xref: /petsc/src/ksp/pc/impls/factor/lu/lu.c (revision 1147fc2a6bf7922defbbca15fc6c33f234803ff0)
1 
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 */
7 
8 #include <../src/ksp/pc/impls/factor/lu/lu.h>  /*I "petscpc.h" I*/
9 
10 EXTERN_C_BEGIN
11 #undef __FUNCT__
12 #define __FUNCT__ "PCFactorReorderForNonzeroDiagonal_LU"
13 PetscErrorCode  PCFactorReorderForNonzeroDiagonal_LU(PC pc,PetscReal z)
14 {
15   PC_LU *lu = (PC_LU*)pc->data;
16 
17   PetscFunctionBegin;
18   lu->nonzerosalongdiagonal = PETSC_TRUE;
19   if (z == PETSC_DECIDE) {
20     lu->nonzerosalongdiagonaltol = 1.e-10;
21   } else {
22     lu->nonzerosalongdiagonaltol = z;
23   }
24   PetscFunctionReturn(0);
25 }
26 EXTERN_C_END
27 
28 EXTERN_C_BEGIN
29 #undef __FUNCT__
30 #define __FUNCT__ "PCFactorSetReuseOrdering_LU"
31 PetscErrorCode  PCFactorSetReuseOrdering_LU(PC pc,PetscBool  flag)
32 {
33   PC_LU *lu = (PC_LU*)pc->data;
34 
35   PetscFunctionBegin;
36   lu->reuseordering = flag;
37   PetscFunctionReturn(0);
38 }
39 EXTERN_C_END
40 
41 EXTERN_C_BEGIN
42 #undef __FUNCT__
43 #define __FUNCT__ "PCFactorSetReuseFill_LU"
44 PetscErrorCode  PCFactorSetReuseFill_LU(PC pc,PetscBool  flag)
45 {
46   PC_LU *lu = (PC_LU*)pc->data;
47 
48   PetscFunctionBegin;
49   lu->reusefill = flag;
50   PetscFunctionReturn(0);
51 }
52 EXTERN_C_END
53 
54 #undef __FUNCT__
55 #define __FUNCT__ "PCSetFromOptions_LU"
56 static PetscErrorCode PCSetFromOptions_LU(PC pc)
57 {
58   PC_LU           *lu = (PC_LU*)pc->data;
59   PetscErrorCode  ierr;
60   PetscBool       flg = PETSC_FALSE;
61   PetscReal       tol;
62 
63   PetscFunctionBegin;
64   ierr = PetscOptionsHead("LU options");CHKERRQ(ierr);
65     ierr = PCSetFromOptions_Factor(pc);CHKERRQ(ierr);
66 
67     ierr = PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);CHKERRQ(ierr);
68     if (flg) {
69       tol = PETSC_DECIDE;
70       ierr = PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,0);CHKERRQ(ierr);
71       ierr = PCFactorReorderForNonzeroDiagonal(pc,tol);CHKERRQ(ierr);
72     }
73   ierr = PetscOptionsTail();CHKERRQ(ierr);
74   PetscFunctionReturn(0);
75 }
76 
77 #undef __FUNCT__
78 #define __FUNCT__ "PCView_LU"
79 static PetscErrorCode PCView_LU(PC pc,PetscViewer viewer)
80 {
81   PC_LU          *lu = (PC_LU*)pc->data;
82   PetscErrorCode ierr;
83   PetscBool      iascii;
84 
85   PetscFunctionBegin;
86   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
87   if (iascii) {
88     if (lu->inplace) {
89       ierr = PetscViewerASCIIPrintf(viewer,"  LU: in-place factorization\n");CHKERRQ(ierr);
90     } else {
91       ierr = PetscViewerASCIIPrintf(viewer,"  LU: out-of-place factorization\n");CHKERRQ(ierr);
92     }
93 
94     if (lu->reusefill)    {ierr = PetscViewerASCIIPrintf(viewer,"       Reusing fill from past factorization\n");CHKERRQ(ierr);}
95     if (lu->reuseordering) {ierr = PetscViewerASCIIPrintf(viewer,"       Reusing reordering from past factorization\n");CHKERRQ(ierr);}
96   }
97   ierr = PCView_Factor(pc,viewer);CHKERRQ(ierr);
98   PetscFunctionReturn(0);
99 }
100 
101 #undef __FUNCT__
102 #define __FUNCT__ "PCSetUp_LU"
103 static PetscErrorCode PCSetUp_LU(PC pc)
104 {
105   PetscErrorCode ierr;
106   PC_LU          *dir = (PC_LU*)pc->data;
107 
108   PetscFunctionBegin;
109   if (dir->reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->actualfill;
110 
111   if (dir->inplace) {
112     if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);}
113     ierr = ISDestroy(&dir->col);CHKERRQ(ierr);
114     ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr);
115     if (dir->row) {
116       ierr = PetscLogObjectParent(pc,dir->row);CHKERRQ(ierr);
117       ierr = PetscLogObjectParent(pc,dir->col);CHKERRQ(ierr);
118     }
