xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision db31f6defe33e3dfd9985704e6b8f54a7ffb6553)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>   /*I "petscmat.h" I*/
3 #include <petscblaslapack.h>
4 
5 /*MC
6    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
7 
8    This matrix type is identical to MATSEQAIJ when constructed with a single process communicator,
9    and MATMPIAIJ otherwise.  As a result, for single process communicators,
10   MatSeqAIJSetPreallocation is supported, and similarly MatMPIAIJSetPreallocation is supported
11   for communicators controlling multiple processes.  It is recommended that you call both of
12   the above preallocation routines for simplicity.
13 
14    Options Database Keys:
15 . -mat_type aij - sets the matrix type to "aij" during a call to MatSetFromOptions()
16 
17   Developer Notes: Subclasses include MATAIJCUSP, MATAIJPERM, MATAIJCRL, and also automatically switches over to use inodes when
18    enough exist.
19 
20   Level: beginner
21 
22 .seealso: MatCreateAIJ(), MatCreateSeqAIJ(), MATSEQAIJ,MATMPIAIJ
23 M*/
24 
25 /*MC
26    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
27 
28    This matrix type is identical to MATSEQAIJCRL when constructed with a single process communicator,
29    and MATMPIAIJCRL otherwise.  As a result, for single process communicators,
30    MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
31   for communicators controlling multiple processes.  It is recommended that you call both of
32   the above preallocation routines for simplicity.
33 
34    Options Database Keys:
35 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to MatSetFromOptions()
36 
37   Level: beginner
38 
39 .seealso: MatCreateMPIAIJCRL,MATSEQAIJCRL,MATMPIAIJCRL, MATSEQAIJCRL, MATMPIAIJCRL
40 M*/
41 
42 #undef __FUNCT__
43 #define __FUNCT__ "MatFindNonZeroRows_MPIAIJ"
44 PetscErrorCode MatFindNonZeroRows_MPIAIJ(Mat M,IS *keptrows)
45 {
46   PetscErrorCode  ierr;
47   Mat_MPIAIJ      *mat = (Mat_MPIAIJ*)M->data;
48   Mat_SeqAIJ      *a = (Mat_SeqAIJ*)mat->A->data;
49   Mat_SeqAIJ      *b = (Mat_SeqAIJ*)mat->B->data;
50   const PetscInt  *ia,*ib;
51   const MatScalar *aa,*bb;
52   PetscInt        na,nb,i,j,*rows,cnt=0,n0rows;
53   PetscInt        m = M->rmap->n,rstart = M->rmap->rstart;
54 
55   PetscFunctionBegin;
56   *keptrows = 0;
57   ia = a->i;
58   ib = b->i;
59   for (i=0; i<m; i++) {
60     na = ia[i+1] - ia[i];
61     nb = ib[i+1] - ib[i];
62     if (!na && !nb) {
63       cnt++;
64       goto ok1;
65     }
66     aa = a->a + ia[i];
67     for (j=0; j<na; j++) {
68       if (aa[j] != 0.0) goto ok1;
69     }
70     bb = b->a + ib[i];
71     for (j=0; j <nb; j++) {
72       if (bb[j] != 0.0) goto ok1;
73     }
74     cnt++;
75     ok1:;
76   }
77   ierr = MPI_Allreduce(&cnt,&n0rows,1,MPIU_INT,MPI_SUM,((PetscObject)M)->comm);CHKERRQ(ierr);
78   if (!n0rows) PetscFunctionReturn(0);
79   ierr = PetscMalloc((M->rmap->n-cnt)*sizeof(PetscInt),&rows);CHKERRQ(ierr);
80   cnt = 0;
81   for (i=0; i<m; i++) {
82     na = ia[i+1] - ia[i];
83     nb = ib[i+1] - ib[i];
84     if (!na && !nb) continue;
85     aa = a->a + ia[i];
86     for(j=0; j<na;j++) {
87       if (aa[j] != 0.0) {
88         rows[cnt++] = rstart + i;
89         goto ok2;
90       }
91     }
92     bb = b->a + ib[i];
93     for (j=0; j<nb; j++) {
94       if (bb[j] != 0.0) {
95         rows[cnt++] = rstart + i;
96         goto ok2;
97       }
98     }
99     ok2:;
100   }
101   ierr = ISCreateGeneral(((PetscObject)M)->comm,cnt,rows,PETSC_OWN_POINTER,keptrows);CHKERRQ(ierr);
102   PetscFunctionReturn(0);
103 }
104 
105 #undef __FUNCT__
106 #define __FUNCT__ "MatGetColumnNorms_MPIAIJ"
107 PetscErrorCode MatGetColumnNorms_MPIAIJ(Mat A,NormType type,PetscReal *norms)
108 {
109   PetscErrorCode ierr;
110   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)A->data;
111   PetscInt       i,n,*garray = aij->garray;
112   Mat_SeqAIJ     *a_aij = (Mat_SeqAIJ*) aij->A->data;
113   Mat_SeqAIJ     *b_aij = (Mat_SeqAIJ*) aij->B->data;
114   PetscReal      *work;
115 
116   PetscFunctionBegin;
117   ierr = MatGetSize(A,PETSC_NULL,&n);CHKERRQ(ierr);
118   ierr = PetscMalloc(n*sizeof(PetscReal),&work);CHKERRQ(ierr);
119   ierr = PetscMemzero(work,n*sizeof(PetscReal));CHKERRQ(ierr);
120   if (type == NORM_2) {
121     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
122       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]*a_aij->a[i]);
123     }
124     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
125       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]*b_aij->a[i]);
126     }
127   } else if (type == NORM_1) {
128     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
129       work[A->cmap->rstart + a_aij->j[i]] += PetscAbsScalar(a_aij->a[i]);
130     }
131     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
132       work[garray[b_aij->j[i]]] += PetscAbsScalar(b_aij->a[i]);
133     }
134   } else if (type == NORM_INFINITY) {
135     for (i=0; i<a_aij->i[aij->A->rmap->n]; i++) {
136       work[A->cmap->rstart + a_aij->j[i]] = PetscMax(PetscAbsScalar(a_aij->a[i]), work[A->cmap->rstart + a_aij->j[i]]);
137     }
138     for (i=0; i<b_aij->i[aij->B->rmap->n]; i++) {
139       work[garray[b_aij->j[i]]] = PetscMax(PetscAbsScalar(b_aij->a[i]),work[garray[b_aij->j[i]]]);
140     }
141 
142   } else SETERRQ(((PetscObject)A)->comm,PETSC_ERR_ARG_WRONG,"Unknown NormType");
143   if (type == NORM_INFINITY) {
144     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_MAX,A->hdr.comm);CHKERRQ(ierr);
145   } else {
146     ierr = MPI_Allreduce(work,norms,n,MPIU_REAL,MPIU_SUM,A->hdr.comm);CHKERRQ(ierr);
147   }
148   ierr = PetscFree(work);CHKERRQ(ierr);
149   if (type == NORM_2) {
150     for (i=0; i<n; i++) norms[i] = PetscSqrtReal(norms[i]);
151   }
152   PetscFunctionReturn(0);
153 }
154 
155 #undef __FUNCT__
156 #define __FUNCT__ "MatDistribute_MPIAIJ"
157 /*
158     Distributes a SeqAIJ matrix across a set of processes. Code stolen from
159     MatLoad_MPIAIJ(). Horrible lack of reuse. Should be a routine for each matrix type.
160 
161     Only for square matrices
162 */
163 PetscErrorCode MatDistribute_MPIAIJ(MPI_Comm comm,Mat gmat,PetscInt m,MatReuse reuse,Mat *inmat)
164 {
165   PetscMPIInt    rank,size;
166   PetscInt       *rowners,*dlens,*olens,i,rstart,rend,j,jj,nz,*gmataj,cnt,row,*ld;
167   PetscErrorCode ierr;
168   Mat            mat;
169   Mat_SeqAIJ     *gmata;
170   PetscMPIInt    tag;
171   MPI_Status     status;
172   PetscBool      aij;
173   MatScalar      *gmataa,*ao,*ad,*gmataarestore=0;
174 
175   PetscFunctionBegin;
176   CHKMEMQ;
177   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
178   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
179   if (!rank) {
180     ierr = PetscObjectTypeCompare((PetscObject)gmat,MATSEQAIJ,&aij);CHKERRQ(ierr);
181     if (!aij) SETERRQ1(((PetscObject)gmat)->comm,PETSC_ERR_SUP,"Currently no support for input matrix of type %s\n",((PetscObject)gmat)->type_name);
182   }
183   if (reuse == MAT_INITIAL_MATRIX) {
184     ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
185     ierr = MatSetSizes(mat,m,m,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
186     ierr = MatSetBlockSizes(mat,gmat->rmap->bs,gmat->cmap->bs);CHKERRQ(ierr);
187     ierr = MatSetType(mat,MATAIJ);CHKERRQ(ierr);
188     ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
189     ierr = PetscMalloc2(m,PetscInt,&dlens,m,PetscInt,&olens);CHKERRQ(ierr);
190     ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
191     rowners[0] = 0;
192     for (i=2; i<=size; i++) {
193       rowners[i] += rowners[i-1];
194     }
195     rstart = rowners[rank];
196     rend   = rowners[rank+1];
197     ierr   = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
198     if (!rank) {
199       gmata = (Mat_SeqAIJ*) gmat->data;
200       /* send row lengths to all processors */
201       for (i=0; i<m; i++) dlens[i] = gmata->ilen[i];
202       for (i=1; i<size; i++) {
203 	ierr = MPI_Send(gmata->ilen + rowners[i],rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
204       }
205       /* determine number diagonal and off-diagonal counts */
206       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
207       ierr = PetscMalloc(m*sizeof(PetscInt),&ld);CHKERRQ(ierr);
208       ierr = PetscMemzero(ld,m*sizeof(PetscInt));CHKERRQ(ierr);
209       jj = 0;
210       for (i=0; i<m; i++) {
211 	for (j=0; j<dlens[i]; j++) {
212           if (gmata->j[jj] < rstart) ld[i]++;
213 	  if (gmata->j[jj] < rstart || gmata->j[jj] >= rend) olens[i]++;
214 	  jj++;
215 	}
216       }
217       /* send column indices to other processes */
218       for (i=1; i<size; i++) {
219 	nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
220 	ierr = MPI_Send(&nz,1,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
221 	ierr = MPI_Send(gmata->j + gmata->i[rowners[i]],nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
222       }
223 
224       /* send numerical values to other processes */
225       for (i=1; i<size; i++) {
226         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
227         ierr = MPI_Send(gmata->a + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
228       }
229       gmataa = gmata->a;
230       gmataj = gmata->j;
231 
232     } else {
233       /* receive row lengths */
234       ierr = MPI_Recv(dlens,m,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
235       /* receive column indices */
236       ierr = MPI_Recv(&nz,1,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
237       ierr = PetscMalloc2(nz,PetscScalar,&gmataa,nz,PetscInt,&gmataj);CHKERRQ(ierr);
238       ierr = MPI_Recv(gmataj,nz,MPIU_INT,0,tag,comm,&status);CHKERRQ(ierr);
239       /* determine number diagonal and off-diagonal counts */
240       ierr = PetscMemzero(olens,m*sizeof(PetscInt));CHKERRQ(ierr);
241       ierr = PetscMalloc(m*sizeof(PetscInt),&ld);CHKERRQ(ierr);
242       ierr = PetscMemzero(ld,m*sizeof(PetscInt));CHKERRQ(ierr);
243       jj = 0;
244       for (i=0; i<m; i++) {
245 	for (j=0; j<dlens[i]; j++) {
246           if (gmataj[jj] < rstart) ld[i]++;
247 	  if (gmataj[jj] < rstart || gmataj[jj] >= rend) olens[i]++;
248 	  jj++;
249 	}
250       }
251       /* receive numerical values */
252       ierr = PetscMemzero(gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr);
253       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
254     }
255     /* set preallocation */
256     for (i=0; i<m; i++) {
257       dlens[i] -= olens[i];
258     }
259     ierr = MatSeqAIJSetPreallocation(mat,0,dlens);CHKERRQ(ierr);
260     ierr = MatMPIAIJSetPreallocation(mat,0,dlens,0,olens);CHKERRQ(ierr);
261 
262     for (i=0; i<m; i++) {
263       dlens[i] += olens[i];
264     }
265     cnt  = 0;
266     for (i=0; i<m; i++) {
267       row  = rstart + i;
268       ierr = MatSetValues(mat,1,&row,dlens[i],gmataj+cnt,gmataa+cnt,INSERT_VALUES);CHKERRQ(ierr);
269       cnt += dlens[i];
270     }
271     if (rank) {
272       ierr = PetscFree2(gmataa,gmataj);CHKERRQ(ierr);
273     }
274     ierr = PetscFree2(dlens,olens);CHKERRQ(ierr);
275     ierr = PetscFree(rowners);CHKERRQ(ierr);
276     ((Mat_MPIAIJ*)(mat->data))->ld = ld;
277     *inmat = mat;
278   } else {   /* column indices are already set; only need to move over numerical values from process 0 */
279     Mat_SeqAIJ *Ad = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->A->data;
280     Mat_SeqAIJ *Ao = (Mat_SeqAIJ*)((Mat_MPIAIJ*)((*inmat)->data))->B->data;
281     mat   = *inmat;
282     ierr  = PetscObjectGetNewTag((PetscObject)mat,&tag);CHKERRQ(ierr);
283     if (!rank) {
284       /* send numerical values to other processes */
285       gmata = (Mat_SeqAIJ*) gmat->data;
286       ierr   = MatGetOwnershipRanges(mat,(const PetscInt**)&rowners);CHKERRQ(ierr);
287       gmataa = gmata->a;
288       for (i=1; i<size; i++) {
289         nz   = gmata->i[rowners[i+1]]-gmata->i[rowners[i]];
290         ierr = MPI_Send(gmataa + gmata->i[rowners[i]],nz,MPIU_SCALAR,i,tag,comm);CHKERRQ(ierr);
291       }
292       nz   = gmata->i[rowners[1]]-gmata->i[rowners[0]];
293     } else {
294       /* receive numerical values from process 0*/
295       nz   = Ad->nz + Ao->nz;
296       ierr = PetscMalloc(nz*sizeof(PetscScalar),&gmataa);CHKERRQ(ierr); gmataarestore = gmataa;
297       ierr = MPI_Recv(gmataa,nz,MPIU_SCALAR,0,tag,comm,&status);CHKERRQ(ierr);
298     }
299     /* transfer numerical values into the diagonal A and off diagonal B parts of mat */
300     ld = ((Mat_MPIAIJ*)(mat->data))->ld;
301     ad = Ad->a;
302     ao = Ao->a;
303     if (mat->rmap->n) {
304       i  = 0;
305       nz = ld[i];                                   ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
306       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
307     }
308     for (i=1; i<mat->rmap->n; i++) {
309       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;
310       nz = Ad->i[i+1] - Ad->i[i];                   ierr = PetscMemcpy(ad,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ad += nz; gmataa += nz;
311     }
312     i--;
313     if (mat->rmap->n) {
314       nz = Ao->i[i+1] - Ao->i[i] - ld[i];           ierr = PetscMemcpy(ao,gmataa,nz*sizeof(PetscScalar));CHKERRQ(ierr); ao += nz; gmataa += nz;
315     }
316     if (rank) {
317       ierr = PetscFree(gmataarestore);CHKERRQ(ierr);
318     }
319   }
320   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
321   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
322   CHKMEMQ;
323   PetscFunctionReturn(0);
324 }
325 
326 /*
327   Local utility routine that creates a mapping from the global column
328 number to the local number in the off-diagonal part of the local
329 storage of the matrix.  When PETSC_USE_CTABLE is used this is scalable at
330 a slightly higher hash table cost; without it it is not scalable (each processor
331 has an order N integer array but is fast to acess.
332 */
333 #undef __FUNCT__
334 #define __FUNCT__ "MatCreateColmap_MPIAIJ_Private"
335 PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat mat)
336 {
337   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
338   PetscErrorCode ierr;
339   PetscInt       n = aij->B->cmap->n,i;
340 
341   PetscFunctionBegin;
342   if (!aij->garray) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPIAIJ Matrix was assembled but is missing garray");
343 #if defined (PETSC_USE_CTABLE)
344   ierr = PetscTableCreate(n,mat->cmap->N+1,&aij->colmap);CHKERRQ(ierr);
345   for (i=0; i<n; i++){
346     ierr = PetscTableAdd(aij->colmap,aij->garray[i]+1,i+1,INSERT_VALUES);CHKERRQ(ierr);
347   }
348 #else
349   ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscInt),&aij->colmap);CHKERRQ(ierr);
350   ierr = PetscLogObjectMemory(mat,mat->cmap->N*sizeof(PetscInt));CHKERRQ(ierr);
351   ierr = PetscMemzero(aij->colmap,mat->cmap->N*sizeof(PetscInt));CHKERRQ(ierr);
352   for (i=0; i<n; i++) aij->colmap[aij->garray[i]] = i+1;
353 #endif
354   PetscFunctionReturn(0);
355 }
356 
357 #define MatSetValues_SeqAIJ_A_Private(row,col,value,addv) \
358 { \
359     if (col <= lastcol1) low1 = 0; else high1 = nrow1; \
360     lastcol1 = col;\
361     while (high1-low1 > 5) { \
362       t = (low1+high1)/2; \
363       if (rp1[t] > col) high1 = t; \
364       else             low1  = t; \
365     } \
366       for (_i=low1; _i<high1; _i++) { \
367         if (rp1[_i] > col) break; \
368         if (rp1[_i] == col) { \
369           if (addv == ADD_VALUES) ap1[_i] += value;   \
370           else                    ap1[_i] = value; \
371           goto a_noinsert; \
372         } \
373       }  \
374       if (value == 0.0 && ignorezeroentries) {low1 = 0; high1 = nrow1;goto a_noinsert;} \
375       if (nonew == 1) {low1 = 0; high1 = nrow1; goto a_noinsert;}		\
376       if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
377       MatSeqXAIJReallocateAIJ(A,am,1,nrow1,row,col,rmax1,aa,ai,aj,rp1,ap1,aimax,nonew,MatScalar); \
378       N = nrow1++ - 1; a->nz++; high1++; \
379       /* shift up all the later entries in this row */ \
380       for (ii=N; ii>=_i; ii--) { \
381         rp1[ii+1] = rp1[ii]; \
382         ap1[ii+1] = ap1[ii]; \
383       } \
384       rp1[_i] = col;  \
385       ap1[_i] = value;  \
386       a_noinsert: ; \
387       ailen[row] = nrow1; \
388 }
389 
390 
391 #define MatSetValues_SeqAIJ_B_Private(row,col,value,addv) \
392 { \
393     if (col <= lastcol2) low2 = 0; else high2 = nrow2; \
394     lastcol2 = col;\
395     while (high2-low2 > 5) { \
396       t = (low2+high2)/2; \
397       if (rp2[t] > col) high2 = t; \
398       else             low2  = t; \
399     } \
400     for (_i=low2; _i<high2; _i++) {		\
401       if (rp2[_i] > col) break;			\
402       if (rp2[_i] == col) {			      \
403 	if (addv == ADD_VALUES) ap2[_i] += value;     \
404 	else                    ap2[_i] = value;      \
405 	goto b_noinsert;			      \
406       }						      \
407     }							      \
408     if (value == 0.0 && ignorezeroentries) {low2 = 0; high2 = nrow2; goto b_noinsert;} \
409     if (nonew == 1) {low2 = 0; high2 = nrow2; goto b_noinsert;}		\
410     if (nonew == -1) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Inserting a new nonzero (%D, %D) into matrix", row, col); \
411     MatSeqXAIJReallocateAIJ(B,bm,1,nrow2,row,col,rmax2,ba,bi,bj,rp2,ap2,bimax,nonew,MatScalar); \
412     N = nrow2++ - 1; b->nz++; high2++;					\
413     /* shift up all the later entries in this row */			\
414     for (ii=N; ii>=_i; ii--) {						\
415       rp2[ii+1] = rp2[ii];						\
416       ap2[ii+1] = ap2[ii];						\
417     }									\
418     rp2[_i] = col;							\
419     ap2[_i] = value;							\
420     b_noinsert: ;								\
421     bilen[row] = nrow2;							\
422 }
423 
424 #undef __FUNCT__
425 #define __FUNCT__ "MatSetValuesRow_MPIAIJ"
426 PetscErrorCode MatSetValuesRow_MPIAIJ(Mat A,PetscInt row,const PetscScalar v[])
427 {
428   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)A->data;
429   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)mat->A->data,*b = (Mat_SeqAIJ*)mat->B->data;
430   PetscErrorCode ierr;
431   PetscInt       l,*garray = mat->garray,diag;
432 
433   PetscFunctionBegin;
434   /* code only works for square matrices A */
435 
436   /* find size of row to the left of the diagonal part */
437   ierr = MatGetOwnershipRange(A,&diag,0);CHKERRQ(ierr);
438   row  = row - diag;
439   for (l=0; l<b->i[row+1]-b->i[row]; l++) {
440     if (garray[b->j[b->i[row]+l]] > diag) break;
441   }
442   ierr = PetscMemcpy(b->a+b->i[row],v,l*sizeof(PetscScalar));CHKERRQ(ierr);
443 
444   /* diagonal part */
445   ierr = PetscMemcpy(a->a+a->i[row],v+l,(a->i[row+1]-a->i[row])*sizeof(PetscScalar));CHKERRQ(ierr);
446 
447   /* right of diagonal part */
448   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);
449   PetscFunctionReturn(0);
450 }
451 
452 #undef __FUNCT__
453 #define __FUNCT__ "MatSetValues_MPIAIJ"
454 PetscErrorCode MatSetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt im[],PetscInt n,const PetscInt in[],const PetscScalar v[],InsertMode addv)
455 {
456   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
457   PetscScalar    value;
458   PetscErrorCode ierr;
459   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
460   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
461   PetscBool      roworiented = aij->roworiented;
462 
463   /* Some Variables required in the macro */
464   Mat            A = aij->A;
465   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
466   PetscInt       *aimax = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
467   MatScalar      *aa = a->a;
468   PetscBool      ignorezeroentries = a->ignorezeroentries;
469   Mat            B = aij->B;
470   Mat_SeqAIJ     *b = (Mat_SeqAIJ*)B->data;
471   PetscInt       *bimax = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
472   MatScalar      *ba = b->a;
473 
474   PetscInt       *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
475   PetscInt       nonew;
476   MatScalar      *ap1,*ap2;
477 
478   PetscFunctionBegin;
479   if (v) PetscValidScalarPointer(v,6);
480   for (i=0; i<m; i++) {
481     if (im[i] < 0) continue;
482 #if defined(PETSC_USE_DEBUG)
483     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
484 #endif
485     if (im[i] >= rstart && im[i] < rend) {
486       row      = im[i] - rstart;
487       lastcol1 = -1;
488       rp1      = aj + ai[row];
489       ap1      = aa + ai[row];
490       rmax1    = aimax[row];
491       nrow1    = ailen[row];
492       low1     = 0;
493       high1    = nrow1;
494       lastcol2 = -1;
495       rp2      = bj + bi[row];
496       ap2      = ba + bi[row];
497       rmax2    = bimax[row];
498       nrow2    = bilen[row];
499       low2     = 0;
500       high2    = nrow2;
501 
502       for (j=0; j<n; j++) {
503         if (v) {if (roworiented) value = v[i*n+j]; else value = v[i+j*m];} else value = 0.0;
504         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
505         if (in[j] >= cstart && in[j] < cend){
506           col = in[j] - cstart;
507           nonew = a->nonew;
508           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
509         } else if (in[j] < 0) continue;
510 #if defined(PETSC_USE_DEBUG)
511         else if (in[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);
512 #endif
513         else {
514           if (mat->was_assembled) {
515             if (!aij->colmap) {
516               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
517             }
518 #if defined (PETSC_USE_CTABLE)
519             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
520 	    col--;
521 #else
522             col = aij->colmap[in[j]] - 1;
523 #endif
524             if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
525               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
526               col =  in[j];
527               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
528               B = aij->B;
529               b = (Mat_SeqAIJ*)B->data;
530               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j; ba = b->a;
531               rp2      = bj + bi[row];
532               ap2      = ba + bi[row];
533               rmax2    = bimax[row];
534               nrow2    = bilen[row];
535               low2     = 0;
536               high2    = nrow2;
537               bm       = aij->B->rmap->n;
538               ba = b->a;
539             }
540           } else col = in[j];
541           nonew = b->nonew;
542           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
543         }
544       }
545     } else {
546       if (mat->nooffprocentries) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Setting off process row %D even though MatSetOption(,MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE) was set",im[i]);
547       if (!aij->donotstash) {
548         mat->assembled = PETSC_FALSE;
549         if (roworiented) {
550           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
551         } else {
552           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
553         }
554       }
555     }
556   }
557   PetscFunctionReturn(0);
558 }
559 
560 #undef __FUNCT__
561 #define __FUNCT__ "MatGetValues_MPIAIJ"
562 PetscErrorCode MatGetValues_MPIAIJ(Mat mat,PetscInt m,const PetscInt idxm[],PetscInt n,const PetscInt idxn[],PetscScalar v[])
563 {
564   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
565   PetscErrorCode ierr;
566   PetscInt       i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
567   PetscInt       cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
568 
569   PetscFunctionBegin;
570   for (i=0; i<m; i++) {
571     if (idxm[i] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative row: %D",idxm[i]);*/
572     if (idxm[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",idxm[i],mat->rmap->N-1);
573     if (idxm[i] >= rstart && idxm[i] < rend) {
574       row = idxm[i] - rstart;
575       for (j=0; j<n; j++) {
576         if (idxn[j] < 0) continue; /* SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative column: %D",idxn[j]); */
577         if (idxn[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",idxn[j],mat->cmap->N-1);
578         if (idxn[j] >= cstart && idxn[j] < cend){
579           col = idxn[j] - cstart;
580           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
581         } else {
582           if (!aij->colmap) {
583             ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
584           }
585 #if defined (PETSC_USE_CTABLE)
586           ierr = PetscTableFind(aij->colmap,idxn[j]+1,&col);CHKERRQ(ierr);
587           col --;
588 #else
589           col = aij->colmap[idxn[j]] - 1;
590 #endif
591           if ((col < 0) || (aij->garray[col] != idxn[j])) *(v+i*n+j) = 0.0;
592           else {
593             ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j);CHKERRQ(ierr);
594           }
595         }
596       }
597     } else {
598       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only local values currently supported");
599     }
600   }
601   PetscFunctionReturn(0);
602 }
603 
604 extern PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat,Vec,Vec);
605 
606 #undef __FUNCT__
607 #define __FUNCT__ "MatAssemblyBegin_MPIAIJ"
608 PetscErrorCode MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
609 {
610   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
611   PetscErrorCode ierr;
612   PetscInt       nstash,reallocs;
613   InsertMode     addv;
614 
615   PetscFunctionBegin;
616   if (aij->donotstash || mat->nooffprocentries) {
617     PetscFunctionReturn(0);
618   }
619 
620   /* make sure all processors are either in INSERTMODE or ADDMODE */
621   ierr = MPI_Allreduce(&mat->insertmode,&addv,1,MPI_INT,MPI_BOR,((PetscObject)mat)->comm);CHKERRQ(ierr);
622   if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
623   mat->insertmode = addv; /* in case this processor had no cache */
624 
625   ierr = MatStashScatterBegin_Private(mat,&mat->stash,mat->rmap->range);CHKERRQ(ierr);
626   ierr = MatStashGetInfo_Private(&mat->stash,&nstash,&reallocs);CHKERRQ(ierr);
627   ierr = PetscInfo2(aij->A,"Stash has %D entries, uses %D mallocs.\n",nstash,reallocs);CHKERRQ(ierr);
628   PetscFunctionReturn(0);
629 }
630 
631 #undef __FUNCT__
632 #define __FUNCT__ "MatAssemblyEnd_MPIAIJ"
633 PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
634 {
635   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
636   Mat_SeqAIJ     *a=(Mat_SeqAIJ *)aij->A->data;
637   PetscErrorCode ierr;
638   PetscMPIInt    n;
639   PetscInt       i,j,rstart,ncols,flg;
640   PetscInt       *row,*col;
641   PetscBool      other_disassembled;
642   PetscScalar    *val;
643   InsertMode     addv = mat->insertmode;
644 
645   /* do not use 'b = (Mat_SeqAIJ *)aij->B->data' as B can be reset in disassembly */
646   PetscFunctionBegin;
647   if (!aij->donotstash && !mat->nooffprocentries) {
648     while (1) {
649       ierr = MatStashScatterGetMesg_Private(&mat->stash,&n,&row,&col,&val,&flg);CHKERRQ(ierr);
650       if (!flg) break;
651 
652       for (i=0; i<n;) {
653         /* Now identify the consecutive vals belonging to the same row */
654         for (j=i,rstart=row[j]; j<n; j++) { if (row[j] != rstart) break; }
655         if (j < n) ncols = j-i;
656         else       ncols = n-i;
657         /* Now assemble all these values with a single function call */
658         ierr = MatSetValues_MPIAIJ(mat,1,row+i,ncols,col+i,val+i,addv);CHKERRQ(ierr);
659         i = j;
660       }
661     }
662     ierr = MatStashScatterEnd_Private(&mat->stash);CHKERRQ(ierr);
663   }
664   ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr);
665   ierr = MatAssemblyEnd(aij->A,mode);CHKERRQ(ierr);
666 
667   /* determine if any processor has disassembled, if so we must
668      also disassemble ourselfs, in order that we may reassemble. */
669   /*
670      if nonzero structure of submatrix B cannot change then we know that
671      no processor disassembled thus we can skip this stuff
672   */
673   if (!((Mat_SeqAIJ*)aij->B->data)->nonew)  {
674     ierr = MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPI_INT,MPI_PROD,((PetscObject)mat)->comm);CHKERRQ(ierr);
675     if (mat->was_assembled && !other_disassembled) {
676       ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
677     }
678   }
679   if (!mat->was_assembled && mode == MAT_FINAL_ASSEMBLY) {
680     ierr = MatSetUpMultiply_MPIAIJ(mat);CHKERRQ(ierr);
681   }
682   ierr = MatSetOption(aij->B,MAT_USE_INODES,PETSC_FALSE);CHKERRQ(ierr);
683   ierr = MatSetOption(aij->B,MAT_CHECK_COMPRESSED_ROW,PETSC_FALSE);CHKERRQ(ierr);
684   ierr = MatAssemblyBegin(aij->B,mode);CHKERRQ(ierr);
685   ierr = MatAssemblyEnd(aij->B,mode);CHKERRQ(ierr);
686 
687   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
688   aij->rowvalues = 0;
689 
690   /* used by MatAXPY() */
691   a->xtoy = 0; ((Mat_SeqAIJ *)aij->B->data)->xtoy = 0;  /* b->xtoy = 0 */
692   a->XtoY = 0; ((Mat_SeqAIJ *)aij->B->data)->XtoY = 0;  /* b->XtoY = 0 */
693 
694   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
695   if (a->inode.size) mat->ops->multdiagonalblock = MatMultDiagonalBlock_MPIAIJ;
696   PetscFunctionReturn(0);
697 }
698 
699 #undef __FUNCT__
700 #define __FUNCT__ "MatZeroEntries_MPIAIJ"
701 PetscErrorCode MatZeroEntries_MPIAIJ(Mat A)
702 {
703   Mat_MPIAIJ     *l = (Mat_MPIAIJ*)A->data;
704   PetscErrorCode ierr;
705 
706   PetscFunctionBegin;
707   ierr = MatZeroEntries(l->A);CHKERRQ(ierr);
708   ierr = MatZeroEntries(l->B);CHKERRQ(ierr);
709   PetscFunctionReturn(0);
710 }
711 
712 #undef __FUNCT__
713 #define __FUNCT__ "MatZeroRows_MPIAIJ"
714 PetscErrorCode MatZeroRows_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
715 {
716   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
717   PetscErrorCode    ierr;
718   PetscMPIInt       size = l->size,imdex,n,rank = l->rank,tag = ((PetscObject)A)->tag,lastidx = -1;
719   PetscInt          i,*owners = A->rmap->range;
720   PetscInt          *nprocs,j,idx,nsends,row;
721   PetscInt          nmax,*svalues,*starts,*owner,nrecvs;
722   PetscInt          *rvalues,count,base,slen,*source;
723   PetscInt          *lens,*lrows,*values,rstart=A->rmap->rstart;
724   MPI_Comm          comm = ((PetscObject)A)->comm;
725   MPI_Request       *send_waits,*recv_waits;
726   MPI_Status        recv_status,*send_status;
727   const PetscScalar *xx;
728   PetscScalar       *bb;
729 #if defined(PETSC_DEBUG)
730   PetscBool      found = PETSC_FALSE;
731 #endif
732 
733   PetscFunctionBegin;
734   /*  first count number of contributors to each processor */
735   ierr = PetscMalloc(2*size*sizeof(PetscInt),&nprocs);CHKERRQ(ierr);
736   ierr = PetscMemzero(nprocs,2*size*sizeof(PetscInt));CHKERRQ(ierr);
737   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&owner);CHKERRQ(ierr); /* see note*/
738   j = 0;
739   for (i=0; i<N; i++) {
740     if (lastidx > (idx = rows[i])) j = 0;
741     lastidx = idx;
742     for (; j<size; j++) {
743       if (idx >= owners[j] && idx < owners[j+1]) {
744         nprocs[2*j]++;
745         nprocs[2*j+1] = 1;
746         owner[i] = j;
747 #if defined(PETSC_DEBUG)
748         found = PETSC_TRUE;
749 #endif
750         break;
751       }
752     }
753 #if defined(PETSC_DEBUG)
754     if (!found) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index out of range");
755     found = PETSC_FALSE;
756 #endif
757   }
758   nsends = 0;  for (i=0; i<size; i++) { nsends += nprocs[2*i+1];}
759 
760   if (A->nooffproczerorows) {
761     if (nsends > 1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"You called MatSetOption(,MAT_NO_OFF_PROC_ZERO_ROWS,PETSC_TRUE) but set an off process zero row");
762     nrecvs = nsends;
763     nmax   = N;
764   } else {
765     /* inform other processors of number of messages and max length*/
766     ierr = PetscMaxSum(comm,nprocs,&nmax,&nrecvs);CHKERRQ(ierr);
767   }
768 
769   /* post receives:   */
770   ierr = PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(PetscInt),&rvalues);CHKERRQ(ierr);
771   ierr = PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);CHKERRQ(ierr);
772   for (i=0; i<nrecvs; i++) {
773     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPIU_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
774   }
775 
776   /* do sends:
777       1) starts[i] gives the starting index in svalues for stuff going to
778          the ith processor
779   */
780   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&svalues);CHKERRQ(ierr);
781   ierr = PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);CHKERRQ(ierr);
782   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&starts);CHKERRQ(ierr);
783   starts[0] = 0;
784   for (i=1; i<size; i++) { starts[i] = starts[i-1] + nprocs[2*i-2];}
785   for (i=0; i<N; i++) {
786     svalues[starts[owner[i]]++] = rows[i];
787   }
788 
789   starts[0] = 0;
790   for (i=1; i<size+1; i++) { starts[i] = starts[i-1] + nprocs[2*i-2];}
791   count = 0;
792   for (i=0; i<size; i++) {
793     if (nprocs[2*i+1]) {
794       ierr = MPI_Isend(svalues+starts[i],nprocs[2*i],MPIU_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
795     }
796   }
797   ierr = PetscFree(starts);CHKERRQ(ierr);
798 
799   base = owners[rank];
800 
801   /*  wait on receives */
802   ierr   = PetscMalloc2(nrecvs,PetscInt,&lens,nrecvs,PetscInt,&source);CHKERRQ(ierr);
803   count  = nrecvs; slen = 0;
804   while (count) {
805     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
806     /* unpack receives into our local space */
807     ierr = MPI_Get_count(&recv_status,MPIU_INT,&n);CHKERRQ(ierr);
808     source[imdex]  = recv_status.MPI_SOURCE;
809     lens[imdex]    = n;
810     slen          += n;
811     count--;
812   }
813   ierr = PetscFree(recv_waits);CHKERRQ(ierr);
814 
815   /* move the data into the send scatter */
816   ierr = PetscMalloc((slen+1)*sizeof(PetscInt),&lrows);CHKERRQ(ierr);
817   count = 0;
818   for (i=0; i<nrecvs; i++) {
819     values = rvalues + i*nmax;
820     for (j=0; j<lens[i]; j++) {
821       lrows[count++] = values[j] - base;
822     }
823   }
824   ierr = PetscFree(rvalues);CHKERRQ(ierr);
825   ierr = PetscFree2(lens,source);CHKERRQ(ierr);
826   ierr = PetscFree(owner);CHKERRQ(ierr);
827   ierr = PetscFree(nprocs);CHKERRQ(ierr);
828 
829   /* fix right hand side if needed */
830   if (x && b) {
831     ierr = VecGetArrayRead(x,&xx);CHKERRQ(ierr);
832     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
833     for (i=0; i<slen; i++) {
834       bb[lrows[i]] = diag*xx[lrows[i]];
835     }
836     ierr = VecRestoreArrayRead(x,&xx);CHKERRQ(ierr);
837     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
838   }
839   /*
840         Zero the required rows. If the "diagonal block" of the matrix
841      is square and the user wishes to set the diagonal we use separate
842      code so that MatSetValues() is not called for each diagonal allocating
843      new memory, thus calling lots of mallocs and slowing things down.
