[OSM-dev] Osmosis Bug Report: Node TileIDs Incorrect

Christopher Schmidt crschmidt at metacarta.com
Wed Apr 23 04:17:23 BST 2008


On Wed, Apr 23, 2008 at 09:07:50AM +1000, Brett Henderson wrote:
> Oh crap, apparently I didn't test that bit.  I never did get the mysql 
> extensions installed to compare against.
> 
> I doubt if I'll get to this for a few days, bit run off my feet at the 
> moment.  I don't know what the problem is but perhaps Java is doing some 
> unexpected rounding along the way.

That's essentially what I figured. For now, anyone using osmosis to
populate a mysql database should use the update statement at the end of
this post if they want to get accurate results back from API map/bbox
queries.

> Christopher Schmidt wrote:
> > Osmosis creates incorrect tile IDs for some nodes when reading from XML
> > and inserting into MySQL.
> >
> > For the node:
> >
> > <node id="21619242" lat="51.4781325" lon="-0.1474929" user="Osmosis
> >     System User" visible="true" timestamp="2007-11-11T09:11:14-05:00">
> >
> > Osmosis generates:
> >
> > 2062265655
> >
> > tile_for_point generates:
> >
> > 16:35:51 < crschmidt> select tile_for_point(514781325,-01474929);
> > 16:35:56 < crschmidt> | tile_for_point(514781325,-01474929) |
> > 16:35:56 < crschmidt> +-------------------------------------+
> > 16:35:56 < crschmidt> |                          2062265654 | 
> >
> > Updating a table with 115000 nodes in it says:
> >
> > mysql> update current_nodes set tile=tile_for_point(latitude,
> >                                                     longitude);
> > Query OK, 103333 rows affected (11.41 sec)
> > Rows matched: 115692  Changed: 103333  Warnings: 0
> >
> > Which means, I guess, that 12000 (~10%) ended up okay, and everything
> > else was (presumably) off by one.
> >
> > Regards,
> >   
> 
> 
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-- 
Christopher Schmidt
MetaCarta




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