Still confused about classes
Hi Russ,
One tool that might help could be ?methods and ?showMethods
For example:
## for S3
methods(class = "Date")
## for S4
showMethods(classes = "Date")
regarding getting the actual year, I would use (though there may be
better ways):
format.Date(as.Date("2010-01-01"), format = "%Y")
HTH,
Josh
On Thu, Apr 28, 2011 at 11:05 PM, 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]]
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Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/