org.apache.mahout.cf.taste.similarity.precompute

Class BatchItemSimilarities

java.lang.Object

org.apache.mahout.cf.taste.similarity.precompute.BatchItemSimilarities

Direct Known Subclasses:

MultithreadedBatchItemSimilarities

public abstract class BatchItemSimilarities
extends Object

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BatchItemSimilarities(ItemBasedRecommender recommender, int similarItemsPerItem)

Method Summary

Modifier and Type	Method and Description
abstract int	computeItemSimilarities(int degreeOfParallelism, int maxDurationInHours, SimilarItemsWriter writer)
protected ItemBasedRecommender	getRecommender()
protected int	getSimilarItemsPerItem()

Methods inherited from class java.lang.Object

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

Constructor Detail

BatchItemSimilarities

protected BatchItemSimilarities(ItemBasedRecommender recommender,
                                int similarItemsPerItem)

Parameters:

recommender - recommender to use

similarItemsPerItem - number of similar items to compute per item

Method Detail

getRecommender

protected ItemBasedRecommender getRecommender()

getSimilarItemsPerItem

protected int getSimilarItemsPerItem()

computeItemSimilarities

public abstract int computeItemSimilarities(int degreeOfParallelism,
                                            int maxDurationInHours,
                                            SimilarItemsWriter writer)
                                     throws IOException

Parameters:

degreeOfParallelism - number of threads to use for the computation

maxDurationInHours - maximum duration of the computation

writer - SimilarItemsWriter used to persist the results

Returns:

the number of similarities precomputed

Throws:

IOException

RuntimeException - if the computation takes longer than maxDurationInHours