xref: /petsc/src/ksp/pc/impls/bddc/bddc.c (revision ae9e683860ab9fa8b4d7d9eccf1547e9d8b3360d)
1 /* TODOLIST
2 
3    Solvers
4    - Add support for cholesky for coarse solver (similar to local solvers)
5    - Propagate ksp prefixes for solvers to mat objects?
6 
7    User interface
8    - ** DM attached to pc?
9 
10    Debugging output
11    - * Better management of verbosity levels of debugging output
12 
13    Extra
14    - *** Is it possible to work with PCBDDCGraph on boundary indices only (less memory consumed)?
15    - BDDC with MG framework?
16 
17    FETIDP
18    - Move FETIDP code to its own classes
19 
20    MATIS related operations contained in BDDC code
21    - Provide general case for subassembling
22 
23 */
24 
25 #include <../src/ksp/pc/impls/bddc/bddc.h> /*I "petscpc.h" I*/  /* includes for fortran wrappers */
26 #include <../src/ksp/pc/impls/bddc/bddcprivate.h>
27 #include <petscblaslapack.h>
28 
29 /* temporarily declare it */
30 PetscErrorCode PCApply_BDDC(PC,Vec,Vec);
31 
32 /* -------------------------------------------------------------------------- */
33 #undef __FUNCT__
34 #define __FUNCT__ "PCSetFromOptions_BDDC"
35 PetscErrorCode PCSetFromOptions_BDDC(PetscOptions *PetscOptionsObject,PC pc)
36 {
37   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
38   PetscErrorCode ierr;
39 
40   PetscFunctionBegin;
41   ierr = PetscOptionsHead(PetscOptionsObject,"BDDC options");CHKERRQ(ierr);
42   /* Verbose debugging */
43   ierr = PetscOptionsInt("-pc_bddc_check_level","Verbose output for PCBDDC (intended for debug)","none",pcbddc->dbg_flag,&pcbddc->dbg_flag,NULL);CHKERRQ(ierr);
44   /* Primal space cumstomization */
45   ierr = PetscOptionsBool("-pc_bddc_use_local_mat_graph","Use or not adjacency graph of local mat for interface analysis","none",pcbddc->use_local_adj,&pcbddc->use_local_adj,NULL);CHKERRQ(ierr);
46   ierr = PetscOptionsBool("-pc_bddc_use_vertices","Use or not corner dofs in coarse space","none",pcbddc->use_vertices,&pcbddc->use_vertices,NULL);CHKERRQ(ierr);
47   ierr = PetscOptionsBool("-pc_bddc_use_edges","Use or not edge constraints in coarse space","none",pcbddc->use_edges,&pcbddc->use_edges,NULL);CHKERRQ(ierr);
48   ierr = PetscOptionsBool("-pc_bddc_use_faces","Use or not face constraints in coarse space","none",pcbddc->use_faces,&pcbddc->use_faces,NULL);CHKERRQ(ierr);
49   ierr = PetscOptionsBool("-pc_bddc_use_true_nnsp","Use near null space attached to the matrix without modifications","none",pcbddc->use_nnsp_true,&pcbddc->use_nnsp_true,NULL);CHKERRQ(ierr);
50   ierr = PetscOptionsBool("-pc_bddc_use_qr_single","Use QR factorization for single constraints on cc (QR is used when multiple constraints are present)","none",pcbddc->use_qr_single,&pcbddc->use_qr_single,NULL);CHKERRQ(ierr);
51   /* Change of basis */
52   ierr = PetscOptionsBool("-pc_bddc_use_change_of_basis","Use or not internal change of basis on local edge nodes","none",pcbddc->use_change_of_basis,&pcbddc->use_change_of_basis,NULL);CHKERRQ(ierr);
53   ierr = PetscOptionsBool("-pc_bddc_use_change_on_faces","Use or not internal change of basis on local face nodes","none",pcbddc->use_change_on_faces,&pcbddc->use_change_on_faces,NULL);CHKERRQ(ierr);
54   if (!pcbddc->use_change_of_basis) {
55     pcbddc->use_change_on_faces = PETSC_FALSE;
56   }
57   /* Switch between M_2 (default) and M_3 preconditioners (as defined by C. Dohrmann in the ref. article) */
58   ierr = PetscOptionsBool("-pc_bddc_switch_static","Switch on static condensation ops around the interface preconditioner","none",pcbddc->switch_static,&pcbddc->switch_static,NULL);CHKERRQ(ierr);
59   ierr = PetscOptionsInt("-pc_bddc_coarse_redistribute","Number of procs where to redistribute coarse problem","none",pcbddc->redistribute_coarse,&pcbddc->redistribute_coarse,NULL);CHKERRQ(ierr);
60   ierr = PetscOptionsInt("-pc_bddc_coarsening_ratio","Set coarsening ratio used in multilevel coarsening","none",pcbddc->coarsening_ratio,&pcbddc->coarsening_ratio,NULL);CHKERRQ(ierr);
61   ierr = PetscOptionsInt("-pc_bddc_levels","Set maximum number of levels for multilevel","none",pcbddc->max_levels,&pcbddc->max_levels,NULL);CHKERRQ(ierr);
62   ierr = PetscOptionsBool("-pc_bddc_use_coarse_estimates","Use estimated eigenvalues for coarse problem","none",pcbddc->use_coarse_estimates,&pcbddc->use_coarse_estimates,NULL);CHKERRQ(ierr);
63   ierr = PetscOptionsBool("-pc_bddc_use_deluxe_scaling","Use deluxe scaling for BDDC","none",pcbddc->use_deluxe_scaling,&pcbddc->use_deluxe_scaling,NULL);CHKERRQ(ierr);
64   ierr = PetscOptionsBool("-pc_bddc_schur_rebuild","Whether or not the interface graph for Schur principal minors has to be rebuilt (i.e. define the interface without any adjacency)","none",pcbddc->sub_schurs_rebuild,&pcbddc->sub_schurs_rebuild,NULL);CHKERRQ(ierr);
65   ierr = PetscOptionsInt("-pc_bddc_schur_layers","Number of dofs' layers for the computation of principal minors (i.e. -1 uses all dofs)","none",pcbddc->sub_schurs_layers,&pcbddc->sub_schurs_layers,NULL);CHKERRQ(ierr);
66   ierr = PetscOptionsBool("-pc_bddc_schur_use_useradj","Whether or not the CSR graph specified by the user should be used for computing successive layers (default is to use adj of local mat)","none",pcbddc->sub_schurs_use_useradj,&pcbddc->sub_schurs_use_useradj,NULL);CHKERRQ(ierr);
67   ierr = PetscOptionsBool("-pc_bddc_deluxe_faster","Faster application of deluxe scaling (requires extra work during setup)","none",pcbddc->faster_deluxe,&pcbddc->faster_deluxe,NULL);CHKERRQ(ierr);
68   ierr = PetscOptionsReal("-pc_bddc_adaptive_threshold","Threshold to be used for adaptive selection of constraints","none",pcbddc->adaptive_threshold,&pcbddc->adaptive_threshold,NULL);CHKERRQ(ierr);
69   ierr = PetscOptionsInt("-pc_bddc_adaptive_nmin","Minimum number of constraints per connected components","none",pcbddc->adaptive_nmin,&pcbddc->adaptive_nmin,NULL);CHKERRQ(ierr);
70   ierr = PetscOptionsInt("-pc_bddc_adaptive_nmax","Maximum number of constraints per connected components","none",pcbddc->adaptive_nmax,&pcbddc->adaptive_nmax,NULL);CHKERRQ(ierr);
71   ierr = PetscOptionsBool("-pc_bddc_symmetric","Symmetric computation of primal basis functions","none",pcbddc->symmetric_primal,&pcbddc->symmetric_primal,NULL);CHKERRQ(ierr);
72   ierr = PetscOptionsInt("-pc_bddc_coarse_adj","Number of processors where to map the coarse adjacency list","none",pcbddc->coarse_adj_red,&pcbddc->coarse_adj_red,NULL);CHKERRQ(ierr);
73   ierr = PetscOptionsBool("-pc_bddc_benign_trick","Apply the benign subspace trick to a class of saddle point problems","none",pcbddc->benign_saddle_point,&pcbddc->benign_saddle_point,NULL);CHKERRQ(ierr);
74   ierr = PetscOptionsTail();CHKERRQ(ierr);
75   PetscFunctionReturn(0);
76 }
77 /* -------------------------------------------------------------------------- */
78 #undef __FUNCT__
79 #define __FUNCT__ "PCBDDCSetChangeOfBasisMat_BDDC"
80 static PetscErrorCode PCBDDCSetChangeOfBasisMat_BDDC(PC pc, Mat change)
81 {
82   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
83   PetscErrorCode ierr;
84 
85   PetscFunctionBegin;
86   ierr = MatDestroy(&pcbddc->user_ChangeOfBasisMatrix);CHKERRQ(ierr);
87   ierr = PetscObjectReference((PetscObject)change);CHKERRQ(ierr);
88   pcbddc->user_ChangeOfBasisMatrix = change;
89   PetscFunctionReturn(0);
90 }
91 #undef __FUNCT__
92 #define __FUNCT__ "PCBDDCSetChangeOfBasisMat"
93 /*@
94  PCBDDCSetChangeOfBasisMat - Set user defined change of basis for dofs
95 
96    Collective on PC
97 
98    Input Parameters:
99 +  pc - the preconditioning context
100 -  change - the change of basis matrix
101 
102    Level: intermediate
103 
104    Notes:
105 
106 .seealso: PCBDDC
107 @*/
108 PetscErrorCode PCBDDCSetChangeOfBasisMat(PC pc, Mat change)
109 {
110   PetscErrorCode ierr;
111 
112   PetscFunctionBegin;
113   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
114   PetscValidHeaderSpecific(change,MAT_CLASSID,2);
115   PetscCheckSameComm(pc,1,change,2);
116   if (pc->mat) {
117     PetscInt rows_c,cols_c,rows,cols;
118     ierr = MatGetSize(pc->mat,&rows,&cols);CHKERRQ(ierr);
119     ierr = MatGetSize(change,&rows_c,&cols_c);CHKERRQ(ierr);
120     if (rows_c != rows) {
121       SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Invalid number of rows for change of basis matrix! %d != %d",rows_c,rows);
122     }
123     if (cols_c != cols) {
124       SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Invalid number of columns for change of basis matrix! %d != %d",cols_c,cols);
125     }
126     ierr = MatGetLocalSize(pc->mat,&rows,&cols);CHKERRQ(ierr);
127     ierr = MatGetLocalSize(change,&rows_c,&cols_c);CHKERRQ(ierr);
128     if (rows_c != rows) {
129       SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Invalid number of local rows for change of basis matrix! %d != %d",rows_c,rows);
130     }
131     if (cols_c != cols) {
132       SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Invalid number of local columns for change of basis matrix! %d != %d",cols_c,cols);
133     }
134   }
135   ierr = PetscTryMethod(pc,"PCBDDCSetChangeOfBasisMat_C",(PC,Mat),(pc,change));CHKERRQ(ierr);
136   PetscFunctionReturn(0);
137 }
138 /* -------------------------------------------------------------------------- */
139 #undef __FUNCT__
140 #define __FUNCT__ "PCBDDCSetPrimalVerticesLocalIS_BDDC"
141 static PetscErrorCode PCBDDCSetPrimalVerticesLocalIS_BDDC(PC pc, IS PrimalVertices)
142 {
143   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
144   PetscErrorCode ierr;
145 
146   PetscFunctionBegin;
147   ierr = ISDestroy(&pcbddc->user_primal_vertices);CHKERRQ(ierr);
148   ierr = PetscObjectReference((PetscObject)PrimalVertices);CHKERRQ(ierr);
149   pcbddc->user_primal_vertices = PrimalVertices;
150   PetscFunctionReturn(0);
151 }
152 #undef __FUNCT__
153 #define __FUNCT__ "PCBDDCSetPrimalVerticesLocalIS"
154 /*@
155  PCBDDCSetPrimalVerticesLocalIS - Set additional user defined primal vertices in PCBDDC
156 
157    Collective
158 
159    Input Parameters:
160 +  pc - the preconditioning context
161 -  PrimalVertices - index set of primal vertices in local numbering (can be empty)
162 
163    Level: intermediate
164 
165    Notes:
166 
167 .seealso: PCBDDC
168 @*/
169 PetscErrorCode PCBDDCSetPrimalVerticesLocalIS(PC pc, IS PrimalVertices)
170 {
171   PetscErrorCode ierr;
172 
173   PetscFunctionBegin;
174   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
175   PetscValidHeaderSpecific(PrimalVertices,IS_CLASSID,2);
176   PetscCheckSameComm(pc,1,PrimalVertices,2);
177   ierr = PetscTryMethod(pc,"PCBDDCSetPrimalVerticesLocalIS_C",(PC,IS),(pc,PrimalVertices));CHKERRQ(ierr);
178   PetscFunctionReturn(0);
179 }
180 /* -------------------------------------------------------------------------- */
181 #undef __FUNCT__
182 #define __FUNCT__ "PCBDDCSetCoarseningRatio_BDDC"
183 static PetscErrorCode PCBDDCSetCoarseningRatio_BDDC(PC pc,PetscInt k)
184 {
185   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
186 
187   PetscFunctionBegin;
188   pcbddc->coarsening_ratio = k;
189   PetscFunctionReturn(0);
190 }
191 
192 #undef __FUNCT__
193 #define __FUNCT__ "PCBDDCSetCoarseningRatio"
194 /*@
195  PCBDDCSetCoarseningRatio - Set coarsening ratio used in multilevel
196 
197    Logically collective on PC
198 
199    Input Parameters:
200 +  pc - the preconditioning context
201 -  k - coarsening ratio (H/h at the coarser level)
202 
203    Options Database Keys:
204 .    -pc_bddc_coarsening_ratio
205 
206    Level: intermediate
207 
208    Notes:
209      Approximatively k subdomains at the finer level will be aggregated into a single subdomain at the coarser level
210 
211 .seealso: PCBDDC, PCBDDCSetLevels()
212 @*/
213 PetscErrorCode PCBDDCSetCoarseningRatio(PC pc,PetscInt k)
214 {
215   PetscErrorCode ierr;
216 
217   PetscFunctionBegin;
218   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
219   PetscValidLogicalCollectiveInt(pc,k,2);
220   ierr = PetscTryMethod(pc,"PCBDDCSetCoarseningRatio_C",(PC,PetscInt),(pc,k));CHKERRQ(ierr);
221   PetscFunctionReturn(0);
222 }
223 
224 /* The following functions (PCBDDCSetUseExactDirichlet PCBDDCSetLevel) are not public */
225 #undef __FUNCT__
226 #define __FUNCT__ "PCBDDCSetUseExactDirichlet_BDDC"
227 static PetscErrorCode PCBDDCSetUseExactDirichlet_BDDC(PC pc,PetscBool flg)
228 {
229   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
230 
231   PetscFunctionBegin;
232   pcbddc->use_exact_dirichlet_trick = flg;
233   PetscFunctionReturn(0);
234 }
235 
236 #undef __FUNCT__
237 #define __FUNCT__ "PCBDDCSetUseExactDirichlet"
238 PetscErrorCode PCBDDCSetUseExactDirichlet(PC pc,PetscBool flg)
239 {
240   PetscErrorCode ierr;
241 
242   PetscFunctionBegin;
243   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
244   PetscValidLogicalCollectiveBool(pc,flg,2);
245   ierr = PetscTryMethod(pc,"PCBDDCSetUseExactDirichlet_C",(PC,PetscBool),(pc,flg));CHKERRQ(ierr);
246   PetscFunctionReturn(0);
247 }
248 
249 #undef __FUNCT__
250 #define __FUNCT__ "PCBDDCSetLevel_BDDC"
251 static PetscErrorCode PCBDDCSetLevel_BDDC(PC pc,PetscInt level)
252 {
253   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
254 
255   PetscFunctionBegin;
256   pcbddc->current_level = level;
257   PetscFunctionReturn(0);
258 }
259 
260 #undef __FUNCT__
261 #define __FUNCT__ "PCBDDCSetLevel"
262 PetscErrorCode PCBDDCSetLevel(PC pc,PetscInt level)
263 {
264   PetscErrorCode ierr;
265 
266   PetscFunctionBegin;
267   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
268   PetscValidLogicalCollectiveInt(pc,level,2);
269   ierr = PetscTryMethod(pc,"PCBDDCSetLevel_C",(PC,PetscInt),(pc,level));CHKERRQ(ierr);
270   PetscFunctionReturn(0);
271 }
272 
273 #undef __FUNCT__
274 #define __FUNCT__ "PCBDDCSetLevels_BDDC"
275 static PetscErrorCode PCBDDCSetLevels_BDDC(PC pc,PetscInt levels)
276 {
277   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
278 
279   PetscFunctionBegin;
280   pcbddc->max_levels = levels;
281   PetscFunctionReturn(0);
282 }
283 
284 #undef __FUNCT__
285 #define __FUNCT__ "PCBDDCSetLevels"
286 /*@
287  PCBDDCSetLevels - Sets the maximum number of levels for multilevel
288 
289    Logically collective on PC
290 
291    Input Parameters:
292 +  pc - the preconditioning context
293 -  levels - the maximum number of levels (max 9)
294 
295    Options Database Keys:
296 .    -pc_bddc_levels
297 
298    Level: intermediate
299 
300    Notes:
301      Default value is 0, i.e. traditional one-level BDDC
302 
303 .seealso: PCBDDC, PCBDDCSetCoarseningRatio()
304 @*/
305 PetscErrorCode PCBDDCSetLevels(PC pc,PetscInt levels)
306 {
307   PetscErrorCode ierr;
308 
309   PetscFunctionBegin;
310   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
311   PetscValidLogicalCollectiveInt(pc,levels,2);
312   if (levels > 99) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Maximum number of levels for bddc is 99\n");
313   ierr = PetscTryMethod(pc,"PCBDDCSetLevels_C",(PC,PetscInt),(pc,levels));CHKERRQ(ierr);
314   PetscFunctionReturn(0);
315 }
316 /* -------------------------------------------------------------------------- */
317 
318 #undef __FUNCT__
319 #define __FUNCT__ "PCBDDCSetNullSpace_BDDC"
320 static PetscErrorCode PCBDDCSetNullSpace_BDDC(PC pc,MatNullSpace NullSpace)
321 {
322   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
323   PetscErrorCode ierr;
324 
325   PetscFunctionBegin;
326   ierr = PetscObjectReference((PetscObject)NullSpace);CHKERRQ(ierr);
327   ierr = MatNullSpaceDestroy(&pcbddc->NullSpace);CHKERRQ(ierr);
328   pcbddc->NullSpace = NullSpace;
329   PetscFunctionReturn(0);
330 }
331 
332 #undef __FUNCT__
333 #define __FUNCT__ "PCBDDCSetNullSpace"
334 /*@
335  PCBDDCSetNullSpace - Set nullspace for BDDC operator
336 
337    Logically collective on PC and MatNullSpace
338 
339    Input Parameters:
340 +  pc - the preconditioning context
341 -  NullSpace - Null space of the linear operator to be preconditioned (Pmat)
342 
343    Level: intermediate
344 
345    Notes:
346 
347 .seealso: PCBDDC
348 @*/
349 PetscErrorCode PCBDDCSetNullSpace(PC pc,MatNullSpace NullSpace)
350 {
351   PetscErrorCode ierr;
352 
353   PetscFunctionBegin;
354   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
355   PetscValidHeaderSpecific(NullSpace,MAT_NULLSPACE_CLASSID,2);
356   PetscCheckSameComm(pc,1,NullSpace,2);
357   ierr = PetscTryMethod(pc,"PCBDDCSetNullSpace_C",(PC,MatNullSpace),(pc,NullSpace));CHKERRQ(ierr);
358   PetscFunctionReturn(0);
359 }
360 /* -------------------------------------------------------------------------- */
361 
362 #undef __FUNCT__
363 #define __FUNCT__ "PCBDDCSetDirichletBoundaries_BDDC"
364 static PetscErrorCode PCBDDCSetDirichletBoundaries_BDDC(PC pc,IS DirichletBoundaries)
365 {
366   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
367   PetscErrorCode ierr;
368 
369   PetscFunctionBegin;
370   /* last user setting takes precendence -> destroy any other customization */
371   ierr = ISDestroy(&pcbddc->DirichletBoundariesLocal);CHKERRQ(ierr);
372   ierr = ISDestroy(&pcbddc->DirichletBoundaries);CHKERRQ(ierr);
373   ierr = PetscObjectReference((PetscObject)DirichletBoundaries);CHKERRQ(ierr);
374   pcbddc->DirichletBoundaries = DirichletBoundaries;
375   pcbddc->recompute_topography = PETSC_TRUE;
376   PetscFunctionReturn(0);
377 }
378 
379 #undef __FUNCT__
380 #define __FUNCT__ "PCBDDCSetDirichletBoundaries"
