rows.
3958 
3959    Collective on MPI_Comm
3960 
3961    Input Parameters:
3962 +  comm - MPI communicator
3963 .  m - number of local rows (Cannot be PETSC_DECIDE)
3964 .  n - This value should be the same as the local size used in creating the
3965        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3966        calculated if N is given) For square matrices n is almost always m.
3967 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3968 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3969 .   i - row indices
3970 .   j - column indices
3971 -   a - matrix values
3972 
3973    Output Parameter:
3974 .   mat - the matrix
3975 
3976    Level: intermediate
3977 
3978    Notes:
3979        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3980      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3981      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3982 
3983        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3984 
3985        The format which is used for the sparse matrix input, is equivalent to a
3986     row-major ordering.. i.e for the following matrix, the input data expected is
3987     as shown:
3988 
3989         1 0 0
3990         2 0 3     P0
3991        -------
3992         4 5 6     P1
3993 
3994      Process0 [P0]: rows_owned=[0,1]
3995         i =  {0,1,3}  [size = nrow+1  = 2+1]
3996         j =  {0,0,2}  [size = nz = 6]
3997         v =  {1,2,3}  [size = nz = 6]
3998 
3999      Process1 [P1]: rows_owned=[2]
4000         i =  {0,3}    [size = nrow+1  = 1+1]
4001         j =  {0,1,2}  [size = nz = 6]
4002         v =  {4,5,6}  [size = nz = 6]
4003 
4004 .keywords: matrix, aij, compressed row, sparse, parallel
4005 
4006 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4007           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
4008 @*/
4009 PetscErrorCode  MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
4010 {
4011   PetscErrorCode ierr;
4012 
4013   PetscFunctionBegin;
4014   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
4015   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
4016   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
4017   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
4018   /* ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr); */
4019   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
4020   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
4021   PetscFunctionReturn(0);
4022 }
4023 
4024 #undef __FUNCT__
4025 #define __FUNCT__ "MatCreateAIJ"
4026 /*@C
4027    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
4028    (the default parallel PETSc format).  For good matrix assembly performance
4029    the user should preallocate the matrix storage by setting the parameters
4030    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4031    performance can be increased by more than a factor of 50.
4032 
4033    Collective on MPI_Comm
4034 
4035    Input Parameters:
4036 +  comm - MPI communicator
4037 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
4038            This value should be the same as the local size used in creating the
4039            y vector for the matrix-vector product y = Ax.
4040 .  n - This value should be the same as the local size used in creating the
4041        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4042        calculated if N is given) For square matrices n is almost always m.
4043 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4044 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4045 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4046            (same value is used for all local rows)
4047 .  d_nnz - array containing the number of nonzeros in the various rows of the
4048            DIAGONAL portion of the local submatrix (possibly different for each row)
4049            or NULL, if d_nz is used to specify the nonzero structure.
4050            The size of this array is equal to the number of local rows, i.e 'm'.
4051 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4052            submatrix (same value is used for all local rows).
4053 -  o_nnz - array containing the number of nonzeros in the various rows of the
4054            OFF-DIAGONAL portion of the local submatrix (possibly different for
4055            each row) or NULL, if o_nz is used to specify the nonzero
4056            structure. The size of this array is equal to the number
4057            of local rows, i.e 'm'.
4058 
4059    Output Parameter:
4060 .  A - the matrix
4061 
4062    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
4063    MatXXXXSetPreallocation() paradgm instead of this routine directly.
4064    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
4065 
4066    Notes:
4067    If the *_nnz parameter is given then the *_nz parameter is ignored
4068 
4069    m,n,M,N parameters specify the size of the matrix, and its partitioning across
4070    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
4071    storage requirements for this matrix.
4072 
4073    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
4074    processor than it must be used on all processors that share the object for
4075    that argument.
4076 
4077    The user MUST specify either the local or global matrix dimensions
4078    (possibly both).
4079 
4080    The parallel matrix is partitioned across processors such that the
4081    first m0 rows belong to process 0, the next m1 rows belong to
4082    process 1, the next m2 rows belong to process 2 etc.. where
4083    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
4084    values corresponding to [m x N] submatrix.
4085 
4086    The columns are logically partitioned with the n0 columns belonging
4087    to 0th partition, the next n1 columns belonging to the next
4088    partition etc.. where n0,n1,n2... are the input parameter 'n'.
4089 
4090    The DIAGONAL portion of the local submatrix on any given processor
4091    is the submatrix corresponding to the rows and columns m,n
4092    corresponding to the given processor. i.e diagonal matrix on
4093    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4094    etc. The remaining portion of the local submatrix [m x (N-n)]
4095    constitute the OFF-DIAGONAL portion. The example below better
4096    illustrates this concept.
4097 
4098    For a square global matrix we define each processor's diagonal portion
4099    to be its local rows and the corresponding columns (a square submatrix);
4100    each processor's off-diagonal portion encompasses the remainder of the
4101    local matrix (a rectangular submatrix).
4102 
4103    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4104 
4105    When calling this routine with a single process communicator, a matrix of
4106    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
4107    type of communicator, use the construction mechanism:
4108      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
4109 
4110    By default, this format uses inodes (identical nodes) when possible.
4111    We search for consecutive rows with the same nonzero structure, thereby
4112    reusing matrix information to achieve increased efficiency.
4113 
4114    Options Database Keys:
4115 +  -mat_no_inode  - Do not use inodes
4116 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
4117 -  -mat_aij_oneindex - Internally use indexing starting at 1
4118         rather than 0.  Note that when calling MatSetValues(),
4119         the user still MUST index entries starting at 0!
4120 
4121 
4122    Example usage:
4123 
4124    Consider the following 8x8 matrix with 34 non-zero values, that is
4125    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4126    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4127    as follows:
4128 
4129 .vb
4130             1  2  0  |  0  3  0  |  0  4
4131     Proc0   0  5  6  |  7  0  0  |  8  0
4132             9  0 10  | 11  0  0  | 12  0
4133     -------------------------------------
4134            13  0 14  | 15 16 17  |  0  0
4135     Proc1   0 18  0  | 19 20 21  |  0  0
4136             0  0  0  | 22 23  0  | 24  0
4137     -------------------------------------
4138     Proc2  25 26 27  |  0  0 28  | 29  0
4139            30  0  0  | 31 32 33  |  0 34
4140 .ve
4141 
4142    This can be represented as a collection of submatrices as:
4143 
4144 .vb
4145       A B C
4146       D E F
4147       G H I
4148 .ve
4149 
4150    Where the submatrices A,B,C are owned by proc0, D,E,F are
4151    owned by proc1, G,H,I are owned by proc2.
4152 
4153    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4154    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4155    The 'M','N' parameters are 8,8, and have the same values on all procs.
4156 
4157    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4158    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4159    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4160    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4161    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4162    matrix, ans [DF] as another SeqAIJ matrix.
4163 
4164    When d_nz, o_nz parameters are specified, d_nz storage elements are
4165    allocated for every row of the local diagonal submatrix, and o_nz
4166    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4167    One way to choose d_nz and o_nz is to use the max nonzerors per local
4168    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4169    In this case, the values of d_nz,o_nz are:
4170 .vb
4171      proc0 : dnz = 2, o_nz = 2
4172      proc1 : dnz = 3, o_nz = 2
4173      proc2 : dnz = 1, o_nz = 4
4174 .ve
4175    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4176    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4177    for proc3. i.e we are using 12+15+10=37 storage locations to store
4178    34 values.
