1 2 #include <petsc-private/pcimpl.h> /*I "petscpc.h" I*/ 3 #include <petscdm.h> 4 5 6 const char *const PCFieldSplitSchurPreTypes[] = {"SELF","SELFP","A11","USER","FULL","PCFieldSplitSchurPreType","PC_FIELDSPLIT_SCHUR_PRE_",0}; 7 const char *const PCFieldSplitSchurFactTypes[] = {"DIAG","LOWER","UPPER","FULL","PCFieldSplitSchurFactType","PC_FIELDSPLIT_SCHUR_FACT_",0}; 8 9 typedef struct _PC_FieldSplitLink *PC_FieldSplitLink; 10 struct _PC_FieldSplitLink { 11 KSP ksp; 12 Vec x,y,z; 13 char *splitname; 14 PetscInt nfields; 15 PetscInt *fields,*fields_col; 16 VecScatter sctx; 17 IS is,is_col; 18 PC_FieldSplitLink next,previous; 19 }; 20 21 typedef struct { 22 PCCompositeType type; 23 PetscBool defaultsplit; /* Flag for a system with a set of 'k' scalar fields with the same layout (and bs = k) */ 24 PetscBool splitdefined; /* Flag is set after the splits have been defined, to prevent more splits from being added */ 25 PetscInt bs; /* Block size for IS and Mat structures */ 26 PetscInt nsplits; /* Number of field divisions defined */ 27 Vec *x,*y,w1,w2; 28 Mat *mat; /* The diagonal block for each split */ 29 Mat *pmat; /* The preconditioning diagonal block for each split */ 30 Mat *Afield; /* The rows of the matrix associated with each split */ 31 PetscBool issetup; 32 33 /* Only used when Schur complement preconditioning is used */ 34 Mat B; /* The (0,1) block */ 35 Mat C; /* The (1,0) block */ 36 Mat schur; /* The Schur complement S = A11 - A10 A00^{-1} A01, the KSP here, kspinner, is H_1 in [El08] */ 37 Mat schurp; /* Assembled approximation to S built by MatSchurComplement to be used as a preconditioning matrix when solving with S */ 38 Mat schur_user; /* User-provided preconditioning matrix for the Schur complement */ 39 PCFieldSplitSchurPreType schurpre; /* Determines which preconditioning matrix is used for the Schur complement */ 40 PCFieldSplitSchurFactType schurfactorization; 41 KSP kspschur; /* The solver for S */ 42 KSP kspupper; /* The solver for A in the upper diagonal part of the factorization (H_2 in [El08]) */ 43 PC_FieldSplitLink head; 44 PetscBool reset; /* indicates PCReset() has been last called on this object, hack */ 45 PetscBool suboptionsset; /* Indicates that the KSPSetFromOptions() has been called on the sub-KSPs */ 46 PetscBool dm_splits; /* Whether to use DMCreateFieldDecomposition() whenever possible */ 47 PetscBool diag_use_amat; /* Whether to extract diagonal matrix blocks from Amat, rather than Pmat (weaker than -pc_use_amat) */ 48 PetscBool offdiag_use_amat; /* Whether to extract off-diagonal matrix blocks from Amat, rather than Pmat (weaker than -pc_use_amat) */ 49 } PC_FieldSplit; 50 51 /* 52 Notes: there is no particular reason that pmat, x, and y are stored as arrays in PC_FieldSplit instead of 53 inside PC_FieldSplitLink, just historical. If you want to be able to add new fields after already using the 54 PC you could change this. 55 */ 56 57 /* This helper is so that setting a user-provided preconditioning matrix is orthogonal to choosing to use it. This way the 58 * application-provided FormJacobian can provide this matrix without interfering with the user's (command-line) choices. */ 59 static Mat FieldSplitSchurPre(PC_FieldSplit *jac) 60 { 61 switch (jac->schurpre) { 62 case PC_FIELDSPLIT_SCHUR_PRE_SELF: return jac->schur; 63 case PC_FIELDSPLIT_SCHUR_PRE_SELFP: return jac->schurp; 64 case PC_FIELDSPLIT_SCHUR_PRE_A11: return jac->pmat[1]; 65 case PC_FIELDSPLIT_SCHUR_PRE_FULL: /* We calculate this and store it in schur_user */ 66 case PC_FIELDSPLIT_SCHUR_PRE_USER: /* Use a user-provided matrix if it is given, otherwise diagonal block */ 67 default: 68 return jac->schur_user ? jac->schur_user : jac->pmat[1]; 69 } 70 } 71 72 73 #include <petscdraw.h> 74 #undef __FUNCT__ 75 #define __FUNCT__ "PCView_FieldSplit" 76 static PetscErrorCode PCView_FieldSplit(PC pc,PetscViewer viewer) 77 { 78 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 79 PetscErrorCode ierr; 80 PetscBool iascii,isdraw; 81 PetscInt i,j; 82 PC_FieldSplitLink ilink = jac->head; 83 84 PetscFunctionBegin; 85 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 86 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr); 87 if (iascii) { 88 if (jac->bs > 0) { 89 ierr = PetscViewerASCIIPrintf(viewer," FieldSplit with %s composition: total splits = %D, blocksize = %D\n",PCCompositeTypes[jac->type],jac->nsplits,jac->bs);CHKERRQ(ierr); 90 } else { 91 ierr = PetscViewerASCIIPrintf(viewer," FieldSplit with %s composition: total splits = %D\n",PCCompositeTypes[jac->type],jac->nsplits);CHKERRQ(ierr); 92 } 93 if (pc->useAmat) { 94 ierr = PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for blocks\n");CHKERRQ(ierr); 95 } 96 if (jac->diag_use_amat) { 97 ierr = PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for diagonal blocks\n");CHKERRQ(ierr); 98 } 99 if (jac->offdiag_use_amat) { 100 ierr = PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for off-diagonal blocks\n");CHKERRQ(ierr); 101 } 102 ierr = PetscViewerASCIIPrintf(viewer," Solver info for each split is in the following KSP objects:\n");CHKERRQ(ierr); 103 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 104 for (i=0; i<jac->nsplits; i++) { 105 if (ilink->fields) { 106 ierr = PetscViewerASCIIPrintf(viewer,"Split number %D Fields ",i);CHKERRQ(ierr); 107 ierr = PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);CHKERRQ(ierr); 108 for (j=0; j<ilink->nfields; j++) { 109 if (j > 0) { 110 ierr = PetscViewerASCIIPrintf(viewer,",");CHKERRQ(ierr); 111 } 112 ierr = PetscViewerASCIIPrintf(viewer," %D",ilink->fields[j]);CHKERRQ(ierr); 113 } 114 ierr = PetscViewerASCIIPrintf(viewer,"\n");CHKERRQ(ierr); 115 ierr = PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);CHKERRQ(ierr); 116 } else { 117 ierr = PetscViewerASCIIPrintf(viewer,"Split number %D Defined by IS\n",i);CHKERRQ(ierr); 118 } 119 ierr = KSPView(ilink->ksp,viewer);CHKERRQ(ierr); 120 ilink = ilink->next; 121 } 122 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 123 } 124 125 if (isdraw) { 126 PetscDraw draw; 127 PetscReal x,y,w,wd; 128 129 ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr); 130 ierr = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr); 131 w = 2*PetscMin(1.0 - x,x); 132 wd = w/(jac->nsplits + 1); 133 x = x - wd*(jac->nsplits-1)/2.0; 134 for (i=0; i<jac->nsplits; i++) { 135 ierr = PetscDrawPushCurrentPoint(draw,x,y);CHKERRQ(ierr); 136 ierr = KSPView(ilink->ksp,viewer);CHKERRQ(ierr); 137 ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr); 138 x += wd; 139 ilink = ilink->next; 140 } 141 } 142 PetscFunctionReturn(0); 143 } 144 145 #undef __FUNCT__ 146 #define __FUNCT__ "PCView_FieldSplit_Schur" 147 static PetscErrorCode PCView_FieldSplit_Schur(PC pc,PetscViewer viewer) 148 { 149 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 150 PetscErrorCode ierr; 151 PetscBool iascii,isdraw; 152 PetscInt i,j; 153 PC_FieldSplitLink ilink = jac->head; 154 155 PetscFunctionBegin; 156 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 157 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr); 158 if (iascii) { 159 if (jac->bs > 0) { 160 ierr = PetscViewerASCIIPrintf(viewer," FieldSplit with Schur preconditioner, blocksize = %D, factorization %s\n",jac->bs,PCFieldSplitSchurFactTypes[jac->schurfactorization]);CHKERRQ(ierr); 161 } else { 162 ierr = PetscViewerASCIIPrintf(viewer," FieldSplit with Schur preconditioner, factorization %s\n",PCFieldSplitSchurFactTypes[jac->schurfactorization]);CHKERRQ(ierr); 163 } 164 if (pc->useAmat) { 165 ierr = PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for blocks\n");CHKERRQ(ierr); 166 } 167 switch (jac->schurpre) { 168 case PC_FIELDSPLIT_SCHUR_PRE_SELF: 169 ierr = PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from S itself\n");CHKERRQ(ierr);break; 170 case PC_FIELDSPLIT_SCHUR_PRE_SELFP: 171 ierr = PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from Sp, an assembled approximation to S, which uses (the lumped) A00's diagonal's inverse\n");CHKERRQ(ierr);break; 172 case PC_FIELDSPLIT_SCHUR_PRE_A11: 173 ierr = PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from A11\n");CHKERRQ(ierr);break; 174 case PC_FIELDSPLIT_SCHUR_PRE_FULL: 175 ierr = PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from the exact Schur complement\n");CHKERRQ(ierr);break; 176 case PC_FIELDSPLIT_SCHUR_PRE_USER: 177 if (jac->schur_user) { 178 ierr = PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from user provided matrix\n");CHKERRQ(ierr); 179 } else { 180 ierr = PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from A11\n");CHKERRQ(ierr); 181 } 182 break; 183 default: 184 SETERRQ1(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_OUTOFRANGE, "Invalid Schur preconditioning type: %d", jac->schurpre); 185 } 186 ierr = PetscViewerASCIIPrintf(viewer," Split info:\n");CHKERRQ(ierr); 187 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 188 for (i=0; i<jac->nsplits; i++) { 189 if (ilink->fields) { 190 ierr = PetscViewerASCIIPrintf(viewer,"Split number %D Fields ",i);CHKERRQ(ierr); 191 ierr = PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);CHKERRQ(ierr); 192 for (j=0; j<ilink->nfields; j++) { 193 if (j > 0) { 194 ierr = PetscViewerASCIIPrintf(viewer,",");CHKERRQ(ierr); 195 } 196 ierr = PetscViewerASCIIPrintf(viewer," %D",ilink->fields[j]);CHKERRQ(ierr); 197 } 198 ierr = PetscViewerASCIIPrintf(viewer,"\n");CHKERRQ(ierr); 199 ierr = PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);CHKERRQ(ierr); 200 } else { 201 ierr = PetscViewerASCIIPrintf(viewer,"Split number %D Defined by IS\n",i);CHKERRQ(ierr); 202 } 203 ilink = ilink->next; 204 } 205 ierr = PetscViewerASCIIPrintf(viewer,"KSP solver for A00 block\n");CHKERRQ(ierr); 206 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 207 if (jac->head) { 208 ierr = KSPView(jac->head->ksp,viewer);CHKERRQ(ierr); 209 } else {ierr = PetscViewerASCIIPrintf(viewer," not yet available\n");CHKERRQ(ierr);} 210 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 211 if (jac->head && jac->kspupper != jac->head->ksp) { 212 ierr = PetscViewerASCIIPrintf(viewer,"KSP solver for upper A00 in upper triangular factor \n");CHKERRQ(ierr); 213 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 214 if (jac->kspupper) {ierr = KSPView(jac->kspupper,viewer);CHKERRQ(ierr);} 215 else {ierr = PetscViewerASCIIPrintf(viewer," not yet available\n");CHKERRQ(ierr);} 216 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 217 } 218 ierr = PetscViewerASCIIPrintf(viewer,"KSP solver for S = A11 - A10 inv(A00) A01 \n");CHKERRQ(ierr); 219 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 220 if (jac->kspschur) { 221 ierr = KSPView(jac->kspschur,viewer);CHKERRQ(ierr); 222 } else { 223 ierr = PetscViewerASCIIPrintf(viewer," not yet available\n");CHKERRQ(ierr); 224 } 225 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 226 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 227 } else if (isdraw && jac->head) { 228 PetscDraw draw; 229 PetscReal x,y,w,wd,h; 230 PetscInt cnt = 2; 231 char str[32]; 232 233 ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr); 234 ierr = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr); 235 if (jac->kspupper != jac->head->ksp) cnt++; 236 w = 2*PetscMin(1.0 - x,x); 237 wd = w/(cnt + 1); 238 239 ierr = PetscSNPrintf(str,32,"Schur fact. %s",PCFieldSplitSchurFactTypes[jac->schurfactorization]);CHKERRQ(ierr); 240 ierr = PetscDrawBoxedString(draw,x,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);CHKERRQ(ierr); 241 y -= h; 242 if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_USER && !jac->schur_user) { 243 ierr = PetscSNPrintf(str,32,"Prec. for Schur from %s",PCFieldSplitSchurPreTypes[PC_FIELDSPLIT_SCHUR_PRE_A11]);CHKERRQ(ierr); 244 } else { 245 ierr = PetscSNPrintf(str,32,"Prec. for Schur from %s",PCFieldSplitSchurPreTypes[jac->schurpre]);CHKERRQ(ierr); 246 } 247 ierr = PetscDrawBoxedString(draw,x+wd*(cnt-1)/2.0,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);CHKERRQ(ierr); 248 y -= h; 249 x = x - wd*(cnt-1)/2.0; 250 251 ierr = PetscDrawPushCurrentPoint(draw,x,y);CHKERRQ(ierr); 252 ierr = KSPView(jac->head->ksp,viewer);CHKERRQ(ierr); 253 ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr); 254 if (jac->kspupper != jac->head->ksp) { 255 x += wd; 256 ierr = PetscDrawPushCurrentPoint(draw,x,y);CHKERRQ(ierr); 257 ierr = KSPView(jac->kspupper,viewer);CHKERRQ(ierr); 258 ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr); 259 } 260 x += wd; 261 ierr = PetscDrawPushCurrentPoint(draw,x,y);CHKERRQ(ierr); 262 ierr = KSPView(jac->kspschur,viewer);CHKERRQ(ierr); 263 ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr); 264 } 265 PetscFunctionReturn(0); 266 } 267 268 #undef __FUNCT__ 269 #define __FUNCT__ "PCFieldSplitSetRuntimeSplits_Private" 270 /* Precondition: jac->bs is set to a meaningful value */ 271 static PetscErrorCode PCFieldSplitSetRuntimeSplits_Private(PC pc) 272 { 273 PetscErrorCode ierr; 274 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 275 PetscInt i,nfields,*ifields,nfields_col,*ifields_col; 276 PetscBool flg,flg_col; 277 char optionname[128],splitname[8],optionname_col[128]; 278 279 PetscFunctionBegin; 280 ierr = PetscMalloc1(jac->bs,&ifields);CHKERRQ(ierr); 281 ierr = PetscMalloc1(jac->bs,&ifields_col);CHKERRQ(ierr); 282 for (i=0,flg=PETSC_TRUE;; i++) { 283 ierr = PetscSNPrintf(splitname,sizeof(splitname),"%D",i);CHKERRQ(ierr); 284 ierr = PetscSNPrintf(optionname,sizeof(optionname),"-pc_fieldsplit_%D_fields",i);CHKERRQ(ierr); 285 ierr = PetscSNPrintf(optionname_col,sizeof(optionname_col),"-pc_fieldsplit_%D_fields_col",i);CHKERRQ(ierr); 286 nfields = jac->bs; 287 nfields_col = jac->bs; 288 ierr = PetscOptionsGetIntArray(((PetscObject)pc)->prefix,optionname,ifields,&nfields,&flg);CHKERRQ(ierr); 289 ierr = PetscOptionsGetIntArray(((PetscObject)pc)->prefix,optionname_col,ifields_col,&nfields_col,&flg_col);CHKERRQ(ierr); 290 if (!flg) break; 291 else if (flg && !flg_col) { 292 if (!nfields) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Cannot list zero fields"); 293 ierr = PCFieldSplitSetFields(pc,splitname,nfields,ifields,ifields);CHKERRQ(ierr); 294 } else { 295 if (!nfields || !nfields_col) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Cannot list zero fields"); 296 if (nfields != nfields_col) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Number of row and column fields must match"); 297 ierr = PCFieldSplitSetFields(pc,splitname,nfields,ifields,ifields_col);CHKERRQ(ierr); 298 } 299 } 300 if (i > 0) { 301 /* Makes command-line setting of splits take precedence over setting them in code. 302 Otherwise subsequent calls to PCFieldSplitSetIS() or PCFieldSplitSetFields() would 303 create new splits, which would probably not be what the user wanted. */ 304 jac->splitdefined = PETSC_TRUE; 305 } 306 ierr = PetscFree(ifields);CHKERRQ(ierr); 307 ierr = PetscFree(ifields_col);CHKERRQ(ierr); 308 PetscFunctionReturn(0); 309 } 310 311 #undef __FUNCT__ 312 #define __FUNCT__ "PCFieldSplitSetDefaults" 313 static PetscErrorCode PCFieldSplitSetDefaults(PC pc) 314 { 315 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 316 PetscErrorCode ierr; 317 PC_FieldSplitLink ilink = jac->head; 318 PetscBool fieldsplit_default = PETSC_FALSE,stokes = PETSC_FALSE,coupling = PETSC_FALSE; 319 PetscInt i; 320 321 PetscFunctionBegin; 322 /* 323 Kinda messy, but at least this now uses DMCreateFieldDecomposition() even with jac->reset. 324 Should probably be rewritten. 325 */ 326 if (!ilink || jac->reset) { 327 ierr = PetscOptionsGetBool(((PetscObject)pc)->prefix,"-pc_fieldsplit_detect_saddle_point",&stokes,NULL);CHKERRQ(ierr); 328 ierr = PetscOptionsGetBool(((PetscObject)pc)->prefix,"-pc_fieldsplit_detect_coupling",&coupling,NULL);CHKERRQ(ierr); 329 if (pc->dm && jac->dm_splits && !stokes && !coupling) { 330 PetscInt numFields, f, i, j; 331 char **fieldNames; 332 IS *fields; 333 DM *dms; 334 DM subdm[128]; 335 PetscBool flg; 336 337 ierr = DMCreateFieldDecomposition(pc->dm, &numFields, &fieldNames, &fields, &dms);CHKERRQ(ierr); 338 /* Allow the user to prescribe the splits */ 339 for (i = 0, flg = PETSC_TRUE;; i++) { 340 PetscInt ifields[128]; 341 IS compField; 342 char optionname[128], splitname[8]; 343 PetscInt nfields = numFields; 344 345 ierr = PetscSNPrintf(optionname, sizeof(optionname), "-pc_fieldsplit_%D_fields", i);CHKERRQ(ierr); 346 ierr = PetscOptionsGetIntArray(((PetscObject) pc)->prefix, optionname, ifields, &nfields, &flg);CHKERRQ(ierr); 347 if (!flg) break; 348 if (numFields > 128) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot currently support %d > 128 fields", numFields); 349 ierr = DMCreateSubDM(pc->dm, nfields, ifields, &compField, &subdm[i]);CHKERRQ(ierr); 350 if (nfields == 1) { 351 ierr = PCFieldSplitSetIS(pc, fieldNames[ifields[0]], compField);CHKERRQ(ierr); 352 /* ierr = PetscPrintf(PetscObjectComm((PetscObject)pc), "%s Field Indices:", fieldNames[ifields[0]]);CHKERRQ(ierr); 353 ierr = ISView(compField, NULL);CHKERRQ(ierr); */ 354 } else { 355 ierr = PetscSNPrintf(splitname, sizeof(splitname), "%D", i);CHKERRQ(ierr); 356 ierr = PCFieldSplitSetIS(pc, splitname, compField);CHKERRQ(ierr); 357 /* ierr = PetscPrintf(PetscObjectComm((PetscObject)pc), "%s Field Indices:", splitname);CHKERRQ(ierr); 358 ierr = ISView(compField, NULL);CHKERRQ(ierr); */ 359 } 360 ierr = ISDestroy(&compField);CHKERRQ(ierr); 361 for (j = 0; j < nfields; ++j) { 362 f = ifields[j]; 363 ierr = PetscFree(fieldNames[f]);CHKERRQ(ierr); 364 ierr = ISDestroy(&fields[f]);CHKERRQ(ierr); 365 } 366 } 367 if (i == 0) { 368 for (f = 0; f < numFields; ++f) { 369 ierr = PCFieldSplitSetIS(pc, fieldNames[f], fields[f]);CHKERRQ(ierr); 370 ierr = PetscFree(fieldNames[f]);CHKERRQ(ierr); 371 ierr = ISDestroy(&fields[f]);CHKERRQ(ierr); 372 } 373 } else { 374 for (j=0; j<numFields; j++) { 375 ierr = DMDestroy(dms+j);CHKERRQ(ierr); 376 } 377 ierr = PetscFree(dms);CHKERRQ(ierr); 378 ierr = PetscMalloc1(i, &dms);CHKERRQ(ierr); 379 for (j = 0; j < i; ++j) dms[j] = subdm[j]; 380 } 381 ierr = PetscFree(fieldNames);CHKERRQ(ierr); 382 ierr = PetscFree(fields);CHKERRQ(ierr); 383 if (dms) { 384 ierr = PetscInfo(pc, "Setting up physics based fieldsplit preconditioner using the embedded DM\n");CHKERRQ(ierr); 385 for (ilink = jac->head, i = 0; ilink; ilink = ilink->next, ++i) { 386 const char *prefix; 387 ierr = PetscObjectGetOptionsPrefix((PetscObject)(ilink->ksp),&prefix);CHKERRQ(ierr); 388 ierr = PetscObjectSetOptionsPrefix((PetscObject)(dms[i]), prefix);CHKERRQ(ierr); 389 ierr = KSPSetDM(ilink->ksp, dms[i]);CHKERRQ(ierr); 390 ierr = KSPSetDMActive(ilink->ksp, PETSC_FALSE);CHKERRQ(ierr); 391 ierr = PetscObjectIncrementTabLevel((PetscObject)dms[i],(PetscObject)ilink->ksp,0);CHKERRQ(ierr); 392 ierr = DMDestroy(&dms[i]);CHKERRQ(ierr); 393 } 394 ierr = PetscFree(dms);CHKERRQ(ierr); 395 } 396 } else { 397 if (jac->bs <= 0) { 398 if (pc->pmat) { 399 ierr = MatGetBlockSize(pc->pmat,&jac->bs);CHKERRQ(ierr); 400 } else jac->bs = 1; 401 } 402 403 if (stokes) { 404 IS zerodiags,rest; 405 PetscInt nmin,nmax; 406 407 ierr = MatGetOwnershipRange(pc->mat,&nmin,&nmax);CHKERRQ(ierr); 408 ierr = MatFindZeroDiagonals(pc->mat,&zerodiags);CHKERRQ(ierr); 409 ierr = ISComplement(zerodiags,nmin,nmax,&rest);CHKERRQ(ierr); 410 if (jac->reset) { 411 jac->head->is = rest; 412 jac->head->next->is = zerodiags; 413 } else { 414 ierr = PCFieldSplitSetIS(pc,"0",rest);CHKERRQ(ierr); 415 ierr = PCFieldSplitSetIS(pc,"1",zerodiags);CHKERRQ(ierr); 416 } 417 ierr = ISDestroy(&zerodiags);CHKERRQ(ierr); 418 ierr = ISDestroy(&rest);CHKERRQ(ierr); 419 } else if (coupling) { 420 IS coupling,rest; 421 PetscInt nmin,nmax; 422 423 ierr = MatGetOwnershipRange(pc->mat,&nmin,&nmax);CHKERRQ(ierr); 424 ierr = MatFindOffBlockDiagonalEntries(pc->mat,&coupling);CHKERRQ(ierr); 425 ierr = ISCreateStride(PetscObjectComm((PetscObject)pc->mat),nmax-nmin,nmin,1,&rest);CHKERRQ(ierr); 426 ierr = ISSetIdentity(rest);CHKERRQ(ierr); 427 if (jac->reset) { 428 jac->head->is = coupling; 429 jac->head->next->is = rest; 430 } else { 431 ierr = PCFieldSplitSetIS(pc,"0",coupling);CHKERRQ(ierr); 432 ierr = PCFieldSplitSetIS(pc,"1",rest);CHKERRQ(ierr); 433 } 434 ierr = ISDestroy(&coupling);CHKERRQ(ierr); 435 ierr = ISDestroy(&rest);CHKERRQ(ierr); 436 } else { 437 if (jac->reset) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cases not yet handled when PCReset() was used"); 438 ierr = PetscOptionsGetBool(((PetscObject)pc)->prefix,"-pc_fieldsplit_default",&fieldsplit_default,NULL);CHKERRQ(ierr); 439 if (!fieldsplit_default) { 440 /* Allow user to set fields from command line, if bs was known at the time of PCSetFromOptions_FieldSplit() 441 then it is set there. This is not ideal because we should only have options set in XXSetFromOptions(). */ 442 ierr = PCFieldSplitSetRuntimeSplits_Private(pc);CHKERRQ(ierr); 443 if (jac->splitdefined) {ierr = PetscInfo(pc,"Splits defined using the options database\n");CHKERRQ(ierr);} 444 } 445 if (fieldsplit_default || !jac->splitdefined) { 446 ierr = PetscInfo(pc,"Using default splitting of fields\n");CHKERRQ(ierr); 447 for (i=0; i<jac->bs; i++) { 448 char splitname[8]; 449 ierr = PetscSNPrintf(splitname,sizeof(splitname),"%D",i);CHKERRQ(ierr); 450 ierr = PCFieldSplitSetFields(pc,splitname,1,&i,&i);CHKERRQ(ierr); 451 } 452 jac->defaultsplit = PETSC_TRUE; 453 } 454 } 455 } 456 } else if (jac->nsplits == 1) { 457 if (ilink->is) { 458 IS is2; 459 PetscInt nmin,nmax; 460 461 ierr = MatGetOwnershipRange(pc->mat,&nmin,&nmax);CHKERRQ(ierr); 462 ierr = ISComplement(ilink->is,nmin,nmax,&is2);CHKERRQ(ierr); 463 ierr = PCFieldSplitSetIS(pc,"1",is2);CHKERRQ(ierr); 464 ierr = ISDestroy(&is2);CHKERRQ(ierr); 465 } else SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Must provide at least two sets of fields to PCFieldSplit()"); 466 } 467 468 469 if (jac->nsplits < 2) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_PLIB,"Unhandled case, must have at least two fields, not %d", jac->nsplits); 470 PetscFunctionReturn(0); 471 } 472 473 PETSC_EXTERN PetscErrorCode PetscOptionsFindPairPrefix_Private(const char pre[], const char name[], char *value[], PetscBool *flg); 474 475 #undef __FUNCT__ 476 #define __FUNCT__ "PCSetUp_FieldSplit" 477 static PetscErrorCode PCSetUp_FieldSplit(PC pc) 478 { 479 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 480 PetscErrorCode ierr; 481 PC_FieldSplitLink ilink; 482 PetscInt i,nsplit; 483 PetscBool sorted, sorted_col; 484 485 PetscFunctionBegin; 486 ierr = PCFieldSplitSetDefaults(pc);CHKERRQ(ierr); 487 nsplit = jac->nsplits; 488 ilink = jac->head; 489 490 /* get the matrices for each split */ 491 if (!jac->issetup) { 492 PetscInt rstart,rend,nslots,bs; 493 494 jac->issetup = PETSC_TRUE; 495 496 /* This is done here instead of in PCFieldSplitSetFields() because may not have matrix at that point */ 497 if (jac->defaultsplit || !ilink->is) { 498 if (jac->bs <= 0) jac->bs = nsplit; 499 } 500 bs = jac->bs; 501 ierr = MatGetOwnershipRange(pc->pmat,&rstart,&rend);CHKERRQ(ierr); 502 nslots = (rend - rstart)/bs; 503 for (i=0; i<nsplit; i++) { 504 if (jac->defaultsplit) { 505 ierr = ISCreateStride(PetscObjectComm((PetscObject)pc),nslots,rstart+i,nsplit,&ilink->is);CHKERRQ(ierr); 506 ierr = ISDuplicate(ilink->is,&ilink->is_col);CHKERRQ(ierr); 507 } else if (!ilink->is) { 508 if (ilink->nfields > 1) { 509 PetscInt *ii,*jj,j,k,nfields = ilink->nfields,*fields = ilink->fields,*fields_col = ilink->fields_col; 510 ierr = PetscMalloc1(ilink->nfields*nslots,&ii);CHKERRQ(ierr); 511 ierr = PetscMalloc1(ilink->nfields*nslots,&jj);CHKERRQ(ierr); 512 for (j=0; j<nslots; j++) { 513 for (k=0; k<nfields; k++) { 514 ii[nfields*j + k] = rstart + bs*j + fields[k]; 515 jj[nfields*j + k] = rstart + bs*j + fields_col[k]; 516 } 517 } 518 ierr = ISCreateGeneral(PetscObjectComm((PetscObject)pc),nslots*nfields,ii,PETSC_OWN_POINTER,&ilink->is);CHKERRQ(ierr); 519 ierr = ISCreateGeneral(PetscObjectComm((PetscObject)pc),nslots*nfields,jj,PETSC_OWN_POINTER,&ilink->is_col);CHKERRQ(ierr); 520 } else { 521 ierr = ISCreateStride(PetscObjectComm((PetscObject)pc),nslots,rstart+ilink->fields[0],bs,&ilink->is);CHKERRQ(ierr); 522 ierr = ISCreateStride(PetscObjectComm((PetscObject)pc),nslots,rstart+ilink->fields_col[0],bs,&ilink->is_col);CHKERRQ(ierr); 523 } 524 } 525 ierr = ISSorted(ilink->is,&sorted);CHKERRQ(ierr); 526 if (ilink->is_col) { ierr = ISSorted(ilink->is_col,&sorted_col);CHKERRQ(ierr); } 527 if (!sorted || !sorted_col) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Fields must be sorted when creating split"); 528 ilink = ilink->next; 529 } 530 } 531 532 ilink = jac->head; 533 if (!jac->pmat) { 534 Vec xtmp; 535 536 ierr = MatCreateVecs(pc->pmat,&xtmp,NULL);CHKERRQ(ierr); 537 ierr = PetscMalloc1(nsplit,&jac->pmat);CHKERRQ(ierr); 538 ierr = PetscMalloc2(nsplit,&jac->x,nsplit,&jac->y);CHKERRQ(ierr); 539 for (i=0; i<nsplit; i++) { 540 MatNullSpace sp; 541 542 /* Check for preconditioning matrix attached to IS */ 543 ierr = PetscObjectQuery((PetscObject) ilink->is, "pmat", (PetscObject*) &jac->pmat[i]);CHKERRQ(ierr); 544 if (jac->pmat[i]) { 545 ierr = PetscObjectReference((PetscObject) jac->pmat[i]);CHKERRQ(ierr); 546 if (jac->type == PC_COMPOSITE_SCHUR) { 547 jac->schur_user = jac->pmat[i]; 548 549 ierr = PetscObjectReference((PetscObject) jac->schur_user);CHKERRQ(ierr); 550 } 551 } else { 552 const char *prefix; 553 ierr = MatGetSubMatrix(pc->pmat,ilink->is,ilink->is_col,MAT_INITIAL_MATRIX,&jac->pmat[i]);CHKERRQ(ierr); 554 ierr = KSPGetOptionsPrefix(ilink->ksp,&prefix);CHKERRQ(ierr); 555 ierr = MatSetOptionsPrefix(jac->pmat[i],prefix);CHKERRQ(ierr); 556 ierr = MatViewFromOptions(jac->pmat[i],NULL,"-mat_view");CHKERRQ(ierr); 557 } 558 /* create work vectors for each split */ 559 ierr = MatCreateVecs(jac->pmat[i],&jac->x[i],&jac->y[i]);CHKERRQ(ierr); 560 ilink->x = jac->x[i]; ilink->y = jac->y[i]; ilink->z = NULL; 561 /* compute scatter contexts needed by multiplicative versions and non-default splits */ 562 ierr = VecScatterCreate(xtmp,ilink->is,jac->x[i],NULL,&ilink->sctx);CHKERRQ(ierr); 563 /* Check for null space attached to IS */ 564 ierr = PetscObjectQuery((PetscObject) ilink->is, "nullspace", (PetscObject*) &sp);CHKERRQ(ierr); 565 if (sp) { 566 ierr = MatSetNullSpace(jac->pmat[i], sp);CHKERRQ(ierr); 567 } 568 ierr = PetscObjectQuery((PetscObject) ilink->is, "nearnullspace", (PetscObject*) &sp);CHKERRQ(ierr); 569 if (sp) { 570 ierr = MatSetNearNullSpace(jac->pmat[i], sp);CHKERRQ(ierr); 571 } 572 ilink = ilink->next; 573 } 574 ierr = VecDestroy(&xtmp);CHKERRQ(ierr); 575 } else { 576 for (i=0; i<nsplit; i++) { 577 Mat pmat; 578 579 /* Check for preconditioning matrix attached to IS */ 580 ierr = PetscObjectQuery((PetscObject) ilink->is, "pmat", (PetscObject*) &pmat);CHKERRQ(ierr); 581 if (!pmat) { 582 ierr = MatGetSubMatrix(pc->pmat,ilink->is,ilink->is_col,MAT_REUSE_MATRIX,&jac->pmat[i]);CHKERRQ(ierr); 583 } 584 ilink = ilink->next; 585 } 586 } 587 if (jac->diag_use_amat) { 588 ilink = jac->head; 589 if (!jac->mat) { 590 ierr = PetscMalloc1(nsplit,&jac->mat);CHKERRQ(ierr); 591 for (i=0; i<nsplit; i++) { 592 ierr = MatGetSubMatrix(pc->mat,ilink->is,ilink->is_col,MAT_INITIAL_MATRIX,&jac->mat[i]);CHKERRQ(ierr); 593 ilink = ilink->next; 594 } 595 } else { 596 for (i=0; i<nsplit; i++) { 597 if (jac->mat[i]) {ierr = MatGetSubMatrix(pc->mat,ilink->is,ilink->is_col,MAT_REUSE_MATRIX,&jac->mat[i]);CHKERRQ(ierr);} 598 ilink = ilink->next; 599 } 600 } 601 } else { 602 jac->mat = jac->pmat; 603 } 604 605 if (jac->type != PC_COMPOSITE_ADDITIVE && jac->type != PC_COMPOSITE_SCHUR) { 606 /* extract the rows of the matrix associated with each field: used for efficient computation of residual inside algorithm */ 607 /* FIXME: Can/should we reuse jac->mat whenever (jac->diag_use_amat) is true? */ 608 ilink = jac->head; 609 if (nsplit == 2 && jac->type == PC_COMPOSITE_MULTIPLICATIVE) { 610 /* special case need where Afield[0] is not needed and only certain columns of Afield[1] are needed since update is only on those rows of the solution */ 611 if (!jac->Afield) { 612 ierr = PetscCalloc1(nsplit,&jac->Afield);CHKERRQ(ierr); 613 ierr = MatGetSubMatrix(pc->mat,ilink->next->is,ilink->is,MAT_INITIAL_MATRIX,&jac->Afield[1]);CHKERRQ(ierr); 614 } else { 615 ierr = MatGetSubMatrix(pc->mat,ilink->next->is,ilink->is,MAT_REUSE_MATRIX,&jac->Afield[1]);CHKERRQ(ierr); 616 } 617 } else { 618 if (!jac->Afield) { 619 ierr = PetscMalloc1(nsplit,&jac->Afield);CHKERRQ(ierr); 620 for (i=0; i<nsplit; i++) { 621 ierr = MatGetSubMatrix(pc->mat,ilink->is,NULL,MAT_INITIAL_MATRIX,&jac->Afield[i]);CHKERRQ(ierr); 622 ilink = ilink->next; 623 } 624 } else { 625 for (i=0; i<nsplit; i++) { 626 ierr = MatGetSubMatrix(pc->mat,ilink->is,NULL,MAT_REUSE_MATRIX,&jac->Afield[i]);CHKERRQ(ierr); 627 ilink = ilink->next; 628 } 629 } 630 } 631 } 632 633 if (jac->type == PC_COMPOSITE_SCHUR) { 634 IS ccis; 635 PetscInt rstart,rend; 636 char lscname[256]; 637 PetscObject LSC_L; 638 639 if (nsplit != 2) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_INCOMP,"To use Schur complement preconditioner you must have exactly 2 fields"); 640 641 /* When extracting off-diagonal submatrices, we take complements from this range */ 642 ierr = MatGetOwnershipRangeColumn(pc->mat,&rstart,&rend);CHKERRQ(ierr); 643 644 /* need to handle case when one is resetting up the preconditioner */ 645 if (jac->schur) { 646 KSP kspA = jac->head->ksp, kspInner = NULL, kspUpper = jac->kspupper; 647 648 ierr = MatSchurComplementGetKSP(jac->schur, &kspInner);CHKERRQ(ierr); 649 ilink = jac->head; 650 ierr = ISComplement(ilink->is_col,rstart,rend,&ccis);CHKERRQ(ierr); 651 if (jac->offdiag_use_amat) { 652 ierr = MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->B);CHKERRQ(ierr); 653 } else { 654 ierr = MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->B);CHKERRQ(ierr); 655 } 656 ierr = ISDestroy(&ccis);CHKERRQ(ierr); 657 ilink = ilink->next; 658 ierr = ISComplement(ilink->is_col,rstart,rend,&ccis);CHKERRQ(ierr); 659 if (jac->offdiag_use_amat) { 660 ierr = MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->C);CHKERRQ(ierr); 661 } else { 662 ierr = MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->C);CHKERRQ(ierr); 663 } 664 ierr = ISDestroy(&ccis);CHKERRQ(ierr); 665 ierr = MatSchurComplementUpdateSubMatrices(jac->schur,jac->mat[0],jac->pmat[0],jac->B,jac->C,jac->mat[1]);CHKERRQ(ierr); 666 if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_SELFP) { 667 ierr = MatDestroy(&jac->schurp);CHKERRQ(ierr); 668 ierr = MatSchurComplementGetPmat(jac->schur,MAT_INITIAL_MATRIX,&jac->schurp);CHKERRQ(ierr); 669 } 670 if (kspA != kspInner) { 671 ierr = KSPSetOperators(kspA,jac->mat[0],jac->pmat[0]);CHKERRQ(ierr); 672 } 673 if (kspUpper != kspA) { 674 ierr = KSPSetOperators(kspUpper,jac->mat[0],jac->pmat[0]);CHKERRQ(ierr); 675 } 676 ierr = KSPSetOperators(jac->kspschur,jac->schur,FieldSplitSchurPre(jac));CHKERRQ(ierr); 677 } else { 678 const char *Dprefix; 679 char schurprefix[256], schurmatprefix[256]; 680 char schurtestoption[256]; 681 MatNullSpace sp; 682 PetscBool flg; 683 684 /* extract the A01 and A10 matrices */ 685 ilink = jac->head; 686 ierr = ISComplement(ilink->is_col,rstart,rend,&ccis);CHKERRQ(ierr); 687 if (jac->offdiag_use_amat) { 688 ierr = MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->B);CHKERRQ(ierr); 689 } else { 690 ierr = MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->B);CHKERRQ(ierr); 691 } 692 ierr = ISDestroy(&ccis);CHKERRQ(ierr); 693 ilink = ilink->next; 694 ierr = ISComplement(ilink->is_col,rstart,rend,&ccis);CHKERRQ(ierr); 695 if (jac->offdiag_use_amat) { 696 ierr = MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->C);CHKERRQ(ierr); 697 } else { 698 ierr = MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->C);CHKERRQ(ierr); 699 } 700 ierr = ISDestroy(&ccis);CHKERRQ(ierr); 701 702 /* Use mat[0] (diagonal block of Amat) preconditioned by pmat[0] to define Schur complement */ 703 ierr = MatCreate(((PetscObject)jac->mat[0])->comm,&jac->schur);CHKERRQ(ierr); 704 ierr = MatSetType(jac->schur,MATSCHURCOMPLEMENT);CHKERRQ(ierr); 705 ierr = MatSchurComplementSetSubMatrices(jac->schur,jac->mat[0],jac->pmat[0],jac->B,jac->C,jac->mat[1]);CHKERRQ(ierr); 706 ierr = PetscSNPrintf(schurmatprefix, sizeof(schurmatprefix), "%sfieldsplit_%s_", ((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "", ilink->splitname);CHKERRQ(ierr); 707 /* Note that the inner KSP is NOT going to inherit this prefix, and if it did, it would be reset just below. Is that what we want? */ 708 ierr = MatSetOptionsPrefix(jac->schur,schurmatprefix);CHKERRQ(ierr); 709 ierr = MatSetFromOptions(jac->schur);CHKERRQ(ierr); 710 ierr = MatGetNullSpace(jac->pmat[1], &sp);CHKERRQ(ierr); 711 if (sp) { 712 ierr = MatSetNullSpace(jac->schur, sp);CHKERRQ(ierr); 713 } 714 715 ierr = PetscSNPrintf(schurtestoption, sizeof(schurtestoption), "-fieldsplit_%s_inner_", ilink->splitname);CHKERRQ(ierr); 716 ierr = PetscOptionsFindPairPrefix_Private(((PetscObject)pc)->prefix, schurtestoption, NULL, &flg);CHKERRQ(ierr); 717 if (flg) { 718 DM dmInner; 719 KSP kspInner; 720 721 ierr = MatSchurComplementGetKSP(jac->schur, &kspInner);CHKERRQ(ierr); 722 ierr = PetscSNPrintf(schurprefix, sizeof(schurprefix), "%sfieldsplit_%s_inner_", ((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "", ilink->splitname);CHKERRQ(ierr); 723 /* Indent this deeper to emphasize the "inner" nature of this solver. */ 724 ierr = PetscObjectIncrementTabLevel((PetscObject)kspInner, (PetscObject) pc, 2);CHKERRQ(ierr); 725 ierr = KSPSetOptionsPrefix(kspInner, schurprefix);CHKERRQ(ierr); 726 727 /* Set DM for new solver */ 728 ierr = KSPGetDM(jac->head->ksp, &dmInner);CHKERRQ(ierr); 729 ierr = KSPSetDM(kspInner, dmInner);CHKERRQ(ierr); 730 ierr = KSPSetDMActive(kspInner, PETSC_FALSE);CHKERRQ(ierr); 731 } else { 732 /* Use the outer solver for the inner solve, but revert the KSPPREONLY from PCFieldSplitSetFields_FieldSplit or 733 * PCFieldSplitSetIS_FieldSplit. We don't want KSPPREONLY because it makes the Schur complement inexact, 734 * preventing Schur complement reduction to be an accurate solve. Usually when an iterative solver is used for 735 * S = D - C A_inner^{-1} B, we expect S to be defined using an accurate definition of A_inner^{-1}, so we make 736 * GMRES the default. Note that it is also common to use PREONLY for S, in which case S may not be used 737 * directly, and the user is responsible for setting an inexact method for fieldsplit's A^{-1}. */ 738 ierr = KSPSetType(jac->head->ksp,KSPGMRES);CHKERRQ(ierr); 739 ierr = MatSchurComplementSetKSP(jac->schur,jac->head->ksp);CHKERRQ(ierr); 740 } 741 ierr = KSPSetOperators(jac->head->ksp,jac->mat[0],jac->pmat[0]);CHKERRQ(ierr); 742 ierr = KSPSetFromOptions(jac->head->ksp);CHKERRQ(ierr); 743 ierr = MatSetFromOptions(jac->schur);CHKERRQ(ierr); 744 745 ierr = PetscSNPrintf(schurtestoption, sizeof(schurtestoption), "-fieldsplit_%s_upper_", ilink->splitname);CHKERRQ(ierr); 746 ierr = PetscOptionsFindPairPrefix_Private(((PetscObject)pc)->prefix, schurtestoption, NULL, &flg);CHKERRQ(ierr); 747 if (flg) { 748 DM dmInner; 749 750 ierr = PetscSNPrintf(schurprefix, sizeof(schurprefix), "%sfieldsplit_%s_upper_", ((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "", ilink->splitname);CHKERRQ(ierr); 751 ierr = KSPCreate(PetscObjectComm((PetscObject)pc), &jac->kspupper);CHKERRQ(ierr); 752 ierr = KSPSetOptionsPrefix(jac->kspupper, schurprefix);CHKERRQ(ierr); 753 ierr = KSPGetDM(jac->head->ksp, &dmInner);CHKERRQ(ierr); 754 ierr = KSPSetDM(jac->kspupper, dmInner);CHKERRQ(ierr); 755 ierr = KSPSetDMActive(jac->kspupper, PETSC_FALSE);CHKERRQ(ierr); 756 ierr = KSPSetFromOptions(jac->kspupper);CHKERRQ(ierr); 757 ierr = KSPSetOperators(jac->kspupper,jac->mat[0],jac->pmat[0]);CHKERRQ(ierr); 758 ierr = VecDuplicate(jac->head->x, &jac->head->z);CHKERRQ(ierr); 759 } else { 760 jac->kspupper = jac->head->ksp; 761 ierr = PetscObjectReference((PetscObject) jac->head->ksp);CHKERRQ(ierr); 762 } 763 764 if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_SELFP) { 765 ierr = MatSchurComplementGetPmat(jac->schur,MAT_INITIAL_MATRIX,&jac->schurp);CHKERRQ(ierr); 766 } 767 ierr = KSPCreate(PetscObjectComm((PetscObject)pc),&jac->kspschur);CHKERRQ(ierr); 768 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)jac->kspschur);CHKERRQ(ierr); 769 ierr = PetscObjectIncrementTabLevel((PetscObject)jac->kspschur,(PetscObject)pc,1);CHKERRQ(ierr); 770 if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_SELF) { 771 PC pcschur; 772 ierr = KSPGetPC(jac->kspschur,&pcschur);CHKERRQ(ierr); 773 ierr = PCSetType(pcschur,PCNONE);CHKERRQ(ierr); 774 /* Note: This is bad if there exist preconditioners for MATSCHURCOMPLEMENT */ 775 } else if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_FULL) { 776 ierr = MatSchurComplementComputeExplicitOperator(jac->schur, &jac->schur_user);CHKERRQ(ierr); 777 } 778 ierr = KSPSetOperators(jac->kspschur,jac->schur,FieldSplitSchurPre(jac));CHKERRQ(ierr); 779 ierr = KSPGetOptionsPrefix(jac->head->next->ksp, &Dprefix);CHKERRQ(ierr); 780 ierr = KSPSetOptionsPrefix(jac->kspschur, Dprefix);CHKERRQ(ierr); 781 /* propogate DM */ 782 { 783 DM sdm; 784 ierr = KSPGetDM(jac->head->next->ksp, &sdm);CHKERRQ(ierr); 785 if (sdm) { 786 ierr = KSPSetDM(jac->kspschur, sdm);CHKERRQ(ierr); 787 ierr = KSPSetDMActive(jac->kspschur, PETSC_FALSE);CHKERRQ(ierr); 788 } 789 } 790 /* really want setfromoptions called in PCSetFromOptions_FieldSplit(), but it is not ready yet */ 791 /* need to