domain_disc_impl.h

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/*
 * Copyright (c) 2010-2015:  G-CSC, Goethe University Frankfurt
 * Author: Andreas Vogel
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 */
 
#ifndef __H__UG__LIB_DISC__SPATIAL_DISC__DOMAIN_DISC_IMPL__
#define __H__UG__LIB_DISC__SPATIAL_DISC__DOMAIN_DISC_IMPL__
 
#include "common/profiler/profiler.h"
#include "domain_disc.h"
#include "lib_disc/common/groups_util.h"
#include "lib_disc/function_spaces/error_indicator_util.h"
#include "lib_disc/spatial_disc/subset_assemble_util.h"
#ifdef UG_PARALLEL
#include "lib_disc/parallelization/parallelization_util.h"
#endif
#include "lib_grid/algorithms/debug_util.h"
 
namespace ug{
 
template <class TElemDisc>
static void prep_assemble_loop(std::vector<TElemDisc*> vElemDisc)
{
  for(size_t i = 0; i < vElemDisc.size(); ++i)
  {
    vElemDisc[i]->prep_assemble_loop();
  }
}
 
template <class TElemDisc>
static void post_assemble_loop(std::vector<TElemDisc*> vElemDisc)
{
  for(size_t i = 0; i < vElemDisc.size(); ++i)
  {
    vElemDisc[i]->post_assemble_loop();
  }
}
 
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::update_elem_discs()
{
//  check Approximation space
  if(!m_spApproxSpace.valid())
    UG_THROW("DomainDiscretization: Before using the "
        "DomainDiscretization an ApproximationSpace must be set to it. "
        "Please use DomainDiscretization:set_approximation_space to "
        "set an appropriate Space.");
 
//  set approximation space and extract IElemDiscs
  m_vElemDisc.clear();
  for(size_t i = 0; i < m_vDomainElemDisc.size(); ++i)
  {
    m_vDomainElemDisc[i]->set_approximation_space(m_spApproxSpace);
 
    if(!(m_spAssTuner->elem_disc_type_enabled(m_vDomainElemDisc[i]->type()))) continue;
    m_vElemDisc.push_back(m_vDomainElemDisc[i].get());
  }
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::update_elem_errors()
{
//  check Approximation space
  if(!m_spApproxSpace.valid())
    UG_THROW("DomainDiscretization: Before using the "
        "DomainDiscretization an ApproximationSpace must be set to it. "
        "Please use DomainDiscretization:set_approximation_space to "
        "set an appropriate Space.");
 
//  set approximation space and extract IElemDiscs
  m_vElemError.clear();
  for(size_t i = 0; i < m_vDomainElemError.size(); ++i)
  {
    m_vDomainElemError[i]->set_approximation_space(m_spApproxSpace);
 
    if(!(m_spAssTuner->elem_disc_type_enabled(m_vDomainElemError[i]->type()))) continue;
    m_vElemError.push_back(m_vDomainElemError[i].get());
  }
 
}
 
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::update_constraints()
{
//  check Approximation space
  if(!m_spApproxSpace.valid())
    UG_THROW("DomainDiscretization: Before using the "
        "DomainDiscretization an ApproximationSpace must be set to it. "
        "Please use DomainDiscretization:set_approximation_space to "
        "set an appropriate Space.");
 
 
  for(size_t i = 0; i < m_vConstraint.size(); ++i)
    m_vConstraint[i]->set_approximation_space(m_spApproxSpace);
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::update_disc_items()
{
  update_elem_discs();
  update_constraints();
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::update_error_items()
{
  update_elem_errors();
  update_constraints();
}
 
// Mass Matrix
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_mass_matrix(matrix_type& M, const vector_type& u,
                     ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, M);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleMassMatrix<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      break;
    case 1:
      this->template AssembleMassMatrix<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleMassMatrix<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      break;
    case 2:
      this->template AssembleMassMatrix<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      this->template AssembleMassMatrix<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleMassMatrix<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      this->template AssembleMassMatrix<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      break;
    case 3:
      this->template AssembleMassMatrix<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      this->template AssembleMassMatrix<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      this->template AssembleMassMatrix<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      this->template AssembleMassMatrix<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      this->template AssembleMassMatrix<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, M, u);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_mass_matrix:"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_mass_matrix:"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_jacobian(M, u, dd, type);
      }
  }
  post_assemble_loop(m_vElemDisc);
  }UG_CATCH_THROW("DomainDiscretization::assemble_mass_matrix:"
          " Cannot execute post process.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  M.set_storage_type(PST_ADDITIVE);
  M.set_layouts(dd->layouts());
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleMassMatrix( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
          ConstSmartPtr<DoFDistribution> dd,
          int si, bool bNonRegularGrid,
          matrix_type& M,
          const vector_type& u)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleMassMatrix<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, M, u, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleMassMatrix<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, M, u, m_spAssTuner);
  }
}
 
// Stiffness Matrix
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_stiffness_matrix(matrix_type& A, const vector_type& u,
                          ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, A);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleStiffnessMatrix<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      break;
    case 1:
      this->template AssembleStiffnessMatrix<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleStiffnessMatrix<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      break;
    case 2:
      this->template AssembleStiffnessMatrix<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      this->template AssembleStiffnessMatrix<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleStiffnessMatrix<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      this->template AssembleStiffnessMatrix<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      break;
    case 3:
      this->template AssembleStiffnessMatrix<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      this->template AssembleStiffnessMatrix<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      this->template AssembleStiffnessMatrix<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      this->template AssembleStiffnessMatrix<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      this->template AssembleStiffnessMatrix<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, A, u);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_stiffness_matrix:"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_stiffness_matrix:"
          " Assembling of elements of Dimension " << dim << " in "
          " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_jacobian(A, u, dd, type);
      }
  }
  post_assemble_loop(m_vElemDisc);
  }UG_CATCH_THROW("DomainDiscretization::assemble_stiffness_matrix:"
          " Cannot execute post process.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  A.set_storage_type(PST_ADDITIVE);
  A.set_layouts(dd->layouts());
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleStiffnessMatrix(  const std::vector<IElemDisc<domain_type>*>& vElemDisc,
              ConstSmartPtr<DoFDistribution> dd,
              int si, bool bNonRegularGrid,
              matrix_type& A,
              const vector_type& u)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleStiffnessMatrix<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, A, u, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleStiffnessMatrix<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, A, u, m_spAssTuner);
  }
}
 
