xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 50d2b0a4ce699e6d765398cd415fd84ad3b760ca)
1 #define PETSCMAT_DLL
2 
3 #include "../src/mat/impls/aij/mpi/mpiaij.h"   /*I "petscmat.h" I*/
4 #include "../src/inline/spops.h"
5 
6 #undef __FUNCT__
7 #define __FUNCT__ "MatDistribute_MPIAIJ"
8 /*
9     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
10     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
11 
12     Only for square matrices
13 */
14 PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
15 {
16   PetscMPIInt    rank,size;
17   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz,*gmataj,cnt,row,*ld;
18   PetscErrorCode ierr;
19   Mat            mat;
20   Mat_SeqAIJ     *gmata;
21   PetscMPIInt    tag;
22   MPI_Status     status;
23   PetscTruth     aij;
24   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
25 
26   PetscFunctionBegin;
27   CHKMEMQ;
28   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
29   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
30   if (!rank) {
31     ierr = PetscTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
32     if (!aij) SETERRQ1(PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
33   }
34   if (reuse == MAT_INITIAL_MATRIX) {
35     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
36     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
37     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
38     ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
39     ierr = PetscMalloc2(m,PetscInt,&dlens,m,PetscInt,&olens);CHKERRQ(ierr);
40     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
41     rowners[0] = 0;
42     for (i=2; i<=size; i++) {
43       rowners[i] += rowners[i-1];
44     }
45     rstart = rowners[rank];
46     rend   = rowners[rank+1];
47     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
48     if (!rank) {
49       gmata = (Mat_SeqAIJ*) gmat->data;
50       /* send row lengths to all processors */
51       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
52       for (i=1; i<size; i++) {
53 	ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
54       }
55       /* determine number diagonal and off-diagonal counts */
56       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
57       ierr = PetscMalloc(m*sizeof(PetscInt),&ld);CHKERRQ(ierr);
58       ierr = PetscMemzero(ld,m*sizeof(PetscInt));CHKERRQ(ierr);
59       jj = 0;
60       for (i=0; i<m; i++) {
61 	for (j=0; j<dlens[i]; j++) {
62           if (gmata->j[jj] < rstart) ld[i]++;
63 	  if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
64 	  jj++;
65 	}
66       }
67       /* send column indices to other processes */
68       for (i=1; i<size; i++) {
69 	nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
70 	ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
71 	ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
72       }
73 
74       /* send numerical values to other processes */
75       for (i=1; i<size; i++) {
76         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
77         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
78       }
79       gmataa = gmata->a;
80       gmataj = gmata->j;
81 
82     } else {
83       /* receive row lengths */
84       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
85       /* receive column indices */
86       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
87       ierr = PetscMalloc2(nz,PetscScalar,&gmataa,nz,PetscInt,&gmataj);CHKERRQ(ierr);
88       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
89       /* determine number diagonal and off-diagonal counts */
90       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
91       ierr = PetscMalloc(m*sizeof(PetscInt),&ld);CHKERRQ(ierr);
92       ierr = PetscMemzero(ld,m*sizeof(PetscInt));CHKERRQ(ierr);
93       jj = 0;
94       for (i=0; i<m; i++) {
95 	for (j=0; j<dlens[i]; j++) {
96           if (gmataj[jj] < rstart) ld[i]++;
97 	  if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
98 	  jj++;
99 	}
100       }
101       /* receive numerical values */
102       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
103       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
104     }
105     /* set preallocation */
106     for (i=0; i<m; i++) {
107       dlens[i] -= olens[i];
108     }
109     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
110     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
111 
112     for (i=0; i<m; i++) {
113       dlens[i] += olens[i];
114     }
115     cnt  = 0;
116     for (i=0; i<m; i++) {
117       row  = rstart + i;
118       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
119       cnt += dlens[i];
120     }
121     if (rank) {
122       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
123     }
124     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
125     ierr = PetscFree(rowners);CHKERRQ(ierr);
126     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
127     *inmat = mat;
128   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
129     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
130     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
131     mat   = *inmat;
132     ierr  = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
133     if (!rank) {
134       /* send numerical values to other processes */
135       gmata = (Mat_SeqAIJ*) gmat->data;
136       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
137       gmataa = gmata->a;
138       for (i=1; i<size; i++) {
139         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
140         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
141       }
142       nz   = gmata->i[rowners[1]]-gmata->i[rowners[0]];
143     } else {
144       /* receive numerical values from process 0*/
145       nz   = Ad->nz + Ao->nz;
146       ierr = PetscMalloc(nz*sizeof(PetscScalar),&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
147       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
148     }
149     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
150     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
151     ad = Ad->a;
152     ao = Ao->a;
153     if (mat->rmap->n) {
154       i  = 0;
155       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
156       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
157     }
158     for (i=1; i<mat->rmap->n; i++) {
159       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;
160       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
161     }
162     i--;
163     if (mat->rmap->n) {
164       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
165     }
166     if (rank) {
167       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
168     }
169   }
170   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
171   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
172   CHKMEMQ;
173   PetscFunctionReturn(0);
174 }
175 
176 /*
177   Local utility routine that creates a mapping from the global column
178 number to the local number in the off-diagonal part of the local
179 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
180 a slightly higher hash table cost; without it it is not scalable (each processor
181 has an order N integer array but is fast to acess.
182 */
183 #undef __FUNCT__
184 #define __FUNCT__ "CreateColmap_MPIAIJ_Private"
185 PetscErrorCode CreateColmap_MPIAIJ_Private(Mat mat)
186 {
187   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
188   PetscErrorCode ierr;
189   PetscInt       n = aij->B->cmap->n,i;
190 
191   PetscFunctionBegin;
192 #if defined (PETSC_USE_CTABLE)
193   ierr = PetscTableCreate(n,&aij->colmap);CHKERRQ(ierr);
194   for (i=0; i<n; i++){
195     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1);CHKERRQ(ierr);
196   }
197 #else
198   ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscInt),&aij->colmap);CHKERRQ(ierr);
199   ierr = PetscLogObjectMemory(mat,mat->cmap->N*sizeof(PetscInt));CHKERRQ(ierr);
200   ierr = PetscMemzero(aij->colmap,mat->cmap->N*sizeof(PetscInt));CHKERRQ(ierr);
201   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
202 #endif
203   PetscFunctionReturn(0);
204 }
205 
206 
207 #define CHUNKSIZE   15
208 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv) \
209 { \
210     if (col <= lastcol1) low1 = 0; else high1 = nrow1; \
211     lastcol1 = col;\
212     while (high1-low1 > 5) { \
213       t = (low1+high1)/2; \
214       if (rp1[t] > col) high1 = t; \
215       else             low1  = t; \
216     } \
217       for (_i=low1; _i<high1; _i++) { \
218         if (rp1[_i] > col) break; \
219         if (rp1[_i] == col) { \
220           if (addv == ADD_VALUES) ap1[_i] += value;   \
221           else                    ap1[_i] = value; \
222           goto a_noinsert; \
223         } \
224       }  \
225       if (value == 0.0 && ignorezeroentries) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
226       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}		\
227       if (nonew == -1) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
228       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
229       N = nrow1++ - 1; a->nz++; high1++; \
230       /* shift up all the later entries in this row */ \
231       for (ii=N; ii>=_i; ii--) { \
232         rp1[ii+1] = rp1[ii]; \
233         ap1[ii+1] = ap1[ii]; \
234       } \
235       rp1[_i] = col;  \
236       ap1[_i] = value;  \
237       a_noinsert: ; \
238       ailen[row] = nrow1; \
239 }
240 
241 
242 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv) \
243 { \
244     if (col <= lastcol2) low2 = 0; else high2 = nrow2; \
245     lastcol2 = col;\
246     while (high2-low2 > 5) { \
247       t = (low2+high2)/2; \
248       if (rp2[t] > col) high2 = t; \
249       else             low2  = t; \
250     } \
251     for (_i=low2; _i<high2; _i++) {		\
252       if (rp2[_i] > col) break;			\
253       if (rp2[_i] == col) {			      \
254 	if (addv == ADD_VALUES) ap2[_i] += value;     \
255 	else                    ap2[_i] = value;      \
256 	goto b_noinsert;			      \
257       }						      \
258     }							      \
259     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
260     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}		\
261     if (nonew == -1) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
262     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
263     N = nrow2++ - 1; b->nz++; high2++;					\
264     /* shift up all the later entries in this row */			\
265     for (ii=N; ii>=_i; ii--) {						\
266       rp2[ii+1] = rp2[ii];						\
267       ap2[ii+1] = ap2[ii];						\
268     }									\
269     rp2[_i] = col;							\
270     ap2[_i] = value;							\
271     b_noinsert: ;								\
272     bilen[row] = nrow2;							\
273 }
274 
275 #undef __FUNCT__
276 #define __FUNCT__ "MatSetValuesRow_MPIAIJ"
277 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
278 {
279   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
280   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
281   PetscErrorCode ierr;
282   PetscInt       l,*garray = mat->garray,diag;
283 
284   PetscFunctionBegin;
285   /* code only works for square matrices A */
286 
287   /* find size of row to the left of the diagonal part */
288   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
289   row  = row - diag;
290   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
291     if (garray[b->j[b->i[row]+l]] > diag) break;
292   }
293   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
294 
295   /* diagonal part */
296   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
297 
298   /* right of diagonal part */
299   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);
300   PetscFunctionReturn(0);
301 }
302 
303 #undef __FUNCT__
304 #define __FUNCT__ "MatSetValues_MPIAIJ"
305 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
306 {
307   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
308   PetscScalar    value;
309   PetscErrorCode ierr;
310   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
311   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
312   PetscTruth     roworiented = aij->roworiented;
313 
314   /* Some Variables required in the macro */
315   Mat            A = aij->A;
316   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
317   PetscInt       *aimax = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
318   MatScalar      *aa = a->a;
319   PetscTruth     ignorezeroentries = a->ignorezeroentries;
320   Mat            B = aij->B;
321   Mat_SeqAIJ     *b = (Mat_SeqAIJ*)B->data;
322   PetscInt       *bimax = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
323   MatScalar      *ba = b->a;
324 
325   PetscInt       *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
326   PetscInt       nonew = a->nonew;
327   MatScalar      *ap1,*ap2;
328 
329   PetscFunctionBegin;
330   for (i=0; i<m; i++) {
331     if (im[i] < 0) continue;
332 #if defined(PETSC_USE_DEBUG)
333     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
334 #endif
335     if (im[i] >= rstart && im[i] < rend) {
336       row      = im[i] - rstart;
337       lastcol1 = -1;
338       rp1      = aj + ai[row];
339       ap1      = aa + ai[row];
340       rmax1    = aimax[row];
341       nrow1    = ailen[row];
342       low1     = 0;
343       high1    = nrow1;
344       lastcol2 = -1;
345       rp2      = bj + bi[row];
346       ap2      = ba + bi[row];
347       rmax2    = bimax[row];
348       nrow2    = bilen[row];
349       low2     = 0;
350       high2    = nrow2;
351 
352       for (j=0; j<n; j++) {
353         if (v) {if (roworiented) value = v[i*n+j]; else value = v[i+j*m];} else value = 0.0;
354         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
355         if (in[j] >= cstart && in[j] < cend){
356           col = in[j] - cstart;
357           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
358         } else if (in[j] < 0) continue;
359 #if defined(PETSC_USE_DEBUG)
360         else if (in[j] >= mat->cmap->N) {SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);}
361 #endif
362         else {
363           if (mat->was_assembled) {
364             if (!aij->colmap) {
365               ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
366             }
367 #if defined (PETSC_USE_CTABLE)
368             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
369 	    col--;
370 #else
371             col = aij->colmap[in[j]] - 1;
372 #endif
373             if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
374               ierr = DisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
375               col =  in[j];
376               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
377               B = aij->B;
378               b = (Mat_SeqAIJ*)B->data;
379               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
380               rp2      = bj + bi[row];
381               ap2      = ba + bi[row];
382               rmax2    = bimax[row];
383               nrow2    = bilen[row];
384               low2     = 0;
385               high2    = nrow2;
386               bm       = aij->B->rmap->n;
387               ba = b->a;
388             }
389           } else col = in[j];
390           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
391         }
392       }
393     } else {
394       if (!aij->donotstash) {
395         if (roworiented) {
396           if (ignorezeroentries && v[i*n] == 0.0) continue;
397           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n);CHKERRQ(ierr);
398         } else {
399           if (ignorezeroentries && v[i] == 0.0) continue;
400           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m);CHKERRQ(ierr);
401         }
402       }
403     }
404   }
405   PetscFunctionReturn(0);
406 }
407 
408 #undef __FUNCT__
409 #define __FUNCT__ "MatGetValues_MPIAIJ"
410 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
411 {
412   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
413   PetscErrorCode ierr;
414   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
415   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
416 
417   PetscFunctionBegin;
418   for (i=0; i<m; i++) {
419     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
420     if (idxm[i] >= mat->rmap->N) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",idxm[i],mat->rmap->N-1);
421     if (idxm[i] >= rstart && idxm[i] < rend) {
422       row = idxm[i] - rstart;
423       for (j=0; j<n; j++) {
424         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
425         if (idxn[j] >= mat->cmap->N) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",idxn[j],mat->cmap->N-1);
426         if (idxn[j] >= cstart && idxn[j] < cend){
427           col = idxn[j] - cstart;
428           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
429         } else {
430           if (!aij->colmap) {
431             ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
432           }
433 #if defined (PETSC_USE_CTABLE)
434           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
435           col --;
436 #else
437           col = aij->colmap[idxn[j]] - 1;
438 #endif
439           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
440           else {
441             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
442           }
443         }
444       }
445     } else {
446       SETERRQ(PETSC_ERR_SUP,"Only local values currently supported");
447     }
448   }
449   PetscFunctionReturn(0);
450 }
451 
452 #undef __FUNCT__
453 #define __FUNCT__ "MatAssemblyBegin_MPIAIJ"
454 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
455 {
456   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
457   PetscErrorCode ierr;
458   PetscInt       nstash,reallocs;
459   InsertMode     addv;
460 
461   PetscFunctionBegin;
462   if (aij->donotstash) {
463     PetscFunctionReturn(0);
464   }
465 
466   /* make sure all processors are either in INSERTMODE or ADDMODE */
467   ierr = MPI_Allreduce(&mat->insertmode,&addv,1,MPI_INT,MPI_BOR,((PetscObject)mat)->comm);CHKERRQ(ierr);
468   if (addv == (ADD_VALUES|INSERT_VALUES)) {
469     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
470   }
471   mat->insertmode = addv; /* in case this processor had no cache */
472 
473   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
474   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
475   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
476   PetscFunctionReturn(0);
477 }
478 
479 #undef __FUNCT__
480 #define __FUNCT__ "MatAssemblyEnd_MPIAIJ"
481 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
482 {
483   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
484   Mat_SeqAIJ     *a=(Mat_SeqAIJ *)aij->A->data;
485   PetscErrorCode ierr;
486   PetscMPIInt    n;
487   PetscInt       i,j,rstart,ncols,flg;
488   PetscInt       *row,*col;
489   PetscTruth     other_disassembled;
490   PetscScalar    *val;
491   InsertMode     addv = mat->insertmode;
492 
493   /* do not use 'b = (Mat_SeqAIJ *)aij->B->data' as B can be reset in disassembly */
494   PetscFunctionBegin;
495   if (!aij->donotstash) {
496     while (1) {
497       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
498       if (!flg) break;
499 
500       for (i=0; i<n;) {
501         /* Now identify the consecutive vals belonging to the same row */
502         for (j=i,rstart=row[j]; j<n; j++) { if (row[j] != rstart) break; }
503         if (j < n) ncols = j-i;
504         else       ncols = n-i;
505         /* Now assemble all these values with a single function call */
506         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,addv);CHKERRQ(ierr);
507         i = j;
508       }
509     }
510     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
511   }
512   a->compressedrow.use     = PETSC_FALSE;
513   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
514   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
515 
516   /* determine if any processor has disassembled, if so we must
517      also disassemble ourselfs, in order that we may reassemble. */
518   /*
519      if nonzero structure of submatrix B cannot change then we know that
520      no processor disassembled thus we can skip this stuff
521   */
522   if (!((Mat_SeqAIJ*)aij->B->data)->nonew)  {
523     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPI_INT,MPI_PROD,((PetscObject)mat)->comm);CHKERRQ(ierr);
524     if (mat->was_assembled && !other_disassembled) {
525       ierr = DisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
526     }
527   }
528   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
529     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
530   }
531   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
532   ((Mat_SeqAIJ *)aij->B->data)->compressedrow.use = PETSC_TRUE; /* b->compressedrow.use */
533   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
534   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
535 
536   ierr = PetscFree(aij->rowvalues);CHKERRQ(ierr);
537   aij->rowvalues = 0;
538 
539   /* used by MatAXPY() */
540   a->xtoy = 0; ((Mat_SeqAIJ *)aij->B->data)->xtoy = 0;  /* b->xtoy = 0 */
541   a->XtoY = 0; ((Mat_SeqAIJ *)aij->B->data)->XtoY = 0;  /* b->XtoY = 0 */
542 
543   PetscFunctionReturn(0);
544 }
545 
546 #undef __FUNCT__
547 #define __FUNCT__ "MatZeroEntries_MPIAIJ"
548 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
549 {
550   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
551   PetscErrorCode ierr;
552 
553   PetscFunctionBegin;
554   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
555   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
556   PetscFunctionReturn(0);
557 }
558 
559 #undef __FUNCT__
560 #define __FUNCT__ "MatZeroRows_MPIAIJ"
561 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag)
562 {
563   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
564   PetscErrorCode ierr;
565   PetscMPIInt    size = l->size,imdex,n,rank = l->rank,tag = ((PetscObject)A)->tag,lastidx = -1;
566   PetscInt       i,*owners = A->rmap->range;
567   PetscInt       *nprocs,j,idx,nsends,row;
568   PetscInt       nmax,*svalues,*starts,*owner,nrecvs;
569   PetscInt       *rvalues,count,base,slen,*source;
570   PetscInt       *lens,*lrows,*values,rstart=A->rmap->rstart;
571   MPI_Comm       comm = ((PetscObject)A)->comm;
572   MPI_Request    *send_waits,*recv_waits;
573   MPI_Status     recv_status,*send_status;
574 #if defined(PETSC_DEBUG)
575   PetscTruth     found = PETSC_FALSE;
576 #endif
577 
578   PetscFunctionBegin;
579   /*  first count number of contributors to each processor */
580   ierr = PetscMalloc(2*size*sizeof(PetscInt),&nprocs);CHKERRQ(ierr);
581   ierr = PetscMemzero(nprocs,2*size*sizeof(PetscInt));CHKERRQ(ierr);
582   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&owner);CHKERRQ(ierr); /* see note*/
583   j = 0;
584   for (i=0; i<N; i++) {
585     if (lastidx > (idx = rows[i])) j = 0;
586     lastidx = idx;
587     for (; j<size; j++) {
588       if (idx >= owners[j] && idx < owners[j+1]) {
589         nprocs[2*j]++;
590         nprocs[2*j+1] = 1;
591         owner[i] = j;
592 #if defined(PETSC_DEBUG)
593         found = PETSC_TRUE;
594 #endif
595         break;
596       }
597     }
598 #if defined(PETSC_DEBUG)
599     if (!found) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Index out of range");
600     found = PETSC_FALSE;
601 #endif
602   }
603   nsends = 0;  for (i=0; i<size; i++) { nsends += nprocs[2*i+1];}
604 
605   /* inform other processors of number of messages and max length*/
606   ierr = PetscMaxSum(comm,nprocs,&nmax,&nrecvs);CHKERRQ(ierr);
607 
608   /* post receives:   */
609   ierr = PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(PetscInt),&rvalues);CHKERRQ(ierr);
610   ierr = PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);CHKERRQ(ierr);
611   for (i=0; i<nrecvs; i++) {
612     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPIU_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
613   }
614 
615   /* do sends:
616       1) starts[i] gives the starting index in svalues for stuff going to
617          the ith processor
618   */
619   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&svalues);CHKERRQ(ierr);
620   ierr = PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);CHKERRQ(ierr);
621   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&starts);CHKERRQ(ierr);
622   starts[0] = 0;
623   for (i=1; i<size; i++) { starts[i] = starts[i-1] + nprocs[2*i-2];}
624   for (i=0; i<N; i++) {
625     svalues[starts[owner[i]]++] = rows[i];
626   }
627 
628   starts[0] = 0;
629   for (i=1; i<size+1; i++) { starts[i] = starts[i-1] + nprocs[2*i-2];}
630   count = 0;
631   for (i=0; i<size; i++) {
632     if (nprocs[2*i+1]) {
633       ierr = MPI_Isend(svalues+starts[i],nprocs[2*i],MPIU_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
634     }
635   }
636   ierr = PetscFree(starts);CHKERRQ(ierr);
637 
638   base = owners[rank];
639 
640   /*  wait on receives */
641   ierr   = PetscMalloc(2*(nrecvs+1)*sizeof(PetscInt),&lens);CHKERRQ(ierr);
642   source = lens + nrecvs;
643   count  = nrecvs; slen = 0;
644   while (count) {
645     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
646     /* unpack receives into our local space */
647     ierr = MPI_Get_count(&recv_status,MPIU_INT,&n);CHKERRQ(ierr);
648     source[imdex]  = recv_status.MPI_SOURCE;
649     lens[imdex]    = n;
650     slen          += n;
651     count--;
652   }
653   ierr = PetscFree(recv_waits);CHKERRQ(ierr);
654 
655   /* move the data into the send scatter */
656   ierr = PetscMalloc((slen+1)*sizeof(PetscInt),&lrows);CHKERRQ(ierr);
657   count = 0;
658   for (i=0; i<nrecvs; i++) {
659     values = rvalues + i*nmax;
660     for (j=0; j<lens[i]; j++) {
661       lrows[count++] = values[j] - base;
662     }
663   }
664   ierr = PetscFree(rvalues);CHKERRQ(ierr);
665   ierr = PetscFree(lens);CHKERRQ(ierr);
666   ierr = PetscFree(owner);CHKERRQ(ierr);
667   ierr = PetscFree(nprocs);CHKERRQ(ierr);
668 
669   /* actually zap the local rows */
670   /*
671         Zero the required rows. If the "diagonal block" of the matrix
672      is square and the user wishes to set the diagonal we use separate
673      code so that MatSetValues() is not called for each diagonal allocating
674      new memory, thus calling lots of mallocs and slowing things down.
