[postgis-users] ST_snap doesn't snap within the tolerance

[Astrid Bjørnerød]

I want some polygons (with attribute artype=21) to snap into some neighbor-polygon. I have set the tolerance to 5m.
Put not all of the polygons in the result has been snapping, the gap is under the tolerance.
The sql:
create table test_ar5jm.snipsnap AS SELECT p1.jmsign,ST_Union(ST_Buffer(ST_Snap(p1.geo,p2.geo, 5),0)) as geo
FROM test_ar5jm.temp_aij_flate
AS p1 CROSS JOIN test_ar5jm.temp_aij_flate As p2
WHERE p1.artype = 21
GROUP BY p1.jmsign;

Figures from QGis before snapping and after snapping in attachedment.

Vennlig hilsen
Astrid Bjørnerød

Seksjon Geomatikk
-------------------------------------------
Norsk institutt for skog og landskap
Pb 115, NO-1431 Ås
T (+47) 64 94 96 96
F (+47) 64 94 80 01
-------------------------------------------
www.skogoglandskap.no<http://www.skogoglandskap.no>
-------------------------------------------

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120711/bf7d3bfc/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: after_snap.jpg
Type: image/jpeg
Size: 37621 bytes
Desc: after_snap.jpg
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120711/bf7d3bfc/attachment.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: before_snap.jpg
Type: image/jpeg
Size: 41954 bytes
Desc: before_snap.jpg
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120711/bf7d3bfc/attachment-0001.jpg>