4179 
4180    When d_nnz, o_nnz parameters are specified, the storage is specified
4181    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4182    In the above case the values for d_nnz,o_nnz are:
4183 .vb
4184      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4185      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4186      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4187 .ve
4188    Here the space allocated is sum of all the above values i.e 34, and
4189    hence pre-allocation is perfect.
4190 
4191    Level: intermediate
4192 
4193 .keywords: matrix, aij, compressed row, sparse, parallel
4194 
4195 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4196           MPIAIJ, MatCreateMPIAIJWithArrays()
4197 @*/
4198 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)
4199 {
4200   PetscErrorCode ierr;
4201   PetscMPIInt    size;
4202 
4203   PetscFunctionBegin;
4204   ierr = MatCreate(comm,A);CHKERRQ(ierr);
4205   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
4206   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4207   if (size > 1) {
4208     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
4209     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
4210   } else {
4211     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
4212     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
4213   }
4214   PetscFunctionReturn(0);
4215 }
4216 
4217 #undef __FUNCT__
4218 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
4219 PetscErrorCode  MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,const PetscInt *colmap[])
4220 {
4221   Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
4222 
4223   PetscFunctionBegin;
4224   if (Ad)     *Ad     = a->A;
4225   if (Ao)     *Ao     = a->B;
4226   if (colmap) *colmap = a->garray;
4227   PetscFunctionReturn(0);
4228 }
4229 
4230 #undef __FUNCT__
4231 #define __FUNCT__ "MatSetColoring_MPIAIJ"
4232 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
4233 {
4234   PetscErrorCode ierr;
4235   PetscInt       i;
4236   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4237 
4238   PetscFunctionBegin;
4239   if (coloring->ctype == IS_COLORING_GLOBAL) {
4240     ISColoringValue *allcolors,*colors;
4241     ISColoring      ocoloring;
4242 
4243     /* set coloring for diagonal portion */
4244     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
4245 
4246     /* set coloring for off-diagonal portion */
4247     ierr = ISAllGatherColors(PetscObjectComm((PetscObject)A),coloring->n,coloring->colors,NULL,&allcolors);CHKERRQ(ierr);
4248     ierr = PetscMalloc1((a->B->cmap->n+1),&colors);CHKERRQ(ierr);
4249     for (i=0; i<a->B->cmap->n; i++) {
4250       colors[i] = allcolors[a->garray[i]];
4251     }
4252     ierr = PetscFree(allcolors);CHKERRQ(ierr);
4253     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4254     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4255     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4256   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
4257     ISColoringValue *colors;
4258     PetscInt        *larray;
4259     ISColoring      ocoloring;
4260 
4261     /* set coloring for diagonal portion */
4262     ierr = PetscMalloc1((a->A->cmap->n+1),&larray);CHKERRQ(ierr);
4263     for (i=0; i<a->A->cmap->n; i++) {
4264       larray[i] = i + A->cmap->rstart;
4265     }
4266     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,NULL,larray);CHKERRQ(ierr);
4267     ierr = PetscMalloc1((a->A->cmap->n+1),&colors);CHKERRQ(ierr);
4268     for (i=0; i<a->A->cmap->n; i++) {
4269       colors[i] = coloring->colors[larray[i]];
4270     }
4271     ierr = PetscFree(larray);CHKERRQ(ierr);
4272     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4273     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
4274     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4275 
4276     /* set coloring for off-diagonal portion */
4277     ierr = PetscMalloc1((a->B->cmap->n+1),&larray);CHKERRQ(ierr);
4278     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,NULL,larray);CHKERRQ(ierr);
4279     ierr = PetscMalloc1((a->B->cmap->n+1),&colors);CHKERRQ(ierr);
4280     for (i=0; i<a->B->cmap->n; i++) {
4281       colors[i] = coloring->colors[larray[i]];
4282     }
4283     ierr = PetscFree(larray);CHKERRQ(ierr);
4284     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4285     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4286     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4287   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
4288   PetscFunctionReturn(0);
4289 }
4290 
4291 #undef __FUNCT__
4292 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
4293 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
4294 {
4295   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4296   PetscErrorCode ierr;
4297 
4298   PetscFunctionBegin;
4299   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
4300   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
4301   PetscFunctionReturn(0);
4302 }
4303 
4304 #undef __FUNCT__
4305 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJSymbolic"
4306 PetscErrorCode MatCreateMPIAIJConcatenateSeqAIJSymbolic(MPI_Comm comm,Mat inmat,PetscInt n,Mat *outmat)
4307 {
4308   PetscErrorCode ierr;
4309   PetscInt       m,N,i,rstart,nnz,*dnz,*onz,sum,bs,cbs;
4310   PetscInt       *indx;
4311 
4312   PetscFunctionBegin;
4313   /* This routine will ONLY return MPIAIJ type matrix */
4314   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4315   ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
4316   if (n == PETSC_DECIDE) {
4317     ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
4318   }
4319   /* Check sum(n) = N */
4320   ierr = MPI_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4321   if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
4322 
4323   ierr    = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4324   rstart -= m;
4325 
4326   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4327   for (i=0; i<m; i++) {
4328     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4329     ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
4330     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4331   }
4332 
4333   ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
4334   ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4335   ierr = MatSetBlockSizes(*outmat,bs,cbs);CHKERRQ(ierr);
4336   ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
4337   ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
4338   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4339   PetscFunctionReturn(0);
4340 }
4341 
4342 #undef __FUNCT__
4343 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJNumeric"
4344 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJNumeric(MPI_Comm comm,Mat inmat,PetscInt n,Mat outmat)
4345 {
4346   PetscErrorCode ierr;
4347   PetscInt       m,N,i,rstart,nnz,Ii;
4348   PetscInt       *indx;
4349   PetscScalar    *values;
4350 
4351   PetscFunctionBegin;
4352   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4353   ierr = MatGetOwnershipRange(outmat,&rstart,NULL);CHKERRQ(ierr);
4354   for (i=0; i<m; i++) {
4355     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4356     Ii   = i + rstart;
4357     ierr = MatSetValues(outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4358     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4359   }
4360   ierr = MatAssemblyBegin(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4361   ierr = MatAssemblyEnd(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4362   PetscFunctionReturn(0);
4363 }
4364 
4365 #undef __FUNCT__
4366 #define __FUNCT__ "MatCreateMPIMatConcatenateSeqMat_MPIAIJ"
4367 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_MPIAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
4368 {
4369   PetscErrorCode ierr;
4370   PetscMPIInt    size;
4371 
4372   PetscFunctionBegin;
4373   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4374   ierr = PetscLogEventBegin(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4375   if (size == 1) {
4376     if (scall == MAT_INITIAL_MATRIX) {
4377       ierr = MatDuplicate(inmat,MAT_COPY_VALUES,outmat);CHKERRQ(ierr);
4378     } else {
4379       ierr = MatCopy(inmat,*outmat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4380     }
4381   } else {
4382     if (scall == MAT_INITIAL_MATRIX) {
4383       ierr = MatCreateMPIAIJConcatenateSeqAIJSymbolic(comm,inmat,n,outmat);CHKERRQ(ierr);
4384     }
4385     ierr = MatCreateMPIAIJConcatenateSeqAIJNumeric(comm,inmat,n,*outmat);CHKERRQ(ierr);
4386   }
4387   ierr = PetscLogEventEnd(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4388   PetscFunctionReturn(0);
4389 }
4390 
4391 #undef __FUNCT__
4392 #define __FUNCT__ "MatFileSplit"
4393 PetscErrorCode MatFileSplit(Mat A,char *outfile)
4394 {
4395   PetscErrorCode    ierr;
4396   PetscMPIInt       rank;
4397   PetscInt          m,N,i,rstart,nnz;
4398   size_t            len;
4399   const PetscInt    *indx;
4400   PetscViewer       out;
4401   char              *name;
4402   Mat               B;
4403   const PetscScalar *values;
4404 
4405   PetscFunctionBegin;
4406   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
4407   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
