The function for getting the year from date is there in package lubridate (as well as many other convenient functions to work with dates).
More generally, finding "all" methods for a given class may be a little tricky. If "all" means everything you have installed and currently attached to your search path then methods(class="Date") will do it (for S3 classes). (but "The functions listed are those which _are named like methods_ and may not actually be methods (known exceptions are discarded in the code). ") The result depends on which packages you have loaded: in my currently open R session, methods("Date") lists 36 "possible methods" but after library(zoo) I get two more ( "as.yearmon.Date" and "as.yearqtr.Date"). Regards, Kenn On Fri, Apr 29, 2011 at 9:05 AM, Russ Abbott <russ.abb...@gmail.com> wrote: > Hi, > > I'm still confused about how to find out what methods are defined for a > given class. For example, I know that > >> today <- Sys.Date() > > will produce an object of type Date. But I'm not sure what I can do with > Date objects or how I can find out. > >> ?Date > > > refers me to the Date documentation page. But it doesn't tell me how, for > example, to extract the current year from a date object. > > I tried > >> year(today)Error: could not find function "year" > > > Is there some other function that does the job? I want a function f such > that > f(today) will return 2011. Perhaps there is no such function. > But in general I don't have any confidence that I would know how to find it > if it existed or that I would know how to assure myself that there was no > such function. > > Thanks. > > *-- Russ * > > [[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. > ______________________________________________ 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.