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MueLu_BraessSarazinSmoother_def.hpp
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46 
47 #ifndef MUELU_BRAESSSARAZINSMOOTHER_DEF_HPP_
48 #define MUELU_BRAESSSARAZINSMOOTHER_DEF_HPP_
49 
50 #include <Teuchos_ArrayViewDecl.hpp>
51 #include <Teuchos_ScalarTraits.hpp>
52 
53 #include "MueLu_ConfigDefs.hpp"
54 
55 #include <Xpetra_Matrix.hpp>
56 #include <Xpetra_BlockedCrsMatrix.hpp>
57 #include <Xpetra_MultiVectorFactory.hpp>
58 #include <Xpetra_VectorFactory.hpp>
59 #include <Xpetra_ReorderedBlockedCrsMatrix.hpp>
60 
62 #include "MueLu_Level.hpp"
63 #include "MueLu_Utilities.hpp"
64 #include "MueLu_Monitor.hpp"
65 #include "MueLu_HierarchyUtils.hpp"
66 #include "MueLu_SmootherBase.hpp"
67 
68 #include "MueLu_FactoryManager.hpp"
69 
70 namespace MueLu {
71 
72  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
73  void BraessSarazinSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::AddFactoryManager(RCP<const FactoryManagerBase> FactManager, int pos) {
74  TEUCHOS_TEST_FOR_EXCEPTION(pos != 0, Exceptions::RuntimeError, "MueLu::BraessSarazinSmoother::AddFactoryManager: parameter \'pos\' must be zero! error.");
75  FactManager_ = FactManager;
76  }
77 
78  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
80  RCP<ParameterList> validParamList = rcp(new ParameterList());
81 
82  SC one = Teuchos::ScalarTraits<SC>::one();
83 
84  validParamList->set<RCP<const FactoryBase> >("A", Teuchos::null, "Generating factory of the matrix A");
85 
86  validParamList->set<bool>("lumping", false, "Use lumping to construct diag(A(0,0)), "
87  "i.e. use row sum of the abs values on the diagonal as approximation of A00 (and A00^{-1})");
88  validParamList->set<SC>("Damping factor", one, "Damping/Scaling factor in BraessSarazin (usually has to be chosen > 1, default = 1.0)");
89  validParamList->set<LO>("Sweeps", 1, "Number of BraessSarazin sweeps (default = 1)");
90  validParamList->set<bool>("q2q1 mode", false, "Run in the mode matching Q2Q1 matlab code");
91 
92  return validParamList;
93  }
94 
95  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
97  this->Input(currentLevel, "A");
98 
99  TEUCHOS_TEST_FOR_EXCEPTION(FactManager_.is_null(), Exceptions::RuntimeError,
100  "MueLu::BraessSarazinSmoother::DeclareInput: FactManager_ must not be null! "
101  "Introduce a FactoryManager for the SchurComplement equation.");
102 
103  // carefully call DeclareInput after switching to internal FactoryManager
104  {
105  SetFactoryManager currentSFM(rcpFromRef(currentLevel), FactManager_);
106 
107  // request "Smoother" for current subblock row.
108  currentLevel.DeclareInput("PreSmoother", FactManager_->GetFactory("Smoother").get());
109 
110  // request Schur matrix just in case
111  currentLevel.DeclareInput("A", FactManager_->GetFactory("A").get());
112  }
113  }
114 
115  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
117  FactoryMonitor m(*this, "Setup Smoother", currentLevel);
118 
119  if (SmootherPrototype::IsSetup() == true)
120  this->GetOStream(Warnings0) << "MueLu::BreaessSarazinSmoother::Setup(): Setup() has already been called";
121 
122  // Extract blocked operator A from current level
123  A_ = Factory::Get<RCP<Matrix> > (currentLevel, "A");
124  RCP<BlockedCrsMatrix> bA = rcp_dynamic_cast<BlockedCrsMatrix>(A_);
125  TEUCHOS_TEST_FOR_EXCEPTION(bA.is_null(), Exceptions::BadCast,
126  "MueLu::BraessSarazinSmoother::Setup: input matrix A is not of type BlockedCrsMatrix! error.");
127 
128  // Store map extractors
129  rangeMapExtractor_ = bA->getRangeMapExtractor();
130  domainMapExtractor_ = bA->getDomainMapExtractor();
131 
132  // Store the blocks in local member variables
133  A00_ = bA->getMatrix(0,0);
134  A01_ = bA->getMatrix(0,1);
135  A10_ = bA->getMatrix(1,0);
136  A11_ = bA->getMatrix(1,1);
137 
138  const ParameterList& pL = Factory::GetParameterList();
139  SC omega = pL.get<SC>("Damping factor");
140 
141  // Create the inverse of the diagonal of F
142  // TODO add safety check for zeros on diagonal of F!
