ElInfo2d.cc

/******************************************************************************
 *
 * AMDiS - Adaptive multidimensional simulations
 *
 * Copyright (C) 2013 Dresden University of Technology. All Rights Reserved.
 * Web: https://fusionforge.zih.tu-dresden.de/projects/amdis
 *
 * Authors:
 * Simon Vey, Thomas Witkowski, Andreas Naumann, Simon Praetorius, et al.
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *
 * This file is part of AMDiS
 *
 * See also license.opensource.txt in the distribution.
 *
 ******************************************************************************/


#include "ElInfo2d.h"
#include "BasisFunction.h"
#include "Element.h"
#include "Line.h"
#include "Triangle.h"
#include "Tetrahedron.h"
#include "FiniteElemSpace.h"
#include "Flag.h"
#include "MacroElement.h"
#include "Mesh.h"
#include "Global.h"
#include "FixVec.h"
#include "DOFVector.h"

namespace AMDiS {

  double ElInfo2d::mat_d1_left_val[3][3] = {{0.0, 1.0, 0.5},
  					    {0.0, 0.0, 0.5},
  					    {1.0, 0.0, 0.0}};
  mtl::dense2D<double> ElInfo2d::mat_d1_left(mat_d1_left_val);


  double ElInfo2d::mat_d1_right_val[3][3] = {{0.0, 0.0, 0.5},
  					     {1.0, 0.0, 0.5},
  					     {0.0, 1.0, 0.0}};
  mtl::dense2D<double> ElInfo2d::mat_d1_right(mat_d1_right_val);



  double ElInfo2d::mat_d2_left_val[6][6] = {{0.0, 1.0, 0.0, 0.375, -0.125, 0.0},
					    {0.0, 0.0, 0.0, -0.125, -0.125, 0.0},
					    {1.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					    {0.0, 0.0, 0.0, 0.0, 0.5, 0.0},
					    {0.0, 0.0, 0.0, 0.0, 0.5, 1.0},
					    {0.0, 0.0, 1.0, 0.75, 0.25, 0.0}};
  mtl::dense2D<double> ElInfo2d::mat_d2_left(mat_d2_left_val);

  double ElInfo2d::mat_d2_right_val[6][6] = {{0.0, 0.0, 0.0, -0.125, -0.125, 0.0},
					     {1.0, 0.0, 0.0, -0.125, 0.375, 0.0},
					     {0.0, 1.0, 0.0, 0.0, 0.0, 0.0},
					     {0.0, 0.0, 0.0, 0.5, 0.0, 1.0},
					     {0.0, 0.0, 0.0, 0.5, 0.0, 0.0},
					     {0.0, 0.0, 1.0, 0.25, 0.75, 0.0}};
  mtl::dense2D<double> ElInfo2d::mat_d2_right(mat_d2_right_val);



  double ElInfo2d::mat_d3_left_val[10][10] = {{0.0,  1.0, -6.25e-02,  3.125e-01,  0.0,  0.0,  6.25e-02,  0.0,  0.0, -6.25e-02},
					      {0.0,  0.0, -6.25e-02,  6.25e-02,  0.0,  0.0,  6.25e-02,  0.0,  0.0, 6.25e-02},
					      {1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -2.5e-01,  0.0,  0.0, -0.125},
					      {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0},
					      {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.5, 1.0, 0.0, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -2.5e-01,  0.0,  1.0, 0.375},
					      {0.0,  0.0,  5.625e-01,  9.375e-01,  1.0,  0.0, -6.25e-02,  0.0,  0.0, 1.875e-01},
					      {0.0,  0.0,  5.625e-01, -3.125e-01,  0.0,  0.0, -6.25e-02,  0.0,  0.0, -1.875e-01},
					      {0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.5, 0.0, 0.0, 7.5e-01}};
  mtl::dense2D<double> ElInfo2d::mat_d3_left(mat_d3_left_val);

