Christian, Barry's suggestion to make a DEM from the points then generate contours from the DEM is a good one. I have used GRASS for this task with great success:
1. Import the points with v.in.ogr 2. Generate a DEM using spline tensioning (v.surf.rst) 3. Generate contours with r.contour 4. Export the contours with v.out.ogr A while back I posted a little tutorial of a similar process for generating contours from depth soundings... http://www.perrygeo.net/wordpress/?cat=3. Of course this means you'll have to get the GPX files into a shapefile first. "gpx2shp" works great for this. I've never set up gpx2shp or GRASS on windows before but I'd imagine it can be done.. probably much easier on linux though ;-) GRASS might be a bit hard to get started with but it is well worth it! Oh, another option for creating DEMs from points is SAGA GIS which has a module that will do delaunay triangulations and output a grid. You could then use another program to generate contours from that. Matt On 1/21/06, Barry Hunter <[EMAIL PROTECTED]> wrote: > Ok I know you specially ask for a direct route, but if you can generate a > dem from your data (don't know of a program for that!) then there is > dem2topo which will create contours. > > You might also like to checkout the code from free-map.org.uk as that does > on the fly contour generation. > > Barry > > - www.nearby.org.uk - www.geograph.org.uk - www.trigtools.co.uk - > > ----- Original Message ----- > From: "Christian Nold" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Saturday, January 21, 2006 9:17 PM > Subject: [Geowanking] contour rings from GPX > > > > Hi , > > > > Hi there I have a large number of GPX files that I would like to use > > for creating filled contour rings of an area. > > > > Ideally I would like to use the files as they are and not have to > > convert them to X,Y,Z and it would be fantastic if I could export the > > contours as vectors. > > > > Could somebody please recommend me some easy to use - open > > source/freeware (windows) programs that could do this? > > > > Any help would be really appreciated! > > > > -- > > Thanks > > Christian > > > > > > Web: www.softhook.com > > Web: www.biomapping.net > > > > _______________________________________________ > > Geowanking mailing list > > [email protected] > > http://lists.burri.to/mailman/listinfo/geowanking > > > > > > _______________________________________________ > Geowanking mailing list > [email protected] > http://lists.burri.to/mailman/listinfo/geowanking > -- Matt Perry [EMAIL PROTECTED] http://www.perrygeo.net _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
