NAME¶

mlpack::cf::CF< FactorizerType > - This class implements Collaborative Filtering ( CF).

SYNOPSIS¶

Public Member Functions¶

CF (arma::mat &data, const size_t numUsersForSimilarity=5, const size_t rank=0) Initialize the CF object. const arma::sp_mat & CleanedData () const Get the cleaned data matrix. const arma::mat & Data () const Get the data matrix. void Factorizer (const FactorizerType &f) Sets factorizer for NMF. void GetRecommendations (const size_t numRecs, arma::Mat< size_t > &recommendations) Generates the given number of recommendations for all users. void GetRecommendations (const size_t numRecs, arma::Mat< size_t > &recommendations, arma::Col< size_t > &users) Generates the given number of recommendations for the specified users. const arma::mat & H () const Get the Item Matrix. void NumUsersForSimilarity (const size_t num) Sets number of users for calculating similarity. size_t NumUsersForSimilarity () const Gets number of users for calculating similarity. void Rank (const size_t rankValue) Sets rank parameter for matrix factorization. size_t Rank () const Gets rank parameter for matrix factorization. const arma::mat & Rating () const Get the Rating Matrix. std::string ToString () const Returns a string representation of this object. const arma::mat & W () const Get the User Matrix.

Private Member Functions¶

void CleanData () Converts the User, Item, Value Matrix to User-Item Table. void InsertNeighbor (const size_t queryIndex, const size_t pos, const size_t neighbor, const double value, arma::Mat< size_t > &recommendations, arma::mat &values) const Helper function to insert a point into the recommendation matrices.

Private Attributes¶

arma::sp_mat cleanedData Cleaned data matrix. arma::mat data Initial data matrix. FactorizerType factorizer Instantiated factorizer object. arma::mat h Item matrix. size_t numUsersForSimilarity Number of users for similarity. size_t rank Rank used for matrix factorization. arma::mat rating Rating matrix. arma::mat w User matrix.

Detailed Description¶

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>>class mlpack::cf::CF< FactorizerType >¶

This class implements Collaborative Filtering ( CF). This implementation presently supports Alternating Least Squares (ALS) for collaborative filtering. A simple example of how to run Collaborative Filtering is shown below.

extern arma::mat data; // (user, item, rating) table
extern arma::Col<size_t> users; // users seeking recommendations
arma::Mat<size_t> recommendations; // Recommendations

CF<> cf(data); // Default options.

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

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

The data matrix is a (user, item, rating) table. Each column in the matrix should have three rows. The first represents the user; the second represents the item; and the third represents the rating. The user and item, while they are in a matrix that holds doubles, should hold integer (or size_t) values. The user and item indices are assumed to start at 0. Template Parameters: Definition at line 76 of file cf.hpp.

Constructor & Destructor Documentation¶

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> mlpack::cf::CF< FactorizerType >:: CF (arma::mat &data, const size_tnumUsersForSimilarity = 5, const size_trank = 0)¶

Initialize the CF object. Store a reference to the data that we will be using. There are parameters that can be set; default values are provided for each of them. If the rank is left unset (or is set to 0), a simple density-based heuristic will be used to choose a rank. Parameters:

Member Function Documentation¶

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::CleanData () [private]¶

Converts the User, Item, Value Matrix to User-Item Table.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> const arma::sp_mat& mlpack::cf::CF< FactorizerType >::CleanedData () const [inline]¶

Get the cleaned data matrix. Definition at line 138 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::cleanedData.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> const arma::mat& mlpack::cf::CF< FactorizerType >::Data () const [inline]¶

Get the data matrix. Definition at line 136 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::data.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::Factorizer (const FactorizerType &f) [inline]¶

Sets factorizer for NMF. Definition at line 124 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::factorizer.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::GetRecommendations (const size_tnumRecs, arma::Mat< size_t > &recommendations)¶

Generates the given number of recommendations for all users. Parameters:

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::GetRecommendations (const size_tnumRecs, arma::Mat< size_t > &recommendations, arma::Col< size_t > &users)¶

Generates the given number of recommendations for the specified users. Parameters:

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> const arma::mat& mlpack::cf::CF< FactorizerType >::H () const [inline]¶

Get the Item Matrix. Definition at line 132 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::h.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::InsertNeighbor (const size_tqueryIndex, const size_tpos, const size_tneighbor, const doublevalue, arma::Mat< size_t > &recommendations, arma::mat &values) const [private]¶

Helper function to insert a point into the recommendation matrices. Parameters:

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::NumUsersForSimilarity (const size_tnum) [inline]¶

Sets number of users for calculating similarity. Definition at line 94 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::numUsersForSimilarity, and mlpack::Log::Warn.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> size_t mlpack::cf::CF< FactorizerType >::NumUsersForSimilarity () const [inline]¶

Gets number of users for calculating similarity. Definition at line 106 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::numUsersForSimilarity.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> void mlpack::cf::CF< FactorizerType >::Rank (const size_trankValue) [inline]¶

Sets rank parameter for matrix factorization. Definition at line 112 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::rank.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> size_t mlpack::cf::CF< FactorizerType >::Rank () const [inline]¶

Gets rank parameter for matrix factorization. Definition at line 118 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::rank.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> const arma::mat& mlpack::cf::CF< FactorizerType >::Rating () const [inline]¶

Get the Rating Matrix. Definition at line 134 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::rating.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> std::string mlpack::cf::CF< FactorizerType >::ToString () const¶

Returns a string representation of this object.

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> const arma::mat& mlpack::cf::CF< FactorizerType >::W () const [inline]¶

Get the User Matrix. Definition at line 130 of file cf.hpp. References mlpack::cf::CF< FactorizerType >::w.

Member Data Documentation¶

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> arma::sp_mat mlpack::cf::CF< FactorizerType >::cleanedData [private]¶

Cleaned data matrix. Definition at line 181 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::CleanedData().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> arma::mat mlpack::cf::CF< FactorizerType >::data [private]¶

Initial data matrix. Definition at line 167 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::Data().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> FactorizerType mlpack::cf::CF< FactorizerType >::factorizer [private]¶

Instantiated factorizer object. Definition at line 173 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::Factorizer().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> arma::mat mlpack::cf::CF< FactorizerType >::h [private]¶

Item matrix. Definition at line 177 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::H().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> size_t mlpack::cf::CF< FactorizerType >::numUsersForSimilarity [private]¶

Number of users for similarity. Definition at line 169 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::NumUsersForSimilarity().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> size_t mlpack::cf::CF< FactorizerType >::rank [private]¶

Rank used for matrix factorization. Definition at line 171 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::Rank().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> arma::mat mlpack::cf::CF< FactorizerType >::rating [private]¶

Rating matrix. Definition at line 179 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::Rating().

template<typename FactorizerType = amf::AMF<amf::SimpleResidueTermination, amf::RandomInitialization, amf::NMFALSUpdate>> arma::mat mlpack::cf::CF< FactorizerType >::w [private]¶

User matrix. Definition at line 175 of file cf.hpp. Referenced by mlpack::cf::CF< FactorizerType >::W().

Author¶

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