xref: /petsc/src/mat/impls/aij/mpi/mpiaij.c (revision 6d84be18fbb99ba69be7b8bdde5411a66955b7ea)
1 #ifndef lint
2 static char vcid[] = "$Id: mpiaij.c,v 1.129 1996/02/28 00:12:20 bsmith Exp bsmith $";
3 #endif
4 
5 #include "mpiaij.h"
6 #include "vec/vecimpl.h"
7 #include "inline/spops.h"
8 
9 /* local utility routine that creates a mapping from the global column
10 number to the local number in the off-diagonal part of the local
11 storage of the matrix.  This is done in a non scable way since the
12 length of colmap equals the global matrix length.
13 */
14 static int CreateColmap_Private(Mat mat)
15 {
16   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
17   Mat_SeqAIJ *B = (Mat_SeqAIJ*) aij->B->data;
18   int        n = B->n,i,shift = B->indexshift;
19 
20   aij->colmap = (int *) PetscMalloc(aij->N*sizeof(int));CHKPTRQ(aij->colmap);
21   PLogObjectMemory(mat,aij->N*sizeof(int));
22   PetscMemzero(aij->colmap,aij->N*sizeof(int));
23   for ( i=0; i<n; i++ ) aij->colmap[aij->garray[i]] = i-shift;
24   return 0;
25 }
26 
27 extern int DisAssemble_MPIAIJ(Mat);
28 
29 static int MatGetReordering_MPIAIJ(Mat mat,MatOrdering type,IS *rperm,IS *cperm)
30 {
31   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
32   int        ierr;
33   if (aij->size == 1) {
34     ierr = MatGetReordering(aij->A,type,rperm,cperm); CHKERRQ(ierr);
35   } else SETERRQ(1,"MatGetReordering_MPIAIJ:not supported in parallel");
36   return 0;
37 }
38 
39 static int MatSetValues_MPIAIJ(Mat mat,int m,int *im,int n,int *in,Scalar *v,InsertMode addv)
40 {
41   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
42   Mat_SeqAIJ *C = (Mat_SeqAIJ*) aij->A->data;
43   Scalar     value;
44   int        ierr,i,j, rstart = aij->rstart, rend = aij->rend;
45   int        cstart = aij->cstart, cend = aij->cend,row,col;
46   int        shift = C->indexshift,roworiented = aij->roworiented;
47 
48   if (aij->insertmode != NOT_SET_VALUES && aij->insertmode != addv) {
49     SETERRQ(1,"MatSetValues_MPIAIJ:Cannot mix inserts and adds");
50   }
51   aij->insertmode = addv;
52   for ( i=0; i<m; i++ ) {
53     if (im[i] < 0) SETERRQ(1,"MatSetValues_MPIAIJ:Negative row");
54     if (im[i] >= aij->M) SETERRQ(1,"MatSetValues_MPIAIJ:Row too large");
55     if (im[i] >= rstart && im[i] < rend) {
56       row = im[i] - rstart;
57       for ( j=0; j<n; j++ ) {
58         if (in[j] < 0) SETERRQ(1,"MatSetValues_MPIAIJ:Negative column");
59         if (in[j] >= aij->N) SETERRQ(1,"MatSetValues_MPIAIJ:Col too large");
60         if (in[j] >= cstart && in[j] < cend){
61           col = in[j] - cstart;
62           if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
63           ierr = MatSetValues(aij->A,1,&row,1,&col,&value,addv);CHKERRQ(ierr);
64         }
65         else {
66           if (mat->was_assembled) {
67             if (!aij->colmap) {ierr = CreateColmap_Private(mat);CHKERRQ(ierr);}
68             col = aij->colmap[in[j]] + shift;
69             if (col < 0 && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
70               ierr = DisAssemble_MPIAIJ(mat); CHKERRQ(ierr);
71               col =  in[j];
72             }
73           }
74           else col = in[j];
75           if (roworiented) value = v[i*n+j]; else value = v[i+j*m];
76           ierr = MatSetValues(aij->B,1,&row,1,&col,&value,addv);CHKERRQ(ierr);
77         }
78       }
79     }
80     else {
81       if (roworiented) {
82         ierr = StashValues_Private(&aij->stash,im[i],n,in,v+i*n,addv);CHKERRQ(ierr);
83       }
84       else {
85         row = im[i];
86         for ( j=0; j<n; j++ ) {
87           ierr = StashValues_Private(&aij->stash,row,1,in+j,v+i+j*m,addv);CHKERRQ(ierr);
88         }
89       }
90     }
91   }
92   return 0;
93 }
94 
95 static int MatGetValues_MPIAIJ(Mat mat,int m,int *idxm,int n,int *idxn,Scalar *v)
96 {
97   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
98   Mat_SeqAIJ *C = (Mat_SeqAIJ*) aij->A->data;
99   int        ierr,i,j, rstart = aij->rstart, rend = aij->rend;
100   int        cstart = aij->cstart, cend = aij->cend,row,col;
101   int        shift = C->indexshift;
102 
103   for ( i=0; i<m; i++ ) {
104     if (idxm[i] < 0) SETERRQ(1,"MatGetValues_MPIAIJ:Negative row");
105     if (idxm[i] >= aij->M) SETERRQ(1,"MatGetValues_MPIAIJ:Row too large");
106     if (idxm[i] >= rstart && idxm[i] < rend) {
107       row = idxm[i] - rstart;
108       for ( j=0; j<n; j++ ) {
109         if (idxn[j] < 0) SETERRQ(1,"MatGetValues_MPIAIJ:Negative column");
110         if (idxn[j] >= aij->N) SETERRQ(1,"MatGetValues_MPIAIJ:Col too large");
111         if (idxn[j] >= cstart && idxn[j] < cend){
112           col = idxn[j] - cstart;
113           ierr = MatGetValues(aij->A,1,&row,1,&col,v+i*n+j); CHKERRQ(ierr);
114         }
115         else {
116           col = aij->colmap[idxn[j]] + shift;
117           ierr = MatGetValues(aij->B,1,&row,1,&col,v+i*n+j); CHKERRQ(ierr);
118         }
119       }
120     }
121     else {
122       SETERRQ(1,"MatGetValues_MPIAIJ:Only local values currently supported");
123     }
124   }
125   return 0;
126 }
127 
128 static int MatAssemblyBegin_MPIAIJ(Mat mat,MatAssemblyType mode)
129 {
130   Mat_MPIAIJ  *aij = (Mat_MPIAIJ *) mat->data;
131   MPI_Comm    comm = mat->comm;
132   int         size = aij->size, *owners = aij->rowners;
133   int         rank = aij->rank,tag = mat->tag, *owner,*starts,count,ierr;
134   MPI_Request *send_waits,*recv_waits;
135   int         *nprocs,i,j,idx,*procs,nsends,nreceives,nmax,*work;
136   InsertMode  addv;
137   Scalar      *rvalues,*svalues;
138 
139   /* make sure all processors are either in INSERTMODE or ADDMODE */
140   MPI_Allreduce(&aij->insertmode,&addv,1,MPI_INT,MPI_BOR,comm);
141   if (addv == (ADD_VALUES|INSERT_VALUES)) {
142     SETERRQ(1,"MatAssemblyBegin_MPIAIJ:Some processors inserted others added");
143   }
144   aij->insertmode = addv; /* in case this processor had no cache */
145 
146   /*  first count number of contributors to each processor */
147   nprocs = (int *) PetscMalloc( 2*size*sizeof(int) ); CHKPTRQ(nprocs);
148   PetscMemzero(nprocs,2*size*sizeof(int)); procs = nprocs + size;
149   owner = (int *) PetscMalloc( (aij->stash.n+1)*sizeof(int) ); CHKPTRQ(owner);
150   for ( i=0; i<aij->stash.n; i++ ) {
151     idx = aij->stash.idx[i];
152     for ( j=0; j<size; j++ ) {
153       if (idx >= owners[j] && idx < owners[j+1]) {
154         nprocs[j]++; procs[j] = 1; owner[i] = j; break;
155       }
156     }
157   }
158   nsends = 0;  for ( i=0; i<size; i++ ) { nsends += procs[i];}
159 
160   /* inform other processors of number of messages and max length*/
161   work = (int *) PetscMalloc( size*sizeof(int) ); CHKPTRQ(work);
162   MPI_Allreduce(procs, work,size,MPI_INT,MPI_SUM,comm);
163   nreceives = work[rank];
164   MPI_Allreduce( nprocs, work,size,MPI_INT,MPI_MAX,comm);
165   nmax = work[rank];
166   PetscFree(work);
167 
168   /* post receives:
169        1) each message will consist of ordered pairs
170      (global index,value) we store the global index as a double
171      to simplify the message passing.
172        2) since we don't know how long each individual message is we
173      allocate the largest needed buffer for each receive. Potentially
174      this is a lot of wasted space.
