xref: /petsc/src/mat/impls/baij/seq/baijfact3.c (revision c07bf0741b2e8ac3bb29c3d024f5883d65444abc)
1 #define PETSCMAT_DLL
2 
3 /*
4     Factorization code for BAIJ format.
5 */
6 #include "../src/mat/impls/baij/seq/baij.h"
7 #include "../src/mat/blockinvert.h"
8 
9 #undef __FUNCT__
10 #define __FUNCT__ "MatSeqBAIJSetNumericFactorization"
11 /*
12    This is used to set the numeric factorization for both LU and ILU symbolic factorization
13 */
14 PetscErrorCode MatSeqBAIJSetNumericFactorization(Mat fact,PetscTruth natural)
15 {
16   PetscFunctionBegin;
17   if(natural){
18     switch (fact->rmap->bs){
19     case 2:
20       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering;
21       break;
22     case 3:
23       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering;
24       break;
25     case 4:
26       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering;
27       break;
28     case 5:
29       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_NaturalOrdering;
30       break;
31     case 6:
32       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6_NaturalOrdering;
33       break;
34     case 7:
35       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7_NaturalOrdering;
36       break;
37     default:
38       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N;
39       break;
40     }
41   }
42   else{
43     switch (fact->rmap->bs){
44     case 2:
45       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2;
46       break;
47     case 3:
48       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3;
49       break;
50     case 4:
51       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4;
52       break;
53     case 5:
54       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5;
55       break;
56     case 6:
57       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6;
58       break;
59     case 7:
60       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7;
61       break;
62     default:
63       fact->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N;
64       break;
65     }
66   }
67   PetscFunctionReturn(0);
68 }
69 
70 PetscErrorCode MatSeqBAIJSetNumericFactorization_inplace(Mat inA,PetscTruth natural)
71 {
72   PetscFunctionBegin;
73   if (natural) {
74     switch (inA->rmap->bs) {
75     case 1:
76       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_1_inplace;
77       break;
78     case 2:
79       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering_inplace;
80       break;
81     case 3:
82       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering_inplace;
83       break;
84     case 4:
85 #if defined(PETSC_USE_SCALAR_MAT_SINGLE)
86       {
87         PetscTruth  sse_enabled_local;
88         PetscErrorCode ierr;
89         ierr = PetscSSEIsEnabled(inA->comm,&sse_enabled_local,PETSC_NULL);CHKERRQ(ierr);
90         if (sse_enabled_local) {
91 #  if defined(PETSC_HAVE_SSE)
92           int i,*AJ=a->j,nz=a->nz,n=a->mbs;
93           if (n==(unsigned short)n) {
94             unsigned short *aj=(unsigned short *)AJ;
95             for (i=0;i<nz;i++) {
96               aj[i] = (unsigned short)AJ[i];
97             }
98             inA->ops->setunfactored   = MatSetUnfactored_SeqBAIJ_4_NaturalOrdering_SSE_usj;
99             inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_SSE_usj;
100             ierr = PetscInfo(inA,"Using special SSE, in-place natural ordering, ushort j index factor BS=4\n");CHKERRQ(ierr);
101           } else {
102         /* Scale the column indices for easier indexing in MatSolve. */
103 /*            for (i=0;i<nz;i++) { */
104 /*              AJ[i] = AJ[i]*4; */
105 /*            } */
106             inA->ops->setunfactored   = MatSetUnfactored_SeqBAIJ_4_NaturalOrdering_SSE;
107             inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_SSE;
108             ierr = PetscInfo(inA,"Using special SSE, in-place natural ordering, int j index factor BS=4\n");CHKERRQ(ierr);
109           }
110 #  else
111         /* This should never be reached.  If so, problem in PetscSSEIsEnabled. */
112           SETERRQ(PETSC_ERR_SUP,"SSE Hardware unavailable");
113 #  endif
114         } else {
115           inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_inplace;
116         }
117       }
118 #else
119       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering_inplace;
120 #endif
121       break;
122     case 5:
123       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_NaturalOrdering_inplace;
124       break;
125     case 6:
126       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6_NaturalOrdering_inplace;
127       break;
128     case 7:
129       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7_NaturalOrdering_inplace;
130       break;
131     default:
132       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N_inplace;
133       break;
134     }
135   } else {
136     switch (inA->rmap->bs) {
137     case 1:
138       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_1_inplace;
139       break;
140     case 2:
141       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_2_inplace;
142       break;
143     case 3:
144       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_3_inplace;
145       break;
146     case 4:
147       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_inplace;
148       break;
149     case 5:
150       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_inplace;
151       break;
152     case 6:
153       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_6_inplace;
154       break;
155     case 7:
156       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_7_inplace;
157       break;
158     default:
159       inA->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_N_inplace;
160       break;
161     }
162   }
163   PetscFunctionReturn(0);
164 }
165 
166 /*
167     The symbolic factorization code is identical to that for AIJ format,
168   except for very small changes since this is now a SeqBAIJ datastructure.
