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1198075
matrix() データを行列に並べる
matrix(並べるデータのベクトル,一列にいくつずつ並べるか)
> matrix(c(1,2,3,4,5,6), 2)
[,1] [,2] [,3]
[1,] 1 3 5
[2,] 2 4 6
> matrix(1:20, 2)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 3 5 7 9 11 13 15 17 19
[2,] 2 4 6 8 10 12 14 16 18 20
> matrix(rnorm(10), 2)
[,1] [,2] [,3] [,4] [,5]
[1,] 0.5144311 0.2239666 0.2956844 2.289213 -0.2167226
[2,] 0.2708774 1.0643932 -0.4709602 1.029646 0.4163721
>
- データの数と、一列にならべていって行数の分、データがぴったりないとエラーになる
> matrix(1:20, 10)
[,1] [,2]
[1,] 1 11
[2,] 2 12
[3,] 3 13
[4,] 4 14
[5,] 5 15
[6,] 6 16
[7,] 7 17
[8,] 8 18
[9,] 9 19
[10,] 10 20
> matrix(1:20, 2)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 3 5 7 9 11 13 15 17 19
[2,] 2 4 6 8 10 12 14 16 18 20
> matrix(1:20, 3)
[,1] [,2] [,3] [,4] [,5] [,6] [,7]
[1,] 1 4 7 10 13 16 19
[2,] 2 5 8 11 14 17 20
[3,] 3 6 9 12 15 18 1
警告メッセージ:
matrix(1:20, 3) で:
データ長 [20] が行数 [3] を整数で割った、もしくは掛けた値ではありません
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https://sugiura-ken.org/wiki/