381 /*@
382  PCBDDCSetDirichletBoundaries - Set IS defining Dirichlet boundaries for the global problem.
383 
384    Collective
385 
386    Input Parameters:
387 +  pc - the preconditioning context
388 -  DirichletBoundaries - parallel IS defining the Dirichlet boundaries
389 
390    Level: intermediate
391 
392    Notes:
393      Provide the information if you used MatZeroRows/Columns routines. Any process can list any global node
394 
395 .seealso: PCBDDC, PCBDDCSetDirichletBoundariesLocal(), MatZeroRows(), MatZeroRowsColumns()
396 @*/
397 PetscErrorCode PCBDDCSetDirichletBoundaries(PC pc,IS DirichletBoundaries)
398 {
399   PetscErrorCode ierr;
400 
401   PetscFunctionBegin;
402   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
403   PetscValidHeaderSpecific(DirichletBoundaries,IS_CLASSID,2);
404   PetscCheckSameComm(pc,1,DirichletBoundaries,2);
405   ierr = PetscTryMethod(pc,"PCBDDCSetDirichletBoundaries_C",(PC,IS),(pc,DirichletBoundaries));CHKERRQ(ierr);
406   PetscFunctionReturn(0);
407 }
408 /* -------------------------------------------------------------------------- */
409 
410 #undef __FUNCT__
411 #define __FUNCT__ "PCBDDCSetDirichletBoundariesLocal_BDDC"
412 static PetscErrorCode PCBDDCSetDirichletBoundariesLocal_BDDC(PC pc,IS DirichletBoundaries)
413 {
414   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
415   PetscErrorCode ierr;
416 
417   PetscFunctionBegin;
418   /* last user setting takes precendence -> destroy any other customization */
419   ierr = ISDestroy(&pcbddc->DirichletBoundariesLocal);CHKERRQ(ierr);
420   ierr = ISDestroy(&pcbddc->DirichletBoundaries);CHKERRQ(ierr);
421   ierr = PetscObjectReference((PetscObject)DirichletBoundaries);CHKERRQ(ierr);
422   pcbddc->DirichletBoundariesLocal = DirichletBoundaries;
423   pcbddc->recompute_topography = PETSC_TRUE;
424   PetscFunctionReturn(0);
425 }
426 
427 #undef __FUNCT__
428 #define __FUNCT__ "PCBDDCSetDirichletBoundariesLocal"
429 /*@
430  PCBDDCSetDirichletBoundariesLocal - Set IS defining Dirichlet boundaries for the global problem in local ordering.
431 
432    Collective
433 
434    Input Parameters:
435 +  pc - the preconditioning context
436 -  DirichletBoundaries - parallel IS defining the Dirichlet boundaries (in local ordering)
437 
438    Level: intermediate
439 
440    Notes:
441 
442 .seealso: PCBDDC, PCBDDCSetDirichletBoundaries(), MatZeroRows(), MatZeroRowsColumns()
443 @*/
444 PetscErrorCode PCBDDCSetDirichletBoundariesLocal(PC pc,IS DirichletBoundaries)
445 {
446   PetscErrorCode ierr;
447 
448   PetscFunctionBegin;
449   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
450   PetscValidHeaderSpecific(DirichletBoundaries,IS_CLASSID,2);
451   PetscCheckSameComm(pc,1,DirichletBoundaries,2);
452   ierr = PetscTryMethod(pc,"PCBDDCSetDirichletBoundariesLocal_C",(PC,IS),(pc,DirichletBoundaries));CHKERRQ(ierr);
453   PetscFunctionReturn(0);
454 }
455 /* -------------------------------------------------------------------------- */
456 
457 #undef __FUNCT__
458 #define __FUNCT__ "PCBDDCSetNeumannBoundaries_BDDC"
459 static PetscErrorCode PCBDDCSetNeumannBoundaries_BDDC(PC pc,IS NeumannBoundaries)
460 {
461   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
462   PetscErrorCode ierr;
463 
464   PetscFunctionBegin;
465   /* last user setting takes precendence -> destroy any other customization */
466   ierr = ISDestroy(&pcbddc->NeumannBoundariesLocal);CHKERRQ(ierr);
467   ierr = ISDestroy(&pcbddc->NeumannBoundaries);CHKERRQ(ierr);
468   ierr = PetscObjectReference((PetscObject)NeumannBoundaries);CHKERRQ(ierr);
469   pcbddc->NeumannBoundaries = NeumannBoundaries;
470   pcbddc->recompute_topography = PETSC_TRUE;
471   PetscFunctionReturn(0);
472 }
473 
474 #undef __FUNCT__
475 #define __FUNCT__ "PCBDDCSetNeumannBoundaries"
476 /*@
477  PCBDDCSetNeumannBoundaries - Set IS defining Neumann boundaries for the global problem.
478 
479    Collective
480 
481    Input Parameters:
482 +  pc - the preconditioning context
483 -  NeumannBoundaries - parallel IS defining the Neumann boundaries
484 
485    Level: intermediate
486 
487    Notes:
488      Any process can list any global node
489 
490 .seealso: PCBDDC, PCBDDCSetNeumannBoundariesLocal()
491 @*/
492 PetscErrorCode PCBDDCSetNeumannBoundaries(PC pc,IS NeumannBoundaries)
493 {
494   PetscErrorCode ierr;
495 
496   PetscFunctionBegin;
497   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
498   PetscValidHeaderSpecific(NeumannBoundaries,IS_CLASSID,2);
499   PetscCheckSameComm(pc,1,NeumannBoundaries,2);
500   ierr = PetscTryMethod(pc,"PCBDDCSetNeumannBoundaries_C",(PC,IS),(pc,NeumannBoundaries));CHKERRQ(ierr);
501   PetscFunctionReturn(0);
502 }
503 /* -------------------------------------------------------------------------- */
504 
505 #undef __FUNCT__
506 #define __FUNCT__ "PCBDDCSetNeumannBoundariesLocal_BDDC"
507 static PetscErrorCode PCBDDCSetNeumannBoundariesLocal_BDDC(PC pc,IS NeumannBoundaries)
508 {
509   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
510   PetscErrorCode ierr;
511 
512   PetscFunctionBegin;
513   /* last user setting takes precendence -> destroy any other customization */
514   ierr = ISDestroy(&pcbddc->NeumannBoundariesLocal);CHKERRQ(ierr);
515   ierr = ISDestroy(&pcbddc->NeumannBoundaries);CHKERRQ(ierr);
516   ierr = PetscObjectReference((PetscObject)NeumannBoundaries);CHKERRQ(ierr);
517   pcbddc->NeumannBoundariesLocal = NeumannBoundaries;
518   pcbddc->recompute_topography = PETSC_TRUE;
519   PetscFunctionReturn(0);
520 }
521 
522 #undef __FUNCT__
523 #define __FUNCT__ "PCBDDCSetNeumannBoundariesLocal"
524 /*@
525  PCBDDCSetNeumannBoundariesLocal - Set IS defining Neumann boundaries for the global problem in local ordering.
526 
527    Collective
528 
529    Input Parameters:
530 +  pc - the preconditioning context
531 -  NeumannBoundaries - parallel IS defining the subdomain part of Neumann boundaries (in local ordering)
532 
533    Level: intermediate
534 
535    Notes:
536 
537 .seealso: PCBDDC, PCBDDCSetNeumannBoundaries()
538 @*/
539 PetscErrorCode PCBDDCSetNeumannBoundariesLocal(PC pc,IS NeumannBoundaries)
540 {
541   PetscErrorCode ierr;
542 
543   PetscFunctionBegin;
544   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
545   PetscValidHeaderSpecific(NeumannBoundaries,IS_CLASSID,2);
546   PetscCheckSameComm(pc,1,NeumannBoundaries,2);
547   ierr = PetscTryMethod(pc,"PCBDDCSetNeumannBoundariesLocal_C",(PC,IS),(pc,NeumannBoundaries));CHKERRQ(ierr);
548   PetscFunctionReturn(0);
549 }
550 /* -------------------------------------------------------------------------- */
551 
552 #undef __FUNCT__
553 #define __FUNCT__ "PCBDDCGetDirichletBoundaries_BDDC"
554 static PetscErrorCode PCBDDCGetDirichletBoundaries_BDDC(PC pc,IS *DirichletBoundaries)
555 {
556   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
557 
558   PetscFunctionBegin;
559   *DirichletBoundaries = pcbddc->DirichletBoundaries;
560   PetscFunctionReturn(0);
561 }
562 
563 #undef __FUNCT__
564 #define __FUNCT__ "PCBDDCGetDirichletBoundaries"
565 /*@
566  PCBDDCGetDirichletBoundaries - Get parallel IS for Dirichlet boundaries
567 
568    Collective
569 
570    Input Parameters:
571 .  pc - the preconditioning context
572 
573    Output Parameters:
574 .  DirichletBoundaries - index set defining the Dirichlet boundaries
575 
576    Level: intermediate
577 
578    Notes:
579      The IS returned (if any) is the same passed in earlier by the user with PCBDDCSetDirichletBoundaries
580 
581 .seealso: PCBDDC
582 @*/
583 PetscErrorCode PCBDDCGetDirichletBoundaries(PC pc,IS *DirichletBoundaries)
584 {
585   PetscErrorCode ierr;
586 
587   PetscFunctionBegin;
588   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
589   ierr = PetscUseMethod(pc,"PCBDDCGetDirichletBoundaries_C",(PC,IS*),(pc,DirichletBoundaries));CHKERRQ(ierr);
590   PetscFunctionReturn(0);
591 }
592 /* -------------------------------------------------------------------------- */
593 
594 #undef __FUNCT__
595 #define __FUNCT__ "PCBDDCGetDirichletBoundariesLocal_BDDC"
596 static PetscErrorCode PCBDDCGetDirichletBoundariesLocal_BDDC(PC pc,IS *DirichletBoundaries)
597 {
598   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
599 
600   PetscFunctionBegin;
601   *DirichletBoundaries = pcbddc->DirichletBoundariesLocal;
602   PetscFunctionReturn(0);
603 }
604 
605 #undef __FUNCT__
606 #define __FUNCT__ "PCBDDCGetDirichletBoundariesLocal"
607 /*@
608  PCBDDCGetDirichletBoundariesLocal - Get parallel IS for Dirichlet boundaries (in local ordering)
609 
610    Collective
611 
612    Input Parameters:
613 .  pc - the preconditioning context
614 
615    Output Parameters:
616 .  DirichletBoundaries - index set defining the subdomain part of Dirichlet boundaries
617 
618    Level: intermediate
619 
620    Notes:
621      The IS returned could be the same passed in earlier by the user (if provided with PCBDDCSetDirichletBoundariesLocal) or a global-to-local map of the global IS (if provided with PCBDDCSetDirichletBoundaries).
622           In the latter case, the IS will be available after PCSetUp.
623 
624 .seealso: PCBDDC
625 @*/
626 PetscErrorCode PCBDDCGetDirichletBoundariesLocal(PC pc,IS *DirichletBoundaries)
627 {
628   PetscErrorCode ierr;
629 
630   PetscFunctionBegin;
631   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
632   ierr = PetscUseMethod(pc,"PCBDDCGetDirichletBoundariesLocal_C",(PC,IS*),(pc,DirichletBoundaries));CHKERRQ(ierr);
633   PetscFunctionReturn(0);
634 }
635 /* -------------------------------------------------------------------------- */
636 
637 #undef __FUNCT__
638 #define __FUNCT__ "PCBDDCGetNeumannBoundaries_BDDC"
639 static PetscErrorCode PCBDDCGetNeumannBoundaries_BDDC(PC pc,IS *NeumannBoundaries)
640 {
641   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
642 
643   PetscFunctionBegin;
644   *NeumannBoundaries = pcbddc->NeumannBoundaries;
645   PetscFunctionReturn(0);
646 }
647 
648 #undef __FUNCT__
649 #define __FUNCT__ "PCBDDCGetNeumannBoundaries"
650 /*@
651  PCBDDCGetNeumannBoundaries - Get parallel IS for Neumann boundaries
652 
653    Collective
654 
655    Input Parameters:
656 .  pc - the preconditioning context
657 
658    Output Parameters:
659 .  NeumannBoundaries - index set defining the Neumann boundaries
660 
661    Level: intermediate
662 
663    Notes:
664      The IS returned (if any) is the same passed in earlier by the user with PCBDDCSetNeumannBoundaries
665 
666 .seealso: PCBDDC
667 @*/
668 PetscErrorCode PCBDDCGetNeumannBoundaries(PC pc,IS *NeumannBoundaries)
669 {
670   PetscErrorCode ierr;
671 
672   PetscFunctionBegin;
673   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
674   ierr = PetscUseMethod(pc,"PCBDDCGetNeumannBoundaries_C",(PC,IS*),(pc,NeumannBoundaries));CHKERRQ(ierr);
675   PetscFunctionReturn(0);
676 }
677 /* -------------------------------------------------------------------------- */
678 
679 #undef __FUNCT__
680 #define __FUNCT__ "PCBDDCGetNeumannBoundariesLocal_BDDC"
681 static PetscErrorCode PCBDDCGetNeumannBoundariesLocal_BDDC(PC pc,IS *NeumannBoundaries)
682 {
683   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
684 
685   PetscFunctionBegin;
686   *NeumannBoundaries = pcbddc->NeumannBoundariesLocal;
687   PetscFunctionReturn(0);
688 }
689 
690 #undef __FUNCT__
691 #define __FUNCT__ "PCBDDCGetNeumannBoundariesLocal"
692 /*@
693  PCBDDCGetNeumannBoundariesLocal - Get parallel IS for Neumann boundaries (in local ordering)
694 
695    Collective
696 
697    Input Parameters:
698 .  pc - the preconditioning context
699 
700    Output Parameters:
701 .  NeumannBoundaries - index set defining the subdomain part of Neumann boundaries
702 
703    Level: intermediate
704 
705    Notes:
706      The IS returned could be the same passed in earlier by the user (if provided with PCBDDCSetNeumannBoundariesLocal) or a global-to-local map of the global IS (if provided with PCBDDCSetNeumannBoundaries).
707           In the latter case, the IS will be available after PCSetUp.
708 
709 .seealso: PCBDDC
710 @*/
711 PetscErrorCode PCBDDCGetNeumannBoundariesLocal(PC pc,IS *NeumannBoundaries)
712 {
713   PetscErrorCode ierr;
714 
715   PetscFunctionBegin;
716   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
717   ierr = PetscUseMethod(pc,"PCBDDCGetNeumannBoundariesLocal_C",(PC,IS*),(pc,NeumannBoundaries));CHKERRQ(ierr);
718   PetscFunctionReturn(0);
719 }
720 /* -------------------------------------------------------------------------- */
721 
722 #undef __FUNCT__
723 #define __FUNCT__ "PCBDDCSetLocalAdjacencyGraph_BDDC"
724 static PetscErrorCode PCBDDCSetLocalAdjacencyGraph_BDDC(PC pc, PetscInt nvtxs,const PetscInt xadj[],const PetscInt adjncy[], PetscCopyMode copymode)
725 {
726   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
727   PCBDDCGraph    mat_graph = pcbddc->mat_graph;
728   PetscErrorCode ierr;
729 
730   PetscFunctionBegin;
731   /* free old CSR */
732   ierr = PCBDDCGraphResetCSR(mat_graph);CHKERRQ(ierr);
733   /* TODO: PCBDDCGraphSetAdjacency */
734   /* get CSR into graph structure */
735   if (copymode == PETSC_COPY_VALUES) {
736     ierr = PetscMalloc1(nvtxs+1,&mat_graph->xadj);CHKERRQ(ierr);
737     ierr = PetscMalloc1(xadj[nvtxs],&mat_graph->adjncy);CHKERRQ(ierr);
738     ierr = PetscMemcpy(mat_graph->xadj,xadj,(nvtxs+1)*sizeof(PetscInt));CHKERRQ(ierr);
739     ierr = PetscMemcpy(mat_graph->adjncy,adjncy,xadj[nvtxs]*sizeof(PetscInt));CHKERRQ(ierr);
740   } else if (copymode == PETSC_OWN_POINTER) {
741     mat_graph->xadj = (PetscInt*)xadj;
742     mat_graph->adjncy = (PetscInt*)adjncy;
743   }
744   mat_graph->nvtxs_csr = nvtxs;
745   PetscFunctionReturn(0);
746 }
747 
748 #undef __FUNCT__
749 #define __FUNCT__ "PCBDDCSetLocalAdjacencyGraph"
750 /*@
751  PCBDDCSetLocalAdjacencyGraph - Set adjacency structure (CSR graph) of the local matrix
752 
753    Not collective
754 
755    Input Parameters:
756 +  pc - the preconditioning context
757 .  nvtxs - number of local vertices of the graph (i.e., the size of the local problem)
758 .  xadj, adjncy - the CSR graph
759 -  copymode - either PETSC_COPY_VALUES or PETSC_OWN_POINTER.
