コード例 #1
0
/*@
   PCMGSetCycleType - Sets the type cycles to use.  Use PCMGSetCycleTypeOnLevel() for more
   complicated cycling.

   Logically Collective on PC

   Input Parameters:
+  pc - the multigrid context
-  PC_MG_CYCLE_V or PC_MG_CYCLE_W

   Options Database Key:
$  -pc_mg_cycle_type v or w

   Level: advanced

.keywords: MG, set, cycles, V-cycle, W-cycle, multigrid

.seealso: PCMGSetCycleTypeOnLevel()
@*/
PetscErrorCode  PCMGSetCycleType(PC pc,PCMGCycleType n)
{
    PC_MG        *mg        = (PC_MG*)pc->data;
    PC_MG_Levels **mglevels = mg->levels;
    PetscInt     i,levels;

    PetscFunctionBegin;
    PetscValidHeaderSpecific(pc,PC_CLASSID,1);
    if (!mglevels) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must set MG levels before calling");
    PetscValidLogicalCollectiveInt(pc,n,2);
    levels = mglevels[0]->levels;

    for (i=0; i<levels; i++) mglevels[i]->cycles = n;
    PetscFunctionReturn(0);
}
コード例 #2
0
/*@
   EPSSetDimensions - Sets the number of eigenvalues to compute
   and the dimension of the subspace.

   Logically Collective on EPS

   Input Parameters:
+  eps - the eigensolver context
.  nev - number of eigenvalues to compute
.  ncv - the maximum dimension of the subspace to be used by the solver
-  mpd - the maximum dimension allowed for the projected problem

   Options Database Keys:
+  -eps_nev <nev> - Sets the number of eigenvalues
.  -eps_ncv <ncv> - Sets the dimension of the subspace
-  -eps_mpd <mpd> - Sets the maximum projected dimension

   Notes:
   Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
   dependent on the solution method.

   The parameters ncv and mpd are intimately related, so that the user is advised
   to set one of them at most. Normal usage is that
   (a) in cases where nev is small, the user sets ncv (a reasonable default is 2*nev); and
   (b) in cases where nev is large, the user sets mpd.

   The value of ncv should always be between nev and (nev+mpd), typically
   ncv=nev+mpd. If nev is not too large, mpd=nev is a reasonable choice, otherwise
   a smaller value should be used.

   When computing all eigenvalues in an interval, see EPSSetInterval(), these
   parameters lose relevance, and tuning must be done with
   EPSKrylovSchurSetDimensions().

   Level: intermediate

.seealso: EPSGetDimensions(), EPSSetInterval(), EPSKrylovSchurSetDimensions()
@*/
PetscErrorCode EPSSetDimensions(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
{
  PetscFunctionBegin;
  PetscValidHeaderSpecific(eps,EPS_CLASSID,1);
  PetscValidLogicalCollectiveInt(eps,nev,2);
  PetscValidLogicalCollectiveInt(eps,ncv,3);
  PetscValidLogicalCollectiveInt(eps,mpd,4);
  if (nev<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
  eps->nev = nev;
  if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    eps->ncv = 0;
  } else {
    if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    eps->ncv = ncv;
  }
  if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    eps->mpd = 0;
  } else {
    if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    eps->mpd = mpd;
  }
  eps->state = EPS_STATE_INITIAL;
  PetscFunctionReturn(0);
}
コード例 #3
0
/*@
   SVDComputeResidualNorms - Computes the norms of the residual vectors associated with
   the i-th computed singular triplet.

   Collective on SVD

   Input Parameters:
+  svd  - the singular value solver context
-  i    - the solution index

   Output Parameters:
+  norm1 - the norm ||A*v-sigma*u||_2 where sigma is the
           singular value, u and v are the left and right singular vectors.
-  norm2 - the norm ||A^T*u-sigma*v||_2 with the same sigma, u and v

   Note:
   The index i should be a value between 0 and nconv-1 (see SVDGetConverged()).
   Both output parameters can be NULL on input if not needed.

   Level: beginner

.seealso: SVDSolve(), SVDGetConverged(), SVDComputeRelativeError()
@*/
PetscErrorCode SVDComputeResidualNorms(SVD svd,PetscInt i,PetscReal *norm1,PetscReal *norm2)
{
  PetscErrorCode ierr;
  Vec            u,v,x = NULL,y = NULL;
  PetscReal      sigma;
  PetscInt       M,N;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
  PetscValidLogicalCollectiveInt(svd,i,2);
  if (svd->reason == SVD_CONVERGED_ITERATING) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_ARG_WRONGSTATE,"SVDSolve must be called first");
  if (i<0 || i>=svd->nconv) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_ARG_OUTOFRANGE,"Argument 2 out of range");

  ierr = MatGetVecs(svd->OP,&v,&u);CHKERRQ(ierr);
  ierr = SVDGetSingularTriplet(svd,i,&sigma,u,v);CHKERRQ(ierr);
  if (norm1) {
    ierr = VecDuplicate(u,&x);CHKERRQ(ierr);
    ierr = MatMult(svd->OP,v,x);CHKERRQ(ierr);
    ierr = VecAXPY(x,-sigma,u);CHKERRQ(ierr);
    ierr = VecNorm(x,NORM_2,norm1);CHKERRQ(ierr);
  }
  if (norm2) {
    ierr = VecDuplicate(v,&y);CHKERRQ(ierr);
    if (svd->A && svd->AT) {
      ierr = MatGetSize(svd->OP,&M,&N);CHKERRQ(ierr);
      if (M<N) {
        ierr = MatMult(svd->A,u,y);CHKERRQ(ierr);
      } else {
        ierr = MatMult(svd->AT,u,y);CHKERRQ(ierr);
      }
    } else {
#if defined(PETSC_USE_COMPLEX)
      ierr = MatMultHermitianTranspose(svd->OP,u,y);CHKERRQ(ierr);
#else
      ierr = MatMultTranspose(svd->OP,u,y);CHKERRQ(ierr);
#endif
    }
    ierr = VecAXPY(y,-sigma,v);CHKERRQ(ierr);
    ierr = VecNorm(y,NORM_2,norm2);CHKERRQ(ierr);
  }

  ierr = VecDestroy(&v);CHKERRQ(ierr);
  ierr = VecDestroy(&u);CHKERRQ(ierr);
  ierr = VecDestroy(&x);CHKERRQ(ierr);
  ierr = VecDestroy(&y);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #4
0
/*@
   PEPGetEigenpair - Gets the i-th solution of the eigenproblem as computed by
   PEPSolve(). The solution consists in both the eigenvalue and the eigenvector.

   Logically Collective on EPS

   Input Parameters:
+  pep - polynomial eigensolver context
-  i   - index of the solution

   Output Parameters:
+  eigr - real part of eigenvalue
.  eigi - imaginary part of eigenvalue
.  Vr   - real part of eigenvector
-  Vi   - imaginary part of eigenvector

   Notes:
   If the eigenvalue is real, then eigi and Vi are set to zero. If PETSc is
   configured with complex scalars the eigenvalue is stored
   directly in eigr (eigi is set to zero) and the eigenvector in Vr (Vi is
   set to zero).

   The index i should be a value between 0 and nconv-1 (see PEPGetConverged()).
   Eigenpairs are indexed according to the ordering criterion established
   with PEPSetWhichEigenpairs().

   Level: beginner

.seealso: PEPSolve(), PEPGetConverged(), PEPSetWhichEigenpairs()
@*/
PetscErrorCode PEPGetEigenpair(PEP pep,PetscInt i,PetscScalar *eigr,PetscScalar *eigi,Vec Vr,Vec Vi)
{
  PetscInt       k;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(pep,PEP_CLASSID,1);
  PetscValidLogicalCollectiveInt(pep,i,2);
  if (Vr) { PetscValidHeaderSpecific(Vr,VEC_CLASSID,5); PetscCheckSameComm(pep,1,Vr,5); }
  if (Vi) { PetscValidHeaderSpecific(Vi,VEC_CLASSID,6); PetscCheckSameComm(pep,1,Vi,6); }
  PEPCheckSolved(pep,1);
  if (i<0 || i>=pep->nconv) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Argument 2 out of range");

  ierr = PEPComputeVectors(pep);CHKERRQ(ierr);
  if (!pep->perm) k = i;
  else k = pep->perm[i];

  /* eigenvalue */
#if defined(PETSC_USE_COMPLEX)
  if (eigr) *eigr = pep->eigr[k];
  if (eigi) *eigi = 0;
#else
  if (eigr) *eigr = pep->eigr[k];
  if (eigi) *eigi = pep->eigi[k];
#endif

