Re: [Getfem-users] High level generic assembly procedures

[Yves Renard]

Dear Marco,

All seems to me correct in your implementation. This is probably just
the test line 2074 of getfem_generic_assembly.cc
which is not correct for one-dimensionnal problems.

I think the test should be

 GA_DEBUG_ASSERT((qdim == 1 && t.sizes()[0] == N) ||
                      (t.sizes()[1] == N && t.sizes()[0] == qdim) ||
                      (N == 1 && t.sizes()[0] == qdim),
                      "dimensions mismatch");

May be you can try this. I will validate it if it works.

Regards,

Yves.


 
Le 01/04/2014 16:56, Marco Pischedda a écrit :
> Dear Yves,
>
> thank you for your fast answer.
>
> I have another question:
>
> - I have a monodimensional problem but the unknowns are vectorial. I
> set the vectorial
> dimension of the unknows with mf_u.set_qdim(3) and with mf_p.set_qdim(3).
> When I define the expression " Grad_u.Test_p "  i receive the following error:
>
> terminate called after throwing an instance of 'gmm::gmm_error'
>   what():  Error in
> ../../getfem-svn/getfem/src/getfem_generic_assembly.cc, line 2074 :
> dimensions mismatch
>
> Grad_u should be a 2nd order tensor, while Test_p should be a vector.
> I suppose the
> problem is that Grad_u is interpreted as a vector while Test_p is
> interpreted as a scalar.
> How can I use the high level generic assembly procedures on vectorial problems
> defined on a monodimensional computational domain?
>
> Thanks in advance
>
> Marco
>
>
>
>
>
> 2014-04-01 8:42 GMT+02:00 Yves Renard <address@hidden>:
>> Dear Marco,
>>
>> Yes, your code is correct and it should work correctly.
>> Note that you can also use the high level generic assembly with the
>> model object using a generic assembly brick.
>> Note also that high level assembly is only available in the svn
>> repository version of Getfem
>> (and a very recent version, at least r4570 because a bug have been
>> corrected on coupled problems recently).
>>
>> Yves.
>>
>>
>> Le 31/03/2014 14:00, Marco Pischedda a écrit :
>>> Dear all,
>>>
>>> I want to use the high level generic assembly procedures in order to
>>> use the automatic differentation for calculating the Jacobian of a
>>> non-linear problem.
>>>
>>> For example I want to calculate the Jacobian of two vectorial
>>> equations in the unknowns "u" and "p". The first vectorial equation is
>>> (u+p).Test_u while the second is (u+p).Test_p.
>>>
>>>  It is correct the following code?
>>>
>>>  gmm::sub_interval Iu(0, ndofs_u);
>>>  gmm::sub_interval Ip(ndofs_u,ndofs_p);
>>>  workspace.add_fem_variable("u", mf_u, Iu, U);
>>>  workspace.add_fem_variable("p", mf_p, Ip, P);
>>>  workspace.add_expression("(u+p).Test_u + (u+p).Test_p",mim);
>>>  getfem::model_real_sparse_matrix Jac(ndofs_u+ndofs_p, ndofs_u+ndofs_p);
>>>  workspace.set_assembled_matrix(Jac);
>>>  workspace.assembly(2);
>>>
>>> In the matrix Jac I have the Jacobian of the system?
>>>
>>>
>>> Thanks in advance
>>>
>>> Marco
>>>
>>> _______________________________________________
>>> Getfem-users mailing list
>>> address@hidden
>>> https://mail.gna.org/listinfo/getfem-users
>>
>> --
>>
>>   Yves Renard (address@hidden)       tel : (33) 04.72.43.87.08
>>   Pole de Mathematiques, INSA-Lyon             fax : (33) 04.72.43.85.29
>>   20, rue Albert Einstein
>>   69621 Villeurbanne Cedex, FRANCE
>>   http://math.univ-lyon1.fr/~renard
>>
>> ---------
>>


-- 

  Yves Renard (address@hidden)       tel : (33) 04.72.43.87.08
  Pole de Mathematiques, INSA-Lyon             fax : (33) 04.72.43.85.29
  20, rue Albert Einstein
  69621 Villeurbanne Cedex, FRANCE
  http://math.univ-lyon1.fr/~renard

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