Actual source code: virs.c

petsc-3.15.0 2021-04-05
Report Typos and Errors

  2: #include <../src/snes/impls/vi/rs/virsimpl.h>
  3: #include <petsc/private/dmimpl.h>
  4: #include <petsc/private/vecimpl.h>

  6: /*
  7:    SNESVIGetInactiveSet - Gets the global indices for the inactive set variables (these correspond to the degrees of freedom the linear
  8:      system is solved on)

 10:    Input parameter:
 11: .  snes - the SNES context

 13:    Output parameter:
 14: .  inact - inactive set index set

 16:  */
 17: PetscErrorCode SNESVIGetInactiveSet(SNES snes,IS *inact)
 18: {
 19:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*)snes->data;

 22:   *inact = vi->IS_inact;
 23:   return(0);
 24: }

 26: /*
 27:     Provides a wrapper to a DM to allow it to be used to generated the interpolation/restriction from the DM for the smaller matrices and vectors
 28:   defined by the reduced space method.

 30:     Simple calls the regular DM interpolation and restricts it to operation on the variables not associated with active constraints.

 32: <*/
 33: typedef struct {
 34:   PetscInt n;                                              /* size of vectors in the reduced DM space */
 35:   IS       inactive;

 37:   PetscErrorCode (*createinterpolation)(DM,DM,Mat*,Vec*);  /* DM's original routines */
 38:   PetscErrorCode (*coarsen)(DM, MPI_Comm, DM*);
 39:   PetscErrorCode (*createglobalvector)(DM,Vec*);
 40:   PetscErrorCode (*createinjection)(DM,DM,Mat*);
 41:   PetscErrorCode (*hascreateinjection)(DM,PetscBool*);

 43:   DM dm;                                                  /* when destroying this object we need to reset the above function into the base DM */
 44: } DM_SNESVI;

 46: /*
 47:      DMCreateGlobalVector_SNESVI - Creates global vector of the size of the reduced space

 49: */
 50: PetscErrorCode  DMCreateGlobalVector_SNESVI(DM dm,Vec *vec)
 51: {
 53:   PetscContainer isnes;
 54:   DM_SNESVI      *dmsnesvi;

 57:   PetscObjectQuery((PetscObject)dm,"VI",(PetscObject*)&isnes);
 58:   if (!isnes) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_PLIB,"Composed SNES is missing");
 59:   PetscContainerGetPointer(isnes,(void**)&dmsnesvi);
 60:   VecCreateMPI(PetscObjectComm((PetscObject)dm),dmsnesvi->n,PETSC_DETERMINE,vec);
 61:   VecSetDM(*vec, dm);
 62:   return(0);
 63: }

 65: /*
 66:      DMCreateInterpolation_SNESVI - Modifieds the interpolation obtained from the DM by removing all rows and columns associated with active constraints.

 68: */
 69: PetscErrorCode  DMCreateInterpolation_SNESVI(DM dm1,DM dm2,Mat *mat,Vec *vec)
 70: {
 72:   PetscContainer isnes;
 73:   DM_SNESVI      *dmsnesvi1,*dmsnesvi2;
 74:   Mat            interp;

 77:   PetscObjectQuery((PetscObject)dm1,"VI",(PetscObject*)&isnes);
 78:   if (!isnes) SETERRQ(PetscObjectComm((PetscObject)dm1),PETSC_ERR_PLIB,"Composed VI data structure is missing");
 79:   PetscContainerGetPointer(isnes,(void**)&dmsnesvi1);
 80:   PetscObjectQuery((PetscObject)dm2,"VI",(PetscObject*)&isnes);
 81:   if (!isnes) SETERRQ(PetscObjectComm((PetscObject)dm2),PETSC_ERR_PLIB,"Composed VI data structure is missing");
 82:   PetscContainerGetPointer(isnes,(void**)&dmsnesvi2);

 84:   (*dmsnesvi1->createinterpolation)(dm1,dm2,&interp,NULL);
 85:   MatCreateSubMatrix(interp,dmsnesvi2->inactive,dmsnesvi1->inactive,MAT_INITIAL_MATRIX,mat);
 86:   MatDestroy(&interp);
 87:   *vec = NULL;
 88:   return(0);
 89: }

