Q:

Exception: Filter didn't make the test instance immediately available

I am using the classifier FilteredClassifier in WEKA. The Filter of my classifier is a MultiFilter, doing first InfoGain, and then Standarization.  After training the classifier, when trying to classify the test instances on the fly, I get the error: java.lang.Exception: Filter didn't mkae the test instance immediately available!
Anyone knows how to fix this?

A:

Add a ClassAssigner filter at the end of your MultiFilter array. When Info gain changes the number of attributes, the class index isn't updated, so you're getting array out of bounds errors.

