SubsamplingVTKWriter seems broken
I have been using a regular VTKWriter to print the solutions of my PDE solver. When I discovered some artifacts in the VTK output (see the issue on PDELab), I set up a SubsamplingVTKWriter to further investigate. However, now I find new artifacts that are not related to grid refinement.
For our module, we set up a testing suite in which we compare the results (VTK files) of our PDE solver for a pseudo 1D case with the solution provided by an ODE solver. Regarding the residuals for both the solution (
head) and its weighted gradient (
flux), some structured wave-like patterns emerge for subsampling levels >0.
This is the VTU file for subsampling level 2: ode_higherorder_0008-00029.vtu
Could this somehow be related to the issue I'm having with the visualization after local grid refinement?