xref: /petsc/src/ksp/pc/impls/gamg/agg.c (revision cf1aed2ce99d23e50336629af3ca8cf096900abb)
1 /*
2  GAMG geometric-algebric multiogrid PC - Mark Adams 2011
3  */
4 
5 #include <../src/ksp/pc/impls/gamg/gamg.h>        /*I "petscpc.h" I*/
6 #include <petsc-private/kspimpl.h>
7 
8 #include <petscblaslapack.h>
9 
10 typedef struct {
11   PetscInt  nsmooths;
12   PetscBool sym_graph;
13   PetscBool square_graph;
14 } PC_GAMG_AGG;
15 
16 #undef __FUNCT__
17 #define __FUNCT__ "PCGAMGSetNSmooths"
18 /*@
19    PCGAMGSetNSmooths - Set number of smoothing steps (1 is typical)
20 
21    Not Collective on PC
22 
23    Input Parameters:
24 .  pc - the preconditioner context
25 
26    Options Database Key:
27 .  -pc_gamg_agg_nsmooths
28 
29    Level: intermediate
30 
31    Concepts: Aggregation AMG preconditioner
32 
33 .seealso: ()
34 @*/
35 PetscErrorCode PCGAMGSetNSmooths(PC pc, PetscInt n)
36 {
37   PetscErrorCode ierr;
38 
39   PetscFunctionBegin;
40   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
41   ierr = PetscTryMethod(pc,"PCGAMGSetNSmooths_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
42   PetscFunctionReturn(0);
43 }
44 
45 #undef __FUNCT__
46 #define __FUNCT__ "PCGAMGSetNSmooths_GAMG"
47 PetscErrorCode PCGAMGSetNSmooths_GAMG(PC pc, PetscInt n)
48 {
49   PC_MG       *mg          = (PC_MG*)pc->data;
50   PC_GAMG     *pc_gamg     = (PC_GAMG*)mg->innerctx;
51   PC_GAMG_AGG *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
52 
53   PetscFunctionBegin;
54   pc_gamg_agg->nsmooths = n;
55   PetscFunctionReturn(0);
56 }
57 
58 #undef __FUNCT__
59 #define __FUNCT__ "PCGAMGSetSymGraph"
60 /*@
61    PCGAMGSetSymGraph -
62 
63    Not Collective on PC
64 
65    Input Parameters:
66 .  pc - the preconditioner context
67 
68    Options Database Key:
69 .  -pc_gamg_sym_graph
70 
71    Level: intermediate
72 
73    Concepts: Aggregation AMG preconditioner
74 
75 .seealso: ()
76 @*/
77 PetscErrorCode PCGAMGSetSymGraph(PC pc, PetscBool n)
78 {
79   PetscErrorCode ierr;
80 
81   PetscFunctionBegin;
82   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
83   ierr = PetscTryMethod(pc,"PCGAMGSetSymGraph_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
84   PetscFunctionReturn(0);
85 }
86 
87 #undef __FUNCT__
88 #define __FUNCT__ "PCGAMGSetSymGraph_GAMG"
89 PetscErrorCode PCGAMGSetSymGraph_GAMG(PC pc, PetscBool n)
90 {
91   PC_MG       *mg          = (PC_MG*)pc->data;
92   PC_GAMG     *pc_gamg     = (PC_GAMG*)mg->innerctx;
93   PC_GAMG_AGG *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
94 
95   PetscFunctionBegin;
96   pc_gamg_agg->sym_graph = n;
97   PetscFunctionReturn(0);
98 }
99 
100 #undef __FUNCT__
101 #define __FUNCT__ "PCGAMGSetSquareGraph"
102 /*@
103    PCGAMGSetSquareGraph -
104 
105    Not Collective on PC
106 
107    Input Parameters:
108 .  pc - the preconditioner context
109 
110    Options Database Key:
111 .  -pc_gamg_square_graph
112 
113    Level: intermediate
114 
115    Concepts: Aggregation AMG preconditioner
116 
117 .seealso: ()
118 @*/
119 PetscErrorCode PCGAMGSetSquareGraph(PC pc, PetscBool n)
120 {
121   PetscErrorCode ierr;
122 
123   PetscFunctionBegin;
124   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
125   ierr = PetscTryMethod(pc,"PCGAMGSetSquareGraph_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
126   PetscFunctionReturn(0);
127 }
128 
129 #undef __FUNCT__
130 #define __FUNCT__ "PCGAMGSetSquareGraph_GAMG"
131 PetscErrorCode PCGAMGSetSquareGraph_GAMG(PC pc, PetscBool n)
132 {
133   PC_MG       *mg          = (PC_MG*)pc->data;
134   PC_GAMG     *pc_gamg     = (PC_GAMG*)mg->innerctx;
135   PC_GAMG_AGG *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
136 
137   PetscFunctionBegin;
138   pc_gamg_agg->square_graph = n;
139   PetscFunctionReturn(0);
140 }
141 
142 /* -------------------------------------------------------------------------- */
143 /*
144    PCSetFromOptions_GAMG_AGG
145 
146   Input Parameter:
147    . pc -
148 */
149 #undef __FUNCT__
150 #define __FUNCT__ "PCSetFromOptions_GAMG_AGG"
151 PetscErrorCode PCSetFromOptions_GAMG_AGG(PC pc)
152 {
153   PetscErrorCode ierr;
154   PC_MG          *mg          = (PC_MG*)pc->data;
155   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
156   PC_GAMG_AGG    *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
157   PetscBool      flag;
158 
159   PetscFunctionBegin;
160 
161   ierr = PetscOptionsHead("GAMG-AGG options");CHKERRQ(ierr);
162   {
163     /* -pc_gamg_agg_nsmooths */
164     pc_gamg_agg->nsmooths = 1;
165 
166     ierr = PetscOptionsInt("-pc_gamg_agg_nsmooths",
167                            "smoothing steps for smoothed aggregation, usually 1 (0)",
168                            "PCGAMGSetNSmooths",
169                            pc_gamg_agg->nsmooths,
170                            &pc_gamg_agg->nsmooths,
171                            &flag);CHKERRQ(ierr);
172 
173     /* -pc_gamg_sym_graph */
174     pc_gamg_agg->sym_graph = PETSC_FALSE;
175 
176     ierr = PetscOptionsBool("-pc_gamg_sym_graph",
177                             "Set for asymmetric matrices",
178                             "PCGAMGSetSymGraph",
179                             pc_gamg_agg->sym_graph,
180                             &pc_gamg_agg->sym_graph,
181                             &flag);CHKERRQ(ierr);
182 
183     /* -pc_gamg_square_graph */
184     pc_gamg_agg->square_graph = PETSC_TRUE;
185 
186     ierr = PetscOptionsBool("-pc_gamg_square_graph",
187                             "For faster coarsening and lower coarse grid complexity",
188                             "PCGAMGSetSquareGraph",
189                             pc_gamg_agg->square_graph,
190                             &pc_gamg_agg->square_graph,
191                             &flag);CHKERRQ(ierr);
192   }
193   ierr = PetscOptionsTail();CHKERRQ(ierr);
194   PetscFunctionReturn(0);
195 }
196 
197 /* -------------------------------------------------------------------------- */
198 /*
199    PCDestroy_AGG
200 
201   Input Parameter:
202    . pc -
203 */
204 #undef __FUNCT__
205 #define __FUNCT__ "PCDestroy_GAMG_AGG"
206 PetscErrorCode PCDestroy_GAMG_AGG(PC pc)
207 {
208   PetscErrorCode ierr;
209   PC_MG          *mg          = (PC_MG*)pc->data;
210   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
211 
212   PetscFunctionBegin;
213   ierr = PetscFree(pc_gamg->subctx);CHKERRQ(ierr);
214   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCSetCoordinates_C",NULL);CHKERRQ(ierr);
215   PetscFunctionReturn(0);
216 }
217 
218 /* -------------------------------------------------------------------------- */
219 /*
220    PCSetCoordinates_AGG
221      - collective
222 
223    Input Parameter:
224    . pc - the preconditioner context
225    . ndm - dimesion of data (used for dof/vertex for Stokes)
226    . a_nloc - number of vertices local
227    . coords - [a_nloc][ndm] - interleaved coordinate data: {x_0, y_0, z_0, x_1, y_1, ...}
228 */
229 
230 #undef __FUNCT__
231 #define __FUNCT__ "PCSetCoordinates_AGG"
232 static PetscErrorCode PCSetCoordinates_AGG(PC pc, PetscInt ndm, PetscInt a_nloc, PetscReal *coords)
233 {
234   PC_MG          *mg      = (PC_MG*)pc->data;
235   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
236   PetscErrorCode ierr;
237   PetscInt       arrsz,kk,ii,jj,nloc,ndatarows,ndf;
238   Mat            mat = pc->pmat;
239 
240   PetscFunctionBegin;
241   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
242   PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
