Actual source code: baijfact.c

petsc-3.6.1 2015-08-06
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  2: /*
  3:     Factorization code for BAIJ format.
  4: */
  5: #include <../src/mat/impls/baij/seq/baij.h>
  6: #include <petsc/private/kernels/blockinvert.h>

 10: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_2(Mat B,Mat A,const MatFactorInfo *info)
 11: {
 12:   Mat            C     =B;
 13:   Mat_SeqBAIJ    *a    =(Mat_SeqBAIJ*)A->data,*b=(Mat_SeqBAIJ*)C->data;
 14:   IS             isrow = b->row,isicol = b->icol;
 16:   const PetscInt *r,*ic;
 17:   PetscInt       i,j,k,nz,nzL,row,*pj;
 18:   const PetscInt n=a->mbs,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,bs2=a->bs2;
 19:   const PetscInt *ajtmp,*bjtmp,*bdiag=b->diag;
 20:   MatScalar      *rtmp,*pc,*mwork,*pv;
 21:   MatScalar      *aa=a->a,*v;
 22:   PetscInt       flg;
 23:   PetscReal      shift = info->shiftamount;

 26:   ISGetIndices(isrow,&r);
 27:   ISGetIndices(isicol,&ic);

 29:   /* generate work space needed by the factorization */
 30:   PetscMalloc2(bs2*n,&rtmp,bs2,&mwork);
 31:   PetscMemzero(rtmp,bs2*n*sizeof(MatScalar));

 33:   for (i=0; i<n; i++) {
 34:     /* zero rtmp */
 35:     /* L part */
 36:     nz    = bi[i+1] - bi[i];
 37:     bjtmp = bj + bi[i];
 38:     for  (j=0; j<nz; j++) {
 39:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
 40:     }

 42:     /* U part */
 43:     nz    = bdiag[i] - bdiag[i+1];
 44:     bjtmp = bj + bdiag[i+1]+1;
 45:     for  (j=0; j<nz; j++) {
 46:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
 47:     }

 49:     /* load in initial (unfactored row) */
 50:     nz    = ai[r[i]+1] - ai[r[i]];
 51:     ajtmp = aj + ai[r[i]];
 52:     v     = aa + bs2*ai[r[i]];
 53:     for (j=0; j<nz; j++) {
 54:       PetscMemcpy(rtmp+bs2*ic[ajtmp[j]],v+bs2*j,bs2*sizeof(MatScalar));
 55:     }

 57:     /* elimination */
 58:     bjtmp = bj + bi[i];
 59:     nzL   = bi[i+1] - bi[i];
 60:     for (k=0; k < nzL; k++) {
 61:       row = bjtmp[k];
 62:       pc  = rtmp + bs2*row;
 63:       for (flg=0,j=0; j<bs2; j++) {
 64:         if (pc[j] != (PetscScalar)0.0) {
 65:           flg = 1;
 66:           break;
 67:         }
 68:       }
 69:       if (flg) {
 70:         pv = b->a + bs2*bdiag[row];
 71:         /* PetscKernel_A_gets_A_times_B(bs,pc,pv,mwork); *pc = *pc * (*pv); */
 72:         PetscKernel_A_gets_A_times_B_2(pc,pv,mwork);

 74:         pj = b->j + bdiag[row+1]+1; /* begining of U(row,:) */
 75:         pv = b->a + bs2*(bdiag[row+1]+1);
 76:         nz = bdiag[row] - bdiag[row+1] - 1; /* num of entries inU(row,:), excluding diag */
 77:         for (j=0; j<nz; j++) {
 78:           /* PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); */
 79:           /* rtmp+bs2*pj[j] = rtmp+bs2*pj[j] - (*pc)*(pv+bs2*j) */
 80:           v    = rtmp + 4*pj[j];
 81:           PetscKernel_A_gets_A_minus_B_times_C_2(v,pc,pv);
 82:           pv  += 4;
 83:         }
 84:         PetscLogFlops(16*nz+12); /* flops = 2*bs^3*nz + 2*bs^3 - bs2) */
 85:       }
 86:     }

 88:     /* finished row so stick it into b->a */
 89:     /* L part */
 90:     pv = b->a + bs2*bi[i];
 91:     pj = b->j + bi[i];
 92:     nz = bi[i+1] - bi[i];
 93:     for (j=0; j<nz; j++) {
 94:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
 95:     }

 97:     /* Mark diagonal and invert diagonal for simplier triangular solves */
 98:     pv   = b->a + bs2*bdiag[i];
 99:     pj   = b->j + bdiag[i];
100:     PetscMemcpy(pv,rtmp+bs2*pj[0],bs2*sizeof(MatScalar));
101:     /* PetscKernel_A_gets_inverse_A(bs,pv,v_pivots,v_work); */
102:     PetscKernel_A_gets_inverse_A_2(pv,shift);

104:     /* U part */
105:     pv = b->a + bs2*(bdiag[i+1]+1);
106:     pj = b->j + bdiag[i+1]+1;
107:     nz = bdiag[i] - bdiag[i+1] - 1;
108:     for (j=0; j<nz; j++) {
109:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
110:     }
111:   }

113:   PetscFree2(rtmp,mwork);
114:   ISRestoreIndices(isicol,&ic);
115:   ISRestoreIndices(isrow,&r);

117:   C->ops->solve          = MatSolve_SeqBAIJ_2;
118:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_2;
119:   C->assembled           = PETSC_TRUE;

121:   PetscLogFlops(1.333333333333*2*2*2*n); /* from inverting diagonal blocks */
122:   return(0);
123: }

127: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering(Mat B,Mat A,const MatFactorInfo *info)
128: {
129:   Mat            C =B;
130:   Mat_SeqBAIJ    *a=(Mat_SeqBAIJ*)A->data,*b=(Mat_SeqBAIJ*)C->data;
132:   PetscInt       i,j,k,nz,nzL,row,*pj;
133:   const PetscInt n=a->mbs,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,bs2=a->bs2;
134:   const PetscInt *ajtmp,*bjtmp,*bdiag=b->diag;
135:   MatScalar      *rtmp,*pc,*mwork,*pv;
136:   MatScalar      *aa=a->a,*v;
137:   PetscInt       flg;
138:   PetscReal      shift = info->shiftamount;

141:   /* generate work space needed by the factorization */
142:   PetscMalloc2(bs2*n,&rtmp,bs2,&mwork);
143:   PetscMemzero(rtmp,bs2*n*sizeof(MatScalar));

145:   for (i=0; i<n; i++) {
146:     /* zero rtmp */
147:     /* L part */
148:     nz    = bi[i+1] - bi[i];
149:     bjtmp = bj + bi[i];
150:     for  (j=0; j<nz; j++) {
151:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
152:     }

154:     /* U part */
155:     nz    = bdiag[i] - bdiag[i+1];
156:     bjtmp = bj + bdiag[i+1]+1;
157:     for  (j=0; j<nz; j++) {
158:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
159:     }

161:     /* load in initial (unfactored row) */
162:     nz    = ai[i+1] - ai[i];
163:     ajtmp = aj + ai[i];
164:     v     = aa + bs2*ai[i];
165:     for (j=0; j<nz; j++) {
166:       PetscMemcpy(rtmp+bs2*ajtmp[j],v+bs2*j,bs2*sizeof(MatScalar));
167:     }

169:     /* elimination */
170:     bjtmp = bj + bi[i];
171:     nzL   = bi[i+1] - bi[i];
172:     for (k=0; k < nzL; k++) {
173:       row = bjtmp[k];
174:       pc  = rtmp + bs2*row;
175:       for (flg=0,j=0; j<bs2; j++) {
176:         if (pc[j]!=(PetscScalar)0.0) {
177:           flg = 1;
178:           break;
179:         }
180:       }
181:       if (flg) {
182:         pv = b->a + bs2*bdiag[row];
183:         /* PetscKernel_A_gets_A_times_B(bs,pc,pv,mwork); *pc = *pc * (*pv); */
184:         PetscKernel_A_gets_A_times_B_2(pc,pv,mwork);

186:         pj = b->j + bdiag[row+1]+1; /* beginning of U(row,:) */
187:         pv = b->a + bs2*(bdiag[row+1]+1);
188:         nz = bdiag[row]-bdiag[row+1] - 1; /* num of entries in U(row,:) excluding diag */
189:         for (j=0; j<nz; j++) {
190:           /* PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); */
191:           /* rtmp+bs2*pj[j] = rtmp+bs2*pj[j] - (*pc)*(pv+bs2*j) */
192:           v    = rtmp + 4*pj[j];
193:           PetscKernel_A_gets_A_minus_B_times_C_2(v,pc,pv);
194:           pv  += 4;
195:         }
196:         PetscLogFlops(16*nz+12); /* flops = 2*bs^3*nz + 2*bs^3 - bs2) */
197:       }
198:     }

200:     /* finished row so stick it into b->a */
201:     /* L part */
202:     pv = b->a + bs2*bi[i];
203:     pj = b->j + bi[i];
204:     nz = bi[i+1] - bi[i];
205:     for (j=0; j<nz; j++) {
206:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
207:     }

209:     /* Mark diagonal and invert diagonal for simplier triangular solves */
210:     pv   = b->a + bs2*bdiag[i];
211:     pj   = b->j + bdiag[i];
212:     PetscMemcpy(pv,rtmp+bs2*pj[0],bs2*sizeof(MatScalar));
213:     /* PetscKernel_A_gets_inverse_A(bs,pv,v_pivots,v_work); */
214:     PetscKernel_A_gets_inverse_A_2(pv,shift);

216:     /* U part */
217:     /*
218:     pv = b->a + bs2*bi[2*n-i];
219:     pj = b->j + bi[2*n-i];
220:     nz = bi[2*n-i+1] - bi[2*n-i] - 1;
221:     */
222:     pv = b->a + bs2*(bdiag[i+1]+1);
223:     pj = b->j + bdiag[i+1]+1;
224:     nz = bdiag[i] - bdiag[i+1] - 1;
225:     for (j=0; j<nz; j++) {
226:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
227:     }
228:   }
229:   PetscFree2(rtmp,mwork);

231:   C->ops->solve          = MatSolve_SeqBAIJ_2_NaturalOrdering;
232:   C->ops->forwardsolve   = MatForwardSolve_SeqBAIJ_2_NaturalOrdering;
233:   C->ops->backwardsolve  = MatBackwardSolve_SeqBAIJ_2_NaturalOrdering;
234:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_2_NaturalOrdering;
235:   C->assembled           = PETSC_TRUE;

