xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 6909748b0d34642f34d7ed20e8a413a43e8f8109)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>   /*I "petscmat.h" I*/
3 #include <petsc-private/vecimpl.h>
4 #include <petscblaslapack.h>
5 #include <petscsf.h>
6 
7 /*MC
8    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
9 
10    This matrix type is identical to MATSEQAIJ when constructed with a single process communicator,
11    and MATMPIAIJ otherwise.  As a result, for single process communicators,
12   MatSeqAIJSetPreallocation is supported, and similarly MatMPIAIJSetPreallocation is supported
13   for communicators controlling multiple processes.  It is recommended that you call both of
14   the above preallocation routines for simplicity.
15 
16    Options Database Keys:
17 . -mat_type aij - sets the matrix type to "aij" during a call to MatSetFromOptions()
18 
19   Developer Notes: Subclasses include MATAIJCUSP, MATAIJCUSPARSE, MATAIJPERM, MATAIJCRL, and also automatically switches over to use inodes when
20    enough exist.
21 
22   Level: beginner
23 
24 .seealso: MatCreateAIJ(), MatCreateSeqAIJ(), MATSEQAIJ,MATMPIAIJ
25 M*/
26 
27 /*MC
28    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
29 
30    This matrix type is identical to MATSEQAIJCRL when constructed with a single process communicator,
31    and MATMPIAIJCRL otherwise.  As a result, for single process communicators,
32    MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
33   for communicators controlling multiple processes.  It is recommended that you call both of
34   the above preallocation routines for simplicity.
35 
36    Options Database Keys:
37 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to MatSetFromOptions()
38 
39   Level: beginner
40 
41 .seealso: MatCreateMPIAIJCRL,MATSEQAIJCRL,MATMPIAIJCRL, MATSEQAIJCRL, MATMPIAIJCRL
42 M*/
43 
44 #undef __FUNCT__
45 #define __FUNCT__ "MatFindNonzeroRows_MPIAIJ"
46 PetscErrorCode MatFindNonzeroRows_MPIAIJ(Mat M,IS *keptrows)
47 {
48   PetscErrorCode  ierr;
49   Mat_MPIAIJ      *mat = (Mat_MPIAIJ*)M->data;
50   Mat_SeqAIJ      *a   = (Mat_SeqAIJ*)mat->A->data;
51   Mat_SeqAIJ      *b   = (Mat_SeqAIJ*)mat->B->data;
52   const PetscInt  *ia,*ib;
53   const MatScalar *aa,*bb;
54   PetscInt        na,nb,i,j,*rows,cnt=0,n0rows;
55   PetscInt        m = M->rmap->n,rstart = M->rmap->rstart;
56 
57   PetscFunctionBegin;
58   *keptrows = 0;
59   ia        = a->i;
60   ib        = b->i;
61   for (i=0; i<m; i++) {
62     na = ia[i+1] - ia[i];
63     nb = ib[i+1] - ib[i];
64     if (!na && !nb) {
65       cnt++;
66       goto ok1;
67     }
68     aa = a->a + ia[i];
69     for (j=0; j<na; j++) {
70       if (aa[j] != 0.0) goto ok1;
71     }
72     bb = b->a + ib[i];
73     for (j=0; j <nb; j++) {
74       if (bb[j] != 0.0) goto ok1;
75     }
76     cnt++;
77 ok1:;
78   }
79   ierr = MPI_Allreduce(&cnt,&n0rows,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)M));CHKERRQ(ierr);
80   if (!n0rows) PetscFunctionReturn(0);
81   ierr = PetscMalloc((M->rmap->n-cnt)*sizeof(PetscInt),&rows);CHKERRQ(ierr);
82   cnt  = 0;
83   for (i=0; i<m; i++) {
84     na = ia[i+1] - ia[i];
85     nb = ib[i+1] - ib[i];
86     if (!na && !nb) continue;
87     aa = a->a + ia[i];
88     for (j=0; j<na;j++) {
89       if (aa[j] != 0.0) {
90         rows[cnt++] = rstart + i;
91         goto ok2;
92       }
93     }
94     bb = b->a + ib[i];
95     for (j=0; j<nb; j++) {
96       if (bb[j] != 0.0) {
97         rows[cnt++] = rstart + i;
98         goto ok2;
99       }
100     }
101 ok2:;
102   }
103   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),cnt,rows,PETSC_OWN_POINTER,keptrows);CHKERRQ(ierr);
104   PetscFunctionReturn(0);
105 }
106 
107 #undef __FUNCT__
108 #define __FUNCT__ "MatFindZeroDiagonals_MPIAIJ"
109 PetscErrorCode MatFindZeroDiagonals_MPIAIJ(Mat M,IS *zrows)
110 {
111   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)M->data;
112   PetscErrorCode ierr;
113   PetscInt       i,rstart,nrows,*rows;
114 
115   PetscFunctionBegin;
116   *zrows = NULL;
117   ierr   = MatFindZeroDiagonals_SeqAIJ_Private(aij->A,&nrows,&rows);CHKERRQ(ierr);
118   ierr   = MatGetOwnershipRange(M,&rstart,NULL);CHKERRQ(ierr);
119   for (i=0; i<nrows; i++) rows[i] += rstart;
120   ierr = ISCreateGeneral(PetscObjectComm((PetscObject)M),nrows,rows,PETSC_OWN_POINTER,zrows);CHKERRQ(ierr);
121   PetscFunctionReturn(0);
122 }
123 
124 #undef __FUNCT__
125 #define __FUNCT__ "MatGetColumnNorms_MPIAIJ"
126 PetscErrorCode MatGetColumnNorms_MPIAIJ(Mat A,NormType type,PetscReal *norms)
127 {
128   PetscErrorCode ierr;
129   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)A->data;
130   PetscInt       i,n,*garray = aij->garray;
131   Mat_SeqAIJ     *a_aij = (Mat_SeqAIJ*) aij->A->data;
132   Mat_SeqAIJ     *b_aij = (Mat_SeqAIJ*) aij->B->data;
133   PetscReal      *work;
134 
135   PetscFunctionBegin;
136   ierr = MatGetSize(A,NULL,&n);CHKERRQ(ierr);
137   ierr = PetscMalloc(n*sizeof(PetscReal),&work);CHKERRQ(ierr);
138   ierr = PetscMemzero(work,n*sizeof(PetscReal));CHKERRQ(ierr);
139   if (type == NORM_2) {
140     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
141       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]*a_aij->a[i]);
142     }
143     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
144       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]*b_aij->a[i]);
145     }
146   } else if (type == NORM_1) {
147     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
148       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
149     }
150     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
151       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
152     }
153   } else if (type == NORM_INFINITY) {
154     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
155       work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
156     }
157     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
158       work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]),work[garray[b_aij->j[i]]]);
159     }
160 
161   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONG,"Unknown NormType");
162   if (type == NORM_INFINITY) {
163     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_MAX,A->hdr.comm);CHKERRQ(ierr);
164   } else {
165     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_SUM,A->hdr.comm);CHKERRQ(ierr);
166   }
167   ierr = PetscFree(work);CHKERRQ(ierr);
168   if (type == NORM_2) {
169     for (i=0; i<n; i++) norms[i] = PetscSqrtReal(norms[i]);
170   }
171   PetscFunctionReturn(0);
172 }
173 
174 #undef __FUNCT__
175 #define __FUNCT__ "MatDistribute_MPIAIJ"
176 /*
177     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
178     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
179 
180     Only for square matrices
181 
182     Used by a preconditioner, hence PETSC_EXTERN
183 */
184 PETSC_EXTERN PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
185 {
186   PetscMPIInt    rank,size;
187   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz,*gmataj,cnt,row,*ld,bses[2];
188   PetscErrorCode ierr;
189   Mat            mat;
190   Mat_SeqAIJ     *gmata;
191   PetscMPIInt    tag;
192   MPI_Status     status;
193   PetscBool      aij;
194   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
195 
196   PetscFunctionBegin;
197   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
198   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
199   if (!rank) {
200     ierr = PetscObjectTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
201     if (!aij) SETERRQ1(PetscObjectComm((PetscObject)gmat),PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
202   }
203   if (reuse == MAT_INITIAL_MATRIX) {
204     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
205     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
206     if (!rank) {
207       bses[0] = gmat->rmap->bs;
208       bses[1] = gmat->cmap->bs;
209     }
210     ierr = MPI_Bcast(bses,2,MPIU_INT,0,comm);CHKERRQ(ierr);
211     ierr = MatSetBlockSizes(mat,bses[0],bses[1]);CHKERRQ(ierr);
212     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
213     ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
214     ierr = PetscMalloc2(m,PetscInt,&dlens,m,PetscInt,&olens);CHKERRQ(ierr);
215     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
216 
217     rowners[0] = 0;
218     for (i=2; i<=size; i++) rowners[i] += rowners[i-1];
219     rstart = rowners[rank];
220     rend   = rowners[rank+1];
221     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
222     if (!rank) {
223       gmata = (Mat_SeqAIJ*) gmat->data;
224       /* send row lengths to all processors */
225       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
226       for (i=1; i<size; i++) {
227         ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
228       }
229       /* determine number diagonal and off-diagonal counts */
230       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
231       ierr = PetscMalloc(m*sizeof(PetscInt),&ld);CHKERRQ(ierr);
232       ierr = PetscMemzero(ld,m*sizeof(PetscInt));CHKERRQ(ierr);
233       jj   = 0;
234       for (i=0; i<m; i++) {
235         for (j=0; j<dlens[i]; j++) {
236           if (gmata->j[jj] < rstart) ld[i]++;
237           if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
238           jj++;
239         }
240       }
241       /* send column indices to other processes */
242       for (i=1; i<size; i++) {
243         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
244         ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
245         ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
246       }
247 
248       /* send numerical values to other processes */
249       for (i=1; i<size; i++) {
250         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
251         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
252       }
253       gmataa = gmata->a;
254       gmataj = gmata->j;
255 
256     } else {
257       /* receive row lengths */
258       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
259       /* receive column indices */
260       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
261       ierr = PetscMalloc2(nz,PetscScalar,&gmataa,nz,PetscInt,&gmataj);CHKERRQ(ierr);
262       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
263       /* determine number diagonal and off-diagonal counts */
264       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
265       ierr = PetscMalloc(m*sizeof(PetscInt),&ld);CHKERRQ(ierr);
266       ierr = PetscMemzero(ld,m*sizeof(PetscInt));CHKERRQ(ierr);
267       jj   = 0;
268       for (i=0; i<m; i++) {
269         for (j=0; j<dlens[i]; j++) {
270           if (gmataj[jj] < rstart) ld[i]++;
271           if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
272           jj++;
273         }
274       }
275       /* receive numerical values */
276       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
277       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
278     }
279     /* set preallocation */
280     for (i=0; i<m; i++) {
281       dlens[i] -= olens[i];
282     }
283     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
284     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
285 
286     for (i=0; i<m; i++) {
287       dlens[i] += olens[i];
288     }
289     cnt = 0;
290     for (i=0; i<m; i++) {
291       row  = rstart + i;
292       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
293       cnt += dlens[i];
294     }
295     if (rank) {
296       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
297     }
298     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
299     ierr = PetscFree(rowners);CHKERRQ(ierr);
300 
301     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
302 
303     *inmat = mat;
304   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
305     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
306     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
307     mat  = *inmat;
308     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
309     if (!rank) {
310       /* send numerical values to other processes */
311       gmata  = (Mat_SeqAIJ*) gmat->data;
312       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
313       gmataa = gmata->a;
314       for (i=1; i<size; i++) {
315         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
316         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
317       }
318       nz = gmata->i[rowners[1]]-gmata->i[rowners[0]];
319     } else {
320       /* receive numerical values from process 0*/
321       nz   = Ad->nz + Ao->nz;
322       ierr = PetscMalloc(nz*sizeof(PetscScalar),&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
323       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
324     }
325     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
326     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
327     ad = Ad->a;
328     ao = Ao->a;
329     if (mat->rmap->n) {
330       i  = 0;
331       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
332       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
333     }
334     for (i=1; i<mat->rmap->n; i++) {
335       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;
336       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
337     }
338     i--;
339     if (mat->rmap->n) {
340       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
341     }
342     if (rank) {
343       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
344     }
345   }
346   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
347   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
348   PetscFunctionReturn(0);
349 }
350 
351 /*
352   Local utility routine that creates a mapping from the global column
353 number to the local number in the off-diagonal part of the local
354 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
355 a slightly higher hash table cost; without it it is not scalable (each processor
356 has an order N integer array but is fast to acess.
357 */
358 #undef __FUNCT__
359 #define __FUNCT__ "MatCreateColmap_MPIAIJ_Private"
360 PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
361 {
362   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
363   PetscErrorCode ierr;
364   PetscInt       n = aij->B->cmap->n,i;
365 
366   PetscFunctionBegin;
367   if (!aij->garray) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPIAIJ Matrix was assembled but is missing garray");
368 #if defined(PETSC_USE_CTABLE)
369   ierr = PetscTableCreate(n,mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
370   for (i=0; i<n; i++) {
371     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1,INSERT_VALUES);CHKERRQ(ierr);
372   }
373 #else
374   ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscInt),&aij->colmap);CHKERRQ(ierr);
375   ierr = PetscLogObjectMemory(mat,mat->cmap->N*sizeof(PetscInt));CHKERRQ(ierr);
376   ierr = PetscMemzero(aij->colmap,mat->cmap->N*sizeof(PetscInt));CHKERRQ(ierr);
377   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
378 #endif
379   PetscFunctionReturn(0);
380 }
381 
382 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv) \
383 { \
384     if (col <= lastcol1)  low1 = 0;     \
385     else                 high1 = nrow1; \
386     lastcol1 = col;\
387     while (high1-low1 > 5) { \
388       t = (low1+high1)/2; \
389       if (rp1[t] > col) high1 = t; \
390       else              low1  = t; \
391     } \
392       for (_i=low1; _i<high1; _i++) { \
393         if (rp1[_i] > col) break; \
394         if (rp1[_i] == col) { \
395           if (addv == ADD_VALUES) ap1[_i] += value;   \
396           else                    ap1[_i] = value; \
397           goto a_noinsert; \
398         } \
399       }  \
400       if (value == 0.0 && ignorezeroentries) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
401       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}                \
402       if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
403       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
404       N = nrow1++ - 1; a->nz++; high1++; \
405       /* shift up all the later entries in this row */ \
406       for (ii=N; ii>=_i; ii--) { \
407         rp1[ii+1] = rp1[ii]; \
408         ap1[ii+1] = ap1[ii]; \
409       } \
410       rp1[_i] = col;  \
411       ap1[_i] = value;  \
412       a_noinsert: ; \
413       ailen[row] = nrow1; \
414 }
415 
416 
417 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv) \
418   { \
419     if (col <= lastcol2) low2 = 0;                        \
420     else high2 = nrow2;                                   \
421     lastcol2 = col;                                       \
422     while (high2-low2 > 5) {                              \
423       t = (low2+high2)/2;                                 \
424       if (rp2[t] > col) high2 = t;                        \
425       else             low2  = t;                         \
426     }                                                     \
427     for (_i=low2; _i<high2; _i++) {                       \
428       if (rp2[_i] > col) break;                           \
429       if (rp2[_i] == col) {                               \
430         if (addv == ADD_VALUES) ap2[_i] += value;         \
431         else                    ap2[_i] = value;          \
432         goto b_noinsert;                                  \
433       }                                                   \
434     }                                                     \
435     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
436     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}                        \
437     if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
438     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
439     N = nrow2++ - 1; b->nz++; high2++;                    \
440     /* shift up all the later entries in this row */      \
441     for (ii=N; ii>=_i; ii--) {                            \
442       rp2[ii+1] = rp2[ii];                                \
443       ap2[ii+1] = ap2[ii];                                \
444     }                                                     \
445     rp2[_i] = col;                                        \
446     ap2[_i] = value;                                      \
447     b_noinsert: ;                                         \
448     bilen[row] = nrow2;                                   \
449   }
450 
451 #undef __FUNCT__
452 #define __FUNCT__ "MatSetValuesRow_MPIAIJ"
453 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
454 {
455   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
456   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
457   PetscErrorCode ierr;
458   PetscInt       l,*garray = mat->garray,diag;
459 
460   PetscFunctionBegin;
461   /* code only works for square matrices A */
462 
463   /* find size of row to the left of the diagonal part */
464   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
465   row  = row - diag;
466   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
467     if (garray[b->j[b->i[row]+l]] > diag) break;
468   }
469   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
470 
471   /* diagonal part */
472   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
473 
474   /* right of diagonal part */
475   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);
476   PetscFunctionReturn(0);
477 }
478 
479 #undef __FUNCT__
480 #define __FUNCT__ "MatSetValues_MPIAIJ"
481 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
482 {
483   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
484   PetscScalar    value;
485   PetscErrorCode ierr;
486   PetscInt       i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
487   PetscInt       cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
488   PetscBool      roworiented = aij->roworiented;
489 
490   /* Some Variables required in the macro */
491   Mat        A                 = aij->A;
492   Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
493   PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
494   MatScalar  *aa               = a->a;
495   PetscBool  ignorezeroentries = a->ignorezeroentries;
496   Mat        B                 = aij->B;
497   Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
498   PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
499   MatScalar  *ba               = b->a;
500 
501   PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
502   PetscInt  nonew;
503   MatScalar *ap1,*ap2;
504 
505   PetscFunctionBegin;
506   if (v) PetscValidScalarPointer(v,6);
507   for (i=0; i<m; i++) {
508     if (im[i] < 0) continue;
509 #if defined(PETSC_USE_DEBUG)
510     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);
511 #endif
512     if (im[i] >= rstart && im[i] < rend) {
513       row      = im[i] - rstart;
514       lastcol1 = -1;
515       rp1      = aj + ai[row];
516       ap1      = aa + ai[row];
517       rmax1    = aimax[row];
518       nrow1    = ailen[row];
519       low1     = 0;
520       high1    = nrow1;
521       lastcol2 = -1;
522       rp2      = bj + bi[row];
523       ap2      = ba + bi[row];
524       rmax2    = bimax[row];
525       nrow2    = bilen[row];
526       low2     = 0;
527       high2    = nrow2;
528 
529       for (j=0; j<n; j++) {
530         if (v) {
531           if (roworiented) value = v[i*n+j];
532           else             value = v[i+j*m];
533         } else value = 0.0;
534         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
535         if (in[j] >= cstart && in[j] < cend) {
536           col   = in[j] - cstart;
537           nonew = a->nonew;
538           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
539         } else if (in[j] < 0) continue;
540 #if defined(PETSC_USE_DEBUG)
541         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);
542 #endif
543         else {
544           if (mat->was_assembled) {
545             if (!aij->colmap) {
546               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
547             }
548 #if defined(PETSC_USE_CTABLE)
549             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
550             col--;
551 #else
552             col = aij->colmap[in[j]] - 1;
553 #endif
554             if (col < 0 && !((Mat_SeqAIJ*)(aij->B->data))->nonew) {
555               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
556               col  =  in[j];
557               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
558               B     = aij->B;
559               b     = (Mat_SeqAIJ*)B->data;
560               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
561               rp2   = bj + bi[row];
562               ap2   = ba + bi[row];
563               rmax2 = bimax[row];
564               nrow2 = bilen[row];
565               low2  = 0;
566               high2 = nrow2;
567               bm    = aij->B->rmap->n;
568               ba    = b->a;
569             } else if (col < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", im[i], in[j]);
570           } else col = in[j];
571           nonew = b->nonew;
572           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
573         }
574       }
575     } else {
576       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]);
577       if (!aij->donotstash) {
578         mat->assembled = PETSC_FALSE;
579         if (roworiented) {
580           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
581         } else {
582           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
583         }
584       }
585     }
586   }
587   PetscFunctionReturn(0);
588 }
589 
590 #undef __FUNCT__
591 #define __FUNCT__ "MatGetValues_MPIAIJ"
592 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
593 {
594   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
595   PetscErrorCode ierr;
596   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
597   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
598 
599   PetscFunctionBegin;
600   for (i=0; i<m; i++) {
601     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
602     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);
603     if (idxm[i] >= rstart && idxm[i] < rend) {
604       row = idxm[i] - rstart;
605       for (j=0; j<n; j++) {
606         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
607         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);
608         if (idxn[j] >= cstart && idxn[j] < cend) {
609           col  = idxn[j] - cstart;
610           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
611         } else {
612           if (!aij->colmap) {
613             ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
614           }
615 #if defined(PETSC_USE_CTABLE)
616           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
617           col--;
618 #else
619           col = aij->colmap[idxn[j]] - 1;
620 #endif
621           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
622           else {
623             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
624           }
625         }
626       }
627     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only local values currently supported");
628   }
629   PetscFunctionReturn(0);
630 }
631 
632 extern PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat,Vec,Vec);
633 
634 #undef __FUNCT__
635 #define __FUNCT__ "MatAssemblyBegin_MPIAIJ"
636 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
637 {
638   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
639   PetscErrorCode ierr;
640   PetscInt       nstash,reallocs;
641   InsertMode     addv;
642 
643   PetscFunctionBegin;
644   if (aij->donotstash || mat->nooffprocentries) PetscFunctionReturn(0);
645 
646   /* make sure all processors are either in INSERTMODE or ADDMODE */
647   ierr = MPI_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
648   if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
649   mat->insertmode = addv; /* in case this processor had no cache */
650 
651   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
652   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
653   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
654   PetscFunctionReturn(0);
655 }
656 
657 #undef __FUNCT__
658 #define __FUNCT__ "MatAssemblyEnd_MPIAIJ"
659 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
660 {
661   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
662   Mat_SeqAIJ     *a   = (Mat_SeqAIJ*)aij->A->data;
663   PetscErrorCode ierr;
664   PetscMPIInt    n;
665   PetscInt       i,j,rstart,ncols,flg;
666   PetscInt       *row,*col;
667   PetscBool      other_disassembled;
668   PetscScalar    *val;
669   InsertMode     addv = mat->insertmode;
670 
671   /* do not use 'b = (Mat_SeqAIJ*)aij->B->data' as B can be reset in disassembly */
672 
673   PetscFunctionBegin;
674   if (!aij->donotstash && !mat->nooffprocentries) {
675     while (1) {
676       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
677       if (!flg) break;
678 
679       for (i=0; i<n; ) {
680         /* Now identify the consecutive vals belonging to the same row */
681         for (j=i,rstart=row[j]; j<n; j++) {
682           if (row[j] != rstart) break;
683         }
684         if (j < n) ncols = j-i;
685         else       ncols = n-i;
686         /* Now assemble all these values with a single function call */
687         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,addv);CHKERRQ(ierr);
688 
689         i = j;
690       }
691     }
692     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
693   }
694   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
695   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
696 
697   /* determine if any processor has disassembled, if so we must
698      also disassemble ourselfs, in order that we may reassemble. */
699   /*
700      if nonzero structure of submatrix B cannot change then we know that
701      no processor disassembled thus we can skip this stuff
702   */
703   if (!((Mat_SeqAIJ*)aij->B->data)->nonew) {
704     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPIU_BOOL,MPI_PROD,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
705     if (mat->was_assembled && !other_disassembled) {
706       ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
707     }
708   }
709   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
710     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
711   }
712   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
713   ierr = MatSetOption(aij->B,MAT_CHECK_COMPRESSED_ROW,PETSC_FALSE);CHKERRQ(ierr);
714   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
715   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
716 
717   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
718 
719   aij->rowvalues = 0;
720 
721   /* used by MatAXPY() */
722   a->xtoy = 0; ((Mat_SeqAIJ*)aij->B->data)->xtoy = 0;   /* b->xtoy = 0 */
723   a->XtoY = 0; ((Mat_SeqAIJ*)aij->B->data)->XtoY = 0;   /* b->XtoY = 0 */
724 
725   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
726   if (a->inode.size) mat->ops->multdiagonalblock = MatMultDiagonalBlock_MPIAIJ;
727   PetscFunctionReturn(0);
728 }
729 
730 #undef __FUNCT__
731 #define __FUNCT__ "MatZeroEntries_MPIAIJ"
732 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
733 {
734   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
735   PetscErrorCode ierr;
736 
737   PetscFunctionBegin;
738   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
739   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
740   PetscFunctionReturn(0);
741 }
742 
743 #undef __FUNCT__
744 #define __FUNCT__ "MatZeroRows_MPIAIJ"
745 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
746 {
747   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
748   PetscErrorCode    ierr;
749   PetscMPIInt       size = l->size,imdex,n,rank = l->rank,tag = ((PetscObject)A)->tag,lastidx = -1;
750   PetscInt          i,*owners = A->rmap->range;
751   PetscInt          *nprocs,j,idx,nsends,row;
752   PetscInt          nmax,*svalues,*starts,*owner,nrecvs;
753   PetscInt          *rvalues,count,base,slen,*source;
754   PetscInt          *lens,*lrows,*values,rstart=A->rmap->rstart;
755   MPI_Comm          comm;
756   MPI_Request       *send_waits,*recv_waits;
757   MPI_Status        recv_status,*send_status;
758   const PetscScalar *xx;
759   PetscScalar       *bb;
760 #if defined(PETSC_DEBUG)
761   PetscBool found = PETSC_FALSE;
762 #endif
763 
764   PetscFunctionBegin;
765   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
766   /*  first count number of contributors to each processor */
767   ierr = PetscMalloc(2*size*sizeof(PetscInt),&nprocs);CHKERRQ(ierr);
768   ierr = PetscMemzero(nprocs,2*size*sizeof(PetscInt));CHKERRQ(ierr);
769   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&owner);CHKERRQ(ierr); /* see note*/
770   j    = 0;
771   for (i=0; i<N; i++) {
772     if (lastidx > (idx = rows[i])) j = 0;
773     lastidx = idx;
774     for (; j<size; j++) {
775       if (idx >= owners[j] && idx < owners[j+1]) {
776         nprocs[2*j]++;
777         nprocs[2*j+1] = 1;
778         owner[i]      = j;
779 #if defined(PETSC_DEBUG)
780         found = PETSC_TRUE;
781 #endif
782         break;
783       }
784     }
785 #if defined(PETSC_DEBUG)
786     if (!found) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index out of range");
787     found = PETSC_FALSE;
788 #endif
789   }
790   nsends = 0;
791   for (i=0; i<size; i++) nsends += nprocs[2*i+1];
792 
793   if (A->nooffproczerorows) {
794     if (nsends > 1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"You called MatSetOption(,MAT_NO_OFF_PROC_ZERO_ROWS,PETSC_TRUE) but set an off process zero row");
795     nrecvs = nsends;
796     nmax   = N;
797   } else {
798     /* inform other processors of number of messages and max length*/
799     ierr = PetscMaxSum(comm,nprocs,&nmax,&nrecvs);CHKERRQ(ierr);
800   }
801 
802   /* post receives:   */
803   ierr = PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(PetscInt),&rvalues);CHKERRQ(ierr);
804   ierr = PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);CHKERRQ(ierr);
805   for (i=0; i<nrecvs; i++) {
806     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPIU_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
807   }
808 
809   /* do sends:
810       1) starts[i] gives the starting index in svalues for stuff going to
811          the ith processor
812   */
813   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&svalues);CHKERRQ(ierr);
814   ierr = PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);CHKERRQ(ierr);
815   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&starts);CHKERRQ(ierr);
816 
817   starts[0] = 0;
818   for (i=1; i<size; i++) starts[i] = starts[i-1] + nprocs[2*i-2];
819   for (i=0; i<N; i++) svalues[starts[owner[i]]++] = rows[i];
820 
821   starts[0] = 0;
822   for (i=1; i<size+1; i++) starts[i] = starts[i-1] + nprocs[2*i-2];
823   count = 0;
824   for (i=0; i<size; i++) {
825     if (nprocs[2*i+1]) {
826       ierr = MPI_Isend(svalues+starts[i],nprocs[2*i],MPIU_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
827     }
828   }
829   ierr = PetscFree(starts);CHKERRQ(ierr);
830 
831   base = owners[rank];
832 
833   /*  wait on receives */
834   ierr  = PetscMalloc2(nrecvs,PetscInt,&lens,nrecvs,PetscInt,&source);CHKERRQ(ierr);
835   count = nrecvs; slen = 0;
836   while (count) {
837     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
838     /* unpack receives into our local space */
839     ierr = MPI_Get_count(&recv_status,MPIU_INT,&n);CHKERRQ(ierr);
840 
841     source[imdex] = recv_status.MPI_SOURCE;
842     lens[imdex]   = n;
843     slen         += n;
844     count--;
845   }
846   ierr = PetscFree(recv_waits);CHKERRQ(ierr);
847 
848   /* move the data into the send scatter */
849   ierr  = PetscMalloc((slen+1)*sizeof(PetscInt),&lrows);CHKERRQ(ierr);
850   count = 0;
851   for (i=0; i<nrecvs; i++) {
852     values = rvalues + i*nmax;
853     for (j=0; j<lens[i]; j++) lrows[count++] = values[j] - base;
854   }
855   ierr = PetscFree(rvalues);CHKERRQ(ierr);
856   ierr = PetscFree2(lens,source);CHKERRQ(ierr);
857   ierr = PetscFree(owner);CHKERRQ(ierr);
858   ierr = PetscFree(nprocs);CHKERRQ(ierr);
859 
860   /* fix right hand side if needed */
861   if (x && b) {
862     ierr = VecGetArrayRead(x,&xx);CHKERRQ(ierr);
863     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
864     for (i=0; i<slen; i++) bb[lrows[i]] = diag*xx[lrows[i]];
865     ierr = VecRestoreArrayRead(x,&xx);CHKERRQ(ierr);
866     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
867   }
868   /*
869         Zero the required rows. If the "diagonal block" of the matrix
870      is square and the user wishes to set the diagonal we use separate
871      code so that MatSetValues() is not called for each diagonal allocating
872      new memory, thus calling lots of mallocs and slowing things down.
