exact_error_estimator.h

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2014 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can 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.

// This library 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
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



#ifndef LIBMESH_EXACT_ERROR_ESTIMATOR_H
#define LIBMESH_EXACT_ERROR_ESTIMATOR_H

// Local Includes
#include "libmesh/error_estimator.h"
#include "libmesh/function_base.h"

// C++ includes
#include <cstddef>
#include <string>
#include <vector>

namespace libMesh
{

// Forward Declarations
class Elem;
template <typename T> class FEGenericBase;
typedef FEGenericBase<Real> FEBase;
class MeshFunction;
class Point;
class Parameters;

template <typename T> class DenseVector;

// Is there any way to simplify this?
// All we need are Tensor and Gradient. - RHS
template <typename T> class TensorValue;
template <typename T> class VectorValue;
typedef TensorValue<Number> NumberTensorValue;
typedef NumberTensorValue   Tensor;
typedef VectorValue<Number> NumberVectorValue;
typedef NumberVectorValue   Gradient;



class ExactErrorEstimator : public ErrorEstimator
{
public:

  ExactErrorEstimator() :
    ErrorEstimator(),
    _exact_value(NULL),
    _exact_deriv(NULL),
    _exact_hessian(NULL),
    _equation_systems_fine(NULL),
    _extra_order(0)
  { error_norm = H1; }

  ~ExactErrorEstimator() {}

  void attach_exact_values (std::vector<FunctionBase<Number> *> f);

  void attach_exact_value (unsigned int sys_num,
                           FunctionBase<Number>* f);

  void attach_exact_value ( Number fptr(const Point& p,
                                        const Parameters& Parameters,
                                        const std::string& sys_name,
                                        const std::string& unknown_name));

  void attach_exact_derivs (std::vector<FunctionBase<Gradient> *> g);

  void attach_exact_deriv (unsigned int sys_num,
                           FunctionBase<Gradient>* g);

  void attach_exact_deriv ( Gradient gptr(const Point& p,
                                          const Parameters& parameters,
                                          const std::string& sys_name,
                                          const std::string& unknown_name));

  void attach_exact_hessians (std::vector<FunctionBase<Tensor> *> h);

  void attach_exact_hessian (unsigned int sys_num,
                             FunctionBase<Tensor>* h);

  void attach_exact_hessian ( Tensor hptr(const Point& p,
                                          const Parameters& parameters,
                                          const std::string& sys_name,
                                          const std::string& unknown_name));

  void attach_reference_solution (EquationSystems* es_fine);


  void extra_quadrature_order (const int extraorder)
  { _extra_order = extraorder; }


  // Bring the base class functionality into the name lookup
  // procedure.  This allows for alternative calling formats
  // defined in the base class.  Thanks Wolfgang.
  // GCC 2.95.3 cannot compile such code.  Since it was not really
  // essential to the functioning of this class, it's been removed.
  // using ErrorEstimator::estimate_error;

  virtual void estimate_error (const System& system,
                               ErrorVector& error_per_cell,
                               const NumericVector<Number>* solution_vector = NULL,
                               bool estimate_parent_error = false);

private:

  Number (* _exact_value) (const Point& p,
                           const Parameters& parameters,
                           const std::string& sys_name,
                           const std::string& unknown_name);

  Gradient (* _exact_deriv) (const Point& p,
                             const Parameters& parameters,
                             const std::string& sys_name,
                             const std::string& unknown_name);

  Tensor (* _exact_hessian) (const Point& p,
                             const Parameters& parameters,
                             const std::string& sys_name,
                             const std::string& unknown_name);

  std::vector<FunctionBase<Number> *> _exact_values;

  std::vector<FunctionBase<Gradient> *> _exact_derivs;

  std::vector<FunctionBase<Tensor> *> _exact_hessians;

  EquationSystems* _equation_systems_fine;

  Real find_squared_element_error (const System& system,
                                   const std::string& var_name,
                                   const Elem *elem,
                                   const DenseVector<Number> &Uelem,
                                   FEBase *fe,
                                   MeshFunction *fine_values) const;

  void clear_functors ();

  int _extra_order;
};


} // namespace libMesh

#endif // LIBMESH_EXACT_ERROR_ESTIMATOR_H