Actual source code: lu.c
petsc-3.4.5 2014-06-29
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*/
12: PetscErrorCode PCFactorReorderForNonzeroDiagonal_LU(PC pc,PetscReal z)
13: {
14: PC_LU *lu = (PC_LU*)pc->data;
17: lu->nonzerosalongdiagonal = PETSC_TRUE;
18: if (z == PETSC_DECIDE) lu->nonzerosalongdiagonaltol = 1.e-10;
19: else lu->nonzerosalongdiagonaltol = z;
20: return(0);
21: }
25: PetscErrorCode PCFactorSetReuseOrdering_LU(PC pc,PetscBool flag)
26: {
27: PC_LU *lu = (PC_LU*)pc->data;
30: lu->reuseordering = flag;
31: return(0);
32: }
36: PetscErrorCode PCFactorSetReuseFill_LU(PC pc,PetscBool flag)
37: {
38: PC_LU *lu = (PC_LU*)pc->data;
41: lu->reusefill = flag;
42: return(0);
43: }
47: static PetscErrorCode PCSetFromOptions_LU(PC pc)
48: {
49: PC_LU *lu = (PC_LU*)pc->data;
51: PetscBool flg = PETSC_FALSE;
52: PetscReal tol;
55: PetscOptionsHead("LU options");
56: PCSetFromOptions_Factor(pc);
58: PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);
59: if (flg) {
60: tol = PETSC_DECIDE;
61: PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,0);
62: PCFactorReorderForNonzeroDiagonal(pc,tol);
63: }
64: PetscOptionsTail();
65: return(0);
66: }
70: static PetscErrorCode PCView_LU(PC pc,PetscViewer viewer)
71: {
72: PC_LU *lu = (PC_LU*)pc->data;
74: PetscBool iascii;
77: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
78: if (iascii) {
79: if (lu->inplace) {
80: PetscViewerASCIIPrintf(viewer," LU: in-place factorization\n");
81: } else {
82: PetscViewerASCIIPrintf(viewer," LU: out-of-place factorization\n");
83: }
85: if (lu->reusefill) {PetscViewerASCIIPrintf(viewer," Reusing fill from past factorization\n");}
86: if (lu->reuseordering) {PetscViewerASCIIPrintf(viewer," Reusing reordering from past factorization\n");}
87: }
88: PCView_Factor(pc,viewer);
89: return(0);
90: }
94: static PetscErrorCode PCSetUp_LU(PC pc)
95: {
97: PC_LU *dir = (PC_LU*)pc->data;
100: if (dir->reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->actualfill;
102: if (dir->inplace) {
103: if (dir->row && dir->col && dir->row != dir->col) {ISDestroy(&dir->row);}
104: ISDestroy(&dir->col);
105: MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);
106: if (dir->row) {
107: PetscLogObjectParent(pc,dir->row);
108: PetscLogObjectParent(pc,dir->col);
109: }
110: MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);
112: ((PC_Factor*)dir)->fact = pc->pmat;
113: } else {
114: MatInfo info;
115: if (!pc->setupcalled) {
116: MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);
117: if (dir->nonzerosalongdiagonal) {
118: MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);
119: }
120: if (dir->row) {
121: PetscLogObjectParent(pc,dir->row);
122: PetscLogObjectParent(pc,dir->col);
123: }
124: if (!((PC_Factor*)dir)->fact) {
125: MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);
126: }
127: MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);
128: MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);
129: dir->actualfill = info.fill_ratio_needed;
130: PetscLogObjectParent(pc,((PC_Factor*)dir)->fact);
131: } else if (pc->flag != SAME_NONZERO_PATTERN) {
132: if (!dir->reuseordering) {
133: if (dir->row && dir->col && dir->row != dir->col) {ISDestroy(&dir->row);}
134: ISDestroy(&dir->col);