760 
761    Level: intermediate
762 
763    Notes:
764 
765 .seealso: PCBDDC,PetscCopyMode
766 @*/
767 PetscErrorCode PCBDDCSetLocalAdjacencyGraph(PC pc,PetscInt nvtxs,const PetscInt xadj[],const PetscInt adjncy[], PetscCopyMode copymode)
768 {
769   void (*f)(void) = 0;
770   PetscErrorCode ierr;
771 
772   PetscFunctionBegin;
773   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
774   PetscValidIntPointer(xadj,3);
775   PetscValidIntPointer(adjncy,4);
776   if (copymode != PETSC_COPY_VALUES && copymode != PETSC_OWN_POINTER) {
777     SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_SUP,"Unsupported copy mode %d in %s\n",copymode,__FUNCT__);
778   }
779   ierr = PetscTryMethod(pc,"PCBDDCSetLocalAdjacencyGraph_C",(PC,PetscInt,const PetscInt[],const PetscInt[],PetscCopyMode),(pc,nvtxs,xadj,adjncy,copymode));CHKERRQ(ierr);
780   /* free arrays if PCBDDC is not the PC type */
781   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCBDDCSetLocalAdjacencyGraph_C",&f);CHKERRQ(ierr);
782   if (!f && copymode == PETSC_OWN_POINTER) {
783     ierr = PetscFree(xadj);CHKERRQ(ierr);
784     ierr = PetscFree(adjncy);CHKERRQ(ierr);
785   }
786   PetscFunctionReturn(0);
787 }
788 /* -------------------------------------------------------------------------- */
789 
790 #undef __FUNCT__
791 #define __FUNCT__ "PCBDDCSetDofsSplittingLocal_BDDC"
792 static PetscErrorCode PCBDDCSetDofsSplittingLocal_BDDC(PC pc,PetscInt n_is, IS ISForDofs[])
793 {
794   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
795   PetscInt i;
796   PetscErrorCode ierr;
797 
798   PetscFunctionBegin;
799   /* Destroy ISes if they were already set */
800   for (i=0;i<pcbddc->n_ISForDofsLocal;i++) {
801     ierr = ISDestroy(&pcbddc->ISForDofsLocal[i]);CHKERRQ(ierr);
802   }
803   ierr = PetscFree(pcbddc->ISForDofsLocal);CHKERRQ(ierr);
804   /* last user setting takes precendence -> destroy any other customization */
805   for (i=0;i<pcbddc->n_ISForDofs;i++) {
806     ierr = ISDestroy(&pcbddc->ISForDofs[i]);CHKERRQ(ierr);
807   }
808   ierr = PetscFree(pcbddc->ISForDofs);CHKERRQ(ierr);
809   pcbddc->n_ISForDofs = 0;
810   /* allocate space then set */
811   if (n_is) {
812     ierr = PetscMalloc1(n_is,&pcbddc->ISForDofsLocal);CHKERRQ(ierr);
813   }
814   for (i=0;i<n_is;i++) {
815     ierr = PetscObjectReference((PetscObject)ISForDofs[i]);CHKERRQ(ierr);
816     pcbddc->ISForDofsLocal[i]=ISForDofs[i];
817   }
818   pcbddc->n_ISForDofsLocal=n_is;
819   if (n_is) pcbddc->user_provided_isfordofs = PETSC_TRUE;
820   pcbddc->recompute_topography = PETSC_TRUE;
821   PetscFunctionReturn(0);
822 }
823 
824 #undef __FUNCT__
825 #define __FUNCT__ "PCBDDCSetDofsSplittingLocal"
826 /*@
827  PCBDDCSetDofsSplittingLocal - Set index sets defining fields of the local subdomain matrix
828 
829    Collective
830 
831    Input Parameters:
832 +  pc - the preconditioning context
833 .  n_is - number of index sets defining the fields
834 -  ISForDofs - array of IS describing the fields in local ordering
835 
836    Level: intermediate
837 
838    Notes:
839      n_is should be the same among processes. Not all nodes need to be listed: unlisted nodes will belong to the complement field.
840 
841 .seealso: PCBDDC
842 @*/
843 PetscErrorCode PCBDDCSetDofsSplittingLocal(PC pc,PetscInt n_is, IS ISForDofs[])
844 {
845   PetscInt       i;
846   PetscErrorCode ierr;
847 
848   PetscFunctionBegin;
849   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
850   PetscValidLogicalCollectiveInt(pc,n_is,2);
851   for (i=0;i<n_is;i++) {
852     PetscCheckSameComm(pc,1,ISForDofs[i],3);
853     PetscValidHeaderSpecific(ISForDofs[i],IS_CLASSID,3);
854   }
855   ierr = PetscTryMethod(pc,"PCBDDCSetDofsSplittingLocal_C",(PC,PetscInt,IS[]),(pc,n_is,ISForDofs));CHKERRQ(ierr);
856   PetscFunctionReturn(0);
857 }
858 /* -------------------------------------------------------------------------- */
859 
860 #undef __FUNCT__
861 #define __FUNCT__ "PCBDDCSetDofsSplitting_BDDC"
862 static PetscErrorCode PCBDDCSetDofsSplitting_BDDC(PC pc,PetscInt n_is, IS ISForDofs[])
863 {
864   PC_BDDC  *pcbddc = (PC_BDDC*)pc->data;
865   PetscInt i;
866   PetscErrorCode ierr;
867 
868   PetscFunctionBegin;
869   /* Destroy ISes if they were already set */
870   for (i=0;i<pcbddc->n_ISForDofs;i++) {
871     ierr = ISDestroy(&pcbddc->ISForDofs[i]);CHKERRQ(ierr);
872   }
873   ierr = PetscFree(pcbddc->ISForDofs);CHKERRQ(ierr);
874   /* last user setting takes precendence -> destroy any other customization */
875   for (i=0;i<pcbddc->n_ISForDofsLocal;i++) {
876     ierr = ISDestroy(&pcbddc->ISForDofsLocal[i]);CHKERRQ(ierr);
877   }
878   ierr = PetscFree(pcbddc->ISForDofsLocal);CHKERRQ(ierr);
879   pcbddc->n_ISForDofsLocal = 0;
880   /* allocate space then set */
881   if (n_is) {
882     ierr = PetscMalloc1(n_is,&pcbddc->ISForDofs);CHKERRQ(ierr);
883   }
884   for (i=0;i<n_is;i++) {
885     ierr = PetscObjectReference((PetscObject)ISForDofs[i]);CHKERRQ(ierr);
886     pcbddc->ISForDofs[i]=ISForDofs[i];
887   }
888   pcbddc->n_ISForDofs=n_is;
889   if (n_is) pcbddc->user_provided_isfordofs = PETSC_TRUE;
890   pcbddc->recompute_topography = PETSC_TRUE;
891   PetscFunctionReturn(0);
892 }
893 
894 #undef __FUNCT__
895 #define __FUNCT__ "PCBDDCSetDofsSplitting"
896 /*@
897  PCBDDCSetDofsSplitting - Set index sets defining fields of the global matrix
898 
899    Collective
900 
901    Input Parameters:
902 +  pc - the preconditioning context
903 .  n_is - number of index sets defining the fields
904 -  ISForDofs - array of IS describing the fields in global ordering
905 
906    Level: intermediate
907 
908    Notes:
909      Any process can list any global node. Not all nodes need to be listed: unlisted nodes will belong to the complement field.
910 
911 .seealso: PCBDDC
912 @*/
913 PetscErrorCode PCBDDCSetDofsSplitting(PC pc,PetscInt n_is, IS ISForDofs[])
914 {
915   PetscInt       i;
916   PetscErrorCode ierr;
917 
918   PetscFunctionBegin;
919   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
920   PetscValidLogicalCollectiveInt(pc,n_is,2);
921   for (i=0;i<n_is;i++) {
922     PetscCheckSameComm(pc,1,ISForDofs[i],3);
923     PetscValidHeaderSpecific(ISForDofs[i],IS_CLASSID,3);
924   }
925   ierr = PetscTryMethod(pc,"PCBDDCSetDofsSplitting_C",(PC,PetscInt,IS[]),(pc,n_is,ISForDofs));CHKERRQ(ierr);
926   PetscFunctionReturn(0);
927 }
928 
929 /* -------------------------------------------------------------------------- */
930 #undef __FUNCT__
931 #define __FUNCT__ "PCPreSolve_BDDC"
932 /* -------------------------------------------------------------------------- */
933 /*
934    PCPreSolve_BDDC - Changes the right hand side and (if necessary) the initial
935                      guess if a transformation of basis approach has been selected.
936 
937    Input Parameter:
938 +  pc - the preconditioner contex
939 
940    Application Interface Routine: PCPreSolve()
941 
942    Notes:
943      The interface routine PCPreSolve() is not usually called directly by
944    the user, but instead is called by KSPSolve().
945 */
946 static PetscErrorCode PCPreSolve_BDDC(PC pc, KSP ksp, Vec rhs, Vec x)
947 {
948   PetscErrorCode ierr;
949   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
950   PC_IS          *pcis = (PC_IS*)(pc->data);
951   Vec            used_vec;
952   PetscBool      copy_rhs = PETSC_TRUE;
953 
954   PetscFunctionBegin;
955   /* if we are working with cg, one dirichlet solve can be avoided during Krylov iterations */
956   if (ksp) {
957     PetscBool iscg;
958     ierr = PetscObjectTypeCompare((PetscObject)ksp,KSPCG,&iscg);CHKERRQ(ierr);
959     if (!iscg) {
960       ierr = PCBDDCSetUseExactDirichlet(pc,PETSC_FALSE);CHKERRQ(ierr);
961     }
962   }
963   /* Creates parallel work vectors used in presolve */
964   if (!pcbddc->original_rhs) {
965     ierr = VecDuplicate(pcis->vec1_global,&pcbddc->original_rhs);CHKERRQ(ierr);
966   }
967   if (!pcbddc->temp_solution) {
968     ierr = VecDuplicate(pcis->vec1_global,&pcbddc->temp_solution);CHKERRQ(ierr);
969   }
970 
971   if (x) {
972     ierr = PetscObjectReference((PetscObject)x);CHKERRQ(ierr);
973     used_vec = x;
974   } else { /* it can only happen when calling PCBDDCMatFETIDPGetRHS */
975     ierr = PetscObjectReference((PetscObject)pcbddc->temp_solution);CHKERRQ(ierr);
976     used_vec = pcbddc->temp_solution;
977     ierr = VecSet(used_vec,0.0);CHKERRQ(ierr);
978   }
979 
980   /* hack into ksp data structure since PCPreSolve comes earlier than setting to zero the guess in src/ksp/ksp/interface/itfunc.c */
981   if (ksp) {
982     /* store the flag for the initial guess since it will be restored back during PCPostSolve_BDDC */
983     ierr = KSPGetInitialGuessNonzero(ksp,&pcbddc->ksp_guess_nonzero);CHKERRQ(ierr);
984     if (!pcbddc->ksp_guess_nonzero) {
985       ierr = VecSet(used_vec,0.0);CHKERRQ(ierr);
986     }
987   }
988 
989   pcbddc->rhs_change = PETSC_FALSE;
990   /* Take into account zeroed rows -> change rhs and store solution removed */
991   if (rhs) {
992     IS dirIS = NULL;
993 
994     /* DirichletBoundariesLocal may not be consistent among neighbours; gets a dirichlet dofs IS from graph (may be cached) */
995     ierr = PCBDDCGraphGetDirichletDofs(pcbddc->mat_graph,&dirIS);CHKERRQ(ierr);
996     if (dirIS) {
997       Mat_IS            *matis = (Mat_IS*)pc->pmat->data;
998       PetscInt          dirsize,i,*is_indices;
999       PetscScalar       *array_x;
1000       const PetscScalar *array_diagonal;
1001 
1002       ierr = MatGetDiagonal(pc->pmat,pcis->vec1_global);CHKERRQ(ierr);
1003       ierr = VecPointwiseDivide(pcis->vec1_global,rhs,pcis->vec1_global);CHKERRQ(ierr);
1004       ierr = VecScatterBegin(matis->rctx,pcis->vec1_global,pcis->vec2_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1005       ierr = VecScatterEnd(matis->rctx,pcis->vec1_global,pcis->vec2_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1006       ierr = VecScatterBegin(matis->rctx,used_vec,pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1007       ierr = VecScatterEnd(matis->rctx,used_vec,pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1008       ierr = ISGetLocalSize(dirIS,&dirsize);CHKERRQ(ierr);
1009       ierr = VecGetArray(pcis->vec1_N,&array_x);CHKERRQ(ierr);
1010       ierr = VecGetArrayRead(pcis->vec2_N,&array_diagonal);CHKERRQ(ierr);
1011       ierr = ISGetIndices(dirIS,(const PetscInt**)&is_indices);CHKERRQ(ierr);
1012       for (i=0; i<dirsize; i++) array_x[is_indices[i]] = array_diagonal[is_indices[i]];
1013       ierr = ISRestoreIndices(dirIS,(const PetscInt**)&is_indices);CHKERRQ(ierr);
1014       ierr = VecRestoreArrayRead(pcis->vec2_N,&array_diagonal);CHKERRQ(ierr);
1015       ierr = VecRestoreArray(pcis->vec1_N,&array_x);CHKERRQ(ierr);
1016       ierr = VecScatterBegin(matis->rctx,pcis->vec1_N,used_vec,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1017       ierr = VecScatterEnd(matis->rctx,pcis->vec1_N,used_vec,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1018       pcbddc->rhs_change = PETSC_TRUE;
1019       ierr = ISDestroy(&dirIS);CHKERRQ(ierr);
1020     }
1021   }
1022 
1023   /* remove the computed solution or the initial guess from the rhs */
1024   if (pcbddc->rhs_change || (ksp && pcbddc->ksp_guess_nonzero) ) {
1025     /* store the original rhs */
1026     if (copy_rhs) {
1027       ierr = VecCopy(rhs,pcbddc->original_rhs);CHKERRQ(ierr);
1028       copy_rhs = PETSC_FALSE;
1029     }
1030     pcbddc->rhs_change = PETSC_TRUE;
1031     ierr = VecScale(used_vec,-1.0);CHKERRQ(ierr);
1032     ierr = MatMultAdd(pc->mat,used_vec,rhs,rhs);CHKERRQ(ierr);
1033     ierr = VecScale(used_vec,-1.0);CHKERRQ(ierr);
1034     ierr = VecCopy(used_vec,pcbddc->temp_solution);CHKERRQ(ierr);
1035     if (ksp) {
1036       ierr = KSPSetInitialGuessNonzero(ksp,PETSC_FALSE);CHKERRQ(ierr);
1037     }
1038   }
1039   ierr = VecDestroy(&used_vec);CHKERRQ(ierr);
1040 
1041   /* When using the benign trick: (TODO: what about FETI-DP?)
