Actual source code: virs.c

petsc-3.8.3 2017-12-09
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  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*);

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

 44: /*
 45:      DMCreateGlobalVector_SNESVI - Creates global vector of the size of the reduced space

 47: */
 48: PetscErrorCode  DMCreateGlobalVector_SNESVI(DM dm,Vec *vec)
 49: {
 51:   PetscContainer isnes;
 52:   DM_SNESVI      *dmsnesvi;

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

 62: /*
 63:      DMCreateInterpolation_SNESVI - Modifieds the interpolation obtained from the DM by removing all rows and columns associated with active constraints.

 65: */
 66: PetscErrorCode  DMCreateInterpolation_SNESVI(DM dm1,DM dm2,Mat *mat,Vec *vec)
 67: {
 69:   PetscContainer isnes;
 70:   DM_SNESVI      *dmsnesvi1,*dmsnesvi2;
 71:   Mat            interp;

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

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

 88: extern PetscErrorCode  DMSetVI(DM,IS);

 90: /*
 91:      DMCoarsen_SNESVI - Computes the regular coarsened DM then computes additional information about its inactive set

 93: */
 94: PetscErrorCode  DMCoarsen_SNESVI(DM dm1,MPI_Comm comm,DM *dm2)
 95: {
 97:   PetscContainer isnes;
 98:   DM_SNESVI      *dmsnesvi1;
 99:   Vec            finemarked,coarsemarked;
100:   IS             inactive;
101:   Mat            inject;
102:   const PetscInt *index;
103:   PetscInt       n,k,cnt = 0,rstart,*coarseindex;
104:   PetscScalar    *marked;

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

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

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

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

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

123:   DMCreateGlobalVector(dm1,&finemarked);
124:   DMCreateGlobalVector(*dm2,&coarsemarked);

126:   /*
127:      fill finemarked with locations of inactive points
128:   */
129:   ISGetIndices(dmsnesvi1->inactive,&index);
130:   ISGetLocalSize(dmsnesvi1->inactive,&n);
131:   VecSet(finemarked,0.0);
132:   for (k=0; k<n; k++) {
133:     VecSetValue(finemarked,index[k],1.0,INSERT_VALUES);
134:   }
135:   VecAssemblyBegin(finemarked);
136:   VecAssemblyEnd(finemarked);

138:   DMCreateInjection(*dm2,dm1,&inject);
139:   MatRestrict(inject,finemarked,coarsemarked);
140:   MatDestroy(&inject);

142:   /*
143:      create index set list of coarse inactive points from coarsemarked
144:   */
145:   VecGetLocalSize(coarsemarked,&n);
146:   VecGetOwnershipRange(coarsemarked,&rstart,NULL);
147:   VecGetArray(coarsemarked,&marked);
148:   for (k=0; k<n; k++) {
149:     if (marked[k] != 0.0) cnt++;
150:   }
151:   PetscMalloc1(cnt,&coarseindex);
152:   cnt  = 0;
153:   for (k=0; k<n; k++) {
154:     if (marked[k] != 0.0) coarseindex[cnt++] = k + rstart;
155:   }
156:   VecRestoreArray(coarsemarked,&marked);
157:   ISCreateGeneral(PetscObjectComm((PetscObject)coarsemarked),cnt,coarseindex,PETSC_OWN_POINTER,&inactive);

159:   DMClearGlobalVectors(dm1);

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

163:   DMSetVI(*dm2,inactive);

165:   VecDestroy(&finemarked);
166:   VecDestroy(&coarsemarked);
167:   ISDestroy(&inactive);
168:   return(0);
169: }

171: PetscErrorCode DMDestroy_SNESVI(DM_SNESVI *dmsnesvi)
172: {

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

184:   ISDestroy(&dmsnesvi->inactive);
185:   PetscFree(dmsnesvi);
186:   return(0);
187: }

189: /*
190:      DMSetVI - Marks a DM as associated with a VI problem. This causes the interpolation/restriction operators to
191:                be restricted to only those variables NOT associated with active constraints.

