- 追加された行はこの色です。
- 削除された行はこの色です。
- 行列演算 へ行く。
[[統計学]]
**行列演算 by R
[[http://www.digistats.net/image/2008/08/stat.gif>http://www.digistats.net/z/index.php?%C5%FD%B7%D7%B3%D8]] [[http://www.digistats.net/image/2008/08/r.gif>http://www.digistats.net/z/index.php?%C5%FD%B7%D7%B3%D8]]
**行列演算
***行列の作成
> M=matrix(c(2,3,5,1,2,3,5,3,4),nrow=3,ncol=3)
> M
[,1] [,2] [,3]
[1,] 2 1 5
[2,] 3 2 3
[3,] 5 3 4
> (N=matrix(1:6,nrow=3,ncol=2))
[,1] [,2]
[1,] 1 4
[2,] 2 5
[3,] 3 6
***行列の積
> M%*%N
[,1] [,2]
[1,] 19 43
[2,] 16 40
[3,] 23 59
***行列の固有値
> eigen(M)
$values
[1] 9.7085895 -1.9228572 0.2142678
$vectors
[,1] [,2] [,3]
[1,] -0.5207997 -0.7920917 0.52368032
[2,] -0.4779605 0.1540594 -0.85175154
[3,] -0.7073341 0.5906407 -0.01668026
***逆行列
> solve(M)
[,1] [,2] [,3]
[1,] 0.25 -2.75 1.75
[2,] -0.75 4.25 -2.25
[3,] 0.25 0.25 -0.25
***単位行列
> solve(M)%*%(M)
[,1] [,2] [,3]
[1,] 1.000000e+00 -4.440892e-16 -8.881784e-16
[2,] 4.440892e-16 1.000000e+00 1.776357e-15
[3,] 0.000000e+00 1.110223e-16 1.000000e+00