873 
874   */
875   /* must zero l->B before l->A because the (diag) case below may put values into l->B*/
876   ierr = MatZeroRows(l->B,slen,lrows,0.0,0,0);CHKERRQ(ierr);
877   if ((diag != 0.0) && (l->A->rmap->N == l->A->cmap->N)) {
878     ierr = MatZeroRows(l->A,slen,lrows,diag,0,0);CHKERRQ(ierr);
879   } else if (diag != 0.0) {
880     ierr = MatZeroRows(l->A,slen,lrows,0.0,0,0);CHKERRQ(ierr);
881     if (((Mat_SeqAIJ*)l->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");
882     for (i = 0; i < slen; i++) {
883       row  = lrows[i] + rstart;
884       ierr = MatSetValues(A,1,&row,1,&row,&diag,INSERT_VALUES);CHKERRQ(ierr);
885     }
886     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
887     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
888   } else {
889     ierr = MatZeroRows(l->A,slen,lrows,0.0,0,0);CHKERRQ(ierr);
890   }
891   ierr = PetscFree(lrows);CHKERRQ(ierr);
892 
893   /* wait on sends */
894   if (nsends) {
895     ierr = PetscMalloc(nsends*sizeof(MPI_Status),&send_status);CHKERRQ(ierr);
896     ierr = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
897     ierr = PetscFree(send_status);CHKERRQ(ierr);
898   }
899   ierr = PetscFree(send_waits);CHKERRQ(ierr);
900   ierr = PetscFree(svalues);CHKERRQ(ierr);
901   PetscFunctionReturn(0);
902 }
903 
904 #undef __FUNCT__
905 #define __FUNCT__ "MatZeroRowsColumns_MPIAIJ"
906 PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
907 {
908   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
909   PetscErrorCode    ierr;
910   PetscMPIInt       size = l->size,imdex,n,rank = l->rank,tag = ((PetscObject)A)->tag,lastidx = -1;
911   PetscInt          i,*owners = A->rmap->range;
912   PetscInt          *nprocs,j,idx,nsends;
913   PetscInt          nmax,*svalues,*starts,*owner,nrecvs;
914   PetscInt          *rvalues,count,base,slen,*source;
915   PetscInt          *lens,*lrows,*values,m;
916   MPI_Comm          comm;
917   MPI_Request       *send_waits,*recv_waits;
918   MPI_Status        recv_status,*send_status;
919   const PetscScalar *xx;
920   PetscScalar       *bb,*mask;
921   Vec               xmask,lmask;
922   Mat_SeqAIJ        *aij = (Mat_SeqAIJ*)l->B->data;
923   const PetscInt    *aj, *ii,*ridx;
924   PetscScalar       *aa;
925 #if defined(PETSC_DEBUG)
926   PetscBool found = PETSC_FALSE;
927 #endif
928 
929   PetscFunctionBegin;
930   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
931   /*  first count number of contributors to each processor */
932   ierr = PetscMalloc(2*size*sizeof(PetscInt),&nprocs);CHKERRQ(ierr);
933   ierr = PetscMemzero(nprocs,2*size*sizeof(PetscInt));CHKERRQ(ierr);
934   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&owner);CHKERRQ(ierr); /* see note*/
935   j    = 0;
936   for (i=0; i<N; i++) {
937     if (lastidx > (idx = rows[i])) j = 0;
938     lastidx = idx;
939     for (; j<size; j++) {
940       if (idx >= owners[j] && idx < owners[j+1]) {
941         nprocs[2*j]++;
942         nprocs[2*j+1] = 1;
943         owner[i]      = j;
944 #if defined(PETSC_DEBUG)
945         found = PETSC_TRUE;
946 #endif
947         break;
948       }
949     }
950 #if defined(PETSC_DEBUG)
951     if (!found) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index out of range");
952     found = PETSC_FALSE;
953 #endif
954   }
955   nsends = 0;  for (i=0; i<size; i++) nsends += nprocs[2*i+1];
956 
957   /* inform other processors of number of messages and max length*/
958   ierr = PetscMaxSum(comm,nprocs,&nmax,&nrecvs);CHKERRQ(ierr);
959 
960   /* post receives:   */
961   ierr = PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(PetscInt),&rvalues);CHKERRQ(ierr);
962   ierr = PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);CHKERRQ(ierr);
963   for (i=0; i<nrecvs; i++) {
964     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPIU_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
965   }
966 
967   /* do sends:
968       1) starts[i] gives the starting index in svalues for stuff going to
969          the ith processor
970   */
971   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&svalues);CHKERRQ(ierr);
972   ierr = PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);CHKERRQ(ierr);
973   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&starts);CHKERRQ(ierr);
974 
975   starts[0] = 0;
976   for (i=1; i<size; i++) starts[i] = starts[i-1] + nprocs[2*i-2];
977   for (i=0; i<N; i++) svalues[starts[owner[i]]++] = rows[i];
978 
979   starts[0] = 0;
980   for (i=1; i<size+1; i++) starts[i] = starts[i-1] + nprocs[2*i-2];
981   count = 0;
982   for (i=0; i<size; i++) {
983     if (nprocs[2*i+1]) {
984       ierr = MPI_Isend(svalues+starts[i],nprocs[2*i],MPIU_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
985     }
986   }
987   ierr = PetscFree(starts);CHKERRQ(ierr);
988 
989   base = owners[rank];
990 
991   /*  wait on receives */
992   ierr  = PetscMalloc2(nrecvs,PetscInt,&lens,nrecvs,PetscInt,&source);CHKERRQ(ierr);
993   count = nrecvs; slen = 0;
994   while (count) {
995     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
996     /* unpack receives into our local space */
997     ierr = MPI_Get_count(&recv_status,MPIU_INT,&n);CHKERRQ(ierr);
998 
999     source[imdex] = recv_status.MPI_SOURCE;
1000     lens[imdex]   = n;
1001     slen         += n;
1002     count--;
1003   }
1004   ierr = PetscFree(recv_waits);CHKERRQ(ierr);
1005 
1006   /* move the data into the send scatter */
1007   ierr  = PetscMalloc((slen+1)*sizeof(PetscInt),&lrows);CHKERRQ(ierr);
1008   count = 0;
1009   for (i=0; i<nrecvs; i++) {
1010     values = rvalues + i*nmax;
1011     for (j=0; j<lens[i]; j++) lrows[count++] = values[j] - base;
1012   }
1013   ierr = PetscFree(rvalues);CHKERRQ(ierr);
1014   ierr = PetscFree2(lens,source);CHKERRQ(ierr);
1015   ierr = PetscFree(owner);CHKERRQ(ierr);
1016   ierr = PetscFree(nprocs);CHKERRQ(ierr);
1017   /* lrows are the local rows to be zeroed, slen is the number of local rows */
1018 
1019   /* zero diagonal part of matrix */
1020   ierr = MatZeroRowsColumns(l->A,slen,lrows,diag,x,b);CHKERRQ(ierr);
1021 
1022   /* handle off diagonal part of matrix */
1023   ierr = MatGetVecs(A,&xmask,NULL);CHKERRQ(ierr);
1024   ierr = VecDuplicate(l->lvec,&lmask);CHKERRQ(ierr);
1025   ierr = VecGetArray(xmask,&bb);CHKERRQ(ierr);
1026   for (i=0; i<slen; i++) bb[lrows[i]] = 1;
1027   ierr = VecRestoreArray(xmask,&bb);CHKERRQ(ierr);
1028   ierr = VecScatterBegin(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1029   ierr = VecScatterEnd(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1030   ierr = VecDestroy(&xmask);CHKERRQ(ierr);
1031   if (x) {
1032     ierr = VecScatterBegin(l->Mvctx,x,l->lvec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1033     ierr = VecScatterEnd(l->Mvctx,x,l->lvec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1034     ierr = VecGetArrayRead(l->lvec,&xx);CHKERRQ(ierr);
1035     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
1036   }
1037   ierr = VecGetArray(lmask,&mask);CHKERRQ(ierr);
1038 
1039   /* remove zeroed rows of off diagonal matrix */
1040   ii = aij->i;
1041   for (i=0; i<slen; i++) {
1042     ierr = PetscMemzero(aij->a + ii[lrows[i]],(ii[lrows[i]+1] - ii[lrows[i]])*sizeof(PetscScalar));CHKERRQ(ierr);
1043   }
1044 
1045   /* loop over all elements of off process part of matrix zeroing removed columns*/
1046   if (aij->compressedrow.use) {
1047     m    = aij->compressedrow.nrows;
1048     ii   = aij->compressedrow.i;
1049     ridx = aij->compressedrow.rindex;
1050     for (i=0; i<m; i++) {
1051       n  = ii[i+1] - ii[i];
1052       aj = aij->j + ii[i];
1053       aa = aij->a + ii[i];
1054 
1055       for (j=0; j<n; j++) {
1056         if (PetscAbsScalar(mask[*aj])) {
1057           if (b) bb[*ridx] -= *aa*xx[*aj];
1058           *aa = 0.0;
1059         }
1060         aa++;
1061         aj++;
1062       }
1063       ridx++;
1064     }
1065   } else { /* do not use compressed row format */
1066     m = l->B->rmap->n;
1067     for (i=0; i<m; i++) {
1068       n  = ii[i+1] - ii[i];
1069       aj = aij->j + ii[i];
1070       aa = aij->a + ii[i];
1071       for (j=0; j<n; j++) {
1072         if (PetscAbsScalar(mask[*aj])) {
1073           if (b) bb[i] -= *aa*xx[*aj];
1074           *aa = 0.0;
1075         }
1076         aa++;
1077         aj++;
1078       }
1079     }
1080   }
1081   if (x) {
1082     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
1083     ierr = VecRestoreArrayRead(l->lvec,&xx);CHKERRQ(ierr);
1084   }
1085   ierr = VecRestoreArray(lmask,&mask);CHKERRQ(ierr);
1086   ierr = VecDestroy(&lmask);CHKERRQ(ierr);
1087   ierr = PetscFree(lrows);CHKERRQ(ierr);
1088 
1089   /* wait on sends */
1090   if (nsends) {
1091     ierr = PetscMalloc(nsends*sizeof(MPI_Status),&send_status);CHKERRQ(ierr);
1092     ierr = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
1093     ierr = PetscFree(send_status);CHKERRQ(ierr);
1094   }
1095   ierr = PetscFree(send_waits);CHKERRQ(ierr);
1096   ierr = PetscFree(svalues);CHKERRQ(ierr);
1097   PetscFunctionReturn(0);
1098 }
1099 
1100 #undef __FUNCT__
1101 #define __FUNCT__ "MatMult_MPIAIJ"
1102 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
1103 {
1104   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1105   PetscErrorCode ierr;
1106   PetscInt       nt;
1107 
1108   PetscFunctionBegin;
1109   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
1110   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);
1111   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1112   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
1113   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1114   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
1115   PetscFunctionReturn(0);
1116 }
1117 
1118 #undef __FUNCT__
1119 #define __FUNCT__ "MatMultDiagonalBlock_MPIAIJ"
1120 PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A,Vec bb,Vec xx)
1121 {
1122   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1123   PetscErrorCode ierr;
1124 
1125   PetscFunctionBegin;
1126   ierr = MatMultDiagonalBlock(a->A,bb,xx);CHKERRQ(ierr);
1127   PetscFunctionReturn(0);
1128 }
1129 
1130 #undef __FUNCT__
1131 #define __FUNCT__ "MatMultAdd_MPIAIJ"
1132 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1133 {
1134   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1135   PetscErrorCode ierr;
1136 
1137   PetscFunctionBegin;
1138   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1139   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1140   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1141   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
1142   PetscFunctionReturn(0);
1143 }
1144 
1145 #undef __FUNCT__
1146 #define __FUNCT__ "MatMultTranspose_MPIAIJ"
1147 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
1148 {
1149   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1150   PetscErrorCode ierr;
1151   PetscBool      merged;
1152 
1153   PetscFunctionBegin;
1154   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
1155   /* do nondiagonal part */
1156   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1157   if (!merged) {
1158     /* send it on its way */
1159     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1160     /* do local part */
1161     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1162     /* receive remote parts: note this assumes the values are not actually */
1163     /* added in yy until the next line, */
1164     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1165   } else {
1166     /* do local part */
1167     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1168     /* send it on its way */
1169     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1170     /* values actually were received in the Begin() but we need to call this nop */
1171     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1172   }
1173   PetscFunctionReturn(0);
1174 }
1175 
1176 #undef __FUNCT__
1177 #define __FUNCT__ "MatIsTranspose_MPIAIJ"
1178 PetscErrorCode  MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscBool  *f)
1179 {
1180   MPI_Comm       comm;
1181   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ*) Amat->data, *Bij;
1182   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
1183   IS             Me,Notme;
1184   PetscErrorCode ierr;
1185   PetscInt       M,N,first,last,*notme,i;
1186   PetscMPIInt    size;
1187 
1188   PetscFunctionBegin;
1189   /* Easy test: symmetric diagonal block */
1190   Bij  = (Mat_MPIAIJ*) Bmat->data; Bdia = Bij->A;
1191   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
1192   if (!*f) PetscFunctionReturn(0);
1193   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1194   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1195   if (size == 1) PetscFunctionReturn(0);
1196 
1197   /* Hard test: off-diagonal block. This takes a MatGetSubMatrix. */
1198   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
1199   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
1200   ierr = PetscMalloc((N-last+first)*sizeof(PetscInt),&notme);CHKERRQ(ierr);
1201   for (i=0; i<first; i++) notme[i] = i;
1202   for (i=last; i<M; i++) notme[i-last+first] = i;
1203   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,PETSC_COPY_VALUES,&Notme);CHKERRQ(ierr);
1204   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
1205   ierr = MatGetSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
1206   Aoff = Aoffs[0];
1207   ierr = MatGetSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
1208   Boff = Boffs[0];
1209   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
1210   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
1211   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
1212   ierr = ISDestroy(&Me);CHKERRQ(ierr);
1213   ierr = ISDestroy(&Notme);CHKERRQ(ierr);
1214   ierr = PetscFree(notme);CHKERRQ(ierr);
1215   PetscFunctionReturn(0);
1216 }
1217 
1218 #undef __FUNCT__
1219 #define __FUNCT__ "MatMultTransposeAdd_MPIAIJ"
1220 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1221 {
1222   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1223   PetscErrorCode ierr;
1224 
1225   PetscFunctionBegin;
1226   /* do nondiagonal part */
1227   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1228   /* send it on its way */
1229   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1230   /* do local part */
1231   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1232   /* receive remote parts */
1233   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1234   PetscFunctionReturn(0);
1235 }
1236 
1237 /*
1238   This only works correctly for square matrices where the subblock A->A is the
1239    diagonal block
1240 */
1241 #undef __FUNCT__
1242 #define __FUNCT__ "MatGetDiagonal_MPIAIJ"
1243 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
1244 {
1245   PetscErrorCode ierr;
1246   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1247 
1248   PetscFunctionBegin;
1249   if (A->rmap->N != A->cmap->N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
1250   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");
1251   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1252   PetscFunctionReturn(0);
1253 }
1254 
1255 #undef __FUNCT__
1256 #define __FUNCT__ "MatScale_MPIAIJ"
1257 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
1258 {
1259   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1260   PetscErrorCode ierr;
1261 
1262   PetscFunctionBegin;
1263   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
1264   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
1265   PetscFunctionReturn(0);
1266 }
1267 
1268 #undef __FUNCT__
1269 #define __FUNCT__ "MatDestroy_MPIAIJ"
1270 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
1271 {
1272   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1273   PetscErrorCode ierr;
1274 
1275   PetscFunctionBegin;
1276 #if defined(PETSC_USE_LOG)
1277   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
1278 #endif
1279   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
1280   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
1281   ierr = MatDestroy(&aij->A);CHKERRQ(ierr);
1282   ierr = MatDestroy(&aij->B);CHKERRQ(ierr);
1283 #if defined(PETSC_USE_CTABLE)
1284   ierr = PetscTableDestroy(&aij->colmap);CHKERRQ(ierr);
1285 #else
1286   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
1287 #endif
1288   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
1289   ierr = VecDestroy(&aij->lvec);CHKERRQ(ierr);
1290   ierr = VecScatterDestroy(&aij->Mvctx);CHKERRQ(ierr);
1291   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
1292   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
1293   ierr = PetscFree(mat->data);CHKERRQ(ierr);
1294 
1295   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
1296   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C",NULL);CHKERRQ(ierr);
1297   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C",NULL);CHKERRQ(ierr);
1298   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatGetDiagonalBlock_C",NULL);CHKERRQ(ierr);
1299   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C",NULL);CHKERRQ(ierr);
1300   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C",NULL);CHKERRQ(ierr);
1301   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C",NULL);CHKERRQ(ierr);
1302   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C",NULL);CHKERRQ(ierr);
1303   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_mpisbaij_C",NULL);CHKERRQ(ierr);
1304   PetscFunctionReturn(0);
1305 }
1306 
1307 #undef __FUNCT__
1308 #define __FUNCT__ "MatView_MPIAIJ_Binary"
1309 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
1310 {
1311   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1312   Mat_SeqAIJ     *A   = (Mat_SeqAIJ*)aij->A->data;
1313   Mat_SeqAIJ     *B   = (Mat_SeqAIJ*)aij->B->data;
1314   PetscErrorCode ierr;
1315   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
1316   int            fd;
1317   PetscInt       nz,header[4],*row_lengths,*range=0,rlen,i;
1318   PetscInt       nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz;
1319   PetscScalar    *column_values;
1320   PetscInt       message_count,flowcontrolcount;
1321   FILE           *file;
1322 
1323   PetscFunctionBegin;
1324   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1325   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
1326   nz   = A->nz + B->nz;
1327   if (!rank) {
1328     header[0] = MAT_FILE_CLASSID;
1329     header[1] = mat->rmap->N;
1330     header[2] = mat->cmap->N;
1331 
1332     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1333     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
1334     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1335     /* get largest number of rows any processor has */
1336     rlen  = mat->rmap->n;
1337     range = mat->rmap->range;
1338     for (i=1; i<size; i++) rlen = PetscMax(rlen,range[i+1] - range[i]);
1339   } else {
1340     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1341     rlen = mat->rmap->n;
1342   }
1343 
1344   /* load up the local row counts */
1345   ierr = PetscMalloc((rlen+1)*sizeof(PetscInt),&row_lengths);CHKERRQ(ierr);
1346   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];
1347 
1348   /* store the row lengths to the file */
1349   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1350   if (!rank) {
1351     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1352     for (i=1; i<size; i++) {
1353       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1354       rlen = range[i+1] - range[i];
1355       ierr = MPIULong_Recv(row_lengths,rlen,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1356       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1357     }
1358     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1359   } else {
1360     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1361     ierr = MPIULong_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1362     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1363   }
1364   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
1365 
1366   /* load up the local column indices */
1367   nzmax = nz; /* th processor needs space a largest processor needs */
1368   ierr  = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1369   ierr  = PetscMalloc((nzmax+1)*sizeof(PetscInt),&column_indices);CHKERRQ(ierr);
1370   cnt   = 0;
1371   for (i=0; i<mat->rmap->n; i++) {
1372     for (j=B->i[i]; j<B->i[i+1]; j++) {
1373       if ((col = garray[B->j[j]]) > cstart) break;
1374       column_indices[cnt++] = col;
1375     }
1376     for (k=A->i[i]; k<A->i[i+1]; k++) column_indices[cnt++] = A->j[k] + cstart;
1377     for (; j<B->i[i+1]; j++) column_indices[cnt++] = garray[B->j[j]];
1378   }
1379   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);
1380 
1381   /* store the column indices to the file */
1382   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1383   if (!rank) {
1384     MPI_Status status;
1385     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1386     for (i=1; i<size; i++) {
1387       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1388       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1389       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1390       ierr = MPIULong_Recv(column_indices,rnz,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1391       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1392     }
1393     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1394   } else {
1395     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1396     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1397     ierr = MPIULong_Send(column_indices,nz,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1398     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1399   }
1400   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1401 
1402   /* load up the local column values */
1403   ierr = PetscMalloc((nzmax+1)*sizeof(PetscScalar),&column_values);CHKERRQ(ierr);
1404   cnt  = 0;
1405   for (i=0; i<mat->rmap->n; i++) {
1406     for (j=B->i[i]; j<B->i[i+1]; j++) {
1407       if (garray[B->j[j]] > cstart) break;
1408       column_values[cnt++] = B->a[j];
1409     }
1410     for (k=A->i[i]; k<A->i[i+1]; k++) column_values[cnt++] = A->a[k];
1411     for (; j<B->i[i+1]; j++) column_values[cnt++] = B->a[j];
1412   }
1413   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);
1414 
1415   /* store the column values to the file */
1416   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1417   if (!rank) {
1418     MPI_Status status;
1419     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1420     for (i=1; i<size; i++) {
1421       ierr = PetscViewerFlowControlStepMaster(viewer,i,&message_count,flowcontrolcount);CHKERRQ(ierr);
1422       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,PetscObjectComm((PetscObject)mat),&status);CHKERRQ(ierr);
1423       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1424       ierr = MPIULong_Recv(column_values,rnz,MPIU_SCALAR,i,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1425       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1426     }
1427     ierr = PetscViewerFlowControlEndMaster(viewer,&message_count);CHKERRQ(ierr);
1428   } else {
1429     ierr = PetscViewerFlowControlStepWorker(viewer,rank,&message_count);CHKERRQ(ierr);
1430     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1431     ierr = MPIULong_Send(column_values,nz,MPIU_SCALAR,0,tag,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
1432     ierr = PetscViewerFlowControlEndWorker(viewer,&message_count);CHKERRQ(ierr);
1433   }
1434   ierr = PetscFree(column_values);CHKERRQ(ierr);
1435 
1436   ierr = PetscViewerBinaryGetInfoPointer(viewer,&file);CHKERRQ(ierr);
1437   if (file) fprintf(file,"-matload_block_size %d\n",(int)mat->rmap->bs);
1438   PetscFunctionReturn(0);
1439 }
1440 
1441 #include <petscdraw.h>
1442 #undef __FUNCT__
1443 #define __FUNCT__ "MatView_MPIAIJ_ASCIIorDraworSocket"
1444 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1445 {
1446   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1447   PetscErrorCode    ierr;
1448   PetscMPIInt       rank = aij->rank,size = aij->size;
1449   PetscBool         isdraw,iascii,isbinary;
1450   PetscViewer       sviewer;
1451   PetscViewerFormat format;
1452 
1453   PetscFunctionBegin;
1454   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1455   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1456   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1457   if (iascii) {
1458     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1459     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1460       MatInfo   info;
1461       PetscBool inodes;
1462 
1463       ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&rank);CHKERRQ(ierr);
1464       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1465       ierr = MatInodeGetInodeSizes(aij->A,NULL,(PetscInt**)&inodes,NULL);CHKERRQ(ierr);
1466       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr);
1467       if (!inodes) {
1468         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1469                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1470       } else {
1471         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1472                                                   rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1473       }
1474       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1475       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1476       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1477       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1478       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1479       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr);
1480       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1481       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1482       PetscFunctionReturn(0);
1483     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1484       PetscInt inodecount,inodelimit,*inodes;
1485       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1486       if (inodes) {
1487         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1488       } else {
1489         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1490       }
1491       PetscFunctionReturn(0);
1492     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1493       PetscFunctionReturn(0);
1494     }
1495   } else if (isbinary) {
1496     if (size == 1) {
1497       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1498       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1499     } else {
1500       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1501     }
1502     PetscFunctionReturn(0);
1503   } else if (isdraw) {
1504     PetscDraw draw;
1505     PetscBool isnull;
1506     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1507     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1508   }
1509 
1510   if (size == 1) {
1511     ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1512     ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1513   } else {
1514     /* assemble the entire matrix onto first processor. */
1515     Mat        A;
1516     Mat_SeqAIJ *Aloc;
1517     PetscInt   M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1518     MatScalar  *a;
1519 
1520     if (mat->rmap->N > 1024) {
1521       PetscBool flg = PETSC_FALSE;
1522 
1523       ierr = PetscOptionsGetBool(((PetscObject) mat)->prefix, "-mat_ascii_output_large", &flg,NULL);CHKERRQ(ierr);
1524       if (!flg) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_OUTOFRANGE,"ASCII matrix output not allowed for matrices with more than 1024 rows, use binary format instead.\nYou can override this restriction using -mat_ascii_output_large.");
1525     }
1526 
1527     ierr = MatCreate(PetscObjectComm((PetscObject)mat),&A);CHKERRQ(ierr);
1528     if (!rank) {
1529       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1530     } else {
1531       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1532     }
1533     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1534     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1535     ierr = MatMPIAIJSetPreallocation(A,0,NULL,0,NULL);CHKERRQ(ierr);
1536     ierr = MatSetOption(A,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
1537     ierr = PetscLogObjectParent(mat,A);CHKERRQ(ierr);
1538 
1539     /* copy over the A part */
1540     Aloc = (Mat_SeqAIJ*)aij->A->data;
1541     m    = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1542     row  = mat->rmap->rstart;
1543     for (i=0; i<ai[m]; i++) aj[i] += mat->cmap->rstart;
1544     for (i=0; i<m; i++) {
1545       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1546       row++;
1547       a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1548     }
1549     aj = Aloc->j;
1550     for (i=0; i<ai[m]; i++) aj[i] -= mat->cmap->rstart;
1551 
1552     /* copy over the B part */
1553     Aloc = (Mat_SeqAIJ*)aij->B->data;
1554     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1555     row  = mat->rmap->rstart;
1556     ierr = PetscMalloc((ai[m]+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