143  RCP<Vector> diagFVector = VectorFactory::Build(A00_->getRowMap());
144  if (pL.get<bool>("lumping") == false) {
145  A00_->getLocalDiagCopy(*diagFVector); // extract diagonal of F
146  } else {
147  diagFVector = Utilities::GetLumpedMatrixDiagonal(*A00_);
148  }
149  diagFVector->scale(omega);
150  D_ = Utilities::GetInverse(diagFVector);
151 
152  // check whether D_ is a blocked vector with only 1 block
153  RCP<BlockedVector> bD = Teuchos::rcp_dynamic_cast<BlockedVector>(D_);
154  if(bD.is_null() == false && bD->getBlockedMap()->getNumMaps() == 1) {
155  RCP<Vector> nestedVec = bD->getMultiVector(0,bD->getBlockedMap()->getThyraMode())->getVectorNonConst(0);
156  D_.swap(nestedVec);
157  }
158 
159  // Set the Smoother
160  // carefully switch to the SubFactoryManagers (defined by the users)
161  {
162  SetFactoryManager currentSFM(rcpFromRef(currentLevel), FactManager_);
163  smoo_ = currentLevel.Get<RCP<SmootherBase> >("PreSmoother", FactManager_->GetFactory("Smoother").get());
164  S_ = currentLevel.Get<RCP<Matrix> > ("A", FactManager_->GetFactory("A").get());
165  }
166 
168  }
169 
170  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
171  void BraessSarazinSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Apply(MultiVector& X, const MultiVector& B, bool InitialGuessIsZero) const {
172  TEUCHOS_TEST_FOR_EXCEPTION(SmootherPrototype::IsSetup() == false, Exceptions::RuntimeError,
173  "MueLu::BraessSarazinSmoother::Apply(): Setup() has not been called");
174 
175  RCP<MultiVector> rcpX = rcpFromRef(X);
176  RCP<const MultiVector> rcpB = rcpFromRef(B);
177 
178  // make sure that both rcpX and rcpB are BlockedMultiVector objects
179  bool bCopyResultX = false;
180  RCP<BlockedCrsMatrix> bA = Teuchos::rcp_dynamic_cast<BlockedCrsMatrix>(A_);
181  MUELU_TEST_FOR_EXCEPTION(bA.is_null() == true, Exceptions::RuntimeError, "MueLu::BlockedGaussSeidelSmoother::Apply(): A_ must be a BlockedCrsMatrix");
182  RCP<BlockedMultiVector> bX = Teuchos::rcp_dynamic_cast<BlockedMultiVector>(rcpX);
183  RCP<const BlockedMultiVector> bB = Teuchos::rcp_dynamic_cast<const BlockedMultiVector>(rcpB);
184 
185  if(bX.is_null() == true) {
186  RCP<MultiVector> test = Teuchos::rcp(new BlockedMultiVector(bA->getBlockedDomainMap(),rcpX));
187  rcpX.swap(test);
188  bCopyResultX = true;
189  }
190 
191  if(bB.is_null() == true) {
192  RCP<const MultiVector> test = Teuchos::rcp(new BlockedMultiVector(bA->getBlockedRangeMap(),rcpB));
193  rcpB.swap(test);
194  }
195 
196  // we now can guarantee that X and B are blocked multi vectors
197  bX = Teuchos::rcp_dynamic_cast<BlockedMultiVector>(rcpX);
198  bB = Teuchos::rcp_dynamic_cast<const BlockedMultiVector>(rcpB);
199 
200  // check the type of operator
201  RCP<Xpetra::ReorderedBlockedCrsMatrix<Scalar,LocalOrdinal,GlobalOrdinal,Node> > rbA = Teuchos::rcp_dynamic_cast<Xpetra::ReorderedBlockedCrsMatrix<Scalar,LocalOrdinal,GlobalOrdinal,Node> >(bA);
202  if(rbA.is_null() == false) {
203  // A is a ReorderedBlockedCrsMatrix
204  Teuchos::RCP<const Xpetra::BlockReorderManager > brm = rbA->getBlockReorderManager();
205 
206  // check type of X vector
207  if(bX->getBlockedMap()->getNumMaps() != bA->getDomainMapExtractor()->NumMaps()) {
208  // X is a blocked multi vector but incompatible to the reordered blocked operator A
