Thanks Markus, This is very close to the methods we used in the last month to rebuild early Holocene landscapes in eastern Spain. Your tips are very useful. I only wish we'd had them before we did a lot of experimentation.
Cheers Michael ______________________________ C. Michael Barton Director, Center for Social Dynamics & Complexity Professor of Anthropology, School of Human Evolution & Social Change Arizona State University Tempe, AZ 85287-2402 USA voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC) fax: 480-965-7671(SHESC), 480-727-0709 (CSDC) www: http://csdc.asu.edu, http://shesc.asu.edu http://www.public.asu.edu/~cmbarton On Jun 21, 2010, at 9:00 AM, [email protected] wrote: > Message: 2 > Date: Mon, 21 Jun 2010 08:29:31 -0000 > From: "GRASS GIS" <[email protected]> > Subject: [GRASS-dev] Re: [GRASS GIS] #1088: r.fillnulls: support other > interpolation methods > To: undisclosed-recipients:; > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > #1088: r.fillnulls: support other interpolation methods > -------------------------+-------------------------------------------------- > Reporter: kyngchaos | Owner: grass-...@??? > Type: enhancement | Status: new > Priority: normal | Milestone: 6.5.0 > Component: Raster | Version: svn-develbranch6 > Keywords: fillnulls | Platform: All > Cpu: All | > -------------------------+-------------------------------------------------- > > Comment(by mmetz): > > In grass 7, it's already implemented in r.resamp.bspline. r.resamp.bspline > interpolates a raster to the current resolution, filling NULL cells on the > fly, or optionally only interpolates NULL > cells. Available methods are bilinear and bicubic, tested with SRTM data, > filling large gaps in the European Alps. > > For grass 6.x, I would use a different approach to r.fillnulls to follow > the design of v.surf.bspline, because only interpolating NULL cells is > already possible with v.surf.bspline: > > Create a new raster where NULL cells in the original surface raster are > set to something else than NULL, others to NULL. Convert both raster maps > to vector points. Use the vector points representing NULL cells as sparse > points input for v.surf.bspline. Recommended settings for v.surf.bspline > in this case are sie = 2 * ewres, sin = 2 * nsres, lambda = 0.005 (best in > my tests, should be somewhere between 0.001 and 0.01). The output raster > holds the interpolated NULL cells and can be patched with the original > surface. > > Although all lidar tools work within the current region, none respects a > MASK. I'm not sure how this could be implemented properly and efficiently, > currently there will be IMHO harmless warnings about no points in the > current subregion. > > Markus M > > -- > Ticket URL: <https://trac.osgeo.org/grass/ticket/1088#comment:7> > GRASS GIS <http://grass.osgeo.org> > _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