844 
845   */
846   /* must zero l->B before l->A because the (diag) case below may put values into l->B*/
847   ierr = MatZeroRows(l->B,slen,lrows,0.0,0,0);CHKERRQ(ierr);
848   if ((diag != 0.0) && (l->A->rmap->N == l->A->cmap->N)) {
849     ierr = MatZeroRows(l->A,slen,lrows,diag,0,0);CHKERRQ(ierr);
850   } else if (diag != 0.0) {
851     ierr = MatZeroRows(l->A,slen,lrows,0.0,0,0);CHKERRQ(ierr);
852     if (((Mat_SeqAIJ*)l->A->data)->nonew) {
853       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"MatZeroRows() on rectangular matrices cannot be used with the Mat options\n\
854 MAT_NEW_NONZERO_LOCATIONS,MAT_NEW_NONZERO_LOCATION_ERR,MAT_NEW_NONZERO_ALLOCATION_ERR");
855     }
856     for (i = 0; i < slen; i++) {
857       row  = lrows[i] + rstart;
858       ierr = MatSetValues(A,1,&row,1,&row,&diag,INSERT_VALUES);CHKERRQ(ierr);
859     }
860     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
861     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
862   } else {
863     ierr = MatZeroRows(l->A,slen,lrows,0.0,0,0);CHKERRQ(ierr);
864   }
865   ierr = PetscFree(lrows);CHKERRQ(ierr);
866 
867   /* wait on sends */
868   if (nsends) {
869     ierr = PetscMalloc(nsends*sizeof(MPI_Status),&send_status);CHKERRQ(ierr);
870     ierr = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
871     ierr = PetscFree(send_status);CHKERRQ(ierr);
872   }
873   ierr = PetscFree(send_waits);CHKERRQ(ierr);
874   ierr = PetscFree(svalues);CHKERRQ(ierr);
875   PetscFunctionReturn(0);
876 }
877 
878 #undef __FUNCT__
879 #define __FUNCT__ "MatZeroRowsColumns_MPIAIJ"
880 PetscErrorCode MatZeroRowsColumns_MPIAIJ(Mat A,PetscInt N,const PetscInt rows[],PetscScalar diag,Vec x,Vec b)
881 {
882   Mat_MPIAIJ        *l = (Mat_MPIAIJ*)A->data;
883   PetscErrorCode    ierr;
884   PetscMPIInt       size = l->size,imdex,n,rank = l->rank,tag = ((PetscObject)A)->tag,lastidx = -1;
885   PetscInt          i,*owners = A->rmap->range;
886   PetscInt          *nprocs,j,idx,nsends;
887   PetscInt          nmax,*svalues,*starts,*owner,nrecvs;
888   PetscInt          *rvalues,count,base,slen,*source;
889   PetscInt          *lens,*lrows,*values,m;
890   MPI_Comm          comm = ((PetscObject)A)->comm;
891   MPI_Request       *send_waits,*recv_waits;
892   MPI_Status        recv_status,*send_status;
893   const PetscScalar *xx;
894   PetscScalar       *bb,*mask;
895   Vec               xmask,lmask;
896   Mat_SeqAIJ        *aij = (Mat_SeqAIJ*)l->B->data;
897   const PetscInt    *aj, *ii,*ridx;
898   PetscScalar       *aa;
899 #if defined(PETSC_DEBUG)
900   PetscBool         found = PETSC_FALSE;
901 #endif
902 
903   PetscFunctionBegin;
904   /*  first count number of contributors to each processor */
905   ierr = PetscMalloc(2*size*sizeof(PetscInt),&nprocs);CHKERRQ(ierr);
906   ierr = PetscMemzero(nprocs,2*size*sizeof(PetscInt));CHKERRQ(ierr);
907   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&owner);CHKERRQ(ierr); /* see note*/
908   j = 0;
909   for (i=0; i<N; i++) {
910     if (lastidx > (idx = rows[i])) j = 0;
911     lastidx = idx;
912     for (; j<size; j++) {
913       if (idx >= owners[j] && idx < owners[j+1]) {
914         nprocs[2*j]++;
915         nprocs[2*j+1] = 1;
916         owner[i] = j;
917 #if defined(PETSC_DEBUG)
918         found = PETSC_TRUE;
919 #endif
920         break;
921       }
922     }
923 #if defined(PETSC_DEBUG)
924     if (!found) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index out of range");
925     found = PETSC_FALSE;
926 #endif
927   }
928   nsends = 0;  for (i=0; i<size; i++) { nsends += nprocs[2*i+1];}
929 
930   /* inform other processors of number of messages and max length*/
931   ierr = PetscMaxSum(comm,nprocs,&nmax,&nrecvs);CHKERRQ(ierr);
932 
933   /* post receives:   */
934   ierr = PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(PetscInt),&rvalues);CHKERRQ(ierr);
935   ierr = PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);CHKERRQ(ierr);
936   for (i=0; i<nrecvs; i++) {
937     ierr = MPI_Irecv(rvalues+nmax*i,nmax,MPIU_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);CHKERRQ(ierr);
938   }
939 
940   /* do sends:
941       1) starts[i] gives the starting index in svalues for stuff going to
942          the ith processor
943   */
944   ierr = PetscMalloc((N+1)*sizeof(PetscInt),&svalues);CHKERRQ(ierr);
945   ierr = PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);CHKERRQ(ierr);
946   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&starts);CHKERRQ(ierr);
947   starts[0] = 0;
948   for (i=1; i<size; i++) { starts[i] = starts[i-1] + nprocs[2*i-2];}
949   for (i=0; i<N; i++) {
950     svalues[starts[owner[i]]++] = rows[i];
951   }
952 
953   starts[0] = 0;
954   for (i=1; i<size+1; i++) { starts[i] = starts[i-1] + nprocs[2*i-2];}
955   count = 0;
956   for (i=0; i<size; i++) {
957     if (nprocs[2*i+1]) {
958       ierr = MPI_Isend(svalues+starts[i],nprocs[2*i],MPIU_INT,i,tag,comm,send_waits+count++);CHKERRQ(ierr);
959     }
960   }
961   ierr = PetscFree(starts);CHKERRQ(ierr);
962 
963   base = owners[rank];
964 
965   /*  wait on receives */
966   ierr   = PetscMalloc2(nrecvs,PetscInt,&lens,nrecvs,PetscInt,&source);CHKERRQ(ierr);
967   count  = nrecvs; slen = 0;
968   while (count) {
969     ierr = MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);CHKERRQ(ierr);
970     /* unpack receives into our local space */
971     ierr = MPI_Get_count(&recv_status,MPIU_INT,&n);CHKERRQ(ierr);
972     source[imdex]  = recv_status.MPI_SOURCE;
973     lens[imdex]    = n;
974     slen          += n;
975     count--;
976   }
977   ierr = PetscFree(recv_waits);CHKERRQ(ierr);
978 
979   /* move the data into the send scatter */
980   ierr = PetscMalloc((slen+1)*sizeof(PetscInt),&lrows);CHKERRQ(ierr);
981   count = 0;
982   for (i=0; i<nrecvs; i++) {
983     values = rvalues + i*nmax;
984     for (j=0; j<lens[i]; j++) {
985       lrows[count++] = values[j] - base;
986     }
987   }
988   ierr = PetscFree(rvalues);CHKERRQ(ierr);
989   ierr = PetscFree2(lens,source);CHKERRQ(ierr);
990   ierr = PetscFree(owner);CHKERRQ(ierr);
991   ierr = PetscFree(nprocs);CHKERRQ(ierr);
992   /* lrows are the local rows to be zeroed, slen is the number of local rows */
993 
994   /* zero diagonal part of matrix */
995   ierr = MatZeroRowsColumns(l->A,slen,lrows,diag,x,b);CHKERRQ(ierr);
996 
997   /* handle off diagonal part of matrix */
998   ierr = MatGetVecs(A,&xmask,PETSC_NULL);CHKERRQ(ierr);
999   ierr = VecDuplicate(l->lvec,&lmask);CHKERRQ(ierr);
1000   ierr = VecGetArray(xmask,&bb);CHKERRQ(ierr);
1001   for (i=0; i<slen; i++) {
1002     bb[lrows[i]] = 1;
1003   }
1004   ierr = VecRestoreArray(xmask,&bb);CHKERRQ(ierr);
1005   ierr = VecScatterBegin(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1006   ierr = VecScatterEnd(l->Mvctx,xmask,lmask,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1007   ierr = VecDestroy(&xmask);CHKERRQ(ierr);
1008   if (x) {
1009     ierr = VecScatterBegin(l->Mvctx,x,l->lvec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1010     ierr = VecScatterEnd(l->Mvctx,x,l->lvec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1011     ierr = VecGetArrayRead(l->lvec,&xx);CHKERRQ(ierr);
1012     ierr = VecGetArray(b,&bb);CHKERRQ(ierr);
1013   }
1014   ierr = VecGetArray(lmask,&mask);CHKERRQ(ierr);
1015 
1016   /* remove zeroed rows of off diagonal matrix */
1017   ii = aij->i;
1018   for (i=0; i<slen; i++) {
1019     ierr = PetscMemzero(aij->a + ii[lrows[i]],(ii[lrows[i]+1] - ii[lrows[i]])*sizeof(PetscScalar));CHKERRQ(ierr);
1020   }
1021 
1022   /* loop over all elements of off process part of matrix zeroing removed columns*/
1023   if (aij->compressedrow.use){
1024     m    = aij->compressedrow.nrows;
1025     ii   = aij->compressedrow.i;
1026     ridx = aij->compressedrow.rindex;
1027     for (i=0; i<m; i++){
1028       n   = ii[i+1] - ii[i];
1029       aj  = aij->j + ii[i];
1030       aa  = aij->a + ii[i];
1031 
1032       for (j=0; j<n; j++) {
1033         if (PetscAbsScalar(mask[*aj])) {
1034           if (b) bb[*ridx] -= *aa*xx[*aj];
1035           *aa        = 0.0;
1036         }
1037         aa++;
1038         aj++;
1039       }
1040       ridx++;
1041     }
1042   } else { /* do not use compressed row format */
1043     m = l->B->rmap->n;
1044     for (i=0; i<m; i++) {
1045       n   = ii[i+1] - ii[i];
1046       aj  = aij->j + ii[i];
1047       aa  = aij->a + ii[i];
1048       for (j=0; j<n; j++) {
1049         if (PetscAbsScalar(mask[*aj])) {
1050           if (b) bb[i] -= *aa*xx[*aj];
1051           *aa    = 0.0;
1052         }
1053         aa++;
1054         aj++;
1055       }
1056     }
1057   }
1058   if (x) {
1059     ierr = VecRestoreArray(b,&bb);CHKERRQ(ierr);
1060     ierr = VecRestoreArrayRead(l->lvec,&xx);CHKERRQ(ierr);
1061   }
1062   ierr = VecRestoreArray(lmask,&mask);CHKERRQ(ierr);
1063   ierr = VecDestroy(&lmask);CHKERRQ(ierr);
1064   ierr = PetscFree(lrows);CHKERRQ(ierr);
1065 
1066   /* wait on sends */
1067   if (nsends) {
1068     ierr = PetscMalloc(nsends*sizeof(MPI_Status),&send_status);CHKERRQ(ierr);
1069     ierr = MPI_Waitall(nsends,send_waits,send_status);CHKERRQ(ierr);
1070     ierr = PetscFree(send_status);CHKERRQ(ierr);
1071   }
1072   ierr = PetscFree(send_waits);CHKERRQ(ierr);
1073   ierr = PetscFree(svalues);CHKERRQ(ierr);
1074 
1075   PetscFunctionReturn(0);
1076 }
1077 
1078 #undef __FUNCT__
1079 #define __FUNCT__ "MatMult_MPIAIJ"
1080 PetscErrorCode MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
1081 {
1082   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1083   PetscErrorCode ierr;
1084   PetscInt       nt;
1085 
1086   PetscFunctionBegin;
1087   ierr = VecGetLocalSize(xx,&nt);CHKERRQ(ierr);
1088   if (nt != A->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Incompatible partition of A (%D) and xx (%D)",A->cmap->n,nt);
1089   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1090   ierr = (*a->A->ops->mult)(a->A,xx,yy);CHKERRQ(ierr);
1091   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1092   ierr = (*a->B->ops->multadd)(a->B,a->lvec,yy,yy);CHKERRQ(ierr);
1093   PetscFunctionReturn(0);
1094 }
1095 
1096 #undef __FUNCT__
1097 #define __FUNCT__ "MatMultDiagonalBlock_MPIAIJ"
1098 PetscErrorCode MatMultDiagonalBlock_MPIAIJ(Mat A,Vec bb,Vec xx)
1099 {
1100   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1101   PetscErrorCode ierr;
1102 
1103   PetscFunctionBegin;
1104   ierr = MatMultDiagonalBlock(a->A,bb,xx);CHKERRQ(ierr);
1105   PetscFunctionReturn(0);
1106 }
1107 
1108 #undef __FUNCT__
1109 #define __FUNCT__ "MatMultAdd_MPIAIJ"
1110 PetscErrorCode MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1111 {
1112   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1113   PetscErrorCode ierr;
1114 
1115   PetscFunctionBegin;
1116   ierr = VecScatterBegin(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1117   ierr = (*a->A->ops->multadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1118   ierr = VecScatterEnd(a->Mvctx,xx,a->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1119   ierr = (*a->B->ops->multadd)(a->B,a->lvec,zz,zz);CHKERRQ(ierr);
1120   PetscFunctionReturn(0);
1121 }
1122 
1123 #undef __FUNCT__
1124 #define __FUNCT__ "MatMultTranspose_MPIAIJ"
1125 PetscErrorCode MatMultTranspose_MPIAIJ(Mat A,Vec xx,Vec yy)
1126 {
1127   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1128   PetscErrorCode ierr;
1129   PetscBool      merged;
1130 
1131   PetscFunctionBegin;
1132   ierr = VecScatterGetMerged(a->Mvctx,&merged);CHKERRQ(ierr);
1133   /* do nondiagonal part */
1134   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1135   if (!merged) {
1136     /* send it on its way */
1137     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1138     /* do local part */
1139     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1140     /* receive remote parts: note this assumes the values are not actually */
1141     /* added in yy until the next line, */
1142     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1143   } else {
1144     /* do local part */
1145     ierr = (*a->A->ops->multtranspose)(a->A,xx,yy);CHKERRQ(ierr);
1146     /* send it on its way */
1147     ierr = VecScatterBegin(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1148     /* values actually were received in the Begin() but we need to call this nop */
1149     ierr = VecScatterEnd(a->Mvctx,a->lvec,yy,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1150   }
1151   PetscFunctionReturn(0);
1152 }
1153 
1154 EXTERN_C_BEGIN
1155 #undef __FUNCT__
1156 #define __FUNCT__ "MatIsTranspose_MPIAIJ"
1157 PetscErrorCode  MatIsTranspose_MPIAIJ(Mat Amat,Mat Bmat,PetscReal tol,PetscBool  *f)
1158 {
1159   MPI_Comm       comm;
1160   Mat_MPIAIJ     *Aij = (Mat_MPIAIJ *) Amat->data, *Bij;
1161   Mat            Adia = Aij->A, Bdia, Aoff,Boff,*Aoffs,*Boffs;
1162   IS             Me,Notme;
1163   PetscErrorCode ierr;
1164   PetscInt       M,N,first,last,*notme,i;
1165   PetscMPIInt    size;
1166 
1167   PetscFunctionBegin;
1168 
1169   /* Easy test: symmetric diagonal block */
1170   Bij = (Mat_MPIAIJ *) Bmat->data; Bdia = Bij->A;
1171   ierr = MatIsTranspose(Adia,Bdia,tol,f);CHKERRQ(ierr);
1172   if (!*f) PetscFunctionReturn(0);
1173   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1174   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1175   if (size == 1) PetscFunctionReturn(0);
1176 
1177   /* Hard test: off-diagonal block. This takes a MatGetSubMatrix. */
1178   ierr = MatGetSize(Amat,&M,&N);CHKERRQ(ierr);
1179   ierr = MatGetOwnershipRange(Amat,&first,&last);CHKERRQ(ierr);
1180   ierr = PetscMalloc((N-last+first)*sizeof(PetscInt),&notme);CHKERRQ(ierr);
1181   for (i=0; i<first; i++) notme[i] = i;
1182   for (i=last; i<M; i++) notme[i-last+first] = i;
1183   ierr = ISCreateGeneral(MPI_COMM_SELF,N-last+first,notme,PETSC_COPY_VALUES,&Notme);CHKERRQ(ierr);
1184   ierr = ISCreateStride(MPI_COMM_SELF,last-first,first,1,&Me);CHKERRQ(ierr);
1185   ierr = MatGetSubMatrices(Amat,1,&Me,&Notme,MAT_INITIAL_MATRIX,&Aoffs);CHKERRQ(ierr);
1186   Aoff = Aoffs[0];
1187   ierr = MatGetSubMatrices(Bmat,1,&Notme,&Me,MAT_INITIAL_MATRIX,&Boffs);CHKERRQ(ierr);
1188   Boff = Boffs[0];
1189   ierr = MatIsTranspose(Aoff,Boff,tol,f);CHKERRQ(ierr);
1190   ierr = MatDestroyMatrices(1,&Aoffs);CHKERRQ(ierr);
1191   ierr = MatDestroyMatrices(1,&Boffs);CHKERRQ(ierr);
1192   ierr = ISDestroy(&Me);CHKERRQ(ierr);
1193   ierr = ISDestroy(&Notme);CHKERRQ(ierr);
1194   ierr = PetscFree(notme);CHKERRQ(ierr);
1195    PetscFunctionReturn(0);
1196 }
1197 EXTERN_C_END
1198 
1199 #undef __FUNCT__
1200 #define __FUNCT__ "MatMultTransposeAdd_MPIAIJ"
1201 PetscErrorCode MatMultTransposeAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
1202 {
1203   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1204   PetscErrorCode ierr;
1205 
1206   PetscFunctionBegin;
1207   /* do nondiagonal part */
1208   ierr = (*a->B->ops->multtranspose)(a->B,xx,a->lvec);CHKERRQ(ierr);
1209   /* send it on its way */
1210   ierr = VecScatterBegin(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1211   /* do local part */
1212   ierr = (*a->A->ops->multtransposeadd)(a->A,xx,yy,zz);CHKERRQ(ierr);
1213   /* receive remote parts */
1214   ierr = VecScatterEnd(a->Mvctx,a->lvec,zz,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1215   PetscFunctionReturn(0);
1216 }
1217 
1218 /*
1219   This only works correctly for square matrices where the subblock A->A is the
1220    diagonal block
1221 */
1222 #undef __FUNCT__
1223 #define __FUNCT__ "MatGetDiagonal_MPIAIJ"
1224 PetscErrorCode MatGetDiagonal_MPIAIJ(Mat A,Vec v)
1225 {
1226   PetscErrorCode ierr;
1227   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1228 
1229   PetscFunctionBegin;
1230   if (A->rmap->N != A->cmap->N) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_SUP,"Supports only square matrix where A->A is diag block");
1231   if (A->rmap->rstart != A->cmap->rstart || A->rmap->rend != A->cmap->rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"row partition must equal col partition");
1232   ierr = MatGetDiagonal(a->A,v);CHKERRQ(ierr);
1233   PetscFunctionReturn(0);
1234 }
1235 
1236 #undef __FUNCT__
1237 #define __FUNCT__ "MatScale_MPIAIJ"
1238 PetscErrorCode MatScale_MPIAIJ(Mat A,PetscScalar aa)
1239 {
1240   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1241   PetscErrorCode ierr;
1242 
1243   PetscFunctionBegin;
1244   ierr = MatScale(a->A,aa);CHKERRQ(ierr);
1245   ierr = MatScale(a->B,aa);CHKERRQ(ierr);
1246   PetscFunctionReturn(0);
1247 }
1248 
1249 #undef __FUNCT__
1250 #define __FUNCT__ "MatDestroy_MPIAIJ"
1251 PetscErrorCode MatDestroy_MPIAIJ(Mat mat)
1252 {
1253   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1254   PetscErrorCode ierr;
1255 
1256   PetscFunctionBegin;
1257 #if defined(PETSC_USE_LOG)
1258   PetscLogObjectState((PetscObject)mat,"Rows=%D, Cols=%D",mat->rmap->N,mat->cmap->N);
1259 #endif
1260   ierr = MatStashDestroy_Private(&mat->stash);CHKERRQ(ierr);
1261   ierr = VecDestroy(&aij->diag);CHKERRQ(ierr);
1262   ierr = MatDestroy(&aij->A);CHKERRQ(ierr);
1263   ierr = MatDestroy(&aij->B);CHKERRQ(ierr);
1264 #if defined (PETSC_USE_CTABLE)
1265   ierr = PetscTableDestroy(&aij->colmap);CHKERRQ(ierr);
1266 #else
1267   ierr = PetscFree(aij->colmap);CHKERRQ(ierr);
1268 #endif
1269   ierr = PetscFree(aij->garray);CHKERRQ(ierr);
1270   ierr = VecDestroy(&aij->lvec);CHKERRQ(ierr);
1271   ierr = VecScatterDestroy(&aij->Mvctx);CHKERRQ(ierr);
1272   ierr = PetscFree2(aij->rowvalues,aij->rowindices);CHKERRQ(ierr);
1273   ierr = PetscFree(aij->ld);CHKERRQ(ierr);
1274   ierr = PetscFree(mat->data);CHKERRQ(ierr);
1275 
1276   ierr = PetscObjectChangeTypeName((PetscObject)mat,0);CHKERRQ(ierr);
1277   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatStoreValues_C","",PETSC_NULL);CHKERRQ(ierr);
1278   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatRetrieveValues_C","",PETSC_NULL);CHKERRQ(ierr);
1279   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatGetDiagonalBlock_C","",PETSC_NULL);CHKERRQ(ierr);
1280   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatIsTranspose_C","",PETSC_NULL);CHKERRQ(ierr);
1281   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocation_C","",PETSC_NULL);CHKERRQ(ierr);
1282   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatMPIAIJSetPreallocationCSR_C","",PETSC_NULL);CHKERRQ(ierr);
1283   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatDiagonalScaleLocal_C","",PETSC_NULL);CHKERRQ(ierr);
1284   ierr = PetscObjectComposeFunction((PetscObject)mat,"MatConvert_mpiaij_mpisbaij_C","",PETSC_NULL);CHKERRQ(ierr);
1285   PetscFunctionReturn(0);
1286 }
1287 
1288 #undef __FUNCT__
1289 #define __FUNCT__ "MatView_MPIAIJ_Binary"
1290 PetscErrorCode MatView_MPIAIJ_Binary(Mat mat,PetscViewer viewer)
1291 {
1292   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1293   Mat_SeqAIJ*       A = (Mat_SeqAIJ*)aij->A->data;
1294   Mat_SeqAIJ*       B = (Mat_SeqAIJ*)aij->B->data;
1295   PetscErrorCode    ierr;
1296   PetscMPIInt       rank,size,tag = ((PetscObject)viewer)->tag;
1297   int               fd;
1298   PetscInt          nz,header[4],*row_lengths,*range=0,rlen,i;
1299   PetscInt          nzmax,*column_indices,j,k,col,*garray = aij->garray,cnt,cstart = mat->cmap->rstart,rnz;
1300   PetscScalar       *column_values;
1301   PetscInt          message_count,flowcontrolcount;
1302 
1303   PetscFunctionBegin;
1304   ierr = MPI_Comm_rank(((PetscObject)mat)->comm,&rank);CHKERRQ(ierr);
1305   ierr = MPI_Comm_size(((PetscObject)mat)->comm,&size);CHKERRQ(ierr);
1306   nz   = A->nz + B->nz;
1307   if (!rank) {
1308     header[0] = MAT_FILE_CLASSID;
1309     header[1] = mat->rmap->N;
1310     header[2] = mat->cmap->N;
1311     ierr = MPI_Reduce(&nz,&header[3],1,MPIU_INT,MPI_SUM,0,((PetscObject)mat)->comm);CHKERRQ(ierr);
1312     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
1313     ierr = PetscBinaryWrite(fd,header,4,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1314     /* get largest number of rows any processor has */
1315     rlen = mat->rmap->n;
1316     range = mat->rmap->range;
1317     for (i=1; i<size; i++) {
1318       rlen = PetscMax(rlen,range[i+1] - range[i]);
1319     }
1320   } else {
1321     ierr = MPI_Reduce(&nz,0,1,MPIU_INT,MPI_SUM,0,((PetscObject)mat)->comm);CHKERRQ(ierr);
1322     rlen = mat->rmap->n;
1323   }
1324 
1325   /* load up the local row counts */
1326   ierr = PetscMalloc((rlen+1)*sizeof(PetscInt),&row_lengths);CHKERRQ(ierr);
1327   for (i=0; i<mat->rmap->n; i++) {
1328     row_lengths[i] = A->i[i+1] - A->i[i] + B->i[i+1] - B->i[i];
1329   }
1330 
1331   /* store the row lengths to the file */
1332   ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1333   if (!rank) {
1334     ierr = PetscBinaryWrite(fd,row_lengths,mat->rmap->n,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1335     for (i=1; i<size; i++) {
1336       ierr = PetscViewerFlowControlStepMaster(viewer,i,message_count,flowcontrolcount);CHKERRQ(ierr);
1337       rlen = range[i+1] - range[i];
1338       ierr = MPIULong_Recv(row_lengths,rlen,MPIU_INT,i,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1339       ierr = PetscBinaryWrite(fd,row_lengths,rlen,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1340     }
1341     ierr = PetscViewerFlowControlEndMaster(viewer,message_count);CHKERRQ(ierr);
1342   } else {
1343     ierr = PetscViewerFlowControlStepWorker(viewer,rank,message_count);CHKERRQ(ierr);
1344     ierr = MPIULong_Send(row_lengths,mat->rmap->n,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1345     ierr = PetscViewerFlowControlEndWorker(viewer,message_count);CHKERRQ(ierr);
1346   }
1347   ierr = PetscFree(row_lengths);CHKERRQ(ierr);
1348 
1349   /* load up the local column indices */
1350   nzmax = nz; /* )th processor needs space a largest processor needs */
1351   ierr = MPI_Reduce(&nz,&nzmax,1,MPIU_INT,MPI_MAX,0,((PetscObject)mat)->comm);CHKERRQ(ierr);
1352   ierr = PetscMalloc((nzmax+1)*sizeof(PetscInt),&column_indices);CHKERRQ(ierr);
1353   cnt  = 0;
1354   for (i=0; i<mat->rmap->n; i++) {
1355     for (j=B->i[i]; j<B->i[i+1]; j++) {
1356       if ( (col = garray[B->j[j]]) > cstart) break;
1357       column_indices[cnt++] = col;
1358     }
1359     for (k=A->i[i]; k<A->i[i+1]; k++) {
1360       column_indices[cnt++] = A->j[k] + cstart;
1361     }
1362     for (; j<B->i[i+1]; j++) {
1363       column_indices[cnt++] = garray[B->j[j]];
1364     }
1365   }
1366   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1367 
1368   /* store the column indices to the file */
1369    ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1370   if (!rank) {
1371     MPI_Status status;
1372     ierr = PetscBinaryWrite(fd,column_indices,nz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1373     for (i=1; i<size; i++) {
1374       ierr = PetscViewerFlowControlStepMaster(viewer,i,message_count,flowcontrolcount);CHKERRQ(ierr);
1375       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
1376       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1377       ierr = MPIULong_Recv(column_indices,rnz,MPIU_INT,i,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1378       ierr = PetscBinaryWrite(fd,column_indices,rnz,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
1379     }
1380      ierr = PetscViewerFlowControlEndMaster(viewer,message_count);CHKERRQ(ierr);
1381   } else {
1382     ierr = PetscViewerFlowControlStepWorker(viewer,rank,message_count);CHKERRQ(ierr);
1383     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1384     ierr = MPIULong_Send(column_indices,nz,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1385     ierr = PetscViewerFlowControlEndWorker(viewer,message_count);CHKERRQ(ierr);
1386   }
1387   ierr = PetscFree(column_indices);CHKERRQ(ierr);
1388 
1389   /* load up the local column values */
1390   ierr = PetscMalloc((nzmax+1)*sizeof(PetscScalar),&column_values);CHKERRQ(ierr);
1391   cnt  = 0;
1392   for (i=0; i<mat->rmap->n; i++) {
1393     for (j=B->i[i]; j<B->i[i+1]; j++) {
1394       if ( garray[B->j[j]] > cstart) break;
1395       column_values[cnt++] = B->a[j];
1396     }
1397     for (k=A->i[i]; k<A->i[i+1]; k++) {
1398       column_values[cnt++] = A->a[k];
1399     }
1400     for (; j<B->i[i+1]; j++) {
1401       column_values[cnt++] = B->a[j];
1402     }
1403   }
1404   if (cnt != A->nz + B->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal PETSc error: cnt = %D nz = %D",cnt,A->nz+B->nz);
1405 
1406   /* store the column values to the file */
1407    ierr = PetscViewerFlowControlStart(viewer,&message_count,&flowcontrolcount);CHKERRQ(ierr);
1408   if (!rank) {
1409     MPI_Status status;
1410     ierr = PetscBinaryWrite(fd,column_values,nz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1411     for (i=1; i<size; i++) {
1412        ierr = PetscViewerFlowControlStepMaster(viewer,i,message_count,flowcontrolcount);CHKERRQ(ierr);
1413       ierr = MPI_Recv(&rnz,1,MPIU_INT,i,tag,((PetscObject)mat)->comm,&status);CHKERRQ(ierr);
1414       if (rnz > nzmax) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Internal PETSc error: nz = %D nzmax = %D",nz,nzmax);
1415       ierr = MPIULong_Recv(column_values,rnz,MPIU_SCALAR,i,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1416       ierr = PetscBinaryWrite(fd,column_values,rnz,PETSC_SCALAR,PETSC_TRUE);CHKERRQ(ierr);
1417     }
1418     ierr = PetscViewerFlowControlEndMaster(viewer,message_count);CHKERRQ(ierr);
1419   } else {
1420     ierr = PetscViewerFlowControlStepWorker(viewer,rank,message_count);CHKERRQ(ierr);
1421     ierr = MPI_Send(&nz,1,MPIU_INT,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1422     ierr = MPIULong_Send(column_values,nz,MPIU_SCALAR,0,tag,((PetscObject)mat)->comm);CHKERRQ(ierr);
1423     ierr = PetscViewerFlowControlEndWorker(viewer,message_count);CHKERRQ(ierr);
1424   }
1425   ierr = PetscFree(column_values);CHKERRQ(ierr);
1426   PetscFunctionReturn(0);
1427 }
1428 
1429 #undef __FUNCT__
1430 #define __FUNCT__ "MatView_MPIAIJ_ASCIIorDraworSocket"
1431 PetscErrorCode MatView_MPIAIJ_ASCIIorDraworSocket(Mat mat,PetscViewer viewer)
1432 {
1433   Mat_MPIAIJ        *aij = (Mat_MPIAIJ*)mat->data;
1434   PetscErrorCode    ierr;
1435   PetscMPIInt       rank = aij->rank,size = aij->size;
1436   PetscBool         isdraw,iascii,isbinary;
1437   PetscViewer       sviewer;
1438   PetscViewerFormat format;
1439 
1440   PetscFunctionBegin;
1441   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1442   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1443   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1444   if (iascii) {
1445     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
1446     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1447       MatInfo    info;
1448       PetscBool  inodes;
1449 
1450       ierr = MPI_Comm_rank(((PetscObject)mat)->comm,&rank);CHKERRQ(ierr);
1451       ierr = MatGetInfo(mat,MAT_LOCAL,&info);CHKERRQ(ierr);
1452       ierr = MatInodeGetInodeSizes(aij->A,PETSC_NULL,(PetscInt **)&inodes,PETSC_NULL);CHKERRQ(ierr);
1453       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr);
1454       if (!inodes) {
1455         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, not using I-node routines\n",
1456 					      rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1457       } else {
1458         ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] Local rows %D nz %D nz alloced %D mem %D, using I-node routines\n",
1459 		    rank,mat->rmap->n,(PetscInt)info.nz_used,(PetscInt)info.nz_allocated,(PetscInt)info.memory);CHKERRQ(ierr);
1460       }
1461       ierr = MatGetInfo(aij->A,MAT_LOCAL,&info);CHKERRQ(ierr);
1462       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] on-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1463       ierr = MatGetInfo(aij->B,MAT_LOCAL,&info);CHKERRQ(ierr);
1464       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d] off-diagonal part: nz %D \n",rank,(PetscInt)info.nz_used);CHKERRQ(ierr);
1465       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
1466       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr);
1467       ierr = PetscViewerASCIIPrintf(viewer,"Information on VecScatter used in matrix-vector product: \n");CHKERRQ(ierr);
1468       ierr = VecScatterView(aij->Mvctx,viewer);CHKERRQ(ierr);
1469       PetscFunctionReturn(0);
1470     } else if (format == PETSC_VIEWER_ASCII_INFO) {
1471       PetscInt   inodecount,inodelimit,*inodes;
1472       ierr = MatInodeGetInodeSizes(aij->A,&inodecount,&inodes,&inodelimit);CHKERRQ(ierr);
1473       if (inodes) {
1474         ierr = PetscViewerASCIIPrintf(viewer,"using I-node (on process 0) routines: found %D nodes, limit used is %D\n",inodecount,inodelimit);CHKERRQ(ierr);
1475       } else {
1476         ierr = PetscViewerASCIIPrintf(viewer,"not using I-node (on process 0) routines\n");CHKERRQ(ierr);
1477       }
1478       PetscFunctionReturn(0);
1479     } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1480       PetscFunctionReturn(0);
1481     }
1482   } else if (isbinary) {
1483     if (size == 1) {
1484       ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1485       ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1486     } else {
1487       ierr = MatView_MPIAIJ_Binary(mat,viewer);CHKERRQ(ierr);
1488     }
1489     PetscFunctionReturn(0);
1490   } else if (isdraw) {
1491     PetscDraw  draw;
1492     PetscBool  isnull;
