CombinedNormalization< NormalizationTypes > Class Template Reference

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

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

Public Member Functions
	CombinedNormalization ()
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. More...
template < typename MatType >
void	Normalize (MatType &data)
	Normalize the data by calling Normalize() in each normalization object. More...
template < typename Archive >
void	serialize (Archive &ar, const uint32_t version)
	Serialization. More...

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);

Definition at line 44 of file combined_normalization.hpp.

Member Typedef Documentation

TupleType

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

Definition at line 47 of file combined_normalization.hpp.

Constructor & Destructor Documentation

CombinedNormalization()

CombinedNormalization ( )

inline

Definition at line 50 of file combined_normalization.hpp.

Member Function Documentation

Denormalize() [1/2]

double 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.

Definition at line 72 of file combined_normalization.hpp.

Referenced by CombinedNormalization< NormalizationTypes >::serialize().

Denormalize() [2/2]

void 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.

Definition at line 87 of file combined_normalization.hpp.

Normalizations()

const TupleType& Normalizations ( ) const

inline

Return normalizations tuple.

Definition at line 96 of file combined_normalization.hpp.

Normalize()

void Normalize ( MatType &  data )

inline

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

Parameters

data	Input dataset.

Definition at line 58 of file combined_normalization.hpp.

Referenced by CombinedNormalization< NormalizationTypes >::serialize().

serialize()

void serialize ( Archive &  ar, const uint32_t  version  )

inline

Serialization.

Definition at line 105 of file combined_normalization.hpp.

References CombinedNormalization< NormalizationTypes >::Denormalize(), and CombinedNormalization< NormalizationTypes >::Normalize().

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

• /home/ryan/src/mlpack.org/_src/mlpack-git/src/mlpack/methods/cf/normalization/combined_normalization.hpp