xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 3d96e9964ff330fd2a9eee374bcd4376da7efe60)
1 
2 
3 #include <../src/mat/impls/aij/mpi/mpiaij.h>   /*I "petscmat.h" I*/
4 #include <petsc/private/vecimpl.h>
5 #include <petsc/private/isimpl.h>
6 #include <petscblaslapack.h>
7 #include <petscsf.h>
8 
9 /*MC
10    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
11 
12    This matrix type is identical to MATSEQAIJ when constructed with a single process communicator,
13    and MATMPIAIJ otherwise.  As a result, for single process communicators,
14   MatSeqAIJSetPreallocation is supported, and similarly MatMPIAIJSetPreallocation is supported
15   for communicators controlling multiple processes.  It is recommended that you call both of
16   the above preallocation routines for simplicity.
17 
18    Options Database Keys:
19 . -mat_type aij - sets the matrix type to "aij" during a call to MatSetFromOptions()
20 
21   Developer Notes: Subclasses include MATAIJCUSP, MATAIJCUSPARSE, MATAIJPERM, MATAIJCRL, and also automatically switches over to use inodes when
22    enough exist.
23 
24   Level: beginner
25 
26 .seealso: MatCreateAIJ(), MatCreateSeqAIJ(), MATSEQAIJ, MATMPIAIJ
27 M*/
28 
29 /*MC
30    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
31 
32    This matrix type is identical to MATSEQAIJCRL when constructed with a single process communicator,
33    and MATMPIAIJCRL otherwise.  As a result, for single process communicators,
34    MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
35   for communicators controlling multiple processes.  It is recommended that you call both of
36   the above preallocation routines for simplicity.
37 
38    Options Database Keys:
39 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to MatSetFromOptions()
40 
41   Level: beginner
42 
43 .seealso: MatCreateMPIAIJCRL,MATSEQAIJCRL,MATMPIAIJCRL, MATSEQAIJCRL, MATMPIAIJCRL
44 M*/
45 
46 PetscErrorCode MatSetBlockSizes_MPIAIJ(Mat M, PetscInt rbs, PetscInt cbs)
47 {
48   PetscErrorCode ierr;
49   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)M->data;
50 
51   PetscFunctionBegin;
52   if (mat->A) {
53     ierr = MatSetBlockSizes(mat->A,rbs,cbs);CHKERRQ(ierr);
54     ierr = MatSetBlockSizes(mat->B,rbs,1);CHKERRQ(ierr);
55   }
56   PetscFunctionReturn(0);
57 }
58 
59 PetscErrorCode MatFindNonzeroRows_MPIAIJ(Mat M,IS *keptrows)
60 {
61   PetscErrorCode  ierr;
62   Mat_MPIAIJ      *mat = (Mat_MPIAIJ*)M->data;
63   Mat_SeqAIJ      *a   = (Mat_SeqAIJ*)mat->A->data;
64   Mat_SeqAIJ      *b   = (Mat_SeqAIJ*)mat->B->data;
65   const PetscInt  *ia,*ib;
66   const MatScalar *aa,*bb;
67   PetscInt        na,nb,i,j,*rows,cnt=0,n0rows;
68   PetscInt        m = M->rmap->n,rstart = M->rmap->rstart;
69 
70   PetscFunctionBegin;
71   *keptrows = 0;
72   ia        = a->i;
73   ib        = b->i;
74   for (i=0; i<m; i++) {
75     na = ia[i+1] - ia[i];
76     nb = ib[i+1] - ib[i];
77     if (!na && !nb) {
78       cnt++;
79       goto ok1;
80     }
81     aa = a->a + ia[i];
82     for (j=0; j<na; j++) {
83       if (aa[j] != 0.0) goto ok1;
84     }
85     bb = b->a + ib[i];
86     for (j=0; j <nb; j++) {
87       if (bb[j] != 0.0) goto ok1;
88     }
89     cnt++;
90 ok1:;
91   }
92   ierr = MPIU_Allreduce(&cnt,&n0rows,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)M));CHKERRQ(ierr);
93   if (!n0rows) PetscFunctionReturn(0);
94   ierr = PetscMalloc1(M->rmap->n-cnt,&rows);CHKERRQ(ierr);
95   cnt  = 0;
96   for (i=0; i<m; i++) {
97     na = ia[i+1] - ia[i];
98     nb = ib[i+1] - ib[i];
99     if (!na && !nb) continue;
100     aa = a->a + ia[i];
101     for (j=0; j<na;j++) {
102       if (aa[j] != 0.0) {
103         rows[cnt++] = rstart + i;
104         goto ok2;
105       }
106     }
107     bb = b->a + ib[i];
108     for (j=0; j<nb; j++) {
109       if (bb[j] != 0.0) {
110         rows[cnt++] = rstart + i;
111         goto ok2;
112       }
113     }
114 ok2:;
115   }
116   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),cnt,rows,PETSC_OWN_POINTER,keptrows);CHKERRQ(ierr);
117   PetscFunctionReturn(0);
118 }
119 
120 PetscErrorCode  MatDiagonalSet_MPIAIJ(Mat Y,Vec D,InsertMode is)
121 {
122   PetscErrorCode    ierr;
123   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*) Y->data;
124 
125   PetscFunctionBegin;
126   if (Y->assembled && Y->rmap->rstart == Y->cmap->rstart && Y->rmap->rend == Y->cmap->rend) {
127     ierr = MatDiagonalSet(aij->A,D,is);CHKERRQ(ierr);
128   } else {
129     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
130   }
131   PetscFunctionReturn(0);
132 }
133 
134 PetscErrorCode MatFindZeroDiagonals_MPIAIJ(Mat M,IS *zrows)
135 {
136   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)M->data;
137   PetscErrorCode ierr;
138   PetscInt       i,rstart,nrows,*rows;
139 
140   PetscFunctionBegin;
141   *zrows = NULL;
142   ierr   = MatFindZeroDiagonals_SeqAIJ_Private(aij->A,&nrows,&rows);CHKERRQ(ierr);
143   ierr   = MatGetOwnershipRange(M,&rstart,NULL);CHKERRQ(ierr);
144   for (i=0; i<nrows; i++) rows[i] += rstart;
145   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),nrows,rows,PETSC_OWN_POINTER,zrows);CHKERRQ(ierr);
146   PetscFunctionReturn(0);
147 }
148 
149 PetscErrorCode MatGetColumnNorms_MPIAIJ(Mat A,NormType type,PetscReal *norms)
150 {
151   PetscErrorCode ierr;
152   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)A->data;
153   PetscInt       i,n,*garray = aij->garray;
154   Mat_SeqAIJ     *a_aij = (Mat_SeqAIJ*) aij->A->data;
155   Mat_SeqAIJ     *b_aij = (Mat_SeqAIJ*) aij->B->data;
156   PetscReal      *work;
157 
158   PetscFunctionBegin;
159   ierr = MatGetSize(A,NULL,&n);CHKERRQ(ierr);
160   ierr = PetscCalloc1(n,&work);CHKERRQ(ierr);
161   if (type == NORM_2) {
162     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
163       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]*a_aij->a[i]);
164     }
165     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
166       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]*b_aij->a[i]);
167     }
168   } else if (type == NORM_1) {
169     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
170       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
171     }
172     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
173       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
174     }
175   } else if (type == NORM_INFINITY) {
176     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
177       work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
178     }
179     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
180       work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]),work[garray[b_aij->j[i]]]);
181     }
182 
183   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONG,"Unknown NormType");
184   if (type == NORM_INFINITY) {
185     ierr = MPIU_Allreduce(work,norms,n,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
186   } else {
187     ierr = MPIU_Allreduce(work,norms,n,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
188   }
189   ierr = PetscFree(work);CHKERRQ(ierr);
190   if (type == NORM_2) {
191     for (i=0; i<n; i++) norms[i] = PetscSqrtReal(norms[i]);
192   }
193   PetscFunctionReturn(0);
194 }
195 
196 PetscErrorCode MatFindOffBlockDiagonalEntries_MPIAIJ(Mat A,IS *is)
197 {
198   Mat_MPIAIJ      *a  = (Mat_MPIAIJ*)A->data;
199   IS              sis,gis;
200   PetscErrorCode  ierr;
201   const PetscInt  *isis,*igis;
202   PetscInt        n,*iis,nsis,ngis,rstart,i;
203 
204   PetscFunctionBegin;
205   ierr = MatFindOffBlockDiagonalEntries(a->A,&sis);CHKERRQ(ierr);
206   ierr = MatFindNonzeroRows(a->B,&gis);CHKERRQ(ierr);
207   ierr = ISGetSize(gis,&ngis);CHKERRQ(ierr);
208   ierr = ISGetSize(sis,&nsis);CHKERRQ(ierr);
209   ierr = ISGetIndices(sis,&isis);CHKERRQ(ierr);
210   ierr = ISGetIndices(gis,&igis);CHKERRQ(ierr);
211 
212   ierr = PetscMalloc1(ngis+nsis,&iis);CHKERRQ(ierr);
213   ierr = PetscMemcpy(iis,igis,ngis*sizeof(PetscInt));CHKERRQ(ierr);
214   ierr = PetscMemcpy(iis+ngis,isis,nsis*sizeof(PetscInt));CHKERRQ(ierr);
215   n    = ngis + nsis;
216   ierr = PetscSortRemoveDupsInt(&n,iis);CHKERRQ(ierr);
217   ierr = MatGetOwnershipRange(A,&rstart,NULL);CHKERRQ(ierr);
218   for (i=0; i<n; i++) iis[i] += rstart;
219   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)A),n,iis,PETSC_OWN_POINTER,is);CHKERRQ(ierr);
220 
221   ierr = ISRestoreIndices(sis,&isis);CHKERRQ(ierr);
222   ierr = ISRestoreIndices(gis,&igis);CHKERRQ(ierr);
223   ierr = ISDestroy(&sis);CHKERRQ(ierr);
224   ierr = ISDestroy(&gis);CHKERRQ(ierr);
225   PetscFunctionReturn(0);
226 }
227 
228 /*
229     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
230     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
231 
232     Only for square matrices
233 
234     Used by a preconditioner, hence PETSC_EXTERN
235 */
236 PETSC_EXTERN PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
237 {
238   PetscMPIInt    rank,size;
239   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz = 0,*gmataj,cnt,row,*ld,bses[2];
240   PetscErrorCode ierr;
241   Mat            mat;
242   Mat_SeqAIJ     *gmata;
243   PetscMPIInt    tag;
244   MPI_Status     status;
245   PetscBool      aij;
246   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
247 
248   PetscFunctionBegin;
249   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
250   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
251   if (!rank) {
252     ierr = PetscObjectTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
253     if (!aij) SETERRQ1(PetscObjectComm((PetscObject)gmat),PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
254   }
255   if (reuse == MAT_INITIAL_MATRIX) {
256     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
257     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
258     ierr = MatGetBlockSizes(gmat,&bses[0],&bses[1]);CHKERRQ(ierr);
259     ierr = MPI_Bcast(bses,2,MPIU_INT,0,comm);CHKERRQ(ierr);
260     ierr = MatSetBlockSizes(mat,bses[0],bses[1]);CHKERRQ(ierr);
261     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
262     ierr = PetscMalloc1(size+1,&rowners);CHKERRQ(ierr);
263     ierr = PetscMalloc2(m,&dlens,m,&olens);CHKERRQ(ierr);
264     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
265 
266     rowners[0] = 0;
267     for (i=2; i<=size; i++) rowners[i] += rowners[i-1];
268     rstart = rowners[rank];
269     rend   = rowners[rank+1];
270     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
271     if (!rank) {
272       gmata = (Mat_SeqAIJ*) gmat->data;
273       /* send row lengths to all processors */
274       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
275       for (i=1; i<size; i++) {
276         ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
277       }
278       /* determine number diagonal and off-diagonal counts */
279       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
280       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
281       jj   = 0;
282       for (i=0; i<m; i++) {
283         for (j=0; j<dlens[i]; j++) {
284           if (gmata->j[jj] < rstart) ld[i]++;
285           if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
286           jj++;
287         }
288       }
289       /* send column indices to other processes */
290       for (i=1; i<size; i++) {
291         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
292         ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
293         ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
294       }
295 
296       /* send numerical values to other processes */
297       for (i=1; i<size; i++) {
298         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
299         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
300       }
301       gmataa = gmata->a;
302       gmataj = gmata->j;
303 
304     } else {
305       /* receive row lengths */
306       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
307       /* receive column indices */
308       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
309       ierr = PetscMalloc2(nz,&gmataa,nz,&gmataj);CHKERRQ(ierr);
310       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
311       /* determine number diagonal and off-diagonal counts */
312       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
313       ierr = PetscCalloc1(m,&ld);CHKERRQ(ierr);
314       jj   = 0;
315       for (i=0; i<m; i++) {
316         for (j=0; j<dlens[i]; j++) {
317           if (gmataj[jj] < rstart) ld[i]++;
318           if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
319           jj++;
320         }
321       }
322       /* receive numerical values */
323       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
324       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
325     }
326     /* set preallocation */
327     for (i=0; i<m; i++) {
328       dlens[i] -= olens[i];
329     }
330     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
331     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
332 
333     for (i=0; i<m; i++) {
334       dlens[i] += olens[i];
335     }
336     cnt = 0;
337     for (i=0; i<m; i++) {
338       row  = rstart + i;
339       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
340       cnt += dlens[i];
341     }
342     if (rank) {
343       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
344     }
345     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
346     ierr = PetscFree(rowners);CHKERRQ(ierr);
347 
348     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
349 
350     *inmat = mat;
351   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
352     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
353     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
354     mat  = *inmat;
355     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
356     if (!rank) {
357       /* send numerical values to other processes */
358       gmata  = (Mat_SeqAIJ*) gmat->data;
359       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
360       gmataa = gmata->a;
361       for (i=1; i<size; i++) {
362         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
363         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
364       }
365       nz = gmata->i[rowners[1]]-gmata->i[rowners[0]];
366     } else {
367       /* receive numerical values from process 0*/
368       nz   = Ad->nz + Ao->nz;
369       ierr = PetscMalloc1(nz,&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
370       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
371     }
372     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
373     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
374     ad = Ad->a;
375     ao = Ao->a;
376     if (mat->rmap->n) {
377       i  = 0;
378       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
379       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
380     }
381     for (i=1; i<mat->rmap->n; i++) {
382       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;
383       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
384     }
385     i--;
386     if (mat->rmap->n) {
387       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
388     }
389     if (rank) {
390       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
391     }
392   }
393   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
394   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
395   PetscFunctionReturn(0);
396 }
397 
398 /*
399   Local utility routine that creates a mapping from the global column
400 number to the local number in the off-diagonal part of the local
401 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
402 a slightly higher hash table cost; without it it is not scalable (each processor
403 has an order N integer array but is fast to acess.
404 */
405 PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
406 {
407   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
408   PetscErrorCode ierr;
409   PetscInt       n = aij->B->cmap->n,i;
410 
411   PetscFunctionBegin;
412   if (!aij->garray) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPIAIJ Matrix was assembled but is missing garray");
413 #if defined(PETSC_USE_CTABLE)
414   ierr = PetscTableCreate(n,mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
415   for (i=0; i<n; i++) {
416     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1,INSERT_VALUES);CHKERRQ(ierr);
417   }
418 #else
419   ierr = PetscCalloc1(mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
420   ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N+1)*sizeof(PetscInt));CHKERRQ(ierr);
421   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
422 #endif
423   PetscFunctionReturn(0);
424 }
425 
426 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv,orow,ocol)     \
427 { \
428     if (col <= lastcol1)  low1 = 0;     \
429     else                 high1 = nrow1; \
430     lastcol1 = col;\
431     while (high1-low1 > 5) { \
432       t = (low1+high1)/2; \
433       if (rp1[t] > col) high1 = t; \
434       else              low1  = t; \
435     } \
436       for (_i=low1; _i<high1; _i++) { \
437         if (rp1[_i] > col) break; \
438         if (rp1[_i] == col) { \
439           if (addv == ADD_VALUES) ap1[_i] += value;   \
440           else                    ap1[_i] = value; \
441           goto a_noinsert; \
442         } \
443       }  \
444       if (value == 0.0 && ignorezeroentries && row != col) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
445       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}                \
446       if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero at global row/column (%D, %D) into matrix", orow, ocol); \
447       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
448       N = nrow1++ - 1; a->nz++; high1++; \
449       /* shift up all the later entries in this row */ \
450       for (ii=N; ii>=_i; ii--) { \
451         rp1[ii+1] = rp1[ii]; \
452         ap1[ii+1] = ap1[ii]; \
453       } \
454       rp1[_i] = col;  \
455       ap1[_i] = value;  \
456       A->nonzerostate++;\
457       a_noinsert: ; \
458       ailen[row] = nrow1; \
459 }
460 
461 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv,orow,ocol) \
462   { \
463     if (col <= lastcol2) low2 = 0;                        \
464     else high2 = nrow2;                                   \
465     lastcol2 = col;                                       \
466     while (high2-low2 > 5) {                              \
467       t = (low2+high2)/2;                                 \
468       if (rp2[t] > col) high2 = t;                        \
469       else             low2  = t;                         \
470     }                                                     \
471     for (_i=low2; _i<high2; _i++) {                       \
472       if (rp2[_i] > col) break;                           \
473       if (rp2[_i] == col) {                               \
474         if (addv == ADD_VALUES) ap2[_i] += value;         \
475         else                    ap2[_i] = value;          \
476         goto b_noinsert;                                  \
477       }                                                   \
478     }                                                     \
479     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
480     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}                        \
481     if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero at global row/column (%D, %D) into matrix", orow, ocol); \
482     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
483     N = nrow2++ - 1; b->nz++; high2++;                    \
484     /* shift up all the later entries in this row */      \
485     for (ii=N; ii>=_i; ii--) {                            \
486       rp2[ii+1] = rp2[ii];                                \
487       ap2[ii+1] = ap2[ii];                                \
488     }                                                     \
489     rp2[_i] = col;                                        \
490     ap2[_i] = value;                                      \
491     B->nonzerostate++;                                    \
492     b_noinsert: ;                                         \
493     bilen[row] = nrow2;                                   \
494   }
495 
496 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
497 {
498   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
499   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
500   PetscErrorCode ierr;
501   PetscInt       l,*garray = mat->garray,diag;
502 
503   PetscFunctionBegin;
504   /* code only works for square matrices A */
505 
506   /* find size of row to the left of the diagonal part */
507   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
508   row  = row - diag;
509   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
510     if (garray[b->j[b->i[row]+l]] > diag) break;
511   }
512   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
513 
514   /* diagonal part */
515   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
516 
517   /* right of diagonal part */
518   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);
519   PetscFunctionReturn(0);
520 }
521 
522 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
523 {
524   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
525   PetscScalar    value;
526   PetscErrorCode ierr;
527   PetscInt       i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
528   PetscInt       cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
529   PetscBool      roworiented = aij->roworiented;
530 
531   /* Some Variables required in the macro */
532   Mat        A                 = aij->A;
533   Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
534   PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
535   MatScalar  *aa               = a->a;
536   PetscBool  ignorezeroentries = a->ignorezeroentries;
537   Mat        B                 = aij->B;
538   Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
539   PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
540   MatScalar  *ba               = b->a;
541 
542   PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
543   PetscInt  nonew;
544   MatScalar *ap1,*ap2;
545 
546   PetscFunctionBegin;
547   for (i=0; i<m; i++) {
548     if (im[i] < 0) continue;
549 #if defined(PETSC_USE_DEBUG)
550     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);
551 #endif
552     if (im[i] >= rstart && im[i] < rend) {
553       row      = im[i] - rstart;
554       lastcol1 = -1;
555       rp1      = aj + ai[row];
556       ap1      = aa + ai[row];
557       rmax1    = aimax[row];
558       nrow1    = ailen[row];
559       low1     = 0;
560       high1    = nrow1;
561       lastcol2 = -1;
562       rp2      = bj + bi[row];
563       ap2      = ba + bi[row];
564       rmax2    = bimax[row];
565       nrow2    = bilen[row];
566       low2     = 0;
567       high2    = nrow2;
568 
569       for (j=0; j<n; j++) {
570         if (roworiented) value = v[i*n+j];
571         else             value = v[i+j*m];
572         if (in[j] >= cstart && in[j] < cend) {
573           col   = in[j] - cstart;
574           nonew = a->nonew;
575           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES) && row != col) continue;
576           MatSetValues_SeqAIJ_A_Private(row,col,value,addv,im[i],in[j]);
577         } else if (in[j] < 0) continue;
578 #if defined(PETSC_USE_DEBUG)
579         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);
580 #endif
581         else {
582           if (mat->was_assembled) {
583             if (!aij->colmap) {
584               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
585             }
586 #if defined(PETSC_USE_CTABLE)
587             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
588             col--;
589 #else
590             col = aij->colmap[in[j]] - 1;
591 #endif
592             if (col < 0 && !((Mat_SeqAIJ*)(aij->B->data))->nonew) {
593               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
594               col  =  in[j];
595               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
596               B     = aij->B;
597               b     = (Mat_SeqAIJ*)B->data;
598               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
599               rp2   = bj + bi[row];
600               ap2   = ba + bi[row];
601               rmax2 = bimax[row];
602               nrow2 = bilen[row];
603               low2  = 0;
604               high2 = nrow2;
605               bm    = aij->B->rmap->n;
606               ba    = b->a;
607             } else if (col < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero at global row/column (%D, %D) into matrix", im[i], in[j]);
608           } else col = in[j];
609           nonew = b->nonew;
610           MatSetValues_SeqAIJ_B_Private(row,col,value,addv,im[i],in[j]);
611         }
612       }
613     } else {
614       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]);
615       if (!aij->donotstash) {
616         mat->assembled = PETSC_FALSE;
617         if (roworiented) {
618           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
619         } else {
620           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
621         }
622       }
623     }
624   }
625   PetscFunctionReturn(0);
626 }
627 
628 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
629 {
630   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
631   PetscErrorCode ierr;
632   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
633   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
634 
635   PetscFunctionBegin;
636   for (i=0; i<m; i++) {
637     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
638     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);
639     if (idxm[i] >= rstart && idxm[i] < rend) {
640       row = idxm[i] - rstart;
641       for (j=0; j<n; j++) {
642         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
643         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);
644         if (idxn[j] >= cstart && idxn[j] < cend) {
645           col  = idxn[j] - cstart;
646           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
647         } else {
648           if (!aij->colmap) {
649             ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
650           }
651 #if defined(PETSC_USE_CTABLE)
652           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
653           col--;
654 #else
655           col = aij->colmap[idxn[j]] - 1;
656 #endif
657           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
658           else {
659             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
660           }
661         }
662       }
663     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only local values currently supported");
664   }
665   PetscFunctionReturn(0);
666 }
667 
668 extern PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat,Vec,Vec);
669 
670 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
671 {
672   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
673   PetscErrorCode ierr;
674   PetscInt       nstash,reallocs;
675 
676   PetscFunctionBegin;
677   if (aij->donotstash || mat->nooffprocentries) PetscFunctionReturn(0);
678 
679   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
680   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
681   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
682   PetscFunctionReturn(0);
683 }
684 
685 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
686 {
687   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
688   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)aij->A->data;
689   PetscErrorCode ierr;
690   PetscMPIInt    n;
691   PetscInt       i,j,rstart,ncols,flg;
692   PetscInt       *row,*col;
693   PetscBool      other_disassembled;
694   PetscScalar    *val;
695 
696   /* do not use 'b = (Mat_SeqAIJ*)aij->B->data' as B can be reset in disassembly */
697 
698   PetscFunctionBegin;
699   if (!aij->donotstash && !mat->nooffprocentries) {
700     while (1) {
701       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
702       if (!flg) break;
703 
704       for (i=0; i<n; ) {
705         /* Now identify the consecutive vals belonging to the same row */
706         for (j=i,rstart=row[j]; j<n; j++) {
707           if (row[j] != rstart) break;
708         }
709         if (j < n) ncols = j-i;
710         else       ncols = n-i;
711         /* Now assemble all these values with a single function call */
712         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,mat->insertmode);CHKERRQ(ierr);
713 
714         i = j;
715       }
716     }
717     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
718   }