  double ElInfo2d::mat_d3_right_val[10][10] = {{0.0,  0.0, -6.25e-02,  6.25e-02,  0.0,  0.0,  6.25e-02,  0.0,  0.0, 6.25e-02},
					      {1.0,  0.0, -6.25e-02,  6.25e-02,  0.0,  0.0,  3.125e-01,  0.0,  0.0, -6.25e-02},
					      {0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					      {0.0,  0.0,  0.0, -2.5e-01,  0.0,  0.0,  0.0,  1.0,  0.0, 0.375},
					      {0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0},
					      {0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					      {0.0,  0.0,  0.0, -2.5e-01,  0.0,  0.0,  0.0,  0.0,  0.0, -0.125},
					      {0.0,  0.0,  5.625e-01, -6.25e-02,  0.0,  0.0, -3.125e-01,  0.0,  0.0, -1.875e-01},
					      {0.0,  0.0,  5.625e-01, -6.25e-02,  0.0,  1.0,  9.375e-01,  0.0,  0.0, 1.875e-01},
					      {0.0, 0.0, 0.0, 0.5, 1.0, 0.0, 0.0, 0.0, 0.0, 7.5e-01}};
  mtl::dense2D<double> ElInfo2d::mat_d3_right(mat_d3_right_val);



  double ElInfo2d::mat_d4_left_val[15][15] = {{0.0,  1.0,  0.0,  2.734375e-01,  0.0, -3.906250e-02,  2.343750e-02,  0.0, -3.906250e-02,  0.0,  0.0,  0.0,  2.343750e-02, -3.906250e-02, 0.0},
					      {0.0,  0.0,  0.0, -3.906250e-02,  0.0,  2.343750e-02,  2.343750e-02,  0.0, -3.906250e-02,  0.0,  0.0,  0.0, -3.906250e-02, -3.906250e-02, 0.0},
					      {1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -6.25e-02,  0.0,  1.875e-01,  0.0,  0.0,  0.0,  0.125,  6.25e-02, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -0.375,  0.0,  0.0,  0.0, -0.125,  0.0, 0.0},
					      {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					      {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.5, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -0.375,  0.0,  1.0,  0.0,  0.375,  0.0, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -6.25e-02,  0.0,  1.875e-01,  0.0,  0.0,  1.0, -0.125,  3.125e-01, 0.0},
					      {0.0,  0.0,  0.0,  1.093750e+00,  1.0,  4.687500e-01, -9.375e-02,  0.0,  3.125e-02,  0.0,  0.0,  0.0, -3.125e-02,  1.562500e-01, 0.0},
					      {0.0,  0.0,  1.0, -5.468750e-01,  0.0,  7.031250e-01,  1.406250e-01,  0.0,  1.562500e-02,  0.0,  0.0,  0.0, -4.687500e-02, -2.343750e-01, 0.0},
					      {0.0,  0.0,  0.0,  2.187500e-01,  0.0, -1.562500e-01, -9.375e-02,  0.0,  3.125e-02,  0.0,  0.0,  0.0,  9.375e-02,  1.562500e-01, 0.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  5.625e-01,  0.0, -1.875e-01,  0.0,  0.0,  0.0,  0.375,  9.375e-01, 1.0},
					      {0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  5.625e-01,  0.0, -1.875e-01,  0.0,  0.0,  0.0, -0.375, -3.125e-01, 0.0},
					      {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 7.5e-01, 0.0, 0.0, 0.0, 7.5e-01, 0.0, 0.0}};
  mtl::dense2D<double> ElInfo2d::mat_d4_left(mat_d4_left_val);

