Q: s.surf.idw

[Precision Farming Project]

In article <9611221338.AA11278 at gphsun1.uni-bremen.de>, 
andreas at gphsrv1.geophyS2.uni-bremen.de says...
>
>We do have a site-list of field measurements
>(soil resistivity) which we interpolate to
>raster by means of s.surf.idw.
>
>Z-values in the site-list are floating-point
>ranging from 0.0 to 25.0.
[ ... ]
>Thanks for your help,
>
>Andreas
>Dept. of Geophysics
>Univ. of Bremen

Andreas, I would try multiplying your Z values (resistivity)
by some scalar (say 10), and trying again.  You may be
getting bitten by the fact that most (some?) of GRASS is
integer.

Gordon Haverland
Precision Farming Project
Alberta Agriculture