Dear Bianca, On Thu, Mar 30, 2017 at 5:27 PM, Markus Metz <[email protected]> wrote: > On Thu, Mar 30, 2017 at 3:48 PM, Bianca Federici <[email protected]> ... >> The contour lines are quite coarse, and I can surely try to use other >> interpolation methods... but the point is: >> r.surf.contour works well??? > > I don't think so.
Yes, there are much better methods than r.surf.contour. See also here: https://grasswiki.osgeo.org/wiki/Contour_lines_to_DEM markusN >> it's seems to me that no linear interpolation between two contour levels >> is perfomed, in fact the slope is not constant between them but increase >> until half the distance and then decrease, or viceversa, instead of being >> constant. > > There are indeed strange patterns in the slope values between contour lines. > The used distance to the second contour is not the shortest distance to the > second contour, that is a bug. The distance calculation is unusual, it is > not euclidean and not manhattan distance, no idea what kind of distance this > is. > > Apart from that, I would not use linear interpolation to create a surface > from contour lines but use one of the previously mentioned r.resamp.* > modules. And r.surf.contour is incredibly slow. > > Markus M _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
