Question

我正在尝试使用另一个对应的元素映射/替换一个数据帧的元素。让我举一个例子。

我有这个数据框：

rbind(c("a","b","c"),c("b","a","c"),c("c","b","a"))
     [,1] [,2] [,3]
[1,] "a"  "b"  "c" 
[2,] "b"  "a"  "c" 
[3,] "c"  "b"  "a"

这一个：

   rbind(c("a",1),c("b",2),c("c",3))
     [,1] [,2]
[1,] "a"  "1" 
[2,] "b"  "2" 
[3,] "c"  "3"

我怎样才能用1代替所有a，用2代替所有b，用3代替所有c。获得看起来像这样的最终数据框架。

1   2   3
2   1   3
3   2   1

另外，要了解我使用更大的数据集进行此操作。我似乎无法找到正确的方法来做到这一点。

提前谢谢！

Answer 1

创建命名向量会更有意义。然后你可以使用＆＃34; [＆＃34;功能：

  a <- rbind(c("a","b","c"),c("b","a","c"),c("c","b","a"))
  b <- c("a"=1,"b"=2, "c"=3)

> b
a b c 
1 2 3 
> a[] <- b[a]
> a
     [,1] [,2] [,3]
[1,] "1"  "2"  "3" 
[2,] "2"  "1"  "3" 
[3,] "3"  "2"  "1"

Answer 2

不太优雅的答案，但这可以通过重塑来完成。

library(dplyr)
library(tidyr)

key = 
  rbind(c("a",1),c("b",2),c("c",3)) %>%
  as.data.frame %>%
  setNames(c("letter", "number"))

rbind(c("a","b","c"),c("b","a","c"),c("c","b","a")) %>%
  as.data.frame %>%
  mutate(ID = 1:n()) %>%
  gather(variable, letter, -ID) %>%
  left_join(key) %>%
  select(-letter) %>%
  spread(variable, number)

使用相应的数据框

2 个答案: