向量距离 / Vector Distance
向量计算方法总结：
https://www.cnblogs.com/liujinhong/p/6001997.html
https://blog.csdn.net/tagsT/article/details/50214669
github资源：
https://github.com/mljs/distance
机器学习-距离计算（A new typology design of performance metrics to measure errors in machine learning regression algorithms）：
