Spark 编程工具类与工具方法（一）—— 欧式距离

import org.apache.spark.mllib.linalg.{Vector, Vectors}

def euclidean(x: Vector, y: Vector) = {
  math.sqrt(x.toArray.zip(y.toArray).
    map(p => p._1 - p._2).map(d => d*d).sum)
}