[pgrouting-users] TSP and how to contribute

[Emre Koc]

/emre


On Fri, Jan 14, 2011 at 10:15 AM, Daniel Kastl <daniel at georepublic.de>wrote:

>
>
> 2011/1/14 Emre Koc <emrekoch at gmail.com>
>
> Sure
>>
>> Here is my sql query for that image.
>>
>> SELECT edges.gid, ST_AsText(edges.the_geom) AS geotext,
>>                  edges.ft_minutes,
>>  edges.meters
>> FROM edges,
>> (SELECT edge_id, cost FROM driving_distance('SELECT gid as id,
>>  source::integer,
>>  target::integer,
>>          meters::double precision as cost
>>  FROM edges', $startVertexID, $cost,false,false)
>> )  as rt
>> WHERE edges.gid=rt.edge_id;";
>>
>> I just give a sample vertex id and a cost value in meters and got
>> resulting edges. Normally when I find shortest paths all roads are connected
>> so the graph is ok. But this driving directions does not output connected
>> roads, thats the thing I do not understand.
>>
>
> Driving distance returns you all the vertices you can reach from a start
> point to within what you have defined as the maximum costs.
> I think you're looking for another query (Dijkstra, A-Star, Shooting Star).
>

I am looking for a output that shows road network that I can reach from a
start point within a defined maximum cost. So if driving distance does not
output connected edges what do you suggest me to do in order to have a
connected road network with the given vertices ? Running shortest path for
each vertex does not seem feasible but I am unable to see a way to implement
it without going inside c functions.



>
> The edge column in driving distance doesn't return a "useful" result as I
> just answered the day before in this message:
> http://lists.osgeo.org/pipermail/pgrouting-users/2011-January/000474.html
>
> Daniel
>
>
>
>
>
>
>
>>
>> /emre
>>
>>
>> On Fri, Jan 14, 2011 at 5:26 AM, Daniel Kastl <daniel at georepublic.de>wrote:
>>
>>>
>>>
>>>> I checked driving directions functionality and seems like the feature
>>>> that I was looking for. But It returns non connected edges which are close
>>>> by a cost. Do you know how does this function really work ? Here is my
>>>> screenshot  http://db.tt/0bb62XB. Shouldn't the output be connected ?
>>>>
>>>
>>> Could you tell us what you did exactly? The query for example.
>>>
>>> Daniel
>>>
>>>
>>> --
>>> Georepublic UG & Georepublic Japan
>>> eMail: daniel.kastl at georepublic.de
>>> Web: http://georepublic.de
>>>
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>>>
>>
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>>
>
>
> --
> Georepublic UG & Georepublic Japan
> eMail: daniel.kastl at georepublic.de
> Web: http://georepublic.de
>
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