如何将虚拟变量转换为R中的因子？

在我的数据框架（称为调查）中，有一个变量称为“答案”

我想把这些虚拟变量转换成

     answer
       NO
       YES
       NO
       YES

我应该对调查$answer数据应用什么命令

实际上我想做的是用lattice可视化数据

   barchart(as.factor(with(survey, survey$answer)))

上面的命令确实生成了条形图，但我需要将标签更改为“是”和“否”，而不是“2”和“1”。这就是为什么我需要转换虚拟变量

   answer<-ifelse(answer==1,"NO","YES")
> answer
[1] "NO"  "YES" "NO"  "YES"

> as.factor(answer)
[1] No  YES No  YES
Levels: No YES

---

使用

因子

函数，如下所示：

> answer <- c(1,2,1,2)
> answer <- factor(answer, labels=c("NO", "YES"))
[1] NO  YES NO  YES
Levels: NO YES

---

>answer-answerMetrics的答案将为您提供一个字符变量。作为一个因素：

answer <- rep(1:2,2)
answer <- as.factor(answer)
levels(answer) <- c("NO","YES")

答案为了好玩，这里有另一个选择。转换为因子并不麻烦，但这对于条形图来说也是不必要的：

set.seed(1)
x <- sample(2, 50, replace = TRUE)
x
#  [1] 1 1 2 2 1 2 2 2 2 1 1 1 2 1 2 1 2 2 1 2 2 1 2 1 1 1 1 1 2 1 1 2
# [33] 1 1 2 2 2 1 2 1 2 2 2 2 2 2 1 1 2 2
c("NO", "YES")[x]
#  [1] "NO"  "NO"  "YES" "YES" "NO"  "YES" "YES" "YES" "YES" "NO" 
# [11] "NO"  "NO"  "YES" "NO"  "YES" "NO"  "YES" "YES" "NO"  "YES"
# [21] "YES" "NO"  "YES" "NO"  "NO"  "NO"  "NO"  "NO"  "YES" "NO" 
# [31] "NO"  "YES" "NO"  "NO"  "YES" "YES" "YES" "NO"  "YES" "NO" 
# [41] "YES" "YES" "YES" "YES" "YES" "YES" "NO"  "NO"  "YES" "YES"

library(lattice)
barchart(c("NO", "YES")[x])

考虑到您的编辑，您可能应该更改您的问题标题……如果您已经在（调查…）中说了
，则无需说
调查$answer
。“那是多余的！”托马斯，实际上我想知道这两个答案。我的意思是“如何将虚拟变量更改为因子”和“如何编辑条形图标签”。前一个问题是我最感兴趣的。编辑的部分也是一个问题，但这是一个小问题。我认为@Jilber的方法更常见。谢谢，我遵循了你的答案！谢谢你的回答。
set.seed(1)
x <- sample(2, 50, replace = TRUE)
x
#  [1] 1 1 2 2 1 2 2 2 2 1 1 1 2 1 2 1 2 2 1 2 2 1 2 1 1 1 1 1 2 1 1 2
# [33] 1 1 2 2 2 1 2 1 2 2 2 2 2 2 1 1 2 2
c("NO", "YES")[x]
#  [1] "NO"  "NO"  "YES" "YES" "NO"  "YES" "YES" "YES" "YES" "NO" 
# [11] "NO"  "NO"  "YES" "NO"  "YES" "NO"  "YES" "YES" "NO"  "YES"
# [21] "YES" "NO"  "YES" "NO"  "NO"  "NO"  "NO"  "NO"  "YES" "NO" 
# [31] "NO"  "YES" "NO"  "NO"  "YES" "YES" "YES" "NO"  "YES" "NO" 
# [41] "YES" "YES" "YES" "YES" "YES" "YES" "NO"  "NO"  "YES" "YES"

library(lattice)
barchart(c("NO", "YES")[x])