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 11 PetscErrorCode PCFactorReorderForNonzeroDiagonal_LU(PC pc,PetscReal z) 12 { 13 PC_LU *lu = (PC_LU*)pc->data; 14 15 PetscFunctionBegin; 16 lu->nonzerosalongdiagonal = PETSC_TRUE; 17 if (z == PETSC_DECIDE) lu->nonzerosalongdiagonaltol = 1.e-10; 18 else lu->nonzerosalongdiagonaltol = z; 19 PetscFunctionReturn(0); 20 } 21 22 static PetscErrorCode PCSetFromOptions_LU(PetscOptionItems *PetscOptionsObject,PC pc) 23 { 24 PC_LU *lu = (PC_LU*)pc->data; 25 PetscErrorCode ierr; 26 PetscBool flg = PETSC_FALSE; 27 PetscReal tol; 28 29 PetscFunctionBegin; 30 ierr = PetscOptionsHead(PetscOptionsObject,"LU options");CHKERRQ(ierr); 31 ierr = PCSetFromOptions_Factor(PetscOptionsObject,pc);CHKERRQ(ierr); 32 33 ierr = PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);CHKERRQ(ierr); 34 if (flg) { 35 tol = PETSC_DECIDE; 36 ierr = PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",lu->nonzerosalongdiagonaltol,&tol,NULL);CHKERRQ(ierr); 37 ierr = PCFactorReorderForNonzeroDiagonal(pc,tol);CHKERRQ(ierr); 38 } 39 ierr = PetscOptionsTail();CHKERRQ(ierr); 40 PetscFunctionReturn(0); 41 } 42 43 static PetscErrorCode PCSetUp_LU(PC pc) 44 { 45 PetscErrorCode ierr; 46 PC_LU *dir = (PC_LU*)pc->data; 47 MatSolverType stype; 48 MatFactorError err; 49 50 PetscFunctionBegin; 51 pc->failedreason = PC_NOERROR; 52 if (dir->hdr.reusefill && pc->setupcalled) ((PC_Factor*)dir)->info.fill = dir->hdr.actualfill; 53 54 ierr = MatSetErrorIfFailure(pc->pmat,pc->erroriffailure);CHKERRQ(ierr); 55 if (dir->hdr.inplace) { 56 MatFactorType ftype; 57 58 ierr = MatGetFactorType(pc->pmat, &ftype);CHKERRQ(ierr); 59 if (ftype == MAT_FACTOR_NONE) { 60 if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);} 61 ierr = ISDestroy(&dir->col);CHKERRQ(ierr); 62 ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr); 63 if (dir->row) { 64 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);CHKERRQ(ierr); 65 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);CHKERRQ(ierr); 66 } 67 ierr = MatLUFactor(pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 68 ierr = MatFactorGetError(pc->pmat,&err);CHKERRQ(ierr); 69 if (err) { /* Factor() fails */ 70 pc->failedreason = (PCFailedReason)err; 71 PetscFunctionReturn(0); 72 } 73 } 74 ((PC_Factor*)dir)->fact = pc->pmat; 75 } else { 76 MatInfo info; 77 78 if (!pc->setupcalled) { 79 ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr); 80 if (dir->nonzerosalongdiagonal) { 81 ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr); 82 } 83 if (dir->row) { 84 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);CHKERRQ(ierr); 85 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);CHKERRQ(ierr); 86 } 87 if (!