title: java help with weka: UnsupportedAttributeTypeException
body: <p>So I'm working with the Weka Machine Learning Library in Java...</p>
  
  <p>I was trying to implement this: <a href="http://weka.wikispaces.com/Text+categorization+with+Weka" rel="nofollow">http://weka.wikispaces.com/Text+categorization+with+Weka</a></p>
  
  <p>at the bottom you can download TextCategorizationTest.java which does text categorization and the text_example.zip which contains a whole bunch of htmls....</p>
  
  <p>so I tried running TextCategorizationTest using the class1 directory in the text_example as argument....but then I encountered this error: </p>
  
  <pre><code>Exception in thread "main" weka.core.UnsupportedAttributeTypeException: weka.classifiers.trees.j48.C45PruneableClassifierTree: Cannot handle multi-valued nominal class!
      at weka.core.Capabilities.test(Capabilities.java:936)
      at weka.core.Capabilities.test(Capabilities.java:1105)
      at weka.core.Capabilities.test(Capabilities.java:1018)
      at weka.core.Capabilities.testWithFail(Capabilities.java:1297)
      at weka.classifiers.trees.j48.C45PruneableClassifierTree.buildClassifier(C45PruneableClassifierTree.java:116)
      at weka.classifiers.trees.J48.buildClassifier(J48.java:236)
      at TextCategorizationTest.main(TextCategorizationTest.java:55)
  </code></pre>
  
  <p>which refers to this line:</p>
  
  <pre><code>classifier.buildClassifier(dataFiltered);
  </code></pre>
  
  <p>does anybody what's wrong?</p>