xref: /petsc/src/ksp/pc/impls/gamg/agg.c (revision bcab024551cbaaaa7f49e357634a3584f91cb6d5)
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 
158   PetscFunctionBegin;
159   ierr = PetscOptionsHead("GAMG-AGG options");CHKERRQ(ierr);
160   {
161     /* -pc_gamg_agg_nsmooths */
162     pc_gamg_agg->nsmooths = 1;
163 
164     ierr = PetscOptionsInt("-pc_gamg_agg_nsmooths","smoothing steps for smoothed aggregation, usually 1","PCGAMGSetNSmooths",pc_gamg_agg->nsmooths,&pc_gamg_agg->nsmooths,NULL);CHKERRQ(ierr);
165 
166     /* -pc_gamg_sym_graph */
167     pc_gamg_agg->sym_graph = PETSC_FALSE;
168 
169     ierr = PetscOptionsBool("-pc_gamg_sym_graph","Set for asymmetric matrices","PCGAMGSetSymGraph",pc_gamg_agg->sym_graph,&pc_gamg_agg->sym_graph,NULL);CHKERRQ(ierr);
170 
171     /* -pc_gamg_square_graph */
172     pc_gamg_agg->square_graph = PETSC_TRUE;
173 
174     ierr = PetscOptionsBool("-pc_gamg_square_graph","For faster coarsening and lower coarse grid complexity","PCGAMGSetSquareGraph",pc_gamg_agg->square_graph,&pc_gamg_agg->square_graph,NULL);CHKERRQ(ierr);
175   }
176   ierr = PetscOptionsTail();CHKERRQ(ierr);
177   PetscFunctionReturn(0);
178 }
179 
180 /* -------------------------------------------------------------------------- */
181 /*
182    PCDestroy_AGG
183 
184   Input Parameter:
185    . pc -
186 */
187 #undef __FUNCT__
188 #define __FUNCT__ "PCDestroy_GAMG_AGG"
189 PetscErrorCode PCDestroy_GAMG_AGG(PC pc)
190 {
191   PetscErrorCode ierr;
192   PC_MG          *mg          = (PC_MG*)pc->data;
193   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
194 
195   PetscFunctionBegin;
196   ierr = PetscFree(pc_gamg->subctx);CHKERRQ(ierr);
197   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCSetCoordinates_C",NULL);CHKERRQ(ierr);
198   PetscFunctionReturn(0);
199 }
200 
201 /* -------------------------------------------------------------------------- */
202 /*
203    PCSetCoordinates_AGG
204      - collective
205 
206    Input Parameter:
207    . pc - the preconditioner context
208    . ndm - dimesion of data (used for dof/vertex for Stokes)
209    . a_nloc - number of vertices local
210    . coords - [a_nloc][ndm] - interleaved coordinate data: {x_0, y_0, z_0, x_1, y_1, ...}
211 */
212 
213 #undef __FUNCT__
214 #define __FUNCT__ "PCSetCoordinates_AGG"
215 static PetscErrorCode PCSetCoordinates_AGG(PC pc, PetscInt ndm, PetscInt a_nloc, PetscReal *coords)
216 {
217   PC_MG          *mg      = (PC_MG*)pc->data;
218   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
219   PetscErrorCode ierr;
220   PetscInt       arrsz,kk,ii,jj,nloc,ndatarows,ndf;
221   Mat            mat = pc->pmat;
222 
223   PetscFunctionBegin;
224   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
225   PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
226   nloc = a_nloc;
227 
228   /* SA: null space vectors */
229   ierr = MatGetBlockSize(mat, &ndf);CHKERRQ(ierr); /* this does not work for Stokes */
230   if (coords && ndf==1) pc_gamg->data_cell_cols = 1; /* scalar w/ coords and SA (not needed) */
231   else if (coords) {
232     if (ndm > ndf) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"degrees of motion %d > block size %d",ndm,ndf);
233     pc_gamg->data_cell_cols = (ndm==2 ? 3 : 6); /* displacement elasticity */
234     if (ndm != ndf) {
235       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);
236     }
237   } else pc_gamg->data_cell_cols = ndf; /* no data, force SA with constant null space vectors */
238   pc_gamg->data_cell_rows = ndatarows = ndf;
239   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);
240   arrsz = nloc*pc_gamg->data_cell_rows*pc_gamg->data_cell_cols;
241 
242   /* create data - syntactic sugar that should be refactored at some point */
243   if (pc_gamg->data==0 || (pc_gamg->data_sz != arrsz)) {
244     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
245     ierr = PetscMalloc1((arrsz+1), &pc_gamg->data);CHKERRQ(ierr);
246   }
247   /* copy data in - column oriented */
248   for (kk=0; kk<nloc; kk++) {
249     const PetscInt M     = nloc*pc_gamg->data_cell_rows; /* stride into data */
250     PetscReal      *data = &pc_gamg->data[kk*ndatarows]; /* start of cell */
251     if (pc_gamg->data_cell_cols==1) *data = 1.0;
252     else {
253       /* translational modes */
254       for (ii=0;ii<ndatarows;ii++) {
255         for (jj=0;jj<ndatarows;jj++) {
256           if (ii==jj)data[ii*M + jj] = 1.0;
257           else data[ii*M + jj] = 0.0;
258         }
259       }
260 
261       /* rotational modes */
262       if (coords) {
263         if (ndm == 2) {
264           data   += 2*M;
265           data[0] = -coords[2*kk+1];
266           data[1] =  coords[2*kk];
267         } else {
268           data   += 3*M;
269           data[0] = 0.0;             data[M+0] =  coords[3*kk+2]; data[2*M+0] = -coords[3*kk+1];
270           data[1] = -coords[3*kk+2]; data[M+1] = 0.0;             data[2*M+1] =  coords[3*kk];
271           data[2] =  coords[3*kk+1]; data[M+2] = -coords[3*kk];   data[2*M+2] = 0.0;
272         }
273       }
274     }
275   }
276 
277   pc_gamg->data_sz = arrsz;
278   PetscFunctionReturn(0);
279 }
280 
281 typedef PetscInt NState;
282 static const NState NOT_DONE=-2;
283 static const NState DELETED =-1;
284 static const NState REMOVED =-3;
285 #define IS_SELECTED(s) (s!=DELETED && s!=NOT_DONE && s!=REMOVED)
286 
287 /* -------------------------------------------------------------------------- */
288 /*
289    smoothAggs - greedy grab of with G1 (unsquared graph) -- AIJ specific
290      - AGG-MG specific: clears singletons out of 'selected_2'
291 
292    Input Parameter:
293    . Gmat_2 - glabal matrix of graph (data not defined)
294    . Gmat_1 - base graph to grab with
295    Input/Output Parameter:
296    . aggs_2 - linked list of aggs with gids)
297 */
298 #undef __FUNCT__
299 #define __FUNCT__ "smoothAggs"
300 static PetscErrorCode smoothAggs(const Mat Gmat_2, /* base (squared) graph */
301                                  const Mat Gmat_1,  /* base graph */
302                                  /* const IS selected_2, [nselected local] selected vertices */
303                                  PetscCoarsenData *aggs_2)  /* [nselected local] global ID of aggregate */
304 {
305   PetscErrorCode ierr;
306   PetscBool      isMPI;
307   Mat_SeqAIJ     *matA_1, *matB_1=0, *matA_2, *matB_2=0;
308   MPI_Comm       comm;
309   PetscMPIInt    rank,size;
310   PetscInt       lid,*ii,*idx,ix,Iend,my0,kk,n,j;
311   Mat_MPIAIJ     *mpimat_2 = 0, *mpimat_1=0;
312   const PetscInt nloc      = Gmat_2->rmap->n;
313   PetscScalar    *cpcol_1_state,*cpcol_2_state,*cpcol_2_par_orig,*lid_parent_gid;
314   PetscInt       *lid_cprowID_1;
315   NState         *lid_state;
316   Vec            ghost_par_orig2;
317 
318   PetscFunctionBegin;
319   ierr = PetscObjectGetComm((PetscObject)Gmat_2,&comm);CHKERRQ(ierr);
320   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
321   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
322   ierr = MatGetOwnershipRange(Gmat_1,&my0,&Iend);CHKERRQ(ierr);
323 
324   if (PETSC_FALSE) {
325     PetscViewer viewer; char fname[32]; static int llev=0;
326     sprintf(fname,"Gmat2_%d.m",llev++);
327     PetscViewerASCIIOpen(comm,fname,&viewer);
328     ierr = PetscViewerSetFormat(viewer, PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
329     ierr = MatView(Gmat_2, viewer);CHKERRQ(ierr);
330     ierr = PetscViewerDestroy(&viewer);
331   }
332 
333   /* get submatrices */
334   ierr = PetscObjectTypeCompare((PetscObject)Gmat_1, MATMPIAIJ, &isMPI);CHKERRQ(ierr);
