[R] simple matrix question

[Paul Lemmens]

Hoi Christoph,

--On woensdag 4 juni 2003 15:21 +0200 Christoph Lehmann 
<lehmann at puk.unibe.ch> wrote:

> what is the easiest way to get from
> x
>      x1 x2
> [1,]  2  3
> [2,]  3  2
> [3,]  1  3
> [4,]  1  4
>
> xbar1
>        x1 x2
> [1,] 1.75  3
> [2,] 1.75  3
> [3,] 1.75  3
> [4,] 1.75  3
>
> with the mean of the columns of x as values?
>
xbar1 <- tapply(as.vector(x), gl(2,4), mean);



-- 
Paul Lemmens
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