237:   PetscLogFlops(1.333333333333*2*2*2*n); /* from inverting diagonal blocks */
238:   return(0);
239: }

243: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_2_inplace(Mat B,Mat A,const MatFactorInfo *info)
244: {
245:   Mat            C     = B;
246:   Mat_SeqBAIJ    *a    = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data;
247:   IS             isrow = b->row,isicol = b->icol;
249:   const PetscInt *r,*ic;
250:   PetscInt       i,j,n = a->mbs,*bi = b->i,*bj = b->j;
251:   PetscInt       *ajtmpold,*ajtmp,nz,row;
252:   PetscInt       *diag_offset=b->diag,idx,*ai=a->i,*aj=a->j,*pj;
253:   MatScalar      *pv,*v,*rtmp,m1,m2,m3,m4,*pc,*w,*x,x1,x2,x3,x4;
254:   MatScalar      p1,p2,p3,p4;
255:   MatScalar      *ba   = b->a,*aa = a->a;
256:   PetscReal      shift = info->shiftamount;

259:   ISGetIndices(isrow,&r);
260:   ISGetIndices(isicol,&ic);
261:   PetscMalloc1(4*(n+1),&rtmp);

263:   for (i=0; i<n; i++) {
264:     nz    = bi[i+1] - bi[i];
265:     ajtmp = bj + bi[i];
266:     for  (j=0; j<nz; j++) {
267:       x = rtmp+4*ajtmp[j]; x[0] = x[1] = x[2] = x[3] = 0.0;
268:     }
269:     /* load in initial (unfactored row) */
270:     idx      = r[i];
271:     nz       = ai[idx+1] - ai[idx];
272:     ajtmpold = aj + ai[idx];
273:     v        = aa + 4*ai[idx];
274:     for (j=0; j<nz; j++) {
275:       x    = rtmp+4*ic[ajtmpold[j]];
276:       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
277:       v   += 4;
278:     }
279:     row = *ajtmp++;
280:     while (row < i) {
281:       pc = rtmp + 4*row;
282:       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
283:       if (p1 != (PetscScalar)0.0 || p2 != (PetscScalar)0.0 || p3 != (PetscScalar)0.0 || p4 != (PetscScalar)0.0) {
284:         pv    = ba + 4*diag_offset[row];
285:         pj    = bj + diag_offset[row] + 1;
286:         x1    = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
287:         pc[0] = m1 = p1*x1 + p3*x2;
288:         pc[1] = m2 = p2*x1 + p4*x2;
289:         pc[2] = m3 = p1*x3 + p3*x4;
290:         pc[3] = m4 = p2*x3 + p4*x4;
291:         nz    = bi[row+1] - diag_offset[row] - 1;
292:         pv   += 4;
293:         for (j=0; j<nz; j++) {
294:           x1    = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
295:           x     = rtmp + 4*pj[j];
296:           x[0] -= m1*x1 + m3*x2;
297:           x[1] -= m2*x1 + m4*x2;
298:           x[2] -= m1*x3 + m3*x4;
299:           x[3] -= m2*x3 + m4*x4;
300:           pv   += 4;
301:         }
302:         PetscLogFlops(16.0*nz+12.0);
303:       }
304:       row = *ajtmp++;
305:     }
306:     /* finished row so stick it into b->a */
307:     pv = ba + 4*bi[i];
308:     pj = bj + bi[i];
309:     nz = bi[i+1] - bi[i];
310:     for (j=0; j<nz; j++) {
311:       x     = rtmp+4*pj[j];
312:       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
313:       pv   += 4;
314:     }
315:     /* invert diagonal block */
316:     w    = ba + 4*diag_offset[i];
317:     PetscKernel_A_gets_inverse_A_2(w,shift);
318:   }

320:   PetscFree(rtmp);
321:   ISRestoreIndices(isicol,&ic);
322:   ISRestoreIndices(isrow,&r);

324:   C->ops->solve          = MatSolve_SeqBAIJ_2_inplace;
325:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_2_inplace;
326:   C->assembled           = PETSC_TRUE;

328:   PetscLogFlops(1.333333333333*8*b->mbs); /* from inverting diagonal blocks */
329:   return(0);
330: }
331: /*
332:       Version for when blocks are 2 by 2 Using natural ordering
333: */
336: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering_inplace(Mat C,Mat A,const MatFactorInfo *info)
337: {
338:   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data;
340:   PetscInt       i,j,n = a->mbs,*bi = b->i,*bj = b->j;
341:   PetscInt       *ajtmpold,*ajtmp,nz,row;
342:   PetscInt       *diag_offset = b->diag,*ai=a->i,*aj=a->j,*pj;
343:   MatScalar      *pv,*v,*rtmp,*pc,*w,*x;
344:   MatScalar      p1,p2,p3,p4,m1,m2,m3,m4,x1,x2,x3,x4;
345:   MatScalar      *ba   = b->a,*aa = a->a;
346:   PetscReal      shift = info->shiftamount;

349:   PetscMalloc1(4*(n+1),&rtmp);
350:   for (i=0; i<n; i++) {
351:     nz    = bi[i+1] - bi[i];
352:     ajtmp = bj + bi[i];
353:     for  (j=0; j<nz; j++) {
354:       x    = rtmp+4*ajtmp[j];
355:       x[0] = x[1]  = x[2]  = x[3]  = 0.0;
356:     }
357:     /* load in initial (unfactored row) */
358:     nz       = ai[i+1] - ai[i];
359:     ajtmpold = aj + ai[i];
360:     v        = aa + 4*ai[i];
361:     for (j=0; j<nz; j++) {
362:       x    = rtmp+4*ajtmpold[j];
363:       x[0] = v[0];  x[1]  = v[1];  x[2]  = v[2];  x[3]  = v[3];
364:       v   += 4;
365:     }
366:     row = *ajtmp++;
367:     while (row < i) {
368:       pc = rtmp + 4*row;
369:       p1 = pc[0];  p2  = pc[1];  p3  = pc[2];  p4  = pc[3];
370:       if (p1 != (PetscScalar)0.0 || p2 != (PetscScalar)0.0 || p3 != (PetscScalar)0.0 || p4 != (PetscScalar)0.0) {
371:         pv    = ba + 4*diag_offset[row];
372:         pj    = bj + diag_offset[row] + 1;
373:         x1    = pv[0];  x2  = pv[1];  x3  = pv[2];  x4  = pv[3];
374:         pc[0] = m1 = p1*x1 + p3*x2;
375:         pc[1] = m2 = p2*x1 + p4*x2;
376:         pc[2] = m3 = p1*x3 + p3*x4;
377:         pc[3] = m4 = p2*x3 + p4*x4;
378:         nz    = bi[row+1] - diag_offset[row] - 1;
379:         pv   += 4;
380:         for (j=0; j<nz; j++) {
381:           x1    = pv[0];  x2  = pv[1];   x3 = pv[2];  x4  = pv[3];
382:           x     = rtmp + 4*pj[j];
383:           x[0] -= m1*x1 + m3*x2;
384:           x[1] -= m2*x1 + m4*x2;
385:           x[2] -= m1*x3 + m3*x4;
386:           x[3] -= m2*x3 + m4*x4;
387:           pv   += 4;
388:         }
389:         PetscLogFlops(16.0*nz+12.0);
390:       }
391:       row = *ajtmp++;
392:     }
393:     /* finished row so stick it into b->a */
394:     pv = ba + 4*bi[i];
395:     pj = bj + bi[i];
396:     nz = bi[i+1] - bi[i];
397:     for (j=0; j<nz; j++) {
398:       x     = rtmp+4*pj[j];
399:       pv[0] = x[0];  pv[1]  = x[1];  pv[2]  = x[2];  pv[3]  = x[3];
400:       /*
401:       printf(" col %d:",pj[j]);
402:       PetscInt j1;
403:       for (j1=0; j1<4; j1++) printf(" %g,",*(pv+j1));
404:       printf("\n");
405:       */
406:       pv += 4;
407:     }
408:     /* invert diagonal block */
409:     w = ba + 4*diag_offset[i];
410:     /*
411:     printf(" \n%d -th: diag: ",i);
412:     for (j=0; j<4; j++) {
413:       printf(" %g,",w[j]);
414:     }
415:     printf("\n----------------------------\n");
416:     */
417:     PetscKernel_A_gets_inverse_A_2(w,shift);
418:   }

420:   PetscFree(rtmp);

422:   C->ops->solve          = MatSolve_SeqBAIJ_2_NaturalOrdering_inplace;
423:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_2_NaturalOrdering_inplace;
424:   C->assembled           = PETSC_TRUE;

426:   PetscLogFlops(1.333333333333*8*b->mbs); /* from inverting diagonal blocks */
427:   return(0);
428: }

430: /* ----------------------------------------------------------- */
431: /*
432:      Version for when blocks are 1 by 1.
433: */
436: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_1(Mat B,Mat A,const MatFactorInfo *info)
437: {
438:   Mat             C     =B;
439:   Mat_SeqBAIJ     *a    =(Mat_SeqBAIJ*)A->data,*b=(Mat_SeqBAIJ*)C->data;
440:   IS              isrow = b->row,isicol = b->icol;
441:   PetscErrorCode  ierr;
442:   const PetscInt  *r,*ic,*ics;
443:   const PetscInt  n=a->mbs,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,*bdiag=b->diag;
444:   PetscInt        i,j,k,nz,nzL,row,*pj;
445:   const PetscInt  *ajtmp,*bjtmp;
446:   MatScalar       *rtmp,*pc,multiplier,*pv;
447:   const MatScalar *aa=a->a,*v;
448:   PetscBool       row_identity,col_identity;
449:   FactorShiftCtx  sctx;
450:   const PetscInt  *ddiag;
451:   PetscReal       rs;
452:   MatScalar       d;

455:   /* MatPivotSetUp(): initialize shift context sctx */
456:   PetscMemzero(&sctx,sizeof(FactorShiftCtx));

458:   if (info->shifttype == (PetscReal) MAT_SHIFT_POSITIVE_DEFINITE) { /* set sctx.shift_top=max{rs} */
459:     ddiag          = a->diag;
460:     sctx.shift_top = info->zeropivot;
461:     for (i=0; i<n; i++) {
462:       /* calculate sum(|aij|)-RealPart(aii), amt of shift needed for this row */
463:       d  = (aa)[ddiag[i]];
464:       rs = -PetscAbsScalar(d) - PetscRealPart(d);
465:       v  = aa+ai[i];
466:       nz = ai[i+1] - ai[i];
467:       for (j=0; j<nz; j++) rs += PetscAbsScalar(v[j]);
468:       if (rs>sctx.shift_top) sctx.shift_top = rs;
469:     }
470:     sctx.shift_top *= 1.1;
471:     sctx.nshift_max = 5;
472:     sctx.shift_lo   = 0.;
473:     sctx.shift_hi   = 1.;
474:   }

