xref: /petsc/src/ksp/pc/impls/gamg/geo.c (revision 3bf036e263fd78807e2931ff42d9ddcd8aae3fd4)
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 #if defined(PETSC_HAVE_TRIANGLE)
9 #define REAL PetscReal
10 #include <triangle.h>
11 #endif
12 
13 #include <assert.h>
14 #include <petscblaslapack.h>
15 
16 /* Private context for the GAMG preconditioner */
17 typedef struct{
18   PetscInt       lid;      /* local vertex index */
19   PetscInt       degree;   /* vertex degree */
20 } GAMGNode;
21 int petsc_geo_mg_compare (const void *a, const void *b)
22 {
23   return (((GAMGNode*)a)->degree - ((GAMGNode*)b)->degree);
24 }
25 
26 /* -------------------------------------------------------------------------- */
27 /*
28    PCSetCoordinates_GEO
29 
30    Input Parameter:
31    .  pc - the preconditioner context
32 */
33 EXTERN_C_BEGIN
34 #undef __FUNCT__
35 #define __FUNCT__ "PCSetCoordinates_GEO"
36 PetscErrorCode PCSetCoordinates_GEO(PC pc, PetscInt ndm, PetscInt a_nloc, PetscReal *coords)
37 {
38   PC_MG          *mg = (PC_MG*)pc->data;
39   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
40   PetscErrorCode ierr;
41   PetscInt       arrsz,bs,my0,kk,ii,nloc,Iend;
42   Mat            Amat = pc->pmat;
43 
44   PetscFunctionBegin;
45   PetscValidHeaderSpecific(Amat, MAT_CLASSID, 1);
46   ierr  = MatGetBlockSize(Amat, &bs);CHKERRQ(ierr);
47 
48   ierr  = MatGetOwnershipRange(Amat, &my0, &Iend);CHKERRQ(ierr);
49   nloc = (Iend-my0)/bs;
50 
51   if (nloc!=a_nloc)SETERRQ2(((PetscObject)Amat)->comm,PETSC_ERR_ARG_WRONG, "Stokes not supported nloc = %d %d.",a_nloc,nloc);
52   if ((Iend-my0)%bs!=0) SETERRQ1(((PetscObject)Amat)->comm,PETSC_ERR_ARG_WRONG, "Bad local size %d.",nloc);
53 
54   pc_gamg->data_cell_rows = 1;
55   if (coords==0 && nloc > 0) SETERRQ(((PetscObject)Amat)->comm,PETSC_ERR_ARG_WRONG, "Need coordinates for pc_gamg_type 'geo'.");
56   pc_gamg->data_cell_cols = ndm; /* coordinates */
57 
58   arrsz = nloc*pc_gamg->data_cell_rows*pc_gamg->data_cell_cols;
59 
60   /* create data - syntactic sugar that should be refactored at some point */
61   if (pc_gamg->data==0 || (pc_gamg->data_sz != arrsz)) {
62     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
63     ierr = PetscMalloc((arrsz+1)*sizeof(PetscReal), &pc_gamg->data);CHKERRQ(ierr);
64   }
65   for (kk=0;kk<arrsz;kk++)pc_gamg->data[kk] = -999.;
66   pc_gamg->data[arrsz] = -99.;
67   /* copy data in - column oriented */
68   for (kk = 0 ; kk < nloc ; kk++){
69     for (ii = 0 ; ii < ndm ; ii++) {
70       pc_gamg->data[ii*nloc + kk] =  coords[kk*ndm + ii];
71     }
72   }
73   assert(pc_gamg->data[arrsz] == -99.);
74 
75   pc_gamg->data_sz = arrsz;
76 
77   PetscFunctionReturn(0);
78 }
79 EXTERN_C_END
80 
81 /* -------------------------------------------------------------------------- */
82 /*
83    PCSetData_GEO
84 
85   Input Parameter:
86    . pc -
87 */
88 #undef __FUNCT__
89 #define __FUNCT__ "PCSetData_GEO"
90 PetscErrorCode PCSetData_GEO(PC pc, Mat m)
91 {
92   PetscFunctionBegin;
93   SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_PLIB,"GEO MG needs coordinates");
94 }
95 
96 /* -------------------------------------------------------------------------- */
97 /*
98    PCSetFromOptions_GEO
99 
100   Input Parameter:
101    . pc -
102 */
103 #undef __FUNCT__
104 #define __FUNCT__ "PCSetFromOptions_GEO"
105 PetscErrorCode PCSetFromOptions_GEO(PC pc)
106 {
107   PetscErrorCode  ierr;
108   PC_MG           *mg = (PC_MG*)pc->data;
109   PC_GAMG         *pc_gamg = (PC_GAMG*)mg->innerctx;
110 
111   PetscFunctionBegin;
112   ierr = PetscOptionsHead("GAMG-GEO options");CHKERRQ(ierr);
113   {
114     /* -pc_gamg_sa_nsmooths */
115     /* pc_gamg_sa->smooths = 0; */
116     /* ierr = PetscOptionsInt("-pc_gamg_agg_nsmooths", */
117     /*                        "smoothing steps for smoothed aggregation, usually 1 (0)", */
118     /*                        "PCGAMGSetNSmooths_AGG", */
119     /*                        pc_gamg_sa->smooths, */
120     /*                        &pc_gamg_sa->smooths, */
121     /*                        &flag);  */
122     /* CHKERRQ(ierr); */
123   }
124   ierr = PetscOptionsTail();CHKERRQ(ierr);
125 
126   /* call base class */
127   ierr = PCSetFromOptions_GAMG(pc);CHKERRQ(ierr);
128 
129   if (pc_gamg->verbose) {
130     MPI_Comm  wcomm = ((PetscObject)pc)->comm;
131     PetscPrintf(wcomm,"[%d]%s done\n",0,__FUNCT__);
132   }
133 
134   PetscFunctionReturn(0);
135 }
136 
137 /* -------------------------------------------------------------------------- */
138 /*
139  triangulateAndFormProl
140 
141    Input Parameter:
142    . selected_2 - list of selected local ID, includes selected ghosts
143    . data_stride -
144    . coords[2*data_stride] - column vector of local coordinates w/ ghosts
145    . nselected_1 - selected IDs that go with base (1) graph
146    . clid_lid_1[nselected_1] - lids of selected (c) nodes   ???????????
