Fwd: [pgrouting-users] ordering of route edges?

Tue Nov 30 15:32:34 EST 2010

Steve,

I am using the latest released versions (I updated today to see if
that was my issue), and I haven't made any changes to them.

The same thing happens regardless of how long the route is.

I have retried it from scratch today using both a decimal degree
dataset and a meter dataset... when using the decimal degree one the
issues are alot greater, whereas when I use the meter dataset the gid
are reported in numerical order (still not near the right order).

The tolerances I used was 0.00001 for decimal degree and 0.001 for the
meter one.

I'm thinking its probably easiest for me to write a loop in the
wrapper to reorder it.

Madison

On 30 November 2010 01:08, Stephen Woodbridge <woodbri at swoodbridge.com> wrote:
> Madison,
>
> Yeah, the list does not allow attachments. You have to post the image to a
> public site and then put the reference url in the email to the list.
>
> I can't really say what is going on in your example. Most of my code uses
> modified copies of the wrapper functions to meet my specific needs.
>
> Are you using released wrapper routines? or have you made changes to them?
>
> What happens when you make a shorter route?
>
> Is all your data in decimal degrees or some meter/feet projection?
> What did you use for the tolerance value when you ran
> assign_vertex_ids(...)?
>
> -Steve
>
> On 11/29/2010 5:36 PM, Madison Shaw wrote:
>>
>> (I sent this to the list but it got bounced - I hope you don't mind me
>> contacting you directly)
>>
>> Hi Steve,
>>
>> The query I use within my php script returns a geojson.
>>
>> I'm sorry I still don't completely understand why the results don't
>> come back in order... I realise that I may need to flip edges due to
>> the traversing backwards, but at the moment it looks like I need to
>> completely loop through everything to reorder it as well.  I have
>> attached a jpg of how it actually looks for the start of the route
>> with reference to the sql results.
>>
>> Also if you are writing these loops is it best to do it in the php script?
>>
>> Cheers
>>
>> Madison
>>
>>
>>
>> On 29 November 2010 19:54, Stephen Woodbridge<woodbri at swoodbridge.com>
>>  wrote:
>>>
>>> A more useful query would be:
>>>
>>> SELECT gid, astext(the_geom) FROM dijkstra_sp_delta('roads',1,400,0.1)
>>>
>>> Also in dijkstra you pass vertex nodes 1 and 400 BUT you get back edges
>>> in
>>> the order of traversal. The tricky part is that the edge is return as
>>> loaded
>>> and NOT as traversed, so you need to do some checking and flip those
>>> segments that were traversed backwards from the disrtion that they were
>>> loaded.
>>>
>>> -Steve W
>>>
>>> On 11/29/2010 1:46 PM, Madison Shaw wrote:
>>>>
>>>> Hi Daniel,
>>>>
>>>> Thanks for the quick reply, my SQL statement and its results are below
>>>> (with pre selected start and finish points for ease of illustrating my
>>>> issue)
>>>>
>>>> As you can see, the edge (gid) that we start from '1' is given the id of
>>>> 29.
>>>>
>>>> SELECT gid, the_geom FROM dijkstra_sp_delta('roads',1,400,0.1)
>>>>
>>>> Results
>>>>
>>>> id; gid; the_geom
>>>> 1;15;"0102 ... B40"
>>>> 2;17;"0102 ... B40"
>>>> 3;1139;"0102 ... B40"
>>>> 4;746;"0102 ... B40"
>>>> 5;879;"0102 ... B40"
>>>> 6;12;"0102 ... B40"
>>>> 7;1133;"0102 ... B40"
>>>> 8;9283;"0102 ... B40"
>>>> 9;7;"0102 ... B40"
>>>> 10;1137;"0102 ... B40"
>>>> 11;875;"0102 ... B40"
>>>> 12;880;"0102 ... B40"
>>>> 13;634;"0102 ... B40"
>>>> 14;637;"0102 ... B40"
>>>> 15;4;"0102 ... B40"
>>>> 16;18;"0102 ... B40"
>>>> 17;19;"0102 ... B40"
>>>> 18;14;"0102 ... B40"
>>>> 19;1143;"0102 ... B40"
>>>> 20;1135;"0102 ... B40"
>>>> 21;1259;"0102 ... B40"
>>>> 22;109;"0102 ... B40"
>>>> 23;1129;"0102 ... B40"
>>>> 24;1136;"0102 ... B40"
>>>> 25;1130;"0102 ... B40"
>>>> 26;1131;"0102 ... B40"
>>>> 27;1146;"0102 ... B40"
>>>> 28;876;"0102 ... B40"
>>>> 29;1;"0102 ... B40"
>>>> 30;9;"0102 ... B40"
>>>> 31;11;"0102 ... B40"
>>>> 32;1132;"0102 ... B40"
>>>> 33;8759;"0102 ... B40"
>>>> 34;1138;"0102 ... B40"
>>>> 35;1260;"0102 ... B40"
>>>> 36;8;"0102 ... B40"
>>>> 37;10;"0102 ... B40"
>>>> 38;1128;"0102 ... B40"
>>>> 39;1142;"0102 ... B40"
>>>> 40;1134;"0102 ... B40"
>>>> 41;1147;"0102 ... B40"
>>>> 42;16;"0102 ... B40"
>>>> 43;13;"0102 ... B40"
>>>> 44;1140;"0102 ... B40"
>>>> 45;1258;"0102 ... B40"
>>>>
>>>> Cheers
>>>>
>>>> Madison
>>>>
>>>>
>>>>
>>>> On 29 November 2010 18:30, Daniel Kastl<daniel at georepublic.de>    wrote:
>>>>>
>>>>> Hi Madison,
>>>>> Could you send me your routing query to see how it looks like?
>>>>> Daniel
>>>>>
>>>>> 2010/11/30 Madison Shaw<madisonshaw at googlemail.com>
>>>>>>
>>>>>> Hi There,
>>>>>>
>>>>>> I was wondering if someone could help me.  I have pgrouting working
>>>>>> and producing routes using both Dijkstra and AStar, but the edges that
>>>>>> are returned by the SQL are in the wrong order... not the order of the
>>>>>> edges as you expect to move through the route from start to finish...
>>>>>>
>>>>>> eg: (using a short example)
>>>>>>
>>>>>> If I have a route of ten edges, from start edge 1 to finish edge 10 -
>>>>>> I would expect the results to be: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 (using
>>>>>> the id column that is returned from the sql)
>>>>>>
>>>>>> However, the results are more like 3, 6, 2, 8, 1, 9, 4, 7, 10, 5.
>>>>>>
>>>>>> Is this supposed to happen? Is there a way to return the results in
>>>>>> the order you traverse through the route?
>>>>>>
>>>>>> Cheers
>>>>>>
>>>>>> Madison
>>>>>> _______________________________________________
>>>>>> Pgrouting-users mailing list
>>>>>> Pgrouting-users at lists.osgeo.org
>>>>>> http://lists.osgeo.org/mailman/listinfo/pgrouting-users
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Georepublic UG&    Georepublic Japan
>>>>> eMail: daniel.kastl at georepublic.de
>>>>> Web: http://georepublic.de
>>>>>
>>>>> _______________________________________________
>>>>> Pgrouting-users mailing list
>>>>> Pgrouting-users at lists.osgeo.org
>>>>> http://lists.osgeo.org/mailman/listinfo/pgrouting-users
>>>>>
>>>>>
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