Actual source code: virs.c
petsc-3.10.5 2019-03-28
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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*);
     40:   PetscErrorCode (*getinjection)(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:   return(0);
     62: }

     64: static PetscErrorCode DMHasCreateInjection_SNESVI(DM dm, PetscBool *flg)
     65: {
     69:   *flg = PETSC_FALSE;
     70:   return(0);
     71: }

     73: /*
     74:      DMCreateInterpolation_SNESVI - Modifieds the interpolation obtained from the DM by removing all rows and columns associated with active constraints.

     76: */
     77: PetscErrorCode  DMCreateInterpolation_SNESVI(DM dm1,DM dm2,Mat *mat,Vec *vec)
     78: {
     80:   PetscContainer isnes;
     81:   DM_SNESVI      *dmsnesvi1,*dmsnesvi2;
     82:   Mat            interp;

     85:   PetscObjectQuery((PetscObject)dm1,"VI",(PetscObject*)&isnes);
     86:   if (!isnes) SETERRQ(PetscObjectComm((PetscObject)dm1),PETSC_ERR_PLIB,"Composed VI data structure is missing");
     87:   PetscContainerGetPointer(isnes,(void**)&dmsnesvi1);
     88:   PetscObjectQuery((PetscObject)dm2,"VI",(PetscObject*)&isnes);
     89:   if (!isnes) SETERRQ(PetscObjectComm((PetscObject)dm2),PETSC_ERR_PLIB,"Composed VI data structure is missing");
     90:   PetscContainerGetPointer(isnes,(void**)&dmsnesvi2);

     92:   (*dmsnesvi1->createinterpolation)(dm1,dm2,&interp,NULL);
     93:   MatCreateSubMatrix(interp,dmsnesvi2->inactive,dmsnesvi1->inactive,MAT_INITIAL_MATRIX,mat);
     94:   MatDestroy(&interp);
     95:   *vec = 0;
     96:   return(0);
     97: }

     99: static PetscErrorCode DMSetVI(DM,IS);
    100: static PetscErrorCode DMDestroyVI(DM);

    102: /*
    103:      DMCoarsen_SNESVI - Computes the regular coarsened DM then computes additional information about its inactive set

    105: */
    106: PetscErrorCode  DMCoarsen_SNESVI(DM dm1,MPI_Comm comm,DM *dm2)
    107: {
    109:   PetscContainer isnes;
    110:   DM_SNESVI      *dmsnesvi1;
    111:   Vec            finemarked,coarsemarked;
    112:   IS             inactive;
    113:   Mat            inject;
    114:   const PetscInt *index;
    115:   PetscInt       n,k,cnt = 0,rstart,*coarseindex;
    116:   PetscScalar    *marked;

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

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

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

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

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

    135:   DMCreateGlobalVector(dm1,&finemarked);
    136:   DMCreateGlobalVector(*dm2,&coarsemarked);

    138:   /*
    139:      fill finemarked with locations of inactive points
    140:   */
    141:   ISGetIndices(dmsnesvi1->inactive,&index);
    142:   ISGetLocalSize(dmsnesvi1->inactive,&n);
    143:   VecSet(finemarked,0.0);
    144:   for (k=0; k<n; k++) {
    145:     VecSetValue(finemarked,index[k],1.0,INSERT_VALUES);
    146:   }
    147:   VecAssemblyBegin(finemarked);
    148:   VecAssemblyEnd(finemarked);

    150:   DMCreateInjection(*dm2,dm1,&inject);
    151:   MatRestrict(inject,finemarked,coarsemarked);
    152:   MatDestroy(&inject);

    154:   /*
    155:      create index set list of coarse inactive points from coarsemarked
    156:   */
    157:   VecGetLocalSize(coarsemarked,&n);
    158:   VecGetOwnershipRange(coarsemarked,&rstart,NULL);
    159:   VecGetArray(coarsemarked,&marked);
    160:   for (k=0; k<n; k++) {
    161:     if (marked[k] != 0.0) cnt++;
    162:   }
    163:   PetscMalloc1(cnt,&coarseindex);
    164:   cnt  = 0;
    165:   for (k=0; k<n; k++) {
    166:     if (marked[k] != 0.0) coarseindex[cnt++] = k + rstart;
    167:   }
    168:   VecRestoreArray(coarsemarked,&marked);
    169:   ISCreateGeneral(PetscObjectComm((PetscObject)coarsemarked),cnt,coarseindex,PETSC_OWN_POINTER,&inactive);