243   nloc = a_nloc;
244 
245   /* SA: null space vectors */
246   ierr = MatGetBlockSize(mat, &ndf);CHKERRQ(ierr); /* this does not work for Stokes */
247   if (coords && ndf==1) pc_gamg->data_cell_cols = 1; /* scalar w/ coords and SA (not needed) */
248   else if (coords) {
249     if (ndm > ndf) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"degrees of motion %d > block size %d",ndm,ndf);
250     pc_gamg->data_cell_cols = (ndm==2 ? 3 : 6); /* displacement elasticity */
251     if (ndm != ndf) {
252       if (pc_gamg->data_cell_cols != ndf) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Don't know how to create null space for ndm=%d, ndf=%d.  Use MatSetNearNullSpace.",ndm,ndf);
253     }
254   } else pc_gamg->data_cell_cols = ndf; /* no data, force SA with constant null space vectors */
255   pc_gamg->data_cell_rows = ndatarows = ndf;
256   if (pc_gamg->data_cell_cols <= 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"pc_gamg->data_cell_cols %D <= 0",pc_gamg->data_cell_cols);
257   arrsz = nloc*pc_gamg->data_cell_rows*pc_gamg->data_cell_cols;
258 
259   /* create data - syntactic sugar that should be refactored at some point */
260   if (pc_gamg->data==0 || (pc_gamg->data_sz != arrsz)) {
261     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
262     ierr = PetscMalloc1((arrsz+1), &pc_gamg->data);CHKERRQ(ierr);
263   }
264   /* copy data in - column oriented */
265   for (kk=0; kk<nloc; kk++) {
266     const PetscInt M     = nloc*pc_gamg->data_cell_rows; /* stride into data */
267     PetscReal      *data = &pc_gamg->data[kk*ndatarows]; /* start of cell */
268     if (pc_gamg->data_cell_cols==1) *data = 1.0;
269     else {
270       /* translational modes */
271       for (ii=0;ii<ndatarows;ii++) {
272         for (jj=0;jj<ndatarows;jj++) {
273           if (ii==jj)data[ii*M + jj] = 1.0;
274           else data[ii*M + jj] = 0.0;
275         }
276       }
277 
278       /* rotational modes */
279       if (coords) {
280         if (ndm == 2) {
281           data   += 2*M;
282           data[0] = -coords[2*kk+1];
283           data[1] =  coords[2*kk];
284         } else {
285           data   += 3*M;
286           data[0] = 0.0;             data[M+0] =  coords[3*kk+2]; data[2*M+0] = -coords[3*kk+1];
287           data[1] = -coords[3*kk+2]; data[M+1] = 0.0;             data[2*M+1] =  coords[3*kk];
288           data[2] =  coords[3*kk+1]; data[M+2] = -coords[3*kk];   data[2*M+2] = 0.0;
289         }
290       }
291     }
292   }
293 
294   pc_gamg->data_sz = arrsz;
295   PetscFunctionReturn(0);
296 }
297 
298 typedef PetscInt NState;
299 static const NState NOT_DONE=-2;
300 static const NState DELETED =-1;
301 static const NState REMOVED =-3;
302 #define IS_SELECTED(s) (s!=DELETED && s!=NOT_DONE && s!=REMOVED)
303 
304 /* -------------------------------------------------------------------------- */
305 /*
306    smoothAggs - greedy grab of with G1 (unsquared graph) -- AIJ specific
307      - AGG-MG specific: clears singletons out of 'selected_2'
308 
309    Input Parameter:
310    . Gmat_2 - glabal matrix of graph (data not defined)
311    . Gmat_1 - base graph to grab with
312    Input/Output Parameter:
313    . aggs_2 - linked list of aggs with gids)
314 */
315 #undef __FUNCT__
316 #define __FUNCT__ "smoothAggs"
317 static PetscErrorCode smoothAggs(const Mat Gmat_2, /* base (squared) graph */
318                                  const Mat Gmat_1,  /* base graph */
319                                  /* const IS selected_2, [nselected local] selected vertices */
320                                  PetscCoarsenData *aggs_2)  /* [nselected local] global ID of aggregate */
321 {
322   PetscErrorCode ierr;
323   PetscBool      isMPI;
324   Mat_SeqAIJ     *matA_1, *matB_1=0, *matA_2, *matB_2=0;
325   MPI_Comm       comm;
326   PetscMPIInt    rank,size;
327   PetscInt       lid,*ii,*idx,ix,Iend,my0,kk,n,j;
328   Mat_MPIAIJ     *mpimat_2 = 0, *mpimat_1=0;
329   const PetscInt nloc      = Gmat_2->rmap->n;
330   PetscScalar    *cpcol_1_state,*cpcol_2_state,*cpcol_2_par_orig,*lid_parent_gid;
331   PetscInt       *lid_cprowID_1;
332   NState         *lid_state;
333   Vec            ghost_par_orig2;
334 
335   PetscFunctionBegin;
336   ierr = PetscObjectGetComm((PetscObject)Gmat_2,&comm);CHKERRQ(ierr);
337   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
338   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
339   ierr = MatGetOwnershipRange(Gmat_1,&my0,&Iend);CHKERRQ(ierr);
340 
341   if (PETSC_FALSE) {
342     PetscViewer viewer; char fname[32]; static int llev=0;
343     sprintf(fname,"Gmat2_%d.m",llev++);
344     PetscViewerASCIIOpen(comm,fname,&viewer);
345     ierr = PetscViewerSetFormat(viewer, PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
346     ierr = MatView(Gmat_2, viewer);CHKERRQ(ierr);
347     ierr = PetscViewerDestroy(&viewer);
348   }
349 
350   /* get submatrices */
351   ierr = PetscObjectTypeCompare((PetscObject)Gmat_1, MATMPIAIJ, &isMPI);CHKERRQ(ierr);
352   if (isMPI) {
353     /* grab matrix objects */
354     mpimat_2 = (Mat_MPIAIJ*)Gmat_2->data;
355     mpimat_1 = (Mat_MPIAIJ*)Gmat_1->data;
356     matA_1   = (Mat_SeqAIJ*)mpimat_1->A->data;
357     matB_1   = (Mat_SeqAIJ*)mpimat_1->B->data;
358     matA_2   = (Mat_SeqAIJ*)mpimat_2->A->data;
359     matB_2   = (Mat_SeqAIJ*)mpimat_2->B->data;
360 
361     /* force compressed row storage for B matrix in AuxMat */
362     ierr = MatCheckCompressedRow(mpimat_1->B,matB_1->nonzerorowcnt,&matB_1->compressedrow,matB_1->i,Gmat_1->rmap->n,-1.0);CHKERRQ(ierr);
363 
364     ierr = PetscMalloc1(nloc, &lid_cprowID_1);CHKERRQ(ierr);
365     for (lid = 0; lid < nloc; lid++) lid_cprowID_1[lid] = -1;
366     for (ix=0; ix<matB_1->compressedrow.nrows; ix++) {
367       PetscInt lid = matB_1->compressedrow.rindex[ix];
368       lid_cprowID_1[lid] = ix;
369     }
370   } else {
371     matA_1        = (Mat_SeqAIJ*)Gmat_1->data;
372     matA_2        = (Mat_SeqAIJ*)Gmat_2->data;
373     lid_cprowID_1 = NULL;
374   }
375   if (nloc>0) {
376     if (!(matA_1 && !matA_1->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matA_1 && !matA_1->compressedrow.use)");
377     if (!(matB_1==0 || matB_1->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matB_1==0 || matB_1->compressedrow.use)");
378     if (!(matA_2 && !matA_2->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matA_2 && !matA_2->compressedrow.use)");
379     if (!(matB_2==0 || matB_2->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matB_2==0 || matB_2->compressedrow.use)");
380   }
381   /* get state of locals and selected gid for deleted */
382   ierr = PetscMalloc1(nloc, &lid_state);CHKERRQ(ierr);
383   ierr = PetscMalloc1(nloc, &lid_parent_gid);CHKERRQ(ierr);
384   for (lid = 0; lid < nloc; lid++) {
385     lid_parent_gid[lid] = -1.0;
386     lid_state[lid]      = DELETED;
387   }
388 
389   /* set lid_state */
390   for (lid = 0; lid < nloc; lid++) {
391     PetscCDPos pos;
392     ierr = PetscCDGetHeadPos(aggs_2,lid,&pos);CHKERRQ(ierr);
393     if (pos) {
394       PetscInt gid1;
395 
396       ierr = PetscLLNGetID(pos, &gid1);CHKERRQ(ierr);
397       if (gid1 != lid+my0) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"gid1 %D != lid %D + my0 %D",gid1,lid,my0);
398       lid_state[lid] = gid1;
399     }
400   }
401 
402   /* map local to selected local, DELETED means a ghost owns it */
403   for (lid=kk=0; lid<nloc; lid++) {
404     NState state = lid_state[lid];