4408   /* Should this be the type of the diagonal block of A? */
4409   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
4410   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
4411   ierr = MatSetBlockSizesFromMats(B,A,A);CHKERRQ(ierr);
4412   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
4413   ierr = MatSeqAIJSetPreallocation(B,0,NULL);CHKERRQ(ierr);
4414   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
4415   for (i=0; i<m; i++) {
4416     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4417     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4418     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4419   }
4420   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4421   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4422 
4423   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
4424   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
4425   ierr = PetscMalloc1((len+5),&name);CHKERRQ(ierr);
4426   sprintf(name,"%s.%d",outfile,rank);
4427   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
4428   ierr = PetscFree(name);CHKERRQ(ierr);
4429   ierr = MatView(B,out);CHKERRQ(ierr);
4430   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
4431   ierr = MatDestroy(&B);CHKERRQ(ierr);
4432   PetscFunctionReturn(0);
4433 }
4434 
4435 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
4436 #undef __FUNCT__
4437 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
4438 PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
4439 {
4440   PetscErrorCode      ierr;
4441   Mat_Merge_SeqsToMPI *merge;
4442   PetscContainer      container;
4443 
4444   PetscFunctionBegin;
4445   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4446   if (container) {
4447     ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4448     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
4449     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
4450     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
4451     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
4452     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
4453     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
4454     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
4455     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
4456     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
4457     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
4458     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
4459     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
4460     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
4461     ierr = PetscFree(merge);CHKERRQ(ierr);
4462     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
4463   }
4464   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
4465   PetscFunctionReturn(0);
4466 }
4467 
4468 #include <../src/mat/utils/freespace.h>
4469 #include <petscbt.h>
4470 
4471 #undef __FUNCT__
4472 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJNumeric"
4473 PetscErrorCode  MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
4474 {
4475   PetscErrorCode      ierr;
4476   MPI_Comm            comm;
4477   Mat_SeqAIJ          *a  =(Mat_SeqAIJ*)seqmat->data;
4478   PetscMPIInt         size,rank,taga,*len_s;
4479   PetscInt            N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj;
4480   PetscInt            proc,m;
4481   PetscInt            **buf_ri,**buf_rj;
4482   PetscInt            k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
4483   PetscInt            nrows,**buf_ri_k,**nextrow,**nextai;
4484   MPI_Request         *s_waits,*r_waits;
4485   MPI_Status          *status;
4486   MatScalar           *aa=a->a;
4487   MatScalar           **abuf_r,*ba_i;
4488   Mat_Merge_SeqsToMPI *merge;
4489   PetscContainer      container;
4490 
4491   PetscFunctionBegin;
4492   ierr = PetscObjectGetComm((PetscObject)mpimat,&comm);CHKERRQ(ierr);
4493   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4494 
4495   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4496   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4497 
4498   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4499   ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4500 
4501   bi     = merge->bi;
4502   bj     = merge->bj;
4503   buf_ri = merge->buf_ri;
4504   buf_rj = merge->buf_rj;
4505 
4506   ierr   = PetscMalloc1(size,&status);CHKERRQ(ierr);
4507   owners = merge->rowmap->range;
4508   len_s  = merge->len_s;
4509 
4510   /* send and recv matrix values */
4511   /*-----------------------------*/
4512   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
4513   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
4514 
4515   ierr = PetscMalloc1((merge->nsend+1),&s_waits);CHKERRQ(ierr);
4516   for (proc=0,k=0; proc<size; proc++) {
4517     if (!len_s[proc]) continue;
4518     i    = owners[proc];
4519     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4520     k++;
4521   }
4522 
4523   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4524   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4525   ierr = PetscFree(status);CHKERRQ(ierr);
4526 
4527   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4528   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4529 
4530   /* insert mat values of mpimat */
4531   /*----------------------------*/
4532   ierr = PetscMalloc1(N,&ba_i);CHKERRQ(ierr);
4533   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4534 
4535   for (k=0; k<merge->nrecv; k++) {
4536     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4537     nrows       = *(buf_ri_k[k]);
4538     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4539     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4540   }
4541 
4542   /* set values of ba */
4543   m = merge->rowmap->n;
4544   for (i=0; i<m; i++) {
4545     arow = owners[rank] + i;
4546     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4547     bnzi = bi[i+1] - bi[i];
4548     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4549 
4550     /* add local non-zero vals of this proc's seqmat into ba */
4551     anzi   = ai[arow+1] - ai[arow];
4552     aj     = a->j + ai[arow];
4553     aa     = a->a + ai[arow];
4554     nextaj = 0;
4555     for (j=0; nextaj<anzi; j++) {
4556       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4557         ba_i[j] += aa[nextaj++];
4558       }
4559     }
4560 
4561     /* add received vals into ba */
4562     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4563       /* i-th row */
4564       if (i == *nextrow[k]) {
4565         anzi   = *(nextai[k]+1) - *nextai[k];
4566         aj     = buf_rj[k] + *(nextai[k]);
4567         aa     = abuf_r[k] + *(nextai[k]);
4568         nextaj = 0;
4569         for (j=0; nextaj<anzi; j++) {
4570           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4571             ba_i[j] += aa[nextaj++];
4572           }
4573         }
4574         nextrow[k]++; nextai[k]++;
4575       }
4576     }
4577     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4578   }
4579   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4580   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4581 
4582   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4583   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4584   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4585   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4586   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4587   PetscFunctionReturn(0);
4588 }
4589 
4590 extern PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat);
4591 
4592 #undef __FUNCT__
4593 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJSymbolic"
4594 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4595 {
4596   PetscErrorCode      ierr;
4597   Mat                 B_mpi;
4598   Mat_SeqAIJ          *a=(Mat_SeqAIJ*)seqmat->data;
4599   PetscMPIInt         size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4600   PetscInt            **buf_rj,**buf_ri,**buf_ri_k;
4601   PetscInt            M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4602   PetscInt            len,proc,*dnz,*onz,bs,cbs;
4603   PetscInt            k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4604   PetscInt            nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4605   MPI_Request         *si_waits,*sj_waits,*ri_waits,*rj_waits;
4606   MPI_Status          *status;
4607   PetscFreeSpaceList  free_space=NULL,current_space=NULL;
4608   PetscBT             lnkbt;
4609   Mat_Merge_SeqsToMPI *merge;
4610   PetscContainer      container;
4611 
4612   PetscFunctionBegin;
4613   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4614 
4615   /* make sure it is a PETSc comm */
4616   ierr = PetscCommDuplicate(comm,&comm,NULL);CHKERRQ(ierr);
4617   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4618   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4619 
4620   ierr = PetscNew(&merge);CHKERRQ(ierr);
4621   ierr = PetscMalloc1(size,&status);CHKERRQ(ierr);
4622 
4623   /* determine row ownership */
4624   /*---------------------------------------------------------*/
