跨多个列突变答案

【问题标题】：Mutate across multiple columns跨多个列突变
【发布时间】：2021-09-05 23:13:22
【问题描述】：

我想重新编码fruit2 和fruit3 列中的值，而不必为每一列写出重新编码函数。

fruit1<-c("Apples","Oranges","Apples","Grapes","Apples","Oranges")
fruit2<-c("Apples","Oranges","Apples","Grapes","Apples","Oranges")
fruit3<-c("Apples","Oranges","Apples","Grapes","Apples","Oranges")
data<-data.frame(fruit1,fruit2,fruit3, stringsAsFactors = FALSE)%>%
  mutate(fruit2=recode(fruit2, Apples="Apple"),
        fruit3=recode(fruit2, Apples="Apple"),             
                       )

我知道您可以使用 cross 动词跨列执行操作，但我无法让它发挥作用。我到目前为止：

data<-data.frame(fruit1,fruit2,fruit3, stringsAsFactors = FALSE)%>%
  mutate(across(c(fruit2,fruit3)),recode(Apples="Apple"))

任何人都可以建议对代码进行任何编辑以使其正常工作吗？

【问题讨论】：

什么是fruit1？
现在就在那里，初始代码错误

标签： r dplyr

【解决方案1】：

像这样？

library(tidyverse)
fruit1<-c("Apples","Oranges","Apples","Grapes","Apples","Oranges")
fruit2<-c("Apples","Oranges","Apples","Grapes","Apples","Oranges")
fruit3<-c("Apples","Oranges","Apples","Grapes","Apples","Oranges")
data<-data.frame(fruit1,fruit2,fruit3, stringsAsFactors = FALSE)
data %>%
  mutate(across(c(fruit2, fruit3), ~ recode(.x, Apples="Apple")))
#>    fruit1  fruit2  fruit3
#> 1  Apples   Apple   Apple
#> 2 Oranges Oranges Oranges
#> 3  Apples   Apple   Apple
#> 4  Grapes  Grapes  Grapes
#> 5  Apples   Apple   Apple
#> 6 Oranges Oranges Oranges

【讨论】：

【解决方案2】：

你也可以使用replace

data %>% mutate(across(2:3, ~  replace(., . == 'Apples','Apple')))
   fruit1  fruit2  fruit3
1  Apples   Apple   Apple
2 Oranges Oranges Oranges
3  Apples   Apple   Apple
4  Grapes  Grapes  Grapes
5  Apples   Apple   Apple
6 Oranges Oranges Oranges

【讨论】：