119     ierr = MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
120     ((PC_Factor*)dir)->fact = pc->pmat;
121   } else {
122     MatInfo info;
123     if (!pc->setupcalled) {
124       ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr);
125       if (dir->nonzerosalongdiagonal) {
126         ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr);
127       }
128       if (dir->row) {
129         ierr = PetscLogObjectParent(pc,dir->row);CHKERRQ(ierr);
130         ierr = PetscLogObjectParent(pc,dir->col);CHKERRQ(ierr);
131       }
132       if (!((PC_Factor*)dir)->fact) {
133         ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr);
134       }
135       ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
136       ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr);
137       dir->actualfill = info.fill_ratio_needed;
138       ierr = PetscLogObjectParent(pc,((PC_Factor*)dir)->fact);CHKERRQ(ierr);
139     } else if (pc->flag != SAME_NONZERO_PATTERN) {
140       if (!dir->reuseordering) {
141         if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);}
142         ierr = ISDestroy(&dir->col);CHKERRQ(ierr);
143         ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr);
144         if (dir->nonzerosalongdiagonal) {
145           ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr);
146         }
147         if (dir->row) {
148           ierr = PetscLogObjectParent(pc,dir->row);CHKERRQ(ierr);
149           ierr = PetscLogObjectParent(pc,dir->col);CHKERRQ(ierr);
150         }
151       }
152       ierr = MatDestroy(&((PC_Factor*)dir)->fact);CHKERRQ(ierr);
153       ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr);
154       ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
155       ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr);
156       dir->actualfill = info.fill_ratio_needed;
157       ierr = PetscLogObjectParent(pc,((PC_Factor*)dir)->fact);CHKERRQ(ierr);
158     }
159     if ((!pc->setupcalled) || (pc->setupcalled && !pc->reuse)) {
160       ierr = MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
161     }
162   }
163   PetscFunctionReturn(0);
164 }
165 
166 #undef __FUNCT__
167 #define __FUNCT__ "PCReset_LU"
168 static PetscErrorCode PCReset_LU(PC pc)
169 {
170   PC_LU          *dir = (PC_LU*)pc->data;
171   PetscErrorCode ierr;
172 
173   PetscFunctionBegin;
174   if (!dir->inplace && ((PC_Factor*)dir)->fact) {ierr = MatDestroy(&((PC_Factor*)dir)->fact);CHKERRQ(ierr);}
175   if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);}
176   ierr = ISDestroy(&dir->col);CHKERRQ(ierr);
177   PetscFunctionReturn(0);
178 }
179 
180 #undef __FUNCT__
181 #define __FUNCT__ "PCDestroy_LU"
182 static PetscErrorCode PCDestroy_LU(PC pc)
183 {
184   PC_LU          *dir = (PC_LU*)pc->data;
185   PetscErrorCode ierr;
186 
187   PetscFunctionBegin;
188   ierr = PCReset_LU(pc);CHKERRQ(ierr);
189   ierr = PetscFree(((PC_Factor*)dir)->ordering);CHKERRQ(ierr);
190   ierr = PetscFree(((PC_Factor*)dir)->solvertype);CHKERRQ(ierr);
191   ierr = PetscFree(pc->data);CHKERRQ(ierr);
192   PetscFunctionReturn(0);
193 }
194 
195 #undef __FUNCT__
196 #define __FUNCT__ "PCApply_LU"
197 static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y)
198 {
199   PC_LU          *dir = (PC_LU*)pc->data;
200   PetscErrorCode ierr;
201 
202   PetscFunctionBegin;
203   if (dir->inplace) {ierr = MatSolve(pc->pmat,x,y);CHKERRQ(ierr);}
204   else              {ierr = MatSolve(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr);}
205   PetscFunctionReturn(0);
206 }
207 
208 #undef __FUNCT__
209 #define __FUNCT__ "PCApplyTranspose_LU"
210 static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y)
211 {
212   PC_LU          *dir = (PC_LU*)pc->data;
213   PetscErrorCode ierr;
