From Phil.Lee at morganstanley.com  Wed Sep 17 22:22:19 2008
From: Phil.Lee at morganstanley.com (Lee, Philip (IT))
Date: Wed, 17 Sep 2008 16:22:19 -0400
Subject: [Rd] Dates in C api
In-Reply-To: <e8e755250809171319h15fc8461yfd5c7ab1531ad89e@mail.gmail.com>
References: <575EAD86322DA342B50FE422364A9F52082D528B@NYWEXMB27.msad.ms.com>
	<e8e755250809171319h15fc8461yfd5c7ab1531ad89e@mail.gmail.com>
Message-ID: <575EAD86322DA342B50FE422364A9F52082D531D@NYWEXMB27.msad.ms.com>

Thanks, everyone, for the responses.  That's exactly what I was after.

Regards,
Phil 

> -----Original Message-----
> From: Jeff Ryan [mailto:jeff.a.ryan at gmail.com] 
> Sent: Wednesday, September 17, 2008 4:19 PM
> To: Lee, Philip (IT)
> Cc: r-devel at r-project.org
> Subject: Re: [Rd] Dates in C api
> 
> If you are looking for examples of handling dates/times (specifically
> POSIXct) within C code, the dev branch of xts has quite a bit 
> of code now.
> 
> http://r-forge.r-project.org/plugins/scmsvn/viewcvs.php/dev/pk
g/src/?root=xts
> 
> Assigning the class (or any attribute) within the C code will 
> be much faster than doing it outside of C, at least in my 
> experience with larger data.
> 
> setAttrib(ans, R_ClassSymbol, mkString("Date"))
> 
> HTH
> Jeff
> 
> On Wed, Sep 17, 2008 at 12:24 PM, Lee, Philip (IT) 
> <Phil.Lee at morganstanley.com> wrote:
> > r-devel,
> >
> > I've been trying to write a C plugin for R, and I'm struggling to 
> > understand how dates are represented.
> >
> > I can create a date in R:
> >> mydate<-as.Date(1, origin="1900-01-01") mydate
> > [1] "1900-01-02"
> >
> > When I pass my date to a plugin, though, it's type is that 
> of a real.
> > There doesn't seem to be a date type in Rinternals.h, is 
> there a way 
> > to recognize that a value is a date rather than a real?
> >
> > Equally, does anyone know if it's possible to create date values in 
> > the C api?
> >
> > Thanks,
> > Phil Lee
> >
> > Philip Lee
> > Morgan Stanley | Technology
> > 750 Seventh Avenue, 12th Floor | New York, NY  10019 
> > Phil.Lee at morganstanley.com
> > --------------------------------------------------------
> >
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> > ______________________________________________
> > R-devel at r-project.org mailing list
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> >
> 
> 
> 
> --
> Jeffrey Ryan
> jeffrey.ryan at insightalgo.com
> 
> ia: insight algorithmics
> www.insightalgo.com
>
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[Rd] Dates in C api
Lee, Philip (IT