[dune-pdelab] bug/problem in set_trivial_row function routine(dune-pdelab)

[Felix Heimann]

Dear Nagaiah,

I am not sure, what exactly you mean by "more than one solution
component". If you refer to e.g. a vector valued solution, then this
should be represented by e.g. a PowerGridFunctionSpace. In such a case,
the set_trivial_row() function will work correctly as long as the
indices in the constraints container are consistent to the indices of
the grid function space (this should be guaranteed if you set up the
container with the Dune::PDELab::constraints(..) function). 

However, this functionality is the same for all trivially constrained
dofs, independent of whether they result from a ghost cell in a domain
decomposed non-overlapping application or a Dirichlet boundary in a
standard application. Hence, I do not see the connection to the specific
grid i.e. application and may not have grasped your problem. May be you
can clarify...

Best Regards,
Felix Heimann



Am Mittwoch, den 12.01.2011, 22:57 +0100 schrieb Nagaiah Chamakuri:
> Dear dune-pdelab,
> 
> I have a question about "set_trivial_row" function in
> new_gridoperatorspace.hh at line 885  (precisely I am using Jacobian
> function routine to construct matrices) and defined in
> gridoperatorspaceutilities.hh at line 971. 
> Mainly I am using non overlapping grid (UG grid) and diagonal elements
> of the ghost nodes are set to zero in the global matrix
> in case of more than one solution component presents.
> This function routine works well in case of one solution component
> presents in the problem.
> 
> 
> right answer should look like as follows (up to my knowledge):
> 
> for j=1 to no.of.comp
> B::clear_row(i+j,globalcontainer)
> 
> B::access(globalcontainer,i+j,i+j) = 1,
> 
> 
> 
> Is it right? or  didn't I understand correctly?
> 
> Thanks & Regards
> Nagaiah
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-- 
Felix Heimann
Universität Heidelberg
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