1493     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1494     ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
1495   }
1496 
1497   if (size == 1) {
1498     ierr = PetscObjectSetName((PetscObject)aij->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1499     ierr = MatView(aij->A,viewer);CHKERRQ(ierr);
1500   } else {
1501     /* assemble the entire matrix onto first processor. */
1502     Mat         A;
1503     Mat_SeqAIJ  *Aloc;
1504     PetscInt    M = mat->rmap->N,N = mat->cmap->N,m,*ai,*aj,row,*cols,i,*ct;
1505     MatScalar   *a;
1506 
1507     if (mat->rmap->N > 1024) {
1508       PetscBool  flg = PETSC_FALSE;
1509 
1510       ierr = PetscOptionsGetBool(((PetscObject) mat)->prefix, "-mat_ascii_output_large", &flg,PETSC_NULL);CHKERRQ(ierr);
1511       if (!flg) {
1512         SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_OUTOFRANGE,"ASCII matrix output not allowed for matrices with more than 1024 rows, use binary format instead.\nYou can override this restriction using -mat_ascii_output_large.");
1513       }
1514     }
1515 
1516     ierr = MatCreate(((PetscObject)mat)->comm,&A);CHKERRQ(ierr);
1517     if (!rank) {
1518       ierr = MatSetSizes(A,M,N,M,N);CHKERRQ(ierr);
1519     } else {
1520       ierr = MatSetSizes(A,0,0,M,N);CHKERRQ(ierr);
1521     }
1522     /* This is just a temporary matrix, so explicitly using MATMPIAIJ is probably best */
1523     ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
1524     ierr = MatMPIAIJSetPreallocation(A,0,PETSC_NULL,0,PETSC_NULL);CHKERRQ(ierr);
1525     ierr = MatSetOption(A,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
1526     ierr = PetscLogObjectParent(mat,A);CHKERRQ(ierr);
1527 
1528     /* copy over the A part */
1529     Aloc = (Mat_SeqAIJ*)aij->A->data;
1530     m = aij->A->rmap->n; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1531     row = mat->rmap->rstart;
1532     for (i=0; i<ai[m]; i++) {aj[i] += mat->cmap->rstart ;}
1533     for (i=0; i<m; i++) {
1534       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
1535       row++; a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1536     }
1537     aj = Aloc->j;
1538     for (i=0; i<ai[m]; i++) {aj[i] -= mat->cmap->rstart;}
1539 
1540     /* copy over the B part */
1541     Aloc = (Mat_SeqAIJ*)aij->B->data;
1542     m    = aij->B->rmap->n;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
1543     row  = mat->rmap->rstart;
1544     ierr = PetscMalloc((ai[m]+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
1545     ct   = cols;
1546     for (i=0; i<ai[m]; i++) {cols[i] = aij->garray[aj[i]];}
1547     for (i=0; i<m; i++) {
1548       ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
1549       row++; a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1550     }
1551     ierr = PetscFree(ct);CHKERRQ(ierr);
1552     ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1553     ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1554     /*
1555        Everyone has to call to draw the matrix since the graphics waits are
1556        synchronized across all processors that share the PetscDraw object
1557     */
1558     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
1559     if (!rank) {
1560       ierr = PetscObjectSetName((PetscObject)((Mat_MPIAIJ*)(A->data))->A,((PetscObject)mat)->name);CHKERRQ(ierr);
1561       /* Set the type name to MATMPIAIJ so that the correct type can be printed out by PetscObjectPrintClassNamePrefixType() in MatView_SeqAIJ_ASCII()*/
1562       PetscStrcpy(((PetscObject)((Mat_MPIAIJ*)(A->data))->A)->type_name,MATMPIAIJ);
1563       ierr = MatView(((Mat_MPIAIJ*)(A->data))->A,sviewer);CHKERRQ(ierr);
1564     }
1565     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
1566     ierr = MatDestroy(&A);CHKERRQ(ierr);
1567   }
1568   PetscFunctionReturn(0);
1569 }
1570 
1571 #undef __FUNCT__
1572 #define __FUNCT__ "MatView_MPIAIJ"
1573 PetscErrorCode MatView_MPIAIJ(Mat mat,PetscViewer viewer)
1574 {
1575   PetscErrorCode ierr;
1576   PetscBool      iascii,isdraw,issocket,isbinary;
1577 
1578   PetscFunctionBegin;
1579   ierr  = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1580   ierr  = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1581   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1582   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSOCKET,&issocket);CHKERRQ(ierr);
1583   if (iascii || isdraw || isbinary || issocket) {
1584     ierr = MatView_MPIAIJ_ASCIIorDraworSocket(mat,viewer);CHKERRQ(ierr);
1585   } else {
1586     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported by MPIAIJ matrices",((PetscObject)viewer)->type_name);
1587   }
1588   PetscFunctionReturn(0);
1589 }
1590 
1591 #undef __FUNCT__
1592 #define __FUNCT__ "MatSOR_MPIAIJ"
1593 PetscErrorCode MatSOR_MPIAIJ(Mat matin,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
1594 {
1595   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1596   PetscErrorCode ierr;
1597   Vec            bb1 = 0;
1598   PetscBool      hasop;
1599 
1600   PetscFunctionBegin;
1601   if (its > 1 || ~flag & SOR_ZERO_INITIAL_GUESS || flag & SOR_EISENSTAT) {
1602     ierr = VecDuplicate(bb,&bb1);CHKERRQ(ierr);
1603   }
1604 
1605   if (flag == SOR_APPLY_UPPER) {
1606     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1607     PetscFunctionReturn(0);
1608   }
1609 
1610   if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP){
1611     if (flag & SOR_ZERO_INITIAL_GUESS) {
1612       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1613       its--;
1614     }
1615 
1616     while (its--) {
1617       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1618       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1619 
1620       /* update rhs: bb1 = bb - B*x */
1621       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1622       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1623 
1624       /* local sweep */
1625       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_SYMMETRIC_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1626     }
1627   } else if (flag & SOR_LOCAL_FORWARD_SWEEP){
1628     if (flag & SOR_ZERO_INITIAL_GUESS) {
1629       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1630       its--;
1631     }
1632     while (its--) {
1633       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1634       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1635 
1636       /* update rhs: bb1 = bb - B*x */
1637       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1638       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1639 
1640       /* local sweep */
1641       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_FORWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1642     }
1643   } else if (flag & SOR_LOCAL_BACKWARD_SWEEP){
1644     if (flag & SOR_ZERO_INITIAL_GUESS) {
1645       ierr = (*mat->A->ops->sor)(mat->A,bb,omega,flag,fshift,lits,1,xx);CHKERRQ(ierr);
1646       its--;
1647     }
1648     while (its--) {
1649       ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1650       ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1651 
1652       /* update rhs: bb1 = bb - B*x */
1653       ierr = VecScale(mat->lvec,-1.0);CHKERRQ(ierr);
1654       ierr = (*mat->B->ops->multadd)(mat->B,mat->lvec,bb,bb1);CHKERRQ(ierr);
1655 
1656       /* local sweep */
1657       ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,SOR_BACKWARD_SWEEP,fshift,lits,1,xx);CHKERRQ(ierr);
1658     }
1659   }  else if (flag & SOR_EISENSTAT) {
1660     Vec         xx1;
1661 
1662     ierr = VecDuplicate(bb,&xx1);CHKERRQ(ierr);
1663     ierr = (*mat->A->ops->sor)(mat->A,bb,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_BACKWARD_SWEEP),fshift,lits,1,xx);CHKERRQ(ierr);
1664 
1665     ierr = VecScatterBegin(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1666     ierr = VecScatterEnd(mat->Mvctx,xx,mat->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1667     if (!mat->diag) {
1668       ierr = MatGetVecs(matin,&mat->diag,PETSC_NULL);CHKERRQ(ierr);
1669       ierr = MatGetDiagonal(matin,mat->diag);CHKERRQ(ierr);
1670     }
1671     ierr = MatHasOperation(matin,MATOP_MULT_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr);
1672     if (hasop) {
1673       ierr = MatMultDiagonalBlock(matin,xx,bb1);CHKERRQ(ierr);
1674     } else {
1675       ierr = VecPointwiseMult(bb1,mat->diag,xx);CHKERRQ(ierr);
1676     }
1677     ierr = VecAYPX(bb1,(omega-2.0)/omega,bb);CHKERRQ(ierr);
1678 
1679     ierr = MatMultAdd(mat->B,mat->lvec,bb1,bb1);CHKERRQ(ierr);
1680 
1681     /* local sweep */
1682     ierr = (*mat->A->ops->sor)(mat->A,bb1,omega,(MatSORType)(SOR_ZERO_INITIAL_GUESS | SOR_LOCAL_FORWARD_SWEEP),fshift,lits,1,xx1);CHKERRQ(ierr);
1683     ierr = VecAXPY(xx,1.0,xx1);CHKERRQ(ierr);
1684     ierr = VecDestroy(&xx1);CHKERRQ(ierr);
1685   } else SETERRQ(((PetscObject)matin)->comm,PETSC_ERR_SUP,"Parallel SOR not supported");
1686 
1687   ierr = VecDestroy(&bb1);CHKERRQ(ierr);
1688   PetscFunctionReturn(0);
1689 }
1690 
1691 #undef __FUNCT__
1692 #define __FUNCT__ "MatPermute_MPIAIJ"
1693 PetscErrorCode MatPermute_MPIAIJ(Mat A,IS rowp,IS colp,Mat *B)
1694 {
1695   MPI_Comm       comm;
1696   PetscInt       first,local_rowsize,local_colsize;
1697   const PetscInt *rows;
1698   IS             crowp,growp,irowp,lrowp,lcolp,icolp;
1699   PetscErrorCode ierr;
1700 
1701   PetscFunctionBegin;
1702   ierr = PetscObjectGetComm((PetscObject)A,&comm);CHKERRQ(ierr);
1703   /* make a collective version of 'rowp', this is to be tolerant of users who pass serial index sets */
1704   ierr = ISOnComm(rowp,comm,PETSC_USE_POINTER,&crowp);CHKERRQ(ierr);
1705   /* collect the global row permutation and invert it */
1706   ierr = ISAllGather(crowp,&growp);CHKERRQ(ierr);
1707   ierr = ISSetPermutation(growp);CHKERRQ(ierr);
1708   ierr = ISDestroy(&crowp);CHKERRQ(ierr);
1709   ierr = ISInvertPermutation(growp,PETSC_DECIDE,&irowp);CHKERRQ(ierr);
1710   ierr = ISDestroy(&growp);CHKERRQ(ierr);
1711   /* get the local target indices */
1712   ierr = MatGetOwnershipRange(A,&first,PETSC_NULL);CHKERRQ(ierr);
1713   ierr = MatGetLocalSize(A,&local_rowsize,&local_colsize);CHKERRQ(ierr);
1714   ierr = ISGetIndices(irowp,&rows);CHKERRQ(ierr);
1715   ierr = ISCreateGeneral(PETSC_COMM_SELF,local_rowsize,rows+first,PETSC_COPY_VALUES,&lrowp);CHKERRQ(ierr);
1716   ierr = ISRestoreIndices(irowp,&rows);CHKERRQ(ierr);
1717   ierr = ISDestroy(&irowp);CHKERRQ(ierr);
1718   /* the column permutation is so much easier;
1719      make a local version of 'colp' and invert it */
1720   ierr = ISOnComm(colp,PETSC_COMM_SELF,PETSC_USE_POINTER,&lcolp);CHKERRQ(ierr);
1721   ierr = ISSetPermutation(lcolp);CHKERRQ(ierr);
1722   ierr = ISInvertPermutation(lcolp,PETSC_DECIDE,&icolp);CHKERRQ(ierr);
1723   ierr = ISDestroy(&lcolp);CHKERRQ(ierr);
1724   /* now we just get the submatrix */
1725   ierr = MatGetSubMatrix_MPIAIJ_Private(A,lrowp,icolp,local_colsize,MAT_INITIAL_MATRIX,B);CHKERRQ(ierr);
1726   /* clean up */
1727   ierr = ISDestroy(&lrowp);CHKERRQ(ierr);
1728   ierr = ISDestroy(&icolp);CHKERRQ(ierr);
1729   PetscFunctionReturn(0);
1730 }
1731 
1732 #undef __FUNCT__
1733 #define __FUNCT__ "MatGetInfo_MPIAIJ"
1734 PetscErrorCode MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,MatInfo *info)
1735 {
1736   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1737   Mat            A = mat->A,B = mat->B;
1738   PetscErrorCode ierr;
1739   PetscReal      isend[5],irecv[5];
1740 
1741   PetscFunctionBegin;
1742   info->block_size     = 1.0;
1743   ierr = MatGetInfo(A,MAT_LOCAL,info);CHKERRQ(ierr);
1744   isend[0] = info->nz_used; isend[1] = info->nz_allocated; isend[2] = info->nz_unneeded;
1745   isend[3] = info->memory;  isend[4] = info->mallocs;
1746   ierr = MatGetInfo(B,MAT_LOCAL,info);CHKERRQ(ierr);
1747   isend[0] += info->nz_used; isend[1] += info->nz_allocated; isend[2] += info->nz_unneeded;
1748   isend[3] += info->memory;  isend[4] += info->mallocs;
1749   if (flag == MAT_LOCAL) {
1750     info->nz_used      = isend[0];
1751     info->nz_allocated = isend[1];
1752     info->nz_unneeded  = isend[2];
1753     info->memory       = isend[3];
1754     info->mallocs      = isend[4];
1755   } else if (flag == MAT_GLOBAL_MAX) {
1756     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,((PetscObject)matin)->comm);CHKERRQ(ierr);
1757     info->nz_used      = irecv[0];
1758     info->nz_allocated = irecv[1];
1759     info->nz_unneeded  = irecv[2];
1760     info->memory       = irecv[3];
1761     info->mallocs      = irecv[4];
1762   } else if (flag == MAT_GLOBAL_SUM) {
1763     ierr = MPI_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_SUM,((PetscObject)matin)->comm);CHKERRQ(ierr);
1764     info->nz_used      = irecv[0];
1765     info->nz_allocated = irecv[1];
1766     info->nz_unneeded  = irecv[2];
1767     info->memory       = irecv[3];
1768     info->mallocs      = irecv[4];
1769   }
1770   info->fill_ratio_given  = 0; /* no parallel LU/ILU/Cholesky */
1771   info->fill_ratio_needed = 0;
1772   info->factor_mallocs    = 0;
1773 
1774   PetscFunctionReturn(0);
1775 }
1776 
1777 #undef __FUNCT__
1778 #define __FUNCT__ "MatSetOption_MPIAIJ"
1779 PetscErrorCode MatSetOption_MPIAIJ(Mat A,MatOption op,PetscBool  flg)
1780 {
1781   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
1782   PetscErrorCode ierr;
1783 
1784   PetscFunctionBegin;
1785   switch (op) {
1786   case MAT_NEW_NONZERO_LOCATIONS:
1787   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1788   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1789   case MAT_KEEP_NONZERO_PATTERN:
1790   case MAT_NEW_NONZERO_LOCATION_ERR:
1791   case MAT_USE_INODES:
1792   case MAT_IGNORE_ZERO_ENTRIES:
1793     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1794     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1795     break;
1796   case MAT_ROW_ORIENTED:
1797     a->roworiented = flg;
1798     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1799     ierr = MatSetOption(a->B,op,flg);CHKERRQ(ierr);
1800     break;
1801   case MAT_NEW_DIAGONALS:
1802     ierr = PetscInfo1(A,"Option %s ignored\n",MatOptions[op]);CHKERRQ(ierr);
1803     break;
1804   case MAT_IGNORE_OFF_PROC_ENTRIES:
1805     a->donotstash = flg;
1806     break;
1807   case MAT_SPD:
1808     A->spd_set                         = PETSC_TRUE;
1809     A->spd                             = flg;
1810     if (flg) {
1811       A->symmetric                     = PETSC_TRUE;
1812       A->structurally_symmetric        = PETSC_TRUE;
1813       A->symmetric_set                 = PETSC_TRUE;
1814       A->structurally_symmetric_set    = PETSC_TRUE;
1815     }
1816     break;
1817   case MAT_SYMMETRIC:
1818     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1819     break;
1820   case MAT_STRUCTURALLY_SYMMETRIC:
1821     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1822     break;
1823   case MAT_HERMITIAN:
1824     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1825     break;
1826   case MAT_SYMMETRY_ETERNAL:
1827     ierr = MatSetOption(a->A,op,flg);CHKERRQ(ierr);
1828     break;
1829   default:
1830     SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"unknown option %d",op);
1831   }
1832   PetscFunctionReturn(0);
1833 }
1834 
1835 #undef __FUNCT__
1836 #define __FUNCT__ "MatGetRow_MPIAIJ"
1837 PetscErrorCode MatGetRow_MPIAIJ(Mat matin,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1838 {
1839   Mat_MPIAIJ     *mat = (Mat_MPIAIJ*)matin->data;
1840   PetscScalar    *vworkA,*vworkB,**pvA,**pvB,*v_p;
1841   PetscErrorCode ierr;
1842   PetscInt       i,*cworkA,*cworkB,**pcA,**pcB,cstart = matin->cmap->rstart;
1843   PetscInt       nztot,nzA,nzB,lrow,rstart = matin->rmap->rstart,rend = matin->rmap->rend;
1844   PetscInt       *cmap,*idx_p;
1845 
1846   PetscFunctionBegin;
1847   if (mat->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Already active");
1848   mat->getrowactive = PETSC_TRUE;
1849 
1850   if (!mat->rowvalues && (idx || v)) {
1851     /*
1852         allocate enough space to hold information from the longest row.
1853     */
1854     Mat_SeqAIJ *Aa = (Mat_SeqAIJ*)mat->A->data,*Ba = (Mat_SeqAIJ*)mat->B->data;
1855     PetscInt   max = 1,tmp;
1856     for (i=0; i<matin->rmap->n; i++) {
1857       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1858       if (max < tmp) { max = tmp; }
1859     }
1860     ierr = PetscMalloc2(max,PetscScalar,&mat->rowvalues,max,PetscInt,&mat->rowindices);CHKERRQ(ierr);
1861   }
1862 
1863   if (row < rstart || row >= rend) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only local rows");
1864   lrow = row - rstart;
1865 
1866   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1867   if (!v)   {pvA = 0; pvB = 0;}
1868   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1869   ierr = (*mat->A->ops->getrow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1870   ierr = (*mat->B->ops->getrow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1871   nztot = nzA + nzB;
1872 
1873   cmap  = mat->garray;
1874   if (v  || idx) {
1875     if (nztot) {
1876       /* Sort by increasing column numbers, assuming A and B already sorted */
1877       PetscInt imark = -1;
1878       if (v) {
1879         *v = v_p = mat->rowvalues;
1880         for (i=0; i<nzB; i++) {
1881           if (cmap[cworkB[i]] < cstart)   v_p[i] = vworkB[i];
1882           else break;
1883         }
1884         imark = i;
1885         for (i=0; i<nzA; i++)     v_p[imark+i] = vworkA[i];
1886         for (i=imark; i<nzB; i++) v_p[nzA+i]   = vworkB[i];
1887       }
1888       if (idx) {
1889         *idx = idx_p = mat->rowindices;
1890         if (imark > -1) {
1891           for (i=0; i<imark; i++) {
1892             idx_p[i] = cmap[cworkB[i]];
1893           }
1894         } else {
1895           for (i=0; i<nzB; i++) {
1896             if (cmap[cworkB[i]] < cstart)   idx_p[i] = cmap[cworkB[i]];
1897             else break;
1898           }
1899           imark = i;
1900         }
1901         for (i=0; i<nzA; i++)     idx_p[imark+i] = cstart + cworkA[i];
1902         for (i=imark; i<nzB; i++) idx_p[nzA+i]   = cmap[cworkB[i]];
1903       }
1904     } else {
1905       if (idx) *idx = 0;
1906       if (v)   *v   = 0;
1907     }
1908   }
1909   *nz = nztot;
1910   ierr = (*mat->A->ops->restorerow)(mat->A,lrow,&nzA,pcA,pvA);CHKERRQ(ierr);
1911   ierr = (*mat->B->ops->restorerow)(mat->B,lrow,&nzB,pcB,pvB);CHKERRQ(ierr);
1912   PetscFunctionReturn(0);
1913 }
1914 
1915 #undef __FUNCT__
1916 #define __FUNCT__ "MatRestoreRow_MPIAIJ"
1917 PetscErrorCode MatRestoreRow_MPIAIJ(Mat mat,PetscInt row,PetscInt *nz,PetscInt **idx,PetscScalar **v)
1918 {
1919   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
1920 
1921   PetscFunctionBegin;
1922   if (!aij->getrowactive) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"MatGetRow() must be called first");
1923   aij->getrowactive = PETSC_FALSE;
1924   PetscFunctionReturn(0);
1925 }
1926 
1927 #undef __FUNCT__
1928 #define __FUNCT__ "MatNorm_MPIAIJ"
1929 PetscErrorCode MatNorm_MPIAIJ(Mat mat,NormType type,PetscReal *norm)
1930 {
1931   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
1932   Mat_SeqAIJ     *amat = (Mat_SeqAIJ*)aij->A->data,*bmat = (Mat_SeqAIJ*)aij->B->data;
1933   PetscErrorCode ierr;
1934   PetscInt       i,j,cstart = mat->cmap->rstart;
1935   PetscReal      sum = 0.0;
1936   MatScalar      *v;
1937 
1938   PetscFunctionBegin;
1939   if (aij->size == 1) {
1940     ierr =  MatNorm(aij->A,type,norm);CHKERRQ(ierr);
1941   } else {
1942     if (type == NORM_FROBENIUS) {
1943       v = amat->a;
1944       for (i=0; i<amat->nz; i++) {
1945 #if defined(PETSC_USE_COMPLEX)
1946         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1947 #else
1948         sum += (*v)*(*v); v++;
1949 #endif
1950       }
1951       v = bmat->a;
1952       for (i=0; i<bmat->nz; i++) {
1953 #if defined(PETSC_USE_COMPLEX)
1954         sum += PetscRealPart(PetscConj(*v)*(*v)); v++;
1955 #else
1956         sum += (*v)*(*v); v++;
1957 #endif
1958       }
1959       ierr = MPI_Allreduce(&sum,norm,1,MPIU_REAL,MPIU_SUM,((PetscObject)mat)->comm);CHKERRQ(ierr);
1960       *norm = PetscSqrtReal(*norm);
1961     } else if (type == NORM_1) { /* max column norm */
1962       PetscReal *tmp,*tmp2;
1963       PetscInt  *jj,*garray = aij->garray;
1964       ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp);CHKERRQ(ierr);
1965       ierr = PetscMalloc((mat->cmap->N+1)*sizeof(PetscReal),&tmp2);CHKERRQ(ierr);
1966       ierr = PetscMemzero(tmp,mat->cmap->N*sizeof(PetscReal));CHKERRQ(ierr);
1967       *norm = 0.0;
1968       v = amat->a; jj = amat->j;
1969       for (j=0; j<amat->nz; j++) {
1970         tmp[cstart + *jj++ ] += PetscAbsScalar(*v);  v++;
1971       }
1972       v = bmat->a; jj = bmat->j;
1973       for (j=0; j<bmat->nz; j++) {
1974         tmp[garray[*jj++]] += PetscAbsScalar(*v); v++;
1975       }
1976       ierr = MPI_Allreduce(tmp,tmp2,mat->cmap->N,MPIU_REAL,MPIU_SUM,((PetscObject)mat)->comm);CHKERRQ(ierr);
1977       for (j=0; j<mat->cmap->N; j++) {
1978         if (tmp2[j] > *norm) *norm = tmp2[j];
1979       }
1980       ierr = PetscFree(tmp);CHKERRQ(ierr);
1981       ierr = PetscFree(tmp2);CHKERRQ(ierr);
1982     } else if (type == NORM_INFINITY) { /* max row norm */
1983       PetscReal ntemp = 0.0;
1984       for (j=0; j<aij->A->rmap->n; j++) {
1985         v = amat->a + amat->i[j];
1986         sum = 0.0;
1987         for (i=0; i<amat->i[j+1]-amat->i[j]; i++) {
1988           sum += PetscAbsScalar(*v); v++;
1989         }
1990         v = bmat->a + bmat->i[j];
1991         for (i=0; i<bmat->i[j+1]-bmat->i[j]; i++) {
1992           sum += PetscAbsScalar(*v); v++;
1993         }
1994         if (sum > ntemp) ntemp = sum;
1995       }
1996       ierr = MPI_Allreduce(&ntemp,norm,1,MPIU_REAL,MPIU_MAX,((PetscObject)mat)->comm);CHKERRQ(ierr);
1997     } else {
1998       SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_SUP,"No support for two norm");
1999     }
2000   }
2001   PetscFunctionReturn(0);
2002 }
2003 
2004 #undef __FUNCT__
2005 #define __FUNCT__ "MatTranspose_MPIAIJ"
2006 PetscErrorCode MatTranspose_MPIAIJ(Mat A,MatReuse reuse,Mat *matout)
2007 {
2008   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2009   Mat_SeqAIJ     *Aloc=(Mat_SeqAIJ*)a->A->data,*Bloc=(Mat_SeqAIJ*)a->B->data;
2010   PetscErrorCode ierr;
2011   PetscInt       M = A->rmap->N,N = A->cmap->N,ma,na,mb,*ai,*aj,*bi,*bj,row,*cols,*cols_tmp,i,*d_nnz;
2012   PetscInt       cstart=A->cmap->rstart,ncol;
2013   Mat            B;
2014   MatScalar      *array;
2015 
2016   PetscFunctionBegin;
2017   if (reuse == MAT_REUSE_MATRIX && A == *matout && M != N) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_ARG_SIZ,"Square matrix only for in-place");
2018 
2019   ma = A->rmap->n; na = A->cmap->n; mb = a->B->rmap->n;
2020   ai = Aloc->i; aj = Aloc->j;
2021   bi = Bloc->i; bj = Bloc->j;
2022   if (reuse == MAT_INITIAL_MATRIX || *matout == A) {
2023     /* compute d_nnz for preallocation; o_nnz is approximated by d_nnz to avoid communication */
2024     ierr = PetscMalloc((1+na)*sizeof(PetscInt),&d_nnz);CHKERRQ(ierr);
2025     ierr = PetscMemzero(d_nnz,(1+na)*sizeof(PetscInt));CHKERRQ(ierr);
2026     for (i=0; i<ai[ma]; i++){
2027       d_nnz[aj[i]] ++;
2028       aj[i] += cstart; /* global col index to be used by MatSetValues() */
2029     }
2030 
2031     ierr = MatCreate(((PetscObject)A)->comm,&B);CHKERRQ(ierr);
2032     ierr = MatSetSizes(B,A->cmap->n,A->rmap->n,N,M);CHKERRQ(ierr);
2033     ierr = MatSetBlockSizes(B,A->cmap->bs,A->rmap->bs); CHKERRQ(ierr);
2034     ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
2035     ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,d_nnz);CHKERRQ(ierr);
2036     ierr = MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
2037     ierr = PetscFree(d_nnz);CHKERRQ(ierr);
2038   } else {
2039     B = *matout;
2040   }
2041 
2042   /* copy over the A part */
2043   array = Aloc->a;
2044   row = A->rmap->rstart;
2045   for (i=0; i<ma; i++) {
2046     ncol = ai[i+1]-ai[i];
2047     ierr = MatSetValues(B,ncol,aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2048     row++; array += ncol; aj += ncol;
2049   }
2050   aj = Aloc->j;
2051   for (i=0; i<ai[ma]; i++) aj[i] -= cstart; /* resume local col index */
2052 
2053   /* copy over the B part */
2054   ierr = PetscMalloc(bi[mb]*sizeof(PetscInt),&cols);CHKERRQ(ierr);
2055   ierr = PetscMemzero(cols,bi[mb]*sizeof(PetscInt));CHKERRQ(ierr);
2056   array = Bloc->a;
2057   row = A->rmap->rstart;
2058   for (i=0; i<bi[mb]; i++) {cols[i] = a->garray[bj[i]];}
2059   cols_tmp = cols;
2060   for (i=0; i<mb; i++) {
2061     ncol = bi[i+1]-bi[i];
2062     ierr = MatSetValues(B,ncol,cols_tmp,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
2063     row++; array += ncol; cols_tmp += ncol;
2064   }
2065   ierr = PetscFree(cols);CHKERRQ(ierr);
2066 
2067   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2068   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2069   if (reuse == MAT_INITIAL_MATRIX || *matout != A) {
2070     *matout = B;
2071   } else {
2072     ierr = MatHeaderMerge(A,B);CHKERRQ(ierr);
2073   }
2074   PetscFunctionReturn(0);
2075 }
2076 
2077 #undef __FUNCT__
2078 #define __FUNCT__ "MatDiagonalScale_MPIAIJ"
2079 PetscErrorCode MatDiagonalScale_MPIAIJ(Mat mat,Vec ll,Vec rr)
2080 {
2081   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2082   Mat            a = aij->A,b = aij->B;
2083   PetscErrorCode ierr;
2084   PetscInt       s1,s2,s3;
2085 
2086   PetscFunctionBegin;
2087   ierr = MatGetLocalSize(mat,&s2,&s3);CHKERRQ(ierr);
2088   if (rr) {
2089     ierr = VecGetLocalSize(rr,&s1);CHKERRQ(ierr);
2090     if (s1!=s3) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"right vector non-conforming local size");
2091     /* Overlap communication with computation. */
2092     ierr = VecScatterBegin(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2093   }
2094   if (ll) {
2095     ierr = VecGetLocalSize(ll,&s1);CHKERRQ(ierr);
2096     if (s1!=s2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"left vector non-conforming local size");
2097     ierr = (*b->ops->diagonalscale)(b,ll,0);CHKERRQ(ierr);
2098   }
2099   /* scale  the diagonal block */
2100   ierr = (*a->ops->diagonalscale)(a,ll,rr);CHKERRQ(ierr);
2101 
2102   if (rr) {
2103     /* Do a scatter end and then right scale the off-diagonal block */
2104     ierr = VecScatterEnd(aij->Mvctx,rr,aij->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2105     ierr = (*b->ops->diagonalscale)(b,0,aij->lvec);CHKERRQ(ierr);
2106   }
2107 
2108   PetscFunctionReturn(0);
2109 }
2110 
2111 #undef __FUNCT__
2112 #define __FUNCT__ "MatSetUnfactored_MPIAIJ"
2113 PetscErrorCode MatSetUnfactored_MPIAIJ(Mat A)
2114 {
2115   Mat_MPIAIJ     *a   = (Mat_MPIAIJ*)A->data;
2116   PetscErrorCode ierr;
2117 
2118   PetscFunctionBegin;
2119   ierr = MatSetUnfactored(a->A);CHKERRQ(ierr);
2120   PetscFunctionReturn(0);
2121 }
2122 
2123 #undef __FUNCT__
2124 #define __FUNCT__ "MatEqual_MPIAIJ"
2125 PetscErrorCode MatEqual_MPIAIJ(Mat A,Mat B,PetscBool  *flag)
2126 {
2127   Mat_MPIAIJ     *matB = (Mat_MPIAIJ*)B->data,*matA = (Mat_MPIAIJ*)A->data;
2128   Mat            a,b,c,d;
2129   PetscBool      flg;
2130   PetscErrorCode ierr;
2131 
2132   PetscFunctionBegin;
2133   a = matA->A; b = matA->B;
2134   c = matB->A; d = matB->B;
2135 
2136   ierr = MatEqual(a,c,&flg);CHKERRQ(ierr);
2137   if (flg) {
2138     ierr = MatEqual(b,d,&flg);CHKERRQ(ierr);
2139   }
2140   ierr = MPI_Allreduce(&flg,flag,1,MPI_INT,MPI_LAND,((PetscObject)A)->comm);CHKERRQ(ierr);
2141   PetscFunctionReturn(0);
2142 }
2143 
2144 #undef __FUNCT__
2145 #define __FUNCT__ "MatCopy_MPIAIJ"
2146 PetscErrorCode MatCopy_MPIAIJ(Mat A,Mat B,MatStructure str)
2147 {
2148   PetscErrorCode ierr;
2149   Mat_MPIAIJ     *a = (Mat_MPIAIJ *)A->data;
2150   Mat_MPIAIJ     *b = (Mat_MPIAIJ *)B->data;
2151 
2152   PetscFunctionBegin;
2153   /* If the two matrices don't have the same copy implementation, they aren't compatible for fast copy. */
2154   if ((str != SAME_NONZERO_PATTERN) || (A->ops->copy != B->ops->copy)) {
2155     /* because of the column compression in the off-processor part of the matrix a->B,
2156        the number of columns in a->B and b->B may be different, hence we cannot call
2157        the MatCopy() directly on the two parts. If need be, we can provide a more
2158        efficient copy than the MatCopy_Basic() by first uncompressing the a->B matrices
2159        then copying the submatrices */
2160     ierr = MatCopy_Basic(A,B,str);CHKERRQ(ierr);
2161   } else {
2162     ierr = MatCopy(a->A,b->A,str);CHKERRQ(ierr);
2163     ierr = MatCopy(a->B,b->B,str);CHKERRQ(ierr);
2164   }
2165   PetscFunctionReturn(0);
2166 }
2167 
2168 #undef __FUNCT__
2169 #define __FUNCT__ "MatSetUp_MPIAIJ"
2170 PetscErrorCode MatSetUp_MPIAIJ(Mat A)
2171 {
2172   PetscErrorCode ierr;
2173 
2174   PetscFunctionBegin;
2175   ierr =  MatMPIAIJSetPreallocation(A,PETSC_DEFAULT,0,PETSC_DEFAULT,0);CHKERRQ(ierr);
2176   PetscFunctionReturn(0);
2177 }
2178 
2179 #undef __FUNCT__
2180 #define __FUNCT__ "MatAXPYGetPreallocation_MPIAIJ"
2181 /* This is the same as MatAXPYGetPreallocation_SeqAIJ, except that the local-to-global map is provided */
2182 static PetscErrorCode MatAXPYGetPreallocation_MPIAIJ(Mat Y,const PetscInt *yltog,Mat X,const PetscInt *xltog,PetscInt* nnz)
2183 {
2184   PetscInt          i,m=Y->rmap->N;
2185   Mat_SeqAIJ        *x = (Mat_SeqAIJ*)X->data;