1557     ct   = cols;
1558     for (i=0; i<ai[m]; i++) cols[i] = aij->garray[aj[i]];
1559     for (i=0; i<m; i++) {
1560       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1561       row++;
1562       a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1563     }
1564     ierr = PetscFree(ct);CHKERRQ(ierr);
1565     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1566     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1567     /*
1568        Everyone has to call to draw the matrix since the graphics waits are
1569        synchronized across all processors that share the PetscDraw object
1570     */
1571     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
1572     if (!rank) {
1573       ierr = PetscObjectSetName((PetscObject)((Mat_MPIAIJ*)(A->data))->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1574       /* Set the type name to MATMPIAIJ so that the correct type can be printed out by PetscObjectPrintClassNamePrefixType() in MatView_SeqAIJ_ASCII()*/
1575       PetscStrcpy(((PetscObject)((Mat_MPIAIJ*)(A->data))->A)->type_name,MATMPIAIJ);
1576       ierr = MatView(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1577     }
1578     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
1579     ierr = MatDestroy(&A);CHKERRQ(ierr);
1580   }
1581   PetscFunctionReturn(0);
1582 }
1583 
1584 #undef __FUNCT__
1585 #define __FUNCT__ "MatView_MPIAIJ"
1586 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1587 {
1588   PetscErrorCode ierr;
1589   PetscBool      iascii,isdraw,issocket,isbinary;
1590 
1591   PetscFunctionBegin;
1592   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1593   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1594   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1595   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSOCKET,&issocket);CHKERRQ(ierr);
1596   if (iascii || isdraw || isbinary || issocket) {
1597     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1598   }
1599   PetscFunctionReturn(0);
1600 }
1601 
1602 #undef __FUNCT__
1603 #define __FUNCT__ "MatSOR_MPIAIJ"
1604 PetscErrorCode MatSOR_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1605 {
1606   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1607   PetscErrorCode ierr;
1608   Vec            bb1 = 0;
1609   PetscBool      hasop;
1610 
1611   PetscFunctionBegin;
1612   if (flag == SOR_APPLY_UPPER) {
1613     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1614     PetscFunctionReturn(0);
1615   }
1616 
1617   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) {
1618     ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1619   }
1620 
1621   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP) {
1622     if (flag & SOR_ZERO_INITIAL_GUESS) {
1623       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1624       its--;
1625     }
1626 
1627     while (its--) {
1628       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1629       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1630 
1631       /* update rhs: bb1 = bb - B*x */
1632       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1633       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1634 
1635       /* local sweep */
1636       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1637     }
1638   } else if (flag & SOR_LOCAL_FORWARD_SWEEP) {
1639     if (flag & SOR_ZERO_INITIAL_GUESS) {
1640       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1641       its--;
1642     }
1643     while (its--) {
1644       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1645       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1646 
1647       /* update rhs: bb1 = bb - B*x */
1648       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1649       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1650 
1651       /* local sweep */
1652       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1653     }
1654   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP) {
1655     if (flag & SOR_ZERO_INITIAL_GUESS) {
1656       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1657       its--;
1658     }
1659     while (its--) {
1660       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1661       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1662 
1663       /* update rhs: bb1 = bb - B*x */
1664       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1665       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1666 
1667       /* local sweep */
1668       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1669     }
1670   } else if (flag & SOR_EISENSTAT) {
1671     Vec xx1;
1672 
1673     ierr = VecDuplicate(bb,&xx1);CHKERRQ(ierr);
1674     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP),fshift,lits,1,xx);CHKERRQ(ierr);
1675 
1676     ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1677     ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1678     if (!mat->diag) {
1679       ierr = MatGetVecs(matin,&mat->diag,NULL);CHKERRQ(ierr);
1680       ierr = MatGetDiagonal(matin,mat->diag);CHKERRQ(ierr);
1681     }
1682     ierr = MatHasOperation(matin,MATOP_MULT_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr);
1683     if (hasop) {
1684       ierr = MatMultDiagonalBlock(matin,xx,bb1);CHKERRQ(ierr);
1685     } else {
1686       ierr = VecPointwiseMult(bb1,mat->diag,xx);CHKERRQ(ierr);
1687     }
1688     ierr = VecAYPX(bb1,(omega-2.0)/omega,bb);CHKERRQ(ierr);
1689 
1690     ierr = MatMultAdd(mat->B,mat->lvec,bb1,bb1);CHKERRQ(ierr);
1691 
1692     /* local sweep */
1693     ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP),fshift,lits,1,xx1);CHKERRQ(ierr);
1694     ierr = VecAXPY(xx,1.0,xx1);CHKERRQ(ierr);
1695     ierr = VecDestroy(&xx1);CHKERRQ(ierr);
1696   } else SETERRQ(PetscObjectComm((PetscObject)matin),PETSC_ERR_SUP,"Parallel SOR not supported");
1697 
1698   ierr = VecDestroy(&bb1);CHKERRQ(ierr);
1699   PetscFunctionReturn(0);
1700 }
1701 
1702 #undef __FUNCT__
1703 #define __FUNCT__ "MatPermute_MPIAIJ"
1704 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1705 {
1706   Mat            aA,aB,Aperm;
1707   const PetscInt *rwant,*cwant,*gcols,*ai,*bi,*aj,*bj;
1708   PetscScalar    *aa,*ba;
1709   PetscInt       i,j,m,n,ng,anz,bnz,*dnnz,*onnz,*tdnnz,*tonnz,*rdest,*cdest,*work,*gcdest;
1710   PetscSF        rowsf,sf;
1711   IS             parcolp = NULL;
1712   PetscBool      done;
1713   PetscErrorCode ierr;
1714 
1715   PetscFunctionBegin;
1716   ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr);
1717   ierr = ISGetIndices(rowp,&rwant);CHKERRQ(ierr);
1718   ierr = ISGetIndices(colp,&cwant);CHKERRQ(ierr);
1719   ierr = PetscMalloc3(PetscMax(m,n),PetscInt,&work,m,PetscInt,&rdest,n,PetscInt,&cdest);CHKERRQ(ierr);
1720 
1721   /* Invert row permutation to find out where my rows should go */
1722   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&rowsf);CHKERRQ(ierr);
1723   ierr = PetscSFSetGraphLayout(rowsf,A->rmap,A->rmap->n,NULL,PETSC_OWN_POINTER,rwant);CHKERRQ(ierr);
1724   ierr = PetscSFSetFromOptions(rowsf);CHKERRQ(ierr);
1725   for (i=0; i<m; i++) work[i] = A->rmap->rstart + i;
1726   ierr = PetscSFReduceBegin(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1727   ierr = PetscSFReduceEnd(rowsf,MPIU_INT,work,rdest,MPIU_REPLACE);CHKERRQ(ierr);
1728 
1729   /* Invert column permutation to find out where my columns should go */
1730   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1731   ierr = PetscSFSetGraphLayout(sf,A->cmap,A->cmap->n,NULL,PETSC_OWN_POINTER,cwant);CHKERRQ(ierr);
1732   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1733   for (i=0; i<n; i++) work[i] = A->cmap->rstart + i;
1734   ierr = PetscSFReduceBegin(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1735   ierr = PetscSFReduceEnd(sf,MPIU_INT,work,cdest,MPIU_REPLACE);CHKERRQ(ierr);
1736   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1737 
1738   ierr = ISRestoreIndices(rowp,&rwant);CHKERRQ(ierr);
1739   ierr = ISRestoreIndices(colp,&cwant);CHKERRQ(ierr);
1740   ierr = MatMPIAIJGetSeqAIJ(A,&aA,&aB,&gcols);CHKERRQ(ierr);
1741 
1742   /* Find out where my gcols should go */
1743   ierr = MatGetSize(aB,NULL,&ng);CHKERRQ(ierr);
1744   ierr = PetscMalloc(ng*sizeof(PetscInt),&gcdest);CHKERRQ(ierr);
1745   ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
1746   ierr = PetscSFSetGraphLayout(sf,A->cmap,ng,NULL,PETSC_OWN_POINTER,gcols);CHKERRQ(ierr);
1747   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
1748   ierr = PetscSFBcastBegin(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1749   ierr = PetscSFBcastEnd(sf,MPIU_INT,cdest,gcdest);CHKERRQ(ierr);
1750   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
1751 
1752   ierr = PetscMalloc4(m,PetscInt,&dnnz,m,PetscInt,&onnz,m,PetscInt,&tdnnz,m,PetscInt,&tonnz);CHKERRQ(ierr);
1753   ierr = PetscMemzero(dnnz,m*sizeof(PetscInt));CHKERRQ(ierr);
1754   ierr = PetscMemzero(onnz,m*sizeof(PetscInt));CHKERRQ(ierr);
1755   ierr = MatGetRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1756   ierr = MatGetRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1757   for (i=0; i<m; i++) {
1758     PetscInt row = rdest[i],rowner;
1759     ierr = PetscLayoutFindOwner(A->rmap,row,&rowner);CHKERRQ(ierr);
1760     for (j=ai[i]; j<ai[i+1]; j++) {
1761       PetscInt cowner,col = cdest[aj[j]];
1762       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr); /* Could build an index for the columns to eliminate this search */
1763       if (rowner == cowner) dnnz[i]++;
1764       else onnz[i]++;
1765     }
1766     for (j=bi[i]; j<bi[i+1]; j++) {
1767       PetscInt cowner,col = gcdest[bj[j]];
1768       ierr = PetscLayoutFindOwner(A->cmap,col,&cowner);CHKERRQ(ierr);
1769       if (rowner == cowner) dnnz[i]++;
1770       else onnz[i]++;
1771     }
1772   }
1773   ierr = PetscMemzero(tdnnz,m*sizeof(PetscInt));CHKERRQ(ierr);
1774   ierr = PetscMemzero(tonnz,m*sizeof(PetscInt));CHKERRQ(ierr);
1775   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1776   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,dnnz,tdnnz);CHKERRQ(ierr);
1777   ierr = PetscSFBcastBegin(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1778   ierr = PetscSFBcastEnd(rowsf,MPIU_INT,onnz,tonnz);CHKERRQ(ierr);
1779   ierr = PetscSFDestroy(&rowsf);CHKERRQ(ierr);
1780 
1781   ierr = MatCreateAIJ(PetscObjectComm((PetscObject)A),A->rmap->n,A->cmap->n,A->rmap->N,A->cmap->N,0,tdnnz,0,tonnz,&Aperm);CHKERRQ(ierr);
1782   ierr = MatSeqAIJGetArray(aA,&aa);CHKERRQ(ierr);
1783   ierr = MatSeqAIJGetArray(aB,&ba);CHKERRQ(ierr);
1784   for (i=0; i<m; i++) {
1785     PetscInt *acols = dnnz,*bcols = onnz; /* Repurpose now-unneeded arrays */
1786     PetscInt rowlen;
1787     rowlen = ai[i+1] - ai[i];
1788     for (j=0; j<rowlen; j++) acols[j] = cdest[aj[ai[i]+j]];
1789     ierr   = MatSetValues(Aperm,1,&rdest[i],rowlen,acols,aa+ai[i],INSERT_VALUES);CHKERRQ(ierr);
1790     rowlen = bi[i+1] - bi[i];
1791     for (j=0; j<rowlen; j++) bcols[j] = gcdest[bj[bi[i]+j]];
1792     ierr = MatSetValues(Aperm,1,&rdest[i],rowlen,bcols,ba+bi[i],INSERT_VALUES);CHKERRQ(ierr);
1793   }
1794   ierr = MatAssemblyBegin(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1795   ierr = MatAssemblyEnd(Aperm,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1796   ierr = MatRestoreRowIJ(aA,0,PETSC_FALSE,PETSC_FALSE,&anz,&ai,&aj,&done);CHKERRQ(ierr);
1797   ierr = MatRestoreRowIJ(aB,0,PETSC_FALSE,PETSC_FALSE,&bnz,&bi,&bj,&done);CHKERRQ(ierr);
1798   ierr = MatSeqAIJRestoreArray(aA,&aa);CHKERRQ(ierr);
1799   ierr = MatSeqAIJRestoreArray(aB,&ba);CHKERRQ(ierr);
1800   ierr = PetscFree4(dnnz,onnz,tdnnz,tonnz);CHKERRQ(ierr);
1801   ierr = PetscFree3(work,rdest,cdest);CHKERRQ(ierr);
1802   ierr = PetscFree(gcdest);CHKERRQ(ierr);
1803   if (parcolp) {ierr = ISDestroy(&colp);CHKERRQ(ierr);}
1804   *B = Aperm;
1805   PetscFunctionReturn(0);
1806 }
1807 
1808 #undef __FUNCT__
1809 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1810 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1811 {
1812   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1813   Mat            A    = mat->A,B = mat->B;
1814   PetscErrorCode ierr;
1815   PetscReal      isend[5],irecv[5];
1816 
1817   PetscFunctionBegin;
1818   info->block_size = 1.0;
1819   ierr             = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1820 
1821   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1822   isend[3] = info->memory;  isend[4] = info->mallocs;
1823 
1824   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1825 
1826   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1827   isend[3] += info->memory;  isend[4] += info->mallocs;
1828   if (flag == MAT_LOCAL) {
1829     info->nz_used      = isend[0];
1830     info->nz_allocated = isend[1];
1831     info->nz_unneeded  = isend[2];
1832     info->memory       = isend[3];
1833     info->mallocs      = isend[4];
1834   } else if (flag == MAT_GLOBAL_MAX) {
1835     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1836 
1837     info->nz_used      = irecv[0];
1838     info->nz_allocated = irecv[1];
1839     info->nz_unneeded  = irecv[2];
1840     info->memory       = irecv[3];
1841     info->mallocs      = irecv[4];
1842   } else if (flag == MAT_GLOBAL_SUM) {
1843     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)matin));CHKERRQ(ierr);
1844 
1845     info->nz_used      = irecv[0];
1846     info->nz_allocated = irecv[1];
1847     info->nz_unneeded  = irecv[2];
1848     info->memory       = irecv[3];
1849     info->mallocs      = irecv[4];
1850   }
1851   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1852   info->fill_ratio_needed = 0;
1853   info->factor_mallocs    = 0;
1854   PetscFunctionReturn(0);
1855 }
1856 
1857 #undef __FUNCT__
1858 #define __FUNCT__ "MatSetOption_MPIAIJ"
1859 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscBool flg)
1860 {
1861   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1862   PetscErrorCode ierr;
1863 
1864   PetscFunctionBegin;
1865   switch (op) {
1866   case MAT_NEW_NONZERO_LOCATIONS:
1867   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1868   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1869   case MAT_KEEP_NONZERO_PATTERN:
1870   case MAT_NEW_NONZERO_LOCATION_ERR:
1871   case MAT_USE_INODES:
1872   case MAT_IGNORE_ZERO_ENTRIES:
1873     MatCheckPreallocated(A,1);
1874     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1875     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1876     break;
1877   case MAT_ROW_ORIENTED:
1878     a->roworiented = flg;
1879 
1880     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1881     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1882     break;
1883   case MAT_NEW_DIAGONALS:
1884     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1885     break;
1886   case MAT_IGNORE_OFF_PROC_ENTRIES:
1887     a->donotstash = flg;
1888     break;
1889   case MAT_SPD:
1890     A->spd_set = PETSC_TRUE;
1891     A->spd     = flg;
1892     if (flg) {
1893       A->symmetric                  = PETSC_TRUE;
1894       A->structurally_symmetric     = PETSC_TRUE;
1895       A->symmetric_set              = PETSC_TRUE;
1896       A->structurally_symmetric_set = PETSC_TRUE;
1897     }
1898     break;
1899   case MAT_SYMMETRIC:
1900     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1901     break;
1902   case MAT_STRUCTURALLY_SYMMETRIC:
1903     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1904     break;
1905   case MAT_HERMITIAN:
1906     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1907     break;
1908   case MAT_SYMMETRY_ETERNAL:
1909     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1910     break;
1911   default:
1912     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"unknown option %d",op);
1913   }
1914   PetscFunctionReturn(0);
1915 }
1916 
1917 #undef __FUNCT__
1918 #define __FUNCT__ "MatGetRow_MPIAIJ"
1919 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1920 {
1921   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1922   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1923   PetscErrorCode ierr;
1924   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1925   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1926   PetscInt       *cmap,*idx_p;
1927 
1928   PetscFunctionBegin;
1929   if (mat->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Already active");
1930   mat->getrowactive = PETSC_TRUE;
1931 
1932   if (!mat->rowvalues && (idx || v)) {
1933     /*
1934         allocate enough space to hold information from the longest row.
1935     */
1936     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1937     PetscInt   max = 1,tmp;
1938     for (i=0; i<matin->rmap->n; i++) {
1939       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1940       if (max < tmp) max = tmp;
1941     }
1942     ierr = PetscMalloc2(max,PetscScalar,&mat->rowvalues,max,PetscInt,&mat->rowindices);CHKERRQ(ierr);
1943   }
1944 
1945   if (row < rstart || row >= rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only local rows");
1946   lrow = row - rstart;
1947 
1948   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1949   if (!v)   {pvA = 0; pvB = 0;}
1950   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1951   ierr  = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1952   ierr  = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1953   nztot = nzA + nzB;
1954 
1955   cmap = mat->garray;
1956   if (v  || idx) {
1957     if (nztot) {
1958       /* Sort by increasing column numbers, assuming A and B already sorted */
1959       PetscInt imark = -1;
1960       if (v) {
1961         *v = v_p = mat->rowvalues;
1962         for (i=0; i<nzB; i++) {
1963           if (cmap[cworkB[i]] < cstart) v_p[i] = vworkB[i];
1964           else break;
1965         }
1966         imark = i;
1967         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1968         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1969       }
1970       if (idx) {
1971         *idx = idx_p = mat->rowindices;
1972         if (imark > -1) {
1973           for (i=0; i<imark; i++) {
1974             idx_p[i] = cmap[cworkB[i]];
1975           }
1976         } else {
1977           for (i=0; i<nzB; i++) {
1978             if (cmap[cworkB[i]] < cstart) idx_p[i] = cmap[cworkB[i]];
1979             else break;
1980           }
1981           imark = i;
1982         }
1983         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1984         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1985       }
1986     } else {
1987       if (idx) *idx = 0;
1988       if (v)   *v   = 0;
1989     }
1990   }
1991   *nz  = nztot;
1992   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1993   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1994   PetscFunctionReturn(0);
1995 }
1996 
1997 #undef __FUNCT__
1998 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1999 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
2000 {
2001   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
2002 
2003   PetscFunctionBegin;
2004   if (!aij->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
2005   aij->getrowactive = PETSC_FALSE;
2006   PetscFunctionReturn(0);
2007 }
2008 
2009 #undef __FUNCT__
2010 #define __FUNCT__ "MatNorm_MPIAIJ"
2011 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
2012 {
2013   Mat_MPIAIJ     *aij  = (Mat_MPIAIJ*)mat->data;
2014   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
2015   PetscErrorCode ierr;
2016   PetscInt       i,j,cstart = mat->cmap->rstart;
2017   PetscReal      sum = 0.0;
2018   MatScalar      *v;
2019 
2020   PetscFunctionBegin;
2021   if (aij->size == 1) {
2022     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
2023   } else {
2024     if (type == NORM_FROBENIUS) {
2025       v = amat->a;
2026       for (i=0; i<amat->nz; i++) {
2027         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
2028       }
2029       v = bmat->a;
2030       for (i=0; i<bmat->nz; i++) {
2031         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
2032       }
2033       ierr  = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
2034       *norm = PetscSqrtReal(*norm);
2035     } else if (type == NORM_1) { /* max column norm */
2036       PetscReal *tmp,*tmp2;
2037       PetscInt  *jj,*garray = aij->garray;
2038       ierr  = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp);CHKERRQ(ierr);
2039       ierr  = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp2);CHKERRQ(ierr);
2040       ierr  = PetscMemzero(tmp,mat->cmap->N*sizeof(PetscReal));CHKERRQ(ierr);
2041       *norm = 0.0;
2042       v     = amat->a; jj = amat->j;
2043       for (j=0; j<amat->nz; j++) {
2044         tmp[cstart + *jj++] += PetscAbsScalar(*v);  v++;
2045       }
2046       v = bmat->a; jj = bmat->j;
2047       for (j=0; j<bmat->nz; j++) {
2048         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
2049       }
2050       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
2051       for (j=0; j<mat->cmap->N; j++) {
2052         if (tmp2[j] > *norm) *norm = tmp2[j];
2053       }
2054       ierr = PetscFree(tmp);CHKERRQ(ierr);
2055       ierr = PetscFree(tmp2);CHKERRQ(ierr);
2056     } else if (type == NORM_INFINITY) { /* max row norm */
2057       PetscReal ntemp = 0.0;
2058       for (j=0; j<aij->A->rmap->n; j++) {
2059         v   = amat->a + amat->i[j];
2060         sum = 0.0;
2061         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
2062           sum += PetscAbsScalar(*v); v++;
2063         }
2064         v = bmat->a + bmat->i[j];
2065         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
2066           sum += PetscAbsScalar(*v); v++;
2067         }
2068         if (sum > ntemp) ntemp = sum;
2069       }
2070       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
2071     } else SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"No support for two norm");
2072   }
2073   PetscFunctionReturn(0);
2074 }
2075 
2076 #undef __FUNCT__
2077 #define __FUNCT__ "MatTranspose_MPIAIJ"
2078 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
2079 {
2080   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
2081   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
2082   PetscErrorCode ierr;
2083   PetscInt       M      = A->rmap->N,N = A->cmap->N,ma,na,mb,nb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i;
2084   PetscInt       cstart = A->cmap->rstart,ncol;
2085   Mat            B;
2086   MatScalar      *array;
2087 
2088   PetscFunctionBegin;
2089   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
2090 
2091   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n; nb = a->B->cmap->n;
2092   ai = Aloc->i; aj = Aloc->j;
2093   bi = Bloc->i; bj = Bloc->j;
2094   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
2095     PetscInt             *d_nnz,*g_nnz,*o_nnz;
2096     PetscSFNode          *oloc;
2097     PETSC_UNUSED PetscSF sf;
2098 
2099     ierr = PetscMalloc4(na,PetscInt,&d_nnz,na,PetscInt,&o_nnz,nb,PetscInt,&g_nnz,nb,PetscSFNode,&oloc);CHKERRQ(ierr);
2100     /* compute d_nnz for preallocation */
2101     ierr = PetscMemzero(d_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
2102     for (i=0; i<ai[ma]; i++) {
2103       d_nnz[aj[i]]++;
2104       aj[i] += cstart; /* global col index to be used by MatSetValues() */
2105     }
2106     /* compute local off-diagonal contributions */
2107     ierr = PetscMemzero(g_nnz,nb*sizeof(PetscInt));CHKERRQ(ierr);
2108     for (i=0; i<bi[ma]; i++) g_nnz[bj[i]]++;
2109     /* map those to global */
2110     ierr = PetscSFCreate(PetscObjectComm((PetscObject)A),&sf);CHKERRQ(ierr);
2111     ierr = PetscSFSetGraphLayout(sf,A->cmap,nb,NULL,PETSC_USE_POINTER,a->garray);CHKERRQ(ierr);
2112     ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
2113     ierr = PetscMemzero(o_nnz,na*sizeof(PetscInt));CHKERRQ(ierr);
2114     ierr = PetscSFReduceBegin(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
2115     ierr = PetscSFReduceEnd(sf,MPIU_INT,g_nnz,o_nnz,MPIU_SUM);CHKERRQ(ierr);
2116     ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
2117 
2118     ierr = MatCreate(PetscObjectComm((PetscObject)A),&B);CHKERRQ(ierr);
2119     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
2120     ierr = MatSetBlockSizes(B,A->cmap->bs,A->rmap->bs);CHKERRQ(ierr);
2121     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
2122     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
2123     ierr = PetscFree4(d_nnz,o_nnz,g_nnz,oloc);CHKERRQ(ierr);
2124   } else {
2125     B    = *matout;
2126     ierr = MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
2127     for (i=0; i<ai[ma]; i++) aj[i] += cstart; /* global col index to be used by MatSetValues() */
2128   }
2129 
2130   /* copy over the A part */
2131   array = Aloc->a;
2132   row   = A->rmap->rstart;
2133   for (i=0; i<ma; i++) {
2134     ncol = ai[i+1]-ai[i];
2135     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2136     row++;
2137     array += ncol; aj += ncol;
2138   }
2139   aj = Aloc->j;
2140   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
2141 
2142   /* copy over the B part */
2143   ierr  = PetscMalloc(bi[mb]*sizeof(PetscInt),&cols);CHKERRQ(ierr);
2144   ierr  = PetscMemzero(cols,bi[mb]*sizeof(PetscInt));CHKERRQ(ierr);
2145   array = Bloc->a;
2146   row   = A->rmap->rstart;
2147   for (i=0; i<bi[mb]; i++) cols[i] = a->garray[bj[i]];
2148   cols_tmp = cols;
2149   for (i=0; i<mb; i++) {
2150     ncol = bi[i+1]-bi[i];
2151     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2152     row++;
2153     array += ncol; cols_tmp += ncol;
2154   }
2155   ierr = PetscFree(cols);CHKERRQ(ierr);
2156 
2157   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2158   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2159   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
2160     *matout = B;
2161   } else {
2162     ierr = MatHeaderMerge(A,B);CHKERRQ(ierr);
2163   }
2164   PetscFunctionReturn(0);
2165 }
2166 
2167 #undef __FUNCT__
2168 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
2169 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
2170 {
2171   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2172   Mat            a    = aij->A,b = aij->B;
2173   PetscErrorCode ierr;
2174   PetscInt       s1,s2,s3;
2175 
2176   PetscFunctionBegin;
2177   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
2178   if (rr) {
2179     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
2180     if (s1!=s3) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
2181     /* Overlap communication with computation. */
2182     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2183   }
2184   if (ll) {
2185     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
2186     if (s1!=s2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
2187     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
2188   }
2189   /* scale  the diagonal block */
2190   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
2191 
2192   if (rr) {
2193     /* Do a scatter end and then right scale the off-diagonal block */
2194     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2195     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
2196   }
2197   PetscFunctionReturn(0);
2198 }
2199 
2200 #undef __FUNCT__
2201 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
2202 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2203 {
2204   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2205   PetscErrorCode ierr;
2206 
2207   PetscFunctionBegin;
2208   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
2209   PetscFunctionReturn(0);
2210 }
2211 
2212 #undef __FUNCT__
2213 #define __FUNCT__ "MatEqual_MPIAIJ"
2214 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscBool  *flag)
2215 {
2216   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
2217   Mat            a,b,c,d;
2218   PetscBool      flg;
2219   PetscErrorCode ierr;
2220 
2221   PetscFunctionBegin;
2222   a = matA->A; b = matA->B;
2223   c = matB->A; d = matB->B;
2224 
2225   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
2226   if (flg) {
2227     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
2228   }
2229   ierr = MPI_Allreduce(&flg,flag,1,MPIU_BOOL,MPI_LAND,PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
2230   PetscFunctionReturn(0);
2231 }
2232 
2233 #undef __FUNCT__
2234 #define __FUNCT__ "MatCopy_MPIAIJ"
2235 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
2236 {
2237   PetscErrorCode ierr;
2238   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2239   Mat_MPIAIJ     *b = (Mat_MPIAIJ*)B->data;
2240 
2241   PetscFunctionBegin;
2242   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2243   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2244     /* because of the column compression in the off-processor part of the matrix a->B,
2245        the number of columns in a->B and b->B may be different, hence we cannot call
2246        the MatCopy() directly on the two parts. If need be, we can provide a more
2247        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2248        then copying the submatrices */
2249     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
2250   } else {
