Still confused about classes
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.abbott at 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 at 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.