[pgrouting-users] Wierd results using pgr_kdijkstraPath

[Stephen Woodbridge]

Eyad,

What does you geomerty look like?
Select st_astext(geom) from edges limit 10;

What value did you use for tolerance when creating your topology?
What value did you use for tolerance when you noded your network?

-Steve

On 12/18/2014 10:17 AM, AUS - Eyad wrote:
> And here I enclose below the resulted travel_costs’ table of
> pgr_dijkstra function:
>
> Note that Shortest path cost on original network (between the 2 lines of
> the resulted vector feature) is around 250m (below - by converting from
> millimeter to meter) whereas the sum of costs in the above table is
> around 45m only
>
> Thanks..
>
> Eyad
>
> *From:*AUS - Eyad [mailto:b00038807 at aus.edu]
> *Sent:* Thursday, December 18, 2014 7:02 PM
> *To:* 'pgRouting users mailing list'
> *Subject:* RE: [pgrouting-users] Wierd results using pgr_kdijkstraPath
>
> Here is a prt_sc after trying pgr_dijkstra as follows:
>
> SELECT seq, id1 as path, (b.geom) as geom, cost FROM pgr_dijkstra(
>
>      'SELECT id, source, target, (st_length(geom) * 0.001) as cost FROM
> schema.network_noded',
>
>      336, (SELECT MAX(id) FROM schema.l1_pv1), false, false
>
>    ) a, schema.network_noded b
>
> WHERE a.id1=b.id
>
> As you may see, there is only too little parts of the network’s lines
> left (on the sides of the layout)! No route is visible
>
> Hope this clarifies..
>
> Eyad
>
> *From:*AUS - Eyad [mailto:b00038807 at aus.edu]
> *Sent:* Thursday, December 18, 2014 6:29 PM
> *To:* 'pgRouting users mailing list'
> *Subject:* RE: [pgrouting-users] Wierd results using pgr_kdijkstraPath
>
> Hi Daniel,
>
> Enclosed are 3 maps (1^st prt_sc with the original network, 2^nd & 3^rd
> prt_sc with the resulted network)
>
> Clearly, the majority of the network has faded away
>
> Awaiting your feedback, I would work on 2^nd suggestion
>
> Regards,
>
> Eyad
>
> *From:*pgrouting-users-bounces at lists.osgeo.org
> [mailto:pgrouting-users-bounces at lists.osgeo.org] *On Behalf Of *Daniel Kastl
> *Sent:* Thursday, December 18, 2014 6:28 AM
> *To:* pgRouting users mailing list
> *Subject:* Re: [pgrouting-users] Wierd results using pgr_kdijkstraPath
>
> Hi Eyad,
>
> It's difficult to give an answer based on your query and problem
> description only. I guess, that (still) your network topology is not
> correct. It looks like a data problem.
>
> There are 2 things you could do for now:
>
> (1) Show us some image of your "weird de-attached “little” pieces"
>
> (2) Try a simple shortest path query with one start and one end point
> and see if it works with pgr_dijkstra function for example.
>
> Daniel
>
> On Thu, Dec 18, 2014 at 7:37 AM, AUS - Eyad <b00038807 at aus.edu
> <mailto:b00038807 at aus.edu>> wrote:
>
> Hello pgr_Experts,
>
> I’m trying to get all the routes from a source point (i.e. 336) to a
> group of target/destination points (located at different edges/ends of
> linestrings’ network) using the below code:
>
> SELECT seq, id1 as path, id2 as node, id3 as edge, (b.geom) as geom,
> cost FROM pgr_kdijkstraPath(
>
> 'SELECT id, source, target, (st_length(geom) * 0.001) as cost FROM
> schema.network_noded',
>
> 336, (SELECT array_agg(id) FROM schema.l1_pv1), false, false
>
> ) a, schema.network_noded b
>
> WHERE a.id1=b.id <http://b.id>
>
> It’s resulting a weird de-attached “little” pieces of my original
> nodded_network! However, the number of resulted paths is equal to the
> target/destination points. Please advise:
>
> 1)What potential mistake I may have committed?
>
> 2)Does it mean that all the calculated travel_cost(s) are wrong (as they
> are reflected/represented by wrong linestrings)?
>
> I'm using QGIS 2.4.0 and pgRouting pg93-binaries-2.4.0
>
> I found similar question on this list of pgRouting users, asked by
> Antonio last October
> (http://lists.osgeo.org/pipermail/pgrouting-users/2014-October/001992.html
> ), but obviously the question is not answered yet?
>
> Regards..
>
> Eyad
>
>
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>
> --
>
> Georepublic UG & Georepublic Japan
> eMail: daniel.kastl at georepublic.de <mailto:daniel.kastl at georepublic.de>
> Web: http://georepublic.info
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