1 #pragma once 2 3 /* SUBMANSEC = PC */ 4 5 /*S 6 PC - Abstract PETSc object that manages all preconditioners including direct solvers such as `PCLU` 7 8 Level: beginner 9 10 .seealso: [](doc_linsolve), [](sec_pc), `PCCreate()`, `PCSetType()`, `PCType` 11 S*/ 12 typedef struct _p_PC *PC; 13 14 /*J 15 PCType - String with the name of a PETSc preconditioner 16 17 Level: beginner 18 19 Note: 20 `PCRegister()` is used to register preconditioners that are then accessible via `PCSetType()` 21 22 .seealso: [](doc_linsolve), [](sec_pc), `PCSetType()`, `PC`, `PCCreate()`, `PCRegister()`, `PCSetFromOptions()`, `PCLU`, `PCJACOBI`, `PCBJACOBI` 23 J*/ 24 typedef const char *PCType; 25 #define PCNONE "none" 26 #define PCJACOBI "jacobi" 27 #define PCSOR "sor" 28 #define PCLU "lu" 29 #define PCQR "qr" 30 #define PCSHELL "shell" 31 #define PCAMGX "amgx" 32 #define PCBJACOBI "bjacobi" 33 #define PCMG "mg" 34 #define PCEISENSTAT "eisenstat" 35 #define PCILU "ilu" 36 #define PCICC "icc" 37 #define PCASM "asm" 38 #define PCGASM "gasm" 39 #define PCKSP "ksp" 40 #define PCBJKOKKOS "bjkokkos" 41 #define PCCOMPOSITE "composite" 42 #define PCREDUNDANT "redundant" 43 #define PCSPAI "spai" 44 #define PCNN "nn" 45 #define PCCHOLESKY "cholesky" 46 #define PCPBJACOBI "pbjacobi" 47 #define PCVPBJACOBI "vpbjacobi" 48 #define PCMAT "mat" 49 #define PCHYPRE "hypre" 50 #define PCPARMS "parms" 51 #define PCFIELDSPLIT "fieldsplit" 52 #define PCTFS "tfs" 53 #define PCML "ml" 54 #define PCGALERKIN "galerkin" 55 #define PCEXOTIC "exotic" 56 #define PCCP "cp" 57 #define PCBFBT "bfbt" 58 #define PCLSC "lsc" 59 #define PCPYTHON "python" 60 #define PCPFMG "pfmg" 61 #define PCSMG "smg" 62 #define PCSYSPFMG "syspfmg" 63 #define PCREDISTRIBUTE "redistribute" 64 #define PCSVD "svd" 65 #define PCGAMG "gamg" 66 #define PCCHOWILUVIENNACL "chowiluviennacl" 67 #define PCROWSCALINGVIENNACL "rowscalingviennacl" 68 #define PCSAVIENNACL "saviennacl" 69 #define PCBDDC "bddc" 70 #define PCKACZMARZ "kaczmarz" 71 #define PCTELESCOPE "telescope" 72 #define PCPATCH "patch" 73 #define PCLMVM "lmvm" 74 #define PCHMG "hmg" 75 #define PCDEFLATION "deflation" 76 #define PCHPDDM "hpddm" 77 #define PCH2OPUS "h2opus" 78 #define PCMPI "mpi" 79 80 /*E 81 PCSide - If the preconditioner is to be applied to the left, right 82 or symmetrically around the operator. 83 84 Values: 85 + `PC_LEFT` - applied after the operator is applied 86 . `PC_RIGHT` - applied before the operator is applied 87 - `PC_SYMMETRIC` - a portion of the preconditioner is applied before the operator and the transpose of this portion is applied after the operator is applied. 88 89 Level: beginner 90 91 Note: 92 Certain `KSPType` support only a subset of `PCSide` values 93 94 .seealso: [](sec_pc), `PC`, `KSPSetPCSide()` 95 E*/ 96 typedef enum { 97 PC_SIDE_DEFAULT = -1, 98 PC_LEFT, 99 PC_RIGHT, 100 PC_SYMMETRIC 101 } PCSide; 102 #define PC_SIDE_MAX (PC_SYMMETRIC + 1) 103 104 /*E 105 PCRichardsonConvergedReason - reason a `PCRICHARDSON` `PCApplyRichardson()` method terminated 106 107 Level: advanced 108 109 .seealso: [](sec_pc), `PCRICHARDSON`, `PC`, `PCApplyRichardson()` 110 E*/ 111 typedef enum { 112 PCRICHARDSON_CONVERGED_RTOL = 2, 113 PCRICHARDSON_CONVERGED_ATOL = 3, 114 PCRICHARDSON_CONVERGED_ITS = 4, 115 PCRICHARDSON_DIVERGED_DTOL = -4 116 } PCRichardsonConvergedReason; 117 118 /*E 119 PCJacobiType - What elements of the matrix are used to form the Jacobi preconditioner 120 121 Values: 122 + `PC_JACOBI_DIAGONAL` - use the diagonal entry, if it is zero use one 123 . `PC_JACOBI_ROWMAX` - use the maximum absolute value in the row 124 - `PC_JACOBI_ROWSUM` - use the sum of the values in the row (not the absolute values) 125 126 Level: intermediate 127 128 .seealso: [](sec_pc), `PCJACOBI`, `PC` 129 E*/ 130 typedef enum { 131 PC_JACOBI_DIAGONAL, 132 PC_JACOBI_ROWMAX, 133 PC_JACOBI_ROWSUM 134 } PCJacobiType; 135 136 /*E 137 PCASMType - Type of additive Schwarz method to use 138 139 Values: 140 + `PC_ASM_BASIC` - Symmetric version where residuals from the ghost points are used 141 and computed values in ghost regions are added together. 142 Classical standard additive Schwarz. 143 . `PC_ASM_RESTRICT` - Residuals from ghost points are used but computed values in ghost 144 region are discarded. 145 Default. 146 . `PC_ASM_INTERPOLATE` - Residuals from ghost points are not used, computed values in ghost 147 region are added back in. 148 - `PC_ASM_NONE` - Residuals from ghost points are not used, computed ghost values are 149 discarded. 150 Not very good. 151 152 Level: beginner 153 154 .seealso: [](sec_pc), `PC`, `PCASM`, `PCASMSetType()`, `PCGASMType` 155 E*/ 156 typedef enum { 157 PC_ASM_BASIC = 3, 158 PC_ASM_RESTRICT = 1, 159 PC_ASM_INTERPOLATE = 2, 160 PC_ASM_NONE = 0 161 } PCASMType; 162 163 /*E 164 PCGASMType - Type of generalized additive Schwarz method to use (differs from `PCASM` in allowing multiple processors per subdomain). 165 166 Values: 167 + `PC_GASM_BASIC` - Symmetric version where the full from the outer subdomain is used, and the resulting correction is applied 168 over the outer subdomains. As a result, points in the overlap will receive the sum of the corrections 169 from neighboring subdomains. 170 Classical standard additive Schwarz. 171 . `PC_GASM_RESTRICT` - Residual from the outer subdomain is used but the correction is restricted to the inner subdomain only 172 (i.e., zeroed out over the overlap portion of the outer subdomain before being applied). As a result, 173 each point will receive a correction only from the unique inner subdomain containing it (nonoverlapping covering 174 assumption). 175 Default. 176 . `PC_GASM_INTERPOLATE` - Residual is zeroed out over the overlap portion of the outer subdomain, but the resulting correction is 177 applied over the outer subdomain. As a result, points in the overlap will receive the sum of the corrections 178 from neighboring subdomains. 179 - `PC_GASM_NONE` - Residuals and corrections are zeroed out outside the local subdomains. 