[postgis-users] intersection doesn't seem to intersect back w/ original geom

[Charlton Galvarino]

Oddly doing an ST_Distance from a to b or from b to c = 0.  So I guess I can get by w/ running that test.  But I'm still perflutzed why it doesn't Intersect.

>-----Original Message-----
>From: postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-
>bounces at lists.osgeo.org] On Behalf Of Charlton Galvarino
>Sent: Tuesday, January 22, 2013 9:24 AM
>To: PostGIS Users (postgis-users at postgis.refractions.net)
>Subject: [postgis-users] intersection doesn't seem to intersect back w/
>original geom
>
>Hi, all.  I'm completely stumped and hope the answer is right in front of my
>face.
>
>The pink ls.
>a.geom =
>0102000020BA08000002000000ED7E57CC2CDF2F41BCE00145EF9F29414DABCE8
>596DE2F41F40B15A36C9F2941
>
>The blue ls.
>b.geom =
>0105000020BA0800000100000001020000000A0000003E35FDD6D4DE2F413858F6
>0E92A12941003235ED84DE2F410075ECAFEF9F294100F99BA4C2DE2F41000B8A3
>7399E294180E6B00C42DF2F410049DDE92E9C2941805D5940DDDF2F41009D30FC
>C79A2941004F9FEB5CE02F41808734555298294100D58EBEB6E02F41005398EA9B
>9629410099A09767E02F4100CE6014A99529418024290838DF2F41008CA543DF93
>2941801DD29CF2DD2F41804F933046932941
>
>Their intersection (yellow dot) computed from the above two geoms.
>c.geom = 0101000020BA08000075E19F4797DE2F415AA1904B6D9F2941
>
>My SRID's are all the same.
>
>Why in the **** doesn't the final intersection ST_Intersects() w/ either
>original linestring?!  Precision issue?  I'm nuts issue?
>
>TIA.
>
>
>
>
>
>Charlton Galvarino
>1 (803) 233-6205 : voice
>1 (803) 223-9579 :   fax
>charlton at 2creek.com
>
>P.O. Box 50960
>Columbia, SC 29250