  /* eigenvector */
#if defined(PETSC_USE_COMPLEX)
  if (Vr) { ierr = BVCopyVec(pep->V,k,Vr);CHKERRQ(ierr); }
  if (Vi) { ierr = VecSet(Vi,0.0);CHKERRQ(ierr); }
#else
  if (pep->eigi[k]>0) { /* first value of conjugate pair */
    if (Vr) { ierr = BVCopyVec(pep->V,k,Vr);CHKERRQ(ierr); }
    if (Vi) { ierr = BVCopyVec(pep->V,k+1,Vi);CHKERRQ(ierr); }
  } else if (pep->eigi[k]<0) { /* second value of conjugate pair */
    if (Vr) { ierr = BVCopyVec(pep->V,k-1,Vr);CHKERRQ(ierr); }
    if (Vi) {
      ierr = BVCopyVec(pep->V,k,Vi);CHKERRQ(ierr);
      ierr = VecScale(Vi,-1.0);CHKERRQ(ierr);
    }
  } else { /* real eigenvalue */
    if (Vr) { ierr = BVCopyVec(pep->V,k,Vr);CHKERRQ(ierr); }
    if (Vi) { ierr = VecSet(Vi,0.0);CHKERRQ(ierr); }
  }
#endif
  PetscFunctionReturn(0);
}
コード例 #5
0
/*@C
    PetscViewerDrawBaseSet - sets the base integer that is added to the windownumber passed to PetscViewerDrawGetDraw()

    Logically Collective on PetscViewer

    Input Parameters:
+   viewer - the PetscViewer (created with PetscViewerDrawOpen())
-   windownumber - value to set the base

    Level: developer

   Concepts: drawing^accessing PetscDraw context from PetscViewer
   Concepts: graphics

.seealso: PetscViewerDrawGetLG(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen(), PetscViewerDrawGetDraw(), PetscViewerDrawBaseAdd()
@*/
PetscErrorCode  PetscViewerDrawBaseSet(PetscViewer viewer,PetscInt windownumber)
{
  PetscViewer_Draw *vdraw;
  PetscErrorCode   ierr;
  PetscBool        isdraw;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  PetscValidLogicalCollectiveInt(viewer,windownumber,2);
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (!isdraw) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be draw type PetscViewer");
  vdraw = (PetscViewer_Draw*)viewer->data;

  if (windownumber < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Resulting base %D cannot be negative",windownumber);
  vdraw->draw_base = windownumber;
  PetscFunctionReturn(0);
}
コード例 #6
0
ファイル: hists.c プロジェクト: pombredanne/petsc
/*@C
   PetscDrawHGCreate - Creates a histogram data structure.

   Collective over PetscDraw

   Input Parameters:
+  draw  - The window where the graph will be made
-  bins - The number of bins to use

   Output Parameters:
.  hist - The histogram context

   Level: intermediate

   Concepts: histogram^creating

.seealso: PetscDrawHGDestroy()

@*/
PetscErrorCode  PetscDrawHGCreate(PetscDraw draw, int bins, PetscDrawHG *hist)
{
  PetscBool      isnull;
  PetscDrawHG    h;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw, PETSC_DRAW_CLASSID,1);
  PetscValidLogicalCollectiveInt(draw,bins,2);
  PetscValidPointer(hist,3);

  ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr);
  if (isnull) {*hist = NULL; PetscFunctionReturn(0);}

  ierr = PetscHeaderCreate(h, PETSC_DRAWHG_CLASSID,  "PetscDrawHG", "Histogram", "Draw", PetscObjectComm((PetscObject)draw), PetscDrawHGDestroy, NULL);CHKERRQ(ierr);
  ierr = PetscLogObjectParent((PetscObject)draw,(PetscObject)h);CHKERRQ(ierr);

  ierr = PetscObjectReference((PetscObject)draw);CHKERRQ(ierr);
  h->win = draw;

  h->view        = NULL;
  h->destroy     = NULL;
  h->color       = PETSC_DRAW_GREEN;
  h->xmin        = PETSC_MAX_REAL;
  h->xmax        = PETSC_MIN_REAL;
  h->ymin        = 0.;
  h->ymax        = 1.;
  h->numBins     = bins;
  h->maxBins     = bins;

  ierr = PetscMalloc1(h->maxBins,&h->bins);CHKERRQ(ierr);

  h->numValues   = 0;
  h->maxValues   = CHUNKSIZE;
  h->calcStats   = PETSC_FALSE;
  h->integerBins = PETSC_FALSE;

  ierr = PetscMalloc1(h->maxValues,&h->values);CHKERRQ(ierr);
  ierr = PetscLogObjectMemory((PetscObject)h,(h->maxBins + h->maxValues)*sizeof(PetscReal));CHKERRQ(ierr);

  ierr = PetscDrawAxisCreate(draw,&h->axis);CHKERRQ(ierr);
  ierr = PetscLogObjectParent((PetscObject)h,(PetscObject)h->axis);CHKERRQ(ierr);

  *hist = h;
  PetscFunctionReturn(0);
}
コード例 #7
0
ファイル: mffd.c プロジェクト: petsc/petsc
/*@
   MatMFFDSetHHistory - Sets an array to collect a history of the
   differencing values (h) computed for the matrix-free product.

   Logically Collective on Mat

   Input Parameters:
+  J - the matrix-free matrix context
.  histroy - space to hold the history
-  nhistory - number of entries in history, if more entries are generated than
              nhistory, then the later ones are discarded

   Level: advanced

   Notes:
   Use MatMFFDResetHHistory() to reset the history counter and collect
   a new batch of differencing parameters, h.

.keywords: SNES, matrix-free, h history, differencing history

.seealso: MatMFFDGetH(), MatCreateSNESMF(),
          MatMFFDResetHHistory(), MatMFFDSetFunctionError()

@*/
PetscErrorCode  MatMFFDSetHHistory(Mat J,PetscScalar history[],PetscInt nhistory)
{
  MatMFFD        ctx = (MatMFFD)J->data;
  PetscErrorCode ierr;
  PetscBool      match;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(J,MAT_CLASSID,1);
  if (history) PetscValidPointer(history,2);
  PetscValidLogicalCollectiveInt(J,nhistory,3);
  ierr = PetscObjectTypeCompare((PetscObject)J,MATMFFD,&match);CHKERRQ(ierr);
  if (!match) SETERRQ(PetscObjectComm((PetscObject)J),PETSC_ERR_ARG_WRONG,"Not a MFFD matrix");
  ctx->historyh    = history;
  ctx->maxcurrenth = nhistory;
  ctx->currenth    = 0.;
  PetscFunctionReturn(0);
}
コード例 #8
0
ファイル: hists.c プロジェクト: pombredanne/petsc
/*@
   PetscDrawHGSetNumberBins - Change the number of bins that are to be drawn.

   Not Collective (ignored except on processor 0 of PetscDrawHG)

   Input Parameter:
+  hist - The histogram context.
-  bins  - The number of bins.

   Level: intermediate

   Concepts: histogram^setting number of bins

@*/
PetscErrorCode  PetscDrawHGSetNumberBins(PetscDrawHG hist, int bins)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  if (!hist) PetscFunctionReturn(0);
  PetscValidHeaderSpecific(hist,PETSC_DRAWHG_CLASSID,1);
  PetscValidLogicalCollectiveInt(hist,bins,2);

  if (hist->maxBins < bins) {
    ierr = PetscFree(hist->bins);CHKERRQ(ierr);
    ierr = PetscMalloc1(bins, &hist->bins);CHKERRQ(ierr);
    ierr = PetscLogObjectMemory((PetscObject)hist, (bins - hist->maxBins) * sizeof(PetscReal));CHKERRQ(ierr);
    hist->maxBins = bins;
  }
  hist->numBins = bins;
  PetscFunctionReturn(0);
}
コード例 #9
0
/*@
   PEPComputeRelativeError - Computes the relative error bound associated
   with the i-th computed eigenpair.

   Collective on PEP

   Input Parameter:
+  pep - the polynomial eigensolver context
-  i   - the solution index

   Output Parameter:
.  error - the relative error bound, computed as ||P(l)x||_2/||lx||_2 where
   l is the eigenvalue and x is the eigenvector.

   Level: beginner

.seealso: PEPSolve(), PEPComputeResidualNorm(), PEPGetErrorEstimate()
@*/
PetscErrorCode PEPComputeRelativeError(PEP pep,PetscInt i,PetscReal *error)
{
  PetscErrorCode ierr;
  Vec            xr,xi;
  PetscScalar    kr,ki;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(pep,PEP_CLASSID,1);
  PetscValidLogicalCollectiveInt(pep,i,2);
  PetscValidPointer(error,3);
  PEPCheckSolved(pep,1);
  ierr = BVGetVec(pep->V,&xr);CHKERRQ(ierr);
  ierr = BVGetVec(pep->V,&xi);CHKERRQ(ierr);
  ierr = PEPGetEigenpair(pep,i,&kr,&ki,xr,xi);CHKERRQ(ierr);
  ierr = PEPComputeRelativeError_Private(pep,kr,ki,xr,xi,error);CHKERRQ(ierr);
  ierr = VecDestroy(&xr);CHKERRQ(ierr);
  ierr = VecDestroy(&xi);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #10
0
/*@
   EPSComputeRelativeError - Computes the relative error bound associated
   with the i-th computed eigenpair.

