gum::Chi2TestPolicy< GUM_SCALAR > Class Template Reference

<agrum/tools/multidim/core/testPolicy/Chi2TestPolicy.h> More...

#include <Chi2TestPolicy.h>

Inheritance diagram for gum::Chi2TestPolicy< GUM_SCALAR >:

Collaboration diagram for gum::Chi2TestPolicy< GUM_SCALAR >:

Public Member Functions
	Chi2TestPolicy ()
virtual	~Chi2TestPolicy ()
void *	operator new (size_t s)
	Allocators and Deallocators redefinition. More...
void	operator delete (void *p)
const ContingencyTable< Idx, GUM_SCALAR > &	ct () const
void	add (const Chi2TestPolicy< GUM_SCALAR > &src)
std::string	toString () const
Observation insertion
void	addObservation (Idx attr, GUM_SCALAR value)
	Comptabilizes the new observation. More...
Test relevance
bool	isTestRelevant () const
	Returns true if enough observation were made so that the test can be relevant. More...
Test result
void	computeScore () const
	Recomputes the statistic from the beginning. More...
double	score () const
	Returns the performance of current variable according to the test. More...
virtual double	secondaryscore () const
	Returns a second criterion to severe ties. More...
Observation methods
Idx	nbObservation () const
	Comptabilizes the new observation. More...
Fusion Methods
void	add (const ITestPolicy< GUM_SCALAR > &src)

Protected Member Functions
bool	isModified_ () const

Detailed Description

template<typename GUM_SCALAR>
class gum::Chi2TestPolicy< GUM_SCALAR >

<agrum/tools/multidim/core/testPolicy/Chi2TestPolicy.h>

Chi2TestPolicy implements a test policy that follows the Chi2 statistic

Definition at line 51 of file Chi2TestPolicy.h.

Constructor & Destructor Documentation

Chi2TestPolicy()

template<typename GUM_SCALAR >

gum::Chi2TestPolicy< GUM_SCALAR >::Chi2TestPolicy ( )

inline

Definition at line 53 of file Chi2TestPolicy.h.

                     : ITestPolicy< GUM_SCALAR >(), _conTab_(), _chi2Score_(0) {
      GUM_CONSTRUCTOR(Chi2TestPolicy);
    }

~Chi2TestPolicy()

template<typename GUM_SCALAR >

virtual gum::Chi2TestPolicy< GUM_SCALAR >::~Chi2TestPolicy ( )

inlinevirtual

Definition at line 57 of file Chi2TestPolicy.h.

                              {
      GUM_DESTRUCTOR(Chi2TestPolicy);
      ;
    }

Member Function Documentation

add() [1/2]

template<typename GUM_SCALAR >

void gum::Chi2TestPolicy< GUM_SCALAR >::add

(

const Chi2TestPolicy< GUM_SCALAR > &

src

)

Definition at line 97 of file Chi2TestPolicy_tpl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                                {
    ITestPolicy< GUM_SCALAR >::add(src);
    _conTab_ += src.ct();
  }

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add() [2/2]

template<typename GUM_SCALAR >

void gum::ITestPolicy< GUM_SCALAR >::add ( const ITestPolicy< GUM_SCALAR > &  src )

inlineinherited

Definition at line 139 of file ITestPolicy.h.

References gum::ITestPolicy< GUM_SCALAR >::_isModified_.

                                                   {
      _isModified_ = true;
      _nbObs_ += src.nbObservation();
    }

addObservation()

template<typename GUM_SCALAR >

void gum::Chi2TestPolicy< GUM_SCALAR >::addObservation ( Idx  attr, GUM_SCALAR  value  )

virtual

Comptabilizes the new observation.

Reimplemented from gum::ITestPolicy< GUM_SCALAR >.

Definition at line 44 of file Chi2TestPolicy_tpl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                                {
    ITestPolicy< GUM_SCALAR >::addObservation(iattr, ivalue);
    _conTab_.add(iattr, ivalue);
  }

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computeScore()

template<typename GUM_SCALAR >

void gum::Chi2TestPolicy< GUM_SCALAR >::computeScore ( ) const

virtual

Recomputes the statistic from the beginning.

Reimplemented from gum::ITestPolicy< GUM_SCALAR >.

Definition at line 58 of file Chi2TestPolicy_tpl.h.

References gum::Set< Key, Alloc >::emplace().

