xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 78102f6c55fb0c40f4da559a448bd6b14eec00b1)
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) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"ASCII matrix output not allowed for matrices with more than 512 rows, use binary format instead");
1114 
1115     ierr = MatCreate(((PetscObject)mat)->comm,&A);CHKERRQ(ierr);
1116     if (!rank) {
1117       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1118     } else {
1119       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1120     }
1121     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1122     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1123     ierr = MatMPIAIJSetPreallocation(A,0,PETSC_NULL,0,PETSC_NULL);CHKERRQ(ierr);
1124     ierr = PetscLogObjectParent(mat,A);CHKERRQ(ierr);
1125 
1126     /* copy over the A part */
1127     Aloc = (Mat_SeqAIJ*)aij->A->data;
1128     m = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1129     row = mat->rmap->rstart;
1130     for (i=0; i<ai[m]; i++) {aj[i] += mat->cmap->rstart ;}
1131     for (i=0; i<m; i++) {
1132       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1133       row++; a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1134     }
1135     aj = Aloc->j;
1136     for (i=0; i<ai[m]; i++) {aj[i] -= mat->cmap->rstart;}
1137 
1138     /* copy over the B part */
1139     Aloc = (Mat_SeqAIJ*)aij->B->data;
1140     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1141     row  = mat->rmap->rstart;
1142     ierr = PetscMalloc((ai[m]+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
1143     ct   = cols;
1144     for (i=0; i<ai[m]; i++) {cols[i] = aij->garray[aj[i]];}
1145     for (i=0; i<m; i++) {
1146       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1147       row++; a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1148     }
1149     ierr = PetscFree(ct);CHKERRQ(ierr);
1150     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1151     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1152     /*
1153        Everyone has to call to draw the matrix since the graphics waits are
1154        synchronized across all processors that share the PetscDraw object
1155     */
1156     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
1157     if (!rank) {
1158       ierr = PetscObjectSetName((PetscObject)((Mat_MPIAIJ*)(A->data))->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1159       ierr = MatView(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1160     }
1161     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
1162     ierr = MatDestroy(A);CHKERRQ(ierr);
1163   }
1164   PetscFunctionReturn(0);
1165 }
1166 
1167 #undef __FUNCT__
1168 #define __FUNCT__ "MatView_MPIAIJ"
1169 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1170 {
1171   PetscErrorCode ierr;
1172   PetscTruth     iascii,isdraw,issocket,isbinary;
1173 
1174   PetscFunctionBegin;
1175   ierr  = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
1176   ierr  = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_DRAW,&isdraw);CHKERRQ(ierr);
1177   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_BINARY,&isbinary);CHKERRQ(ierr);
1178   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_SOCKET,&issocket);CHKERRQ(ierr);
1179   if (iascii || isdraw || isbinary || issocket) {
1180     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1181   } else {
1182     SETERRQ1(PETSC_ERR_SUP,"Viewer type %s not supported by MPIAIJ matrices",((PetscObject)viewer)->type_name);
1183   }
1184   PetscFunctionReturn(0);
1185 }
1186 
1187 #undef __FUNCT__
1188 #define __FUNCT__ "MatRelax_MPIAIJ"
1189 PetscErrorCode MatRelax_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1190 {
1191   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1192   PetscErrorCode ierr;
1193   Vec            bb1;
1194 
1195   PetscFunctionBegin;
1196   ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1197 
1198   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP){
1199     if (flag & SOR_ZERO_INITIAL_GUESS) {
1200       ierr = (*mat->A->ops->relax)(mat->A,bb,omega,flag,fshift,lits,lits,xx);CHKERRQ(ierr);
1201       its--;
1202     }
1203 
1204     while (its--) {
1205       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1206       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1207 
1208       /* update rhs: bb1 = bb - B*x */
1209       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1210       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1211 
1212       /* local sweep */
1213       ierr = (*mat->A->ops->relax)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,lits,xx);CHKERRQ(ierr);
1214     }
1215   } else if (flag & SOR_LOCAL_FORWARD_SWEEP){
1216     if (flag & SOR_ZERO_INITIAL_GUESS) {
1217       ierr = (*mat->A->ops->relax)(mat->A,bb,omega,flag,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1218       its--;
1219     }
1220     while (its--) {
1221       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1222       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1223 
1224       /* update rhs: bb1 = bb - B*x */
1225       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1226       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1227 
1228       /* local sweep */
1229       ierr = (*mat->A->ops->relax)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1230     }
1231   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP){
1232     if (flag & SOR_ZERO_INITIAL_GUESS) {
1233       ierr = (*mat->A->ops->relax)(mat->A,bb,omega,flag,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1234       its--;
1235     }
1236     while (its--) {
1237       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1238       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1239 
1240       /* update rhs: bb1 = bb - B*x */
1241       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1242       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1243 
1244       /* local sweep */
1245       ierr = (*mat->A->ops->relax)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,PETSC_NULL,xx);CHKERRQ(ierr);
1246     }
1247   } else {
1248     SETERRQ(PETSC_ERR_SUP,"Parallel SOR not supported");
1249   }
1250 
1251   ierr = VecDestroy(bb1);CHKERRQ(ierr);
1252   PetscFunctionReturn(0);
1253 }
1254 
1255 #undef __FUNCT__
1256 #define __FUNCT__ "MatPermute_MPIAIJ"
1257 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1258 {
1259   MPI_Comm       comm,pcomm;
1260   PetscInt       first,local_size,nrows;
1261   const PetscInt *rows;
1262   int            ntids;
1263   IS             crowp,growp,irowp,lrowp,lcolp,icolp;
1264   PetscErrorCode ierr;
1265 
1266   PetscFunctionBegin;
1267   ierr = PetscObjectGetComm((PetscObject)A,&comm); CHKERRQ(ierr);
1268   /* make a collective version of 'rowp' */
1269   ierr = PetscObjectGetComm((PetscObject)rowp,&pcomm); CHKERRQ(ierr);
1270   if (pcomm==comm) {
1271     crowp = rowp;
1272   } else {
1273     ierr = ISGetSize(rowp,&nrows); CHKERRQ(ierr);
1274     ierr = ISGetIndices(rowp,&rows); CHKERRQ(ierr);
1275     ierr = ISCreateGeneral(comm,nrows,rows,&crowp); CHKERRQ(ierr);
1276     ierr = ISRestoreIndices(rowp,&rows); CHKERRQ(ierr);
1277   }
1278   /* collect the global row permutation and invert it */
1279   ierr = ISAllGather(crowp,&growp); CHKERRQ(ierr);
1280   ierr = ISSetPermutation(growp); CHKERRQ(ierr);
1281   if (pcomm!=comm) {
1282     ierr = ISDestroy(crowp); CHKERRQ(ierr);
1283   }
1284   ierr = ISInvertPermutation(growp,PETSC_DECIDE,&irowp);CHKERRQ(ierr);
1285   /* get the local target indices */
1286   ierr = MatGetOwnershipRange(A,&first,PETSC_NULL); CHKERRQ(ierr);
1287   ierr = MatGetLocalSize(A,&local_size,PETSC_NULL); CHKERRQ(ierr);
1288   ierr = ISGetIndices(irowp,&rows); CHKERRQ(ierr);
1289   ierr = ISCreateGeneral(MPI_COMM_SELF,local_size,rows+first,&lrowp); CHKERRQ(ierr);
1290   ierr = ISRestoreIndices(irowp,&rows); CHKERRQ(ierr);
1291   ierr = ISDestroy(irowp); CHKERRQ(ierr);
1292   /* the column permutation is so much easier;
1293      make a local version of 'colp' and invert it */
1294   ierr = PetscObjectGetComm((PetscObject)colp,&pcomm); CHKERRQ(ierr);
1295   ierr = MPI_Comm_size(pcomm,&ntids); CHKERRQ(ierr);
1296   if (ntids==1) {
1297     lcolp = colp;
1298   } else {
1299     ierr = ISGetSize(colp,&nrows); CHKERRQ(ierr);
1300     ierr = ISGetIndices(colp,&rows); CHKERRQ(ierr);
1301     ierr = ISCreateGeneral(MPI_COMM_SELF,nrows,rows,&lcolp); CHKERRQ(ierr);
1302   }
1303   ierr = ISInvertPermutation(lcolp,PETSC_DECIDE,&icolp); CHKERRQ(ierr);
1304   ierr = ISSetPermutation(lcolp); CHKERRQ(ierr);
1305   if (ntids>1) {
1306     ierr = ISRestoreIndices(colp,&rows); CHKERRQ(ierr);
1307     ierr = ISDestroy(lcolp); CHKERRQ(ierr);
1308   }
1309   /* now we just get the submatrix */
1310   ierr = MatGetSubMatrix(A,lrowp,icolp,local_size,MAT_INITIAL_MATRIX,B); CHKERRQ(ierr);
1311   /* clean up */
1312   ierr = ISDestroy(lrowp); CHKERRQ(ierr);
1313   ierr = ISDestroy(icolp); CHKERRQ(ierr);
1314   PetscFunctionReturn(0);
1315 }
1316 
1317 #undef __FUNCT__
1318 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1319 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1320 {
1321   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1322   Mat            A = mat->A,B = mat->B;
1323   PetscErrorCode ierr;
1324   PetscReal      isend[5],irecv[5];
1325 
1326   PetscFunctionBegin;
1327   info->block_size     = 1.0;
1328   ierr = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1329   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1330   isend[3] = info->memory;  isend[4] = info->mallocs;
1331   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1332   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1333   isend[3] += info->memory;  isend[4] += info->mallocs;
1334   if (flag == MAT_LOCAL) {
1335     info->nz_used      = isend[0];
1336     info->nz_allocated = isend[1];
1337     info->nz_unneeded  = isend[2];
1338     info->memory       = isend[3];
1339     info->mallocs      = isend[4];
1340   } else if (flag == MAT_GLOBAL_MAX) {
1341     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPI_MAX,((PetscObject)matin)->comm);CHKERRQ(ierr);
1342     info->nz_used      = irecv[0];
1343     info->nz_allocated = irecv[1];
1344     info->nz_unneeded  = irecv[2];
1345     info->memory       = irecv[3];
1346     info->mallocs      = irecv[4];
1347   } else if (flag == MAT_GLOBAL_SUM) {
1348     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPI_SUM,((PetscObject)matin)->comm);CHKERRQ(ierr);
1349     info->nz_used      = irecv[0];
1350     info->nz_allocated = irecv[1];
1351     info->nz_unneeded  = irecv[2];
1352     info->memory       = irecv[3];
1353     info->mallocs      = irecv[4];
1354   }
1355   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1356   info->fill_ratio_needed = 0;
1357   info->factor_mallocs    = 0;
1358 
1359   PetscFunctionReturn(0);
1360 }
1361 
1362 #undef __FUNCT__
1363 #define __FUNCT__ "MatSetOption_MPIAIJ"
1364 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscTruth flg)
1365 {
1366   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1367   PetscErrorCode ierr;
1368 
1369   PetscFunctionBegin;
1370   switch (op) {
1371   case MAT_NEW_NONZERO_LOCATIONS:
1372   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1373   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1374   case MAT_KEEP_ZEROED_ROWS:
1375   case MAT_NEW_NONZERO_LOCATION_ERR:
1376   case MAT_USE_INODES:
1377   case MAT_IGNORE_ZERO_ENTRIES:
1378     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1379     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1380     break;
1381   case MAT_ROW_ORIENTED:
1382     a->roworiented = flg;
1383     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1384     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1385     break;
1386   case MAT_NEW_DIAGONALS:
1387     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1388     break;
1389   case MAT_IGNORE_OFF_PROC_ENTRIES:
1390     a->donotstash = PETSC_TRUE;
1391     break;
1392   case MAT_SYMMETRIC:
1393     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1394     break;
1395   case MAT_STRUCTURALLY_SYMMETRIC:
1396   case MAT_HERMITIAN:
1397   case MAT_SYMMETRY_ETERNAL:
1398     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1399     break;
1400   default:
1401     SETERRQ1(PETSC_ERR_SUP,"unknown option %d",op);
1402   }
1403   PetscFunctionReturn(0);
1404 }
1405 
1406 #undef __FUNCT__
1407 #define __FUNCT__ "MatGetRow_MPIAIJ"
1408 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1409 {
1410   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1411   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1412   PetscErrorCode ierr;
1413   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1414   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1415   PetscInt       *cmap,*idx_p;
1416 
1417   PetscFunctionBegin;
1418   if (mat->getrowactive) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Already active");
1419   mat->getrowactive = PETSC_TRUE;
1420 
1421   if (!mat->rowvalues && (idx || v)) {
1422     /*
1423         allocate enough space to hold information from the longest row.
1424     */
1425     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1426     PetscInt     max = 1,tmp;
1427     for (i=0; i<matin->rmap->n; i++) {
1428       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1429       if (max < tmp) { max = tmp; }
1430     }
1431     ierr = PetscMalloc(max*(sizeof(PetscInt)+sizeof(PetscScalar)),&mat->rowvalues);CHKERRQ(ierr);
1432     mat->rowindices = (PetscInt*)(mat->rowvalues + max);
1433   }
1434 
1435   if (row < rstart || row >= rend) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"Only local rows")
1436   lrow = row - rstart;
1437 
1438   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1439   if (!v)   {pvA = 0; pvB = 0;}
1440   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1441   ierr = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1442   ierr = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1443   nztot = nzA + nzB;
1444 
1445   cmap  = mat->garray;
1446   if (v  || idx) {
1447     if (nztot) {
1448       /* Sort by increasing column numbers, assuming A and B already sorted */
1449       PetscInt imark = -1;
1450       if (v) {
1451         *v = v_p = mat->rowvalues;
1452         for (i=0; i<nzB; i++) {
1453           if (cmap[cworkB[i]] < cstart)   v_p[i] = vworkB[i];
1454           else break;
1455         }
1456         imark = i;
1457         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1458         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1459       }
1460       if (idx) {
1461         *idx = idx_p = mat->rowindices;
1462         if (imark > -1) {
1463           for (i=0; i<imark; i++) {
1464             idx_p[i] = cmap[cworkB[i]];
1465           }
1466         } else {
1467           for (i=0; i<nzB; i++) {
1468             if (cmap[cworkB[i]] < cstart)   idx_p[i] = cmap[cworkB[i]];
1469             else break;
1470           }
1471           imark = i;
1472         }
1473         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1474         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1475       }
1476     } else {
1477       if (idx) *idx = 0;
1478       if (v)   *v   = 0;
1479     }
1480   }
1481   *nz = nztot;
1482   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1483   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1484   PetscFunctionReturn(0);
1485 }
1486 
1487 #undef __FUNCT__
1488 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1489 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1490 {
1491   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1492 
1493   PetscFunctionBegin;
1494   if (!aij->getrowactive) {
1495     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1496   }
1497   aij->getrowactive = PETSC_FALSE;
1498   PetscFunctionReturn(0);
1499 }
1500 
1501 #undef __FUNCT__
1502 #define __FUNCT__ "MatNorm_MPIAIJ"
1503 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1504 {
1505   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1506   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1507   PetscErrorCode ierr;
1508   PetscInt       i,j,cstart = mat->cmap->rstart;
1509   PetscReal      sum = 0.0;
1510   MatScalar      *v;
1511 
1512   PetscFunctionBegin;
1513   if (aij->size == 1) {
1514     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1515   } else {
1516     if (type == NORM_FROBENIUS) {
1517       v = amat->a;
1518       for (i=0; i<amat->nz; i++) {
1519 #if defined(PETSC_USE_COMPLEX)
1520         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1521 #else
1522         sum += (*v)*(*v); v++;
1523 #endif
1524       }
1525       v = bmat->a;
1526       for (i=0; i<bmat->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       ierr = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPI_SUM,((PetscObject)mat)->comm);CHKERRQ(ierr);
1534       *norm = sqrt(*norm);
1535     } else if (type == NORM_1) { /* max column norm */
1536       PetscReal *tmp,*tmp2;
1537       PetscInt  *jj,*garray = aij->garray;
1538       ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp);CHKERRQ(ierr);
1539       ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp2);CHKERRQ(ierr);
1540       ierr = PetscMemzero(tmp,mat->cmap->N*sizeof(PetscReal));CHKERRQ(ierr);
1541       *norm = 0.0;
1542       v = amat->a; jj = amat->j;
1543       for (j=0; j<amat->nz; j++) {
1544         tmp[cstart + *jj++ ] += PetscAbsScalar(*v);  v++;
1545       }
1546       v = bmat->a; jj = bmat->j;
1547       for (j=0; j<bmat->nz; j++) {
1548         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1549       }
1550       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPI_SUM,((PetscObject)mat)->comm);CHKERRQ(ierr);
1551       for (j=0; j<mat->cmap->N; j++) {
1552         if (tmp2[j] > *norm) *norm = tmp2[j];
1553       }
1554       ierr = PetscFree(tmp);CHKERRQ(ierr);
1555       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1556     } else if (type == NORM_INFINITY) { /* max row norm */
1557       PetscReal ntemp = 0.0;
1558       for (j=0; j<aij->A->rmap->n; j++) {
1559         v = amat->a + amat->i[j];
1560         sum = 0.0;
1561         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1562           sum += PetscAbsScalar(*v); v++;
1563         }
1564         v = bmat->a + bmat->i[j];
1565         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1566           sum += PetscAbsScalar(*v); v++;
1567         }
1568         if (sum > ntemp) ntemp = sum;
1569       }
