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via Stack Overflow by Kerim Caner Tümkaya
, 1 year ago
weka.core.UnassignedClassException: Class index is negative (not set)!	at weka.core.Instances.numClasses(Instances.java:915)	at weka.classifiers.evaluation.Evaluation.(Evaluation.java:461)	at weka.classifiers.evaluation.Evaluation.(Evaluation.java:441)	at weka.classifiers.Evaluation.(Evaluation.java:211)	at weka1.Weka1.classify(Weka1.java:84)	at weka1.Weka1.main(Weka1.java:193)