193: */
194: PetscErrorCode  DMSetVI(DM dm,IS inactive)
195: {
197:   PetscContainer isnes;
198:   DM_SNESVI      *dmsnesvi;

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

203:   PetscObjectReference((PetscObject)inactive);

205:   PetscObjectQuery((PetscObject)dm,"VI",(PetscObject*)&isnes);
206:   if (!isnes) {
207:     PetscContainerCreate(PetscObjectComm((PetscObject)dm),&isnes);
208:     PetscContainerSetUserDestroy(isnes,(PetscErrorCode (*)(void*))DMDestroy_SNESVI);
209:     PetscNew(&dmsnesvi);
210:     PetscContainerSetPointer(isnes,(void*)dmsnesvi);
211:     PetscObjectCompose((PetscObject)dm,"VI",(PetscObject)isnes);
212:     PetscContainerDestroy(&isnes);

214:     dmsnesvi->createinterpolation = dm->ops->createinterpolation;
215:     dm->ops->createinterpolation  = DMCreateInterpolation_SNESVI;
216:     dmsnesvi->coarsen             = dm->ops->coarsen;
217:     dm->ops->coarsen              = DMCoarsen_SNESVI;
218:     dmsnesvi->createglobalvector  = dm->ops->createglobalvector;
219:     dm->ops->createglobalvector   = DMCreateGlobalVector_SNESVI;
220:   } else {
221:     PetscContainerGetPointer(isnes,(void**)&dmsnesvi);
222:     ISDestroy(&dmsnesvi->inactive);
223:   }
224:   DMClearGlobalVectors(dm);
225:   ISGetLocalSize(inactive,&dmsnesvi->n);

227:   dmsnesvi->inactive = inactive;
228:   dmsnesvi->dm       = dm;
229:   return(0);
230: }

232: /*
233:      DMDestroyVI - Frees the DM_SNESVI object contained in the DM
234:          - also resets the function pointers in the DM for createinterpolation() etc to use the original DM
235: */
236: PetscErrorCode  DMDestroyVI(DM dm)
237: {

241:   if (!dm) return(0);
242:   PetscObjectCompose((PetscObject)dm,"VI",(PetscObject)NULL);
243:   return(0);
244: }

246: /* --------------------------------------------------------------------------------------------------------*/


249: PetscErrorCode SNESCreateIndexSets_VINEWTONRSLS(SNES snes,Vec X,Vec F,IS *ISact,IS *ISinact)
250: {

254:   SNESVIGetActiveSetIS(snes,X,F,ISact);
255:   ISComplement(*ISact,X->map->rstart,X->map->rend,ISinact);
256:   return(0);
257: }

259: /* Create active and inactive set vectors. The local size of this vector is set and petsc computes the global size */
260: PetscErrorCode SNESCreateSubVectors_VINEWTONRSLS(SNES snes,PetscInt n,Vec *newv)
261: {
263:   Vec            v;

266:   VecCreate(PetscObjectComm((PetscObject)snes),&v);
267:   VecSetSizes(v,n,PETSC_DECIDE);
268:   VecSetType(v,VECSTANDARD);
269:   *newv = v;
270:   return(0);
271: }

273: /* Resets the snes PC and KSP when the active set sizes change */
274: PetscErrorCode SNESVIResetPCandKSP(SNES snes,Mat Amat,Mat Pmat)
275: {
277:   KSP            snesksp;

280:   SNESGetKSP(snes,&snesksp);
281:   KSPReset(snesksp);

283:   /*
284:   KSP                    kspnew;
285:   PC                     pcnew;
286:   const MatSolverPackage stype;


289:   KSPCreate(PetscObjectComm((PetscObject)snes),&kspnew);
290:   kspnew->pc_side = snesksp->pc_side;
291:   kspnew->rtol    = snesksp->rtol;
292:   kspnew->abstol    = snesksp->abstol;
293:   kspnew->max_it  = snesksp->max_it;
294:   KSPSetType(kspnew,((PetscObject)snesksp)->type_name);
295:   KSPGetPC(kspnew,&pcnew);
296:   PCSetType(kspnew->pc,((PetscObject)snesksp->pc)->type_name);
297:   PCSetOperators(kspnew->pc,Amat,Pmat);
298:   PCFactorGetMatSolverPackage(snesksp->pc,&stype);
299:   PCFactorSetMatSolverPackage(kspnew->pc,stype);
300:   KSPDestroy(&snesksp);
301:   snes->ksp = kspnew;
302:   PetscLogObjectParent((PetscObject)snes,(PetscObject)kspnew);
303:    KSPSetFromOptions(kspnew);*/
304:   return(0);
305: }