    171:   DMClearGlobalVectors(dm1);

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

    175:   DMSetVI(*dm2,inactive);

    177:   VecDestroy(&finemarked);
    178:   VecDestroy(&coarsemarked);
    179:   ISDestroy(&inactive);
    180:   return(0);
    181: }

    183: PetscErrorCode DMDestroy_SNESVI(DM_SNESVI *dmsnesvi)
    184: {

    188:   /* reset the base methods in the DM object that were changed when the DM_SNESVI was reset */
    189:   dmsnesvi->dm->ops->createinterpolation = dmsnesvi->createinterpolation;
    190:   dmsnesvi->dm->ops->coarsen             = dmsnesvi->coarsen;
    191:   dmsnesvi->dm->ops->createglobalvector  = dmsnesvi->createglobalvector;
    192:   dmsnesvi->dm->ops->getinjection        = dmsnesvi->getinjection;
    193:   dmsnesvi->dm->ops->hascreateinjection  = dmsnesvi->hascreateinjection;
    194:   /* need to clear out this vectors because some of them may not have a reference to the DM
    195:     but they are counted as having references to the DM in DMDestroy() */
    196:   DMClearGlobalVectors(dmsnesvi->dm);

    198:   ISDestroy(&dmsnesvi->inactive);
    199:   PetscFree(dmsnesvi);
    200:   return(0);
    201: }

    203: /*
    204:      DMSetVI - Marks a DM as associated with a VI problem. This causes the interpolation/restriction operators to
    205:                be restricted to only those variables NOT associated with active constraints.

    207: */
    208: static PetscErrorCode DMSetVI(DM dm,IS inactive)
    209: {
    211:   PetscContainer isnes;
    212:   DM_SNESVI      *dmsnesvi;

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

    217:   PetscObjectReference((PetscObject)inactive);

    219:   PetscObjectQuery((PetscObject)dm,"VI",(PetscObject*)&isnes);
    220:   if (!isnes) {
    221:     PetscContainerCreate(PetscObjectComm((PetscObject)dm),&isnes);
    222:     PetscContainerSetUserDestroy(isnes,(PetscErrorCode (*)(void*))DMDestroy_SNESVI);
    223:     PetscNew(&dmsnesvi);
    224:     PetscContainerSetPointer(isnes,(void*)dmsnesvi);
    225:     PetscObjectCompose((PetscObject)dm,"VI",(PetscObject)isnes);
    226:     PetscContainerDestroy(&isnes);

    228:     dmsnesvi->createinterpolation = dm->ops->createinterpolation;
    229:     dm->ops->createinterpolation  = DMCreateInterpolation_SNESVI;
    230:     dmsnesvi->coarsen             = dm->ops->coarsen;
    231:     dm->ops->coarsen              = DMCoarsen_SNESVI;
    232:     dmsnesvi->createglobalvector  = dm->ops->createglobalvector;
    233:     dm->ops->createglobalvector   = DMCreateGlobalVector_SNESVI;
    234:     dmsnesvi->getinjection        = dm->ops->getinjection;
    235:     dm->ops->getinjection         = NULL;
    236:     dmsnesvi->hascreateinjection  = dm->ops->hascreateinjection;
    237:     dm->ops->hascreateinjection   = DMHasCreateInjection_SNESVI;
    238:   } else {
    239:     PetscContainerGetPointer(isnes,(void**)&dmsnesvi);
    240:     ISDestroy(&dmsnesvi->inactive);
    241:   }
    242:   DMClearGlobalVectors(dm);
    243:   ISGetLocalSize(inactive,&dmsnesvi->n);

    245:   dmsnesvi->inactive = inactive;
    246:   dmsnesvi->dm       = dm;
    247:   return(0);
    248: }