1570       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPI_MAX,((PetscObject)mat)->comm);CHKERRQ(ierr);
1571     } else {
1572       SETERRQ(PETSC_ERR_SUP,"No support for two norm");
1573     }
1574   }
1575   PetscFunctionReturn(0);
1576 }
1577 
1578 #undef __FUNCT__
1579 #define __FUNCT__ "MatTranspose_MPIAIJ"
1580 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
1581 {
1582   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1583   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
1584   PetscErrorCode ierr;
1585   PetscInt       M = A->rmap->N,N = A->cmap->N,ma,na,mb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i,*d_nnz;
1586   PetscInt       cstart=A->cmap->rstart,ncol;
1587   Mat            B;
1588   MatScalar      *array;
1589 
1590   PetscFunctionBegin;
1591   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
1592 
1593   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n;
1594   ai = Aloc->i; aj = Aloc->j;
1595   bi = Bloc->i; bj = Bloc->j;
1596   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
1597     /* compute d_nnz for preallocation; o_nnz is approximated by d_nnz to avoid communication */
1598     ierr = PetscMalloc((1+na)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr);
1599     ierr = PetscMemzero(d_nnz,(1+na)*sizeof(PetscInt));CHKERRQ(ierr);
1600     for (i=0; i<ai[ma]; i++){
1601       d_nnz[aj[i]] ++;
1602       aj[i] += cstart; /* global col index to be used by MatSetValues() */
1603     }
1604 
1605     ierr = MatCreate(((PetscObject)A)->comm,&B);CHKERRQ(ierr);
1606     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
1607     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
1608     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,d_nnz);CHKERRQ(ierr);
1609     ierr = PetscFree(d_nnz);CHKERRQ(ierr);
1610   } else {
1611     B = *matout;
1612   }
1613 
1614   /* copy over the A part */
1615   array = Aloc->a;
1616   row = A->rmap->rstart;
1617   for (i=0; i<ma; i++) {
1618     ncol = ai[i+1]-ai[i];
1619     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1620     row++; array += ncol; aj += ncol;
1621   }
1622   aj = Aloc->j;
1623   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
1624 
1625   /* copy over the B part */
1626   ierr = PetscMalloc(bi[mb]*sizeof(PetscInt),&cols);CHKERRQ(ierr);
1627   ierr = PetscMemzero(cols,bi[mb]*sizeof(PetscInt));CHKERRQ(ierr);
1628   array = Bloc->a;
1629   row = A->rmap->rstart;
1630   for (i=0; i<bi[mb]; i++) {cols[i] = a->garray[bj[i]];}
1631   cols_tmp = cols;
1632   for (i=0; i<mb; i++) {
1633     ncol = bi[i+1]-bi[i];
1634     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1635     row++; array += ncol; cols_tmp += ncol;
1636   }
1637   ierr = PetscFree(cols);CHKERRQ(ierr);
1638 
1639   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1640   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1641   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
1642     *matout = B;
1643   } else {
1644     ierr = MatHeaderCopy(A,B);CHKERRQ(ierr);
1645   }
1646   PetscFunctionReturn(0);
1647 }
1648 
1649 #undef __FUNCT__
1650 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
1651 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
1652 {
1653   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1654   Mat            a = aij->A,b = aij->B;
1655   PetscErrorCode ierr;
1656   PetscInt       s1,s2,s3;
1657 
1658   PetscFunctionBegin;
1659   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
1660   if (rr) {
1661     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
1662     if (s1!=s3) SETERRQ(PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
1663     /* Overlap communication with computation. */
1664     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1665   }
1666   if (ll) {
1667     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
1668     if (s1!=s2) SETERRQ(PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
1669     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
1670   }
1671   /* scale  the diagonal block */
1672   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
1673 
1674   if (rr) {
1675     /* Do a scatter end and then right scale the off-diagonal block */
1676     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1677     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
1678   }
1679 
1680   PetscFunctionReturn(0);
1681 }
1682 
1683 #undef __FUNCT__
1684 #define __FUNCT__ "MatSetBlockSize_MPIAIJ"
1685 PetscErrorCode MatSetBlockSize_MPIAIJ(Mat A,PetscInt bs)
1686 {
1687   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1688   PetscErrorCode ierr;
1689 
1690   PetscFunctionBegin;
1691   ierr = MatSetBlockSize(a->A,bs);CHKERRQ(ierr);
1692   ierr = MatSetBlockSize(a->B,bs);CHKERRQ(ierr);
1693   PetscFunctionReturn(0);
1694 }
1695 #undef __FUNCT__
1696 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
1697 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
1698 {
1699   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
1700   PetscErrorCode ierr;
1701 
1702   PetscFunctionBegin;
1703   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
1704   PetscFunctionReturn(0);
1705 }
1706 
1707 #undef __FUNCT__
1708 #define __FUNCT__ "MatEqual_MPIAIJ"
1709 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscTruth *flag)
1710 {
1711   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
1712   Mat            a,b,c,d;
1713   PetscTruth     flg;
1714   PetscErrorCode ierr;
1715 
1716   PetscFunctionBegin;
1717   a = matA->A; b = matA->B;
1718   c = matB->A; d = matB->B;
1719 
1720   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
1721   if (flg) {
1722     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
1723   }
1724   ierr = MPI_Allreduce(&flg,flag,1,MPI_INT,MPI_LAND,((PetscObject)A)->comm);CHKERRQ(ierr);
1725   PetscFunctionReturn(0);
1726 }
1727 
1728 #undef __FUNCT__
1729 #define __FUNCT__ "MatCopy_MPIAIJ"
1730 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
1731 {
1732   PetscErrorCode ierr;
1733   Mat_MPIAIJ     *a = (Mat_MPIAIJ *)A->data;
1734   Mat_MPIAIJ     *b = (Mat_MPIAIJ *)B->data;
1735 
1736   PetscFunctionBegin;
1737   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
1738   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
1739     /* because of the column compression in the off-processor part of the matrix a->B,
1740        the number of columns in a->B and b->B may be different, hence we cannot call
1741        the MatCopy() directly on the two parts. If need be, we can provide a more
1742        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
1743        then copying the submatrices */
1744     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
1745   } else {
1746     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
1747     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
1748   }
1749   PetscFunctionReturn(0);
1750 }
1751 
1752 #undef __FUNCT__
1753 #define __FUNCT__ "MatSetUpPreallocation_MPIAIJ"
1754 PetscErrorCode MatSetUpPreallocation_MPIAIJ(Mat A)
1755 {
1756   PetscErrorCode ierr;
1757 
1758   PetscFunctionBegin;
1759   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
1760   PetscFunctionReturn(0);
1761 }
1762 
1763 #include "petscblaslapack.h"
1764 #undef __FUNCT__
1765 #define __FUNCT__ "MatAXPY_MPIAIJ"
1766 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
1767 {
1768   PetscErrorCode ierr;
1769   PetscInt       i;
1770   Mat_MPIAIJ     *xx = (Mat_MPIAIJ *)X->data,*yy = (Mat_MPIAIJ *)Y->data;
1771   PetscBLASInt   bnz,one=1;
1772   Mat_SeqAIJ     *x,*y;
1773 
1774   PetscFunctionBegin;
1775   if (str == SAME_NONZERO_PATTERN) {
1776     PetscScalar alpha = a;
1777     x = (Mat_SeqAIJ *)xx->A->data;
1778     y = (Mat_SeqAIJ *)yy->A->data;
1779     bnz = PetscBLASIntCast(x->nz);
1780     BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one);
1781     x = (Mat_SeqAIJ *)xx->B->data;
1782     y = (Mat_SeqAIJ *)yy->B->data;
1783     bnz = PetscBLASIntCast(x->nz);
1784     BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one);
1785   } else if (str == SUBSET_NONZERO_PATTERN) {
1786     ierr = MatAXPY_SeqAIJ(yy->A,a,xx->A,str);CHKERRQ(ierr);
1787 
1788     x = (Mat_SeqAIJ *)xx->B->data;
1789     y = (Mat_SeqAIJ *)yy->B->data;
1790     if (y->xtoy && y->XtoY != xx->B) {
1791       ierr = PetscFree(y->xtoy);CHKERRQ(ierr);
1792       ierr = MatDestroy(y->XtoY);CHKERRQ(ierr);
1793     }
1794     if (!y->xtoy) { /* get xtoy */
1795       ierr = MatAXPYGetxtoy_Private(xx->B->rmap->n,x->i,x->j,xx->garray,y->i,y->j,yy->garray,&y->xtoy);CHKERRQ(ierr);
1796       y->XtoY = xx->B;
1797       ierr = PetscObjectReference((PetscObject)xx->B);CHKERRQ(ierr);
1798     }
1799     for (i=0; i<x->nz; i++) y->a[y->xtoy[i]] += a*(x->a[i]);
1800   } else {
1801     ierr = MatAXPY_Basic(Y,a,X,str);CHKERRQ(ierr);
1802   }
1803   PetscFunctionReturn(0);
1804 }
1805 
1806 EXTERN PetscErrorCode PETSCMAT_DLLEXPORT MatConjugate_SeqAIJ(Mat);
1807 
1808 #undef __FUNCT__
1809 #define __FUNCT__ "MatConjugate_MPIAIJ"
1810 PetscErrorCode PETSCMAT_DLLEXPORT MatConjugate_MPIAIJ(Mat mat)
1811 {
1812 #if defined(PETSC_USE_COMPLEX)
1813   PetscErrorCode ierr;
1814   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
1815 
1816   PetscFunctionBegin;
1817   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
1818   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
1819 #else
1820   PetscFunctionBegin;
1821 #endif
1822   PetscFunctionReturn(0);
1823 }
1824 
1825 #undef __FUNCT__
1826 #define __FUNCT__ "MatRealPart_MPIAIJ"
1827 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
1828 {
1829   Mat_MPIAIJ   *a = (Mat_MPIAIJ*)A->data;
1830   PetscErrorCode ierr;
1831 
1832   PetscFunctionBegin;
1833   ierr = MatRealPart(a->A);CHKERRQ(ierr);
1834   ierr = MatRealPart(a->B);CHKERRQ(ierr);
1835   PetscFunctionReturn(0);
1836 }
1837 
1838 #undef __FUNCT__
1839 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
1840 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
1841 {
1842   Mat_MPIAIJ   *a = (Mat_MPIAIJ*)A->data;
1843   PetscErrorCode ierr;
1844 
1845   PetscFunctionBegin;
1846   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
1847   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
1848   PetscFunctionReturn(0);
1849 }
1850 
1851 #ifdef PETSC_HAVE_PBGL
1852 
1853 #include <boost/parallel/mpi/bsp_process_group.hpp>
1854 #include <boost/graph/distributed/ilu_default_graph.hpp>
1855 #include <boost/graph/distributed/ilu_0_block.hpp>
1856 #include <boost/graph/distributed/ilu_preconditioner.hpp>
1857 #include <boost/graph/distributed/petsc/interface.hpp>
1858 #include <boost/multi_array.hpp>
1859 #include <boost/parallel/distributed_property_map->hpp>
1860 
1861 #undef __FUNCT__
1862 #define __FUNCT__ "MatILUFactorSymbolic_MPIAIJ"
1863 /*
1864   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
1865 */
1866 PetscErrorCode MatILUFactorSymbolic_MPIAIJ(Mat fact,Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
1867 {
1868   namespace petsc = boost::distributed::petsc;
1869 
1870   namespace graph_dist = boost::graph::distributed;
1871   using boost::graph::distributed::ilu_default::process_group_type;
1872   using boost::graph::ilu_permuted;
1873 
1874   PetscTruth      row_identity, col_identity;
1875   PetscContainer  c;
1876   PetscInt        m, n, M, N;
1877   PetscErrorCode  ierr;
1878 
1879   PetscFunctionBegin;
1880   if (info->levels != 0) SETERRQ(PETSC_ERR_SUP,"Only levels = 0 supported for parallel ilu");
1881   ierr = ISIdentity(isrow, &row_identity);CHKERRQ(ierr);
1882   ierr = ISIdentity(iscol, &col_identity);CHKERRQ(ierr);
1883   if (!row_identity || !col_identity) {
1884     SETERRQ(PETSC_ERR_ARG_WRONG,"Row and column permutations must be identity for parallel ILU");
1885   }
1886 
1887   process_group_type pg;
1888   typedef graph_dist::ilu_default::ilu_level_graph_type  lgraph_type;
1889   lgraph_type*   lgraph_p = new lgraph_type(petsc::num_global_vertices(A), pg, petsc::matrix_distribution(A, pg));
1890   lgraph_type&   level_graph = *lgraph_p;
1891   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
1892 
1893   petsc::read_matrix(A, graph, get(boost::edge_weight, graph));
1894   ilu_permuted(level_graph);
1895 
1896   /* put together the new matrix */
1897   ierr = MatCreate(((PetscObject)A)->comm, fact);CHKERRQ(ierr);
1898   ierr = MatGetLocalSize(A, &m, &n);CHKERRQ(ierr);
1899   ierr = MatGetSize(A, &M, &N);CHKERRQ(ierr);
1900   ierr = MatSetSizes(fact, m, n, M, N);CHKERRQ(ierr);
1901   ierr = MatSetType(fact, ((PetscObject)A)->type_name);CHKERRQ(ierr);
1902   ierr = MatAssemblyBegin(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1903   ierr = MatAssemblyEnd(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1904 
1905   ierr = PetscContainerCreate(((PetscObject)A)->comm, &c);
1906   ierr = PetscContainerSetPointer(c, lgraph_p);
1907   ierr = PetscObjectCompose((PetscObject) (fact), "graph", (PetscObject) c);
1908   PetscFunctionReturn(0);
1909 }
1910 
1911 #undef __FUNCT__
1912 #define __FUNCT__ "MatLUFactorNumeric_MPIAIJ"
1913 PetscErrorCode MatLUFactorNumeric_MPIAIJ(Mat B,Mat A, const MatFactorInfo *info)
1914 {
1915   PetscFunctionBegin;
1916   PetscFunctionReturn(0);
1917 }
1918 
1919 #undef __FUNCT__
1920 #define __FUNCT__ "MatSolve_MPIAIJ"
1921 /*
1922   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
1923 */
1924 PetscErrorCode MatSolve_MPIAIJ(Mat A, Vec b, Vec x)
1925 {
1926   namespace graph_dist = boost::graph::distributed;
1927 
1928   typedef graph_dist::ilu_default::ilu_level_graph_type  lgraph_type;
1929   lgraph_type*   lgraph_p;
1930   PetscContainer c;
1931   PetscErrorCode ierr;
1932 
1933   PetscFunctionBegin;
1934   ierr = PetscObjectQuery((PetscObject) A, "graph", (PetscObject *) &c);CHKERRQ(ierr);
1935   ierr = PetscContainerGetPointer(c, (void **) &lgraph_p);CHKERRQ(ierr);
1936   ierr = VecCopy(b, x); CHKERRQ(ierr);
1937 
1938   PetscScalar* array_x;
1939   ierr = VecGetArray(x, &array_x);CHKERRQ(ierr);
1940   PetscInt sx;
1941   ierr = VecGetSize(x, &sx);CHKERRQ(ierr);
1942 
1943   PetscScalar* array_b;
1944   ierr = VecGetArray(b, &array_b);CHKERRQ(ierr);
1945   PetscInt sb;
1946   ierr = VecGetSize(b, &sb);CHKERRQ(ierr);
1947 
1948   lgraph_type&   level_graph = *lgraph_p;
1949   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
1950 
1951   typedef boost::multi_array_ref<PetscScalar, 1> array_ref_type;
1952   array_ref_type                                 ref_b(array_b, boost::extents[num_vertices(graph)]),
1953                                                  ref_x(array_x, boost::extents[num_vertices(graph)]);
1954 
1955   typedef boost::iterator_property_map<array_ref_type::iterator,
1956                                 boost::property_map<graph_dist::ilu_default::graph_type, boost::vertex_index_t>::type>  gvector_type;
1957   gvector_type                                   vector_b(ref_b.begin(), get(boost::vertex_index, graph)),
1958                                                  vector_x(ref_x.begin(), get(boost::vertex_index, graph));
1959 
1960   ilu_set_solve(*lgraph_p, vector_b, vector_x);
1961 
1962   PetscFunctionReturn(0);
1963 }
1964 #endif
1965 
1966 typedef struct { /* used by MatGetRedundantMatrix() for reusing matredundant */
1967   PetscInt       nzlocal,nsends,nrecvs;
1968   PetscMPIInt    *send_rank;
1969   PetscInt       *sbuf_nz,*sbuf_j,**rbuf_j;
1970   PetscScalar    *sbuf_a,**rbuf_a;
1971   PetscErrorCode (*MatDestroy)(Mat);
1972 } Mat_Redundant;
1973 
1974 #undef __FUNCT__
1975 #define __FUNCT__ "PetscContainerDestroy_MatRedundant"
1976 PetscErrorCode PetscContainerDestroy_MatRedundant(void *ptr)
1977 {
1978   PetscErrorCode       ierr;
1979   Mat_Redundant        *redund=(Mat_Redundant*)ptr;
1980   PetscInt             i;
1981 
1982   PetscFunctionBegin;
1983   ierr = PetscFree(redund->send_rank);CHKERRQ(ierr);
1984   ierr = PetscFree(redund->sbuf_j);CHKERRQ(ierr);
1985   ierr = PetscFree(redund->sbuf_a);CHKERRQ(ierr);
1986   for (i=0; i<redund->nrecvs; i++){
1987     ierr = PetscFree(redund->rbuf_j[i]);CHKERRQ(ierr);
1988     ierr = PetscFree(redund->rbuf_a[i]);CHKERRQ(ierr);
1989   }
1990   ierr = PetscFree3(redund->sbuf_nz,redund->rbuf_j,redund->rbuf_a);CHKERRQ(ierr);
1991   ierr = PetscFree(redund);CHKERRQ(ierr);
1992   PetscFunctionReturn(0);
1993 }
1994 
1995 #undef __FUNCT__
1996 #define __FUNCT__ "MatDestroy_MatRedundant"
1997 PetscErrorCode MatDestroy_MatRedundant(Mat A)
1998 {
1999   PetscErrorCode  ierr;
2000   PetscContainer  container;
2001   Mat_Redundant   *redund=PETSC_NULL;
2002 
2003   PetscFunctionBegin;
2004   ierr = PetscObjectQuery((PetscObject)A,"Mat_Redundant",(PetscObject *)&container);CHKERRQ(ierr);
2005   if (container) {
2006     ierr = PetscContainerGetPointer(container,(void **)&redund);CHKERRQ(ierr);
2007   } else {
2008     SETERRQ(PETSC_ERR_PLIB,"Container does not exit");
2009   }
2010   A->ops->destroy = redund->MatDestroy;
2011   ierr = PetscObjectCompose((PetscObject)A,"Mat_Redundant",0);CHKERRQ(ierr);
2012   ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
2013   ierr = PetscContainerDestroy(container);CHKERRQ(ierr);
2014   PetscFunctionReturn(0);
2015 }
2016 
2017 #undef __FUNCT__
2018 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ"
2019 PetscErrorCode MatGetRedundantMatrix_MPIAIJ(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,PetscInt mlocal_sub,MatReuse reuse,Mat *matredundant)
2020 {
2021   PetscMPIInt    rank,size;
2022   MPI_Comm       comm=((PetscObject)mat)->comm;
2023   PetscErrorCode ierr;
2024   PetscInt       nsends=0,nrecvs=0,i,rownz_max=0;
2025   PetscMPIInt    *send_rank=PETSC_NULL,*recv_rank=PETSC_NULL;
2026   PetscInt       *rowrange=mat->rmap->range;
2027   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2028   Mat            A=aij->A,B=aij->B,C=*matredundant;
2029   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data;
2030   PetscScalar    *sbuf_a;
2031   PetscInt       nzlocal=a->nz+b->nz;
2032   PetscInt       j,cstart=mat->cmap->rstart,cend=mat->cmap->rend,row,nzA,nzB,ncols,*cworkA,*cworkB;
2033   PetscInt       rstart=mat->rmap->rstart,rend=mat->rmap->rend,*bmap=aij->garray,M,N;
2034   PetscInt       *cols,ctmp,lwrite,*rptr,l,*sbuf_j;
2035   MatScalar      *aworkA,*aworkB;
2036   PetscScalar    *vals;
2037   PetscMPIInt    tag1,tag2,tag3,imdex;
2038   MPI_Request    *s_waits1=PETSC_NULL,*s_waits2=PETSC_NULL,*s_waits3=PETSC_NULL,
2039                  *r_waits1=PETSC_NULL,*r_waits2=PETSC_NULL,*r_waits3=PETSC_NULL;
2040   MPI_Status     recv_status,*send_status;
2041   PetscInt       *sbuf_nz=PETSC_NULL,*rbuf_nz=PETSC_NULL,count;
2042   PetscInt       **rbuf_j=PETSC_NULL;
2043   PetscScalar    **rbuf_a=PETSC_NULL;
