R 自定义排序（非字母顺序）

我有一个分类数据集，看起来类似于：

A < -data.frame(animal = c("cat","cat","cat","dog","dog","dog","elephant","elephant","elephant"),
                color = c(rep(c("blue","red","green"), 3)))

    animal color
1      cat  blue
2      cat   red
3      cat green
4      dog  blue
5      dog   red
6      dog green
7 elephant  blue
8 elephant   red
9 elephant green

---

应明确规定等级：

A$animal <- factor(A$animal, levels = c("dog", "elephant","cat"))
A$color <- factor(A$color, levels = c("green", "blue", "red"))

---

另一件值得注意的事情是，您不必转换类来实现这一点。您可以简单地按变量的因子排序。因此，如果需要的话，在现有数据结构中保留为eg字符类

例如，使用上面的例子：

A[order(factor(A$animal, levels = c("dog", "elephant","cat")) ,factor(A$color, levels = c("green", "blue", "red"))),]

---

这取决于阶级的保守是否重要。对于我个人来说，这将是一个更典型的用例。HTH

您也可以使用

匹配

-您既不更改列类，也不执行

因子

转换

animalOrder = c("dog", "elephant","cat")
colorOrder  = c("green", "blue", "red")
A[ order(match(A$animal, animalOrder), match(A$color, colorOrder)), ]

animal color
6      dog green
4      dog  blue
5      dog   red
9 elephant green
7 elephant  blue
8 elephant   red
3      cat green
1      cat  blue
2      cat   red

以类似的方式，我将以“tidyverse”的方式呈现订单：

A$animal <- factor(A$animal, levels = c("dog", "elephant","cat"))
A$color <- factor(A$color, levels = c("green", "blue", "red"))

或者干脆

A %>% arrange(animal, color)

其中，

%%>%%

是r中的“管道”操作符，可以通过使用

Ctrl

+

Shift

+

m

A$animal <- factor(A$animal, levels = c("dog", "elephant","cat"))
A$color <- factor(A$color, levels = c("green", "blue", "red"))

arrange(A, animal, color)

A %>% arrange(animal, color)