175 
176 
177        This could be done better.
178   */
179   rvalues = (Scalar *) PetscMalloc(3*(nreceives+1)*(nmax+1)*sizeof(Scalar));
180   CHKPTRQ(rvalues);
181   recv_waits = (MPI_Request *) PetscMalloc((nreceives+1)*sizeof(MPI_Request));
182   CHKPTRQ(recv_waits);
183   for ( i=0; i<nreceives; i++ ) {
184     MPI_Irecv(rvalues+3*nmax*i,3*nmax,MPIU_SCALAR,MPI_ANY_SOURCE,tag,
185               comm,recv_waits+i);
186   }
187 
188   /* do sends:
189       1) starts[i] gives the starting index in svalues for stuff going to
190          the ith processor
191   */
192   svalues = (Scalar *) PetscMalloc(3*(aij->stash.n+1)*sizeof(Scalar));CHKPTRQ(svalues);
193   send_waits = (MPI_Request *) PetscMalloc( (nsends+1)*sizeof(MPI_Request));
194   CHKPTRQ(send_waits);
195   starts = (int *) PetscMalloc( size*sizeof(int) ); CHKPTRQ(starts);
196   starts[0] = 0;
197   for ( i=1; i<size; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
198   for ( i=0; i<aij->stash.n; i++ ) {
199     svalues[3*starts[owner[i]]]       = (Scalar)  aij->stash.idx[i];
200     svalues[3*starts[owner[i]]+1]     = (Scalar)  aij->stash.idy[i];
201     svalues[3*(starts[owner[i]]++)+2] =  aij->stash.array[i];
202   }
203   PetscFree(owner);
204   starts[0] = 0;
205   for ( i=1; i<size; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
206   count = 0;
207   for ( i=0; i<size; i++ ) {
208     if (procs[i]) {
209       MPI_Isend(svalues+3*starts[i],3*nprocs[i],MPIU_SCALAR,i,tag,
210                 comm,send_waits+count++);
211     }
212   }
213   PetscFree(starts); PetscFree(nprocs);
214 
215   /* Free cache space */
216   PLogInfo(0,"[%d]MatAssemblyBegin_MPIAIJ:Number of off processor values %d\n",rank,aij->stash.n);
217   ierr = StashDestroy_Private(&aij->stash); CHKERRQ(ierr);
218 
219   aij->svalues    = svalues;    aij->rvalues    = rvalues;
220   aij->nsends     = nsends;     aij->nrecvs     = nreceives;
221   aij->send_waits = send_waits; aij->recv_waits = recv_waits;
222   aij->rmax       = nmax;
223 
224   return 0;
225 }
226 extern int MatSetUpMultiply_MPIAIJ(Mat);
227 
228 static int MatAssemblyEnd_MPIAIJ(Mat mat,MatAssemblyType mode)
229 {
230   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
231   Mat_SeqAIJ *C = (Mat_SeqAIJ *) aij->A->data;
232   MPI_Status  *send_status,recv_status;
233   int         imdex,nrecvs = aij->nrecvs, count = nrecvs, i, n, ierr;
234   int         row,col,other_disassembled,shift = C->indexshift;
235   Scalar      *values,val;
236   InsertMode  addv = aij->insertmode;
237 
238   /*  wait on receives */
239   while (count) {
240     MPI_Waitany(nrecvs,aij->recv_waits,&imdex,&recv_status);
241     /* unpack receives into our local space */
242     values = aij->rvalues + 3*imdex*aij->rmax;
243     MPI_Get_count(&recv_status,MPIU_SCALAR,&n);
244     n = n/3;
245     for ( i=0; i<n; i++ ) {
246       row = (int) PetscReal(values[3*i]) - aij->rstart;
247       col = (int) PetscReal(values[3*i+1]);
248       val = values[3*i+2];
249       if (col >= aij->cstart && col < aij->cend) {
250         col -= aij->cstart;
251         MatSetValues(aij->A,1,&row,1,&col,&val,addv);
252       }
253       else {
254         if (mat->was_assembled) {
255           if (!aij->colmap) {ierr = CreateColmap_Private(mat);CHKERRQ(ierr);}
256           col = aij->colmap[col] + shift;
257           if (col < 0  && !((Mat_SeqAIJ*)(aij->A->data))->nonew) {
258             ierr = DisAssemble_MPIAIJ(mat); CHKERRQ(ierr);
259             col = (int) PetscReal(values[3*i+1]);
260           }
261         }
262         MatSetValues(aij->B,1,&row,1,&col,&val,addv);
263       }
264     }
265     count--;
266   }
267   PetscFree(aij->recv_waits); PetscFree(aij->rvalues);
268 
269   /* wait on sends */
270   if (aij->nsends) {
271     send_status = (MPI_Status *) PetscMalloc(aij->nsends*sizeof(MPI_Status));
272     CHKPTRQ(send_status);
273     MPI_Waitall(aij->nsends,aij->send_waits,send_status);
274     PetscFree(send_status);
275   }
276   PetscFree(aij->send_waits); PetscFree(aij->svalues);
277 
278   aij->insertmode = NOT_SET_VALUES;
279   ierr = MatAssemblyBegin(aij->A,mode); CHKERRQ(ierr);
280   ierr = MatAssemblyEnd(aij->A,mode); CHKERRQ(ierr);
281 
282   /* determine if any processor has disassembled, if so we must
283      also disassemble ourselfs, in order that we may reassemble. */
284   MPI_Allreduce(&mat->was_assembled,&other_disassembled,1,MPI_INT,MPI_PROD,mat->comm);
285   if (mat->was_assembled && !other_disassembled) {
286     ierr = DisAssemble_MPIAIJ(mat); CHKERRQ(ierr);
287   }
288 
289   if (!mat->was_assembled && mode == FINAL_ASSEMBLY) {
290     ierr = MatSetUpMultiply_MPIAIJ(mat); CHKERRQ(ierr);
291   }
292   ierr = MatAssemblyBegin(aij->B,mode); CHKERRQ(ierr);
293   ierr = MatAssemblyEnd(aij->B,mode); CHKERRQ(ierr);
294 
295   if (aij->rowvalues) {PetscFree(aij->rowvalues); aij->rowvalues = 0;}
296   return 0;
297 }
298 
299 static int MatZeroEntries_MPIAIJ(Mat A)
300 {
301   Mat_MPIAIJ *l = (Mat_MPIAIJ *) A->data;
302   int        ierr;
303   ierr = MatZeroEntries(l->A); CHKERRQ(ierr);
304   ierr = MatZeroEntries(l->B); CHKERRQ(ierr);
305   return 0;
306 }
307 
308 /* the code does not do the diagonal entries correctly unless the
309    matrix is square and the column and row owerships are identical.
310    This is a BUG. The only way to fix it seems to be to access
311    aij->A and aij->B directly and not through the MatZeroRows()
312    routine.
313 */
314 static int MatZeroRows_MPIAIJ(Mat A,IS is,Scalar *diag)
315 {
316   Mat_MPIAIJ     *l = (Mat_MPIAIJ *) A->data;
317   int            i,ierr,N, *rows,*owners = l->rowners,size = l->size;
318   int            *procs,*nprocs,j,found,idx,nsends,*work;
319   int            nmax,*svalues,*starts,*owner,nrecvs,rank = l->rank;
320   int            *rvalues,tag = A->tag,count,base,slen,n,*source;
321   int            *lens,imdex,*lrows,*values;
322   MPI_Comm       comm = A->comm;
323   MPI_Request    *send_waits,*recv_waits;
324   MPI_Status     recv_status,*send_status;
325   IS             istmp;
326 
327   ierr = ISGetLocalSize(is,&N); CHKERRQ(ierr);
328   ierr = ISGetIndices(is,&rows); CHKERRQ(ierr);
329 
330   /*  first count number of contributors to each processor */
331   nprocs = (int *) PetscMalloc( 2*size*sizeof(int) ); CHKPTRQ(nprocs);
332   PetscMemzero(nprocs,2*size*sizeof(int)); procs = nprocs + size;
333   owner = (int *) PetscMalloc((N+1)*sizeof(int)); CHKPTRQ(owner); /* see note*/
334   for ( i=0; i<N; i++ ) {
335     idx = rows[i];
336     found = 0;
337     for ( j=0; j<size; j++ ) {
338       if (idx >= owners[j] && idx < owners[j+1]) {
339         nprocs[j]++; procs[j] = 1; owner[i] = j; found = 1; break;
340       }
341     }
342     if (!found) SETERRQ(1,"MatZeroRows_MPIAIJ:Index out of range");
343   }
344   nsends = 0;  for ( i=0; i<size; i++ ) { nsends += procs[i];}
345 
346   /* inform other processors of number of messages and max length*/
347   work = (int *) PetscMalloc( size*sizeof(int) ); CHKPTRQ(work);
348   MPI_Allreduce( procs, work,size,MPI_INT,MPI_SUM,comm);
349   nrecvs = work[rank];
350   MPI_Allreduce( nprocs, work,size,MPI_INT,MPI_MAX,comm);
351   nmax = work[rank];
352   PetscFree(work);
353 
354   /* post receives:   */
355   rvalues = (int *) PetscMalloc((nrecvs+1)*(nmax+1)*sizeof(int)); /*see note */
356   CHKPTRQ(rvalues);
357   recv_waits = (MPI_Request *) PetscMalloc((nrecvs+1)*sizeof(MPI_Request));
358   CHKPTRQ(recv_waits);
359   for ( i=0; i<nrecvs; i++ ) {
360     MPI_Irecv(rvalues+nmax*i,nmax,MPI_INT,MPI_ANY_SOURCE,tag,comm,recv_waits+i);
361   }
362 
363   /* do sends:
364       1) starts[i] gives the starting index in svalues for stuff going to
365          the ith processor
366   */
367   svalues = (int *) PetscMalloc( (N+1)*sizeof(int) ); CHKPTRQ(svalues);
368   send_waits = (MPI_Request *) PetscMalloc( (nsends+1)*sizeof(MPI_Request));
369   CHKPTRQ(send_waits);
370   starts = (int *) PetscMalloc( (size+1)*sizeof(int) ); CHKPTRQ(starts);
371   starts[0] = 0;
372   for ( i=1; i<size; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
373   for ( i=0; i<N; i++ ) {
374     svalues[starts[owner[i]]++] = rows[i];
375   }
376   ISRestoreIndices(is,&rows);
377 
378   starts[0] = 0;
379   for ( i=1; i<size+1; i++ ) { starts[i] = starts[i-1] + nprocs[i-1];}
380   count = 0;
381   for ( i=0; i<size; i++ ) {
382     if (procs[i]) {
383       MPI_Isend(svalues+starts[i],nprocs[i],MPI_INT,i,tag,comm,send_waits+count++);
384     }
385   }
386   PetscFree(starts);
387 
388   base = owners[rank];
389 
390   /*  wait on receives */
391   lens   = (int *) PetscMalloc( 2*(nrecvs+1)*sizeof(int) ); CHKPTRQ(lens);
392   source = lens + nrecvs;
393   count  = nrecvs; slen = 0;
394   while (count) {
395     MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);
396     /* unpack receives into our local space */
397     MPI_Get_count(&recv_status,MPI_INT,&n);
398     source[imdex]  = recv_status.MPI_SOURCE;
399     lens[imdex]  = n;
400     slen += n;
401     count--;
402   }
403   PetscFree(recv_waits);
404 
405   /* move the data into the send scatter */
406   lrows = (int *) PetscMalloc( (slen+1)*sizeof(int) ); CHKPTRQ(lrows);
407   count = 0;
408   for ( i=0; i<nrecvs; i++ ) {
409     values = rvalues + i*nmax;
410     for ( j=0; j<lens[i]; j++ ) {
411       lrows[count++] = values[j] - base;
412     }
413   }
414   PetscFree(rvalues); PetscFree(lens);
415   PetscFree(owner); PetscFree(nprocs);
416 
417   /* actually zap the local rows */
418   ierr = ISCreateSeq(MPI_COMM_SELF,slen,lrows,&istmp);CHKERRQ(ierr);
419   PLogObjectParent(A,istmp);
420   PetscFree(lrows);
421   ierr = MatZeroRows(l->A,istmp,diag); CHKERRQ(ierr);
422   ierr = MatZeroRows(l->B,istmp,0); CHKERRQ(ierr);
423   ierr = ISDestroy(istmp); CHKERRQ(ierr);
424 
425   /* wait on sends */
426   if (nsends) {
427     send_status = (MPI_Status *) PetscMalloc(nsends*sizeof(MPI_Status));
428     CHKPTRQ(send_status);
429     MPI_Waitall(nsends,send_waits,send_status);
430     PetscFree(send_status);
431   }
432   PetscFree(send_waits); PetscFree(svalues);
433 
434   return 0;