307: /* Variational Inequality solver using reduce space method. No semismooth algorithm is
308:    implemented in this algorithm. It basically identifies the active constraints and does
309:    a linear solve on the other variables (those not associated with the active constraints). */
310: PetscErrorCode SNESSolve_VINEWTONRSLS(SNES snes)
311: {
312:   SNES_VINEWTONRSLS    *vi = (SNES_VINEWTONRSLS*)snes->data;
313:   PetscErrorCode       ierr;
314:   PetscInt             maxits,i,lits;
315:   SNESLineSearchReason lssucceed;
316:   PetscReal            fnorm,gnorm,xnorm=0,ynorm;
317:   Vec                  Y,X,F;
318:   KSPConvergedReason   kspreason;
319:   KSP                  ksp;
320:   PC                   pc;

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

328:   snes->numFailures            = 0;
329:   snes->numLinearSolveFailures = 0;
330:   snes->reason                 = SNES_CONVERGED_ITERATING;

332:   maxits = snes->max_its;               /* maximum number of iterations */
333:   X      = snes->vec_sol;               /* solution vector */
334:   F      = snes->vec_func;              /* residual vector */
335:   Y      = snes->work[0];               /* work vectors */

337:   SNESLineSearchSetVIFunctions(snes->linesearch, SNESVIProjectOntoBounds, SNESVIComputeInactiveSetFnorm);
338:   SNESLineSearchSetVecs(snes->linesearch, X, NULL, NULL, NULL, NULL);
339:   SNESLineSearchSetUp(snes->linesearch);

341:   PetscObjectSAWsTakeAccess((PetscObject)snes);
342:   snes->iter = 0;
343:   snes->norm = 0.0;
344:   PetscObjectSAWsGrantAccess((PetscObject)snes);

346:   SNESVIProjectOntoBounds(snes,X);
347:   SNESComputeFunction(snes,X,F);
348:   SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);
349:   VecNormBegin(X,NORM_2,&xnorm);        /* xnorm <- ||x||  */
350:   VecNormEnd(X,NORM_2,&xnorm);
351:   SNESCheckFunctionNorm(snes,fnorm);
352:   PetscObjectSAWsTakeAccess((PetscObject)snes);
353:   snes->norm = fnorm;
354:   PetscObjectSAWsGrantAccess((PetscObject)snes);
355:   SNESLogConvergenceHistory(snes,fnorm,0);
356:   SNESMonitor(snes,0,fnorm);

358:   /* test convergence */
359:   (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);
360:   if (snes->reason) return(0);


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

365:     IS         IS_act; /* _act -> active set _inact -> inactive set */
366:     IS         IS_redact; /* redundant active set */
367:     VecScatter scat_act,scat_inact;
368:     PetscInt   nis_act,nis_inact;
369:     Vec        Y_act,Y_inact,F_inact;
370:     Mat        jac_inact_inact,prejac_inact_inact;
371:     PetscBool  isequal;

373:     /* Call general purpose update function */
374:     if (snes->ops->update) {
375:       (*snes->ops->update)(snes, snes->iter);
376:     }
377:     SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);


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

382:     /*original
383:     SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&vi->IS_inact);
384:      */
385:     SNESVIGetActiveSetIS(snes,X,F,&IS_act);

387:     if (vi->checkredundancy) {
388:       (*vi->checkredundancy)(snes,IS_act,&IS_redact,vi->ctxP);
389:       if (IS_redact) {
390:         ISSort(IS_redact);
391:         ISComplement(IS_redact,X->map->rstart,X->map->rend,&vi->IS_inact);
392:         ISDestroy(&IS_redact);
393:       } else {
394:         ISComplement(IS_act,X->map->rstart,X->map->rend,&vi->IS_inact);
395:       }
396:     } else {
397:       ISComplement(IS_act,X->map->rstart,X->map->rend,&vi->IS_inact);
398:     }


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

404:     if (0) {                    /* Dead code (temporary developer hack) */
405:       IS keptrows;
406:       MatFindNonzeroRows(jac_inact_inact,&keptrows);
407:       if (keptrows) {
408:         PetscInt       cnt,*nrows,k;
409:         const PetscInt *krows,*inact;
410:         PetscInt       rstart;

412:         MatGetOwnershipRange(jac_inact_inact,&rstart,NULL);
413:         MatDestroy(&jac_inact_inact);
414:         ISDestroy(&IS_act);

416:         ISGetLocalSize(keptrows,&cnt);
417:         ISGetIndices(keptrows,&krows);
418:         ISGetIndices(vi->IS_inact,&inact);
419:         PetscMalloc1(cnt,&nrows);
420:         for (k=0; k<cnt; k++) nrows[k] = inact[krows[k]-rstart];
421:         ISRestoreIndices(keptrows,&krows);
422:         ISRestoreIndices(vi->IS_inact,&inact);
423:         ISDestroy(&keptrows);
424:         ISDestroy(&vi->IS_inact);