405     if (IS_SELECTED(state)) {
406       PetscCDPos pos;
407       ierr = PetscCDGetHeadPos(aggs_2,lid,&pos);CHKERRQ(ierr);
408       while (pos) {
409         PetscInt gid1;
410         ierr = PetscLLNGetID(pos, &gid1);CHKERRQ(ierr);
411         ierr = PetscCDGetNextPos(aggs_2,lid,&pos);CHKERRQ(ierr);
412 
413         if (gid1 >= my0 && gid1 < Iend) lid_parent_gid[gid1-my0] = (PetscScalar)(lid + my0);
414       }
415     }
416   }
417   /* get 'cpcol_1/2_state' & cpcol_2_par_orig - uses mpimat_1/2->lvec for temp space */
418   if (isMPI) {
419     Vec tempVec;
420     /* get 'cpcol_1_state' */
421     ierr = MatGetVecs(Gmat_1, &tempVec, 0);CHKERRQ(ierr);
422     for (kk=0,j=my0; kk<nloc; kk++,j++) {
423       PetscScalar v = (PetscScalar)lid_state[kk];
424       ierr = VecSetValues(tempVec, 1, &j, &v, INSERT_VALUES);CHKERRQ(ierr);
425     }
426     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
427     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
428     ierr = VecScatterBegin(mpimat_1->Mvctx,tempVec, mpimat_1->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
429     ierr =   VecScatterEnd(mpimat_1->Mvctx,tempVec, mpimat_1->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
430     ierr = VecGetArray(mpimat_1->lvec, &cpcol_1_state);CHKERRQ(ierr);
431     /* get 'cpcol_2_state' */
432     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, mpimat_2->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
433     ierr =   VecScatterEnd(mpimat_2->Mvctx,tempVec, mpimat_2->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
434     ierr = VecGetArray(mpimat_2->lvec, &cpcol_2_state);CHKERRQ(ierr);
435     /* get 'cpcol_2_par_orig' */
436     for (kk=0,j=my0; kk<nloc; kk++,j++) {
437       PetscScalar v = (PetscScalar)lid_parent_gid[kk];
438       ierr = VecSetValues(tempVec, 1, &j, &v, INSERT_VALUES);CHKERRQ(ierr);
439     }
440     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
441     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
442     ierr = VecDuplicate(mpimat_2->lvec, &ghost_par_orig2);CHKERRQ(ierr);
443     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, ghost_par_orig2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
444     ierr =   VecScatterEnd(mpimat_2->Mvctx,tempVec, ghost_par_orig2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
445     ierr = VecGetArray(ghost_par_orig2, &cpcol_2_par_orig);CHKERRQ(ierr);
446 
447     ierr = VecDestroy(&tempVec);CHKERRQ(ierr);
448   } /* ismpi */
449 
450   /* doit */
451   for (lid=0; lid<nloc; lid++) {
452     NState state = lid_state[lid];
453     if (IS_SELECTED(state)) {
454       /* steal locals */
455       ii  = matA_1->i; n = ii[lid+1] - ii[lid];
456       idx = matA_1->j + ii[lid];
457       for (j=0; j<n; j++) {
458         PetscInt lidj   = idx[j], sgid;
459         NState   statej = lid_state[lidj];
460         if (statej==DELETED && (sgid=(PetscInt)PetscRealPart(lid_parent_gid[lidj])) != lid+my0) { /* steal local */
461           lid_parent_gid[lidj] = (PetscScalar)(lid+my0); /* send this if sgid is not local */
462           if (sgid >= my0 && sgid < Iend) {       /* I'm stealing this local from a local sgid */
463             PetscInt   hav=0,slid=sgid-my0,gidj=lidj+my0;
464             PetscCDPos pos,last=NULL;
465             /* looking for local from local so id_llist_2 works */
466             ierr = PetscCDGetHeadPos(aggs_2,slid,&pos);CHKERRQ(ierr);
467             while (pos) {
468               PetscInt gid;
469               ierr = PetscLLNGetID(pos, &gid);CHKERRQ(ierr);
470               if (gid == gidj) {
471                 if (!last) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"last cannot be null");
472                 ierr = PetscCDRemoveNextNode(aggs_2, slid, last);CHKERRQ(ierr);
473                 ierr = PetscCDAppendNode(aggs_2, lid, pos);CHKERRQ(ierr);
474                 hav  = 1;
475                 break;
476               } else last = pos;
477 
478               ierr = PetscCDGetNextPos(aggs_2,slid,&pos);CHKERRQ(ierr);
479             }
480             if (hav!=1) {
481               if (!hav) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"failed to find adj in 'selected' lists - structurally unsymmetric matrix");
482               SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"found node %d times???",hav);
483             }
484           } else {            /* I'm stealing this local, owned by a ghost */
485             if (sgid != -1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Have un-symmetric graph (apparently). Use '-pc_gamg_sym_graph true' to symetrize the graph or '-pc_gamg_threshold 0.0' if the matrix is structurally symmetric.");
486             ierr = PetscCDAppendID(aggs_2, lid, lidj+my0);CHKERRQ(ierr);
487           }
488         }
489       } /* local neighbors */
490     } else if (state == DELETED && lid_cprowID_1) {
491       PetscInt sgidold = (PetscInt)PetscRealPart(lid_parent_gid[lid]);
492       /* see if I have a selected ghost neighbor that will steal me */
493       if ((ix=lid_cprowID_1[lid]) != -1) {
494         ii  = matB_1->compressedrow.i; n = ii[ix+1] - ii[ix];
495         idx = matB_1->j + ii[ix];
496         for (j=0; j<n; j++) {
497           PetscInt cpid   = idx[j];
498           NState   statej = (NState)PetscRealPart(cpcol_1_state[cpid]);
499           if (IS_SELECTED(statej) && sgidold != (PetscInt)statej) { /* ghost will steal this, remove from my list */
500             lid_parent_gid[lid] = (PetscScalar)statej; /* send who selected */
501             if (sgidold>=my0 && sgidold<Iend) { /* this was mine */
502               PetscInt   hav=0,oldslidj=sgidold-my0;
503               PetscCDPos pos,last=NULL;
504               /* remove from 'oldslidj' list */
505               ierr = PetscCDGetHeadPos(aggs_2,oldslidj,&pos);CHKERRQ(ierr);
506               while (pos) {
507                 PetscInt gid;
508                 ierr = PetscLLNGetID(pos, &gid);CHKERRQ(ierr);
509                 if (lid+my0 == gid) {
510                   /* id_llist_2[lastid] = id_llist_2[flid];   /\* remove lid from oldslidj list *\/ */
511                   if (!last) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"last cannot be null");
512                   ierr = PetscCDRemoveNextNode(aggs_2, oldslidj, last);CHKERRQ(ierr);
513                   /* ghost (PetscScalar)statej will add this later */
514                   hav = 1;
515                   break;
516                 } else last = pos;
517 
518                 ierr = PetscCDGetNextPos(aggs_2,oldslidj,&pos);CHKERRQ(ierr);
519               }
520               if (hav!=1) {
521                 if (hav==0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"failed to find adj in 'selected' lists - structurally unsymmetric matrix");
522                 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"found node %d times???",hav);
523               }
524             } else {
525               /* ghosts remove this later */
526             }
527           }
528         }
529       }
530     } /* selected/deleted */
531   } /* node loop */
532 
533   if (isMPI) {
534     PetscScalar   *cpcol_2_parent,*cpcol_2_gid;
535     Vec           tempVec,ghostgids2,ghostparents2;
536     PetscInt      cpid,nghost_2;
537     GAMGHashTable gid_cpid;
538 
539     ierr = VecGetSize(mpimat_2->lvec, &nghost_2);CHKERRQ(ierr);
540     ierr = MatGetVecs(Gmat_2, &tempVec, 0);CHKERRQ(ierr);
541 
542     /* get 'cpcol_2_parent' */
