[Rd] external pointers

Byron Ellis ellis at stat.harvard.edu
Mon Dec 12 22:20:45 CET 2005


There's also Luke's own site, in particular http://www.stat.uiowa.edu/ 
~luke/R/weakfinex.html

On Dec 12, 2005, at 12:16 AM, Prof Brian Ripley wrote:

> On Mon, 12 Dec 2005, Roger Bivand wrote:
>
>>> Where would be best to read about externalptr? I'm having trouble
>>> finding material in the manuals or the site-search.
>>>
>>> And would I need to use all the .Call machinery and C headers and  
>>> SEXP
>>> etc in order to handle externalptr objects?
>>
>> One package using externalptr is rgdal - Tim Keitt wrote the  
>> bindings to
>> the external GDAL library for reading raster images to first return a
>> pointer to a dataset (on disk) opened by GDAL, then to use the  
>> object to
>> retrieve (parts of) the data. Most of the .Call/SEXP machinery is  
>> there
>> (for the C++ case, GDAL is C++, so GDAL manages its own memory for  
>> its
>> objects). The package also uses S4 classes, which may be overkill  
>> for your
>> purposes.
>
> RODBC is another, somewhat simpler, one.
>
> There is documentation on developer.r-project.org, but my  
> recollection is
> that is was not up to date (and in particular not re finalizers).   
> On my
> TODO list is to add end-user documentation to `Writing R Extensions'.
>
> -- 
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self)
> 1 South Parks Road,                     +44 1865 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

---
Byron Ellis (ellis at stat.harvard.edu)
"Oook" -- The Librarian



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