different results for ST_Relate with 3 parameters compared to those for ST_Relate with 2 parameters
Antonio Valanzano <[email protected]> Wed, 15 Oct 2025 18:22:05 +0200
| Newsgroups | gmane.comp.gis.postgis |
|---|---|
| Message-ID | <CANV1FQYH0T9im=NTOUEYic+V2VLkyet-L3ZvCADVkLf0n+DtqQ@mail.gmail.com> |
I am following the "Introduction to PostGIS " tutorial at https://postgis.net/workshops/postgis-intro/ and for chapter 26 "Dimensionally Extended 9-Intersection Model" I am trying to replicate the examples. If I use the two different versions of ST_Relate I do not obtain the same result SELECT d.id, ST_Relate(d.geom, l.geom) as patternMatrix FROM docks as d, lakes as l WHERE ST_Relate(d.geom, l.geom, '1FF00F212') = true; -- 1 row "id" "patternmatrix" 1 "1FF00F212" SELECT d.id, ST_Relate(d.geom, l.geom) as patternMatrix FROM docks as d, lakes as l WHERE ST_Relate(d.geom, l.geom) = '1FF00F212'; -- 2 rows "id" "patternmatrix" 1 "1FF00F212" 2 "1FF00F212" Could someone give me an explanation of such a difference ?