147    . agg_lists_1 - list of aggregates
148    . crsGID[selected.size()] - global index for prolongation operator
149    . bs - block size
150   Output Parameter:
151    . a_Prol - prolongation operator
152    . a_worst_best - measure of worst missed fine vertex, 0 is no misses
153 */
154 #undef __FUNCT__
155 #define __FUNCT__ "triangulateAndFormProl"
156 static PetscErrorCode triangulateAndFormProl(IS  selected_2, /* list of selected local ID, includes selected ghosts */
157                                               const PetscInt data_stride,
158                                               const PetscReal coords[], /* column vector of local coordinates w/ ghosts */
159                                               const PetscInt nselected_1, /* list of selected local ID, includes selected ghosts */
160                                               const PetscInt clid_lid_1[],
161                                               const PetscCoarsenData *agg_lists_1, /* selected_1 vertices of aggregate unselected vertices */
162                                               const PetscInt crsGID[],
163                                               const PetscInt bs,
164                                               Mat a_Prol, /* prolongation operator (output) */
165                                               PetscReal *a_worst_best /* measure of worst missed fine vertex, 0 is no misses */
166                                              )
167 {
168 #if defined(PETSC_HAVE_TRIANGLE)
169   PetscErrorCode       ierr;
170   PetscInt             jj,tid,tt,idx,nselected_2;
171   struct triangulateio in,mid;
172   const PetscInt      *selected_idx_2;
173   PetscMPIInt          mype,npe;
174   PetscInt             Istart,Iend,nFineLoc,myFine0;
175   int                  kk,nPlotPts,sid;
176   MPI_Comm             wcomm = ((PetscObject)a_Prol)->comm;
177   PetscReal            tm;
178   PetscFunctionBegin;
179 
180   ierr = MPI_Comm_rank(wcomm,&mype);CHKERRQ(ierr);
181   ierr = MPI_Comm_size(wcomm,&npe);CHKERRQ(ierr);
182   ierr = ISGetSize(selected_2, &nselected_2);CHKERRQ(ierr);
183   if (nselected_2 == 1 || nselected_2 == 2){ /* 0 happens on idle processors */
184     *a_worst_best = 100.0; /* this will cause a stop, but not globalized (should not happen) */
185   } else *a_worst_best = 0.0;
186   ierr = MPI_Allreduce(a_worst_best, &tm, 1, MPIU_REAL, MPIU_MAX, wcomm);CHKERRQ(ierr);
187   if (tm > 0.0) {
188     *a_worst_best = 100.0;
189     PetscFunctionReturn(0);
190   }
191   ierr = MatGetOwnershipRange(a_Prol, &Istart, &Iend);CHKERRQ(ierr);
192   nFineLoc = (Iend-Istart)/bs; myFine0 = Istart/bs;
193   nPlotPts = nFineLoc; /* locals */
194   /* traingle */
195   /* Define input points - in*/
196   in.numberofpoints = nselected_2;
197   in.numberofpointattributes = 0;
198   /* get nselected points */
199   ierr = PetscMalloc(2*(nselected_2)*sizeof(REAL), &in.pointlist);CHKERRQ(ierr);
200   ierr = ISGetIndices(selected_2, &selected_idx_2);CHKERRQ(ierr);
201 
202   for (kk=0,sid=0;kk<nselected_2;kk++,sid += 2){
203     PetscInt lid = selected_idx_2[kk];
204     in.pointlist[sid] = coords[lid];
205     in.pointlist[sid+1] = coords[data_stride + lid];
206     if (lid>=nFineLoc) nPlotPts++;
207   }
208   assert(sid==2*nselected_2);
209 
210   in.numberofsegments = 0;
211   in.numberofedges = 0;
212   in.numberofholes = 0;
213   in.numberofregions = 0;
214   in.trianglelist = 0;
215   in.segmentmarkerlist = 0;
216   in.pointattributelist = 0;
217   in.pointmarkerlist = 0;
218   in.triangleattributelist = 0;
219   in.trianglearealist = 0;
220   in.segmentlist = 0;
221   in.holelist = 0;
222   in.regionlist = 0;
223   in.edgelist = 0;
224   in.edgemarkerlist = 0;
225   in.normlist = 0;
226   /* triangulate */
227   mid.pointlist = 0;            /* Not needed if -N switch used. */
228   /* Not needed if -N switch used or number of point attributes is zero: */
229   mid.pointattributelist = 0;
230   mid.pointmarkerlist = 0; /* Not needed if -N or -B switch used. */
231   mid.trianglelist = 0;          /* Not needed if -E switch used. */
232   /* Not needed if -E switch used or number of triangle attributes is zero: */
233   mid.triangleattributelist = 0;
234   mid.neighborlist = 0;         /* Needed only if -n switch used. */
235   /* Needed only if segments are output (-p or -c) and -P not used: */
236   mid.segmentlist = 0;
237   /* Needed only if segments are output (-p or -c) and -P and -B not used: */
238   mid.segmentmarkerlist = 0;
239   mid.edgelist = 0;             /* Needed only if -e switch used. */
240   mid.edgemarkerlist = 0;   /* Needed if -e used and -B not used. */
241   mid.numberoftriangles = 0;
242 
243   /* Triangulate the points.  Switches are chosen to read and write a  */
244   /*   PSLG (p), preserve the convex hull (c), number everything from  */
245   /*   zero (z), assign a regional attribute to each element (A), and  */
