> I'm attempting to create a program to implement a time-dependant problem > using a DG method and in calculating the exact error I need to calculate > the H^1 semi-norm on each cell. I was wondering whether > integrate_difference using the H^1 semi-norm can do this for DG - the > reason I ask is because while the rest of my error goes to zero as I > refine the mesh-size and the time-step, this portion of the error goes to > infinity if I use integrate_difference, which is clearly not correct.
I believe the function should work -- it just does integration of the gradient on a particular cell, without regard for the element in use. Of course what you get is the broken H1 seminorm for each cell since your finite element solution is not in H1 when you use discontinuous elements. In other words, if your error goes to infinity, there must be a problem somewhere in computing the solution. W. ------------------------------------------------------------------------- Wolfgang Bangerth email: [email protected] www: http://www.math.tamu.edu/~bangerth/ _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