335   if (isMPI) {
336     /* grab matrix objects */
337     mpimat_2 = (Mat_MPIAIJ*)Gmat_2->data;
338     mpimat_1 = (Mat_MPIAIJ*)Gmat_1->data;
339     matA_1   = (Mat_SeqAIJ*)mpimat_1->A->data;
340     matB_1   = (Mat_SeqAIJ*)mpimat_1->B->data;
341     matA_2   = (Mat_SeqAIJ*)mpimat_2->A->data;
342     matB_2   = (Mat_SeqAIJ*)mpimat_2->B->data;
343 
344     /* force compressed row storage for B matrix in AuxMat */
345     ierr = MatCheckCompressedRow(mpimat_1->B,matB_1->nonzerorowcnt,&matB_1->compressedrow,matB_1->i,Gmat_1->rmap->n,-1.0);CHKERRQ(ierr);
346 
347     ierr = PetscMalloc1(nloc, &lid_cprowID_1);CHKERRQ(ierr);
348     for (lid = 0; lid < nloc; lid++) lid_cprowID_1[lid] = -1;
349     for (ix=0; ix<matB_1->compressedrow.nrows; ix++) {
350       PetscInt lid = matB_1->compressedrow.rindex[ix];
351       lid_cprowID_1[lid] = ix;
352     }
353   } else {
354     matA_1        = (Mat_SeqAIJ*)Gmat_1->data;
355     matA_2        = (Mat_SeqAIJ*)Gmat_2->data;
356     lid_cprowID_1 = NULL;
357   }
358   if (nloc>0) {
359     if (!(matA_1 && !matA_1->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matA_1 && !matA_1->compressedrow.use)");
360     if (!(matB_1==0 || matB_1->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matB_1==0 || matB_1->compressedrow.use)");
361     if (!(matA_2 && !matA_2->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matA_2 && !matA_2->compressedrow.use)");
362     if (!(matB_2==0 || matB_2->compressedrow.use)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"!(matB_2==0 || matB_2->compressedrow.use)");
363   }
364   /* get state of locals and selected gid for deleted */
365   ierr = PetscMalloc1(nloc, &lid_state);CHKERRQ(ierr);
366   ierr = PetscMalloc1(nloc, &lid_parent_gid);CHKERRQ(ierr);
367   for (lid = 0; lid < nloc; lid++) {
368     lid_parent_gid[lid] = -1.0;
369     lid_state[lid]      = DELETED;
370   }
371 
372   /* set lid_state */
373   for (lid = 0; lid < nloc; lid++) {
374     PetscCDPos pos;
375     ierr = PetscCDGetHeadPos(aggs_2,lid,&pos);CHKERRQ(ierr);
376     if (pos) {
377       PetscInt gid1;
378 
379       ierr = PetscLLNGetID(pos, &gid1);CHKERRQ(ierr);
380       if (gid1 != lid+my0) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"gid1 %D != lid %D + my0 %D",gid1,lid,my0);
381       lid_state[lid] = gid1;
382     }
383   }
384 
385   /* map local to selected local, DELETED means a ghost owns it */
386   for (lid=kk=0; lid<nloc; lid++) {
387     NState state = lid_state[lid];
388     if (IS_SELECTED(state)) {
389       PetscCDPos pos;
390       ierr = PetscCDGetHeadPos(aggs_2,lid,&pos);CHKERRQ(ierr);
391       while (pos) {
392         PetscInt gid1;
393         ierr = PetscLLNGetID(pos, &gid1);CHKERRQ(ierr);
394         ierr = PetscCDGetNextPos(aggs_2,lid,&pos);CHKERRQ(ierr);
395 
396         if (gid1 >= my0 && gid1 < Iend) lid_parent_gid[gid1-my0] = (PetscScalar)(lid + my0);
397       }
398     }
399   }
400   /* get 'cpcol_1/2_state' & cpcol_2_par_orig - uses mpimat_1/2->lvec for temp space */
401   if (isMPI) {
402     Vec tempVec;
403     /* get 'cpcol_1_state' */
404     ierr = MatCreateVecs(Gmat_1, &tempVec, 0);CHKERRQ(ierr);
405     for (kk=0,j=my0; kk<nloc; kk++,j++) {
406       PetscScalar v = (PetscScalar)lid_state[kk];
407       ierr = VecSetValues(tempVec, 1, &j, &v, INSERT_VALUES);CHKERRQ(ierr);
408     }
409     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
410     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
411     ierr = VecScatterBegin(mpimat_1->Mvctx,tempVec, mpimat_1->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
412     ierr =   VecScatterEnd(mpimat_1->Mvctx,tempVec, mpimat_1->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
413     ierr = VecGetArray(mpimat_1->lvec, &cpcol_1_state);CHKERRQ(ierr);
414     /* get 'cpcol_2_state' */
415     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, mpimat_2->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
416     ierr =   VecScatterEnd(mpimat_2->Mvctx,tempVec, mpimat_2->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
417     ierr = VecGetArray(mpimat_2->lvec, &cpcol_2_state);CHKERRQ(ierr);
418     /* get 'cpcol_2_par_orig' */
419     for (kk=0,j=my0; kk<nloc; kk++,j++) {
420       PetscScalar v = (PetscScalar)lid_parent_gid[kk];
421       ierr = VecSetValues(tempVec, 1, &j, &v, INSERT_VALUES);CHKERRQ(ierr);
422     }
423     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
424     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
425     ierr = VecDuplicate(mpimat_2->lvec, &ghost_par_orig2);CHKERRQ(ierr);
426     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, ghost_par_orig2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
427     ierr =   VecScatterEnd(mpimat_2->Mvctx,tempVec, ghost_par_orig2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
428     ierr = VecGetArray(ghost_par_orig2, &cpcol_2_par_orig);CHKERRQ(ierr);
429 
430     ierr = VecDestroy(&tempVec);CHKERRQ(ierr);
431   } /* ismpi */
432 
433   /* doit */
434   for (lid=0; lid<nloc; lid++) {
435     NState state = lid_state[lid];
436     if (IS_SELECTED(state)) {
437       /* steal locals */
438       ii  = matA_1->i; n = ii[lid+1] - ii[lid];
439       idx = matA_1->j + ii[lid];
440       for (j=0; j<n; j++) {
441         PetscInt lidj   = idx[j], sgid;
442         NState   statej = lid_state[lidj];
443         if (statej==DELETED && (sgid=(PetscInt)PetscRealPart(lid_parent_gid[lidj])) != lid+my0) { /* steal local */
444           lid_parent_gid[lidj] = (PetscScalar)(lid+my0); /* send this if sgid is not local */
445           if (sgid >= my0 && sgid < Iend) {       /* I'm stealing this local from a local sgid */
446             PetscInt   hav=0,slid=sgid-my0,gidj=lidj+my0;
447             PetscCDPos pos,last=NULL;
448             /* looking for local from local so id_llist_2 works */
449             ierr = PetscCDGetHeadPos(aggs_2,slid,&pos);CHKERRQ(ierr);
450             while (pos) {
451               PetscInt gid;
452               ierr = PetscLLNGetID(pos, &gid);CHKERRQ(ierr);
453               if (gid == gidj) {
454                 if (!last) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"last cannot be null");
455                 ierr = PetscCDRemoveNextNode(aggs_2, slid, last);CHKERRQ(ierr);
456                 ierr = PetscCDAppendNode(aggs_2, lid, pos);CHKERRQ(ierr);
457                 hav  = 1;
458                 break;
459               } else last = pos;
460 
461               ierr = PetscCDGetNextPos(aggs_2,slid,&pos);CHKERRQ(ierr);
462             }
463             if (hav!=1) {
464               if (!hav) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"failed to find adj in 'selected' lists - structurally unsymmetric matrix");
465               SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"found node %d times???",hav);
466             }
467           } else {            /* I'm stealing this local, owned by a ghost */
468             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.");
469             ierr = PetscCDAppendID(aggs_2, lid, lidj+my0);CHKERRQ(ierr);
470           }
471         }
472       } /* local neighbors */
473     } else if (state == DELETED && lid_cprowID_1) {
474       PetscInt sgidold = (PetscInt)PetscRealPart(lid_parent_gid[lid]);
475       /* see if I have a selected ghost neighbor that will steal me */
476       if ((ix=lid_cprowID_1[lid]) != -1) {
477         ii  = matB_1->compressedrow.i; n = ii[ix+1] - ii[ix];
478         idx = matB_1->j + ii[ix];
479         for (j=0; j<n; j++) {