675 
676        Contributed by: Matthew Knepley
677   */
678   /* must zero l->B before l->A because the (diag) case below may put values into l->B*/
679   ierr = MatZeroRows(l->B,slen,lrows,0.0);CHKERRQ(ierr);
680   if ((diag != 0.0) && (l->A->rmap->N == l->A->cmap->N)) {
681     ierr      = MatZeroRows(l->A,slen,lrows,diag);CHKERRQ(ierr);
682   } else if (diag != 0.0) {
683     ierr = MatZeroRows(l->A,slen,lrows,0.0);CHKERRQ(ierr);
684     if (((Mat_SeqAIJ*)l->A->data)->nonew) {
685       SETERRQ(PETSC_ERR_SUP,"MatZeroRows() on rectangular matrices cannot be used with the Mat options\n\
686 MAT_NEW_NONZERO_LOCATIONS,MAT_NEW_NONZERO_LOCATION_ERR,MAT_NEW_NONZERO_ALLOCATION_ERR");
687     }
688     for (i = 0; i < slen; i++) {
689       row  = lrows[i] + rstart;
690       ierr = MatSetValues(A,1,&row,1,&row,&diag,INSERT_VALUES);CHKERRQ(ierr);
691     }
692     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
693     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
694   } else {
695     ierr = MatZeroRows(l->A,slen,lrows,0.0);CHKERRQ(ierr);
696   }
697   ierr = PetscFree(lrows);CHKERRQ(ierr);
698 
699   /* wait on sends */
700   if (nsends) {
701     ierr = PetscMalloc(nsends*sizeof(MPI_Status),&send_status);CHKERRQ(ierr);
702     ierr = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
703     ierr = PetscFree(send_status);CHKERRQ(ierr);
704   }
705   ierr = PetscFree(send_waits);CHKERRQ(ierr);
706   ierr = PetscFree(svalues);CHKERRQ(ierr);
707 
708   PetscFunctionReturn(0);
709 }
710 
711 #undef __FUNCT__
712 #define __FUNCT__ "MatMult_MPIAIJ"
713 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
714 {
715   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
716   PetscErrorCode ierr;
717   PetscInt       nt;
718 
719   PetscFunctionBegin;
720   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
721   if (nt != A->cmap->n) {
722     SETERRQ2(PETSC_ERR_ARG_SIZ,"Incompatible partition of A (%D) and xx (%D)",A->cmap->n,nt);
723   }
724   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
725   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
726   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
727   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
728   PetscFunctionReturn(0);
729 }
730 
731 #undef __FUNCT__
732 #define __FUNCT__ "MatMultAdd_MPIAIJ"
733 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
734 {
735   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
736   PetscErrorCode ierr;
737 
738   PetscFunctionBegin;
739   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
740   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
741   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
742   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
743   PetscFunctionReturn(0);
744 }
745 
746 #undef __FUNCT__
747 #define __FUNCT__ "MatMultTranspose_MPIAIJ"
748 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
749 {
750   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
751   PetscErrorCode ierr;
752   PetscTruth     merged;
753 
754   PetscFunctionBegin;
755   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
756   /* do nondiagonal part */
757   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
758   if (!merged) {
759     /* send it on its way */
760     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
761     /* do local part */
762     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
763     /* receive remote parts: note this assumes the values are not actually */
764     /* added in yy until the next line, */
765     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
766   } else {
767     /* do local part */
768     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
769     /* send it on its way */
770     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
771     /* values actually were received in the Begin() but we need to call this nop */
772     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
773   }
774   PetscFunctionReturn(0);
775 }
776 
777 EXTERN_C_BEGIN
778 #undef __FUNCT__
779 #define __FUNCT__ "MatIsTranspose_MPIAIJ"
780 PetscErrorCode PETSCMAT_DLLEXPORT MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscTruth *f)
781 {
782   MPI_Comm       comm;
783   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ *) Amat->data, *Bij;
784   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
785   IS             Me,Notme;
786   PetscErrorCode ierr;
787   PetscInt       M,N,first,last,*notme,i;
788   PetscMPIInt    size;
789 
790   PetscFunctionBegin;
791 
792   /* Easy test: symmetric diagonal block */
793   Bij = (Mat_MPIAIJ *) Bmat->data; Bdia = Bij->A;
794   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
795   if (!*f) PetscFunctionReturn(0);
796   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
797   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
798   if (size == 1) PetscFunctionReturn(0);
799 
800   /* Hard test: off-diagonal block. This takes a MatGetSubMatrix. */
801   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
802   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
803   ierr = PetscMalloc((N-last+first)*sizeof(PetscInt),&notme);CHKERRQ(ierr);
804   for (i=0; i<first; i++) notme[i] = i;
805   for (i=last; i<M; i++) notme[i-last+first] = i;
806   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,&Notme);CHKERRQ(ierr);
807   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
808   ierr = MatGetSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
809   Aoff = Aoffs[0];
810   ierr = MatGetSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
811   Boff = Boffs[0];
812   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
813   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
814   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
815   ierr = ISDestroy(Me);CHKERRQ(ierr);
816   ierr = ISDestroy(Notme);CHKERRQ(ierr);
817 
818   PetscFunctionReturn(0);
819 }
820 EXTERN_C_END
821 
822 #undef __FUNCT__
823 #define __FUNCT__ "MatMultTransposeAdd_MPIAIJ"
824 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
825 {
826   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
827   PetscErrorCode ierr;
828 
829   PetscFunctionBegin;
830   /* do nondiagonal part */
831   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
832   /* send it on its way */
833   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
834   /* do local part */
835   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
836   /* receive remote parts */
837   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
838   PetscFunctionReturn(0);
839 }
840 
841 /*
842   This only works correctly for square matrices where the subblock A->A is the
843    diagonal block
844 */
845 #undef __FUNCT__
846 #define __FUNCT__ "MatGetDiagonal_MPIAIJ"
847 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
848 {
849   PetscErrorCode ierr;
850   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
851 
852   PetscFunctionBegin;
853   if (A->rmap->N != A->cmap->N) SETERRQ(PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
854   if (A->rmap->rstart != A->cmap->rstart || A->rmap->rend != A->cmap->rend) {
855     SETERRQ(PETSC_ERR_ARG_SIZ,"row partition must equal col partition");
856   }
857   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
858   PetscFunctionReturn(0);
859 }
860 
861 #undef __FUNCT__
862 #define __FUNCT__ "MatScale_MPIAIJ"
863 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
864 {
865   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
866   PetscErrorCode ierr;
867 
868   PetscFunctionBegin;
869   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
870   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
871   PetscFunctionReturn(0);
872 }
873 
874 #undef __FUNCT__
875 #define __FUNCT__ "MatDestroy_MPIAIJ"
876 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
877 {
878   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
879   PetscErrorCode ierr;
880 
881   PetscFunctionBegin;
882 #if defined(PETSC_USE_LOG)
883   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
884 #endif
885   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
886   ierr = MatDestroy(aij->A);CHKERRQ(ierr);
887   ierr = MatDestroy(aij->B);CHKERRQ(ierr);
888 #if defined (PETSC_USE_CTABLE)
889   if (aij->colmap) {ierr = PetscTableDestroy(aij->colmap);CHKERRQ(ierr);}
890 #else
891   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
892 #endif
893   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
894   if (aij->lvec)   {ierr = VecDestroy(aij->lvec);CHKERRQ(ierr);}
895   if (aij->Mvctx)  {ierr = VecScatterDestroy(aij->Mvctx);CHKERRQ(ierr);}
896   ierr = PetscFree(aij->rowvalues);CHKERRQ(ierr);
897   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
898   ierr = PetscFree(aij);CHKERRQ(ierr);
899 
900   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
901   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C","",PETSC_NULL);CHKERRQ(ierr);
902   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C","",PETSC_NULL);CHKERRQ(ierr);
903   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatGetDiagonalBlock_C","",PETSC_NULL);CHKERRQ(ierr);
904   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C","",PETSC_NULL);CHKERRQ(ierr);
905   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C","",PETSC_NULL);CHKERRQ(ierr);
906   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C","",PETSC_NULL);CHKERRQ(ierr);
907   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C","",PETSC_NULL);CHKERRQ(ierr);
908   PetscFunctionReturn(0);
909 }
910 
911 #undef __FUNCT__
912 #define __FUNCT__ "MatView_MPIAIJ_Binary"
913 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
914 {
915   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
916   Mat_SeqAIJ*       A = (Mat_SeqAIJ*)aij->A->data;
917   Mat_SeqAIJ*       B = (Mat_SeqAIJ*)aij->B->data;
918   PetscErrorCode    ierr;
919   PetscMPIInt       rank,size,tag = ((PetscObject)viewer)->tag;
920   int               fd;
921   PetscInt          nz,header[4],*row_lengths,*range=0,rlen,i;
922   PetscInt          nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz;
923   PetscScalar       *column_values;
924 
925   PetscFunctionBegin;
926   ierr = MPI_Comm_rank(((PetscObject)mat)->comm,&rank);CHKERRQ(ierr);
927   ierr = MPI_Comm_size(((PetscObject)mat)->comm,&size);CHKERRQ(ierr);
928   nz   = A->nz + B->nz;
929   if (!rank) {
930     header[0] = MAT_FILE_COOKIE;
931     header[1] = mat->rmap->N;
932     header[2] = mat->cmap->N;
933     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,((PetscObject)mat)->comm);CHKERRQ(ierr);
934     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
935     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
936     /* get largest number of rows any processor has */
937     rlen = mat->rmap->n;
938     range = mat->rmap->range;
939     for (i=1; i<size; i++) {
940       rlen = PetscMax(rlen,range[i+1] - range[i]);
941     }
942   } else {
943     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,((PetscObject)mat)->comm);CHKERRQ(ierr);
944     rlen = mat->rmap->n;
945   }
946 
947   /* load up the local row counts */
948   ierr = PetscMalloc((rlen+1)*sizeof(PetscInt),&row_lengths);CHKERRQ(ierr);
949   for (i=0; i<mat->rmap->n; i++) {
950     row_lengths[i] = A->i[i+1] - A->i[i] + B->i[i+1] - B->i[i];
951   }
952 
953   /* store the row lengths to the file */
954   if (!rank) {
955     MPI_Status status;
956     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
957     for (i=1; i<size; i++) {
958       rlen = range[i+1] - range[i];
959       ierr = MPI_Recv(row_lengths,rlen,MPIU_INT,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
960       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
961     }
962   } else {
963     ierr = MPI_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
964   }
965   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
966 
967   /* load up the local column indices */
968   nzmax = nz; /* )th processor needs space a largest processor needs */
969   ierr = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,((PetscObject)mat)->comm);CHKERRQ(ierr);
970   ierr = PetscMalloc((nzmax+1)*sizeof(PetscInt),&column_indices);CHKERRQ(ierr);
971   cnt  = 0;
972   for (i=0; i<mat->rmap->n; i++) {
973     for (j=B->i[i]; j<B->i[i+1]; j++) {
974       if ( (col = garray[B->j[j]]) > cstart) break;
975       column_indices[cnt++] = col;
976     }
977     for (k=A->i[i]; k<A->i[i+1]; k++) {
978       column_indices[cnt++] = A->j[k] + cstart;
979     }
980     for (; j<B->i[i+1]; j++) {
981       column_indices[cnt++] = garray[B->j[j]];
982     }
983   }
984   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_ERR_LIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
985 
986   /* store the column indices to the file */
987   if (!rank) {
988     MPI_Status status;
989     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
990     for (i=1; i<size; i++) {
991       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
992       if (rnz > nzmax) SETERRQ2(PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
993       ierr = MPI_Recv(column_indices,rnz,MPIU_INT,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
994       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
995     }
996   } else {
997     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
998     ierr = MPI_Send(column_indices,nz,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
999   }
1000   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1001 
1002   /* load up the local column values */
1003   ierr = PetscMalloc((nzmax+1)*sizeof(PetscScalar),&column_values);CHKERRQ(ierr);
1004   cnt  = 0;
1005   for (i=0; i<mat->rmap->n; i++) {
1006     for (j=B->i[i]; j<B->i[i+1]; j++) {
1007       if ( garray[B->j[j]] > cstart) break;
1008       column_values[cnt++] = B->a[j];
1009     }
1010     for (k=A->i[i]; k<A->i[i+1]; k++) {
1011       column_values[cnt++] = A->a[k];
1012     }
1013     for (; j<B->i[i+1]; j++) {
1014       column_values[cnt++] = B->a[j];
1015     }
1016   }
1017   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_ERR_PLIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1018 
1019   /* store the column values to the file */
1020   if (!rank) {
1021     MPI_Status status;
1022     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1023     for (i=1; i<size; i++) {
1024       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
1025       if (rnz > nzmax) SETERRQ2(PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1026       ierr = MPI_Recv(column_values,rnz,MPIU_SCALAR,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
1027       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1028     }
1029   } else {
1030     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1031     ierr = MPI_Send(column_values,nz,MPIU_SCALAR,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1032   }
1033   ierr = PetscFree(column_values);CHKERRQ(ierr);
1034   PetscFunctionReturn(0);
1035 }
1036 
1037 #undef __FUNCT__
1038 #define __FUNCT__ "MatView_MPIAIJ_ASCIIorDraworSocket"
1039 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1040 {
1041   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1042   PetscErrorCode    ierr;
1043   PetscMPIInt       rank = aij->rank,size = aij->size;
1044   PetscTruth        isdraw,iascii,isbinary;
1045   PetscViewer       sviewer;
1046   PetscViewerFormat format;
1047 
1048   PetscFunctionBegin;
1049   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_DRAW,&isdraw);CHKERRQ(ierr);
1050   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
1051   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_BINARY,&isbinary);CHKERRQ(ierr);
1052   if (iascii) {
1053     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1054     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1055       MatInfo    info;
1056       PetscTruth inodes;
1057 
1058       ierr = MPI_Comm_rank(((PetscObject)mat)->comm,&rank);CHKERRQ(ierr);
1059       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1060       ierr = MatInodeGetInodeSizes(aij->A,PETSC_NULL,(PetscInt **)&inodes,PETSC_NULL);CHKERRQ(ierr);
1061       if (!inodes) {
1062         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1063 					      rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1064       } else {
1065         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1066 		    rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1067       }
1068       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1069       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1070       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1071       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1072       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1073       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1074       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1075       PetscFunctionReturn(0);
1076     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1077       PetscInt   inodecount,inodelimit,*inodes;
1078       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1079       if (inodes) {
1080         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1081       } else {
1082         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1083       }
1084       PetscFunctionReturn(0);
1085     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1086       PetscFunctionReturn(0);
1087     }
1088   } else if (isbinary) {
1089     if (size == 1) {
1090       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1091       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1092     } else {
1093       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1094     }
1095     PetscFunctionReturn(0);
1096   } else if (isdraw) {
1097     PetscDraw  draw;
1098     PetscTruth isnull;
1099     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1100     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1101   }
1102 
1103   if (size == 1) {
1104     ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1105     ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1106   } else {
1107     /* assemble the entire matrix onto first processor. */
1108     Mat         A;
1109     Mat_SeqAIJ  *Aloc;
1110     PetscInt    M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1111     MatScalar   *a;
1112 
1113     if (mat->rmap->N > 1024) {
1114       PetscTruth flg;
1115 
1116       ierr = PetscOptionsHasName(((PetscObject) mat)->prefix, "-mat_ascii_output_large", &flg);CHKERRQ(ierr);
1117       if (!flg) {
1118         SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"ASCII matrix output not allowed for matrices with more than 512 rows, use binary format instead.\nYou can override this restriction using -mat_ascii_output_large.");
1119       }
1120     }
1121 
1122     ierr = MatCreate(((PetscObject)mat)->comm,&A);CHKERRQ(ierr);
1123     if (!rank) {
1124       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1125     } else {
1126       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1127     }
1128     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1129     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1130     ierr = MatMPIAIJSetPreallocation(A,0,PETSC_NULL,0,PETSC_NULL);CHKERRQ(ierr);
1131     ierr = PetscLogObjectParent(mat,A);CHKERRQ(ierr);
1132 
1133     /* copy over the A part */
1134     Aloc = (Mat_SeqAIJ*)aij->A->data;
1135     m = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1136     row = mat->rmap->rstart;
1137     for (i=0; i<ai[m]; i++) {aj[i] += mat->cmap->rstart ;}
1138     for (i=0; i<m; i++) {
1139       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1140       row++; a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1141     }
1142     aj = Aloc->j;
1143     for (i=0; i<ai[m]; i++) {aj[i] -= mat->cmap->rstart;}
1144 
1145     /* copy over the B part */
1146     Aloc = (Mat_SeqAIJ*)aij->B->data;
1147     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1148     row  = mat->rmap->rstart;
1149     ierr = PetscMalloc((ai[m]+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
1150     ct   = cols;
1151     for (i=0; i<ai[m]; i++) {cols[i] = aij->garray[aj[i]];}
1152     for (i=0; i<m; i++) {
1153       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1154       row++; a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1155     }
1156     ierr = PetscFree(ct);CHKERRQ(ierr);
1157     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1158     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1159     /*
1160        Everyone has to call to draw the matrix since the graphics waits are
1161        synchronized across all processors that share the PetscDraw object
1162     */
1163     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
1164     if (!rank) {
1165       ierr = PetscObjectSetName((PetscObject)((Mat_MPIAIJ*)(A->data))->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1166       ierr = MatView(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1167     }
1168     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
1169     ierr = MatDestroy(A);CHKERRQ(ierr);
1170   }
1171   PetscFunctionReturn(0);
1172 }
1173 
1174 #undef __FUNCT__
1175 #define __FUNCT__ "MatView_MPIAIJ"
1176 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1177 {
1178   PetscErrorCode ierr;
1179   PetscTruth     iascii,isdraw,issocket,isbinary;
1180 
1181   PetscFunctionBegin;
1182   ierr  = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
1183   ierr  = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_DRAW,&isdraw);CHKERRQ(ierr);
1184   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_BINARY,&isbinary);CHKERRQ(ierr);
1185   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_SOCKET,&issocket);CHKERRQ(ierr);
1186   if (iascii || isdraw || isbinary || issocket) {
1187     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1188   } else {
1189     SETERRQ1(PETSC_ERR_SUP,"Viewer type %s not supported by MPIAIJ matrices",((PetscObject)viewer)->type_name);
1190   }
1191   PetscFunctionReturn(0);
1192 }
1193 
1194 #undef __FUNCT__
1195 #define __FUNCT__ "MatRelax_MPIAIJ"
1196 PetscErrorCode MatRelax_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1197 {
1198   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1199   PetscErrorCode ierr;
1200   Vec            bb1;
1201 
1202   PetscFunctionBegin;
1203   ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1204 
1205   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP){
1206     if (flag & SOR_ZERO_INITIAL_GUESS) {
1207       ierr = (*mat->A->ops->relax)(mat->A,bb,omega,flag,fshift,lits,lits,xx);CHKERRQ(ierr);
1208       its--;
1209     }
1210 
1211     while (its--) {
1212       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1213       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1214 
1215       /* update rhs: bb1 = bb - B*x */
1216       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1217       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1218 
1219       /* local sweep */
1220       ierr = (*mat->A->ops->relax)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,lits,xx);CHKERRQ(ierr);
1221     }
1222   } else if (flag & SOR_LOCAL_FORWARD_SWEEP){
1223     if (flag & SOR_ZERO_INITIAL_GUESS) {
1224       ierr = (*mat->A->ops->relax)(mat->A,bb,omega,flag,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1225       its--;
1226     }
1227     while (its--) {
1228       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1229       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1230 
1231       /* update rhs: bb1 = bb - B*x */
1232       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1233       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1234 
1235       /* local sweep */
1236       ierr = (*mat->A->ops->relax)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1237     }
1238   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP){
1239     if (flag & SOR_ZERO_INITIAL_GUESS) {
1240       ierr = (*mat->A->ops->relax)(mat->A,bb,omega,flag,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1241       its--;
1242     }
1243     while (its--) {
1244       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1245       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1246 
1247       /* update rhs: bb1 = bb - B*x */
1248       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1249       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1250 
1251       /* local sweep */
1252       ierr = (*mat->A->ops->relax)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1253     }
1254   } else {
1255     SETERRQ(PETSC_ERR_SUP,"Parallel SOR not supported");
1256   }
1257 
1258   ierr = VecDestroy(bb1);CHKERRQ(ierr);
1259   PetscFunctionReturn(0);
1260 }
1261 
1262 #undef __FUNCT__
1263 #define __FUNCT__ "MatPermute_MPIAIJ"
1264 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1265 {
1266   MPI_Comm       comm,pcomm;
1267   PetscInt       first,local_size,nrows;
1268   const PetscInt *rows;
1269   PetscMPIInt    size;
1270   IS             crowp,growp,irowp,lrowp,lcolp,icolp;
1271   PetscErrorCode ierr;
1272 
1273   PetscFunctionBegin;
1274   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
1275   /* make a collective version of 'rowp' */
1276   ierr = PetscObjectGetComm((PetscObject)rowp,&pcomm);CHKERRQ(ierr);
1277   if (pcomm==comm) {
1278     crowp = rowp;
1279   } else {
1280     ierr = ISGetSize(rowp,&nrows);CHKERRQ(ierr);
1281     ierr = ISGetIndices(rowp,&rows);CHKERRQ(ierr);
1282     ierr = ISCreateGeneral(comm,nrows,rows,&crowp);CHKERRQ(ierr);
1283     ierr = ISRestoreIndices(rowp,&rows);CHKERRQ(ierr);
1284   }
1285   /* collect the global row permutation and invert it */
1286   ierr = ISAllGather(crowp,&growp);CHKERRQ(ierr);
1287   ierr = ISSetPermutation(growp);CHKERRQ(ierr);
1288   if (pcomm!=comm) {
1289     ierr = ISDestroy(crowp);CHKERRQ(ierr);
1290   }
1291   ierr = ISInvertPermutation(growp,PETSC_DECIDE,&irowp);CHKERRQ(ierr);
1292   /* get the local target indices */
1293   ierr = MatGetOwnershipRange(A,&first,PETSC_NULL);CHKERRQ(ierr);
1294   ierr = MatGetLocalSize(A,&local_size,PETSC_NULL);CHKERRQ(ierr);
1295   ierr = ISGetIndices(irowp,&rows);CHKERRQ(ierr);
1296   ierr = ISCreateGeneral(MPI_COMM_SELF,local_size,rows+first,&lrowp);CHKERRQ(ierr);
1297   ierr = ISRestoreIndices(irowp,&rows);CHKERRQ(ierr);
1298   ierr = ISDestroy(irowp);CHKERRQ(ierr);
1299   /* the column permutation is so much easier;
1300      make a local version of 'colp' and invert it */
1301   ierr = PetscObjectGetComm((PetscObject)colp,&pcomm);CHKERRQ(ierr);
1302   ierr = MPI_Comm_size(pcomm,&size);CHKERRQ(ierr);
1303   if (size==1) {
1304     lcolp = colp;
1305   } else {
1306     ierr = ISGetSize(colp,&nrows);CHKERRQ(ierr);
1307     ierr = ISGetIndices(colp,&rows);CHKERRQ(ierr);
1308     ierr = ISCreateGeneral(MPI_COMM_SELF,nrows,rows,&lcolp);CHKERRQ(ierr);
1309   }
1310   ierr = ISSetPermutation(lcolp);CHKERRQ(ierr);
1311   ierr = ISInvertPermutation(lcolp,PETSC_DECIDE,&icolp);CHKERRQ(ierr);
1312   ierr = ISSetPermutation(lcolp);CHKERRQ(ierr);
1313   if (size>1) {
1314     ierr = ISRestoreIndices(colp,&rows);CHKERRQ(ierr);
1315     ierr = ISDestroy(lcolp);CHKERRQ(ierr);
1316   }
1317   /* now we just get the submatrix */
1318   ierr = MatGetSubMatrix(A,lrowp,icolp,local_size,MAT_INITIAL_MATRIX,B);CHKERRQ(ierr);
1319   /* clean up */
1320   ierr = ISDestroy(lrowp);CHKERRQ(ierr);
1321   ierr = ISDestroy(icolp);CHKERRQ(ierr);
1322   PetscFunctionReturn(0);
1323 }
1324 
1325 #undef __FUNCT__
1326 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1327 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1328 {
1329   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1330   Mat            A = mat->A,B = mat->B;
1331   PetscErrorCode ierr;
1332   PetscReal      isend[5],irecv[5];
1333 
1334   PetscFunctionBegin;
1335   info->block_size     = 1.0;
1336   ierr = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1337   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1338   isend[3] = info->memory;  isend[4] = info->mallocs;
1339   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1340   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1341   isend[3] += info->memory;  isend[4] += info->mallocs;
1342   if (flag == MAT_LOCAL) {
1343     info->nz_used      = isend[0];
1344     info->nz_allocated = isend[1];
1345     info->nz_unneeded  = isend[2];
1346     info->memory       = isend[3];
1347     info->mallocs      = isend[4];
1348   } else if (flag == MAT_GLOBAL_MAX) {
1349     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPI_MAX,((PetscObject)matin)->comm);CHKERRQ(ierr);
1350     info->nz_used      = irecv[0];
1351     info->nz_allocated = irecv[1];
1352     info->nz_unneeded  = irecv[2];
1353     info->memory       = irecv[3];
1354     info->mallocs      = irecv[4];
1355   } else if (flag == MAT_GLOBAL_SUM) {
1356     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPI_SUM,((PetscObject)matin)->comm);CHKERRQ(ierr);
1357     info->nz_used      = irecv[0];
1358     info->nz_allocated = irecv[1];
1359     info->nz_unneeded  = irecv[2];
1360     info->memory       = irecv[3];
1361     info->mallocs      = irecv[4];
1362   }
1363   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1364   info->fill_ratio_needed = 0;
1365   info->factor_mallocs    = 0;
1366 
1367   PetscFunctionReturn(0);
1368 }
1369 
1370 #undef __FUNCT__
1371 #define __FUNCT__ "MatSetOption_MPIAIJ"
1372 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscTruth flg)
1373 {
1374   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1375   PetscErrorCode ierr;
1376 
1377   PetscFunctionBegin;
1378   switch (op) {
1379   case MAT_NEW_NONZERO_LOCATIONS:
1380   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1381   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1382   case MAT_KEEP_ZEROED_ROWS:
1383   case MAT_NEW_NONZERO_LOCATION_ERR:
1384   case MAT_USE_INODES:
1385   case MAT_IGNORE_ZERO_ENTRIES:
1386     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1387     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1388     break;
1389   case MAT_ROW_ORIENTED:
1390     a->roworiented = flg;
1391     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1392     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1393     break;
1394   case MAT_NEW_DIAGONALS:
1395     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1396     break;
1397   case MAT_IGNORE_OFF_PROC_ENTRIES:
1398     a->donotstash = PETSC_TRUE;
1399     break;
1400   case MAT_SYMMETRIC:
1401     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1402     break;
1403   case MAT_STRUCTURALLY_SYMMETRIC:
1404   case MAT_HERMITIAN:
1405   case MAT_SYMMETRY_ETERNAL:
1406     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1407     break;
1408   default:
1409     SETERRQ1(PETSC_ERR_SUP,"unknown option %d",op);
1410   }
1411   PetscFunctionReturn(0);
1412 }
1413 
1414 #undef __FUNCT__
1415 #define __FUNCT__ "MatGetRow_MPIAIJ"
1416 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1417 {
1418   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1419   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1420   PetscErrorCode ierr;
1421   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1422   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1423   PetscInt       *cmap,*idx_p;
1424 
1425   PetscFunctionBegin;
1426   if (mat->getrowactive) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Already active");
1427   mat->getrowactive = PETSC_TRUE;
1428 
1429   if (!mat->rowvalues && (idx || v)) {
1430     /*
1431         allocate enough space to hold information from the longest row.
