决策树分类器不起作用

Question

使用DT分类器时遇到以下错误

Exception in thread "main" net.sf.javaml.tools.weka.WekaException: java.lang.IllegalArgumentException: Value not defined for given nominal attribute!
        at net.sf.javaml.tools.weka.WekaClassifier.classify(WekaClassifier.java:43)
        at psofc2.MyClassifier.classify(MyClassifier.java:98)
        at psofc2.TestingWithClassifier.fc(TestingWithClassifier.java:52)
        at psofc2.Main.main(Main.java:295)
Caused by: java.lang.IllegalArgumentException: Value not defined for given nominal attribute!
        at weka.core.Instance.setValue(Unknown Source)
        at weka.core.Instance.setClassValue(Unknown Source)
        at net.sf.javaml.tools.weka.ToWekaUtils.instanceToWeka(ToWekaUtils.java:87)
        at net.sf.javaml.tools.weka.WekaClassifier.classify(WekaClassifier.java:41)
        ... 3 more

有人可以帮忙吗 谢谢