426:         ISCreateGeneral(PetscObjectComm((PetscObject)snes),cnt,nrows,PETSC_OWN_POINTER,&vi->IS_inact);
427:         ISComplement(vi->IS_inact,F->map->rstart,F->map->rend,&IS_act);
428:         MatCreateSubMatrix(snes->jacobian,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);
429:       }
430:     }
431:     DMSetVI(snes->dm,vi->IS_inact);
432:     /* remove later */

434:     /*
435:     VecView(vi->xu,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xu))->comm));
436:     VecView(vi->xl,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xl))->comm));
437:     VecView(X,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)X)));
438:     VecView(F,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)F)));
439:     ISView(vi->IS_inact,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)vi->IS_inact)));
440:      */

442:     /* Get sizes of active and inactive sets */
443:     ISGetLocalSize(IS_act,&nis_act);
444:     ISGetLocalSize(vi->IS_inact,&nis_inact);

446:     /* Create active and inactive set vectors */
447:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&F_inact);
448:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_act,&Y_act);
449:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&Y_inact);

451:     /* Create scatter contexts */
452:     VecScatterCreate(Y,IS_act,Y_act,NULL,&scat_act);
453:     VecScatterCreate(Y,vi->IS_inact,Y_inact,NULL,&scat_inact);

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

459:     VecScatterBegin(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);
460:     VecScatterEnd(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);

462:     VecScatterBegin(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);
463:     VecScatterEnd(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);

465:     /* Active set direction = 0 */
466:     VecSet(Y_act,0);
467:     if (snes->jacobian != snes->jacobian_pre) {
468:       MatCreateSubMatrix(snes->jacobian_pre,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&prejac_inact_inact);
469:     } else prejac_inact_inact = jac_inact_inact;

471:     ISEqual(vi->IS_inact_prev,vi->IS_inact,&isequal);
472:     if (!isequal) {
473:       SNESVIResetPCandKSP(snes,jac_inact_inact,prejac_inact_inact);
474:       PCFieldSplitRestrictIS(pc,vi->IS_inact);
475:     }

477:     /*      ISView(vi->IS_inact,0); */
478:     /*      ISView(IS_act,0);*/
479:     /*      MatView(snes->jacobian_pre,0); */



483:     KSPSetOperators(snes->ksp,jac_inact_inact,prejac_inact_inact);
484:     KSPSetUp(snes->ksp);
485:     {
486:       PC        pc;
487:       PetscBool flg;
488:       KSPGetPC(snes->ksp,&pc);
489:       PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);
490:       if (flg) {
491:         KSP *subksps;
492:         PCFieldSplitGetSubKSP(pc,NULL,&subksps);
493:         KSPGetPC(subksps[0],&pc);
494:         PetscFree(subksps);
495:         PetscObjectTypeCompare((PetscObject)pc,PCBJACOBI,&flg);
496:         if (flg) {
497:           PetscInt       n,N = 101*101,j,cnts[3] = {0,0,0};
498:           const PetscInt *ii;

500:           ISGetSize(vi->IS_inact,&n);
501:           ISGetIndices(vi->IS_inact,&ii);
502:           for (j=0; j<n; j++) {
503:             if (ii[j] < N) cnts[0]++;
504:             else if (ii[j] < 2*N) cnts[1]++;
505:             else if (ii[j] < 3*N) cnts[2]++;
506:           }
507:           ISRestoreIndices(vi->IS_inact,&ii);

509:           PCBJacobiSetTotalBlocks(pc,3,cnts);
510:         }
511:       }
512:     }

514:     KSPSolve(snes->ksp,F_inact,Y_inact);
515:     VecScatterBegin(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);
516:     VecScatterEnd(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);
517:     VecScatterBegin(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);
518:     VecScatterEnd(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);

520:     VecDestroy(&F_inact);
521:     VecDestroy(&Y_act);
522:     VecDestroy(&Y_inact);
523:     VecScatterDestroy(&scat_act);
524:     VecScatterDestroy(&scat_inact);
525:     ISDestroy(&IS_act);
526:     if (!isequal) {
527:       ISDestroy(&vi->IS_inact_prev);
528:       ISDuplicate(vi->IS_inact,&vi->IS_inact_prev);
529:     }
530:     ISDestroy(&vi->IS_inact);
531:     MatDestroy(&jac_inact_inact);
532:     if (snes->jacobian != snes->jacobian_pre) {
533:       MatDestroy(&prejac_inact_inact);
534:     }