246   /*   produce an edge list (e), a Voronoi diagram (v), and a triangle */
247   /*   neighbor list (n).                                            */
248   if (nselected_2 != 0){ /* inactive processor */
249     char args[] = "npczQ"; /* c is needed ? */
250     triangulate(args, &in, &mid, (struct triangulateio *) NULL);
251     /* output .poly files for 'showme' */
252     if (!PETSC_TRUE) {
253       static int level = 1;
254       FILE *file; char fname[32];
255 
256       sprintf(fname,"C%d_%d.poly",level,mype); file = fopen(fname, "w");
257       /*First line: <# of vertices> <dimension (must be 2)> <# of attributes> <# of boundary markers (0 or 1)>*/
258       fprintf(file, "%d  %d  %d  %d\n",in.numberofpoints,2,0,0);
259       /*Following lines: <vertex #> <x> <y> */
260       for (kk=0,sid=0;kk<in.numberofpoints;kk++,sid += 2){
261         fprintf(file, "%d %e %e\n",kk,in.pointlist[sid],in.pointlist[sid+1]);
262       }
263       /*One line: <# of segments> <# of boundary markers (0 or 1)> */
264       fprintf(file, "%d  %d\n",0,0);
265       /*Following lines: <segment #> <endpoint> <endpoint> [boundary marker] */
266       /* One line: <# of holes> */
267       fprintf(file, "%d\n",0);
268       /* Following lines: <hole #> <x> <y> */
269       /* Optional line: <# of regional attributes and/or area constraints> */
270       /* Optional following lines: <region #> <x> <y> <attribute> <maximum area> */
271       fclose(file);
272 
273       /* elems */
274       sprintf(fname,"C%d_%d.ele",level,mype); file = fopen(fname, "w");
275       /* First line: <# of triangles> <nodes per triangle> <# of attributes> */
276       fprintf(file, "%d %d %d\n",mid.numberoftriangles,3,0);
277       /* Remaining lines: <triangle #> <node> <node> <node> ... [attributes] */
278       for (kk=0,sid=0;kk<mid.numberoftriangles;kk++,sid += 3){
279         fprintf(file, "%d %d %d %d\n",kk,mid.trianglelist[sid],mid.trianglelist[sid+1],mid.trianglelist[sid+2]);
280       }
281       fclose(file);
282 
283       sprintf(fname,"C%d_%d.node",level,mype); file = fopen(fname, "w");
284       /* First line: <# of vertices> <dimension (must be 2)> <# of attributes> <# of boundary markers (0 or 1)> */
285       /* fprintf(file, "%d  %d  %d  %d\n",in.numberofpoints,2,0,0); */
286       fprintf(file, "%d  %d  %d  %d\n",nPlotPts,2,0,0);
287       /*Following lines: <vertex #> <x> <y> */
288       for (kk=0,sid=0;kk<in.numberofpoints;kk++,sid+=2){
289         fprintf(file, "%d %e %e\n",kk,in.pointlist[sid],in.pointlist[sid+1]);
290       }
291 
292       sid /= 2;
293       for (jj=0;jj<nFineLoc;jj++){
294         PetscBool sel = PETSC_TRUE;
295         for (kk=0 ; kk<nselected_2 && sel ; kk++){
296           PetscInt lid = selected_idx_2[kk];
297           if (lid == jj) sel = PETSC_FALSE;
298         }
299         if (sel) {
300           fprintf(file, "%d %e %e\n",sid++,coords[jj],coords[data_stride + jj]);
301         }
302       }
303       fclose(file);
304       assert(sid==nPlotPts);
305       level++;
306     }
307   }
308 #if defined PETSC_GAMG_USE_LOG
309   ierr = PetscLogEventBegin(petsc_gamg_setup_events[FIND_V],0,0,0,0);CHKERRQ(ierr);
310 #endif
311   { /* form P - setup some maps */
312     PetscInt clid,mm,*nTri,*node_tri;
313 
314     ierr = PetscMalloc(nselected_2*sizeof(PetscInt), &node_tri);CHKERRQ(ierr);
315     ierr = PetscMalloc(nselected_2*sizeof(PetscInt), &nTri);CHKERRQ(ierr);
316 
317     /* need list of triangles on node */
318     for (kk=0;kk<nselected_2;kk++) nTri[kk] = 0;
319     for (tid=0,kk=0;tid<mid.numberoftriangles;tid++){
320       for (jj=0;jj<3;jj++) {
321         PetscInt cid = mid.trianglelist[kk++];
322         if (nTri[cid] == 0) node_tri[cid] = tid;
323         nTri[cid]++;
324       }
325     }
326 #define EPS 1.e-12
327     /* find points and set prolongation */
328     for (mm = clid = 0 ; mm < nFineLoc ; mm++){
329       PetscBool ise;
330       ierr = PetscCDEmptyAt(agg_lists_1,mm,&ise);CHKERRQ(ierr);
331       if (!ise) {
332         const PetscInt lid = mm;
333         //for (clid_iterator=0;clid_iterator<nselected_1;clid_iterator++){
334         //PetscInt flid = clid_lid_1[clid_iterator]; assert(flid != -1);
335         PetscScalar AA[3][3];
336         PetscBLASInt N=3,NRHS=1,LDA=3,IPIV[3],LDB=3,INFO;
337         PetscCDPos         pos;
338         ierr = PetscCDGetHeadPos(agg_lists_1,lid,&pos);CHKERRQ(ierr);
339         while(pos){
340           PetscInt flid;
341           ierr = PetscLLNGetID(pos, &flid);CHKERRQ(ierr);
342           ierr = PetscCDGetNextPos(agg_lists_1,lid,&pos);CHKERRQ(ierr);
343 
344           if (flid < nFineLoc) {  /* could be a ghost */
345             PetscInt bestTID = -1; PetscReal best_alpha = 1.e10;
346             const PetscInt fgid = flid + myFine0;
347             /* compute shape function for gid */
348             const PetscReal fcoord[3] = {coords[flid],coords[data_stride+flid],1.0};