    250: /*
    251:      DMDestroyVI - Frees the DM_SNESVI object contained in the DM
    252:          - also resets the function pointers in the DM for createinterpolation() etc to use the original DM
    253: */
    254: static PetscErrorCode DMDestroyVI(DM dm)
    255: {

    259:   if (!dm) return(0);
    260:   PetscObjectCompose((PetscObject)dm,"VI",(PetscObject)NULL);
    261:   return(0);
    262: }

    264: /* --------------------------------------------------------------------------------------------------------*/

    267: PetscErrorCode SNESCreateIndexSets_VINEWTONRSLS(SNES snes,Vec X,Vec F,IS *ISact,IS *ISinact)
    268: {

    272:   SNESVIGetActiveSetIS(snes,X,F,ISact);
    273:   ISComplement(*ISact,X->map->rstart,X->map->rend,ISinact);
    274:   return(0);
    275: }

    277: /* Create active and inactive set vectors. The local size of this vector is set and petsc computes the global size */
    278: PetscErrorCode SNESCreateSubVectors_VINEWTONRSLS(SNES snes,PetscInt n,Vec *newv)
    279: {
    281:   Vec            v;

    284:   VecCreate(PetscObjectComm((PetscObject)snes),&v);
    285:   VecSetSizes(v,n,PETSC_DECIDE);
    286:   VecSetType(v,VECSTANDARD);
    287:   *newv = v;
    288:   return(0);
    289: }

    291: /* Resets the snes PC and KSP when the active set sizes change */
    292: PetscErrorCode SNESVIResetPCandKSP(SNES snes,Mat Amat,Mat Pmat)
    293: {
    295:   KSP            snesksp;

    298:   SNESGetKSP(snes,&snesksp);
    299:   KSPReset(snesksp);
    300:   KSPResetFromOptions(snesksp);

    302:   /*
    303:   KSP                    kspnew;
    304:   PC                     pcnew;
    305:   MatSolverType          stype;

    308:   KSPCreate(PetscObjectComm((PetscObject)snes),&kspnew);
    309:   kspnew->pc_side = snesksp->pc_side;
    310:   kspnew->rtol    = snesksp->rtol;
    311:   kspnew->abstol    = snesksp->abstol;
    312:   kspnew->max_it  = snesksp->max_it;
    313:   KSPSetType(kspnew,((PetscObject)snesksp)->type_name);
    314:   KSPGetPC(kspnew,&pcnew);
    315:   PCSetType(kspnew->pc,((PetscObject)snesksp->pc)->type_name);
    316:   PCSetOperators(kspnew->pc,Amat,Pmat);
    317:   PCFactorGetMatSolverType(snesksp->pc,&stype);
    318:   PCFactorSetMatSolverType(kspnew->pc,stype);
    319:   KSPDestroy(&snesksp);
    320:   snes->ksp = kspnew;
    321:   PetscLogObjectParent((PetscObject)snes,(PetscObject)kspnew);
    322:    KSPSetFromOptions(kspnew);*/
    323:   return(0);
    324: }

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

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

    347:   snes->numFailures            = 0;
    348:   snes->numLinearSolveFailures = 0;
    349:   snes->reason                 = SNES_CONVERGED_ITERATING;

    351:   maxits = snes->max_its;               /* maximum number of iterations */
    352:   X      = snes->vec_sol;               /* solution vector */
    353:   F      = snes->vec_func;              /* residual vector */
    354:   Y      = snes->work[0];               /* work vectors */

    356:   SNESLineSearchSetVIFunctions(snes->linesearch, SNESVIProjectOntoBounds, SNESVIComputeInactiveSetFnorm);
    357:   SNESLineSearchSetVecs(snes->linesearch, X, NULL, NULL, NULL, NULL);
    358:   SNESLineSearchSetUp(snes->linesearch);

    360:   PetscObjectSAWsTakeAccess((PetscObject)snes);
    361:   snes->iter = 0;
    362:   snes->norm = 0.0;
    363:   PetscObjectSAWsGrantAccess((PetscObject)snes);

