[STATSGRASS] problem with kriging not solved but new qestions arise

[Roger Bivand]

On Fri, 1 Sep 2006, Jarek Jasiewicz wrote:

> Jarek Jasiewicz napisa³(a):
> > I try to krige some data, I do following grass wiki tutorial (that 
> > with gaiciture)
> >
> /cut
> 
> 
> Jarek Jasiewicz napisa³(a):
> > I try to krige some data, I do following grass wiki tutorial (that 
> > with gaiciture)
> /cut
> 
> 
>  > And I recive the error:
> 
>  > Error in predict.gstat(g, newdata = newdata, block = block, nsim = 
> nsim,  :
>  >  data items in gstat object and newdata have different coordinate
>  > reference systems
> 
> 
> After 20 hours of fighting with R I partially solved that problem 
> removing projection information (proj4) from both spatial data frames (I 
> set roj4string:Formal class 'CRS' [package "sp"] with 1 slots
>   .. .. ..@ projargs: chr NA)
> 
> And all works well
> 
> so - projection information (EPSG 2173 - Polish, 1965 zone IV) makes 
> problem?
>  why?
> or eny projection makes problem - in fact, tutorial data has no proj4 
> information

This has just bitten me too!

predict.gstat() tries to be fussy and check that the projections are 
equal, but they are not always represented the same way even though they 
are the same. In my case for Meuse bank I had:

> proj4string(BMcD_grid)
[1] "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +no_defs +a=6377397.155 
+rf=299.1528128 +towgs84=565.036,49.914,465.839,-0.4094,0.3597,-1.86854,-4.0772"
> proj4string(BMcD)
[1] "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +ellps=bessel +units=m +no_defs"

So I simply assigned from one to the other to have the same 
representation before calling gstat():

> proj4string(BMcD) <- CRS(proj4string(BMcD_grid))

I hope the same will work for you.

Roger

> 
> mayby sombody know???
>  regards
> Jarek
> 
> _______________________________________________
> statsgrass mailing list
> statsgrass at grass.itc.it
> http://grass.itc.it/mailman/listinfo/statsgrass
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no