[Carpet] [Cluster-users] job aborts with wierd error msg when Carpet does 1st recompose

[Jonathan Thornburg]

Hi, Erik,

On Wed, 27 Sep 2006, Erik Schnetter wrote:
> This error is caused by
> 
> Carpet::prolongation_order_space = 4
> 
> You are selecting 4th order prolongation operators.  These do not exist.  You
> need to choose either 3rd order or 5th order operators.

Ok.

For a system of PDEs (BSSN) which is 1st order in time and 2nd order
in space, do I understand correctly that I need 3rd order prolongation
to get overall 2nd order accuracy (assuming 2nd order FD in physics thorns),
and 5th order to get overall 4th order accuracy (assuming 4th order FD in
physics thorns)?



> The error message should be improved.

Indeed... :)

ciao,

-- 
-- Jonathan Thornburg <jthorn at aei.mpg.de>      
   Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut),
   Golm, Germany, "Old Europe"     http://www.aei.mpg.de/~jthorn/home.html      
   "Washing one's hands of the conflict between the powerful and the
    powerless means to side with the powerful, not to be neutral."
                                      -- quote by Freire / poster by Oxfam