2044   Mat_Redundant  *redund=PETSC_NULL;
2045   PetscContainer container;
2046 
2047   PetscFunctionBegin;
2048   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2049   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2050 
2051   if (reuse == MAT_REUSE_MATRIX) {
2052     ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
2053     if (M != N || M != mat->rmap->N) SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong global size");
2054     ierr = MatGetLocalSize(C,&M,&N);CHKERRQ(ierr);
2055     if (M != N || M != mlocal_sub) SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong local size");
2056     ierr = PetscObjectQuery((PetscObject)C,"Mat_Redundant",(PetscObject *)&container);CHKERRQ(ierr);
2057     if (container) {
2058       ierr = PetscContainerGetPointer(container,(void **)&redund);CHKERRQ(ierr);
2059     } else {
2060       SETERRQ(PETSC_ERR_PLIB,"Container does not exit");
2061     }
2062     if (nzlocal != redund->nzlocal) SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong nzlocal");
2063 
2064     nsends    = redund->nsends;
2065     nrecvs    = redund->nrecvs;
2066     send_rank = redund->send_rank; recv_rank = send_rank + size;
2067     sbuf_nz   = redund->sbuf_nz;     rbuf_nz = sbuf_nz + nsends;
2068     sbuf_j    = redund->sbuf_j;
2069     sbuf_a    = redund->sbuf_a;
2070     rbuf_j    = redund->rbuf_j;
2071     rbuf_a    = redund->rbuf_a;
2072   }
2073 
2074   if (reuse == MAT_INITIAL_MATRIX){
2075     PetscMPIInt  subrank,subsize;
2076     PetscInt     nleftover,np_subcomm;
2077     /* get the destination processors' id send_rank, nsends and nrecvs */
2078     ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
2079     ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2080     ierr = PetscMalloc((2*size+1)*sizeof(PetscMPIInt),&send_rank);
2081     recv_rank = send_rank + size;
2082     np_subcomm = size/nsubcomm;
2083     nleftover  = size - nsubcomm*np_subcomm;
2084     nsends = 0; nrecvs = 0;
2085     for (i=0; i<size; i++){ /* i=rank*/
2086       if (subrank == i/nsubcomm && rank != i){ /* my_subrank == other's subrank */
2087         send_rank[nsends] = i; nsends++;
2088         recv_rank[nrecvs++] = i;
2089       }
2090     }
2091     if (rank >= size - nleftover){/* this proc is a leftover processor */
2092       i = size-nleftover-1;
2093       j = 0;
2094       while (j < nsubcomm - nleftover){
2095         send_rank[nsends++] = i;
2096         i--; j++;
2097       }
2098     }
2099 
2100     if (nleftover && subsize == size/nsubcomm && subrank==subsize-1){ /* this proc recvs from leftover processors */
2101       for (i=0; i<nleftover; i++){
2102         recv_rank[nrecvs++] = size-nleftover+i;
2103       }
2104     }
2105 
2106     /* allocate sbuf_j, sbuf_a */
2107     i = nzlocal + rowrange[rank+1] - rowrange[rank] + 2;
2108     ierr = PetscMalloc(i*sizeof(PetscInt),&sbuf_j);CHKERRQ(ierr);
2109     ierr = PetscMalloc((nzlocal+1)*sizeof(PetscScalar),&sbuf_a);CHKERRQ(ierr);
2110   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2111 
2112   /* copy mat's local entries into the buffers */
2113   if (reuse == MAT_INITIAL_MATRIX){
2114     rownz_max = 0;
2115     rptr = sbuf_j;
2116     cols = sbuf_j + rend-rstart + 1;
2117     vals = sbuf_a;
2118     rptr[0] = 0;
2119     for (i=0; i<rend-rstart; i++){
2120       row = i + rstart;
2121       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2122       ncols  = nzA + nzB;
2123       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2124       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2125       /* load the column indices for this row into cols */
2126       lwrite = 0;
2127       for (l=0; l<nzB; l++) {
2128         if ((ctmp = bmap[cworkB[l]]) < cstart){
2129           vals[lwrite]   = aworkB[l];
2130           cols[lwrite++] = ctmp;
2131         }
2132       }
2133       for (l=0; l<nzA; l++){
2134         vals[lwrite]   = aworkA[l];
2135         cols[lwrite++] = cstart + cworkA[l];
2136       }
2137       for (l=0; l<nzB; l++) {
2138         if ((ctmp = bmap[cworkB[l]]) >= cend){
2139           vals[lwrite]   = aworkB[l];
2140           cols[lwrite++] = ctmp;
2141         }
2142       }
2143       vals += ncols;
2144       cols += ncols;
2145       rptr[i+1] = rptr[i] + ncols;
2146       if (rownz_max < ncols) rownz_max = ncols;
2147     }
2148     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);
2149   } else { /* only copy matrix values into sbuf_a */
2150     rptr = sbuf_j;
2151     vals = sbuf_a;
2152     rptr[0] = 0;
2153     for (i=0; i<rend-rstart; i++){
2154       row = i + rstart;
2155       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2156       ncols  = nzA + nzB;
2157       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2158       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2159       lwrite = 0;
2160       for (l=0; l<nzB; l++) {
2161         if ((ctmp = bmap[cworkB[l]]) < cstart) vals[lwrite++] = aworkB[l];
2162       }
2163       for (l=0; l<nzA; l++) vals[lwrite++] = aworkA[l];
2164       for (l=0; l<nzB; l++) {
2165         if ((ctmp = bmap[cworkB[l]]) >= cend) vals[lwrite++] = aworkB[l];
2166       }
2167       vals += ncols;
2168       rptr[i+1] = rptr[i] + ncols;
2169     }
2170   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2171 
2172   /* send nzlocal to others, and recv other's nzlocal */
2173   /*--------------------------------------------------*/
2174   if (reuse == MAT_INITIAL_MATRIX){
2175     ierr = PetscMalloc2(3*(nsends + nrecvs)+1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2176     s_waits2 = s_waits3 + nsends;
2177     s_waits1 = s_waits2 + nsends;
2178     r_waits1 = s_waits1 + nsends;
2179     r_waits2 = r_waits1 + nrecvs;
2180     r_waits3 = r_waits2 + nrecvs;
2181   } else {
2182     ierr = PetscMalloc2(nsends + nrecvs +1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2183     r_waits3 = s_waits3 + nsends;
2184   }
2185 
2186   ierr = PetscObjectGetNewTag((PetscObject)mat,&tag3);CHKERRQ(ierr);
2187   if (reuse == MAT_INITIAL_MATRIX){
2188     /* get new tags to keep the communication clean */
2189     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag1);CHKERRQ(ierr);
2190     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag2);CHKERRQ(ierr);
2191     ierr = PetscMalloc3(nsends+nrecvs+1,PetscInt,&sbuf_nz,nrecvs,PetscInt*,&rbuf_j,nrecvs,PetscScalar*,&rbuf_a);CHKERRQ(ierr);
2192     rbuf_nz = sbuf_nz + nsends;
2193 
2194     /* post receives of other's nzlocal */
2195     for (i=0; i<nrecvs; i++){
2196       ierr = MPI_Irecv(rbuf_nz+i,1,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,r_waits1+i);CHKERRQ(ierr);
2197     }
2198     /* send nzlocal to others */
2199     for (i=0; i<nsends; i++){
2200       sbuf_nz[i] = nzlocal;
2201       ierr = MPI_Isend(sbuf_nz+i,1,MPIU_INT,send_rank[i],tag1,comm,s_waits1+i);CHKERRQ(ierr);
2202     }
2203     /* wait on receives of nzlocal; allocate space for rbuf_j, rbuf_a */
2204     count = nrecvs;
2205     while (count) {
2206       ierr = MPI_Waitany(nrecvs,r_waits1,&imdex,&recv_status);CHKERRQ(ierr);
2207       recv_rank[imdex] = recv_status.MPI_SOURCE;
2208       /* allocate rbuf_a and rbuf_j; then post receives of rbuf_j */
2209       ierr = PetscMalloc((rbuf_nz[imdex]+1)*sizeof(PetscScalar),&rbuf_a[imdex]);CHKERRQ(ierr);
2210 
2211       i = rowrange[recv_status.MPI_SOURCE+1] - rowrange[recv_status.MPI_SOURCE]; /* number of expected mat->i */
2212       rbuf_nz[imdex] += i + 2;
2213       ierr = PetscMalloc(rbuf_nz[imdex]*sizeof(PetscInt),&rbuf_j[imdex]);CHKERRQ(ierr);
2214       ierr = MPI_Irecv(rbuf_j[imdex],rbuf_nz[imdex],MPIU_INT,recv_status.MPI_SOURCE,tag2,comm,r_waits2+imdex);CHKERRQ(ierr);
2215       count--;
2216     }
2217     /* wait on sends of nzlocal */
2218     if (nsends) {ierr = MPI_Waitall(nsends,s_waits1,send_status);CHKERRQ(ierr);}
2219     /* send mat->i,j to others, and recv from other's */
2220     /*------------------------------------------------*/
2221     for (i=0; i<nsends; i++){
2222       j = nzlocal + rowrange[rank+1] - rowrange[rank] + 1;
2223       ierr = MPI_Isend(sbuf_j,j,MPIU_INT,send_rank[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
2224     }
2225     /* wait on receives of mat->i,j */
2226     /*------------------------------*/
2227     count = nrecvs;
2228     while (count) {
2229       ierr = MPI_Waitany(nrecvs,r_waits2,&imdex,&recv_status);CHKERRQ(ierr);
2230       if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2231       count--;
2232     }
2233     /* wait on sends of mat->i,j */
2234     /*---------------------------*/
2235     if (nsends) {
2236       ierr = MPI_Waitall(nsends,s_waits2,send_status);CHKERRQ(ierr);
2237     }
2238   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2239 
2240   /* post receives, send and receive mat->a */
2241   /*----------------------------------------*/
2242   for (imdex=0; imdex<nrecvs; imdex++) {
2243     ierr = MPI_Irecv(rbuf_a[imdex],rbuf_nz[imdex],MPIU_SCALAR,recv_rank[imdex],tag3,comm,r_waits3+imdex);CHKERRQ(ierr);
2244   }
2245   for (i=0; i<nsends; i++){
2246     ierr = MPI_Isend(sbuf_a,nzlocal,MPIU_SCALAR,send_rank[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
2247   }
2248   count = nrecvs;
2249   while (count) {
2250     ierr = MPI_Waitany(nrecvs,r_waits3,&imdex,&recv_status);CHKERRQ(ierr);
2251     if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2252     count--;
2253   }
2254   if (nsends) {
2255     ierr = MPI_Waitall(nsends,s_waits3,send_status);CHKERRQ(ierr);
2256   }
2257 
2258   ierr = PetscFree2(s_waits3,send_status);CHKERRQ(ierr);
2259 
2260   /* create redundant matrix */
2261   /*-------------------------*/
2262   if (reuse == MAT_INITIAL_MATRIX){
2263     /* compute rownz_max for preallocation */
2264     for (imdex=0; imdex<nrecvs; imdex++){
2265       j = rowrange[recv_rank[imdex]+1] - rowrange[recv_rank[imdex]];
2266       rptr = rbuf_j[imdex];
2267       for (i=0; i<j; i++){
2268         ncols = rptr[i+1] - rptr[i];
2269         if (rownz_max < ncols) rownz_max = ncols;
2270       }
2271     }
2272 
2273     ierr = MatCreate(subcomm,&C);CHKERRQ(ierr);
2274     ierr = MatSetSizes(C,mlocal_sub,mlocal_sub,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
2275     ierr = MatSetFromOptions(C);CHKERRQ(ierr);
2276     ierr = MatSeqAIJSetPreallocation(C,rownz_max,PETSC_NULL);CHKERRQ(ierr);
2277     ierr = MatMPIAIJSetPreallocation(C,rownz_max,PETSC_NULL,rownz_max,PETSC_NULL);CHKERRQ(ierr);
2278   } else {
2279     C = *matredundant;
2280   }
2281 
2282   /* insert local matrix entries */
2283   rptr = sbuf_j;
2284   cols = sbuf_j + rend-rstart + 1;
2285   vals = sbuf_a;
2286   for (i=0; i<rend-rstart; i++){
2287     row   = i + rstart;
2288     ncols = rptr[i+1] - rptr[i];
2289     ierr = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2290     vals += ncols;
2291     cols += ncols;
2292   }
2293   /* insert received matrix entries */
2294   for (imdex=0; imdex<nrecvs; imdex++){
2295     rstart = rowrange[recv_rank[imdex]];
2296     rend   = rowrange[recv_rank[imdex]+1];
2297     rptr = rbuf_j[imdex];
2298     cols = rbuf_j[imdex] + rend-rstart + 1;
2299     vals = rbuf_a[imdex];
2300     for (i=0; i<rend-rstart; i++){
2301       row   = i + rstart;
2302       ncols = rptr[i+1] - rptr[i];
2303       ierr = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2304       vals += ncols;
2305       cols += ncols;
2306     }
2307   }
2308   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2309   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2310   ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
2311   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);
2312   if (reuse == MAT_INITIAL_MATRIX){
2313     PetscContainer container;
2314     *matredundant = C;
2315     /* create a supporting struct and attach it to C for reuse */
2316     ierr = PetscNewLog(C,Mat_Redundant,&redund);CHKERRQ(ierr);
2317     ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
2318     ierr = PetscContainerSetPointer(container,redund);CHKERRQ(ierr);
2319     ierr = PetscObjectCompose((PetscObject)C,"Mat_Redundant",(PetscObject)container);CHKERRQ(ierr);
2320     ierr = PetscContainerSetUserDestroy(container,PetscContainerDestroy_MatRedundant);CHKERRQ(ierr);
2321 
2322     redund->nzlocal = nzlocal;
2323     redund->nsends  = nsends;
2324     redund->nrecvs  = nrecvs;
2325     redund->send_rank = send_rank;
2326     redund->sbuf_nz = sbuf_nz;
2327     redund->sbuf_j  = sbuf_j;
2328     redund->sbuf_a  = sbuf_a;
2329     redund->rbuf_j  = rbuf_j;
2330     redund->rbuf_a  = rbuf_a;
2331 
2332     redund->MatDestroy = C->ops->destroy;
2333     C->ops->destroy    = MatDestroy_MatRedundant;
2334   }
2335   PetscFunctionReturn(0);
2336 }
2337 
2338 #undef __FUNCT__
2339 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2340 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2341 {
2342   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2343   PetscErrorCode ierr;
2344   PetscInt       i,*idxb = 0;
2345   PetscScalar    *va,*vb;
2346   Vec            vtmp;
2347 
2348   PetscFunctionBegin;
2349   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2350   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2351   if (idx) {
2352     for (i=0; i<A->rmap->n; i++) {
2353       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2354     }
2355   }
2356 
2357   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2358   if (idx) {
2359     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
2360   }
2361   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2362   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2363 
2364   for (i=0; i<A->rmap->n; i++){
2365     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2366       va[i] = vb[i];
2367       if (idx) idx[i] = a->garray[idxb[i]];
2368     }
2369   }
2370 
2371   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2372   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2373   if (idxb) {
2374     ierr = PetscFree(idxb);CHKERRQ(ierr);
2375   }
2376   ierr = VecDestroy(vtmp);CHKERRQ(ierr);
2377   PetscFunctionReturn(0);
2378 }
2379 
2380 #undef __FUNCT__
2381 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2382 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2383 {
2384   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2385   PetscErrorCode ierr;
2386   PetscInt       i,*idxb = 0;
2387   PetscScalar    *va,*vb;
2388   Vec            vtmp;
2389 
2390   PetscFunctionBegin;
2391   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2392   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2393   if (idx) {
2394     for (i=0; i<A->cmap->n; i++) {
2395       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2396     }
2397   }
2398 
2399   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2400   if (idx) {
2401     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
2402   }
2403   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2404   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2405 
2406   for (i=0; i<A->rmap->n; i++){
2407     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2408       va[i] = vb[i];
2409       if (idx) idx[i] = a->garray[idxb[i]];
2410     }
2411   }
2412 
2413   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2414   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2415   if (idxb) {
2416     ierr = PetscFree(idxb);CHKERRQ(ierr);
2417   }
2418   ierr = VecDestroy(vtmp);CHKERRQ(ierr);
2419   PetscFunctionReturn(0);
2420 }
2421 
2422 #undef __FUNCT__
2423 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2424 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2425 {
2426   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
2427   PetscInt       n      = A->rmap->n;
2428   PetscInt       cstart = A->cmap->rstart;
2429   PetscInt      *cmap   = mat->garray;
2430   PetscInt      *diagIdx, *offdiagIdx;
2431   Vec            diagV, offdiagV;
2432   PetscScalar   *a, *diagA, *offdiagA;
2433   PetscInt       r;
2434   PetscErrorCode ierr;
2435 
2436   PetscFunctionBegin;
2437   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
2438   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &diagV);CHKERRQ(ierr);
2439   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &offdiagV);CHKERRQ(ierr);
2440   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2441   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2442   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2443   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2444   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2445   for(r = 0; r < n; ++r) {
2446     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2447       a[r]   = diagA[r];
2448       idx[r] = cstart + diagIdx[r];
2449     } else {
2450       a[r]   = offdiagA[r];
2451       idx[r] = cmap[offdiagIdx[r]];
2452     }
2453   }
2454   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2455   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2456   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2457   ierr = VecDestroy(diagV);CHKERRQ(ierr);
2458   ierr = VecDestroy(offdiagV);CHKERRQ(ierr);
2459   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2460   PetscFunctionReturn(0);
2461 }
2462 
2463 #undef __FUNCT__
2464 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2465 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2466 {
2467   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
2468   PetscInt       n      = A->rmap->n;
2469   PetscInt       cstart = A->cmap->rstart;
2470   PetscInt      *cmap   = mat->garray;
2471   PetscInt      *diagIdx, *offdiagIdx;
2472   Vec            diagV, offdiagV;
2473   PetscScalar   *a, *diagA, *offdiagA;
2474   PetscInt       r;
2475   PetscErrorCode ierr;
2476 
2477   PetscFunctionBegin;
2478   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
2479   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &diagV);CHKERRQ(ierr);
2480   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &offdiagV);CHKERRQ(ierr);
2481   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2482   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2483   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2484   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2485   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2486   for(r = 0; r < n; ++r) {
2487     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2488       a[r]   = diagA[r];
2489       idx[r] = cstart + diagIdx[r];
2490     } else {
2491       a[r]   = offdiagA[r];
2492       idx[r] = cmap[offdiagIdx[r]];
2493     }
2494   }