 91: static PetscErrorCode DMSetVI(DM,IS);
 92: static PetscErrorCode DMDestroyVI(DM);

 94: /*
 95:      DMCoarsen_SNESVI - Computes the regular coarsened DM then computes additional information about its inactive set

 97: */
 98: PetscErrorCode  DMCoarsen_SNESVI(DM dm1,MPI_Comm comm,DM *dm2)
 99: {
101:   PetscContainer isnes;
102:   DM_SNESVI      *dmsnesvi1;
103:   Vec            finemarked,coarsemarked;
104:   IS             inactive;
105:   Mat            inject;
106:   const PetscInt *index;
107:   PetscInt       n,k,cnt = 0,rstart,*coarseindex;
108:   PetscScalar    *marked;

111:   PetscObjectQuery((PetscObject)dm1,"VI",(PetscObject*)&isnes);
112:   if (!isnes) SETERRQ(PetscObjectComm((PetscObject)dm1),PETSC_ERR_PLIB,"Composed VI data structure is missing");
113:   PetscContainerGetPointer(isnes,(void**)&dmsnesvi1);

115:   /* get the original coarsen */
116:   (*dmsnesvi1->coarsen)(dm1,comm,dm2);

118:   /* not sure why this extra reference is needed, but without the dm2 disappears too early */
119:   /* Updating the KSPCreateVecs() to avoid using DMGetGlobalVector() when matrix is available removes the need for this reference? */
120:   /*  PetscObjectReference((PetscObject)*dm2);*/

122:   /* need to set back global vectors in order to use the original injection */
123:   DMClearGlobalVectors(dm1);

125:   dm1->ops->createglobalvector = dmsnesvi1->createglobalvector;

127:   DMCreateGlobalVector(dm1,&finemarked);
128:   DMCreateGlobalVector(*dm2,&coarsemarked);

130:   /*
131:      fill finemarked with locations of inactive points
132:   */
133:   ISGetIndices(dmsnesvi1->inactive,&index);
134:   ISGetLocalSize(dmsnesvi1->inactive,&n);
135:   VecSet(finemarked,0.0);
136:   for (k=0; k<n; k++) {
137:     VecSetValue(finemarked,index[k],1.0,INSERT_VALUES);
138:   }
139:   VecAssemblyBegin(finemarked);
140:   VecAssemblyEnd(finemarked);

142:   DMCreateInjection(*dm2,dm1,&inject);
143:   MatRestrict(inject,finemarked,coarsemarked);
144:   MatDestroy(&inject);

146:   /*
147:      create index set list of coarse inactive points from coarsemarked
148:   */
149:   VecGetLocalSize(coarsemarked,&n);
150:   VecGetOwnershipRange(coarsemarked,&rstart,NULL);
151:   VecGetArray(coarsemarked,&marked);
152:   for (k=0; k<n; k++) {
153:     if (marked[k] != 0.0) cnt++;
154:   }
155:   PetscMalloc1(cnt,&coarseindex);
156:   cnt  = 0;
157:   for (k=0; k<n; k++) {
158:     if (marked[k] != 0.0) coarseindex[cnt++] = k + rstart;
159:   }
160:   VecRestoreArray(coarsemarked,&marked);
161:   ISCreateGeneral(PetscObjectComm((PetscObject)coarsemarked),cnt,coarseindex,PETSC_OWN_POINTER,&inactive);

163:   DMClearGlobalVectors(dm1);

165:   dm1->ops->createglobalvector = DMCreateGlobalVector_SNESVI;

167:   DMSetVI(*dm2,inactive);

169:   VecDestroy(&finemarked);
170:   VecDestroy(&coarsemarked);
171:   ISDestroy(&inactive);
172:   return(0);
173: }

175: PetscErrorCode DMDestroy_SNESVI(DM_SNESVI *dmsnesvi)
176: {

180:   /* reset the base methods in the DM object that were changed when the DM_SNESVI was reset */
181:   dmsnesvi->dm->ops->createinterpolation = dmsnesvi->createinterpolation;
182:   dmsnesvi->dm->ops->coarsen             = dmsnesvi->coarsen;
183:   dmsnesvi->dm->ops->createglobalvector  = dmsnesvi->createglobalvector;
184:   dmsnesvi->dm->ops->createinjection     = dmsnesvi->createinjection;
185:   dmsnesvi->dm->ops->hascreateinjection  = dmsnesvi->hascreateinjection;
186:   /* need to clear out this vectors because some of them may not have a reference to the DM
187:     but they are counted as having references to the DM in DMDestroy() */
188:   DMClearGlobalVectors(dmsnesvi->dm);

190:   ISDestroy(&dmsnesvi->inactive);
191:   PetscFree(dmsnesvi);
192:   return(0);
193: }

195: /*
196:      DMSetVI - Marks a DM as associated with a VI problem. This causes the interpolation/restriction operators to
197:                be restricted to only those variables NOT associated with active constraints.