435 }
436 
437 static int MatMult_MPIAIJ(Mat A,Vec xx,Vec yy)
438 {
439   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
440   int        ierr;
441 
442   ierr = VecScatterBegin(xx,a->lvec,INSERT_VALUES,SCATTER_ALL,a->Mvctx);CHKERRQ(ierr);
443   ierr = MatMult(a->A,xx,yy); CHKERRQ(ierr);
444   ierr = VecScatterEnd(xx,a->lvec,INSERT_VALUES,SCATTER_ALL,a->Mvctx);CHKERRQ(ierr);
445   ierr = MatMultAdd(a->B,a->lvec,yy,yy); CHKERRQ(ierr);
446   return 0;
447 }
448 
449 static int MatMultAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
450 {
451   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
452   int        ierr;
453   ierr = VecScatterBegin(xx,a->lvec,INSERT_VALUES,SCATTER_ALL,a->Mvctx);CHKERRQ(ierr);
454   ierr = MatMultAdd(a->A,xx,yy,zz); CHKERRQ(ierr);
455   ierr = VecScatterEnd(xx,a->lvec,INSERT_VALUES,SCATTER_ALL,a->Mvctx);CHKERRQ(ierr);
456   ierr = MatMultAdd(a->B,a->lvec,zz,zz); CHKERRQ(ierr);
457   return 0;
458 }
459 
460 static int MatMultTrans_MPIAIJ(Mat A,Vec xx,Vec yy)
461 {
462   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
463   int        ierr;
464 
465   /* do nondiagonal part */
466   ierr = MatMultTrans(a->B,xx,a->lvec); CHKERRQ(ierr);
467   /* send it on its way */
468   ierr = VecScatterBegin(a->lvec,yy,ADD_VALUES,
469                 (ScatterMode)(SCATTER_ALL|SCATTER_REVERSE),a->Mvctx); CHKERRQ(ierr);
470   /* do local part */
471   ierr = MatMultTrans(a->A,xx,yy); CHKERRQ(ierr);
472   /* receive remote parts: note this assumes the values are not actually */
473   /* inserted in yy until the next line, which is true for my implementation*/
474   /* but is not perhaps always true. */
475   ierr = VecScatterEnd(a->lvec,yy,ADD_VALUES,
476                   (ScatterMode)(SCATTER_ALL|SCATTER_REVERSE),a->Mvctx); CHKERRQ(ierr);
477   return 0;
478 }
479 
480 static int MatMultTransAdd_MPIAIJ(Mat A,Vec xx,Vec yy,Vec zz)
481 {
482   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
483   int        ierr;
484 
485   /* do nondiagonal part */
486   ierr = MatMultTrans(a->B,xx,a->lvec); CHKERRQ(ierr);
487   /* send it on its way */
488   ierr = VecScatterBegin(a->lvec,zz,ADD_VALUES,
489                  (ScatterMode)(SCATTER_ALL|SCATTER_REVERSE),a->Mvctx); CHKERRQ(ierr);
490   /* do local part */
491   ierr = MatMultTransAdd(a->A,xx,yy,zz); CHKERRQ(ierr);
492   /* receive remote parts: note this assumes the values are not actually */
493   /* inserted in yy until the next line, which is true for my implementation*/
494   /* but is not perhaps always true. */
495   ierr = VecScatterEnd(a->lvec,zz,ADD_VALUES,
496                   (ScatterMode)(SCATTER_ALL|SCATTER_REVERSE),a->Mvctx); CHKERRQ(ierr);
497   return 0;
498 }
499 
500 /*
501   This only works correctly for square matrices where the subblock A->A is the
502    diagonal block
503 */
504 static int MatGetDiagonal_MPIAIJ(Mat A,Vec v)
505 {
506   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
507   return MatGetDiagonal(a->A,v);
508 }
509 
510 static int MatScale_MPIAIJ(Scalar *aa,Mat A)
511 {
512   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
513   int        ierr;
514   ierr = MatScale(aa,a->A); CHKERRQ(ierr);
515   ierr = MatScale(aa,a->B); CHKERRQ(ierr);
516   return 0;
517 }
518 
519 static int MatDestroy_MPIAIJ(PetscObject obj)
520 {
521   Mat        mat = (Mat) obj;
522   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
523   int        ierr;
524 #if defined(PETSC_LOG)
525   PLogObjectState(obj,"Rows=%d, Cols=%d",aij->M,aij->N);
526 #endif
527   PetscFree(aij->rowners);
528   ierr = MatDestroy(aij->A); CHKERRQ(ierr);
529   ierr = MatDestroy(aij->B); CHKERRQ(ierr);
530   if (aij->colmap) PetscFree(aij->colmap);
531   if (aij->garray) PetscFree(aij->garray);
532   if (aij->lvec)   VecDestroy(aij->lvec);
533   if (aij->Mvctx)  VecScatterDestroy(aij->Mvctx);
534   if (aij->rowvalues) PetscFree(aij->rowvalues);
535   PetscFree(aij);
536   PLogObjectDestroy(mat);
537   PetscHeaderDestroy(mat);
538   return 0;
539 }
540 #include "draw.h"
541 #include "pinclude/pviewer.h"
542 
543 static int MatView_MPIAIJ_Binary(Mat mat,Viewer viewer)
544 {
545   Mat_MPIAIJ  *aij = (Mat_MPIAIJ *) mat->data;
546   int         ierr;
547 
548   if (aij->size == 1) {
549     ierr = MatView(aij->A,viewer); CHKERRQ(ierr);
550   }
551   else SETERRQ(1,"MatView_MPIAIJ_Binary:Only uniprocessor output supported");
552   return 0;
553 }
554 
555 static int MatView_MPIAIJ_ASCIIorDraworMatlab(Mat mat,Viewer viewer)
556 {
557   Mat_MPIAIJ  *aij = (Mat_MPIAIJ *) mat->data;
558   Mat_SeqAIJ* C = (Mat_SeqAIJ*)aij->A->data;
559   int         ierr, format,shift = C->indexshift,rank;
560   PetscObject vobj = (PetscObject) viewer;
561   FILE        *fd;
562 
563   if (vobj->type == ASCII_FILE_VIEWER || vobj->type == ASCII_FILES_VIEWER) {
564     ierr = ViewerFileGetFormat_Private(viewer,&format);
565     if (format == FILE_FORMAT_INFO_DETAILED) {
566       int nz, nzalloc, mem, flg;
567       MPI_Comm_rank(mat->comm,&rank);
568       ierr = ViewerFileGetPointer(viewer,&fd); CHKERRQ(ierr);
569       ierr = MatGetInfo(mat,MAT_LOCAL,&nz,&nzalloc,&mem);
570       ierr = OptionsHasName(PETSC_NULL,"-mat_aij_no_inode",&flg); CHKERRQ(ierr);
571       MPIU_Seq_begin(mat->comm,1);
572       if (flg) fprintf(fd,"[%d] Local rows %d nz %d nz alloced %d mem %d, not using I-node routines\n",
573          rank,aij->m,nz,nzalloc,mem);
574       else fprintf(fd,"[%d] Local rows %d nz %d nz alloced %d mem %d, using I-node routines\n",
575          rank,aij->m,nz,nzalloc,mem);
576       ierr = MatGetInfo(aij->A,MAT_LOCAL,&nz,&nzalloc,&mem);
577       fprintf(fd,"[%d] on-diagonal part: nz %d \n",rank,nz);
578       ierr = MatGetInfo(aij->B,MAT_LOCAL,&nz,&nzalloc,&mem);
579       fprintf(fd,"[%d] off-diagonal part: nz %d \n",rank,nz);
580       fflush(fd);
581       MPIU_Seq_end(mat->comm,1);
582       ierr = VecScatterView(aij->Mvctx,viewer); CHKERRQ(ierr);
583       return 0;
584     }
585     else if (format == FILE_FORMAT_INFO) {
586       return 0;
587     }
588   }
589 
590   if (vobj->type == ASCII_FILE_VIEWER) {
591     ierr = ViewerFileGetPointer(viewer,&fd); CHKERRQ(ierr);
592     MPIU_Seq_begin(mat->comm,1);
593     fprintf(fd,"[%d] rows %d starts %d ends %d cols %d starts %d ends %d\n",
594            aij->rank,aij->m,aij->rstart,aij->rend,aij->n,aij->cstart,
595            aij->cend);
596     ierr = MatView(aij->A,viewer); CHKERRQ(ierr);
597     ierr = MatView(aij->B,viewer); CHKERRQ(ierr);
598     fflush(fd);
599     MPIU_Seq_end(mat->comm,1);
600   }
601   else {
602     int size = aij->size;
603     rank = aij->rank;
604     if (size == 1) {
605       ierr = MatView(aij->A,viewer); CHKERRQ(ierr);
606     }
607     else {
608       /* assemble the entire matrix onto first processor. */
609       Mat         A;
610       Mat_SeqAIJ *Aloc;
611       int         M = aij->M, N = aij->N,m,*ai,*aj,row,*cols,i,*ct;
612       Scalar      *a;
613 
614       if (!rank) {
615         ierr = MatCreateMPIAIJ(mat->comm,M,N,M,N,0,PETSC_NULL,0,PETSC_NULL,&A);
616                CHKERRQ(ierr);
617       }
618       else {
619         ierr = MatCreateMPIAIJ(mat->comm,0,0,M,N,0,PETSC_NULL,0,PETSC_NULL,&A);
620                CHKERRQ(ierr);
621       }
622       PLogObjectParent(mat,A);
623 
624       /* copy over the A part */
625       Aloc = (Mat_SeqAIJ*) aij->A->data;
626       m = Aloc->m; ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
627       row = aij->rstart;
628       for ( i=0; i<ai[m]+shift; i++ ) {aj[i] += aij->cstart + shift;}
629       for ( i=0; i<m; i++ ) {
630         ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],aj,a,INSERT_VALUES);CHKERRQ(ierr);
631         row++; a += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
632       }
633       aj = Aloc->j;
634       for ( i=0; i<ai[m]+shift; i++ ) {aj[i] -= aij->cstart + shift;}
635 
636       /* copy over the B part */
637       Aloc = (Mat_SeqAIJ*) aij->B->data;
638       m = Aloc->m;  ai = Aloc->i; aj = Aloc->j; a = Aloc->a;
639       row = aij->rstart;
640       ct = cols = (int *) PetscMalloc( (ai[m]+1)*sizeof(int) ); CHKPTRQ(cols);
641       for ( i=0; i<ai[m]+shift; i++ ) {cols[i] = aij->garray[aj[i]+shift];}
642       for ( i=0; i<m; i++ ) {
643         ierr = MatSetValues(A,1,&row,ai[i+1]-ai[i],cols,a,INSERT_VALUES);CHKERRQ(ierr);
644         row++; a += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
645       }
646       PetscFree(ct);
647       ierr = MatAssemblyBegin(A,FINAL_ASSEMBLY); CHKERRQ(ierr);
648       ierr = MatAssemblyEnd(A,FINAL_ASSEMBLY); CHKERRQ(ierr);
649       if (!rank) {
650         ierr = MatView(((Mat_MPIAIJ*)(A->data))->A,viewer); CHKERRQ(ierr);
651       }
652       ierr = MatDestroy(A); CHKERRQ(ierr);
653     }
654   }
655   return 0;
656 }
657 
658 static int MatView_MPIAIJ(PetscObject obj,Viewer viewer)
659 {
660   Mat         mat = (Mat) obj;
661   int         ierr;
662   PetscObject vobj = (PetscObject) viewer;
663 
664   if (!viewer) {
665     viewer = STDOUT_VIEWER_SELF; vobj = (PetscObject) viewer;
666   }
667   if (vobj->cookie == DRAW_COOKIE && vobj->type == NULLWINDOW) return 0;
668   else if (vobj->cookie == VIEWER_COOKIE && vobj->type == ASCII_FILE_VIEWER) {
669     ierr = MatView_MPIAIJ_ASCIIorDraworMatlab(mat,viewer); CHKERRQ(ierr);
670   }
671   else if (vobj->cookie == VIEWER_COOKIE && vobj->type == ASCII_FILES_VIEWER) {
672     ierr = MatView_MPIAIJ_ASCIIorDraworMatlab(mat,viewer); CHKERRQ(ierr);
673   }
674   else if (vobj->cookie == VIEWER_COOKIE && vobj->type == MATLAB_VIEWER) {
675     ierr = MatView_MPIAIJ_ASCIIorDraworMatlab(mat,viewer); CHKERRQ(ierr);
676   }
677   else if (vobj->cookie == DRAW_COOKIE) {
678     ierr = MatView_MPIAIJ_ASCIIorDraworMatlab(mat,viewer); CHKERRQ(ierr);
679   }
680   else if (vobj->type == BINARY_FILE_VIEWER) {
681     return MatView_MPIAIJ_Binary(mat,viewer);
682   }
683   return 0;
684 }
685 
686 extern int MatMarkDiag_SeqAIJ(Mat);
687 /*
688     This has to provide several versions.
689 
690      1) per sequential
691      2) a) use only local smoothing updating outer values only once.