349             PetscBool haveit=PETSC_FALSE; PetscScalar alpha[3]; PetscInt clids[3];
350             /* look for it */
351             for (tid = node_tri[clid], jj=0;
352                  jj < 5 && !haveit && tid != -1;
353                  jj++){
354               for (tt=0;tt<3;tt++){
355                 PetscInt cid2 = mid.trianglelist[3*tid + tt];
356                 PetscInt lid2 = selected_idx_2[cid2];
357                 AA[tt][0] = coords[lid2]; AA[tt][1] = coords[data_stride + lid2]; AA[tt][2] = 1.0;
358                 clids[tt] = cid2; /* store for interp */
359               }
360 
361               for (tt=0;tt<3;tt++) alpha[tt] = (PetscScalar)fcoord[tt];
362 
363               /* SUBROUTINE DGESV(N, NRHS, A, LDA, IPIV, B, LDB, INFO) */
364               LAPACKgesv_(&N, &NRHS, (PetscScalar*)AA, &LDA, IPIV, alpha, &LDB, &INFO);
365               {
366                 PetscBool have=PETSC_TRUE;  PetscReal lowest=1.e10;
367                 for (tt = 0, idx = 0 ; tt < 3 ; tt++) {
368                   if (PetscRealPart(alpha[tt]) > (1.0+EPS) || PetscRealPart(alpha[tt]) < -EPS) have = PETSC_FALSE;
369                   if (PetscRealPart(alpha[tt]) < lowest){
370                     lowest = PetscRealPart(alpha[tt]);
371                     idx = tt;
372                   }
373                 }
374                 haveit = have;
375               }
376               tid = mid.neighborlist[3*tid + idx];
377             }
378 
379             if (!haveit) {
380               /* brute force */
381               for (tid=0 ; tid<mid.numberoftriangles && !haveit ; tid++){
382                 for (tt=0;tt<3;tt++){
383                   PetscInt cid2 = mid.trianglelist[3*tid + tt];
384                   PetscInt lid2 = selected_idx_2[cid2];
385                   AA[tt][0] = coords[lid2]; AA[tt][1] = coords[data_stride + lid2]; AA[tt][2] = 1.0;
386                   clids[tt] = cid2; /* store for interp */
387                 }
388                 for (tt=0;tt<3;tt++) alpha[tt] = fcoord[tt];
389                 /* SUBROUTINE DGESV(N, NRHS, A, LDA, IPIV, B, LDB, INFO) */
390                 LAPACKgesv_(&N, &NRHS, (PetscScalar*)AA, &LDA, IPIV, alpha, &LDB, &INFO);
391                 {
392                   PetscBool have=PETSC_TRUE;  PetscReal worst=0.0, v;
393                   for (tt=0; tt<3 && have ;tt++) {
394                     if (PetscRealPart(alpha[tt]) > 1.0+EPS || PetscRealPart(alpha[tt]) < -EPS) have=PETSC_FALSE;
395                     if ((v=PetscAbs(PetscRealPart(alpha[tt])-0.5)) > worst) worst = v;
396                   }
397                   if (worst < best_alpha) {
398                     best_alpha = worst; bestTID = tid;
399                   }
400                   haveit = have;
401                 }
402               }
403             }
404             if (!haveit) {
405               if (best_alpha > *a_worst_best) *a_worst_best = best_alpha;
406               /* use best one */
407               for (tt=0;tt<3;tt++){
408                 PetscInt cid2 = mid.trianglelist[3*bestTID + tt];
409                 PetscInt lid2 = selected_idx_2[cid2];
410                 AA[tt][0] = coords[lid2]; AA[tt][1] = coords[data_stride + lid2]; AA[tt][2] = 1.0;
411                 clids[tt] = cid2; /* store for interp */
412               }
413               for (tt=0;tt<3;tt++) alpha[tt] = fcoord[tt];
414               /* SUBROUTINE DGESV(N, NRHS, A, LDA, IPIV, B, LDB, INFO) */
415               LAPACKgesv_(&N, &NRHS, (PetscScalar*)AA, &LDA, IPIV, alpha, &LDB, &INFO);
416             }
417 
418             /* put in row of P */
419             for (idx=0;idx<3;idx++){
420               PetscScalar shp = alpha[idx];
421               if (PetscAbs(PetscRealPart(shp)) > 1.e-6) {
422                 PetscInt cgid = crsGID[clids[idx]];
423                 PetscInt jj = cgid*bs, ii = fgid*bs; /* need to gloalize */
424                 for (tt=0 ; tt < bs ; tt++, ii++, jj++){
425                   ierr = MatSetValues(a_Prol,1,&ii,1,&jj,&shp,INSERT_VALUES);CHKERRQ(ierr);
426                 }
427               }
428             }
429           }
430         } /* aggregates iterations */
431         clid++;
432       } /* a coarse agg */
433     } /* for all fine nodes */
434 
435     ierr = ISRestoreIndices(selected_2, &selected_idx_2);CHKERRQ(ierr);
436     ierr = MatAssemblyBegin(a_Prol,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
437     ierr = MatAssemblyEnd(a_Prol,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
438 
439     ierr = PetscFree(node_tri);CHKERRQ(ierr);
440     ierr = PetscFree(nTri);CHKERRQ(ierr);
441   }
442 #if defined PETSC_GAMG_USE_LOG
443   ierr = PetscLogEventEnd(petsc_gamg_setup_events[FIND_V],0,0,0,0);CHKERRQ(ierr);
444 #endif
445   free(mid.trianglelist);
446   free(mid.neighborlist);
447   ierr = PetscFree(in.pointlist);CHKERRQ(ierr);
448 
449   PetscFunctionReturn(0);
450 #else
