!!!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) {{pre > 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 {{pre > 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 > }}