Here is one solution for your question: mean.data <- with(DF, tapply(data, years, mean, na.rm = T)) mean.data2 <- with(DF, tapply(data2, years, mean, na.rm = T)) cbind(mean.data , mean.data2)
Another one would be for you to read about the package plyr (which is better for this job, actually) And regarding the years being recoded, look at either: ?cut or ?recode (from the car package) Best, Tal ----------------Contact Details:------------------------------------------------------- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) ---------------------------------------------------------------------------------------------- On Sun, Apr 25, 2010 at 9:29 AM, steven mosher <mosherste...@gmail.com>wrote: > I have a 43MB dataframe ( 5 variables) and I'm trying to summarize subsets > of the data. > I've RTFM ( not very clear) and looked at a variety of samples but cant > seem > to figure out > how to make these functions work. > > A sample of what I want to do would be this: > > ids<-seq(1,50) > years<-c(rep(5,10),rep(6,10),rep(7,10),rep(8,20)) > data<-c(rep(23.2,7),rep(14.2,17),rep(29.2,6),rep(13.4,10),rep(16.3,5), NA, > rep(40,4)) > data2<-c(rep(22.2,5),rep(13.2,8),NA, rep(29.8,16),rep(12.4,10),rep(16.3,5), > rep(38,5)) > DF<-data.frame(ids,years,data,data2) > > That will give you a dataframe that is a good analog of what I have. i > would like to calculate means > ( with NA removed na.rm) for each level of years. > > data data2 > 5 xx. yy. > 6 xx yz > 7 ... ,,, > 8 .. ... > > And then things like this: > > 5-7 : xx yy > 8 : xy zz > > [[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. > [[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.