//  Time Independent (stationary)
 
 
// Jacobian (stationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_jacobian(matrix_type& J,
                  const vector_type& u,
                  ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, J);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  pre process -  modifies the solution, used for computing the defect
  const vector_type* pModifyU = &u;
  SmartPtr<vector_type> pModifyMemory;
  if( m_spAssTuner->modify_solution_enabled() ){
    pModifyMemory = u.clone();
    pModifyU = pModifyMemory.get();
    try{
    for(int type = 1; type < CT_ALL; type = type << 1){
      if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
      for(size_t i = 0; i < m_vConstraint.size(); ++i)
        if(m_vConstraint[i]->type() & type)
          m_vConstraint[i]->modify_solution(*pModifyMemory, u, dd, type);
    }
    } UG_CATCH_THROW("Cannot modify solution.");
  }
 
 
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleJacobian<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      break;
    case 1:
      this->template AssembleJacobian<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleJacobian<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      break;
    case 2:
      this->template AssembleJacobian<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      this->template AssembleJacobian<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleJacobian<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      this->template AssembleJacobian<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      break;
    case 3:
      this->template AssembleJacobian<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      this->template AssembleJacobian<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      this->template AssembleJacobian<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      this->template AssembleJacobian<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      this->template AssembleJacobian<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, *pModifyU);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_jacobian (stationary):"
              "Dimension "<<dim<<"(subset="<<si<<") not supported");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_jacobian (stationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_jacobian(J, *pModifyU, dd, type);
      }
  }
  post_assemble_loop(m_vElemDisc);
  }UG_CATCH_THROW("DomainDiscretization::assemble_jacobian:"
          " Cannot execute post process.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  J.set_storage_type(PST_ADDITIVE);
  J.set_layouts(dd->layouts());
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleJacobian( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
          ConstSmartPtr<DoFDistribution> dd,
          int si, bool bNonRegularGrid,
          matrix_type& J,
          const vector_type& u)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleJacobian<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, J, u, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleJacobian<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, J, u, m_spAssTuner);
  }
}
 
// Defect (stationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_defect(vector_type& d,
                const vector_type& u,
                ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, d);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  pre process -  modifies the solution, used for computing the defect
  const vector_type* pModifyU = &u;
  SmartPtr<vector_type> pModifyMemory;
  if( m_spAssTuner->modify_solution_enabled() ){
    pModifyMemory = u.clone();
    pModifyU = pModifyMemory.get();
    try{
    for(int type = 1; type < CT_ALL; type = type << 1){
      if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
      for(size_t i = 0; i < m_vConstraint.size(); ++i)
        if(m_vConstraint[i]->type() & type)
          m_vConstraint[i]->modify_solution(*pModifyMemory, u, dd, type);
    }
    } UG_CATCH_THROW("Cannot modify solution.");
  }
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleDefect<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      break;
    case 1:
      this->template AssembleDefect<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleDefect<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      break;
    case 2:
      this->template AssembleDefect<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      this->template AssembleDefect<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleDefect<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      this->template AssembleDefect<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      break;
    case 3:
      this->template AssembleDefect<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      this->template AssembleDefect<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      this->template AssembleDefect<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      this->template AssembleDefect<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      this->template AssembleDefect<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, *pModifyU);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_defect (stationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_defect (stationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
 
  // Dirichlet first, since hanging nodes might be constrained by Dirichlet nodes
  if (m_spAssTuner->constraint_type_enabled(CT_DIRICHLET))
  {
    for (size_t i = 0; i < m_vConstraint.size(); ++i)
    {
      if (m_vConstraint[i]->type() & CT_DIRICHLET)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_defect(d, *pModifyU, dd, CT_DIRICHLET);
      }
    }
  }
 
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_defect(d, *pModifyU, dd, type);
      }
  }
  post_assemble_loop(m_vElemDisc);
  } UG_CATCH_THROW("Cannot adjust defect.");
 
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  d.set_storage_type(PST_ADDITIVE);
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleDefect( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        vector_type& d,
        const vector_type& u)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleDefect<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, d, u, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleDefect<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, d, u, m_spAssTuner);
  }
}
 
// Matrix and RHS (stationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_linear(matrix_type& mat, vector_type& rhs,
                ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, mat);
  m_spAssTuner->resize(dd, rhs);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("DomainDiscretization: Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleLinear<RegularVertex>
          (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      break;
    case 1:
      this->template AssembleLinear<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleLinear<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      break;
    case 2:
      this->template AssembleLinear<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      this->template AssembleLinear<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleLinear<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      this->template AssembleLinear<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      break;
    case 3:
      this->template AssembleLinear<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      this->template AssembleLinear<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      this->template AssembleLinear<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      this->template AssembleLinear<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      this->template AssembleLinear<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_linear (stationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_linear (stationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_linear(mat, rhs, dd, type);
      }
  }
  post_assemble_loop(m_vElemDisc);
  }UG_CATCH_THROW("DomainDiscretization::assemble_linear: Cannot post process.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  mat.set_storage_type(PST_ADDITIVE);
  mat.set_layouts(dd->layouts());
  rhs.set_storage_type(PST_ADDITIVE);
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleLinear( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        matrix_type& A,
        vector_type& rhs)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleLinear<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, A, rhs, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleLinear<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, A, rhs, m_spAssTuner);
  }
}
 
// RHS (stationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_rhs(vector_type& rhs,
      const vector_type& u,
      ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, rhs);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleRhs<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      break;
    case 1:
      this->template AssembleRhs<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleRhs<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      break;
    case 2:
      this->template AssembleRhs<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      this->template AssembleRhs<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleRhs<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      this->template AssembleRhs<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      break;
    case 3:
      this->template AssembleRhs<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      this->template AssembleRhs<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      this->template AssembleRhs<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      this->template AssembleRhs<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      this->template AssembleRhs<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, u);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_rhs (stationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_rhs (stationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_rhs(rhs, u, dd, type);
      }
  }
  post_assemble_loop(m_vElemDisc);
  }UG_CATCH_THROW("DomainDiscretization::assemble_rhs:"
          " Cannot execute post process.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  rhs.set_storage_type(PST_ADDITIVE);
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleRhs(  const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        vector_type& rhs,
        const vector_type& u)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleRhs<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, rhs, u, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleRhs<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, rhs, u, m_spAssTuner);
  }
}
 
