[postgis-users] FW: Support in ST_ConvexHull syntax

[Gery .]

Now I'm trying to form the polygon but with ST_ConcaveHull and 80% but this error message appears:

***
ERROR:  function st_concavehull(geometry, numeric) does not exist
LINE 1: INSERT INTO splitbeam_area_polygon (geom) SELECT ST_ConcaveH...
                                                         ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
***

I have no problems with ConvexHull, it created the polygon with "INSERT INTO splitbeam_area_polygon (geom) SELECT ST_ConvexHull(ST_Collect(geom)) AS geom FROM splitbeam_point;"

But this gives the above error: INSERT INTO splitbeam_area_polygon (geom) SELECT ST_ConcaveHull(ST_Collect(geom), 0.80) AS geom FROM splitbeam_point;

I'm using PostGis 1.53 and PostgreSQL 8.4.8.

Any hint is very grateful,

Thanks in advance,

Gery


----------------------------------------
> Date: Thu, 20 Oct 2011 11:53:27 +0200
> From: strk at keybit.net
> To: gamejihou at hotmail.com
> CC: postgis-users at postgis.refractions.net
> Subject: Re: [postgis-users] FW: Support in ST_ConvexHull syntax
>
> On Thu, Oct 20, 2011 at 09:26:48AM +0000, Gery . wrote:
>
> > mop=# \d unaprueba
> >    Table "public.unaprueba"
> >  Column |   Type   | Modifiers
> > --------+----------+-----------
> >  id     | smallint |
> >  geom   | geometry |
> > Indexes:
> >     "unaprueba_geom" gist (geom)
> > Check constraints:
> >     "enforce_dims_geom" CHECK (st_ndims(geom) = 2)
> >     "enforce_geotype_geom" CHECK (geometrytype(geom) = 'POLYGON'::text OR geom IS NULL)
> >     "enforce_srid_geom" CHECK (st_srid(geom) = 4326)
>
> ...
>
> > mop=# insert into unaprueba (geom) SELECT st_convexhull(st_collect(geom)) as geom FROM splitbeam_point ;
> > ERROR:  new row for relation "unaprueba" violates check constraint "enforce_dims_geom"
> >
> > where could be the problem?
>
> << The new row violates check constraint "enforce_dims_geom" >>
>
> Compare the above message with the output of \d above:
>
> > Check constraints:
> >     "enforce_dims_geom" CHECK (st_ndims(geom) = 2)
> ^^^^^^^^^^^^^^^^^^^
> >     "enforce_geotype_geom" CHECK (geometrytype(geom) = 'POLYGON'::text OR geom IS NULL)
>
> Check the output of:
>
> st_ndims(st_convexhull(st_collect(geom)) from splitbeam_point;
>
> Must be 2 ...
>
> --strk;
>
> () Free GIS & Flash consultant/developer
> /\ http://strk.keybit.net/services.html