PAMClustering.h

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/******************************************************************************
 *
 *  Copyright (C) 2008 Max Hermann
 *
 *  This file is part of the "CEDRIC Event Display" application.
 *
 *****************************************************************************/

#ifndef REDUKT_PAMCLUSTERING_H
#define REDUKT_PAMCLUSTERING_H

#include <vector>
#include <boost/numeric/ublas/symmetric.hpp>
namespace ublas = boost::numeric::ublas;

// Determine minimum cost swap by really calculating objective function.
// This is needed as long as there is this nasty bug in the more efficient cost-update code.
#define PAMCLUSTERING_BRUTE_FORCE

class PAMClustering
{
public:
        typedef ublas::symmetric_matrix<double,ublas::lower> matrix_type;
        typedef std::vector<unsigned int> ivec;
        typedef std::vector<double> dvec;

        PAMClustering( const matrix_type& d, unsigned int k );
        ~PAMClustering();
        
        PAMClustering( PAMClustering& other );

        int cluster( unsigned int maxIterations=10000 );

        double calcSilhouette();
        double silCluster( unsigned int c );
        const dvec& sils() const { return m_sil; }

        const ivec& labels()  const { return m_labels; };
        const ivec& medoids() const { return m_medoids; }
        
        unsigned int numClusters() const { return K; }

protected:
        void label();
        
        bool swap();

        bool isSelected( unsigned int i );

        double avgDist( unsigned int i, unsigned int c );


#ifdef PAMCLUSTERING_BRUTE_FORCE
        // returns objective value of clustering using m_medoids
        // in contrast to label() here is not acted on member m_labels but given reference
        double PAMClustering::label( ivec& labels );
#endif
        
private:
        // assignment not possible because of const Reference D member
        PAMClustering& operator = ( PAMClustering& other );

        const matrix_type& D;
        unsigned int N;
        unsigned int K;

        ivec  m_medoids;
        ivec  m_labels;
        ivec  m_second;
        ivec* m_clusters;

        ivec  m_selected;    
        double m_objective;  
        
        dvec  m_sil;         
        double m_silTotal;   
};

#endif