199: */
200: static PetscErrorCode DMSetVI(DM dm,IS inactive)
201: {
203:   PetscContainer isnes;
204:   DM_SNESVI      *dmsnesvi;

207:   if (!dm) return(0);

209:   PetscObjectReference((PetscObject)inactive);

211:   PetscObjectQuery((PetscObject)dm,"VI",(PetscObject*)&isnes);
212:   if (!isnes) {
213:     PetscContainerCreate(PetscObjectComm((PetscObject)dm),&isnes);
214:     PetscContainerSetUserDestroy(isnes,(PetscErrorCode (*)(void*))DMDestroy_SNESVI);
215:     PetscNew(&dmsnesvi);
216:     PetscContainerSetPointer(isnes,(void*)dmsnesvi);
217:     PetscObjectCompose((PetscObject)dm,"VI",(PetscObject)isnes);
218:     PetscContainerDestroy(&isnes);

220:     dmsnesvi->createinterpolation = dm->ops->createinterpolation;
221:     dm->ops->createinterpolation  = DMCreateInterpolation_SNESVI;
222:     dmsnesvi->coarsen             = dm->ops->coarsen;
223:     dm->ops->coarsen              = DMCoarsen_SNESVI;
224:     dmsnesvi->createglobalvector  = dm->ops->createglobalvector;
225:     dm->ops->createglobalvector   = DMCreateGlobalVector_SNESVI;
226:     dmsnesvi->createinjection     = dm->ops->createinjection;
227:     dm->ops->createinjection      = NULL;
228:     dmsnesvi->hascreateinjection  = dm->ops->hascreateinjection;
229:     dm->ops->hascreateinjection   = NULL;
230:   } else {
231:     PetscContainerGetPointer(isnes,(void**)&dmsnesvi);
232:     ISDestroy(&dmsnesvi->inactive);
233:   }
234:   DMClearGlobalVectors(dm);
235:   ISGetLocalSize(inactive,&dmsnesvi->n);

237:   dmsnesvi->inactive = inactive;
238:   dmsnesvi->dm       = dm;
239:   return(0);
240: }

242: /*
243:      DMDestroyVI - Frees the DM_SNESVI object contained in the DM
244:          - also resets the function pointers in the DM for createinterpolation() etc to use the original DM
245: */
246: static PetscErrorCode DMDestroyVI(DM dm)
247: {

251:   if (!dm) return(0);
252:   PetscObjectCompose((PetscObject)dm,"VI",(PetscObject)NULL);
253:   return(0);
254: }

256: /* --------------------------------------------------------------------------------------------------------*/


259: PetscErrorCode SNESCreateIndexSets_VINEWTONRSLS(SNES snes,Vec X,Vec F,IS *ISact,IS *ISinact)
260: {

264:   SNESVIGetActiveSetIS(snes,X,F,ISact);
265:   ISComplement(*ISact,X->map->rstart,X->map->rend,ISinact);
266:   return(0);
267: }

269: /* Create active and inactive set vectors. The local size of this vector is set and petsc computes the global size */
270: PetscErrorCode SNESCreateSubVectors_VINEWTONRSLS(SNES snes,PetscInt n,Vec *newv)
271: {
273:   Vec            v;

276:   VecCreate(PetscObjectComm((PetscObject)snes),&v);
277:   VecSetSizes(v,n,PETSC_DECIDE);
278:   VecSetType(v,VECSTANDARD);
279:   *newv = v;
280:   return(0);
281: }

283: /* Resets the snes PC and KSP when the active set sizes change */
284: PetscErrorCode SNESVIResetPCandKSP(SNES snes,Mat Amat,Mat Pmat)
285: {
287:   KSP            snesksp;

