[postgis-users] exterior rings in multipolygons

[Sandro Santilli]

On Tue, Jul 26, 2011 at 09:47:23AM -0500, Mr. Puneet Kishor wrote:
> 
> On Jul 26, 2011, at 9:34 AM, Sandro Santilli wrote:
> 
> > On Tue, Jul 26, 2011 at 09:31:50AM -0500, Mr. Puneet Kishor wrote:
> > 
> >> 	ERROR:  function st_interiorringn(geometry) does not exist
> > 
> > Check your parens, the call above is missing a parameter (ring number).
> > 
> 
> That is a bit embarrassing. Yes, I had missed out on giving the ring number. However, still no luck --
> 
> SELECT objectid, 
> 	ST_NRings(the_geom) num_of_rings, 
> 	ST_NumInteriorRings(the_geom) num_of_int_rings, 
> 	ST_NumPoints(ST_ExteriorRing(ST_GeometryN(the_geom,1))) num_of_points_ext_ring,
> 	ST_AsText(the_geom) wkt_feature, 
> 	ST_AsText(ST_MakePolygon(ST_ExteriorRing(ST_GeometryN(the_geom, 1)))) wkt_ext_ring,
> 	ST_AsText(ST_MakePolygon(ST_InteriorRingN(ST_GeometryN(the_geom, 2), 2))) wkt_int_ring_a,
> 	ST_AsText(ST_MakePolygon(ST_GeometryN(the_geom, 2))) wkt_int_ring_b
> FROM table 
> WHERE objectid = 280;
> 
> objectid: 280;
> num_of_rings: 4;
> num_of_int_rings: 3;
> num_of_points_ext_ring: 496;
> wkt_feature: "MULTIPOLYGON(((<1>),(<2>),(<3>),(<4>))";
> wkt_ext_ring: "POLYGON((<1>))";
> wkt_int_ring_a: "";
> wkt_int_ring_b: ""
> 
> As you see, I tried to get the interior ring "n" two different ways. Not getting anywhere.

Write down a matrix of all combinations you tried.
Use real paper, and pencil.
Publish a scanned version.

--strk;

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