删除每个ID的低值行

Question

我有一个包含三个变量的数据，我希望将id行保持为高“value”，并删除每个id的“value”值较低的行。

我有什么

mydata <- data.frame(id=c(1,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,4), case=c("a","b","c","c","b","a","b","c","c","a","b","c","c","a","b","c","a","b"), value=c(1,1,1,2,2,1,1,2,2,2,2,1,1,1,1,1,2,2))

我需要什么

    id case value
4   1   c   2
5   1   b   2
8   2   c   2
9   2   c   2
10  3   a   2
11  3   b   2
17  4   a   2
18  4   b   2

谢谢！

Answer 1

尝试：

    mydata[mydata$value==ave(mydata$value,mydata$id,FUN=max),]

Answer 2

mydata[mydata$value>1,]

或

mydata[mydata$value>min(mydata$value),]