> How are you applying boundary conditions? That requires the > sparsity pattern?
I am trying to apply Dirchlet boundary conditions, ie. solution = 0 on all boundaries. This, as I understand it, requires a Guass elimination process to keep the final matrix symmetric. If it really is necessary to have the sparsity pattern to do this, and it cost more memory, so be it... I am confused on why this needs the sparsity pattern; if I am to be honest. I will speak with the dealii developers on what the *real* problem is. Perhaps in a few days I can be more specific. Sorry if I seem so vague at this time. :-) Very happy you are willing to help. Best, Toby ----- Toby D. Young (Adiunkt) Department of Computational Science Institute of Fundamental Technological Research Polish Academy of Science Room 206, ul. Swietokrzyska 21 00-049 Warszawa, POLAND