Home
Publications
Presentations
Support
Download
Examples
Developers
Class Docs
Namespaces
Classes
Files
Mailing Lists
Gallery
Wiki

fe_clough.C

Go to the documentation of this file.

// The libMesh Finite Element Library.
// Copyright (C) 2002-2012 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.

// This library 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.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



// Local includes
#include "libmesh/elem.h"
#include "libmesh/fe.h"
#include "libmesh/fe_interface.h"


namespace libMesh
{

  // ------------------------------------------------------------
  // Clough-specific implementations

  // Anonymous namespace for local helper functions
  namespace {

    void clough_nodal_soln(const Elem* elem,
                           const Order order,
                           const std::vector<Number>& elem_soln,
                           std::vector<Number>&       nodal_soln,
                           unsigned Dim)
    {
      const unsigned int n_nodes = elem->n_nodes();

      const ElemType elem_type = elem->type();

      nodal_soln.resize(n_nodes);

      const Order totalorder = static_cast<Order>(order + elem->p_level());

      // FEType object to be passed to various FEInterface functions below.
      FEType fe_type(totalorder, CLOUGH);

      switch (totalorder)
        {
          // Piecewise cubic shape functions with linear flux edges
        case SECOND:
          // Piecewise cubic shape functions
        case THIRD:
          {

            const unsigned int n_sf =
              // FE<Dim,T>::n_shape_functions(elem_type, totalorder);
              FEInterface::n_shape_functions(Dim, fe_type, elem_type);

            std::vector<Point> refspace_nodes;
            FEBase::get_refspace_nodes(elem_type,refspace_nodes);
            libmesh_assert_equal_to (refspace_nodes.size(), n_nodes);

            for (unsigned int n=0; n<n_nodes; n++)
              {
                libmesh_assert_equal_to (elem_soln.size(), n_sf);

                // Zero before summation
                nodal_soln[n] = 0;

                // u_i = Sum (alpha_i phi_i)
                for (unsigned int i=0; i<n_sf; i++)
                  nodal_soln[n] += elem_soln[i] *
                    // FE<Dim,T>::shape(elem, order, i, mapped_point);
                    FEInterface::shape(Dim, fe_type, elem, i, refspace_nodes[n]);
              }

            return;
          }

        default:
          {
            libmesh_error();
          }
        }
    } // clough_nodal_soln()




    unsigned int clough_n_dofs(const ElemType t, const Order o)
    {
      switch (o)
        {
          // Piecewise cubic shape functions with linear flux edges
        case SECOND:
          {
            switch (t)
              {
              case TRI6:
                return 9;

              default:
                {
#ifdef DEBUG
                  libMesh::err << "ERROR: Bad ElemType = " << t
                               << " for " << o << "th order approximation!"
                               << std::endl;
#endif
                  libmesh_error();
                }
              }
          }
          // Piecewise cubic Clough-Tocher element
        case THIRD:
          {
            switch (t)
              {
              case TRI6:
                return 12;

              default:
                {
#ifdef DEBUG
                  libMesh::err << "ERROR: Bad ElemType = " << t
                               << " for " << o << "th order approximation!"
                               << std::endl;
#endif
                  libmesh_error();
                }
              }
          }

        default:
          {
            libmesh_error();
          }
        }

      libmesh_error();
      return 0;
    } // clough_n_dofs()





    unsigned int clough_n_dofs_at_node(const ElemType t,
                                       const Order o,
                                       const unsigned int n)
    {
      switch (o)
        {
          // Piecewise cubic shape functions with linear flux edges
        case SECOND:
          {
            switch (t)
              {
                // The 2D Clough-Tocher defined on a 6-noded triangle
              case TRI6:
                {
                  switch (n)
                    {
                    case 0:
                    case 1:
                    case 2:
                      return 3;

                    case 3:
                    case 4:
                    case 5:
                      return 0;

                    default:
                      libmesh_error();
                    }
                }

              default:
                {
#ifdef DEBUG
                  libMesh::err << "ERROR: Bad ElemType = " << t
                               << " for " << o << "th order approximation!"
                               << std::endl;
#endif
                  libmesh_error();
                }

              }
          }
          // The third-order clough shape functions
        case THIRD:
          {
            switch (t)
              {
                // The 2D Clough-Tocher defined on a 6-noded triangle
              case TRI6:
                {
                  switch (n)
                    {
                    case 0:
                    case 1:
                    case 2:
                      return 3;

                    case 3:
                    case 4:
                    case 5:
                      return 1;

                    default:
                      libmesh_error();
                    }
                }

              default:
                {
#ifdef DEBUG
                  libMesh::err << "ERROR: Bad ElemType = " << t
                               << " for " << o << "th order approximation!"
                               << std::endl;
#endif
                  libmesh_error();
                }

              }
          }
        default:
          {
            libmesh_error();
          }
        }

      libmesh_error();

      return 0;
    } // clough_n_dofs_at_node()




    unsigned int clough_n_dofs_per_elem(const ElemType t, const Order o)
    {
      switch (o)
        {
          // Piecewise cubic shape functions with linear flux edges
        case SECOND:
          // The third-order Clough-Tocher shape functions
        case THIRD:
          {
            switch (t)
              {
                // The 2D clough defined on a 6-noded triangle
              case TRI6:
                return 0;

              default:
                {
#ifdef DEBUG
                  libMesh::err << "ERROR: Bad ElemType = " << t
                               << " for " << o << "th order approximation!"
                               << std::endl;
#endif
                  libmesh_error();
                }

              }
          }
          // Otherwise no DOFS per element
        default:
          libmesh_error();
          return 0;
        }
    } // clough_n_dofs_per_elem()

