Date: 2022-03-04T17:39:23+00:00

Actual source code: vi.c

      1: #include <petsc/private/snesimpl.h>
      2: #include <petscdm.h>

      4: /*@C
      5:    SNESVISetComputeVariableBounds - Sets a function that is called to compute the variable bounds

      7:    Input parameter:
      8: +  snes - the SNES context
      9: -  compute - computes the bounds

     11:    Level: advanced

     13: .seealso:   SNESVISetVariableBounds()

     15: @*/
     16: PetscErrorCode SNESVISetComputeVariableBounds(SNES snes, PetscErrorCode (*compute)(SNES,Vec,Vec))
     17: {
     18:   PetscErrorCode ierr,(*f)(SNES,PetscErrorCode (*)(SNES,Vec,Vec));

     22:   PetscObjectQueryFunction((PetscObject)snes,"SNESVISetComputeVariableBounds_C",&f);
     23:   if (!f) {
     24:     SNESVISetComputeVariableBounds_VI(snes,compute);
     25:   } else {
     26:     PetscUseMethod(snes,"SNESVISetComputeVariableBounds_C",(SNES,PetscErrorCode (*)(SNES,Vec,Vec)),(snes,compute));
     27:   }
     28:   return(0);
     29: }

     31: PetscErrorCode SNESVISetComputeVariableBounds_VI(SNES snes,SNESVIComputeVariableBoundsFunction compute)
     32: {
     34:   snes->ops->computevariablebounds = compute;
     35:   return(0);
     36: }

     38: /* --------------------------------------------------------------------------------------------------------*/

     40: PetscErrorCode  SNESVIMonitorResidual(SNES snes,PetscInt its,PetscReal fgnorm,void *dummy)
     41: {
     43:   Vec            X, F, Finactive;
     44:   IS             isactive;
     45:   PetscViewer    viewer = (PetscViewer) dummy;

     48:   SNESGetFunction(snes,&F,NULL,NULL);
     49:   SNESGetSolution(snes,&X);
     50:   SNESVIGetActiveSetIS(snes,X,F,&isactive);
     51:   VecDuplicate(F,&Finactive);
     52:   VecCopy(F,Finactive);
     53:   VecISSet(Finactive,isactive,0.0);
     54:   ISDestroy(&isactive);
     55:   VecView(Finactive,viewer);
     56:   VecDestroy(&Finactive);
     57:   return(0);
     58: }

     60: PetscErrorCode  SNESMonitorVI(SNES snes,PetscInt its,PetscReal fgnorm,void *dummy)
     61: {
     62:   PetscErrorCode    ierr;
     63:   PetscViewer       viewer = (PetscViewer) dummy;
     64:   const PetscScalar *x,*xl,*xu,*f;
     65:   PetscInt          i,n,act[2] = {0,0},fact[2],N;
     66:   /* Number of components that actually hit the bounds (c.f. active variables) */
     67:   PetscInt          act_bound[2] = {0,0},fact_bound[2];
     68:   PetscReal         rnorm,fnorm,zerotolerance = snes->vizerotolerance;
     69:   double            tmp;

     73:   VecGetLocalSize(snes->vec_sol,&n);
     74:   VecGetSize(snes->vec_sol,&N);
     75:   VecGetArrayRead(snes->xl,&xl);
     76:   VecGetArrayRead(snes->xu,&xu);
     77:   VecGetArrayRead(snes->vec_sol,&x);
     78:   VecGetArrayRead(snes->vec_func,&f);

     80:   rnorm = 0.0;
     81:   for (i=0; i<n; i++) {
     82:     if (((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0))) rnorm += PetscRealPart(PetscConj(f[i])*f[i]);
     83:     else if (PetscRealPart(x[i]) <= PetscRealPart(xl[i]) + zerotolerance && PetscRealPart(f[i]) > 0.0) act[0]++;
     84:     else if (PetscRealPart(x[i]) >= PetscRealPart(xu[i]) - zerotolerance && PetscRealPart(f[i]) < 0.0) act[1]++;
     85:     else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"Can never get here");
     86:   }

