private void updateAverageCenter() {
for (int i = 0; i < classCount.size(); i++) {
HashSparseVector center = classCenter.get(i);
int count = classCount.get(i);
center.scaleDivide((float) count);
}
}
private void clusterList(ArrayList<TrainInstance> trainData) {
for (TrainInstance ele : trainData) {