543     for (kk=0,j=my0; kk<nloc; kk++,j++) {
544       ierr = VecSetValues(tempVec, 1, &j, &lid_parent_gid[kk], INSERT_VALUES);CHKERRQ(ierr);
545     }
546     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
547     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
548     ierr = VecDuplicate(mpimat_2->lvec, &ghostparents2);CHKERRQ(ierr);
549     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, ghostparents2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
550     ierr = VecScatterEnd(mpimat_2->Mvctx,tempVec, ghostparents2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
551     ierr = VecGetArray(ghostparents2, &cpcol_2_parent);CHKERRQ(ierr);
552 
553     /* get 'cpcol_2_gid' */
554     for (kk=0,j=my0; kk<nloc; kk++,j++) {
555       PetscScalar v = (PetscScalar)j;
556       ierr = VecSetValues(tempVec, 1, &j, &v, INSERT_VALUES);CHKERRQ(ierr);
557     }
558     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
559     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
560     ierr = VecDuplicate(mpimat_2->lvec, &ghostgids2);CHKERRQ(ierr);
561     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, ghostgids2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
562     ierr =   VecScatterEnd(mpimat_2->Mvctx,tempVec, ghostgids2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
563     ierr = VecGetArray(ghostgids2, &cpcol_2_gid);CHKERRQ(ierr);
564 
565     ierr = VecDestroy(&tempVec);CHKERRQ(ierr);
566 
567     /* look for deleted ghosts and add to table */
568     ierr = GAMGTableCreate(2*nghost_2+1, &gid_cpid);CHKERRQ(ierr);
569     for (cpid = 0; cpid < nghost_2; cpid++) {
570       NState state = (NState)PetscRealPart(cpcol_2_state[cpid]);
571       if (state==DELETED) {
572         PetscInt sgid_new = (PetscInt)PetscRealPart(cpcol_2_parent[cpid]);
573         PetscInt sgid_old = (PetscInt)PetscRealPart(cpcol_2_par_orig[cpid]);
574         if (sgid_old == -1 && sgid_new != -1) {
575           PetscInt gid = (PetscInt)PetscRealPart(cpcol_2_gid[cpid]);
576           ierr = GAMGTableAdd(&gid_cpid, gid, cpid);CHKERRQ(ierr);
577         }
578       }
579     }
580 
581     /* look for deleted ghosts and see if they moved - remove it */
582     for (lid=0; lid<nloc; lid++) {
583       NState state = lid_state[lid];
584       if (IS_SELECTED(state)) {
585         PetscCDPos pos,last=NULL;
586         /* look for deleted ghosts and see if they moved */
587         ierr = PetscCDGetHeadPos(aggs_2,lid,&pos);CHKERRQ(ierr);
588         while (pos) {
589           PetscInt gid;
590           ierr = PetscLLNGetID(pos, &gid);CHKERRQ(ierr);
591 
592           if (gid < my0 || gid >= Iend) {
593             ierr = GAMGTableFind(&gid_cpid, gid, &cpid);CHKERRQ(ierr);
594             if (cpid != -1) {
595               /* a moved ghost - */
596               /* id_llist_2[lastid] = id_llist_2[flid];    /\* remove 'flid' from list *\/ */
597               ierr = PetscCDRemoveNextNode(aggs_2, lid, last);CHKERRQ(ierr);
598             } else last = pos;
599           } else last = pos;
600 
601           ierr = PetscCDGetNextPos(aggs_2,lid,&pos);CHKERRQ(ierr);
602         } /* loop over list of deleted */
603       } /* selected */
604     }
605     ierr = GAMGTableDestroy(&gid_cpid);CHKERRQ(ierr);
606 
607     /* look at ghosts, see if they changed - and it */
608     for (cpid = 0; cpid < nghost_2; cpid++) {
609       PetscInt sgid_new = (PetscInt)PetscRealPart(cpcol_2_parent[cpid]);
610       if (sgid_new >= my0 && sgid_new < Iend) { /* this is mine */
611         PetscInt   gid     = (PetscInt)PetscRealPart(cpcol_2_gid[cpid]);
612         PetscInt   slid_new=sgid_new-my0,hav=0;
613         PetscCDPos pos;
614         /* search for this gid to see if I have it */
615         ierr = PetscCDGetHeadPos(aggs_2,slid_new,&pos);CHKERRQ(ierr);
616         while (pos) {
617           PetscInt gidj;
618           ierr = PetscLLNGetID(pos, &gidj);CHKERRQ(ierr);
619           ierr = PetscCDGetNextPos(aggs_2,slid_new,&pos);CHKERRQ(ierr);
620 
621           if (gidj == gid) { hav = 1; break; }
622         }
623         if (hav != 1) {
624           /* insert 'flidj' into head of llist */
625           ierr = PetscCDAppendID(aggs_2, slid_new, gid);CHKERRQ(ierr);
626         }
627       }
628     }
629 
630     ierr = VecRestoreArray(mpimat_1->lvec, &cpcol_1_state);CHKERRQ(ierr);
631     ierr = VecRestoreArray(mpimat_2->lvec, &cpcol_2_state);CHKERRQ(ierr);
632     ierr = VecRestoreArray(ghostparents2, &cpcol_2_parent);CHKERRQ(ierr);
633     ierr = VecRestoreArray(ghostgids2, &cpcol_2_gid);CHKERRQ(ierr);
634     ierr = PetscFree(lid_cprowID_1);CHKERRQ(ierr);
635     ierr = VecDestroy(&ghostgids2);CHKERRQ(ierr);
636     ierr = VecDestroy(&ghostparents2);CHKERRQ(ierr);
637     ierr = VecDestroy(&ghost_par_orig2);CHKERRQ(ierr);
638   }
639 
640   ierr = PetscFree(lid_parent_gid);CHKERRQ(ierr);
641   ierr = PetscFree(lid_state);CHKERRQ(ierr);
642   PetscFunctionReturn(0);
643 }
644 
645 /* -------------------------------------------------------------------------- */
646 /*
647    PCSetData_AGG - called if data is not set with PCSetCoordinates.
648       Looks in Mat for near null space.
649       Does not work for Stokes
650 
651   Input Parameter:
652    . pc -
653    . a_A - matrix to get (near) null space out of.
654 */
655 #undef __FUNCT__
656 #define __FUNCT__ "PCSetData_AGG"
657 PetscErrorCode PCSetData_AGG(PC pc, Mat a_A)
658 {
659   PetscErrorCode ierr;
660   PC_MG          *mg      = (PC_MG*)pc->data;
661   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
662   MatNullSpace   mnull;
663 
664   PetscFunctionBegin;
665   ierr = MatGetNearNullSpace(a_A, &mnull);CHKERRQ(ierr);
666   if (!mnull) {
667     PetscInt bs,NN,MM;
668     ierr = MatGetBlockSize(a_A, &bs);CHKERRQ(ierr);
669     ierr = MatGetLocalSize(a_A, &MM, &NN);CHKERRQ(ierr);
670     if (MM % bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MM %D must be divisible by bs %D",MM,bs);
671     ierr = PCSetCoordinates_AGG(pc, bs, MM/bs, NULL);CHKERRQ(ierr);
672   } else {
673     PetscReal *nullvec;
674     PetscBool has_const;
675     PetscInt  i,j,mlocal,nvec,bs;
676     const Vec *vecs; const PetscScalar *v;
677     ierr = MatGetLocalSize(a_A,&mlocal,NULL);CHKERRQ(ierr);
678     ierr = MatNullSpaceGetVecs(mnull, &has_const, &nvec, &vecs);CHKERRQ(ierr);
679     pc_gamg->data_sz = (nvec+!!has_const)*mlocal;
680     ierr = PetscMalloc1((nvec+!!has_const)*mlocal,&nullvec);CHKERRQ(ierr);
681     if (has_const) for (i=0; i<mlocal; i++) nullvec[i] = 1.0;
682     for (i=0; i<nvec; i++) {
683       ierr = VecGetArrayRead(vecs[i],&v);CHKERRQ(ierr);
684       for (j=0; j<mlocal; j++) nullvec[(i+!!has_const)*mlocal + j] = PetscRealPart(v[j]);
685       ierr = VecRestoreArrayRead(vecs[i],&v);CHKERRQ(ierr);
686     }
687     pc_gamg->data           = nullvec;
688     pc_gamg->data_cell_cols = (nvec+!!has_const);
689 
690     ierr = MatGetBlockSize(a_A, &bs);CHKERRQ(ierr);
691 
692     pc_gamg->data_cell_rows = bs;
693   }
694   PetscFunctionReturn(0);
695 }
696 
697 /* -------------------------------------------------------------------------- */
698 /*
699  formProl0
700 
701    Input Parameter:
702    . agg_llists - list of arrays with aggregates
703    . bs - block size
704    . nSAvec - column bs of new P
705    . my0crs - global index of start of locals
706    . data_stride - bs*(nloc nodes + ghost nodes)
707    . data_in[data_stride*nSAvec] - local data on fine grid