1432     */
1433     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1434     PetscInt     max = 1,tmp;
1435     for (i=0; i<matin->rmap->n; i++) {
1436       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1437       if (max < tmp) { max = tmp; }
1438     }
1439     ierr = PetscMalloc(max*(sizeof(PetscInt)+sizeof(PetscScalar)),&mat->rowvalues);CHKERRQ(ierr);
1440     mat->rowindices = (PetscInt*)(mat->rowvalues + max);
1441   }
1442 
1443   if (row < rstart || row >= rend) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Only local rows")
1444   lrow = row - rstart;
1445 
1446   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1447   if (!v)   {pvA = 0; pvB = 0;}
1448   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1449   ierr = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1450   ierr = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1451   nztot = nzA + nzB;
1452 
1453   cmap  = mat->garray;
1454   if (v  || idx) {
1455     if (nztot) {
1456       /* Sort by increasing column numbers, assuming A and B already sorted */
1457       PetscInt imark = -1;
1458       if (v) {
1459         *v = v_p = mat->rowvalues;
1460         for (i=0; i<nzB; i++) {
1461           if (cmap[cworkB[i]] < cstart)   v_p[i] = vworkB[i];
1462           else break;
1463         }
1464         imark = i;
1465         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1466         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1467       }
1468       if (idx) {
1469         *idx = idx_p = mat->rowindices;
1470         if (imark > -1) {
1471           for (i=0; i<imark; i++) {
1472             idx_p[i] = cmap[cworkB[i]];
1473           }
1474         } else {
1475           for (i=0; i<nzB; i++) {
1476             if (cmap[cworkB[i]] < cstart)   idx_p[i] = cmap[cworkB[i]];
1477             else break;
1478           }
1479           imark = i;
1480         }
1481         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1482         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1483       }
1484     } else {
1485       if (idx) *idx = 0;
1486       if (v)   *v   = 0;
1487     }
1488   }
1489   *nz = nztot;
1490   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1491   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1492   PetscFunctionReturn(0);
1493 }
1494 
1495 #undef __FUNCT__
1496 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1497 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1498 {
1499   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1500 
1501   PetscFunctionBegin;
1502   if (!aij->getrowactive) {
1503     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1504   }
1505   aij->getrowactive = PETSC_FALSE;
1506   PetscFunctionReturn(0);
1507 }
1508 
1509 #undef __FUNCT__
1510 #define __FUNCT__ "MatNorm_MPIAIJ"
1511 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1512 {
1513   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1514   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1515   PetscErrorCode ierr;
1516   PetscInt       i,j,cstart = mat->cmap->rstart;
1517   PetscReal      sum = 0.0;
1518   MatScalar      *v;
1519 
1520   PetscFunctionBegin;
1521   if (aij->size == 1) {
1522     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1523   } else {
1524     if (type == NORM_FROBENIUS) {
1525       v = amat->a;
1526       for (i=0; i<amat->nz; i++) {
1527 #if defined(PETSC_USE_COMPLEX)
1528         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1529 #else
1530         sum += (*v)*(*v); v++;
1531 #endif
1532       }
1533       v = bmat->a;
1534       for (i=0; i<bmat->nz; i++) {
1535 #if defined(PETSC_USE_COMPLEX)
1536         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1537 #else
1538         sum += (*v)*(*v); v++;
1539 #endif
1540       }
1541       ierr = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPI_SUM,((PetscObject)mat)->comm);CHKERRQ(ierr);
1542       *norm = sqrt(*norm);
1543     } else if (type == NORM_1) { /* max column norm */
1544       PetscReal *tmp,*tmp2;
1545       PetscInt  *jj,*garray = aij->garray;
1546       ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp);CHKERRQ(ierr);
1547       ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp2);CHKERRQ(ierr);
1548       ierr = PetscMemzero(tmp,mat->cmap->N*sizeof(PetscReal));CHKERRQ(ierr);
1549       *norm = 0.0;
1550       v = amat->a; jj = amat->j;
1551       for (j=0; j<amat->nz; j++) {
1552         tmp[cstart + *jj++ ] += PetscAbsScalar(*v);  v++;
1553       }
1554       v = bmat->a; jj = bmat->j;
1555       for (j=0; j<bmat->nz; j++) {
1556         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1557       }
1558       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPI_SUM,((PetscObject)mat)->comm);CHKERRQ(ierr);
1559       for (j=0; j<mat->cmap->N; j++) {
1560         if (tmp2[j] > *norm) *norm = tmp2[j];
1561       }
1562       ierr = PetscFree(tmp);CHKERRQ(ierr);
1563       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1564     } else if (type == NORM_INFINITY) { /* max row norm */
1565       PetscReal ntemp = 0.0;
1566       for (j=0; j<aij->A->rmap->n; j++) {
1567         v = amat->a + amat->i[j];
1568         sum = 0.0;
1569         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1570           sum += PetscAbsScalar(*v); v++;
1571         }
1572         v = bmat->a + bmat->i[j];
1573         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1574           sum += PetscAbsScalar(*v); v++;
1575         }
1576         if (sum > ntemp) ntemp = sum;
1577       }
1578       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPI_MAX,((PetscObject)mat)->comm);CHKERRQ(ierr);
1579     } else {
1580       SETERRQ(PETSC_ERR_SUP,"No support for two norm");
1581     }
1582   }
1583   PetscFunctionReturn(0);
1584 }
1585 
1586 #undef __FUNCT__
1587 #define __FUNCT__ "MatTranspose_MPIAIJ"
1588 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
1589 {
1590   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1591   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
1592   PetscErrorCode ierr;
1593   PetscInt       M = A->rmap->N,N = A->cmap->N,ma,na,mb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i,*d_nnz;
1594   PetscInt       cstart=A->cmap->rstart,ncol;
1595   Mat            B;
1596   MatScalar      *array;
1597 
1598   PetscFunctionBegin;
1599   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
1600 
1601   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n;
1602   ai = Aloc->i; aj = Aloc->j;
1603   bi = Bloc->i; bj = Bloc->j;
1604   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1605     /* compute d_nnz for preallocation; o_nnz is approximated by d_nnz to avoid communication */
1606     ierr = PetscMalloc((1+na)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr);
1607     ierr = PetscMemzero(d_nnz,(1+na)*sizeof(PetscInt));CHKERRQ(ierr);
1608     for (i=0; i<ai[ma]; i++){
1609       d_nnz[aj[i]] ++;
1610       aj[i] += cstart; /* global col index to be used by MatSetValues() */
1611     }
1612 
1613     ierr = MatCreate(((PetscObject)A)->comm,&B);CHKERRQ(ierr);
1614     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
1615     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
1616     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,d_nnz);CHKERRQ(ierr);
1617     ierr = PetscFree(d_nnz);CHKERRQ(ierr);
1618   } else {
1619     B = *matout;
1620   }
1621 
1622   /* copy over the A part */
1623   array = Aloc->a;
1624   row = A->rmap->rstart;
1625   for (i=0; i<ma; i++) {
1626     ncol = ai[i+1]-ai[i];
1627     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1628     row++; array += ncol; aj += ncol;
1629   }
1630   aj = Aloc->j;
1631   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
1632 
1633   /* copy over the B part */
1634   ierr = PetscMalloc(bi[mb]*sizeof(PetscInt),&cols);CHKERRQ(ierr);
1635   ierr = PetscMemzero(cols,bi[mb]*sizeof(PetscInt));CHKERRQ(ierr);
1636   array = Bloc->a;
1637   row = A->rmap->rstart;
1638   for (i=0; i<bi[mb]; i++) {cols[i] = a->garray[bj[i]];}
1639   cols_tmp = cols;
1640   for (i=0; i<mb; i++) {
1641     ncol = bi[i+1]-bi[i];
1642     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1643     row++; array += ncol; cols_tmp += ncol;
1644   }
1645   ierr = PetscFree(cols);CHKERRQ(ierr);
1646 
1647   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1648   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1649   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
1650     *matout = B;
1651   } else {
1652     ierr = MatHeaderCopy(A,B);CHKERRQ(ierr);
1653   }
1654   PetscFunctionReturn(0);
1655 }
1656 
1657 #undef __FUNCT__
1658 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
1659 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
1660 {
1661   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1662   Mat            a = aij->A,b = aij->B;
1663   PetscErrorCode ierr;
1664   PetscInt       s1,s2,s3;
1665 
1666   PetscFunctionBegin;
1667   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
1668   if (rr) {
1669     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
1670     if (s1!=s3) SETERRQ(PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
1671     /* Overlap communication with computation. */
1672     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1673   }
1674   if (ll) {
1675     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
1676     if (s1!=s2) SETERRQ(PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
1677     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
1678   }
1679   /* scale  the diagonal block */
1680   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
1681 
1682   if (rr) {
1683     /* Do a scatter end and then right scale the off-diagonal block */
1684     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1685     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
1686   }
1687 
1688   PetscFunctionReturn(0);
1689 }
1690 
1691 #undef __FUNCT__
1692 #define __FUNCT__ "MatSetBlockSize_MPIAIJ"
1693 PetscErrorCode MatSetBlockSize_MPIAIJ(Mat A,PetscInt bs)
1694 {
1695   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1696   PetscErrorCode ierr;
1697 
1698   PetscFunctionBegin;
1699   ierr = MatSetBlockSize(a->A,bs);CHKERRQ(ierr);
1700   ierr = MatSetBlockSize(a->B,bs);CHKERRQ(ierr);
1701   PetscFunctionReturn(0);
1702 }
1703 #undef __FUNCT__
1704 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
1705 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
1706 {
1707   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1708   PetscErrorCode ierr;
1709 
1710   PetscFunctionBegin;
1711   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
1712   PetscFunctionReturn(0);
1713 }
1714 
1715 #undef __FUNCT__
1716 #define __FUNCT__ "MatEqual_MPIAIJ"
1717 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscTruth *flag)
1718 {
1719   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
1720   Mat            a,b,c,d;
1721   PetscTruth     flg;
1722   PetscErrorCode ierr;
1723 
1724   PetscFunctionBegin;
1725   a = matA->A; b = matA->B;
1726   c = matB->A; d = matB->B;
1727 
1728   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
1729   if (flg) {
1730     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
1731   }
1732   ierr = MPI_Allreduce(&flg,flag,1,MPI_INT,MPI_LAND,((PetscObject)A)->comm);CHKERRQ(ierr);
1733   PetscFunctionReturn(0);
1734 }
1735 
1736 #undef __FUNCT__
1737 #define __FUNCT__ "MatCopy_MPIAIJ"
1738 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
1739 {
1740   PetscErrorCode ierr;
1741   Mat_MPIAIJ     *a = (Mat_MPIAIJ *)A->data;
1742   Mat_MPIAIJ     *b = (Mat_MPIAIJ *)B->data;
1743 
1744   PetscFunctionBegin;
1745   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
1746   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
1747     /* because of the column compression in the off-processor part of the matrix a->B,
1748        the number of columns in a->B and b->B may be different, hence we cannot call
1749        the MatCopy() directly on the two parts. If need be, we can provide a more
1750        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
1751        then copying the submatrices */
1752     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
1753   } else {
1754     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
1755     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
1756   }
1757   PetscFunctionReturn(0);
1758 }
1759 
1760 #undef __FUNCT__
1761 #define __FUNCT__ "MatSetUpPreallocation_MPIAIJ"
1762 PetscErrorCode MatSetUpPreallocation_MPIAIJ(Mat A)
1763 {
1764   PetscErrorCode ierr;
1765 
1766   PetscFunctionBegin;
1767   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
1768   PetscFunctionReturn(0);
1769 }
1770 
1771 #include "petscblaslapack.h"
1772 #undef __FUNCT__
1773 #define __FUNCT__ "MatAXPY_MPIAIJ"
1774 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
1775 {
1776   PetscErrorCode ierr;
1777   PetscInt       i;
1778   Mat_MPIAIJ     *xx = (Mat_MPIAIJ *)X->data,*yy = (Mat_MPIAIJ *)Y->data;
1779   PetscBLASInt   bnz,one=1;
1780   Mat_SeqAIJ     *x,*y;
1781 
1782   PetscFunctionBegin;
1783   if (str == SAME_NONZERO_PATTERN) {
1784     PetscScalar alpha = a;
1785     x = (Mat_SeqAIJ *)xx->A->data;
1786     y = (Mat_SeqAIJ *)yy->A->data;
1787     bnz = PetscBLASIntCast(x->nz);
1788     BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one);
1789     x = (Mat_SeqAIJ *)xx->B->data;
1790     y = (Mat_SeqAIJ *)yy->B->data;
1791     bnz = PetscBLASIntCast(x->nz);
1792     BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one);
1793   } else if (str == SUBSET_NONZERO_PATTERN) {
1794     ierr = MatAXPY_SeqAIJ(yy->A,a,xx->A,str);CHKERRQ(ierr);
1795 
1796     x = (Mat_SeqAIJ *)xx->B->data;
1797     y = (Mat_SeqAIJ *)yy->B->data;
1798     if (y->xtoy && y->XtoY != xx->B) {
1799       ierr = PetscFree(y->xtoy);CHKERRQ(ierr);
1800       ierr = MatDestroy(y->XtoY);CHKERRQ(ierr);
1801     }
1802     if (!y->xtoy) { /* get xtoy */
1803       ierr = MatAXPYGetxtoy_Private(xx->B->rmap->n,x->i,x->j,xx->garray,y->i,y->j,yy->garray,&y->xtoy);CHKERRQ(ierr);
1804       y->XtoY = xx->B;
1805       ierr = PetscObjectReference((PetscObject)xx->B);CHKERRQ(ierr);
1806     }
1807     for (i=0; i<x->nz; i++) y->a[y->xtoy[i]] += a*(x->a[i]);
1808   } else {
1809     ierr = MatAXPY_Basic(Y,a,X,str);CHKERRQ(ierr);
1810   }
1811   PetscFunctionReturn(0);
1812 }
1813 
1814 EXTERN PetscErrorCode PETSCMAT_DLLEXPORT MatConjugate_SeqAIJ(Mat);
1815 
1816 #undef __FUNCT__
1817 #define __FUNCT__ "MatConjugate_MPIAIJ"
1818 PetscErrorCode PETSCMAT_DLLEXPORT MatConjugate_MPIAIJ(Mat mat)
1819 {
1820 #if defined(PETSC_USE_COMPLEX)
1821   PetscErrorCode ierr;
1822   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
1823 
1824   PetscFunctionBegin;
1825   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
1826   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
1827 #else
1828   PetscFunctionBegin;
1829 #endif
1830   PetscFunctionReturn(0);
1831 }
1832 
1833 #undef __FUNCT__
1834 #define __FUNCT__ "MatRealPart_MPIAIJ"
1835 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
1836 {
1837   Mat_MPIAIJ   *a = (Mat_MPIAIJ*)A->data;
1838   PetscErrorCode ierr;
1839 
1840   PetscFunctionBegin;
1841   ierr = MatRealPart(a->A);CHKERRQ(ierr);
1842   ierr = MatRealPart(a->B);CHKERRQ(ierr);
1843   PetscFunctionReturn(0);
1844 }
1845 
1846 #undef __FUNCT__
1847 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
1848 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
1849 {
1850   Mat_MPIAIJ   *a = (Mat_MPIAIJ*)A->data;
1851   PetscErrorCode ierr;
1852 
1853   PetscFunctionBegin;
1854   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
1855   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
1856   PetscFunctionReturn(0);
1857 }
1858 
1859 #ifdef PETSC_HAVE_PBGL
1860 
1861 #include <boost/parallel/mpi/bsp_process_group.hpp>
1862 #include <boost/graph/distributed/ilu_default_graph.hpp>
1863 #include <boost/graph/distributed/ilu_0_block.hpp>
1864 #include <boost/graph/distributed/ilu_preconditioner.hpp>
1865 #include <boost/graph/distributed/petsc/interface.hpp>
1866 #include <boost/multi_array.hpp>
1867 #include <boost/parallel/distributed_property_map->hpp>
1868 
1869 #undef __FUNCT__
1870 #define __FUNCT__ "MatILUFactorSymbolic_MPIAIJ"
1871 /*
1872   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
1873 */
1874 PetscErrorCode MatILUFactorSymbolic_MPIAIJ(Mat fact,Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
1875 {
1876   namespace petsc = boost::distributed::petsc;
1877 
1878   namespace graph_dist = boost::graph::distributed;
1879   using boost::graph::distributed::ilu_default::process_group_type;
1880   using boost::graph::ilu_permuted;
1881 
1882   PetscTruth      row_identity, col_identity;
1883   PetscContainer  c;
1884   PetscInt        m, n, M, N;
1885   PetscErrorCode  ierr;
1886 
1887   PetscFunctionBegin;
1888   if (info->levels != 0) SETERRQ(PETSC_ERR_SUP,"Only levels = 0 supported for parallel ilu");
1889   ierr = ISIdentity(isrow, &row_identity);CHKERRQ(ierr);
1890   ierr = ISIdentity(iscol, &col_identity);CHKERRQ(ierr);
1891   if (!row_identity || !col_identity) {
1892     SETERRQ(PETSC_ERR_ARG_WRONG,"Row and column permutations must be identity for parallel ILU");
1893   }
1894 
1895   process_group_type pg;
1896   typedef graph_dist::ilu_default::ilu_level_graph_type  lgraph_type;
1897   lgraph_type*   lgraph_p = new lgraph_type(petsc::num_global_vertices(A), pg, petsc::matrix_distribution(A, pg));
1898   lgraph_type&   level_graph = *lgraph_p;
1899   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
1900 
1901   petsc::read_matrix(A, graph, get(boost::edge_weight, graph));
1902   ilu_permuted(level_graph);
1903 
1904   /* put together the new matrix */
1905   ierr = MatCreate(((PetscObject)A)->comm, fact);CHKERRQ(ierr);
1906   ierr = MatGetLocalSize(A, &m, &n);CHKERRQ(ierr);
1907   ierr = MatGetSize(A, &M, &N);CHKERRQ(ierr);
1908   ierr = MatSetSizes(fact, m, n, M, N);CHKERRQ(ierr);
1909   ierr = MatSetType(fact, ((PetscObject)A)->type_name);CHKERRQ(ierr);
1910   ierr = MatAssemblyBegin(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1911   ierr = MatAssemblyEnd(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1912 
1913   ierr = PetscContainerCreate(((PetscObject)A)->comm, &c);
1914   ierr = PetscContainerSetPointer(c, lgraph_p);
1915   ierr = PetscObjectCompose((PetscObject) (fact), "graph", (PetscObject) c);
1916   PetscFunctionReturn(0);
1917 }
1918 
1919 #undef __FUNCT__
1920 #define __FUNCT__ "MatLUFactorNumeric_MPIAIJ"
1921 PetscErrorCode MatLUFactorNumeric_MPIAIJ(Mat B,Mat A, const MatFactorInfo *info)
1922 {
1923   PetscFunctionBegin;
1924   PetscFunctionReturn(0);
1925 }
1926 
1927 #undef __FUNCT__
1928 #define __FUNCT__ "MatSolve_MPIAIJ"
1929 /*
1930   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
1931 */
1932 PetscErrorCode MatSolve_MPIAIJ(Mat A, Vec b, Vec x)
1933 {
1934   namespace graph_dist = boost::graph::distributed;
1935 
1936   typedef graph_dist::ilu_default::ilu_level_graph_type  lgraph_type;
1937   lgraph_type*   lgraph_p;
1938   PetscContainer c;
1939   PetscErrorCode ierr;
1940 
1941   PetscFunctionBegin;
1942   ierr = PetscObjectQuery((PetscObject) A, "graph", (PetscObject *) &c);CHKERRQ(ierr);
1943   ierr = PetscContainerGetPointer(c, (void **) &lgraph_p);CHKERRQ(ierr);
1944   ierr = VecCopy(b, x);CHKERRQ(ierr);
1945 
1946   PetscScalar* array_x;
1947   ierr = VecGetArray(x, &array_x);CHKERRQ(ierr);
1948   PetscInt sx;
1949   ierr = VecGetSize(x, &sx);CHKERRQ(ierr);
1950 
1951   PetscScalar* array_b;
1952   ierr = VecGetArray(b, &array_b);CHKERRQ(ierr);
1953   PetscInt sb;
1954   ierr = VecGetSize(b, &sb);CHKERRQ(ierr);
1955 
1956   lgraph_type&   level_graph = *lgraph_p;
1957   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
1958 
1959   typedef boost::multi_array_ref<PetscScalar, 1> array_ref_type;
1960   array_ref_type                                 ref_b(array_b, boost::extents[num_vertices(graph)]),
1961                                                  ref_x(array_x, boost::extents[num_vertices(graph)]);
1962 
1963   typedef boost::iterator_property_map<array_ref_type::iterator,
1964                                 boost::property_map<graph_dist::ilu_default::graph_type, boost::vertex_index_t>::type>  gvector_type;
1965   gvector_type                                   vector_b(ref_b.begin(), get(boost::vertex_index, graph)),
1966                                                  vector_x(ref_x.begin(), get(boost::vertex_index, graph));
1967 
1968   ilu_set_solve(*lgraph_p, vector_b, vector_x);
1969 
1970   PetscFunctionReturn(0);
1971 }
1972 #endif
1973 
1974 typedef struct { /* used by MatGetRedundantMatrix() for reusing matredundant */
1975   PetscInt       nzlocal,nsends,nrecvs;
1976   PetscMPIInt    *send_rank;
1977   PetscInt       *sbuf_nz,*sbuf_j,**rbuf_j;
1978   PetscScalar    *sbuf_a,**rbuf_a;
1979   PetscErrorCode (*MatDestroy)(Mat);
1980 } Mat_Redundant;
1981 
1982 #undef __FUNCT__
1983 #define __FUNCT__ "PetscContainerDestroy_MatRedundant"
1984 PetscErrorCode PetscContainerDestroy_MatRedundant(void *ptr)
1985 {
1986   PetscErrorCode       ierr;
1987   Mat_Redundant        *redund=(Mat_Redundant*)ptr;
1988   PetscInt             i;
1989 
1990   PetscFunctionBegin;
1991   ierr = PetscFree(redund->send_rank);CHKERRQ(ierr);
1992   ierr = PetscFree(redund->sbuf_j);CHKERRQ(ierr);
1993   ierr = PetscFree(redund->sbuf_a);CHKERRQ(ierr);
1994   for (i=0; i<redund->nrecvs; i++){
1995     ierr = PetscFree(redund->rbuf_j[i]);CHKERRQ(ierr);
1996     ierr = PetscFree(redund->rbuf_a[i]);CHKERRQ(ierr);
1997   }
1998   ierr = PetscFree3(redund->sbuf_nz,redund->rbuf_j,redund->rbuf_a);CHKERRQ(ierr);
1999   ierr = PetscFree(redund);CHKERRQ(ierr);
2000   PetscFunctionReturn(0);
2001 }
2002 
2003 #undef __FUNCT__
2004 #define __FUNCT__ "MatDestroy_MatRedundant"
2005 PetscErrorCode MatDestroy_MatRedundant(Mat A)
2006 {
2007   PetscErrorCode  ierr;
2008   PetscContainer  container;
2009   Mat_Redundant   *redund=PETSC_NULL;
2010 
2011   PetscFunctionBegin;
2012   ierr = PetscObjectQuery((PetscObject)A,"Mat_Redundant",(PetscObject *)&container);CHKERRQ(ierr);
2013   if (container) {
2014     ierr = PetscContainerGetPointer(container,(void **)&redund);CHKERRQ(ierr);
2015   } else {
2016     SETERRQ(PETSC_ERR_PLIB,"Container does not exit");
2017   }
2018   A->ops->destroy = redund->MatDestroy;
2019   ierr = PetscObjectCompose((PetscObject)A,"Mat_Redundant",0);CHKERRQ(ierr);
2020   ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
2021   ierr = PetscContainerDestroy(container);CHKERRQ(ierr);
2022   PetscFunctionReturn(0);
2023 }
2024 
2025 #undef __FUNCT__
2026 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ"
