source: trunk/yat/classifier/KNN_ReciprocalRank.h @ 2986

#ifndef theplu_yat_classifier_knn_reciprocal_rank_h
#define theplu_yat_classifier_knn_reciprocal_rank_h

// $Id: KNN_ReciprocalRank.h 2986 2013-02-18 08:07:44Z peter $

/*
  Copyright (C) 2008 Jari Häkkinen, Peter Johansson, Markus Ringnér
  Copyright (C) 2013 Jari Häkkinen

  This file is part of the yat library, http://dev.thep.lu.se/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 3 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 yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include <cstddef>
#include <vector>

namespace theplu {
namespace yat {
  
  namespace utility {
    class VectorBase;
    class VectorMutable;
  }

namespace classifier {

  class Target;
  

  ///
  /// @brief A model of the concept \ref concept_neighbor_weighting to
  /// be used with KNN to weight the votes of the k nearest neighbors
  /// of a sample. 
  ///
  /// KNN_ReciprocalRank weights the vote of a nearest neighbor with
  /// its reciprocal rank. The class of the nearest neighbor gets
  /// the vote 1/1, the class of the second nearest neighbor gets the
  /// vote 1/2, and so on
  ///
  struct KNN_ReciprocalRank
  {   
    /**
       The total vote for each class is calculated and returned in prediction.
    */
    void operator()(const utility::VectorBase& distance,
                    const std::vector<size_t>& k_sorted,
                    const Target& target, 
                    utility::VectorMutable& prediction) const;    
  };

}}} // of namespace classifier, yat, and theplu
    
#endif