290:   SNESGetKSP(snes,&snesksp);
291:   KSPReset(snesksp);
292:   KSPResetFromOptions(snesksp);

294:   /*
295:   KSP                    kspnew;
296:   PC                     pcnew;
297:   MatSolverType          stype;


300:   KSPCreate(PetscObjectComm((PetscObject)snes),&kspnew);
301:   kspnew->pc_side = snesksp->pc_side;
302:   kspnew->rtol    = snesksp->rtol;
303:   kspnew->abstol    = snesksp->abstol;
304:   kspnew->max_it  = snesksp->max_it;
305:   KSPSetType(kspnew,((PetscObject)snesksp)->type_name);
306:   KSPGetPC(kspnew,&pcnew);
307:   PCSetType(kspnew->pc,((PetscObject)snesksp->pc)->type_name);
308:   PCSetOperators(kspnew->pc,Amat,Pmat);
309:   PCFactorGetMatSolverType(snesksp->pc,&stype);
310:   PCFactorSetMatSolverType(kspnew->pc,stype);
311:   KSPDestroy(&snesksp);
312:   snes->ksp = kspnew;
313:   PetscLogObjectParent((PetscObject)snes,(PetscObject)kspnew);
314:    KSPSetFromOptions(kspnew);*/
315:   return(0);
316: }

318: /* Variational Inequality solver using reduce space method. No semismooth algorithm is
319:    implemented in this algorithm. It basically identifies the active constraints and does
320:    a linear solve on the other variables (those not associated with the active constraints). */
321: PetscErrorCode SNESSolve_VINEWTONRSLS(SNES snes)
322: {
323:   SNES_VINEWTONRSLS    *vi = (SNES_VINEWTONRSLS*)snes->data;
324:   PetscErrorCode       ierr;
325:   PetscInt             maxits,i,lits;
326:   SNESLineSearchReason lssucceed;
327:   PetscReal            fnorm,gnorm,xnorm=0,ynorm;
328:   Vec                  Y,X,F;
329:   KSPConvergedReason   kspreason;
330:   KSP                  ksp;
331:   PC                   pc;

334:   /* Multigrid must use Galerkin for coarse grids with active set/reduced space methods; cannot rediscretize on coarser grids*/
335:   SNESGetKSP(snes,&ksp);
336:   KSPGetPC(ksp,&pc);
337:   PCMGSetGalerkin(pc,PC_MG_GALERKIN_BOTH);

339:   snes->numFailures            = 0;
340:   snes->numLinearSolveFailures = 0;
341:   snes->reason                 = SNES_CONVERGED_ITERATING;

343:   maxits = snes->max_its;               /* maximum number of iterations */
344:   X      = snes->vec_sol;               /* solution vector */
345:   F      = snes->vec_func;              /* residual vector */
346:   Y      = snes->work[0];               /* work vectors */

348:   SNESLineSearchSetVIFunctions(snes->linesearch, SNESVIProjectOntoBounds, SNESVIComputeInactiveSetFnorm);
349:   SNESLineSearchSetVecs(snes->linesearch, X, NULL, NULL, NULL, NULL);
350:   SNESLineSearchSetUp(snes->linesearch);

352:   PetscObjectSAWsTakeAccess((PetscObject)snes);
353:   snes->iter = 0;
354:   snes->norm = 0.0;
355:   PetscObjectSAWsGrantAccess((PetscObject)snes);

357:   SNESVIProjectOntoBounds(snes,X);
358:   SNESComputeFunction(snes,X,F);
359:   SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);
360:   VecNorm(X,NORM_2,&xnorm);        /* xnorm <- ||x||  */
361:   SNESCheckFunctionNorm(snes,fnorm);
362:   PetscObjectSAWsTakeAccess((PetscObject)snes);
363:   snes->norm = fnorm;
364:   PetscObjectSAWsGrantAccess((PetscObject)snes);
365:   SNESLogConvergenceHistory(snes,fnorm,0);
366:   SNESMonitor(snes,0,fnorm);

368:   /* test convergence */
369:   (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);
370:   if (snes->reason) return(0);