call this every time, since the jac->kspschur is freshly created, otherwise its options never get set */ 792 ierr = KSPSetFromOptions(jac->kspschur);CHKERRQ(ierr); 793 } 794 795 /* HACK: special support to forward L and Lp matrices that might be used by PCLSC */ 796 ierr = PetscSNPrintf(lscname,sizeof(lscname),"%s_LSC_L",ilink->splitname);CHKERRQ(ierr); 797 ierr = PetscObjectQuery((PetscObject)pc->mat,lscname,(PetscObject*)&LSC_L);CHKERRQ(ierr); 798 if (!LSC_L) {ierr = PetscObjectQuery((PetscObject)pc->pmat,lscname,(PetscObject*)&LSC_L);CHKERRQ(ierr);} 799 if (LSC_L) {ierr = PetscObjectCompose((PetscObject)jac->schur,"LSC_L",(PetscObject)LSC_L);CHKERRQ(ierr);} 800 ierr = PetscSNPrintf(lscname,sizeof(lscname),"%s_LSC_Lp",ilink->splitname);CHKERRQ(ierr); 801 ierr = PetscObjectQuery((PetscObject)pc->pmat,lscname,(PetscObject*)&LSC_L);CHKERRQ(ierr); 802 if (!LSC_L) {ierr = PetscObjectQuery((PetscObject)pc->mat,lscname,(PetscObject*)&LSC_L);CHKERRQ(ierr);} 803 if (LSC_L) {ierr = PetscObjectCompose((PetscObject)jac->schur,"LSC_Lp",(PetscObject)LSC_L);CHKERRQ(ierr);} 804 } else { 805 /* set up the individual splits' PCs */ 806 i = 0; 807 ilink = jac->head; 808 while (ilink) { 809 ierr = KSPSetOperators(ilink->ksp,jac->mat[i],jac->pmat[i]);CHKERRQ(ierr); 810 /* really want setfromoptions called in PCSetFromOptions_FieldSplit(), but it is not ready yet */ 811 if (!jac->suboptionsset) {ierr = KSPSetFromOptions(ilink->ksp);CHKERRQ(ierr);} 812 i++; 813 ilink = ilink->next; 814 } 815 } 816 817 jac->suboptionsset = PETSC_TRUE; 818 PetscFunctionReturn(0); 819 } 820 821 #define FieldSplitSplitSolveAdd(ilink,xx,yy) \ 822 (VecScatterBegin(ilink->sctx,xx,ilink->x,INSERT_VALUES,SCATTER_FORWARD) || \ 823 VecScatterEnd(ilink->sctx,xx,ilink->x,INSERT_VALUES,SCATTER_FORWARD) || \ 824 KSPSolve(ilink->ksp,ilink->x,ilink->y) || \ 825 VecScatterBegin(ilink->sctx,ilink->y,yy,ADD_VALUES,SCATTER_REVERSE) || \ 826 VecScatterEnd(ilink->sctx,ilink->y,yy,ADD_VALUES,SCATTER_REVERSE)) 827 828 #undef __FUNCT__ 829 #define __FUNCT__ "PCApply_FieldSplit_Schur" 830 static PetscErrorCode PCApply_FieldSplit_Schur(PC pc,Vec x,Vec y) 831 { 832 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 833 PetscErrorCode ierr; 834 PC_FieldSplitLink ilinkA = jac->head, ilinkD = ilinkA->next; 835 KSP kspA = ilinkA->ksp, kspLower = kspA, kspUpper = jac->kspupper; 836 837 PetscFunctionBegin; 838 switch (jac->schurfactorization) { 839 case PC_FIELDSPLIT_SCHUR_FACT_DIAG: 840 /* [A00 0; 0 -S], positive definite, suitable for MINRES */ 841 ierr = VecScatterBegin(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 842 ierr = VecScatterBegin(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 843 ierr = VecScatterEnd(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 844 ierr = KSPSolve(kspA,ilinkA->x,ilinkA->y);CHKERRQ(ierr); 845 ierr = VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 846 ierr = VecScatterEnd(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 847 ierr = KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);CHKERRQ(ierr); 848 ierr = VecScale(ilinkD->y,-1.);CHKERRQ(ierr); 849 ierr = VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 850 ierr = VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 851 ierr = VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 852 break; 853 case PC_FIELDSPLIT_SCHUR_FACT_LOWER: 854 /* [A00 0; A10 S], suitable for left preconditioning */ 855 ierr = VecScatterBegin(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 856 ierr = VecScatterEnd(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 857 ierr = KSPSolve(kspA,ilinkA->x,ilinkA->y);CHKERRQ(ierr); 858 ierr = MatMult(jac->C,ilinkA->y,ilinkD->x);CHKERRQ(ierr); 859 ierr = VecScale(ilinkD->x,-1.);CHKERRQ(ierr); 860 ierr = VecScatterBegin(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 861 ierr = VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 862 ierr = VecScatterEnd(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 863 ierr = KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);CHKERRQ(ierr); 864 ierr = VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 865 ierr = VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 866 ierr = VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 867 break; 868 case PC_FIELDSPLIT_SCHUR_FACT_UPPER: 869 /* [A00 A01; 0 S], suitable for right preconditioning */ 870 ierr = VecScatterBegin(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 871 ierr = VecScatterEnd(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 872 ierr = KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);CHKERRQ(ierr); 873 ierr = MatMult(jac->B,ilinkD->y,ilinkA->x);CHKERRQ(ierr); 874 ierr = VecScale(ilinkA->x,-1.);CHKERRQ(ierr); 875 ierr = VecScatterBegin(ilinkA->sctx,x,ilinkA->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 876 ierr = VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 877 ierr = VecScatterEnd(ilinkA->sctx,x,ilinkA->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 878 ierr = KSPSolve(kspA,ilinkA->x,ilinkA->y);CHKERRQ(ierr); 879 ierr = VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 880 ierr = VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 881 ierr = VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 882 break; 883 case PC_FIELDSPLIT_SCHUR_FACT_FULL: 884 /* [1 0; A10 A00^{-1} 1] [A00 0; 0 S] [1 A00^{-1}A01; 0 1], an exact solve if applied exactly, needs one extra solve with A */ 885 ierr = VecScatterBegin(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 886 ierr = VecScatterEnd(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 887 ierr = KSPSolve(kspLower,ilinkA->x,ilinkA->y);CHKERRQ(ierr); 888 ierr = MatMult(jac->C,ilinkA->y,ilinkD->x);CHKERRQ(ierr); 889 ierr = VecScale(ilinkD->x,-1.0);CHKERRQ(ierr); 890 ierr = VecScatterBegin(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 891 ierr = VecScatterEnd(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 892 893 ierr = KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);CHKERRQ(ierr); 894 ierr = VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 895 ierr = VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 896 897 if (kspUpper == kspA) { 898 ierr = MatMult(jac->B,ilinkD->y,ilinkA->y);CHKERRQ(ierr); 899 ierr = VecAXPY(ilinkA->x,-1.0,ilinkA->y);CHKERRQ(ierr); 900 ierr = KSPSolve(kspA,ilinkA->x,ilinkA->y);CHKERRQ(ierr); 901 } else { 902 ierr = KSPSolve(kspA,ilinkA->x,ilinkA->y);CHKERRQ(ierr); 903 ierr = MatMult(jac->B,ilinkD->y,ilinkA->x);CHKERRQ(ierr); 904 ierr = KSPSolve(kspUpper,ilinkA->x,ilinkA->z);CHKERRQ(ierr); 905 ierr = VecAXPY(ilinkA->y,-1.0,ilinkA->z);CHKERRQ(ierr); 906 } 907 ierr = VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 908 ierr = VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 909 } 910 PetscFunctionReturn(0); 911 } 912 913 #undef __FUNCT__ 914 #define __FUNCT__ "PCApply_FieldSplit" 915 static PetscErrorCode PCApply_FieldSplit(PC pc,Vec x,Vec y) 916 { 917 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 918 PetscErrorCode ierr; 919 PC_FieldSplitLink ilink = jac->head; 920 PetscInt cnt,bs; 921 922 PetscFunctionBegin; 923 if (jac->type == PC_COMPOSITE_ADDITIVE) { 924 if (jac->defaultsplit) { 925 ierr = VecGetBlockSize(x,&bs);CHKERRQ(ierr); 926 if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of x vector %D does not match fieldsplit blocksize %D",bs,jac->bs); 927 ierr = VecGetBlockSize(y,&bs);CHKERRQ(ierr); 928 if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of y vector %D does not match fieldsplit blocksize %D",bs,jac->bs); 929 ierr = VecStrideGatherAll(x,jac->x,INSERT_VALUES);CHKERRQ(ierr); 930 while (ilink) { 931 ierr = KSPSolve(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr); 932 ilink = ilink->next; 933 } 934 ierr = VecStrideScatterAll(jac->y,y,INSERT_VALUES);CHKERRQ(ierr); 935 } else { 936 ierr = VecSet(y,0.0);CHKERRQ(ierr); 937 while (ilink) { 938 ierr = FieldSplitSplitSolveAdd(ilink,x,y);CHKERRQ(ierr); 939 ilink = ilink->next; 940 } 941 } 942 } else if (jac->type == PC_COMPOSITE_MULTIPLICATIVE && jac->nsplits == 2) { 943 ierr = VecSet(y,0.0);CHKERRQ(ierr); 944 /* solve on first block for first block variables */ 945 ierr = VecScatterBegin(ilink->sctx,x,ilink->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 946 ierr = VecScatterEnd(ilink->sctx,x,ilink->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 947 ierr = KSPSolve(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr); 948 ierr = VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 949 ierr = VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 950 951 /* compute the residual only onto second block variables using first block variables */ 952 ierr = MatMult(jac->Afield[1],ilink->y,ilink->next->x);CHKERRQ(ierr); 953 ilink = ilink->next; 954 ierr = VecScale(ilink->x,-1.0);CHKERRQ(ierr); 955 ierr = VecScatterBegin(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 956 ierr = VecScatterEnd(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 957 958 /* solve on second block variables */ 959 ierr = KSPSolve(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr); 960 ierr = VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 961 ierr = VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 962 } else if (jac->type == PC_COMPOSITE_MULTIPLICATIVE || jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) { 963 if (!jac->w1) { 964 ierr = VecDuplicate(x,&jac->w1);CHKERRQ(ierr); 965 ierr = VecDuplicate(x,&jac->w2);CHKERRQ(ierr); 966 } 967 ierr = VecSet(y,0.0);CHKERRQ(ierr); 968 ierr = FieldSplitSplitSolveAdd(ilink,x,y);CHKERRQ(ierr); 969 cnt = 1; 970 while (ilink->next) { 971 ilink = ilink->next; 972 /* compute the residual only over the part of the vector needed */ 973 ierr = MatMult(jac->Afield[cnt++],y,ilink->x);CHKERRQ(ierr); 974 ierr = VecScale(ilink->x,-1.0);CHKERRQ(ierr); 975 ierr = VecScatterBegin(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 976 ierr = VecScatterEnd(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 977 ierr = KSPSolve(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr); 978 ierr = VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 979 ierr = VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 980 } 981 if (jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) { 982 cnt -= 2; 983 while (ilink->previous) { 984 ilink = ilink->previous; 985 /* compute the residual only over the part of the vector needed */ 986 ierr = MatMult(jac->Afield[cnt--],y,ilink->x);CHKERRQ(ierr); 987 ierr = VecScale(ilink->x,-1.0);CHKERRQ(ierr); 988 ierr = VecScatterBegin(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 989 ierr = VecScatterEnd(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 990 ierr = KSPSolve(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr); 991 ierr = VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 992 ierr = VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 993 } 994 } 995 } else SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Unsupported or unknown composition",(int) jac->type); 996 PetscFunctionReturn(0); 997 } 998 999 #define FieldSplitSplitSolveAddTranspose(ilink,xx,yy) \ 1000 (VecScatterBegin(ilink->sctx,xx,ilink->y,INSERT_VALUES,SCATTER_FORWARD) || \ 1001 VecScatterEnd(ilink->sctx,xx,ilink->y,INSERT_VALUES,SCATTER_FORWARD) || \ 1002 KSPSolveTranspose(ilink->ksp,ilink->y,ilink->x) || \ 1003 VecScatterBegin(ilink->sctx,ilink->x,yy,ADD_VALUES,SCATTER_REVERSE) || \ 1004 VecScatterEnd(ilink->sctx,ilink->x,yy,ADD_VALUES,SCATTER_REVERSE)) 1005 1006 #undef __FUNCT__ 1007 #define __FUNCT__ "PCApplyTranspose_FieldSplit" 1008 static PetscErrorCode PCApplyTranspose_FieldSplit(PC pc,Vec x,Vec y) 1009 { 1010 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1011 PetscErrorCode ierr; 1012 PC_FieldSplitLink ilink = jac->head; 1013 PetscInt bs; 1014 1015 PetscFunctionBegin; 1016 if (jac->type == PC_COMPOSITE_ADDITIVE) { 1017 if (jac->defaultsplit) { 1018 ierr = VecGetBlockSize(x,&bs);CHKERRQ(ierr); 1019 if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of x vector %D does not match fieldsplit blocksize %D",bs,jac->bs); 1020 ierr = VecGetBlockSize(y,&bs);CHKERRQ(ierr); 1021 if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of y vector %D does not match fieldsplit blocksize %D",bs,jac->bs); 1022 ierr = VecStrideGatherAll(x,jac->x,INSERT_VALUES);CHKERRQ(ierr); 1023 while (ilink) { 1024 ierr = KSPSolveTranspose(ilink->ksp,ilink->x,ilink->y);CHKERRQ(ierr); 1025 ilink = ilink->next; 1026 } 1027 ierr = VecStrideScatterAll(jac->y,y,INSERT_VALUES);CHKERRQ(ierr); 1028 } else { 1029 ierr = VecSet(y,0.0);CHKERRQ(ierr); 1030 while (ilink) { 1031 ierr = FieldSplitSplitSolveAddTranspose(ilink,x,y);CHKERRQ(ierr); 1032 ilink = ilink->next; 1033 } 1034 } 1035 } else { 1036 if (!jac->w1) { 1037 ierr = VecDuplicate(x,&jac->w1);CHKERRQ(ierr); 1038 ierr = VecDuplicate(x,&jac->w2);CHKERRQ(ierr); 1039 } 1040 ierr = VecSet(y,0.0);CHKERRQ(ierr); 1041 if (jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) { 1042 ierr = FieldSplitSplitSolveAddTranspose(ilink,x,y);CHKERRQ(ierr); 1043 while (ilink->next) { 1044 ilink = ilink->next; 1045 ierr = MatMultTranspose(pc->mat,y,jac->w1);CHKERRQ(ierr); 1046 ierr = VecWAXPY(jac->w2,-1.0,jac->w1,x);CHKERRQ(ierr); 1047 ierr = FieldSplitSplitSolveAddTranspose(ilink,jac->w2,y);CHKERRQ(ierr); 1048 } 1049 while (ilink->previous) { 1050 ilink = ilink->previous; 1051 ierr = MatMultTranspose(pc->mat,y,jac->w1);CHKERRQ(ierr); 1052 ierr = VecWAXPY(jac->w2,-1.0,jac->w1,x);CHKERRQ(ierr); 1053 ierr = FieldSplitSplitSolveAddTranspose(ilink,jac->w2,y);CHKERRQ(ierr); 1054 } 1055 } else { 1056 while (ilink->next) { /* get to last entry in linked list */ 1057 ilink = ilink->next; 1058 } 1059 ierr = FieldSplitSplitSolveAddTranspose(ilink,x,y);CHKERRQ(ierr); 1060 while (ilink->previous) { 1061 ilink = ilink->previous; 1062 ierr = MatMultTranspose(pc->mat,y,jac->w1);CHKERRQ(ierr); 1063 ierr = VecWAXPY(jac->w2,-1.0,jac->w1,x);CHKERRQ(ierr); 1064 ierr = FieldSplitSplitSolveAddTranspose(ilink,jac->w2,y);CHKERRQ(ierr); 1065 } 1066 } 1067 } 1068 PetscFunctionReturn(0); 1069 } 1070 1071 #undef __FUNCT__ 1072 #define __FUNCT__ "PCReset_FieldSplit" 1073 static PetscErrorCode PCReset_FieldSplit(PC pc) 1074 { 1075 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1076 PetscErrorCode ierr; 1077 PC_FieldSplitLink ilink = jac->head,next; 1078 1079 PetscFunctionBegin; 1080 while (ilink) { 1081 ierr = KSPReset(ilink->ksp);CHKERRQ(ierr); 1082 ierr = VecDestroy(&ilink->x);CHKERRQ(ierr); 1083 ierr = VecDestroy(&ilink->y);CHKERRQ(ierr); 1084 ierr = VecDestroy(&ilink->z);CHKERRQ(ierr); 1085 ierr = VecScatterDestroy(&ilink->sctx);CHKERRQ(ierr); 1086 ierr = ISDestroy(&ilink->is);CHKERRQ(ierr); 1087 ierr = ISDestroy(&ilink->is_col);CHKERRQ(ierr); 1088 next = ilink->next; 1089 ilink = next; 1090 } 1091 ierr = PetscFree2(jac->x,jac->y);CHKERRQ(ierr); 1092 if (jac->mat && jac->mat != jac->pmat) { 1093 ierr = MatDestroyMatrices(jac->nsplits,&jac->mat);CHKERRQ(ierr); 1094 } else if (jac->mat) { 1095 jac->mat = NULL; 1096 } 1097 if (jac->pmat) {ierr = MatDestroyMatrices(jac->nsplits,&jac->pmat);CHKERRQ(ierr);} 1098 if (jac->Afield) {ierr = MatDestroyMatrices(jac->nsplits,&jac->Afield);CHKERRQ(ierr);} 1099 ierr = VecDestroy(&jac->w1);CHKERRQ(ierr); 1100 ierr = VecDestroy(&jac->w2);CHKERRQ(ierr); 1101 ierr = MatDestroy(&jac->schur);CHKERRQ(ierr); 1102 ierr = MatDestroy(&jac->schurp);CHKERRQ(ierr); 1103 ierr = MatDestroy(&jac->schur_user);CHKERRQ(ierr); 1104 ierr = KSPDestroy(&jac->kspschur);CHKERRQ(ierr); 1105 ierr = KSPDestroy(&jac->kspupper);CHKERRQ(ierr); 1106 ierr = MatDestroy(&jac->B);CHKERRQ(ierr); 1107 ierr = MatDestroy(&jac->C);CHKERRQ(ierr); 1108 jac->reset = PETSC_TRUE; 1109 PetscFunctionReturn(0); 1110 } 1111 1112 #undef __FUNCT__ 1113 #define __FUNCT__ "PCDestroy_FieldSplit" 1114 static PetscErrorCode PCDestroy_FieldSplit(PC pc) 1115 { 1116 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1117 PetscErrorCode ierr; 1118 PC_FieldSplitLink ilink = jac->head,next; 1119 1120 PetscFunctionBegin; 1121 ierr = PCReset_FieldSplit(pc);CHKERRQ(ierr); 1122 while (ilink) { 1123 ierr = KSPDestroy(&ilink->ksp);CHKERRQ(ierr); 1124 next = ilink->next; 1125 ierr = PetscFree(ilink->splitname);CHKERRQ(ierr); 1126 ierr = PetscFree(ilink->fields);CHKERRQ(ierr); 1127 ierr = PetscFree(ilink->fields_col);CHKERRQ(ierr); 1128 ierr = PetscFree(ilink);CHKERRQ(ierr); 1129 ilink = next; 1130 } 1131 ierr = PetscFree2(jac->x,jac->y);CHKERRQ(ierr); 1132 ierr = PetscFree(pc->data);CHKERRQ(ierr); 1133 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",NULL);CHKERRQ(ierr); 1134 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetFields_C",NULL);CHKERRQ(ierr); 1135 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetIS_C",NULL);CHKERRQ(ierr); 1136 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetType_C",NULL);CHKERRQ(ierr); 1137 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetBlockSize_C",NULL);CHKERRQ(ierr); 1138 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurPre_C",NULL);CHKERRQ(ierr); 1139 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSchurPre_C",NULL);CHKERRQ(ierr); 1140 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurFactType_C",NULL);CHKERRQ(ierr); 1141 PetscFunctionReturn(0); 1142 } 1143 1144 #undef __FUNCT__ 1145 #define __FUNCT__ "PCSetFromOptions_FieldSplit" 1146 static PetscErrorCode PCSetFromOptions_FieldSplit(PetscOptions *PetscOptionsObject,PC pc) 1147 { 1148 PetscErrorCode ierr; 1149 PetscInt bs; 1150 PetscBool flg,stokes = PETSC_FALSE; 1151 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1152 PCCompositeType ctype; 1153 1154 PetscFunctionBegin; 1155 ierr = PetscOptionsHead(PetscOptionsObject,"FieldSplit options");CHKERRQ(ierr); 1156 ierr = PetscOptionsBool("-pc_fieldsplit_dm_splits","Whether to use DMCreateFieldDecomposition() for splits","PCFieldSplitSetDMSplits",jac->dm_splits,&jac->dm_splits,NULL);CHKERRQ(ierr); 1157 ierr = PetscOptionsInt("-pc_fieldsplit_block_size","Blocksize that defines number of fields","PCFieldSplitSetBlockSize",jac->bs,&bs,&flg);CHKERRQ(ierr); 1158 if (flg) { 1159 ierr = PCFieldSplitSetBlockSize(pc,bs);CHKERRQ(ierr); 1160 } 1161 1162 ierr = PetscOptionsBool("-pc_fieldsplit_diag_use_amat","Use Amat (not Pmat) to extract diagonal fieldsplit blocks", "PCFieldSplitSetDiagUseAmat",pc->useAmat,&jac->diag_use_amat,NULL);CHKERRQ(ierr); 1163 ierr = PetscOptionsBool("-pc_fieldsplit_off_diag_use_amat","Use Amat (not Pmat) to extract off-diagonal fieldsplit blocks", "PCFieldSplitSetOffDiagUseAmat",pc->useAmat,&jac->offdiag_use_amat,NULL);CHKERRQ(ierr); 1164 /* FIXME: No programmatic equivalent to the following. */ 1165 ierr = PetscOptionsGetBool(((PetscObject)pc)->prefix,"-pc_fieldsplit_detect_saddle_point",&stokes,NULL);CHKERRQ(ierr); 1166 if (stokes) { 1167 ierr = PCFieldSplitSetType(pc,PC_COMPOSITE_SCHUR);CHKERRQ(ierr); 1168 jac->schurpre = PC_FIELDSPLIT_SCHUR_PRE_SELF; 1169 } 1170 1171 ierr = PetscOptionsEnum("-pc_fieldsplit_type","Type of composition","PCFieldSplitSetType",PCCompositeTypes,(PetscEnum)jac->type,(PetscEnum*)&ctype,&flg);CHKERRQ(ierr); 1172 if (flg) { 1173 ierr = PCFieldSplitSetType(pc,ctype);CHKERRQ(ierr); 1174 } 1175 /* Only setup fields once */ 1176 if ((jac->bs > 0) && (jac->nsplits == 0)) { 1177 /* only allow user to set fields from command line if bs is already known. 1178 otherwise user can set them in PCFieldSplitSetDefaults() */ 1179 ierr = PCFieldSplitSetRuntimeSplits_Private(pc);CHKERRQ(ierr); 1180 if (jac->splitdefined) {ierr = PetscInfo(pc,"Splits defined using the options database\n");CHKERRQ(ierr);} 1181 } 1182 if (jac->type == PC_COMPOSITE_SCHUR) { 1183 ierr = PetscOptionsGetEnum(((PetscObject)pc)->prefix,"-pc_fieldsplit_schur_factorization_type",PCFieldSplitSchurFactTypes,(PetscEnum*)&jac->schurfactorization,&flg);CHKERRQ(ierr); 1184 if (flg) {ierr = PetscInfo(pc,"Deprecated use of -pc_fieldsplit_schur_factorization_type\n");CHKERRQ(ierr);} 1185 ierr = PetscOptionsEnum("-pc_fieldsplit_schur_fact_type","Which off-diagonal parts of the block factorization to use","PCFieldSplitSetSchurFactType",PCFieldSplitSchurFactTypes,(PetscEnum)jac->schurfactorization,(PetscEnum*)&jac->schurfactorization,NULL);CHKERRQ(ierr); 1186 ierr = PetscOptionsEnum("-pc_fieldsplit_schur_precondition","How to build preconditioner for Schur complement","PCFieldSplitSetSchurPre",PCFieldSplitSchurPreTypes,(PetscEnum)jac->schurpre,(PetscEnum*)&jac->schurpre,NULL);CHKERRQ(ierr); 1187 } 1188 ierr = PetscOptionsTail();CHKERRQ(ierr); 1189 PetscFunctionReturn(0); 1190 } 1191 1192 /*------------------------------------------------------------------------------------*/ 1193 1194 #undef __FUNCT__ 1195 #define __FUNCT__ "PCFieldSplitSetFields_FieldSplit" 1196 static PetscErrorCode PCFieldSplitSetFields_FieldSplit(PC pc,const char splitname[],PetscInt n,const PetscInt *fields,const PetscInt *fields_col) 1197 { 1198 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1199 PetscErrorCode ierr; 1200 PC_FieldSplitLink ilink,next = jac->head; 1201 char prefix[128]; 1202 PetscInt i; 1203 1204 PetscFunctionBegin; 1205 if (jac->splitdefined) { 1206 ierr = PetscInfo1(pc,"Ignoring new split \"%s\" because the splits have already been defined\n",splitname);CHKERRQ(ierr); 1207 PetscFunctionReturn(0); 1208 } 1209 for (i=0; i<n; i++) { 1210 if (fields[i] >= jac->bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Field %D requested but only %D exist",fields[i],jac->bs); 1211 if (fields[i] < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative field %D requested",fields[i]); 1212 } 1213 ierr = PetscNew(&ilink);CHKERRQ(ierr); 1214 if (splitname) { 1215 ierr = PetscStrallocpy(splitname,&ilink->splitname);CHKERRQ(ierr); 1216 } else { 1217 ierr = PetscMalloc1(3,&ilink->splitname);CHKERRQ(ierr); 1218 ierr = PetscSNPrintf(ilink->splitname,2,"%s",jac->nsplits);CHKERRQ(ierr); 1219 } 1220 ierr = PetscMalloc1(n,&ilink->fields);CHKERRQ(ierr); 1221 ierr = PetscMemcpy(ilink->fields,fields,n*sizeof(PetscInt));CHKERRQ(ierr); 1222 ierr = PetscMalloc1(n,&ilink->fields_col);CHKERRQ(ierr); 1223 ierr = PetscMemcpy(ilink->fields_col,fields_col,n*sizeof(PetscInt));CHKERRQ(ierr); 1224 1225 ilink->nfields = n; 1226 ilink->next = NULL; 1227 ierr = KSPCreate(PetscObjectComm((PetscObject)pc),&ilink->ksp);CHKERRQ(ierr); 1228 ierr = PetscObjectIncrementTabLevel((PetscObject)ilink->ksp,(PetscObject)pc,1);CHKERRQ(ierr); 1229 ierr = KSPSetType(ilink->ksp,KSPPREONLY);CHKERRQ(ierr); 1230 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilink->ksp);CHKERRQ(ierr); 1231 1232 ierr = PetscSNPrintf(prefix,sizeof(prefix),"%sfieldsplit_%s_",((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "",ilink->splitname);CHKERRQ(ierr); 1233 ierr = KSPSetOptionsPrefix(ilink->ksp,prefix);CHKERRQ(ierr); 1234 1235 if (!next) { 1236 jac->head = ilink; 1237 ilink->previous = NULL; 1238 } else { 1239 while (next->next) { 1240 next = next->next; 1241 } 1242 next->next = ilink; 1243 ilink->previous = next; 1244 } 1245 jac->nsplits++; 1246 PetscFunctionReturn(0); 1247 } 1248 1249 #undef __FUNCT__ 1250 #define __FUNCT__ "PCFieldSplitGetSubKSP_FieldSplit_Schur" 1251 static PetscErrorCode PCFieldSplitGetSubKSP_FieldSplit_Schur(PC pc,PetscInt *n,KSP **subksp) 1252 { 1253 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1254 PetscErrorCode ierr; 1255 1256 PetscFunctionBegin; 1257 ierr = PetscMalloc1(jac->nsplits,subksp);CHKERRQ(ierr); 1258 ierr = MatSchurComplementGetKSP(jac->schur,*subksp);CHKERRQ(ierr); 1259 1260 (*subksp)[1] = jac->kspschur; 1261 if (n) *n = jac->nsplits; 1262 PetscFunctionReturn(0); 1263 } 1264 1265 #undef __FUNCT__ 1266 #define __FUNCT__ "PCFieldSplitGetSubKSP_FieldSplit" 1267 static PetscErrorCode PCFieldSplitGetSubKSP_FieldSplit(PC pc,PetscInt *n,KSP **subksp) 1268 { 1269 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1270 PetscErrorCode ierr; 1271 PetscInt cnt = 0; 1272 PC_FieldSplitLink ilink = jac->head; 1273 1274 PetscFunctionBegin; 1275 ierr = PetscMalloc1(jac->nsplits,subksp);CHKERRQ(ierr); 1276 while (ilink) { 1277 (*subksp)[cnt++] = ilink->ksp; 1278 ilink = ilink->next; 1279 } 1280 if (cnt != jac->nsplits) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Corrupt PCFIELDSPLIT object: number of splits in linked list %D does not match number in object %D",cnt,jac->nsplits); 1281 if (n) *n = jac->nsplits; 1282 PetscFunctionReturn(0); 1283 } 1284 1285 #undef __FUNCT__ 1286 #define __FUNCT__ "PCFieldSplitSetIS_FieldSplit" 1287 static PetscErrorCode PCFieldSplitSetIS_FieldSplit(PC pc,const char splitname[],IS is) 1288 { 1289 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1290 PetscErrorCode ierr; 1291 PC_FieldSplitLink ilink, next = jac->head; 1292 char prefix[128]; 1293 1294 PetscFunctionBegin; 1295 if (jac->splitdefined) { 1296 ierr = PetscInfo1(pc,"Ignoring new split \"%s\" because the splits have already been defined\n",splitname);CHKERRQ(ierr); 1297 PetscFunctionReturn(0); 1298 } 1299 ierr = PetscNew(&ilink);CHKERRQ(ierr); 1300 if (splitname) { 1301 ierr = PetscStrallocpy(splitname,&ilink->splitname);CHKERRQ(ierr); 1302 } else { 1303 ierr = PetscMalloc1(8,&ilink->splitname);CHKERRQ(ierr); 1304 ierr = PetscSNPrintf(ilink->splitname,7,"%D",jac->nsplits);CHKERRQ(ierr); 1305 } 1306 ierr = PetscObjectReference((PetscObject)is);CHKERRQ(ierr); 1307 ierr = ISDestroy(&ilink->is);CHKERRQ(ierr); 1308 ilink->is = is; 1309 ierr = PetscObjectReference((PetscObject)is);CHKERRQ(ierr); 1310 ierr = ISDestroy(&ilink->is_col);CHKERRQ(ierr); 1311 ilink->is_col = is; 1312 ilink->next = NULL; 1313 ierr = KSPCreate(PetscObjectComm((PetscObject)pc),&ilink->ksp);CHKERRQ(ierr); 1314 ierr = PetscObjectIncrementTabLevel((PetscObject)ilink->ksp,(PetscObject)pc,1);CHKERRQ(ierr); 1315 ierr = KSPSetType(ilink->ksp,KSPPREONLY);CHKERRQ(ierr); 1316 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilink->ksp);CHKERRQ(ierr); 1317 1318 ierr = PetscSNPrintf(prefix,sizeof(prefix),"%sfieldsplit_%s_",((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "",ilink->splitname);CHKERRQ(ierr); 1319 ierr = KSPSetOptionsPrefix(ilink->ksp,prefix);CHKERRQ(ierr); 1320 1321 if (!next) { 1322 jac->head = ilink; 1323 ilink->previous = NULL; 1324 } else { 1325 while (next->next) { 1326 next = next->next; 1327 } 1328 next->next = ilink; 1329 ilink->previous = next; 1330 } 1331 jac->nsplits++; 1332 PetscFunctionReturn(0); 1333 } 1334 1335 #undef __FUNCT__ 1336 #define __FUNCT__ "PCFieldSplitSetFields" 1337 /*@ 1338 PCFieldSplitSetFields - Sets the fields for one particular split in the field split preconditioner 1339 1340 Logically Collective on PC 1341 1342 Input Parameters: 1343 + pc - the preconditioner context 1344 . splitname - name of this split, if NULL the number of the split is used 1345 . n - the number of fields in this split 1346 - fields - the fields in this split 1347 1348 Level: intermediate 1349 1350 Notes: Use PCFieldSplitSetIS() to set a completely general set of indices as a field. 1351 1352 The PCFieldSplitSetFields() is for defining fields as strided blocks. For example, if the block 1353 size is three then one can define a field as 0, or 1 or 2 or 0,1 or 0,2 or 1,2 which mean 1354 0xx3xx6xx9xx12 ... x1xx4xx7xx ... xx2xx5xx8xx.. 01x34x67x... 0x1x3x5x7.. x12x45x78x.... 1355 where the numbered entries indicate what is in the field. 1356 1357 This function is called once per split (it creates a new split each time). Solve options 1358 for this split will be available under the prefix -fieldsplit_SPLITNAME_. 1359 1360 Developer Note: This routine does not actually create the IS representing the split, that is delayed 1361 until PCSetUp_FieldSplit(), because information about the vector/matrix layouts may not be 1362 available when this routine is called. 1363 1364 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetBlockSize(), PCFieldSplitSetIS() 1365 1366 @*/ 1367 PetscErrorCode PCFieldSplitSetFields(PC pc,const char splitname[],PetscInt n,const PetscInt *fields,const PetscInt *fields_col) 1368 { 1369 PetscErrorCode ierr; 1370 1371 PetscFunctionBegin; 1372 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1373 PetscValidCharPointer(splitname,2); 1374 if (n < 1) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Provided number of fields %D in split \"%s\" not positive",n,splitname); 1375 PetscValidIntPointer(fields,3); 1376 ierr = PetscTryMethod(pc,"PCFieldSplitSetFields_C",(PC,const char[],PetscInt,const PetscInt*,const PetscInt*),(pc,splitname,n,fields,fields_col));CHKERRQ(ierr); 1377 PetscFunctionReturn(0); 1378 } 1379 1380 #undef __FUNCT__ 1381 #define __FUNCT__ "PCFieldSplitSetDiagUseAmat" 1382 /*@ 1383 PCFieldSplitSetDiagUseAmat - set flag indicating whether to extract diagonal blocks from Amat (rather than Pmat) 1384 1385 Logically Collective on PC 1386 1387 Input Parameters: 1388 + pc - the preconditioner object 1389 - flg - boolean flag indicating whether or not to use Amat to extract the diagonal blocks from 1390 1391 Options Database: 1392 . -pc_fieldsplit_diag_use_amat 1393 1394 Level: intermediate 1395 1396 .seealso: PCFieldSplitGetDiagUseAmat(), PCFieldSplitSetOffDiagUseAmat(), PCFIELDSPLIT 1397 1398 @*/ 1399 PetscErrorCode PCFieldSplitSetDiagUseAmat(PC pc,PetscBool flg) 1400 { 1401 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1402 PetscBool isfs; 1403 PetscErrorCode ierr; 1404 1405 PetscFunctionBegin; 1406 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1407 ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 1408 if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT); 1409 jac->diag_use_amat = flg; 1410 PetscFunctionReturn(0); 1411 } 1412 1413 #undef __FUNCT__ 1414 #define __FUNCT__ "PCFieldSplitGetDiagUseAmat" 1415 /*@ 1416 PCFieldSplitGetDiagUseAmat - get the flag indicating whether to extract diagonal blocks from Amat (rather than Pmat) 1417 1418 Logically Collective on PC 1419 1420 Input Parameters: 1421 . pc - the preconditioner object 1422 1423 Output Parameters: 1424 . flg - boolean flag indicating whether or not to use Amat to extract the diagonal blocks from 1425 1426 1427 Level: intermediate 1428 1429 .seealso: PCFieldSplitSetDiagUseAmat(), PCFieldSplitGetOffDiagUseAmat(), PCFIELDSPLIT 1430 1431 @*/ 1432 PetscErrorCode PCFieldSplitGetDiagUseAmat(PC pc,PetscBool *flg) 1433 { 1434 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1435 PetscBool isfs; 1436 PetscErrorCode ierr; 1437 1438 PetscFunctionBegin; 1439 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1440 PetscValidPointer(flg,2); 1441 ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 1442 if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT); 1443 *flg = jac->diag_use_amat; 1444 PetscFunctionReturn(0); 1445 } 1446 1447 #undef __FUNCT__ 1448 #define __FUNCT__ "PCFieldSplitSetOffDiagUseAmat" 1449 /*@ 1450 PCFieldSplitSetOffDiagUseAmat - set flag indicating whether to extract off-diagonal blocks from Amat (rather than Pmat) 1451 1452 Logically Collective on PC 1453 1454 Input Parameters: 1455 + pc - the preconditioner object 1456 - flg - boolean flag indicating whether or not to use Amat to extract the off-diagonal blocks from 1457 1458 Options Database: 1459 . -pc_fieldsplit_off_diag_use_amat 1460 1461 Level: intermediate 1462 1463 .seealso: PCFieldSplitGetOffDiagUseAmat(), PCFieldSplitSetDiagUseAmat(), PCFIELDSPLIT 1464 1465 @*/ 1466 PetscErrorCode PCFieldSplitSetOffDiagUseAmat(PC pc,PetscBool flg) 1467 { 1468 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1469 PetscBool isfs; 1470 PetscErrorCode ierr; 1471 1472 PetscFunctionBegin; 1473 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1474 ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 1475 if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT); 1476 jac->offdiag_use_amat = flg; 1477 PetscFunctionReturn(0); 1478 } 1479 1480 #undef __FUNCT__ 1481 #define __FUNCT__ "PCFieldSplitGetOffDiagUseAmat" 1482 /*@ 1483 PCFieldSplitGetOffDiagUseAmat - get the flag indicating whether to extract off-diagonal blocks from Amat (rather than Pmat) 1484 1485 Logically Collective on PC 1486 1487 Input Parameters: 1488 . pc - the preconditioner object 1489 1490 Output Parameters: 1491 . flg - boolean flag indicating whether or not to use Amat to extract the off-diagonal blocks from 1492 1493 1494 Level: intermediate 1495 1496 .seealso: PCFieldSplitSetOffDiagUseAmat(), PCFieldSplitGetDiagUseAmat(), PCFIELDSPLIT 1497 1498 @*/ 1499 PetscErrorCode PCFieldSplitGetOffDiagUseAmat(PC pc,PetscBool *flg) 1500 { 1501 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1502 PetscBool isfs; 1503 PetscErrorCode ierr; 1504 1505 PetscFunctionBegin; 1506 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1507 PetscValidPointer(flg,2); 1508 ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 1509 if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT); 1510 *flg = jac->offdiag_use_amat; 1511 PetscFunctionReturn(0); 1512 } 1513 1514 1515 1516 #undef __FUNCT__ 1517 #define __FUNCT__ "PCFieldSplitSetIS" 1518 /*@ 1519 PCFieldSplitSetIS - Sets the exact elements for field 1520 1521 Logically Collective on PC 1522 1523 Input Parameters: 1524 + pc - the preconditioner context 1525 . splitname - name of this split, if NULL the number of the split is used 1526 - is - the index set that defines the vector elements in this field 1527 1528 1529 Notes: 1530 Use PCFieldSplitSetFields(), for fields defined by strided types. 1531 1532 This function is called once per split (it creates a new split each time). Solve options 1533 for this split will be available under the prefix -fieldsplit_SPLITNAME_. 1534 1535 Level: intermediate 1536 1537 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetBlockSize() 1538 1539 @*/ 1540 PetscErrorCode PCFieldSplitSetIS(PC pc,const char splitname[],IS is) 1541 { 1542 PetscErrorCode ierr; 1543 1544 PetscFunctionBegin; 1545 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1546 if (splitname) PetscValidCharPointer(splitname,2); 1547 PetscValidHeaderSpecific(is,IS_CLASSID,3); 1548 ierr = PetscTryMethod(pc,"PCFieldSplitSetIS_C",(PC,const char[],IS),(pc,splitname,is));CHKERRQ(ierr); 1549 PetscFunctionReturn(0); 1550 } 1551 1552 #undef __FUNCT__ 1553 #define __FUNCT__ "PCFieldSplitGetIS" 1554 /*@ 1555 PCFieldSplitGetIS - Retrieves the elements for a field as an IS 1556 1557 Logically Collective on PC 1558 1559 Input Parameters: 1560 + pc - the preconditioner context 1561 - splitname - name of this split 1562 1563 Output Parameter: 1564 - is - the index set that defines the vector elements in this field, or NULL if the field is not found 1565 1566 Level: intermediate 1567 1568 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetIS() 1569 1570 @*/ 1571 PetscErrorCode PCFieldSplitGetIS(PC pc,const char splitname[],IS *is) 1572 { 1573 PetscErrorCode ierr; 1574 1575 PetscFunctionBegin; 1576 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1577 PetscValidCharPointer(splitname,2); 1578 PetscValidPointer(is,3); 1579 { 1580 PC_FieldSplit *jac = (PC_FieldSplit*) pc->data; 1581 PC_FieldSplitLink ilink = jac->head; 1582 PetscBool found; 1583 1584 *is = NULL; 1585 while (ilink) { 1586 ierr = PetscStrcmp(ilink->splitname, splitname, &found);CHKERRQ(ierr); 1587 if (found) { 1588 *is = ilink->is; 1589 break; 1590 } 1591 ilink = ilink->next; 1592 } 1593 } 1594 PetscFunctionReturn(0); 1595 } 1596 1597 #undef __FUNCT__ 1598 #define __FUNCT__ "PCFieldSplitSetBlockSize" 1599 /*@ 1600 PCFieldSplitSetBlockSize - Sets the block size for defining where fields start in the 1601 fieldsplit preconditioner. If not set the matrix block size is used. 1602 1603 Logically Collective on PC 1604 1605 Input Parameters: 1606 + pc - the preconditioner context 1607 - bs - the block size 1608 1609 Level: intermediate 1610 1611 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields() 1612 1613 @*/ 1614 PetscErrorCode PCFieldSplitSetBlockSize(PC pc,PetscInt bs) 1615 { 1616 PetscErrorCode ierr; 1617 1618 PetscFunctionBegin; 1619 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1620 PetscValidLogicalCollectiveInt(pc,bs,2); 1621 ierr = PetscTryMethod(pc,"PCFieldSplitSetBlockSize_C",(PC,PetscInt),(pc,bs));CHKERRQ(ierr); 1622 PetscFunctionReturn(0); 1623 } 1624 1625 #undef __FUNCT__ 1626 #define __FUNCT__ "PCFieldSplitGetSubKSP" 1627 /*@C 1628 PCFieldSplitGetSubKSP - Gets the KSP contexts for all splits 1629 1630 Collective on KSP 1631 1632 Input Parameter: 1633 . pc - the preconditioner context 1634 1635 Output Parameters: 1636 + n - the number of splits 1637 - pc - the array of KSP contexts 1638 1639 Note: 1640 After PCFieldSplitGetSubKSP() the array of KSPs IS to be freed by the user 1641 (not the KSP just the array that contains them). 1642 1643 You must call KSPSetUp() before calling PCFieldSplitGetSubKSP(). 