Hi,
I have imported an x,y,z DEM file (grid points with floating point location and height values) into GRASS 6.0.1, using the v.in.ascii command's GUI. The generated command was:
> v.in.ascii input=DEM10.xyz output=v format=point fs=' ' x=1 y=2 z=3 cat=0 -z -t
(I have used "create 3D file" and "Do not create table in points mode", although I did not grok their meaning from the manual.)
I have then taken the region from the vector map v and set the resolution corresponding to the DEM file contents:
> g.region vect=v res=10
d.what.vect shows the correct z values, when v is displayed.
Then I generated an intermediate raster map (because I could not make v.surf.idw work, but that's another story):
> v.to.rast input=v output=r use=z
(Data type DCELL and data range in r.info still look ok.)
When I now use "inverse distance weighed average interpolation" like this
> g.region res=20 #target resolution
> r.surf.idw input=r output=r_idw20
, the generated raster map gets the integer data type CELL! Why doesn't it generate floating point values, as generated by the interpolation formula?
(When I use r.resamp.rst instead, the resulting type is floating point (FCELL), as expected.)
-- Robert