On 02/07/2011 03:58 AM, Alex Lechner wrote: > Hi, > > I have a number of point measurements of soil electrical conductivity > surrounding a large pond (see > http://www.flickr.com/photos/32778961@N04/5423900854/ ) which I am trying to > create a kriged surface for. Is there any way of excluding distances across > the pond in the variogram calculations (see > http://www.flickr.com/photos/32778961@N04/5423901056/ ). > I guess with a lot of work -- using package rgeos, check every point pair whether the line connecting them crosses the pond, then exclude these pairs from the variogram cloud and bin them.
I'm not sure how much it would help you. You'd not be the first if in a next step you'd like to krige and exclude points that cross the pond -- an action that can lead to very weird interpolation surfaces, because points suddenly appear "visible" when turning around a corner. Have you tried including a trend with distance to the pond? > Thanks, > > Alex Lechner > > Research Fellow > Centre for Mined Land Rehabilitation > Sustainable Minerals Institute > Level 5, Sir James Foots Building (47A) > Cnr Staff House and College Roads > University of Queensland > ST LUCIA, QLD, 4072 > w: +61 (0)7 3346 4021 > m: +61 (0)401 233 019 > f: +61 7 3346 4056 > e: a.lech...@uq.edu.au > > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of Münster Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebe...@wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
