Taxisym_navier_stokes_elements.h

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// LIC// ====================================================================
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// LIC// multi-physics finite-element library, available
// LIC// at http://www.oomph-lib.org.
// LIC//
// LIC// Copyright (C) 2006-2022 Matthias Heil and Andrew Hazel
// LIC//
// LIC// This library is free software; you can redistribute it and/or
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// LIC// License as published by the Free Software Foundation; either
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// LIC// Lesser General Public License for more details.
// LIC//
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// LIC//====================================================================
// Header file for triangular/tetrahedaral Axisymmetric Navier Stokes elements
 
#ifndef OOMPH_TAXISYM_NAVIER_STOKES_ELEMENTS_HEADER
#define OOMPH_TAXISYM_NAVIER_STOKES_ELEMENTS_HEADER
 
// Config header generated by autoconfig
#ifdef HAVE_CONFIG_H
#include <oomph-lib-config.h>
#endif
 
 
// OOMPH-LIB headers
#include "../generic/Telements.h"
#include "axisym_navier_stokes_elements.h"
#include "../generic/error_estimator.h"
 
namespace oomph
{
  // NOTE: TRI/TET CROZIER RAVIARTS REQUIRE BUBBLE FUNCTIONS! THEY'RE NOT
  // STRAIGHTFORWARD GENERALISATIONS OF THE Q-EQUIVALENTS (WHICH ARE
  // LBB UNSTABLE!)
 
 
  //==========================================================================
  //==========================================================================
  class AxisymmetricTCrouzeixRaviartElement
    : public virtual TBubbleEnrichedElement<2, 3>,
      public virtual AxisymmetricNavierStokesEquations,
      public virtual ElementWithZ2ErrorEstimator
  {
  protected:
    unsigned P_axi_nst_internal_index;
 
 
    inline double dshape_and_dtest_eulerian_axi_nst(const Vector<double>& s,
                                                    Shape& psi,
                                                    DShape& dpsidx,
                                                    Shape& test,
                                                    DShape& dtestdx) const;
 
    inline double dshape_and_dtest_eulerian_at_knot_axi_nst(
      const unsigned& ipt,
      Shape& psi,
      DShape& dpsidx,
      Shape& test,
      DShape& dtestdx) const;
 
    inline double dshape_and_dtest_eulerian_at_knot_axi_nst(
      const unsigned& ipt,
      Shape& psi,
      DShape& dpsidx,
      RankFourTensor<double>& d_dpsidx_dX,
      Shape& test,
      DShape& dtestdx,
      RankFourTensor<double>& d_dtestdx_dX,
      DenseMatrix<double>& djacobian_dX) const;
 
    inline double dpshape_and_dptest_eulerian_axi_nst(const Vector<double>& s,
                                                      Shape& ppsi,
                                                      DShape& dppsidx,
                                                      Shape& ptest,
                                                      DShape& dptestdx) const;
 
  public:
    inline void pshape_axi_nst(const Vector<double>& s, Shape& psi) const;
 
    inline void pshape_axi_nst(const Vector<double>& s,
                               Shape& psi,
                               Shape& test) const;
 
    void unpin_all_internal_pressure_dofs();
 
    inline int p_local_eqn(const unsigned& n) const
    {
      return this->internal_local_eqn(P_axi_nst_internal_index, n);
    }
 
  public:
    AxisymmetricTCrouzeixRaviartElement()
      : TBubbleEnrichedElement<2, 3>(), AxisymmetricNavierStokesEquations()
    {
      // Allocate and a single internal datum with 3 entries for the
      // pressure
      P_axi_nst_internal_index = this->add_internal_data(new Data(3));
    }
 
    AxisymmetricTCrouzeixRaviartElement(
      const AxisymmetricTCrouzeixRaviartElement& dummy) = delete;
 
    // Commented out broken assignment operator because this can lead to a
    // conflict warning when used in the virtual inheritence hierarchy.
    // Essentially the compiler doesn't realise that two separate
    // implementations of the broken function are the same and so, quite
    // rightly, it shouts.
    /*void operator=(const AxisymmetricTCrouzeixRaviartElement&) =
      delete;*/
 
 
    inline virtual unsigned required_nvalue(const unsigned& n) const
    {
      return 3;
    }
 
 
    double p_axi_nst(const unsigned& i) const
    {
      return this->internal_data_pt(P_axi_nst_internal_index)->value(i);
    }
 
    unsigned npres_axi_nst() const
    {
      return 3;
    }
 
    void fix_pressure(const unsigned& p_dof, const double& p_value)
    {
      this->internal_data_pt(P_axi_nst_internal_index)->pin(p_dof);
      this->internal_data_pt(P_axi_nst_internal_index)
        ->set_value(p_dof, p_value);
    }
 
