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 PetscErrorCode PCFactorReorderForNonzeroDiagonal_LU(PC pc,PetscReal z) 11 { 12 PC_LU *lu = (PC_LU*)pc->data; 13 14 PetscFunctionBegin; 15 lu->nonzerosalongdiagonal = PETSC_TRUE; 16 if (z == PETSC_DECIDE) lu->nonzerosalongdiagonaltol = 1.e-10; 17 else lu->nonzerosalongdiagonaltol = z; 18 PetscFunctionReturn(0); 19 } 20 21 static PetscErrorCode PCSetFromOptions_LU(PetscOptionItems *PetscOptionsObject,PC pc) 22 { 23 PC_LU *lu = (PC_LU*)pc->data; 24 PetscBool flg = PETSC_FALSE; 25 PetscReal tol; 26 27 PetscFunctionBegin; 28 PetscCall(PetscOptionsHead(PetscOptionsObject,"LU options")); 29 PetscCall(PCSetFromOptions_Factor(PetscOptionsObject,pc)); 30 31 PetscCall(PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg)); 32 if (flg) { 33 tol = PETSC_DECIDE; 34 PetscCall(PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,NULL)); 35 PetscCall(PCFactorReorderForNonzeroDiagonal(pc,tol)); 36 } 37 PetscCall(PetscOptionsTail()); 38 PetscFunctionReturn(0); 39 } 40 41 static PetscErrorCode PCSetUp_LU(PC pc) 42 { 43 PC_LU *dir = (PC_LU*)pc->data; 44 MatSolverType stype; 45 MatFactorError err; 46 47 PetscFunctionBegin; 48 pc->failedreason = PC_NOERROR; 49 if (dir->hdr.reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->hdr.actualfill; 50 51 PetscCall(MatSetErrorIfFailure(pc->pmat,pc->erroriffailure)); 52 if (dir->hdr.inplace) { 53 MatFactorType ftype; 54 55 PetscCall(MatGetFactorType(pc->pmat, &ftype)); 56 if (ftype == MAT_FACTOR_NONE) { 57 if (dir->row && dir->col && dir->row != dir->col) PetscCall(ISDestroy(&dir->row)); 58 PetscCall(ISDestroy(&dir->col)); 59 /* This should only get the ordering if needed, but since MatGetFactor() is not called we can't know if it is needed */ 60 PetscCall(PCFactorSetDefaultOrdering_Factor(pc)); 61 PetscCall(MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col)); 62 if (dir->row) { 63 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row)); 64 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col)); 65 } 66 PetscCall(MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info)); 67 PetscCall(MatFactorGetError(pc->pmat,&err)); 68 if (err) { /* Factor() fails */ 69 pc->failedreason = (PCFailedReason)err; 70 PetscFunctionReturn(0); 71 } 72 } 73 ((PC_Factor*)dir)->fact = pc->pmat; 74 } else { 75 MatInfo info; 76 77 if (!pc->setupcalled) { 78 PetscBool canuseordering; 79 if (!((PC_Factor*)dir)->fact) { 80 PetscCall(MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact)); 81 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact)); 82 } 83 PetscCall(MatFactorGetCanUseOrdering(((PC_Factor*)dir)->fact,&canuseordering)); 84 if (canuseordering) { 85 PetscCall(PCFactorSetDefaultOrdering_Factor(pc)); 86 PetscCall(MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col)); 87 if (dir->nonzerosalongdiagonal) { 88 PetscCall(MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col)); 89 } 90 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row)); 91 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col)); 92 } 93 PetscCall(MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info)); 94 PetscCall(MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info)); 95 dir->hdr.actualfill = info.fill_ratio_needed; 96 } else if (pc->flag != SAME_NONZERO_PATTERN) { 97 PetscBool canuseordering; 98 if (!dir->hdr.reuseordering) { 99 PetscCall(MatDestroy(&((PC_Factor*)dir)->fact)); 100 PetscCall(MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact)); 101 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact)); 102 PetscCall(MatFactorGetCanUseOrdering(((PC_Factor*)dir)->fact,&canuseordering)); 103 if (canuseordering) { 104 if (dir->row && dir->col && dir->row != dir->col) PetscCall(ISDestroy(&dir->row)); 105 PetscCall(ISDestroy(&dir->col)); 106 PetscCall(PCFactorSetDefaultOrdering_Factor(pc)); 107 PetscCall(MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col)); 108 if (dir->nonzerosalongdiagonal) { 109 PetscCall(MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col)); 110 } 111 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row)); 112 PetscCall(PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col)); 113 } 114 } 115 PetscCall(MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info)); 116 PetscCall(MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info)); 117 dir->hdr.actualfill = info.fill_ratio_needed; 118 } else { 119 PetscCall(MatFactorGetError(((PC_Factor*)dir)->fact,&err)); 120 if (err == MAT_FACTOR_NUMERIC_ZEROPIVOT) { 121 PetscCall(MatFactorClearError(((PC_Factor*)dir)->fact)); 122 pc->failedreason = PC_NOERROR; 123 } 124 } 125 PetscCall(MatFactorGetError(((PC_Factor*)dir)->fact,&err)); 126 if (err) { /* FactorSymbolic() fails */ 127 pc->failedreason = (PCFailedReason)err; 128 PetscFunctionReturn(0); 129 } 130 131 PetscCall(MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info)); 132 PetscCall(MatFactorGetError(((PC_Factor*)dir)->fact,&err)); 133 if (err) { /* FactorNumeric() fails */ 134 pc->failedreason = (PCFailedReason)err; 135 } 136 137 } 138 139 PetscCall(PCFactorGetMatSolverType(pc,&stype)); 140 if (!stype) { 141 MatSolverType solverpackage; 142 PetscCall(MatFactorGetSolverType(((PC_Factor*)dir)->fact,&solverpackage)); 143 PetscCall(PCFactorSetMatSolverType(pc,solverpackage)); 144 } 145 PetscFunctionReturn(0); 146 } 147 148 static PetscErrorCode PCReset_LU(PC pc) 149 { 150 PC_LU *dir = (PC_LU*)pc->data; 151 152 PetscFunctionBegin; 153 if (!dir->hdr.inplace && ((PC_Factor*)dir)->fact) PetscCall(MatDestroy(&((PC_Factor*)dir)->fact)); 154 if (dir->row && dir->col && dir->row != dir->col) PetscCall(ISDestroy(&dir->row)); 155 PetscCall(ISDestroy(&dir->col)); 156 PetscFunctionReturn(0); 157 } 158 159 static PetscErrorCode PCDestroy_LU(PC pc) 160 { 161 PC_LU *dir = (PC_LU*)pc->data; 162 163 PetscFunctionBegin; 164 PetscCall(PCReset_LU(pc)); 165 PetscCall(PetscFree(((PC_Factor*)dir)->ordering)); 166 PetscCall(PetscFree(((PC_Factor*)dir)->solvertype)); 167 PetscCall(PetscFree(pc->data)); 168 PetscFunctionReturn(0); 169 } 170 171 static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y) 172 { 173 PC_LU *dir = (PC_LU*)pc->data; 174 175 PetscFunctionBegin; 176 if (dir->hdr.inplace) { 177 PetscCall(MatSolve(pc->pmat,x,y)); 178 } else { 179 PetscCall(MatSolve(((PC_Factor*)dir)->fact,x,y)); 180 } 181 PetscFunctionReturn(0); 182 } 183 184 static PetscErrorCode PCMatApply_LU(PC pc,Mat X,Mat Y) 185 { 186 PC_LU *dir = (PC_LU*)pc->data; 187 188 PetscFunctionBegin; 189 if (dir->hdr.inplace) { 190 PetscCall(MatMatSolve(pc->pmat,X,Y)); 191 } else { 192 PetscCall(MatMatSolve(((PC_Factor*)dir)->fact,X,Y)); 193 } 194 PetscFunctionReturn(0); 195 } 196 