根据给定的因子水平，从数据框中选择具有匹配因子水平的变量/列。

Question

是否可以通过匹配某些因子水平来选择数据框中的变量，根据它们的因子水平（已使用或未使用）选择列？我可以通过按级别总结或可能按行子集，但我想知道是否可以从数据框中选择列，或者至少列出具有某些因子水平的变量/列。

library(dplyr)
height <- c(132,151,162,139,166,147,122)
    weight <- c(48,49,66,53,67,52,40)
    gender <- c("male","male","female","female","male","female","male")
    gender2 <- c("female","male","male","male","male","female","male")
    genderx <- c("xfemale","malex","malex","male","male","xfemale","xfemale")


    df <- data.frame(height,weight,gender, gender2, genderx) %>% 
      rowid_to_column(., "ID")

类似于（或不类似）

%>% select (vars(levels ==(c("male", "female")))

- 23stacks1254

Answer 1

我们可以使用select_if。

library(dplyr)
df %>% 
    select_if(~ is.factor(.) && all(c("male", "female") %in% levels(.)))

或者它也可以是任何

df %>% 
    select_if(~ is.factor(.) && any(c("male", "female") %in% levels(.)))

- akrun

---

非常感谢 @akrun。 - 23stacks1254