169   NOT good code reuse.
170 */
171 #include "petscbt.h"
172 #include "../src/mat/utils/freespace.h"
173 
174 #undef __FUNCT__
175 #define __FUNCT__ "MatLUFactorSymbolic_SeqBAIJ"
176 PetscErrorCode MatLUFactorSymbolic_SeqBAIJ(Mat B,Mat A,IS isrow,IS iscol,const MatFactorInfo *info)
177 {
178   Mat_SeqBAIJ        *a = (Mat_SeqBAIJ*)A->data,*b;
179   PetscInt           n=a->mbs,bs = A->rmap->bs,bs2=a->bs2;
180   PetscTruth         row_identity,col_identity,both_identity;
181   IS                 isicol;
182   PetscErrorCode     ierr;
183   const PetscInt     *r,*ic;
184   PetscInt           i,*ai=a->i,*aj=a->j;
185   PetscInt           *bi,*bj,*ajtmp;
186   PetscInt           *bdiag,row,nnz,nzi,reallocs=0,nzbd,*im;
187   PetscReal          f;
188   PetscInt           nlnk,*lnk,k,**bi_ptr;
189   PetscFreeSpaceList free_space=PETSC_NULL,current_space=PETSC_NULL;
190   PetscBT            lnkbt;
191   PetscTruth         newdatastruct=PETSC_FALSE;
192 
193   PetscFunctionBegin;
194   ierr = PetscOptionsGetTruth(PETSC_NULL,"-lu_old",&newdatastruct,PETSC_NULL);CHKERRQ(ierr);
195   if(newdatastruct){
196     ierr = MatLUFactorSymbolic_SeqBAIJ_inplace(B,A,isrow,iscol,info);CHKERRQ(ierr);
197     PetscFunctionReturn(0);
198   }
199   if (A->rmap->N != A->cmap->N) SETERRQ(PETSC_ERR_ARG_WRONG,"matrix must be square");
200   ierr = ISInvertPermutation(iscol,PETSC_DECIDE,&isicol);CHKERRQ(ierr);
201   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
202   ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr);
203 
204   /* get new row and diagonal pointers, must be allocated separately because they will be given to the Mat_SeqAIJ and freed separately */
205   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
206   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bdiag);CHKERRQ(ierr);
207   bi[0] = bdiag[0] = 0;
208 
209   /* linked list for storing column indices of the active row */
210   nlnk = n + 1;
211   ierr = PetscLLCreate(n,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
212 
213   ierr = PetscMalloc2(n+1,PetscInt**,&bi_ptr,n+1,PetscInt,&im);CHKERRQ(ierr);
214 
215   /* initial FreeSpace size is f*(ai[n]+1) */
216   f = info->fill;
217   ierr = PetscFreeSpaceGet((PetscInt)(f*(ai[n]+1)),&free_space);CHKERRQ(ierr);
218   current_space = free_space;
219 
220   for (i=0; i<n; i++) {
221     /* copy previous fill into linked list */
222     nzi = 0;
223     nnz = ai[r[i]+1] - ai[r[i]];
224     if (!nnz) SETERRQ2(PETSC_ERR_MAT_LU_ZRPVT,"Empty row in matrix: row in original ordering %D in permuted ordering %D",r[i],i);
225     ajtmp = aj + ai[r[i]];
226     ierr = PetscLLAddPerm(nnz,ajtmp,ic,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
227     nzi += nlnk;
228 
229     /* add pivot rows into linked list */
230     row = lnk[n];
231     while (row < i) {
232       nzbd    = bdiag[row] + 1; /* num of entries in the row with column index <= row */
233       ajtmp   = bi_ptr[row] + nzbd; /* points to the entry next to the diagonal */
234       ierr = PetscLLAddSortedLU(ajtmp,row,nlnk,lnk,lnkbt,i,nzbd,im);CHKERRQ(ierr);
235       nzi += nlnk;
236       row  = lnk[row];
237     }
238     bi[i+1] = bi[i] + nzi;
239     im[i]   = nzi;
240 
241     /* mark bdiag */
242     nzbd = 0;
243     nnz  = nzi;
244     k    = lnk[n];
245     while (nnz-- && k < i){
246       nzbd++;
