[GRASS-user] More on v.net.steiner

[Richard Chirgwin]

Markus Neteler wrote:
> On Wed, Sep 9, 2009 at 7:14 AM, Richard
> Chirgwin<rchirgwin at ozemail.com.au> wrote:
>   
>> All,
>>
>> I found a brute-force way to identify the unreachable categories; I set up a
>> loop in d.path to connect all categories to all others, with the output
>> pipelined to a text file along with cats.
>>     
>
> Wouldn't v.net do the job?
>
> http://grass.osgeo.org/grass64/manuals/html64_user/v.net.html
> -> Example
>     "... create lines map connecting points to network (on layer 2)"
>
> Markus
>
>   
Markus,

I had already run v.net to create the connection from point to network. 
Where it fell down was for points that couldn't connect, because 
v.net.steiner reports the failure to connect using node number rather 
than category number (so for eg the cat might be 10 but the node 639). 
My nasty brute-force was to create a text file that clearly put node 
number and cat number together.

(The network was roads; the points that didn't connect were in the 
water, which is fair enough I suppose!)

Richard