[GRASSLIST:7269] Re: how to find points of intersection between lines

[Moritz Lennert]

On Fri, June 17, 2005 9:51, Hamish said:
>> A question from the French Users list: how can one find points of
>> intersection between lines ?
>>
>> Concrete example: if you have a layer containing a network of rivers
>> and another layer containing a network of roads, how can you create a
>> point vector layer containing the points of intersection ?
>>
>> If understand correctly, v.overlay only supports vector areas, or ?
>
>
> just a guess:
>
> v.patch
> v.clean tool=break err=intersections
> v.out.ascii intersections
>

This works to get coordinates, but you don't get the information of which cat
river and which cat road intersect. That would be nice to have if you have
large networks... v.overlay might work for this if it supported points (i.e.
v.overlay ainput=intersections binput=roads operator=and).

Moritz