708    . flid_fgid[data_stride/bs] - make local to global IDs, includes ghosts in 'locals_llist'
709   Output Parameter:
710    . a_data_out - in with fine grid data (w/ghosts), out with coarse grid data
711    . a_Prol - prolongation operator
712 */
713 #undef __FUNCT__
714 #define __FUNCT__ "formProl0"
715 static PetscErrorCode formProl0(const PetscCoarsenData *agg_llists, /* list from selected vertices of aggregate unselected vertices */
716                                 const PetscInt bs,          /* (row) block size */
717                                 const PetscInt nSAvec,      /* column bs */
718                                 const PetscInt my0crs,      /* global index of start of locals */
719                                 const PetscInt data_stride, /* (nloc+nghost)*bs */
720                                 PetscReal      data_in[],   /* [data_stride][nSAvec] */
721                                 const PetscInt flid_fgid[], /* [data_stride/bs] */
722                                 PetscReal **a_data_out,
723                                 Mat a_Prol) /* prolongation operator (output)*/
724 {
725   PetscErrorCode ierr;
726   PetscInt       Istart,my0,Iend,nloc,clid,flid,aggID,kk,jj,ii,mm,ndone,nSelected,minsz,nghosts,out_data_stride;
727   MPI_Comm       comm;
728   PetscMPIInt    rank, size;
729   PetscReal      *out_data;
730   PetscCDPos     pos;
731   GAMGHashTable  fgid_flid;
732 
733 /* #define OUT_AGGS */
734 #if defined(OUT_AGGS)
735   static PetscInt llev = 0; char fname[32]; FILE *file = NULL; PetscInt pM;
736 #endif
737 
738   PetscFunctionBegin;
739   ierr = PetscObjectGetComm((PetscObject)a_Prol,&comm);CHKERRQ(ierr);
740   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
741   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
742   ierr = MatGetOwnershipRange(a_Prol, &Istart, &Iend);CHKERRQ(ierr);
743   nloc = (Iend-Istart)/bs; my0 = Istart/bs;
744   if ((Iend-Istart) % bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Iend %D - Istart %d must be divisible by bs %D",Iend,Istart,bs);
745   Iend   /= bs;
746   nghosts = data_stride/bs - nloc;
747 
748   ierr = GAMGTableCreate(2*nghosts+1, &fgid_flid);CHKERRQ(ierr);
749   for (kk=0; kk<nghosts; kk++) {
750     ierr = GAMGTableAdd(&fgid_flid, flid_fgid[nloc+kk], nloc+kk);CHKERRQ(ierr);
751   }
752 
753 #if defined(OUT_AGGS)
754   sprintf(fname,"aggs_%d_%d.m",llev++,rank);
755   if (llev==1) file = fopen(fname,"w");
756   MatGetSize(a_Prol, &pM, &jj);
757 #endif
758 
759   /* count selected -- same as number of cols of P */
760   for (nSelected=mm=0; mm<nloc; mm++) {
761     PetscBool ise;
762     ierr = PetscCDEmptyAt(agg_llists, mm, &ise);CHKERRQ(ierr);
763     if (!ise) nSelected++;
764   }
765   ierr = MatGetOwnershipRangeColumn(a_Prol, &ii, &jj);CHKERRQ(ierr);
766   if ((ii/nSAvec) != my0crs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"ii %D /nSAvec %D  != my0crs %D",ii,nSAvec,my0crs);
767   if (nSelected != (jj-ii)/nSAvec) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB,"nSelected %D != (jj %D - ii %D)/nSAvec %D",nSelected,jj,ii,nSAvec);
768 
769   /* aloc space for coarse point data (output) */
770   out_data_stride = nSelected*nSAvec;
771 
772   ierr = PetscMalloc1(out_data_stride*nSAvec, &out_data);CHKERRQ(ierr);
773   for (ii=0;ii<out_data_stride*nSAvec;ii++) out_data[ii]=PETSC_MAX_REAL;
774   *a_data_out = out_data; /* output - stride nSelected*nSAvec */
775 
776   /* find points and set prolongation */
777   minsz = 100;
778   ndone = 0;
779   for (mm = clid = 0; mm < nloc; mm++) {
780     ierr = PetscCDSizeAt(agg_llists, mm, &jj);CHKERRQ(ierr);
781     if (jj > 0) {
782       const PetscInt lid = mm, cgid = my0crs + clid;
783       PetscInt       cids[100]; /* max bs */
784       PetscBLASInt   asz  =jj,M=asz*bs,N=nSAvec,INFO;
785       PetscBLASInt   Mdata=M+((N-M>0) ? N-M : 0),LDA=Mdata,LWORK=N*bs;
786       PetscScalar    *qqc,*qqr,*TAU,*WORK;
787       PetscInt       *fids;
788       PetscReal      *data;
789       /* count agg */
790       if (asz<minsz) minsz = asz;
791 
792       /* get block */
793       ierr = PetscMalloc1((Mdata*N), &qqc);CHKERRQ(ierr);
794       ierr = PetscMalloc1((M*N), &qqr);CHKERRQ(ierr);
795       ierr = PetscMalloc1(N, &TAU);CHKERRQ(ierr);
796       ierr = PetscMalloc1(LWORK, &WORK);CHKERRQ(ierr);
797       ierr = PetscMalloc1(M, &fids);CHKERRQ(ierr);
798 
799       aggID = 0;
800       ierr  = PetscCDGetHeadPos(agg_llists,lid,&pos);CHKERRQ(ierr);
801       while (pos) {
802         PetscInt gid1;
803         ierr = PetscLLNGetID(pos, &gid1);CHKERRQ(ierr);
804         ierr = PetscCDGetNextPos(agg_llists,lid,&pos);CHKERRQ(ierr);
805 
806         if (gid1 >= my0 && gid1 < Iend) flid = gid1 - my0;
807         else {
808           ierr = GAMGTableFind(&fgid_flid, gid1, &flid);CHKERRQ(ierr);
809           if (flid < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Cannot find gid1 in table");
810         }
811         /* copy in B_i matrix - column oriented */
812         data = &data_in[flid*bs];
813         for (kk = ii = 0; ii < bs; ii++) {
814           for (jj = 0; jj < N; jj++) {
815             PetscReal d = data[jj*data_stride + ii];
816             qqc[jj*Mdata + aggID*bs + ii] = d;
817           }
818         }
819 #if defined(OUT_AGGS)
820         if (llev==1) {
821           char     str[] = "plot(%e,%e,'r*'), hold on,\n", col[] = "rgbkmc", sim[] = "*os+h>d<vx^";
822           PetscInt MM,pi,pj;
823           str[12] = col[(clid+17*rank)%6]; str[13] = sim[(clid+17*rank)%11];
824           MM      = (PetscInt)(PetscSqrtReal((PetscReal)pM));
825           pj      = gid1/MM; pi = gid1%MM;
826           fprintf(file,str,(double)pi,(double)pj);
827           /* fprintf(file,str,data[2*data_stride+1],-data[2*data_stride]); */
828         }
829 #endif
830         /* set fine IDs */
831         for (kk=0; kk<bs; kk++) fids[aggID*bs + kk] = flid_fgid[flid]*bs + kk;
832 
833         aggID++;
834       }
835 
836       /* pad with zeros */
837       for (ii = asz*bs; ii < Mdata; ii++) {
838         for (jj = 0; jj < N; jj++, kk++) {
839           qqc[jj*Mdata + ii] = .0;
840         }
841       }
842 
843       ndone += aggID;
844       /* QR */
845       ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
846       PetscStackCallBLAS("LAPACKgeqrf",LAPACKgeqrf_(&Mdata, &N, qqc, &LDA, TAU, WORK, &LWORK, &INFO));
847       ierr = PetscFPTrapPop();CHKERRQ(ierr);
848       if (INFO != 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"xGEQRF error");
849       /* get R - column oriented - output B_{i+1} */
850       {
851         PetscReal *data = &out_data[clid*nSAvec];
852         for (jj = 0; jj < nSAvec; jj++) {
853           for (ii = 0; ii < nSAvec; ii++) {
854             if (data[jj*out_data_stride + ii] != PETSC_MAX_REAL) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"data[jj*out_data_stride + ii] != %e",PETSC_MAX_REAL);
855            if (ii <= jj) data[jj*out_data_stride + ii] = PetscRealPart(qqc[jj*Mdata + ii]);
856            else data[jj*out_data_stride + ii] = 0.;
857           }
858         }
859       }
860 
861       /* get Q - row oriented */
862       PetscStackCallBLAS("LAPACKungqr",LAPACKungqr_(&Mdata, &N, &N, qqc, &LDA, TAU, WORK, &LWORK, &INFO));
863       if (INFO != 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"xORGQR error arg %d",-INFO);
864 
865       for (ii = 0; ii < M; ii++) {
866         for (jj = 0; jj < N; jj++) {
867           qqr[N*ii + jj] = qqc[jj*Mdata + ii];
