code: public double calcKMeansCosts(double[] center, double[] point) {
  		assert (this.sumPoints.length == center.length &&
  				this.sumPoints.length == point.length);
  		return (this.sumSquaredLength + Metric.distanceSquared(point)) - 2
  				* Metric.dotProductWithAddition(this.sumPoints, point, center)
  				+ (this.numPoints + 1) * Metric.dotProduct(center);
  	}
docs: Calculates the k-means costs of the ClusteringFeature and a point too a
  center.
  
  @param center
  the center too calculate the costs
  @param point
  the point too calculate the costs
  @return the costs