373:   for (i=0; i<maxits; i++) {

375:     IS         IS_act; /* _act -> active set _inact -> inactive set */
376:     IS         IS_redact; /* redundant active set */
377:     VecScatter scat_act,scat_inact;
378:     PetscInt   nis_act,nis_inact;
379:     Vec        Y_act,Y_inact,F_inact;
380:     Mat        jac_inact_inact,prejac_inact_inact;
381:     PetscBool  isequal;

383:     /* Call general purpose update function */
384:     if (snes->ops->update) {
385:       (*snes->ops->update)(snes, snes->iter);
386:     }
387:     SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);
388:     SNESCheckJacobianDomainerror(snes);

390:     /* Create active and inactive index sets */

392:     /*original
393:     SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&vi->IS_inact);
394:      */
395:     SNESVIGetActiveSetIS(snes,X,F,&IS_act);

397:     if (vi->checkredundancy) {
398:       (*vi->checkredundancy)(snes,IS_act,&IS_redact,vi->ctxP);
399:       if (IS_redact) {
400:         ISSort(IS_redact);
401:         ISComplement(IS_redact,X->map->rstart,X->map->rend,&vi->IS_inact);
402:         ISDestroy(&IS_redact);
403:       } else {
404:         ISComplement(IS_act,X->map->rstart,X->map->rend,&vi->IS_inact);
405:       }
406:     } else {
407:       ISComplement(IS_act,X->map->rstart,X->map->rend,&vi->IS_inact);
408:     }


411:     /* Create inactive set submatrix */
412:     MatCreateSubMatrix(snes->jacobian,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);

414:     if (0) {                    /* Dead code (temporary developer hack) */
415:       IS keptrows;
416:       MatFindNonzeroRows(jac_inact_inact,&keptrows);
417:       if (keptrows) {
418:         PetscInt       cnt,*nrows,k;
419:         const PetscInt *krows,*inact;
420:         PetscInt       rstart;

422:         MatGetOwnershipRange(jac_inact_inact,&rstart,NULL);
423:         MatDestroy(&jac_inact_inact);
424:         ISDestroy(&IS_act);

426:         ISGetLocalSize(keptrows,&cnt);
427:         ISGetIndices(keptrows,&krows);
428:         ISGetIndices(vi->IS_inact,&inact);
429:         PetscMalloc1(cnt,&nrows);
430:         for (k=0; k<cnt; k++) nrows[k] = inact[krows[k]-rstart];
431:         ISRestoreIndices(keptrows,&krows);
432:         ISRestoreIndices(vi->IS_inact,&inact);
433:         ISDestroy(&keptrows);
434:         ISDestroy(&vi->IS_inact);

436:         ISCreateGeneral(PetscObjectComm((PetscObject)snes),cnt,nrows,PETSC_OWN_POINTER,&vi->IS_inact);
437:         ISComplement(vi->IS_inact,F->map->rstart,F->map->rend,&IS_act);
438:         MatCreateSubMatrix(snes->jacobian,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);
439:       }
440:     }
441:     DMSetVI(snes->dm,vi->IS_inact);
442:     /* remove later */

444:     /*
445:     VecView(vi->xu,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xu))->comm));
446:     VecView(vi->xl,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xl))->comm));
447:     VecView(X,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)X)));
448:     VecView(F,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)F)));
449:     ISView(vi->IS_inact,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)vi->IS_inact)));
450:      */

452:     /* Get sizes of active and inactive sets */
453:     ISGetLocalSize(IS_act,&nis_act);
454:     ISGetLocalSize(vi->IS_inact,&nis_inact);

456:     /* Create active and inactive set vectors */
457:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&F_inact);
458:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_act,&Y_act);
459:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&Y_inact);

461:     /* Create scatter contexts */
462:     VecScatterCreate(Y,IS_act,Y_act,NULL,&scat_act);
463:     VecScatterCreate(Y,vi->IS_inact,Y_inact,NULL,&scat_inact);

465:     /* Do a vec scatter to active and inactive set vectors */
466:     VecScatterBegin(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);
467:     VecScatterEnd(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);

469:     VecScatterBegin(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);
470:     VecScatterEnd(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);

472:     VecScatterBegin(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);
473:     VecScatterEnd(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);

475:     /* Active set direction = 0 */
476:     VecSet(Y_act,0);
477:     if (snes->jacobian != snes->jacobian_pre) {
478:       MatCreateSubMatrix(snes->jacobian_pre,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&prejac_inact_inact);
479:     } else prejac_inact_inact = jac_inact_inact;

