[R] Problems with aggregate

[Martin Elff]

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/
-------------------------------------------------