    365:   SNESVIProjectOntoBounds(snes,X);
    366:   SNESComputeFunction(snes,X,F);
    367:   SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);
    368:   VecNorm(X,NORM_2,&xnorm);        /* xnorm <- ||x||  */
    369:   SNESCheckFunctionNorm(snes,fnorm);
    370:   PetscObjectSAWsTakeAccess((PetscObject)snes);
    371:   snes->norm = fnorm;
    372:   PetscObjectSAWsGrantAccess((PetscObject)snes);
    373:   SNESLogConvergenceHistory(snes,fnorm,0);
    374:   SNESMonitor(snes,0,fnorm);

    376:   /* test convergence */
    377:   (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);
    378:   if (snes->reason) return(0);

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

    383:     IS         IS_act; /* _act -> active set _inact -> inactive set */
    384:     IS         IS_redact; /* redundant active set */
    385:     VecScatter scat_act,scat_inact;
    386:     PetscInt   nis_act,nis_inact;
    387:     Vec        Y_act,Y_inact,F_inact;
    388:     Mat        jac_inact_inact,prejac_inact_inact;
    389:     PetscBool  isequal;

    391:     /* Call general purpose update function */
    392:     if (snes->ops->update) {
    393:       (*snes->ops->update)(snes, snes->iter);
    394:     }
    395:     SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);

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

    400:     /*original
    401:     SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&vi->IS_inact);
    402:      */
    403:     SNESVIGetActiveSetIS(snes,X,F,&IS_act);

    405:     if (vi->checkredundancy) {
    406:       (*vi->checkredundancy)(snes,IS_act,&IS_redact,vi->ctxP);
    407:       if (IS_redact) {
    408:         ISSort(IS_redact);
    409:         ISComplement(IS_redact,X->map->rstart,X->map->rend,&vi->IS_inact);
    410:         ISDestroy(&IS_redact);
    411:       } else {
    412:         ISComplement(IS_act,X->map->rstart,X->map->rend,&vi->IS_inact);
    413:       }
    414:     } else {
    415:       ISComplement(IS_act,X->map->rstart,X->map->rend,&vi->IS_inact);
    416:     }

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

    422:     if (0) {                    /* Dead code (temporary developer hack) */
    423:       IS keptrows;
    424:       MatFindNonzeroRows(jac_inact_inact,&keptrows);
    425:       if (keptrows) {
    426:         PetscInt       cnt,*nrows,k;
    427:         const PetscInt *krows,*inact;
    428:         PetscInt       rstart;

    430:         MatGetOwnershipRange(jac_inact_inact,&rstart,NULL);
    431:         MatDestroy(&jac_inact_inact);
    432:         ISDestroy(&IS_act);

    434:         ISGetLocalSize(keptrows,&cnt);
    435:         ISGetIndices(keptrows,&krows);
    436:         ISGetIndices(vi->IS_inact,&inact);
    437:         PetscMalloc1(cnt,&nrows);
    438:         for (k=0; k<cnt; k++) nrows[k] = inact[krows[k]-rstart];
    439:         ISRestoreIndices(keptrows,&krows);
    440:         ISRestoreIndices(vi->IS_inact,&inact);
    441:         ISDestroy(&keptrows);
    442:         ISDestroy(&vi->IS_inact);

    444:         ISCreateGeneral(PetscObjectComm((PetscObject)snes),cnt,nrows,PETSC_OWN_POINTER,&vi->IS_inact);
    445:         ISComplement(vi->IS_inact,F->map->rstart,F->map->rend,&IS_act);
    446:         MatCreateSubMatrix(snes->jacobian,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);
    447:       }
    448:     }
    449:     DMSetVI(snes->dm,vi->IS_inact);
    450:     /* remove later */

    452:     /*
    453:     VecView(vi->xu,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xu))->comm));
    454:     VecView(vi->xl,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xl))->comm));
    455:     VecView(X,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)X)));
    456:     VecView(F,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)F)));
    457:     ISView(vi->IS_inact,PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)vi->IS_inact)));
    458:      */

    460:     /* Get sizes of active and inactive sets */
    461:     ISGetLocalSize(IS_act,&nis_act);
    462:     ISGetLocalSize(vi->IS_inact,&nis_inact);

    464:     /* Create active and inactive set vectors */
    465:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&F_inact);
    466:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_act,&Y_act);
    467:     SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&Y_inact);

