MueLu  Version of the Day
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
MueLu_NullspacePresmoothFactory_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_NULLSPACEPRESMOOTHFACTORY_DEF_HPP
47 #define MUELU_NULLSPACEPRESMOOTHFACTORY_DEF_HPP
48 
49 #include <Xpetra_Matrix.hpp>
50 #include <Xpetra_MultiVector.hpp>
51 #include <Xpetra_MultiVectorFactory.hpp>
52 
54 #include "MueLu_Utilities.hpp"
55 
56 #include "MueLu_Monitor.hpp"
57 
58 namespace MueLu {
59 
60 template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
62  RCP<ParameterList> validParamList = rcp(new ParameterList());
63 
64  validParamList->set<RCP<const FactoryBase> >("A", Teuchos::null, "Generating factory for A");
65  validParamList->set<RCP<const FactoryBase> >("Nullspace", Teuchos::null, "Generating factory for the nonsmoothed nullspace");
66 
67  return validParamList;
68 }
69 
70 template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
72  Input(currentLevel, "Nullspace");
73 
74  if (currentLevel.GetLevelID() == 0)
75  Input(currentLevel, "A");
76 }
77 
78 template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
80  FactoryMonitor m(*this, "Nullspace presmooth factory", currentLevel);
81 
82  RCP<MultiVector> newB;
83  if (currentLevel.GetLevelID() == 0) {
84  RCP<Matrix> A = Get<RCP<Matrix> >(currentLevel, "A");
85  RCP<MultiVector> B = Get<RCP<MultiVector> >(currentLevel, "Nullspace");
86  newB = MultiVectorFactory::Build(B->getMap(), B->getNumVectors());
87 
89 
90  SC damping = 4. / 3;
91  damping /= Utilities::PowerMethod(*A, true, (LO)10, 1e-4);
92 
93  A->apply(*B, *newB, Teuchos::NO_TRANS);
94 
95  size_t numVec = newB->getNumVectors();
96  LO numElements = newB->getLocalLength();
97  for (size_t j = 0; j < numVec; j++) {
98  Teuchos::ArrayRCP<const SC> Bj = B->getData(j);
99  Teuchos::ArrayRCP<SC> newBj = newB->getDataNonConst(j);
100 
101  for (LO i = 0; i < numElements; i++)
102  newBj[i] = Bj[i] - damping * newBj[i] / D[i];
103  }
104  } else {
105  newB = Get<RCP<MultiVector> >(currentLevel, "Nullspace");
106  }
107 
108  // provide "Nullspace" variable on current level
109  Set(currentLevel, "Nullspace", newB);
110 
111 } // Build
112 
113 } // namespace MueLu
114 
115 #endif // MUELU_NULLSPACEPRESMOOTHFACTORY_DEF_HPP
void Build(Level &currentLevel) const
Build an object with this factory.
static Scalar PowerMethod(const Matrix &A, bool scaleByDiag=true, LocalOrdinal niters=10, Magnitude tolerance=1e-2, bool verbose=false, unsigned int seed=123)
Power method.
ParameterList & set(std::string const &name, T const &value, std::string const &docString="", RCP< const ParameterEntryValidator > const &validator=null)
Timer to be used in factories. Similar to Monitor but with additional timers.
RCP< const ParameterList > GetValidParameterList() const
Return a const parameter list of valid parameters that setParameterList() will accept.
LocalOrdinal LO
TEUCHOS_DEPRECATED RCP< T > rcp(T *p, Dealloc_T dealloc, bool owns_mem)
Class that holds all level-specific information.
Definition: MueLu_Level.hpp:99
static Teuchos::ArrayRCP< Scalar > GetMatrixDiagonal_arcp(const Matrix &A)
Extract Matrix Diagonal.
Scalar SC
void DeclareInput(Level &currentLevel) const
Specifies the data that this class needs, and the factories that generate that data.
int GetLevelID() const
Return level number.
Definition: MueLu_Level.cpp:76