R
!!!行列
{{outline}}
----
!!行列の作成 matrix()
matrix(データ, nrow=行数, ncol=列数)
{{pre
> matrix(1:6, nrow=2, ncol=3)
     [,1] [,2] [,3]
[1,]    1    3    5
[2,]    2    4    6
> matrix(1:6, nrow=3, ncol=2)
     [,1] [,2]
[1,]    1    4
[2,]    2    5
[3,]    3    6
}}

!!見出しをつける colnames(), rownames()
 colnames(data) <- c("koku", "suu", "eigo")

!!要素の指定 [行番号, 列番号]
{{pre
> mx <- matrix(1:6, nrow=3, ncol=2)
> mx
     [,1] [,2]
[1,]    1    4
[2,]    2    5
[3,]    3    6
> mx[3, 1]
[1] 3
> mx[2, 2]
[1] 5

}}
!!行列の演算