[GRASSLIST:9955] Re: R, kriging and grass6

[Thomas Adams]

Roger,

I think your suggestion would be very beneficial — in general for many 
GRASS & R uses such 'cookbook' examples would be greatly helpful.

Tom


Roger Bivand wrote:

>On Mon, 23 Jan 2006, ivan marchesini wrote:
>
>  
>
>>Hi to all...
>>we are triyng to use kriging using R and grass6,
>>We have seen a lot of documentation about R and GRASS5 but not so many
>>about grass6...
>>the problem is that we are trying to do an interpolation using the
>>functions gmeta6 and kriging...
>>if we are not wrong, the R library GRASS is developed for grass5 and
>>inside there is the function krige.G that use the location data acquired
>>using the gmeta() function...
>>the problem is that we have found the gmeta6() function but not the
>>krige.G6 function and obvously the krige.G doesn't work using the
>>location data of grass6 (obtained using gmeta6)  
>>
>>how can we simply solve this problem....
>>    
>>
>
>krige.G was a nasty hack, and should best be forgotten. The direct route 
>is to use the sp classes in R and implemented for GRASS in spgrass6 - see 
>GRASS News for the GRASS side and R News for the R side, combined with a 
>proper R geostats package. Of those available, gstat is tightly bound to 
>sp classes, so as far as I know, the only bit that needs doing by hand is 
>to create a GridTopology object, or a SpatialGrid object, from the data 
>returned by gmeta6() to pass to the kriging prediction function.
>
>If you like, we can iterate to a working example from passing the vector 
>points to R from GRASS, doing the modelling and kriging predictions, and 
>passing the prediction rasters back to GRASS, but I'd like input from 
>users to make the description sound.
>
>Best wishes,
>
>Roger
>
>  
>
>>thank you
>>
>>Ivan
>>
>>
>>
>>
>>    
>>
>
>  
>


-- 
Thomas E Adams
National Weather Service
Ohio River Forecast Center
1901 South State Route 134
Wilmington, OH 45177

EMAIL:	thomas.adams at noaa.gov

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