OK, I'll ask this then. What's the best way to get this: select ST_Extent3d(geometry_column) from my_table;
Into EWKB w/o losing the Z (or M) coordinate? Doing: select ST_AsEWKB(ST_Extent3D(geometry_column)) from my_table; unfortunately falls prey to the issue we're discussing. Thanks. -Abe On Sun, Jan 10, 2010 at 10:53 PM, Paragon Corporation <[email protected]> wrote: > As a side note. ST_Zmax doesn't exist for geometries. It works because > geometries can be autocast to boxes. > > See matrix > http://www.postgis.org/documentation/manual-svn/ch08.html#PostGIS_TypeFuncti > onMatrix > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Paragon > Corporation > Sent: Sunday, January 10, 2010 10:50 PM > To: 'PostGIS Users Discussion' > Subject: Re: [postgis-users] Bug dropping the Z coordinate? > > Abe, > > It seems we are flattening the box3d geometry in to a 2D polygon always > instead of as a 3D/2.5D polygon. > I'm not sure it's a bug though, because I think a box3d is an invalid 2.5/3D > polygon if you were to construct it. > > Can you envision it? > > Paul, Mark or Kevin might have a better clue, but I think it's at best an > ambiguous 3D polygon and that is the problem. A box3d isn't really a 3D box, > its more just a coordinate bounding thing. > > Hope that helps, > Regina > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Abram > Gillespie > Sent: Sunday, January 10, 2010 4:31 PM > To: PostGIS Users Discussion > Subject: [postgis-users] Bug dropping the Z coordinate? > > Is this a bug? > > select ST_ZMax('BOX3D(0 0 0,0 0 1)'::box3d); > > versus > > select ST_ZMax(ST_GeomFromEWKB(ST_AsEWKB('BOX3D(0 0 0,0 0 1)'::box3d))); > > The first query returns "1" as expected but the second returns "0" as > unexpected. > > I'm trying to add Z/M support to zigGIS and this is show-stopping me. > Any work-arounds if this is a bug? Also, I'll be happy to report the bug if > so. > > Thanks. > -Abe > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