2027 PetscErrorCode MatGetRedundantMatrix_MPIAIJ(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,PetscInt mlocal_sub,MatReuse reuse,Mat *matredundant)
2028 {
2029   PetscMPIInt    rank,size;
2030   MPI_Comm       comm=((PetscObject)mat)->comm;
2031   PetscErrorCode ierr;
2032   PetscInt       nsends=0,nrecvs=0,i,rownz_max=0;
2033   PetscMPIInt    *send_rank=PETSC_NULL,*recv_rank=PETSC_NULL;
2034   PetscInt       *rowrange=mat->rmap->range;
2035   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2036   Mat            A=aij->A,B=aij->B,C=*matredundant;
2037   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data;
2038   PetscScalar    *sbuf_a;
2039   PetscInt       nzlocal=a->nz+b->nz;
2040   PetscInt       j,cstart=mat->cmap->rstart,cend=mat->cmap->rend,row,nzA,nzB,ncols,*cworkA,*cworkB;
2041   PetscInt       rstart=mat->rmap->rstart,rend=mat->rmap->rend,*bmap=aij->garray,M,N;
2042   PetscInt       *cols,ctmp,lwrite,*rptr,l,*sbuf_j;
2043   MatScalar      *aworkA,*aworkB;
2044   PetscScalar    *vals;
2045   PetscMPIInt    tag1,tag2,tag3,imdex;
2046   MPI_Request    *s_waits1=PETSC_NULL,*s_waits2=PETSC_NULL,*s_waits3=PETSC_NULL,
2047                  *r_waits1=PETSC_NULL,*r_waits2=PETSC_NULL,*r_waits3=PETSC_NULL;
2048   MPI_Status     recv_status,*send_status;
2049   PetscInt       *sbuf_nz=PETSC_NULL,*rbuf_nz=PETSC_NULL,count;
2050   PetscInt       **rbuf_j=PETSC_NULL;
2051   PetscScalar    **rbuf_a=PETSC_NULL;
2052   Mat_Redundant  *redund=PETSC_NULL;
2053   PetscContainer container;
2054 
2055   PetscFunctionBegin;
2056   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2057   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2058 
2059   if (reuse == MAT_REUSE_MATRIX) {
2060     ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
2061     if (M != N || M != mat->rmap->N) SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong global size");
2062     ierr = MatGetLocalSize(C,&M,&N);CHKERRQ(ierr);
2063     if (M != N || M != mlocal_sub) SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong local size");
2064     ierr = PetscObjectQuery((PetscObject)C,"Mat_Redundant",(PetscObject *)&container);CHKERRQ(ierr);
2065     if (container) {
2066       ierr = PetscContainerGetPointer(container,(void **)&redund);CHKERRQ(ierr);
2067     } else {
2068       SETERRQ(PETSC_ERR_PLIB,"Container does not exit");
2069     }
2070     if (nzlocal != redund->nzlocal) SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong nzlocal");
2071 
2072     nsends    = redund->nsends;
2073     nrecvs    = redund->nrecvs;
2074     send_rank = redund->send_rank; recv_rank = send_rank + size;
2075     sbuf_nz   = redund->sbuf_nz;     rbuf_nz = sbuf_nz + nsends;
2076     sbuf_j    = redund->sbuf_j;
2077     sbuf_a    = redund->sbuf_a;
2078     rbuf_j    = redund->rbuf_j;
2079     rbuf_a    = redund->rbuf_a;
2080   }
2081 
2082   if (reuse == MAT_INITIAL_MATRIX){
2083     PetscMPIInt  subrank,subsize;
2084     PetscInt     nleftover,np_subcomm;
2085     /* get the destination processors' id send_rank, nsends and nrecvs */
2086     ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
2087     ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2088     ierr = PetscMalloc((2*size+1)*sizeof(PetscMPIInt),&send_rank);
2089     recv_rank = send_rank + size;
2090     np_subcomm = size/nsubcomm;
2091     nleftover  = size - nsubcomm*np_subcomm;
2092     nsends = 0; nrecvs = 0;
2093     for (i=0; i<size; i++){ /* i=rank*/
2094       if (subrank == i/nsubcomm && rank != i){ /* my_subrank == other's subrank */
2095         send_rank[nsends] = i; nsends++;
2096         recv_rank[nrecvs++] = i;
2097       }
2098     }
2099     if (rank >= size - nleftover){/* this proc is a leftover processor */
2100       i = size-nleftover-1;
2101       j = 0;
2102       while (j < nsubcomm - nleftover){
2103         send_rank[nsends++] = i;
2104         i--; j++;
2105       }
2106     }
2107 
2108     if (nleftover && subsize == size/nsubcomm && subrank==subsize-1){ /* this proc recvs from leftover processors */
2109       for (i=0; i<nleftover; i++){
2110         recv_rank[nrecvs++] = size-nleftover+i;
2111       }
2112     }
2113 
2114     /* allocate sbuf_j, sbuf_a */
2115     i = nzlocal + rowrange[rank+1] - rowrange[rank] + 2;
2116     ierr = PetscMalloc(i*sizeof(PetscInt),&sbuf_j);CHKERRQ(ierr);
2117     ierr = PetscMalloc((nzlocal+1)*sizeof(PetscScalar),&sbuf_a);CHKERRQ(ierr);
2118   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2119 
2120   /* copy mat's local entries into the buffers */
2121   if (reuse == MAT_INITIAL_MATRIX){
2122     rownz_max = 0;
2123     rptr = sbuf_j;
2124     cols = sbuf_j + rend-rstart + 1;
2125     vals = sbuf_a;
2126     rptr[0] = 0;
2127     for (i=0; i<rend-rstart; i++){
2128       row = i + rstart;
2129       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2130       ncols  = nzA + nzB;
2131       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2132       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2133       /* load the column indices for this row into cols */
2134       lwrite = 0;
2135       for (l=0; l<nzB; l++) {
2136         if ((ctmp = bmap[cworkB[l]]) < cstart){
2137           vals[lwrite]   = aworkB[l];
2138           cols[lwrite++] = ctmp;
2139         }
2140       }
2141       for (l=0; l<nzA; l++){
2142         vals[lwrite]   = aworkA[l];
2143         cols[lwrite++] = cstart + cworkA[l];
2144       }
2145       for (l=0; l<nzB; l++) {
2146         if ((ctmp = bmap[cworkB[l]]) >= cend){
2147           vals[lwrite]   = aworkB[l];
2148           cols[lwrite++] = ctmp;
2149         }
2150       }
2151       vals += ncols;
2152       cols += ncols;
2153       rptr[i+1] = rptr[i] + ncols;
2154       if (rownz_max < ncols) rownz_max = ncols;
2155     }
2156     if (rptr[rend-rstart] != a->nz + b->nz) SETERRQ4(1, "rptr[%d] %d != %d + %d",rend-rstart,rptr[rend-rstart+1],a->nz,b->nz);
2157   } else { /* only copy matrix values into sbuf_a */
2158     rptr = sbuf_j;
2159     vals = sbuf_a;
2160     rptr[0] = 0;
2161     for (i=0; i<rend-rstart; i++){
2162       row = i + rstart;
2163       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2164       ncols  = nzA + nzB;
2165       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2166       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2167       lwrite = 0;
2168       for (l=0; l<nzB; l++) {
2169         if ((ctmp = bmap[cworkB[l]]) < cstart) vals[lwrite++] = aworkB[l];
2170       }
2171       for (l=0; l<nzA; l++) vals[lwrite++] = aworkA[l];
2172       for (l=0; l<nzB; l++) {
2173         if ((ctmp = bmap[cworkB[l]]) >= cend) vals[lwrite++] = aworkB[l];
2174       }
2175       vals += ncols;
2176       rptr[i+1] = rptr[i] + ncols;
2177     }
2178   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2179 
2180   /* send nzlocal to others, and recv other's nzlocal */
2181   /*--------------------------------------------------*/
2182   if (reuse == MAT_INITIAL_MATRIX){
2183     ierr = PetscMalloc2(3*(nsends + nrecvs)+1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2184     s_waits2 = s_waits3 + nsends;
2185     s_waits1 = s_waits2 + nsends;
2186     r_waits1 = s_waits1 + nsends;
2187     r_waits2 = r_waits1 + nrecvs;
2188     r_waits3 = r_waits2 + nrecvs;
2189   } else {
2190     ierr = PetscMalloc2(nsends + nrecvs +1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2191     r_waits3 = s_waits3 + nsends;
2192   }
2193 
2194   ierr = PetscObjectGetNewTag((PetscObject)mat,&tag3);CHKERRQ(ierr);
2195   if (reuse == MAT_INITIAL_MATRIX){
2196     /* get new tags to keep the communication clean */
2197     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag1);CHKERRQ(ierr);
2198     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag2);CHKERRQ(ierr);
2199     ierr = PetscMalloc3(nsends+nrecvs+1,PetscInt,&sbuf_nz,nrecvs,PetscInt*,&rbuf_j,nrecvs,PetscScalar*,&rbuf_a);CHKERRQ(ierr);
2200     rbuf_nz = sbuf_nz + nsends;
2201 
2202     /* post receives of other's nzlocal */
2203     for (i=0; i<nrecvs; i++){
2204       ierr = MPI_Irecv(rbuf_nz+i,1,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,r_waits1+i);CHKERRQ(ierr);
2205     }
2206     /* send nzlocal to others */
2207     for (i=0; i<nsends; i++){
2208       sbuf_nz[i] = nzlocal;
2209       ierr = MPI_Isend(sbuf_nz+i,1,MPIU_INT,send_rank[i],tag1,comm,s_waits1+i);CHKERRQ(ierr);
2210     }
2211     /* wait on receives of nzlocal; allocate space for rbuf_j, rbuf_a */
2212     count = nrecvs;
2213     while (count) {
2214       ierr = MPI_Waitany(nrecvs,r_waits1,&imdex,&recv_status);CHKERRQ(ierr);
2215       recv_rank[imdex] = recv_status.MPI_SOURCE;
2216       /* allocate rbuf_a and rbuf_j; then post receives of rbuf_j */
2217       ierr = PetscMalloc((rbuf_nz[imdex]+1)*sizeof(PetscScalar),&rbuf_a[imdex]);CHKERRQ(ierr);
2218 
2219       i = rowrange[recv_status.MPI_SOURCE+1] - rowrange[recv_status.MPI_SOURCE]; /* number of expected mat->i */
2220       rbuf_nz[imdex] += i + 2;
2221       ierr = PetscMalloc(rbuf_nz[imdex]*sizeof(PetscInt),&rbuf_j[imdex]);CHKERRQ(ierr);
2222       ierr = MPI_Irecv(rbuf_j[imdex],rbuf_nz[imdex],MPIU_INT,recv_status.MPI_SOURCE,tag2,comm,r_waits2+imdex);CHKERRQ(ierr);
2223       count--;
2224     }
2225     /* wait on sends of nzlocal */
2226     if (nsends) {ierr = MPI_Waitall(nsends,s_waits1,send_status);CHKERRQ(ierr);}
2227     /* send mat->i,j to others, and recv from other's */
2228     /*------------------------------------------------*/
2229     for (i=0; i<nsends; i++){
2230       j = nzlocal + rowrange[rank+1] - rowrange[rank] + 1;
2231       ierr = MPI_Isend(sbuf_j,j,MPIU_INT,send_rank[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
2232     }
2233     /* wait on receives of mat->i,j */
2234     /*------------------------------*/
2235     count = nrecvs;
2236     while (count) {
2237       ierr = MPI_Waitany(nrecvs,r_waits2,&imdex,&recv_status);CHKERRQ(ierr);
2238       if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2239       count--;
2240     }
2241     /* wait on sends of mat->i,j */
2242     /*---------------------------*/
2243     if (nsends) {
2244       ierr = MPI_Waitall(nsends,s_waits2,send_status);CHKERRQ(ierr);
2245     }
2246   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2247 
2248   /* post receives, send and receive mat->a */
2249   /*----------------------------------------*/
2250   for (imdex=0; imdex<nrecvs; imdex++) {
2251     ierr = MPI_Irecv(rbuf_a[imdex],rbuf_nz[imdex],MPIU_SCALAR,recv_rank[imdex],tag3,comm,r_waits3+imdex);CHKERRQ(ierr);
2252   }
2253   for (i=0; i<nsends; i++){
2254     ierr = MPI_Isend(sbuf_a,nzlocal,MPIU_SCALAR,send_rank[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
2255   }
2256   count = nrecvs;
2257   while (count) {
2258     ierr = MPI_Waitany(nrecvs,r_waits3,&imdex,&recv_status);CHKERRQ(ierr);
2259     if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2260     count--;
2261   }
2262   if (nsends) {
2263     ierr = MPI_Waitall(nsends,s_waits3,send_status);CHKERRQ(ierr);
2264   }
2265 
2266   ierr = PetscFree2(s_waits3,send_status);CHKERRQ(ierr);
2267 
2268   /* create redundant matrix */
2269   /*-------------------------*/
2270   if (reuse == MAT_INITIAL_MATRIX){
2271     /* compute rownz_max for preallocation */
2272     for (imdex=0; imdex<nrecvs; imdex++){
2273       j = rowrange[recv_rank[imdex]+1] - rowrange[recv_rank[imdex]];
2274       rptr = rbuf_j[imdex];
2275       for (i=0; i<j; i++){
2276         ncols = rptr[i+1] - rptr[i];
2277         if (rownz_max < ncols) rownz_max = ncols;
2278       }
2279     }
2280 
2281     ierr = MatCreate(subcomm,&C);CHKERRQ(ierr);
2282     ierr = MatSetSizes(C,mlocal_sub,mlocal_sub,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
2283     ierr = MatSetFromOptions(C);CHKERRQ(ierr);
2284     ierr = MatSeqAIJSetPreallocation(C,rownz_max,PETSC_NULL);CHKERRQ(ierr);
2285     ierr = MatMPIAIJSetPreallocation(C,rownz_max,PETSC_NULL,rownz_max,PETSC_NULL);CHKERRQ(ierr);
2286   } else {
2287     C = *matredundant;
2288   }
2289 
2290   /* insert local matrix entries */
2291   rptr = sbuf_j;
2292   cols = sbuf_j + rend-rstart + 1;
2293   vals = sbuf_a;
2294   for (i=0; i<rend-rstart; i++){
2295     row   = i + rstart;
2296     ncols = rptr[i+1] - rptr[i];
2297     ierr = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2298     vals += ncols;
2299     cols += ncols;
2300   }
2301   /* insert received matrix entries */
2302   for (imdex=0; imdex<nrecvs; imdex++){
2303     rstart = rowrange[recv_rank[imdex]];
2304     rend   = rowrange[recv_rank[imdex]+1];
2305     rptr = rbuf_j[imdex];
2306     cols = rbuf_j[imdex] + rend-rstart + 1;
2307     vals = rbuf_a[imdex];
2308     for (i=0; i<rend-rstart; i++){
2309       row   = i + rstart;
2310       ncols = rptr[i+1] - rptr[i];
2311       ierr = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2312       vals += ncols;
2313       cols += ncols;
2314     }
2315   }
2316   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2317   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2318   ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
2319   if (M != mat->rmap->N || N != mat->cmap->N) SETERRQ2(PETSC_ERR_ARG_INCOMP,"redundant mat size %d != input mat size %d",M,mat->rmap->N);
2320   if (reuse == MAT_INITIAL_MATRIX){
2321     PetscContainer container;
2322     *matredundant = C;
2323     /* create a supporting struct and attach it to C for reuse */
2324     ierr = PetscNewLog(C,Mat_Redundant,&redund);CHKERRQ(ierr);
2325     ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
2326     ierr = PetscContainerSetPointer(container,redund);CHKERRQ(ierr);
2327     ierr = PetscObjectCompose((PetscObject)C,"Mat_Redundant",(PetscObject)container);CHKERRQ(ierr);
2328     ierr = PetscContainerSetUserDestroy(container,PetscContainerDestroy_MatRedundant);CHKERRQ(ierr);
2329 
2330     redund->nzlocal = nzlocal;
2331     redund->nsends  = nsends;
2332     redund->nrecvs  = nrecvs;
2333     redund->send_rank = send_rank;
2334     redund->sbuf_nz = sbuf_nz;
2335     redund->sbuf_j  = sbuf_j;
2336     redund->sbuf_a  = sbuf_a;
2337     redund->rbuf_j  = rbuf_j;
2338     redund->rbuf_a  = rbuf_a;
2339 
2340     redund->MatDestroy = C->ops->destroy;
2341     C->ops->destroy    = MatDestroy_MatRedundant;
2342   }
2343   PetscFunctionReturn(0);
2344 }
2345 
2346 #undef __FUNCT__
2347 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2348 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2349 {
2350   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2351   PetscErrorCode ierr;
2352   PetscInt       i,*idxb = 0;
2353   PetscScalar    *va,*vb;
2354   Vec            vtmp;
2355 
2356   PetscFunctionBegin;
2357   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2358   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2359   if (idx) {
2360     for (i=0; i<A->rmap->n; i++) {
2361       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2362     }
2363   }
2364 
2365   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2366   if (idx) {
2367     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
2368   }
2369   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2370   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2371 
2372   for (i=0; i<A->rmap->n; i++){
2373     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2374       va[i] = vb[i];
2375       if (idx) idx[i] = a->garray[idxb[i]];
2376     }
2377   }
2378 
2379   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2380   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2381   if (idxb) {
2382     ierr = PetscFree(idxb);CHKERRQ(ierr);
2383   }
2384   ierr = VecDestroy(vtmp);CHKERRQ(ierr);
2385   PetscFunctionReturn(0);
2386 }
2387 
2388 #undef __FUNCT__
2389 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2390 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2391 {
2392   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2393   PetscErrorCode ierr;
2394   PetscInt       i,*idxb = 0;
2395   PetscScalar    *va,*vb;
2396   Vec            vtmp;
2397 
2398   PetscFunctionBegin;
2399   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2400   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2401   if (idx) {
2402     for (i=0; i<A->cmap->n; i++) {
2403       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2404     }
2405   }
2406 
2407   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2408   if (idx) {
2409     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
2410   }
2411   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2412   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2413 
2414   for (i=0; i<A->rmap->n; i++){
2415     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2416       va[i] = vb[i];
2417       if (idx) idx[i] = a->garray[idxb[i]];
2418     }
2419   }
2420 
2421   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2422   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2423   if (idxb) {
2424     ierr = PetscFree(idxb);CHKERRQ(ierr);
2425   }
2426   ierr = VecDestroy(vtmp);CHKERRQ(ierr);
2427   PetscFunctionReturn(0);
2428 }
2429 
2430 #undef __FUNCT__
2431 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2432 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2433 {
2434   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
2435   PetscInt       n      = A->rmap->n;
2436   PetscInt       cstart = A->cmap->rstart;
2437   PetscInt      *cmap   = mat->garray;
2438   PetscInt      *diagIdx, *offdiagIdx;
2439   Vec            diagV, offdiagV;
2440   PetscScalar   *a, *diagA, *offdiagA;
2441   PetscInt       r;
2442   PetscErrorCode ierr;
2443 
2444   PetscFunctionBegin;
2445   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
2446   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &diagV);CHKERRQ(ierr);
2447   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &offdiagV);CHKERRQ(ierr);
2448   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2449   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2450   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2451   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2452   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2453   for(r = 0; r < n; ++r) {
2454     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2455       a[r]   = diagA[r];
2456       idx[r] = cstart + diagIdx[r];
2457     } else {
2458       a[r]   = offdiagA[r];
2459       idx[r] = cmap[offdiagIdx[r]];
2460     }
2461   }
2462   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2463   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2464   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2465   ierr = VecDestroy(diagV);CHKERRQ(ierr);
2466   ierr = VecDestroy(offdiagV);CHKERRQ(ierr);
2467   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2468   PetscFunctionReturn(0);
2469 }
2470 
2471 #undef __FUNCT__
2472 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2473 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2474 {
2475   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
2476   PetscInt       n      = A->rmap->n;
2477   PetscInt       cstart = A->cmap->rstart;
2478   PetscInt      *cmap   = mat->garray;
2479   PetscInt      *diagIdx, *offdiagIdx;
2480   Vec            diagV, offdiagV;
2481   PetscScalar   *a, *diagA, *offdiagA;
2482   PetscInt       r;
2483   PetscErrorCode ierr;
2484 
2485   PetscFunctionBegin;
2486   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
2487   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &diagV);CHKERRQ(ierr);
2488   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &offdiagV);CHKERRQ(ierr);
2489   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2490   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2491   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2492   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2493   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2494   for(r = 0; r < n; ++r) {
2495     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2496       a[r]   = diagA[r];
2497       idx[r] = cstart + diagIdx[r];
2498     } else {
2499       a[r]   = offdiagA[r];
2500       idx[r] = cmap[offdiagIdx[r]];
2501     }
2502   }
2503   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2504   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2505   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2506   ierr = VecDestroy(diagV);CHKERRQ(ierr);
2507   ierr = VecDestroy(offdiagV);CHKERRQ(ierr);
2508   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2509   PetscFunctionReturn(0);
2510 }
2511 
2512 #undef __FUNCT__
2513 #define __FUNCT__ "MatGetSeqNonzerostructure_MPIAIJ"
2514 PetscErrorCode MatGetSeqNonzerostructure_MPIAIJ(Mat mat,Mat *newmat[])
2515 {
2516   PetscErrorCode ierr;
2517 
2518   PetscFunctionBegin;
2519   ierr = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,newmat);CHKERRQ(ierr);
2520   PetscFunctionReturn(0);
2521 }
2522 
2523 /* -------------------------------------------------------------------*/
2524 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
2525        MatGetRow_MPIAIJ,
2526        MatRestoreRow_MPIAIJ,
2527        MatMult_MPIAIJ,
2528 /* 4*/ MatMultAdd_MPIAIJ,
2529        MatMultTranspose_MPIAIJ,
2530        MatMultTransposeAdd_MPIAIJ,
2531 #ifdef PETSC_HAVE_PBGL
2532        MatSolve_MPIAIJ,
2533 #else
2534        0,
2535 #endif
2536        0,
2537        0,
2538 /*10*/ 0,
2539        0,
2540        0,
2541        MatRelax_MPIAIJ,
2542        MatTranspose_MPIAIJ,
2543 /*15*/ MatGetInfo_MPIAIJ,
2544        MatEqual_MPIAIJ,
2545        MatGetDiagonal_MPIAIJ,
2546        MatDiagonalScale_MPIAIJ,
2547        MatNorm_MPIAIJ,
2548 /*20*/ MatAssemblyBegin_MPIAIJ,
2549        MatAssemblyEnd_MPIAIJ,
2550        0,
2551        MatSetOption_MPIAIJ,
2552        MatZeroEntries_MPIAIJ,
2553 /*25*/ MatZeroRows_MPIAIJ,
2554        0,
2555 #ifdef PETSC_HAVE_PBGL
2556        0,
2557 #else
2558        0,
2559 #endif
2560        0,
2561        0,
2562 /*30*/ MatSetUpPreallocation_MPIAIJ,
2563 #ifdef PETSC_HAVE_PBGL
2564        0,
2565 #else
2566        0,
2567 #endif
2568        0,
2569        0,
2570        0,
2571 /*35*/ MatDuplicate_MPIAIJ,
2572        0,
2573        0,
2574        0,
2575        0,
2576 /*40*/ MatAXPY_MPIAIJ,
2577        MatGetSubMatrices_MPIAIJ,
2578        MatIncreaseOverlap_MPIAIJ,
2579        MatGetValues_MPIAIJ,
2580        MatCopy_MPIAIJ,
2581 /*45*/ MatGetRowMax_MPIAIJ,
2582        MatScale_MPIAIJ,
2583        0,
2584        0,
2585        0,
2586 /*50*/ MatSetBlockSize_MPIAIJ,
2587        0,
2588        0,
2589        0,
2590        0,
2591 /*55*/ MatFDColoringCreate_MPIAIJ,
2592        0,
2593        MatSetUnfactored_MPIAIJ,
2594        MatPermute_MPIAIJ,
2595        0,