692         b) local smoothing updating outer values each inner iteration
693      3) color updating out values betwen colors.
694 */
695 static int MatRelax_MPIAIJ(Mat matin,Vec bb,double omega,MatSORType flag,
696                            double fshift,int its,Vec xx)
697 {
698   Mat_MPIAIJ *mat = (Mat_MPIAIJ *) matin->data;
699   Mat        AA = mat->A, BB = mat->B;
700   Mat_SeqAIJ *A = (Mat_SeqAIJ *) AA->data, *B = (Mat_SeqAIJ *)BB->data;
701   Scalar     zero = 0.0,*b,*x,*xs,*ls,d,*v,sum,scale,*t,*ts;
702   int        ierr,*idx, *diag;
703   int        n = mat->n, m = mat->m, i,shift = A->indexshift;
704   Vec        tt;
705 
706   VecGetArray(xx,&x); VecGetArray(bb,&b); VecGetArray(mat->lvec,&ls);
707   xs = x + shift; /* shift by one for index start of 1 */
708   ls = ls + shift;
709   if (!A->diag) {if ((ierr = MatMarkDiag_SeqAIJ(AA))) return ierr;}
710   diag = A->diag;
711   if (flag == SOR_APPLY_UPPER || flag == SOR_APPLY_LOWER) {
712     SETERRQ(1,"MatRelax_MPIAIJ:Option not supported");
713   }
714   if (flag & SOR_EISENSTAT) {
715     /* Let  A = L + U + D; where L is lower trianglar,
716     U is upper triangular, E is diagonal; This routine applies
717 
718             (L + E)^{-1} A (U + E)^{-1}
719 
720     to a vector efficiently using Eisenstat's trick. This is for
721     the case of SSOR preconditioner, so E is D/omega where omega
722     is the relaxation factor.
723     */
724     ierr = VecDuplicate(xx,&tt); CHKERRQ(ierr);
725     PLogObjectParent(matin,tt);
726     VecGetArray(tt,&t);
727     scale = (2.0/omega) - 1.0;
728     /*  x = (E + U)^{-1} b */
729     VecSet(&zero,mat->lvec);
730     ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
731                               mat->Mvctx); CHKERRQ(ierr);
732     for ( i=m-1; i>-1; i-- ) {
733       n    = A->i[i+1] - diag[i] - 1;
734       idx  = A->j + diag[i] + !shift;
735       v    = A->a + diag[i] + !shift;
736       sum  = b[i];
737       SPARSEDENSEMDOT(sum,xs,v,idx,n);
738       d    = fshift + A->a[diag[i]+shift];
739       n    = B->i[i+1] - B->i[i];
740       idx  = B->j + B->i[i] + shift;
741       v    = B->a + B->i[i] + shift;
742       SPARSEDENSEMDOT(sum,ls,v,idx,n);
743       x[i] = omega*(sum/d);
744     }
745     ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
746                             mat->Mvctx); CHKERRQ(ierr);
747 
748     /*  t = b - (2*E - D)x */
749     v = A->a;
750     for ( i=0; i<m; i++ ) { t[i] = b[i] - scale*(v[*diag++ + shift])*x[i]; }
751 
752     /*  t = (E + L)^{-1}t */
753     ts = t + shift; /* shifted by one for index start of a or mat->j*/
754     diag = A->diag;
755     VecSet(&zero,mat->lvec);
756     ierr = VecPipelineBegin(tt,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
757                                                  mat->Mvctx); CHKERRQ(ierr);
758     for ( i=0; i<m; i++ ) {
759       n    = diag[i] - A->i[i];
760       idx  = A->j + A->i[i] + shift;
761       v    = A->a + A->i[i] + shift;
762       sum  = t[i];
763       SPARSEDENSEMDOT(sum,ts,v,idx,n);
764       d    = fshift + A->a[diag[i]+shift];
765       n    = B->i[i+1] - B->i[i];
766       idx  = B->j + B->i[i] + shift;
767       v    = B->a + B->i[i] + shift;
768       SPARSEDENSEMDOT(sum,ls,v,idx,n);
769       t[i] = omega*(sum/d);
770     }
771     ierr = VecPipelineEnd(tt,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
772                                                     mat->Mvctx); CHKERRQ(ierr);
773     /*  x = x + t */
774     for ( i=0; i<m; i++ ) { x[i] += t[i]; }
775     VecDestroy(tt);
776     return 0;
777   }
778 
779 
780   if ((flag & SOR_SYMMETRIC_SWEEP) == SOR_SYMMETRIC_SWEEP){
781     if (flag & SOR_ZERO_INITIAL_GUESS) {
782       VecSet(&zero,mat->lvec); VecSet(&zero,xx);
783     }
784     else {
785       ierr=VecScatterBegin(xx,mat->lvec,INSERT_VALUES,SCATTER_UP,mat->Mvctx);
786       CHKERRQ(ierr);
787       ierr = VecScatterEnd(xx,mat->lvec,INSERT_VALUES,SCATTER_UP,mat->Mvctx);
788       CHKERRQ(ierr);
789     }
790     while (its--) {
791       /* go down through the rows */
792       ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
793                               mat->Mvctx); CHKERRQ(ierr);
794       for ( i=0; i<m; i++ ) {
795         n    = A->i[i+1] - A->i[i];
796         idx  = A->j + A->i[i] + shift;
797         v    = A->a + A->i[i] + shift;
798         sum  = b[i];
799         SPARSEDENSEMDOT(sum,xs,v,idx,n);
800         d    = fshift + A->a[diag[i]+shift];
801         n    = B->i[i+1] - B->i[i];
802         idx  = B->j + B->i[i] + shift;
803         v    = B->a + B->i[i] + shift;
804         SPARSEDENSEMDOT(sum,ls,v,idx,n);
805         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
806       }
807       ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
808                             mat->Mvctx); CHKERRQ(ierr);
809       /* come up through the rows */
810       ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
811                               mat->Mvctx); CHKERRQ(ierr);
812       for ( i=m-1; i>-1; i-- ) {
813         n    = A->i[i+1] - A->i[i];
814         idx  = A->j + A->i[i] + shift;
815         v    = A->a + A->i[i] + shift;
816         sum  = b[i];
817         SPARSEDENSEMDOT(sum,xs,v,idx,n);
818         d    = fshift + A->a[diag[i]+shift];
819         n    = B->i[i+1] - B->i[i];
820         idx  = B->j + B->i[i] + shift;
821         v    = B->a + B->i[i] + shift;
822         SPARSEDENSEMDOT(sum,ls,v,idx,n);
823         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
824       }
825       ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
826                             mat->Mvctx); CHKERRQ(ierr);
827     }
828   }
829   else if (flag & SOR_FORWARD_SWEEP){
830     if (flag & SOR_ZERO_INITIAL_GUESS) {
831       VecSet(&zero,mat->lvec);
832       ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
833                               mat->Mvctx); CHKERRQ(ierr);
834       for ( i=0; i<m; i++ ) {
835         n    = diag[i] - A->i[i];
836         idx  = A->j + A->i[i] + shift;
837         v    = A->a + A->i[i] + shift;
838         sum  = b[i];
839         SPARSEDENSEMDOT(sum,xs,v,idx,n);
840         d    = fshift + A->a[diag[i]+shift];
841         n    = B->i[i+1] - B->i[i];
842         idx  = B->j + B->i[i] + shift;
843         v    = B->a + B->i[i] + shift;
844         SPARSEDENSEMDOT(sum,ls,v,idx,n);
845         x[i] = omega*(sum/d);
846       }
847       ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
848                             mat->Mvctx); CHKERRQ(ierr);
849       its--;
850     }
851     while (its--) {
852       ierr=VecScatterBegin(xx,mat->lvec,INSERT_VALUES,SCATTER_UP,mat->Mvctx);
853       CHKERRQ(ierr);
854       ierr = VecScatterEnd(xx,mat->lvec,INSERT_VALUES,SCATTER_UP,mat->Mvctx);
855       CHKERRQ(ierr);
856       ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
857                               mat->Mvctx); CHKERRQ(ierr);
858       for ( i=0; i<m; i++ ) {
859         n    = A->i[i+1] - A->i[i];
860         idx  = A->j + A->i[i] + shift;
861         v    = A->a + A->i[i] + shift;
862         sum  = b[i];
863         SPARSEDENSEMDOT(sum,xs,v,idx,n);
864         d    = fshift + A->a[diag[i]+shift];
865         n    = B->i[i+1] - B->i[i];
866         idx  = B->j + B->i[i] + shift;
867         v    = B->a + B->i[i] + shift;
868         SPARSEDENSEMDOT(sum,ls,v,idx,n);
869         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
870       }
871       ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_DOWN,
872                             mat->Mvctx); CHKERRQ(ierr);
873     }
874   }
875   else if (flag & SOR_BACKWARD_SWEEP){
876     if (flag & SOR_ZERO_INITIAL_GUESS) {
877       VecSet(&zero,mat->lvec);
878       ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
879                               mat->Mvctx); CHKERRQ(ierr);
880       for ( i=m-1; i>-1; i-- ) {
881         n    = A->i[i+1] - diag[i] - 1;
882         idx  = A->j + diag[i] + !shift;
883         v    = A->a + diag[i] + !shift;
884         sum  = b[i];
885         SPARSEDENSEMDOT(sum,xs,v,idx,n);
886         d    = fshift + A->a[diag[i]+shift];
887         n    = B->i[i+1] - B->i[i];
888         idx  = B->j + B->i[i] + shift;
889         v    = B->a + B->i[i] + shift;
890         SPARSEDENSEMDOT(sum,ls,v,idx,n);
891         x[i] = omega*(sum/d);
892       }
893       ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
894                             mat->Mvctx); CHKERRQ(ierr);
895       its--;
