[GRASS-user] Finding Nearest Intersection (point) on Road Network

[Ryan R. Rosario]

GRASS simply returns the same point back, since the closest node to A is A.
If I use patch first, then the from and to maps in v.distance must be the
same, unless I am misunderstanding something. 

The vector map containing the intersections (the set of points B) contains
both points (created using v.net nodes) and lines (the original road
network). I can get the nearest point using v.distance, but this uses
straight-line distance, not the distance along the road. 

Although v.distance offers the "to_along" option, there does not appear to
be anywhere to specify which vector contains the road network. And it seems
that v.net.path requires that both the start and end points must be known a
priori, and I only have the start point. I am trying to find the end point
(the nearest intersection). I am stuck, but I think I am missing something
important here.


Markus Neteler OSGeo wrote:
> 
> On Sat, Dec 20, 2008 at 9:04 PM, Ryan R. Rosario <uclamathguy at gmail.com>
> wrote:
>>
>> I have two vector maps consisting of points and a vector map containing a
>> road network. Given a point A, I want to find the nearest point B along
>> the
>> road network, for each A.
>>
>> I have looked at v.net.path and v.distance's to_along but they seem to
>> require B to be known. How can I do this?
> 
> Suggestion: v.patch first, then the others.
> 
> Markus
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-user
> 
> 

-- 
View this message in context: http://www.nabble.com/Finding-Nearest-Intersection-%28point%29-on-Road-Network-tp21108480p21155428.html
Sent from the Grass - Users mailing list archive at Nabble.com.