180 Not very good. 181 182 Level: beginner 183 184 Note: 185 Each subdomain has nested inner and outer parts. The inner subdomains are assumed to form a non-overlapping covering of the computational 186 domain, while the outer subdomains contain the inner subdomains and overlap with each other. This preconditioner will compute 187 a subdomain correction over each *outer* subdomain from a residual computed there, but its different variants will differ in 188 (a) how the outer subdomain residual is computed, and (b) how the outer subdomain correction is computed. 189 190 .seealso: [](sec_pc), `PCGASM`, `PCASM`, `PC`, `PCGASMSetType()`, `PCASMType` 191 E*/ 192 typedef enum { 193 PC_GASM_BASIC = 3, 194 PC_GASM_RESTRICT = 1, 195 PC_GASM_INTERPOLATE = 2, 196 PC_GASM_NONE = 0 197 } PCGASMType; 198 199 /*E 200 PCCompositeType - Determines how two or more preconditioner are composed with the `PCType` of `PCCOMPOSITE` 201 202 Values: 203 + `PC_COMPOSITE_ADDITIVE` - results from application of all preconditioners are added together 204 . `PC_COMPOSITE_MULTIPLICATIVE` - preconditioners are applied sequentially to the residual freshly 205 computed after the previous preconditioner application 206 . `PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE` - preconditioners are applied sequentially to the residual freshly 207 computed from first preconditioner to last and then back (Use only for symmetric matrices and preconditioners) 208 . `PC_COMPOSITE_SPECIAL` - This is very special for a matrix of the form alpha I + R + S 209 where first preconditioner is built from alpha I + S and second from 210 alpha I + R 211 . `PC_COMPOSITE_SCHUR` - composes the Schur complement of the matrix from two blocks, see `PCFIELDSPLIT` 212 - `PC_COMPOSITE_GKB` - the generalized Golub-Kahan bidiagonalization preconditioner, see `PCFIELDSPLIT` 213 214 Level: beginner 215 216 .seealso: [](sec_pc), `PCCOMPOSITE`, `PCFIELDSPLIT`, `PC`, `PCCompositeSetType()`, `SNESCompositeType` 217 E*/ 218 typedef enum { 219 PC_COMPOSITE_ADDITIVE, 220 PC_COMPOSITE_MULTIPLICATIVE, 221 PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE, 222 PC_COMPOSITE_SPECIAL, 223 PC_COMPOSITE_SCHUR, 224 PC_COMPOSITE_GKB 225 } PCCompositeType; 226 227 /*E 228 PCFieldSplitSchurPreType - Determines how to precondition a Schur complement 229 230 Values: 231 + `PC_FIELDSPLIT_SCHUR_PRE_SELF` - the preconditioner for the Schur complement is generated from the symbolic representation of the Schur complement matrix. 232 The only preconditioners that currently work with this symbolic representation matrix object are `PCLSC` and `PCHPDDM` 233 . `PC_FIELDSPLIT_SCHUR_PRE_SELFP` - the preconditioning for the Schur complement is generated from an explicitly-assembled approximation Sp = A11 - A10 inv(diag(A00)) A01. 