CGAL users discussion list

[Monique Teillaud <>]

still, it is a bit strange that Regular_triangulation_cell_base_3
- does not provide weighted_circumcenter()
- but it provides circumcenter() because it inherits from 
Triangulation_cell_base_3

similarly, concept RegularTriangulationCellBase_3
- does not require weighted_circumcenter()
- but requires circumcenter() because it refines TriangulationCellBase_3

At least, we could add weighted_circumcenter() in Regular_*.

Le 08/02/13 10:03, Sebastien Loriot (GeometryFactory) a écrit :
> It's an inheritance problem, Weighted_point inherits from the point
> which is documented here:
> http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_2_ref/Class_Weighted_point.html
>
>
> I'm afraid, there is not much we can do about it.
>
> Sebastien.
>
> On 02/08/2013 10:00 AM, Tom Dreyfus wrote:
> > Hi,
> >
> > thank you for the answer.
> >
> > However, I am not sure that it is normal that the method circumcenter()
> > returns the (not weighted) circumcenter associated to a Cell in the
> > Regular_triangulation. The circumcenter is associated to a set of
> > points, and the weighted circumcenter is associated to a set of weighted
> > points: the possiblity to use the not weighted circumcenter in the
> > regular triangulation may be confusing and may lead to errors. Or at
> > least, it should be mentionned somewhere in the documentation.
> >
> > Tom.
> >
> > ------------------------------------------------------------------------
> >
> >     *De: *"Fernando de Goes" 
> > <>
> >     *À: 
> > *
> >     *Cc: 
> > *
> >     *Envoyé: *Jeudi 7 Février 2013 18:14:59
> >     *Objet: *Re: [cgal-discuss] bug: circumcenter with
> >     Regular_triangulation_3
> >
> >     hi Tom,
> >
> >     Regular_triangulation is a weighted Delaunay triangulation and its
> >     dual is a weighted circumcenter, ie, the circumcenter plus a
> >     displacement that depends on the vertex weights.
> >     When the weights of the vertices of a triangle have different values
> >     (and that's the case in your file bug.txt), the dual will be always
> >     different than the circumcenter.
> >     When all the weights are the same, the weighted Delaunay
> >     triangulation reduces to a Delaunay triangulation and then the dual
> >     coincides with the circumcenter.
> >
> >
> >     On Thu, Feb 7, 2013 at 9:07 AM, Tom Dreyfus 
> > <
> >     
> > <mailto:>>
> >  wrote:
> >
> >         Hello,
> >
> >         The methods Regular_triangulation_3::dual(Cell_handle) and
> >         Cell::circumcenter(void) do not return the same point.
> >
> >         I join a short example.
> >
> >         Tom.
> >
> >
> >
> >
> >     --
> >     Fernando de Goes


--
Monique Teillaud
http://www.inria.fr/sophia/members/Monique.Teillaud/
INRIA Sophia Antipolis - Méditerranée
Institut National de Recherche en Informatique et Automatique