247       k = lnk[k];
248     }
249     bdiag[i] = nzbd; /* note : bdaig[i] = nnzL as input for PetscFreeSpaceContiguous_LU() */
250 
251     /* if free space is not available, make more free space */
252     if (current_space->local_remaining<nzi) {
253       nnz = 2*(n - i)*nzi; /* estimated and max additional space needed */
254       ierr = PetscFreeSpaceGet(nnz,&current_space);CHKERRQ(ierr);
255       reallocs++;
256     }
257 
258     /* copy data into free space, then initialize lnk */
259     ierr = PetscLLClean(n,n,nzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
260     bi_ptr[i] = current_space->array;
261     current_space->array           += nzi;
262     current_space->local_used      += nzi;
263     current_space->local_remaining -= nzi;
264   }
265 #if defined(PETSC_USE_INFO)
266   if (ai[n] != 0) {
267     PetscReal af = ((PetscReal)bi[n])/((PetscReal)ai[n]);
268     ierr = PetscInfo3(A,"Reallocs %D Fill ratio:given %G needed %G\n",reallocs,f,af);CHKERRQ(ierr);
269     ierr = PetscInfo1(A,"Run with -pc_factor_fill %G or use \n",af);CHKERRQ(ierr);
270     ierr = PetscInfo1(A,"PCFactorSetFill(pc,%G);\n",af);CHKERRQ(ierr);
271     ierr = PetscInfo(A,"for best performance.\n");CHKERRQ(ierr);
272   } else {
273     ierr = PetscInfo(A,"Empty matrix\n");CHKERRQ(ierr);
274   }
275 #endif
276 
277   ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr);
278   ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr);
279 
280   /* destroy list of free space and other temporary array(s) */
281   ierr = PetscMalloc((bi[n]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
282   ierr = PetscFreeSpaceContiguous_LU(&free_space,bj,n,bi,bdiag);CHKERRQ(ierr);
283   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
284   ierr = PetscFree2(bi_ptr,im);CHKERRQ(ierr);
285 
286   /* put together the new matrix */
287   ierr = MatSeqBAIJSetPreallocation_SeqBAIJ(B,bs,MAT_SKIP_ALLOCATION,PETSC_NULL);CHKERRQ(ierr);
288   ierr = PetscLogObjectParent(B,isicol);CHKERRQ(ierr);
289   b    = (Mat_SeqBAIJ*)(B)->data;
290   b->free_a       = PETSC_TRUE;
291   b->free_ij      = PETSC_TRUE;
292   b->singlemalloc = PETSC_FALSE;
293   ierr          = PetscMalloc((bdiag[0]+1)*sizeof(MatScalar)*bs2,&b->a);CHKERRQ(ierr);
294   b->j          = bj;
295   b->i          = bi;
296   b->diag       = bdiag;
297   b->free_diag  = PETSC_TRUE;
298   b->ilen       = 0;
299   b->imax       = 0;
300   b->row        = isrow;
301   b->col        = iscol;
302   b->pivotinblocks = (info->pivotinblocks) ? PETSC_TRUE : PETSC_FALSE;
303   ierr          = PetscObjectReference((PetscObject)isrow);CHKERRQ(ierr);
304   ierr          = PetscObjectReference((PetscObject)iscol);CHKERRQ(ierr);
305   b->icol       = isicol;
306   ierr = PetscMalloc((bs*n+bs)*sizeof(PetscScalar),&b->solve_work);CHKERRQ(ierr);
307   ierr = PetscLogObjectMemory(B,(bdiag[0]+1)*(sizeof(PetscInt)+sizeof(PetscScalar)*bs2));CHKERRQ(ierr);
308 
309   b->maxnz = b->nz = bdiag[0]+1;
310   B->factor                =  MAT_FACTOR_LU;
311   B->info.factor_mallocs   = reallocs;
312   B->info.fill_ratio_given = f;
313 
314   if (ai[n] != 0) {
315     B->info.fill_ratio_needed = ((PetscReal)(bdiag[0]+1))/((PetscReal)ai[n]);
316   } else {
317     B->info.fill_ratio_needed = 0.0;
318   }
319 
320   ierr = ISIdentity(isrow,&row_identity);CHKERRQ(ierr);