896     }
897     while (its--) {
898       ierr = VecScatterBegin(xx,mat->lvec,INSERT_VALUES,SCATTER_DOWN,
899                             mat->Mvctx); CHKERRQ(ierr);
900       ierr = VecScatterEnd(xx,mat->lvec,INSERT_VALUES,SCATTER_DOWN,
901                             mat->Mvctx); CHKERRQ(ierr);
902       ierr = VecPipelineBegin(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
903                               mat->Mvctx); CHKERRQ(ierr);
904       for ( i=m-1; i>-1; i-- ) {
905         n    = A->i[i+1] - A->i[i];
906         idx  = A->j + A->i[i] + shift;
907         v    = A->a + A->i[i] + shift;
908         sum  = b[i];
909         SPARSEDENSEMDOT(sum,xs,v,idx,n);
910         d    = fshift + A->a[diag[i]+shift];
911         n    = B->i[i+1] - B->i[i];
912         idx  = B->j + B->i[i] + shift;
913         v    = B->a + B->i[i] + shift;
914         SPARSEDENSEMDOT(sum,ls,v,idx,n);
915         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
916       }
917       ierr = VecPipelineEnd(xx,mat->lvec,INSERT_VALUES,PIPELINE_UP,
918                             mat->Mvctx); CHKERRQ(ierr);
919     }
920   }
921   else if ((flag & SOR_LOCAL_SYMMETRIC_SWEEP) == SOR_LOCAL_SYMMETRIC_SWEEP){
922     if (flag & SOR_ZERO_INITIAL_GUESS) {
923       return MatRelax(mat->A,bb,omega,flag,fshift,its,xx);
924     }
925     ierr=VecScatterBegin(xx,mat->lvec,INSERT_VALUES,SCATTER_ALL,mat->Mvctx);
926     CHKERRQ(ierr);
927     ierr = VecScatterEnd(xx,mat->lvec,INSERT_VALUES,SCATTER_ALL,mat->Mvctx);
928     CHKERRQ(ierr);
929     while (its--) {
930       /* go down through the rows */
931       for ( i=0; i<m; i++ ) {
932         n    = A->i[i+1] - A->i[i];
933         idx  = A->j + A->i[i] + shift;
934         v    = A->a + A->i[i] + shift;
935         sum  = b[i];
936         SPARSEDENSEMDOT(sum,xs,v,idx,n);
937         d    = fshift + A->a[diag[i]+shift];
938         n    = B->i[i+1] - B->i[i];
939         idx  = B->j + B->i[i] + shift;
940         v    = B->a + B->i[i] + shift;
941         SPARSEDENSEMDOT(sum,ls,v,idx,n);
942         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
943       }
944       /* come up through the rows */
945       for ( i=m-1; i>-1; i-- ) {
946         n    = A->i[i+1] - A->i[i];
947         idx  = A->j + A->i[i] + shift;
948         v    = A->a + A->i[i] + shift;
949         sum  = b[i];
950         SPARSEDENSEMDOT(sum,xs,v,idx,n);
951         d    = fshift + A->a[diag[i]+shift];
952         n    = B->i[i+1] - B->i[i];
953         idx  = B->j + B->i[i] + shift;
954         v    = B->a + B->i[i] + shift;
955         SPARSEDENSEMDOT(sum,ls,v,idx,n);
956         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
957       }
958     }
959   }
960   else if (flag & SOR_LOCAL_FORWARD_SWEEP){
961     if (flag & SOR_ZERO_INITIAL_GUESS) {
962       return MatRelax(mat->A,bb,omega,flag,fshift,its,xx);
963     }
964     ierr=VecScatterBegin(xx,mat->lvec,INSERT_VALUES,SCATTER_ALL,mat->Mvctx);
965     CHKERRQ(ierr);
966     ierr = VecScatterEnd(xx,mat->lvec,INSERT_VALUES,SCATTER_ALL,mat->Mvctx);
967     CHKERRQ(ierr);
968     while (its--) {
969       for ( i=0; i<m; i++ ) {
970         n    = A->i[i+1] - A->i[i];
971         idx  = A->j + A->i[i] + shift;
972         v    = A->a + A->i[i] + shift;
973         sum  = b[i];
974         SPARSEDENSEMDOT(sum,xs,v,idx,n);
975         d    = fshift + A->a[diag[i]+shift];
976         n    = B->i[i+1] - B->i[i];
977         idx  = B->j + B->i[i] + shift;
978         v    = B->a + B->i[i] + shift;
979         SPARSEDENSEMDOT(sum,ls,v,idx,n);
980         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
981       }
982     }
983   }
984   else if (flag & SOR_LOCAL_BACKWARD_SWEEP){
985     if (flag & SOR_ZERO_INITIAL_GUESS) {
986       return MatRelax(mat->A,bb,omega,flag,fshift,its,xx);
987     }
988     ierr = VecScatterBegin(xx,mat->lvec,INSERT_VALUES,SCATTER_ALL,
989                             mat->Mvctx); CHKERRQ(ierr);
990     ierr = VecScatterEnd(xx,mat->lvec,INSERT_VALUES,SCATTER_ALL,
991                             mat->Mvctx); CHKERRQ(ierr);
992     while (its--) {
993       for ( i=m-1; i>-1; i-- ) {
994         n    = A->i[i+1] - A->i[i];
995         idx  = A->j + A->i[i] + shift;
996         v    = A->a + A->i[i] + shift;
997         sum  = b[i];
998         SPARSEDENSEMDOT(sum,xs,v,idx,n);
999         d    = fshift + A->a[diag[i]+shift];
1000         n    = B->i[i+1] - B->i[i];
1001         idx  = B->j + B->i[i] + shift;
1002         v    = B->a + B->i[i] + shift;
1003         SPARSEDENSEMDOT(sum,ls,v,idx,n);
1004         x[i] = (1. - omega)*x[i] + omega*(sum/d + x[i]);
1005       }
1006     }
1007   }
1008   return 0;
1009 }
1010 
1011 static int MatGetInfo_MPIAIJ(Mat matin,MatInfoType flag,int *nz,
1012                              int *nzalloc,int *mem)
1013 {
1014   Mat_MPIAIJ *mat = (Mat_MPIAIJ *) matin->data;
1015   Mat        A = mat->A, B = mat->B;
1016   int        ierr, isend[3], irecv[3], nzA, nzallocA, memA;
1017 
1018   ierr = MatGetInfo(A,MAT_LOCAL,&nzA,&nzallocA,&memA); CHKERRQ(ierr);
1019   ierr = MatGetInfo(B,MAT_LOCAL,&isend[0],&isend[1],&isend[2]); CHKERRQ(ierr);
1020   isend[0] += nzA; isend[1] += nzallocA; isend[2] += memA;
1021   if (flag == MAT_LOCAL) {
1022     *nz = isend[0]; *nzalloc = isend[1]; *mem = isend[2];
1023   } else if (flag == MAT_GLOBAL_MAX) {
1024     MPI_Allreduce( isend, irecv,3,MPI_INT,MPI_MAX,matin->comm);
1025     *nz = irecv[0]; *nzalloc = irecv[1]; *mem = irecv[2];
1026   } else if (flag == MAT_GLOBAL_SUM) {
1027     MPI_Allreduce( isend, irecv,3,MPI_INT,MPI_SUM,matin->comm);
1028     *nz = irecv[0]; *nzalloc = irecv[1]; *mem = irecv[2];
1029   }
1030   return 0;
1031 }
1032 
1033 extern int MatLUFactorSymbolic_MPIAIJ(Mat,IS,IS,double,Mat*);
1034 extern int MatLUFactorNumeric_MPIAIJ(Mat,Mat*);
1035 extern int MatLUFactor_MPIAIJ(Mat,IS,IS,double);
1036 extern int MatILUFactorSymbolic_MPIAIJ(Mat,IS,IS,double,int,Mat *);
1037 extern int MatSolve_MPIAIJ(Mat,Vec,Vec);
1038 extern int MatSolveAdd_MPIAIJ(Mat,Vec,Vec,Vec);
1039 extern int MatSolveTrans_MPIAIJ(Mat,Vec,Vec);
1040 extern int MatSolveTransAdd_MPIAIJ(Mat,Vec,Vec,Vec);
1041 
1042 static int MatSetOption_MPIAIJ(Mat A,MatOption op)
1043 {
1044   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
1045 
1046   if (op == NO_NEW_NONZERO_LOCATIONS ||
1047       op == YES_NEW_NONZERO_LOCATIONS ||
1048       op == COLUMNS_SORTED ||
1049       op == ROW_ORIENTED) {
1050         MatSetOption(a->A,op);
1051         MatSetOption(a->B,op);
1052   }
1053   else if (op == ROWS_SORTED ||
1054            op == SYMMETRIC_MATRIX ||
1055            op == STRUCTURALLY_SYMMETRIC_MATRIX ||
1056            op == YES_NEW_DIAGONALS)
1057     PLogInfo((PetscObject)A,"Info:MatSetOption_MPIAIJ:Option ignored\n");
1058   else if (op == COLUMN_ORIENTED) {
1059     a->roworiented = 0;
1060     MatSetOption(a->A,op);
1061     MatSetOption(a->B,op);
1062   }
1063   else if (op == NO_NEW_DIAGONALS)
1064     {SETERRQ(PETSC_ERR_SUP,"MatSetOption_MPIAIJ:NO_NEW_DIAGONALS");}
1065   else
1066     {SETERRQ(PETSC_ERR_SUP,"MatSetOption_MPIAIJ:unknown option");}
1067   return 0;
1068 }
1069 
1070 static int MatGetSize_MPIAIJ(Mat matin,int *m,int *n)
1071 {
1072   Mat_MPIAIJ *mat = (Mat_MPIAIJ *) matin->data;
1073   *m = mat->M; *n = mat->N;
1074   return 0;
1075 }
1076 
1077 static int MatGetLocalSize_MPIAIJ(Mat matin,int *m,int *n)
1078 {
1079   Mat_MPIAIJ *mat = (Mat_MPIAIJ *) matin->data;
1080   *m = mat->m; *n = mat->N;
1081   return 0;
1082 }
1083 
1084 static int MatGetOwnershipRange_MPIAIJ(Mat matin,int *m,int *n)
1085 {
1086   Mat_MPIAIJ *mat = (Mat_MPIAIJ *) matin->data;
1087   *m = mat->rstart; *n = mat->rend;
1088   return 0;
1089 }
1090 
1091 extern int MatGetRow_SeqAIJ(Mat,int,int*,int**,Scalar**);
1092 extern int MatRestoreRow_SeqAIJ(Mat,int,int*,int**,Scalar**);
1093 
1094 int MatGetRow_MPIAIJ(Mat matin,int row,int *nz,int **idx,Scalar **v)
1095 {
1096   Mat_MPIAIJ *mat = (Mat_MPIAIJ *) matin->data;
1097   Scalar     *vworkA, *vworkB, **pvA, **pvB,*v_p;
1098   int        i, ierr, *cworkA, *cworkB, **pcA, **pcB, cstart = mat->cstart;
1099   int        nztot, nzA, nzB, lrow, rstart = mat->rstart, rend = mat->rend;
1100   int        *cmap, *idx_p;
1101 
1102   if (mat->getrowactive == PETSC_TRUE) SETERRQ(1,"MatGetRow_MPIAIJ:Already active");
1103   mat->getrowactive = PETSC_TRUE;
1104 
1105   if (!mat->rowvalues && (idx || v)) {
1106     /*
1107         allocate enough space to hold information from the longest row.