1042      - change rhs on pressures (iteration matrix is surely of type MATIS)
1043      - compute initial vector in benign space
1044   */
1045   if (rhs && pcbddc->benign_saddle_point) {
1046     Mat_IS *matis = (Mat_IS*)(pc->mat->data);
1047 
1048     /* store the original rhs */
1049     if (copy_rhs) {
1050       ierr = VecCopy(rhs,pcbddc->original_rhs);CHKERRQ(ierr);
1051       copy_rhs = PETSC_FALSE;
1052     }
1053 
1054     /* now change (locally) the basis */
1055     ierr = VecScatterBegin(matis->rctx,rhs,pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1056     ierr = VecScatterEnd(matis->rctx,rhs,pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1057     if (pcbddc->benign_change) {
1058       ierr = MatMultTranspose(pcbddc->benign_change,pcis->vec1_N,pcis->vec2_N);CHKERRQ(ierr);
1059       ierr = VecScatterBegin(matis->rctx,pcis->vec2_N,rhs,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1060       ierr = VecScatterEnd(matis->rctx,pcis->vec2_N,rhs,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1061       /* change local iteration matrix */
1062       ierr = MatPtAP(matis->A,pcbddc->benign_change,MAT_REUSE_MATRIX,2.0,&pcbddc->local_mat);CHKERRQ(ierr);
1063       ierr = MatDestroy(&pcbddc->benign_original_mat);CHKERRQ(ierr);
1064       ierr = PetscObjectReference((PetscObject)matis->A);CHKERRQ(ierr);
1065       pcbddc->benign_original_mat = matis->A;
1066       ierr = MatDestroy(&matis->A);CHKERRQ(ierr);
1067       ierr = PetscObjectReference((PetscObject)pcbddc->local_mat);CHKERRQ(ierr);
1068       matis->A = pcbddc->local_mat;
1069       ierr = MatDestroy(&pcbddc->local_mat);CHKERRQ(ierr);
1070     } else {
1071       ierr = VecScatterBegin(matis->rctx,pcis->vec1_N,rhs,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1072       ierr = VecScatterEnd(matis->rctx,pcis->vec1_N,rhs,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1073     }
1074     pcbddc->rhs_change = PETSC_TRUE;
1075 
1076     /* compute u^*_h as in Xuemin Tu's thesis (see Section 4.8.1) */
1077     /* TODO: what about Stokes? */
1078     if (!pcbddc->benign_vec) {
1079       ierr = VecDuplicate(rhs,&pcbddc->benign_vec);CHKERRQ(ierr);
1080     }
1081     ierr = VecSet(pcis->vec1_global,0.);CHKERRQ(ierr);
1082     pcbddc->benign_p0 = 0.;
1083     if (pcbddc->benign_p0_lidx >= 0) {
1084       const PetscScalar *array;
1085 
1086       ierr = VecGetArrayRead(pcis->vec2_N,&array);CHKERRQ(ierr);
1087       pcbddc->benign_p0 = array[pcbddc->benign_p0_lidx];
1088       ierr = VecRestoreArrayRead(pcis->vec2_N,&array);CHKERRQ(ierr);
1089     }
1090 #if 0
1091     ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] benign u* should be %1.4e\n",PetscGlobalRank,pcbddc->benign_p0);CHKERRQ(ierr);
1092 #endif
1093     ierr = PCBDDCBenignPopOrPushP0(pc,pcis->vec1_global,PETSC_FALSE);CHKERRQ(ierr);
1094     ierr = PCApply_BDDC(pc,pcis->vec1_global,pcbddc->benign_vec);CHKERRQ(ierr);
1095     pcbddc->benign_p0 = 0.;
1096     ierr = PCBDDCBenignPopOrPushP0(pc,pcbddc->benign_vec,PETSC_FALSE);CHKERRQ(ierr);
1097     if (pcbddc->benign_saddle_point) {
1098       Mat_IS* matis = (Mat_IS*)(pc->mat->data);
1099       ierr = VecScatterBegin(matis->rctx,pcbddc->benign_vec,matis->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1100       ierr = VecScatterEnd(matis->rctx,pcbddc->benign_vec,matis->x,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1101 
1102 #if 0
1103       if (pcbddc->benign_p0_lidx >=0) {
1104         Mat B0;
1105         Vec dummy_vec;
1106         PetscScalar *array;
1107         PetscInt ii[2];
1108 
1109         ii[0] = 0;
1110         ii[1] = pcbddc->B0_ncol;
1111         ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,1,pcis->n,ii,pcbddc->B0_cols,pcbddc->B0_vals,&B0);CHKERRQ(ierr);
1112         ierr = MatCreateVecs(B0,NULL,&dummy_vec);CHKERRQ(ierr);
1113         ierr = MatMult(B0,matis->x,dummy_vec);CHKERRQ(ierr);
1114         ierr = VecGetArray(dummy_vec,&array);CHKERRQ(ierr);
1115         ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] benign u* is %1.4e\n",PetscGlobalRank,array[0]);CHKERRQ(ierr);
1116         ierr = VecRestoreArray(dummy_vec,&array);CHKERRQ(ierr);
1117         ierr = MatDestroy(&B0);CHKERRQ(ierr);
1118         ierr = VecDestroy(&dummy_vec);CHKERRQ(ierr);
1119       }
1120 #endif
1121     }
1122   }
1123 
1124   /* change rhs and iteration matrix if using the change of basis */
1125   if (pcbddc->ChangeOfBasisMatrix) {
1126     PCBDDCChange_ctx change_ctx;
1127 
1128     /* get change ctx */
1129     ierr = MatShellGetContext(pcbddc->new_global_mat,&change_ctx);CHKERRQ(ierr);
1130 
1131     /* set current iteration matrix inside change context (change of basis has been already set into the ctx during PCSetUp) */
1132     ierr = MatDestroy(&change_ctx->original_mat);CHKERRQ(ierr);
1133     ierr = PetscObjectReference((PetscObject)pc->mat);CHKERRQ(ierr);
1134     change_ctx->original_mat = pc->mat;
1135 
1136     /* change iteration matrix */
1137     ierr = MatDestroy(&pc->mat);CHKERRQ(ierr);
1138     ierr = PetscObjectReference((PetscObject)pcbddc->new_global_mat);CHKERRQ(ierr);
1139     pc->mat = pcbddc->new_global_mat;
1140 
1141     /* store the original rhs */
1142     if (copy_rhs) {
1143       ierr = VecCopy(rhs,pcbddc->original_rhs);CHKERRQ(ierr);
1144       copy_rhs = PETSC_FALSE;
1145     }
1146 
1147     /* change rhs */
1148     ierr = MatMultTranspose(change_ctx->global_change,rhs,pcis->vec1_global);CHKERRQ(ierr);
1149     ierr = VecCopy(pcis->vec1_global,rhs);CHKERRQ(ierr);
1150     pcbddc->rhs_change = PETSC_TRUE;
1151   }
1152 
1153   /* remove non-benign solution from the rhs */
1154   if (pcbddc->benign_saddle_point) {
1155     /* store the original rhs */
1156     if (copy_rhs) {
1157       ierr = VecCopy(rhs,pcbddc->original_rhs);CHKERRQ(ierr);
1158       copy_rhs = PETSC_FALSE;
1159     }
1160     ierr = VecScale(pcbddc->benign_vec,-1.0);CHKERRQ(ierr);
1161     ierr = MatMultAdd(pc->mat,pcbddc->benign_vec,rhs,rhs);CHKERRQ(ierr);
1162     pcbddc->rhs_change = PETSC_TRUE;
1163   }
1164 
1165   /* set initial guess if using PCG */
1166   if (x && pcbddc->use_exact_dirichlet_trick) {
1167     ierr = VecSet(x,0.0);CHKERRQ(ierr);
1168     ierr = VecScatterBegin(pcis->global_to_D,rhs,pcis->vec1_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1169     ierr = VecScatterEnd(pcis->global_to_D,rhs,pcis->vec1_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1170     ierr = KSPSolve(pcbddc->ksp_D,pcis->vec1_D,pcis->vec2_D);CHKERRQ(ierr);
1171     ierr = VecScatterBegin(pcis->global_to_D,pcis->vec2_D,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1172     ierr = VecScatterEnd(pcis->global_to_D,pcis->vec2_D,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1173     if (ksp) {
1174       ierr = KSPSetInitialGuessNonzero(ksp,PETSC_TRUE);CHKERRQ(ierr);
1175     }
1176   }
1177 
1178   /* remove nullspace if present */
1179   if (ksp && x && pcbddc->NullSpace) {
1180     ierr = MatNullSpaceRemove(pcbddc->NullSpace,x);CHKERRQ(ierr);
1181     /* store the original rhs */
1182     if (copy_rhs) {
1183       ierr = VecCopy(rhs,pcbddc->original_rhs);CHKERRQ(ierr);
1184       copy_rhs = PETSC_FALSE;
1185     }
1186     pcbddc->rhs_change = PETSC_TRUE;
1187     ierr = MatNullSpaceRemove(pcbddc->NullSpace,rhs);CHKERRQ(ierr);
1188   }
1189   PetscFunctionReturn(0);
1190 }
1191 
1192 /* -------------------------------------------------------------------------- */
1193 #undef __FUNCT__
1194 #define __FUNCT__ "PCPostSolve_BDDC"
1195 /* -------------------------------------------------------------------------- */
1196 /*
1197    PCPostSolve_BDDC - Changes the computed solution if a transformation of basis
1198                      approach has been selected. Also, restores rhs to its original state.
1199 
1200    Input Parameter:
1201 +  pc - the preconditioner contex
1202 
1203    Application Interface Routine: PCPostSolve()
1204 
1205    Notes:
1206      The interface routine PCPostSolve() is not usually called directly by
1207      the user, but instead is called by KSPSolve().
1208 */
1209 static PetscErrorCode PCPostSolve_BDDC(PC pc, KSP ksp, Vec rhs, Vec x)
1210 {
1211   PetscErrorCode ierr;
1212   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
1213 
1214   PetscFunctionBegin;
1215   if (pcbddc->ChangeOfBasisMatrix) {
1216     PCBDDCChange_ctx change_ctx;
1217 
1218     /* get change ctx */
1219     ierr = MatShellGetContext(pcbddc->new_global_mat,&change_ctx);CHKERRQ(ierr);
1220 
1221     /* restore iteration matrix */
1222     ierr = MatDestroy(&pc->mat);CHKERRQ(ierr);
1223     ierr = PetscObjectReference((PetscObject)change_ctx->original_mat);CHKERRQ(ierr);
1224     pc->mat = change_ctx->original_mat;
1225 
1226     /* need to restore the local matrices */
1227     if (pcbddc->benign_saddle_point && pcbddc->benign_change) {
1228       Mat_IS *matis = (Mat_IS*)pc->mat->data;
1229 
1230       ierr = MatDestroy(&matis->A);CHKERRQ(ierr);
1231       ierr = PetscObjectReference((PetscObject)pcbddc->benign_original_mat);CHKERRQ(ierr);
1232       matis->A = pcbddc->benign_original_mat;
1233       ierr = MatDestroy(&pcbddc->benign_original_mat);CHKERRQ(ierr);
1234     }
1235 
1236     /* get solution in original basis */
1237     if (x) {
1238       PC_IS *pcis = (PC_IS*)(pc->data);
1239 
1240 
1241       /* restore solution on pressures */
1242       if (pcbddc->benign_saddle_point) {
1243         Mat_IS *matis = (Mat_IS*)pc->mat->data;
1244 
1245         /* add non-benign solution */
1246         ierr = VecAXPY(x,-1.0,pcbddc->benign_vec);CHKERRQ(ierr);
1247 
1248         /* change basis on pressures for x */
1249         ierr = VecScatterBegin(matis->rctx,x,pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1250         ierr = VecScatterEnd(matis->rctx,x,pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1251         if (pcbddc->benign_change) {
1252 
1253           ierr = MatMult(pcbddc->benign_change,pcis->vec1_N,pcis->vec2_N);CHKERRQ(ierr);
1254           ierr = VecScatterBegin(matis->rctx,pcis->vec2_N,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1255           ierr = VecScatterEnd(matis->rctx,pcis->vec2_N,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1256         } else {
1257           ierr = VecScatterBegin(matis->rctx,pcis->vec1_N,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1258           ierr = VecScatterEnd(matis->rctx,pcis->vec1_N,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1259         }
1260       }
1261       /* change basis on x */
1262       ierr = MatMult(change_ctx->global_change,x,pcis->vec1_global);CHKERRQ(ierr);
1263       ierr = VecCopy(pcis->vec1_global,x);CHKERRQ(ierr);
1264     }
1265   }
1266 
1267   /* add solution removed in presolve */
1268   if (x && pcbddc->rhs_change) {
1269     ierr = VecAXPY(x,1.0,pcbddc->temp_solution);CHKERRQ(ierr);
1270   }
1271 
1272   /* restore rhs to its original state */
1273   if (rhs && pcbddc->rhs_change) {
1274     ierr = VecCopy(pcbddc->original_rhs,rhs);CHKERRQ(ierr);
1275   }
1276   pcbddc->rhs_change = PETSC_FALSE;
1277 
1278   /* restore ksp guess state */
1279   if (ksp) {
1280     ierr = KSPSetInitialGuessNonzero(ksp,pcbddc->ksp_guess_nonzero);CHKERRQ(ierr);
1281   }
1282   PetscFunctionReturn(0);
1283 }
1284 /* -------------------------------------------------------------------------- */
1285 #undef __FUNCT__
1286 #define __FUNCT__ "PCSetUp_BDDC"
1287 /* -------------------------------------------------------------------------- */
1288 /*
1289    PCSetUp_BDDC - Prepares for the use of the BDDC preconditioner
1290                   by setting data structures and options.
1291 
1292    Input Parameter:
1293 +  pc - the preconditioner context
1294 
1295    Application Interface Routine: PCSetUp()
1296 
1297    Notes:
1298      The interface routine PCSetUp() is not usually called directly by
1299      the user, but instead is called by PCApply() if necessary.
1300 */
1301 PetscErrorCode PCSetUp_BDDC(PC pc)
1302 {
1303   PetscErrorCode ierr;
1304   PC_BDDC*       pcbddc = (PC_BDDC*)pc->data;
1305   Mat_IS*        matis;
1306   MatNullSpace   nearnullspace;
1307   IS             zerodiag = NULL;
1308   PetscInt       nrows,ncols;
1309   PetscBool      computetopography,computesolvers,computesubschurs;
1310   PetscBool      computeconstraintsmatrix;
1311   PetscBool      new_nearnullspace_provided,ismatis;
1312 
1313   PetscFunctionBegin;
1314   ierr = PetscObjectTypeCompare((PetscObject)pc->pmat,MATIS,&ismatis);CHKERRQ(ierr);
1315   if (!ismatis) {
1316     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONG,"PCBDDC preconditioner requires matrix of type MATIS");
1317   }
1318   ierr = MatGetSize(pc->pmat,&nrows,&ncols);CHKERRQ(ierr);
1319   if (nrows != ncols) {
1320     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"PCBDDC preconditioner requires a square preconditioning matrix");
1321   }
1322   matis = (Mat_IS*)pc->pmat->data;
1323   /* the following lines of code should be replaced by a better logic between PCIS, PCNN, PCBDDC and other future nonoverlapping preconditioners */
1324   /* For BDDC we need to define a local "Neumann" problem different to that defined in PCISSetup
1325      Also, BDDC directly build the Dirichlet problem */
1326   /* split work */
1327   if (pc->setupcalled) {
1328     if (pc->flag == SAME_NONZERO_PATTERN) {
1329       computetopography = PETSC_FALSE;
1330       computesolvers = PETSC_TRUE;
1331     } else { /* DIFFERENT_NONZERO_PATTERN */
1332       computetopography = PETSC_TRUE;
1333       computesolvers = PETSC_TRUE;
1334     }
1335   } else {
1336     computetopography = PETSC_TRUE;
1337     computesolvers = PETSC_TRUE;
1338   }
1339   if (pcbddc->recompute_topography) {
1340     computetopography = PETSC_TRUE;
1341   }
1342   computeconstraintsmatrix = PETSC_FALSE;
1343   if (pcbddc->adaptive_threshold > 0.0 && !pcbddc->use_deluxe_scaling) {
1344     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot compute adaptive constraints without deluxe scaling. Rerun with -pc_bddc_use_deluxe_scaling");
1345   }
1346   pcbddc->adaptive_selection = (PetscBool)(pcbddc->adaptive_threshold > 0.0 && pcbddc->use_deluxe_scaling);
1347   if (pcbddc->adaptive_selection) pcbddc->use_faces = PETSC_TRUE;
1348 
1349   computesubschurs = (PetscBool)(pcbddc->adaptive_selection || pcbddc->use_deluxe_scaling);
1350   if (pcbddc->faster_deluxe && pcbddc->adaptive_selection && pcbddc->use_change_of_basis) {
1351     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot compute faster deluxe if adaptivity and change of basis are both requested. Rerun with -pc_bddc_deluxe_faster false");
1352   }
1353 
1354   /* check if the iteration matrix is of type MATIS in case the benign trick has been requested */
1355   ierr = PetscObjectTypeCompare((PetscObject)pc->mat,MATIS,&ismatis);CHKERRQ(ierr);
1356   if (pcbddc->benign_saddle_point && !ismatis) {
1357     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONG,"PCBDDC preconditioner with benign subspace trick requires the iteration matrix to be of type MATIS");
