source: trunk/c++_tools/classifier/FeatureSelector.h @ 675

#ifndef _theplu_classifier_featureselector_
#define _theplu_classifier_featureselector_

// $Id$

/*
  Copyright (C) The authors contributing to this file.

  This file is part of the yat library, http://lev.thep.lu.se/trac/yat

  The yat library 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.

  The yat 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
  General Public License for more details.

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

#include <list>
#include <vector>

namespace theplu {
namespace classifier {
  class MatrixLookup;
  class MatrixLookupWeighted;
  class Target;

  ///
  /// @brief Interface class for FeatureSelection
  ///
  class FeatureSelector
  {
  public:
    /// 
    /// @brief Default Constructor 
    /// 
    FeatureSelector(size_t N, size_t skip=0);

    /// 
    /// Cleaning upp all objects that have beed returned from FeatureSelector.
    ///
    /// @brief Destructor
    /// 
    virtual ~FeatureSelector(void);

    ///
    /// @return MatrixLookup containing only selected features. 
    ///
    const MatrixLookup& get(const MatrixLookup& data);

    ///
    /// @return MatrixLookupWeighted containing only selected features. 
    ///
    const MatrixLookupWeighted& get(const MatrixLookupWeighted& data);

    ///
    /// @return vector of indices corresponding to selected features.
    ///
    inline const std::vector<size_t> features(void) const { return features_; }

    ///
    /// Uses @a matrix to select features.
    ///
    virtual void update(const MatrixLookup& matrix, const Target& target)=0;

    ///
    /// Uses @a matrix to select features.
    ///
    virtual void update(const MatrixLookupWeighted& matrix, 
                        const Target& target)=0;

  protected:
    ///
    /// @brief features
    ///
    std::vector<size_t> features_;

    ///
    /// number of features to skip in list
    ///
    size_t first_;

    ///
    /// number of features selected and returned
    ///
    size_t N_;

  private:
    std::list<const MatrixLookup*> garbage_;
    std::list<const MatrixLookupWeighted*> garbage_weighted_;

  };

} // end of namespace classifier
} // end of namespace theplu

#endif