1108     */
1109     Mat_SeqAIJ *Aa = (Mat_SeqAIJ *) mat->A->data,*Ba = (Mat_SeqAIJ *) mat->B->data;
1110     int     max = 1,n = mat->n,tmp;
1111     for ( i=0; i<n; i++ ) {
1112       tmp = Aa->i[i+1] - Aa->i[i] + Ba->i[i+1] - Ba->i[i];
1113       if (max < tmp) { max = tmp; }
1114     }
1115     mat->rowvalues = (Scalar *) PetscMalloc( max*(sizeof(int)+sizeof(Scalar)));
1116     CHKPTRQ(mat->rowvalues);
1117     mat->rowindices = (int *) (mat->rowvalues + max);
1118   }
1119 
1120 
1121   if (row < rstart || row >= rend) SETERRQ(1,"MatGetRow_MPIAIJ:Only local rows")
1122   lrow = row - rstart;
1123 
1124   pvA = &vworkA; pcA = &cworkA; pvB = &vworkB; pcB = &cworkB;
1125   if (!v)   {pvA = 0; pvB = 0;}
1126   if (!idx) {pcA = 0; if (!v) pcB = 0;}
1127   ierr = MatGetRow_SeqAIJ(mat->A,lrow,&nzA,pcA,pvA); CHKERRQ(ierr);
1128   ierr = MatGetRow_SeqAIJ(mat->B,lrow,&nzB,pcB,pvB); CHKERRQ(ierr);
1129   nztot = nzA + nzB;
1130 
1131   cmap  = mat->garray;
1132   if (v  || idx) {
1133     if (nztot) {
1134       /* Sort by increasing column numbers, assuming A and B already sorted */
1135       int imark = -1;
1136       if (v) {
1137         *v = v_p = mat->rowvalues;
1138         for ( i=0; i<nzB; i++ ) {
1139           if (cmap[cworkB[i]] < cstart)   v_p[i] = vworkB[i];
1140           else break;
1141         }
1142         imark = i;
1143         for ( i=0; i<nzA; i++ )     v_p[imark+i] = vworkA[i];
1144         for ( i=imark; i<nzB; i++ ) v_p[nzA+i]   = vworkB[i];
1145       }
1146       if (idx) {
1147         *idx = idx_p = mat->rowindices;
1148         if (imark > -1) {
1149           for ( i=0; i<imark; i++ ) {
1150             idx_p[i] = cmap[cworkB[i]];
1151           }
1152         } else {
1153           for ( i=0; i<nzB; i++ ) {
1154             if (cmap[cworkB[i]] < cstart)   idx_p[i] = cmap[cworkB[i]];
1155             else break;
1156           }
1157           imark = i;
1158         }
1159         for ( i=0; i<nzA; i++ )     idx_p[imark+i] = cstart + cworkA[i];
1160         for ( i=imark; i<nzB; i++ ) idx_p[nzA+i]   = cmap[cworkB[i]];
1161       }
1162     }
1163     else {*idx = 0; *v=0;}
1164   }
1165   *nz = nztot;
1166   ierr = MatRestoreRow_SeqAIJ(mat->A,lrow,&nzA,pcA,pvA); CHKERRQ(ierr);
1167   ierr = MatRestoreRow_SeqAIJ(mat->B,lrow,&nzB,pcB,pvB); CHKERRQ(ierr);
1168   return 0;
1169 }
1170 
1171 int MatRestoreRow_MPIAIJ(Mat mat,int row,int *nz,int **idx,Scalar **v)
1172 {
1173   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
1174   if (aij->getrowactive == PETSC_FALSE) {
1175     SETERRQ(1,"MatRestoreRow_MPIAIJ:MatGetRow not called");
1176   }
1177   aij->getrowactive = PETSC_FALSE;
1178   return 0;
1179 }
1180 
1181 static int MatNorm_MPIAIJ(Mat mat,NormType type,double *norm)
1182 {
1183   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
1184   Mat_SeqAIJ *amat = (Mat_SeqAIJ*) aij->A->data, *bmat = (Mat_SeqAIJ*) aij->B->data;
1185   int        ierr, i, j, cstart = aij->cstart,shift = amat->indexshift;
1186   double     sum = 0.0;
1187   Scalar     *v;
1188 
1189   if (aij->size == 1) {
1190     ierr =  MatNorm(aij->A,type,norm); CHKERRQ(ierr);
1191   } else {
1192     if (type == NORM_FROBENIUS) {
1193       v = amat->a;
1194       for (i=0; i<amat->nz; i++ ) {
1195 #if defined(PETSC_COMPLEX)
1196         sum += real(conj(*v)*(*v)); v++;
1197 #else
1198         sum += (*v)*(*v); v++;
1199 #endif
1200       }
1201       v = bmat->a;
1202       for (i=0; i<bmat->nz; i++ ) {
1203 #if defined(PETSC_COMPLEX)
1204         sum += real(conj(*v)*(*v)); v++;
1205 #else
1206         sum += (*v)*(*v); v++;
1207 #endif
1208       }
1209       MPI_Allreduce(&sum,norm,1,MPI_DOUBLE,MPI_SUM,mat->comm);
1210       *norm = sqrt(*norm);
1211     }
1212     else if (type == NORM_1) { /* max column norm */
1213       double *tmp, *tmp2;
1214       int    *jj, *garray = aij->garray;
1215       tmp  = (double *) PetscMalloc( aij->N*sizeof(double) ); CHKPTRQ(tmp);
1216       tmp2 = (double *) PetscMalloc( aij->N*sizeof(double) ); CHKPTRQ(tmp2);
1217       PetscMemzero(tmp,aij->N*sizeof(double));
1218       *norm = 0.0;
1219       v = amat->a; jj = amat->j;
1220       for ( j=0; j<amat->nz; j++ ) {
1221         tmp[cstart + *jj++ + shift] += PetscAbsScalar(*v);  v++;
1222       }
1223       v = bmat->a; jj = bmat->j;
1224       for ( j=0; j<bmat->nz; j++ ) {
1225         tmp[garray[*jj++ + shift]] += PetscAbsScalar(*v); v++;
1226       }
1227       MPI_Allreduce(tmp,tmp2,aij->N,MPI_DOUBLE,MPI_SUM,mat->comm);
1228       for ( j=0; j<aij->N; j++ ) {
1229         if (tmp2[j] > *norm) *norm = tmp2[j];
1230       }
1231       PetscFree(tmp); PetscFree(tmp2);
1232     }
1233     else if (type == NORM_INFINITY) { /* max row norm */
1234       double ntemp = 0.0;
1235       for ( j=0; j<amat->m; j++ ) {
1236         v = amat->a + amat->i[j] + shift;
1237         sum = 0.0;
1238         for ( i=0; i<amat->i[j+1]-amat->i[j]; i++ ) {
1239           sum += PetscAbsScalar(*v); v++;
1240         }
1241         v = bmat->a + bmat->i[j] + shift;
1242         for ( i=0; i<bmat->i[j+1]-bmat->i[j]; i++ ) {
1243           sum += PetscAbsScalar(*v); v++;
1244         }
1245         if (sum > ntemp) ntemp = sum;
1246       }
1247       MPI_Allreduce(&ntemp,norm,1,MPI_DOUBLE,MPI_MAX,mat->comm);
1248     }
1249     else {
1250       SETERRQ(1,"MatNorm_MPIAIJ:No support for two norm");
1251     }
1252   }
1253   return 0;
1254 }
1255 
1256 static int MatTranspose_MPIAIJ(Mat A,Mat *matout)
1257 {
1258   Mat_MPIAIJ *a = (Mat_MPIAIJ *) A->data;
1259   Mat_SeqAIJ *Aloc = (Mat_SeqAIJ *) a->A->data;
1260   int        ierr,shift = Aloc->indexshift;
1261   Mat        B;
1262   int        M = a->M, N = a->N,m,*ai,*aj,row,*cols,i,*ct;
1263   Scalar     *array;
1264 
1265   if (matout == PETSC_NULL && M != N)
1266     SETERRQ(1,"MatTranspose_MPIAIJ:Square matrix only for in-place");
1267   ierr = MatCreateMPIAIJ(A->comm,PETSC_DECIDE,PETSC_DECIDE,N,M,0,PETSC_NULL,0,
1268          PETSC_NULL,&B); CHKERRQ(ierr);
1269 
1270   /* copy over the A part */
1271   Aloc = (Mat_SeqAIJ*) a->A->data;
1272   m = Aloc->m; ai = Aloc->i; aj = Aloc->j; array = Aloc->a;
1273   row = a->rstart;
1274   for ( i=0; i<ai[m]+shift; i++ ) {aj[i] += a->cstart + shift;}
1275   for ( i=0; i<m; i++ ) {
1276     ierr = MatSetValues(B,ai[i+1]-ai[i],aj,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1277     row++; array += ai[i+1]-ai[i]; aj += ai[i+1]-ai[i];
1278   }
1279   aj = Aloc->j;
1280   for ( i=0; i<ai[m]+shift; i++ ) {aj[i] -= a->cstart + shift;}
1281 
1282   /* copy over the B part */
1283   Aloc = (Mat_SeqAIJ*) a->B->data;
1284   m = Aloc->m;  ai = Aloc->i; aj = Aloc->j; array = Aloc->a;
1285   row = a->rstart;
1286   ct = cols = (int *) PetscMalloc( (1+ai[m]-shift)*sizeof(int) ); CHKPTRQ(cols);
1287   for ( i=0; i<ai[m]+shift; i++ ) {cols[i] = a->garray[aj[i]+shift];}
1288   for ( i=0; i<m; i++ ) {
1289     ierr = MatSetValues(B,ai[i+1]-ai[i],cols,1,&row,array,INSERT_VALUES);CHKERRQ(ierr);
1290     row++; array += ai[i+1]-ai[i]; cols += ai[i+1]-ai[i];
1291   }
1292   PetscFree(ct);
1293   ierr = MatAssemblyBegin(B,FINAL_ASSEMBLY); CHKERRQ(ierr);
1294   ierr = MatAssemblyEnd(B,FINAL_ASSEMBLY); CHKERRQ(ierr);
1295   if (matout != PETSC_NULL) {
1296     *matout = B;
1297   } else {
1298     /* This isn't really an in-place transpose .... but free data structures from a */
1299     PetscFree(a->rowners);
1300     ierr = MatDestroy(a->A); CHKERRQ(ierr);
1301     ierr = MatDestroy(a->B); CHKERRQ(ierr);
1302     if (a->colmap) PetscFree(a->colmap);
1303     if (a->garray) PetscFree(a->garray);
1304     if (a->lvec) VecDestroy(a->lvec);
1305     if (a->Mvctx) VecScatterDestroy(a->Mvctx);
1306     PetscFree(a);
1307     PetscMemcpy(A,B,sizeof(struct _Mat));
1308     PetscHeaderDestroy(B);
1309   }
1310   return 0;
1311 }
1312 
1313 extern int MatPrintHelp_SeqAIJ(Mat);
1314 static int MatPrintHelp_MPIAIJ(Mat A)
1315 {
1316   Mat_MPIAIJ *a   = (Mat_MPIAIJ*) A->data;
1317 
1318   if (!a->rank) return MatPrintHelp_SeqAIJ(a->A);
1319   else return 0;
1320 }
1321 
1322 extern int MatConvert_MPIAIJ(Mat,MatType,Mat *);
1323 static int MatConvertSameType_MPIAIJ(Mat,Mat *,int);
1324 extern int MatIncreaseOverlap_MPIAIJ(Mat , int, IS *, int);
1325 int MatGetSubMatrices_MPIAIJ (Mat ,int , IS *,IS *,MatGetSubMatrixCall,Mat **);
1326 /* -------------------------------------------------------------------*/
1327 static struct _MatOps MatOps = {MatSetValues_MPIAIJ,
1328        MatGetRow_MPIAIJ,MatRestoreRow_MPIAIJ,
1329        MatMult_MPIAIJ,MatMultAdd_MPIAIJ,
1330        MatMultTrans_MPIAIJ,MatMultTransAdd_MPIAIJ,
1331        MatSolve_MPIAIJ,MatSolveAdd_MPIAIJ,
1332        MatSolveTrans_MPIAIJ,MatSolveTransAdd_MPIAIJ,
1333        MatLUFactor_MPIAIJ,0,
1334        MatRelax_MPIAIJ,
1335        MatTranspose_MPIAIJ,
1336        MatGetInfo_MPIAIJ,0,
1337        MatGetDiagonal_MPIAIJ,0,MatNorm_MPIAIJ,
1338        MatAssemblyBegin_MPIAIJ,MatAssemblyEnd_MPIAIJ,
1339        0,
1340        MatSetOption_MPIAIJ,MatZeroEntries_MPIAIJ,MatZeroRows_MPIAIJ,
1341        MatGetReordering_MPIAIJ,
1342        MatLUFactorSymbolic_MPIAIJ,MatLUFactorNumeric_MPIAIJ,0,0,
1343        MatGetSize_MPIAIJ,MatGetLocalSize_MPIAIJ,MatGetOwnershipRange_MPIAIJ,
1344        MatILUFactorSymbolic_MPIAIJ,0,
1345        0,0,MatConvert_MPIAIJ,0,0,MatConvertSameType_MPIAIJ,0,0,
1346        0,0,0,
1347        MatGetSubMatrices_MPIAIJ,MatIncreaseOverlap_MPIAIJ,MatGetValues_MPIAIJ,0,
1348        MatPrintHelp_MPIAIJ,
1349        MatScale_MPIAIJ};
1350 
1351 /*@C
1352    MatCreateMPIAIJ - Creates a sparse parallel matrix in AIJ format
1353    (the default parallel PETSc format).  For good matrix assembly performance
1354    the user should preallocate the matrix storage by setting the parameters
1355    d_nz (or d_nnz) and o_nz (or o_nnz).  By setting these parameters accurately,
1356    performance can be increased by more than a factor of 50.
