LightGBM::DCGCalculator Class Reference

Static class, used to calculate DCG score. More...

#include <metric.h>

Static Public Member Functions
static void	DefaultEvalAt (std::vector< int > *eval_at)
static void	DefaultLabelGain (std::vector< double > *label_gain)
static void	Init (const std::vector< double > &label_gain)
	Initial logic.
static double	CalDCGAtK (data_size_t k, const label_t *label, const double *score, data_size_t num_data)
	Calculate the DCG score at position k.
static void	CalDCG (const std::vector< data_size_t > &ks, const label_t *label, const double *score, data_size_t num_data, std::vector< double > *out)
	Calculate the DCG score at multi position.
static double	CalMaxDCGAtK (data_size_t k, const label_t *label, data_size_t num_data)
	Calculate the Max DCG score at position k.
static void	CheckLabel (const label_t *label, data_size_t num_data)
	Check the label range for NDCG and lambdarank.
static void	CalMaxDCG (const std::vector< data_size_t > &ks, const label_t *label, data_size_t num_data, std::vector< double > *out)
	Calculate the Max DCG score at multi position.
static double	GetDiscount (data_size_t k)
	Get discount score of position k.

Detailed Description

Static class, used to calculate DCG score.

Member Function Documentation

CalDCG()

void LightGBM::DCGCalculator::CalDCG ( const std::vector< data_size_t > &  ks, const label_t *  label, const double *  score, data_size_t  num_data, std::vector< double > *  out  )

static

Calculate the DCG score at multi position.

Parameters

ks	The positions to evaluate
label	Pointer of label
score	Pointer of score
num_data	Number of data
out	Output result

CalDCGAtK()

double LightGBM::DCGCalculator::CalDCGAtK ( data_size_t  k, const label_t *  label, const double *  score, data_size_t  num_data  )

static

Calculate the DCG score at position k.

Parameters

k	The position to evaluate
label	Pointer of label
score	Pointer of score
num_data	Number of data

Returns

The DCG score

CalMaxDCG()

void LightGBM::DCGCalculator::CalMaxDCG ( const std::vector< data_size_t > &  ks, const label_t *  label, data_size_t  num_data, std::vector< double > *  out  )

static

Calculate the Max DCG score at multi position.

Parameters

ks	The positions want to eval at
label	Pointer of label
num_data	Number of data
out	Output result

CalMaxDCGAtK()

double LightGBM::DCGCalculator::CalMaxDCGAtK ( data_size_t  k, const label_t *  label, data_size_t  num_data  )

static

Calculate the Max DCG score at position k.

Parameters

k	The position want to eval at
label	Pointer of label
num_data	Number of data

Returns

The max DCG score

CheckLabel()

void LightGBM::DCGCalculator::CheckLabel ( const label_t *  label, data_size_t  num_data  )

static

Check the label range for NDCG and lambdarank.

Parameters

label	Pointer of label
num_data	Number of data

GetDiscount()

static double LightGBM::DCGCalculator::GetDiscount ( data_size_t  k )

inlinestatic

Get discount score of position k.

Parameters

k	The position

Returns

The discount of this position

Init()

void LightGBM::DCGCalculator::Init ( const std::vector< double > &  label_gain )

static

Initial logic.

Parameters

label_gain

Gain for labels, default is 2^i - 1

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The documentation for this class was generated from the following files:

• External/LightGBM_2.2.3/LightGBM-2.2.3/include/LightGBM/metric.h
• External/LightGBM_2.2.3/LightGBM-2.2.3/src/metric/dcg_calculator.cpp