2186   Mat_SeqAIJ        *y = (Mat_SeqAIJ*)Y->data;
2187   const PetscInt    *xi = x->i,*yi = y->i;
2188 
2189   PetscFunctionBegin;
2190   /* Set the number of nonzeros in the new matrix */
2191   for(i=0; i<m; i++) {
2192     PetscInt j,k,nzx = xi[i+1] - xi[i],nzy = yi[i+1] - yi[i];
2193     const PetscInt *xj = x->j+xi[i],*yj = y->j+yi[i];
2194     nnz[i] = 0;
2195     for (j=0,k=0; j<nzx; j++) {                   /* Point in X */
2196       for (; k<nzy && yltog[yj[k]]<xltog[xj[j]]; k++) nnz[i]++; /* Catch up to X */
2197       if (k<nzy && yltog[yj[k]]==xltog[xj[j]]) k++;             /* Skip duplicate */
2198       nnz[i]++;
2199     }
2200     for (; k<nzy; k++) nnz[i]++;
2201   }
2202   PetscFunctionReturn(0);
2203 }
2204 
2205 #undef __FUNCT__
2206 #define __FUNCT__ "MatAXPY_MPIAIJ"
2207 PetscErrorCode MatAXPY_MPIAIJ(Mat Y,PetscScalar a,Mat X,MatStructure str)
2208 {
2209   PetscErrorCode ierr;
2210   PetscInt       i;
2211   Mat_MPIAIJ     *xx = (Mat_MPIAIJ *)X->data,*yy = (Mat_MPIAIJ *)Y->data;
2212   PetscBLASInt   bnz,one=1;
2213   Mat_SeqAIJ     *x,*y;
2214 
2215   PetscFunctionBegin;
2216   if (str == SAME_NONZERO_PATTERN) {
2217     PetscScalar alpha = a;
2218     x = (Mat_SeqAIJ *)xx->A->data;
2219     y = (Mat_SeqAIJ *)yy->A->data;
2220     bnz = PetscBLASIntCast(x->nz);
2221     BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one);
2222     x = (Mat_SeqAIJ *)xx->B->data;
2223     y = (Mat_SeqAIJ *)yy->B->data;
2224     bnz = PetscBLASIntCast(x->nz);
2225     BLASaxpy_(&bnz,&alpha,x->a,&one,y->a,&one);
2226   } else if (str == SUBSET_NONZERO_PATTERN) {
2227     ierr = MatAXPY_SeqAIJ(yy->A,a,xx->A,str);CHKERRQ(ierr);
2228 
2229     x = (Mat_SeqAIJ *)xx->B->data;
2230     y = (Mat_SeqAIJ *)yy->B->data;
2231     if (y->xtoy && y->XtoY != xx->B) {
2232       ierr = PetscFree(y->xtoy);CHKERRQ(ierr);
2233       ierr = MatDestroy(&y->XtoY);CHKERRQ(ierr);
2234     }
2235     if (!y->xtoy) { /* get xtoy */
2236       ierr = MatAXPYGetxtoy_Private(xx->B->rmap->n,x->i,x->j,xx->garray,y->i,y->j,yy->garray,&y->xtoy);CHKERRQ(ierr);
2237       y->XtoY = xx->B;
2238       ierr = PetscObjectReference((PetscObject)xx->B);CHKERRQ(ierr);
2239     }
2240     for (i=0; i<x->nz; i++) y->a[y->xtoy[i]] += a*(x->a[i]);
2241   } else {
2242     Mat B;
2243     PetscInt *nnz_d,*nnz_o;
2244     ierr = PetscMalloc(yy->A->rmap->N*sizeof(PetscInt),&nnz_d);CHKERRQ(ierr);
2245     ierr = PetscMalloc(yy->B->rmap->N*sizeof(PetscInt),&nnz_o);CHKERRQ(ierr);
2246     ierr = MatCreate(((PetscObject)Y)->comm,&B);CHKERRQ(ierr);
2247     ierr = PetscObjectSetName((PetscObject)B,((PetscObject)Y)->name);CHKERRQ(ierr);
2248     ierr = MatSetSizes(B,Y->rmap->n,Y->cmap->n,Y->rmap->N,Y->cmap->N);CHKERRQ(ierr);
2249     ierr = MatSetBlockSizes(B,Y->rmap->bs,Y->cmap->bs);CHKERRQ(ierr);
2250     ierr = MatSetType(B,MATMPIAIJ);CHKERRQ(ierr);
2251     ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr);
2252     ierr = MatAXPYGetPreallocation_MPIAIJ(yy->B,yy->garray,xx->B,xx->garray,nnz_o);CHKERRQ(ierr);
2253     ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr);
2254     ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);
2255     ierr = MatHeaderReplace(Y,B);
2256     ierr = PetscFree(nnz_d);CHKERRQ(ierr);
2257     ierr = PetscFree(nnz_o);CHKERRQ(ierr);
2258   }
2259   PetscFunctionReturn(0);
2260 }
2261 
2262 extern PetscErrorCode  MatConjugate_SeqAIJ(Mat);
2263 
2264 #undef __FUNCT__
2265 #define __FUNCT__ "MatConjugate_MPIAIJ"
2266 PetscErrorCode  MatConjugate_MPIAIJ(Mat mat)
2267 {
2268 #if defined(PETSC_USE_COMPLEX)
2269   PetscErrorCode ierr;
2270   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
2271 
2272   PetscFunctionBegin;
2273   ierr = MatConjugate_SeqAIJ(aij->A);CHKERRQ(ierr);
2274   ierr = MatConjugate_SeqAIJ(aij->B);CHKERRQ(ierr);
2275 #else
2276   PetscFunctionBegin;
2277 #endif
2278   PetscFunctionReturn(0);
2279 }
2280 
2281 #undef __FUNCT__
2282 #define __FUNCT__ "MatRealPart_MPIAIJ"
2283 PetscErrorCode MatRealPart_MPIAIJ(Mat A)
2284 {
2285   Mat_MPIAIJ   *a = (Mat_MPIAIJ*)A->data;
2286   PetscErrorCode ierr;
2287 
2288   PetscFunctionBegin;
2289   ierr = MatRealPart(a->A);CHKERRQ(ierr);
2290   ierr = MatRealPart(a->B);CHKERRQ(ierr);
2291   PetscFunctionReturn(0);
2292 }
2293 
2294 #undef __FUNCT__
2295 #define __FUNCT__ "MatImaginaryPart_MPIAIJ"
2296 PetscErrorCode MatImaginaryPart_MPIAIJ(Mat A)
2297 {
2298   Mat_MPIAIJ   *a = (Mat_MPIAIJ*)A->data;
2299   PetscErrorCode ierr;
2300 
2301   PetscFunctionBegin;
2302   ierr = MatImaginaryPart(a->A);CHKERRQ(ierr);
2303   ierr = MatImaginaryPart(a->B);CHKERRQ(ierr);
2304   PetscFunctionReturn(0);
2305 }
2306 
2307 #ifdef PETSC_HAVE_PBGL
2308 
2309 #include <boost/parallel/mpi/bsp_process_group.hpp>
2310 #include <boost/graph/distributed/ilu_default_graph.hpp>
2311 #include <boost/graph/distributed/ilu_0_block.hpp>
2312 #include <boost/graph/distributed/ilu_preconditioner.hpp>
2313 #include <boost/graph/distributed/petsc/interface.hpp>
2314 #include <boost/multi_array.hpp>
2315 #include <boost/parallel/distributed_property_map->hpp>
2316 
2317 #undef __FUNCT__
2318 #define __FUNCT__ "MatILUFactorSymbolic_MPIAIJ"
2319 /*
2320   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2321 */
2322 PetscErrorCode MatILUFactorSymbolic_MPIAIJ(Mat fact,Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
2323 {
2324   namespace petsc = boost::distributed::petsc;
2325 
2326   namespace graph_dist = boost::graph::distributed;
2327   using boost::graph::distributed::ilu_default::process_group_type;
2328   using boost::graph::ilu_permuted;
2329 
2330   PetscBool       row_identity, col_identity;
2331   PetscContainer  c;
2332   PetscInt        m, n, M, N;
2333   PetscErrorCode  ierr;
2334 
2335   PetscFunctionBegin;
2336   if (info->levels != 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only levels = 0 supported for parallel ilu");
2337   ierr = ISIdentity(isrow, &row_identity);CHKERRQ(ierr);
2338   ierr = ISIdentity(iscol, &col_identity);CHKERRQ(ierr);
2339   if (!row_identity || !col_identity) {
2340     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Row and column permutations must be identity for parallel ILU");
2341   }
2342 
2343   process_group_type pg;
2344   typedef graph_dist::ilu_default::ilu_level_graph_type  lgraph_type;
2345   lgraph_type*   lgraph_p = new lgraph_type(petsc::num_global_vertices(A), pg, petsc::matrix_distribution(A, pg));
2346   lgraph_type&   level_graph = *lgraph_p;
2347   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2348 
2349   petsc::read_matrix(A, graph, get(boost::edge_weight, graph));
2350   ilu_permuted(level_graph);
2351 
2352   /* put together the new matrix */
2353   ierr = MatCreate(((PetscObject)A)->comm, fact);CHKERRQ(ierr);
2354   ierr = MatGetLocalSize(A, &m, &n);CHKERRQ(ierr);
2355   ierr = MatGetSize(A, &M, &N);CHKERRQ(ierr);
2356   ierr = MatSetSizes(fact, m, n, M, N);CHKERRQ(ierr);
2357   ierr = MatSetBlockSizes(fact,A->rmap->bs,A->cmap->bs); CHKERRQ(ierr);
2358   ierr = MatSetType(fact, ((PetscObject)A)->type_name);CHKERRQ(ierr);
2359   ierr = MatAssemblyBegin(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2360   ierr = MatAssemblyEnd(fact, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2361 
2362   ierr = PetscContainerCreate(((PetscObject)A)->comm, &c);
2363   ierr = PetscContainerSetPointer(c, lgraph_p);
2364   ierr = PetscObjectCompose((PetscObject) (fact), "graph", (PetscObject) c);
2365   ierr = PetscContainerDestroy(&c);
2366   PetscFunctionReturn(0);
2367 }
2368 
2369 #undef __FUNCT__
2370 #define __FUNCT__ "MatLUFactorNumeric_MPIAIJ"
2371 PetscErrorCode MatLUFactorNumeric_MPIAIJ(Mat B,Mat A, const MatFactorInfo *info)
2372 {
2373   PetscFunctionBegin;
2374   PetscFunctionReturn(0);
2375 }
2376 
2377 #undef __FUNCT__
2378 #define __FUNCT__ "MatSolve_MPIAIJ"
2379 /*
2380   This uses the parallel ILU factorization of Peter Gottschling <pgottsch@osl.iu.edu>
2381 */
2382 PetscErrorCode MatSolve_MPIAIJ(Mat A, Vec b, Vec x)
2383 {
2384   namespace graph_dist = boost::graph::distributed;
2385 
2386   typedef graph_dist::ilu_default::ilu_level_graph_type  lgraph_type;
2387   lgraph_type*   lgraph_p;
2388   PetscContainer c;
2389   PetscErrorCode ierr;
2390 
2391   PetscFunctionBegin;
2392   ierr = PetscObjectQuery((PetscObject) A, "graph", (PetscObject *) &c);CHKERRQ(ierr);
2393   ierr = PetscContainerGetPointer(c, (void **) &lgraph_p);CHKERRQ(ierr);
2394   ierr = VecCopy(b, x);CHKERRQ(ierr);
2395 
2396   PetscScalar* array_x;
2397   ierr = VecGetArray(x, &array_x);CHKERRQ(ierr);
2398   PetscInt sx;
2399   ierr = VecGetSize(x, &sx);CHKERRQ(ierr);
2400 
2401   PetscScalar* array_b;
2402   ierr = VecGetArray(b, &array_b);CHKERRQ(ierr);
2403   PetscInt sb;
2404   ierr = VecGetSize(b, &sb);CHKERRQ(ierr);
2405 
2406   lgraph_type&   level_graph = *lgraph_p;
2407   graph_dist::ilu_default::graph_type&            graph(level_graph.graph);
2408 
2409   typedef boost::multi_array_ref<PetscScalar, 1> array_ref_type;
2410   array_ref_type                                 ref_b(array_b, boost::extents[num_vertices(graph)]),
2411                                                  ref_x(array_x, boost::extents[num_vertices(graph)]);
2412 
2413   typedef boost::iterator_property_map<array_ref_type::iterator,
2414                                 boost::property_map<graph_dist::ilu_default::graph_type, boost::vertex_index_t>::type>  gvector_type;
2415   gvector_type                                   vector_b(ref_b.begin(), get(boost::vertex_index, graph)),
2416                                                  vector_x(ref_x.begin(), get(boost::vertex_index, graph));
2417 
2418   ilu_set_solve(*lgraph_p, vector_b, vector_x);
2419 
2420   PetscFunctionReturn(0);
2421 }
2422 #endif
2423 
2424 typedef struct { /* used by MatGetRedundantMatrix() for reusing matredundant */
2425   PetscInt       nzlocal,nsends,nrecvs;
2426   PetscMPIInt    *send_rank,*recv_rank;
2427   PetscInt       *sbuf_nz,*rbuf_nz,*sbuf_j,**rbuf_j;
2428   PetscScalar    *sbuf_a,**rbuf_a;
2429   PetscErrorCode (*Destroy)(Mat);
2430 } Mat_Redundant;
2431 
2432 #undef __FUNCT__
2433 #define __FUNCT__ "PetscContainerDestroy_MatRedundant"
2434 PetscErrorCode PetscContainerDestroy_MatRedundant(void *ptr)
2435 {
2436   PetscErrorCode       ierr;
2437   Mat_Redundant        *redund=(Mat_Redundant*)ptr;
2438   PetscInt             i;
2439 
2440   PetscFunctionBegin;
2441   ierr = PetscFree2(redund->send_rank,redund->recv_rank);CHKERRQ(ierr);
2442   ierr = PetscFree(redund->sbuf_j);CHKERRQ(ierr);
2443   ierr = PetscFree(redund->sbuf_a);CHKERRQ(ierr);
2444   for (i=0; i<redund->nrecvs; i++){
2445     ierr = PetscFree(redund->rbuf_j[i]);CHKERRQ(ierr);
2446     ierr = PetscFree(redund->rbuf_a[i]);CHKERRQ(ierr);
2447   }
2448   ierr = PetscFree4(redund->sbuf_nz,redund->rbuf_nz,redund->rbuf_j,redund->rbuf_a);CHKERRQ(ierr);
2449   ierr = PetscFree(redund);CHKERRQ(ierr);
2450   PetscFunctionReturn(0);
2451 }
2452 
2453 #undef __FUNCT__
2454 #define __FUNCT__ "MatDestroy_MatRedundant"
2455 PetscErrorCode MatDestroy_MatRedundant(Mat A)
2456 {
2457   PetscErrorCode  ierr;
2458   PetscContainer  container;
2459   Mat_Redundant   *redund=PETSC_NULL;
2460 
2461   PetscFunctionBegin;
2462   ierr = PetscObjectQuery((PetscObject)A,"Mat_Redundant",(PetscObject *)&container);CHKERRQ(ierr);
2463   if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
2464   ierr = PetscContainerGetPointer(container,(void **)&redund);CHKERRQ(ierr);
2465   A->ops->destroy = redund->Destroy;
2466   ierr = PetscObjectCompose((PetscObject)A,"Mat_Redundant",0);CHKERRQ(ierr);
2467   if (A->ops->destroy) {
2468     ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
2469   }
2470   PetscFunctionReturn(0);
2471 }
2472 
2473 #undef __FUNCT__
2474 #define __FUNCT__ "MatGetRedundantMatrix_MPIAIJ"
2475 PetscErrorCode MatGetRedundantMatrix_MPIAIJ(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,PetscInt mlocal_sub,MatReuse reuse,Mat *matredundant)
2476 {
2477   PetscMPIInt    rank,size;
2478   MPI_Comm       comm=((PetscObject)mat)->comm;
2479   PetscErrorCode ierr;
2480   PetscInt       nsends=0,nrecvs=0,i,rownz_max=0;
2481   PetscMPIInt    *send_rank=PETSC_NULL,*recv_rank=PETSC_NULL;
2482   PetscInt       *rowrange=mat->rmap->range;
2483   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
2484   Mat            A=aij->A,B=aij->B,C=*matredundant;
2485   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)B->data;
2486   PetscScalar    *sbuf_a;
2487   PetscInt       nzlocal=a->nz+b->nz;
2488   PetscInt       j,cstart=mat->cmap->rstart,cend=mat->cmap->rend,row,nzA,nzB,ncols,*cworkA,*cworkB;
2489   PetscInt       rstart=mat->rmap->rstart,rend=mat->rmap->rend,*bmap=aij->garray,M,N;
2490   PetscInt       *cols,ctmp,lwrite,*rptr,l,*sbuf_j;
2491   MatScalar      *aworkA,*aworkB;
2492   PetscScalar    *vals;
2493   PetscMPIInt    tag1,tag2,tag3,imdex;
2494   MPI_Request    *s_waits1=PETSC_NULL,*s_waits2=PETSC_NULL,*s_waits3=PETSC_NULL,
2495                  *r_waits1=PETSC_NULL,*r_waits2=PETSC_NULL,*r_waits3=PETSC_NULL;
2496   MPI_Status     recv_status,*send_status;
2497   PetscInt       *sbuf_nz=PETSC_NULL,*rbuf_nz=PETSC_NULL,count;
2498   PetscInt       **rbuf_j=PETSC_NULL;
2499   PetscScalar    **rbuf_a=PETSC_NULL;
2500   Mat_Redundant  *redund=PETSC_NULL;
2501   PetscContainer container;
2502 
2503   PetscFunctionBegin;
2504   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
2505   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
2506 
2507   if (reuse == MAT_REUSE_MATRIX) {
2508     ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
2509     if (M != N || M != mat->rmap->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong global size");
2510     ierr = MatGetLocalSize(C,&M,&N);CHKERRQ(ierr);
2511     if (M != N || M != mlocal_sub) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong local size");
2512     ierr = PetscObjectQuery((PetscObject)C,"Mat_Redundant",(PetscObject *)&container);CHKERRQ(ierr);
2513     if (!container) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Container does not exit");
2514     ierr = PetscContainerGetPointer(container,(void **)&redund);CHKERRQ(ierr);
2515     if (nzlocal != redund->nzlocal) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. Wrong nzlocal");
2516 
2517     nsends    = redund->nsends;
2518     nrecvs    = redund->nrecvs;
2519     send_rank = redund->send_rank;
2520     recv_rank = redund->recv_rank;
2521     sbuf_nz   = redund->sbuf_nz;
2522     rbuf_nz   = redund->rbuf_nz;
2523     sbuf_j    = redund->sbuf_j;
2524     sbuf_a    = redund->sbuf_a;
2525     rbuf_j    = redund->rbuf_j;
2526     rbuf_a    = redund->rbuf_a;
2527   }
2528 
2529   if (reuse == MAT_INITIAL_MATRIX){
2530     PetscMPIInt  subrank,subsize;
2531     PetscInt     nleftover,np_subcomm;
2532     /* get the destination processors' id send_rank, nsends and nrecvs */
2533     ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
2534     ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
2535     ierr = PetscMalloc2(size,PetscMPIInt,&send_rank,size,PetscMPIInt,&recv_rank);
2536     np_subcomm = size/nsubcomm;
2537     nleftover  = size - nsubcomm*np_subcomm;
2538     nsends = 0; nrecvs = 0;
2539     for (i=0; i<size; i++){ /* i=rank*/
2540       if (subrank == i/nsubcomm && rank != i){ /* my_subrank == other's subrank */
2541         send_rank[nsends] = i; nsends++;
2542         recv_rank[nrecvs++] = i;
2543       }
2544     }
2545     if (rank >= size - nleftover){/* this proc is a leftover processor */
2546       i = size-nleftover-1;
2547       j = 0;
2548       while (j < nsubcomm - nleftover){
2549         send_rank[nsends++] = i;
2550         i--; j++;
2551       }
2552     }
2553 
2554     if (nleftover && subsize == size/nsubcomm && subrank==subsize-1){ /* this proc recvs from leftover processors */
2555       for (i=0; i<nleftover; i++){
2556         recv_rank[nrecvs++] = size-nleftover+i;
2557       }
2558     }
2559 
2560     /* allocate sbuf_j, sbuf_a */
2561     i = nzlocal + rowrange[rank+1] - rowrange[rank] + 2;
2562     ierr = PetscMalloc(i*sizeof(PetscInt),&sbuf_j);CHKERRQ(ierr);
2563     ierr = PetscMalloc((nzlocal+1)*sizeof(PetscScalar),&sbuf_a);CHKERRQ(ierr);
2564   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2565 
2566   /* copy mat's local entries into the buffers */
2567   if (reuse == MAT_INITIAL_MATRIX){
2568     rownz_max = 0;
2569     rptr = sbuf_j;
2570     cols = sbuf_j + rend-rstart + 1;
2571     vals = sbuf_a;
2572     rptr[0] = 0;
2573     for (i=0; i<rend-rstart; i++){
2574       row = i + rstart;
2575       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2576       ncols  = nzA + nzB;
2577       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2578       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2579       /* load the column indices for this row into cols */
2580       lwrite = 0;
2581       for (l=0; l<nzB; l++) {
2582         if ((ctmp = bmap[cworkB[l]]) < cstart){
2583           vals[lwrite]   = aworkB[l];
2584           cols[lwrite++] = ctmp;
2585         }
2586       }
2587       for (l=0; l<nzA; l++){
2588         vals[lwrite]   = aworkA[l];
2589         cols[lwrite++] = cstart + cworkA[l];
2590       }
2591       for (l=0; l<nzB; l++) {
2592         if ((ctmp = bmap[cworkB[l]]) >= cend){
2593           vals[lwrite]   = aworkB[l];
2594           cols[lwrite++] = ctmp;
2595         }
2596       }
2597       vals += ncols;
2598       cols += ncols;
2599       rptr[i+1] = rptr[i] + ncols;
2600       if (rownz_max < ncols) rownz_max = ncols;
2601     }
2602     if (rptr[rend-rstart] != a->nz + b->nz) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB, "rptr[%d] %d != %d + %d",rend-rstart,rptr[rend-rstart+1],a->nz,b->nz);
2603   } else { /* only copy matrix values into sbuf_a */
2604     rptr = sbuf_j;
2605     vals = sbuf_a;
2606     rptr[0] = 0;
2607     for (i=0; i<rend-rstart; i++){
2608       row = i + rstart;
2609       nzA    = a->i[i+1] - a->i[i]; nzB = b->i[i+1] - b->i[i];
2610       ncols  = nzA + nzB;
2611       cworkA = a->j + a->i[i]; cworkB = b->j + b->i[i];
2612       aworkA = a->a + a->i[i]; aworkB = b->a + b->i[i];
2613       lwrite = 0;
2614       for (l=0; l<nzB; l++) {
2615         if ((ctmp = bmap[cworkB[l]]) < cstart) vals[lwrite++] = aworkB[l];
2616       }
2617       for (l=0; l<nzA; l++) vals[lwrite++] = aworkA[l];
2618       for (l=0; l<nzB; l++) {
2619         if ((ctmp = bmap[cworkB[l]]) >= cend) vals[lwrite++] = aworkB[l];
2620       }
2621       vals += ncols;
2622       rptr[i+1] = rptr[i] + ncols;
2623     }
2624   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2625 
2626   /* send nzlocal to others, and recv other's nzlocal */
2627   /*--------------------------------------------------*/
2628   if (reuse == MAT_INITIAL_MATRIX){
2629     ierr = PetscMalloc2(3*(nsends + nrecvs)+1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2630     s_waits2 = s_waits3 + nsends;
2631     s_waits1 = s_waits2 + nsends;
2632     r_waits1 = s_waits1 + nsends;
2633     r_waits2 = r_waits1 + nrecvs;
2634     r_waits3 = r_waits2 + nrecvs;
2635   } else {
2636     ierr = PetscMalloc2(nsends + nrecvs +1,MPI_Request,&s_waits3,nsends+1,MPI_Status,&send_status);CHKERRQ(ierr);
2637     r_waits3 = s_waits3 + nsends;
2638   }
2639 
2640   ierr = PetscObjectGetNewTag((PetscObject)mat,&tag3);CHKERRQ(ierr);
2641   if (reuse == MAT_INITIAL_MATRIX){
2642     /* get new tags to keep the communication clean */
2643     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag1);CHKERRQ(ierr);
2644     ierr = PetscObjectGetNewTag((PetscObject)mat,&tag2);CHKERRQ(ierr);
2645     ierr = PetscMalloc4(nsends,PetscInt,&sbuf_nz,nrecvs,PetscInt,&rbuf_nz,nrecvs,PetscInt*,&rbuf_j,nrecvs,PetscScalar*,&rbuf_a);CHKERRQ(ierr);
2646 
2647     /* post receives of other's nzlocal */
2648     for (i=0; i<nrecvs; i++){
2649       ierr = MPI_Irecv(rbuf_nz+i,1,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,r_waits1+i);CHKERRQ(ierr);
2650     }
2651     /* send nzlocal to others */
2652     for (i=0; i<nsends; i++){
2653       sbuf_nz[i] = nzlocal;
2654       ierr = MPI_Isend(sbuf_nz+i,1,MPIU_INT,send_rank[i],tag1,comm,s_waits1+i);CHKERRQ(ierr);
2655     }
2656     /* wait on receives of nzlocal; allocate space for rbuf_j, rbuf_a */
2657     count = nrecvs;
2658     while (count) {
2659       ierr = MPI_Waitany(nrecvs,r_waits1,&imdex,&recv_status);CHKERRQ(ierr);
2660       recv_rank[imdex] = recv_status.MPI_SOURCE;
2661       /* allocate rbuf_a and rbuf_j; then post receives of rbuf_j */
2662       ierr = PetscMalloc((rbuf_nz[imdex]+1)*sizeof(PetscScalar),&rbuf_a[imdex]);CHKERRQ(ierr);
2663 
2664       i = rowrange[recv_status.MPI_SOURCE+1] - rowrange[recv_status.MPI_SOURCE]; /* number of expected mat->i */
2665       rbuf_nz[imdex] += i + 2;
2666       ierr = PetscMalloc(rbuf_nz[imdex]*sizeof(PetscInt),&rbuf_j[imdex]);CHKERRQ(ierr);
2667       ierr = MPI_Irecv(rbuf_j[imdex],rbuf_nz[imdex],MPIU_INT,recv_status.MPI_SOURCE,tag2,comm,r_waits2+imdex);CHKERRQ(ierr);
2668       count--;
2669     }
2670     /* wait on sends of nzlocal */
2671     if (nsends) {ierr = MPI_Waitall(nsends,s_waits1,send_status);CHKERRQ(ierr);}
2672     /* send mat->i,j to others, and recv from other's */
2673     /*------------------------------------------------*/
2674     for (i=0; i<nsends; i++){
2675       j = nzlocal + rowrange[rank+1] - rowrange[rank] + 1;
2676       ierr = MPI_Isend(sbuf_j,j,MPIU_INT,send_rank[i],tag2,comm,s_waits2+i);CHKERRQ(ierr);
2677     }
2678     /* wait on receives of mat->i,j */
2679     /*------------------------------*/
2680     count = nrecvs;
2681     while (count) {
2682       ierr = MPI_Waitany(nrecvs,r_waits2,&imdex,&recv_status);CHKERRQ(ierr);
2683       if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2684       count--;
2685     }
2686     /* wait on sends of mat->i,j */
2687     /*---------------------------*/
2688     if (nsends) {
2689       ierr = MPI_Waitall(nsends,s_waits2,send_status);CHKERRQ(ierr);
2690     }
2691   } /* endof if (reuse == MAT_INITIAL_MATRIX) */
2692 
2693   /* post receives, send and receive mat->a */
2694   /*----------------------------------------*/
2695   for (imdex=0; imdex<nrecvs; imdex++) {
2696     ierr = MPI_Irecv(rbuf_a[imdex],rbuf_nz[imdex],MPIU_SCALAR,recv_rank[imdex],tag3,comm,r_waits3+imdex);CHKERRQ(ierr);
2697   }
2698   for (i=0; i<nsends; i++){
2699     ierr = MPI_Isend(sbuf_a,nzlocal,MPIU_SCALAR,send_rank[i],tag3,comm,s_waits3+i);CHKERRQ(ierr);
2700   }
2701   count = nrecvs;
2702   while (count) {
2703     ierr = MPI_Waitany(nrecvs,r_waits3,&imdex,&recv_status);CHKERRQ(ierr);
2704     if (recv_rank[imdex] != recv_status.MPI_SOURCE) SETERRQ2(PETSC_COMM_SELF,1, "recv_rank %d != MPI_SOURCE %d",recv_rank[imdex],recv_status.MPI_SOURCE);
2705     count--;
2706   }
2707   if (nsends) {
2708     ierr = MPI_Waitall(nsends,s_waits3,send_status);CHKERRQ(ierr);
2709   }
2710 
2711   ierr = PetscFree2(s_waits3,send_status);CHKERRQ(ierr);
2712 
2713   /* create redundant matrix */
2714   /*-------------------------*/
2715   if (reuse == MAT_INITIAL_MATRIX){
2716     /* compute rownz_max for preallocation */
2717     for (imdex=0; imdex<nrecvs; imdex++){
2718       j = rowrange[recv_rank[imdex]+1] - rowrange[recv_rank[imdex]];
2719       rptr = rbuf_j[imdex];
2720       for (i=0; i<j; i++){
2721         ncols = rptr[i+1] - rptr[i];
2722         if (rownz_max < ncols) rownz_max = ncols;
2723       }
2724     }
2725 
2726     ierr = MatCreate(subcomm,&C);CHKERRQ(ierr);
2727     ierr = MatSetSizes(C,mlocal_sub,mlocal_sub,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
2728     ierr = MatSetBlockSizes(C,mat->rmap->bs,mat->cmap->bs); CHKERRQ(ierr);
2729     ierr = MatSetFromOptions(C);CHKERRQ(ierr);
2730     ierr = MatSeqAIJSetPreallocation(C,rownz_max,PETSC_NULL);CHKERRQ(ierr);
2731     ierr = MatMPIAIJSetPreallocation(C,rownz_max,PETSC_NULL,rownz_max,PETSC_NULL);CHKERRQ(ierr);
2732   } else {
2733     C = *matredundant;
2734   }
2735 
2736   /* insert local matrix entries */
2737   rptr = sbuf_j;
2738   cols = sbuf_j + rend-rstart + 1;
2739   vals = sbuf_a;
2740   for (i=0; i<rend-rstart; i++){
2741     row   = i + rstart;
2742     ncols = rptr[i+1] - rptr[i];
2743     ierr = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2744     vals += ncols;
2745     cols += ncols;
2746   }
2747   /* insert received matrix entries */
2748   for (imdex=0; imdex<nrecvs; imdex++){
2749     rstart = rowrange[recv_rank[imdex]];
2750     rend   = rowrange[recv_rank[imdex]+1];
2751     rptr = rbuf_j[imdex];
2752     cols = rbuf_j[imdex] + rend-rstart + 1;
2753     vals = rbuf_a[imdex];
2754     for (i=0; i<rend-rstart; i++){
2755       row   = i + rstart;
2756       ncols = rptr[i+1] - rptr[i];
2757       ierr = MatSetValues(C,1,&row,ncols,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
2758       vals += ncols;
2759       cols += ncols;
2760     }
2761   }
2762   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2763   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
2764   ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
2765   if (M != mat->rmap->N || N != mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"redundant mat size %d != input mat size %d",M,mat->rmap->N);
2766   if (reuse == MAT_INITIAL_MATRIX) {
2767     PetscContainer container;
2768     *matredundant = C;
2769     /* create a supporting struct and attach it to C for reuse */
2770     ierr = PetscNewLog(C,Mat_Redundant,&redund);CHKERRQ(ierr);
2771     ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
2772     ierr = PetscContainerSetPointer(container,redund);CHKERRQ(ierr);
2773     ierr = PetscContainerSetUserDestroy(container,PetscContainerDestroy_MatRedundant);CHKERRQ(ierr);
2774     ierr = PetscObjectCompose((PetscObject)C,"Mat_Redundant",(PetscObject)container);CHKERRQ(ierr);
2775     ierr = PetscContainerDestroy(&container);CHKERRQ(ierr);
2776 
2777     redund->nzlocal = nzlocal;
2778     redund->nsends  = nsends;
2779     redund->nrecvs  = nrecvs;
2780     redund->send_rank = send_rank;
2781     redund->recv_rank = recv_rank;
2782     redund->sbuf_nz = sbuf_nz;
2783     redund->rbuf_nz = rbuf_nz;
2784     redund->sbuf_j  = sbuf_j;
2785     redund->sbuf_a  = sbuf_a;
2786     redund->rbuf_j  = rbuf_j;
2787     redund->rbuf_a  = rbuf_a;
2788 
2789     redund->Destroy = C->ops->destroy;
2790     C->ops->destroy = MatDestroy_MatRedundant;
2791   }
2792   PetscFunctionReturn(0);
2793 }
2794 
2795 #undef __FUNCT__
2796 #define __FUNCT__ "MatGetRowMaxAbs_MPIAIJ"
2797 PetscErrorCode MatGetRowMaxAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2798 {
2799   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2800   PetscErrorCode ierr;
2801   PetscInt       i,*idxb = 0;
2802   PetscScalar    *va,*vb;
2803   Vec            vtmp;
2804 
2805   PetscFunctionBegin;
2806   ierr = MatGetRowMaxAbs(a->A,v,idx);CHKERRQ(ierr);
2807   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2808   if (idx) {
2809     for (i=0; i<A->rmap->n; i++) {
2810       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2811     }
2812   }
2813 
2814   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2815   if (idx) {
2816     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
2817   }
2818   ierr = MatGetRowMaxAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2819   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2820 
2821   for (i=0; i<A->rmap->n; i++){
2822     if (PetscAbsScalar(va[i]) < PetscAbsScalar(vb[i])) {
2823       va[i] = vb[i];
2824       if (idx) idx[i] = a->garray[idxb[i]];
2825     }
2826   }
2827 
2828   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2829   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2830   ierr = PetscFree(idxb);CHKERRQ(ierr);
2831   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2832   PetscFunctionReturn(0);
2833 }
2834 
2835 #undef __FUNCT__
2836 #define __FUNCT__ "MatGetRowMinAbs_MPIAIJ"
2837 PetscErrorCode MatGetRowMinAbs_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2838 {
2839   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
2840   PetscErrorCode ierr;
2841   PetscInt       i,*idxb = 0;
2842   PetscScalar    *va,*vb;
2843   Vec            vtmp;
2844 
2845   PetscFunctionBegin;
2846   ierr = MatGetRowMinAbs(a->A,v,idx);CHKERRQ(ierr);
2847   ierr = VecGetArray(v,&va);CHKERRQ(ierr);
2848   if (idx) {
2849     for (i=0; i<A->cmap->n; i++) {
2850       if (PetscAbsScalar(va[i])) idx[i] += A->cmap->rstart;
2851     }
2852   }
2853 
2854   ierr = VecCreateSeq(PETSC_COMM_SELF,A->rmap->n,&vtmp);CHKERRQ(ierr);
2855   if (idx) {
2856     ierr = PetscMalloc(A->rmap->n*sizeof(PetscInt),&idxb);CHKERRQ(ierr);
2857   }
2858   ierr = MatGetRowMinAbs(a->B,vtmp,idxb);CHKERRQ(ierr);
2859   ierr = VecGetArray(vtmp,&vb);CHKERRQ(ierr);
2860 
2861   for (i=0; i<A->rmap->n; i++){
2862     if (PetscAbsScalar(va[i]) > PetscAbsScalar(vb[i])) {
2863       va[i] = vb[i];
2864       if (idx) idx[i] = a->garray[idxb[i]];
2865     }
2866   }
2867 
2868   ierr = VecRestoreArray(v,&va);CHKERRQ(ierr);
2869   ierr = VecRestoreArray(vtmp,&vb);CHKERRQ(ierr);
2870   ierr = PetscFree(idxb);CHKERRQ(ierr);
2871   ierr = VecDestroy(&vtmp);CHKERRQ(ierr);
2872   PetscFunctionReturn(0);
2873 }
2874 
2875 #undef __FUNCT__
2876 #define __FUNCT__ "MatGetRowMin_MPIAIJ"
2877 PetscErrorCode MatGetRowMin_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2878 {
