Hi, I am going to do some work on drainage networks I created. I could not figure out some basic procedures. Maybe, you have some ideas how to work with some of the following questions/tasks:
1) how is a network stored? creating it via v.net from a multiline "map" says it wants to create two layers: one with lines, the other with points -> general problem: creating an table containing an entry for every object (Id). I know thats general, but why doesn't it work with v.db.newtable? And why answers v.to.db option=cat with "Reading features... Updating database... 0 categories read from vector map (layer 1) 0 records updated/inserted (layer 1)"? 2) how can I identify each network by eg. an integer value? There are many unconnected trees, which I want to keep separated. -> I tried it with v.buffer, on the one hand I couldn't upload the information to the network (points and polylines) and on the other hand it takes a lot of time. 3) can I define a "direction" of a network with values on the nodes? like a sorted tree? in order to get the sub trees? 4) how can I find out, which and how many lines are connected to a node? 5) ...there are some, but I think its enough; and furthermore the questions more or less depend on each other. Hoping, someone has some experience with that kind of stuff, kindly regards, Achim _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
