[GRASS-user] MAP Calculator mean of eight neighbors to interpolate 0 value in raster map

[Glynn Clements]

stephen sefick wrote:

> This does not quite work for my purposes.  The problem is the the 0
> values are in a 2 or 3 grid wide seam in between patched raster maps,
> so the value is lower than it should be using
> 
> r.mapcalc "benning_dem=if(patch_benning==0,
> (patch_benning[-1,-1]+patch_benning[1,-1]+patch_benning[-1,0]+
> patch_benning[1,0]+patch_benning[-1,1]+patch_benning[1,1])/6,
> patch_benning)"
> 
> any thoughts,

Do you want the average of all of the surrounding values, or only the
non-zero values?

If you replace the zeros with nulls, you can use r.neighbors and
r.patch.

-- 
Glynn Clements <glynn at gclements.plus.com>