// set constraints (stationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
adjust_solution(vector_type& u, ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
  update_constraints();
 
  // NOTE: it is crucial, that dirichlet pp are processed before constraints.
  //     otherwise we may start with an inconsistent solution in the solvers
  std::vector<int> vType(6);
  vType[0] = CT_DIRICHLET;  // hanging (or other constrained) nodes might depend on Dirichlet nodes
  vType[1] = CT_CONSTRAINTS;
  vType[2] = CT_HANGING;
  vType[3] = CT_MAY_DEPEND_ON_HANGING;
  vType[4] = CT_ASSEMBLED;
  vType[5] = CT_DIRICHLET;  // hanging DoFs might be Dirichlet (Dirichlet overrides)
 
  // if assembling is carried out at one DoF only, u needs to be resized
  if (m_spAssTuner->single_index_assembling_enabled()) u.resize(1);
 
  try{
  for(size_t i = 0; i < vType.size(); ++i){
    int type = vType[i];
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_solution(u, dd, type);
      }
  }
 
  } UG_CATCH_THROW("Cannot adjust solution.");
}
 
 
 
 
//  Time Dependent (instationary)
 
// Prepare Timestep (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
prepare_timestep
(
  ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
  number future_time,
  ConstSmartPtr<DoFDistribution> dd
)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  find out whether grid is regular
  ConstSmartPtr<ISubsetHandler> sh = dd->subset_handler();
  size_t num_subsets = sh->num_subsets();
  bool bNonRegularGrid = false;
  for (size_t si = 0; si < num_subsets; ++si)
    bNonRegularGrid |= !SubsetIsRegularGrid(*sh, si);
 
//  overrule by regular grid if required
  if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
//  call assembler's PrepareTimestep
  try
  {
    gass_type::PrepareTimestep(m_vElemDisc, dd, bNonRegularGrid, vSol, future_time, m_spAssTuner);
  }
  UG_CATCH_THROW("DomainDiscretization::prepare_timestep (instationary):" <<
           " Preparing time step failed.");
 
  post_assemble_loop(m_vElemDisc);
}
 
// Prepare Timestep Elem (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
prepare_timestep_elem(ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
                ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template PrepareTimestepElem<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    case 1:
      this->template PrepareTimestepElem<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template PrepareTimestepElem<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    case 2:
      this->template PrepareTimestepElem<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template PrepareTimestepElem<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template PrepareTimestepElem<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template PrepareTimestepElem<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    case 3:
      this->template PrepareTimestepElem<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template PrepareTimestepElem<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template PrepareTimestepElem<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template PrepareTimestepElem<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template PrepareTimestepElem<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    default:
      UG_THROW("DomainDiscretization::prepare_timestep_elem (instationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::prepare_timestep_elem (instationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
  post_assemble_loop(m_vElemDisc);
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
PrepareTimestepElem(const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        ConstSmartPtr<VectorTimeSeries<vector_type> > vSol)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template PrepareTimestepElem<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, vSol, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template PrepareTimestepElem<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, vSol, m_spAssTuner);
  }
}
 
// Jacobian (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_jacobian(matrix_type& J,
                  ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
                  const number s_a0,
                  ConstSmartPtr<DoFDistribution> dd)
{
  // do not do anything if matrix is supposed to be const
  if (m_spAssTuner->matrix_is_const()) return;
 
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset matrix to zero and resize
  m_spAssTuner->resize(dd, J);
 
//  get current time
  const number time = vSol->time(0);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  preprocess -  modifies the solution, used for computing the defect
  ConstSmartPtr<VectorTimeSeries<vector_type> > pModifyU = vSol;
  SmartPtr<VectorTimeSeries<vector_type> > pModifyMemory;
  if( m_spAssTuner->modify_solution_enabled() ){
    pModifyMemory = vSol->clone();
    pModifyU = pModifyMemory;
    try{
    for(int type = 1; type < CT_ALL; type = type << 1){
      if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
      for(size_t i = 0; i < m_vConstraint.size(); ++i)
        if(m_vConstraint[i]->type() & type)
          m_vConstraint[i]->modify_solution(pModifyMemory, vSol, dd, type);
    }
    } UG_CATCH_THROW("'DomainDiscretization': Cannot modify solution.");
  }
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleJacobian<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      break;
    case 1:
      this->template AssembleJacobian<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleJacobian<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      break;
    case 2:
      this->template AssembleJacobian<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      this->template AssembleJacobian<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleJacobian<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      this->template AssembleJacobian<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      break;
    case 3:
      this->template AssembleJacobian<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      this->template AssembleJacobian<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      this->template AssembleJacobian<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      this->template AssembleJacobian<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      this->template AssembleJacobian<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, J, pModifyU, s_a0);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_jacobian (instationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_jacobian (instationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_jacobian(J, *pModifyU->solution(0), dd, type, time, pModifyU,s_a0);
      }
  }
  post_assemble_loop(m_vElemDisc);
  }UG_CATCH_THROW("Cannot adjust jacobian.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  J.set_storage_type(PST_ADDITIVE);
  J.set_layouts(dd->layouts());
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleJacobian( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
          ConstSmartPtr<DoFDistribution> dd,
          int si, bool bNonRegularGrid,
          matrix_type& J,
          ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
          number s_a0)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
  
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleJacobian<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, J, vSol, s_a0, m_spAssTuner);
  }
  else
  {
    gass_type::template AssembleJacobian<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, J, vSol, s_a0, m_spAssTuner);
  }
}
 
