[Gmsh] Boundary command

[David Colignon]

If you apply the Boundary command to a volume, like in my example

 >add the following to the end of t2.geo :
 >
 >     aaaa[] = Boundary { Volume {119}; };
 >     For ii In { 0 : (#aaaa[] -1) }
 >       Printf("boundary number %g = %g", ii, aaaa[ii]);
 >     EndFor

you will get a list/arrray of the surfaces delimiting the volume. If you apply it to a surface, you will get the list of 
the lines, and so on.

It is mainly used in complex script/geometries build with extrusions where you want an automated way of getting the 
boundary of a volume/surface

Dave



Mike B. wrote:
> HI David,
> 
> Thanks for replying. I am familiar with the description in the manual.
> What kind of entity does `Boundary' return? an array of surfaces? what 
> is the use of the command?.
> 
> Thanks,
> Mike.
> 
> 
> --- On *Thu, 7/30/09, David Colignon /<David.Colignon at ulg.ac.be>/* wrote:
> 
> 
>     From: David Colignon <David.Colignon at ulg.ac.be>
>     Subject: Re: [Gmsh] Boundary command
>     To: "Mike B." <mb78aa at yahoo.com>
>     Cc: "Gmsh mai. lis." <gmsh at geuz.org>
>     Date: Thursday, July 30, 2009, 5:51 PM
> 
>     Hi Mike,
> 
>     http://www.geuz.org/gmsh/doc/texinfo/gmsh-full.html#SEC37
>     <http://www.geuz..org/gmsh/doc/texinfo/gmsh-full.html#SEC37>
> 
>     Boundary { transform-list }
>         (Not a transformation per-se.) Returns the boundary of the
>     elementary entities in transform-list.
> 
>     with
> 
>     transform-list:
>       Point | Line | Surface | Volume { expression-list }; ... |
>       Duplicata { Point | Line | Surface | Volume { expression-list };
>     ... } |
>       transform
> 
> 
> 
>     for example, you can add the following to the end of t2.geo :
> 
> 
>     aaaa[] = Boundary { Volume {119}; };
> 
>     For ii In { 0 : (#aaaa[] -1) }
> 
>       Printf("boundary number %g = %g", ii, aaaa[ii]);
> 
>     EndFor
> 
> 
> 
>     Cheers,
> 
>     Dave
> 
>     -- David Colignon, Ph.D.
>     Collaborateur Logistique du F.R.S.-FNRS
>     CÉCI - Consortium des Équipements de Calcul Intensif
>     ACE - Applied & Computational Electromagnetics
>     Sart-Tilman B28
>     Université de Liège
>     4000 Liège - BELGIQUE
>     Tél: +32 (0)4 366 37 32
>     Fax: +32 (0)4 366 29 10
>     WWW:    http://hpc.montefiore.ulg.ac.be/
>     Agenda:
>     http://www.google.com/calendar/embed?src=david.colignon%40gmail.com
> 
> 
> 
>     Mike B. wrote:
>      > Dear All,
>      >
>      > Can someone please clarify what does the `Boundary' command do,
>     what values it returns and how to use it?. I couldn't find any
>     examples in the tutorials or demos.
>      >
>      > Thanks,
>      > Mike.
>      >
>      >
>      >
>      >
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