Perfect! Thanks Jim. Do you know how I could then reduce the data even further? Specifically, reducing it to 1 id per row? In this dataset, id 1 would have one row eliminated. Assume the data is much larger and cannot be deleted by visual inspection and elimination one row at a time.
Thank you, AC On Sat, Feb 20, 2010 at 6:26 PM, jim holtman <jholt...@gmail.com> wrote: > This seems to work fine (notice the missing 'c(...)'; why did you think you > needed it); > >> with(datas, aggregate(list(r = r), by = list(id = id, mod1 = >> mod1),mean)) > id mod1 r > 1 1 1 0.980 > 2 4 1 0.640 > 3 7 1 0.490 > 4 10 1 0.180 > 5 1 2 0.295 > 6 5 2 0.490 > 7 8 2 0.330 > 8 11 2 0.600 > 9 6 3 -0.040 > 10 9 3 0.580 > 11 12 3 0.210 >> > > > On Sat, Feb 20, 2010 at 6:54 PM, AC Del Re <de...@wisc.edu> wrote: >> >> Hi All, >> >> I am interested in aggregating a data frame based on 2 >> categories--mean effect size (r) for each 'id's' 'mod1'. The >> 'with' function works well when aggregating on one category (e.g., >> based on 'id' below) but doesnt work if I try 2 categories. How can >> this be accomplished? >> >> # sample data >> >> id<-c(1,1,1,rep(4:12)) >> n<-c(10,20,13,22,28,12,12,36,19,12, 15,8) >> r<-c(.98,.56,.03,.64,.49,-.04,.49,.33,.58,.18, .6,.21) >> mod1<-factor(c(1,2,2, rep(c(1,2,3),3))) >> mod2<-c(1,2,15,rep(3,9)) >> datas<-data.frame(id,n,r,mod1,mod2) >> >> # one category works perfect: >> >> with(datas, aggregate(list(r = r), by = list(id = id),mean)) >> >> id r >> 1 1 0.5233333 >> 2 4 0.6400000 >> 3 5 0.4900000 >> 4 6 -0.0400000 >> 5 7 0.4900000 >> 6 8 0.3300000 >> 7 9 0.5800000 >> 8 10 0.1800000 >> 9 11 0.6000000 >> 10 12 0.2100000 >> >> # trying with 2 categories: >> >> with(datas, aggregate(list(r = r), by = list(c(id = id, mod1 = >> mod1)),mean)) >> >> Error in FUN(X[[1L]], ...) : arguments must have same length >> >> Thank you, >> >> AC >> >> ______________________________________________ >> 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. > > > > -- > Jim Holtman > Cincinnati, OH > +1 513 646 9390 > > What is the problem that you are trying to solve? > ______________________________________________ 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.