2879   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
2880   PetscInt       n      = A->rmap->n;
2881   PetscInt       cstart = A->cmap->rstart;
2882   PetscInt      *cmap   = mat->garray;
2883   PetscInt      *diagIdx, *offdiagIdx;
2884   Vec            diagV, offdiagV;
2885   PetscScalar   *a, *diagA, *offdiagA;
2886   PetscInt       r;
2887   PetscErrorCode ierr;
2888 
2889   PetscFunctionBegin;
2890   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
2891   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &diagV);CHKERRQ(ierr);
2892   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &offdiagV);CHKERRQ(ierr);
2893   ierr = MatGetRowMin(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2894   ierr = MatGetRowMin(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2895   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2896   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2897   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2898   for(r = 0; r < n; ++r) {
2899     if (PetscAbsScalar(diagA[r]) <= PetscAbsScalar(offdiagA[r])) {
2900       a[r]   = diagA[r];
2901       idx[r] = cstart + diagIdx[r];
2902     } else {
2903       a[r]   = offdiagA[r];
2904       idx[r] = cmap[offdiagIdx[r]];
2905     }
2906   }
2907   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2908   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2909   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2910   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2911   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2912   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2913   PetscFunctionReturn(0);
2914 }
2915 
2916 #undef __FUNCT__
2917 #define __FUNCT__ "MatGetRowMax_MPIAIJ"
2918 PetscErrorCode MatGetRowMax_MPIAIJ(Mat A, Vec v, PetscInt idx[])
2919 {
2920   Mat_MPIAIJ    *mat    = (Mat_MPIAIJ *) A->data;
2921   PetscInt       n      = A->rmap->n;
2922   PetscInt       cstart = A->cmap->rstart;
2923   PetscInt      *cmap   = mat->garray;
2924   PetscInt      *diagIdx, *offdiagIdx;
2925   Vec            diagV, offdiagV;
2926   PetscScalar   *a, *diagA, *offdiagA;
2927   PetscInt       r;
2928   PetscErrorCode ierr;
2929 
2930   PetscFunctionBegin;
2931   ierr = PetscMalloc2(n,PetscInt,&diagIdx,n,PetscInt,&offdiagIdx);CHKERRQ(ierr);
2932   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &diagV);CHKERRQ(ierr);
2933   ierr = VecCreateSeq(((PetscObject)A)->comm, n, &offdiagV);CHKERRQ(ierr);
2934   ierr = MatGetRowMax(mat->A, diagV,    diagIdx);CHKERRQ(ierr);
2935   ierr = MatGetRowMax(mat->B, offdiagV, offdiagIdx);CHKERRQ(ierr);
2936   ierr = VecGetArray(v,        &a);CHKERRQ(ierr);
2937   ierr = VecGetArray(diagV,    &diagA);CHKERRQ(ierr);
2938   ierr = VecGetArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2939   for(r = 0; r < n; ++r) {
2940     if (PetscAbsScalar(diagA[r]) >= PetscAbsScalar(offdiagA[r])) {
2941       a[r]   = diagA[r];
2942       idx[r] = cstart + diagIdx[r];
2943     } else {
2944       a[r]   = offdiagA[r];
2945       idx[r] = cmap[offdiagIdx[r]];
2946     }
2947   }
2948   ierr = VecRestoreArray(v,        &a);CHKERRQ(ierr);
2949   ierr = VecRestoreArray(diagV,    &diagA);CHKERRQ(ierr);
2950   ierr = VecRestoreArray(offdiagV, &offdiagA);CHKERRQ(ierr);
2951   ierr = VecDestroy(&diagV);CHKERRQ(ierr);
2952   ierr = VecDestroy(&offdiagV);CHKERRQ(ierr);
2953   ierr = PetscFree2(diagIdx, offdiagIdx);CHKERRQ(ierr);
2954   PetscFunctionReturn(0);
2955 }
2956 
2957 #undef __FUNCT__
2958 #define __FUNCT__ "MatGetSeqNonzeroStructure_MPIAIJ"
2959 PetscErrorCode MatGetSeqNonzeroStructure_MPIAIJ(Mat mat,Mat *newmat)
2960 {
2961   PetscErrorCode ierr;
2962   Mat            *dummy;
2963 
2964   PetscFunctionBegin;
2965   ierr = MatGetSubMatrix_MPIAIJ_All(mat,MAT_DO_NOT_GET_VALUES,MAT_INITIAL_MATRIX,&dummy);CHKERRQ(ierr);
2966   *newmat = *dummy;
2967   ierr = PetscFree(dummy);CHKERRQ(ierr);
2968   PetscFunctionReturn(0);
2969 }
2970 
2971 extern PetscErrorCode  MatFDColoringApply_AIJ(Mat,MatFDColoring,Vec,MatStructure*,void*);
2972 
2973 #undef __FUNCT__
2974 #define __FUNCT__ "MatInvertBlockDiagonal_MPIAIJ"
2975 PetscErrorCode  MatInvertBlockDiagonal_MPIAIJ(Mat A,const PetscScalar **values)
2976 {
2977   Mat_MPIAIJ    *a = (Mat_MPIAIJ*) A->data;
2978   PetscErrorCode ierr;
2979 
2980   PetscFunctionBegin;
2981   ierr = MatInvertBlockDiagonal(a->A,values);CHKERRQ(ierr);
2982   PetscFunctionReturn(0);
2983 }
2984 
2985 
2986 /* -------------------------------------------------------------------*/
2987 static struct _MatOps MatOps_Values = {MatSetValues_MPIAIJ,
2988        MatGetRow_MPIAIJ,
2989        MatRestoreRow_MPIAIJ,
2990        MatMult_MPIAIJ,
2991 /* 4*/ MatMultAdd_MPIAIJ,
2992        MatMultTranspose_MPIAIJ,
2993        MatMultTransposeAdd_MPIAIJ,
2994 #ifdef PETSC_HAVE_PBGL
2995        MatSolve_MPIAIJ,
2996 #else
2997        0,
2998 #endif
2999        0,
3000        0,
3001 /*10*/ 0,
3002        0,
3003        0,
3004        MatSOR_MPIAIJ,
3005        MatTranspose_MPIAIJ,
3006 /*15*/ MatGetInfo_MPIAIJ,
3007        MatEqual_MPIAIJ,
3008        MatGetDiagonal_MPIAIJ,
3009        MatDiagonalScale_MPIAIJ,
3010        MatNorm_MPIAIJ,
3011 /*20*/ MatAssemblyBegin_MPIAIJ,
3012        MatAssemblyEnd_MPIAIJ,
3013        MatSetOption_MPIAIJ,
3014        MatZeroEntries_MPIAIJ,
3015 /*24*/ MatZeroRows_MPIAIJ,
3016        0,
3017 #ifdef PETSC_HAVE_PBGL
3018        0,
3019 #else
3020        0,
3021 #endif
3022        0,
3023        0,
3024 /*29*/ MatSetUp_MPIAIJ,
3025 #ifdef PETSC_HAVE_PBGL
3026        0,
3027 #else
3028        0,
3029 #endif
3030        0,
3031        0,
3032        0,
3033 /*34*/ MatDuplicate_MPIAIJ,
3034        0,
3035        0,
3036        0,
3037        0,
3038 /*39*/ MatAXPY_MPIAIJ,
3039        MatGetSubMatrices_MPIAIJ,
3040        MatIncreaseOverlap_MPIAIJ,
3041        MatGetValues_MPIAIJ,
3042        MatCopy_MPIAIJ,
3043 /*44*/ MatGetRowMax_MPIAIJ,
3044        MatScale_MPIAIJ,
3045        0,
3046        0,
3047        MatZeroRowsColumns_MPIAIJ,
3048 /*49*/ 0,
3049        0,
3050        0,
3051        0,
3052        0,
3053 /*54*/ MatFDColoringCreate_MPIAIJ,
3054        0,
3055        MatSetUnfactored_MPIAIJ,
3056        0, /* MatPermute_MPIAIJ, impl currently broken */
3057        0,
3058 /*59*/ MatGetSubMatrix_MPIAIJ,
3059        MatDestroy_MPIAIJ,
3060        MatView_MPIAIJ,
3061        0,
3062        0,
3063 /*64*/ 0,
3064        0,
3065        0,
3066        0,
3067        0,
3068 /*69*/ MatGetRowMaxAbs_MPIAIJ,
3069        MatGetRowMinAbs_MPIAIJ,
3070        0,
3071        MatSetColoring_MPIAIJ,
3072 #if defined(PETSC_HAVE_ADIC)
3073        MatSetValuesAdic_MPIAIJ,
3074 #else
3075        0,
3076 #endif
3077        MatSetValuesAdifor_MPIAIJ,
3078 /*75*/ MatFDColoringApply_AIJ,
3079        0,
3080        0,
3081        0,
3082        0,
3083 /*80*/ 0,
3084        0,
3085        0,
3086 /*83*/ MatLoad_MPIAIJ,
3087        0,
3088        0,
3089        0,
3090        0,
3091        0,
3092 /*89*/ MatMatMult_MPIAIJ_MPIAIJ,
3093        MatMatMultSymbolic_MPIAIJ_MPIAIJ,
3094        MatMatMultNumeric_MPIAIJ_MPIAIJ,
3095        MatPtAP_Basic,
3096        MatPtAPSymbolic_MPIAIJ,
3097 /*94*/ MatPtAPNumeric_MPIAIJ,
3098        0,
3099        0,
3100        0,
3101        0,
3102 /*99*/ 0,
3103        MatPtAPSymbolic_MPIAIJ_MPIAIJ,
3104        MatPtAPNumeric_MPIAIJ_MPIAIJ,
3105        MatConjugate_MPIAIJ,
3106        0,
3107 /*104*/MatSetValuesRow_MPIAIJ,
3108        MatRealPart_MPIAIJ,
3109        MatImaginaryPart_MPIAIJ,
3110        0,
3111        0,
3112 /*109*/0,
3113        MatGetRedundantMatrix_MPIAIJ,
3114        MatGetRowMin_MPIAIJ,
3115        0,
3116        0,
3117 /*114*/MatGetSeqNonzeroStructure_MPIAIJ,
3118        0,
3119        0,
3120        0,
3121        0,
3122 /*119*/0,
3123        0,
3124        0,
3125        0,
3126        MatGetMultiProcBlock_MPIAIJ,
3127 /*124*/MatFindNonZeroRows_MPIAIJ,
3128        MatGetColumnNorms_MPIAIJ,
3129        MatInvertBlockDiagonal_MPIAIJ,
3130        0,
3131        MatGetSubMatricesParallel_MPIAIJ,
3132 /*129*/0,
3133        MatTransposeMatMult_MPIAIJ_MPIAIJ,
3134        MatTransposeMatMultSymbolic_MPIAIJ_MPIAIJ,
3135        MatTransposeMatMultNumeric_MPIAIJ_MPIAIJ,
3136        0,
3137 /*134*/0,
3138        0,
3139        0,
3140        0,
3141        0
3142 };
3143 
3144 /* ----------------------------------------------------------------------------------------*/
3145 
3146 EXTERN_C_BEGIN
3147 #undef __FUNCT__
3148 #define __FUNCT__ "MatStoreValues_MPIAIJ"
3149 PetscErrorCode  MatStoreValues_MPIAIJ(Mat mat)
3150 {
3151   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
3152   PetscErrorCode ierr;
3153 
3154   PetscFunctionBegin;
3155   ierr = MatStoreValues(aij->A);CHKERRQ(ierr);
3156   ierr = MatStoreValues(aij->B);CHKERRQ(ierr);
3157   PetscFunctionReturn(0);
3158 }
3159 EXTERN_C_END
3160 
3161 EXTERN_C_BEGIN
3162 #undef __FUNCT__
3163 #define __FUNCT__ "MatRetrieveValues_MPIAIJ"
3164 PetscErrorCode  MatRetrieveValues_MPIAIJ(Mat mat)
3165 {
3166   Mat_MPIAIJ     *aij = (Mat_MPIAIJ *)mat->data;
3167   PetscErrorCode ierr;
3168 
3169   PetscFunctionBegin;
3170   ierr = MatRetrieveValues(aij->A);CHKERRQ(ierr);
3171   ierr = MatRetrieveValues(aij->B);CHKERRQ(ierr);
3172   PetscFunctionReturn(0);
3173 }
3174 EXTERN_C_END
3175 
3176 EXTERN_C_BEGIN
3177 #undef __FUNCT__
3178 #define __FUNCT__ "MatMPIAIJSetPreallocation_MPIAIJ"
3179 PetscErrorCode  MatMPIAIJSetPreallocation_MPIAIJ(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3180 {
3181   Mat_MPIAIJ     *b;
3182   PetscErrorCode ierr;
3183   PetscInt       i;
3184   PetscBool      d_realalloc = PETSC_FALSE,o_realalloc = PETSC_FALSE;
3185 
3186   PetscFunctionBegin;
3187   if (d_nz >= 0 || d_nnz) d_realalloc = PETSC_TRUE;
3188   if (o_nz >= 0 || o_nnz) o_realalloc = PETSC_TRUE;
3189   if (d_nz == PETSC_DEFAULT || d_nz == PETSC_DECIDE) d_nz = 5;
3190   if (o_nz == PETSC_DEFAULT || o_nz == PETSC_DECIDE) o_nz = 2;
3191   if (d_nz < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"d_nz cannot be less than 0: value %D",d_nz);
3192   if (o_nz < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"o_nz cannot be less than 0: value %D",o_nz);
3193 
3194   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3195   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3196   if (d_nnz) {
3197     for (i=0; i<B->rmap->n; i++) {
3198       if (d_nnz[i] < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"d_nnz cannot be less than 0: local row %D value %D",i,d_nnz[i]);
3199     }
3200   }
3201   if (o_nnz) {
3202     for (i=0; i<B->rmap->n; i++) {
3203       if (o_nnz[i] < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"o_nnz cannot be less than 0: local row %D value %D",i,o_nnz[i]);
3204     }
3205   }
3206   b = (Mat_MPIAIJ*)B->data;
3207 
3208   if (!B->preallocated) {
3209     /* Explicitly create 2 MATSEQAIJ matrices. */
3210     ierr = MatCreate(PETSC_COMM_SELF,&b->A);CHKERRQ(ierr);
3211     ierr = MatSetSizes(b->A,B->rmap->n,B->cmap->n,B->rmap->n,B->cmap->n);CHKERRQ(ierr);
3212     ierr = MatSetBlockSizes(b->A,B->rmap->bs,B->cmap->bs);CHKERRQ(ierr);
3213     ierr = MatSetType(b->A,MATSEQAIJ);CHKERRQ(ierr);
3214     ierr = PetscLogObjectParent(B,b->A);CHKERRQ(ierr);
3215     ierr = MatCreate(PETSC_COMM_SELF,&b->B);CHKERRQ(ierr);
3216     ierr = MatSetSizes(b->B,B->rmap->n,B->cmap->N,B->rmap->n,B->cmap->N);CHKERRQ(ierr);
3217     ierr = MatSetBlockSizes(b->B,B->rmap->bs,B->cmap->bs);CHKERRQ(ierr);
3218     ierr = MatSetType(b->B,MATSEQAIJ);CHKERRQ(ierr);
3219     ierr = PetscLogObjectParent(B,b->B);CHKERRQ(ierr);
3220   }
3221 
3222   ierr = MatSeqAIJSetPreallocation(b->A,d_nz,d_nnz);CHKERRQ(ierr);
3223   ierr = MatSeqAIJSetPreallocation(b->B,o_nz,o_nnz);CHKERRQ(ierr);
3224   /* Do not error if the user did not give real preallocation information. Ugly because this would overwrite a previous user call to MatSetOption(). */
3225   if (!d_realalloc) {ierr = MatSetOption(b->A,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);}
3226   if (!o_realalloc) {ierr = MatSetOption(b->B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);}
3227   B->preallocated = PETSC_TRUE;
3228   PetscFunctionReturn(0);
3229 }
3230 EXTERN_C_END
3231 
3232 #undef __FUNCT__
3233 #define __FUNCT__ "MatDuplicate_MPIAIJ"
3234 PetscErrorCode MatDuplicate_MPIAIJ(Mat matin,MatDuplicateOption cpvalues,Mat *newmat)
3235 {
3236   Mat            mat;
3237   Mat_MPIAIJ     *a,*oldmat = (Mat_MPIAIJ*)matin->data;
3238   PetscErrorCode ierr;
3239 
3240   PetscFunctionBegin;
3241   *newmat       = 0;
3242   ierr = MatCreate(((PetscObject)matin)->comm,&mat);CHKERRQ(ierr);
3243   ierr = MatSetSizes(mat,matin->rmap->n,matin->cmap->n,matin->rmap->N,matin->cmap->N);CHKERRQ(ierr);
3244   ierr = MatSetBlockSizes(mat,matin->rmap->bs,matin->cmap->bs);CHKERRQ(ierr);
3245   ierr = MatSetType(mat,((PetscObject)matin)->type_name);CHKERRQ(ierr);
3246   ierr = PetscMemcpy(mat->ops,matin->ops,sizeof(struct _MatOps));CHKERRQ(ierr);
3247   a    = (Mat_MPIAIJ*)mat->data;
3248 
3249   mat->factortype    = matin->factortype;
3250   mat->rmap->bs      = matin->rmap->bs;
3251   mat->cmap->bs      = matin->cmap->bs;
3252   mat->assembled    = PETSC_TRUE;
3253   mat->insertmode   = NOT_SET_VALUES;
3254   mat->preallocated = PETSC_TRUE;
3255 
3256   a->size           = oldmat->size;
3257   a->rank           = oldmat->rank;
3258   a->donotstash     = oldmat->donotstash;
3259   a->roworiented    = oldmat->roworiented;
3260   a->rowindices     = 0;
3261   a->rowvalues      = 0;
3262   a->getrowactive   = PETSC_FALSE;
3263 
3264   ierr = PetscLayoutReference(matin->rmap,&mat->rmap);CHKERRQ(ierr);
3265   ierr = PetscLayoutReference(matin->cmap,&mat->cmap);CHKERRQ(ierr);
3266 
3267   if (oldmat->colmap) {
3268 #if defined (PETSC_USE_CTABLE)
3269     ierr = PetscTableCreateCopy(oldmat->colmap,&a->colmap);CHKERRQ(ierr);
3270 #else
3271     ierr = PetscMalloc((mat->cmap->N)*sizeof(PetscInt),&a->colmap);CHKERRQ(ierr);
3272     ierr = PetscLogObjectMemory(mat,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3273     ierr = PetscMemcpy(a->colmap,oldmat->colmap,(mat->cmap->N)*sizeof(PetscInt));CHKERRQ(ierr);
3274 #endif
3275   } else a->colmap = 0;
3276   if (oldmat->garray) {
3277     PetscInt len;
3278     len  = oldmat->B->cmap->n;
3279     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&a->garray);CHKERRQ(ierr);
3280     ierr = PetscLogObjectMemory(mat,len*sizeof(PetscInt));CHKERRQ(ierr);
3281     if (len) { ierr = PetscMemcpy(a->garray,oldmat->garray,len*sizeof(PetscInt));CHKERRQ(ierr); }
3282   } else a->garray = 0;
3283 
3284   ierr = VecDuplicate(oldmat->lvec,&a->lvec);CHKERRQ(ierr);
3285   ierr = PetscLogObjectParent(mat,a->lvec);CHKERRQ(ierr);
3286   ierr = VecScatterCopy(oldmat->Mvctx,&a->Mvctx);CHKERRQ(ierr);
3287   ierr = PetscLogObjectParent(mat,a->Mvctx);CHKERRQ(ierr);
3288   ierr = MatDuplicate(oldmat->A,cpvalues,&a->A);CHKERRQ(ierr);
3289   ierr = PetscLogObjectParent(mat,a->A);CHKERRQ(ierr);
3290   ierr = MatDuplicate(oldmat->B,cpvalues,&a->B);CHKERRQ(ierr);
3291   ierr = PetscLogObjectParent(mat,a->B);CHKERRQ(ierr);
3292   ierr = PetscFListDuplicate(((PetscObject)matin)->qlist,&((PetscObject)mat)->qlist);CHKERRQ(ierr);
3293   *newmat = mat;
3294   PetscFunctionReturn(0);
3295 }
3296 
3297 
3298 
3299 #undef __FUNCT__
3300 #define __FUNCT__ "MatLoad_MPIAIJ"
3301 PetscErrorCode MatLoad_MPIAIJ(Mat newMat, PetscViewer viewer)
3302 {
3303   PetscScalar    *vals,*svals;
3304   MPI_Comm       comm = ((PetscObject)viewer)->comm;
3305   PetscErrorCode ierr;
3306   PetscMPIInt    rank,size,tag = ((PetscObject)viewer)->tag;
3307   PetscInt       i,nz,j,rstart,rend,mmax,maxnz = 0,grows,gcols;
3308   PetscInt       header[4],*rowlengths = 0,M,N,m,*cols;
3309   PetscInt       *ourlens = PETSC_NULL,*procsnz = PETSC_NULL,*offlens = PETSC_NULL,jj,*mycols,*smycols;
3310   PetscInt       cend,cstart,n,*rowners,sizesset=1;
3311   int            fd;
3312 
3313   PetscFunctionBegin;
3314   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3315   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3316   if (!rank) {
3317     ierr = PetscViewerBinaryGetDescriptor(viewer,&fd);CHKERRQ(ierr);
3318     ierr = PetscBinaryRead(fd,(char *)header,4,PETSC_INT);CHKERRQ(ierr);
3319     if (header[0] != MAT_FILE_CLASSID) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"not matrix object");
3320   }
3321 
3322   if (newMat->rmap->n < 0 && newMat->rmap->N < 0 && newMat->cmap->n < 0 && newMat->cmap->N < 0) sizesset = 0;
3323 
3324   ierr = MPI_Bcast(header+1,3,MPIU_INT,0,comm);CHKERRQ(ierr);
3325   M = header[1]; N = header[2];
3326   /* If global rows/cols are set to PETSC_DECIDE, set it to the sizes given in the file */
3327   if (sizesset && newMat->rmap->N < 0) newMat->rmap->N = M;
3328   if (sizesset && newMat->cmap->N < 0) newMat->cmap->N = N;
3329 
3330   /* If global sizes are set, check if they are consistent with that given in the file */
3331   if (sizesset) {
3332     ierr = MatGetSize(newMat,&grows,&gcols);CHKERRQ(ierr);
3333   }
3334   if (sizesset && newMat->rmap->N != grows) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of rows:Matrix in file has (%d) and input matrix has (%d)",M,grows);
3335   if (sizesset && newMat->cmap->N != gcols) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED, "Inconsistent # of cols:Matrix in file has (%d) and input matrix has (%d)",N,gcols);
3336 
3337   /* determine ownership of all rows */
3338   if (newMat->rmap->n < 0 ) m    = M/size + ((M % size) > rank); /* PETSC_DECIDE */
3339   else m = newMat->rmap->n; /* Set by user */
3340 
3341   ierr = PetscMalloc((size+1)*sizeof(PetscInt),&rowners);CHKERRQ(ierr);
3342   ierr = MPI_Allgather(&m,1,MPIU_INT,rowners+1,1,MPIU_INT,comm);CHKERRQ(ierr);
3343 
3344   /* First process needs enough room for process with most rows */
3345   if (!rank) {
3346     mmax       = rowners[1];
3347     for (i=2; i<size; i++) {
3348       mmax = PetscMax(mmax,rowners[i]);
3349     }
3350   } else mmax = m;
3351 
3352   rowners[0] = 0;
3353   for (i=2; i<=size; i++) {
3354     rowners[i] += rowners[i-1];
3355   }
3356   rstart = rowners[rank];
3357   rend   = rowners[rank+1];
3358 
3359   /* distribute row lengths to all processors */
3360   ierr    = PetscMalloc2(mmax,PetscInt,&ourlens,mmax,PetscInt,&offlens);CHKERRQ(ierr);
3361   if (!rank) {
3362     ierr = PetscBinaryRead(fd,ourlens,m,PETSC_INT);CHKERRQ(ierr);
3363     ierr = PetscMalloc(m*sizeof(PetscInt),&rowlengths);CHKERRQ(ierr);
3364     ierr = PetscMalloc(size*sizeof(PetscInt),&procsnz);CHKERRQ(ierr);
3365     ierr = PetscMemzero(procsnz,size*sizeof(PetscInt));CHKERRQ(ierr);
3366     for (j=0; j<m; j++) {
3367       procsnz[0] += ourlens[j];
3368     }
3369     for (i=1; i<size; i++) {
3370       ierr = PetscBinaryRead(fd,rowlengths,rowners[i+1]-rowners[i],PETSC_INT);CHKERRQ(ierr);
3371       /* calculate the number of nonzeros on each processor */
3372       for (j=0; j<rowners[i+1]-rowners[i]; j++) {
3373         procsnz[i] += rowlengths[j];
3374       }
3375       ierr = MPIULong_Send(rowlengths,rowners[i+1]-rowners[i],MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3376     }
3377     ierr = PetscFree(rowlengths);CHKERRQ(ierr);
3378   } else {
3379     ierr = MPIULong_Recv(ourlens,m,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3380   }
3381 
3382   if (!rank) {
3383     /* determine max buffer needed and allocate it */
3384     maxnz = 0;
3385     for (i=0; i<size; i++) {
3386       maxnz = PetscMax(maxnz,procsnz[i]);
3387     }
3388     ierr = PetscMalloc(maxnz*sizeof(PetscInt),&cols);CHKERRQ(ierr);
3389 
3390     /* read in my part of the matrix column indices  */
3391     nz   = procsnz[0];
3392     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
3393     ierr = PetscBinaryRead(fd,mycols,nz,PETSC_INT);CHKERRQ(ierr);
3394 
3395     /* read in every one elses and ship off */
3396     for (i=1; i<size; i++) {
3397       nz     = procsnz[i];
3398       ierr   = PetscBinaryRead(fd,cols,nz,PETSC_INT);CHKERRQ(ierr);
3399       ierr   = MPIULong_Send(cols,nz,MPIU_INT,i,tag,comm);CHKERRQ(ierr);
3400     }
3401     ierr = PetscFree(cols);CHKERRQ(ierr);
3402   } else {
3403     /* determine buffer space needed for message */
3404     nz = 0;
3405     for (i=0; i<m; i++) {
3406       nz += ourlens[i];
3407     }
3408     ierr = PetscMalloc(nz*sizeof(PetscInt),&mycols);CHKERRQ(ierr);
3409 
3410     /* receive message of column indices*/
3411     ierr = MPIULong_Recv(mycols,nz,MPIU_INT,0,tag,comm);CHKERRQ(ierr);
3412   }
3413 
3414   /* determine column ownership if matrix is not square */
3415   if (N != M) {
3416     if (newMat->cmap->n < 0) n      = N/size + ((N % size) > rank);
3417     else n = newMat->cmap->n;
3418     ierr   = MPI_Scan(&n,&cend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3419     cstart = cend - n;
3420   } else {
3421     cstart = rstart;
3422     cend   = rend;
3423     n      = cend - cstart;
3424   }
3425 
3426   /* loop over local rows, determining number of off diagonal entries */
3427   ierr = PetscMemzero(offlens,m*sizeof(PetscInt));CHKERRQ(ierr);
3428   jj = 0;
3429   for (i=0; i<m; i++) {
3430     for (j=0; j<ourlens[i]; j++) {
3431       if (mycols[jj] < cstart || mycols[jj] >= cend) offlens[i]++;
3432       jj++;
3433     }
3434   }
3435 
3436   for (i=0; i<m; i++) {
3437     ourlens[i] -= offlens[i];
3438   }
3439   if (!sizesset) {
3440     ierr = MatSetSizes(newMat,m,n,M,N);CHKERRQ(ierr);
3441   }
3442   ierr = MatMPIAIJSetPreallocation(newMat,0,ourlens,0,offlens);CHKERRQ(ierr);
3443 
3444   for (i=0; i<m; i++) {
3445     ourlens[i] += offlens[i];
3446   }
3447 
3448   if (!rank) {
3449     ierr = PetscMalloc((maxnz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
3450 
3451     /* read in my part of the matrix numerical values  */
3452     nz   = procsnz[0];
3453     ierr = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3454 
3455     /* insert into matrix */
3456     jj      = rstart;
3457     smycols = mycols;
3458     svals   = vals;
3459     for (i=0; i<m; i++) {
3460       ierr = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3461       smycols += ourlens[i];
3462       svals   += ourlens[i];
3463       jj++;
3464     }
3465 
3466     /* read in other processors and ship out */
3467     for (i=1; i<size; i++) {
3468       nz     = procsnz[i];
3469       ierr   = PetscBinaryRead(fd,vals,nz,PETSC_SCALAR);CHKERRQ(ierr);
3470       ierr   = MPIULong_Send(vals,nz,MPIU_SCALAR,i,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3471     }
3472     ierr = PetscFree(procsnz);CHKERRQ(ierr);
3473   } else {
3474     /* receive numeric values */
3475     ierr = PetscMalloc((nz+1)*sizeof(PetscScalar),&vals);CHKERRQ(ierr);
3476 
3477     /* receive message of values*/
3478     ierr   = MPIULong_Recv(vals,nz,MPIU_SCALAR,0,((PetscObject)newMat)->tag,comm);CHKERRQ(ierr);
3479 
3480     /* insert into matrix */
3481     jj      = rstart;
3482     smycols = mycols;
3483     svals   = vals;
3484     for (i=0; i<m; i++) {
3485       ierr     = MatSetValues_MPIAIJ(newMat,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
3486       smycols += ourlens[i];
3487       svals   += ourlens[i];
3488       jj++;
3489     }
3490   }
3491   ierr = PetscFree2(ourlens,offlens);CHKERRQ(ierr);
3492   ierr = PetscFree(vals);CHKERRQ(ierr);
3493   ierr = PetscFree(mycols);CHKERRQ(ierr);
3494   ierr = PetscFree(rowners);CHKERRQ(ierr);
3495 
3496   ierr = MatAssemblyBegin(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3497   ierr = MatAssemblyEnd(newMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3498   PetscFunctionReturn(0);
3499 }
3500 
3501 #undef __FUNCT__
3502 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ"
3503 PetscErrorCode MatGetSubMatrix_MPIAIJ(Mat mat,IS isrow,IS iscol,MatReuse call,Mat *newmat)
3504 {
3505   PetscErrorCode ierr;
3506   IS             iscol_local;
3507   PetscInt       csize;
3508 
3509   PetscFunctionBegin;
3510   ierr = ISGetLocalSize(iscol,&csize);CHKERRQ(ierr);
3511   if (call == MAT_REUSE_MATRIX) {
3512     ierr = PetscObjectQuery((PetscObject)*newmat,"ISAllGather",(PetscObject*)&iscol_local);CHKERRQ(ierr);
3513     if (!iscol_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3514   } else {
3515     PetscInt cbs;
3516     ierr = ISGetBlockSize(iscol,&cbs); CHKERRQ(ierr);
3517     ierr = ISAllGather(iscol,&iscol_local);CHKERRQ(ierr);
3518     ierr = ISSetBlockSize(iscol_local,cbs); CHKERRQ(ierr);
3519   }
3520   ierr = MatGetSubMatrix_MPIAIJ_Private(mat,isrow,iscol_local,csize,call,newmat);CHKERRQ(ierr);
3521   if (call == MAT_INITIAL_MATRIX) {
3522     ierr = PetscObjectCompose((PetscObject)*newmat,"ISAllGather",(PetscObject)iscol_local);CHKERRQ(ierr);
3523     ierr = ISDestroy(&iscol_local);CHKERRQ(ierr);
3524   }
3525   PetscFunctionReturn(0);
3526 }
3527 
3528 extern PetscErrorCode MatGetSubMatrices_MPIAIJ_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,PetscBool*,Mat*);
3529 #undef __FUNCT__
3530 #define __FUNCT__ "MatGetSubMatrix_MPIAIJ_Private"
3531 /*
3532     Not great since it makes two copies of the submatrix, first an SeqAIJ
3533   in local and then by concatenating the local matrices the end result.
3534   Writing it directly would be much like MatGetSubMatrices_MPIAIJ()
3535 
3536   Note: This requires a sequential iscol with all indices.
3537 */
3538 PetscErrorCode MatGetSubMatrix_MPIAIJ_Private(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse call,Mat *newmat)
3539 {
3540   PetscErrorCode ierr;
3541   PetscMPIInt    rank,size;
3542   PetscInt       i,m,n,rstart,row,rend,nz,*cwork,j,bs,cbs;
3543   PetscInt       *ii,*jj,nlocal,*dlens,*olens,dlen,olen,jend,mglobal,ncol;
3544   PetscBool      allcolumns, colflag;
3545   Mat            M,Mreuse;
3546   MatScalar      *vwork,*aa;
3547   MPI_Comm       comm = ((PetscObject)mat)->comm;
3548   Mat_SeqAIJ     *aij;
3549 
3550 
3551   PetscFunctionBegin;
3552   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
3553   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3554 
3555   ierr = ISIdentity(iscol,&colflag);CHKERRQ(ierr);
3556   ierr = ISGetLocalSize(iscol,&ncol);CHKERRQ(ierr);
3557   if (colflag && ncol == mat->cmap->N){
3558     allcolumns = PETSC_TRUE;
3559   } else {
3560     allcolumns = PETSC_FALSE;
3561   }
3562   if (call ==  MAT_REUSE_MATRIX) {
3563     ierr = PetscObjectQuery((PetscObject)*newmat,"SubMatrix",(PetscObject *)&Mreuse);CHKERRQ(ierr);
3564     if (!Mreuse) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Submatrix passed in was not used before, cannot reuse");
3565     ierr  = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_REUSE_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3566   } else {
3567     ierr   = MatGetSubMatrices_MPIAIJ_Local(mat,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&allcolumns,&Mreuse);CHKERRQ(ierr);
3568   }
3569 
3570   /*
3571       m - number of local rows
3572       n - number of columns (same on all processors)
3573       rstart - first row in new global matrix generated
3574   */
3575   ierr = MatGetSize(Mreuse,&m,&n);CHKERRQ(ierr);
3576   ierr = MatGetBlockSizes(Mreuse,&bs,&cbs);CHKERRQ(ierr);
3577   if (call == MAT_INITIAL_MATRIX) {
3578     aij = (Mat_SeqAIJ*)(Mreuse)->data;
3579     ii  = aij->i;
3580     jj  = aij->j;
3581 
3582     /*
3583         Determine the number of non-zeros in the diagonal and off-diagonal
3584         portions of the matrix in order to do correct preallocation
3585     */
3586 
3587     /* first get start and end of "diagonal" columns */
3588     if (csize == PETSC_DECIDE) {
3589       ierr = ISGetSize(isrow,&mglobal);CHKERRQ(ierr);
3590       if (mglobal == n) { /* square matrix */
3591 	nlocal = m;
3592       } else {
3593         nlocal = n/size + ((n % size) > rank);
3594       }
3595     } else {
3596       nlocal = csize;
3597     }
3598     ierr   = MPI_Scan(&nlocal,&rend,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
3599     rstart = rend - nlocal;
3600     if (rank == size - 1 && rend != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Local column sizes %D do not add up to total number of columns %D",rend,n);
3601 
3602     /* next, compute all the lengths */
3603     ierr  = PetscMalloc((2*m+1)*sizeof(PetscInt),&dlens);CHKERRQ(ierr);
3604     olens = dlens + m;
3605     for (i=0; i<m; i++) {
3606       jend = ii[i+1] - ii[i];
3607       olen = 0;
3608       dlen = 0;
3609       for (j=0; j<jend; j++) {
3610         if (*jj < rstart || *jj >= rend) olen++;
3611         else dlen++;
3612         jj++;
3613       }
3614       olens[i] = olen;
3615       dlens[i] = dlen;
3616     }
3617     ierr = MatCreate(comm,&M);CHKERRQ(ierr);
3618     ierr = MatSetSizes(M,m,nlocal,PETSC_DECIDE,n);CHKERRQ(ierr);
3619     ierr = MatSetBlockSizes(M,bs,cbs); CHKERRQ(ierr);
3620     ierr = MatSetType(M,((PetscObject)mat)->type_name);CHKERRQ(ierr);
3621     ierr = MatMPIAIJSetPreallocation(M,0,dlens,0,olens);CHKERRQ(ierr);
3622     ierr = PetscFree(dlens);CHKERRQ(ierr);
3623   } else {
3624     PetscInt ml,nl;
3625 
3626     M = *newmat;
3627     ierr = MatGetLocalSize(M,&ml,&nl);CHKERRQ(ierr);
3628     if (ml != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Previous matrix must be same size/layout as request");
3629     ierr = MatZeroEntries(M);CHKERRQ(ierr);
3630     /*
3631          The next two lines are needed so we may call MatSetValues_MPIAIJ() below directly,
3632        rather than the slower MatSetValues().
