GTestPolicy_tpl.h

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/***************************************************************************
 *   Copyright (C) 2005 by Christophe GONZALES and Pierre-Henri WUILLEMIN  *
 *   {prenom.nom}_at_lip6.fr                                               *
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 ***************************************************************************/
// =========================================================================
#include <agrum/core/math/math.h>
#include <agrum/FMDP/learning/core/testPolicy/GTestPolicy.h>
// =========================================================================


namespace gum {


  // ##########################################################################
  //
  // ##########################################################################

  // ==========================================================================
  //
  // ==========================================================================
  template < typename GUM_SCALAR >
  void GTestPolicy< GUM_SCALAR >::addObservation(Idx iattr, GUM_SCALAR ivalue) {
    ITestPolicy< GUM_SCALAR >::addObservation(iattr, ivalue);
    __conTab.add(iattr, ivalue);
  }


  // ############################################################################
  // @name Test result
  // ############################################################################

  // ============================================================================
  // Computes the GStat of current variable according to the test
  // ============================================================================
  template < typename GUM_SCALAR >
  void GTestPolicy< GUM_SCALAR >::computeScore() const {
    ITestPolicy< GUM_SCALAR >::computeScore();
    __GStat = 0;

    // Itération sur l'axe 1 du tableau
    for (auto attrIter = __conTab.attrABeginSafe();
         attrIter != __conTab.attrAEndSafe();
         ++attrIter) {
      // Mise en cache de valeur utile
      double semiExpected =
         (double)(attrIter.val()) / (double)this->nbObservation();

      // Itération sur l'axe 2 du tableau
      for (auto valIter = __conTab.attrBBeginSafe();
           valIter != __conTab.attrBEndSafe();
           ++valIter) {
        // Récupération de la valeur en cellule
        Idx cell = __conTab.joint(attrIter.key(), valIter.key());
        if (cell < 5) continue;

        // Récupération de la valeur en axe 2
        double expected = semiExpected * (double)valIter.val();

        __GStat += 2 * cell * log(cell / expected);
      }
    }
  }

  // ============================================================================
  // Returns the performance of current variable according to the test
  // ============================================================================
  template < typename GUM_SCALAR >
  double GTestPolicy< GUM_SCALAR >::score() const {
    if (this->_isModified()) computeScore();
    //      std::cout << this->toString() << std::endl;
    double score =
       1
       - ChiSquare::probaChi2(
            __GStat, (__conTab.attrASize() - 1) * (__conTab.attrBSize() - 1));
    return score;
  }

  // ============================================================================
  // Returns a second criterion to severe ties
  // ============================================================================
  template < typename GUM_SCALAR >
  double GTestPolicy< GUM_SCALAR >::secondaryscore() const {
    if (this->_isModified()) computeScore();
    return __GStat;
  }

  template < typename GUM_SCALAR >
  void GTestPolicy< GUM_SCALAR >::add(const GTestPolicy< GUM_SCALAR >& src) {
    ITestPolicy< GUM_SCALAR >::add(src);
    __conTab += src.ct();
  }

}   // End of namespace gum