George Aldridge wrote: > > I am new to R and trying to aggregate a character variable. I have > searched, and tapply() seems to hold the best hope, but I am having > trouble with it. I have a character variable 'hab' and 3 factors all of > the same length: > >> length(hab) > [1] 105219 >> length(sp) > [1] 105219 >> length(pl) > [1] 105219 >> length(yr) > [1] 105219 > > However, when I try to aggregate the character variable by the 3 factors, > I get an error: > >> habs <- tapply(hab, c(sp,pl,yr)) > Error in tapply(hab, c(sp, pl, yr)) : arguments must have same length > > Is there any way to aggregate a character variable? > > Not sure what you want to do. Can you show us with a small made-up example, or a small subset of your data? Normally the format of tapply() is tapply(variable_to_aggregate,list(factor_1,factor_2,factor_3,...),aggregating_function) [list() rather than c() is definitely the correct way to specify the list of factors by which to aggregate!] Do you just want to tabulate the habitat types by the other three factors? table(hab,sp,pl,yr) ... -- View this message in context: http://www.nabble.com/length-error-using-tapply%28%29-tp25917650p25935019.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