536:     KSPGetConvergedReason(snes->ksp,&kspreason);
537:     if (kspreason < 0) {
538:       if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
539:         PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);
540:         snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
541:         break;
542:       }
543:     }

545:     KSPGetIterationNumber(snes->ksp,&lits);
546:     snes->linear_its += lits;
547:     PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);
548:     /*
549:     if (snes->ops->precheck) {
550:       PetscBool changed_y = PETSC_FALSE;
551:       (*snes->ops->precheck)(snes,X,Y,snes->precheck,&changed_y);
552:     }

554:     if (PetscLogPrintInfo) {
555:       SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);
556:     }
557:     */
558:     /* Compute a (scaled) negative update in the line search routine:
559:          Y <- X - lambda*Y
560:        and evaluate G = function(Y) (depends on the line search).
561:     */
562:     VecCopy(Y,snes->vec_sol_update);
563:     ynorm = 1; gnorm = fnorm;
564:     SNESLineSearchApply(snes->linesearch, X, F, &gnorm, Y);
565:     SNESLineSearchGetReason(snes->linesearch, &lssucceed);
566:     SNESLineSearchGetNorms(snes->linesearch, &xnorm, &gnorm, &ynorm);
567:     PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);
568:     if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
569:     if (snes->domainerror) {
570:       snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
571:       DMDestroyVI(snes->dm);
572:       return(0);
573:     }
574:     if (lssucceed) {
575:       if (++snes->numFailures >= snes->maxFailures) {
576:         PetscBool ismin;
577:         snes->reason = SNES_DIVERGED_LINE_SEARCH;
578:         SNESVICheckLocalMin_Private(snes,snes->jacobian,F,X,gnorm,&ismin);
579:         if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN;
580:         break;
581:       }
582:    }
583:    DMDestroyVI(snes->dm);
584:     /* Update function and solution vectors */
585:     fnorm = gnorm;
586:     /* Monitor convergence */
587:     PetscObjectSAWsTakeAccess((PetscObject)snes);
588:     snes->iter = i+1;
589:     snes->norm = fnorm;
590:     PetscObjectSAWsGrantAccess((PetscObject)snes);
591:     SNESLogConvergenceHistory(snes,snes->norm,lits);
592:     SNESMonitor(snes,snes->iter,snes->norm);
593:     /* Test for convergence, xnorm = || X || */
594:     if (snes->ops->converged != SNESConvergedSkip) { VecNorm(X,NORM_2,&xnorm); }
595:     (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);
596:     if (snes->reason) break;
597:   }
598:   /* 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 */
599:   DMDestroyVI(snes->dm);
600:   if (i == maxits) {
601:     PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);
602:     if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
603:   }
604:   return(0);
605: }

607: PetscErrorCode SNESVISetRedundancyCheck(SNES snes,PetscErrorCode (*func)(SNES,IS,IS*,void*),void *ctx)
608: {
609:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*)snes->data;

613:   vi->checkredundancy = func;
614:   vi->ctxP            = ctx;
615:   return(0);
616: }

618: #if defined(PETSC_HAVE_MATLAB_ENGINE)
619: #include <engine.h>
620: #include <mex.h>
621: typedef struct {char *funcname; mxArray *ctx;} SNESMatlabContext;

623: PetscErrorCode SNESVIRedundancyCheck_Matlab(SNES snes,IS is_act,IS *is_redact,void *ctx)
624: {
625:   PetscErrorCode    ierr;
626:   SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
627:   int               nlhs  = 1, nrhs = 5;
628:   mxArray           *plhs[1], *prhs[5];
629:   long long int     l1      = 0, l2 = 0, ls = 0;
630:   PetscInt          *indices=NULL;


638:   /* Create IS for reduced active set of size 0, its size and indices will
639:    bet set by the Matlab function */
640:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),0,indices,PETSC_OWN_POINTER,is_redact);
641:   /* call Matlab function in ctx */
642:   PetscMemcpy(&ls,&snes,sizeof(snes));
643:   PetscMemcpy(&l1,&is_act,sizeof(is_act));
644:   PetscMemcpy(&l2,is_redact,sizeof(is_act));
645:   prhs[0] = mxCreateDoubleScalar((double)ls);
646:   prhs[1] = mxCreateDoubleScalar((double)l1);
647:   prhs[2] = mxCreateDoubleScalar((double)l2);
648:   prhs[3] = mxCreateString(sctx->funcname);
649:   prhs[4] = sctx->ctx;
650:   mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESVIRedundancyCheckInternal");
651:   mxGetScalar(plhs[0]);
652:   mxDestroyArray(prhs[0]);
653:   mxDestroyArray(prhs[1]);
654:   mxDestroyArray(prhs[2]);
655:   mxDestroyArray(prhs[3]);
656:   mxDestroyArray(plhs[0]);
657:   return(0);
658: }

