package mia.recommender.ch03;
import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.cf.taste.eval.DataModelBuilder;
import org.apache.mahout.cf.taste.eval.IRStatistics;
import org.apache.mahout.cf.taste.eval.RecommenderBuilder;
import org.apache.mahout.cf.taste.eval.RecommenderIRStatsEvaluator;
import org.apache.mahout.cf.taste.impl.common.FastByIDMap;
import org.apache.mahout.cf.taste.impl.eval.GenericRecommenderIRStatsEvaluator;
import org.apache.mahout.cf.taste.impl.model.GenericBooleanPrefDataModel;
import org.apache.mahout.cf.taste.impl.model.file.FileDataModel;
import org.apache.mahout.cf.taste.impl.neighborhood.NearestNUserNeighborhood;
import org.apache.mahout.cf.taste.impl.recommender.GenericBooleanPrefUserBasedRecommender;
import org.apache.mahout.cf.taste.impl.similarity.LogLikelihoodSimilarity;
import org.apache.mahout.cf.taste.model.DataModel;
import org.apache.mahout.cf.taste.model.PreferenceArray;
import org.apache.mahout.cf.taste.neighborhood.UserNeighborhood;
import org.apache.mahout.cf.taste.recommender.Recommender;
import org.apache.mahout.cf.taste.similarity.UserSimilarity;
import java.io.File;
class IREvaluatorBooleanPrefIntro2 {
private IREvaluatorBooleanPrefIntro2() {
}
public static void main(String[] args) throws Exception {
DataModel model = new GenericBooleanPrefDataModel(
GenericBooleanPrefDataModel.toDataMap(
new FileDataModel(new File("ua.base"))));
RecommenderIRStatsEvaluator evaluator =
new GenericRecommenderIRStatsEvaluator();
RecommenderBuilder recommenderBuilder = new RecommenderBuilder() {
@Override
public Recommender buildRecommender(DataModel model) throws TasteException {
UserSimilarity similarity = new LogLikelihoodSimilarity(model);
UserNeighborhood neighborhood =
new NearestNUserNeighborhood(10, similarity, model);
return new GenericBooleanPrefUserBasedRecommender(model, neighborhood, similarity);
}
};
DataModelBuilder modelBuilder = new DataModelBuilder() {
@Override
public DataModel buildDataModel(FastByIDMap<PreferenceArray> trainingData) {
return new GenericBooleanPrefDataModel(
GenericBooleanPrefDataModel.toDataMap(trainingData));
}
};
IRStatistics stats = evaluator.evaluate(
recommenderBuilder, modelBuilder, model, null, 10,
GenericRecommenderIRStatsEvaluator.CHOOSE_THRESHOLD,
1.0);
System.out.println(stats.getPrecision());
System.out.println(stats.getRecall());
}
}