    469:     /* Create scatter contexts */
    470:     VecScatterCreate(Y,IS_act,Y_act,NULL,&scat_act);
    471:     VecScatterCreate(Y,vi->IS_inact,Y_inact,NULL,&scat_inact);

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

    477:     VecScatterBegin(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);
    478:     VecScatterEnd(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);

    480:     VecScatterBegin(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);
    481:     VecScatterEnd(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);

    483:     /* Active set direction = 0 */
    484:     VecSet(Y_act,0);
    485:     if (snes->jacobian != snes->jacobian_pre) {
    486:       MatCreateSubMatrix(snes->jacobian_pre,vi->IS_inact,vi->IS_inact,MAT_INITIAL_MATRIX,&prejac_inact_inact);
    487:     } else prejac_inact_inact = jac_inact_inact;

    489:     ISEqual(vi->IS_inact_prev,vi->IS_inact,&isequal);
    490:     if (!isequal) {
    491:       SNESVIResetPCandKSP(snes,jac_inact_inact,prejac_inact_inact);
    492:       PCFieldSplitRestrictIS(pc,vi->IS_inact);
    493:     }

    495:     /*      ISView(vi->IS_inact,0); */
    496:     /*      ISView(IS_act,0);*/
    497:     /*      MatView(snes->jacobian_pre,0); */

    501:     KSPSetOperators(snes->ksp,jac_inact_inact,prejac_inact_inact);
    502:     KSPSetUp(snes->ksp);
    503:     {
    504:       PC        pc;
    505:       PetscBool flg;
    506:       KSPGetPC(snes->ksp,&pc);
    507:       PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);
    508:       if (flg) {
    509:         KSP *subksps;
    510:         PCFieldSplitGetSubKSP(pc,NULL,&subksps);
    511:         KSPGetPC(subksps[0],&pc);
    512:         PetscFree(subksps);
    513:         PetscObjectTypeCompare((PetscObject)pc,PCBJACOBI,&flg);
    514:         if (flg) {
    515:           PetscInt       n,N = 101*101,j,cnts[3] = {0,0,0};
    516:           const PetscInt *ii;

    518:           ISGetSize(vi->IS_inact,&n);
    519:           ISGetIndices(vi->IS_inact,&ii);
    520:           for (j=0; j<n; j++) {
    521:             if (ii[j] < N) cnts[0]++;
    522:             else if (ii[j] < 2*N) cnts[1]++;
    523:             else if (ii[j] < 3*N) cnts[2]++;
    524:           }
    525:           ISRestoreIndices(vi->IS_inact,&ii);

    527:           PCBJacobiSetTotalBlocks(pc,3,cnts);
    528:         }
    529:       }
    530:     }

    532:     KSPSolve(snes->ksp,F_inact,Y_inact);
    533:     VecScatterBegin(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);
    534:     VecScatterEnd(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);
    535:     VecScatterBegin(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);
    536:     VecScatterEnd(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);

    538:     VecDestroy(&F_inact);
    539:     VecDestroy(&Y_act);
    540:     VecDestroy(&Y_inact);
    541:     VecScatterDestroy(&scat_act);
    542:     VecScatterDestroy(&scat_inact);
    543:     ISDestroy(&IS_act);
    544:     if (!isequal) {
    545:       ISDestroy(&vi->IS_inact_prev);
    546:       ISDuplicate(vi->IS_inact,&vi->IS_inact_prev);
    547:     }
    548:     ISDestroy(&vi->IS_inact);
    549:     MatDestroy(&jac_inact_inact);
    550:     if (snes->jacobian != snes->jacobian_pre) {
    551:       MatDestroy(&prejac_inact_inact);
    552:     }

    554:     KSPGetConvergedReason(snes->ksp,&kspreason);
    555:     if (kspreason < 0) {
    556:       if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
    557:         PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);
    558:         snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
    559:         break;
    560:       }
    561:     }

    563:     KSPGetIterationNumber(snes->ksp,&lits);
    564:     snes->linear_its += lits;
    565:     PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);
    566:     /*
    567:     if (snes->ops->precheck) {
    568:       PetscBool changed_y = PETSC_FALSE;
    569:       (*snes->ops->precheck)(snes,X,Y,snes->precheck,&changed_y);
    570:     }