3633     */
3634     M->was_assembled = PETSC_TRUE;
3635     M->assembled     = PETSC_FALSE;
3636   }
3637   ierr = MatGetOwnershipRange(M,&rstart,&rend);CHKERRQ(ierr);
3638   aij = (Mat_SeqAIJ*)(Mreuse)->data;
3639   ii  = aij->i;
3640   jj  = aij->j;
3641   aa  = aij->a;
3642   for (i=0; i<m; i++) {
3643     row   = rstart + i;
3644     nz    = ii[i+1] - ii[i];
3645     cwork = jj;     jj += nz;
3646     vwork = aa;     aa += nz;
3647     ierr = MatSetValues_MPIAIJ(M,1,&row,nz,cwork,vwork,INSERT_VALUES);CHKERRQ(ierr);
3648   }
3649 
3650   ierr = MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3651   ierr = MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3652   *newmat = M;
3653 
3654   /* save submatrix used in processor for next request */
3655   if (call ==  MAT_INITIAL_MATRIX) {
3656     ierr = PetscObjectCompose((PetscObject)M,"SubMatrix",(PetscObject)Mreuse);CHKERRQ(ierr);
3657     ierr = MatDestroy(&Mreuse);CHKERRQ(ierr);
3658   }
3659 
3660   PetscFunctionReturn(0);
3661 }
3662 
3663 EXTERN_C_BEGIN
3664 #undef __FUNCT__
3665 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR_MPIAIJ"
3666 PetscErrorCode  MatMPIAIJSetPreallocationCSR_MPIAIJ(Mat B,const PetscInt Ii[],const PetscInt J[],const PetscScalar v[])
3667 {
3668   PetscInt       m,cstart, cend,j,nnz,i,d;
3669   PetscInt       *d_nnz,*o_nnz,nnz_max = 0,rstart,ii;
3670   const PetscInt *JJ;
3671   PetscScalar    *values;
3672   PetscErrorCode ierr;
3673 
3674   PetscFunctionBegin;
3675   if (Ii[0]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Ii[0] must be 0 it is %D",Ii[0]);
3676 
3677   ierr = PetscLayoutSetUp(B->rmap);CHKERRQ(ierr);
3678   ierr = PetscLayoutSetUp(B->cmap);CHKERRQ(ierr);
3679   m      = B->rmap->n;
3680   cstart = B->cmap->rstart;
3681   cend   = B->cmap->rend;
3682   rstart = B->rmap->rstart;
3683 
3684   ierr  = PetscMalloc2(m,PetscInt,&d_nnz,m,PetscInt,&o_nnz);CHKERRQ(ierr);
3685 
3686 #if defined(PETSC_USE_DEBUGGING)
3687   for (i=0; i<m; i++) {
3688     nnz     = Ii[i+1]- Ii[i];
3689     JJ      = J + Ii[i];
3690     if (nnz < 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Local row %D has a negative %D number of columns",i,nnz);
3691     if (nnz && (JJ[0] < 0)) SETERRRQ1(PETSC_ERR_ARG_WRONGSTATE,"Row %D starts with negative column index",i,j);
3692     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);
3693   }
3694 #endif
3695 
3696   for (i=0; i<m; i++) {
3697     nnz     = Ii[i+1]- Ii[i];
3698     JJ      = J + Ii[i];
3699     nnz_max = PetscMax(nnz_max,nnz);
3700     d       = 0;
3701     for (j=0; j<nnz; j++) {
3702       if (cstart <= JJ[j] && JJ[j] < cend) d++;
3703     }
3704     d_nnz[i] = d;
3705     o_nnz[i] = nnz - d;
3706   }
3707   ierr = MatMPIAIJSetPreallocation(B,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
3708   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
3709 
3710   if (v) values = (PetscScalar*)v;
3711   else {
3712     ierr = PetscMalloc((nnz_max+1)*sizeof(PetscScalar),&values);CHKERRQ(ierr);
3713     ierr = PetscMemzero(values,nnz_max*sizeof(PetscScalar));CHKERRQ(ierr);
3714   }
3715 
3716   for (i=0; i<m; i++) {
3717     ii   = i + rstart;
3718     nnz  = Ii[i+1]- Ii[i];
3719     ierr = MatSetValues_MPIAIJ(B,1,&ii,nnz,J+Ii[i],values+(v ? Ii[i] : 0),INSERT_VALUES);CHKERRQ(ierr);
3720   }
3721   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3722   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
3723 
3724   if (!v) {
3725     ierr = PetscFree(values);CHKERRQ(ierr);
3726   }
3727   ierr = MatSetOption(B,MAT_NEW_NONZERO_LOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
3728   PetscFunctionReturn(0);
3729 }
3730 EXTERN_C_END
3731 
3732 #undef __FUNCT__
3733 #define __FUNCT__ "MatMPIAIJSetPreallocationCSR"
3734 /*@
3735    MatMPIAIJSetPreallocationCSR - Allocates memory for a sparse parallel matrix in AIJ format
3736    (the default parallel PETSc format).
3737 
3738    Collective on MPI_Comm
3739 
3740    Input Parameters:
3741 +  B - the matrix
3742 .  i - the indices into j for the start of each local row (starts with zero)
3743 .  j - the column indices for each local row (starts with zero)
3744 -  v - optional values in the matrix
3745 
3746    Level: developer
3747 
3748    Notes:
3749        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3750      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3751      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3752 
3753        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3754 
3755        The format which is used for the sparse matrix input, is equivalent to a
3756     row-major ordering.. i.e for the following matrix, the input data expected is
3757     as shown:
3758 
3759         1 0 0
3760         2 0 3     P0
3761        -------
3762         4 5 6     P1
3763 
3764      Process0 [P0]: rows_owned=[0,1]
3765         i =  {0,1,3}  [size = nrow+1  = 2+1]
3766         j =  {0,0,2}  [size = nz = 6]
3767         v =  {1,2,3}  [size = nz = 6]
3768 
3769      Process1 [P1]: rows_owned=[2]
3770         i =  {0,3}    [size = nrow+1  = 1+1]
3771         j =  {0,1,2}  [size = nz = 6]
3772         v =  {4,5,6}  [size = nz = 6]
3773 
3774 .keywords: matrix, aij, compressed row, sparse, parallel
3775 
3776 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatCreateAIJ(), MPIAIJ,
3777           MatCreateSeqAIJWithArrays(), MatCreateMPIAIJWithSplitArrays()
3778 @*/
3779 PetscErrorCode  MatMPIAIJSetPreallocationCSR(Mat B,const PetscInt i[],const PetscInt j[], const PetscScalar v[])
3780 {
3781   PetscErrorCode ierr;
3782 
3783   PetscFunctionBegin;
3784   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocationCSR_C",(Mat,const PetscInt[],const PetscInt[],const PetscScalar[]),(B,i,j,v));CHKERRQ(ierr);
3785   PetscFunctionReturn(0);
3786 }
3787 
3788 #undef __FUNCT__
3789 #define __FUNCT__ "MatMPIAIJSetPreallocation"
3790 /*@C
3791    MatMPIAIJSetPreallocation - Preallocates memory for a sparse parallel matrix in AIJ format
3792    (the default parallel PETSc format).  For good matrix assembly performance
3793    the user should preallocate the matrix storage by setting the parameters
3794    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
3795    performance can be increased by more than a factor of 50.
3796 
3797    Collective on MPI_Comm
3798 
3799    Input Parameters:
3800 +  A - the matrix
3801 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
3802            (same value is used for all local rows)
3803 .  d_nnz - array containing the number of nonzeros in the various rows of the
3804            DIAGONAL portion of the local submatrix (possibly different for each row)
3805            or PETSC_NULL, if d_nz is used to specify the nonzero structure.
3806            The size of this array is equal to the number of local rows, i.e 'm'.
3807            For matrices that will be factored, you must leave room for (and set)
3808            the diagonal entry even if it is zero.
3809 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
3810            submatrix (same value is used for all local rows).
3811 -  o_nnz - array containing the number of nonzeros in the various rows of the
3812            OFF-DIAGONAL portion of the local submatrix (possibly different for
3813            each row) or PETSC_NULL, if o_nz is used to specify the nonzero
3814            structure. The size of this array is equal to the number
3815            of local rows, i.e 'm'.
3816 
3817    If the *_nnz parameter is given then the *_nz parameter is ignored
3818 
3819    The AIJ format (also called the Yale sparse matrix format or
3820    compressed row storage (CSR)), is fully compatible with standard Fortran 77
3821    storage.  The stored row and column indices begin with zero.
3822    See the <A href="../../docs/manual.pdf#nameddest=ch_mat">Mat chapter of the users manual</A> for details.
3823 
3824    The parallel matrix is partitioned such that the first m0 rows belong to
3825    process 0, the next m1 rows belong to process 1, the next m2 rows belong
3826    to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
3827 
3828    The DIAGONAL portion of the local submatrix of a processor can be defined
3829    as the submatrix which is obtained by extraction the part corresponding to
3830    the rows r1-r2 and columns c1-c2 of the global matrix, where r1 is the
3831    first row that belongs to the processor, r2 is the last row belonging to
3832    the this processor, and c1-c2 is range of indices of the local part of a
3833    vector suitable for applying the matrix to.  This is an mxn matrix.  In the
3834    common case of a square matrix, the row and column ranges are the same and
3835    the DIAGONAL part is also square. The remaining portion of the local
3836    submatrix (mxN) constitute the OFF-DIAGONAL portion.
3837 
3838    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
3839 
3840    You can call MatGetInfo() to get information on how effective the preallocation was;
3841    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3842    You can also run with the option -info and look for messages with the string
3843    malloc in them to see if additional memory allocation was needed.
3844 
3845    Example usage:
3846 
3847    Consider the following 8x8 matrix with 34 non-zero values, that is
3848    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
3849    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
3850    as follows:
3851 
3852 .vb
3853             1  2  0  |  0  3  0  |  0  4
3854     Proc0   0  5  6  |  7  0  0  |  8  0
3855             9  0 10  | 11  0  0  | 12  0
3856     -------------------------------------
3857            13  0 14  | 15 16 17  |  0  0
3858     Proc1   0 18  0  | 19 20 21  |  0  0
3859             0  0  0  | 22 23  0  | 24  0
3860     -------------------------------------
3861     Proc2  25 26 27  |  0  0 28  | 29  0
3862            30  0  0  | 31 32 33  |  0 34
3863 .ve
3864 
3865    This can be represented as a collection of submatrices as:
3866 
3867 .vb
3868       A B C
3869       D E F
3870       G H I
3871 .ve
3872 
3873    Where the submatrices A,B,C are owned by proc0, D,E,F are
3874    owned by proc1, G,H,I are owned by proc2.
3875 
3876    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3877    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
3878    The 'M','N' parameters are 8,8, and have the same values on all procs.
3879 
3880    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
3881    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
3882    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
3883    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
3884    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
3885    matrix, ans [DF] as another SeqAIJ matrix.
3886 
3887    When d_nz, o_nz parameters are specified, d_nz storage elements are
3888    allocated for every row of the local diagonal submatrix, and o_nz
3889    storage locations are allocated for every row of the OFF-DIAGONAL submat.
3890    One way to choose d_nz and o_nz is to use the max nonzerors per local
3891    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
3892    In this case, the values of d_nz,o_nz are:
3893 .vb
3894      proc0 : dnz = 2, o_nz = 2
3895      proc1 : dnz = 3, o_nz = 2
3896      proc2 : dnz = 1, o_nz = 4
3897 .ve
3898    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
3899    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
3900    for proc3. i.e we are using 12+15+10=37 storage locations to store
3901    34 values.
3902 
3903    When d_nnz, o_nnz parameters are specified, the storage is specified
3904    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
3905    In the above case the values for d_nnz,o_nnz are:
3906 .vb
3907      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
3908      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
3909      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
3910 .ve
3911    Here the space allocated is sum of all the above values i.e 34, and
3912    hence pre-allocation is perfect.
3913 
3914    Level: intermediate
3915 
3916 .keywords: matrix, aij, compressed row, sparse, parallel
3917 
3918 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatCreateAIJ(), MatMPIAIJSetPreallocationCSR(),
3919           MPIAIJ, MatGetInfo()
3920 @*/
3921 PetscErrorCode  MatMPIAIJSetPreallocation(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])
3922 {
3923   PetscErrorCode ierr;
3924 
3925   PetscFunctionBegin;
3926   PetscValidHeaderSpecific(B,MAT_CLASSID,1);
3927   PetscValidType(B,1);
3928   ierr = PetscTryMethod(B,"MatMPIAIJSetPreallocation_C",(Mat,PetscInt,const PetscInt[],PetscInt,const PetscInt[]),(B,d_nz,d_nnz,o_nz,o_nnz));CHKERRQ(ierr);
3929   PetscFunctionReturn(0);
3930 }
3931 
3932 #undef __FUNCT__
3933 #define __FUNCT__ "MatCreateMPIAIJWithArrays"
3934 /*@
3935      MatCreateMPIAIJWithArrays - creates a MPI AIJ matrix using arrays that contain in standard
3936          CSR format the local rows.
3937 
3938    Collective on MPI_Comm
3939 
3940    Input Parameters:
3941 +  comm - MPI communicator
3942 .  m - number of local rows (Cannot be PETSC_DECIDE)
3943 .  n - This value should be the same as the local size used in creating the
3944        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
3945        calculated if N is given) For square matrices n is almost always m.
3946 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
3947 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
3948 .   i - row indices
3949 .   j - column indices
3950 -   a - matrix values
3951 
3952    Output Parameter:
3953 .   mat - the matrix
3954 
3955    Level: intermediate
3956 
3957    Notes:
3958        The i, j, and a arrays ARE copied by this routine into the internal format used by PETSc;
3959      thus you CANNOT change the matrix entries by changing the values of a[] after you have
3960      called this routine. Use MatCreateMPIAIJWithSplitArrays() to avoid needing to copy the arrays.
3961 
3962        The i and j indices are 0 based, and i indices are indices corresponding to the local j array.
3963 
3964        The format which is used for the sparse matrix input, is equivalent to a
3965     row-major ordering.. i.e for the following matrix, the input data expected is
3966     as shown:
3967 
3968         1 0 0
3969         2 0 3     P0
3970        -------
3971         4 5 6     P1
3972 
3973      Process0 [P0]: rows_owned=[0,1]
3974         i =  {0,1,3}  [size = nrow+1  = 2+1]
3975         j =  {0,0,2}  [size = nz = 6]
3976         v =  {1,2,3}  [size = nz = 6]
3977 
3978      Process1 [P1]: rows_owned=[2]
3979         i =  {0,3}    [size = nrow+1  = 1+1]
3980         j =  {0,1,2}  [size = nz = 6]
3981         v =  {4,5,6}  [size = nz = 6]
3982 
3983 .keywords: matrix, aij, compressed row, sparse, parallel
3984 
3985 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
3986           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithSplitArrays()
3987 @*/
3988 PetscErrorCode  MatCreateMPIAIJWithArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,const PetscInt i[],const PetscInt j[],const PetscScalar a[],Mat *mat)
3989 {
3990   PetscErrorCode ierr;
3991 
3992   PetscFunctionBegin;
3993   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
3994   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
3995   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
3996   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
3997   /* ierr = MatSetBlockSizes(M,bs,cbs); CHKERRQ(ierr); */
3998   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
3999   ierr = MatMPIAIJSetPreallocationCSR(*mat,i,j,a);CHKERRQ(ierr);
4000   PetscFunctionReturn(0);
4001 }
4002 
4003 #undef __FUNCT__
4004 #define __FUNCT__ "MatCreateAIJ"
4005 /*@C
4006    MatCreateAIJ - Creates a sparse parallel matrix in AIJ format
4007    (the default parallel PETSc format).  For good matrix assembly performance
4008    the user should preallocate the matrix storage by setting the parameters
4009    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
4010    performance can be increased by more than a factor of 50.
4011 
4012    Collective on MPI_Comm
4013 
4014    Input Parameters:
4015 +  comm - MPI communicator
4016 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
4017            This value should be the same as the local size used in creating the
4018            y vector for the matrix-vector product y = Ax.
4019 .  n - This value should be the same as the local size used in creating the
4020        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
4021        calculated if N is given) For square matrices n is almost always m.
4022 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
4023 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
4024 .  d_nz  - number of nonzeros per row in DIAGONAL portion of local submatrix
4025            (same value is used for all local rows)
4026 .  d_nnz - array containing the number of nonzeros in the various rows of the
4027            DIAGONAL portion of the local submatrix (possibly different for each row)
4028            or PETSC_NULL, if d_nz is used to specify the nonzero structure.
4029            The size of this array is equal to the number of local rows, i.e 'm'.
4030 .  o_nz  - number of nonzeros per row in the OFF-DIAGONAL portion of local
4031            submatrix (same value is used for all local rows).
4032 -  o_nnz - array containing the number of nonzeros in the various rows of the
4033            OFF-DIAGONAL portion of the local submatrix (possibly different for
4034            each row) or PETSC_NULL, if o_nz is used to specify the nonzero
4035            structure. The size of this array is equal to the number
4036            of local rows, i.e 'm'.
4037 
4038    Output Parameter:
4039 .  A - the matrix
4040 
4041    It is recommended that one use the MatCreate(), MatSetType() and/or MatSetFromOptions(),
4042    MatXXXXSetPreallocation() paradgm instead of this routine directly.
4043    [MatXXXXSetPreallocation() is, for example, MatSeqAIJSetPreallocation]
4044 
4045    Notes:
4046    If the *_nnz parameter is given then the *_nz parameter is ignored
4047 
4048    m,n,M,N parameters specify the size of the matrix, and its partitioning across
4049    processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
4050    storage requirements for this matrix.
4051 
4052    If PETSC_DECIDE or  PETSC_DETERMINE is used for a particular argument on one
4053    processor than it must be used on all processors that share the object for
4054    that argument.
4055 
4056    The user MUST specify either the local or global matrix dimensions
4057    (possibly both).
4058 
4059    The parallel matrix is partitioned across processors such that the
4060    first m0 rows belong to process 0, the next m1 rows belong to
4061    process 1, the next m2 rows belong to process 2 etc.. where
4062    m0,m1,m2,.. are the input parameter 'm'. i.e each processor stores
4063    values corresponding to [m x N] submatrix.
4064 
4065    The columns are logically partitioned with the n0 columns belonging
4066    to 0th partition, the next n1 columns belonging to the next
4067    partition etc.. where n0,n1,n2... are the the input parameter 'n'.
4068 
4069    The DIAGONAL portion of the local submatrix on any given processor
4070    is the submatrix corresponding to the rows and columns m,n
4071    corresponding to the given processor. i.e diagonal matrix on
4072    process 0 is [m0 x n0], diagonal matrix on process 1 is [m1 x n1]
4073    etc. The remaining portion of the local submatrix [m x (N-n)]
4074    constitute the OFF-DIAGONAL portion. The example below better
4075    illustrates this concept.
4076 
4077    For a square global matrix we define each processor's diagonal portion
4078    to be its local rows and the corresponding columns (a square submatrix);
4079    each processor's off-diagonal portion encompasses the remainder of the
4080    local matrix (a rectangular submatrix).
4081 
4082    If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
4083 
4084    When calling this routine with a single process communicator, a matrix of
4085    type SEQAIJ is returned.  If a matrix of type MPIAIJ is desired for this
4086    type of communicator, use the construction mechanism:
4087      MatCreate(...,&A); MatSetType(A,MATMPIAIJ); MatSetSizes(A, m,n,M,N); MatMPIAIJSetPreallocation(A,...);
4088 
4089    By default, this format uses inodes (identical nodes) when possible.
4090    We search for consecutive rows with the same nonzero structure, thereby
4091    reusing matrix information to achieve increased efficiency.
4092 
4093    Options Database Keys:
4094 +  -mat_no_inode  - Do not use inodes
4095 .  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
4096 -  -mat_aij_oneindex - Internally use indexing starting at 1
4097         rather than 0.  Note that when calling MatSetValues(),
4098         the user still MUST index entries starting at 0!
4099 
4100 
4101    Example usage:
4102 
4103    Consider the following 8x8 matrix with 34 non-zero values, that is
4104    assembled across 3 processors. Lets assume that proc0 owns 3 rows,
4105    proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
4106    as follows:
4107 
4108 .vb
4109             1  2  0  |  0  3  0  |  0  4
4110     Proc0   0  5  6  |  7  0  0  |  8  0
4111             9  0 10  | 11  0  0  | 12  0
4112     -------------------------------------
4113            13  0 14  | 15 16 17  |  0  0
4114     Proc1   0 18  0  | 19 20 21  |  0  0
4115             0  0  0  | 22 23  0  | 24  0
4116     -------------------------------------
4117     Proc2  25 26 27  |  0  0 28  | 29  0
4118            30  0  0  | 31 32 33  |  0 34
4119 .ve
4120 
4121    This can be represented as a collection of submatrices as:
4122 
4123 .vb
4124       A B C
4125       D E F
4126       G H I
4127 .ve
4128 
4129    Where the submatrices A,B,C are owned by proc0, D,E,F are
4130    owned by proc1, G,H,I are owned by proc2.
4131 
4132    The 'm' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4133    The 'n' parameters for proc0,proc1,proc2 are 3,3,2 respectively.
4134    The 'M','N' parameters are 8,8, and have the same values on all procs.
4135 
4136    The DIAGONAL submatrices corresponding to proc0,proc1,proc2 are
4137    submatrices [A], [E], [I] respectively. The OFF-DIAGONAL submatrices
4138    corresponding to proc0,proc1,proc2 are [BC], [DF], [GH] respectively.
4139    Internally, each processor stores the DIAGONAL part, and the OFF-DIAGONAL
4140    part as SeqAIJ matrices. for eg: proc1 will store [E] as a SeqAIJ
4141    matrix, ans [DF] as another SeqAIJ matrix.
4142 
4143    When d_nz, o_nz parameters are specified, d_nz storage elements are
4144    allocated for every row of the local diagonal submatrix, and o_nz
4145    storage locations are allocated for every row of the OFF-DIAGONAL submat.
4146    One way to choose d_nz and o_nz is to use the max nonzerors per local
4147    rows for each of the local DIAGONAL, and the OFF-DIAGONAL submatrices.
4148    In this case, the values of d_nz,o_nz are:
4149 .vb
4150      proc0 : dnz = 2, o_nz = 2
4151      proc1 : dnz = 3, o_nz = 2
4152      proc2 : dnz = 1, o_nz = 4
4153 .ve
4154    We are allocating m*(d_nz+o_nz) storage locations for every proc. This
4155    translates to 3*(2+2)=12 for proc0, 3*(3+2)=15 for proc1, 2*(1+4)=10
4156    for proc3. i.e we are using 12+15+10=37 storage locations to store
4157    34 values.
4158 
4159    When d_nnz, o_nnz parameters are specified, the storage is specified
4160    for every row, coresponding to both DIAGONAL and OFF-DIAGONAL submatrices.
4161    In the above case the values for d_nnz,o_nnz are:
4162 .vb
4163      proc0: d_nnz = [2,2,2] and o_nnz = [2,2,2]
4164      proc1: d_nnz = [3,3,2] and o_nnz = [2,1,1]
4165      proc2: d_nnz = [1,1]   and o_nnz = [4,4]
4166 .ve
4167    Here the space allocated is sum of all the above values i.e 34, and
4168    hence pre-allocation is perfect.
4169 
4170    Level: intermediate
4171 
4172 .keywords: matrix, aij, compressed row, sparse, parallel
4173 
4174 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
4175           MPIAIJ, MatCreateMPIAIJWithArrays()
4176 @*/
4177 PetscErrorCode  MatCreateAIJ(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[],Mat *A)
4178 {
4179   PetscErrorCode ierr;
4180   PetscMPIInt    size;
4181 
4182   PetscFunctionBegin;
4183   ierr = MatCreate(comm,A);CHKERRQ(ierr);
4184   ierr = MatSetSizes(*A,m,n,M,N);CHKERRQ(ierr);
4185   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4186   if (size > 1) {
4187     ierr = MatSetType(*A,MATMPIAIJ);CHKERRQ(ierr);
4188     ierr = MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);CHKERRQ(ierr);
4189   } else {
4190     ierr = MatSetType(*A,MATSEQAIJ);CHKERRQ(ierr);
4191     ierr = MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);CHKERRQ(ierr);
4192   }
4193   PetscFunctionReturn(0);
4194 }
4195 
4196 #undef __FUNCT__
4197 #define __FUNCT__ "MatMPIAIJGetSeqAIJ"
4198 PetscErrorCode  MatMPIAIJGetSeqAIJ(Mat A,Mat *Ad,Mat *Ao,PetscInt *colmap[])
4199 {
4200   Mat_MPIAIJ *a = (Mat_MPIAIJ *)A->data;
4201 
4202   PetscFunctionBegin;
4203   *Ad     = a->A;
4204   *Ao     = a->B;
4205   *colmap = a->garray;
4206   PetscFunctionReturn(0);
4207 }
4208 
4209 #undef __FUNCT__
4210 #define __FUNCT__ "MatSetColoring_MPIAIJ"
4211 PetscErrorCode MatSetColoring_MPIAIJ(Mat A,ISColoring coloring)
4212 {
4213   PetscErrorCode ierr;
4214   PetscInt       i;
4215   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4216 
4217   PetscFunctionBegin;
4218   if (coloring->ctype == IS_COLORING_GLOBAL) {
4219     ISColoringValue *allcolors,*colors;
4220     ISColoring      ocoloring;
4221 
4222     /* set coloring for diagonal portion */
4223     ierr = MatSetColoring_SeqAIJ(a->A,coloring);CHKERRQ(ierr);
4224 
4225     /* set coloring for off-diagonal portion */
4226     ierr = ISAllGatherColors(((PetscObject)A)->comm,coloring->n,coloring->colors,PETSC_NULL,&allcolors);CHKERRQ(ierr);
4227     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
4228     for (i=0; i<a->B->cmap->n; i++) {
4229       colors[i] = allcolors[a->garray[i]];
4230     }
4231     ierr = PetscFree(allcolors);CHKERRQ(ierr);
4232     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4233     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4234     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4235   } else if (coloring->ctype == IS_COLORING_GHOSTED) {
4236     ISColoringValue *colors;
4237     PetscInt        *larray;
4238     ISColoring      ocoloring;
4239 
4240     /* set coloring for diagonal portion */
4241     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
4242     for (i=0; i<a->A->cmap->n; i++) {
4243       larray[i] = i + A->cmap->rstart;
4244     }
4245     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->A->cmap->n,larray,PETSC_NULL,larray);CHKERRQ(ierr);
4246     ierr = PetscMalloc((a->A->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
4247     for (i=0; i<a->A->cmap->n; i++) {
4248       colors[i] = coloring->colors[larray[i]];
4249     }
4250     ierr = PetscFree(larray);CHKERRQ(ierr);
4251     ierr = ISColoringCreate(PETSC_COMM_SELF,coloring->n,a->A->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4252     ierr = MatSetColoring_SeqAIJ(a->A,ocoloring);CHKERRQ(ierr);
4253     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4254 
4255     /* set coloring for off-diagonal portion */
4256     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(PetscInt),&larray);CHKERRQ(ierr);
4257     ierr = ISGlobalToLocalMappingApply(A->cmap->mapping,IS_GTOLM_MASK,a->B->cmap->n,a->garray,PETSC_NULL,larray);CHKERRQ(ierr);
4258     ierr = PetscMalloc((a->B->cmap->n+1)*sizeof(ISColoringValue),&colors);CHKERRQ(ierr);
4259     for (i=0; i<a->B->cmap->n; i++) {
4260       colors[i] = coloring->colors[larray[i]];
4261     }
4262     ierr = PetscFree(larray);CHKERRQ(ierr);
4263     ierr = ISColoringCreate(MPI_COMM_SELF,coloring->n,a->B->cmap->n,colors,&ocoloring);CHKERRQ(ierr);
4264     ierr = MatSetColoring_SeqAIJ(a->B,ocoloring);CHKERRQ(ierr);
4265     ierr = ISColoringDestroy(&ocoloring);CHKERRQ(ierr);
4266   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support ISColoringType %d",(int)coloring->ctype);
4267 
4268   PetscFunctionReturn(0);
4269 }
4270 
4271 #if defined(PETSC_HAVE_ADIC)
4272 #undef __FUNCT__
4273 #define __FUNCT__ "MatSetValuesAdic_MPIAIJ"
4274 PetscErrorCode MatSetValuesAdic_MPIAIJ(Mat A,void *advalues)
4275 {
4276   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4277   PetscErrorCode ierr;
4278 
4279   PetscFunctionBegin;
4280   ierr = MatSetValuesAdic_SeqAIJ(a->A,advalues);CHKERRQ(ierr);
4281   ierr = MatSetValuesAdic_SeqAIJ(a->B,advalues);CHKERRQ(ierr);
4282   PetscFunctionReturn(0);
4283 }
4284 #endif
4285 
4286 #undef __FUNCT__
4287 #define __FUNCT__ "MatSetValuesAdifor_MPIAIJ"
4288 PetscErrorCode MatSetValuesAdifor_MPIAIJ(Mat A,PetscInt nl,void *advalues)
4289 {
4290   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
4291   PetscErrorCode ierr;
4292 
4293   PetscFunctionBegin;
4294   ierr = MatSetValuesAdifor_SeqAIJ(a->A,nl,advalues);CHKERRQ(ierr);
4295   ierr = MatSetValuesAdifor_SeqAIJ(a->B,nl,advalues);CHKERRQ(ierr);
4296   PetscFunctionReturn(0);
4297 }
4298 
4299 #undef __FUNCT__
4300 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJSymbolic"
4301 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJSymbolic(MPI_Comm comm,Mat inmat,PetscInt n,Mat *outmat)
4302 {
4303   PetscErrorCode ierr;
4304   PetscInt       m,N,i,rstart,nnz,*dnz,*onz,sum,bs,cbs;
4305   PetscInt       *indx;
4306 
4307   PetscFunctionBegin;
4308   /* This routine will ONLY return MPIAIJ type matrix */
4309   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4310   ierr = MatGetBlockSizes(inmat,&bs,&cbs);CHKERRQ(ierr);
4311   if (n == PETSC_DECIDE){
4312     ierr = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
4313   }
4314   /* Check sum(n) = N */
4315   ierr = MPI_Allreduce(&n,&sum,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4316   if (sum != N) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Sum of local columns != global columns %d",N);
4317 
4318   ierr = MPI_Scan(&m, &rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRQ(ierr);
4319   rstart -= m;
4320 
4321   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4322   for (i=0;i<m;i++) {
4323     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,PETSC_NULL);CHKERRQ(ierr);
4324     ierr = MatPreallocateSet(i+rstart,nnz,indx,dnz,onz);CHKERRQ(ierr);
4325     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,PETSC_NULL);CHKERRQ(ierr);
4326   }
4327 
4328   ierr = MatCreate(comm,outmat);CHKERRQ(ierr);
4329   ierr = MatSetSizes(*outmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE); CHKERRQ(ierr);
4330   ierr = MatSetBlockSizes(*outmat,bs,cbs); CHKERRQ(ierr);
4331   ierr = MatSetType(*outmat,MATMPIAIJ);  CHKERRQ(ierr);
4332   ierr = MatMPIAIJSetPreallocation(*outmat,0,dnz,0,onz);CHKERRQ(ierr);
4333   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4334   PetscFunctionReturn(0);
4335 }
4336 
4337 #undef __FUNCT__
4338 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJNumeric"
4339 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJNumeric(MPI_Comm comm,Mat inmat,PetscInt n,Mat outmat)
4340 {
4341   PetscErrorCode ierr;
4342   PetscInt       m,N,i,rstart,nnz,Ii;
4343   PetscInt       *indx;
4344   PetscScalar    *values;
4345 
4346   PetscFunctionBegin;
4347   ierr = MatGetSize(inmat,&m,&N);CHKERRQ(ierr);
4348   ierr = MatGetOwnershipRange(outmat,&rstart,PETSC_NULL);CHKERRQ(ierr);
4349   for (i=0;i<m;i++) {
4350     ierr = MatGetRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4351     Ii    = i + rstart;
4352     ierr = MatSetValues_MPIAIJ(outmat,1,&Ii,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4353     ierr = MatRestoreRow_SeqAIJ(inmat,i,&nnz,&indx,&values);CHKERRQ(ierr);
4354   }
4355   ierr = MatAssemblyBegin(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4356   ierr = MatAssemblyEnd(outmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4357   PetscFunctionReturn(0);
4358 }
4359 
4360 #undef __FUNCT__
4361 #define __FUNCT__ "MatCreateMPIAIJConcatenateSeqAIJ"
4362 /*@
4363       MatCreateMPIAIJConcatenateSeqAIJ - Creates a single large PETSc matrix by concatenating sequential
4364                  matrices from each processor
4365 
4366     Collective on MPI_Comm
4367 
4368    Input Parameters:
4369 +    comm - the communicators the parallel matrix will live on
4370 .    inmat - the input sequential matrices
4371 .    n - number of local columns (or PETSC_DECIDE)