((PC_Factor*)dir)->fact) { 88 ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr); 89 } 90 ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 91 ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr); 92 dir->hdr.actualfill = info.fill_ratio_needed; 93 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact);CHKERRQ(ierr); 94 } else if (pc->flag != SAME_NONZERO_PATTERN) { 95 if (!dir->hdr.reuseordering) { 96 if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);} 97 ierr = ISDestroy(&dir->col);CHKERRQ(ierr); 98 ierr = MatGetOrdering(pc->pmat,((PC_Factor*)dir)->ordering,&dir->row,&dir->col);CHKERRQ(ierr); 99 if (dir->nonzerosalongdiagonal) { 100 ierr = MatReorderForNonzeroDiagonal(pc->pmat,dir->nonzerosalongdiagonaltol,dir->row,dir->col);CHKERRQ(ierr); 101 } 102 if (dir->row) { 103 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->row);CHKERRQ(ierr); 104 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)dir->col);CHKERRQ(ierr); 105 } 106 } 107 ierr = MatDestroy(&((PC_Factor*)dir)->fact);CHKERRQ(ierr); 108 ierr = MatGetFactor(pc->pmat,((PC_Factor*)dir)->solvertype,MAT_FACTOR_LU,&((PC_Factor*)dir)->fact);CHKERRQ(ierr); 109 ierr = MatLUFactorSymbolic(((PC_Factor*)dir)->fact,pc->pmat,dir->row,dir->col,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 110 ierr = MatGetInfo(((PC_Factor*)dir)->fact,MAT_LOCAL,&info);CHKERRQ(ierr); 111 dir->hdr.actualfill = info.fill_ratio_needed; 112 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)dir)->fact);CHKERRQ(ierr); 113 } else { 114 ierr = MatFactorGetError(((PC_Factor*)dir)->fact,&err);CHKERRQ(ierr); 115 if (err == MAT_FACTOR_NUMERIC_ZEROPIVOT) { 116 ierr = MatFactorClearError(((PC_Factor*)dir)->fact);CHKERRQ(ierr); 117 pc->failedreason = PC_NOERROR; 118 } 119 } 120 ierr = MatFactorGetError(((PC_Factor*)dir)->fact,&err);CHKERRQ(ierr); 121 if (err) { /* FactorSymbolic() fails */ 122 pc->failedreason = (PCFailedReason)err; 123 PetscFunctionReturn(0); 124 } 125 126 ierr = MatLUFactorNumeric(((PC_Factor*)dir)->fact,pc->pmat,&((PC_Factor*)dir)->info);CHKERRQ(ierr); 127 ierr = MatFactorGetError(((PC_Factor*)dir)->fact,&err);CHKERRQ(ierr); 128 if (err) { /* FactorNumeric() fails */ 129 pc->failedreason = (PCFailedReason)err; 130 } 131 132 } 133 134 ierr = PCFactorGetMatSolverType(pc,&stype);CHKERRQ(ierr); 135 if (!stype) { 136 MatSolverType solverpackage; 137 ierr = MatFactorGetSolverType(((PC_Factor*)dir)->fact,&solverpackage);CHKERRQ(ierr); 138 ierr = PCFactorSetMatSolverType(pc,solverpackage);CHKERRQ(ierr); 139 } 140 PetscFunctionReturn(0); 141 } 142 143 static PetscErrorCode PCReset_LU(PC pc) 144 { 145 PC_LU *dir = (PC_LU*)pc->data; 146 PetscErrorCode ierr; 147 148 PetscFunctionBegin; 149 if (!dir->hdr.inplace && ((PC_Factor*)dir)->fact) {ierr = MatDestroy(&((PC_Factor*)dir)->fact);CHKERRQ(ierr);} 150 if (dir->row && dir->col && dir->row != dir->col) {ierr = ISDestroy(&dir->row);CHKERRQ(ierr);} 151 ierr = ISDestroy(&dir->col);CHKERRQ(ierr); 152 PetscFunctionReturn(0); 153 } 154 155 static PetscErrorCode PCDestroy_LU(PC pc) 156 { 157 PC_LU *dir = (PC_LU*)pc->data; 158 PetscErrorCode ierr; 159 160 PetscFunctionBegin; 161 