On 05/09/2013 04:21 PM, Peter Zajac wrote:
>
> On Thu, May 9, 2013 at 11:29 AM, David Knezevic 
> <[email protected] <mailto:[email protected]>> wrote:
>
>     On 05/09/2013 02:22 PM, PETER ZAJAC wrote:
>
>         David,
>
>           I was worried about the volume element for integration. If I
>         use explicit transformations of coordinates to spherical how
>         would I make sure that the volume element for integration
>         changes accordingly.
>
>
>     Cartesian -> spherical is just a change of coordinates, so if you
>     take that into account properly in the weak form then everything
>     is fine. In particular, you need to account for:
>     - the change of measure, which gives an extra r^2 * \sin(\phi)
>     factor, if memory serves
>     - the change of variables in the gradient terms
>
>     It would be nice to automate this so that it is automatically
>     included in libMesh's JxW and dphi, which is what Paul was
>     referring to. But the easiest thing for you in the short term
>     would be to just explicitly deal with the change of variables
>     yourself.
>
>
> Great. Thank you. This will work.

P.S. You'll also need to impose periodic boundary conditions in the 
azimuthal direction.



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