// Defect (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_defect(vector_type& d,
                ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
                const std::vector<number>& vScaleMass,
                const std::vector<number>& vScaleStiff,
                ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  reset vector to zero and resize
  m_spAssTuner->resize(dd, d);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  pre process -  modifies the solution, used for computing the defect
  ConstSmartPtr<VectorTimeSeries<vector_type> > pModifyU = vSol;
  SmartPtr<VectorTimeSeries<vector_type> > pModifyMemory;
  if( m_spAssTuner->modify_solution_enabled() ){
    pModifyMemory = vSol->clone();
    pModifyU = pModifyMemory;
    try{
    for(int type = 1; type < CT_ALL; type = type << 1){
      if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
      for(size_t i = 0; i < m_vConstraint.size(); ++i)
        if(m_vConstraint[i]->type() & type)
          m_vConstraint[i]->modify_solution(pModifyMemory, vSol, dd, type);
    }
    } UG_CATCH_THROW("'DomainDiscretization: Cannot modify solution.");
  }
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleDefect<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      break;
    case 1:
      this->template AssembleDefect<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleDefect<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      break;
    case 2:
      this->template AssembleDefect<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      this->template AssembleDefect<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleDefect<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      this->template AssembleDefect<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      break;
    case 3:
      this->template AssembleDefect<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      this->template AssembleDefect<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      this->template AssembleDefect<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      this->template AssembleDefect<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      this->template AssembleDefect<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, d, pModifyU, vScaleMass, vScaleStiff);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_defect (instationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_defect (instationary):"
            " Assembling of elements of Dimension " << dim << " in"
            " subset "<< si << " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_defect(d, *pModifyU->solution(0), dd, type, pModifyU->time(0), pModifyU, &vScaleMass, &vScaleStiff);
      }
  }
  post_assemble_loop(m_vElemDisc);
  } UG_CATCH_THROW("Cannot adjust defect.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  d.set_storage_type(PST_ADDITIVE);
#endif
}
 
/*
 * This function adds the contributions of all passed element discretizations
 * on one given subset to the global Defect in the instationary case.
 *
 * \param[in]   vElemDisc   element discretizations
 * \param[in]   dd        DoF Distribution
 * \param[in]   si        subset index
 * \param[in]   bNonRegularGrid flag to indicate if non regular grid is used
 * \param[in,out] d       defect
 * \param[in]   vSol      current and previous solutions
 * \param[in]   vScaleMass    scaling factors for mass part
 * \param[in]   vScaleStiff   scaling factors for stiffness part
 */
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleDefect( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        vector_type& d,
        ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
        const std::vector<number>& vScaleMass,
        const std::vector<number>& vScaleStiff)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
    
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleDefect<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, d, vSol, vScaleMass, vScaleStiff, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleDefect<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, d, vSol, vScaleMass, vScaleStiff, m_spAssTuner);
  }
}
 
// Matrix and RHS (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_linear(matrix_type& mat, vector_type& rhs,
                ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
                const std::vector<number>& vScaleMass,
                const std::vector<number>& vScaleStiff,
                ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
 
//  reset matrix to zero and resize
  if (!m_spAssTuner->matrix_is_const())
    m_spAssTuner->resize(dd, mat);
  m_spAssTuner->resize(dd, rhs);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleLinear<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    case 1:
      this->template AssembleLinear<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleLinear<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    case 2:
      this->template AssembleLinear<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleLinear<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleLinear<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleLinear<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    case 3:
      this->template AssembleLinear<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleLinear<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleLinear<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleLinear<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleLinear<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, mat, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_linear (instationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_linear (instationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_linear(mat, rhs, dd, type, vSol->time(0));
      }
  }
  } UG_CATCH_THROW("Cannot adjust linear.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  mat.set_storage_type(PST_ADDITIVE);
  mat.set_layouts(dd->layouts());
 
  rhs.set_storage_type(PST_ADDITIVE);
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleLinear( const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        matrix_type& A,
        vector_type& rhs,
        ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
        const std::vector<number>& vScaleMass,
        const std::vector<number>& vScaleStiff)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleLinear<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, A, rhs, vSol, vScaleMass, vScaleStiff, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleLinear<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, A, rhs, vSol, vScaleMass, vScaleStiff, m_spAssTuner);
  }
}
 
// RHS (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
assemble_rhs(vector_type& rhs,
             ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
             const std::vector<number>& vScaleMass,
             const std::vector<number>& vScaleStiff,
             ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
 
//  reset vector to zero and resize
  m_spAssTuner->resize(dd, rhs);
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template AssembleRhs<RegularVertex>
         (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    case 1:
      this->template AssembleRhs<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleRhs<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    case 2:
      this->template AssembleRhs<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleRhs<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template AssembleRhs<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleRhs<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    case 3:
      this->template AssembleRhs<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleRhs<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleRhs<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleRhs<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      this->template AssembleRhs<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff);
      break;
    default:
      UG_THROW("DomainDiscretization::assemble_rhs (instationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::assemble_rhs (instationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
 
//  post process
  try{
  for(int type = 1; type < CT_ALL; type = type << 1){
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_rhs(rhs, *(vSol->solution(0)), dd, type, vSol->time(0));
      }
  }
  } UG_CATCH_THROW("Cannot adjust linear.");
 
//  Remember parallel storage type
#ifdef UG_PARALLEL
  rhs.set_storage_type(PST_ADDITIVE);
#endif
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleRhs(  const std::vector<IElemDisc<domain_type>*>& vElemDisc,
        ConstSmartPtr<DoFDistribution> dd,
        int si, bool bNonRegularGrid,
        vector_type& rhs,
        ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
        const std::vector<number>& vScaleMass,
        const std::vector<number>& vScaleStiff)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template AssembleRhs<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template AssembleRhs<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, rhs, vSol, vScaleMass, vScaleStiff, m_spAssTuner);
  }
}
 
// set constraint values (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
adjust_solution(vector_type& u, number time, ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
  update_constraints();
 
  // NOTE: it is crucial, that dirichlet pp are processed before constraints.
  //     otherwise we may start with an inconsistent solution in the solvers
  std::vector<int> vType(5);
  vType[0] = CT_DIRICHLET;  // hanging (or other constrained) nodes might depend on Dirichlet nodes
  vType[1] = CT_CONSTRAINTS;
  vType[2] = CT_HANGING;
  vType[3] = CT_MAY_DEPEND_ON_HANGING;
  vType[4] = CT_DIRICHLET;  // hanging DoFs might be Dirichlet (Dirichlet overrides)
 
  // if assembling is carried out at one DoF only, u needs to be resized
  if (m_spAssTuner->single_index_assembling_enabled()) u.resize(1);
 
  try{
 
//  constraints
  for(size_t i = 0; i < vType.size(); ++i){
    int type = vType[i];
    if(!(m_spAssTuner->constraint_type_enabled(type))) continue;
    for(size_t i = 0; i < m_vConstraint.size(); ++i)
      if(m_vConstraint[i]->type() & type)
      {
        m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
        m_vConstraint[i]->adjust_solution(u, dd, type, time);
      }
  }
  } UG_CATCH_THROW(" Cannot adjust solution.");
}
 