     88:   for (i=0; i<n; i++) {
     89:     if (PetscRealPart(x[i]) <= PetscRealPart(xl[i]) + zerotolerance) act_bound[0]++;
     90:     else if (PetscRealPart(x[i]) >= PetscRealPart(xu[i]) - zerotolerance) act_bound[1]++;
     91:   }
     92:   VecRestoreArrayRead(snes->vec_func,&f);
     93:   VecRestoreArrayRead(snes->xl,&xl);
     94:   VecRestoreArrayRead(snes->xu,&xu);
     95:   VecRestoreArrayRead(snes->vec_sol,&x);
     96:   MPIU_Allreduce(&rnorm,&fnorm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)snes));
     97:   MPIU_Allreduce(act,fact,2,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)snes));
     98:   MPIU_Allreduce(act_bound,fact_bound,2,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)snes));
     99:   fnorm = PetscSqrtReal(fnorm);

    101:   PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
    102:   if (snes->ntruebounds) tmp = ((double)(fact[0]+fact[1]))/((double)snes->ntruebounds);
    103:   else tmp = 0.0;
    104:   PetscViewerASCIIPrintf(viewer,"%3D SNES VI Function norm %g Active lower constraints %D/%D upper constraints %D/%D Percent of total %g Percent of bounded %g\n",its,(double)fnorm,fact[0],fact_bound[0],fact[1],fact_bound[1],((double)(fact[0]+fact[1]))/((double)N),tmp);

    106:   PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
    107:   return(0);
    108: }

    110: /*
    111:      Checks if J^T F = 0 which implies we've found a local minimum of the norm of the function,
    112:     || F(u) ||_2 but not a zero, F(u) = 0. In the case when one cannot compute J^T F we use the fact that
    113:     0 = (J^T F)^T W = F^T J W iff W not in the null space of J. Thanks for Jorge More
    114:     for this trick. One assumes that the probability that W is in the null space of J is very, very small.
    115: */
    116: PetscErrorCode SNESVICheckLocalMin_Private(SNES snes,Mat A,Vec F,Vec W,PetscReal fnorm,PetscBool *ismin)
    117: {
    118:   PetscReal      a1;
    120:   PetscBool      hastranspose;

    123:   *ismin = PETSC_FALSE;
    124:   MatHasOperation(A,MATOP_MULT_TRANSPOSE,&hastranspose);
    125:   if (hastranspose) {
    126:     /* Compute || J^T F|| */
    127:     MatMultTranspose(A,F,W);
    128:     VecNorm(W,NORM_2,&a1);
    129:     PetscInfo1(snes,"|| J^T F|| %g near zero implies found a local minimum\n",(double)(a1/fnorm));
    130:     if (a1/fnorm < 1.e-4) *ismin = PETSC_TRUE;
    131:   } else {
    132:     Vec         work;
    133:     PetscScalar result;
    134:     PetscReal   wnorm;

    136:     VecSetRandom(W,NULL);
    137:     VecNorm(W,NORM_2,&wnorm);
    138:     VecDuplicate(W,&work);
    139:     MatMult(A,W,work);
    140:     VecDot(F,work,&result);
    141:     VecDestroy(&work);
    142:     a1   = PetscAbsScalar(result)/(fnorm*wnorm);
    143:     PetscInfo1(snes,"(F^T J random)/(|| F ||*||random|| %g near zero implies found a local minimum\n",(double)a1);
    144:     if (a1 < 1.e-4) *ismin = PETSC_TRUE;
    145:   }
    146:   return(0);
    147: }

    149: /*
    150:      Checks if J^T(F - J*X) = 0
    151: */
    152: PetscErrorCode SNESVICheckResidual_Private(SNES snes,Mat A,Vec F,Vec X,Vec W1,Vec W2)
    153: {
    154:   PetscReal      a1,a2;
    156:   PetscBool      hastranspose;