2596 /*60*/ MatGetSubMatrix_MPIAIJ,
2597        MatDestroy_MPIAIJ,
2598        MatView_MPIAIJ,
2599        0,
2600        0,
2601 /*65*/ 0,
2602        0,
2603        0,
2604        0,
2605        0,
2606 /*70*/ MatGetRowMaxAbs_MPIAIJ,
2607        MatGetRowMinAbs_MPIAIJ,
2608        0,
2609        MatSetColoring_MPIAIJ,
2610 #if defined(PETSC_HAVE_ADIC)
2611        MatSetValuesAdic_MPIAIJ,
2612 #else
2613        0,
2614 #endif
2615        MatSetValuesAdifor_MPIAIJ,
2616 /*75*/ 0,
2617        0,
2618        0,
2619        0,
2620        0,
2621 /*80*/ 0,
2622        0,
2623        0,
2624 /*84*/ MatLoad_MPIAIJ,
2625        0,
2626        0,
2627        0,
2628        0,
2629        0,
2630 /*90*/ MatMatMult_MPIAIJ_MPIAIJ,
2631        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
2632        MatMatMultNumeric_MPIAIJ_MPIAIJ,
2633        MatPtAP_Basic,
2634        MatPtAPSymbolic_MPIAIJ,
2635 /*95*/ MatPtAPNumeric_MPIAIJ,
2636        0,
2637        0,
2638        0,
2639        0,
2640 /*100*/0,
2641        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
2642        MatPtAPNumeric_MPIAIJ_MPIAIJ,
2643        MatConjugate_MPIAIJ,
2644        0,
2645 /*105*/MatSetValuesRow_MPIAIJ,
2646        MatRealPart_MPIAIJ,
2647        MatImaginaryPart_MPIAIJ,
2648        0,
2649        0,
2650 /*110*/0,
2651        MatGetRedundantMatrix_MPIAIJ,
2652        MatGetRowMin_MPIAIJ,
2653        0,
2654        0,
2655 /*115*/MatGetSeqNonzerostructure_MPIAIJ};
2656 
2657 /* ----------------------------------------------------------------------------------------*/
2658 
2659 EXTERN_C_BEGIN
2660 #undef __FUNCT__
2661 #define __FUNCT__ "MatStoreValues_MPIAIJ"
2662 PetscErrorCode PETSCMAT_DLLEXPORT MatStoreValues_MPIAIJ(Mat mat)
2663 {
2664   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
2665   PetscErrorCode ierr;
2666 
2667   PetscFunctionBegin;
2668   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
2669   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
2670   PetscFunctionReturn(0);
2671 }
2672 EXTERN_C_END
2673 
2674 EXTERN_C_BEGIN
2675 #undef __FUNCT__
2676 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
2677 PetscErrorCode PETSCMAT_DLLEXPORT MatRetrieveValues_MPIAIJ(Mat mat)
2678 {
2679   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
2680   PetscErrorCode ierr;
2681 
2682   PetscFunctionBegin;
2683   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
2684   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
2685   PetscFunctionReturn(0);
2686 }
2687 EXTERN_C_END
2688 
2689 #include "petscpc.h"
2690 EXTERN_C_BEGIN
2691 #undef __FUNCT__
2692 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
2693 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
2694 {
2695   Mat_MPIAIJ     *b;
2696   PetscErrorCode ierr;
2697   PetscInt       i;
2698 
2699   PetscFunctionBegin;
2700   B->preallocated = PETSC_TRUE;
2701   if (d_nz == PETSC_DEFAULT || d_nz == PETSC_DECIDE) d_nz = 5;
2702   if (o_nz == PETSC_DEFAULT || o_nz == PETSC_DECIDE) o_nz = 2;
2703   if (d_nz < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"d_nz cannot be less than 0: value %D",d_nz);
2704   if (o_nz < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"o_nz cannot be less than 0: value %D",o_nz);
2705 
2706   ierr = PetscMapSetBlockSize(B->rmap,1);CHKERRQ(ierr);
2707   ierr = PetscMapSetBlockSize(B->cmap,1);CHKERRQ(ierr);
2708   ierr = PetscMapSetUp(B->rmap);CHKERRQ(ierr);
2709   ierr = PetscMapSetUp(B->cmap);CHKERRQ(ierr);
2710   if (d_nnz) {
2711     for (i=0; i<B->rmap->n; i++) {
2712       if (d_nnz[i] < 0) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"d_nnz cannot be less than 0: local row %D value %D",i,d_nnz[i]);
2713     }
2714   }
2715   if (o_nnz) {
2716     for (i=0; i<B->rmap->n; i++) {
2717       if (o_nnz[i] < 0) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"o_nnz cannot be less than 0: local row %D value %D",i,o_nnz[i]);
2718     }
2719   }
2720   b = (Mat_MPIAIJ*)B->data;
2721 
2722   /* Explicitly create 2 MATSEQAIJ matrices. */
2723   ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
2724   ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
2725   ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
2726   ierr = PetscLogObjectParent(B,b->A);CHKERRQ(ierr);
2727   ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
2728   ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
2729   ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
2730   ierr = PetscLogObjectParent(B,b->B);CHKERRQ(ierr);
2731 
2732   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
2733   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
2734 
2735   PetscFunctionReturn(0);
2736 }
2737 EXTERN_C_END
2738 
2739 #undef __FUNCT__
2740 #define __FUNCT__ "MatDuplicate_MPIAIJ"
2741 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
2742 {
2743   Mat            mat;
2744   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
2745   PetscErrorCode ierr;
2746 
2747   PetscFunctionBegin;
2748   *newmat       = 0;
2749   ierr = MatCreate(((PetscObject)matin)->comm,&mat);CHKERRQ(ierr);
2750   ierr = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
2751   ierr = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
2752   ierr = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
2753   a    = (Mat_MPIAIJ*)mat->data;
2754 
2755   mat->factor       = matin->factor;
2756   mat->rmap->bs      = matin->rmap->bs;
2757   mat->assembled    = PETSC_TRUE;
2758   mat->insertmode   = NOT_SET_VALUES;
2759   mat->preallocated = PETSC_TRUE;
2760 
2761   a->size           = oldmat->size;
2762   a->rank           = oldmat->rank;
2763   a->donotstash     = oldmat->donotstash;
2764   a->roworiented    = oldmat->roworiented;
2765   a->rowindices     = 0;
2766   a->rowvalues      = 0;
2767   a->getrowactive   = PETSC_FALSE;
2768 
2769   ierr = PetscMapCopy(((PetscObject)mat)->comm,matin->rmap,mat->rmap);CHKERRQ(ierr);
2770   ierr = PetscMapCopy(((PetscObject)mat)->comm,matin->cmap,mat->cmap);CHKERRQ(ierr);
2771 
2772   ierr = MatStashCreate_Private(((PetscObject)matin)->comm,1,&mat->stash);CHKERRQ(ierr);
2773   if (oldmat->colmap) {
2774 #if defined (PETSC_USE_CTABLE)
2775     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
2776 #else
2777     ierr = PetscMalloc((mat->cmap->N)*sizeof(PetscInt),&a->colmap);CHKERRQ(ierr);
2778     ierr = PetscLogObjectMemory(mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2779     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2780 #endif
2781   } else a->colmap = 0;
2782   if (oldmat->garray) {
2783     PetscInt len;
2784     len  = oldmat->B->cmap->n;
2785     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&a->garray);CHKERRQ(ierr);
2786     ierr = PetscLogObjectMemory(mat,len*sizeof(PetscInt));CHKERRQ(ierr);
2787     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
2788   } else a->garray = 0;
2789 
2790   ierr = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
2791   ierr = PetscLogObjectParent(mat,a->lvec);CHKERRQ(ierr);
2792   ierr = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
2793   ierr = PetscLogObjectParent(mat,a->Mvctx);CHKERRQ(ierr);
2794   ierr = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
2795   ierr = PetscLogObjectParent(mat,a->A);CHKERRQ(ierr);
2796   ierr = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
2797   ierr = PetscLogObjectParent(mat,a->B);CHKERRQ(ierr);
2798   ierr = PetscFListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
2799   *newmat = mat;
2800   PetscFunctionReturn(0);
2801 }
2802 
2803 #include "petscsys.h"
2804 
2805 #undef __FUNCT__
2806 #define __FUNCT__ "MatLoad_MPIAIJ"
2807 PetscErrorCode MatLoad_MPIAIJ(PetscViewer viewer, const MatType type,Mat *newmat)
2808 {
2809   Mat            A;
2810   PetscScalar    *vals,*svals;
2811   MPI_Comm       comm = ((PetscObject)viewer)->comm;
2812   MPI_Status     status;
2813   PetscErrorCode ierr;
2814   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag,maxnz;
2815   PetscInt       i,nz,j,rstart,rend,mmax;
2816   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
2817   PetscInt       *ourlens = PETSC_NULL,*procsnz = PETSC_NULL,*offlens = PETSC_NULL,jj,*mycols,*smycols;
2818   PetscInt       cend,cstart,n,*rowners;
2819   int            fd;
2820 
2821   PetscFunctionBegin;
2822   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2823   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2824   if (!rank) {
2825     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
2826     ierr = PetscBinaryRead(fd,(char *)header,4,PETSC_INT);CHKERRQ(ierr);
2827     if (header[0] != MAT_FILE_COOKIE) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
2828   }
2829 
2830   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
2831   M = header[1]; N = header[2];
2832   /* determine ownership of all rows */
2833   m    = M/size + ((M % size) > rank);
2834   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
2835   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
2836 
2837   /* First process needs enough room for process with most rows */
2838   if (!rank) {
2839     mmax       = rowners[1];
2840     for (i=2; i<size; i++) {
2841       mmax = PetscMax(mmax,rowners[i]);
2842     }
2843   } else mmax = m;
2844 
2845   rowners[0] = 0;
2846   for (i=2; i<=size; i++) {
2847     rowners[i] += rowners[i-1];
2848   }
2849   rstart = rowners[rank];
2850   rend   = rowners[rank+1];
2851 
2852   /* distribute row lengths to all processors */
2853   ierr    = PetscMalloc2(mmax,PetscInt,&ourlens,mmax,PetscInt,&offlens);CHKERRQ(ierr);
2854   if (!rank) {
2855     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
2856     ierr = PetscMalloc(m*sizeof(PetscInt),&rowlengths);CHKERRQ(ierr);
2857     ierr = PetscMalloc(size*sizeof(PetscInt),&procsnz);CHKERRQ(ierr);
2858     ierr = PetscMemzero(procsnz,size*sizeof(PetscInt));CHKERRQ(ierr);
2859     for (j=0; j<m; j++) {
2860       procsnz[0] += ourlens[j];
2861     }
2862     for (i=1; i<size; i++) {
2863       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
2864       /* calculate the number of nonzeros on each processor */
2865       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
2866         procsnz[i] += rowlengths[j];
2867       }
2868       ierr = MPI_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2869     }
2870     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
2871   } else {
2872     ierr = MPI_Recv(ourlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
2873   }
2874 
2875   if (!rank) {
2876     /* determine max buffer needed and allocate it */
2877     maxnz = 0;
2878     for (i=0; i<size; i++) {
2879       maxnz = PetscMax(maxnz,procsnz[i]);
2880     }
2881     ierr = PetscMalloc(maxnz*sizeof(PetscInt),&cols);CHKERRQ(ierr);
2882 
2883     /* read in my part of the matrix column indices  */
2884     nz   = procsnz[0];
2885     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
2886     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
2887 
2888     /* read in every one elses and ship off */
2889     for (i=1; i<size; i++) {
2890       nz   = procsnz[i];
2891       ierr = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
2892       ierr = MPI_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2893     }
2894     ierr = PetscFree(cols);CHKERRQ(ierr);
2895   } else {
2896     /* determine buffer space needed for message */
2897     nz = 0;
2898     for (i=0; i<m; i++) {
2899       nz += ourlens[i];
2900     }
2901     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
2902 
2903     /* receive message of column indices*/
2904     ierr = MPI_Recv(mycols,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
2905     ierr = MPI_Get_count(&status,MPIU_INT,&maxnz);CHKERRQ(ierr);
2906     if (maxnz != nz) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"something is wrong with file");
2907   }
2908 
2909   /* determine column ownership if matrix is not square */
2910   if (N != M) {
2911     n      = N/size + ((N % size) > rank);
2912     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
2913     cstart = cend - n;
2914   } else {
2915     cstart = rstart;
2916     cend   = rend;
2917     n      = cend - cstart;
2918   }
2919 
2920   /* loop over local rows, determining number of off diagonal entries */
2921   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
2922   jj = 0;
2923   for (i=0; i<m; i++) {
2924     for (j=0; j<ourlens[i]; j++) {
2925       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
2926       jj++;
2927     }
2928   }
2929 
2930   /* create our matrix */
2931   for (i=0; i<m; i++) {
2932     ourlens[i] -= offlens[i];
2933   }
2934   ierr = MatCreate(comm,&A);CHKERRQ(ierr);
2935   ierr = MatSetSizes(A,m,n,M,N);CHKERRQ(ierr);
2936   ierr = MatSetType(A,type);CHKERRQ(ierr);
2937   ierr = MatMPIAIJSetPreallocation(A,0,ourlens,0,offlens);CHKERRQ(ierr);
2938 
2939   for (i=0; i<m; i++) {
2940     ourlens[i] += offlens[i];
2941   }
2942 
2943   if (!rank) {
2944     ierr = PetscMalloc((maxnz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
2945 
2946     /* read in my part of the matrix numerical values  */
2947     nz   = procsnz[0];
2948     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2949 
2950     /* insert into matrix */
2951     jj      = rstart;
2952     smycols = mycols;
2953     svals   = vals;
2954     for (i=0; i<m; i++) {
2955       ierr = MatSetValues_MPIAIJ(A,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2956       smycols += ourlens[i];
2957       svals   += ourlens[i];
2958       jj++;
2959     }
2960 
2961     /* read in other processors and ship out */
2962     for (i=1; i<size; i++) {
2963       nz   = procsnz[i];
2964       ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2965       ierr = MPI_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)A)->tag,comm);CHKERRQ(ierr);
2966     }
2967     ierr = PetscFree(procsnz);CHKERRQ(ierr);
2968   } else {
2969     /* receive numeric values */
2970     ierr = PetscMalloc((nz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
2971 
2972     /* receive message of values*/
2973     ierr = MPI_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)A)->tag,comm,&status);CHKERRQ(ierr);
2974     ierr = MPI_Get_count(&status,MPIU_SCALAR,&maxnz);CHKERRQ(ierr);
2975     if (maxnz != nz) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"something is wrong with file");
2976 
2977     /* insert into matrix */
2978     jj      = rstart;
2979     smycols = mycols;
2980     svals   = vals;
2981     for (i=0; i<m; i++) {
2982       ierr     = MatSetValues_MPIAIJ(A,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2983       smycols += ourlens[i];
2984       svals   += ourlens[i];
2985       jj++;
2986     }
2987   }
2988   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
2989   ierr = PetscFree(vals);CHKERRQ(ierr);
2990   ierr = PetscFree(mycols);CHKERRQ(ierr);
2991   ierr = PetscFree(rowners);CHKERRQ(ierr);
2992 
2993   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2994   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2995   *newmat = A;
2996   PetscFunctionReturn(0);
2997 }
2998 
2999 #undef __FUNCT__
3000 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3001 /*
3002     Not great since it makes two copies of the submatrix, first an SeqAIJ
3003   in local and then by concatenating the local matrices the end result.
3004   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3005 */
3006 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3007 {
3008   PetscErrorCode ierr;
3009   PetscMPIInt    rank,size;
3010   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j;
3011   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal;
3012   Mat            *local,M,Mreuse;
3013   MatScalar      *vwork,*aa;
3014   MPI_Comm       comm = ((PetscObject)mat)->comm;
3015   Mat_SeqAIJ     *aij;
3016 
3017 
3018   PetscFunctionBegin;
3019   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3020   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3021 
3022   if (call ==  MAT_REUSE_MATRIX) {
3023     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject *)&Mreuse);CHKERRQ(ierr);
3024     if (!Mreuse) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3025     local = &Mreuse;
3026     ierr  = MatGetSubMatrices(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&local);CHKERRQ(ierr);
3027   } else {
3028     ierr   = MatGetSubMatrices(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&local);CHKERRQ(ierr);
3029     Mreuse = *local;
3030     ierr   = PetscFree(local);CHKERRQ(ierr);
3031   }
3032 
3033   /*
3034       m - number of local rows
3035       n - number of columns (same on all processors)
3036       rstart - first row in new global matrix generated
3037   */
3038   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3039   if (call == MAT_INITIAL_MATRIX) {
3040     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3041     ii  = aij->i;
3042     jj  = aij->j;
3043 
3044     /*
3045         Determine the number of non-zeros in the diagonal and off-diagonal
3046         portions of the matrix in order to do correct preallocation
3047     */
3048 
3049     /* first get start and end of "diagonal" columns */
3050     if (csize == PETSC_DECIDE) {
3051       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3052       if (mglobal == n) { /* square matrix */
3053 	nlocal = m;
3054       } else {
3055         nlocal = n/size + ((n % size) > rank);
3056       }
3057     } else {
3058       nlocal = csize;
3059     }
3060     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3061     rstart = rend - nlocal;
3062     if (rank == size - 1 && rend != n) {
3063       SETERRQ2(PETSC_ERR_ARG_SIZ,"Local column sizes %D do not add up to total number of columns %D",rend,n);
3064     }
3065 
3066     /* next, compute all the lengths */
3067     ierr  = PetscMalloc((2*m+1)*sizeof(PetscInt),&dlens);CHKERRQ(ierr);
3068     olens = dlens + m;
3069     for (i=0; i<m; i++) {
3070       jend = ii[i+1] - ii[i];
3071       olen = 0;
3072       dlen = 0;
3073       for (j=0; j<jend; j++) {
3074         if (*jj < rstart || *jj >= rend) olen++;
3075         else dlen++;
3076         jj++;
3077       }
3078       olens[i] = olen;
3079       dlens[i] = dlen;
3080     }
3081     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3082     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3083     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3084     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3085     ierr = PetscFree(dlens);CHKERRQ(ierr);
3086   } else {
3087     PetscInt ml,nl;
3088 
3089     M = *newmat;
3090     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3091     if (ml != m) SETERRQ(PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3092     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3093     /*
3094          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3095        rather than the slower MatSetValues().
3096     */
3097     M->was_assembled = PETSC_TRUE;
3098     M->assembled     = PETSC_FALSE;
3099   }
3100   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3101   aij = (Mat_SeqAIJ*)(Mreuse)->data;
3102   ii  = aij->i;
3103   jj  = aij->j;
3104   aa  = aij->a;
3105   for (i=0; i<m; i++) {
3106     row   = rstart + i;
3107     nz    = ii[i+1] - ii[i];
3108     cwork = jj;     jj += nz;
3109     vwork = aa;     aa += nz;
3110     ierr = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3111   }
3112 
3113   ierr = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3114   ierr = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3115   *newmat = M;
3116 
3117   /* save submatrix used in processor for next request */
3118   if (call ==  MAT_INITIAL_MATRIX) {
3119     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3120     ierr = PetscObjectDereference((PetscObject)Mreuse);CHKERRQ(ierr);
3121   }
3122 
3123   PetscFunctionReturn(0);
3124 }
3125 
3126 EXTERN_C_BEGIN
3127 #undef __FUNCT__
3128 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3129 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3130 {
3131   PetscInt       m,cstart, cend,j,nnz,i,d;
3132   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3133   const PetscInt *JJ;
3134   PetscScalar    *values;
3135   PetscErrorCode ierr;
3136 
3137   PetscFunctionBegin;
3138   if (Ii[0]) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3139 
3140   ierr = PetscMapSetBlockSize(B->rmap,1);CHKERRQ(ierr);
3141   ierr = PetscMapSetBlockSize(B->cmap,1);CHKERRQ(ierr);
3142   ierr = PetscMapSetUp(B->rmap);CHKERRQ(ierr);
3143   ierr = PetscMapSetUp(B->cmap);CHKERRQ(ierr);
3144   m      = B->rmap->n;
3145   cstart = B->cmap->rstart;
3146   cend   = B->cmap->rend;
3147   rstart = B->rmap->rstart;
3148 
3149   ierr  = PetscMalloc((2*m+1)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr);
3150   o_nnz = d_nnz + m;
3151 
3152 #if defined(PETSC_USE_DEBUGGING)
3153   for (i=0; i<m; i++) {
3154     nnz     = Ii[i+1]- Ii[i];
3155     JJ      = J + Ii[i];
3156     if (nnz < 0) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3157     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3158     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);
3159     for (j=1; j<nnz; j++) {
3160       if (JJ[i] <= JJ[i-1]) SETERRRQ(PETSC_ERR_ARG_WRONGSTATE,"Row %D has unsorted column index at %D location in column indices",i,j);
3161     }
3162   }
3163 #endif
3164 
3165   for (i=0; i<m; i++) {
3166     nnz     = Ii[i+1]- Ii[i];
3167     JJ      = J + Ii[i];
3168     nnz_max = PetscMax(nnz_max,nnz);
3169     for (j=0; j<nnz; j++) {
3170       if (*JJ >= cstart) break;
3171       JJ++;
3172     }
3173     d = 0;
3174     for (; j<nnz; j++) {
3175       if (*JJ++ >= cend) break;
3176       d++;
3177     }
3178     d_nnz[i] = d;
3179     o_nnz[i] = nnz - d;
3180   }
3181   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3182   ierr = PetscFree(d_nnz);CHKERRQ(ierr);
3183 
3184   if (v) values = (PetscScalar*)v;
3185   else {
3186     ierr = PetscMalloc((nnz_max+1)*sizeof(PetscScalar),&values);CHKERRQ(ierr);
3187     ierr = PetscMemzero(values,nnz_max*sizeof(PetscScalar));CHKERRQ(ierr);
3188   }
3189 
3190   for (i=0; i<m; i++) {
3191     ii   = i + rstart;
3192     nnz  = Ii[i+1]- Ii[i];
3193     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3194   }
3195   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3196   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3197 
3198   if (!v) {
3199     ierr = PetscFree(values);CHKERRQ(ierr);
3200   }
3201   PetscFunctionReturn(0);
3202 }
3203 EXTERN_C_END
3204 
3205 #undef __FUNCT__
3206 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3207 /*@
3208    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3209    (the default parallel PETSc format).
