我有一个Spring Web应用程序。它通过Hibernate Search将模型Education映射到Lucene索引中：
@Entity@Table(name="educations")@Indexedpublic class Education { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Field(termVector = TermVector.WITH_POSITION_OFFSETS) private long id; @Column(name = "name") @Field(termVector = TermVector.WITH_POSITION_OFFSETS) @Boost(value = 1.5f) private String name; @Column(name = "local_name") private String localName; @Column(name = "description", columnDefinition="TEXT") @Field(termVector = TermVector.WITH_POSITION_OFFSETS) private String description;这运行得很好！
现在我试图通过Mahout 0.9对我的Lucene索引进行聚类。我已经实现了一个基本的K-means聚类，但不知道如何将我的Lucene索引转换为Mahout向量。
这是我使用一些测试数据点的工作的基本K-Means聚类类，如下所示：
package com.courseportal.project.utils.lsh.util;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.FileSystem;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.IntWritable;import org.apache.hadoop.io.LongWritable;import org.apache.hadoop.io.SequenceFile;import org.apache.hadoop.io.Text;import org.apache.mahout.clustering.Cluster;import org.apache.mahout.clustering.classify.WeightedPropertyVectorWritable;import org.apache.mahout.clustering.kmeans.KMeansDriver;import org.apache.mahout.clustering.kmeans.Kluster;import org.apache.mahout.common.distance.EuclideanDistanceMeasure;import org.apache.mahout.math.RandomAccessSparseVector;import org.apache.mahout.math.Vector;import org.apache.mahout.math.VectorWritable;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.List;public class SimpleKMeansClustering { public static final double[][] points = { {1, 1}, {2, 1}, {1, 2}, {2, 2}, {3, 3}, {8, 8}, {9, 8}, {8, 9}, {9, 9}}; public static void writePointsToFile(List<Vector> points, String fileName, FileSystem fs, Configuration conf) throws IOException { Path path = new Path(fileName); SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, path, LongWritable.class, VectorWritable.class); long recNum = 0; VectorWritable vec = new VectorWritable(); for (Vector point : points) { vec.set(point); writer.append(new LongWritable(recNum++), vec); } writer.close(); } public static List<Vector> getPoints(double[][] raw) { List<Vector> points = new ArrayList<Vector>(); for (int i = 0; i < raw.length; i++) { double[] fr = raw[i]; Vector vec = new RandomAccessSparseVector(fr.length); vec.assign(fr); points.add(vec); } return points; } public static void main(String args[]) throws Exception { int k = 2; List<Vector> vectors = getPoints(points); File testData = new File("clustering/testdata"); if (!testData.exists()) { testData.mkdir(); } testData = new File("clustering/testdata/points"); if (!testData.exists()) { testData.mkdir(); } Configuration conf = new Configuration(); FileSystem fs = FileSystem.get(conf); writePointsToFile(vectors, "clustering/testdata/points/file1", fs, conf); Path path = new Path("clustering/testdata/clusters/part-00000"); SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, path, Text.class, Kluster.class); for (int i = 0; i < k; i++) { Vector vec = vectors.get(i); Kluster cluster = new Kluster(vec, i, new EuclideanDistanceMeasure()); writer.append(new Text(cluster.getIdentifier()), cluster); } writer.close(); KMeansDriver.run(conf, new Path("clustering/testdata/points"), new Path("clustering/testdata/clusters"), new Path("clustering/output"), 0.001, 10, true, 0, true); SequenceFile.Reader reader = new SequenceFile.Reader(fs, new Path("clustering/output/" + Cluster.CLUSTERED_POINTS_DIR + "/part-m-0"), conf); IntWritable key = new IntWritable(); WeightedPropertyVectorWritable value = new WeightedPropertyVectorWritable(); while (reader.next(key, value)) { System.out.println(value.toString() + " belongs to cluster " + key.toString()); } reader.close(); }}我读到（这里）我应该使用LuceneIndexToSequenceFiles来做这件事，但我在Mahout 0.9中找不到这个类。这是我需要手动引入的吗？
我如何将我的索引转换为与我的K-means聚类类一起使用？
回答：
你可以使用package org.apache.mahout.text;和类SequenceFilesFromLuceneStorageMRJob（用于分布式转换）或SequenceFilesFromLuceneStorageDriver。
关于它们的使用方法，你可以在mahout-0.9的测试中找到更多信息。例如这里：
mahout-0.9/integration/src/test/java/org/apache/mahout/text/SequenceFilesFromLuceneStorageDriverTest.javamahout-0.9/integration/src/test/java/org/apache/mahout/text/SequenceFilesFromLuceneStorageMRJob.java以及这里 https://mahout.apache.org/users/basics/creating-vectors-from-text.html
重要提示：你的Lucene索引必须使用与Mahout中使用的Lucene相同版本创建。
