Oh wow, that would be it. Not sure how I missed that. Thanks for the tip. Sent from my iPhone
On Jan 11, 2011, at 18:56, "David Winsemius" <dwinsem...@comcast.net> wrote: > > On Jan 11, 2011, at 5:41 PM, Dickison, Daniel wrote: > >> The documentation for `aggregate` makes it sound like >> aggregate.formula should behave identically to aggregate.data.frame >> (apart from the way the parameters are passed). But it looks like >> aggregate.formula is quietly removing rows where any of the "output" >> variables (those on the LHS of the formula) are NA. This differs >> from how aggregate.data.frame works. Is this expected behavior? >> >> Here are a couple of examples: >> >>> d <- data.frame(a=rep(1:2, each=2), >> + b=c(1,2,NA,3)) >>> aggregate(d["b"], d["a"], mean) >> a b >> 1 1 1.5 >> 2 2 NA >>> aggregate(b ~ a, d, mean) >> a b >> 1 1 1.5 >> 2 2 3.0 >> >> It's removing whole rows even if just one of the columns is NA, i.e.: >> >>> d <- data.frame(a=rep(1:2, each=2), >> + b=c(1,2,NA,3), >> + c=c(NA,2,3,NA)) >>> aggregate(cbind(b,c) ~ a, d, mean) >> a b c >> 1 1 2 2 >> > > The help page for aggregate gives the calling defaults for > aggregate.formula as: > ## S3 method for class 'formula' aggregate(formula, data, FUN, ..., > subset, na.action = na.omit) > So the description you give seems to be adhering to what I would have > expected (had I initially read the help page.) > -- > David Winsemius, MD > West Hartford, CT > ______________________________________________ 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.