135: MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);
136: if (dir->nonzerosalongdiagonal) {
137: MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);
138: }
139: if (dir->row) {
140: PetscLogObjectParent(pc,dir->row);
141: PetscLogObjectParent(pc,dir->col);
142: }
143: }
144: MatDestroy(&((PC_Factor*)dir)->fact);
145: MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);
146: MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);
147: MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);
148: dir->actualfill = info.fill_ratio_needed;
149: PetscLogObjectParent(pc,((PC_Factor*)dir)->fact);
150: }
151: if ((!pc->setupcalled) || pc->setupcalled) {
152: MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info);
153: }
154: }
155: return(0);
156: }
160: static PetscErrorCode PCReset_LU(PC pc)
161: {
162: PC_LU *dir = (PC_LU*)pc->data;
166: if (!dir->inplace && ((PC_Factor*)dir)->fact) {MatDestroy(&((PC_Factor*)dir)->fact);}
167: if (dir->row && dir->col && dir->row != dir->col) {ISDestroy(&dir->row);}
168: ISDestroy(&dir->col);
169: return(0);
170: }
174: static PetscErrorCode PCDestroy_LU(PC pc)
175: {
176: PC_LU *dir = (PC_LU*)pc->data;
180: PCReset_LU(pc);
181: PetscFree(((PC_Factor*)dir)->ordering);
182: PetscFree(((PC_Factor*)dir)->solvertype);
183: PetscFree(pc->data);
184: return(0);
185: }
189: static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y)
190: {
191: PC_LU *dir = (PC_LU*)pc->data;
195: if (dir->inplace) {
196: MatSolve(pc->pmat,x,y);
197: } else {
198: MatSolve(((PC_Factor*)dir)->fact,x,y);
199: }
200: return(0);
201: }
205: static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y)
206: {
207: PC_LU *dir = (PC_LU*)pc->data;
211: if (dir->inplace) {
212: MatSolveTranspose(pc->pmat,x,y);
213: } else {
214: MatSolveTranspose(((PC_Factor*)dir)->fact,x,y);
215: }
216: return(0);
217: }
219: /* -----------------------------------------------------------------------------------*/
223: PetscErrorCode PCFactorSetUseInPlace_LU(PC pc)
224: {
225: PC_LU *dir = (PC_LU*)pc->data;
228: dir->inplace = PETSC_TRUE;
229: return(0);
230: }
232: /* ------------------------------------------------------------------------ */
234: /*MC
235: PCLU - Uses a direct solver, based on LU factorization, as a preconditioner
237: Options Database Keys:
238: + -pc_factor_reuse_ordering - Activate PCFactorSetReuseOrdering()
239: . -pc_factor_mat_solver_package - Actives PCFactorSetMatSolverPackage() to choose the direct solver, like superlu
240: . -pc_factor_reuse_fill - Activates PCFactorSetReuseFill()
241: . -pc_factor_fill <fill> - Sets fill amount
242: . -pc_factor_in_place - Activates in-place factorization
243: . -pc_factor_mat_ordering_type <nd,rcm,...> - Sets ordering routine
244: . -pc_factor_pivot_in_blocks <true,false> - allow pivoting within the small blocks during factorization (may increase
245: stability of factorization.
246: . -pc_factor_shift_type <shifttype> - Sets shift type or PETSC_DECIDE for the default; use '-help' for a list of available types
247: . -pc_factor_shift_amount <shiftamount> - Sets shift amount or PETSC_DECIDE for the default
248: - -pc_factor_nonzeros_along_diagonal - permutes the rows and columns to try to put nonzero value along the
249: diagonal.