3210 
3211    Collective on MPI_Comm
3212 
3213    Input Parameters:
3214 +  B - the matrix
3215 .  i - the indices into j for the start of each local row (starts with zero)
3216 .  j - the column indices for each local row (starts with zero) these must be sorted for each row
3217 -  v - optional values in the matrix
3218 
3219    Level: developer
3220 
3221    Notes:
3222        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3223      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3224      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3225 
3226        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3227 
3228        The format which is used for the sparse matrix input, is equivalent to a
3229     row-major ordering.. i.e for the following matrix, the input data expected is
3230     as shown:
3231 
3232         1 0 0
3233         2 0 3     P0
3234        -------
3235         4 5 6     P1
3236 
3237      Process0 [P0]: rows_owned=[0,1]
3238         i =  {0,1,3}  [size = nrow+1  = 2+1]
3239         j =  {0,0,2}  [size = nz = 6]
3240         v =  {1,2,3}  [size = nz = 6]
3241 
3242      Process1 [P1]: rows_owned=[2]
3243         i =  {0,3}    [size = nrow+1  = 1+1]
3244         j =  {0,1,2}  [size = nz = 6]
3245         v =  {4,5,6}  [size = nz = 6]
3246 
3247       The column indices for each row MUST be sorted.
3248 
3249 .keywords: matrix, aij, compressed row, sparse, parallel
3250 
3251 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateMPIAIJ(), MPIAIJ,
3252           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3253 @*/
3254 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3255 {
3256   PetscErrorCode ierr,(*f)(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]);
3257 
3258   PetscFunctionBegin;
3259   ierr = PetscObjectQueryFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",(void (**)(void))&f);CHKERRQ(ierr);
3260   if (f) {
3261     ierr = (*f)(B,i,j,v);CHKERRQ(ierr);
3262   }
3263   PetscFunctionReturn(0);
3264 }
3265 
3266 #undef __FUNCT__
3267 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3268 /*@C
3269    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3270    (the default parallel PETSc format).  For good matrix assembly performance
3271    the user should preallocate the matrix storage by setting the parameters
3272    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3273    performance can be increased by more than a factor of 50.
3274 
3275    Collective on MPI_Comm
3276 
3277    Input Parameters:
3278 +  A - the matrix
3279 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3280            (same value is used for all local rows)
3281 .  d_nnz - array containing the number of nonzeros in the various rows of the
3282            DIAGONAL portion of the local submatrix (possibly different for each row)
3283            or PETSC_NULL, if d_nz is used to specify the nonzero structure.
3284            The size of this array is equal to the number of local rows, i.e 'm'.
3285            You must leave room for the diagonal entry even if it is zero.
3286 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3287            submatrix (same value is used for all local rows).
3288 -  o_nnz - array containing the number of nonzeros in the various rows of the
3289            OFF-DIAGONAL portion of the local submatrix (possibly different for
3290            each row) or PETSC_NULL, if o_nz is used to specify the nonzero
3291            structure. The size of this array is equal to the number
3292            of local rows, i.e 'm'.
3293 
3294    If the *_nnz parameter is given then the *_nz parameter is ignored
3295 
3296    The AIJ format (also called the Yale sparse matrix format or
3297    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3298    storage.  The stored row and column indices begin with zero.  See the users manual for details.
3299 
3300    The parallel matrix is partitioned such that the first m0 rows belong to
3301    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3302    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3303 
3304    The DIAGONAL portion of the local submatrix of a processor can be defined
3305    as the submatrix which is obtained by extraction the part corresponding
3306    to the rows r1-r2 and columns r1-r2 of the global matrix, where r1 is the
3307    first row that belongs to the processor, and r2 is the last row belonging
3308    to the this processor. This is a square mxm matrix. The remaining portion
3309    of the local submatrix (mxN) constitute the OFF-DIAGONAL portion.
3310 
3311    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3312 
3313    You can call MatGetInfo() to get information on how effective the preallocation was;
3314    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3315    You can also run with the option -info and look for messages with the string
3316    malloc in them to see if additional memory allocation was needed.
3317 
3318    Example usage:
3319 
3320    Consider the following 8x8 matrix with 34 non-zero values, that is
3321    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3322    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3323    as follows:
3324 
3325 .vb
3326             1  2  0  |  0  3  0  |  0  4
3327     Proc0   0  5  6  |  7  0  0  |  8  0
3328             9  0 10  | 11  0  0  | 12  0
3329     -------------------------------------
3330            13  0 14  | 15 16 17  |  0  0
3331     Proc1   0 18  0  | 19 20 21  |  0  0
3332             0  0  0  | 22 23  0  | 24  0
3333     -------------------------------------
3334     Proc2  25 26 27  |  0  0 28  | 29  0
3335            30  0  0  | 31 32 33  |  0 34
3336 .ve
3337 
3338    This can be represented as a collection of submatrices as:
3339 
3340 .vb
3341       A B C
3342       D E F
3343       G H I
3344 .ve
3345 
3346    Where the submatrices A,B,C are owned by proc0, D,E,F are
3347    owned by proc1, G,H,I are owned by proc2.
3348 
3349    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3350    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3351    The 'M','N' parameters are 8,8, and have the same values on all procs.
3352 
3353    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3354    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3355    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3356    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3357    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3358    matrix, ans [DF] as another SeqAIJ matrix.
3359 
3360    When d_nz, o_nz parameters are specified, d_nz storage elements are
3361    allocated for every row of the local diagonal submatrix, and o_nz
3362    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3363    One way to choose d_nz and o_nz is to use the max nonzerors per local
3364    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3365    In this case, the values of d_nz,o_nz are:
3366 .vb
3367      proc0 : dnz = 2, o_nz = 2
3368      proc1 : dnz = 3, o_nz = 2
3369      proc2 : dnz = 1, o_nz = 4
3370 .ve
3371    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3372    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3373    for proc3. i.e we are using 12+15+10=37 storage locations to store
3374    34 values.
3375 
3376    When d_nnz, o_nnz parameters are specified, the storage is specified
3377    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3378    In the above case the values for d_nnz,o_nnz are:
3379 .vb
3380      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3381      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3382      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3383 .ve
3384    Here the space allocated is sum of all the above values i.e 34, and
3385    hence pre-allocation is perfect.
3386 
3387    Level: intermediate
3388 
3389 .keywords: matrix, aij, compressed row, sparse, parallel
3390 
3391 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateMPIAIJ(), MatMPIAIJSetPreallocationCSR(),
3392           MPIAIJ, MatGetInfo()
3393 @*/
3394 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3395 {
3396   PetscErrorCode ierr,(*f)(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]);
3397 
3398   PetscFunctionBegin;
3399   ierr = PetscObjectQueryFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",(void (**)(void))&f);CHKERRQ(ierr);
3400   if (f) {
3401     ierr = (*f)(B,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
3402   }
3403   PetscFunctionReturn(0);
3404 }
3405 
3406 #undef __FUNCT__
3407 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3408 /*@
3409      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3410          CSR format the local rows.
3411 
3412    Collective on MPI_Comm
3413 
3414    Input Parameters:
3415 +  comm - MPI communicator
3416 .  m - number of local rows (Cannot be PETSC_DECIDE)
3417 .  n - This value should be the same as the local size used in creating the
3418        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3419        calculated if N is given) For square matrices n is almost always m.
3420 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3421 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3422 .   i - row indices
3423 .   j - column indices
3424 -   a - matrix values
3425 
3426    Output Parameter:
3427 .   mat - the matrix
3428 
3429    Level: intermediate
3430 
3431    Notes:
3432        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3433      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3434      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3435 
3436        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3437 
3438        The format which is used for the sparse matrix input, is equivalent to a
3439     row-major ordering.. i.e for the following matrix, the input data expected is
3440     as shown:
3441 
3442         1 0 0
3443         2 0 3     P0
3444        -------
3445         4 5 6     P1
3446 
3447      Process0 [P0]: rows_owned=[0,1]
3448         i =  {0,1,3}  [size = nrow+1  = 2+1]
3449         j =  {0,0,2}  [size = nz = 6]
3450         v =  {1,2,3}  [size = nz = 6]
3451 
3452      Process1 [P1]: rows_owned=[2]
3453         i =  {0,3}    [size = nrow+1  = 1+1]
3454         j =  {0,1,2}  [size = nz = 6]
3455         v =  {4,5,6}  [size = nz = 6]
3456 
3457 .keywords: matrix, aij, compressed row, sparse, parallel
3458 
3459 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3460           MPIAIJ, MatCreateMPIAIJ(), MatCreateMPIAIJWithSplitArrays()
3461 @*/
3462 PetscErrorCode PETSCMAT_DLLEXPORT MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
3463 {
3464   PetscErrorCode ierr;
3465 
3466  PetscFunctionBegin;
3467   if (i[0]) {
3468     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
3469   }
3470   if (m < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
3471   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
3472   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
3473   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
3474   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
3475   PetscFunctionReturn(0);
3476 }
3477 
3478 #undef __FUNCT__
3479 #define __FUNCT__ "MatCreateMPIAIJ"
3480 /*@C
3481    MatCreateMPIAIJ - Creates a sparse parallel matrix in AIJ format
3482    (the default parallel PETSc format).  For good matrix assembly performance
3483    the user should preallocate the matrix storage by setting the parameters
3484    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3485    performance can be increased by more than a factor of 50.
3486 
3487    Collective on MPI_Comm
3488 
3489    Input Parameters:
3490 +  comm - MPI communicator
3491 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
3492            This value should be the same as the local size used in creating the
3493            y vector for the matrix-vector product y = Ax.
3494 .  n - This value should be the same as the local size used in creating the
3495        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3496        calculated if N is given) For square matrices n is almost always m.
3497 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3498 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3499 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3500            (same value is used for all local rows)
3501 .  d_nnz - array containing the number of nonzeros in the various rows of the
3502            DIAGONAL portion of the local submatrix (possibly different for each row)
3503            or PETSC_NULL, if d_nz is used to specify the nonzero structure.
3504            The size of this array is equal to the number of local rows, i.e 'm'.
3505            You must leave room for the diagonal entry even if it is zero.
3506 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3507            submatrix (same value is used for all local rows).
3508 -  o_nnz - array containing the number of nonzeros in the various rows of the
3509            OFF-DIAGONAL portion of the local submatrix (possibly different for
3510            each row) or PETSC_NULL, if o_nz is used to specify the nonzero
3511            structure. The size of this array is equal to the number
3512            of local rows, i.e 'm'.
3513 
3514    Output Parameter:
3515 .  A - the matrix
3516 
3517    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
3518    MatXXXXSetPreallocation() paradgm instead of this routine directly.
3519    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
3520 
3521    Notes:
3522    If the *_nnz parameter is given then the *_nz parameter is ignored
3523 
3524    m,n,M,N parameters specify the size of the matrix, and its partitioning across
3525    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
3526    storage requirements for this matrix.
3527 
3528    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
3529    processor than it must be used on all processors that share the object for
3530    that argument.
3531 
3532    The user MUST specify either the local or global matrix dimensions
3533    (possibly both).
3534 
3535    The parallel matrix is partitioned across processors such that the
3536    first m0 rows belong to process 0, the next m1 rows belong to
3537    process 1, the next m2 rows belong to process 2 etc.. where
3538    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
3539    values corresponding to [m x N] submatrix.
3540 
3541    The columns are logically partitioned with the n0 columns belonging
3542    to 0th partition, the next n1 columns belonging to the next
3543    partition etc.. where n0,n1,n2... are the the input parameter 'n'.
3544 
3545    The DIAGONAL portion of the local submatrix on any given processor
3546    is the submatrix corresponding to the rows and columns m,n
3547    corresponding to the given processor. i.e diagonal matrix on
3548    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
3549    etc. The remaining portion of the local submatrix [m x (N-n)]
3550    constitute the OFF-DIAGONAL portion. The example below better
3551    illustrates this concept.
3552 
3553    For a square global matrix we define each processor's diagonal portion
3554    to be its local rows and the corresponding columns (a square submatrix);
3555    each processor's off-diagonal portion encompasses the remainder of the
3556    local matrix (a rectangular submatrix).
3557 
3558    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3559 
3560    When calling this routine with a single process communicator, a matrix of
3561    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
3562    type of communicator, use the construction mechanism:
3563      MatCreate(...,&A); MatSetType(A,MPIAIJ); MatMPIAIJSetPreallocation(A,...);
3564 
3565    By default, this format uses inodes (identical nodes) when possible.
3566    We search for consecutive rows with the same nonzero structure, thereby
3567    reusing matrix information to achieve increased efficiency.
3568 
3569    Options Database Keys:
3570 +  -mat_no_inode  - Do not use inodes
3571 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3572 -  -mat_aij_oneindex - Internally use indexing starting at 1
3573         rather than 0.  Note that when calling MatSetValues(),
3574         the user still MUST index entries starting at 0!
3575 
3576 
3577    Example usage:
3578 
3579    Consider the following 8x8 matrix with 34 non-zero values, that is
3580    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3581    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3582    as follows:
3583 
3584 .vb
3585             1  2  0  |  0  3  0  |  0  4
3586     Proc0   0  5  6  |  7  0  0  |  8  0
3587             9  0 10  | 11  0  0  | 12  0
3588     -------------------------------------
3589            13  0 14  | 15 16 17  |  0  0
3590     Proc1   0 18  0  | 19 20 21  |  0  0
3591             0  0  0  | 22 23  0  | 24  0
3592     -------------------------------------
3593     Proc2  25 26 27  |  0  0 28  | 29  0
3594            30  0  0  | 31 32 33  |  0 34
3595 .ve
3596 
3597    This can be represented as a collection of submatrices as:
3598 
3599 .vb
3600       A B C
3601       D E F
3602       G H I
3603 .ve
3604 
3605    Where the submatrices A,B,C are owned by proc0, D,E,F are
3606    owned by proc1, G,H,I are owned by proc2.
3607 
3608    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3609    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3610    The 'M','N' parameters are 8,8, and have the same values on all procs.
3611 
3612    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3613    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3614    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3615    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3616    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3617    matrix, ans [DF] as another SeqAIJ matrix.
3618 
3619    When d_nz, o_nz parameters are specified, d_nz storage elements are
3620    allocated for every row of the local diagonal submatrix, and o_nz
3621    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3622    One way to choose d_nz and o_nz is to use the max nonzerors per local
3623    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3624    In this case, the values of d_nz,o_nz are:
3625 .vb
3626      proc0 : dnz = 2, o_nz = 2
3627      proc1 : dnz = 3, o_nz = 2
3628      proc2 : dnz = 1, o_nz = 4
3629 .ve
3630    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3631    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3632    for proc3. i.e we are using 12+15+10=37 storage locations to store
3633    34 values.
3634 
3635    When d_nnz, o_nnz parameters are specified, the storage is specified
3636    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3637    In the above case the values for d_nnz,o_nnz are:
3638 .vb
3639      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3640      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3641      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3642 .ve
3643    Here the space allocated is sum of all the above values i.e 34, and
3644    hence pre-allocation is perfect.
3645 
3646    Level: intermediate
3647 
3648 .keywords: matrix, aij, compressed row, sparse, parallel
3649 
3650 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3651           MPIAIJ, MatCreateMPIAIJWithArrays()
3652 @*/
3653 PetscErrorCode PETSCMAT_DLLEXPORT MatCreateMPIAIJ(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)
3654 {
3655   PetscErrorCode ierr;
3656   PetscMPIInt    size;
3657 
3658   PetscFunctionBegin;
3659   ierr = MatCreate(comm,A);CHKERRQ(ierr);
3660   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
3661   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3662   if (size > 1) {
3663     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
3664     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
3665   } else {
3666     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
3667     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
3668   }
3669   PetscFunctionReturn(0);
3670 }
3671 
3672 #undef __FUNCT__
3673 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
3674 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,PetscInt *colmap[])
3675 {
3676   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
3677 
3678   PetscFunctionBegin;
3679   *Ad     = a->A;
3680   *Ao     = a->B;
3681   *colmap = a->garray;
3682   PetscFunctionReturn(0);
3683 }
3684 
3685 #undef __FUNCT__
3686 #define __FUNCT__ "MatSetColoring_MPIAIJ"
3687 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
3688 {
3689   PetscErrorCode ierr;
3690   PetscInt       i;
3691   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3692 
3693   PetscFunctionBegin;
3694   if (coloring->ctype == IS_COLORING_GLOBAL) {
3695     ISColoringValue *allcolors,*colors;
3696     ISColoring      ocoloring;
3697 
3698     /* set coloring for diagonal portion */
3699     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
3700 
3701     /* set coloring for off-diagonal portion */
3702     ierr = ISAllGatherColors(((PetscObject)A)->comm,coloring->n,coloring->colors,PETSC_NULL,&allcolors);CHKERRQ(ierr);
3703     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
3704     for (i=0; i<a->B->cmap->n; i++) {
3705       colors[i] = allcolors[a->garray[i]];
3706     }
3707     ierr = PetscFree(allcolors);CHKERRQ(ierr);
3708     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
3709     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
3710     ierr = ISColoringDestroy(ocoloring);CHKERRQ(ierr);
3711   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
3712     ISColoringValue *colors;
3713     PetscInt        *larray;
3714     ISColoring      ocoloring;
3715 
3716     /* set coloring for diagonal portion */
3717     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
3718     for (i=0; i<a->A->cmap->n; i++) {
3719       larray[i] = i + A->cmap->rstart;
3720     }
3721     ierr = ISGlobalToLocalMappingApply(A->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,PETSC_NULL,larray);CHKERRQ(ierr);
3722     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
3723     for (i=0; i<a->A->cmap->n; i++) {
3724       colors[i] = coloring->colors[larray[i]];
3725     }
3726     ierr = PetscFree(larray);CHKERRQ(ierr);
3727     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
3728     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
3729     ierr = ISColoringDestroy(ocoloring);CHKERRQ(ierr);
3730 
3731     /* set coloring for off-diagonal portion */
3732     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
3733     ierr = ISGlobalToLocalMappingApply(A->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,PETSC_NULL,larray);CHKERRQ(ierr);
3734     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
3735     for (i=0; i<a->B->cmap->n; i++) {
3736       colors[i] = coloring->colors[larray[i]];
3737     }
3738     ierr = PetscFree(larray);CHKERRQ(ierr);
3739     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
3740     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
3741     ierr = ISColoringDestroy(ocoloring);CHKERRQ(ierr);
3742   } else {
3743     SETERRQ1(PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
3744   }
3745 
3746   PetscFunctionReturn(0);
3747 }
3748 
3749 #if defined(PETSC_HAVE_ADIC)
3750 #undef __FUNCT__
3751 #define __FUNCT__ "MatSetValuesAdic_MPIAIJ"
3752 PetscErrorCode MatSetValuesAdic_MPIAIJ(Mat A,void *advalues)
3753 {
3754   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3755   PetscErrorCode ierr;
3756 
3757   PetscFunctionBegin;
3758   ierr = MatSetValuesAdic_SeqAIJ(a->A,advalues);CHKERRQ(ierr);
3759   ierr = MatSetValuesAdic_SeqAIJ(a->B,advalues);CHKERRQ(ierr);
3760   PetscFunctionReturn(0);
3761 }
3762 #endif
3763 
3764 #undef __FUNCT__
3765 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
3766 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
3767 {
3768   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3769   PetscErrorCode ierr;
3770 
3771   PetscFunctionBegin;
3772   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
3773   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
3774   PetscFunctionReturn(0);
3775 }
3776 
3777 #undef __FUNCT__
3778 #define __FUNCT__ "MatMerge"
3779 /*@
3780       MatMerge - Creates a single large PETSc matrix by concatinating sequential
3781                  matrices from each processor
3782 
3783     Collective on MPI_Comm
3784 
3785    Input Parameters:
3786 +    comm - the communicators the parallel matrix will live on
3787 .    inmat - the input sequential matrices
3788 .    n - number of local columns (or PETSC_DECIDE)
3789 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
3790 
3791    Output Parameter:
3792 .    outmat - the parallel matrix generated
3793 
3794     Level: advanced
3795 
3796    Notes: The number of columns of the matrix in EACH processor MUST be the same.
3797 
3798 @*/
3799 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
3800 {
3801   PetscErrorCode ierr;
3802   PetscInt       m,N,i,rstart,nnz,Ii,*dnz,*onz;
3803   PetscInt       *indx;
3804   PetscScalar    *values;
3805 
3806   PetscFunctionBegin;
3807   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
3808   if (scall == MAT_INITIAL_MATRIX){
3809     /* count nonzeros in each row, for diagonal and off diagonal portion of matrix */
3810     if (n == PETSC_DECIDE){
3811       ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
3812     }
3813     ierr = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3814     rstart -= m;
3815 
3816     ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
3817     for (i=0;i<m;i++) {
3818       ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,PETSC_NULL);CHKERRQ(ierr);
3819       ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
3820       ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,PETSC_NULL);CHKERRQ(ierr);
3821     }
3822     /* This routine will ONLY return MPIAIJ type matrix */
3823     ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
3824     ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
3825     ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
3826     ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
3827     ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
3828 
3829   } else if (scall == MAT_REUSE_MATRIX){
3830     ierr = MatGetOwnershipRange(*outmat,&rstart,PETSC_NULL);CHKERRQ(ierr);
3831   } else {
3832     SETERRQ1(PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
3833   }
3834 
3835   for (i=0;i<m;i++) {
3836     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
3837     Ii    = i + rstart;
3838     ierr = MatSetValues(*outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
3839     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
3840   }
3841   ierr = MatDestroy(inmat);CHKERRQ(ierr);
3842   ierr = MatAssemblyBegin(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3843   ierr = MatAssemblyEnd(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3844 
3845   PetscFunctionReturn(0);
3846 }
3847 
3848 #undef __FUNCT__
3849 #define __FUNCT__ "MatFileSplit"
3850 PetscErrorCode MatFileSplit(Mat A,char *outfile)
3851 {
3852   PetscErrorCode    ierr;
3853   PetscMPIInt       rank;
3854   PetscInt          m,N,i,rstart,nnz;
3855   size_t            len;
3856   const PetscInt    *indx;
3857   PetscViewer       out;
3858   char              *name;
3859   Mat               B;
3860   const PetscScalar *values;
3861 
3862   PetscFunctionBegin;
3863   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
3864   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
3865   /* Should this be the type of the diagonal block of A? */
3866   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
3867   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
3868   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
3869   ierr = MatSeqAIJSetPreallocation(B,0,PETSC_NULL);CHKERRQ(ierr);
3870   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
3871   for (i=0;i<m;i++) {
3872     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
3873     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
3874     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
3875   }
3876   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3877   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3878 
3879   ierr = MPI_Comm_rank(((PetscObject)A)->comm,&rank);CHKERRQ(ierr);
3880   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
3881   ierr = PetscMalloc((len+5)*sizeof(char),&name);CHKERRQ(ierr);
3882   sprintf(name,"%s.%d",outfile,rank);
3883   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
3884   ierr = PetscFree(name);
3885   ierr = MatView(B,out);CHKERRQ(ierr);
3886   ierr = PetscViewerDestroy(out);CHKERRQ(ierr);
3887   ierr = MatDestroy(B);CHKERRQ(ierr);
3888   PetscFunctionReturn(0);
3889 }
3890 
3891 EXTERN PetscErrorCode MatDestroy_MPIAIJ(Mat);
3892 #undef __FUNCT__
3893 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
3894 PetscErrorCode PETSCMAT_DLLEXPORT MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
3895 {
3896   PetscErrorCode       ierr;
3897   Mat_Merge_SeqsToMPI  *merge;
3898   PetscContainer       container;
3899 
3900   PetscFunctionBegin;
3901   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject *)&container);CHKERRQ(ierr);
3902   if (container) {
3903     ierr = PetscContainerGetPointer(container,(void **)&merge);CHKERRQ(ierr);
3904     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
3905     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
3906     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
3907     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
3908     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
3909     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
3910     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
3911     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
3912     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
3913     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
3914     ierr = PetscFree(merge->rowmap.range);CHKERRQ(ierr);
3915 
3916     ierr = PetscContainerDestroy(container);CHKERRQ(ierr);
3917     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
3918   }
3919   ierr = PetscFree(merge);CHKERRQ(ierr);
3920 
3921   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
3922   PetscFunctionReturn(0);
3923 }
3924 
3925 #include "../src/mat/utils/freespace.h"
3926 #include "petscbt.h"
3927 
3928 #undef __FUNCT__
3929 #define __FUNCT__ "MatMerge_SeqsToMPINumeric"
3930 /*@C
3931       MatMerge_SeqsToMPI - Creates a MPIAIJ matrix by adding sequential
3932                  matrices from each processor
3933 
3934     Collective on MPI_Comm
3935 
3936    Input Parameters:
3937 +    comm - the communicators the parallel matrix will live on
3938 .    seqmat - the input sequential matrices
3939 .    m - number of local rows (or PETSC_DECIDE)
3940 .    n - number of local columns (or PETSC_DECIDE)
