Question

您好我试图在第7章（k-Mean Clustering）中运行Mahout的示例。有人可以指导我如何在带有Mahout（0.7）的Hadoop集群（单节点CDH-4.2.1）中运行该示例

这是我遵循的步骤：

将代码（从Github）复制到我的本地计算机上的Eclipse IDE中。
将这些罐子插入我的Eclipse项目中。

Hadoop的共2.0.0-cdh4.2.1.jar

Hadoop的HDFS-2.0.0-cdh4.2.1.jar

Hadoop的MapReduce的客户端 - 芯2.0.0-cdh4.2.1.jar

象夫核-0.7-cdh4.3.0.jar

象夫核-0.7-cdh4.3.0-job.jar

象夫-数学0.7 cdh4.3.0.jar

制作了这个项目的Jar并将该jar复制到我的Hadoop集群
执行此命令

user @ INFPH01463U：〜$ hadoop jar /home/user/apurv/Kmean.jar tryout.SimpleKMeansClustering

给了我以下错误

Exception in thread "main" java.lang.NoClassDefFoundError: FileSystem
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
        at java.lang.Class.getMethod0(Class.java:2670)
        at java.lang.Class.getMethod(Class.java:1603)
        at org.apache.hadoop.util.RunJar.main(RunJar.java:202)
Caused by: java.lang.ClassNotFoundException: FileSystem
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
        ... 5 more

任何人都可以帮助我解决我错过的问题或我的执行方式错误吗？

其次，我想知道如何在CSV文件上运行K-mean Clustering？

提前致谢：）

Answer 1

给定的代码具有误导性，代码

Cluster cluster = new Cluster(vec, i, new EuclideanDistanceMeasure());
    writer.append(new Text(cluster.getIdentifier()), cluster);
}
writer.close();

KMeansDriver.run(conf, new Path("testdata/points"), new Path("testdata/clusters"),
  new Path("output"), new EuclideanDistanceMeasure(), 0.001, 10,
  true, false);

SequenceFile.Reader reader = new SequenceFile.Reader(fs,
    new Path("output/" + Cluster.CLUSTERED_POINTS_DIR
             + "/part-m-00000"), conf);

应替换为

Kluster cluster = new Kluster(vec, i, new EuclideanDistanceMeasure());
    writer.append(new Text(cluster.getIdentifier()), cluster);
}
writer.close();

KMeansDriver.run(conf, new Path("testdata/points"), new Path("testdata/clusters"),
  new Path("output"), new EuclideanDistanceMeasure(), 0.001, 10,
  true, false);

SequenceFile.Reader reader = new SequenceFile.Reader(fs,
    new Path("output/" + Kluster.CLUSTERED_POINTS_DIR
             + "/part-m-00000"), conf);

Cluster是一个接口，而Kluster是一个类。有关详细信息，请查看Mahout API Javadoc。

要使用csv文件运行kmeans，首先必须创建一个SequenceFile作为KmeansDriver中的参数传递。以下代码读取CSV文件“points.csv”的每一行并将其转换为vector并将其写入SequenceFile“points.seq”

try (
            BufferedReader reader = new BufferedReader(new FileReader("testdata2/points.csv"));
            SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf,new Path("testdata2/points.seq"), LongWritable.class, VectorWritable.class)
        ) {
            String line;
            long counter = 0;
            while ((line = reader.readLine()) != null) {
                String[] c = line.split(",");
                if(c.length>1){
                    double[] d = new double[c.length];
                    for (int i = 0; i < c.length; i++)
                            d[i] = Double.parseDouble(c[i]);
                    Vector vec = new RandomAccessSparseVector(c.length);
                    vec.assign(d);

                VectorWritable writable = new VectorWritable();
                writable.set(vec);
                writer.append(new LongWritable(counter++), writable);
            }
        }
        writer.close();
    }

希望它有所帮助!!

如何从Mahout中运行Kmean Clustering？

1 个答案: