[Dune] a problem with refinement

Fallahi Arya Arya.Fallahi at psi.ch
Thu Jun 23 21:05:01 CEST 2011

Dear Robert,

Thank you for your email. I think the volume error would rather be modified. In the assertion step the volume error is assumed to be an absolute error (computed_volume-volume). However, I believe a relative error better makes sense for example (computed_volume - volume)/volume. I suggest to change this in dune, in this case such problems will be avoided.


-----Original Message-----
From: Robert Kloefkorn [mailto:robertk at mathematik.uni-freiburg.de]
Sent: Thu 6/23/2011 8:12 PM
To: dune at dune-project.org; Fallahi Arya
Subject: Re: [Dune] a problem with refinement
Dear Arya,

the problem was introduced by the slight pertubations in the vertex 
coordinates your macro grid has, for example,

4.997688e+02  instead of  5.000000e+02 (use this one).

Enclosed you'll find the corrected version. Nevertheless, if you want to 
keep your old file you should either compile ALUGrid with the 
preprocessor flag -DNDEBUG which I recommend for production runs. You 
could also remove the assertion or increase the upper bound for the 
volume error in that assertion to 1e-8 or something like this.




   Dr. Robert Klöfkorn         <robertk at mathematik.uni-freiburg.de>

   Mathematisches Institut              Tel: +49 (0) 761 203 5630
   Abt. für Angewandte Mathematik       Fax: +49 (0) 761 203 5632
   Universität Freiburg
   Hermann-Herder-Str. 10
   79104 Freiburg


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