251: Notes: Not all options work for all matrix formats
252: Run with -help to see additional options for particular matrix formats or factorization
253: algorithms
255: Level: beginner
257: Concepts: LU factorization, direct solver
259: Notes: Usually this will compute an "exact" solution in one iteration and does
260: not need a Krylov method (i.e. you can use -ksp_type preonly, or
261: KSPSetType(ksp,KSPPREONLY) for the Krylov method
263: .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC,
264: PCILU, PCCHOLESKY, PCICC, PCFactorSetReuseOrdering(), PCFactorSetReuseFill(), PCFactorGetMatrix(),
265: PCFactorSetFill(), PCFactorSetUseInPlace(), PCFactorSetMatOrderingType(), PCFactorSetColumnPivot(),
266: PCFactorSetPivotingInBlocks(),PCFactorSetShiftType(),PCFactorSetShiftAmount()
267: PCFactorReorderForNonzeroDiagonal()
268: M*/
272: PETSC_EXTERN PetscErrorCode PCCreate_LU(PC pc)
273: {
275: PetscMPIInt size;
276: PC_LU *dir;
279: PetscNewLog(pc,PC_LU,&dir);
281: MatFactorInfoInitialize(&((PC_Factor*)dir)->info);
283: ((PC_Factor*)dir)->fact = NULL;
284: ((PC_Factor*)dir)->factortype = MAT_FACTOR_LU;
285: dir->inplace = PETSC_FALSE;
286: dir->nonzerosalongdiagonal = PETSC_FALSE;
288: ((PC_Factor*)dir)->info.fill = 5.0;
289: ((PC_Factor*)dir)->info.dtcol = 1.e-6; /* default to pivoting; this is only thing PETSc LU supports */
290: ((PC_Factor*)dir)->info.shifttype = (PetscReal)MAT_SHIFT_NONE;
291: ((PC_Factor*)dir)->info.shiftamount = 0.0;
292: ((PC_Factor*)dir)->info.zeropivot = 100.0*PETSC_MACHINE_EPSILON;
293: ((PC_Factor*)dir)->info.pivotinblocks = 1.0;
294: dir->col = 0;
295: dir->row = 0;
297: PetscStrallocpy(MATSOLVERPETSC,&((PC_Factor*)dir)->solvertype); /* default SolverPackage */
298: MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);
299: if (size == 1) {
300: PetscStrallocpy(MATORDERINGND,(char**)&((PC_Factor*)dir)->ordering);
301: } else {
302: PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)dir)->ordering);
303: }
304: dir->reusefill = PETSC_FALSE;
305: dir->reuseordering = PETSC_FALSE;
306: pc->data = (void*)dir;
308: pc->ops->reset = PCReset_LU;
309: pc->ops->destroy = PCDestroy_LU;
310: pc->ops->apply = PCApply_LU;
311: pc->ops->applytranspose = PCApplyTranspose_LU;
312: pc->ops->setup = PCSetUp_LU;
313: pc->ops->setfromoptions = PCSetFromOptions_LU;
314: pc->ops->view = PCView_LU;
315: pc->ops->applyrichardson = 0;
316: pc->ops->getfactoredmatrix = PCFactorGetMatrix_Factor;
318: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUpMatSolverPackage_C",PCFactorSetUpMatSolverPackage_Factor);
319: PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetMatSolverPackage_C",PCFactorGetMatSolverPackage_Factor);
320: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatSolverPackage_C",PCFactorSetMatSolverPackage_Factor);
321: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetZeroPivot_C",PCFactorSetZeroPivot_Factor);
322: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftType_C",PCFactorSetShiftType_Factor);
323: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftAmount_C",PCFactorSetShiftAmount_Factor);
324: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetFill_C",PCFactorSetFill_Factor);
325: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUseInPlace_C",PCFactorSetUseInPlace_LU);
326: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatOrderingType_C",PCFactorSetMatOrderingType_Factor);
327: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetReuseOrdering_C",PCFactorSetReuseOrdering_LU);
328: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetReuseFill_C",PCFactorSetReuseFill_LU);
329: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetColumnPivot_C",PCFactorSetColumnPivot_Factor);
330: PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetPivotInBlocks_C",PCFactorSetPivotInBlocks_Factor);
331: PetscObjectComposeFunction((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C",PCFactorReorderForNonzeroDiagonal_LU);
332: return(0);
333: }