/** 
* @file SpectralCluster.h
* @brief spectral clustering by kmeans-clustering of eigenvectors
* @author Erik Rodner
* @date 11/13/2007

*/
#ifndef SPECTRALCLUSTERINCLUDE
#define SPECTRALCLUSTERINCLUDE

#include <core/vector/VectorT.h>
#include <core/vector/MatrixT.h>

#include "ClusterAlgorithm.h"
#include "KMeans.h"


namespace OBJREC {

  /** spectral clustering by kmeans-clustering of eigenvectors */
  class SpectralCluster : public ClusterAlgorithm
  {

      protected:
        int noClusters;
        double alpha;

        KMeans kmeans;

        enum {
            L_UNNORMALIZED  = 0,
            L_RW_NORMALIZED 
        };

        virtual void computeLaplacian ( const NICE::VVector & features,
                NICE::Matrix & laplacian,
                int method, double alpha );


        virtual void getSimilarityMatrix ( const NICE::VVector & features, 
                    NICE::Matrix & laplacian, double alpha );
      public:
    
        /** simple constructor */
        SpectralCluster (int _noClusters, double alpha);
        
        /**
        * @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: SpectralCluster)
        * @date 14-06-2013 (dd-mm-yyyy)
        * @author Alexander Freytag
        */
        SpectralCluster( const NICE::Config *conf, const std::string & _section = "SpectralCluster");     
            
        /** simple destructor */
        virtual ~SpectralCluster();
          
        void cluster ( const NICE::VVector & features,
                NICE::VVector & prototypes,
                std::vector<double> & weights,
                std::vector<int>    & assignment );

  };


} // namespace

#endif