451   SETERRQ(((PetscObject)a_Prol)->comm,PETSC_ERR_PLIB,"configure with TRIANGLE to use geometric MG");
452 #endif
453 }
454 /* -------------------------------------------------------------------------- */
455 /*
456    getGIDsOnSquareGraph - square graph, get
457 
458    Input Parameter:
459    . nselected_1 - selected local indices (includes ghosts in input Gmat1)
460    . clid_lid_1 - [nselected_1] lids of selected nodes
461    . Gmat1 - graph that goes with 'selected_1'
462    Output Parameter:
463    . a_selected_2 - selected local indices (includes ghosts in output a_Gmat_2)
464    . a_Gmat_2 - graph that is squared of 'Gmat_1'
465    . a_crsGID[a_selected_2.size()] - map of global IDs of coarse grid nodes
466 */
467 #undef __FUNCT__
468 #define __FUNCT__ "getGIDsOnSquareGraph"
469 static PetscErrorCode getGIDsOnSquareGraph(const PetscInt nselected_1,
470                                             const PetscInt clid_lid_1[],
471                                             const Mat Gmat1,
472                                             IS *a_selected_2,
473                                             Mat *a_Gmat_2,
474                                             PetscInt **a_crsGID
475                                            )
476 {
477   PetscErrorCode ierr;
478   PetscMPIInt    mype,npe;
479   PetscInt       *crsGID, kk,my0,Iend,nloc;
480   MPI_Comm       wcomm = ((PetscObject)Gmat1)->comm;
481 
482   PetscFunctionBegin;
483   ierr = MPI_Comm_rank(wcomm,&mype);CHKERRQ(ierr);
484   ierr = MPI_Comm_size(wcomm,&npe);CHKERRQ(ierr);
485   ierr = MatGetOwnershipRange(Gmat1,&my0,&Iend);CHKERRQ(ierr); /* AIJ */
486   nloc = Iend - my0; /* this does not change */
487 
488   if (npe == 1) { /* not much to do in serial */
489     ierr = PetscMalloc(nselected_1*sizeof(PetscInt), &crsGID);CHKERRQ(ierr);
490     for (kk=0;kk<nselected_1;kk++) crsGID[kk] = kk;
491     *a_Gmat_2 = 0;
492     ierr = ISCreateGeneral(PETSC_COMM_SELF,nselected_1,clid_lid_1,PETSC_COPY_VALUES,a_selected_2);CHKERRQ(ierr);
493   } else {
494     PetscInt      idx,num_fine_ghosts,num_crs_ghost,myCrs0;
495     Mat_MPIAIJ   *mpimat2;
496     Mat           Gmat2;
497     Vec           locState;
498     PetscScalar   *cpcol_state;
499 
500     /* scan my coarse zero gid, set 'lid_state' with coarse GID */
501     kk = nselected_1;
502     MPI_Scan(&kk, &myCrs0, 1, MPIU_INT, MPIU_SUM, wcomm);
503     myCrs0 -= nselected_1;
504 
505     if (a_Gmat_2) { /* output */
506       /* grow graph to get wider set of selected vertices to cover fine grid, invalidates 'llist' */
507       ierr = MatTransposeMatMult(Gmat1, Gmat1, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &Gmat2);CHKERRQ(ierr);
508       *a_Gmat_2 = Gmat2; /* output */
509     } else Gmat2 = Gmat1;  /* use local to get crsGIDs at least */
510     /* get coarse grid GIDS for selected (locals and ghosts) */
511     mpimat2 = (Mat_MPIAIJ*)Gmat2->data;
512     ierr = MatGetVecs(Gmat2, &locState, 0);CHKERRQ(ierr);
513     ierr = VecSet(locState, (PetscScalar)(PetscReal)(-1));CHKERRQ(ierr); /* set with UNKNOWN state */
514     for (kk=0;kk<nselected_1;kk++){
515       PetscInt fgid = clid_lid_1[kk] + my0;
516       PetscScalar v = (PetscScalar)(kk+myCrs0);
517       ierr = VecSetValues(locState, 1, &fgid, &v, INSERT_VALUES);CHKERRQ(ierr); /* set with PID */
518     }
519     ierr = VecAssemblyBegin(locState);CHKERRQ(ierr);
520     ierr = VecAssemblyEnd(locState);CHKERRQ(ierr);
521     ierr = VecScatterBegin(mpimat2->Mvctx,locState,mpimat2->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
522     ierr =   VecScatterEnd(mpimat2->Mvctx,locState,mpimat2->lvec,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
523     ierr = VecGetLocalSize(mpimat2->lvec, &num_fine_ghosts);CHKERRQ(ierr);
524     ierr = VecGetArray(mpimat2->lvec, &cpcol_state);CHKERRQ(ierr);
525     for (kk=0,num_crs_ghost=0;kk<num_fine_ghosts;kk++){
526       if ((PetscInt)PetscRealPart(cpcol_state[kk]) != -1) num_crs_ghost++;
527     }
528     ierr = PetscMalloc((nselected_1+num_crs_ghost)*sizeof(PetscInt), &crsGID);CHKERRQ(ierr); /* output */
529     {
530       PetscInt *selected_set;
531       ierr = PetscMalloc((nselected_1+num_crs_ghost)*sizeof(PetscInt), &selected_set);CHKERRQ(ierr);
532       /* do ghost of 'crsGID' */
533       for (kk=0,idx=nselected_1;kk<num_fine_ghosts;kk++){
534         if ((PetscInt)PetscRealPart(cpcol_state[kk]) != -1){
535           PetscInt cgid = (PetscInt)PetscRealPart(cpcol_state[kk]);
536           selected_set[idx] = nloc + kk;
537           crsGID[idx++] = cgid;
538         }
539       }
540       assert(idx==(nselected_1+num_crs_ghost));
541       ierr = VecRestoreArray(mpimat2->lvec, &cpcol_state);CHKERRQ(ierr);
542       /* do locals in 'crsGID' */
543       ierr = VecGetArray(locState, &cpcol_state);CHKERRQ(ierr);
544       for (kk=0,idx=0;kk<nloc;kk++){
545         if ((PetscInt)PetscRealPart(cpcol_state[kk]) != -1){
