Dear Erik,

Thank you for your respond. I want to use cylindrical coordinates in my problem (r, phi, z) and I think I need a physical boundary condition for phi ,rather than a symmetry. It seems rotational boundary condition can be helpful and I thought if I use periodic boundary condition for phi (namely , periodic_y = yes) the code should satisfy my demand . However, it could not.

Am I on the right track ?
I think RotatingSymmetry90 cannot do that , because I want to have the full range [-PI, PI] and evolve it . All I need is connecting two ends of the grid in phi direction (or y) together . In other words, I like to tape -PI to PI.

Do you think the thorn Periodic is the appropriate thorn or there is a better thorn which can do that for me ?

Thank you
Hassan


On Mon, Feb 28, 2011 at 5:37 PM, Erik Schnetter <schnetter@cct.lsu.edu> wrote:
Hassan

The current version of this thorn is located in an svn repository at
<http://svn.cactuscode.org/arrangements/CactusNumerical/Periodic>.
However, this thorn implements a toroidal symmetry, not a rotational
symmetry. Can you describe the symmetry that you are trying to apply?
For example, there is another thorn CactusNumerical/RotatingSymmetry90
that may be more suitable. There is also another thorn available that
implements a Cartoon symmetry.

We describe much of our code at <http://einsteintoolkit.org>, and we
use the mailing list <users@einsteintoolkit.org> for discussion. Would
you mind using this mailing list instead of keeping this conversation
private? The mailing list has the advantage that others will also be
able to help when I don't know the answer.

-erik

On Mon, Feb 28, 2011 at 6:20 PM,  <halatae1@illinois.edu> wrote:
> Dear Dr. Schnetter,
>
> I am Hassan Halataei, working in Professor Shapiro's Numerical Relativity group in Univ. of Illinois at Urbana-Champaign. I am trying to use the thorn Periodic you have written in 2003 to implement rotational symmetry in my problem (Single Black hole surrounded by an accretion disk) . I read the 2-page documentary of the thorn and acted according to that . However, the  thorn does not work for me . I tried several different things for days to make it work , however the result does not obey periodic boundary condition . I was wondering if you let me know if there is anything that I missed or any other consideration that I must take care of ?
>
>
> Thank you
> Hassan
>



--
Erik Schnetter <schnetter@cct.lsu.edu>   http://www.cct.lsu.edu/~eschnett/