On Tue, Oct 26, 2010 at 11:55 AM, Dennis Murphy <djmu...@gmail.com> wrote: > Hi: > > When it comes to split, apply, combine, think plyr. > > library(plyr) > ldply(split(afvtprelvefs, afvtprelvefs$basestudy), > function(x) coef(lm (ef ~ quartile, data=x, weights=1/ef_std)))
Or do it in two steps: models <- dlply(aftvprelvef, "basestudy", function(x) lm(ef ~ quartile, data=x, weights=1/ef_std) coefs <- ldply(models, coefs) That way you can easily pull out other info rsq <- function(x) summary(x)$r.squared ldply(models, rsq) Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ 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.