    159:   MatHasOperation(A,MATOP_MULT_TRANSPOSE,&hastranspose);
    160:   if (hastranspose) {
    161:     MatMult(A,X,W1);
    162:     VecAXPY(W1,-1.0,F);

    164:     /* Compute || J^T W|| */
    165:     MatMultTranspose(A,W1,W2);
    166:     VecNorm(W1,NORM_2,&a1);
    167:     VecNorm(W2,NORM_2,&a2);
    168:     if (a1 != 0.0) {
    169:       PetscInfo1(snes,"||J^T(F-Ax)||/||F-AX|| %g near zero implies inconsistent rhs\n",(double)(a2/a1));
    170:     }
    171:   }
    172:   return(0);
    173: }

    175: /*
    176:   SNESConvergedDefault_VI - Checks the convergence of the semismooth newton algorithm.

    178:   Notes:
    179:   The convergence criterion currently implemented is
    180:   merit < abstol
    181:   merit < rtol*merit_initial
    182: */
    183: PetscErrorCode SNESConvergedDefault_VI(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gradnorm,PetscReal fnorm,SNESConvergedReason *reason,void *dummy)
    184: {

    191:   *reason = SNES_CONVERGED_ITERATING;

    193:   if (!it) {
    194:     /* set parameter for default relative tolerance convergence test */
    195:     snes->ttol = fnorm*snes->rtol;
    196:   }
    197:   if (fnorm != fnorm) {
    198:     PetscInfo(snes,"Failed to converged, function norm is NaN\n");
    199:     *reason = SNES_DIVERGED_FNORM_NAN;
    200:   } else if (fnorm < snes->abstol && (it || !snes->forceiteration)) {
    201:     PetscInfo2(snes,"Converged due to function norm %g < %g\n",(double)fnorm,(double)snes->abstol);
    202:     *reason = SNES_CONVERGED_FNORM_ABS;
    203:   } else if (snes->nfuncs >= snes->max_funcs && snes->max_funcs >= 0) {
    204:     PetscInfo2(snes,"Exceeded maximum number of function evaluations: %D > %D\n",snes->nfuncs,snes->max_funcs);
    205:     *reason = SNES_DIVERGED_FUNCTION_COUNT;
    206:   }

    208:   if (it && !*reason) {
    209:     if (fnorm < snes->ttol) {
    210:       PetscInfo2(snes,"Converged due to function norm %g < %g (relative tolerance)\n",(double)fnorm,(double)snes->ttol);
    211:       *reason = SNES_CONVERGED_FNORM_RELATIVE;
    212:     }
    213:   }
    214:   return(0);
    215: }

    217: /* -------------------------------------------------------------------------- */
    218: /*
    219:    SNESVIProjectOntoBounds - Projects X onto the feasible region so that Xl[i] <= X[i] <= Xu[i] for i = 1...n.

    221:    Input Parameters:
    222: .  SNES - nonlinear solver context

    224:    Output Parameters:
    225: .  X - Bound projected X

    227: */

    229: PetscErrorCode SNESVIProjectOntoBounds(SNES snes,Vec X)
    230: {
    231:   PetscErrorCode    ierr;
    232:   const PetscScalar *xl,*xu;
    233:   PetscScalar       *x;
    234:   PetscInt          i,n;

    237:   VecGetLocalSize(X,&n);
    238:   VecGetArray(X,&x);
    239:   VecGetArrayRead(snes->xl,&xl);
    240:   VecGetArrayRead(snes->xu,&xu);

    242:   for (i = 0; i<n; i++) {
    243:     if (PetscRealPart(x[i]) < PetscRealPart(xl[i])) x[i] = xl[i];
    244:     else if (PetscRealPart(x[i]) > PetscRealPart(xu[i])) x[i] = xu[i];
    245:   }
    246:   VecRestoreArray(X,&x);
    247:   VecRestoreArrayRead(snes->xl,&xl);
    248:   VecRestoreArrayRead(snes->xu,&xu);
    249:   return(0);
    250: }

