Also, even when I zoom in to extract only one contour, the exported points are not always in order in the file, in a way that when I use it to plot in another program as a line, it connects the points in a wrong way.
How can I export contours in an amenable way to use in other programs, such as Matlab, for instance? Thanks in advance. Marcello. Marcello Gorini wrote: > > Dear all, > > I am interested in extracting the longest -1,000 meter contour from a > bathymetric DEM and to save it in a text file as points. > > By doing: > > r.contour in=my_dem out=contour levels=-1000 > v.to.points in=contour out=contour_points dmax=my_resolution > v.out.ascii in=contour_points out=contour_points.txt fs=" " dp=4 > > ... I get a text file with the contour points, however, it includes many > different isolated contours, all with the same category (1). > > Since I need only the longest, I believe I need to separate the different > contours, maybe assigning different categories somehow, then maybe > updating the database with v.to.db using option=length and then > v.db.select the longest contour. > > But I am not very used to working with vectors, so I don't know if that's > the correct approach (nor how to accomplish it), so I would appreciate > very much any help. > > Many thanks. > > Marcello. > -- View this message in context: http://osgeo-org.1803224.n2.nabble.com/How-to-extract-one-single-contour-tp6639491p6641376.html Sent from the Grass - Users mailing list archive at Nabble.com. _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user