    // void build_fp_press_adv_diff_robin_bc_element(const unsigned&
    //                                              face_index)
    // {
    // this->Pressure_advection_diffusion_robin_element_pt.push_back(
    //  new
    //  FpPressureAdvDiffRobinBCElement<AxisymmetricTCrouzeixRaviartElement<DIM>
    //  >(
    //   this, face_index));
    // }
 
    void identify_load_data(
      std::set<std::pair<Data*, unsigned>>& paired_load_data);
 
    void identify_pressure_data(
      std::set<std::pair<Data*, unsigned>>& paired_pressure_data);
 
    void output(std::ostream& outfile)
    {
      AxisymmetricNavierStokesEquations::output(outfile);
    }
 
    void output(std::ostream& outfile, const unsigned& nplot)
    {
      AxisymmetricNavierStokesEquations::output(outfile, nplot);
    }
 
    void output(FILE* file_pt)
    {
      AxisymmetricNavierStokesEquations::output(file_pt);
    }
 
    void output(FILE* file_pt, const unsigned& n_plot)
    {
      AxisymmetricNavierStokesEquations::output(file_pt, n_plot);
    }
 
 
    unsigned nrecovery_order()
    {
      return 2;
    }
 
    unsigned nvertex_node() const
    {
      return 3;
    }
 
    Node* vertex_node_pt(const unsigned& j) const
    {
      return node_pt(j);
    }
 
    unsigned num_Z2_flux_terms()
    {
      // 3 diagonal strain rates, 3 off diagonal
      return 6;
    }
 
    void get_Z2_flux(const Vector<double>& s, Vector<double>& flux)
    {
#ifdef PARANOID
      unsigned num_entries = 6;
      if (flux.size() < num_entries)
      {
        std::ostringstream error_message;
        error_message << "The flux vector has the wrong number of entries, "
                      << flux.size() << ", whereas it should be at least "
                      << num_entries << std::endl;
        throw OomphLibError(error_message.str(),
                            OOMPH_CURRENT_FUNCTION,
                            OOMPH_EXCEPTION_LOCATION);
      }
#endif
 
      // Get strain rate matrix
      DenseMatrix<double> strainrate(3);
      this->strain_rate(s, strainrate);
 
      // Pack into flux Vector
      unsigned icount = 0;
 
      // Start with diagonal terms
      for (unsigned i = 0; i < 3; i++)
      {
        flux[icount] = strainrate(i, i);
        icount++;
      }
 
      // Off diagonals row by row
      for (unsigned i = 0; i < 3; i++)
      {
        for (unsigned j = i + 1; j < 3; j++)
        {
          flux[icount] = strainrate(i, j);
          icount++;
        }
      }
    }
 
 
    unsigned ndof_types() const
    {
      return 4;
    }
 
    void get_dof_numbers_for_unknowns(
      std::list<std::pair<unsigned long, unsigned>>& dof_lookup_list) const
    {
      // number of nodes
      unsigned n_node = this->nnode();
 
      // number of pressure values
      unsigned n_press = this->npres_axi_nst();
 
      // temporary pair (used to store dof lookup prior to being added to list)
      std::pair<unsigned, unsigned> dof_lookup;
 
      // pressure dof number
      unsigned pressure_dof_number = 3;
 
      // loop over the pressure values
      for (unsigned n = 0; n < n_press; n++)
      {
        // determine local eqn number
        int local_eqn_number = this->p_local_eqn(n);
 
        // ignore pinned values - far away degrees of freedom resulting
        // from hanging nodes can be ignored since these are be dealt
        // with by the element containing their master nodes
        if (local_eqn_number >= 0)
        {
          // store dof lookup in temporary pair: First entry in pair
          // is global equation number; second entry is dof type
          dof_lookup.first = this->eqn_number(local_eqn_number);
          dof_lookup.second = pressure_dof_number;
 
          // add to list
          dof_lookup_list.push_front(dof_lookup);
        }
      }
 
      // loop over the nodes
      for (unsigned n = 0; n < n_node; n++)
      {
        // find the number of values at this node
        unsigned nv = this->node_pt(n)->nvalue();
 
