如果在单独的列中满足条件，则重命名因子变量

Question

我有一个看起来像这样的 df:

df <- data.frame(
    A = sample(c("Dog", "Cat", "Cat", "Dog", "Fish", "Fish")),
    B = sample(c("Brown", "Black", "Brown", "Black", "Brown", "Black")))
df

   A      B     
1  Dog    Brown
2  Cat    Black
3  Cat    Brown
4  Dog    Black
5  Fish   Brown
6  Fish   Black

每当第二列中满足条件 "Brown" 时，我想重命名（最好使用 dplyr）因子变量 "Fish" 为 "Dog"。

   A      B     
1  Dog    Brown
2  Cat    Black
3  Cat    Brown
4  Dog    Black
5  Dog    Brown  #rename here
6  Fish   Black

Answer 1

您可以使用 replace:

df %>% mutate(A = replace(A, which(A == "Fish" & B == "Brown"), "Dog"))
#     A     B
#1  Cat Black
#2 Fish Black
#3  Dog Black
#4  Dog Brown
#5  Cat Brown
#6  Dog Brown

这是一个 data.table 版本：

library(data.table)
setDT(df)[A == "Fish" & B == "Brown", A := "Dog"]

如果在单独的列中满足条件，则重命名因子变量

Renaming factor variables if a condition is satisfied in separate column

r

dplyr