234 This is only a good preconditioner when diag(A00) is a good preconditioner for A00. Optionally, A00 can be 235 lumped before extracting the diagonal using the additional option `-fieldsplit_1_mat_schur_complement_ainv_type lump` 236 . `PC_FIELDSPLIT_SCHUR_PRE_A11` - the preconditioner for the Schur complement is generated from the block diagonal part of the matrix used to define the preconditioner, 237 associated with the Schur complement (i.e. A11), not the Schur complement matrix 238 . `PC_FIELDSPLIT_SCHUR_PRE_USER` - the preconditioner for the Schur complement is generated from the user provided matrix (pre argument 239 to this function). 240 - `PC_FIELDSPLIT_SCHUR_PRE_FULL` - the preconditioner for the Schur complement is generated from the exact Schur complement matrix representation 241 computed internally by `PCFIELDSPLIT` (this is expensive) useful mostly as a test that the Schur complement approach can work for your problem 242 243 Level: intermediate 244 245 .seealso: [](sec_pc), `PCFIELDSPLIT`, `PCFieldSplitSetSchurPre()`, `PC` 246 E*/ 247 typedef enum { 248 PC_FIELDSPLIT_SCHUR_PRE_SELF, 249 PC_FIELDSPLIT_SCHUR_PRE_SELFP, 250 PC_FIELDSPLIT_SCHUR_PRE_A11, 251 PC_FIELDSPLIT_SCHUR_PRE_USER, 252 PC_FIELDSPLIT_SCHUR_PRE_FULL 253 } PCFieldSplitSchurPreType; 254 255 /*E 256 PCFieldSplitSchurFactType - determines which off-diagonal parts of the approximate block factorization to use 257 258 Values: 259 + `PC_FIELDSPLIT_SCHUR_FACT_DIAG` - the preconditioner is solving `D` 260 . `PC_FIELDSPLIT_SCHUR_FACT_LOWER` - the preconditioner is solving `L D` 261 . `PC_FIELDSPLIT_SCHUR_FACT_UPPER` - the preconditioner is solving `D U` 262 - `PC_FIELDSPLIT_SCHUR_FACT_FULL` - the preconditioner is solving `L(D U)` 263 264 where the matrix is factorized as 265 .vb 266 (A B) = (1 0) (A 0) (1 Ainv*B) = L D U 267 (C E) (C*Ainv 1) (0 S) (0 1) 268 .ve 269 270 Level: intermediate 271 272 .seealso: [](sec_pc), `PCFIELDSPLIT`, `PCFieldSplitSetSchurFactType()`, `PC` 273 E*/ 274 typedef enum { 275 PC_FIELDSPLIT_SCHUR_FACT_DIAG, 276 PC_FIELDSPLIT_SCHUR_FACT_LOWER, 277 PC_FIELDSPLIT_SCHUR_FACT_UPPER, 278 PC_FIELDSPLIT_SCHUR_FACT_FULL 279 } PCFieldSplitSchurFactType; 280 281 /*E 282 PCPARMSGlobalType - Determines the global preconditioner method in `PCPARMS` 283 284 Level: intermediate 285 286 .seealso: [](sec_pc), `PCPARMS`, `PCPARMSSetGlobal()`, `PC` 287 E*/ 288 typedef enum { 289 PC_PARMS_GLOBAL_RAS, 290 PC_PARMS_GLOBAL_SCHUR, 291 PC_PARMS_GLOBAL_BJ 292 } PCPARMSGlobalType; 293 294 /*E 295 PCPARMSLocalType - Determines the local preconditioner method in `PCPARMS` 296 297 Level: intermediate 298 299 .seealso: [](sec_pc), `PCPARMS`, `PCPARMSSetLocal()`, `PC` 300 E*/ 301 typedef enum { 302 PC_PARMS_LOCAL_ILU0, 303 PC_PARMS_LOCAL_ILUK, 304 PC_PARMS_LOCAL_ILUT, 305 PC_PARMS_LOCAL_ARMS 306 } PCPARMSLocalType; 307 308 /*J 309 PCGAMGType - type of generalized algebraic multigrid `PCGAMG` method 310 311 Values: 312 + `PCGAMGAGG` - (the default) smoothed aggregation algorithm, robust, very well tested 313 . `PCGAMGGEO` - geometric coarsening, uses mesh generator to produce coarser meshes, limited to triangles, not