R 如何优雅地将因子标签传输到另一个变量？

令人惊讶的是，我一直没能找到解决办法。假设我有两个变量：

gender1 <- sample(0:1, 20, replace = TRUE)
gender2 <- sample(0:1, 20, replace = TRUE)
gender2[gender2==1] <- 2

gender1[gender1==1] <- 3

gender1 <- factor(gender1, levels = c(0, 1, 2, 3), labels = c("Male", "Female", "Intersex", "Other"))

---

gender1将
gender2
作为.factor

并分配

`levels将
gender2
作为.factor

并分配

`levelsTry
levels（factor1）=levels（factor2）
不起作用。它添加级别但不标记值stry
levels（factor1）=levels（factor2）
不起作用。它添加级别，但不标记值
gender2 <- `attr<-`(`levels<-`(as.factor(gender2), seq(levels(gender1)) - 1),
                    "levels", levels(gender1))

stopifnot(all.equal(levels(gender1), levels(gender2)))

set.seed(42)
gender1 <- sample(c(0, 2), 20, replace=TRUE)
gender2 <- sample(c(0, 3), 20, replace=TRUE)

gender1 <- factor(gender1, levels=0:3, labels=c("Male", "Female", "Intersex", "Other"))