        // loop over these values
        for (unsigned v = 0; v < nv; v++)
        {
          // determine local eqn number
          int local_eqn_number = this->nodal_local_eqn(n, v);
 
          // ignore pinned values
          if (local_eqn_number >= 0)
          {
            // store dof lookup in temporary pair: First entry in pair
            // is global equation number; second entry is dof type
            dof_lookup.first = this->eqn_number(local_eqn_number);
            dof_lookup.second = v;
 
            // add to list
            dof_lookup_list.push_front(dof_lookup);
          }
        }
      }
    }
  };
 
  // Inline functions
 
  //=======================================================================
  //=======================================================================
  inline double AxisymmetricTCrouzeixRaviartElement::
    dshape_and_dtest_eulerian_axi_nst(const Vector<double>& s,
                                      Shape& psi,
                                      DShape& dpsidx,
                                      Shape& test,
                                      DShape& dtestdx) const
  {
    // Call the geometrical shape functions and derivatives
    double J = this->dshape_eulerian(s, psi, dpsidx);
    // The test functions are equal to the shape functions
    test = psi;
    dtestdx = dpsidx;
    // Return the jacobian
    return J;
  }
 
 
  //=======================================================================
  //=======================================================================
  inline double AxisymmetricTCrouzeixRaviartElement::
    dshape_and_dtest_eulerian_at_knot_axi_nst(const unsigned& ipt,
                                              Shape& psi,
                                              DShape& dpsidx,
                                              Shape& test,
                                              DShape& dtestdx) const
  {
    // Call the geometrical shape functions and derivatives
    double J = this->dshape_eulerian_at_knot(ipt, psi, dpsidx);
    // The test functions are the shape functions
    test = psi;
    dtestdx = dpsidx;
    // Return the jacobian
    return J;
  }
 
 
  //=======================================================================
  //=======================================================================
  inline double AxisymmetricTCrouzeixRaviartElement::
    dshape_and_dtest_eulerian_at_knot_axi_nst(
      const unsigned& ipt,
      Shape& psi,
      DShape& dpsidx,
      RankFourTensor<double>& d_dpsidx_dX,
      Shape& test,
      DShape& dtestdx,
      RankFourTensor<double>& d_dtestdx_dX,
      DenseMatrix<double>& djacobian_dX) const
  {
    // Call the geometrical shape functions and derivatives
    const double J = this->dshape_eulerian_at_knot(
      ipt, psi, dpsidx, djacobian_dX, d_dpsidx_dX);
 
    // Set the test functions equal to the shape functions
    test = psi;
    dtestdx = dpsidx;
    d_dtestdx_dX = d_dpsidx_dX;
 
    // Return the jacobian
    return J;
  }
 
 
  //=======================================================================
  //=======================================================================
  inline void AxisymmetricTCrouzeixRaviartElement::pshape_axi_nst(
    const Vector<double>& s, Shape& psi) const
  {
    psi[0] = 1.0;
    psi[1] = s[0];
    psi[2] = s[1];
  }
 
  //=======================================================================
  //=======================================================================
  inline void AxisymmetricTCrouzeixRaviartElement::pshape_axi_nst(
    const Vector<double>& s, Shape& psi, Shape& test) const
  {
    // Call the pressure shape functions
    this->pshape_axi_nst(s, psi);
    // The test functions are the shape functions
    test = psi;
  }
 
  //==========================================================================
  //==========================================================================
  inline double AxisymmetricTCrouzeixRaviartElement::
    dpshape_and_dptest_eulerian_axi_nst(const Vector<double>& s,
                                        Shape& ppsi,
                                        DShape& dppsidx,
                                        Shape& ptest,
                                        DShape& dptestdx) const
  {
    // Initalise with shape fcts and derivs. w.r.t. to local coordinates
    ppsi[0] = 1.0;
    ppsi[1] = s[0];
    ppsi[2] = s[1];
 
    dppsidx(0, 0) = 0.0;
    dppsidx(1, 0) = 1.0;
    dppsidx(2, 0) = 0.0;
 
    dppsidx(0, 1) = 0.0;
    dppsidx(1, 1) = 0.0;
    dppsidx(2, 1) = 1.0;
 
 
    // Get the values of the shape functions and their local derivatives
    Shape psi(7);
    DShape dpsi(7, 2);
    dshape_local(s, psi, dpsi);
 
    // Allocate memory for the inverse 2x2 jacobian
    DenseMatrix<double> inverse_jacobian(2);
 
