[R] question about sum of (column) elements in R

[Gerrit Eichner]

Hi, T. Bal,

homework? Take a look at

?tapply


  Regards  --  Gerrit


On Tue, 4 Dec 2012, T Bal wrote:

> Hi,
> I have the following data:
>
> 0   12
> 1   10
> 1   4
> 1   6
> 1   7
> 1   13
> 2   21
> 2   23
> 2   20
> 3   18
> 3   17
> 3   16
> 3   27
> 3   33
> 4   11
> 4   8
> 4   19
> 4   16
> 4   9
>
>
> In this data file I would like to sum the numbers of second column which
> belong to the same number in the first column.
> So the output would be:
>
> 0     12
> 1     40
> 2     64
>        3     111
>        etc.
>
> Thank you.
>
> Kind regards,
> T. Bal
>
> 	[[alternative HTML version deleted]]
>
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