4625   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4626   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4627   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4628   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4629   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4630   ierr = PetscMalloc1(size,&len_si);CHKERRQ(ierr);
4631   ierr = PetscMalloc1(size,&merge->len_s);CHKERRQ(ierr);
4632 
4633   m      = merge->rowmap->n;
4634   owners = merge->rowmap->range;
4635 
4636   /* determine the number of messages to send, their lengths */
4637   /*---------------------------------------------------------*/
4638   len_s = merge->len_s;
4639 
4640   len          = 0; /* length of buf_si[] */
4641   merge->nsend = 0;
4642   for (proc=0; proc<size; proc++) {
4643     len_si[proc] = 0;
4644     if (proc == rank) {
4645       len_s[proc] = 0;
4646     } else {
4647       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4648       len_s[proc]  = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4649     }
4650     if (len_s[proc]) {
4651       merge->nsend++;
4652       nrows = 0;
4653       for (i=owners[proc]; i<owners[proc+1]; i++) {
4654         if (ai[i+1] > ai[i]) nrows++;
4655       }
4656       len_si[proc] = 2*(nrows+1);
4657       len         += len_si[proc];
4658     }
4659   }
4660 
4661   /* determine the number and length of messages to receive for ij-structure */
4662   /*-------------------------------------------------------------------------*/
4663   ierr = PetscGatherNumberOfMessages(comm,NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4664   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4665 
4666   /* post the Irecv of j-structure */
4667   /*-------------------------------*/
4668   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4669   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4670 
4671   /* post the Isend of j-structure */
4672   /*--------------------------------*/
4673   ierr = PetscMalloc2(merge->nsend,&si_waits,merge->nsend,&sj_waits);CHKERRQ(ierr);
4674 
4675   for (proc=0, k=0; proc<size; proc++) {
4676     if (!len_s[proc]) continue;
4677     i    = owners[proc];
4678     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4679     k++;
4680   }
4681 
4682   /* receives and sends of j-structure are complete */
4683   /*------------------------------------------------*/
4684   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4685   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4686 
4687   /* send and recv i-structure */
4688   /*---------------------------*/
4689   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4690   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4691 
4692   ierr   = PetscMalloc1((len+1),&buf_s);CHKERRQ(ierr);
4693   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4694   for (proc=0,k=0; proc<size; proc++) {
4695     if (!len_s[proc]) continue;
4696     /* form outgoing message for i-structure:
4697          buf_si[0]:                 nrows to be sent
4698                [1:nrows]:           row index (global)
4699                [nrows+1:2*nrows+1]: i-structure index
4700     */
4701     /*-------------------------------------------*/
4702     nrows       = len_si[proc]/2 - 1;
4703     buf_si_i    = buf_si + nrows+1;
4704     buf_si[0]   = nrows;
4705     buf_si_i[0] = 0;
4706     nrows       = 0;
4707     for (i=owners[proc]; i<owners[proc+1]; i++) {
4708       anzi = ai[i+1] - ai[i];
4709       if (anzi) {
4710         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4711         buf_si[nrows+1]   = i-owners[proc]; /* local row index */
4712         nrows++;
4713       }
4714     }
4715     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4716     k++;
4717     buf_si += len_si[proc];
4718   }
4719 
4720   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4721   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4722 
4723   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4724   for (i=0; i<merge->nrecv; i++) {
4725     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);
4726   }
4727 
4728   ierr = PetscFree(len_si);CHKERRQ(ierr);
4729   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4730   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4731   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4732   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4733   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4734   ierr = PetscFree(status);CHKERRQ(ierr);
4735 
4736   /* compute a local seq matrix in each processor */
4737   /*----------------------------------------------*/
4738   /* allocate bi array and free space for accumulating nonzero column info */
4739   ierr  = PetscMalloc1((m+1),&bi);CHKERRQ(ierr);
4740   bi[0] = 0;
4741 
4742   /* create and initialize a linked list */
4743   nlnk = N+1;
4744   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4745 
4746   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4747   len  = ai[owners[rank+1]] - ai[owners[rank]];
4748   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4749 
4750   current_space = free_space;
4751 
4752   /* determine symbolic info for each local row */
4753   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4754 
4755   for (k=0; k<merge->nrecv; k++) {
4756     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4757     nrows       = *buf_ri_k[k];
4758     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4759     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4760   }
4761 
4762   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4763   len  = 0;
4764   for (i=0; i<m; i++) {
4765     bnzi = 0;
4766     /* add local non-zero cols of this proc's seqmat into lnk */
4767     arow  = owners[rank] + i;
4768     anzi  = ai[arow+1] - ai[arow];
4769     aj    = a->j + ai[arow];
4770     ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4771     bnzi += nlnk;
4772     /* add received col data into lnk */
4773     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4774       if (i == *nextrow[k]) { /* i-th row */
4775         anzi  = *(nextai[k]+1) - *nextai[k];
4776         aj    = buf_rj[k] + *nextai[k];
4777         ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4778         bnzi += nlnk;
4779         nextrow[k]++; nextai[k]++;
4780       }
4781     }
4782     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4783 
4784     /* if free space is not available, make more free space */
4785     if (current_space->local_remaining<bnzi) {
4786       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4787       nspacedouble++;
4788     }
4789     /* copy data into free space, then initialize lnk */
4790     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4791     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4792 
4793     current_space->array           += bnzi;
4794     current_space->local_used      += bnzi;
4795     current_space->local_remaining -= bnzi;
4796 
4797     bi[i+1] = bi[i] + bnzi;
4798   }
4799 
4800   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4801 
4802   ierr = PetscMalloc1((bi[m]+1),&bj);CHKERRQ(ierr);
4803   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4804   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4805 
4806   /* create symbolic parallel matrix B_mpi */
4807   /*---------------------------------------*/
4808   ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
4809   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4810   if (n==PETSC_DECIDE) {
4811     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4812   } else {
4813     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4814   }
4815   ierr = MatSetBlockSizes(B_mpi,bs,cbs);CHKERRQ(ierr);
4816   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4817   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4818   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4819   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
4820 
4821   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
4822   B_mpi->assembled    = PETSC_FALSE;
4823   B_mpi->ops->destroy = MatDestroy_MPIAIJ_SeqsToMPI;
4824   merge->bi           = bi;
4825   merge->bj           = bj;
4826   merge->buf_ri       = buf_ri;
4827   merge->buf_rj       = buf_rj;
4828   merge->coi          = NULL;
4829   merge->coj          = NULL;
4830   merge->owners_co    = NULL;
4831 
4832   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4833 
4834   /* attach the supporting struct to B_mpi for reuse */
4835   ierr    = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4836   ierr    = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4837   ierr    = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4838   ierr    = PetscContainerDestroy(&container);CHKERRQ(ierr);
4839   *mpimat = B_mpi;
4840 
4841   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4842   PetscFunctionReturn(0);
4843 }
4844 
4845 #undef __FUNCT__
4846 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJ"
4847 /*@C
4848       MatCreateMPIAIJSumSeqAIJ - Creates a MPIAIJ matrix by adding sequential
4849                  matrices from each processor
4850 
4851     Collective on MPI_Comm
4852 
4853    Input Parameters:
4854 +    comm - the communicators the parallel matrix will live on
4855 .    seqmat - the input sequential matrices
4856 .    m - number of local rows (or PETSC_DECIDE)
4857 .    n - number of local columns (or PETSC_DECIDE)
