[OSM-dev] shortest streets
osm at stephans-server.de
Thu Sep 17 01:01:10 BST 2009
> Stephan Knauss wrote:
>> something like this?
>> select osm_id, st_length(way) as length from planet_osm_roads order by
>> length asc limit 10
> Something, but not exactly that. ST_Length(way) is in projected meters,
> which varies with latitude.
So could you specify a better projection that would be equidistant? The
data here uses 900913.
Would 4326 be equidistant?
Then it could read like this:
select osm_id, length(st_transform(way,4326)) as length from
planet_osm_roads order by length asc limit 10
Is there a difference between st_length() and length()? They both return
the same values (at least for 900913).
Postgis manual has a similar query to sum up the length of ways. Why is
it working there? Different projection?
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