1357 
1358    Input Parameters:
1359 .  comm - MPI communicator
1360 .  m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
1361 .  n - number of local columns (or PETSC_DECIDE to have calculated
1362            if N is given)
1363 .  M - number of global rows (or PETSC_DECIDE to have calculated if m is given)
1364 .  N - number of global columns (or PETSC_DECIDE to have calculated
1365            if n is given)
1366 .  d_nz - number of nonzeros per row in diagonal portion of local submatrix
1367            (same for all local rows)
1368 .  d_nzz - number of nonzeros per row in diagonal portion of local submatrix
1369            or null (possibly different for each row).  You must leave room
1370            for the diagonal entry even if it is zero.
1371 .  o_nz - number of nonzeros per row in off-diagonal portion of local
1372            submatrix (same for all local rows).
1373 .  o_nzz - number of nonzeros per row in off-diagonal portion of local
1374            submatrix or null (possibly different for each row).
1375 
1376    Output Parameter:
1377 .  newmat - the matrix
1378 
1379    Notes:
1380    The AIJ format (also called the Yale sparse matrix format or
1381    compressed row storage), is fully compatible with standard Fortran 77
1382    storage.  That is, the stored row and column indices can begin at
1383    either one (as in Fortran) or zero.  See the users manual for details.
1384 
1385    The user MUST specify either the local or global matrix dimensions
1386    (possibly both).
1387 
1388    By default, this format uses inodes (identical nodes) when possible.
1389    We search for consecutive rows with the same nonzero structure, thereby
1390    reusing matrix information to achieve increased efficiency.
1391 
1392    Options Database Keys:
1393 $    -mat_aij_no_inode  - Do not use inodes
1394 $    -mat_aij_inode_limit <limit> - Set inode limit.
1395 $        (max limit=5)
1396 $    -mat_aij_oneindex - Internally use indexing starting at 1
1397 $        rather than 0.  Note: When calling MatSetValues(),
1398 $        the user still MUST index entries starting at 0!
1399 
1400    Storage Information:
1401    For a square global matrix we define each processor's diagonal portion
1402    to be its local rows and the corresponding columns (a square submatrix);
1403    each processor's off-diagonal portion encompasses the remainder of the
1404    local matrix (a rectangular submatrix).
1405 
1406    The user can specify preallocated storage for the diagonal part of
1407    the local submatrix with either d_nz or d_nnz (not both).  Set
1408    d_nz=PETSC_DEFAULT and d_nnz=PETSC_NULL for PETSc to control dynamic
1409    memory allocation.  Likewise, specify preallocated storage for the
1410    off-diagonal part of the local submatrix with o_nz or o_nnz (not both).
1411 
1412    Consider a processor that owns rows 3, 4 and 5 of a parallel matrix. In
1413    the figure below we depict these three local rows and all columns (0-11).
1414 
1415 $          0 1 2 3 4 5 6 7 8 9 10 11
1416 $         -------------------
1417 $  row 3  |  o o o d d d o o o o o o
1418 $  row 4  |  o o o d d d o o o o o o
1419 $  row 5  |  o o o d d d o o o o o o
1420 $         -------------------
1421 $
1422 
1423    Thus, any entries in the d locations are stored in the d (diagonal)
1424    submatrix, and any entries in the o locations are stored in the
1425    o (off-diagonal) submatrix.  Note that the d and the o submatrices are
1426    stored simply in the MATSEQAIJ format for compressed row storage.
1427 
1428    Now d_nz should indicate the number of nonzeros per row in the d matrix,
1429    and o_nz should indicate the number of nonzeros per row in the o matrix.
1430    In general, for PDE problems in which most nonzeros are near the diagonal,
1431    one expects d_nz >> o_nz.   For additional details, see the users manual
1432    chapter on matrices and the file $(PETSC_DIR)/Performance.
1433 
1434 .keywords: matrix, aij, compressed row, sparse, parallel
1435 
1436 .seealso: MatCreate(), MatCreateSeqAIJ(), MatSetValues()
1437 @*/
1438 int MatCreateMPIAIJ(MPI_Comm comm,int m,int n,int M,int N,
1439                     int d_nz,int *d_nnz,int o_nz,int *o_nnz,Mat *newmat)
1440 {
1441   Mat          mat;
1442   Mat_MPIAIJ   *a;
1443   int          ierr, i,sum[2],work[2];
1444 
1445   *newmat         = 0;
1446   PetscHeaderCreate(mat,_Mat,MAT_COOKIE,MATMPIAIJ,comm);
1447   PLogObjectCreate(mat);
1448   mat->data       = (void *) (a = PetscNew(Mat_MPIAIJ)); CHKPTRQ(a);
1449   PetscMemcpy(&mat->ops,&MatOps,sizeof(struct _MatOps));
1450   mat->destroy    = MatDestroy_MPIAIJ;
1451   mat->view       = MatView_MPIAIJ;
1452   mat->factor     = 0;
1453   mat->assembled  = PETSC_FALSE;
1454 
1455   a->insertmode = NOT_SET_VALUES;
1456   MPI_Comm_rank(comm,&a->rank);
1457   MPI_Comm_size(comm,&a->size);
1458 
1459   if (m == PETSC_DECIDE && (d_nnz != PETSC_NULL || o_nnz != PETSC_NULL))
1460     SETERRQ(1,"MatCreateMPIAIJ:Cannot have PETSc decide rows but set d_nnz or o_nnz");
1461 
1462   if (M == PETSC_DECIDE || N == PETSC_DECIDE) {
1463     work[0] = m; work[1] = n;
1464     MPI_Allreduce( work, sum,2,MPI_INT,MPI_SUM,comm );
1465     if (M == PETSC_DECIDE) M = sum[0];
1466     if (N == PETSC_DECIDE) N = sum[1];
1467   }
1468   if (m == PETSC_DECIDE) {m = M/a->size + ((M % a->size) > a->rank);}
1469   if (n == PETSC_DECIDE) {n = N/a->size + ((N % a->size) > a->rank);}
1470   a->m = m;
1471   a->n = n;
1472   a->N = N;
1473   a->M = M;
1474 
1475   /* build local table of row and column ownerships */
1476   a->rowners = (int *) PetscMalloc(2*(a->size+2)*sizeof(int)); CHKPTRQ(a->rowners);
1477   PLogObjectMemory(mat,2*(a->size+2)*sizeof(int)+sizeof(struct _Mat)+sizeof(Mat_MPIAIJ));
1478   a->cowners = a->rowners + a->size + 1;
1479   MPI_Allgather(&m,1,MPI_INT,a->rowners+1,1,MPI_INT,comm);
1480   a->rowners[0] = 0;
1481   for ( i=2; i<=a->size; i++ ) {
1482     a->rowners[i] += a->rowners[i-1];
1483   }
1484   a->rstart = a->rowners[a->rank];
1485   a->rend   = a->rowners[a->rank+1];
1486   MPI_Allgather(&n,1,MPI_INT,a->cowners+1,1,MPI_INT,comm);
1487   a->cowners[0] = 0;
1488   for ( i=2; i<=a->size; i++ ) {
1489     a->cowners[i] += a->cowners[i-1];
1490   }
1491   a->cstart = a->cowners[a->rank];
1492   a->cend   = a->cowners[a->rank+1];
1493 
1494   if (d_nz == PETSC_DEFAULT) d_nz = 5;
1495   ierr = MatCreateSeqAIJ(MPI_COMM_SELF,m,n,d_nz,d_nnz,&a->A); CHKERRQ(ierr);
1496   PLogObjectParent(mat,a->A);
1497   if (o_nz == PETSC_DEFAULT) o_nz = 0;
1498   ierr = MatCreateSeqAIJ(MPI_COMM_SELF,m,N,o_nz,o_nnz,&a->B); CHKERRQ(ierr);
1499   PLogObjectParent(mat,a->B);
1500 
1501   /* build cache for off array entries formed */
1502   ierr = StashBuild_Private(&a->stash); CHKERRQ(ierr);
1503   a->colmap      = 0;
1504   a->garray      = 0;
1505   a->roworiented = 1;
1506 
1507   /* stuff used for matrix vector multiply */
1508   a->lvec      = 0;
1509   a->Mvctx     = 0;
1510 
1511   /* stuff for MatGetRow() */
1512   a->rowindices   = 0;
1513   a->rowvalues    = 0;
1514   a->getrowactive = PETSC_FALSE;
1515 
1516   *newmat = mat;
1517   return 0;
1518 }
1519 
1520 static int MatConvertSameType_MPIAIJ(Mat matin,Mat *newmat,int cpvalues)
1521 {
1522   Mat        mat;
1523   Mat_MPIAIJ *a,*oldmat = (Mat_MPIAIJ *) matin->data;
1524   int        ierr, len,flg;
1525 
1526   *newmat       = 0;
1527   PetscHeaderCreate(mat,_Mat,MAT_COOKIE,MATMPIAIJ,matin->comm);
1528   PLogObjectCreate(mat);
1529   mat->data       = (void *) (a = PetscNew(Mat_MPIAIJ)); CHKPTRQ(a);
1530   PetscMemcpy(&mat->ops,&MatOps,sizeof(struct _MatOps));
1531   mat->destroy    = MatDestroy_MPIAIJ;
1532   mat->view       = MatView_MPIAIJ;
1533   mat->factor     = matin->factor;
1534   mat->assembled  = PETSC_TRUE;
1535 
1536   a->m          = oldmat->m;
1537   a->n          = oldmat->n;
1538   a->M          = oldmat->M;
1539   a->N          = oldmat->N;
1540 
1541   a->rstart     = oldmat->rstart;