719   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
720   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
721 
722   /* determine if any processor has disassembled, if so we must
723      also disassemble ourselfs, in order that we may reassemble. */
724   /*
725      if nonzero structure of submatrix B cannot change then we know that
726      no processor disassembled thus we can skip this stuff
727   */
728   if (!((Mat_SeqAIJ*)aij->B->data)->nonew) {
729     ierr = MPIU_Allreduce(&mat->was_assembled,&other_disassembled,1,MPIU_BOOL,MPI_PROD,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
730     if (mat->was_assembled && !other_disassembled) {
731       ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
732     }
733   }
734   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
735     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
736   }
737   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
738   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
739   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
740 
741   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
742 
743   aij->rowvalues = 0;
744 
745   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
746   if (a->inode.size) mat->ops->multdiagonalblock = MatMultDiagonalBlock_MPIAIJ;
747 
748   /* if no new nonzero locations are allowed in matrix then only set the matrix state the first time through */
749   if ((!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) || !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
750     PetscObjectState state = aij->A->nonzerostate + aij->B->nonzerostate;
751     ierr = MPIU_Allreduce(&state,&mat->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
752   }
753   PetscFunctionReturn(0);
754 }
755 
756 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
757 {
758   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
759   PetscErrorCode ierr;
760 
761   PetscFunctionBegin;
762   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
763   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
764   PetscFunctionReturn(0);
765 }
766 
767 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
768 {
769   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
770   PetscInt      *lrows;
771   PetscInt       r, len;
772   PetscErrorCode ierr;
773 
774   PetscFunctionBegin;
775   /* get locally owned rows */
776   ierr = MatZeroRowsMapLocal_Private(A,N,rows,&len,&lrows);CHKERRQ(ierr);
777   /* fix right hand side if needed */
778   if (x && b) {
779     const PetscScalar *xx;
780     PetscScalar       *bb;
781 
782     ierr = VecGetArrayRead(x, &xx);CHKERRQ(ierr);
783     ierr = VecGetArray(b, &bb);CHKERRQ(ierr);
784     for (r = 0; r < len; ++r) bb[lrows[r]] = diag*xx[lrows[r]];
785     ierr = VecRestoreArrayRead(x, &xx);CHKERRQ(ierr);
786     ierr = VecRestoreArray(b, &bb);CHKERRQ(ierr);
787   }
788   /* Must zero l->B before l->A because the (diag) case below may put values into l->B*/
789   ierr = MatZeroRows(mat->B, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
790   if (A->congruentlayouts == -1) { /* first time we compare rows and cols layouts */
791     PetscBool cong;
792     ierr = PetscLayoutCompare(A->rmap,A->cmap,&cong);CHKERRQ(ierr);
793     if (cong) A->congruentlayouts = 1;
794     else      A->congruentlayouts = 0;
795   }
796   if ((diag != 0.0) && A->congruentlayouts) {
797     ierr = MatZeroRows(mat->A, len, lrows, diag, NULL, NULL);CHKERRQ(ierr);
798   } else if (diag != 0.0) {
799     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
800     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");
801     for (r = 0; r < len; ++r) {
802       const PetscInt row = lrows[r] + A->rmap->rstart;
803       ierr = MatSetValues(A, 1, &row, 1, &row, &diag, INSERT_VALUES);CHKERRQ(ierr);
804     }
805     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
806     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
807   } else {
808     ierr = MatZeroRows(mat->A, len, lrows, 0.0, NULL, NULL);CHKERRQ(ierr);
809   }
810   ierr = PetscFree(lrows);CHKERRQ(ierr);
811 
812   /* only change matrix nonzero state if pattern was allowed to be changed */
813   if (!((Mat_SeqAIJ*)(mat->A->data))->keepnonzeropattern) {
814     PetscObjectState state = mat->A->nonzerostate + mat->B->nonzerostate;
815     ierr = MPIU_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
816   }
817   PetscFunctionReturn(0);
818 }
819 
820 PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
821 {
822   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
823   PetscErrorCode    ierr;
824   PetscMPIInt       n = A->rmap->n;
825   PetscInt          i,j,r,m,p = 0,len = 0;
826   PetscInt          *lrows,*owners = A->rmap->range;
827   PetscSFNode       *rrows;
828   PetscSF           sf;
829   const PetscScalar *xx;
830   PetscScalar       *bb,*mask;
831   Vec               xmask,lmask;
832   Mat_SeqAIJ        *aij = (Mat_SeqAIJ*)l->B->data;
833   const PetscInt    *aj, *ii,*ridx;
834   PetscScalar       *aa;
835 
836   PetscFunctionBegin;
837   /* Create SF where leaves are input rows and roots are owned rows */
838   ierr = PetscMalloc1(n, &lrows);CHKERRQ(ierr);
839   for (r = 0; r < n; ++r) lrows[r] = -1;
840   ierr = PetscMalloc1(N, &rrows);CHKERRQ(ierr);
841   for (r = 0; r < N; ++r) {
842     const PetscInt idx   = rows[r];
843     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);
844     if (idx < owners[p] || owners[p+1] <= idx) { /* short-circuit the search if the last p owns this row too */
845       ierr = PetscLayoutFindOwner(A->rmap,idx,&p);CHKERRQ(ierr);
846     }
847     rrows[r].rank  = p;
848     rrows[r].index = rows[r] - owners[p];
849   }
850   ierr = PetscSFCreate(PetscObjectComm((PetscObject) A), &sf);CHKERRQ(ierr);
851   ierr = PetscSFSetGraph(sf, n, N, NULL, PETSC_OWN_POINTER, rrows, PETSC_OWN_POINTER);CHKERRQ(ierr);
852   /* Collect flags for rows to be zeroed */
853   ierr = PetscSFReduceBegin(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
854   ierr = PetscSFReduceEnd(sf, MPIU_INT, (PetscInt *) rows, lrows, MPI_LOR);CHKERRQ(ierr);
855   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
856   /* Compress and put in row numbers */
857   for (r = 0; r < n; ++r) if (lrows[r] >= 0) lrows[len++] = r;
858   /* zero diagonal part of matrix */
859   ierr = MatZeroRowsColumns(l->A,len,lrows,diag,x,b);CHKERRQ(ierr);
860   /* handle off diagonal part of matrix */
861   ierr = MatCreateVecs(A,&xmask,NULL);CHKERRQ(ierr);
862   ierr = VecDuplicate(l->lvec,&lmask);CHKERRQ(ierr);
863   ierr = VecGetArray(xmask,&bb);CHKERRQ(ierr);
864   for (i=0; i<len; i++) bb[lrows[i]] = 1;
865   ierr = VecRestoreArray(xmask,&bb);CHKERRQ(ierr);
866   ierr = VecScatterBegin(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
867   ierr = VecScatterEnd(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
868   ierr = VecDestroy(&xmask);CHKERRQ(ierr);
869   if (x) {
870     ierr = VecScatterBegin(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
871     ierr = VecScatterEnd(l->Mvctx,x,l->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
872     ierr = VecGetArrayRead(l->lvec,&xx);CHKERRQ(ierr);
873     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
874   }
875   ierr = VecGetArray(lmask,&mask);CHKERRQ(ierr);
876   /* remove zeroed rows of off diagonal matrix */
877   ii = aij->i;
878   for (i=0; i<len; i++) {
879     ierr = PetscMemzero(aij->a + ii[lrows[i]],(ii[lrows[i]+1] - ii[lrows[i]])*sizeof(PetscScalar));CHKERRQ(ierr);
880   }
881   /* loop over all elements of off process part of matrix zeroing removed columns*/
882   if (aij->compressedrow.use) {
883     m    = aij->compressedrow.nrows;
884     ii   = aij->compressedrow.i;
885     ridx = aij->compressedrow.rindex;
886     for (i=0; i<m; i++) {
887       n  = ii[i+1] - ii[i];
888       aj = aij->j + ii[i];
889       aa = aij->a + ii[i];
890 
891       for (j=0; j<n; j++) {
892         if (PetscAbsScalar(mask[*aj])) {
893           if (b) bb[*ridx] -= *aa*xx[*aj];
894           *aa = 0.0;
895         }
896         aa++;
897         aj++;
898       }
899       ridx++;
900     }
901   } else { /* do not use compressed row format */
902     m = l->B->rmap->n;
903     for (i=0; i<m; i++) {
904       n  = ii[i+1] - ii[i];
905       aj = aij->j + ii[i];
906       aa = aij->a + ii[i];
907       for (j=0; j<n; j++) {
908         if (PetscAbsScalar(mask[*aj])) {
909           if (b) bb[i] -= *aa*xx[*aj];
910           *aa = 0.0;
911         }
912         aa++;
913         aj++;
914       }
915     }
916   }
917   if (x) {
918     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
919     ierr = VecRestoreArrayRead(l->lvec,&xx);CHKERRQ(ierr);
920   }
921   ierr = VecRestoreArray(lmask,&mask);CHKERRQ(ierr);
922   ierr = VecDestroy(&lmask);CHKERRQ(ierr);
923   ierr = PetscFree(lrows);CHKERRQ(ierr);
924 
925   /* only change matrix nonzero state if pattern was allowed to be changed */
926   if (!((Mat_SeqAIJ*)(l->A->data))->keepnonzeropattern) {
927     PetscObjectState state = l->A->nonzerostate + l->B->nonzerostate;
928     ierr = MPIU_Allreduce(&state,&A->nonzerostate,1,MPIU_INT64,MPI_SUM,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
929   }
930   PetscFunctionReturn(0);
931 }
932 
933 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
934 {
935   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
936   PetscErrorCode ierr;
937   PetscInt       nt;
938 
939   PetscFunctionBegin;
940   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
941   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);
942   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
943   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
944   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
945   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
946   PetscFunctionReturn(0);
947 }
948 
949 PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A,Vec bb,Vec xx)
950 {
951   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
952   PetscErrorCode ierr;
953 
954   PetscFunctionBegin;
955   ierr = MatMultDiagonalBlock(a->A,bb,xx);CHKERRQ(ierr);
956   PetscFunctionReturn(0);
957 }
958 
959 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
960 {
961   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
962   PetscErrorCode ierr;
963 
964   PetscFunctionBegin;
965   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
966   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
967   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
968   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
969   PetscFunctionReturn(0);
970 }
971 
972 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
973 {
974   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
975   PetscErrorCode ierr;
976   PetscBool      merged;
977 
978   PetscFunctionBegin;
979   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
980   /* do nondiagonal part */
981   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
982   if (!merged) {
983     /* send it on its way */
984     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
985     /* do local part */
986     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
987     /* receive remote parts: note this assumes the values are not actually */
988     /* added in yy until the next line, */
989     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
990   } else {
991     /* do local part */
992     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
993     /* send it on its way */
994     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
995     /* values actually were received in the Begin() but we need to call this nop */
996     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
997   }
998   PetscFunctionReturn(0);
999 }
1000 
1001 PetscErrorCode MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscBool  *f)
1002 {
1003   MPI_Comm       comm;
1004   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ*) Amat->data, *Bij;
1005   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
1006   IS             Me,Notme;
1007   PetscErrorCode ierr;
1008   PetscInt       M,N,first,last,*notme,i;
1009   PetscMPIInt    size;
1010 
1011   PetscFunctionBegin;
1012   /* Easy test: symmetric diagonal block */
1013   Bij  = (Mat_MPIAIJ*) Bmat->data; Bdia = Bij->A;
1014   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
1015   if (!*f) PetscFunctionReturn(0);
1016   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1017   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1018   if (size == 1) PetscFunctionReturn(0);
1019 
1020   /* Hard test: off-diagonal block. This takes a MatCreateSubMatrix. */
1021   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
1022   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
1023   ierr = PetscMalloc1(N-last+first,&notme);CHKERRQ(ierr);
1024   for (i=0; i<first; i++) notme[i] = i;
1025   for (i=last; i<M; i++) notme[i-last+first] = i;
1026   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,PETSC_COPY_VALUES,&Notme);CHKERRQ(ierr);
1027   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
1028   ierr = MatCreateSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
1029   Aoff = Aoffs[0];
1030   ierr = MatCreateSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
1031   Boff = Boffs[0];
1032   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
1033   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
1034   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
1035   ierr = ISDestroy(&Me);CHKERRQ(ierr);
1036   ierr = ISDestroy(&Notme);CHKERRQ(ierr);
1037   ierr = PetscFree(notme);CHKERRQ(ierr);
1038   PetscFunctionReturn(0);
1039 }
1040 
1041 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1042 {
1043   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1044   PetscErrorCode ierr;
1045 
1046   PetscFunctionBegin;
1047   /* do nondiagonal part */
1048   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1049   /* send it on its way */
1050   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1051   /* do local part */
1052   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1053   /* receive remote parts */
1054   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1055   PetscFunctionReturn(0);
1056 }
1057 
1058 /*
1059   This only works correctly for square matrices where the subblock A->A is the
1060    diagonal block
1061 */
1062 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
1063 {
1064   PetscErrorCode ierr;
1065   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1066 
1067   PetscFunctionBegin;
1068   if (A->rmap->N != A->cmap->N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
1069   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");
1070   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1071   PetscFunctionReturn(0);
1072 }
1073 
1074 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
1075 {
1076   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1077   PetscErrorCode ierr;
1078 
1079   PetscFunctionBegin;
1080   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
1081   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
1082   PetscFunctionReturn(0);
1083 }
1084 
1085 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
1086 {
1087   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1088   PetscErrorCode ierr;
1089 
1090   PetscFunctionBegin;
1091 #if defined(PETSC_USE_LOG)
1092   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
1093 #endif
1094   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
1095   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
1096   ierr = MatDestroy(&aij->A);CHKERRQ(ierr);
1097   ierr = MatDestroy(&aij->B);CHKERRQ(ierr);
1098 #if defined(PETSC_USE_CTABLE)
1099   ierr = PetscTableDestroy(&aij->colmap);CHKERRQ(ierr);
1100 #else
1101   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
1102 #endif
1103   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
1104   ierr = VecDestroy(&aij->lvec);CHKERRQ(ierr);
1105   ierr = VecScatterDestroy(&aij->Mvctx);CHKERRQ(ierr);
1106   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
1107   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
1108   ierr = PetscFree(mat->data);CHKERRQ(ierr);
1109 
1110   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
1111   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C",NULL);CHKERRQ(ierr);
1112   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C",NULL);CHKERRQ(ierr);
1113   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C",NULL);CHKERRQ(ierr);
1114   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C",NULL);CHKERRQ(ierr);
1115   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C",NULL);CHKERRQ(ierr);
1116   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C",NULL);CHKERRQ(ierr);
1117   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_mpisbaij_C",NULL);CHKERRQ(ierr);
1118 #if defined(PETSC_HAVE_ELEMENTAL)
1119   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_elemental_C",NULL);CHKERRQ(ierr);
1120 #endif
1121 #if defined(PETSC_HAVE_HYPRE)
1122   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_hypre_C",NULL);CHKERRQ(ierr);
1123   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMatMatMult_transpose_mpiaij_mpiaij_C",NULL);CHKERRQ(ierr);
1124 #endif
1125   PetscFunctionReturn(0);
1126 }
1127 
1128 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
1129 {
1130   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1131   Mat_SeqAIJ     *A   = (Mat_SeqAIJ*)aij->A->data;
1132   Mat_SeqAIJ     *B   = (Mat_SeqAIJ*)aij->B->data;
1133   PetscErrorCode ierr;
1134   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
1135   int            fd;
1136   PetscInt       nz,header[4],*row_lengths,*range=0,rlen,i;
1137   PetscInt       nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz = 0;
1138   PetscScalar    *column_values;
1139   PetscInt       message_count,flowcontrolcount;
1140   FILE           *file;
1141 
1142   PetscFunctionBegin;
1143   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1144   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
1145   nz   = A->nz + B->nz;
1146   ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
1147   if (!rank) {
1148     header[0] = MAT_FILE_CLASSID;
1149     header[1] = mat->rmap->N;
1150     header[2] = mat->cmap->N;
1151 
1152     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1153     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1154     /* get largest number of rows any processor has */
1155     rlen  = mat->rmap->n;
1156     range = mat->rmap->range;
1157     for (i=1; i<size; i++) rlen = PetscMax(rlen,range[i+1] - range[i]);
1158   } else {
1159     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1160     rlen = mat->rmap->n;
1161   }
1162 
1163   /* load up the local row counts */
1164   ierr = PetscMalloc1(rlen+1,&row_lengths);CHKERRQ(ierr);
1165   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];
1166 
1167   /* store the row lengths to the file */
1168   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1169   if (!rank) {
1170     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1171     for (i=1; i<size; i++) {
1172       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1173       rlen = range[i+1] - range[i];
1174       ierr = MPIULong_Recv(row_lengths,rlen,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1175       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1176     }
1177     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1178   } else {
1179     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1180     ierr = MPIULong_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1181     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1182   }
1183   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
1184 
1185   /* load up the local column indices */
1186   nzmax = nz; /* th processor needs space a largest processor needs */
1187   ierr  = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1188   ierr  = PetscMalloc1(nzmax+1,&column_indices);CHKERRQ(ierr);
1189   cnt   = 0;
1190   for (i=0; i<mat->rmap->n; i++) {
1191     for (j=B->i[i]; j<B->i[i+1]; j++) {
1192       if ((col = garray[B->j[j]]) > cstart) break;
1193       column_indices[cnt++] = col;
1194     }
1195     for (k=A->i[i]; k<A->i[i+1]; k++) column_indices[cnt++] = A->j[k] + cstart;
1196     for (; j<B->i[i+1]; j++) column_indices[cnt++] = garray[B->j[j]];
1197   }
1198   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);
1199 
1200   /* store the column indices to the file */
1201   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1202   if (!rank) {
1203     MPI_Status status;
1204     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1205     for (i=1; i<size; i++) {
1206       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1207       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1208       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1209       ierr = MPIULong_Recv(column_indices,rnz,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1210       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1211     }
1212     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1213   } else {
1214     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1215     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1216     ierr = MPIULong_Send(column_indices,nz,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1217     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1218   }
1219   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1220 
1221   /* load up the local column values */
1222   ierr = PetscMalloc1(nzmax+1,&column_values);CHKERRQ(ierr);
1223   cnt  = 0;
1224   for (i=0; i<mat->rmap->n; i++) {
1225     for (j=B->i[i]; j<B->i[i+1]; j++) {
1226       if (garray[B->j[j]] > cstart) break;
1227       column_values[cnt++] = B->a[j];
1228     }
1229     for (k=A->i[i]; k<A->i[i+1]; k++) column_values[cnt++] = A->a[k];
1230     for (; j<B->i[i+1]; j++) column_values[cnt++] = B->a[j];
1231   }
1232   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);
1233 
1234   /* store the column values to the file */
1235   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1236   if (!rank) {
1237     MPI_Status status;
1238     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1239     for (i=1; i<size; i++) {
1240       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1241       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1242       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1243       ierr = MPIULong_Recv(column_values,rnz,MPIU_SCALAR,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1244       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1245     }
1246     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1247   } else {
1248     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1249     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1250     ierr = MPIULong_Send(column_values,nz,MPIU_SCALAR,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1251     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1252   }
1253   ierr = PetscFree(column_values);CHKERRQ(ierr);
1254 
1255   ierr = PetscViewerBinaryGetInfoPointer(viewer,&file);CHKERRQ(ierr);
1256   if (file) fprintf(file,"-matload_block_size %d\n",(int)PetscAbs(mat->rmap->bs));
1257   PetscFunctionReturn(0);
1258 }
1259 
1260 #include <petscdraw.h>
1261 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1262 {
1263   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1264   PetscErrorCode    ierr;
1265   PetscMPIInt       rank = aij->rank,size = aij->size;
1266   PetscBool         isdraw,iascii,isbinary;
1267   PetscViewer       sviewer;
1268   PetscViewerFormat format;
1269 
1270   PetscFunctionBegin;
1271   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1272   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1273   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1274   if (iascii) {
1275     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1276     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1277       MatInfo   info;
1278       PetscBool inodes;
1279 
1280       ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1281       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1282       ierr = MatInodeGetInodeSizes(aij->A,NULL,(PetscInt**)&inodes,NULL);CHKERRQ(ierr);
1283       ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr);
1284       if (!inodes) {
1285         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1286                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1287       } else {
1288         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1289                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1290       }
1291       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1292       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1293       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1294       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1295       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1296       ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr);
1297       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1298       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1299       PetscFunctionReturn(0);
1300     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1301       PetscInt inodecount,inodelimit,*inodes;
1302       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1303       if (inodes) {
1304         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1305       } else {
1306         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1307       }
1308       PetscFunctionReturn(0);
1309     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1310       PetscFunctionReturn(0);
1311     }
1312   } else if (isbinary) {
1313     if (size == 1) {
1314       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1315       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1316     } else {
1317       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1318     }
1319     PetscFunctionReturn(0);
1320   } else if (isdraw) {
1321     PetscDraw draw;
1322     PetscBool isnull;
1323     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1324     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr);
1325     if (isnull) PetscFunctionReturn(0);
1326   }
1327 
1328   {
1329     /* assemble the entire matrix onto first processor. */
1330     Mat        A;
1331     Mat_SeqAIJ *Aloc;
1332     PetscInt   M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1333     MatScalar  *a;
1334 
1335     ierr = MatCreate(PetscObjectComm((PetscObject)mat),&A);CHKERRQ(ierr);
1336     if (!rank) {
1337       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1338     } else {
1339       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1340     }
1341     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1342     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1343     ierr = MatMPIAIJSetPreallocation(A,0,NULL,0,NULL);CHKERRQ(ierr);
1344     ierr = MatSetOption(A,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
1345     ierr = PetscLogObjectParent((PetscObject)mat,(PetscObject)A);CHKERRQ(ierr);
1346 
1347     /* copy over the A part */
1348     Aloc = (Mat_SeqAIJ*)aij->A->data;
1349     m    = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1350     row  = mat->rmap->rstart;
1351     for (i=0; i<ai[m]; i++) aj[i] += mat->cmap->rstart;
1352     for (i=0; i<m; i++) {
1353       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1354       row++;
1355       a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1356     }
1357     aj = Aloc->j;
1358     for (i=0; i<ai[m]; i++) aj[i] -= mat->cmap->rstart;
1359 
1360     /* copy over the B part */
1361     Aloc = (Mat_SeqAIJ*)aij->B->data;
1362     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1363     row  = mat->rmap->rstart;
1364     ierr = PetscMalloc1(ai[m]+1,&cols);CHKERRQ(ierr);
1365     ct   = cols;
1366     for (i=0; i<ai[m]; i++) cols[i] = aij->garray[aj[i]];
1367     for (i=0; i<m; i++) {
1368       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1369       row++;
1370       a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1371     }
1372     ierr = PetscFree(ct);CHKERRQ(ierr);
1373     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1374     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1375     /*
1376        Everyone has to call to draw the matrix since the graphics waits are
1377        synchronized across all processors that share the PetscDraw object
1378     */
1379     ierr = PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer);CHKERRQ(ierr);
