xref: /petsc/src/ksp/pc/impls/factor/lu/lu.c (revision 829b6ff0376e8d5b8b7c6c54aef4e99b13aa00d1)
1 #define PETSCKSP_DLL
2 
3 /*
4    Defines a direct factorization preconditioner for any Mat implementation
5    Note: this need not be consided a preconditioner since it supplies
6          a direct solver.
7 */
8 
9 #include "../src/ksp/pc/impls/factor/lu/lu.h"  /*I "petscpc.h" I*/
10 
11 EXTERN_C_BEGIN
12 #undef __FUNCT__
13 #define __FUNCT__ "PCFactorReorderForNonzeroDiagonal_LU"
14 PetscErrorCode PETSCKSP_DLLEXPORT PCFactorReorderForNonzeroDiagonal_LU(PC pc,PetscReal z)
15 {
16   PC_LU *lu = (PC_LU*)pc->data;
17 
18   PetscFunctionBegin;
19   lu->nonzerosalongdiagonal = PETSC_TRUE;
20   if (z == PETSC_DECIDE) {
21     lu->nonzerosalongdiagonaltol = 1.e-10;
22   } else {
23     lu->nonzerosalongdiagonaltol = z;
24   }
25   PetscFunctionReturn(0);
26 }
27 EXTERN_C_END
28 
29 EXTERN_C_BEGIN
30 #undef __FUNCT__
31 #define __FUNCT__ "PCFactorSetReuseOrdering_LU"
32 PetscErrorCode PETSCKSP_DLLEXPORT PCFactorSetReuseOrdering_LU(PC pc,PetscTruth flag)
33 {
34   PC_LU *lu = (PC_LU*)pc->data;
35 
36   PetscFunctionBegin;
37   lu->reuseordering = flag;
38   PetscFunctionReturn(0);
39 }
40 EXTERN_C_END
41 
42 EXTERN_C_BEGIN
43 #undef __FUNCT__
44 #define __FUNCT__ "PCFactorSetReuseFill_LU"
45 PetscErrorCode PETSCKSP_DLLEXPORT PCFactorSetReuseFill_LU(PC pc,PetscTruth flag)
46 {
47   PC_LU *lu = (PC_LU*)pc->data;
48 
49   PetscFunctionBegin;
50   lu->reusefill = flag;
51   PetscFunctionReturn(0);
52 }
53 EXTERN_C_END
54 
55 #undef __FUNCT__
56 #define __FUNCT__ "PCSetFromOptions_LU"
57 static PetscErrorCode PCSetFromOptions_LU(PC pc)
58 {
59   PC_LU           *lu = (PC_LU*)pc->data;
60   PetscErrorCode  ierr;
61   PetscTruth      flg = PETSC_FALSE;
62   PetscReal       tol;
63 
64   PetscFunctionBegin;
65   ierr = PetscOptionsHead("LU options");CHKERRQ(ierr);
66     ierr = PCSetFromOptions_Factor(pc);CHKERRQ(ierr);
67 
68     ierr = PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);CHKERRQ(ierr);
69     if (flg) {
70       tol = PETSC_DECIDE;
71       ierr = PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,0);CHKERRQ(ierr);
72       ierr = PCFactorReorderForNonzeroDiagonal(pc,tol);CHKERRQ(ierr);
73     }
74   ierr = PetscOptionsTail();CHKERRQ(ierr);
75   PetscFunctionReturn(0);
76 }
77 
78 #undef __FUNCT__
79 #define __FUNCT__ "PCView_LU"
80 static PetscErrorCode PCView_LU(PC pc,PetscViewer viewer)
81 {
82   PC_LU          *lu = (PC_LU*)pc->data;
83   PetscErrorCode ierr;
84   PetscTruth     iascii,isstring;
85 
86   PetscFunctionBegin;
87   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
88   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_STRING,&isstring);CHKERRQ(ierr);
89   if (iascii) {
90 
91     if (lu->inplace) {ierr = PetscViewerASCIIPrintf(viewer,"  LU: in-place factorization\n");CHKERRQ(ierr);}
92     else             {ierr = PetscViewerASCIIPrintf(viewer,"  LU: out-of-place factorization\n");CHKERRQ(ierr);}
93     ierr = PetscViewerASCIIPrintf(viewer,"    matrix ordering: %s\n",((PC_Factor*)lu)->ordering);CHKERRQ(ierr);
94     ierr = PetscViewerASCIIPrintf(viewer,"  LU: tolerance for zero pivot %G\n",((PC_Factor*)lu)->info.zeropivot);CHKERRQ(ierr);
95     if (((PC_Factor*)lu)->info.shiftpd) {ierr = PetscViewerASCIIPrintf(viewer,"  LU: using Manteuffel shift\n");CHKERRQ(ierr);}
96     if (((PC_Factor*)lu)->fact) {
97       ierr = PetscViewerASCIIPrintf(viewer,"  LU: factor fill ratio needed %G\n",lu->actualfill);CHKERRQ(ierr);
98       ierr = PetscViewerASCIIPrintf(viewer,"       Factored matrix follows\n");CHKERRQ(ierr);
99       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
100       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
101       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
102       ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO);CHKERRQ(ierr);
103       ierr = MatView(((PC_Factor*)lu)->fact,viewer);CHKERRQ(ierr);
104       ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
