Re: [GRASS-user] Measuring Distance Along a Line
On Fri, 20 Jan 2012, Maris Nartiss wrote: if You are interested to get similar functionality like r.profile does for raster, there's a GRASS add-on v.profile, that allows to profile vector point and line maps. Area support is not implemented. Maris, This is good to know. Thank you, Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Measuring Distance Along a Line
Hello, if You are interested to get similar functionality like r.profile does for raster, there's a GRASS add-on v.profile, that allows to profile vector point and line maps. Area support is not implemented. Input for v.profile should be a map with a single transect line (or single line should be selected with SQL) or Northing, Easting value list representing line and a map with points/lines. Module output will be a list of feature (point within specified tolerance, line crossing) distance from the start of profile line + feature attribute data. If You need some help, let me know. Maris. http://grass.osgeo.org/wiki/GRASS_AddOns#v.profile http://trac.osgeo.org/grass/browser/grass-addons/grass6/vector/v.profile 2012/1/18 Rich Shepard rshep...@appl-ecosys.com: I have a map with a couple of transect lines that intersect points on a separate map. I want to measure the distance from one end of each transect line to the point which it overlays. While I thought there was a v. module to do this, I'm not seeing it. If it's v.distance, I don't see how to apply that module to measuring a distance along one line interactively. Clue stick needed. Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Measuring Distance Along a Line
On Wed, Jan 18, 2012 at 4:07 PM, Rich Shepard rshep...@appl-ecosys.comwrote: I have a map with a couple of transect lines that intersect points on a separate map. I want to measure the distance from one end of each transect line to the point which it overlays. While I thought there was a v. module to do this, I'm not seeing it. If it's v.distance, I don't see how to apply that module to measuring a distance along one line interactively. Again, vectors are not my thing, but maybe you could include the end point into your vector and use v.to.db with option=length to get the distance along your line vector. A raster solution to similar problems that you could maybe use somehow is to generate distance maps from target points, lines or areas and then extract the values of these maps through other vectors or using r.mapcalc. I've used this solution in many different cases and it is very nice to see the distance maps. The procedure is described in the GRASS book as: r.mapcalc area_one=1 r.cost -k in=area_one out=distance_to_something start_rast=something r.mapcalc approx_distance_in_meters=dist_to_something * (ewres() + nsres()) / 2.) Hope it gives you some insights. Marcello. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Measuring Distance Along a Line
On Wed, 18 Jan 2012, Marcello Gorini wrote: Again, vectors are not my thing, but maybe you could include the end point into your vector and use v.to.db with option=length to get the distance along your line vector. Marcello, I don't want the endpoint, but the distance where it overlays a point from a different map. Hope it gives you some insights. Thank you. Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Measuring Distance Along a Line
On 01/18/2012 12:32 PM, Rich Shepard wrote: On Wed, 18 Jan 2012, Alex Mandel wrote: I'm not sure I get what you're trying to do, but distance along a line would be in the v.net module. Alex, When I read the v.net man page it suggested that it provided distances from node-to-node on a network map. The profile map I created is separate from the points map, and I'm looking for the distance to the point along the line. However, it occurred to me that I can get this from the r.profile output because the points are just above the stream channel so they'll be slightly higher in elevation than the lowest point on the profile. That's good enough for presentation purposes. Thanks, Rich I think I'd need to see a diagram to understand the setup better. There is a v.patch tool that connects a point to the nearest location along lines. After which you can measure the patch distance. Glad you found something that works though. Alex ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