   Collective on EPS

   Input Parameter:
+  eps - the eigensolver context
-  i   - the solution index

   Output Parameter:
.  error - the relative error bound, computed as ||Ax-kBx||_2/||kx||_2 where
   k is the eigenvalue and x is the eigenvector.
   If k=0 the relative error is computed as ||Ax||_2/||x||_2.

   Level: beginner

.seealso: EPSSolve(), EPSComputeResidualNorm(), EPSGetErrorEstimate()
@*/
PetscErrorCode EPSComputeRelativeError(EPS eps,PetscInt i,PetscReal *error)
{
  PetscErrorCode ierr;
  Vec            xr,xi;
  PetscScalar    kr,ki;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(eps,EPS_CLASSID,1);
  PetscValidLogicalCollectiveInt(eps,i,2);
  PetscValidPointer(error,3);
  EPSCheckSolved(eps,1);
  ierr = BVGetVec(eps->V,&xr);CHKERRQ(ierr);
  ierr = BVGetVec(eps->V,&xi);CHKERRQ(ierr);
  ierr = EPSGetEigenpair(eps,i,&kr,&ki,xr,xi);CHKERRQ(ierr);
  ierr = EPSComputeRelativeError_Private(eps,kr,ki,xr,xi,error);CHKERRQ(ierr);
  ierr = VecDestroy(&xr);CHKERRQ(ierr);
  ierr = VecDestroy(&xi);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #11
0
/*@
   BVScaleColumn - Scale one column of a BV.

   Logically Collective on BV

   Input Parameters:
+  bv    - basis vectors
.  j     - column number to be scaled
-  alpha - scaling factor

   Level: intermediate

.seealso: BVScale(), BVSetActiveColumns()
@*/
PetscErrorCode BVScaleColumn(BV bv,PetscInt j,PetscScalar alpha)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(bv,BV_CLASSID,1);
  PetscValidLogicalCollectiveInt(bv,j,2);
  PetscValidLogicalCollectiveScalar(bv,alpha,3);
  PetscValidType(bv,1);
  BVCheckSizes(bv,1);

  if (j<0 || j>=bv->m) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Argument j has wrong value %D, the number of columns is %D",j,bv->m);
  if (!bv->n || alpha == (PetscScalar)1.0) PetscFunctionReturn(0);

  ierr = PetscLogEventBegin(BV_Scale,bv,0,0,0);CHKERRQ(ierr);
  ierr = (*bv->ops->scale)(bv,j,alpha);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(BV_Scale,bv,0,0,0);CHKERRQ(ierr);
  ierr = PetscObjectStateIncrease((PetscObject)bv);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #12
0
ファイル: bcgsl.c プロジェクト: hansec/petsc
/*@
   KSPBCGSLSetEll - Sets the number of search directions in BiCGStab(L).

   Logically Collective on KSP

   Input Parameters:
+  ksp - iterative context obtained from KSPCreate
-  ell - number of search directions

   Options Database Keys:

.  -ksp_bcgsl_ell ell

   Level: intermediate

   Notes:
   For large ell it is common for the polynomial update problem to become singular (due to happy breakdown for smallish
   test problems, but also for larger problems). Consequently, by default, the system is solved by pseudoinverse, which
   allows the iteration to complete successfully. See KSPBCGSLSetUsePseudoinverse() to switch to a conventional solve.

.keywords: KSP, BiCGStab(L), set, exact residuals,

.seealso: KSPBCGSLSetUsePseudoinverse()
@*/
PetscErrorCode  KSPBCGSLSetEll(KSP ksp, PetscInt ell)
{
  KSP_BCGSL      *bcgsl = (KSP_BCGSL*)ksp->data;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  if (ell < 1) SETERRQ(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_OUTOFRANGE, "KSPBCGSLSetEll: second argument must be positive");
  PetscValidLogicalCollectiveInt(ksp,ell,2);

  if (!ksp->setupstage) bcgsl->ell = ell;
  else if (bcgsl->ell != ell) {
    /* free the data structures, then create them again */
    ierr = VecDestroyVecs(ksp->nwork,&ksp->work);CHKERRQ(ierr);
    ierr = PetscFree5(AY0c,AYlc,AYtc,MZa,MZb);CHKERRQ(ierr);
    ierr = PetscFree4(bcgsl->work,bcgsl->s,bcgsl->u,bcgsl->v);CHKERRQ(ierr);

    bcgsl->ell      = ell;
    ksp->setupstage = KSP_SETUP_NEW;
  }
  PetscFunctionReturn(0);
}
コード例 #13
0
/*@
   EPSSetTolerances - Sets the tolerance and maximum iteration count used
   by the EPS convergence tests.

   Logically Collective on EPS

   Input Parameters:
+  eps - the eigensolver context
.  tol - the convergence tolerance
-  maxits - maximum number of iterations to use

   Options Database Keys:
+  -eps_tol <tol> - Sets the convergence tolerance
-  -eps_max_it <maxits> - Sets the maximum number of iterations allowed

   Notes:
   Use PETSC_DEFAULT for either argument to assign a reasonably good value.

   Level: intermediate

.seealso: EPSGetTolerances()
@*/
PetscErrorCode EPSSetTolerances(EPS eps,PetscReal tol,PetscInt maxits)
{
  PetscFunctionBegin;
  PetscValidHeaderSpecific(eps,EPS_CLASSID,1);
  PetscValidLogicalCollectiveReal(eps,tol,2);
  PetscValidLogicalCollectiveInt(eps,maxits,3);
  if (tol == PETSC_DEFAULT) {
    eps->tol   = PETSC_DEFAULT;
    eps->state = EPS_STATE_INITIAL;
  } else {
    if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    eps->tol = tol;
  }
  if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    eps->max_it = 0;
    eps->state  = EPS_STATE_INITIAL;
  } else {
    if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    eps->max_it = maxits;
  }
  PetscFunctionReturn(0);
}
コード例 #14
0
/*@
   MFNSetTolerances - Sets the tolerance and maximum iteration count used
   by the MFN convergence tests.

   Logically Collective on MFN

   Input Parameters:
+  mfn - the matrix function context
.  tol - the convergence tolerance
-  maxits - maximum number of iterations to use

   Options Database Keys:
+  -mfn_tol <tol> - Sets the convergence tolerance
-  -mfn_max_it <maxits> - Sets the maximum number of iterations allowed

   Notes:
   Use PETSC_DEFAULT for either argument to assign a reasonably good value.

   Level: intermediate

.seealso: MFNGetTolerances()
@*/
PetscErrorCode MFNSetTolerances(MFN mfn,PetscReal tol,PetscInt maxits)
{
  PetscFunctionBegin;
  PetscValidHeaderSpecific(mfn,MFN_CLASSID,1);
  PetscValidLogicalCollectiveReal(mfn,tol,2);
  PetscValidLogicalCollectiveInt(mfn,maxits,3);
  if (tol == PETSC_DEFAULT) {
    mfn->tol = PETSC_DEFAULT;
    mfn->setupcalled = 0;
  } else {
    if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    mfn->tol = tol;
  }
  if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    mfn->max_it = 0;
    mfn->setupcalled = 0;
  } else {
    if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    mfn->max_it = maxits;
  }
  PetscFunctionReturn(0);
}
コード例 #15
0
/*@
    PetscDrawLGCreate - Creates a line graph data structure.

    Collective on PetscDraw

    Input Parameters:
+   draw - the window where the graph will be made.
-   dim - the number of curves which will be drawn

    Output Parameters:
.   outlg - the line graph context

    Level: intermediate

    Notes: The MPI communicator that owns the PetscDraw owns this PetscDrawLG, but the calls to set options and add points are ignored on all processes except the
           zeroth MPI process in the communicator. All MPI processes in the communicator must call PetscDrawLGDraw() to display the updated graph.

