tensor_product_polynomials_const.h

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// ------------------------------------------------------------------------
//
// SPDX-License-Identifier: LGPL-2.1-or-later
// Copyright (C) 2013 - 2023 by the deal.II authors
//
// This file is part of the deal.II library.
//
// Part of the source code is dual licensed under Apache-2.0 WITH
// LLVM-exception OR LGPL-2.1-or-later. Detailed license information
// governing the source code and code contributions can be found in
// LICENSE.md and CONTRIBUTING.md at the top level directory of deal.II.
//
// ------------------------------------------------------------------------
 
#ifndef dealii_tensor_product_polynomials_const_h
#define dealii_tensor_product_polynomials_const_h
 
 
#include <deal.II/base/config.h>
 
#include <deal.II/base/exceptions.h>
#include <deal.II/base/point.h>
#include <deal.II/base/polynomial.h>
#include <deal.II/base/tensor.h>
#include <deal.II/base/tensor_product_polynomials.h>
#include <deal.II/base/utilities.h>
 
#include <vector>
 
DEAL_II_NAMESPACE_OPEN
 
 
template <int dim>
class TensorProductPolynomialsConst : public ScalarPolynomialsBase<dim>
{
public:
  static constexpr unsigned int dimension = dim;
 
  template <class Pol>
  TensorProductPolynomialsConst(const std::vector<Pol> &pols);
 
  void
  output_indices(std::ostream &out) const;
 
  void
  set_numbering(const std::vector<unsigned int> &renumber);
 
  const std::vector<unsigned int> &
  get_numbering() const;
 
  const std::vector<unsigned int> &
  get_numbering_inverse() const;
 
  void
  evaluate(const Point<dim>            &unit_point,
           std::vector<double>         &values,
           std::vector<Tensor<1, dim>> &grads,
           std::vector<Tensor<2, dim>> &grad_grads,
           std::vector<Tensor<3, dim>> &third_derivatives,
           std::vector<Tensor<4, dim>> &fourth_derivatives) const override;
 
  double
  compute_value(const unsigned int i, const Point<dim> &p) const override;
 
  template <int order>
  Tensor<order, dim>
  compute_derivative(const unsigned int i, const Point<dim> &p) const;
 
  virtual Tensor<1, dim>
  compute_1st_derivative(const unsigned int i,
                         const Point<dim>  &p) const override;
 
  virtual Tensor<2, dim>
  compute_2nd_derivative(const unsigned int i,
                         const Point<dim>  &p) const override;
 
  virtual Tensor<3, dim>
  compute_3rd_derivative(const unsigned int i,
                         const Point<dim>  &p) const override;
 
  virtual Tensor<4, dim>
  compute_4th_derivative(const unsigned int i,
                         const Point<dim>  &p) const override;
 
  Tensor<1, dim>
  compute_grad(const unsigned int i, const Point<dim> &p) const override;
 
  Tensor<2, dim>
  compute_grad_grad(const unsigned int i, const Point<dim> &p) const override;
 
  unsigned int
  n() const;
 
  std::string
  name() const override;
 
  virtual std::unique_ptr<ScalarPolynomialsBase<dim>>
  clone() const override;
 
private:
  TensorProductPolynomials<dim> tensor_polys;
 
  std::vector<unsigned int> index_map;
 
  std::vector<unsigned int> index_map_inverse;
};
 
/* ---------------- template and inline functions ---------- */
 
#ifndef DOXYGEN
 
template <int dim>
template <class Pol>
inline TensorProductPolynomialsConst<dim>::TensorProductPolynomialsConst(
  const std::vector<Pol> &pols)
  : ScalarPolynomialsBase<dim>(1, Utilities::fixed_power<dim>(pols.size()) + 1)
  , tensor_polys(pols)
  , index_map(tensor_polys.n() + 1)
  , index_map_inverse(tensor_polys.n() + 1)
{}
 
 
 
template <int dim>
inline unsigned int
TensorProductPolynomialsConst<dim>::n() const
{
  return tensor_polys.n() + 1;
}
 
 
 
template <int dim>
inline const std::vector<unsigned int> &
TensorProductPolynomialsConst<dim>::get_numbering() const
{
  return index_map;
}
 
 
template <int dim>
inline const std::vector<unsigned int> &
TensorProductPolynomialsConst<dim>::get_numbering_inverse() const
{
  return index_map_inverse;
}
 
 
template <int dim>
inline std::string
TensorProductPolynomialsConst<dim>::name() const
{
  return "TensorProductPolynomialsConst";
}
 
 
template <>
inline unsigned int
TensorProductPolynomialsConst<0>::n() const
{
  return numbers::invalid_unsigned_int;
}
 
 
template <int dim>
template <int order>
Tensor<order, dim>
TensorProductPolynomialsConst<dim>::compute_derivative(
  const unsigned int i,
  const Point<dim>  &p) const
{
  const unsigned int max_indices = tensor_polys.n();
  Assert(i <= max_indices, ExcInternalError());
 
  // treat the regular basis functions
  if (i < max_indices)
    return tensor_polys.template compute_derivative<order>(i, p);
  else
    // this is for the constant function
    return Tensor<order, dim>();
}
 
 
 
template <int dim>
inline Tensor<1, dim>
TensorProductPolynomialsConst<dim>::compute_1st_derivative(
  const unsigned int i,
  const Point<dim>  &p) const
{
  return compute_derivative<1>(i, p);
}
 
 
 
template <int dim>
inline Tensor<2, dim>
TensorProductPolynomialsConst<dim>::compute_2nd_derivative(
  const unsigned int i,
  const Point<dim>  &p) const
{
  return compute_derivative<2>(i, p);
}
 
 
 
template <int dim>
inline Tensor<3, dim>
TensorProductPolynomialsConst<dim>::compute_3rd_derivative(
  const unsigned int i,
  const Point<dim>  &p) const
{
  return compute_derivative<3>(i, p);
}
 
 
 
template <int dim>
inline Tensor<4, dim>
TensorProductPolynomialsConst<dim>::compute_4th_derivative(
  const unsigned int i,
  const Point<dim>  &p) const
{
  return compute_derivative<4>(i, p);
}
 
#endif // DOXYGEN
DEAL_II_NAMESPACE_CLOSE
 
#endif