TimeAwareRatingPredictor Class Reference

Abstract class for time-aware rating predictors More...

Inheritance diagram for TimeAwareRatingPredictor:

Public Member Functions
virtual bool	CanPredict (int user_id, int item_id)
	Check whether a useful prediction (i.e. not using a fallback/default answer) can be made for a given user-item combination More...
Object	Clone ()
	create a shallow copy of the object More...
virtual void	LoadModel (string file)
	Get the model parameters from a file More...
abstract float	Predict (int user_id, int item_id)
	Predict rating or score for a given user-item combination More...
abstract float	Predict (int user_id, int item_id, DateTime time)
	predict rating at a certain point in time More...
IList< Tuple< int, float > >	Recommend (int user_id, int n=-1, ICollection< int > ignore_items=null, ICollection< int > candidate_items=null)
	Recommend items for a given user More...
virtual System.Collections.Generic.IList< Tuple< int, float > >	Recommend (int user_id, int n=-1, System.Collections.Generic.ICollection< int > ignore_items=null, System.Collections.Generic.ICollection< int > candidate_items=null)
virtual void	SaveModel (string file)
	Save the model parameters to a file More...
override string	ToString ()
	Return a string representation of the recommender More...
abstract void	Train ()
	Learn the model parameters of the recommender from the training data More...

Protected Attributes
float	max_rating
	Maximum rating value More...
float	min_rating
	Minimum rating value More...
IRatings	ratings
	rating data More...
ITimedRatings	timed_ratings
	rating data, including time information More...

Properties
int	MaxItemID [get, set]
	Maximum item ID More...
virtual float	MaxRating [get, set]
	Maximum rating value More...
int	MaxUserID [get, set]
	Maximum user ID More...
virtual float	MinRating [get, set]
	Minimum rating value More...
override IRatings	Ratings [get, set]
virtual ITimedRatings	TimedRatings [get, set]
	the rating data, including time information More...

Detailed Description

Abstract class for time-aware rating predictors

Exceptions

ArgumentException

Is thrown when an argument passed to a method is invalid.

Member Function Documentation

virtual bool CanPredict ( int  user_id, int  item_id  )

inlinevirtualinherited

Check whether a useful prediction (i.e. not using a fallback/default answer) can be made for a given user-item combination

It is up to the recommender implementor to decide when a prediction is useful, and to document it accordingly.

Parameters

user_id	the user ID
item_id	the item ID

Returns

true if a useful prediction can be made, false otherwise

Implements IRecommender.

Reimplemented in ExternalItemRecommender, ExternalRatingPredictor, BiPolarSlopeOne, SlopeOne, Constant, GlobalAverage, UserAverage, ItemAverage, and Random.

Object Clone ( )

inlineinherited

create a shallow copy of the object

virtual void LoadModel ( string  filename )

inlinevirtualinherited

Get the model parameters from a file

Parameters

filename

the name of the file to read from

Implements IRecommender.

Reimplemented in BPRMF, MatrixFactorization, BiasedMatrixFactorization, BPRSLIM, CoClustering, LeastSquareSLIM, SVDPlusPlus, UserItemBaseline, FactorWiseMatrixFactorization, SigmoidCombinedAsymmetricFactorModel, MF, SigmoidSVDPlusPlus, BiPolarSlopeOne, SigmoidItemAsymmetricFactorModel, SigmoidUserAsymmetricFactorModel, KNN, KNN, MostPopular, NaiveBayes, SlopeOne, SLIM, MostPopularByAttributes, EntityAverage, GlobalAverage, ExternalItemRecommender, ExternalRatingPredictor, Constant, Random, Random, and Zero.

abstract float Predict ( int  user_id, int  item_id  )

pure virtualinherited

Predict rating or score for a given user-item combination

Parameters

user_id	the user ID
item_id	the item ID

Returns

the predicted score/rating for the given user-item combination

Implements IRecommender.