480           PetscInt cpid   = idx[j];
481           NState   statej = (NState)PetscRealPart(cpcol_1_state[cpid]);
482           if (IS_SELECTED(statej) && sgidold != (PetscInt)statej) { /* ghost will steal this, remove from my list */
483             lid_parent_gid[lid] = (PetscScalar)statej; /* send who selected */
484             if (sgidold>=my0 && sgidold<Iend) { /* this was mine */
485               PetscInt   hav=0,oldslidj=sgidold-my0;
486               PetscCDPos pos,last=NULL;
487               /* remove from 'oldslidj' list */
488               ierr = PetscCDGetHeadPos(aggs_2,oldslidj,&pos);CHKERRQ(ierr);
489               while (pos) {
490                 PetscInt gid;
491                 ierr = PetscLLNGetID(pos, &gid);CHKERRQ(ierr);
492                 if (lid+my0 == gid) {
493                   /* id_llist_2[lastid] = id_llist_2[flid];   /\* remove lid from oldslidj list *\/ */
494                   if (!last) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"last cannot be null");
495                   ierr = PetscCDRemoveNextNode(aggs_2, oldslidj, last);CHKERRQ(ierr);
496                   /* ghost (PetscScalar)statej will add this later */
497                   hav = 1;
498                   break;
499                 } else last = pos;
500 
501                 ierr = PetscCDGetNextPos(aggs_2,oldslidj,&pos);CHKERRQ(ierr);
502               }
503               if (hav!=1) {
504                 if (hav==0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"failed to find adj in 'selected' lists - structurally unsymmetric matrix");
505                 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"found node %d times???",hav);
506               }
507             } else {
508               /* ghosts remove this later */
509             }
510           }
511         }
512       }
513     } /* selected/deleted */
514   } /* node loop */
515 
516   if (isMPI) {
517     PetscScalar   *cpcol_2_parent,*cpcol_2_gid;
518     Vec           tempVec,ghostgids2,ghostparents2;
519     PetscInt      cpid,nghost_2;
520     GAMGHashTable gid_cpid;
521 
522     ierr = VecGetSize(mpimat_2->lvec, &nghost_2);CHKERRQ(ierr);
523     ierr = MatCreateVecs(Gmat_2, &tempVec, 0);CHKERRQ(ierr);
524 
525     /* get 'cpcol_2_parent' */
526     for (kk=0,j=my0; kk<nloc; kk++,j++) {
527       ierr = VecSetValues(tempVec, 1, &j, &lid_parent_gid[kk], INSERT_VALUES);CHKERRQ(ierr);
528     }
529     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
530     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
531     ierr = VecDuplicate(mpimat_2->lvec, &ghostparents2);CHKERRQ(ierr);
532     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, ghostparents2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
533     ierr = VecScatterEnd(mpimat_2->Mvctx,tempVec, ghostparents2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
534     ierr = VecGetArray(ghostparents2, &cpcol_2_parent);CHKERRQ(ierr);
535 
536     /* get 'cpcol_2_gid' */
537     for (kk=0,j=my0; kk<nloc; kk++,j++) {
538       PetscScalar v = (PetscScalar)j;
539       ierr = VecSetValues(tempVec, 1, &j, &v, INSERT_VALUES);CHKERRQ(ierr);
540     }
541     ierr = VecAssemblyBegin(tempVec);CHKERRQ(ierr);
542     ierr = VecAssemblyEnd(tempVec);CHKERRQ(ierr);
543     ierr = VecDuplicate(mpimat_2->lvec, &ghostgids2);CHKERRQ(ierr);
544     ierr = VecScatterBegin(mpimat_2->Mvctx,tempVec, ghostgids2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
545     ierr =   VecScatterEnd(mpimat_2->Mvctx,tempVec, ghostgids2,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
546     ierr = VecGetArray(ghostgids2, &cpcol_2_gid);CHKERRQ(ierr);
547 
548     ierr = VecDestroy(&tempVec);CHKERRQ(ierr);
549 
550     /* look for deleted ghosts and add to table */
551     ierr = GAMGTableCreate(2*nghost_2+1, &gid_cpid);CHKERRQ(ierr);
552     for (cpid = 0; cpid < nghost_2; cpid++) {
553       NState state = (NState)PetscRealPart(cpcol_2_state[cpid]);
554       if (state==DELETED) {
555         PetscInt sgid_new = (PetscInt)PetscRealPart(cpcol_2_parent[cpid]);
556         PetscInt sgid_old = (PetscInt)PetscRealPart(cpcol_2_par_orig[cpid]);
557         if (sgid_old == -1 && sgid_new != -1) {
558           PetscInt gid = (PetscInt)PetscRealPart(cpcol_2_gid[cpid]);
559           ierr = GAMGTableAdd(&gid_cpid, gid, cpid);CHKERRQ(ierr);
560         }
561       }
562     }
563 
564     /* look for deleted ghosts and see if they moved - remove it */
565     for (lid=0; lid<nloc; lid++) {
566       NState state = lid_state[lid];
567       if (IS_SELECTED(state)) {
568         PetscCDPos pos,last=NULL;
569         /* look for deleted ghosts and see if they moved */
570         ierr = PetscCDGetHeadPos(aggs_2,lid,&pos);CHKERRQ(ierr);
571         while (pos) {
572           PetscInt gid;
573           ierr = PetscLLNGetID(pos, &gid);CHKERRQ(ierr);
574 
575           if (gid < my0 || gid >= Iend) {
576             ierr = GAMGTableFind(&gid_cpid, gid, &cpid);CHKERRQ(ierr);
577             if (cpid != -1) {
578               /* a moved ghost - */
579               /* id_llist_2[lastid] = id_llist_2[flid];    /\* remove 'flid' from list *\/ */
580               ierr = PetscCDRemoveNextNode(aggs_2, lid, last);CHKERRQ(ierr);
581             } else last = pos;
582           } else last = pos;
583 
584           ierr = PetscCDGetNextPos(aggs_2,lid,&pos);CHKERRQ(ierr);
585         } /* loop over list of deleted */
586       } /* selected */
587     }
588     ierr = GAMGTableDestroy(&gid_cpid);CHKERRQ(ierr);
589 
590     /* look at ghosts, see if they changed - and it */
591     for (cpid = 0; cpid < nghost_2; cpid++) {
592       PetscInt sgid_new = (PetscInt)PetscRealPart(cpcol_2_parent[cpid]);
593       if (sgid_new >= my0 && sgid_new < Iend) { /* this is mine */
594         PetscInt   gid     = (PetscInt)PetscRealPart(cpcol_2_gid[cpid]);
595         PetscInt   slid_new=sgid_new-my0,hav=0;
596         PetscCDPos pos;
597         /* search for this gid to see if I have it */
598         ierr = PetscCDGetHeadPos(aggs_2,slid_new,&pos);CHKERRQ(ierr);
599         while (pos) {
600           PetscInt gidj;
601           ierr = PetscLLNGetID(pos, &gidj);CHKERRQ(ierr);
602           ierr = PetscCDGetNextPos(aggs_2,slid_new,&pos);CHKERRQ(ierr);
603 
604           if (gidj == gid) { hav = 1; break; }
605         }
606         if (hav != 1) {
607           /* insert 'flidj' into head of llist */
608           ierr = PetscCDAppendID(aggs_2, slid_new, gid);CHKERRQ(ierr);
609         }
610       }
611     }
612 
613     ierr = VecRestoreArray(mpimat_1->lvec, &cpcol_1_state);CHKERRQ(ierr);
614     ierr = VecRestoreArray(mpimat_2->lvec, &cpcol_2_state);CHKERRQ(ierr);
615     ierr = VecRestoreArray(ghostparents2, &cpcol_2_parent);CHKERRQ(ierr);
616     ierr = VecRestoreArray(ghostgids2, &cpcol_2_gid);CHKERRQ(ierr);
617     ierr = PetscFree(lid_cprowID_1);CHKERRQ(ierr);
618     ierr = VecDestroy(&ghostgids2);CHKERRQ(ierr);
619     ierr = VecDestroy(&ghostparents2);CHKERRQ(ierr);
620     ierr = VecDestroy(&ghost_par_orig2);CHKERRQ(ierr);
621   }
622 
623   ierr = PetscFree(lid_parent_gid);CHKERRQ(ierr);
624   ierr = PetscFree(lid_state);CHKERRQ(ierr);
625   PetscFunctionReturn(0);
626 }
627 
628 /* -------------------------------------------------------------------------- */
629 /*
630    PCSetData_AGG - called if data is not set with PCSetCoordinates.
631       Looks in Mat for near null space.
632       Does not work for Stokes
633 
634   Input Parameter:
635    . pc -
636    . a_A - matrix to get (near) null space out of.
