Center nodes have to be assigned to vector nodes. Nodes and arcs can be closed using cost = -1.
# Spearfish # start node: echo "591280.5|4926396.0|1" | v.in.ascii out=startnode g.copy vect=roads,myroads #create line map connecting point to network v.distance -p from=startnode to=myroads out=connect upload=dist column=dist # fix missing category number: v.category connect out=connect2 op=add d.vect myroads d.vect startnode col=red d.vect connect2 col=green v.patch in=myroads,connect2,startnode out=roads_n v.clean roads_n out=roads_net tool=snap,break thresh=5,0 # specify range of center cats (easier to catch all): v.net.iso input=roads_net output=isomap ccats=1-100000 costs=1000,2000,5000 nlayer=1 v.category isomap option=report # ... reports 4 categories:
cat | distance from point 1 0 - 1000 2 1000 - 2000 3 2000 - 5000 4 > 5000
d.erase d.vect isomap col=blue cats=1 d.vect isomap col=green cats=2 d.vect isomap col=yellow cats=3 d.vect isomap col=red cats=4
Last changed: $Date: 2007/07/22 23:54:59 $