Re: [GRASS-user] RE: Network Analysis output in GRASS
On Tue, Jun 9, 2009 at 6:50 AM, Donald Catanzaro, PhDdon.catanzaro@gmail.com wrote: Hi All, I am returning to GRASS after a 10 year hiatus and I must say that I am impressed ! Welcome back :) I am working on some simple network analysis (road distances from a point) and want the output to appear as concentric rings. I think I need to use v.net.iso on my road network but it appears from the manual that the output from v.net.iso is a line file. I'd like to push that out to a polygon to get concentric rings so it looks like I need a few more processing steps. Like I said, it has been a long while since my GRASS4.0/4.1 days - what would people suggest using to push the output of v.net.iso out to a polygon ? v.surf.idw, v.surf.icw, v.hull ? Aren't these all point interpolations and I need to interpolate from lines ? Wild guess: connect points with identical attribute? Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] RE: Network Analysis output in GRASS
Donald wrote: I am returning to GRASS after a 10 year hiatus and I must say that I am impressed ! I am working on some simple network analysis (road distances from a point) and want the output to appear as concentric rings. I think I need to use v.net.iso on my road network but it appears from the manual that the output from v.net.iso is a line file. I'd like to push that out to a polygon to get concentric rings so it looks like I need a few more processing steps. Like I said, it has been a long while since my GRASS4.0/4.1 days - what would people suggest using to push the output of v.net.iso out to a polygon ? v.surf.idw, v.surf.icw, v.hull ? Aren't these all point interpolations and I need to interpolate from lines ? perhaps v.to.db option=start/end to get endpoints and then string them together into a new vector line or run v.hull? or similarly but with 'v.to.points -n'. getting the line vertex order right might be a pain. v.hull isn't the best as it cuts across bays in the blob, but other than manual approaches (like above or digitizing by hand around the lines with v.digit then snapping to underlying vertices), I'm not sure. Keen to hear any other solutions though. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] RE: Network Analysis output in GRASS
Donald wrote: I am working on some simple network analysis (road distances from a point) and want the output to appear as concentric rings. I think I need to use v.net.iso on my road network but it appears from the manual that the output from v.net.iso is a line file. how about after v.net.iso v.to.rast + r.grow? it would extend rings a bit outwards, but.. H ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] RE: Network Analysis output in GRASS
Hi All, I am returning to GRASS after a 10 year hiatus and I must say that I am impressed ! I am working on some simple network analysis (road distances from a point) and want the output to appear as concentric rings. I think I need to use v.net.iso on my road network but it appears from the manual that the output from v.net.iso is a line file. I'd like to push that out to a polygon to get concentric rings so it looks like I need a few more processing steps. Like I said, it has been a long while since my GRASS4.0/4.1 days - what would people suggest using to push the output of v.net.iso out to a polygon ? v.surf.idw, v.surf.icw, v.hull ? Aren't these all point interpolations and I need to interpolate from lines ? Thanks in advance ! -Don ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