    572:     if (PetscLogPrintInfo) {
    573:       SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);
    574:     }
    575:     */
    576:     /* Compute a (scaled) negative update in the line search routine:
    577:          Y <- X - lambda*Y
    578:        and evaluate G = function(Y) (depends on the line search).
    579:     */
    580:     VecCopy(Y,snes->vec_sol_update);
    581:     ynorm = 1; gnorm = fnorm;
    582:     SNESLineSearchApply(snes->linesearch, X, F, &gnorm, Y);
    583:     SNESLineSearchGetReason(snes->linesearch, &lssucceed);
    584:     SNESLineSearchGetNorms(snes->linesearch, &xnorm, &gnorm, &ynorm);
    585:     PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);
    586:     if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
    587:     if (snes->domainerror) {
    588:       snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
    589:       DMDestroyVI(snes->dm);
    590:       return(0);
    591:     }
    592:     if (lssucceed) {
    593:       if (++snes->numFailures >= snes->maxFailures) {
    594:         PetscBool ismin;
    595:         snes->reason = SNES_DIVERGED_LINE_SEARCH;
    596:         SNESVICheckLocalMin_Private(snes,snes->jacobian,F,X,gnorm,&ismin);
    597:         if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN;
    598:         break;
    599:       }
    600:    }
    601:    DMDestroyVI(snes->dm);
    602:     /* Update function and solution vectors */
    603:     fnorm = gnorm;
    604:     /* Monitor convergence */
    605:     PetscObjectSAWsTakeAccess((PetscObject)snes);
    606:     snes->iter = i+1;
    607:     snes->norm = fnorm;
    608:     PetscObjectSAWsGrantAccess((PetscObject)snes);
    609:     SNESLogConvergenceHistory(snes,snes->norm,lits);
    610:     SNESMonitor(snes,snes->iter,snes->norm);
    611:     /* Test for convergence, xnorm = || X || */
    612:     if (snes->ops->converged != SNESConvergedSkip) { VecNorm(X,NORM_2,&xnorm); }
    613:     (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);
    614:     if (snes->reason) break;
    615:   }
    616:   /* 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 */
    617:   DMDestroyVI(snes->dm);
    618:   if (i == maxits) {
    619:     PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);
    620:     if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
    621:   }
    622:   return(0);
    623: }

    625: PetscErrorCode SNESVISetRedundancyCheck(SNES snes,PetscErrorCode (*func)(SNES,IS,IS*,void*),void *ctx)
    626: {
    627:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*)snes->data;

    631:   vi->checkredundancy = func;
    632:   vi->ctxP            = ctx;
    633:   return(0);
    634: }

    636: #if defined(PETSC_HAVE_MATLAB_ENGINE)
    637: #include <engine.h>
    638: #include <mex.h>
    639: typedef struct {char *funcname; mxArray *ctx;} SNESMatlabContext;

    641: PetscErrorCode SNESVIRedundancyCheck_Matlab(SNES snes,IS is_act,IS *is_redact,void *ctx)
    642: {
    643:   PetscErrorCode    ierr;
    644:   SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
    645:   int               nlhs  = 1, nrhs = 5;
    646:   mxArray           *plhs[1], *prhs[5];
    647:   long long int     l1      = 0, l2 = 0, ls = 0;
    648:   PetscInt          *indices=NULL;

    656:   /* Create IS for reduced active set of size 0, its size and indices will
    657:    bet set by the Matlab function */
    658:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),0,indices,PETSC_OWN_POINTER,is_redact);
    659:   /* call Matlab function in ctx */
    660:   PetscMemcpy(&ls,&snes,sizeof(snes));
    661:   PetscMemcpy(&l1,&is_act,sizeof(is_act));
    662:   PetscMemcpy(&l2,is_redact,sizeof(is_act));
    663:   prhs[0] = mxCreateDoubleScalar((double)ls);
    664:   prhs[1] = mxCreateDoubleScalar((double)l1);
    665:   prhs[2] = mxCreateDoubleScalar((double)l2);
    666:   prhs[3] = mxCreateString(sctx->funcname);
    667:   prhs[4] = sctx->ctx;
    668:   mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESVIRedundancyCheckInternal");
    669:   mxGetScalar(plhs[0]);
    670:   mxDestroyArray(prhs[0]);
    671:   mxDestroyArray(prhs[1]);
    672:   mxDestroyArray(prhs[2]);
    673:   mxDestroyArray(prhs[3]);
    674:   mxDestroyArray(plhs[0]);
    675:   return(0);
    676: }

