discontinuity_measure.h

一个用来实现偏微分方程中网格的计算库

// $Id: discontinuity_measure.h 2501 2007-11-20 02:33:29Z benkirk $

// The libMesh Finite Element Library.
// Copyright (C) 2002-2007  Benjamin S. Kirk, John W. Peterson
  
// 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 __discontinuity_measure_h___
#define __discontinuity_measure_h__

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

// Local Includes
#include "jump_error_estimator.h"

// Forward Declarations
class Point;





/**
 * This class measures discontinuities between elements
 * for debugging purposes.  It derives from ErrorEstimator
 * just in case someone finds it useful in a DG framework.
 *
 * @author Roy H. Stogner, 2006.
 */
class DiscontinuityMeasure : public JumpErrorEstimator
{
public:

  /**
   * Constructor.  Responsible for initializing the _bc_function function
   * pointer to NULL.
   */
  DiscontinuityMeasure() : _bc_function(NULL) {}
  
  /**
   * Destructor.  
   */
  ~DiscontinuityMeasure() {}

  /**
   * Register a user function to use in computing the essential BCs.
   * The return value is std::pair<bool, Real>
   */
  void attach_essential_bc_function (std::pair<bool,Real> fptr(const System& system,
							       const Point& p,
							       const std::string& var_name));
  
protected:

  /**
   * An initialization function, for requesting specific data from the FE
   * objects
   */
  virtual void initialize(const System& system,
                          ErrorVector& error_per_cell,
                          bool estimate_parent_error);

  /**
   * The function which calculates a normal derivative jump based error
   * term on an internal side
   */
  virtual void internal_side_integration();

  /**
   * The function which calculates a normal derivative jump based error
   * term on a boundary side.
   * Returns true if the flux bc function is in fact defined on the current side.
   */
  virtual bool boundary_side_integration();

  /**
   * A pointer to the current System
   */
  const System *my_system;

  /**
   * Pointer to function that returns BC information.
   */
  std::pair<bool,Real> (* _bc_function) (const System& system,
					 const Point& p,
					 const std::string& var_name);
};


#endif