[Getdp] Dual Formulation in the wiki

[Amit.Itagi at seagate.com]

David Colignon <David.Colignon at ulg.ac.be> wrote on 01/31/2007 08:11:21 AM:

> Hi,
>
> from  http://geuz.org/pipermail/getdp/2006/000869.html  in the mailing
list:
>
> ...
> the condition on the coefficients associated to the second order
> basis functions must be homegeneous ( 0 value ) otherwise the
> imposed condition considers a boundary condition other than constant
> ( with second degree variation ). This is due to the fact that the
> second order elements are built with hierarchical basis functions.
> ...

For a problem with Dirichlet BC on a part of the boundary, and mixed BC on
the rest of the boundary, how would I use second order elements ? Do the
elements on the boundary have to be set to first order in that case ? How
do I set elements selectively to second order ( I know that it can be done
with Adapt P1 ... but then I cannot select the elements) ?

Sorry for posing so many questions. I really like getdp, and I am trying my
best to understand the workings through the documentation, examples,
theoretical references, and the mailing list.

Rgds,
Amit

>
> Cheers,
>
> Dave
>
> --
> David Colignon, Ph.D.
> ELAP - Service d'Electricité Appliquée
> Institut Montefiore B28
> Université de Liège
> 4000 Liège - BELGIQUE
> Tél: +32 (0)4 366 37 32
> Fax: +32 (0)4 366 29 10
> http://elap.montefiore.ulg.ac.be
>
>
> Amit.Itagi at seagate.com wrote:
> > Hi,
> >
> > I have a question regarding the dual formulation example (
> > http://www.geuz.org/getdp/wiki/DualFormulations ). I find that the
first
> > order and the higher order elements satisfy different constraints (See
> > excerpt below). Could someone kindly explain the motivation for
defining
> > separate constraints ?
> >
> > The higher order elements are being used as a result of P1 adaptation.
I
> > would think that since the same problem is being solved, the
constraints
> > would remain the same.
> >
> > Thanks
> >
> > Rgds,
> > Amit
> >
> >
> >
>
//----------------------------------------------------------------------------------------------------------------------------

> > FunctionSpace {
> >   { Name Hgrad_phi_MagSta; Type Form0;
> >     BasisFunction {
> >       { Name sn1n ; NameOfCoef wn1n ; Function BF_Node ; Support
Tot_Mag;
> > Entity NodesOf[All]; }
> >       { Name sn2e ; NameOfCoef wn2e ; Function BF_Node_2E ; Support
Tot_Mag
> > ; Entity EdgesOf[ All ] ; }
> >       .
> >        .
> >        .
> >     }
> >     Constraint {
> >       { NameOfCoef wn1n; EntityType NodesOf ; NameOfConstraint Sta_phi;
}
> >       { NameOfCoef wn2e ; EntityType EdgesOf ; NameOfConstraint
> > Sta_phi_Zero ; }
> >       .
> >       .
> >       .
> >     }
> >   }
> >
> > Constraint {
> >   { Name Sta_phi ;
> >     Case {
> >       { Region left ; Value -100. ; }
> >       { Region right ; Value 100. ; }
> >     }
> >   }
> >   { Name Sta_phi_Zero ;
> >     Case {
> >       { Region left ; Value 0. ; }
> >       { Region right ; Value 0. ; }
> >     }
> >   }
> >
>
//---------------------------------------------------------------------------------

> >
> >
> >
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