supported, reference implementation (2D) 314 - `PCGAMGCLASSICAL` - classical algebraic multigrid preconditioner, incomplete, not supported, reference implementation 315 316 Level: intermediate 317 318 .seealso: [](sec_pc), `PCGAMG`, `PCMG`, `PC`, `PCSetType()`, `PCGAMGSetThreshold()`, `PCGAMGSetThreshold()`, `PCGAMGSetReuseInterpolation()` 319 J*/ 320 typedef const char *PCGAMGType; 321 #define PCGAMGAGG "agg" 322 #define PCGAMGGEO "geo" 323 #define PCGAMGCLASSICAL "classical" 324 325 typedef const char *PCGAMGClassicalType; 326 #define PCGAMGCLASSICALDIRECT "direct" 327 #define PCGAMGCLASSICALSTANDARD "standard" 328 329 /*E 330 PCMGType - Determines the type of multigrid method that is run. 331 332 Values: 333 + `PC_MG_MULTIPLICATIVE` (default) - traditional V or W cycle as determined by `PCMGSetCycleType()` 334 . `PC_MG_ADDITIVE` - the additive multigrid preconditioner where all levels are 335 smoothed before updating the residual. This only uses the 336 down smoother, in the preconditioner the upper smoother is ignored 337 . `PC_MG_FULL` - same as multiplicative except one also performs grid sequencing, 338 that is starts on the coarsest grid, performs a cycle, interpolates 339 to the next, performs a cycle etc. This is much like the F-cycle presented in "Multigrid" by Trottenberg, Oosterlee, Schuller page 49, but that 340 algorithm supports smoothing on before the restriction on each level in the initial restriction to the coarsest stage. In addition that algorithm 341 calls the V-cycle only on the coarser level and has a post-smoother instead. 342 - `PC_MG_KASKADE` - like full multigrid except one never goes back to a coarser level from a finer 343 344 Level: beginner 345 346 .seealso: [](sec_pc), `PCMG`, `PC`, `PCMGSetType()`, `PCMGSetCycleType()`, `PCMGSetCycleTypeOnLevel()` 347 E*/ 348 typedef enum { 349 PC_MG_MULTIPLICATIVE, 350 PC_MG_ADDITIVE, 351 PC_MG_FULL, 352 PC_MG_KASKADE 353 } PCMGType; 354 #define PC_MG_CASCADE PC_MG_KASKADE; 355 356 /*E 357 PCMGCycleType - Use V-cycle or W-cycle 358 359 Values: 360 + `PC_MG_V_CYCLE` - use the v cycle 361 - `PC_MG_W_CYCLE` - use the w cycle 362 363 Level: beginner 364 365 .seealso: [](sec_pc), `PCMG`, `PC`, `PCMGSetCycleType()` 366 E*/ 367 typedef enum { 368 PC_MG_CYCLE_V = 1, 369 PC_MG_CYCLE_W = 2 370 } PCMGCycleType; 371 372 /*E 373 PCMGalerkinType - Determines if the coarse grid operators are computed via the Galerkin process 374 375 Values: 376 + `PC_MG_GALERKIN_PMAT` - computes the pmat (matrix from which the preconditioner is built) via the Galerkin process from the finest grid 377 . `PC_MG_GALERKIN_MAT` - computes the mat (matrix used to apply the operator) via the Galerkin process from the finest grid 378 . `PC_MG_GALERKIN_BOTH` - computes both the mat and pmat via the Galerkin process (if pmat == mat the construction is only done once 379 - `PC_MG_GALERKIN_NONE` - neither operator is computed via the Galerkin process, the user must provide the operator 380 381 Level: