我已经实现了一个Apache Mahout应用程序(附带下文),它执行一些基本的计算。为此,需要从本地计算机加载数据集。此应用程序以jar文件的形式出现,但随后在hadoop伪分布式集群中执行。终端命令是:$ hadoop jar /home/eualin/ApacheMahout/tdunning-MiA-5b8956f/target/mia-0.1-jar-with-dependencies.jar mia.recommender.ch03.IREvaluatorBooleanPrefIntro2“/ home / eualin / Desktop /链接决赛“
现在,我的问题是如何做同样的事情,但这次是通过从HDFS读取数据集(当然,我们假设数据集已经存储在HDFS中,例如/ user / eualin / output / links -final}。在这种情况下应该改变什么?这可能会有所帮助:hdfs:// localhost:50010 / user / eualin / output / links-final
package mia.recommender.ch03;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
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;
public class IREvaluatorBooleanPrefIntro2 {
private IREvaluatorBooleanPrefIntro2() {
}
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.out.println("give file's HDFS path");
System.exit(1);
}
DataModel model = new GenericBooleanPrefDataModel(
GenericBooleanPrefDataModel.toDataMap(
new GenericBooleanPrefDataModel(new FileDataModel(new File(args[0])))));
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());
}
}
答案 0 :(得分:0)
您不能直接,因为非分布式代码不了解HDFS。而是将文件复制到setup()
中的本地位置,然后从本地文件中读取它。