105       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
106       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
107       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
108     }
109     if (lu->reusefill)    {ierr = PetscViewerASCIIPrintf(viewer,"       Reusing fill from past factorization\n");CHKERRQ(ierr);}
110     if (lu->reuseordering) {ierr = PetscViewerASCIIPrintf(viewer,"       Reusing reordering from past factorization\n");CHKERRQ(ierr);}
111   } else if (isstring) {
112     ierr = PetscViewerStringSPrintf(viewer," order=%s",((PC_Factor*)lu)->ordering);CHKERRQ(ierr);CHKERRQ(ierr);
113   } else {
114     SETERRQ1(PETSC_ERR_SUP,"Viewer type %s not supported for PCLU",((PetscObject)viewer)->type_name);
115   }
116   PetscFunctionReturn(0);
117 }
118 
119 #undef __FUNCT__
120 #define __FUNCT__ "PCSetUp_LU"
121 static PetscErrorCode PCSetUp_LU(PC pc)
122 {
123   PetscErrorCode ierr;
124   PC_LU          *dir = (PC_LU*)pc->data;
125 
126   PetscFunctionBegin;
127   if (dir->reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->actualfill;
128 
129   if (dir->inplace) {
130     if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(dir->row);CHKERRQ(ierr);}
131     if (dir->col) {ierr = ISDestroy(dir->col);CHKERRQ(ierr);}
132     ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr);
133     if (dir->row) {
134       ierr = PetscLogObjectParent(pc,dir->row);CHKERRQ(ierr);
135       ierr = PetscLogObjectParent(pc,dir->col);CHKERRQ(ierr);
136     }
137     ierr = MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
138     ((PC_Factor*)dir)->fact = pc->pmat;
139   } else {
140     MatInfo info;
141     if (!pc->setupcalled) {
142       ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr);
143       if (dir->nonzerosalongdiagonal) {
144         ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr);
145       }
146       if (dir->row) {
147         ierr = PetscLogObjectParent(pc,dir->row);CHKERRQ(ierr);
148         ierr = PetscLogObjectParent(pc,dir->col);CHKERRQ(ierr);
149       }
150       ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr);
151       ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
152       ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr);
153       dir->actualfill = info.fill_ratio_needed;
154       ierr = PetscLogObjectParent(pc,((PC_Factor*)dir)->fact);CHKERRQ(ierr);
155     } else if (pc->flag != SAME_NONZERO_PATTERN) {
156       if (!dir->reuseordering) {
157         if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(dir->row);CHKERRQ(ierr);}
158         if (dir->col) {ierr = ISDestroy(dir->col);CHKERRQ(ierr);}
159         ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr);
160         if (dir->nonzerosalongdiagonal) {
161           ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr);
162         }
163         if (dir->row) {
164           ierr = PetscLogObjectParent(pc,dir->row);CHKERRQ(ierr);
165           ierr = PetscLogObjectParent(pc,dir->col);CHKERRQ(ierr);
166         }
167       }
168       ierr = MatDestroy(((PC_Factor*)dir)->fact);CHKERRQ(ierr);
169       ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr);
170       ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
171       ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr);
172       dir->actualfill = info.fill_ratio_needed;
173       ierr = PetscLogObjectParent(pc,((PC_Factor*)dir)->fact);CHKERRQ(ierr);
174     }
175     ierr = MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info);CHKERRQ(ierr);
176   }
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   if (!dir->inplace && ((PC_Factor*)dir)->fact) {ierr = MatDestroy(((PC_Factor*)dir)->fact);CHKERRQ(ierr);}
189   if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(dir->row);CHKERRQ(ierr);}
190   if (dir->col) {ierr = ISDestroy(dir->col);CHKERRQ(ierr);}
191   ierr = PetscStrfree(((PC_Factor*)dir)->ordering);CHKERRQ(ierr);
192   ierr = PetscStrfree(((PC_Factor*)dir)->solvertype);CHKERRQ(ierr);
193   ierr = PetscFree(dir);CHKERRQ(ierr);
194   PetscFunctionReturn(0);
195 }
196 
197 #undef __FUNCT__
198 #define __FUNCT__ "PCApply_LU"
199 static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y)
200 {
201   PC_LU          *dir = (PC_LU*)pc->data;
202   PetscErrorCode ierr;
203 
204   PetscFunctionBegin;
205   if (dir->inplace) {ierr = MatSolve(pc->pmat,x,y);CHKERRQ(ierr);}
206   else              {ierr = MatSolve(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr);}
207   PetscFunctionReturn(0);
208 }
209 
210 #undef __FUNCT__
211 #define __FUNCT__ "PCApplyTranspose_LU"
212 static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y)
213 {
214   PC_LU          *dir = (PC_LU*)pc->data;
215   PetscErrorCode ierr;
216 
217   PetscFunctionBegin;
218   if (dir->inplace) {ierr = MatSolveTranspose(pc->pmat,x,y);CHKERRQ(ierr);}
219   else              {ierr = MatSolveTranspose(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr);}
220   PetscFunctionReturn(0);
221 }
222 
223 /* -----------------------------------------------------------------------------------*/
224 
225 EXTERN_C_BEGIN
226 #undef __FUNCT__
227 #define __FUNCT__ "PCFactorSetUseInPlace_LU"
228 PetscErrorCode PETSCKSP_DLLEXPORT PCFactorSetUseInPlace_LU(PC pc)
229 {
230   PC_LU *dir = (PC_LU*)pc->data;
231 
232   PetscFunctionBegin;
233   dir->inplace = PETSC_TRUE;
234   PetscFunctionReturn(0);
235 }
236 EXTERN_C_END
237 
238 /* ------------------------------------------------------------------------ */
239 
240 /*MC
241    PCLU - Uses a direct solver, based on LU factorization, as a preconditioner
242 
243    Options Database Keys:
244 +  -pc_factor_reuse_ordering - Activate PCFactorSetReuseOrdering()
245 .  -pc_factor_mat_solver_package - Actives PCFactorSetMatSolverPackage() to choose the direct solver, like spooles
246 .  -pc_factor_reuse_fill - Activates PCFactorSetReuseFill()
247 .  -pc_factor_fill <fill> - Sets fill amount
248 .  -pc_factor_in_place - Activates in-place factorization
249 .  -pc_factor_mat_ordering_type <nd,rcm,...> - Sets ordering routine
250 .  -pc_factor_pivot_in_blocks <true,false> - allow pivoting within the small blocks during factorization (may increase
251                                          stability of factorization.
252 .  -pc_factor_shift_nonzero <shift> - Sets shift amount or PETSC_DECIDE for the default
253 .  -pc_factor_shift_positive_definite [PETSC_TRUE/PETSC_FALSE] - Activate/Deactivate PCFactorSetShiftPd(); the value
254         is optional with PETSC_TRUE being the default
255 -   -pc_factor_nonzeros_along_diagonal - permutes the rows and columns to try to put nonzero value along the
256         diagonal.
257 
258    Notes: Not all options work for all matrix formats
259           Run with -help to see additional options for particular matrix formats or factorization
260           algorithms
261 
262    Level: beginner
263 
264    Concepts: LU factorization, direct solver
265 
266    Notes: Usually this will compute an "exact" solution in one iteration and does
267           not need a Krylov method (i.e. you can use -ksp_type preonly, or
268           KSPSetType(ksp,KSPPREONLY) for the Krylov method
269 
270 .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC,
271            PCILU, PCCHOLESKY, PCICC, PCFactorSetReuseOrdering(), PCFactorSetReuseFill(), PCFactorGetMatrix(),
272            PCFactorSetFill(), PCFactorSetUseInPlace(), PCFactorSetMatOrderingType(), PCFactorSetColumnPivot(),
273            PCFactorSetPivotingInBlocks(),PCFactorSetShiftNonzero(),PCFactorSetShiftPd(),PCFactorSetShiftInBlocks()
274            PCFactorReorderForNonzeroDiagonal()
275 M*/
276 
277 EXTERN_C_BEGIN
278 #undef __FUNCT__
279 #define __FUNCT__ "PCCreate_LU"
280 PetscErrorCode PETSCKSP_DLLEXPORT PCCreate_LU(PC pc)
281 {
282   PetscErrorCode ierr;
283   PetscMPIInt    size;
284   PC_LU          *dir;
285 
286   PetscFunctionBegin;
287   ierr = PetscNewLog(pc,PC_LU,&dir);CHKERRQ(ierr);
288 
289   ierr = MatFactorInfoInitialize(&((PC_Factor*)dir)->info);CHKERRQ(ierr);
290   ((PC_Factor*)dir)->fact                  = 0;
