摘要: df=data.frame( Y=c(101,101,100,99,201,201,200,199,51,51,50,49), X2=c("1","1","1",'1','2','2','2','2','3','3','3','3'), X=c(1,1,1,1,2,2,2,2,3,3,3,3), R 阅读全文
posted @ 2021-07-11 22:50 esctrionsit 阅读(652) 评论(0) 推荐(0) 编辑