[GRASS-dev] Re: [GRASS-user] updating kriging modules for grass 62

[Benjamin Ducke]

I understand that R is evolving pretty quickly and that
everything, including the spatial libraries is in constant
flux.
So maybe we could make snapshots in intervals for inclusion
in GRASS?
E.g. we could take the current version 2.4 of R, add the
libraries for spatial analysis and provide some guidelines
for module authors as to what functions are stable and should
be used in GRASS-R modules.
>From time to time, we would update the base R interpreter,
all libraries and modules.
We could include such snapshots in the GRASS distribution
or package everything as an "R spatial statistics" extension
to GRASS 6.2
For the later case, I could wrap up R, the spatial libraries,
documentation and modules like v.krige into one extension
package.

Benjamin



Roger Bivand wrote:
> On Wed, 29 Nov 2006, Moritz Lennert wrote:
> 
>> On 28/11/06 09:32, Benjamin Ducke wrote:
>>> I would also expect a lot of statistical modules in the
>>> future to depend on R, seeing how powerful the R
>>> spatial analysis stuff is.
>>> There are so many useless dependencies in GRASS (Motif,
>>> BLAS, LAPACK,...), so why not add one that is actually very
>>> useful for a lot of people?
>> Are you thinking about using the Mathlib of R within GRASS C-code, or of 
>> calling R commands from within GRASS modules or scripts ?
>>
>> How easy is it to call fonctions from R libraries in non-R code ?
>>
>>> Or even better: why not include an up-to-date R shell and
>>> the best spatial stat libraries in the GRASS base
>>> distribution to make it easier for everyone to add
>>> powerful spatial statistics modules to GRASS and use them
>>> out-of-the-box?
> 
> It isn't obvious how to do this in a clean and easily maintainable way. R 
> and the associated spatial packages are quite large, and perhaps ought to 
> be installed by users themselves when needed (understood as for use 
> running the R command line within GRASS and with the interface as an R 
> package). 
> 
> On the other hand, an optional GRASS "module" might involve downloading 
> and installing R components in GRASS (under scripts, share, whatever), 
> where the R command line is not visible, and R is a compute engine behind 
> GRASS front-end(s). Now we have scripts in the Wiki, but the suggestion 
> that started this thread was to formalise them. In a medium-term future, 
> I'd see a place for the R engine being available as an *.so or *.DLL, 
> probably accessed from Python on the GRASS side through Rpy, although C 
> could also be used to pass in commands.
> 
> The maintenance aspect is important - the R engine "steps" twice a year, 
> and contributed packages - where the functionality is - can be updated 
> very frequently, sometimes with incompatibilities in function argument 
> names and types, updates triggered by bug reports and enhancement 
> requests. In making choices, getting the maintenance/update mode right 
> would be very important. 
> 
> The Lausanne LiveCD worked very nicely because of a lot of hard work done 
> by the team who put it together, including R and its packages in 
> predictable places. It can be done, but I think the alternatives need 
> thinking through. I'm a bit reserved about having GRASS depend on R, and 
> until there is more experience with shell scripts handing computation off 
> to R would prefer not to "weld down the hood/bonnet".
> 
> Best wishes,
> 
> Roger
> 
>> Well you can run an R shell within GRASS, so what exactly do you mean by 
>> including one ?
>>
>>> I think R is excellent quality code that runs on all major
>>> OS's and has no dependencies itself.
>> I agree and as we are working on a C-version of d.vect.thematic, and 
>> Roger referred me to R for potential relevant code, actually including R
>> in the dependencies might makes things easier. At this stage I just 
>> don't know enough of R internals to know what the best approach would be.
>>
>> Moritz
>>
> 

-- 
Benjamin Ducke, M.A.
Archäoinformatik
(Archaeoinformation Science)
Institut für Ur- und Frühgeschichte
(Inst. of Prehistoric and Historic Archaeology)
Christian-Albrechts-Universität zu Kiel
Johanna-Mestorf-Straße 2-6
D 24098 Kiel
Germany

Tel.: ++49 (0)431 880-3378 / -3379
Fax : ++49 (0)431 880-7300
www.uni-kiel.de/ufg