  double ElInfo2d::mat_d4_right_val[15][15] = {{0.0,  0.0,  0.0, -3.906250e-02,  0.0,  2.343750e-02,  2.343750e-02,  0.0, -3.906250e-02,  0.0,  0.0,  0.0, -3.906250e-02, -3.906250e-02, 0.0},
						{1.0,  0.0,  0.0, -3.906250e-02,  0.0,  2.343750e-02, -3.906250e-02,  0.0,  2.734375e-01,  0.0,  0.0,  0.0, -3.906250e-02,  2.343750e-02, 0.0},
						{0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
						{0.0,  0.0,  0.0,  1.875e-01,  0.0, -6.25e-02,  0.0,  0.0,  0.0,  1.0,  0.0,  0.0,  3.125e-01, -0.125, 0.0},
						{0.0,  0.0,  0.0, -0.375,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  1.0,  0.0,  0.0,  0.375, 0.0},
						{0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0},
						{0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
						{0.0,  0.0,  0.0, -0.375,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -0.125, 0.0},
						{0.0,  0.0,  0.0,  1.875e-01,  0.0, -6.25e-02,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  6.25e-02,  0.125, 0.0},
						{0.0,  0.0,  0.0,  3.125e-02,  0.0, -9.375e-02, -1.562500e-01,  0.0,  2.187500e-01,  0.0,  0.0,  0.0,  1.562500e-01,  9.375e-02, 0.0},
						{0.0,  0.0,  1.0,  1.562500e-02,  0.0,  1.406250e-01,  7.031250e-01,  0.0, -5.468750e-01,  0.0,  0.0,  0.0, -2.343750e-01, -4.687500e-02, 0.0},
						{0.0,  0.0,  0.0,  3.125e-02,  0.0, -9.375e-02,  4.687500e-01,  1.0,  1.093750e+00,  0.0,  0.0,  0.0,  1.562500e-01, -3.125e-02, 0.0},
						{0.0,  0.0,  0.0, -1.875e-01,  0.0,  5.625e-01,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -3.125e-01, -0.375, 0.0},
						{0.0,  0.0,  0.0, -1.875e-01,  0.0,  5.625e-01,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  9.375e-01,  0.375, 1.0},
						{0.0, 0.0, 0.0, 7.5e-01, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 7.5e-01, 0.0}};
  mtl::dense2D<double> ElInfo2d::mat_d4_right(mat_d4_right_val);


  ElInfo2d::ElInfo2d(Mesh *aMesh)
    : ElInfo(aMesh)
  {}


  ElInfo2d::~ElInfo2d()
  {}


  void ElInfo2d::fillMacroInfo(const MacroElement * mel)
  {
    FUNCNAME("ElInfo::fillMacroInfo()");

    macroElement = const_cast<MacroElement*>(mel);
    element = const_cast<Element*>(mel->getElement());
    parent = NULL;
    level = 0;

    if (fillFlag.isSet(Mesh::FILL_COORDS) ||
	fillFlag.isSet(Mesh::FILL_DET)    ||
	fillFlag.isSet(Mesh::FILL_GRD_LAMBDA)) {

      int vertices = mesh->getGeo(VERTEX);
      for (int i = 0; i < vertices; i++)
	coord[i] = mel->coord[i];
    }

    int neighbours = mesh->getGeo(NEIGH);

    if (fillFlag.isSet(Mesh::FILL_OPP_COORDS) ||
	fillFlag.isSet(Mesh::FILL_NEIGH)) {

      bool fill_opp_coords = (fillFlag.isSet(Mesh::FILL_OPP_COORDS));

      for (int i = 0; i < neighbours; i++) {
	MacroElement *macroNeighbour = mel->getNeighbour(i);

	if (macroNeighbour) {
	  neighbour[i] = macroNeighbour->getElement();
	  Element *nb = const_cast<Element*>(neighbour[i]);

	  int edgeNo = oppVertex[i] = mel->getOppVertex(i);


	  if (nb->getFirstChild() && edgeNo != 2) {
            /*
	    * Search for the next neighbour. In many cases, the neighbour element
	    * may be refinemed in a way, such that there is no new vertex on the
	    * common edge. This situation is shown in the following picture:
	    *
	    *               /|\
	    *              / | \
	    *             /  |  \
	    *            /\  |   \
	    *           /  \ |    \
	    *          /    \|     \
	    *          -------------
	    *
	    *            nb     el
	    *
	    * Note that we know (because of the last if statement), that the
	    * neighbour element has children and the common edge is not the
	    * refinement edge, which has always the number 2, of our element.
	    */

	    if (edgeNo == 0) {
	      /*
	      * The situation is as follows:
	      *
	      *          -------
	      *          \    /|\
	      *           \  / | \
	      *            \/  |  \
	      *             \  |   \
	      *              \ |    \
	      *               \|     \
	      *                -------
	      *
	      *            nb     el
              *
	      * That means, the edge 0 of the same level neighbour is the common
	      * edge, i.e., the direct neighbour is the second child of the same
	      * level neighbour.
	      */
	      nb = neighbour[i] = nb->getSecondChild();
	    } else {
	      // The situation is as shown in the picture above. So the next
	      // neighbour is the first child of the same level neighbour element.
	      nb = neighbour[i] = nb->getFirstChild();
	    }