321   ierr = ISIdentity(iscol,&col_identity);CHKERRQ(ierr);
322   both_identity = (PetscTruth) (row_identity && col_identity);
323   ierr = MatSeqBAIJSetNumericFactorization(B,both_identity);CHKERRQ(ierr);
324   PetscFunctionReturn(0);
325  }
326 
327 #undef __FUNCT__
328 #define __FUNCT__ "MatLUFactorSymbolic_SeqBAIJ_inplace"
329 PetscErrorCode MatLUFactorSymbolic_SeqBAIJ_inplace(Mat B,Mat A,IS isrow,IS iscol,const MatFactorInfo *info)
330 {
331   Mat_SeqBAIJ        *a = (Mat_SeqBAIJ*)A->data,*b;
332   PetscInt           n=a->mbs,bs = A->rmap->bs,bs2=a->bs2;
333   PetscTruth         row_identity,col_identity,both_identity;
334   IS                 isicol;
335   PetscErrorCode     ierr;
336   const PetscInt     *r,*ic;
337   PetscInt           i,*ai=a->i,*aj=a->j;
338   PetscInt           *bi,*bj,*ajtmp;
339   PetscInt           *bdiag,row,nnz,nzi,reallocs=0,nzbd,*im;
340   PetscReal          f;
341   PetscInt           nlnk,*lnk,k,**bi_ptr;
342   PetscFreeSpaceList free_space=PETSC_NULL,current_space=PETSC_NULL;
343   PetscBT            lnkbt;
344 
345   PetscFunctionBegin;
346   if (A->rmap->N != A->cmap->N) SETERRQ(PETSC_ERR_ARG_WRONG,"matrix must be square");
347   ierr = ISInvertPermutation(iscol,PETSC_DECIDE,&isicol);CHKERRQ(ierr);
348   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
349   ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr);
350 
351   /* get new row and diagonal pointers, must be allocated separately because they will be given to the Mat_SeqAIJ and freed separately */
352   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bi);CHKERRQ(ierr);
353   ierr = PetscMalloc((n+1)*sizeof(PetscInt),&bdiag);CHKERRQ(ierr);
354 
355   bi[0] = bdiag[0] = 0;
356 
357   /* linked list for storing column indices of the active row */
358   nlnk = n + 1;
359   ierr = PetscLLCreate(n,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
360 
361   ierr = PetscMalloc2(n+1,PetscInt**,&bi_ptr,n+1,PetscInt,&im);CHKERRQ(ierr);
362 
363   /* initial FreeSpace size is f*(ai[n]+1) */
364   f = info->fill;
365   ierr = PetscFreeSpaceGet((PetscInt)(f*(ai[n]+1)),&free_space);CHKERRQ(ierr);
366   current_space = free_space;
367 
368   for (i=0; i<n; i++) {
369     /* copy previous fill into linked list */
370     nzi = 0;
371     nnz = ai[r[i]+1] - ai[r[i]];
372     if (!nnz) SETERRQ2(PETSC_ERR_MAT_LU_ZRPVT,"Empty row in matrix: row in original ordering %D in permuted ordering %D",r[i],i);
373     ajtmp = aj + ai[r[i]];
374     ierr = PetscLLAddPerm(nnz,ajtmp,ic,n,nlnk,lnk,lnkbt);CHKERRQ(ierr);
375     nzi += nlnk;
376 
377     /* add pivot rows into linked list */
378     row = lnk[n];
379     while (row < i) {
380       nzbd    = bdiag[row] - bi[row] + 1; /* num of entries in the row with column index <= row */
381       ajtmp   = bi_ptr[row] + nzbd; /* points to the entry next to the diagonal */
382       ierr = PetscLLAddSortedLU(ajtmp,row,nlnk,lnk,lnkbt,i,nzbd,im);CHKERRQ(ierr);
383       nzi += nlnk;
384       row  = lnk[row];
385     }
386     bi[i+1] = bi[i] + nzi;
387     im[i]   = nzi;
388 
389     /* mark bdiag */
390     nzbd = 0;
391     nnz  = nzi;
392     k    = lnk[n];
393     while (nnz-- && k < i){
394       nzbd++;
395       k = lnk[k];
396     }
397     bdiag[i] = bi[i] + nzbd;
398 
399     /* if free space is not available, make more free space */