beginner 382 383 Note: 384 Users should never set `PC_MG_GALERKIN_EXTERNAL`, it is used by `PCHYPRE` and `PCML` 385 386 .seealso: [](sec_pc), `PCMG`, `PC`, `PCMGSetCycleType()` 387 E*/ 388 typedef enum { 389 PC_MG_GALERKIN_BOTH, 390 PC_MG_GALERKIN_PMAT, 391 PC_MG_GALERKIN_MAT, 392 PC_MG_GALERKIN_NONE, 393 PC_MG_GALERKIN_EXTERNAL 394 } PCMGGalerkinType; 395 396 /*E 397 PCExoticType - Face based or wirebasket based coarse grid space 398 399 Level: beginner 400 401 .seealso: [](sec_pc), `PCExoticSetType()`, `PCEXOTIC` 402 E*/ 403 typedef enum { 404 PC_EXOTIC_FACE, 405 PC_EXOTIC_WIREBASKET 406 } PCExoticType; 407 408 /*E 409 PCBDDCInterfaceExtType - Defines how interface balancing is extended into the interior of subdomains. 410 411 Values: 412 + `PC_BDDC_INTERFACE_EXT_DIRICHLET` - solves Dirichlet interior problem; this is the standard BDDC algorithm 413 - `PC_BDDC_INTERFACE_EXT_LUMP` - skips interior solve; sometimes called M_1 and associated with "lumped FETI-DP" 414 415 Level: intermediate 416 417 .seealso: [](sec_pc), `PCBDDC`, `PC` 418 E*/ 419 typedef enum { 420 PC_BDDC_INTERFACE_EXT_DIRICHLET, 421 PC_BDDC_INTERFACE_EXT_LUMP 422 } PCBDDCInterfaceExtType; 423 424 /*E 425 PCMGCoarseSpaceType - Function space for coarse space for adaptive interpolation 426 427 Level: beginner 428 429 .seealso: [](sec_pc), `PCMGSetAdaptCoarseSpaceType()`, `PCMG`, `PC` 430 E*/ 431 typedef enum { 432 PCMG_ADAPT_NONE, 433 PCMG_ADAPT_POLYNOMIAL, 434 PCMG_ADAPT_HARMONIC, 435 PCMG_ADAPT_EIGENVECTOR, 436 PCMG_ADAPT_GENERALIZED_EIGENVECTOR, 437 PCMG_ADAPT_GDSW 438 } PCMGCoarseSpaceType; 439 440 /*E 441 PCPatchConstructType - The algorithm used to construct patches for the `PCPATCH` preconditioner 442 443 Level: beginner 444 445 .seealso: [](sec_pc), `PCPatchSetConstructType()`, `PCPATCH`, `PC` 446 E*/ 447 typedef enum { 448 PC_PATCH_STAR, 449 PC_PATCH_VANKA, 450 PC_PATCH_PARDECOMP, 451 PC_PATCH_USER, 452 PC_PATCH_PYTHON 453 } PCPatchConstructType; 454 455 /*E 456 PCDeflationSpaceType - Type of deflation 457 458 Values: 459 + `PC_DEFLATION_SPACE_HAAR` - directly assembled based on Haar (db2) wavelet with overflowed filter cuted-off 460 . `PC_DEFLATION_SPACE_DB2` - `MATCOMPOSITE` of 1-lvl matices based on db2 (2 coefficient Daubechies / Haar wavelet) 461 . `PC_DEFLATION_SPACE_DB4` - same as above, but with db4 (4 coefficient Daubechies) 462 . `PC_DEFLATION_SPACE_DB8` - same as above, but with db8 (8 coefficient Daubechies) 463 . `PC_DEFLATION_SPACE_DB16` - same as above, but with db16 (16 coefficient Daubechies) 464 . `PC_DEFLATION_SPACE_BIORTH22` - same as above, but with biorthogonal 2.2 (6 coefficients) 465 . `PC_DEFLATION_SPACE_MEYER` - same as above, but with Meyer/FIR (62 coefficients) 466 . `PC_DEFLATION_SPACE_AGGREGATION` - aggregates local indices (given by operator matrix distribution) into a subdomain 467 - `PC_DEFLATION_SPACE_USER` - indicates space set by user 468 469 Level: intermediate 470 471 Note: 472 Wavelet-based space (except Haar) can be used in multilevel deflation. 