	    // In both cases the opp vertex number is 2, as one can see in the
	    // pictures above.
	    oppVertex[i] = 2;

	    if (fill_opp_coords) {
	      if (nb->isNewCoordSet()) {
		oppCoord[i] = *(nb->getNewCoord());
	      } else {
		// In both cases, that are shown in the pictures above, the opp
		// vertex of the neighbour edge is the midpoint of the vertex 0
		// and vertex 1 of the same level neighbour element.
		oppCoord[i] = (macroNeighbour->coord[0] +
				macroNeighbour->coord[1]) * 0.5;
	      }

	      switch (i) {
	      case 0:
		// The common edge is the edge 0 of this element.

		switch (edgeNo) {
		case 1:
		  neighbourCoord[i][0] = macroNeighbour->coord[2];
		  neighbourCoord[i][1] = macroNeighbour->coord[0];
		  break;
		case 0:
		  neighbourCoord[i][0] = macroNeighbour->coord[1];
		  neighbourCoord[i][1] = macroNeighbour->coord[2];
		  break;
		default:
		  ERROR_EXIT("Should not happen!\n");
		}

		neighbourCoord[i][2] = oppCoord[i];
		break;

	      case 1:
		// The common edge is the edge 1 of this element.
		switch (edgeNo) {
		case 0:
		  neighbourCoord[i][0] = macroNeighbour->coord[1];
		  neighbourCoord[i][1] = macroNeighbour->coord[2];
		  break;
		case 1:
		  neighbourCoord[i][0] = macroNeighbour->coord[2];
		  neighbourCoord[i][1] = macroNeighbour->coord[0];
		  break;
		default:
		  ERROR_EXIT("Should not happen!\n");
		}

		neighbourCoord[i][2] = oppCoord[i];
		break;

	      case 2:
		if (*(macroNeighbour->getElement()->getDof(2)) == *(element->getDof(0))) {
		  neighbourCoord[i][0] = macroNeighbour->coord[2];
		  neighbourCoord[i][1] = macroNeighbour->coord[1];
		} else if (*(macroNeighbour->getElement()->getDof(2)) == *(element->getDof(1))) {
		  neighbourCoord[i][0] = macroNeighbour->coord[0];
		  neighbourCoord[i][1] = macroNeighbour->coord[2];
		} else {
		  ERROR_EXIT("Should not happen! Non-conforming AMDiS-mesh? Periodic mesh with corrected index-circles?\n");
		}

		// I've deleted here some code, be I think that this case is not
		// possible. If an error occurs in this line, please check AMDiS
		// revision <= 476 at the same position.
		//		ERROR_EXIT("Should not happen!\n");

		break;

	      default:
		std::cout << "------------- Error --------------" << std::endl;
		std::cout << "  Neighbour counter = " << i << "\n";
		std::cout << "  Element index     = " << element->getIndex() << "\n\n";
		for (int j = 0; j < neighbours; j++) {
		  if (mel->getNeighbour(j)) {
		    std::cout << "  Neighbour " << j << ": "
			      << mel->getNeighbour(j)->getElement()->getIndex()
			      << std::endl;
		  } else {
		    std::cout << "  Neighbour " << j << ": not existing" << std::endl;
		  }
		  std::cout << "  OppVertex " << j << ": "
			    << static_cast<int>(mel->getOppVertex(j))
			    << std::endl << std::endl;
		}
		ERROR_EXIT("should not happen!\n");
		break;
	      }
	    }
	  } else {

	    // In this case, we know that the common edge is the refinement edge.
	    // This makes everything much more simpler, because we know that the
	    // next neighbour is equal to the samel level neighbour. If the same
	    // level neighbour would be refinement, also this element must to be
	    // refinement, because they share the refinement edge.