    Concepts: line graph^creating

.seealso:  PetscDrawLGDestroy(), PetscDrawLGAddPoint(), PetscDrawLGAddCommonPoint(), PetscDrawLGAddPoints(), PetscDrawLGDraw(), PetscDrawLGSave(),
           PetscDrawLGView(), PetscDrawLGReset(), PetscDrawLGSetDimension(), PetscDrawLGGetDimension(), PetscDrawLGSetLegend(), PetscDrawLGGetAxis(),
           PetscDrawLGGetDraw(), PetscDrawLGSetUseMarkers(), PetscDrawLGSetLimits(), PetscDrawLGSetColors(), PetscDrawLGSetOptionsPrefix(), PetscDrawLGSetFromOptions()
@*/
PetscErrorCode  PetscDrawLGCreate(PetscDraw draw,PetscInt dim,PetscDrawLG *outlg)
{
  PetscDrawLG    lg;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw,PETSC_DRAW_CLASSID,1);
  PetscValidLogicalCollectiveInt(draw,dim,2);
  PetscValidPointer(outlg,3);

  ierr = PetscHeaderCreate(lg,PETSC_DRAWLG_CLASSID,"DrawLG","Line Graph","Draw",PetscObjectComm((PetscObject)draw),PetscDrawLGDestroy,NULL);CHKERRQ(ierr);
  ierr = PetscLogObjectParent((PetscObject)draw,(PetscObject)lg);CHKERRQ(ierr);
  ierr = PetscDrawLGSetOptionsPrefix(lg,((PetscObject)draw)->prefix);CHKERRQ(ierr);

  ierr = PetscObjectReference((PetscObject)draw);CHKERRQ(ierr);
  lg->win = draw;

  lg->view    = NULL;
  lg->destroy = NULL;
  lg->nopts   = 0;
  lg->dim     = dim;
  lg->xmin    = 1.e20;
  lg->ymin    = 1.e20;
  lg->xmax    = -1.e20;
  lg->ymax    = -1.e20;

  ierr = PetscMalloc2(dim*CHUNCKSIZE,&lg->x,dim*CHUNCKSIZE,&lg->y);CHKERRQ(ierr);
  ierr = PetscLogObjectMemory((PetscObject)lg,2*dim*CHUNCKSIZE*sizeof(PetscReal));CHKERRQ(ierr);

  lg->len         = dim*CHUNCKSIZE;
  lg->loc         = 0;
  lg->use_markers = PETSC_FALSE;

  ierr = PetscDrawAxisCreate(draw,&lg->axis);CHKERRQ(ierr);
  ierr = PetscLogObjectParent((PetscObject)lg,(PetscObject)lg->axis);CHKERRQ(ierr);

  *outlg = lg;
  PetscFunctionReturn(0);
}
コード例 #16
0
ファイル: mg.c プロジェクト: ziolai/petsc
/*@
   PCMGSetNumberSmoothUp - Sets the number of post-smoothing steps to use
   on all levels. Use PCMGGetSmootherUp() to set different numbers of
   post-smoothing steps on different levels.

   Logically Collective on PC

   Input Parameters:
+  mg - the multigrid context
-  n - the number of smoothing steps

   Options Database Key:
.  -pc_mg_smoothup <n> - Sets number of post-smoothing steps

   Level: advanced

   Note: this does not set a value on the coarsest grid, since we assume that
    there is no separate smooth up on the coarsest grid.

.keywords: MG, smooth, up, post-smoothing, steps, multigrid

.seealso: PCMGSetNumberSmoothDown()
@*/
PetscErrorCode  PCMGSetNumberSmoothUp(PC pc,PetscInt n)
{
  PC_MG          *mg        = (PC_MG*)pc->data;
  PC_MG_Levels   **mglevels = mg->levels;
  PetscErrorCode ierr;
  PetscInt       i,levels;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(pc,PC_CLASSID,1);
  if (!mglevels) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must set MG levels before calling");
  PetscValidLogicalCollectiveInt(pc,n,2);
  levels = mglevels[0]->levels;

  for (i=1; i<levels; i++) {
    /* make sure smoother up and down are different */
    ierr = PCMGGetSmootherUp(pc,i,NULL);CHKERRQ(ierr);
    ierr = KSPSetTolerances(mglevels[i]->smoothu,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,n);CHKERRQ(ierr);

    mg->default_smoothu = n;
  }
  PetscFunctionReturn(0);
}
コード例 #17
0
/*@
   EPSGetEigenvector - Gets the i-th right eigenvector as computed by EPSSolve().

   Logically Collective on EPS

   Input Parameters:
+  eps - eigensolver context
-  i   - index of the solution

   Output Parameters:
+  Vr   - real part of eigenvector
-  Vi   - imaginary part of eigenvector

   Notes:
   If the corresponding eigenvalue is real, then Vi is set to zero. If PETSc is
   configured with complex scalars the eigenvector is stored
   directly in Vr (Vi is set to zero).

   The index i should be a value between 0 and nconv-1 (see EPSGetConverged()).
   Eigenpairs are indexed according to the ordering criterion established
   with EPSSetWhichEigenpairs().

   The 2-norm of the eigenvector is one unless the problem is generalized
   Hermitian. In this case the eigenvector is normalized with respect to the
   norm defined by the B matrix.

   Level: beginner

.seealso: EPSSolve(), EPSGetConverged(), EPSSetWhichEigenpairs(), EPSGetEigenpair()
@*/
PetscErrorCode EPSGetEigenvector(EPS eps,PetscInt i,Vec Vr,Vec Vi)
{
  PetscErrorCode ierr;
  PetscInt       k;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(eps,EPS_CLASSID,1);
  PetscValidLogicalCollectiveInt(eps,i,2);
  PetscValidHeaderSpecific(Vr,VEC_CLASSID,3);
  PetscCheckSameComm(eps,1,Vr,3);
  if (Vi) { PetscValidHeaderSpecific(Vi,VEC_CLASSID,4); PetscCheckSameComm(eps,1,Vi,4); }
  EPSCheckSolved(eps,1);
  if (i<0 || i>=eps->nconv) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Argument 2 out of range");
  ierr = EPSComputeVectors(eps);CHKERRQ(ierr);
  if (!eps->perm) k = i;
  else k = eps->perm[i];
#if defined(PETSC_USE_COMPLEX)
  ierr = BVCopyVec(eps->V,k,Vr);CHKERRQ(ierr);
  if (Vi) { ierr = VecSet(Vi,0.0);CHKERRQ(ierr); }
#else
  if (eps->eigi[k] > 0) { /* first value of conjugate pair */
    ierr = BVCopyVec(eps->V,k,Vr);CHKERRQ(ierr);
    if (Vi) {
      ierr = BVCopyVec(eps->V,k+1,Vi);CHKERRQ(ierr);
    }
  } else if (eps->eigi[k] < 0) { /* second value of conjugate pair */
    ierr = BVCopyVec(eps->V,k-1,Vr);CHKERRQ(ierr);
    if (Vi) {
      ierr = BVCopyVec(eps->V,k,Vi);CHKERRQ(ierr);
      ierr = VecScale(Vi,-1.0);CHKERRQ(ierr);
    }
  } else { /* real eigenvalue */
    ierr = BVCopyVec(eps->V,k,Vr);CHKERRQ(ierr);
    if (Vi) { ierr = VecSet(Vi,0.0);CHKERRQ(ierr); }
  }
#endif
  PetscFunctionReturn(0);
}
コード例 #18
0
/*
   EPSGetStartVector - Generate a suitable vector to be used as the starting vector
   for the recurrence that builds the right subspace.

   Collective on EPS and Vec

   Input Parameters:
+  eps - the eigensolver context
-  i   - iteration number

   Output Parameters:
.  breakdown - flag indicating that a breakdown has occurred

   Notes:
   The start vector is computed from another vector: for the first step (i=0),
   the first initial vector is used (see EPSSetInitialSpace()); otherwise a random
   vector is created. Then this vector is forced to be in the range of OP (only
   for generalized definite problems) and orthonormalized with respect to all
   V-vectors up to i-1. The resulting vector is placed in V[i].