209  Teuchos::RCP<MultiVector> test =
210  buildReorderedBlockedMultiVector(brm, bX);
211  rcpX.swap(test);
212  }
213  if(bB->getBlockedMap()->getNumMaps() != bA->getRangeMapExtractor()->NumMaps()) {
214  // B is a blocked multi vector but incompatible to the reordered blocked operator A
215  Teuchos::RCP<const MultiVector> test =
216  buildReorderedBlockedMultiVector(brm, bB);
217  rcpB.swap(test);
218  }
219  }
220 
221  // use the GIDs of the sub blocks
222  // This is valid as the subblocks actually represent the GIDs (either Thyra, Xpetra or pseudo Xpetra)
223 
224  bool bRangeThyraMode = rangeMapExtractor_->getThyraMode();
225  bool bDomainThyraMode = domainMapExtractor_->getThyraMode();
226 
227  RCP<MultiVector> deltaX = MultiVectorFactory::Build(rcpX->getMap(), rcpX->getNumVectors());
228  RCP<BlockedMultiVector> bdeltaX = Teuchos::rcp_dynamic_cast<BlockedMultiVector>(deltaX);
229  RCP<MultiVector> deltaX0 = bdeltaX->getMultiVector(0,bDomainThyraMode);
230  RCP<MultiVector> deltaX1 = bdeltaX->getMultiVector(1,bDomainThyraMode);
231 
232  RCP<MultiVector> Rtmp = rangeMapExtractor_->getVector(1, rcpB->getNumVectors(), bRangeThyraMode);
233 
234 
235  typedef Teuchos::ScalarTraits<SC> STS;
236  SC one = STS::one(), zero = STS::zero();
237 
238  // extract parameters from internal parameter list
239  const ParameterList& pL = Factory::GetParameterList();
240  LO nSweeps = pL.get<LO>("Sweeps");
241 
242  RCP<MultiVector> R;// = MultiVectorFactory::Build(rcpB->getMap(), rcpB->getNumVectors());;
243  if (InitialGuessIsZero) {
244  R = MultiVectorFactory::Build(rcpB->getMap(), rcpB->getNumVectors());
245  R->update(one, *rcpB, zero);
246  } else {
247  R = Utilities::Residual(*A_, *rcpX, *rcpB);
248  }
249 
250  // extract diagonal of Schur complement operator
251  RCP<Vector> diagSVector = VectorFactory::Build(S_->getRowMap());
252  S_->getLocalDiagCopy(*diagSVector);
253 
254  for (LO run = 0; run < nSweeps; ++run) {
255  // Extract corresponding subvectors from X and R
256  // Automatically detect whether we use Thyra or Xpetra GIDs
257  // The GIDs should be always compatible with the GIDs of A00, A01, etc...
258  RCP<MultiVector> R0 = rangeMapExtractor_ ->ExtractVector(R, 0, bRangeThyraMode);
259  RCP<MultiVector> R1 = rangeMapExtractor_ ->ExtractVector(R, 1, bRangeThyraMode);
260 
261  // Calculate Rtmp = R1 - D * deltaX0 (equation 8.14)
262  deltaX0->putScalar(zero);
263  deltaX0->elementWiseMultiply(one, *D_, *R0, zero); // deltaX0 = D * R0 (equation 8.13)
264  A10_->apply(*deltaX0, *Rtmp); // Rtmp = A10*D*deltaX0 (intermediate step)
265  Rtmp->update(one, *R1, -one); // Rtmp = R1 - A10*D*deltaX0
266 
267  if (!pL.get<bool>("q2q1 mode")) {
268  deltaX1->putScalar(zero);
269  } else {
270  // special code for q2q1
271  if(Teuchos::rcp_dynamic_cast<BlockedVector>(diagSVector) == Teuchos::null) {
272  ArrayRCP<SC> Sdiag = diagSVector->getDataNonConst(0);
273  ArrayRCP<SC> deltaX1data = deltaX1->getDataNonConst(0);
274  ArrayRCP<SC> Rtmpdata = Rtmp->getDataNonConst(0);
275  for (GO row = 0; row < deltaX1data.size(); row++)
276  deltaX1data[row] = Teuchos::as<SC>(1.1)*Rtmpdata[row] / Sdiag[row];
277  } else {
278  TEUCHOS_TEST_FOR_EXCEPTION(true,MueLu::Exceptions::RuntimeError,"MueLu::BraessSarazinSmoother: q2q1 mode only supported for non-blocked operators.")
