pwl_slab_02_x_shapefuncs.cc

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#include "PieceWiseLinearSlabMapping.h"
#include "mesh/MeshContinuum/chi_meshcontinuum.h"
 
namespace chi_math::cell_mapping
{
 
/**Shape function i evaluated at given point for the slab.*/
double
PieceWiseLinearSlabMapping::ShapeValue(const int i,
                                     const chi_mesh::Vector3& xyz) const
{
  const auto& p0 = ref_grid_.vertices[v0i_];
  const auto& p1 = ref_grid_.vertices[v1i_];
  chi_mesh::Vector3 xyz_ref = xyz - p0;
 
  chi_mesh::Vector3 v01 = p1 - p0;
 
  double xi = v01.Dot(xyz_ref) / v01.Norm() / h_;
 
  if ((xi >= -1.0e-6) and (xi <= 1.0 + 1.0e-6))
  {
    if (i == 0) return 1.0 - xi;
    else
      return xi;
  } // if in cell
 
  return 0.0;
}
 
// #################################################################
/**Populates shape_values with the value of each shape function's
 * value evaluate at the supplied point.*/
void PieceWiseLinearSlabMapping::ShapeValues(const chi_mesh::Vector3& xyz,
                                    std::vector<double>& shape_values) const
{
  shape_values.resize(num_nodes_, 0.0);
  const auto& p0 = ref_grid_.vertices[v0i_];
  const auto& p1 = ref_grid_.vertices[v1i_];
  chi_mesh::Vector3 xyz_ref = xyz - p0;
 
  chi_mesh::Vector3 v01 = p1 - p0;
 
  double xi = v01.Dot(xyz_ref) / v01.Norm() / h_;
 
  if ((xi >= -1.0e-6) and (xi <= 1.0 + 1.0e-6))
  {
    for (int i = 0; i < num_nodes_; i++)
    {
      if (i == 0) shape_values[i] = 1.0 - xi;
      else
        shape_values[i] = xi;
    } // for dof
 
    return;
  } // if in cell
}
 
// ###################################################################
/**Returns the evaluation of grad-shape function i at the supplied point.*/
chi_mesh::Vector3
PieceWiseLinearSlabMapping::GradShapeValue(const int i,
                                  const chi_mesh::Vector3& xyz) const
{
  if (i == 0) return chi_mesh::Vector3(0.0, 0.0, -1.0 / h_);
  else
    return chi_mesh::Vector3(0.0, 0.0, 1.0 / h_);
}
 
// ###################################################################
/**Populates shape_values with the value of each shape function's
 * value evaluate at the supplied point.*/
void PieceWiseLinearSlabMapping::GradShapeValues(
  const chi_mesh::Vector3& xyz,
  std::vector<chi_mesh::Vector3>& gradshape_values) const
{
  gradshape_values.clear();
  gradshape_values.emplace_back(GradShapeValue(0, xyz));
  gradshape_values.emplace_back(GradShapeValue(1, xyz));
}
 
} // namespace chi_math::cell_mapping