// -------------------------------------------------------------------------
// @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
// -------------------------------------------------------------------------

#ifndef __CPPLUGINS__EXTENSIONS__ALGORITHMS__ITERATIVEGAUSSIANMODELESTIMATOR__H__
#define __CPPLUGINS__EXTENSIONS__ALGORITHMS__ITERATIVEGAUSSIANMODELESTIMATOR__H__

#include <vector>
#include <itkConceptChecking.h>
#include <itkObject.h>
#include <vnl/vnl_matrix.h>

namespace cpPlugins
{
  namespace Extensions
  {
    namespace Algorithms
    {
      /**
       */
      template< class S, unsigned int D >
      class IterativeGaussianModelEstimator
        : public itk::Object
      {
      public:
        typedef IterativeGaussianModelEstimator Self;
        typedef itk::Object                     Superclass;
        typedef itk::SmartPointer< Self >       Pointer;
        typedef itk::SmartPointer< const Self > ConstPointer;

        typedef S TScalar;
        itkStaticConstMacro( Dimension, unsigned int, D );

        // Begin concept checking
#ifdef ITK_USE_CONCEPT_CHECKING
        itkConceptMacro(
          ScalarTypeHasFloatResolution,
          ( itk::Concept::IsFloatingPoint< S > )
          );
#endif
        // End concept checking

        typedef vnl_matrix< S >        TMatrix;
        typedef std::vector< TMatrix > TMatrices;

      public:
        itkNewMacro( Self );
        itkTypeMacro( IterativeGaussianModelEstimator, itkObject );

        itkGetConstMacro( MinimumProbability, S );
        itkGetConstMacro( MaximumProbability, S );

      public:
        unsigned long GetNumberOfSamples( ) const
          { return( this->m_Samples.size( ) ); }

        void UpdateModel( );

        template< class V >
        S Probability( const V& sample ) const;

        S Probability( const S& s_x, const S& s_y, ... ) const;

        template< class V, class M >
        void GetModel( V& m, M& E ) const;

        void Clear( );

        template< class V >
        void AddSample( const V& sample );

        void AddSample( const S& s_x, const S& s_y, ... );

      protected:
        IterativeGaussianModelEstimator( );
        virtual ~IterativeGaussianModelEstimator( );

      private:
        // Purposely not implemented
        IterativeGaussianModelEstimator( const Self& other );
        void operator=( const Self& other );

      protected:
        TMatrix   m_S1;
        TMatrix   m_S2;
        TMatrices m_Samples;

        bool m_Updated;
        TMatrix m_Cov;
        TMatrix m_Mean;
        TMatrix m_InvCov;
        S m_DensityCoeff;

        S m_MinimumProbability;
        S m_MaximumProbability;
      };

    } // ecapseman

  } // ecapseman

} // ecapseman

#include <cpPlugins/Extensions/Algorithms/IterativeGaussianModelEstimator.hxx>

#endif // __CPPLUGINS__EXTENSIONS__ALGORITHMS__ITERATIVEGAUSSIANMODELESTIMATOR__H__

// eof - $RCSfile$