Hi Ben, Maybe check out the SolutionTransfer class. If you have a more coarser and a more fine mesh that share a common refinement history (i.e. the fine one is refined in deal.ii from the coarse one), then you can use this class to transfer the vector of values at the dofs of the coarse solution (the solution) to the vector of values at the dofs of the refined solution. You can then create a norm you like using the various norms defined in the Vector class, or from scratch.
I have done this in the past and it seemed to work okay. As to whether there are any problems with your current approach, I suppose the main question is whether you have interpreted your solution correctly in the function you derive. Hope this helps. Cheers, Michael On 6/16/11, Ben Crestel <[email protected]> wrote: > Hi, > > I was wondering what to do to run a convergence analysis when you don't > know the exact solution to your problem. > 'VectorTools::integrate_difference' requires a class Function<dim> for > the exact solution. > > So what I did, so far, is to define a nested class derived from > Function<dim>, in the class for my problem, with method 'value' > returning the solution of the current problem. I export that function > for my finest grid (convergence analysis in space) that I consider as my > exact solution, then when I run on coarser grids, I use that function in > 'VectorTools::integrate_difference' as my exact solution. > > Results are a bit weird, so far. Do you see something wrong in > principle? Any idea of what I should be doing instead? > > Best, > > Ben > > > > _______________________________________________ > dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii > _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