2495   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2496   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2497   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2498   ierr = VecDestroy(diagV);CHKERRQ(ierr);
2499   ierr = VecDestroy(offdiagV);CHKERRQ(ierr);
2500   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2501   PetscFunctionReturn(0);
2502 }
2503 
2504 #undef __FUNCT__
2505 #define __FUNCT__ "MatGetSeqNonzerostructure_MPIAIJ"
2506 PetscErrorCode MatGetSeqNonzerostructure_MPIAIJ(Mat mat,Mat *newmat[])
2507 {
2508   PetscErrorCode ierr;
2509 
2510   PetscFunctionBegin;
2511   ierr = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,newmat);CHKERRQ(ierr);
2512   PetscFunctionReturn(0);
2513 }
2514 
2515 /* -------------------------------------------------------------------*/
2516 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
2517        MatGetRow_MPIAIJ,
2518        MatRestoreRow_MPIAIJ,
2519        MatMult_MPIAIJ,
2520 /* 4*/ MatMultAdd_MPIAIJ,
2521        MatMultTranspose_MPIAIJ,
2522        MatMultTransposeAdd_MPIAIJ,
2523 #ifdef PETSC_HAVE_PBGL
2524        MatSolve_MPIAIJ,
2525 #else
2526        0,
2527 #endif
2528        0,
2529        0,
2530 /*10*/ 0,
2531        0,
2532        0,
2533        MatRelax_MPIAIJ,
2534        MatTranspose_MPIAIJ,
2535 /*15*/ MatGetInfo_MPIAIJ,
2536        MatEqual_MPIAIJ,
2537        MatGetDiagonal_MPIAIJ,
2538        MatDiagonalScale_MPIAIJ,
2539        MatNorm_MPIAIJ,
2540 /*20*/ MatAssemblyBegin_MPIAIJ,
2541        MatAssemblyEnd_MPIAIJ,
2542        0,
2543        MatSetOption_MPIAIJ,
2544        MatZeroEntries_MPIAIJ,
2545 /*25*/ MatZeroRows_MPIAIJ,
2546        0,
2547 #ifdef PETSC_HAVE_PBGL
2548        0,
2549 #else
2550        0,
2551 #endif
2552        0,
2553        0,
2554 /*30*/ MatSetUpPreallocation_MPIAIJ,
2555 #ifdef PETSC_HAVE_PBGL
2556        0,
2557 #else
2558        0,
2559 #endif
2560        0,
2561        0,
2562        0,
2563 /*35*/ MatDuplicate_MPIAIJ,
2564        0,
2565        0,
2566        0,
2567        0,
2568 /*40*/ MatAXPY_MPIAIJ,
2569        MatGetSubMatrices_MPIAIJ,
2570        MatIncreaseOverlap_MPIAIJ,
2571        MatGetValues_MPIAIJ,
2572        MatCopy_MPIAIJ,
2573 /*45*/ MatGetRowMax_MPIAIJ,
2574        MatScale_MPIAIJ,
2575        0,
2576        0,
2577        0,
2578 /*50*/ MatSetBlockSize_MPIAIJ,
2579        0,
2580        0,
2581        0,
2582        0,
2583 /*55*/ MatFDColoringCreate_MPIAIJ,
2584        0,
2585        MatSetUnfactored_MPIAIJ,
2586        MatPermute_MPIAIJ,
2587        0,
2588 /*60*/ MatGetSubMatrix_MPIAIJ,
2589        MatDestroy_MPIAIJ,
2590        MatView_MPIAIJ,
2591        0,
2592        0,
2593 /*65*/ 0,
2594        0,
2595        0,
2596        0,
2597        0,
2598 /*70*/ MatGetRowMaxAbs_MPIAIJ,
2599        MatGetRowMinAbs_MPIAIJ,
2600        0,
2601        MatSetColoring_MPIAIJ,
2602 #if defined(PETSC_HAVE_ADIC)
2603        MatSetValuesAdic_MPIAIJ,
2604 #else
2605        0,
2606 #endif
2607        MatSetValuesAdifor_MPIAIJ,
2608 /*75*/ 0,
2609        0,
2610        0,
2611        0,
2612        0,
2613 /*80*/ 0,
2614        0,
2615        0,
2616 /*84*/ MatLoad_MPIAIJ,
2617        0,
2618        0,
2619        0,
2620        0,
2621        0,
2622 /*90*/ MatMatMult_MPIAIJ_MPIAIJ,
2623        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
2624        MatMatMultNumeric_MPIAIJ_MPIAIJ,
2625        MatPtAP_Basic,
2626        MatPtAPSymbolic_MPIAIJ,
2627 /*95*/ MatPtAPNumeric_MPIAIJ,
2628        0,
2629        0,
2630        0,
2631        0,
2632 /*100*/0,
2633        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
2634        MatPtAPNumeric_MPIAIJ_MPIAIJ,
2635        MatConjugate_MPIAIJ,
2636        0,
2637 /*105*/MatSetValuesRow_MPIAIJ,
2638        MatRealPart_MPIAIJ,
2639        MatImaginaryPart_MPIAIJ,
2640        0,
2641        0,
2642 /*110*/0,
2643        MatGetRedundantMatrix_MPIAIJ,
2644        MatGetRowMin_MPIAIJ,
2645        0,
2646        0,
2647 /*115*/MatGetSeqNonzerostructure_MPIAIJ};
2648 
2649 /* ----------------------------------------------------------------------------------------*/
2650 
2651 EXTERN_C_BEGIN
2652 #undef __FUNCT__
2653 #define __FUNCT__ "MatStoreValues_MPIAIJ"
2654 PetscErrorCode PETSCMAT_DLLEXPORT MatStoreValues_MPIAIJ(Mat mat)
2655 {
2656   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
2657   PetscErrorCode ierr;
2658 
2659   PetscFunctionBegin;
2660   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
2661   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
2662   PetscFunctionReturn(0);
2663 }
2664 EXTERN_C_END
2665 
2666 EXTERN_C_BEGIN
2667 #undef __FUNCT__
2668 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
2669 PetscErrorCode PETSCMAT_DLLEXPORT MatRetrieveValues_MPIAIJ(Mat mat)
2670 {
2671   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
2672   PetscErrorCode ierr;
2673 
2674   PetscFunctionBegin;
2675   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
2676   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
2677   PetscFunctionReturn(0);
2678 }
2679 EXTERN_C_END
2680 
2681 #include "petscpc.h"
2682 EXTERN_C_BEGIN
2683 #undef __FUNCT__
2684 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
2685 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
2686 {
2687   Mat_MPIAIJ     *b;
2688   PetscErrorCode ierr;
2689   PetscInt       i;
2690 
2691   PetscFunctionBegin;
2692   B->preallocated = PETSC_TRUE;
2693   if (d_nz == PETSC_DEFAULT || d_nz == PETSC_DECIDE) d_nz = 5;
2694   if (o_nz == PETSC_DEFAULT || o_nz == PETSC_DECIDE) o_nz = 2;
2695   if (d_nz < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"d_nz cannot be less than 0: value %D",d_nz);
2696   if (o_nz < 0) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"o_nz cannot be less than 0: value %D",o_nz);
2697 
2698   ierr = PetscMapSetBlockSize(B->rmap,1);CHKERRQ(ierr);
2699   ierr = PetscMapSetBlockSize(B->cmap,1);CHKERRQ(ierr);
2700   ierr = PetscMapSetUp(B->rmap);CHKERRQ(ierr);
2701   ierr = PetscMapSetUp(B->cmap);CHKERRQ(ierr);
2702   if (d_nnz) {
2703     for (i=0; i<B->rmap->n; i++) {
2704       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]);
2705     }
2706   }
2707   if (o_nnz) {
2708     for (i=0; i<B->rmap->n; i++) {
2709       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]);
2710     }
2711   }
2712   b = (Mat_MPIAIJ*)B->data;
2713 
2714   /* Explicitly create 2 MATSEQAIJ matrices. */
2715   ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
2716   ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
2717   ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
2718   ierr = PetscLogObjectParent(B,b->A);CHKERRQ(ierr);
2719   ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
2720   ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
2721   ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
2722   ierr = PetscLogObjectParent(B,b->B);CHKERRQ(ierr);
2723 
2724   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
2725   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
2726 
2727   PetscFunctionReturn(0);
2728 }
2729 EXTERN_C_END
2730 
2731 #undef __FUNCT__
2732 #define __FUNCT__ "MatDuplicate_MPIAIJ"
2733 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
2734 {
2735   Mat            mat;
2736   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
2737   PetscErrorCode ierr;
2738 
2739   PetscFunctionBegin;
2740   *newmat       = 0;
2741   ierr = MatCreate(((PetscObject)matin)->comm,&mat);CHKERRQ(ierr);
2742   ierr = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
2743   ierr = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
2744   ierr = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
2745   a    = (Mat_MPIAIJ*)mat->data;
2746 
2747   mat->factor       = matin->factor;
2748   mat->rmap->bs      = matin->rmap->bs;
2749   mat->assembled    = PETSC_TRUE;
2750   mat->insertmode   = NOT_SET_VALUES;
2751   mat->preallocated = PETSC_TRUE;
2752 
2753   a->size           = oldmat->size;
2754   a->rank           = oldmat->rank;
2755   a->donotstash     = oldmat->donotstash;
2756   a->roworiented    = oldmat->roworiented;
2757   a->rowindices     = 0;
2758   a->rowvalues      = 0;
2759   a->getrowactive   = PETSC_FALSE;
2760 
2761   ierr = PetscMapCopy(((PetscObject)mat)->comm,matin->rmap,mat->rmap);CHKERRQ(ierr);
2762   ierr = PetscMapCopy(((PetscObject)mat)->comm,matin->cmap,mat->cmap);CHKERRQ(ierr);
2763 
2764   ierr = MatStashCreate_Private(((PetscObject)matin)->comm,1,&mat->stash);CHKERRQ(ierr);
2765   if (oldmat->colmap) {
2766 #if defined (PETSC_USE_CTABLE)
2767     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
2768 #else
2769     ierr = PetscMalloc((mat->cmap->N)*sizeof(PetscInt),&a->colmap);CHKERRQ(ierr);
2770     ierr = PetscLogObjectMemory(mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2771     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
2772 #endif
2773   } else a->colmap = 0;
2774   if (oldmat->garray) {
2775     PetscInt len;
2776     len  = oldmat->B->cmap->n;
2777     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&a->garray);CHKERRQ(ierr);
2778     ierr = PetscLogObjectMemory(mat,len*sizeof(PetscInt));CHKERRQ(ierr);
2779     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
2780   } else a->garray = 0;
2781 
2782   ierr = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
2783   ierr = PetscLogObjectParent(mat,a->lvec);CHKERRQ(ierr);
2784   ierr = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
2785   ierr = PetscLogObjectParent(mat,a->Mvctx);CHKERRQ(ierr);
2786   ierr = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
2787   ierr = PetscLogObjectParent(mat,a->A);CHKERRQ(ierr);
2788   ierr = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
2789   ierr = PetscLogObjectParent(mat,a->B);CHKERRQ(ierr);
2790   ierr = PetscFListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
2791   *newmat = mat;
2792   PetscFunctionReturn(0);
2793 }
2794 
2795 #include "petscsys.h"
2796 
2797 #undef __FUNCT__
2798 #define __FUNCT__ "MatLoad_MPIAIJ"
2799 PetscErrorCode MatLoad_MPIAIJ(PetscViewer viewer, const MatType type,Mat *newmat)
2800 {
2801   Mat            A;
2802   PetscScalar    *vals,*svals;
2803   MPI_Comm       comm = ((PetscObject)viewer)->comm;
2804   MPI_Status     status;
2805   PetscErrorCode ierr;
2806   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag,mpicnt,mpimaxnz;
2807   PetscInt       i,nz,j,rstart,rend,mmax,maxnz;
2808   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
2809   PetscInt       *ourlens = PETSC_NULL,*procsnz = PETSC_NULL,*offlens = PETSC_NULL,jj,*mycols,*smycols;
2810   PetscInt       cend,cstart,n,*rowners;
2811   int            fd;
2812 
2813   PetscFunctionBegin;
2814   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2815   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2816   if (!rank) {
2817     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
2818     ierr = PetscBinaryRead(fd,(char *)header,4,PETSC_INT);CHKERRQ(ierr);
2819     if (header[0] != MAT_FILE_COOKIE) SETERRQ(PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
2820   }
2821 
2822   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
2823   M = header[1]; N = header[2];
2824   /* determine ownership of all rows */
2825   m    = M/size + ((M % size) > rank);
2826   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
2827   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
2828 
2829   /* First process needs enough room for process with most rows */
2830   if (!rank) {
2831     mmax       = rowners[1];
2832     for (i=2; i<size; i++) {
2833       mmax = PetscMax(mmax,rowners[i]);
2834     }
2835   } else mmax = m;
2836 
2837   rowners[0] = 0;
2838   for (i=2; i<=size; i++) {
2839     rowners[i] += rowners[i-1];
2840   }
2841   rstart = rowners[rank];
2842   rend   = rowners[rank+1];
2843 
2844   /* distribute row lengths to all processors */
2845   ierr    = PetscMalloc2(mmax,PetscInt,&ourlens,mmax,PetscInt,&offlens);CHKERRQ(ierr);
2846   if (!rank) {
2847     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
2848     ierr = PetscMalloc(m*sizeof(PetscInt),&rowlengths);CHKERRQ(ierr);
2849     ierr = PetscMalloc(size*sizeof(PetscInt),&procsnz);CHKERRQ(ierr);
2850     ierr = PetscMemzero(procsnz,size*sizeof(PetscInt));CHKERRQ(ierr);
2851     for (j=0; j<m; j++) {
2852       procsnz[0] += ourlens[j];
2853     }
2854     for (i=1; i<size; i++) {
2855       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
2856       /* calculate the number of nonzeros on each processor */
2857       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
2858         procsnz[i] += rowlengths[j];
2859       }
2860       mpicnt = PetscMPIIntCast(rowners[i+1]-rowners[i]);
2861       ierr   = MPI_Send(rowlengths,mpicnt,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2862     }
2863     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
2864   } else {
2865     mpicnt = PetscMPIIntCast(m);CHKERRQ(ierr);
2866     ierr   = MPI_Recv(ourlens,mpicnt,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
2867   }
2868 
2869   if (!rank) {
2870     /* determine max buffer needed and allocate it */
2871     maxnz = 0;
2872     for (i=0; i<size; i++) {
2873       maxnz = PetscMax(maxnz,procsnz[i]);
2874     }
2875     ierr = PetscMalloc(maxnz*sizeof(PetscInt),&cols);CHKERRQ(ierr);
2876 
2877     /* read in my part of the matrix column indices  */
2878     nz   = procsnz[0];
2879     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
2880     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
2881 
2882     /* read in every one elses and ship off */
2883     for (i=1; i<size; i++) {
2884       nz     = procsnz[i];
2885       ierr   = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
2886       mpicnt = PetscMPIIntCast(nz);
2887       ierr   = MPI_Send(cols,mpicnt,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
2888     }
2889     ierr = PetscFree(cols);CHKERRQ(ierr);
2890   } else {
2891     /* determine buffer space needed for message */
2892     nz = 0;
2893     for (i=0; i<m; i++) {
2894       nz += ourlens[i];
2895     }
2896     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
2897 
2898     /* receive message of column indices*/
2899     mpicnt = PetscMPIIntCast(nz);CHKERRQ(ierr);
2900     ierr = MPI_Recv(mycols,mpicnt,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
2901     ierr = MPI_Get_count(&status,MPIU_INT,&mpimaxnz);CHKERRQ(ierr);
2902     if (mpimaxnz == MPI_UNDEFINED) {SETERRQ1(PETSC_ERR_LIB,"MPI_Get_count() returned MPI_UNDEFINED, expected %d",mpicnt);}
2903     else if (mpimaxnz < 0) {SETERRQ2(PETSC_ERR_LIB,"MPI_Get_count() returned impossible negative value %d, expected %d",mpimaxnz,mpicnt);}
2904     else if (mpimaxnz != mpicnt) {SETERRQ2(PETSC_ERR_FILE_UNEXPECTED,"something is wrong with file: expected %d received %d",mpicnt,mpimaxnz);}
2905   }
2906 
2907   /* determine column ownership if matrix is not square */
2908   if (N != M) {
2909     n      = N/size + ((N % size) > rank);
2910     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
2911     cstart = cend - n;
2912   } else {
2913     cstart = rstart;
2914     cend   = rend;
2915     n      = cend - cstart;
2916   }
2917 
2918   /* loop over local rows, determining number of off diagonal entries */
2919   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
2920   jj = 0;
2921   for (i=0; i<m; i++) {
2922     for (j=0; j<ourlens[i]; j++) {
2923       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
2924       jj++;
2925     }
2926   }
2927 
2928   /* create our matrix */
2929   for (i=0; i<m; i++) {
2930     ourlens[i] -= offlens[i];
2931   }
2932   ierr = MatCreate(comm,&A);CHKERRQ(ierr);
2933   ierr = MatSetSizes(A,m,n,M,N);CHKERRQ(ierr);
2934   ierr = MatSetType(A,type);CHKERRQ(ierr);
2935   ierr = MatMPIAIJSetPreallocation(A,0,ourlens,0,offlens);CHKERRQ(ierr);
2936 
2937   for (i=0; i<m; i++) {
2938     ourlens[i] += offlens[i];
2939   }
2940 
2941   if (!rank) {
2942     ierr = PetscMalloc((maxnz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
2943 
2944     /* read in my part of the matrix numerical values  */
2945     nz   = procsnz[0];
2946     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2947 
2948     /* insert into matrix */
2949     jj      = rstart;
2950     smycols = mycols;
2951     svals   = vals;
2952     for (i=0; i<m; i++) {
2953       ierr = MatSetValues_MPIAIJ(A,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2954       smycols += ourlens[i];
2955       svals   += ourlens[i];
2956       jj++;
2957     }
2958 
2959     /* read in other processors and ship out */
2960     for (i=1; i<size; i++) {
2961       nz     = procsnz[i];
2962       ierr   = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
2963       mpicnt = PetscMPIIntCast(nz);
2964       ierr   = MPI_Send(vals,mpicnt,MPIU_SCALAR,i,((PetscObject)A)->tag,comm);CHKERRQ(ierr);
2965     }
2966     ierr = PetscFree(procsnz);CHKERRQ(ierr);
2967   } else {
2968     /* receive numeric values */
2969     ierr = PetscMalloc((nz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
2970 
2971     /* receive message of values*/
2972     mpicnt = PetscMPIIntCast(nz);
2973     ierr   = MPI_Recv(vals,mpicnt,MPIU_SCALAR,0,((PetscObject)A)->tag,comm,&status);CHKERRQ(ierr);
2974     ierr   = MPI_Get_count(&status,MPIU_SCALAR,&mpimaxnz);CHKERRQ(ierr);
2975     if (mpimaxnz == MPI_UNDEFINED) {SETERRQ1(PETSC_ERR_LIB,"MPI_Get_count() returned MPI_UNDEFINED, expected %d",mpicnt);}
2976     else if (mpimaxnz < 0) {SETERRQ2(PETSC_ERR_LIB,"MPI_Get_count() returned impossible negative value %d, expected %d",mpimaxnz,mpicnt);}
2977     else if (mpimaxnz != mpicnt) {SETERRQ2(PETSC_ERR_FILE_UNEXPECTED,"something is wrong with file: expected %d received %d",mpicnt,mpimaxnz);}
2978 
2979     /* insert into matrix */
2980     jj      = rstart;
2981     smycols = mycols;
2982     svals   = vals;
2983     for (i=0; i<m; i++) {
2984       ierr     = MatSetValues_MPIAIJ(A,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
2985       smycols += ourlens[i];
2986       svals   += ourlens[i];
2987       jj++;
2988     }
2989   }
2990   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
2991   ierr = PetscFree(vals);CHKERRQ(ierr);
2992   ierr = PetscFree(mycols);CHKERRQ(ierr);
2993   ierr = PetscFree(rowners);CHKERRQ(ierr);
2994 
2995   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2996   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2997   *newmat = A;
2998   PetscFunctionReturn(0);
2999 }
3000 
3001 #undef __FUNCT__
3002 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3003 /*
3004     Not great since it makes two copies of the submatrix, first an SeqAIJ
3005   in local and then by concatenating the local matrices the end result.