481:     ISEqual(vi->IS_inact_prev,vi->IS_inact,&isequal);
482:     if (!isequal) {
483:       SNESVIResetPCandKSP(snes,jac_inact_inact,prejac_inact_inact);
484:       PCFieldSplitRestrictIS(pc,vi->IS_inact);
485:     }

487:     /*      ISView(vi->IS_inact,0); */
488:     /*      ISView(IS_act,0);*/
489:     /*      MatView(snes->jacobian_pre,0); */



493:     KSPSetOperators(snes->ksp,jac_inact_inact,prejac_inact_inact);
494:     KSPSetUp(snes->ksp);
495:     {
496:       PC        pc;
497:       PetscBool flg;
498:       KSPGetPC(snes->ksp,&pc);
499:       PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);
500:       if (flg) {
501:         KSP *subksps;
502:         PCFieldSplitGetSubKSP(pc,NULL,&subksps);
503:         KSPGetPC(subksps[0],&pc);
504:         PetscFree(subksps);
505:         PetscObjectTypeCompare((PetscObject)pc,PCBJACOBI,&flg);
506:         if (flg) {
507:           PetscInt       n,N = 101*101,j,cnts[3] = {0,0,0};
508:           const PetscInt *ii;

510:           ISGetSize(vi->IS_inact,&n);
511:           ISGetIndices(vi->IS_inact,&ii);
512:           for (j=0; j<n; j++) {
513:             if (ii[j] < N) cnts[0]++;
514:             else if (ii[j] < 2*N) cnts[1]++;
515:             else if (ii[j] < 3*N) cnts[2]++;
516:           }
517:           ISRestoreIndices(vi->IS_inact,&ii);

519:           PCBJacobiSetTotalBlocks(pc,3,cnts);
520:         }
521:       }
522:     }

524:     KSPSolve(snes->ksp,F_inact,Y_inact);
525:     VecScatterBegin(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);
526:     VecScatterEnd(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);
527:     VecScatterBegin(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);
528:     VecScatterEnd(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);

530:     VecDestroy(&F_inact);
531:     VecDestroy(&Y_act);
532:     VecDestroy(&Y_inact);
533:     VecScatterDestroy(&scat_act);
534:     VecScatterDestroy(&scat_inact);
535:     ISDestroy(&IS_act);
536:     if (!isequal) {
537:       ISDestroy(&vi->IS_inact_prev);
538:       ISDuplicate(vi->IS_inact,&vi->IS_inact_prev);
539:     }
540:     ISDestroy(&vi->IS_inact);
541:     MatDestroy(&jac_inact_inact);
542:     if (snes->jacobian != snes->jacobian_pre) {
543:       MatDestroy(&prejac_inact_inact);
544:     }

546:     KSPGetConvergedReason(snes->ksp,&kspreason);
547:     if (kspreason < 0) {
548:       if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
549:         PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);
550:         snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
551:         break;
552:       }
553:     }

555:     KSPGetIterationNumber(snes->ksp,&lits);
556:     snes->linear_its += lits;
557:     PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);
558:     /*
559:     if (snes->ops->precheck) {
560:       PetscBool changed_y = PETSC_FALSE;
561:       (*snes->ops->precheck)(snes,X,Y,snes->precheck,&changed_y);
562:     }

