Example usage for org.apache.mahout.cf.taste.impl.common FastByIDMap keySetIterator

Introduction

In this page you can find the example usage for org.apache.mahout.cf.taste.impl.common FastByIDMap keySetIterator.

Prototype

public LongPrimitiveIterator keySetIterator() 

Source Link

Usage

From source file:de.tuberlin.dima.recsys.ssnmm.interactioncut.InteractionCutDataModelBuilder.java

License:Apache License

@Override
public DataModel buildDataModel(FastByIDMap<PreferenceArray> trainingData) {

    FastByIDMap<PreferenceArray> sampledTrainingData = new FastByIDMap<PreferenceArray>();

    LongPrimitiveIterator userIDs = trainingData.keySetIterator();
    while (userIDs.hasNext()) {
        long userID = userIDs.nextLong();
        PreferenceArray prefs = trainingData.get(userID);
        if (prefs.length() > maxPrefsPerUser) {
            Preference[] sampledPrefs = Iterators.toArray(
                    new FixedSizeSamplingIterator<Preference>(maxPrefsPerUser, prefs.iterator()),
                    Preference.class);
            sampledTrainingData.put(userID, new GenericUserPreferenceArray(Arrays.asList(sampledPrefs)));
        } else {//from www. j ava2 s  . c  om
            sampledTrainingData.put(userID, prefs);
        }
    }

    return new GenericDataModel(sampledTrainingData);
}

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