<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial, helvetica, sans-serif;font-size:10pt"><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;">I just implemented this incase anyone wants it. Yes its slow, yes it's stupid and assumes all data coming in is good. But it will work for my application.<br><br>CREATE FUNCTION Intersection(in_polys geometry) RETURNS geometry AS $$<br>DECLARE<br>intersection_result geometry := GeometryN(in_polys, 1);<br>BEGIN<br> FOR i IN 2..NumGeometries(in_polys) LOOP<br> intersection_result := Intersection(intersection_result,GeometryN(in_polys,i));<br> END LOOP;<br> RETURN intersection_result;<br>END;<br>$$ LANGUAGE plpgsql;<br><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">----- Original Message ----<br>From: Curtis W. Ruck
<ruckc@yahoo.com><br>To: postgis-users@postgis.refractions.net<br>Sent: Wednesday, October 4, 2006 11:04:21 PM<br>Subject: [postgis-users] Aggregate Intersection?<br><br><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><div>Does anyone know of a way of chaining functions to do an aggregate intersection? I have a table where i have multiple polygons and i need a intersection(geometry set) function.<br><br>Could i possibly write my own in plpgsql by getting the geometry set and looping through the polygons and more or less recursivly return Intersection(the_geom[3],Intersection(the_geom[2],Intersection(the_geom[0],the_geom[1])) ?<br><br>Curtis<br></div></div><div>_______________________________________________<br>postgis-users mailing list<br>postgis-users@postgis.refractions.net<br><a target="_blank"
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