[Gmsh] file format

[Christophe Geuzaine]

On 13/03/10 19:45, Rui Maciel wrote:
>
> oka wrote:
>> Dear Rui Maciel,
>>
>> Thank you so much for quick response.
>> 4 5 0 1 2 1 -4
>> about 1 2 1 -4, manual has no explanation.
>> I guess
>> 2 means this mesh in overlap region
>> 1 means partition number
>> -4 means overlap facing opposite mesh number (4)
>> Is this true ?
>
>
> Considering that the<element tags>  field taken from the example element entry
> consists of the following set of tokens:
>
> 5 0 1 2 1 -4
>
>
> According to the MSH ASCII file format reference, those tokens should be
> interpreted as:
>
> 5 =>  number of tags present in this element's tag field
>
> 0 =>  physical entity reference
>
> 1 =>  geometrical entity reference
>
> 2 =>  mesh partition reference
>
> 1 =>  undocumented
>
> -4 =>  undocumented and, according to the manual, invalid.
>
>
> To be sure it would probably be better to dig through Gmsh's MSH export
> routine.  I've took a crack at it but unfortunately I was unable to find the
> exact code which exports that part of the document.  Still, in alterantive you
> could simply ignore those offending tags, as the remaining info is still valid
> and it's still possible to resume parsing without any major consequences.

Hi - indeed, the "-4" is not documented yet (it only appears in nightly 
builds and in svn). We are testing ghost cells generation, which will be 
a new feature in Gmsh 2.5. (Gmsh 2.5 will bump the .msh file version to 
2.2, with better support for partitioned meshes.)


>
>
> Hope this helps,
> Rui Maciel
>
> _______________________________________________
> 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
http://www.montefiore.ulg.ac.be/~geuzaine