279  }
280  }
281 
282  smoo_->Apply(*deltaX1,*Rtmp);
283 
284  // Compute deltaX0
285  deltaX0->putScalar(zero); // just for safety
286  A01_->apply(*deltaX1, *deltaX0); // deltaX0 = A01*deltaX1
287  deltaX0->update(one, *R0, -one); // deltaX0 = R0 - A01*deltaX1
288  R0.swap(deltaX0);
289  deltaX0->elementWiseMultiply(one, *D_, *R0, zero); // deltaX0 = D*(R0 - A01*deltaX1)
290 
291  RCP<MultiVector> X0 = domainMapExtractor_->ExtractVector(rcpX, 0, bDomainThyraMode);
292  RCP<MultiVector> X1 = domainMapExtractor_->ExtractVector(rcpX, 1, bDomainThyraMode);
293 
294  // Update solution
295  X0->update(one, *deltaX0, one);
296  X1->update(one, *deltaX1, one);
297 
298  domainMapExtractor_->InsertVector(X0, 0, rcpX, bDomainThyraMode);
299  domainMapExtractor_->InsertVector(X1, 1, rcpX, bDomainThyraMode);
300 
301  if (run < nSweeps-1) {
302  R = Utilities::Residual(*A_, *rcpX, *rcpB);
303  }
304 
305  }
306 
307  if (bCopyResultX == true) {
308  RCP<MultiVector> Xmerged = bX->Merge();
309  X.update(one, *Xmerged, zero);
310  }
311 
312  }
313 
314  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
315  RCP<MueLu::SmootherPrototype<Scalar, LocalOrdinal, GlobalOrdinal, Node> >
317  return rcp (new BraessSarazinSmoother (*this));
318  }
319 
320  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
322  description () const {
323  std::ostringstream out;
325  out << "{type = " << type_ << "}";
326  return out.str();
327  }
328 
329  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
330  void BraessSarazinSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::print(Teuchos::FancyOStream &out, const VerbLevel verbLevel) const {
332 
333  if (verbLevel & Parameters0) {
334  out0 << "Prec. type: " << type_ << /*" Sweeps: " << nSweeps_ << " damping: " << omega_ <<*/ std::endl;
335  }
336 
337  if (verbLevel & Debug) {
338  out0 << "IsSetup: " << Teuchos::toString(SmootherPrototype::IsSetup()) << std::endl;
339  }
340  }
341 
342  template <class Scalar,class LocalOrdinal, class GlobalOrdinal, class Node>
344  // FIXME: This is a placeholder
345  return Teuchos::OrdinalTraits<size_t>::invalid();
346  }
347 
348 } // namespace MueLu
349 
350 #endif /* MUELU_BRAESSSARAZINSMOOTHER_DEF_HPP_ */
Important warning messages (one line)
Exception indicating invalid cast attempted.
RCP< SmootherPrototype > Copy() const
BraessSarazin smoother for 2x2 block matrices.
std::string toString(const T &what)
Little helper function to convert non-string types to strings.
bool IsSetup() const
Get the state of a smoother prototype.
Timer to be used in factories. Similar to Monitor but with additional timers.
Print additional debugging information.
Namespace for MueLu classes and methods.
static Teuchos::RCP< Xpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > > GetLumpedMatrixDiagonal(Xpetra::Matrix< Scalar, LocalOrdinal, GlobalOrdinal, Node > const &A, const bool doReciprocal=false, Magnitude tol=Teuchos::ScalarTraits< Scalar >::eps() *100, Scalar tolReplacement=Teuchos::ScalarTraits< Scalar >::zero(), const bool replaceSingleEntryRowWithZero=false)
std::string description() const
Return a simple one-line description of this object.
static RCP< Xpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > > Residual(const Xpetra::Operator< Scalar, LocalOrdinal, GlobalOrdinal, Node > &Op, const Xpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &X, const Xpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &RHS)
Class that holds all level-specific information.
Definition: MueLu_Level.hpp:99
void Apply(MultiVector &X, const MultiVector &B, bool InitialGuessIsZero=false) const
Apply the Braess Sarazin smoother.
virtual const Teuchos::ParameterList & GetParameterList() const
void print(Teuchos::FancyOStream &out, const VerbLevel verbLevel=Default) const
Print the object with some verbosity level to an FancyOStream object.
#define MUELU_DESCRIBE
Helper macro for implementing Describable::describe() for BaseClass objects.
Print class parameters.
static Teuchos::RCP< Xpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > > GetInverse(Teuchos::RCP< const Xpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > > v, Magnitude tol=Teuchos::ScalarTraits< Scalar >::eps() *100, Scalar tolReplacement=Teuchos::ScalarTraits< Scalar >::zero())
void AddFactoryManager(RCP< const FactoryManagerBase > FactManager, int pos=0)
Add a factory manager for BraessSarazin internal SchurComplement handling.
void DeclareInput(Level &currentLevel) const
Input.
void Setup(Level &currentLevel)
Setup routine.
size_t getNodeSmootherComplexity() const
Get a rough estimate of cost per iteration.
Exception throws to report errors in the internal logical of the program.
#define MUELU_TEST_FOR_EXCEPTION(throw_exception_test, Exception, msg)
An exception safe way to call the method &#39;Level::SetFactoryManager()&#39;.
void DeclareInput(const std::string &ename, const FactoryBase *factory, const FactoryBase *requestedBy=NoFactory::get())
Callback from FactoryBase::CallDeclareInput() and FactoryBase::DeclareInput()
virtual std::string description() const
Return a simple one-line description of this object.
RCP< const ParameterList > GetValidParameterList() const
Input.