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]]

-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/