4858 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4859 
4860    Output Parameter:
4861 .    mpimat - the parallel matrix generated
4862 
4863     Level: advanced
4864 
4865    Notes:
4866      The dimensions of the sequential matrix in each processor MUST be the same.
4867      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
4868      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
4869 @*/
4870 PetscErrorCode  MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4871 {
4872   PetscErrorCode ierr;
4873   PetscMPIInt    size;
4874 
4875   PetscFunctionBegin;
4876   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4877   if (size == 1) {
4878     ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4879     if (scall == MAT_INITIAL_MATRIX) {
4880       ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
4881     } else {
4882       ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4883     }
4884     ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4885     PetscFunctionReturn(0);
4886   }
4887   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4888   if (scall == MAT_INITIAL_MATRIX) {
4889     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4890   }
4891   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
4892   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4893   PetscFunctionReturn(0);
4894 }
4895 
4896 #undef __FUNCT__
4897 #define __FUNCT__ "MatMPIAIJGetLocalMat"
4898 /*@
4899      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
4900           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
4901           with MatGetSize()
4902 
4903     Not Collective
4904 
4905    Input Parameters:
4906 +    A - the matrix
4907 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4908 
4909    Output Parameter:
4910 .    A_loc - the local sequential matrix generated
4911 
4912     Level: developer
4913 
4914 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
4915 
4916 @*/
4917 PetscErrorCode  MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4918 {
4919   PetscErrorCode ierr;
4920   Mat_MPIAIJ     *mpimat=(Mat_MPIAIJ*)A->data;
4921   Mat_SeqAIJ     *mat,*a,*b;
4922   PetscInt       *ai,*aj,*bi,*bj,*cmap=mpimat->garray;
4923   MatScalar      *aa,*ba,*cam;
4924   PetscScalar    *ca;
4925   PetscInt       am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4926   PetscInt       *ci,*cj,col,ncols_d,ncols_o,jo;
4927   PetscBool      match;
4928   MPI_Comm       comm;
4929   PetscMPIInt    size;
4930 
4931   PetscFunctionBegin;
4932   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4933   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
4934   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
4935   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4936   if (size == 1 && scall == MAT_REUSE_MATRIX) PetscFunctionReturn(0);
4937 
4938   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4939   a = (Mat_SeqAIJ*)(mpimat->A)->data;
4940   b = (Mat_SeqAIJ*)(mpimat->B)->data;
4941   ai = a->i; aj = a->j; bi = b->i; bj = b->j;
4942   aa = a->a; ba = b->a;
4943   if (scall == MAT_INITIAL_MATRIX) {
4944     if (size == 1) {
4945       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ai,aj,aa,A_loc);CHKERRQ(ierr);
4946       PetscFunctionReturn(0);
4947     }
4948 
4949     ierr  = PetscMalloc1((1+am),&ci);CHKERRQ(ierr);
4950     ci[0] = 0;
4951     for (i=0; i<am; i++) {
4952       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4953     }
4954     ierr = PetscMalloc1((1+ci[am]),&cj);CHKERRQ(ierr);
4955     ierr = PetscMalloc1((1+ci[am]),&ca);CHKERRQ(ierr);
4956     k    = 0;
4957     for (i=0; i<am; i++) {
4958       ncols_o = bi[i+1] - bi[i];
4959       ncols_d = ai[i+1] - ai[i];
4960       /* off-diagonal portion of A */
4961       for (jo=0; jo<ncols_o; jo++) {
4962         col = cmap[*bj];
4963         if (col >= cstart) break;
4964         cj[k]   = col; bj++;
4965         ca[k++] = *ba++;
4966       }
4967       /* diagonal portion of A */
4968       for (j=0; j<ncols_d; j++) {
4969         cj[k]   = cstart + *aj++;
4970         ca[k++] = *aa++;
4971       }
4972       /* off-diagonal portion of A */
4973       for (j=jo; j<ncols_o; j++) {
4974         cj[k]   = cmap[*bj++];
4975         ca[k++] = *ba++;
4976       }
4977     }
4978     /* put together the new matrix */
4979     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4980     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4981     /* Since these are PETSc arrays, change flags to free them as necessary. */
4982     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4983     mat->free_a  = PETSC_TRUE;
4984     mat->free_ij = PETSC_TRUE;
4985     mat->nonew   = 0;
4986   } else if (scall == MAT_REUSE_MATRIX) {
4987     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4988     ci = mat->i; cj = mat->j; cam = mat->a;
4989     for (i=0; i<am; i++) {
4990       /* off-diagonal portion of A */
4991       ncols_o = bi[i+1] - bi[i];
4992       for (jo=0; jo<ncols_o; jo++) {
4993         col = cmap[*bj];
4994         if (col >= cstart) break;
4995         *cam++ = *ba++; bj++;
4996       }
4997       /* diagonal portion of A */
4998       ncols_d = ai[i+1] - ai[i];
4999       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
5000       /* off-diagonal portion of A */
5001       for (j=jo; j<ncols_o; j++) {
5002         *cam++ = *ba++; bj++;
5003       }
5004     }
5005   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
5006   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
5007   PetscFunctionReturn(0);
5008 }
5009 
5010 #undef __FUNCT__
5011 #define __FUNCT__ "MatMPIAIJGetLocalMatCondensed"
5012 /*@C
5013      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MPIAIJ matrix by taking all its local rows and NON-ZERO columns
5014 
5015     Not Collective
5016 
5017    Input Parameters:
5018 +    A - the matrix
5019 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5020 -    row, col - index sets of rows and columns to extract (or NULL)
5021 
5022    Output Parameter:
5023 .    A_loc - the local sequential matrix generated
5024 
5025     Level: developer
5026 
5027 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
5028 
5029 @*/
5030 PetscErrorCode  MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
5031 {
5032   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5033   PetscErrorCode ierr;
5034   PetscInt       i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
5035   IS             isrowa,iscola;
5036   Mat            *aloc;
5037   PetscBool      match;
5038 
5039   PetscFunctionBegin;
5040   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
5041   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
5042   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5043   if (!row) {
5044     start = A->rmap->rstart; end = A->rmap->rend;
5045     ierr  = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
5046   } else {
5047     isrowa = *row;
5048   }
5049   if (!col) {
5050     start = A->cmap->rstart;
5051     cmap  = a->garray;
5052     nzA   = a->A->cmap->n;
5053     nzB   = a->B->cmap->n;
5054     ierr  = PetscMalloc1((nzA+nzB), &idx);CHKERRQ(ierr);
5055     ncols = 0;
5056     for (i=0; i<nzB; i++) {
5057       if (cmap[i] < start) idx[ncols++] = cmap[i];
5058       else break;
5059     }
5060     imark = i;
5061     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
5062     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
5063     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
5064   } else {
5065     iscola = *col;
5066   }
5067   if (scall != MAT_INITIAL_MATRIX) {
5068     ierr    = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
5069     aloc[0] = *A_loc;
5070   }
5071   ierr   = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
5072   *A_loc = aloc[0];
5073   ierr   = PetscFree(aloc);CHKERRQ(ierr);
5074   if (!row) {
5075     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
5076   }
5077   if (!col) {
5078     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
5079   }
5080   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5081   PetscFunctionReturn(0);
5082 }
5083 
5084 #undef __FUNCT__
5085 #define __FUNCT__ "MatGetBrowsOfAcols"
5086 /*@C
5087     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
5088 
5089     Collective on Mat
5090 
5091    Input Parameters:
5092 +    A,B - the matrices in mpiaij format
5093 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5094 -    rowb, colb - index sets of rows and columns of B to extract (or NULL)
5095 
5096    Output Parameter:
5097 +    rowb, colb - index sets of rows and columns of B to extract
5098 -    B_seq - the sequential matrix generated
5099 
5100     Level: developer
5101 
5102 @*/
5103 PetscErrorCode  MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
5104 {
5105   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5106   PetscErrorCode ierr;
5107   PetscInt       *idx,i,start,ncols,nzA,nzB,*cmap,imark;
5108   IS             isrowb,iscolb;
5109   Mat            *bseq=NULL;
5110 
5111   PetscFunctionBegin;
5112   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5113     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);
5114   }
5115   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5116 
5117   if (scall == MAT_INITIAL_MATRIX) {
5118     start = A->cmap->rstart;
5119     cmap  = a->garray;
5120     nzA   = a->A->cmap->n;
5121     nzB   = a->B->cmap->n;
5122     ierr  = PetscMalloc1((nzA+nzB), &idx);CHKERRQ(ierr);