// Error estimator
 
template <typename TDomain, typename T>
void CollectIErrEstData(std::vector<IErrEstData<TDomain>*> &vErrEstData, const T &vElemDisc)
{
  for (std::size_t i = 0; i < vElemDisc.size(); ++i)
  {
    SmartPtr<IErrEstData<TDomain> > sp_err_est_data = vElemDisc[i]->err_est_data();
    IErrEstData<TDomain>* err_est_data = sp_err_est_data.get();
      if (err_est_data == NULL) continue; // no data specified
      if (std::find (vErrEstData.begin(), vErrEstData.end(), err_est_data) != vErrEstData.end())
        continue; // this one is already in the array
      if (err_est_data->consider_me()) vErrEstData.push_back(err_est_data);
  }
 
}
 
// Error estimator (stationary)
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
calc_error
(
  const vector_type& u,
  ConstSmartPtr<DoFDistribution> dd,
  error_vector_type* u_vtk
)
{
  PROFILE_FUNC_GROUP("error_estimator");
 
//  get multigrid
  SmartPtr<MultiGrid> pMG = ((DoFDistribution *) dd.get())->multi_grid();
 
// check, whether separate error data exists
  const bool useErrorData = !m_vDomainElemError.empty();
  // UG_LOG("useErrorData=" << (useErrorData) << std::endl);
 
//  update the elem discs
  if (useErrorData) { update_error_items();}
  else { update_disc_items();}
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try
  {
    if (useErrorData) { CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemError, dd->subset_handler());}
    else { CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());}
  }
  UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  get the error estimator data for all the discretizations
  std::vector<IErrEstData<TDomain>*> vErrEstData;
  if (useErrorData) CollectIErrEstData(vErrEstData, m_vElemError);
  else  CollectIErrEstData(vErrEstData, m_vElemDisc);
  /*for(std::size_t i = 0; i < m_vElemDisc.size(); ++i)
  {
    SmartPtr<IErrEstData<TDomain> > sp_err_est_data = m_vElemDisc[i]->err_est_data();
    IErrEstData<TDomain>* err_est_data = sp_err_est_data.get();
    if (err_est_data == NULL) continue; // no data specified
    if (std::find (vErrEstData.begin(), vErrEstData.end(), err_est_data) != vErrEstData.end())
      continue; // this one is already in the array
    if (err_est_data->consider_me()) vErrEstData.push_back(err_est_data);
  }*/
 
//  preprocess the error estimator data in the discretizations
  try
  {
    for (size_t i = 0; i < vErrEstData.size(); ++i)
      vErrEstData[i]->alloc_err_est_data(dd->surface_view(), dd->grid_level());
  }
  UG_CATCH_THROW("DomainDiscretization::calc_error: Cannot prepare the error estimator");
 
 
 
//  loop subsets to assemble the estimators
  for (size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  Elem Disc on the subset
    typedef typename std::vector<IElemError<TDomain>*> error_vector_type;
    error_vector_type vSubsetElemError;
 
  //  get all element discretizations that work on the subset
    GetElemDiscItemOnSubset<IElemError<TDomain>, IElemDisc<TDomain> > (vSubsetElemError, m_vElemDisc, vSSGrp, si);
    if (useErrorData)
    {
      GetElemDiscItemOnSubset<IElemError<TDomain>, IElemError<TDomain> >
      (vSubsetElemError, m_vElemError, vSSGrp, si);
    }
    else
    {
      GetElemDiscItemOnSubset<IElemError<TDomain>, IElemDisc<TDomain> >
      (vSubsetElemError, m_vElemDisc, vSSGrp, si);
    }
 
    /*
    UG_LOG("m_vElemDisc.size="<<m_vElemDisc.size()<< std::endl);
    UG_LOG("m_vElemError.size="<<m_vElemError.size()<< std::endl);
    UG_LOG("vSubsetElemError.size="<<vSubsetElemError.size()<< std::endl);
    */
 
  //  remove from elemDisc list those with !err_est_enabled()
    typename error_vector_type::iterator it = vSubsetElemError.begin();
    while (it != vSubsetElemError.end())
    {
      if (!(*it)->err_est_enabled())
        it = vSubsetElemError.erase(it);
      else ++it;
    }
  //  UG_LOG("vSubsetElemError.size="<<vSubsetElemError.size()<< std::endl);
 
  //  assemble on suitable elements
    try
    {
      switch (dim)
      {
      case 1:
        this->template AssembleErrorEstimator<RegularEdge>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        // When assembling over lower-dim manifolds that contain hanging nodes:
        this->template AssembleErrorEstimator<ConstrainingEdge>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        break;
      case 2:
        this->template AssembleErrorEstimator<Triangle>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        this->template AssembleErrorEstimator<Quadrilateral>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        // When assembling over lower-dim manifolds that contain hanging nodes:
        this->template AssembleErrorEstimator<ConstrainingTriangle>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        this->template AssembleErrorEstimator<ConstrainingQuadrilateral>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        break;
      case 3:
        this->template AssembleErrorEstimator<Tetrahedron>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        this->template AssembleErrorEstimator<Pyramid>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        this->template AssembleErrorEstimator<Prism>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        this->template AssembleErrorEstimator<Hexahedron>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        this->template AssembleErrorEstimator<Octahedron>
          (vSubsetElemError, dd, si, bNonRegularGrid, u);
        break;
      default:
        UG_THROW("DomainDiscretization::calc_error:"
                " Dimension "<<dim<<" (subset="<<si<<") not supported.");
      }
    }
    UG_CATCH_THROW("DomainDiscretization::calc_error:"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
//  apply constraints
  try
  {
    for (int type = 1; type < CT_ALL; type = type << 1)
    {
      if (!(m_spAssTuner->constraint_type_enabled(type))) continue;
      for (size_t i = 0; i < m_vConstraint.size(); ++i)
        if ((m_vConstraint[i]->type() & type) && m_vConstraint[i]->err_est_enabled())
        {
          m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
          m_vConstraint[i]->adjust_error(u, dd, type);
        }
    }
  }
  UG_CATCH_THROW("Cannot adjust error assemblings.");
 