400     if (current_space->local_remaining<nzi) {
401       nnz = (n - i)*nzi; /* estimated and max additional space needed */
402       ierr = PetscFreeSpaceGet(nnz,&current_space);CHKERRQ(ierr);
403       reallocs++;
404     }
405 
406     /* copy data into free space, then initialize lnk */
407     ierr = PetscLLClean(n,n,nzi,lnk,current_space->array,lnkbt);CHKERRQ(ierr);
408     bi_ptr[i] = current_space->array;
409     current_space->array           += nzi;
410     current_space->local_used      += nzi;
411     current_space->local_remaining -= nzi;
412   }
413 #if defined(PETSC_USE_INFO)
414   if (ai[n] != 0) {
415     PetscReal af = ((PetscReal)bi[n])/((PetscReal)ai[n]);
416     ierr = PetscInfo3(A,"Reallocs %D Fill ratio:given %G needed %G\n",reallocs,f,af);CHKERRQ(ierr);
417     ierr = PetscInfo1(A,"Run with -pc_factor_fill %G or use \n",af);CHKERRQ(ierr);
418     ierr = PetscInfo1(A,"PCFactorSetFill(pc,%G);\n",af);CHKERRQ(ierr);
419     ierr = PetscInfo(A,"for best performance.\n");CHKERRQ(ierr);
420   } else {
421     ierr = PetscInfo(A,"Empty matrix\n");CHKERRQ(ierr);
422   }
423 #endif
424 
425   ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr);
426   ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr);
427 
428   /* destroy list of free space and other temporary array(s) */
429   ierr = PetscMalloc((bi[n]+1)*sizeof(PetscInt),&bj);CHKERRQ(ierr);
430   ierr = PetscFreeSpaceContiguous(&free_space,bj);CHKERRQ(ierr);
431   ierr = PetscLLDestroy(lnk,lnkbt);CHKERRQ(ierr);
432   ierr = PetscFree2(bi_ptr,im);CHKERRQ(ierr);
433 
434   /* put together the new matrix */
435   ierr = MatSeqBAIJSetPreallocation_SeqBAIJ(B,bs,MAT_SKIP_ALLOCATION,PETSC_NULL);CHKERRQ(ierr);
436   ierr = PetscLogObjectParent(B,isicol);CHKERRQ(ierr);
437   b    = (Mat_SeqBAIJ*)(B)->data;
438   b->free_a       = PETSC_TRUE;
439   b->free_ij      = PETSC_TRUE;
440   b->singlemalloc = PETSC_FALSE;
441   ierr          = PetscMalloc((bi[n]+1)*sizeof(MatScalar)*bs2,&b->a);CHKERRQ(ierr);
442   b->j          = bj;
443   b->i          = bi;
444   b->diag       = bdiag;
445   b->free_diag  = PETSC_TRUE;
446   b->ilen       = 0;
447   b->imax       = 0;
448   b->row        = isrow;
449   b->col        = iscol;
450   b->pivotinblocks = (info->pivotinblocks) ? PETSC_TRUE : PETSC_FALSE;
451   ierr          = PetscObjectReference((PetscObject)isrow);CHKERRQ(ierr);
452   ierr          = PetscObjectReference((PetscObject)iscol);CHKERRQ(ierr);
453   b->icol       = isicol;
454   ierr = PetscMalloc((bs*n+bs)*sizeof(PetscScalar),&b->solve_work);CHKERRQ(ierr);
455   ierr = PetscLogObjectMemory(B,(bi[n]-n)*(sizeof(PetscInt)+sizeof(PetscScalar)*bs2));CHKERRQ(ierr);
456 
457   b->maxnz = b->nz = bi[n] ;
458   (B)->factor                =  MAT_FACTOR_LU;
459   (B)->info.factor_mallocs   = reallocs;
460   (B)->info.fill_ratio_given = f;
461 
462   if (ai[n] != 0) {
463     (B)->info.fill_ratio_needed = ((PetscReal)bi[n])/((PetscReal)ai[n]);
464   } else {
465     (B)->info.fill_ratio_needed = 0.0;
466   }
467 
468   ierr = ISIdentity(isrow,&row_identity);CHKERRQ(ierr);
469   ierr = ISIdentity(iscol,&col_identity);CHKERRQ(ierr);
470   both_identity = (PetscTruth) (row_identity && col_identity);
471   ierr = MatSeqBAIJSetNumericFactorization_inplace(B,both_identity);CHKERRQ(ierr);
472   PetscFunctionReturn(0);
473  }
474 
475