Actual source code: lu.c

petsc-3.7.3 2016-07-24
Report Typos and Errors
  2: /*
  3:    Defines a direct factorization preconditioner for any Mat implementation
  4:    Note: this need not be consided a preconditioner since it supplies
  5:          a direct solver.
  6: */

  8: #include <../src/ksp/pc/impls/factor/lu/lu.h>  /*I "petscpc.h" I*/


 13: PetscErrorCode PCFactorReorderForNonzeroDiagonal_LU(PC pc,PetscReal z)
 14: {
 15:   PC_LU *lu = (PC_LU*)pc->data;

 18:   lu->nonzerosalongdiagonal = PETSC_TRUE;
 19:   if (z == PETSC_DECIDE) lu->nonzerosalongdiagonaltol = 1.e-10;
 20:   else lu->nonzerosalongdiagonaltol = z;
 21:   return(0);
 22: }

 26: PetscErrorCode PCFactorSetReuseOrdering_LU(PC pc,PetscBool flag)
 27: {
 28:   PC_LU *lu = (PC_LU*)pc->data;

 31:   lu->reuseordering = flag;
 32:   return(0);
 33: }

 37: PetscErrorCode PCFactorSetReuseFill_LU(PC pc,PetscBool flag)
 38: {
 39:   PC_LU *lu = (PC_LU*)pc->data;

 42:   lu->reusefill = flag;
 43:   return(0);
 44: }

 48: static PetscErrorCode PCSetFromOptions_LU(PetscOptionItems *PetscOptionsObject,PC pc)
 49: {
 50:   PC_LU          *lu = (PC_LU*)pc->data;
 52:   PetscBool      flg = PETSC_FALSE;
 53:   PetscReal      tol;

 56:   PetscOptionsHead(PetscOptionsObject,"LU options");
 57:   PCSetFromOptions_Factor(PetscOptionsObject,pc);

 59:   PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);
 60:   if (flg) {
 61:     tol  = PETSC_DECIDE;
 62:     PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,0);
 63:     PCFactorReorderForNonzeroDiagonal(pc,tol);
 64:   }
 65:   PetscOptionsTail();
 66:   return(0);
 67: }

 71: static PetscErrorCode PCView_LU(PC pc,PetscViewer viewer)
 72: {
 73:   PC_LU          *lu = (PC_LU*)pc->data;
 75:   PetscBool      iascii;

 78:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
 79:   if (iascii) {
 80:     if (lu->inplace) {
 81:       PetscViewerASCIIPrintf(viewer,"  LU: in-place factorization\n");
 82:     } else {
 83:       PetscViewerASCIIPrintf(viewer,"  LU: out-of-place factorization\n");
 84:     }

 86:     if (lu->reusefill)    {PetscViewerASCIIPrintf(viewer,"       Reusing fill from past factorization\n");}
 87:     if (lu->reuseordering) {PetscViewerASCIIPrintf(viewer,"       Reusing reordering from past factorization\n");}
 88:   }
 89:   PCView_Factor(pc,viewer);
 90:   return(0);
 91: }

 95: static PetscErrorCode PCSetUp_LU(PC pc)
 96: {
 98:   PC_LU          *dir = (PC_LU*)pc->data;
 99:   const MatSolverPackage stype;

102:   if (dir->reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->actualfill;

104:   MatSetErrorIfFailure(pc->pmat,pc->erroriffailure);
105:   if (dir->inplace) {
106:     if (dir->row && dir->col && dir->row != dir->col) {ISDestroy(&dir->row);}
107:     ISDestroy(&dir->col);
108:     MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);
109:     if (dir->row) {
110:       PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);
111:       PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);
112:     }
113:     MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);
114:     if (pc->pmat->errortype) { /* Factor() fails */
115:       pc->failedreason = (PCFailedReason)pc->pmat->errortype;
116:       return(0);
117:     }

