# rep(x, …):将vector x的值循环n遍
rep(1:4, 2)
[1] 1 2 3 4 1 2 3 4
# times:整个数组循环几遍
rep(1:4, each = 2, times = 3)
[1] 1 1 2 2 3 3 4 4 1 1 2 2 3 3 4 4 1 1 2 2 3 3 4 4
# each:每个element循环几遍
rep(1:4, each = 2)
[1] 1 1 2 2 3 3 4 4
rep(1:4, c(2,2,2,2))
[1] 1 1 2 2 3 3 4 4
rep(1:4, c(2,1,2,1))
[1] 1 1 2 3 3 4
# length.out 输出长度为多少
rep(1:4, each = 2, len = 4)
[1] 1 1 2 2 #长了会被截掉
rep(1:4, each = 2, len = 13)
[1] 1 1 2 2 3 3 4 4 1 1 2 2 3 #短了会根据前面规则补上
原文:https://www.cnblogs.com/suwen-lu/p/14492756.html