  } // anonymous




  // Do full-specialization of nodal_soln() function for every
  // dimension, instead of explicit instantiation at the end of this
  // file.
  // This could be macro-ified so that it fits on one line...
  template <>
  void FE<0,CLOUGH>::nodal_soln(const Elem* elem,
                                  const Order order,
                                  const std::vector<Number>& elem_soln,
                                  std::vector<Number>& nodal_soln)
  { clough_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/0); }

  template <>
  void FE<1,CLOUGH>::nodal_soln(const Elem* elem,
                                  const Order order,
                                  const std::vector<Number>& elem_soln,
                                  std::vector<Number>& nodal_soln)
  { clough_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/1); }

  template <>
  void FE<2,CLOUGH>::nodal_soln(const Elem* elem,
                                  const Order order,
                                  const std::vector<Number>& elem_soln,
                                  std::vector<Number>& nodal_soln)
  { clough_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/2); }

  template <>
  void FE<3,CLOUGH>::nodal_soln(const Elem* elem,
                                  const Order order,
                                  const std::vector<Number>& elem_soln,
                                  std::vector<Number>& nodal_soln)
  { clough_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/3); }


  // Full specialization of n_dofs() function for every dimension
  template <> unsigned int FE<0,CLOUGH>::n_dofs(const ElemType t, const Order o) { return clough_n_dofs(t, o); }
  template <> unsigned int FE<1,CLOUGH>::n_dofs(const ElemType t, const Order o) { return clough_n_dofs(t, o); }
  template <> unsigned int FE<2,CLOUGH>::n_dofs(const ElemType t, const Order o) { return clough_n_dofs(t, o); }
  template <> unsigned int FE<3,CLOUGH>::n_dofs(const ElemType t, const Order o) { return clough_n_dofs(t, o); }


  // Full specialization of n_dofs_at_node() function for every dimension.
  template <> unsigned int FE<0,CLOUGH>::n_dofs_at_node(const ElemType t, const Order o, const unsigned int n) { return clough_n_dofs_at_node(t, o, n); }
  template <> unsigned int FE<1,CLOUGH>::n_dofs_at_node(const ElemType t, const Order o, const unsigned int n) { return clough_n_dofs_at_node(t, o, n); }
  template <> unsigned int FE<2,CLOUGH>::n_dofs_at_node(const ElemType t, const Order o, const unsigned int n) { return clough_n_dofs_at_node(t, o, n); }
  template <> unsigned int FE<3,CLOUGH>::n_dofs_at_node(const ElemType t, const Order o, const unsigned int n) { return clough_n_dofs_at_node(t, o, n); }

  // Full specialization of n_dofs_per_elem() function for every dimension.
  template <> unsigned int FE<0,CLOUGH>::n_dofs_per_elem(const ElemType t, const Order o) { return clough_n_dofs_per_elem(t, o); }
  template <> unsigned int FE<1,CLOUGH>::n_dofs_per_elem(const ElemType t, const Order o) { return clough_n_dofs_per_elem(t, o); }
  template <> unsigned int FE<2,CLOUGH>::n_dofs_per_elem(const ElemType t, const Order o) { return clough_n_dofs_per_elem(t, o); }
  template <> unsigned int FE<3,CLOUGH>::n_dofs_per_elem(const ElemType t, const Order o) { return clough_n_dofs_per_elem(t, o); }

  // Clough FEMs are C^1 continuous
  template <> FEContinuity FE<0,CLOUGH>::get_continuity() const { return C_ONE; }
  template <> FEContinuity FE<1,CLOUGH>::get_continuity() const { return C_ONE; }
  template <> FEContinuity FE<2,CLOUGH>::get_continuity() const { return C_ONE; }
  template <> FEContinuity FE<3,CLOUGH>::get_continuity() const { return C_ONE; }

  // Clough FEMs are not (currently) hierarchic
  template <> bool FE<0,CLOUGH>::is_hierarchic() const { return false; } // FIXME - this will be changed
  template <> bool FE<1,CLOUGH>::is_hierarchic() const { return false; } // FIXME - this will be changed
  template <> bool FE<2,CLOUGH>::is_hierarchic() const { return false; } // FIXME - this will be changed
  template <> bool FE<3,CLOUGH>::is_hierarchic() const { return false; } // FIXME - this will be changed

#ifdef LIBMESH_ENABLE_AMR
  // compute_constraints() specializations are only needed for 2 and 3D
  template <>
  void FE<2,CLOUGH>::compute_constraints (DofConstraints &constraints,
                                          DofMap &dof_map,
                                          const unsigned int variable_number,
                                          const Elem* elem)
  { compute_proj_constraints(constraints, dof_map, variable_number, elem); }

  template <>
  void FE<3,CLOUGH>::compute_constraints (DofConstraints &constraints,
                                          DofMap &dof_map,
                                          const unsigned int variable_number,
                                          const Elem* elem)
  { compute_proj_constraints(constraints, dof_map, variable_number, elem); }
#endif // #ifdef LIBMESH_ENABLE_AMR

  // Clough FEM shapes need reinit
  template <> bool FE<0,CLOUGH>::shapes_need_reinit() const { return true; }
  template <> bool FE<1,CLOUGH>::shapes_need_reinit() const { return true; }
  template <> bool FE<2,CLOUGH>::shapes_need_reinit() const { return true; }
  template <> bool FE<3,CLOUGH>::shapes_need_reinit() const { return true; }

} // namespace libMesh

---

Site Created By: libMesh Developers
Last modified: February 05 2013 19:54:46 UTC

Hosted By: