while (enumInsts.hasMoreElements()) {
instance = (Instance) enumInsts.nextElement();
docClass = (int)instance.value(classIndex);
//docsPerClass[docClass] += instance.weight();
for(int a = 0; a<instance.numValues(); a++)
if(instance.index(a) != instance.classIndex()) {
if(!instance.isMissing(a)) {
numOccurrences = instance.valueSparse(a) * instance.weight();
if(numOccurrences < 0)
throw new Exception("Numeric attribute"+