C45Algorithm.h

// Copyright QED Software 2023.
 
#ifndef GRAIL_C45_ALGORITHM_H
#define GRAIL_C45_ALGORITHM_H
 
#include <memory>
#include <unordered_set>
#include "C45IterationParameters.h"
#include "C45ValueDecisionCounter.h"
#include "Dataset.hh"
#include "../DecisionTree/DecisionNode.h"
 
namespace grail
{
namespace simgames
{
 class ISimulatedGameAction;
 
namespace learn
{
 class C45Algorithm
 {
 public:
 std::unique_ptr<dt::DecisionNode<ISimulatedGameAction>> ConstructTree(
 Dataset& dataset,
 int maxDepth = dt::decisionTreeMaxDepth);
 
 const std::unordered_set<int>& GetUsedColumns() const;
 
 private:
 void RunForContinuousColumn(size_t column, double globalEntropy, C45IterationParameters& params);
 void RunForNominalColumn(size_t column, double globalEntropy, C45IterationParameters& params);
 std::unique_ptr<dt::DecisionNode<ISimulatedGameAction>> Iterate(C45IterationParameters parameters);
 std::unique_ptr<dt::DecisionNode<ISimulatedGameAction>> PerformSplit(
 C45IterationParameters& params,
 int bestColumnIndex);
 
 const ISimulatedGameAction* globalFrequentAction = nullptr;
 std::unordered_set<int> usedColumns;
 int maxDepth = 0;
 int currentDepth = 0;
 };
}
}
}
 
#endif //GRAIL_C45_ALGORITHM_H