[OSM-talk] Parking symbols: YUCK!

[Lester Caine]

Robert (Jamie) Munro wrote:
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> Lester Caine wrote:
> | Mark Williams wrote:
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> |> Lester Caine wrote:
> |>> J.D. Schmidt wrote:
> |>>> Lester Caine skrev:
> |> [big snip]
> |>
> |>> LOGICALLY - there should never have been a problem created. A POI
> element
> |>> should consist of a single entity which may have additional area
> information.
> |>> Even those tags that are currently only defined as 'node' in many
> cases WILL
> |>> be expanded to include area information at some point. So PLEASE can
> we have
> |>> some sensible method of identifying PAIRS of tags so we can THEN
> decide what
> |>> to do with them !!!
> |>>
> |> Is this not a job for relations? If the pair were related, then we have
> |> no problem?
> |
> | Correct - but how do you identify elements uniquely so you can create the
> | relation?
> 
> I'm not quite sure what you mean, but to try to bring this back onto
> topic, if you mean "How do we find amenity=parking nodes that are
> duplicates of areas?" the answer is that we find all the nodes inside
> areas. If there are any that are just outside, we will miss them, whici
> is annoying, but not the end of the world. In order to find them, we can
> use a Simple postGIS query as suggested by Dave Stubbs (which I have
> attempted to reformat a bit):
> 
> select p.osm_id
> ~  from planet_osm_point as p,
> ~       planet_osm_polygon as a
> where a.osm_id!=p.osm_id
> ~  and a.osm_id in (
> ~    select a.osm_id from planet_osm_point as p, planet_osm_polygon as a
> ~    where a.amenity='parking'
> ~      and p.amenity='parking'
> ~      and a.way && p.way
> ~      and intersects(a.way, p.way)
> ~    group by a.osm_id
> ~    having count(p.osm_id) > 1
> ~  )
> ~  and p.amenity='parking'
> ~  and a.way && p.way
> ~  and intersects(a.way,p.way);

This will only work for the specific case where there is a single matching 
node that goes with the area, and I believe it will be time intensive when 
processing a large area. I don't believe there is any mechanism to create 
a.osm_id = p.osm_id - these will always have different id's? If they HAD 
matching id's them there would not be a problem.

See proposed good practice ideas for fast consistent solution.

-- 
Lester Caine - G8HFL
-----------------------------
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