1380     if (!rank) {
1381       ierr = PetscObjectSetName((PetscObject)((Mat_MPIAIJ*)(A->data))->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1382       ierr = MatView_SeqAIJ(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1383     }
1384     ierr = PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer);CHKERRQ(ierr);
1385     ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1386     ierr = MatDestroy(&A);CHKERRQ(ierr);
1387   }
1388   PetscFunctionReturn(0);
1389 }
1390 
1391 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1392 {
1393   PetscErrorCode ierr;
1394   PetscBool      iascii,isdraw,issocket,isbinary;
1395 
1396   PetscFunctionBegin;
1397   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1398   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1399   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1400   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSOCKET,&issocket);CHKERRQ(ierr);
1401   if (iascii || isdraw || isbinary || issocket) {
1402     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1403   }
1404   PetscFunctionReturn(0);
1405 }
1406 
1407 PetscErrorCode MatSOR_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1408 {
1409   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1410   PetscErrorCode ierr;
1411   Vec            bb1 = 0;
1412   PetscBool      hasop;
1413 
1414   PetscFunctionBegin;
1415   if (flag == SOR_APPLY_UPPER) {
1416     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1417     PetscFunctionReturn(0);
1418   }
1419 
1420   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) {
1421     ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1422   }
1423 
1424   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP) {
1425     if (flag & SOR_ZERO_INITIAL_GUESS) {
1426       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1427       its--;
1428     }
1429 
1430     while (its--) {
1431       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1432       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1433 
1434       /* update rhs: bb1 = bb - B*x */
1435       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1436       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1437 
1438       /* local sweep */
1439       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1440     }
1441   } else if (flag & SOR_LOCAL_FORWARD_SWEEP) {
1442     if (flag & SOR_ZERO_INITIAL_GUESS) {
1443       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1444       its--;
1445     }
1446     while (its--) {
1447       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1448       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1449 
1450       /* update rhs: bb1 = bb - B*x */
1451       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1452       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1453 
1454       /* local sweep */
1455       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1456     }
1457   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP) {
1458     if (flag & SOR_ZERO_INITIAL_GUESS) {
1459       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1460       its--;
1461     }
1462     while (its--) {
1463       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1464       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1465 
1466       /* update rhs: bb1 = bb - B*x */
1467       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1468       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1469 
1470       /* local sweep */
1471       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1472     }
1473   } else if (flag & SOR_EISENSTAT) {
1474     Vec xx1;
1475 
1476     ierr = VecDuplicate(bb,&xx1);CHKERRQ(ierr);
1477     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP),fshift,lits,1,xx);CHKERRQ(ierr);
1478 
1479     ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1480     ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1481     if (!mat->diag) {
1482       ierr = MatCreateVecs(matin,&mat->diag,NULL);CHKERRQ(ierr);
1483       ierr = MatGetDiagonal(matin,mat->diag);CHKERRQ(ierr);
1484     }
1485     ierr = MatHasOperation(matin,MATOP_MULT_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr);
1486     if (hasop) {
1487       ierr = MatMultDiagonalBlock(matin,xx,bb1);CHKERRQ(ierr);
1488     } else {
1489       ierr = VecPointwiseMult(bb1,mat->diag,xx);CHKERRQ(ierr);
1490     }
1491     ierr = VecAYPX(bb1,(omega-2.0)/omega,bb);CHKERRQ(ierr);
1492 
1493     ierr = MatMultAdd(mat->B,mat->lvec,bb1,bb1);CHKERRQ(ierr);
1494 
1495     /* local sweep */
1496     ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP),fshift,lits,1,xx1);CHKERRQ(ierr);
1497     ierr = VecAXPY(xx,1.0,xx1);CHKERRQ(ierr);
1498     ierr = VecDestroy(&xx1);CHKERRQ(ierr);
1499   } else SETERRQ(PetscObjectComm((PetscObject)matin),PETSC_ERR_SUP,"Parallel SOR not supported");
1500 
1501   ierr = VecDestroy(&bb1);CHKERRQ(ierr);
1502 
1503   matin->factorerrortype = mat->A->factorerrortype;
1504   PetscFunctionReturn(0);
1505 }
1506 
1507 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1508 {
1509   Mat            aA,aB,Aperm;
1510   const PetscInt *rwant,*cwant,*gcols,*ai,*bi,*aj,*bj;
1511   PetscScalar    *aa,*ba;
1512   PetscInt       i,j,m,n,ng,anz,bnz,*dnnz,*onnz,*tdnnz,*tonnz,*rdest,*cdest,*work,*gcdest;
1513   PetscSF        rowsf,sf;
1514   IS             parcolp = NULL;
1515   PetscBool      done;
1516   PetscErrorCode ierr;
1517 
1518   PetscFunctionBegin;
1519   ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr);
1520   ierr = ISGetIndices(rowp,&rwant);CHKERRQ(ierr);
1521   ierr = ISGetIndices(colp,&cwant);CHKERRQ(ierr);
1522   ierr = PetscMalloc3(PetscMax(m,n),&work,m,&rdest,n,&cdest);CHKERRQ(ierr);
1523 
1524   /* Invert row permutation to find out where my rows should go */
1525   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&rowsf);CHKERRQ(ierr);
1526   ierr = PetscSFSetGraphLayout(rowsf,A->rmap,A->rmap->n,NULL,PETSC_OWN_POINTER,rwant);CHKERRQ(ierr);
1527   ierr = PetscSFSetFromOptions(rowsf);CHKERRQ(ierr);
1528   for (i=0; i<m; i++) work[i] = A->rmap->rstart + i;
1529   ierr = PetscSFReduceBegin(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1530   ierr = PetscSFReduceEnd(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1531 
1532   /* Invert column permutation to find out where my columns should go */
1533   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1534   ierr = PetscSFSetGraphLayout(sf,A->cmap,A->cmap->n,NULL,PETSC_OWN_POINTER,cwant);CHKERRQ(ierr);
1535   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1536   for (i=0; i<n; i++) work[i] = A->cmap->rstart + i;
1537   ierr = PetscSFReduceBegin(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1538   ierr = PetscSFReduceEnd(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1539   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1540 
1541   ierr = ISRestoreIndices(rowp,&rwant);CHKERRQ(ierr);
1542   ierr = ISRestoreIndices(colp,&cwant);CHKERRQ(ierr);
1543   ierr = MatMPIAIJGetSeqAIJ(A,&aA,&aB,&gcols);CHKERRQ(ierr);
1544 
1545   /* Find out where my gcols should go */
1546   ierr = MatGetSize(aB,NULL,&ng);CHKERRQ(ierr);
1547   ierr = PetscMalloc1(ng,&gcdest);CHKERRQ(ierr);
1548   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1549   ierr = PetscSFSetGraphLayout(sf,A->cmap,ng,NULL,PETSC_OWN_POINTER,gcols);CHKERRQ(ierr);
1550   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1551   ierr = PetscSFBcastBegin(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1552   ierr = PetscSFBcastEnd(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1553   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1554 
1555   ierr = PetscCalloc4(m,&dnnz,m,&onnz,m,&tdnnz,m,&tonnz);CHKERRQ(ierr);
1556   ierr = MatGetRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1557   ierr = MatGetRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1558   for (i=0; i<m; i++) {
1559     PetscInt row = rdest[i],rowner;
1560     ierr = PetscLayoutFindOwner(A->rmap,row,&rowner);CHKERRQ(ierr);
1561     for (j=ai[i]; j<ai[i+1]; j++) {
1562       PetscInt cowner,col = cdest[aj[j]];
1563       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr); /* Could build an index for the columns to eliminate this search */
1564       if (rowner == cowner) dnnz[i]++;
1565       else onnz[i]++;
1566     }
1567     for (j=bi[i]; j<bi[i+1]; j++) {
1568       PetscInt cowner,col = gcdest[bj[j]];
1569       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr);
1570       if (rowner == cowner) dnnz[i]++;
1571       else onnz[i]++;
1572     }
1573   }
1574   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1575   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1576   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1577   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1578   ierr = PetscSFDestroy(&rowsf);CHKERRQ(ierr);
1579 
1580   ierr = MatCreateAIJ(PetscObjectComm((PetscObject)A),A->rmap->n,A->cmap->n,A->rmap->N,A->cmap->N,0,tdnnz,0,tonnz,&Aperm);CHKERRQ(ierr);
1581   ierr = MatSeqAIJGetArray(aA,&aa);CHKERRQ(ierr);
1582   ierr = MatSeqAIJGetArray(aB,&ba);CHKERRQ(ierr);
1583   for (i=0; i<m; i++) {
1584     PetscInt *acols = dnnz,*bcols = onnz; /* Repurpose now-unneeded arrays */
1585     PetscInt j0,rowlen;
1586     rowlen = ai[i+1] - ai[i];
1587     for (j0=j=0; j<rowlen; j0=j) { /* rowlen could be larger than number of rows m, so sum in batches */
1588       for ( ; j<PetscMin(rowlen,j0+m); j++) acols[j-j0] = cdest[aj[ai[i]+j]];
1589       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,acols,aa+ai[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1590     }
1591     rowlen = bi[i+1] - bi[i];
1592     for (j0=j=0; j<rowlen; j0=j) {
1593       for ( ; j<PetscMin(rowlen,j0+m); j++) bcols[j-j0] = gcdest[bj[bi[i]+j]];
1594       ierr = MatSetValues(Aperm,1,&rdest[i],j-j0,bcols,ba+bi[i]+j0,INSERT_VALUES);CHKERRQ(ierr);
1595     }
1596   }
1597   ierr = MatAssemblyBegin(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1598   ierr = MatAssemblyEnd(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1599   ierr = MatRestoreRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1600   ierr = MatRestoreRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1601   ierr = MatSeqAIJRestoreArray(aA,&aa);CHKERRQ(ierr);
1602   ierr = MatSeqAIJRestoreArray(aB,&ba);CHKERRQ(ierr);
1603   ierr = PetscFree4(dnnz,onnz,tdnnz,tonnz);CHKERRQ(ierr);
1604   ierr = PetscFree3(work,rdest,cdest);CHKERRQ(ierr);
1605   ierr = PetscFree(gcdest);CHKERRQ(ierr);
1606   if (parcolp) {ierr = ISDestroy(&colp);CHKERRQ(ierr);}
1607   *B = Aperm;
1608   PetscFunctionReturn(0);
1609 }
1610 
1611 PetscErrorCode  MatGetGhosts_MPIAIJ(Mat mat,PetscInt *nghosts,const PetscInt *ghosts[])
1612 {
1613   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1614   PetscErrorCode ierr;
1615 
1616   PetscFunctionBegin;
1617   ierr = MatGetSize(aij->B,NULL,nghosts);CHKERRQ(ierr);
1618   if (ghosts) *ghosts = aij->garray;
1619   PetscFunctionReturn(0);
1620 }
1621 
1622 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1623 {
1624   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1625   Mat            A    = mat->A,B = mat->B;
1626   PetscErrorCode ierr;
1627   PetscReal      isend[5],irecv[5];
1628 
1629   PetscFunctionBegin;
1630   info->block_size = 1.0;
1631   ierr             = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1632 
1633   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1634   isend[3] = info->memory;  isend[4] = info->mallocs;
1635 
1636   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1637 
1638   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1639   isend[3] += info->memory;  isend[4] += info->mallocs;
1640   if (flag == MAT_LOCAL) {
1641     info->nz_used      = isend[0];
1642     info->nz_allocated = isend[1];
1643     info->nz_unneeded  = isend[2];
1644     info->memory       = isend[3];
1645     info->mallocs      = isend[4];
1646   } else if (flag == MAT_GLOBAL_MAX) {
1647     ierr = MPIU_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1648 
1649     info->nz_used      = irecv[0];
1650     info->nz_allocated = irecv[1];
1651     info->nz_unneeded  = irecv[2];
1652     info->memory       = irecv[3];
1653     info->mallocs      = irecv[4];
1654   } else if (flag == MAT_GLOBAL_SUM) {
1655     ierr = MPIU_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1656 
1657     info->nz_used      = irecv[0];
1658     info->nz_allocated = irecv[1];
1659     info->nz_unneeded  = irecv[2];
1660     info->memory       = irecv[3];
1661     info->mallocs      = irecv[4];
1662   }
1663   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1664   info->fill_ratio_needed = 0;
1665   info->factor_mallocs    = 0;
1666   PetscFunctionReturn(0);
1667 }
1668 
1669 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscBool flg)
1670 {
1671   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1672   PetscErrorCode ierr;
1673 
1674   PetscFunctionBegin;
1675   switch (op) {
1676   case MAT_NEW_NONZERO_LOCATIONS:
1677   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1678   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1679   case MAT_KEEP_NONZERO_PATTERN:
1680   case MAT_NEW_NONZERO_LOCATION_ERR:
1681   case MAT_USE_INODES:
1682   case MAT_IGNORE_ZERO_ENTRIES:
1683     MatCheckPreallocated(A,1);
1684     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1685     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1686     break;
1687   case MAT_ROW_ORIENTED:
1688     MatCheckPreallocated(A,1);
1689     a->roworiented = flg;
1690 
1691     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1692     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1693     break;
1694   case MAT_NEW_DIAGONALS:
1695     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1696     break;
1697   case MAT_IGNORE_OFF_PROC_ENTRIES:
1698     a->donotstash = flg;
1699     break;
1700   case MAT_SPD:
1701     A->spd_set = PETSC_TRUE;
1702     A->spd     = flg;
1703     if (flg) {
1704       A->symmetric                  = PETSC_TRUE;
1705       A->structurally_symmetric     = PETSC_TRUE;
1706       A->symmetric_set              = PETSC_TRUE;
1707       A->structurally_symmetric_set = PETSC_TRUE;
1708     }
1709     break;
1710   case MAT_SYMMETRIC:
1711     MatCheckPreallocated(A,1);
1712     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1713     break;
1714   case MAT_STRUCTURALLY_SYMMETRIC:
1715     MatCheckPreallocated(A,1);
1716     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1717     break;
1718   case MAT_HERMITIAN:
1719     MatCheckPreallocated(A,1);
1720     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1721     break;
1722   case MAT_SYMMETRY_ETERNAL:
1723     MatCheckPreallocated(A,1);
1724     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1725     break;
1726   case MAT_SUBMAT_SINGLEIS:
1727     A->submat_singleis = flg;
1728     break;
1729   case MAT_STRUCTURE_ONLY:
1730     /* The option is handled directly by MatSetOption() */
1731     break;
1732   default:
1733     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"unknown option %d",op);
1734   }
1735   PetscFunctionReturn(0);
1736 }
1737 
1738 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1739 {
1740   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1741   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1742   PetscErrorCode ierr;
1743   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1744   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1745   PetscInt       *cmap,*idx_p;
1746 
1747   PetscFunctionBegin;
1748   if (mat->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Already active");
1749   mat->getrowactive = PETSC_TRUE;
1750 
1751   if (!mat->rowvalues && (idx || v)) {
1752     /*
1753         allocate enough space to hold information from the longest row.
1754     */
1755     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1756     PetscInt   max = 1,tmp;
1757     for (i=0; i<matin->rmap->n; i++) {
1758       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1759       if (max < tmp) max = tmp;
1760     }
1761     ierr = PetscMalloc2(max,&mat->rowvalues,max,&mat->rowindices);CHKERRQ(ierr);
1762   }
1763 
1764   if (row < rstart || row >= rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only local rows");
1765   lrow = row - rstart;
1766 
1767   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1768   if (!v)   {pvA = 0; pvB = 0;}
1769   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1770   ierr  = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1771   ierr  = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1772   nztot = nzA + nzB;
1773 
1774   cmap = mat->garray;
1775   if (v  || idx) {
1776     if (nztot) {
1777       /* Sort by increasing column numbers, assuming A and B already sorted */
1778       PetscInt imark = -1;
1779       if (v) {
1780         *v = v_p = mat->rowvalues;
1781         for (i=0; i<nzB; i++) {
1782           if (cmap[cworkB[i]] < cstart) v_p[i] = vworkB[i];
1783           else break;
1784         }
1785         imark = i;
1786         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1787         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1788       }
1789       if (idx) {
1790         *idx = idx_p = mat->rowindices;
1791         if (imark > -1) {
1792           for (i=0; i<imark; i++) {
1793             idx_p[i] = cmap[cworkB[i]];
1794           }
1795         } else {
1796           for (i=0; i<nzB; i++) {
1797             if (cmap[cworkB[i]] < cstart) idx_p[i] = cmap[cworkB[i]];
1798             else break;
1799           }
1800           imark = i;
1801         }
1802         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1803         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1804       }
1805     } else {
1806       if (idx) *idx = 0;
1807       if (v)   *v   = 0;
1808     }
1809   }
1810   *nz  = nztot;
1811   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1812   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1813   PetscFunctionReturn(0);
1814 }
1815 
1816 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1817 {
1818   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1819 
1820   PetscFunctionBegin;
1821   if (!aij->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1822   aij->getrowactive = PETSC_FALSE;
1823   PetscFunctionReturn(0);
1824 }
1825 
1826 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1827 {
1828   Mat_MPIAIJ     *aij  = (Mat_MPIAIJ*)mat->data;
1829   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1830   PetscErrorCode ierr;
1831   PetscInt       i,j,cstart = mat->cmap->rstart;
1832   PetscReal      sum = 0.0;
1833   MatScalar      *v;
1834 
1835   PetscFunctionBegin;
1836   if (aij->size == 1) {
1837     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1838   } else {
1839     if (type == NORM_FROBENIUS) {
1840       v = amat->a;
1841       for (i=0; i<amat->nz; i++) {
1842         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1843       }
1844       v = bmat->a;
1845       for (i=0; i<bmat->nz; i++) {
1846         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1847       }
1848       ierr  = MPIU_Allreduce(&sum,norm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1849       *norm = PetscSqrtReal(*norm);
1850       ierr = PetscLogFlops(2*amat->nz+2*bmat->nz);CHKERRQ(ierr);
1851     } else if (type == NORM_1) { /* max column norm */
1852       PetscReal *tmp,*tmp2;
1853       PetscInt  *jj,*garray = aij->garray;
1854       ierr  = PetscCalloc1(mat->cmap->N+1,&tmp);CHKERRQ(ierr);
1855       ierr  = PetscMalloc1(mat->cmap->N+1,&tmp2);CHKERRQ(ierr);
1856       *norm = 0.0;
1857       v     = amat->a; jj = amat->j;
1858       for (j=0; j<amat->nz; j++) {
1859         tmp[cstart + *jj++] += PetscAbsScalar(*v);  v++;
1860       }
1861       v = bmat->a; jj = bmat->j;
1862       for (j=0; j<bmat->nz; j++) {
1863         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1864       }
1865       ierr = MPIU_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1866       for (j=0; j<mat->cmap->N; j++) {
1867         if (tmp2[j] > *norm) *norm = tmp2[j];
1868       }
1869       ierr = PetscFree(tmp);CHKERRQ(ierr);
1870       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1871       ierr = PetscLogFlops(PetscMax(amat->nz+bmat->nz-1,0));CHKERRQ(ierr);
1872     } else if (type == NORM_INFINITY) { /* max row norm */
1873       PetscReal ntemp = 0.0;
1874       for (j=0; j<aij->A->rmap->n; j++) {
1875         v   = amat->a + amat->i[j];
1876         sum = 0.0;
1877         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1878           sum += PetscAbsScalar(*v); v++;
1879         }
1880         v = bmat->a + bmat->i[j];
1881         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1882           sum += PetscAbsScalar(*v); v++;
1883         }
1884         if (sum > ntemp) ntemp = sum;
1885       }
1886       ierr = MPIU_Allreduce(&ntemp,norm,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1887       ierr = PetscLogFlops(PetscMax(amat->nz+bmat->nz-1,0));CHKERRQ(ierr);
1888     } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"No support for two norm");
1889   }
1890   PetscFunctionReturn(0);
1891 }
1892 
1893 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
1894 {
1895   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1896   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
1897   PetscErrorCode ierr;
1898   PetscInt       M      = A->rmap->N,N = A->cmap->N,ma,na,mb,nb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i;
1899   PetscInt       cstart = A->cmap->rstart,ncol;
1900   Mat            B;
1901   MatScalar      *array;
1902 
1903   PetscFunctionBegin;
1904   if (reuse == MAT_INPLACE_MATRIX && M != N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
1905 
1906   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n; nb = a->B->cmap->n;
1907   ai = Aloc->i; aj = Aloc->j;
1908   bi = Bloc->i; bj = Bloc->j;
1909   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1910     PetscInt             *d_nnz,*g_nnz,*o_nnz;
1911     PetscSFNode          *oloc;
1912     PETSC_UNUSED PetscSF sf;
1913 
1914     ierr = PetscMalloc4(na,&d_nnz,na,&o_nnz,nb,&g_nnz,nb,&oloc);CHKERRQ(ierr);
1915     /* compute d_nnz for preallocation */
1916     ierr = PetscMemzero(d_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1917     for (i=0; i<ai[ma]; i++) {
1918       d_nnz[aj[i]]++;
1919       aj[i] += cstart; /* global col index to be used by MatSetValues() */
1920     }
1921     /* compute local off-diagonal contributions */
1922     ierr = PetscMemzero(g_nnz,nb*sizeof(PetscInt));CHKERRQ(ierr);
1923     for (i=0; i<bi[ma]; i++) g_nnz[bj[i]]++;
1924     /* map those to global */
1925     ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1926     ierr = PetscSFSetGraphLayout(sf,A->cmap,nb,NULL,PETSC_USE_POINTER,a->garray);CHKERRQ(ierr);
1927     ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1928     ierr = PetscMemzero(o_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
1929     ierr = PetscSFReduceBegin(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1930     ierr = PetscSFReduceEnd(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
1931     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1932 
1933     ierr = MatCreate(PetscObjectComm((PetscObject)A),&B);CHKERRQ(ierr);
1934     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
1935     ierr = MatSetBlockSizes(B,PetscAbs(A->cmap->bs),PetscAbs(A->rmap->bs));CHKERRQ(ierr);
1936     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
1937     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
1938     ierr = PetscFree4(d_nnz,o_nnz,g_nnz,oloc);CHKERRQ(ierr);
1939   } else {
1940     B    = *matout;
1941     ierr = MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
1942     for (i=0; i<ai[ma]; i++) aj[i] += cstart; /* global col index to be used by MatSetValues() */
1943   }
1944 
1945   /* copy over the A part */
1946   array = Aloc->a;
1947   row   = A->rmap->rstart;
1948   for (i=0; i<ma; i++) {
1949     ncol = ai[i+1]-ai[i];
1950     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1951     row++;
1952     array += ncol; aj += ncol;
1953   }
1954   aj = Aloc->j;
1955   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
1956 
1957   /* copy over the B part */
1958   ierr  = PetscCalloc1(bi[mb],&cols);CHKERRQ(ierr);
1959   array = Bloc->a;
1960   row   = A->rmap->rstart;
1961   for (i=0; i<bi[mb]; i++) cols[i] = a->garray[bj[i]];
1962   cols_tmp = cols;
1963   for (i=0; i<mb; i++) {
1964     ncol = bi[i+1]-bi[i];
1965     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1966     row++;
1967     array += ncol; cols_tmp += ncol;
1968   }
1969   ierr = PetscFree(cols);CHKERRQ(ierr);
1970 
1971   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1972   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1973   if (reuse == MAT_INITIAL_MATRIX || reuse == MAT_REUSE_MATRIX) {
1974     *matout = B;
1975   } else {
1976     ierr = MatHeaderMerge(A,&B);CHKERRQ(ierr);
1977   }
1978   PetscFunctionReturn(0);
1979 }
1980 
1981 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
1982 {
1983   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1984   Mat            a    = aij->A,b = aij->B;
1985   PetscErrorCode ierr;
1986   PetscInt       s1,s2,s3;
1987 
1988   PetscFunctionBegin;
1989   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
1990   if (rr) {
1991     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
1992     if (s1!=s3) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
1993     /* Overlap communication with computation. */
1994     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1995   }
1996   if (ll) {
1997     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
1998     if (s1!=s2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
1999     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
2000   }
2001   /* scale  the diagonal block */
2002   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
2003 
2004   if (rr) {
2005     /* Do a scatter end and then right scale the off-diagonal block */
2006     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2007     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
2008   }
2009   PetscFunctionReturn(0);
2010 }
2011 
2012 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2013 {
2014   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2015   PetscErrorCode ierr;
2016 
2017   PetscFunctionBegin;
2018   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
2019   PetscFunctionReturn(0);
2020 }
2021 
2022 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscBool  *flag)
2023 {
2024   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
2025   Mat            a,b,c,d;
2026   PetscBool      flg;
2027   PetscErrorCode ierr;
2028 
2029   PetscFunctionBegin;
2030   a = matA->A; b = matA->B;
2031   c = matB->A; d = matB->B;
2032 
2033   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
2034   if (flg) {
2035     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
2036   }
2037   ierr = MPIU_Allreduce(&flg,flag,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
2038   PetscFunctionReturn(0);
2039 }
2040 
2041 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
2042 {
2043   PetscErrorCode ierr;
2044   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2045   Mat_MPIAIJ     *b = (Mat_MPIAIJ*)B->data;
2046 
2047   PetscFunctionBegin;
2048   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2049   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2050     /* because of the column compression in the off-processor part of the matrix a->B,
2051        the number of columns in a->B and b->B may be different, hence we cannot call
2052        the MatCopy() directly on the two parts. If need be, we can provide a more
2053        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2054        then copying the submatrices */
2055     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
2056   } else {
2057     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
2058     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
2059   }
2060   ierr = PetscObjectStateIncrease((PetscObject)B);CHKERRQ(ierr);
2061   PetscFunctionReturn(0);
2062 }
2063 
2064 PetscErrorCode MatSetUp_MPIAIJ(Mat A)
2065 {
2066   PetscErrorCode ierr;
2067 
2068   PetscFunctionBegin;
2069   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
2070   PetscFunctionReturn(0);
2071 }
2072 
2073 /*
2074    Computes the number of nonzeros per row needed for preallocation when X and Y
2075    have different nonzero structure.
