[R] extracting the last row of each group in a data frame

[Gabor Grothendieck]

Try this:

> aggregate(DF[-1], DF[1], tail, 1)
  Name Value
1    A     3
2    B     8
3    C     2
4    D     3


On Mon, Nov 16, 2009 at 2:42 PM, Hao Cen <hcen at andrew.cmu.edu> wrote:
> Hi,
>
> I would like to extract the last row of each group in a data frame.
>
> The data frame is as follows
>
> Name Value
> A 1
> A 2
> A 3
> B 4
> B 8
> C 2
> D 3
>
> I would like to get a data frame as
> Name Value
> A 3
> B 8
> C 2
> D 3
>
> Thank you for your suggestions in advance
>
> Jeff
>
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