This class implements the Normalized Discounted cumulative Gain NDCG@k measure. More...

#include <ndcg.h>

Inheritance diagram for quickrank::metric::ir::Ndcg:

Public Member Functions
	Ndcg (size_t k=NO_CUTOFF)

virtual	~Ndcg ()

virtual std::string	name () const
	Returns the name of the metric. More...

virtual MetricScore	evaluate_result_list (const quickrank::data::QueryResults rl, const Score scores) const

virtual std::unique_ptr< Jacobian >	jacobian (std::shared_ptr< data::RankedResults > ranked) const
	Computes the Jacobian matrix. More...

Public Member Functions inherited from quickrank::metric::ir::Dcg
	Dcg (size_t k=NO_CUTOFF)

virtual	~Dcg ()

Public Member Functions inherited from quickrank::metric::ir::Metric
	Metric (size_t k=NO_CUTOFF)
	Creates a new metric with the specified cut-off threshold. More...

virtual	~Metric ()

size_t	cutoff () const
	Returns the current cut-off of the Metric. More...

void	set_cutoff (size_t k)
	Updates the cut-off of the Metric. More...

virtual MetricScore	evaluate_dataset (const std::shared_ptr< data::Dataset > dataset, const Score *scores) const

virtual MetricScore	evaluate_dataset (const std::shared_ptr< data::VerticalDataset > dataset, const Score *scores) const

Static Public Attributes
static const std::string	NAME_ = "NDCG"

Static Public Attributes inherited from quickrank::metric::ir::Dcg
static const std::string	NAME_ = "DCG"

Static Public Attributes inherited from quickrank::metric::ir::Metric
static const size_t	NO_CUTOFF = SIZE_MAX
	This should be used when no cut-off on the results list is required. More...

Protected Member Functions
MetricScore	compute_idcg (const quickrank::data::QueryResults *rl) const
	Computes the IDCG@K of a given list of labels. More...

Protected Member Functions inherited from quickrank::metric::ir::Dcg
MetricScore	compute_dcg (const Label *labels, size_t len) const
	Computes the DCG@K of a given array of labels. More...

Private Member Functions
virtual std::ostream &	put (std::ostream &os) const
	Prints the short name of the Metric, e.g., "NDCG@K". More...

Friends
std::ostream &	operator<< (std::ostream &os, const Ndcg &ndcg)

Detailed Description

This class implements the Normalized Discounted cumulative Gain NDCG@k measure.

NDCG is measured as: \( NDCG_k = \frac{1}{IDCG_k}\sum_{i=1}^k \frac{2^{l_i}-1}{\log_2 (i+1)}\), where \(l_i\) is the relevance label of the i-th document, and \(IDCG_k\) is the NDCG@K of a perfectly orderd result list.