1358   }
1359 
1360   /* raise error if the user has provided the change of basis and the benign trick has been requested */
1361   if (pcbddc->benign_saddle_point && pcbddc->user_ChangeOfBasisMatrix) {
1362     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot apply the benign trick with a user defined change of basis");
1363   }
1364 
1365   /* Get stdout for dbg */
1366   if (pcbddc->dbg_flag) {
1367     if (!pcbddc->dbg_viewer) {
1368       pcbddc->dbg_viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)pc));
1369       ierr = PetscViewerASCIISynchronizedAllow(pcbddc->dbg_viewer,PETSC_TRUE);CHKERRQ(ierr);
1370     }
1371     ierr = PetscViewerASCIIAddTab(pcbddc->dbg_viewer,2*pcbddc->current_level);CHKERRQ(ierr);
1372   }
1373 
1374   if (pcbddc->user_ChangeOfBasisMatrix) {
1375     /* use_change_of_basis flag is used to automatically compute a change of basis from constraints */
1376     pcbddc->use_change_of_basis = PETSC_FALSE;
1377     ierr = PCBDDCComputeLocalMatrix(pc,pcbddc->user_ChangeOfBasisMatrix);CHKERRQ(ierr);
1378   } else {
1379     ierr = MatDestroy(&pcbddc->local_mat);CHKERRQ(ierr);
1380     if (!pcbddc->benign_saddle_point) {
1381       ierr = PetscObjectReference((PetscObject)matis->A);CHKERRQ(ierr);
1382       pcbddc->local_mat = matis->A;
1383     } else {
1384       PetscInt  nz;
1385       PetscBool sorted;
1386 
1387       ierr = MatFindZeroDiagonals(matis->A,&zerodiag);CHKERRQ(ierr);
1388       ierr = ISSorted(zerodiag,&sorted);CHKERRQ(ierr);
1389       if (!sorted) {
1390         ierr = ISSort(zerodiag);CHKERRQ(ierr);
1391       }
1392       ierr = ISGetLocalSize(zerodiag,&nz);CHKERRQ(ierr);
1393       if (nz) {
1394         IS                zerodiagc;
1395         PetscScalar       *array;
1396         const PetscInt    *idxs,*idxsc;
1397         PetscInt          i,n,*nnz;
1398 
1399         /* TODO: add check for shared dofs */
1400         pcbddc->use_change_of_basis = PETSC_TRUE;
1401         pcbddc->use_change_on_faces = PETSC_TRUE;
1402         ierr = MatGetLocalSize(matis->A,&n,NULL);CHKERRQ(ierr);
1403         ierr = ISComplement(zerodiag,0,n,&zerodiagc);CHKERRQ(ierr);
1404         ierr = ISGetIndices(zerodiag,&idxs);CHKERRQ(ierr);
1405         ierr = ISGetIndices(zerodiagc,&idxsc);CHKERRQ(ierr);
1406         /* local change of basis for pressures */
1407         ierr = MatDestroy(&pcbddc->benign_change);CHKERRQ(ierr);
1408         ierr = MatCreate(PetscObjectComm((PetscObject)matis->A),&pcbddc->benign_change);CHKERRQ(ierr);
1409         ierr = MatSetType(pcbddc->benign_change,MATAIJ);CHKERRQ(ierr);
1410         ierr = MatSetSizes(pcbddc->benign_change,n,n,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
1411         ierr = PetscMalloc1(n,&nnz);CHKERRQ(ierr);
1412         for (i=0;i<n-nz;i++) nnz[idxsc[i]] = 1; /* identity on velocities */
1413         for (i=0;i<nz-1;i++) nnz[idxs[i]] = 2; /* change on pressures */
1414         nnz[idxs[nz-1]] = nz; /* last local pressure dof: _0 set */
1415         ierr = MatSeqAIJSetPreallocation(pcbddc->benign_change,0,nnz);CHKERRQ(ierr);
1416         ierr = PetscFree(nnz);CHKERRQ(ierr);
1417         /* set identity on velocities */
1418         for (i=0;i<n-nz;i++) {
1419           ierr = MatSetValue(pcbddc->benign_change,idxsc[i],idxsc[i],1.,INSERT_VALUES);CHKERRQ(ierr);
1420         }
1421         /* set change on pressures */
1422         for (i=0;i<nz-1;i++) {
1423           PetscScalar vals[2];
1424           PetscInt    cols[2];
1425 
1426           /* TODO: add quadrature */
1427           cols[0] = idxs[i];
1428           cols[1] = idxs[nz-1];
1429           vals[0] = 1.;
1430           vals[1] = 1./nz;
1431           ierr = MatSetValues(pcbddc->benign_change,1,idxs+i,2,cols,vals,INSERT_VALUES);CHKERRQ(ierr);
1432         }
1433         ierr = PetscMalloc1(nz,&array);CHKERRQ(ierr);
1434         for (i=0;i<nz-1;i++) array[i] = -1.;
1435         array[nz-1] = 1./nz;
1436         ierr = MatSetValues(pcbddc->benign_change,1,idxs+nz-1,nz,idxs,array,INSERT_VALUES);CHKERRQ(ierr);
1437         ierr = PetscFree(array);CHKERRQ(ierr);
1438         ierr = MatAssemblyBegin(pcbddc->benign_change,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1439         ierr = MatAssemblyEnd(pcbddc->benign_change,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1440         /* TODO: need optimization? */
1441         ierr = MatPtAP(matis->A,pcbddc->benign_change,MAT_INITIAL_MATRIX,2.0,&pcbddc->local_mat);CHKERRQ(ierr);
1442         /* store local and global idxs for p0 */
1443         pcbddc->benign_p0_lidx = idxs[nz-1];
1444         ierr = ISLocalToGlobalMappingApply(pc->pmat->rmap->mapping,1,&idxs[nz-1],&pcbddc->benign_p0_gidx);CHKERRQ(ierr);
1445         ierr = ISRestoreIndices(zerodiag,&idxs);CHKERRQ(ierr);
1446         ierr = ISRestoreIndices(zerodiagc,&idxsc);CHKERRQ(ierr);
1447         ierr = ISDestroy(&zerodiagc);CHKERRQ(ierr);
1448         /* pop B0 mat from pcbddc->local_mat */
1449         ierr = PCBDDCBenignPopOrPushB0(pc,PETSC_TRUE);CHKERRQ(ierr);
1450       } else { /* this is unlikely to happen but, just in case, destroy the empty IS */
1451         ierr = ISDestroy(&zerodiag);CHKERRQ(ierr);
1452         ierr = PetscObjectReference((PetscObject)matis->A);CHKERRQ(ierr);
1453         pcbddc->local_mat = matis->A;
1454       }
1455     }
1456   }
1457 
1458   /* workaround for reals */
1459 #if !defined(PETSC_USE_COMPLEX)
1460   if (matis->A->symmetric_set) {
1461     ierr = MatSetOption(pcbddc->local_mat,MAT_HERMITIAN,matis->A->symmetric);CHKERRQ(ierr);
1462   }
1463 #endif
1464   if (matis->A->symmetric_set) {
1465     ierr = MatSetOption(pcbddc->local_mat,MAT_SYMMETRIC,matis->A->symmetric);CHKERRQ(ierr);
1466   }
1467   if (matis->A->spd_set) {
1468     ierr = MatSetOption(pcbddc->local_mat,MAT_SPD,matis->A->spd);CHKERRQ(ierr);
1469   }
1470 
1471   /* Set up all the "iterative substructuring" common block without computing solvers */
1472   {
1473     Mat temp_mat;
1474 
1475     temp_mat = matis->A;
1476     matis->A = pcbddc->local_mat;
1477     ierr = PCISSetUp(pc,PETSC_FALSE);CHKERRQ(ierr);
1478     pcbddc->local_mat = matis->A;
1479     matis->A = temp_mat;
1480   }
1481 
1482   /* Analyze interface */
1483   if (computetopography) {
1484     ierr = PCBDDCAnalyzeInterface(pc);CHKERRQ(ierr);
1485     computeconstraintsmatrix = PETSC_TRUE;
1486   }
1487 
1488   /* check b(v_I,p_0) = 0 for all v_I */
1489   if (pcbddc->dbg_flag && zerodiag) {
1490     PC_IS          *pcis = (PC_IS*)(pc->data);
1491     IS             dirIS = NULL;
1492     PetscScalar    *vals;
1493     const PetscInt *idxs;
1494     PetscInt       i,nz;
1495 
1496     /* p0 */
1497     ierr = VecSet(pcis->vec1_N,0.);CHKERRQ(ierr);
1498     ierr = PetscMalloc1(pcis->n,&vals);CHKERRQ(ierr);
1499     ierr = ISGetLocalSize(zerodiag,&nz);CHKERRQ(ierr);
1500     ierr = ISGetIndices(zerodiag,&idxs);CHKERRQ(ierr);
1501     for (i=0;i<nz;i++) vals[i] = 1.;
1502     ierr = VecSetValues(pcis->vec1_N,nz,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1503     ierr = VecAssemblyBegin(pcis->vec1_N);CHKERRQ(ierr);
1504     ierr = VecAssemblyEnd(pcis->vec1_N);CHKERRQ(ierr);
1505     /* v_I */
1506     ierr = VecSetRandom(pcis->vec2_N,NULL);CHKERRQ(ierr);
1507     for (i=0;i<nz;i++) vals[i] = 0.;
1508     ierr = VecSetValues(pcis->vec2_N,nz,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1509     ierr = ISRestoreIndices(zerodiag,&idxs);CHKERRQ(ierr);
1510     ierr = ISGetIndices(pcis->is_B_local,&idxs);CHKERRQ(ierr);
1511     for (i=0;i<pcis->n_B;i++) vals[i] = 0.;
1512     ierr = VecSetValues(pcis->vec2_N,pcis->n_B,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1513     ierr = ISRestoreIndices(pcis->is_B_local,&idxs);CHKERRQ(ierr);
1514     ierr = PCBDDCGraphGetDirichletDofs(pcbddc->mat_graph,&dirIS);CHKERRQ(ierr);
1515     if (dirIS) {
1516       PetscInt n;
1517 
1518       ierr = ISGetLocalSize(dirIS,&n);CHKERRQ(ierr);
1519       ierr = ISGetIndices(dirIS,&idxs);CHKERRQ(ierr);
1520       for (i=0;i<n;i++) vals[i] = 0.;
1521       ierr = VecSetValues(pcis->vec2_N,n,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1522       ierr = ISRestoreIndices(dirIS,&idxs);CHKERRQ(ierr);
1523     }
1524     ierr = ISDestroy(&dirIS);CHKERRQ(ierr);
1525     ierr = VecAssemblyBegin(pcis->vec2_N);CHKERRQ(ierr);
1526     ierr = VecAssemblyEnd(pcis->vec2_N);CHKERRQ(ierr);
1527     ierr = VecSet(matis->x,0.);CHKERRQ(ierr);
1528     ierr = MatMult(matis->A,pcis->vec1_N,matis->x);CHKERRQ(ierr);
1529     ierr = VecDot(matis->x,pcis->vec2_N,&vals[0]);CHKERRQ(ierr);
1530     ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] check original mat: %1.4e\n",PetscGlobalRank,vals[0]);CHKERRQ(ierr);
1531     ierr = PetscFree(vals);CHKERRQ(ierr);
1532   }
1533 
1534   /* check PCBDDCBenignPopOrPush */
1535   if (pcbddc->dbg_flag && pcbddc->benign_saddle_point) {
1536     PC_IS  *pcis = (PC_IS*)(pc->data);
1537 
1538     ierr = VecSetRandom(pcis->vec1_global,NULL);CHKERRQ(ierr);
1539     pcbddc->benign_p0 = -PetscGlobalRank;
1540     ierr = PCBDDCBenignPopOrPushP0(pc,pcis->vec1_global,PETSC_FALSE);CHKERRQ(ierr);
1541     pcbddc->benign_p0 = 1;
1542     ierr = PCBDDCBenignPopOrPushP0(pc,pcis->vec1_global,PETSC_TRUE);CHKERRQ(ierr);
1543     if (pcbddc->benign_p0_gidx >=0 && pcbddc->benign_p0 != -PetscGlobalRank) {
1544       SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Error testing PCBDDCBenignPopOrPushP0! Found %1.4e instead of %1.4e\n",pcbddc->benign_p0,-PetscGlobalRank);CHKERRQ(ierr);
1545     }
1546   }
1547 
1548   /* Setup local dirichlet solver ksp_D and sub_schurs solvers */
1549   if (computesolvers) {
1550     PCBDDCSubSchurs sub_schurs=pcbddc->sub_schurs;
1551 
1552     if (computesubschurs && computetopography) {
1553       ierr = PCBDDCInitSubSchurs(pc);CHKERRQ(ierr);
1554     }
1555     if (sub_schurs->use_mumps) {
1556       if (computesubschurs) {
1557         ierr = PCBDDCSetUpSubSchurs(pc);CHKERRQ(ierr);
1558       }
1559       ierr = PCBDDCSetUpLocalSolvers(pc,PETSC_TRUE,PETSC_FALSE);CHKERRQ(ierr);
1560     } else {
1561       ierr = PCBDDCSetUpLocalSolvers(pc,PETSC_TRUE,PETSC_FALSE);CHKERRQ(ierr);
1562       if (computesubschurs) {
1563         ierr = PCBDDCSetUpSubSchurs(pc);CHKERRQ(ierr);
1564       }
1565     }
1566     if (pcbddc->adaptive_selection) {
1567       ierr = PCBDDCAdaptiveSelection(pc);CHKERRQ(ierr);
1568       computeconstraintsmatrix = PETSC_TRUE;
1569     }
1570   }
1571 
1572   /* infer if NullSpace object attached to Mat via MatSetNearNullSpace has changed */
1573   new_nearnullspace_provided = PETSC_FALSE;
1574   ierr = MatGetNearNullSpace(pc->pmat,&nearnullspace);CHKERRQ(ierr);
1575   if (pcbddc->onearnullspace) { /* already used nearnullspace */
1576     if (!nearnullspace) { /* near null space attached to mat has been destroyed */
1577       new_nearnullspace_provided = PETSC_TRUE;
1578     } else {
1579       /* determine if the two nullspaces are different (should be lightweight) */
1580       if (nearnullspace != pcbddc->onearnullspace) {
1581         new_nearnullspace_provided = PETSC_TRUE;
1582       } else { /* maybe the user has changed the content of the nearnullspace so check vectors ObjectStateId */
1583         PetscInt         i;
1584         const Vec        *nearnullvecs;
1585         PetscObjectState state;
1586         PetscInt         nnsp_size;
1587         ierr = MatNullSpaceGetVecs(nearnullspace,NULL,&nnsp_size,&nearnullvecs);CHKERRQ(ierr);
1588         for (i=0;i<nnsp_size;i++) {
1589           ierr = PetscObjectStateGet((PetscObject)nearnullvecs[i],&state);CHKERRQ(ierr);
1590           if (pcbddc->onearnullvecs_state[i] != state) {
1591             new_nearnullspace_provided = PETSC_TRUE;
1592             break;
1593           }
1594         }
1595       }
1596     }
1597   } else {
1598     if (!nearnullspace) { /* both nearnullspaces are null */
1599       new_nearnullspace_provided = PETSC_FALSE;
1600     } else { /* nearnullspace attached later */
1601       new_nearnullspace_provided = PETSC_TRUE;
1602     }
1603   }
1604 
1605   /* Setup constraints and related work vectors */
1606   /* reset primal space flags */
1607   pcbddc->new_primal_space = PETSC_FALSE;
1608   pcbddc->new_primal_space_local = PETSC_FALSE;
1609   if (computeconstraintsmatrix || new_nearnullspace_provided) {
1610     /* It also sets the primal space flags */
1611     ierr = PCBDDCConstraintsSetUp(pc);CHKERRQ(ierr);
1612     /* Allocate needed local vectors (which depends on quantities defined during ConstraintsSetUp) */
1613     ierr = PCBDDCSetUpLocalWorkVectors(pc);CHKERRQ(ierr);
1614   }
1615 
1616   if (computesolvers || pcbddc->new_primal_space) {
1617     if (pcbddc->use_change_of_basis) {
1618       PC_IS *pcis = (PC_IS*)(pc->data);
1619       Mat   temp_mat = NULL;
1620 
1621       if (zerodiag) {
1622         /* insert B0 in pcbddc->local_mat */
1623         ierr = PCBDDCBenignPopOrPushB0(pc,PETSC_FALSE);CHKERRQ(ierr);
1624         if (pcbddc->dbg_flag) {
1625           PC_IS          *pcis = (PC_IS*)(pc->data);
1626           IS             dirIS = NULL;
1627           PetscScalar    *vals;
1628           const PetscInt *idxs;
1629           PetscInt       i,nz;
1630 
1631           /* p0 */
1632           ierr = VecSet(pcis->vec1_N,0.);CHKERRQ(ierr);
1633           ierr = PetscMalloc1(pcis->n,&vals);CHKERRQ(ierr);
1634           ierr = ISGetLocalSize(zerodiag,&nz);CHKERRQ(ierr);
1635           ierr = ISGetIndices(zerodiag,&idxs);CHKERRQ(ierr);
1636           vals[0] = 1.;
1637           ierr = VecSetValues(pcis->vec1_N,1,&idxs[nz-1],vals,INSERT_VALUES);CHKERRQ(ierr);
1638           ierr = VecAssemblyBegin(pcis->vec1_N);CHKERRQ(ierr);
1639           ierr = VecAssemblyEnd(pcis->vec1_N);CHKERRQ(ierr);
1640           /* v_I */
1641           ierr = VecSetRandom(pcis->vec2_N,NULL);CHKERRQ(ierr);
1642           for (i=0;i<nz;i++) vals[i] = 0.;
1643           ierr = VecSetValues(pcis->vec2_N,nz,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1644           ierr = ISRestoreIndices(zerodiag,&idxs);CHKERRQ(ierr);
1645           ierr = ISGetIndices(pcis->is_B_local,&idxs);CHKERRQ(ierr);
1646           for (i=0;i<pcis->n_B;i++) vals[i] = 0.;
1647           ierr = VecSetValues(pcis->vec2_N,pcis->n_B,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1648           ierr = ISRestoreIndices(pcis->is_B_local,&idxs);CHKERRQ(ierr);
1649           ierr = PCBDDCGraphGetDirichletDofs(pcbddc->mat_graph,&dirIS);CHKERRQ(ierr);
1650           if (dirIS) {
1651             PetscInt n;
1652 
1653             ierr = ISGetLocalSize(dirIS,&n);CHKERRQ(ierr);
1654             ierr = ISGetIndices(dirIS,&idxs);CHKERRQ(ierr);
1655             for (i=0;i<n;i++) vals[i] = 0.;
1656             ierr = VecSetValues(pcis->vec2_N,n,idxs,vals,INSERT_VALUES);CHKERRQ(ierr);
1657             ierr = ISRestoreIndices(dirIS,&idxs);CHKERRQ(ierr);
1658           }
1659           ierr = ISDestroy(&dirIS);CHKERRQ(ierr);
1660           ierr = VecAssemblyBegin(pcis->vec2_N);CHKERRQ(ierr);
1661           ierr = VecAssemblyEnd(pcis->vec2_N);CHKERRQ(ierr);
