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use ndcg@all in lambdarank for ndcg

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This commit is contained in:
yepyao 2014-05-16 23:06:24 +08:00
parent 5db373e73c
commit 4d03729683
1 changed files with 10 additions and 3 deletions
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13
regrank/xgboost_regrank_obj.hpp
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@ -336,8 +336,15 @@ namespace xgboost{
public: public:
virtual ~LambdaRankObj_NDCG(void){} virtual ~LambdaRankObj_NDCG(void){}
inline float DCG(const std::vector<float> &labels){ inline float CalcDCG( const std::vector<float> &labels ){
return 1.0; double sumdcg = 0.0;
for( size_t i = 0; i < labels.size(); i ++ ){
const unsigned rel = labels[i];
if( rel != 0 ){
sumdcg += logf(2.0f) * ((1<<rel)-1) / logf( i + 2 );
}
}
return static_cast<float>(sumdcg);
} }
inline float GetIDCG(const std::vector<ListEntry> &sorted_list){ inline float GetIDCG(const std::vector<ListEntry> &sorted_list){
@ -347,7 +354,7 @@ namespace xgboost{
} }
std::sort(labels.begin(), labels.end(), std::greater<float>()); std::sort(labels.begin(), labels.end(), std::greater<float>());
return DCG(labels); return CalcDCG(labels);
} }
/* /*