QualityMeasure (CF4J 2.3.0 API Documentation)

java.lang.Object
- es.upm.etsisi.cf4j.qualityMeasure.QualityMeasure

Direct Known Subclasses:

Coverage, Discovery, Diversity, F1, MAE, Max, MSE, MSLE, NDCG, Novelty, Perfect, Precision, R2, Recall
```
public abstract class QualityMeasure
extends Object
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Abstract class used to simplify the evaluation of collaborative filtering based recommendation models. To define a new quality measure, getScore(TestUser testUser, double[] predictions) must be encoded.

Field Summary

Fields
Modifier and Type Field Description

protected Recommender recommender
Recommender instance for which the quality measure are going to be computed

Constructor Summary

Constructors
Constructor Description

QualityMeasure(Recommender recommender)
Creates a new quality measure

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`double`	`getScore()`	Computes the quality measure of the recommender
`double`	`getScore(int numThreads)`	Computes the quality measure of the recommender
`protected abstract 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 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - recommender
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protected Recommender recommender
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    Recommender instance for which the quality measure are going to be computed
- Constructor Detail
  - QualityMeasure
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public QualityMeasure(Recommender recommender)
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    Creates a new quality measure
    
    Parameters:
    
    recommender - Recommender instance for which the quality measure are going to be computed
- Method Detail
  - getScore
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protected abstract double getScore(TestUser testUser,
                                   double[] predictions)
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    Computes the quality measure score for a TestUser given the predictions for his/her test ratings
    
    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
  - getScore
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public double getScore(int numThreads)
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    Computes the quality measure of the recommender
    
    Parameters:
    
    numThreads - Number of threads to compute de quality measure in parallel for each test user. Use all available threads by default.
    
    Returns:
    
    Quality measure score
  - getScore
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public double getScore()
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    Computes the quality measure of the recommender
    
    Returns:
    
    Quality measure score