Implemented in BPRMF, BiasedMatrixFactorization, LatentFeatureLogLinearModel, LeastSquareSLIM, MatrixFactorization, TimeAwareBaseline, FactorWiseMatrixFactorization, GSVDPlusPlus, MF, UserItemBaseline, CoClustering, NaiveBayes, SVDPlusPlus, SLIM, SigmoidCombinedAsymmetricFactorModel, MostPopularByAttributes, SigmoidSVDPlusPlus, SigmoidItemAsymmetricFactorModel, SigmoidUserAsymmetricFactorModel, MostPopular, BiPolarSlopeOne, ExternalItemRecommender, ExternalRatingPredictor, ItemKNN, ItemKNN, UserKNN, SlopeOne, Constant, UserKNN, GlobalAverage, UserAverage, ItemAverage, Random, Random, and Zero.

abstract float Predict ( int  user_id, int  item_id, DateTime  time  )

pure virtual

predict rating at a certain point in time

Parameters

user_id	the user ID
item_id	the item ID
time	the time of the rating event

Implements ITimeAwareRatingPredictor.

Implemented in TimeAwareBaseline, and TimeAwareBaselineWithFrequencies.

IList<Tuple<int, float> > Recommend ( int  user_id, int  n = -1, ICollection< int >  ignore_items = null, ICollection< int >  candidate_items = null  )

inherited

Recommend items for a given user

Parameters

user_id	the user ID
n	the number of items to recommend, -1 for as many as possible
ignore_items	collection if items that should not be returned; if null, use empty collection
candidate_items	the candidate items to choose from; if null, use all items

Returns

a sorted list of (item_id, score) tuples

Implemented in WeightedEnsemble, and Ensemble.

virtual void SaveModel ( string  filename )

inlinevirtualinherited

Save the model parameters to a file

Parameters

filename

the name of the file to write to

Implements IRecommender.

Reimplemented in BPRMF, MatrixFactorization, BiasedMatrixFactorization, BPRSLIM, CoClustering, LeastSquareSLIM, SVDPlusPlus, UserItemBaseline, FactorWiseMatrixFactorization, BiPolarSlopeOne, SigmoidCombinedAsymmetricFactorModel, MF, NaiveBayes, SigmoidItemAsymmetricFactorModel, SigmoidUserAsymmetricFactorModel, SlopeOne, KNN, MostPopular, KNN, SLIM, MostPopularByAttributes, EntityAverage, ExternalItemRecommender, ExternalRatingPredictor, GlobalAverage, Constant, Random, Random, and Zero.

override string ToString ( )

inlineinherited

Return a string representation of the recommender

The ToString() method of recommenders should list the class name and all hyperparameters, separated by space characters.

Implements IRecommender.

abstract void Train ( )

pure virtualinherited

Learn the model parameters of the recommender from the training data

Implements IRecommender.

Implemented in BiasedMatrixFactorization, TimeAwareBaseline, BPRMF, KNN, MatrixFactorization, KNN, LatentFeatureLogLinearModel, CoClustering, BiPolarSlopeOne, FactorWiseMatrixFactorization, BPRSLIM, SlopeOne, UserItemBaseline, LeastSquareSLIM, TimeAwareBaselineWithFrequencies, SVDPlusPlus, GSVDPlusPlus, SLIM, NaiveBayes, SigmoidCombinedAsymmetricFactorModel, MF, MostPopularByAttributes, SigmoidItemAsymmetricFactorModel, SigmoidUserAsymmetricFactorModel, SigmoidSVDPlusPlus, MostPopular, ExternalItemRecommender, ExternalRatingPredictor, MultiCoreBPRMF, WeightedBPRMF, Constant, ItemKNN, UserKNN, GlobalAverage, UserAverage, ItemAverage, Random, Random, and Zero.

Member Data Documentation

float max_rating

protectedinherited

Maximum rating value

float min_rating

protectedinherited

Minimum rating value

IRatings ratings

protectedinherited

rating data

ITimedRatings timed_ratings

protected

rating data, including time information

Property Documentation

int MaxItemID

getsetinherited

Maximum item ID

virtual float MaxRating

getsetinherited

Maximum rating value

int MaxUserID

getsetinherited

Maximum user ID

virtual float MinRating

getsetinherited

Minimum rating value

virtual ITimedRatings TimedRatings

getset

the rating data, including time information

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

• TimeAwareRatingPredictor.cs