[Carpet] regridding?

[Bela Szilagyi]

On Friday 05 May 2006 16:35, Ian Hawke wrote:
> On Fri, 2006-05-05 at 16:25 +0200, Bela Szilagyi wrote:
> > Cristian Ott and I have found a feature of Carpet that could be regarded
> > as a bug. Say you are on refinement level 3 out of 3.  You ask for a
> > regrid by setting CarpetRegrid::coordinates, and your new parameter value
> > involves a change of refinement level 2. Carpet will regrid and schedule
> > PostRegrid for refinement level 3 but not for the coarser levels.
>
> Does this happen all the time, or only if you regrid when level 3 and
> level 2 are not in sync? According to my reading of the code it should
> only happen in the latter case.

Your reading is correct -- if regridding is done at a time that is in sync 
with the grid that is being redefined, then postregrid gets scheduled on the 
re-defined level.

>
> I would say that you should be allowed to change the coarser grid (it is
> one way of implementing true AMR) but should only be able to do it when
> the grids are in sync.  I would consider anything else to be an error in
> the regridding algorithm, not necessarilly in Carpet.


Certainly, testing for this criteria (either by carpetregrid::regrid_every or 
within the regrid-requesting thorn) is doable.



>
> Ian
>
> > I would propose one of the following:
> > 1. explicitely forbid requests of refinement level changes of a coarser
> > grid than the current one 2. delay these requests till evolution gets to
> > the appropriate coarser grid 3. schedule postregrid for the coarser
> > levels as well
> > 4. schedule postregrid for all levels at any regrid event.
> > 5. whatever...
> >
> >
> > On Friday 05 May 2006 15:07, Bela Szilagyi wrote:> Should we introduce a
> > parameter that will tell CarpetIOHDF5  that at> recovery it should read
> > the value of CarpetRegrid::coordinates (and> possibly other carpetregrid
> > parameters) from the checkpoint file rather> than from the parameter
> > file?  This would go along the same lines as>>
> > CarpetIOHDF5::use_reflevels_from_checkpoint>> introduced by Christian
> > Ott.>> On Thursday 04 May 2006 17:31, Erik Schnetter wrote:> > On May 4,
> > 2006, at 09:30:17, Bela Szilagyi wrote:> > > Can one (or -- is one
> > supposed to) adjust carpet grid structure by> > > steering> > >
> > dynamically the parameter CarpetRegrid::coordinates  ?> >> > Yes, this is
> > supposed to work. -- Bela
> > Szilagyi----------------------------------------------------Max-Planck-In
> >stitut für GravitationsphysikAlbert-Einstein-InstitutTel: +49 331 567
> > 7632Fax: +49 331 567
> > 7649----------------------------------------------------
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> >evelopers

-- 
Bela Szilagyi
----------------------------------------------------
Max-Planck-Institut für Gravitationsphysik
Albert-Einstein-Institut
Tel: +49 331 567 7632
Fax: +49 331 567 7649
----------------------------------------------------