564:     if (PetscLogPrintInfo) {
565:       SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);
566:     }
567:     */
568:     /* Compute a (scaled) negative update in the line search routine:
569:          Y <- X - lambda*Y
570:        and evaluate G = function(Y) (depends on the line search).
571:     */
572:     VecCopy(Y,snes->vec_sol_update);
573:     ynorm = 1; gnorm = fnorm;
574:     SNESLineSearchApply(snes->linesearch, X, F, &gnorm, Y);
575:     SNESLineSearchGetReason(snes->linesearch, &lssucceed);
576:     SNESLineSearchGetNorms(snes->linesearch, &xnorm, &gnorm, &ynorm);
577:     PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);
578:     if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
579:     if (snes->domainerror) {
580:       snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
581:       DMDestroyVI(snes->dm);
582:       return(0);
583:     }
584:     if (lssucceed) {
585:       if (++snes->numFailures >= snes->maxFailures) {
586:         PetscBool ismin;
587:         snes->reason = SNES_DIVERGED_LINE_SEARCH;
588:         SNESVICheckLocalMin_Private(snes,snes->jacobian,F,X,gnorm,&ismin);
589:         if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN;
590:         break;
591:       }
592:    }
593:    DMDestroyVI(snes->dm);
594:     /* Update function and solution vectors */
595:     fnorm = gnorm;
596:     /* Monitor convergence */
597:     PetscObjectSAWsTakeAccess((PetscObject)snes);
598:     snes->iter = i+1;
599:     snes->norm = fnorm;
600:     snes->xnorm = xnorm;
601:     snes->ynorm = ynorm;
602:     PetscObjectSAWsGrantAccess((PetscObject)snes);
603:     SNESLogConvergenceHistory(snes,snes->norm,lits);
604:     SNESMonitor(snes,snes->iter,snes->norm);
605:     /* Test for convergence, xnorm = || X || */
606:     if (snes->ops->converged != SNESConvergedSkip) { VecNorm(X,NORM_2,&xnorm); }
607:     (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);
608:     if (snes->reason) break;
609:   }
610:   /* make sure that the VI information attached to the DM is removed if the for loop above was broken early due to some exceptional conditional */
611:   DMDestroyVI(snes->dm);
612:   if (i == maxits) {
613:     PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);
614:     if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
615:   }
616:   return(0);
617: }

619: PetscErrorCode SNESVISetRedundancyCheck(SNES snes,PetscErrorCode (*func)(SNES,IS,IS*,void*),void *ctx)
620: {
621:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*)snes->data;

625:   vi->checkredundancy = func;
626:   vi->ctxP            = ctx;
627:   return(0);
628: }

630: #if defined(PETSC_HAVE_MATLAB_ENGINE)
631: #include <engine.h>
632: #include <mex.h>
633: typedef struct {char *funcname; mxArray *ctx;} SNESMatlabContext;

635: PetscErrorCode SNESVIRedundancyCheck_Matlab(SNES snes,IS is_act,IS *is_redact,void *ctx)
636: {
637:   PetscErrorCode    ierr;
638:   SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
639:   int               nlhs  = 1, nrhs = 5;
640:   mxArray           *plhs[1], *prhs[5];
641:   long long int     l1      = 0, l2 = 0, ls = 0;
642:   PetscInt          *indices=NULL;


650:   /* Create IS for reduced active set of size 0, its size and indices will
651:    bet set by the Matlab function */
652:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),0,indices,PETSC_OWN_POINTER,is_redact);
653:   /* call Matlab function in ctx */
654:   PetscArraycpy(&ls,&snes,1);
655:   PetscArraycpy(&l1,&is_act,1);
656:   PetscArraycpy(&l2,is_redact,1);
657:   prhs[0] = mxCreateDoubleScalar((double)ls);
658:   prhs[1] = mxCreateDoubleScalar((double)l1);
659:   prhs[2] = mxCreateDoubleScalar((double)l2);
660:   prhs[3] = mxCreateString(sctx->funcname);
661:   prhs[4] = sctx->ctx;
662:   mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESVIRedundancyCheckInternal");
663:   mxGetScalar(plhs[0]);
664:   mxDestroyArray(prhs[0]);
665:   mxDestroyArray(prhs[1]);
666:   mxDestroyArray(prhs[2]);
667:   mxDestroyArray(prhs[3]);
668:   mxDestroyArray(plhs[0]);
669:   return(0);
670: }

672: PetscErrorCode SNESVISetRedundancyCheckMatlab(SNES snes,const char *func,mxArray *ctx)
673: {
674:   PetscErrorCode    ierr;
675:   SNESMatlabContext *sctx;

678:   /* currently sctx is memory bleed */
679:   PetscNew(&sctx);
680:   PetscStrallocpy(func,&sctx->funcname);
681:   sctx->ctx = mxDuplicateArray(ctx);
682:   SNESVISetRedundancyCheck(snes,SNESVIRedundancyCheck_Matlab,sctx);
683:   return(0);
684: }

686: #endif

688: /* -------------------------------------------------------------------------- */
689: /*
690:    SNESSetUp_VINEWTONRSLS - Sets up the internal data structures for the later use
691:    of the SNESVI nonlinear solver.