5123     ncols = 0;
5124     for (i=0; i<nzB; i++) {  /* row < local row index */
5125       if (cmap[i] < start) idx[ncols++] = cmap[i];
5126       else break;
5127     }
5128     imark = i;
5129     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
5130     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5131     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
5132     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
5133   } else {
5134     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5135     isrowb  = *rowb; iscolb = *colb;
5136     ierr    = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
5137     bseq[0] = *B_seq;
5138   }
5139   ierr   = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
5140   *B_seq = bseq[0];
5141   ierr   = PetscFree(bseq);CHKERRQ(ierr);
5142   if (!rowb) {
5143     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
5144   } else {
5145     *rowb = isrowb;
5146   }
5147   if (!colb) {
5148     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
5149   } else {
5150     *colb = iscolb;
5151   }
5152   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5153   PetscFunctionReturn(0);
5154 }
5155 
5156 #undef __FUNCT__
5157 #define __FUNCT__ "MatGetBrowsOfAoCols_MPIAIJ"
5158 /*
5159     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
5160     of the OFF-DIAGONAL portion of local A
5161 
5162     Collective on Mat
5163 
5164    Input Parameters:
5165 +    A,B - the matrices in mpiaij format
5166 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5167 
5168    Output Parameter:
5169 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
5170 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
5171 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
5172 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
5173 
5174     Level: developer
5175 
5176 */
5177 PetscErrorCode  MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
5178 {
5179   VecScatter_MPI_General *gen_to,*gen_from;
5180   PetscErrorCode         ierr;
5181   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
5182   Mat_SeqAIJ             *b_oth;
5183   VecScatter             ctx =a->Mvctx;
5184   MPI_Comm               comm;
5185   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
5186   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
5187   PetscScalar            *rvalues,*svalues;
5188   MatScalar              *b_otha,*bufa,*bufA;
5189   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
5190   MPI_Request            *rwaits = NULL,*swaits = NULL;
5191   MPI_Status             *sstatus,rstatus;
5192   PetscMPIInt            jj,size;
5193   PetscInt               *cols,sbs,rbs;
5194   PetscScalar            *vals;
5195 
5196   PetscFunctionBegin;
5197   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
5198   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
5199   if (size == 1) PetscFunctionReturn(0);
5200 
5201   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5202     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);
5203   }
5204   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5205   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
5206 
5207   gen_to   = (VecScatter_MPI_General*)ctx->todata;
5208   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
5209   rvalues  = gen_from->values; /* holds the length of receiving row */
5210   svalues  = gen_to->values;   /* holds the length of sending row */
5211   nrecvs   = gen_from->n;
5212   nsends   = gen_to->n;
5213 
5214   ierr    = PetscMalloc2(nrecvs,&rwaits,nsends,&swaits);CHKERRQ(ierr);
5215   srow    = gen_to->indices;    /* local row index to be sent */
5216   sstarts = gen_to->starts;
5217   sprocs  = gen_to->procs;
5218   sstatus = gen_to->sstatus;
5219   sbs     = gen_to->bs;
5220   rstarts = gen_from->starts;
5221   rprocs  = gen_from->procs;
5222   rbs     = gen_from->bs;
5223 
5224   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5225   if (scall == MAT_INITIAL_MATRIX) {
5226     /* i-array */
5227     /*---------*/
5228     /*  post receives */
5229     for (i=0; i<nrecvs; i++) {
5230       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5231       nrows  = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
5232       ierr   = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5233     }
5234 
5235     /* pack the outgoing message */
5236     ierr = PetscMalloc2(nsends+1,&sstartsj,nrecvs+1,&rstartsj);CHKERRQ(ierr);
5237 
5238     sstartsj[0] = 0;
5239     rstartsj[0] = 0;
5240     len         = 0; /* total length of j or a array to be sent */
5241     k           = 0;
5242     for (i=0; i<nsends; i++) {
5243       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
5244       nrows  = sstarts[i+1]-sstarts[i]; /* num of block rows */
5245       for (j=0; j<nrows; j++) {
5246         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5247         for (l=0; l<sbs; l++) {
5248           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr); /* rowlength */
5249 
5250           rowlen[j*sbs+l] = ncols;
5251 
5252           len += ncols;
5253           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr);
5254         }
5255         k++;
5256       }
5257       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5258 
5259       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5260     }
5261     /* recvs and sends of i-array are completed */
5262     i = nrecvs;
5263     while (i--) {
5264       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5265     }
5266     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5267 
5268     /* allocate buffers for sending j and a arrays */
5269     ierr = PetscMalloc1((len+1),&bufj);CHKERRQ(ierr);
5270     ierr = PetscMalloc1((len+1),&bufa);CHKERRQ(ierr);
5271 
5272     /* create i-array of B_oth */
5273     ierr = PetscMalloc1((aBn+2),&b_othi);CHKERRQ(ierr);
5274 
5275     b_othi[0] = 0;
5276     len       = 0; /* total length of j or a array to be received */
5277     k         = 0;
5278     for (i=0; i<nrecvs; i++) {
5279       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5280       nrows  = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
5281       for (j=0; j<nrows; j++) {
5282         b_othi[k+1] = b_othi[k] + rowlen[j];
5283         len        += rowlen[j]; k++;
5284       }
5285       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5286     }
5287 
5288     /* allocate space for j and a arrrays of B_oth */
5289     ierr = PetscMalloc1((b_othi[aBn]+1),&b_othj);CHKERRQ(ierr);
5290     ierr = PetscMalloc1((b_othi[aBn]+1),&b_otha);CHKERRQ(ierr);
5291 
5292     /* j-array */
5293     /*---------*/
5294     /*  post receives of j-array */
5295     for (i=0; i<nrecvs; i++) {
5296       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5297       ierr  = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5298     }
5299 
5300     /* pack the outgoing message j-array */
5301     k = 0;
5302     for (i=0; i<nsends; i++) {
5303       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5304       bufJ  = bufj+sstartsj[i];
5305       for (j=0; j<nrows; j++) {
5306         row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5307         for (ll=0; ll<sbs; ll++) {
5308           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5309           for (l=0; l<ncols; l++) {
5310             *bufJ++ = cols[l];
5311           }
5312           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5313         }
5314       }
5315       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5316     }
5317 
5318     /* recvs and sends of j-array are completed */
5319     i = nrecvs;
5320     while (i--) {
5321       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5322     }
5323     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5324   } else if (scall == MAT_REUSE_MATRIX) {
5325     sstartsj = *startsj_s;
5326     rstartsj = *startsj_r;
5327     bufa     = *bufa_ptr;
5328     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
5329     b_otha   = b_oth->a;
5330   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
5331 
5332   /* a-array */
5333   /*---------*/
5334   /*  post receives of a-array */
5335   for (i=0; i<nrecvs; i++) {
5336     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5337     ierr  = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5338   }
5339 
5340   /* pack the outgoing message a-array */
5341   k = 0;
5342   for (i=0; i<nsends; i++) {
5343     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5344     bufA  = bufa+sstartsj[i];
5345     for (j=0; j<nrows; j++) {
5346       row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5347       for (ll=0; ll<sbs; ll++) {
5348         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5349         for (l=0; l<ncols; l++) {
5350           *bufA++ = vals[l];
5351         }
5352         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5353       }
5354     }
5355     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5356   }
5357   /* recvs and sends of a-array are completed */
5358   i = nrecvs;
5359   while (i--) {
5360     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5361   }
5362   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5363   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
5364 
5365   if (scall == MAT_INITIAL_MATRIX) {
5366     /* put together the new matrix */
5367     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
5368 