ierr = PCReset_LU(pc);CHKERRQ(ierr); 162 ierr = PetscFree(((PC_Factor*)dir)->ordering);CHKERRQ(ierr); 163 ierr = PetscFree(((PC_Factor*)dir)->solvertype);CHKERRQ(ierr); 164 ierr = PetscFree(pc->data);CHKERRQ(ierr); 165 PetscFunctionReturn(0); 166 } 167 168 static PetscErrorCode PCApply_LU(PC pc,Vec x,Vec y) 169 { 170 PC_LU *dir = (PC_LU*)pc->data; 171 PetscErrorCode ierr; 172 173 PetscFunctionBegin; 174 if (dir->hdr.inplace) { 175 ierr = MatSolve(pc->pmat,x,y);CHKERRQ(ierr); 176 } else { 177 ierr = MatSolve(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr); 178 } 179 PetscFunctionReturn(0); 180 } 181 182 static PetscErrorCode PCMatApply_LU(PC pc,Mat X,Mat Y) 183 { 184 PC_LU *dir = (PC_LU*)pc->data; 185 PetscErrorCode ierr; 186 187 PetscFunctionBegin; 188 if (dir->hdr.inplace) { 189 ierr = MatMatSolve(pc->pmat,X,Y);CHKERRQ(ierr); 190 } else { 191 ierr = MatMatSolve(((PC_Factor*)dir)->fact,X,Y);CHKERRQ(ierr); 192 } 193 PetscFunctionReturn(0); 194 } 195 196 static PetscErrorCode PCApplyTranspose_LU(PC pc,Vec x,Vec y) 197 { 198 PC_LU *dir = (PC_LU*)pc->data; 199 PetscErrorCode ierr; 200 201 PetscFunctionBegin; 202 if (dir->hdr.inplace) { 203 ierr = MatSolveTranspose(pc->pmat,x,y);CHKERRQ(ierr); 204 } else { 205 ierr = MatSolveTranspose(((PC_Factor*)dir)->fact,x,y);CHKERRQ(ierr); 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 PCFactorSetPivotingInBlocks(),PCFactorSetShiftType(),PCFactorSetShiftAmount() 245 PCFactorReorderForNonzeroDiagonal() 246 M*/ 247 248 PETSC_EXTERN PetscErrorCode PCCreate_LU(PC pc) 249 { 250 PetscErrorCode ierr; 251 PetscMPIInt size; 252 PC_LU *dir; 253 254 PetscFunctionBegin; 255 ierr = PetscNewLog(pc,&dir);CHKERRQ(ierr); 256 pc->data = (void*)dir; 257 ierr = PCFactorInitialize(pc);CHKERRQ(ierr); 258 ((PC_Factor*)dir)->factortype = MAT_FACTOR_LU; 259 dir->nonzerosalongdiagonal = PETSC_FALSE; 260 261 ((PC_Factor*)dir)->info.fill = 5.0; 262 ((PC_Factor*)dir)->info.dtcol = 1.e-6; /* default to pivoting; this is only thing PETSc LU supports */ 263 ((PC_Factor*)dir)->info.shifttype = (PetscReal)MAT_SHIFT_NONE; 264 dir->col = NULL; 265 dir->row = NULL; 266 267 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);CHKERRQ(ierr); 268 if (size == 1) { 269 ierr = PetscStrallocpy(MATORDERINGND,(char**)&((PC_Factor*)dir)->ordering);CHKERRQ(ierr); 270 } else { 271 ierr = PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)dir)->ordering);CHKERRQ(ierr); 272 } 273 274 pc->ops->reset = PCReset_LU; 275 pc->ops->destroy = PCDestroy_LU; 276 pc->ops->apply = PCApply_LU; 277 pc->ops->matapply = PCMatApply_LU; 278 pc->ops->applytranspose = PCApplyTranspose_LU; 279 pc->ops->setup = PCSetUp_LU; 280 pc->ops->setfromoptions = PCSetFromOptions_LU; 281 pc->ops->view = PCView_Factor; 282 pc->ops->applyrichardson = NULL; 283 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C",PCFactorReorderForNonzeroDiagonal_LU);CHKERRQ(ierr); 284 PetscFunctionReturn(0); 285 } 286