476:   ISGetIndices(isrow,&r);
477:   ISGetIndices(isicol,&ic);
478:   PetscMalloc1(n+1,&rtmp);
479:   ics  = ic;

481:   do {
482:     sctx.newshift = PETSC_FALSE;
483:     for (i=0; i<n; i++) {
484:       /* zero rtmp */
485:       /* L part */
486:       nz    = bi[i+1] - bi[i];
487:       bjtmp = bj + bi[i];
488:       for  (j=0; j<nz; j++) rtmp[bjtmp[j]] = 0.0;

490:       /* U part */
491:       nz    = bdiag[i]-bdiag[i+1];
492:       bjtmp = bj + bdiag[i+1]+1;
493:       for  (j=0; j<nz; j++) rtmp[bjtmp[j]] = 0.0;

495:       /* load in initial (unfactored row) */
496:       nz    = ai[r[i]+1] - ai[r[i]];
497:       ajtmp = aj + ai[r[i]];
498:       v     = aa + ai[r[i]];
499:       for (j=0; j<nz; j++) rtmp[ics[ajtmp[j]]] = v[j];

501:       /* ZeropivotApply() */
502:       rtmp[i] += sctx.shift_amount;  /* shift the diagonal of the matrix */

504:       /* elimination */
505:       bjtmp = bj + bi[i];
506:       row   = *bjtmp++;
507:       nzL   = bi[i+1] - bi[i];
508:       for (k=0; k < nzL; k++) {
509:         pc = rtmp + row;
510:         if (*pc != (PetscScalar)0.0) {
511:           pv         = b->a + bdiag[row];
512:           multiplier = *pc * (*pv);
513:           *pc        = multiplier;

515:           pj = b->j + bdiag[row+1]+1; /* beginning of U(row,:) */
516:           pv = b->a + bdiag[row+1]+1;
517:           nz = bdiag[row]-bdiag[row+1]-1; /* num of entries in U(row,:) excluding diag */
518:           for (j=0; j<nz; j++) rtmp[pj[j]] -= multiplier * pv[j];
519:           PetscLogFlops(2.0*nz);
520:         }
521:         row = *bjtmp++;
522:       }

524:       /* finished row so stick it into b->a */
525:       rs = 0.0;
526:       /* L part */
527:       pv = b->a + bi[i];
528:       pj = b->j + bi[i];
529:       nz = bi[i+1] - bi[i];
530:       for (j=0; j<nz; j++) {
531:         pv[j] = rtmp[pj[j]]; rs += PetscAbsScalar(pv[j]);
532:       }

534:       /* U part */
535:       pv = b->a + bdiag[i+1]+1;
536:       pj = b->j + bdiag[i+1]+1;
537:       nz = bdiag[i] - bdiag[i+1]-1;
538:       for (j=0; j<nz; j++) {
539:         pv[j] = rtmp[pj[j]]; rs += PetscAbsScalar(pv[j]);
540:       }

542:       sctx.rs = rs;
543:       sctx.pv = rtmp[i];
544:       MatPivotCheck(A,info,&sctx,i);
545:       if (sctx.newshift) break; /* break for-loop */
546:       rtmp[i] = sctx.pv; /* sctx.pv might be updated in the case of MAT_SHIFT_INBLOCKS */

548:       /* Mark diagonal and invert diagonal for simplier triangular solves */
549:       pv  = b->a + bdiag[i];
550:       *pv = (PetscScalar)1.0/rtmp[i];

552:     } /* endof for (i=0; i<n; i++) { */

554:     /* MatPivotRefine() */
555:     if (info->shifttype == (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE && !sctx.newshift && sctx.shift_fraction>0 && sctx.nshift<sctx.nshift_max) {
556:       /*
557:        * if no shift in this attempt & shifting & started shifting & can refine,
558:        * then try lower shift
559:        */
560:       sctx.shift_hi       = sctx.shift_fraction;
561:       sctx.shift_fraction = (sctx.shift_hi+sctx.shift_lo)/2.;
562:       sctx.shift_amount   = sctx.shift_fraction * sctx.shift_top;
563:       sctx.newshift       = PETSC_TRUE;
564:       sctx.nshift++;
565:     }
566:   } while (sctx.newshift);

568:   PetscFree(rtmp);
569:   ISRestoreIndices(isicol,&ic);
570:   ISRestoreIndices(isrow,&r);

572:   ISIdentity(isrow,&row_identity);
573:   ISIdentity(isicol,&col_identity);
574:   if (row_identity && col_identity) {
575:     C->ops->solve          = MatSolve_SeqBAIJ_1_NaturalOrdering;
576:     C->ops->forwardsolve   = MatForwardSolve_SeqBAIJ_1_NaturalOrdering;
577:     C->ops->backwardsolve  = MatBackwardSolve_SeqBAIJ_1_NaturalOrdering;
578:     C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_1_NaturalOrdering;
579:   } else {
580:     C->ops->solve          = MatSolve_SeqBAIJ_1;
581:     C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_1;
582:   }
583:   C->assembled = PETSC_TRUE;
584:   PetscLogFlops(C->cmap->n);

586:   /* MatShiftView(A,info,&sctx) */
587:   if (sctx.nshift) {
588:     if (info->shifttype == (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE) {
589:       PetscInfo4(A,"number of shift_pd tries %D, shift_amount %g, diagonal shifted up by %e fraction top_value %e\n",sctx.nshift,(double)sctx.shift_amount,(double)sctx.shift_fraction,(double)sctx.shift_top);
590:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_NONZERO) {
591:       PetscInfo2(A,"number of shift_nz tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
592:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_INBLOCKS) {
593:       PetscInfo2(A,"number of shift_inblocks applied %D, each shift_amount %g\n",sctx.nshift,(double)info->shiftamount);
594:     }
595:   }
596:   return(0);
597: }

601: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_1_inplace(Mat C,Mat A,const MatFactorInfo *info)
602: {
603:   Mat_SeqBAIJ    *a    = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data;
604:   IS             isrow = b->row,isicol = b->icol;
606:   const PetscInt *r,*ic;
607:   PetscInt       i,j,n = a->mbs,*bi = b->i,*bj = b->j;
608:   PetscInt       *ajtmpold,*ajtmp,nz,row,*ai = a->i,*aj = a->j;
609:   PetscInt       *diag_offset = b->diag,diag,*pj;
610:   MatScalar      *pv,*v,*rtmp,multiplier,*pc;
611:   MatScalar      *ba = b->a,*aa = a->a;
612:   PetscBool      row_identity, col_identity;

615:   ISGetIndices(isrow,&r);
616:   ISGetIndices(isicol,&ic);
617:   PetscMalloc1(n+1,&rtmp);

619:   for (i=0; i<n; i++) {
620:     nz    = bi[i+1] - bi[i];
621:     ajtmp = bj + bi[i];
622:     for  (j=0; j<nz; j++) rtmp[ajtmp[j]] = 0.0;

624:     /* load in initial (unfactored row) */
625:     nz       = ai[r[i]+1] - ai[r[i]];
626:     ajtmpold = aj + ai[r[i]];
627:     v        = aa + ai[r[i]];
628:     for (j=0; j<nz; j++) rtmp[ic[ajtmpold[j]]] =  v[j];

630:     row = *ajtmp++;
631:     while (row < i) {
632:       pc = rtmp + row;
633:       if (*pc != 0.0) {
634:         pv         = ba + diag_offset[row];
635:         pj         = bj + diag_offset[row] + 1;
636:         multiplier = *pc * *pv++;
637:         *pc        = multiplier;
638:         nz         = bi[row+1] - diag_offset[row] - 1;
639:         for (j=0; j<nz; j++) rtmp[pj[j]] -= multiplier * pv[j];
640:         PetscLogFlops(1.0+2.0*nz);
641:       }
642:       row = *ajtmp++;
643:     }
644:     /* finished row so stick it into b->a */
645:     pv = ba + bi[i];
646:     pj = bj + bi[i];
647:     nz = bi[i+1] - bi[i];
648:     for (j=0; j<nz; j++) pv[j] = rtmp[pj[j]];
649:     diag = diag_offset[i] - bi[i];
650:     /* check pivot entry for current row */
651:     if (pv[diag] == 0.0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_MAT_LU_ZRPVT,"Zero pivot: row in original ordering %D in permuted ordering %D",r[i],i);
652:     pv[diag] = 1.0/pv[diag];
653:   }

655:   PetscFree(rtmp);
656:   ISRestoreIndices(isicol,&ic);
657:   ISRestoreIndices(isrow,&r);
658:   ISIdentity(isrow,&row_identity);
659:   ISIdentity(isicol,&col_identity);
660:   if (row_identity && col_identity) {
661:     C->ops->solve          = MatSolve_SeqBAIJ_1_NaturalOrdering_inplace;
662:     C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_1_NaturalOrdering_inplace;
663:   } else {
664:     C->ops->solve          = MatSolve_SeqBAIJ_1_inplace;
665:     C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_1_inplace;
666:   }
667:   C->assembled = PETSC_TRUE;
668:   PetscLogFlops(C->cmap->n);
669:   return(0);
670: }

674: PETSC_EXTERN PetscErrorCode MatGetFactor_seqbaij_petsc(Mat A,MatFactorType ftype,Mat *B)
675: {
676:   PetscInt       n = A->rmap->n;

680: #if defined(PETSC_USE_COMPLEX)
681:   if (A->hermitian && (ftype == MAT_FACTOR_CHOLESKY || ftype == MAT_FACTOR_ICC)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Hermitian Factor is not supported");
682: #endif
683:   MatCreate(PetscObjectComm((PetscObject)A),B);
684:   MatSetSizes(*B,n,n,n,n);
685:   if (ftype == MAT_FACTOR_LU || ftype == MAT_FACTOR_ILU || ftype == MAT_FACTOR_ILUDT) {
686:     MatSetType(*B,MATSEQBAIJ);

688:     (*B)->ops->lufactorsymbolic  = MatLUFactorSymbolic_SeqBAIJ;
689:     (*B)->ops->ilufactorsymbolic = MatILUFactorSymbolic_SeqBAIJ;
690:   } else if (ftype == MAT_FACTOR_CHOLESKY || ftype == MAT_FACTOR_ICC) {
691:     MatSetType(*B,MATSEQSBAIJ);
692:     MatSeqSBAIJSetPreallocation(*B,A->rmap->bs,MAT_SKIP_ALLOCATION,NULL);