637 */
638 #undef __FUNCT__
639 #define __FUNCT__ "PCSetData_AGG"
640 PetscErrorCode PCSetData_AGG(PC pc, Mat a_A)
641 {
642   PetscErrorCode ierr;
643   PC_MG          *mg      = (PC_MG*)pc->data;
644   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
645   MatNullSpace   mnull;
646 
647   PetscFunctionBegin;
648   ierr = MatGetNearNullSpace(a_A, &mnull);CHKERRQ(ierr);
649   if (!mnull) {
650     PetscInt bs,NN,MM;
651     ierr = MatGetBlockSize(a_A, &bs);CHKERRQ(ierr);
652     ierr = MatGetLocalSize(a_A, &MM, &NN);CHKERRQ(ierr);
653     if (MM % bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MM %D must be divisible by bs %D",MM,bs);
654     ierr = PCSetCoordinates_AGG(pc, bs, MM/bs, NULL);CHKERRQ(ierr);
655   } else {
656     PetscReal *nullvec;
657     PetscBool has_const;
658     PetscInt  i,j,mlocal,nvec,bs;
659     const Vec *vecs; const PetscScalar *v;
660     ierr = MatGetLocalSize(a_A,&mlocal,NULL);CHKERRQ(ierr);
661     ierr = MatNullSpaceGetVecs(mnull, &has_const, &nvec, &vecs);CHKERRQ(ierr);
662     pc_gamg->data_sz = (nvec+!!has_const)*mlocal;
663     ierr = PetscMalloc1((nvec+!!has_const)*mlocal,&nullvec);CHKERRQ(ierr);
664     if (has_const) for (i=0; i<mlocal; i++) nullvec[i] = 1.0;
665     for (i=0; i<nvec; i++) {
666       ierr = VecGetArrayRead(vecs[i],&v);CHKERRQ(ierr);
667       for (j=0; j<mlocal; j++) nullvec[(i+!!has_const)*mlocal + j] = PetscRealPart(v[j]);
668       ierr = VecRestoreArrayRead(vecs[i],&v);CHKERRQ(ierr);
669     }
670     pc_gamg->data           = nullvec;
671     pc_gamg->data_cell_cols = (nvec+!!has_const);
672 
673     ierr = MatGetBlockSize(a_A, &bs);CHKERRQ(ierr);
674 
675     pc_gamg->data_cell_rows = bs;
676   }
677   PetscFunctionReturn(0);
678 }
679 
680 /* -------------------------------------------------------------------------- */
681 /*
682  formProl0
683 
684    Input Parameter:
685    . agg_llists - list of arrays with aggregates
686    . bs - block size
687    . nSAvec - column bs of new P
688    . my0crs - global index of start of locals
689    . data_stride - bs*(nloc nodes + ghost nodes)
690    . data_in[data_stride*nSAvec] - local data on fine grid
691    . flid_fgid[data_stride/bs] - make local to global IDs, includes ghosts in 'locals_llist'
692   Output Parameter:
693    . a_data_out - in with fine grid data (w/ghosts), out with coarse grid data
694    . a_Prol - prolongation operator
695 */
696 #undef __FUNCT__
697 #define __FUNCT__ "formProl0"
698 static PetscErrorCode formProl0(const PetscCoarsenData *agg_llists, /* list from selected vertices of aggregate unselected vertices */
699                                 const PetscInt bs,          /* (row) block size */
700                                 const PetscInt nSAvec,      /* column bs */
701                                 const PetscInt my0crs,      /* global index of start of locals */
702                                 const PetscInt data_stride, /* (nloc+nghost)*bs */
703                                 PetscReal      data_in[],   /* [data_stride][nSAvec] */
704                                 const PetscInt flid_fgid[], /* [data_stride/bs] */
705                                 PetscReal **a_data_out,
706                                 Mat a_Prol) /* prolongation operator (output)*/
707 {
708   PetscErrorCode ierr;
709   PetscInt       Istart,my0,Iend,nloc,clid,flid,aggID,kk,jj,ii,mm,ndone,nSelected,minsz,nghosts,out_data_stride;
710   MPI_Comm       comm;
711   PetscMPIInt    rank, size;
712   PetscReal      *out_data;
713   PetscCDPos     pos;
714   GAMGHashTable  fgid_flid;
715 
716 /* #define OUT_AGGS */
717 #if defined(OUT_AGGS)
718   static PetscInt llev = 0; char fname[32]; FILE *file = NULL; PetscInt pM;
719 #endif
720 
721   PetscFunctionBegin;
722   ierr = PetscObjectGetComm((PetscObject)a_Prol,&comm);CHKERRQ(ierr);
723   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
724   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
725   ierr = MatGetOwnershipRange(a_Prol, &Istart, &Iend);CHKERRQ(ierr);
726   nloc = (Iend-Istart)/bs; my0 = Istart/bs;
727   if ((Iend-Istart) % bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Iend %D - Istart %d must be divisible by bs %D",Iend,Istart,bs);
728   Iend   /= bs;
729   nghosts = data_stride/bs - nloc;
730 
731   ierr = GAMGTableCreate(2*nghosts+1, &fgid_flid);CHKERRQ(ierr);
732   for (kk=0; kk<nghosts; kk++) {
733     ierr = GAMGTableAdd(&fgid_flid, flid_fgid[nloc+kk], nloc+kk);CHKERRQ(ierr);
734   }
735 
736 #if defined(OUT_AGGS)
737   sprintf(fname,"aggs_%d_%d.m",llev++,rank);
738   if (llev==1) file = fopen(fname,"w");
739   MatGetSize(a_Prol, &pM, &jj);
740 #endif
741 
742   /* count selected -- same as number of cols of P */
743   for (nSelected=mm=0; mm<nloc; mm++) {
744     PetscBool ise;
745     ierr = PetscCDEmptyAt(agg_llists, mm, &ise);CHKERRQ(ierr);
746     if (!ise) nSelected++;
747   }
748   ierr = MatGetOwnershipRangeColumn(a_Prol, &ii, &jj);CHKERRQ(ierr);
749   if ((ii/nSAvec) != my0crs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"ii %D /nSAvec %D  != my0crs %D",ii,nSAvec,my0crs);
750   if (nSelected != (jj-ii)/nSAvec) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_PLIB,"nSelected %D != (jj %D - ii %D)/nSAvec %D",nSelected,jj,ii,nSAvec);
751 
752   /* aloc space for coarse point data (output) */
753   out_data_stride = nSelected*nSAvec;
754 
755   ierr = PetscMalloc1(out_data_stride*nSAvec, &out_data);CHKERRQ(ierr);
756   for (ii=0;ii<out_data_stride*nSAvec;ii++) out_data[ii]=PETSC_MAX_REAL;
757   *a_data_out = out_data; /* output - stride nSelected*nSAvec */
758 
759   /* find points and set prolongation */
760   minsz = 100;
761   ndone = 0;
762   for (mm = clid = 0; mm < nloc; mm++) {
763     ierr = PetscCDSizeAt(agg_llists, mm, &jj);CHKERRQ(ierr);
764     if (jj > 0) {
765       const PetscInt lid = mm, cgid = my0crs + clid;
766       PetscInt       cids[100]; /* max bs */
767       PetscBLASInt   asz  =jj,M=asz*bs,N=nSAvec,INFO;
768       PetscBLASInt   Mdata=M+((N-M>0) ? N-M : 0),LDA=Mdata,LWORK=N*bs;
769       PetscScalar    *qqc,*qqr,*TAU,*WORK;
770       PetscInt       *fids;
771       PetscReal      *data;
772       /* count agg */
773       if (asz<minsz) minsz = asz;
774 
775       /* get block */
776       ierr = PetscMalloc1((Mdata*N), &qqc);CHKERRQ(ierr);
777       ierr = PetscMalloc1((M*N), &qqr);CHKERRQ(ierr);
