R 将字符串向量与 seq_len

Question

如果我有一个字符串列表，x、y、z。我希望将它们与 seq_len 结合起来，因此列表将变为：x1,y1,z1,x2,y2,z2,x3,y3,z3。我怎样才能做到这一点？我试过使用粘贴，但显然不起作用。谢谢。

a1 = c("x","y","z")
seq_len(3)

paste(a1, seq_len(3))

Answer 1

尝试outer

> c(outer(a1, seq_len(3), paste0))
[1] "x1" "y1" "z1" "x2" "y2" "z2" "x3" "y3" "z3"

或sapply

> c(t(sapply(a1,paste0,seq_len(3))))
[1] "x1" "y1" "z1" "x2" "y2" "z2" "x3" "y3" "z3"

Answer 2

paste0(a1, rep(seq_len(3), each = 3))
# [1] "x1" "y1" "z1" "x2" "y2" "z2" "x3" "y3" "z3"

Answer 3

如果您打算直接使用 3 而不是从 al 序列中检索它，有一个简单的答案：

paste0(a1, gl(3, 3))
# "x1" "y1" "z1" "x2" "y2" "z2" "x3" "y3" "z3"

Answer 4

使用 expand.grid 和 paste

do.call(paste0, expand.grid(a1, seq_along(a1)))

R combine a vector of strings with seq_len