214 
215   PetscFunctionBegin;
216   if (dir->inplace) {ierr = MatSolveTranspose(pc->pmat,x,y);CHKERRQ(ierr);}
217   else              {ierr = MatSolveTranspose(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr);}
218   PetscFunctionReturn(0);
219 }
220 
221 /* -----------------------------------------------------------------------------------*/
222 
223 EXTERN_C_BEGIN
224 #undef __FUNCT__
225 #define __FUNCT__ "PCFactorSetUseInPlace_LU"
226 PetscErrorCode  PCFactorSetUseInPlace_LU(PC pc)
227 {
228   PC_LU *dir = (PC_LU*)pc->data;
229 
230   PetscFunctionBegin;
231   dir->inplace = PETSC_TRUE;
232   PetscFunctionReturn(0);
233 }
234 EXTERN_C_END
235 
236 /* ------------------------------------------------------------------------ */
237 
238 /*MC
239    PCLU - Uses a direct solver, based on LU factorization, as a preconditioner
240 
241    Options Database Keys:
242 +  -pc_factor_reuse_ordering - Activate PCFactorSetReuseOrdering()
243 .  -pc_factor_mat_solver_package - Actives PCFactorSetMatSolverPackage() to choose the direct solver, like superlu
244 .  -pc_factor_reuse_fill - Activates PCFactorSetReuseFill()
245 .  -pc_factor_fill <fill> - Sets fill amount
246 .  -pc_factor_in_place - Activates in-place factorization
247 .  -pc_factor_mat_ordering_type <nd,rcm,...> - Sets ordering routine
248 .  -pc_factor_pivot_in_blocks <true,false> - allow pivoting within the small blocks during factorization (may increase
249                                          stability of factorization.
250 .  -pc_factor_shift_type <shifttype> - Sets shift type or PETSC_DECIDE for the default; use '-help' for a list of available types
251 .  -pc_factor_shift_amount <shiftamount> - Sets shift amount or PETSC_DECIDE for the default
252 -   -pc_factor_nonzeros_along_diagonal - permutes the rows and columns to try to put nonzero value along the
253         diagonal.
254 
255    Notes: Not all options work for all matrix formats
256           Run with -help to see additional options for particular matrix formats or factorization
257           algorithms
258 
259    Level: beginner
260 
261    Concepts: LU factorization, direct solver
262 
263    Notes: Usually this will compute an "exact" solution in one iteration and does
264           not need a Krylov method (i.e. you can use -ksp_type preonly, or
265           KSPSetType(ksp,KSPPREONLY) for the Krylov method
266 
267 .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC,
268            PCILU, PCCHOLESKY, PCICC, PCFactorSetReuseOrdering(), PCFactorSetReuseFill(), PCFactorGetMatrix(),
269            PCFactorSetFill(), PCFactorSetUseInPlace(), PCFactorSetMatOrderingType(), PCFactorSetColumnPivot(),
270            PCFactorSetPivotingInBlocks(),PCFactorSetShiftType(),PCFactorSetShiftAmount()
271            PCFactorReorderForNonzeroDiagonal()
272 M*/
273 
274 EXTERN_C_BEGIN
275 #undef __FUNCT__
276 #define __FUNCT__ "PCCreate_LU"
277 PetscErrorCode  PCCreate_LU(PC pc)
278 {
279   PetscErrorCode ierr;
280   PetscMPIInt    size;
281   PC_LU          *dir;
282 
283   PetscFunctionBegin;
284   ierr = PetscNewLog(pc,PC_LU,&dir);CHKERRQ(ierr);
285 
286   ierr = MatFactorInfoInitialize(&((PC_Factor*)dir)->info);CHKERRQ(ierr);
287   ((PC_Factor*)dir)->fact       = PETSC_NULL;
288   ((PC_Factor*)dir)->factortype = MAT_FACTOR_LU;
289   dir->inplace                  = PETSC_FALSE;
290   dir->nonzerosalongdiagonal    = PETSC_FALSE;
291 
292   ((PC_Factor*)dir)->info.fill           = 5.0;
293   ((PC_Factor*)dir)->info.dtcol          = 1.e-6; /* default to pivoting; this is only thing PETSc LU supports */
294   ((PC_Factor*)dir)->info.shifttype      = (PetscReal)MAT_SHIFT_NONE;
295   ((PC_Factor*)dir)->info.shiftamount    = 0.0;
296   ((PC_Factor*)dir)->info.zeropivot      = 100.0*PETSC_MACHINE_EPSILON;
