I couldn't get your suggested method to work: `==.foo` <- function(a,b) unclass(a)==unclass(b) `>.foo` <- function(a,b) unclass(a) < unclass(b) # invert comparison is.na.foo <- function(a)is.na(unclass(a))
sort(structure(sample(5),class="foo")) #-> 1:5 -- not reversed What am I missing? -s On Thu, May 28, 2009 at 5:48 PM, Duncan Murdoch <murd...@stats.uwo.ca>wrote: > On 28/05/2009 5:34 PM, Steve Jaffe wrote: > >> Sounds simple but haven't been able to find it in docs: is it possible to >> sort a vector using a user-defined comparison function? Seems it must be, >> but "sort" doesn't seem to provide that option, nor does "order" sfaics >> > > You put a class on the vector (e.g. using class(x) <- "myvector"), then > define a conversion to numeric (e.g. xtfrm.myvector) or actual comparison > methods (you'll need ==.myvector, >.myvector, and is.na.myvector). > > Duncan Murdoch > > > ______________________________________________ > 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.