/** 
 * @file KMeansHeuristic.h
 * @brief K-Means
 * @author Erik Rodner, Michael Koch, Michael Trummer
 * @date 02/04/2011

 */
#ifndef KMeansHeuristicINCLUDE
#define KMeansHeuristicINCLUDE

#include <core/basics/Config.h>
#include <core/vector/Distance.h>
#include "core/vector/VectorT.h"
#include "core/vector/MatrixT.h"

#include "ClusterAlgorithm.h"


namespace OBJREC
{

  /** K-Means (but what does Heuristic actually mean? )*/
  class KMeansHeuristic: public ClusterAlgorithm
  {

  protected:
    int noClusters;
    std::string distanceType;
    NICE::VectorDistance<double> *distancefunction;
    
    double compute_assignments(const NICE::VVector & features,
        const NICE::VVector & prototypes, std::vector<int> & assignment);

    double compute_weights(const NICE::VVector & features,
        std::vector<double> & weights, std::vector<int> & assignment);

    double compute_delta(const NICE::VVector & oldprototypes,
        const NICE::VVector & prototypes);


    void initial_guess(const NICE::VVector & features, NICE::VVector & prototypes);

    void print_iteration(int iterations, NICE::VVector & prototypes, double delta);
    int robust_prototypes(const NICE::VVector &features, NICE::VVector &prototypes, std::vector<
        double> & weights, const std::vector<int> & assignment);
  public:

    /** simple constructor */
    KMeansHeuristic(int noClusters, std::string distanceMode = "euclidean");
    
    /**
    * @brief standard constructor
    * @param conf config file specifying all relevant variable settings
    * @param _section name of the section within the configfile where the settings can be found (default: KMeansHeuristic)
    * @date 14-06-2013 (dd-mm-yyyy)
    * @author Alexander Freytag
    */
    KMeansHeuristic( const NICE::Config *conf, const std::string & _section = "KMeansHeuristic");    

    /** simple destructor */
    virtual ~KMeansHeuristic();

    void cluster(const NICE::VVector & features, NICE::VVector & prototypes, std::vector<double> & weights, std::vector<int> & assignment);

  };

} // namespace

#endif