693:    Input Parameter:
694: .  snes - the SNES context

696:    Application Interface Routine: SNESSetUp()

698:    Notes:
699:    For basic use of the SNES solvers, the user need not explicitly call
700:    SNESSetUp(), since these actions will automatically occur during
701:    the call to SNESSolve().
702:  */
703: PetscErrorCode SNESSetUp_VINEWTONRSLS(SNES snes)
704: {
705:   PetscErrorCode    ierr;
706:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data;
707:   PetscInt          *indices;
708:   PetscInt          i,n,rstart,rend;
709:   SNESLineSearch    linesearch;

712:   SNESSetUp_VI(snes);

714:   /* Set up previous active index set for the first snes solve
715:    vi->IS_inact_prev = 0,1,2,....N */

717:   VecGetOwnershipRange(snes->vec_sol,&rstart,&rend);
718:   VecGetLocalSize(snes->vec_sol,&n);
719:   PetscMalloc1(n,&indices);
720:   for (i=0; i < n; i++) indices[i] = rstart + i;
721:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),n,indices,PETSC_OWN_POINTER,&vi->IS_inact_prev);

723:   /* set the line search functions */
724:   if (!snes->linesearch) {
725:     SNESGetLineSearch(snes, &linesearch);
726:     SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);
727:   }
728:   return(0);
729: }
730: /* -------------------------------------------------------------------------- */
731: PetscErrorCode SNESReset_VINEWTONRSLS(SNES snes)
732: {
733:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data;
734:   PetscErrorCode    ierr;

737:   SNESReset_VI(snes);
738:   ISDestroy(&vi->IS_inact_prev);
739:   return(0);
740: }

742: /* -------------------------------------------------------------------------- */
743: /*MC
744:       SNESVINEWTONRSLS - Reduced space active set solvers for variational inequalities based on Newton's method

746:    Options Database:
747: +   -snes_type <vinewtonssls,vinewtonrsls> - a semi-smooth solver, a reduced space active set method
748: -   -snes_vi_monitor - prints the number of active constraints at each iteration.

750:    Level: beginner

752:    References:
753: .  1. - T. S. Munson, and S. Benson. Flexible Complementarity Solvers for Large Scale
754:      Applications, Optimization Methods and Software, 21 (2006).

756: .seealso:  SNESVISetVariableBounds(), SNESVISetComputeVariableBounds(), SNESCreate(), SNES, SNESSetType(), SNESVINEWTONSSLS, SNESNEWTONTR, SNESLineSearchSetType(),SNESLineSearchSetPostCheck(), SNESLineSearchSetPreCheck()

758: M*/
759: PETSC_EXTERN PetscErrorCode SNESCreate_VINEWTONRSLS(SNES snes)
760: {
761:   PetscErrorCode    ierr;
762:   SNES_VINEWTONRSLS *vi;
763:   SNESLineSearch    linesearch;

766:   snes->ops->reset          = SNESReset_VINEWTONRSLS;
767:   snes->ops->setup          = SNESSetUp_VINEWTONRSLS;
768:   snes->ops->solve          = SNESSolve_VINEWTONRSLS;
769:   snes->ops->destroy        = SNESDestroy_VI;
770:   snes->ops->setfromoptions = SNESSetFromOptions_VI;
771:   snes->ops->view           = NULL;
772:   snes->ops->converged      = SNESConvergedDefault_VI;

774:   snes->usesksp = PETSC_TRUE;
775:   snes->usesnpc = PETSC_FALSE;

777:   SNESGetLineSearch(snes, &linesearch);
778:   if (!((PetscObject)linesearch)->type_name) {
779:     SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);
780:   }
781:   SNESLineSearchBTSetAlpha(linesearch, 0.0);

783:   snes->alwayscomputesfinalresidual = PETSC_TRUE;

785:   PetscNewLog(snes,&vi);
786:   snes->data          = (void*)vi;
787:   vi->checkredundancy = NULL;

789:   PetscObjectComposeFunction((PetscObject)snes,"SNESVISetVariableBounds_C",SNESVISetVariableBounds_VI);
790:   PetscObjectComposeFunction((PetscObject)snes,"SNESVISetComputeVariableBounds_C",SNESVISetComputeVariableBounds_VI);
791:   return(0);
792: }