From ggrothendieck at gmail.com  Sat Jul 15 19:37:23 2006
From: ggrothendieck at gmail.com (Gabor Grothendieck)
Date: Sat, 15 Jul 2006 13:37:23 -0400
Subject: [Rd] chron vs. POSIX
In-Reply-To: <44B9225C.8000307@stats.uwo.ca>
References: <87psg8rn75.fsf@arctocephalus.homelinux.org>
	<44B83EA3.7020700@stats.uwo.ca>
	<971536df0607151001l536b65c8t6ad40393fd3e35f3@mail.gmail.com>
	<44B9225C.8000307@stats.uwo.ca>
Message-ID: <971536df0607151037q3ad8d114vb6e050ac8bb6d032@mail.gmail.com>

On 7/15/06, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:
> On 7/15/2006 1:01 PM, Gabor Grothendieck wrote:
> > On 7/14/06, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:
> >> 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?
> >
> > I think the problem is that there is nothing to signal its importance.  Perhaps
> > chron should be added to the "recommended" package list.
>
> I think that would be preferable to making it a base package, but it's
> not the only way to publicize it.  Why not add something to the  Wiki to
> compare the various possibilities for storing dates and times?

As a recommended package it would be included in all binary releases
ensuring access without a separate install and would provide more
official endorsement.



[Rd] chron vs. POSIX
Gabor Grothendieck