RandomizedSVDPolicy Class Reference

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

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 () const
 Get the size of the normalized power iterations. More...

 
size_t & IteratedPower ()
 Modify the size of the normalized power iterations. More...

 
size_t MaxIterations () const
 Get the number of iterations. More...

 
size_t & MaxIterations ()
 Modify the number of iterations. More...

 
template
<
typename
Archive
>
void serialize (Archive &ar, const uint32_t)
 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
iteratedPowerSize of the normalized power iterations (Default: rank + 2).
maxIterationsNumber 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).
cleanedDataitem user table in form of sparse matrix.
rankRank parameter for matrix factorization.
maxIterationsMaximum 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
NeighborSearchPolicyThe policy to perform neighbor search.
Parameters
usersUsers whose neighborhood is to be computed.
numUsersForSimilarityThe number of neighbors returned for each user.
neighborhoodNeighbors represented by user IDs.
similaritiesSimilarity 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
userUser ID.
itemItem 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
userUser ID.
ratingResulting 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 ( ) const
inline

Get the size of the normalized power iterations.

Definition at line 161 of file randomized_svd_method.hpp.

◆ IteratedPower() [2/2]

size_t& IteratedPower ( )
inline

Modify the size of the normalized power iterations.

Definition at line 163 of file randomized_svd_method.hpp.

◆ MaxIterations() [1/2]

size_t MaxIterations ( ) const
inline

Get the number of iterations.

Definition at line 166 of file randomized_svd_method.hpp.

◆ MaxIterations() [2/2]

size_t& MaxIterations ( )
inline

Modify the number of iterations.

Definition at line 168 of file randomized_svd_method.hpp.

◆ serialize()

void serialize ( Archive &  ar,
const uint32_t   
)
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.


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