[OSM-dev] osm2pgsql / postgis precision

[Etienne Chové]

Hi,

Coordinates are rounded during initial import.

*Try to import (osm2pgsql -c -m -s)*

<osm version="0.6">
   <node id="1" version="1" lat="0" lon="0"/>
   <node id="2" version="1" lat="1.123456789" lon="2.123456789"/>
   <way id="3">
     <tag k="highway" v="primary"/>
     <nd ref="1"/>
     <nd ref="2"/>
   </way>
</osm>

*and then to import (osm2pgsql -a -m -s)*

<osmChange version="0.6">
   <create>
     <way id="4">
       <tag k="highway" v="primary"/>
       <nd ref="1"/>
       <nd ref="2"/>
     </way>
   </create>
</osmChange>

*you'll get two differerent ways*

gis=> SELECT osm_id, astext(way) from test_import_roads;
  osm_id |                       astext
--------+-----------------------------------------------------
       3 | LINESTRING(0 -7e-10,236382.12 125070.65)
       4 | LINESTRING(0 -7e-10,236382.128473 125070.652348178)

The difference is not really significant but postgis says polygons are 
olvelapping each other while they have just a common boundary.

Should I raise a bugreport ?

-- 
Etienne