   The flag breakdown is set to true if either i=0 and the vector belongs to the
   deflation space, or i>0 and the vector is linearly dependent with respect
   to the V-vectors.
*/
PetscErrorCode EPSGetStartVector(EPS eps,PetscInt i,PetscBool *breakdown)
{
  PetscErrorCode ierr;
  PetscReal      norm;
  PetscBool      lindep;
  Vec            w,z;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(eps,EPS_CLASSID,1);
  PetscValidLogicalCollectiveInt(eps,i,2);

  /* For the first step, use the first initial vector, otherwise a random one */
  if (i>0 || eps->nini==0) {
    ierr = BVSetRandomColumn(eps->V,i,eps->rand);CHKERRQ(ierr);
  }
  ierr = BVGetVec(eps->V,&w);CHKERRQ(ierr);
  ierr = BVCopyVec(eps->V,i,w);CHKERRQ(ierr);

  /* Force the vector to be in the range of OP for definite generalized problems */
  ierr = BVGetColumn(eps->V,i,&z);CHKERRQ(ierr);
  if (eps->ispositive || (eps->isgeneralized && eps->ishermitian)) {
    ierr = STApply(eps->st,w,z);CHKERRQ(ierr);
  } else {
    ierr = VecCopy(w,z);CHKERRQ(ierr);
  }
  ierr = BVRestoreColumn(eps->V,i,&z);CHKERRQ(ierr);
  ierr = VecDestroy(&w);CHKERRQ(ierr);

  /* Orthonormalize the vector with respect to previous vectors */
  ierr = BVOrthogonalizeColumn(eps->V,i,NULL,&norm,&lindep);CHKERRQ(ierr);
  if (breakdown) *breakdown = lindep;
  else if (lindep || norm == 0.0) {
    if (i==0) SETERRQ(PetscObjectComm((PetscObject)eps),1,"Initial vector is zero or belongs to the deflation space");
    else SETERRQ(PetscObjectComm((PetscObject)eps),1,"Unable to generate more start vectors");
  }
  ierr = BVScaleColumn(eps->V,i,1.0/norm);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #19
0
ファイル: plexcreate.c プロジェクト: feelpp/debian-petsc
/*@
  DMPlexCreateBoxMesh - Creates a mesh on the tensor product of unit intervals (box).

  Collective on MPI_Comm

  Input Parameters:
+ comm - The communicator for the DM object
. dim - The spatial dimension
- interpolate - Flag to create intermediate mesh pieces (edges, faces)

  Output Parameter:
. dm  - The DM object

  Level: beginner

.keywords: DM, create
.seealso: DMSetType(), DMCreate()
@*/
PetscErrorCode DMPlexCreateBoxMesh(MPI_Comm comm, PetscInt dim, PetscBool interpolate, DM *dm)
{
  DM             boundary;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidPointer(dm, 4);
  ierr = DMCreate(comm, &boundary);CHKERRQ(ierr);
  PetscValidLogicalCollectiveInt(boundary,dim,2);
  ierr = DMSetType(boundary, DMPLEX);CHKERRQ(ierr);
  ierr = DMPlexSetDimension(boundary, dim-1);CHKERRQ(ierr);
  switch (dim) {
  case 2:
  {
    PetscReal lower[2] = {0.0, 0.0};
    PetscReal upper[2] = {1.0, 1.0};
    PetscInt  edges[2] = {2, 2};

    ierr = DMPlexCreateSquareBoundary(boundary, lower, upper, edges);CHKERRQ(ierr);
    break;
  }
  case 3:
  {
    PetscReal lower[3] = {0.0, 0.0, 0.0};
    PetscReal upper[3] = {1.0, 1.0, 1.0};
    PetscInt  faces[3] = {1, 1, 1};

    ierr = DMPlexCreateCubeBoundary(boundary, lower, upper, faces);CHKERRQ(ierr);
    break;
  }
  default:
    SETERRQ1(comm, PETSC_ERR_SUP, "Dimension not supported: %d", dim);
  }
  ierr = DMPlexGenerate(boundary, NULL, interpolate, dm);CHKERRQ(ierr);
  ierr = DMDestroy(&boundary);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #20
0
/*@
   BVSetRandomColumn - Set one column of a BV to random numbers.

   Logically Collective on BV

   Input Parameters:
+  bv   - basis vectors
.  j    - column number to be set
-  rctx - the random number context, formed by PetscRandomCreate(), or NULL and
          it will create one internally.

   Note:
   This operation is analogue to VecSetRandom - the difference is that the
   generated random vector is the same irrespective of the size of the
   communicator (if all processes pass a PetscRandom context initialized
   with the same seed).

   Level: advanced

.seealso: BVSetRandom(), BVSetActiveColumns()
@*/
PetscErrorCode BVSetRandomColumn(BV bv,PetscInt j,PetscRandom rctx)
{
  PetscErrorCode ierr;
  PetscRandom    rand=NULL;
  PetscInt       i,low,high;
  PetscScalar    *px,t;
  Vec            x;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(bv,BV_CLASSID,1);
  PetscValidLogicalCollectiveInt(bv,j,2);
  if (rctx) PetscValidHeaderSpecific(rctx,PETSC_RANDOM_CLASSID,3);
  else {
    ierr = PetscRandomCreate(PetscObjectComm((PetscObject)bv),&rand);CHKERRQ(ierr);
    ierr = PetscRandomSetSeed(rand,0x12345678);CHKERRQ(ierr);
    ierr = PetscRandomSetFromOptions(rand);CHKERRQ(ierr);
    rctx = rand;
  }
  PetscValidType(bv,1);
  BVCheckSizes(bv,1);
  if (j<0 || j>=bv->m) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Argument j has wrong value %D, the number of columns is %D",j,bv->m);

  ierr = PetscLogEventBegin(BV_SetRandom,bv,rctx,0,0);CHKERRQ(ierr);
  ierr = BVGetColumn(bv,j,&x);CHKERRQ(ierr);
  ierr = VecGetOwnershipRange(x,&low,&high);CHKERRQ(ierr);
  ierr = VecGetArray(x,&px);CHKERRQ(ierr);
  for (i=0;i<bv->N;i++) {
    ierr = PetscRandomGetValue(rctx,&t);CHKERRQ(ierr);
    if (i>=low && i<high) px[i-low] = t;
  }
  ierr = VecRestoreArray(x,&px);CHKERRQ(ierr);
  ierr = BVRestoreColumn(bv,j,&x);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(BV_SetRandom,bv,rctx,0,0);CHKERRQ(ierr);
  ierr = PetscRandomDestroy(&rand);CHKERRQ(ierr);
  ierr = PetscObjectStateIncrease((PetscObject)bv);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #21
0
/*@
   PetscDrawLGSetDimension - Change the number of lines that are to be drawn.

   Logically Collective on PetscDrawLG

   Input Parameter:
+  lg - the line graph context.
-  dim - the number of curves.

   Level: intermediate

   Concepts: line graph^setting number of lines

.seealso: PetscDrawLGCreate(), PetscDrawLGGetDimension()
@*/
PetscErrorCode  PetscDrawLGSetDimension(PetscDrawLG lg,PetscInt dim)
{
  PetscErrorCode ierr;
  PetscInt       i;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(lg,PETSC_DRAWLG_CLASSID,1);
  PetscValidLogicalCollectiveInt(lg,dim,2);
  if (lg->dim == dim) PetscFunctionReturn(0);

  ierr = PetscFree2(lg->x,lg->y);CHKERRQ(ierr);
  if (lg->legend) {
    for (i=0; i<lg->dim; i++) {
      ierr = PetscFree(lg->legend[i]);CHKERRQ(ierr);
    }
    ierr = PetscFree(lg->legend);CHKERRQ(ierr);
  }
  ierr    = PetscFree(lg->colors);CHKERRQ(ierr);
  lg->dim = dim;
  ierr    = PetscMalloc2(dim*CHUNCKSIZE,&lg->x,dim*CHUNCKSIZE,&lg->y);CHKERRQ(ierr);
  ierr    = PetscLogObjectMemory((PetscObject)lg,2*dim*CHUNCKSIZE*sizeof(PetscReal));CHKERRQ(ierr);
  lg->len = dim*CHUNCKSIZE;
  PetscFunctionReturn(0);
}
コード例 #22
0
ファイル: da.c プロジェクト: ZJLi2013/petsc
/*@
  DMDASetNonOverlappingRegion - Sets the indices of the nonoverlapping region of a subdomain DM.

  Collective on DA

  Input Parameter:
+ da  - The DMDA
. xs  - The start of the region in x
. ys  - The start of the region in y
. zs  - The start of the region in z
. xs  - The size of the region in x
. ys  - The size of the region in y
. zs  - The size of the region in z

  Level: intermediate

.keywords:  distributed array, degrees of freedom
.seealso: DMDAGetOffset(), DMDAVecGetArray()
@*/
PetscErrorCode  DMDASetNonOverlappingRegion(DM da, PetscInt xs, PetscInt ys, PetscInt zs, PetscInt xm, PetscInt ym, PetscInt zm)
{
  DM_DA          *dd = (DM_DA*)da->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(da,DM_CLASSID,1);
  PetscValidLogicalCollectiveInt(da,xs,2);
  PetscValidLogicalCollectiveInt(da,ys,3);
  PetscValidLogicalCollectiveInt(da,zs,4);
  PetscValidLogicalCollectiveInt(da,xm,5);
  PetscValidLogicalCollectiveInt(da,ym,6);
  PetscValidLogicalCollectiveInt(da,zm,7);
  dd->nonxs = xs;
  dd->nonys = ys;
  dd->nonzs = zs;
  dd->nonxm = xm;
  dd->nonym = ym;
  dd->nonzm = zm;

  PetscFunctionReturn(0);
}
コード例 #23
0
ファイル: mg.c プロジェクト: ziolai/petsc
/*@C
   PCMGSetLevels - Sets the number of levels to use with MG.
   Must be called before any other MG routine.