197 static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y) 198 { 199 PC_LU *dir = (PC_LU*)pc->data; 200 201 PetscFunctionBegin; 202 if (dir->hdr.inplace) { 203 PetscCall(MatSolveTranspose(pc->pmat,x,y)); 204 } else { 205 PetscCall(MatSolveTranspose(((PC_Factor*)dir)->fact,x,y)); 206 } 207 PetscFunctionReturn(0); 208 } 209 210 /* -----------------------------------------------------------------------------------*/ 211 212 /*MC 213 PCLU - Uses a direct solver, based on LU factorization, as a preconditioner 214 215 Options Database Keys: 216 + -pc_factor_reuse_ordering - Activate PCFactorSetReuseOrdering() 217 . -pc_factor_mat_solver_type - Actives PCFactorSetMatSolverType() to choose the direct solver, like superlu 218 . -pc_factor_reuse_fill - Activates PCFactorSetReuseFill() 219 . -pc_factor_fill <fill> - Sets fill amount 220 . -pc_factor_in_place - Activates in-place factorization 221 . -pc_factor_mat_ordering_type <nd,rcm,...> - Sets ordering routine 222 . -pc_factor_pivot_in_blocks <true,false> - allow pivoting within the small blocks during factorization (may increase 223 stability of factorization. 224 . -pc_factor_shift_type <shifttype> - Sets shift type or PETSC_DECIDE for the default; use '-help' for a list of available types 225 . -pc_factor_shift_amount <shiftamount> - Sets shift amount or PETSC_DECIDE for the default 226 - -pc_factor_nonzeros_along_diagonal - permutes the rows and columns to try to put nonzero value along the 227 diagonal. 228 229 Notes: 230 Not all options work for all matrix formats 231 Run with -help to see additional options for particular matrix formats or factorization 232 algorithms 233 234 Level: beginner 235 236 Notes: 237 Usually this will compute an "exact" solution in one iteration and does 238 not need a Krylov method (i.e. you can use -ksp_type preonly, or 239 KSPSetType(ksp,KSPPREONLY) for the Krylov method 240 241 .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, 242 PCILU, PCCHOLESKY, PCICC, PCFactorSetReuseOrdering(), PCFactorSetReuseFill(), PCFactorGetMatrix(), 243 PCFactorSetFill(), PCFactorSetUseInPlace(), PCFactorSetMatOrderingType(), PCFactorSetColumnPivot(), 244 PCFactorSetPivotInBlocks(),PCFactorSetShiftType(),PCFactorSetShiftAmount() 245 PCFactorReorderForNonzeroDiagonal() 246 M*/ 247 248 PETSC_EXTERN PetscErrorCode PCCreate_LU(PC pc) 249 { 250 PC_LU *dir; 251 252 PetscFunctionBegin; 253 PetscCall(PetscNewLog(pc,&dir)); 254 pc->data = (void*)dir; 255 PetscCall(PCFactorInitialize(pc,MAT_FACTOR_LU)); 256 dir->nonzerosalongdiagonal = PETSC_FALSE; 257 258 ((PC_Factor*)dir)->info.fill = 5.0; 259 ((PC_Factor*)dir)->info.dtcol = 1.e-6; /* default to pivoting; this is only thing PETSc LU supports */ 260 ((PC_Factor*)dir)->info.shifttype = (PetscReal)MAT_SHIFT_NONE; 261 dir->col = NULL; 262 dir->row = NULL; 263 264 pc->ops->reset = PCReset_LU; 265 pc->ops->destroy = PCDestroy_LU; 266 pc->ops->apply = PCApply_LU; 267 pc->ops->matapply = PCMatApply_LU; 268 pc->ops->applytranspose = PCApplyTranspose_LU; 269 pc->ops->setup = PCSetUp_LU; 270 pc->ops->setfromoptions = PCSetFromOptions_LU; 271 pc->ops->view = PCView_Factor; 272 pc->ops->applyrichardson = NULL; 273 PetscCall(PetscObjectComposeFunction((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C",PCFactorReorderForNonzeroDiagonal_LU)); 274 PetscFunctionReturn(0); 275 } 276