divergencemodel.hh

#ifndef __DUNE_ACFEM_MODELS_MODULES_DIVERGENCEMODEL_HH__
#define __DUNE_ACFEM_MODELS_MODULES_DIVERGENCEMODEL_HH__
 
#include "../operatorparts/modeladapter.hh"
 
namespace Dune {
 
  namespace ACFem {
 
    template<class GridFunction>
    class DivergenceOperatorParts
      : public OperatorPartsExpression<DivergenceOperatorParts<GridFunction> >
    {
      typedef DivergenceOperatorParts           ThisType;
      typedef DefaultOperatorParts<ThisType>    BaseType;
      typedef OperatorPartsInterface<ThisType>  InterfaceType;
      typedef OperatorPartsTraits<ThisType>     TraitsType;
      typedef typename GridFunction::LocalFunctionType LocalFunctionType;
     public:
      typedef GridFunction DivergenceFunctionType;
      typedef typename DivergenceFunctionType::DiscreteFunctionSpaceType::FunctionSpaceType DivergenceFunctionSpaceType;
      typedef typename TraitsType::FunctionSpaceType FunctionSpaceType;
 
      typedef typename FunctionSpaceType::DomainType DomainType;
      typedef typename FunctionSpaceType::RangeType RangeType;
      typedef typename FunctionSpaceType::JacobianRangeType JacobianRangeType;
      typedef typename FunctionSpaceType::HessianRangeType HessianRangeType;
 
      enum {
        dimDomain = FunctionSpaceType::dimDomain,
        dimRange = FunctionSpaceType::dimRange,
        dimWorld = dimDomain
      };
 
      static_assert(dimRange == 1 && dimDomain == dimWorld,
                    "This is meant for dimRange = 1, i.e. velocity divergences and such.");
 
      DivergenceOperatorParts(const Fem::Function<DivergenceFunctionSpaceType, DivergenceFunctionType>& function,
                    const std::string& name = "")
        : function_(function),
          localFunction_(function_()),
          name_(name == "" ? "(div " + function_().name() + ")" : name)
      {}
 
      std::string name() const
      {
        return name_;
      }
 
      // Interface methods that need to be reimplemented
 
      template<class Entity>
      void setEntity(const Entity& entity) const
      {
        localFunction_.init(entity);
      }
 
      template<class Entity, class Point>
      void source(const Entity& entity,
                  const Point &x,
                  const RangeType& value,
                  const JacobianRangeType& jacobian,
                  RangeType& result) const
      {
        typename DivergenceFunctionType::JacobianRangeType divJacobian;
        localFunction_.jacobian(x, divJacobian);
 
        result = 0;
        for (int i = 0; i < FunctionSpaceType::dimDomain; ++i) {
          result[0] += divJacobian[i][i];
        }
      }
 
      template<class Entity, class Point>
      void linearizedSource(const RangeType& uBar,
                            const JacobianRangeType& DuBar,
                            const Entity& entity,
                            const Point &x,
                            const RangeType& value,
                            const JacobianRangeType& jacobian,
                            RangeType& result) const
      {
        result = 0;
      }
 
     protected:
      ExpressionStorage<DivergenceFunctionType> function_;
      mutable LocalFunctionType localFunction_;
      const std::string name_;
    };
 
    template<class GridFunction>
    struct OperatorPartsTraits<DivergenceOperatorParts<GridFunction> >
      : public DefaultOperatorPartsTraits<typename Fem::ToNewDimRangeFunctionSpace<typename GridFunction::FunctionSpaceType, 1>::Type>
    {
      //Only for scalar GridFunction classes
      static_assert(GridFunction::DiscreteFunctionSpaceType::FunctionSpaceType::dimRange
                    ==
                    GridFunction::DiscreteFunctionSpaceType::FunctionSpaceType::dimDomain,
                    "The divergence model is only for dimDomain-valued grid-functions defined");
 
      enum StructureFlags
      {
        isLinear = true, // it is even constant
        isSymmetric = true, // it is even constant
        isSemiDefinite = true, // it is even constant
      };
 
      enum ConstituentFlags {
        hasFlux = false,
        hasSources = true,
        hasRobinFlux = false,
      };
    };
 
 
 
    template<class GridFunction>
    static inline
    DivergenceOperatorParts<GridFunction>
    divergenceOperatorParts(const Fem::Function<typename GridFunction::FunctionSpaceType, GridFunction>& f,
                           const std::string& name = "")
    {
      typedef DivergenceOperatorParts<GridFunction> OperatorPartsType;
      return OperatorPartsType(f, name);
    }
 
    template<class GridFunction>
    static inline
    OperatorPartsAdapterModel<DivergenceOperatorParts<GridFunction>,
                              typename GridFunction::GridPartType>
    divergenceModel(const Fem::Function<typename GridFunction::FunctionSpaceType, GridFunction>& f,
                    const std::string& name = "")
    {
      typedef DivergenceOperatorParts<GridFunction> OperatorPartsType;
      typedef typename GridFunction::GridPartType GridPartType;
      return OperatorPartsAdapterModel<OperatorPartsType, GridPartType>(OperatorPartsType(f, name));
    }
 
 
 
 
  } // namespace ACFem
 
}  //Namespace Dune
 
 
#endif // __DUNE_ACFEM_MODELS_MODULES_DIVERGENCEMODEL_HH__