select st_isvalid(a.p), st_isvalid(b.q) from (select st_geomfromtext('LINESTRINGZ(0 0 0, 1 0 0)')as p) as a, (select st_geomfromtext('LINESTRINGZ(0 0 0, 0.00000001 0 10000)') as q) as b;
st_isvalid (a.p) st_isvalid(b.q) t t LINESTRING(s) have an work obligation to go somewhere, even if a very small distance, and .5D doesn't constitute enough of a dimension to have gone somewhere as strk points out. Chris > Date: Mon, 22 Oct 2012 09:40:46 -0700 > From: ps.ti...@yahoo.com > To: postgis-users@postgis.refractions.net > Subject: [postgis-users] LinestringZ not valid > > Hello, > > I've tried to make a linestring with z value as below > > select st_isvalid(a.p), st_isvalid(b.q) > from (select st_geomfromtext ('LINESTRING Z(0 0 0, 1 0 0)') as p) as a, > (select st_geomfromtext('LINESTRING Z(0 0 0, 0 0 1)') as q) as b > > the result shows that linestring from table b is not valid,,it's caused too > few points.. > is it impossible to make linestring (0 0 0, 0 0 1) ? how to make it valid? > > thanks.. > > --t > > > > -- > View this message in context: > http://postgis.17.n6.nabble.com/LinestringZ-not-valid-tp5000695.html > Sent from the PostGIS - User mailing list archive at Nabble.com. > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users