import scala.collection.JavaConversions._
import org.apache.commons.math3.ml.clustering._
val kmeans = new KMeansPlusPlusClusterer[DoublePoint](3)
val points = (1 to 90).map{ x =>
   if (x< 30) new DoublePoint(Array(1+1.0/x, 1+1.0/x))
   else if (x<60) new DoublePoint(Array(10+ 1.0/x, 10+1.0/x))
   else new DoublePoint(Array(20+1.0/x, 20+1.0/x))
}
val centroids = kmeans.cluster(points.toIterable)
centroids.map{ x=> x.getCenter.getPoint }