[postgis-users] Intersection errors

[Sean M. Montague]

It's a hole.  It should be valid...I think.  What about islands in a
lake?  The only time I have a problem with them is when I intersect one.

-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Paul
Ramsey
Sent: Tuesday, June 07, 2005 11:35 AM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] Intersection errors

It's not valid, because legal multipolygons do not have parts that 
interact. Your multipolygon has two parts and one is completely 
contained in the other. No cookie for you!

Paul

Sean M. Montague wrote:
> Correct, below is the insert statement I construct from AV 3 using
> Avenue.  I'm not sure about the isvalid.  Is that what you get when
> trying to insert it?  Thanks.
> 
> Sean
> 
> INSERT INTO "test_02" ("objectid","name","layer","the_geom") VALUES
> ('3','3','3',GeometryFromText('MULTIPOLYGON(((-244339 1210399, -244339
> 1541250, 21058 1541250, 21058 1210399, -244339 1210399)),((-39283
> 1521307, -57692 1518238, -64340 1511591, -62805 1497784, -54112
1494716,
> -45931 1494716, -40306 1494204, -38260 1493693, -34681 1482443, -42862
> 1471705, -50021 1460966, -51044 1448182, -41840 1437955, -27522
1431307,
> -8601 1422614, 603 1409318, 92 1392955, -13715 1377103, -46953
1370455,
> -68942 1365341, -91442 1342841, -91442 1309092, -81726 1303467, -2976
> 1329546, 13899 1358182, 14921 1431818, -7067 1513125, -39283
> 1521307)))',32767))
> 
> 
> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net
> [mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of
> Darren Houston
> Sent: Monday, June 06, 2005 8:30 PM
> To: PostGIS Users Discussion
> Subject: Re: [postgis-users] Intersection errors
> 
> Hi Sean,
> 
> I'm correct in assuming the multipolygon posted is the geometry at 
> layer=3? I received a false isvalid on that multipolygon.
> 
> 'POSTGIS="1.0.1" GEOS="3.0.0" PROJ="Rel. 4.4.9, 29 Oct 2004" USE_STATS

> DBPROC="0.3.0" RELPROC="0.3.0"'
> 
> I'm in a rush, but I promise to look at it more tomorrow.
> 
> Darren H.
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users