[pgrouting-users] Reg: Get nearest node in osm data

[Manikanta Kondeti]

Sorted it.

After small correction:
         select case when
st_line_locate_point(the_geom,st_setsrid(st_makepoint(67.338263167225,
-17.1189713223), 4326)) < 0.5 then (source) else (target) END AS node FROM
ways WHERE gid=400280;

Thank you,
Mani

On Wed, Jun 24, 2015 at 2:33 AM, Manikanta Kondeti <mani.iiit123 at gmail.com>
wrote:

> Hi Steve,
>
> Thanks a lot for your response.
>
> On Wed, Jun 24, 2015 at 1:55 AM, Stephen Woodbridge <
> woodbri at swoodbridge.com> wrote:
>
>> On 6/23/2015 3:56 PM, Manikanta Kondeti wrote:
>>
>>> Hi,
>>>
>>>   I am writing a small application to get the route on the map. I am
>>> using openlayers.js on client and pgrouting as a backend routing library
>>> for my project. When a click is triggered I get a lat, lon, and I have
>>> the osm data in postgres which is loaded using osm2pgrouting. I'll pass
>>> this lat,lon to server and  I have to find the nearest node id from this
>>> lat,lon. Can I query the database and get it done?  Help me out.
>>>
>>
>> Probably you want to do this in two steps:
>>
>> 1. find the nearest edge
>> 2. find the nearest node along the edge
>>
>> Anyway your queries will be something like:
>>
>
> This is working perfect and found the nearest edge.
>
>
>> -- get the closest edge
>> select * from edges where st_dwithin(geom, st_setsrid(st_makepoint(long,
>> lat), 4326), maxdist) order by st_distance(geom,
>> st_setsrid(st_makepoint(long, lat), 4326)) asc limit 1;
>>
>>
> This is giving me syntax error. I've added the screenshot
>
>
>> -- get closest node along edge
>> select case when st_line_locate_point(geom,st_setsrid(st_makepoint(long,
>> lat), 4326))  < 0.5 then source else target from edges edge_id=id
>>
>>
>>
>>
> This is not giving me any nearest nodes. I've this screenshot as well.
>
>
>> -- or search to just get the closest node
>> select * from nodes where st_dwithin(geom, st_setsrid(st_makepoint(long,
>> lat), 4326), maxdist) order by st_distance(geom,
>> st_setsrid(st_makepoint(long, lat), 4326)) asc limit 1;
>>
>>
>> where:
>>
>> maxdist - maximum distance to search for geometries in db units probably
>> degrees
>>
>> long, lat - values for the location in question
>>
>> id - is the id of the closest edge found in the first query
>>
>
>
>
> Let me know if I miss something.
>
> Thanks,
> Mani
>
>
>
>> _______________________________________________
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>> http://lists.osgeo.org/mailman/listinfo/pgrouting-users
>>
>
>
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