[R] matching identical row names

[Gabor Grothendieck]

aggregate(DF[,-1], DF[, 1, drop = FALSE], mean)

On 4/15/06, Srinivas Iyyer <srini_iyyer_bio at yahoo.com> wrote:
> dear group,
>
> i have a sample matrix
> name   v1   v2   v3   v4
> cat   10    11   12   15
> dog   3     12   10   14
> cat   9     12   12   15
> cat   5     12   10   11
> dog   12    113  123  31
> ...
>
>
> since cat is repeated 3 times, I want a mean value for
> it. Like wise for every element of the name column.
> cat v1 = mean(c(10,9,5))
> cat v3 = mean(c(11,12,13))
> ..etc.
>
> name v1   v2     v3   v4
> cat  8   11.6   11.3  13.6
> dog  7.5 62.5   66.5  22.5
>
> could any one help me in solving this mystery. thank you.
>
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