778       ierr = PetscMalloc1(N, &TAU);CHKERRQ(ierr);
779       ierr = PetscMalloc1(LWORK, &WORK);CHKERRQ(ierr);
780       ierr = PetscMalloc1(M, &fids);CHKERRQ(ierr);
781 
782       aggID = 0;
783       ierr  = PetscCDGetHeadPos(agg_llists,lid,&pos);CHKERRQ(ierr);
784       while (pos) {
785         PetscInt gid1;
786         ierr = PetscLLNGetID(pos, &gid1);CHKERRQ(ierr);
787         ierr = PetscCDGetNextPos(agg_llists,lid,&pos);CHKERRQ(ierr);
788 
789         if (gid1 >= my0 && gid1 < Iend) flid = gid1 - my0;
790         else {
791           ierr = GAMGTableFind(&fgid_flid, gid1, &flid);CHKERRQ(ierr);
792           if (flid < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Cannot find gid1 in table");
793         }
794         /* copy in B_i matrix - column oriented */
795         data = &data_in[flid*bs];
796         for (kk = ii = 0; ii < bs; ii++) {
797           for (jj = 0; jj < N; jj++) {
798             PetscReal d = data[jj*data_stride + ii];
799             qqc[jj*Mdata + aggID*bs + ii] = d;
800           }
801         }
802 #if defined(OUT_AGGS)
803         if (llev==1) {
804           char     str[] = "plot(%e,%e,'r*'), hold on,\n", col[] = "rgbkmc", sim[] = "*os+h>d<vx^";
805           PetscInt MM,pi,pj;
806           str[12] = col[(clid+17*rank)%6]; str[13] = sim[(clid+17*rank)%11];
807           MM      = (PetscInt)(PetscSqrtReal((PetscReal)pM));
808           pj      = gid1/MM; pi = gid1%MM;
809           fprintf(file,str,(double)pi,(double)pj);
810           /* fprintf(file,str,data[2*data_stride+1],-data[2*data_stride]); */
811         }
812 #endif
813         /* set fine IDs */
814         for (kk=0; kk<bs; kk++) fids[aggID*bs + kk] = flid_fgid[flid]*bs + kk;
815 
816         aggID++;
817       }
818 
819       /* pad with zeros */
820       for (ii = asz*bs; ii < Mdata; ii++) {
821         for (jj = 0; jj < N; jj++, kk++) {
822           qqc[jj*Mdata + ii] = .0;
823         }
824       }
825 
826       ndone += aggID;
827       /* QR */
828       ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
829       PetscStackCallBLAS("LAPACKgeqrf",LAPACKgeqrf_(&Mdata, &N, qqc, &LDA, TAU, WORK, &LWORK, &INFO));
830       ierr = PetscFPTrapPop();CHKERRQ(ierr);
831       if (INFO != 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"xGEQRF error");
832       /* get R - column oriented - output B_{i+1} */
833       {
834         PetscReal *data = &out_data[clid*nSAvec];
835         for (jj = 0; jj < nSAvec; jj++) {
836           for (ii = 0; ii < nSAvec; ii++) {
837             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);
838            if (ii <= jj) data[jj*out_data_stride + ii] = PetscRealPart(qqc[jj*Mdata + ii]);
839            else data[jj*out_data_stride + ii] = 0.;
840           }
841         }
842       }
843 
844       /* get Q - row oriented */
845       PetscStackCallBLAS("LAPACKungqr",LAPACKungqr_(&Mdata, &N, &N, qqc, &LDA, TAU, WORK, &LWORK, &INFO));
846       if (INFO != 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"xORGQR error arg %d",-INFO);
847 
848       for (ii = 0; ii < M; ii++) {
849         for (jj = 0; jj < N; jj++) {
850           qqr[N*ii + jj] = qqc[jj*Mdata + ii];
851         }
852       }
853 
854       /* add diagonal block of P0 */
855       for (kk=0; kk<N; kk++) {
856         cids[kk] = N*cgid + kk; /* global col IDs in P0 */
857       }
858       ierr = MatSetValues(a_Prol,M,fids,N,cids,qqr,INSERT_VALUES);CHKERRQ(ierr);
859 
860       ierr = PetscFree(qqc);CHKERRQ(ierr);
861       ierr = PetscFree(qqr);CHKERRQ(ierr);
862       ierr = PetscFree(TAU);CHKERRQ(ierr);
863       ierr = PetscFree(WORK);CHKERRQ(ierr);
864       ierr = PetscFree(fids);CHKERRQ(ierr);
865       clid++;
866     } /* coarse agg */
867   } /* for all fine nodes */
868   ierr = MatAssemblyBegin(a_Prol,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
869   ierr = MatAssemblyEnd(a_Prol,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
870 
871 /* ierr = MPI_Allreduce(&ndone, &ii, 1, MPIU_INT, MPIU_SUM, comm); */
872 /* MatGetSize(a_Prol, &kk, &jj); */
873 /* ierr = MPI_Allreduce(&minsz, &jj, 1, MPIU_INT, MPIU_MIN, comm); */
874 /* PetscPrintf(comm," **** [%d]%s %d total done, %d nodes (%d local done), min agg. size = %d\n",rank,__FUNCT__,ii,kk/bs,ndone,jj); */
875 
876 #if defined(OUT_AGGS)
877   if (llev==1) fclose(file);
878 #endif
879   ierr = GAMGTableDestroy(&fgid_flid);CHKERRQ(ierr);
880   PetscFunctionReturn(0);
881 }
882 
883 /* -------------------------------------------------------------------------- */
884 /*
885    PCGAMGgraph_AGG
886 
887   Input Parameter:
888    . pc - this
889    . Amat - matrix on this fine level
890   Output Parameter:
891    . a_Gmat -
892 */
893 #undef __FUNCT__
894 #define __FUNCT__ "PCGAMGgraph_AGG"
895 PetscErrorCode PCGAMGgraph_AGG(PC pc,const Mat Amat,Mat *a_Gmat)
896 {
897   PetscErrorCode            ierr;
898   PC_MG                     *mg          = (PC_MG*)pc->data;
899   PC_GAMG                   *pc_gamg     = (PC_GAMG*)mg->innerctx;
900   const PetscInt            verbose      = pc_gamg->verbose;
901   const PetscReal           vfilter      = pc_gamg->threshold;
902   PC_GAMG_AGG               *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
903   PetscMPIInt               rank,size;
904   Mat                       Gmat;
905   MPI_Comm                  comm;
906   PetscBool /* set,flg , */ symm;
907 
908   PetscFunctionBegin;
909   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
910 #if defined PETSC_USE_LOG
911   ierr = PetscLogEventBegin(PC_GAMGGgraph_AGG,0,0,0,0);CHKERRQ(ierr);
912 #endif
913   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
914   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
915 
916   /* ierr = MatIsSymmetricKnown(Amat, &set, &flg);CHKERRQ(ierr); || !(set && flg) -- this causes lot of symm calls */
917   symm = (PetscBool)(pc_gamg_agg->sym_graph); /* && !pc_gamg_agg->square_graph; */
918 
919   ierr = PCGAMGCreateGraph(Amat, &Gmat);CHKERRQ(ierr);
920   ierr = PCGAMGFilterGraph(&Gmat, vfilter, symm, verbose);CHKERRQ(ierr);
921 
922   *a_Gmat = Gmat;
923 
924 #if defined PETSC_USE_LOG
925   ierr = PetscLogEventEnd(PC_GAMGGgraph_AGG,0,0,0,0);CHKERRQ(ierr);
926 #endif
927   PetscFunctionReturn(0);
928 }
929 
930 /* -------------------------------------------------------------------------- */