1542   a->rend       = oldmat->rend;
1543   a->cstart     = oldmat->cstart;
1544   a->cend       = oldmat->cend;
1545   a->size       = oldmat->size;
1546   a->rank       = oldmat->rank;
1547   a->insertmode = NOT_SET_VALUES;
1548 
1549   a->rowners = (int *) PetscMalloc((a->size+1)*sizeof(int)); CHKPTRQ(a->rowners);
1550   PLogObjectMemory(mat,(a->size+1)*sizeof(int)+sizeof(struct _Mat)+sizeof(Mat_MPIAIJ));
1551   PetscMemcpy(a->rowners,oldmat->rowners,(a->size+1)*sizeof(int));
1552   ierr = StashInitialize_Private(&a->stash); CHKERRQ(ierr);
1553   if (oldmat->colmap) {
1554     a->colmap = (int *) PetscMalloc((a->N)*sizeof(int));CHKPTRQ(a->colmap);
1555     PLogObjectMemory(mat,(a->N)*sizeof(int));
1556     PetscMemcpy(a->colmap,oldmat->colmap,(a->N)*sizeof(int));
1557   } else a->colmap = 0;
1558   if (oldmat->garray && (len = ((Mat_SeqAIJ *) (oldmat->B->data))->n)) {
1559     a->garray = (int *) PetscMalloc(len*sizeof(int)); CHKPTRQ(a->garray);
1560     PLogObjectMemory(mat,len*sizeof(int));
1561     PetscMemcpy(a->garray,oldmat->garray,len*sizeof(int));
1562   } else a->garray = 0;
1563 
1564   ierr =  VecDuplicate(oldmat->lvec,&a->lvec); CHKERRQ(ierr);
1565   PLogObjectParent(mat,a->lvec);
1566   ierr =  VecScatterCopy(oldmat->Mvctx,&a->Mvctx); CHKERRQ(ierr);
1567   PLogObjectParent(mat,a->Mvctx);
1568   ierr =  MatConvert(oldmat->A,MATSAME,&a->A); CHKERRQ(ierr);
1569   PLogObjectParent(mat,a->A);
1570   ierr =  MatConvert(oldmat->B,MATSAME,&a->B); CHKERRQ(ierr);
1571   PLogObjectParent(mat,a->B);
1572   ierr = OptionsHasName(PETSC_NULL,"-help",&flg); CHKERRQ(ierr);
1573   if (flg) {
1574     ierr = MatPrintHelp(mat); CHKERRQ(ierr);
1575   }
1576   *newmat = mat;
1577   return 0;
1578 }
1579 
1580 #include "sysio.h"
1581 
1582 int MatLoad_MPIAIJ(Viewer bview,MatType type,Mat *newmat)
1583 {
1584   Mat          A;
1585   int          i, nz, ierr, j,rstart, rend, fd;
1586   Scalar       *vals,*svals;
1587   PetscObject  vobj = (PetscObject) bview;
1588   MPI_Comm     comm = vobj->comm;
1589   MPI_Status   status;
1590   int          header[4],rank,size,*rowlengths = 0,M,N,m,*rowners,maxnz,*cols;
1591   int          *ourlens,*sndcounts = 0,*procsnz = 0, *offlens,jj,*mycols,*smycols;
1592   int          tag = ((PetscObject)bview)->tag;
1593 
1594   MPI_Comm_size(comm,&size); MPI_Comm_rank(comm,&rank);
1595   if (!rank) {
1596     ierr = ViewerFileGetDescriptor_Private(bview,&fd); CHKERRQ(ierr);
1597     ierr = SYRead(fd,(char *)header,4,SYINT); CHKERRQ(ierr);
1598     if (header[0] != MAT_COOKIE) SETERRQ(1,"MatLoad_MPIAIJ:not matrix object");
1599   }
1600 
1601   MPI_Bcast(header+1,3,MPI_INT,0,comm);
1602   M = header[1]; N = header[2];
1603   /* determine ownership of all rows */
1604   m = M/size + ((M % size) > rank);
1605   rowners = (int *) PetscMalloc((size+2)*sizeof(int)); CHKPTRQ(rowners);
1606   MPI_Allgather(&m,1,MPI_INT,rowners+1,1,MPI_INT,comm);
1607   rowners[0] = 0;
1608   for ( i=2; i<=size; i++ ) {
1609     rowners[i] += rowners[i-1];
1610   }
1611   rstart = rowners[rank];
1612   rend   = rowners[rank+1];
1613 
1614   /* distribute row lengths to all processors */
1615   ourlens = (int*) PetscMalloc( 2*(rend-rstart)*sizeof(int) ); CHKPTRQ(ourlens);
1616   offlens = ourlens + (rend-rstart);
1617   if (!rank) {
1618     rowlengths = (int*) PetscMalloc( M*sizeof(int) ); CHKPTRQ(rowlengths);
1619     ierr = SYRead(fd,rowlengths,M,SYINT); CHKERRQ(ierr);
1620     sndcounts = (int*) PetscMalloc( size*sizeof(int) ); CHKPTRQ(sndcounts);
1621     for ( i=0; i<size; i++ ) sndcounts[i] = rowners[i+1] - rowners[i];
1622     MPI_Scatterv(rowlengths,sndcounts,rowners,MPI_INT,ourlens,rend-rstart,MPI_INT,0,comm);
1623     PetscFree(sndcounts);
1624   }
1625   else {
1626     MPI_Scatterv(0,0,0,MPI_INT,ourlens,rend-rstart,MPI_INT, 0,comm);
1627   }
1628 
1629   if (!rank) {
1630     /* calculate the number of nonzeros on each processor */
1631     procsnz = (int*) PetscMalloc( size*sizeof(int) ); CHKPTRQ(procsnz);
1632     PetscMemzero(procsnz,size*sizeof(int));
1633     for ( i=0; i<size; i++ ) {
1634       for ( j=rowners[i]; j< rowners[i+1]; j++ ) {
1635         procsnz[i] += rowlengths[j];
1636       }
1637     }
1638     PetscFree(rowlengths);
1639 
1640     /* determine max buffer needed and allocate it */
1641     maxnz = 0;
1642     for ( i=0; i<size; i++ ) {
1643       maxnz = PetscMax(maxnz,procsnz[i]);
1644     }
1645     cols = (int *) PetscMalloc( maxnz*sizeof(int) ); CHKPTRQ(cols);
1646 
1647     /* read in my part of the matrix column indices  */
1648     nz = procsnz[0];
1649     mycols = (int *) PetscMalloc( nz*sizeof(int) ); CHKPTRQ(mycols);
1650     ierr = SYRead(fd,mycols,nz,SYINT); CHKERRQ(ierr);
1651 
1652     /* read in every one elses and ship off */
1653     for ( i=1; i<size; i++ ) {
1654       nz = procsnz[i];
1655       ierr = SYRead(fd,cols,nz,SYINT); CHKERRQ(ierr);
1656       MPI_Send(cols,nz,MPI_INT,i,tag,comm);
1657     }
1658     PetscFree(cols);
1659   }
1660   else {
1661     /* determine buffer space needed for message */
1662     nz = 0;
1663     for ( i=0; i<m; i++ ) {
1664       nz += ourlens[i];
1665     }
1666     mycols = (int*) PetscMalloc( nz*sizeof(int) ); CHKPTRQ(mycols);
1667 
1668     /* receive message of column indices*/
1669     MPI_Recv(mycols,nz,MPI_INT,0,tag,comm,&status);
1670     MPI_Get_count(&status,MPI_INT,&maxnz);
1671     if (maxnz != nz) SETERRQ(1,"MatLoad_MPIAIJ:something is wrong with file");
1672   }
1673 
1674   /* loop over local rows, determining number of off diagonal entries */
1675   PetscMemzero(offlens,m*sizeof(int));
1676   jj = 0;
1677   for ( i=0; i<m; i++ ) {
1678     for ( j=0; j<ourlens[i]; j++ ) {
1679       if (mycols[jj] < rstart || mycols[jj] >= rend) offlens[i]++;
1680       jj++;
1681     }
1682   }
1683 
1684   /* create our matrix */
1685   for ( i=0; i<m; i++ ) {
1686     ourlens[i] -= offlens[i];
1687   }
1688   ierr = MatCreateMPIAIJ(comm,m,PETSC_DECIDE,M,N,0,ourlens,0,offlens,newmat);CHKERRQ(ierr);
1689   A = *newmat;
1690   MatSetOption(A,COLUMNS_SORTED);
1691   for ( i=0; i<m; i++ ) {
1692     ourlens[i] += offlens[i];
1693   }
1694 
1695   if (!rank) {
1696     vals = (Scalar *) PetscMalloc( maxnz*sizeof(Scalar) ); CHKPTRQ(vals);
1697 
1698     /* read in my part of the matrix numerical values  */
1699     nz = procsnz[0];
1700     ierr = SYRead(fd,vals,nz,SYSCALAR); CHKERRQ(ierr);
1701 
1702     /* insert into matrix */
1703     jj      = rstart;
1704     smycols = mycols;
1705     svals   = vals;
1706     for ( i=0; i<m; i++ ) {
1707       ierr = MatSetValues(A,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
1708       smycols += ourlens[i];
1709       svals   += ourlens[i];
1710       jj++;
1711     }
1712 
1713     /* read in other processors and ship out */
1714     for ( i=1; i<size; i++ ) {
1715       nz = procsnz[i];
1716       ierr = SYRead(fd,vals,nz,SYSCALAR); CHKERRQ(ierr);
1717       MPI_Send(vals,nz,MPIU_SCALAR,i,A->tag,comm);
1718     }
1719     PetscFree(procsnz);
1720   }
1721   else {
1722     /* receive numeric values */
1723     vals = (Scalar*) PetscMalloc( nz*sizeof(Scalar) ); CHKPTRQ(vals);
1724 
1725     /* receive message of values*/
1726     MPI_Recv(vals,nz,MPIU_SCALAR,0,A->tag,comm,&status);
1727     MPI_Get_count(&status,MPIU_SCALAR,&maxnz);
1728     if (maxnz != nz) SETERRQ(1,"MatLoad_MPIAIJ:something is wrong with file");
1729 
1730     /* insert into matrix */
1731     jj      = rstart;
1732     smycols = mycols;
1733     svals   = vals;
1734     for ( i=0; i<m; i++ ) {
1735       ierr = MatSetValues(A,1,&jj,ourlens[i],smycols,svals,INSERT_VALUES);CHKERRQ(ierr);
1736       smycols += ourlens[i];
1737       svals   += ourlens[i];
1738       jj++;
1739     }
1740   }
1741   PetscFree(ourlens); PetscFree(vals); PetscFree(mycols); PetscFree(rowners);
1742 
1743   ierr = MatAssemblyBegin(A,FINAL_ASSEMBLY); CHKERRQ(ierr);
1744   ierr = MatAssemblyEnd(A,FINAL_ASSEMBLY); CHKERRQ(ierr);
1745   return 0;
1746 }
1747