Rbind与列切换相同的data.frame

I am not new to R, but I cannot solve this problem: I have a data.frame and want to rbind the same data.frame with coloumn switching. But R does not switch the columns.

我不是R的新手，但是我无法解决这个问题：我有一个data.frame并希望使用coloumn切换来匹配相同的data.frame。但是R不会切换列。

Example:

例：

set.seed(13)
df <- data.frame(var1 = sample(5), var2 = sample(5))
> df
  var1 var2
1    4    1
2    1    3
3    2    4
4    5    2
5    3    5

> rbind(df, df[,c(2,1)])
   var1 var2
1     4    1
2     1    3
3     2    4
4     5    2
5     3    5
6     4    1
7     1    3
8     2    4
9     5    2
10    3    5

As you can see, the coloumns are not switched (row 6-10) whereas switching the columns alone works like a charm:

如你所见，coloumns没有切换（第6-10行），而单独切换列就像一个魅力：

> df[,c(2,1)]
  var2 var1
1    1    4
2    3    1
3    4    2
4    2    5
5    5    3

I guess this has something to do with the column names, but I cannot figure out what exacly.

我想这与列名有关，但我无法弄清楚什么是exacly。

Can anyone help?

有人可以帮忙吗？

Kind regards!

亲切的问候！

1 个解决方案

#1

As pointed out by @Henrik, from ?rbind.data.frame: "The rbind data frame method [...] matches columns by name. So try this:

正如@Henrik所指出的，来自？rbind.data.frame：“rbind数据框方法[...]按名称匹配列。所以试试这个：

> rbind(df, setNames(df[,c(2,1)], c("var1", "var2")))
   var1 var2
1     4    1
2     1    3
3     2    4
4     5    2
5     3    5
6     1    4
7     3    1
8     4    2
9     2    5
10    5    3

this also works:

这也有效：

> rbind(as.matrix(df), as.matrix(df[,c(2,1)]))

#1