Ok Moritz, Thanks for the tips. I'll try to go the centroids way
Cheers Daniel On Tue, Mar 3, 2015 at 5:35 AM, Moritz Lennert <[email protected] > wrote: > On 02/03/15 21:39, Daniel Victoria wrote: > >> Hi list, >> >> I'm beginning to learn and use the v.net <http://v.net> tools in Grass >> in order to evaluate the distance from several crop fields to a >> processing plant. >> >> I've successfully build the road network with the end nodes but now I'm >> in doubt. My starting points in the analysis are crop fields, which are >> polygons. So what is the best (or most common) practice? >> >> 1) Use the field centroids as starting nodes? >> 2) Add field polygon boundaries to the network and run v.net.distance >> backwards (from mill to fields)? >> 3) Some other option? >> > > > I don't think that there is a best practice for this. It all depends on > your application and the desired outcome. Do you want average time/distance > from anywhere in the field to the plant ? Then probably the centroid is ok. > Or do you want distance from the point of the field that is closest to the > network ? Then you could get the coordinates of that point through > v.distance (with upload=to_x,to_y) and use these points as nodes. > > > > Also, if I'm to add the field boundaries to the network, how would I go >> about it? Should I first v.patch the field with the roads layer and then >> run v.net <http://v.net>? >> > > Adding field boundaries still does not answer the question of where to put > the start/stop point of your paths... > > If you want to add them to the network then yes, patching would be the > best option, AFAIK. > > Moritz > > >> Thanks >> Daniel >> >> >> _______________________________________________ >> grass-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/grass-user >> >> > >
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