patch_recovery_error_estimator.h

一个用来实现偏微分方程中网格的计算库

// $Id: patch_recovery_error_estimator.h 2868 2008-06-16 17:00:33Z 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 __patch_recovery_error_estimator_h__
#define __patch_recovery_error_estimator_h__

// C++ includes
#include <vector>

// Local Includes
#include "error_estimator.h"
#include "enum_order.h"
#include "patch.h"
#include "point.h"
#include "elem_range.h"

// Forward Declarations
class Elem;


/**
 * This class implements the Patch Recovery error indicator.
 * 
 *
 * @author Varis Carey, Benjamin S. Kirk, 2004.
 */
class PatchRecoveryErrorEstimator : public ErrorEstimator
{
public:

  /**
   * Constructor.
   */
  PatchRecoveryErrorEstimator() :
    target_patch_size(20),
    patch_growth_strategy(&Patch::add_local_face_neighbors) {}
  
  /**
   * Destructor.  
   */
  ~PatchRecoveryErrorEstimator() {}


  /**
   * This function uses the Patch Recovery error
   * estimate to estimate the error on each cell.
   * The estimated error is output in the vector
   * \p error_per_cell
   */
  virtual void estimate_error (const System& system,
			       ErrorVector& error_per_cell,
			       bool estimate_parent_error = false);

  /**
   * The PatchErrorEstimator will build patches of at least this many
   * elements to perform estimates
   */
  unsigned int target_patch_size;

  /**
   * The PatchErrorEstimator will use this pointer to a Patch member
   * function when growing patches.  The default strategy used is
   * Patch::add_local_face_neighbors.
   * Patch::add_local_point_neighbors may be more reliable but slower.
   */
  Patch::PMF patch_growth_strategy;

private:

  /**
   * Returns the spectral polynomial basis function values at a point x,y,z
   */
  
  static std::vector<Real> specpoly(const unsigned int dim,
				    const Order order,
				    const Point p,
				    const unsigned int matsize);

  /**
   * Class to compute the error contribution for a range
   * of elements. May be executed in parallel on separate threads.
   */
  class EstimateError
  {
  public:
    EstimateError (const System& sys,
		   const PatchRecoveryErrorEstimator &ee,
		   ErrorVector& epc) :
      system(sys),
      error_estimator(ee),
      error_per_cell(epc)
    {}

    void operator()(const ConstElemRange &range) const;
    
  private:

    const System &system;
    const PatchRecoveryErrorEstimator &error_estimator;
    ErrorVector &error_per_cell;    
  };

  friend class EsitmateError;
};



#endif // #define __patch_recovery_error_estimator_h__