如何从R中的向量创建对的组合？
要创建对的组合，我们可以使用combn函数。此函数将有助于使用向量长度和代表一对的值2来创建组合。虽然，这已经足够了，但我们可以转置输出以获得更好看的输出。
示例1
x1<−rpois(6,5) x1输出结果
[1] 5 3 7 4 8 2
为x1的值创建对组合-
示例
t(combn(x1,2))输出结果
[,1] [,2] [1,] 5 3 [2,] 5 7 [3,] 5 4 [4,] 5 8 [5,] 5 2 [6,] 3 7 [7,] 3 4 [8,] 3 8 [9,] 3 2 [10,] 7 4 [11,] 7 8 [12,] 7 2 [13,] 4 8 [14,] 4 2 [15,] 8 2
例2
x2<−LETTERS[1:5]
为x2的值创建对组合-
示例
t(combn(x2,2))输出结果
[,1] [,2] [1,] "A" "B" [2,] "A" "C" [3,] "A" "D" [4,] "A" "E" [5,] "B" "C" [6,] "B" "D" [7,] "B" "E" [8,] "C" "D" [9,] "C" "E" [10,] "D" "E"
例3
x3<−c("F1","F2","F3","F4","F5","F6")为x3的值创建对组合-
示例
t(combn(x3,2))输出结果
[,1] [,2] [1,] "F1" "F2" [2,] "F1" "F3" [3,] "F1" "F4" [4,] "F1" "F5" [5,] "F1" "F6" [6,] "F2" "F3" [7,] "F2" "F4" [8,] "F2" "F5" [9,] "F2" "F6" [10,] "F3" "F4" [11,] "F3" "F5" [12,] "F3" "F6" [13,] "F4" "F5" [14,] "F4" "F6" [15,] "F5" "F6"
例4
x4<−sample(0:9,5) x4输出结果
[1] 5 6 2 7 4
为x4的值创建对组合-
示例
t(combn(x4,2))输出结果
[,1] [,2] [1,] 5 6 [2,] 5 2 [3,] 5 7 [4,] 5 4 [5,] 6 2 [6,] 6 7 [7,] 6 4 [8,] 2 7 [9,] 2 4 [10,] 7 4
例5
x5<−round(rnorm(5),0) x5输出结果
[1] 0 1 −1 1 0
为x5的值创建对组合-
示例
t(combn(x5,2))输出结果
[,1] [,2] [1,] 0 1 [2,] 0 −1 [3,] 0 1 [4,] 0 0 [5,] 1 −1 [6,] 1 1 [7,] 1 0 [8,] −1 1 [9,] −1 0 [10,] 1 0