2251     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
2252     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
2253   }
2254   PetscFunctionReturn(0);
2255 }
2256 
2257 #undef __FUNCT__
2258 #define __FUNCT__ "MatSetUp_MPIAIJ"
2259 PetscErrorCode MatSetUp_MPIAIJ(Mat A)
2260 {
2261   PetscErrorCode ierr;
2262 
2263   PetscFunctionBegin;
2264   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
2265   PetscFunctionReturn(0);
2266 }
2267 
2268 #undef __FUNCT__
2269 #define __FUNCT__ "MatAXPYGetPreallocation_MPIAIJ"
2270 /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2271 static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y,const PetscInt *yltog,Mat X,const PetscInt *xltog,PetscInt *nnz)
2272 {
2273   PetscInt       i,m=Y->rmap->N;
2274   Mat_SeqAIJ     *x  = (Mat_SeqAIJ*)X->data;
2275   Mat_SeqAIJ     *y  = (Mat_SeqAIJ*)Y->data;
2276   const PetscInt *xi = x->i,*yi = y->i;
2277 
2278   PetscFunctionBegin;
2279   /* Set the number of nonzeros in the new matrix */
2280   for (i=0; i<m; i++) {
2281     PetscInt       j,k,nzx = xi[i+1] - xi[i],nzy = yi[i+1] - yi[i];
2282     const PetscInt *xj = x->j+xi[i],*yj = y->j+yi[i];
2283     nnz[i] = 0;
2284     for (j=0,k=0; j<nzx; j++) {                   /* Point in X */
2285       for (; k<nzy && yltog[yj[k]]<xltog[xj[j]]; k++) nnz[i]++; /* Catch up to X */
2286       if (k<nzy && yltog[yj[k]]==xltog[xj[j]]) k++;             /* Skip duplicate */
2287       nnz[i]++;
2288     }
2289     for (; k<nzy; k++) nnz[i]++;
2290   }
2291   PetscFunctionReturn(0);
2292 }
2293 
2294 #undef __FUNCT__
2295 #define __FUNCT__ "MatAXPY_MPIAIJ"
2296 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
2297 {
2298   PetscErrorCode ierr;
2299   PetscInt       i;
2300   Mat_MPIAIJ     *xx = (Mat_MPIAIJ*)X->data,*yy = (Mat_MPIAIJ*)Y->data;
2301   PetscBLASInt   bnz,one=1;
2302   Mat_SeqAIJ     *x,*y;
2303 
2304   PetscFunctionBegin;
2305   if (str == SAME_NONZERO_PATTERN) {
2306     PetscScalar alpha = a;
2307     x    = (Mat_SeqAIJ*)xx->A->data;
2308     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2309     y    = (Mat_SeqAIJ*)yy->A->data;
2310     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2311     x    = (Mat_SeqAIJ*)xx->B->data;
2312     y    = (Mat_SeqAIJ*)yy->B->data;
2313     ierr = PetscBLASIntCast(x->nz,&bnz);CHKERRQ(ierr);
2314     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one));
2315   } else if (str == SUBSET_NONZERO_PATTERN) {
2316     ierr = MatAXPY_SeqAIJ(yy->A,a,xx->A,str);CHKERRQ(ierr);
2317 
2318     x = (Mat_SeqAIJ*)xx->B->data;
2319     y = (Mat_SeqAIJ*)yy->B->data;
2320     if (y->xtoy && y->XtoY != xx->B) {
2321       ierr = PetscFree(y->xtoy);CHKERRQ(ierr);
2322       ierr = MatDestroy(&y->XtoY);CHKERRQ(ierr);
2323     }
2324     if (!y->xtoy) { /* get xtoy */
2325       ierr    = MatAXPYGetxtoy_Private(xx->B->rmap->n,x->i,x->j,xx->garray,y->i,y->j,yy->garray,&y->xtoy);CHKERRQ(ierr);
2326       y->XtoY = xx->B;
2327       ierr    = PetscObjectReference((PetscObject)xx->B);CHKERRQ(ierr);
2328     }
2329     for (i=0; i<x->nz; i++) y->a[y->xtoy[i]] += a*(x->a[i]);
2330   } else {
2331     Mat      B;
2332     PetscInt *nnz_d,*nnz_o;
2333     ierr = PetscMalloc(yy->A->rmap->N*sizeof(PetscInt),&nnz_d);CHKERRQ(ierr);
2334     ierr = PetscMalloc(yy->B->rmap->N*sizeof(PetscInt),&nnz_o);CHKERRQ(ierr);
2335     ierr = MatCreate(PetscObjectComm((PetscObject)Y),&B);CHKERRQ(ierr);
2336     ierr = PetscObjectSetName((PetscObject)B,((PetscObject)Y)->name);CHKERRQ(ierr);
2337     ierr = MatSetSizes(B,Y->rmap->n,Y->cmap->n,Y->rmap->N,Y->cmap->N);CHKERRQ(ierr);
2338     ierr = MatSetBlockSizes(B,Y->rmap->bs,Y->cmap->bs);CHKERRQ(ierr);
2339     ierr = MatSetType(B,MATMPIAIJ);CHKERRQ(ierr);
2340     ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr);
2341     ierr = MatAXPYGetPreallocation_MPIAIJ(yy->B,yy->garray,xx->B,xx->garray,nnz_o);CHKERRQ(ierr);
2342     ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr);
2343     ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);
2344     ierr = MatHeaderReplace(Y,B);CHKERRQ(ierr);
2345     ierr = PetscFree(nnz_d);CHKERRQ(ierr);
2346     ierr = PetscFree(nnz_o);CHKERRQ(ierr);
2347   }
2348   PetscFunctionReturn(0);
2349 }
2350 
2351 extern PetscErrorCode  MatConjugate_SeqAIJ(Mat);
2352 
2353 #undef __FUNCT__
2354 #define __FUNCT__ "MatConjugate_MPIAIJ"
2355 PetscErrorCode  MatConjugate_MPIAIJ(Mat mat)
2356 {
2357 #if defined(PETSC_USE_COMPLEX)
2358   PetscErrorCode ierr;
2359   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2360 
2361   PetscFunctionBegin;
2362   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
2363   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
2364 #else
2365   PetscFunctionBegin;
2366 #endif
2367   PetscFunctionReturn(0);
2368 }
2369 
2370 #undef __FUNCT__
2371 #define __FUNCT__ "MatRealPart_MPIAIJ"
2372 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2373 {
2374   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2375   PetscErrorCode ierr;
2376 
2377   PetscFunctionBegin;
2378   ierr = MatRealPart(a->A);CHKERRQ(ierr);
2379   ierr = MatRealPart(a->B);CHKERRQ(ierr);
2380   PetscFunctionReturn(0);
2381 }
2382 
2383 #undef __FUNCT__
2384 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
2385 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2386 {
2387   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2388   PetscErrorCode ierr;
2389 
2390   PetscFunctionBegin;
2391   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
2392   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
2393   PetscFunctionReturn(0);
2394 }
2395 
2396 #if defined(PETSC_HAVE_PBGL)
2397 
2398 #include <boost/parallel/mpi/bsp_process_group.hpp>
2399 #include <boost/graph/distributed/ilu_default_graph.hpp>
2400 #include <boost/graph/distributed/ilu_0_block.hpp>
2401 #include <boost/graph/distributed/ilu_preconditioner.hpp>
2402 #include <boost/graph/distributed/petsc/interface.hpp>
2403 #include <boost/multi_array.hpp>
2404 #include <boost/parallel/distributed_property_map->hpp>
2405 
2406 #undef __FUNCT__
2407 #define __FUNCT__ "MatILUFactorSymbolic_MPIAIJ"
2408 /*
2409   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2410 */
2411 PetscErrorCode MatILUFactorSymbolic_MPIAIJ(Mat fact,Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
2412 {
2413   namespace petsc = boost::distributed::petsc;
2414 
2415   namespace graph_dist = boost::graph::distributed;
2416   using boost::graph::distributed::ilu_default::process_group_type;
2417   using boost::graph::ilu_permuted;
2418 
2419   PetscBool      row_identity, col_identity;
2420   PetscContainer c;
2421   PetscInt       m, n, M, N;
2422   PetscErrorCode ierr;
2423 
2424   PetscFunctionBegin;
2425   if (info->levels != 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only levels = 0 supported for parallel ilu");
2426   ierr = ISIdentity(isrow, &row_identity);CHKERRQ(ierr);
2427   ierr = ISIdentity(iscol, &col_identity);CHKERRQ(ierr);
2428   if (!row_identity || !col_identity) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Row and column permutations must be identity for parallel ILU");
2429 
2430   process_group_type pg;
2431   typedef graph_dist::ilu_default::ilu_level_graph_type lgraph_type;
2432   lgraph_type  *lgraph_p   = new lgraph_type(petsc::num_global_vertices(A), pg, petsc::matrix_distribution(A, pg));
2433   lgraph_type& level_graph = *lgraph_p;
2434   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2435 
2436   petsc::read_matrix(A, graph, get(boost::edge_weight, graph));
2437   ilu_permuted(level_graph);
2438 
2439   /* put together the new matrix */
2440   ierr = MatCreate(PetscObjectComm((PetscObject)A), fact);CHKERRQ(ierr);
2441   ierr = MatGetLocalSize(A, &m, &n);CHKERRQ(ierr);
2442   ierr = MatGetSize(A, &M, &N);CHKERRQ(ierr);
2443   ierr = MatSetSizes(fact, m, n, M, N);CHKERRQ(ierr);
2444   ierr = MatSetBlockSizes(fact,A->rmap->bs,A->cmap->bs);CHKERRQ(ierr);
2445   ierr = MatSetType(fact, ((PetscObject)A)->type_name);CHKERRQ(ierr);
2446   ierr = MatAssemblyBegin(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2447   ierr = MatAssemblyEnd(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2448 
2449   ierr = PetscContainerCreate(PetscObjectComm((PetscObject)A), &c);
2450   ierr = PetscContainerSetPointer(c, lgraph_p);
2451   ierr = PetscObjectCompose((PetscObject) (fact), "graph", (PetscObject) c);
2452   ierr = PetscContainerDestroy(&c);
2453   PetscFunctionReturn(0);
2454 }
2455 
2456 #undef __FUNCT__
2457 #define __FUNCT__ "MatLUFactorNumeric_MPIAIJ"
2458 PetscErrorCode MatLUFactorNumeric_MPIAIJ(Mat B,Mat A, const MatFactorInfo *info)
2459 {
2460   PetscFunctionBegin;
2461   PetscFunctionReturn(0);
2462 }
2463 
2464 #undef __FUNCT__
2465 #define __FUNCT__ "MatSolve_MPIAIJ"
2466 /*
2467   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2468 */
2469 PetscErrorCode MatSolve_MPIAIJ(Mat A, Vec b, Vec x)
2470 {
2471   namespace graph_dist = boost::graph::distributed;
2472 
2473   typedef graph_dist::ilu_default::ilu_level_graph_type lgraph_type;
2474   lgraph_type    *lgraph_p;
2475   PetscContainer c;
2476   PetscErrorCode ierr;
2477 
2478   PetscFunctionBegin;
2479   ierr = PetscObjectQuery((PetscObject) A, "graph", (PetscObject*) &c);CHKERRQ(ierr);
2480   ierr = PetscContainerGetPointer(c, (void**) &lgraph_p);CHKERRQ(ierr);
2481   ierr = VecCopy(b, x);CHKERRQ(ierr);
2482 
2483   PetscScalar *array_x;
2484   ierr = VecGetArray(x, &array_x);CHKERRQ(ierr);
2485   PetscInt sx;
2486   ierr = VecGetSize(x, &sx);CHKERRQ(ierr);
2487 
2488   PetscScalar *array_b;
2489   ierr = VecGetArray(b, &array_b);CHKERRQ(ierr);
2490   PetscInt sb;
2491   ierr = VecGetSize(b, &sb);CHKERRQ(ierr);
2492 
2493   lgraph_type& level_graph = *lgraph_p;
2494   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2495 
2496   typedef boost::multi_array_ref<PetscScalar, 1> array_ref_type;
2497   array_ref_type                                 ref_b(array_b, boost::extents[num_vertices(graph)]);
2498   array_ref_type                                 ref_x(array_x, boost::extents[num_vertices(graph)]);
2499 
2500   typedef boost::iterator_property_map<array_ref_type::iterator,
2501                                        boost::property_map<graph_dist::ilu_default::graph_type, boost::vertex_index_t>::type>  gvector_type;
2502   gvector_type                                   vector_b(ref_b.begin(), get(boost::vertex_index, graph));
2503   gvector_type                                   vector_x(ref_x.begin(), get(boost::vertex_index, graph));
2504 
2505   ilu_set_solve(*lgraph_p, vector_b, vector_x);
2506   PetscFunctionReturn(0);
2507 }
2508 #endif
2509 
2510 #undef __FUNCT__
2511 #define __FUNCT__ "MatDestroy_MatRedundant"
2512 PetscErrorCode MatDestroy_MatRedundant(Mat A)
2513 {
2514   PetscErrorCode ierr;
2515   Mat_Redundant  *redund;
2516   PetscInt       i;
2517   PetscMPIInt    size;
2518 
2519   PetscFunctionBegin;
2520   ierr = MPI_Comm_size(((PetscObject)A)->comm,&size);CHKERRQ(ierr);
2521   if (size == 1) {
2522     Mat_SeqAIJ *a = (Mat_SeqAIJ*)A->data;
2523     redund = a->redundant;
2524   } else {
2525     Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
2526     redund = a->redundant;
2527   }
2528   if (redund){
2529     if (redund->matseq) { /* via MatGetSubMatrices()  */
2530       ierr = ISDestroy(&redund->isrow);CHKERRQ(ierr);
2531       ierr = ISDestroy(&redund->iscol);CHKERRQ(ierr);
2532       ierr = MatDestroy(&redund->matseq[0]);CHKERRQ(ierr);
2533       ierr = PetscFree(redund->matseq);CHKERRQ(ierr);
2534     } else {
2535       ierr = PetscFree2(redund->send_rank,redund->recv_rank);CHKERRQ(ierr);
2536       ierr = PetscFree(redund->sbuf_j);CHKERRQ(ierr);
2537       ierr = PetscFree(redund->sbuf_a);CHKERRQ(ierr);
2538       for (i=0; i<redund->nrecvs; i++) {
2539         ierr = PetscFree(redund->rbuf_j[i]);CHKERRQ(ierr);
2540         ierr = PetscFree(redund->rbuf_a[i]);CHKERRQ(ierr);
2541       }
2542       ierr = PetscFree4(redund->sbuf_nz,redund->rbuf_nz,redund->rbuf_j,redund->rbuf_a);CHKERRQ(ierr);
2543     }
2544 
2545     if (redund->psubcomm) {
2546       ierr = PetscSubcommDestroy(&redund->psubcomm);CHKERRQ(ierr);
2547     }
2548     ierr = redund->Destroy(A);CHKERRQ(ierr);
2549     ierr = PetscFree(redund);CHKERRQ(ierr);
2550   }
2551   PetscFunctionReturn(0);
2552 }
2553 
2554 #undef __FUNCT__
2555 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ_psubcomm"
2556 PetscErrorCode MatGetRedundantMatrix_MPIAIJ_psubcomm(Mat mat,PetscInt nsubcomm,PetscSubcomm psubcomm,MatReuse reuse,Mat *matredundant)
2557 {
2558   PetscMPIInt    rank,size;
2559   MPI_Comm       comm,subcomm=psubcomm->comm;
2560   PetscErrorCode ierr;
2561   PetscInt       nsends=0,nrecvs=0,i,rownz_max=0,M=mat->rmap->N,N=mat->cmap->N;
2562   PetscMPIInt    *send_rank= NULL,*recv_rank=NULL,subrank,subsize;
2563   PetscInt       *rowrange = mat->rmap->range;
2564   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2565   Mat            A = aij->A,B=aij->B,C=*matredundant;
2566   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data;
2567   PetscScalar    *sbuf_a;
2568   PetscInt       nzlocal=a->nz+b->nz;
2569   PetscInt       j,cstart=mat->cmap->rstart,cend=mat->cmap->rend,row,nzA,nzB,ncols,*cworkA,*cworkB;
2570   PetscInt       rstart=mat->rmap->rstart,rend=mat->rmap->rend,*bmap=aij->garray;
2571   PetscInt       *cols,ctmp,lwrite,*rptr,l,*sbuf_j;
2572   MatScalar      *aworkA,*aworkB;
2573   PetscScalar    *vals;
2574   PetscMPIInt    tag1,tag2,tag3,imdex;
2575   MPI_Request    *s_waits1=NULL,*s_waits2=NULL,*s_waits3=NULL;
2576   MPI_Request    *r_waits1=NULL,*r_waits2=NULL,*r_waits3=NULL;
2577   MPI_Status     recv_status,*send_status;
2578   PetscInt       *sbuf_nz=NULL,*rbuf_nz=NULL,count;
2579   PetscInt       **rbuf_j=NULL;
2580   PetscScalar    **rbuf_a=NULL;
2581   Mat_Redundant  *redund =NULL;
2582 
2583   PetscFunctionBegin;
2584   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
2585   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2586   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2587   ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
2588   ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2589 
2590   if (reuse == MAT_REUSE_MATRIX) {
2591     if (M != mat->rmap->N || N != mat->cmap->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong global size");
2592     if (subsize == 1) {
2593       Mat_SeqAIJ *c = (Mat_SeqAIJ*)C->data;
2594       redund = c->redundant;
2595     } else {
2596       Mat_MPIAIJ *c = (Mat_MPIAIJ*)C->data;
2597       redund = c->redundant;
2598     }
2599     if (nzlocal != redund->nzlocal) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong nzlocal");
2600 
2601     nsends    = redund->nsends;
2602     nrecvs    = redund->nrecvs;
2603     send_rank = redund->send_rank;
2604     recv_rank = redund->recv_rank;
2605     sbuf_nz   = redund->sbuf_nz;
2606     rbuf_nz   = redund->rbuf_nz;
2607     sbuf_j    = redund->sbuf_j;
2608     sbuf_a    = redund->sbuf_a;
2609     rbuf_j    = redund->rbuf_j;
2610     rbuf_a    = redund->rbuf_a;
2611   }
2612 
2613   if (reuse == MAT_INITIAL_MATRIX) {
2614     PetscInt    nleftover,np_subcomm;
2615 
2616     /* get the destination processors' id send_rank, nsends and nrecvs */
2617     ierr = PetscMalloc2(size,PetscMPIInt,&send_rank,size,PetscMPIInt,&recv_rank);CHKERRQ(ierr);
2618 
2619     np_subcomm = size/nsubcomm;
2620     nleftover  = size - nsubcomm*np_subcomm;
2621 
2622     nsends = 0; nrecvs = 0;
2623     if (psubcomm->type == PETSC_SUBCOMM_INTERLACED) {
2624       /* -------------------------------------------*/
2625       for (i=0; i<size; i++) {
2626         if (subrank == i/nsubcomm && i != rank) { /* my_subrank == other's subrank */
2627           send_rank[nsends]   = i; nsends++;
2628           recv_rank[nrecvs++] = i;
2629           /* printf("[%d] send to and recv from [%d]\n",rank,i); */
2630         }
2631       }
2632       if (rank >= size - nleftover) { /* this proc is a leftover processor */
2633         i = size-nleftover-1;
2634         j = 0;
2635         while (j < nsubcomm - nleftover) {
2636           send_rank[nsends++] = i;
2637           i--; j++;
2638           /* printf("[%d] send to [%d]\n",rank,i); */
2639         }
2640       }
2641 
2642       if (nleftover && subsize == size/nsubcomm && subrank==subsize-1) { /* this proc recvs from leftover processors */
2643         for (i=0; i<nleftover; i++) {
2644           recv_rank[nrecvs++] = size-nleftover+i;
2645           /* printf("[%d] recv from [%d]\n",rank,i); */
2646         }
2647       }
2648     } else if (psubcomm->type == PETSC_SUBCOMM_CONTIGUOUS) {
2649       /* --------------------------------------------------*/
2650       PetscInt color,subcommstart;
2651       subcommstart=0;
2652       for (color=0; color<nsubcomm; color++) {
2653         if (psubcomm->color != color) {
2654           for (i=0; i<psubcomm->subsize[color]; i++) {
2655             if (subrank == i) { /* my_subrank == other's subrank */
2656               send_rank[nsends++] = subcommstart+i;
2657               recv_rank[nrecvs++] = subcommstart+i;
2658               /* printf("[%d] send to and recv from [%d]\n",rank,subcommstart+i); */
2659             }
2660           }
2661         }
2662         subcommstart += psubcomm->subsize[color];
2663       }
2664       if (nleftover && subrank == size/nsubcomm) { /* this proc is a leftover proc, send to subcomm that does not have leftover proc */
2665         subcommstart=0;
2666         for (color=0; color<nsubcomm; color++) {
2667           subcommstart += psubcomm->subsize[color];
2668           if (psubcomm->color == color) continue;
2669           if (psubcomm->subsize[color] == size/nsubcomm) { /* subcomm does not have leftover proc */
2670             send_rank[nsends++] = subcommstart -1; /* send to the last proc of subcomm[color] */
2671             /* printf("[%d] leftover send to [%d] \n",rank,subcommstart -1); */
2672           }
2673         }
2674       }
2675 
2676       if (nleftover && subsize == size/nsubcomm && subrank==subsize-1) { /* this proc recvs from leftover processors */
2677         subcommstart=0;
2678         for (color=0; color<nsubcomm; color++) {
2679           subcommstart += psubcomm->subsize[color];
2680           if (psubcomm->subsize[color] > size/nsubcomm) { /* subcomm has leftover proc */
2681             recv_rank[nrecvs++] = subcommstart -1; /* recv from the last proc of subcomm[color] */
2682             /* printf("[%d] recv from [%d]\n",rank,subcommstart -1); */
2683           }
2684         }
2685       }
2686     } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support for PetscSubcomm type %D",psubcomm->type);
2687 
2688     /* allocate sbuf_j, sbuf_a */
2689     i    = nzlocal + rowrange[rank+1] - rowrange[rank] + 2;
2690     ierr = PetscMalloc(i*sizeof(PetscInt),&sbuf_j);CHKERRQ(ierr);
2691     ierr = PetscMalloc((nzlocal+1)*sizeof(PetscScalar),&sbuf_a);CHKERRQ(ierr);
2692     /*
2693     ierr = PetscSynchronizedPrintf(comm,"[%d] nsends %d, nrecvs %d\n",rank,nsends,nrecvs);CHKERRQ(ierr);
2694     ierr = PetscSynchronizedFlush(comm);CHKERRQ(ierr);
2695      */
2696   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2697 
2698   /* copy mat's local entries into the buffers */
2699   if (reuse == MAT_INITIAL_MATRIX) {
2700     rownz_max = 0;
2701     rptr      = sbuf_j;
2702     cols      = sbuf_j + rend-rstart + 1;
2703     vals      = sbuf_a;
2704     rptr[0]   = 0;
2705     for (i=0; i<rend-rstart; i++) {
2706       row    = i + rstart;
2707       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2708       ncols  = nzA + nzB;
2709       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2710       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2711       /* load the column indices for this row into cols */
2712       lwrite = 0;
2713       for (l=0; l<nzB; l++) {
2714         if ((ctmp = bmap[cworkB[l]]) < cstart) {
2715           vals[lwrite]   = aworkB[l];
2716           cols[lwrite++] = ctmp;
2717         }
2718       }
2719       for (l=0; l<nzA; l++) {
2720         vals[lwrite]   = aworkA[l];
2721         cols[lwrite++] = cstart + cworkA[l];
2722       }
2723       for (l=0; l<nzB; l++) {
2724         if ((ctmp = bmap[cworkB[l]]) >= cend) {
2725           vals[lwrite]   = aworkB[l];
2726           cols[lwrite++] = ctmp;
2727         }
2728       }
2729       vals     += ncols;
2730       cols     += ncols;
2731       rptr[i+1] = rptr[i] + ncols;
2732       if (rownz_max < ncols) rownz_max = ncols;
2733     }
2734     if (rptr[rend-rstart] != a->nz + b->nz) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB, "rptr[%d] %d != %d + %d",rend-rstart,rptr[rend-rstart+1],a->nz,b->nz);
2735   } else { /* only copy matrix values into sbuf_a */
2736     rptr    = sbuf_j;
2737     vals    = sbuf_a;
2738     rptr[0] = 0;
2739     for (i=0; i<rend-rstart; i++) {
2740       row    = i + rstart;
2741       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2742       ncols  = nzA + nzB;
2743       cworkB = b->j + b->i[i];
2744       aworkA = a->a + a->i[i];
2745       aworkB = b->a + b->i[i];
2746       lwrite = 0;
2747       for (l=0; l<nzB; l++) {
2748         if ((ctmp = bmap[cworkB[l]]) < cstart) vals[lwrite++] = aworkB[l];
2749       }
2750       for (l=0; l<nzA; l++) vals[lwrite++] = aworkA[l];
2751       for (l=0; l<nzB; l++) {
2752         if ((ctmp = bmap[cworkB[l]]) >= cend) vals[lwrite++] = aworkB[l];
2753       }
2754       vals     += ncols;
2755       rptr[i+1] = rptr[i] + ncols;
2756     }
2757   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2758 
2759   /* send nzlocal to others, and recv other's nzlocal */
2760   /*--------------------------------------------------*/
2761   if (reuse == MAT_INITIAL_MATRIX) {
2762     ierr = PetscMalloc2(3*(nsends + nrecvs)+1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2763 
2764     s_waits2 = s_waits3 + nsends;
2765     s_waits1 = s_waits2 + nsends;
2766     r_waits1 = s_waits1 + nsends;
2767     r_waits2 = r_waits1 + nrecvs;
2768     r_waits3 = r_waits2 + nrecvs;
2769   } else {
2770     ierr = PetscMalloc2(nsends + nrecvs +1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2771 
2772     r_waits3 = s_waits3 + nsends;
2773   }
2774 
2775   ierr = PetscObjectGetNewTag((PetscObject)mat,&tag3);CHKERRQ(ierr);
2776   if (reuse == MAT_INITIAL_MATRIX) {
2777     /* get new tags to keep the communication clean */
2778     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag1);CHKERRQ(ierr);
2779     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag2);CHKERRQ(ierr);
2780     ierr = PetscMalloc4(nsends,PetscInt,&sbuf_nz,nrecvs,PetscInt,&rbuf_nz,nrecvs,PetscInt*,&rbuf_j,nrecvs,PetscScalar*,&rbuf_a);CHKERRQ(ierr);
2781 
2782     /* post receives of other's nzlocal */
2783     for (i=0; i<nrecvs; i++) {
2784       ierr = MPI_Irecv(rbuf_nz+i,1,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,r_waits1+i);CHKERRQ(ierr);
2785     }
2786     /* send nzlocal to others */
2787     for (i=0; i<nsends; i++) {
2788       sbuf_nz[i] = nzlocal;
2789       ierr       = MPI_Isend(sbuf_nz+i,1,MPIU_INT,send_rank[i],tag1,comm,s_waits1+i);CHKERRQ(ierr);
2790     }
2791     /* wait on receives of nzlocal; allocate space for rbuf_j, rbuf_a */
2792     count = nrecvs;
2793     while (count) {
2794       ierr = MPI_Waitany(nrecvs,r_waits1,&imdex,&recv_status);CHKERRQ(ierr);
2795 
2796       recv_rank[imdex] = recv_status.MPI_SOURCE;
2797       /* allocate rbuf_a and rbuf_j; then post receives of rbuf_j */
2798       ierr = PetscMalloc((rbuf_nz[imdex]+1)*sizeof(PetscScalar),&rbuf_a[imdex]);CHKERRQ(ierr);
2799 
2800       i = rowrange[recv_status.MPI_SOURCE+1] - rowrange[recv_status.MPI_SOURCE]; /* number of expected mat->i */
2801 
2802       rbuf_nz[imdex] += i + 2;
2803 
2804       ierr = PetscMalloc(rbuf_nz[imdex]*sizeof(PetscInt),&rbuf_j[imdex]);CHKERRQ(ierr);
2805       ierr = MPI_Irecv(rbuf_j[imdex],rbuf_nz[imdex],MPIU_INT,recv_status.MPI_SOURCE,tag2,comm,r_waits2+imdex);CHKERRQ(ierr);
2806       count--;
2807     }
2808     /* wait on sends of nzlocal */
2809     if (nsends) {ierr = MPI_Waitall(nsends,s_waits1,send_status);CHKERRQ(ierr);}
2810     /* send mat->i,j to others, and recv from other's */
2811     /*------------------------------------------------*/
2812     for (i=0; i<nsends; i++) {
2813       j    = nzlocal + rowrange[rank+1] - rowrange[rank] + 1;
2814       ierr = MPI_Isend(sbuf_j,j,MPIU_INT,send_rank[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
2815     }
2816     /* wait on receives of mat->i,j */
2817     /*------------------------------*/
2818     count = nrecvs;
2819     while (count) {
2820       ierr = MPI_Waitany(nrecvs,r_waits2,&imdex,&recv_status);CHKERRQ(ierr);
2821       if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2822       count--;
2823     }
2824     /* wait on sends of mat->i,j */
2825     /*---------------------------*/
2826     if (nsends) {
2827       ierr = MPI_Waitall(nsends,s_waits2,send_status);CHKERRQ(ierr);
2828     }
2829   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2830 
2831   /* post receives, send and receive mat->a */
2832   /*----------------------------------------*/
2833   for (imdex=0; imdex<nrecvs; imdex++) {
2834     ierr = MPI_Irecv(rbuf_a[imdex],rbuf_nz[imdex],MPIU_SCALAR,recv_rank[imdex],tag3,comm,r_waits3+imdex);CHKERRQ(ierr);
2835   }
2836   for (i=0; i<nsends; i++) {
2837     ierr = MPI_Isend(sbuf_a,nzlocal,MPIU_SCALAR,send_rank[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
2838   }
2839   count = nrecvs;
2840   while (count) {
2841     ierr = MPI_Waitany(nrecvs,r_waits3,&imdex,&recv_status);CHKERRQ(ierr);
2842     if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2843     count--;
2844   }
2845   if (nsends) {
2846     ierr = MPI_Waitall(nsends,s_waits3,send_status);CHKERRQ(ierr);
2847   }
2848 
2849   ierr = PetscFree2(s_waits3,send_status);CHKERRQ(ierr);
2850 
2851   /* create redundant matrix */
2852   /*-------------------------*/
2853   if (reuse == MAT_INITIAL_MATRIX) {
2854     const PetscInt *range;
2855     PetscInt       rstart_sub,rend_sub,mloc_sub;
2856 
2857     /* compute rownz_max for preallocation */
2858     for (imdex=0; imdex<nrecvs; imdex++) {
2859       j    = rowrange[recv_rank[imdex]+1] - rowrange[recv_rank[imdex]];
2860       rptr = rbuf_j[imdex];
2861       for (i=0; i<j; i++) {
2862         ncols = rptr[i+1] - rptr[i];
2863         if (rownz_max < ncols) rownz_max = ncols;
2864       }
2865     }
2866 
2867     ierr = MatCreate(subcomm,&C);CHKERRQ(ierr);
2868 
2869     /* get local size of redundant matrix
2870        - mloc_sub is chosen for PETSC_SUBCOMM_INTERLACED, works for other types, but may not efficient! */
2871     ierr = MatGetOwnershipRanges(mat,&range);CHKERRQ(ierr);
2872     rstart_sub = range[nsubcomm*subrank];
2873     if (subrank+1 < subsize) { /* not the last proc in subcomm */
2874       rend_sub = range[nsubcomm*(subrank+1)];
2875     } else {
2876       rend_sub = mat->rmap->N;
2877     }
2878     mloc_sub = rend_sub - rstart_sub;
2879 
2880     if (M == N) {
2881       ierr = MatSetSizes(C,mloc_sub,mloc_sub,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
2882     } else { /* non-square matrix */
2883       ierr = MatSetSizes(C,mloc_sub,PETSC_DECIDE,PETSC_DECIDE,mat->cmap->N);CHKERRQ(ierr);
2884     }
2885     ierr = MatSetBlockSizes(C,mat->rmap->bs,mat->cmap->bs);CHKERRQ(ierr);
2886     ierr = MatSetFromOptions(C);CHKERRQ(ierr);
2887     ierr = MatSeqAIJSetPreallocation(C,rownz_max,NULL);CHKERRQ(ierr);
2888     ierr = MatMPIAIJSetPreallocation(C,rownz_max,NULL,rownz_max,NULL);CHKERRQ(ierr);
2889   } else {
2890     C = *matredundant;
2891   }
2892 
2893   /* insert local matrix entries */
2894   rptr = sbuf_j;
2895   cols = sbuf_j + rend-rstart + 1;
2896   vals = sbuf_a;
2897   for (i=0; i<rend-rstart; i++) {
2898     row   = i + rstart;
2899     ncols = rptr[i+1] - rptr[i];
2900     ierr  = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2901     vals += ncols;
2902     cols += ncols;
2903   }
2904   /* insert received matrix entries */
2905   for (imdex=0; imdex<nrecvs; imdex++) {
2906     rstart = rowrange[recv_rank[imdex]];
2907     rend   = rowrange[recv_rank[imdex]+1];
2908     /* printf("[%d] insert rows %d - %d\n",rank,rstart,rend-1); */
2909     rptr   = rbuf_j[imdex];
2910     cols   = rbuf_j[imdex] + rend-rstart + 1;
2911     vals   = rbuf_a[imdex];
2912     for (i=0; i<rend-rstart; i++) {
2913       row   = i + rstart;
2914       ncols = rptr[i+1] - rptr[i];
2915       ierr  = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2916       vals += ncols;
2917       cols += ncols;
2918     }
2919   }
2920   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2921   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2922 
2923   if (reuse == MAT_INITIAL_MATRIX) {
2924     *matredundant = C;
2925 
2926     /* create a supporting struct and attach it to C for reuse */
2927     ierr = PetscNewLog(C,Mat_Redundant,&redund);CHKERRQ(ierr);
2928     if (subsize == 1) {
2929       Mat_SeqAIJ *c = (Mat_SeqAIJ*)C->data;
2930       c->redundant = redund;
2931     } else {
2932       Mat_MPIAIJ *c = (Mat_MPIAIJ*)C->data;
