es.upm.etsisi.cf4j.qualityMeasure.prediction

Class R2

java.lang.Object

es.upm.etsisi.cf4j.qualityMeasure.QualityMeasure

es.upm.etsisi.cf4j.qualityMeasure.prediction.R2

public class R2
extends QualityMeasure

This class calculates the the coefficient of determination, usually denoted as R2, of the predictions performed by a recommender.

MSE = (∑(<test item rating> - <test item rating prediction>)² + (<test item rating> - <getTestRatingAverage>)²) / <number of predictions>

Field Summary

Fields inherited from class es.upm.etsisi.cf4j.qualityMeasure.QualityMeasure

recommender

Constructor Summary

Constructors

Constructor and Description
R2(Recommender recommender) Constructor of the class which basically calls the father's one

Method Summary

Modifier and Type	Method and Description
double	getScore(TestUser testUser, double[] predictions) Computes the quality measure score for a TestUser given the predictions for his/her test ratings

Methods inherited from class es.upm.etsisi.cf4j.qualityMeasure.QualityMeasure

getScore, getScore

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

R2

public R2(Recommender recommender)

Constructor of the class which basically calls the father's one

Parameters:

recommender - Recommender instance for which the R2 are going to be computed

Method Detail

getScore

public double getScore(TestUser testUser,
                       double[] predictions)

Description copied from class: QualityMeasure

Computes the quality measure score for a TestUser given the predictions for his/her test ratings

Specified by:

getScore in class QualityMeasure

Parameters:

testUser - TestUser for which the quality measure score is computed

predictions - Prediction value for the test items rated by the test user

Returns:

Quality measure score