    // Now calculate the inverse jacobian
    const double det = local_to_eulerian_mapping(dpsi, inverse_jacobian);
 
    // Now set the values of the derivatives to be derivs w.r.t. to the
    // Eulerian coordinates
    transform_derivatives(inverse_jacobian, dppsidx);
 
    // The test functions are equal to the shape functions
    ptest = ppsi;
    dptestdx = dppsidx;
 
    // Return the determinant of the jacobian
    return det;
  }
 
 
  //=======================================================================
  //=======================================================================
  template<>
  class FaceGeometry<AxisymmetricTCrouzeixRaviartElement>
    : public virtual TElement<1, 3>
  {
  public:
    FaceGeometry() : TElement<1, 3>() {}
  };
 
 
  //=======================================================================
  //=======================================================================
  template<>
  class FaceGeometry<FaceGeometry<AxisymmetricTCrouzeixRaviartElement>>
    : public virtual PointElement
  {
  public:
    FaceGeometry() : PointElement() {}
  };
 
 
 
 
  //=======================================================================
  //=======================================================================
  class AxisymmetricTTaylorHoodElement
    : public virtual TElement<2, 3>,
      public virtual AxisymmetricNavierStokesEquations,
      public virtual ElementWithZ2ErrorEstimator
 
  {
  private:
    static const unsigned Initial_Nvalue[];
 
  protected:
    static const unsigned Pconv[];
 
    inline double dshape_and_dtest_eulerian_axi_nst(const Vector<double>& s,
                                                    Shape& psi,
                                                    DShape& dpsidx,
                                                    Shape& test,
                                                    DShape& dtestdx) const;
 
    inline double dshape_and_dtest_eulerian_at_knot_axi_nst(
      const unsigned& ipt,
      Shape& psi,
      DShape& dpsidx,
      Shape& test,
      DShape& dtestdx) const;
 
    inline double dshape_and_dtest_eulerian_at_knot_axi_nst(
      const unsigned& ipt,
      Shape& psi,
      DShape& dpsidx,
      RankFourTensor<double>& d_dpsidx_dX,
      Shape& test,
      DShape& dtestdx,
      RankFourTensor<double>& d_dtestdx_dX,
      DenseMatrix<double>& djacobian_dX) const;
 
    virtual double dpshape_and_dptest_eulerian_axi_nst(const Vector<double>& s,
                                                       Shape& ppsi,
                                                       DShape& dppsidx,
                                                       Shape& ptest,
                                                       DShape& dptestdx) const;
 
    void unpin_all_nodal_pressure_dofs();
 
    void pin_all_nodal_pressure_dofs();
 
    void unpin_proper_nodal_pressure_dofs();
 
 
  public:
    AxisymmetricTTaylorHoodElement()
      : TElement<2, 3>(), AxisymmetricNavierStokesEquations()
    {
    }
 
 
    AxisymmetricTTaylorHoodElement(
      const AxisymmetricTTaylorHoodElement& dummy) = delete;
 
    /*void operator=(const AxisymmetricTTaylorHoodElement&) =
      delete;*/
 
    inline virtual unsigned required_nvalue(const unsigned& n) const
    {
      return Initial_Nvalue[n];
    }
 
    // bool pressure_dof_is_hanging(const unsigned& p_dof)
    // {return this->node_pt(Pconv[p_dof])->is_hanging(DIM);}
 
 
    inline void pshape_axi_nst(const Vector<double>& s, Shape& psi) const;
 
    inline void pshape_axi_nst(const Vector<double>& s,
                               Shape& psi,
                               Shape& test) const;
 
    unsigned p_index_axi_nst()
    {
      return 3;
    }
 
    // Node* pressure_node_pt(const unsigned &n_p)
    //{return this->Node_pt[Pconv[n_p]];}
 
    inline int p_local_eqn(const unsigned& n) const
    {
      return this->nodal_local_eqn(Pconv[n], 3);
    }
 
    double p_axi_nst(const unsigned& n_p) const
    {
      return this->nodal_value(Pconv[n_p], 3);
    }
 
    int p_nodal_index_axi_nst() const
    {
      return static_cast<int>(3);
    }
 
    unsigned npres_axi_nst() const
    {
      return 3;
    }
 
    void fix_pressure(const unsigned& p_dof, const double& p_value)
    {
      this->node_pt(Pconv[p_dof])->pin(3);
      this->node_pt(Pconv[p_dof])->set_value(3, p_value);
    }
 
