[postgis-tickets] [PostGIS] #2869: St_Centroid doesn't work on curved geom

[PostGIS]

#2869: St_Centroid doesn't work on curved geom
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 Reporter:  remic        |       Owner:  pramsey
     Type:  enhancement  |      Status:  new    
 Priority:  medium       |   Milestone:         
Component:  postgis      |     Version:  2.1.x  
 Keywords:               |  
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Comment(by remic):

 Here is a wrapper ,
 totally non optimal

 DROP FUNCTION IF EXISTS public.rc_centroid(  igeom GEOMETRY);
 CREATE OR REPLACE FUNCTION public.rc_centroid(
         igeom GEOMETRY
         )  RETURNS GEOMETRY AS
 $BODY$
         -- at brief : this function is a thin wrapper around st_centroid than
 enable to use it with circularstring
         -- at param : a geom whose centroid we want
         -- at return : teh centroid

                 DECLARE
                 BEGIN

                         --RAISE EXCEPTION 'hello,  % , %',
 st_astext(igeom), st_geometrytype(igeom) ;

                         IF ST_GeometryType(igeom) ILIKE '%CircularString%'
                         THEN
                                 --special case, we cast the circularstring
 to multipoint

                                 RETURN ST_Centroid(ST_Collect(dmp.geom))
                                 FROM ST_DumpPoints(igeom) as dmp
                                 WHERE dmp.path =ARRAY[1] OR dmp.path
 =ARRAY[3];
                         END IF ; --cicular string

                         RETURN ST_Centroid(igeom) ;
                 END ;
         --test
         --SELECT ST_AsText(rc_centroid(geom ))
         --FROM st_geomfromtext('circularstring(0 0 , 1 1, 2 0)') as geom ;
 $BODY$
  LANGUAGE plpgsql IMMUTABLE STRICT;

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2869#comment:2>
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