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start add coltree maker

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This commit is contained in:
tqchen
2014-02-28 11:44:50 -08:00
parent 82807b3a55
commit b57656902e
5 changed files with 217 additions and 35 deletions
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24
booster/tree/xgboost_tree_model.h
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@@ -391,7 +391,7 @@ namespace xgboost{
}
public:
// calculate the cost of loss function
inline double CalcCost( double sum_grad, double sum_hess ) const{
inline double CalcGain( double sum_grad, double sum_hess ) const{
if( sum_hess < min_child_weight ){
return 0.0;
}
@@ -405,29 +405,37 @@ namespace xgboost{
}
// KEY:layerwise
// calculate cost of root
inline double CalcRootCost( double sum_grad, double sum_hess ) const{
if( use_layerwise == 0 ) return this->CalcCost( sum_grad, sum_hess );
inline double CalcRootGain( double sum_grad, double sum_hess ) const{
if( use_layerwise == 0 ) return this->CalcGain( sum_grad, sum_hess );
else return 0.0;
}
// KEY:layerwise
// calculate the cost after split
// base_weight: the base_weight of parent
inline double CalcCost( double sum_grad, double sum_hess, double base_weight ) const{
if( use_layerwise == 0 ) return this->CalcCost( sum_grad, sum_hess );
else return this->CalcCost( sum_grad + sum_hess * base_weight, sum_hess );
inline double CalcGain( double sum_grad, double sum_hess, double base_weight ) const{
if( use_layerwise == 0 ) return this->CalcGain( sum_grad, sum_hess );
else return this->CalcGain( sum_grad + sum_hess * base_weight, sum_hess );
}
// calculate the weight of leaf
inline double CalcWeight( double sum_grad, double sum_hess, double parent_base_weight )const{
if( use_layerwise == 0 ) return CalcWeight( sum_grad, sum_hess );
else return parent_base_weight + CalcWeight( sum_grad + parent_base_weight * sum_hess, sum_hess );
}
/*! \brief whether need forward small to big search: default right */
inline bool need_forward_search( void ) const{
return this->default_direction != 1;
}
/*! \brief whether need forward big to small search: default left */
inline bool need_backward_search( void ) const{
return this->default_direction != 2;
}
/*! \brief given the loss change, whether we need to invode prunning */
inline bool need_prune( double loss_chg, int depth ) const{
return loss_chg < min_split_loss;
return loss_chg < this->min_split_loss;
}
/*! \brief whether we can split with current hessian */
inline bool cannot_split( double sum_hess, int depth ) const{
return sum_hess < min_child_weight * 2.0;
return sum_hess < this->min_child_weight * 2.0;
}
};
};