3006   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3007 */
3008 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3009 {
3010   PetscErrorCode ierr;
3011   PetscMPIInt    rank,size;
3012   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j;
3013   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal;
3014   Mat            *local,M,Mreuse;
3015   MatScalar      *vwork,*aa;
3016   MPI_Comm       comm = ((PetscObject)mat)->comm;
3017   Mat_SeqAIJ     *aij;
3018 
3019 
3020   PetscFunctionBegin;
3021   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3022   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3023 
3024   if (call ==  MAT_REUSE_MATRIX) {
3025     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject *)&Mreuse);CHKERRQ(ierr);
3026     if (!Mreuse) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3027     local = &Mreuse;
3028     ierr  = MatGetSubMatrices(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&local);CHKERRQ(ierr);
3029   } else {
3030     ierr   = MatGetSubMatrices(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&local);CHKERRQ(ierr);
3031     Mreuse = *local;
3032     ierr   = PetscFree(local);CHKERRQ(ierr);
3033   }
3034 
3035   /*
3036       m - number of local rows
3037       n - number of columns (same on all processors)
3038       rstart - first row in new global matrix generated
3039   */
3040   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3041   if (call == MAT_INITIAL_MATRIX) {
3042     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3043     ii  = aij->i;
3044     jj  = aij->j;
3045 
3046     /*
3047         Determine the number of non-zeros in the diagonal and off-diagonal
3048         portions of the matrix in order to do correct preallocation
3049     */
3050 
3051     /* first get start and end of "diagonal" columns */
3052     if (csize == PETSC_DECIDE) {
3053       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3054       if (mglobal == n) { /* square matrix */
3055 	nlocal = m;
3056       } else {
3057         nlocal = n/size + ((n % size) > rank);
3058       }
3059     } else {
3060       nlocal = csize;
3061     }
3062     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3063     rstart = rend - nlocal;
3064     if (rank == size - 1 && rend != n) {
3065       SETERRQ2(PETSC_ERR_ARG_SIZ,"Local column sizes %D do not add up to total number of columns %D",rend,n);
3066     }
3067 
3068     /* next, compute all the lengths */
3069     ierr  = PetscMalloc((2*m+1)*sizeof(PetscInt),&dlens);CHKERRQ(ierr);
3070     olens = dlens + m;
3071     for (i=0; i<m; i++) {
3072       jend = ii[i+1] - ii[i];
3073       olen = 0;
3074       dlen = 0;
3075       for (j=0; j<jend; j++) {
3076         if (*jj < rstart || *jj >= rend) olen++;
3077         else dlen++;
3078         jj++;
3079       }
3080       olens[i] = olen;
3081       dlens[i] = dlen;
3082     }
3083     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3084     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3085     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3086     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3087     ierr = PetscFree(dlens);CHKERRQ(ierr);
3088   } else {
3089     PetscInt ml,nl;
3090 
3091     M = *newmat;
3092     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3093     if (ml != m) SETERRQ(PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3094     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3095     /*
3096          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3097        rather than the slower MatSetValues().
3098     */
3099     M->was_assembled = PETSC_TRUE;
3100     M->assembled     = PETSC_FALSE;
3101   }
3102   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3103   aij = (Mat_SeqAIJ*)(Mreuse)->data;
3104   ii  = aij->i;
3105   jj  = aij->j;
3106   aa  = aij->a;
3107   for (i=0; i<m; i++) {
3108     row   = rstart + i;
3109     nz    = ii[i+1] - ii[i];
3110     cwork = jj;     jj += nz;
3111     vwork = aa;     aa += nz;
3112     ierr = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3113   }
3114 
3115   ierr = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3116   ierr = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3117   *newmat = M;
3118 
3119   /* save submatrix used in processor for next request */
3120   if (call ==  MAT_INITIAL_MATRIX) {
3121     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3122     ierr = PetscObjectDereference((PetscObject)Mreuse);CHKERRQ(ierr);
3123   }
3124 
3125   PetscFunctionReturn(0);
3126 }
3127 
3128 EXTERN_C_BEGIN
3129 #undef __FUNCT__
3130 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3131 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3132 {
3133   PetscInt       m,cstart, cend,j,nnz,i,d;
3134   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3135   const PetscInt *JJ;
3136   PetscScalar    *values;
3137   PetscErrorCode ierr;
3138 
3139   PetscFunctionBegin;
3140   if (Ii[0]) SETERRQ1(PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3141 
3142   ierr = PetscMapSetBlockSize(B->rmap,1);CHKERRQ(ierr);
3143   ierr = PetscMapSetBlockSize(B->cmap,1);CHKERRQ(ierr);
3144   ierr = PetscMapSetUp(B->rmap);CHKERRQ(ierr);
3145   ierr = PetscMapSetUp(B->cmap);CHKERRQ(ierr);
3146   m      = B->rmap->n;
3147   cstart = B->cmap->rstart;
3148   cend   = B->cmap->rend;
3149   rstart = B->rmap->rstart;
3150 
3151   ierr  = PetscMalloc((2*m+1)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr);
3152   o_nnz = d_nnz + m;
3153 
3154 #if defined(PETSC_USE_DEBUGGING)
3155   for (i=0; i<m; i++) {
3156     nnz     = Ii[i+1]- Ii[i];
3157     JJ      = J + Ii[i];
3158     if (nnz < 0) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3159     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3160     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);
3161     for (j=1; j<nnz; j++) {
3162       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);
3163     }
3164   }
3165 #endif
3166 
3167   for (i=0; i<m; i++) {
3168     nnz     = Ii[i+1]- Ii[i];
3169     JJ      = J + Ii[i];
3170     nnz_max = PetscMax(nnz_max,nnz);
3171     for (j=0; j<nnz; j++) {
3172       if (*JJ >= cstart) break;
3173       JJ++;
3174     }
3175     d = 0;
3176     for (; j<nnz; j++) {
3177       if (*JJ++ >= cend) break;
3178       d++;
3179     }
3180     d_nnz[i] = d;
3181     o_nnz[i] = nnz - d;
3182   }
3183   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3184   ierr = PetscFree(d_nnz);CHKERRQ(ierr);
3185 
3186   if (v) values = (PetscScalar*)v;
3187   else {
3188     ierr = PetscMalloc((nnz_max+1)*sizeof(PetscScalar),&values);CHKERRQ(ierr);
3189     ierr = PetscMemzero(values,nnz_max*sizeof(PetscScalar));CHKERRQ(ierr);
3190   }
3191 
3192   for (i=0; i<m; i++) {
3193     ii   = i + rstart;
3194     nnz  = Ii[i+1]- Ii[i];
3195     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3196   }
3197   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3198   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3199 
3200   if (!v) {
3201     ierr = PetscFree(values);CHKERRQ(ierr);
3202   }
3203   PetscFunctionReturn(0);
3204 }
3205 EXTERN_C_END
3206 
3207 #undef __FUNCT__
3208 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3209 /*@
3210    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3211    (the default parallel PETSc format).
3212 
3213    Collective on MPI_Comm
3214 
3215    Input Parameters:
3216 +  B - the matrix
3217 .  i - the indices into j for the start of each local row (starts with zero)
3218 .  j - the column indices for each local row (starts with zero) these must be sorted for each row
3219 -  v - optional values in the matrix
3220 
3221    Level: developer
3222 
3223    Notes:
3224        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3225      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3226      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3227 
3228        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3229 
3230        The format which is used for the sparse matrix input, is equivalent to a
3231     row-major ordering.. i.e for the following matrix, the input data expected is
3232     as shown:
3233 
3234         1 0 0
3235         2 0 3     P0
3236        -------
3237         4 5 6     P1
3238 
3239      Process0 [P0]: rows_owned=[0,1]
3240         i =  {0,1,3}  [size = nrow+1  = 2+1]
3241         j =  {0,0,2}  [size = nz = 6]
3242         v =  {1,2,3}  [size = nz = 6]
3243 
3244      Process1 [P1]: rows_owned=[2]
3245         i =  {0,3}    [size = nrow+1  = 1+1]
3246         j =  {0,1,2}  [size = nz = 6]
3247         v =  {4,5,6}  [size = nz = 6]
3248 
3249       The column indices for each row MUST be sorted.
3250 
3251 .keywords: matrix, aij, compressed row, sparse, parallel
3252 
3253 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateMPIAIJ(), MPIAIJ,
3254           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3255 @*/
3256 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3257 {
3258   PetscErrorCode ierr,(*f)(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]);
3259 
3260   PetscFunctionBegin;
3261   ierr = PetscObjectQueryFunction((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",(void (**)(void))&f);CHKERRQ(ierr);
3262   if (f) {
3263     ierr = (*f)(B,i,j,v);CHKERRQ(ierr);
3264   }
3265   PetscFunctionReturn(0);
3266 }
3267 
3268 #undef __FUNCT__
3269 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3270 /*@C
3271    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3272    (the default parallel PETSc format).  For good matrix assembly performance
3273    the user should preallocate the matrix storage by setting the parameters
3274    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3275    performance can be increased by more than a factor of 50.
3276 
3277    Collective on MPI_Comm
3278 
3279    Input Parameters:
3280 +  A - the matrix
3281 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3282            (same value is used for all local rows)
3283 .  d_nnz - array containing the number of nonzeros in the various rows of the
3284            DIAGONAL portion of the local submatrix (possibly different for each row)
3285            or PETSC_NULL, if d_nz is used to specify the nonzero structure.
3286            The size of this array is equal to the number of local rows, i.e 'm'.
3287            You must leave room for the diagonal entry even if it is zero.
3288 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3289            submatrix (same value is used for all local rows).
3290 -  o_nnz - array containing the number of nonzeros in the various rows of the
3291            OFF-DIAGONAL portion of the local submatrix (possibly different for
3292            each row) or PETSC_NULL, if o_nz is used to specify the nonzero
3293            structure. The size of this array is equal to the number
3294            of local rows, i.e 'm'.
3295 
3296    If the *_nnz parameter is given then the *_nz parameter is ignored
3297 
3298    The AIJ format (also called the Yale sparse matrix format or
3299    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3300    storage.  The stored row and column indices begin with zero.  See the users manual for details.
3301 
3302    The parallel matrix is partitioned such that the first m0 rows belong to
3303    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3304    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3305 
3306    The DIAGONAL portion of the local submatrix of a processor can be defined
3307    as the submatrix which is obtained by extraction the part corresponding
3308    to the rows r1-r2 and columns r1-r2 of the global matrix, where r1 is the
3309    first row that belongs to the processor, and r2 is the last row belonging
3310    to the this processor. This is a square mxm matrix. The remaining portion
3311    of the local submatrix (mxN) constitute the OFF-DIAGONAL portion.
3312 
3313    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3314 
3315    You can call MatGetInfo() to get information on how effective the preallocation was;
3316    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3317    You can also run with the option -info and look for messages with the string
3318    malloc in them to see if additional memory allocation was needed.
3319 
3320    Example usage:
3321 
3322    Consider the following 8x8 matrix with 34 non-zero values, that is
3323    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3324    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3325    as follows:
3326 
3327 .vb
3328             1  2  0  |  0  3  0  |  0  4
3329     Proc0   0  5  6  |  7  0  0  |  8  0
3330             9  0 10  | 11  0  0  | 12  0
3331     -------------------------------------
3332            13  0 14  | 15 16 17  |  0  0
3333     Proc1   0 18  0  | 19 20 21  |  0  0
3334             0  0  0  | 22 23  0  | 24  0
3335     -------------------------------------
3336     Proc2  25 26 27  |  0  0 28  | 29  0
3337            30  0  0  | 31 32 33  |  0 34
3338 .ve
3339 
3340    This can be represented as a collection of submatrices as:
3341 
3342 .vb
3343       A B C
3344       D E F
3345       G H I
3346 .ve
3347 
3348    Where the submatrices A,B,C are owned by proc0, D,E,F are
3349    owned by proc1, G,H,I are owned by proc2.
3350 
3351    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3352    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3353    The 'M','N' parameters are 8,8, and have the same values on all procs.
3354 
3355    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3356    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3357    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3358    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3359    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3360    matrix, ans [DF] as another SeqAIJ matrix.
3361 
3362    When d_nz, o_nz parameters are specified, d_nz storage elements are
3363    allocated for every row of the local diagonal submatrix, and o_nz
3364    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3365    One way to choose d_nz and o_nz is to use the max nonzerors per local
3366    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3367    In this case, the values of d_nz,o_nz are:
3368 .vb
3369      proc0 : dnz = 2, o_nz = 2
3370      proc1 : dnz = 3, o_nz = 2
3371      proc2 : dnz = 1, o_nz = 4
3372 .ve
3373    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3374    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3375    for proc3. i.e we are using 12+15+10=37 storage locations to store
3376    34 values.
3377 
3378    When d_nnz, o_nnz parameters are specified, the storage is specified
3379    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3380    In the above case the values for d_nnz,o_nnz are:
3381 .vb
3382      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3383      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3384      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3385 .ve
3386    Here the space allocated is sum of all the above values i.e 34, and
3387    hence pre-allocation is perfect.
3388 
3389    Level: intermediate
3390 
3391 .keywords: matrix, aij, compressed row, sparse, parallel
3392 
3393 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateMPIAIJ(), MatMPIAIJSetPreallocationCSR(),
3394           MPIAIJ, MatGetInfo()
3395 @*/
3396 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3397 {
3398   PetscErrorCode ierr,(*f)(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]);
3399 
3400   PetscFunctionBegin;
3401   ierr = PetscObjectQueryFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",(void (**)(void))&f);CHKERRQ(ierr);
3402   if (f) {
3403     ierr = (*f)(B,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
3404   }
3405   PetscFunctionReturn(0);
3406 }
3407 
3408 #undef __FUNCT__
3409 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3410 /*@
3411      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3412          CSR format the local rows.
3413 
3414    Collective on MPI_Comm
3415 
3416    Input Parameters:
3417 +  comm - MPI communicator
3418 .  m - number of local rows (Cannot be PETSC_DECIDE)
3419 .  n - This value should be the same as the local size used in creating the
3420        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3421        calculated if N is given) For square matrices n is almost always m.
3422 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3423 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3424 .   i - row indices
3425 .   j - column indices
3426 -   a - matrix values
3427 
3428    Output Parameter:
3429 .   mat - the matrix
3430 
3431    Level: intermediate
3432 
3433    Notes:
3434        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3435      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3436      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3437 
3438        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3439 
3440        The format which is used for the sparse matrix input, is equivalent to a
3441     row-major ordering.. i.e for the following matrix, the input data expected is
3442     as shown:
3443 
3444         1 0 0
3445         2 0 3     P0
3446        -------
3447         4 5 6     P1
3448 
3449      Process0 [P0]: rows_owned=[0,1]
3450         i =  {0,1,3}  [size = nrow+1  = 2+1]
3451         j =  {0,0,2}  [size = nz = 6]
3452         v =  {1,2,3}  [size = nz = 6]
3453 
3454      Process1 [P1]: rows_owned=[2]
3455         i =  {0,3}    [size = nrow+1  = 1+1]
3456         j =  {0,1,2}  [size = nz = 6]
3457         v =  {4,5,6}  [size = nz = 6]
3458 
3459 .keywords: matrix, aij, compressed row, sparse, parallel
3460 
3461 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3462           MPIAIJ, MatCreateMPIAIJ(), MatCreateMPIAIJWithSplitArrays()
3463 @*/
3464 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)
3465 {
3466   PetscErrorCode ierr;
3467 
3468  PetscFunctionBegin;
3469   if (i[0]) {
3470     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
3471   }
3472   if (m < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
3473   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
3474   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
3475   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
3476   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
3477   PetscFunctionReturn(0);
3478 }
3479 
3480 #undef __FUNCT__
3481 #define __FUNCT__ "MatCreateMPIAIJ"
3482 /*@C
3483    MatCreateMPIAIJ - Creates a sparse parallel matrix in AIJ format
3484    (the default parallel PETSc format).  For good matrix assembly performance
3485    the user should preallocate the matrix storage by setting the parameters
3486    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3487    performance can be increased by more than a factor of 50.
3488 
3489    Collective on MPI_Comm
3490 
3491    Input Parameters:
3492 +  comm - MPI communicator
3493 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
3494            This value should be the same as the local size used in creating the
3495            y vector for the matrix-vector product y = Ax.
3496 .  n - This value should be the same as the local size used in creating the
3497        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3498        calculated if N is given) For square matrices n is almost always m.
3499 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3500 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3501 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3502            (same value is used for all local rows)
3503 .  d_nnz - array containing the number of nonzeros in the various rows of the
3504            DIAGONAL portion of the local submatrix (possibly different for each row)
3505            or PETSC_NULL, if d_nz is used to specify the nonzero structure.
3506            The size of this array is equal to the number of local rows, i.e 'm'.
3507            You must leave room for the diagonal entry even if it is zero.
3508 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3509            submatrix (same value is used for all local rows).
3510 -  o_nnz - array containing the number of nonzeros in the various rows of the
3511            OFF-DIAGONAL portion of the local submatrix (possibly different for
3512            each row) or PETSC_NULL, if o_nz is used to specify the nonzero
3513            structure. The size of this array is equal to the number
3514            of local rows, i.e 'm'.
3515 
3516    Output Parameter:
3517 .  A - the matrix
3518 
3519    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
3520    MatXXXXSetPreallocation() paradgm instead of this routine directly.
3521    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
3522 
3523    Notes:
3524    If the *_nnz parameter is given then the *_nz parameter is ignored
3525 
3526    m,n,M,N parameters specify the size of the matrix, and its partitioning across
3527    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
3528    storage requirements for this matrix.
3529 
3530    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
3531    processor than it must be used on all processors that share the object for
3532    that argument.
3533 
3534    The user MUST specify either the local or global matrix dimensions
3535    (possibly both).
3536 
3537    The parallel matrix is partitioned across processors such that the
3538    first m0 rows belong to process 0, the next m1 rows belong to
3539    process 1, the next m2 rows belong to process 2 etc.. where
3540    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
3541    values corresponding to [m x N] submatrix.
3542 
3543    The columns are logically partitioned with the n0 columns belonging
3544    to 0th partition, the next n1 columns belonging to the next
3545    partition etc.. where n0,n1,n2... are the the input parameter 'n'.
3546 
3547    The DIAGONAL portion of the local submatrix on any given processor
3548    is the submatrix corresponding to the rows and columns m,n
3549    corresponding to the given processor. i.e diagonal matrix on
3550    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
3551    etc. The remaining portion of the local submatrix [m x (N-n)]
3552    constitute the OFF-DIAGONAL portion. The example below better
3553    illustrates this concept.
3554 
3555    For a square global matrix we define each processor's diagonal portion
3556    to be its local rows and the corresponding columns (a square submatrix);
3557    each processor's off-diagonal portion encompasses the remainder of the
3558    local matrix (a rectangular submatrix).
3559 
3560    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3561 
3562    When calling this routine with a single process communicator, a matrix of
3563    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
3564    type of communicator, use the construction mechanism:
3565      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
3566 
3567    By default, this format uses inodes (identical nodes) when possible.
3568    We search for consecutive rows with the same nonzero structure, thereby
3569    reusing matrix information to achieve increased efficiency.
3570 
3571    Options Database Keys:
3572 +  -mat_no_inode  - Do not use inodes
3573 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3574 -  -mat_aij_oneindex - Internally use indexing starting at 1
3575         rather than 0.  Note that when calling MatSetValues(),
3576         the user still MUST index entries starting at 0!
3577 
3578 
3579    Example usage:
3580 
3581    Consider the following 8x8 matrix with 34 non-zero values, that is
3582    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3583    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3584    as follows:
3585 
3586 .vb
3587             1  2  0  |  0  3  0  |  0  4
3588     Proc0   0  5  6  |  7  0  0  |  8  0
3589             9  0 10  | 11  0  0  | 12  0
3590     -------------------------------------
3591            13  0 14  | 15 16 17  |  0  0
3592     Proc1   0 18  0  | 19 20 21  |  0  0
3593             0  0  0  | 22 23  0  | 24  0
3594     -------------------------------------
3595     Proc2  25 26 27  |  0  0 28  | 29  0
3596            30  0  0  | 31 32 33  |  0 34
3597 .ve
3598 
3599    This can be represented as a collection of submatrices as:
3600 
3601 .vb
3602       A B C
3603       D E F
3604       G H I
3605 .ve
3606 
3607    Where the submatrices A,B,C are owned by proc0, D,E,F are
3608    owned by proc1, G,H,I are owned by proc2.