2076 */
2077 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)
2078 {
2079   PetscInt       i,j,k,nzx,nzy;
2080 
2081   PetscFunctionBegin;
2082   /* Set the number of nonzeros in the new matrix */
2083   for (i=0; i<m; i++) {
2084     const PetscInt *xjj = xj+xi[i],*yjj = yj+yi[i];
2085     nzx = xi[i+1] - xi[i];
2086     nzy = yi[i+1] - yi[i];
2087     nnz[i] = 0;
2088     for (j=0,k=0; j<nzx; j++) {                   /* Point in X */
2089       for (; k<nzy && yltog[yjj[k]]<xltog[xjj[j]]; k++) nnz[i]++; /* Catch up to X */
2090       if (k<nzy && yltog[yjj[k]]==xltog[xjj[j]]) k++;             /* Skip duplicate */
2091       nnz[i]++;
2092     }
2093     for (; k<nzy; k++) nnz[i]++;
2094   }
2095   PetscFunctionReturn(0);
2096 }
2097 
2098 /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2099 static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y,const PetscInt *yltog,Mat X,const PetscInt *xltog,PetscInt *nnz)
2100 {
2101   PetscErrorCode ierr;
2102   PetscInt       m = Y->rmap->N;
2103   Mat_SeqAIJ     *x = (Mat_SeqAIJ*)X->data;
2104   Mat_SeqAIJ     *y = (Mat_SeqAIJ*)Y->data;
2105 
2106   PetscFunctionBegin;
2107   ierr = MatAXPYGetPreallocation_MPIX_private(m,x->i,x->j,xltog,y->i,y->j,yltog,nnz);CHKERRQ(ierr);
2108   PetscFunctionReturn(0);
2109 }
2110 
2111 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
2112 {
2113   PetscErrorCode ierr;
2114   Mat_MPIAIJ     *xx = (Mat_MPIAIJ*)X->data,*yy = (Mat_MPIAIJ*)Y->data;
2115   PetscBLASInt   bnz,one=1;
2116   Mat_SeqAIJ     *x,*y;
2117 
2118   PetscFunctionBegin;
2119   if (str == SAME_NONZERO_PATTERN) {
2120     PetscScalar alpha = a;
2121     x    = (Mat_SeqAIJ*)xx->A->data;
2122     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2123     y    = (Mat_SeqAIJ*)yy->A->data;
2124     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2125     x    = (Mat_SeqAIJ*)xx->B->data;
2126     y    = (Mat_SeqAIJ*)yy->B->data;
2127     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2128     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2129     ierr = PetscObjectStateIncrease((PetscObject)Y);CHKERRQ(ierr);
2130   } else if (str == SUBSET_NONZERO_PATTERN) { /* nonzeros of X is a subset of Y's */
2131     ierr = MatAXPY_Basic(Y,a,X,str);CHKERRQ(ierr);
2132   } else {
2133     Mat      B;
2134     PetscInt *nnz_d,*nnz_o;
2135     ierr = PetscMalloc1(yy->A->rmap->N,&nnz_d);CHKERRQ(ierr);
2136     ierr = PetscMalloc1(yy->B->rmap->N,&nnz_o);CHKERRQ(ierr);
2137     ierr = MatCreate(PetscObjectComm((PetscObject)Y),&B);CHKERRQ(ierr);
2138     ierr = PetscObjectSetName((PetscObject)B,((PetscObject)Y)->name);CHKERRQ(ierr);
2139     ierr = MatSetSizes(B,Y->rmap->n,Y->cmap->n,Y->rmap->N,Y->cmap->N);CHKERRQ(ierr);
2140     ierr = MatSetBlockSizesFromMats(B,Y,Y);CHKERRQ(ierr);
2141     ierr = MatSetType(B,MATMPIAIJ);CHKERRQ(ierr);
2142     ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr);
2143     ierr = MatAXPYGetPreallocation_MPIAIJ(yy->B,yy->garray,xx->B,xx->garray,nnz_o);CHKERRQ(ierr);
2144     ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr);
2145     ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);
2146     ierr = MatHeaderReplace(Y,&B);CHKERRQ(ierr);
2147     ierr = PetscFree(nnz_d);CHKERRQ(ierr);
2148     ierr = PetscFree(nnz_o);CHKERRQ(ierr);
2149   }
2150   PetscFunctionReturn(0);
2151 }
2152 
2153 extern PetscErrorCode  MatConjugate_SeqAIJ(Mat);
2154 
2155 PetscErrorCode  MatConjugate_MPIAIJ(Mat mat)
2156 {
2157 #if defined(PETSC_USE_COMPLEX)
2158   PetscErrorCode ierr;
2159   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2160 
2161   PetscFunctionBegin;
2162   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
2163   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
2164 #else
2165   PetscFunctionBegin;
2166 #endif
2167   PetscFunctionReturn(0);
2168 }
2169 
2170 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2171 {
2172   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2173   PetscErrorCode ierr;
2174 
2175   PetscFunctionBegin;
2176   ierr = MatRealPart(a->A);CHKERRQ(ierr);
2177   ierr = MatRealPart(a->B);CHKERRQ(ierr);
2178   PetscFunctionReturn(0);
2179 }
2180 
2181 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2182 {
2183   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2184   PetscErrorCode ierr;
2185 
2186   PetscFunctionBegin;
2187   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
2188   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
2189   PetscFunctionReturn(0);
2190 }
2191 
2192 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2193 {
2194   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2195   PetscErrorCode ierr;
2196   PetscInt       i,*idxb = 0;
2197   PetscScalar    *va,*vb;
2198   Vec            vtmp;
2199 
2200   PetscFunctionBegin;
2201   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2202   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2203   if (idx) {
2204     for (i=0; i<A->rmap->n; i++) {
2205       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2206     }
2207   }
2208 
2209   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2210   if (idx) {
2211     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2212   }
2213   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2214   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2215 
2216   for (i=0; i<A->rmap->n; i++) {
2217     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2218       va[i] = vb[i];
2219       if (idx) idx[i] = a->garray[idxb[i]];
2220     }
2221   }
2222 
2223   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2224   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2225   ierr = PetscFree(idxb);CHKERRQ(ierr);
2226   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2227   PetscFunctionReturn(0);
2228 }
2229 
2230 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2231 {
2232   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2233   PetscErrorCode ierr;
2234   PetscInt       i,*idxb = 0;
2235   PetscScalar    *va,*vb;
2236   Vec            vtmp;
2237 
2238   PetscFunctionBegin;
2239   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2240   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2241   if (idx) {
2242     for (i=0; i<A->cmap->n; i++) {
2243       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2244     }
2245   }
2246 
2247   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2248   if (idx) {
2249     ierr = PetscMalloc1(A->rmap->n,&idxb);CHKERRQ(ierr);
2250   }
2251   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2252   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2253 
2254   for (i=0; i<A->rmap->n; i++) {
2255     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2256       va[i] = vb[i];
2257       if (idx) idx[i] = a->garray[idxb[i]];
2258     }
2259   }
2260 
2261   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2262   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2263   ierr = PetscFree(idxb);CHKERRQ(ierr);
2264   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2265   PetscFunctionReturn(0);
2266 }
2267 
2268 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2269 {
2270   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2271   PetscInt       n      = A->rmap->n;
2272   PetscInt       cstart = A->cmap->rstart;
2273   PetscInt       *cmap  = mat->garray;
2274   PetscInt       *diagIdx, *offdiagIdx;
2275   Vec            diagV, offdiagV;
2276   PetscScalar    *a, *diagA, *offdiagA;
2277   PetscInt       r;
2278   PetscErrorCode ierr;
2279 
2280   PetscFunctionBegin;
2281   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2282   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &diagV);CHKERRQ(ierr);
2283   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &offdiagV);CHKERRQ(ierr);
2284   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2285   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2286   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2287   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2288   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2289   for (r = 0; r < n; ++r) {
2290     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2291       a[r]   = diagA[r];
2292       idx[r] = cstart + diagIdx[r];
2293     } else {
2294       a[r]   = offdiagA[r];
2295       idx[r] = cmap[offdiagIdx[r]];
2296     }
2297   }
2298   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2299   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2300   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2301   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2302   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2303   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2304   PetscFunctionReturn(0);
2305 }
2306 
2307 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2308 {
2309   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
2310   PetscInt       n      = A->rmap->n;
2311   PetscInt       cstart = A->cmap->rstart;
2312   PetscInt       *cmap  = mat->garray;
2313   PetscInt       *diagIdx, *offdiagIdx;
2314   Vec            diagV, offdiagV;
2315   PetscScalar    *a, *diagA, *offdiagA;
2316   PetscInt       r;
2317   PetscErrorCode ierr;
2318 
2319   PetscFunctionBegin;
2320   ierr = PetscMalloc2(n,&diagIdx,n,&offdiagIdx);CHKERRQ(ierr);
2321   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &diagV);CHKERRQ(ierr);
2322   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &offdiagV);CHKERRQ(ierr);
2323   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2324   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2325   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2326   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2327   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2328   for (r = 0; r < n; ++r) {
2329     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2330       a[r]   = diagA[r];
2331       idx[r] = cstart + diagIdx[r];
2332     } else {
2333       a[r]   = offdiagA[r];
2334       idx[r] = cmap[offdiagIdx[r]];
2335     }
2336   }
2337   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2338   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2339   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2340   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2341   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2342   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2343   PetscFunctionReturn(0);
2344 }
2345 
2346 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
2347 {
2348   PetscErrorCode ierr;
2349   Mat            *dummy;
2350 
2351   PetscFunctionBegin;
2352   ierr    = MatCreateSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
2353   *newmat = *dummy;
2354   ierr    = PetscFree(dummy);CHKERRQ(ierr);
2355   PetscFunctionReturn(0);
2356 }
2357 
2358 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
2359 {
2360   Mat_MPIAIJ     *a = (Mat_MPIAIJ*) A->data;
2361   PetscErrorCode ierr;
2362 
2363   PetscFunctionBegin;
2364   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
2365   A->factorerrortype = a->A->factorerrortype;
2366   PetscFunctionReturn(0);
2367 }
2368 
2369 static PetscErrorCode  MatSetRandom_MPIAIJ(Mat x,PetscRandom rctx)
2370 {
2371   PetscErrorCode ierr;
2372   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)x->data;
2373 
2374   PetscFunctionBegin;
2375   ierr = MatSetRandom(aij->A,rctx);CHKERRQ(ierr);
2376   ierr = MatSetRandom(aij->B,rctx);CHKERRQ(ierr);
2377   ierr = MatAssemblyBegin(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2378   ierr = MatAssemblyEnd(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2379   PetscFunctionReturn(0);
2380 }
2381 
2382 PetscErrorCode MatMPIAIJSetUseScalableIncreaseOverlap_MPIAIJ(Mat A,PetscBool sc)
2383 {
2384   PetscFunctionBegin;
2385   if (sc) A->ops->increaseoverlap = MatIncreaseOverlap_MPIAIJ_Scalable;
2386   else A->ops->increaseoverlap    = MatIncreaseOverlap_MPIAIJ;
2387   PetscFunctionReturn(0);
2388 }
2389 
2390 /*@
2391    MatMPIAIJSetUseScalableIncreaseOverlap - Determine if the matrix uses a scalable algorithm to compute the overlap
2392 
2393    Collective on Mat
2394 
2395    Input Parameters:
2396 +    A - the matrix
2397 -    sc - PETSC_TRUE indicates use the scalable algorithm (default is not to use the scalable algorithm)
2398 
2399  Level: advanced
2400 
2401 @*/
2402 PetscErrorCode MatMPIAIJSetUseScalableIncreaseOverlap(Mat A,PetscBool sc)
2403 {
2404   PetscErrorCode       ierr;
2405 
2406   PetscFunctionBegin;
2407   ierr = PetscTryMethod(A,"MatMPIAIJSetUseScalableIncreaseOverlap_C",(Mat,PetscBool),(A,sc));CHKERRQ(ierr);
2408   PetscFunctionReturn(0);
2409 }
2410 
2411 PetscErrorCode MatSetFromOptions_MPIAIJ(PetscOptionItems *PetscOptionsObject,Mat A)
2412 {
2413   PetscErrorCode       ierr;
2414   PetscBool            sc = PETSC_FALSE,flg;
2415 
2416   PetscFunctionBegin;
2417   ierr = PetscOptionsHead(PetscOptionsObject,"MPIAIJ options");CHKERRQ(ierr);
2418   ierr = PetscObjectOptionsBegin((PetscObject)A);
2419     if (A->ops->increaseoverlap == MatIncreaseOverlap_MPIAIJ_Scalable) sc = PETSC_TRUE;
2420     ierr = PetscOptionsBool("-mat_increase_overlap_scalable","Use a scalable algorithm to compute the overlap","MatIncreaseOverlap",sc,&sc,&flg);CHKERRQ(ierr);
2421     if (flg) {
2422       ierr = MatMPIAIJSetUseScalableIncreaseOverlap(A,sc);CHKERRQ(ierr);
2423     }
2424   ierr = PetscOptionsEnd();CHKERRQ(ierr);
2425   PetscFunctionReturn(0);
2426 }
2427 
2428 PetscErrorCode MatShift_MPIAIJ(Mat Y,PetscScalar a)
2429 {
2430   PetscErrorCode ierr;
2431   Mat_MPIAIJ     *maij = (Mat_MPIAIJ*)Y->data;
2432   Mat_SeqAIJ     *aij = (Mat_SeqAIJ*)maij->A->data;
2433 
2434   PetscFunctionBegin;
2435   if (!Y->preallocated) {
2436     ierr = MatMPIAIJSetPreallocation(Y,1,NULL,0,NULL);CHKERRQ(ierr);
2437   } else if (!aij->nz) {
2438     PetscInt nonew = aij->nonew;
2439     ierr = MatSeqAIJSetPreallocation(maij->A,1,NULL);CHKERRQ(ierr);
2440     aij->nonew = nonew;
2441   }
2442   ierr = MatShift_Basic(Y,a);CHKERRQ(ierr);
2443   PetscFunctionReturn(0);
2444 }
2445 
2446 PetscErrorCode MatMissingDiagonal_MPIAIJ(Mat A,PetscBool  *missing,PetscInt *d)
2447 {
2448   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2449   PetscErrorCode ierr;
2450 
2451   PetscFunctionBegin;
2452   if (A->rmap->n != A->cmap->n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only works for square matrices");
2453   ierr = MatMissingDiagonal(a->A,missing,d);CHKERRQ(ierr);
2454   if (d) {
2455     PetscInt rstart;
2456     ierr = MatGetOwnershipRange(A,&rstart,NULL);CHKERRQ(ierr);
2457     *d += rstart;
2458 
2459   }
2460   PetscFunctionReturn(0);
2461 }
2462 
2463 
2464 /* -------------------------------------------------------------------*/
2465 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
2466                                        MatGetRow_MPIAIJ,
2467                                        MatRestoreRow_MPIAIJ,
2468                                        MatMult_MPIAIJ,
2469                                 /* 4*/ MatMultAdd_MPIAIJ,
2470                                        MatMultTranspose_MPIAIJ,
2471                                        MatMultTransposeAdd_MPIAIJ,
2472                                        0,
2473                                        0,
2474                                        0,
2475                                 /*10*/ 0,
2476                                        0,
2477                                        0,
2478                                        MatSOR_MPIAIJ,
2479                                        MatTranspose_MPIAIJ,
2480                                 /*15*/ MatGetInfo_MPIAIJ,
2481                                        MatEqual_MPIAIJ,
2482                                        MatGetDiagonal_MPIAIJ,
2483                                        MatDiagonalScale_MPIAIJ,
2484                                        MatNorm_MPIAIJ,
2485                                 /*20*/ MatAssemblyBegin_MPIAIJ,
2486                                        MatAssemblyEnd_MPIAIJ,
2487                                        MatSetOption_MPIAIJ,
2488                                        MatZeroEntries_MPIAIJ,
2489                                 /*24*/ MatZeroRows_MPIAIJ,
2490                                        0,
2491                                        0,
2492                                        0,
2493                                        0,
2494                                 /*29*/ MatSetUp_MPIAIJ,
2495                                        0,
2496                                        0,
2497                                        MatGetDiagonalBlock_MPIAIJ,
2498                                        0,
2499                                 /*34*/ MatDuplicate_MPIAIJ,
2500                                        0,
2501                                        0,
2502                                        0,
2503                                        0,
2504                                 /*39*/ MatAXPY_MPIAIJ,
2505                                        MatCreateSubMatrices_MPIAIJ,
2506                                        MatIncreaseOverlap_MPIAIJ,
2507                                        MatGetValues_MPIAIJ,
2508                                        MatCopy_MPIAIJ,
2509                                 /*44*/ MatGetRowMax_MPIAIJ,
2510                                        MatScale_MPIAIJ,
2511                                        MatShift_MPIAIJ,
2512                                        MatDiagonalSet_MPIAIJ,
2513                                        MatZeroRowsColumns_MPIAIJ,
2514                                 /*49*/ MatSetRandom_MPIAIJ,
2515                                        0,
2516                                        0,
2517                                        0,
2518                                        0,
2519                                 /*54*/ MatFDColoringCreate_MPIXAIJ,
2520                                        0,
2521                                        MatSetUnfactored_MPIAIJ,
2522                                        MatPermute_MPIAIJ,
2523                                        0,
2524                                 /*59*/ MatCreateSubMatrix_MPIAIJ,
2525                                        MatDestroy_MPIAIJ,
2526                                        MatView_MPIAIJ,
2527                                        0,
2528                                        MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ,
2529                                 /*64*/ MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ,
2530                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
2531                                        0,
2532                                        0,
2533                                        0,
2534                                 /*69*/ MatGetRowMaxAbs_MPIAIJ,
2535                                        MatGetRowMinAbs_MPIAIJ,
2536                                        0,
2537                                        0,
2538                                        0,
2539                                        0,
2540                                 /*75*/ MatFDColoringApply_AIJ,
2541                                        MatSetFromOptions_MPIAIJ,
2542                                        0,
2543                                        0,
2544                                        MatFindZeroDiagonals_MPIAIJ,
2545                                 /*80*/ 0,
2546                                        0,
2547                                        0,
2548                                 /*83*/ MatLoad_MPIAIJ,
2549                                        0,
2550                                        0,
2551                                        0,
2552                                        0,
2553                                        0,
2554                                 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
2555                                        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
2556                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
2557                                        MatPtAP_MPIAIJ_MPIAIJ,
2558                                        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
2559                                 /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
2560                                        0,
2561                                        0,
2562                                        0,
2563                                        0,
2564                                 /*99*/ 0,
2565                                        0,
2566                                        0,
2567                                        MatConjugate_MPIAIJ,
2568                                        0,
2569                                 /*104*/MatSetValuesRow_MPIAIJ,
2570                                        MatRealPart_MPIAIJ,
2571                                        MatImaginaryPart_MPIAIJ,
2572                                        0,
2573                                        0,
2574                                 /*109*/0,
2575                                        0,
2576                                        MatGetRowMin_MPIAIJ,
2577                                        0,
2578                                        MatMissingDiagonal_MPIAIJ,
2579                                 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
2580                                        0,
2581                                        MatGetGhosts_MPIAIJ,
2582                                        0,
2583                                        0,
2584                                 /*119*/0,
2585                                        0,
2586                                        0,
2587                                        0,
2588                                        MatGetMultiProcBlock_MPIAIJ,
2589                                 /*124*/MatFindNonzeroRows_MPIAIJ,
2590                                        MatGetColumnNorms_MPIAIJ,
2591                                        MatInvertBlockDiagonal_MPIAIJ,
2592                                        0,
2593                                        MatCreateSubMatricesMPI_MPIAIJ,
2594                                 /*129*/0,
2595                                        MatTransposeMatMult_MPIAIJ_MPIAIJ,
2596                                        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
2597                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
2598                                        0,
2599                                 /*134*/0,
2600                                        0,
2601                                        MatRARt_MPIAIJ_MPIAIJ,
2602                                        0,
2603                                        0,
2604                                 /*139*/MatSetBlockSizes_MPIAIJ,
2605                                        0,
2606                                        0,
2607                                        MatFDColoringSetUp_MPIXAIJ,
2608                                        MatFindOffBlockDiagonalEntries_MPIAIJ,
2609                                 /*144*/MatCreateMPIMatConcatenateSeqMat_MPIAIJ
2610 };
2611 
2612 /* ----------------------------------------------------------------------------------------*/
2613 
2614 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
2615 {
2616   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2617   PetscErrorCode ierr;
2618 
2619   PetscFunctionBegin;
2620   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
2621   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
2622   PetscFunctionReturn(0);
2623 }
2624 
2625 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
2626 {
2627   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2628   PetscErrorCode ierr;
2629 
2630   PetscFunctionBegin;
2631   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
2632   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
2633   PetscFunctionReturn(0);
2634 }
2635 
2636 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
2637 {
2638   Mat_MPIAIJ     *b;
2639   PetscErrorCode ierr;
2640 
2641   PetscFunctionBegin;
2642   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
2643   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
2644   b = (Mat_MPIAIJ*)B->data;
2645 
2646 #if defined(PETSC_USE_CTABLE)
2647   ierr = PetscTableDestroy(&b->colmap);CHKERRQ(ierr);
2648 #else
2649   ierr = PetscFree(b->colmap);CHKERRQ(ierr);
2650 #endif
2651   ierr = PetscFree(b->garray);CHKERRQ(ierr);
2652   ierr = VecDestroy(&b->lvec);CHKERRQ(ierr);
2653   ierr = VecScatterDestroy(&b->Mvctx);CHKERRQ(ierr);
2654 
2655   /* Because the B will have been resized we simply destroy it and create a new one each time */
2656   ierr = MatDestroy(&b->B);CHKERRQ(ierr);
2657   ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
2658   ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
2659   ierr = MatSetBlockSizesFromMats(b->B,B,B);CHKERRQ(ierr);
2660   ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
2661   ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->B);CHKERRQ(ierr);
2662 
2663   if (!B->preallocated) {
2664     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
2665     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
2666     ierr = MatSetBlockSizesFromMats(b->A,B,B);CHKERRQ(ierr);
2667     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
2668     ierr = PetscLogObjectParent((PetscObject)B,(PetscObject)b->A);CHKERRQ(ierr);
2669   }
2670 
2671   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
2672   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
2673   B->preallocated  = PETSC_TRUE;
2674   B->was_assembled = PETSC_FALSE;
2675   B->assembled     = PETSC_FALSE;;
2676   PetscFunctionReturn(0);
2677 }
2678 
2679 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
2680 {
2681   Mat            mat;
2682   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
2683   PetscErrorCode ierr;
2684 
2685   PetscFunctionBegin;
2686   *newmat = 0;
2687   ierr    = MatCreate(PetscObjectComm((PetscObject)matin),&mat);CHKERRQ(ierr);
2688   ierr    = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
2689   ierr    = MatSetBlockSizesFromMats(mat,matin,matin);CHKERRQ(ierr);
