DA question

[Amit.Itagi at seagate.com]

Randy,

I guess, since you are doing a frequency domain calculation, you eventually
end up with a single matrix equation.

I am planning to work in the time domain. Will that change things ?

Thanks

Rgds,
Amit



                                                                           
             Randall Mackie                                                
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Hi Amit,

Why do you need two staggered grids? I do EM finite difference frequency
domain modeling on a staggered grid using just one DA. Works perfectly
fine.
There are some grid points that are not used, but you just set them to zero
and put a 1 on the diagonal of the coefficient matrix.


Randy


Amit.Itagi at seagate.com wrote:
> Hi Berend,
>
> A detailed explanation of the finite difference scheme is given here :
>
> http://en.wikipedia.org/wiki/Finite-difference_time-domain_method
>
>
> Thanks
>
> Rgds,
> Amit
>
>
>
>

>              Berend van Wachem

>              <berend at chalmers.

>              se>
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Subject
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>

>

>              04/09/2008 02:59

>              PM

>

>

>              Please respond to

>              petsc-users at mcs.a

>                   nl.gov

>

>

>
>
>
>
> Dear Amit,
>
> Could you explain how the two grids are attached?
> I am using multiple DA's for multiple structured grids glued together.
> I've done the gluing with setting up various IS objects. From the
> multiple DA's, one global variable vector is formed. Is that what you
> are looking for?
>
> Best regards,
>
> Berend.
>
>
> Amit.Itagi at seagate.com wrote:
>> Hi,
>>
>> Is it possible to use DA to perform finite differences on two staggered
>> regular grids (as in the electromagnetic finite difference time domain
>> method) ? Surrounding nodes from one grid are used to update the value
in
>> the dual grid. In addition, local manipulations need to be done on the
>> nodal values.
>>
>> Thanks
>>
>> Rgds,
>> Amit
>>
>
>
>