[Gmsh] 2D unstructured mesh problem

Umberto Paoletti paoletti at circuit.kuee.kyoto-u.ac.jp
Tue Nov 11 02:49:49 CET 2008


Thanks.

I understand, the "line" instruction defines only a segment between two 
points.
After not using the program for a while, I did not remember this 
fundamental "detail", which is also clearly stated in the manual.
It's my fault.

However, I would like to make one comment.
My mistake has been supported by the fact the program seems to accept 
the instruction also with a list of more than two points.
The geometry also is built correctly, and the problem comes out only at 
some corners during meshing.

Thank you again
Umberto



David Colignon wrote:
> Hi,
>
> your Line and Line Loop definitions are wrong.
>
> You should have a look at the tutorial t1.geo
>
> Cheers,
>
> Dave
>
> -- 
> David Colignon, Ph.D.
> Collaborateur Logistique F.R.S.-FNRS
> CÉCI - Consortium des Équipements de Calcul Intensif
> ACE - Applied & Computational Electromagnetics
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> Université de Liège
> 4000 Liège - BELGIQUE
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>
>
> Umberto Paoletti wrote:
>> Hello,
>>
>> I found a problem in this very simple example.
>> Some corners of the internal hole seem to be skipped by the mesh 
>> algorithm.
>> Why?
>>
>> Thanks
>> Umberto
>>
>>
>> unit =  0.001000;
>>
>> lc = 0.1*unit;
>>
>> edge = 2*unit;
>> holedge = 0.5*unit;
>>
>> z = 0*unit;
>>
>> //external edge
>> x1 = 0*unit;
>> y1 = 0*unit;
>> x2 = x1+edge;
>> y2 = y1;
>> x3 = x2;
>> y3 = y2+edge;
>> x4 = x3-edge;
>> y4 = y3;
>> Point(1) = {x1,y1,z, 1*lc};
>> Point(2) = {x2,y2,z, 1*lc};
>> Point(3) = {x3,y3,z, 1*lc};
>> Point(4) = {x4,y4,z, 1*lc};
>> Line(1) = {1:4,1};
>> Line Loop(2) = {1};
>>
>> x5 = 1*unit;
>> y5 = 1*unit;
>> x6 = x5+holedge;
>> y6 = y5;
>> x7 = x6;
>> y7 = y6+holedge;
>> x8 = x7-holedge;
>> y8 = y7;
>>
>> //hole edge
>> Point(5) = {x5,y5,z, 1*lc};
>> Point(6) = {x6,y6,z, 1*lc};
>> Point(7) = {x7,y7,z, 1*lc};
>> Point(8) = {x8,y8,z, 1*lc};
>> Line(3) = {5:8,5};
>> Line Loop(4) = {3};
>>
>>
>> Plane Surface(1) = {2,4};
>>
>>
>>
>
>

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