variableselector.cpp

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 *       - Christophe GONZALES(_at_AMU)                                     *
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 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
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// =========================================================================
#include <agrum/FMDP/learning/datastructure/variableselector.h>
 
// =========================================================================
 
namespace gum {
 
  // ==========================================================================
  // Constructor & destructor.
  // ==========================================================================
 
  // ###################################################################
  // Default constructor
  // ###################################################################
  VariableSelector::VariableSelector(const gum::VariableSet& startingSet) :
      _remainingVars_(startingSet) {
    GUM_CONSTRUCTOR(VariableSelector)
    _remainingScores_.insert(0.0, 0.0);
    _remainingVarsByScore_.insert(0.0, new gum::VariableSet(_remainingVars_));
 
    for (auto varIter = _remainingVars_.cbeginSafe(); varIter != _remainingVars_.cendSafe();
         ++varIter) {
      _remainingVarsScore_.insert(*varIter, 0.0);
      _remainingVarsOtherScore_.insert(*varIter, 0.0);
    }
  }
 
  // ###################################################################
  // Default constructor
  // ###################################################################
  VariableSelector::~VariableSelector() { GUM_DESTRUCTOR(VariableSelector) }
 
  // ###################################################################
  //
  // ###################################################################
  void VariableSelector::updateScore(const DiscreteVariable* var,
                                     double                  score,
                                     double                  secondaryscore) {
    _removeVar_(var);
    _remainingVarsScore_[var] += score;
    _addVar_(var);
    _remainingVarsOtherScore_[var] += secondaryscore;
  }
 
  // ###################################################################
  //
  // ###################################################################
  void VariableSelector::downdateScore(const DiscreteVariable* var,
                                       double                  score,
                                       double                  secondaryscore) {
    _removeVar_(var);
    _remainingVarsScore_[var] -= score;
    _addVar_(var);
    _remainingVarsOtherScore_[var] -= secondaryscore;
  }
 
  // ###################################################################
  // Select the most relevant variable
  // ###################################################################
  const DiscreteVariable* VariableSelector::select() {
    double                  bestScore = _remainingScores_.top();
    const gum::VariableSet* bestSet   = _remainingVarsByScore_[bestScore];
    const DiscreteVariable* bestVar   = nullptr;
 
    for (auto varIter = bestSet->beginSafe(); varIter != bestSet->endSafe(); ++varIter) {
      if (bestVar == nullptr
          || _remainingVarsOtherScore_[bestVar] < _remainingVarsOtherScore_[*varIter]
          || (_remainingVarsOtherScore_[bestVar] == _remainingVarsOtherScore_[*varIter]
              && bestVar->domainSize() < (*varIter)->domainSize()))
        bestVar = *varIter;
    }
    _removeVar_(bestVar);
    _remainingVars_ >> bestVar;
    return bestVar;
  }
 
  // ###################################################################
  // Select the most relevant variable
  // ###################################################################
  void VariableSelector::_addVar_(const DiscreteVariable* var) {
    double varScore = _remainingVarsScore_[var];
 
    if (!_remainingVarsByScore_.exists(varScore)) {
      _remainingVarsByScore_.insert(varScore, new gum::VariableSet());
      _remainingScores_.insert(varScore, varScore);
    }
    _remainingVarsByScore_[varScore]->insert(var);
  }
 
  // ###################################################################
  // Select the most relevant variable
  // ###################################################################
  void VariableSelector::_removeVar_(const DiscreteVariable* var) {
    double            varScore = _remainingVarsScore_[var];
    gum::VariableSet* varSet   = _remainingVarsByScore_[varScore];
    *varSet >> var;
    if (varSet->empty()) {
      _remainingScores_.erase(varScore);
      _remainingVarsByScore_.erase(varScore);
      delete varSet;
    }
  }
}   // namespace gum