[Gmsh] About tags.

Christophe Geuzaine cgeuzaine at ulg.ac.be
Fri Jun 22 10:03:31 CEST 2007

Cécile Giorla wrote:
> Hi,
> I have a question about how we can tag elements in GMSH.
> In my case, I create surface elements with extrusion (in z direction) 
> from various ground surfaces (creating buildings).
> So I can not control the number of the elementary geometrical entity for 
> this surfaces.

Since Gmsh 2.0.7 you can retrieve the "lateral" surface ids from the 
list returned by extrusion commands. Would that solve the problem?

> I control the number of the physical entity by assigning the same number 
> for all the elements of the ground and the surfaces created. (the ground 
> AND the buildings' surfaces then are a unique surface).
> But I need to keep an information about from which ground surface a 
> building is created. I know GMSH has information about mesh partition, 
> but how can I assign this number?
> Or maybe there is a way in GMSH to assign user defined tag when we 
> create elements (other than the physical number)?
> Thank you.
> Cecile Giorla.

I'm not sure I understand your question... Couldn't you just label the 
surfaces with *multiple* physical tags?

(Patition numbers are designed to assign tags "element-by-element", 
disregarding any elementary or physical geometrical entities.)


> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh

Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science