546           PetscInt cgid = (PetscInt)PetscRealPart(cpcol_state[kk]);
547           selected_set[idx] = kk;
548           crsGID[idx++] = cgid;
549         }
550       }
551       assert(idx==nselected_1);
552       ierr = VecRestoreArray(locState, &cpcol_state);CHKERRQ(ierr);
553 
554       if (a_selected_2 != 0) { /* output */
555         ierr = ISCreateGeneral(PETSC_COMM_SELF,(nselected_1+num_crs_ghost),selected_set,PETSC_OWN_POINTER,a_selected_2);CHKERRQ(ierr);
556       } else {
557         ierr = PetscFree(selected_set);CHKERRQ(ierr);
558       }
559     }
560     ierr = VecDestroy(&locState);CHKERRQ(ierr);
561   }
562   *a_crsGID = crsGID; /* output */
563 
564   PetscFunctionReturn(0);
565 }
566 
567 /* -------------------------------------------------------------------------- */
568 /*
569    PCGAMGgraph_GEO
570 
571   Input Parameter:
572    . pc - this
573    . Amat - matrix on this fine level
574   Output Parameter:
575    . a_Gmat
576 */
577 #undef __FUNCT__
578 #define __FUNCT__ "PCGAMGgraph_GEO"
579 PetscErrorCode PCGAMGgraph_GEO(PC pc,
580                                 const Mat Amat,
581                                 Mat *a_Gmat
582                                )
583 {
584   PetscErrorCode ierr;
585   PC_MG          *mg = (PC_MG*)pc->data;
586   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
587   const PetscInt verbose = pc_gamg->verbose;
588   const PetscReal vfilter = pc_gamg->threshold;
589   PetscMPIInt    mype,npe;
590   MPI_Comm       wcomm = ((PetscObject)Amat)->comm;
591   Mat            Gmat;
592   PetscBool  set,flg,symm;
593   PetscFunctionBegin;
594 #if defined PETSC_USE_LOG
595   ierr = PetscLogEventBegin(PC_GAMGGgraph_GEO,0,0,0,0);CHKERRQ(ierr);
596 #endif
597   ierr = MPI_Comm_rank(wcomm, &mype);CHKERRQ(ierr);
598   ierr = MPI_Comm_size(wcomm, &npe);CHKERRQ(ierr);
599 
600   ierr = MatIsSymmetricKnown(Amat, &set, &flg);CHKERRQ(ierr);
601   symm = (PetscBool)!(set && flg);
602 
603   ierr  = PCGAMGCreateGraph(Amat, &Gmat);CHKERRQ(ierr);
604   ierr  = PCGAMGFilterGraph(&Gmat, vfilter, symm, verbose);CHKERRQ(ierr);
605 
606   *a_Gmat = Gmat;
607 #if defined PETSC_USE_LOG
608   ierr = PetscLogEventEnd(PC_GAMGGgraph_GEO,0,0,0,0);CHKERRQ(ierr);
609 #endif
610   PetscFunctionReturn(0);
611 }
612 
613 /* -------------------------------------------------------------------------- */
614 /*
615    PCGAMGcoarsen_GEO
616 
617   Input Parameter:
618    . a_pc - this
619    . a_Gmat - graph
620   Output Parameter:
621    . a_llist_parent - linked list from selected indices for data locality only
622 */
623 #undef __FUNCT__
624 #define __FUNCT__ "PCGAMGcoarsen_GEO"
625 PetscErrorCode PCGAMGcoarsen_GEO(PC a_pc,
626                                   Mat *a_Gmat,
627                                   PetscCoarsenData **a_llist_parent
628                                  )
629 {
630   PetscErrorCode ierr;
631   PC_MG          *mg = (PC_MG*)a_pc->data;
632   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
633   PetscInt       Istart,Iend,nloc,kk,Ii,ncols;
634   PetscMPIInt    mype,npe;
635   IS             perm;
636   GAMGNode *gnodes;
637   PetscInt *permute;
638   Mat       Gmat = *a_Gmat;
639   MPI_Comm  wcomm = ((PetscObject)Gmat)->comm;
640   MatCoarsen crs;
641 
642   PetscFunctionBegin;
643 #if defined PETSC_USE_LOG
644   ierr = PetscLogEventBegin(PC_GAMGCoarsen_GEO,0,0,0,0);CHKERRQ(ierr);
645 #endif
646   ierr = MPI_Comm_rank(wcomm, &mype);CHKERRQ(ierr);
647   ierr = MPI_Comm_size(wcomm, &npe);CHKERRQ(ierr);
648   ierr = MatGetOwnershipRange(Gmat, &Istart, &Iend);CHKERRQ(ierr);
649   nloc = (Iend-Istart);
650 
651   /* create random permutation with sort for geo-mg */
652   ierr = PetscMalloc(nloc*sizeof(GAMGNode), &gnodes);CHKERRQ(ierr);
653   ierr = PetscMalloc(nloc*sizeof(PetscInt), &permute);CHKERRQ(ierr);
654 
655   for (Ii=Istart; Ii<Iend; Ii++) { /* locals only? */
656     ierr = MatGetRow(Gmat,Ii,&ncols,0,0);CHKERRQ(ierr);
657     {
658       PetscInt lid = Ii - Istart;
659       gnodes[lid].lid = lid;
660       gnodes[lid].degree = ncols;
661     }
662     ierr = MatRestoreRow(Gmat,Ii,&ncols,0,0);CHKERRQ(ierr);
663   }
664   /* randomize */
665   srand(1); /* make deterministic */
666   if (PETSC_TRUE) {
667     PetscBool *bIndexSet;
668     ierr = PetscMalloc(nloc*sizeof(PetscBool), &bIndexSet);CHKERRQ(ierr);
669     for (Ii = 0; Ii < nloc ; Ii++) bIndexSet[Ii] = PETSC_FALSE;
670     for (Ii = 0; Ii < nloc ; Ii++)
671     {
672       PetscInt iSwapIndex = rand()%nloc;
673       if (!bIndexSet[iSwapIndex] && iSwapIndex != Ii)
674       {
675         GAMGNode iTemp = gnodes[iSwapIndex];
676         gnodes[iSwapIndex] = gnodes[Ii];
677         gnodes[Ii] = iTemp;
678         bIndexSet[Ii] = PETSC_TRUE;
679         bIndexSet[iSwapIndex] = PETSC_TRUE;
680       }
681     }
682     ierr = PetscFree(bIndexSet);CHKERRQ(ierr);
683   }
684   /* only sort locals */