 
    // void build_fp_press_adv_diff_robin_bc_element(const unsigned&
    //                                               face_index)
    // {
    //  this->Pressure_advection_diffusion_robin_element_pt.push_back(
    //   new FpPressureAdvDiffRobinBCElement<AxisymmetricTTaylorHoodElement<DIM>
    //   >(
    //    this, face_index));
    // }
 
    void identify_load_data(
      std::set<std::pair<Data*, unsigned>>& paired_load_data);
 
    void identify_pressure_data(
      std::set<std::pair<Data*, unsigned>>& paired_pressure_data);
 
    void output(std::ostream& outfile)
    {
      AxisymmetricNavierStokesEquations::output(outfile);
    }
 
    void output(std::ostream& outfile, const unsigned& nplot)
    {
      AxisymmetricNavierStokesEquations::output(outfile, nplot);
    }
 
    void output(FILE* file_pt)
    {
      AxisymmetricNavierStokesEquations::output(file_pt);
    }
 
    void output(FILE* file_pt, const unsigned& n_plot)
    {
      AxisymmetricNavierStokesEquations::output(file_pt, n_plot);
    }
 
    unsigned nrecovery_order()
    {
      return 2;
    }
 
    unsigned nvertex_node() const
    {
      return 3;
    }
 
    Node* vertex_node_pt(const unsigned& j) const
    {
      return node_pt(j);
    }
 
 
    unsigned num_Z2_flux_terms()
    {
      // 3 diagonal strain rates, 3 off diagonal rates
      return 6;
    }
 
    void get_Z2_flux(const Vector<double>& s, Vector<double>& flux)
    {
#ifdef PARANOID
      unsigned num_entries = 6;
      if (flux.size() < num_entries)
      {
        std::ostringstream error_message;
        error_message << "The flux vector has the wrong number of entries, "
                      << flux.size() << ", whereas it should be at least "
                      << num_entries << std::endl;
        throw OomphLibError(error_message.str(),
                            OOMPH_CURRENT_FUNCTION,
                            OOMPH_EXCEPTION_LOCATION);
      }
#endif
 
      // Get strain rate matrix
      DenseMatrix<double> strainrate(3);
      this->strain_rate(s, strainrate);
 
      // Pack into flux Vector
      unsigned icount = 0;
 
      // Start with diagonal terms
      for (unsigned i = 0; i < 3; i++)
      {
        flux[icount] = strainrate(i, i);
        icount++;
      }
 
      // Off diagonals row by row
      for (unsigned i = 0; i < 3; i++)
      {
        for (unsigned j = i + 1; j < 3; j++)
        {
          flux[icount] = strainrate(i, j);
          icount++;
        }
      }
    }
 
    unsigned ndof_types() const
    {
      return 4;
    }
 
    void get_dof_numbers_for_unknowns(
      std::list<std::pair<unsigned long, unsigned>>& dof_lookup_list) const
    {
      // number of nodes
      unsigned n_node = this->nnode();
 
      // temporary pair (used to store dof lookup prior to being added to list)
      std::pair<unsigned, unsigned> dof_lookup;
 
      // loop over the nodes
      for (unsigned n = 0; n < n_node; n++)
      {
        // find the number of Navier Stokes values at this node
        unsigned nv = this->required_nvalue(n);
 
        // loop over these values
        for (unsigned v = 0; v < nv; v++)
        {
          // determine local eqn number
          int local_eqn_number = this->nodal_local_eqn(n, v);
 
          // ignore pinned values - far away degrees of freedom resulting
          // from hanging nodes can be ignored since these are be dealt
          // with by the element containing their master nodes
          if (local_eqn_number >= 0)
          {
            // store dof lookup in temporary pair: Global equation number
            // is the first entry in pair
            dof_lookup.first = this->eqn_number(local_eqn_number);
 
            // set dof numbers: Dof number is the second entry in pair
            dof_lookup.second = v;
 
            // add to list
            dof_lookup_list.push_front(dof_lookup);
          }
        }
      }
    }
  };
 
 
  // Inline functions
 
  //==========================================================================
  //==========================================================================
  inline double AxisymmetricTTaylorHoodElement::
    dshape_and_dtest_eulerian_axi_nst(const Vector<double>& s,
                                      Shape& psi,
                                      DShape& dpsidx,
                                      Shape& test,
                                      DShape& dtestdx) const
  {
    // Call the geometrical shape functions and derivatives
    double J = this->dshape_eulerian(s, psi, dpsidx);
    // Test functions are the shape functions
    test = psi;
    dtestdx = dpsidx;
    // Return the jacobian
    return J;
  }
 