119:     ((PC_Factor*)dir)->fact = pc->pmat;
120:   } else {
121:     MatInfo info;
122:     Mat     F;
123:     if (!pc->setupcalled) {
124:       MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);
125:       if (dir->nonzerosalongdiagonal) {
126:         MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);
127:       }
128:       if (dir->row) {
129:         PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);
130:         PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);
131:       }
132:       if (!((PC_Factor*)dir)->fact) {
133:         MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);
134:       }
135:       MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);
136:       MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);
137:       dir->actualfill = info.fill_ratio_needed;
138:       PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact);
139:     } else if (pc->flag != SAME_NONZERO_PATTERN) {
140:       if (!dir->reuseordering) {
141:         if (dir->row && dir->col && dir->row != dir->col) {ISDestroy(&dir->row);}
142:         ISDestroy(&dir->col);
143:         MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);
144:         if (dir->nonzerosalongdiagonal) {
145:           MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);
146:         }
147:         if (dir->row) {
148:           PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);
149:           PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);
150:         }
151:       }
152:       MatDestroy(&((PC_Factor*)dir)->fact);
153:       MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);
154:       MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);
155:       MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);
156:       dir->actualfill = info.fill_ratio_needed;
157:       PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact);
158:     }
159:     F = ((PC_Factor*)dir)->fact;
160:     if (F->errortype) { /* FactorSymbolic() fails */
161:       pc->failedreason = (PCFailedReason)F->errortype;
162:       return(0);
163:     }

165:     MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info);
166:     if (F->errortype) { /* FactorNumeric() fails */
167:       pc->failedreason = (PCFailedReason)F->errortype;
168:     }

170:   }

172:   PCFactorGetMatSolverPackage(pc,&stype);
173:   if (!stype) {
174:     PCFactorSetMatSolverPackage(pc,((PC_Factor*)dir)->fact->solvertype);
175:   }
176:   return(0);
177: }

181: static PetscErrorCode PCReset_LU(PC pc)
182: {
183:   PC_LU          *dir = (PC_LU*)pc->data;

187:   if (!dir->inplace && ((PC_Factor*)dir)->fact) {MatDestroy(&((PC_Factor*)dir)->fact);}
188:   if (dir->row && dir->col && dir->row != dir->col) {ISDestroy(&dir->row);}
189:   ISDestroy(&dir->col);
190:   return(0);
191: }

195: static PetscErrorCode PCDestroy_LU(PC pc)
196: {
197:   PC_LU          *dir = (PC_LU*)pc->data;

201:   PCReset_LU(pc);
202:   PetscFree(((PC_Factor*)dir)->ordering);
203:   PetscFree(((PC_Factor*)dir)->solvertype);
204:   PetscFree(pc->data);
205:   return(0);
206: }

210: static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y)
211: {
212:   PC_LU          *dir = (PC_LU*)pc->data;

216:   if (dir->inplace) {
217:     MatSolve(pc->pmat,x,y);
218:   } else {
219:     MatSolve(((PC_Factor*)dir)->fact,x,y);
220:   }
221:   return(0);
222: }

226: static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y)
227: {
228:   PC_LU          *dir = (PC_LU*)pc->data;

232:   if (dir->inplace) {
233:     MatSolveTranspose(pc->pmat,x,y);
234:   } else {
235:     MatSolveTranspose(((PC_Factor*)dir)->fact,x,y);
236:   }
237:   return(0);
238: }

240: /* -----------------------------------------------------------------------------------*/

244: PetscErrorCode  PCFactorSetUseInPlace_LU(PC pc,PetscBool flg)
245: {
246:   PC_LU *dir = (PC_LU*)pc->data;

249:   dir->inplace = flg;
250:   return(0);
251: }

255: PetscErrorCode  PCFactorGetUseInPlace_LU(PC pc,PetscBool *flg)
256: {
257:   PC_LU *dir = (PC_LU*)pc->data;

260:   *flg = dir->inplace;
261:   return(0);
262: }

264: /* ------------------------------------------------------------------------ */

266: /*MC
267:    PCLU - Uses a direct solver, based on LU factorization, as a preconditioner

269:    Options Database Keys:
270: +  -pc_factor_reuse_ordering - Activate PCFactorSetReuseOrdering()
271: .  -pc_factor_mat_solver_package - Actives PCFactorSetMatSolverPackage() to choose the direct solver, like superlu
272: .  -pc_factor_reuse_fill - Activates PCFactorSetReuseFill()
273: .  -pc_factor_fill <fill> - Sets fill amount
274: .  -pc_factor_in_place - Activates in-place factorization
275: .  -pc_factor_mat_ordering_type <nd,rcm,...> - Sets ordering routine
276: .  -pc_factor_pivot_in_blocks <true,false> - allow pivoting within the small blocks during factorization (may increase
277:                                          stability of factorization.
278: .  -pc_factor_shift_type <shifttype> - Sets shift type or PETSC_DECIDE for the default; use '-help' for a list of available types
279: .  -pc_factor_shift_amount <shiftamount> - Sets shift amount or PETSC_DECIDE for the default
280: -   -pc_factor_nonzeros_along_diagonal - permutes the rows and columns to try to put nonzero value along the
281:         diagonal.

