scalarproducts.hh

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/*
 * scalarproducts.hh
 *
 *  Created on: Sep 16, 2011
 *      Author: bzflubko
 */
 
#ifndef SCALARPRODUCTS_HH_
#define SCALARPRODUCTS_HH_
 
#include <cmath>
#include <dune/common/fvector.hh>
#include <dune/common/fmatrix.hh>
 
namespace Kaskade
{
  namespace {
 
 
    template <class Type>
    struct NormTraits{
      typedef typename Type::value_type return_type;
      typedef typename Type::const_iterator iterator;
    };
 
    template <class value_type, int rows>
    struct NormTraits<Dune::FieldVector<value_type,rows> >{
      typedef value_type return_type;
      typedef typename Dune::FieldVector<value_type,rows>::const_iterator iterator;
    };
 
    template <class value_type, int rows, int cols>
    struct NormTraits<Dune::FieldMatrix<value_type,rows,cols> >{
      typedef value_type return_type;
      typedef typename Dune::FieldMatrix<value_type,rows,cols>::const_iterator iterator;
    };
 
  } // end of anonymous namespace
  namespace LinAlg{
 
    struct EuclideanScalarProduct{
      template <class Type>
      typename NormTraits<Type>::return_type operator()(Type const& v1, Type const& v2) const
      {
        typename NormTraits<Type>::return_type result(0);
        typename NormTraits<Type>::iterator iend = v1.end(), it1 = v1.begin(), it2 = v2.begin();
        for(; it1 != iend; ++it1, ++it2)
          result += (*it1) * (*it2);
        return result;
      }
    };
 
    // forward declaration
    template <class> struct Norm;
 
    template <class ScalarProduct_>
    struct NormSquared{
      typedef ScalarProduct_ ScalarProduct;
      typedef Norm<ScalarProduct> AssociatedNorm;
 
      NormSquared(ScalarProduct const sp=ScalarProduct()) : scalarProduct(sp){}
 
      template <class Type>
      typename NormTraits<Type>::return_type operator()(Type const& type) const
      {
        return scalarProduct(type,type);
      }
 
    private:
      ScalarProduct const scalarProduct;
    };
 
    template <class ScalarProduct_>
    struct Norm{
      typedef ScalarProduct_ ScalarProduct;
      typedef NormSquared<ScalarProduct> AssociatedNormSquared;
 
      Norm(ScalarProduct const sp=ScalarProduct()) : normSquared(sp){}
 
      template <class Type>
      typename NormTraits<Type>::return_type operator()(Type const& type) const
      {
        return sqrt(normSquared(type));
      }
 
    private:
      NormSquared<ScalarProduct> normSquared;
    };
 
    typedef Norm<EuclideanScalarProduct> EuclideanNorm;
 
    typedef NormSquared<EuclideanScalarProduct> EuclideanNormSquared;
 
 
    struct InfinityNorm{
      template<class Type>
      typename NormTraits<Type>::return_type operator()(Type const& type) const
      {
        typename NormTraits<Type>::return_type result(0);
        typename NormTraits<Type>::iterator iend = type.end(), iter = type.begin();
        for(; iter != iend; ++iter) if(result < fabs(*iter)) result = fabs(*iter);
        return result;
      }
    };
 
 
    struct OneNorm{
      template<class Type>
      typename NormTraits<Type>::return_type operator()(Type const& type) const
      {
        typename NormTraits<Type>::return_type result(0);
        typename NormTraits<Type>::iterator iend = type.end(), iter = type.begin();
        for(; iter != iend; ++iter)
                result += fabs(*iter);
        return result;
      }
    };
 
  }
}
#endif /* SCALARPRODUCTS_HH_ */