931 /*
932    PCGAMGCoarsen_AGG
933 
934   Input Parameter:
935    . a_pc - this
936   Input/Output Parameter:
937    . a_Gmat1 - graph on this fine level - coarsening can change this (squares it)
938   Output Parameter:
939    . agg_lists - list of aggregates
940 */
941 #undef __FUNCT__
942 #define __FUNCT__ "PCGAMGCoarsen_AGG"
943 PetscErrorCode PCGAMGCoarsen_AGG(PC a_pc,Mat *a_Gmat1,PetscCoarsenData **agg_lists)
944 {
945   PetscErrorCode ierr;
946   PC_MG          *mg          = (PC_MG*)a_pc->data;
947   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
948   PC_GAMG_AGG    *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
949   Mat            mat,Gmat2, Gmat1 = *a_Gmat1;  /* squared graph */
950   const PetscInt verbose = pc_gamg->verbose;
951   IS             perm;
952   PetscInt       Ii,nloc,bs,n,m;
953   PetscInt       *permute;
954   PetscBool      *bIndexSet;
955   MatCoarsen     crs;
956   MPI_Comm       comm;
957   PetscMPIInt    rank,size;
958 
959   PetscFunctionBegin;
960 #if defined PETSC_USE_LOG
961   ierr = PetscLogEventBegin(PC_GAMGCoarsen_AGG,0,0,0,0);CHKERRQ(ierr);
962 #endif
963   ierr = PetscObjectGetComm((PetscObject)Gmat1,&comm);CHKERRQ(ierr);
964   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
965   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
966   ierr = MatGetLocalSize(Gmat1, &n, &m);CHKERRQ(ierr);
967   ierr = MatGetBlockSize(Gmat1, &bs);CHKERRQ(ierr);
968   if (bs != 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"bs %D must be 1",bs);
969   nloc = n/bs;
970 
971   if (pc_gamg_agg->square_graph) {
972     if (verbose > 1) PetscPrintf(comm,"[%d]%s square graph\n",rank,__FUNCT__);
973     /* ierr = MatMatTransposeMult(Gmat1, Gmat1, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &Gmat2); */
974     ierr = MatTransposeMatMult(Gmat1, Gmat1, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &Gmat2);CHKERRQ(ierr);
975     if (verbose > 2) {
976       ierr = PetscPrintf(comm,"[%d]%s square graph done\n",rank,__FUNCT__);CHKERRQ(ierr);
977       /* check for symetry */
978       if (verbose > 4) {
979 
980       }
981     }
982   } else Gmat2 = Gmat1;
983 
984   /* get MIS aggs */
985   /* randomize */
986   ierr = PetscMalloc1(nloc, &permute);CHKERRQ(ierr);
987   ierr = PetscMalloc1(nloc, &bIndexSet);CHKERRQ(ierr);
988   for (Ii = 0; Ii < nloc; Ii++) {
989     bIndexSet[Ii] = PETSC_FALSE;
990     permute[Ii]   = Ii;
991   }
992   srand(1); /* make deterministic */
993   for (Ii = 0; Ii < nloc; Ii++) {
994     PetscInt iSwapIndex = rand()%nloc;
995     if (!bIndexSet[iSwapIndex] && iSwapIndex != Ii) {
996       PetscInt iTemp = permute[iSwapIndex];
997       permute[iSwapIndex]   = permute[Ii];
998       permute[Ii]           = iTemp;
999       bIndexSet[iSwapIndex] = PETSC_TRUE;
1000     }
1001   }
1002   ierr = PetscFree(bIndexSet);CHKERRQ(ierr);
1003 
1004   if (verbose > 1) PetscPrintf(comm,"[%d]%s coarsen graph\n",rank,__FUNCT__);
1005 
1006   ierr = ISCreateGeneral(PETSC_COMM_SELF, nloc, permute, PETSC_USE_POINTER, &perm);CHKERRQ(ierr);
1007 #if defined PETSC_GAMG_USE_LOG
1008   ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET4],0,0,0,0);CHKERRQ(ierr);
1009 #endif
1010   ierr = MatCoarsenCreate(comm, &crs);CHKERRQ(ierr);
1011   /* ierr = MatCoarsenSetType(crs, MATCOARSENMIS);CHKERRQ(ierr); */
1012   ierr = MatCoarsenSetFromOptions(crs);CHKERRQ(ierr);
1013   ierr = MatCoarsenSetGreedyOrdering(crs, perm);CHKERRQ(ierr);
1014   ierr = MatCoarsenSetAdjacency(crs, Gmat2);CHKERRQ(ierr);
1015   ierr = MatCoarsenSetVerbose(crs, pc_gamg->verbose);CHKERRQ(ierr);
1016   ierr = MatCoarsenSetStrictAggs(crs, PETSC_TRUE);CHKERRQ(ierr);
1017   ierr = MatCoarsenApply(crs);CHKERRQ(ierr);
1018   ierr = MatCoarsenGetData(crs, agg_lists);CHKERRQ(ierr); /* output */
1019   ierr = MatCoarsenDestroy(&crs);CHKERRQ(ierr);
1020 
1021   ierr = ISDestroy(&perm);CHKERRQ(ierr);
1022   ierr = PetscFree(permute);CHKERRQ(ierr);
1023 #if defined PETSC_GAMG_USE_LOG
1024   ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET4],0,0,0,0);CHKERRQ(ierr);
1025 #endif
1026   if (verbose > 2) PetscPrintf(comm,"[%d]%s coarsen graph done\n",rank,__FUNCT__);
1027 
1028   /* smooth aggs */
1029   if (Gmat2 != Gmat1) {
1030     const PetscCoarsenData *llist = *agg_lists;
1031     ierr     = smoothAggs(Gmat2, Gmat1, *agg_lists);CHKERRQ(ierr);
1032     ierr     = MatDestroy(&Gmat1);CHKERRQ(ierr);
1033     *a_Gmat1 = Gmat2; /* output */
1034     ierr     = PetscCDGetMat(llist, &mat);CHKERRQ(ierr);
1035     if (mat) SETERRQ(comm,PETSC_ERR_ARG_WRONG, "Auxilary matrix with squared graph????");
1036   } else {
1037     const PetscCoarsenData *llist = *agg_lists;
1038     /* see if we have a matrix that takes precedence (returned from MatCoarsenAppply) */
1039     ierr = PetscCDGetMat(llist, &mat);CHKERRQ(ierr);
1040     if (mat) {
1041       ierr     = MatDestroy(&Gmat1);CHKERRQ(ierr);
1042       *a_Gmat1 = mat; /* output */
1043     }
1044   }
1045 #if defined PETSC_USE_LOG
1046   ierr = PetscLogEventEnd(PC_GAMGCoarsen_AGG,0,0,0,0);CHKERRQ(ierr);
1047 #endif
1048   if (verbose > 2) PetscPrintf(comm,"[%d]%s PCGAMGCoarsen_AGG done\n",rank,__FUNCT__);
1049   PetscFunctionReturn(0);
1050 }
1051 
1052 /* -------------------------------------------------------------------------- */
1053 /*
1054  PCGAMGProlongator_AGG
1055 
1056  Input Parameter:
1057  . pc - this
1058  . Amat - matrix on this fine level
1059  . Graph - used to get ghost data for nodes in
1060  . agg_lists - list of aggregates
1061  Output Parameter:
1062  . a_P_out - prolongation operator to the next level
1063  */
1064 #undef __FUNCT__
1065 #define __FUNCT__ "PCGAMGProlongator_AGG"
1066 PetscErrorCode PCGAMGProlongator_AGG(PC pc,const Mat Amat,const Mat Gmat,PetscCoarsenData *agg_lists,Mat *a_P_out)
1067 {
1068   PC_MG          *mg       = (PC_MG*)pc->data;
1069   PC_GAMG        *pc_gamg  = (PC_GAMG*)mg->innerctx;
1070   const PetscInt verbose   = pc_gamg->verbose;
1071   const PetscInt data_cols = pc_gamg->data_cell_cols;
1072   PetscErrorCode ierr;
1073   PetscInt       Istart,Iend,nloc,ii,jj,kk,my0,nLocalSelected,bs;
1074   Mat            Prol;
1075   PetscMPIInt    rank, size;
1076   MPI_Comm       comm;
1077   const PetscInt col_bs = data_cols;
1078   PetscReal      *data_w_ghost;
1079   PetscInt       myCrs0, nbnodes=0, *flid_fgid;
1080 