685   qsort(gnodes, nloc, sizeof(GAMGNode), petsc_geo_mg_compare);
686   /* create IS of permutation */
687   for (kk=0;kk<nloc;kk++) { /* locals only */
688     permute[kk] = gnodes[kk].lid;
689   }
690   ierr = ISCreateGeneral(PETSC_COMM_SELF, nloc, permute, PETSC_OWN_POINTER, &perm);CHKERRQ(ierr);
691 
692   ierr = PetscFree(gnodes);CHKERRQ(ierr);
693 
694   /* get MIS aggs */
695 
696   ierr = MatCoarsenCreate(wcomm, &crs);CHKERRQ(ierr);
697   ierr = MatCoarsenSetType(crs, MATCOARSENMIS);CHKERRQ(ierr);
698   ierr = MatCoarsenSetGreedyOrdering(crs, perm);CHKERRQ(ierr);
699   ierr = MatCoarsenSetAdjacency(crs, Gmat);CHKERRQ(ierr);
700   ierr = MatCoarsenSetVerbose(crs, pc_gamg->verbose);CHKERRQ(ierr);
701   ierr = MatCoarsenSetStrictAggs(crs, PETSC_FALSE);CHKERRQ(ierr);
702   ierr = MatCoarsenApply(crs);CHKERRQ(ierr);
703   ierr = MatCoarsenGetData(crs, a_llist_parent);CHKERRQ(ierr);
704   ierr = MatCoarsenDestroy(&crs);CHKERRQ(ierr);
705 
706   ierr = ISDestroy(&perm);CHKERRQ(ierr);
707 #if defined PETSC_USE_LOG
708   ierr = PetscLogEventEnd(PC_GAMGCoarsen_GEO,0,0,0,0);CHKERRQ(ierr);
709 #endif
710   PetscFunctionReturn(0);
711 }
712 
713 /* -------------------------------------------------------------------------- */
714 /*
715  PCGAMGProlongator_GEO
716 
717  Input Parameter:
718  . pc - this
719  . Amat - matrix on this fine level
720  . Graph - used to get ghost data for nodes in
721  . selected_1 - [nselected]
722  . agg_lists - [nselected]
723  Output Parameter:
724  . a_P_out - prolongation operator to the next level
725  */
726 #undef __FUNCT__
727 #define __FUNCT__ "PCGAMGProlongator_GEO"
728 PetscErrorCode PCGAMGProlongator_GEO(PC pc,
729                                       const Mat Amat,
730                                       const Mat Gmat,
731                                       PetscCoarsenData *agg_lists,
732                                       Mat *a_P_out
733                                      )
734 {
735   PC_MG          *mg = (PC_MG*)pc->data;
736   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
737   const PetscInt  verbose = pc_gamg->verbose;
738   const PetscInt  dim = pc_gamg->data_cell_cols, data_cols = pc_gamg->data_cell_cols;
739   PetscErrorCode ierr;
740   PetscInt       Istart,Iend,nloc,my0,jj,kk,ncols,nLocalSelected,bs,*clid_flid;
741   Mat            Prol;
742   PetscMPIInt    mype, npe;
743   MPI_Comm       wcomm = ((PetscObject)Amat)->comm;
744   IS             selected_2,selected_1;
745   const PetscInt *selected_idx;
746 
747   PetscFunctionBegin;
748 #if defined PETSC_USE_LOG
749   ierr = PetscLogEventBegin(PC_GAMGProlongator_GEO,0,0,0,0);CHKERRQ(ierr);
750 #endif
751   ierr = MPI_Comm_rank(wcomm,&mype);CHKERRQ(ierr);
752   ierr = MPI_Comm_size(wcomm,&npe);CHKERRQ(ierr);
753   ierr = MatGetOwnershipRange(Amat, &Istart, &Iend);CHKERRQ(ierr);
754   ierr = MatGetBlockSize(Amat, &bs);CHKERRQ(ierr);
755   nloc = (Iend-Istart)/bs; my0 = Istart/bs; assert((Iend-Istart)%bs==0);
756 
757   /* get 'nLocalSelected' */
758   ierr = PetscCDGetMIS(agg_lists, &selected_1);CHKERRQ(ierr);
759   ierr = ISGetSize(selected_1, &jj);CHKERRQ(ierr);
760   ierr = PetscMalloc(jj*sizeof(PetscInt), &clid_flid);CHKERRQ(ierr);
761   ierr = ISGetIndices(selected_1, &selected_idx);CHKERRQ(ierr);
762   for (kk=0,nLocalSelected=0;kk<jj;kk++) {
763     PetscInt lid = selected_idx[kk];
764     if (lid<nloc) {
765       ierr = MatGetRow(Gmat,lid+my0,&ncols,0,0);CHKERRQ(ierr);
766       if (ncols>1) { /* fiter out singletons */
767         clid_flid[nLocalSelected++] = lid;
768       } else assert(0); /* filtered in coarsening */
769       ierr = MatRestoreRow(Gmat,lid+my0,&ncols,0,0);CHKERRQ(ierr);
770     }
771   }
772   ierr = ISRestoreIndices(selected_1, &selected_idx);CHKERRQ(ierr);
773   ierr = ISDestroy(&selected_1);CHKERRQ(ierr); /* this is selected_1 in serial */
774 
775   /* create prolongator, create P matrix */
776   ierr = MatCreate(wcomm, &Prol);CHKERRQ(ierr);
777   ierr = MatSetSizes(Prol,nloc*bs,nLocalSelected*bs,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
778   ierr = MatSetBlockSizes(Prol, bs, bs);CHKERRQ(ierr);
779   ierr = MatSetType(Prol, MATAIJ);CHKERRQ(ierr);
780   ierr = MatSeqAIJSetPreallocation(Prol,3*data_cols,PETSC_NULL);CHKERRQ(ierr);
781   ierr = MatMPIAIJSetPreallocation(Prol,3*data_cols,PETSC_NULL,3*data_cols,PETSC_NULL);CHKERRQ(ierr);
782   /* ierr = MatCreateAIJ(wcomm,  */
783   /*                      nloc*bs, nLocalSelected*bs, */
784   /*                      PETSC_DETERMINE, PETSC_DETERMINE, */
785   /*                      3*data_cols, PETSC_NULL,  */
786   /*                      3*data_cols, PETSC_NULL, */
787   /*                      &Prol); */
788   /* CHKERRQ(ierr); */
789 
790   /* can get all points "removed" - but not on geomg */
791   ierr =  MatGetSize(Prol, &kk, &jj);CHKERRQ(ierr);
792   if (jj==0) {
793     if (verbose) {
794       PetscPrintf(wcomm,"[%d]%s ERROE: no selected points on coarse grid\n",mype,__FUNCT__);
