R：匹配2个矩阵的字符串的行

Question

我正在处理IP地址数据，并以字符串形式读取数据。为了简单起见，我想出了一个简单的例子。我尝试将矩阵“m”的字符串行与矩阵“abc”中的行匹配。但我一直未能得到正确的输出。

> abc <- matrix(c("dog", "king", "bee", "cat", "apple","eel", "crab", "ball","soap","crazy"), nrow = 5) 
> abc 
    [,1] [,2] 
[1,] "dog" "eel" 
[2,] "king" "crab" 
[3,] "bee" "ball" 
[4,] "cat" "soap" 
[5,] "apple" "crazy" 

> m <- matrix(c("dog", "bee","eel","ball"), nrow = 2) 
> m 
    [,1] [,2] 
[1,] "dog" "eel" 
[2,] "bee" "ball" 

我得到的输出，这犯规任何意义：

> match(data.frame(t(abc)), data.frame(t(m))) 
[1] 1 2 2 1 1 

我期待输出为 [1] 1 NA 2 NA NA

Answer 1

这是一个factor问题，试试这个相反：

match(data.frame(t(abc), stringsAsFactors = F), 
     data.frame(t(m), stringsAsFactors = F)) 
#[1] 1 NA 2 NA NA