694:     (*B)->ops->iccfactorsymbolic      = MatICCFactorSymbolic_SeqBAIJ;
695:     (*B)->ops->choleskyfactorsymbolic = MatCholeskyFactorSymbolic_SeqBAIJ;
696:   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Factor type not supported");
697:   (*B)->factortype = ftype;
698:   return(0);
699: }

701: /* ----------------------------------------------------------- */
704: PetscErrorCode MatLUFactor_SeqBAIJ(Mat A,IS row,IS col,const MatFactorInfo *info)
705: {
707:   Mat            C;

710:   MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,&C);
711:   MatLUFactorSymbolic(C,A,row,col,info);
712:   MatLUFactorNumeric(C,A,info);

714:   A->ops->solve          = C->ops->solve;
715:   A->ops->solvetranspose = C->ops->solvetranspose;

717:   MatHeaderMerge(A,C);
718:   PetscLogObjectParent((PetscObject)A,(PetscObject)((Mat_SeqBAIJ*)(A->data))->icol);
719:   return(0);
720: }

722: #include <../src/mat/impls/sbaij/seq/sbaij.h>
725: PetscErrorCode MatCholeskyFactorNumeric_SeqBAIJ_N(Mat C,Mat A,const MatFactorInfo *info)
726: {
728:   Mat_SeqBAIJ    *a=(Mat_SeqBAIJ*)A->data;
729:   Mat_SeqSBAIJ   *b=(Mat_SeqSBAIJ*)C->data;
730:   IS             ip=b->row;
731:   const PetscInt *rip;
732:   PetscInt       i,j,mbs=a->mbs,bs=A->rmap->bs,*bi=b->i,*bj=b->j,*bcol;
733:   PetscInt       *ai=a->i,*aj=a->j;
734:   PetscInt       k,jmin,jmax,*jl,*il,col,nexti,ili,nz;
735:   MatScalar      *rtmp,*ba=b->a,*bval,*aa=a->a,dk,uikdi;
736:   PetscReal      rs;
737:   FactorShiftCtx sctx;

740:   if (bs > 1) { /* convert A to a SBAIJ matrix and apply Cholesky factorization from it */
741:     if (!a->sbaijMat) {
742:       MatConvert(A,MATSEQSBAIJ,MAT_INITIAL_MATRIX,&a->sbaijMat);
743:     }
744:     (a->sbaijMat)->ops->choleskyfactornumeric(C,a->sbaijMat,info);
745:     MatDestroy(&a->sbaijMat);
746:     return(0);
747:   }

749:   /* MatPivotSetUp(): initialize shift context sctx */
750:   PetscMemzero(&sctx,sizeof(FactorShiftCtx));

752:   ISGetIndices(ip,&rip);
753:   PetscMalloc3(mbs,&rtmp,mbs,&il,mbs,&jl);

755:   sctx.shift_amount = 0.;
756:   sctx.nshift       = 0;
757:   do {
758:     sctx.newshift = PETSC_FALSE;
759:     for (i=0; i<mbs; i++) {
760:       rtmp[i] = 0.0; jl[i] = mbs; il[0] = 0;
761:     }

763:     for (k = 0; k<mbs; k++) {
764:       bval = ba + bi[k];
765:       /* initialize k-th row by the perm[k]-th row of A */
766:       jmin = ai[rip[k]]; jmax = ai[rip[k]+1];
767:       for (j = jmin; j < jmax; j++) {
768:         col = rip[aj[j]];
769:         if (col >= k) { /* only take upper triangular entry */
770:           rtmp[col] = aa[j];
771:           *bval++   = 0.0; /* for in-place factorization */
772:         }
773:       }

775:       /* shift the diagonal of the matrix */
776:       if (sctx.nshift) rtmp[k] += sctx.shift_amount;

778:       /* modify k-th row by adding in those rows i with U(i,k)!=0 */
779:       dk = rtmp[k];
780:       i  = jl[k]; /* first row to be added to k_th row  */

782:       while (i < k) {
783:         nexti = jl[i]; /* next row to be added to k_th row */

785:         /* compute multiplier, update diag(k) and U(i,k) */
786:         ili     = il[i]; /* index of first nonzero element in U(i,k:bms-1) */
787:         uikdi   = -ba[ili]*ba[bi[i]]; /* diagonal(k) */
788:         dk     += uikdi*ba[ili];
789:         ba[ili] = uikdi; /* -U(i,k) */

791:         /* add multiple of row i to k-th row */
792:         jmin = ili + 1; jmax = bi[i+1];
793:         if (jmin < jmax) {
794:           for (j=jmin; j<jmax; j++) rtmp[bj[j]] += uikdi*ba[j];
795:           /* update il and jl for row i */
796:           il[i] = jmin;
797:           j     = bj[jmin]; jl[i] = jl[j]; jl[j] = i;
798:         }
799:         i = nexti;
800:       }

802:       /* shift the diagonals when zero pivot is detected */
803:       /* compute rs=sum of abs(off-diagonal) */
804:       rs   = 0.0;
805:       jmin = bi[k]+1;
806:       nz   = bi[k+1] - jmin;
807:       if (nz) {
808:         bcol = bj + jmin;
809:         while (nz--) {
810:           rs += PetscAbsScalar(rtmp[*bcol]);
811:           bcol++;
812:         }
813:       }

815:       sctx.rs = rs;
816:       sctx.pv = dk;
817:       MatPivotCheck(A,info,&sctx,k);
818:       if (sctx.newshift) break;
819:       dk = sctx.pv;

821:       /* copy data into U(k,:) */
822:       ba[bi[k]] = 1.0/dk; /* U(k,k) */
823:       jmin      = bi[k]+1; jmax = bi[k+1];
824:       if (jmin < jmax) {
825:         for (j=jmin; j<jmax; j++) {
826:           col = bj[j]; ba[j] = rtmp[col]; rtmp[col] = 0.0;
827:         }
828:         /* add the k-th row into il and jl */
829:         il[k] = jmin;
830:         i     = bj[jmin]; jl[k] = jl[i]; jl[i] = k;
831:       }
832:     }
833:   } while (sctx.newshift);
834:   PetscFree3(rtmp,il,jl);

836:   ISRestoreIndices(ip,&rip);

838:   C->assembled    = PETSC_TRUE;
839:   C->preallocated = PETSC_TRUE;

841:   PetscLogFlops(C->rmap->N);
842:   if (sctx.nshift) {
843:     if (info->shifttype == (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE) {
844:       PetscInfo2(A,"number of shiftpd tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
845:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_NONZERO) {
846:       PetscInfo2(A,"number of shiftnz tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
847:     }
848:   }
849:   return(0);
850: }

854: PetscErrorCode MatCholeskyFactorNumeric_SeqBAIJ_N_NaturalOrdering(Mat C,Mat A,const MatFactorInfo *info)
855: {
856:   Mat_SeqBAIJ    *a=(Mat_SeqBAIJ*)A->data;
857:   Mat_SeqSBAIJ   *b=(Mat_SeqSBAIJ*)C->data;
859:   PetscInt       i,j,am=a->mbs;
860:   PetscInt       *ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j;
861:   PetscInt       k,jmin,*jl,*il,nexti,ili,*acol,*bcol,nz;
862:   MatScalar      *rtmp,*ba=b->a,*aa=a->a,dk,uikdi,*aval,*bval;
863:   PetscReal      rs;
864:   FactorShiftCtx sctx;

867:   /* MatPivotSetUp(): initialize shift context sctx */
868:   PetscMemzero(&sctx,sizeof(FactorShiftCtx));

870:   PetscMalloc3(am,&rtmp,am,&il,am,&jl);

872:   do {
873:     sctx.newshift = PETSC_FALSE;
874:     for (i=0; i<am; i++) {
875:       rtmp[i] = 0.0; jl[i] = am; il[0] = 0;
876:     }

878:     for (k = 0; k<am; k++) {
879:       /* initialize k-th row with elements nonzero in row perm(k) of A */
880:       nz   = ai[k+1] - ai[k];
881:       acol = aj + ai[k];
882:       aval = aa + ai[k];
883:       bval = ba + bi[k];
884:       while (nz--) {
885:         if (*acol < k) { /* skip lower triangular entries */
886:           acol++; aval++;
887:         } else {
888:           rtmp[*acol++] = *aval++;
889:           *bval++       = 0.0; /* for in-place factorization */
890:         }
891:       }

893:       /* shift the diagonal of the matrix */
894:       if (sctx.nshift) rtmp[k] += sctx.shift_amount;

896:       /* modify k-th row by adding in those rows i with U(i,k)!=0 */
897:       dk = rtmp[k];
898:       i  = jl[k]; /* first row to be added to k_th row  */

900:       while (i < k) {
901:         nexti = jl[i]; /* next row to be added to k_th row */
902:         /* compute multiplier, update D(k) and U(i,k) */
903:         ili     = il[i]; /* index of first nonzero element in U(i,k:bms-1) */
904:         uikdi   = -ba[ili]*ba[bi[i]];
905:         dk     += uikdi*ba[ili];
906:         ba[ili] = uikdi; /* -U(i,k) */

908:         /* add multiple of row i to k-th row ... */
909:         jmin = ili + 1;
910:         nz   = bi[i+1] - jmin;
911:         if (nz > 0) {
912:           bcol = bj + jmin;
913:           bval = ba + jmin;
914:           while (nz--) rtmp[*bcol++] += uikdi*(*bval++);
915:           /* update il and jl for i-th row */
916:           il[i] = jmin;
917:           j     = bj[jmin]; jl[i] = jl[j]; jl[j] = i;
918:         }
919:         i = nexti;
920:       }

922:       /* shift the diagonals when zero pivot is detected */
923:       /* compute rs=sum of abs(off-diagonal) */
924:       rs   = 0.0;
925:       jmin = bi[k]+1;
926:       nz   = bi[k+1] - jmin;
927:       if (nz) {
928:         bcol = bj + jmin;
929:         while (nz--) {
930:           rs += PetscAbsScalar(rtmp[*bcol]);
931:           bcol++;
932:         }
933:       }

935:       sctx.rs = rs;
936:       sctx.pv = dk;
937:       MatPivotCheck(A,info,&sctx,k);
938:       if (sctx.newshift) break;    /* sctx.shift_amount is updated */
939:       dk = sctx.pv;

