[STATSGRASS] Interpolation of grass's contour data ?

[Roger Bivand]

On Tue, 11 Nov 2003, temiz wrote:

> hello
> 
> is there any way in R to interpolate grass's contour (vector) data with 
> Krig method ?
> 

When I see contour data, I usually try out r.surf.contour on a raster 
layer made from contours. It takes account of the fact that there are very 
many observations with the contour level values better than other *.surf.* 
choices. An alternative might be to sample the contours to reduce the 
number of near points with the same z values, and use one of the s.surf.*, 
maybe, depending on your data. In any case, the output will be terraced, 
because most interpreters believe the input data, which are mostly at 
levels. Adding fill-in points on summits and in depressions can help. I 
think that r.surf.contour is still just integer and 0 is treated as NULL, 
so you may need to use r.mapcalc on the input first to rescale it.

Roger

> cordially
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand at nhh.no