[petsc-users] Extra Variable in DMCircuit

[Florian Meier]

Seen from that perspective it is reasonable to add a further vertex,
thank you!
I have implemented that and it works very good.

Regarding the scalability: My previous approach was to do binary search
and running the calculation multiple times with a different constant
parameter, so this is much faster anyway :-)

Greetings,
Florian

On 03/14/2014 11:44 AM, Matthew Knepley wrote:
> On Fri, Mar 14, 2014 at 4:13 AM, Florian Meier <florian.meier at koalo.de
> <mailto:florian.meier at koalo.de>> wrote:
> 
>     Hi,
>     I got quite far with my project, although I still have not managed (or
>     better "have not tried...") to get the parallelization running (Shri:
>     Any news about that?).
> 
>     Now I would like to add a single global variable (and a single equation)
>     to the equation system. Is there an elegant way to do this with
>     DMCircuit?
> 
>     A hackish solution might be to add an additional imaginary vertex that
>     is excluded from all other calculations, but that does not seem to be
>     the right way to do it.
> 
> 
> The graph expresses the influence of variables on each other, so if you have
> a globally coupled variable, then a node linked to all other nodes is the
> appropriate structure.
> 
>  The problem is that this is not scalable since it will result in a
> dense row. I
> would do this for now. And when your problem is large enough for this to
> be a drag on scalability (thousands of processes), switch to specialized
> code.
> 
>    Matt
>  
> 
>     Greetings,
>     Florian
> 
> 
> 
> 
> -- 
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which
> their experiments lead.
> -- Norbert Wiener