r - 如何在 R 中的数据框中重新编码数据

Question

可以推广到多列的数据示例如下

id  colour  zm          cinema  pen     wm          monitor mn
1   blue    good        a       wood    bad         24      very good
2   Yellow  bad         b       metal   good enough 23      good
3   Red     good enough d       plastic bad         27      good enough

我要得到下表

id  colour  zm  cinema  pen     wm  monitor mn
1   blue    B   a       wood    D   34      A
2   Yellow  D   b       metal   C   23      B
3   Red     C   d       plastic D   27      C

非常好= A，好= B，足够好= C，差= D。我知道这可以通过“变异”来完成，但很难在数据框架内完成。

Answer 1

我们可以使用命名向量来改变值

nm1 <- setNames(LETTERS[1:4], c("very good", "good", "good enough", "bad"))
library(dplyr)
df2 <- df1 %>%
     mutate(across(c(zm, wm, mn), ~ nm1[.]))

-输出

df2
#  id colour zm cinema     pen wm monitor mn
#1  1   blue  B      a    wood  D      24  A
#2  2 Yellow  D      b   metal  C      23  B
#3  3    Red  C      d plastic  D      27  C

数据

df1 <- structure(list(id = 1:3, colour = c("blue", "Yellow", "Red"), 
    zm = c("good", "bad", "good enough"), cinema = c("a", "b", 
    "d"), pen = c("wood", "metal", "plastic"), wm = c("bad", 
    "good enough", "bad"), monitor = c(24L, 23L, 27L), mn = c("very good", 
    "good", "good enough")), class = "data.frame", row.names = c(NA, 
-3L))