# [Getdp] material property defined in each element

Ruth V. Sabariego r.sabariego at ulg.ac.be
Tue Apr 5 16:12:33 CEST 2011

```You could fill a function space with the values of sigma by means of a
constraint.
You start reading the values from a text file "mysigma.txt" with the
following structure:
TotalNumberOfNodes
numberOfNode SigmaValue
.                         .
.                         .
numberOfNode SigmaValue

// get (nodal values of) sigma from .txt file:
listsigma = ListFromFile["mysigma.txt"];
mysigma[] = ValueFromIndex[]{listsigma{}};

============================================
Constraint {
// completely fix sigma function space
{ Name MySigma ; Type Assign ;
Case {
{ Region MyDomain  ; Value mysigma[] ; }
}
}

============================================
FunctionSpace {
{ Name BF_sigma ; Type Form0 ;
BasisFunction {
// interpolate each component of sigma using standard nodal
// shape functions; you could also define other fuction space
{ Name sn ; NameOfCoef s ; Function BF_Node ;
Support Region[{MyDomain}] ; Entity NodesOf[ All] ; }
}
SubSpace {
// make subspaces available in formulation
{ Name sub ; NameOfBasisFunction sn; }
}
Constraint {
{ NameOfCoef s ;
EntityType NodesOf ; NameOfConstraint MySigma; }
}
}
}
============================================
And then you can use it in a formulation as:

Formulation {
{ Name Electrostatics_vf ; Type FemEquation ;
Quantity {
{ Name v ; Type Local  ; NameOfSpace Hgrad_vf_Ele ; }
// get each sigma tensor component
{ Name sig ; Type Local  ; NameOfSpace BF_sigma[sub] ; }

}
Equation {

Galerkin { [ {sig} * Dof{Grad v} , {Grad v} ] ;

// hack: null terms necessary to force initialization of fully
// fixed function space
Galerkin { [ Dof{sig} * 0 , {v} ] ;
}
}
}

Regards,
Ruth

On 05/04/11 14:44, Jens Trommler wrote:
> Hi,
>
> I have the conductivity of each element given from another simulation
> and now want to use this conductivity in GetDP for some
> quasistationary simulations.
> Is there an easy way to set the conductivity element-wise?
> I guess that I need to write an .res file but don't really know how
> exactly it should look like and how I can use it in a GetDP script.
> Looked already in the examples but couldn't find any similar problem.
>
> Thank you for any help.
> Regards,
> Jens.
>
> _______________________________________________
> getdp mailing list
> getdp at geuz.org
> http://www.geuz.org/mailman/listinfo/getdp
>

--
Dr. Ir. Ruth V. Sabariego
University of Liege, Dept. of Electrical Engineering&  Computer Science,
Applied&  Computational Electromagnetics (ACE),
phone: +32-4-3663737 - fax: +32-4-3662910 - http://ace.montefiore.ulg.ac.be/

```