283:    Notes: Not all options work for all matrix formats
284:           Run with -help to see additional options for particular matrix formats or factorization
285:           algorithms

287:    Level: beginner

289:    Concepts: LU factorization, direct solver

291:    Notes: Usually this will compute an "exact" solution in one iteration and does
292:           not need a Krylov method (i.e. you can use -ksp_type preonly, or
293:           KSPSetType(ksp,KSPPREONLY) for the Krylov method

295: .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC,
296:            PCILU, PCCHOLESKY, PCICC, PCFactorSetReuseOrdering(), PCFactorSetReuseFill(), PCFactorGetMatrix(),
297:            PCFactorSetFill(), PCFactorSetUseInPlace(), PCFactorSetMatOrderingType(), PCFactorSetColumnPivot(),
298:            PCFactorSetPivotingInBlocks(),PCFactorSetShiftType(),PCFactorSetShiftAmount()
299:            PCFactorReorderForNonzeroDiagonal()
300: M*/

304: PETSC_EXTERN PetscErrorCode PCCreate_LU(PC pc)
305: {
307:   PetscMPIInt    size;
308:   PC_LU          *dir;

311:   PetscNewLog(pc,&dir);

313:   MatFactorInfoInitialize(&((PC_Factor*)dir)->info);

315:   ((PC_Factor*)dir)->fact       = NULL;
316:   ((PC_Factor*)dir)->factortype = MAT_FACTOR_LU;
317:   dir->inplace                  = PETSC_FALSE;
318:   dir->nonzerosalongdiagonal    = PETSC_FALSE;

320:   ((PC_Factor*)dir)->info.fill          = 5.0;
321:   ((PC_Factor*)dir)->info.dtcol         = 1.e-6;  /* default to pivoting; this is only thing PETSc LU supports */
322:   ((PC_Factor*)dir)->info.shifttype     = (PetscReal)MAT_SHIFT_NONE;
323:   ((PC_Factor*)dir)->info.shiftamount   = 0.0;
324:   ((PC_Factor*)dir)->info.zeropivot     = 100.0*PETSC_MACHINE_EPSILON;
325:   ((PC_Factor*)dir)->info.pivotinblocks = 1.0;
326:   dir->col                              = 0;
327:   dir->row                              = 0;

329:   MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);
330:   if (size == 1) {
331:     PetscStrallocpy(MATORDERINGND,(char**)&((PC_Factor*)dir)->ordering);
332:   } else {
333:     PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)dir)->ordering);
334:   }
335:   dir->reusefill     = PETSC_FALSE;
336:   dir->reuseordering = PETSC_FALSE;
337:   pc->data           = (void*)dir;

339:   pc->ops->reset             = PCReset_LU;
340:   pc->ops->destroy           = PCDestroy_LU;
341:   pc->ops->apply             = PCApply_LU;
342:   pc->ops->applytranspose    = PCApplyTranspose_LU;
343:   pc->ops->setup             = PCSetUp_LU;
344:   pc->ops->setfromoptions    = PCSetFromOptions_LU;
345:   pc->ops->view              = PCView_LU;
346:   pc->ops->applyrichardson   = 0;
347:   pc->ops->getfactoredmatrix = PCFactorGetMatrix_Factor;

349:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUpMatSolverPackage_C",PCFactorSetUpMatSolverPackage_Factor);
350:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetMatSolverPackage_C",PCFactorGetMatSolverPackage_Factor);
351:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatSolverPackage_C",PCFactorSetMatSolverPackage_Factor);
352:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetZeroPivot_C",PCFactorSetZeroPivot_Factor);
353:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftType_C",PCFactorSetShiftType_Factor);
354:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftAmount_C",PCFactorSetShiftAmount_Factor);
355:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetFill_C",PCFactorSetFill_Factor);
356:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUseInPlace_C",PCFactorSetUseInPlace_LU);
357:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetUseInPlace_C",PCFactorGetUseInPlace_LU);
358:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatOrderingType_C",PCFactorSetMatOrderingType_Factor);
359:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetReuseOrdering_C",PCFactorSetReuseOrdering_LU);
360:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetReuseFill_C",PCFactorSetReuseFill_LU);
361:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetColumnPivot_C",PCFactorSetColumnPivot_Factor);
362:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetPivotInBlocks_C",PCFactorSetPivotInBlocks_Factor);
363:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C",PCFactorReorderForNonzeroDiagonal_LU);
364:   return(0);
365: }