Commit 5b4326e3 authored by Patrick Jaap's avatar Patrick Jaap

Implementation of symmetric matrices

parent 23b1e546
Pipeline #16231 passed with stage
in 89 minutes and 51 seconds
#ifndef DUNE_FUFEM_SYMMETRICMATRIX_HH
#define DUNE_FUFEM_SYMMETRICMATRIX_HH
#include <dune/common/fvector.hh>
namespace Dune {
/** \brief A class implementing a symmetric matrix with compile-time size
*
* A \f$ dim\times dim \f$ matrix is stored internally as a <tt>Dune::FieldVector<double, dim*(dim+1)/2></tt>
* The components are assumed to be \f$ [ E(1,1),\ E(2,1),\ E(2,2),\ E(3,1),\ E(3,2),\ E(3,3) ]\f$
* and analogous for other dimensions
* \tparam dim number of lines/columns of the matrix
*/
template <class T, int N>
class SymmetricMatrix
{
public:
/** \brief The type used for scalars
*/
typedef T field_type;
/** \brief Default constructor, creates uninitialized matrix
*/
SymmetricMatrix()
{}
/** \brief Construct from raw memory */
template <class Iterator>
SymmetricMatrix(Iterator it)
{
for (size_t i=0; i<data_.size(); ++i, ++it)
data_[i] = *it;
}
SymmetricMatrix<T,N>& operator=(const T& s)
{
data_ = s;
return *this;
}
SymmetricMatrix<T,N>& operator*=(const T& s)
{
data_ *= s;
return *this;
}
/** \brief Matrix style random read/write access to components
* \param i line index
* \param j column index
* \note You need to know what you are doing: You can only access the lower
* left triangular submatrix using this methods. It requires i>=j.
*/
T& operator() (int i, int j)
{
if( i >= j )
return data_[i*(i+1)/2+j];
else
return data_[j*(j+1)/2+i];
}
/** \brief Matrix style random read access to components
* \param i line index
* \param j column index
* \note You need to know what you are doing: You can only access the lower
* left triangular submatrix using this methods. It requires i>=j.
*/
const T& operator() (int i, int j) const
{
if( i >= j )
return data_[i*(i+1)/2+j];
else
return data_[j*(j+1)/2+i];
}
T energyScalarProduct (const FieldVector<T,N>& v1, const FieldVector<T,N>& v2) const
{
T result = 0;
for (size_t i=0; i<N; i++)
for (size_t j=0; j<=i; j++)
result += (1-0.5*(i==j)) * operator()(i,j) * (v1[i] * v2[j] + v1[j] * v2[i]);
return result;
}
void axpy(const T& a, const SymmetricMatrix<T,N>& other)
{
data_.axpy(a,other.data_);
}
Dune::FieldVector<T,N*(N+1)/2> data() const
{
return data_;
}
Dune::FieldVector<T,N*(N+1)/2>& data()
{
return data_;
}
private:
Dune::FieldVector<T,N*(N+1)/2> data_;
};
}
#endif
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