1662           ierr = VecSet(matis->x,0.);CHKERRQ(ierr);
1663           ierr = MatMult(pcbddc->local_mat,pcis->vec1_N,matis->x);CHKERRQ(ierr);
1664           ierr = VecDot(matis->x,pcis->vec2_N,&vals[0]);CHKERRQ(ierr);
1665           ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] check new mat: %1.4e\n",PetscGlobalRank,vals[0]);CHKERRQ(ierr);
1666           ierr = PetscFree(vals);CHKERRQ(ierr);
1667         }
1668         /* hack: swap pointers */
1669         temp_mat = matis->A;
1670         matis->A = pcbddc->local_mat;
1671         pcbddc->local_mat = NULL;
1672       }
1673       ierr = PCBDDCComputeLocalMatrix(pc,pcbddc->ChangeOfBasisMatrix);CHKERRQ(ierr);
1674       if (zerodiag) {
1675         /* restore original matrix */
1676         ierr = MatDestroy(&matis->A);CHKERRQ(ierr);
1677         matis->A = temp_mat;
1678         /* pop B0 from pcbddc->local_mat */
1679         ierr = PCBDDCBenignPopOrPushB0(pc,PETSC_TRUE);CHKERRQ(ierr);
1680       }
1681       /* get submatrices */
1682       ierr = MatDestroy(&pcis->A_IB);CHKERRQ(ierr);
1683       ierr = MatDestroy(&pcis->A_BI);CHKERRQ(ierr);
1684       ierr = MatDestroy(&pcis->A_BB);CHKERRQ(ierr);
1685       ierr = MatGetSubMatrix(pcbddc->local_mat,pcis->is_B_local,pcis->is_B_local,MAT_INITIAL_MATRIX,&pcis->A_BB);CHKERRQ(ierr);
1686       ierr = MatGetSubMatrix(pcbddc->local_mat,pcis->is_I_local,pcis->is_B_local,MAT_INITIAL_MATRIX,&pcis->A_IB);CHKERRQ(ierr);
1687       ierr = MatGetSubMatrix(pcbddc->local_mat,pcis->is_B_local,pcis->is_I_local,MAT_INITIAL_MATRIX,&pcis->A_BI);CHKERRQ(ierr);
1688       /* set flag in pcis to not reuse submatrices during PCISCreate */
1689       pcis->reusesubmatrices = PETSC_FALSE;
1690     } else if (!pcbddc->user_ChangeOfBasisMatrix) {
1691       ierr = MatDestroy(&pcbddc->local_mat);CHKERRQ(ierr);
1692       ierr = PetscObjectReference((PetscObject)matis->A);CHKERRQ(ierr);
1693       pcbddc->local_mat = matis->A;
1694     }
1695     /* SetUp coarse and local Neumann solvers */
1696     ierr = PCBDDCSetUpSolvers(pc);CHKERRQ(ierr);
1697     /* SetUp Scaling operator */
1698     ierr = PCBDDCScalingSetUp(pc);CHKERRQ(ierr);
1699   }
1700 
1701   /* check BDDC operator */
1702   if (pcbddc->dbg_flag && (
1703       (pcbddc->n_vertices == pcbddc->local_primal_size) || pcbddc->benign_saddle_point) ) {
1704     PC_IS          *pcis = (PC_IS*)(pc->data);
1705     Mat            S_j,B0=NULL,B0_B=NULL;
1706     Vec            dummy_vec=NULL,vec_check_B,vec_scale_P;
1707     PetscScalar    norm,p0_check,*array,*array2;
1708     PetscInt       i;
1709 
1710     /* B0 and B0_B */
1711     if (zerodiag) {
1712       IS       dummy;
1713       PetscInt ii[2];
1714 
1715       ii[0] = 0;
1716       ii[1] = pcbddc->B0_ncol;
1717       ierr = MatCreateSeqAIJWithArrays(PETSC_COMM_SELF,1,pcis->n,ii,pcbddc->B0_cols,pcbddc->B0_vals,&B0);CHKERRQ(ierr);
1718       ierr = ISCreateStride(PETSC_COMM_SELF,1,0,1,&dummy);CHKERRQ(ierr);
1719       ierr = MatGetSubMatrix(B0,dummy,pcis->is_B_local,MAT_INITIAL_MATRIX,&B0_B);CHKERRQ(ierr);
1720       ierr = MatCreateVecs(B0_B,NULL,&dummy_vec);CHKERRQ(ierr);
1721       ierr = ISDestroy(&dummy);CHKERRQ(ierr);
1722     }
1723     /* I need a primal vector to scale primal nodes since BDDC sums contibutions */
1724     ierr = VecDuplicate(pcbddc->vec1_P,&vec_scale_P);CHKERRQ(ierr);
1725     ierr = VecSet(pcbddc->vec1_P,1.0);CHKERRQ(ierr);
1726     ierr = VecScatterBegin(pcbddc->coarse_loc_to_glob,pcbddc->vec1_P,pcbddc->coarse_vec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1727     ierr = VecScatterEnd(pcbddc->coarse_loc_to_glob,pcbddc->vec1_P,pcbddc->coarse_vec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1728     ierr = VecScatterBegin(pcbddc->coarse_loc_to_glob,pcbddc->coarse_vec,vec_scale_P,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1729     ierr = VecScatterEnd(pcbddc->coarse_loc_to_glob,pcbddc->coarse_vec,vec_scale_P,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1730     ierr = VecReciprocal(vec_scale_P);CHKERRQ(ierr);
1731     /* S_j */
1732     ierr = MatCreateSchurComplement(pcis->A_II,pcis->A_II,pcis->A_IB,pcis->A_BI,pcis->A_BB,&S_j);CHKERRQ(ierr);
1733     ierr = MatSchurComplementSetKSP(S_j,pcbddc->ksp_D);CHKERRQ(ierr);
1734 
1735     /* mimic vector in \widetilde{W}_\Gamma */
1736     ierr = VecSetRandom(pcis->vec1_N,NULL);CHKERRQ(ierr);
1737     /* continuous in primal space */
1738     ierr = VecSetRandom(pcbddc->coarse_vec,NULL);CHKERRQ(ierr);
1739     ierr = VecScatterBegin(pcbddc->coarse_loc_to_glob,pcbddc->coarse_vec,pcbddc->vec1_P,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1740     ierr = VecScatterEnd(pcbddc->coarse_loc_to_glob,pcbddc->coarse_vec,pcbddc->vec1_P,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1741     ierr = VecGetArray(pcbddc->vec1_P,&array);CHKERRQ(ierr);
1742     if (zerodiag) {
1743       p0_check = array[pcbddc->local_primal_size-1];
1744     } else {
1745       p0_check = 0;
1746     }
1747     ierr = VecSetValues(pcis->vec1_N,pcbddc->local_primal_size,pcbddc->local_primal_ref_node,array,INSERT_VALUES);CHKERRQ(ierr);
1748     ierr = VecRestoreArray(pcbddc->vec1_P,&array);CHKERRQ(ierr);
1749     ierr = VecAssemblyBegin(pcis->vec1_N);CHKERRQ(ierr);
1750     ierr = VecAssemblyEnd(pcis->vec1_N);CHKERRQ(ierr);
1751     ierr = VecScatterBegin(pcis->N_to_B,pcis->vec1_N,pcis->vec2_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1752     ierr = VecScatterEnd(pcis->N_to_B,pcis->vec1_N,pcis->vec2_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1753     ierr = VecDuplicate(pcis->vec2_B,&vec_check_B);CHKERRQ(ierr);
1754     ierr = VecCopy(pcis->vec2_B,vec_check_B);CHKERRQ(ierr);
1755 
1756     /* assemble rhs for coarse problem */
1757     /* widetilde{S}_\Gamma w_\Gamma + \widetilde{B0}^T_B p0 */
1758     /* local with Schur */
1759     ierr = MatMult(S_j,pcis->vec2_B,pcis->vec1_B);CHKERRQ(ierr);
1760     if (zerodiag) {
1761       ierr = VecGetArray(dummy_vec,&array);CHKERRQ(ierr);
1762       array[0] = p0_check;
1763       ierr = VecRestoreArray(dummy_vec,&array);CHKERRQ(ierr);
1764       ierr = MatMultTransposeAdd(B0_B,dummy_vec,pcis->vec1_B,pcis->vec1_B);CHKERRQ(ierr);
1765     }
1766     /* sum on primal nodes the local contributions */
1767     ierr = VecScatterBegin(pcis->N_to_B,pcis->vec1_B,pcis->vec1_N,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1768     ierr = VecScatterEnd(pcis->N_to_B,pcis->vec1_B,pcis->vec1_N,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1769     ierr = VecGetArray(pcis->vec1_N,&array);CHKERRQ(ierr);
1770     ierr = VecGetArray(pcbddc->vec1_P,&array2);CHKERRQ(ierr);
1771     for (i=0;i<pcbddc->local_primal_size;i++) array2[i] = array[pcbddc->local_primal_ref_node[i]];
1772     ierr = VecRestoreArray(pcbddc->vec1_P,&array2);CHKERRQ(ierr);
1773     ierr = VecRestoreArray(pcis->vec1_N,&array);CHKERRQ(ierr);
1774     ierr = VecSet(pcbddc->coarse_vec,0.);CHKERRQ(ierr);
1775     ierr = VecScatterBegin(pcbddc->coarse_loc_to_glob,pcbddc->vec1_P,pcbddc->coarse_vec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1776     ierr = VecScatterEnd(pcbddc->coarse_loc_to_glob,pcbddc->vec1_P,pcbddc->coarse_vec,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1777     ierr = VecScatterBegin(pcbddc->coarse_loc_to_glob,pcbddc->coarse_vec,pcbddc->vec1_P,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1778     ierr = VecScatterEnd(pcbddc->coarse_loc_to_glob,pcbddc->coarse_vec,pcbddc->vec1_P,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1779     ierr = VecGetArray(pcbddc->vec1_P,&array);CHKERRQ(ierr);
1780     /* scale primal nodes (BDDC sums contibutions) */
1781     ierr = VecPointwiseMult(pcbddc->vec1_P,vec_scale_P,pcbddc->vec1_P);CHKERRQ(ierr);
1782     ierr = VecSetValues(pcis->vec1_N,pcbddc->local_primal_size,pcbddc->local_primal_ref_node,array,INSERT_VALUES);CHKERRQ(ierr);
1783     ierr = VecRestoreArray(pcbddc->vec1_P,&array);CHKERRQ(ierr);
1784     ierr = VecAssemblyBegin(pcis->vec1_N);CHKERRQ(ierr);
1785     ierr = VecAssemblyEnd(pcis->vec1_N);CHKERRQ(ierr);
1786     ierr = VecScatterBegin(pcis->N_to_B,pcis->vec1_N,pcis->vec1_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1787     ierr = VecScatterEnd(pcis->N_to_B,pcis->vec1_N,pcis->vec1_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1788     /* global: \widetilde{B0}_B w_\Gamma */
1789     if (zerodiag) {
1790       ierr = MatMult(B0_B,pcis->vec2_B,dummy_vec);CHKERRQ(ierr);
1791       ierr = VecGetArray(dummy_vec,&array);CHKERRQ(ierr);
1792       pcbddc->benign_p0 = array[0];
1793       ierr = VecRestoreArray(dummy_vec,&array);CHKERRQ(ierr);
1794     } else {
1795       pcbddc->benign_p0 = 0.;
1796     }
1797     /* BDDC */
1798     ierr = VecSet(pcis->vec1_D,0.);CHKERRQ(ierr);
1799     ierr = PCBDDCApplyInterfacePreconditioner(pc,PETSC_FALSE);CHKERRQ(ierr);
1800 
1801     ierr = VecCopy(pcis->vec1_B,pcis->vec2_B);CHKERRQ(ierr);
1802     ierr = VecAXPY(pcis->vec1_B,-1.0,vec_check_B);CHKERRQ(ierr);
1803     ierr = VecNorm(pcis->vec1_B,NORM_INFINITY,&norm);CHKERRQ(ierr);
1804     PetscPrintf(PETSC_COMM_SELF,"[%d] BDDC local error is %1.4e\n",PetscGlobalRank,norm);
1805     if (pcbddc->benign_p0_lidx >= 0) {
1806       PetscPrintf(PETSC_COMM_SELF,"[%d] BDDC p0 error is %1.4e\n",PetscGlobalRank,PetscAbsScalar(pcbddc->benign_p0-p0_check));
1807     }
1808 
1809     ierr = VecDestroy(&vec_scale_P);CHKERRQ(ierr);
1810     ierr = VecDestroy(&vec_check_B);CHKERRQ(ierr);
1811     ierr = VecDestroy(&dummy_vec);CHKERRQ(ierr);
1812     ierr = MatDestroy(&S_j);CHKERRQ(ierr);
1813     ierr = MatDestroy(&B0);CHKERRQ(ierr);
1814     ierr = MatDestroy(&B0_B);CHKERRQ(ierr);
1815   }
1816   ierr = ISDestroy(&zerodiag);CHKERRQ(ierr);
1817 
1818   if (pcbddc->dbg_flag) {
1819     ierr = PetscViewerASCIISubtractTab(pcbddc->dbg_viewer,2*pcbddc->current_level);CHKERRQ(ierr);
1820   }
1821   PetscFunctionReturn(0);
1822 }
1823 
1824 /* -------------------------------------------------------------------------- */
1825 /*
1826    PCApply_BDDC - Applies the BDDC operator to a vector.
1827 
1828    Input Parameters:
1829 +  pc - the preconditioner context
1830 -  r - input vector (global)
1831 
1832    Output Parameter:
1833 .  z - output vector (global)
1834 
1835    Application Interface Routine: PCApply()
1836  */
1837 #undef __FUNCT__
1838 #define __FUNCT__ "PCApply_BDDC"
1839 PetscErrorCode PCApply_BDDC(PC pc,Vec r,Vec z)
1840 {
1841   PC_IS             *pcis = (PC_IS*)(pc->data);
1842   PC_BDDC           *pcbddc = (PC_BDDC*)(pc->data);
1843   PetscInt          n_B = pcis->n_B, n_D = pcis->n - n_B;
1844   PetscErrorCode    ierr;
1845   const PetscScalar one = 1.0;
1846   const PetscScalar m_one = -1.0;
1847   const PetscScalar zero = 0.0;
1848 
1849 /* This code is similar to that provided in nn.c for PCNN
1850    NN interface preconditioner changed to BDDC
1851    Added support for M_3 preconditioner in the reference article (code is active if pcbddc->switch_static == PETSC_TRUE) */
1852 
1853   PetscFunctionBegin;
1854   if (pcbddc->benign_saddle_point) { /* extract p0 from r */
1855     ierr = PCBDDCBenignPopOrPushP0(pc,r,PETSC_TRUE);CHKERRQ(ierr);
1856   }
1857   if (!pcbddc->use_exact_dirichlet_trick) {
1858     ierr = VecCopy(r,z);CHKERRQ(ierr);
1859     /* First Dirichlet solve */
1860     ierr = VecScatterBegin(pcis->global_to_D,r,pcis->vec1_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1861     ierr = VecScatterEnd(pcis->global_to_D,r,pcis->vec1_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1862     /*
1863       Assembling right hand side for BDDC operator
1864       - pcis->vec1_D for the Dirichlet part (if needed, i.e. pcbddc->switch_static == PETSC_TRUE)
1865       - pcis->vec1_B the interface part of the global vector z
1866     */
1867     if (n_D) {
1868       ierr = KSPSolve(pcbddc->ksp_D,pcis->vec1_D,pcis->vec2_D);CHKERRQ(ierr);
1869       ierr = VecScale(pcis->vec2_D,m_one);CHKERRQ(ierr);
1870       if (pcbddc->switch_static) { ierr = MatMultAdd(pcis->A_II,pcis->vec2_D,pcis->vec1_D,pcis->vec1_D);CHKERRQ(ierr); }
1871       ierr = MatMult(pcis->A_BI,pcis->vec2_D,pcis->vec1_B);CHKERRQ(ierr);
1872     } else {
1873       ierr = VecSet(pcis->vec1_B,zero);CHKERRQ(ierr);
1874     }
1875     ierr = VecScatterBegin(pcis->global_to_B,pcis->vec1_B,z,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1876     ierr = VecScatterEnd(pcis->global_to_B,pcis->vec1_B,z,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1877     ierr = PCBDDCScalingRestriction(pc,z,pcis->vec1_B);CHKERRQ(ierr);
1878   } else {
1879     if (pcbddc->switch_static) {
1880       ierr = VecSet(pcis->vec1_D,zero);CHKERRQ(ierr);
1881     }
1882     ierr = PCBDDCScalingRestriction(pc,r,pcis->vec1_B);CHKERRQ(ierr);
1883   }
1884 
1885   /* Apply interface preconditioner
1886      input/output vecs: pcis->vec1_B and pcis->vec1_D */
1887   ierr = PCBDDCApplyInterfacePreconditioner(pc,PETSC_FALSE);CHKERRQ(ierr);
1888 
1889   /* Apply transpose of partition of unity operator */
1890   ierr = PCBDDCScalingExtension(pc,pcis->vec1_B,z);CHKERRQ(ierr);
1891 
1892   /* Second Dirichlet solve and assembling of output */
1893   ierr = VecScatterBegin(pcis->global_to_B,z,pcis->vec1_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1894   ierr = VecScatterEnd(pcis->global_to_B,z,pcis->vec1_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1895   if (n_B) {
1896     ierr = MatMult(pcis->A_IB,pcis->vec1_B,pcis->vec3_D);CHKERRQ(ierr);
1897     if (pcbddc->switch_static) { ierr = MatMultAdd(pcis->A_II,pcis->vec1_D,pcis->vec3_D,pcis->vec3_D);CHKERRQ(ierr); }
1898   } else if (pcbddc->switch_static) {
1899     ierr = MatMult(pcis->A_II,pcis->vec1_D,pcis->vec3_D);CHKERRQ(ierr);
1900   }
1901   ierr = KSPSolve(pcbddc->ksp_D,pcis->vec3_D,pcis->vec4_D);CHKERRQ(ierr);
1902 
1903   if (!pcbddc->use_exact_dirichlet_trick) {
1904     if (pcbddc->switch_static) {
1905       ierr = VecAXPBYPCZ(pcis->vec2_D,m_one,one,m_one,pcis->vec4_D,pcis->vec1_D);CHKERRQ(ierr);
1906     } else {
1907       ierr = VecAXPBY(pcis->vec2_D,m_one,m_one,pcis->vec4_D);CHKERRQ(ierr);
1908     }
1909     ierr = VecScatterBegin(pcis->global_to_D,pcis->vec2_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1910     ierr = VecScatterEnd(pcis->global_to_D,pcis->vec2_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1911   } else {
1912     if (pcbddc->switch_static) {
1913       ierr = VecAXPBY(pcis->vec4_D,one,m_one,pcis->vec1_D);CHKERRQ(ierr);
1914     } else {
1915       ierr = VecScale(pcis->vec4_D,m_one);CHKERRQ(ierr);
1916     }
1917     ierr = VecScatterBegin(pcis->global_to_D,pcis->vec4_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1918     ierr = VecScatterEnd(pcis->global_to_D,pcis->vec4_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1919   }
1920 
1921   if (pcbddc->benign_saddle_point) { /* push p0 (computed in PCBDDCApplyInterface) */
1922     ierr = PCBDDCBenignPopOrPushP0(pc,z,PETSC_FALSE);CHKERRQ(ierr);
1923   }
1924   PetscFunctionReturn(0);
1925 }
1926 
1927 /* -------------------------------------------------------------------------- */