941:       /* copy data into U(k,:) */
942:       ba[bi[k]] = 1.0/dk;
943:       jmin      = bi[k]+1;
944:       nz        = bi[k+1] - jmin;
945:       if (nz) {
946:         bcol = bj + jmin;
947:         bval = ba + jmin;
948:         while (nz--) {
949:           *bval++       = rtmp[*bcol];
950:           rtmp[*bcol++] = 0.0;
951:         }
952:         /* add k-th row into il and jl */
953:         il[k] = jmin;
954:         i     = bj[jmin]; jl[k] = jl[i]; jl[i] = k;
955:       }
956:     }
957:   } while (sctx.newshift);
958:   PetscFree3(rtmp,il,jl);

960:   C->ops->solve          = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
961:   C->ops->solvetranspose = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
962:   C->assembled           = PETSC_TRUE;
963:   C->preallocated        = PETSC_TRUE;

965:   PetscLogFlops(C->rmap->N);
966:   if (sctx.nshift) {
967:     if (info->shifttype == (PetscReal)MAT_SHIFT_NONZERO) {
968:       PetscInfo2(A,"number of shiftnz tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
969:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE) {
970:       PetscInfo2(A,"number of shiftpd tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
971:     }
972:   }
973:   return(0);
974: }

976: #include <petscbt.h>
977: #include <../src/mat/utils/freespace.h>
980: PetscErrorCode MatICCFactorSymbolic_SeqBAIJ(Mat fact,Mat A,IS perm,const MatFactorInfo *info)
981: {
982:   Mat_SeqBAIJ        *a = (Mat_SeqBAIJ*)A->data;
983:   Mat_SeqSBAIJ       *b;
984:   Mat                B;
985:   PetscErrorCode     ierr;
986:   PetscBool          perm_identity,missing;
987:   PetscInt           reallocs=0,i,*ai=a->i,*aj=a->j,am=a->mbs,bs=A->rmap->bs,*ui;
988:   const PetscInt     *rip;
989:   PetscInt           jmin,jmax,nzk,k,j,*jl,prow,*il,nextprow;
990:   PetscInt           nlnk,*lnk,*lnk_lvl=NULL,ncols,ncols_upper,*cols,*cols_lvl,*uj,**uj_ptr,**uj_lvl_ptr;
991:   PetscReal          fill          =info->fill,levels=info->levels;
992:   PetscFreeSpaceList free_space    =NULL,current_space=NULL;
993:   PetscFreeSpaceList free_space_lvl=NULL,current_space_lvl=NULL;
994:   PetscBT            lnkbt;

997:   MatMissingDiagonal(A,&missing,&i);
998:   if (missing) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Matrix is missing diagonal entry %D",i);

1000:   if (bs > 1) {
1001:     if (!a->sbaijMat) {
1002:       MatConvert(A,MATSEQSBAIJ,MAT_INITIAL_MATRIX,&a->sbaijMat);
1003:     }
1004:     (fact)->ops->iccfactorsymbolic = MatICCFactorSymbolic_SeqSBAIJ;  /* undue the change made in MatGetFactor_seqbaij_petsc */

1006:     MatICCFactorSymbolic(fact,a->sbaijMat,perm,info);
1007:     return(0);
1008:   }

1010:   ISIdentity(perm,&perm_identity);
1011:   ISGetIndices(perm,&rip);

1013:   /* special case that simply copies fill pattern */
1014:   if (!levels && perm_identity) {
1015:     PetscMalloc1(am+1,&ui);
1016:     for (i=0; i<am; i++) ui[i] = ai[i+1] - a->diag[i]; /* ui: rowlengths - changes when !perm_identity */
1017:     B    = fact;
1018:     MatSeqSBAIJSetPreallocation(B,1,0,ui);


1021:     b  = (Mat_SeqSBAIJ*)B->data;
1022:     uj = b->j;
1023:     for (i=0; i<am; i++) {
1024:       aj = a->j + a->diag[i];
1025:       for (j=0; j<ui[i]; j++) *uj++ = *aj++;
1026:       b->ilen[i] = ui[i];
1027:     }
1028:     PetscFree(ui);

1030:     B->factortype = MAT_FACTOR_NONE;

1032:     MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
1033:     MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
1034:     B->factortype = MAT_FACTOR_ICC;

1036:     B->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqBAIJ_N_NaturalOrdering;
1037:     return(0);
1038:   }

1040:   /* initialization */
1041:   PetscMalloc1(am+1,&ui);
1042:   ui[0] = 0;
1043:   PetscMalloc1(2*am+1,&cols_lvl);

1045:   /* jl: linked list for storing indices of the pivot rows
1046:      il: il[i] points to the 1st nonzero entry of U(i,k:am-1) */
1047:   PetscMalloc4(am,&uj_ptr,am,&uj_lvl_ptr,am,&il,am,&jl);
1048:   for (i=0; i<am; i++) {
1049:     jl[i] = am; il[i] = 0;
1050:   }

1052:   /* create and initialize a linked list for storing column indices of the active row k */
1053:   nlnk = am + 1;
1054:   PetscIncompleteLLCreate(am,am,nlnk,lnk,lnk_lvl,lnkbt);

1056:   /* initial FreeSpace size is fill*(ai[am]+am)/2 */
1057:   PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+am)/2),&free_space);

1059:   current_space = free_space;

1061:   PetscFreeSpaceGet((PetscInt)(fill*(ai[am]+am)/2),&free_space_lvl);
1062:   current_space_lvl = free_space_lvl;

1064:   for (k=0; k<am; k++) {  /* for each active row k */
1065:     /* initialize lnk by the column indices of row rip[k] of A */
1066:     nzk         = 0;
1067:     ncols       = ai[rip[k]+1] - ai[rip[k]];
1068:     ncols_upper = 0;
1069:     cols        = cols_lvl + am;
1070:     for (j=0; j<ncols; j++) {
1071:       i = rip[*(aj + ai[rip[k]] + j)];
1072:       if (i >= k) { /* only take upper triangular entry */
1073:         cols[ncols_upper]     = i;
1074:         cols_lvl[ncols_upper] = -1;  /* initialize level for nonzero entries */
1075:         ncols_upper++;
1076:       }
1077:     }
1078:     PetscIncompleteLLAdd(ncols_upper,cols,levels,cols_lvl,am,nlnk,lnk,lnk_lvl,lnkbt);
1079:     nzk += nlnk;

1081:     /* update lnk by computing fill-in for each pivot row to be merged in */
1082:     prow = jl[k]; /* 1st pivot row */

1084:     while (prow < k) {
1085:       nextprow = jl[prow];

1087:       /* merge prow into k-th row */
1088:       jmin  = il[prow] + 1; /* index of the 2nd nzero entry in U(prow,k:am-1) */
1089:       jmax  = ui[prow+1];
1090:       ncols = jmax-jmin;
1091:       i     = jmin - ui[prow];
1092:       cols  = uj_ptr[prow] + i; /* points to the 2nd nzero entry in U(prow,k:am-1) */
1093:       for (j=0; j<ncols; j++) cols_lvl[j] = *(uj_lvl_ptr[prow] + i + j);
1094:       PetscIncompleteLLAddSorted(ncols,cols,levels,cols_lvl,am,nlnk,lnk,lnk_lvl,lnkbt);
1095:       nzk += nlnk;

1097:       /* update il and jl for prow */
1098:       if (jmin < jmax) {
1099:         il[prow] = jmin;

1101:         j = *cols; jl[prow] = jl[j]; jl[j] = prow;
1102:       }
1103:       prow = nextprow;
1104:     }

1106:     /* if free space is not available, make more free space */
1107:     if (current_space->local_remaining<nzk) {
1108:       i    = am - k + 1; /* num of unfactored rows */
1109:       i    = PetscMin(i*nzk, i*(i-1)); /* i*nzk, i*(i-1): estimated and max additional space needed */
1110:       PetscFreeSpaceGet(i,&current_space);
1111:       PetscFreeSpaceGet(i,&current_space_lvl);
1112:       reallocs++;
1113:     }

1115:     /* copy data into free_space and free_space_lvl, then initialize lnk */
1116:     PetscIncompleteLLClean(am,am,nzk,lnk,lnk_lvl,current_space->array,current_space_lvl->array,lnkbt);

1118:     /* add the k-th row into il and jl */
1119:     if (nzk-1 > 0) {
1120:       i     = current_space->array[1]; /* col value of the first nonzero element in U(k, k+1:am-1) */
1121:       jl[k] = jl[i]; jl[i] = k;
1122:       il[k] = ui[k] + 1;
1123:     }
1124:     uj_ptr[k]     = current_space->array;
1125:     uj_lvl_ptr[k] = current_space_lvl->array;

1127:     current_space->array           += nzk;
1128:     current_space->local_used      += nzk;
1129:     current_space->local_remaining -= nzk;

1131:     current_space_lvl->array           += nzk;
1132:     current_space_lvl->local_used      += nzk;
1133:     current_space_lvl->local_remaining -= nzk;

1135:     ui[k+1] = ui[k] + nzk;
1136:   }

1138:   ISRestoreIndices(perm,&rip);
1139:   PetscFree4(uj_ptr,uj_lvl_ptr,il,jl);
1140:   PetscFree(cols_lvl);

1142:   /* copy free_space into uj and free free_space; set uj in new datastructure; */
1143:   PetscMalloc1(ui[am]+1,&uj);
1144:   PetscFreeSpaceContiguous(&free_space,uj);
1145:   PetscIncompleteLLDestroy(lnk,lnkbt);
1146:   PetscFreeSpaceDestroy(free_space_lvl);

1148:   /* put together the new matrix in MATSEQSBAIJ format */
1149:   B    = fact;
1150:   MatSeqSBAIJSetPreallocation(B,1,MAT_SKIP_ALLOCATION,NULL);

1152:   b                = (Mat_SeqSBAIJ*)B->data;
1153:   b->singlemalloc  = PETSC_FALSE;
1154:   b->free_a        = PETSC_TRUE;
1155:   b->free_ij       = PETSC_TRUE;

1157:   PetscMalloc1(ui[am]+1,&b->a);

1159:   b->j             = uj;
1160:   b->i             = ui;
1161:   b->diag          = 0;
1162:   b->ilen          = 0;
1163:   b->imax          = 0;
1164:   b->row           = perm;
1165:   b->pivotinblocks = PETSC_FALSE; /* need to get from MatFactorInfo */

1167:   PetscObjectReference((PetscObject)perm);

1169:   b->icol = perm;

