functional.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2010 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------


#ifndef dealii_mesh_worker_functional_h
#define dealii_mesh_worker_functional_h

#include <deal.II/algorithms/any_data.h>
#include <deal.II/base/smartpointer.h>
#include <deal.II/base/mg_level_object.h>
#include <deal.II/lac/block_vector.h>
#include <deal.II/meshworker/dof_info.h>
#include <deal.II/multigrid/mg_constrained_dofs.h>


DEAL_II_NAMESPACE_OPEN

namespace MeshWorker
{
  namespace Assembler
  {
    template <typename number = double>
    class Functional
    {
    public:
      void initialize(const unsigned int n);
      template <class DOFINFO>
      void initialize_info(DOFINFO &info, bool face);

      template <class DOFINFO>
      void assemble(const DOFINFO &info);

      template <class DOFINFO>
      void assemble(const DOFINFO &info1,
                    const DOFINFO &info2);

      number operator() (const unsigned int i) const;
    private:
      std::vector<double> results;
    };

    template <typename number = double>
    class CellsAndFaces
    {
    public:
      CellsAndFaces();

      void initialize(AnyData &results, bool separate_faces = true);

      template <class DOFINFO>
      void initialize_info(DOFINFO &info, bool face) const;

      template <class DOFINFO>
      void assemble(const DOFINFO &info);

      template <class DOFINFO>
      void assemble(const DOFINFO &info1,
                    const DOFINFO &info2);

      number operator() (const unsigned int i) const;
    private:
      AnyData results;
      bool separate_faces;
    };
//----------------------------------------------------------------------//

    template <typename number>
    inline void
    Functional<number>::initialize(const unsigned int n)
    {
      results.resize(n);
      std::fill(results.begin(), results.end(), 0.);
    }


    template <typename number>
    template <class DOFINFO>
    inline void
    Functional<number>::initialize_info(DOFINFO &info, bool)
    {
      info.initialize_numbers(results.size());
    }


    template <typename number>
    template <class DOFINFO>
    inline void
    Functional<number>::assemble(const DOFINFO &info)
    {
      for (unsigned int i=0; i<results.size(); ++i)
        results[i] += info.value(i);
    }


    template <typename number>
    template <class DOFINFO>
    inline void
    Functional<number>::assemble(const DOFINFO &info1,
                                 const DOFINFO &info2)
    {
      for (unsigned int i=0; i<results.size(); ++i)
        {
          results[i] += info1.value(i);
          results[i] += info2.value(i);
        }
    }


    template <typename number>
    inline number
    Functional<number>::operator() (const unsigned int i) const
    {
      AssertIndexRange(i, results.size());
      return results[i];
    }

//----------------------------------------------------------------------//

    template <typename number>
    inline
    CellsAndFaces<number>::CellsAndFaces()
      : separate_faces(true)
    {}



    template <typename number>
    inline void
    CellsAndFaces<number>::initialize(AnyData &r, bool sep)
    {
      Assert(r.name(0) == "cells", AnyData::ExcNameMismatch(0, "cells"));
      if (sep)
        {
          Assert(r.name(1) == "faces", AnyData::ExcNameMismatch(1, "faces"));
          AssertDimension(r.entry<BlockVector<double>*>(0)->n_blocks(),
                          r.entry<BlockVector<double>*>(1)->n_blocks());
        }

      results = r;
      separate_faces = sep;
    }

    template <typename number>
    template <class DOFINFO>
    inline void
    CellsAndFaces<number>::initialize_info(DOFINFO &info, bool) const
    {
      info.initialize_numbers(results.entry<BlockVector<double>*>(0)->n_blocks());
    }


    template <typename number>
    template <class DOFINFO>
    inline void
    CellsAndFaces<number>::assemble(const DOFINFO &info)
    {
      BlockVector<double> *v;
      if (separate_faces &&
          info.face_number != numbers::invalid_unsigned_int)
        v = results.entry<BlockVector<double>*>(1);
      else
        v = results.entry<BlockVector<double>*>(0);

      for (unsigned int i=0; i<info.n_values(); ++i)
        v->block(i)(info.cell->user_index()) += info.value(i);
    }


    template <typename number>
    template <class DOFINFO>
    inline void
    CellsAndFaces<number>::assemble(const DOFINFO &info1,
                                    const DOFINFO &info2)
    {
      for (unsigned int i=0; i<info1.n_values(); ++i)
        {
          if (separate_faces)
            {
              BlockVector<double> *v1 = results.entry<BlockVector<double>*>(1);
              const double J = info1.value(i) + info2.value(i);
              v1->block(i)(info1.face->user_index()) += J;
              if (info2.face != info1.face)
                v1->block(i)(info2.face->user_index()) += J;
            }
          else
            {
              BlockVector<double> *v0 = results.entry<BlockVector<double>*>(0);
              v0->block(i)(info1.cell->user_index()) += .5*info1.value(i);
              v0->block(i)(info2.cell->user_index()) += .5*info2.value(i);
            }
        }
    }
  }
}

DEAL_II_NAMESPACE_CLOSE

#endif