[GRASS-user] v.net.iso - service area

[David Mahoney]

On Sat, 2010-04-10 at 08:16 +1000, Richard Chirgwin wrote:
> David,
> 
> I'd just like to confirm the process ...
> 
> 1. Obtain points you wish to use as the service area edge nodes (I will 
> call this vector "Limit").
> 2. Run v.delaunay to create a vector that includes the outline 
> (map=Delaunay).
> 3. Run v.net to connect Limit to Delaunay (map=Network)
> 4. Run v.net.salesman on Network to create the final service area map.
> 
> This seemed to work fine for me in Spearfish.
> 
> One question - I created the "point set" manually. But if have a network 
> of lines, what's the best way to create a point vector from the line ends?
> 

As I recall, I parsed the output of v.build using the dump option, and
passed that into v.extract.

There are probably a bunch of edge cases where this approach fails
though. The one that comes to mind is the case where there is a section
of a service area that is strongly convex that protrudes into another
service area.

David

-- 
______________________________________________________________________
David Mahoney                   GIS Analyst
david.mahoney at tecogroup.ca      TECO Natural Resource Group
Tel: (250) 562-2628 ext 232     Fax: (250) 562-694              
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