geometric_multigrid.cc

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//LIC// ====================================================================
//LIC// This file forms part of oomph-lib, the object-oriented, 
//LIC// multi-physics finite-element library, available 
//LIC// at http://www.oomph-lib.org.
//LIC// 
//LIC//    Version 1.0; svn revision $LastChangedRevision: 1216 $
//LIC//
//LIC// $LastChangedDate: 2016-08-06 15:23:30 +0100 (Sat, 06 Aug 2016) $
//LIC// 
//LIC// Copyright (C) 2006-2016 Matthias Heil and Andrew Hazel
//LIC// 
//LIC// This library is free software; you can redistribute it and/or
//LIC// modify it under the terms of the GNU Lesser General Public
//LIC// License as published by the Free Software Foundation; either
//LIC// version 2.1 of the License, or (at your option) any later version.
//LIC// 
//LIC// This library is distributed in the hope that it will be useful,
//LIC// but WITHOUT ANY WARRANTY; without even the implied warranty of
//LIC// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//LIC// Lesser General Public License for more details.
//LIC// 
//LIC// You should have received a copy of the GNU Lesser General Public
//LIC// License along with this library; if not, write to the Free Software
//LIC// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
//LIC// 02110-1301  USA.
//LIC// 
//LIC// The authors may be contacted at oomph-lib@maths.man.ac.uk.
//LIC// 
//LIC//====================================================================
// Include the corresponding header file
#include "geometric_multigrid.h"

namespace oomph
{
 //=========================================================================
 /// \short Given the son type of the element and the local coordinate s of
 /// a given node in the son element, return the local coordinate s in its
 /// father element. 2D case.
 //=========================================================================
 template<>
 void MGSolver<2>::level_up_local_coord_of_node(const int& son_type,
                                                Vector<double>& s)
 {         
  // If the element is unrefined between the levels the local coordinate
  // of the node in one element is the same as that in the other element
  // therefore we only need to perform calculations if the levels are
  // different (i.e. son_type is not OMEGA)
  if (son_type!=Tree::OMEGA)
  {
   // Scale the local coordinate from the range [-1,1]x[-1,1] to the range
   // [0,1]x[0,1] to match the width of the local coordinate range of the
   // fine element from the perspective of the father element. This
   // then simply requires a shift of the coordinates to match which type
   // of son element we're dealing with
   s[0]=(s[0]+1.0)/2.0;
   s[1]=(s[1]+1.0)/2.0;

   // Cases: The son_type determines how the local coordinates should be
   // shifted to give the local coordinates in the coarse mesh element
   switch(son_type)
   {
    // If we're dealing with the bottom-left element we need to shift
    // the range [0,1]x[0,1] to [-1,0]x[-1,0]
   case QuadTreeNames::SW:
    s[0]-=1;
    s[1]-=1;
    break;

    // If we're dealing with the bottom-right element we need to shift
    // the range [0,1]x[0,1] to [0,1]x[-1,0]
   case QuadTreeNames::SE:
    s[1]-=1;
    break;

    // If we're dealing with the top-right element we need to shift the
    // range [0,1]x[0,1] to [0,1]x[0,1], i.e. nothing needs to be done
   case QuadTreeNames::NE:
    break;

    // If we're dealing with the top-left element we need to shift
    // the range [0,1]x[0,1] to [-1,0]x[0,1]
   case QuadTreeNames::NW:
    s[0]-=1;
    break;
   }
  } // if son_type!=Tree::OMEGA
 } // End of level_up_local_coord_of_node
 
 //=========================================================================
 /// \short Given the son type of the element and the local coordinate s of
 /// a given node in the son element, return the local coordinate s in its
 /// father element. 3D case.
 //=========================================================================
 template<>
 void MGSolver<3>::level_up_local_coord_of_node(const int& son_type,
                                                Vector<double>& s)
 {   
  // If the element is unrefined between the levels the local coordinate
  // of the node in one element is the same as that in the other element
  // therefore we only need to perform calculations if the levels are
  // different (i.e. son_type is not OMEGA)
  if (son_type!=Tree::OMEGA)
  {
   // Scale the local coordinate from the range [-1,1]x[-1,1]x[-1,1]
   // to the range [0,1]x[0,1]x[0,1] to match the width of the local
   // coordinate range of the fine element from the perspective of
   // the father element. This then simply requires a shift of the
   // coordinates to match which type of son element we're dealing with
   s[0]=(s[0]+1.0)/2.0;
   s[1]=(s[1]+1.0)/2.0;
   s[2]=(s[2]+1.0)/2.0;

   // Cases: The son_type determines how the local coordinates should be
   // shifted to give the local coordinates in the coarse mesh element
   switch(son_type)
   {
   case OcTreeNames::LDF:
    s[0]-=1;
    s[1]-=1;
    break;

   case OcTreeNames::LDB:
    s[0]-=1;
    s[1]-=1;
    s[2]-=1;
    break;

   case OcTreeNames::LUF:
    s[0]-=1;
    break;

   case OcTreeNames::LUB:
    s[0]-=1;
    s[2]-=1;
    break;

   case OcTreeNames::RDF:
    s[1]-=1;
    break;

   case OcTreeNames::RDB:
    s[1]-=1;
    s[2]-=1;
    break;

   case OcTreeNames::RUF:
    break;

   case OcTreeNames::RUB:
    s[2]-=1;
    break;     
   }
  } // if son_type!=Tree::OMEGA   
 } // End of level_up_local_coord_of_node
} // End of namespace oomph