297   ((PC_Factor*)dir)->info.pivotinblocks  = 1.0;
298   dir->col                 = 0;
299   dir->row                 = 0;
300 
301   ierr = PetscStrallocpy(MATSOLVERPETSC,&((PC_Factor*)dir)->solvertype);CHKERRQ(ierr); /* default SolverPackage */
302   ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr);
303   if (size == 1) {
304     ierr = PetscStrallocpy(MATORDERINGND,(char**)&((PC_Factor*)dir)->ordering);CHKERRQ(ierr);
305   } else {
306     ierr = PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)dir)->ordering);CHKERRQ(ierr);
307   }
308   dir->reusefill        = PETSC_FALSE;
309   dir->reuseordering    = PETSC_FALSE;
310   pc->data              = (void*)dir;
311 
312   pc->ops->reset             = PCReset_LU;
313   pc->ops->destroy           = PCDestroy_LU;
314   pc->ops->apply             = PCApply_LU;
315   pc->ops->applytranspose    = PCApplyTranspose_LU;
316   pc->ops->setup             = PCSetUp_LU;
317   pc->ops->setfromoptions    = PCSetFromOptions_LU;
318   pc->ops->view              = PCView_LU;
319   pc->ops->applyrichardson   = 0;
320   pc->ops->getfactoredmatrix = PCFactorGetMatrix_Factor;
321 
322   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetUpMatSolverPackage_C","PCFactorSetUpMatSolverPackage_Factor",
323                     PCFactorSetUpMatSolverPackage_Factor);CHKERRQ(ierr);
324   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorGetMatSolverPackage_C","PCFactorGetMatSolverPackage_Factor",
325                     PCFactorGetMatSolverPackage_Factor);CHKERRQ(ierr);
326   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetMatSolverPackage_C","PCFactorSetMatSolverPackage_Factor",
327                     PCFactorSetMatSolverPackage_Factor);CHKERRQ(ierr);
328   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetZeroPivot_C","PCFactorSetZeroPivot_Factor",
329                     PCFactorSetZeroPivot_Factor);CHKERRQ(ierr);
330   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetShiftType_C","PCFactorSetShiftType_Factor",
331                     PCFactorSetShiftType_Factor);CHKERRQ(ierr);
332   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetShiftAmount_C","PCFactorSetShiftAmount_Factor",
333                     PCFactorSetShiftAmount_Factor);CHKERRQ(ierr);
334   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetFill_C","PCFactorSetFill_Factor",
335                     PCFactorSetFill_Factor);CHKERRQ(ierr);
336   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetUseInPlace_C","PCFactorSetUseInPlace_LU",
337                     PCFactorSetUseInPlace_LU);CHKERRQ(ierr);
338   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetMatOrderingType_C","PCFactorSetMatOrderingType_Factor",
339                     PCFactorSetMatOrderingType_Factor);CHKERRQ(ierr);
340   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetReuseOrdering_C","PCFactorSetReuseOrdering_LU",
341                     PCFactorSetReuseOrdering_LU);CHKERRQ(ierr);
342   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetReuseFill_C","PCFactorSetReuseFill_LU",
343                     PCFactorSetReuseFill_LU);CHKERRQ(ierr);
344   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetColumnPivot_C","PCFactorSetColumnPivot_Factor",
345                     PCFactorSetColumnPivot_Factor);CHKERRQ(ierr);
346   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetPivotInBlocks_C","PCFactorSetPivotInBlocks_Factor",
347                     PCFactorSetPivotInBlocks_Factor);CHKERRQ(ierr);
348   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C","PCFactorReorderForNonzeroDiagonal_LU",
349                     PCFactorReorderForNonzeroDiagonal_LU);CHKERRQ(ierr);
350   PetscFunctionReturn(0);
351 }
352 EXTERN_C_END
353