                                                        {
    ITestPolicy< GUM_SCALAR >::computeScore();
    _chi2Score_ = 0;
    for (auto attrIter = _conTab_.attrABeginSafe(); attrIter != _conTab_.attrAEndSafe();
         ++attrIter) {
      double semiExpected = (double)(attrIter.val()) / (double)this->nbObservation();
      for (auto valIter = _conTab_.attrBBeginSafe(); valIter != _conTab_.attrBEndSafe();
           ++valIter) {
        double cell = (double)_conTab_.joint(attrIter.key(), valIter.key());
        if (cell < 5) continue;
        double expected = semiExpected * (double)(valIter.val());

        _chi2Score_ += std::pow(cell - expected, 2.0) / expected;
      }
    }
  }

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ct()

template<typename GUM_SCALAR >

const ContingencyTable< Idx, GUM_SCALAR >& gum::Chi2TestPolicy< GUM_SCALAR >::ct ( ) const

inline

Definition at line 121 of file Chi2TestPolicy.h.

{ return _conTab_; }

isModified_()

template<typename GUM_SCALAR >

bool gum::ITestPolicy< GUM_SCALAR >::isModified_ ( ) const

inlineprotectedinherited

Definition at line 164 of file ITestPolicy.h.

References gum::ITestPolicy< GUM_SCALAR >::_isModified_.

{ return _isModified_; }

isTestRelevant()

template<typename GUM_SCALAR >

bool gum::Chi2TestPolicy< GUM_SCALAR >::isTestRelevant ( ) const

inlinevirtual

Returns true if enough observation were made so that the test can be relevant.

Implements gum::ITestPolicy< GUM_SCALAR >.

Definition at line 92 of file Chi2TestPolicy.h.

                                {
      return (this->nbObservation() > 20 && this->nbObservation() > _conTab_.attrASize() * 5);
    }

nbObservation()

template<typename GUM_SCALAR >

Idx gum::ITestPolicy< GUM_SCALAR >::nbObservation ( ) const

inlineinherited

Comptabilizes the new observation.

Definition at line 97 of file ITestPolicy.h.

{ return _nbObs_; }

operator delete()

template<typename GUM_SCALAR >

void gum::Chi2TestPolicy< GUM_SCALAR >::operator delete ( void *  p )

inline

Definition at line 66 of file Chi2TestPolicy.h.

                                   {
      SmallObjectAllocator::instance().deallocate(p, sizeof(Chi2TestPolicy));
    }

operator new()

template<typename GUM_SCALAR >

void* gum::Chi2TestPolicy< GUM_SCALAR >::operator new ( size_t  s )

inline

Allocators and Deallocators redefinition.

Definition at line 65 of file Chi2TestPolicy.h.

{ return SmallObjectAllocator::instance().allocate(s); }

score()

template<typename GUM_SCALAR >

double gum::Chi2TestPolicy< GUM_SCALAR >::score ( ) const

virtual

Returns the performance of current variable according to the test.

Implements gum::ITestPolicy< GUM_SCALAR >.

Definition at line 79 of file Chi2TestPolicy_tpl.h.

References gum::Set< Key, Alloc >::emplace().

                                                   {
    if (this->isModified_()) computeScore();
    double score
       = 1
       - ChiSquare::probaChi2(_chi2Score_, (_conTab_.attrASize() - 1) * (_conTab_.attrBSize() - 1));
    return score;
  }

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secondaryscore()

template<typename GUM_SCALAR >

double gum::Chi2TestPolicy< GUM_SCALAR >::secondaryscore ( ) const

virtual

Returns a second criterion to severe ties.

Implements gum::ITestPolicy< GUM_SCALAR >.

Definition at line 91 of file Chi2TestPolicy_tpl.h.

References gum::Set< Key, Alloc >::emplace().

                                                            {
    if (this->isModified_()) computeScore();
    return _chi2Score_;
  }

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toString()

template<typename GUM_SCALAR >

std::string gum::Chi2TestPolicy< GUM_SCALAR >::toString ( ) const

inline

Definition at line 125 of file Chi2TestPolicy.h.

                               {
      std::stringstream ss;
      ss << ITestPolicy< GUM_SCALAR >::toString() << "\t\t\tContingency Table : " << std::endl
         << _conTab_.toString() << std::endl
         << "\t\t\tGStat : " << this->score() << std::endl
         << "\t\t\tGStat : " << this->secondaryscore() << std::endl;
      return ss.str();
    }

Member Data Documentation

_chi2Score_

template<typename GUM_SCALAR >

double gum::Chi2TestPolicy< GUM_SCALAR >::_chi2Score_

mutableprivate

Definition at line 138 of file Chi2TestPolicy.h.

_conTab_

template<typename GUM_SCALAR >

ContingencyTable< Idx, GUM_SCALAR > gum::Chi2TestPolicy< GUM_SCALAR >::_conTab_

private

The contingency table used to keeps records of all observation.

Definition at line 136 of file Chi2TestPolicy.h.

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The documentation for this class was generated from the following files:

• agrum/FMDP/learning/core/testPolicy/Chi2TestPolicy.h
• agrum/FMDP/learning/core/testPolicy/Chi2TestPolicy_tpl.h