[R-sig-Geo] dumping interpolated results into grass6...

[A Horacio Samaniego]

I wonder if there are any Xtra trick to dump a SpatialPixelDataFrame into 
grass6? I get the following error. (I seem to have rgdal up and running.)

> writeRast6sp(kk,"idw_hs",zcol="var1.pred",NODATA=-9999.99)
Error in writeRast6sp(kk, "idw_hs", zcol = "var1.pred", NODATA = -9999.99)
:
         only numeric columns may be exported


I have read the vignettes and 
http://grass.gdf-hannover.de/twiki/bin/view/GRASS/GrassSixTutorial#Mini_How_to_interpolate_using_kr 
carefully... And I'm not sure where ( and if?) I'm doing this wrong...


thanks!

H


Here is the full command sequence and checks:


> library(gstat)
Loading required package: sp
> library(spgrass6)
Loading required package: rgdal
Loading required package: abind
Loading required package: pixmap
Geospatial Data Abstraction Library extensions to R successfully loaded
> kk<-idw(glmpred~1,data.new_alb[gd.glm,],data.grd)
[inverse distance weighted interpolation]
> writeRast6sp(kk,"idw_hs",zcol="var1.pred",NODATA=-9999.99)
Error in writeRast6sp(kk, "idw_hs", zcol = "var1.pred", NODATA = -9999.99) 
:
 	only numeric columns may be exported
> str(kk)
Formal class 'SpatialPixelsDataFrame' [package "sp"] with 7 slots
   ..@ data       :Formal class 'AttributeList' [package "sp"] with 1 slots
   .. .. ..@ att:List of 2
   .. .. .. ..$ var1.pred: num [1:208874] 0.503 0.503 0.504 0.504 0.504 ...
   .. .. .. ..$ var1.var : num [1:208874] NA NA NA NA NA NA NA NA NA NA ...
   ..@ coords.nrs : num(0)
   ..@ grid       :Formal class 'GridTopology' [package "sp"] with 3 slots
   .. .. ..@ cellcentre.offset: Named num [1:2] -1333373 -2356259
   .. .. .. ..- attr(*, "names")= chr [1:2] "s1" "s2"
   .. .. ..@ cellsize         : Named num [1:2] 8007 7999
   .. .. .. ..- attr(*, "names")= chr [1:2] "s1" "s2"
   .. .. ..@ cells.dim        : Named int [1:2] 362 577
   .. .. .. ..- attr(*, "names")= chr [1:2] "s1" "s2"
   ..@ grid.index : int [1:208874] 1 2 3 4 5 6 7 8 9 10 ...
   ..@ coords     : num [1:208874, 1:2] -1333373 -1325366 -1317359 -1309352 
-1301345 ...
   .. ..- attr(*, "dimnames")=List of 2
   .. .. ..$ : NULL
   .. .. ..$ : chr [1:2] "s1" "s2"
   ..@ bbox       : num [1:2, 1:2] -1337376 -2360258  1561158  2254928
   .. ..- attr(*, "dimnames")=List of 2
   .. .. ..$ : chr [1:2] "s1" "s2"
   .. .. ..$ : chr [1:2] "min" "max"
   ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots
   .. .. ..@ projargs: chr NA
>

> getGDALDriverNames()
  [1] "GRASS"     "VRT"       "GTiff"     "NITF"      "HFA"       "SAR_CEOS"
  [7] "CEOS"      "ELAS"      "AIG"       "AAIGrid"   "SDTS"      "OGDI"
[13] "DTED"      "PNG"       "JPEG"      "MEM"       "JDEM"      "GIF"
[19] "ESAT"      "BSB"       "XPM"       "BMP"       "AirSAR"    "RS2"
[25] "PCIDSK"    "PCRaster"  "ILWIS"     "RIK"       "GMT"       "netCDF"
[31] "HDF4"      "HDF4Image" "PNM"       "DOQ1"      "DOQ2"      "ENVI"
[37] "EHdr"      "PAux"      "MFF"       "MFF2"      "FujiBAS"   "GSC"
[43] "FAST"      "BT"        "LAN"       "CPG"       "IDA"       "NDF"
[49] "JPEG2000"  "L1B"       "FIT"       "RMF"       "USGSDEM"   "GXF"