[Getdp] Basic questions from a beginner

Egmont Schreiter eschreiter at hs-zigr.de
Wed Aug 29 09:06:14 CEST 2007


Hello again,
yesterday I read at http://www.geuz.org/pipermail/getdp/2006/000826.html 
and http://www.geuz.org/pipermail/getdp/2006/000837.html . With this 
knowledge I assume that each galerkin formulation in the form "galerkin 
{[epression_1, epression_1] ...}" stands for "integral over the inner 
product of expression_1 and expression_2 in a defined region.

 From this point of view the second {d v} is not a repetition but a 
second part of the equation.

And is it right to say Dof{} returns not only "this is the unknown", but 
returns also a vector("getdp.pdf" Page 62)? How is the dimension of this 
vector specified?

So I wonder if  {d v} = {grad v} is always correct or if this depends on 
the form (Form0, Form1,... etc manual getdp.pdf page 40)  of  v?

Can anyone comment this thinkings?

Best regards
E. Schreiter
(I thought it would be ok, to write my own findings, because i assume, 
there will be enough question in futer from me)

Egmont Schreiter schrieb:
> Hello,
>  i am just beginning to learn and work with getdp (with gmsh). After 
> trying some of the examples from the wiki, now i try to understand the 
> formulation. Later I have to solve a problem in 3D with coupled 
> inductors and ferrite.
>
> Now I stop at the electrostatic example mStrip.geo & mStrip.pro. There 
> is the formulation:
> Equation {Galerkin { [ epsr[] * Dof{d v} , {d v} ]; In DomainCC_Ele; 
> Jacobian Vol; Integration GradGrad; }}
>
> My questions:
> 1. Can Dof{d v} also be written as Dof{Grad v}? - Where is this 
> documented? (I searched the mail-list for it)
> 2. Means Dof{x} that x is the unknown?
> 3. In this case (2.), why is {d v} repeated after  "Dof{d v},"?
>
> So far for my first posting. I would be glad about your answers.
> Best regards
> Egmont Schreiter
>   


-- 
Dipl. Ing. (FH) Egmont Schreiter
Telefon +49(0)3583 61 1382
Email: ESchreiter at hs-zigr.de