Le 09/02/2010 22:44, Cédric Venet a écrit :
>
> Le 09/02/2010 17:37, Yves Renard a écrit :
>> On lundi 8 février 2010, Cédric Venet wrote:
>>> Hi,
>>>
>>> I am trying to assemble the term "v.Grad u" where v is a field of vector
>>> data on my mesh. u is a scalar field, and the unknow of my equation. I
>>> am trying to do this:
>> It is possible to have vector data, but you declaration seems to be
>> wrong. It
>> should be something like that :
>>
>> assem.set("F=data(1); G=data$2(qdim(#1), #1); M$1
>> (#1,#1)+=comp(Base(#1).Grad(#1).Base(#1))(i,:,k,:).G(k,i).F(p)");
>> assem.assembly();
>>
>> Yves.
>
> Hi,
>
> While this solve the parse problem, the answer is more complex and still
> elude me.
> My fem_mesh #1 has a qdim of 1, so with this solution, I hit the assert
> invalid size for data argument. (my data vector is 3 times the number of
> dof in #1). So my understanding is that I need a new fem_mesh #2, with a
> qdim of 3. However, I didn't find a way to do this without duplicating a
> lot of work (ie, without respecifying all the finite element on each
> convex). Is there a way to avoid this?
>
> regards,
> Cédric
>
ok, it seems to work (at least it does not assert) if I create a fake
fem mesh mf2 using the same linked mesh as #1 but without seting fem
element on it. But I am not sure this is valid, or if it does what I want.
getfem::generic_assembly assem;
assem.push_mi(fm.GetIntegrationMesh());
assem.push_mf(fm.GetShapeMesh());
getfem::mesh_fem mf2(fm.GetShapeMesh().linked_mesh(),3);
assem.push_mf(mf2);
std::vector<T> tmpve(1,m_coef);
assem.push_data(tmpve);
assem.push_data(m_speed);
assem.push_mat(fm.GetAMatrix());
// warning: non symetric!!
// row/column major... check the order of data$2
assem.set("F=data(1);G=data$2(qdim(#2),#1);
M$1(#1,#1)+=comp(Base(#1).Grad(#1).Base(#1))(i,:,k,:).G(k,i).F(p)");
assem.assembly();
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