3609 
3610    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3611    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3612    The 'M','N' parameters are 8,8, and have the same values on all procs.
3613 
3614    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3615    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3616    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3617    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3618    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3619    matrix, ans [DF] as another SeqAIJ matrix.
3620 
3621    When d_nz, o_nz parameters are specified, d_nz storage elements are
3622    allocated for every row of the local diagonal submatrix, and o_nz
3623    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3624    One way to choose d_nz and o_nz is to use the max nonzerors per local
3625    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3626    In this case, the values of d_nz,o_nz are:
3627 .vb
3628      proc0 : dnz = 2, o_nz = 2
3629      proc1 : dnz = 3, o_nz = 2
3630      proc2 : dnz = 1, o_nz = 4
3631 .ve
3632    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3633    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3634    for proc3. i.e we are using 12+15+10=37 storage locations to store
3635    34 values.
3636 
3637    When d_nnz, o_nnz parameters are specified, the storage is specified
3638    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3639    In the above case the values for d_nnz,o_nnz are:
3640 .vb
3641      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3642      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3643      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3644 .ve
3645    Here the space allocated is sum of all the above values i.e 34, and
3646    hence pre-allocation is perfect.
3647 
3648    Level: intermediate
3649 
3650 .keywords: matrix, aij, compressed row, sparse, parallel
3651 
3652 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3653           MPIAIJ, MatCreateMPIAIJWithArrays()
3654 @*/
3655 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)
3656 {
3657   PetscErrorCode ierr;
3658   PetscMPIInt    size;
3659 
3660   PetscFunctionBegin;
3661   ierr = MatCreate(comm,A);CHKERRQ(ierr);
3662   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
3663   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3664   if (size > 1) {
3665     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
3666     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
3667   } else {
3668     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
3669     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
3670   }
3671   PetscFunctionReturn(0);
3672 }
3673 
3674 #undef __FUNCT__
3675 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
3676 PetscErrorCode PETSCMAT_DLLEXPORT MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,PetscInt *colmap[])
3677 {
3678   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
3679 
3680   PetscFunctionBegin;
3681   *Ad     = a->A;
3682   *Ao     = a->B;
3683   *colmap = a->garray;
3684   PetscFunctionReturn(0);
3685 }
3686 
3687 #undef __FUNCT__
3688 #define __FUNCT__ "MatSetColoring_MPIAIJ"
3689 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
3690 {
3691   PetscErrorCode ierr;
3692   PetscInt       i;
3693   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3694 
3695   PetscFunctionBegin;
3696   if (coloring->ctype == IS_COLORING_GLOBAL) {
3697     ISColoringValue *allcolors,*colors;
3698     ISColoring      ocoloring;
3699 
3700     /* set coloring for diagonal portion */
3701     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
3702 
3703     /* set coloring for off-diagonal portion */
3704     ierr = ISAllGatherColors(((PetscObject)A)->comm,coloring->n,coloring->colors,PETSC_NULL,&allcolors);CHKERRQ(ierr);
3705     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
3706     for (i=0; i<a->B->cmap->n; i++) {
3707       colors[i] = allcolors[a->garray[i]];
3708     }
3709     ierr = PetscFree(allcolors);CHKERRQ(ierr);
3710     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
3711     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
3712     ierr = ISColoringDestroy(ocoloring);CHKERRQ(ierr);
3713   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
3714     ISColoringValue *colors;
3715     PetscInt        *larray;
3716     ISColoring      ocoloring;
3717 
3718     /* set coloring for diagonal portion */
3719     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
3720     for (i=0; i<a->A->cmap->n; i++) {
3721       larray[i] = i + A->cmap->rstart;
3722     }
3723     ierr = ISGlobalToLocalMappingApply(A->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,PETSC_NULL,larray);CHKERRQ(ierr);
3724     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
3725     for (i=0; i<a->A->cmap->n; i++) {
3726       colors[i] = coloring->colors[larray[i]];
3727     }
3728     ierr = PetscFree(larray);CHKERRQ(ierr);
3729     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
3730     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
3731     ierr = ISColoringDestroy(ocoloring);CHKERRQ(ierr);
3732 
3733     /* set coloring for off-diagonal portion */
3734     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
3735     ierr = ISGlobalToLocalMappingApply(A->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,PETSC_NULL,larray);CHKERRQ(ierr);
3736     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
3737     for (i=0; i<a->B->cmap->n; i++) {
3738       colors[i] = coloring->colors[larray[i]];
3739     }
3740     ierr = PetscFree(larray);CHKERRQ(ierr);
3741     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
3742     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
3743     ierr = ISColoringDestroy(ocoloring);CHKERRQ(ierr);
3744   } else {
3745     SETERRQ1(PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
3746   }
3747 
3748   PetscFunctionReturn(0);
3749 }
3750 
3751 #if defined(PETSC_HAVE_ADIC)
3752 #undef __FUNCT__
3753 #define __FUNCT__ "MatSetValuesAdic_MPIAIJ"
3754 PetscErrorCode MatSetValuesAdic_MPIAIJ(Mat A,void *advalues)
3755 {
3756   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3757   PetscErrorCode ierr;
3758 
3759   PetscFunctionBegin;
3760   ierr = MatSetValuesAdic_SeqAIJ(a->A,advalues);CHKERRQ(ierr);
3761   ierr = MatSetValuesAdic_SeqAIJ(a->B,advalues);CHKERRQ(ierr);
3762   PetscFunctionReturn(0);
3763 }
3764 #endif
3765 
3766 #undef __FUNCT__
3767 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
3768 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
3769 {
3770   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
3771   PetscErrorCode ierr;
3772 
3773   PetscFunctionBegin;
3774   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
3775   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
3776   PetscFunctionReturn(0);
3777 }
3778 
3779 #undef __FUNCT__
3780 #define __FUNCT__ "MatMerge"
3781 /*@
3782       MatMerge - Creates a single large PETSc matrix by concatinating sequential
3783                  matrices from each processor
3784 
3785     Collective on MPI_Comm
3786 
3787    Input Parameters:
3788 +    comm - the communicators the parallel matrix will live on
3789 .    inmat - the input sequential matrices
3790 .    n - number of local columns (or PETSC_DECIDE)
3791 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
3792 
3793    Output Parameter:
3794 .    outmat - the parallel matrix generated
3795 
3796     Level: advanced
3797 
3798    Notes: The number of columns of the matrix in EACH processor MUST be the same.
3799 
3800 @*/
3801 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
3802 {
3803   PetscErrorCode ierr;
3804   PetscInt       m,N,i,rstart,nnz,Ii,*dnz,*onz;
3805   PetscInt       *indx;
3806   PetscScalar    *values;
3807 
3808   PetscFunctionBegin;
3809   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
3810   if (scall == MAT_INITIAL_MATRIX){
3811     /* count nonzeros in each row, for diagonal and off diagonal portion of matrix */
3812     if (n == PETSC_DECIDE){
3813       ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
3814     }
3815     ierr = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3816     rstart -= m;
3817 
3818     ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
3819     for (i=0;i<m;i++) {
3820       ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,PETSC_NULL);CHKERRQ(ierr);
3821       ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
3822       ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,PETSC_NULL);CHKERRQ(ierr);
3823     }
3824     /* This routine will ONLY return MPIAIJ type matrix */
3825     ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
3826     ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
3827     ierr = MatSetType(*outmat,MATMPIAIJ);CHKERRQ(ierr);
3828     ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
3829     ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
3830 
3831   } else if (scall == MAT_REUSE_MATRIX){
3832     ierr = MatGetOwnershipRange(*outmat,&rstart,PETSC_NULL);CHKERRQ(ierr);
3833   } else {
3834     SETERRQ1(PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
3835   }
3836 
3837   for (i=0;i<m;i++) {
3838     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
3839     Ii    = i + rstart;
3840     ierr = MatSetValues(*outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
3841     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
3842   }
3843   ierr = MatDestroy(inmat);CHKERRQ(ierr);
3844   ierr = MatAssemblyBegin(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3845   ierr = MatAssemblyEnd(*outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3846 
3847   PetscFunctionReturn(0);
3848 }
3849 
3850 #undef __FUNCT__
3851 #define __FUNCT__ "MatFileSplit"
3852 PetscErrorCode MatFileSplit(Mat A,char *outfile)
3853 {
3854   PetscErrorCode    ierr;
3855   PetscMPIInt       rank;
3856   PetscInt          m,N,i,rstart,nnz;
3857   size_t            len;
3858   const PetscInt    *indx;
3859   PetscViewer       out;
3860   char              *name;
3861   Mat               B;
3862   const PetscScalar *values;
3863 
3864   PetscFunctionBegin;
3865   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
3866   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
3867   /* Should this be the type of the diagonal block of A? */
3868   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
3869   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
3870   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
3871   ierr = MatSeqAIJSetPreallocation(B,0,PETSC_NULL);CHKERRQ(ierr);
3872   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
3873   for (i=0;i<m;i++) {
3874     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
3875     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
3876     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
3877   }
3878   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3879   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3880 
3881   ierr = MPI_Comm_rank(((PetscObject)A)->comm,&rank);CHKERRQ(ierr);
3882   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
3883   ierr = PetscMalloc((len+5)*sizeof(char),&name);CHKERRQ(ierr);
3884   sprintf(name,"%s.%d",outfile,rank);
3885   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
3886   ierr = PetscFree(name);
3887   ierr = MatView(B,out);CHKERRQ(ierr);
3888   ierr = PetscViewerDestroy(out);CHKERRQ(ierr);
3889   ierr = MatDestroy(B);CHKERRQ(ierr);
3890   PetscFunctionReturn(0);
3891 }
3892 
3893 EXTERN PetscErrorCode MatDestroy_MPIAIJ(Mat);
3894 #undef __FUNCT__
3895 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
3896 PetscErrorCode PETSCMAT_DLLEXPORT MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
3897 {
3898   PetscErrorCode       ierr;
3899   Mat_Merge_SeqsToMPI  *merge;
3900   PetscContainer       container;
3901 
3902   PetscFunctionBegin;
3903   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject *)&container);CHKERRQ(ierr);
3904   if (container) {
3905     ierr = PetscContainerGetPointer(container,(void **)&merge);CHKERRQ(ierr);
3906     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
3907     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
3908     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
3909     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
3910     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
3911     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
3912     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
3913     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
3914     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
3915     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
3916     ierr = PetscFree(merge->rowmap.range);CHKERRQ(ierr);
3917 
3918     ierr = PetscContainerDestroy(container);CHKERRQ(ierr);
3919     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
3920   }
3921   ierr = PetscFree(merge);CHKERRQ(ierr);
3922 
3923   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
3924   PetscFunctionReturn(0);
3925 }
3926 
3927 #include "../src/mat/utils/freespace.h"
3928 #include "petscbt.h"
3929 
3930 #undef __FUNCT__
3931 #define __FUNCT__ "MatMerge_SeqsToMPINumeric"
3932 /*@C
3933       MatMerge_SeqsToMPI - Creates a MPIAIJ matrix by adding sequential
3934                  matrices from each processor
3935 
3936     Collective on MPI_Comm
3937 
3938    Input Parameters:
3939 +    comm - the communicators the parallel matrix will live on
3940 .    seqmat - the input sequential matrices
3941 .    m - number of local rows (or PETSC_DECIDE)
3942 .    n - number of local columns (or PETSC_DECIDE)
3943 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
3944 
3945    Output Parameter:
3946 .    mpimat - the parallel matrix generated
3947 
3948     Level: advanced
3949 
3950    Notes:
3951      The dimensions of the sequential matrix in each processor MUST be the same.
3952      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
3953      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
3954 @*/
3955 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge_SeqsToMPINumeric(Mat seqmat,Mat mpimat)
3956 {
3957   PetscErrorCode       ierr;
3958   MPI_Comm             comm=((PetscObject)mpimat)->comm;
3959   Mat_SeqAIJ           *a=(Mat_SeqAIJ*)seqmat->data;
3960   PetscMPIInt          size,rank,taga,*len_s;
3961   PetscInt             N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj=a->j;
3962   PetscInt             proc,m;
3963   PetscInt             **buf_ri,**buf_rj;
3964   PetscInt             k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
3965   PetscInt             nrows,**buf_ri_k,**nextrow,**nextai;
3966   MPI_Request          *s_waits,*r_waits;
3967   MPI_Status           *status;
3968   MatScalar            *aa=a->a;
3969   MatScalar            **abuf_r,*ba_i;
3970   Mat_Merge_SeqsToMPI  *merge;
3971   PetscContainer       container;
3972 
3973   PetscFunctionBegin;
3974   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
3975 
3976   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3977   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3978 
3979   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject *)&container);CHKERRQ(ierr);
3980   if (container) {
3981     ierr  = PetscContainerGetPointer(container,(void **)&merge);CHKERRQ(ierr);
3982   }
3983   bi     = merge->bi;
3984   bj     = merge->bj;
3985   buf_ri = merge->buf_ri;
3986   buf_rj = merge->buf_rj;
3987 
3988   ierr   = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
3989   owners = merge->rowmap.range;
3990   len_s  = merge->len_s;
3991 
3992   /* send and recv matrix values */
3993   /*-----------------------------*/
3994   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
3995   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
3996 
3997   ierr = PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&s_waits);CHKERRQ(ierr);
3998   for (proc=0,k=0; proc<size; proc++){
3999     if (!len_s[proc]) continue;
4000     i = owners[proc];
4001     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4002     k++;
4003   }
4004 
4005   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4006   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4007   ierr = PetscFree(status);CHKERRQ(ierr);
4008 
4009   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4010   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4011 
4012   /* insert mat values of mpimat */
4013   /*----------------------------*/
4014   ierr = PetscMalloc(N*sizeof(PetscScalar),&ba_i);CHKERRQ(ierr);
4015   ierr = PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);CHKERRQ(ierr);
4016   nextrow = buf_ri_k + merge->nrecv;
4017   nextai  = nextrow + merge->nrecv;
4018 
4019   for (k=0; k<merge->nrecv; k++){
4020     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4021     nrows = *(buf_ri_k[k]);
4022     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4023     nextai[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
4024   }
4025 
4026   /* set values of ba */
4027   m = merge->rowmap.n;
4028   for (i=0; i<m; i++) {
4029     arow = owners[rank] + i;
4030     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4031     bnzi = bi[i+1] - bi[i];
4032     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4033 
4034     /* add local non-zero vals of this proc's seqmat into ba */
4035     anzi = ai[arow+1] - ai[arow];
4036     aj   = a->j + ai[arow];
4037     aa   = a->a + ai[arow];
4038     nextaj = 0;
4039     for (j=0; nextaj<anzi; j++){
4040       if (*(bj_i + j) == aj[nextaj]){ /* bcol == acol */
4041         ba_i[j] += aa[nextaj++];
4042       }
4043     }
4044 
4045     /* add received vals into ba */
4046     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
4047       /* i-th row */
4048       if (i == *nextrow[k]) {
4049         anzi = *(nextai[k]+1) - *nextai[k];
4050         aj   = buf_rj[k] + *(nextai[k]);
4051         aa   = abuf_r[k] + *(nextai[k]);
4052         nextaj = 0;
4053         for (j=0; nextaj<anzi; j++){
4054           if (*(bj_i + j) == aj[nextaj]){ /* bcol == acol */
4055             ba_i[j] += aa[nextaj++];
4056           }
4057         }
4058         nextrow[k]++; nextai[k]++;
4059       }
4060     }
4061     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4062   }
4063   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4064   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4065 
4066   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4067   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4068   ierr = PetscFree(buf_ri_k);CHKERRQ(ierr);
4069   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4070   PetscFunctionReturn(0);
4071 }
4072 
4073 #undef __FUNCT__
4074 #define __FUNCT__ "MatMerge_SeqsToMPISymbolic"
4075 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge_SeqsToMPISymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4076 {
4077   PetscErrorCode       ierr;
4078   Mat                  B_mpi;
4079   Mat_SeqAIJ           *a=(Mat_SeqAIJ*)seqmat->data;
4080   PetscMPIInt          size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4081   PetscInt             **buf_rj,**buf_ri,**buf_ri_k;
4082   PetscInt             M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4083   PetscInt             len,proc,*dnz,*onz;
4084   PetscInt             k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4085   PetscInt             nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4086   MPI_Request          *si_waits,*sj_waits,*ri_waits,*rj_waits;
4087   MPI_Status           *status;
4088   PetscFreeSpaceList   free_space=PETSC_NULL,current_space=PETSC_NULL;
4089   PetscBT              lnkbt;
4090   Mat_Merge_SeqsToMPI  *merge;
4091   PetscContainer       container;
4092 
4093   PetscFunctionBegin;
4094   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4095 
4096   /* make sure it is a PETSc comm */
4097   ierr = PetscCommDuplicate(comm,&comm,PETSC_NULL);CHKERRQ(ierr);
4098   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4099   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4100 
4101   ierr = PetscNew(Mat_Merge_SeqsToMPI,&merge);CHKERRQ(ierr);
4102   ierr = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
4103 
4104   /* determine row ownership */
4105   /*---------------------------------------------------------*/
4106   ierr = PetscMapInitialize(comm,&merge->rowmap);CHKERRQ(ierr);
4107   merge->rowmap.n = m;
4108   merge->rowmap.N = M;
4109   merge->rowmap.bs = 1;
4110   ierr = PetscMapSetUp(&merge->rowmap);CHKERRQ(ierr);
4111   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&len_si);CHKERRQ(ierr);
4112   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&merge->len_s);CHKERRQ(ierr);
4113 
4114   m      = merge->rowmap.n;
4115   M      = merge->rowmap.N;
4116   owners = merge->rowmap.range;
4117 
4118   /* determine the number of messages to send, their lengths */
4119   /*---------------------------------------------------------*/
4120   len_s  = merge->len_s;
4121 
4122   len = 0;  /* length of buf_si[] */
4123   merge->nsend = 0;
4124   for (proc=0; proc<size; proc++){
4125     len_si[proc] = 0;
4126     if (proc == rank){
4127       len_s[proc] = 0;
4128     } else {
4129       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4130       len_s[proc] = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4131     }
4132     if (len_s[proc]) {
4133       merge->nsend++;
4134       nrows = 0;
4135       for (i=owners[proc]; i<owners[proc+1]; i++){
4136         if (ai[i+1] > ai[i]) nrows++;
4137       }
4138       len_si[proc] = 2*(nrows+1);
4139       len += len_si[proc];
4140     }
4141   }
4142 
4143   /* determine the number and length of messages to receive for ij-structure */
4144   /*-------------------------------------------------------------------------*/
4145   ierr = PetscGatherNumberOfMessages(comm,PETSC_NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4146   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4147 
