我试图计算维基百科文档之间的行相似性。我有tf-idf向量的格式 Key class: class org.apache.hadoop.io.Text Value Class: class org.apache.mahout.math.VectorWritable . 下面是文本分析的快速教程：https://cwiki.apache.org/confluence/display/mahout/quick+tour+of+text+analysis+using+the+mahout+command+line
我创建了一个mahout矩阵，如下所示：

mahout rowid \
   -i wikipedia-vectors/tfidf-vectors/part-r-00000
   -o wikipedia-matrix

我得到了生成的行和列的数量：

vectors.RowIdJob: Wrote out matrix with 4587604 rows and 14121544 columns to wikipedia-matrix/matrix

矩阵的格式是 Key class: class org.apache.hadoop.io.IntWritable Value Class: class org.apache.mahout.math.VectorWritable 我也有一个 docIndex 文件格式如下： Key class: class org.apache.hadoop.io.IntWritable Value Class: class org.apache.hadoop.io.Text 当我开始工作的时候

mahout rowsimilarity 
   -i wikipedia-matrix/matrix 
   -o wikipedia-similarity 
   -r 4587604
   --similarityClassname SIMILARITY_COSINE
   -m 50
   -ess

我得到以下错误：

13/08/25 15:18:18 INFO mapred.JobClient: Task Id : attempt_201308161435_0364_m_000001_1, Status : FAILED
java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.mahout.math.VectorWritable
    at org.apache.mahout.math.hadoop.similarity.cooccurrence.RowSimilarityJob$VectorNormMapper.map(RowSimilarityJob.java:183)
    at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:648)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:322)
    at org.apache.hadoop.mapred.Child$4.run(Child.java:266)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:396)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1278)
    at org.apache.hadoop.mapred.Child.main(Child.java:260)

有人能帮我解决这个错误吗？我不知道这是从哪里来的 org.apache.hadoop.io.Text 当输入矩阵为格式时 Key class: class org.apache.hadoop.io.IntWritable Value Class: class org.apache.mahout.math.VectorWritable 非常感谢你。
最好的，德拉甘