1171:   PetscObjectReference((PetscObject)perm);
1172:   PetscMalloc1(am+1,&b->solve_work);
1173:   PetscLogObjectMemory((PetscObject)B,(ui[am]-am)*(sizeof(PetscInt)+sizeof(MatScalar)));

1175:   b->maxnz = b->nz = ui[am];

1177:   B->info.factor_mallocs   = reallocs;
1178:   B->info.fill_ratio_given = fill;
1179:   if (ai[am] != 0.) {
1180:     /* nonzeros in lower triangular part of A (includign diagonals)= (ai[am]+am)/2 */
1181:     B->info.fill_ratio_needed = ((PetscReal)2*ui[am])/(ai[am]+am);
1182:   } else {
1183:     B->info.fill_ratio_needed = 0.0;
1184:   }
1185: #if defined(PETSC_USE_INFO)
1186:   if (ai[am] != 0) {
1187:     PetscReal af = B->info.fill_ratio_needed;
1188:     PetscInfo3(A,"Reallocs %D Fill ratio:given %g needed %g\n",reallocs,(double)fill,(double)af);
1189:     PetscInfo1(A,"Run with -pc_factor_fill %g or use \n",(double)af);
1190:     PetscInfo1(A,"PCFactorSetFill(pc,%g) for best performance.\n",(double)af);
1191:   } else {
1192:     PetscInfo(A,"Empty matrix.\n");
1193:   }
1194: #endif
1195:   if (perm_identity) {
1196:     B->ops->solve                 = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
1197:     B->ops->solvetranspose        = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
1198:     B->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqBAIJ_N_NaturalOrdering;
1199:   } else {
1200:     (fact)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqBAIJ_N;
1201:   }
1202:   return(0);
1203: }

1207: PetscErrorCode MatCholeskyFactorSymbolic_SeqBAIJ(Mat fact,Mat A,IS perm,const MatFactorInfo *info)
1208: {
1209:   Mat_SeqBAIJ        *a = (Mat_SeqBAIJ*)A->data;
1210:   Mat_SeqSBAIJ       *b;
1211:   Mat                B;
1212:   PetscErrorCode     ierr;
1213:   PetscBool          perm_identity,missing;
1214:   PetscReal          fill = info->fill;
1215:   const PetscInt     *rip;
1216:   PetscInt           i,mbs=a->mbs,bs=A->rmap->bs,*ai=a->i,*aj=a->j,reallocs=0,prow;
1217:   PetscInt           *jl,jmin,jmax,nzk,*ui,k,j,*il,nextprow;
1218:   PetscInt           nlnk,*lnk,ncols,ncols_upper,*cols,*uj,**ui_ptr,*uj_ptr;
1219:   PetscFreeSpaceList free_space=NULL,current_space=NULL;
1220:   PetscBT            lnkbt;

1223:   if (bs > 1) { /* convert to seqsbaij */
1224:     if (!a->sbaijMat) {
1225:       MatConvert(A,MATSEQSBAIJ,MAT_INITIAL_MATRIX,&a->sbaijMat);
1226:     }
1227:     (fact)->ops->choleskyfactorsymbolic = MatCholeskyFactorSymbolic_SeqSBAIJ; /* undue the change made in MatGetFactor_seqbaij_petsc */

1229:     MatCholeskyFactorSymbolic(fact,a->sbaijMat,perm,info);
1230:     return(0);
1231:   }

1233:   MatMissingDiagonal(A,&missing,&i);
1234:   if (missing) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Matrix is missing diagonal entry %D",i);

1236:   /* check whether perm is the identity mapping */
1237:   ISIdentity(perm,&perm_identity);
1238:   if (!perm_identity) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Matrix reordering is not supported");
1239:   ISGetIndices(perm,&rip);

1241:   /* initialization */
1242:   PetscMalloc1(mbs+1,&ui);
1243:   ui[0] = 0;

1245:   /* jl: linked list for storing indices of the pivot rows
1246:      il: il[i] points to the 1st nonzero entry of U(i,k:mbs-1) */
1247:   PetscMalloc4(mbs,&ui_ptr,mbs,&il,mbs,&jl,mbs,&cols);
1248:   for (i=0; i<mbs; i++) {
1249:     jl[i] = mbs; il[i] = 0;
1250:   }

1252:   /* create and initialize a linked list for storing column indices of the active row k */
1253:   nlnk = mbs + 1;
1254:   PetscLLCreate(mbs,mbs,nlnk,lnk,lnkbt);

1256:   /* initial FreeSpace size is fill* (ai[mbs]+mbs)/2 */
1257:   PetscFreeSpaceGet((PetscInt)(fill*(ai[mbs]+mbs)/2),&free_space);

1259:   current_space = free_space;

1261:   for (k=0; k<mbs; k++) {  /* for each active row k */
1262:     /* initialize lnk by the column indices of row rip[k] of A */
1263:     nzk         = 0;
1264:     ncols       = ai[rip[k]+1] - ai[rip[k]];
1265:     ncols_upper = 0;
1266:     for (j=0; j<ncols; j++) {
1267:       i = rip[*(aj + ai[rip[k]] + j)];
1268:       if (i >= k) { /* only take upper triangular entry */
1269:         cols[ncols_upper] = i;
1270:         ncols_upper++;
1271:       }
1272:     }
1273:     PetscLLAdd(ncols_upper,cols,mbs,nlnk,lnk,lnkbt);
1274:     nzk += nlnk;

1276:     /* update lnk by computing fill-in for each pivot row to be merged in */
1277:     prow = jl[k]; /* 1st pivot row */

1279:     while (prow < k) {
1280:       nextprow = jl[prow];
1281:       /* merge prow into k-th row */
1282:       jmin   = il[prow] + 1; /* index of the 2nd nzero entry in U(prow,k:mbs-1) */
1283:       jmax   = ui[prow+1];
1284:       ncols  = jmax-jmin;
1285:       uj_ptr = ui_ptr[prow] + jmin - ui[prow]; /* points to the 2nd nzero entry in U(prow,k:mbs-1) */
1286:       PetscLLAddSorted(ncols,uj_ptr,mbs,nlnk,lnk,lnkbt);
1287:       nzk   += nlnk;

1289:       /* update il and jl for prow */
1290:       if (jmin < jmax) {
1291:         il[prow] = jmin;
1292:         j        = *uj_ptr;
1293:         jl[prow] = jl[j];
1294:         jl[j]    = prow;
1295:       }
1296:       prow = nextprow;
1297:     }

1299:     /* if free space is not available, make more free space */
1300:     if (current_space->local_remaining<nzk) {
1301:       i    = mbs - k + 1; /* num of unfactored rows */
1302:       i    = PetscMin(i*nzk, i*(i-1)); /* i*nzk, i*(i-1): estimated and max additional space needed */
1303:       PetscFreeSpaceGet(i,&current_space);
1304:       reallocs++;
1305:     }

1307:     /* copy data into free space, then initialize lnk */
1308:     PetscLLClean(mbs,mbs,nzk,lnk,current_space->array,lnkbt);

1310:     /* add the k-th row into il and jl */
1311:     if (nzk-1 > 0) {
1312:       i     = current_space->array[1]; /* col value of the first nonzero element in U(k, k+1:mbs-1) */
1313:       jl[k] = jl[i]; jl[i] = k;
1314:       il[k] = ui[k] + 1;
1315:     }
1316:     ui_ptr[k]                       = current_space->array;
1317:     current_space->array           += nzk;
1318:     current_space->local_used      += nzk;
1319:     current_space->local_remaining -= nzk;

1321:     ui[k+1] = ui[k] + nzk;
1322:   }

1324:   ISRestoreIndices(perm,&rip);
1325:   PetscFree4(ui_ptr,il,jl,cols);

1327:   /* copy free_space into uj and free free_space; set uj in new datastructure; */
1328:   PetscMalloc1(ui[mbs]+1,&uj);
1329:   PetscFreeSpaceContiguous(&free_space,uj);
1330:   PetscLLDestroy(lnk,lnkbt);

1332:   /* put together the new matrix in MATSEQSBAIJ format */
1333:   B    = fact;
1334:   MatSeqSBAIJSetPreallocation(B,bs,MAT_SKIP_ALLOCATION,NULL);

1336:   b               = (Mat_SeqSBAIJ*)B->data;
1337:   b->singlemalloc = PETSC_FALSE;
1338:   b->free_a       = PETSC_TRUE;
1339:   b->free_ij      = PETSC_TRUE;

1341:   PetscMalloc1(ui[mbs]+1,&b->a);

1343:   b->j             = uj;
1344:   b->i             = ui;
1345:   b->diag          = 0;
1346:   b->ilen          = 0;
1347:   b->imax          = 0;
1348:   b->row           = perm;
1349:   b->pivotinblocks = PETSC_FALSE; /* need to get from MatFactorInfo */

1351:   PetscObjectReference((PetscObject)perm);
1352:   b->icol  = perm;
1353:   PetscObjectReference((PetscObject)perm);
1354:   PetscMalloc1(mbs+1,&b->solve_work);
1355:   PetscLogObjectMemory((PetscObject)B,(ui[mbs]-mbs)*(sizeof(PetscInt)+sizeof(MatScalar)));
1356:   b->maxnz = b->nz = ui[mbs];

1358:   B->info.factor_mallocs   = reallocs;
1359:   B->info.fill_ratio_given = fill;
1360:   if (ai[mbs] != 0.) {
1361:     /* nonzeros in lower triangular part of A = (ai[mbs]+mbs)/2 */
1362:     B->info.fill_ratio_needed = ((PetscReal)2*ui[mbs])/(ai[mbs]+mbs);
1363:   } else {
1364:     B->info.fill_ratio_needed = 0.0;
1365:   }
1366: #if defined(PETSC_USE_INFO)
1367:   if (ai[mbs] != 0.) {
1368:     PetscReal af = B->info.fill_ratio_needed;
1369:     PetscInfo3(A,"Reallocs %D Fill ratio:given %g needed %g\n",reallocs,(double)fill,(double)af);
1370:     PetscInfo1(A,"Run with -pc_factor_fill %g or use \n",(double)af);
1371:     PetscInfo1(A,"PCFactorSetFill(pc,%g) for best performance.\n",(double)af);
1372:   } else {
1373:     PetscInfo(A,"Empty matrix.\n");
1374:   }
1375: #endif
1376:   if (perm_identity) {
1377:     B->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqBAIJ_N_NaturalOrdering;
1378:   } else {
1379:     B->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqBAIJ_N;
1380:   }
1381:   return(0);
1382: }