4148   /* post the Irecv of j-structure */
4149   /*-------------------------------*/
4150   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4151   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4152 
4153   /* post the Isend of j-structure */
4154   /*--------------------------------*/
4155   ierr = PetscMalloc((2*merge->nsend+1)*sizeof(MPI_Request),&si_waits);CHKERRQ(ierr);
4156   sj_waits = si_waits + merge->nsend;
4157 
4158   for (proc=0, k=0; proc<size; proc++){
4159     if (!len_s[proc]) continue;
4160     i = owners[proc];
4161     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4162     k++;
4163   }
4164 
4165   /* receives and sends of j-structure are complete */
4166   /*------------------------------------------------*/
4167   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4168   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4169 
4170   /* send and recv i-structure */
4171   /*---------------------------*/
4172   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4173   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4174 
4175   ierr = PetscMalloc((len+1)*sizeof(PetscInt),&buf_s);CHKERRQ(ierr);
4176   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4177   for (proc=0,k=0; proc<size; proc++){
4178     if (!len_s[proc]) continue;
4179     /* form outgoing message for i-structure:
4180          buf_si[0]:                 nrows to be sent
4181                [1:nrows]:           row index (global)
4182                [nrows+1:2*nrows+1]: i-structure index
4183     */
4184     /*-------------------------------------------*/
4185     nrows = len_si[proc]/2 - 1;
4186     buf_si_i    = buf_si + nrows+1;
4187     buf_si[0]   = nrows;
4188     buf_si_i[0] = 0;
4189     nrows = 0;
4190     for (i=owners[proc]; i<owners[proc+1]; i++){
4191       anzi = ai[i+1] - ai[i];
4192       if (anzi) {
4193         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4194         buf_si[nrows+1] = i-owners[proc]; /* local row index */
4195         nrows++;
4196       }
4197     }
4198     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4199     k++;
4200     buf_si += len_si[proc];
4201   }
4202 
4203   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4204   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4205 
4206   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4207   for (i=0; i<merge->nrecv; i++){
4208     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);
4209   }
4210 
4211   ierr = PetscFree(len_si);CHKERRQ(ierr);
4212   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4213   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4214   ierr = PetscFree(si_waits);CHKERRQ(ierr);
4215   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4216   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4217   ierr = PetscFree(status);CHKERRQ(ierr);
4218 
4219   /* compute a local seq matrix in each processor */
4220   /*----------------------------------------------*/
4221   /* allocate bi array and free space for accumulating nonzero column info */
4222   ierr = PetscMalloc((m+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
4223   bi[0] = 0;
4224 
4225   /* create and initialize a linked list */
4226   nlnk = N+1;
4227   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4228 
4229   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4230   len = 0;
4231   len  = ai[owners[rank+1]] - ai[owners[rank]];
4232   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4233   current_space = free_space;
4234 
4235   /* determine symbolic info for each local row */
4236   ierr = PetscMalloc((3*merge->nrecv+1)*sizeof(PetscInt**),&buf_ri_k);CHKERRQ(ierr);
4237   nextrow = buf_ri_k + merge->nrecv;
4238   nextai  = nextrow + merge->nrecv;
4239   for (k=0; k<merge->nrecv; k++){
4240     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4241     nrows = *buf_ri_k[k];
4242     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4243     nextai[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
4244   }
4245 
4246   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4247   len = 0;
4248   for (i=0;i<m;i++) {
4249     bnzi   = 0;
4250     /* add local non-zero cols of this proc's seqmat into lnk */
4251     arow   = owners[rank] + i;
4252     anzi   = ai[arow+1] - ai[arow];
4253     aj     = a->j + ai[arow];
4254     ierr = PetscLLAdd(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4255     bnzi += nlnk;
4256     /* add received col data into lnk */
4257     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
4258       if (i == *nextrow[k]) { /* i-th row */
4259         anzi = *(nextai[k]+1) - *nextai[k];
4260         aj   = buf_rj[k] + *nextai[k];
4261         ierr = PetscLLAdd(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4262         bnzi += nlnk;
4263         nextrow[k]++; nextai[k]++;
4264       }
4265     }
4266     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4267 
4268     /* if free space is not available, make more free space */
4269     if (current_space->local_remaining<bnzi) {
4270       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4271       nspacedouble++;
4272     }
4273     /* copy data into free space, then initialize lnk */
4274     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4275     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4276 
4277     current_space->array           += bnzi;
4278     current_space->local_used      += bnzi;
4279     current_space->local_remaining -= bnzi;
4280 
4281     bi[i+1] = bi[i] + bnzi;
4282   }
4283 
4284   ierr = PetscFree(buf_ri_k);CHKERRQ(ierr);
4285 
4286   ierr = PetscMalloc((bi[m]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
4287   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4288   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4289 
4290   /* create symbolic parallel matrix B_mpi */
4291   /*---------------------------------------*/
4292   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4293   if (n==PETSC_DECIDE) {
4294     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4295   } else {
4296     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4297   }
4298   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4299   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4300   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4301 
4302   /* B_mpi is not ready for use - assembly will be done by MatMerge_SeqsToMPINumeric() */
4303   B_mpi->assembled     = PETSC_FALSE;
4304   B_mpi->ops->destroy  = MatDestroy_MPIAIJ_SeqsToMPI;
4305   merge->bi            = bi;
4306   merge->bj            = bj;
4307   merge->buf_ri        = buf_ri;
4308   merge->buf_rj        = buf_rj;
4309   merge->coi           = PETSC_NULL;
4310   merge->coj           = PETSC_NULL;
4311   merge->owners_co     = PETSC_NULL;
4312 
4313   /* attach the supporting struct to B_mpi for reuse */
4314   ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4315   ierr = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4316   ierr = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4317   *mpimat = B_mpi;
4318 
4319   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4320   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4321   PetscFunctionReturn(0);
4322 }
4323 
4324 #undef __FUNCT__
4325 #define __FUNCT__ "MatMerge_SeqsToMPI"
4326 PetscErrorCode PETSCMAT_DLLEXPORT MatMerge_SeqsToMPI(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4327 {
4328   PetscErrorCode   ierr;
4329 
4330   PetscFunctionBegin;
4331   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4332   if (scall == MAT_INITIAL_MATRIX){
4333     ierr = MatMerge_SeqsToMPISymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4334   }
4335   ierr = MatMerge_SeqsToMPINumeric(seqmat,*mpimat);CHKERRQ(ierr);
4336   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4337   PetscFunctionReturn(0);
4338 }
4339 
4340 #undef __FUNCT__
4341 #define __FUNCT__ "MatGetLocalMat"
4342 /*@
4343      MatGetLocalMat - Creates a SeqAIJ matrix by taking all its local rows
4344 
4345     Not Collective
4346 
4347    Input Parameters:
4348 +    A - the matrix
4349 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4350 
4351    Output Parameter:
4352 .    A_loc - the local sequential matrix generated
4353 
4354     Level: developer
4355 
4356 @*/
4357 PetscErrorCode PETSCMAT_DLLEXPORT MatGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4358 {
4359   PetscErrorCode  ierr;
4360   Mat_MPIAIJ      *mpimat=(Mat_MPIAIJ*)A->data;
4361   Mat_SeqAIJ      *mat,*a=(Mat_SeqAIJ*)(mpimat->A)->data,*b=(Mat_SeqAIJ*)(mpimat->B)->data;
4362   PetscInt        *ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,*cmap=mpimat->garray;
4363   MatScalar       *aa=a->a,*ba=b->a,*cam;
4364   PetscScalar     *ca;
4365   PetscInt        am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4366   PetscInt        *ci,*cj,col,ncols_d,ncols_o,jo;
4367 
4368   PetscFunctionBegin;
4369   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4370   if (scall == MAT_INITIAL_MATRIX){
4371     ierr = PetscMalloc((1+am)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
4372     ci[0] = 0;
4373     for (i=0; i<am; i++){
4374       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4375     }
4376     ierr = PetscMalloc((1+ci[am])*sizeof(PetscInt),&cj);CHKERRQ(ierr);
4377     ierr = PetscMalloc((1+ci[am])*sizeof(PetscScalar),&ca);CHKERRQ(ierr);
4378     k = 0;
4379     for (i=0; i<am; i++) {
4380       ncols_o = bi[i+1] - bi[i];
4381       ncols_d = ai[i+1] - ai[i];
4382       /* off-diagonal portion of A */
4383       for (jo=0; jo<ncols_o; jo++) {
4384         col = cmap[*bj];
4385         if (col >= cstart) break;
4386         cj[k]   = col; bj++;
4387         ca[k++] = *ba++;
4388       }
4389       /* diagonal portion of A */
4390       for (j=0; j<ncols_d; j++) {
4391         cj[k]   = cstart + *aj++;
4392         ca[k++] = *aa++;
4393       }
4394       /* off-diagonal portion of A */
4395       for (j=jo; j<ncols_o; j++) {
4396         cj[k]   = cmap[*bj++];
4397         ca[k++] = *ba++;
4398       }
4399     }
4400     /* put together the new matrix */
4401     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4402     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4403     /* Since these are PETSc arrays, change flags to free them as necessary. */
4404     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4405     mat->free_a  = PETSC_TRUE;
4406     mat->free_ij = PETSC_TRUE;
4407     mat->nonew   = 0;
4408   } else if (scall == MAT_REUSE_MATRIX){
4409     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4410     ci = mat->i; cj = mat->j; cam = mat->a;
4411     for (i=0; i<am; i++) {
4412       /* off-diagonal portion of A */
4413       ncols_o = bi[i+1] - bi[i];
4414       for (jo=0; jo<ncols_o; jo++) {
4415         col = cmap[*bj];
4416         if (col >= cstart) break;
4417         *cam++ = *ba++; bj++;
4418       }
4419       /* diagonal portion of A */
4420       ncols_d = ai[i+1] - ai[i];
4421       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4422       /* off-diagonal portion of A */
4423       for (j=jo; j<ncols_o; j++) {
4424         *cam++ = *ba++; bj++;
4425       }
4426     }
4427   } else {
4428     SETERRQ1(PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
4429   }
4430 
4431   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4432   PetscFunctionReturn(0);
4433 }
4434 
4435 #undef __FUNCT__
4436 #define __FUNCT__ "MatGetLocalMatCondensed"
4437 /*@C
4438      MatGetLocalMatCondensed - Creates a SeqAIJ matrix by taking all its local rows and NON-ZERO columns
4439 
4440     Not Collective
4441 
4442    Input Parameters:
4443 +    A - the matrix
4444 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4445 -    row, col - index sets of rows and columns to extract (or PETSC_NULL)
4446 
4447    Output Parameter:
4448 .    A_loc - the local sequential matrix generated
4449 
4450     Level: developer
4451 
4452 @*/
4453 PetscErrorCode PETSCMAT_DLLEXPORT MatGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
4454 {
4455   Mat_MPIAIJ        *a=(Mat_MPIAIJ*)A->data;
4456   PetscErrorCode    ierr;
4457   PetscInt          i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
4458   IS                isrowa,iscola;
4459   Mat               *aloc;
4460 
4461   PetscFunctionBegin;
4462   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4463   if (!row){
4464     start = A->rmap->rstart; end = A->rmap->rend;
4465     ierr = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
4466   } else {
4467     isrowa = *row;
4468   }
4469   if (!col){
4470     start = A->cmap->rstart;
4471     cmap  = a->garray;
4472     nzA   = a->A->cmap->n;
4473     nzB   = a->B->cmap->n;
4474     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
4475     ncols = 0;
4476     for (i=0; i<nzB; i++) {
4477       if (cmap[i] < start) idx[ncols++] = cmap[i];
4478       else break;
4479     }
4480     imark = i;
4481     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
4482     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
4483     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,&iscola);CHKERRQ(ierr);
4484     ierr = PetscFree(idx);CHKERRQ(ierr);
4485   } else {
4486     iscola = *col;
4487   }
4488   if (scall != MAT_INITIAL_MATRIX){
4489     ierr = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
4490     aloc[0] = *A_loc;
4491   }
4492   ierr = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
4493   *A_loc = aloc[0];
4494   ierr = PetscFree(aloc);CHKERRQ(ierr);
4495   if (!row){
4496     ierr = ISDestroy(isrowa);CHKERRQ(ierr);
4497   }
4498   if (!col){
4499     ierr = ISDestroy(iscola);CHKERRQ(ierr);
4500   }
4501   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
4502   PetscFunctionReturn(0);
4503 }
4504 
4505 #undef __FUNCT__
4506 #define __FUNCT__ "MatGetBrowsOfAcols"
4507 /*@C
4508     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
4509 
4510     Collective on Mat
4511 
4512    Input Parameters:
4513 +    A,B - the matrices in mpiaij format
4514 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4515 -    rowb, colb - index sets of rows and columns of B to extract (or PETSC_NULL)
4516 
4517    Output Parameter:
4518 +    rowb, colb - index sets of rows and columns of B to extract
4519 .    brstart - row index of B_seq from which next B->rmap->n rows are taken from B's local rows
4520 -    B_seq - the sequential matrix generated
4521 
4522     Level: developer
4523 
4524 @*/
4525 PetscErrorCode PETSCMAT_DLLEXPORT MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,PetscInt *brstart,Mat *B_seq)
4526 {
4527   Mat_MPIAIJ        *a=(Mat_MPIAIJ*)A->data;
4528   PetscErrorCode    ierr;
4529   PetscInt          *idx,i,start,ncols,nzA,nzB,*cmap,imark;
4530   IS                isrowb,iscolb;
4531   Mat               *bseq;
4532 
4533   PetscFunctionBegin;
4534   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
4535     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);
4536   }
4537   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
4538 
4539   if (scall == MAT_INITIAL_MATRIX){
4540     start = A->cmap->rstart;
4541     cmap  = a->garray;
4542     nzA   = a->A->cmap->n;
4543     nzB   = a->B->cmap->n;
4544     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
4545     ncols = 0;
4546     for (i=0; i<nzB; i++) {  /* row < local row index */
4547       if (cmap[i] < start) idx[ncols++] = cmap[i];
4548       else break;
4549     }
4550     imark = i;
4551     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
4552     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
4553     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,&isrowb);CHKERRQ(ierr);
4554     ierr = PetscFree(idx);CHKERRQ(ierr);
4555     *brstart = imark;
4556     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
4557   } else {
4558     if (!rowb || !colb) SETERRQ(PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
4559     isrowb = *rowb; iscolb = *colb;
4560     ierr = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
4561     bseq[0] = *B_seq;
4562   }
4563   ierr = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
4564   *B_seq = bseq[0];
4565   ierr = PetscFree(bseq);CHKERRQ(ierr);
4566   if (!rowb){
4567     ierr = ISDestroy(isrowb);CHKERRQ(ierr);
4568   } else {
4569     *rowb = isrowb;
4570   }
4571   if (!colb){
4572     ierr = ISDestroy(iscolb);CHKERRQ(ierr);
4573   } else {
4574     *colb = iscolb;
4575   }
4576   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
4577   PetscFunctionReturn(0);
4578 }
4579 
4580 #undef __FUNCT__
4581 #define __FUNCT__ "MatGetBrowsOfAoCols"
4582 /*@C
4583     MatGetBrowsOfAoCols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
4584     of the OFF-DIAGONAL portion of local A
4585 
4586     Collective on Mat
4587 
4588    Input Parameters:
4589 +    A,B - the matrices in mpiaij format
4590 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4591 .    startsj - starting point in B's sending and receiving j-arrays, saved for MAT_REUSE (or PETSC_NULL)
4592 -    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or PETSC_NULL)
4593 
4594    Output Parameter:
4595 +    B_oth - the sequential matrix generated
4596 
4597     Level: developer
4598 
4599 @*/
4600 PetscErrorCode PETSCMAT_DLLEXPORT MatGetBrowsOfAoCols(Mat A,Mat B,MatReuse scall,PetscInt **startsj,MatScalar **bufa_ptr,Mat *B_oth)
4601 {
4602   VecScatter_MPI_General *gen_to,*gen_from;
4603   PetscErrorCode         ierr;
4604   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
4605   Mat_SeqAIJ             *b_oth;
4606   VecScatter             ctx=a->Mvctx;
4607   MPI_Comm               comm=((PetscObject)ctx)->comm;
4608   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
4609   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
4610   PetscScalar            *rvalues,*svalues;
4611   MatScalar              *b_otha,*bufa,*bufA;
4612   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
4613   MPI_Request            *rwaits = PETSC_NULL,*swaits = PETSC_NULL;
4614   MPI_Status             *sstatus,rstatus;
4615   PetscMPIInt            jj;
4616   PetscInt               *cols,sbs,rbs;
4617   PetscScalar            *vals;
4618 
4619   PetscFunctionBegin;
4620   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
4621     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);
4622   }
4623   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
4624   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4625 
4626   gen_to   = (VecScatter_MPI_General*)ctx->todata;
4627   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
4628   rvalues  = gen_from->values; /* holds the length of receiving row */
4629   svalues  = gen_to->values;   /* holds the length of sending row */
4630   nrecvs   = gen_from->n;
4631   nsends   = gen_to->n;
4632 
4633   ierr = PetscMalloc2(nrecvs,MPI_Request,&rwaits,nsends,MPI_Request,&swaits);CHKERRQ(ierr);
4634   srow     = gen_to->indices;   /* local row index to be sent */
4635   sstarts  = gen_to->starts;
4636   sprocs   = gen_to->procs;
4637   sstatus  = gen_to->sstatus;
4638   sbs      = gen_to->bs;
4639   rstarts  = gen_from->starts;
4640   rprocs   = gen_from->procs;
4641   rbs      = gen_from->bs;
4642 
4643   if (!startsj || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
4644   if (scall == MAT_INITIAL_MATRIX){
4645     /* i-array */
4646     /*---------*/
4647     /*  post receives */
4648     for (i=0; i<nrecvs; i++){
4649       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
4650       nrows = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
4651       ierr = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4652     }
4653 
4654     /* pack the outgoing message */
4655     ierr = PetscMalloc((nsends+nrecvs+3)*sizeof(PetscInt),&sstartsj);CHKERRQ(ierr);
4656     rstartsj = sstartsj + nsends +1;
4657     sstartsj[0] = 0;  rstartsj[0] = 0;
4658     len = 0; /* total length of j or a array to be sent */
4659     k = 0;
4660     for (i=0; i<nsends; i++){
4661       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
4662       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4663       for (j=0; j<nrows; j++) {
4664         row = srow[k] + B->rmap->range[rank]; /* global row idx */
4665         for (l=0; l<sbs; l++){
4666           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); /* rowlength */
4667           rowlen[j*sbs+l] = ncols;
4668           len += ncols;
4669           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
4670         }
4671         k++;
4672       }
4673       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4674       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
4675     }
4676     /* recvs and sends of i-array are completed */
4677     i = nrecvs;
4678     while (i--) {
4679       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4680     }
4681     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4682 
4683     /* allocate buffers for sending j and a arrays */
4684     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&bufj);CHKERRQ(ierr);
4685     ierr = PetscMalloc((len+1)*sizeof(PetscScalar),&bufa);CHKERRQ(ierr);
4686 
4687     /* create i-array of B_oth */
4688     ierr = PetscMalloc((aBn+2)*sizeof(PetscInt),&b_othi);CHKERRQ(ierr);
4689     b_othi[0] = 0;
4690     len = 0; /* total length of j or a array to be received */
4691     k = 0;
4692     for (i=0; i<nrecvs; i++){
4693       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
4694       nrows = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
4695       for (j=0; j<nrows; j++) {
4696         b_othi[k+1] = b_othi[k] + rowlen[j];
4697         len += rowlen[j]; k++;
4698       }
4699       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
4700     }
4701 
4702     /* allocate space for j and a arrrays of B_oth */
4703     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(PetscInt),&b_othj);CHKERRQ(ierr);
4704     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(MatScalar),&b_otha);CHKERRQ(ierr);
4705 
4706     /* j-array */
4707     /*---------*/
