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: [EMAIL PROTECTED] Web: http://webrum.uni-mannheim.de/sowi/elff/ http://www.sowi.uni-mannheim.de/lspwivs/ ------------------------------------------------- ______________________________________________ R-help@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.