exact_solution.h

// This file is part of Hermes2D.
//
// Hermes2D is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// Hermes2D 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Hermes2D.  If not, see <http://www.gnu.org/licenses/>.

#ifndef __H2D_EXACT_SOLUTION_H
#define __H2D_EXACT_SOLUTION_H

#include "solution.h"

namespace Hermes
{
  namespace Hermes2D
  {
    template<typename Scalar>
    class HERMES_API ExactSolution : public Solution<Scalar>
    {
    public:
      ExactSolution(const Mesh* mesh);

      virtual unsigned int get_dimension() const = 0;

      virtual MeshFunction<Scalar>* clone() const;

      inline std::string getClassName() const { return "ExactSolution"; }

    protected:
      Scalar exact_multiplicator;
      template<typename T> friend class Solution;
    };

    template<typename Scalar>
    class HERMES_API ExactSolutionScalar : public ExactSolution<Scalar>
    {
    public:
      ExactSolutionScalar(const Mesh* mesh);

      virtual unsigned int get_dimension() const;

      virtual Scalar value (double x, double y) const = 0;

      virtual void derivatives (double x, double y, Scalar& dx, Scalar& dy) const = 0;

      Scalar exact_function (double x, double y, Scalar& dx, Scalar& dy) const {
        derivatives (x, y, dx, dy);
        return value (x, y);
      };

      virtual Hermes::Ord ord(Hermes::Ord x, Hermes::Ord y) const = 0;
    };

    template<typename Scalar>
    class HERMES_API ExactSolutionVector : public ExactSolution<Scalar>
    {
    public:
      ExactSolutionVector(const Mesh* mesh);

      virtual unsigned int get_dimension() const;

      virtual Scalar2<Scalar> value (double x, double y) const = 0;

      virtual void derivatives (double x, double y, Scalar2<Scalar>& dx, Scalar2<Scalar>& dy) const = 0;

      virtual Scalar2<Scalar> exact_function(double x, double y, Scalar2<Scalar>& dx, Scalar2<Scalar>& dy) const {
        derivatives (x, y, dx, dy);
        return value (x, y);
      };

      virtual Hermes::Ord ord(Hermes::Ord x, Hermes::Ord y) const = 0;
    };
    
    template<typename Scalar>
    class HERMES_API ConstantSolution : public ExactSolutionScalar<Scalar>
    {
    public:
      ConstantSolution(const Mesh* mesh, Scalar constant);

      virtual Scalar value (double x, double y) const;

      virtual void derivatives (double x, double y, Scalar& dx, Scalar& dy) const;

      virtual Ord ord(Ord x, Ord y) const;
      virtual MeshFunction<Scalar>* clone() const;

      void save(const char* filename) const;

    protected:
      Scalar constant;
    };

    template<typename Scalar>
    class HERMES_API ZeroSolution : public ExactSolutionScalar<Scalar>
    {
    public:
      ZeroSolution(const Mesh* mesh);

      virtual Scalar value (double x, double y) const;

      virtual void derivatives (double x, double y, Scalar& dx, Scalar& dy) const;

      virtual Ord ord(Ord x, Ord y) const;
      virtual MeshFunction<Scalar>* clone() const;

      void save(const char* filename) const;
    };

    template<typename Scalar>
    class HERMES_API ConstantSolutionVector : public ExactSolutionVector<Scalar>
    {
    public:
      ConstantSolutionVector(const Mesh* mesh, Scalar constantX, Scalar constantY);

      virtual Scalar2<Scalar> value (double x, double y) const;

      virtual void derivatives (double x, double y, Scalar2<Scalar>& dx, Scalar2<Scalar>& dy) const;

      virtual Ord ord(Ord x, Ord y) const;
      virtual MeshFunction<Scalar>* clone() const;

      void save(const char* filename) const;
    protected:
      Scalar constantX;
      Scalar constantY;
    };

    template<typename Scalar>
    class HERMES_API ZeroSolutionVector : public ExactSolutionVector<Scalar>
    {
    public:
      ZeroSolutionVector(const Mesh* mesh);

      virtual Scalar2<Scalar> value (double x, double y) const;

      virtual void derivatives (double x, double y, Scalar2<Scalar>& dx, Scalar2<Scalar>& dy) const;

      virtual Ord ord(Ord x, Ord y) const;
      virtual MeshFunction<Scalar>* clone() const;

      void save(const char* filename) const;
    };
  }
}
#endif