2933       c->redundant = redund;
2934     }
2935 
2936     redund->nzlocal   = nzlocal;
2937     redund->nsends    = nsends;
2938     redund->nrecvs    = nrecvs;
2939     redund->send_rank = send_rank;
2940     redund->recv_rank = recv_rank;
2941     redund->sbuf_nz   = sbuf_nz;
2942     redund->rbuf_nz   = rbuf_nz;
2943     redund->sbuf_j    = sbuf_j;
2944     redund->sbuf_a    = sbuf_a;
2945     redund->rbuf_j    = rbuf_j;
2946     redund->rbuf_a    = rbuf_a;
2947     redund->psubcomm  = NULL;
2948 
2949     redund->Destroy = C->ops->destroy;
2950     C->ops->destroy = MatDestroy_MatRedundant;
2951   }
2952   PetscFunctionReturn(0);
2953 }
2954 
2955 #undef __FUNCT__
2956 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ"
2957 PetscErrorCode MatGetRedundantMatrix_MPIAIJ(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,PetscSubcomm psubcomm,MatReuse reuse,Mat *matredundant)
2958 {
2959   PetscErrorCode ierr;
2960   MPI_Comm       comm;
2961   PetscMPIInt    size,subsize;
2962   PetscInt       mloc_sub,rstart,rend,M=mat->rmap->N,N=mat->cmap->N;
2963   Mat_Redundant  *redund =NULL;
2964   PetscSubcomm   psubcomm_in=psubcomm;
2965   MPI_Comm       subcomm_in=subcomm;
2966 
2967   PetscFunctionBegin;
2968   if (subcomm_in == MPI_COMM_NULL) { /* use psubcomm */
2969     if (reuse ==  MAT_INITIAL_MATRIX) {
2970       if (psubcomm_in == NULL) { /* user does not provide psubcomm, create it here */
2971         ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
2972         ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2973         ierr = PetscSubcommCreate(comm,&psubcomm);CHKERRQ(ierr);
2974         ierr = PetscSubcommSetNumber(psubcomm,nsubcomm);CHKERRQ(ierr);
2975         ierr = PetscSubcommSetType(psubcomm,PETSC_SUBCOMM_CONTIGUOUS);CHKERRQ(ierr);
2976         ierr = PetscSubcommSetFromOptions(psubcomm);CHKERRQ(ierr);
2977       }
2978       subcomm = psubcomm->comm;
2979       ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2980     } else { /* retrieve psubcomm */
2981       if (psubcomm_in == NULL) { /* user does not provide psubcomm */
2982         ierr = PetscObjectGetComm((PetscObject)(*matredundant),&subcomm);CHKERRQ(ierr);
2983         ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2984         if (subsize == 1) {
2985           Mat_SeqAIJ *c = (Mat_SeqAIJ*)(*matredundant)->data;
2986           psubcomm = c->redundant->psubcomm;
2987         } else {
2988           Mat_MPIAIJ *c = (Mat_MPIAIJ*)(*matredundant)->data;
2989           psubcomm = c->redundant->psubcomm;
2990         }
2991       } else { /* use psubcomm_in */
2992         subcomm = psubcomm_in->comm;
2993         ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2994       }
2995     }
2996   }
2997 
2998   if (subcomm_in==NULL && psubcomm->type == PETSC_SUBCOMM_INTERLACED) {
2999      ierr = MatGetRedundantMatrix_MPIAIJ_psubcomm(mat,nsubcomm,psubcomm,reuse,matredundant);CHKERRQ(ierr);
3000   } else {
3001     /* via MatGetSubMatrices() */
3002     Mat  *matseq;
3003     IS   isrow,iscol;
3004 
3005     if (reuse == MAT_INITIAL_MATRIX) {
3006       /* create a local sequential matrix matseq[0] */
3007       mloc_sub = PETSC_DECIDE;
3008       ierr = PetscSplitOwnership(subcomm,&mloc_sub,&M);CHKERRQ(ierr);
3009       ierr = MPI_Scan(&mloc_sub,&rend,1,MPIU_INT,MPI_SUM,subcomm);CHKERRQ(ierr);
3010       rstart = rend - mloc_sub;
3011       ierr = ISCreateStride(PETSC_COMM_SELF,mloc_sub,rstart,1,&isrow);CHKERRQ(ierr);
3012       ierr = ISCreateStride(PETSC_COMM_SELF,N,0,1,&iscol);CHKERRQ(ierr);
3013     } else { /* reuse == MAT_REUSE_MATRIX */
3014       if (subsize == 1) {
3015         Mat_SeqAIJ *c = (Mat_SeqAIJ*)(*matredundant)->data;
3016         redund = c->redundant;
3017       } else {
3018         Mat_MPIAIJ *c = (Mat_MPIAIJ*)(*matredundant)->data;
3019         redund = c->redundant;
3020       }
3021 
3022       isrow  = redund->isrow;
3023       iscol  = redund->iscol;
3024       matseq = redund->matseq;
3025     }
3026 
3027     ierr = MatGetSubMatrices(mat,1,&isrow,&iscol,reuse,&matseq);CHKERRQ(ierr);
3028     ierr = MatCreateMPIAIJConcatenateSeqAIJ(subcomm,matseq[0],PETSC_DECIDE,reuse,matredundant);CHKERRQ(ierr);
3029 
3030     if (reuse == MAT_INITIAL_MATRIX) {
3031       /* create a supporting struct and attach it to C for reuse */
3032       ierr = PetscNewLog(*matredundant,Mat_Redundant,&redund);CHKERRQ(ierr);
3033       if (subsize == 1) {
3034         Mat_SeqAIJ *c = (Mat_SeqAIJ*)(*matredundant)->data;
3035         c->redundant = redund;
3036       } else {
3037         Mat_MPIAIJ *c = (Mat_MPIAIJ*)(*matredundant)->data;
3038         c->redundant = redund;
3039       }
3040       redund->isrow    = isrow;
3041       redund->iscol    = iscol;
3042       redund->matseq   = matseq;
3043       redund->psubcomm = NULL;
3044       redund->Destroy               = (*matredundant)->ops->destroy;
3045       (*matredundant)->ops->destroy = MatDestroy_MatRedundant;
3046     }
3047   }
3048 
3049   if (psubcomm && psubcomm_in==NULL) {
3050     /* if psubcomm is created in this routine, free it in MatDestroy_MatRedundant() */
3051     ierr = MPI_Comm_size(psubcomm->comm,&subsize);CHKERRQ(ierr);
3052     if (subsize == 1) {
3053       Mat_SeqAIJ *c = (Mat_SeqAIJ*)(*matredundant)->data;
3054       c->redundant->psubcomm = psubcomm;
3055     } else {
3056       Mat_MPIAIJ *c = (Mat_MPIAIJ*)(*matredundant)->data;
3057       c->redundant->psubcomm = psubcomm ;
3058     }
3059   }
3060   PetscFunctionReturn(0);
3061 }
3062 
3063 #undef __FUNCT__
3064 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
3065 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
3066 {
3067   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3068   PetscErrorCode ierr;
3069   PetscInt       i,*idxb = 0;
3070   PetscScalar    *va,*vb;
3071   Vec            vtmp;
3072 
3073   PetscFunctionBegin;
3074   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
3075   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
3076   if (idx) {
3077     for (i=0; i<A->rmap->n; i++) {
3078       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
3079     }
3080   }
3081 
3082   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
3083   if (idx) {
3084     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
3085   }
3086   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
3087   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
3088 
3089   for (i=0; i<A->rmap->n; i++) {
3090     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
3091       va[i] = vb[i];
3092       if (idx) idx[i] = a->garray[idxb[i]];
3093     }
3094   }
3095 
3096   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
3097   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
3098   ierr = PetscFree(idxb);CHKERRQ(ierr);
3099   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
3100   PetscFunctionReturn(0);
3101 }
3102 
3103 #undef __FUNCT__
3104 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
3105 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
3106 {
3107   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3108   PetscErrorCode ierr;
3109   PetscInt       i,*idxb = 0;
3110   PetscScalar    *va,*vb;
3111   Vec            vtmp;
3112 
3113   PetscFunctionBegin;
3114   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
3115   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
3116   if (idx) {
3117     for (i=0; i<A->cmap->n; i++) {
3118       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
3119     }
3120   }
3121 
3122   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
3123   if (idx) {
3124     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
3125   }
3126   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
3127   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
3128 
3129   for (i=0; i<A->rmap->n; i++) {
3130     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
3131       va[i] = vb[i];
3132       if (idx) idx[i] = a->garray[idxb[i]];
3133     }
3134   }
3135 
3136   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
3137   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
3138   ierr = PetscFree(idxb);CHKERRQ(ierr);
3139   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
3140   PetscFunctionReturn(0);
3141 }
3142 
3143 #undef __FUNCT__
3144 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
3145 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
3146 {
3147   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
3148   PetscInt       n      = A->rmap->n;
3149   PetscInt       cstart = A->cmap->rstart;
3150   PetscInt       *cmap  = mat->garray;
3151   PetscInt       *diagIdx, *offdiagIdx;
3152   Vec            diagV, offdiagV;
3153   PetscScalar    *a, *diagA, *offdiagA;
3154   PetscInt       r;
3155   PetscErrorCode ierr;
3156 
3157   PetscFunctionBegin;
3158   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
3159   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &diagV);CHKERRQ(ierr);
3160   ierr = VecCreateSeq(PetscObjectComm((PetscObject)A), n, &offdiagV);CHKERRQ(ierr);
3161   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
3162   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
3163   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
3164   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
3165   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
3166   for (r = 0; r < n; ++r) {
3167     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
3168       a[r]   = diagA[r];
3169       idx[r] = cstart + diagIdx[r];
3170     } else {
3171       a[r]   = offdiagA[r];
3172       idx[r] = cmap[offdiagIdx[r]];
3173     }
3174   }
3175   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
3176   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
3177   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
3178   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
3179   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
3180   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
3181   PetscFunctionReturn(0);
3182 }
3183 
3184 #undef __FUNCT__
3185 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
3186 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
3187 {
3188   Mat_MPIAIJ     *mat   = (Mat_MPIAIJ*) A->data;
3189   PetscInt       n      = A->rmap->n;
3190   PetscInt       cstart = A->cmap->rstart;
3191   PetscInt       *cmap  = mat->garray;
3192   PetscInt       *diagIdx, *offdiagIdx;
3193   Vec            diagV, offdiagV;
3194   PetscScalar    *a, *diagA, *offdiagA;
3195   PetscInt       r;
3196   PetscErrorCode ierr;
3197 
3198   PetscFunctionBegin;
3199   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
3200   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &diagV);CHKERRQ(ierr);
3201   ierr = VecCreateSeq(PETSC_COMM_SELF, n, &offdiagV);CHKERRQ(ierr);
3202   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
3203   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
3204   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
3205   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
3206   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
3207   for (r = 0; r < n; ++r) {
3208     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
3209       a[r]   = diagA[r];
3210       idx[r] = cstart + diagIdx[r];
3211     } else {
3212       a[r]   = offdiagA[r];
3213       idx[r] = cmap[offdiagIdx[r]];
3214     }
3215   }
3216   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
3217   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
3218   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
3219   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
3220   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
3221   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
3222   PetscFunctionReturn(0);
3223 }
3224 
3225 #undef __FUNCT__
3226 #define __FUNCT__ "MatGetSeqNonzeroStructure_MPIAIJ"
3227 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
3228 {
3229   PetscErrorCode ierr;
3230   Mat            *dummy;
3231 
3232   PetscFunctionBegin;
3233   ierr    = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
3234   *newmat = *dummy;
3235   ierr    = PetscFree(dummy);CHKERRQ(ierr);
3236   PetscFunctionReturn(0);
3237 }
3238 
3239 extern PetscErrorCode  MatFDColoringApply_AIJ(Mat,MatFDColoring,Vec,MatStructure*,void*);
3240 
3241 #undef __FUNCT__
3242 #define __FUNCT__ "MatInvertBlockDiagonal_MPIAIJ"
3243 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
3244 {
3245   Mat_MPIAIJ     *a = (Mat_MPIAIJ*) A->data;
3246   PetscErrorCode ierr;
3247 
3248   PetscFunctionBegin;
3249   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
3250   PetscFunctionReturn(0);
3251 }
3252 
3253 #undef __FUNCT__
3254 #define __FUNCT__ "MatSetRandom_MPIAIJ"
3255 static PetscErrorCode  MatSetRandom_MPIAIJ(Mat x,PetscRandom rctx)
3256 {
3257   PetscErrorCode ierr;
3258   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)x->data;
3259 
3260   PetscFunctionBegin;
3261   ierr = MatSetRandom(aij->A,rctx);CHKERRQ(ierr);
3262   ierr = MatSetRandom(aij->B,rctx);CHKERRQ(ierr);
3263   ierr = MatAssemblyBegin(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3264   ierr = MatAssemblyEnd(x,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3265   PetscFunctionReturn(0);
3266 }
3267 
3268 /* -------------------------------------------------------------------*/
3269 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
3270                                        MatGetRow_MPIAIJ,
3271                                        MatRestoreRow_MPIAIJ,
3272                                        MatMult_MPIAIJ,
3273                                 /* 4*/ MatMultAdd_MPIAIJ,
3274                                        MatMultTranspose_MPIAIJ,
3275                                        MatMultTransposeAdd_MPIAIJ,
3276 #if defined(PETSC_HAVE_PBGL)
3277                                        MatSolve_MPIAIJ,
3278 #else
3279                                        0,
3280 #endif
3281                                        0,
3282                                        0,
3283                                 /*10*/ 0,
3284                                        0,
3285                                        0,
3286                                        MatSOR_MPIAIJ,
3287                                        MatTranspose_MPIAIJ,
3288                                 /*15*/ MatGetInfo_MPIAIJ,
3289                                        MatEqual_MPIAIJ,
3290                                        MatGetDiagonal_MPIAIJ,
3291                                        MatDiagonalScale_MPIAIJ,
3292                                        MatNorm_MPIAIJ,
3293                                 /*20*/ MatAssemblyBegin_MPIAIJ,
3294                                        MatAssemblyEnd_MPIAIJ,
3295                                        MatSetOption_MPIAIJ,
3296                                        MatZeroEntries_MPIAIJ,
3297                                 /*24*/ MatZeroRows_MPIAIJ,
3298                                        0,
3299 #if defined(PETSC_HAVE_PBGL)
3300                                        0,
3301 #else
3302                                        0,
3303 #endif
3304                                        0,
3305                                        0,
3306                                 /*29*/ MatSetUp_MPIAIJ,
3307 #if defined(PETSC_HAVE_PBGL)
3308                                        0,
3309 #else
3310                                        0,
3311 #endif
3312                                        0,
3313                                        0,
3314                                        0,
3315                                 /*34*/ MatDuplicate_MPIAIJ,
3316                                        0,
3317                                        0,
3318                                        0,
3319                                        0,
3320                                 /*39*/ MatAXPY_MPIAIJ,
3321                                        MatGetSubMatrices_MPIAIJ,
3322                                        MatIncreaseOverlap_MPIAIJ,
3323                                        MatGetValues_MPIAIJ,
3324                                        MatCopy_MPIAIJ,
3325                                 /*44*/ MatGetRowMax_MPIAIJ,
3326                                        MatScale_MPIAIJ,
3327                                        0,
3328                                        0,
3329                                        MatZeroRowsColumns_MPIAIJ,
3330                                 /*49*/ MatSetRandom_MPIAIJ,
3331                                        0,
3332                                        0,
3333                                        0,
3334                                        0,
3335                                 /*54*/ MatFDColoringCreate_MPIAIJ,
3336                                        0,
3337                                        MatSetUnfactored_MPIAIJ,
3338                                        MatPermute_MPIAIJ,
3339                                        0,
3340                                 /*59*/ MatGetSubMatrix_MPIAIJ,
3341                                        MatDestroy_MPIAIJ,
3342                                        MatView_MPIAIJ,
3343                                        0,
3344                                        MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ,
3345                                 /*64*/ MatMatMatMultSymbolic_MPIAIJ_MPIAIJ_MPIAIJ,
3346                                        MatMatMatMultNumeric_MPIAIJ_MPIAIJ_MPIAIJ,
3347                                        0,
3348                                        0,
3349                                        0,
3350                                 /*69*/ MatGetRowMaxAbs_MPIAIJ,
3351                                        MatGetRowMinAbs_MPIAIJ,
3352                                        0,
3353                                        MatSetColoring_MPIAIJ,
3354                                        0,
3355                                        MatSetValuesAdifor_MPIAIJ,
3356                                 /*75*/ MatFDColoringApply_AIJ,
3357                                        0,
3358                                        0,
3359                                        0,
3360                                        MatFindZeroDiagonals_MPIAIJ,
3361                                 /*80*/ 0,
3362                                        0,
3363                                        0,
3364                                 /*83*/ MatLoad_MPIAIJ,
3365                                        0,
3366                                        0,
3367                                        0,
3368                                        0,
3369                                        0,
3370                                 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
3371                                        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
3372                                        MatMatMultNumeric_MPIAIJ_MPIAIJ,
3373                                        MatPtAP_MPIAIJ_MPIAIJ,
3374                                        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
3375                                 /*94*/ MatPtAPNumeric_MPIAIJ_MPIAIJ,
3376                                        0,
3377                                        0,
3378                                        0,
3379                                        0,
3380                                 /*99*/ 0,
3381                                        0,
3382                                        0,
3383                                        MatConjugate_MPIAIJ,
3384                                        0,
3385                                 /*104*/MatSetValuesRow_MPIAIJ,
3386                                        MatRealPart_MPIAIJ,
3387                                        MatImaginaryPart_MPIAIJ,
3388                                        0,
3389                                        0,
3390                                 /*109*/0,
3391                                        MatGetRedundantMatrix_MPIAIJ,
3392                                        MatGetRowMin_MPIAIJ,
3393                                        0,
3394                                        0,
3395                                 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
3396                                        0,
3397                                        0,
3398                                        0,
3399                                        0,
3400                                 /*119*/0,
3401                                        0,
3402                                        0,
3403                                        0,
3404                                        MatGetMultiProcBlock_MPIAIJ,
3405                                 /*124*/MatFindNonzeroRows_MPIAIJ,
3406                                        MatGetColumnNorms_MPIAIJ,
3407                                        MatInvertBlockDiagonal_MPIAIJ,
3408                                        0,
3409                                        MatGetSubMatricesParallel_MPIAIJ,
3410                                 /*129*/0,
3411                                        MatTransposeMatMult_MPIAIJ_MPIAIJ,
3412                                        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
3413                                        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
3414                                        0,
3415                                 /*134*/0,
3416                                        0,
3417                                        0,
3418                                        0,
3419                                        0,
3420                                 /*139*/0,
3421                                        0
3422 };
3423 
3424 /* ----------------------------------------------------------------------------------------*/
3425 
3426 #undef __FUNCT__
3427 #define __FUNCT__ "MatStoreValues_MPIAIJ"
3428 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
3429 {
3430   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3431   PetscErrorCode ierr;
3432 
3433   PetscFunctionBegin;
3434   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
3435   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
3436   PetscFunctionReturn(0);
3437 }
3438 
3439 #undef __FUNCT__
3440 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
3441 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
3442 {
3443   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
3444   PetscErrorCode ierr;
3445 
3446   PetscFunctionBegin;
3447   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
3448   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
3449   PetscFunctionReturn(0);
3450 }
3451 
3452 #undef __FUNCT__
3453 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
3454 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3455 {
3456   Mat_MPIAIJ     *b;
3457   PetscErrorCode ierr;
3458 
3459   PetscFunctionBegin;
3460   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3461   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3462   b = (Mat_MPIAIJ*)B->data;
3463 
3464   if (!B->preallocated) {
3465     /* Explicitly create 2 MATSEQAIJ matrices. */
3466     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
3467     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
3468     ierr = MatSetBlockSizes(b->A,B->rmap->bs,B->cmap->bs);CHKERRQ(ierr);
3469     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
3470     ierr = PetscLogObjectParent(B,b->A);CHKERRQ(ierr);
3471     ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
3472     ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
3473     ierr = MatSetBlockSizes(b->B,B->rmap->bs,B->cmap->bs);CHKERRQ(ierr);
3474     ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
3475     ierr = PetscLogObjectParent(B,b->B);CHKERRQ(ierr);
3476   }
3477 
3478   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
3479   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
3480   B->preallocated = PETSC_TRUE;
3481   PetscFunctionReturn(0);
3482 }
3483 
3484 #undef __FUNCT__
3485 #define __FUNCT__ "MatDuplicate_MPIAIJ"
3486 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
3487 {
3488   Mat            mat;
3489   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
3490   PetscErrorCode ierr;
3491 
3492   PetscFunctionBegin;
3493   *newmat = 0;
3494   ierr    = MatCreate(PetscObjectComm((PetscObject)matin),&mat);CHKERRQ(ierr);
3495   ierr    = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
3496   ierr    = MatSetBlockSizes(mat,matin->rmap->bs,matin->cmap->bs);CHKERRQ(ierr);
3497   ierr    = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
3498   ierr    = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
3499   a       = (Mat_MPIAIJ*)mat->data;
3500 
3501   mat->factortype   = matin->factortype;
3502   mat->rmap->bs     = matin->rmap->bs;
3503   mat->cmap->bs     = matin->cmap->bs;
3504   mat->assembled    = PETSC_TRUE;
3505   mat->insertmode   = NOT_SET_VALUES;
3506   mat->preallocated = PETSC_TRUE;
3507 
3508   a->size         = oldmat->size;
3509   a->rank         = oldmat->rank;
3510   a->donotstash   = oldmat->donotstash;
3511   a->roworiented  = oldmat->roworiented;
3512   a->rowindices   = 0;
3513   a->rowvalues    = 0;
3514   a->getrowactive = PETSC_FALSE;
3515 
3516   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
3517   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
3518 
3519   if (oldmat->colmap) {
3520 #if defined(PETSC_USE_CTABLE)
3521     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
3522 #else
3523     ierr = PetscMalloc((mat->cmap->N)*sizeof(PetscInt),&a->colmap);CHKERRQ(ierr);
3524     ierr = PetscLogObjectMemory(mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3525     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3526 #endif
3527   } else a->colmap = 0;
3528   if (oldmat->garray) {
3529     PetscInt len;
3530     len  = oldmat->B->cmap->n;
3531     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&a->garray);CHKERRQ(ierr);
3532     ierr = PetscLogObjectMemory(mat,len*sizeof(PetscInt));CHKERRQ(ierr);
3533     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
3534   } else a->garray = 0;
3535 
3536   ierr    = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
3537   ierr    = PetscLogObjectParent(mat,a->lvec);CHKERRQ(ierr);
3538   ierr    = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
3539   ierr    = PetscLogObjectParent(mat,a->Mvctx);CHKERRQ(ierr);
3540   ierr    = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
3541   ierr    = PetscLogObjectParent(mat,a->A);CHKERRQ(ierr);
3542   ierr    = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
3543   ierr    = PetscLogObjectParent(mat,a->B);CHKERRQ(ierr);
3544   ierr    = PetscFunctionListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
3545   *newmat = mat;
3546   PetscFunctionReturn(0);
3547 }
3548 
3549 
3550 
3551 #undef __FUNCT__
3552 #define __FUNCT__ "MatLoad_MPIAIJ"
3553 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
3554 {
3555   PetscScalar    *vals,*svals;
3556   MPI_Comm       comm;
3557   PetscErrorCode ierr;
3558   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
3559   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0,grows,gcols;
3560   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
3561   PetscInt       *ourlens = NULL,*procsnz = NULL,*offlens = NULL,jj,*mycols,*smycols;
3562   PetscInt       cend,cstart,n,*rowners,sizesset=1;
3563   int            fd;
3564   PetscInt       bs = 1;
3565 
3566   PetscFunctionBegin;
3567   ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
3568   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3569   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3570   if (!rank) {
3571     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
3572     ierr = PetscBinaryRead(fd,(char*)header,4,PETSC_INT);CHKERRQ(ierr);
3573     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
3574   }
3575 
3576   ierr = PetscOptionsBegin(comm,NULL,"Options for loading SEQAIJ matrix","Mat");CHKERRQ(ierr);
3577   ierr = PetscOptionsInt("-matload_block_size","Set the blocksize used to store the matrix","MatLoad",bs,&bs,NULL);CHKERRQ(ierr);
3578   ierr = PetscOptionsEnd();CHKERRQ(ierr);
3579 
3580   if (newMat->rmap->n < 0 && newMat->rmap->N < 0 && newMat->cmap->n < 0 && newMat->cmap->N < 0) sizesset = 0;
3581 
3582   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
3583   M    = header[1]; N = header[2];
3584   /* If global rows/cols are set to PETSC_DECIDE, set it to the sizes given in the file */
3585   if (sizesset && newMat->rmap->N < 0) newMat->rmap->N = M;
3586   if (sizesset && newMat->cmap->N < 0) newMat->cmap->N = N;
3587 
3588   /* If global sizes are set, check if they are consistent with that given in the file */
3589   if (sizesset) {
3590     ierr = MatGetSize(newMat,&grows,&gcols);CHKERRQ(ierr);
3591   }
3592   if (sizesset && newMat->rmap->N != grows) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows:Matrix in file has (%d) and input matrix has (%d)",M,grows);