   Logically Collective on PC

   Input Parameters:
+  pc - the preconditioner context
.  levels - the number of levels
-  comms - optional communicators for each level; this is to allow solving the coarser problems
           on smaller sets of processors. Use NULL_OBJECT for default in Fortran

   Level: intermediate

   Notes:
     If the number of levels is one then the multigrid uses the -mg_levels prefix
  for setting the level options rather than the -mg_coarse prefix.

.keywords: MG, set, levels, multigrid

.seealso: PCMGSetType(), PCMGGetLevels()
@*/
PetscErrorCode  PCMGSetLevels(PC pc,PetscInt levels,MPI_Comm *comms)
{
  PetscErrorCode ierr;
  PC_MG          *mg        = (PC_MG*)pc->data;
  MPI_Comm       comm;
  PC_MG_Levels   **mglevels = mg->levels;
  PCMGType       mgtype     = mg->am;
  PetscInt       mgctype    = (PetscInt) PC_MG_CYCLE_V;
  PetscInt       i;
  PetscMPIInt    size;
  const char     *prefix;
  PC             ipc;
  PetscInt       n;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(pc,PC_CLASSID,1);
  PetscValidLogicalCollectiveInt(pc,levels,2);
  ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
  if (mg->nlevels == levels) PetscFunctionReturn(0);
  if (mglevels) {
    mgctype = mglevels[0]->cycles;
    /* changing the number of levels so free up the previous stuff */
    ierr = PCReset_MG(pc);CHKERRQ(ierr);
    n    = mglevels[0]->levels;
    for (i=0; i<n; i++) {
      if (mglevels[i]->smoothd != mglevels[i]->smoothu) {
        ierr = KSPDestroy(&mglevels[i]->smoothd);CHKERRQ(ierr);
      }
      ierr = KSPDestroy(&mglevels[i]->smoothu);CHKERRQ(ierr);
      ierr = PetscFree(mglevels[i]);CHKERRQ(ierr);
    }
    ierr = PetscFree(mg->levels);CHKERRQ(ierr);
  }

  mg->nlevels = levels;

  ierr = PetscMalloc1(levels,&mglevels);CHKERRQ(ierr);
  ierr = PetscLogObjectMemory((PetscObject)pc,levels*(sizeof(PC_MG*)));CHKERRQ(ierr);

  ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);

  mg->stageApply = 0;
  for (i=0; i<levels; i++) {
    ierr = PetscNewLog(pc,&mglevels[i]);CHKERRQ(ierr);

    mglevels[i]->level               = i;
    mglevels[i]->levels              = levels;
    mglevels[i]->cycles              = mgctype;
    mg->default_smoothu              = 2;
    mg->default_smoothd              = 2;
    mglevels[i]->eventsmoothsetup    = 0;
    mglevels[i]->eventsmoothsolve    = 0;
    mglevels[i]->eventresidual       = 0;
    mglevels[i]->eventinterprestrict = 0;

    if (comms) comm = comms[i];
    ierr = KSPCreate(comm,&mglevels[i]->smoothd);CHKERRQ(ierr);
    ierr = KSPSetErrorIfNotConverged(mglevels[i]->smoothd,pc->erroriffailure);CHKERRQ(ierr);
    ierr = PetscObjectIncrementTabLevel((PetscObject)mglevels[i]->smoothd,(PetscObject)pc,levels-i);CHKERRQ(ierr);
    ierr = KSPSetOptionsPrefix(mglevels[i]->smoothd,prefix);CHKERRQ(ierr);
    ierr = PetscObjectComposedDataSetInt((PetscObject) mglevels[i]->smoothd, PetscMGLevelId, mglevels[i]->level);CHKERRQ(ierr);
    if (i || levels == 1) {
      char tprefix[128];

      ierr = KSPSetType(mglevels[i]->smoothd,KSPCHEBYSHEV);CHKERRQ(ierr);
      ierr = KSPSetConvergenceTest(mglevels[i]->smoothd,KSPConvergedSkip,NULL,NULL);CHKERRQ(ierr);
      ierr = KSPSetNormType(mglevels[i]->smoothd,KSP_NORM_NONE);CHKERRQ(ierr);
      ierr = KSPGetPC(mglevels[i]->smoothd,&ipc);CHKERRQ(ierr);
      ierr = PCSetType(ipc,PCSOR);CHKERRQ(ierr);
      ierr = KSPSetTolerances(mglevels[i]->smoothd,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT, mg->default_smoothd);CHKERRQ(ierr);

      sprintf(tprefix,"mg_levels_%d_",(int)i);
      ierr = KSPAppendOptionsPrefix(mglevels[i]->smoothd,tprefix);CHKERRQ(ierr);
    } else {
      ierr = KSPAppendOptionsPrefix(mglevels[0]->smoothd,"mg_coarse_");CHKERRQ(ierr);

      /* coarse solve is (redundant) LU by default; set shifttype NONZERO to avoid annoying zero-pivot in LU preconditioner */
      ierr = KSPSetType(mglevels[0]->smoothd,KSPPREONLY);CHKERRQ(ierr);
      ierr = KSPGetPC(mglevels[0]->smoothd,&ipc);CHKERRQ(ierr);
      ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
      if (size > 1) {
        ierr = PCSetType(ipc,PCREDUNDANT);CHKERRQ(ierr);
      } else {
        ierr = PCSetType(ipc,PCLU);CHKERRQ(ierr);
      }
      ierr = PCFactorSetShiftType(ipc,MAT_SHIFT_INBLOCKS);CHKERRQ(ierr);
    }
    ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)mglevels[i]->smoothd);CHKERRQ(ierr);

    mglevels[i]->smoothu = mglevels[i]->smoothd;
    mg->rtol             = 0.0;
    mg->abstol           = 0.0;
    mg->dtol             = 0.0;
    mg->ttol             = 0.0;
    mg->cyclesperpcapply = 1;
  }
  mg->levels = mglevels;
  ierr = PCMGSetType(pc,mgtype);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #24
0
PetscErrorCode PCBDDCGraphSetUp(PCBDDCGraph graph, PetscInt custom_minimal_size, IS neumann_is, IS dirichlet_is, PetscInt n_ISForDofs, IS ISForDofs[], IS custom_primal_vertices)
{
  IS             subset,subset_n;
  MPI_Comm       comm;
  const PetscInt *is_indices;
  PetscInt       n_neigh,*neigh,*n_shared,**shared,*queue_global;
  PetscInt       i,j,k,s,total_counts,nodes_touched,is_size;
  PetscMPIInt    commsize;
  PetscBool      same_set,mirrors_found;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidLogicalCollectiveInt(graph->l2gmap,custom_minimal_size,2);
  if (neumann_is) {
    PetscValidHeaderSpecific(neumann_is,IS_CLASSID,3);
    PetscCheckSameComm(graph->l2gmap,1,neumann_is,3);
  }
  graph->has_dirichlet = PETSC_FALSE;
  if (dirichlet_is) {
    PetscValidHeaderSpecific(dirichlet_is,IS_CLASSID,4);
    PetscCheckSameComm(graph->l2gmap,1,dirichlet_is,4);
    graph->has_dirichlet = PETSC_TRUE;
  }
  PetscValidLogicalCollectiveInt(graph->l2gmap,n_ISForDofs,5);
  for (i=0;i<n_ISForDofs;i++) {
    PetscValidHeaderSpecific(ISForDofs[i],IS_CLASSID,6);
    PetscCheckSameComm(graph->l2gmap,1,ISForDofs[i],6);
  }
  if (custom_primal_vertices) {
    PetscValidHeaderSpecific(custom_primal_vertices,IS_CLASSID,6);
    PetscCheckSameComm(graph->l2gmap,1,custom_primal_vertices,7);
  }
  ierr = PetscObjectGetComm((PetscObject)(graph->l2gmap),&comm);CHKERRQ(ierr);
  ierr = MPI_Comm_size(comm,&commsize);CHKERRQ(ierr);