	    if (fill_opp_coords) {
	      oppCoord[i] = macroNeighbour->coord[edgeNo];
	      neighbourCoord[i] = macroNeighbour->coord;
	    }
	  }
	} else {
	  neighbour[i] = NULL;
        }
      }
    }

    if (fillFlag.isSet(Mesh::FILL_BOUND)) {
      for (int i = 0; i < element->getGeo(BOUNDARY); i++)
	boundary[i] = mel->getBoundary(i);
      for (int i = 0; i < element->getGeo(PROJECTION); i++)
	projection[i] = mel->getProjection(i);
    }
  }


  /****************************************************************************/
  /*   fill ElInfo structure for one child of an element   		    */
  /****************************************************************************/

  void ElInfo2d::fillElInfo(int ichild, const ElInfo *elInfoOld)
  {
    FUNCNAME("ElInfo::fillElInfo()");

    Element *elem = elInfoOld->element;
    Flag fill_flag = elInfoOld->fillFlag;

    TEST_EXIT_DBG(elem->getFirstChild())("no children?\n");
    element = const_cast<Element*>((ichild == 0) ?
				    elem->getFirstChild() :
				    elem->getSecondChild());
    TEST_EXIT_DBG(element)("missing child %d?\n", ichild);

    macroElement  = elInfoOld->macroElement;
    fillFlag = fill_flag;
    parent = elem;
    level = elInfoOld->level + 1;
    iChild = ichild;

    if (fillFlag.isSet(Mesh::FILL_COORDS) ||
	fillFlag.isSet(Mesh::FILL_DET)    ||
	fillFlag.isSet(Mesh::FILL_GRD_LAMBDA)) {

      if (elem->isNewCoordSet())
	coord[2] = *(elem->getNewCoord());
      else
	coord[2].setMidpoint(elInfoOld->coord[0], elInfoOld->coord[1]);

      if (ichild == 0) {
	coord[0] = elInfoOld->coord[2];
	coord[1] = elInfoOld->coord[0];
      } else {
	coord[0] = elInfoOld->coord[1];
	coord[1] = elInfoOld->coord[2];
      }
    }

    bool fill_opp_coords = (fill_flag.isSet(Mesh::FILL_OPP_COORDS));

    if (fill_flag.isSet(Mesh::FILL_NEIGH) || fill_opp_coords) {
      if (ichild == 0) {
	// Calculation of the neighbour 2, its oppCoords and the
	// cooresponding oppVertex.

	neighbour[2] = elInfoOld->neighbour[1];
	oppVertex[2] = elInfoOld->oppVertex[1];

	if (neighbour[2] && fill_opp_coords) {
	  oppCoord[2] = elInfoOld->oppCoord[1];
	  neighbourCoord[2] = elInfoOld->neighbourCoord[1];
	}


	// Calculation of the neighbour 1, its oppCoords and the
	// cooresponding oppVertex.

	if (elem->getFirstChild()  &&
	    elem->getSecondChild()->getFirstChild()  &&
	    elem->getSecondChild()->getFirstChild()) {

	  neighbour[1] = elem->getSecondChild()->getSecondChild();
	  oppVertex[1] = 2;

	  if (fill_opp_coords) {
            if (elem->getSecondChild()->isNewCoordSet())
	      oppCoord[1] = *(elem->getSecondChild()->getNewCoord());
	    else
	      oppCoord[1].setMidpoint(elInfoOld->coord[1], elInfoOld->coord[2]);

	    neighbourCoord[1][0] = coord[0];
	    neighbourCoord[1][1] = coord[2];
	    neighbourCoord[1][2] = oppCoord[1];
	  }
	} else {
	  neighbour[1] = elem->getSecondChild();
	  oppVertex[1] = 0;

	  if (fill_opp_coords) {
	    oppCoord[1] = elInfoOld->coord[1];

	    neighbourCoord[1][0] = elInfoOld->coord[1];
	    neighbourCoord[1][1] = elInfoOld->coord[2];
	    neighbourCoord[1][2] = coord[2];
	  }
	}


	// Calculation of the neighbour 0, its oppCoords and the
	// cooresponding oppVertex.

