mahout实现查准率和查全率评估的配置与运行，mahout查准率

mahout实现查准率和查全率评估的配置与运行，mahout查准率

/*
 * 查准率和查全率评估的配置与运行
 * 
 * */
package byuser;

import java.io.File;

import org.apache.mahout.cf.taste.common.TasteException;
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.eval.GenericRecommenderIRStatsEvaluator;
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.GenericUserBasedRecommender;
import org.apache.mahout.cf.taste.impl.similarity.PearsonCorrelationSimilarity;
import org.apache.mahout.cf.taste.model.DataModel;
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 org.apache.mahout.common.RandomUtils;


public class RecommenderIRStatsEvaluatorTest {

	public RecommenderIRStatsEvaluatorTest(){
		try{
			RandomUtils.useTestSeed();
			DataModel model = new FileDataModel(new File("E:\\mahout项目\\examples\\intro.csv"));
			RecommenderIRStatsEvaluator evaluator = new GenericRecommenderIRStatsEvaluator();
			RecommenderBuilder recommenderBuilder = new RecommenderBuilder() {
				@Override
				public Recommender buildRecommender(DataModel model) throws TasteException {
					// TODO Auto-generated method stub
					UserSimilarity similarity = new PearsonCorrelationSimilarity(model);
					UserNeighborhood neighborhood = new NearestNUserNeighborhood(2, similarity, model);
					return new GenericUserBasedRecommender(model, neighborhood, similarity);
				}
			};
			//推荐两个数据
			IRStatistics stats = evaluator.evaluate(recommenderBuilder, null, model, null, 2, GenericRecommenderIRStatsEvaluator.CHOOSE_THRESHOLD, 1.0);
			System.out.println("推荐两个结果的查准率 ：" + stats.getPrecision());
			System.out.println("推荐两个结果的查全率 ：" + stats.getRecall());
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		RecommenderIRStatsEvaluatorTest test = new RecommenderIRStatsEvaluatorTest();
	}

}

结果：