mlpack: ItemMeanNormalization Class Reference

mlpack 3.4.2

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This normalization class performs item mean normalization on raw ratings. More...

#include <item_mean_normalization.hpp>

Public Member Functions
	ItemMeanNormalization ()

void	Denormalize (const arma::Mat< size_t > &combinations, arma::vec &predictions) const
	Denormalize computed rating by adding item mean. More...

double	Denormalize (const size_t, const size_t item, const double rating) const
	Denormalize computed rating by adding item mean. More...

const arma::vec &	Mean () const
	Return item mean. More...

void	Normalize (arma::mat &data)
	Normalize the data by subtracting item mean from each of existing ratings. More...

void	Normalize (arma::sp_mat &cleanedData)
	Normalize the data by subtracting item mean from each of existing ratings. More...

template<typename Archive >
void	serialize (Archive &ar, const unsigned int)
	Serialization. More...

Detailed Description

This normalization class performs item mean normalization on raw ratings.

An example of how to use ItemMeanNormalization in CF is shown below:

extern arma::mat data; // data is a (user, item, rating) table.
// Users for whom recommendations are generated.
extern arma::Col<size_t> users;
arma::Mat<size_t> recommendations; // Resulting recommendations.
 
// Use ItemMeanNormalization as normalization method.
CFType<NMFPolicy, ItemMeanNormalization> cf(data);
 
// Generate 10 recommendations for all users.
cf.GetRecommendations(10, recommendations);

Definition at line 39 of file item_mean_normalization.hpp.

Constructor & Destructor Documentation

◆ ItemMeanNormalization()

ItemMeanNormalization ( )

inline

Definition at line 43 of file item_mean_normalization.hpp.

Member Function Documentation

◆ Denormalize() [1/2]

void Denormalize	(	const arma::Mat< size_t > &	combinations,
		arma::vec &	predictions
	)		const

inline

Denormalize computed rating by adding item mean.

Parameters

combinations	User/Item combinations.
predictions	Predicted ratings for each user/item combination.

Definition at line 143 of file item_mean_normalization.hpp.

◆ Denormalize() [2/2]

double Denormalize	(	const	size_t,
		const size_t	item,
		const double	rating
	)		const

inline

Denormalize computed rating by adding item mean.

Parameters

*	(user) User ID.
item	Item ID.
rating	Computed rating before denormalization.

Definition at line 130 of file item_mean_normalization.hpp.

◆ Mean()

const arma::vec & Mean ( ) const

inline

Return item mean.

Definition at line 156 of file item_mean_normalization.hpp.

◆ Normalize() [1/2]

void Normalize ( arma::mat & data )

inline

Normalize the data by subtracting item mean from each of existing ratings.

Parameters

data	Input dataset in the form of coordinate list.

Definition at line 50 of file item_mean_normalization.hpp.

◆ Normalize() [2/2]

void Normalize ( arma::sp_mat & cleanedData )

inline

Normalize the data by subtracting item mean from each of existing ratings.

Parameters

cleanedData Input data as a sparse matrix.

Definition at line 90 of file item_mean_normalization.hpp.

◆ serialize()

void serialize	(	Archive &	ar,
		const unsigned int
	)

inline

Serialization.

Definition at line 162 of file item_mean_normalization.hpp.

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

src/mlpack/methods/cf/normalization/item_mean_normalization.hpp