//  summarize the error estimator data in the discretizations
  try
  {
    for (std::size_t i = 0; i < vErrEstData.size(); ++i)
      vErrEstData[i]->summarize_err_est_data(m_spApproxSpace->domain());
  }
  UG_CATCH_THROW("DomainDiscretization::calc_error: Cannot summarize the error estimator");
 
// perform integrations for error estimators and mark elements
  typedef typename domain_traits<dim>::element_type elem_type;
  typedef typename SurfaceView::traits<elem_type>::const_iterator elem_iter_type;
 
  m_mgElemErrors.attach_indicators(pMG);
 
  // loop surface elements
  ConstSmartPtr<SurfaceView> sv = dd->surface_view();
  const GridLevel& gl = dd->grid_level();
  elem_iter_type elem_iter_end = sv->template end<elem_type> (gl, SurfaceView::ALL);
  for (elem_iter_type elem = sv->template begin<elem_type> (gl, SurfaceView::ALL); elem != elem_iter_end; ++elem)
  {
    // clear attachment (to be on the safe side)
    m_mgElemErrors.error(*elem) = 0.0;
 
    // get corner coordinates
    std::vector<MathVector<dim> > vCornerCoords = std::vector<MathVector<dim> >(0);
    CollectCornerCoordinates(vCornerCoords, *elem, m_spApproxSpace->domain()->position_accessor(), false);
 
    // integrate for all estimators, then add up
    for (std::size_t ee = 0; ee < vErrEstData.size(); ++ee)
      m_mgElemErrors.error(*elem) += vErrEstData[ee]->scaling_factor()
                * vErrEstData[ee]->get_elem_error_indicator(*elem, &vCornerCoords[0]);
  }
 
//  write error estimator values to vtk
  if (u_vtk)
  {
    // local indices and solution
    LocalIndices ind; LocalVector locU;
 
    // cast u_vtk to grid_function
    GridFunction<TDomain, CPUAlgebra>* uVTK = dynamic_cast<GridFunction<TDomain, CPUAlgebra>*>(u_vtk);
    if (!uVTK)
    {
      UG_THROW("Argument passed as output for error function is not a GridFunction of suitable type.");
    }
 
    // clear previous values
    uVTK->set(0.0);
 
    // map attachments to grid function
    ConstSmartPtr<SurfaceView> sv = uVTK->approx_space()->dof_distribution(gl)->surface_view();
    elem_iter_type elem_iter_end = sv->template end<elem_type> (gl, SurfaceView::ALL);
    for (elem_iter_type elem = sv->template begin<elem_type> (gl, SurfaceView::ALL); elem != elem_iter_end; ++elem)
    {
      //  get global indices
      uVTK->approx_space()->dof_distribution(gl)->indices(*elem, ind, false);
 
      UG_COND_THROW(ind.num_fct() != 1,
        "Number of functions in grid function passed for error indicator values is not 1 on "
        << ElementDebugInfo(*uVTK->domain()->grid(), *elem) << ".");
 
      UG_COND_THROW(ind.num_dof(0) != 1,
        "Number of DoFs in grid function passed for error indicator values is not 1 on "
        << ElementDebugInfo(*uVTK->domain()->grid(), *elem) << ".");
 
      //  adapt local algebra
      locU.resize(ind);
 
      //  read local values of u
      GetLocalVector(locU, *uVTK);
 
      // assign error value
      locU(0,0) = m_mgElemErrors.error(*elem);
 
      // add to grid function
      AddLocalVector(*uVTK, locU);
    }
  }
 
  this->m_bErrorCalculated = true;
 
//  postprocess the error estimators in the discretizations
  try{
    for(std::size_t i = 0; i < vErrEstData.size(); ++i)
      vErrEstData[i]->release_err_est_data();
  }
  UG_CATCH_THROW("DomainDiscretization::calc_error: Cannot release the error estimator");
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
inline void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleErrorEstimator( const std::vector<IElemError<domain_type>*>& vElemDisc,
            ConstSmartPtr<DoFDistribution> dd,
            int si, bool bNonRegularGrid,
            const vector_type& u)
{
  //  general case: assembling over all elements in subset si
  gass_type::template AssembleErrorEstimator<TElem>
    (vElemDisc, m_spApproxSpace->domain(), dd,
      dd->template begin<TElem>(si), dd->template end<TElem>(si),
        si, bNonRegularGrid, u);
}
 
// Error estimator (instationary)
 
 
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
calc_error(ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
       ConstSmartPtr<DoFDistribution> dd,
       const std::vector<number>& vScaleMass,
       const std::vector<number>& vScaleStiff,
       error_vector_type* u_vtk)
{
  PROFILE_FUNC_GROUP("error_estimator");
 
//  get multigrid
  SmartPtr<MultiGrid> pMG = ((DoFDistribution *) dd.get())->multi_grid();
 
// check, whether separate error data exists
  const bool useErrorData = !m_vDomainElemError.empty();
 
//  update elem items
  if (useErrorData) { update_error_items();}
  else { update_disc_items();}
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try
  {
    if (useErrorData) {CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemError, dd->subset_handler());}
    else {CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());}
  }
  UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  collect the error estimator data (for all discretizations)
  std::vector<IErrEstData<TDomain>*> vErrEstData;
 
  if (useErrorData) CollectIErrEstData(vErrEstData, m_vElemError);
  else CollectIErrEstData(vErrEstData, m_vElemDisc);
 
//  preprocess the error estimator data in the discretizations
  try
  {
    for (std::size_t i = 0; i < vErrEstData.size(); ++i)
      vErrEstData[i]->alloc_err_est_data(dd->surface_view(), dd->grid_level());
  }
  UG_CATCH_THROW("DomainDiscretization::calc_error: Cannot prepare the error estimator");
 
//  loop subsets to assemble the estimators
  for (std::size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  collect all element discretizations that work on the subset
    typedef std::vector<IElemError<TDomain>*> error_vector_type;
    error_vector_type vSubsetElemError;
 
    if (useErrorData) {
       GetElemDiscItemOnSubset<IElemError<TDomain>, IElemError<TDomain> >
              (vSubsetElemError, m_vElemError, vSSGrp, si);
    }
    else
    {
       GetElemDiscItemOnSubset<IElemError<TDomain>, IElemDisc<TDomain> >
                    (vSubsetElemError, m_vElemDisc, vSSGrp, si);
    }
 
