MueLu  Version of the Day
MueLu_ThresholdAFilterFactory_def.hpp
Go to the documentation of this file.
1 // @HEADER
2 //
3 // ***********************************************************************
4 //
5 // MueLu: A package for multigrid based preconditioning
6 // Copyright 2012 Sandia Corporation
7 //
8 // Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
9 // the U.S. Government retains certain rights in this software.
10 //
11 // Redistribution and use in source and binary forms, with or without
12 // modification, are permitted provided that the following conditions are
13 // met:
14 //
15 // 1. Redistributions of source code must retain the above copyright
16 // notice, this list of conditions and the following disclaimer.
17 //
18 // 2. Redistributions in binary form must reproduce the above copyright
19 // notice, this list of conditions and the following disclaimer in the
20 // documentation and/or other materials provided with the distribution.
21 //
22 // 3. Neither the name of the Corporation nor the names of the
23 // contributors may be used to endorse or promote products derived from
24 // this software without specific prior written permission.
25 //
26 // THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
27 // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
30 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 //
38 // Questions? Contact
39 // Jonathan Hu (jhu@sandia.gov)
40 // Andrey Prokopenko (aprokop@sandia.gov)
41 // Ray Tuminaro (rstumin@sandia.gov)
42 //
43 // ***********************************************************************
44 //
45 // @HEADER
46 #ifndef MUELU_THRESHOLDAFILTERFACTORY_DEF_HPP
47 #define MUELU_THRESHOLDAFILTERFACTORY_DEF_HPP
48 
49 #include <Xpetra_Matrix.hpp>
50 #include <Xpetra_CrsMatrixWrap.hpp>
51 
53 
54 #include "MueLu_Level.hpp"
55 #include "MueLu_Monitor.hpp"
56 
57 namespace MueLu {
58 
59  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
61  : varName_(ename), threshold_(threshold)
62  { }
63 
64  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
66 
67  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
69  Input(currentLevel, varName_);
70  }
71 
72  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
74  Build (Level & currentLevel) const
75  {
76  FactoryMonitor m (*this, "A filter (thresholding)", currentLevel);
77 
78  typedef Xpetra::Matrix<Scalar, LocalOrdinal, GlobalOrdinal, Node> OMatrix; //TODO
79  typedef Xpetra::CrsMatrixWrap<Scalar, LocalOrdinal, GlobalOrdinal, Node> CrsOMatrix; //TODO
80 
81  RCP<OMatrix> Ain = Get< RCP<OMatrix> >(currentLevel, varName_);
82 
83  // create new empty Matrix
84  RCP<CrsOMatrix> Aout = rcp(new CrsOMatrix(Ain->getRowMap(),Ain->getGlobalMaxNumRowEntries(),Xpetra::StaticProfile)); //FIXME
85 
86  // loop over local rows
87  for(size_t row=0; row<Ain->getNodeNumRows(); row++)
88  {
89  size_t nnz = Ain->getNumEntriesInLocalRow(row);
90 
91  Teuchos::ArrayView<const LocalOrdinal> indices;
92  Teuchos::ArrayView<const Scalar> vals;
93  Ain->getLocalRowView(row, indices, vals);
94 
95  TEUCHOS_TEST_FOR_EXCEPTION(Teuchos::as<size_t>(indices.size()) != nnz, Exceptions::RuntimeError, "MueLu::ThresholdAFilterFactory::Build: number of nonzeros not equal to number of indices? Error.");
96 
97  Teuchos::ArrayRCP<GlobalOrdinal> indout(indices.size(),Teuchos::ScalarTraits<GlobalOrdinal>::zero());
98  Teuchos::ArrayRCP<Scalar> valout(indices.size(),Teuchos::ScalarTraits<Scalar>::zero());
99  size_t nNonzeros = 0;
100  for(size_t i=0; i<(size_t)indices.size(); i++) {
101  if(Teuchos::ScalarTraits<Scalar>::magnitude(vals[i]) > Teuchos::ScalarTraits<Scalar>::magnitude(threshold_) || indices[i]==(LocalOrdinal)row) {
102  indout[nNonzeros] = Ain->getColMap()->getGlobalElement(indices[i]); // LID -> GID (column)
103  valout[nNonzeros] = vals[i];
104  nNonzeros++;
105  }
106  }
107 
108  indout.resize(nNonzeros);
109  valout.resize(nNonzeros);
110 
111  Aout->insertGlobalValues(Ain->getRowMap()->getGlobalElement(row), indout.view(0,indout.size()), valout.view(0,valout.size()));
112  }
113 
114  Aout->fillComplete(Ain->getDomainMap(), Ain->getRangeMap());
115 
116  GetOStream(Statistics0) << "Nonzeros in " << varName_ << "(input): " << Ain->getGlobalNumEntries() << ", Nonzeros after filtering " << varName_ << " (parameter: " << threshold_ << "): " << Aout->getGlobalNumEntries() << std::endl;
117 
118  currentLevel.Set(varName_, Teuchos::rcp_dynamic_cast<OMatrix>(Aout), this);
119  }
120 
121 } // namespace MueLu
122 
123 #endif // MUELU_THRESHOLDAFILTERFACTORY_DEF_HPP
void DeclareInput(Level &currentLevel) const
Input.
Timer to be used in factories. Similar to Monitor but with additional timers.
Namespace for MueLu classes and methods.
Print statistics that do not involve significant additional computation.
Class that holds all level-specific information.
Definition: MueLu_Level.hpp:99
std::string varName_
name of input and output variable
ThresholdAFilterFactory(const std::string &ename, const Scalar threshold)
Constructor.
Teuchos::FancyOStream & GetOStream(MsgType type, int thisProcRankOnly=0) const
Get an output stream for outputting the input message type.
void Build(Level &currentLevel) const
Build an object with this factory.
Exception throws to report errors in the internal logical of the program.
void Input(Level &level, const std::string &varName) const