2690   ierr    = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
2691   ierr    = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
2692   a       = (Mat_MPIAIJ*)mat->data;
2693 
2694   mat->factortype   = matin->factortype;
2695   mat->assembled    = PETSC_TRUE;
2696   mat->insertmode   = NOT_SET_VALUES;
2697   mat->preallocated = PETSC_TRUE;
2698 
2699   a->size         = oldmat->size;
2700   a->rank         = oldmat->rank;
2701   a->donotstash   = oldmat->donotstash;
2702   a->roworiented  = oldmat->roworiented;
2703   a->rowindices   = 0;
2704   a->rowvalues    = 0;
2705   a->getrowactive = PETSC_FALSE;
2706 
2707   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
2708   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
2709 
2710   if (oldmat->colmap) {
2711 #if defined(PETSC_USE_CTABLE)
2712     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
2713 #else
2714     ierr = PetscMalloc1(mat->cmap->N,&a->colmap);CHKERRQ(ierr);
2715     ierr = PetscLogObjectMemory((PetscObject)mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2716     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2717 #endif
2718   } else a->colmap = 0;
2719   if (oldmat->garray) {
2720     PetscInt len;
2721     len  = oldmat->B->cmap->n;
2722     ierr = PetscMalloc1(len+1,&a->garray);CHKERRQ(ierr);
2723     ierr = PetscLogObjectMemory((PetscObject)mat,len*sizeof(PetscInt));CHKERRQ(ierr);
2724     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
2725   } else a->garray = 0;
2726 
2727   ierr    = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
2728   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->lvec);CHKERRQ(ierr);
2729   ierr    = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
2730   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->Mvctx);CHKERRQ(ierr);
2731   ierr    = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
2732   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->A);CHKERRQ(ierr);
2733   ierr    = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
2734   ierr    = PetscLogObjectParent((PetscObject)mat,(PetscObject)a->B);CHKERRQ(ierr);
2735   ierr    = PetscFunctionListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
2736   *newmat = mat;
2737   PetscFunctionReturn(0);
2738 }
2739 
2740 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
2741 {
2742   PetscScalar    *vals,*svals;
2743   MPI_Comm       comm;
2744   PetscErrorCode ierr;
2745   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
2746   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0;
2747   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
2748   PetscInt       *ourlens = NULL,*procsnz = NULL,*offlens = NULL,jj,*mycols,*smycols;
2749   PetscInt       cend,cstart,n,*rowners;
2750   int            fd;
2751   PetscInt       bs = newMat->rmap->bs;
2752 
2753   PetscFunctionBegin;
2754   /* force binary viewer to load .info file if it has not yet done so */
2755   ierr = PetscViewerSetUp(viewer);CHKERRQ(ierr);
2756   ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
2757   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2758   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2759   ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
2760   if (!rank) {
2761     ierr = PetscBinaryRead(fd,(char*)header,4,PETSC_INT);CHKERRQ(ierr);
2762     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
2763     if (header[3] < 0) SETERRQ(PetscObjectComm((PetscObject)newMat),PETSC_ERR_FILE_UNEXPECTED,"Matrix stored in special format on disk,cannot load as MATMPIAIJ");
2764   }
2765 
2766   ierr = PetscOptionsBegin(comm,NULL,"Options for loading MATMPIAIJ matrix","Mat");CHKERRQ(ierr);
2767   ierr = PetscOptionsInt("-matload_block_size","Set the blocksize used to store the matrix","MatLoad",bs,&bs,NULL);CHKERRQ(ierr);
2768   ierr = PetscOptionsEnd();CHKERRQ(ierr);
2769   if (bs < 0) bs = 1;
2770 
2771   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
2772   M    = header[1]; N = header[2];
2773 
2774   /* If global sizes are set, check if they are consistent with that given in the file */
2775   if (newMat->rmap->N >= 0 && newMat->rmap->N != M) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"Inconsistent # of rows:Matrix in file has (%D) and input matrix has (%D)",newMat->rmap->N,M);
2776   if (newMat->cmap->N >=0 && newMat->cmap->N != N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"Inconsistent # of cols:Matrix in file has (%D) and input matrix has (%D)",newMat->cmap->N,N);
2777 
2778   /* determine ownership of all (block) rows */
2779   if (M%bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows (%d) and block size (%d)",M,bs);
2780   if (newMat->rmap->n < 0) m = bs*((M/bs)/size + (((M/bs) % size) > rank));    /* PETSC_DECIDE */
2781   else m = newMat->rmap->n; /* Set by user */
2782 
2783   ierr = PetscMalloc1(size+1,&rowners);CHKERRQ(ierr);
2784   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
2785 
2786   /* First process needs enough room for process with most rows */
2787   if (!rank) {
2788     mmax = rowners[1];
2789     for (i=2; i<=size; i++) {
2790       mmax = PetscMax(mmax, rowners[i]);
2791     }
2792   } else mmax = -1;             /* unused, but compilers complain */
2793 
2794   rowners[0] = 0;
2795   for (i=2; i<=size; i++) {
2796     rowners[i] += rowners[i-1];
2797   }
2798   rstart = rowners[rank];
2799   rend   = rowners[rank+1];
2800 
2801   /* distribute row lengths to all processors */
2802   ierr = PetscMalloc2(m,&ourlens,m,&offlens);CHKERRQ(ierr);
2803   if (!rank) {
2804     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
2805     ierr = PetscMalloc1(mmax,&rowlengths);CHKERRQ(ierr);
2806     ierr = PetscCalloc1(size,&procsnz);CHKERRQ(ierr);
2807     for (j=0; j<m; j++) {
2808       procsnz[0] += ourlens[j];
2809     }
2810     for (i=1; i<size; i++) {
2811       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
2812       /* calculate the number of nonzeros on each processor */
2813       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
2814         procsnz[i] += rowlengths[j];
2815       }
2816       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2817     }
2818     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
2819   } else {
2820     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
2821   }
2822 
2823   if (!rank) {
2824     /* determine max buffer needed and allocate it */
2825     maxnz = 0;
2826     for (i=0; i<size; i++) {
2827       maxnz = PetscMax(maxnz,procsnz[i]);
2828     }
2829     ierr = PetscMalloc1(maxnz,&cols);CHKERRQ(ierr);
2830 
2831     /* read in my part of the matrix column indices  */
2832     nz   = procsnz[0];
2833     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
2834     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
2835 
2836     /* read in every one elses and ship off */
2837     for (i=1; i<size; i++) {
2838       nz   = procsnz[i];
2839       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
2840       ierr = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2841     }
2842     ierr = PetscFree(cols);CHKERRQ(ierr);
2843   } else {
2844     /* determine buffer space needed for message */
2845     nz = 0;
2846     for (i=0; i<m; i++) {
2847       nz += ourlens[i];
2848     }
2849     ierr = PetscMalloc1(nz,&mycols);CHKERRQ(ierr);
2850 
2851     /* receive message of column indices*/
2852     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
2853   }
2854 
2855   /* determine column ownership if matrix is not square */
2856   if (N != M) {
2857     if (newMat->cmap->n < 0) n = N/size + ((N % size) > rank);
2858     else n = newMat->cmap->n;
2859     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
2860     cstart = cend - n;
2861   } else {
2862     cstart = rstart;
2863     cend   = rend;
2864     n      = cend - cstart;
2865   }
2866 
2867   /* loop over local rows, determining number of off diagonal entries */
2868   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
2869   jj   = 0;
2870   for (i=0; i<m; i++) {
2871     for (j=0; j<ourlens[i]; j++) {
2872       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
2873       jj++;
2874     }
2875   }
2876 
2877   for (i=0; i<m; i++) {
2878     ourlens[i] -= offlens[i];
2879   }
2880   ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
2881 
2882   if (bs > 1) {ierr = MatSetBlockSize(newMat,bs);CHKERRQ(ierr);}
2883 
2884   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
2885 
2886   for (i=0; i<m; i++) {
2887     ourlens[i] += offlens[i];
2888   }
2889 
2890   if (!rank) {
2891     ierr = PetscMalloc1(maxnz+1,&vals);CHKERRQ(ierr);
2892 
2893     /* read in my part of the matrix numerical values  */
2894     nz   = procsnz[0];
2895     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2896 
2897     /* insert into matrix */
2898     jj      = rstart;
2899     smycols = mycols;
2900     svals   = vals;
2901     for (i=0; i<m; i++) {
2902       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2903       smycols += ourlens[i];
2904       svals   += ourlens[i];
2905       jj++;
2906     }
2907 
2908     /* read in other processors and ship out */
2909     for (i=1; i<size; i++) {
2910       nz   = procsnz[i];
2911       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2912       ierr = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
2913     }
2914     ierr = PetscFree(procsnz);CHKERRQ(ierr);
2915   } else {
2916     /* receive numeric values */
2917     ierr = PetscMalloc1(nz+1,&vals);CHKERRQ(ierr);
2918 
2919     /* receive message of values*/
2920     ierr = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
2921 
2922     /* insert into matrix */
2923     jj      = rstart;
2924     smycols = mycols;
2925     svals   = vals;
2926     for (i=0; i<m; i++) {
2927       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2928       smycols += ourlens[i];
2929       svals   += ourlens[i];
2930       jj++;
2931     }
2932   }
2933   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
2934   ierr = PetscFree(vals);CHKERRQ(ierr);
2935   ierr = PetscFree(mycols);CHKERRQ(ierr);
2936   ierr = PetscFree(rowners);CHKERRQ(ierr);
2937   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2938   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2939   PetscFunctionReturn(0);
2940 }
2941 
2942 /* Not scalable because of ISAllGather() unless getting all columns. */
2943 PetscErrorCode ISGetSeqIS_Private(Mat mat,IS iscol,IS *isseq)
2944 {
2945   PetscErrorCode ierr;
2946   IS             iscol_local;
2947   PetscBool      isstride;
2948   PetscMPIInt    lisstride=0,gisstride;
2949 
2950   PetscFunctionBegin;
2951   /* check if we are grabbing all columns*/
2952   ierr = PetscObjectTypeCompare((PetscObject)iscol,ISSTRIDE,&isstride);CHKERRQ(ierr);
2953 
2954   if (isstride) {
2955     PetscInt  start,len,mstart,mlen;
2956     ierr = ISStrideGetInfo(iscol,&start,NULL);CHKERRQ(ierr);
2957     ierr = ISGetLocalSize(iscol,&len);CHKERRQ(ierr);
2958     ierr = MatGetOwnershipRangeColumn(mat,&mstart,&mlen);CHKERRQ(ierr);
2959     if (mstart == start && mlen-mstart == len) lisstride = 1;
2960   }
2961 
2962   ierr = MPIU_Allreduce(&lisstride,&gisstride,1,MPI_INT,MPI_MIN,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
2963   if (gisstride) {
2964     PetscInt N;
2965     ierr = MatGetSize(mat,NULL,&N);CHKERRQ(ierr);
2966     ierr = ISCreateStride(PetscObjectComm((PetscObject)mat),N,0,1,&iscol_local);CHKERRQ(ierr);
2967     ierr = ISSetIdentity(iscol_local);CHKERRQ(ierr);
2968     ierr = PetscInfo(mat,"Optimizing for obtaining all columns of the matrix; skipping ISAllGather()\n");CHKERRQ(ierr);
2969   } else {
2970     PetscInt cbs;
2971     ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
2972     ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
2973     ierr = ISSetBlockSize(iscol_local,cbs);CHKERRQ(ierr);
2974   }
2975 
2976   *isseq = iscol_local;
2977   PetscFunctionReturn(0);
2978 }
2979 
2980 /*
2981  Used by MatCreateSubMatrix_MPIAIJ_SameRowColDist() to avoid ISAllGather() and global size of iscol_local
2982  (see MatCreateSubMatrix_MPIAIJ_nonscalable)
2983 
2984  Input Parameters:
2985    mat - matrix
2986    isrow - parallel row index set; its local indices are a subset of local columns of mat,
2987            i.e., mat->rstart <= isrow[i] < mat->rend
2988    iscol - parallel column index set; its local indices are a subset of local columns of mat,
2989            i.e., mat->cstart <= iscol[i] < mat->cend
2990  Output Parameter:
2991    isrow_d,iscol_d - sequential row and column index sets for retrieving mat->A
2992    iscol_o - sequential column index set for retrieving mat->B
2993    garray - column map; garray[i] indicates global location of iscol_o[i] in iscol
2994  */
2995 PetscErrorCode ISGetSeqIS_SameColDist_Private(Mat mat,IS isrow,IS iscol,IS *isrow_d,IS *iscol_d,IS *iscol_o,const PetscInt *garray[])
2996 {
2997   PetscErrorCode ierr;
2998   Vec            x,cmap;
2999   const PetscInt *is_idx;
3000   PetscScalar    *xarray,*cmaparray;
3001   PetscInt       ncols,isstart,*idx,m,rstart,*cmap1,count;
3002   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)mat->data;
3003   Mat            B=a->B;
3004   Vec            lvec=a->lvec,lcmap;
3005   PetscInt       i,cstart,cend,Bn=B->cmap->N;
3006   MPI_Comm       comm;
3007 
3008   PetscFunctionBegin;
3009   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3010   ierr = ISGetLocalSize(iscol,&ncols);CHKERRQ(ierr);
3011 
3012   /* (1) iscol is a sub-column vector of mat, pad it with '-1.' to form a full vector x */
3013   ierr = MatCreateVecs(mat,&x,NULL);CHKERRQ(ierr);
3014   ierr = VecDuplicate(x,&cmap);CHKERRQ(ierr);
3015   ierr = VecSet(x,-1.0);CHKERRQ(ierr);
3016 
3017   /* Get start indices */
3018   ierr = MPI_Scan(&ncols,&isstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3019   isstart -= ncols;
3020   ierr = MatGetOwnershipRangeColumn(mat,&cstart,&cend);CHKERRQ(ierr);
3021 
3022   ierr = ISGetIndices(iscol,&is_idx);CHKERRQ(ierr);
3023   ierr = VecGetArray(x,&xarray);CHKERRQ(ierr);
3024   ierr = VecGetArray(cmap,&cmaparray);CHKERRQ(ierr);
3025   ierr = PetscMalloc1(ncols,&idx);CHKERRQ(ierr);
3026   for (i=0; i<ncols; i++) {
3027     xarray[is_idx[i]-cstart]    = (PetscScalar)is_idx[i];
3028     cmaparray[is_idx[i]-cstart] = i + isstart;      /* global index of iscol[i] */
3029     idx[i]                      = is_idx[i]-cstart; /* local index of iscol[i]  */
3030   }
3031   ierr = VecRestoreArray(x,&xarray);CHKERRQ(ierr);
3032   ierr = VecRestoreArray(cmap,&cmaparray);CHKERRQ(ierr);
3033   ierr = ISRestoreIndices(iscol,&is_idx);CHKERRQ(ierr);
3034 
3035   /* Get iscol_d */
3036   ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,iscol_d);CHKERRQ(ierr);
3037   ierr = ISGetBlockSize(iscol,&i);CHKERRQ(ierr);
3038   ierr = ISSetBlockSize(*iscol_d,i);CHKERRQ(ierr);
3039 
3040   /* Get isrow_d */
3041   ierr = ISGetLocalSize(isrow,&m);CHKERRQ(ierr);
3042   rstart = mat->rmap->rstart;
3043   ierr = PetscMalloc1(m,&idx);CHKERRQ(ierr);
3044   ierr = ISGetIndices(isrow,&is_idx);CHKERRQ(ierr);
3045   for (i=0; i<m; i++) idx[i] = is_idx[i]-rstart;
3046   ierr = ISRestoreIndices(isrow,&is_idx);CHKERRQ(ierr);
3047 
3048   ierr = ISCreateGeneral(PETSC_COMM_SELF,m,idx,PETSC_OWN_POINTER,isrow_d);CHKERRQ(ierr);
3049   ierr = ISGetBlockSize(isrow,&i);CHKERRQ(ierr);
3050   ierr = ISSetBlockSize(*isrow_d,i);CHKERRQ(ierr);
3051 
3052   /* (2) Scatter x and cmap using aij->Mvctx to get their off-process portions (see MatMult_MPIAIJ) */
3053   ierr = VecScatterBegin(a->Mvctx,x,lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
3054 
3055   ierr = VecDuplicate(lvec,&lcmap);CHKERRQ(ierr);
3056 
3057   ierr = VecScatterEnd(a->Mvctx,x,lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
3058   ierr = VecScatterBegin(a->Mvctx,cmap,lcmap,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
3059   ierr = VecScatterEnd(a->Mvctx,cmap,lcmap,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
3060 
3061   /* (3) create sequential iscol_o (a subset of iscol) and isgarray */
3062   /* off-process column indices */
3063   count = 0;
3064   ierr = PetscMalloc1(Bn,&idx);CHKERRQ(ierr);
3065   ierr = PetscMalloc1(Bn,&cmap1);CHKERRQ(ierr);
3066 
3067   ierr = VecGetArray(lvec,&xarray);CHKERRQ(ierr);
3068   ierr = VecGetArray(lcmap,&cmaparray);CHKERRQ(ierr);
3069   for (i=0; i<Bn; i++) {
3070     if (PetscRealPart(xarray[i]) > -1.0) {
3071       idx[count]     = i;                   /* local column index in off-diagonal part B */
3072       cmap1[count++] = (PetscInt)PetscRealPart(cmaparray[i]);  /* column index in submat */
3073     }
3074   }
3075   ierr = VecRestoreArray(lvec,&xarray);CHKERRQ(ierr);
3076   ierr = VecRestoreArray(lcmap,&cmaparray);CHKERRQ(ierr);
3077 
3078   ierr = ISCreateGeneral(PETSC_COMM_SELF,count,idx,PETSC_COPY_VALUES,iscol_o);CHKERRQ(ierr);
3079   /* cannot ensure iscol_o has same blocksize as iscol! */
3080 
3081   ierr = PetscFree(idx);CHKERRQ(ierr);
3082 
3083   *garray = cmap1;
3084 
3085   ierr = VecDestroy(&x);CHKERRQ(ierr);
3086   ierr = VecDestroy(&cmap);CHKERRQ(ierr);
3087   ierr = VecDestroy(&lcmap);CHKERRQ(ierr);
3088   PetscFunctionReturn(0);
3089 }
3090 
3091 /* isrow and iscol have same processor distribution as mat, output *submat is a submatrix of local mat */
3092 PetscErrorCode MatCreateSubMatrix_MPIAIJ_SameRowColDist(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *submat)
3093 {
3094   PetscErrorCode ierr;
3095   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)mat->data,*asub;
3096   Mat            M = NULL;
3097   MPI_Comm       comm;
3098   IS             iscol_d,isrow_d,iscol_o;
3099   Mat            Asub = NULL,Bsub = NULL;
3100   PetscInt       n;
3101 
3102   PetscFunctionBegin;
3103   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3104 
3105   if (call == MAT_REUSE_MATRIX) {
3106     /* Retrieve isrow_d, iscol_d and iscol_o from submat */
3107     ierr = PetscObjectQuery((PetscObject)*submat,"isrow_d",(PetscObject*)&isrow_d);CHKERRQ(ierr);
3108     if (!isrow_d) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"isrow_d passed in was not used before, cannot reuse");
3109 
3110     ierr = PetscObjectQuery((PetscObject)*submat,"iscol_d",(PetscObject*)&iscol_d);CHKERRQ(ierr);
3111     if (!iscol_d) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"iscol_d passed in was not used before, cannot reuse");
3112 
3113     ierr = PetscObjectQuery((PetscObject)*submat,"iscol_o",(PetscObject*)&iscol_o);CHKERRQ(ierr);
3114     if (!iscol_o) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"iscol_o passed in was not used before, cannot reuse");
3115 
3116     /* Update diagonal and off-diagonal portions of submat */
3117     asub = (Mat_MPIAIJ*)(*submat)->data;
3118     ierr = MatCreateSubMatrix_SeqAIJ(a->A,isrow_d,iscol_d,PETSC_DECIDE,MAT_REUSE_MATRIX,&asub->A);CHKERRQ(ierr);
3119     ierr = ISGetLocalSize(iscol_o,&n);CHKERRQ(ierr);
3120     if (n) {
3121       ierr = MatCreateSubMatrix_SeqAIJ(a->B,isrow_d,iscol_o,PETSC_DECIDE,MAT_REUSE_MATRIX,&asub->B);CHKERRQ(ierr);
3122     }
3123     ierr = MatAssemblyBegin(*submat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3124     ierr = MatAssemblyEnd(*submat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3125 
3126   } else { /* call == MAT_INITIAL_MATRIX) */
3127     const PetscInt *garray;
3128     PetscInt        BsubN;
3129 
3130     /* Create isrow_d, iscol_d, iscol_o and isgarray (replace isgarray with array?) */
3131     ierr = ISGetSeqIS_SameColDist_Private(mat,isrow,iscol,&isrow_d,&iscol_d,&iscol_o,&garray);CHKERRQ(ierr);
3132 
3133     /* Create local submatrices Asub and Bsub */
3134     ierr = MatCreateSubMatrix_SeqAIJ(a->A,isrow_d,iscol_d,PETSC_DECIDE,MAT_INITIAL_MATRIX,&Asub);CHKERRQ(ierr);
3135     ierr = MatCreateSubMatrix_SeqAIJ(a->B,isrow_d,iscol_o,PETSC_DECIDE,MAT_INITIAL_MATRIX,&Bsub);CHKERRQ(ierr);
3136 
3137     /* Create submatrix M */
3138     ierr = MatCreateMPIAIJWithSeqAIJ(comm,Asub,Bsub,garray,&M);CHKERRQ(ierr);
3139 
3140     /* If Bsub has empty columns, compress iscol_o such that it will retrieve condensed Bsub from a->B during reuse */
3141     asub = (Mat_MPIAIJ*)M->data;
3142 
3143     ierr = ISGetLocalSize(iscol_o,&BsubN);CHKERRQ(ierr);
3144     n = asub->B->cmap->N;
3145     if (BsubN > n) {
3146       /* This case can be tested using ~petsc/src/tao/bound/examples/tutorials/runplate2_3 */
3147       const PetscInt *idx;
3148       PetscInt       i,j,*idx_new,*subgarray = asub->garray;
3149       ierr = PetscInfo2(M,"submatrix Bn %D != BsubN %D, update iscol_o\n",n,BsubN);CHKERRQ(ierr);
3150 
3151       ierr = PetscMalloc1(n,&idx_new);CHKERRQ(ierr);
3152       j = 0;
3153       ierr = ISGetIndices(iscol_o,&idx);CHKERRQ(ierr);
3154       for (i=0; i<n; i++) {
3155         if (j >= BsubN) break;
3156         while (subgarray[i] > garray[j]) j++;
3157 
3158         if (subgarray[i] == garray[j]) {
3159           idx_new[i] = idx[j++];
3160         } else SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"subgarray[%D]=%D cannot < garray[%D]=%D",i,subgarray[i],j,garray[j]);
3161       }
3162       ierr = ISRestoreIndices(iscol_o,&idx);CHKERRQ(ierr);
3163 
3164       ierr = ISDestroy(&iscol_o);CHKERRQ(ierr);
3165       ierr = ISCreateGeneral(PETSC_COMM_SELF,n,idx_new,PETSC_OWN_POINTER,&iscol_o);CHKERRQ(ierr);
3166 
3167     } else if (BsubN < n) {
3168       SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Columns of Bsub cannot be smaller than B's",BsubN,asub->B->cmap->N);
3169     }
3170 
3171     ierr = PetscFree(garray);CHKERRQ(ierr);
3172     *submat = M;
3173 
3174     /* Save isrow_d, iscol_d and iscol_o used in processor for next request */
3175     ierr = PetscObjectCompose((PetscObject)M,"isrow_d",(PetscObject)isrow_d);CHKERRQ(ierr);
3176     ierr = ISDestroy(&isrow_d);CHKERRQ(ierr);
3177 
3178     ierr = PetscObjectCompose((PetscObject)M,"iscol_d",(PetscObject)iscol_d);CHKERRQ(ierr);
3179     ierr = ISDestroy(&iscol_d);CHKERRQ(ierr);
3180 
3181     ierr = PetscObjectCompose((PetscObject)M,"iscol_o",(PetscObject)iscol_o);CHKERRQ(ierr);
3182     ierr = ISDestroy(&iscol_o);CHKERRQ(ierr);
3183   }
3184   PetscFunctionReturn(0);
3185 }
3186 
3187 PetscErrorCode MatCreateSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3188 {
3189   PetscErrorCode ierr;
3190   IS             iscol_local,isrow_d;
3191   PetscInt       csize;
3192   PetscInt       n,i,j,start,end;
3193   PetscBool      sameRowDist=PETSC_FALSE,sameDist[2],tsameDist[2];
3194   MPI_Comm       comm;
3195 
3196   PetscFunctionBegin;
3197   /* If isrow has same processor distribution as mat,
3198      call MatCreateSubMatrix_MPIAIJ_SameRowDist() to avoid using a hash table with global size of iscol */
3199   if (call == MAT_REUSE_MATRIX) {
3200     ierr = PetscObjectQuery((PetscObject)*newmat,"isrow_d",(PetscObject*)&isrow_d);CHKERRQ(ierr);
3201     if (isrow_d) {
3202       sameRowDist  = PETSC_TRUE;
3203       tsameDist[1] = PETSC_TRUE; /* sameColDist */
3204     } else {
3205       ierr = PetscObjectQuery((PetscObject)*newmat,"SubIScol",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3206       if (iscol_local) {
3207         sameRowDist  = PETSC_TRUE;
3208         tsameDist[1] = PETSC_FALSE; /* !sameColDist */
3209       }
3210     }
3211   } else {
3212     /* Check if isrow has same processor distribution as mat */
3213     sameDist[0] = PETSC_FALSE;
3214     ierr = ISGetLocalSize(isrow,&n);CHKERRQ(ierr);
3215     if (!n) {
3216       sameDist[0] = PETSC_TRUE;
3217     } else {
3218       ierr = ISGetMinMax(isrow,&i,&j);CHKERRQ(ierr);
3219       ierr = MatGetOwnershipRange(mat,&start,&end);CHKERRQ(ierr);
3220       if (i >= start && j < end) {
3221         sameDist[0] = PETSC_TRUE;
3222       }
3223     }
3224 
3225     /* Check if iscol has same processor distribution as mat */
3226     sameDist[1] = PETSC_FALSE;
3227     ierr = ISGetLocalSize(iscol,&n);CHKERRQ(ierr);
3228     if (!n) {
3229       sameDist[1] = PETSC_TRUE;
3230     } else {
3231       ierr = ISGetMinMax(iscol,&i,&j);CHKERRQ(ierr);
3232       ierr = MatGetOwnershipRangeColumn(mat,&start,&end);CHKERRQ(ierr);
3233       if (i >= start && j < end) sameDist[1] = PETSC_TRUE;
3234     }
3235 
3236     ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3237     ierr = MPIU_Allreduce(&sameDist,&tsameDist,2,MPIU_BOOL,MPI_LAND,comm);CHKERRQ(ierr);
3238     sameRowDist = tsameDist[0];
3239   }
3240 
3241   if (sameRowDist) {
3242     if (tsameDist[1]) { /* sameRowDist & sameColDist */
3243       /* isrow and iscol have same processor distribution as mat */
3244       ierr = MatCreateSubMatrix_MPIAIJ_SameRowColDist(mat,isrow,iscol,call,newmat);CHKERRQ(ierr);
3245     } else { /* sameRowDist */
3246       /* isrow has same processor distribution as mat */
3247       ierr = MatCreateSubMatrix_MPIAIJ_SameRowDist(mat,isrow,iscol,call,newmat);CHKERRQ(ierr);
3248     }
3249     PetscFunctionReturn(0);
3250   }
3251 
3252   /* General case: iscol -> iscol_local which has global size of iscol */
3253   if (call == MAT_REUSE_MATRIX) {
3254     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3255     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3256   } else {
3257     ierr = ISGetSeqIS_Private(mat,iscol,&iscol_local);CHKERRQ(ierr);
3258   }
3259 
3260   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3261   ierr = MatCreateSubMatrix_MPIAIJ_nonscalable(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3262 
3263   if (call == MAT_INITIAL_MATRIX) {
3264     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3265     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3266   }
3267   PetscFunctionReturn(0);
3268 }
3269 
3270 /*@C
3271      MatCreateMPIAIJWithSeqAIJ - creates a MPIAIJ matrix using SeqAIJ matrices that contain the "diagonal"
3272          and "off-diagonal" part of the matrix in CSR format.
3273 
3274    Collective on MPI_Comm
3275 
3276    Input Parameters:
3277 +  comm - MPI communicator
3278 .  A - "diagonal" portion of matrix
3279 .  B - "off-diagonal" portion of matrix, may have empty columns, will be destroyed by this routine
3280 -  garray - global index of B columns
3281 
3282    Output Parameter:
3283 .   mat - the matrix, with input A as its local diagonal matrix
3284    Level: advanced
3285 
3286    Notes:
3287        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix.
