[postgis-users] ERROR: GEOS difference() threw an error!

[Andreas Laggner]

Andreas Laggner schrieb:
> can someone tell me what causes this Error?
>
> ERROR: GEOS difference() threw an error!
> SQL Status:XX000
More Informations from the postgresql Logfile:
NOTICE:  TopologyException: found non-noded intersection between 
3.81546e+06 5.4495e+06, 3.81559e+06 5.44944e+06 and 3.81546e+06 
5.4495e+06, 3.81551e+06 5.44948e+06 3.81551e+06 5.44948e+06
ERROR:  GEOS difference() threw an error!

>
> the query:
> INSERT INTO test_natura_full
> SELECT 
> ffh_singlerep.ffh_name,ffh_singlerep.ffh_land,ffh_singlerep.ffh,ffh_singlerep.ffh_id, 
>
>    null as spa_name,null as spa_land,null as spa,null as spa_id,
>    ST_Difference(ffh_singlerep.the_geom, test_natura_full.the_geom) As 
> the_geom
> FROM ffh_singlerep INNER JOIN (SELECT ffh_id, ST_union(the_geom) As 
> the_geom
>    FROM test_natura_full GROUP BY ffh_id) As test_natura_full ON 
> ffh_singlerep.ffh_id = test_natura_full.ffh_id
>    AND ST_Intersects(ffh_singlerep.the_geom, test_natura_full.the_geom)
> WHERE ST_IsEmpty(ST_Difference(ffh_singlerep.the_geom, 
> test_natura_full.the_geom)) = false
> UNION
> SELECT null as ffh_name,null as ffh_land,null as ffh,null as ffh_id,
>    
> spa_singlerep.spa_name,spa_singlerep.spa_land,spa_singlerep.spa,spa_singlerep.spa_id, 
>
>    ST_Difference(spa_singlerep.the_geom, test_natura_full.the_geom) As 
> the_geom
> FROM spa_singlerep INNER JOIN  (SELECT spa_id, ST_union(the_geom) As 
> the_geom
>    FROM test_natura_full GROUP BY spa_id) As test_natura_full ON 
> spa_singlerep.spa_id = test_natura_full.spa_id
>    AND ST_Intersects(spa_singlerep.the_geom,test_natura_full.the_geom)
> WHERE ST_IsEmpty(ST_Difference(spa_singlerep.the_geom, 
> test_natura_full.the_geom)) = false;
>
>
> I had no problems with a small dataset (15 and 4 polygons), here i 
> have 28000 and 1500 rows. All geometries are valid and singlepart 
> Polygons.
>
> Cheers      Andreas
>
>


-- 
Dipl. Geoökologe Andreas Laggner
Institut für Ländliche Räume (LR)
Bundesforschungsanstalt für Landwirtschaft (FAL)

Institute of Rural Studies
Federal Agricultural Research Centre (FAL)

Bundesallee 50
D-38116 Braunschweig

Tel.: (+49) (0)531 596 5515
Fax: (+49) (0)531 596 5599
E-mail: andreas.laggner at fal.de
Homepage: http://www.lr.fal.de/