    252: /*
    253:    SNESVIGetActiveSetIndices - Gets the global indices for the active set variables

    255:    Input parameter:
    256: .  snes - the SNES context
    257: .  X    - the snes solution vector
    258: .  F    - the nonlinear function vector

    260:    Output parameter:
    261: .  ISact - active set index set
    262:  */
    263: PetscErrorCode SNESVIGetActiveSetIS(SNES snes,Vec X,Vec F,IS *ISact)
    264: {
    265:   PetscErrorCode    ierr;
    266:   Vec               Xl=snes->xl,Xu=snes->xu;
    267:   const PetscScalar *x,*f,*xl,*xu;
    268:   PetscInt          *idx_act,i,nlocal,nloc_isact=0,ilow,ihigh,i1=0;
    269:   PetscReal         zerotolerance = snes->vizerotolerance;

    272:   VecGetLocalSize(X,&nlocal);
    273:   VecGetOwnershipRange(X,&ilow,&ihigh);
    274:   VecGetArrayRead(X,&x);
    275:   VecGetArrayRead(Xl,&xl);
    276:   VecGetArrayRead(Xu,&xu);
    277:   VecGetArrayRead(F,&f);
    278:   /* Compute active set size */
    279:   for (i=0; i < nlocal;i++) {
    280:     if (!((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0))) nloc_isact++;
    281:   }

    283:   PetscMalloc1(nloc_isact,&idx_act);

    285:   /* Set active set indices */
    286:   for (i=0; i < nlocal; i++) {
    287:     if (!((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0))) idx_act[i1++] = ilow+i;
    288:   }

    290:   /* Create active set IS */
    291:   ISCreateGeneral(PetscObjectComm((PetscObject)snes),nloc_isact,idx_act,PETSC_OWN_POINTER,ISact);

    293:   VecRestoreArrayRead(X,&x);
    294:   VecRestoreArrayRead(Xl,&xl);
    295:   VecRestoreArrayRead(Xu,&xu);
    296:   VecRestoreArrayRead(F,&f);
    297:   return(0);
    298: }

    300: PetscErrorCode SNESVICreateIndexSets_RS(SNES snes,Vec X,Vec F,IS *ISact,IS *ISinact)
    301: {
    303:   PetscInt       rstart,rend;

    306:   SNESVIGetActiveSetIS(snes,X,F,ISact);
    307:   VecGetOwnershipRange(X,&rstart,&rend);
    308:   ISComplement(*ISact,rstart,rend,ISinact);
    309:   return(0);
    310: }

    312: PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES snes,Vec F,Vec X, PetscReal *fnorm)
    313: {
    314:   PetscErrorCode    ierr;
    315:   const PetscScalar *x,*xl,*xu,*f;
    316:   PetscInt          i,n;
    317:   PetscReal         rnorm,zerotolerance = snes->vizerotolerance;

    320:   VecGetLocalSize(X,&n);
    321:   VecGetArrayRead(snes->xl,&xl);
    322:   VecGetArrayRead(snes->xu,&xu);
    323:   VecGetArrayRead(X,&x);
    324:   VecGetArrayRead(F,&f);
    325:   rnorm = 0.0;
    326:   for (i=0; i<n; i++) {
    327:     if (((PetscRealPart(x[i]) > PetscRealPart(xl[i]) + zerotolerance || (PetscRealPart(f[i]) <= 0.0)) && ((PetscRealPart(x[i]) < PetscRealPart(xu[i]) - zerotolerance) || PetscRealPart(f[i]) >= 0.0))) rnorm += PetscRealPart(PetscConj(f[i])*f[i]);
    328:   }
    329:   VecRestoreArrayRead(F,&f);
    330:   VecRestoreArrayRead(snes->xl,&xl);
    331:   VecRestoreArrayRead(snes->xu,&xu);
    332:   VecRestoreArrayRead(X,&x);
    333:   MPIU_Allreduce(&rnorm,fnorm,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)snes));
    334:   *fnorm = PetscSqrtReal(*fnorm);
    335:   return(0);
    336: }

    338: PetscErrorCode SNESVIDMComputeVariableBounds(SNES snes,Vec xl, Vec xu)
    339: {

    343:   DMComputeVariableBounds(snes->dm, xl, xu);
    344:   return(0);
    345: }

    347: /* -------------------------------------------------------------------------- */
    348: /*
    349:    SNESSetUp_VI - Does setup common to all VI solvers -- basically makes sure bounds have been properly set up
    350:    of the SNESVI nonlinear solver.