  //  remove from elemDisc list those with !err_est_enabled()
    typename error_vector_type::iterator it = vSubsetElemError.begin();
    while (it != vSubsetElemError.end())
    {
      if (!(*it)->err_est_enabled())
        it = vSubsetElemError.erase(it);
      else ++it;
    }
 
  //  assemble on suitable elements
    try
    {
      switch (dim)
      {
      case 1:
        this->template AssembleErrorEstimator<RegularEdge>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        // When assembling over lower-dim manifolds that contain hanging nodes:
        this->template AssembleErrorEstimator<ConstrainingEdge>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        break;
      case 2:
        this->template AssembleErrorEstimator<Triangle>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        this->template AssembleErrorEstimator<Quadrilateral>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        // When assembling over lower-dim manifolds that contain hanging nodes:
        this->template AssembleErrorEstimator<ConstrainingTriangle>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        this->template AssembleErrorEstimator<ConstrainingQuadrilateral>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        break;
      case 3:
        this->template AssembleErrorEstimator<Tetrahedron>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        this->template AssembleErrorEstimator<Pyramid>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        this->template AssembleErrorEstimator<Prism>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        this->template AssembleErrorEstimator<Hexahedron>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        this->template AssembleErrorEstimator<Octahedron>
          (vSubsetElemError, dd, si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
        break;
      default:
        UG_THROW("DomainDiscretization::calc_error:"
                " Dimension "<<dim<<" (subset="<<si<<") not supported.");
      }
    }
    UG_CATCH_THROW("DomainDiscretization::calc_error:"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<< si << "failed.");
  }
 
//  apply constraints
  try
  {
    for (int type = 1; type < CT_ALL; type = type << 1)
    {
      if (!(m_spAssTuner->constraint_type_enabled(type))) continue;
      for (size_t i = 0; i < m_vConstraint.size(); ++i)
        if ((m_vConstraint[i]->type() & type) && m_vConstraint[i]->err_est_enabled())
        {
          m_vConstraint[i]->set_ass_tuner(m_spAssTuner);
          m_vConstraint[i]->adjust_error(*vSol->solution(0), dd, type, vSol->time(0),
            vSol, &vScaleMass, &vScaleStiff);
        }
    }
  }
  UG_CATCH_THROW("Cannot adjust error assemblings.");
 
//  summarize the error estimator data in the discretizations
  try
  {
    for (std::size_t i = 0; i < vErrEstData.size(); ++i)
      vErrEstData[i]->summarize_err_est_data(m_spApproxSpace->domain());
  }
  UG_CATCH_THROW("DomainDiscretization::calc_error: Cannot summarize the error estimator.");
 
  // perform integrations for error estimators and mark elements
  typedef typename domain_traits<dim>::element_type elem_type;
  typedef typename SurfaceView::traits<elem_type>::const_iterator elem_iter_type;
 
  m_mgElemErrors.attach_indicators(pMG);
 
  // loop surface elements
  ConstSmartPtr<SurfaceView> sv = dd->surface_view();
  const GridLevel& gl = dd->grid_level();
  elem_iter_type elem_iter_end = sv->template end<elem_type> (gl, SurfaceView::ALL);
  for (elem_iter_type elem = sv->template begin<elem_type> (gl, SurfaceView::ALL); elem != elem_iter_end; ++elem)
  {
    // clear attachment
    m_mgElemErrors.error(*elem) = 0.0;
 
    // get corner coordinates
    std::vector<MathVector<dim> > vCornerCoords = std::vector<MathVector<dim> >(0);
    CollectCornerCoordinates(vCornerCoords, *elem, m_spApproxSpace->domain()->position_accessor(), false);
 
    // integrate for all estimators, then add up
    for (std::size_t ee = 0; ee < vErrEstData.size(); ++ee)
      m_mgElemErrors.error(*elem) += vErrEstData[ee]->scaling_factor()
                * vErrEstData[ee]->get_elem_error_indicator(*elem, &vCornerCoords[0]);
  }
 
//  write error estimator values to vtk
  if (u_vtk)
  {
    // local indices and solution
    LocalIndices ind; LocalVector locU;
 
    // cast u_vtk to grid_function
    GridFunction<TDomain,TAlgebra>* uVTK = dynamic_cast<GridFunction<TDomain,TAlgebra>*>(u_vtk);
    if (!uVTK)
    {
      UG_THROW("Argument passed as output for error function is not a GridFunction.");
    }
 
    // clear previous values
    uVTK->set(0.0);
 
    // map attachments to grid function
    ConstSmartPtr<SurfaceView> sv = uVTK->approx_space()->dof_distribution(gl)->surface_view();
    elem_iter_type elem_iter_end = sv->template end<elem_type> (gl, SurfaceView::ALL);
    for (elem_iter_type elem = sv->template begin<elem_type> (gl, SurfaceView::ALL); elem != elem_iter_end; ++elem)
    {
      //  get global indices
      uVTK->approx_space()->dof_distribution(gl)->indices(*elem, ind, false);
 
      //  adapt local algebra
      locU.resize(ind);
 
      //  read local values of u
      GetLocalVector(locU, *uVTK);
 
      // assign error value
      locU(0,0) = m_mgElemErrors.error(*elem);
 
      // add to grid function
      AddLocalVector(*uVTK, locU);
    }
  }
 
  this->m_bErrorCalculated = true;
 
//  postprocess the error estimators in the discretizations
  try{
    for(std::size_t i = 0; i < vErrEstData.size(); ++i)
      vErrEstData[i]->release_err_est_data();
  }
  UG_CATCH_THROW("DomainDiscretization::calc_error: Cannot release the error estimator");
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
inline void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
AssembleErrorEstimator( const std::vector<IElemError<domain_type>*>& vElemDisc,
            ConstSmartPtr<DoFDistribution> dd,
            int si, bool bNonRegularGrid,
            const std::vector<number>& vScaleMass,
            const std::vector<number>& vScaleStiff,
            ConstSmartPtr<VectorTimeSeries<vector_type> > vSol)
{
  //  general case: assembling over all elements in subset si
  gass_type::template AssembleErrorEstimator<TElem>
    (vElemDisc, m_spApproxSpace->domain(), dd,
      dd->template begin<TElem>(si), dd->template end<TElem>(si),
        si, bNonRegularGrid, vScaleMass, vScaleStiff, vSol);
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
mark_with_strategy
( IRefiner& refiner,
  SmartPtr<IElementMarkingStrategy<TDomain> >spMarkingStrategy
)
{
  // check that error indicators have been calculated
  if (!this->m_bErrorCalculated)
  {
    UG_THROW("Error indicators have to be calculated first by a call to 'calc_error'.");
  }
 