473 474 .seealso: [](sec_pc), `PCDeflationSetSpaceToCompute()`, `PCDEFLATION`, `PC` 475 E*/ 476 typedef enum { 477 PC_DEFLATION_SPACE_HAAR, 478 PC_DEFLATION_SPACE_DB2, 479 PC_DEFLATION_SPACE_DB4, 480 PC_DEFLATION_SPACE_DB8, 481 PC_DEFLATION_SPACE_DB16, 482 PC_DEFLATION_SPACE_BIORTH22, 483 PC_DEFLATION_SPACE_MEYER, 484 PC_DEFLATION_SPACE_AGGREGATION, 485 PC_DEFLATION_SPACE_USER 486 } PCDeflationSpaceType; 487 488 /*E 489 PCHPDDMCoarseCorrectionType - Type of coarse correction used by `PCHPDDM` 490 491 Values: 492 + `PC_HPDDM_COARSE_CORRECTION_DEFLATED` (default) - eq. (1) in `PCHPDDMShellApply()` 493 . `PC_HPDDM_COARSE_CORRECTION_ADDITIVE` - eq. (2) 494 - `PC_HPDDM_COARSE_CORRECTION_BALANCED` - eq. (3) 495 496 Level: intermediate 497 498 .seealso: [](sec_pc), `PCHPDDM`, `PC`, `PCSetType()`, `PCHPDDMShellApply()` 499 E*/ 500 typedef enum { 501 PC_HPDDM_COARSE_CORRECTION_DEFLATED, 502 PC_HPDDM_COARSE_CORRECTION_ADDITIVE, 503 PC_HPDDM_COARSE_CORRECTION_BALANCED 504 } PCHPDDMCoarseCorrectionType; 505 506 /*E 507 PCHPDDMSchurPreType - Type of `PCHPDDM` preconditioner for a `MATSCHURCOMPLEMENT` generated by `PCFIELDSPLIT` with `PCFieldSplitSchurPreType` set to `PC_FIELDSPLIT_SCHUR_PRE_SELF` 508 509 Values: 510 + `PC_HPDDM_SCHUR_PRE_LEAST_SQUARES` (default) - only with a near-zero A11 block and A10 = A01^T; a preconditioner for solving A01^T A00^-1 A01 x = b is built by approximating the Schur complement with (inv(sqrt(diag(A00))) A01)^T (inv(sqrt(diag(A00))) A01) and by considering the associated linear least squares problem 511 - `PC_HPDDM_SCHUR_PRE_GENEO` - only with A10 = A01^T, `PCHPDDMSetAuxiliaryMat()` called on the `PC` of the A00 block, and if A11 is nonzero, then `PCHPDDMSetAuxiliaryMat()` must be called on the associated `PC` as well (it is built automatically for the user otherwise); the Schur complement `PC` is set internally to `PCKSP`, with the prefix `-fieldsplit_1_pc_hpddm_`; the operator associated to the `PC` is spectrally equivalent to the original Schur complement 512 513 Level: advanced 514 515 .seealso: [](sec_pc), `PCHPDDM`, `PC`, `PCFIELDSPLIT`, `PC_FIELDSPLIT_SCHUR_PRE_SELF`, `PCFieldSplitSetSchurPre()`, `PCHPDDMSetAuxiliaryMat()` 516 E*/ 517 typedef enum { 518 PC_HPDDM_SCHUR_PRE_LEAST_SQUARES, 519 PC_HPDDM_SCHUR_PRE_GENEO, 520 } PCHPDDMSchurPreType; 521 522 /*E 523 PCFailedReason - indicates type of `PC` failure 524 525 Level: beginner 526 527 .seealso: [](sec_pc), `PC` 528 E*/ 529 typedef enum { 530 PC_SETUP_ERROR = -1, 531 PC_NOERROR, 532 PC_FACTOR_STRUCT_ZEROPIVOT, 533 PC_FACTOR_NUMERIC_ZEROPIVOT, 534 PC_FACTOR_OUTMEMORY, 535 PC_FACTOR_OTHER, 536 PC_INCONSISTENT_RHS, 537 PC_SUBPC_ERROR 538 } PCFailedReason; 539 540 /*E 541 PCGAMGLayoutType - Layout for reduced grids 542 543 Level: intermediate 544 545 .seealso: [](sec_pc), `PCGAMG`, `PC`, `PCGAMGSetCoarseGridLayoutType()` 546 E*/ 547 typedef enum { 548 PCGAMG_LAYOUT_COMPACT, 549 PCGAMG_LAYOUT_SPREAD 550 } PCGAMGLayoutType; 551