1644 1645 Fortran Usage: You must pass in a KSP array that is large enough to contain all the local KSPs. 1646 You can call PCFieldSplitGetSubKSP(pc,n,NULL_OBJECT,ierr) to determine how large the 1647 KSP array must be. 1648 1649 1650 Level: advanced 1651 1652 .seealso: PCFIELDSPLIT 1653 @*/ 1654 PetscErrorCode PCFieldSplitGetSubKSP(PC pc,PetscInt *n,KSP *subksp[]) 1655 { 1656 PetscErrorCode ierr; 1657 1658 PetscFunctionBegin; 1659 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1660 if (n) PetscValidIntPointer(n,2); 1661 ierr = PetscUseMethod(pc,"PCFieldSplitGetSubKSP_C",(PC,PetscInt*,KSP **),(pc,n,subksp));CHKERRQ(ierr); 1662 PetscFunctionReturn(0); 1663 } 1664 1665 #undef __FUNCT__ 1666 #define __FUNCT__ "PCFieldSplitSetSchurPre" 1667 /*@ 1668 PCFieldSplitSetSchurPre - Indicates if the Schur complement is preconditioned by a preconditioner constructed by the 1669 A11 matrix. Otherwise no preconditioner is used. 1670 1671 Collective on PC 1672 1673 Input Parameters: 1674 + pc - the preconditioner context 1675 . ptype - which matrix to use for preconditioning the Schur complement: PC_FIELDSPLIT_SCHUR_PRE_A11 (default), PC_FIELDSPLIT_SCHUR_PRE_SELF, PC_FIELDSPLIT_PRE_USER 1676 - userpre - matrix to use for preconditioning, or NULL 1677 1678 Options Database: 1679 . -pc_fieldsplit_schur_precondition <self,selfp,user,a11,full> default is a11 1680 1681 Notes: 1682 $ If ptype is 1683 $ user then the preconditioner for the Schur complement is generated by the provided matrix (pre argument 1684 $ to this function). 1685 $ a11 then the preconditioner for the Schur complement is generated by the block diagonal part of the preconditioner 1686 $ matrix associated with the Schur complement (i.e. A11), not he Schur complement matrix 1687 $ full then the preconditioner uses the exact Schur complement (this is expensive) 1688 $ self the preconditioner for the Schur complement is generated from the Schur complement matrix itself: 1689 $ The only preconditioner that currently works directly with the Schur complement matrix object is the PCLSC 1690 $ preconditioner 1691 $ selfp then the preconditioning matrix is an explicitly-assembled approximation Sp = A11 - A10 inv(diag(A00)) A01 1692 $ This is only a good preconditioner when diag(A00) is a good preconditioner for A00. 1693 1694 When solving a saddle point problem, where the A11 block is identically zero, using a11 as the ptype only makes sense 1695 with the additional option -fieldsplit_1_pc_type none. Usually for saddle point problems one would use a ptype of self and 1696 -fieldsplit_1_pc_type lsc which uses the least squares commutator to compute a preconditioner for the Schur complement. 1697 1698 Level: intermediate 1699 1700 .seealso: PCFieldSplitGetSchurPre(), PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType, PCLSC 1701 1702 @*/ 1703 PetscErrorCode PCFieldSplitSetSchurPre(PC pc,PCFieldSplitSchurPreType ptype,Mat pre) 1704 { 1705 PetscErrorCode ierr; 1706 1707 PetscFunctionBegin; 1708 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1709 ierr = PetscTryMethod(pc,"PCFieldSplitSetSchurPre_C",(PC,PCFieldSplitSchurPreType,Mat),(pc,ptype,pre));CHKERRQ(ierr); 1710 PetscFunctionReturn(0); 1711 } 1712 PetscErrorCode PCFieldSplitSchurPrecondition(PC pc,PCFieldSplitSchurPreType ptype,Mat pre) {return PCFieldSplitSetSchurPre(pc,ptype,pre);} /* Deprecated name */ 1713 1714 #undef __FUNCT__ 1715 #define __FUNCT__ "PCFieldSplitGetSchurPre" 1716 /*@ 1717 PCFieldSplitGetSchurPre - For Schur complement fieldsplit, determine how the Schur complement will be 1718 preconditioned. See PCFieldSplitSetSchurPre() for details. 1719 1720 Logically Collective on PC 1721 1722 Input Parameters: 1723 . pc - the preconditioner context 1724 1725 Output Parameters: 1726 + ptype - which matrix to use for preconditioning the Schur complement: PC_FIELDSPLIT_SCHUR_PRE_A11, PC_FIELDSPLIT_SCHUR_PRE_SELF, PC_FIELDSPLIT_PRE_USER 1727 - userpre - matrix to use for preconditioning (with PC_FIELDSPLIT_PRE_USER), or NULL 1728 1729 Level: intermediate 1730 1731 .seealso: PCFieldSplitSetSchurPre(), PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType, PCLSC 1732 1733 @*/ 1734 PetscErrorCode PCFieldSplitGetSchurPre(PC pc,PCFieldSplitSchurPreType *ptype,Mat *pre) 1735 { 1736 PetscErrorCode ierr; 1737 1738 PetscFunctionBegin; 1739 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1740 ierr = PetscUseMethod(pc,"PCFieldSplitGetSchurPre_C",(PC,PCFieldSplitSchurPreType*,Mat*),(pc,ptype,pre));CHKERRQ(ierr); 1741 PetscFunctionReturn(0); 1742 } 1743 1744 #undef __FUNCT__ 1745 #define __FUNCT__ "PCFieldSplitSchurGetS" 1746 /*@ 1747 PCFieldSplitSchurGetS - extract the MatSchurComplement object used by this PC in case it needs to be configured separately 1748 1749 Not collective 1750 1751 Input Parameter: 1752 . pc - the preconditioner context 1753 1754 Output Parameter: 1755 . S - the Schur complement matrix 1756 1757 Notes: 1758 This matrix should not be destroyed using MatDestroy(); rather, use PCFieldSplitSchurRestoreS(). 1759 1760 Level: advanced 1761 1762 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSchurPreType, PCFieldSplitSetSchurPre(), MatSchurComplement, PCFieldSplitSchurRestoreS() 1763 1764 @*/ 1765 PetscErrorCode PCFieldSplitSchurGetS(PC pc,Mat *S) 1766 { 1767 PetscErrorCode ierr; 1768 const char* t; 1769 PetscBool isfs; 1770 PC_FieldSplit *jac; 1771 1772 PetscFunctionBegin; 1773 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1774 ierr = PetscObjectGetType((PetscObject)pc,&t);CHKERRQ(ierr); 1775 ierr = PetscStrcmp(t,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 1776 if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PC of type PCFIELDSPLIT, got %s instead",t); 1777 jac = (PC_FieldSplit*)pc->data; 1778 if (jac->type != PC_COMPOSITE_SCHUR) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PCFIELDSPLIT of type SCHUR, got %D instead",jac->type); 1779 if (S) *S = jac->schur; 1780 PetscFunctionReturn(0); 1781 } 1782 1783 #undef __FUNCT__ 1784 #define __FUNCT__ "PCFieldSplitSchurRestoreS" 1785 /*@ 1786 PCFieldSplitSchurRestoreS - restores the MatSchurComplement object used by this PC 1787 1788 Not collective 1789 1790 Input Parameters: 1791 + pc - the preconditioner context 1792 . S - the Schur complement matrix 1793 1794 Level: advanced 1795 1796 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSchurPreType, PCFieldSplitSetSchurPre(), MatSchurComplement, PCFieldSplitSchurGetS() 1797 1798 @*/ 1799 PetscErrorCode PCFieldSplitSchurRestoreS(PC pc,Mat *S) 1800 { 1801 PetscErrorCode ierr; 1802 const char* t; 1803 PetscBool isfs; 1804 PC_FieldSplit *jac; 1805 1806 PetscFunctionBegin; 1807 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1808 ierr = PetscObjectGetType((PetscObject)pc,&t);CHKERRQ(ierr); 1809 ierr = PetscStrcmp(t,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 1810 if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PC of type PCFIELDSPLIT, got %s instead",t); 1811 jac = (PC_FieldSplit*)pc->data; 1812 if (jac->type != PC_COMPOSITE_SCHUR) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PCFIELDSPLIT of type SCHUR, got %D instead",jac->type); 1813 if (!S || *S != jac->schur) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"MatSchurComplement restored is not the same as gotten"); 1814 PetscFunctionReturn(0); 1815 } 1816 1817 1818 #undef __FUNCT__ 1819 #define __FUNCT__ "PCFieldSplitSetSchurPre_FieldSplit" 1820 static PetscErrorCode PCFieldSplitSetSchurPre_FieldSplit(PC pc,PCFieldSplitSchurPreType ptype,Mat pre) 1821 { 1822 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1823 PetscErrorCode ierr; 1824 1825 PetscFunctionBegin; 1826 jac->schurpre = ptype; 1827 if (ptype == PC_FIELDSPLIT_SCHUR_PRE_USER && pre) { 1828 ierr = MatDestroy(&jac->schur_user);CHKERRQ(ierr); 1829 jac->schur_user = pre; 1830 ierr = PetscObjectReference((PetscObject)jac->schur_user);CHKERRQ(ierr); 1831 } 1832 PetscFunctionReturn(0); 1833 } 1834 1835 #undef __FUNCT__ 1836 #define __FUNCT__ "PCFieldSplitGetSchurPre_FieldSplit" 1837 static PetscErrorCode PCFieldSplitGetSchurPre_FieldSplit(PC pc,PCFieldSplitSchurPreType *ptype,Mat *pre) 1838 { 1839 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1840 1841 PetscFunctionBegin; 1842 *ptype = jac->schurpre; 1843 *pre = jac->schur_user; 1844 PetscFunctionReturn(0); 1845 } 1846 1847 #undef __FUNCT__ 1848 #define __FUNCT__ "PCFieldSplitSetSchurFactType" 1849 /*@ 1850 PCFieldSplitSetSchurFactType - sets which blocks of the approximate block factorization to retain 1851 1852 Collective on PC 1853 1854 Input Parameters: 1855 + pc - the preconditioner context 1856 - ftype - which blocks of factorization to retain, PC_FIELDSPLIT_SCHUR_FACT_FULL is default 1857 1858 Options Database: 1859 . -pc_fieldsplit_schur_fact_type <diag,lower,upper,full> default is full 1860 1861 1862 Level: intermediate 1863 1864 Notes: 1865 The FULL factorization is 1866 1867 $ (A B) = (1 0) (A 0) (1 Ainv*B) 1868 $ (C D) (C*Ainv 1) (0 S) (0 1 ) 1869 1870 where S = D - C*Ainv*B. In practice, the full factorization is applied via block triangular solves with the grouping L*(D*U). UPPER uses D*U, LOWER uses L*D, 1871 and DIAG is the diagonal part with the sign of S flipped (because this makes the preconditioner positive definite for many formulations, thus allowing the use of KSPMINRES). 1872 1873 If applied exactly, FULL factorization is a direct solver. The preconditioned operator with LOWER or UPPER has all eigenvalues equal to 1 and minimal polynomial 1874 of degree 2, so KSPGMRES converges in 2 iterations. If the iteration count is very low, consider using KSPFGMRES or KSPGCR which can use one less preconditioner 1875 application in this case. Note that the preconditioned operator may be highly non-normal, so such fast convergence may not be observed in practice. With DIAG, 1876 the preconditioned operator has three distinct nonzero eigenvalues and minimal polynomial of degree at most 4, so KSPGMRES converges in at most 4 iterations. 1877 1878 For symmetric problems in which A is positive definite and S is negative definite, DIAG can be used with KSPMINRES. Note that a flexible method like KSPFGMRES 1879 or KSPGCR must be used if the fieldsplit preconditioner is nonlinear (e.g. a few iterations of a Krylov method is used inside a split). 1880 1881 References: 1882 Murphy, Golub, and Wathen, A note on preconditioning indefinite linear systems, SIAM J. Sci. Comput., 21 (2000) pp. 1969-1972. 1883 1884 Ipsen, A note on preconditioning nonsymmetric matrices, SIAM J. Sci. Comput., 23 (2001), pp. 1050-1051. 1885 1886 .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType 1887 @*/ 1888 PetscErrorCode PCFieldSplitSetSchurFactType(PC pc,PCFieldSplitSchurFactType ftype) 1889 { 1890 PetscErrorCode ierr; 1891 1892 PetscFunctionBegin; 1893 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1894 ierr = PetscTryMethod(pc,"PCFieldSplitSetSchurFactType_C",(PC,PCFieldSplitSchurFactType),(pc,ftype));CHKERRQ(ierr); 1895 PetscFunctionReturn(0); 1896 } 1897 1898 #undef __FUNCT__ 1899 #define __FUNCT__ "PCFieldSplitSetSchurFactType_FieldSplit" 1900 static PetscErrorCode PCFieldSplitSetSchurFactType_FieldSplit(PC pc,PCFieldSplitSchurFactType ftype) 1901 { 1902 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1903 1904 PetscFunctionBegin; 1905 jac->schurfactorization = ftype; 1906 PetscFunctionReturn(0); 1907 } 1908 1909 #undef __FUNCT__ 1910 #define __FUNCT__ "PCFieldSplitGetSchurBlocks" 1911 /*@C 1912 PCFieldSplitGetSchurBlocks - Gets all matrix blocks for the Schur complement 1913 1914 Collective on KSP 1915 1916 Input Parameter: 1917 . pc - the preconditioner context 1918 1919 Output Parameters: 1920 + A00 - the (0,0) block 1921 . A01 - the (0,1) block 1922 . A10 - the (1,0) block 1923 - A11 - the (1,1) block 1924 1925 Level: advanced 1926 1927 .seealso: PCFIELDSPLIT 1928 @*/ 1929 PetscErrorCode PCFieldSplitGetSchurBlocks(PC pc,Mat *A00,Mat *A01,Mat *A10, Mat *A11) 1930 { 1931 PC_FieldSplit *jac = (PC_FieldSplit*) pc->data; 1932 1933 PetscFunctionBegin; 1934 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1935 if (jac->type != PC_COMPOSITE_SCHUR) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONG, "FieldSplit is not using a Schur complement approach."); 1936 if (A00) *A00 = jac->pmat[0]; 1937 if (A01) *A01 = jac->B; 1938 if (A10) *A10 = jac->C; 1939 if (A11) *A11 = jac->pmat[1]; 1940 PetscFunctionReturn(0); 1941 } 1942 1943 #undef __FUNCT__ 1944 #define __FUNCT__ "PCFieldSplitSetType_FieldSplit" 1945 static PetscErrorCode PCFieldSplitSetType_FieldSplit(PC pc,PCCompositeType type) 1946 { 1947 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1948 PetscErrorCode ierr; 1949 1950 PetscFunctionBegin; 1951 jac->type = type; 1952 if (type == PC_COMPOSITE_SCHUR) { 1953 pc->ops->apply = PCApply_FieldSplit_Schur; 1954 pc->ops->view = PCView_FieldSplit_Schur; 1955 1956 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",PCFieldSplitGetSubKSP_FieldSplit_Schur);CHKERRQ(ierr); 1957 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurPre_C",PCFieldSplitSetSchurPre_FieldSplit);CHKERRQ(ierr); 1958 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSchurPre_C",PCFieldSplitGetSchurPre_FieldSplit);CHKERRQ(ierr); 1959 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurFactType_C",PCFieldSplitSetSchurFactType_FieldSplit);CHKERRQ(ierr); 1960 1961 } else { 1962 pc->ops->apply = PCApply_FieldSplit; 1963 pc->ops->view = PCView_FieldSplit; 1964 1965 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",PCFieldSplitGetSubKSP_FieldSplit);CHKERRQ(ierr); 1966 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurPre_C",0);CHKERRQ(ierr); 1967 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSchurPre_C",0);CHKERRQ(ierr); 1968 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurFactType_C",0);CHKERRQ(ierr); 1969 } 1970 PetscFunctionReturn(0); 1971 } 1972 1973 #undef __FUNCT__ 1974 #define __FUNCT__ "PCFieldSplitSetBlockSize_FieldSplit" 1975 static PetscErrorCode PCFieldSplitSetBlockSize_FieldSplit(PC pc,PetscInt bs) 1976 { 1977 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 1978 1979 PetscFunctionBegin; 1980 if (bs < 1) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Blocksize must be positive, you gave %D",bs); 1981 if (jac->bs > 0 && jac->bs != bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Cannot change fieldsplit blocksize from %D to %D after it has been set",jac->bs,bs); 1982 jac->bs = bs; 1983 PetscFunctionReturn(0); 1984 } 1985 1986 #undef __FUNCT__ 1987 #define __FUNCT__ "PCFieldSplitSetType" 1988 /*@ 1989 PCFieldSplitSetType - Sets the type of fieldsplit preconditioner. 