868         }
869       }
870 
871       /* add diagonal block of P0 */
872       for (kk=0; kk<N; kk++) {
873         cids[kk] = N*cgid + kk; /* global col IDs in P0 */
874       }
875       ierr = MatSetValues(a_Prol,M,fids,N,cids,qqr,INSERT_VALUES);CHKERRQ(ierr);
876 
877       ierr = PetscFree(qqc);CHKERRQ(ierr);
878       ierr = PetscFree(qqr);CHKERRQ(ierr);
879       ierr = PetscFree(TAU);CHKERRQ(ierr);
880       ierr = PetscFree(WORK);CHKERRQ(ierr);
881       ierr = PetscFree(fids);CHKERRQ(ierr);
882       clid++;
883     } /* coarse agg */
884   } /* for all fine nodes */
885   ierr = MatAssemblyBegin(a_Prol,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
886   ierr = MatAssemblyEnd(a_Prol,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
887 
888 /* ierr = MPI_Allreduce(&ndone, &ii, 1, MPIU_INT, MPIU_SUM, comm); */
889 /* MatGetSize(a_Prol, &kk, &jj); */
890 /* ierr = MPI_Allreduce(&minsz, &jj, 1, MPIU_INT, MPIU_MIN, comm); */
891 /* PetscPrintf(comm," **** [%d]%s %d total done, %d nodes (%d local done), min agg. size = %d\n",rank,__FUNCT__,ii,kk/bs,ndone,jj); */
892 
893 #if defined(OUT_AGGS)
894   if (llev==1) fclose(file);
895 #endif
896   ierr = GAMGTableDestroy(&fgid_flid);CHKERRQ(ierr);
897   PetscFunctionReturn(0);
898 }
899 
900 /* -------------------------------------------------------------------------- */
901 /*
902    PCGAMGgraph_AGG
903 
904   Input Parameter:
905    . pc - this
906    . Amat - matrix on this fine level
907   Output Parameter:
908    . a_Gmat -
909 */
910 #undef __FUNCT__
911 #define __FUNCT__ "PCGAMGgraph_AGG"
912 PetscErrorCode PCGAMGgraph_AGG(PC pc,const Mat Amat,Mat *a_Gmat)
913 {
914   PetscErrorCode            ierr;
915   PC_MG                     *mg          = (PC_MG*)pc->data;
916   PC_GAMG                   *pc_gamg     = (PC_GAMG*)mg->innerctx;
917   const PetscInt            verbose      = pc_gamg->verbose;
918   const PetscReal           vfilter      = pc_gamg->threshold;
919   PC_GAMG_AGG               *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
920   PetscMPIInt               rank,size;
921   Mat                       Gmat;
922   MPI_Comm                  comm;
923   PetscBool /* set,flg , */ symm;
924 
925   PetscFunctionBegin;
926   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
927 #if defined PETSC_USE_LOG
928   ierr = PetscLogEventBegin(PC_GAMGGgraph_AGG,0,0,0,0);CHKERRQ(ierr);
929 #endif
930   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
931   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
932 
933   /* ierr = MatIsSymmetricKnown(Amat, &set, &flg);CHKERRQ(ierr); || !(set && flg) -- this causes lot of symm calls */
934   symm = (PetscBool)(pc_gamg_agg->sym_graph); /* && !pc_gamg_agg->square_graph; */
935 
936   ierr = PCGAMGCreateGraph(Amat, &Gmat);CHKERRQ(ierr);
937   ierr = PCGAMGFilterGraph(&Gmat, vfilter, symm, verbose);CHKERRQ(ierr);
938 
939   *a_Gmat = Gmat;
940 
941 #if defined PETSC_USE_LOG
942   ierr = PetscLogEventEnd(PC_GAMGGgraph_AGG,0,0,0,0);CHKERRQ(ierr);
943 #endif
944   PetscFunctionReturn(0);
945 }
946 
947 /* -------------------------------------------------------------------------- */
948 /*
949    PCGAMGCoarsen_AGG
950 
951   Input Parameter:
952    . a_pc - this
953   Input/Output Parameter:
954    . a_Gmat1 - graph on this fine level - coarsening can change this (squares it)
955   Output Parameter:
956    . agg_lists - list of aggregates
957 */
958 #undef __FUNCT__
959 #define __FUNCT__ "PCGAMGCoarsen_AGG"
960 PetscErrorCode PCGAMGCoarsen_AGG(PC a_pc,Mat *a_Gmat1,PetscCoarsenData **agg_lists)
961 {
962   PetscErrorCode ierr;
963   PC_MG          *mg          = (PC_MG*)a_pc->data;
964   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
965   PC_GAMG_AGG    *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
966   Mat            mat,Gmat2, Gmat1 = *a_Gmat1;  /* squared graph */
967   const PetscInt verbose = pc_gamg->verbose;
968   IS             perm;
969   PetscInt       Ii,nloc,bs,n,m;
970   PetscInt       *permute;
971   PetscBool      *bIndexSet;
972   MatCoarsen     crs;
973   MPI_Comm       comm;
974   PetscMPIInt    rank,size;
975 
976   PetscFunctionBegin;
977 #if defined PETSC_USE_LOG
978   ierr = PetscLogEventBegin(PC_GAMGCoarsen_AGG,0,0,0,0);CHKERRQ(ierr);
979 #endif
980   ierr = PetscObjectGetComm((PetscObject)Gmat1,&comm);CHKERRQ(ierr);
981   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
982   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
983   ierr = MatGetLocalSize(Gmat1, &n, &m);CHKERRQ(ierr);
984   ierr = MatGetBlockSize(Gmat1, &bs);CHKERRQ(ierr);
985   if (bs != 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"bs %D must be 1",bs);
986   nloc = n/bs;
987 
988   if (pc_gamg_agg->square_graph) {
989     if (verbose > 1) PetscPrintf(comm,"[%d]%s square graph\n",rank,__FUNCT__);
990     /* ierr = MatMatTransposeMult(Gmat1, Gmat1, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &Gmat2); */
991     ierr = MatTransposeMatMult(Gmat1, Gmat1, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &Gmat2);CHKERRQ(ierr);
992     if (verbose > 2) {
993       ierr = PetscPrintf(comm,"[%d]%s square graph done\n",rank,__FUNCT__);CHKERRQ(ierr);
994       /* check for symetry */
995       if (verbose > 4) {
996 
997       }
998     }
999   } else Gmat2 = Gmat1;
1000 
1001   /* get MIS aggs */
1002   /* randomize */
1003   ierr = PetscMalloc1(nloc, &permute);CHKERRQ(ierr);
1004   ierr = PetscMalloc1(nloc, &bIndexSet);CHKERRQ(ierr);
1005   for (Ii = 0; Ii < nloc; Ii++) {
1006     bIndexSet[Ii] = PETSC_FALSE;
1007     permute[Ii]   = Ii;
1008   }
1009   srand(1); /* make deterministic */
1010   for (Ii = 0; Ii < nloc; Ii++) {
1011     PetscInt iSwapIndex = rand()%nloc;
1012     if (!bIndexSet[iSwapIndex] && iSwapIndex != Ii) {
1013       PetscInt iTemp = permute[iSwapIndex];
1014       permute[iSwapIndex]   = permute[Ii];
1015       permute[Ii]           = iTemp;
1016       bIndexSet[iSwapIndex] = PETSC_TRUE;
1017     }
1018   }
1019   ierr = PetscFree(bIndexSet);CHKERRQ(ierr);
1020 
1021   if (verbose > 1) PetscPrintf(comm,"[%d]%s coarsen graph\n",rank,__FUNCT__);
1022 
1023   ierr = ISCreateGeneral(PETSC_COMM_SELF, nloc, permute, PETSC_USE_POINTER, &perm);CHKERRQ(ierr);
1024 #if defined PETSC_GAMG_USE_LOG
1025   ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET4],0,0,0,0);CHKERRQ(ierr);
1026 #endif
1027   ierr = MatCoarsenCreate(comm, &crs);CHKERRQ(ierr);
1028   /* ierr = MatCoarsenSetType(crs, MATCOARSENMIS);CHKERRQ(ierr); */
1029   ierr = MatCoarsenSetFromOptions(crs);CHKERRQ(ierr);
1030   ierr = MatCoarsenSetGreedyOrdering(crs, perm);CHKERRQ(ierr);
1031   ierr = MatCoarsenSetAdjacency(crs, Gmat2);CHKERRQ(ierr);
1032   ierr = MatCoarsenSetVerbose(crs, pc_gamg->verbose);CHKERRQ(ierr);
1033   ierr = MatCoarsenSetStrictAggs(crs, PETSC_TRUE);CHKERRQ(ierr);
1034   ierr = MatCoarsenApply(crs);CHKERRQ(ierr);
1035   ierr = MatCoarsenGetData(crs, agg_lists);CHKERRQ(ierr); /* output */
1036   ierr = MatCoarsenDestroy(&crs);CHKERRQ(ierr);
1037 
1038   ierr = ISDestroy(&perm);CHKERRQ(ierr);
1039   ierr = PetscFree(permute);CHKERRQ(ierr);
1040 #if defined PETSC_GAMG_USE_LOG
1041   ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET4],0,0,0,0);CHKERRQ(ierr);
1042 #endif
1043   if (verbose > 2) PetscPrintf(comm,"[%d]%s coarsen graph done\n",rank,__FUNCT__);
1044 
1045   /* smooth aggs */
1046   if (Gmat2 != Gmat1) {
1047     const PetscCoarsenData *llist = *agg_lists;
