On Fri, Aug 26, 2016 at 5:28 AM, Vaclav Petras <[email protected]> wrote: > Hi Markus, > > On Thu, Aug 25, 2016 at 3:02 PM, Markus Metz <[email protected]> > wrote: >> >> The new addon v.surf.tps performs multivariate thin plate spline >> interpolation of sparse points with smoothing. > > really interesting. I did some preliminary tests and I might provide some > feedback later. For now I updated the examples in the manual in r69259, so > please update your svn copy. > >> If you ever wondered >> why worldclim data (http://worldclim.org) follow so nicely elevation, >> the reason is multivariate thin plate spline interpolation of >> meteorological station data with elevation as a covariate. >> [...] The module works only with GRASS 7.2+. > > It may be useful to note that you can preform similar operation with any > version of GRASS GIS using v.vol.rst (3D interpolation using regularized > spline with tension). The trick is using cross_* parameters to extract the > desired 2D raster.
For one covariable, yes, but not for more covariables. E.g. worldclim has been interpolated using elevation, latitude and longitude as covariables. And v.vol.rst is rather slow. Markus M > Here is an example from [2]: > > g.region raster=elev_state_500m -p > g.region t=2000 b=0 tbres=2000 res3=500 -p3 > v.vol.rst input=precip_30ynormals_3d \ > cross_input=elev_state_500m cross_output=precip_anntopo_500m \ > maskmap=elev_state_500m wcolumn=annual zscale=90 segmax=700 > > Thanks! > Vaclav > > [1] https://trac.osgeo.org/grass/changeset/69259 > [2] > http://ncsu-geoforall-lab.github.io/geospatial-modeling-course/grass/interpolation_2.html _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