1386: PetscErrorCode MatSolve_SeqBAIJ_N_NaturalOrdering(Mat A,Vec bb,Vec xx)
1387: {
1388:   Mat_SeqBAIJ       *a=(Mat_SeqBAIJ*)A->data;
1389:   PetscErrorCode    ierr;
1390:   const PetscInt    *ai=a->i,*aj=a->j,*adiag=a->diag,*vi;
1391:   PetscInt          i,k,n=a->mbs;
1392:   PetscInt          nz,bs=A->rmap->bs,bs2=a->bs2;
1393:   const MatScalar   *aa=a->a,*v;
1394:   PetscScalar       *x,*s,*t,*ls;
1395:   const PetscScalar *b;

1398:   VecGetArrayRead(bb,&b);
1399:   VecGetArray(xx,&x);
1400:   t    = a->solve_work;

1402:   /* forward solve the lower triangular */
1403:   PetscMemcpy(t,b,bs*sizeof(PetscScalar)); /* copy 1st block of b to t */

1405:   for (i=1; i<n; i++) {
1406:     v    = aa + bs2*ai[i];
1407:     vi   = aj + ai[i];
1408:     nz   = ai[i+1] - ai[i];
1409:     s    = t + bs*i;
1410:     PetscMemcpy(s,b+bs*i,bs*sizeof(PetscScalar)); /* copy i_th block of b to t */
1411:     for (k=0;k<nz;k++) {
1412:       PetscKernel_v_gets_v_minus_A_times_w(bs,s,v,t+bs*vi[k]);
1413:       v += bs2;
1414:     }
1415:   }

1417:   /* backward solve the upper triangular */
1418:   ls = a->solve_work + A->cmap->n;
1419:   for (i=n-1; i>=0; i--) {
1420:     v    = aa + bs2*(adiag[i+1]+1);
1421:     vi   = aj + adiag[i+1]+1;
1422:     nz   = adiag[i] - adiag[i+1]-1;
1423:     PetscMemcpy(ls,t+i*bs,bs*sizeof(PetscScalar));
1424:     for (k=0; k<nz; k++) {
1425:       PetscKernel_v_gets_v_minus_A_times_w(bs,ls,v,t+bs*vi[k]);
1426:       v += bs2;
1427:     }
1428:     PetscKernel_w_gets_A_times_v(bs,ls,aa+bs2*adiag[i],t+i*bs); /* *inv(diagonal[i]) */
1429:     PetscMemcpy(x+i*bs,t+i*bs,bs*sizeof(PetscScalar));
1430:   }

1432:   VecRestoreArrayRead(bb,&b);
1433:   VecRestoreArray(xx,&x);
1434:   PetscLogFlops(2.0*(a->bs2)*(a->nz) - A->rmap->bs*A->cmap->n);
1435:   return(0);
1436: }

1440: PetscErrorCode MatSolve_SeqBAIJ_N(Mat A,Vec bb,Vec xx)
1441: {
1442:   Mat_SeqBAIJ        *a   =(Mat_SeqBAIJ*)A->data;
1443:   IS                 iscol=a->col,isrow=a->row;
1444:   PetscErrorCode     ierr;
1445:   const PetscInt     *r,*c,*rout,*cout,*ai=a->i,*aj=a->j,*adiag=a->diag,*vi;
1446:   PetscInt           i,m,n=a->mbs;
1447:   PetscInt           nz,bs=A->rmap->bs,bs2=a->bs2;
1448:   const MatScalar    *aa=a->a,*v;
1449:   PetscScalar        *x,*s,*t,*ls;
1450:   const PetscScalar  *b;

1453:   VecGetArrayRead(bb,&b);
1454:   VecGetArray(xx,&x);
1455:   t    = a->solve_work;

1457:   ISGetIndices(isrow,&rout); r = rout;
1458:   ISGetIndices(iscol,&cout); c = cout;

1460:   /* forward solve the lower triangular */
1461:   PetscMemcpy(t,b+bs*r[0],bs*sizeof(PetscScalar));
1462:   for (i=1; i<n; i++) {
1463:     v    = aa + bs2*ai[i];
1464:     vi   = aj + ai[i];
1465:     nz   = ai[i+1] - ai[i];
1466:     s    = t + bs*i;
1467:     PetscMemcpy(s,b+bs*r[i],bs*sizeof(PetscScalar));
1468:     for (m=0; m<nz; m++) {
1469:       PetscKernel_v_gets_v_minus_A_times_w(bs,s,v,t+bs*vi[m]);
1470:       v += bs2;
1471:     }
1472:   }

1474:   /* backward solve the upper triangular */
1475:   ls = a->solve_work + A->cmap->n;
1476:   for (i=n-1; i>=0; i--) {
1477:     v    = aa + bs2*(adiag[i+1]+1);
1478:     vi   = aj + adiag[i+1]+1;
1479:     nz   = adiag[i] - adiag[i+1] - 1;
1480:     PetscMemcpy(ls,t+i*bs,bs*sizeof(PetscScalar));
1481:     for (m=0; m<nz; m++) {
1482:       PetscKernel_v_gets_v_minus_A_times_w(bs,ls,v,t+bs*vi[m]);
1483:       v += bs2;
1484:     }
1485:     PetscKernel_w_gets_A_times_v(bs,ls,v,t+i*bs); /* *inv(diagonal[i]) */
1486:     PetscMemcpy(x + bs*c[i],t+i*bs,bs*sizeof(PetscScalar));
1487:   }
1488:   ISRestoreIndices(isrow,&rout);
1489:   ISRestoreIndices(iscol,&cout);
1490:   VecRestoreArrayRead(bb,&b);
1491:   VecRestoreArray(xx,&x);
1492:   PetscLogFlops(2.0*(a->bs2)*(a->nz) - A->rmap->bs*A->cmap->n);
1493:   return(0);
1494: }

1498: /*
1499:     For each block in an block array saves the largest absolute value in the block into another array
1500: */
1501: static PetscErrorCode MatBlockAbs_private(PetscInt nbs,PetscInt bs2,PetscScalar *blockarray,PetscReal *absarray)
1502: {
1504:   PetscInt       i,j;

1507:   PetscMemzero(absarray,(nbs+1)*sizeof(PetscReal));
1508:   for (i=0; i<nbs; i++) {
1509:     for (j=0; j<bs2; j++) {
1510:       if (absarray[i] < PetscAbsScalar(blockarray[i*nbs+j])) absarray[i] = PetscAbsScalar(blockarray[i*nbs+j]);
1511:     }
1512:   }
1513:   return(0);
1514: }

1518: /*
1519:      This needs to be renamed and called by the regular MatILUFactor_SeqBAIJ when drop tolerance is used
1520: */
1521: PetscErrorCode MatILUDTFactor_SeqBAIJ(Mat A,IS isrow,IS iscol,const MatFactorInfo *info,Mat *fact)
1522: {
1523:   Mat            B = *fact;
1524:   Mat_SeqBAIJ    *a=(Mat_SeqBAIJ*)A->data,*b;
1525:   IS             isicol;
1527:   const PetscInt *r,*ic;
1528:   PetscInt       i,mbs=a->mbs,bs=A->rmap->bs,bs2=a->bs2,*ai=a->i,*aj=a->j,*ajtmp,*adiag;
1529:   PetscInt       *bi,*bj,*bdiag;

1531:   PetscInt  row,nzi,nzi_bl,nzi_bu,*im,dtcount,nzi_al,nzi_au;
1532:   PetscInt  nlnk,*lnk;
1533:   PetscBT   lnkbt;
1534:   PetscBool row_identity,icol_identity;
1535:   MatScalar *aatmp,*pv,*batmp,*ba,*rtmp,*pc,*multiplier,*vtmp;
1536:   PetscInt  j,nz,*pj,*bjtmp,k,ncut,*jtmp;

1538:   PetscReal dt=info->dt;          /* shift=info->shiftamount; */
1539:   PetscInt  nnz_max;
1540:   PetscBool missing;
1541:   PetscReal *vtmp_abs;
1542:   MatScalar *v_work;
1543:   PetscInt  *v_pivots;

1546:   /* ------- symbolic factorization, can be reused ---------*/
1547:   MatMissingDiagonal(A,&missing,&i);
1548:   if (missing) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Matrix is missing diagonal entry %D",i);
1549:   adiag=a->diag;

1551:   ISInvertPermutation(iscol,PETSC_DECIDE,&isicol);

1553:   /* bdiag is location of diagonal in factor */
1554:   PetscMalloc1(mbs+1,&bdiag);

1556:   /* allocate row pointers bi */
1557:   PetscMalloc1(2*mbs+2,&bi);

1559:   /* allocate bj and ba; max num of nonzero entries is (ai[n]+2*n*dtcount+2) */
1560:   dtcount = (PetscInt)info->dtcount;
1561:   if (dtcount > mbs-1) dtcount = mbs-1;
1562:   nnz_max = ai[mbs]+2*mbs*dtcount +2;
1563:   /* printf("MatILUDTFactor_SeqBAIJ, bs %d, ai[mbs] %d, nnz_max  %d, dtcount %d\n",bs,ai[mbs],nnz_max,dtcount); */
1564:   PetscMalloc1(nnz_max,&bj);
1565:   nnz_max = nnz_max*bs2;
1566:   PetscMalloc1(nnz_max,&ba);

1568:   /* put together the new matrix */
1569:   MatSeqBAIJSetPreallocation_SeqBAIJ(B,bs,MAT_SKIP_ALLOCATION,NULL);
1570:   PetscLogObjectParent((PetscObject)B,(PetscObject)isicol);

1572:   b               = (Mat_SeqBAIJ*)(B)->data;
1573:   b->free_a       = PETSC_TRUE;
1574:   b->free_ij      = PETSC_TRUE;
1575:   b->singlemalloc = PETSC_FALSE;

1577:   b->a    = ba;
1578:   b->j    = bj;
1579:   b->i    = bi;
1580:   b->diag = bdiag;
1581:   b->ilen = 0;
1582:   b->imax = 0;
1583:   b->row  = isrow;
1584:   b->col  = iscol;

1586:   PetscObjectReference((PetscObject)isrow);
1587:   PetscObjectReference((PetscObject)iscol);

1589:   b->icol  = isicol;
1590:   PetscMalloc1(bs*(mbs+1),&b->solve_work);
1591:   PetscLogObjectMemory((PetscObject)B,nnz_max*(sizeof(PetscInt)+sizeof(MatScalar)));
1592:   b->maxnz = nnz_max/bs2;

