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fe_l2_hierarchic.C

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// 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
{

  // ------------------------------------------------------------
  // Hierarchic-specific implementations

  // Anonymous namespace for local helper functions
  namespace {

    void l2_hierarchic_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, L2_HIERARCHIC);

      switch (totalorder)
        {
          // Constant shape functions
        case CONSTANT:
          {
            libmesh_assert_equal_to (elem_soln.size(), 1);

            const Number val = elem_soln[0];

            for (unsigned int n=0; n<n_nodes; n++)
              nodal_soln[n] = val;

            return;
          }


          // For other orders do interpolation at the nodes
          // explicitly.
        default:
          {

            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;
          }
        }
    } // l2_hierarchic_nodal_soln()




    unsigned int l2_hierarchic_n_dofs(const ElemType t, const Order o)
    {
      libmesh_assert_greater (o, 0);
      switch (t)
        {
        case NODEELEM:
          return 1;
        case EDGE2:
        case EDGE3:
          return (o+1);
        case QUAD4:
        case QUAD8:
        case QUAD9:
          return ((o+1)*(o+1));
        case HEX8:
        case HEX20:
        case HEX27:
          return ((o+1)*(o+1)*(o+1));
        case TRI6:
          return ((o+1)*(o+2)/2);
        default:
          libmesh_error();
        }

      libmesh_error();
      return 0;
    } // l2_hierarchic_n_dofs()


  } // anonymous namespace




  // 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,L2_HIERARCHIC>::nodal_soln(const Elem* elem,
                                       const Order order,
                                       const std::vector<Number>& elem_soln,
                                       std::vector<Number>& nodal_soln)
  { l2_hierarchic_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/0); }

  template <>
  void FE<1,L2_HIERARCHIC>::nodal_soln(const Elem* elem,
                                       const Order order,
                                       const std::vector<Number>& elem_soln,
                                       std::vector<Number>& nodal_soln)
  { l2_hierarchic_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/1); }

  template <>
  void FE<2,L2_HIERARCHIC>::nodal_soln(const Elem* elem,
                                       const Order order,
                                       const std::vector<Number>& elem_soln,
                                       std::vector<Number>& nodal_soln)
  { l2_hierarchic_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/2); }

  template <>
  void FE<3,L2_HIERARCHIC>::nodal_soln(const Elem* elem,
                                       const Order order,
                                       const std::vector<Number>& elem_soln,
                                       std::vector<Number>& nodal_soln)
  { l2_hierarchic_nodal_soln(elem, order, elem_soln, nodal_soln, /*Dim=*/3); }

  // Full specialization of n_dofs() function for every dimension
  template <> unsigned int FE<0,L2_HIERARCHIC>::n_dofs(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }
  template <> unsigned int FE<1,L2_HIERARCHIC>::n_dofs(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }
  template <> unsigned int FE<2,L2_HIERARCHIC>::n_dofs(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }
  template <> unsigned int FE<3,L2_HIERARCHIC>::n_dofs(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }

  // Full specialization of n_dofs_at_node() function for every dimension.
  // Discontinuous L2 elements only have interior nodes
  template <> unsigned int FE<0,L2_HIERARCHIC>::n_dofs_at_node(const ElemType, const Order, const unsigned int) { return 0; }
  template <> unsigned int FE<1,L2_HIERARCHIC>::n_dofs_at_node(const ElemType, const Order, const unsigned int) { return 0; }
  template <> unsigned int FE<2,L2_HIERARCHIC>::n_dofs_at_node(const ElemType, const Order, const unsigned int) { return 0; }
  template <> unsigned int FE<3,L2_HIERARCHIC>::n_dofs_at_node(const ElemType, const Order, const unsigned int) { return 0; }

  // Full specialization of n_dofs_per_elem() function for every dimension.
  template <> unsigned int FE<0,L2_HIERARCHIC>::n_dofs_per_elem(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }
  template <> unsigned int FE<1,L2_HIERARCHIC>::n_dofs_per_elem(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }
  template <> unsigned int FE<2,L2_HIERARCHIC>::n_dofs_per_elem(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }
  template <> unsigned int FE<3,L2_HIERARCHIC>::n_dofs_per_elem(const ElemType t, const Order o) { return l2_hierarchic_n_dofs(t, o); }

  // L2 Hierarchic FEMs are C^0 continuous
  template <> FEContinuity FE<0,L2_HIERARCHIC>::get_continuity() const { return DISCONTINUOUS; }
  template <> FEContinuity FE<1,L2_HIERARCHIC>::get_continuity() const { return DISCONTINUOUS; }
  template <> FEContinuity FE<2,L2_HIERARCHIC>::get_continuity() const { return DISCONTINUOUS; }
  template <> FEContinuity FE<3,L2_HIERARCHIC>::get_continuity() const { return DISCONTINUOUS; }

  // L2 Hierarchic FEMs are hierarchic (duh!)
  template <> bool FE<0,L2_HIERARCHIC>::is_hierarchic() const { return true; }
  template <> bool FE<1,L2_HIERARCHIC>::is_hierarchic() const { return true; }
  template <> bool FE<2,L2_HIERARCHIC>::is_hierarchic() const { return true; }
  template <> bool FE<3,L2_HIERARCHIC>::is_hierarchic() const { return true; }

#ifdef LIBMESH_ENABLE_AMR
  // compute_constraints() is a NOOP for DISCONTINOUS FE's
  template <>
  void FE<2,L2_HIERARCHIC>::compute_constraints (DofConstraints &,
                                                 DofMap &,
                                                 const unsigned int,
                                                 const Elem*)
  { }

  template <>
  void FE<3,L2_HIERARCHIC>::compute_constraints (DofConstraints &,
                                                 DofMap &,
                                                 const unsigned int,
                                                 const Elem*)
  { }
#endif // #ifdef LIBMESH_ENABLE_AMR

  // L2-Hierarchic FEM shapes need reinit
  template <> bool FE<0,L2_HIERARCHIC>::shapes_need_reinit() const { return true; }
  template <> bool FE<1,L2_HIERARCHIC>::shapes_need_reinit() const { return true; }
  template <> bool FE<2,L2_HIERARCHIC>::shapes_need_reinit() const { return true; }
  template <> bool FE<3,L2_HIERARCHIC>::shapes_need_reinit() const { return true; }

} // namespace libMesh

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Last modified: February 05 2013 19:54:46 UTC

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