  // mark elements for refinement
  if (spMarkingStrategy.valid())
  {
    spMarkingStrategy->mark( m_mgElemErrors, refiner, this->dd(GridLevel(GridLevel::TOP, GridLevel::SURFACE)));
  }
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
invalidate_error()
{
  typedef typename domain_traits<dim>::element_type elem_type;
 
  // check that error indicators have been calculated
  if (m_bErrorCalculated)
  {
    m_bErrorCalculated = false;
    m_mgElemErrors.detach_indicators();
    // this->m_pMG->template detach_from<elem_type>(this->m_aError);
  }
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
bool DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
is_error_valid()
{
  // check that error indicators have been calculated
  return this->m_bErrorCalculated;
}
 
// Finish Timestep (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
finish_timestep
(
  ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
  ConstSmartPtr<DoFDistribution> dd
)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
  prep_assemble_loop(m_vElemDisc);
 
//  find out whether grid is regular
  ConstSmartPtr<ISubsetHandler> sh = dd->subset_handler();
  size_t num_subsets = sh->num_subsets();
  bool bNonRegularGrid = false;
  for (size_t si = 0; si < num_subsets; ++si)
    bNonRegularGrid |= !SubsetIsRegularGrid(*sh, si);
 
//  overrule by regular grid if required
  if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
//  call assembler's FinishTimestep
  try
  {
    gass_type::FinishTimestep(m_vElemDisc, dd, bNonRegularGrid, vSol, m_spAssTuner);
  }
  UG_CATCH_THROW("DomainDiscretization::finish_timestep (instationary):" <<
           " Finishing time step failed.");
 
  post_assemble_loop(m_vElemDisc);
}
 
// Finish Timestep Elem (instationary)
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
finish_timestep_elem(ConstSmartPtr<VectorTimeSeries<vector_type> > vSol,
                ConstSmartPtr<DoFDistribution> dd)
{
  PROFILE_FUNC_GROUP("discretization");
//  update the elem discs
  update_disc_items();
 
//  Union of Subsets
  SubsetGroup unionSubsets;
  std::vector<SubsetGroup> vSSGrp;
 
//  create list of all subsets
  try{
    CreateSubsetGroups(vSSGrp, unionSubsets, m_vElemDisc, dd->subset_handler());
  }UG_CATCH_THROW("'DomainDiscretization': Can not create Subset Groups and Union.");
 
//  loop subsets
  for(size_t i = 0; i < unionSubsets.size(); ++i)
  {
  //  get subset
    const int si = unionSubsets[i];
 
  //  get dimension of the subset
    const int dim = DimensionOfSubset(*dd->subset_handler(), si);
 
  //  request if subset is regular grid
    bool bNonRegularGrid = !unionSubsets.regular_grid(i);
 
  //  overrule by regular grid if required
    if(m_spAssTuner->regular_grid_forced()) bNonRegularGrid = false;
 
  //  Elem Disc on the subset
    std::vector<IElemDisc<TDomain>*> vSubsetElemDisc;
 
  //  get all element discretizations that work on the subset
    GetElemDiscOnSubset(vSubsetElemDisc, m_vElemDisc, vSSGrp, si);
 
  //  assemble on suitable elements
    try
    {
    switch(dim)
    {
    case 0:
      this->template FinishTimestepElem<RegularVertex>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    case 1:
      this->template FinishTimestepElem<RegularEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template FinishTimestepElem<ConstrainingEdge>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    case 2:
      this->template FinishTimestepElem<Triangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template FinishTimestepElem<Quadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      // When assembling over lower-dim manifolds that contain hanging nodes:
      this->template FinishTimestepElem<ConstrainingTriangle>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template FinishTimestepElem<ConstrainingQuadrilateral>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    case 3:
      this->template FinishTimestepElem<Tetrahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template FinishTimestepElem<Pyramid>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template FinishTimestepElem<Prism>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template FinishTimestepElem<Hexahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      this->template FinishTimestepElem<Octahedron>
        (vSubsetElemDisc, dd, si, bNonRegularGrid, vSol);
      break;
    default:
      UG_THROW("DomainDiscretization::finish_timestep_elem (instationary):"
              "Dimension "<<dim<<" (subset="<<si<<") not supported.");
    }
    }
    UG_CATCH_THROW("DomainDiscretization::finish_timestep_elem (instationary):"
            " Assembling of elements of Dimension " << dim << " in "
            " subset "<<si<< " failed.");
  }
 
}
 
template <typename TDomain, typename TAlgebra, typename TGlobAssembler>
template <typename TElem>
void DomainDiscretizationBase<TDomain, TAlgebra, TGlobAssembler>::
FinishTimestepElem(const std::vector<IElemDisc<domain_type>*>& vElemDisc,
         ConstSmartPtr<DoFDistribution> dd,
         int si, bool bNonRegularGrid,
         ConstSmartPtr<VectorTimeSeries<vector_type> > vSol)
{
  //  check if only some elements are selected
  if(m_spAssTuner->selected_elements_used())
  {
    std::vector<TElem*> vElem;
    m_spAssTuner->collect_selected_elements(vElem, dd, si);
 
    //  assembling is carried out only over those elements
    //  which are selected and in subset si
    gass_type::template FinishTimestepElem<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd, vElem.begin(), vElem.end(), si,
       bNonRegularGrid, vSol, m_spAssTuner);
  }
  else
  {
    //  general case: assembling over all elements in subset si
    gass_type::template FinishTimestepElem<TElem>
      (vElemDisc, m_spApproxSpace->domain(), dd,
        dd->template begin<TElem>(si), dd->template end<TElem>(si), si,
          bNonRegularGrid, vSol, m_spAssTuner);
  }
}
 
} // end namespace ug
 
#endif /*__H__UG__LIB_DISC__SPATIAL_DISC__DOMAIN_DISC_IMPL__*/