Question

这似乎是一个简单的问题，但却让我头痛不已（这不是家庭作业，而是实际研究中的一个难点）

我有一个包含2266个级别的列表。该列表看起来有点像这样：

[1] ~/folder1/folder1/a.bin
[2] ~/folder1/folder1/b.bin
[3] ~/folder1/folder1/c.bin
[4] ~/folder1/folder2/a.bin
[5] ~/folder1/folder2/b.bin
[6] ~/folder1/folder2/c.bin

解释：列表是我使用readBin函数读取的二进制文件的文件名。我想比较每一行和每一行，所以我想要的是两列，其中包含从我的单列派生的所有独特组合。

(choose 2266,2)告诉我，我们的单列有2566245种组合为两种。

`expand.grid()似乎让我走了一半。但是我的组合数量是我需要的四倍：我得到两行5132490.这意味着有重复：1 + 2和2 + 1对我来说是一样的。

带有expand.grid.df的

unique=TRUE似乎也无济于事。

我的最后一个想法是md5散列了500万行中的每一行并试图以这种方式检测重复。

我正在寻找制作两个列表的方法，这些列表涵盖了我的列表的2566245组合。或者删除所有重复项的某种方法。 我想我并不是绝对坚持使用R并调查awk或sed做同样的事情。但是没有成功。

Answer 1

我认为您正在使用@Arun数据寻找combn expand.grid，

v <- c("~/folder1/folder1/a.bin", 
       "~/folder1/folder1/b.bin", 
       "~/folder1/folder1/c.bin", 
       "~/folder1/folder2/a.bin", 
       "~/folder1/folder2/b.bin", 
       "~/folder1/folder2/c.bin")
do.call(rbind,combn(v,2,simplify=F))

    [,1]                      [,2]                     
 [1,] "~/folder1/folder1/a.bin" "~/folder1/folder1/b.bin"
 [2,] "~/folder1/folder1/a.bin" "~/folder1/folder1/c.bin"
 [3,] "~/folder1/folder1/a.bin" "~/folder1/folder2/a.bin"
 [4,] "~/folder1/folder1/a.bin" "~/folder1/folder2/b.bin"
 [5,] "~/folder1/folder1/a.bin" "~/folder1/folder2/c.bin"
 [6,] "~/folder1/folder1/b.bin" "~/folder1/folder1/c.bin"
 [7,] "~/folder1/folder1/b.bin" "~/folder1/folder2/a.bin"
 [8,] "~/folder1/folder1/b.bin" "~/folder1/folder2/b.bin"
 [9,] "~/folder1/folder1/b.bin" "~/folder1/folder2/c.bin"
[10,] "~/folder1/folder1/c.bin" "~/folder1/folder2/a.bin"
[11,] "~/folder1/folder1/c.bin" "~/folder1/folder2/b.bin"
[12,] "~/folder1/folder1/c.bin" "~/folder1/folder2/c.bin"
[13,] "~/folder1/folder2/a.bin" "~/folder1/folder2/b.bin"
[14,] "~/folder1/folder2/a.bin" "~/folder1/folder2/c.bin"
[15,] "~/folder1/folder2/b.bin" "~/folder1/folder2/c.bin"

修改

我认为路径格式过于复杂化了问题。如果我们使用例如字母代替文件名，我们得到：

do.call(rbind,combn(letters[1:4],2,simplify=F)) [,1] [,2] [1,] "a" "b" [2,] "a" "c" [3,] "a" "d" [4,] "b" "c" [5,] "b" "d" [6,] "c" "d"

所以如你所见，没有重复。

从一列中选择两列，涵盖所有组合

1 个答案: