function_spherical.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2016 - 2017 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, 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.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#ifndef dealii_function_spherical_h
#define dealii_function_spherical_h

#include <deal.II/base/config.h>

#include <deal.II/base/function.h>
#include <deal.II/base/point.h>


#include <array>

DEAL_II_NAMESPACE_OPEN

namespace Functions
{

  template <int dim>
  class Spherical : public Function<dim>
  {
  public:
    Spherical(const Point<dim> &center = Point<dim>(),
              const unsigned int n_components=1);

    virtual double value (const Point<dim> &point,
                          const unsigned int component = 0) const;

    virtual Tensor<1,dim> gradient (const Point<dim>   &p,
                                    const unsigned int  component = 0) const;

    virtual SymmetricTensor<2,dim> hessian (const Point<dim> &p,
                                            const unsigned int component=0) const;

    std::size_t memory_consumption () const;

  private:
    virtual double svalue(const std::array<double, dim> &sp,
                          const unsigned int component) const;

    virtual std::array<double, dim> sgradient(const std::array<double, dim> &sp,
                                              const unsigned int component) const;

    virtual std::array<double, 6> shessian (const std::array<double, dim> &sp,
                                            const unsigned int component) const;

    const Tensor<1,dim> coordinate_system_offset;
  };
}

DEAL_II_NAMESPACE_CLOSE

#endif