[R] help with Date class

Dirk Eddelbuettel edd at debian.org
Wed Jul 7 17:01:32 CEST 2010

On Wed, Jul 07, 2010 at 01:25:43PM +0200, 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

w <- Sys.Date()   # does the same, but in one step

> w$year #Doesn't work
> w["year"] #is NA
> I would like to know the correct way to acces to this value.

wp <- as.POSIXlt(w)    # POSIXlt has the components
unclass(wp)            # shows you all components
wp$year + 1900         # stored as year - 1900, see Unix manuals
wp$mon + 1             # stores as mon -1, see Unix manuals

Arguably, extractor functions would be of help here.

  Regards, Dirk

More information about the R-help mailing list