	Element *nb = elInfoOld->neighbour[2];
	if (nb) {
	  TEST_EXIT_DBG(elInfoOld->oppVertex[2] == 2)
	    ("Fill child %d of element %d (mel %d): Invalid neighbour %d!\n",
	     ichild,
	     elInfoOld->getElement()->getIndex(),
	     elInfoOld->getMacroElement()->getIndex(),
	     nb->getIndex());

	  TEST_EXIT_DBG(nb->getFirstChild())
	    ("Missing first child in element %d!\n", nb->getIndex());
	  TEST_EXIT_DBG(nb->getSecondChild())
	    ("Missing second child in element %d!\n", nb->getIndex());

	  nb = nb->getSecondChild();

	  if (nb->getFirstChild()) {
	    oppVertex[0] = 2;

	    if (fill_opp_coords) {
	      if (nb->isNewCoordSet()) {
		oppCoord[0] = *(nb->getNewCoord());
	      } else {
		oppCoord[0].setMidpoint(elInfoOld->neighbourCoord[2][1],
					 elInfoOld->neighbourCoord[2][2]);
	      }

	      neighbourCoord[0][0].setMidpoint(elInfoOld->neighbourCoord[2][0],
						elInfoOld->neighbourCoord[2][1]);
	      neighbourCoord[0][1] = elInfoOld->neighbourCoord[2][1];
	      neighbourCoord[0][2] = oppCoord[0];
	    }

	    nb = nb->getFirstChild();
	  } else {
	    oppVertex[0] = 1;

	    if (fill_opp_coords) {
	      oppCoord[0] = elInfoOld->oppCoord[2];

	      neighbourCoord[0][0] = elInfoOld->neighbourCoord[2][0];
	      neighbourCoord[0][1] = elInfoOld->neighbourCoord[2][2];
	      neighbourCoord[0][2].setMidpoint(elInfoOld->neighbourCoord[2][0],
						elInfoOld->neighbourCoord[2][1]);
	    }
	  }
	}

	neighbour[0] = nb;
      } else {   /* ichild == 1 */
	// Calculation of the neighbour 2, its oppCoords and the
	// cooresponding oppVertex.

	neighbour[2] = elInfoOld->neighbour[0];
	oppVertex[2] = elInfoOld->oppVertex[0];

	if (neighbour[2] && fill_opp_coords) {
	  oppCoord[2] = elInfoOld->oppCoord[0];
	  neighbourCoord[2] = elInfoOld->neighbourCoord[0];
	}


	// Calculation of the neighbour 0, its oppCoords and the
	// cooresponding oppVertex.

	if (elem->getFirstChild()->getFirstChild()) {
	  neighbour[0] = elem->getFirstChild()->getFirstChild();
	  oppVertex[0] = 2;

	  if (fill_opp_coords) {
            if (elem->getFirstChild()->isNewCoordSet()) {
	      oppCoord[0] = *(elem->getFirstChild()->getNewCoord());
	    } else {
	      oppCoord[0].setMidpoint(elInfoOld->coord[0],
				       elInfoOld->coord[2]);
	    }

	    neighbourCoord[0][0] = coord[2];
	    neighbourCoord[0][1] = coord[1];
	    neighbourCoord[0][2] = oppCoord[0];
	  }
	} else {
	  neighbour[0] = elem->getFirstChild();
	  oppVertex[0] = 1;

	  if (fill_opp_coords) {
	    oppCoord[0] = elInfoOld->coord[0];

	    neighbourCoord[0][0] = elInfoOld->coord[2];
	    neighbourCoord[0][1] = elInfoOld->coord[0];
	    neighbourCoord[0][2] = coord[2];
	  }
	}

	// Calculation of the neighbour 1, its oppCoords and the
	// cooresponding oppVertex.