3288        A becomes part of output mat, B is destroyed by this routine. The user cannot use A and B anymore.
3289 
3290 .seealso: MatCreateMPIAIJWithSplitArrays()
3291 @*/
3292 PetscErrorCode MatCreateMPIAIJWithSeqAIJ(MPI_Comm comm,Mat A,Mat B,const PetscInt garray[],Mat *mat)
3293 {
3294   PetscErrorCode ierr;
3295   Mat_MPIAIJ     *maij;
3296   Mat_SeqAIJ     *b=(Mat_SeqAIJ*)B->data,*bnew;
3297   PetscInt       *oi=b->i,*oj=b->j,i,nz,col;
3298   PetscScalar    *oa=b->a;
3299   Mat            Bnew;
3300   PetscInt       m,n,N;
3301 
3302   PetscFunctionBegin;
3303   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
3304   ierr = MatGetSize(A,&m,&n);CHKERRQ(ierr);
3305   if (m != B->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Am %D != Bm %D",m,B->rmap->N);
3306   if (A->rmap->bs != B->rmap->bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"A row bs %D != B row bs %D",A->rmap->bs,B->rmap->bs);
3307   /* remove check below; When B is created using iscol_o from ISGetSeqIS_SameColDist_Private(), its bs may not be same as A */
3308   /* if (A->cmap->bs != B->cmap->bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"A column bs %D != B column bs %D",A->cmap->bs,B->cmap->bs); */
3309 
3310   /* Get global columns of mat */
3311   ierr = MPIU_Allreduce(&n,&N,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3312 
3313   ierr = MatSetSizes(*mat,m,n,PETSC_DECIDE,N);CHKERRQ(ierr);
3314   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
3315   ierr = MatSetBlockSizes(*mat,A->rmap->bs,A->cmap->bs);CHKERRQ(ierr);
3316   maij = (Mat_MPIAIJ*)(*mat)->data;
3317 
3318   (*mat)->preallocated = PETSC_TRUE;
3319 
3320   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
3321   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
3322 
3323   /* Set A as diagonal portion of *mat */
3324   maij->A = A;
3325 
3326   nz = oi[m];
3327   for (i=0; i<nz; i++) {
3328     col   = oj[i];
3329     oj[i] = garray[col];
3330   }
3331 
3332    /* Set Bnew as off-diagonal portion of *mat */
3333   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,N,oi,oj,oa,&Bnew);CHKERRQ(ierr);
3334   bnew        = (Mat_SeqAIJ*)Bnew->data;
3335   bnew->maxnz = b->maxnz; /* allocated nonzeros of B */
3336   maij->B     = Bnew;
3337 
3338   if (B->rmap->N != Bnew->rmap->N) SETERRQ2(PETSC_COMM_SELF,0,"BN %d != BnewN %d",B->rmap->N,Bnew->rmap->N);
3339 
3340   b->singlemalloc = PETSC_FALSE; /* B arrays are shared by Bnew */
3341   b->free_a       = PETSC_FALSE;
3342   b->free_ij      = PETSC_FALSE;
3343   ierr = MatDestroy(&B);CHKERRQ(ierr);
3344 
3345   bnew->singlemalloc = PETSC_TRUE; /* arrays will be freed by MatDestroy(&Bnew) */
3346   bnew->free_a       = PETSC_TRUE;
3347   bnew->free_ij      = PETSC_TRUE;
3348 
3349   /* condense columns of maij->B */
3350   ierr = MatSetOption(*mat,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
3351   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3352   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3353   ierr = MatSetOption(*mat,MAT_NO_OFF_PROC_ENTRIES,PETSC_FALSE);CHKERRQ(ierr);
3354   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3355   PetscFunctionReturn(0);
3356 }
3357 
3358 extern PetscErrorCode MatCreateSubMatrices_MPIAIJ_SingleIS_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool,Mat*);
3359 
3360 PetscErrorCode MatCreateSubMatrix_MPIAIJ_SameRowDist(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3361 {
3362   PetscErrorCode ierr;
3363   PetscInt       i,m,n,rstart,row,rend,nz,j,bs,cbs;
3364   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal;
3365   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)mat->data;
3366   Mat            M,Msub,B=a->B;
3367   MatScalar      *aa;
3368   Mat_SeqAIJ     *aij;
3369   PetscInt       *garray = a->garray,*colsub,Ncols;
3370   PetscInt       count,Bn=B->cmap->N,cstart=mat->cmap->rstart,cend=mat->cmap->rend;
3371   IS             iscol_sub,iscmap;
3372   const PetscInt *is_idx,*cmap;
3373   PetscBool      allcolumns=PETSC_FALSE;
3374   IS             iscol_local=NULL;
3375   MPI_Comm       comm;
3376 
3377   PetscFunctionBegin;
3378   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3379 
3380   if (call == MAT_REUSE_MATRIX) {
3381     ierr = PetscObjectQuery((PetscObject)*newmat,"SubIScol",(PetscObject*)&iscol_sub);CHKERRQ(ierr);
3382     if (!iscol_sub) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SubIScol passed in was not used before, cannot reuse");
3383     ierr = ISGetLocalSize(iscol_sub,&count);CHKERRQ(ierr);
3384 
3385     ierr = PetscObjectQuery((PetscObject)*newmat,"Subcmap",(PetscObject*)&iscmap);CHKERRQ(ierr);
3386     if (!iscmap) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Subcmap passed in was not used before, cannot reuse");
3387 
3388     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Msub);CHKERRQ(ierr);
3389     if (!Msub) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3390 
3391     ierr = MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat,1,&isrow,&iscol_sub,MAT_REUSE_MATRIX,PETSC_FALSE,&Msub);CHKERRQ(ierr);
3392 
3393   } else { /* call == MAT_INITIAL_MATRIX) */
3394     PetscBool flg;
3395 
3396     ierr = ISGetLocalSize(iscol,&n);CHKERRQ(ierr);
3397     ierr = ISGetSize(iscol,&Ncols);CHKERRQ(ierr);
3398 
3399     /* (1) iscol -> nonscalable iscol_local */
3400     ierr = ISGetSeqIS_Private(mat,iscol,&iscol_local);CHKERRQ(ierr);
3401     ierr = ISGetLocalSize(iscol_local,&n);CHKERRQ(ierr); /* local size of iscol_local = global columns of newmat */
3402     if (n != Ncols) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"n %d != Ncols %d",n,Ncols);
3403 
3404     /* Check for special case: each processor gets entire matrix columns */
3405     ierr = ISIdentity(iscol_local,&flg);CHKERRQ(ierr);
3406     if (flg && n == mat->cmap->N) allcolumns = PETSC_TRUE;
3407     if (allcolumns) {
3408       iscol_sub = iscol_local;
3409       ierr = PetscObjectReference((PetscObject)iscol_local);CHKERRQ(ierr);
3410       ierr = ISCreateStride(PETSC_COMM_SELF,n,0,1,&iscmap);CHKERRQ(ierr);
3411 
3412     } else {
3413       /* (2) iscol_local -> iscol_sub and iscmap */
3414       PetscInt *idx,*cmap1,k;
3415 
3416       /* implementation below requires iscol_local be sorted, it can have duplicate indices */
3417       ierr = ISSorted(iscol_local,&flg);CHKERRQ(ierr);
3418       if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"unsorted iscol_local is not implemented yet");
3419 
3420       ierr = PetscMalloc1(Ncols,&idx);CHKERRQ(ierr);
3421       ierr = PetscMalloc1(Ncols,&cmap1);CHKERRQ(ierr);
3422       ierr = ISGetIndices(iscol_local,&is_idx);CHKERRQ(ierr);
3423       count = 0;
3424       k     = 0;
3425       for (i=0; i<Ncols; i++) {
3426         j = is_idx[i];
3427         if (j >= cstart && j < cend) {
3428           /* diagonal part of mat */
3429           idx[count]     = j;
3430           cmap1[count++] = i; /* column index in submat */
3431         } else if (Bn) {
3432           /* off-diagonal part of mat */
3433           if (j == garray[k]) {
3434             idx[count]     = j;
3435             cmap1[count++] = i;  /* column index in submat */
3436           } else if (j > garray[k]) {
3437             while (j > garray[k] && k < Bn-1) k++;
3438             if (j == garray[k]) {
3439               idx[count]     = j;
3440               cmap1[count++] = i; /* column index in submat */
3441             }
3442           }
3443         }
3444       }
3445       ierr = ISRestoreIndices(iscol_local,&is_idx);CHKERRQ(ierr);
3446 
3447       ierr = ISCreateGeneral(PETSC_COMM_SELF,count,idx,PETSC_OWN_POINTER,&iscol_sub);CHKERRQ(ierr);
3448       ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3449       ierr = ISSetBlockSize(iscol_sub,cbs);CHKERRQ(ierr);
3450 
3451       ierr = ISCreateGeneral(PetscObjectComm((PetscObject)iscol_local),count,cmap1,PETSC_OWN_POINTER,&iscmap);CHKERRQ(ierr);
3452     }
3453 
3454     /* (3) Create sequential Msub */
3455     ierr = MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat,1,&isrow,&iscol_sub,MAT_INITIAL_MATRIX,allcolumns,&Msub);CHKERRQ(ierr);
3456   }
3457 
3458   ierr = ISGetLocalSize(iscol_sub,&count);CHKERRQ(ierr);
3459   aij  = (Mat_SeqAIJ*)(Msub)->data;
3460   ii   = aij->i;
3461   ierr = ISGetIndices(iscmap,&cmap);CHKERRQ(ierr);
3462 
3463   /*
3464       m - number of local rows
3465       Ncols - number of columns (same on all processors)
3466       rstart - first row in new global matrix generated
3467   */
3468   ierr = MatGetSize(Msub,&m,NULL);CHKERRQ(ierr);
3469 
3470   if (call == MAT_INITIAL_MATRIX) {
3471     /* (4) Create parallel newmat */
3472     PetscMPIInt    rank,size;
3473     PetscInt       csize;
3474 
3475     ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3476     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3477 
3478     /*
3479         Determine the number of non-zeros in the diagonal and off-diagonal
3480         portions of the matrix in order to do correct preallocation
3481     */
3482 
3483     /* first get start and end of "diagonal" columns */
3484     ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3485     if (csize == PETSC_DECIDE) {
3486       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3487       if (mglobal == Ncols) { /* square matrix */
3488         nlocal = m;
3489       } else {
3490         nlocal = Ncols/size + ((Ncols % size) > rank);
3491       }
3492     } else {
3493       nlocal = csize;
3494     }
3495     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3496     rstart = rend - nlocal;
3497     if (rank == size - 1 && rend != Ncols) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Local column sizes %D do not add up to total number of columns %D",rend,Ncols);
3498 
3499     /* next, compute all the lengths */
3500     jj    = aij->j;
3501     ierr  = PetscMalloc1(2*m+1,&dlens);CHKERRQ(ierr);
3502     olens = dlens + m;
3503     for (i=0; i<m; i++) {
3504       jend = ii[i+1] - ii[i];
3505       olen = 0;
3506       dlen = 0;
3507       for (j=0; j<jend; j++) {
3508         if (cmap[*jj] < rstart || cmap[*jj] >= rend) olen++;
3509         else dlen++;
3510         jj++;
3511       }
3512       olens[i] = olen;
3513       dlens[i] = dlen;
3514     }
3515 
3516     ierr = ISGetBlockSize(isrow,&bs);CHKERRQ(ierr);
3517     ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3518 
3519     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3520     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,Ncols);CHKERRQ(ierr);
3521     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3522     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3523     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3524     ierr = PetscFree(dlens);CHKERRQ(ierr);
3525 
3526   } else { /* call == MAT_REUSE_MATRIX */
3527     M    = *newmat;
3528     ierr = MatGetLocalSize(M,&i,NULL);CHKERRQ(ierr);
3529     if (i != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3530     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3531     /*
3532          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3533        rather than the slower MatSetValues().
3534     */
3535     M->was_assembled = PETSC_TRUE;
3536     M->assembled     = PETSC_FALSE;
3537   }
3538 
3539   /* (5) Set values of Msub to *newmat */
3540   ierr = PetscMalloc1(count,&colsub);CHKERRQ(ierr);
3541   ierr = MatGetOwnershipRange(M,&rstart,NULL);CHKERRQ(ierr);
3542 
3543   jj   = aij->j;
3544   aa   = aij->a;
3545   for (i=0; i<m; i++) {
3546     row = rstart + i;
3547     nz  = ii[i+1] - ii[i];
3548     for (j=0; j<nz; j++) colsub[j] = cmap[jj[j]];
3549     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,colsub,aa,INSERT_VALUES);CHKERRQ(ierr);
3550     jj += nz; aa += nz;
3551   }
3552   ierr = ISRestoreIndices(iscmap,&cmap);CHKERRQ(ierr);
3553 
3554   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3555   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3556 
3557   ierr = PetscFree(colsub);CHKERRQ(ierr);
3558 
3559   /* save Msub, iscol_sub and iscmap used in processor for next request */
3560   if (call ==  MAT_INITIAL_MATRIX) {
3561     *newmat = M;
3562     ierr = PetscObjectCompose((PetscObject)(*newmat),"SubMatrix",(PetscObject)Msub);CHKERRQ(ierr);
3563     ierr = MatDestroy(&Msub);CHKERRQ(ierr);
3564 
3565     ierr = PetscObjectCompose((PetscObject)(*newmat),"SubIScol",(PetscObject)iscol_sub);CHKERRQ(ierr);
3566     ierr = ISDestroy(&iscol_sub);CHKERRQ(ierr);
3567 
3568     ierr = PetscObjectCompose((PetscObject)(*newmat),"Subcmap",(PetscObject)iscmap);CHKERRQ(ierr);
3569     ierr = ISDestroy(&iscmap);CHKERRQ(ierr);
3570 
3571     if (iscol_local) {
3572       ierr = PetscObjectCompose((PetscObject)(*newmat),"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3573       ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3574     }
3575   }
3576   PetscFunctionReturn(0);
3577 }
3578 
3579 /*
3580     Not great since it makes two copies of the submatrix, first an SeqAIJ
3581   in local and then by concatenating the local matrices the end result.
3582   Writing it directly would be much like MatCreateSubMatrices_MPIAIJ()
3583 
3584   Note: This requires a sequential iscol with all indices.
3585 */
3586 PetscErrorCode MatCreateSubMatrix_MPIAIJ_nonscalable(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3587 {
3588   PetscErrorCode ierr;
3589   PetscMPIInt    rank,size;
3590   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3591   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal;
3592   Mat            M,Mreuse;
3593   MatScalar      *aa,*vwork;
3594   MPI_Comm       comm;
3595   Mat_SeqAIJ     *aij;
3596   PetscBool      colflag,allcolumns=PETSC_FALSE;
3597 
3598   PetscFunctionBegin;
3599   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3600   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3601   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3602 
3603   /* Check for special case: each processor gets entire matrix columns */
3604   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3605   ierr = ISGetLocalSize(iscol,&n);CHKERRQ(ierr);
3606   if (colflag && n == mat->cmap->N) allcolumns = PETSC_TRUE;
3607 
3608   if (call ==  MAT_REUSE_MATRIX) {
3609     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Mreuse);CHKERRQ(ierr);
3610     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3611     ierr = MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,allcolumns,&Mreuse);CHKERRQ(ierr);
3612   } else {
3613     ierr = MatCreateSubMatrices_MPIAIJ_SingleIS_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,allcolumns,&Mreuse);CHKERRQ(ierr);
3614   }
3615 
3616   /*
3617       m - number of local rows
3618       n - number of columns (same on all processors)
3619       rstart - first row in new global matrix generated
3620   */
3621   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3622   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3623   if (call == MAT_INITIAL_MATRIX) {
3624     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3625     ii  = aij->i;
3626     jj  = aij->j;
3627 
3628     /*
3629         Determine the number of non-zeros in the diagonal and off-diagonal
3630         portions of the matrix in order to do correct preallocation
3631     */
3632 
3633     /* first get start and end of "diagonal" columns */
3634     if (csize == PETSC_DECIDE) {
3635       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3636       if (mglobal == n) { /* square matrix */
3637         nlocal = m;
3638       } else {
3639         nlocal = n/size + ((n % size) > rank);
3640       }
3641     } else {
3642       nlocal = csize;
3643     }
3644     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3645     rstart = rend - nlocal;
3646     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);
3647 
3648     /* next, compute all the lengths */
3649     ierr  = PetscMalloc1(2*m+1,&dlens);CHKERRQ(ierr);
3650     olens = dlens + m;
3651     for (i=0; i<m; i++) {
3652       jend = ii[i+1] - ii[i];
3653       olen = 0;
3654       dlen = 0;
3655       for (j=0; j<jend; j++) {
3656         if (*jj < rstart || *jj >= rend) olen++;
3657         else dlen++;
3658         jj++;
3659       }
3660       olens[i] = olen;
3661       dlens[i] = dlen;
3662     }
3663     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3664     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3665     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3666     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3667     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3668     ierr = PetscFree(dlens);CHKERRQ(ierr);
3669   } else {
3670     PetscInt ml,nl;
3671 
3672     M    = *newmat;
3673     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3674     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3675     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3676     /*
3677          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3678        rather than the slower MatSetValues().
3679     */
3680     M->was_assembled = PETSC_TRUE;
3681     M->assembled     = PETSC_FALSE;
3682   }
3683   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3684   aij  = (Mat_SeqAIJ*)(Mreuse)->data;
3685   ii   = aij->i;
3686   jj   = aij->j;
3687   aa   = aij->a;
3688   for (i=0; i<m; i++) {
3689     row   = rstart + i;
3690     nz    = ii[i+1] - ii[i];
3691     cwork = jj;     jj += nz;
3692     vwork = aa;     aa += nz;
3693     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3694   }
3695 
3696   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3697   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3698   *newmat = M;
3699 
3700   /* save submatrix used in processor for next request */
3701   if (call ==  MAT_INITIAL_MATRIX) {
3702     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3703     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3704   }
3705   PetscFunctionReturn(0);
3706 }
3707 
3708 PetscErrorCode MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3709 {
3710   PetscInt       m,cstart, cend,j,nnz,i,d;
3711   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3712   const PetscInt *JJ;
3713   PetscScalar    *values;
3714   PetscErrorCode ierr;
3715   PetscBool      nooffprocentries;
3716 
3717   PetscFunctionBegin;
3718   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3719 
3720   ierr   = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3721   ierr   = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3722   m      = B->rmap->n;
3723   cstart = B->cmap->rstart;
3724   cend   = B->cmap->rend;
3725   rstart = B->rmap->rstart;
3726 
3727   ierr = PetscMalloc2(m,&d_nnz,m,&o_nnz);CHKERRQ(ierr);
3728 
3729 #if defined(PETSC_USE_DEBUGGING)
3730   for (i=0; i<m; i++) {
3731     nnz = Ii[i+1]- Ii[i];
3732     JJ  = J + Ii[i];
3733     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3734     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3735     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);
3736   }
3737 #endif
3738 
3739   for (i=0; i<m; i++) {
3740     nnz     = Ii[i+1]- Ii[i];
3741     JJ      = J + Ii[i];
3742     nnz_max = PetscMax(nnz_max,nnz);
3743     d       = 0;
3744     for (j=0; j<nnz; j++) {
3745       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3746     }
3747     d_nnz[i] = d;
3748     o_nnz[i] = nnz - d;
3749   }
3750   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3751   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3752 
3753   if (v) values = (PetscScalar*)v;
3754   else {
3755     ierr = PetscCalloc1(nnz_max+1,&values);CHKERRQ(ierr);
3756   }
3757 
3758   for (i=0; i<m; i++) {
3759     ii   = i + rstart;
3760     nnz  = Ii[i+1]- Ii[i];
3761     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3762   }
3763   nooffprocentries    = B->nooffprocentries;
3764   B->nooffprocentries = PETSC_TRUE;
3765   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3766   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3767   B->nooffprocentries = nooffprocentries;
3768 
3769   if (!v) {
3770     ierr = PetscFree(values);CHKERRQ(ierr);
3771   }
3772   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3773   PetscFunctionReturn(0);
3774 }
3775 
3776 /*@
3777    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3778    (the default parallel PETSc format).
3779 
3780    Collective on MPI_Comm
3781 
3782    Input Parameters:
3783 +  B - the matrix
3784 .  i - the indices into j for the start of each local row (starts with zero)
3785 .  j - the column indices for each local row (starts with zero)
3786 -  v - optional values in the matrix
3787 
3788    Level: developer
3789 
3790    Notes:
3791        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3792      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3793      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3794 
3795        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3796 
3797        The format which is used for the sparse matrix input, is equivalent to a
3798     row-major ordering.. i.e for the following matrix, the input data expected is
3799     as shown
3800 
3801 $        1 0 0
3802 $        2 0 3     P0
3803 $       -------
3804 $        4 5 6     P1
3805 $
3806 $     Process0 [P0]: rows_owned=[0,1]
3807 $        i =  {0,1,3}  [size = nrow+1  = 2+1]
3808 $        j =  {0,0,2}  [size = 3]
3809 $        v =  {1,2,3}  [size = 3]
3810 $
3811 $     Process1 [P1]: rows_owned=[2]
3812 $        i =  {0,3}    [size = nrow+1  = 1+1]
3813 $        j =  {0,1,2}  [size = 3]
3814 $        v =  {4,5,6}  [size = 3]
3815 
3816 .keywords: matrix, aij, compressed row, sparse, parallel
3817 
3818 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MATMPIAIJ,
3819           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3820 @*/
3821 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3822 {
3823   PetscErrorCode ierr;
3824 
3825   PetscFunctionBegin;
3826   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
3827   PetscFunctionReturn(0);
3828 }
3829 
3830 /*@C
3831    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3832    (the default parallel PETSc format).  For good matrix assembly performance
3833    the user should preallocate the matrix storage by setting the parameters
3834    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3835    performance can be increased by more than a factor of 50.
3836 
3837    Collective on MPI_Comm
3838 
3839    Input Parameters:
3840 +  B - the matrix
3841 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3842            (same value is used for all local rows)
3843 .  d_nnz - array containing the number of nonzeros in the various rows of the
3844            DIAGONAL portion of the local submatrix (possibly different for each row)
3845            or NULL (PETSC_NULL_INTEGER in Fortran), if d_nz is used to specify the nonzero structure.
3846            The size of this array is equal to the number of local rows, i.e 'm'.
3847            For matrices that will be factored, you must leave room for (and set)
3848            the diagonal entry even if it is zero.
3849 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3850            submatrix (same value is used for all local rows).
3851 -  o_nnz - array containing the number of nonzeros in the various rows of the
3852            OFF-DIAGONAL portion of the local submatrix (possibly different for
3853            each row) or NULL (PETSC_NULL_INTEGER in Fortran), if o_nz is used to specify the nonzero
3854            structure. The size of this array is equal to the number
3855            of local rows, i.e 'm'.
3856 
3857    If the *_nnz parameter is given then the *_nz parameter is ignored
3858 
3859    The AIJ format (also called the Yale sparse matrix format or
3860    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3861    storage.  The stored row and column indices begin with zero.
3862    See Users-Manual: ch_mat for details.
3863 
3864    The parallel matrix is partitioned such that the first m0 rows belong to
3865    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3866    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3867 
3868    The DIAGONAL portion of the local submatrix of a processor can be defined
3869    as the submatrix which is obtained by extraction the part corresponding to
3870    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
3871    first row that belongs to the processor, r2 is the last row belonging to
3872    the this processor, and c1-c2 is range of indices of the local part of a
3873    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
3874    common case of a square matrix, the row and column ranges are the same and
3875    the DIAGONAL part is also square. The remaining portion of the local
3876    submatrix (mxN) constitute the OFF-DIAGONAL portion.
3877 
3878    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3879 
3880    You can call MatGetInfo() to get information on how effective the preallocation was;
3881    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3882    You can also run with the option -info and look for messages with the string
3883    malloc in them to see if additional memory allocation was needed.
3884 
3885    Example usage:
3886 
3887    Consider the following 8x8 matrix with 34 non-zero values, that is
3888    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3889    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3890    as follows:
3891 
3892 .vb
3893             1  2  0  |  0  3  0  |  0  4
3894     Proc0   0  5  6  |  7  0  0  |  8  0
3895             9  0 10  | 11  0  0  | 12  0
3896     -------------------------------------
3897            13  0 14  | 15 16 17  |  0  0
3898     Proc1   0 18  0  | 19 20 21  |  0  0
3899             0  0  0  | 22 23  0  | 24  0
3900     -------------------------------------
3901     Proc2  25 26 27  |  0  0 28  | 29  0
3902            30  0  0  | 31 32 33  |  0 34
3903 .ve
3904 
3905    This can be represented as a collection of submatrices as:
3906 
3907 .vb
3908       A B C
3909       D E F
3910       G H I
3911 .ve
3912 
3913    Where the submatrices A,B,C are owned by proc0, D,E,F are
3914    owned by proc1, G,H,I are owned by proc2.
3915 
3916    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3917    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3918    The 'M','N' parameters are 8,8, and have the same values on all procs.
3919 
3920    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3921    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3922    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3923    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3924    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3925    matrix, ans [DF] as another SeqAIJ matrix.
3926 
3927    When d_nz, o_nz parameters are specified, d_nz storage elements are
3928    allocated for every row of the local diagonal submatrix, and o_nz
3929    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3930    One way to choose d_nz and o_nz is to use the max nonzerors per local
3931    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3932    In this case, the values of d_nz,o_nz are:
3933 .vb
3934      proc0 : dnz = 2, o_nz = 2
3935      proc1 : dnz = 3, o_nz = 2
3936      proc2 : dnz = 1, o_nz = 4
3937 .ve
3938    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3939    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3940    for proc3. i.e we are using 12+15+10=37 storage locations to store
3941    34 values.
3942 
3943    When d_nnz, o_nnz parameters are specified, the storage is specified
3944    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3945    In the above case the values for d_nnz,o_nnz are:
3946 .vb
3947      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3948      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3949      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3950 .ve
3951    Here the space allocated is sum of all the above values i.e 34, and
3952    hence pre-allocation is perfect.
3953 
3954    Level: intermediate
3955 
3956 .keywords: matrix, aij, compressed row, sparse, parallel
3957 
3958 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
3959           MATMPIAIJ, MatGetInfo(), PetscSplitOwnership()
3960 @*/
3961 PetscErrorCode MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3962 {
3963   PetscErrorCode ierr;
3964 
3965   PetscFunctionBegin;
3966   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
3967   PetscValidType(B,1);
3968   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
3969   PetscFunctionReturn(0);
3970 }
3971 
3972 /*@
3973      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3974          CSR format the local rows.
3975 
3976    Collective on MPI_Comm
3977 
3978    Input Parameters:
3979 +  comm - MPI communicator
3980 .  m - number of local rows (Cannot be PETSC_DECIDE)
3981 .  n - This value should be the same as the local size used in creating the
3982        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3983        calculated if N is given) For square matrices n is almost always m.
3984 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3985 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3986 .   i - row indices
3987 .   j - column indices
3988 -   a - matrix values
3989 
3990    Output Parameter:
3991 .   mat - the matrix
3992 
3993    Level: intermediate
3994 
3995    Notes:
3996        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3997      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3998      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3999 
4000        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
4001 
4002        The format which is used for the sparse matrix input, is equivalent to a
4003     row-major ordering.. i.e for the following matrix, the input data expected is
4004     as shown
4005 
4006 $        1 0 0
4007 $        2 0 3     P0
4008 $       -------
4009 $        4 5 6     P1
4010 $
4011 $     Process0 [P0]: rows_owned=[0,1]
4012 $        i =  {0,1,3}  [size = nrow+1  = 2+1]
4013 $        j =  {0,0,2}  [size = 3]
4014 $        v =  {1,2,3}  [size = 3]
4015 $
4016 $     Process1 [P1]: rows_owned=[2]
4017 $        i =  {0,3}    [size = nrow+1  = 1+1]
4018 $        j =  {0,1,2}  [size = 3]
4019 $        v =  {4,5,6}  [size = 3]
4020 
4021 .keywords: matrix, aij, compressed row, sparse, parallel
4022 
4023 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4024           MATMPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
4025 @*/
4026 PetscErrorCode MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
4027 {
4028   PetscErrorCode ierr;
4029 
4030   PetscFunctionBegin;
4031   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
4032   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
4033   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
4034   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
4035   /* ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr); */
4036   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
4037   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
4038   PetscFunctionReturn(0);
4039 }
4040 
4041 /*@C
4042    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
4043    (the default parallel PETSc format).  For good matrix assembly performance
4044    the user should preallocate the matrix storage by setting the parameters
4045    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4046    performance can be increased by more than a factor of 50.
4047 
4048    Collective on MPI_Comm
4049 
4050    Input Parameters:
4051 +  comm - MPI communicator
4052 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
4053            This value should be the same as the local size used in creating the
4054            y vector for the matrix-vector product y = Ax.
4055 .  n - This value should be the same as the local size used in creating the
4056        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4057        calculated if N is given) For square matrices n is almost always m.
4058 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4059 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4060 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4061            (same value is used for all local rows)
4062 .  d_nnz - array containing the number of nonzeros in the various rows of the
4063            DIAGONAL portion of the local submatrix (possibly different for each row)
4064            or NULL, if d_nz is used to specify the nonzero structure.
4065            The size of this array is equal to the number of local rows, i.e 'm'.
4066 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4067            submatrix (same value is used for all local rows).
4068 -  o_nnz - array containing the number of nonzeros in the various rows of the
4069            OFF-DIAGONAL portion of the local submatrix (possibly different for
4070            each row) or NULL, if o_nz is used to specify the nonzero
4071            structure. The size of this array is equal to the number
4072            of local rows, i.e 'm'.
