Teuchos - Trilinos Tools Package Version of the Day
Teuchos_MatrixMarket_SymmetrizingAdder.hpp
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00041 
00042 #ifndef __Teuchos_MatrixMarket_SymmetrizingAdder_hpp
00043 #define __Teuchos_MatrixMarket_SymmetrizingAdder_hpp
00044 
00045 #include <Teuchos_as.hpp>
00046 #include <Teuchos_ScalarTraits.hpp>
00047 #include <string>
00048 
00049 
00050 namespace Teuchos {
00051   namespace MatrixMarket {
00052     // Anonymous namespace for helper functions for SymmetrizingAdder.
00053     namespace {
00054       bool isSkew (const std::string& symmType) {
00055         return symmType.size() >= 4 && symmType.substr(0,4) == "skew";
00056       }
00057 
00058       bool isConj (const std::string& symmType) {
00059         return std::string::npos != symmType.find ("hermitian");
00060       }
00061 
00062       bool needsSymmetrization (const std::string& symmType) {
00063         return symmType != "general";
00064       }
00065     } // namespace (anonymous)
00066 
00085     template<class AdderType>
00086     class SymmetrizingAdder {
00087     public:
00089       typedef typename AdderType::index_type index_type;
00091       typedef typename AdderType::value_type value_type;
00092 
00099       SymmetrizingAdder (const Teuchos::RCP<AdderType>& adder,
00100                          const std::string& symmType) :
00101         adder_ (adder),
00102         symmetrize_ (needsSymmetrization (symmType)),
00103         conjugate_ (isConj (symmType)),
00104         skew_ (isSkew (symmType))
00105       {}
00106 
00108       void
00109       operator() (const index_type i,
00110                   const index_type j,
00111                   const value_type& Aij)
00112       {
00113         AdderType& theAdder = *adder_;
00114 
00115         theAdder (i, j, Aij);
00116         if (symmetrize_ && i != j) {
00117           typedef Teuchos::ScalarTraits<value_type> STS;
00118           const value_type Aji = skew_ ?
00119             -(conjugate_ ? STS::conjugate(Aij) : Aij) :
00120             (conjugate_ ? STS::conjugate(Aij) : Aij);
00121           theAdder (j, i, Aji);
00122         }
00123       }
00124 
00128       Teuchos::RCP<AdderType> getAdder() const {
00129         return adder_;
00130       }
00131 
00132     private:
00134       Teuchos::RCP<AdderType> adder_;
00136       bool symmetrize_;
00138       bool conjugate_;
00140       bool skew_;
00141     };
00142 
00143   } // namespace MatrixMarket
00144 } // namespace Teuchos
00145 
00146 #endif // __Teuchos_MatrixMarket_SymmetrizingAdder_hpp
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