同时循环通过2个向量并保存在新向量中

Question

我有2个向量：

index <- as.integer(c(3, 5, 7))
sen <- c("first", "second", "third", "fourth", "fifth", "sixth", "seventh")

我想根据每个字符串的索引将其保存在新向量中：

 mySen <- vector(mode = "character", length = length(index))

这样

> mySen
[1] "third"
[2] "fifth"
[3] "seventh"

我尝试了嵌套循环，但是它们输出长度为6的索引i和j

for (j in index){
  for(i in 1:length(index)){
    print(c(i,j))
  }
}

[1] 1 3
[1] 2 3
[1] 3 3
[1] 1 5
[1] 2 5
[1] 3 5
[1] 1 7
[1] 2 7
[1] 3 7

我想要索引

1 3
2 5
3 7

最重要的是，我希望我的新向量mySen能够如前所述正确地填充

> mySen
[1] "third"
[2] "fifth"
[3] "seventh"

Answer 1

您可以将sen与index子集

mySen <- sen[index]
mySen
#[1] "third"   "fifth"   "seventh"