itkExpectationMaximizationMixtureModelEstimator.h

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/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkExpectationMaximizationMixtureModelEstimator.h,v $
  Language:  C++
  Date:      $Date: 2005-07-26 15:54:55 $
  Version:   $Revision: 1.12 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef __itkExpectationMaximizationMixtureModelEstimator_h
#define __itkExpectationMaximizationMixtureModelEstimator_h

#include "itkMembershipFunctionBase.h"
#include "itkMixtureModelComponentBase.h"

namespace itk{ 
namespace Statistics{

template< class TSample >
class ITK_EXPORT ExpectationMaximizationMixtureModelEstimator : public Object
{
public:
  typedef ExpectationMaximizationMixtureModelEstimator Self;
  typedef Object Superclass;
  typedef SmartPointer< Self > Pointer;
  typedef SmartPointer<const Self> ConstPointer;

  itkTypeMacro(ExpectationMaximizationMixtureModelEstimator,
               Object);
  itkNewMacro(Self) ;

  typedef typename TSample::MeasurementType MeasurementType ;
  typedef typename TSample::MeasurementVectorType MeasurementVectorType ;

  typedef MixtureModelComponentBase< TSample > ComponentType ;

  typedef std::vector< ComponentType* > ComponentVectorType ;

  typedef MembershipFunctionBase< MeasurementVectorType > 
  ComponentMembershipFunctionType ;

  typedef Array< double > ProportionVectorType ;

  void SetSample(const TSample* sample) ;

  const TSample* GetSample() const;

  void SetInitialProportions(ProportionVectorType &propotion) ;
  ProportionVectorType* GetInitialProportions() ;

  ProportionVectorType* GetProportions() ;

  void SetMaximumIteration(int numberOfIterations) ;
  int GetMaximumIteration() ;

  int GetCurrentIteration() 
  { return m_CurrentIteration ; }

  int AddComponent(ComponentType* component) ;

  unsigned int GetNumberOfComponents() ;

  void Update() ;

  enum TERMINATION_CODE { CONVERGED = 0, NOT_CONVERGED = 1 } ;

  TERMINATION_CODE GetTerminationCode() ;

  ComponentMembershipFunctionType* GetComponentMembershipFunction(int componentIndex) ;

protected:
  ExpectationMaximizationMixtureModelEstimator() ;
  virtual ~ExpectationMaximizationMixtureModelEstimator() {}
  void PrintSelf(std::ostream& os, Indent indent) const ;

  bool CalculateDensities() ;
  double CalculateExpectation() ;
  bool UpdateComponentParameters() ;
  bool UpdateProportions() ;

  void GenerateData() ;

private:
  const TSample* m_Sample ;

  int m_MaxIteration ;
  int m_CurrentIteration ;
  TERMINATION_CODE m_TerminationCode ;
  ComponentVectorType m_ComponentVector ;
  ProportionVectorType m_InitialProportions ;
  ProportionVectorType m_Proportions ;
} ; // end of class


} // end of namespace Statistics 
} // end of namespace itk


#ifndef ITK_MANUAL_INSTANTIATION
#include "itkExpectationMaximizationMixtureModelEstimator.txx"
#endif

#endif