Objective function for Lambdrank with NDCG. More...

#include <rank_objective.hpp>

Inheritance diagram for LightGBM::LambdarankNDCG:

Public Member Functions
	LambdarankNDCG (const Config &config)

	LambdarankNDCG (const std::vector< std::string > &)

void	Init (const Metadata &metadata, data_size_t num_data) override
	Initialize.

void	GetGradients (const double score, score_t gradients, score_t *hessians) const override
	calculating first order derivative of loss function

void	GetGradientsForOneQuery (const double score, score_t lambdas, score_t *hessians, data_size_t query_id) const

double	GetSigmoid (double score) const

void	ConstructSigmoidTable ()

const char *	GetName () const override

std::string	ToString () const override

bool	NeedAccuratePrediction () const override
	The prediction should be accurate or not. True will disable early stopping for prediction.

Public Member Functions inherited from LightGBM::ObjectiveFunction
virtual	~ObjectiveFunction ()
	virtual destructor

virtual bool	IsConstantHessian () const

virtual bool	IsRenewTreeOutput () const

virtual double	RenewTreeOutput (double ori_output, const double , const data_size_t , const data_size_t *, data_size_t) const

virtual double	RenewTreeOutput (double ori_output, double, const data_size_t , const data_size_t , data_size_t) const

virtual double	BoostFromScore (int) const

virtual bool	ClassNeedTrain (int) const

virtual bool	SkipEmptyClass () const

virtual int	NumModelPerIteration () const

virtual int	NumPredictOneRow () const

virtual void	ConvertOutput (const double input, double output) const

ObjectiveFunction &	operator= (const ObjectiveFunction &)=delete
	Disable copy.

	ObjectiveFunction (const ObjectiveFunction &)=delete
	Disable copy.

Additional Inherited Members
Static Public Member Functions inherited from LightGBM::ObjectiveFunction
static LIGHTGBM_EXPORT ObjectiveFunction *	CreateObjectiveFunction (const std::string &type, const Config &config)
	Create object of objective function.

static LIGHTGBM_EXPORT ObjectiveFunction *	CreateObjectiveFunction (const std::string &str)
	Load objective function from string object.

Detailed Description

Objective function for Lambdrank with NDCG.

Member Function Documentation

◆ GetGradients()

void LightGBM::LambdarankNDCG::GetGradients	(	const double *	score,
		score_t *	gradients,
		score_t *	hessians
	)		const

inlineoverridevirtual

calculating first order derivative of loss function

Parameters

score prediction score in this round \gradients Output gradients \hessians Output hessians

Implements LightGBM::ObjectiveFunction.

◆ GetName()

const char * LightGBM::LambdarankNDCG::GetName ( ) const

inlineoverridevirtual

Implements LightGBM::ObjectiveFunction.

◆ Init()

void LightGBM::LambdarankNDCG::Init	(	const Metadata &	metadata,
		data_size_t	num_data
	)

inlineoverridevirtual

Initialize.

Parameters

metadata	Label data
num_data	Number of data

Implements LightGBM::ObjectiveFunction.

◆ NeedAccuratePrediction()

bool LightGBM::LambdarankNDCG::NeedAccuratePrediction ( ) const

inlineoverridevirtual

The prediction should be accurate or not. True will disable early stopping for prediction.

Reimplemented from LightGBM::ObjectiveFunction.

◆ ToString()

std::string LightGBM::LambdarankNDCG::ToString ( ) const

inlineoverridevirtual

Implements LightGBM::ObjectiveFunction.

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

External/LightGBM_2.2.3/LightGBM-2.2.3/src/objective/rank_objective.hpp

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ GetGradients()

◆ GetName()

◆ Init()

◆ NeedAccuratePrediction()

◆ ToString()