[R] Problems with aggregate
Henrique Dallazuanna
wwwhsd at gmail.com
Fri Feb 22 12:11:38 CET 2008
You can use match.fun
x
V1 V2
1 2 3.2
2 15 1.2
3 2 8.4
4 8 9.2
5 7 0.4
min <- aggregate(x, list(x[,1]), min)
min <- aggregate(x, list(x[,1]), match.fun(min))
On 21/02/2008, Mcmahon, Kevin <kwyatt.mcmahon at ttuhsc.edu> wrote:
> Hello list,
>
>
>
> I'm new to this list, so please forgive my ignorance. I have searched
> R-help for some hints into what might be my problem, but I truly have no
> idea where to go from here.
>
>
>
> I have an object of approximately 15,000 rows and 2 columns. There are
> many duplicates in the first column, all with different corresponding
> values in the second column. For example (2 is duplicated):
>
> 2 3.2
>
> 15 1.2
>
> 2 8.4
>
> 8 9.2
>
> 7 0.4
>
>
>
> I used the following code to aggregate these based on the first column
> and get the min and max:
>
> min<-aggregate(as.numeric(humanneph[,2]),
> list(as.numeric(humanneph[,1])), min)
>
> max<-aggregate(as.numeric(humanneph[,2]),
> list(as.numeric(humanneph[,1])), max)
>
>
>
> Both worked beautifully!
>
>
>
> THEN, I accidentally overwrote the object min. Since I hadn't touched
> the object humanneph, I copied the above code from my saved history and
> re-ran it. I get the following error:
>
> Error in FUN(X[[1L]], ...) : argument "INDEX" is missing, with no
> default
>
>
>
> So, I went back and again, copying directly from my saved history,
> re-made my object humanneph, and re-ran the above code again. Still the
> same problem!!!
>
>
>
> So, it seems that after running this code once, suddenly aggregate does
> not work!!!
>
>
>
> Can anyone help me?
>
>
>
> My sessionInfo()
>
> R version 2.5.1 (2007-06-27)
>
> i386-pc-mingw32
>
>
>
> attached base packages:
>
> [1] "stats" "graphics" "grDevices" "utils" "datasets"
> "methods"
>
> [7] "base"
>
>
>
> Thanks!
>
> Wyatt
>
>
>
> K. Wyatt McMahon, Ph.D.
>
> Postdoctoral Research Associate
>
> Department of Internal Medicine
>
> Texas Tech University Health Sciences Center
>
> Lubbock, TX
>
> 79430
>
> (806)743-4072
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O
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