From murdoch at stats.uwo.ca  Sat Jul 15 03:02:27 2006
From: murdoch at stats.uwo.ca (Duncan Murdoch)
Date: Fri, 14 Jul 2006 21:02:27 -0400
Subject: [Rd] chron vs. POSIX
In-Reply-To: <87psg8rn75.fsf@arctocephalus.homelinux.org>
References: <87psg8rn75.fsf@arctocephalus.homelinux.org>
Message-ID: <44B83EA3.7020700@stats.uwo.ca>

On 7/14/2006 3:38 PM, Sebastian Luque wrote:
> Hi,
> 
> One of the big decisions when writing code is how to handle dates and
> times.  Gabor Grothendieck provided an excellent overview of the issue in
> his R News 4/1 (2004) article, and many users and developers are probably
> using it as a guide.  The proposed guideline is to use the simplest class
> required; as Gabor put it "use Date if possible, otherwise use chron, and
> otherwise use POSIX".
> 
> This seems to me a very efficient strategy, judging from my own
> experiences and those of others users.  All but the simplest calculations
> with POSIX objects demand great care, due to time zone and and daylight
> savings considerations.  Therefore, I've always chosen chron for
> relatively complex projects, where I don't need to deal with time zones or
> daylight savings problems.  The ease with which objects can be switched
> from numeric to chron representations is a major advantage IMHO?.
> 
> If Gabor's recommendations are to be followed, wouldn't it make sense to
> include chron in base R?  Given that flexibility for handling time
> variables is so fundamental, the addition of chron to base R would provide
> users everything they need to work with time, without the need to rely on
> an external package.  What do others think?

Putting something into base R essentially means that it is to be taken 
over by R core.  I think chron is being adequately maintained now (the R 
maintainer is already a member of R core), so I don't see a need for that.

I don't see a problem having a package on CRAN.  If it's a good package 
and people realize that it's good, and it remains available for others 
to use, then what problem is being solved?

Duncan Murdoch



[Rd] chron vs. POSIX
Duncan Murdoch