  /* custom_minimal_size */
  graph->custom_minimal_size = custom_minimal_size;
  /* get info l2gmap and allocate work vectors  */
  ierr = ISLocalToGlobalMappingGetInfo(graph->l2gmap,&n_neigh,&neigh,&n_shared,&shared);CHKERRQ(ierr);
  /* check if we have any local periodic nodes (periodic BCs) */
  mirrors_found = PETSC_FALSE;
  if (graph->nvtxs && n_neigh) {
    for (i=0; i<n_shared[0]; i++) graph->count[shared[0][i]] += 1;
    for (i=0; i<n_shared[0]; i++) {
      if (graph->count[shared[0][i]] > 1) {
        mirrors_found = PETSC_TRUE;
        break;
      }
    }
  }
  /* compute local mirrors (if any) */
  if (mirrors_found) {
    IS       to,from;
    PetscInt *local_indices,*global_indices;

    ierr = ISCreateStride(PETSC_COMM_SELF,graph->nvtxs,0,1,&to);CHKERRQ(ierr);
    ierr = ISLocalToGlobalMappingApplyIS(graph->l2gmap,to,&from);CHKERRQ(ierr);
    /* get arrays of local and global indices */
    ierr = PetscMalloc1(graph->nvtxs,&local_indices);CHKERRQ(ierr);
    ierr = ISGetIndices(to,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    ierr = PetscMemcpy(local_indices,is_indices,graph->nvtxs*sizeof(PetscInt));CHKERRQ(ierr);
    ierr = ISRestoreIndices(to,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    ierr = PetscMalloc1(graph->nvtxs,&global_indices);CHKERRQ(ierr);
    ierr = ISGetIndices(from,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    ierr = PetscMemcpy(global_indices,is_indices,graph->nvtxs*sizeof(PetscInt));CHKERRQ(ierr);
    ierr = ISRestoreIndices(from,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    /* allocate space for mirrors */
    ierr = PetscMalloc2(graph->nvtxs,&graph->mirrors,graph->nvtxs,&graph->mirrors_set);CHKERRQ(ierr);
    ierr = PetscMemzero(graph->mirrors,graph->nvtxs*sizeof(PetscInt));CHKERRQ(ierr);
    graph->mirrors_set[0] = 0;

    k=0;
    for (i=0;i<n_shared[0];i++) {
      j=shared[0][i];
      if (graph->count[j] > 1) {
        graph->mirrors[j]++;
        k++;
      }
    }
    /* allocate space for set of mirrors */
    ierr = PetscMalloc1(k,&graph->mirrors_set[0]);CHKERRQ(ierr);
    for (i=1;i<graph->nvtxs;i++)
      graph->mirrors_set[i]=graph->mirrors_set[i-1]+graph->mirrors[i-1];

    /* fill arrays */
    ierr = PetscMemzero(graph->mirrors,graph->nvtxs*sizeof(PetscInt));CHKERRQ(ierr);
    for (j=0;j<n_shared[0];j++) {
      i=shared[0][j];
      if (graph->count[i] > 1)
        graph->mirrors_set[i][graph->mirrors[i]++]=global_indices[i];
    }
    ierr = PetscSortIntWithArray(graph->nvtxs,global_indices,local_indices);CHKERRQ(ierr);
    for (i=0;i<graph->nvtxs;i++) {
      if (graph->mirrors[i] > 0) {
        ierr = PetscFindInt(graph->mirrors_set[i][0],graph->nvtxs,global_indices,&k);CHKERRQ(ierr);
        j = global_indices[k];
        while ( k > 0 && global_indices[k-1] == j) k--;
        for (j=0;j<graph->mirrors[i];j++) {
          graph->mirrors_set[i][j]=local_indices[k+j];
        }
        ierr = PetscSortInt(graph->mirrors[i],graph->mirrors_set[i]);CHKERRQ(ierr);
      }
    }
    ierr = PetscFree(local_indices);CHKERRQ(ierr);
    ierr = PetscFree(global_indices);CHKERRQ(ierr);
    ierr = ISDestroy(&to);CHKERRQ(ierr);
    ierr = ISDestroy(&from);CHKERRQ(ierr);
  }
  ierr = PetscMemzero(graph->count,graph->nvtxs*sizeof(*graph->count));CHKERRQ(ierr);

  /* Count total number of neigh per node */
  k = 0;
  for (i=1;i<n_neigh;i++) {
    k += n_shared[i];
    for (j=0;j<n_shared[i];j++) {
      graph->count[shared[i][j]] += 1;
    }
  }
  /* Allocate space for storing the set of neighbours for each node */
  if (graph->nvtxs) {
    ierr = PetscMalloc1(k,&graph->neighbours_set[0]);CHKERRQ(ierr);
  }
  for (i=1;i<graph->nvtxs;i++) { /* dont count myself */
    graph->neighbours_set[i]=graph->neighbours_set[i-1]+graph->count[i-1];
  }
  /* Get information for sharing subdomains */
  ierr = PetscMemzero(graph->count,graph->nvtxs*sizeof(*graph->count));CHKERRQ(ierr);
  for (i=1;i<n_neigh;i++) { /* dont count myself */
    s = n_shared[i];
    for (j=0;j<s;j++) {
      k = shared[i][j];
      graph->neighbours_set[k][graph->count[k]] = neigh[i];
      graph->count[k] += 1;
    }
  }
  /* sort set of sharing subdomains */
  for (i=0;i<graph->nvtxs;i++) {
    ierr = PetscSortRemoveDupsInt(&graph->count[i],graph->neighbours_set[i]);CHKERRQ(ierr);
  }
  /* free memory allocated by ISLocalToGlobalMappingGetInfo */
  ierr = ISLocalToGlobalMappingRestoreInfo(graph->l2gmap,&n_neigh,&neigh,&n_shared,&shared);CHKERRQ(ierr);

  /*
     Get info for dofs splitting
     User can specify just a subset; an additional field is considered as a complementary field
  */
  for (i=0;i<graph->nvtxs;i++) graph->which_dof[i] = n_ISForDofs; /* by default a dof belongs to the complement set */
  for (i=0;i<n_ISForDofs;i++) {
    ierr = ISGetLocalSize(ISForDofs[i],&is_size);CHKERRQ(ierr);
    ierr = ISGetIndices(ISForDofs[i],(const PetscInt**)&is_indices);CHKERRQ(ierr);
    for (j=0;j<is_size;j++) {
      if (is_indices[j] > -1 && is_indices[j] < graph->nvtxs) { /* out of bounds indices (if any) are skipped */
        graph->which_dof[is_indices[j]] = i;
      }
    }
    ierr = ISRestoreIndices(ISForDofs[i],(const PetscInt**)&is_indices);CHKERRQ(ierr);
  }

  /* Take into account Neumann nodes */
  if (neumann_is) {
    ierr = ISGetLocalSize(neumann_is,&is_size);CHKERRQ(ierr);
    ierr = ISGetIndices(neumann_is,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    for (i=0;i<is_size;i++) {
      if (is_indices[i] > -1 && is_indices[i] < graph->nvtxs) { /* out of bounds indices (if any) are skipped */
        graph->special_dof[is_indices[i]] = PCBDDCGRAPH_NEUMANN_MARK;
      }
    }
    ierr = ISRestoreIndices(neumann_is,(const PetscInt**)&is_indices);CHKERRQ(ierr);
  }
  /* Take into account Dirichlet nodes (they overwrite any neumann boundary mark previously set) */
  if (dirichlet_is) {
    ierr = ISGetLocalSize(dirichlet_is,&is_size);CHKERRQ(ierr);
    ierr = ISGetIndices(dirichlet_is,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    for (i=0;i<is_size;i++){
      if (is_indices[i] > -1 && is_indices[i] < graph->nvtxs) { /* out of bounds indices (if any) are skipped */
        if (commsize > graph->commsizelimit) { /* dirichlet nodes treated as internal */
          ierr = PetscBTSet(graph->touched,is_indices[i]);CHKERRQ(ierr);
          graph->subset[is_indices[i]] = 0;
        }
        graph->special_dof[is_indices[i]] = PCBDDCGRAPH_DIRICHLET_MARK;
      }
    }
    ierr = ISRestoreIndices(dirichlet_is,(const PetscInt**)&is_indices);CHKERRQ(ierr);
  }
  /* mark local periodic nodes (if any) and adapt CSR graph (if any) */
  if (graph->mirrors) {
    for (i=0;i<graph->nvtxs;i++)
      if (graph->mirrors[i])
        graph->special_dof[i] = PCBDDCGRAPH_LOCAL_PERIODIC_MARK;

    if (graph->xadj) {
      PetscInt *new_xadj,*new_adjncy;
      /* sort CSR graph */
      for (i=0;i<graph->nvtxs;i++)
        ierr = PetscSortInt(graph->xadj[i+1]-graph->xadj[i],&graph->adjncy[graph->xadj[i]]);CHKERRQ(ierr);

