执行以下任务的好方法是什么?
我有一个数据框,例如:
v2 <- c(4.5, 2.5, 3.5, 5.5, 7.5, 6.5, 2.5, 1.5, 3.5)
v1 <- c(2.2, 3.2, 1.2, 4.2, 2.2, 3.2, 2.2, 1.2, 5.2)
lvl <- c("a","a","a","b","b","b","c","c","c")
d <- data.frame(v1,v2,lvl)
> d
v1 v2 l
1 2.2 4.5 a
2 3.2 2.5 a
3 1.2 3.5 a
4 4.2 5.5 b
5 2.2 7.5 b
6 3.2 6.5 b
7 2.2 2.5 c
8 1.2 1.5 c
9 5.2 3.5 c
每个级别内d$lvl
,我想按值对数据框进行排序d$v1
。所以我想得到
v1 v2 l
3 1.2 3.5 a
1 2.2 4.5 a
2 3.2 2.5 a
5 2.2 7.5 b
6 3.2 6.5 b
4 4.2 5.5 b
8 1.2 1.5 c
7 2.2 2.5 c
9 5.2 3.5 c