660: PetscErrorCode SNESVISetRedundancyCheckMatlab(SNES snes,const char *func,mxArray *ctx)
661: {
662:   PetscErrorCode    ierr;
663:   SNESMatlabContext *sctx;

666:   /* currently sctx is memory bleed */
667:   PetscNew(&sctx);
668:   PetscStrallocpy(func,&sctx->funcname);
669:   sctx->ctx = mxDuplicateArray(ctx);
670:   SNESVISetRedundancyCheck(snes,SNESVIRedundancyCheck_Matlab,sctx);
671:   return(0);
672: }

674: #endif

676: /* -------------------------------------------------------------------------- */
677: /*
678:    SNESSetUp_VINEWTONRSLS - Sets up the internal data structures for the later use
679:    of the SNESVI nonlinear solver.

681:    Input Parameter:
682: .  snes - the SNES context

684:    Application Interface Routine: SNESSetUp()

686:    Notes:
687:    For basic use of the SNES solvers, the user need not explicitly call
688:    SNESSetUp(), since these actions will automatically occur during
689:    the call to SNESSolve().
690:  */
691: PetscErrorCode SNESSetUp_VINEWTONRSLS(SNES snes)
692: {
693:   PetscErrorCode    ierr;
694:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data;
695:   PetscInt          *indices;
696:   PetscInt          i,n,rstart,rend;
697:   SNESLineSearch    linesearch;

700:   SNESSetUp_VI(snes);

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

705:   VecGetOwnershipRange(snes->vec_sol,&rstart,&rend);
706:   VecGetLocalSize(snes->vec_sol,&n);
707:   PetscMalloc1(n,&indices);
708:   for (i=0; i < n; i++) indices[i] = rstart + i;
709:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),n,indices,PETSC_OWN_POINTER,&vi->IS_inact_prev);

711:   /* set the line search functions */
712:   if (!snes->linesearch) {
713:     SNESGetLineSearch(snes, &linesearch);
714:     SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);
715:   }
716:   return(0);
717: }
718: /* -------------------------------------------------------------------------- */
719: PetscErrorCode SNESReset_VINEWTONRSLS(SNES snes)
720: {
721:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data;
722:   PetscErrorCode    ierr;

725:   SNESReset_VI(snes);
726:   ISDestroy(&vi->IS_inact_prev);
727:   return(0);
728: }

730: /* -------------------------------------------------------------------------- */
731: /*MC
732:       SNESVINEWTONRSLS - Reduced space active set solvers for variational inequalities based on Newton's method

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

738:    Level: beginner

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

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

746: M*/
747: PETSC_EXTERN PetscErrorCode SNESCreate_VINEWTONRSLS(SNES snes)
748: {
749:   PetscErrorCode    ierr;
750:   SNES_VINEWTONRSLS *vi;

753:   snes->ops->reset          = SNESReset_VINEWTONRSLS;
754:   snes->ops->setup          = SNESSetUp_VINEWTONRSLS;
755:   snes->ops->solve          = SNESSolve_VINEWTONRSLS;
756:   snes->ops->destroy        = SNESDestroy_VI;
757:   snes->ops->setfromoptions = SNESSetFromOptions_VI;
758:   snes->ops->view           = NULL;
759:   snes->ops->converged      = SNESConvergedDefault_VI;

761:   snes->usesksp = PETSC_TRUE;
762:   snes->usesnpc = PETSC_FALSE;

764:   snes->alwayscomputesfinalresidual = PETSC_TRUE;

766:   PetscNewLog(snes,&vi);
767:   snes->data          = (void*)vi;
768:   vi->checkredundancy = NULL;

770:   PetscObjectComposeFunction((PetscObject)snes,"SNESVISetVariableBounds_C",SNESVISetVariableBounds_VI);
771:   PetscObjectComposeFunction((PetscObject)snes,"SNESVISetComputeVariableBounds_C",SNESVISetComputeVariableBounds_VI);
772:   return(0);
773: }