5369     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5370     /* Since these are PETSc arrays, change flags to free them as necessary. */
5371     b_oth          = (Mat_SeqAIJ*)(*B_oth)->data;
5372     b_oth->free_a  = PETSC_TRUE;
5373     b_oth->free_ij = PETSC_TRUE;
5374     b_oth->nonew   = 0;
5375 
5376     ierr = PetscFree(bufj);CHKERRQ(ierr);
5377     if (!startsj_s || !bufa_ptr) {
5378       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
5379       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
5380     } else {
5381       *startsj_s = sstartsj;
5382       *startsj_r = rstartsj;
5383       *bufa_ptr  = bufa;
5384     }
5385   }
5386   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5387   PetscFunctionReturn(0);
5388 }
5389 
5390 #undef __FUNCT__
5391 #define __FUNCT__ "MatGetCommunicationStructs"
5392 /*@C
5393   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
5394 
5395   Not Collective
5396 
5397   Input Parameters:
5398 . A - The matrix in mpiaij format
5399 
5400   Output Parameter:
5401 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
5402 . colmap - A map from global column index to local index into lvec
5403 - multScatter - A scatter from the argument of a matrix-vector product to lvec
5404 
5405   Level: developer
5406 
5407 @*/
5408 #if defined(PETSC_USE_CTABLE)
5409 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
5410 #else
5411 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
5412 #endif
5413 {
5414   Mat_MPIAIJ *a;
5415 
5416   PetscFunctionBegin;
5417   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
5418   PetscValidPointer(lvec, 2);
5419   PetscValidPointer(colmap, 3);
5420   PetscValidPointer(multScatter, 4);
5421   a = (Mat_MPIAIJ*) A->data;
5422   if (lvec) *lvec = a->lvec;
5423   if (colmap) *colmap = a->colmap;
5424   if (multScatter) *multScatter = a->Mvctx;
5425   PetscFunctionReturn(0);
5426 }
5427 
5428 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat,MatType,MatReuse,Mat*);
5429 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat,MatType,MatReuse,Mat*);
5430 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat,MatType,MatReuse,Mat*);
5431 #if defined(PETSC_HAVE_ELEMENTAL)
5432 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat,MatType,MatReuse,Mat*);
5433 #endif
5434 
5435 #undef __FUNCT__
5436 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
5437 /*
5438     Computes (B'*A')' since computing B*A directly is untenable
5439 
5440                n                       p                          p
5441         (              )       (              )         (                  )
5442       m (      A       )  *  n (       B      )   =   m (         C        )
5443         (              )       (              )         (                  )
5444 
5445 */
5446 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
5447 {
5448   PetscErrorCode ierr;
5449   Mat            At,Bt,Ct;
5450 
5451   PetscFunctionBegin;
5452   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
5453   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
5454   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
5455   ierr = MatDestroy(&At);CHKERRQ(ierr);
5456   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
5457   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
5458   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
5459   PetscFunctionReturn(0);
5460 }
5461 
5462 #undef __FUNCT__
5463 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
5464 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
5465 {
5466   PetscErrorCode ierr;
5467   PetscInt       m=A->rmap->n,n=B->cmap->n;
5468   Mat            Cmat;
5469 
5470   PetscFunctionBegin;
5471   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);
5472   ierr = MatCreate(PetscObjectComm((PetscObject)A),&Cmat);CHKERRQ(ierr);
5473   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5474   ierr = MatSetBlockSizesFromMats(Cmat,A,B);CHKERRQ(ierr);
5475   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
5476   ierr = MatMPIDenseSetPreallocation(Cmat,NULL);CHKERRQ(ierr);
5477   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5478   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5479 
5480   Cmat->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
5481 
5482   *C = Cmat;
5483   PetscFunctionReturn(0);
5484 }
5485 
5486 /* ----------------------------------------------------------------*/
5487 #undef __FUNCT__
5488 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
5489 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
5490 {
5491   PetscErrorCode ierr;
5492 
5493   PetscFunctionBegin;
5494   if (scall == MAT_INITIAL_MATRIX) {
5495     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5496     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
5497     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5498   }
5499   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5500   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
5501   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5502   PetscFunctionReturn(0);
5503 }
5504 
5505 #if defined(PETSC_HAVE_MUMPS)
5506 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_mumps(Mat,MatFactorType,Mat*);
5507 #endif
5508 #if defined(PETSC_HAVE_PASTIX)
5509 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
5510 #endif
5511 #if defined(PETSC_HAVE_SUPERLU_DIST)
5512 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
5513 #endif
5514 #if defined(PETSC_HAVE_CLIQUE)
5515 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_clique(Mat,MatFactorType,Mat*);
5516 #endif
5517 
5518 /*MC
5519    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
5520 
5521    Options Database Keys:
5522 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
5523 
5524   Level: beginner
5525 
5526 .seealso: MatCreateAIJ()
5527 M*/
5528 
5529 #undef __FUNCT__
5530 #define __FUNCT__ "MatCreate_MPIAIJ"
5531 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
5532 {
5533   Mat_MPIAIJ     *b;
5534   PetscErrorCode ierr;
5535   PetscMPIInt    size;
5536 
5537   PetscFunctionBegin;
5538   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)B),&size);CHKERRQ(ierr);
5539 
5540   ierr          = PetscNewLog(B,&b);CHKERRQ(ierr);
5541   B->data       = (void*)b;
5542   ierr          = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
5543   B->assembled  = PETSC_FALSE;
5544   B->insertmode = NOT_SET_VALUES;
5545   b->size       = size;
5546 
5547   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)B),&b->rank);CHKERRQ(ierr);
5548 
5549   /* build cache for off array entries formed */
5550   ierr = MatStashCreate_Private(PetscObjectComm((PetscObject)B),1,&B->stash);CHKERRQ(ierr);
5551 
5552   b->donotstash  = PETSC_FALSE;
5553   b->colmap      = 0;
5554   b->garray      = 0;
5555   b->roworiented = PETSC_TRUE;
5556 
5557   /* stuff used for matrix vector multiply */
5558   b->lvec  = NULL;
5559   b->Mvctx = NULL;
5560 
5561   /* stuff for MatGetRow() */
5562   b->rowindices   = 0;
5563   b->rowvalues    = 0;
5564   b->getrowactive = PETSC_FALSE;
5565 
5566   /* flexible pointer used in CUSP/CUSPARSE classes */
5567   b->spptr = NULL;
5568 
5569 #if defined(PETSC_HAVE_MUMPS)
5570   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_mumps_C",MatGetFactor_aij_mumps);CHKERRQ(ierr);
5571 #endif
5572 #if defined(PETSC_HAVE_PASTIX)
5573   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_pastix_C",MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
5574 #endif
5575 #if defined(PETSC_HAVE_SUPERLU_DIST)
5576   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_superlu_dist_C",MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
5577 #endif
5578 #if defined(PETSC_HAVE_CLIQUE)
5579   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_clique_C",MatGetFactor_aij_clique);CHKERRQ(ierr);
5580 #endif
5581   ierr = PetscObjectComposeFunction((PetscObject)B,"MatStoreValues_C",MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5582   ierr = PetscObjectComposeFunction((PetscObject)B,"MatRetrieveValues_C",MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5583   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetDiagonalBlock_C",MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5584   ierr = PetscObjectComposeFunction((PetscObject)B,"MatIsTranspose_C",MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5585   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5586   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5587   ierr = PetscObjectComposeFunction((PetscObject)B,"MatDiagonalScaleLocal_C",MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5588   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
5589   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5590   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5591 #if defined(PETSC_HAVE_ELEMENTAL)
5592   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_elemental_C",MatConvert_MPIAIJ_Elemental);CHKERRQ(ierr);
5593 #endif
5594   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5595   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5596   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5597   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5598   PetscFunctionReturn(0);
5599 }
5600 
5601 #undef __FUNCT__
5602 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5603 /*@
5604      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5605          and "off-diagonal" part of the matrix in CSR format.
