/********************************************************************
**                Image Component Library (ICL)                    **
**                                                                 **
** Copyright (C) 2006-2012 CITEC, University of Bielefeld          **
**                         Neuroinformatics Group                  **
** Website: www.iclcv.org and                                      **
**          http://opensource.cit-ec.de/projects/icl               **
**                                                                 **
** File   : include/ICLMath/VQ2D.h                                 **
** Module : ICLMath                                                **
** Authors: Christof Elbrechter                                    **
**                                                                 **
**                                                                 **
** Commercial License                                              **
** ICL can be used commercially, please refer to our website       **
** www.iclcv.org for more details.                                 **
**                                                                 **
** GNU General Public License Usage                                **
** Alternatively, this file may be used under the terms of the     **
** GNU General Public License version 3.0 as published by the      **
** Free Software Foundation and appearing in the file LICENSE.GPL  **
** included in the packaging of this file.  Please review the      **
** following information to ensure the GNU General Public License  **
** version 3.0 requirements will be met:                           **
** http://www.gnu.org/copyleft/gpl.html.                           **
**                                                                 **
** The development of this software was supported by the           **
** Excellence Cluster EXC 277 Cognitive Interaction Technology.    **
** The Excellence Cluster EXC 277 is a grant of the Deutsche       **
** Forschungsgemeinschaft (DFG) in the context of the German       **
** Excellence Initiative.                                          **
**                                                                 **
*********************************************************************/

#pragma once

#include <stdlib.h>
#include <ICLMath/VQVectorSet.h>
#include <ICLMath/VQClusterInfo.h>
#include <ICLUtils/Time.h>

namespace icl{
  namespace math{
    /// Support class for 2-Dimensional vector quatisation using KMeans \ingroup G_UTILS
    /** Vector Quantisation is internally applied using the <b>KMeans</b> algorithm
        which can be defines as follows:
        
        <pre>
        Given data set D of |D| elements with D = d_1,...,d_|D|
        Given center count K with 
        Optionally given data set C = c1,..,cK of initial centers (prototypes) of size |C|=K
        
        algorithm:
        
        for i = 1 to MAX-STEPS do
           for k = 1 to K
              Vc : = { di | |di-ck| < |di-co| for all o!=k } ( Voronoi cell for center c )
           endfor
  
           for k = 1 to K
              ck := mean(Vc)
           endfor
        
           // current quatisation is given by the set of centers C
           
           if current quatisation error < minError 
              break
           endif
        endfor
        </pre>
        
    **/
    class VQ2D{
      public:
      
      /// create a new VQ
      VQ2D(float *data=0, int dim=0, bool deepCopyData = false);
      
      /// data will be copied once
      void setData(float *data, int dim, bool deepCopy = false);
      
      /// retruns just the center information
      /** @param centers count of prototypes to use 
          @param steps count of steps to perform 
          @param mmqe mininum mean qauntisation error 
          @param qe quantisation error */
      const VQVectorSet &run(int centers, int steps, float mmqe, float &qe);
      
      /// calculates advanced features like local pca
      const VQClusterInfo &features();
  
      /// return the centers of all clusters
      const VQVectorSet &centers();
      
      protected:
      VQVectorSet *m_poCenters;       ///!< center data
      VQClusterInfo *m_poClusterInfo; ///!< additinal cluster information
      VQVectorSet *m_poData;          ///!< data
    };
  } // namespace cv
}