rannacherturekbasis.hh

// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
#ifndef DUNE_FUNCTIONS_FUNCTIONSPACEBASES_RANNACHERTUREKBASIS_HH
#define DUNE_FUNCTIONS_FUNCTIONSPACEBASES_RANNACHERTUREKBASIS_HH
 
#include <dune/common/exceptions.hh>
 
#include <dune/localfunctions/rannacherturek.hh>
 
#include <dune/typetree/leafnode.hh>
 
#include <dune/functions/functionspacebases/nodes.hh>
#include <dune/functions/functionspacebases/defaultglobalbasis.hh>
#include <dune/functions/functionspacebases/flatmultiindex.hh>
 
 
namespace Dune {
namespace Functions {
 
// *****************************************************************************
// This is the reusable part of the basis. It contains
//
//   RannacherTurekPreBasis
//   RannacherTurekNodeIndexSet
//   RannacherTurekNode
//
// The pre-basis allows to create the others and is the owner of possible shared
// state. These three components do _not_ depend on the global basis or index
// set and can be used without a global basis.
// *****************************************************************************
 
template<typename GV>
class RannacherTurekNode;
 
template<typename GV, class MI>
class RannacherTurekNodeIndexSet;
 
template<typename GV, class MI>
class RannacherTurekPreBasis;
 
template<typename GV, class MI>
class RannacherTurekPreBasis
{
  static const int dim = GV::dimension;
 
public:
 
  using GridView = GV;
 
  using size_type = std::size_t;
 
  using Node = RannacherTurekNode<GV>;
 
  using IndexSet = RannacherTurekNodeIndexSet<GV, MI>;
 
  using MultiIndex = MI;
 
  using SizePrefix = Dune::ReservedVector<size_type, 1>;
 
  RannacherTurekPreBasis(const GridView& gv) :
    gridView_(gv)
  {}
 
  void initializeIndices()
  {}
 
  const GridView& gridView() const
  {
    return gridView_;
  }
 
  void update (const GridView& gv)
  {
    gridView_ = gv;
  }
 
  Node makeNode() const
  {
    return Node{};
  }
 
  IndexSet makeIndexSet() const
  {
    return IndexSet{*this};
  }
 
  size_type size() const
  {
    return (size_type)(gridView_.size(1));
  }
 
  size_type size(const SizePrefix prefix) const
  {
    assert(prefix.size() == 0 || prefix.size() == 1);
    return (prefix.size() == 0) ? size() : 0;
  }
 
  size_type dimension() const
  {
    return size();
  }
 
  size_type maxNodeSize() const
  {
    return 2*GV::dimension;
  }
 
protected:
  GridView gridView_;
};
 
 
 
template<typename GV>
class RannacherTurekNode :
  public LeafBasisNode
{
  static const int dim = GV::dimension;
  static const int maxSize = 2*dim;
 
public:
 
  using size_type = std::size_t;
  using Element = typename GV::template Codim<0>::Entity;
  using FiniteElement = RannacherTurekLocalFiniteElement<typename GV::ctype, double, dim>;
 
  RannacherTurekNode() :
    finiteElement_(),
    element_(nullptr)
  {}
 
  const Element& element() const
  {
    return *element_;
  }
 
  const FiniteElement& finiteElement() const
  {
    return finiteElement_;
  }
 
  void bind(const Element& e)
  {
    element_ = &e;
#ifndef NDEBUG
    if (e.type() != finiteElement_.type())
      DUNE_THROW(Dune::Exception,
                 "Rannacher-Turek elements do not exist for elements of type " << e.type());
#endif
    this->setSize(finiteElement_.size());
  }
 
protected:
 
  const FiniteElement finiteElement_;
  const Element* element_;
};
 
 
 
template<typename GV, class MI>
class RannacherTurekNodeIndexSet
{
  enum {dim = GV::dimension};
 
public:
 
  using size_type = std::size_t;
 
  using MultiIndex = MI;
 
  using PreBasis = RannacherTurekPreBasis<GV, MI>;
 
  using Node = RannacherTurekNode<GV>;
 
  RannacherTurekNodeIndexSet(const PreBasis& preBasis) :
    preBasis_(&preBasis)
  {}
 
  void bind(const Node& node)
  {
    node_ = &node;
  }
 
  void unbind()
  {
    node_ = nullptr;
  }
 
  size_type size() const
  {
    return (size_type)(node_->finiteElement().size());
  }
 
  template<typename It>
  It indices(It it) const
  {
    for (size_type i = 0, end = size() ; i < end ; ++i, ++it)
      {
        Dune::LocalKey localKey = node_->finiteElement().localCoefficients().localKey(i);
        const auto& gridIndexSet = preBasis_->gridView().indexSet();
        const auto& element = node_->element();
 
        *it = {{ (size_type)(gridIndexSet.subIndex(element,localKey.subEntity(),1)) }};
      }
    return it;
  }
 
protected:
  const PreBasis* preBasis_;
 
  const Node* node_;
};
 
 
 
namespace BasisFactory {
 
namespace Imp {
 
template<class Dummy=void>
class RannacherTurekPreBasisFactory
{
public:
  static const std::size_t requiredMultiIndexSize = 1;
 
  template<class MultiIndex, class GridView>
  auto makePreBasis(const GridView& gridView) const
  {
    return RannacherTurekPreBasis<GridView, MultiIndex>(gridView);
  }
 
};
 
} // end namespace BasisFactory::Imp
 
 
 
template<class Dummy=void>
auto rannacherTurek()
{
  return Imp::RannacherTurekPreBasisFactory<void>();
}
 
} // end namespace BasisFactory
 
 
 
 
template<typename GV>
using RannacherTurekBasis = DefaultGlobalBasis<RannacherTurekPreBasis<GV, FlatMultiIndex<std::size_t> > >;
 
} // end namespace Functions
} // end namespace Dune
 
#endif // DUNE_FUNCTIONS_FUNCTIONSPACEBASES_RANNACHERTUREKBASIS_HH