mlpack::cf::CombinedNormalization< NormalizationTypes > Class Template Reference

This normalization class performs a sequence of normalization methods on raw ratings. More...

#include <combined_normalization.hpp>

Public Types
using	TupleType = std::tuple< NormalizationTypes... >

Public Member Functions
template<typename MatType >
void	Normalize (MatType &data)
	Normalize the data by calling Normalize() in each normalization object. More...
double	Denormalize (const size_t user, const size_t item, const double rating) const
	Denormalize rating by calling Denormalize() in each normalization object. More...
void	Denormalize (const arma::Mat< size_t > &combinations, arma::vec &predictions) const
	Denormalize rating by calling Denormalize() in each normalization object. More...
const TupleType &	Normalizations () const
	Return normalizations tuple.
template<typename Archive >
void	serialize (Archive &ar, const uint32_t version)
	Serialization.

Detailed Description

template<typename... NormalizationTypes>
class mlpack::cf::CombinedNormalization< NormalizationTypes >

This normalization class performs a sequence of normalization methods on raw ratings.

An example of how to use CombinedNormalization 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.

CFType<NMFPolicy,
       CombinedNormalization<
           OverallMeanNormalization,
           UserMeanNormalization,
           ItemMeanNormalization>> cf(data);

// Generate 10 recommendations for all users.
cf.GetRecommendations(10, recommendations);

Member Function Documentation

Denormalize() [1/2]

template<typename... NormalizationTypes>

double mlpack::cf::CombinedNormalization< NormalizationTypes >::Denormalize ( const size_t  user, const size_t  item, const double  rating  ) const

inline

Denormalize rating by calling Denormalize() in each normalization object.

Note that the order of objects calling Denormalize() should be the reversed order of objects calling Normalize().

Parameters

user	User ID.
item	Item ID.
rating	Computed rating before denormalization.

Denormalize() [2/2]

template<typename... NormalizationTypes>

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

inline

Denormalize rating by calling Denormalize() in each normalization object.

Note that the order of objects calling Denormalize() should be the reversed order of objects calling Normalize().

Parameters

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

Normalize()

template<typename... NormalizationTypes>

template<typename MatType >

void mlpack::cf::CombinedNormalization< NormalizationTypes >::Normalize ( MatType &  data )

inline

Normalize the data by calling Normalize() in each normalization object.

Parameters

data	Input dataset.

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

• src/mlpack/methods/cf/normalization/combined_normalization.hpp