1081   PetscFunctionBegin;
1082   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1083 #if defined PETSC_USE_LOG
1084   ierr = PetscLogEventBegin(PC_GAMGProlongator_AGG,0,0,0,0);CHKERRQ(ierr);
1085 #endif
1086   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
1087   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
1088   ierr = MatGetOwnershipRange(Amat, &Istart, &Iend);CHKERRQ(ierr);
1089   ierr = MatGetBlockSize(Amat, &bs);CHKERRQ(ierr);
1090   nloc = (Iend-Istart)/bs; my0 = Istart/bs;
1091   if ((Iend-Istart) % bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"(Iend %D - Istart %D) not divisible by bs %D",Iend,Istart,bs);
1092 
1093   /* get 'nLocalSelected' */
1094   for (ii=0, nLocalSelected = 0; ii < nloc; ii++) {
1095     PetscBool ise;
1096     /* filter out singletons 0 or 1? */
1097     ierr = PetscCDEmptyAt(agg_lists, ii, &ise);CHKERRQ(ierr);
1098     if (!ise) nLocalSelected++;
1099   }
1100 
1101   /* create prolongator, create P matrix */
1102   ierr = MatCreate(comm, &Prol);CHKERRQ(ierr);
1103   ierr = MatSetSizes(Prol,nloc*bs,nLocalSelected*col_bs,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
1104   ierr = MatSetBlockSizes(Prol, bs, col_bs);CHKERRQ(ierr);
1105   ierr = MatSetType(Prol, MATAIJ);CHKERRQ(ierr);
1106   ierr = MatSeqAIJSetPreallocation(Prol, data_cols, NULL);CHKERRQ(ierr);
1107   ierr = MatMPIAIJSetPreallocation(Prol,data_cols, NULL,data_cols, NULL);CHKERRQ(ierr);
1108   /* nloc*bs, nLocalSelected*col_bs, */
1109   /* PETSC_DETERMINE, PETSC_DETERMINE, */
1110   /* data_cols, NULL, data_cols, NULL, */
1111   /* &Prol); */
1112 
1113   /* can get all points "removed" */
1114   ierr =  MatGetSize(Prol, &kk, &ii);CHKERRQ(ierr);
1115   if (ii==0) {
1116     if (verbose > 0) PetscPrintf(comm,"[%d]%s no selected points on coarse grid\n",rank,__FUNCT__);
1117     ierr = MatDestroy(&Prol);CHKERRQ(ierr);
1118     *a_P_out = NULL;  /* out */
1119     PetscFunctionReturn(0);
1120   }
1121   if (verbose > 0) PetscPrintf(comm,"\t\t[%d]%s New grid %d nodes\n",rank,__FUNCT__,ii/col_bs);
1122   ierr = MatGetOwnershipRangeColumn(Prol, &myCrs0, &kk);CHKERRQ(ierr);
1123 
1124   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);
1125   myCrs0 = myCrs0/col_bs;
1126   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);
1127 
1128   /* create global vector of data in 'data_w_ghost' */
1129 #if defined PETSC_GAMG_USE_LOG
1130   ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET7],0,0,0,0);CHKERRQ(ierr);
1131 #endif
1132   if (size > 1) { /*  */
1133     PetscReal *tmp_gdata,*tmp_ldata,*tp2;
1134     ierr = PetscMalloc1(nloc, &tmp_ldata);CHKERRQ(ierr);
1135     for (jj = 0; jj < data_cols; jj++) {
1136       for (kk = 0; kk < bs; kk++) {
1137         PetscInt        ii,stride;
1138         const PetscReal *tp = pc_gamg->data + jj*bs*nloc + kk;
1139         for (ii = 0; ii < nloc; ii++, tp += bs) tmp_ldata[ii] = *tp;
1140 
1141         ierr = PCGAMGGetDataWithGhosts(Gmat, 1, tmp_ldata, &stride, &tmp_gdata);CHKERRQ(ierr);
1142 
1143         if (jj==0 && kk==0) { /* now I know how many todal nodes - allocate */
1144           ierr    = PetscMalloc1(stride*bs*data_cols, &data_w_ghost);CHKERRQ(ierr);
1145           nbnodes = bs*stride;
1146         }
1147         tp2 = data_w_ghost + jj*bs*stride + kk;
1148         for (ii = 0; ii < stride; ii++, tp2 += bs) *tp2 = tmp_gdata[ii];
1149         ierr = PetscFree(tmp_gdata);CHKERRQ(ierr);
1150       }
1151     }
1152     ierr = PetscFree(tmp_ldata);CHKERRQ(ierr);
1153   } else {
1154     nbnodes      = bs*nloc;
1155     data_w_ghost = (PetscReal*)pc_gamg->data;
1156   }
1157 
1158   /* get P0 */
1159   if (size > 1) {
1160     PetscReal *fid_glid_loc,*fiddata;
1161     PetscInt  stride;
1162 
1163     ierr = PetscMalloc1(nloc, &fid_glid_loc);CHKERRQ(ierr);
1164     for (kk=0; kk<nloc; kk++) fid_glid_loc[kk] = (PetscReal)(my0+kk);
1165     ierr = PCGAMGGetDataWithGhosts(Gmat, 1, fid_glid_loc, &stride, &fiddata);CHKERRQ(ierr);
1166     ierr = PetscMalloc1(stride, &flid_fgid);CHKERRQ(ierr);
1167     for (kk=0; kk<stride; kk++) flid_fgid[kk] = (PetscInt)fiddata[kk];
1168     ierr = PetscFree(fiddata);CHKERRQ(ierr);
1169 
1170     if (stride != nbnodes/bs) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"stride %D != nbnodes %D/bs %D",stride,nbnodes,bs);
1171     ierr = PetscFree(fid_glid_loc);CHKERRQ(ierr);
1172   } else {
1173     ierr = PetscMalloc1(nloc, &flid_fgid);CHKERRQ(ierr);
1174     for (kk=0; kk<nloc; kk++) flid_fgid[kk] = my0 + kk;
1175   }
1176 #if defined PETSC_GAMG_USE_LOG
1177   ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET7],0,0,0,0);CHKERRQ(ierr);
1178   ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET8],0,0,0,0);CHKERRQ(ierr);
1179 #endif
1180   {
1181     PetscReal *data_out = NULL;
1182     ierr = formProl0(agg_lists, bs, data_cols, myCrs0, nbnodes,data_w_ghost, flid_fgid, &data_out, Prol);CHKERRQ(ierr);
1183     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
1184 
1185     pc_gamg->data           = data_out;
1186     pc_gamg->data_cell_rows = data_cols;
1187     pc_gamg->data_sz        = data_cols*data_cols*nLocalSelected;
1188   }
1189 #if defined PETSC_GAMG_USE_LOG
1190   ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET8],0,0,0,0);CHKERRQ(ierr);
1191 #endif
1192   if (size > 1) ierr = PetscFree(data_w_ghost);CHKERRQ(ierr);
1193   ierr = PetscFree(flid_fgid);CHKERRQ(ierr);
1194 
1195   *a_P_out = Prol;  /* out */
1196 
1197 #if defined PETSC_USE_LOG
1198   ierr = PetscLogEventEnd(PC_GAMGProlongator_AGG,0,0,0,0);CHKERRQ(ierr);
1199 #endif
1200   PetscFunctionReturn(0);
1201 }
1202 
1203 /* -------------------------------------------------------------------------- */
1204 /*
1205    PCGAMGOptprol_AGG
1206 
1207   Input Parameter:
1208    . pc - this
1209    . Amat - matrix on this fine level
1210  In/Output Parameter:
1211    . a_P_out - prolongation operator to the next level
1212 */
1213 #undef __FUNCT__
1214 #define __FUNCT__ "PCGAMGOptprol_AGG"
1215 PetscErrorCode PCGAMGOptprol_AGG(PC pc,const Mat Amat,Mat *a_P)
1216 {
1217   PetscErrorCode ierr;
1218   PC_MG          *mg          = (PC_MG*)pc->data;
1219   PC_GAMG        *pc_gamg     = (PC_GAMG*)mg->innerctx;
1220   const PetscInt verbose      = pc_gamg->verbose;
1221   PC_GAMG_AGG    *pc_gamg_agg = (PC_GAMG_AGG*)pc_gamg->subctx;
1222   PetscInt       jj;
