Not sure what you are trying to do, but one of the affine functions like ST_Translate may be what you are looking for. http://www.postgis.org/documentation/manual-1.5SVN/ST_Translate.html That will move all the points in the geometry a specified amount in x,y,z Leo
_____ From: [email protected] [mailto:[email protected]] On Behalf Of ZHANGAIGUO Sent: Wednesday, November 11, 2009 11:50 AM To: [email protected] Subject: [postgis-users] Can I replace all the x and y coordinates of a geometry using PostGIS, Thank you! Hello Postgis-users: I am a student in Fuzhou University, China. In using PostGIS, I encountered a problem as fellows: How can I replace all the x and y coordinates of a geometry? The geometry may be point, multipoint, linestring, multilinestring, and so on. I have tried to use the way as fellows: CREATE OR REPLACE FUNCTION aigo_coord_offset_basicframe2(geometry, double precision, double precision) RETURNS geometry AS $BODY$ declare i integer; compress geometry; geom1 geometry; begin i:=1; geom1:=ST_GeomFromText('LINESTRING(0 0, 0.0001 0.0001)',21460); while i<= ST_NumPoints($1) loop geom1:=ST_AddPoint(geom1,ST_MakePoint(int2(ST_X(ST_PointN($1,i))-$2),int2(ST _Y(ST_PointN($1,i))-$3))); i:=i+1; end loop; geom1:=ST_RemovePoint(geom1,0); geom1:=ST_RemovePoint(geom1,0); compress:=geom1; return compress; end $BODY$ LANGUAGE 'plpgsql' VOLATILE COST 100; ALTER FUNCTION aigo_coord_offset_basicframe2(geometry, double precision, double precision) OWNER TO post; The way above is just applied to LINESTRING geometry type, and it is inefficient. Are there any other solutions to accomplish it? Thank you! Sincerely Yours! ZHANG Aiguo _____ Messe nger保护盾2.0，更安全可靠的Messenger聊天！ 现在就下载！ <http://im.live.cn/safe/>
_______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