291   dir->inplace               = PETSC_FALSE;
292   dir->nonzerosalongdiagonal = PETSC_FALSE;
293 
294   ((PC_Factor*)dir)->info.fill           = 5.0;
295   ((PC_Factor*)dir)->info.dtcol          = 1.e-6; /* default to pivoting; this is only thing PETSc LU supports */
296   ((PC_Factor*)dir)->info.shiftnz        = 0.0;
297   ((PC_Factor*)dir)->info.zeropivot      = 1.e-12;
298   ((PC_Factor*)dir)->info.pivotinblocks  = 1.0;
299   ((PC_Factor*)dir)->info.shiftpd        = 0.0; /* false */
300   dir->col                 = 0;
301   dir->row                 = 0;
302 
303   ierr = PetscStrallocpy(MAT_SOLVER_PETSC,&((PC_Factor*)dir)->solvertype);CHKERRQ(ierr);
304   ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr);
305   if (size == 1) {
306     ierr = PetscStrallocpy(MATORDERING_ND,&((PC_Factor*)dir)->ordering);CHKERRQ(ierr);
307   } else {
308     ierr = PetscStrallocpy(MATORDERING_NATURAL,&((PC_Factor*)dir)->ordering);CHKERRQ(ierr);
309   }
310   dir->reusefill        = PETSC_FALSE;
311   dir->reuseordering    = PETSC_FALSE;
312   pc->data              = (void*)dir;
313 
314   pc->ops->destroy           = PCDestroy_LU;
315   pc->ops->apply             = PCApply_LU;
316   pc->ops->applytranspose    = PCApplyTranspose_LU;
317   pc->ops->setup             = PCSetUp_LU;
318   pc->ops->setfromoptions    = PCSetFromOptions_LU;
319   pc->ops->view              = PCView_LU;
320   pc->ops->applyrichardson   = 0;
321   pc->ops->getfactoredmatrix = PCFactorGetMatrix_Factor;
322 
323   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorGetMatSolverPackage_C","PCFactorGetMatSolverPackage_Factor",
324                     PCFactorGetMatSolverPackage_Factor);CHKERRQ(ierr);
325   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetMatSolverPackage_C","PCFactorSetMatSolverPackage_Factor",
326                     PCFactorSetMatSolverPackage_Factor);CHKERRQ(ierr);
327   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetZeroPivot_C","PCFactorSetZeroPivot_Factor",
328                     PCFactorSetZeroPivot_Factor);CHKERRQ(ierr);
329   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetShiftNonzero_C","PCFactorSetShiftNonzero_Factor",
330                     PCFactorSetShiftNonzero_Factor);CHKERRQ(ierr);
331   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetShiftPd_C","PCFactorSetShiftPd_Factor",
332                     PCFactorSetShiftPd_Factor);CHKERRQ(ierr);
333   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetShiftInBlocks_C","PCFactorSetShiftInBlocks_Factor",
334                     PCFactorSetShiftInBlocks_Factor);CHKERRQ(ierr);
335 
336   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetFill_C","PCFactorSetFill_Factor",
337                     PCFactorSetFill_Factor);CHKERRQ(ierr);
338   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetUseInPlace_C","PCFactorSetUseInPlace_LU",
339                     PCFactorSetUseInPlace_LU);CHKERRQ(ierr);
340   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetMatOrderingType_C","PCFactorSetMatOrderingType_Factor",
341                     PCFactorSetMatOrderingType_Factor);CHKERRQ(ierr);
342   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetReuseOrdering_C","PCFactorSetReuseOrdering_LU",
343                     PCFactorSetReuseOrdering_LU);CHKERRQ(ierr);
344   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetReuseFill_C","PCFactorSetReuseFill_LU",
345                     PCFactorSetReuseFill_LU);CHKERRQ(ierr);
346   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetColumnPivot_C","PCFactorSetColumnPivot_Factor",
347                     PCFactorSetColumnPivot_Factor);CHKERRQ(ierr);
348   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorSetPivotInBlocks_C","PCFactorSetPivotInBlocks_Factor",
349                     PCFactorSetPivotInBlocks_Factor);CHKERRQ(ierr);
350   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C","PCFactorReorderForNonzeroDiagonal_LU",
351                     PCFactorReorderForNonzeroDiagonal_LU);CHKERRQ(ierr);
352   PetscFunctionReturn(0);
353 }
354 EXTERN_C_END
355