Thank you, Sandro, yes, I clearly understand this, but all my contours are CLOSED and NONE of them intersects each other. many of them contain each other. actually, they are like isobars on synoptic map,
please, see for ex http://1.bp.blogspot.com/_a1AVUIK5Er8/S27QJhQijOI/AAAAAAAAI88/NUJE11Me6n4/s1600-h/Synoptic+Chart.jpg _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