795     }
796     ierr = PetscFree(clid_flid);CHKERRQ(ierr);
797     ierr = MatDestroy(&Prol);CHKERRQ(ierr);
798     *a_P_out = PETSC_NULL;  /* out */
799     PetscFunctionReturn(0);
800   }
801 
802   {
803     PetscReal *coords;
804     PetscInt   data_stride;
805     PetscInt  *crsGID = PETSC_NULL;
806     Mat        Gmat2;
807 
808     assert(dim==data_cols);
809     /* grow ghost data for better coarse grid cover of fine grid */
810 #if defined PETSC_GAMG_USE_LOG
811     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET5],0,0,0,0);CHKERRQ(ierr);
812 #endif
813     /* messy method, squares graph and gets some data */
814     ierr = getGIDsOnSquareGraph(nLocalSelected, clid_flid, Gmat, &selected_2, &Gmat2, &crsGID);CHKERRQ(ierr);
815     /* llist is now not valid wrt squared graph, but will work as iterator in 'triangulateAndFormProl' */
816 #if defined PETSC_GAMG_USE_LOG
817     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET5],0,0,0,0);CHKERRQ(ierr);
818 #endif
819     /* create global vector of coorindates in 'coords' */
820     if (npe > 1) {
821       ierr = PCGAMGGetDataWithGhosts(Gmat2, dim, pc_gamg->data, &data_stride, &coords);CHKERRQ(ierr);
822     } else {
823       coords = (PetscReal*)pc_gamg->data;
824       data_stride = pc_gamg->data_sz/pc_gamg->data_cell_cols;
825     }
826     ierr = MatDestroy(&Gmat2);CHKERRQ(ierr);
827 
828     /* triangulate */
829     if (dim == 2) {
830       PetscReal metric,tm;
831 #if defined PETSC_GAMG_USE_LOG
832       ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET6],0,0,0,0);CHKERRQ(ierr);
833 #endif
834       ierr = triangulateAndFormProl(selected_2, data_stride, coords,nLocalSelected, clid_flid, agg_lists, crsGID, bs, Prol, &metric);CHKERRQ(ierr);
835 #if defined PETSC_GAMG_USE_LOG
836       ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET6],0,0,0,0);CHKERRQ(ierr);
837 #endif
838       ierr = PetscFree(crsGID);CHKERRQ(ierr);
839 
840       /* clean up and create coordinates for coarse grid (output) */
841       if (npe > 1) ierr = PetscFree(coords);CHKERRQ(ierr);
842 
843       ierr = MPI_Allreduce(&metric, &tm, 1, MPIU_REAL, MPIU_MAX, wcomm);CHKERRQ(ierr);
844       if (tm > 1.) { /* needs to be globalized - should not happen */
845         if (verbose) {
846           PetscPrintf(wcomm,"[%d]%s failed metric for coarse grid %e\n",mype,__FUNCT__,tm);
847         }
848         ierr = MatDestroy(&Prol);CHKERRQ(ierr);
849         Prol = PETSC_NULL;
850       } else if (metric > .0) {
851         if (verbose) {
852           PetscPrintf(wcomm,"[%d]%s worst metric for coarse grid = %e\n",mype,__FUNCT__,metric);
853         }
854       }
855     } else {
856       SETERRQ(wcomm,PETSC_ERR_PLIB,"3D not implemented for 'geo' AMG");
857     }
858     { /* create next coords - output */
859       PetscReal *crs_crds;
860       ierr = PetscMalloc(dim*nLocalSelected*sizeof(PetscReal), &crs_crds);CHKERRQ(ierr);
861       for (kk=0;kk<nLocalSelected;kk++){/* grab local select nodes to promote - output */
862         PetscInt lid = clid_flid[kk];
863         for (jj=0;jj<dim;jj++) crs_crds[jj*nLocalSelected + kk] = pc_gamg->data[jj*nloc + lid];
864       }
865 
866       ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
867       pc_gamg->data = crs_crds; /* out */
868       pc_gamg->data_sz = dim*nLocalSelected;
869     }
870     ierr = ISDestroy(&selected_2);CHKERRQ(ierr);
871   }
872 
873   *a_P_out = Prol;  /* out */
874   ierr = PetscFree(clid_flid);CHKERRQ(ierr);
875 #if defined PETSC_USE_LOG
876   ierr = PetscLogEventEnd(PC_GAMGProlongator_GEO,0,0,0,0);CHKERRQ(ierr);
877 #endif
878   PetscFunctionReturn(0);
879 }
880 
881 /* -------------------------------------------------------------------------- */
882 /*
883  PCCreateGAMG_GEO
884 
885   Input Parameter:
886    . pc -
887 */
888 #undef __FUNCT__
889 #define __FUNCT__ "PCCreateGAMG_GEO"
890 PetscErrorCode  PCCreateGAMG_GEO(PC pc)
891 {
892   PetscErrorCode  ierr;
893   PC_MG           *mg = (PC_MG*)pc->data;
894   PC_GAMG         *pc_gamg = (PC_GAMG*)mg->innerctx;
895 
896   PetscFunctionBegin;
897   pc->ops->setfromoptions = PCSetFromOptions_GEO;
898   /* pc->ops->destroy        = PCDestroy_GEO; */
899   /* reset does not do anything; setup not virtual */
900 
901   /* set internal function pointers */
902   pc_gamg->graph = PCGAMGgraph_GEO;
903   pc_gamg->coarsen = PCGAMGcoarsen_GEO;
904   pc_gamg->prolongator = PCGAMGProlongator_GEO;
905   pc_gamg->optprol = 0;
906   pc_gamg->formkktprol = 0;
907 
908   pc_gamg->createdefaultdata = PCSetData_GEO;
909 
910   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,
911                                             "PCSetCoordinates_C",
912                                             "PCSetCoordinates_GEO",
913                                             PCSetCoordinates_GEO);CHKERRQ(ierr);
914 
915   PetscFunctionReturn(0);
916 }
917