3593   if (sizesset && newMat->cmap->N != gcols) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of cols:Matrix in file has (%d) and input matrix has (%d)",N,gcols);
3594 
3595   /* determine ownership of all (block) rows */
3596   if (M%bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows (%d) and block size (%d)",M,bs);
3597   if (newMat->rmap->n < 0) m = bs*((M/bs)/size + (((M/bs) % size) > rank));    /* PETSC_DECIDE */
3598   else m = newMat->rmap->n; /* Set by user */
3599 
3600   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
3601   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
3602 
3603   /* First process needs enough room for process with most rows */
3604   if (!rank) {
3605     mmax = rowners[1];
3606     for (i=2; i<=size; i++) {
3607       mmax = PetscMax(mmax, rowners[i]);
3608     }
3609   } else mmax = -1;             /* unused, but compilers complain */
3610 
3611   rowners[0] = 0;
3612   for (i=2; i<=size; i++) {
3613     rowners[i] += rowners[i-1];
3614   }
3615   rstart = rowners[rank];
3616   rend   = rowners[rank+1];
3617 
3618   /* distribute row lengths to all processors */
3619   ierr = PetscMalloc2(m,PetscInt,&ourlens,m,PetscInt,&offlens);CHKERRQ(ierr);
3620   if (!rank) {
3621     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
3622     ierr = PetscMalloc(mmax*sizeof(PetscInt),&rowlengths);CHKERRQ(ierr);
3623     ierr = PetscMalloc(size*sizeof(PetscInt),&procsnz);CHKERRQ(ierr);
3624     ierr = PetscMemzero(procsnz,size*sizeof(PetscInt));CHKERRQ(ierr);
3625     for (j=0; j<m; j++) {
3626       procsnz[0] += ourlens[j];
3627     }
3628     for (i=1; i<size; i++) {
3629       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
3630       /* calculate the number of nonzeros on each processor */
3631       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
3632         procsnz[i] += rowlengths[j];
3633       }
3634       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3635     }
3636     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
3637   } else {
3638     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3639   }
3640 
3641   if (!rank) {
3642     /* determine max buffer needed and allocate it */
3643     maxnz = 0;
3644     for (i=0; i<size; i++) {
3645       maxnz = PetscMax(maxnz,procsnz[i]);
3646     }
3647     ierr = PetscMalloc(maxnz*sizeof(PetscInt),&cols);CHKERRQ(ierr);
3648 
3649     /* read in my part of the matrix column indices  */
3650     nz   = procsnz[0];
3651     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
3652     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
3653 
3654     /* read in every one elses and ship off */
3655     for (i=1; i<size; i++) {
3656       nz   = procsnz[i];
3657       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
3658       ierr = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3659     }
3660     ierr = PetscFree(cols);CHKERRQ(ierr);
3661   } else {
3662     /* determine buffer space needed for message */
3663     nz = 0;
3664     for (i=0; i<m; i++) {
3665       nz += ourlens[i];
3666     }
3667     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
3668 
3669     /* receive message of column indices*/
3670     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3671   }
3672 
3673   /* determine column ownership if matrix is not square */
3674   if (N != M) {
3675     if (newMat->cmap->n < 0) n = N/size + ((N % size) > rank);
3676     else n = newMat->cmap->n;
3677     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3678     cstart = cend - n;
3679   } else {
3680     cstart = rstart;
3681     cend   = rend;
3682     n      = cend - cstart;
3683   }
3684 
3685   /* loop over local rows, determining number of off diagonal entries */
3686   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
3687   jj   = 0;
3688   for (i=0; i<m; i++) {
3689     for (j=0; j<ourlens[i]; j++) {
3690       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
3691       jj++;
3692     }
3693   }
3694 
3695   for (i=0; i<m; i++) {
3696     ourlens[i] -= offlens[i];
3697   }
3698   if (!sizesset) {
3699     ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
3700   }
3701 
3702   if (bs > 1) {ierr = MatSetBlockSize(newMat,bs);CHKERRQ(ierr);}
3703 
3704   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
3705 
3706   for (i=0; i<m; i++) {
3707     ourlens[i] += offlens[i];
3708   }
3709 
3710   if (!rank) {
3711     ierr = PetscMalloc((maxnz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
3712 
3713     /* read in my part of the matrix numerical values  */
3714     nz   = procsnz[0];
3715     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3716 
3717     /* insert into matrix */
3718     jj      = rstart;
3719     smycols = mycols;
3720     svals   = vals;
3721     for (i=0; i<m; i++) {
3722       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3723       smycols += ourlens[i];
3724       svals   += ourlens[i];
3725       jj++;
3726     }
3727 
3728     /* read in other processors and ship out */
3729     for (i=1; i<size; i++) {
3730       nz   = procsnz[i];
3731       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3732       ierr = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3733     }
3734     ierr = PetscFree(procsnz);CHKERRQ(ierr);
3735   } else {
3736     /* receive numeric values */
3737     ierr = PetscMalloc((nz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
3738 
3739     /* receive message of values*/
3740     ierr = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3741 
3742     /* insert into matrix */
3743     jj      = rstart;
3744     smycols = mycols;
3745     svals   = vals;
3746     for (i=0; i<m; i++) {
3747       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3748       smycols += ourlens[i];
3749       svals   += ourlens[i];
3750       jj++;
3751     }
3752   }
3753   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
3754   ierr = PetscFree(vals);CHKERRQ(ierr);
3755   ierr = PetscFree(mycols);CHKERRQ(ierr);
3756   ierr = PetscFree(rowners);CHKERRQ(ierr);
3757   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3758   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3759   PetscFunctionReturn(0);
3760 }
3761 
3762 #undef __FUNCT__
3763 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3764 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3765 {
3766   PetscErrorCode ierr;
3767   IS             iscol_local;
3768   PetscInt       csize;
3769 
3770   PetscFunctionBegin;
3771   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3772   if (call == MAT_REUSE_MATRIX) {
3773     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3774     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3775   } else {
3776     PetscInt cbs;
3777     ierr = ISGetBlockSize(iscol,&cbs);CHKERRQ(ierr);
3778     ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
3779     ierr = ISSetBlockSize(iscol_local,cbs);CHKERRQ(ierr);
3780   }
3781   ierr = MatGetSubMatrix_MPIAIJ_Private(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3782   if (call == MAT_INITIAL_MATRIX) {
3783     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3784     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3785   }
3786   PetscFunctionReturn(0);
3787 }
3788 
3789 extern PetscErrorCode MatGetSubMatrices_MPIAIJ_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool*,Mat*);
3790 #undef __FUNCT__
3791 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ_Private"
3792 /*
3793     Not great since it makes two copies of the submatrix, first an SeqAIJ
3794   in local and then by concatenating the local matrices the end result.
3795   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3796 
3797   Note: This requires a sequential iscol with all indices.
3798 */
3799 PetscErrorCode MatGetSubMatrix_MPIAIJ_Private(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3800 {
3801   PetscErrorCode ierr;
3802   PetscMPIInt    rank,size;
3803   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3804   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal,ncol;
3805   PetscBool      allcolumns, colflag;
3806   Mat            M,Mreuse;
3807   MatScalar      *vwork,*aa;
3808   MPI_Comm       comm;
3809   Mat_SeqAIJ     *aij;
3810 
3811   PetscFunctionBegin;
3812   ierr = PetscObjectGetComm((PetscObject)mat,&comm);CHKERRQ(ierr);
3813   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3814   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3815 
3816   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3817   ierr = ISGetLocalSize(iscol,&ncol);CHKERRQ(ierr);
3818   if (colflag && ncol == mat->cmap->N) {
3819     allcolumns = PETSC_TRUE;
3820   } else {
3821     allcolumns = PETSC_FALSE;
3822   }
3823   if (call ==  MAT_REUSE_MATRIX) {
3824     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject*)&Mreuse);CHKERRQ(ierr);
3825     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3826     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3827   } else {
3828     ierr = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3829   }
3830 
3831   /*
3832       m - number of local rows
3833       n - number of columns (same on all processors)
3834       rstart - first row in new global matrix generated
3835   */
3836   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3837   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3838   if (call == MAT_INITIAL_MATRIX) {
3839     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3840     ii  = aij->i;
3841     jj  = aij->j;
3842 
3843     /*
3844         Determine the number of non-zeros in the diagonal and off-diagonal
3845         portions of the matrix in order to do correct preallocation
3846     */
3847 
3848     /* first get start and end of "diagonal" columns */
3849     if (csize == PETSC_DECIDE) {
3850       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3851       if (mglobal == n) { /* square matrix */
3852         nlocal = m;
3853       } else {
3854         nlocal = n/size + ((n % size) > rank);
3855       }
3856     } else {
3857       nlocal = csize;
3858     }
3859     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3860     rstart = rend - nlocal;
3861     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);
3862 
3863     /* next, compute all the lengths */
3864     ierr  = PetscMalloc((2*m+1)*sizeof(PetscInt),&dlens);CHKERRQ(ierr);
3865     olens = dlens + m;
3866     for (i=0; i<m; i++) {
3867       jend = ii[i+1] - ii[i];
3868       olen = 0;
3869       dlen = 0;
3870       for (j=0; j<jend; j++) {
3871         if (*jj < rstart || *jj >= rend) olen++;
3872         else dlen++;
3873         jj++;
3874       }
3875       olens[i] = olen;
3876       dlens[i] = dlen;
3877     }
3878     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3879     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3880     ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr);
3881     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3882     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3883     ierr = PetscFree(dlens);CHKERRQ(ierr);
3884   } else {
3885     PetscInt ml,nl;
3886 
3887     M    = *newmat;
3888     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3889     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3890     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3891     /*
3892          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3893        rather than the slower MatSetValues().
3894     */
3895     M->was_assembled = PETSC_TRUE;
3896     M->assembled     = PETSC_FALSE;
3897   }
3898   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3899   aij  = (Mat_SeqAIJ*)(Mreuse)->data;
3900   ii   = aij->i;
3901   jj   = aij->j;
3902   aa   = aij->a;
3903   for (i=0; i<m; i++) {
3904     row   = rstart + i;
3905     nz    = ii[i+1] - ii[i];
3906     cwork = jj;     jj += nz;
3907     vwork = aa;     aa += nz;
3908     ierr  = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3909   }
3910 
3911   ierr    = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3912   ierr    = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3913   *newmat = M;
3914 
3915   /* save submatrix used in processor for next request */
3916   if (call ==  MAT_INITIAL_MATRIX) {
3917     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3918     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3919   }
3920   PetscFunctionReturn(0);
3921 }
3922 
3923 #undef __FUNCT__
3924 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3925 PetscErrorCode  MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3926 {
3927   PetscInt       m,cstart, cend,j,nnz,i,d;
3928   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3929   const PetscInt *JJ;
3930   PetscScalar    *values;
3931   PetscErrorCode ierr;
3932 
3933   PetscFunctionBegin;
3934   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3935 
3936   ierr   = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3937   ierr   = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3938   m      = B->rmap->n;
3939   cstart = B->cmap->rstart;
3940   cend   = B->cmap->rend;
3941   rstart = B->rmap->rstart;
3942 
3943   ierr = PetscMalloc2(m,PetscInt,&d_nnz,m,PetscInt,&o_nnz);CHKERRQ(ierr);
3944 
3945 #if defined(PETSC_USE_DEBUGGING)
3946   for (i=0; i<m; i++) {
3947     nnz = Ii[i+1]- Ii[i];
3948     JJ  = J + Ii[i];
3949     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3950     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3951     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);
3952   }
3953 #endif
3954 
3955   for (i=0; i<m; i++) {
3956     nnz     = Ii[i+1]- Ii[i];
3957     JJ      = J + Ii[i];
3958     nnz_max = PetscMax(nnz_max,nnz);
3959     d       = 0;
3960     for (j=0; j<nnz; j++) {
3961       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3962     }
3963     d_nnz[i] = d;
3964     o_nnz[i] = nnz - d;
3965   }
3966   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3967   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3968 
3969   if (v) values = (PetscScalar*)v;
3970   else {
3971     ierr = PetscMalloc((nnz_max+1)*sizeof(PetscScalar),&values);CHKERRQ(ierr);
3972     ierr = PetscMemzero(values,nnz_max*sizeof(PetscScalar));CHKERRQ(ierr);
3973   }
3974 
3975   for (i=0; i<m; i++) {
3976     ii   = i + rstart;
3977     nnz  = Ii[i+1]- Ii[i];
3978     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3979   }
3980   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3981   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3982 
3983   if (!v) {
3984     ierr = PetscFree(values);CHKERRQ(ierr);
3985   }
3986   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3987   PetscFunctionReturn(0);
3988 }
3989 
3990 #undef __FUNCT__
3991 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3992 /*@
3993    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3994    (the default parallel PETSc format).
3995 
3996    Collective on MPI_Comm
3997 
3998    Input Parameters:
3999 +  B - the matrix
4000 .  i - the indices into j for the start of each local row (starts with zero)
4001 .  j - the column indices for each local row (starts with zero)
4002 -  v - optional values in the matrix
4003 
4004    Level: developer
4005 
4006    Notes:
4007        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
4008      thus you CANNOT change the matrix entries by changing the values of a[] after you have
4009      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
4010 
4011        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
4012 
4013        The format which is used for the sparse matrix input, is equivalent to a
4014     row-major ordering.. i.e for the following matrix, the input data expected is
4015     as shown:
4016 
4017         1 0 0
4018         2 0 3     P0
4019        -------
4020         4 5 6     P1
4021 
4022      Process0 [P0]: rows_owned=[0,1]
4023         i =  {0,1,3}  [size = nrow+1  = 2+1]
4024         j =  {0,0,2}  [size = nz = 6]
4025         v =  {1,2,3}  [size = nz = 6]
4026 
4027      Process1 [P1]: rows_owned=[2]
4028         i =  {0,3}    [size = nrow+1  = 1+1]
4029         j =  {0,1,2}  [size = nz = 6]
4030         v =  {4,5,6}  [size = nz = 6]
4031 
4032 .keywords: matrix, aij, compressed row, sparse, parallel
4033 
4034 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MPIAIJ,
4035           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
4036 @*/
4037 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
4038 {
4039   PetscErrorCode ierr;
4040 
4041   PetscFunctionBegin;
4042   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
4043   PetscFunctionReturn(0);
4044 }
4045 
4046 #undef __FUNCT__
4047 #define __FUNCT__ "MatMPIAIJSetPreallocation"
4048 /*@C
4049    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
4050    (the default parallel PETSc format).  For good matrix assembly performance
4051    the user should preallocate the matrix storage by setting the parameters
4052    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4053    performance can be increased by more than a factor of 50.
4054 
4055    Collective on MPI_Comm
4056 
4057    Input Parameters:
4058 +  A - the matrix
4059 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4060            (same value is used for all local rows)
4061 .  d_nnz - array containing the number of nonzeros in the various rows of the
4062            DIAGONAL portion of the local submatrix (possibly different for each row)
4063            or NULL, if d_nz is used to specify the nonzero structure.
4064            The size of this array is equal to the number of local rows, i.e 'm'.
4065            For matrices that will be factored, you must leave room for (and set)
4066            the diagonal entry even if it is zero.
4067 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4068            submatrix (same value is used for all local rows).
4069 -  o_nnz - array containing the number of nonzeros in the various rows of the
4070            OFF-DIAGONAL portion of the local submatrix (possibly different for
4071            each row) or NULL, if o_nz is used to specify the nonzero
4072            structure. The size of this array is equal to the number
4073            of local rows, i.e 'm'.
4074 
4075    If the *_nnz parameter is given then the *_nz parameter is ignored
4076 
4077    The AIJ format (also called the Yale sparse matrix format or
4078    compressed row storage (CSR)), is fully compatible with standard Fortran 77
4079    storage.  The stored row and column indices begin with zero.
4080    See the <A href="../../docs/manual.pdf#nameddest=ch_mat">Mat chapter of the users manual</A> for details.
4081 
4082    The parallel matrix is partitioned such that the first m0 rows belong to
4083    process 0, the next m1 rows belong to process 1, the next m2 rows belong
4084    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
4085 
4086    The DIAGONAL portion of the local submatrix of a processor can be defined
4087    as the submatrix which is obtained by extraction the part corresponding to
4088    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
4089    first row that belongs to the processor, r2 is the last row belonging to
4090    the this processor, and c1-c2 is range of indices of the local part of a
4091    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
4092    common case of a square matrix, the row and column ranges are the same and
4093    the DIAGONAL part is also square. The remaining portion of the local
4094    submatrix (mxN) constitute the OFF-DIAGONAL portion.
4095 
4096    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4097 
4098    You can call MatGetInfo() to get information on how effective the preallocation was;
4099    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
4100    You can also run with the option -info and look for messages with the string
4101    malloc in them to see if additional memory allocation was needed.
4102 
4103    Example usage:
4104 
4105    Consider the following 8x8 matrix with 34 non-zero values, that is
4106    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4107    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4108    as follows:
4109 
4110 .vb
4111             1  2  0  |  0  3  0  |  0  4
4112     Proc0   0  5  6  |  7  0  0  |  8  0
4113             9  0 10  | 11  0  0  | 12  0
4114     -------------------------------------
4115            13  0 14  | 15 16 17  |  0  0
4116     Proc1   0 18  0  | 19 20 21  |  0  0
4117             0  0  0  | 22 23  0  | 24  0
4118     -------------------------------------
4119     Proc2  25 26 27  |  0  0 28  | 29  0
4120            30  0  0  | 31 32 33  |  0 34
4121 .ve
4122 
4123    This can be represented as a collection of submatrices as:
4124 
4125 .vb
4126       A B C
4127       D E F
4128       G H I
4129 .ve
4130 
4131    Where the submatrices A,B,C are owned by proc0, D,E,F are
4132    owned by proc1, G,H,I are owned by proc2.
4133 
4134    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4135    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4136    The 'M','N' parameters are 8,8, and have the same values on all procs.
4137 
4138    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4139    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4140    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4141    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4142    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4143    matrix, ans [DF] as another SeqAIJ matrix.
4144 
4145    When d_nz, o_nz parameters are specified, d_nz storage elements are
4146    allocated for every row of the local diagonal submatrix, and o_nz
4147    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4148    One way to choose d_nz and o_nz is to use the max nonzerors per local
4149    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4150    In this case, the values of d_nz,o_nz are:
4151 .vb
4152      proc0 : dnz = 2, o_nz = 2
4153      proc1 : dnz = 3, o_nz = 2
4154      proc2 : dnz = 1, o_nz = 4
4155 .ve
4156    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4157    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4158    for proc3. i.e we are using 12+15+10=37 storage locations to store
4159    34 values.
4160 
4161    When d_nnz, o_nnz parameters are specified, the storage is specified
4162    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4163    In the above case the values for d_nnz,o_nnz are:
4164 .vb
4165      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4166      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4167      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4168 .ve
4169    Here the space allocated is sum of all the above values i.e 34, and
4170    hence pre-allocation is perfect.
4171 
4172    Level: intermediate
4173 
4174 .keywords: matrix, aij, compressed row, sparse, parallel
4175 
4176 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
4177           MPIAIJ, MatGetInfo(), PetscSplitOwnership()
4178 @*/
4179 PetscErrorCode  MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
4180 {
4181   PetscErrorCode ierr;
4182 
4183   PetscFunctionBegin;
4184   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
4185   PetscValidType(B,1);
4186   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
4187   PetscFunctionReturn(0);
4188 }
4189 
4190 #undef __FUNCT__
4191 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
4192 /*@
4193      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
4194          CSR format the local rows.
4195 
4196    Collective on MPI_Comm
4197 
4198    Input Parameters:
4199 +  comm - MPI communicator
4200 .  m - number of local rows (Cannot be PETSC_DECIDE)
4201 .  n - This value should be the same as the local size used in creating the
4202        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4203        calculated if N is given) For square matrices n is almost always m.
4204 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4205 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4206 .   i - row indices
4207 .   j - column indices
4208 -   a - matrix values
4209 
4210    Output Parameter:
4211 .   mat - the matrix
4212 
4213    Level: intermediate
4214 
4215    Notes:
4216        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
4217      thus you CANNOT change the matrix entries by changing the values of a[] after you have
4218      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
4219 
4220        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
4221 
4222        The format which is used for the sparse matrix input, is equivalent to a
4223     row-major ordering.. i.e for the following matrix, the input data expected is
4224     as shown:
4225 
4226         1 0 0
4227         2 0 3     P0
4228        -------
4229         4 5 6     P1
4230 
4231      Process0 [P0]: rows_owned=[0,1]
4232         i =  {0,1,3}  [size = nrow+1  = 2+1]
4233         j =  {0,0,2}  [size = nz = 6]
4234         v =  {1,2,3}  [size = nz = 6]
4235 
4236      Process1 [P1]: rows_owned=[2]
4237         i =  {0,3}    [size = nrow+1  = 1+1]
4238         j =  {0,1,2}  [size = nz = 6]
4239         v =  {4,5,6}  [size = nz = 6]
4240 
4241 .keywords: matrix, aij, compressed row, sparse, parallel
4242 
4243 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4244           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
4245 @*/
4246 PetscErrorCode  MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
4247 {
4248   PetscErrorCode ierr;
4249 
4250   PetscFunctionBegin;
4251   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
4252   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
4253   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
4254   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
4255   /* ierr = MatSetBlockSizes(M,bs,cbs);CHKERRQ(ierr); */
4256   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
4257   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
4258   PetscFunctionReturn(0);
4259 }
4260 
4261 #undef __FUNCT__
4262 #define __FUNCT__ "MatCreateAIJ"
4263 /*@C
4264    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
4265    (the default parallel PETSc format).  For good matrix assembly performance
4266    the user should preallocate the matrix storage by setting the parameters
4267    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4268    performance can be increased by more than a factor of 50.
4269 
4270    Collective on MPI_Comm
4271 
4272    Input Parameters:
4273 +  comm - MPI communicator
4274 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
4275            This value should be the same as the local size used in creating the
4276            y vector for the matrix-vector product y = Ax.
4277 .  n - This value should be the same as the local size used in creating the
4278        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4279        calculated if N is given) For square matrices n is almost always m.
4280 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4281 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4282 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4283            (same value is used for all local rows)
4284 .  d_nnz - array containing the number of nonzeros in the various rows of the
4285            DIAGONAL portion of the local submatrix (possibly different for each row)
4286            or NULL, if d_nz is used to specify the nonzero structure.
4287            The size of this array is equal to the number of local rows, i.e 'm'.
4288 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4289            submatrix (same value is used for all local rows).
4290 -  o_nnz - array containing the number of nonzeros in the various rows of the
4291            OFF-DIAGONAL portion of the local submatrix (possibly different for
4292            each row) or NULL, if o_nz is used to specify the nonzero
4293            structure. The size of this array is equal to the number
4294            of local rows, i.e 'm'.
4295 
4296    Output Parameter:
4297 .  A - the matrix
4298 
4299    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
4300    MatXXXXSetPreallocation() paradgm instead of this routine directly.
4301    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
4302 
4303    Notes:
4304    If the *_nnz parameter is given then the *_nz parameter is ignored
4305 
4306    m,n,M,N parameters specify the size of the matrix, and its partitioning across
4307    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
4308    storage requirements for this matrix.
4309 
4310    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
4311    processor than it must be used on all processors that share the object for
4312    that argument.
4313 
4314    The user MUST specify either the local or global matrix dimensions
4315    (possibly both).
4316 
4317    The parallel matrix is partitioned across processors such that the
4318    first m0 rows belong to process 0, the next m1 rows belong to
4319    process 1, the next m2 rows belong to process 2 etc.. where
4320    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
4321    values corresponding to [m x N] submatrix.