    678: PetscErrorCode SNESVISetRedundancyCheckMatlab(SNES snes,const char *func,mxArray *ctx)
    679: {
    680:   PetscErrorCode    ierr;
    681:   SNESMatlabContext *sctx;

    684:   /* currently sctx is memory bleed */
    685:   PetscNew(&sctx);
    686:   PetscStrallocpy(func,&sctx->funcname);
    687:   sctx->ctx = mxDuplicateArray(ctx);
    688:   SNESVISetRedundancyCheck(snes,SNESVIRedundancyCheck_Matlab,sctx);
    689:   return(0);
    690: }

    692: #endif

    694: /* -------------------------------------------------------------------------- */
    695: /*
    696:    SNESSetUp_VINEWTONRSLS - Sets up the internal data structures for the later use
    697:    of the SNESVI nonlinear solver.

    699:    Input Parameter:
    700: .  snes - the SNES context

    702:    Application Interface Routine: SNESSetUp()

    704:    Notes:
    705:    For basic use of the SNES solvers, the user need not explicitly call
    706:    SNESSetUp(), since these actions will automatically occur during
    707:    the call to SNESSolve().
    708:  */
    709: PetscErrorCode SNESSetUp_VINEWTONRSLS(SNES snes)
    710: {
    711:   PetscErrorCode    ierr;
    712:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data;
    713:   PetscInt          *indices;
    714:   PetscInt          i,n,rstart,rend;
    715:   SNESLineSearch    linesearch;

    718:   SNESSetUp_VI(snes);

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

    723:   VecGetOwnershipRange(snes->vec_sol,&rstart,&rend);
    724:   VecGetLocalSize(snes->vec_sol,&n);
    725:   PetscMalloc1(n,&indices);
    726:   for (i=0; i < n; i++) indices[i] = rstart + i;
    727:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),n,indices,PETSC_OWN_POINTER,&vi->IS_inact_prev);

    729:   /* set the line search functions */
    730:   if (!snes->linesearch) {
    731:     SNESGetLineSearch(snes, &linesearch);
    732:     SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);
    733:   }
    734:   return(0);
    735: }
    736: /* -------------------------------------------------------------------------- */
    737: PetscErrorCode SNESReset_VINEWTONRSLS(SNES snes)
    738: {
    739:   SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data;
    740:   PetscErrorCode    ierr;

    743:   SNESReset_VI(snes);
    744:   ISDestroy(&vi->IS_inact_prev);
    745:   return(0);
    746: }

    748: /* -------------------------------------------------------------------------- */
    749: /*MC
    750:       SNESVINEWTONRSLS - Reduced space active set solvers for variational inequalities based on Newton's method

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

    756:    Level: beginner

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

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

    764: M*/
    765: PETSC_EXTERN PetscErrorCode SNESCreate_VINEWTONRSLS(SNES snes)
    766: {
    767:   PetscErrorCode    ierr;
    768:   SNES_VINEWTONRSLS *vi;

    771:   snes->ops->reset          = SNESReset_VINEWTONRSLS;
    772:   snes->ops->setup          = SNESSetUp_VINEWTONRSLS;
    773:   snes->ops->solve          = SNESSolve_VINEWTONRSLS;
    774:   snes->ops->destroy        = SNESDestroy_VI;
    775:   snes->ops->setfromoptions = SNESSetFromOptions_VI;
    776:   snes->ops->view           = NULL;
    777:   snes->ops->converged      = SNESConvergedDefault_VI;

    779:   snes->usesksp = PETSC_TRUE;
    780:   snes->usesnpc = PETSC_FALSE;

    782:   snes->alwayscomputesfinalresidual = PETSC_TRUE;

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

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