[R] "unique" rows in data frame

[jim holtman]

Here is one way to get the means:

> x
  x1 x2
1  A  1
2  B  2
3  B  3
> aggregate(x$x2, list(x$x1),mean)
  Group.1   x
1       A 1.0
2       B 2.5
>


On 10/2/07, Dieter Best <dieterbest_2000 at yahoo.com> wrote:
> Hello there,
>
>  I have a data frame a small version of which could look like the following:
>
>    x1 x2
> 1  A  1
> 2  B  2
> 3  B  3
>
>  Now I need to remove rows which are duplicate in x1, i.e. in the example above I would remove row 3.
>
>  I have an ugly solution with for and while loops and ifs. ... And of course my data set is much larger and my solution takes along time.
>
>  Any ideas what could be the best way to do this in R?
>
>  Better yet: I actually would like to sort of collapse row 2 and 3 in the example above by replacing 2 and 3 with a new row 2 which has in x2 the mean of old x2 of row 2 and 3 (maybe this is poorly said).
>
>  Anyways, thanks a lot in advance for suggestions.
>
>  -- D
>
>
>
> ---------------------------------
>
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-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?