RandomizedSVDPolicy Class Reference

Implementation of the Randomized SVD policy to act as a wrapper when accessing Randomized SVD from within CFType. More...

#include <randomized_svd_method.hpp>

Public Member Functions
	RandomizedSVDPolicy (const size_t iteratedPower=0, const size_t maxIterations=2)
	Use randomized SVD method to perform collaborative filtering. More...
template<typename MatType >
void	Apply (const MatType &, const arma::sp_mat &cleanedData, const size_t rank, const size_t maxIterations, const double, const bool)
	Apply Collaborative Filtering to the provided data set using the randomized SVD. More...
template<typename NeighborSearchPolicy >
void	GetNeighborhood (const arma::Col< size_t > &users, const size_t numUsersForSimilarity, arma::Mat< size_t > &neighborhood, arma::mat &similarities) const
	Get the neighborhood and corresponding similarities for a set of users. More...
double	GetRating (const size_t user, const size_t item) const
	Return predicted rating given user ID and item ID. More...
void	GetRatingOfUser (const size_t user, arma::vec &rating) const
	Get predicted ratings for a user. More...
const arma::mat &	H () const
	Get the User Matrix. More...
size_t &	IteratedPower ()
	Modify the size of the normalized power iterations. More...
size_t	IteratedPower () const
	Get the size of the normalized power iterations. More...
size_t &	MaxIterations ()
	Modify the number of iterations. More...
size_t	MaxIterations () const
	Get the number of iterations. More...
template<typename Archive >
void	serialize (Archive &ar, const unsigned int)
	Serialization. More...
const arma::mat &	W () const
	Get the Item Matrix. More...

Detailed Description

Implementation of the Randomized SVD policy to act as a wrapper when accessing Randomized SVD from within CFType.

An example of how to use RandomizedSVDPolicy 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<RandomizedSVDPolicy> cf(data);
 
// Generate 10 recommendations for all users.
cf.GetRecommendations(10, recommendations);

Definition at line 41 of file randomized_svd_method.hpp.

Constructor & Destructor Documentation

RandomizedSVDPolicy()

RandomizedSVDPolicy ( const size_t  iteratedPower = 0, const size_t  maxIterations = 2  )

inline

Use randomized SVD method to perform collaborative filtering.

Parameters

iteratedPower	Size of the normalized power iterations (Default: rank + 2).
maxIterations	Number of iterations for the power method (Default: 2).

Definition at line 52 of file randomized_svd_method.hpp.

Member Function Documentation

Apply()

void Apply ( const MatType &  , const arma::sp_mat &  cleanedData, const size_t  rank, const size_t  maxIterations, const double  , const bool    )

inline

Apply Collaborative Filtering to the provided data set using the randomized SVD.

Parameters

*	(data) Data matrix: dense matrix (coordinate lists) or sparse matrix(cleaned).
cleanedData	item user table in form of sparse matrix.
rank	Rank parameter for matrix factorization.
maxIterations	Maximum number of iterations.
*	(minResidue) Residue required to terminate.
*	(mit) Whether to terminate only when maxIterations is reached.

Definition at line 73 of file randomized_svd_method.hpp.

References RandomizedSVD::Apply().

GetNeighborhood()

void GetNeighborhood ( const arma::Col< size_t > &  users, const size_t  numUsersForSimilarity, arma::Mat< size_t > &  neighborhood, arma::mat &  similarities  ) const

inline

Get the neighborhood and corresponding similarities for a set of users.

Template Parameters

NeighborSearchPolicy

The policy to perform neighbor search.

Parameters

users	Users whose neighborhood is to be computed.
numUsersForSimilarity	The number of neighbors returned for each user.
neighborhood	Neighbors represented by user IDs.
similarities	Similarity between each user and each of its neighbors.

Definition at line 129 of file randomized_svd_method.hpp.

GetRating()

double GetRating ( const size_t  user, const size_t  item  ) const

inline

Return predicted rating given user ID and item ID.

Parameters

user	User ID.
item	Item ID.

Definition at line 99 of file randomized_svd_method.hpp.

GetRatingOfUser()

void GetRatingOfUser ( const size_t  user, arma::vec &  rating  ) const

inline

Get predicted ratings for a user.

Parameters

user	User ID.
rating	Resulting rating vector.

Definition at line 111 of file randomized_svd_method.hpp.

H()

const arma::mat & H ( ) const

inline

Get the User Matrix.

Definition at line 158 of file randomized_svd_method.hpp.

IteratedPower() [1/2]

size_t & IteratedPower ( )

inline

Modify the size of the normalized power iterations.

Definition at line 163 of file randomized_svd_method.hpp.

IteratedPower() [2/2]

size_t IteratedPower ( ) const

inline

Get the size of the normalized power iterations.

Definition at line 161 of file randomized_svd_method.hpp.

MaxIterations() [1/2]

size_t & MaxIterations ( )

inline

Modify the number of iterations.

Definition at line 168 of file randomized_svd_method.hpp.

MaxIterations() [2/2]

size_t MaxIterations ( ) const

inline

Get the number of iterations.

Definition at line 166 of file randomized_svd_method.hpp.

serialize()

void serialize ( Archive &  ar, const unsigned int    )

inline

Serialization.

Definition at line 174 of file randomized_svd_method.hpp.

W()

const arma::mat & W ( ) const

inline

Get the Item Matrix.

Definition at line 156 of file randomized_svd_method.hpp.

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

• src/mlpack/methods/cf/decomposition_policies/randomized_svd_method.hpp