 
  //==========================================================================
  //==========================================================================
  inline double AxisymmetricTTaylorHoodElement::
    dshape_and_dtest_eulerian_at_knot_axi_nst(const unsigned& ipt,
                                              Shape& psi,
                                              DShape& dpsidx,
                                              Shape& test,
                                              DShape& dtestdx) const
  {
    // Call the geometrical shape functions and derivatives
    double J = this->dshape_eulerian_at_knot(ipt, psi, dpsidx);
    // Test functions are the shape functions
    test = psi;
    dtestdx = dpsidx;
    // Return the jacobian
    return J;
  }
 
  //==========================================================================
  //==========================================================================
  inline double AxisymmetricTTaylorHoodElement::
    dshape_and_dtest_eulerian_at_knot_axi_nst(
      const unsigned& ipt,
      Shape& psi,
      DShape& dpsidx,
      RankFourTensor<double>& d_dpsidx_dX,
      Shape& test,
      DShape& dtestdx,
      RankFourTensor<double>& d_dtestdx_dX,
      DenseMatrix<double>& djacobian_dX) const
  {
    // Call the geometrical shape functions and derivatives
    const double J = this->dshape_eulerian_at_knot(
      ipt, psi, dpsidx, djacobian_dX, d_dpsidx_dX);
 
    // Set the test functions equal to the shape functions
    test = psi;
    dtestdx = dpsidx;
    d_dtestdx_dX = d_dpsidx_dX;
 
    // Return the jacobian
    return J;
  }
 
  //==========================================================================
  //==========================================================================
  inline double AxisymmetricTTaylorHoodElement::
    dpshape_and_dptest_eulerian_axi_nst(const Vector<double>& s,
                                        Shape& ppsi,
                                        DShape& dppsidx,
                                        Shape& ptest,
                                        DShape& dptestdx) const
  {
    ppsi[0] = s[0];
    ppsi[1] = s[1];
    ppsi[2] = 1.0 - s[0] - s[1];
 
    dppsidx(0, 0) = 1.0;
    dppsidx(0, 1) = 0.0;
 
    dppsidx(1, 0) = 0.0;
    dppsidx(1, 1) = 1.0;
 
    dppsidx(2, 0) = -1.0;
    dppsidx(2, 1) = -1.0;
 
    // Allocate memory for the inverse 2x2 jacobian
    DenseMatrix<double> inverse_jacobian(2);
 
 
    // Get the values of the shape functions and their local derivatives
    Shape psi(6);
    DShape dpsi(6, 2);
    dshape_local(s, psi, dpsi);
 
    // Now calculate the inverse jacobian
    const double det = local_to_eulerian_mapping(dpsi, inverse_jacobian);
 
    // Now set the values of the derivatives to be derivs w.r.t. to the
    // Eulerian coordinates
    transform_derivatives(inverse_jacobian, dppsidx);
 
    // Test functions are shape functions
    ptest = ppsi;
    dptestdx = dppsidx;
 
    // Return the determinant of the jacobian
    return det;
  }
 
 
  //==========================================================================
  //==========================================================================
  inline void AxisymmetricTTaylorHoodElement::pshape_axi_nst(
    const Vector<double>& s, Shape& psi) const
  {
    psi[0] = s[0];
    psi[1] = s[1];
    psi[2] = 1.0 - s[0] - s[1];
  }
 
  //==========================================================================
  //==========================================================================
  inline void AxisymmetricTTaylorHoodElement::pshape_axi_nst(
    const Vector<double>& s, Shape& psi, Shape& test) const
  {
    // Call the pressure shape functions
    this->pshape_axi_nst(s, psi);
    // Test functions are shape functions
    test = psi;
  }
 
 
  //=======================================================================
  //=======================================================================
  template<>
  class FaceGeometry<AxisymmetricTTaylorHoodElement>
    : public virtual TElement<1, 3>
  {
  public:
    FaceGeometry() : TElement<1, 3>() {}
  };
 
 
  //=======================================================================
  //=======================================================================
  template<>
  class FaceGeometry<FaceGeometry<AxisymmetricTTaylorHoodElement>>
    : public virtual PointElement
  {
  public:
    FaceGeometry() : PointElement() {}
  };
 
 
} // namespace oomph
 
#endif