5606 
5607    Collective on MPI_Comm
5608 
5609    Input Parameters:
5610 +  comm - MPI communicator
5611 .  m - number of local rows (Cannot be PETSC_DECIDE)
5612 .  n - This value should be the same as the local size used in creating the
5613        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5614        calculated if N is given) For square matrices n is almost always m.
5615 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5616 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5617 .   i - row indices for "diagonal" portion of matrix
5618 .   j - column indices
5619 .   a - matrix values
5620 .   oi - row indices for "off-diagonal" portion of matrix
5621 .   oj - column indices
5622 -   oa - matrix values
5623 
5624    Output Parameter:
5625 .   mat - the matrix
5626 
5627    Level: advanced
5628 
5629    Notes:
5630        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5631        must free the arrays once the matrix has been destroyed and not before.
5632 
5633        The i and j indices are 0 based
5634 
5635        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5636 
5637        This sets local rows and cannot be used to set off-processor values.
5638 
5639        Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
5640        legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
5641        not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
5642        the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
5643        keep track of the underlying array. Use MatSetOption(A,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE) to disable all
5644        communication if it is known that only local entries will be set.
5645 
5646 .keywords: matrix, aij, compressed row, sparse, parallel
5647 
5648 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5649           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5650 @*/
5651 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)
5652 {
5653   PetscErrorCode ierr;
5654   Mat_MPIAIJ     *maij;
5655 
5656   PetscFunctionBegin;
5657   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5658   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5659   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5660   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5661   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5662   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5663   maij = (Mat_MPIAIJ*) (*mat)->data;
5664 
5665   (*mat)->preallocated = PETSC_TRUE;
5666 
5667   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5668   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5669 
5670   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5671   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5672 
5673   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5674   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5675   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5676   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5677 
5678   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5679   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5680   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
5681   PetscFunctionReturn(0);
5682 }
5683 
5684 /*
5685     Special version for direct calls from Fortran
5686 */
5687 #include <petsc-private/fortranimpl.h>
5688 
5689 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5690 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5691 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5692 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5693 #endif
5694 
5695 /* Change these macros so can be used in void function */
5696 #undef CHKERRQ
5697 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5698 #undef SETERRQ2
5699 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5700 #undef SETERRQ3
5701 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5702 #undef SETERRQ
5703 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5704 
5705 #undef __FUNCT__
5706 #define __FUNCT__ "matsetvaluesmpiaij_"
5707 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)
5708 {
5709   Mat            mat  = *mmat;
5710   PetscInt       m    = *mm, n = *mn;
5711   InsertMode     addv = *maddv;
5712   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
5713   PetscScalar    value;
5714   PetscErrorCode ierr;
5715 
5716   MatCheckPreallocated(mat,1);
5717   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
5718 
5719 #if defined(PETSC_USE_DEBUG)
5720   else if (mat->insertmode != addv) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5721 #endif
5722   {
5723     PetscInt  i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
5724     PetscInt  cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5725     PetscBool roworiented = aij->roworiented;
5726 
5727     /* Some Variables required in the macro */
5728     Mat        A                 = aij->A;
5729     Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
5730     PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5731     MatScalar  *aa               = a->a;
5732     PetscBool  ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
5733     Mat        B                 = aij->B;
5734     Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
5735     PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5736     MatScalar  *ba               = b->a;
5737 
5738     PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5739     PetscInt  nonew = a->nonew;
5740     MatScalar *ap1,*ap2;
5741 
5742     PetscFunctionBegin;
5743     for (i=0; i<m; i++) {
5744       if (im[i] < 0) continue;
5745 #if defined(PETSC_USE_DEBUG)
5746       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);
5747 #endif
5748       if (im[i] >= rstart && im[i] < rend) {
5749         row      = im[i] - rstart;
5750         lastcol1 = -1;
5751         rp1      = aj + ai[row];
5752         ap1      = aa + ai[row];
5753         rmax1    = aimax[row];
5754         nrow1    = ailen[row];
5755         low1     = 0;
5756         high1    = nrow1;
5757         lastcol2 = -1;
5758         rp2      = bj + bi[row];
5759         ap2      = ba + bi[row];
5760         rmax2    = bimax[row];
5761         nrow2    = bilen[row];
5762         low2     = 0;
5763         high2    = nrow2;
5764 
5765         for (j=0; j<n; j++) {
5766           if (roworiented) value = v[i*n+j];
5767           else value = v[i+j*m];
5768           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5769           if (in[j] >= cstart && in[j] < cend) {
5770             col = in[j] - cstart;
5771             MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5772           } else if (in[j] < 0) continue;
5773 #if defined(PETSC_USE_DEBUG)
5774           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);
5775 #endif
5776           else {
5777             if (mat->was_assembled) {
5778               if (!aij->colmap) {
5779                 ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5780               }
5781 #if defined(PETSC_USE_CTABLE)
5782               ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5783               col--;
5784 #else
5785               col = aij->colmap[in[j]] - 1;
5786 #endif
5787               if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5788                 ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5789                 col  =  in[j];
5790                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5791                 B     = aij->B;
5792                 b     = (Mat_SeqAIJ*)B->data;
5793                 bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5794                 rp2   = bj + bi[row];
5795                 ap2   = ba + bi[row];
5796                 rmax2 = bimax[row];
5797                 nrow2 = bilen[row];
5798                 low2  = 0;
5799                 high2 = nrow2;
5800                 bm    = aij->B->rmap->n;
5801                 ba    = b->a;
5802               }
5803             } else col = in[j];
5804             MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
5805           }
5806         }
5807       } else if (!aij->donotstash) {
5808         if (roworiented) {
5809           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5810         } else {
5811           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5812         }
5813       }
5814     }
5815   }
5816   PetscFunctionReturnVoid();
5817 }
5818 
5819