1990 1991 Collective on PC 1992 1993 Input Parameter: 1994 . pc - the preconditioner context 1995 . type - PC_COMPOSITE_ADDITIVE, PC_COMPOSITE_MULTIPLICATIVE (default), PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE, PC_COMPOSITE_SPECIAL, PC_COMPOSITE_SCHUR 1996 1997 Options Database Key: 1998 . -pc_fieldsplit_type <type: one of multiplicative, additive, symmetric_multiplicative, special, schur> - Sets fieldsplit preconditioner type 1999 2000 Level: Intermediate 2001 2002 .keywords: PC, set, type, composite preconditioner, additive, multiplicative 2003 2004 .seealso: PCCompositeSetType() 2005 2006 @*/ 2007 PetscErrorCode PCFieldSplitSetType(PC pc,PCCompositeType type) 2008 { 2009 PetscErrorCode ierr; 2010 2011 PetscFunctionBegin; 2012 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 2013 ierr = PetscTryMethod(pc,"PCFieldSplitSetType_C",(PC,PCCompositeType),(pc,type));CHKERRQ(ierr); 2014 PetscFunctionReturn(0); 2015 } 2016 2017 #undef __FUNCT__ 2018 #define __FUNCT__ "PCFieldSplitGetType" 2019 /*@ 2020 PCFieldSplitGetType - Gets the type of fieldsplit preconditioner. 2021 2022 Not collective 2023 2024 Input Parameter: 2025 . pc - the preconditioner context 2026 2027 Output Parameter: 2028 . type - PC_COMPOSITE_ADDITIVE, PC_COMPOSITE_MULTIPLICATIVE (default), PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE, PC_COMPOSITE_SPECIAL, PC_COMPOSITE_SCHUR 2029 2030 Level: Intermediate 2031 2032 .keywords: PC, set, type, composite preconditioner, additive, multiplicative 2033 .seealso: PCCompositeSetType() 2034 @*/ 2035 PetscErrorCode PCFieldSplitGetType(PC pc, PCCompositeType *type) 2036 { 2037 PC_FieldSplit *jac = (PC_FieldSplit*) pc->data; 2038 2039 PetscFunctionBegin; 2040 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 2041 PetscValidIntPointer(type,2); 2042 *type = jac->type; 2043 PetscFunctionReturn(0); 2044 } 2045 2046 #undef __FUNCT__ 2047 #define __FUNCT__ "PCFieldSplitSetDMSplits" 2048 /*@ 2049 PCFieldSplitSetDMSplits - Flags whether DMCreateFieldDecomposition() should be used to define the splits, whenever possible. 2050 2051 Logically Collective 2052 2053 Input Parameters: 2054 + pc - the preconditioner context 2055 - flg - boolean indicating whether to use field splits defined by the DM 2056 2057 Options Database Key: 2058 . -pc_fieldsplit_dm_splits 2059 2060 Level: Intermediate 2061 2062 .keywords: PC, DM, composite preconditioner, additive, multiplicative 2063 2064 .seealso: PCFieldSplitGetDMSplits() 2065 2066 @*/ 2067 PetscErrorCode PCFieldSplitSetDMSplits(PC pc,PetscBool flg) 2068 { 2069 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 2070 PetscBool isfs; 2071 PetscErrorCode ierr; 2072 2073 PetscFunctionBegin; 2074 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 2075 PetscValidLogicalCollectiveBool(pc,flg,2); 2076 ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 2077 if (isfs) { 2078 jac->dm_splits = flg; 2079 } 2080 PetscFunctionReturn(0); 2081 } 2082 2083 2084 #undef __FUNCT__ 2085 #define __FUNCT__ "PCFieldSplitGetDMSplits" 2086 /*@ 2087 PCFieldSplitGetDMSplits - Returns flag indicating whether DMCreateFieldDecomposition() should be used to define the splits, whenever possible. 2088 2089 Logically Collective 2090 2091 Input Parameter: 2092 . pc - the preconditioner context 2093 2094 Output Parameter: 2095 . flg - boolean indicating whether to use field splits defined by the DM 2096 2097 Level: Intermediate 2098 2099 .keywords: PC, DM, composite preconditioner, additive, multiplicative 2100 2101 .seealso: PCFieldSplitSetDMSplits() 2102 2103 @*/ 2104 PetscErrorCode PCFieldSplitGetDMSplits(PC pc,PetscBool* flg) 2105 { 2106 PC_FieldSplit *jac = (PC_FieldSplit*)pc->data; 2107 PetscBool isfs; 2108 PetscErrorCode ierr; 2109 2110 PetscFunctionBegin; 2111 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 2112 PetscValidPointer(flg,2); 2113 ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);CHKERRQ(ierr); 2114 if (isfs) { 2115 if(flg) *flg = jac->dm_splits; 2116 } 2117 PetscFunctionReturn(0); 2118 } 2119 2120 /* -------------------------------------------------------------------------------------*/ 2121 /*MC 2122 PCFIELDSPLIT - Preconditioner created by combining separate preconditioners for individual 2123 fields or groups of fields. See the users manual section "Solving Block Matrices" for more details. 2124 2125 To set options on the solvers for each block append -fieldsplit_ to all the PC 2126 options database keys. For example, -fieldsplit_pc_type ilu -fieldsplit_pc_factor_levels 1 2127 2128 To set the options on the solvers separate for each block call PCFieldSplitGetSubKSP() 2129 and set the options directly on the resulting KSP object 2130 2131 Level: intermediate 2132 2133 Options Database Keys: 2134 + -pc_fieldsplit_%d_fields <a,b,..> - indicates the fields to be used in the %d'th split 2135 . -pc_fieldsplit_default - automatically add any fields to additional splits that have not 2136 been supplied explicitly by -pc_fieldsplit_%d_fields 2137 . -pc_fieldsplit_block_size <bs> - size of block that defines fields (i.e. there are bs fields) 2138 . -pc_fieldsplit_type <additive,multiplicative,symmetric_multiplicative,schur> - type of relaxation or factorization splitting 2139 . -pc_fieldsplit_schur_precondition <self,selfp,user,a11,full> - default is a11 2140 . -pc_fieldsplit_detect_saddle_point - automatically finds rows with zero or negative diagonal and uses Schur complement with no preconditioner as the solver 2141 2142 - Options prefix for inner solvers when using Schur complement preconditioner are -fieldsplit_0_ and -fieldsplit_1_ 2143 for all other solvers they are -fieldsplit_%d_ for the dth field, use -fieldsplit_ for all fields 2144 2145 Notes: 2146 Use PCFieldSplitSetFields() to set fields defined by "strided" entries and PCFieldSplitSetIS() 2147 to define a field by an arbitrary collection of entries. 2148 2149 If no fields are set the default is used. The fields are defined by entries strided by bs, 2150 beginning at 0 then 1, etc to bs-1. The block size can be set with PCFieldSplitSetBlockSize(), 2151 if this is not called the block size defaults to the blocksize of the second matrix passed 2152 to KSPSetOperators()/PCSetOperators(). 2153 2154 $ For the Schur complement preconditioner if J = ( A00 A01 ) 2155 $ ( A10 A11 ) 2156 $ the preconditioner using full factorization is 2157 $ ( I -ksp(A00) A01 ) ( inv(A00) 0 ) ( I 0 ) 2158 $ ( 0 I ) ( 0 ksp(S) ) ( -A10 ksp(A00) I ) 2159 where the action of inv(A00) is applied using the KSP solver with prefix -fieldsplit_0_. S is the Schur complement 2160 $ S = A11 - A10 ksp(A00) A01 2161 which is usually dense and not stored explicitly. The action of ksp(S) is computed using the KSP solver with prefix -fieldsplit_splitname_ (where splitname was given 2162 in providing the SECOND split or 1 if not give). For PCFieldSplitGetKSP() when field number is 0, 2163 it returns the KSP associated with -fieldsplit_0_ while field number 1 gives -fieldsplit_1_ KSP. By default 2164 A11 is used to construct a preconditioner for S, use PCFieldSplitSetSchurPre() to turn on or off this 2165 option. You can use the preconditioner PCLSC to precondition the Schur complement with -fieldsplit_1_pc_type lsc. 2166 When option -fieldsplit_schur_precondition selfp is given, an approximation to S is assembled -- 2167 Sp = A11 - A10 inv(diag(A00)) A01, which has type AIJ and can be used with a variety of preconditioners 2168 (e.g., -fieldsplit_1_pc_type asm). 2169 The factorization type is set using -pc_fieldsplit_schur_fact_type <diag, lower, upper, full>. The full is shown above, 2170 diag gives 2171 $ ( inv(A00) 0 ) 2172 $ ( 0 -ksp(S) ) 2173 note that slightly counter intuitively there is a negative in front of the ksp(S) so that the preconditioner is positive definite. The lower factorization is the inverse of 2174 $ ( A00 0 ) 2175 $ ( A10 S ) 2176 where the inverses of A00 and S are applied using KSPs. The upper factorization is the inverse of 2177 $ ( A00 A01 ) 2178 $ ( 0 S ) 2179 where again the inverses of A00 and S are applied using KSPs. 2180 2181 If only one set of indices (one IS) is provided with PCFieldSplitSetIS() then the complement of that IS 2182 is used automatically for a second block. 2183 2184 The fieldsplit preconditioner cannot currently be used with the BAIJ or SBAIJ data formats if the blocksize is larger than 1. 2185 Generally it should be used with the AIJ format. 2186 2187 The forms of these preconditioners are closely related if not identical to forms derived as "Distributive Iterations", see, 2188 for example, page 294 in "Principles of Computational Fluid Dynamics" by Pieter Wesseling. Note that one can also use PCFIELDSPLIT 2189 inside a smoother resulting in "Distributive Smoothers". 2190 2191 Concepts: physics based preconditioners, block preconditioners 2192 2193 There is a nice discussion of block preconditioners in 2194 2195 [El08] A taxonomy and comparison of parallel block multi-level preconditioners for the incompressible Navier-Stokes equations 2196 Howard Elman, V.E. Howle, John Shadid, Robert Shuttleworth, Ray Tuminaro, Journal of Computational Physics 227 (2008) 1790--1808 2197 http://chess.cs.umd.edu/~elman/papers/tax.pdf 2198 2199 .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, Block_Preconditioners, PCLSC, 2200 PCFieldSplitGetSubKSP(), PCFieldSplitSetFields(), PCFieldSplitSetType(), PCFieldSplitSetIS(), PCFieldSplitSetSchurPre() 2201 M*/ 2202 2203 #undef __FUNCT__ 2204 #define __FUNCT__ "PCCreate_FieldSplit" 2205 PETSC_EXTERN PetscErrorCode PCCreate_FieldSplit(PC pc) 2206 { 2207 PetscErrorCode ierr; 2208 PC_FieldSplit *jac; 2209 2210 PetscFunctionBegin; 2211 ierr = PetscNewLog(pc,&jac);CHKERRQ(ierr); 2212 2213 jac->bs = -1; 2214 jac->nsplits = 0; 2215 jac->type = PC_COMPOSITE_MULTIPLICATIVE; 2216 jac->schurpre = PC_FIELDSPLIT_SCHUR_PRE_USER; /* Try user preconditioner first, fall back on diagonal */ 2217 jac->schurfactorization = PC_FIELDSPLIT_SCHUR_FACT_FULL; 2218 jac->dm_splits = PETSC_TRUE; 2219 2220 pc->data = (void*)jac; 2221 2222 pc->ops->apply = PCApply_FieldSplit; 2223 pc->ops->applytranspose = PCApplyTranspose_FieldSplit; 2224 pc->ops->setup = PCSetUp_FieldSplit; 2225 pc->ops->reset = PCReset_FieldSplit; 2226 pc->ops->destroy = PCDestroy_FieldSplit; 2227 pc->ops->setfromoptions = PCSetFromOptions_FieldSplit; 2228 pc->ops->view = PCView_FieldSplit; 2229 pc->ops->applyrichardson = 0; 2230 2231 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",PCFieldSplitGetSubKSP_FieldSplit);CHKERRQ(ierr); 2232 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetFields_C",PCFieldSplitSetFields_FieldSplit);CHKERRQ(ierr); 2233 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetIS_C",PCFieldSplitSetIS_FieldSplit);CHKERRQ(ierr); 2234 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetType_C",PCFieldSplitSetType_FieldSplit);CHKERRQ(ierr); 2235 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetBlockSize_C",PCFieldSplitSetBlockSize_FieldSplit);CHKERRQ(ierr); 2236 PetscFunctionReturn(0); 2237 } 2238 2239 2240 2241