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 PetscErrorCode ierr; 25 PetscBool flg = PETSC_FALSE; 26 PetscReal tol; 27 28 PetscFunctionBegin; 29 ierr = PetscOptionsHead(PetscOptionsObject,"LU options");CHKERRQ(ierr); 30 ierr = PCSetFromOptions_Factor(PetscOptionsObject,pc);CHKERRQ(ierr); 31 32 ierr = PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);CHKERRQ(ierr); 33 if (flg) { 34 tol = PETSC_DECIDE; 35 ierr = PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,NULL);CHKERRQ(ierr); 36 ierr = PCFactorReorderForNonzeroDiagonal(pc,tol);CHKERRQ(ierr); 37 } 38 ierr = PetscOptionsTail();CHKERRQ(ierr); 39 PetscFunctionReturn(0); 40 } 41 42 static PetscErrorCode PCSetUp_LU(PC pc) 43 { 44 PetscErrorCode ierr; 45 PC_LU *dir = (PC_LU*)pc->data; 46 MatSolverType stype; 47 MatFactorError err; 48 49 PetscFunctionBegin; 50 pc->failedreason = PC_NOERROR; 51 if (dir->hdr.reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->hdr.actualfill; 52 53 ierr = MatSetErrorIfFailure(pc->pmat,pc->erroriffailure);CHKERRQ(ierr); 54 if (dir->hdr.inplace) { 55 MatFactorType ftype; 56 57 ierr = MatGetFactorType(pc->pmat, &ftype);CHKERRQ(ierr); 58 if (ftype == MAT_FACTOR_NONE) { 59 if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);} 60 ierr = ISDestroy(&dir->col);CHKERRQ(ierr); 61 /* This should only get the ordering if needed, but since MatGetFactor() is not called we can't know if it is needed */ 62 ierr = PCFactorSetDefaultOrdering_Factor(pc);CHKERRQ(ierr); 63 ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr); 64 if (dir->row) { 65 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);CHKERRQ(ierr); 66 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);CHKERRQ(ierr); 67 } 68 ierr = MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 69 ierr = MatFactorGetError(pc->pmat,&err);CHKERRQ(ierr); 70 if (err) { /* Factor() fails */ 71 pc->failedreason = (PCFailedReason)err; 72 PetscFunctionReturn(0); 73 } 74 } 75 ((PC_Factor*)dir)->fact = pc->pmat; 76 } else { 77 MatInfo info; 78 79 if (!pc->setupcalled) { 80 PetscBool canuseordering; 81 if (!((PC_Factor*)dir)->fact) { 82 ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr); 83 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact);CHKERRQ(ierr); 84 } 85 ierr = MatFactorGetCanUseOrdering(((PC_Factor*)dir)->fact,&canuseordering);CHKERRQ(ierr); 86 if (canuseordering) { 87 ierr = PCFactorSetDefaultOrdering_Factor(pc);CHKERRQ(ierr); 88 ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr); 89 if (dir->nonzerosalongdiagonal) { 90 ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr); 91 } 92 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);CHKERRQ(ierr); 93 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);CHKERRQ(ierr); 94 } 95 ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 96 ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr); 97 dir->hdr.actualfill = info.fill_ratio_needed; 98 } else if (pc->flag != SAME_NONZERO_PATTERN) { 99 PetscBool canuseordering; 100 if (!dir->hdr.reuseordering) { 101 ierr = MatDestroy(&((PC_Factor*)dir)->fact);CHKERRQ(ierr); 102 ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr); 103 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact);CHKERRQ(ierr); 104 ierr = MatFactorGetCanUseOrdering(((PC_Factor*)dir)->fact,&canuseordering);CHKERRQ(ierr); 105 if (canuseordering) { 106 if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);} 107 ierr = ISDestroy(&dir->col);CHKERRQ(ierr); 108 ierr = PCFactorSetDefaultOrdering_Factor(pc);CHKERRQ(ierr); 109 ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr); 110 if (dir->nonzerosalongdiagonal) { 111 ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr); 112 } 113 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);CHKERRQ(ierr); 114 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);CHKERRQ(ierr); 115 } 116 } 117 ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 118 ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr); 119 dir->hdr.actualfill = info.fill_ratio_needed; 120 } else { 121 ierr = MatFactorGetError(((PC_Factor*)dir)->fact,&err);CHKERRQ(ierr); 122 if (err == MAT_FACTOR_NUMERIC_ZEROPIVOT) { 123 ierr = MatFactorClearError(((PC_Factor*)dir)->fact);CHKERRQ(ierr); 124 pc->failedreason = PC_NOERROR; 125 } 126 } 127 ierr = MatFactorGetError(((PC_Factor*)dir)->fact,&err);CHKERRQ(ierr); 128 if (err) { /* FactorSymbolic() fails */ 129 pc->failedreason = (PCFailedReason)err; 130 PetscFunctionReturn(0); 131 } 132 133 ierr = MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 134 ierr = MatFactorGetError(((PC_Factor*)dir)->fact,&err);CHKERRQ(ierr); 135 if (err) { /* FactorNumeric() fails */ 136 pc->failedreason = (PCFailedReason)err; 137 } 138 139 } 140 141 ierr = PCFactorGetMatSolverType(pc,&stype);CHKERRQ(ierr); 142 if (!stype) { 143 MatSolverType solverpackage; 144 ierr = MatFactorGetSolverType(((PC_Factor*)dir)->fact,&solverpackage);CHKERRQ(ierr); 145 ierr = PCFactorSetMatSolverType(pc,solverpackage);CHKERRQ(ierr); 146 } 147 PetscFunctionReturn(0); 148 } 149 150 static PetscErrorCode PCReset_LU(PC pc) 151 { 152 PC_LU *dir = (PC_LU*)pc->data; 153 PetscErrorCode ierr; 154 155 PetscFunctionBegin; 156 if (!dir->hdr.inplace && ((PC_Factor*)dir)->fact) {ierr = MatDestroy(&((PC_Factor*)dir)->fact);CHKERRQ(ierr);} 157 if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);} 158 ierr = ISDestroy(&dir->col);CHKERRQ(ierr); 159 PetscFunctionReturn(0); 160 } 161 162 static PetscErrorCode PCDestroy_LU(PC pc) 163 { 164 PC_LU *dir = (PC_LU*)pc->data; 165 PetscErrorCode ierr; 166 167 PetscFunctionBegin; 168 ierr = PCReset_LU(pc);CHKERRQ(ierr); 169 ierr = PetscFree(((PC_Factor*)dir)->ordering);CHKERRQ(ierr); 170 ierr = PetscFree(((PC_Factor*)dir)->solvertype);CHKERRQ(ierr); 171 ierr = PetscFree(pc->data);CHKERRQ(ierr); 172 PetscFunctionReturn(0); 173 } 174 175 static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y) 176 { 177 PC_LU *dir = (PC_LU*)pc->data; 178 PetscErrorCode ierr; 179 180 PetscFunctionBegin; 181 if (dir->hdr.inplace) { 182 ierr = MatSolve(pc->pmat,x,y);CHKERRQ(ierr); 183 } else { 184 ierr = MatSolve(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr); 185 } 186 PetscFunctionReturn(0); 187 } 188 189 static PetscErrorCode PCMatApply_LU(PC pc,Mat X,Mat Y) 190 { 191 PC_LU *dir = (PC_LU*)pc->data; 192 PetscErrorCode ierr; 193 194 PetscFunctionBegin; 195 if (dir->hdr.inplace) { 196 ierr = MatMatSolve(pc->pmat,X,Y);CHKERRQ(ierr); 197 } else { 198 ierr = MatMatSolve(((PC_Factor*)dir)->fact,X,Y);CHKERRQ(ierr); 199 } 200 PetscFunctionReturn(0); 201 } 202 203 static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y) 204 { 205 PC_LU *dir = (PC_LU*)pc->data; 206 PetscErrorCode ierr; 207 208 PetscFunctionBegin; 209 if (dir->hdr.inplace) { 210 ierr = MatSolveTranspose(pc->pmat,x,y);CHKERRQ(ierr); 211 } else { 212 ierr = MatSolveTranspose(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr); 213 } 214 PetscFunctionReturn(0); 215 } 216 217 /* -----------------------------------------------------------------------------------*/ 218 219 /*MC 220 PCLU - Uses a direct solver, based on LU factorization, as a preconditioner 221 222 Options Database Keys: 223 + -pc_factor_reuse_ordering - Activate PCFactorSetReuseOrdering() 224 . -pc_factor_mat_solver_type - Actives PCFactorSetMatSolverType() to choose the direct solver, like superlu 225 . -pc_factor_reuse_fill - Activates PCFactorSetReuseFill() 226 . -pc_factor_fill <fill> - Sets fill amount 227 . -pc_factor_in_place - Activates in-place factorization 228 . -pc_factor_mat_ordering_type <nd,rcm,...> - Sets ordering routine 229 . -pc_factor_pivot_in_blocks <true,false> - allow pivoting within the small blocks during factorization (may increase 230 stability of factorization. 231 . -pc_factor_shift_type <shifttype> - Sets shift type or PETSC_DECIDE for the default; use '-help' for a list of available types 232 . -pc_factor_shift_amount <shiftamount> - Sets shift amount or PETSC_DECIDE for the default 233 - -pc_factor_nonzeros_along_diagonal - permutes the rows and columns to try to put nonzero value along the 234 diagonal. 235 236 Notes: 237 Not all options work for all matrix formats 238 Run with -help to see additional options for particular matrix formats or factorization 239 algorithms 240 241 Level: beginner 242 243 Notes: 244 Usually this will compute an "exact" solution in one iteration and does 245 not need a Krylov method (i.e. you can use -ksp_type preonly, or 246 KSPSetType(ksp,KSPPREONLY) for the Krylov method 247 248 .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, 249 PCILU, PCCHOLESKY, PCICC, PCFactorSetReuseOrdering(), PCFactorSetReuseFill(), PCFactorGetMatrix(), 250 PCFactorSetFill(), PCFactorSetUseInPlace(), PCFactorSetMatOrderingType(), PCFactorSetColumnPivot(), 251 PCFactorSetPivotInBlocks(),PCFactorSetShiftType(),PCFactorSetShiftAmount() 252 PCFactorReorderForNonzeroDiagonal() 253 M*/ 254 255 PETSC_EXTERN PetscErrorCode PCCreate_LU(PC pc) 256 { 257 PetscErrorCode ierr; 258 PC_LU *dir; 259 260 PetscFunctionBegin; 261 ierr = PetscNewLog(pc,&dir);CHKERRQ(ierr); 262 pc->data = (void*)dir; 263 ierr = PCFactorInitialize(pc,MAT_FACTOR_LU);CHKERRQ(ierr); 264 dir->nonzerosalongdiagonal = PETSC_FALSE; 265 266 ((PC_Factor*)dir)->info.fill = 5.0; 267 ((PC_Factor*)dir)->info.dtcol = 1.e-6; /* default to pivoting; this is only thing PETSc LU supports */ 268 ((PC_Factor*)dir)->info.shifttype = (PetscReal)MAT_SHIFT_NONE; 269 dir->col = NULL; 270 dir->row = NULL; 271 272 pc->ops->reset = PCReset_LU; 273 pc->ops->destroy = PCDestroy_LU; 274 pc->ops->apply = PCApply_LU; 275 pc->ops->matapply = PCMatApply_LU; 276 pc->ops->applytranspose = PCApplyTranspose_LU; 277 pc->ops->setup = PCSetUp_LU; 278 pc->ops->setfromoptions = PCSetFromOptions_LU; 279 pc->ops->view = PCView_Factor; 280 pc->ops->applyrichardson = NULL; 281 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C",PCFactorReorderForNonzeroDiagonal_LU);CHKERRQ(ierr); 282 PetscFunctionReturn(0); 283 } 284