4372 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4373 
4374    Output Parameter:
4375 .    outmat - the parallel matrix generated
4376 
4377     Level: advanced
4378 
4379    Notes: The number of columns of the matrix in EACH processor MUST be the same.
4380 
4381 @*/
4382 PetscErrorCode  MatCreateMPIAIJConcatenateSeqAIJ(MPI_Comm comm,Mat inmat,PetscInt n,MatReuse scall,Mat *outmat)
4383 {
4384   PetscErrorCode ierr;
4385 
4386   PetscFunctionBegin;
4387   ierr = PetscLogEventBegin(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4388   if (scall == MAT_INITIAL_MATRIX){
4389     ierr = MatCreateMPIAIJConcatenateSeqAIJSymbolic(comm,inmat,n,outmat);CHKERRQ(ierr);
4390   }
4391   ierr = MatCreateMPIAIJConcatenateSeqAIJNumeric(comm,inmat,n,*outmat);CHKERRQ(ierr);
4392   ierr = PetscLogEventEnd(MAT_Merge,inmat,0,0,0);CHKERRQ(ierr);
4393   PetscFunctionReturn(0);
4394 }
4395 
4396 #undef __FUNCT__
4397 #define __FUNCT__ "MatFileSplit"
4398 PetscErrorCode MatFileSplit(Mat A,char *outfile)
4399 {
4400   PetscErrorCode    ierr;
4401   PetscMPIInt       rank;
4402   PetscInt          m,N,i,rstart,nnz;
4403   size_t            len;
4404   const PetscInt    *indx;
4405   PetscViewer       out;
4406   char              *name;
4407   Mat               B;
4408   const PetscScalar *values;
4409 
4410   PetscFunctionBegin;
4411   ierr = MatGetLocalSize(A,&m,0);CHKERRQ(ierr);
4412   ierr = MatGetSize(A,0,&N);CHKERRQ(ierr);
4413   /* Should this be the type of the diagonal block of A? */
4414   ierr = MatCreate(PETSC_COMM_SELF,&B);CHKERRQ(ierr);
4415   ierr = MatSetSizes(B,m,N,m,N);CHKERRQ(ierr);
4416   ierr = MatSetBlockSizes(B,A->rmap->bs,A->cmap->bs);CHKERRQ(ierr);
4417   ierr = MatSetType(B,MATSEQAIJ);CHKERRQ(ierr);
4418   ierr = MatSeqAIJSetPreallocation(B,0,PETSC_NULL);CHKERRQ(ierr);
4419   ierr = MatGetOwnershipRange(A,&rstart,0);CHKERRQ(ierr);
4420   for (i=0;i<m;i++) {
4421     ierr = MatGetRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4422     ierr = MatSetValues(B,1,&i,nnz,indx,values,INSERT_VALUES);CHKERRQ(ierr);
4423     ierr = MatRestoreRow(A,i+rstart,&nnz,&indx,&values);CHKERRQ(ierr);
4424   }
4425   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4426   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4427 
4428   ierr = MPI_Comm_rank(((PetscObject)A)->comm,&rank);CHKERRQ(ierr);
4429   ierr = PetscStrlen(outfile,&len);CHKERRQ(ierr);
4430   ierr = PetscMalloc((len+5)*sizeof(char),&name);CHKERRQ(ierr);
4431   sprintf(name,"%s.%d",outfile,rank);
4432   ierr = PetscViewerBinaryOpen(PETSC_COMM_SELF,name,FILE_MODE_APPEND,&out);CHKERRQ(ierr);
4433   ierr = PetscFree(name);
4434   ierr = MatView(B,out);CHKERRQ(ierr);
4435   ierr = PetscViewerDestroy(&out);CHKERRQ(ierr);
4436   ierr = MatDestroy(&B);CHKERRQ(ierr);
4437   PetscFunctionReturn(0);
4438 }
4439 
4440 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
4441 #undef __FUNCT__
4442 #define __FUNCT__ "MatDestroy_MPIAIJ_SeqsToMPI"
4443 PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat A)
4444 {
4445   PetscErrorCode       ierr;
4446   Mat_Merge_SeqsToMPI  *merge;
4447   PetscContainer       container;
4448 
4449   PetscFunctionBegin;
4450   ierr = PetscObjectQuery((PetscObject)A,"MatMergeSeqsToMPI",(PetscObject *)&container);CHKERRQ(ierr);
4451   if (container) {
4452     ierr = PetscContainerGetPointer(container,(void **)&merge);CHKERRQ(ierr);
4453     ierr = PetscFree(merge->id_r);CHKERRQ(ierr);
4454     ierr = PetscFree(merge->len_s);CHKERRQ(ierr);
4455     ierr = PetscFree(merge->len_r);CHKERRQ(ierr);
4456     ierr = PetscFree(merge->bi);CHKERRQ(ierr);
4457     ierr = PetscFree(merge->bj);CHKERRQ(ierr);
4458     ierr = PetscFree(merge->buf_ri[0]);CHKERRQ(ierr);
4459     ierr = PetscFree(merge->buf_ri);CHKERRQ(ierr);
4460     ierr = PetscFree(merge->buf_rj[0]);CHKERRQ(ierr);
4461     ierr = PetscFree(merge->buf_rj);CHKERRQ(ierr);
4462     ierr = PetscFree(merge->coi);CHKERRQ(ierr);
4463     ierr = PetscFree(merge->coj);CHKERRQ(ierr);
4464     ierr = PetscFree(merge->owners_co);CHKERRQ(ierr);
4465     ierr = PetscLayoutDestroy(&merge->rowmap);CHKERRQ(ierr);
4466     ierr = PetscFree(merge);CHKERRQ(ierr);
4467     ierr = PetscObjectCompose((PetscObject)A,"MatMergeSeqsToMPI",0);CHKERRQ(ierr);
4468   }
4469   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
4470   PetscFunctionReturn(0);
4471 }
4472 
4473 #include <../src/mat/utils/freespace.h>
4474 #include <petscbt.h>
4475 
4476 #undef __FUNCT__
4477 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJNumeric"
4478 PetscErrorCode  MatCreateMPIAIJSumSeqAIJNumeric(Mat seqmat,Mat mpimat)
4479 {
4480   PetscErrorCode       ierr;
4481   MPI_Comm             comm=((PetscObject)mpimat)->comm;
4482   Mat_SeqAIJ           *a=(Mat_SeqAIJ*)seqmat->data;
4483   PetscMPIInt          size,rank,taga,*len_s;
4484   PetscInt             N=mpimat->cmap->N,i,j,*owners,*ai=a->i,*aj=a->j;
4485   PetscInt             proc,m;
4486   PetscInt             **buf_ri,**buf_rj;
4487   PetscInt             k,anzi,*bj_i,*bi,*bj,arow,bnzi,nextaj;
4488   PetscInt             nrows,**buf_ri_k,**nextrow,**nextai;
4489   MPI_Request          *s_waits,*r_waits;
4490   MPI_Status           *status;
4491   MatScalar            *aa=a->a;
4492   MatScalar            **abuf_r,*ba_i;
4493   Mat_Merge_SeqsToMPI  *merge;
4494   PetscContainer       container;
4495 
4496   PetscFunctionBegin;
4497   ierr = PetscLogEventBegin(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4498 
4499   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4500   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4501 
4502   ierr = PetscObjectQuery((PetscObject)mpimat,"MatMergeSeqsToMPI",(PetscObject *)&container);CHKERRQ(ierr);
4503   ierr  = PetscContainerGetPointer(container,(void **)&merge);CHKERRQ(ierr);
4504 
4505   bi     = merge->bi;
4506   bj     = merge->bj;
4507   buf_ri = merge->buf_ri;
4508   buf_rj = merge->buf_rj;
4509 
4510   ierr   = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
4511   owners = merge->rowmap->range;
4512   len_s  = merge->len_s;
4513 
4514   /* send and recv matrix values */
4515   /*-----------------------------*/
4516   ierr = PetscObjectGetNewTag((PetscObject)mpimat,&taga);CHKERRQ(ierr);
4517   ierr = PetscPostIrecvScalar(comm,taga,merge->nrecv,merge->id_r,merge->len_r,&abuf_r,&r_waits);CHKERRQ(ierr);
4518 
4519   ierr = PetscMalloc((merge->nsend+1)*sizeof(MPI_Request),&s_waits);CHKERRQ(ierr);
4520   for (proc=0,k=0; proc<size; proc++){
4521     if (!len_s[proc]) continue;
4522     i = owners[proc];
4523     ierr = MPI_Isend(aa+ai[i],len_s[proc],MPIU_MATSCALAR,proc,taga,comm,s_waits+k);CHKERRQ(ierr);
4524     k++;
4525   }
4526 
4527   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,r_waits,status);CHKERRQ(ierr);}
4528   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,s_waits,status);CHKERRQ(ierr);}
4529   ierr = PetscFree(status);CHKERRQ(ierr);
4530 
4531   ierr = PetscFree(s_waits);CHKERRQ(ierr);
4532   ierr = PetscFree(r_waits);CHKERRQ(ierr);
4533 
4534   /* insert mat values of mpimat */
4535   /*----------------------------*/
4536   ierr = PetscMalloc(N*sizeof(PetscScalar),&ba_i);CHKERRQ(ierr);
4537   ierr = PetscMalloc3(merge->nrecv,PetscInt*,&buf_ri_k,merge->nrecv,PetscInt*,&nextrow,merge->nrecv,PetscInt*,&nextai);CHKERRQ(ierr);
4538 
4539   for (k=0; k<merge->nrecv; k++){
4540     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4541     nrows = *(buf_ri_k[k]);
4542     nextrow[k]  = buf_ri_k[k]+1;  /* next row number of k-th recved i-structure */
4543     nextai[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
4544   }
4545 
4546   /* set values of ba */
4547   m = merge->rowmap->n;
4548   for (i=0; i<m; i++) {
4549     arow = owners[rank] + i;
4550     bj_i = bj+bi[i];  /* col indices of the i-th row of mpimat */
4551     bnzi = bi[i+1] - bi[i];
4552     ierr = PetscMemzero(ba_i,bnzi*sizeof(PetscScalar));CHKERRQ(ierr);
4553 
4554     /* add local non-zero vals of this proc's seqmat into ba */
4555     anzi = ai[arow+1] - ai[arow];
4556     aj   = a->j + ai[arow];
4557     aa   = a->a + ai[arow];
4558     nextaj = 0;
4559     for (j=0; nextaj<anzi; j++){
4560       if (*(bj_i + j) == aj[nextaj]){ /* bcol == acol */
4561         ba_i[j] += aa[nextaj++];
4562       }
4563     }
4564 
4565     /* add received vals into ba */
4566     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
4567       /* i-th row */
4568       if (i == *nextrow[k]) {
4569         anzi = *(nextai[k]+1) - *nextai[k];
4570         aj   = buf_rj[k] + *(nextai[k]);
4571         aa   = abuf_r[k] + *(nextai[k]);
4572         nextaj = 0;
4573         for (j=0; nextaj<anzi; j++){
4574           if (*(bj_i + j) == aj[nextaj]){ /* bcol == acol */
4575             ba_i[j] += aa[nextaj++];
4576           }
4577         }
4578         nextrow[k]++; nextai[k]++;
4579       }
4580     }
4581     ierr = MatSetValues(mpimat,1,&arow,bnzi,bj_i,ba_i,INSERT_VALUES);CHKERRQ(ierr);
4582   }
4583   ierr = MatAssemblyBegin(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4584   ierr = MatAssemblyEnd(mpimat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
4585 
4586   ierr = PetscFree(abuf_r[0]);CHKERRQ(ierr);
4587   ierr = PetscFree(abuf_r);CHKERRQ(ierr);
4588   ierr = PetscFree(ba_i);CHKERRQ(ierr);
4589   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4590   ierr = PetscLogEventEnd(MAT_Seqstompinum,seqmat,0,0,0);CHKERRQ(ierr);
4591   PetscFunctionReturn(0);
4592 }
4593 
4594 extern PetscErrorCode  MatDestroy_MPIAIJ_SeqsToMPI(Mat);
4595 
4596 #undef __FUNCT__
4597 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJSymbolic"
4598 PetscErrorCode  MatCreateMPIAIJSumSeqAIJSymbolic(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,Mat *mpimat)
4599 {
4600   PetscErrorCode       ierr;
4601   Mat                  B_mpi;
4602   Mat_SeqAIJ           *a=(Mat_SeqAIJ*)seqmat->data;
4603   PetscMPIInt          size,rank,tagi,tagj,*len_s,*len_si,*len_ri;
4604   PetscInt             **buf_rj,**buf_ri,**buf_ri_k;
4605   PetscInt             M=seqmat->rmap->n,N=seqmat->cmap->n,i,*owners,*ai=a->i,*aj=a->j;
4606   PetscInt             len,proc,*dnz,*onz,bs,cbs;
4607   PetscInt             k,anzi,*bi,*bj,*lnk,nlnk,arow,bnzi,nspacedouble=0;
4608   PetscInt             nrows,*buf_s,*buf_si,*buf_si_i,**nextrow,**nextai;
4609   MPI_Request          *si_waits,*sj_waits,*ri_waits,*rj_waits;
4610   MPI_Status           *status;
4611   PetscFreeSpaceList   free_space=PETSC_NULL,current_space=PETSC_NULL;
4612   PetscBT              lnkbt;
4613   Mat_Merge_SeqsToMPI  *merge;
4614   PetscContainer       container;
4615 
4616   PetscFunctionBegin;
4617   ierr = PetscLogEventBegin(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4618 
4619   /* make sure it is a PETSc comm */
4620   ierr = PetscCommDuplicate(comm,&comm,PETSC_NULL);CHKERRQ(ierr);
4621   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4622   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
4623 
4624   ierr = PetscNew(Mat_Merge_SeqsToMPI,&merge);CHKERRQ(ierr);
4625   ierr = PetscMalloc(size*sizeof(MPI_Status),&status);CHKERRQ(ierr);
4626 
4627   /* determine row ownership */
4628   /*---------------------------------------------------------*/
4629   ierr = PetscLayoutCreate(comm,&merge->rowmap);CHKERRQ(ierr);
4630   ierr = PetscLayoutSetLocalSize(merge->rowmap,m);CHKERRQ(ierr);
4631   ierr = PetscLayoutSetSize(merge->rowmap,M);CHKERRQ(ierr);
4632   ierr = PetscLayoutSetBlockSize(merge->rowmap,1);CHKERRQ(ierr);
4633   ierr = PetscLayoutSetUp(merge->rowmap);CHKERRQ(ierr);
4634   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&len_si);CHKERRQ(ierr);
4635   ierr = PetscMalloc(size*sizeof(PetscMPIInt),&merge->len_s);CHKERRQ(ierr);
4636 
4637   m      = merge->rowmap->n;
4638   M      = merge->rowmap->N;
4639   owners = merge->rowmap->range;
4640 
4641   /* determine the number of messages to send, their lengths */
4642   /*---------------------------------------------------------*/
4643   len_s  = merge->len_s;
4644 
4645   len = 0;  /* length of buf_si[] */
4646   merge->nsend = 0;
4647   for (proc=0; proc<size; proc++){
4648     len_si[proc] = 0;
4649     if (proc == rank){
4650       len_s[proc] = 0;
4651     } else {
4652       len_si[proc] = owners[proc+1] - owners[proc] + 1;
4653       len_s[proc] = ai[owners[proc+1]] - ai[owners[proc]]; /* num of rows to be sent to [proc] */
4654     }
4655     if (len_s[proc]) {
4656       merge->nsend++;
4657       nrows = 0;
4658       for (i=owners[proc]; i<owners[proc+1]; i++){
4659         if (ai[i+1] > ai[i]) nrows++;
4660       }
4661       len_si[proc] = 2*(nrows+1);
4662       len += len_si[proc];
4663     }
4664   }
4665 
4666   /* determine the number and length of messages to receive for ij-structure */
4667   /*-------------------------------------------------------------------------*/
4668   ierr = PetscGatherNumberOfMessages(comm,PETSC_NULL,len_s,&merge->nrecv);CHKERRQ(ierr);
4669   ierr = PetscGatherMessageLengths2(comm,merge->nsend,merge->nrecv,len_s,len_si,&merge->id_r,&merge->len_r,&len_ri);CHKERRQ(ierr);
4670 
4671   /* post the Irecv of j-structure */
4672   /*-------------------------------*/
4673   ierr = PetscCommGetNewTag(comm,&tagj);CHKERRQ(ierr);
4674   ierr = PetscPostIrecvInt(comm,tagj,merge->nrecv,merge->id_r,merge->len_r,&buf_rj,&rj_waits);CHKERRQ(ierr);
4675 
4676   /* post the Isend of j-structure */
4677   /*--------------------------------*/
4678   ierr = PetscMalloc2(merge->nsend,MPI_Request,&si_waits,merge->nsend,MPI_Request,&sj_waits);CHKERRQ(ierr);
4679 
4680   for (proc=0, k=0; proc<size; proc++){
4681     if (!len_s[proc]) continue;
4682     i = owners[proc];
4683     ierr = MPI_Isend(aj+ai[i],len_s[proc],MPIU_INT,proc,tagj,comm,sj_waits+k);CHKERRQ(ierr);
4684     k++;
4685   }
4686 
4687   /* receives and sends of j-structure are complete */
4688   /*------------------------------------------------*/
4689   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,rj_waits,status);CHKERRQ(ierr);}
4690   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,sj_waits,status);CHKERRQ(ierr);}
4691 
4692   /* send and recv i-structure */
4693   /*---------------------------*/
4694   ierr = PetscCommGetNewTag(comm,&tagi);CHKERRQ(ierr);
4695   ierr = PetscPostIrecvInt(comm,tagi,merge->nrecv,merge->id_r,len_ri,&buf_ri,&ri_waits);CHKERRQ(ierr);
4696 
4697   ierr = PetscMalloc((len+1)*sizeof(PetscInt),&buf_s);CHKERRQ(ierr);
4698   buf_si = buf_s;  /* points to the beginning of k-th msg to be sent */
4699   for (proc=0,k=0; proc<size; proc++){
4700     if (!len_s[proc]) continue;
4701     /* form outgoing message for i-structure:
4702          buf_si[0]:                 nrows to be sent
4703                [1:nrows]:           row index (global)
4704                [nrows+1:2*nrows+1]: i-structure index
4705     */
4706     /*-------------------------------------------*/
4707     nrows = len_si[proc]/2 - 1;
4708     buf_si_i    = buf_si + nrows+1;
4709     buf_si[0]   = nrows;
4710     buf_si_i[0] = 0;
4711     nrows = 0;
4712     for (i=owners[proc]; i<owners[proc+1]; i++){
4713       anzi = ai[i+1] - ai[i];
4714       if (anzi) {
4715         buf_si_i[nrows+1] = buf_si_i[nrows] + anzi; /* i-structure */
4716         buf_si[nrows+1] = i-owners[proc]; /* local row index */
4717         nrows++;
4718       }
4719     }
4720     ierr = MPI_Isend(buf_si,len_si[proc],MPIU_INT,proc,tagi,comm,si_waits+k);CHKERRQ(ierr);
4721     k++;
4722     buf_si += len_si[proc];
4723   }
4724 
4725   if (merge->nrecv) {ierr = MPI_Waitall(merge->nrecv,ri_waits,status);CHKERRQ(ierr);}
4726   if (merge->nsend) {ierr = MPI_Waitall(merge->nsend,si_waits,status);CHKERRQ(ierr);}
4727 
4728   ierr = PetscInfo2(seqmat,"nsend: %D, nrecv: %D\n",merge->nsend,merge->nrecv);CHKERRQ(ierr);
4729   for (i=0; i<merge->nrecv; i++){
4730     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);
4731   }
4732 
4733   ierr = PetscFree(len_si);CHKERRQ(ierr);
4734   ierr = PetscFree(len_ri);CHKERRQ(ierr);
4735   ierr = PetscFree(rj_waits);CHKERRQ(ierr);
4736   ierr = PetscFree2(si_waits,sj_waits);CHKERRQ(ierr);
4737   ierr = PetscFree(ri_waits);CHKERRQ(ierr);
4738   ierr = PetscFree(buf_s);CHKERRQ(ierr);
4739   ierr = PetscFree(status);CHKERRQ(ierr);
4740 
4741   /* compute a local seq matrix in each processor */
4742   /*----------------------------------------------*/
4743   /* allocate bi array and free space for accumulating nonzero column info */
4744   ierr = PetscMalloc((m+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
4745   bi[0] = 0;
4746 
4747   /* create and initialize a linked list */
4748   nlnk = N+1;
4749   ierr = PetscLLCreate(N,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4750 
4751   /* initial FreeSpace size is 2*(num of local nnz(seqmat)) */
4752   len = 0;
4753   len  = ai[owners[rank+1]] - ai[owners[rank]];
4754   ierr = PetscFreeSpaceGet((PetscInt)(2*len+1),&free_space);CHKERRQ(ierr);
4755   current_space = free_space;
4756 
4757   /* determine symbolic info for each local row */
4758   ierr = PetscMalloc3(merge->nrecv,PetscInt*,&buf_ri_k,merge->nrecv,PetscInt*,&nextrow,merge->nrecv,PetscInt*,&nextai);CHKERRQ(ierr);
4759 
4760   for (k=0; k<merge->nrecv; k++){
4761     buf_ri_k[k] = buf_ri[k]; /* beginning of k-th recved i-structure */
4762     nrows = *buf_ri_k[k];
4763     nextrow[k]  = buf_ri_k[k] + 1;  /* next row number of k-th recved i-structure */
4764     nextai[k]   = buf_ri_k[k] + (nrows + 1);/* poins to the next i-structure of k-th recved i-structure  */
4765   }
4766 
4767   ierr = MatPreallocateInitialize(comm,m,n,dnz,onz);CHKERRQ(ierr);
4768   len = 0;
4769   for (i=0;i<m;i++) {
4770     bnzi   = 0;
4771     /* add local non-zero cols of this proc's seqmat into lnk */
4772     arow   = owners[rank] + i;
4773     anzi   = ai[arow+1] - ai[arow];
4774     aj     = a->j + ai[arow];
4775     ierr = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4776     bnzi += nlnk;
4777     /* add received col data into lnk */
4778     for (k=0; k<merge->nrecv; k++){ /* k-th received message */
4779       if (i == *nextrow[k]) { /* i-th row */
4780         anzi = *(nextai[k]+1) - *nextai[k];
4781         aj   = buf_rj[k] + *nextai[k];
4782         ierr = PetscLLAddSorted(anzi,aj,N,nlnk,lnk,lnkbt);CHKERRQ(ierr);
4783         bnzi += nlnk;
4784         nextrow[k]++; nextai[k]++;
4785       }
4786     }
4787     if (len < bnzi) len = bnzi;  /* =max(bnzi) */
4788 
4789     /* if free space is not available, make more free space */
4790     if (current_space->local_remaining<bnzi) {
4791       ierr = PetscFreeSpaceGet(bnzi+current_space->total_array_size,&current_space);CHKERRQ(ierr);
4792       nspacedouble++;
4793     }
4794     /* copy data into free space, then initialize lnk */
4795     ierr = PetscLLClean(N,N,bnzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
4796     ierr = MatPreallocateSet(i+owners[rank],bnzi,current_space->array,dnz,onz);CHKERRQ(ierr);
4797 
4798     current_space->array           += bnzi;
4799     current_space->local_used      += bnzi;
4800     current_space->local_remaining -= bnzi;
4801 
4802     bi[i+1] = bi[i] + bnzi;
4803   }
4804 
4805   ierr = PetscFree3(buf_ri_k,nextrow,nextai);CHKERRQ(ierr);
4806 
4807   ierr = PetscMalloc((bi[m]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
4808   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
4809   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
4810 
4811   /* create symbolic parallel matrix B_mpi */
4812   /*---------------------------------------*/
4813     ierr = MatGetBlockSizes(seqmat,&bs,&cbs);CHKERRQ(ierr);
4814   ierr = MatCreate(comm,&B_mpi);CHKERRQ(ierr);
4815   if (n==PETSC_DECIDE) {
4816     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,N);CHKERRQ(ierr);
4817   } else {
4818     ierr = MatSetSizes(B_mpi,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
4819   }
4820   ierr = MatSetBlockSizes(B_mpi,bs,cbs); CHKERRQ(ierr);
4821   ierr = MatSetType(B_mpi,MATMPIAIJ);CHKERRQ(ierr);
4822   ierr = MatMPIAIJSetPreallocation(B_mpi,0,dnz,0,onz);CHKERRQ(ierr);
4823   ierr = MatPreallocateFinalize(dnz,onz);CHKERRQ(ierr);
4824   ierr = MatSetOption(B_mpi,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
4825 
4826   /* B_mpi is not ready for use - assembly will be done by MatCreateMPIAIJSumSeqAIJNumeric() */
4827   B_mpi->assembled     = PETSC_FALSE;
4828   B_mpi->ops->destroy  = MatDestroy_MPIAIJ_SeqsToMPI;
4829   merge->bi            = bi;
4830   merge->bj            = bj;
4831   merge->buf_ri        = buf_ri;
4832   merge->buf_rj        = buf_rj;
4833   merge->coi           = PETSC_NULL;
4834   merge->coj           = PETSC_NULL;
4835   merge->owners_co     = PETSC_NULL;
4836 
4837   ierr = PetscCommDestroy(&comm);CHKERRQ(ierr);
4838 
4839   /* attach the supporting struct to B_mpi for reuse */
4840   ierr = PetscContainerCreate(PETSC_COMM_SELF,&container);CHKERRQ(ierr);
4841   ierr = PetscContainerSetPointer(container,merge);CHKERRQ(ierr);
4842   ierr = PetscObjectCompose((PetscObject)B_mpi,"MatMergeSeqsToMPI",(PetscObject)container);CHKERRQ(ierr);
4843   ierr = PetscContainerDestroy(&container);CHKERRQ(ierr);
4844   *mpimat = B_mpi;
4845 
4846   ierr = PetscLogEventEnd(MAT_Seqstompisym,seqmat,0,0,0);CHKERRQ(ierr);
4847   PetscFunctionReturn(0);
4848 }
4849 
4850 #undef __FUNCT__
4851 #define __FUNCT__ "MatCreateMPIAIJSumSeqAIJ"
4852 /*@C
4853       MatCreateMPIAIJSumSeqAIJ - Creates a MPIAIJ matrix by adding sequential
4854                  matrices from each processor
4855 
4856     Collective on MPI_Comm
4857 
4858    Input Parameters:
4859 +    comm - the communicators the parallel matrix will live on
4860 .    seqmat - the input sequential matrices
4861 .    m - number of local rows (or PETSC_DECIDE)
4862 .    n - number of local columns (or PETSC_DECIDE)
4863 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4864 
4865    Output Parameter:
4866 .    mpimat - the parallel matrix generated
4867 
4868     Level: advanced
4869 
4870    Notes:
4871      The dimensions of the sequential matrix in each processor MUST be the same.
4872      The input seqmat is included into the container "Mat_Merge_SeqsToMPI", and will be
4873      destroyed when mpimat is destroyed. Call PetscObjectQuery() to access seqmat.
4874 @*/
4875 PetscErrorCode  MatCreateMPIAIJSumSeqAIJ(MPI_Comm comm,Mat seqmat,PetscInt m,PetscInt n,MatReuse scall,Mat *mpimat)
4876 {
4877   PetscErrorCode   ierr;
4878   PetscMPIInt     size;
4879 
4880   PetscFunctionBegin;
4881   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
4882   if (size == 1){
4883      ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4884      if (scall == MAT_INITIAL_MATRIX){
4885        ierr = MatDuplicate(seqmat,MAT_COPY_VALUES,mpimat);CHKERRQ(ierr);
4886      } else {
4887        ierr = MatCopy(seqmat,*mpimat,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
4888      }
4889      ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4890      PetscFunctionReturn(0);
4891   }
4892   ierr = PetscLogEventBegin(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4893   if (scall == MAT_INITIAL_MATRIX){
4894     ierr = MatCreateMPIAIJSumSeqAIJSymbolic(comm,seqmat,m,n,mpimat);CHKERRQ(ierr);
4895   }
4896   ierr = MatCreateMPIAIJSumSeqAIJNumeric(seqmat,*mpimat);CHKERRQ(ierr);
4897   ierr = PetscLogEventEnd(MAT_Seqstompi,seqmat,0,0,0);CHKERRQ(ierr);
4898   PetscFunctionReturn(0);
4899 }
4900 
4901 #undef __FUNCT__
4902 #define __FUNCT__ "MatMPIAIJGetLocalMat"
4903 /*@
4904      MatMPIAIJGetLocalMat - Creates a SeqAIJ from a MPIAIJ matrix by taking all its local rows and putting them into a sequential vector with
4905           mlocal rows and n columns. Where mlocal is the row count obtained with MatGetLocalSize() and n is the global column count obtained
4906           with MatGetSize()
4907 
4908     Not Collective
4909 
4910    Input Parameters:
4911 +    A - the matrix
4912 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
4913 
4914    Output Parameter:
4915 .    A_loc - the local sequential matrix generated
4916 
4917     Level: developer
4918 
4919 .seealso: MatGetOwnerShipRange(), MatMPIAIJGetLocalMatCondensed()
4920 
4921 @*/
4922 PetscErrorCode  MatMPIAIJGetLocalMat(Mat A,MatReuse scall,Mat *A_loc)
4923 {
4924   PetscErrorCode  ierr;
4925   Mat_MPIAIJ      *mpimat=(Mat_MPIAIJ*)A->data;
4926   Mat_SeqAIJ      *mat,*a=(Mat_SeqAIJ*)(mpimat->A)->data,*b=(Mat_SeqAIJ*)(mpimat->B)->data;
4927   PetscInt        *ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,*cmap=mpimat->garray;
4928   MatScalar       *aa=a->a,*ba=b->a,*cam;
4929   PetscScalar     *ca;
4930   PetscInt        am=A->rmap->n,i,j,k,cstart=A->cmap->rstart;
4931   PetscInt        *ci,*cj,col,ncols_d,ncols_o,jo;
4932   PetscBool       match;
4933 
4934   PetscFunctionBegin;
4935   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
4936   if (!match) SETERRQ(((PetscObject)A)->comm, PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
4937   ierr = PetscLogEventBegin(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4938   if (scall == MAT_INITIAL_MATRIX){
4939     ierr = PetscMalloc((1+am)*sizeof(PetscInt),&ci);CHKERRQ(ierr);
4940     ci[0] = 0;
4941     for (i=0; i<am; i++){
4942       ci[i+1] = ci[i] + (ai[i+1] - ai[i]) + (bi[i+1] - bi[i]);
4943     }
4944     ierr = PetscMalloc((1+ci[am])*sizeof(PetscInt),&cj);CHKERRQ(ierr);
4945     ierr = PetscMalloc((1+ci[am])*sizeof(PetscScalar),&ca);CHKERRQ(ierr);
4946     k = 0;
4947     for (i=0; i<am; i++) {
4948       ncols_o = bi[i+1] - bi[i];
4949       ncols_d = ai[i+1] - ai[i];
4950       /* off-diagonal portion of A */
4951       for (jo=0; jo<ncols_o; jo++) {
4952         col = cmap[*bj];
4953         if (col >= cstart) break;
4954         cj[k]   = col; bj++;
4955         ca[k++] = *ba++;
4956       }
4957       /* diagonal portion of A */
4958       for (j=0; j<ncols_d; j++) {
4959         cj[k]   = cstart + *aj++;
4960         ca[k++] = *aa++;
4961       }
4962       /* off-diagonal portion of A */
4963       for (j=jo; j<ncols_o; j++) {
4964         cj[k]   = cmap[*bj++];
4965         ca[k++] = *ba++;
4966       }
4967     }
4968     /* put together the new matrix */
4969     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,am,A->cmap->N,ci,cj,ca,A_loc);CHKERRQ(ierr);
4970     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
4971     /* Since these are PETSc arrays, change flags to free them as necessary. */
4972     mat          = (Mat_SeqAIJ*)(*A_loc)->data;
4973     mat->free_a  = PETSC_TRUE;
4974     mat->free_ij = PETSC_TRUE;
4975     mat->nonew   = 0;
4976   } else if (scall == MAT_REUSE_MATRIX){
4977     mat=(Mat_SeqAIJ*)(*A_loc)->data;
4978     ci = mat->i; cj = mat->j; cam = mat->a;
4979     for (i=0; i<am; i++) {
4980       /* off-diagonal portion of A */
4981       ncols_o = bi[i+1] - bi[i];
4982       for (jo=0; jo<ncols_o; jo++) {
4983         col = cmap[*bj];
4984         if (col >= cstart) break;
4985         *cam++ = *ba++; bj++;
4986       }
4987       /* diagonal portion of A */
4988       ncols_d = ai[i+1] - ai[i];
4989       for (j=0; j<ncols_d; j++) *cam++ = *aa++;
4990       /* off-diagonal portion of A */
4991       for (j=jo; j<ncols_o; j++) {
4992         *cam++ = *ba++; bj++;
4993       }
4994     }
4995   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid MatReuse %d",(int)scall);
4996   ierr = PetscLogEventEnd(MAT_Getlocalmat,A,0,0,0);CHKERRQ(ierr);
4997   PetscFunctionReturn(0);
4998 }
4999 
5000 #undef __FUNCT__
5001 #define __FUNCT__ "MatMPIAIJGetLocalMatCondensed"
5002 /*@C
5003      MatMPIAIJGetLocalMatCondensed - Creates a SeqAIJ matrix from an MPIAIJ matrix by taking all its local rows and NON-ZERO columns
5004 
5005     Not Collective
5006 
5007    Input Parameters:
5008 +    A - the matrix
5009 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5010 -    row, col - index sets of rows and columns to extract (or PETSC_NULL)
5011 
5012    Output Parameter:
5013 .    A_loc - the local sequential matrix generated
5014 
5015     Level: developer
5016 
5017 .seealso: MatGetOwnershipRange(), MatMPIAIJGetLocalMat()
5018 
5019 @*/
5020 PetscErrorCode  MatMPIAIJGetLocalMatCondensed(Mat A,MatReuse scall,IS *row,IS *col,Mat *A_loc)
5021 {
5022   Mat_MPIAIJ        *a=(Mat_MPIAIJ*)A->data;
5023   PetscErrorCode    ierr;
5024   PetscInt          i,start,end,ncols,nzA,nzB,*cmap,imark,*idx;
5025   IS                isrowa,iscola;
5026   Mat               *aloc;
5027   PetscBool       match;
5028 
5029   PetscFunctionBegin;
5030   ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&match);CHKERRQ(ierr);
5031   if (!match) SETERRQ(((PetscObject)A)->comm, PETSC_ERR_SUP,"Requires MPIAIJ matrix as input");
5032   ierr = PetscLogEventBegin(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5033   if (!row){
5034     start = A->rmap->rstart; end = A->rmap->rend;
5035     ierr = ISCreateStride(PETSC_COMM_SELF,end-start,start,1,&isrowa);CHKERRQ(ierr);
5036   } else {
5037     isrowa = *row;
5038   }
5039   if (!col){
5040     start = A->cmap->rstart;
5041     cmap  = a->garray;
5042     nzA   = a->A->cmap->n;
5043     nzB   = a->B->cmap->n;
5044     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
5045     ncols = 0;
5046     for (i=0; i<nzB; i++) {
5047       if (cmap[i] < start) idx[ncols++] = cmap[i];
5048       else break;
5049     }
5050     imark = i;
5051     for (i=0; i<nzA; i++) idx[ncols++] = start + i;
5052     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i];
5053     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&iscola);CHKERRQ(ierr);
5054   } else {
5055     iscola = *col;
5056   }
5057   if (scall != MAT_INITIAL_MATRIX){
5058     ierr = PetscMalloc(sizeof(Mat),&aloc);CHKERRQ(ierr);
5059     aloc[0] = *A_loc;
5060   }
5061   ierr = MatGetSubMatrices(A,1,&isrowa,&iscola,scall,&aloc);CHKERRQ(ierr);
5062   *A_loc = aloc[0];
5063   ierr = PetscFree(aloc);CHKERRQ(ierr);
5064   if (!row){
5065     ierr = ISDestroy(&isrowa);CHKERRQ(ierr);
5066   }
5067   if (!col){
5068     ierr = ISDestroy(&iscola);CHKERRQ(ierr);
5069   }
5070   ierr = PetscLogEventEnd(MAT_Getlocalmatcondensed,A,0,0,0);CHKERRQ(ierr);
5071   PetscFunctionReturn(0);
5072 }
5073 
5074 #undef __FUNCT__
5075 #define __FUNCT__ "MatGetBrowsOfAcols"
5076 /*@C
5077     MatGetBrowsOfAcols - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns of local A
5078 
5079     Collective on Mat
5080 
5081    Input Parameters:
5082 +    A,B - the matrices in mpiaij format
5083 .    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5084 -    rowb, colb - index sets of rows and columns of B to extract (or PETSC_NULL)
5085 
5086    Output Parameter:
5087 +    rowb, colb - index sets of rows and columns of B to extract
5088 -    B_seq - the sequential matrix generated
5089 
5090     Level: developer
5091 
5092 @*/
5093 PetscErrorCode  MatGetBrowsOfAcols(Mat A,Mat B,MatReuse scall,IS *rowb,IS *colb,Mat *B_seq)
5094 {
5095   Mat_MPIAIJ        *a=(Mat_MPIAIJ*)A->data;
5096   PetscErrorCode    ierr;
5097   PetscInt          *idx,i,start,ncols,nzA,nzB,*cmap,imark;
5098   IS                isrowb,iscolb;
5099   Mat               *bseq=PETSC_NULL;
5100 
5101   PetscFunctionBegin;
5102   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
5103     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%D, %D) != (%D,%D)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
5104   }
5105   ierr = PetscLogEventBegin(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5106 
5107   if (scall == MAT_INITIAL_MATRIX){
5108     start = A->cmap->rstart;
5109     cmap  = a->garray;
5110     nzA   = a->A->cmap->n;
5111     nzB   = a->B->cmap->n;
5112     ierr  = PetscMalloc((nzA+nzB)*sizeof(PetscInt), &idx);CHKERRQ(ierr);
5113     ncols = 0;
5114     for (i=0; i<nzB; i++) {  /* row < local row index */