4322 
4323    The columns are logically partitioned with the n0 columns belonging
4324    to 0th partition, the next n1 columns belonging to the next
4325    partition etc.. where n0,n1,n2... are the the input parameter 'n'.
4326 
4327    The DIAGONAL portion of the local submatrix on any given processor
4328    is the submatrix corresponding to the rows and columns m,n
4329    corresponding to the given processor. i.e diagonal matrix on
4330    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4331    etc. The remaining portion of the local submatrix [m x (N-n)]
4332    constitute the OFF-DIAGONAL portion. The example below better
4333    illustrates this concept.
4334 
4335    For a square global matrix we define each processor's diagonal portion
4336    to be its local rows and the corresponding columns (a square submatrix);
4337    each processor's off-diagonal portion encompasses the remainder of the
4338    local matrix (a rectangular submatrix).
4339 
4340    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4341 
4342    When calling this routine with a single process communicator, a matrix of
4343    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
4344    type of communicator, use the construction mechanism:
4345      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
4346 
4347    By default, this format uses inodes (identical nodes) when possible.
4348    We search for consecutive rows with the same nonzero structure, thereby
4349    reusing matrix information to achieve increased efficiency.
4350 
4351    Options Database Keys:
4352 +  -mat_no_inode  - Do not use inodes
4353 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
4354 -  -mat_aij_oneindex - Internally use indexing starting at 1
4355         rather than 0.  Note that when calling MatSetValues(),
4356         the user still MUST index entries starting at 0!
4357 
4358 
4359    Example usage:
4360 
4361    Consider the following 8x8 matrix with 34 non-zero values, that is
4362    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4363    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4364    as follows:
4365 
4366 .vb
4367             1  2  0  |  0  3  0  |  0  4
4368     Proc0   0  5  6  |  7  0  0  |  8  0
4369             9  0 10  | 11  0  0  | 12  0
4370     -------------------------------------
4371            13  0 14  | 15 16 17  |  0  0
4372     Proc1   0 18  0  | 19 20 21  |  0  0
4373             0  0  0  | 22 23  0  | 24  0
4374     -------------------------------------
4375     Proc2  25 26 27  |  0  0 28  | 29  0
4376            30  0  0  | 31 32 33  |  0 34
4377 .ve
4378 
4379    This can be represented as a collection of submatrices as:
4380 
4381 .vb
4382       A B C
4383       D E F
4384       G H I
4385 .ve
4386 
4387    Where the submatrices A,B,C are owned by proc0, D,E,F are
4388    owned by proc1, G,H,I are owned by proc2.
4389 
4390    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4391    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4392    The 'M','N' parameters are 8,8, and have the same values on all procs.
4393 
4394    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4395    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4396    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4397    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4398    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4399    matrix, ans [DF] as another SeqAIJ matrix.
4400 
4401    When d_nz, o_nz parameters are specified, d_nz storage elements are
4402    allocated for every row of the local diagonal submatrix, and o_nz
4403    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4404    One way to choose d_nz and o_nz is to use the max nonzerors per local
4405    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4406    In this case, the values of d_nz,o_nz are:
4407 .vb
4408      proc0 : dnz = 2, o_nz = 2
4409      proc1 : dnz = 3, o_nz = 2
4410      proc2 : dnz = 1, o_nz = 4
4411 .ve
4412    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4413    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4414    for proc3. i.e we are using 12+15+10=37 storage locations to store
4415    34 values.
4416 
4417    When d_nnz, o_nnz parameters are specified, the storage is specified
4418    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4419    In the above case the values for d_nnz,o_nnz are:
4420 .vb
4421      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4422      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4423      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4424 .ve
4425    Here the space allocated is sum of all the above values i.e 34, and
4426    hence pre-allocation is perfect.
4427 
4428    Level: intermediate
4429 
4430 .keywords: matrix, aij, compressed row, sparse, parallel
4431 
4432 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4433           MPIAIJ, MatCreateMPIAIJWithArrays()
4434 @*/
4435 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)
4436 {
4437   PetscErrorCode ierr;
4438   PetscMPIInt    size;
4439 
4440   PetscFunctionBegin;
4441   ierr = MatCreate(comm,A);CHKERRQ(ierr);
4442   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
4443   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4444   if (size > 1) {
4445     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
4446     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
4447   } else {
4448     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
4449     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
4450   }
4451   PetscFunctionReturn(0);
4452 }
4453 
4454 #undef __FUNCT__
4455 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
4456 PetscErrorCode  MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,const PetscInt *colmap[])
4457 {
4458   Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
4459 
4460   PetscFunctionBegin;
4461   *Ad     = a->A;
4462   *Ao     = a->B;
4463   *colmap = a->garray;
4464   PetscFunctionReturn(0);
4465 }
4466 
4467 #undef __FUNCT__
4468 #define __FUNCT__ "MatSetColoring_MPIAIJ"
4469 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
4470 {
4471   PetscErrorCode ierr;
4472   PetscInt       i;
4473   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4474 
4475   PetscFunctionBegin;
4476   if (coloring->ctype == IS_COLORING_GLOBAL) {
4477     ISColoringValue *allcolors,*colors;
4478     ISColoring      ocoloring;
4479 
4480     /* set coloring for diagonal portion */
4481     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
4482 
4483     /* set coloring for off-diagonal portion */
4484     ierr = ISAllGatherColors(PetscObjectComm((PetscObject)A),coloring->n,coloring->colors,NULL,&allcolors);CHKERRQ(ierr);
4485     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
4486     for (i=0; i<a->B->cmap->n; i++) {
4487       colors[i] = allcolors[a->garray[i]];
4488     }
4489     ierr = PetscFree(allcolors);CHKERRQ(ierr);
4490     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4491     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4492     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4493   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
4494     ISColoringValue *colors;
4495     PetscInt        *larray;
4496     ISColoring      ocoloring;
4497 
4498     /* set coloring for diagonal portion */
4499     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
4500     for (i=0; i<a->A->cmap->n; i++) {
4501       larray[i] = i + A->cmap->rstart;
4502     }
4503     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,NULL,larray);CHKERRQ(ierr);
4504     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
4505     for (i=0; i<a->A->cmap->n; i++) {
4506       colors[i] = coloring->colors[larray[i]];
4507     }
4508     ierr = PetscFree(larray);CHKERRQ(ierr);
4509     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4510     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
4511     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4512 
4513     /* set coloring for off-diagonal portion */
4514     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
4515     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,NULL,larray);CHKERRQ(ierr);
4516     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
4517     for (i=0; i<a->B->cmap->n; i++) {
4518       colors[i] = coloring->colors[larray[i]];
4519     }
4520     ierr = PetscFree(larray);CHKERRQ(ierr);
4521     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4522     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4523     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4524   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
4525   PetscFunctionReturn(0);
4526 }
4527 
4528 #undef __FUNCT__
4529 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
4530 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
4531 {
4532   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4533   PetscErrorCode ierr;
4534 
4535   PetscFunctionBegin;
4536   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
4537   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
4538   PetscFunctionReturn(0);
4539 }
4540 
4541 #undef __FUNCT__
4542 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJSymbolic"
4543 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJSymbolic(MPI_Comm comm,Mat inmat,PetscInt n,Mat *outmat)
4544 {
4545   PetscErrorCode ierr;
4546   PetscInt       m,N,i,rstart,nnz,*dnz,*onz,sum,bs,cbs;
4547   PetscInt       *indx;
4548 
4549   PetscFunctionBegin;
4550   /* This routine will ONLY return MPIAIJ type matrix */
4551   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4552   ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
4553   if (n == PETSC_DECIDE) {
4554     ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
4555   }
4556   /* Check sum(n) = N */
4557   ierr = MPI_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4558   if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
4559 
4560   ierr    = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4561   rstart -= m;
4562 
4563   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4564   for (i=0; i<m; i++) {
4565     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4566     ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
4567     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,NULL);CHKERRQ(ierr);
4568   }
4569 
4570   ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
4571   ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4572   ierr = MatSetBlockSizes(*outmat,bs,cbs);CHKERRQ(ierr);
4573   ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
4574   ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
4575   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4576   PetscFunctionReturn(0);
4577 }
4578 
4579 #undef __FUNCT__
4580 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJNumeric"
4581 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJNumeric(MPI_Comm comm,Mat inmat,PetscInt n,Mat outmat)
4582 {
4583   PetscErrorCode ierr;
4584   PetscInt       m,N,i,rstart,nnz,Ii;
4585   PetscInt       *indx;
4586   PetscScalar    *values;
4587 
4588   PetscFunctionBegin;
4589   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4590   ierr = MatGetOwnershipRange(outmat,&rstart,NULL);CHKERRQ(ierr);
4591   for (i=0; i<m; i++) {
4592     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4593     Ii   = i + rstart;
4594     ierr = MatSetValues(outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4595     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4596   }
4597   ierr = MatAssemblyBegin(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4598   ierr = MatAssemblyEnd(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4599   PetscFunctionReturn(0);
4600 }
4601 
4602 #undef __FUNCT__
4603 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJ"
4604 /*@
4605       MatCreateMPIAIJConcatenateSeqAIJ - Creates a single large PETSc matrix by concatenating sequential
4606                  matrices from each processor
4607 
4608     Collective on MPI_Comm
4609 
4610    Input Parameters:
4611 +    comm - the communicators the parallel matrix will live on
4612 .    inmat - the input sequential matrices
4613 .    n - number of local columns (or PETSC_DECIDE)
4614 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4615 
4616    Output Parameter:
4617 .    outmat - the parallel matrix generated
4618 
4619     Level: advanced
4620 
4621    Notes: The number of columns of the matrix in EACH processor MUST be the same.
4622 
4623 @*/
4624 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
4625 {
4626   PetscErrorCode ierr;
4627 
4628   PetscFunctionBegin;
4629   ierr = PetscLogEventBegin(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4630   if (scall == MAT_INITIAL_MATRIX) {
4631     ierr = MatCreateMPIAIJConcatenateSeqAIJSymbolic(comm,inmat,n,outmat);CHKERRQ(ierr);
4632   }
4633   ierr = MatCreateMPIAIJConcatenateSeqAIJNumeric(comm,inmat,n,*outmat);CHKERRQ(ierr);
4634   ierr = PetscLogEventEnd(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4635   PetscFunctionReturn(0);
4636 }
4637 
4638 #undef __FUNCT__
4639 #define __FUNCT__ "MatFileSplit"
4640 PetscErrorCode MatFileSplit(Mat A,char *outfile)
4641 {
4642   PetscErrorCode    ierr;
4643   PetscMPIInt       rank;
4644   PetscInt          m,N,i,rstart,nnz;
4645   size_t            len;
4646   const PetscInt    *indx;
4647   PetscViewer       out;
4648   char              *name;
4649   Mat               B;
4650   const PetscScalar *values;
4651 
4652   PetscFunctionBegin;
4653   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
4654   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
4655   /* Should this be the type of the diagonal block of A? */
4656   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
4657   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
4658   ierr = MatSetBlockSizes(B,A->rmap->bs,A->cmap->bs);CHKERRQ(ierr);
4659   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
4660   ierr = MatSeqAIJSetPreallocation(B,0,NULL);CHKERRQ(ierr);
4661   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
4662   for (i=0; i<m; i++) {
4663     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4664     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4665     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4666   }
4667   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4668   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4669 
4670   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
4671   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
4672   ierr = PetscMalloc((len+5)*sizeof(char),&name);CHKERRQ(ierr);
4673   sprintf(name,"%s.%d",outfile,rank);
4674   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
4675   ierr = PetscFree(name);CHKERRQ(ierr);
4676   ierr = MatView(B,out);CHKERRQ(ierr);
4677   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
4678   ierr = MatDestroy(&B);CHKERRQ(ierr);
4679   PetscFunctionReturn(0);
4680 }
4681 
4682 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
4683 #undef __FUNCT__
4684 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
4685 PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
4686 {
4687   PetscErrorCode      ierr;
4688   Mat_Merge_SeqsToMPI *merge;
4689   PetscContainer      container;
4690 
4691   PetscFunctionBegin;
4692   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4693   if (container) {
4694     ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4695     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
4696     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
4697     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
4698     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
4699     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
4700     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
4701     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
4702     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
4703     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
4704     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
4705     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
4706     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
4707     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
4708     ierr = PetscFree(merge);CHKERRQ(ierr);
4709     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
4710   }
4711   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
4712   PetscFunctionReturn(0);
4713 }
4714 
4715 #include <../src/mat/utils/freespace.h>
4716 #include <petscbt.h>
4717 
4718 #undef __FUNCT__
4719 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJNumeric"
4720 PetscErrorCode  MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
4721 {
4722   PetscErrorCode      ierr;
4723   MPI_Comm            comm;
4724   Mat_SeqAIJ          *a  =(Mat_SeqAIJ*)seqmat->data;
4725   PetscMPIInt         size,rank,taga,*len_s;
4726   PetscInt            N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj;
4727   PetscInt            proc,m;
4728   PetscInt            **buf_ri,**buf_rj;
4729   PetscInt            k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
4730   PetscInt            nrows,**buf_ri_k,**nextrow,**nextai;
4731   MPI_Request         *s_waits,*r_waits;
4732   MPI_Status          *status;
4733   MatScalar           *aa=a->a;
4734   MatScalar           **abuf_r,*ba_i;
4735   Mat_Merge_SeqsToMPI *merge;
4736   PetscContainer      container;
4737 
4738   PetscFunctionBegin;
4739   ierr = PetscObjectGetComm((PetscObject)mpimat,&comm);CHKERRQ(ierr);
4740   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4741 
4742   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4743   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4744 
4745   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject*)&container);CHKERRQ(ierr);
4746   ierr = PetscContainerGetPointer(container,(void**)&merge);CHKERRQ(ierr);
4747 
4748   bi     = merge->bi;
4749   bj     = merge->bj;
4750   buf_ri = merge->buf_ri;
4751   buf_rj = merge->buf_rj;
4752 
4753   ierr   = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
4754   owners = merge->rowmap->range;
4755   len_s  = merge->len_s;
4756 
4757   /* send and recv matrix values */
4758   /*-----------------------------*/
4759   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
4760   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
4761 
4762   ierr = PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&s_waits);CHKERRQ(ierr);
4763   for (proc=0,k=0; proc<size; proc++) {
4764     if (!len_s[proc]) continue;
4765     i    = owners[proc];
4766     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4767     k++;
4768   }
4769 
4770   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4771   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4772   ierr = PetscFree(status);CHKERRQ(ierr);
4773 
4774   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4775   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4776 
4777   /* insert mat values of mpimat */
4778   /*----------------------------*/
4779   ierr = PetscMalloc(N*sizeof(PetscScalar),&ba_i);CHKERRQ(ierr);
4780   ierr = PetscMalloc3(merge->nrecv,PetscInt*,&buf_ri_k,merge->nrecv,PetscInt*,&nextrow,merge->nrecv,PetscInt*,&nextai);CHKERRQ(ierr);
4781 
4782   for (k=0; k<merge->nrecv; k++) {
4783     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4784     nrows       = *(buf_ri_k[k]);
4785     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4786     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
4787   }
4788 
4789   /* set values of ba */
4790   m = merge->rowmap->n;
4791   for (i=0; i<m; i++) {
4792     arow = owners[rank] + i;
4793     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4794     bnzi = bi[i+1] - bi[i];
4795     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4796 
4797     /* add local non-zero vals of this proc's seqmat into ba */
4798     anzi   = ai[arow+1] - ai[arow];
4799     aj     = a->j + ai[arow];
4800     aa     = a->a + ai[arow];
4801     nextaj = 0;
4802     for (j=0; nextaj<anzi; j++) {
4803       if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4804         ba_i[j] += aa[nextaj++];
4805       }
4806     }
4807 
4808     /* add received vals into ba */
4809     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
4810       /* i-th row */
4811       if (i == *nextrow[k]) {
4812         anzi   = *(nextai[k]+1) - *nextai[k];
4813         aj     = buf_rj[k] + *(nextai[k]);
4814         aa     = abuf_r[k] + *(nextai[k]);
4815         nextaj = 0;
4816         for (j=0; nextaj<anzi; j++) {
4817           if (*(bj_i + j) == aj[nextaj]) { /* bcol == acol */
4818             ba_i[j] += aa[nextaj++];
4819           }
4820         }
4821         nextrow[k]++; nextai[k]++;
4822       }
4823     }
4824     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4825   }
4826   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4827   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4828 
4829   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4830   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4831   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4832   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4833   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4834   PetscFunctionReturn(0);
4835 }
4836 
4837 extern PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat);
4838 
4839 #undef __FUNCT__
4840 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJSymbolic"
4841 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4842 {
4843   PetscErrorCode      ierr;
4844   Mat                 B_mpi;
4845   Mat_SeqAIJ          *a=(Mat_SeqAIJ*)seqmat->data;
4846   PetscMPIInt         size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4847   PetscInt            **buf_rj,**buf_ri,**buf_ri_k;
4848   PetscInt            M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4849   PetscInt            len,proc,*dnz,*onz,bs,cbs;
4850   PetscInt            k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4851   PetscInt            nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4852   MPI_Request         *si_waits,*sj_waits,*ri_waits,*rj_waits;
4853   MPI_Status          *status;
4854   PetscFreeSpaceList  free_space=NULL,current_space=NULL;
4855   PetscBT             lnkbt;
4856   Mat_Merge_SeqsToMPI *merge;
4857   PetscContainer      container;
4858 
4859   PetscFunctionBegin;
4860   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4861 
4862   /* make sure it is a PETSc comm */
4863   ierr = PetscCommDuplicate(comm,&comm,NULL);CHKERRQ(ierr);
4864   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4865   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4866 
4867   ierr = PetscNew(Mat_Merge_SeqsToMPI,&merge);CHKERRQ(ierr);
4868   ierr = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
4869 
4870   /* determine row ownership */
4871   /*---------------------------------------------------------*/
4872   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4873   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4874   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4875   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4876   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4877   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&len_si);CHKERRQ(ierr);
4878   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&merge->len_s);CHKERRQ(ierr);
4879 
4880   m      = merge->rowmap->n;
4881   owners = merge->rowmap->range;
4882 
4883   /* determine the number of messages to send, their lengths */
4884   /*---------------------------------------------------------*/
4885   len_s = merge->len_s;
4886 
4887   len          = 0; /* length of buf_si[] */
4888   merge->nsend = 0;
4889   for (proc=0; proc<size; proc++) {
4890     len_si[proc] = 0;
4891     if (proc == rank) {
4892       len_s[proc] = 0;
4893     } else {
4894       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4895       len_s[proc]  = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4896     }
4897     if (len_s[proc]) {
4898       merge->nsend++;
4899       nrows = 0;
4900       for (i=owners[proc]; i<owners[proc+1]; i++) {
4901         if (ai[i+1] > ai[i]) nrows++;
4902       }
4903       len_si[proc] = 2*(nrows+1);
4904       len         += len_si[proc];
4905     }
4906   }
4907 
4908   /* determine the number and length of messages to receive for ij-structure */
4909   /*-------------------------------------------------------------------------*/
4910   ierr = PetscGatherNumberOfMessages(comm,NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4911   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4912 
4913   /* post the Irecv of j-structure */
4914   /*-------------------------------*/
4915   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4916   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4917 
4918   /* post the Isend of j-structure */
4919   /*--------------------------------*/
4920   ierr = PetscMalloc2(merge->nsend,MPI_Request,&si_waits,merge->nsend,MPI_Request,&sj_waits);CHKERRQ(ierr);
4921 
4922   for (proc=0, k=0; proc<size; proc++) {
4923     if (!len_s[proc]) continue;
4924     i    = owners[proc];
4925     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4926     k++;
4927   }
4928 
4929   /* receives and sends of j-structure are complete */
4930   /*------------------------------------------------*/
4931   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4932   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4933 
4934   /* send and recv i-structure */
4935   /*---------------------------*/
4936   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4937   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4938 
4939   ierr   = PetscMalloc((len+1)*sizeof(PetscInt),&buf_s);CHKERRQ(ierr);
4940   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4941   for (proc=0,k=0; proc<size; proc++) {
4942     if (!len_s[proc]) continue;
4943     /* form outgoing message for i-structure:
4944          buf_si[0]:                 nrows to be sent
4945                [1:nrows]:           row index (global)
4946                [nrows+1:2*nrows+1]: i-structure index
4947     */
4948     /*-------------------------------------------*/
4949     nrows       = len_si[proc]/2 - 1;
4950     buf_si_i    = buf_si + nrows+1;
4951     buf_si[0]   = nrows;
4952     buf_si_i[0] = 0;
4953     nrows       = 0;
4954     for (i=owners[proc]; i<owners[proc+1]; i++) {
4955       anzi = ai[i+1] - ai[i];
4956       if (anzi) {
4957         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4958         buf_si[nrows+1]   = i-owners[proc]; /* local row index */
4959         nrows++;
4960       }
4961     }
4962     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4963     k++;
4964     buf_si += len_si[proc];
4965   }
4966 
4967   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4968   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4969 
4970   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4971   for (i=0; i<merge->nrecv; i++) {
4972     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);
4973   }
4974 
4975   ierr = PetscFree(len_si);CHKERRQ(ierr);
4976   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4977   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4978   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4979   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4980   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4981   ierr = PetscFree(status);CHKERRQ(ierr);
4982 
4983   /* compute a local seq matrix in each processor */
4984   /*----------------------------------------------*/
4985   /* allocate bi array and free space for accumulating nonzero column info */
4986   ierr  = PetscMalloc((m+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
4987   bi[0] = 0;
4988 
4989   /* create and initialize a linked list */
4990   nlnk = N+1;
4991   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4992 
4993   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4994   len  = ai[owners[rank+1]] - ai[owners[rank]];
4995   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4996 
4997   current_space = free_space;
4998 
4999   /* determine symbolic info for each local row */
5000   ierr = PetscMalloc3(merge->nrecv,PetscInt*,&buf_ri_k,merge->nrecv,PetscInt*,&nextrow,merge->nrecv,PetscInt*,&nextai);CHKERRQ(ierr);
5001 
5002   for (k=0; k<merge->nrecv; k++) {
5003     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
5004     nrows       = *buf_ri_k[k];
5005     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
5006     nextai[k]   = buf_ri_k[k] + (nrows + 1); /* poins to the next i-structure of k-th recved i-structure  */
5007   }
5008 
5009   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
5010   len  = 0;
5011   for (i=0; i<m; i++) {
5012     bnzi = 0;
5013     /* add local non-zero cols of this proc's seqmat into lnk */
5014     arow  = owners[rank] + i;
5015     anzi  = ai[arow+1] - ai[arow];
5016     aj    = a->j + ai[arow];
5017     ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
5018     bnzi += nlnk;
5019     /* add received col data into lnk */
5020     for (k=0; k<merge->nrecv; k++) { /* k-th received message */
5021       if (i == *nextrow[k]) { /* i-th row */
5022         anzi  = *(nextai[k]+1) - *nextai[k];
5023         aj    = buf_rj[k] + *nextai[k];
5024         ierr  = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
5025         bnzi += nlnk;
5026         nextrow[k]++; nextai[k]++;
5027       }
5028     }
5029     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
5030 
5031     /* if free space is not available, make more free space */
5032     if (current_space->local_remaining<bnzi) {
5033       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
5034       nspacedouble++;
5035     }
5036     /* copy data into free space, then initialize lnk */
5037     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
5038     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
5039 
5040     current_space->array           += bnzi;
5041     current_space->local_used      += bnzi;
5042     current_space->local_remaining -= bnzi;
5043 
5044     bi[i+1] = bi[i] + bnzi;
5045   }
5046 
5047   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
5048 
5049   ierr = PetscMalloc((bi[m]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
5050   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
5051   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
5052 
5053   /* create symbolic parallel matrix B_mpi */
5054   /*---------------------------------------*/
5055   ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
5056   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
5057   if (n==PETSC_DECIDE) {
5058     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
5059   } else {
5060     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5061   }
5062   ierr = MatSetBlockSizes(B_mpi,bs,cbs);CHKERRQ(ierr);
5063   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
5064   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
5065   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
5066   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
5067 
5068   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
5069   B_mpi->assembled    = PETSC_FALSE;
5070   B_mpi->ops->destroy = MatDestroy_MPIAIJ_SeqsToMPI;
5071   merge->bi           = bi;
5072   merge->bj           = bj;
5073   merge->buf_ri       = buf_ri;
5074   merge->buf_rj       = buf_rj;
5075   merge->coi          = NULL;
5076   merge->coj          = NULL;
5077   merge->owners_co    = NULL;
5078 
5079   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
5080 
5081   /* attach the supporting struct to B_mpi for reuse */
5082   ierr    = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
5083   ierr    = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
5084   ierr    = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
5085   ierr    = PetscContainerDestroy(&container);CHKERRQ(ierr);
5086   *mpimat = B_mpi;
5087 
5088   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
5089   PetscFunctionReturn(0);
5090 }
5091 
5092 #undef __FUNCT__
5093 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJ"
5094 /*@C
5095       MatCreateMPIAIJSumSeqAIJ - Creates a MPIAIJ matrix by adding sequential
5096                  matrices from each processor
5097 
5098     Collective on MPI_Comm
5099 
5100    Input Parameters:
5101 +    comm - the communicators the parallel matrix will live on
5102 .    seqmat - the input sequential matrices
5103 .    m - number of local rows (or PETSC_DECIDE)
5104 .    n - number of local columns (or PETSC_DECIDE)