1048     ierr     = smoothAggs(Gmat2, Gmat1, *agg_lists);CHKERRQ(ierr);
1049     ierr     = MatDestroy(&Gmat1);CHKERRQ(ierr);
1050     *a_Gmat1 = Gmat2; /* output */
1051     ierr     = PetscCDGetMat(llist, &mat);CHKERRQ(ierr);
1052     if (mat) SETERRQ(comm,PETSC_ERR_ARG_WRONG, "Auxilary matrix with squared graph????");
1053   } else {
1054     const PetscCoarsenData *llist = *agg_lists;
1055     /* see if we have a matrix that takes precedence (returned from MatCoarsenAppply) */
1056     ierr = PetscCDGetMat(llist, &mat);CHKERRQ(ierr);
1057     if (mat) {
1058       ierr     = MatDestroy(&Gmat1);CHKERRQ(ierr);
1059       *a_Gmat1 = mat; /* output */
1060     }
1061   }
1062 #if defined PETSC_USE_LOG
1063   ierr = PetscLogEventEnd(PC_GAMGCoarsen_AGG,0,0,0,0);CHKERRQ(ierr);
1064 #endif
1065   if (verbose > 2) PetscPrintf(comm,"[%d]%s PCGAMGCoarsen_AGG done\n",rank,__FUNCT__);
1066   PetscFunctionReturn(0);
1067 }
1068 
1069 /* -------------------------------------------------------------------------- */
1070 /*
1071  PCGAMGProlongator_AGG
1072 
1073  Input Parameter:
1074  . pc - this
1075  . Amat - matrix on this fine level
1076  . Graph - used to get ghost data for nodes in
1077  . agg_lists - list of aggregates
1078  Output Parameter:
1079  . a_P_out - prolongation operator to the next level
1080  */
1081 #undef __FUNCT__
1082 #define __FUNCT__ "PCGAMGProlongator_AGG"
1083 PetscErrorCode PCGAMGProlongator_AGG(PC pc,const Mat Amat,const Mat Gmat,PetscCoarsenData *agg_lists,Mat *a_P_out)
1084 {
1085   PC_MG          *mg       = (PC_MG*)pc->data;
1086   PC_GAMG        *pc_gamg  = (PC_GAMG*)mg->innerctx;
1087   const PetscInt verbose   = pc_gamg->verbose;
1088   const PetscInt data_cols = pc_gamg->data_cell_cols;
1089   PetscErrorCode ierr;
1090   PetscInt       Istart,Iend,nloc,ii,jj,kk,my0,nLocalSelected,bs;
1091   Mat            Prol;
1092   PetscMPIInt    rank, size;
1093   MPI_Comm       comm;
1094   const PetscInt col_bs = data_cols;
1095   PetscReal      *data_w_ghost;
1096   PetscInt       myCrs0, nbnodes=0, *flid_fgid;
1097 
1098   PetscFunctionBegin;
1099   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1100 #if defined PETSC_USE_LOG
1101   ierr = PetscLogEventBegin(PC_GAMGProlongator_AGG,0,0,0,0);CHKERRQ(ierr);
1102 #endif
1103   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
1104   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
1105   ierr = MatGetOwnershipRange(Amat, &Istart, &Iend);CHKERRQ(ierr);
1106   ierr = MatGetBlockSize(Amat, &bs);CHKERRQ(ierr);
1107   nloc = (Iend-Istart)/bs; my0 = Istart/bs;
1108   if ((Iend-Istart) % bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"(Iend %D - Istart %D) not divisible by bs %D",Iend,Istart,bs);
1109 
1110   /* get 'nLocalSelected' */
1111   for (ii=0, nLocalSelected = 0; ii < nloc; ii++) {
1112     PetscBool ise;
1113     /* filter out singletons 0 or 1? */
1114     ierr = PetscCDEmptyAt(agg_lists, ii, &ise);CHKERRQ(ierr);
1115     if (!ise) nLocalSelected++;
1116   }
1117 
1118   /* create prolongator, create P matrix */
1119   ierr = MatCreate(comm, &Prol);CHKERRQ(ierr);
1120   ierr = MatSetSizes(Prol,nloc*bs,nLocalSelected*col_bs,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
1121   ierr = MatSetBlockSizes(Prol, bs, col_bs);CHKERRQ(ierr);
1122   ierr = MatSetType(Prol, MATAIJ);CHKERRQ(ierr);
1123   ierr = MatSeqAIJSetPreallocation(Prol, data_cols, NULL);CHKERRQ(ierr);
1124   ierr = MatMPIAIJSetPreallocation(Prol,data_cols, NULL,data_cols, NULL);CHKERRQ(ierr);
1125   /* nloc*bs, nLocalSelected*col_bs, */
1126   /* PETSC_DETERMINE, PETSC_DETERMINE, */
1127   /* data_cols, NULL, data_cols, NULL, */
1128   /* &Prol); */
1129 
1130   /* can get all points "removed" */
1131   ierr =  MatGetSize(Prol, &kk, &ii);CHKERRQ(ierr);
1132   if (ii==0) {
1133     if (verbose > 0) PetscPrintf(comm,"[%d]%s no selected points on coarse grid\n",rank,__FUNCT__);
1134     ierr = MatDestroy(&Prol);CHKERRQ(ierr);
1135     *a_P_out = NULL;  /* out */
1136     PetscFunctionReturn(0);
1137   }
1138   if (verbose > 0) PetscPrintf(comm,"\t\t[%d]%s New grid %d nodes\n",rank,__FUNCT__,ii/col_bs);
1139   ierr = MatGetOwnershipRangeColumn(Prol, &myCrs0, &kk);CHKERRQ(ierr);
1140 
1141   if ((kk-myCrs0) % col_bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"(kk %D -myCrs0 %D) not divisible by col_bs %D",kk,myCrs0,col_bs);
1142   myCrs0 = myCrs0/col_bs;
1143   if ((kk/col_bs-myCrs0) != nLocalSelected) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB,"(kk %D/col_bs %D - myCrs0 %D) != nLocalSelected %D)",kk,col_bs,myCrs0,nLocalSelected);
1144 
1145   /* create global vector of data in 'data_w_ghost' */
1146 #if defined PETSC_GAMG_USE_LOG
1147   ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET7],0,0,0,0);CHKERRQ(ierr);
1148 #endif
1149   if (size > 1) { /*  */
1150     PetscReal *tmp_gdata,*tmp_ldata,*tp2;
1151     ierr = PetscMalloc1(nloc, &tmp_ldata);CHKERRQ(ierr);
1152     for (jj = 0; jj < data_cols; jj++) {
1153       for (kk = 0; kk < bs; kk++) {
1154         PetscInt        ii,stride;
1155         const PetscReal *tp = pc_gamg->data + jj*bs*nloc + kk;
1156         for (ii = 0; ii < nloc; ii++, tp += bs) tmp_ldata[ii] = *tp;
1157 
1158         ierr = PCGAMGGetDataWithGhosts(Gmat, 1, tmp_ldata, &stride, &tmp_gdata);CHKERRQ(ierr);
1159 
1160         if (jj==0 && kk==0) { /* now I know how many todal nodes - allocate */
1161           ierr    = PetscMalloc1(stride*bs*data_cols, &data_w_ghost);CHKERRQ(ierr);
1162           nbnodes = bs*stride;
1163         }
1164         tp2 = data_w_ghost + jj*bs*stride + kk;
1165         for (ii = 0; ii < stride; ii++, tp2 += bs) *tp2 = tmp_gdata[ii];
1166         ierr = PetscFree(tmp_gdata);CHKERRQ(ierr);
1167       }
1168     }
1169     ierr = PetscFree(tmp_ldata);CHKERRQ(ierr);
1170   } else {
1171     nbnodes      = bs*nloc;
1172     data_w_ghost = (PetscReal*)pc_gamg->data;
1173   }
1174 
1175   /* get P0 */
1176   if (size > 1) {
1177     PetscReal *fid_glid_loc,*fiddata;
1178     PetscInt  stride;
1179 
1180     ierr = PetscMalloc1(nloc, &fid_glid_loc);CHKERRQ(ierr);
1181     for (kk=0; kk<nloc; kk++) fid_glid_loc[kk] = (PetscReal)(my0+kk);
1182     ierr = PCGAMGGetDataWithGhosts(Gmat, 1, fid_glid_loc, &stride, &fiddata);CHKERRQ(ierr);
1183     ierr = PetscMalloc1(stride, &flid_fgid);CHKERRQ(ierr);
1184     for (kk=0; kk<stride; kk++) flid_fgid[kk] = (PetscInt)fiddata[kk];
1185     ierr = PetscFree(fiddata);CHKERRQ(ierr);
1186 
1187     if (stride != nbnodes/bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"stride %D != nbnodes %D/bs %D",stride,nbnodes,bs);
1188     ierr = PetscFree(fid_glid_loc);CHKERRQ(ierr);
1189   } else {
1190     ierr = PetscMalloc1(nloc, &flid_fgid);CHKERRQ(ierr);
1191     for (kk=0; kk<nloc; kk++) flid_fgid[kk] = my0 + kk;
1192   }
1193 #if defined PETSC_GAMG_USE_LOG
1194   ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET7],0,0,0,0);CHKERRQ(ierr);
1195   ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET8],0,0,0,0);CHKERRQ(ierr);
1196 #endif
1197   {
1198     PetscReal *data_out = NULL;
1199     ierr = formProl0(agg_lists, bs, data_cols, myCrs0, nbnodes,data_w_ghost, flid_fgid, &data_out, Prol);CHKERRQ(ierr);
1200     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
1201 
1202     pc_gamg->data           = data_out;
1203     pc_gamg->data_cell_rows = data_cols;
1204     pc_gamg->data_sz        = data_cols*data_cols*nLocalSelected;
1205   }
1206 #if defined PETSC_GAMG_USE_LOG