1594:   (B)->factortype            = MAT_FACTOR_ILUDT;
1595:   (B)->info.factor_mallocs   = 0;
1596:   (B)->info.fill_ratio_given = ((PetscReal)nnz_max)/((PetscReal)(ai[mbs]*bs2));
1597:   /* ------- end of symbolic factorization ---------*/
1598:   ISGetIndices(isrow,&r);
1599:   ISGetIndices(isicol,&ic);

1601:   /* linked list for storing column indices of the active row */
1602:   nlnk = mbs + 1;
1603:   PetscLLCreate(mbs,mbs,nlnk,lnk,lnkbt);

1605:   /* im: used by PetscLLAddSortedLU(); jtmp: working array for column indices of active row */
1606:   PetscMalloc2(mbs,&im,mbs,&jtmp);
1607:   /* rtmp, vtmp: working arrays for sparse and contiguous row entries of active row */
1608:   PetscMalloc2(mbs*bs2,&rtmp,mbs*bs2,&vtmp);
1609:   PetscMalloc1(mbs+1,&vtmp_abs);
1610:   PetscMalloc3(bs,&v_work,bs2,&multiplier,bs,&v_pivots);

1612:   bi[0]       = 0;
1613:   bdiag[0]    = (nnz_max/bs2)-1; /* location of diagonal in factor B */
1614:   bi[2*mbs+1] = bdiag[0]+1; /* endof bj and ba array */
1615:   for (i=0; i<mbs; i++) {
1616:     /* copy initial fill into linked list */
1617:     nzi = 0; /* nonzeros for active row i */
1618:     nzi = ai[r[i]+1] - ai[r[i]];
1619:     if (!nzi) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_MAT_LU_ZRPVT,"Empty row in matrix: row in original ordering %D in permuted ordering %D",r[i],i);
1620:     nzi_al = adiag[r[i]] - ai[r[i]];
1621:     nzi_au = ai[r[i]+1] - adiag[r[i]] -1;
1622:     /* printf("row %d, nzi_al/au %d %d\n",i,nzi_al,nzi_au); */

1624:     /* load in initial unfactored row */
1625:     ajtmp = aj + ai[r[i]];
1626:     PetscLLAddPerm(nzi,ajtmp,ic,mbs,nlnk,lnk,lnkbt);
1627:     PetscMemzero(rtmp,mbs*bs2*sizeof(PetscScalar));
1628:     aatmp = a->a + bs2*ai[r[i]];
1629:     for (j=0; j<nzi; j++) {
1630:       PetscMemcpy(rtmp+bs2*ic[ajtmp[j]],aatmp+bs2*j,bs2*sizeof(MatScalar));
1631:     }

1633:     /* add pivot rows into linked list */
1634:     row = lnk[mbs];
1635:     while (row < i) {
1636:       nzi_bl = bi[row+1] - bi[row] + 1;
1637:       bjtmp  = bj + bdiag[row+1]+1; /* points to 1st column next to the diagonal in U */
1638:       PetscLLAddSortedLU(bjtmp,row,nlnk,lnk,lnkbt,i,nzi_bl,im);
1639:       nzi   += nlnk;
1640:       row    = lnk[row];
1641:     }

1643:     /* copy data from lnk into jtmp, then initialize lnk */
1644:     PetscLLClean(mbs,mbs,nzi,lnk,jtmp,lnkbt);

1646:     /* numerical factorization */
1647:     bjtmp = jtmp;
1648:     row   = *bjtmp++; /* 1st pivot row */

1650:     while  (row < i) {
1651:       pc = rtmp + bs2*row;
1652:       pv = ba + bs2*bdiag[row]; /* inv(diag) of the pivot row */
1653:       PetscKernel_A_gets_A_times_B(bs,pc,pv,multiplier); /* pc= multiplier = pc*inv(diag[row]) */
1654:       MatBlockAbs_private(1,bs2,pc,vtmp_abs);
1655:       if (vtmp_abs[0] > dt) { /* apply tolerance dropping rule */
1656:         pj = bj + bdiag[row+1] + 1;         /* point to 1st entry of U(row,:) */
1657:         pv = ba + bs2*(bdiag[row+1] + 1);
1658:         nz = bdiag[row] - bdiag[row+1] - 1;         /* num of entries in U(row,:), excluding diagonal */
1659:         for (j=0; j<nz; j++) {
1660:           PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j);
1661:         }
1662:         /* PetscLogFlops(bslog*(nz+1.0)-bs); */
1663:       }
1664:       row = *bjtmp++;
1665:     }

1667:     /* copy sparse rtmp into contiguous vtmp; separate L and U part */
1668:     nzi_bl = 0; j = 0;
1669:     while (jtmp[j] < i) { /* L-part. Note: jtmp is sorted */
1670:       PetscMemcpy(vtmp+bs2*j,rtmp+bs2*jtmp[j],bs2*sizeof(MatScalar));
1671:       nzi_bl++; j++;
1672:     }
1673:     nzi_bu = nzi - nzi_bl -1;
1674:     /* printf("nzi %d, nzi_bl %d, nzi_bu %d\n",nzi,nzi_bl,nzi_bu); */

1676:     while (j < nzi) { /* U-part */
1677:       PetscMemcpy(vtmp+bs2*j,rtmp+bs2*jtmp[j],bs2*sizeof(MatScalar));
1678:       /*
1679:       printf(" col %d: ",jtmp[j]);
1680:       for (j1=0; j1<bs2; j1++) printf(" %g",*(vtmp+bs2*j+j1));
1681:       printf(" \n");
1682:       */
1683:       j++;
1684:     }

1686:     MatBlockAbs_private(nzi,bs2,vtmp,vtmp_abs);
1687:     /*
1688:     printf(" row %d, nzi %d, vtmp_abs\n",i,nzi);
1689:     for (j1=0; j1<nzi; j1++) printf(" (%d %g),",jtmp[j1],vtmp_abs[j1]);
1690:     printf(" \n");
1691:     */
1692:     bjtmp = bj + bi[i];
1693:     batmp = ba + bs2*bi[i];
1694:     /* apply level dropping rule to L part */
1695:     ncut = nzi_al + dtcount;
1696:     if (ncut < nzi_bl) {
1697:       PetscSortSplitReal(ncut,nzi_bl,vtmp_abs,jtmp);
1698:       PetscSortIntWithScalarArray(ncut,jtmp,vtmp);
1699:     } else {
1700:       ncut = nzi_bl;
1701:     }
1702:     for (j=0; j<ncut; j++) {
1703:       bjtmp[j] = jtmp[j];
1704:       PetscMemcpy(batmp+bs2*j,rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
1705:       /*
1706:       printf(" col %d: ",bjtmp[j]);
1707:       for (j1=0; j1<bs2; j1++) printf(" %g,",*(batmp+bs2*j+j1));
1708:       printf("\n");
1709:       */
1710:     }
1711:     bi[i+1] = bi[i] + ncut;
1712:     nzi     = ncut + 1;

1714:     /* apply level dropping rule to U part */
1715:     ncut = nzi_au + dtcount;
1716:     if (ncut < nzi_bu) {
1717:       PetscSortSplitReal(ncut,nzi_bu,vtmp_abs+nzi_bl+1,jtmp+nzi_bl+1);
1718:       PetscSortIntWithScalarArray(ncut,jtmp+nzi_bl+1,vtmp+nzi_bl+1);
1719:     } else {
1720:       ncut = nzi_bu;
1721:     }
1722:     nzi += ncut;

1724:     /* mark bdiagonal */
1725:     bdiag[i+1]    = bdiag[i] - (ncut + 1);
1726:     bi[2*mbs - i] = bi[2*mbs - i +1] - (ncut + 1);

1728:     bjtmp  = bj + bdiag[i];
1729:     batmp  = ba + bs2*bdiag[i];
1730:     PetscMemcpy(batmp,rtmp+bs2*i,bs2*sizeof(MatScalar));
1731:     *bjtmp = i;
1732:     /*
1733:     printf(" diag %d: ",*bjtmp);
1734:     for (j=0; j<bs2; j++) {
1735:       printf(" %g,",batmp[j]);
1736:     }
1737:     printf("\n");
1738:     */
1739:     bjtmp = bj + bdiag[i+1]+1;
1740:     batmp = ba + (bdiag[i+1]+1)*bs2;

1742:     for (k=0; k<ncut; k++) {
1743:       bjtmp[k] = jtmp[nzi_bl+1+k];
1744:       PetscMemcpy(batmp+bs2*k,rtmp+bs2*bjtmp[k],bs2*sizeof(MatScalar));
1745:       /*
1746:       printf(" col %d:",bjtmp[k]);
1747:       for (j1=0; j1<bs2; j1++) printf(" %g,",*(batmp+bs2*k+j1));
1748:       printf("\n");
1749:       */
1750:     }

1752:     im[i] = nzi; /* used by PetscLLAddSortedLU() */

1754:     /* invert diagonal block for simplier triangular solves - add shift??? */
1755:     batmp = ba + bs2*bdiag[i];
1756:     PetscKernel_A_gets_inverse_A(bs,batmp,v_pivots,v_work);
1757:   } /* for (i=0; i<mbs; i++) */
1758:   PetscFree3(v_work,multiplier,v_pivots);

1760:   /* printf("end of L %d, beginning of U %d\n",bi[mbs],bdiag[mbs]); */
1761:   if (bi[mbs] >= bdiag[mbs]) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"end of L array %d cannot >= the beginning of U array %d",bi[mbs],bdiag[mbs]);

1763:   ISRestoreIndices(isrow,&r);
1764:   ISRestoreIndices(isicol,&ic);

1766:   PetscLLDestroy(lnk,lnkbt);

1768:   PetscFree2(im,jtmp);
1769:   PetscFree2(rtmp,vtmp);

1771:   PetscLogFlops(bs2*B->cmap->n);
1772:   b->maxnz = b->nz = bi[mbs] + bdiag[0] - bdiag[mbs];

1774:   ISIdentity(isrow,&row_identity);
1775:   ISIdentity(isicol,&icol_identity);
1776:   if (row_identity && icol_identity) {
1777:     B->ops->solve = MatSolve_SeqBAIJ_N_NaturalOrdering;
1778:   } else {
1779:     B->ops->solve = MatSolve_SeqBAIJ_N;
1780:   }

1782:   B->ops->solveadd          = 0;
1783:   B->ops->solvetranspose    = 0;
1784:   B->ops->solvetransposeadd = 0;
1785:   B->ops->matsolve          = 0;
1786:   B->assembled              = PETSC_TRUE;
1787:   B->preallocated           = PETSC_TRUE;
1788:   return(0);
1789: }