r - 如何创建数字循环？

Question

我正在使用 R，想知道是否有人可以帮助我。
我想转换这个向量:

y<-c(1,1,1,1,2,2,3,3,3,4,4,4)

到

y<-c(1,2,3,4,1,2,1,2,3,1,2,3)

所以我可以执行以下操作:

v<-c(rep("a",4), rep("b",2), rep("c",3), rep("d",3)) 
paste (v, y, sep="")
[1] "a1" "a2" "a3" "a4" "b1" "b2" "c1" "c2" "c3" "d1" "d2" "d3"

Answer 1

我很惊讶 ave还没到:

> paste0(letters[y], ave(y, y, FUN=seq_along))
 [1] "a1" "a2" "a3" "a4" "b1" "b2" "c1" "c2" "c3" "d1" "d2" "d3"