[GRASS-user] Snapping Points to Nodes along Lines

[Moritz Lennert]

On 29/09/08 01:44, Ryan R. Rosario wrote:
> I have one vector map consisting of 30831 points, and another consisting of a
> road network. I have used the v.distance function followed by v.clean to
> connect each point to the nearest road. I used the errors from v.clean to
> obtain the intersections: basically, each point's projection onto a road.
> 
> #v.distance -p from=incidents to=roads out=connect upload=dist column=dist
> #v.patch roads,connect,points out=patched
> #v.clean patched output=patched_clean err=intersections tool=break,snap
> 
> The problem is, the error layer (intersections) only contains 6715 points
> but for my next step I need to have the same number of intersections as data
> points.
> 
> (In the next step, I want to take this layer of intersections (points) and
> locate the nearest point in another layer along a road, so I need to have
> the same number of intersections as I have data points)
> 
> What am I misunderstanding about the v.clean process? Is there some way I
> can fix this?

Don't have an answer to your question concerning v.clean, but you could 
also use v.net with operation=connect.

Moritz