使用字符值作爲對象名稱

Question

我想用中的字符，矢量字符的名稱的對象 目標是獲得

first as say "d","e","a","t" etc. 

嘗試過這種方法，但很顯然缺少一些功能，以適用於X [我]

x <- c("first","second","third"..) 

for (i in 1:length(x)) { 
x[i] <- sample(letters,4) 
} 

TIA

Answer 1

你正在尋找的功能是assign()：

> x <- c("first","second","third") 
> for (i in 1:length(x)) { 
+ assign(x[i], sample(letters,4)) 
+ } 
> 
> ls() 
[1] "first" "i"  "second" "third" "x"  
> first 
[1] "t" "d" "u" "j" 
> second 
[1] "o" "i" "p" "l" 
> third 
[1] "w" "v" "r" "n" 

作爲替代方案，你可以建立這些矢量的列表的不同元素：

> mylist <- list() 
> for (i in 1:length(x)) { 
+ mylist[[x[i]]] <- sample(letters,4) 
+ } 
> mylist 
$first 
[1] "e" "l" "y" "d" 

$second 
[1] "t" "o" "k" "h" 

$third 
[1] "g" "x" "p" "b" 

Answer 2

你不說你會對此對象做什麼。您可以通過使用一個名爲向量得到最簡單的結構：

names(x) <- x 
x[] <- sample(letters, 4) 

如果你不使用的LHS配對支架，整個矢量被替換和名稱都將丟失。您現在可以使用帶引號的名稱訪問這些值：

> x 
first second third fourth 
    "w" "c" "r" "x" 
> x["second"] 
second 
    "c"