4708     /*  post receives of j-array */
4709     for (i=0; i<nrecvs; i++){
4710       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
4711       ierr = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4712     }
4713 
4714     /* pack the outgoing message j-array */
4715     k = 0;
4716     for (i=0; i<nsends; i++){
4717       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4718       bufJ = bufj+sstartsj[i];
4719       for (j=0; j<nrows; j++) {
4720         row  = srow[k++] + B->rmap->range[rank]; /* global row idx */
4721         for (ll=0; ll<sbs; ll++){
4722           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,PETSC_NULL);CHKERRQ(ierr);
4723           for (l=0; l<ncols; l++){
4724             *bufJ++ = cols[l];
4725           }
4726           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,PETSC_NULL);CHKERRQ(ierr);
4727         }
4728       }
4729       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4730     }
4731 
4732     /* recvs and sends of j-array are completed */
4733     i = nrecvs;
4734     while (i--) {
4735       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4736     }
4737     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4738   } else if (scall == MAT_REUSE_MATRIX){
4739     sstartsj = *startsj;
4740     rstartsj = sstartsj + nsends +1;
4741     bufa     = *bufa_ptr;
4742     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
4743     b_otha   = b_oth->a;
4744   } else {
4745     SETERRQ(PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
4746   }
4747 
4748   /* a-array */
4749   /*---------*/
4750   /*  post receives of a-array */
4751   for (i=0; i<nrecvs; i++){
4752     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
4753     ierr = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
4754   }
4755 
4756   /* pack the outgoing message a-array */
4757   k = 0;
4758   for (i=0; i<nsends; i++){
4759     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
4760     bufA = bufa+sstartsj[i];
4761     for (j=0; j<nrows; j++) {
4762       row  = srow[k++] + B->rmap->range[rank]; /* global row idx */
4763       for (ll=0; ll<sbs; ll++){
4764         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,PETSC_NULL,&vals);CHKERRQ(ierr);
4765         for (l=0; l<ncols; l++){
4766           *bufA++ = vals[l];
4767         }
4768         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,PETSC_NULL,&vals);CHKERRQ(ierr);
4769       }
4770     }
4771     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
4772   }
4773   /* recvs and sends of a-array are completed */
4774   i = nrecvs;
4775   while (i--) {
4776     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
4777   }
4778   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
4779   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
4780 
4781   if (scall == MAT_INITIAL_MATRIX){
4782     /* put together the new matrix */
4783     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
4784 
4785     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4786     /* Since these are PETSc arrays, change flags to free them as necessary. */
4787     b_oth          = (Mat_SeqAIJ *)(*B_oth)->data;
4788     b_oth->free_a  = PETSC_TRUE;
4789     b_oth->free_ij = PETSC_TRUE;
4790     b_oth->nonew   = 0;
4791 
4792     ierr = PetscFree(bufj);CHKERRQ(ierr);
4793     if (!startsj || !bufa_ptr){
4794       ierr = PetscFree(sstartsj);CHKERRQ(ierr);
4795       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
4796     } else {
4797       *startsj  = sstartsj;
4798       *bufa_ptr = bufa;
4799     }
4800   }
4801   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
4802   PetscFunctionReturn(0);
4803 }
4804 
4805 #undef __FUNCT__
4806 #define __FUNCT__ "MatGetCommunicationStructs"
4807 /*@C
4808   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
4809 
4810   Not Collective
4811 
4812   Input Parameters:
4813 . A - The matrix in mpiaij format
4814 
4815   Output Parameter:
4816 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
4817 . colmap - A map from global column index to local index into lvec
4818 - multScatter - A scatter from the argument of a matrix-vector product to lvec
4819 
4820   Level: developer
4821 
4822 @*/
4823 #if defined (PETSC_USE_CTABLE)
4824 PetscErrorCode PETSCMAT_DLLEXPORT MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
4825 #else
4826 PetscErrorCode PETSCMAT_DLLEXPORT MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
4827 #endif
4828 {
4829   Mat_MPIAIJ *a;
4830 
4831   PetscFunctionBegin;
4832   PetscValidHeaderSpecific(A, MAT_COOKIE, 1);
4833   PetscValidPointer(lvec, 2)
4834   PetscValidPointer(colmap, 3)
4835   PetscValidPointer(multScatter, 4)
4836   a = (Mat_MPIAIJ *) A->data;
4837   if (lvec) *lvec = a->lvec;
4838   if (colmap) *colmap = a->colmap;
4839   if (multScatter) *multScatter = a->Mvctx;
4840   PetscFunctionReturn(0);
4841 }
4842 
4843 EXTERN_C_BEGIN
4844 extern PetscErrorCode PETSCMAT_DLLEXPORT MatConvert_MPIAIJ_MPICRL(Mat,const MatType,MatReuse,Mat*);
4845 extern PetscErrorCode PETSCMAT_DLLEXPORT MatConvert_MPIAIJ_MPICSRPERM(Mat,const MatType,MatReuse,Mat*);
4846 EXTERN_C_END
4847 
4848 #include "../src/mat/impls/dense/mpi/mpidense.h"
4849 
4850 #undef __FUNCT__
4851 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
4852 /*
4853     Computes (B'*A')' since computing B*A directly is untenable
4854 
4855                n                       p                          p
4856         (              )       (              )         (                  )
4857       m (      A       )  *  n (       B      )   =   m (         C        )
4858         (              )       (              )         (                  )
4859 
4860 */
4861 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
4862 {
4863   PetscErrorCode     ierr;
4864   Mat                At,Bt,Ct;
4865 
4866   PetscFunctionBegin;
4867   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
4868   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
4869   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
4870   ierr = MatDestroy(At);CHKERRQ(ierr);
4871   ierr = MatDestroy(Bt);CHKERRQ(ierr);
4872   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
4873   ierr = MatDestroy(Ct);CHKERRQ(ierr);
4874   PetscFunctionReturn(0);
4875 }
4876 
4877 #undef __FUNCT__
4878 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
4879 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
4880 {
4881   PetscErrorCode ierr;
4882   PetscInt       m=A->rmap->n,n=B->cmap->n;
4883   Mat            Cmat;
4884 
4885   PetscFunctionBegin;
4886   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);
4887   ierr = MatCreate(((PetscObject)A)->comm,&Cmat);CHKERRQ(ierr);
4888   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4889   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
4890   ierr = MatMPIDenseSetPreallocation(Cmat,PETSC_NULL);CHKERRQ(ierr);
4891   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4892   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4893   *C   = Cmat;
4894   PetscFunctionReturn(0);
4895 }
4896 
4897 /* ----------------------------------------------------------------*/
4898 #undef __FUNCT__
4899 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
4900 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
4901 {
4902   PetscErrorCode ierr;
4903 
4904   PetscFunctionBegin;
4905   if (scall == MAT_INITIAL_MATRIX){
4906     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
4907   }
4908   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
4909   PetscFunctionReturn(0);
4910 }
4911 
4912 EXTERN_C_BEGIN
4913 #if defined(PETSC_HAVE_MUMPS)
4914 extern PetscErrorCode MatGetFactor_mpiaij_mumps(Mat,MatFactorType,Mat*);
4915 #endif
4916 #if defined(PETSC_HAVE_PASTIX)
4917 extern PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
4918 #endif
4919 #if defined(PETSC_HAVE_SUPERLU_DIST)
4920 extern PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
4921 #endif
4922 #if defined(PETSC_HAVE_SPOOLES)
4923 extern PetscErrorCode MatGetFactor_mpiaij_spooles(Mat,MatFactorType,Mat*);
4924 #endif
4925 EXTERN_C_END
4926 
4927 /*MC
4928    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
4929 
4930    Options Database Keys:
4931 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
4932 
4933   Level: beginner
4934 
4935 .seealso: MatCreateMPIAIJ()
4936 M*/
4937 
4938 EXTERN_C_BEGIN
4939 #undef __FUNCT__
4940 #define __FUNCT__ "MatCreate_MPIAIJ"
4941 PetscErrorCode PETSCMAT_DLLEXPORT MatCreate_MPIAIJ(Mat B)
4942 {
4943   Mat_MPIAIJ     *b;
4944   PetscErrorCode ierr;
4945   PetscMPIInt    size;
4946 
4947   PetscFunctionBegin;
4948   ierr = MPI_Comm_size(((PetscObject)B)->comm,&size);CHKERRQ(ierr);
4949 
4950   ierr            = PetscNewLog(B,Mat_MPIAIJ,&b);CHKERRQ(ierr);
4951   B->data         = (void*)b;
4952   ierr            = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
4953   B->rmap->bs      = 1;
4954   B->assembled    = PETSC_FALSE;
4955   B->mapping      = 0;
4956 
4957   B->insertmode      = NOT_SET_VALUES;
4958   b->size            = size;
4959   ierr = MPI_Comm_rank(((PetscObject)B)->comm,&b->rank);CHKERRQ(ierr);
4960 
4961   /* build cache for off array entries formed */
4962   ierr = MatStashCreate_Private(((PetscObject)B)->comm,1,&B->stash);CHKERRQ(ierr);
4963   b->donotstash  = PETSC_FALSE;
4964   b->colmap      = 0;
4965   b->garray      = 0;
4966   b->roworiented = PETSC_TRUE;
4967 
4968   /* stuff used for matrix vector multiply */
4969   b->lvec      = PETSC_NULL;
4970   b->Mvctx     = PETSC_NULL;
4971 
4972   /* stuff for MatGetRow() */
4973   b->rowindices   = 0;
4974   b->rowvalues    = 0;
4975   b->getrowactive = PETSC_FALSE;
4976 
4977 #if defined(PETSC_HAVE_SPOOLES)
4978   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_spooles_C",
4979                                      "MatGetFactor_mpiaij_spooles",
4980                                      MatGetFactor_mpiaij_spooles);CHKERRQ(ierr);
4981 #endif
4982 #if defined(PETSC_HAVE_MUMPS)
4983   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_mumps_C",
4984                                      "MatGetFactor_mpiaij_mumps",
4985                                      MatGetFactor_mpiaij_mumps);CHKERRQ(ierr);
4986 #endif
4987 #if defined(PETSC_HAVE_PASTIX)
4988   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_pastix_C",
4989 					   "MatGetFactor_mpiaij_pastix",
4990 					   MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
4991 #endif
4992 #if defined(PETSC_HAVE_SUPERLU_DIST)
4993   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mpiaij_superlu_dist_C",
4994                                      "MatGetFactor_mpiaij_superlu_dist",
4995                                      MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
4996 #endif
4997   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatStoreValues_C",
4998                                      "MatStoreValues_MPIAIJ",
4999                                      MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5000   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatRetrieveValues_C",
5001                                      "MatRetrieveValues_MPIAIJ",
5002                                      MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5003   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetDiagonalBlock_C",
5004 				     "MatGetDiagonalBlock_MPIAIJ",
5005                                      MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5006   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatIsTranspose_C",
5007 				     "MatIsTranspose_MPIAIJ",
5008 				     MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5009   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMPIAIJSetPreallocation_C",
5010 				     "MatMPIAIJSetPreallocation_MPIAIJ",
5011 				     MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5012   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",
5013 				     "MatMPIAIJSetPreallocationCSR_MPIAIJ",
5014 				     MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5015   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatDiagonalScaleLocal_C",
5016 				     "MatDiagonalScaleLocal_MPIAIJ",
5017 				     MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5018   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpicsrperm_C",
5019                                      "MatConvert_MPIAIJ_MPICSRPERM",
5020                                       MatConvert_MPIAIJ_MPICSRPERM);CHKERRQ(ierr);
5021   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpicrl_C",
5022                                      "MatConvert_MPIAIJ_MPICRL",
5023                                       MatConvert_MPIAIJ_MPICRL);CHKERRQ(ierr);
5024   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",
5025                                      "MatMatMult_MPIDense_MPIAIJ",
5026                                       MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5027   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",
5028                                      "MatMatMultSymbolic_MPIDense_MPIAIJ",
5029                                       MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5030   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",
5031                                      "MatMatMultNumeric_MPIDense_MPIAIJ",
5032                                       MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5033   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5034   PetscFunctionReturn(0);
5035 }
5036 EXTERN_C_END
5037 
5038 #undef __FUNCT__
5039 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5040 /*@
5041      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5042          and "off-diagonal" part of the matrix in CSR format.
5043 
5044    Collective on MPI_Comm
5045 
5046    Input Parameters:
5047 +  comm - MPI communicator
5048 .  m - number of local rows (Cannot be PETSC_DECIDE)
5049 .  n - This value should be the same as the local size used in creating the
5050        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5051        calculated if N is given) For square matrices n is almost always m.
5052 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5053 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5054 .   i - row indices for "diagonal" portion of matrix
5055 .   j - column indices
5056 .   a - matrix values
5057 .   oi - row indices for "off-diagonal" portion of matrix
5058 .   oj - column indices
5059 -   oa - matrix values
5060 
5061    Output Parameter:
5062 .   mat - the matrix
5063 
5064    Level: advanced
5065 
5066    Notes:
5067        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc.
5068 
5069        The i and j indices are 0 based
5070 
5071        See MatCreateMPIAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5072 
5073 
5074 .keywords: matrix, aij, compressed row, sparse, parallel
5075 
5076 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5077           MPIAIJ, MatCreateMPIAIJ(), MatCreateMPIAIJWithArrays()
5078 @*/
5079 PetscErrorCode PETSCMAT_DLLEXPORT MatCreateMPIAIJWithSplitArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt i[],PetscInt j[],PetscScalar a[],
5080 								PetscInt oi[], PetscInt oj[],PetscScalar oa[],Mat *mat)
5081 {
5082   PetscErrorCode ierr;
5083   Mat_MPIAIJ     *maij;
5084 
5085  PetscFunctionBegin;
5086   if (m < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5087   if (i[0]) {
5088     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5089   }
5090   if (oi[0]) {
5091     SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5092   }
5093   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5094   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5095   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5096   maij = (Mat_MPIAIJ*) (*mat)->data;
5097   maij->donotstash     = PETSC_TRUE;
5098   (*mat)->preallocated = PETSC_TRUE;
5099 
5100   ierr = PetscMapSetBlockSize((*mat)->rmap,1);CHKERRQ(ierr);
5101   ierr = PetscMapSetBlockSize((*mat)->cmap,1);CHKERRQ(ierr);
5102   ierr = PetscMapSetUp((*mat)->rmap);CHKERRQ(ierr);
5103   ierr = PetscMapSetUp((*mat)->cmap);CHKERRQ(ierr);
5104 
5105   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5106   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5107 
5108   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5109   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5110   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5111   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5112 
5113   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5114   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5115   PetscFunctionReturn(0);
5116 }
5117 
5118 /*
5119     Special version for direct calls from Fortran
5120 */
5121 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5122 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5123 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5124 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5125 #endif
5126 
5127 /* Change these macros so can be used in void function */
5128 #undef CHKERRQ
5129 #define CHKERRQ(ierr) CHKERRABORT(((PetscObject)mat)->comm,ierr)
5130 #undef SETERRQ2
5131 #define SETERRQ2(ierr,b,c,d) CHKERRABORT(((PetscObject)mat)->comm,ierr)
5132 #undef SETERRQ
5133 #define SETERRQ(ierr,b) CHKERRABORT(((PetscObject)mat)->comm,ierr)
5134 
5135 EXTERN_C_BEGIN
5136 #undef __FUNCT__
5137 #define __FUNCT__ "matsetvaluesmpiaij_"
5138 void PETSC_STDCALL matsetvaluesmpiaij_(Mat *mmat,PetscInt *mm,const PetscInt im[],PetscInt *mn,const PetscInt in[],const PetscScalar v[],InsertMode *maddv,PetscErrorCode *_ierr)
5139 {
5140   Mat             mat = *mmat;
5141   PetscInt        m = *mm, n = *mn;
5142   InsertMode      addv = *maddv;
5143   Mat_MPIAIJ      *aij = (Mat_MPIAIJ*)mat->data;
5144   PetscScalar     value;
5145   PetscErrorCode  ierr;
5146 
5147   ierr = MatPreallocated(mat);CHKERRQ(ierr);
5148   if (mat->insertmode == NOT_SET_VALUES) {
5149     mat->insertmode = addv;
5150   }
5151 #if defined(PETSC_USE_DEBUG)
5152   else if (mat->insertmode != addv) {
5153     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5154   }
5155 #endif
5156   {
5157   PetscInt        i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
5158   PetscInt        cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5159   PetscTruth      roworiented = aij->roworiented;
5160 
5161   /* Some Variables required in the macro */
5162   Mat             A = aij->A;
5163   Mat_SeqAIJ      *a = (Mat_SeqAIJ*)A->data;
5164   PetscInt        *aimax = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5165   MatScalar       *aa = a->a;
5166   PetscTruth      ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES))?PETSC_TRUE:PETSC_FALSE);
5167   Mat             B = aij->B;
5168   Mat_SeqAIJ      *b = (Mat_SeqAIJ*)B->data;
5169   PetscInt        *bimax = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5170   MatScalar       *ba = b->a;
5171 
5172   PetscInt        *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5173   PetscInt        nonew = a->nonew;
5174   MatScalar       *ap1,*ap2;
5175 
5176   PetscFunctionBegin;
5177   for (i=0; i<m; i++) {
5178     if (im[i] < 0) continue;
5179 #if defined(PETSC_USE_DEBUG)
5180     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
5181 #endif
5182     if (im[i] >= rstart && im[i] < rend) {
5183       row      = im[i] - rstart;
5184       lastcol1 = -1;
5185       rp1      = aj + ai[row];
5186       ap1      = aa + ai[row];
5187       rmax1    = aimax[row];
5188       nrow1    = ailen[row];
5189       low1     = 0;
5190       high1    = nrow1;
5191       lastcol2 = -1;
5192       rp2      = bj + bi[row];
5193       ap2      = ba + bi[row];
5194       rmax2    = bimax[row];
5195       nrow2    = bilen[row];
5196       low2     = 0;
5197       high2    = nrow2;
5198 
5199       for (j=0; j<n; j++) {
5200         if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
5201         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5202         if (in[j] >= cstart && in[j] < cend){
5203           col = in[j] - cstart;
5204           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5205         } else if (in[j] < 0) continue;
5206 #if defined(PETSC_USE_DEBUG)
5207         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);}
5208 #endif
5209         else {
5210           if (mat->was_assembled) {
5211             if (!aij->colmap) {
5212               ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5213             }
5214 #if defined (PETSC_USE_CTABLE)
5215             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5216 	    col--;
5217 #else
5218             col = aij->colmap[in[j]] - 1;
5219 #endif
5220             if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5221               ierr = DisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5222               col =  in[j];
5223               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5224               B = aij->B;
5225               b = (Mat_SeqAIJ*)B->data;
5226               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5227               rp2      = bj + bi[row];
5228               ap2      = ba + bi[row];
5229               rmax2    = bimax[row];
5230               nrow2    = bilen[row];
5231               low2     = 0;
5232               high2    = nrow2;
5233               bm       = aij->B->rmap->n;
5234               ba = b->a;
5235             }
5236           } else col = in[j];
5237           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
5238         }
5239       }
5240     } else {
5241       if (!aij->donotstash) {
5242         if (roworiented) {
5243           if (ignorezeroentries && v[i*n] == 0.0) continue;
5244           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n);CHKERRQ(ierr);
5245         } else {
5246           if (ignorezeroentries && v[i] == 0.0) continue;
5247           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m);CHKERRQ(ierr);
5248         }
5249       }
5250     }
5251   }}
5252   PetscFunctionReturnVoid();
5253 }
5254 EXTERN_C_END
5255 
5256