Hi, I'm trying to figure out a clean way to find the nnz sparsity structure for a given variable. That is given an EquationSystem and its corresponding Dofmap, can I find the correct nnz structure to create a matrix ignoring the coupling between variables. It is useful for creating block preconditioners where the entire matrix (with all coupling between variables) is not needed but just individual blocks would be enough to perform Block-Jacobi type operations for the preconditioner.
I can always sweep through all the elements, compute the dofs for the variable of interest and create this nnz but that seems hackish. This information should definitely be derived from DofMap but looking at the DofMap code, I could not figure out how this can be done correctly either. Is there a simpler and efficient way to do this ? Vijay ------------------------------------------------------------------------------ Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
