[postgis-users] FW: Support in ST_ConvexHull syntax

[Gery .]

you're a genius man, my mistake again, my input is 3D point, so, the polygon should be 3D also, thanks man.


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> Date: Thu, 20 Oct 2011 14:56:24 +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 12:09:01PM +0000, Gery . wrote:
> >
> >
> > or should be 3 in my table! Bingo! after running: "select st_ndims(st_convexhull(st_collect(geom)) from splitbeam_point;" I got 3 instead of 2, so I put this3 into my table and ready! that did the trick. Now I'm wondering why this has to be 3, I mean, this is a 2D polygon, I think I'll realize that after keeping reading.
> >
> > Thanks again Sandro, you were very helpful,
>
> You could have forced your output to 2d using ST_Force_2d,
> if that's what you needed.
>
> Why you get a 3d convexhull from a 2d input I don't know.
> Are you sure your input geometries are 2d ?
> Check st_ndims against all stages: geom, st_collect(geom)
>
> --strk;
>
> () Free GIS & Flash consultant/developer
> /\ http://strk.keybit.net/services.html