3941 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
3942 
3943    Output Parameter:
3944 .    mpimat - the parallel matrix generated
3945 
3946     Level: advanced
3947 
3948    Notes:
3949      The dimensions of the sequential matrix in each processor MUST be the same.
3950      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
3951      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
3952 @*/
3953 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge_SeqsToMPINumeric(Mat seqmat,Mat mpimat)
3954 {
3955   PetscErrorCode       ierr;
3956   MPI_Comm             comm=((PetscObject)mpimat)->comm;
3957   Mat_SeqAIJ           *a=(Mat_SeqAIJ*)seqmat->data;
3958   PetscMPIInt          size,rank,taga,*len_s;
3959   PetscInt             N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj=a->j;
3960   PetscInt             proc,m;
3961   PetscInt             **buf_ri,**buf_rj;
3962   PetscInt             k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
3963   PetscInt             nrows,**buf_ri_k,**nextrow,**nextai;
3964   MPI_Request          *s_waits,*r_waits;
3965   MPI_Status           *status;
3966   MatScalar            *aa=a->a;
3967   MatScalar            **abuf_r,*ba_i;
3968   Mat_Merge_SeqsToMPI  *merge;
3969   PetscContainer       container;
3970 
3971   PetscFunctionBegin;
3972   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
3973 
3974   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3975   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3976 
3977   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject *)&container);CHKERRQ(ierr);
3978   if (container) {
3979     ierr  = PetscContainerGetPointer(container,(void **)&merge);CHKERRQ(ierr);
3980   }
3981   bi     = merge->bi;
3982   bj     = merge->bj;
3983   buf_ri = merge->buf_ri;
3984   buf_rj = merge->buf_rj;
3985 
3986   ierr   = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
3987   owners = merge->rowmap.range;
3988   len_s  = merge->len_s;
3989 
3990   /* send and recv matrix values */
3991   /*-----------------------------*/
3992   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
3993   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
3994 
3995   ierr = PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&s_waits);CHKERRQ(ierr);
3996   for (proc=0,k=0; proc<size; proc++){
3997     if (!len_s[proc]) continue;
3998     i = owners[proc];
3999     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4000     k++;
4001   }
4002 
4003   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4004   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4005   ierr = PetscFree(status);CHKERRQ(ierr);
4006 
4007   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4008   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4009 
4010   /* insert mat values of mpimat */
4011   /*----------------------------*/
4012   ierr = PetscMalloc(N*sizeof(PetscScalar),&ba_i);CHKERRQ(ierr);
4013   ierr = PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);CHKERRQ(ierr);
4014   nextrow = buf_ri_k + merge->nrecv;
4015   nextai  = nextrow + merge->nrecv;
4016 
4017   for (k=0; k<merge->nrecv; k++){
4018     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4019     nrows = *(buf_ri_k[k]);
4020     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4021     nextai[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
4022   }
4023 
4024   /* set values of ba */
4025   m = merge->rowmap.n;
4026   for (i=0; i<m; i++) {
4027     arow = owners[rank] + i;
4028     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4029     bnzi = bi[i+1] - bi[i];
4030     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4031 
4032     /* add local non-zero vals of this proc's seqmat into ba */
4033     anzi = ai[arow+1] - ai[arow];
4034     aj   = a->j + ai[arow];
4035     aa   = a->a + ai[arow];
4036     nextaj = 0;
4037     for (j=0; nextaj<anzi; j++){
4038       if (*(bj_i + j) == aj[nextaj]){ /* bcol == acol */
4039         ba_i[j] += aa[nextaj++];
4040       }
4041     }
4042 
4043     /* add received vals into ba */
4044     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
4045       /* i-th row */
4046       if (i == *nextrow[k]) {
4047         anzi = *(nextai[k]+1) - *nextai[k];
4048         aj   = buf_rj[k] + *(nextai[k]);
4049         aa   = abuf_r[k] + *(nextai[k]);
4050         nextaj = 0;
4051         for (j=0; nextaj<anzi; j++){
4052           if (*(bj_i + j) == aj[nextaj]){ /* bcol == acol */
4053             ba_i[j] += aa[nextaj++];
4054           }
4055         }
4056         nextrow[k]++; nextai[k]++;
4057       }
4058     }
4059     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4060   }
4061   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4062   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4063 
4064   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4065   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4066   ierr = PetscFree(buf_ri_k);CHKERRQ(ierr);
4067   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4068   PetscFunctionReturn(0);
4069 }
4070 
4071 #undef __FUNCT__
4072 #define __FUNCT__ "MatMerge_SeqsToMPISymbolic"
4073 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge_SeqsToMPISymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4074 {
4075   PetscErrorCode       ierr;
4076   Mat                  B_mpi;
4077   Mat_SeqAIJ           *a=(Mat_SeqAIJ*)seqmat->data;
4078   PetscMPIInt          size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4079   PetscInt             **buf_rj,**buf_ri,**buf_ri_k;
4080   PetscInt             M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4081   PetscInt             len,proc,*dnz,*onz;
4082   PetscInt             k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4083   PetscInt             nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4084   MPI_Request          *si_waits,*sj_waits,*ri_waits,*rj_waits;
4085   MPI_Status           *status;
4086   PetscFreeSpaceList   free_space=PETSC_NULL,current_space=PETSC_NULL;
4087   PetscBT              lnkbt;
4088   Mat_Merge_SeqsToMPI  *merge;
4089   PetscContainer       container;
4090 
4091   PetscFunctionBegin;
4092   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4093 
4094   /* make sure it is a PETSc comm */
4095   ierr = PetscCommDuplicate(comm,&comm,PETSC_NULL);CHKERRQ(ierr);
4096   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4097   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4098 
4099   ierr = PetscNew(Mat_Merge_SeqsToMPI,&merge);CHKERRQ(ierr);
4100   ierr = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
4101 
4102   /* determine row ownership */
4103   /*---------------------------------------------------------*/
4104   ierr = PetscMapInitialize(comm,&merge->rowmap);CHKERRQ(ierr);
4105   merge->rowmap.n = m;
4106   merge->rowmap.N = M;
4107   merge->rowmap.bs = 1;
4108   ierr = PetscMapSetUp(&merge->rowmap);CHKERRQ(ierr);
4109   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&len_si);CHKERRQ(ierr);
4110   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&merge->len_s);CHKERRQ(ierr);
4111 
4112   m      = merge->rowmap.n;
4113   M      = merge->rowmap.N;
4114   owners = merge->rowmap.range;
4115 
4116   /* determine the number of messages to send, their lengths */
4117   /*---------------------------------------------------------*/
4118   len_s  = merge->len_s;
4119 
4120   len = 0;  /* length of buf_si[] */
4121   merge->nsend = 0;
4122   for (proc=0; proc<size; proc++){
4123     len_si[proc] = 0;
4124     if (proc == rank){
4125       len_s[proc] = 0;
4126     } else {
4127       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4128       len_s[proc] = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4129     }
4130     if (len_s[proc]) {
4131       merge->nsend++;
4132       nrows = 0;
4133       for (i=owners[proc]; i<owners[proc+1]; i++){
4134         if (ai[i+1] > ai[i]) nrows++;
4135       }
4136       len_si[proc] = 2*(nrows+1);
4137       len += len_si[proc];
4138     }
4139   }
4140 
4141   /* determine the number and length of messages to receive for ij-structure */
4142   /*-------------------------------------------------------------------------*/
4143   ierr = PetscGatherNumberOfMessages(comm,PETSC_NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4144   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4145 
4146   /* post the Irecv of j-structure */
4147   /*-------------------------------*/
4148   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4149   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4150 
4151   /* post the Isend of j-structure */
4152   /*--------------------------------*/
4153   ierr = PetscMalloc((2*merge->nsend+1)*sizeof(MPI_Request),&si_waits);CHKERRQ(ierr);
4154   sj_waits = si_waits + merge->nsend;
4155 
4156   for (proc=0, k=0; proc<size; proc++){
4157     if (!len_s[proc]) continue;
4158     i = owners[proc];
4159     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4160     k++;
4161   }
4162 
4163   /* receives and sends of j-structure are complete */
4164   /*------------------------------------------------*/
4165   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4166   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4167 
4168   /* send and recv i-structure */
4169   /*---------------------------*/
4170   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4171   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4172 
4173   ierr = PetscMalloc((len+1)*sizeof(PetscInt),&buf_s);CHKERRQ(ierr);
4174   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4175   for (proc=0,k=0; proc<size; proc++){
4176     if (!len_s[proc]) continue;
4177     /* form outgoing message for i-structure:
4178          buf_si[0]:                 nrows to be sent
4179                [1:nrows]:           row index (global)
4180                [nrows+1:2*nrows+1]: i-structure index
4181     */
4182     /*-------------------------------------------*/
4183     nrows = len_si[proc]/2 - 1;
4184     buf_si_i    = buf_si + nrows+1;
4185     buf_si[0]   = nrows;
4186     buf_si_i[0] = 0;
4187     nrows = 0;
4188     for (i=owners[proc]; i<owners[proc+1]; i++){
4189       anzi = ai[i+1] - ai[i];
4190       if (anzi) {
4191         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4192         buf_si[nrows+1] = i-owners[proc]; /* local row index */
4193         nrows++;
4194       }
4195     }
4196     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4197     k++;
4198     buf_si += len_si[proc];
4199   }
4200 
4201   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4202   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4203 
4204   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4205   for (i=0; i<merge->nrecv; i++){
4206     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);
4207   }
4208 
4209   ierr = PetscFree(len_si);CHKERRQ(ierr);
4210   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4211   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4212   ierr = PetscFree(si_waits);CHKERRQ(ierr);
4213   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4214   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4215   ierr = PetscFree(status);CHKERRQ(ierr);
4216 
4217   /* compute a local seq matrix in each processor */
4218   /*----------------------------------------------*/
4219   /* allocate bi array and free space for accumulating nonzero column info */
4220   ierr = PetscMalloc((m+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
4221   bi[0] = 0;
4222 
4223   /* create and initialize a linked list */
4224   nlnk = N+1;
4225   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4226 
4227   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4228   len = 0;
4229   len  = ai[owners[rank+1]] - ai[owners[rank]];
4230   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4231   current_space = free_space;
4232 
4233   /* determine symbolic info for each local row */
4234   ierr = PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);CHKERRQ(ierr);
4235   nextrow = buf_ri_k + merge->nrecv;
4236   nextai  = nextrow + merge->nrecv;
4237   for (k=0; k<merge->nrecv; k++){
4238     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4239     nrows = *buf_ri_k[k];
4240     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4241     nextai[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
4242   }
4243 
4244   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4245   len = 0;
4246   for (i=0;i<m;i++) {
4247     bnzi   = 0;
4248     /* add local non-zero cols of this proc's seqmat into lnk */
4249     arow   = owners[rank] + i;
4250     anzi   = ai[arow+1] - ai[arow];
4251     aj     = a->j + ai[arow];
4252     ierr = PetscLLAdd(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4253     bnzi += nlnk;
4254     /* add received col data into lnk */
4255     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
4256       if (i == *nextrow[k]) { /* i-th row */
4257         anzi = *(nextai[k]+1) - *nextai[k];
4258         aj   = buf_rj[k] + *nextai[k];
4259         ierr = PetscLLAdd(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4260         bnzi += nlnk;
4261         nextrow[k]++; nextai[k]++;
4262       }
4263     }
4264     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4265 
4266     /* if free space is not available, make more free space */
4267     if (current_space->local_remaining<bnzi) {
4268       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4269       nspacedouble++;
4270     }
4271     /* copy data into free space, then initialize lnk */
4272     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4273     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4274 
4275     current_space->array           += bnzi;
4276     current_space->local_used      += bnzi;
4277     current_space->local_remaining -= bnzi;
4278 
4279     bi[i+1] = bi[i] + bnzi;
4280   }
4281 
4282   ierr = PetscFree(buf_ri_k);CHKERRQ(ierr);
4283 
4284   ierr = PetscMalloc((bi[m]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
4285   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4286   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4287 
4288   /* create symbolic parallel matrix B_mpi */
4289   /*---------------------------------------*/
4290   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4291   if (n==PETSC_DECIDE) {
4292     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4293   } else {
4294     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4295   }
4296   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4297   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4298   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4299 
4300   /* B_mpi is not ready for use - assembly will be done by MatMerge_SeqsToMPINumeric() */
4301   B_mpi->assembled     = PETSC_FALSE;
4302   B_mpi->ops->destroy  = MatDestroy_MPIAIJ_SeqsToMPI;
4303   merge->bi            = bi;
4304   merge->bj            = bj;
4305   merge->buf_ri        = buf_ri;
4306   merge->buf_rj        = buf_rj;
4307   merge->coi           = PETSC_NULL;
4308   merge->coj           = PETSC_NULL;
4309   merge->owners_co     = PETSC_NULL;
4310 
4311   /* attach the supporting struct to B_mpi for reuse */
4312   ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4313   ierr = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4314   ierr = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4315   *mpimat = B_mpi;
4316 
4317   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4318   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4319   PetscFunctionReturn(0);
4320 }
4321 
4322 #undef __FUNCT__
4323 #define __FUNCT__ "MatMerge_SeqsToMPI"
4324 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge_SeqsToMPI(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4325 {
4326   PetscErrorCode   ierr;
4327 
4328   PetscFunctionBegin;
4329   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4330   if (scall == MAT_INITIAL_MATRIX){
4331     ierr = MatMerge_SeqsToMPISymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4332   }
4333   ierr = MatMerge_SeqsToMPINumeric(seqmat,*mpimat);CHKERRQ(ierr);
4334   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4335   PetscFunctionReturn(0);
4336 }
4337 
4338 #undef __FUNCT__
4339 #define __FUNCT__ "MatGetLocalMat"
4340 /*@
4341      MatGetLocalMat - Creates a SeqAIJ matrix by taking all its local rows
4342 
4343     Not Collective
4344 
4345    Input Parameters:
4346 +    A - the matrix
4347 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4348 
4349    Output Parameter:
4350 .    A_loc - the local sequential matrix generated
4351 
4352     Level: developer
4353 
4354 @*/
4355 PetscErrorCode PETSCMAT_DLLEXPORT MatGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4356 {
4357   PetscErrorCode  ierr;
4358   Mat_MPIAIJ      *mpimat=(Mat_MPIAIJ*)A->data;
4359   Mat_SeqAIJ      *mat,*a=(Mat_SeqAIJ*)(mpimat->A)->data,*b=(Mat_SeqAIJ*)(mpimat->B)->data;
4360   PetscInt        *ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,*cmap=mpimat->garray;
4361   MatScalar       *aa=a->a,*ba=b->a,*cam;
4362   PetscScalar     *ca;
4363   PetscInt        am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4364   PetscInt        *ci,*cj,col,ncols_d,ncols_o,jo;
4365 
4366   PetscFunctionBegin;
4367   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4368   if (scall == MAT_INITIAL_MATRIX){
4369     ierr = PetscMalloc((1+am)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
4370     ci[0] = 0;
4371     for (i=0; i<am; i++){
4372       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4373     }
4374     ierr = PetscMalloc((1+ci[am])*sizeof(PetscInt),&cj);CHKERRQ(ierr);
4375     ierr = PetscMalloc((1+ci[am])*sizeof(PetscScalar),&ca);CHKERRQ(ierr);
4376     k = 0;
4377     for (i=0; i<am; i++) {
4378       ncols_o = bi[i+1] - bi[i];
4379       ncols_d = ai[i+1] - ai[i];
4380       /* off-diagonal portion of A */
4381       for (jo=0; jo<ncols_o; jo++) {
4382         col = cmap[*bj];
4383         if (col >= cstart) break;
4384         cj[k]   = col; bj++;
4385         ca[k++] = *ba++;
4386       }
4387       /* diagonal portion of A */
4388       for (j=0; j<ncols_d; j++) {
4389         cj[k]   = cstart + *aj++;
4390         ca[k++] = *aa++;
4391       }
4392       /* off-diagonal portion of A */
4393       for (j=jo; j<ncols_o; j++) {
4394         cj[k]   = cmap[*bj++];
4395         ca[k++] = *ba++;
4396       }
4397     }
4398     /* put together the new matrix */
4399     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4400     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4401     /* Since these are PETSc arrays, change flags to free them as necessary. */
4402     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4403     mat->free_a  = PETSC_TRUE;
4404     mat->free_ij = PETSC_TRUE;
4405     mat->nonew   = 0;
4406   } else if (scall == MAT_REUSE_MATRIX){
4407     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4408     ci = mat->i; cj = mat->j; cam = mat->a;
4409     for (i=0; i<am; i++) {
4410       /* off-diagonal portion of A */
4411       ncols_o = bi[i+1] - bi[i];
4412       for (jo=0; jo<ncols_o; jo++) {
4413         col = cmap[*bj];
4414         if (col >= cstart) break;
4415         *cam++ = *ba++; bj++;
4416       }
4417       /* diagonal portion of A */
4418       ncols_d = ai[i+1] - ai[i];
4419       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4420       /* off-diagonal portion of A */
4421       for (j=jo; j<ncols_o; j++) {
4422         *cam++ = *ba++; bj++;
4423       }
4424     }
4425   } else {
4426     SETERRQ1(PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
4427   }
4428 
4429   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4430   PetscFunctionReturn(0);
4431 }
4432 
4433 #undef __FUNCT__
4434 #define __FUNCT__ "MatGetLocalMatCondensed"
4435 /*@C
4436      MatGetLocalMatCondensed - Creates a SeqAIJ matrix by taking all its local rows and NON-ZERO columns
4437 
4438     Not Collective
4439 
4440    Input Parameters:
4441 +    A - the matrix
4442 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4443 -    row, col - index sets of rows and columns to extract (or PETSC_NULL)
4444 
4445    Output Parameter:
4446 .    A_loc - the local sequential matrix generated
4447 
4448     Level: developer
4449 
4450 @*/
4451 PetscErrorCode PETSCMAT_DLLEXPORT MatGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
4452 {
4453   Mat_MPIAIJ        *a=(Mat_MPIAIJ*)A->data;
4454   PetscErrorCode    ierr;
4455   PetscInt          i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
4456   IS                isrowa,iscola;
4457   Mat               *aloc;
4458 
4459   PetscFunctionBegin;
4460   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4461   if (!row){
4462     start = A->rmap->rstart; end = A->rmap->rend;
4463     ierr = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
4464   } else {
4465     isrowa = *row;
4466   }
4467   if (!col){
4468     start = A->cmap->rstart;
4469     cmap  = a->garray;
4470     nzA   = a->A->cmap->n;
4471     nzB   = a->B->cmap->n;
4472     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
4473     ncols = 0;
4474     for (i=0; i<nzB; i++) {
4475       if (cmap[i] < start) idx[ncols++] = cmap[i];
4476       else break;
4477     }
4478     imark = i;
4479     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
4480     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
4481     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,&iscola);CHKERRQ(ierr);
4482     ierr = PetscFree(idx);CHKERRQ(ierr);
4483   } else {
4484     iscola = *col;
4485   }
4486   if (scall != MAT_INITIAL_MATRIX){
4487     ierr = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
4488     aloc[0] = *A_loc;
4489   }
4490   ierr = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
4491   *A_loc = aloc[0];
4492   ierr = PetscFree(aloc);CHKERRQ(ierr);
4493   if (!row){
4494     ierr = ISDestroy(isrowa);CHKERRQ(ierr);
4495   }
4496   if (!col){
4497     ierr = ISDestroy(iscola);CHKERRQ(ierr);
4498   }
4499   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4500   PetscFunctionReturn(0);
4501 }
4502 
4503 #undef __FUNCT__
4504 #define __FUNCT__ "MatGetBrowsOfAcols"
4505 /*@C
4506     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
4507 
4508     Collective on Mat
4509 
4510    Input Parameters:
4511 +    A,B - the matrices in mpiaij format
4512 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4513 -    rowb, colb - index sets of rows and columns of B to extract (or PETSC_NULL)
4514 
4515    Output Parameter:
4516 +    rowb, colb - index sets of rows and columns of B to extract
4517 .    brstart - row index of B_seq from which next B->rmap->n rows are taken from B's local rows
4518 -    B_seq - the sequential matrix generated
4519 
4520     Level: developer
4521 
4522 @*/
4523 PetscErrorCode PETSCMAT_DLLEXPORT MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,PetscInt *brstart,Mat *B_seq)
4524 {
4525   Mat_MPIAIJ        *a=(Mat_MPIAIJ*)A->data;
4526   PetscErrorCode    ierr;
4527   PetscInt          *idx,i,start,ncols,nzA,nzB,*cmap,imark;
4528   IS                isrowb,iscolb;
4529   Mat               *bseq;
4530 
4531   PetscFunctionBegin;
4532   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
4533     SETERRQ4(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);
4534   }
4535   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
4536 
4537   if (scall == MAT_INITIAL_MATRIX){
4538     start = A->cmap->rstart;
4539     cmap  = a->garray;
4540     nzA   = a->A->cmap->n;
4541     nzB   = a->B->cmap->n;
4542     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
4543     ncols = 0;
4544     for (i=0; i<nzB; i++) {  /* row < local row index */
4545       if (cmap[i] < start) idx[ncols++] = cmap[i];
4546       else break;
4547     }
4548     imark = i;
4549     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
4550     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
4551     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,&isrowb);CHKERRQ(ierr);
4552     ierr = PetscFree(idx);CHKERRQ(ierr);
4553     *brstart = imark;
4554     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
4555   } else {
4556     if (!rowb || !colb) SETERRQ(PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
4557     isrowb = *rowb; iscolb = *colb;
4558     ierr = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
4559     bseq[0] = *B_seq;
4560   }
4561   ierr = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
4562   *B_seq = bseq[0];
4563   ierr = PetscFree(bseq);CHKERRQ(ierr);
4564   if (!rowb){
4565     ierr = ISDestroy(isrowb);CHKERRQ(ierr);
4566   } else {
4567     *rowb = isrowb;
4568   }
4569   if (!colb){
4570     ierr = ISDestroy(iscolb);CHKERRQ(ierr);
4571   } else {
4572     *colb = iscolb;
4573   }
4574   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
4575   PetscFunctionReturn(0);
4576 }
4577 
4578 #undef __FUNCT__
4579 #define __FUNCT__ "MatGetBrowsOfAoCols"
4580 /*@C
4581     MatGetBrowsOfAoCols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
4582     of the OFF-DIAGONAL portion of local A
4583 
4584     Collective on Mat
4585 
4586    Input Parameters:
4587 +    A,B - the matrices in mpiaij format
4588 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4589 .    startsj - starting point in B's sending and receiving j-arrays, saved for MAT_REUSE (or PETSC_NULL)
4590 -    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or PETSC_NULL)
4591 
4592    Output Parameter:
4593 +    B_oth - the sequential matrix generated
4594 
4595     Level: developer
4596 
4597 @*/
4598 PetscErrorCode PETSCMAT_DLLEXPORT MatGetBrowsOfAoCols(Mat A,Mat B,MatReuse scall,PetscInt **startsj,MatScalar **bufa_ptr,Mat *B_oth)
4599 {
4600   VecScatter_MPI_General *gen_to,*gen_from;
4601   PetscErrorCode         ierr;
4602   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
4603   Mat_SeqAIJ             *b_oth;
4604   VecScatter             ctx=a->Mvctx;
4605   MPI_Comm               comm=((PetscObject)ctx)->comm;
4606   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
4607   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
4608   PetscScalar            *rvalues,*svalues;
4609   MatScalar              *b_otha,*bufa,*bufA;
4610   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