    352:    Input Parameter:
    353: .  snes - the SNES context

    355:    Application Interface Routine: SNESSetUp()

    357:    Notes:
    358:    For basic use of the SNES solvers, the user need not explicitly call
    359:    SNESSetUp(), since these actions will automatically occur during
    360:    the call to SNESSolve().
    361:  */
    362: PetscErrorCode SNESSetUp_VI(SNES snes)
    363: {
    365:   PetscInt       i_start[3],i_end[3];

    368:   SNESSetWorkVecs(snes,1);
    369:   SNESSetUpMatrices(snes);

    371:   if (!snes->ops->computevariablebounds && snes->dm) {
    372:     PetscBool flag;
    373:     DMHasVariableBounds(snes->dm, &flag);
    374:     if (flag) {
    375:       snes->ops->computevariablebounds = SNESVIDMComputeVariableBounds;
    376:     }
    377:   }
    378:   if (!snes->usersetbounds) {
    379:     if (snes->ops->computevariablebounds) {
    380:       if (!snes->xl) {VecDuplicate(snes->vec_sol,&snes->xl);}
    381:       if (!snes->xu) {VecDuplicate(snes->vec_sol,&snes->xu);}
    382:       (*snes->ops->computevariablebounds)(snes,snes->xl,snes->xu);
    383:     } else if (!snes->xl && !snes->xu) {
    384:       /* If the lower and upper bound on variables are not set, set it to -Inf and Inf */
    385:       VecDuplicate(snes->vec_sol, &snes->xl);
    386:       VecSet(snes->xl,PETSC_NINFINITY);
    387:       VecDuplicate(snes->vec_sol, &snes->xu);
    388:       VecSet(snes->xu,PETSC_INFINITY);
    389:     } else {
    390:       /* Check if lower bound, upper bound and solution vector distribution across the processors is identical */
    391:       VecGetOwnershipRange(snes->vec_sol,i_start,i_end);
    392:       VecGetOwnershipRange(snes->xl,i_start+1,i_end+1);
    393:       VecGetOwnershipRange(snes->xu,i_start+2,i_end+2);
    394:       if ((i_start[0] != i_start[1]) || (i_start[0] != i_start[2]) || (i_end[0] != i_end[1]) || (i_end[0] != i_end[2]))
    395:         SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Distribution of lower bound, upper bound and the solution vector should be identical across all the processors.");
    396:     }
    397:   }
    398:   return(0);
    399: }
    400: /* -------------------------------------------------------------------------- */
    401: PetscErrorCode SNESReset_VI(SNES snes)
    402: {

    406:   VecDestroy(&snes->xl);
    407:   VecDestroy(&snes->xu);
    408:   snes->usersetbounds = PETSC_FALSE;
    409:   return(0);
    410: }

    412: /*
    413:    SNESDestroy_VI - Destroys the private SNES_VI context that was created
    414:    with SNESCreate_VI().

    416:    Input Parameter:
    417: .  snes - the SNES context

    419:    Application Interface Routine: SNESDestroy()
    420:  */
    421: PetscErrorCode SNESDestroy_VI(SNES snes)
    422: {

    426:   PetscFree(snes->data);

    428:   /* clear composed functions */
    429:   PetscObjectComposeFunction((PetscObject)snes,"SNESLineSearchSet_C",NULL);
    430:   PetscObjectComposeFunction((PetscObject)snes,"SNESLineSearchSetDefaultMonitor_C",NULL);
    431:   return(0);
    432: }

    434: /*@
    435:    SNESVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu.

