Hamish, As usual you had the answer... Thanks.
May I make a suggestion have a small comment added to the documentation page at http://grass.itc.it/grass63/manuals/html63_user/v.voronoi.html to include a note concerning setting the region. In the example it shows a step to set the region, which makes sense now, but upon first reading it I did not catch on. Cheers -----Original Message----- From: Hamish [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 14, 2007 17:40 To: Sampson, David Cc: [EMAIL PROTECTED] Subject: Re: [GRASS-user] V.voronoi David Sampson wrote: > I am ttrying to use the v.voronoi (in wingrass) tool and it is > perplexing me with the results I am getting. Here is the scenario. > > I am trying to anaylise the spatial distribution of road intersections. > I started with a road network file from Statistics Canada, and clipped > out the roads of the city of Ottawa for my subset. I created a new > vector containing only the nodes of the Ottawa network. The resulting > vector has the following basic stats ========= Type of Map: vector > (level: 2) > | > | Number of points: 48156 Number of areas: 0 > | > | Number of lines: 0 Number of islands: 0 > | > | Number of boundaries: 0 Number of faces: 0 > | > | Number of centroids: 0 Number of kernels: 0 > | > | > | > | Map is 3D: 0 > | > | Number of dblinks: 2 > =========== > > The nodes represent both road terminations and intersections. > > I am new to using Voronoi charts but when I run the v.voronoi script I > expect it to create a polygon for each node. > > Instead when I run the basic stats on the new Veronoi vector I get: > > ============= > Type of Map: vector (level: 2) > | > | > | > | Number of points: 0 Number of areas: 1 > | > | Number of lines: 0 Number of islands: 1 > | > | Number of boundaries: 4 Number of faces: 0 > | > | Number of centroids: 0 Number of kernels: 0 > | > | > | > | Map is 3D: 0 > | > | Number of dblinks: 1 > ============= > > I get a rectangular shape that is located just north of ONE of the > nodes in the coverage. As I zoom out some other nodes apear surounding > rectangualr shape... The manual doesn't shed light on my situation. > > Any help, experieince or knowledge would be great. I think that unlike most vector modules v.voronoi works in the current region. Try 'g.region -p vect=nodes_map' before running v.voronoi to set the zoom to cover all points in the input map. ? Hamish ________________________________________________________________________ ____________ Get easy, one-click access to your favorites. Make Yahoo! your homepage. http://www.yahoo.com/r/hs _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