1223   PetscMPIInt    rank,size;
1224   Mat            Prol  = *a_P;
1225   MPI_Comm       comm;
1226 
1227   PetscFunctionBegin;
1228   ierr = PetscObjectGetComm((PetscObject)Amat,&comm);CHKERRQ(ierr);
1229 #if defined PETSC_USE_LOG
1230   ierr = PetscLogEventBegin(PC_GAMGOptprol_AGG,0,0,0,0);CHKERRQ(ierr);
1231 #endif
1232   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
1233   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
1234 
1235   /* smooth P0 */
1236   for (jj = 0; jj < pc_gamg_agg->nsmooths; jj++) {
1237     Mat       tMat;
1238     Vec       diag;
1239     PetscReal alpha, emax, emin;
1240 #if defined PETSC_GAMG_USE_LOG
1241     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET9],0,0,0,0);CHKERRQ(ierr);
1242 #endif
1243     if (jj == 0) {
1244       KSP eksp;
1245       Vec bb, xx;
1246       PC  epc;
1247       ierr = MatCreateVecs(Amat, &bb, 0);CHKERRQ(ierr);
1248       ierr = MatCreateVecs(Amat, &xx, 0);CHKERRQ(ierr);
1249       {
1250         PetscRandom rctx;
1251         ierr = PetscRandomCreate(comm,&rctx);CHKERRQ(ierr);
1252         ierr = PetscRandomSetFromOptions(rctx);CHKERRQ(ierr);
1253         ierr = VecSetRandom(bb,rctx);CHKERRQ(ierr);
1254         ierr = PetscRandomDestroy(&rctx);CHKERRQ(ierr);
1255       }
1256 
1257       /* zeroing out BC rows -- needed for crazy matrices */
1258       {
1259         PetscInt    Istart,Iend,ncols,jj,Ii;
1260         PetscScalar zero = 0.0;
1261         ierr = MatGetOwnershipRange(Amat, &Istart, &Iend);CHKERRQ(ierr);
1262         for (Ii = Istart, jj = 0; Ii < Iend; Ii++, jj++) {
1263           ierr = MatGetRow(Amat,Ii,&ncols,0,0);CHKERRQ(ierr);
1264           if (ncols <= 1) {
1265             ierr = VecSetValues(bb, 1, &Ii, &zero, INSERT_VALUES);CHKERRQ(ierr);
1266           }
1267           ierr = MatRestoreRow(Amat,Ii,&ncols,0,0);CHKERRQ(ierr);
1268         }
1269         ierr = VecAssemblyBegin(bb);CHKERRQ(ierr);
1270         ierr = VecAssemblyEnd(bb);CHKERRQ(ierr);
1271       }
1272 
1273       ierr = KSPCreate(comm,&eksp);CHKERRQ(ierr);
1274       ierr = KSPSetTolerances(eksp,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,10);CHKERRQ(ierr);
1275       ierr = KSPSetNormType(eksp, KSP_NORM_NONE);CHKERRQ(ierr);
1276       ierr = KSPSetOptionsPrefix(eksp,((PetscObject)pc)->prefix);CHKERRQ(ierr);
1277       ierr = KSPAppendOptionsPrefix(eksp, "gamg_est_");CHKERRQ(ierr);
1278       ierr = KSPSetFromOptions(eksp);CHKERRQ(ierr);
1279 
1280       ierr = KSPSetInitialGuessNonzero(eksp, PETSC_FALSE);CHKERRQ(ierr);
1281       ierr = KSPSetOperators(eksp, Amat, Amat);CHKERRQ(ierr);
1282       ierr = KSPSetComputeSingularValues(eksp,PETSC_TRUE);CHKERRQ(ierr);
1283 
1284       ierr = KSPGetPC(eksp, &epc);CHKERRQ(ierr);
1285       ierr = PCSetType(epc, PCJACOBI);CHKERRQ(ierr);  /* smoother in smoothed agg. */
1286 
1287       /* solve - keep stuff out of logging */
1288       ierr = PetscLogEventDeactivate(KSP_Solve);CHKERRQ(ierr);
1289       ierr = PetscLogEventDeactivate(PC_Apply);CHKERRQ(ierr);
1290       ierr = KSPSolve(eksp, bb, xx);CHKERRQ(ierr);
1291       ierr = PetscLogEventActivate(KSP_Solve);CHKERRQ(ierr);
1292       ierr = PetscLogEventActivate(PC_Apply);CHKERRQ(ierr);
1293 
1294       ierr = KSPComputeExtremeSingularValues(eksp, &emax, &emin);CHKERRQ(ierr);
1295       if (verbose > 0) {
1296         PetscPrintf(comm,"\t\t\t%s smooth P0: max eigen=%e min=%e PC=%s\n",
1297                     __FUNCT__,emax,emin,PCJACOBI);
1298       }
1299       ierr = VecDestroy(&xx);CHKERRQ(ierr);
1300       ierr = VecDestroy(&bb);CHKERRQ(ierr);
1301       ierr = KSPDestroy(&eksp);CHKERRQ(ierr);
1302 
1303       if (pc_gamg->emax_id == -1) {
1304         ierr = PetscObjectComposedDataRegister(&pc_gamg->emax_id);CHKERRQ(ierr);
1305         if (pc_gamg->emax_id == -1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"pc_gamg->emax_id == -1");
1306       }
1307       ierr = PetscObjectComposedDataSetScalar((PetscObject)Amat, pc_gamg->emax_id, emax);CHKERRQ(ierr);
1308     }
1309 
1310     /* smooth P1 := (I - omega/lam D^{-1}A)P0 */
1311     ierr  = MatMatMult(Amat, Prol, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &tMat);CHKERRQ(ierr);
1312     ierr  = MatCreateVecs(Amat, &diag, 0);CHKERRQ(ierr);
1313     ierr  = MatGetDiagonal(Amat, diag);CHKERRQ(ierr); /* effectively PCJACOBI */
1314     ierr  = VecReciprocal(diag);CHKERRQ(ierr);
1315     ierr  = MatDiagonalScale(tMat, diag, 0);CHKERRQ(ierr);
1316     ierr  = VecDestroy(&diag);CHKERRQ(ierr);
1317     alpha = -1.4/emax;
1318     ierr  = MatAYPX(tMat, alpha, Prol, SUBSET_NONZERO_PATTERN);CHKERRQ(ierr);
1319     ierr  = MatDestroy(&Prol);CHKERRQ(ierr);
1320     Prol  = tMat;
1321 #if defined PETSC_GAMG_USE_LOG
1322     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET9],0,0,0,0);CHKERRQ(ierr);
1323 #endif
1324   }
1325 #if defined PETSC_USE_LOG
1326   ierr = PetscLogEventEnd(PC_GAMGOptprol_AGG,0,0,0,0);CHKERRQ(ierr);
1327 #endif
1328   *a_P = Prol;
1329   PetscFunctionReturn(0);
1330 }
1331 
1332 /* -------------------------------------------------------------------------- */
1333 /*
1334    PCCreateGAMG_AGG
1335 
1336   Input Parameter:
1337    . pc -
1338 */
1339 #undef __FUNCT__
1340 #define __FUNCT__ "PCCreateGAMG_AGG"
1341 PetscErrorCode  PCCreateGAMG_AGG(PC pc)
1342 {
1343   PetscErrorCode ierr;
1344   PC_MG          *mg      = (PC_MG*)pc->data;
1345   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1346   PC_GAMG_AGG    *pc_gamg_agg;
1347 
1348   PetscFunctionBegin;
1349   /* create sub context for SA */
1350   ierr            = PetscNewLog(pc,&pc_gamg_agg);CHKERRQ(ierr);
1351   pc_gamg->subctx = pc_gamg_agg;
1352 
1353   pc_gamg->ops->setfromoptions = PCSetFromOptions_GAMG_AGG;
1354   pc_gamg->ops->destroy        = PCDestroy_GAMG_AGG;
1355   /* reset does not do anything; setup not virtual */
1356 
1357   /* set internal function pointers */
1358   pc_gamg->ops->graph       = PCGAMGgraph_AGG;
1359   pc_gamg->ops->coarsen     = PCGAMGCoarsen_AGG;
1360   pc_gamg->ops->prolongator = PCGAMGProlongator_AGG;
1361   pc_gamg->ops->optprol     = PCGAMGOptprol_AGG;
1362 
1363   pc_gamg->ops->createdefaultdata = PCSetData_AGG;
1364 
1365   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCSetCoordinates_C",PCSetCoordinates_AGG);CHKERRQ(ierr);
1366   PetscFunctionReturn(0);
1367 }
1368