[R] Problems with aggregate

[Mcmahon, Kevin]

Thank you so much, Martin and Henrique!  I followed Martin's advice and everything worked great!  I'm sure Henrique's advice will also prove helpful, because it often asked for a 'FUN' that was missing, which I'm sure is match.fun(min). Anyway, I'm just glad it worked!  Thanks so much!

K. Wyatt McMahon, Ph.D.
Postdoctoral Research Associate
Department of Internal Medicine
Texas Tech University Health Sciences Center
Lubbock, TX
79430
(806)743-4072

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On Behalf Of Martin Elff
> Sent: Friday, February 22, 2008 3:52 AM
> To: r-help at r-project.org
> Subject: Re: [R] Problems with aggregate
> 
> I guess it will save you some trouble to give the
> results of 'aggregate' some other name than
> 'min' or 'max', as in
> 
> min.humanneph <- aggregate(as.numeric(humanneph[,2]),
> 	list(as.numeric(humanneph[,1])), min)
> 
> max.humanneph <- aggregate(as.numeric(humanneph[,2]),
> 	list(as.numeric(humanneph[,1])), max)
> 
> HTH,
> Martin
> 
> On Thursday 21 February 2008 (22:47:53), Mcmahon, Kevin wrote:
> > 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?
> >
> >
> 
> 
> 
> --
> 10.0 times 0.1 is hardly ever 1.0
>  ---- Kernighan and Plauger
> 
> -------------------------------------------------
> Dr. Martin Elff
> Faculty of Social Sciences
> LSPWIVS (van Deth)
> University of Mannheim
> A5, 6
> 68131 Mannheim
> Germany
> 
> Phone: +49-621-181-2093
> Fax: +49-621-181-2099
> E-Mail: elff at sowi.uni-mannheim.de
> Web: http://webrum.uni-mannheim.de/sowi/elff/
>      http://www.sowi.uni-mannheim.de/lspwivs/
> -------------------------------------------------
> 
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