      /* adapt local CSR graph in case of local periodicity */
      k = 0;
      for (i=0;i<graph->nvtxs;i++)
        for (j=graph->xadj[i];j<graph->xadj[i+1];j++)
          k += graph->mirrors[graph->adjncy[j]];

      ierr = PetscMalloc1(graph->nvtxs+1,&new_xadj);CHKERRQ(ierr);
      ierr = PetscMalloc1(k+graph->xadj[graph->nvtxs],&new_adjncy);CHKERRQ(ierr);
      new_xadj[0] = 0;
      for (i=0;i<graph->nvtxs;i++) {
        k = graph->xadj[i+1]-graph->xadj[i];
        ierr = PetscMemcpy(&new_adjncy[new_xadj[i]],&graph->adjncy[graph->xadj[i]],k*sizeof(PetscInt));CHKERRQ(ierr);
        new_xadj[i+1] = new_xadj[i]+k;
        for (j=graph->xadj[i];j<graph->xadj[i+1];j++) {
          k = graph->mirrors[graph->adjncy[j]];
          ierr = PetscMemcpy(&new_adjncy[new_xadj[i+1]],graph->mirrors_set[graph->adjncy[j]],k*sizeof(PetscInt));CHKERRQ(ierr);
          new_xadj[i+1] += k;
        }
        k = new_xadj[i+1]-new_xadj[i];
        ierr = PetscSortRemoveDupsInt(&k,&new_adjncy[new_xadj[i]]);CHKERRQ(ierr);
        new_xadj[i+1] = new_xadj[i]+k;
      }
      /* set new CSR into graph */
      ierr = PetscFree(graph->xadj);CHKERRQ(ierr);
      ierr = PetscFree(graph->adjncy);CHKERRQ(ierr);
      graph->xadj = new_xadj;
      graph->adjncy = new_adjncy;
    }
  }

  /* mark special nodes (if any) -> each will become a single node equivalence class */
  if (custom_primal_vertices) {
    ierr = ISGetLocalSize(custom_primal_vertices,&is_size);CHKERRQ(ierr);
    ierr = ISGetIndices(custom_primal_vertices,(const PetscInt**)&is_indices);CHKERRQ(ierr);
    for (i=0,j=0;i<is_size;i++){
      if (is_indices[i] > -1 && is_indices[i] < graph->nvtxs  && graph->special_dof[is_indices[i]] != PCBDDCGRAPH_DIRICHLET_MARK) { /* out of bounds indices (if any) are skipped */
        graph->special_dof[is_indices[i]] = PCBDDCGRAPH_SPECIAL_MARK-j;
        j++;
      }
    }
    ierr = ISRestoreIndices(custom_primal_vertices,(const PetscInt**)&is_indices);CHKERRQ(ierr);
  }

  /* mark interior nodes (if commsize > graph->commsizelimit) as touched and belonging to partition number 0 */
  if (commsize > graph->commsizelimit) {
    for (i=0;i<graph->nvtxs;i++) {
      if (!graph->count[i]) {
        ierr = PetscBTSet(graph->touched,i);CHKERRQ(ierr);
        graph->subset[i] = 0;
      }
    }
  }

  /* init graph structure and compute default subsets */
  nodes_touched = 0;
  for (i=0;i<graph->nvtxs;i++) {
    if (PetscBTLookup(graph->touched,i)) {
      nodes_touched++;
    }
  }
  i = 0;
  graph->ncc = 0;
  total_counts = 0;

  /* allocated space for queues */
  if (commsize == graph->commsizelimit) {
    ierr = PetscMalloc2(graph->nvtxs+1,&graph->cptr,graph->nvtxs,&graph->queue);CHKERRQ(ierr);
  } else {
    PetscInt nused = graph->nvtxs - nodes_touched;
    ierr = PetscMalloc2(nused+1,&graph->cptr,nused,&graph->queue);CHKERRQ(ierr);
  }

  while (nodes_touched<graph->nvtxs) {
    /*  find first untouched node in local ordering */
    while (PetscBTLookup(graph->touched,i)) i++;
    ierr = PetscBTSet(graph->touched,i);CHKERRQ(ierr);
    graph->subset[i] = graph->ncc+1;
    graph->cptr[graph->ncc] = total_counts;
    graph->queue[total_counts] = i;
    total_counts++;
    nodes_touched++;
    /* now find all other nodes having the same set of sharing subdomains */
    for (j=i+1;j<graph->nvtxs;j++) {
      /* check for same number of sharing subdomains, dof number and same special mark */
      if (!PetscBTLookup(graph->touched,j) && graph->count[i] == graph->count[j] && graph->which_dof[i] == graph->which_dof[j] && graph->special_dof[i] == graph->special_dof[j]) {
        /* check for same set of sharing subdomains */
        same_set = PETSC_TRUE;
        for (k=0;k<graph->count[j];k++){
          if (graph->neighbours_set[i][k] != graph->neighbours_set[j][k]) {
            same_set = PETSC_FALSE;
          }
        }
        /* I found a friend of mine */
        if (same_set) {
          ierr = PetscBTSet(graph->touched,j);CHKERRQ(ierr);
          graph->subset[j] = graph->ncc+1;
          nodes_touched++;
          graph->queue[total_counts] = j;
          total_counts++;
        }
      }
    }
    graph->ncc++;
  }
  /* set default number of subsets (at this point no info on csr and/or local_subs has been taken into account, so n_subsets = ncc */
  graph->n_subsets = graph->ncc;
  ierr = PetscMalloc1(graph->n_subsets,&graph->subset_ncc);CHKERRQ(ierr);
  for (i=0;i<graph->n_subsets;i++) {
    graph->subset_ncc[i] = 1;
  }
  /* final pointer */
  graph->cptr[graph->ncc] = total_counts;

  /* For consistency reasons (among neighbours), I need to sort (by global ordering) each connected component */
  /* Get a reference node (min index in global ordering) for each subset for tagging messages */
  ierr = PetscMalloc1(graph->ncc,&graph->subset_ref_node);CHKERRQ(ierr);
  ierr = PetscMalloc1(graph->cptr[graph->ncc],&queue_global);CHKERRQ(ierr);
  ierr = ISLocalToGlobalMappingApply(graph->l2gmap,graph->cptr[graph->ncc],graph->queue,queue_global);CHKERRQ(ierr);
  for (j=0;j<graph->ncc;j++) {
    ierr = PetscSortIntWithArray(graph->cptr[j+1]-graph->cptr[j],&queue_global[graph->cptr[j]],&graph->queue[graph->cptr[j]]);CHKERRQ(ierr);
    graph->subset_ref_node[j] = graph->queue[graph->cptr[j]];
  }
  ierr = PetscFree(queue_global);CHKERRQ(ierr);
  graph->queue_sorted = PETSC_TRUE;

  /* save information on subsets (needed when analyzing the connected components) */
  if (graph->ncc) {
    ierr = PetscMalloc2(graph->ncc,&graph->subset_size,graph->ncc,&graph->subset_idxs);CHKERRQ(ierr);
    ierr = PetscMalloc1(graph->cptr[graph->ncc],&graph->subset_idxs[0]);CHKERRQ(ierr);
    ierr = PetscMemzero(graph->subset_idxs[0],graph->cptr[graph->ncc]*sizeof(PetscInt));CHKERRQ(ierr);
    for (j=1;j<graph->ncc;j++) {
      graph->subset_size[j-1] = graph->cptr[j] - graph->cptr[j-1];
      graph->subset_idxs[j] = graph->subset_idxs[j-1] + graph->subset_size[j-1];
    }
    graph->subset_size[graph->ncc-1] = graph->cptr[graph->ncc] - graph->cptr[graph->ncc-1];
    ierr = PetscMemcpy(graph->subset_idxs[0],graph->queue,graph->cptr[graph->ncc]*sizeof(PetscInt));CHKERRQ(ierr);
  }

  /* renumber reference nodes */
  ierr = ISCreateGeneral(PetscObjectComm((PetscObject)(graph->l2gmap)),graph->ncc,graph->subset_ref_node,PETSC_COPY_VALUES,&subset_n);CHKERRQ(ierr);
  ierr = ISLocalToGlobalMappingApplyIS(graph->l2gmap,subset_n,&subset);CHKERRQ(ierr);
  ierr = ISDestroy(&subset_n);CHKERRQ(ierr);
  ierr = ISRenumber(subset,NULL,NULL,&subset_n);CHKERRQ(ierr);
  ierr = ISDestroy(&subset);CHKERRQ(ierr);
  ierr = ISGetLocalSize(subset_n,&k);CHKERRQ(ierr);
  if (k != graph->ncc) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Invalid size of new subset! %D != %D",k,graph->ncc);
  ierr = ISGetIndices(subset_n,&is_indices);CHKERRQ(ierr);
  ierr = PetscMemcpy(graph->subset_ref_node,is_indices,graph->ncc*sizeof(PetscInt));CHKERRQ(ierr);
  ierr = ISRestoreIndices(subset_n,&is_indices);CHKERRQ(ierr);
  ierr = ISDestroy(&subset_n);CHKERRQ(ierr);

  /* free workspace */
  graph->setupcalled = PETSC_TRUE;
  PetscFunctionReturn(0);
}