4611   MPI_Request            *rwaits = PETSC_NULL,*swaits = PETSC_NULL;
4612   MPI_Status             *sstatus,rstatus;
4613   PetscMPIInt            jj;
4614   PetscInt               *cols,sbs,rbs;
4615   PetscScalar            *vals;
4616 
4617   PetscFunctionBegin;
4618   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
4619     SETERRQ4(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);
4620   }
4621   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
4622   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4623 
4624   gen_to   = (VecScatter_MPI_General*)ctx->todata;
4625   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
4626   rvalues  = gen_from->values; /* holds the length of receiving row */
4627   svalues  = gen_to->values;   /* holds the length of sending row */
4628   nrecvs   = gen_from->n;
4629   nsends   = gen_to->n;
4630 
4631   ierr = PetscMalloc2(nrecvs,MPI_Request,&rwaits,nsends,MPI_Request,&swaits);CHKERRQ(ierr);
4632   srow     = gen_to->indices;   /* local row index to be sent */
4633   sstarts  = gen_to->starts;
4634   sprocs   = gen_to->procs;
4635   sstatus  = gen_to->sstatus;
4636   sbs      = gen_to->bs;
4637   rstarts  = gen_from->starts;
4638   rprocs   = gen_from->procs;
4639   rbs      = gen_from->bs;
4640 
4641   if (!startsj || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
4642   if (scall == MAT_INITIAL_MATRIX){
4643     /* i-array */
4644     /*---------*/
4645     /*  post receives */
4646     for (i=0; i<nrecvs; i++){
4647       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
4648       nrows = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
4649       ierr = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4650     }
4651 
4652     /* pack the outgoing message */
4653     ierr = PetscMalloc((nsends+nrecvs+3)*sizeof(PetscInt),&sstartsj);CHKERRQ(ierr);
4654     rstartsj = sstartsj + nsends +1;
4655     sstartsj[0] = 0;  rstartsj[0] = 0;
4656     len = 0; /* total length of j or a array to be sent */
4657     k = 0;
4658     for (i=0; i<nsends; i++){
4659       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
4660       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4661       for (j=0; j<nrows; j++) {
4662         row = srow[k] + B->rmap->range[rank]; /* global row idx */
4663         for (l=0; l<sbs; l++){
4664           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); /* rowlength */
4665           rowlen[j*sbs+l] = ncols;
4666           len += ncols;
4667           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
4668         }
4669         k++;
4670       }
4671       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4672       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
4673     }
4674     /* recvs and sends of i-array are completed */
4675     i = nrecvs;
4676     while (i--) {
4677       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4678     }
4679     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4680 
4681     /* allocate buffers for sending j and a arrays */
4682     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&bufj);CHKERRQ(ierr);
4683     ierr = PetscMalloc((len+1)*sizeof(PetscScalar),&bufa);CHKERRQ(ierr);
4684 
4685     /* create i-array of B_oth */
4686     ierr = PetscMalloc((aBn+2)*sizeof(PetscInt),&b_othi);CHKERRQ(ierr);
4687     b_othi[0] = 0;
4688     len = 0; /* total length of j or a array to be received */
4689     k = 0;
4690     for (i=0; i<nrecvs; i++){
4691       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
4692       nrows = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
4693       for (j=0; j<nrows; j++) {
4694         b_othi[k+1] = b_othi[k] + rowlen[j];
4695         len += rowlen[j]; k++;
4696       }
4697       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
4698     }
4699 
4700     /* allocate space for j and a arrrays of B_oth */
4701     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(PetscInt),&b_othj);CHKERRQ(ierr);
4702     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(MatScalar),&b_otha);CHKERRQ(ierr);
4703 
4704     /* j-array */
4705     /*---------*/
4706     /*  post receives of j-array */
4707     for (i=0; i<nrecvs; i++){
4708       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
4709       ierr = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4710     }
4711 
4712     /* pack the outgoing message j-array */
4713     k = 0;
4714     for (i=0; i<nsends; i++){
4715       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4716       bufJ = bufj+sstartsj[i];
4717       for (j=0; j<nrows; j++) {
4718         row  = srow[k++] + B->rmap->range[rank]; /* global row idx */
4719         for (ll=0; ll<sbs; ll++){
4720           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,PETSC_NULL);CHKERRQ(ierr);
4721           for (l=0; l<ncols; l++){
4722             *bufJ++ = cols[l];
4723           }
4724           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,PETSC_NULL);CHKERRQ(ierr);
4725         }
4726       }
4727       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4728     }
4729 
4730     /* recvs and sends of j-array are completed */
4731     i = nrecvs;
4732     while (i--) {
4733       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4734     }
4735     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4736   } else if (scall == MAT_REUSE_MATRIX){
4737     sstartsj = *startsj;
4738     rstartsj = sstartsj + nsends +1;
4739     bufa     = *bufa_ptr;
4740     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
4741     b_otha   = b_oth->a;
4742   } else {
4743     SETERRQ(PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
4744   }
4745 
4746   /* a-array */
4747   /*---------*/
4748   /*  post receives of a-array */
4749   for (i=0; i<nrecvs; i++){
4750     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
4751     ierr = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4752   }
4753 
4754   /* pack the outgoing message a-array */
4755   k = 0;
4756   for (i=0; i<nsends; i++){
4757     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4758     bufA = bufa+sstartsj[i];
4759     for (j=0; j<nrows; j++) {
4760       row  = srow[k++] + B->rmap->range[rank]; /* global row idx */
4761       for (ll=0; ll<sbs; ll++){
4762         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,PETSC_NULL,&vals);CHKERRQ(ierr);
4763         for (l=0; l<ncols; l++){
4764           *bufA++ = vals[l];
4765         }
4766         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,PETSC_NULL,&vals);CHKERRQ(ierr);
4767       }
4768     }
4769     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4770   }
4771   /* recvs and sends of a-array are completed */
4772   i = nrecvs;
4773   while (i--) {
4774     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4775   }
4776   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4777   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
4778 
4779   if (scall == MAT_INITIAL_MATRIX){
4780     /* put together the new matrix */
4781     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
4782 
4783     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4784     /* Since these are PETSc arrays, change flags to free them as necessary. */
4785     b_oth          = (Mat_SeqAIJ *)(*B_oth)->data;
4786     b_oth->free_a  = PETSC_TRUE;
4787     b_oth->free_ij = PETSC_TRUE;
4788     b_oth->nonew   = 0;
4789 
4790     ierr = PetscFree(bufj);CHKERRQ(ierr);
4791     if (!startsj || !bufa_ptr){
4792       ierr = PetscFree(sstartsj);CHKERRQ(ierr);
4793       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
4794     } else {
4795       *startsj  = sstartsj;
4796       *bufa_ptr = bufa;
4797     }
4798   }
4799   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
4800   PetscFunctionReturn(0);
4801 }
4802 
4803 #undef __FUNCT__
4804 #define __FUNCT__ "MatGetCommunicationStructs"
4805 /*@C
4806   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
4807 
4808   Not Collective
4809 
4810   Input Parameters:
4811 . A - The matrix in mpiaij format
4812 
4813   Output Parameter:
4814 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
4815 . colmap - A map from global column index to local index into lvec
4816 - multScatter - A scatter from the argument of a matrix-vector product to lvec
4817 
4818   Level: developer
4819 
4820 @*/
4821 #if defined (PETSC_USE_CTABLE)
4822 PetscErrorCode PETSCMAT_DLLEXPORT MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
4823 #else
4824 PetscErrorCode PETSCMAT_DLLEXPORT MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
4825 #endif
4826 {
4827   Mat_MPIAIJ *a;
4828 
4829   PetscFunctionBegin;
4830   PetscValidHeaderSpecific(A, MAT_COOKIE, 1);
4831   PetscValidPointer(lvec, 2)
4832   PetscValidPointer(colmap, 3)
4833   PetscValidPointer(multScatter, 4)
4834   a = (Mat_MPIAIJ *) A->data;
4835   if (lvec) *lvec = a->lvec;
4836   if (colmap) *colmap = a->colmap;
4837   if (multScatter) *multScatter = a->Mvctx;
4838   PetscFunctionReturn(0);
4839 }
4840 
4841 EXTERN_C_BEGIN
4842 extern PetscErrorCode PETSCMAT_DLLEXPORT MatConvert_MPIAIJ_MPICRL(Mat,const MatType,MatReuse,Mat*);
4843 extern PetscErrorCode PETSCMAT_DLLEXPORT MatConvert_MPIAIJ_MPICSRPERM(Mat,const MatType,MatReuse,Mat*);
4844 EXTERN_C_END
4845 
4846 #include "../src/mat/impls/dense/mpi/mpidense.h"
4847 
4848 #undef __FUNCT__
4849 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
4850 /*
4851     Computes (B'*A')' since computing B*A directly is untenable
4852 
4853                n                       p                          p
4854         (              )       (              )         (                  )
4855       m (      A       )  *  n (       B      )   =   m (         C        )
4856         (              )       (              )         (                  )
4857 
4858 */
4859 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
4860 {
4861   PetscErrorCode     ierr;
4862   Mat                At,Bt,Ct;
4863 
4864   PetscFunctionBegin;
4865   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
4866   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
4867   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
4868   ierr = MatDestroy(At);CHKERRQ(ierr);
4869   ierr = MatDestroy(Bt);CHKERRQ(ierr);
4870   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
4871   ierr = MatDestroy(Ct);CHKERRQ(ierr);
4872   PetscFunctionReturn(0);
4873 }
4874 
4875 #undef __FUNCT__
4876 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
4877 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
4878 {
4879   PetscErrorCode ierr;
4880   PetscInt       m=A->rmap->n,n=B->cmap->n;
4881   Mat            Cmat;
4882 
4883   PetscFunctionBegin;
4884   if (A->cmap->n != B->rmap->n) SETERRQ2(PETSC_ERR_ARG_SIZ,"A->cmap->n %d != B->rmap->n %d\n",A->cmap->n,B->rmap->n);
4885   ierr = MatCreate(((PetscObject)A)->comm,&Cmat);CHKERRQ(ierr);
4886   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4887   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
4888   ierr = MatMPIDenseSetPreallocation(Cmat,PETSC_NULL);CHKERRQ(ierr);
4889   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4890   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4891   *C   = Cmat;
4892   PetscFunctionReturn(0);
4893 }
4894 
4895 /* ----------------------------------------------------------------*/
4896 #undef __FUNCT__
4897 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
4898 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
4899 {
4900   PetscErrorCode ierr;
4901 
4902   PetscFunctionBegin;
4903   if (scall == MAT_INITIAL_MATRIX){
4904     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
4905   }
4906   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
4907   PetscFunctionReturn(0);
4908 }
4909 
4910 EXTERN_C_BEGIN
4911 #if defined(PETSC_HAVE_MUMPS)
4912 extern PetscErrorCode MatGetFactor_mpiaij_mumps(Mat,MatFactorType,Mat*);
4913 #endif
4914 #if defined(PETSC_HAVE_PASTIX)
4915 extern PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
4916 #endif
4917 #if defined(PETSC_HAVE_SUPERLU_DIST)
4918 extern PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
4919 #endif
4920 #if defined(PETSC_HAVE_SPOOLES)
4921 extern PetscErrorCode MatGetFactor_mpiaij_spooles(Mat,MatFactorType,Mat*);
4922 #endif
4923 EXTERN_C_END
4924 
4925 /*MC
4926    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
4927 
4928    Options Database Keys:
4929 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
4930 
4931   Level: beginner
4932 
4933 .seealso: MatCreateMPIAIJ()
4934 M*/
4935 
4936 EXTERN_C_BEGIN
4937 #undef __FUNCT__
4938 #define __FUNCT__ "MatCreate_MPIAIJ"
4939 PetscErrorCode PETSCMAT_DLLEXPORT MatCreate_MPIAIJ(Mat B)
4940 {
4941   Mat_MPIAIJ     *b;
4942   PetscErrorCode ierr;
4943   PetscMPIInt    size;
4944 
4945   PetscFunctionBegin;
4946   ierr = MPI_Comm_size(((PetscObject)B)->comm,&size);CHKERRQ(ierr);
4947 
4948   ierr            = PetscNewLog(B,Mat_MPIAIJ,&b);CHKERRQ(ierr);
4949   B->data         = (void*)b;
4950   ierr            = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
4951   B->rmap->bs      = 1;
4952   B->assembled    = PETSC_FALSE;
4953   B->mapping      = 0;
4954 
4955   B->insertmode      = NOT_SET_VALUES;
4956   b->size            = size;
4957   ierr = MPI_Comm_rank(((PetscObject)B)->comm,&b->rank);CHKERRQ(ierr);
4958 
4959   /* build cache for off array entries formed */
4960   ierr = MatStashCreate_Private(((PetscObject)B)->comm,1,&B->stash);CHKERRQ(ierr);
4961   b->donotstash  = PETSC_FALSE;
4962   b->colmap      = 0;
4963   b->garray      = 0;
4964   b->roworiented = PETSC_TRUE;
4965 
4966   /* stuff used for matrix vector multiply */
4967   b->lvec      = PETSC_NULL;
4968   b->Mvctx     = PETSC_NULL;
4969 
4970   /* stuff for MatGetRow() */
4971   b->rowindices   = 0;
4972   b->rowvalues    = 0;
4973   b->getrowactive = PETSC_FALSE;
4974 
4975 #if defined(PETSC_HAVE_SPOOLES)
4976   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_spooles_C",
4977                                      "MatGetFactor_mpiaij_spooles",
4978                                      MatGetFactor_mpiaij_spooles);CHKERRQ(ierr);
4979 #endif
4980 #if defined(PETSC_HAVE_MUMPS)
4981   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_mumps_C",
4982                                      "MatGetFactor_mpiaij_mumps",
4983                                      MatGetFactor_mpiaij_mumps);CHKERRQ(ierr);
4984 #endif
4985 #if defined(PETSC_HAVE_PASTIX)
4986   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_pastix_C",
4987 					   "MatGetFactor_mpiaij_pastix",
4988 					   MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
4989 #endif
4990 #if defined(PETSC_HAVE_SUPERLU_DIST)
4991   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_superlu_dist_C",
4992                                      "MatGetFactor_mpiaij_superlu_dist",
4993                                      MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
4994 #endif
4995   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatStoreValues_C",
4996                                      "MatStoreValues_MPIAIJ",
4997                                      MatStoreValues_MPIAIJ);CHKERRQ(ierr);
4998   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatRetrieveValues_C",
4999                                      "MatRetrieveValues_MPIAIJ",
5000                                      MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5001   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetDiagonalBlock_C",
5002 				     "MatGetDiagonalBlock_MPIAIJ",
5003                                      MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5004   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatIsTranspose_C",
5005 				     "MatIsTranspose_MPIAIJ",
5006 				     MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5007   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMPIAIJSetPreallocation_C",
5008 				     "MatMPIAIJSetPreallocation_MPIAIJ",
5009 				     MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5010   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",
5011 				     "MatMPIAIJSetPreallocationCSR_MPIAIJ",
5012 				     MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5013   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatDiagonalScaleLocal_C",
5014 				     "MatDiagonalScaleLocal_MPIAIJ",
5015 				     MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5016   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpicsrperm_C",
5017                                      "MatConvert_MPIAIJ_MPICSRPERM",
5018                                       MatConvert_MPIAIJ_MPICSRPERM);CHKERRQ(ierr);
5019   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpicrl_C",
5020                                      "MatConvert_MPIAIJ_MPICRL",
5021                                       MatConvert_MPIAIJ_MPICRL);CHKERRQ(ierr);
5022   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",
5023                                      "MatMatMult_MPIDense_MPIAIJ",
5024                                       MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5025   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",
5026                                      "MatMatMultSymbolic_MPIDense_MPIAIJ",
5027                                       MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5028   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",
5029                                      "MatMatMultNumeric_MPIDense_MPIAIJ",
5030                                       MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5031   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5032   PetscFunctionReturn(0);
5033 }
5034 EXTERN_C_END
5035 
5036 #undef __FUNCT__
5037 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5038 /*@
5039      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5040          and "off-diagonal" part of the matrix in CSR format.
5041 
5042    Collective on MPI_Comm
5043 
5044    Input Parameters:
5045 +  comm - MPI communicator
5046 .  m - number of local rows (Cannot be PETSC_DECIDE)
5047 .  n - This value should be the same as the local size used in creating the
5048        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5049        calculated if N is given) For square matrices n is almost always m.
5050 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5051 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5052 .   i - row indices for "diagonal" portion of matrix
5053 .   j - column indices
5054 .   a - matrix values
5055 .   oi - row indices for "off-diagonal" portion of matrix
5056 .   oj - column indices
5057 -   oa - matrix values
5058 
5059    Output Parameter:
5060 .   mat - the matrix
5061 
5062    Level: advanced
5063 
5064    Notes:
5065        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc.
5066 
5067        The i and j indices are 0 based
5068 
5069        See MatCreateMPIAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5070 
5071 
5072 .keywords: matrix, aij, compressed row, sparse, parallel
5073 
5074 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5075           MPIAIJ, MatCreateMPIAIJ(), MatCreateMPIAIJWithArrays()
5076 @*/
5077 PetscErrorCode PETSCMAT_DLLEXPORT MatCreateMPIAIJWithSplitArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt i[],PetscInt j[],PetscScalar a[],
5078 								PetscInt oi[], PetscInt oj[],PetscScalar oa[],Mat *mat)
5079 {
5080   PetscErrorCode ierr;
5081   Mat_MPIAIJ     *maij;
5082 
5083  PetscFunctionBegin;
5084   if (m < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5085   if (i[0]) {
5086     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5087   }
5088   if (oi[0]) {
5089     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5090   }
5091   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5092   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5093   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5094   maij = (Mat_MPIAIJ*) (*mat)->data;
5095   maij->donotstash     = PETSC_TRUE;
5096   (*mat)->preallocated = PETSC_TRUE;
5097 
5098   ierr = PetscMapSetBlockSize((*mat)->rmap,1);CHKERRQ(ierr);
5099   ierr = PetscMapSetBlockSize((*mat)->cmap,1);CHKERRQ(ierr);
5100   ierr = PetscMapSetUp((*mat)->rmap);CHKERRQ(ierr);
5101   ierr = PetscMapSetUp((*mat)->cmap);CHKERRQ(ierr);
5102 
5103   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5104   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5105 
5106   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5107   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5108   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5109   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5110 
5111   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5112   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5113   PetscFunctionReturn(0);
5114 }
5115 
5116 /*
5117     Special version for direct calls from Fortran
5118 */
5119 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5120 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5121 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5122 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5123 #endif
5124 
5125 /* Change these macros so can be used in void function */
5126 #undef CHKERRQ
5127 #define CHKERRQ(ierr) CHKERRABORT(((PetscObject)mat)->comm,ierr)
5128 #undef SETERRQ2
5129 #define SETERRQ2(ierr,b,c,d) CHKERRABORT(((PetscObject)mat)->comm,ierr)
5130 #undef SETERRQ
5131 #define SETERRQ(ierr,b) CHKERRABORT(((PetscObject)mat)->comm,ierr)
5132 
5133 EXTERN_C_BEGIN
5134 #undef __FUNCT__
5135 #define __FUNCT__ "matsetvaluesmpiaij_"
5136 void PETSC_STDCALL matsetvaluesmpiaij_(Mat *mmat,PetscInt *mm,const PetscInt im[],PetscInt *mn,const PetscInt in[],const PetscScalar v[],InsertMode *maddv,PetscErrorCode *_ierr)
5137 {
5138   Mat             mat = *mmat;
5139   PetscInt        m = *mm, n = *mn;
5140   InsertMode      addv = *maddv;
5141   Mat_MPIAIJ      *aij = (Mat_MPIAIJ*)mat->data;
5142   PetscScalar     value;
5143   PetscErrorCode  ierr;
5144 
5145   ierr = MatPreallocated(mat);CHKERRQ(ierr);
5146   if (mat->insertmode == NOT_SET_VALUES) {
5147     mat->insertmode = addv;
5148   }
5149 #if defined(PETSC_USE_DEBUG)
5150   else if (mat->insertmode != addv) {
5151     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5152   }
5153 #endif
5154   {
5155   PetscInt        i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
5156   PetscInt        cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5157   PetscTruth      roworiented = aij->roworiented;
5158 
5159   /* Some Variables required in the macro */
5160   Mat             A = aij->A;
5161   Mat_SeqAIJ      *a = (Mat_SeqAIJ*)A->data;
5162   PetscInt        *aimax = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5163   MatScalar       *aa = a->a;
5164   PetscTruth      ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES))?PETSC_TRUE:PETSC_FALSE);
5165   Mat             B = aij->B;
5166   Mat_SeqAIJ      *b = (Mat_SeqAIJ*)B->data;
5167   PetscInt        *bimax = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5168   MatScalar       *ba = b->a;
5169 
5170   PetscInt        *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5171   PetscInt        nonew = a->nonew;
5172   MatScalar       *ap1,*ap2;
5173 
5174   PetscFunctionBegin;
5175   for (i=0; i<m; i++) {
5176     if (im[i] < 0) continue;
5177 #if defined(PETSC_USE_DEBUG)
5178     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
5179 #endif
5180     if (im[i] >= rstart && im[i] < rend) {
5181       row      = im[i] - rstart;
5182       lastcol1 = -1;
5183       rp1      = aj + ai[row];
5184       ap1      = aa + ai[row];
5185       rmax1    = aimax[row];
5186       nrow1    = ailen[row];
5187       low1     = 0;
5188       high1    = nrow1;
5189       lastcol2 = -1;
5190       rp2      = bj + bi[row];
5191       ap2      = ba + bi[row];
5192       rmax2    = bimax[row];
5193       nrow2    = bilen[row];
5194       low2     = 0;
5195       high2    = nrow2;
5196 
5197       for (j=0; j<n; j++) {
5198         if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
5199         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5200         if (in[j] >= cstart && in[j] < cend){
5201           col = in[j] - cstart;
5202           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5203         } else if (in[j] < 0) continue;
5204 #if defined(PETSC_USE_DEBUG)
5205         else if (in[j] >= mat->cmap->N) {SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);}
5206 #endif
5207         else {
5208           if (mat->was_assembled) {
5209             if (!aij->colmap) {
5210               ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5211             }
5212 #if defined (PETSC_USE_CTABLE)
5213             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5214 	    col--;
5215 #else
5216             col = aij->colmap[in[j]] - 1;
5217 #endif
5218             if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5219               ierr = DisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5220               col =  in[j];
5221               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5222               B = aij->B;
5223               b = (Mat_SeqAIJ*)B->data;
5224               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5225               rp2      = bj + bi[row];
5226               ap2      = ba + bi[row];
5227               rmax2    = bimax[row];
5228               nrow2    = bilen[row];
5229               low2     = 0;
5230               high2    = nrow2;
5231               bm       = aij->B->rmap->n;
5232               ba = b->a;
5233             }
5234           } else col = in[j];
5235           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
5236         }
5237       }
5238     } else {
5239       if (!aij->donotstash) {
5240         if (roworiented) {
5241           if (ignorezeroentries && v[i*n] == 0.0) continue;
5242           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n);CHKERRQ(ierr);
5243         } else {
5244           if (ignorezeroentries && v[i] == 0.0) continue;
5245           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m);CHKERRQ(ierr);
5246         }
5247       }
5248     }
5249   }}
5250   PetscFunctionReturnVoid();
5251 }
5252 EXTERN_C_END
5253 
5254