[R] help with Date class

[David Winsemius]

On Jul 7, 2010, at 7:25 AM, Elisenda Vila wrote:

> I am trying to work with the Date class which is written in S3 and I  
> would
> like to access to the elements of the class (for example the year).  
> I've
> tryed to do it for example like this:
>
> as.Date(Sys.time)->w

Throws an error  ... since Sys.time is a function

> w$year #Doesn't work

Why should it? Dates are not stored as lists.

?Date

> w["year"] #is NA
>
> I would like to know the correct way to acces to this value.

as.Date(Sys.time)->w
Error in as.Date.default(Sys.time) :
   do not know how to convert 'Sys.time' to class "Date"
 > as.Date(Sys.time())->w
 > w
[1] "2010-07-07"
 > format(w, "%Y")
[1] "2010"

-- 
David Winsemius, MD
West Hartford, CT