STATA方法：https://mp.weixin.qq.com/s?__biz=MzIzNjk2NDg4NA==&mid=2247484583&idx=1&sn=96fc1c5e08032893d3da41dfe4a1a6c9&chksm=e8ce99dcdfb910ca23c8be420b04c1a43fa68deb74e3d2ff01617db2c40ec7359fa8bf374af7&token=252771355&lang=zh_CN#rd

R软件的很多程序包的函数都可以实现：https://mp.weixin.qq.com/s?__biz=MzIzNjk2NDg4NA==&mid=2247484593&idx=1&sn=8aad239ecd2579eb9575741d4e7186a3&chksm=e8ce99cadfb910dc67be70c783e03cd55d4cdd5fda17716ba18c69df0e745576c3746ad732d1&token=252771355&lang=zh_CN#rd

thanks for sharing