5115       if (cmap[i] < start) idx[ncols++] = cmap[i];
5116       else break;
5117     }
5118     imark = i;
5119     for (i=0; i<nzA; i++) idx[ncols++] = start + i;  /* local rows */
5120     for (i=imark; i<nzB; i++) idx[ncols++] = cmap[i]; /* row > local row index */
5121     ierr = ISCreateGeneral(PETSC_COMM_SELF,ncols,idx,PETSC_OWN_POINTER,&isrowb);CHKERRQ(ierr);
5122     ierr = ISCreateStride(PETSC_COMM_SELF,B->cmap->N,0,1,&iscolb);CHKERRQ(ierr);
5123   } else {
5124     if (!rowb || !colb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"IS rowb and colb must be provided for MAT_REUSE_MATRIX");
5125     isrowb = *rowb; iscolb = *colb;
5126     ierr = PetscMalloc(sizeof(Mat),&bseq);CHKERRQ(ierr);
5127     bseq[0] = *B_seq;
5128   }
5129   ierr = MatGetSubMatrices(B,1,&isrowb,&iscolb,scall,&bseq);CHKERRQ(ierr);
5130   *B_seq = bseq[0];
5131   ierr = PetscFree(bseq);CHKERRQ(ierr);
5132   if (!rowb){
5133     ierr = ISDestroy(&isrowb);CHKERRQ(ierr);
5134   } else {
5135     *rowb = isrowb;
5136   }
5137   if (!colb){
5138     ierr = ISDestroy(&iscolb);CHKERRQ(ierr);
5139   } else {
5140     *colb = iscolb;
5141   }
5142   ierr = PetscLogEventEnd(MAT_GetBrowsOfAcols,A,B,0,0);CHKERRQ(ierr);
5143   PetscFunctionReturn(0);
5144 }
5145 
5146 #undef __FUNCT__
5147 #define __FUNCT__ "MatGetBrowsOfAoCols_MPIAIJ"
5148 /*
5149     MatGetBrowsOfAoCols_MPIAIJ - Creates a SeqAIJ matrix by taking rows of B that equal to nonzero columns
5150     of the OFF-DIAGONAL portion of local A
5151 
5152     Collective on Mat
5153 
5154    Input Parameters:
5155 +    A,B - the matrices in mpiaij format
5156 -    scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
5157 
5158    Output Parameter:
5159 +    startsj_s - starting point in B's sending j-arrays, saved for MAT_REUSE (or PETSC_NULL)
5160 .    startsj_r - starting point in B's receiving j-arrays, saved for MAT_REUSE (or PETSC_NULL)
5161 .    bufa_ptr - array for sending matrix values, saved for MAT_REUSE (or PETSC_NULL)
5162 -    B_oth - the sequential matrix generated with size aBn=a->B->cmap->n by B->cmap->N
5163 
5164     Level: developer
5165 
5166 */
5167 PetscErrorCode  MatGetBrowsOfAoCols_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscInt **startsj_s,PetscInt **startsj_r,MatScalar **bufa_ptr,Mat *B_oth)
5168 {
5169   VecScatter_MPI_General *gen_to,*gen_from;
5170   PetscErrorCode         ierr;
5171   Mat_MPIAIJ             *a=(Mat_MPIAIJ*)A->data;
5172   Mat_SeqAIJ             *b_oth;
5173   VecScatter             ctx=a->Mvctx;
5174   MPI_Comm               comm=((PetscObject)ctx)->comm;
5175   PetscMPIInt            *rprocs,*sprocs,tag=((PetscObject)ctx)->tag,rank;
5176   PetscInt               *rowlen,*bufj,*bufJ,ncols,aBn=a->B->cmap->n,row,*b_othi,*b_othj;
5177   PetscScalar            *rvalues,*svalues;
5178   MatScalar              *b_otha,*bufa,*bufA;
5179   PetscInt               i,j,k,l,ll,nrecvs,nsends,nrows,*srow,*rstarts,*rstartsj = 0,*sstarts,*sstartsj,len;
5180   MPI_Request            *rwaits = PETSC_NULL,*swaits = PETSC_NULL;
5181   MPI_Status             *sstatus,rstatus;
5182   PetscMPIInt            jj;
5183   PetscInt               *cols,sbs,rbs;
5184   PetscScalar            *vals;
5185 
5186   PetscFunctionBegin;
5187   if (A->cmap->rstart != B->rmap->rstart || A->cmap->rend != B->rmap->rend){
5188     SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Matrix local dimensions are incompatible, (%d, %d) != (%d,%d)",A->cmap->rstart,A->cmap->rend,B->rmap->rstart,B->rmap->rend);
5189   }
5190   ierr = PetscLogEventBegin(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5191   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
5192 
5193   gen_to   = (VecScatter_MPI_General*)ctx->todata;
5194   gen_from = (VecScatter_MPI_General*)ctx->fromdata;
5195   rvalues  = gen_from->values; /* holds the length of receiving row */
5196   svalues  = gen_to->values;   /* holds the length of sending row */
5197   nrecvs   = gen_from->n;
5198   nsends   = gen_to->n;
5199 
5200   ierr = PetscMalloc2(nrecvs,MPI_Request,&rwaits,nsends,MPI_Request,&swaits);CHKERRQ(ierr);
5201   srow     = gen_to->indices;   /* local row index to be sent */
5202   sstarts  = gen_to->starts;
5203   sprocs   = gen_to->procs;
5204   sstatus  = gen_to->sstatus;
5205   sbs      = gen_to->bs;
5206   rstarts  = gen_from->starts;
5207   rprocs   = gen_from->procs;
5208   rbs      = gen_from->bs;
5209 
5210   if (!startsj_s || !bufa_ptr) scall = MAT_INITIAL_MATRIX;
5211   if (scall == MAT_INITIAL_MATRIX){
5212     /* i-array */
5213     /*---------*/
5214     /*  post receives */
5215     for (i=0; i<nrecvs; i++){
5216       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5217       nrows = (rstarts[i+1]-rstarts[i])*rbs; /* num of indices to be received */
5218       ierr = MPI_Irecv(rowlen,nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5219     }
5220 
5221     /* pack the outgoing message */
5222     ierr = PetscMalloc2(nsends+1,PetscInt,&sstartsj,nrecvs+1,PetscInt,&rstartsj);CHKERRQ(ierr);
5223     sstartsj[0] = 0;  rstartsj[0] = 0;
5224     len = 0; /* total length of j or a array to be sent */
5225     k = 0;
5226     for (i=0; i<nsends; i++){
5227       rowlen = (PetscInt*)svalues + sstarts[i]*sbs;
5228       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5229       for (j=0; j<nrows; j++) {
5230         row = srow[k] + B->rmap->range[rank]; /* global row idx */
5231         for (l=0; l<sbs; l++){
5232           ierr = MatGetRow_MPIAIJ(B,row+l,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); /* rowlength */
5233           rowlen[j*sbs+l] = ncols;
5234           len += ncols;
5235           ierr = MatRestoreRow_MPIAIJ(B,row+l,&ncols,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
5236         }
5237         k++;
5238       }
5239       ierr = MPI_Isend(rowlen,nrows*sbs,MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5240       sstartsj[i+1] = len;  /* starting point of (i+1)-th outgoing msg in bufj and bufa */
5241     }
5242     /* recvs and sends of i-array are completed */
5243     i = nrecvs;
5244     while (i--) {
5245       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5246     }
5247     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5248 
5249     /* allocate buffers for sending j and a arrays */
5250     ierr = PetscMalloc((len+1)*sizeof(PetscInt),&bufj);CHKERRQ(ierr);
5251     ierr = PetscMalloc((len+1)*sizeof(PetscScalar),&bufa);CHKERRQ(ierr);
5252 
5253     /* create i-array of B_oth */
5254     ierr = PetscMalloc((aBn+2)*sizeof(PetscInt),&b_othi);CHKERRQ(ierr);
5255     b_othi[0] = 0;
5256     len = 0; /* total length of j or a array to be received */
5257     k = 0;
5258     for (i=0; i<nrecvs; i++){
5259       rowlen = (PetscInt*)rvalues + rstarts[i]*rbs;
5260       nrows = rbs*(rstarts[i+1]-rstarts[i]); /* num of rows to be recieved */
5261       for (j=0; j<nrows; j++) {
5262         b_othi[k+1] = b_othi[k] + rowlen[j];
5263         len += rowlen[j]; k++;
5264       }
5265       rstartsj[i+1] = len; /* starting point of (i+1)-th incoming msg in bufj and bufa */
5266     }
5267 
5268     /* allocate space for j and a arrrays of B_oth */
5269     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(PetscInt),&b_othj);CHKERRQ(ierr);
5270     ierr = PetscMalloc((b_othi[aBn]+1)*sizeof(MatScalar),&b_otha);CHKERRQ(ierr);
5271 
5272     /* j-array */
5273     /*---------*/
5274     /*  post receives of j-array */
5275     for (i=0; i<nrecvs; i++){
5276       nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5277       ierr = MPI_Irecv(b_othj+rstartsj[i],nrows,MPIU_INT,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5278     }
5279 
5280     /* pack the outgoing message j-array */
5281     k = 0;
5282     for (i=0; i<nsends; i++){
5283       nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5284       bufJ = bufj+sstartsj[i];
5285       for (j=0; j<nrows; j++) {
5286         row  = srow[k++] + B->rmap->range[rank]; /* global row idx */
5287         for (ll=0; ll<sbs; ll++){
5288           ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,&cols,PETSC_NULL);CHKERRQ(ierr);
5289           for (l=0; l<ncols; l++){
5290             *bufJ++ = cols[l];
5291           }
5292           ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,&cols,PETSC_NULL);CHKERRQ(ierr);
5293         }
5294       }
5295       ierr = MPI_Isend(bufj+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_INT,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5296     }
5297 
5298     /* recvs and sends of j-array are completed */
5299     i = nrecvs;
5300     while (i--) {
5301       ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5302     }
5303     if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5304   } else if (scall == MAT_REUSE_MATRIX){
5305     sstartsj = *startsj_s;
5306     rstartsj = *startsj_r;
5307     bufa     = *bufa_ptr;
5308     b_oth    = (Mat_SeqAIJ*)(*B_oth)->data;
5309     b_otha   = b_oth->a;
5310   } else {
5311     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Matrix P does not posses an object container");
5312   }
5313 
5314   /* a-array */
5315   /*---------*/
5316   /*  post receives of a-array */
5317   for (i=0; i<nrecvs; i++){
5318     nrows = rstartsj[i+1]-rstartsj[i]; /* length of the msg received */
5319     ierr = MPI_Irecv(b_otha+rstartsj[i],nrows,MPIU_SCALAR,rprocs[i],tag,comm,rwaits+i);CHKERRQ(ierr);
5320   }
5321 
5322   /* pack the outgoing message a-array */
5323   k = 0;
5324   for (i=0; i<nsends; i++){
5325     nrows = sstarts[i+1]-sstarts[i]; /* num of block rows */
5326     bufA = bufa+sstartsj[i];
5327     for (j=0; j<nrows; j++) {
5328       row  = srow[k++] + B->rmap->range[rank]; /* global row idx */
5329       for (ll=0; ll<sbs; ll++){
5330         ierr = MatGetRow_MPIAIJ(B,row+ll,&ncols,PETSC_NULL,&vals);CHKERRQ(ierr);
5331         for (l=0; l<ncols; l++){
5332           *bufA++ = vals[l];
5333         }
5334         ierr = MatRestoreRow_MPIAIJ(B,row+ll,&ncols,PETSC_NULL,&vals);CHKERRQ(ierr);
5335       }
5336     }
5337     ierr = MPI_Isend(bufa+sstartsj[i],sstartsj[i+1]-sstartsj[i],MPIU_SCALAR,sprocs[i],tag,comm,swaits+i);CHKERRQ(ierr);
5338   }
5339   /* recvs and sends of a-array are completed */
5340   i = nrecvs;
5341   while (i--) {
5342     ierr = MPI_Waitany(nrecvs,rwaits,&jj,&rstatus);CHKERRQ(ierr);
5343   }
5344   if (nsends) {ierr = MPI_Waitall(nsends,swaits,sstatus);CHKERRQ(ierr);}
5345   ierr = PetscFree2(rwaits,swaits);CHKERRQ(ierr);
5346 
5347   if (scall == MAT_INITIAL_MATRIX){
5348     /* put together the new matrix */
5349     ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,aBn,B->cmap->N,b_othi,b_othj,b_otha,B_oth);CHKERRQ(ierr);
5350 
5351     /* MatCreateSeqAIJWithArrays flags matrix so PETSc doesn't free the user's arrays. */
5352     /* Since these are PETSc arrays, change flags to free them as necessary. */
5353     b_oth          = (Mat_SeqAIJ *)(*B_oth)->data;
5354     b_oth->free_a  = PETSC_TRUE;
5355     b_oth->free_ij = PETSC_TRUE;
5356     b_oth->nonew   = 0;
5357 
5358     ierr = PetscFree(bufj);CHKERRQ(ierr);
5359     if (!startsj_s || !bufa_ptr){
5360       ierr = PetscFree2(sstartsj,rstartsj);CHKERRQ(ierr);
5361       ierr = PetscFree(bufa_ptr);CHKERRQ(ierr);
5362     } else {
5363       *startsj_s = sstartsj;
5364       *startsj_r = rstartsj;
5365       *bufa_ptr  = bufa;
5366     }
5367   }
5368   ierr = PetscLogEventEnd(MAT_GetBrowsOfAocols,A,B,0,0);CHKERRQ(ierr);
5369   PetscFunctionReturn(0);
5370 }
5371 
5372 #undef __FUNCT__
5373 #define __FUNCT__ "MatGetCommunicationStructs"
5374 /*@C
5375   MatGetCommunicationStructs - Provides access to the communication structures used in matrix-vector multiplication.
5376 
5377   Not Collective
5378 
5379   Input Parameters:
5380 . A - The matrix in mpiaij format
5381 
5382   Output Parameter:
5383 + lvec - The local vector holding off-process values from the argument to a matrix-vector product
5384 . colmap - A map from global column index to local index into lvec
5385 - multScatter - A scatter from the argument of a matrix-vector product to lvec
5386 
5387   Level: developer
5388 
5389 @*/
5390 #if defined (PETSC_USE_CTABLE)
5391 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscTable *colmap, VecScatter *multScatter)
5392 #else
5393 PetscErrorCode  MatGetCommunicationStructs(Mat A, Vec *lvec, PetscInt *colmap[], VecScatter *multScatter)
5394 #endif
5395 {
5396   Mat_MPIAIJ *a;
5397 
5398   PetscFunctionBegin;
5399   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
5400   PetscValidPointer(lvec, 2);
5401   PetscValidPointer(colmap, 3);
5402   PetscValidPointer(multScatter, 4);
5403   a = (Mat_MPIAIJ *) A->data;
5404   if (lvec) *lvec = a->lvec;
5405   if (colmap) *colmap = a->colmap;
5406   if (multScatter) *multScatter = a->Mvctx;
5407   PetscFunctionReturn(0);
5408 }
5409 
5410 EXTERN_C_BEGIN
5411 extern PetscErrorCode  MatConvert_MPIAIJ_MPIAIJCRL(Mat,const MatType,MatReuse,Mat*);
5412 extern PetscErrorCode  MatConvert_MPIAIJ_MPIAIJPERM(Mat,const MatType,MatReuse,Mat*);
5413 extern PetscErrorCode  MatConvert_MPIAIJ_MPISBAIJ(Mat,const MatType,MatReuse,Mat*);
5414 EXTERN_C_END
5415 
5416 #undef __FUNCT__
5417 #define __FUNCT__ "MatMatMultNumeric_MPIDense_MPIAIJ"
5418 /*
5419     Computes (B'*A')' since computing B*A directly is untenable
5420 
5421                n                       p                          p
5422         (              )       (              )         (                  )
5423       m (      A       )  *  n (       B      )   =   m (         C        )
5424         (              )       (              )         (                  )
5425 
5426 */
5427 PetscErrorCode MatMatMultNumeric_MPIDense_MPIAIJ(Mat A,Mat B,Mat C)
5428 {
5429   PetscErrorCode     ierr;
5430   Mat                At,Bt,Ct;
5431 
5432   PetscFunctionBegin;
5433   ierr = MatTranspose(A,MAT_INITIAL_MATRIX,&At);CHKERRQ(ierr);
5434   ierr = MatTranspose(B,MAT_INITIAL_MATRIX,&Bt);CHKERRQ(ierr);
5435   ierr = MatMatMult(Bt,At,MAT_INITIAL_MATRIX,1.0,&Ct);CHKERRQ(ierr);
5436   ierr = MatDestroy(&At);CHKERRQ(ierr);
5437   ierr = MatDestroy(&Bt);CHKERRQ(ierr);
5438   ierr = MatTranspose(Ct,MAT_REUSE_MATRIX,&C);CHKERRQ(ierr);
5439   ierr = MatDestroy(&Ct);CHKERRQ(ierr);
5440   PetscFunctionReturn(0);
5441 }
5442 
5443 #undef __FUNCT__
5444 #define __FUNCT__ "MatMatMultSymbolic_MPIDense_MPIAIJ"
5445 PetscErrorCode MatMatMultSymbolic_MPIDense_MPIAIJ(Mat A,Mat B,PetscReal fill,Mat *C)
5446 {
5447   PetscErrorCode ierr;
5448   PetscInt       m=A->rmap->n,n=B->cmap->n;
5449   Mat            Cmat;
5450 
5451   PetscFunctionBegin;
5452   if (A->cmap->n != B->rmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"A->cmap->n %d != B->rmap->n %d\n",A->cmap->n,B->rmap->n);
5453   ierr = MatCreate(((PetscObject)A)->comm,&Cmat);CHKERRQ(ierr);
5454   ierr = MatSetSizes(Cmat,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
5455   ierr = MatSetBlockSizes(Cmat,A->rmap->bs,B->cmap->bs);CHKERRQ(ierr);
5456   ierr = MatSetType(Cmat,MATMPIDENSE);CHKERRQ(ierr);
5457   ierr = MatMPIDenseSetPreallocation(Cmat,PETSC_NULL);CHKERRQ(ierr);
5458   ierr = MatAssemblyBegin(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5459   ierr = MatAssemblyEnd(Cmat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5460   *C   = Cmat;
5461   (*C)->ops->matmult = MatMatMult_MPIDense_MPIAIJ;
5462   PetscFunctionReturn(0);
5463 }
5464 
5465 /* ----------------------------------------------------------------*/
5466 #undef __FUNCT__
5467 #define __FUNCT__ "MatMatMult_MPIDense_MPIAIJ"
5468 PetscErrorCode MatMatMult_MPIDense_MPIAIJ(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
5469 {
5470   PetscErrorCode ierr;
5471 
5472   PetscFunctionBegin;
5473   if (scall == MAT_INITIAL_MATRIX){
5474     ierr = MatMatMultSymbolic_MPIDense_MPIAIJ(A,B,fill,C);CHKERRQ(ierr);
5475   }
5476   ierr = MatMatMultNumeric_MPIDense_MPIAIJ(A,B,*C);CHKERRQ(ierr);
5477   PetscFunctionReturn(0);
5478 }
5479 
5480 EXTERN_C_BEGIN
5481 #if defined(PETSC_HAVE_MUMPS)
5482 extern PetscErrorCode MatGetFactor_aij_mumps(Mat,MatFactorType,Mat*);
5483 #endif
5484 #if defined(PETSC_HAVE_PASTIX)
5485 extern PetscErrorCode MatGetFactor_mpiaij_pastix(Mat,MatFactorType,Mat*);
5486 #endif
5487 #if defined(PETSC_HAVE_SUPERLU_DIST)
5488 extern PetscErrorCode MatGetFactor_mpiaij_superlu_dist(Mat,MatFactorType,Mat*);
5489 #endif
5490 #if defined(PETSC_HAVE_SPOOLES)
5491 extern PetscErrorCode MatGetFactor_mpiaij_spooles(Mat,MatFactorType,Mat*);
5492 #endif
5493 EXTERN_C_END
5494 
5495 /*MC
5496    MATMPIAIJ - MATMPIAIJ = "mpiaij" - A matrix type to be used for parallel sparse matrices.
5497 
5498    Options Database Keys:
5499 . -mat_type mpiaij - sets the matrix type to "mpiaij" during a call to MatSetFromOptions()
5500 
5501   Level: beginner
5502 
5503 .seealso: MatCreateAIJ()
5504 M*/
5505 
5506 EXTERN_C_BEGIN
5507 #undef __FUNCT__
5508 #define __FUNCT__ "MatCreate_MPIAIJ"
5509 PetscErrorCode  MatCreate_MPIAIJ(Mat B)
5510 {
5511   Mat_MPIAIJ     *b;
5512   PetscErrorCode ierr;
5513   PetscMPIInt    size;
5514 
5515   PetscFunctionBegin;
5516   ierr = MPI_Comm_size(((PetscObject)B)->comm,&size);CHKERRQ(ierr);
5517 
5518   ierr            = PetscNewLog(B,Mat_MPIAIJ,&b);CHKERRQ(ierr);
5519   B->data         = (void*)b;
5520   ierr            = PetscMemcpy(B->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
5521   B->assembled    = PETSC_FALSE;
5522 
5523   B->insertmode   = NOT_SET_VALUES;
5524   b->size         = size;
5525   ierr = MPI_Comm_rank(((PetscObject)B)->comm,&b->rank);CHKERRQ(ierr);
5526 
5527   /* build cache for off array entries formed */
5528   ierr = MatStashCreate_Private(((PetscObject)B)->comm,1,&B->stash);CHKERRQ(ierr);
5529   b->donotstash  = PETSC_FALSE;
5530   b->colmap      = 0;
5531   b->garray      = 0;
5532   b->roworiented = PETSC_TRUE;
5533 
5534   /* stuff used for matrix vector multiply */
5535   b->lvec      = PETSC_NULL;
5536   b->Mvctx     = PETSC_NULL;
5537 
5538   /* stuff for MatGetRow() */
5539   b->rowindices   = 0;
5540   b->rowvalues    = 0;
5541   b->getrowactive = PETSC_FALSE;
5542 
5543 #if defined(PETSC_HAVE_SPOOLES)
5544   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_spooles_C",
5545                                      "MatGetFactor_mpiaij_spooles",
5546                                      MatGetFactor_mpiaij_spooles);CHKERRQ(ierr);
5547 #endif
5548 #if defined(PETSC_HAVE_MUMPS)
5549   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_mumps_C",
5550                                      "MatGetFactor_aij_mumps",
5551                                      MatGetFactor_aij_mumps);CHKERRQ(ierr);
5552 #endif
5553 #if defined(PETSC_HAVE_PASTIX)
5554   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_pastix_C",
5555 					   "MatGetFactor_mpiaij_pastix",
5556 					   MatGetFactor_mpiaij_pastix);CHKERRQ(ierr);
5557 #endif
5558 #if defined(PETSC_HAVE_SUPERLU_DIST)
5559   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetFactor_superlu_dist_C",
5560                                      "MatGetFactor_mpiaij_superlu_dist",
5561                                      MatGetFactor_mpiaij_superlu_dist);CHKERRQ(ierr);
5562 #endif
5563   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatStoreValues_C",
5564                                      "MatStoreValues_MPIAIJ",
5565                                      MatStoreValues_MPIAIJ);CHKERRQ(ierr);
5566   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatRetrieveValues_C",
5567                                      "MatRetrieveValues_MPIAIJ",
5568                                      MatRetrieveValues_MPIAIJ);CHKERRQ(ierr);
5569   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatGetDiagonalBlock_C",
5570 				     "MatGetDiagonalBlock_MPIAIJ",
5571                                      MatGetDiagonalBlock_MPIAIJ);CHKERRQ(ierr);
5572   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatIsTranspose_C",
5573 				     "MatIsTranspose_MPIAIJ",
5574 				     MatIsTranspose_MPIAIJ);CHKERRQ(ierr);
5575   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMPIAIJSetPreallocation_C",
5576 				     "MatMPIAIJSetPreallocation_MPIAIJ",
5577 				     MatMPIAIJSetPreallocation_MPIAIJ);CHKERRQ(ierr);
5578   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMPIAIJSetPreallocationCSR_C",
5579 				     "MatMPIAIJSetPreallocationCSR_MPIAIJ",
5580 				     MatMPIAIJSetPreallocationCSR_MPIAIJ);CHKERRQ(ierr);
5581   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatDiagonalScaleLocal_C",
5582 				     "MatDiagonalScaleLocal_MPIAIJ",
5583 				     MatDiagonalScaleLocal_MPIAIJ);CHKERRQ(ierr);
5584   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpiaijperm_C",
5585                                      "MatConvert_MPIAIJ_MPIAIJPERM",
5586                                       MatConvert_MPIAIJ_MPIAIJPERM);CHKERRQ(ierr);
5587   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpiaijcrl_C",
5588                                      "MatConvert_MPIAIJ_MPIAIJCRL",
5589                                       MatConvert_MPIAIJ_MPIAIJCRL);CHKERRQ(ierr);
5590   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_mpiaij_mpisbaij_C",
5591                                      "MatConvert_MPIAIJ_MPISBAIJ",
5592                                       MatConvert_MPIAIJ_MPISBAIJ);CHKERRQ(ierr);
5593   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMult_mpidense_mpiaij_C",
5594                                      "MatMatMult_MPIDense_MPIAIJ",
5595                                       MatMatMult_MPIDense_MPIAIJ);CHKERRQ(ierr);
5596   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMultSymbolic_mpidense_mpiaij_C",
5597                                      "MatMatMultSymbolic_MPIDense_MPIAIJ",
5598                                      MatMatMultSymbolic_MPIDense_MPIAIJ);CHKERRQ(ierr);
5599   ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatMatMultNumeric_mpidense_mpiaij_C",
5600                                      "MatMatMultNumeric_MPIDense_MPIAIJ",
5601                                       MatMatMultNumeric_MPIDense_MPIAIJ);CHKERRQ(ierr);
5602   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPIAIJ);CHKERRQ(ierr);
5603   PetscFunctionReturn(0);
5604 }
5605 EXTERN_C_END
5606 
5607 #undef __FUNCT__
5608 #define __FUNCT__ "MatCreateMPIAIJWithSplitArrays"
5609 /*@
5610      MatCreateMPIAIJWithSplitArrays - creates a MPI AIJ matrix using arrays that contain the "diagonal"
5611          and "off-diagonal" part of the matrix in CSR format.
5612 
5613    Collective on MPI_Comm
5614 
5615    Input Parameters:
5616 +  comm - MPI communicator
5617 .  m - number of local rows (Cannot be PETSC_DECIDE)
5618 .  n - This value should be the same as the local size used in creating the
5619        x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
5620        calculated if N is given) For square matrices n is almost always m.
5621 .  M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
5622 .  N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
5623 .   i - row indices for "diagonal" portion of matrix
5624 .   j - column indices
5625 .   a - matrix values
5626 .   oi - row indices for "off-diagonal" portion of matrix
5627 .   oj - column indices
5628 -   oa - matrix values
5629 
5630    Output Parameter:
5631 .   mat - the matrix
5632 
5633    Level: advanced
5634 
5635    Notes:
5636        The i, j, and a arrays ARE NOT copied by this routine into the internal format used by PETSc. The user
5637        must free the arrays once the matrix has been destroyed and not before.
5638 
5639        The i and j indices are 0 based
5640 
5641        See MatCreateAIJ() for the definition of "diagonal" and "off-diagonal" portion of the matrix
5642 
5643        This sets local rows and cannot be used to set off-processor values.
5644 
5645        You cannot later use MatSetValues() to change values in this matrix.
5646 
5647 .keywords: matrix, aij, compressed row, sparse, parallel
5648 
5649 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues(), MatMPIAIJSetPreallocation(), MatMPIAIJSetPreallocationCSR(),
5650           MPIAIJ, MatCreateAIJ(), MatCreateMPIAIJWithArrays()
5651 @*/
5652 PetscErrorCode  MatCreateMPIAIJWithSplitArrays(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt i[],PetscInt j[],PetscScalar a[],
5653 								PetscInt oi[], PetscInt oj[],PetscScalar oa[],Mat *mat)
5654 {
5655   PetscErrorCode ierr;
5656   Mat_MPIAIJ     *maij;
5657 
5658  PetscFunctionBegin;
5659   if (m < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"local number of rows (m) cannot be PETSC_DECIDE, or negative");
5660   if (i[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"i (row indices) must start with 0");
5661   if (oi[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"oi (row indices) must start with 0");
5662   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
5663   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
5664   ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
5665   maij = (Mat_MPIAIJ*) (*mat)->data;
5666   maij->donotstash     = PETSC_TRUE;
5667   (*mat)->preallocated = PETSC_TRUE;
5668 
5669   ierr = PetscLayoutSetUp((*mat)->rmap);CHKERRQ(ierr);
5670   ierr = PetscLayoutSetUp((*mat)->cmap);CHKERRQ(ierr);
5671 
5672   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,n,i,j,a,&maij->A);CHKERRQ(ierr);
5673   ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,m,(*mat)->cmap->N,oi,oj,oa,&maij->B);CHKERRQ(ierr);
5674 
5675   ierr = MatAssemblyBegin(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5676   ierr = MatAssemblyEnd(maij->A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5677   ierr = MatAssemblyBegin(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5678   ierr = MatAssemblyEnd(maij->B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5679 
5680   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5681   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
5682   PetscFunctionReturn(0);
5683 }
5684 
5685 /*
5686     Special version for direct calls from Fortran
5687 */
5688 #include <petsc-private/fortranimpl.h>
5689 
5690 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5691 #define matsetvaluesmpiaij_ MATSETVALUESMPIAIJ
5692 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5693 #define matsetvaluesmpiaij_ matsetvaluesmpiaij
5694 #endif
5695 
5696 /* Change these macros so can be used in void function */
5697 #undef CHKERRQ
5698 #define CHKERRQ(ierr) CHKERRABORT(PETSC_COMM_WORLD,ierr)
5699 #undef SETERRQ2
5700 #define SETERRQ2(comm,ierr,b,c,d) CHKERRABORT(comm,ierr)
5701 #undef SETERRQ3
5702 #define SETERRQ3(comm,ierr,b,c,d,e) CHKERRABORT(comm,ierr)
5703 #undef SETERRQ
5704 #define SETERRQ(c,ierr,b) CHKERRABORT(c,ierr)
5705 
5706 EXTERN_C_BEGIN
5707 #undef __FUNCT__
5708 #define __FUNCT__ "matsetvaluesmpiaij_"
5709 void PETSC_STDCALL matsetvaluesmpiaij_(Mat *mmat,PetscInt *mm,const PetscInt im[],PetscInt *mn,const PetscInt in[],const PetscScalar v[],InsertMode *maddv,PetscErrorCode *_ierr)
5710 {
5711   Mat             mat = *mmat;
5712   PetscInt        m = *mm, n = *mn;
5713   InsertMode      addv = *maddv;
5714   Mat_MPIAIJ      *aij = (Mat_MPIAIJ*)mat->data;
5715   PetscScalar     value;
5716   PetscErrorCode  ierr;
5717 
5718   MatCheckPreallocated(mat,1);
5719   if (mat->insertmode == NOT_SET_VALUES) {
5720     mat->insertmode = addv;
5721   }
5722 #if defined(PETSC_USE_DEBUG)
5723   else if (mat->insertmode != addv) {
5724     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot mix add values and insert values");
5725   }
5726 #endif
5727   {
5728   PetscInt        i,j,rstart = mat->rmap->rstart,rend = mat->rmap->rend;
5729   PetscInt        cstart = mat->cmap->rstart,cend = mat->cmap->rend,row,col;
5730   PetscBool       roworiented = aij->roworiented;
5731 
5732   /* Some Variables required in the macro */
5733   Mat             A = aij->A;
5734   Mat_SeqAIJ      *a = (Mat_SeqAIJ*)A->data;
5735   PetscInt        *aimax = a->imax,*ai = a->i,*ailen = a->ilen,*aj = a->j;
5736   MatScalar       *aa = a->a;
5737   PetscBool       ignorezeroentries = (((a->ignorezeroentries)&&(addv==ADD_VALUES))?PETSC_TRUE:PETSC_FALSE);
5738   Mat             B = aij->B;
5739   Mat_SeqAIJ      *b = (Mat_SeqAIJ*)B->data;
5740   PetscInt        *bimax = b->imax,*bi = b->i,*bilen = b->ilen,*bj = b->j,bm = aij->B->rmap->n,am = aij->A->rmap->n;
5741   MatScalar       *ba = b->a;
5742 
5743   PetscInt        *rp1,*rp2,ii,nrow1,nrow2,_i,rmax1,rmax2,N,low1,high1,low2,high2,t,lastcol1,lastcol2;
5744   PetscInt        nonew = a->nonew;
5745   MatScalar       *ap1,*ap2;
5746 
5747   PetscFunctionBegin;
5748   for (i=0; i<m; i++) {
5749     if (im[i] < 0) continue;
5750 #if defined(PETSC_USE_DEBUG)
5751     if (im[i] >= mat->rmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Row too large: row %D max %D",im[i],mat->rmap->N-1);
5752 #endif
5753     if (im[i] >= rstart && im[i] < rend) {
5754       row      = im[i] - rstart;
5755       lastcol1 = -1;
5756       rp1      = aj + ai[row];
5757       ap1      = aa + ai[row];
5758       rmax1    = aimax[row];
5759       nrow1    = ailen[row];
5760       low1     = 0;
5761       high1    = nrow1;
5762       lastcol2 = -1;
5763       rp2      = bj + bi[row];
5764       ap2      = ba + bi[row];
5765       rmax2    = bimax[row];
5766       nrow2    = bilen[row];
5767       low2     = 0;
5768       high2    = nrow2;
5769 
5770       for (j=0; j<n; j++) {
5771         if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
5772         if (ignorezeroentries && value == 0.0 && (addv == ADD_VALUES)) continue;
5773         if (in[j] >= cstart && in[j] < cend){
5774           col = in[j] - cstart;
5775           MatSetValues_SeqAIJ_A_Private(row,col,value,addv);
5776         } else if (in[j] < 0) continue;
5777 #if defined(PETSC_USE_DEBUG)
5778         else if (in[j] >= mat->cmap->N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Column too large: col %D max %D",in[j],mat->cmap->N-1);
5779 #endif
5780         else {
5781           if (mat->was_assembled) {
5782             if (!aij->colmap) {
5783               ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
5784             }
5785 #if defined (PETSC_USE_CTABLE)
5786             ierr = PetscTableFind(aij->colmap,in[j]+1,&col);CHKERRQ(ierr);
5787 	    col--;
5788 #else
5789             col = aij->colmap[in[j]] - 1;
5790 #endif
5791             if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
5792               ierr = MatDisAssemble_MPIAIJ(mat);CHKERRQ(ierr);
5793               col =  in[j];
5794               /* Reinitialize the variables required by MatSetValues_SeqAIJ_B_Private() */
5795               B = aij->B;
5796               b = (Mat_SeqAIJ*)B->data;
5797               bimax = b->imax; bi = b->i; bilen = b->ilen; bj = b->j;
5798               rp2      = bj + bi[row];
5799               ap2      = ba + bi[row];
5800               rmax2    = bimax[row];
5801               nrow2    = bilen[row];
5802               low2     = 0;
5803               high2    = nrow2;
5804               bm       = aij->B->rmap->n;
5805               ba = b->a;
5806             }
5807           } else col = in[j];
5808           MatSetValues_SeqAIJ_B_Private(row,col,value,addv);
5809         }
5810       }
5811     } else {
5812       if (!aij->donotstash) {
5813         if (roworiented) {
5814           ierr = MatStashValuesRow_Private(&mat->stash,im[i],n,in,v+i*n,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5815         } else {
5816           ierr = MatStashValuesCol_Private(&mat->stash,im[i],n,in,v+i,m,(PetscBool)(ignorezeroentries && (addv == ADD_VALUES)));CHKERRQ(ierr);
5817         }
5818       }
5819     }
5820   }}
5821   PetscFunctionReturnVoid();
5822 }
5823 EXTERN_C_END
5824 
5825