1207   ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET8],0,0,0,0);CHKERRQ(ierr);
1208 #endif
1209   if (size > 1) ierr = PetscFree(data_w_ghost);CHKERRQ(ierr);
1210   ierr = PetscFree(flid_fgid);CHKERRQ(ierr);
1211 
1212   *a_P_out = Prol;  /* out */
1213 
1214 #if defined PETSC_USE_LOG
1215   ierr = PetscLogEventEnd(PC_GAMGProlongator_AGG,0,0,0,0);CHKERRQ(ierr);
1216 #endif
1217   PetscFunctionReturn(0);
1218 }
1219 
1220 /* -------------------------------------------------------------------------- */
1221 /*
1222    PCGAMGOptprol_AGG
1223 
1224   Input Parameter:
1225    . pc - this
1226    . Amat - matrix on this fine level
1227  In/Output Parameter:
1228    . a_P_out - prolongation operator to the next level
1229 */
1230 #undef __FUNCT__
1231 #define __FUNCT__ "PCGAMGOptprol_AGG"
1232 PetscErrorCode PCGAMGOptprol_AGG(PC pc,const Mat Amat,Mat *a_P)
1233 {
1234   PetscErrorCode ierr;
1235   PC_MG          *mg          = (PC_MG*)pc->data;
1236   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
1237   const PetscInt verbose      = pc_gamg->verbose;
1238   PC_GAMG_AGG    *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
1239   PetscInt       jj;
1240   PetscMPIInt    rank,size;
1241   Mat            Prol  = *a_P;
1242   MPI_Comm       comm;
1243 
1244   PetscFunctionBegin;
1245   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1246 #if defined PETSC_USE_LOG
1247   ierr = PetscLogEventBegin(PC_GAMGOptprol_AGG,0,0,0,0);CHKERRQ(ierr);
1248 #endif
1249   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
1250   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
1251 
1252   /* smooth P0 */
1253   for (jj = 0; jj < pc_gamg_agg->nsmooths; jj++) {
1254     Mat       tMat;
1255     Vec       diag;
1256     PetscReal alpha, emax, emin;
1257 #if defined PETSC_GAMG_USE_LOG
1258     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET9],0,0,0,0);CHKERRQ(ierr);
1259 #endif
1260     if (jj == 0) {
1261       KSP eksp;
1262       Vec bb, xx;
1263       PC  epc;
1264       ierr = MatGetVecs(Amat, &bb, 0);CHKERRQ(ierr);
1265       ierr = MatGetVecs(Amat, &xx, 0);CHKERRQ(ierr);
1266       {
1267         PetscRandom rctx;
1268         ierr = PetscRandomCreate(comm,&rctx);CHKERRQ(ierr);
1269         ierr = PetscRandomSetFromOptions(rctx);CHKERRQ(ierr);
1270         ierr = VecSetRandom(bb,rctx);CHKERRQ(ierr);
1271         ierr = PetscRandomDestroy(&rctx);CHKERRQ(ierr);
1272       }
1273 
1274       /* zeroing out BC rows -- needed for crazy matrices */
1275       {
1276         PetscInt    Istart,Iend,ncols,jj,Ii;
1277         PetscScalar zero = 0.0;
1278         ierr = MatGetOwnershipRange(Amat, &Istart, &Iend);CHKERRQ(ierr);
1279         for (Ii = Istart, jj = 0; Ii < Iend; Ii++, jj++) {
1280           ierr = MatGetRow(Amat,Ii,&ncols,0,0);CHKERRQ(ierr);
1281           if (ncols <= 1) {
1282             ierr = VecSetValues(bb, 1, &Ii, &zero, INSERT_VALUES);CHKERRQ(ierr);
1283           }
1284           ierr = MatRestoreRow(Amat,Ii,&ncols,0,0);CHKERRQ(ierr);
1285         }
1286         ierr = VecAssemblyBegin(bb);CHKERRQ(ierr);
1287         ierr = VecAssemblyEnd(bb);CHKERRQ(ierr);
1288       }
1289 
1290       ierr = KSPCreate(comm,&eksp);CHKERRQ(ierr);
1291       ierr = KSPSetTolerances(eksp,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,10);CHKERRQ(ierr);
1292       ierr = KSPSetNormType(eksp, KSP_NORM_NONE);CHKERRQ(ierr);
1293       ierr = KSPSetOptionsPrefix(eksp,((PetscObject)pc)->prefix);CHKERRQ(ierr);
1294       ierr = KSPAppendOptionsPrefix(eksp, "gamg_est_");CHKERRQ(ierr);
1295       ierr = KSPSetFromOptions(eksp);CHKERRQ(ierr);
1296 
1297       ierr = KSPSetInitialGuessNonzero(eksp, PETSC_FALSE);CHKERRQ(ierr);
1298       ierr = KSPSetOperators(eksp, Amat, Amat);CHKERRQ(ierr);
1299       ierr = KSPSetComputeSingularValues(eksp,PETSC_TRUE);CHKERRQ(ierr);
1300 
1301       ierr = KSPGetPC(eksp, &epc);CHKERRQ(ierr);
1302       ierr = PCSetType(epc, PCJACOBI);CHKERRQ(ierr);  /* smoother in smoothed agg. */
1303 
1304       /* solve - keep stuff out of logging */
1305       ierr = PetscLogEventDeactivate(KSP_Solve);CHKERRQ(ierr);
1306       ierr = PetscLogEventDeactivate(PC_Apply);CHKERRQ(ierr);
1307       ierr = KSPSolve(eksp, bb, xx);CHKERRQ(ierr);
1308       ierr = PetscLogEventActivate(KSP_Solve);CHKERRQ(ierr);
1309       ierr = PetscLogEventActivate(PC_Apply);CHKERRQ(ierr);
1310 
1311       ierr = KSPComputeExtremeSingularValues(eksp, &emax, &emin);CHKERRQ(ierr);
1312       if (verbose > 0) {
1313         PetscPrintf(comm,"\t\t\t%s smooth P0: max eigen=%e min=%e PC=%s\n",
1314                     __FUNCT__,emax,emin,PCJACOBI);
1315       }
1316       ierr = VecDestroy(&xx);CHKERRQ(ierr);
1317       ierr = VecDestroy(&bb);CHKERRQ(ierr);
1318       ierr = KSPDestroy(&eksp);CHKERRQ(ierr);
1319 
1320       if (pc_gamg->emax_id == -1) {
1321         ierr = PetscObjectComposedDataRegister(&pc_gamg->emax_id);CHKERRQ(ierr);
1322         if (pc_gamg->emax_id == -1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"pc_gamg->emax_id == -1");
1323       }
1324       ierr = PetscObjectComposedDataSetScalar((PetscObject)Amat, pc_gamg->emax_id, emax);CHKERRQ(ierr);
1325     }
1326 
1327     /* smooth P1 := (I - omega/lam D^{-1}A)P0 */
1328     ierr  = MatMatMult(Amat, Prol, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &tMat);CHKERRQ(ierr);
1329     ierr  = MatGetVecs(Amat, &diag, 0);CHKERRQ(ierr);
1330     ierr  = MatGetDiagonal(Amat, diag);CHKERRQ(ierr); /* effectively PCJACOBI */
1331     ierr  = VecReciprocal(diag);CHKERRQ(ierr);
1332     ierr  = MatDiagonalScale(tMat, diag, 0);CHKERRQ(ierr);
1333     ierr  = VecDestroy(&diag);CHKERRQ(ierr);
1334     alpha = -1.4/emax;
1335     ierr  = MatAYPX(tMat, alpha, Prol, SUBSET_NONZERO_PATTERN);CHKERRQ(ierr);
1336     ierr  = MatDestroy(&Prol);CHKERRQ(ierr);
1337     Prol  = tMat;
1338 #if defined PETSC_GAMG_USE_LOG
1339     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET9],0,0,0,0);CHKERRQ(ierr);
1340 #endif
1341   }
1342 #if defined PETSC_USE_LOG
1343   ierr = PetscLogEventEnd(PC_GAMGOptprol_AGG,0,0,0,0);CHKERRQ(ierr);
1344 #endif
1345   *a_P = Prol;
1346   PetscFunctionReturn(0);
1347 }
1348 
1349 /* -------------------------------------------------------------------------- */
1350 /*
1351    PCCreateGAMG_AGG
1352 
1353   Input Parameter:
1354    . pc -
1355 */
1356 #undef __FUNCT__
1357 #define __FUNCT__ "PCCreateGAMG_AGG"
1358 PetscErrorCode  PCCreateGAMG_AGG(PC pc)
1359 {
1360   PetscErrorCode ierr;
1361   PC_MG          *mg      = (PC_MG*)pc->data;
1362   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1363   PC_GAMG_AGG    *pc_gamg_agg;
1364 
1365   PetscFunctionBegin;
1366   /* create sub context for SA */
1367   ierr            = PetscNewLog(pc,&pc_gamg_agg);CHKERRQ(ierr);
1368   pc_gamg->subctx = pc_gamg_agg;
1369 
1370   pc_gamg->ops->setfromoptions = PCSetFromOptions_GAMG_AGG;
1371   pc_gamg->ops->destroy        = PCDestroy_GAMG_AGG;
1372   /* reset does not do anything; setup not virtual */
1373 
1374   /* set internal function pointers */
1375   pc_gamg->ops->graph       = PCGAMGgraph_AGG;
1376   pc_gamg->ops->coarsen     = PCGAMGCoarsen_AGG;
1377   pc_gamg->ops->prolongator = PCGAMGProlongator_AGG;
1378   pc_gamg->ops->optprol     = PCGAMGOptprol_AGG;
1379 
1380   pc_gamg->ops->createdefaultdata = PCSetData_AGG;
1381 
1382   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCSetCoordinates_C",PCSetCoordinates_AGG);CHKERRQ(ierr);
1383   PetscFunctionReturn(0);
1384 }
1385