1928 /*
1929    PCApplyTranspose_BDDC - Applies the transpose of the BDDC operator to a vector.
1930 
1931    Input Parameters:
1932 +  pc - the preconditioner context
1933 -  r - input vector (global)
1934 
1935    Output Parameter:
1936 .  z - output vector (global)
1937 
1938    Application Interface Routine: PCApplyTranspose()
1939  */
1940 #undef __FUNCT__
1941 #define __FUNCT__ "PCApplyTranspose_BDDC"
1942 PetscErrorCode PCApplyTranspose_BDDC(PC pc,Vec r,Vec z)
1943 {
1944   PC_IS             *pcis = (PC_IS*)(pc->data);
1945   PC_BDDC           *pcbddc = (PC_BDDC*)(pc->data);
1946   PetscInt          n_B = pcis->n_B, n_D = pcis->n - n_B;
1947   PetscErrorCode    ierr;
1948   const PetscScalar one = 1.0;
1949   const PetscScalar m_one = -1.0;
1950   const PetscScalar zero = 0.0;
1951 
1952   PetscFunctionBegin;
1953   if (!pcbddc->use_exact_dirichlet_trick) {
1954     ierr = VecCopy(r,z);CHKERRQ(ierr);
1955     /* First Dirichlet solve */
1956     ierr = VecScatterBegin(pcis->global_to_D,r,pcis->vec1_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1957     ierr = VecScatterEnd(pcis->global_to_D,r,pcis->vec1_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1958     /*
1959       Assembling right hand side for BDDC operator
1960       - pcis->vec1_D for the Dirichlet part (if needed, i.e. pcbddc->switch_static == PETSC_TRUE)
1961       - pcis->vec1_B the interface part of the global vector z
1962     */
1963     if (n_D) {
1964       ierr = KSPSolveTranspose(pcbddc->ksp_D,pcis->vec1_D,pcis->vec2_D);CHKERRQ(ierr);
1965       ierr = VecScale(pcis->vec2_D,m_one);CHKERRQ(ierr);
1966       if (pcbddc->switch_static) { ierr = MatMultTransposeAdd(pcis->A_II,pcis->vec2_D,pcis->vec1_D,pcis->vec1_D);CHKERRQ(ierr); }
1967       ierr = MatMultTranspose(pcis->A_IB,pcis->vec2_D,pcis->vec1_B);CHKERRQ(ierr);
1968     } else {
1969       ierr = VecSet(pcis->vec1_B,zero);CHKERRQ(ierr);
1970     }
1971     ierr = VecScatterBegin(pcis->global_to_B,pcis->vec1_B,z,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1972     ierr = VecScatterEnd(pcis->global_to_B,pcis->vec1_B,z,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1973     ierr = PCBDDCScalingRestriction(pc,z,pcis->vec1_B);CHKERRQ(ierr);
1974   } else {
1975     if (pcbddc->switch_static) {
1976       ierr = VecSet(pcis->vec1_D,zero);CHKERRQ(ierr);
1977     }
1978     ierr = PCBDDCScalingRestriction(pc,r,pcis->vec1_B);CHKERRQ(ierr);
1979   }
1980 
1981   /* Apply interface preconditioner
1982      input/output vecs: pcis->vec1_B and pcis->vec1_D */
1983   ierr = PCBDDCApplyInterfacePreconditioner(pc,PETSC_TRUE);CHKERRQ(ierr);
1984 
1985   /* Apply transpose of partition of unity operator */
1986   ierr = PCBDDCScalingExtension(pc,pcis->vec1_B,z);CHKERRQ(ierr);
1987 
1988   /* Second Dirichlet solve and assembling of output */
1989   ierr = VecScatterBegin(pcis->global_to_B,z,pcis->vec1_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1990   ierr = VecScatterEnd(pcis->global_to_B,z,pcis->vec1_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1991   if (n_B) {
1992     ierr = MatMultTranspose(pcis->A_BI,pcis->vec1_B,pcis->vec3_D);CHKERRQ(ierr);
1993     if (pcbddc->switch_static) { ierr = MatMultTransposeAdd(pcis->A_II,pcis->vec1_D,pcis->vec3_D,pcis->vec3_D);CHKERRQ(ierr); }
1994   } else if (pcbddc->switch_static) {
1995     ierr = MatMultTranspose(pcis->A_II,pcis->vec1_D,pcis->vec3_D);CHKERRQ(ierr);
1996   }
1997   ierr = KSPSolveTranspose(pcbddc->ksp_D,pcis->vec3_D,pcis->vec4_D);CHKERRQ(ierr);
1998   if (!pcbddc->use_exact_dirichlet_trick) {
1999     if (pcbddc->switch_static) {
2000       ierr = VecAXPBYPCZ(pcis->vec2_D,m_one,one,m_one,pcis->vec4_D,pcis->vec1_D);CHKERRQ(ierr);
2001     } else {
2002       ierr = VecAXPBY(pcis->vec2_D,m_one,m_one,pcis->vec4_D);CHKERRQ(ierr);
2003     }
2004     ierr = VecScatterBegin(pcis->global_to_D,pcis->vec2_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2005     ierr = VecScatterEnd(pcis->global_to_D,pcis->vec2_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2006   } else {
2007     if (pcbddc->switch_static) {
2008       ierr = VecAXPBY(pcis->vec4_D,one,m_one,pcis->vec1_D);CHKERRQ(ierr);
2009     } else {
2010       ierr = VecScale(pcis->vec4_D,m_one);CHKERRQ(ierr);
2011     }
2012     ierr = VecScatterBegin(pcis->global_to_D,pcis->vec4_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2013     ierr = VecScatterEnd(pcis->global_to_D,pcis->vec4_D,z,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2014   }
2015   PetscFunctionReturn(0);
2016 }
2017 /* -------------------------------------------------------------------------- */
2018 
2019 #undef __FUNCT__
2020 #define __FUNCT__ "PCDestroy_BDDC"
2021 PetscErrorCode PCDestroy_BDDC(PC pc)
2022 {
2023   PC_BDDC        *pcbddc = (PC_BDDC*)pc->data;
2024   PetscErrorCode ierr;
2025 
2026   PetscFunctionBegin;
2027   /* free data created by PCIS */
2028   ierr = PCISDestroy(pc);CHKERRQ(ierr);
2029   /* free BDDC custom data  */
2030   ierr = PCBDDCResetCustomization(pc);CHKERRQ(ierr);
2031   /* destroy objects related to topography */
2032   ierr = PCBDDCResetTopography(pc);CHKERRQ(ierr);
2033   /* free allocated graph structure */
2034   ierr = PetscFree(pcbddc->mat_graph);CHKERRQ(ierr);
2035   /* free allocated sub schurs structure */
2036   ierr = PetscFree(pcbddc->sub_schurs);CHKERRQ(ierr);
2037   /* destroy objects for scaling operator */
2038   ierr = PCBDDCScalingDestroy(pc);CHKERRQ(ierr);
2039   ierr = PetscFree(pcbddc->deluxe_ctx);CHKERRQ(ierr);
2040   /* free solvers stuff */
2041   ierr = PCBDDCResetSolvers(pc);CHKERRQ(ierr);
2042   /* free global vectors needed in presolve */
2043   ierr = VecDestroy(&pcbddc->temp_solution);CHKERRQ(ierr);
2044   ierr = VecDestroy(&pcbddc->original_rhs);CHKERRQ(ierr);
2045   /* free stuff for change of basis hooks */
2046   if (pcbddc->new_global_mat) {
2047     PCBDDCChange_ctx change_ctx;
2048     ierr = MatShellGetContext(pcbddc->new_global_mat,&change_ctx);CHKERRQ(ierr);
2049     ierr = MatDestroy(&change_ctx->original_mat);CHKERRQ(ierr);
2050     ierr = MatDestroy(&change_ctx->global_change);CHKERRQ(ierr);
2051     ierr = VecDestroyVecs(2,&change_ctx->work);CHKERRQ(ierr);
2052     ierr = PetscFree(change_ctx);CHKERRQ(ierr);
2053   }
2054   ierr = MatDestroy(&pcbddc->new_global_mat);CHKERRQ(ierr);
2055   /* remove functions */
2056   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetChangeOfBasisMat_C",NULL);CHKERRQ(ierr);
2057   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetPrimalVerticesLocalIS_C",NULL);CHKERRQ(ierr);
2058   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetCoarseningRatio_C",NULL);CHKERRQ(ierr);
2059   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetLevel_C",NULL);CHKERRQ(ierr);
2060   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetUseExactDirichlet_C",NULL);CHKERRQ(ierr);
2061   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetLevels_C",NULL);CHKERRQ(ierr);
2062   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetNullSpace_C",NULL);CHKERRQ(ierr);
2063   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDirichletBoundaries_C",NULL);CHKERRQ(ierr);
2064   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDirichletBoundariesLocal_C",NULL);CHKERRQ(ierr);
2065   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetNeumannBoundaries_C",NULL);CHKERRQ(ierr);
2066   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetNeumannBoundariesLocal_C",NULL);CHKERRQ(ierr);
2067   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetDirichletBoundaries_C",NULL);CHKERRQ(ierr);
2068   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetDirichletBoundariesLocal_C",NULL);CHKERRQ(ierr);
2069   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetNeumannBoundaries_C",NULL);CHKERRQ(ierr);
2070   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetNeumannBoundariesLocal_C",NULL);CHKERRQ(ierr);
2071   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDofsSplitting_C",NULL);CHKERRQ(ierr);
2072   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDofsSplittingLocal_C",NULL);CHKERRQ(ierr);
2073   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetLocalAdjacencyGraph_C",NULL);CHKERRQ(ierr);
2074   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCCreateFETIDPOperators_C",NULL);CHKERRQ(ierr);
2075   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCMatFETIDPGetRHS_C",NULL);CHKERRQ(ierr);
2076   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCMatFETIDPGetSolution_C",NULL);CHKERRQ(ierr);
2077   /* Free the private data structure */
2078   ierr = PetscFree(pc->data);CHKERRQ(ierr);
2079   PetscFunctionReturn(0);
2080 }
2081 /* -------------------------------------------------------------------------- */
2082 
2083 #undef __FUNCT__
2084 #define __FUNCT__ "PCBDDCMatFETIDPGetRHS_BDDC"
2085 static PetscErrorCode PCBDDCMatFETIDPGetRHS_BDDC(Mat fetidp_mat, Vec standard_rhs, Vec fetidp_flux_rhs)
2086 {
2087   FETIDPMat_ctx  mat_ctx;
2088   Vec            copy_standard_rhs;
2089   PC_IS*         pcis;
2090   PC_BDDC*       pcbddc;
2091   PetscErrorCode ierr;
2092 
2093   PetscFunctionBegin;
2094   ierr = MatShellGetContext(fetidp_mat,&mat_ctx);CHKERRQ(ierr);
2095   pcis = (PC_IS*)mat_ctx->pc->data;
2096   pcbddc = (PC_BDDC*)mat_ctx->pc->data;
2097 
2098   /*
2099      change of basis for physical rhs if needed
2100      It also changes the rhs in case of dirichlet boundaries
2101      TODO: better management when FETIDP will have its own class
2102   */
2103   ierr = VecDuplicate(standard_rhs,&copy_standard_rhs);CHKERRQ(ierr);
2104   ierr = VecCopy(standard_rhs,copy_standard_rhs);CHKERRQ(ierr);
2105   ierr = PCPreSolve_BDDC(mat_ctx->pc,NULL,copy_standard_rhs,NULL);CHKERRQ(ierr);
2106   /* store vectors for computation of fetidp final solution */
2107   ierr = VecScatterBegin(pcis->global_to_D,copy_standard_rhs,mat_ctx->temp_solution_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2108   ierr = VecScatterEnd(pcis->global_to_D,copy_standard_rhs,mat_ctx->temp_solution_D,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2109   /* scale rhs since it should be unassembled */
2110   /* TODO use counter scaling? (also below) */
2111   ierr = VecScatterBegin(pcis->global_to_B,copy_standard_rhs,mat_ctx->temp_solution_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2112   ierr = VecScatterEnd(pcis->global_to_B,copy_standard_rhs,mat_ctx->temp_solution_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2113   /* Apply partition of unity */
2114   ierr = VecPointwiseMult(mat_ctx->temp_solution_B,pcis->D,mat_ctx->temp_solution_B);CHKERRQ(ierr);
2115   /* ierr = PCBDDCScalingRestriction(mat_ctx->pc,copy_standard_rhs,mat_ctx->temp_solution_B);CHKERRQ(ierr); */
2116   if (!pcbddc->switch_static) {
2117     /* compute partially subassembled Schur complement right-hand side */
2118     ierr = KSPSolve(pcbddc->ksp_D,mat_ctx->temp_solution_D,pcis->vec1_D);CHKERRQ(ierr);
2119     ierr = MatMult(pcis->A_BI,pcis->vec1_D,pcis->vec1_B);CHKERRQ(ierr);
2120     ierr = VecAXPY(mat_ctx->temp_solution_B,-1.0,pcis->vec1_B);CHKERRQ(ierr);
2121     ierr = VecSet(copy_standard_rhs,0.0);CHKERRQ(ierr);
2122     ierr = VecScatterBegin(pcis->global_to_B,mat_ctx->temp_solution_B,copy_standard_rhs,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2123     ierr = VecScatterEnd(pcis->global_to_B,mat_ctx->temp_solution_B,copy_standard_rhs,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2124     /* ierr = PCBDDCScalingRestriction(mat_ctx->pc,copy_standard_rhs,mat_ctx->temp_solution_B);CHKERRQ(ierr); */
2125     ierr = VecScatterBegin(pcis->global_to_B,copy_standard_rhs,mat_ctx->temp_solution_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2126     ierr = VecScatterEnd(pcis->global_to_B,copy_standard_rhs,mat_ctx->temp_solution_B,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2127     ierr = VecPointwiseMult(mat_ctx->temp_solution_B,pcis->D,mat_ctx->temp_solution_B);CHKERRQ(ierr);
2128   }
2129   ierr = VecDestroy(&copy_standard_rhs);CHKERRQ(ierr);
2130   /* BDDC rhs */
2131   ierr = VecCopy(mat_ctx->temp_solution_B,pcis->vec1_B);CHKERRQ(ierr);
2132   if (pcbddc->switch_static) {
2133     ierr = VecCopy(mat_ctx->temp_solution_D,pcis->vec1_D);CHKERRQ(ierr);
2134   }
2135   /* apply BDDC */
2136   ierr = PCBDDCApplyInterfacePreconditioner(mat_ctx->pc,PETSC_FALSE);CHKERRQ(ierr);
2137   /* Application of B_delta and assembling of rhs for fetidp fluxes */
2138   ierr = VecSet(fetidp_flux_rhs,0.0);CHKERRQ(ierr);
2139   ierr = MatMult(mat_ctx->B_delta,pcis->vec1_B,mat_ctx->lambda_local);CHKERRQ(ierr);
2140   ierr = VecScatterBegin(mat_ctx->l2g_lambda,mat_ctx->lambda_local,fetidp_flux_rhs,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2141   ierr = VecScatterEnd(mat_ctx->l2g_lambda,mat_ctx->lambda_local,fetidp_flux_rhs,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2142   PetscFunctionReturn(0);
2143 }
2144 
2145 #undef __FUNCT__
2146 #define __FUNCT__ "PCBDDCMatFETIDPGetRHS"
2147 /*@
2148  PCBDDCMatFETIDPGetRHS - Compute the right-hand side for FETI-DP linear system using the physical right-hand side
2149 
2150    Collective
2151 
2152    Input Parameters:
2153 +  fetidp_mat      - the FETI-DP matrix object obtained by a call to PCBDDCCreateFETIDPOperators
2154 -  standard_rhs    - the right-hand side of the original linear system
2155 
2156    Output Parameters:
2157 .  fetidp_flux_rhs - the right-hand side for the FETI-DP linear system
2158 
2159    Level: developer
2160 
2161    Notes:
2162 
2163 .seealso: PCBDDC, PCBDDCCreateFETIDPOperators, PCBDDCMatFETIDPGetSolution
2164 @*/
2165 PetscErrorCode PCBDDCMatFETIDPGetRHS(Mat fetidp_mat, Vec standard_rhs, Vec fetidp_flux_rhs)
2166 {
2167   FETIDPMat_ctx  mat_ctx;
2168   PetscErrorCode ierr;
2169 
2170   PetscFunctionBegin;
2171   ierr = MatShellGetContext(fetidp_mat,&mat_ctx);CHKERRQ(ierr);
2172   ierr = PetscTryMethod(mat_ctx->pc,"PCBDDCMatFETIDPGetRHS_C",(Mat,Vec,Vec),(fetidp_mat,standard_rhs,fetidp_flux_rhs));CHKERRQ(ierr);
2173   PetscFunctionReturn(0);
2174 }
2175 /* -------------------------------------------------------------------------- */
2176 
2177 #undef __FUNCT__
2178 #define __FUNCT__ "PCBDDCMatFETIDPGetSolution_BDDC"
2179 static PetscErrorCode PCBDDCMatFETIDPGetSolution_BDDC(Mat fetidp_mat, Vec fetidp_flux_sol, Vec standard_sol)
2180 {
2181   FETIDPMat_ctx  mat_ctx;
2182   PC_IS*         pcis;
2183   PC_BDDC*       pcbddc;
2184   PetscErrorCode ierr;
2185 
2186   PetscFunctionBegin;
2187   ierr = MatShellGetContext(fetidp_mat,&mat_ctx);CHKERRQ(ierr);
2188   pcis = (PC_IS*)mat_ctx->pc->data;
2189   pcbddc = (PC_BDDC*)mat_ctx->pc->data;
2190 
2191   /* apply B_delta^T */
2192   ierr = VecScatterBegin(mat_ctx->l2g_lambda,fetidp_flux_sol,mat_ctx->lambda_local,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2193   ierr = VecScatterEnd  (mat_ctx->l2g_lambda,fetidp_flux_sol,mat_ctx->lambda_local,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2194   ierr = MatMultTranspose(mat_ctx->B_delta,mat_ctx->lambda_local,pcis->vec1_B);CHKERRQ(ierr);
2195   /* compute rhs for BDDC application */
2196   ierr = VecAYPX(pcis->vec1_B,-1.0,mat_ctx->temp_solution_B);CHKERRQ(ierr);
2197   if (pcbddc->switch_static) {
2198     ierr = VecCopy(mat_ctx->temp_solution_D,pcis->vec1_D);CHKERRQ(ierr);
2199   }
2200   /* apply BDDC */
2201   ierr = PCBDDCApplyInterfacePreconditioner(mat_ctx->pc,PETSC_FALSE);CHKERRQ(ierr);
2202   /* put values into standard global vector */
2203   ierr = VecScatterBegin(pcis->global_to_B,pcis->vec1_B,standard_sol,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2204   ierr = VecScatterEnd  (pcis->global_to_B,pcis->vec1_B,standard_sol,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2205   if (!pcbddc->switch_static) {
2206     /* compute values into the interior if solved for the partially subassembled Schur complement */
2207     ierr = MatMult(pcis->A_IB,pcis->vec1_B,pcis->vec1_D);CHKERRQ(ierr);
2208     ierr = VecAXPY(mat_ctx->temp_solution_D,-1.0,pcis->vec1_D);CHKERRQ(ierr);
2209     ierr = KSPSolve(pcbddc->ksp_D,mat_ctx->temp_solution_D,pcis->vec1_D);CHKERRQ(ierr);
2210   }
2211   ierr = VecScatterBegin(pcis->global_to_D,pcis->vec1_D,standard_sol,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2212   ierr = VecScatterEnd  (pcis->global_to_D,pcis->vec1_D,standard_sol,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
2213   /* final change of basis if needed
2214      Is also sums the dirichlet part removed during RHS assembling */
2215   ierr = PCPostSolve_BDDC(mat_ctx->pc,NULL,NULL,standard_sol);CHKERRQ(ierr);
2216   PetscFunctionReturn(0);
2217 }
2218 
2219 #undef __FUNCT__
2220 #define __FUNCT__ "PCBDDCMatFETIDPGetSolution"
2221 /*@
2222  PCBDDCMatFETIDPGetSolution - Compute the physical solution using the solution of the FETI-DP linear system
2223 
2224    Collective
2225 
2226    Input Parameters:
2227 +  fetidp_mat      - the FETI-DP matrix obtained by a call to PCBDDCCreateFETIDPOperators
2228 -  fetidp_flux_sol - the solution of the FETI-DP linear system
2229 
2230    Output Parameters:
2231 .  standard_sol    - the solution defined on the physical domain
2232 
2233    Level: developer
2234 
2235    Notes:
2236 
2237 .seealso: PCBDDC, PCBDDCCreateFETIDPOperators, PCBDDCMatFETIDPGetRHS
2238 @*/
2239 PetscErrorCode PCBDDCMatFETIDPGetSolution(Mat fetidp_mat, Vec fetidp_flux_sol, Vec standard_sol)
2240 {
2241   FETIDPMat_ctx  mat_ctx;
2242   PetscErrorCode ierr;
2243 
2244   PetscFunctionBegin;
2245   ierr = MatShellGetContext(fetidp_mat,&mat_ctx);CHKERRQ(ierr);
2246   ierr = PetscTryMethod(mat_ctx->pc,"PCBDDCMatFETIDPGetSolution_C",(Mat,Vec,Vec),(fetidp_mat,fetidp_flux_sol,standard_sol));CHKERRQ(ierr);
2247   PetscFunctionReturn(0);
2248 }
2249 /* -------------------------------------------------------------------------- */
2250 
2251 extern PetscErrorCode FETIDPMatMult(Mat,Vec,Vec);
2252 extern PetscErrorCode FETIDPMatMultTranspose(Mat,Vec,Vec);
2253 extern PetscErrorCode PCBDDCDestroyFETIDPMat(Mat);
2254 extern PetscErrorCode FETIDPPCApply(PC,Vec,Vec);
2255 extern PetscErrorCode FETIDPPCApplyTranspose(PC,Vec,Vec);
2256 extern PetscErrorCode PCBDDCDestroyFETIDPPC(PC);
2257 
2258 #undef __FUNCT__
2259 #define __FUNCT__ "PCBDDCCreateFETIDPOperators_BDDC"
2260 static PetscErrorCode PCBDDCCreateFETIDPOperators_BDDC(PC pc, Mat *fetidp_mat, PC *fetidp_pc)
2261 {
2262 
2263   FETIDPMat_ctx  fetidpmat_ctx;
2264   Mat            newmat;
2265   FETIDPPC_ctx   fetidppc_ctx;
2266   PC             newpc;
2267   MPI_Comm       comm;
2268   PetscErrorCode ierr;
2269 
2270   PetscFunctionBegin;
2271   ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
2272   /* FETIDP linear matrix */
2273   ierr = PCBDDCCreateFETIDPMatContext(pc,&fetidpmat_ctx);CHKERRQ(ierr);
2274   ierr = PCBDDCSetupFETIDPMatContext(fetidpmat_ctx);CHKERRQ(ierr);
2275   ierr = MatCreateShell(comm,PETSC_DECIDE,PETSC_DECIDE,fetidpmat_ctx->n_lambda,fetidpmat_ctx->n_lambda,fetidpmat_ctx,&newmat);CHKERRQ(ierr);
2276   ierr = MatShellSetOperation(newmat,MATOP_MULT,(void (*)(void))FETIDPMatMult);CHKERRQ(ierr);
2277   ierr = MatShellSetOperation(newmat,MATOP_MULT_TRANSPOSE,(void (*)(void))FETIDPMatMultTranspose);CHKERRQ(ierr);
2278   ierr = MatShellSetOperation(newmat,MATOP_DESTROY,(void (*)(void))PCBDDCDestroyFETIDPMat);CHKERRQ(ierr);
2279   ierr = MatSetUp(newmat);CHKERRQ(ierr);
2280   /* FETIDP preconditioner */
2281   ierr = PCBDDCCreateFETIDPPCContext(pc,&fetidppc_ctx);CHKERRQ(ierr);
2282   ierr = PCBDDCSetupFETIDPPCContext(newmat,fetidppc_ctx);CHKERRQ(ierr);
2283   ierr = PCCreate(comm,&newpc);CHKERRQ(ierr);
2284   ierr = PCSetType(newpc,PCSHELL);CHKERRQ(ierr);
2285   ierr = PCShellSetContext(newpc,fetidppc_ctx);CHKERRQ(ierr);
2286   ierr = PCShellSetApply(newpc,FETIDPPCApply);CHKERRQ(ierr);
2287   ierr = PCShellSetApplyTranspose(newpc,FETIDPPCApplyTranspose);CHKERRQ(ierr);
2288   ierr = PCShellSetDestroy(newpc,PCBDDCDestroyFETIDPPC);CHKERRQ(ierr);
2289   ierr = PCSetOperators(newpc,newmat,newmat);CHKERRQ(ierr);
2290   ierr = PCSetUp(newpc);CHKERRQ(ierr);
2291   /* return pointers for objects created */
2292   *fetidp_mat=newmat;
2293   *fetidp_pc=newpc;
2294   PetscFunctionReturn(0);
2295 }
2296 
2297 #undef __FUNCT__
2298 #define __FUNCT__ "PCBDDCCreateFETIDPOperators"
2299 /*@
2300  PCBDDCCreateFETIDPOperators - Create FETI-DP operators
2301 
2302    Collective
2303 
2304    Input Parameters:
2305 .  pc - the BDDC preconditioning context (setup should have been called before)
2306 
2307    Output Parameters:
2308 +  fetidp_mat - shell FETI-DP matrix object
2309 -  fetidp_pc  - shell Dirichlet preconditioner for FETI-DP matrix
2310 
2311    Options Database Keys:
2312 .    -fetidp_fullyredundant <false> - use or not a fully redundant set of Lagrange multipliers
2313 
2314    Level: developer
2315 
2316    Notes:
2317      Currently the only operations provided for FETI-DP matrix are MatMult and MatMultTranspose
2318 
2319 .seealso: PCBDDC, PCBDDCMatFETIDPGetRHS, PCBDDCMatFETIDPGetSolution
2320 @*/
2321 PetscErrorCode PCBDDCCreateFETIDPOperators(PC pc, Mat *fetidp_mat, PC *fetidp_pc)
2322 {
2323   PetscErrorCode ierr;
2324 
2325   PetscFunctionBegin;
2326   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
2327   if (pc->setupcalled) {
2328     ierr = PetscUseMethod(pc,"PCBDDCCreateFETIDPOperators_C",(PC,Mat*,PC*),(pc,fetidp_mat,fetidp_pc));CHKERRQ(ierr);
2329   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"You must call PCSetup_BDDC() first \n");
2330   PetscFunctionReturn(0);
2331 }
2332 /* -------------------------------------------------------------------------- */
