Hi,
aggregate() does not preserve the order of levels for
ordered factors, e.g.,
levs <- c("Low", "Med", "Hi")
d <- data.frame(x = 1:30, fac = ordered(rep(levs, 10), levels = levs))
out <- aggregate(d[,"x"], by = list(fac=d$f), FUN = mean)
cat("Original ordered levels:", levels(d$fac), "\n")
cat("Levels in aggregated output:", levels(out$fac),
"\n")
Perhaps this is unintended? If intended, a note in its documentation
could be helpful to alert users.
> δΎ“ version
_
platform i686-pc-linux-gnu
arch i686
os linux-gnu
system i686, linux-gnu
status beta
major 2
minor 2.1
year 2005
month 12
day 18
svn rev 36792
language R
--
David