	Element *nb = elInfoOld->neighbour[2];
	if (nb) {
	  TEST(elInfoOld->oppVertex[2] == 2)("invalid neighbour\n");
	  TEST((nb = nb->getFirstChild()))("missing child?\n");

	  if (nb->getFirstChild()) {
	    oppVertex[1] = 2;

	    if (fill_opp_coords) {
	      if (nb->isNewCoordSet()) {
		oppCoord[1] = *(nb->getNewCoord());
	      } else {
		oppCoord[1].setMidpoint(elInfoOld->neighbourCoord[2][0],
					 elInfoOld->neighbourCoord[2][2]);
	      }

	      neighbourCoord[1][0] = elInfoOld->neighbourCoord[2][0];
	      neighbourCoord[1][1].setMidpoint(elInfoOld->neighbourCoord[2][0],
					       elInfoOld->neighbourCoord[2][1]);
	      neighbourCoord[1][2] = oppCoord[1];
	    }
	    nb = nb->getSecondChild();

	  } else {
	    oppVertex[1] = 0;

	    if (fill_opp_coords) {
	      oppCoord[1] = elInfoOld->oppCoord[2];

	      neighbourCoord[1][0] = elInfoOld->neighbourCoord[2][2];
	      neighbourCoord[1][1] = elInfoOld->neighbourCoord[2][0];
	      neighbourCoord[1][2].setMidpoint(elInfoOld->neighbourCoord[2][0],
					       elInfoOld->neighbourCoord[2][1]);
	    }
	  }
	}
	neighbour[1] = nb;
      } // if (ichild == 0) {} else
    } // if (fill_flag.isSet(Mesh::FILL_NEIGH) || fillFlag.isSet(Mesh::FILL_OPP_COORDS))


    if (fill_flag.isSet(Mesh::FILL_BOUND)) {
      if (elInfoOld->getBoundary(2))
	boundary[5] = elInfoOld->getBoundary(2);
      else
	boundary[5] = INTERIOR;

      if (ichild == 0) {
	boundary[3] = elInfoOld->getBoundary(5);
	boundary[4] = elInfoOld->getBoundary(3);
	boundary[0] = elInfoOld->getBoundary(2);
	boundary[1] = INTERIOR;
	boundary[2] = elInfoOld->getBoundary(1);
      } else {
	boundary[3] = elInfoOld->getBoundary(4);
	boundary[4] = elInfoOld->getBoundary(5);
	boundary[0] = INTERIOR;
	boundary[1] = elInfoOld->getBoundary(2);
	boundary[2] = elInfoOld->getBoundary(0);
      }

      if (elInfoOld->getProjection(0) &&
	  elInfoOld->getProjection(0)->getType() == VOLUME_PROJECTION) {

	projection[0] = elInfoOld->getProjection(0);
      } else { // boundary projection
	if (ichild == 0) {
	  projection[0] = elInfoOld->getProjection(2);
	  projection[1] = NULL;
	  projection[2] = elInfoOld->getProjection(1);
	} else {
	  projection[0] = NULL;
	  projection[1] = elInfoOld->getProjection(2);
	  projection[2] = elInfoOld->getProjection(0);
	}
      }
    }
  }

  double ElInfo2d::calcGrdLambda(DimVec<WorldVector<double> >& grd)
  {
    FUNCNAME("ElInfo2d::calcGrdLambda()");

    testFlag(Mesh::FILL_COORDS);

    double adet = 0.0;
    int dim = mesh->getDim();

    for (int i = 0; i < dimOfWorld; i++) {
      e1[i] = coord[1][i] - coord[0][i];
      e2[i] = coord[2][i] - coord[0][i];
    }

    if (dimOfWorld == 2) {
      double sdet = e1[0] * e2[1] - e1[1] * e2[0];
      adet = abs(sdet);

      if (adet < 1.0E-25) {
	MSG("abs(det) = %f\n", adet);
	for (int i = 0; i <= dim; i++)
	  grd[i].set(0.0);
      } else {
	double det1 = 1.0 / sdet;

	grd[1][0] = e2[1] * det1;  // a11: (a_ij) = A^{-T}
	grd[1][1] = -e2[0] * det1; // a21
	grd[2][0] = -e1[1] * det1; // a12
	grd[2][1] = e1[0] * det1;  // a22
	grd[0][0] = -grd[1][0] - grd[2][0];
	grd[0][1] = -grd[1][1] - grd[2][1];
      }
    } else {
      vectorProduct(e1, e2, normal);

      adet = norm(normal);