5105 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5106 
5107    Output Parameter:
5108 .    mpimat - the parallel matrix generated
5109 
5110     Level: advanced
5111 
5112    Notes:
5113      The dimensions of the sequential matrix in each processor MUST be the same.
5114      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
5115      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
5116 @*/
5117 PetscErrorCode  MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
5118 {
5119   PetscErrorCode ierr;
5120   PetscMPIInt    size;
5121 
5122   PetscFunctionBegin;
5123   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
5124   if (size == 1) {
5125     ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
5126     if (scall == MAT_INITIAL_MATRIX) {
5127       ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
5128     } else {
5129       ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
5130     }
5131     ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
5132     PetscFunctionReturn(0);
5133   }
5134   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
5135   if (scall == MAT_INITIAL_MATRIX) {
5136     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
5137   }
5138   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
5139   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
5140   PetscFunctionReturn(0);
5141 }
5142 
5143 #undef __FUNCT__
5144 #define __FUNCT__ "MatMPIAIJGetLocalMat"
5145 /*@
5146      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
5147           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
5148           with MatGetSize()
5149 
5150     Not Collective
5151 
5152    Input Parameters:
5153 +    A - the matrix
5154 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5155 
5156    Output Parameter:
5157 .    A_loc - the local sequential matrix generated
5158 
5159     Level: developer
5160 
5161 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
5162 
5163 @*/
5164 PetscErrorCode  MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
5165 {
5166   PetscErrorCode ierr;
5167   Mat_MPIAIJ     *mpimat=(Mat_MPIAIJ*)A->data;
5168   Mat_SeqAIJ     *mat,*a=(Mat_SeqAIJ*)(mpimat->A)->data,*b=(Mat_SeqAIJ*)(mpimat->B)->data;
5169   PetscInt       *ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,*cmap=mpimat->garray;
5170   MatScalar      *aa=a->a,*ba=b->a,*cam;
5171   PetscScalar    *ca;
5172   PetscInt       am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
5173   PetscInt       *ci,*cj,col,ncols_d,ncols_o,jo;
5174   PetscBool      match;
5175 
5176   PetscFunctionBegin;
5177   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
5178   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
5179   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
5180   if (scall == MAT_INITIAL_MATRIX) {
5181     ierr  = PetscMalloc((1+am)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
5182     ci[0] = 0;
5183     for (i=0; i<am; i++) {
5184       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
5185     }
5186     ierr = PetscMalloc((1+ci[am])*sizeof(PetscInt),&cj);CHKERRQ(ierr);
5187     ierr = PetscMalloc((1+ci[am])*sizeof(PetscScalar),&ca);CHKERRQ(ierr);
5188     k    = 0;
5189     for (i=0; i<am; i++) {
5190       ncols_o = bi[i+1] - bi[i];
5191       ncols_d = ai[i+1] - ai[i];
5192       /* off-diagonal portion of A */
5193       for (jo=0; jo<ncols_o; jo++) {
5194         col = cmap[*bj];
5195         if (col >= cstart) break;
5196         cj[k]   = col; bj++;
5197         ca[k++] = *ba++;
5198       }
5199       /* diagonal portion of A */
5200       for (j=0; j<ncols_d; j++) {
5201         cj[k]   = cstart + *aj++;
5202         ca[k++] = *aa++;
5203       }
5204       /* off-diagonal portion of A */
5205       for (j=jo; j<ncols_o; j++) {
5206         cj[k]   = cmap[*bj++];
5207         ca[k++] = *ba++;
5208       }
5209     }
5210     /* put together the new matrix */
5211     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
5212     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5213     /* Since these are PETSc arrays, change flags to free them as necessary. */
5214     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
5215     mat->free_a  = PETSC_TRUE;
5216     mat->free_ij = PETSC_TRUE;
5217     mat->nonew   = 0;
5218   } else if (scall == MAT_REUSE_MATRIX) {
5219     mat=(Mat_SeqAIJ*)(*A_loc)->data;
5220     ci = mat->i; cj = mat->j; cam = mat->a;
5221     for (i=0; i<am; i++) {
5222       /* off-diagonal portion of A */
5223       ncols_o = bi[i+1] - bi[i];
5224       for (jo=0; jo<ncols_o; jo++) {
5225         col = cmap[*bj];
5226         if (col >= cstart) break;
5227         *cam++ = *ba++; bj++;
5228       }
5229       /* diagonal portion of A */
5230       ncols_d = ai[i+1] - ai[i];
5231       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
5232       /* off-diagonal portion of A */
5233       for (j=jo; j<ncols_o; j++) {
5234         *cam++ = *ba++; bj++;
5235       }
5236     }
5237   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
5238   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
5239   PetscFunctionReturn(0);
5240 }
5241 
5242 #undef __FUNCT__
5243 #define __FUNCT__ "MatMPIAIJGetLocalMatCondensed"
5244 /*@C
5245      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MPIAIJ matrix by taking all its local rows and NON-ZERO columns
5246 
5247     Not Collective
5248 
5249    Input Parameters:
5250 +    A - the matrix
5251 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5252 -    row, col - index sets of rows and columns to extract (or NULL)
5253 
5254    Output Parameter:
5255 .    A_loc - the local sequential matrix generated
5256 
5257     Level: developer
5258 
5259 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
5260 
5261 @*/
5262 PetscErrorCode  MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
5263 {
5264   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5265   PetscErrorCode ierr;
5266   PetscInt       i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
5267   IS             isrowa,iscola;
5268   Mat            *aloc;
5269   PetscBool      match;
5270 
5271   PetscFunctionBegin;
5272   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
5273   if (!match) SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
5274   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5275   if (!row) {
5276     start = A->rmap->rstart; end = A->rmap->rend;
5277     ierr  = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
5278   } else {
5279     isrowa = *row;
5280   }
5281   if (!col) {
5282     start = A->cmap->rstart;
5283     cmap  = a->garray;
5284     nzA   = a->A->cmap->n;
5285     nzB   = a->B->cmap->n;
5286     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
5287     ncols = 0;
5288     for (i=0; i<nzB; i++) {
5289       if (cmap[i] < start) idx[ncols++] = cmap[i];
5290       else break;
5291     }
5292     imark = i;
5293     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
5294     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
5295     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
5296   } else {
5297     iscola = *col;
5298   }
5299   if (scall != MAT_INITIAL_MATRIX) {
5300     ierr    = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
5301     aloc[0] = *A_loc;
5302   }
5303   ierr   = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
5304   *A_loc = aloc[0];
5305   ierr   = PetscFree(aloc);CHKERRQ(ierr);
5306   if (!row) {
5307     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
5308   }
5309   if (!col) {
5310     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
5311   }
5312   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5313   PetscFunctionReturn(0);
5314 }
5315 
5316 #undef __FUNCT__
5317 #define __FUNCT__ "MatGetBrowsOfAcols"
5318 /*@C
5319     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
5320 
5321     Collective on Mat
5322 
5323    Input Parameters:
5324 +    A,B - the matrices in mpiaij format
5325 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5326 -    rowb, colb - index sets of rows and columns of B to extract (or NULL)
5327 
5328    Output Parameter:
5329 +    rowb, colb - index sets of rows and columns of B to extract
5330 -    B_seq - the sequential matrix generated
5331 
5332     Level: developer
5333 
5334 @*/
5335 PetscErrorCode  MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
5336 {
5337   Mat_MPIAIJ     *a=(Mat_MPIAIJ*)A->data;
5338   PetscErrorCode ierr;
5339   PetscInt       *idx,i,start,ncols,nzA,nzB,*cmap,imark;
5340   IS             isrowb,iscolb;
5341   Mat            *bseq=NULL;
5342 
5343   PetscFunctionBegin;
5344   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5345     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);
5346   }
5347   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5348 
5349   if (scall == MAT_INITIAL_MATRIX) {
5350     start = A->cmap->rstart;
5351     cmap  = a->garray;
5352     nzA   = a->A->cmap->n;
5353     nzB   = a->B->cmap->n;
5354     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
5355     ncols = 0;
5356     for (i=0; i<nzB; i++) {  /* row < local row index */
5357       if (cmap[i] < start) idx[ncols++] = cmap[i];
5358       else break;
5359     }
5360     imark = i;
5361     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
5362     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5363     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
5364     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
5365   } else {
5366     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5367     isrowb  = *rowb; iscolb = *colb;
5368     ierr    = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
5369     bseq[0] = *B_seq;
5370   }
5371   ierr   = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
5372   *B_seq = bseq[0];
5373   ierr   = PetscFree(bseq);CHKERRQ(ierr);
5374   if (!rowb) {
5375     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
5376   } else {
5377     *rowb = isrowb;
5378   }
5379   if (!colb) {
5380     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
5381   } else {
5382     *colb = iscolb;
5383   }
5384   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5385   PetscFunctionReturn(0);
5386 }
5387 
5388 #undef __FUNCT__
5389 #define __FUNCT__ "MatGetBrowsOfAoCols_MPIAIJ"
5390 /*
5391     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
5392     of the OFF-DIAGONAL portion of local A
5393 
5394     Collective on Mat
5395 
5396    Input Parameters:
5397 +    A,B - the matrices in mpiaij format
5398 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5399 
5400    Output Parameter:
5401 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or NULL)
5402 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or NULL)
5403 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or NULL)
5404 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
5405 
5406     Level: developer
5407 
5408 */
5409 PetscErrorCode  MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
5410 {
5411   VecScatter_MPI_General *gen_to,*gen_from;
5412   PetscErrorCode         ierr;
5413   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
5414   Mat_SeqAIJ             *b_oth;
5415   VecScatter             ctx =a->Mvctx;
5416   MPI_Comm               comm;
5417   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
5418   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
5419   PetscScalar            *rvalues,*svalues;
5420   MatScalar              *b_otha,*bufa,*bufA;
5421   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
5422   MPI_Request            *rwaits = NULL,*swaits = NULL;
5423   MPI_Status             *sstatus,rstatus;
5424   PetscMPIInt            jj;
5425   PetscInt               *cols,sbs,rbs;
5426   PetscScalar            *vals;
5427 
5428   PetscFunctionBegin;
5429   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
5430   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend) {
5431     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);
5432   }
5433   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5434   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
5435 
5436   gen_to   = (VecScatter_MPI_General*)ctx->todata;
5437   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
5438   rvalues  = gen_from->values; /* holds the length of receiving row */
5439   svalues  = gen_to->values;   /* holds the length of sending row */
5440   nrecvs   = gen_from->n;
5441   nsends   = gen_to->n;
5442 
5443   ierr    = PetscMalloc2(nrecvs,MPI_Request,&rwaits,nsends,MPI_Request,&swaits);CHKERRQ(ierr);
5444   srow    = gen_to->indices;    /* local row index to be sent */
5445   sstarts = gen_to->starts;
5446   sprocs  = gen_to->procs;
5447   sstatus = gen_to->sstatus;
5448   sbs     = gen_to->bs;
5449   rstarts = gen_from->starts;
5450   rprocs  = gen_from->procs;
5451   rbs     = gen_from->bs;
5452 
5453   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5454   if (scall == MAT_INITIAL_MATRIX) {
5455     /* i-array */
5456     /*---------*/
5457     /*  post receives */
5458     for (i=0; i<nrecvs; i++) {
5459       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5460       nrows  = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
5461       ierr   = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5462     }
5463 
5464     /* pack the outgoing message */
5465     ierr = PetscMalloc2(nsends+1,PetscInt,&sstartsj,nrecvs+1,PetscInt,&rstartsj);CHKERRQ(ierr);
5466 
5467     sstartsj[0] = 0;
5468     rstartsj[0] = 0;
5469     len         = 0; /* total length of j or a array to be sent */
5470     k           = 0;
5471     for (i=0; i<nsends; i++) {
5472       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
5473       nrows  = sstarts[i+1]-sstarts[i]; /* num of block rows */
5474       for (j=0; j<nrows; j++) {
5475         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5476         for (l=0; l<sbs; l++) {
5477           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr); /* rowlength */
5478 
5479           rowlen[j*sbs+l] = ncols;
5480 
5481           len += ncols;
5482           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,NULL,NULL);CHKERRQ(ierr);
5483         }
5484         k++;
5485       }
5486       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5487 
5488       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5489     }
5490     /* recvs and sends of i-array are completed */
5491     i = nrecvs;
5492     while (i--) {
5493       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5494     }
5495     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5496 
5497     /* allocate buffers for sending j and a arrays */
5498     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&bufj);CHKERRQ(ierr);
5499     ierr = PetscMalloc((len+1)*sizeof(PetscScalar),&bufa);CHKERRQ(ierr);
5500 
5501     /* create i-array of B_oth */
5502     ierr = PetscMalloc((aBn+2)*sizeof(PetscInt),&b_othi);CHKERRQ(ierr);
5503 
5504     b_othi[0] = 0;
5505     len       = 0; /* total length of j or a array to be received */
5506     k         = 0;
5507     for (i=0; i<nrecvs; i++) {
5508       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5509       nrows  = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
5510       for (j=0; j<nrows; j++) {
5511         b_othi[k+1] = b_othi[k] + rowlen[j];
5512         len        += rowlen[j]; k++;
5513       }
5514       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5515     }
5516 
5517     /* allocate space for j and a arrrays of B_oth */
5518     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(PetscInt),&b_othj);CHKERRQ(ierr);
5519     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(MatScalar),&b_otha);CHKERRQ(ierr);
5520 
5521     /* j-array */
5522     /*---------*/
5523     /*  post receives of j-array */
5524     for (i=0; i<nrecvs; i++) {
5525       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5526       ierr  = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5527     }
5528 
5529     /* pack the outgoing message j-array */
5530     k = 0;
5531     for (i=0; i<nsends; i++) {
5532       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5533       bufJ  = bufj+sstartsj[i];
5534       for (j=0; j<nrows; j++) {
5535         row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5536         for (ll=0; ll<sbs; ll++) {
5537           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5538           for (l=0; l<ncols; l++) {
5539             *bufJ++ = cols[l];
5540           }
5541           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,NULL);CHKERRQ(ierr);
5542         }
5543       }
5544       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5545     }
5546 
5547     /* recvs and sends of j-array are completed */
5548     i = nrecvs;
5549     while (i--) {
5550       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5551     }
5552     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5553   } else if (scall == MAT_REUSE_MATRIX) {
5554     sstartsj = *startsj_s;
5555     rstartsj = *startsj_r;
5556     bufa     = *bufa_ptr;
5557     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
5558     b_otha   = b_oth->a;
5559   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
5560 
5561   /* a-array */
5562   /*---------*/
5563   /*  post receives of a-array */
5564   for (i=0; i<nrecvs; i++) {
5565     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5566     ierr  = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5567   }
5568 
5569   /* pack the outgoing message a-array */
5570   k = 0;
5571   for (i=0; i<nsends; i++) {
5572     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5573     bufA  = bufa+sstartsj[i];
5574     for (j=0; j<nrows; j++) {
5575       row = srow[k++] + B->rmap->range[rank];  /* global row idx */
5576       for (ll=0; ll<sbs; ll++) {
5577         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5578         for (l=0; l<ncols; l++) {
5579           *bufA++ = vals[l];
5580         }
5581         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,NULL,&vals);CHKERRQ(ierr);
5582       }
5583     }
5584     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5585   }
5586   /* recvs and sends of a-array are completed */
5587   i = nrecvs;
5588   while (i--) {
5589     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5590   }
5591   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5592   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
5593 
5594   if (scall == MAT_INITIAL_MATRIX) {
5595     /* put together the new matrix */
5596     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
5597 
5598     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5599     /* Since these are PETSc arrays, change flags to free them as necessary. */
5600     b_oth          = (Mat_SeqAIJ*)(*B_oth)->data;
5601     b_oth->free_a  = PETSC_TRUE;
5602     b_oth->free_ij = PETSC_TRUE;
5603     b_oth->nonew   = 0;
5604 
5605     ierr = PetscFree(bufj);CHKERRQ(ierr);
5606     if (!startsj_s || !bufa_ptr) {
5607       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
5608       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
5609     } else {
5610       *startsj_s = sstartsj;
5611       *startsj_r = rstartsj;
5612       *bufa_ptr  = bufa;
5613     }
5614   }
5615   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5616   PetscFunctionReturn(0);
5617 }
5618 
5619 #undef __FUNCT__
5620 #define __FUNCT__ "MatGetCommunicationStructs"
5621 /*@C
5622   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
5623 
5624   Not Collective
5625 
5626   Input Parameters:
5627 . A - The matrix in mpiaij format
5628 
5629   Output Parameter:
5630 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
5631 . colmap - A map from global column index to local index into lvec
5632 - multScatter - A scatter from the argument of a matrix-vector product to lvec
5633 
5634   Level: developer
5635 
5636 @*/
5637 #if defined(PETSC_USE_CTABLE)
5638 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
5639 #else
5640 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
5641 #endif
5642 {
5643   Mat_MPIAIJ *a;
5644 
5645   PetscFunctionBegin;
5646   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
5647   PetscValidPointer(lvec, 2);
5648   PetscValidPointer(colmap, 3);
5649   PetscValidPointer(multScatter, 4);
5650   a = (Mat_MPIAIJ*) A->data;
5651   if (lvec) *lvec = a->lvec;
5652   if (colmap) *colmap = a->colmap;
5653   if (multScatter) *multScatter = a->Mvctx;
5654   PetscFunctionReturn(0);
5655 }
5656 
5657 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat,MatType,MatReuse,Mat*);
5658 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJPERM(Mat,MatType,MatReuse,Mat*);
5659 PETSC_EXTERN PetscErrorCode MatConvert_MPIAIJ_MPISBAIJ(Mat,MatType,MatReuse,Mat*);
5660 
5661 #undef __FUNCT__
5662 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
5663 /*
5664     Computes (B'*A')' since computing B*A directly is untenable
5665 
5666                n                       p                          p
5667         (              )       (              )         (                  )
5668       m (      A       )  *  n (       B      )   =   m (         C        )
5669         (              )       (              )         (                  )
5670 
5671 */
5672 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
5673 {
5674   PetscErrorCode ierr;
5675   Mat            At,Bt,Ct;
5676 
5677   PetscFunctionBegin;
5678   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
5679   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
5680   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
5681   ierr = MatDestroy(&At);CHKERRQ(ierr);
5682   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
5683   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
5684   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
5685   PetscFunctionReturn(0);
5686 }
5687 
5688 #undef __FUNCT__
5689 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
5690 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
5691 {
5692   PetscErrorCode ierr;
5693   PetscInt       m=A->rmap->n,n=B->cmap->n;
5694   Mat            Cmat;
5695 
5696   PetscFunctionBegin;
5697   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);
5698   ierr = MatCreate(PetscObjectComm((PetscObject)A),&Cmat);CHKERRQ(ierr);
5699   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5700   ierr = MatSetBlockSizes(Cmat,A->rmap->bs,B->cmap->bs);CHKERRQ(ierr);
5701   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
5702   ierr = MatMPIDenseSetPreallocation(Cmat,NULL);CHKERRQ(ierr);
5703   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5704   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5705 
5706   Cmat->ops->matmultnumeric = MatMatMultNumeric_MPIDense_MPIAIJ;
5707 
5708   *C = Cmat;
5709   PetscFunctionReturn(0);
5710 }
5711 
5712 /* ----------------------------------------------------------------*/
5713 #undef __FUNCT__
5714 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
5715 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
5716 {
5717   PetscErrorCode ierr;
5718 
5719   PetscFunctionBegin;
5720   if (scall == MAT_INITIAL_MATRIX) {
5721     ierr = PetscLogEventBegin(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5722     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
5723     ierr = PetscLogEventEnd(MAT_MatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
5724   }
5725   ierr = PetscLogEventBegin(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5726   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
5727   ierr = PetscLogEventEnd(MAT_MatMultNumeric,A,B,0,0);CHKERRQ(ierr);
5728   PetscFunctionReturn(0);
5729 }
5730 
5731 #if defined(PETSC_HAVE_MUMPS)
5732 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_mumps(Mat,MatFactorType,Mat*);
5733 #endif
5734 #if defined(PETSC_HAVE_PASTIX)
5735 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
5736 #endif
5737 #if defined(PETSC_HAVE_SUPERLU_DIST)
5738 PETSC_EXTERN PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
5739 #endif
5740 #if defined(PETSC_HAVE_CLIQUE)
5741 PETSC_EXTERN PetscErrorCode MatGetFactor_aij_clique(Mat,MatFactorType,Mat*);
5742 #endif
5743 
5744 /*MC
5745    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
5746 
5747    Options Database Keys:
5748 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
5749 
5750   Level: beginner
5751 
5752 .seealso: MatCreateAIJ()
5753 M*/
5754 
5755 #undef __FUNCT__
5756 #define __FUNCT__ "MatCreate_MPIAIJ"
5757 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJ(Mat B)
5758 {
5759   Mat_MPIAIJ     *b;
5760   PetscErrorCode ierr;
5761   PetscMPIInt    size;
5762 
5763   PetscFunctionBegin;
5764   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)B),&size);CHKERRQ(ierr);
5765 
5766   ierr          = PetscNewLog(B,Mat_MPIAIJ,&b);CHKERRQ(ierr);
5767   B->data       = (void*)b;
5768   ierr          = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
5769   B->assembled  = PETSC_FALSE;
5770   B->insertmode = NOT_SET_VALUES;
5771   b->size       = size;
5772 
5773   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)B),&b->rank);CHKERRQ(ierr);
5774 
5775   /* build cache for off array entries formed */
5776   ierr = MatStashCreate_Private(PetscObjectComm((PetscObject)B),1,&B->stash);CHKERRQ(ierr);
5777 
5778   b->donotstash  = PETSC_FALSE;
5779   b->colmap      = 0;
5780   b->garray      = 0;
5781   b->roworiented = PETSC_TRUE;
5782 
5783   /* stuff used for matrix vector multiply */
5784   b->lvec  = NULL;
5785   b->Mvctx = NULL;
5786 
5787   /* stuff for MatGetRow() */
5788   b->rowindices   = 0;
5789   b->rowvalues    = 0;
5790   b->getrowactive = PETSC_FALSE;
5791 
5792   /* flexible pointer used in CUSP/CUSPARSE classes */
5793   b->spptr = NULL;
5794 
5795 #if defined(PETSC_HAVE_MUMPS)
5796   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_mumps_C",MatGetFactor_aij_mumps);CHKERRQ(ierr);
5797 #endif
5798 #if defined(PETSC_HAVE_PASTIX)
5799   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_pastix_C",MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
5800 #endif
5801 #if defined(PETSC_HAVE_SUPERLU_DIST)
5802   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_superlu_dist_C",MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
5803 #endif
5804 #if defined(PETSC_HAVE_CLIQUE)
5805   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetFactor_clique_C",MatGetFactor_aij_clique);CHKERRQ(ierr);
5806 #endif
5807   ierr = PetscObjectComposeFunction((PetscObject)B,"MatStoreValues_C",MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5808   ierr = PetscObjectComposeFunction((PetscObject)B,"MatRetrieveValues_C",MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5809   ierr = PetscObjectComposeFunction((PetscObject)B,"MatGetDiagonalBlock_C",MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5810   ierr = PetscObjectComposeFunction((PetscObject)B,"MatIsTranspose_C",MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5811   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5812   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5813   ierr = PetscObjectComposeFunction((PetscObject)B,"MatDiagonalScaleLocal_C",MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5814   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
5815   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5816   ierr = PetscObjectComposeFunction((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5817   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5818   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5819   ierr = PetscObjectComposeFunction((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5820   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5821   PetscFunctionReturn(0);
5822 }
5823 
5824 #undef __FUNCT__
5825 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5826 /*@
5827      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5828          and "off-diagonal" part of the matrix in CSR format.
5829 
5830    Collective on MPI_Comm
5831 
5832    Input Parameters:
5833 +  comm - MPI communicator
5834 .  m - number of local rows (Cannot be PETSC_DECIDE)
5835 .  n - This value should be the same as the local size used in creating the
5836        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5837        calculated if N is given) For square matrices n is almost always m.
5838 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5839 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5840 .   i - row indices for "diagonal" portion of matrix
5841 .   j - column indices
5842 .   a - matrix values
5843 .   oi - row indices for "off-diagonal" portion of matrix
5844 .   oj - column indices
5845 -   oa - matrix values
5846 
5847    Output Parameter:
5848 .   mat - the matrix
5849 
5850    Level: advanced
5851 
5852    Notes:
5853        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5854        must free the arrays once the matrix has been destroyed and not before.
5855 
5856        The i and j indices are 0 based
5857 
5858        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5859 
5860        This sets local rows and cannot be used to set off-processor values.
5861 
5862        Use of this routine is discouraged because it is inflexible and cumbersome to use. It is extremely rare that a
5863        legacy application natively assembles into exactly this split format. The code to do so is nontrivial and does
5864        not easily support in-place reassembly. It is recommended to use MatSetValues() (or a variant thereof) because
5865        the resulting assembly is easier to implement, will work with any matrix format, and the user does not have to
5866        keep track of the underlying array. Use MatSetOption(A,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE) to disable all
5867        communication if it is known that only local entries will be set.
5868 
5869 .keywords: matrix, aij, compressed row, sparse, parallel
5870 
5871 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5872           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5873 @*/
5874 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)
5875 {
5876   PetscErrorCode ierr;
5877   Mat_MPIAIJ     *maij;
5878 
5879   PetscFunctionBegin;
5880   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5881   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5882   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5883   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5884   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5885   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5886   maij = (Mat_MPIAIJ*) (*mat)->data;
5887 
5888   (*mat)->preallocated = PETSC_TRUE;
5889 
5890   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5891   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5892 
5893   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5894   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5895 
5896   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5897   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5898   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5899   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5900 
5901   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5902   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5903   ierr = MatSetOption(*mat,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
5904   PetscFunctionReturn(0);
5905 }
5906 
5907 /*
5908     Special version for direct calls from Fortran
5909 */
5910 #include <petsc-private/fortranimpl.h>
5911 
5912 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5913 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5914 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5915 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5916 #endif
5917 
5918 /* Change these macros so can be used in void function */
5919 #undef CHKERRQ
5920 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5921 #undef SETERRQ2
5922 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5923 #undef SETERRQ3
5924 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5925 #undef SETERRQ
5926 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5927 
5928 #undef __FUNCT__
5929 #define __FUNCT__ "matsetvaluesmpiaij_"
5930 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)
5931 {
5932   Mat            mat  = *mmat;
5933   PetscInt       m    = *mm, n = *mn;
5934   InsertMode     addv = *maddv;
5935   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
5936   PetscScalar    value;
5937   PetscErrorCode ierr;
5938 
5939   MatCheckPreallocated(mat,1);
5940   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
5941 
5942 #if defined(PETSC_USE_DEBUG)
5943   else if (mat->insertmode != addv) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5944 #endif
5945   {
5946     PetscInt  i,j,rstart  = mat->rmap->rstart,rend = mat->rmap->rend;
5947     PetscInt  cstart      = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5948     PetscBool roworiented = aij->roworiented;
5949 
5950     /* Some Variables required in the macro */
5951     Mat        A                 = aij->A;
5952     Mat_SeqAIJ *a                = (Mat_SeqAIJ*)A->data;
5953     PetscInt   *aimax            = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5954     MatScalar  *aa               = a->a;
5955     PetscBool  ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES)) ? PETSC_TRUE : PETSC_FALSE);
5956     Mat        B                 = aij->B;
5957     Mat_SeqAIJ *b                = (Mat_SeqAIJ*)B->data;
5958     PetscInt   *bimax            = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5959     MatScalar  *ba               = b->a;
5960 
5961     PetscInt  *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5962     PetscInt  nonew = a->nonew;
5963     MatScalar *ap1,*ap2;
5964 
5965     PetscFunctionBegin;
5966     for (i=0; i<m; i++) {
5967       if (im[i] < 0) continue;
5968 #if defined(PETSC_USE_DEBUG)
5969       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);
5970 #endif
5971       if (im[i] >= rstart && im[i] < rend) {
5972         row      = im[i] - rstart;
5973         lastcol1 = -1;
5974         rp1      = aj + ai[row];
5975         ap1      = aa + ai[row];
5976         rmax1    = aimax[row];
5977         nrow1    = ailen[row];
5978         low1     = 0;
5979         high1    = nrow1;
5980         lastcol2 = -1;
5981         rp2      = bj + bi[row];
5982         ap2      = ba + bi[row];
5983         rmax2    = bimax[row];
5984         nrow2    = bilen[row];
5985         low2     = 0;
5986         high2    = nrow2;
5987 
5988         for (j=0; j<n; j++) {
5989           if (roworiented) value = v[i*n+j];
5990           else value = v[i+j*m];
5991           if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5992           if (in[j] >= cstart && in[j] < cend) {
5993             col = in[j] - cstart;
5994             MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5995           } else if (in[j] < 0) continue;
5996 #if defined(PETSC_USE_DEBUG)
5997           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);
5998 #endif
5999           else {
6000             if (mat->was_assembled) {
6001               if (!aij->colmap) {
6002                 ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
6003               }
6004 #if defined(PETSC_USE_CTABLE)
6005               ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
6006               col--;
6007 #else
6008               col = aij->colmap[in[j]] - 1;
6009 #endif
6010               if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
6011                 ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
6012                 col  =  in[j];
6013                 /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
6014                 B     = aij->B;
6015                 b     = (Mat_SeqAIJ*)B->data;
6016                 bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
6017                 rp2   = bj + bi[row];
6018                 ap2   = ba + bi[row];
6019                 rmax2 = bimax[row];
6020                 nrow2 = bilen[row];
6021                 low2  = 0;
6022                 high2 = nrow2;
6023                 bm    = aij->B->rmap->n;
6024                 ba    = b->a;
6025               }
6026             } else col = in[j];
6027             MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
6028           }
6029         }
6030       } else if (!aij->donotstash) {
6031         if (roworiented) {
6032           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
6033         } else {
6034           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
6035         }
6036       }
6037     }
6038   }
6039   PetscFunctionReturnVoid();
6040 }
6041 
6042