/** 
* @file SpectralCluster.h
* @brief spectral clustering by kmeans-clustering of eigenvectors
* @author Erik Rodner, Alexander Freytag
* @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:
      
    ///////////////////// ///////////////////// /////////////////////
    //                   CONSTRUCTORS / DESTRUCTORS
    ///////////////////// ///////////////////// ///////////////////// 

    /** 
     * @brief default constructor
     * @date 12-02-2014 (dd-mm-yyyy )
     * @author Alexander Freytag
     */
    SpectralCluster ( );       
  
    /** 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();
      
    /** 
     * @brief Jobs previously performed in the config-version of the constructor, read settings etc.
     * @author Alexander Freytag
     * @date 12-02-2014 ( dd-mm-yyyy )
     */    
    void initFromConfig ( const NICE::Config * _conf, const std::string & _confSection = "SpectralCluster");     
    
    ///////////////////// ///////////////////// /////////////////////
    //                      CLUSTERING STUFF
    ///////////////////// ///////////////////// //////////////////       
        
    void cluster ( const NICE::VVector & features,
            NICE::VVector & prototypes,
            std::vector<double> & weights,
            std::vector<int>    & assignment );
        
      
    ///////////////////// INTERFACE PERSISTENT /////////////////////
    // interface specific methods for store and restore
    ///////////////////// INTERFACE PERSISTENT /////////////////////      
    
    /**
    * @brief Load object from external file (stream)
    * @author Alexander Freytag
    * @date 12-02-2014 ( dd-mm-yyyy )
    */
    void restore ( std::istream & is, int format = 0 );

    /**
    * @brief Save object to external file (stream)
    * @author Alexander Freytag
    * @date 12-02-2014 ( dd-mm-yyyy )
    */
    void store ( std::ostream & os, int format = 0 ) const;

    /**
    * @brief Clear object
    * @author Alexander Freytag
    * @date 12-02-2014 ( dd-mm-yyyy )
    */
    void clear ();           

  };


} // namespace

#endif