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@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.