4073 
4074    Output Parameter:
4075 .  A - the matrix
4076 
4077    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
4078    MatXXXXSetPreallocation() paradgm instead of this routine directly.
4079    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
4080 
4081    Notes:
4082    If the *_nnz parameter is given then the *_nz parameter is ignored
4083 
4084    m,n,M,N parameters specify the size of the matrix, and its partitioning across
4085    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
4086    storage requirements for this matrix.
4087 
4088    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
4089    processor than it must be used on all processors that share the object for
4090    that argument.
4091 
4092    The user MUST specify either the local or global matrix dimensions
4093    (possibly both).
4094 
4095    The parallel matrix is partitioned across processors such that the
4096    first m0 rows belong to process 0, the next m1 rows belong to
4097    process 1, the next m2 rows belong to process 2 etc.. where
4098    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
4099    values corresponding to [m x N] submatrix.
4100 
4101    The columns are logically partitioned with the n0 columns belonging
4102    to 0th partition, the next n1 columns belonging to the next
4103    partition etc.. where n0,n1,n2... are the input parameter 'n'.
4104 
4105    The DIAGONAL portion of the local submatrix on any given processor
4106    is the submatrix corresponding to the rows and columns m,n
4107    corresponding to the given processor. i.e diagonal matrix on
4108    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4109    etc. The remaining portion of the local submatrix [m x (N-n)]
4110    constitute the OFF-DIAGONAL portion. The example below better
4111    illustrates this concept.
4112 
4113    For a square global matrix we define each processor's diagonal portion
4114    to be its local rows and the corresponding columns (a square submatrix);
4115    each processor's off-diagonal portion encompasses the remainder of the
4116    local matrix (a rectangular submatrix).
4117 
4118    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4119 
4120    When calling this routine with a single process communicator, a matrix of
4121    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
4122    type of communicator, use the construction mechanism
4123 .vb
4124      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
4125 .ve
4126 
4127 $     MatCreate(...,&A);
4128 $     MatSetType(A,MATMPIAIJ);
4129 $     MatSetSizes(A, m,n,M,N);
4130 $     MatMPIAIJSetPreallocation(A,...);
4131 
4132    By default, this format uses inodes (identical nodes) when possible.
4133    We search for consecutive rows with the same nonzero structure, thereby
4134    reusing matrix information to achieve increased efficiency.
4135 
4136    Options Database Keys:
4137 +  -mat_no_inode  - Do not use inodes
4138 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
4139 -  -mat_aij_oneindex - Internally use indexing starting at 1
4140         rather than 0.  Note that when calling MatSetValues(),
4141         the user still MUST index entries starting at 0!
4142 
4143 
4144    Example usage:
4145 
4146    Consider the following 8x8 matrix with 34 non-zero values, that is
4147    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4148    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4149    as follows
4150 
4151 .vb
4152             1  2  0  |  0  3  0  |  0  4
4153     Proc0   0  5  6  |  7  0  0  |  8  0
4154             9  0 10  | 11  0  0  | 12  0
4155     -------------------------------------
4156            13  0 14  | 15 16 17  |  0  0
4157     Proc1   0 18  0  | 19 20 21  |  0  0
4158             0  0  0  | 22 23  0  | 24  0
4159     -------------------------------------
4160     Proc2  25 26 27  |  0  0 28  | 29  0
4161            30  0  0  | 31 32 33  |  0 34
4162 .ve
4163 
4164    This can be represented as a collection of submatrices as
4165 
4166 .vb
4167       A B C
4168       D E F
4169       G H I
4170 .ve
4171 
4172    Where the submatrices A,B,C are owned by proc0, D,E,F are
4173    owned by proc1, G,H,I are owned by proc2.
4174 
4175    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4176    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4177    The 'M','N' parameters are 8,8, and have the same values on all procs.
4178 
4179    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4180    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4181    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4182    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4183    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4184    matrix, ans [DF] as another SeqAIJ matrix.
4185 
4186    When d_nz, o_nz parameters are specified, d_nz storage elements are
4187    allocated for every row of the local diagonal submatrix, and o_nz
4188    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4189    One way to choose d_nz and o_nz is to use the max nonzerors per local
4190    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4191    In this case, the values of d_nz,o_nz are
4192 .vb
4193      proc0 : dnz = 2, o_nz = 2
4194      proc1 : dnz = 3, o_nz = 2
4195      proc2 : dnz = 1, o_nz = 4
4196 .ve
4197    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4198    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4199    for proc3. i.e we are using 12+15+10=37 storage locations to store
4200    34 values.
4201 
4202    When d_nnz, o_nnz parameters are specified, the storage is specified
4203    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4204    In the above case the values for d_nnz,o_nnz are
4205 .vb
4206      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4207      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4208      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4209 .ve
4210    Here the space allocated is sum of all the above values i.e 34, and
4211    hence pre-allocation is perfect.
4212 
4213    Level: intermediate
4214 
4215 .keywords: matrix, aij, compressed row, sparse, parallel
4216 
4217 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4218           MATMPIAIJ, MatCreateMPIAIJWithArrays()
4219 @*/
4220 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)
4221 {
4222   PetscErrorCode ierr;
4223   PetscMPIInt    size;
4224 
4225   PetscFunctionBegin;
4226   ierr = MatCreate(comm,A);CHKERRQ(ierr);
4227   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
4228   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4229   if (size > 1) {
4230     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
4231     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
4232   } else {
4233     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
4234     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
4235   }
4236   PetscFunctionReturn(0);
4237 }
4238 
4239 PetscErrorCode MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,const PetscInt *colmap[])
4240 {
4241   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4242   PetscBool      flg;
4243   PetscErrorCode ierr;
4244 
4245   PetscFunctionBegin;
4246   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&flg);CHKERRQ(ierr);
4247   if (!flg) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"This function requires a MATMPIAIJ matrix as input");
4248   if (Ad)     *Ad     = a->A;
4249   if (Ao)     *Ao     = a->B;
4250   if (colmap) *colmap = a->garray;
4251   PetscFunctionReturn(0);
4252 }
4253 
4254 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_MPIAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
4255 {
4256   PetscErrorCode ierr;
4257   PetscInt       m,N,i,rstart,nnz,Ii;
4258   PetscInt       *indx;
4259   PetscScalar    *values;
4260 
4261   PetscFunctionBegin;
4262   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4263   if (scall == MAT_INITIAL_MATRIX) { /* symbolic phase */
4264     PetscInt       *dnz,*onz,sum,bs,cbs;
4265 
4266     if (n == PETSC_DECIDE) {
4267       ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
4268     }
4269     /* Check sum(n) = N */
4270     ierr = MPIU_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4271     if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
4272 
4273     ierr    = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4274     rstart -= m;
4275 
4276     ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4277     for (i=0; i<m; i++) {
4278       ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4279       ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
4280       ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4281     }
4282 
4283     ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
4284     ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4285     ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
4286     ierr = MatSetBlockSizes(*outmat,bs,cbs);CHKERRQ(ierr);
4287     ierr = MatSetType(*outmat,MATAIJ);CHKERRQ(ierr);
4288     ierr = MatSeqAIJSetPreallocation(*outmat,0,dnz);CHKERRQ(ierr);
4289     ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
4290     ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4291   }
4292 
4293   /* numeric phase */
4294   ierr = MatGetOwnershipRange(*outmat,&rstart,NULL);CHKERRQ(ierr);
4295   for (i=0; i<m; i++) {
4296     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4297     Ii   = i + rstart;
4298     ierr = MatSetValues(*outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4299     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4300   }
4301   ierr = MatAssemblyBegin(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4302   ierr = MatAssemblyEnd(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4303   PetscFunctionReturn(0);
4304 }
4305 
4306 PetscErrorCode MatFileSplit(Mat A,char *outfile)
4307 {
4308   PetscErrorCode    ierr;
4309   PetscMPIInt       rank;
4310   PetscInt          m,N,i,rstart,nnz;
4311   size_t            len;
4312   const PetscInt    *indx;
4313   PetscViewer       out;
4314   char              *name;
4315   Mat               B;
4316   const PetscScalar *values;
4317 
4318   PetscFunctionBegin;
4319   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
4320   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
4321   /* Should this be the type of the diagonal block of A? */
4322   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
4323   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
4324   ierr = MatSetBlockSizesFromMats(B,A,A);CHKERRQ(ierr);
4325   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
4326   ierr = MatSeqAIJSetPreallocation(B,0,NULL);CHKERRQ(ierr);
4327   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
4328   for (i=0; i<m; i++) {
4329     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4330     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4331     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4332   }
4333   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4334   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4335 
4336   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
4337   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
4338   ierr = PetscMalloc1(len+5,&name);CHKERRQ(ierr);
4339   sprintf(name,"%s.%d",outfile,rank);
4340   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
4341   ierr = PetscFree(name);CHKERRQ(ierr);
4342   ierr = MatView(B,out);CHKERRQ(ierr);
4343   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
4344   ierr = MatDestroy(&B);CHKERRQ(ierr);
4345   PetscFunctionReturn(0);
4346 }
4347 
4348 PetscErrorCode MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
4349 {
4350   PetscErrorCode      ierr;
4351   Mat_Merge_SeqsToMPI *merge;
4352   PetscContainer      container;
4353 
4354   PetscFunctionBegin;
4355   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4356   if (container) {
4357     ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4358     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
4359     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
4360     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
4361     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
4362     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
4363     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
4364     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
4365     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
4366     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
4367     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
4368     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
4369     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
4370     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
4371     ierr = PetscFree(merge);CHKERRQ(ierr);
4372     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
4373   }
4374   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
4375   PetscFunctionReturn(0);
4376 }
4377 
4378 #include <../src/mat/utils/freespace.h>
4379 #include <petscbt.h>
4380 
4381 PetscErrorCode MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
4382 {
4383   PetscErrorCode      ierr;
4384   MPI_Comm            comm;
4385   Mat_SeqAIJ          *a  =(Mat_SeqAIJ*)seqmat->data;
4386   PetscMPIInt         size,rank,taga,*len_s;
4387   PetscInt            N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj;
4388   PetscInt            proc,m;
4389   PetscInt            **buf_ri,**buf_rj;
4390   PetscInt            k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
4391   PetscInt            nrows,**buf_ri_k,**nextrow,**nextai;
4392   MPI_Request         *s_waits,*r_waits;
4393   MPI_Status          *status;
4394   MatScalar           *aa=a->a;
4395   MatScalar           **abuf_r,*ba_i;
4396   Mat_Merge_SeqsToMPI *merge;
4397   PetscContainer      container;
4398 
4399   PetscFunctionBegin;
4400   ierr = PetscObjectGetComm((PetscObject)mpimat,&comm);CHKERRQ(ierr);
4401   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4402 
4403   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4404   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4405 
4406   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4407   ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4408 
4409   bi     = merge->bi;
4410   bj     = merge->bj;
4411   buf_ri = merge->buf_ri;
4412   buf_rj = merge->buf_rj;
4413 
4414   ierr   = PetscMalloc1(size,&status);CHKERRQ(ierr);
4415   owners = merge->rowmap->range;
4416   len_s  = merge->len_s;
4417 
4418   /* send and recv matrix values */
4419   /*-----------------------------*/
4420   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
4421   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
4422 
4423   ierr = PetscMalloc1(merge->nsend+1,&s_waits);CHKERRQ(ierr);
4424   for (proc=0,k=0; proc<size; proc++) {
4425     if (!len_s[proc]) continue;
4426     i    = owners[proc];
4427     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4428     k++;
4429   }
4430 
4431   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4432   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4433   ierr = PetscFree(status);CHKERRQ(ierr);
4434 
4435   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4436   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4437 
4438   /* insert mat values of mpimat */
4439   /*----------------------------*/
4440   ierr = PetscMalloc1(N,&ba_i);CHKERRQ(ierr);
4441   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4442 
4443   for (k=0; k<merge->nrecv; k++) {
4444     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4445     nrows       = *(buf_ri_k[k]);
4446     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4447     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4448   }
4449 
4450   /* set values of ba */
4451   m = merge->rowmap->n;
4452   for (i=0; i<m; i++) {
4453     arow = owners[rank] + i;
4454     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4455     bnzi = bi[i+1] - bi[i];
4456     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4457 
4458     /* add local non-zero vals of this proc's seqmat into ba */
4459     anzi   = ai[arow+1] - ai[arow];
4460     aj     = a->j + ai[arow];
4461     aa     = a->a + ai[arow];
4462     nextaj = 0;
4463     for (j=0; nextaj<anzi; j++) {
4464       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4465         ba_i[j] += aa[nextaj++];
4466       }
4467     }
4468 
4469     /* add received vals into ba */
4470     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4471       /* i-th row */
4472       if (i == *nextrow[k]) {
4473         anzi   = *(nextai[k]+1) - *nextai[k];
4474         aj     = buf_rj[k] + *(nextai[k]);
4475         aa     = abuf_r[k] + *(nextai[k]);
4476         nextaj = 0;
4477         for (j=0; nextaj<anzi; j++) {
4478           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4479             ba_i[j] += aa[nextaj++];
4480           }
4481         }
4482         nextrow[k]++; nextai[k]++;
4483       }
4484     }
4485     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4486   }
4487   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4488   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4489 
4490   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4491   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4492   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4493   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4494   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4495   PetscFunctionReturn(0);
4496 }
4497 
4498 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4499 {
4500   PetscErrorCode      ierr;
4501   Mat                 B_mpi;
4502   Mat_SeqAIJ          *a=(Mat_SeqAIJ*)seqmat->data;
4503   PetscMPIInt         size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4504   PetscInt            **buf_rj,**buf_ri,**buf_ri_k;
4505   PetscInt            M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4506   PetscInt            len,proc,*dnz,*onz,bs,cbs;
4507   PetscInt            k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4508   PetscInt            nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4509   MPI_Request         *si_waits,*sj_waits,*ri_waits,*rj_waits;
4510   MPI_Status          *status;
4511   PetscFreeSpaceList  free_space=NULL,current_space=NULL;
4512   PetscBT             lnkbt;
4513   Mat_Merge_SeqsToMPI *merge;
4514   PetscContainer      container;
4515 
4516   PetscFunctionBegin;
4517   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4518 
4519   /* make sure it is a PETSc comm */
4520   ierr = PetscCommDuplicate(comm,&comm,NULL);CHKERRQ(ierr);
4521   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4522   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4523 
4524   ierr = PetscNew(&merge);CHKERRQ(ierr);
4525   ierr = PetscMalloc1(size,&status);CHKERRQ(ierr);
4526 
4527   /* determine row ownership */
4528   /*---------------------------------------------------------*/
4529   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4530   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4531   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4532   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4533   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4534   ierr = PetscMalloc1(size,&len_si);CHKERRQ(ierr);
4535   ierr = PetscMalloc1(size,&merge->len_s);CHKERRQ(ierr);
4536 
4537   m      = merge->rowmap->n;
4538   owners = merge->rowmap->range;
4539 
4540   /* determine the number of messages to send, their lengths */
4541   /*---------------------------------------------------------*/
4542   len_s = merge->len_s;
4543 
4544   len          = 0; /* length of buf_si[] */
4545   merge->nsend = 0;
4546   for (proc=0; proc<size; proc++) {
4547     len_si[proc] = 0;
4548     if (proc == rank) {
4549       len_s[proc] = 0;
4550     } else {
4551       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4552       len_s[proc]  = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4553     }
4554     if (len_s[proc]) {
4555       merge->nsend++;
4556       nrows = 0;
4557       for (i=owners[proc]; i<owners[proc+1]; i++) {
4558         if (ai[i+1] > ai[i]) nrows++;
4559       }
4560       len_si[proc] = 2*(nrows+1);
4561       len         += len_si[proc];
4562     }
4563   }
4564 
4565   /* determine the number and length of messages to receive for ij-structure */
4566   /*-------------------------------------------------------------------------*/
4567   ierr = PetscGatherNumberOfMessages(comm,NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4568   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4569 
4570   /* post the Irecv of j-structure */
4571   /*-------------------------------*/
4572   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4573   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4574 
4575   /* post the Isend of j-structure */
4576   /*--------------------------------*/
4577   ierr = PetscMalloc2(merge->nsend,&si_waits,merge->nsend,&sj_waits);CHKERRQ(ierr);
4578 
4579   for (proc=0, k=0; proc<size; proc++) {
4580     if (!len_s[proc]) continue;
4581     i    = owners[proc];
4582     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4583     k++;
4584   }
4585 
4586   /* receives and sends of j-structure are complete */
4587   /*------------------------------------------------*/
4588   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4589   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4590 
4591   /* send and recv i-structure */
4592   /*---------------------------*/
4593   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4594   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4595 
4596   ierr   = PetscMalloc1(len+1,&buf_s);CHKERRQ(ierr);
4597   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4598   for (proc=0,k=0; proc<size; proc++) {
4599     if (!len_s[proc]) continue;
4600     /* form outgoing message for i-structure:
4601          buf_si[0]:                 nrows to be sent
4602                [1:nrows]:           row index (global)
4603                [nrows+1:2*nrows+1]: i-structure index
4604     */
4605     /*-------------------------------------------*/
4606     nrows       = len_si[proc]/2 - 1;
4607     buf_si_i    = buf_si + nrows+1;
4608     buf_si[0]   = nrows;
4609     buf_si_i[0] = 0;
4610     nrows       = 0;
4611     for (i=owners[proc]; i<owners[proc+1]; i++) {
4612       anzi = ai[i+1] - ai[i];
4613       if (anzi) {
4614         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4615         buf_si[nrows+1]   = i-owners[proc]; /* local row index */
4616         nrows++;
4617       }
4618     }
4619     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4620     k++;
4621     buf_si += len_si[proc];
4622   }
4623 
4624   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4625   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4626 
4627   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4628   for (i=0; i<merge->nrecv; i++) {
4629     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);
4630   }
4631 
4632   ierr = PetscFree(len_si);CHKERRQ(ierr);
4633   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4634   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4635   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4636   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4637   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4638   ierr = PetscFree(status);CHKERRQ(ierr);
4639 
4640   /* compute a local seq matrix in each processor */
4641   /*----------------------------------------------*/
4642   /* allocate bi array and free space for accumulating nonzero column info */
4643   ierr  = PetscMalloc1(m+1,&bi);CHKERRQ(ierr);
4644   bi[0] = 0;
4645 
4646   /* create and initialize a linked list */
4647   nlnk = N+1;
4648   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4649 
4650   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4651   len  = ai[owners[rank+1]] - ai[owners[rank]];
4652   ierr = PetscFreeSpaceGet(PetscIntMultTruncate(2,len)+1,&free_space);CHKERRQ(ierr);
4653 
4654   current_space = free_space;
4655 
4656   /* determine symbolic info for each local row */
4657   ierr = PetscMalloc3(merge->nrecv,&buf_ri_k,merge->nrecv,&nextrow,merge->nrecv,&nextai);CHKERRQ(ierr);
4658 
4659   for (k=0; k<merge->nrecv; k++) {
4660     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4661     nrows       = *buf_ri_k[k];
4662     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4663     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4664   }
4665 
4666   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4667   len  = 0;
4668   for (i=0; i<m; i++) {
4669     bnzi = 0;
4670     /* add local non-zero cols of this proc's seqmat into lnk */
4671     arow  = owners[rank] + i;
4672     anzi  = ai[arow+1] - ai[arow];
4673     aj    = a->j + ai[arow];
4674     ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4675     bnzi += nlnk;
4676     /* add received col data into lnk */
4677     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4678       if (i == *nextrow[k]) { /* i-th row */
4679         anzi  = *(nextai[k]+1) - *nextai[k];
4680         aj    = buf_rj[k] + *nextai[k];
4681         ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4682         bnzi += nlnk;
4683         nextrow[k]++; nextai[k]++;
4684       }
4685     }
4686     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4687 
4688     /* if free space is not available, make more free space */
4689     if (current_space->local_remaining<bnzi) {
4690       ierr = PetscFreeSpaceGet(PetscIntSumTruncate(bnzi,current_space->total_array_size),&current_space);CHKERRQ(ierr);
4691       nspacedouble++;
4692     }
4693     /* copy data into free space, then initialize lnk */
4694     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4695     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4696 
4697     current_space->array           += bnzi;
4698     current_space->local_used      += bnzi;
4699     current_space->local_remaining -= bnzi;
4700 
4701     bi[i+1] = bi[i] + bnzi;
4702   }
4703 
4704   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4705 
4706   ierr = PetscMalloc1(bi[m]+1,&bj);CHKERRQ(ierr);
4707   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4708   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4709 
4710   /* create symbolic parallel matrix B_mpi */
4711   /*---------------------------------------*/
4712   ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
4713   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4714   if (n==PETSC_DECIDE) {
4715     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4716   } else {
4717     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4718   }
4719   ierr = MatSetBlockSizes(B_mpi,bs,cbs);CHKERRQ(ierr);
4720   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4721   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4722   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4723   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
4724 
4725   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
4726   B_mpi->assembled    = PETSC_FALSE;
4727   B_mpi->ops->destroy = MatDestroy_MPIAIJ_SeqsToMPI;
4728   merge->bi           = bi;
4729   merge->bj           = bj;
4730   merge->buf_ri       = buf_ri;
4731   merge->buf_rj       = buf_rj;
4732   merge->coi          = NULL;
4733   merge->coj          = NULL;
4734   merge->owners_co    = NULL;
4735 
4736   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4737 
4738   /* attach the supporting struct to B_mpi for reuse */
4739   ierr    = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4740   ierr    = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4741   ierr    = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4742   ierr    = PetscContainerDestroy(&container);CHKERRQ(ierr);
4743   *mpimat = B_mpi;
4744 
4745   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4746   PetscFunctionReturn(0);
4747 }
4748 
4749 /*@C
4750       MatCreateMPIAIJSumSeqAIJ - Creates a MATMPIAIJ matrix by adding sequential
4751                  matrices from each processor
4752 
4753     Collective on MPI_Comm
4754 
4755    Input Parameters:
4756 +    comm - the communicators the parallel matrix will live on
4757 .    seqmat - the input sequential matrices
4758 .    m - number of local rows (or PETSC_DECIDE)
4759 .    n - number of local columns (or PETSC_DECIDE)