      if (adet < 1.0E-15) {
	MSG("abs(det) = %lf\n", adet);
	for (int i = 0; i <= dim; i++)
	  for (int j = 0; j < dimOfWorld; j++)
	    grd[i][j] = 0.0;
      } else {
	vectorProduct(e2, normal, grd[1]);
	vectorProduct(normal, e1, grd[2]);

	double adet2 = 1.0 / (adet * adet);

	for (int i = 0; i < dimOfWorld; i++) {
	  grd[1][i] *= adet2;
	  grd[2][i] *= adet2;
	}

	grd[0][0] = -grd[1][0] - grd[2][0];
	grd[0][1] = -grd[1][1] - grd[2][1];
	grd[0][2] = -grd[1][2] - grd[2][2];
      }
    }

    return adet;
  }


  int ElInfo2d::worldToCoord(const WorldVector<double>& xy,
				   DimVec<double>* lambda) const
  {
    FUNCNAME("ElInfo::worldToCoord()");

    TEST_EXIT_DBG(lambda)("lambda must not be NULL\n");

    DimVec<WorldVector<double> > edge(mesh->getDim(), NO_INIT);
    WorldVector<double> x;

    int dim = mesh->getDim();

    for (int j = 0; j < dimOfWorld; j++) {
      double x0 = coord[dim][j];
      x[j] = xy[j] - x0;
      for (int i = 0; i < dim; i++)
	edge[i][j] = coord[i][j] - x0;
    }

    double det  = edge[0][0] * edge[1][1] - edge[0][1] * edge[1][0];
    double det0 =       x[0] * edge[1][1] -       x[1] * edge[1][0];
    double det1 = edge[0][0] * x[1]       - edge[0][1] * x[0];

    if (abs(det) < DBL_TOL) {
      ERROR("det = %le; abort\n", det);
      for (int i = 0; i <= dim; i++)
	(*lambda)[i] = 1.0 / dim;
      return 0;
    }

    (*lambda)[0] = det0 / det;
    (*lambda)[1] = det1 / det;
    (*lambda)[2] = 1.0 - (*lambda)[0] - (*lambda)[1];

    int k = -1;
    double lmin = 0.0;
    for (int i = 0; i <= dim; i++) {
      if ((*lambda)[i] < -1.e-5) {
	if ((*lambda)[i] < lmin) {
	  k = i;
	  lmin = (*lambda)[i];
	}
      }
    }

    return k;
  }


  double ElInfo2d::getNormal(int side, WorldVector<double> &normal) const
  {
    FUNCNAME_DBG("ElInfo::getNormal()");

    int i0 = (side + 1) % 3;
    int i1 = (side + 2) % 3;

    if (dimOfWorld == 2){
      normal[0] = coord[i1][1] - coord[i0][1];
      normal[1] = coord[i0][0] - coord[i1][0];
    } else { // dow == 3
      WorldVector<double> e0, e1, e2, elementNormal;

      e0 = coord[i1];
      e0 -= coord[i0];
      e1 = coord[i1];
      e1 -= coord[side];
      e2 = coord[i0];
      e2 -= coord[side];

      vectorProduct(e1, e2, elementNormal);
      vectorProduct(elementNormal, e0, normal);
    }

    double detn = norm(&normal);

    TEST_EXIT_DBG(detn > 1.e-30)("det = 0 on face %d\n", side);

    normal *= 1.0 / detn;

    return detn;
  }


  /****************************************************************************/
  /*  calculate the normal of the element for dim of world = dim + 1          */
  /*  return the absulute value of the determinant from the                   */
  /*  transformation to the reference element                                 */
  /****************************************************************************/
  double ElInfo2d::getElementNormal(WorldVector<double> &elementNormal) const
  {
    FUNCNAME_DBG("ElInfo::getElementNormal()");

    TEST_EXIT_DBG(dimOfWorld == 3)
      (" element normal only well defined for  DIM_OF_WORLD = DIM + 1 !!");

    WorldVector<double> e0 = coord[1] - coord[0];
    WorldVector<double> e1 = coord[2] - coord[0];

    vectorProduct(e0, e1, elementNormal);

    double detn = norm(&elementNormal);

    TEST_EXIT_DBG(detn > 1.e-30)("det = 0");

    elementNormal *= 1.0 / detn;

    return detn;
  }