[STATSGRASS] Re: [GRASS-user] Simulation in grass 6

[Rainer M. Krug]

Agustin Lobo wrote:
> Actually, I often use R as an scripting language
> for grass. The problem is that grass commands have
> to be issued using system(), which, for a complex code,
> becomes inconvenient (lots of paste() for generating the
> actual grass command).

This is indeed a hassle, but I wrote a small R function which is pasting 
all the parameters supplied together and executing them via system() - 
still not perfect, but it works nicer then the system(paste(...)) approach.

> Not being an expert at all on python, I wonder
> if making R able of executing grass commands without
> having to use system() could not be a valid alternative
> to python, at least in some cases.

I think this would, at least, make using grass from R much easier. And 
it shouldn't be to dificult to do that - just defining a function with 
the same name as in R and execute it via system() - I think about using 
this in my simulation.


Thanks,

Rainer

> 
> Anyway, I think that the real solution would be having a GIS
> able of displaying R objects, sort of RGis.
> 
> Agus
> 
> Hamish escribió:
>> Rainer M. Krug wrote:
>>
>>> I am planning to write a spatial simulation model, simulating the 
>>> spread of alien species on a landscape scale by using grass.
>>> My question how I should write the simulation model, i.e. in which 
>>> scripting language. I am using Linux and have quite a bit of 
>>> experience with R, so I thought that R (together with spgrass6) would 
>>> be a nice scripting language to write the simulation and sending the 
>>> grass commands through to grass, because it offers me quite a bit 
>>> more concerning strtucturing on the modelling side then using a 
>>> normal shell script
>>> But the simulation should also run under Windows and I don't have any 
>>> experience with grass and R under windows.
>>
>> It sounds very well suited for Linux or MacOSX, but I've little idea 
>> about the
>> GRASS+R Windows situation. Maybe someone on the statsgrass mailing 
>> list knows?
>> (taking the liberty to cc)
>>
>>> I have the following questions:
>> ..
>>> 3) Is any other scripting language more suitable for what I want to 
>>> achieve (I have no experience with C / C++, but quite a bit with 
>>> Delphi. I have never used the likes of perl et al. and bash scrips 
>>> seem a bit awkward to me for bigger projects.)?
>>
>> You could try python. The next version of GRASS will use python 
>> heavily for the
>> GUI, so expect lots of example scripts, help on the mailing list from 
>> fellow
>> travelers, and tight integration with the code.
>>
>> Learn python in 10 min:  http://www.poromenos.org/tutorials/python
>>
>> Also there is a SWIG/Python interface to any needed GIS library 
>> functions,
>> which is pretty cool, although the grass modules generally give you 
>> what you
>> need without having to resort to using any low-level libgis functions.
>>
>> see  http://grass.gdf-hannover.de/wiki/GRASS_and_Python
>>      http://freegis.org/cgi-bin/viewcvs.cgi/grass6/swig/python/
>>
>> Hamish
>>
>>
>>
>>       
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> 


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Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation
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Plant Conservation Unit
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