    437:    Input Parameters:
    438: +  snes - the SNES context.
    439: .  xl   - lower bound.
    440: -  xu   - upper bound.

    442:    Notes:
    443:    If this routine is not called then the lower and upper bounds are set to
    444:    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().

    446:    Level: advanced

    448: @*/
    449: PetscErrorCode SNESVISetVariableBounds(SNES snes, Vec xl, Vec xu)
    450: {
    451:   PetscErrorCode ierr,(*f)(SNES,Vec,Vec);

    457:   PetscObjectQueryFunction((PetscObject)snes,"SNESVISetVariableBounds_C",&f);
    458:   if (!f) {
    459:     SNESVISetVariableBounds_VI(snes, xl, xu);
    460:   } else {
    461:     PetscUseMethod(snes,"SNESVISetVariableBounds_C",(SNES,Vec,Vec),(snes,xl,xu));
    462:   }
    463:   snes->usersetbounds = PETSC_TRUE;
    464:   return(0);
    465: }

    467: PetscErrorCode SNESVISetVariableBounds_VI(SNES snes,Vec xl,Vec xu)
    468: {
    469:   PetscErrorCode    ierr;
    470:   const PetscScalar *xxl,*xxu;
    471:   PetscInt          i,n, cnt = 0;

    474:   SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
    475:   if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call SNESSetFunction() or SNESSetDM() first");
    476:   {
    477:     PetscInt xlN,xuN,N;
    478:     VecGetSize(xl,&xlN);
    479:     VecGetSize(xu,&xuN);
    480:     VecGetSize(snes->vec_func,&N);
    481:     if (xlN != N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Incompatible vector lengths lower bound = %D solution vector = %D",xlN,N);
    482:     if (xuN != N) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Incompatible vector lengths: upper bound = %D solution vector = %D",xuN,N);
    483:   }
    484:   PetscObjectReference((PetscObject)xl);
    485:   PetscObjectReference((PetscObject)xu);
    486:   VecDestroy(&snes->xl);
    487:   VecDestroy(&snes->xu);
    488:   snes->xl = xl;
    489:   snes->xu = xu;
    490:   VecGetLocalSize(xl,&n);
    491:   VecGetArrayRead(xl,&xxl);
    492:   VecGetArrayRead(xu,&xxu);
    493:   for (i=0; i<n; i++) cnt += ((xxl[i] != PETSC_NINFINITY) || (xxu[i] != PETSC_INFINITY));

    495:   MPIU_Allreduce(&cnt,&snes->ntruebounds,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)snes));
    496:   VecRestoreArrayRead(xl,&xxl);
    497:   VecRestoreArrayRead(xu,&xxu);
    498:   return(0);
    499: }

    501: PetscErrorCode SNESSetFromOptions_VI(PetscOptionItems *PetscOptionsObject,SNES snes)
    502: {
    504:   PetscBool      flg = PETSC_FALSE;

    507:   PetscOptionsHead(PetscOptionsObject,"SNES VI options");
    508:   PetscOptionsReal("-snes_vi_zero_tolerance","Tolerance for considering x[] value to be on a bound","None",snes->vizerotolerance,&snes->vizerotolerance,NULL);
    509:   PetscOptionsBool("-snes_vi_monitor","Monitor all non-active variables","SNESMonitorResidual",flg,&flg,NULL);
    510:   if (flg) {
    511:     SNESMonitorSet(snes,SNESMonitorVI,PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)),NULL);
    512:   }
    513:   flg = PETSC_FALSE;
    514:   PetscOptionsBool("-snes_vi_monitor_residual","Monitor residual all non-active variables; using zero for active constraints","SNESMonitorVIResidual",flg,&flg,NULL);
    515:   if (flg) {
    516:     SNESMonitorSet(snes,SNESVIMonitorResidual,PETSC_VIEWER_DRAW_(PetscObjectComm((PetscObject)snes)),NULL);
    517:   }
    518:   PetscOptionsTail();
    519:   return(0);
    520: }