在R中按升序对列的值进行排序

下面的脚本是一个四列的数据框。我的需要是我想一次获取一对值（a1，a2）。 “a3”列是这样的，如果您检查一对（a1，a2），当您跨越数据时，该对的值按升序排列。如果表中存在该对的重复项，我希望“a4”列值按照特定 (a1,a2) 值的升序排列，就像相应的“a3”列一样。假设第一个 (a1,a2) 对（“A”，“D”），该对出现三次，对应的 a3 值按升序排列。同样，我希望根据 a4 值的升序排列 a4 值。请检查预期结果。谢谢并请建议。

a1 = c("A","B","C","A","B","C","A","C")
a2 = c("D","E","F","D","E","E","D","F")
a3 = c(5,15,12,10,40,35,20,50)
a4 = c(100,160,66,65,130,150,80,49)
a123= data.frame(a1,a2,a3,a4)
library(dplyr)
a123_r <- a123 %>%
group_by(a1, a2) %>%
mutate(a3 = sort(a3)) %>%
ungroup()
a123_r   

预期输出

a1 = c("A","B","C","A","B","C","A","C")
a2 = c("D","E","F","D","E","E","D","F")
a3 = c(5,15,12,10,40,35,20,50)
a4 = c(65,130,66,80,160,150,100,49)
a123_r <- data.frame(a1,a2,a3,a4)

为了完整起见，这里是一个使用的答案data.table:

library(data.table)
cols <- c("a3", "a4")
setDT(a123)[, (cols) := lapply(.SD, sort), by = .(a1, a2), .SDcols = cols][]

   a1 a2 a3  a4
1:  A  D  5  65
2:  B  E 15 130
3:  C  F 12  49
4:  A  D 10  80
5:  B  E 40 160
6:  C  E 35 150
7:  A  D 20 100
8:  C  F 50  66

Data

a1 = c("A","B","C","A","B","C","A","C")
a2 = c("D","E","F","D","E","E","D","F")
a3 = c(5,15,12,10,40,35,20,50)
a4 = c(100,160,66,65,130,150,80,49)
a123= data.frame(a1,a2,a3,a4)