2333 /*MC
2334    PCBDDC - Balancing Domain Decomposition by Constraints.
2335 
2336    An implementation of the BDDC preconditioner based on
2337 
2338 .vb
2339    [1] C. R. Dohrmann. "An approximate BDDC preconditioner", Numerical Linear Algebra with Applications Volume 14, Issue 2, pages 149-168, March 2007
2340    [2] A. Klawonn and O. B. Widlund. "Dual-Primal FETI Methods for Linear Elasticity", http://cs.nyu.edu/csweb/Research/TechReports/TR2004-855/TR2004-855.pdf
2341    [3] J. Mandel, B. Sousedik, C. R. Dohrmann. "Multispace and Multilevel BDDC", http://arxiv.org/abs/0712.3977
2342    [4] C. Pechstein and C. R. Dohrmann. "Modern domain decomposition methods BDDC, deluxe scaling, and an algebraic approach", Seminar talk, Linz, December 2013, http://people.ricam.oeaw.ac.at/c.pechstein/pechstein-bddc2013.pdf
2343 .ve
2344 
2345    The matrix to be preconditioned (Pmat) must be of type MATIS.
2346 
2347    Currently works with MATIS matrices with local matrices of type MATSEQAIJ, MATSEQBAIJ or MATSEQSBAIJ, either with real or complex numbers.
2348 
2349    It also works with unsymmetric and indefinite problems.
2350 
2351    Unlike 'conventional' interface preconditioners, PCBDDC iterates over all degrees of freedom, not just those on the interface. This allows the use of approximate solvers on the subdomains.
2352 
2353    Approximate local solvers are automatically adapted for singular linear problems (see [1]) if the user has provided the nullspace using PCBDDCSetNullSpace()
2354 
2355    Boundary nodes are split in vertices, edges and faces classes using information from the local to global mapping of dofs and the local connectivity graph of nodes. The latter can be customized by using PCBDDCSetLocalAdjacencyGraph()
2356    Additional information on dofs can be provided by using PCBDDCSetDofsSplitting(), PCBDDCSetDirichletBoundaries(), PCBDDCSetNeumannBoundaries(), and PCBDDCSetPrimalVerticesLocalIS()
2357 
2358    Constraints can be customized by attaching a MatNullSpace object to the MATIS matrix via MatSetNearNullSpace(). Non-singular modes are retained via SVD.
2359 
2360    Change of basis is performed similarly to [2] when requested. When more than one constraint is present on a single connected component (i.e. an edge or a face), a robust method based on local QR factorizations is used.
2361    User defined change of basis can be passed to PCBDDC by using PCBDDCSetChangeOfBasisMat()
2362 
2363    The PETSc implementation also supports multilevel BDDC [3]. Coarse grids are partitioned using a MatPartitioning object.
2364 
2365    Adaptive selection of primal constraints [4] is supported for SPD systems with high-contrast in the coefficients if MUMPS is present. Future versions of the code will also consider using MKL_PARDISO or PASTIX.
2366 
2367    An experimental interface to the FETI-DP method is available. FETI-DP operators could be created using PCBDDCCreateFETIDPOperators(). A stand-alone class for the FETI-DP method will be provided in the next releases.
2368    Deluxe scaling is not supported yet for FETI-DP.
2369 
2370    Options Database Keys (some of them, run with -h for a complete list):
2371 
2372 .    -pc_bddc_use_vertices <true> - use or not vertices in primal space
2373 .    -pc_bddc_use_edges <true> - use or not edges in primal space
2374 .    -pc_bddc_use_faces <false> - use or not faces in primal space
2375 .    -pc_bddc_symmetric <true> - symmetric computation of primal basis functions. Specify false for unsymmetric problems
2376 .    -pc_bddc_use_change_of_basis <false> - use change of basis approach (on edges only)
2377 .    -pc_bddc_use_change_on_faces <false> - use change of basis approach on faces if change of basis has been requested
2378 .    -pc_bddc_switch_static <false> - switches from M_2 (default) to M_3 operator (see reference article [1])
2379 .    -pc_bddc_levels <0> - maximum number of levels for multilevel
2380 .    -pc_bddc_coarsening_ratio <8> - number of subdomains which will be aggregated together at the coarser level (e.g. H/h ratio at the coarser level, significative only in the multilevel case)
2381 .    -pc_bddc_redistribute <0> - size of a subset of processors where the coarse problem will be remapped (the value is ignored if not at the coarsest level)
2382 .    -pc_bddc_use_deluxe_scaling <false> - use deluxe scaling
2383 .    -pc_bddc_schur_layers <-1> - select the economic version of deluxe scaling by specifying the number of layers (-1 corresponds to the original deluxe scaling)
2384 .    -pc_bddc_adaptive_threshold <0.0> - when a value greater than one is specified, adaptive selection of constraints is performed on edges and faces (requires deluxe scaling and MUMPS installed)
2385 -    -pc_bddc_check_level <0> - set verbosity level of debugging output
2386 
2387    Options for Dirichlet, Neumann or coarse solver can be set with
2388 .vb
2389       -pc_bddc_dirichlet_
2390       -pc_bddc_neumann_
2391       -pc_bddc_coarse_
2392 .ve
2393    e.g -pc_bddc_dirichlet_ksp_type richardson -pc_bddc_dirichlet_pc_type gamg. PCBDDC uses by default KPSPREONLY and PCLU.
2394 
2395    When using a multilevel approach, solvers' options at the N-th level (N > 1) can be specified as
2396 .vb
2397       -pc_bddc_dirichlet_lN_
2398       -pc_bddc_neumann_lN_
2399       -pc_bddc_coarse_lN_
2400 .ve
2401    Note that level number ranges from the finest (0) to the coarsest (N).
2402    In order to specify options for the BDDC operators at the coarser levels (and not for the solvers), prepend -pc_bddc_coarse_ or -pc_bddc_coarse_l to the option, e.g.
2403 .vb
2404      -pc_bddc_coarse_pc_bddc_adaptive_threshold 5 -pc_bddc_coarse_l1_pc_bddc_redistribute 3
2405 .ve
2406    will use a threshold of 5 for constraints' selection at the first coarse level and will redistribute the coarse problem of the first coarse level on 3 processors
2407 
2408    Level: intermediate
2409 
2410    Developer notes:
2411 
2412    Contributed by Stefano Zampini
2413 
2414 .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC,  MATIS
2415 M*/
2416 
2417 #undef __FUNCT__
2418 #define __FUNCT__ "PCCreate_BDDC"
2419 PETSC_EXTERN PetscErrorCode PCCreate_BDDC(PC pc)
2420 {
2421   PetscErrorCode      ierr;
2422   PC_BDDC             *pcbddc;
2423 
2424   PetscFunctionBegin;
2425   /* Creates the private data structure for this preconditioner and attach it to the PC object. */
2426   ierr      = PetscNewLog(pc,&pcbddc);CHKERRQ(ierr);
2427   pc->data  = (void*)pcbddc;
2428 
2429   /* create PCIS data structure */
2430   ierr = PCISCreate(pc);CHKERRQ(ierr);
2431 
2432   /* BDDC customization */
2433   pcbddc->use_local_adj       = PETSC_TRUE;
2434   pcbddc->use_vertices        = PETSC_TRUE;
2435   pcbddc->use_edges           = PETSC_TRUE;
2436   pcbddc->use_faces           = PETSC_FALSE;
2437   pcbddc->use_change_of_basis = PETSC_FALSE;
2438   pcbddc->use_change_on_faces = PETSC_FALSE;
2439   pcbddc->switch_static       = PETSC_FALSE;
2440   pcbddc->use_nnsp_true       = PETSC_FALSE;
2441   pcbddc->use_qr_single       = PETSC_FALSE;
2442   pcbddc->symmetric_primal    = PETSC_TRUE;
2443   pcbddc->benign_saddle_point = PETSC_FALSE;
2444   pcbddc->dbg_flag            = 0;
2445   /* private */
2446   pcbddc->local_primal_size          = 0;
2447   pcbddc->local_primal_size_cc       = 0;
2448   pcbddc->local_primal_ref_node      = 0;
2449   pcbddc->local_primal_ref_mult      = 0;
2450   pcbddc->n_vertices                 = 0;
2451   pcbddc->primal_indices_local_idxs  = 0;
2452   pcbddc->recompute_topography       = PETSC_FALSE;
2453   pcbddc->coarse_size                = -1;
2454   pcbddc->new_primal_space           = PETSC_FALSE;
2455   pcbddc->new_primal_space_local     = PETSC_FALSE;
2456   pcbddc->global_primal_indices      = 0;
2457   pcbddc->onearnullspace             = 0;
2458   pcbddc->onearnullvecs_state        = 0;
2459   pcbddc->user_primal_vertices       = 0;
2460   pcbddc->NullSpace                  = 0;
2461   pcbddc->temp_solution              = 0;
2462   pcbddc->original_rhs               = 0;
2463   pcbddc->local_mat                  = 0;
2464   pcbddc->ChangeOfBasisMatrix        = 0;
2465   pcbddc->user_ChangeOfBasisMatrix   = 0;
2466   pcbddc->new_global_mat             = 0;
2467   pcbddc->coarse_vec                 = 0;
2468   pcbddc->coarse_ksp                 = 0;
2469   pcbddc->coarse_phi_B               = 0;
2470   pcbddc->coarse_phi_D               = 0;
2471   pcbddc->coarse_psi_B               = 0;
2472   pcbddc->coarse_psi_D               = 0;
2473   pcbddc->vec1_P                     = 0;
2474   pcbddc->vec1_R                     = 0;
2475   pcbddc->vec2_R                     = 0;
2476   pcbddc->local_auxmat1              = 0;
2477   pcbddc->local_auxmat2              = 0;
2478   pcbddc->R_to_B                     = 0;
2479   pcbddc->R_to_D                     = 0;
2480   pcbddc->ksp_D                      = 0;
2481   pcbddc->ksp_R                      = 0;
2482   pcbddc->NeumannBoundaries          = 0;
2483   pcbddc->NeumannBoundariesLocal     = 0;
2484   pcbddc->DirichletBoundaries        = 0;
2485   pcbddc->DirichletBoundariesLocal   = 0;
2486   pcbddc->user_provided_isfordofs    = PETSC_FALSE;
2487   pcbddc->n_ISForDofs                = 0;
2488   pcbddc->n_ISForDofsLocal           = 0;
2489   pcbddc->ISForDofs                  = 0;
2490   pcbddc->ISForDofsLocal             = 0;
2491   pcbddc->ConstraintMatrix           = 0;
2492   pcbddc->use_exact_dirichlet_trick  = PETSC_TRUE;
2493   pcbddc->coarse_loc_to_glob         = 0;
2494   pcbddc->coarsening_ratio           = 8;
2495   pcbddc->coarse_adj_red             = 0;
2496   pcbddc->current_level              = 0;
2497   pcbddc->max_levels                 = 0;
2498   pcbddc->use_coarse_estimates       = PETSC_FALSE;
2499   pcbddc->redistribute_coarse        = 0;
2500   pcbddc->coarse_subassembling       = 0;
2501   pcbddc->coarse_subassembling_init  = 0;
2502 
2503   /* benign subspace trick */
2504   pcbddc->B0_ncol                    = 0;
2505   pcbddc->B0_cols                    = NULL;
2506   pcbddc->B0_vals                    = NULL;
2507   pcbddc->benign_change              = 0;
2508   pcbddc->benign_vec                 = 0;
2509   pcbddc->benign_original_mat        = 0;
2510   pcbddc->benign_sf                  = 0;
2511   pcbddc->benign_p0_lidx             = -1;
2512   pcbddc->benign_p0_gidx             = -1;
2513 
2514   /* create local graph structure */
2515   ierr = PCBDDCGraphCreate(&pcbddc->mat_graph);CHKERRQ(ierr);
2516 
2517   /* scaling */
2518   pcbddc->work_scaling          = 0;
2519   pcbddc->use_deluxe_scaling    = PETSC_FALSE;
2520   pcbddc->faster_deluxe         = PETSC_FALSE;
2521 
2522   /* create sub schurs structure */
2523   ierr = PCBDDCSubSchursCreate(&pcbddc->sub_schurs);CHKERRQ(ierr);
2524   pcbddc->sub_schurs_rebuild     = PETSC_FALSE;
2525   pcbddc->sub_schurs_layers      = -1;
2526   pcbddc->sub_schurs_use_useradj = PETSC_FALSE;
2527 
2528   pcbddc->computed_rowadj = PETSC_FALSE;
2529 
2530   /* adaptivity */
2531   pcbddc->adaptive_threshold      = 0.0;
2532   pcbddc->adaptive_nmax           = 0;
2533   pcbddc->adaptive_nmin           = 0;
2534 
2535   /* function pointers */
2536   pc->ops->apply               = PCApply_BDDC;
2537   pc->ops->applytranspose      = PCApplyTranspose_BDDC;
2538   pc->ops->setup               = PCSetUp_BDDC;
2539   pc->ops->destroy             = PCDestroy_BDDC;
2540   pc->ops->setfromoptions      = PCSetFromOptions_BDDC;
2541   pc->ops->view                = 0;
2542   pc->ops->applyrichardson     = 0;
2543   pc->ops->applysymmetricleft  = 0;
2544   pc->ops->applysymmetricright = 0;
2545   pc->ops->presolve            = PCPreSolve_BDDC;
2546   pc->ops->postsolve           = PCPostSolve_BDDC;
2547 
2548   /* composing function */
2549   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetChangeOfBasisMat_C",PCBDDCSetChangeOfBasisMat_BDDC);CHKERRQ(ierr);
2550   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetPrimalVerticesLocalIS_C",PCBDDCSetPrimalVerticesLocalIS_BDDC);CHKERRQ(ierr);
2551   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetCoarseningRatio_C",PCBDDCSetCoarseningRatio_BDDC);CHKERRQ(ierr);
2552   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetLevel_C",PCBDDCSetLevel_BDDC);CHKERRQ(ierr);
2553   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetUseExactDirichlet_C",PCBDDCSetUseExactDirichlet_BDDC);CHKERRQ(ierr);
2554   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetLevels_C",PCBDDCSetLevels_BDDC);CHKERRQ(ierr);
2555   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetNullSpace_C",PCBDDCSetNullSpace_BDDC);CHKERRQ(ierr);
2556   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDirichletBoundaries_C",PCBDDCSetDirichletBoundaries_BDDC);CHKERRQ(ierr);
2557   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDirichletBoundariesLocal_C",PCBDDCSetDirichletBoundariesLocal_BDDC);CHKERRQ(ierr);
2558   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetNeumannBoundaries_C",PCBDDCSetNeumannBoundaries_BDDC);CHKERRQ(ierr);
2559   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetNeumannBoundariesLocal_C",PCBDDCSetNeumannBoundariesLocal_BDDC);CHKERRQ(ierr);
2560   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetDirichletBoundaries_C",PCBDDCGetDirichletBoundaries_BDDC);CHKERRQ(ierr);
2561   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetDirichletBoundariesLocal_C",PCBDDCGetDirichletBoundariesLocal_BDDC);CHKERRQ(ierr);
2562   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetNeumannBoundaries_C",PCBDDCGetNeumannBoundaries_BDDC);CHKERRQ(ierr);
2563   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCGetNeumannBoundariesLocal_C",PCBDDCGetNeumannBoundariesLocal_BDDC);CHKERRQ(ierr);
2564   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDofsSplitting_C",PCBDDCSetDofsSplitting_BDDC);CHKERRQ(ierr);
2565   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetDofsSplittingLocal_C",PCBDDCSetDofsSplittingLocal_BDDC);CHKERRQ(ierr);
2566   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCSetLocalAdjacencyGraph_C",PCBDDCSetLocalAdjacencyGraph_BDDC);CHKERRQ(ierr);
2567   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCCreateFETIDPOperators_C",PCBDDCCreateFETIDPOperators_BDDC);CHKERRQ(ierr);
2568   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCMatFETIDPGetRHS_C",PCBDDCMatFETIDPGetRHS_BDDC);CHKERRQ(ierr);
2569   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCBDDCMatFETIDPGetSolution_C",PCBDDCMatFETIDPGetSolution_BDDC);CHKERRQ(ierr);
2570   PetscFunctionReturn(0);
2571 }
2572 
2573