[mapserver-users] optimal path between two points.

[Valeria Muñoz]

example

the query is optimal path between 887 y 852. :
SELECT rt.gid, AsText(rt.the_geom) AS wkt,
                   length(rt.the_geom) AS length, calle.gid
                FROM calle,
                    (SELECT gid, the_geom
                        FROM dijkstra_sp_delta(
                            'calle',
                            887,
                            852,
                            3000)
                     ) as rt
                WHERE calle.gid=rt.gid;
result:

"gid";"wkt";"length";"gid"
4389;"MULTILINESTRING((-71.1951327440651 -30.5911350429583,-71.1957462426904
-30.5912128948402,-71.1957861853043 -30.591219747929,-71.1958400125164
-30.591211719682))";0.000713367403530106;4389
4603;"MULTILINESTRING((-71.1939954028678 -30.5921681162637,-71.1939834234752
-30.5922241673576,-71.1938231446269
-30.5925509466888))";0.000421286769021393;4603
4331;"MULTILINESTRING((-71.1950174992082 -30.5919506007811,-71.1950526139385
-30.5916919152203))";0.000261057969957178;4331
4608;"MULTILINESTRING((-71.1938231446269 -30.5925509466888,-71.1937648360013
-30.5926358138883))";0.00010296765211197;4608
RG

2009/2/3 Stephen Woodbridge <woodbri at swoodbridge.com>

> This may be cause because you need to check the direction of the line
> segments before you create a linestring to pass to the client. If you route
> is something like
>
> segment source target
>  1        1     3
>  2        4     3
>  3        7     4
> etc
>
> route (1,2,4,3,7,4) or 1,3,3,4) depending on how you assemble it is not
> going to make sense.
>
> Then segment 2 needs to be reversed so it goes from 3 to 4 and segment 3
> needs to be reverse also. so you get:
>
> route (1,3,4,7).
>
> Also this is not really a mapserver issues and you should probably pust
> this to the pgRouting list. It would alos help if you showed some of the
> intermediate results. When you show a image and the route is broken, most of
> us can look at the image and say "Yup, looks like the route is broken!" We
> do not see what data you got out of pgRouting, we do not know how that got
> passed to mapserver or OpenLayers, there are a lot of places that you can
> break things. We don't even know how data flows through your system or
> who/what is rendering the route part of the image.
>
> -Steve
>
> Valeria Muñoz wrote:
>
>> hi..
>>  I am back again with my problem pgrouting.. I followed a little tutorial
>> works perfectly with the shapefile from the example, but to use mine the
>> result is not expected, generating lines are not continuous, I think I
>> missing some coordinates or something to work with my shapefile.
>>  attached image.
>>  please help!!..
>>
>> 2009/1/19 Valeria Muñoz <valemunoz at gmail.com <mailto:valemunoz at gmail.com>>
>>
>>
>>    Hi
>>        I would like to implement the service "optimum path between 2
>>    points," can someone help me to be able to implement it?. The
>>    general idea is that a user picks a point A and point B and a
>>    display on the map the best route to get from point A to B.
>>        RG...
>>
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>> ------------------------------------------------------------------------
>>
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>
>
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