4760 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4761 
4762    Output Parameter:
4763 .    mpimat - the parallel matrix generated
4764 
4765     Level: advanced
4766 
4767    Notes:
4768      The dimensions of the sequential matrix in each processor MUST be the same.
4769      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
4770      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
4771 @*/
4772 PetscErrorCode MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4773 {
4774   PetscErrorCode ierr;
4775   PetscMPIInt    size;
4776 
4777   PetscFunctionBegin;
4778   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4779   if (size == 1) {
4780     ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4781     if (scall == MAT_INITIAL_MATRIX) {
4782       ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
4783     } else {
4784       ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4785     }
4786     ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4787     PetscFunctionReturn(0);
4788   }
4789   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4790   if (scall == MAT_INITIAL_MATRIX) {
4791     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4792   }
4793   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
4794   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4795   PetscFunctionReturn(0);
4796 }
4797 
4798 /*@
4799      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MATMPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
4800           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
4801           with MatGetSize()
4802 
4803     Not Collective
4804 
4805    Input Parameters:
4806 +    A - the matrix
4807 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4808 
4809    Output Parameter:
4810 .    A_loc - the local sequential matrix generated
4811 
4812     Level: developer
4813 
4814 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
4815 
4816 @*/
4817 PetscErrorCode MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4818 {
4819   PetscErrorCode ierr;
4820   Mat_MPIAIJ     *mpimat=(Mat_MPIAIJ*)A->data;
4821   Mat_SeqAIJ     *mat,*a,*b;
4822   PetscInt       *ai,*aj,*bi,*bj,*cmap=mpimat->garray;
4823   MatScalar      *aa,*ba,*cam;
4824   PetscScalar    *ca;
4825   PetscInt       am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4826   PetscInt       *ci,*cj,col,ncols_d,ncols_o,jo;
4827   PetscBool      match;
4828   MPI_Comm       comm;
4829   PetscMPIInt    size;
4830 
4831   PetscFunctionBegin;
4832   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4833   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MATMPIAIJ matrix as input");
4834   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
4835   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4836   if (size == 1 && scall == MAT_REUSE_MATRIX) PetscFunctionReturn(0);
4837 
4838   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4839   a = (Mat_SeqAIJ*)(mpimat->A)->data;
4840   b = (Mat_SeqAIJ*)(mpimat->B)->data;
4841   ai = a->i; aj = a->j; bi = b->i; bj = b->j;
4842   aa = a->a; ba = b->a;
4843   if (scall == MAT_INITIAL_MATRIX) {
4844     if (size == 1) {
4845       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ai,aj,aa,A_loc);CHKERRQ(ierr);
4846       PetscFunctionReturn(0);
4847     }
4848 
4849     ierr  = PetscMalloc1(1+am,&ci);CHKERRQ(ierr);
4850     ci[0] = 0;
4851     for (i=0; i<am; i++) {
4852       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4853     }
4854     ierr = PetscMalloc1(1+ci[am],&cj);CHKERRQ(ierr);
4855     ierr = PetscMalloc1(1+ci[am],&ca);CHKERRQ(ierr);
4856     k    = 0;
4857     for (i=0; i<am; i++) {
4858       ncols_o = bi[i+1] - bi[i];
4859       ncols_d = ai[i+1] - ai[i];
4860       /* off-diagonal portion of A */
4861       for (jo=0; jo<ncols_o; jo++) {
4862         col = cmap[*bj];
4863         if (col >= cstart) break;
4864         cj[k]   = col; bj++;
4865         ca[k++] = *ba++;
4866       }
4867       /* diagonal portion of A */
4868       for (j=0; j<ncols_d; j++) {
4869         cj[k]   = cstart + *aj++;
4870         ca[k++] = *aa++;
4871       }
4872       /* off-diagonal portion of A */
4873       for (j=jo; j<ncols_o; j++) {
4874         cj[k]   = cmap[*bj++];
4875         ca[k++] = *ba++;
4876       }
4877     }
4878     /* put together the new matrix */
4879     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4880     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4881     /* Since these are PETSc arrays, change flags to free them as necessary. */
4882     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4883     mat->free_a  = PETSC_TRUE;
4884     mat->free_ij = PETSC_TRUE;
4885     mat->nonew   = 0;
4886   } else if (scall == MAT_REUSE_MATRIX) {
4887     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4888     ci = mat->i; cj = mat->j; cam = mat->a;
4889     for (i=0; i<am; i++) {
4890       /* off-diagonal portion of A */
4891       ncols_o = bi[i+1] - bi[i];
4892       for (jo=0; jo<ncols_o; jo++) {
4893         col = cmap[*bj];
4894         if (col >= cstart) break;
4895         *cam++ = *ba++; bj++;
4896       }
4897       /* diagonal portion of A */
4898       ncols_d = ai[i+1] - ai[i];
4899       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4900       /* off-diagonal portion of A */
4901       for (j=jo; j<ncols_o; j++) {
4902         *cam++ = *ba++; bj++;
4903       }
4904     }
4905   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
4906   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4907   PetscFunctionReturn(0);
4908 }
4909 
4910 /*@C
4911      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MATMPIAIJ matrix by taking all its local rows and NON-ZERO columns
4912 
4913     Not Collective
4914 
4915    Input Parameters:
4916 +    A - the matrix
4917 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4918 -    row, col - index sets of rows and columns to extract (or NULL)
4919 
4920    Output Parameter:
4921 .    A_loc - the local sequential matrix generated
4922 
4923     Level: developer
4924 
4925 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
4926 
4927 @*/
4928 PetscErrorCode MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
4929 {
4930   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
4931   PetscErrorCode ierr;
4932   PetscInt       i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
4933   IS             isrowa,iscola;
4934   Mat            *aloc;
4935   PetscBool      match;
4936 
4937   PetscFunctionBegin;
4938   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4939   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MATMPIAIJ matrix as input");
4940   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4941   if (!row) {
4942     start = A->rmap->rstart; end = A->rmap->rend;
4943     ierr  = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
4944   } else {
4945     isrowa = *row;
4946   }
4947   if (!col) {
4948     start = A->cmap->rstart;
4949     cmap  = a->garray;
4950     nzA   = a->A->cmap->n;
4951     nzB   = a->B->cmap->n;
4952     ierr  = PetscMalloc1(nzA+nzB, &idx);CHKERRQ(ierr);
4953     ncols = 0;
4954     for (i=0; i<nzB; i++) {
4955       if (cmap[i] < start) idx[ncols++] = cmap[i];
4956       else break;
4957     }
4958     imark = i;
4959     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
4960     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
4961     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
4962   } else {
4963     iscola = *col;
4964   }
4965   if (scall != MAT_INITIAL_MATRIX) {
4966     ierr    = PetscMalloc1(1,&aloc);CHKERRQ(ierr);
4967     aloc[0] = *A_loc;
4968   }
4969   ierr   = MatCreateSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
4970   *A_loc = aloc[0];
4971   ierr   = PetscFree(aloc);CHKERRQ(ierr);
4972   if (!row) {
4973     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
4974   }
4975   if (!col) {
4976     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
4977   }
4978   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4979   PetscFunctionReturn(0);
4980 }
4981 
4982 /*@C
4983     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
4984 
4985     Collective on Mat
4986 
4987    Input Parameters:
4988 +    A,B - the matrices in mpiaij format
4989 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4990 -    rowb, colb - index sets of rows and columns of B to extract (or NULL)
4991 
4992    Output Parameter:
4993 +    rowb, colb - index sets of rows and columns of B to extract
4994 -    B_seq - the sequential matrix generated
4995 
4996     Level: developer
4997 
4998 @*/
4999 PetscErrorCode MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
5000 {
5001   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5002   PetscErrorCode ierr;
5003   PetscInt       *idx,i,start,ncols,nzA,nzB,*cmap,imark;
5004   IS             isrowb,iscolb;
5005   Mat            *bseq=NULL;
5006 
5007   PetscFunctionBegin;
5008   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5009     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);
5010   }
5011   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5012 
5013   if (scall == MAT_INITIAL_MATRIX) {
5014     start = A->cmap->rstart;
5015     cmap  = a->garray;
5016     nzA   = a->A->cmap->n;
5017     nzB   = a->B->cmap->n;
5018     ierr  = PetscMalloc1(nzA+nzB, &idx);CHKERRQ(ierr);
5019     ncols = 0;
5020     for (i=0; i<nzB; i++) {  /* row < local row index */
5021       if (cmap[i] < start) idx[ncols++] = cmap[i];
5022       else break;
5023     }
5024     imark = i;
5025     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
5026     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5027     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
5028     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
5029   } else {
5030     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5031     isrowb  = *rowb; iscolb = *colb;
5032     ierr    = PetscMalloc1(1,&bseq);CHKERRQ(ierr);
5033     bseq[0] = *B_seq;
5034   }
5035   ierr   = MatCreateSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
5036   *B_seq = bseq[0];
5037   ierr   = PetscFree(bseq);CHKERRQ(ierr);
5038   if (!rowb) {
5039     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
5040   } else {
5041     *rowb = isrowb;
5042   }
5043   if (!colb) {
5044     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
5045   } else {
5046     *colb = iscolb;
5047   }
5048   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5049   PetscFunctionReturn(0);
5050 }
5051 
5052 /*
5053     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
5054     of the OFF-DIAGONAL portion of local A
5055 
5056     Collective on Mat
5057 
5058    Input Parameters:
5059 +    A,B - the matrices in mpiaij format
5060 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5061 
5062    Output Parameter:
5063 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
5064 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
5065 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
5066 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
5067 
5068     Level: developer
5069 
5070 */
5071 PetscErrorCode MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
5072 {
5073   VecScatter_MPI_General *gen_to,*gen_from;
5074   PetscErrorCode         ierr;
5075   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
5076   Mat_SeqAIJ             *b_oth;
5077   VecScatter             ctx =a->Mvctx;
5078   MPI_Comm               comm;
5079   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
5080   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
5081   PetscInt               *rvalues,*svalues;
5082   MatScalar              *b_otha,*bufa,*bufA;
5083   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
5084   MPI_Request            *rwaits = NULL,*swaits = NULL;
5085   MPI_Status             *sstatus,rstatus;
5086   PetscMPIInt            jj,size;
5087   PetscInt               *cols,sbs,rbs;
5088   PetscScalar            *vals;
5089 
5090   PetscFunctionBegin;
5091   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
5092   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
5093 
5094   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5095     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);
5096   }
5097   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5098   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
5099 
5100   if (size == 1) {
5101     startsj_s = NULL;
5102     bufa_ptr  = NULL;
5103     *B_oth    = NULL;
5104     PetscFunctionReturn(0);
5105   }
5106 
5107   gen_to   = (VecScatter_MPI_General*)ctx->todata;
5108   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
5109   nrecvs   = gen_from->n;
5110   nsends   = gen_to->n;
5111 
5112   ierr    = PetscMalloc2(nrecvs,&rwaits,nsends,&swaits);CHKERRQ(ierr);
5113   srow    = gen_to->indices;    /* local row index to be sent */
5114   sstarts = gen_to->starts;
5115   sprocs  = gen_to->procs;
5116   sstatus = gen_to->sstatus;
5117   sbs     = gen_to->bs;
5118   rstarts = gen_from->starts;
5119   rprocs  = gen_from->procs;
5120   rbs     = gen_from->bs;
5121 
5122   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5123   if (scall == MAT_INITIAL_MATRIX) {
5124     /* i-array */
5125     /*---------*/
5126     /*  post receives */
5127     ierr = PetscMalloc1(rbs*(rstarts[nrecvs] - rstarts[0]),&rvalues);CHKERRQ(ierr);
5128     for (i=0; i<nrecvs; i++) {
5129       rowlen = rvalues + rstarts[i]*rbs;
5130       nrows  = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
5131       ierr   = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5132     }
5133 
5134     /* pack the outgoing message */
5135     ierr = PetscMalloc2(nsends+1,&sstartsj,nrecvs+1,&rstartsj);CHKERRQ(ierr);
5136 
5137     sstartsj[0] = 0;
5138     rstartsj[0] = 0;
5139     len         = 0; /* total length of j or a array to be sent */
5140     k           = 0;
5141     ierr = PetscMalloc1(sbs*(sstarts[nsends] - sstarts[0]),&svalues);CHKERRQ(ierr);
5142     for (i=0; i<nsends; i++) {
5143       rowlen = svalues + sstarts[i]*sbs;
5144       nrows  = sstarts[i+1]-sstarts[i]; /* num of block rows */
5145       for (j=0; j<nrows; j++) {
5146         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5147         for (l=0; l<sbs; l++) {
5148           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr); /* rowlength */
5149 
5150           rowlen[j*sbs+l] = ncols;
5151 
5152           len += ncols;
5153           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr);
5154         }
5155         k++;
5156       }
5157       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5158 
5159       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5160     }
5161     /* recvs and sends of i-array are completed */
5162     i = nrecvs;
5163     while (i--) {
5164       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5165     }
5166     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5167     ierr = PetscFree(svalues);CHKERRQ(ierr);
5168 
5169     /* allocate buffers for sending j and a arrays */
5170     ierr = PetscMalloc1(len+1,&bufj);CHKERRQ(ierr);
5171     ierr = PetscMalloc1(len+1,&bufa);CHKERRQ(ierr);
5172 
5173     /* create i-array of B_oth */
5174     ierr = PetscMalloc1(aBn+2,&b_othi);CHKERRQ(ierr);
5175 
5176     b_othi[0] = 0;
5177     len       = 0; /* total length of j or a array to be received */
5178     k         = 0;
5179     for (i=0; i<nrecvs; i++) {
5180       rowlen = rvalues + rstarts[i]*rbs;
5181       nrows  = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be received */
5182       for (j=0; j<nrows; j++) {
5183         b_othi[k+1] = b_othi[k] + rowlen[j];
5184         ierr = PetscIntSumError(rowlen[j],len,&len);CHKERRQ(ierr);
5185         k++;
5186       }
5187       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5188     }
5189     ierr = PetscFree(rvalues);CHKERRQ(ierr);
5190 
5191     /* allocate space for j and a arrrays of B_oth */
5192     ierr = PetscMalloc1(b_othi[aBn]+1,&b_othj);CHKERRQ(ierr);
5193     ierr = PetscMalloc1(b_othi[aBn]+1,&b_otha);CHKERRQ(ierr);
5194 
5195     /* j-array */
5196     /*---------*/
5197     /*  post receives of j-array */
5198     for (i=0; i<nrecvs; i++) {
5199       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5200       ierr  = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5201     }
5202 
5203     /* pack the outgoing message j-array */
5204     k = 0;
5205     for (i=0; i<nsends; i++) {
5206       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5207       bufJ  = bufj+sstartsj[i];
5208       for (j=0; j<nrows; j++) {
5209         row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5210         for (ll=0; ll<sbs; ll++) {
5211           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5212           for (l=0; l<ncols; l++) {
5213             *bufJ++ = cols[l];
5214           }
5215           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5216         }
5217       }
5218       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5219     }
5220 
5221     /* recvs and sends of j-array are completed */
5222     i = nrecvs;
5223     while (i--) {
5224       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5225     }
5226     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5227   } else if (scall == MAT_REUSE_MATRIX) {
5228     sstartsj = *startsj_s;
5229     rstartsj = *startsj_r;
5230     bufa     = *bufa_ptr;
5231     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
5232     b_otha   = b_oth->a;
5233   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
5234 
5235   /* a-array */
5236   /*---------*/
5237   /*  post receives of a-array */
5238   for (i=0; i<nrecvs; i++) {
5239     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5240     ierr  = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5241   }
5242 
5243   /* pack the outgoing message a-array */
5244   k = 0;
5245   for (i=0; i<nsends; i++) {
5246     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5247     bufA  = bufa+sstartsj[i];
5248     for (j=0; j<nrows; j++) {
5249       row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5250       for (ll=0; ll<sbs; ll++) {
5251         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5252         for (l=0; l<ncols; l++) {
5253           *bufA++ = vals[l];
5254         }
5255         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5256       }
5257     }
5258     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5259   }
5260   /* recvs and sends of a-array are completed */
5261   i = nrecvs;
5262   while (i--) {
5263     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5264   }
5265   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5266   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
5267 
5268   if (scall == MAT_INITIAL_MATRIX) {
5269     /* put together the new matrix */
5270     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
5271 
5272     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5273     /* Since these are PETSc arrays, change flags to free them as necessary. */
5274     b_oth          = (Mat_SeqAIJ*)(*B_oth)->data;
5275     b_oth->free_a  = PETSC_TRUE;
5276     b_oth->free_ij = PETSC_TRUE;
5277     b_oth->nonew   = 0;
5278 
5279     ierr = PetscFree(bufj);CHKERRQ(ierr);
5280     if (!startsj_s || !bufa_ptr) {
5281       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
5282       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
5283     } else {
5284       *startsj_s = sstartsj;
5285       *startsj_r = rstartsj;
5286       *bufa_ptr  = bufa;
5287     }
5288   }
5289   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5290   PetscFunctionReturn(0);
5291 }
5292 
5293 /*@C
5294   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
5295 
5296   Not Collective
5297 
5298   Input Parameters:
5299 . A - The matrix in mpiaij format
5300 
5301   Output Parameter:
5302 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
5303 . colmap - A map from global column index to local index into lvec
5304 - multScatter - A scatter from the argument of a matrix-vector product to lvec
5305 
5306   Level: developer
5307 
5308 @*/
5309 #if defined(PETSC_USE_CTABLE)
5310 PetscErrorCode MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
5311 #else
5312 PetscErrorCode MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
5313 #endif
5314 {
5315   Mat_MPIAIJ *a;
5316 
5317   PetscFunctionBegin;
5318   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
5319   PetscValidPointer(lvec, 2);
5320   PetscValidPointer(colmap, 3);
5321   PetscValidPointer(multScatter, 4);
5322   a = (Mat_MPIAIJ*) A->data;
5323   if (lvec) *lvec = a->lvec;
5324   if (colmap) *colmap = a->colmap;
5325   if (multScatter) *multScatter = a->Mvctx;
5326   PetscFunctionReturn(0);
5327 }
5328 
5329 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat,MatType,MatReuse,Mat*);
5330 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat,MatType,MatReuse,Mat*);
5331 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat,MatType,MatReuse,Mat*);
5332 #if defined(PETSC_HAVE_ELEMENTAL)
5333 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat,MatType,MatReuse,Mat*);
5334 #endif
5335 #if defined(PETSC_HAVE_HYPRE)
5336 PETSC_INTERN PetscErrorCode MatConvert_AIJ_HYPRE(Mat,MatType,MatReuse,Mat*);
5337 PETSC_INTERN PetscErrorCode MatMatMatMult_Transpose_AIJ_AIJ(Mat,Mat,Mat,MatReuse,PetscReal,Mat*);
5338 #endif
5339 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_IS(Mat,MatType,MatReuse,Mat*);
5340 
5341 /*
5342     Computes (B'*A')' since computing B*A directly is untenable
5343 
5344                n                       p                          p
5345         (              )       (              )         (                  )
5346       m (      A       )  *  n (       B      )   =   m (         C        )
5347         (              )       (              )         (                  )
5348 
5349 */
5350 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
5351 {
5352   PetscErrorCode ierr;
5353   Mat            At,Bt,Ct;
5354 
5355   PetscFunctionBegin;
5356   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
5357   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
5358   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
5359   ierr = MatDestroy(&At);CHKERRQ(ierr);
5360   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
5361   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
5362   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
5363   PetscFunctionReturn(0);
5364 }
5365 
5366 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
5367 {
5368   PetscErrorCode ierr;
5369   PetscInt       m=A->rmap->n,n=B->cmap->n;
5370   Mat            Cmat;
5371 
5372   PetscFunctionBegin;
5373   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);
5374   ierr = MatCreate(PetscObjectComm((PetscObject)A),&Cmat);CHKERRQ(ierr);
5375   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5376   ierr = MatSetBlockSizesFromMats(Cmat,A,B);CHKERRQ(ierr);
5377   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
5378   ierr = MatMPIDenseSetPreallocation(Cmat,NULL);CHKERRQ(ierr);
5379   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5380   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5381 
5382   Cmat->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
5383 
5384   *C = Cmat;
5385   PetscFunctionReturn(0);
5386 }
5387 
5388 /* ----------------------------------------------------------------*/
5389 PETSC_INTERN PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
5390 {
5391   PetscErrorCode ierr;
5392 
5393   PetscFunctionBegin;
5394   if (scall == MAT_INITIAL_MATRIX) {
5395     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5396     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
5397     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5398   }
5399   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5400   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
5401   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5402   PetscFunctionReturn(0);
5403 }
5404 
5405 /*MC
5406    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
5407 
5408    Options Database Keys:
5409 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
5410 
5411   Level: beginner
5412 
5413 .seealso: MatCreateAIJ()
5414 M*/
5415 
5416 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
5417 {
5418   Mat_MPIAIJ     *b;
5419   PetscErrorCode ierr;
5420   PetscMPIInt    size;
5421 
5422   PetscFunctionBegin;
5423   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)B),&size);CHKERRQ(ierr);
5424 
5425   ierr          = PetscNewLog(B,&b);CHKERRQ(ierr);
5426   B->data       = (void*)b;
5427   ierr          = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
5428   B->assembled  = PETSC_FALSE;
5429   B->insertmode = NOT_SET_VALUES;
5430   b->size       = size;
5431 
5432   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)B),&b->rank);CHKERRQ(ierr);
5433 
5434   /* build cache for off array entries formed */
5435   ierr = MatStashCreate_Private(PetscObjectComm((PetscObject)B),1,&B->stash);CHKERRQ(ierr);
5436 
5437   b->donotstash  = PETSC_FALSE;
5438   b->colmap      = 0;
5439   b->garray      = 0;
5440   b->roworiented = PETSC_TRUE;
5441 
5442   /* stuff used for matrix vector multiply */
5443   b->lvec  = NULL;
5444   b->Mvctx = NULL;
5445 
5446   /* stuff for MatGetRow() */
5447   b->rowindices   = 0;
5448   b->rowvalues    = 0;
5449   b->getrowactive = PETSC_FALSE;
5450 
5451   /* flexible pointer used in CUSP/CUSPARSE classes */
5452   b->spptr = NULL;
5453 
5454   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetUseScalableIncreaseOverlap_C",MatMPIAIJSetUseScalableIncreaseOverlap_MPIAIJ);CHKERRQ(ierr);
5455   ierr = PetscObjectComposeFunction((PetscObject)B,"MatStoreValues_C",MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5456   ierr = PetscObjectComposeFunction((PetscObject)B,"MatRetrieveValues_C",MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5457   ierr = PetscObjectComposeFunction((PetscObject)B,"MatIsTranspose_C",MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5458   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5459   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5460   ierr = PetscObjectComposeFunction((PetscObject)B,"MatDiagonalScaleLocal_C",MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5461   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
5462   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5463   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5464 #if defined(PETSC_HAVE_ELEMENTAL)
5465   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_elemental_C",MatConvert_MPIAIJ_Elemental);CHKERRQ(ierr);
5466 #endif
5467 #if defined(PETSC_HAVE_HYPRE)
5468   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_hypre_C",MatConvert_AIJ_HYPRE);CHKERRQ(ierr);
5469 #endif
5470   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_is_C",MatConvert_MPIAIJ_IS);CHKERRQ(ierr);
5471   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5472   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5473   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5474 #if defined(PETSC_HAVE_HYPRE)
5475   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMatMult_transpose_mpiaij_mpiaij_C",MatMatMatMult_Transpose_AIJ_AIJ);CHKERRQ(ierr);
5476 #endif
5477   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5478   PetscFunctionReturn(0);
5479 }
5480 
5481 /*@C
5482      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5483          and "off-diagonal" part of the matrix in CSR format.
5484 
5485    Collective on MPI_Comm
5486 
5487    Input Parameters:
5488 +  comm - MPI communicator
5489 .  m - number of local rows (Cannot be PETSC_DECIDE)
5490 .  n - This value should be the same as the local size used in creating the
5491        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5492        calculated if N is given) For square matrices n is almost always m.
5493 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5494 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5495 .   i - row indices for "diagonal" portion of matrix
5496 .   j - column indices
5497 .   a - matrix values
5498 .   oi - row indices for "off-diagonal" portion of matrix
5499 .   oj - column indices
5500 -   oa - matrix values
5501 
5502    Output Parameter:
5503 .   mat - the matrix
5504 
5505    Level: advanced
5506 
5507    Notes:
5508        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5509        must free the arrays once the matrix has been destroyed and not before.
5510 
5511        The i and j indices are 0 based
5512 
5513        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5514 
5515        This sets local rows and cannot be used to set off-processor values.
5516 
5517        Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
5518        legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
5519        not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
5520        the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
5521        keep track of the underlying array. Use MatSetOption(A,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE) to disable all
5522        communication if it is known that only local entries will be set.
5523 
5524 .keywords: matrix, aij, compressed row, sparse, parallel
5525 
5526 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5527           MATMPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5528 @*/
5529 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)
5530 {
5531   PetscErrorCode ierr;
5532   Mat_MPIAIJ     *maij;
5533 
5534   PetscFunctionBegin;
5535   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5536   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5537   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5538   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5539   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5540   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5541   maij = (Mat_MPIAIJ*) (*mat)->data;
5542 
5543   (*mat)->preallocated = PETSC_TRUE;
5544 
5545   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5546   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5547 
5548   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5549   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5550 
5551   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5552   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5553   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5554   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5555 
5556   ierr = MatSetOption(*mat,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
5557   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5558   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5559   ierr = MatSetOption(*mat,MAT_NO_OFF_PROC_ENTRIES,PETSC_FALSE);CHKERRQ(ierr);
5560   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
5561   PetscFunctionReturn(0);
5562 }
5563 
5564 /*
5565     Special version for direct calls from Fortran
5566 */
5567 #include <petsc/private/fortranimpl.h>
5568 
5569 /* Change these macros so can be used in void function */
5570 #undef CHKERRQ
5571 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5572 #undef SETERRQ2
5573 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5574 #undef SETERRQ3
5575 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5576 #undef SETERRQ
5577 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5578 
5579 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5580 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5581 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5582 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5583 #else
5584 #endif
5585 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)
5586 {
5587   Mat            mat  = *mmat;
5588   PetscInt       m    = *mm, n = *mn;
5589   InsertMode     addv = *maddv;
5590   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
5591   PetscScalar    value;
5592   PetscErrorCode ierr;
5593 
5594   MatCheckPreallocated(mat,1);
5595   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
5596 
5597 #if defined(PETSC_USE_DEBUG)
5598   else if (mat->insertmode != addv) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5599 #endif
5600   {
5601     PetscInt  i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
5602     PetscInt  cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5603     PetscBool roworiented = aij->roworiented;
5604 
5605     /* Some Variables required in the macro */
5606     Mat        A                 = aij->A;
5607     Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
5608     PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5609     MatScalar  *aa               = a->a;
5610     PetscBool  ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
5611     Mat        B                 = aij->B;
5612     Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
5613     PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5614     MatScalar  *ba               = b->a;
5615 
5616     PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5617     PetscInt  nonew = a->nonew;
5618     MatScalar *ap1,*ap2;
5619 
5620     PetscFunctionBegin;
5621     for (i=0; i<m; i++) {
5622       if (im[i] < 0) continue;
5623 #if defined(PETSC_USE_DEBUG)
5624       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);
5625 #endif
5626       if (im[i] >= rstart && im[i] < rend) {
5627         row      = im[i] - rstart;
5628         lastcol1 = -1;
5629         rp1      = aj + ai[row];
5630         ap1      = aa + ai[row];
5631         rmax1    = aimax[row];
5632         nrow1    = ailen[row];
5633         low1     = 0;
5634         high1    = nrow1;
5635         lastcol2 = -1;
5636         rp2      = bj + bi[row];
5637         ap2      = ba + bi[row];
5638         rmax2    = bimax[row];
5639         nrow2    = bilen[row];
5640         low2     = 0;
5641         high2    = nrow2;
5642 
5643         for (j=0; j<n; j++) {
5644           if (roworiented) value = v[i*n+j];
5645           else value = v[i+j*m];
5646           if (in[j] >= cstart && in[j] < cend) {
5647             col = in[j] - cstart;
5648             if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES) && row != col) continue;
5649             MatSetValues_SeqAIJ_A_Private(row,col,value,addv,im[i],in[j]);
5650           } else if (in[j] < 0) continue;
5651 #if defined(PETSC_USE_DEBUG)
5652           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);
5653 #endif
5654           else {
5655             if (mat->was_assembled) {
5656               if (!aij->colmap) {
5657                 ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5658               }
5659 #if defined(PETSC_USE_CTABLE)
5660               ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5661               col--;
5662 #else
5663               col = aij->colmap[in[j]] - 1;
5664 #endif
5665               if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES) && row != col) continue;
5666               if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5667                 ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5668                 col  =  in[j];
5669                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5670                 B     = aij->B;
5671                 b     = (Mat_SeqAIJ*)B->data;
5672                 bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5673                 rp2   = bj + bi[row];
5674                 ap2   = ba + bi[row];
5675                 rmax2 = bimax[row];
5676                 nrow2 = bilen[row];
5677                 low2  = 0;
5678                 high2 = nrow2;
5679                 bm    = aij->B->rmap->n;
5680                 ba    = b->a;
5681               }
5682             } else col = in[j];
5683             MatSetValues_SeqAIJ_B_Private(row,col,value,addv,im[i],in[j]);
5684           }
5685         }
5686       } else if (!aij->donotstash) {
5687         if (roworiented) {
5688           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5689         } else {
5690           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5691         }
5692       }
5693     }
5694   }
5695   PetscFunctionReturnVoid();
5696 }
5697 
5698