[CIG-SEISMO] Model error in mesh

[Dimitri Komatitsch]

Dear Ed, dear all,

If your Jacobians are all negative, your mesh is likely good, it is just 
that you export the points in reverse order (clockwise instead of 
counterclockwise).

What is not good is positive and negative in the same mesh; all positive 
or all negative is OK. (in the latter case, you need to flip them once 
and for all before importing the mesh in SPECFEM)

Best wishes,
Dimitri.

On 08/17/2018 11:18 PM, cristini paul wrote:
> Dear Ed,
> 
> Please could you provide more information on the type of error you are 
> getting.
> 
> If it is connected to the quality of the mesh (too distorted) then 
> depending on the geometry, it is sometimes difficult to get a good mesh 
> with Gmsh without dividing the geometry into several elementary parts.
> 
> Let me also remind you that you need to define your line loops in a 
> counter clockwise manner as it is done in the Gmsh example provided with 
> Sepcfem2D otherwise you will get negative jacobians.
> 
> Thank you
> 
> Best regards
> 
> Paul
> 
> 
> 
> Le 17/07/2018 à 00:20, ed cas a écrit :
>> Dear developers and users,
>>
>>
>> I have been trying to produce a readable mesh file
>> for specfem2d by using gmsh.
>>
>> I produced the mesh inside gmsh, I saved the mesh and then paste it to 
>> the MESH directory
>>
>> and then run the command
>>
>> python LibGmsh2Specfem_convert_Gmsh_to_Specfem2D_official.py 
>> model_shallow_v42 -t A -b A -r A -l A
>> That produced the five files in the same directory.
>>
>> Please find attached the file I have been trying to run 
>> (model_shallow_v42).
>>
>> However, when running specfem2d gives error telling me about Jacobians,
>> I have been trying for a couple of days and cannot get with the error, 
>> I checked the
>> line loops and seems  fine , I have resized the elements and with no 
>> success.
>>
>> I was hoping you could help me with this.
>> Could you please check my file and indicate me what is wrong with it,
>> and any solution.
>>
>> I would really appreciate your help,
>>
>> Thank you for your time and help,
>>
>> Sincerely,
>>
>> -------------------------------------------
>> Edwin Castillo
>>
>>
>>
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> 
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-- 
Dimitri Komatitsch, CNRS Research Director (DR CNRS)
Laboratory of Mechanics and Acoustics, Marseille, France
http://komatitsch.free.fr